基于Rho/Rho-kinase信号通路探讨丙泊酚减轻大鼠脑缺血再灌注损伤的效果

目的基于Rho/Rho-kinase信号通路探讨丙泊酚减轻大鼠脑缺血再灌注损伤的效果。方法 SD大鼠100只分成:对照组、模型组、丙泊酚低、中、高剂量组(20.0、40.0、80.0 mg/kg),模型组、丙泊酚低、中、高剂量组建立脑缺血再灌注损伤模型,建模成功后,丙泊酚低、中、高剂量组给予相应剂量丙泊酚灌胃,对照组和模型组给予等体积生理盐水,持续给予4周,实验结束后,对每只大鼠进行神经功能缺损评分,行贴纸去除及平衡木行走实验,对大鼠海马区进行病理评分,同时测定大鼠脑组织中Rho、Rho-kinase mRNA和蛋白水平。结果模型组神经功能缺损评分、双侧贴纸去除时间、平衡木过杆时间、海马组织病理评分、脑组织海马区Rho、Rho-kinase mRNA和蛋白表达水平明显高于对照组(P<0.05);丙泊酚各剂量组神经功能缺损评分、双侧贴纸去除时间、平衡木过杆时间、海马组织病理评分、脑组织海马区Rho、Rho-kinase mRNA和蛋白表达水平明显低于模型组(P<0.05);且随着丙泊酚给药剂量的增加,神经功能缺损评分、双侧贴纸去除时间、平衡木过杆时间、海马组织病理评分、脑组织海马区Rho、Rho-kinase mRNA和蛋白表达水平逐渐降低,剂量-效应关系明显(P<0.05)。对照组海马区神经元细胞完整,排列紧密;模型组海马区神经元排列松散,细胞深染固缩,有片状坏死,神经细胞间质隔离;丙泊酚高剂组神经元细胞趋于正常;丙泊酚中、低剂量组较模型组而言,神经细胞疏松、固缩程度轻,神经元细胞核仁清楚可见。结论丙泊酚能减轻大鼠脑缺血再灌注神经功能损伤;其机制与丙泊酚能抑制Rho、Rho-kinase mRNA和蛋白的表达进而抑制Rho/Rho-kinase信号通路的激活有关。

抑制Rho-kinase在柔红霉素诱导的肾小球硬化中的作用及机制

目的:研究抑制Rho-kinase对柔红霉素诱导的肾小球硬化的调控作用,并探讨Rho-kinase抑制剂法舒地尔改善肾小球硬化的作用机制。方法:36只雄性SD大鼠,随机分为三组:假手术(Sham)组,单侧肾脏切除+柔红霉素(模型)组,单侧肾脏切除+柔红霉素+法舒地尔(干预)组,每组各12只。模型组和干预组大鼠在切除左肾后第7、14天,从尾静脉各注射柔红霉素5 mg/kg 1次,同时Sham组大鼠以等剂量的生理盐水尾静脉注射。干预组在第2次注射柔红霉素后从腹腔每天注射法舒地尔3 mg/kg,完成上述处理后的第2、4周,随机取各组大鼠6只处死留取肾标本,处死前收集24 h尿液检测尿蛋白排泄,用HE,PAS染色,免疫组化,透射电镜进行肾组织病理学分析,应用RT-PCR检测Rho-kinase,P27的核酸表达水平。结果:(1)模型组较Sham组24 h尿蛋白明显升高(P<0.01),而法舒地尔干预后,干预组24 h尿蛋白较模型组显著降低(P<0.05)。(2)模型组大鼠足细胞第4周时出现了弥漫性足突融合,系膜基质增殖明显,出现典型的肾小球节段性硬化,免疫组化PCNA表达升高,P27表达下降;而干预组可以改善柔红霉素诱导的肾小球硬化大鼠足细胞的病理改变,系膜细胞增生受抑制,系膜基质蓄积减少,较模型组PCNA表达下降,P27升高。(3)模型组较Sham组Rho-kinase的mRNA表达升高,细胞周期抑制蛋白P27 mRNA的表达下降,而干预组较模型组Rho-kinase的mRNA表达显著降低,P27 mRNA的表达明显升高。结论:(1)抑制Rho-kinase的表达能明显改善柔红霉素诱导的大鼠的肾小球硬化。(2)法舒地尔的作用机制可能是通过改善足细胞的病理改变,减少蛋白尿,升高细胞周期抑制蛋白P27的表达,从而抑制系膜基质增殖,延缓肾小球硬化的进展。

