Over the last few years, it has become evident that reactive oxygen species （ROS） signalling plays an important role in various physiological responses, including pathogen defense and stomatal opening/closure. On th...Over the last few years, it has become evident that reactive oxygen species （ROS） signalling plays an important role in various physiological responses, including pathogen defense and stomatal opening/closure. On the other hand, ROS overproduction is detrimental for proper plant growth and development, indicating that the regulation of an appropriate redox balance is essential for plants. ROS homeostasis in plants involves the mitogen-activated protein kinase （MAPK） pathway consisting of the MAPK kinase kinase MEKK1 and the MAPK MPK4. Phenotypic and molecular analysis revealed that the MAPK kinases MKK1 and MKK2 are part of a cascade, regulating ROS and salicylic acid （SA） accumulation. Gene expression analysis shows that of 32 transcription factors reported to be highly responsive to multiple ROS-inducing conditions, 20 are regulated by the MEKK1, predominantly via the MEKK1-MKK1/2-MPK4 pathway. However, MEKK1 also functions on other as yet unknown pathways and part of the MEKK1-dependent MPK4 responses are regulated independently of MKK1 and MKK2. Overall, this analysis emphasizes the central role of this MAPK cascade in oxidative stress signalling, but also indicates the high level of complexity revealed by this signalling network.展开更多
Background Recent studies have suggested that p38 mitogen-activated protein kinases （MAPK） signalling pathway plays an important role in hepatic fibrosis. This study explored the antifibrotic effect of oxymatrine on...Background Recent studies have suggested that p38 mitogen-activated protein kinases （MAPK） signalling pathway plays an important role in hepatic fibrosis. This study explored the antifibrotic effect of oxymatrine on tetrachloromethane induced liver fibrosis in rats and its modulation on the p38 MAPK signalling pathway. Methods One hundred and twenty healthy male Sprague-Dawley rats were randomly assigned to six groups： normal （n=20）, induced fibrosis （n=20）, colchicine （n=20） and three treatment groups of oxymatrine （n=20x3）. We obesrved changes in deposition of collagen, hyaluronic acid （HA）, laminin （LN）, collagen type IV （CIV）, procollagen III （PCIll） and hydroxyproline （Hyp）, a-smooth muscle actin （α-SMA） and phosphor-p38 （pp38）. Results The relative indicators of changes in histopathology, HA, LN, CIV, PCIII, Hyp, a-SMA and pp38 were raised significantly in the induced fibrosis group （P〈0.01 vs normal group）. The semiquantitative hepatic fibrosis staging scores of middle dose group and high dose group were decreased （P 〈0.05 and P 〈0.01 respectively vs the induced fibrosis group）, as was the average area of collagen in rats＇ liver, the concentrations of serum HA, LN, CIV, PCIII and liver tissue homogenate Hyp. The gene expression of α-SMA mRNA was considerably decreased in the treated animals, as was the protein espression of pp38 protein. Conclusions Oxymatrine is effective in reducing the production and deposition of collagen in the liver tissue of experimental rats in ways which relate to modulating the fibrogenic signal transduction via p38 MAPK signalling pathway.展开更多
Refined-JQ(JQ-R) is a mixture of refined extracts from Coptis chinensis(Ranunculaceae),Astragalus membranaceus(Leguminosae) and Lonicera japonica(Caprifoliaceae), the three major herbs of Jin Qi-Jiang Tang tablet, a t...Refined-JQ(JQ-R) is a mixture of refined extracts from Coptis chinensis(Ranunculaceae),Astragalus membranaceus(Leguminosae) and Lonicera japonica(Caprifoliaceae), the three major herbs of Jin Qi-Jiang Tang tablet, a traditional Chinese medicine(TCM) formula. The mechanisms by which JQ-R regulates glucose metabolism and improves insulin sensitivity were studied in type 2 diabetic KK^(Ay)mice and insulin-resistant L6 myotubes. To investigate the mechanisms by which JQ-R improves insulin sensitivity, a model of insulin-resistant cells induced with palmitic acid(PA) was established in L6 myotubes. Glucose uptake and expression of factors involved in insulin