Therapeutic mechanism of Guizhi Gancao Decoction for heart failure: a network pharmacology-based analysis / 南方医科大学学报

OBJECTIVE@#To predict the targets and pathways in the therapeutic mechanism of Guizhi Gancao Decoction (GZGCD) against heart failure (HF) based on network pharmacology.@*METHODS@#The chemical components of GZGCD were analyzed using the databases including TCMSP, TCMID and TCM@Taiwan, and the potential targets of GZGCD were predicted using the SwissTargetPrediction database. The targets of HF were obtained using the databases including DisGeNET, Drugbank and TTD. The intersection targets of GZGCD and HF were identified using VENNY. Uniport database was used to convert the information, and the components-targets-disease network was constructed using Cytoscape software. The Bisogene plug-in, Merge plug-in, and CytoNCA plug-in in Cytoscape software were used for protein-protein interaction (PPI) analysis to acquire the core targets. Metascape database was used for GO and KEGG analysis. The results of network pharmacology analysis were verified with Western blot analysis. Three factors (PKCα, ERK1/2 and BCL2) were screened according to the degree value of network pharmacology results and the degree of correlation with heart failure process. The pentobarbtal sodium was dissolvein H9C2 cells treated with serum-free high glucose medium to simulate the ischemic anoxic environment of heart failure. The total proteins of myocardial cells were extracted. The protein contents of PKCα, ERK1/2 and BCL2 were determined.@*RESULTS@#We identified a total of 190 intersection targets between GZGCD and HF using Venny database, involving mainly the circulatory system process, cellular response to nitrogen compounds, cation homeostasis, and regulation of the MAPK cascade. These potential targets were also involved in 38 pathways, including the regulatory pathways in cancer, calcium signal pathway, cGMP-PKG signal pathway, and cAMP signal pathway. Western blot analysis showed that in an in vitro H9C2 cell model of HF, treatment with GZGCD downregulated PKCα and ERK1/2 expressions and upregulated BCL2 expression.@*CONCLUSION@#The therapeutic mechanism of GZGCD for HF involves multiple targets including PRKCA, PRKCB, MAPK1, MAPK3, and MAPK8 and multiple pathways including the regulatory pathway in cancer and the calcium signaling pathway.

PLCE1 Promotes the Invasion and Migration of Esophageal Cancer Cells by Up-Regulating the PKCα/NF-κB Pathway

PURPOSE: To investigate the effect and mechanism of phospholipase C epsilon gene 1 (PLCE1) expression on esophageal cancer cell lines. MATERIALS AND METHODS: The esophageal carcinoma cell lines Eca109 and EC9706 and normal esophageal epithelial cell line HEEC were cultured. The expression of PLCE1, protein kinase C alpha (PKCα), and nuclear factor kappa B (NF-κB) p50/p65 homodimer in cells were comparatively analyzed. The esophageal cancer cells were divided into si-PLCE1, control siRNA (scramble), and mock groups that were transfected with specific siRNA for PLCE1, control siRNA, and blank controls, respectively. Expression of PLCE1, PKCα, p50, and p65 was detected by Western blotting. Transwell assay was used to detect migration and invasion of Eca109 and EC9706 cells. RESULTS: Compared with HEEC, the expression of PLCE1, PKCα, p50, and p65 was increased in Eca109 and EC9706 cells. The expression of PLCE1 was positively correlated with the expression of PKCα and p50 (PKCα: r=0.6328, p=0.032; p50: r=0.6754, p=0.041). PKCα expression had a positive correlation with the expression of p50 and p65 (p50: r=0.9127, p=0.000; p65: r=0.9256, p=0.000). Down-regulation of PLCE1 significantly decreased the expression of PKCα and NF-κB-related proteins (p65: p=0.002, p=0.004; p50: p=0.005, p=0.009) and inhibited the migration and invasion of Eca109 and EC9706 cells. CONCLUSION: PLCE1 activated NF-κB signaling by up-regulating PKCα, which could promote invasion and migration of esophageal cancer cells.