Clinical significance of upregulated Rho GTPase activating protein 12 causing resistance to tyrosine kinase inhibitors in hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is a major health challenge with high incidence and poor survival rates in China.Systemic therapies,particularly tyrosine kinase inhibitors(TKIs),are the first-line treatment for advanced HCC,but resistance is common.The Rho GTPase family member Rho GTPase activating protein 12(ARHGAP12),which regulates cell adhesion and invasion,is a potential therapeutic target for overcoming TKI resistance in HCC.However,no studies on the expression of ARHGAP12 in HCC and its role in resistance to TKIs have been reported.AIM To unveil the expression of ARHGAP12 in HCC,its role in TKI resistance and its potential associated pathways.METHODS This study used single-cell RNA sequencing(scRNA-seq)to evaluate ARHGAP12 mRNA levels and explored its mechanisms through enrichment analysis.CellChat was used to investigate focal adhesion(FA)pathway regulation.We integrated bulk RNA data(RNA-seq and microarray),immunohistochemistry and proteomics to analyze ARHGAP12 mRNA and protein levels,correlating with clinical outcomes.We assessed ARHGAP12 expression in TKI-resistant HCC,integrated conventional HCC to explore its mechanism,identified intersecting FA pathway genes with scRNA-seq data and evaluated its response to TKI and immunotherapy.RESULTS ARHGAP12 mRNA was found to be highly expressed in malignant hepatocytes and to regulate FA.In malignant hepatocytes in high-score FA groups,MDK-[integrin alpha 6(ITGA6)+integrinβ-1(ITGB1)]showed specificity in ligand-receptor interactions.ARHGAP12 mRNA and protein were upregulated in bulk RNA,immunohistochemistry and proteomics,and higher expression was associated with a worse prognosis.ARHGAP12 was also found to be a TKI resistance gene that regulated the FA pathway.ITGB1 was identified as a crossover gene in the FA pathway in both scRNA-seq and bulk RNA.High expression of ARHGAP12 was associated with adverse reactions to sorafenib,cabozantinib and regorafenib,but not to immunotherapy.CONCLUSION ARHGAP12 expression is elevated in HCC and TKI-resistant HCC,and its regulatory role in FA may underlie the TKI-resistant phenotype.

Advantages of Rho-associated kinases and their inhibitor fasudil for the treatment of neurodegenerative diseases

Ras homolog(Rho)-associated kinases(ROCKs)belong to the serine-threonine kinase family,which plays a pivotal role in regulating the damage,survival,axon guidance,and regeneration of neurons.ROCKs are also involved in the biological effects of immune cells and glial cells,as well as the development of neurodegenerative disorders such as Alzheimer’s disease,Parkinson’s disease,and multiple sclerosis.Previous studies by us and others confirmed that ROCKs inhibitors attenuated the symptoms and progression of experimental models of the abovementioned neurodegenerative diseases by inhibiting neuroinflammation,regulating immune imbalance,repairing the blood-brain barrier,and promoting nerve repair and myelin regeneration.Fasudil,the first ROCKs inhibitor to be used clinically,has a good therapeutic effect on neurodegenerative diseases.Fasudil increases the activity of neural stem cells and mesenchymal stem cells,thus optimizing cell therapy.This review will systematically describe,for the first time,the effects of abnormal activation of ROCKs on T cells,B cells,microglia,astrocytes,oligodendrocytes,and pericytes in neurodegenerative diseases of the central nervous system,summarize the therapeutic potential of fasudil in several experimental models of neurodegenerative diseases,and clarify the possible cellular and molecular mechanisms of ROCKs inhibition.This review also proposes that fasudil is a novel potential treatment,especially in combination with cell-based therapy.Findings from this review add support for further investigation of ROCKs and its inhibitor fasudil for the treatment of neurodegenerative diseases.