signaling, stress, and inflammatory pathways were detected by immunoblotting. JQ-R showed beneficial effects on glucose homeostasis and insulin resistance in a euglycemic clamp experiment and decreased fasting insulin levels in diabetic KK^(Ay)mice. JQ-R also improved the plasma lipid profiles. JQ-R directly increased the activity of superoxide dismutase(SOD) and decreased malondialdehyde(MDA) as well as inducible nitric oxide synthase(iNOS) levels in insulin-resistant L6 cells, and elevated the insulin-stimulated glucose uptake with upregulated phosphorylation of AKT. The phosphorylation levels of nuclear factor kappa B(NF-κB p65), inhibitor of NF-κB(IκBα), c-Jun N-terminal kinase(JNK1/2) and extracellular-signal-regulated kinases(ERK1/2) were also changed after JQ-R treatment compared with the control group. Together these findings suggest that JQ-R improved glucose and lipid metabolism in diabetic KK^(Ay)mice. JQ-R directly enhanced insulin-stimulated glucose uptake in insulin-resistant myotubes with improved insulin signalling and inflammatory response and oxidative stress. JQ-R could be a candidate to achieve improved glucose metabolism and insulin sensitivity in type 2 diabetes mellitus.展开更多
Major advances have been made over the last decade in our understanding of the molecular basis ofseveral cardiac conditions. Hypertrophic cardiomyopathy (HCM) was the first cardiac disorder in whicha genetic basis was...Major advances have been made over the last decade in our understanding of the molecular basis ofseveral cardiac conditions. Hypertrophic cardiomyopathy (HCM) was the first cardiac disorder in whicha genetic basis was identified and as such, has acted as a paradigm for the study of an inherited cardiacdisorder. HCM can result in clinical symptoms ranging from no symptoms to severe heart failure andpremature sudden death. HCM is the commonest cause of sudden death in those aged less than 35 years,including competitive athletes. At least ten genes have now been identified, defects in which cause HCM.All of these genes encode proteins which comprise the basic contractile unit of the heart, i.e. the sarcomere.While much is now known about which genes cause disease and the various clinical presentations, very littleis known about how these gene defects cause disease, and what factors modify the expression of the mutantgenes. Studies in both cell culture and animal models of HCM are now beginning to shed light on thesignalling pathways involved in HCM, and the role of both environmental and genetic modifying factors.Understanding these mechanisms will ultimately improve our knowledge of the basic biology of heart musclefunction, and will therefore provide new avenues for treating cardiovascular disease in man.展开更多
Colorectal carcinogenesis(CRC) imposes a major health burden in developing countries. It is the third major cause of cancer deaths. Despite several treatment strategies, novel drugs are warranted to reduce the severit...Colorectal carcinogenesis(CRC) imposes a major health burden in developing countries. It is the third major cause of cancer deaths. Despite several treatment strategies, novel drugs are warranted to reduce the severity of this disease. Adenomatous polyps in the colon are the major culprits in CRC and found in 45% of cancers, especially in patients 60 years of age. Inflammatory polyps are currently gaining attention in CRC, and a growing body of evidence denotes the role of inflammation in CRC. Several experimental models are being employed to investigate CRC in animals, which include the APC^(min/+) mouse model, Azoxymethane, Dimethyl hydrazine, and a combination of Dextran sodium sulphate and dimethyl hydrazine. During CRC progression, several signal transduction pathways are activated. Among the major signal transduction pathways are p53, Transforming growth factor beta, Wnt/β-catenin, Delta Notch, Hippo signalling, nuclear factor erythroid 2-related factor 2 and Kelch-like ECH-associated protein 1 pathways. These signalling pathways collaborate with cell death mechanisms, which include apoptosis, necroptosis and autophagy, to determine cell fate. Extensive research has been carried out in our laboratory to investigate these signal transduction and cell death mechanistic pathways in CRC. This review summarizes CRC pathogenesis and the related cell death and signal transduction pathways.展开更多
