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Objective To study the effect and mechanism of endoplamic reticulum stress on the auditory cortex injury after focal cerebral ischemia-reperfusion injury in rats.Methods 30 healthy male adult SD rats were chosen and randomly divided into 2 groups,ischemia-reperfusion(I/R) group and sham operated control,with each group 15 rats.The rats in I/R group were operated for suture-occluded method to establish middle cerebral artery occlusionmodel(MCAO),with ischemia for 60 mins followed by reperfusion for 24 h.And the control group was only to be isolated cervical vessels,with no thread embolism inserted.The auditory brainstem response (ABR) was tested before operation and at 24 h post-operation respectively.The neurological deficits,ratio of infarct volume were evaluated.The pathological changes were observed by HE.Neurocyte apoptosis were observed by Tunel,and the AI were determined.The expression of GRP78,Caspase-12 were detected by immunohistochemistry and Western blotting.Results Compared with the sham group,the neurological function scores,the infarct volume of brain of I/R group increased significantly.The threshold of ABR elevated significantly and AI rised in I/R group.HE staining showed that the neurons in the sham group were arranged in order,the shape was normal,but in the I/R group the normal structure disappeared,the nuclei were condensed.The expression of GRP78,Caspase-12 protein were significantly up-regulated.All of the differences above have statistical significance(P＜0.05).Conclusion The mechanism of hearing loss after focal cerebral ischemia-reperfusion injury in rats is perhaps related to endoplamic reticulum stress,and GRP78,Caspase-12 participate in the process of neuron apoptosis on auditory cortex caused by ERS.
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Objective To study the mechanism of endoplamic reticulum stress(ERS)pretreatment induced by 2-DG on the auditory cortex injury after focal cerebral ischemia-reperfusion injury in rats. Methods The SD rats were randomly divided into 3 groups,sham group,I/R group,and ERS pretreatment group. Tread occlusion was used to prepare the model of MCAO in the mice for 60 min followed by reperfusion for 24 h. Neurological assessment was exercised and brain infarction volume was evaluated. The auditory brainstem response was tested. The pathological changes were observed by HE staining. Neurocyte apoptosis was observed by Tunel ,and the apop-tosis index(AI)was determined. Expression of GRP78 and Caspase-12 were detected by immunohistochemistry. Results Compared with the sham group,the neurological scores,ratio of infarct volume and the hearing thresh-olds in I/R group increased significantly. HE staining showed the normal structure disappeared ,and apoptotic index increased significantly. Expression of GRP78 and Caspase-12 protein significantly up-regulated. Compared with I/R group,the indicators above showed improvement to some degrees. Conclusions The ERS pretreatment can alleviate the ischemia-reperfusion injury and neuron apoptosis in auditory cortex ,and reduce the possibility of hearing loss.
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Objective To investigate the mechanism of hearing loss after focal cerebral ischemia-reperfusion injury in rats.Methods A total of 60 healthy male adult SD rats were included in this study and randomly divided into 2 groups, ischemia-reperfusion(I/R) group and sham operated control, with 30 rats in each group.The rats in I/R group were operated for suture-occluded method to establish middle cerebral artery occlusion(MCAO)model, with ischemia for 60 mins followed by reperfusion for 24 hrs.The control group was only to be isolated cervical vessels, with no thread embolism inserted.The auditory brainstem response (ABR) was tested before operation and at 24 hrs post-operation respectively.At 24 hrs post-operation, we scored neurological functions, measured the changes of water content in the brain using the dry-wet weight method, and determined the infarct volume through TTC method.We also evaluated the integrity of blood-brain barrier(BBB) by viewing the exudation of Evans blue and observed the apoptosis of neurocyte by TUNEL method to conclude apoptotic index(AI).The expression of MMP-9,Claudin-5,Occludin and CX-43 were detected by Western blot.Results Compared with the sham group,the neurological function scores,the infarct volume and water content of the brain increased, with the elevated thresholds of ABR significantly and AI went up in I/R group.The expression levels of MMP-9 and CX-43 were significantly up-regulated,but the expressions of Claudin-5 and Occludin were obviously down-regulated.All of the differences above had statistical significances.Conclusion The mechanism of hearing loss after focal cerebral ischemia-reperfusion injury in rats is possibly related to MMPs activation,neurocyte apoptosis,BBB breakage and gap junction damage.
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BACKGROUND: Resistin has been shown to play an important role in the pathogenesis and progression of osteoarthritis. OBJECTIVE: To investigate the correlation between resistin level in serum and synovial fluid and the severity of knee osteoarthritis. METHODS: Seventy-four patients with knee osteoarthritis and 79 healthy individuals were recruited. The Noyes score method was used to assess articular cartilage damage arthroscopically. The severity of knee osteoarthritis was evaluated according to the Western Ontario McMaster University Osteoarthritis (WOMAC) score. The radiographic severity of knee osteoarthritis was assessed by the Kellgren-Lawrence (K-L) grading system. The levels of resistin and cross linked C-telopeptide of type Ⅱ collagen (CTX-Ⅱ) in serum and synovial fluid were determined by ELISA. RESULTS AND CONCLUSION: The resistin level in the synovial fluid was positively correlated with the radiographic severity of knee osteoarthritis, WOMAC pain, WOMAC function, and WOMAC total scores, but showed no correlation with the WOMAC stiffness score. There were no significant correlations between the serum level of resistin and WOMAC total scores, subscale or K-L Grading system in the the osteoarthritis patients. Multiple regression analysis showed that the correlation between the synovial fluid level of resistin and WOMAC scores was of significance after removal of other confounding factors, and the resistin level in the synovial fluid was positively correlated with Noyes scores and CTX-Ⅱ level. These results suggest that the resistin level in the synovial fluid can serve as a potential biomarker reflecting the severity of knee osteoarthritis and cartilage degenerative degree in patients with osteoarthritis.