Inhibition of RhoA/Rho-kinase pathway suppresses the expression of extracellular matrix induced by CTGF or TGF-β in ARPE-19

AIM:To investigate the role of Rho-associated protein kinase (ROCK) inhibitor, Y27632, in mediating the production of extracellular matrix (ECM) components including fibronectin, matrix metallo-proteinase-2 (MMP-2) and type I collagen as induced by connective tissue growth factor(CTGF) or transforming growth factor-β (TGF-β) in a human retinal pigment epithelial cell line, ARPE-19. METHODS:The effect of Y27632 on the CTGF or TGF-β induced phenotype in ARPE-19 cells was measured with immunocytochemistry as the change in F-actin. ARPE-19 cells were treated with CTGF (1, 10, 100ng/mL)and TGF-β (10ng/mL) in serum free media, and analyzed for fibronectin, laminin, and MMP-2 and type I collagen by RT-qPCR and immunocytochemistry. Cells were also pretreated with an ROCK inhibitor, Y27632, to analyze the signaling contributing to ECM production. ·RESULTS:Treatment of ARPE-19 cells in culture with TGF-β or CTGF induced an ECM change from a cobblestone morphology to a more elongated swirl pattern indicating a mesenchymal phenotype. RT-qPCR analysis and different gene expression analysis demonstrated an upregulation in expression of genes associated with cytoskeletal structure and motility. CTGFor TGF-β significantly increased expression of fibronectin mRNA (P =0.006, P =0.003 respectively), laminin mRNA (P =0.006, P =0.005), MMP-2 mRNA (P =0.006, P =0.001), COL1A1 mRNA (P =0.001, P =0.001), COL1A2 mRNA (P = 0.001, P =0.001). Preincubation of ARPE-19 with Y27632 (10mmol/L) significantly prevented CTGF or TGF-β induced fibronectin (P=0.005, P=0.003 respectively), MMP-2 (P = 0.003, P =0.002), COL1A1 (P =0.006, P =0.003), and COL1A2 (P =0.006, P =0.004) gene expression, but not laminin (P =0.375, P =0.516). CONCLUSION:Our study demonstrated that both TGF-β and CTGF upregulate the expression of ECM components including fibronectin, laminin, MMP-2 and type I collagen by activating the RhoA/ROCK signaling pathway. During this process, ARPE-19 cells were shown to change from an epithelial to a mesenchymal phenotype in vitro. Y27632, a ROCK inhibitor, inhibited the transcription of fibronectin, MMP-2 and type I collagen, but not laminin. The data from our work suggest a role for CTGF as a profibrotic mediator. Inhibiting the RhoA/ROCK pathway represents a potential target to prevent the fibrosis of retinal pigment epithelial (RPE) cells. This might lead to a novel therapeutic approach to preventing the onset of early proliferative vitreoretinopathy(PVR).

The role of Rho/Rho-kinase pathway and the neuroprotective effects of fasudil in chronic cerebral ischemia

The Rho/Rho-kinase signaling pathway plays an important role in cerebral ischemia/reperfusion injury. However, very few studies have examined in detail the changes in the Rho/Rho-kinase signaling pathway in chronic cerebral ischemia. In this study, rat models of chronic cerebral ischemia were established by permanent bilateral common carotid artery occlusion and intra- gastrically administered 9 mg/kg fasudil, a powerful ROCK inhibitor, for 9 weeks. Morris water maze results showed that cognitive impairment progressively worsened as the cerebral ischemia proceeded. Immunohistochemistry, semi-quantitative RT-PCR and western blot analysis showed that the expression levels of Rho-kinase, its substrate myosin-binding subunit, and its relat- ed protein alpha smooth muscle actin, significantly increased after chronic cerebral ischemia. TUNEL staining showed that chronic cerebral ischemia could lead to an increase in neuronal apoptosis, as well as the expression level of caspase-3 in the frontal cortex of rats subjected to chronic cerebral ischemia. Fasudil treatment alleviated the cognitive impairment in rats with chronic cerebral ischemia, and decreased the expression level of Rho-kinase, myosin-binding subunit and alpha smooth muscle actin. Furthermore, fasudil could regulate cerebral injury by reducing cell apoptosis and decreasing caspase-3 expression in the frontal cortex. These findings demonstrate that fasudil can protect against cognitive impairment induced by chronic cerebral ischemia via the Rho/Rho-kinase signaling pathway and anti-apoptosis mechanism.

