ABSTRACT
ObjectiveTo investigate the effect and mechanism of modified Shuyuwan （SYW） on hippocampal myelin sheath injury in vascular dementia （VD） model rats. MethodSixty male SD rats of SPF grade were randomly divided into sham operation group， model group， and high-， medium- and low-dose modified SYW groups， with 12 rats in each group. The VD model was induced by bilateral carotid artery ligation in rats of the groups except for those of the sham operation group. After modeling， rats were screened by the water maze test， followed by drug treatment by gavage. Specifically， rats in the modified SYW groups were treated with modified SYW at 10， 5， 2.5 g·kg-1·d-1， accordingly， and those in other groups were administered with the same amount of normal saline. After intragastric administration for 28 days， the spatial learning and memory abilities of rats were detected by the water maze test. The hippocampal neuron structure was observed by hematoxylin-eosin （HE） staining. The content of hippocampal tumor necrosis factor （TNF）-α， interleukin-6 （IL-6）， and glutamate （Glu） was observed by biochemical detection. The hippocampal expression of myelin basic protein （MBP）， astrocyte activation marker glial fibrillary acidic protein （GFAP）， and connexin 43 （Cx43） was detected by immunofluorescence detection. The myelin sheath structure in the hippocampus was observed by the electron microscope. The α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor （AMPAR） and Cx43 protein expression was detected by Western blot. ResultCompared with the sham operation group， the model group showed prolonged escape latency （P<0.01）， decreased times of crossing the original platform and percentage of target quadrant detention time （P<0.01）， disordered neuron structure in the hippocampal CA1 region， loose myelin sheath lamella with blurry edge， up-regulated expression levels of TNF-α， IL-6， and Glu in the hippocampal CA1 region， especially Glu （P<0.01）， reduced expression of AMPAR （P<0.01）， increased protein expression of p-AMPAR and Cx43 （P<0.01）， significantly dwindled protein expression of MBP in the myelin sheath， and enhanced fluorescence co-labeled by GFAP and Cx43. Compared with the model group， the modified SYW groups showed shortened escape latency （P<0.05）， increased times of crossing the original platform and percentage of target quadrant detention time （P<0.05）， closely arranged hippocampal neuron structure， denser myelin sheath lamella with clear edge， down-regulated expression levels of TNF-α， IL-6， and Glu in the hippocampal CA1 region， especially Glu （P<0.01）， up-regulated AMPAR （P<0.01）， reduced protein expression of p-AMPAR and Cx43， especially in the high-dose group （P<0.01）， significantly elevated protein expression of MBP in the myelin sheath， and weakened fluorescence co-labeled by GFAP and Cx43， especially in the high-dose group. ConclusionModified SYW can improve the learning and memory abilities of VD rats， and the mechanism may be related to the inhibition of Cx43 expression， reduction of the release of Glu， inhibition of AMPAR-mediated inflammatory response to reduce the production of astrocyte marker GFAP， and promotion of the expression of MBP protein to alleviate myelin injury.
ABSTRACT
<b>Objective::To investigate the mechanism of Buyang Huanwu Tang (BYHWT) in improving synaptic structural plasticity after cerebral ischemia-reperfusion in rats. <b>Method::Middle cerebral artery occlusion and reperfusion model was established. SD rats were randomly divided into sham-operated group, model group, BYHWT group, BYHWT+ Gap26(connexin43 inhibitor)groups. BYHWT was given twice a day(16 g·kg<sup>-1</sup>), Gap26 was intraperitoneally injected once a day since the third day after surgery (25 g·kg<sup>-1</sup>). Brain was taken out at the 7<sup>th</sup> day. The changes of neuronal synaptic and gap junction ultrastructure were observed by transmission electron microscopy. Synaptophysin (SYN) and growth-associated protein-43 (GAP-43) protein expression were detected by Western blot and immunofluorescence. <b>Result::The structure of synapses was integrated, and the gap junctions were clear in sham-operated group. In the hippocampus of model group, the structure was destroyed, and the gap junctions disappeared. Compared with the sham-operated group, model group up-regulated the expressions of SYN and GAP-43 (<italic>P</italic><0.05, <italic>P</italic><0.01). In the hippocampus of BYHWT group, the structure was close to the normal. Furthermore, BYHWT up-regulated the expressions of SYN and GAP-43 (<italic>P</italic><0.05, <italic>P</italic><0.01). However, after the combined administration with Cx43 inhibitor (Gap26), the damage of synaptic structural decreased, only a small number of gap junctions with the structural integrity can be seen, and the effect of BYHWT on SYN and GAP-43 was inhibited (<italic>P</italic><0.05, <italic>P</italic><0.01). <b>Conclusion::BYHWT could improve the hippocampal synaptic structural plasticity obviously after the CIRI. The mechanism may be related to the increase of the expression of Cx43 and the promotion of the intervention of SYN and GAP-43.