Different subtypes of estrogen receptor α and related signal molecules in the hippocampus are associated with spatial cognitive impairment of diabetic mice / 生理学报

To study the correlation between the spatial cognitive impairment and different subtypes of estrogen receptor α (ERα) of hippocampus in diabetic mice, we used alloxan (intraperitoneal injection) to induce type 1 diabetes in male Kunming mice and compared the spatial cognitive ability of the model mice with that of control mice through Morris water maze test. Meanwhile, using Western blot, we detected the protein expressions of ER-α36, ER-α66, caveolin-1, PKCα, cAMP-response element binding protein 2 (CREB2), and synaptophysin (Syn) in the hippocampus of the mice. The results showed that on the 3rd and 5th days of training, the ability of spatial learning and memory in the diabetic mice was significantly inferior to that of the control mice (P < 0.05). In the diabetic mice, the protein expressions of caveolin-1 and PKCα were decreased (P < 0.05), but ER-α66 expression was unaffected, while ER-α36 and CREB2 expressions were significantly increased (P < 0.05) compared with those of the control mice. The results suggest that abnormal expression of ER-α36 and related signal molecules may be important factors for diabetes-induced spatial cognitive impairment.

Roles of PKCα on the biological functions of T cells / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the roles of PKCα on the proliferation, apoptosis, differentiation, cytokine production and inducible regulatory T cell (iTreg) induction of T cells.</p><p><b>METHODS</b>T cells from WT (PKCα⁺/⁺) or PKCα knockout (PKCα⁻/⁻) mice were isolated and cultured in vitro. T cell proliferation and apoptosis were determined using ³H thymidine incorporation and CSFE/Annexin V staining. Cytokines production (IL-2, IL-4, IFN-γ and IL-17) was detected using ELISA. CD4⁺T cells were isolated and cultured in vitro via Th17 or iTreg biased condition. Flow cytometry was used to detect the cell differentiation.</p><p><b>RESULTS</b>The production of IL-2 upon TCR stimulation increased, while the contents of IL-4 and IL-17 decreased in the PKCα⁻/⁻ group compared with the PKCα⁺/⁺ group. The differentiation rate of Th17 cells decreased, while the iTreg production increased in the PKCα⁻/⁻ group compared with the PKCα⁺/⁺ group.</p><p><b>CONCLUSIONS</b>PKC-α is proinflammatory.</p>

Dimethyl Cardamonin Exhibits Anti-inflammatory Effects via Interfering with the PI3K-PDK1-PKCalpha Signaling Pathway

Consumption of herbal tea [flower buds of Cleistocalyx operculatus (Roxb.) Merr. et Perry (Myrtaceae)] is associated with health beneficial effects against multiple diseases including diabetes, asthma, and inflammatory bowel disease. Emerging evidences have reported that High mobility group box 1 (HMGB1) is considered as a key "late" proinflammatory factor by its unique secretion pattern in aforementioned diseases. Dimethyl cardamonin (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone, DMC) is a major ingredient of C. operculatus flower buds. In this study, the anti-inflammatory effects of DMC and its underlying molecular mechanisms were investigated on lipopolysaccharide (LPS)-induced macrophages. DMC notably suppressed the mRNA expressions of TNF-alpha, IL-1beta, IL-6, and HMGB1, and also markedly decreased their productions in a time- and dose-dependent manner. Intriguingly, DMC could notably reduce LPS-stimulated HMGB1 secretion and its nucleo-cytoplasmic translocation. Furthermore, DMC dose-dependently inhibited the activation of phosphatidylinositol 3-kinase (PI3K), phosphoinositide-dependent kinase 1 (PDK1), and protein kinase C alpha (PKCalpha). All these data demonstrated that DMC had anti-inflammatory effects through reducing both early (TNF-alpha, IL-1beta, and IL-6) and late (HMGB1) cytokines expressions via interfering with the PI3K-PDK1-PKCalpha signaling pathway.

Effects of sevoflurane on tight junction protein expression and PKC-alpha translocation after pulmonary ischemia-reperfusion injury

