To investigate whether microRNA (miR)-34a mediates oxaliplatin (OXA) resistance of colorectal cancer (CRC) cells by inhibiting macroautophagy via the transforming growth factor (TGF)-β/Smad4 pathway.METHODSmiR-34a ex...To investigate whether microRNA (miR)-34a mediates oxaliplatin (OXA) resistance of colorectal cancer (CRC) cells by inhibiting macroautophagy via the transforming growth factor (TGF)-β/Smad4 pathway.METHODSmiR-34a expression levels were detected in CRC tissues and CRC cell lines by quantitative real-time polymerase chain reaction. Computational search, functional luciferase assay and western blotting were used to demonstrate the downstream target of miR-34a in CRC cells. Cell viability was measured with Cell Counting Kit-8. Apoptosis and macroautophagy of CRC cells were analyzed by flow cytometry and transmission electron microscopy, and expression of beclin I and LC3-II was detected by western blotting.RESULTSExpression of miR-34a was significantly reduced while expression of TGF-β and Smad4 was increased in CRC patients treated with OXA-based chemotherapy. OXA treatment also resulted in decreased miR-34a levels and increased TGF-β and Smad4 levels in both parental cells and the OXA-resistant CRC cells. Activation of macroautophagy contributed to OXA resistance in CRC cells. Expression levels of Smad4 and miR-34a in CRC patients had a significant inverse correlation and overexpressing miR-34a inhibited macroautophagy activation by directly targeting Smad4 through the TGF-β/Smad4 pathway. OXA-induced downregulation of miR-34a and increased drug resistance by activating macroautophagy in CRC cells.CONCLUSIONmiR-34a mediates OXA resistance of CRC by inhibiting macroautophagy via the TGF-β/Smad4 pathway.展开更多
AIM: To investigate the antifibrotic effects of bone morphogenetic protein-7 (BMP-7) on Schistosoma japonicum (S. japonicum )-induced hepatic fibrosis in BALB/C mice. METHODS: Sixty BALB/C mice were randomly divided i...AIM: To investigate the antifibrotic effects of bone morphogenetic protein-7 (BMP-7) on Schistosoma japonicum (S. japonicum )-induced hepatic fibrosis in BALB/C mice. METHODS: Sixty BALB/C mice were randomly divided into three groups, including a control group (group A, n = 20), model group (group B, n = 20) and BMP-7 treated group (group C, n = 20). The mice in group B and group C were abdominally infected with S. japonicum cercariae to induce a schistosomal hepatic fibrosis model. The mice in group C were administered human recombinant BMP-7. Liver samples were extracted from mice sacrificed at 9 and 15 wk after modeling. Hepatic histopathological changes were assessed using Masson's staining. Transforming growth factor-beta 1 (TGF-β1), alpha-smooth muscle actin (α-SMA), phosphorylated Smad2/3 (pSmad2/3) and Smad7 protein levels and localization were measured by Western blotting and immunohistochemistry, respectively, and their mRNA expressions were detected by reverse transcriptionpolymerase chain reaction (RT-PCR). RESULTS: The schistosomal hepatic fibrosis mouse model was successfully established, as the livers of mice in group B and group C showed varying degrees of typical schistosomal hepatopathologic changes such as egg granuloma and collagen deposition. The degree of collagen deposition in group C was higher than that in group A (week 9: 22.95±6.66vs 2.02±0.76; week 15: 12.84±4.36 vs 1.74±0.80; P<0.05), but significantly lower than that in group B (week 9: 22.95±6.66 vs 34.43±6.96; week 15: 12.84±4.36 vs 18.90±5.07;P<0.05) at both time points. According to immunohistochemistry data, the expressions of α-SMA, TGF-β1 and pSmad2/3 protein in group C were higher than those in group A (α-SMA: week 9: 21.24±5.73 vs 0.33±0.20; week 15: 12.42±4.88 vs 0.34±0.27; TGF-β1: week 9: 37.00±13.74 vs 3.73±2.14; week 15: 16.71±9.80 vs 3.08±2.35; pSmad2/3: week 9: 12.92±4.81 vs 0.83±0.48; week 15: 7.87±4.09 vs 0.90±0.45; P<0.05), but significantly lower than those in group B (α-SMA: week 9: 21.24±5.73 vs 34.39±5.74; week 15: 