Proper cell-cell and cell-matrix contacts mediated by integrin adhesion receptors are important for development, immune response, hemostasis and wound healing. Integrins pass trans-membrane signals bidirectionally thr...Proper cell-cell and cell-matrix contacts mediated by integrin adhesion receptors are important for development, immune response, hemostasis and wound healing. Integrins pass trans-membrane signals bidirectionally through their regulated affinities for extracellular ligands and intracellular signaling molecules. Such bidirectional signaling by integrins is enabled by the conformational changes that are often linked among extracellular, transmembrane and cytoplasmic domains. Here, we review how talin-integrin and kindlin-integrin interactions, in cooperation with talin-lipid and kindlin-lipid interactions, regulate integrin affinities and how the progress in these areas helps us understand integrin-related diseases.展开更多
AIM: To investigate the effects of prednisolone on cell membrane bleb formation, calpain μ activation and talin degradation during hepatic ischemia-reperfusion injury in rats. METHODS: The hilar area of the left late...AIM: To investigate the effects of prednisolone on cell membrane bleb formation, calpain μ activation and talin degradation during hepatic ischemia-reperfusion injury in rats. METHODS: The hilar area of the left lateral and median lobes of rat liver (68%) was clamped for 60 min and followed by 120 min reperfusion. Prednisolone was administered at 1.0, 3.0, or 10 mg/kg at 30 min before ischemia. In addition to biochemical and microscopic analyses, activation of calpain μ was determined using specific antibodies against the intermediate (activated) form of calpain μ. Degradation of talin was also studied by Western blotting. RESULTS: In the control and prednisolone (1.0 mg/kg) groups, serum aspartate transaminase (AST) and alanine transaminase (ALT) level were elevated, and cell membrane bleb formation was observed after 120 min of reperfusion. Moreover, calpain μ activation and talin degradation were detected. Infusion of prednisolone at 3.0 or 10 mg/kg significantly suppressed serum AST and ALT, and prevented cell membrane bleb formation. At 10 mg/kg, prednisolone markedly suppressed calpain μ activation and talin degradation. CONCLUSION: Prednisolone can suppress ischemia- reperfusion injury of the rat liver. Its cytoprotective effect is closely associated with the suppression of calpain μ activation and talin degradation.展开更多
Green fluorescent protein (GFP) fused to the F_actin binding domain of mouse talin labels the actin cytoskeleton in the immature pollen of stable transformed rice (Oryza sativa L.) plants. Actin microfilaments could b...Green fluorescent protein (GFP) fused to the F_actin binding domain of mouse talin labels the actin cytoskeleton in the immature pollen of stable transformed rice (Oryza sativa L.) plants. Actin microfilaments could be visualized only in the late_developmental stage of the immature pollen. During this developmental stage, microfilaments, initially composed of very short fibrils, develop into a very complex and novel network that sometimes totally and sometimes partially encloses the vegetative nucleus and the spherical shaped generative cell in the central cytoplasm of the immature pollen. The behavior of the actin microfilamentous structure throughout the late_developmental stage of the immature pollen is extremely dynamic, and the likelihood of this structure in generating forces for vegetative nucleus and generative cell movement in the immature pollen has been discussed. No actin filaments were visualized in the spherical generative cells.展开更多
文摘Proper cell-cell and cell-matrix contacts mediated by integrin adhesion receptors are important for development, immune response, hemostasis and wound healing. Integrins pass trans-membrane signals bidirectionally through their regulated affinities for extracellular ligands and intracellular signaling molecules. Such bidirectional signaling by integrins is enabled by the conformational changes that are often linked among extracellular, transmembrane and cytoplasmic domains. Here, we review how talin-integrin and kindlin-integrin interactions, in cooperation with talin-lipid and kindlin-lipid interactions, regulate integrin affinities and how the progress in these areas helps us understand integrin-related diseases.
文摘AIM: To investigate the effects of prednisolone on cell membrane bleb formation, calpain μ activation and talin degradation during hepatic ischemia-reperfusion injury in rats. METHODS: The hilar area of the left lateral and median lobes of rat liver (68%) was clamped for 60 min and followed by 120 min reperfusion. Prednisolone was administered at 1.0, 3.0, or 10 mg/kg at 30 min before ischemia. In addition to biochemical and microscopic analyses, activation of calpain μ was determined using specific antibodies against the intermediate (activated) form of calpain μ. Degradation of talin was also studied by Western blotting. RESULTS: In the control and prednisolone (1.0 mg/kg) groups, serum aspartate transaminase (AST) and alanine transaminase (ALT) level were elevated, and cell membrane bleb formation was observed after 120 min of reperfusion. Moreover, calpain μ activation and talin degradation were detected. Infusion of prednisolone at 3.0 or 10 mg/kg significantly suppressed serum AST and ALT, and prevented cell membrane bleb formation. At 10 mg/kg, prednisolone markedly suppressed calpain μ activation and talin degradation. CONCLUSION: Prednisolone can suppress ischemia- reperfusion injury of the rat liver. Its cytoprotective effect is closely associated with the suppression of calpain μ activation and talin degradation.
文摘Green fluorescent protein (GFP) fused to the F_actin binding domain of mouse talin labels the actin cytoskeleton in the immature pollen of stable transformed rice (Oryza sativa L.) plants. Actin microfilaments could be visualized only in the late_developmental stage of the immature pollen. During this developmental stage, microfilaments, initially composed of very short fibrils, develop into a very complex and novel network that sometimes totally and sometimes partially encloses the vegetative nucleus and the spherical shaped generative cell in the central cytoplasm of the immature pollen. The behavior of the actin microfilamentous structure throughout the late_developmental stage of the immature pollen is extremely dynamic, and the likelihood of this structure in generating forces for vegetative nucleus and generative cell movement in the immature pollen has been discussed. No actin filaments were visualized in the spherical generative cells.