The serum and glucocorticoid inducible protein kinase(SGK) family members share similar structure, substrate specificity and function with AKT and signal downstream of the phosphatidylinositol 3-kinase(PI3K) signallin...The serum and glucocorticoid inducible protein kinase(SGK) family members share similar structure, substrate specificity and function with AKT and signal downstream of the phosphatidylinositol 3-kinase(PI3K) signalling pathway. They regulate a range of fundamental cellular processes such as cell proliferation and survival, thereby playing an important role in cancer development. This perspective intends to give an overview on the involvement of SGKs(particularly SGK3) in cancer progression, and compares the actions of SGK3 and AKT in cell cycle regulation, oncogenic signalling, and the potential as a therapeutic target for cancer.展开更多
Calcium and Reactive Oxygen Species （ROS） are acknowledged as crucial second messengers involved in the response to various biotic and abiotic stresses. However, it is still not clear how these two compounds can pla...Calcium and Reactive Oxygen Species （ROS） are acknowledged as crucial second messengers involved in the response to various biotic and abiotic stresses. However, it is still not clear how these two compounds can play a role in different signaling pathways leading the plant to a variety of processes such as root development or defense against pathogens. Recently, it has been shown that the concept of calcium and ROS signatures, initially discovered in the cytoplasm, can also be extended to the nucleus of plant cells. In addition, it has been clearly proved that both ROS and calcium signals are intimately interconnected. How this cross-talk can finally modulate the translocation and/or the activity of nuclear proteins leading to the control of specific genes expression is the main focus of this review. We will especially focus on how calcium and ROS interact at the molecular level to modify their targets.展开更多
Liver cancer is the fifth and seventh most common cause of cancer in men and women,respectively.Wnt/β-catenin signalling has emerged as a critical player in both the development of normal liver as well as an oncogeni...Liver cancer is the fifth and seventh most common cause of cancer in men and women,respectively.Wnt/β-catenin signalling has emerged as a critical player in both the development of normal liver as well as an oncogenic driver in hepatocellular carcinoma(HCC).Based on the current understanding,this article summarizes the possible mechanisms for the aberrant activation of this pathway with specific focus on HCC.Furthermore,we will discuss the role of dickkopfs(DKKs)in regulating Wnt/β-catenin signalling,which is poorly understood and understudied.DKKs are a family of secreted proteins that comprise at least four members,namely DKK1-DKK4,which act as inhibitors of Wnt/β-catenin signalling.Nevertheless,not all members antagonize Wnt/β-catenin signalling.Their functional significance in hepatocarcinogenesis remains to be further characterized for which these studies should provide new insights into the regulatory role of DKKs in Wnt/β-catenin signalling in hepatic carcinogenesis.Because of the important oncogenic roles,there are an increasing number of therapeutic molecules targetingβ-catenin and the Wnt/β-catenin pathway for potential therapy of HCC.展开更多
