Constitutive activation of the insulin-like growth factor (IGF)-signaling axis is frequently observed in human hepatocellular carcinoma(HCC).Especially the over- expression of the fetal growth factor IGF-Ⅱ,IGF-Ⅰ rec...Constitutive activation of the insulin-like growth factor (IGF)-signaling axis is frequently observed in human hepatocellular carcinoma(HCC).Especially the over- expression of the fetal growth factor IGF-Ⅱ,IGF-Ⅰ receptor(IGF-IR),and cytoplasmic downstream effectors such as insulin-receptor substrates(IRS)contribute to proliferation,anti-apoptosis,and invasive behavior. This review focuses on the relevant alterations in this signaling pathway and independent in vivo models that support the central role IGF-Ⅱsignaling during HCC development and progression.Since this pathway has become the center of interest as a target for potential anti-cancer therapy in many types of malignancies,various experimental strategies have been developed,including neutralizing antibodies and selective receptor kinase inhibitors,with respect to the specific and efficient reduction of oncogenic IGF-Ⅱ/IGF-IR-signaling.展开更多
Osteoporosis has become a serious health problem throughout the world which is associated with an increased risk of bone fractures and mortality among the people of middle to old ages.Diabetes is also a major health p...Osteoporosis has become a serious health problem throughout the world which is associated with an increased risk of bone fractures and mortality among the people of middle to old ages.Diabetes is also a major health problem among the people of all age ranges and the sufferers due to this abnormality increasing day by day.The aim of this review is to summarize the possible mechanisms through which diabetes may induce osteoporosis.Diabetes mellitus generally exerts its effect on different parts of the body including bone cells specially the osteoblast and osteoclast,muscles,retina of the eyes,adipose tissue,endocrine system specially parathyroid hormone(PTH) and estrogen,cytokines,nervous system and digestive system.Diabetes negatively regulates osteoblast differentiation and function while positively regulates osteoclast differentiation and function through the regulation of different intermediate factors and thereby decreases bone formation while increases bone resorption.Some factors such as diabetic neuropathy,reactive oxygen species,Vitamin D,PTH have their effects on muscle cells.Diabetes decreases the muscle strength through regulating these factors in various ways and ultimately increases the risk of fall that may cause bone fractures.展开更多
Free fatty acids are known to play a key role in promoting loss of insulin sensitivity in type 2 diabetes mellitus but the underlying mechanism is still unclear.It has been postulated that an increase in the intracell...Free fatty acids are known to play a key role in promoting loss of insulin sensitivity in type 2 diabetes mellitus but the underlying mechanism is still unclear.It has been postulated that an increase in the intracellular concentration of fatty acid metabolites activates a serine kinase cascade,which leads to defects in insu-lin signaling downstream to the insulin receptor.In addition,the complex network of adipokines released from adipose tissue modulates the response of tissues to insulin.Among the many molecules involved in the intracellular processing of the signal provided by insulin,the insulin receptor substrate-2,the protein kinase B and the forkhead transcription factor Foxo 1a are of particular interest,as recent data has provided strong evidence that dysfunction of these proteins results in insulin resistance in vivo.Recently,studies have revealed that phosphoinositidedependent kinase 1-independent phosphorylation of protein kinase Cε causes a reduction in insulin receptor gene expression.Additionally,it has been suggested that mitochondrial dysfunction triggers activation of several serine kinases,and weakens insulin signal transduction.Thus,in this review,the current developments in understanding the pathophysiological processes of insulin resistance in type 2 diabetes have been summarized.In addition,this study provides potential new targets for the treatment and prevention of type 2 diabetes.展开更多
文摘Constitutive activation of the insulin-like growth factor (IGF)-signaling axis is frequently observed in human hepatocellular carcinoma(HCC).Especially the over- expression of the fetal growth factor IGF-Ⅱ,IGF-Ⅰ receptor(IGF-IR),and cytoplasmic downstream effectors such as insulin-receptor substrates(IRS)contribute to proliferation,anti-apoptosis,and invasive behavior. This review focuses on the relevant alterations in this signaling pathway and independent in vivo models that support the central role IGF-Ⅱsignaling during HCC development and progression.Since this pathway has become the center of interest as a target for potential anti-cancer therapy in many types of malignancies,various experimental strategies have been developed,including neutralizing antibodies and selective receptor kinase inhibitors,with respect to the specific and efficient reduction of oncogenic IGF-Ⅱ/IGF-IR-signaling.
文摘Osteoporosis has become a serious health problem throughout the world which is associated with an increased risk of bone fractures and mortality among the people of middle to old ages.Diabetes is also a major health problem among the people of all age ranges and the sufferers due to this abnormality increasing day by day.The aim of this review is to summarize the possible mechanisms through which diabetes may induce osteoporosis.Diabetes mellitus generally exerts its effect on different parts of the body including bone cells specially the osteoblast and osteoclast,muscles,retina of the eyes,adipose tissue,endocrine system specially parathyroid hormone(PTH) and estrogen,cytokines,nervous system and digestive system.Diabetes negatively regulates osteoblast differentiation and function while positively regulates osteoclast differentiation and function through the regulation of different intermediate factors and thereby decreases bone formation while increases bone resorption.Some factors such as diabetic neuropathy,reactive oxygen species,Vitamin D,PTH have their effects on muscle cells.Diabetes decreases the muscle strength through regulating these factors in various ways and ultimately increases the risk of fall that may cause bone fractures.
文摘Free fatty acids are known to play a key role in promoting loss of insulin sensitivity in type 2 diabetes mellitus but the underlying mechanism is still unclear.It has been postulated that an increase in the intracellular concentration of fatty acid metabolites activates a serine kinase cascade,which leads to defects in insu-lin signaling downstream to the insulin receptor.In addition,the complex network of adipokines released from adipose tissue modulates the response of tissues to insulin.Among the many molecules involved in the intracellular processing of the signal provided by insulin,the insulin receptor substrate-2,the protein kinase B and the forkhead transcription factor Foxo 1a are of particular interest,as recent data has provided strong evidence that dysfunction of these proteins results in insulin resistance in vivo.Recently,studies have revealed that phosphoinositidedependent kinase 1-independent phosphorylation of protein kinase Cε causes a reduction in insulin receptor gene expression.Additionally,it has been suggested that mitochondrial dysfunction triggers activation of several serine kinases,and weakens insulin signal transduction.Thus,in this review,the current developments in understanding the pathophysiological processes of insulin resistance in type 2 diabetes have been summarized.In addition,this study provides potential new targets for the treatment and prevention of type 2 diabetes.
