| 2020 | Suppressing STAT3 activity protects the endothelial barrier from VEGF-mediated vascular permeability. | bioRxiv | Vascular permeability can be triggered by inflammation or ischemia in the heart, brain, or lung, where it promotes edema, exacerbates disease progression, and impairs tissue recovery. Vascular endothelial growth factor (VEGF) is a potent inducer of vascular permeability, and VEGF plays an integral role in regulating vascular barrier function in physiological conditions and a variety of pathologies, such as cancer, ischemic stroke, cardiovascular disease, retinal conditions, and COVID-19-associated pulmonary edema and sepsis that often leads to acute lung injury, including acute respiratory distress syndrome. However, after initially stimulating permeability, VEGF subsequently mediates angiogenesis to repair damaged tissue following pathological injury. Consequently, understanding the molecular mechanisms of VEGF-induced vascular permeability will facilitate the development of promising therapies that achieve the delicate balance of inhibiting vascular permeability while preserving tissue repair mediated by VEGF signaling. Here, we demonstrate that VEGF signals through signal transducer and activator of transcription 3 (STAT3) to promote vascular permeability. Specifically, we show that STAT3 ablation reduces vascular permeability using endothelial cell-specific STAT3 knockout mice as well as VEGF-inducible zebrafish crossed with CRISPR-Cas9 generated genomic STAT3 knockout zebrafish. Importantly, STAT3 deficiency does not impair vascular development and function in these animals. Wildtype C57BL/6 mice treated with JAK2 inhibitor, AG490, exhibit decreased vascular permeability when measured in vivo by Miles permeability assay, confirming the role of JAK2 in VEGF-induced vascular permeability. Using human endothelial cells, we describe a novel mechanism of STAT3-dependent transcriptional regulation of intercellular adhesion molecule 1 (ICAM-1), an endothelial transmembrane protein involved in the regulation of vascular permeability. FDA-approved anti-microbial drug, pyrimethamine (PYR), has been identified as an inhibitor of STAT3 function at concentrations known to be safely achieved in humans. We report that PYR substantially reduces VEGF-induced vascular permeability in mice. We confirm that pharmacologically targeting STAT3 increases vascular barrier integrity in human endothelium using two additional STAT3 inhibitor compounds, including atovaquone, an FDA-approved anti-parasitic drug shown to inhibit STAT3-dependent transcription. Taken together, our findings suggest that the VEGF, VEGFR-2, JAK2, and STAT3 signaling cascade regulates vascular barrier integrity and compounds known to inhibit STAT3-dependent activity reduce VEGF-induced vascular permeability in vertebrate models. |
| 2020 | Nrf2 and STAT3 Alleviates Ferroptosis-Mediated IIR-ALI by Regulating SLC7A11. | Oxid Med Cell Longev | Acute lung injury (ALI) has gained increased attention in the field of critical illness research and is associated with a fatality rate of approximately 50%. Nuclear factor erythroid 2-related factor2 () is a key regulator of intracellular oxidation homeostasis and also functions as an antioxidant. It has been reported that Nrf2 associated antioxidant stress is closely related to ferroptosis inhibition. Signal transducer and activator of transcription 3 (STAT3) is activated into phosphorylated STAT3 (pSTAT3) in response to tissue damage and serves as a warning signal to enhance the inflammatory response. In this study, an intestinal ischemia/reperfusion-induced acute lung injury (IIR-ALI) model was established in C57BL/6 mice to investigate the role of Nrf2 in regulating IIR-ALI-associated ferroptosis. Compared with those in the IIR-ALI group, the injection of Fe (15 mg/kg) or ferrostatin-1 (5 mg/kg) (ferroptosis promoter and inhibitor, respectively) via the tail vein could aggravate or alleviate lung injury and pulmonary edema, respectively. Nrf2 was increased in IIR-ALI and promoted the phosphorylation of STAT3 to amplify downstream signals. An oxygen-glucose deprivation and reoxygenation (OGD-R) model was established in MLE12 cells to imitate the ischemia/reperfusion condition. The cells were transfected with lentiviruses to increase or downregulate the levels of STAT3. We found that Nrf2 and STAT3 played key roles in ferroptosis by regulating SLC7A11, which improved the pathological processes associated with ALI. |
| 2020 | β-Sitosterol-loaded solid lipid nanoparticles ameliorate complete Freund's adjuvant-induced arthritis in rats: involvement of NF-кB and HO-1/Nrf-2 pathway. | Drug Deliv | Rheumatoid arthritis (RA), autoimmune disease that is categorized via chronic inflammation manifestation, obesity, cardiovascular risk and even enhanced the mortality and affect the 0.3 and 1% of population worldwide. The current experimental study was scrutinize the anti-arthritic effect of β-sitosterol loaded solid lipid nanoparticles (SLN) against complete Fruend adjuvant (CFA)-induced arthritis via dual pathway. Double emulsion solvent displacement method was used for the preparation of β-sitosterol solid lipid nanoparticles (SLN). CFA was used to induce arthritis and rats were divided into different groups for 28 days. Biochemical, anti-inflammatory, pro-inflammatory cytokines and inflammatory mediator were estimated, respectively. Receptor activator of nuclear factor kappa-B ligand (RANKL), signal transducer and activator of transcription-3 (STAT3) nuclear factor erythroid 2-related factor 2 (Nrf), Heme Oxygenase-1(HO-1) and Nuclear factor-κB (NF-κB) expression were estimated. β-sitosterol-SLN significantly ( < .001) reduced the paw edema, arthritic index and increased the body weight. β-sitosterol-SLN increased the redox status of synovium {reduce the malonaldehyde (MDA) and increase superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT)} level and reduced the cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2, interleukin-6, interleukin-16, interleukin-17 and increased level of interleukin-10, Transforming growth factor beta (TGF-β). β-sitosterol-SLN significantly ( < .001) reduced the level of cyclooxygenase-2 (COX-2), prostaglandin E (PGE), vascular Endothelial Growth Factor (VEGF) and NF-κB. β-sitosterol-SLN significantly increased the expression of HO-1,Nrf and decreased the expression of NF-κB, RANKL, STAT3. In conclusion, β-sitosterol SLN showed the antiarthritic effect via suppression of NF-kB and activation of HO-1/Nrf-2 pathway. |
| 2020 | Oral Administration of Improves the HDM/DNCB-Induced Atopic Dermatitis in NC/Nga Mice. | Nutrients | The present study investigated the protective effects of () ethanol extract (SHE) against atopic dermatitis (AD), known as an abnormal immune response in house dust mite (HDM)/2,4-dinitrochlorobenzene (DNCB)-stimulated NC/Nga mice. The oral administration of SHE attenuated the AD symptoms, including the skin dermatitis severity, transepidermal water loss (TEWL), and ear edema in HDM/DNCB-stimulated mice. Moreover, the histological analysis revealed that SHE improved epidermal hyperplasia and hyperkeratosis, and reduced the dermal infiltrations of mast cells and eosinophils. Moreover, SHE downregulated the expression levels of cytokines (interleukin (IL)-6, IL-10, and interferon (IFN)-γ) and chemokines (Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES), Eotaxin, and Thymus and activation-regulated chemokine (TARC)) by decreasing the expression levels of atopic initiators (IL-25 and IL-33) in HDM/DNCB-stimulated skin. The oral administration of SHE decreased the spleen size, reducing expression levels of AD-related cytokines (IL-4, IL-5, IL-6, IL-10, IL-13, IFN-γ, and TARC) by regulating the expressions of Tbx21 (T-bet), GATA Binding Protein 3 (GATA-3), and Signal transducer and activator of transcription 3 (STAT3). Moreover, SHE significantly attenuated the serum immunoglobulin (Ig)G and IgG levels in HDM/DNCB-stimulated mice. Collectively, these results suggest that could be an ingredient of functional food against abnormal immune response. |