The plasma membrane calcium ATPases(PMCA) are a family of genes which extrude Ca2+from the cell and are involved in the maintenance of intracellular free calcium levels and/or with Ca2+signalling,depending on the cell...The plasma membrane calcium ATPases(PMCA) are a family of genes which extrude Ca2+from the cell and are involved in the maintenance of intracellular free calcium levels and/or with Ca2+signalling,depending on the cell type.In the cardiovascular system,Ca2+ is not only essential for contraction and relaxation but also has a vital role as a second messenger in signal transduction pathways.A complex array of mechanisms regulate intracellular free calcium levels in the heart and vasculature and a failure in these systems to maintain normal Ca2+homeostasis has been linked to both heart failure and hypertension.This article focuses on the functions of PMCA,in particular isoform 4(PMCA4) ,in the heart and vasculature and the reported links between PMCAs and contractile function,cardiac hypertrophy,cardiac rhythm and sudden cardiac death,and blood pressure control and hypertension.It is becoming clear that this family of calcium extrusion pumps have essential roles in both cardiovascular health and disease.展开更多
Our previous study demonstrated that a chloroplast co-chaperonin 20(CPN20),one of the interaction partners of the magnesium-protoporphyrin IX chelatase H subunit(CHLH/ABAR),negatively regulates ABA signaling at the sa...Our previous study demonstrated that a chloroplast co-chaperonin 20(CPN20),one of the interaction partners of the magnesium-protoporphyrin IX chelatase H subunit(CHLH/ABAR),negatively regulates ABA signaling at the same node with ABAR but upstream of WRKY40 transcription repressor in Arabidopsis thaliana.In the present experiment,we showed that ABA directly inhibits the ABAR-CPN20 interaction,and also represses expression of CPN20,which depends on ABAR.CPN20 inhibits ABAR-WRKY40 interaction by competitively binding to ABAR.ABAR downregulates,but CPN20 upregulates,WRKY40 expression.The cpn20-1 mutation induces downregulation of WRKY40,and suppresses the upregulated level of WRKY40 due to the cch mutation in the ABAR gene.ABA-induced repressive effect of the WRKY40 gene is strengthened by downregulation of CPN20 but reduced by upregulation of CPN20.Together with our previously reported genetic data,we provide evidence that CPN20 functions through antagonizing the ABAR-WRKY40 coupled pathway,and ABA relieves this pathway of repression by inhibiting the ABAR-CPN20 interaction to activate ABAR-WRKY40 interaction.展开更多
During mammalian fertilisation, the zona pellucida （ZP） matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction （AR） in the ZP-bound spe...During mammalian fertilisation, the zona pellucida （ZP） matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction （AR） in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four （ZP1, ZP2, ZP3 and ZP4）. ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans （in addition to ZP3）, ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the Gi-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels （VOCCs）, whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans （in addition to ZP3）, ZP1 and ZP4 also participate in these stages of fertilisation.展开更多
Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs...Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs);however,because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism.Our previous studies revealed that the expansion of CD26+KFs was responsible for increased keloid proliferation and invasion capabilities;the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation.The aim of this studywas to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities,and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.Methods:Flow cytometry was performed to isolate CD26+/CD26−fibroblasts from KFs and normal fibroblasts.To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor(IGF-1R),lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection.Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2-deoxyuridine(EdU)incorporation assay.Scratching assay and transwell assay were used to assess cell migration and invasion abilities.To further quantify the regulatory role of CD26 expression in the relevant signalling pathway,RT-qPCR,western blot,ELISA,PI3K activity assay and immunofluorescence were used.Results:Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs.Furthermore,the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion.The PI3K/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.Conclusions:CD26 can be the effective biomarker for KFs,and its expression is closely relat展开更多