Pulmonary dysfunction caused by ischemia-reperfusion injury is the leading cause of mortality in lung transplantation. We aimed to investigate the effects of sevoflurane pretreatment on lung permeability, tight junction protein occludin and zona occludens 1 (ZO-1) expression, and translocation of protein kinase C (PKC)-alpha after ischemia-reperfusion. A lung ischemia-reperfusion injury model was established in 96 male Wistar rats following the modified Eppinger method. The rats were divided into four groups with 24 rats in each group: a control (group C), an ischemia-reperfusion group (IR group), a sevoflurane control group (sev-C group), and a sevoflurane ischemia-reperfusion group (sev-IR group). There were three time points in each group: ischemic occlusion for 45 min, reperfusion for 60 min and reperfusion for 120 min; and there were six rats per time point. For the 120-min reperfusion group, six extra rats underwent bronchoalveolar lavage. Mean arterial pressure (MAP) and pulse oxygen saturation (SpO2) were recorded at each time point. The wet/dry weight ratio and lung permeability index (LPI) were measured. Quantitative RT-PCR and Western blot were used to measure pulmonary occludin and ZO-1, and Western blot was used to measure cytosolic and membranous PKC-alpha in the lung. Lung permeability was significantly increased after ischemia-reperfusion. Sevoflurane pretreatment promoted pulmonary expression of occludin and ZO-1 after reperfusion and inhibited the translocation of PKC-alpha. In conclusion, sevoflurane pretreatment alleviated lung permeability by upregulating occludin and ZO-1 after ischemia-reperfusion. Sevoflurane pretreatment inhibited the translocation and activation of PKC-alpha, which also contributed to the lung-protective effect of sevoflurane.

Purple urine bag syndrome in end-stage chronic kidney disease

Introduction: When faced with violet, purple or purplish-blue urine, clinicians should consider urinary tract infection in their differential diagnosis. Case report: A 60-year-old woman with end-stage kidney disease and non-adherence to renal replacement therapy was admitted to our hospital for placement of hemodialysis catheter. During her hospitalization she had purple urine, and purple urine bag syndrome (PUBS) was diagnosed. She was effectively treated with antibiotics and her urine returned to a dark yellow color. Discussion: Although this condition is often easily treated, diagnosing PUBS in chronic renal patients probably means an increased serum concentration of indoxyl sulfate, metabolite that is involved in the progression of both CKD and cardiovascular disease. Conclusion: Hence, in the context of our renal patients, perhaps PUBS is not as benign as supposed. .

Preeclampsia serum-induced collagen I expression and intracellular calcium levels in arterial smooth muscle cells are mediated by the PLC-gamma1 pathway

In women with preeclampsia (PE), endothelial cell (EC) dysfunction can lead to altered secretion of paracrine factors that induce peripheral vasoconstriction and proteinuria. This study examined the hypothesis that PE sera may directly or indirectly, through human umbilical vein ECs (HUVECs), stimulate phospholipase C-gamma1-1,4,5-trisphosphate (PLC-gamma1-IP3) signaling, thereby increasing protein kinase C-alpha (PKC-alpha) activity, collagen I expression and intracellular Ca2+ concentrations ([Ca2+]i) in human umbilical artery smooth muscle cells (HUASMCs). HUASMCs and HUVECs were cocultured with normal or PE sera before PLC-gamma1 silencing. Increased PLC-gamma1 and IP3 receptor (IP3R) phosphorylation was observed in cocultured HUASMCs stimulated with PE sera (P<0.05). In addition, PE serum significantly increased HUASMC viability and reduced their apoptosis (P<0.05); these effects were abrogated with PLC-gamma1 silencing. Compared with normal sera, PE sera increased [Ca2+]i in cocultured HUASMCs (P<0.05), which was inhibited by PLC-gamma1 and IP3R silencing. Finally, PE sera-induced PKC-alpha activity and collagen I expression was inhibited by PLC-gamma1 small interfering RNA (siRNA) (P<0.05). These results suggest that vasoactive substances in the PE serum may induce deposition in the extracellular matrix through the activation of PLC-gamma1, which may in turn result in thickening and hardening of the placental vascular wall, placental blood supply shortage, fetal hypoxia-ischemia and intrauterine growth retardation or intrauterine fetal death. PE sera increased [Ca2+]i and induced PKC-alpha activation and collagen I expression in cocultured HUASMCs via the PLC-gamma1 pathway.

Effect of m-calpain in PKCα-mediated proliferation of pulmonary artery smooth muscle cells by low dose of ouabain.