| 2020 | Association between NDRG2/IL-6/STAT3 signaling pathway and diabetic retinopathy in rats. | Eur Rev Med Pharmacol Sci | The aim of this study was to observe the association between N-myc downstream regulated gene 2 (NDRG2)/interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway and diabetic retinopathy (DR) in rats.The model of diabetes was successfully established in Sprague-Dawley rats. All rats were divided into diabetes model group (model group, n=10), pathway inhibitor group (CLT-005 group, n=10), and normal control group (control group, n=10). After successful modeling, blood and retinal tissues of rats were collected. The levels of blood glucose and serum IL-6 were detected. Meanwhile, oxidative and antioxidant indexes reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) were detected via enzyme-linked immunosorbent assay (ELISA). Morphological changes in retinal tissues were observed using hematoxylin-eosin (HE) staining, and the number of corneal nerve fibers was observed under a microscope. The expressions of vascular endothelial growth factor (VEGF) and NDRG2/IL-6/STAT3 pathway genes in tissues were determined via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Furthermore, the expressions of NDRG2/IL-6/STAT3 pathway proteins were determined via Western blotting.The level of blood glucose in model group was significantly higher than that of control group (p<0.05), suggesting successful modeling. The levels of tumor necrosis factor-α (TNF-α), IL-6, and IL-1 in model group were significantly higher than those of control group (p<0.05). The content of ROS and MDA in tissues was significantly higher in model group than the other two groups (p<0.05). However, SOD increased markedly in CLT-005 group and was close to that of control group. Besides, the number of corneal nerve fibers decreased remarkably in model group. However, it increased significantly in CLT-005 group, but was still smaller than that in control group. According to HE staining, there were significant retinal edema and telangiectasia in model group. Mild retinal edema and more ganglion cells and inner nuclear layers were observed in CLT-005 group than model group. QRT-PCR demonstrated that the mRNA expressions of VEGF, NDRG2, IL-6, and STAT3 were remarkably higher in model group than those in control group (p<0.05). However, they decreased significantly in CLT-005 group (p<0.05). Model group exhibited remarkably higher protein expressions of NDRG2, IL-6, and STAT3 than control group (p<0.05). However, CLT-005 group had decreased protein expressions of these molecules (p<0.05), which were close to those in control group.The activation of NDRG2/IL-6/STAT3 signaling pathway is positively correlated with the occurrence and development of DR in rats. Therefore, inhibiting the activation of NDRG2/IL-6/STAT3 signaling pathway can affect oxidation and antioxidation, thereby exerting a protective effect against retinal injury in diabetes rats. |
| 2020 | Levetiracetam Reduces Early Inflammatory Response After Experimental Intracerebral Hemorrhage by Regulating the Janus Kinase 2 (JAK2)-Signal Transducer and Activator of Transcription 3 (STAT3) Signaling Pathway. | Med Sci Monit | BACKGROUND Levetiracetam (LEV) is an antiepileptic drug that promotes recovery of neurological function by alleviating inflammatory reactions. However, it is not known whether it can improve secondary brain injury after intracerebral hemorrhage (ICH). The aim of this study was to determine whether LEV can reduce early inflammatory response after ICH in rats. MATERIAL AND METHODS An in vitro model of early inflammation was created by treating microglia cells with lipopolysaccharide (LPS). After exposure to various concentrations of LEV, the expression levels of NF-kappaB and STAT3 and inflammatory factors such as interleukin (IL)-1ß and tumor necrosis factor (TNF)-alpha in microglia were detected. In vivo, autologous blood was used to induce the rat ICH model. The effects of LEV on post-cerebral hemorrhagic inflammatory response were examined using neurobehavioral tests, FJC staining, brain water content testing, and analysis of protein expression levels of NF-kappaB, JAK2, STAT3, and inflammatory factors. RESULTS LEV treatment significantly reduced the expression of inflammatory factors and protein expression levels of NF-kappaB and STAT3 in LPS-treated microglia cells (P<0.05). In male Sprague-Dawley (SD) rats, LEV treatment markedly decreased the volume of hematoma and the number of degenerative neurons (P<0.05). It also improved the neurological function and relieved brain edema. The protein expression levels of NF-kappaB, JAK2, and STAT3 were significantly lower in the ICH+LEV group than in the control group (P<0.05). CONCLUSIONS Our study suggests that treatment with LEV alleviates early inflammatory responses induced by ICH. Mechanistically, LEV inhibited the JAK2-STAT3 signaling pathway and reduced neuronal injury around the hematoma, and ameliorated brain edema, all of which promoted recovery of nerve function after hemorrhage. |
| 2020 | Ionizing radiation modulates vascular endothelial growth factor expression through STAT3 signaling pathway in rat neonatal primary astrocyte cultures. | Brain Behav | Radiation-induced brain injury (RBI) usually occurs six months to three years after irradiation, often shows cognitive dysfunction, epilepsy, and other neurological dysfunction. In severe cases, it can cause a wide range of cerebral edema, even herniation. It seriously threatens the survival of patients and their quality of life, and it becomes a key factor in limiting the radiation dose and lowering the therapeutic efficacy in recent years. Therefore, studying the pathogenesis of RBI and exploring new therapeutic targets are of great significance.In our study, we observed the activation and secretory function in astrocytes as well as the intracellular signal transducer and activator of transcription 3 (STAT3) signal transduction pathway activation status after exposing different doses of X-ray irradiation by using MTT, Immunocytologic analysis, and Western blot analysis. Further, we used the same way to explore the role of vascular endothelial growth factor (VEGF) in signal transduction pathways playing in the activation of astrocytes after irradiating through the use of specificInhivascular endothelial growth factorbitors of STAT3.Ast can be directly activated, reactive hyperplasia and hypertrophy, the expression of the activation marker glial fibrillary acidic protein is increased, and the expression of vascular endothelial growth factor (VEGF) in the cells is increased, which may lead to RBI. After the addition of STAT3 pathway inhibitor, most of the Ast radiation activation was suppressed, and the expression of high-level expression of VEGF decreased after irradiation.Our findings demonstrated that X-ray irradiation directly induced the activation of astrocytes in a persistent manner and X-ray irradiation activated STAT3 signaling pathway. As the same time, we found that X-ray irradiation induced the activation of astrocytes and secretion cytokine. The STAT3 signaling pathway may participate in the pathogenesis of radiation-induced brain injury. |
