Over-production of nitric oxide is pathogenic for neuronal apoptosis around the ischemic area fol- lowing ischemic brain injury. In this study, an apoptotic model in rat hippocampal neurons was es- tablished by 0.5 mm...Over-production of nitric oxide is pathogenic for neuronal apoptosis around the ischemic area fol- lowing ischemic brain injury. In this study, an apoptotic model in rat hippocampal neurons was es- tablished by 0.5 mmol/L 3-morpholinosyndnomine （SIN-l）, a nitric oxide donor. The models were then cultured with 0.1 mmol/L of 4,4＇-diisothiocyanostilbene-2,2＇-disulfonic acid （DIDS; the chloride channel blocker）for 18 hours. Neuronal survival was detected using the 3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, and apoptosis was assayed by Hoechst 33342-labeled neuronal DNA fluorescence staining. Western blot analysis and immunochemilumi- nescence staining were applied to determine the changes of activated caspase-3 and CIC-3 channel proteins. Real-time PCR was used to detect the mRNA expression of CIC-3. The results showed that SIN-1 reduced the neuronal survival rate, induced neuronal apoptosis, and promoted CIC-3 chloride channel protein and mRNA expression in the apoptotic neurons. DIDS reversed the effect of SIN-I. Our findings indicate that the increased activities of the CIC-3 chloride channel may be involved in hippocampal neuronal apoptosis induced by nitric oxide.展开更多
Transforming growth factor β plays a role in regulation of apoptosis in CIC-3 and the Smads signaling pathway, although the underlying mechanisms remain unclear. The present study determined possible signal transduct...Transforming growth factor β plays a role in regulation of apoptosis in CIC-3 and the Smads signaling pathway, although the underlying mechanisms remain unclear. The present study determined possible signal transduction mechanisms based on CIC-3 expression, which accordingly affected apoptosis of retinal ganglion cells in a glutamate-induced retinal ganglion cell RGC-5 apoptosis model. Results revealed significantly increased cell survival rate and significantly decreased apoptosis rate following apoptosis of CIC-3 cDNA-transfected glutamate-induced retinal ganglion cells. Following inhibition of the CIC-3 chloride channel using RNAi technology, cell survival and apoptosis rates were reversed. In addition, expression of transforming growth factor β2 Smads2, Smads3, Smads4, and Smads7 increased to varying degrees. These results suggest that CIC-3 chloride channel plays a protective role in glutamate-induced apoptosis of retinal ganglion cells, and transforming growth factor β/Smads signal transduction pathways are involved in this process.展开更多
Human spermatozoa encounter an osmotic decrease from 330 to 290 mOsm I-z when passing through the female reproductive tract. We aimed to evaluate the role of chloride channels in volume regulation and sperm motility f...Human spermatozoa encounter an osmotic decrease from 330 to 290 mOsm I-z when passing through the female reproductive tract. We aimed to evaluate the role of chloride channels in volume regulation and sperm motility from patients with asthenozoospermia. Spermatozoa were purified using Percoll density gradients. Sperm volume was measured as the forward scatter signal using flow cytometry. Sperm motility was analyzed using computer-aided sperm analysis （CASA）. When transferred from an isotonic solution （330 mOsm I-z） to a hypotonic solution （290 mOsm I-Z）, cell volume was not changed in spermatozoa from normozoospermic men; but increased in those from asthenozoospermic samples. The addition of the chloride channel blockers, 4,4＇-diisothiocyanatostilbene-2,2＇- isulfonic acid （DIDS） or 5-nitro-2-（3-phenylpropylamino） benzoic acid （NPPB） to the hypotonic solution caused the normal spermatozoa to swell but did not increase the volume of those from the asthenozoospermic semen. DIDS and NPPB decreased sperm motility in both sets of semen samples. The inhibitory effect of NPPB on normal sperm motility was much stronger than on spermatozoa from the asthenozoospermic samples. Both sperm types expressed CIC-3 chloride channels, but the expression levels in the asthenozoospermic samples were much lower, especially in the neck and mid-piece areas. Spermatozoa from men with asthenozoospermia demonstrated lower volume regulating capacity, mobility, and CIC-3 expression levels （especially in the neck） than did normal spermatozoa. Thus, chloride channels play important roles in the regulation of sperm volume and motility and are downregulated in cases of asthenozoospermia.展开更多
基金This work was supported by grants from the Wellcome Trust UK (056909/299/Z) the Education Ministry of China (GJ9901) and the Health Department of Guangdong Province (A2001474).
