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1.
Nat Commun ; 11(1): 4752, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958754

RESUMO

Growth hormone (GH) is a key modulator of growth and GH over-secretion can lead to gigantism. One form is X-linked acrogigantism (X-LAG), in which infants develop GH-secreting pituitary tumors over-expressing the orphan G-protein coupled receptor, GPR101. The role of GPR101 in GH secretion remains obscure. We studied GPR101 signaling pathways and their effects in HEK293 and rat pituitary GH3 cell lines, human tumors and in transgenic mice with elevated somatotrope Gpr101 expression driven by the rat Ghrhr promoter (GhrhrGpr101). Here, we report that Gpr101 causes elevated GH/prolactin secretion in transgenic GhrhrGpr101 mice but without hyperplasia/tumorigenesis. We show that GPR101 constitutively activates not only Gs, but also Gq/11 and G12/13, which leads to GH secretion but not proliferation. These signatures of GPR101 signaling, notably PKC activation, are also present in human pituitary tumors with high GPR101 expression. These results underline a role for GPR101 in the regulation of somatotrope axis function.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Gigantismo/metabolismo , Hormônio do Crescimento/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Acromegalia/metabolismo , Acromegalia/patologia , Animais , Composição Corporal , Linhagem Celular , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Gigantismo/patologia , Adenoma Hipofisário Secretor de Hormônio do Crescimento/genética , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Adenoma Hipofisário Secretor de Hormônio do Crescimento/patologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação , Hipófise/metabolismo , Proteína Quinase C/metabolismo , Ratos , Receptores Acoplados a Proteínas-G/genética
2.
PLoS One ; 15(8): e0237591, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32833978

RESUMO

The slow cardiac delayed rectifier current (IKs) is formed by KCNQ1 and KCNE1 subunits and is one of the major repolarizing currents in the heart. Decrease of IKs currents either due to inherited mutations or pathological remodeling is associated with increased risk for cardiac arrhythmias and sudden death. Ca2+-dependent PKC isoforms (cPKC) are chronically activated in heart disease and diabetes. Recently, we found that sustained stimulation of the calcium-dependent PKCßII isoform leads to decrease in KCNQ1 subunit membrane localization and KCNQ1/KCNE1 channel activity, although the role of KCNE1 in this regulation was not explored. Here, we show that the auxiliary KCNE1 subunit expression is necessary for channel internalization. A mutation in a KCNE1 phosphorylation site (KCNE1(S102A)) abolished channel internalization in both heterologous expression systems and cardiomyocytes. Altogether, our results suggest that KCNE1(S102) phosphorylation by PKCßII leads to KCNQ1/KCNE1 channel internalization in response to sustained PKC stimulus, while leaving KCNQ1 homomeric channels in the membrane. This preferential internalization is expected to have strong impact on cardiac repolarization. Our results suggest that KCNE1(S102) is an important anti-arrhythmic drug target to prevent IKs pathological remodeling leading to cardiac arrhythmias.


Assuntos
Cálcio/metabolismo , Canal de Potássio KCNQ1/metabolismo , Miócitos Cardíacos/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Proteína Quinase C/metabolismo , Animais , Feminino , Células HEK293 , Humanos , Canal de Potássio KCNQ1/genética , Mutação , Miócitos Cardíacos/citologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Proteína Quinase C/genética , Ratos
3.
PLoS One ; 15(7): e0236175, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32697798

