Objective To explore the regulating mechanism of hepatic injury in obstructive jaundice (OJ). Methods①Rat hepatocytes were isolated by in situ collagenase perfusion and primary culture. Hepatocytes were pretreated with various concentrations of protein kinase C (PKC) agonist parsmeae (PMA) and inhibitor chelerythrine for 20 min. After pretreatment, 50 μmol/L glycochenodeoxycholate (GCDC) was added. Cells were next detected by FCM and TUNEL.②Experimental obstructive jaundice was induced by double ligation of the bile duct (BDL), BDL for 3, 7, 14, 21days.We detected apoptotic status in liver with TUNEL and PKC protein in liver with immunohistochemistry method. Results①PMA increased GCDCinduced apoptosis and chelerythrine decreased GCDCinduced apoptosis in a concentrationdependent manner. ②The apoptotic rate of liver was related to time of OJ. Apoptosis index (AI) was the highest in 14day bile duct ligation. The ber PKC expression, the more number of apoptotic cells in OJ.Conclusion PKC takes part in the regulation and the occurrence and progression of hepatic injury in OJ.
Abstract： Objective To investigate the mechanism of protein kinase C(PKC) in immature myocardial ischemic preconditioning in order to further its clinical applicability. Methods Langendorff perfusion heart models of 24 rabbits were set up and they were randomly divided into 4 groups: ischemic reperfusion group (I/R group), myocardial ischemic preconditioning group (MIP group), chelerythrine group (CLT group) and protein kinase C group (PKC group). The emodynamics, biochemistry and myocardial ultrastructure were observed. Results The heart function recovery and myocardial water content in the MIP and the PKC groups were better than those of the I/R and the CLT groups (Plt;0.01). The adenosine triphosphate (ATP) content, superoxide dismutase activity, mitochondrial Ca2+-ATPase activity and synthesizing ATP activity of mitochondria in the MIP and the PKC groups were significantly higher than those of the I/R and the CLT groups (Plt;0.01). The dehydrogenase and creatine kinase leakage, malondialdehyde content, myocardial cell Ca2+ content and mitochondrial Ca2+ content in the MIP and the PKC groups were significantly lower than those of the I/R and the CLT groups (Plt;0.01). The myocardial ultrastructure injuries in the MIP and the PKC groups were less than that of the I/R and the CLT groups. Conclusion Myocardial ischemic preconditioning plays an important role in protecting immature myocardium, which is probably realized by the activation of PKC.
Objective To study the mRNA expressions of protein kinase C(PKC) and nerve growth factor (NGF) in rat sciatic nerve and the number ofaxons after phorbol-12-myristate-13-acetate (PMA) was injected into silicone chamber. Methods Forty-two SD adult rats were divided into six groups depending on the time of injury (1 day, 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks). A 0.5 cm nerve was cut in doublerat sciatic nerves and “T” type silicone chamber was sutured. PMA at the concentration of 1×10-9mol/L was injected discontinuously into the right side of Ttype silicone chamber(PMA group) and saline was injected into the left side(control group). Nucleic acid in situ hybridization histochemistry technique and thecomputer imagine analysis were employed to detect dynamic changes of PKC mRNA and NGF mRNA in rat sciatic nerves. The number of axons was measured. Results The expressions of PKC mRNA and NGF mRNA increased after injury, and the expressions of PKC mRNA and NGF mRNA reached the peak 2 weeks and3 weeks after injury respectively in control group. The expressions of PKC mRNA and NGF mRNA in PMA group were significantly increased than those in control group 2,3 and 4 weeks after injury(Plt;0.01).The number of axons in PMA group significantly increased than that in control group(Plt;0.01). Conclusion PKC involved inthe expression of NGF mRNA and nerve regeneration after injury. During the regenerated course, PMA can promote the expression of NGF mRNA and the number of axons after injury.
