Insulin signal is one of the vital signaling cascade required for Schwann cells to myelinate the axons of peripheral nervous system(PNS).Myelin formation of peripheral nerve is a complex molecular event controlled by ...Insulin signal is one of the vital signaling cascade required for Schwann cells to myelinate the axons of peripheral nervous system(PNS).Myelin formation of peripheral nerve is a complex molecular event controlled by different neurotrophic and transcription factors.The altered or failure in this signaling progression is one of the reasons behind the demyelination of peripheral neurons in diabetic peripheral neuropathy(DPN).The Schwann cell in PNS includes POU domain transcription factor OCT-6 expression.This factor is considered as crucial for the initiation and enhancement of myelination during nerve regeneration.To know the importance of OCT-6 gene,here we studied the long term expression of OCT-6 nuclear protein in sciatic nerve of normal and diabetic neuropathic rats.Also for the first time we elucidated the role of insulin in controlling the expression of OCT-6 in hyperglycemic Schwann cells and sciatic nerve of diabetic neuropathic rats.The results shows that,there will be long term OCT-6 expression in sciatic nerve of adult rats and also their significant decrease is observed in the diabetic condition.But,addition of Insulin for primary Schwann cells and diabetic rats shows the increased OCT-6 expression in both in vivo and in vitro.Together these results indicate the failure of OCT-6 support in neuropathy and also the importance of insulin signaling cascade in the expression of OCT-6 transcription factor.展开更多
Nanog protein is expressed in the interior cells of compacted morulae and maintained till epiblasts but downregulated by implantation stage. It is also expressed in embryonic stem cells, embryonic carcinoma cells and ...Nanog protein is expressed in the interior cells of compacted morulae and maintained till epiblasts but downregulated by implantation stage. It is also expressed in embryonic stem cells, embryonic carcinoma cells and embryonic germ cells but disappeared in differentiated ES cells. In this study, we have isolated, sequenced, and performed the first characterization of the Nanog promoter. The transcription start sites were mapped by primer extension analysis. Two promoter regions were found upstream the transcription start sites and the expression of major Nanog promoter/ reporter gene construct is abolished in differentiated F9 EC cells as compared to the undifferentiated counterpart. We also showed that a putative octamer motif (ATGCAAAA) is necessary for the major promoter activity. Gel shift and supershift assays showed that Oct-1, Oct-4 and Oct-6 protein selectively bind to the octamer motif.展开更多
A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NM...A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4′-dichloro-5,5′-dibromo-7,7′-dimethoxy-2,2′-bi-1H-indole and 1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′- trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.展开更多
基金This work was supported by grant(SERB No:SB/SO/AS-119/2012)from Science and Engineering Research Board(SERB),Department of Science and Technology(DST),Government of India(New Delhi)MSM was supported by Junior Research Fellowship by DST.
文摘Insulin signal is one of the vital signaling cascade required for Schwann cells to myelinate the axons of peripheral nervous system(PNS).Myelin formation of peripheral nerve is a complex molecular event controlled by different neurotrophic and transcription factors.The altered or failure in this signaling progression is one of the reasons behind the demyelination of peripheral neurons in diabetic peripheral neuropathy(DPN).The Schwann cell in PNS includes POU domain transcription factor OCT-6 expression.This factor is considered as crucial for the initiation and enhancement of myelination during nerve regeneration.To know the importance of OCT-6 gene,here we studied the long term expression of OCT-6 nuclear protein in sciatic nerve of normal and diabetic neuropathic rats.Also for the first time we elucidated the role of insulin in controlling the expression of OCT-6 in hyperglycemic Schwann cells and sciatic nerve of diabetic neuropathic rats.The results shows that,there will be long term OCT-6 expression in sciatic nerve of adult rats and also their significant decrease is observed in the diabetic condition.But,addition of Insulin for primary Schwann cells and diabetic rats shows the increased OCT-6 expression in both in vivo and in vitro.Together these results indicate the failure of OCT-6 support in neuropathy and also the importance of insulin signaling cascade in the expression of OCT-6 transcription factor.
文摘Nanog protein is expressed in the interior cells of compacted morulae and maintained till epiblasts but downregulated by implantation stage. It is also expressed in embryonic stem cells, embryonic carcinoma cells and embryonic germ cells but disappeared in differentiated ES cells. In this study, we have isolated, sequenced, and performed the first characterization of the Nanog promoter. The transcription start sites were mapped by primer extension analysis. Two promoter regions were found upstream the transcription start sites and the expression of major Nanog promoter/ reporter gene construct is abolished in differentiated F9 EC cells as compared to the undifferentiated counterpart. We also showed that a putative octamer motif (ATGCAAAA) is necessary for the major promoter activity. Gel shift and supershift assays showed that Oct-1, Oct-4 and Oct-6 protein selectively bind to the octamer motif.
基金supported by national 863 project(Grant No.2004AA625030,2001AA620503)NNSFC(Grant No.20432030)Key Innovative Project of the Academy(Grant No.KZCX3-SW-215).
文摘A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4′-dichloro-5,5′-dibromo-7,7′-dimethoxy-2,2′-bi-1H-indole and 1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′- trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.
