HIV-1 matrix protein (MA) is a multifunctional structural protein localized on N terminus of Gag precursor p55. MA participates in HIV-1 assembly as membranotropic part of Gag precursor as well as an individual protei...HIV-1 matrix protein (MA) is a multifunctional structural protein localized on N terminus of Gag precursor p55. MA participates in HIV-1 assembly as membranotropic part of Gag precursor as well as an individual protein spliced from Gag early in infection. MA is found in the nuclei of infected cells and in plasma membrane, the site of virus assembly, in association with viral genome RNA. MA mutated variant M4 which contains two changed amino acids in N-terminal regions is also associated with viral RNA, but it is localized in the nuclear and cytoskeleton fractions but not in the plasma membrane suggesting that the mutant is deprived of membranotropic signal and “sticks” in the nuclei an d cytoskeleton, its previous location sites. These data allow suggesting that MA involved into transmission of viral RNA is transported to plasma membrane by cytoskeleton.展开更多
Deletion or mutation of dentin matrix protein 1 （DMP1） leads to hypophosphatemic rickets and defects within the dentin. However, it is largely unknown if this pathological change is a direct role of DMP1 or an indir...Deletion or mutation of dentin matrix protein 1 （DMP1） leads to hypophosphatemic rickets and defects within the dentin. However, it is largely unknown if this pathological change is a direct role of DMP1 or an indirect role of phosphate （Pi） or both. It has also been previously shown that Klotho-deficient mice, which displayed a high Pi level due to a failure of Pi excretion, causes mild defects in the dentinal structure. This study was to address the distinct roles of DMP1 and Pi homeostasis in cell differentiation, apoptosis and mineralization of dentin and enamel. Our working hypothesis was that a stable Pi homeostasis is critical for postnatal tooth formation, and that DMP1 has an antiapoptotic role in both amelogenesis and dentinogenesis. To test this hypothesis, Dmpl-null （Dmpl-/-）, Klotho-deficient （kl/kl）, Dmpl/Klotho-double-deficient （Dmpl-/-/kl/kl） and wild-type （WT） mice were killed at the age of 6 weeks. Combinations of X-ray, microcomputed tomography （I^CT）, scanning electron microscopy （SEM）, histology, apoptosis and immunohistochemical methods were used for characterization of dentin, enamel and pulp structures in these mutant mice. Our results showed that Dmpl-/- （a low Pi level） or kl/kl（a high Pi level） mice displayed mild dentin defects such as thin dentin and a reduction of dentin tubules. Neither deficient mouse line exhibited any apparent changes in enamel or pulp structure. However, the double-deficient mice （a high Pi level） displayed severe defects in dentin and enamel structures, including loss of dentinal tubules and enamel prisms, as well as unexpected ectopic ossification within the pulp root canal. TUNEL assay showed a sharp increase in apoptotic cells in ameloblasts and odontoblasts. Based on the above findings, we conclude that DMP1 has a protective role for odontoblasts and ameloblasts in a pro-apoptotic environment （a high Pi level）.展开更多
BACKGROUND Osteoporosis is a systemic bone disease characterized by decreased bone mass,impaired bone mass,and reduced bone strength that leads to increased bone fragility and fracture.Type 2 diabetes mellitus(T2DM)co...BACKGROUND Osteoporosis is a systemic bone disease characterized by decreased bone mass,impaired bone mass,and reduced bone strength that leads to increased bone fragility and fracture.Type 2 diabetes mellitus(T2DM)complicated with osteoporosis is a common systemic metabolic bone disease,and reduced bone mass and bone strength are considered the main clinical features;however,the pathogenesis of this disease has not been fully clarified.Its occurrence is considered related to sex,age,and genetic factors.There are many risk factors for diabetes complicated with osteoporosis.Therefore,exploring these risk factors will help prevent it.AIM To investigate the relationships among serum glucagon-like peptide-1(GLP-1)levels,matrix Gla protein(MGP)levels,and diabetes with osteoporosis.METHODS Sixty patients with T2DM complicated with