Most defective and unwanted cells die by apoptosis, cells without damaging the surrounding tissue. Once a an exquisitely controlled genetic programme for removing such cell has committed to apoptosis, the process is r...Most defective and unwanted cells die by apoptosis, cells without damaging the surrounding tissue. Once a an exquisitely controlled genetic programme for removing such cell has committed to apoptosis, the process is remarkably efficient, and is completed within a few minutes of initiation. This point of no retum for an apoptotic cell is commonly held to be the point at which the outer mitochondrial membrane is permeabilised, a process regulated by the Bcl-2 family of proteins. How these proteins regulate this decision point is central to diseases such as cancer where apoptotic control is lost. In this review, we will discuss apoptotic signalling and how a cell makes the irreversible decision to die. We will focus on one set of survival signals, those derived by cell adhesion to the extracellular matrix （ECM）, and use these to highlight the complexities of apoptotic signalling. In particular, we will illustrate how multiple signalling pathways converge to determine critical cell fate decisions.展开更多
The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun ...The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun to elucidate the molecular cell death machinery in this model organism. Based on ESTs and the whole Hydra genome assembly, we have identified 15 caspases. We show that one is activated during apoptosis, four have characteristics of initiator caspases with N-terminal DED, CARD or DD domain and two undergo autoprocessing in vitro. In addition, we describe seven Bcl-2-1ike and two Bak-like proteins. For most of the Bcl-2 family proteins, we have observed mitochondrial localization. When expressed in mammalian cells, HyBak-like 1 and 2 strongly induced apoptosis. Six of the Bcl-2 family members inhibited apoptosis induced by camptothecin in mammalian ceils with HyBcl-2-1ike 4 showing an especially strong protective effect. This protein also interacted with HyBak-like 1 in a yeast two-hybrid assay. Mutation of the conserved leucine in its BH3 domain abolished both the interaction with HyBak-like 1 and the anti-apoptotic effect. Moreover, we describe novel Hydra BH-3-only proteins. One of these interacted with Bcl-2-1ike 4 and induced apoptosis in mammalian cells. Our data indicate that the evolution of a complex network for cell death regulation arose at the earliest and simplest level of multicellular organization, where it exhibited a substantially higher level of complexity than in the protostome model organisms Caenorhabditis and Drosophila.展开更多
Objectives To investigate the effect of co-exposure of myocardial ischemia and cold stress on myocardial injury in rats and the relative mechanism.Methods Myocardial ischemia model was established by ligation of left ...Objectives To investigate the effect of co-exposure of myocardial ischemia and cold stress on myocardial injury in rats and the relative mechanism.Methods Myocardial ischemia model was established by ligation of left coronary artery.SD rats were randomly allocated to 4 groups; sham+normal temperature(S group),sham+cold stress(SC group),myocardial ischemia+ normal temperature(Ⅰgroup), myocardial ischemia+cold stress(IC group).On the condition of 26℃,SC and IC groups were keeped in a 4℃artificial chamber for 8h(8;00-16:00) for 4 consecu- tive days.Car diac function was assessed by echocardiography;pathological change was analyzed by HE staining;myocardial infarct size was determined by TTC staining;Bim,Caspase-3 expression in myocardium was determined by western blotting.Results It was demonstrated that co-exposure of myocardial ischemia and cold stress could significantly make the cardiac muscle in abnormal shape,increase the infarct size and the expression of Bim and Caspase-3.Conclusions Co-exposure of myocardial ischemia and cold stress may aggravate the cardiac injury,pro- apoptosis protein Bim is involved.展开更多
BH3-only蛋白（bcl-2 homology domain only proteins）是Bcl-2蛋白家族中启动和调节细胞凋亡的重要成员，能识别不同的细胞刺激形式并被活化，其活性受转录和／或翻译后修饰的调节。BH3-only蛋白通过抑制Bcl-2抗凋亡成员的活性或激活Ba...BH3-only蛋白（bcl-2 homology domain only proteins）是Bcl-2蛋白家族中启动和调节细胞凋亡的重要成员，能识别不同的细胞刺激形式并被活化，其活性受转录和／或翻译后修饰的调节。BH3-only蛋白通过抑制Bcl-2抗凋亡成员的活性或激活Bax／Bak样促凋亡成员的活性来调节细胞凋亡，在组织发育、维持内环境稳定、防止自身免疫病和肿瘤的发生中有着极其重要的作用。本文主要就BH3-only蛋白对凋亡的调控研究作一综述。展开更多
文摘Most defective and unwanted cells die by apoptosis, cells without damaging the surrounding tissue. Once a an exquisitely controlled genetic programme for removing such cell has committed to apoptosis, the process is remarkably efficient, and is completed within a few minutes of initiation. This point of no retum for an apoptotic cell is commonly held to be the point at which the outer mitochondrial membrane is permeabilised, a process regulated by the Bcl-2 family of proteins. How these proteins regulate this decision point is central to diseases such as cancer where apoptotic control is lost. In this review, we will discuss apoptotic signalling and how a cell makes the irreversible decision to die. We will focus on one set of survival signals, those derived by cell adhesion to the extracellular matrix （ECM）, and use these to highlight the complexities of apoptotic signalling. In particular, we will illustrate how multiple signalling pathways converge to determine critical cell fate decisions.
