Melatonin has been reported to inhibit hepatic fibrosis and the mechanism may be correlated to its anti-oxidant effect. Nevertheless, the mechanism is not completely identified. This study was conducted to investigate...Melatonin has been reported to inhibit hepatic fibrosis and the mechanism may be correlated to its anti-oxidant effect. Nevertheless, the mechanism is not completely identified. This study was conducted to investigate the effects of melatonin on TGF-β1/Smad signaling pathway in liver fibrosis in rats. The liver fibrosis model was made by the subcutaneous injection of CC14. The liver pathology changes were detected using hematoxylin and eosin （H＆E） staining and Van Gieson （VG） staining. Serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） activities were measured with an autoanalyzer. Glutathione peroxidase （GPx） activities and levels of malondialdehyde （MDA） and hydroxyproline （Hyp） in liver were evaluated by spectrophotometry. Expression levels of TGF-β1, Smad2/3, phosphorylated Smad2/3 （p-Smad2/3） and Smad7 in liver were detected by immunohistochemistry and Western blot analysis. Results showed that melatonin suppressed CC14-induced liver fibrosis, along with an improvement in histological changes, significant decreases in pathologic grading sores and obvious decreases in Hyp levels in liver. Melatonin improved liver function indicated by decreased serum ALT and AST activities. In addition, melatonin exerted its anti-oxidant effects, as supported by decreased MDA levels and increased GPx activities in liver. Furthermore, melatonin inhibited TGF-β1/Smad pathway, as evidenced by decreased TGF-β1, Smad2/3 and p-Smad2/3 expression and increased Smad7 expression in liver. In conclusion, melatonin may suppress CCl4-induced hepatic fibrosis in rats via inhibiting TGF-β1/Smad pathway. It is possible for melatonin to be a potential reagent to treat and cure liver fibrosis.展开更多
Background: To explore the effects of electroacupuncture on cardiac function and myocardial fibrosis in rat models of heart failure, and to elucidate the underlying mechanism of electroacupuncture in heart failure tre...Background: To explore the effects of electroacupuncture on cardiac function and myocardial fibrosis in rat models of heart failure, and to elucidate the underlying mechanism of electroacupuncture in heart failure treatment. Methods: Healthy male Sprague-Dawley rats were allocated into three groups: Sham group, Model group, and electroacupuncture (Model + EA) group, with each group comprising 8 rats. The model underwent a procedure involving the ligation of the left anterior descending coronary artery to induce a model of heart failure. The Model + EA group was used for 7 consecutive days for electroacupuncture of bilateral Shenmen (HT7) and Tongli (HT5), once a day for 30 min each time. Left ventricular parameters in rats were assessed using a small-animal ultrasound machine to analyze changes in left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction, and left ventricular fractional shortening. Serum interleukin-1β (IL-1β), cardiac troponin (cTn), and N-terminal brain natriuretic peptide precursor levels were measured using ELISA. Histopathological changes in rat myocardium were observed through HE staining, while collagen deposition in rat myocardial tissue was assessed using the Masson staining method. Picro sirius red staining, immunohistochemical staining, and RT-qPCR were utilized to distinguish between the various types of collagen deposition. The expression level of TGF-β1 and SMAD2/3/4/7 mRNA in rat myocardial tissues was determined using RT-qPCR. Additionally, western blot analysis was conducted to assess the protein expression levels of TGF-β1, SMAD3/7, and p-SMAD3 in rat myocardial tissues. Results: Compared with the Sham group, the left ventricular ejection fraction and left ventricular fractional shortening values of the Model group were significantly decreased (P < 0.01);the left ventricular end-diastolic volume and left ventricular end-systolic volume values were remarkably increased (P < 0.01);serum N-terminal brain natriuretic peptide precursor content was increased (P < 0.01);serum IL-1β and cTn levels were increased (P < 0.01);myocardial collagen volume fraction were increased (P < 0.01);and those of the expression of TGF-β1 and SMAD2/3/4 mRNA was increased (P < 0.01);the expression of SMAD7 mRNA was decreased (P < 0.01);the protein expression levels of TGF-β1, SMAD3, and p-Smad3 were increased (P < 