Long-term culture-induced phenotypic difference and efficient cryopreservation of small intestinal organoids by treatment timing of Rho kinase inhibitor

To investigate a suitable long-term culture system and optimal cryopreservation of intestinal organoid to improve organoid-based therapy by acquiring large numbers of cells.METHODSCrypts were isolated from jejunum of C57BL/6 mouse. Two hundred crypts were cultured in organoid medium with either epidermal growth factor/Noggin/R-spondin1 (ENR) or ENR/CHIR99021/VPA (ENR-CV). For subculture, organoids cultured on day 7 were passaged using enzyme-free cell dissociation buffer (STEMCELL Technologies). The passage was performed once per week until indicated passage. For cryopreservation, undissociated and dissociated organoids were resuspended in freezing medium with or without Rho kinase inhibitor subjected to different treatment times. The characteristics of intestinal organoids upon extended passage and freeze-thaw were analyzed using EdU staining, methyl thiazolyl tetrazolium assay, qPCR and time-lapse live cell imaging.RESULTSWe established a three-dimensional culture system for murine small intestinal organoids using ENR and ENR-CV media. Both conditions yielded organoids with a crypt-villus architecture exhibiting Lgr5+ cells and differentiated intestinal epithelial cells as shown by morphological and biochemical analysis. However, during extended passage (more than 3 mo), a comparative analysis revealed that continuous passaging under ENR-CV conditions, but not ENR conditions induced phenotypic changes as observed by morphological transition, reduced numbers of Lgr5+ cells and inconsistent expression of markers for differentiated intestinal epithelial cell types. We also found that recovery of long-term cryopreserved organoids was significantly affected by the organoid state, i.e., whether dissociation was applied, and the timing of treatment with the Rho-kinase inhibitor Y-27632. Furthermore, the retention of typical morphological characteristics of intestinal organoids such as the crypt-villus structure from freeze-thawed cells was observed by live cell imaging.CONCLUSIONThe maintenance of the characteristics of intestinal organoids upon extended passage is mediated by ENR condition, but not ENR-CV condition. Identified long-term cryopreservation may contribute to the establishment of standardized cryopreservation protocols for intestinal organoids for use in clinical applications.

Rho-associated protein kinase modulates neurite extension by regulating microtubule remodeling and vinculin distribution

Rho-associated protein kinase is an essential regulator of cytoskeletal dynamics during the process of neurite extension. However, whether Rho kinase regulates microtubule remodeling or the distri- bution of adhesive proteins to mediate neurite outgrowth remains unclear. By specifically modulat- ing Rho kinase activity with pharmacological agents, we studied the morpho-dynamics of neurite outgrowth. We found that lysophosphatidic acid, an activator of Rho kinase, inhibited neurite out- growth, which could be reversed by Y-27632, an inhibitor of Rho kinase. Meanwhile, reorganization of microtubules was noticed during these processes, as indicated by their significant changes in the soma and growth cone. In addition, exposure to lysophosphatidic acid led to a decreased mem- brane distribution of vinculin, a focal adhesion protein in neurons, whereas Y-27632 recruited vin- culin to the membrane. Taken together, our data suggest that Rho kinase regulates rat hippocampal neurite growth and microtubule formation via a mechanism associated with the redistribution of vinculin.