| 2020 | Sphingosine-1-phosphate signal transducer and activator of transcription 3 signaling pathway contributes to baicalein-mediated inhibition of dextran sulfate sodium-induced experimental colitis in mice. | Chin Med J (Engl) | Baicalein has been shown to have anti-inflammatory and anti-tumor activities. However, the mechanisms underlying its anti-inflammatory effect on colitis remain unclear.A dextran sodium sulfate (DSS)-induced model of acute colitis was established in BALB/c mice (6-8 weeks old, weighing 18-22 g). Six groups of mice received: (1) water for 10 days (control), n = 6; (2) DSS 4% solution in the drinking water for 7 days, followed by normal water for 3 days, n = 7; (3), (4), and (5) as for group 2 plus baicalein (10, 20, 40 mg/kg) administered once daily starting on day 1, n = 6; and (6) as for (2) plus 5-aminosalicylic acid (50 mg/kg) administered once daily starting on day 1, n = 6. Body weights, stool consistency, and hematochezia were recorded, and the severity of colitis was evaluated using a disease activity index. On day 11, the mice were euthanized, and organs and blood were collected for analysis. Serum inflammatory factors were detected by enzyme-linked immunosorbent assay; CD11b-positive cells were analyzed by immunofluorescence microscopy; expression of retinoic-acid-receptor-related orphan nuclear receptor gamma, sphingosine kinase 1 (SPHK1), and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) was detected by immunohistochemistry; and expression of nucleotide-binding oligomerization domain 2 (NOD2), SPHK1, sphingosine 1-phosphate receptor 1 (S1PR1), total STAT3, and p-STAT3 were detected by western blotting analysis. Inter-group differences were compared using Student's t test.Baicalein treatment dose-dependently reduced DSS-induced weight loss (P < 0.01 or P < 0.05), splenomegaly (P < 0.01), and colonic damage, as reflected by amelioration of diarrhea, rectal bleeding, and colonic ulceration, congestion, edema (shown as colon length, P < 0.05 or P < 0.01), and inflammatory cell infiltration. Baicalein also significantly decreased the levels of inflammatory mediators in the serum (P < 0.01) and colon, and significantly inhibited expression of NOD2 SPHK1, S1PR1, and p-STAT3 in the colon (P < 0.05).Baicalein treatment ameliorated colitis in mice by inhibiting S1P-STAT3 signaling, suggesting that this flavonoid might be beneficial in the treatment of colitis. |
| 2019 | Effect of SOCS3 on lung injury in rats with severe acute pancreatitis through regulating JAK2/STAT3 signaling pathway. | Eur Rev Med Pharmacol Sci | To explore the effect of suppressor of cytokine signaling 3 (SOCS3) on the lung injury in rats with severe acute pancreatitis (SAP) by regulating the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway.Sprague-Dawley rats were divided into control group (n=20) and SAP model group (established via injection of 5% sodium taurocholate, n=40). Then, SOCS3 was overexpressed using the adenovirus in 20 rats in SAP model group. The serum amylase (AMY) was detected, whether the transfection was successful was verified via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR), the hepatic function indexes were detected, the pathological changes were observed using hematoxylin-eosin (HE) staining, and the wet/dry weight ratio (W/D) was calculated. Moreover, the content of serum inflammatory factors was detected via enzyme-linked immunosorbent assay (ELISA) and the expression levels of JAK2/STAT3 signaling pathway genes and proteins were detected through RT-PCR and Western blotting.The content of AMY in SAP model group was significantly increased, indicating the successful modeling. SOCS3 was significantly increased in transfection group, suggesting that the transfection efficiency was significant. The content of alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in SOCS3 transfection group was significantly lower than in model group. According to the histopathological observation, there were lung injury, pulmonary edema, hemorrhage, severe inflammatory response, and alveolar congestion in SAP model group. There were almost no pathological changes in SOCS3 transfection group. In SOCS3 transfection group, the content of serum interleukin-6 (IL-6), IL-18 and tumor necrosis factor-α (TNF-α), the mRNA and protein expressions of IL-6, JAK2, and STAT3 were all remarkably declined.SOCS3 inhibits the activation of the JAK2/STAT3 pathway and the increase of inflammatory factors, promoting the repair of lung injury in SAP rats. |
| 2019 | [Correlation analysis of inflammatory response and Klotho expression in renal tissue of mice with acute renal injury induced by cisplatin]. | Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi | Objective To analyze the changes and correlation between inflammation and Klotho expression in kidney tissue of mice with acute kidney injury (AKI) induced by cisplatin, and to explore the role and possible mechanism of Klotho in AKI induced by cisplatin. Methods Eighteen male C57BL/6 mice were randomly divided into 0-day group, 1-day group and 3-day group with 6 mice in each group. The mice were killed at 0, 1 and 3 days after a single intraperitoneal injection of 25 mg/kg of cisplatin, and the serum and kidney tissues were collected. The content of serum creatinine (Scr) and blood urea nitrogen (BUN) were measured by biochemical analyzer, and the pathological changes of kidney tissues were observed by HE staining. Neutrophil gelatinase-associated lipocalin (NGAL), tumor necrosis factor α (TNF-α), NLR family pyrin domain containing 3 (NLRP3), Klotho, signal transducer and activator of transcription 3 (STAT3), phosphorylated STAT3 (p-STAT3), nuclear factor-kappa B (NF-κB), phosphorylated NF-kappa B (p-NF-κB) were detected by Western blot analysis. Spearman rank correlation test was used to analyze the correlations. Results The content of serum Scr and BUN in 1-day and 3-day groups were significantly higher than those in 0-day group, and inflammatory cell infiltration, renal tubular epithelial cell exfoliation, edema and accumulation of cell fragments were seen in 1-day and 3-day groups. In the 3-day group, the content of NGAL, TNF-α, NLRP3, p-STAT3, STAT3, p-NF-κB and NF-κB proteins in renal tissues significantly increased, and the expression of TNF-α, p-STAT3 and STAT3 increased in a time-dependent manner. The expression of Klotho decreased in a time-dependent manner in the 1-day and 3-day groups, and the expression of NGAL, TNF-α, NLRP3, p-STAT3, and p-NF-κB were significantly negatively correlated with the expression of Klotho. Conclusion The activation of STAT3/NF-κB pathway by Klotho is involved in the regulation of the occurrence and development of AKI induced by cisplatin in mice. |
| 2020 | Neurochemical regulation of the expression and function of glial fibrillary acidic protein in astrocytes. | Glia | Glial fibrillary acidic protein (GFAP), a type III intermediate filament, is a marker of mature astrocytes. The expression of GFAP gene is regulated by many transcription factors (TFs), mainly Janus kinase-2/signal transducer and activator of transcription 3 cascade and nuclear factor κ-light-chain-enhancer of activated B cell signaling. GFAP expression is also modulated by protein kinase and other signaling molecules that are elicited by neuronal activity and hormones. Abnormal expression of GFAP proteins occurs in neuroinflammation, neurodegeneration, brain edema-eliciting diseases, traumatic brain injury, psychiatric disorders and others. GFAP, mainly in α-isoform, is the major component of cytoskeleton and the scaffold of astrocytes, which is essential for the maintenance of astrocytic structure and shape. GFAP also has highly morphological plasticity because of its quick changes in assembling and polymerizing states in response to environmental challenges. This plasticity and its corresponding cellular morphological changes endow astrocytes the functions of physical barrier between adjacent neurons and stabilizer of extracellular environment. Moreover, GFAP colocalizes and even molecularly associates with many functional molecules. This feature allows GFAP to function as a platform for direct interactions between different molecules. Last, GFAP involves transportation and localization of other functional proteins and thus serves as a protein transport guide in astrocytes. This guiding role of GFAP involves an elastic retraction and extension cytoskeletal network that couples with GFAP reassembling, transporting, and membrane protein recycling machinery. This paper reviews our current understanding of the expression and functions of GFAP as well as their regulation. |