文摘The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun to elucidate the molecular cell death machinery in this model organism. Based on ESTs and the whole Hydra genome assembly, we have identified 15 caspases. We show that one is activated during apoptosis, four have characteristics of initiator caspases with N-terminal DED, CARD or DD domain and two undergo autoprocessing in vitro. In addition, we describe seven Bcl-2-1ike and two Bak-like proteins. For most of the Bcl-2 family proteins, we have observed mitochondrial localization. When expressed in mammalian cells, HyBak-like 1 and 2 strongly induced apoptosis. Six of the Bcl-2 family members inhibited apoptosis induced by camptothecin in mammalian ceils with HyBcl-2-1ike 4 showing an especially strong protective effect. This protein also interacted with HyBak-like 1 in a yeast two-hybrid assay. Mutation of the conserved leucine in its BH3 domain abolished both the interaction with HyBak-like 1 and the anti-apoptotic effect. Moreover, we describe novel Hydra BH-3-only proteins. One of these interacted with Bcl-2-1ike 4 and induced apoptosis in mammalian cells. Our data indicate that the evolution of a complex network for cell death regulation arose at the earliest and simplest level of multicellular organization, where it exhibited a substantially higher level of complexity than in the protostome model organisms Caenorhabditis and Drosophila.
文摘Objectives To investigate the effect of co-exposure of myocardial ischemia and cold stress on myocardial injury in rats and the relative mechanism.Methods Myocardial ischemia model was established by ligation of left coronary artery.SD rats were randomly allocated to 4 groups; sham+normal temperature(S group),sham+cold stress(SC group),myocardial ischemia+ normal temperature(Ⅰgroup), myocardial ischemia+cold stress(IC group).On the condition of 26℃,SC and IC groups were keeped in a 4℃artificial chamber for 8h(8;00-16:00) for 4 consecu- tive days.Car diac function was assessed by echocardiography;pathological change was analyzed by HE staining;myocardial infarct size was determined by TTC staining;Bim,Caspase-3 expression in myocardium was determined by western blotting.Results It was demonstrated that co-exposure of myocardial ischemia and cold stress could significantly make the cardiac muscle in abnormal shape,increase the infarct size and the expression of Bim and Caspase-3.Conclusions Co-exposure of myocardial ischemia and cold stress may aggravate the cardiac injury,pro- apoptosis protein Bim is involved.
文摘BH3-only蛋白（bcl-2 homology domain only proteins）是Bcl-2蛋白家族中启动和调节细胞凋亡的重要成员，能识别不同的细胞刺激形式并被活化，其活性受转录和／或翻译后修饰的调节。BH3-only蛋白通过抑制Bcl-2抗凋亡成员的活性或激活Bax／Bak样促凋亡成员的活性来调节细胞凋亡，在组织发育、维持内环境稳定、防止自身免疫病和肿瘤的发生中有着极其重要的作用。本文主要就BH3-only蛋白对凋亡的调控研究作一综述。