Objective To investigate the alteration of protein kinase C (PKC) and endothelin system in early diabetic rats, and the effect of specific PKC inhibitor on the expression of retinal endothelin-1 (ET-1). Methods The rats model with streptozotocin(STZ)-induced diabetes were set up. The expression of retinal PKC was detected by enzyme-linked immunoabsorbent assay (ELISA). The expression of retinal ET-1, ET-3, ET-A and ET-B receptor mRNA was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The alteration of retinal ET-1 mRNA after intravitreal injection of PKC inhibitor GF109203X in diabetic rats was also observed. Results The activities of membranous PKC were significantly increased in 2-week diabetic rats compared with that in normal rats（t=3.296 , P=0.008）, while activities of cytosolic PKC were unchangeable（t=0.138, P=0.894）. The expression of retinal ET-1 mRNA was significantly increased（P=0.008）, while no change was found in expression of ET-3, ET-A and ET-B mRNA（P=0.918，P=0.889，P=0.500）. After intravitreal in jection of 10-5、10-6、10-7 mol/L PKC inhibitor GF109203X in diabetic rats, the expression of retinal ET-1 mRNA was decreased in a dose-dependent manner compared with the control rats. Conclusion Activation of PKC and increased expression of ET-1 could be found in the retina of early diabetic rats, and PKC inhibitor could inhibit the expression of retinal ET-1. (Chin J Ocul Fundus Dis，2004，20：168-171)
Objective To investigate the effect of hypericin on the activity of protein kinase C (PKC) in cultured human retinal pigment epithelium (RPE) cells in vitro.Methods RPE cells were cultured in standard medium with 10% serum concentrations containing 0.5 to 5.0 μmol/L hypericin with or without preincubation of phorbol 12-myristate 13-acetate (PMA). The activities of cytosolic PKC (c-PKC) and membranous PKC (m-PKC) were assayed by PKC kit. Results The original activities of c-PKC and m-PKC of RPE cells were (35.34±4.10) pmol·min-1·mg-1and (62.52±8.80) pmol·min-1·mg-1.The activity of c-PKC in RPE cells with PMA preincubation decreased rapidly in 5 minutes, with a subsequent slow decrease after 20 minutes and a decrease to 18% of the activity of c-PKC in RPE cells without PMA preinubation after 60 minutes. While the activity of m-PKC in RPE cells with PMA preincubation increased gradually after 5 minutes and reduced after reached the peak at 40 minutes, and then returned to baseline after 60 minutes, eventually decreased below 30% of the control group. When RPE cells were cultured with PMA for 48 hours, the activities of c-PKC and m-PKC were hardly detectable, while RPE cells were cultured with both PMA and hypericin, hypericin could counteract most of down-regulation by PMA. Conclusion Hypericin may inhibit the translocation of PKC in RPE cells,change the activity of PKC, promote the apoptosis of RPE cells likely,and then prevent proliferative vitreoretinopathy. (Chin J Ocul Fundus Dis，2003，19：55-58)
PURPOSE:To evaluate the activitv of protein kinase C(PKC) in response to retinal photochemical insult in rat. Furthermore, to investigate the effect of dexamethasone(DXM ) on PKC activity. METHODS :The experiments were performed on 48 SI') rats whieh were separated into two groups,control and treated groups,and the latter received daily intraperitoneal injections of DXM (1 mg/kg)for 5 consecutive days,starting 3 days before light exposure. The animals were continually exposed to green fluorescent light (510nm~560nm) with an illuminance level of (1 900plusmn;106.9)lx for 24 hrs.The retinal enzyme activity of PKC was tested at 6 hrs,1 day,3 days,7 days,and 14 days after light exposure respectively. RESULTS:In animal models,PKC activity showed a transient increase in both groups at 6 hrs after light exposure and then decrease persistently there alter. The activity of PKC was unresponsive to DXM intervention. CONCLUSIONS :These results suggested that the persistent lower PKC activity might result in disturbance of retinal function in rat retinal photochemical injury. （Chin J Ocul Fundus Dis,1997,13: 78-80）
