BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 fin...BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.AIM To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.METHODS Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8(CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.RESULTS We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine(DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.CONCLUSION DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.展开更多
OBJECTIVE To study the relationship among microsatellite instability （MSI）, frameshift mutations （FM） of the transforming growth factor β receptor Ⅱ （TGF β R Ⅱ）, methylation state of the hMLH1 promoter and h...OBJECTIVE To study the relationship among microsatellite instability （MSI）, frameshift mutations （FM） of the transforming growth factor β receptor Ⅱ （TGF β R Ⅱ）, methylation state of the hMLH1 promoter and hMLH1 protein expression level in gastric cancers, and to explore their relationship to gastric carcinogenesis. METHODS DNA was isolated from 101 gastric specimens and 5 microsatellite loci were detected. PCR, electrophoresis on denatured polyacrylamide gels and silver staining were performed to detect the MSI. The FMs of TGFβR Ⅱ were also screened with the same method. HMLH1 methylation was analyzed by methylation specific PCR （MSP） and sequencing. HMLH1 protein expression was detected using immunohistochemistry. RESULTS The incidence of MSIs was 53.7% and 0% in the cancers and normal tissues, respectively, with the frequency of MSIs being significantly higher in the gastric cancers compared to the normal gastric tissues （P〈0.05）. The frequency of hMLH1 methylation was 41.5%（17/41） in the gastric cancers and 0%（0/60） in the normal group. Decreased hMLH1 expression was observed in 94.1%（16/17） of cases exhibiting methylation. FMs of TGFβR Ⅱ were identified in 5 （62.5%） of the 8 samples with MSIH. In contrast, FMs were not found in MSI-L or microsatellite stable （MSS） cases. CONCLUSION MSIs and FMs of TGFβR Ⅱ may play an important role in gastric carcinogenesis. HMLH1 methylation is an important modification of the DNA which results in inactivation of hMLH1 and mismatch repair defects which lead to MSls and FMs of TGFβR Ⅱ.展开更多
Objective: To study the transforming growth factor β receptor Ⅱ (TGFβ-R Ⅱ) expression in experimental cryptorchidism and apoptosis in spermatogenic cells in rats. Methods: The apoptosis of spermatogenic cells was ...Objective: To study the transforming growth factor β receptor Ⅱ (TGFβ-R Ⅱ) expression in experimental cryptorchidism and apoptosis in spermatogenic cells in rats. Methods: The apoptosis of spermatogenic cells was detected by means of the terminal deoxynucleotldyl transferase mediated dUTP nick end lableling method (TUNEL) and the TGFβ-R Ⅱ expression was observed with the immunohistochemistry SABC methods. Results: There was a significant increase in the TGFβ-R Ⅱ expression in unilateral undescended testes (UUTs) compared with that in contralateral descended testes (CDTs, P<0.01). However, there was a significant and time-dependent increase in the mean apoptotic index in UUTs than in CDTs. Conclusion: TGFβ-R Ⅱ may play an important role in spermatogenic cell apoptosis.展开更多
Transforming growth factor beta (TGF β) may cause cell cycle arrest, terminal differentiation, or apoptosis in most normal epithelial cells, whereas most malignant cell lines are resistant to TGF β. Mechanisms of...Transforming growth factor beta (TGF β) may cause cell cycle arrest, terminal differentiation, or apoptosis in most normal epithelial cells, whereas most malignant cell lines are resistant to TGF β. Mechanisms of resistance to TGF β caused by modulation of cell cycle regulators and/or inactivation of components of the TGF β signaling transduction pathway such as C myc and Smad4 are not well understood. To investigate the potential association between loss of sensitivity to TGF β and expression status of transforming growth factor receptor Ⅱ (TβRⅡ), Smad4, CDC25A and C myc in 14 cell lines derived from ovarian cancer, the expression levels of these genes were detected by semi quantitative RT PCR. Normal ovarian surface tissues were used as controls. The expression of TβRⅡ was detectable in all of 14 cell lines. The expression of Smad4 was decreased in 10 cell lines and 9 cell lines overexpressed CDC25A, as compared to normal controls. CDC25A gene was overexpressed with 88 % (8/9) in tumorigenic cell lines as determined by xenografts in nude mice, and only in 20 % (1/5) of non tumorigenic cell lines ( P <0.05). C myc was not overexpressed in any of these cell lines. The loss of sensitivity to TGF β of cell lines derived from ovarian cancers may be related to a decreased expression of Smad4, which mediates TGF β induced growth inhibition, and/or an overexpression of CDC25A. This overexpression of CDC25A correlates with increased tumorigenicity of ovarian cancer cell lines. The loss of sensitivity to TGF β is not associated with a lack of TβRⅡ.展开更多
基金Supported by the Special Research Project for Capital Health Development,No.2022-2-2174the Beijing Municipal Science and Technology Commission,No.Z191100007619037.