osteoporosis confirmed by the endocrinology department of our hospital were selected as the case group.Sixty T2DM patients with bone loss were selected as the control group.Sixty healthy participants were selected as the healthy group.The general data,bone mineral density index,and bone metabolic markers of the three groups were compared.The relationships among GLP-1 levels,MGP levels,and the bone mineral density index of the case group were analyzed using linear correlation analysis and a logistic regression model.RESULTS Differences in sex,smoking,and drinking among the case group,control group,and healthy group were not statistically significant(P>0.05).The mean age of the case group was older than those of the control and healthy groups(P<0.05).The body mass index,fasting plasma glucose level,HbA1c level,hypertension rate,and coronary heart disease rate of the case and control groups were higher than those of the healthy group(P<0.05).The serum GLP-1 and MGP levels of the case group were lower than those of the control and healthy groups;these differences were statistically significant(P<0.05).The serum GLP-1 and MGP levels of the control group were lower than those of the healthy group;these differences were statistically significant(P<0.05).The serum GLP-1 and MGP levels of the case group were significantly positively correlated with the bone mineral density values of the hip and lumbar spine(P<0.05).The results of the logistic regression model showed that age and duration of diabetes were independent risk factors for osteoporosis in diabetic patients(P<0.05)and that increased GLP-1 and MGP values were protective factors against osteoporosis in diabetic patients(P<0.05).CONCLUSION Serum GLP-1 and MGP levels of diabetic patients with osteoporosis were significantly decreased and positively correlated with bone mineral density and were independent risk factors for osteoporosis in diabetic patients.展开更多
Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-N...Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.展开更多
目的观察腺苷预处理对大鼠脑缺血再灌注后基质金属蛋白酶9(MMP-9)和闭锁连接蛋白1(ZO-1)表达变化的影响。方法108只健康雄性SD大鼠随机分为对照组、模型组、腺苷组(n=36)。造模前腺苷组腹腔注射腺苷注射液,对照组和模型组大鼠在相同时...目的观察腺苷预处理对大鼠脑缺血再灌注后基质金属蛋白酶9(MMP-9)和闭锁连接蛋白1(ZO-1)表达变化的影响。方法108只健康雄性SD大鼠随机分为对照组、模型组、腺苷组(n=36)。造模前腺苷组腹腔注射腺苷注射液,对照组和模型组大鼠在相同时间点腹腔注射2 ml生理盐水。采用改良的线栓法栓塞右侧大脑中动脉阻断血流2 h后,将线拔出形成再灌注。再灌注24 h后,伊文思蓝(EB)渗透法测定血脑屏障通透性,检测MMP-9和ZO-1表达。结果模型组和腺苷组EB,脑含水量,MMP-9明显高于对照组,ZO-1明显低于对照组(P<0.01);模型组和腺苷组MMP-9/β肌动蛋白(β-actin)表达明显高于对照组(0.563±0.054和0.377±0.080 vs 0.242±0.021,P<0.01),ZO-1/β-actin表达明显低于对照组(0.186±0.042和0.393±0.075 vs 0.671±0.065,P<0.01)。腺苷组MMP-9/β-actin表达低于模型组,ZO-1/β-actin表达明显高于模型组(P<0.01)。结论腺苷预处理可以通过抑制MMP-9表达,增加ZO-1表达,改善血脑屏障完整性,减轻脑水肿与脑缺血再灌注后的神经损伤。展开更多
Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue ...Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue inhibitors of metalloproteinases(TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix(ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis. Methods: Hepatic fibrosis was induced by thioacetamide(TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog(Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin( α-SMA), transforming growth factor β 1(TGF β1), collagen I, MMPs/TIMPs, Sonic Hedgehog(Shh), and glioblastoma family transcription factors(Gli1) were investigated by immunohistochemical staining and Western blotting analysis. Results: We found that hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance. Conclusions: Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGF β1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.展开更多
BACKGROUND: We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGF beta 1) is known as the stron...BACKGROUND: We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGF beta 1) is known as the strongest effector of liver fibrosis. Therefore, we aimed to investigate the detailed interaction between IGFBPrP1 and TGF beta 1 in primary hepatic stellate cells (HSCs). METHODS: We overexpressed TGF beta 1 or IGFBPrP1 and inhibited TGF beta 1 expression in primary HSCs for 6, 12, 24, 48, 72, and 96 hours to investigate their interaction and observe the accompanying expressions of a-smooth muscle actin (alpha-SMA), collagen I, fibronectin, and phosphorylated-mothers against decapentaplegic