Ghrelin is a 28 amino acid peptide mainly derived from the oxyntic gland of the stomach. Both acylated(AG) and unacylated(UAG) forms of ghrelin are found in the circulation. Initially, AG was considered as the only bi...Ghrelin is a 28 amino acid peptide mainly derived from the oxyntic gland of the stomach. Both acylated(AG) and unacylated(UAG) forms of ghrelin are found in the circulation. Initially, AG was considered as the only bioactive form of ghrelin. However, recent advances indicate that both AG and UAG exert distinct and common effects in organisms. Soon after its discovery, ghrelin was shown to promote appetite and adiposity in animal and human models. In response to these anabolic effects, an impressive number of elements have suggested the influence of ghrelin on the regulation of metabolic functions and the development of obesityrelated disorders. However, due to the complexity ofits biochemical nature and the physiological processes it governs, some of the effects of ghrelin are still debated in the literature. Evidence suggests that ghrelin influences glucose homeostasis through the modulation of insulin secretion and insulin receptor signaling. On the other hand, insulin was also shown to influence circulating levels of ghrelin. Here, we review the relationship between ghrelin and insulin and we describe the impact of this interaction on the modulation of glucose homeostasis.展开更多
文摘Over the last few years, it has become evident that reactive oxygen species （ROS） signalling plays an important role in various physiological responses, including pathogen defense and stomatal opening/closure. On the other hand, ROS overproduction is detrimental for proper plant growth and development, indicating that the regulation of an appropriate redox balance is essential for plants. ROS homeostasis in plants involves the mitogen-activated protein kinase （MAPK） pathway consisting of the MAPK kinase kinase MEKK1 and the MAPK MPK4. Phenotypic and molecular analysis revealed that the MAPK kinases MKK1 and MKK2 are part of a cascade, regulating ROS and salicylic acid （SA） accumulation. Gene expression analysis shows that of 32 transcription factors reported to be highly responsive to multiple ROS-inducing conditions, 20 are regulated by the MEKK1, predominantly via the MEKK1-MKK1/2-MPK4 pathway. However, MEKK1 also functions on other as yet unknown pathways and part of the MEKK1-dependent MPK4 responses are regulated independently of MKK1 and MKK2. Overall, this analysis emphasizes the central role of this MAPK cascade in oxidative stress signalling, but also indicates the high level of complexity revealed by this signalling network.
文摘Background Recent studies have suggested that p38 mitogen-activated protein kinases （MAPK） signalling pathway plays an important role in hepatic fibrosis. This study explored the antifibrotic effect of oxymatrine on tetrachloromethane induced liver fibrosis in rats and its modulation on the p38 MAPK signalling pathway. Methods One hundred and twenty healthy male Sprague-Dawley rats were randomly assigned to six groups： normal （n=20）, induced fibrosis （n=20）, colchicine （n=20） and three treatment groups of oxymatrine （n=20x3）. We obesrved changes in deposition of collagen, hyaluronic acid （HA）, laminin （LN）, collagen type IV （CIV）, procollagen III （PCIll） and hydroxyproline （Hyp）, a-smooth muscle actin （α-SMA） and phosphor-p38 （pp38）. Results The relative indicators of changes in histopathology, HA, LN, CIV, PCIII, Hyp, a-SMA and pp38 were raised significantly in the induced fibrosis group （P〈0.01 vs normal group）. The semiquantitative hepatic fibrosis staging scores of middle dose group and high dose group were decreased （P 〈0.05 and P 〈0.01 respectively vs the induced fibrosis group）, as was the average area of collagen in rats＇ liver, the concentrations of serum HA, LN, CIV, PCIII and liver tissue homogenate Hyp. The gene expression of α-SMA mRNA was considerably decreased in the treated animals, as was the protein espression of pp38 protein. Conclusions Oxymatrine is effective in reducing the production and deposition of collagen in the liver tissue of experimental rats in ways which relate to modulating the fibrogenic signal transduction via p38 MAPK signalling pathway.