【摘要】 目的 探讨佛波酯激活的蛋白激酶C与扭转蛋白A在亚细胞成分中的表达之间的关系。 方法 采用免疫荧光法观察扭转蛋白A在原代培养的神经元和小鼠胚胎成纤维细胞（NIH 3T3细胞）中的分布。运用蛋白质印迹法分析蛋白激酶C和扭转蛋白A在细亚细胞成分中的表达。 结果 扭转蛋白A在NIH 3T3细胞中的表达类似于神经元。扭转蛋白A在细胞质溶质、膜成分中均有分布。佛波酯活化蛋白激酶C后并不引起扭转蛋白A在细胞质成分和膜成分中表达含量的变化。 结论 扭转蛋白A可能是膜相关蛋白，细胞氧化应激中扭转蛋白A表达上调和重分布变化不是由佛波酯诱导的蛋白激酶C活化途径来实现的。鉴于扭转蛋白A表达上调具有潜在的治疗原发性早发扭转性肌张力障碍的前景，影响其分布和表达的分子机制需要进一步研究。【Abstract】 Objective To investigate the relationship between the phorbol 12-myristate 13-acetate (PMA) activated protein kinase C (PKC) and the subcellular expression of TorsinA protein. Methods The expression of TorsinA in the primary cultured neurons and the NIH 3T3 cells was detected by immunofluorescence. The expression of PKC and TorsinA in subcellular fraction was analyzed by the western blotting. Results The expression pattern of TorsinA in NIH 3T3 cells was similar to neuron. PMA, an activator of PKC, did not promote the up-expression of TorsinA or redistribution in the subcellular fraction of NIH 3T3 cells. Conclusions TorsinA may be a membrane-associated protein. The up-regulation and redistribution of TorsinA is not caused by the pathway of the PMA activating PKC after cells insulted by oxidative stress. We should pay more attention on the mechanisms of the expression of TorsinA protein for the potential therapies to early-onset primary torsion dystonia (DYT1).
ObjectiveThe purpose of this study was to explore the expression of Corticotropin releasing hormone (CRH), Corticotropin releasing hormone receptor 1 (CRHR1), Protein kinase C (PKC) in epileptogenic zone of Infantile spasm (IS).MethodsCollected 17 cases of tissues of IS patients from operation and 6 cases of normal brain tissues from clinical autopsy during June 2011 to June 2014. Westen blot was used to detected the protein expression of CRH, CRHR1, PKC. PCR was used to exam the mRNA expression of CRH, CRHR1, PKC. Immunohistochemistry and fluorescenceimmuno assay were used to detect the expression of CRH, CRHR1, PKC.ResultsThe mRNA expression of CRH and CRHR1 in IS group are higher than control group, and the protein expression of CRH and CRHR1 in IS group are higher than control group. CRH are slightly expressed in the controls, medium and strong expressed in IS, CRH and NF200 both expressed in IS; CRH is negative in GFAP positive astrocyte; CRH is negative in HLA positive microglial cell. CRHR1 are slightly and medium expressed in the controls, medium and strong expressed in IS, CRHR1 and NF200 both expressed in IS; CRHR1 and GFAP are both positive in astrocyte; CRHR1 and HLA are both positive in microglial cell. PKC are slightly and medium expressed in the controls, medium and strong expressed in IS, PKC and NF200 both expressed in IS; PKC and GFAP are both positive in astrocyte; PKC and HLA are both positive in microglial cell. Spearman analysis showed positive correlation between the expression of CRH, CRHR1, PKC with epileptic spasm in IS patients, as well as positive correlation between PKC with CRHR1.ConclusionsOver expression of CRH, CRHR1, PKC with epileptic spasm in IS patients were positive related with epileptic seizure in IS patients, indicated that CRH signal pathway is related with IS pathogenesis.