| 2019 | Angiopoietin-Like Protein 4 (ANGPTL4) Induces Retinal Pigment Epithelial Barrier Breakdown by Activating Signal Transducer and Activator of Transcription 3 (STAT3): Evidence from ARPE-19 Cells Under Hypoxic Condition and Diabetic Rats. | Med Sci Monit | BACKGROUND Diabetic retinopathy is a primary contributor of visual impairment in adult diabetes mellitus patients. Diabetic retinopathy causes breakdown of blood retinal barrier (BRB), and leads to diabetic macular edema. Previous studies have demonstrated angiopoietin-like protein 4 (ANGPTL4) as an effective diabetic retinopathy therapeutic target, however, its role in maintaining the outer BRB in diabetic retinopathy has yet not elucidated. MATERIAL AND METHODS We established an in vivo diabetic rat model with the use of streptozotocin injections and cultured ARPE-19 cells under (hypoxia, 1%) condition. We first investigated the expression of hypoxia induced factor-1alpha (HIF-1alpha) and ANGPTL4 in vivo and subsequently studied the transcriptional regulation and underlying molecular mechanisms in ARPE-19 cells under oxygen-deprived situations. RESULTS The expression of HIF-1alpha and ANGPTL4 was increased with diabetic retinopathy progression both in vivo and in vitro. Depletion of HIF-1alpha by siRNA inhibited hypoxia-induced ANGPTL4 expression. Repressing the HIF-1alpha/ANGPTL4 signaling effectively alleviated the migration and cellular permeability induced by hypoxia in ARPE-19 cells. Depletion of ANGPTL4 by siRNA significantly alleviated signal transducer and activator of transcription 3 (STAT3) activity in vitro, thereby attenuating the decrease of tight junction proteins occludin and zona occludens-1 (ZO-1) under hypoxia in ARPE-19 cells. CONCLUSIONS Our results suggest that ANGPTL4 partially modulates STAT3 and could serve as an effective diabetic retinopathy treatment strategy. |
| 2019 | Hirsutanol A Attenuates Lipopolysaccharide-Mediated Matrix Metalloproteinase 9 Expression and Cytokines Production and Improves Endotoxemia-Induced Acute Sickness Behavior and Acute Lung Injury. | Mar Drugs | Activated human monocytes/macrophages, which increase the levels of matrix metalloproteinases (MMPs) and pro-inflammatory cytokines, are the essential mechanisms for the progression of sepsis. In the present study, we determined the functions and mechanisms of hirsutanolA (HA), which is isolated from the red alga-derived marine fungus sp. NTOU4196, on the production of pro-inflammatory mediators produced from lipopolysaccharide (LPS)-treated THP-1 cells. Our results showed that HA suppressed LPS-triggered MMP-9-mediated gelatinolysis and expression of protein and mRNA in a concentration-dependent manner without effects on TIMP-1 activity. Also, HA significantly attenuated the levels of TNF-α, IL-6, and IL-1β from LPS-treated THP-1 cells. Moreover, HA significantly inhibited LPS-mediated STAT3 (Tyr705) phosphorylation, IκBα degradation and ERK1/2 activation in THP-1 cells. In an LPS-induced endotoxemia mouse model, studies indicated that HA pretreatment improved endotoxemia-induced acute sickness behavior, including acute motor deficits and anxiety-like behavior. HA also attenuated LPS-induced phospho-STAT3 and pro-MMP-9 activity in the hippocampus. Notably, HA reduced pathologic lung injury features, including interstitial tissue edema, infiltration of inflammatory cells and alveolar collapse. Likewise, HA suppressed the induction of phospho-STAT3 and pro-MMP-9 in lung tissues. In conclusion, our results provide pharmacological evidence that HA could be a useful agent for treating inflammatory diseases, including sepsis. |
| 2019 | Erythropoietin Ameliorates Lung Injury by Accelerating Pulmonary Endothelium Cell Proliferation via Janus Kinase-Signal Transducer and Activator of Transcription 3 Pathway After Kidney Ischemia and Reperfusion Injury. | Transplant Proc | Kidney ischemia and reperfusion injury could cause microvascular barrier dysfunction, lung inflammatory cascades activation, and programmed cell death of pulmonary endothelium, leading to acute lung injury. Our study aimed at determining whether erythropoietin (EPO) can ameliorate lung dysfunction following renal ischemia and reperfusion (IR) injury and explored the underlying mechanisms.In vivo, C57BL/6 mice received EPO (6000 U/kg) before right renal vascular pedicles clamping for 30 minutes, followed by 24 hours of reperfusion. The lung histopathologic changes and inflammatory cytokines expression were assessed. In vitro, cultured human umbilical vein endothelial cells were treated with EPO, and apoptosis rate, proliferation capacity, and phosphorylation status of the Janus kinase-signal transducer and activator of transcription 3 (Jak-STAT3) pathway were measured respectively in the presence or absence of lipopolysaccharide stimulation.In vivo, EPO remarkably attenuated pulmonary interstitial and alveolar epithelial edema caused by renal IR injury. In vitro, the proliferation capacity of human umbilical vein endothelial cells was significantly increased under EPO stimulation, which correlated with changes in Jak-STAT3 signaling.Our data indicated that EPO is able to ameliorate acute lung tissue damage induced by renal IR, and at least in part, via the Jak-STAT3 pathway. |
| 2019 | Papilledema from gain-of-function mutations in the STAT3 gene. | Ophthalmic Genet | Signal Transducer and Activator of Transcription 3 (STAT3) gain-of-function germline mutations are associated with diverse clinical manifestations, including autoimmune cytopenia, lymphadenopathy, immunodeficiency, endocrinopathy, and enteropathy. We describe a new feature: raised intracranial pressure with papilledema.Report of two cases.The first patient had a de novo heterozygous c.2144C>T (p.Pro715Leu) mutation in the STAT3 gene. At age 1 she had papilledema with marked sheathing of the proximal vessels on the optic discs. Follow-up 8 years later showed chronic papilledema, cystoid macular edema, and vision loss. The second patient had a de novo heterozygous c.2147C>T (p.Thr716Met) mutation. At age 12 he developed papilledema, which recurred despite treatment. In both patients, repeated sampling of the cerebrospinal fluid demonstrated a lymphocytic pleocytosis.Papilledema can occur as a manifestation of STAT3 gain-of-function mutation, sometimes accompanied by prominent vascular sheathing and cystoid macular edema. The mechanism may be chronic meningeal infiltration by white blood cells, impairing cerebrospinal fluid absorption. |
| 2019 | Anticolitic Effect of Viscum coloratum through Suppression of Mast Cell Activation. | Am J Chin Med | Viscum coloratum has been used as a component for traditional medicine for therapy of inflammatory diseases. Nonetheless, effect of Viscum coloratum on inflammatory bowel disease is unknown. Therefore, we investigated whether the ethanol extract of Viscum coloratum (VCE) could suppress inflammatory responses in dextran sodium sulfate (DSS)-treated mice and mast cell-derived inflammatory mediator (MDIM)-activated Caco-2 cells. VCE significantly attenuated body weight loss, shortened colon length, enteric epithelium disruption, enterorrhagia and colonic edema in DSS-treated mice. Additionally, VCE decreased the levels of immunoglobulin E, interleukin-6 and tumor necrosis factor- in serum and the activity of myeloperoxidase in colonic tissue. Moreover, VCE inhibited the infiltration of immune cells as well as the activity and expression of both matrix metalloprotease-2 and matrix metalloprotease-9. Furthermore, VCE restored zonula occludens-1 expression. Consistent with in vivo studies, VCE suppressed the activity and expression of matrix metalloprotease-2 and matrix metalloprotease-9 in MDIM-activated Caco-2 cells. In addition, VCE reinstated the expression of zonula occludens-1 through inhibiting activation of janus kinase 2/signal transducer and activator of transcription 3 in the cells. In conclusion, VCE exerts anticolitic action through inhibiting the activation of mast cells. Therefore, VCE may be useful as a phytomedicine or functional food for inflammatory bowel disease. |