0.01);the protein expression level of SMAD7 was decreased (P < 0.01) in the Model group. Compared to the Model group, the expression levels of the proteins TGF-β1, SMAD3, and p-Smad3 in myocardial tissue were found to be decreased (P < 0.01), and the expression level of the protein SMAD7 was found to be increased (P < 0.01) in the Model + EA group;the collagen volume fraction and deposition of type Ⅰ /Ⅲ collagen were decreased (P < 0.01) in the Model + EA group. Conclusion: Electroacupuncture alleviates myocardial fibrosis in rats with heart failure, and this effect is likely due to attributed to the modulation of the TGF-β1/Smads signaling pathway, which helps reduce collagen deposition in the extracellular matrix.展开更多
MicroRNAs(miRNAs)have been demonstrated to control chicken skeletal muscle growth,however,the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown.Here,our study identified the two...MicroRNAs(miRNAs)have been demonstrated to control chicken skeletal muscle growth,however,the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown.Here,our study identified the two chicken(Gallus gallus;Gga)miR-181-5p family members widely expressed in various tissues,specifically miR-181a-5p and miR-181b-5p.Besides,the breast muscles of fast-growing broilers expressed higher levels of miR-181a-5p and miR-181b-5p than those of slow-growing layers.Functionally,miR-181a-5p and miR-181b-5p both promote the expression level of myogenic factors including myogenin(MyoG),myogenic differentiation 1(MyoD1),and myosin heavy chain(MyHC),meanwhile accelerating the myotube formation of skeletal muscle satellite cells(SMSCs).Mechanistically,miR-181a-5p and miR-181b-5p directly bind to the 3′untranslated region(UTR)of the transforming growth factor beta receptor 1(TGFBR1)mRNA,further reducing the expression of TGFBR1.TGFBR1 is a key Transforming growth factor beta(TGF-β)signaling transduction receptor and had a negative function in muscle cell differentiation.Furthermore,knockdown of TGFBR1 facilitated the expression of chicken myogenic factors,boosted myotube formation,and decreased the SMAD family member 2/3(SMAD2/3)phosphorylation in chicken SMSCs.SMAD2/3 are downstream of TGF-βsignaling,and miR-181a-5p and miR-181b-5p could reduce the expression of TGFBR1 to further diminish the SMAD2/3 phosphorylation.Our findings revealed that the miR-181-5p family targets TGFBR1 to break the TGF-βsignaling transduction,which resulted in promoting chicken skeletal muscle development.展开更多
基金This study was supported by the Natural Science Research Project of Colleges and Universities in Anhui Province （No. KJ2013A155） and the National Natural Science Foundation of China （No. 81370529）.
文摘Melatonin has been reported to inhibit hepatic fibrosis and the mechanism may be correlated to its anti-oxidant effect. Nevertheless, the mechanism is not completely identified. This study was conducted to investigate the effects of melatonin on TGF-β1/Smad signaling pathway in liver fibrosis in rats. The liver fibrosis model was made by the subcutaneous injection of CC14. The liver pathology changes were detected using hematoxylin and eosin （H＆E） staining and Van Gieson （VG） staining. Serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） activities were measured with an autoanalyzer. Glutathione peroxidase （GPx） activities and levels of malondialdehyde （MDA） and hydroxyproline （Hyp） in liver were evaluated by spectrophotometry. Expression levels of TGF-β1, Smad2/3, phosphorylated Smad2/3 （p-Smad2/3） and Smad7 in liver were detected by immunohistochemistry and Western blot analysis. Results showed that melatonin suppressed CC14-induced liver fibrosis, along with an improvement in histological changes, significant decreases in pathologic grading sores and obvious decreases in Hyp levels in liver. Melatonin improved liver function indicated by decreased serum ALT and AST activities. In addition, melatonin exerted its anti-oxidant effects, as supported by decreased MDA levels and increased GPx activities in liver. Furthermore, melatonin inhibited TGF-β1/Smad pathway, as evidenced by decreased TGF-β1, Smad2/3 and p-Smad2/3 expression and increased Smad7 expression in liver. In conclusion, melatonin may suppress CCl4-induced hepatic fibrosis in rats via inhibiting TGF-β1/Smad pathway. It is possible for melatonin to be a potential reagent to treat and cure liver fibrosis.
基金the China’s National Key Research and Development Program Projects(No.2022YFC3500500 and No.2022YFC3500502).