12.42±4.88 vs 25.90±7.01; TGF-β1: week 9: 37.00±13.74 vs 55.66±14.88; week 15: 16.71±9.80 vs 37.10±12.51; pSmad2/3: week 9: 12.92±4.81 vs 19.41±6.87; week 15: 7.87±4.09vs 13.00±4.98;P<0.05) at both time points; the expression of Smad7 protein in group B was higher than that in group A and group C at week 9 (8.46±3.95 vs 1.00±0.40 and 8.46±3.95 vs 0.77±0.42; P<0.05), while there were no differences in Smad7 expression between the three groups at week 15 (1.09±0.38 vs 0.97±0.42 vs 0.89±0.39; P>0.05). Although minor discrepancies were observed, the results of RT-PCR and Western blotting were mainly consistentwith the immunohistochemical results. CONCLUSION: Exogenous BMP-7 significantly decreased the degree of hepatic fibrosis in both the acute and chronic stages of hepato-schistosomiasis, and the regulatory mechanism may involve the TGF-β/Smad signaling pathway.展开更多
Summary: The activation of hepatic stellate cells (HSCs) and their transformation to myofibroblasts are the key steps in the pathological progress of liver fibrosis. The transforming growth factor-J3 (TGFβ)/Smad...Summary: The activation of hepatic stellate cells (HSCs) and their transformation to myofibroblasts are the key steps in the pathological progress of liver fibrosis. The transforming growth factor-J3 (TGFβ)/Smad pathway is involved in the proliferation and collagen synthesis of HSCs. This study aimed to examine the effect of the protease inhibitor MG132 on the signaling pathway of TGFβ/Smad in HSC-T6 cells and seek a novel therapeutic approach for liver fibrosis. The HSC-T6 cells were treated with MG132 at different concentrations (0-10 maol/L). Cell proliferation was detected by MTT method. The mRNA and protein expression levels of TGFI31, Smad3 and Smad7 were determined in HSC-T6 cells by real-time PCR and Western blotting, respectively, after treatment with MG132 at different con- centrations (1, 2, 3 μtmol/L) or RPMI1640 alone (serving as control). The results showed that MG132 could inhibit the proliferation of HSC-T6 cells in a dose-dependent manner, and the IC50 of MG132 was 6.84 μmol/L. After treatment with MG132 at 1, 2 or 3 nol/L for 24 h, the mRNA expression levels of TGF-β1 and Smad3 were significantly decreased (P〈0.05), but the Smad7 mRNA expression had no significant change (P〉0.05). There was also a significant decrease in the protein expression level of TGF-β1 and Smad3 (P〈0.05). However, the expression of Smad7 protein was substantially increased when compared with the control group (P〈0.05). It was concluded that the inhibition of TGFi/Smad pathway in HSC-T6 cells by MG132 can reduce the production of profibrosis factors (TGFI31, Smad3) and promote the expression of anti-fibrosis factor (Smad7), suggesting that MG132 may become a po- tential therapeutic alternative for liver fibrosis.展开更多
激素性股骨头坏死(steroid-induced osteonecrosis of the femoral head,SIONFH)是由于糖皮质激素使用不当或过度而引起的髋关节疾病,发病机制尚未统一,临床疗效亦不佳。当前,没有效果明确的药物可以延缓疾病进程,而中医药治疗SIONFH在...激素性股骨头坏死(steroid-induced osteonecrosis of the femoral head,SIONFH)是由于糖皮质激素使用不当或过度而引起的髋关节疾病,发病机制尚未统一,临床疗效亦不佳。当前,没有效果明确的药物可以延缓疾病进程,而中医药治疗SIONFH在临床上取得一定疗效。即便如此,仍未能完整的从分子生物及细胞生物学角度阐明中药治疗SIONFH的作用机制。转化生长因子-β(TGF-β)/骨形态发生蛋白(BMP)/Smad信号通路的转导是防治SIONFH的研究热点之一,故该文阐明了该信号通路的转导机制以及与SIONFH的联系,检索了基于该通路治疗SIONFH的全部中药及复方并阐述其影响机制。基于中医对SIONFH的认识,现临床上使用补肝肾强筋骨以及活血祛瘀通络类的方药治疗SIONFH,且具有良好的疗效。中药通过调控该通路,可刺激骨髓间充质干细胞成骨分化,降低破骨细胞含量,减少脂肪生成,改善微循环,抗氧化损伤,促进股骨头内血管新生,从而促进股骨头损伤的修复。现基于TGF-β/BMP/Smad信号通路对中医药治疗SIONFH的研究进展做一综述,期许为中医药治疗SIONFH提供理论依据及参考。展开更多
基金Supported by Science Foundation of Education Department of Heilongjiang Province,China,no.12541430