RESUMO

Adenoviruses cause upper respiratory infections, conjunctivitis, keratitis, and gastrointestinal illness. These can be fatal in immunocompromised individuals. Adenoviruses have also been engineered into viral vectors to deliver therapeutic genes or induce immunity as vaccine carriers. The success of ocular gene therapy is driven partly by the immunologic and biochemical influences of the intraocular environment. We have shown that versican and hyaluronan modulate adenoviral vector transgene expression through CD44 signaling. Herein we explored the role of these pathways on virus replication and viral protein expression of wild type adenovirus. We report that the addition of vitreous humor (which contains both versican and hyaluronan) increases viral hexon protein levels. Vitreous humor also increased wild type adenovirus DNA replication in vitro. Metalloproteinase and γ-secretase inhibitors, which inhibit CD44 proteolytic activation, blocked adenoviral replication in vitro. Similarly, protein kinase C and RhoA kinase inhibitors, both proteins associated with CD44 mediated pathways, also inhibited wild type adenoviral replication in vitro. Application of metalloproteinase and γ-secretase inhibitors to human conjunctival explants sharply decreased adenoviral vector gene expression. Our results demonstrate that pharmacologic delivery of these inhibitors is easily achievable. The inhibition of these enzymes should be explored as potential therapies of wild type adenoviral infections.


Assuntos
Infecções por Adenoviridae/tratamento farmacológico , Adenoviridae/efeitos dos fármacos , Antivirais/farmacologia , Vetores Genéticos/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Adenoviridae/fisiologia , Infecções por Adenoviridae/virologia , Administração Oftálmica , Amidas/farmacologia , Amidas/uso terapêutico , Antivirais/uso terapêutico , Túnica Conjuntiva/metabolismo , DNA Viral/genética , DNA Viral/isolamento & purificação , Diaminas/farmacologia , Diaminas/uso terapêutico , Dipeptídeos/farmacologia , Dipeptídeos/uso terapêutico , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Vetores Genéticos/fisiologia , Células HeLa , Humanos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/metabolismo , Ácidos Hidroxâmicos/farmacologia , Ácidos Hidroxâmicos/uso terapêutico , Indóis/farmacologia , Indóis/uso terapêutico , Maleimidas/farmacologia , Maleimidas/uso terapêutico , Metaloproteases/antagonistas & inibidores , Metaloproteases/metabolismo , Permeabilidade , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Proteólise/efeitos dos fármacos , Piridinas/farmacologia , Piridinas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Tiazóis/farmacologia , Tiazóis/uso terapêutico , Versicanas/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Corpo Vítreo/metabolismo , Quinases Associadas a rho/metabolismo
4.
Arterioscler Thromb Vasc Biol ; 40(9): 2212-2226, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32640908

RESUMO

OBJECTIVE: The ductus arteriosus (DA) is a fetal artery connecting the aorta and pulmonary arteries. Progressive matrix remodeling, that is, intimal thickening (IT), occurs in the subendothelial region of DA to bring anatomic DA closure. IT is comprised of multiple ECMs (extracellular matrices) and migrated smooth muscle cells (SMCs). Because glycoprotein fibulin-1 binds to multiple ECMs and regulates morphogenesis during development, we investigated the role of fibulin-1 in DA closure. Approach and Results: Fibulin-1-deficient (Fbln1-/-) mice exhibited patent DA with hypoplastic IT. An unbiased transcriptome analysis revealed that EP4 (prostaglandin E receptor 4) stimulation markedly increased fibulin-1 in DA-SMCs via phospholipase C-NFκB (nuclear factor κB) signaling pathways. Fluorescence-activated cell sorting (FACS) analysis demonstrated that fibulin-1 binding protein versican was derived from DA-endothelial cells (ECs). We examined the effect of fibulin-1 on directional migration toward ECs in association with versican by using cocultured DA-SMCs and ECs. EP4 stimulation promoted directional DA-SMC migration toward ECs, which was attenuated by either silencing fibulin-1 or versican. Immunofluorescence demonstrated that fibulin-1 and versican V0/V1 were coexpressed at the IT of wild-type DA, whereas 30% of versican-deleted mice lacking a hyaluronan binding site displayed patent DA. Fibulin-1 expression was attenuated in the EP4-deficient mouse (Ptger4-/-) DA, which exhibits patent DA with hypoplastic IT, and fibulin-1 protein administration restored IT formation. In human DA, fibulin-1 and versican were abundantly expressed in SMCs and ECs, respectively. CONCLUSIONS: Fibulin-1 contributes to DA closure by forming an environment favoring directional SMC migration toward the subendothelial region, at least, in part, in combination with EC-derived versican and its binding partner hyaluronan.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Permeabilidade do Canal Arterial/metabolismo , Canal Arterial/metabolismo , Células Endoteliais/metabolismo , Matriz Extracelular/metabolismo , Miócitos de Músculo Liso/metabolismo , Animais , Proteínas de Ligação ao Cálcio/deficiência , Proteínas de Ligação ao Cálcio/genética , Movimento Celular , Células Cultivadas , Técnicas de Cocultura , Canal Arterial/anormalidades , Permeabilidade do Canal Arterial/genética , Permeabilidade do Canal Arterial/patologia , Células Endoteliais/patologia , Matriz Extracelular/genética , Matriz Extracelular/patologia , Humanos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miócitos de Músculo Liso/patologia , NF-kappa B/metabolismo , Técnicas de Cultura de Órgãos , Proteína Quinase C/metabolismo , Ratos Wistar , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Transdução de Sinais , Fosfolipases Tipo C/metabolismo
5.
Proc Natl Acad Sci U S A ; 117(29): 17348-17358, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32636261