苦参碱调节RhoA-ROCK信号通路对冠心病模型大鼠Th17/Treg细胞平衡的影响

目的探讨苦参碱(Matrine)对冠心病(coronary heart disease,CHD)大鼠辅助T细胞17(helper T cell 17,Th17)/调节性T细胞(regulatory T cells,Treg)细胞平衡及Ras同源基因家族成员A(RhoA)-Rho相关的卷曲螺旋激酶(ROCK)信号通路的影响。方法建立冠心病模型,将实验大鼠分为对照组、模型组、苦参碱低剂量(50 mg·kg^(-1))组、苦参碱高剂量(200 mg·kg^(-1))组及苦参碱高剂量(200 mg·kg^(-1))+LPA组(10 mg·kg^(-1))。超声心动图进行大鼠心功能检测;酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)法进行白细胞介素17(IL-17)、转化生长因子β(TGF-β)水平检测;流式细胞术检测Th17、Treg数量及Th17/Treg比值;免疫组化进行内皮型一氧化氮合酶(eNOS)、内皮素1(ET-1)蛋白表达水平检测;Masson染色进行大鼠心肌组织的病理形态变化观察;TTC染色检测各组大鼠心肌梗死情况;TUNEL染色进行心肌组织中细胞凋亡情况检测;试剂盒检测RhoA活性;Western Blot法进行半胱氨酸天冬氨酸蛋白酶3(Caspase-3)、B细胞淋巴瘤因子2(Bcl-2)、Bcl-2相关X蛋白(Bax)、RhoA、ROCK1、ROCK2蛋白表达水平检测。结果与对照组比较,模型组心肌组织有大量蓝色胶原纤维沉积,左室舒张末期容积(left ventricular end-diastolic volume,LVEDV)、左室收缩末期容积(left ventricular end-systolic volume,LVESV)、IL-17、Th17、Th17/Treg、ET-1、心肌梗死面积、细胞凋亡率、TUNEL阳性率、Bax、Caspase-3、RhoA活性、RhoA、ROCK1、ROCK2表达水平明显升高,左室射血分数(left ventricular ejection fraction,LVEF)、左室缩短分数(left ventricular shortening fraction,LVFS)、TGF-β、Treg、eNOS、Bcl-2表达水平明显降低(P<0.05)。与模型组比较,Matrine-L组、苦参碱高剂量组心肌组织蓝色胶原纤维逐渐减少,LVEDV、LVESV、IL-17、Th17、Th17/Treg、ET-1、心肌梗死面积、细胞凋亡率、TUNEL阳性率、Bax、Caspase-3、RhoA活性、RhoA、ROCK1、ROCK2表达水平依次明显降低,LVEF、LVFS、TGF-β、Treg、eNOS、Bcl-2表达水平依次明显升高(P<0.05)。与苦参碱高剂量组比较,苦参碱高剂量+LPA组心肌组织蓝色胶原纤维增多,LVEDV、LVESV、IL-17、Th17、Th17/Treg、ET-1、心肌梗死面积、细胞凋亡率、TUNEL阳性率、Bax、Caspase-3、RhoA活性、RhoA、ROCK1、ROCK2表达水平明显升高,LVEF、LVFS、TGF-β、Treg、eNOS、Bcl-2表达水平明显降低(P<0.05)。结论苦参碱通过抑制RhoAROCK信号通路调节Th17/Treg细胞平衡,改善冠心病大鼠心肌损伤。

A Rho-kinase Inhibitor, Fasudil, Attenuates Progressive Glomerulosclerosis Induced by Daunorubicin in Rats

Accumulating evidence suggests that the small G protein Rho and its downstream effec-tor Rho kinase may play important roles in kidney biology. The present study examined the effects of a Rho-kinase inhibitor, fasudil, on daunorubicin-induced progressive glomerulosclerosis and explored the underlying mechanism by which fasudil ameliorates glomerulosclerosis. Thirty-six male SD rats were randomly allocated into sham-operation group （sham group, n=12）, unilateral nephrectomy （UNX）＋daunorubicin （DRB） group （model group, n=12）, UNX＋DRB＋Fasudil group （treatment group, n=12）. Two to four weeks after the establishment of the animal model, 6 rats in each group were taken randomly for the detection of 24-h urine protein excretion. Kidney sections were exam-ined by HE and PAS staining, immunohistochemistry and transmission electric microscopy （TEM）. The expression of Rho-kinase mRNA and P27 mRNA in kidney were detected by RT-PCR. It was found that the 24-h urine protein excretion in model group was increased significantly as compared with sham group （P〈0.01）. But this increase was significantly suppressed by fasudil （P〈0.05）. At 4 week, the foot process effacement in podocytes, mesangial proliferation and ECM accumulation were observed in model group, presenting as focal segmental glomerulosclerosis. But in the treatment group, the fasudil alleviated glomerular injury, with proliferating cell nuclear antigen （PCNA）-positive cell infiltration ameliorated and the expression of P27 increased. The expression of Rho-kinase mRNA was significantly enhanced in model group and was suppressed in treatment group. Moreover, fasudil up-regulated the mRNA expression of P27. Our study demonstrated that the glomerulosclerosis was substantially ameliorated by inhibiting the expression of Rho-kinase. It is suggested that Rho-kinase pathway is involved in the renal injury and the inhibition of Rho-kinase may constitute a therapeutic strategy for the treatment of renal injury.

