Corticotropin-releasing factor(CRF),which activates the hypothalamic-pituitary-adrenal axis under stress,also has proinflammatory peripheral effects possibly through mast cells.The purpose of this study was to investi...Corticotropin-releasing factor(CRF),which activates the hypothalamic-pituitary-adrenal axis under stress,also has proinflammatory peripheral effects possibly through mast cells.The purpose of this study was to investigate the effect of urocortin(UCN),a 40-amino-acid CRF family peptide,on degranulation and intracellular calcium of rat lung mast cells.The activation and degranulation of mast cells were observed by Toluidine blue staining and transmission electron microscope.The intracellular calcium was investigated using confocal laser scanning microscopy and flow cytometry.The results indicated that all the three different concentrations of UCN(0.1,1 and 10 mu M)significantly induced the activation and degranulation of rat lung mast cells in vitro.This effect was markedly blocked by selective CRF receptor 1(CRF-R1)antagonist antalarmin,but not by specific CRF receptor 2(CRF-R2)antagonist antisauvagine-30(anti-Svg-30).The results also showed that UCN caused a rapid peak increase inCa2+(i)at point of 300s after UCN treatment,followed by a decrease to a sustained plateau phase.The peak increase inCa2+(i)induced by UCN was significantly inhibited by antalarmin,but not by anti-Svg-30.This effect of UCN onCa2+(i)in rat lung mast cells was also found by flow cytometry.Regression analysis revealed a positive correlation between mast cells degranulation extent and the maximum value ofCa2+(i)(P<0.01).Taken together,our present study suggested that UCN induced the increase of Ca2+(i)and degranulation of rat lung mast cells through CRF-R1.These findings may have implications for the pathophysiology of allergic and inflammatory lung disorders such as asthma,which is closely associated with mast cell activation and degranulation.Copyright(c)2008 S.Karger AG,Basel.展开更多
Osteocytes in vivo are embedded in the mineralized extracellular bone matrix,where their cell bodies reside in the lacunae and are interconnected to neighboring osteocytes through numerous intercellular processes.The ...Osteocytes in vivo are embedded in the mineralized extracellular bone matrix,where their cell bodies reside in the lacunae and are interconnected to neighboring osteocytes through numerous intercellular processes.The 3-dimensional（3D）osteocyte network positioning and ability to communicate with other bone cells make osteocytes ideal mechanosensors of bone.Thus the role of osteocyte network and intercellular communication between osteocytes in response to mechanical stimulation may clarify the mechanisms behind normal bone adaptation to mechanical loading.We have been using intracellular calcium([Ca<sup>2+</sup>]<sub>i</sub>)as a ubiquitous real-time signaling indicator for studying mechanotransduction in osteocytic network展开更多
Objectives: To construct retroviral vectorsexpressing antisense polymeric RNAs targeted at the coresequence (+13-+47) of HIV-l TAR RNA, and to testthe anti-HIV properties of this construct in transducedCD4^+T cells. M...Objectives: To construct retroviral vectorsexpressing antisense polymeric RNAs targeted at the coresequence (+13-+47) of HIV-l TAR RNA, and to testthe anti-HIV properties of this construct in transducedCD4^+T cells. Methods: The polymeric TAR-Core DNAwas amplified by the"self-primers-template PCR"展开更多
文摘Corticotropin-releasing factor(CRF),which activates the hypothalamic-pituitary-adrenal axis under stress,also has proinflammatory peripheral effects possibly through mast cells.The purpose of this study was to investigate the effect of urocortin(UCN),a 40-amino-acid CRF family peptide,on degranulation and intracellular calcium of rat lung mast cells.The activation and degranulation of mast cells were observed by Toluidine blue staining and transmission electron microscope.The intracellular calcium was investigated using confocal laser scanning microscopy and flow cytometry.The results indicated that all the three different concentrations of UCN(0.1,1 and 10 mu M)significantly induced the activation and degranulation of rat lung mast cells in vitro.This effect was markedly blocked by selective CRF receptor 1(CRF-R1)antagonist antalarmin,but not by specific CRF receptor 2(CRF-R2)antagonist antisauvagine-30(anti-Svg-30).The results also showed that UCN caused a rapid peak increase inCa2+(i)at point of 300s after UCN treatment,followed by a decrease to a sustained plateau phase.The peak increase inCa2+(i)induced by UCN was significantly inhibited by antalarmin,but not by anti-Svg-30.This effect of UCN onCa2+(i)in rat lung mast cells was also found by flow cytometry.Regression analysis revealed a positive correlation between mast cells degranulation extent and the maximum value ofCa2+(i)(P<0.01).Taken together,our present study suggested that UCN induced the increase of Ca2+(i)and degranulation of rat lung mast cells through CRF-R1.These findings may have implications for the pathophysiology of allergic and inflammatory lung disorders such as asthma,which is closely associated with mast cell activation and degranulation.Copyright(c)2008 S.Karger AG,Basel.
基金supported by the US National Institutes of Health grants R21 AR052417,R01 AR052461,RC1 AR058453(XEG),and R01 AR054385(LW)
文摘Osteocytes in vivo are embedded in the mineralized extracellular bone matrix,where their cell bodies reside in the lacunae and are interconnected to neighboring osteocytes through numerous intercellular processes.The 3-dimensional（3D）osteocyte network positioning and ability to communicate with other bone cells make osteocytes ideal mechanosensors of bone.Thus the role of osteocyte network and intercellular communication between osteocytes in response to mechanical stimulation may clarify the mechanisms behind normal bone adaptation to mechanical loading.We have been using intracellular calcium([Ca<sup>2+</sup>]<sub>i</sub>)as a ubiquitous real-time signaling indicator for studying mechanotransduction in osteocytic network
文摘Objectives: To construct retroviral vectorsexpressing antisense polymeric RNAs targeted at the coresequence (+13-+47) of HIV-l TAR RNA, and to testthe anti-HIV properties of this construct in transducedCD4^+T cells. Methods: The polymeric TAR-Core DNAwas amplified by the"self-primers-template PCR"