文摘To investigate whether microRNA (miR)-34a mediates oxaliplatin (OXA) resistance of colorectal cancer (CRC) cells by inhibiting macroautophagy via the transforming growth factor (TGF)-β/Smad4 pathway.METHODSmiR-34a expression levels were detected in CRC tissues and CRC cell lines by quantitative real-time polymerase chain reaction. Computational search, functional luciferase assay and western blotting were used to demonstrate the downstream target of miR-34a in CRC cells. Cell viability was measured with Cell Counting Kit-8. Apoptosis and macroautophagy of CRC cells were analyzed by flow cytometry and transmission electron microscopy, and expression of beclin I and LC3-II was detected by western blotting.RESULTSExpression of miR-34a was significantly reduced while expression of TGF-β and Smad4 was increased in CRC patients treated with OXA-based chemotherapy. OXA treatment also resulted in decreased miR-34a levels and increased TGF-β and Smad4 levels in both parental cells and the OXA-resistant CRC cells. Activation of macroautophagy contributed to OXA resistance in CRC cells. Expression levels of Smad4 and miR-34a in CRC patients had a significant inverse correlation and overexpressing miR-34a inhibited macroautophagy activation by directly targeting Smad4 through the TGF-β/Smad4 pathway. OXA-induced downregulation of miR-34a and increased drug resistance by activating macroautophagy in CRC cells.CONCLUSIONmiR-34a mediates OXA resistance of CRC by inhibiting macroautophagy via the TGF-β/Smad4 pathway.
文摘AIM: To investigate the antifibrotic effects of bone morphogenetic protein-7 (BMP-7) on Schistosoma japonicum (S. japonicum )-induced hepatic fibrosis in BALB/C mice. METHODS: Sixty BALB/C mice were randomly divided into three groups, including a control group (group A, n = 20), model group (group B, n = 20) and BMP-7 treated group (group C, n = 20). The mice in group B and group C were abdominally infected with S. japonicum cercariae to induce a schistosomal hepatic fibrosis model. The mice in group C were administered human recombinant BMP-7. Liver samples were extracted from mice sacrificed at 9 and 15 wk after modeling. Hepatic histopathological changes were assessed using Masson's staining. Transforming growth factor-beta 1 (TGF-β1), alpha-smooth muscle actin (α-SMA), phosphorylated Smad2/3 (pSmad2/3) and Smad7 protein levels and localization were measured by Western blotting and immunohistochemistry, respectively, and their mRNA expressions were detected by reverse transcriptionpolymerase chain reaction (RT-PCR). RESULTS: The schistosomal hepatic fibrosis mouse model was successfully established, as the livers of mice in group B and group C showed varying degrees of typical schistosomal hepatopathologic changes such as egg granuloma and collagen deposition. The degree of collagen deposition in group C was higher than that in group A (week 9: 22.95±6.66vs 2.02±0.76; week 15: 12.84±4.36 vs 1.74±0.80; P<0.05), but significantly lower than that in group B (week 9: 22.95±6.66 vs 34.43±6.96; week 15: 12.84±4.36 vs 18.90±5.07;P<0.05) at both time points. According to immunohistochemistry data, the expressions of α-SMA, TGF-β1 and pSmad2/3 protein in group C were higher than those in group A (α-SMA: week 9: 21.24±5.73 vs 0.33±0.20; week 15: 12.42±4.88 vs 0.34±0.27; TGF-β1: week 9: 37.00±13.74 vs 3.73±2.14; week 15: 16.71±9.80 vs 3.08±2.35; pSmad2/3: week 9: 12.92±4.81 vs 0.83±0.48; week 15: 7.87±4.09 vs 0.90±0.45; P<0.05), but significantly lower than those in group B (α-SMA: week 9: 21.24±5.73 vs 34.39±5.74; week 15: 12.42±4.88 vs 25.90±7.01; TGF-β1: week 9: 37.00±13.74 vs 55.66±14.88; week 15: 16.71±9.80 vs 37.10±12.51; pSmad2/3: week 9: 12.92±4.81 vs 19.41±6.87; week 15: 7.87±4.09vs 13.00±4.98;P<0.05) at both time points; the expression of Smad7 protein in group B was higher than that in group A and group C at week 9 (8.46±3.95 vs 1.00±0.40 and 8.46±3.95 vs 0.77±0.42; P<0.05), while there were no differences in Smad7 expression between the three groups at week 15 (1.09±0.38 vs 0.97±0.42 vs 0.89±0.39; P>0.05). Although minor discrepancies were observed, the results of RT-PCR and Western blotting were mainly consistentwith the immunohistochemical results. CONCLUSION: Exogenous BMP-7 significantly decreased the degree of hepatic fibrosis in both the acute and chronic stages of hepato-schistosomiasis, and the regulatory mechanism may involve the TGF-β/Smad signaling pathway.