| 2018 | Modified Citrus Pectin Prevents Blood-Brain Barrier Disruption in Mouse Subarachnoid Hemorrhage by Inhibiting Galectin-3. | Stroke | Background and Purpose- Plasma levels of galectin-3-a matricellular protein-are increased after aneurysmal subarachnoid hemorrhage (SAH), but the functional significance remains undetermined. This study was conducted to evaluate whether modified citrus pectin (MCP; galectin-3 inhibitor) prevents post-SAH early brain injury, focusing on blood-brain barrier disruption. Methods- C57BL/6 male adult mice (n=251) underwent sham or filament perforation SAH modeling, followed by a random intracerebroventricular injection of vehicle or drug at 30 minutes post-modeling. First, vehicle-treated and 0.8, 4, 16, or 32 µg MCP-treated mice were assessed by neuroscore and brain water content at 24 and 48 hours post-modeling. Second, Evans blue extravasation, Western blotting, coimmunoprecipitation and immunostaining were performed in vehicle-treated or 4 µg MCP-treated mice at 24 hours post-modeling. Third, vehicle or R-galectin-3 (recombinant galectin-3) was administered to SAH mice simultaneously with vehicle or MCP, and neuroscore and Evans blue extravasation were evaluated at 24 hours post-modeling. Fourth, vehicle or R-galectin-3 was administered to MCP-treated SAH mice at 24 hours, and neuroscore and IgG immunostaining were evaluated at 48 hours post-SAH. Results- Among tested dosages, 4 µg MCP showed the best neuroprotective effects as to preventing neurological impairments and brain edema at 24 to 48 hours post-SAH. Four micrograms MCP attenuated post-SAH blood-brain barrier disruption and galectin-3 upregulation in brain capillary endothelial cells, associated with inactivation of ERK (extracellular signal-related kinase) 1/2, STAT (signal transducer and activator of transcription)-3, and MMP (matrix metalloproteinase)-9, and the consequent preservation of a tight junction protein ZO-1 (zonula occludens-1). Coimmunoprecipitation assay demonstrated physical interactions between galectin-3 and TLR (Toll-like receptor) 4. R-galectin-3 blocked the neuroprotective effects of MCP. Conclusions- MCP prevents post-SAH blood-brain barrier disruption possibly by inhibiting galectin-3, of which the mechanisms may include binding to TLR4 and activating ERK1/2, STAT-3, and MMP-9. This study suggests galectin-3 to be a novel therapeutic target against post-SAH early brain injury. |
| 2018 | Ilex asprella aqueous extracts exert in vivo anti-inflammatory effects by regulating the NF-κB, JAK2/STAT3, and MAPK signaling pathways. | J Ethnopharmacol | Ilex asprella (Hook. et Arn.) Champ. ex Benth. (IA) is a representative medicinal plant from the South of the Five Ridges of China. Its roots (RIA) and stems (SIA) have been traditionally used for the inflammation-related diseases, such as acute and chronic pharyngitis, cough, and sore throats.To evaluate the in vivo anti-inflammatory effects of IA extracts to provide evidence for its traditional use and to enhance the knowledge of the medicinal properties of IA.Models of xylene-induced ear edema in mice and carrageenan-induced paw edema in rats were used for the pharmacological evaluations. The mice were randomly divided into eight groups (n = 10 per group): a model group, a positive control group [dexamethasone (Dex), 10 mg/kg, intragastrically (i.g.)], RIA aqueous extract groups with three dosages (30, 15, and 7.5 mg/kg, i.g.), and SIA aqueous extract groups with three dosages (60, 30, and 15 mg/kg, i.g.). The rats were randomly divided into eight groups (n = 6 per group): a model group, a positive control group [acetylsalicylic acid (ASA), 300 mg/kg, i.g.], RIA groups with three dosages (80, 40, and 20 mg/kg, i.g.) and SIA aqueous extract groups with three dosages (160, 80, and 40 mg/kg, i.g.). Histological examinations of the ear and paw tissues were observed by hematoxylin-eosin (HE) staining, and neutrophil elastase levels were assessed in ear tissues by immunohistochemical analysis. Serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) were measured by ELISAs, and expression levels of TNF-α, IL-6, and IL-1β in rat paw tissues were measured by RT-PCR. The signal transduction proteins p65, IκBα, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), p38 mitogen-activated protein kinases (p38), extracellular regulated protein kinases (ERK1/2), and c-Jun N-terminal kinase (JNK) in the rat paw tissues were investigated by western blot analyses. RIA and SIA were characterized by HPLC and LC-MS analyses, and the components were confirmed by comparison with isolated compounds.Intragastric administration with RIA (30 mg/kg) and SIA (60, 30 mg/kg) significantly mitigated ear edema in mice. RIA administration at 80 and 40 mg/kg reduced paw edema in rats 2‒3 h after injection. SIA administration with 160 mg/kg inhibited paw edema in rats after the injection of carrageenan for 1‒4 h, and SIA administration at 80 mg/kg inhibited paw edema after the injection of carrageenan for 2‒4 h. Meanwhile, RIA (80, 40 mg/kg) and SIA (160, 80 mg/kg) reduced inflammatory cell infiltration in the ear and paw tissues and infiltration of neutrophil leukocytes in rat paw tissues. RIA (80, 40, and 20 mg/kg) and SIA (160, 80, and 40 mg/kg) notably inhibited the increases of TNF-α, IL-6 and IL-1β in the serum and mRNA expression in the rat paw tissues. RIA (80, 40 mg/kg) and SIA (160, 80 mg/kg) reduced the p-p65/p-IκBα, p-JAK2/p-STAT3, and p-p38/p-ERK1/2/p-JNK levels in the pathological tissues of the animals. Phenolic acids and triterpenoids likely contributed to the anti-inflammatory activity.Both RIA and SIA aqueous extracts showed anti-inflammatory effects in vivo in a dose-independent manner (20‒80 and 40‒160 mg/kg, respectively). The underlying mechanisms are mediated by inhibiting the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β via regulation of the NF-κB, JAK2/STAT3, and MAPK signaling pathways. The present results provided pharmacological evidence that stems are alternative medicinal parts of IA but function at different doses. Additionally, this study supports the use of IA as an anti-inflammatory herbal medicine. |
| 2018 | Transient High Pressure in Pancreatic Ducts Promotes Inflammation and Alters Tight Junctions via Calcineurin Signaling in Mice. | Gastroenterology | Pancreatitis after endoscopic retrograde cholangiopancreatography (PEP) is thought to be provoked by pancreatic ductal hypertension, via unknown mechanisms. We investigated the effects of hydrostatic pressures on the development of pancreatitis in mice.We performed studies with Swiss Webster mice, B6129 mice (controls), and B6129 mice with disruption of the protein phosphatase 3, catalytic subunit, βisoform gene (Cnab mice). Acute pancreatitis was induced in mice by retrograde biliopancreatic ductal or intraductal infusion of saline with a constant hydrostatic pressure while the proximal common bile duct was clamped -these mice were used as a model of PEP. Some mice were given pancreatic infusions of adeno-associated virus 6-nuclear factor of activated T-cells-luciferase to monitor calcineurin activity or the calcineurin inhibitor FK506. Blood samples and pancreas were collected at 6 and 24 hours and analyzed by enzyme-linked immunosorbent assay, histology, immunohistochemistry, or fluorescence microscopy. Ca signaling and mitochondrial permeability were measured in pancreatic acinar cells isolated 15 minutes after PEP induction. Ca-activated phosphatase calcineurin within the pancreas was tracked in vivo over 24 hours.Intraductal pressures of up to 130 mm Hg were observed in the previously reported model of PEP; we found that application of hydrostatic pressures of 100 and 150 mm Hg for 10 minutes consistently induced pancreatitis. Pancreatic tissues had markers of inflammation (increased levels of interleukin [IL] 6, IL1B, and tumor necrosis factor), activation of signal transducer and activator of transcription 3, increased serum amylase and IL6, and loss of tight junction integrity. Transiently high pressures dysregulated Ca processing (reduced Ca oscillations and an increased peak plateau Ca signal) and reduced the mitochondrial membrane potential. We observed activation of pancreatic calcineurin in the pancreas in mice. Cnab mice, which lack the catalytic subunit of calcineurin, and mice given FK506 did not develop pressure-induced pancreatic inflammation, edema, or loss of tight junction integrity.Transient high ductal pressure produces pancreatic inflammation and loss of tight junction integrity in a mouse model of PEP. These processes require calcineurin signaling. Calcineurin inhibitors might be used to prevent acute pancreatitis that results from obstruction. |
