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Objective:To explore the effect of signal transducer and activator of transcription 6 (STAT6) on ferroptosis in skeletal muscle cells in sepsis model and its potential mechanism.Methods:Twenty-four 8-week-old male specific pathogen free Kunming mice were divided into normal control group, sham group, sepsis model group and STAT6 inhibitor pretreatment group according to random number table method with 6 mice in each group. A mouse sepsis model was reproduced by cecal ligation and perforation (CLP). In the sham group, the skin of mice was sutured after exposing the cecum tissue. In the STAT6 inhibitor pretreatment group, 10 mg/kg AS1517499 was injected intraperitoneally 1 hour before model reproduction. The sham group and the model group were intraperitoneally injected with the same volume of normal saline. Mice in the normal control group did not receive any operation or drug intervention. The mice were sacrificed 24 hours after model reproduction, and the muscle tissue of hind limb was obtained under sterile condition. Hematoxylin-eosin (HE) staining was used to observe the histopathology with optical microscope, and mitochondrial morphological changes were observed by transmission electron microscopy after double staining with uranium acetate lead citrate. The ferroptosis marker proteins expressions of chitinase-3-like protein 1 (CHI3L1), cyclooxygenase-2 (COX-2), acyl-CoA synthetase long-chain family member 4 (ACSL4), ferritin heavy chain 1 (FTH1), and glutathione peroxidase 4 (GPx4) were detected by Western blotting.Results:Under the optical microscope, the morphology and structure of skeletal muscle tissues in the normal control and sham groups were normal. In the model group, the structure of skeletal muscle tissues was loose, the muscle fiber became smaller and atrophic, inflammatory cell infiltration and even muscle fiber loss were found. Compared with the model group, the structure of skeletal muscle tissues was tight and skeletal muscle atrophy was improved in the STAT6 inhibitor pretreatment group. The ultrastructure of skeletal muscle cell in the normal control and sham groups was normal under transmission electron microscope. The ultrastructure characteristics of skeletal muscle in the model group showed that cell membrane was broken and blister, mitochondria became smaller and membrane density increased, the mitochondrial crista decreased or disappeared, the mitochondrial outer membrane was broken, and the nucleus was normal in size but lacked chromatin condensation. Compared with the model group, the STAT6 inhibitor pretreatment group had a significant improvement in the ultrastructure of muscle cells. Compared with the normal control and sham groups, the protein expressions of CHI3L1, COX-2, ACSL4 and FTH1 in the muscle of the model group were significantly increased, while the protein expression of GPx4 was decreased significantly, indicating that the skeletal muscle cells in the mouse sepsis model showed characteristic mitochondrial injury and abnormal expression of ferroptosis markers. Compared with the model group, the protein expressions of CHI3LI, COX-2, ACSL4 and FTH1 in the STAT6 inhibitor pretreatment group were significantly decreased [CHI3L1 protein (CHI3L1/GAPDH): 0.70±0.08 vs. 0.97±0.09, COX-2 protein (COX-2/GAPDH): 0.61±0.03 vs. 0.83±0.03, ACSL4 protein (ACSL4/GAPDH): 0.75±0.04 vs. 1.02±0.16, FTH1 protein (FTH1/GAPDH): 0.49±0.06 vs. 0.76±0.13, all P < 0.05], while the protein expression of GPx4 was significantly increased (GPx4/GAPDH: 1.14±0.29 vs. 0.53±0.03, P < 0.05). Conclusions:Sepsis can induce ferroptosis in skeletal muscle cells of mice. STAT6 may mediate ferroptosis in mouse skeletal muscle cells by regulating the expressions of COX-2, ACSL4, FTH1 and GPx4, thereby inducing skeletal muscle cell injury in sepsis.
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OBJECTIVE: To investigate the protein expression of CC chemokine ligand 1 (CCL1) and CC chemokine receptor 8 (CCR8) in the lung tissue of rats and the mechanism of acupuncture and moxibustion at "Feishu"(BL13), "Dazhui" (GV14) and "Fengmen"(BL12) in the treatment of asthma. METHODS: Sprague-Dawley rats were randomly divided into blank， model, acupuncture and moxibustion groups，n=10 in each group. Ovalbumin sensitization via intraperitoneal injection was performed to establish a model of asthma. The rats in the acupuncture group and the moxibustion group were given acupuncture for 20 min or circling moxibustion for 10 min at BL13, GV14 and BL12, once a day for 7 days. H.E. staining was used to observe the morphological changes of lung tissue. Real-time fluorescence quantitative PCR was used to measure the mRNA expression of signal transducer and activator of transcription 6 (STAT6) in lung tissue and immunohistochemistry was used to measure the protein expression of CCL1 and CCR8 in lung tissue. RESULTS: H.E. staining showed that the rats in the blank group had regular bronchial lumens and alveolar arrangement, with no inflammatory cell infiltration and aggregation around the bronchi; the rats in the model group had the infiltration and aggregation of a large number of inflammatory cells around the bronchi, stenosis of bronchial lumens, wall thickening, and alveolar structural disorder; compared with the model group, the acupuncture group and the moxibustion group had lower degrees of inflammatory cell infiltration and aggregation around the bronchi, stenosis of bronchial lumens, and wall thickening, as well as regular alveolar arrangement. The model group had significantly higher protein expression of CCL1 and CCR8 and mRNA expression of STAT6 than the blank group (P<0.05), and the acupuncture group and the moxibustion group had significantly lower protein expression of CCL1 and CCR8 and mRNA expression of STAT6 (P<0.05). CONCLUSION: Acupuncture and moxibustion can intervene against airway inflammation by inhibiting the protein expression of CCL1 and CCR8 and STAT6 signal transduction in lung tissue, which may be one of the mechanisms of acupuncture and moxibustion in the treatment of asthma.