Effect of Rho-kinase pathway on neurite outgrowth of rat hippocampal neurons under atomic force microscopy

Hippocampal neurons of neonatal rats were cultured in serum-free culture medium for 5 days in vitro, and treated with the Rho-kinase inducer lysophosphatidic acid. Atomic force microscopy revealed that the numbers of level-1, -2 and -3 neurites protruding from rat hippocampal neurons was significantly reduced. After treatment with the Rho kinase inhibitor Y27632, a significant increase in the numbers of these neurites was observed. Our experimental findings indicate that the Rho-kinase pathway is closely associated with the neurites of hippocampal neurons.

Downregulation of rho-associated protein kinase 1 by mi R-124 in colorectal cancer

AIM: To investigate the roles and interactions of rhoassociatedprotein kinase (ROCK)1 and miR-124 inhuman colorectal cancer (CRC).METHODS: Expression of ROCK1 protein wasexamined by Western blotting, and quantitativereverse transcriptase PCR was performed to measureexpression of ROCK1 mRNA and miR-124. Two cancercell lines were transfected with pre-miR-124 (mimic)and anti-miR-124 (inhibitor) and the effects onROCK1 protein and mRNA expression were observed.In addition, cell proliferation was assessed via a5-ethynyl-2′ deoxyuridine assay. Soft agar formationassay, and cell migration and invasion assays wereused to determine the effect of survivin on thetransformation and invasion activity of CRC cells.RESULTS: miR-124 was significantly downregulated inCRC compared to normal specimens (0.603 ± 0.092 vs1.147 ± 0.286, P = 0.016) and in metastatic comparedto nonmetastatic CRC specimens (0.416 ± 0.047 vs0.696 ± 0.089, P = 0.020). Expression of miR-124 wassignificantly associated with CRC metastasis, tumor Tand N stages, and tumor grade (all P < 0.05). ROCK1protein was significantly increased in CRC comparedto normal tissues (1.896 ± 0.258 vs 0.866 ± 0.136,P = 0.026), whereas ROCK1 mRNA expression wasunaltered (2.613 ± 0.251 vs 2.325 ± 0.246). miR-124and ROCK1 were inversely expressed in CRC tissuesand cell lines. ROCK1 mRNA was unaltered in cellstransfected with miR-124 mimic and miR-124 inhibitor,compared to normal controls. There was a significantreduction in ROCK1 protein in cells transfected withmiR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (P s < 0.05).Transformation and invasion of cells transfectedwith miR-124 inhibitor were significantly increasedcompared to those in normal controls (P < 0.05). Cellstransfected with miR-124 inhibitor showed increasedcell proliferation.CONCLUSION: miR-124 promotes hyperplasia andcontributes to invasion of CRC cells, but downregulatesROCK1. ROCK1 and miR-124 may play important rolesin CRC.

Tolerance of neurite outgrowth to Rho kinase inhibitors decreased by cyclooxygenase-2 inhibitor

In this study, PC12 Adh cells and Neuro-2a cells were treated with Rho-associated kinase inhibitors （Y27632 and Fasudil）, a cyclooxygenase-1 selective inhibitor （SC560）, and a cyclooxygenase-2 inhibitor （NS398）. We found that these cells became tolerant to Rho-associated kinase inhibitors, as neurite outgrowth induced by these inhibitors diminished following more than 3 days of exposure in either cell line. The proteins cyclooxygenase-2 and cytosolic prostaglandin E synthetase were upregulated at day 3. NS398 decreased the tolerance to neurite outgrowth induction in both cell lines, whereas SC560 had almost no effect. These findings indicate that cells become tolerant to neurite outgrowth induced by Rho-associated kinase inhibitors, this is at least partly associated with upregulation of proteins involved in the cyclooxygenase-2 pathway, and cyclooxygenases-2 inhibition prevents this tolerance.