homolog 2/3 (p-Smad2/3). RESULTS: We found that the adenovirus vector encoding the TGF beta 1 gene (AdTGF beta 1) induced IGFBPrP1 expression while that of alpha-SMA, collagen I, fibronectin, and TGF beta 1 increased gradually. Concomitantly, AdIGFBPrP1 upregulated TGF beta 1, alpha-SMA, collagen I, fibronectin, and p-Smad2/3 in a time-dependent manner while IGFBPrP1 expression was decreased at 96 hours. Inhibition of TGF beta 1 expression reduced the IGFBPrP1-stimulated expression of alpha-SMA, collagen I, fibronectin, and p-Smad2/3. CONCLUSIONS: These findings for the first time suggest the existence of a possible mutually regulation between IGFBPrP1 and TGF beta 1, which likely accelerates liver fibrosis progression. Furthermore, IGFBPrP1 likely participates in liver fibrosis in a TGF beta 1-depedent manner, and may act as an upstream regulatory factor of TGF beta 1 in the Smad pathway.展开更多
The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the poss...The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 （control group）, 25, 50 and 100 μg/mL （CRP groups） for 24 h. In PDTC （a specific NF-κB inhibitor） group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media （CM） and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α （IκB-α） and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.展开更多
文摘HIV-1 matrix protein (MA) is a multifunctional structural protein localized on N terminus of Gag precursor p55. MA participates in HIV-1 assembly as membranotropic part of Gag precursor as well as an individual protein spliced from Gag early in infection. MA is found in the nuclei of infected cells and in plasma membrane, the site of virus assembly, in association with viral genome RNA. MA mutated variant M4 which contains two changed amino acids in N-terminal regions is also associated with viral RNA, but it is localized in the nuclear and cytoskeleton fractions but not in the plasma membrane suggesting that the mutant is deprived of membranotropic signal and “sticks” in the nuclei an d cytoskeleton, its previous location sites. These data allow suggesting that MA involved into transmission of viral RNA is transported to plasma membrane by cytoskeleton.
基金supported by NIH grants Jian-Quan Feng (DE018486) and to Chun-Lin Qin (DE005092)State Key Laboratory of Oral Diseases Open Funding (SKLODOF2010-03) to Jian-Quan Feng
文摘Deletion or mutation of dentin matrix protein 1 （DMP1） leads to hypophosphatemic rickets and defects within the dentin. However, it is largely unknown if this pathological change is a direct role of DMP1 or an indirect role of phosphate （Pi） or both. It has also been previously shown that Klotho-deficient mice, which displayed a high Pi level due to a failure of Pi excretion, causes mild defects in the dentinal structure. This study was to address the distinct roles of DMP1 and Pi homeostasis in cell differentiation, apoptosis and mineralization of dentin and enamel. Our working hypothesis was that a stable Pi homeostasis is critical for postnatal tooth formation, and that DMP1 has an antiapoptotic role in both amelogenesis and dentinogenesis. To test this hypothesis, Dmpl-null （Dmpl-/-）, Klotho-deficient （kl/kl）, Dmpl/Klotho-double-deficient （Dmpl-/-/kl/kl） and wild-type （WT） mice were killed at the age of 6 weeks. Combinations of X-ray, microcomputed tomography （I^CT）, scanning electron microscopy （SEM）, histology, apoptosis and immunohistochemical methods were used for characterization of dentin, enamel and pulp structures in these mutant mice. Our results showed that Dmpl-/- （a low Pi level） or kl/kl（a high Pi level） mice displayed mild dentin defects such as thin dentin and a reduction of dentin tubules. Neither deficient mouse line exhibited any apparent changes in enamel or pulp structure. However, the double-deficient mice （a high Pi level） displayed severe defects in dentin and enamel structures, including loss of dentinal tubules and enamel prisms, as well as unexpected ectopic ossification within the pulp root canal. TUNEL assay showed a sharp increase in apoptotic cells in ameloblasts and odontoblasts. Based on the above findings, we conclude that DMP1 has a protective role for odontoblasts and ameloblasts in a pro-apoptotic environment （a high Pi level）.