基金supported by a grant from the Natural Science Foundation of Hubei Province(No.2010CHB00401)
文摘Summary: The activation of hepatic stellate cells (HSCs) and their transformation to myofibroblasts are the key steps in the pathological progress of liver fibrosis. The transforming growth factor-J3 (TGFβ)/Smad pathway is involved in the proliferation and collagen synthesis of HSCs. This study aimed to examine the effect of the protease inhibitor MG132 on the signaling pathway of TGFβ/Smad in HSC-T6 cells and seek a novel therapeutic approach for liver fibrosis. The HSC-T6 cells were treated with MG132 at different concentrations (0-10 maol/L). Cell proliferation was detected by MTT method. The mRNA and protein expression levels of TGFI31, Smad3 and Smad7 were determined in HSC-T6 cells by real-time PCR and Western blotting, respectively, after treatment with MG132 at different con- centrations (1, 2, 3 μtmol/L) or RPMI1640 alone (serving as control). The results showed that MG132 could inhibit the proliferation of HSC-T6 cells in a dose-dependent manner, and the IC50 of MG132 was 6.84 μmol/L. After treatment with MG132 at 1, 2 or 3 nol/L for 24 h, the mRNA expression levels of TGF-β1 and Smad3 were significantly decreased (P〈0.05), but the Smad7 mRNA expression had no significant change (P〉0.05). There was also a significant decrease in the protein expression level of TGF-β1 and Smad3 (P〈0.05). However, the expression of Smad7 protein was substantially increased when compared with the control group (P〈0.05). It was concluded that the inhibition of TGFi/Smad pathway in HSC-T6 cells by MG132 can reduce the production of profibrosis factors (TGFI31, Smad3) and promote the expression of anti-fibrosis factor (Smad7), suggesting that MG132 may become a po- tential therapeutic alternative for liver fibrosis.
文摘激素性股骨头坏死(steroid-induced osteonecrosis of the femoral head,SIONFH)是由于糖皮质激素使用不当或过度而引起的髋关节疾病,发病机制尚未统一,临床疗效亦不佳。当前,没有效果明确的药物可以延缓疾病进程,而中医药治疗SIONFH在临床上取得一定疗效。即便如此,仍未能完整的从分子生物及细胞生物学角度阐明中药治疗SIONFH的作用机制。转化生长因子-β(TGF-β)/骨形态发生蛋白(BMP)/Smad信号通路的转导是防治SIONFH的研究热点之一,故该文阐明了该信号通路的转导机制以及与SIONFH的联系,检索了基于该通路治疗SIONFH的全部中药及复方并阐述其影响机制。基于中医对SIONFH的认识,现临床上使用补肝肾强筋骨以及活血祛瘀通络类的方药治疗SIONFH,且具有良好的疗效。中药通过调控该通路,可刺激骨髓间充质干细胞成骨分化,降低破骨细胞含量,减少脂肪生成,改善微循环,抗氧化损伤,促进股骨头内血管新生,从而促进股骨头损伤的修复。现基于TGF-β/BMP/Smad信号通路对中医药治疗SIONFH的研究进展做一综述,期许为中医药治疗SIONFH提供理论依据及参考。