ABSTRACT
Objective:To investigate Cx43 expression and gap junctional intercellular communication(GJIC) in ectopic and eutopic endometrial stromal cells in endometriosis(EMs),and to explore the influence of aberrant GJIC in stromal cells on pathogenesis of EMs. Methods:The stromal cells were isolated from samples including 24 ectopic endometriotic tissues located in ovaries,41 eutopic endometria with endometriosis and 30 normal endometria. The endometrial stromal cells models were established in vitro by being cultured in manual conditions mimicked with estrogen and progesterone. Laser scanning confocal microscopy(LSCM) was used to determine the expression of Cx43 protein and the function of GJIC in three groups stromal cells. Results:The success rate of isolation and culture of endometriotic stromal cells was 45.8%(11/24);of eutopic endometrial stromal cells with EMs was 92.7(38/41);of normal endometrial stromal cells was 93.3%(28/30). The purities of ectopic and eutopic endometrial stromal cells were 95% and 98% respectively. The level of Cx43 protein and the function of GJIC in stromal cells from ectopic endometrial tissues were much lower than those from the other two groups,the highest level of Cx43 protein and the function of GJIC were observed in normal endometrial stromal cells group,and the differences among these groups were significant (P﹤0.01). Conclusions:(1) It will be helpful to establish models of normal,ectopic and eutopic endometrial stromal cells in vitro simultaneously when investigating the pathgenesis of EMs. (2)Downregulation of Cx43 expression and aberrant function of GJIC are related to pathogenesis of EMs. Regulation of Cx43 or GJIC in endometrial stromal cells is implied to be a potential strategy to treat EMs.
ABSTRACT
Objective To investigate the differences of connexin 43(Cx43)expression between adult and infant heart. Methods By using immunohistochemistry to observe the expression of Cx43. Results 1.The expression of Cx43 had a punclate distribution in cytoplasm and over the entire surface of the cardiocyte,and a few located at intercalated disk of atrial and ventricular myocardium in the infant heart.2.Cx43 positive granules distributed irregularly in cell side surface and cytoplasm as well as intercalated disk in adult atrium.Cx43 immunolabelling of adult ventricular myocardium was typically confined to the site of intercalated disk.3.The results of image analyzer showed that the amount of connexin43 expression was lower in the atrium than that of the ventricle in infant heart and atrium bigger than ventricle in adult heart.The expression of Cx43 was less in adult heart than that of infant heart.Conclusion The expression of Cx43 was mainly over the entire surface of the myocardium in infant heart.There were expression differences of Cx43 in human ventricular and atrial myocytes.The amount of Cx43 expression was higher in ventricle than that of atrium in infant heart and atrium bigger than ventricle in adult heart.It was less in adult heart than that of infant.It showed that the expression of Cx43 in human heart existed a developmental differences.
ABSTRACT
Objective To study the expression of connexin 43 in human cardiac conduction system(CCS) and heart. Methods The distribution of CX43 was studied immunohistochemically using of SABC method with antibody CX43. Results Smaller amounts of CX43 can be seen in the nodal myocytes at the periphery of sinoaterial and atrioventricular node whereas in the myocytes at the center of nodes were negative. In the Purkinje fibers, abundant expression of CX43 was found, and in atrial and ventricular myocardium contained abundant amounts of CX43, especially in the intercatalated disk.Conclusion The expression of connexin 43 varies greatly in specific regions of the human heart with different conduction properties. These differences may play a role in regulating electric impulse of cardiac conduction.