基金Supported by Jiangxi Provincial Health and Family Planning Commission“Science and Technology Plan”.
文摘BACKGROUND Osteoporosis is a systemic bone disease characterized by decreased bone mass,impaired bone mass,and reduced bone strength that leads to increased bone fragility and fracture.Type 2 diabetes mellitus(T2DM)complicated with osteoporosis is a common systemic metabolic bone disease,and reduced bone mass and bone strength are considered the main clinical features;however,the pathogenesis of this disease has not been fully clarified.Its occurrence is considered related to sex,age,and genetic factors.There are many risk factors for diabetes complicated with osteoporosis.Therefore,exploring these risk factors will help prevent it.AIM To investigate the relationships among serum glucagon-like peptide-1(GLP-1)levels,matrix Gla protein(MGP)levels,and diabetes with osteoporosis.METHODS Sixty patients with T2DM complicated with osteoporosis confirmed by the endocrinology department of our hospital were selected as the case group.Sixty T2DM patients with bone loss were selected as the control group.Sixty healthy participants were selected as the healthy group.The general data,bone mineral density index,and bone metabolic markers of the three groups were compared.The relationships among GLP-1 levels,MGP levels,and the bone mineral density index of the case group were analyzed using linear correlation analysis and a logistic regression model.RESULTS Differences in sex,smoking,and drinking among the case group,control group,and healthy group were not statistically significant(P>0.05).The mean age of the case group was older than those of the control and healthy groups(P<0.05).The body mass index,fasting plasma glucose level,HbA1c level,hypertension rate,and coronary heart disease rate of the case and control groups were higher than those of the healthy group(P<0.05).The serum GLP-1 and MGP levels of the case group were lower than those of the control and healthy groups;these differences were statistically significant(P<0.05).The serum GLP-1 and MGP levels of the control group were lower than those of the healthy group;these differences were statistically significant(P<0.05).The serum GLP-1 and MGP levels of the case group were significantly positively correlated with the bone mineral density values of the hip and lumbar spine(P<0.05).The results of the logistic regression model showed that age and duration of diabetes were independent risk factors for osteoporosis in diabetic patients(P<0.05)and that increased GLP-1 and MGP values were protective factors against osteoporosis in diabetic patients(P<0.05).CONCLUSION Serum GLP-1 and MGP levels of diabetic patients with osteoporosis were significantly decreased and positively correlated with bone mineral density and were independent risk factors for osteoporosis in diabetic patients.
基金Supported by National Natural Science Foundation of China (30421003,30828004)
文摘Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.
