Effects Of Gastric Electrical Stimulation On Phenotype Of ICC And Synaptic Plasticity Of ICC-ENS

Aims: The aims of this study were to observe changes of phenotype of ICC in diabetic rats induced by STZ.Methods: 36 diabetic rats and 18 controls were used in this study, which were sacrificed at the time point 2, 4, 6, 8, 10 and 12 weeks after injection of STZ or citric acid buffer. The morphology of ICC was observed by electron microscopy and double staining of immunohistochemistry with antibodies for c-kit and muscle-specific filament proteins; Occurrence of apoptosis was also assayed by TUNEL; RT-PCR and Western blot were used to confirm the expressions of mRNA and protein for c-kit and muscle-specific filament proteins.Results: 1)Kit and desmin or smooth muscle myosin are isolated in controls but colocalized in diabetic rats. Kit andα-SMA immunoreactivities were not colocalized in both controls and diabetic rats. 2)Remaining Kit-immunopositive cells in myenteric region developed ultrastructural features similar to smooth muscle cells, including prominent filament bundles and expression of the muscle-specific intermediate filament protein desmin, and smooth muscle myosin. 3)Apoptosis was not detected in myenteric region. 4)Decreasing in mRNA and protein expressions of c-kit and increasing in mRNA and protein expressions of desmin and smooth muscle myosin heavy and light chain were detected.Conclusions: These data suggested inherent plasticity between the ICC and smooth muscle cells in diabetic rats induced by STZ. Aims: To observe changes of SCF/KIT signaling in diabetic rats induced by STZ and to study their roles in phenotype plasticity of ICC.Methods: 36 diabetic rats induced by STZ and 18 controls were used in this study, which were sacrificed at the time point 2, 4,6,8,10 and 12 weeks after injection of STZ or citric acid buffer. The concentrations of soluble SCF (S-SCF) in serum were detected by ELISA. The expressions of mRNA and protein for membrane-bound SCF (M-SCF) were analyzed by RT-PCR and Western blot.Results: Comparing with control group, the concentrations of S-SCF (2wk vs 6wk vs 12wk: 278.63±37.28 vs 263.92±30.74 vs 228.05±41.56 pg/ml, P<0.01) , expressions of M-SCF mRNA (2wk vs 6wk vs 12wk: 0.74±0.11 vs 0.63±0.12 vs 0.34±0.09, P<0.01) and protein levels (2wk vs 6wk vs 12wk: 0.43±0.08 vs 0.31±0.06 vs 0.16±0.05, P<0.05) in diabetic group decreased significantly with course of diabetes. S-SCF and M-SCF were correlative with c-kit mRNA and protein expressions.Conclusions: The concentrations of S-SCF and expressions of M-SCF mRNA and protein of diabetic group decreased significantly with course of diabetes, both of them were crucial in maintaining phenotype of ICC. Aims: To observe changes of synapse of ICC-ENS in diabetic rats induced by STZ.Methods: 36 diabetic rats and 18 controls were used in this study, which were sacrificed at the time point 2, 4, 6, 8, 10 and 12 weeks after injection of STZ or citric acid buffer. The morphology of synapse of ICC-ENS was observed by electron microscopy and immunohistochemistry for synaptophysin antibody; RT-PCR and Western blot were used to confirm the expressions of mRNA and protein for synaptophysin.Results: In ultrastructure, nerve fibers were incompact and synaptic vesicle were reduced; Comparing with control group, remaining synaptophysin- immunopositive cells reduced; Synaptophysin mRNA levels (2wk vs 6wk vs 12wk: 0.52±0.13vs 0.39±0.10 vs 0.21±0.05, P<0.01) and protein levels (2wk vs 6wk vs 12wk: 0.41±0.13 vs 0.29±0.09 vs 0.14±0.03, P<0.05) in diabetic group decreased significantly with course of diabetes.Conclusions: Synaptic vesicle and synaptophysin-immunopositive cells were reduced in myenteric region of diabetic group. synaptophysin mRNA and protein expressure of diabetic group decreased significantly with course of diabetes. Aims: To observe whether long-pulse gastric electrical stimulation could remodel the phenotype of ICC in diabetic rats induced by STZ.Methods: 32 rats implanted with 2 pairs of electrodes on gastric serosa were studied, which were divided into four groups. Two acute long-pulse GES groups began from the 4th or 6th week of diabetic course and two chronic long-pulse GES groups continued for four or six weeks from the beginning of diabetic course. The morphology of ICC was observed by electron microscopy and double staining of immunohistochemistry with antibodies for c-kit and muscle-specific filament proteins; RT-PCR and Western blot were used to compare the changes expressions of mRNA and protein for c-kit and muscle-specific filament proteins.Results: 1) In ultrastructure, the number of hybrid cells increased after chronic long-pulse GES for 4 weeks. These cells had darkly stained cytoplasm and areas rich in microfilaments and intermediate filamentssynaptic. 2)The cells double-labeling by both c-kit-immunopositive and desmin-immunopositive or SMHC-immunopositive increased after chronic long-pulse GES for 4 weeks. 