Effect of electroacupuncture on the mRNA and protein expression of Rho-A and Rho-associated kinase Ⅱ in spinal cord injury rats

Electroacupuncture is beneficial for the recovery of spinal cord injury, but the underlying mechanism is unclear. The Rho/Rho-associated kinase（ROCK） signaling pathway regulates the actin cytoskeleton by controlling the adhesive and migratory behaviors of cells that could inhibit neurite regrowth after neural injury and consequently hinder the recovery from spinal cord injury. Therefore, we hypothesized electroacupuncture could affect the Rho/ROCK signaling pathway to promote the recovery of spinal cord injury. In our experiments, the spinal cord injury in adult Sprague-Dawley rats was caused by an impact device. Those rats were subjected to electroacupuncture at Yaoyangguan（GV3）, Dazhui（GV14）, Zusanli（ST36） and Ciliao（BL32） and/or monosialoganglioside treatment. Behavioral scores revealed that the hindlimb motor functions improved with those treatments. Real-time quantitative polymerase chain reaction, fluorescence in situ hybridization and western blot assay showed that electroacupuncture suppressed the m RNA and protein expression of Rho-A and Rho-associated kinase Ⅱ（ROCKⅡ） of injured spinal cord. Although monosialoganglioside promoted the recovery of hindlimb motor function, monosialoganglioside did not affect the expression of Rho-A and ROCKⅡ. However, electroacupuncture combined with monosialoganglioside did not further improve the motor function or suppress the expression of Rho-A and ROCKⅡ. Our data suggested that the electroacupuncture could specifically inhibit the activation of the Rho/ROCK signaling pathway thus partially contributing to the repair of injured spinal cord. Monosialoganglioside could promote the motor function but did not suppress expression of Rho A and ROCKⅡ. There was no synergistic effect of electroacupuncture combined with monosialoganglioside.

阿魏酸钠经RhoA和Rho-kinase信号通路抑制小鼠肝纤维化的机制研究

目的:探讨阿魏酸钠对于四氯化碳诱导的小鼠肝纤维化的抑制机制。方法:将CL级昆明属小鼠随机分为正常对照组、CCl4-花生油模型组(模型组)、阿魏酸钠给药组(给药组),每组20只。模型组小鼠和给药组小鼠分别给予CCl4-花生油(1∶1,V/V)1ml/kg灌胃,正常对照组小鼠给予同等剂量生理盐水,三组均为1次/d,连续8周;从第9周开始,给药组小鼠给予阿魏酸钠20mg/kg灌胃,1次/d,连续给药4周。12周后,检测各组小鼠肝功能水平、肝影像学指标、病理变化及肝脏中RhoA、Rho-kinase的总体情况。结果:通过正常对照组、模型组及给药组的小鼠肝功能和肝纤维化指标等指标对比,发现阿魏酸钠能显著抑制小鼠肝纤维化程度。结论:阿魏酸钠可能通过调节RhoA和Rho-kinase信号通路抑制小鼠肝纤维化。

TGF-β1-induced LPP Expression Dependant on Rho Kinase during Differentiation and Migration of Bone Marrow-derived Smooth Muscle Progenitor Cells

Lipoma preferred partner(LPP) has been identified as a protein which is highly selective for smooth muscle progenitor cells(SMPCs) and regulates differentiation and migration of SMPCs,but mechanisms of LPP expression are not elucidated clearly.The aim of the present study was to discuss the mechanisms by which LPP expression is regulated in the differentiation and migration of SMPCs induced by TGF-β1.It was found that TGF-β1 could significantly increase the expression of LPP,smooth muscle α-actin,smooth muscle myosin heavy chain(SM-MHC),and smoothelin in SMPCs.Moreover,inactivation of Rho kinase(ROK) with ROK inhibitors significantly inhibited LPP mRNA expression in TGF-β1-treated SMPCs and mouse aortic smooth muscle cells(MAoSMCs).At the same time,LPP silencing with short interfering RNA significantly decreased SMPCs migration.In conclusion,LPP appears to be a ROK-dependant SMPCs differentiation marker that plays a role in regulating SMPCs migration.