RESUMO

The cerebellar posterior vermis generates an estimation of our motion (translation) and orientation (tilt) in space using cues originating from semicircular canals and otolith organs. Theoretical work has laid out the basic computations necessary for this signal transformation, but details on the cellular loci and mechanisms responsible are lacking. Using a multicomponent modeling approach, we show that canal and otolith information are spatially and temporally matched in mouse posterior vermis Purkinje cells and that Purkinje cell responses combine translation and tilt information. Purkinje cell-specific inhibition of protein kinase C decreased and phase-shifted the translation component of Purkinje cell responses, but did not affect the tilt component. Our findings suggest that translation and tilt signals reach Purkinje cells via separate information pathways and that protein kinase C-dependent mechanisms regulate translation information processing in cerebellar cortex output neurons.


Assuntos
Vermis Cerebelar/fisiologia , Membrana dos Otólitos/fisiologia , Proteína Quinase C/metabolismo , Células de Purkinje/metabolismo , Animais , Córtex Cerebelar , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Plasticidade Neuronal
6.
Nat Commun ; 11(1): 3688, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32703948

RESUMO

Zeta inhibitory peptide (ZIP), a PKMζ inhibitor, is widely used to interfere with the maintenance of acquired memories. ZIP is able to erase memory even in the absence of PKMζ, via an unknown mechanism. We found that ZIP induces redistribution of the AMPARGluA1 in HEK293 cells and primary cortical neurons, and decreases AMPAR-mediated currents in the nucleus accumbens (NAc). These effects were mimicked by free arginine or by a modified ZIP in which all but the arginine residues were replaced by alanine. Redistribution was blocked by a peptidase-resistant version of ZIP and by treatment with the nitric oxide (NO)-synthase inhibitor L-NAME. ZIP increased GluA1-S831 phosphorylation and ZIP-induced redistribution was blocked by nitrosyl-mutant GluA1-C875S or serine-mutant GluA1-S831A. Introducing the cleavable arginine-alanine peptide into the NAc attenuated expression of cocaine-conditioned reward. Together, these results suggest that ZIP may act as an arginine donor, facilitating NO-dependent downregulation of AMPARs, thereby attenuating learning and memory.


Assuntos
Peptídeos Penetradores de Células/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Lipopeptídeos/farmacologia , Memória de Longo Prazo/efeitos dos fármacos , Óxido Nítrico/metabolismo , Receptores de AMPA/metabolismo , Animais , Cocaína/administração & dosagem , Regulação para Baixo , Endocitose/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Células HEK293 , Humanos , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Camundongos , Modelos Animais , NG-Nitroarginina Metil Éster/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Óxido Nítrico/antagonistas & inibidores , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/fisiologia , Fosforilação , Cultura Primária de Células , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Ratos , Receptores de AMPA/genética , Recompensa , Técnicas Estereotáxicas
7.
PLoS One ; 15(7): e0235747, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32658903