3) Expression of c-kit mRNA could be up-regulated and expressions of desmin , SMHC and SMLC mRNA could be down-regulated by chronic long-pulse GES for 4 weeks. But there were no significant effects on expression of c-kit, desmin,SMHC and SMLC mRNA after the 4th and 6th week acute GES or chronic GES for 6 weeks. There wasn't significant deference in the expression ofα-SMA mRNA before and after GES. 4) Expression of c-kit protein could be up-regulated and expressions of desmin,SMHC protein could be down-regulated by chronic long-pulse GES for 4 weeks. But there were no significant effects on expression of c-kit, desmin and SMHC protein after the 4th and 6th week acute GES or chronic GES for 6 weeks. There wasn't significant deference in the expression ofα-SMA and SMLC protein before and after GES.Conclusions: These data showed chronic long-pulse GES for 4 weeks could remodel ICC in diabetic rats induced by STZ. Aims: The study is to observe whether long-pulse gastric electrical stimulation could remodel synapse of ICC-ENS in diabetic rats induced by STZ.Methods: 32 rats implanted with 2 pairs of electrodes on gastric serosa were studied, which were divided into four groups. Two acute long-pulse GES groups began from the 4th or 6th week of diabetic course and two chronic long-pulse GES groups continued for four or six weeks from the beginning of diabetic course. The morphology of synapse of ICC-ENS was observed by electron microscopy and immunohistochemistry for synaptophysin antibody; RT-PCR and Western blot were used to confirm the expressions of mRNA and protein for synaptophysin.Results: 1) In ultrastructure, the number of synaptic vesicle increased after acute and chronic long-pulse GES. 2)Synaptophysin-immunopositive cells increased after acute and chronic long-pulse GES. 3) Expression of Synaptophysin mRNA could be up-regulated by acute GES beginning from the 4th (0.46±0.11 vs 0.57±0.09, P<0.05) and the 6th week (0.39±0.10 vs 0.49±0.12, P<0.05) and it could also be up-regulated by chronic GES both for 4 weeks (0.46±0.11 vs 0.66±0.09, P<0.01) and 6 weeks (0.39±0.10 vs 0.58±0.11, P<0.05). There wasn't significant deference between the effect of GES from the 4th week and from the 6th week (0.57±0.09 vs 0.49±0.12, P >0.05) , no significant deference was between chronic GES for 4 weeks and 6 weeks (0.66±0.09 vs 0.58±0.11, P >0.05), and no significant deference was between acute GES groups and chronic GES groups. 4) Expression of Synaptophysin protein could be up-regulated by acute GES beginning from the 4th (0.35±0.13 vs 0.50±0.11,P<0.05) and the 6th week (0.29±0.09 vs 0.37±0.09, P<0.05) and it could also be up-regulated by chronic GES both for 4 weeks (0.35±0.13 vs 0.64±0.10,P<0.01) and 6 weeks (0.29±0.09 vs 0.51±0.10,P<0.01). The effect of GES from the 4th week was more significant than that from the 6th week (0.50±0.11 vs 0.37±0.09,P<0.05) and the effect was more significant in chronic GES for 4 weeks than for 6 weeks (0.64±0.10 vs 0.51±0.10,P<0.05).Conclusions: Long-pulse gastric electrical stimulation may remodel synapse of ICC-ENS, and maybe chronic GES in the early couse of diabetes was more efficient. Aims: To observe effects of long-pulse gastric electrical stimulation on SCF/KIT signaling in STZ induced diabetic rats and to study their roles in remodeling ICC.Methods: 32 rats implanted with 2 pairs of electrodes on gastric serosa were studied, which were divided into four groups randomly. Two acute long-pulse GES groups began from the 4th or 6th week of diabetic course and two chronic long-pulse GES groups continued for four or six weeks from the beginning of diabetic course. The concentrations of soluble SCF (S-SCF) in serum were detected by ELISA. The expressions of mRNA and protein for membrane-bound SCF (M-SCF) were analyzed by RT-PCR and Western blot.Results: 1)There was no significant effect on concentrations of S-SCF with acute and chronic long-pulse GES. 2) Expression of M-SCF mRNA could be up-regulated by acute GES beginning from not the 6th (0.63±0.12 vs 0.66±0.07, P>0.05) but the 4th week (0.65±0.14. vs 0.76±0.09, P<0.05), and it could also be up-regulated by chronic GES both for 4 weeks (0.65±0.14. vs 0.80±0.12, P<0.05) and 6 weeks (0.63±0.12 vs 0.70±0.11, P<0.05). The effect of GES from the 4th week was more significant than that from the 6th week(0.76±0.09 vs 0.66±0.07, P<0.05), and the effect was more significant for 4 weeks'than 6 weeks'chronic GES (0.80±0.12 vs 0.70±0.11, P<0.05) . 3) Expression of M-SCF protein could be up-regulated by acute GES beginning from not the 6th (0.31±0.06 vs 0.33±0.10, P>0.05) but the 4th week (0.34±0.09 vs 0.56±0.12,P<0.05) and it could also be up-regulated by chronic GES both for 4 weeks (0.34±0.09 vs 0.64±0.09,P<0.01) and 6 weeks (0.31±0.06 vs 0.47±0.10,P<0.05). The effect of GES from the 4th week was more significant than that from the 6th week (0.56±0.12 vs 0.33±0.10,P<0.01) and the effect was more significant in chronic GES for 4 weeks than for 6 weeks (0.64±0.09 vs 0.47±0.10,P<0.05) .Conclusions: Long-pulse gastric electrical stimulation may remodel ICC by up-regulating the mRNA and protein expressions of M-SCF, and chronic GES and early in the couse of diabetes was more efficient.