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BACKGROUND: Our previous studies have found that the Kangguzengsheng Capsules can promote fracture healing.OBJECTIVE: To explore the influence of Kangguzengsheng Capsules-containing serum on the proliferation andosteogenic differentiation of bone marrow mesenchymal stem cells.METHODS: Forty Sprague-Dawley rats were randomly divided into four groups. The capsule powder was resolved into1 mL natural saline and intragastrically administered into rats according to 1.16 g/100 g, 3.48 g/100 g, 10.44 g/100 g in low,medium and high dose groups. Rats in control group were given equal volume of natural saline. After consecutiveadministration for 12 days, blood samples from the abdominal aorta were collected and serum samples were isolated andpreserved until use. Bone marrow mesenchymal stem cells were isolated and purified by the whole marrow adhesion method,and identified by flow cytometry. Harvested cells were divided into four groups and cultured in the osteogenic culture mediumcontaining different kinds of serum samples as described above. MTT method was adopted to test the cell proliferation at 24,48 and 72 hours of culture. Alkaline phosphatase activity in cells was detected at 7 and 14 days of culture. Alkalinephosphatase staining was performed at 7 days of culture, and alizarin red staining performed at 14 days of culture.RESULTS AND CONCLUSION: Compared with the blank control group, bone marrow mesenchymal stem cells showedno significant changes in the proliferative ability and alkaline phosphatase activity in the low dose group, but these twoindices were significantly increased in the high and medium dose groups at 48 and 72 hours of culture or at 7 and 14days of culture, respectively (P < 0.05). Cells positive for alkaline phosphatase and alizarin red staining were observed inthe low, medium and high dose groups, and the cell staining was most remarkable in the high dose group. To conclude,Kangguzengsheng Capsules-containing serum can promote the proliferation and osteogenic differentiation of bonemarrow mesenchymal stem cells.
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Objective To investigate the effect of recombinant human erythropoietin(rh-EPO) on the nerve regeneration of adult rats sciatic nerves. Methods Tirty-six healthy male Wistar rats were involved and left sciatic nerve repaired model was used.The experimental rats were divided randomly into two groups:the EPO group and the control group,18 rats in each group.rh-EPO 3 000 U/kg was injected daily into the abdominal in EPO group,and normal saline was injected into the abdominal every day after operation in control group.On 4 and 8 weeks after operation,these items were determined,the sciatic function index (SFI),biomechanics examination,histological observation,electrophysiological examination,myelinated fibers density and sectional area measurement.Results On weeks 4 after operation,the SFI of EPO group and control group were-65.26 ± 3.42 and-70.83 ± 4.12,respectively,the maximum tensile resistance were (3.86 ± 0.29)N/mm2 and (3.38 ± 0.21 )N/mm2,the delayed ratio of latency of motor nerve were 2.34 ± 0.23 and 2.78 ± 0.29,and the recovery ratio of wave amplitude were 0.23 ± 0.05 and 0.14 ± 0.03 respectively.On eight weeks after operation,the SFI of EPO group and control group were-51.34 ± 2.98 and-57.23 ± 4.86,respcetively,the maximum tensile resistance were (4.67 ± 0.36) N/mm2 and (4.13 ± 0.32) N/mm2,the delayed ratio of latency of motor nerve were 1.32 ± 0.15 and 1.62 ± 0.21,the recovery ratio of wave amplitude were 0.41 ± 0.09 and 0.26 ± 0.07,the nerve fibers cross ratio were 0.57 ± 0.05 and 0.38 ± 0.03,and the recovery ratio of sectional area of myelinated fibers were 0.81 ± 0.06 and 0.58 ± 0.03,respectively.Those items in EPO group were significantly superior to those in the control group (P ＜ 0.05 ＝.Conclusion rh-EPO can promote the injured nerve regeneration and improve the recovery of their function.
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Objective To investigate the biocompatilility of human acellular amniotic membrane(HAM) with vascular smooth muscle cells(VSMCs) and to explore the possibility to construct tissue engineering bladder with HAM as the scaffold and VSMCs as the seed cells. Methods After physical and 1% trypsogen preparation,the HAM was mixed with VSMCs taken from rats for culture in vitro.Histological obserbation was done under inverted microscope and scanning electron microscope respectively.20 rats were divided into two groups.Hemicystectomies were performed in 20 rats,and 10 of them were repaired with HAM grafts with VSMCs on the half bladder,the other 10 were repaired with HAM grafts without VSMCs as the control group.The rats underwent postoperative assessment of bladder volume at the 2nd,4th and 8th weeks,and the grafts were observed by light microscope at the 2nd,4th and 8th weeks after surgery. Results The physical and 1% trypsogen treated HAM was pure with hollows and undamaged collagen fibers.The VSMCs could grow,adhere to and differentiate on the surface of HAM and into the hollows.At the 2nd,4th and 8th weeks after surgery, the bladder volumes of the experimental group were not different significantly compared with those of the control group.Epithelialization and smooth muscle cells regeneration occurred with the infiltration of inflammatory cells in the 2nd week after grafting,and the HAM were absorbed.In the 4th and 8th weeks,it was difficult to delineate the junction between the host bladder and grafts by histology.Conclusion HAM can be used as the scaffold to construct tissue engineering bladder as it has good biocompatibility with VSMCs without disturbing the cell form and the graft can be absorbed quickly.