There is growing evidence that ouabain, a cardiotonic steroid may promote growth of cardiac and vascular myocytes, indicating its novel role in cell growth and proliferation, without appreciable inhibition of the sodium pump. The mechanism(s) by which low dose of ouabain produces pulmonary artery smooth muscle cell proliferation, a prerequisite for right ventricular hypertrophy, is currently unknown. Here, we analyzed the effects of low dose of ouabain (10 nM) on increase in [Ca2+]i, m-calpain and protein kinase C (PKC) activities on pulmonary artery smooth muscle cell proliferation and determined their sequential involvement in this scenario. We treated bovine pulmonary artery smooth muscle cells with a low dose of ouabain (10 nM) and determined [Ca2+]i in the cells by fluorometric assay using fura2-AM, m-calpain activity by fluorometric assay using SLLVY-AMC as the substrate, PKC activity using an assay kit and assay of Na+/K+ATPase activity spectrophotometrically. We purified m-calpain and PKCα by standard chromatographic procedure by HPLC and then studied cleavage of the purified PKCα by m-calpain using Western immunoblot method. Subsequently, we performed cell proliferation assay utilizing the redox dye resazunin. We used selective inhibitors of [Ca2+]i (BAPTA-AM), m-calpain (MDL28170), PKCα (Go6976) and determined their involvement in ouabain (10 nM)-mediated smooth muscle cell proliferation. Our results suggested that treatment of bovine pulmonary artery smooth muscle cells with a low dose of ouabain (10 nM) increased [Ca2+]i and subsequently stimulated m-calpain activity and proteolytically activated PKCα in caveolae (signaling microdomain also known as signalosomes) of the cells. Upon activation, PKCα increased the smooth muscle cell proliferation via Go/G1 to S/G2-M phase transition. Thus, [Ca2+]i-mCalpain-PKCα signaling axis plays a crucial role during low dose of ouabain-mediated pulmonary artery smooth muscle cell proliferation.

Effects and mechanisms of the functional parts of Dahuang Zhechong pill containing serum on platelet-derived growth factor-stimulated proliferation of vascular smooth muscle cells / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate and compare the effects and mechanisms of three functional parts of Dahuang Zhechong Pill (DHZCP), including drugs with the function of removing blood stasis and promoting blood circulation (FP-I), drugs with the function of expelling heat and moistening dryness (FP-II), and drugs with the function of nourishing yin and replenishing blood (FP-III) of DHZCP, on platelet-derived growth factor (PDGF)-stimulated vascular smooth muscle cells (VSMCs) proliferation with the method of serum pharmacology.</p><p><b>METHODS</b>VSMCs proliferation of rat was assayed by measuring the cell viability with the 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) method. DNA synthesis in VSMCs was examined by detecting 5'-bromo-2'-deoxyuridine incorporation with the immunocytochemical method. Cycle of VSMCs was evaluated with flow cytometry. Expression of cyclin D1, p27, PKCα, and phosphorylated extracellular signal regulated kinase 1/2 (ERK1/2) was quantified by the Western blotting method.</p><p><b>RESULTS</b>The FP-I and FP-III containing serum was capable of inhibiting PDGF-stimulated proliferation and DNA synthesis of VSMCs, arrested VSMCs in G phase, downregulated cyclin D1, and upregulated p27 expression (P <0.01 or P <0.05). The FP-I and FP-III containing serum also inhibited the PDGF-induced phosphorylation of tyrosine of ERK1/2 and PKCα expression (P <0.01 or P <0.05).</p><p><b>CONCLUSIONS</b>FP-I and FP-III of DHZCP are able to inhibit VSMCs proliferation via interrupting PKCα-ERK1/2 signaling, modulating the expression of cell cycle proteins to result in arresting the cells in G phase. The inhibitory effect is mainly related to the function of removing blood stasis and promoting blood circulation, slightly to the function of nourishing yin and replenishing blood, but not to the function of expelling heat and moistening dryness.</p>

Expressions of COX-2, PKC-α and miR-101 in gastric cancer and their correlations / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expressions of miR-101, protein kinase C-α (PKC-α), and cyclooxygenase-2 (COX-2) in gastric cancer (GC) tissue and their correlations.</p><p><b>METHODS</b>RT-qPCR was used to examine miR-101 expression and Western blotting employed to detect PKC-α and COX-2 expressions in 57 cases of gastric cancer tissues and paired normal gastric mucosal tissues.</p><p><b>RESULTS</b>The gastric cancer tissues showed a significantly lower miR-101 expression (Z=6.102, P<0.05) but significantly higher expressions of COX-2 (Z=14.436, P<0.05) and PKC-α (Z=6.955, P<0.05) than the normal gastric tissues. The expression of COX-2 protein was significantly correlated with the degree of differentiation, invasion depth, lymph node metastasis and TNM stage (P<0.05); PKC-α protein expression was associated with lymph node metastasis and TNM stage (P<0.05). PKC-α expression was positively correlated (r=0.531, P<0.05) and miR-101 expression negatively correlated (r=-0.627, P<0.05) with COX-2 expression in gastric cancer tissues.</p><p><b>CONCLUSIONS</b>miR-101, PKC-α and COX-2 all play a role in the tumorigenesis and progression of gastric cancer. miR-101 and PKC-α might be new potential therapeutic targets for inhibiting COX-2 in gastric cancer.</p>