| 2018 | Arthroprotective Effects of Cf-02 Sharing Structural Similarity with Quercetin. | Int J Mol Sci | In this study, we synthesized hundreds of analogues based on the structure of small-molecule inhibitors (SMIs) that were previously identified in our laboratory with the aim of identifying potent yet safe compounds for arthritis therapeutics. One of the analogues was shown to share structural similarity with quercetin, a potent anti-inflammatory flavonoid present in many different fruits and vegetables. We investigated the immunomodulatory effects of this compound, namely 6-(2,4-difluorophenyl)-3-(3-(trifluoromethyl)phenyl)-2-benzo[][1,3]oxazine-2,4(3)-dione (Cf-02), in a side-by-side comparison with quercetin. Chondrocytes were isolated from pig joints or the joints of patients with osteoarthritis that had undergone total knee replacement surgery. Several measures were used to assess the immunomodulatory potency of these compounds in tumor necrosis factor (TNF-α)-stimulated chondrocytes. Characterization included the protein and mRNA levels of molecules associated with arthritis pathogenesis as well as the inducible nitric oxide synthase (iNOS)⁻nitric oxide (NO) system and matrix metalloproteinases (MMPs) in cultured chondrocytes and proteoglycan, and aggrecan degradation in cartilage explants. We also examined the activation of several important transcription factors, including nuclear factor-kappaB (NF-κB), interferon regulatory factor-1 (IRF-1), signal transducer and activator of transcription-3 (STAT-3), and activator protein-1 (AP-1). Our overall results indicate that the immunomodulatory potency of Cf-02 is fifty-fold more efficient than that of quercetin without any indication of cytotoxicity. When tested in vivo using the induced edema method, Cf-02 was shown to suppress inflammation and cartilage damage. The proposed method shows considerable promise for the identification of candidate disease-modifying immunomodulatory drugs and leads compounds for arthritis therapeutics. |
| 2018 | AG490 ameliorates early brain injury via inhibition of JAK2/STAT3-mediated regulation of HMGB1 in subarachnoid hemorrhage. | Exp Ther Med | High mobility group box 1 (HMGB1) is a classic damage-associated molecular pattern that has an important role in the pathological inflammatory response. studies have demonstrated that the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway is involved in the regulation of HMGB1 expression, mediating the inflammatory response. Therefore, the purpose of the present study was to evaluate JAK2/STAT3 pathway involvement in the subarachnoid hemorrhage (SAH)-dependent regulation of HMGB1, using an rat model. A SAH model was established by endovascular perforation. Western blotting, immunohistochemistry and immunofluorescence were used to analyze HMGB1 expression after SAH. In addition, the effects of AG490 after SAH on JAK2/STAT3 phosphorylation, HMGB1 expression and brain damage were evaluated. The results of the present study demonstrated that JAK2/STAT3 was significantly phosphorylated (P<0.05) and the total HMGB1 protein level was significantly increased (P<0.05) after SAH. In addition, the cytosolic HMGB1 level after SAH demonstrated an initial increase followed by a decrease to the control level, while the nuclear HMGB1 level after SAH demonstrated the opposite trend, with an initial decrease and subsequent increase. AG490 administration after SAH significantly inhibited JAK2/STAT3 phosphorylation (P<0.05), suppressed the expression and translocation of HMGB1, reduced cortical apoptosis, brain edema and neurological deficits. These results demonstrated the involvement of the JAK2/STAT3 pathway in HMGB1 regulation after SAH. |
| 2017 | EGF stimulates glioblastoma metastasis by induction of matrix metalloproteinase-9 in an EGFR-dependent mechanism. | Oncotarget | Epidermal growth factor (EGF) and EGF receptor (EGFR) play prominent roles in the metastasis of glioblastoma (GBM). However, the molecular mechanisms for the function of EGF and EGFR in GBM metastasis have not been elucidated. Herein, we demonstrate that coactivation of EGF and EGFR drives tumor metastasis in a matrix metalloproteinase-9 (MMP-9)-dependent manner. Expression levels of EGF, EGFR, and MMP-9 were substantially upregulated in the GBM and edema zones of patients, compared with those of paired unaffected participants. Secretion of EGF and MMP-9 was reduced in the cerebrospinal fluid (CSF) after removing GBM for 2 weeks by operation. To the mechanism, MMP-9 was upregulated by activating EGF and EGFR via PI3K/AKT- and ERK1/2-dependent pathways. Moreover, signal transducer and activator of transcription (STAT) 3 and STAT5 mediated the activation of NF-κB by PI3K/AKT and ERK1/2 pathways. This resulted in transactivation of MMP-9 in GBM. Finally, MMP-9 induction facilitated abnormal proliferation, migration, and invasion of cells, which contributed to GBM metastasis. |
| 2018 | Anti-Inflammatory Effects of Boldine and Reticuline Isolated from Litsea cubeba through JAK2/STAT3 and NF-κB Signaling Pathways. | Planta Med | The anti-inflammatory effects of boldine and reticuline isolated from were evaluated by using xylene-induced ear edema and carrageenan-induced paw edema in mice and rats. Our results demonstrated that intragastric administration with boldine and reticuline significantly mitigated ear weight in mice and decreased paw volume in rats. A combination administration of boldine (0.5 mg/kg) + reticuline (0.25 mg/kg) resulted in a potentiated inhibition in these two models. In parallel, boldine or reticuline reduce the infiltration of neutrophil leukocytes in rat paw tissue, respectively, and the combination of the two groups performed a better anti-inflammatory activity as shown in histopathologies. Boldine, reticuline, and their combination notably inhibited mRNA expressions of TNF-, and IL-6 and reduced the phosphorylation levels of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). Beyond that, their combination also can reduce the phosphorylation levels of p65 and IB in the pathological tissues of animals, as observed by real-time PCR and western blot analyses, respectively. These findings indicate for the first time that boldine and reticuline have not only anti-inflammatory activity but also potential synergistic effects . The underlying mechanism may relate to the inhibition on the expression of pro-inflammatory cytokines, such as TNF- and IL-6, which may be a consequence of JAK2/STAT3 and NF-B pathway involvements. This study provides useful data for further exploration and application of boldine and reticuline as potential anti-inflammatory medicines. |
| 2016 | Decreased STAT3 Phosphorylation Mediates Cell Swelling in Ammonia-Treated Astrocyte Cultures. | Biology (Basel) | Brain edema, due largely to astrocyte swelling, and the subsequent increase in intracranial pressure and brain herniation, are major complications of acute liver failure (ALF). Elevated level of brain ammonia has been strongly implicated in the development of astrocyte swelling associated with ALF. The means by which ammonia brings about astrocyte swelling, however, is incompletely understood. Recently, oxidative/nitrosative stress and associated signaling events, including activation of mitogen-activated protein kinases (MAPKs), as well as activation of the transcription factor, nuclear factor-kappaB (NF-κB), have been implicated in the mechanism of ammonia-induced astrocyte swelling. Since these signaling events are known to be regulated by the transcription factor, signal transducer and activator of transcription 3 (STAT3), we examined the state of STAT3 activation in ammonia-treated cultured astrocytes, and determined whether altered STAT3 activation and/or protein expression contribute to the ammonia-induced astrocyte swelling. STAT3 was found to be dephosphorylated (inactivated) at Tyrosine705 in ammonia-treated cultured astrocytes. Total STAT3 protein level was also reduced in ammonia-treated astrocytes. We also found a significant increase in protein tyrosine phosphatase receptor type-1 (PTPRT-1) protein expression in ammonia-treated cultured astrocytes, and that inhibition of PTPRT-1 enhanced the phosphorylation of STAT3 after ammonia treatment. Additionally, exposure of cultured astrocytes to inhibitors of protein tyrosine phosphatases diminished the ammonia-induced cell swelling, while cultured astrocytes over-expressing STAT3 showed a reduction in the astrocyte swelling induced by ammonia. Collectively, these studies strongly suggest that inactivation of STAT3 represents a critical event in the mechanism of the astrocyte swelling associated with acute liver failure. |