文摘目的观察腺苷预处理对大鼠脑缺血再灌注后基质金属蛋白酶9(MMP-9)和闭锁连接蛋白1(ZO-1)表达变化的影响。方法108只健康雄性SD大鼠随机分为对照组、模型组、腺苷组(n=36)。造模前腺苷组腹腔注射腺苷注射液,对照组和模型组大鼠在相同时间点腹腔注射2 ml生理盐水。采用改良的线栓法栓塞右侧大脑中动脉阻断血流2 h后,将线拔出形成再灌注。再灌注24 h后,伊文思蓝(EB)渗透法测定血脑屏障通透性,检测MMP-9和ZO-1表达。结果模型组和腺苷组EB,脑含水量,MMP-9明显高于对照组,ZO-1明显低于对照组(P<0.01);模型组和腺苷组MMP-9/β肌动蛋白(β-actin)表达明显高于对照组(0.563±0.054和0.377±0.080 vs 0.242±0.021,P<0.01),ZO-1/β-actin表达明显低于对照组(0.186±0.042和0.393±0.075 vs 0.671±0.065,P<0.01)。腺苷组MMP-9/β-actin表达低于模型组,ZO-1/β-actin表达明显高于模型组(P<0.01)。结论腺苷预处理可以通过抑制MMP-9表达,增加ZO-1表达,改善血脑屏障完整性,减轻脑水肿与脑缺血再灌注后的神经损伤。
基金supported by grants from National Natural Science Foundation of China(81670559)Key Research and Development Project of Shanxi Province(201603D421023)+2 种基金Youth Fund of Shanxi Medical University(02201514)Graduate Student Education Innovation Project of Shanxi(2016BY077)Youth Fund of Ap-plied Basic Research Program of Shanxi(201701D221175)
文摘Background: Previous research suggested that insulin-like growth factor binding protein related protein 1(IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases(MMP) and tissue inhibitors of metalloproteinases(TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix(ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis. Methods: Hepatic fibrosis was induced by thioacetamide(TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog(Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin( α-SMA), transforming growth factor β 1(TGF β1), collagen I, MMPs/TIMPs, Sonic Hedgehog(Shh), and glioblastoma family transcription factors(Gli1) were investigated by immunohistochemical staining and Western blotting analysis. Results: We found that hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGF β1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance. Conclusions: Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGF β1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.
基金supported by a grant from the Shanxi Province Foundation for Returness(2012-4)
文摘BACKGROUND: We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGF beta 1) is known as the strongest effector of liver fibrosis. Therefore, we aimed to investigate the detailed interaction between IGFBPrP1 and TGF beta 1 in primary hepatic stellate cells (HSCs). METHODS: We overexpressed TGF beta 1 or IGFBPrP1 and inhibited TGF beta 1 expression in primary HSCs for 6, 12, 24, 48, 72, and 96 hours to investigate their interaction and observe the accompanying expressions of a-smooth muscle actin (alpha-SMA), collagen I, fibronectin, and phosphorylated-mothers against decapentaplegic homolog 2/3 (p-Smad2/3). RESULTS: We found that the adenovirus vector encoding the TGF beta 1 gene (AdTGF beta 1) induced IGFBPrP1 expression while that of alpha-SMA, collagen I, fibronectin, and TGF beta 1 increased gradually. Concomitantly, AdIGFBPrP1 upregulated TGF beta 1, alpha-SMA, collagen I, fibronectin, and p-Smad2/3 in a time-dependent manner while IGFBPrP1 expression was decreased at 96 hours. Inhibition of TGF beta 1 expression reduced the IGFBPrP1-stimulated expression of alpha-SMA, collagen I, fibronectin, and p-Smad2/3. CONCLUSIONS: These findings for the first time suggest the existence of a possible mutually regulation between IGFBPrP1 and TGF beta 1, which likely accelerates liver fibrosis progression. Furthermore, IGFBPrP1 likely participates in liver fibrosis in a TGF beta 1-depedent manner, and may act as an upstream regulatory factor of TGF beta 1 in the Smad pathway.
文摘The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 （control group）, 25, 50 and 100 μg/mL （CRP groups） for 24 h. In PDTC （a specific NF-κB inhibitor） group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media （CM） and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α （IκB-α） and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.