miR-216b suppresses cell proliferation and invasion by targeting PKCα in nasopharyngeal carcinoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To elucidate whether miR-216b suppresses cell proliferation and invasion by targeting PKCα, thus to reveal the molecular mechanism that miR-216b functions as a tumor suppressor in nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>PKCα 3'UTR-luciferase vector was constructed and dual-luciferase reporter gene assay was employed to examine the effect of miR-216b on luciferase activity. Nasopharyngeal cancer CNE2 cells were transfected with miR-216b mimics, and then qRT-PCR and Western blotting were performed to detect the expressions of PKCa mRNA and protein. The effects of PKCα downregulation on cell proliferation and invasion were assessed after PKCα siRNA were transfected into CNE2 cells. CNE2 cells were cotransfected with miR-216b mimics and PKCα plasmid, and the proliferation of CNE2 cells was assayed using a MTS cell proliferation assay kit.</p><p><b>RESULTS</b>The results of dual-luciferase reporter gene assay demonstrated that miR-216b could bind to the 3'-untranslated region (UTR) of PKCα and inhibited the luciferase activity to 62.4% of that of the mimics control cells. The expressions of PKCα mRNA and protein were significantly down-regulated by 49.1% and 55.7%, respectively, in comparison with that of the control cells. siRNA-mediated downregulation of PKCα suppressed the proliferation and invasion ability of CNE2 cells, and could partially mimic the tumor-inhibiting effect of miR-216b. Moreover, the overexpressed PKCα may partially reverse the inhibitory effect of miR-216b on proliferation of CNE2 cells.</p><p><b>CONCLUSION</b>miR-216b suppresses cell proliferation and invasion by targeting PKCα in NPC cells.</p>

Effects of aquaporin 4 deficiency on the expression of spinal PKCα, PKCγ and c-Fos in naloxone-precipitated morphine withdrawal mice / 生理学报

The previous study indicated that aquaporin 4 (AQP4) deficiency attenuated opioid physical dependence. However, the underlying mechanism remains unknown. In the present study, the effects of AQP4 deficiency on the expression of three factors, protein kinase C (PKC) α, PKCγ and c-Fos in the spinal cord, which are known to be concerned with spinal neuronal sensitization and opiate dependence, were investigated in AQP4 knockout mice using Western blotting analysis. It was observed that AQP4 deficiency reduced the score of naloxone-precipitated abstinent jumping after repeated morphine administration compared with wild-type (P < 0.001). Meanwhile, the protein levels of PKCα and c-Fos in the spinal cord of AQP4 knockout mice were significantly higher than those in the wild-type mice; while the expression of PKCγ was decreased remarkably by AQP4 knockout during the withdrawal (P < 0.01). These data suggest that AQP4 deficiency-attenuated morphine withdrawal responses may be partially attributed to the changes in the spinal expression of PKCα, PKCγ or c-Fos.

Dahuang zhechong pill containing serum inhibited platelet-derived growth factor-stimulated vascular smooth muscle cells proliferation by inducing G1 arrest partly via suppressing protein kinase C α-extracellular regulated kinase 1/2 signaling pathway / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate effects of dahuang zhechong pill ( DHZCP) on the cell cycle and the related signal pathways in vascular smooth muscle cells (VSMCs) stimulated by platelet-derived growth factor (PDGF) with the method of serum pharmacology.</p><p><b>METHODS</b>DNA synthesis in VSMCs was examined by detecting 5'-bromo-2'-deoxyuridine incorporation with the immunocytochemical method. The cycle of VSMCs was evaluated with flow cytometry. Expressions of cyclin D1, p27, protein kinase Cα (PKCα), and phosphorylated extracellular signal regulated kinase 1/2 (ERK1/2) were quantified by Western blot method.</p><p><b>RESULTS</b>DHZCP containing serum significantly inhibited DNA synthesis of PDGF-stimulated VSMCs, arrested the cells in G G(1) phase, modulated the protein expressions of cyclin D D(1) and p27, and suppressed the activation of PKCα and ERK1/2.</p><p><b>CONCLUSION</b>DHZCP containing serum inhibits VSMCs proliferation via modulating the expressions of cell cycle proteins to arrest the cell in G G(1) phase, which is attributed to, at least in part, suppressing PKCα-ERK1/2 signaling in VSMCs.</p>