基金supported by the National Natural Science Foundation of China,No.81160157a grant from Guizhou Science and Technology Department in China,No.SY20093075Technological Talents Funds of Guizhou Province in China,No.201209
文摘Over-production of nitric oxide is pathogenic for neuronal apoptosis around the ischemic area fol- lowing ischemic brain injury. In this study, an apoptotic model in rat hippocampal neurons was es- tablished by 0.5 mmol/L 3-morpholinosyndnomine （SIN-l）, a nitric oxide donor. The models were then cultured with 0.1 mmol/L of 4,4＇-diisothiocyanostilbene-2,2＇-disulfonic acid （DIDS; the chloride channel blocker）for 18 hours. Neuronal survival was detected using the 3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, and apoptosis was assayed by Hoechst 33342-labeled neuronal DNA fluorescence staining. Western blot analysis and immunochemilumi- nescence staining were applied to determine the changes of activated caspase-3 and CIC-3 channel proteins. Real-time PCR was used to detect the mRNA expression of CIC-3. The results showed that SIN-1 reduced the neuronal survival rate, induced neuronal apoptosis, and promoted CIC-3 chloride channel protein and mRNA expression in the apoptotic neurons. DIDS reversed the effect of SIN-I. Our findings indicate that the increased activities of the CIC-3 chloride channel may be involved in hippocampal neuronal apoptosis induced by nitric oxide.
文摘Transforming growth factor β plays a role in regulation of apoptosis in CIC-3 and the Smads signaling pathway, although the underlying mechanisms remain unclear. The present study determined possible signal transduction mechanisms based on CIC-3 expression, which accordingly affected apoptosis of retinal ganglion cells in a glutamate-induced retinal ganglion cell RGC-5 apoptosis model. Results revealed significantly increased cell survival rate and significantly decreased apoptosis rate following apoptosis of CIC-3 cDNA-transfected glutamate-induced retinal ganglion cells. Following inhibition of the CIC-3 chloride channel using RNAi technology, cell survival and apoptosis rates were reversed. In addition, expression of transforming growth factor β2 Smads2, Smads3, Smads4, and Smads7 increased to varying degrees. These results suggest that CIC-3 chloride channel plays a protective role in glutamate-induced apoptosis of retinal ganglion cells, and transforming growth factor β/Smads signal transduction pathways are involved in this process.
文摘Human spermatozoa encounter an osmotic decrease from 330 to 290 mOsm I-z when passing through the female reproductive tract. We aimed to evaluate the role of chloride channels in volume regulation and sperm motility from patients with asthenozoospermia. Spermatozoa were purified using Percoll density gradients. Sperm volume was measured as the forward scatter signal using flow cytometry. Sperm motility was analyzed using computer-aided sperm analysis （CASA）. When transferred from an isotonic solution （330 mOsm I-z） to a hypotonic solution （290 mOsm I-Z）, cell volume was not changed in spermatozoa from normozoospermic men; but increased in those from asthenozoospermic samples. The addition of the chloride channel blockers, 4,4＇-diisothiocyanatostilbene-2,2＇- isulfonic acid （DIDS） or 5-nitro-2-（3-phenylpropylamino） benzoic acid （NPPB） to the hypotonic solution caused the normal spermatozoa to swell but did not increase the volume of those from the asthenozoospermic semen. DIDS and NPPB decreased sperm motility in both sets of semen samples. The inhibitory effect of NPPB on normal sperm motility was much stronger than on spermatozoa from the asthenozoospermic samples. Both sperm types expressed CIC-3 chloride channels, but the expression levels in the asthenozoospermic samples were much lower, especially in the neck and mid-piece areas. Spermatozoa from men with asthenozoospermia demonstrated lower volume regulating capacity, mobility, and CIC-3 expression levels （especially in the neck） than did normal spermatozoa. Thus, chloride channels play important roles in the regulation of sperm volume and motility and are downregulated in cases of asthenozoospermia.