文摘Background: To explore the effects of electroacupuncture on cardiac function and myocardial fibrosis in rat models of heart failure, and to elucidate the underlying mechanism of electroacupuncture in heart failure treatment. Methods: Healthy male Sprague-Dawley rats were allocated into three groups: Sham group, Model group, and electroacupuncture (Model + EA) group, with each group comprising 8 rats. The model underwent a procedure involving the ligation of the left anterior descending coronary artery to induce a model of heart failure. The Model + EA group was used for 7 consecutive days for electroacupuncture of bilateral Shenmen (HT7) and Tongli (HT5), once a day for 30 min each time. Left ventricular parameters in rats were assessed using a small-animal ultrasound machine to analyze changes in left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction, and left ventricular fractional shortening. Serum interleukin-1β (IL-1β), cardiac troponin (cTn), and N-terminal brain natriuretic peptide precursor levels were measured using ELISA. Histopathological changes in rat myocardium were observed through HE staining, while collagen deposition in rat myocardial tissue was assessed using the Masson staining method. Picro sirius red staining, immunohistochemical staining, and RT-qPCR were utilized to distinguish between the various types of collagen deposition. The expression level of TGF-β1 and SMAD2/3/4/7 mRNA in rat myocardial tissues was determined using RT-qPCR. Additionally, western blot analysis was conducted to assess the protein expression levels of TGF-β1, SMAD3/7, and p-SMAD3 in rat myocardial tissues. Results: Compared with the Sham group, the left ventricular ejection fraction and left ventricular fractional shortening values of the Model group were significantly decreased (P < 0.01);the left ventricular end-diastolic volume and left ventricular end-systolic volume values were remarkably increased (P < 0.01);serum N-terminal brain natriuretic peptide precursor content was increased (P < 0.01);serum IL-1β and cTn levels were increased (P < 0.01);myocardial collagen volume fraction were increased (P < 0.01);and those of the expression of TGF-β1 and SMAD2/3/4 mRNA was increased (P < 0.01);the expression of SMAD7 mRNA was decreased (P < 0.01);the protein expression levels of TGF-β1, SMAD3, and p-Smad3 were increased (P < 0.01);the protein expression level of SMAD7 was decreased (P < 0.01) in the Model group. Compared to the Model group, the expression levels of the proteins TGF-β1, SMAD3, and p-Smad3 in myocardial tissue were found to be decreased (P < 0.01), and the expression level of the protein SMAD7 was found to be increased (P < 0.01) in the Model + EA group;the collagen volume fraction and deposition of type Ⅰ /Ⅲ collagen were decreased (P < 0.01) in the Model + EA group. Conclusion: Electroacupuncture alleviates myocardial fibrosis in rats with heart failure, and this effect is likely due to attributed to the modulation of the TGF-β1/Smads signaling pathway, which helps reduce collagen deposition in the extracellular matrix.
基金supported by the National Key Research and Development Program of China(2022YFF10002020)Sichuan Science and Technology Program,China(2021YFYZ0007 and 2021YFYZ0031).
文摘MicroRNAs(miRNAs)have been demonstrated to control chicken skeletal muscle growth,however,the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown.Here,our study identified the two chicken(Gallus gallus;Gga)miR-181-5p family members widely expressed in various tissues,specifically miR-181a-5p and miR-181b-5p.Besides,the breast muscles of fast-growing broilers expressed higher levels of miR-181a-5p and miR-181b-5p than those of slow-growing layers.Functionally,miR-181a-5p and miR-181b-5p both promote the expression level of myogenic factors including myogenin(MyoG),myogenic differentiation 1(MyoD1),and myosin heavy chain(MyHC),meanwhile accelerating the myotube formation of skeletal muscle satellite cells(SMSCs).Mechanistically,miR-181a-5p and miR-181b-5p directly bind to the 3′untranslated region(UTR)of the transforming growth factor beta receptor 1(TGFBR1)mRNA,further reducing the expression of TGFBR1.TGFBR1 is a key Transforming growth factor beta(TGF-β)signaling transduction receptor and had a negative function in muscle cell differentiation.Furthermore,knockdown of TGFBR1 facilitated the expression of chicken myogenic factors,boosted myotube formation,and decreased the SMAD family member 2/3(SMAD2/3)phosphorylation in chicken SMSCs.SMAD2/3 are downstream of TGF-βsignaling,and miR-181a-5p and miR-181b-5p could reduce the expression of TGFBR1 to further diminish the SMAD2/3 phosphorylation.Our findings revealed that the miR-181-5p family targets TGFBR1 to break the TGF-βsignaling transduction,which resulted in promoting chicken skeletal muscle development.