基金partly supported by the CAMS Innovation Fund for Medical Sciences,China(CIFMS,No.2016-12M-4-001)CAMS Initiative for Innovative Medicine,China(CAMS-I2M,No.2016-I2M-2–006)
文摘Refined-JQ(JQ-R) is a mixture of refined extracts from Coptis chinensis(Ranunculaceae),Astragalus membranaceus(Leguminosae) and Lonicera japonica(Caprifoliaceae), the three major herbs of Jin Qi-Jiang Tang tablet, a traditional Chinese medicine(TCM) formula. The mechanisms by which JQ-R regulates glucose metabolism and improves insulin sensitivity were studied in type 2 diabetic KK^(Ay)mice and insulin-resistant L6 myotubes. To investigate the mechanisms by which JQ-R improves insulin sensitivity, a model of insulin-resistant cells induced with palmitic acid(PA) was established in L6 myotubes. Glucose uptake and expression of factors involved in insulin signaling, stress, and inflammatory pathways were detected by immunoblotting. JQ-R showed beneficial effects on glucose homeostasis and insulin resistance in a euglycemic clamp experiment and decreased fasting insulin levels in diabetic KK^(Ay)mice. JQ-R also improved the plasma lipid profiles. JQ-R directly increased the activity of superoxide dismutase(SOD) and decreased malondialdehyde(MDA) as well as inducible nitric oxide synthase(iNOS) levels in insulin-resistant L6 cells, and elevated the insulin-stimulated glucose uptake with upregulated phosphorylation of AKT. The phosphorylation levels of nuclear factor kappa B(NF-κB p65), inhibitor of NF-κB(IκBα), c-Jun N-terminal kinase(JNK1/2) and extracellular-signal-regulated kinases(ERK1/2) were also changed after JQ-R treatment compared with the control group. Together these findings suggest that JQ-R improved glucose and lipid metabolism in diabetic KK^(Ay)mice. JQ-R directly enhanced insulin-stimulated glucose uptake in insulin-resistant myotubes with improved insulin signalling and inflammatory response and oxidative stress. JQ-R could be a candidate to achieve improved glucose metabolism and insulin sensitivity in type 2 diabetes mellitus.
文摘Major advances have been made over the last decade in our understanding of the molecular basis ofseveral cardiac conditions. Hypertrophic cardiomyopathy (HCM) was the first cardiac disorder in whicha genetic basis was identified and as such, has acted as a paradigm for the study of an inherited cardiacdisorder. HCM can result in clinical symptoms ranging from no symptoms to severe heart failure andpremature sudden death. HCM is the commonest cause of sudden death in those aged less than 35 years,including competitive athletes. At least ten genes have now been identified, defects in which cause HCM.All of these genes encode proteins which comprise the basic contractile unit of the heart, i.e. the sarcomere.While much is now known about which genes cause disease and the various clinical presentations, very littleis known about how these gene defects cause disease, and what factors modify the expression of the mutantgenes. Studies in both cell culture and animal models of HCM are now beginning to shed light on thesignalling pathways involved in HCM, and the role of both environmental and genetic modifying factors.Understanding these mechanisms will ultimately improve our knowledge of the basic biology of heart musclefunction, and will therefore provide new avenues for treating cardiovascular disease in man.
基金Council of Scientific and Industrial research (CSIR),New Delhi for funding Colon cancer project [37(1364)/09/EMR-Ⅱ]
文摘Colorectal carcinogenesis(CRC) imposes a major health burden in developing countries. It is the third major cause of cancer deaths. Despite several treatment strategies, novel drugs are warranted to reduce the severity of this disease. Adenomatous polyps in the colon are the major culprits in CRC and found in 45% of cancers, especially in patients 60 years of age. Inflammatory polyps are currently gaining attention in CRC, and a growing body of evidence denotes the role of inflammation in CRC. Several experimental models are being employed to investigate CRC in animals, which include the APC^(min/+) mouse model, Azoxymethane, Dimethyl hydrazine, and a combination of Dextran sodium sulphate and dimethyl hydrazine. During CRC progression, several signal transduction pathways are activated. Among the major signal transduction pathways are p53, Transforming growth factor beta, Wnt/β-catenin, Delta Notch, Hippo signalling, nuclear factor erythroid 2-related factor 2 and Kelch-like ECH-associated protein 1 pathways. These signalling pathways collaborate with cell death mechanisms, which include apoptosis, necroptosis and autophagy, to determine cell fate. Extensive research has been carried out in our laboratory to investigate these signal transduction and cell death mechanistic pathways in CRC. This review summarizes CRC pathogenesis and the related cell death and signal transduction pathways.