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Objective@#To analyze the dynamic changes in the expression and function of peripheral type Ⅱ innate lymphoid cell (ILC2) subpopulation and the activity of signal transducers and activators of transcription (STAT6) in children with hay fever during pollen season.@*Methods@#A total of 10 patients with hay fever, 10 patients with house dust mite (HDM)-sensitized asthma and 12 healthy controls (HC) were enrolled in this study. Changes in peripheral ILC2 and the intracellular expression of Th2-related cytokines were detected by flow cytometry during and outside the pollen season. Peripheral Lin- cell population was isolated from each group and cultured with the presence of IL-25 or IL-33 for 7 d. The concentrations of IL-5 and IL-13 in culture supernatants were measured by ELISA. Expression of phospho-STAT6 at protein level was quantified by Western blot.@*Results@#Within the pollen season, the percentage of peripheral ILC2 cells was significantly higher in children with hay fever [(23.09±7.86)%] than in children with HDM-sensitized asthma [(6.84±3.85)%, P<0.05] and healthy children[(1.69±0.87)%, P<0.05]. In the non-pollen season, the peripheral ILC2 cells in children with hay fever presented a decreasing trend [(11.30±2.45)%], but was still higher than that in HDM-sensitized asthmatics [(3.76±1.96)%, P<0.05] and HC [(1.32±0.91)%, P<0.05] at the same time point. Moreover, peripheral IL-13+ ILC2 cells in children with hay fever [(6.94±3.16)% vs(4.17±1.98)%, P<0.05] and in HDM-sensitized asthmatics [(1.89±0.70)% vs(1.44±0.55)%, P<0.05] during the pollen season were significantly higher than those in the non-pollen season. After the in vitro stimulation with IL25 or IL-33, the levels of IL-5 and IL-13 in culture supernatants were both increased in children with hay fever and HDM-sensitized asthmatics, and a synergistic action was observed when IL25 and IL-33 were used in combination. Meanwhile, the protein level of phospho-STAT4 in Lin- cells was significantly up-regulated in the hay fever group after stimulation with IL25 and IL-33.@*Conclusions@#During the pollen season, the abnormal number and function of ILC2 subpopulation in children with hay fever might be another cause of the occurrence of clinical symptoms in a short period of time or acute exacerbation.
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Objective:To study the distribution and expression of STAT6 and to examine the suggested roles of STAT6 in the pathogenesis of eosinophil infiltration in nasal polyps and to evaluate the role of STAT6 in the pathogenesis of nasal polyps.Method:All selected cases met the enrollment criteria.Thirty samples of nasal polyps were obtained from patients undergoing nasal polypectomy, and 10 samples of inferior turbinate tissues were from patients undergoing nasal septal reconstruction.STAT6 in nasal polyp tissues from 30 nasal polyposis patients and 10 samples of inferior turbinate tissues were detected with immunohistochemistry(SP) method.SPSS13.0 system was used to perform the statistical analysis.Result:The positive expression of STAT6 was significantly higher in epithelium of nasal polyps than that of the control. The number of eosinophils was significantly higher in epithelium of nasal polyps than that of the control. The difference between these two groups was statitically significant(P<0.05). STAT6 positive cell were localized on epithelium, gland cells and on inflammatory cell of nasal polyps. STAT6 expression was positively correlated with the recruitment of eosinophils in nasal polyps.Conclusion:The high expression of STAT6 protein and the suggested roles of STAT6 in the recruitment of eosinophils in nasal polyps may contribute to the initiation and progression of nasal polyps.
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OBJECTIVE: Recent molecular and genetic investigations have suggested that the current nosology for major psychiatric disorders, based on the "two-entities-principal" is not accurate with respect to clinical observations; patient groups that do not fit to the current operative diagnostic boundaries are readily identified. We aimed to perform an investigation of the signal transducer and activator of transcription 6 (STAT6) gene (located on 12q13), which has an important role in the apoptotic cascade, with patients suffering from periodic psychosis. METHODS: Genetic association study has been employed for the current work. Investigated six tag-SNPs were chosen from Hapmap database. RESULTS: Among six tag-SNPs, one marker (rs10783813), located in the STAT6 gene, showed modest association (p<0.05), although no marker or haplotype block showed association after Bonferroni's correction. CONCLUSION: Future studies will reveal the etiological role of STAT6, and of other genes of the apoptotic cascade, in major psychiatric disorders.
Subject(s)
Humans , Genetic Association Studies , Haplotypes , HapMap Project , Psychotic Disorders , STAT6 Transcription FactorABSTRACT
AIM: To study the effect of signal transducer and activator of transcription 6 (STAT6) on airway inflammation of rats with asthma. METHODS: Male Sprague-Dawley rats were randomly divided into control group and asthma group. The lung tissue was sampled from the left lung. Bronchoalveolar lavage fluid (BALF) was collected from the right lung. The concentrations of IL-4 in serum and BALF were measured by sandwich ELISA. STAT6 protein and STAT6 mRNA were observed in the epithelial cells of bronchus by the technique of immunohistochemistry and in situ hybridization. RESULTS: (1) The concentrations of IL-4 in BALF and serum of asthma group were significantly higher than those in control group (P