Effect of heparin-derived oligosaccharide on vascular smooth muscle cell proliferation through inhibition of PKC-alpha expression / 药学学报

In this study, the effect of heparin-derived oligosaccharide (HDO) on bovine vascular smooth muscle cell (VSMC) proliferation and signal transduction mechanism involved were investigated. The levels of PKC-alpha protein and mRNA were determined by cell-based ELISA, RT-PCR, Western blotting and immunocytochemical methods. Meanwhile, mRNA levels of c-jun, c-myc and c-fos were assayed by RT-PCR method. The results showed that HDO inhibited newborn calf serum (NCS)-induced expression of PKC-alpha and proto-oncogenes, which may be one of the mechanisms for the inhibition of VSMC proliferation by HDO. Flow cytometry analysis indicated that HDO blocked NCS-induced cell cycle progression by arresting cells at G0/G1 phase. The results imply that HDO inhibits VSMC proliferation by moderating the gene level of PKC-alpha, eventually inhibiting proto-oncogene mRNA expression and blocking G1/S transition.

Alcohol-induced proliferation of neurons in mouse hippocampal dentate gyrus: a possible role of ceramide / 生理学报

To investigate the role and mechanism of ceramide (Cer) regulation in alcohol-induced neuronal proliferation and the newborn neurons formation, we used sphingomyelin synthase 2 (predominant enzyme of Cer metabolism) knockout (SMS2(-/-)) and wild type (WT) female mice to establish the model of prenatal alcohol exposure. In 24 h after being given birth (postnatal day 0, P0), the offspring of model mice received blood sphingomyelin (SM) measurement with enzymatic method. On P0, P7, P14 and P30, the proliferation of granule cells in the dentate gyrus and newborn neurons were investigated with immunofluorescent labeling. The expression of protein kinase Cα (PKCα) in the hippocampus was tested with Western blot analysis. The results showed that the SM level of blood in SMS2(-/-) pups was significantly lower than that in WT pups. No matter in SMS2(-/-) or WT mice, the prenatal alcohol exposure down-regulated the SM levels in pups with dose-dependency. In both SMS2(-/-) and WT pups, the number of proliferative neurons and newborn neurons in the dentate gyrus gradually decreased with the growing age. Compared with the WT pups, SMS2(-/-) pups showed significantly more proliferative neurons and newborn neurons in the dentate gyrus. Notably, prenatal alcohol exposure dose-dependently increased proliferative neurons and newborn neurons in the dentate gyrus in both WT and SMS2(-/-) pups. The hippocampal expression of PKCα protein in SMS2(-/-) mice was lower than that in WT mice, and prenatal alcohol exposure could up-regulate the PKCα protein expression in both WT and SMS2(-/-) mice with dose dependency. These results suggest that alcohol exposure during pregnancy can induce the compensatory neural cell proliferation and the production of newborn neurons in offspring, and the Cer-ceramide-1-phosphate (C1P) pathway is involved in alcohol-induced neural cell proliferation. The activation of PKCα may be a key step to start the Cer-C1P pathway and up-regulate the alcohol-induced neural cell proliferation and the newborn neurons formation.

The effect of 5-HD on expression of PKC-alpha in rats of chronic hypoxic pulmonary hypertension / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of mito chondrial K(ATP) channels (mitoK(ATP)) inhibitor 5-hydroxydecanoate(5-HD) on chronic hypoxic pulmonary artery hypertension (CHPAH) rats and its underlying mechanisms.</p><p><b>METHODS</b>Forty-eight male SD rats were equally divided into 4 groups randomly (n=12): normal group, hypoxia group, hypoxia + 5-HD group, hypoxia + Diazoxide group. Except the first group, the other three groups were put into hypoxic [O2 (10.0% +/- 0.3%] and nonrmobaric chamber for four weeks to establish chronic hypoxic model and received different interference. When the interference completed, right heart catheter was used to detect the mean pulmonary arterial pressure (mPAP) of each rat and PKC-alpha mRNA expression in pulmonary arteries was detected by reverse transcription-polymerase chain reaction (RT-PCR) and protein expression by Western blot.</p><p><b>RESULTS</b>(mPAP was much higher in hypoxia group than that in normal group (P < 0.01) while in hypoxia + 5-HD group and hypoxia + diazoxide were decreased significantly compared to hypoxia group (P < 0.01). (2) The protein and mRNA levels of PKC-alpha in the hypoxic group were higher than those in normal group (P < 0.05).</p><p><b>CONCLUSION</b>5-HD plays a protective role on CHPAH. The mechanism of its effect may be attributed to inhibiting MitoK(ATP).</p>