精氨酸血管加压素抗失血性休克作用及其与Rho kinase的关系

目的观察精氨酸血管加压素(arginine vasopressin,AVP)抗失血性休克作用与Rho kinase的关系。方法采用大鼠失血性休克模型,整体动物观察AVP对失血性休克大鼠去甲肾上腺素(NE)的升压反应和对肠系膜上动脉收缩反应性的影响,同时观察Rho kinase在其中的作用;离体血管环观察AVP对失血性休克大鼠肠系膜上动脉反应性和钙敏感性的影响,并观察Rho kinase在其中的作用。结果失血性休克后大鼠对NE的升压反应性和肠系膜动脉对NE的收缩反应性明显降低,AVP 0.4U/kg可明显增加休克大鼠NE升压反应和肠系膜动脉的收缩反应性,Rho kinase特异性抑制剂Y-27632可明显拮抗由AVP引起的休克大鼠血管反应性的增加。在离体血管环研究表明,休克后血管反应性和钙敏感性明显降低,AVP在浓度为5nmol/L和0.5nmol/L可明显增加休克后血管反应性和钙敏感性,Y-27632可明显拮抗由AVP引起的血管反应性和钙敏感性的增加。结论AVP可通过增加休克血管平滑肌细胞的钙敏感性和血管反应性发挥抗休克作用,通过激活Rho kinase发挥其抗休克作用。

Therapeutic potential of Rho-associated kinase inhibitor Y27632 in corneal endothelial dysfunction:an in vitro and in vivo study

AIM:To investigate the effects of a selective inhibitor of Rho-associated kinase(ROCK),Y-27632,on inbred Wuzhishan porcine corneal endothelial cells(PCECs)in vitro and in vivo studies.METHODS:Primary PCECs were trypsinized from Wuzhishan miniature porcine corneal tissues.The optimal concentration of Y-27632 on PCECs was determined through MTT and 5-ethynyl-2'-deoxyuridine(EdU)-labeling assays.Seven New Zealand rabbits were used as a corneal endothelial dysfunction model,and a PCECs suspension supplemented with Y-27632 was injected into the anterior chamber of the rabbits.The progression of rabbit corneal opacity and edema were observed by slit lamp examination.The rabbits were sacrificed,and rabbit globes were enucleated for trypan blue-alizarin red staining,hematoxylineosin staining,and immunofluorescence analysis.RESULTS:Administration of 100μmol/L Y-27632 facilitated PCECs'proliferation obviously.The rabbit corneas injected with PCECs suspension and 100μmol/L Y-27632 were restored to transparency significantly after 14d.CONCLUSION:The 100μmol/L Y-27632 treatment improves PCECs'proliferation significantly.And our results suggest that Y-27632 and PCECs can be used to treat corneal endothelial dysfunction.

Rho kinase:A new target for treatment of cerebral ischemia/reperfusion injury

Rho kinase inhibitor fasudil hydrochloride has been shown to reduce cerebral vasospasm, to inhibit inflammation and apoptosis and to promote the recovery of neurological function. However, the effect of fasudil hydrochloride on claudin-5 protein expression has not been reported after cerebral ischemia/reperfusion. Therefore, this study sought to explore the effects of fasudil hydrochloride on blood-brain barrier permeability, growth-associated protein-43 and claudin-5 protein expression, and to further understand the neuroprotective effect of fasudil hydrochloride. A focal cerebral ischemia/reperfusion model was established using the intraluminal suture technique. Fasudil hydrochloride （15 mg/kg） was intraperitoneally injected once a day. Neurological deficit was evaluated using Longa＇s method. Changes in permeability of blood-brain barrier were measured using Evans blue. Changes in RhoA, growth-associated protein-43 and claudin-5 protein expression were detected using immunohistochemistry and western blotting. Results revealed that fasudil hydrochloride noticeably contributed to the recovery of neurological function, improved the function of blood-brain barrier, inhibited RhoA protein expression, and upregulated growth-associated protein-43 and claudin-5 protein expression following cerebral ischemia/reperfusion. Results indicated that Rho kinase exhibits a certain effect on neurovascular damage following cerebral ischemia/reperfusion. Intervention targeted Rho kinase might be a new therapeutic target in the treatment of cerebral ischemia/reperfusion.

Rho A/Rho kinase in spinal cord injury

A spinal cord injury refers to an injury to the spinal cord that is caused by a trauma instead of diseases. Spinal cord injury includes a primary mechanical injury and a much more complex secondary injury process involving inflammation, oxidation, excitotoxicity, and cell death. During the secondary injury, many signal pathways are activated and play important roles in mediating the pathogenesis of spinal cord injury. Among them, the Rho A/Rho kinase pathway plays a particular role in mediating spinal degeneration and regeneration. In this review, we will discuss the role and mechanism of Rho A/Rho kinase-mediated spinal cord pathogenesis, as well as the potential of targeting Rho A/Rho kinase as a strategy for promoting both neuroprotection and axonal regeneration.