基金supported by grants from the Ministry of Science and Technology of China (2014DFG32200)Shanghai Science and Technology Development Fund (15DZ2291600)the Thousand Talents Program in China ([2011]166)
文摘The serum and glucocorticoid inducible protein kinase(SGK) family members share similar structure, substrate specificity and function with AKT and signal downstream of the phosphatidylinositol 3-kinase(PI3K) signalling pathway. They regulate a range of fundamental cellular processes such as cell proliferation and survival, thereby playing an important role in cancer development. This perspective intends to give an overview on the involvement of SGKs(particularly SGK3) in cancer progression, and compares the actions of SGK3 and AKT in cell cycle regulation, oncogenic signalling, and the potential as a therapeutic target for cancer.
文摘Calcium and Reactive Oxygen Species （ROS） are acknowledged as crucial second messengers involved in the response to various biotic and abiotic stresses. However, it is still not clear how these two compounds can play a role in different signaling pathways leading the plant to a variety of processes such as root development or defense against pathogens. Recently, it has been shown that the concept of calcium and ROS signatures, initially discovered in the cytoplasm, can also be extended to the nucleus of plant cells. In addition, it has been clearly proved that both ROS and calcium signals are intimately interconnected. How this cross-talk can finally modulate the translocation and/or the activity of nuclear proteins leading to the control of specific genes expression is the main focus of this review. We will especially focus on how calcium and ROS interact at the molecular level to modify their targets.
文摘Liver cancer is the fifth and seventh most common cause of cancer in men and women,respectively.Wnt/β-catenin signalling has emerged as a critical player in both the development of normal liver as well as an oncogenic driver in hepatocellular carcinoma(HCC).Based on the current understanding,this article summarizes the possible mechanisms for the aberrant activation of this pathway with specific focus on HCC.Furthermore,we will discuss the role of dickkopfs(DKKs)in regulating Wnt/β-catenin signalling,which is poorly understood and understudied.DKKs are a family of secreted proteins that comprise at least four members,namely DKK1-DKK4,which act as inhibitors of Wnt/β-catenin signalling.Nevertheless,not all members antagonize Wnt/β-catenin signalling.Their functional significance in hepatocarcinogenesis remains to be further characterized for which these studies should provide new insights into the regulatory role of DKKs in Wnt/β-catenin signalling in hepatic carcinogenesis.Because of the important oncogenic roles,there are an increasing number of therapeutic molecules targetingβ-catenin and the Wnt/β-catenin pathway for potential therapy of HCC.
文摘The plasma membrane calcium ATPases(PMCA) are a family of genes which extrude Ca2+from the cell and are involved in the maintenance of intracellular free calcium levels and/or with Ca2+signalling,depending on the cell type.In the cardiovascular system,Ca2+ is not only essential for contraction and relaxation but also has a vital role as a second messenger in signal transduction pathways.A complex array of mechanisms regulate intracellular free calcium levels in the heart and vasculature and a failure in these systems to maintain normal Ca2+homeostasis has been linked to both heart failure and hypertension.This article focuses on the functions of PMCA,in particular isoform 4(PMCA4) ,in the heart and vasculature and the reported links between PMCAs and contractile function,cardiac hypertrophy,cardiac rhythm and sudden cardiac death,and blood pressure control and hypertension.It is becoming clear that this family of calcium extrusion pumps have essential roles in both cardiovascular health and disease.