| 2016 | Guggulsterone and Its Role in Chronic Diseases. | Adv Exp Med Biol | Guggulsterone is a plant sterol derived from gum resin of Commiphora wightii. The gum resin from guggul plants has been used for thousand years in Ayurveda to treat various disorders, including internal tumors, obesity, liver disorders, malignant sores and ulcers, urinary complaints, intestinal worms, leucoderma, sinuses, edema, and sudden paralytic seizures. Guggulsterone has been identified a bioactive components of this gum resin. This plant steroid has been reported to work as an antagonist of certain nuclear receptors, especially farnesoid X receptor, which regulates bile acids and cholesterol metabolism. Guggulsterone also mediates gene expression through the regulation of transcription factors, including nuclear factor-kappa B and signal transducer and activator of transcription 3, which plays important roles in the development of inflammation and tumorigenesis. Guggulsterone has been shown to downregulate the expression of proteins involved in anti-apoptotic, cell survival, cell proliferation, angiogenic, metastatic, and chemoresistant activities in tumor cells. This review aimed to clarify the cell signal pathways targeted by guggulsterone and the bioactivities of guggulsterone in animal models and humans. |
| 2014 | Anti-inflammatory and joint protective effects of extra-virgin olive-oil polyphenol extract in experimental arthritis. | J Nutr Biochem | The consumption of extra virgin olive oil (EVOO) in Mediterranean countries has shown beneficial effects. A wide range of evidence indicates that phenolic compounds present in EVOO are endowed with anti-inflammatory properties. In this work, we evaluated the effects of EVOO-polyphenol extract (PE) in a model of rheumatoid arthritis, the collagen-induced arthritis model in mice. On day 0, DBA-1/J mice were immunized with bovine type II collagen. On day 21, mice received a booster injection. PE (100 and 200 mg/kg) was orally administered once a day from days 29 to 41 to arthritic mice. We have demonstrated that PE decreases joint edema, cell migration, cartilage degradation and bone erosion. PE significantly reduced the levels of proinflammatory cytokines and prostaglandin E2 in the joint as well as the expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1. Our data indicate that PE inhibits c-Jun N-terminal kinase, p38 and signal transducer and activator of transcription-3. In addition, PE decreases nuclear factor κB translocation leading to the down-regulation of the arthritic process. These results support the interest of natural diet components in the development of therapeutic products for arthritic conditions. |
| 2014 | Protection of granulocyte-colony stimulating factor to hemorrhagic brain injuries and its involved mechanisms: effects of vascular endothelial growth factor and aquaporin-4. | Neuroscience | Granulocyte-colony stimulating factor (G-CSF) has protective effects on many neurological diseases. Here, we aimed to test G-CSF's effects on perihematomal tissue injuries following intracerebral hemorrhage (ICH) and examine whether the effects were functionally dependent on vascular endothelial growth factor (VEGF) and aquaporin-4 (AQP4). We detected the expression of perihematomal VEGF, VEGF receptors (VEGFRs) and AQP4 at 1, 3 and 7days after ICH. Also, we examined the effects of G-CSF on tissue injuries by ICH in wild type mice, and tested whether such effects were VEGF and AQP4 dependent by using VEGFR inhibitor - SU5416 and AQP4 knock-out (AQP4(-/-)) mice. Furthermore, we assessed the related signal transduction pathways via astrocyte cultures. We found G-CSF highly increased perihematomal VEGF, VEGFR-2 and AQP4. Importantly, G-CSF led to neurological functional improvement in both types of mice by associating with reduction of brain edema, blood-brain barrier (BBB) permeability and neuronal death and apoptosis and statistical analysis suggested AQP4 was required for these effects. Besides, except BBB leakage alleviation, the above effects were attenuated but not counteracted by SU5416, suggesting involvement of VEGF. G-CSF up-regulated phosphorylation of extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription 3 (STAT3) as well as VEGF and AQP4 proteins in cultured astrocytes. The latter was inhibited by ERK and STAT3 inhibitors respectively. Our data suggest the protective effects of G-CSF on perihematomal tissue injuries after ICH are highly associated with the increased levels of VEGF and AQP4, possibly act through C-Jun amino-terminal kinase and ERK pathways respectively. |
| 2013 | Anti-inflammation of spirocyclopiperazinium salt compound LXM-10 targeting α7 nAChR and M4 mAChR and inhibiting JAK2/STAT3 pathway in rats. | PLoS One | The present study aims to investigate the therapeutic effects of LXM-10 by intragastric administration in both acute and chronic inflammatory models, and to explore the underlying molecular mechanisms. The results showed that LXM-10 produced significant anti-inflammatory effects on carrageenan induced paw edema and complete Freund's adjuvant (CFA) induced arthritis, in which LXM-10 inhibited paw swelling in a dose- and time-dependent manner. ELISA analysis showed the production of pro-inflammatory cytokines including TNF-α and IL-6 was decreased by LXM-10. Western blot analysis showed that LXM-10 significantly reduced phosphorylation of Janus kinase 2 (JAK2) and further blunted phosphorylation of signal transducer and activator of transcription-3 (STAT3). The effects that LXM-10 had shown were attenuated by methyllycaconitine citrate (an α7 nicotinic acetylcholine receptor antagonist) or tropicamide (an M4 muscarinic acetylcholine receptor antagonist) in vivo. In conclusion, the studies showed that intragastric administration of LXM-10 exerted significant anti-inflammation effects in acute and chronic models, which may be attribute to the activation of α7 nicotinic acetylcholine receptor and M4 muscarinic acetylcholine receptor, thereby inhibiting the JAK2/STAT3 signal pathway, and ultimately reducing the production of pro-inflammatory cytokines of TNF-α and IL-6. |
| 2013 | CXCR4 negatively regulates keratinocyte proliferation in IL-23-mediated psoriasiform dermatitis. | J Invest Dermatol | CXCR4 is expressed by basal keratinocytes (KCs), but little is known about its function in inflamed skin. We crossed K14-Cre and CXCR4(flox/flox (f/f)) transgenic mice, resulting in mice with specific loss of the CXCR4 gene in K14-expressing cells (K14-CXCR4KO), including basal KCs. K14-CXCR4KO pups had no obvious skin defects. We compared K14-CXCR4KO and CXCR4(f/f) control mice in an IL-23-mediated psoriasiform dermatitis model and measured skin edema, and histologic and immunohistological changes. IL-23-treated K14-CXCR4KO mice showed a 1.3-fold increase in mean ear swelling, a 2-fold increase in epidermal thickness, and greater parakeratosis. IL-23-treated wild-type (WT) mice showed weak CXCR4 expression in areas of severe epidermal hyperplasia, but strong CXCR4 expression in nonhyperplastic regions, suggesting that CXCR4 may regulate KC proliferation. To test this hypothesis, we overexpressed CXCR4 in HaCaT KC cells and treated them with IL-22 and/or CXCL12 (chemokine (C-X-C motif) ligand 12). CXCL12 blocked IL-22-mediated HaCaT cell proliferation in vitro and synergized with IL-22 in upregulating SOCS3 (suppressor of cytokine signaling 3), a key regulator of STAT3 (signal transducer and activator of transcription 3). SOCS3 was required for CXCR4-mediated growth inhibition. In human psoriatic skin, both CXCR4 and SOCS3 were upregulated in the junctional region at the border of psoriatic plaques. Thus, CXCR4 has an unexpected role in inhibiting KC proliferation and mitigating the effects of proliferative T helper type 17 cytokines. |