Immunohistochemical localization of cyclic AMP-responsive element binding protein (CREB)-binding protein in the pig retina during postnatal development / 대한해부학회지

This study evaluated the cellular localization of cyclic AMP-responsive element binding protein-binding protein (CBP) expression in pig retinas during postnatal development. Immunohistochemistry and Western blot analysis were performed on retinal tissue from 2-day-old, 5-week-old, and 6-month-old pigs. Western blot analysis detected the expression of CBP in the retinas of 2-day-old piglets and showed that it was significantly decreased in the retinas of 5-week-old and 6-month-old pigs. Immunohistochemically, CBP was intensely immunostained in protein kinase C alpha (PKCalpha)-positive-bipolar cells, glutamine synthetase-positive Muller cells, and in ganglion cells in 2-day-old piglets. CBP was detected weakly in the inner plexiform, outer nuclear, and rod and cone layers. CBP immunoreactivity in the ganglion cell layer was decreased in the retinas of 5-week-old and 6-month-old pigs, while clear CBP expression detected in the neurite of PKCalpha-positive bipolar cells in the inner nuclear layer. In addition, CBP immunoreactivity in Muller cells and glial fibrillary acidic protein-positive glial processes was particularly noteworthy in pig retinas, but not in rat retinas. The results indicate that CBP is expressed differentially in the retinal neurons and glial cells according to growth and animal species, and may play an important role in homeostasis in Muller cells, neurite extention in bipolar cells, and signal transduction in photoreceptor cells in the porcine retina.

Angiotropic metastatic malignant melanoma in a canine mammary gland / 한국실험동물학회지

An eleven-year-old spayed female Yorkshire Terrier presented with a sublumbar mass and upon ultrasonographic examination, was revealed to have a mammary gland tumor. Black to reddish colored masses, located in the visceral peritoneum of the sublumbar region was observed on laparotomy with masectomy of the right side. In the laparotomy, we observed reddish masses multifocally located in the serosal membrane of the large intestine. Histopathologic examination of the intestinal and abdominal mass showed highly invasiveness into the muscle and metastasis of melanocytic tumor cells through the blood vessels. The mammary glands showed abnormal hyperplasia of melanocytes, destruction of the normal glands by tumor cells and infiltration of some lymphocytes in the pool of melanocytic cells. We have identified a malignant melanoma containing an angiotumoral complex in which tumor cells occupied a pericytic location along the microvessels with intravasation determined by immunohistochemistry for S100 protein and protein kinase C-alpha. Histologic findings in this dog lead to a diagnosis of an angiotropic metastatic malignant melanoma.

PKC isoform selectivity and radiation-induced apoptosis of HepG2 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expressions of protein kinase C (PKC) isoforms in X-ray-exposed HepG2 cells and identify the PKC isoforms that induce radioresistance in HepG2 cells.</p><p><b>METHODS</b>Cultured HepG2 cells were divided into control group and 6 Gy radiation group for corresponding treatments. The fluorescence intensity (FI) and the percentage of positive cells were determined using flow cytometry.</p><p><b>RESULTS</b>The FI of PKCalpha and PKCdelta were 2.28 and 5.05 in the radiation group, respectively, significantly higher than those in the control group (P<0.05). The percentages of PKCalpha- and PKCdelta -positive cells were significantly higher in the radiation group than in the control group (P<0.05). The FI and the percentages of PKC zeta, gamma, epsilon, zeta positive cells were rather low and showed no significant differences between the two groups (P>0.05); PKCbeta expression was not detected in the two groups of cells. The apoptosis rates of the control and radiation groups were 1.73% and 20.90%, respectively.</p><p><b>CONCLUSION</b>PKCalpha and PKCdelta may be involved in protecting HepG2 cells from radiation-induced apoptosis.</p>