基金supported by the National Key Basic Research Program of China(2012CB114302)National Natural Science Foundation of China(90817104 and 31170268)Ministry of Agriculture of China(2013ZX08009-003)
文摘Our previous study demonstrated that a chloroplast co-chaperonin 20(CPN20),one of the interaction partners of the magnesium-protoporphyrin IX chelatase H subunit(CHLH/ABAR),negatively regulates ABA signaling at the same node with ABAR but upstream of WRKY40 transcription repressor in Arabidopsis thaliana.In the present experiment,we showed that ABA directly inhibits the ABAR-CPN20 interaction,and also represses expression of CPN20,which depends on ABAR.CPN20 inhibits ABAR-WRKY40 interaction by competitively binding to ABAR.ABAR downregulates,but CPN20 upregulates,WRKY40 expression.The cpn20-1 mutation induces downregulation of WRKY40,and suppresses the upregulated level of WRKY40 due to the cch mutation in the ABAR gene.ABA-induced repressive effect of the WRKY40 gene is strengthened by downregulation of CPN20 but reduced by upregulation of CPN20.Together with our previously reported genetic data,we provide evidence that CPN20 functions through antagonizing the ABAR-WRKY40 coupled pathway,and ABA relieves this pathway of repression by inhibiting the ABAR-CPN20 interaction to activate ABAR-WRKY40 interaction.
文摘During mammalian fertilisation, the zona pellucida （ZP） matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction （AR） in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four （ZP1, ZP2, ZP3 and ZP4）. ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans （in addition to ZP3）, ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the Gi-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels （VOCCs）, whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans （in addition to ZP3）, ZP1 and ZP4 also participate in these stages of fertilisation.
基金supported by the National Natural Science Foundation of China(81772098,81801917,81801918)the Outstanding Professional and Technical Leader Program of the Shanghai Municipal Science and Technology Commission(18XD1423700)+3 种基金the Clinical Multi-Disciplinary Team Research Program of 9th People’s Hospital,Shanghai Jiao Tong University School of Medicine(2017-1-007)the Clinical Research Program of 9th People’s Hospital,Shanghai Jiao Tong University School of Medicine(JYLJ027)the Shanghai Municipal Education Commission Gaofeng Clinical Medicine Grant Support(20152227)the project of Science and Technology Commission of Shanghai Municipality(17411952800,18441904500).
文摘Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs);however,because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism.Our previous studies revealed that the expansion of CD26+KFs was responsible for increased keloid proliferation and invasion capabilities;the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation.The aim of this studywas to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities,and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.Methods:Flow cytometry was performed to isolate CD26+/CD26−fibroblasts from KFs and normal fibroblasts.To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor(IGF-1R),lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection.Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2-deoxyuridine(EdU)incorporation assay.Scratching assay and transwell assay were used to assess cell migration and invasion abilities.To further quantify the regulatory role of CD26 expression in the relevant signalling pathway,RT-qPCR,western blot,ELISA,PI3K activity assay and immunofluorescence were used.Results:Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs.Furthermore,the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion.The PI3K/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.Conclusions:CD26 can be the effective biomarker for KFs,and its expression is closely relat
基金Supported by Fonds de Recherche du Québec en Santé(toLaplante M and St-Pierre DH)Operating grants from NaturalSciences and Engineering Research Council of Canada and Diabète QuébecLaplante M also holds operating grants from the Canadian Institutes of Health Research,Canadian Liver Foundation and the Fondation de l’Institut Universitaire de Cardiologieet de Pneumologie de Québec
文摘Ghrelin is a 28 amino acid peptide mainly derived from the oxyntic gland of the stomach. Both acylated(AG) and unacylated(UAG) forms of ghrelin are found in the circulation. Initially, AG was considered as the only bioactive form of ghrelin. However, recent advances indicate that both AG and UAG exert distinct and common effects in organisms. Soon after its discovery, ghrelin was shown to promote appetite and adiposity in animal and human models. In response to these anabolic effects, an impressive number of elements have suggested the influence of ghrelin on the regulation of metabolic functions and the development of obesityrelated disorders. However, due to the complexity ofits biochemical nature and the physiological processes it governs, some of the effects of ghrelin are still debated in the literature. Evidence suggests that ghrelin influences glucose homeostasis through the modulation of insulin secretion and insulin receptor signaling. On the other hand, insulin was also shown to influence circulating levels of ghrelin. Here, we review the relationship between ghrelin and insulin and we describe the impact of this interaction on the modulation of glucose homeostasis.