| 2011 | A highly selective, orally active inhibitor of Janus kinase 2, CEP-33779, ablates disease in two mouse models of rheumatoid arthritis. | Arthritis Res Ther | Janus kinase 2 (JAK2) is involved in the downstream activation of signal transducer and activator of transcription 3 (STAT3) and STAT5 and is responsible for transducing signals for several proinflammatory cytokines involved in the pathogenesis of rheumatoid arthritis (RA), including interleukin (IL)-6, interferon γ (IFNγ) and IL-12. In this paper, we describe the efficacy profile of CEP-33779, a highly selective, orally active, small-molecule inhibitor of JAK2 evaluated in two mouse models of RA.Collagen antibody-induced arthritis (CAIA) and collagen type II (CII)-induced arthritis (CIA) were established before the oral administration of a small-molecule JAK2 inhibitor, CEP-33779, twice daily at 10 mg/kg, 30 mg/kg, 55 mg/kg or 100 mg/kg over a period of 4 to 8 weeks.Pharmacodynamic inhibition of JAK2 reduced mean paw edema and clinical scores in both CIA and CAIA models of arthritis. Reduction in paw cytokines (IL-12, IFNγ and tumor necrosis factor α) and serum cytokines (IL-12 and IL-2) correlated with reduced spleen CII-specific T helper 1 cell frequencies as measured by ex vivo IFNγ enzyme-linked immunosorbent spot assay. Both models demonstrated histological evidence of disease amelioration upon treatment (for example, reduced matrix erosion, subchondral osteolysis, pannus formation and synovial inflammation) and reduced paw phosphorylated STAT3 levels. No changes in body weight or serum anti-CII autoantibody titers were observed in either RA model.This study demonstrates the utility of using a potent and highly selective, orally bioavailable JAK2 inhibitor for the treatment of RA. Using a selective inhibitor of JAK2 rather than pan-JAK inhibitors avoids the potential complication of immunosuppression while targeting critical signaling pathways involved in autoimmune disease progression. |
| 2010 | Reperfusion and neurovascular dysfunction in stroke: from basic mechanisms to potential strategies for neuroprotection. | Mol Neurobiol | Effective stroke therapies require recanalization of occluded cerebral blood vessels. However, reperfusion can cause neurovascular injury, leading to cerebral edema, brain hemorrhage, and neuronal death by apoptosis/necrosis. These complications, which result from excess production of reactive oxygen species in mitochondria, significantly limit the benefits of stroke therapies. We have developed a focal stroke model using mice deficient in mitochondrial manganese-superoxide dismutase (SOD2-/+) to investigate neurovascular endothelial damage that occurs during reperfusion. Following focal stroke and reperfusion, SOD2-/+ mice had delayed blood-brain barrier breakdown, associated with activation of matrix metalloproteinase and high brain hemorrhage rates, whereas a decrease in apoptosis and hemorrhage was observed in SOD2 overexpressors. Thus, induction and activation of SOD2 is a novel strategy for neurovascular protection after ischemia/reperfusion. Our recent study identified the signal transducer and activator of transcription 3 (STAT3) as a transcription factor of the mouse SOD2 gene. During reperfusion, activation of STAT3 and its recruitment into the SOD2 gene were blocked, resulting in increased oxidative stress and neuronal apoptosis. In contrast, pharmacological activation of STAT3 induced SOD2 expression, which limits ischemic neuronal death. Our studies point to antioxidant-based neurovascular protective strategies as potential treatments to expand the therapeutic window of currently approved therapies. |
| 2009 | Glucagon-like peptide-1 receptor activation modulates pancreatitis-associated gene expression but does not modify the susceptibility to experimental pancreatitis in mice. | Diabetes | Clinical reports link use of the glucagon-like peptide-1 receptor (GLP-1R) agonists exenatide and liraglutide to pancreatitis. However, whether these agents act on the exocrine pancreas is poorly understood.We assessed whether the antidiabetic agents exendin (Ex)-4, liraglutide, the dipeptidyl peptidase-4 inhibitor sitagliptin, or the biguanide metformin were associated with changes in expression of genes associated with the development of experimental pancreatitis. The effects of Ex-4 when administered before or after the initiation of caerulein-induced experimental pancreatitis were determined. The importance of endogenous GLP-1R signaling for gene expression in the exocrine pancreas and the severity of pancreatitis was assessed in Glp1r(-/-) mice.Acute administration of Ex-4 increased expression of egr-1 and c-fos in the exocrine pancreas. Administration of Ex-4 or liraglutide for 1 week increased pancreas weight and induced expression of mRNA transcripts encoding the anti-inflammatory proteins pancreatitis-associated protein (PAP) (RegIIIbeta) and RegIIIalpha. Chronic Ex-4 treatment of high-fat-fed mice increased expression of PAP and reduced pancreatic expression of mRNA transcripts encoding for the proinflammatory monocyte chemotactic protein-1, tumor necrosis factor-alpha, and signal transducer and activator of transcription-3. Sitagliptin and metformin did not significantly change pancreatic gene expression profiles. Ex-4 administered before or after caerulein did not modify the severity of experimental pancreatitis, and levels of pancreatic edema and serum amylase were comparable in caerulein-treated Glp1r(-/-) versus Glp1r(+/+) mice.These findings demonstrate that GLP-1 receptor activation increases pancreatic mass and selectively modulates the expression of genes associated with pancreatitis. However, activation or genetic elimination of GLP-1R signaling does not modify the severity of experimental pancreatitis in mice. |
| 2007 | Edema-induced intestinal dysfunction is mediated by STAT3 activation. | Shock | Increased signal transducer and activator of transcription 3 (STAT3) activation has been shown to be associated with intestinal dysfunction. The purpose of this study was to investigate the role of STAT3 in edema-induced intestinal dysfunction. Intestinal edema was induced in male Sprague-Dawley rats by a combination of mesenteric venous hypertension and fluid resuscitation (RESUS + VH). Resuscitation fluid alone (RESUS), venous hypertension alone (VH), and sham-operated rats (CONTROL) were used as controls. Edema development, STAT3 DNA binding activity, nuclear translocation, and phosphorylation were measured in rat distal small intestinal muscularis. A significant amount of edema development was measured in the RESUS + VH rats compared with CONTROL and VH from 30 min to 6 h after surgery. Edema developed in the RESUS group at 30 min postsurgery but resolved before 2 h postsurgery. A significant increase in STAT3 DNA binding activity was observed from 30 min to 6 h after surgery in the edematous RESUS + VH group compared with nonedematous CONTROL. In addition, a significant increase in STAT3 nuclear translocation and phosphorylation was measured in the RESUS + VH group 2 and 6 h after surgery. No significant increases in STAT3 activation were observed in either the RESUS or VH groups compared with CONTROL. Rats in both the RESUS + VH and CONTROL groups were pretreated with AG490 (5 mg/kg, i.p.) to block STAT3 activation. Signal transducer and activator of transcription 3 inhibition attenuated edema-induced decrease in intestinal contractile activity and myosin light chain phosphorylation. We conclude from these data that edema-induced decreases in intestinal contractile activity are mediated, at least in part, by STAT3 activation. |