文摘BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.AIM To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.METHODS Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8(CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.RESULTS We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine(DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.CONCLUSION DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.
文摘OBJECTIVE To study the relationship among microsatellite instability （MSI）, frameshift mutations （FM） of the transforming growth factor β receptor Ⅱ （TGF β R Ⅱ）, methylation state of the hMLH1 promoter and hMLH1 protein expression level in gastric cancers, and to explore their relationship to gastric carcinogenesis. METHODS DNA was isolated from 101 gastric specimens and 5 microsatellite loci were detected. PCR, electrophoresis on denatured polyacrylamide gels and silver staining were performed to detect the MSI. The FMs of TGFβR Ⅱ were also screened with the same method. HMLH1 methylation was analyzed by methylation specific PCR （MSP） and sequencing. HMLH1 protein expression was detected using immunohistochemistry. RESULTS The incidence of MSIs was 53.7% and 0% in the cancers and normal tissues, respectively, with the frequency of MSIs being significantly higher in the gastric cancers compared to the normal gastric tissues （P〈0.05）. The frequency of hMLH1 methylation was 41.5%（17/41） in the gastric cancers and 0%（0/60） in the normal group. Decreased hMLH1 expression was observed in 94.1%（16/17） of cases exhibiting methylation. FMs of TGFβR Ⅱ were identified in 5 （62.5%） of the 8 samples with MSIH. In contrast, FMs were not found in MSI-L or microsatellite stable （MSS） cases. CONCLUSION MSIs and FMs of TGFβR Ⅱ may play an important role in gastric carcinogenesis. HMLH1 methylation is an important modification of the DNA which results in inactivation of hMLH1 and mismatch repair defects which lead to MSls and FMs of TGFβR Ⅱ.
文摘Objective: To study the transforming growth factor β receptor Ⅱ (TGFβ-R Ⅱ) expression in experimental cryptorchidism and apoptosis in spermatogenic cells in rats. Methods: The apoptosis of spermatogenic cells was detected by means of the terminal deoxynucleotldyl transferase mediated dUTP nick end lableling method (TUNEL) and the TGFβ-R Ⅱ expression was observed with the immunohistochemistry SABC methods. Results: There was a significant increase in the TGFβ-R Ⅱ expression in unilateral undescended testes (UUTs) compared with that in contralateral descended testes (CDTs, P<0.01). However, there was a significant and time-dependent increase in the mean apoptotic index in UUTs than in CDTs. Conclusion: TGFβ-R Ⅱ may play an important role in spermatogenic cell apoptosis.
文摘Transforming growth factor beta (TGF β) may cause cell cycle arrest, terminal differentiation, or apoptosis in most normal epithelial cells, whereas most malignant cell lines are resistant to TGF β. Mechanisms of resistance to TGF β caused by modulation of cell cycle regulators and/or inactivation of components of the TGF β signaling transduction pathway such as C myc and Smad4 are not well understood. To investigate the potential association between loss of sensitivity to TGF β and expression status of transforming growth factor receptor Ⅱ (TβRⅡ), Smad4, CDC25A and C myc in 14 cell lines derived from ovarian cancer, the expression levels of these genes were detected by semi quantitative RT PCR. Normal ovarian surface tissues were used as controls. The expression of TβRⅡ was detectable in all of 14 cell lines. The expression of Smad4 was decreased in 10 cell lines and 9 cell lines overexpressed CDC25A, as compared to normal controls. CDC25A gene was overexpressed with 88 % (8/9) in tumorigenic cell lines as determined by xenografts in nude mice, and only in 20 % (1/5) of non tumorigenic cell lines ( P <0.05). C myc was not overexpressed in any of these cell lines. The loss of sensitivity to TGF β of cell lines derived from ovarian cancers may be related to a decreased expression of Smad4, which mediates TGF β induced growth inhibition, and/or an overexpression of CDC25A. This overexpression of CDC25A correlates with increased tumorigenicity of ovarian cancer cell lines. The loss of sensitivity to TGF β is not associated with a lack of TβRⅡ.