RESUMO

Despite development of markers for identification of cancer stem cells, the mechanism underlying the survival and division of cancer stem cells in breast cancer remains unclear. Here we report that PKCλ expression was enriched in basal-like breast cancer, among breast cancer subtypes, and was correlated with ALDH1A3 expression (p = 0.016, χ2-test). Late stage breast cancer patients expressing PKCλhigh and ALDH1A3high had poorer disease-specific survival than those expressing PKCλlow and ALDH1A3low (p = 0.018, log rank test for Kaplan-Meier survival curves: hazard ratio 2.58, 95% CI 1.24-5.37, p = 0.011, multivariate Cox regression analysis). Functional inhibition of PKCλ through siRNA-mediated knockdown or CRISPR-Cas9-mediated knockout in ALDH1high MDA-MB 157 and MDA-MB 468 basal-like breast cancer cells led to increases in the numbers of trypan blue-positive and active-caspase 3-positive cells, as well as suppression of tumor-sphere formation and cell migration. Furthermore, the amount of CASP3 and PARP mRNA and the level of cleaved caspase-3 protein were enhanced in PKCλ-deficient ALDH1high cells. An Apoptosis inhibitor (z-VAD-FMK) suppressed the enhancement of cell death as well as the levels of cleaved caspase-3 protein in PKCλ deficient ALDH1high cells. It also altered the asymmetric/symmetric distribution ratio of ALDH1A3 protein. In addition, PKCλ knockdown led to increases in cellular ROS levels in ALDH1high cells. These results suggest that PKCλ is essential for cancer cell survival and migration, tumorigenesis, the asymmetric distribution of ALDH1A3 protein among cancer cells, and the maintenance of low ROS levels in ALDH1-positive breast cancer stem cells. This makes it a key contributor to the poorer prognosis seen in late-stage breast cancer patients.


Assuntos
Aldeído Oxirredutases/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/mortalidade , Regulação Neoplásica da Expressão Gênica , Isoenzimas/metabolismo , Células-Tronco Neoplásicas/patologia , Proteína Quinase C/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Movimento Celular , Proliferação de Células , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/metabolismo , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas
8.
Clin Sci (Lond) ; 134(12): 1449-1456, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32556178

RESUMO

Hepatitis C virus (HCV) infection and chronic hepatitis C (CHC) are associated with a measurable risk of insulin resistance (IR)/impaired glucose tolerance (IGT)/diabetes mellitus (DM). While loss of hepatic endocrine function contributes to liver cirrhosis in diabetic patients, onset and progression of IR/IGT to diabetes and exacerbation of incident hyperglycemia are ostensibly linked with chronic HCV infection. In this regard, the study by Chen J et al. appearing in Clinical Science (2020) (134(5) https://doi.org/10.1042/CS20190900) attempts to understand the mechanisms underlying the savaging effects of chronic HCV infection on insulin-producing pancreatic ß-cells and hence diabetic onset. The study investigated the role of mitogen-activated protein kinase (MAPK) p38δ-protein kinase D (PKD)-golgi complex axis in impacting insulin exocytosis. It was inferred that an insulin secretory defect of pancreatic ß-cells, owing to disrupted insulin exocytosis, to an extent explains ß-cell dysfunction in HCV-infected or CHC milieu. HCV infection negatively regulates first-phase and second-phase insulin secretion by impinging on PKD-dependent insulin secretory granule fission at trans-golgi network and insulin secretory vesicle membrane fusion events. This commentary highlights the study in question, that deciphered the contribution of p38δ MAPK-PKD-golgi complex axis to ß-cell dysfunction in CHC milieu. This pivotal axis proffers a formidable therapeutic opportunity for alleviation of double burden of glucose abnormalities/DM and CHC.


Assuntos
Exocitose , Complexo de Golgi/metabolismo , Hepatite C Crônica/metabolismo , Hepatite C Crônica/patologia , