Protein kinase C (PKC) plays an important role not only in signal transduction mechanisms in various biological processes, but also in the regulation of growth and differentiation during development. We studied the classical PKC alpha, betaI, betaII and gamma, with regard to their expression in adult and developing rat kidney. PKCalpha appeared in the ureteric bud at embryonic day (E) 16, and the proximal and distal anlage at E18. After birth, the immunoreactivity of PKCalpha gradually decreased. In adult, PKCalpha was expressed intensely in the connecting tubule (CNT), the collecting ducts (CD) and the renal corpuscle, and weakly in the proximal and distal tubules. PKCbetaI appeared in the ureteric bud at E16, and the proximal anlage at E18. After birth, the immunoreactivity of PKCbetaI gradually disappeared from the CD and proximal tubule. In adult, PKCbetaI was expressed in the intercalated cells of the CNT and cortical CD, the proximal straight tubule, and the renal corpuscle. PKCbII appeared in distal anlage at E18, and increased markedly after birth. In the CD, PKCbetaII immunoreactivity appeared after birth. In adult, PKCbetaII was expressed in the distal tubule, the CNT and the CD. The immunoreactivity for PKCgamma appeared only in the proximal anlage at E18, and increased temporally around the time of birth. However, no immunoreactivity for PKCgamma was observed in adult rat kidney. These results indicate that classical PKC isoforms appear to play a role in the regulation of various renal functions and differentiation within specific functional units of the uriniferous tubule in rat kidney.
Adult* ; Animals ; Biological Processes ; Humans ; Kidney* ; Parturition ; Protein Isoforms ; Protein Kinase C beta ; Protein Kinase C* ; Protein Kinases* ; Rats* ; Signal Transduction ; Ureter

Activation of protein kinase C (PKC) is closely linked with endothelial dysfunction. However, the effect of PKCβII on endothelial dysfunction has not been characterized in cultured endothelial cells. Here, using adenoviral PKCβII gene transfer and pharmacological inhibitors, the role of PKCβII on endothelial dysfucntion was investigated in cultured endothelial cells. Phorbol 12-myristate 13-acetate (PMA) increased reactive oxygen species (ROS), p66shc phosphorylation, intracellular adhesion molecule-1, and monocyte adhesion, which were inhibited by PKCβi (10 nM), a selective inhibitor of PKCβII. PMA increased the phosphorylation of CREB and manganese superoxide dismutase (MnSOD), which were also inhibited by PKCβi. Gene silencing of CREB inhibited PMA-induced MnSOD expression, suggesting that CREB plays a key role in MnSOD expression. Gene silencing of PKCβII inhibited PMA-induced mitochondrial ROS, MnSOD, and ICAM-1 expression. In contrast, overexpression of PKCβII using adenoviral PKCβII increased mitochondrial ROS, MnSOD, ICAM-1, and p66shc phosphorylation in cultured endothelial cells. Finally, PKCβII-induced ICAM-1 expression was inhibited by Mito-TEMPO, a mitochondrial ROS scavenger, suggesting the involvement of mitochondrial ROS in PKC-induced vascular inflammation. Taken together, the results suggest that PKCβII plays an important role in PMA-induced endothelial dysfunction, and that the inhibition of PKCβII-dependent p66shc signaling acts as a therapeutic target for vascular inflammatory diseases.
Endothelial Cells* ; Gene Silencing ; Inflammation ; Intercellular Adhesion Molecule-1 ; Mitochondria ; Monocytes ; Phosphorylation ; Protein Kinase C beta* ; Protein Kinase C* ; Protein Kinases* ; Reactive Oxygen Species ; Superoxide Dismutase

OBJECTIVETo investigate the association between cTnI phosphorylation/degradation and cardiomyopathies in extransplanted myocardium.

METHODScTnI phosphorylation and degradation as well as PKC (beta1, beta2) expressions were determined in extransplanted hearts from patients with cardiomyopathies (n = 8) and from traffic accidents (n = 6) by Western blot.

RESULTSThe cTnI bands were observed in LV myocardium of cardiomyopathy patients and normal myocardium while and cTnI degradation bands were only detected in LV myocardium from patients with cardiomyopathies. The phosphorylated cTnI bands were significantly upregulated in LV myocardium of cardiomyopathy patients compared to normal myocardium (P < 0.05). There was no myocardial PKCbeta1, PKCbeta2 expression in all examined hearts.

CONCLUSIONThe cTnI degradation products and increased phosphorylated cTnI expression are likely involved in the pathogenesis and development of cardiomyopathy.

Adult ; Cardiomyopathies ; metabolism ; pathology ; Female ; Humans ; Male ; Middle Aged ; Myocardium ; metabolism ; pathology ; Phosphorylation ; Protein Kinase C ; metabolism ; Protein Kinase C beta ; Signal Transduction ; Troponin I ; metabolism

OBJECTIVETo assess the association between single nucleotide polymorphisms (SNPs) of mannose-binding lectin 2 gene (MBL2) (rs1800450, rs1800451 and rs11003125) and protein kinase C-beta 1 gene (PRKC beta 1) (rs3700106, rs2575390) with diabetic macroangiopathy in northern Chinese Han population.

METHODSThe samples have included 318 type 2 diabetes mellitus (T2DM) patients and 448 normoglycemic controls. The five SNPs were determined by a Multiplex SnaPshot method. Biochemical indices such as fasting plasma-glucose, triglyceride and total cholesterol were also measured. Linkage disequilibrium and haplotype analysis were carried out for all samples using Haploview 4.2. Additive model was applied to assess the effect of interaction between SNPs and environment factors on macrovascular complications.

RESULTSGenotypic frequencies of rs11003125 have differed significantly between the controls and patients with coronary heart disease and peripheral vascular disease (P=0.024 and 0.004, respectively). The allele frequency of rs11003125 was also statistically significant between the two groups (P=0.014 and 0.001, respectively). Compared with patients without macrovascular complications, the allele frequency of rs11003125 was significantly different in patients with peripheral vascular disease (P=0.031). No significant differences were found between the distribution of the genotype frequency and allele frequencies of other variants. Haplotype analysis indicated that, compared with controls and patients without macrovascular complications, individuals with G allele of rs1800450 and C allele of rs11003125 had a higher risk for macrovascular complications.

CONCLUSIONThe rs11003125 polymorphism located in the promoter region of MBL2 gene is associated with macrovascular complications of T2DM in northern Chinese Han population. G allele of rs1800450 and C allele of rs11003125 may be risk factors for macrovascular complications. There were additive interactive effects for rs11003125 polymorphism (GC+CC) and hypertension, diabetic nephropathy, diabetic neuropathy and diabetic retinopathy on macrovascular complications.

Alleles ; China ; ethnology ; Diabetes Mellitus, Type 2 ; ethnology ; genetics ; Diabetic Angiopathies ; ethnology ; genetics ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Humans ; Mannose-Binding Lectin ; genetics ; Polymorphism, Single Nucleotide ; Promoter Regions, Genetic ; Protein Kinase C ; genetics ; Protein Kinase C beta

OBJECTIVETo review the update research progress about the treatment of diabetic macular edema and to give helpful guidelines in the treatment of diabetic macular edema based on available evidence to date.Data sources A literature search of all English articles was performed on the online electronic PubMed database dated 1984 to 2009. The keywords searched included: macular edema, therapy, laser coagulation, intravitreal triamcinolone acetonide, vascular endothelial growth factor inhibitor, protein kinase C inhibitor and Pars plana vitrectomy. After finding relevant articles within these search limits, a manual search was conducted through the references from these articles.Study selection Original articles and critical reviews were reviewed and selected to address the stated purpose.

RESULTSTo date, demonstrated means to reduce the risk of vision loss from diabetic macular edema include focal/grid laser photocoagulation and improved metabolic control. Emerging pharmacologic therapies (intravitreal triamcinolone acetonide, vascular endothelial growth factor inhibitors and protein kinase C beta-isoform inhibitors) and Pars plana vitrectomy have shown early promise in the treatment of diabetic macular edema.

CONCLUSIONSAs there has been extensive development in multiple treatments of diabetic macular edema, choice of the most suitable treatment for specific patients becomes important. Combination therapy of laser, pharmacological and surgical treatment modalities may offer an alternative to treatment of diabetic macular edema.

Diabetic Retinopathy ; therapy ; Humans ; Laser Coagulation ; Macular Edema ; therapy ; Protein Kinase C ; antagonists & inhibitors ; Protein Kinase C beta ; Triamcinolone Acetonide ; administration & dosage ; Vascular Endothelial Growth Factor A ; antagonists & inhibitors ; Vitrectomy

The purpose of this study is to investigate the effect of chelerythrine on the hypertrophy of cardiomyocytes of neonatal rats induced by different glucose levels and its mechanism. Using cultured neonatal ventricular myocytes as a model, groups were divided as: control (5 mmol x L(-1)); high glucose level (10, 15, 20, and 25.5 mmol x L(-1)); high glucose level (25.5 mmol x L(-1)) add different concentrations of chelerythrine (1 and 8 micromol x L(-1)); and control glucose level (5 mmol x L(-1)) add different concentrations of chelerythrine (1 and 8 micromol x L(-1)). Different groups of cardiomyocytes after adding corresponding treat factors were cultured for 48 hours. Cardiomyocytes' diameters and protein level were measured and the expression of PKC-alpha, PKC-beta2, p-PKC-alpha, and p-PKC-beta2 were measured by Western blotting. Compared with control group, neonatal myocytes cultured in high glucose levels showed increased cellular volumes, protein level and expression of PKC-alpha, PKC-beta2, p-PKC-alpha, p-PKC-beta2. When chelerythrine was added, cellular volumes, protein level and expression of PKC-alpha, PKC-beta2, p-PKC-alpha, p-PKC-beta2 were significantly reduced. But in 1 micromol x L(-1) chelerythrine group, the expression of PKC-beta2 was not significantly reduced. The result suggested that chelerythrine can reverse the hypertrophy induced by different glucose levels on the cardiac myocytes, it may have protective effect against diabetic cardiomyopathy via PKC passageway.
Animals ; Animals, Newborn ; Benzophenanthridines ; pharmacology ; Cells, Cultured ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Dose-Response Relationship, Drug ; Glucose ; administration & dosage ; Hypertrophy ; chemically induced ; pathology ; Hypoglycemic Agents ; pharmacology ; Myocytes, Cardiac ; drug effects ; pathology ; Phosphorylation ; Protein Kinase C ; antagonists & inhibitors ; metabolism ; Protein Kinase C beta ; Protein Kinase C-alpha ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the molecular mechanisms of nm23-H1 for regulating PKC signal pathway before and after transfection with nm23-H1 gene.

METHODSUsing Western-blot, Boyden-chamber, MTT and laser scanning confocal microscopy (LSCM) techniques to detect the distribution of PKC in cytosol and plasma membrane, changes of invasion and proliferation activity, PKC translocation status and changes of intracellular Ca(2+) concentration among different human pulmonary carcinoma cells with transfected or untransfected nm23-H1 gene, and changes of the three cell lines after treatment with Calphostin C, a PKC inhibitor.

RESULTS(1) The expression of PKCalpha, PKCbeta II on L9981 and L9981-pLXSN cell membrane, which was in activated status, was remarkably higher than those in L9981-nm23-H1 cell line (P < 0.001). The expression of PKCalpha, PKCbeta II in cytosol in L9981 and L9981-pLXSN cell lines, which was in inactivated status, was lower than those in L9981-nm23-H1 cell line (P < 0.001). It means that the PKC signal pathway was activated in L9981 and L9981-pLXSN cell lines. (2) PKCalpha and PKCbeta II mainly located in nuclei and perinuclear area in L9981 and L9981-pLXSN cells, which were in active status, and the Ca(2+) concentration in these cells was obviously higher than that in L9981-nm23-H1 cell line (P < 0.01). In L9981-nm23-H1 cell line, which was transfected with nm23-H1 gene, PKCalpha and PKCbeta II mainly located in soluble cytosolic section, in an inactive status. (3) The invasion and proliferation ability of L9981 and L9981-pLXSN lung cancer cells was higher than that of L9981-nm23-H1 cell line (P < 0.001). There was no statistically significant difference between L9981 and L9981-pLXSN cell lines (P > 0.05). (4) After treated with PKC inhibitor Calphstin C, the expression of PKC and PKCbeta II in membrane in L9981 and L9981-pLXSN cell lines was down-regulated (P < 0.001), PKCalpha and PKCbeta II were mainly located in cytosolic area, mainly in an inactive status, and the Ca(2+) concentration was found to be decreased in all the three cell lines. The invasion and proliferation ability of the three lung cancer cell lines were obviously decreasing (P < 0.001). However, the invasion and proliferation ability of L9981-nm23-H1 lung cancer cell line was still lower than that of L9981 and L9981-pLXSN lung cancer cell lines (P < 0.001). There was also no significant difference between L9981 and L9981-pLXSN cell lines (P > 0.05).

CONCLUSIONThe results of this study suggest that nm23-H1 gene might inhibit the invasion and metastasis of lung cancer cells by down-regulating PKC signaling pathway. The Ca(2+) in cells might be involved in this process.

Calcium ; metabolism ; Cell Line, Tumor ; Cell Membrane ; metabolism ; Cell Proliferation ; drug effects ; Cytosol ; metabolism ; Down-Regulation ; Humans ; Lung Neoplasms ; enzymology ; metabolism ; pathology ; NM23 Nucleoside Diphosphate Kinases ; genetics ; Naphthalenes ; pharmacology ; Neoplasm Invasiveness ; Protein Kinase C ; antagonists & inhibitors ; metabolism ; Protein Kinase C beta ; Protein Kinase C-alpha ; metabolism ; Signal Transduction ; Transfection

Type 1 diabetes mellitus (T1DM)-induced cognitive dysfunction is common, but its underlying mechanisms are still poorly understood. In this study, we found that knockout of conventional protein kinase C (cPKC)γ significantly increased the phosphorylation of Tau at Ser214 and neurofibrillary tangles, but did not affect the activities of GSK-3β and PP2A in the hippocampal neurons of T1DM mice. cPKCγ deficiency significantly decreased the level of autophagy in the hippocampal neurons of T1DM mice. Activation of autophagy greatly alleviated the cognitive impairment induced by cPKCγ deficiency in T1DM mice. Moreover, cPKCγ deficiency reduced the AMPK phosphorylation levels and increased the phosphorylation levels of mTOR in vivo and in vitro. The high glucose-induced Tau phosphorylation at Ser214 was further increased by the autophagy inhibitor and was significantly decreased by an mTOR inhibitor. In conclusion, these results indicated that cPKCγ promotes autophagy through the AMPK/mTOR signaling pathway, thus reducing the level of phosphorylated Tau at Ser214 and neurofibrillary tangles.
AMP-Activated Protein Kinases/metabolism* ; Animals ; Autophagy ; Diabetes Mellitus, Type 1 ; Glucose ; Glycogen Synthase Kinase 3 beta/metabolism* ; Mice ; Phosphorylation ; Protein Kinase C/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; tau Proteins/metabolism*

The effects of phorbol esters were studied in rabbit carotid artery to evaluate the action of protein kinase C on the regulation of vascular tone by isoproterenol. The vascular rings, 2 mm in width, were myographied isometrically in an isolated organ bath and the effects of phorbol 12,13-dibutyrate(PDBu) and phorbol 12-myristate 13-acetate(PMA) were determined. Isoproterenol, a beta adrenergic agonist, relaxed the vessel which was precontracted by phenylephrine, but not that by phorbol esters. The action of isoproterenol was attenuated by removal of endothelium or pretreatment with methylene blue or nitro-L-arginine. The pretreatment with phorbol esters at concentrations which did not induce contraction, decreased isoproterenol-induced relaxation of vascular rings with or without endothelium. The action of PDBu on isoproterenol-induced relaxation was less effective than that of PMA, unlike those observed in contractile response, but the contractile effect of the former was more potent than that of the latter. PMA did not affect relaxant effect of forskolin, an activator of adenyl cyclase. Staurosporine, a protein kinase C inhibitor, inhibited the action of these drugs on both isoproterenol-induced relaxation and the contractile response. These results suggest that the relaxation induced by isoproterenol was reducd by the activation of protein kinase C, which may be isozyme different from that involved in contractile response.
Adenylyl Cyclases ; Adrenergic beta-Agonists ; Baths ; Carotid Arteries ; Colforsin ; Endothelium ; Isoproterenol* ; Methylene Blue ; Muscle, Smooth, Vascular* ; Phenylephrine ; Phorbol Esters* ; Protein Kinase C ; Relaxation ; Staurosporine

Proto-Oncogene Proteins c-akt/metabolism* ; Butyrates ; Ligands ; Glucose ; Receptors, G-Protein-Coupled/metabolism* ; Glycogen Synthase Kinases/metabolism* ; Glycogen Synthase Kinase 3 beta ; Phosphorylation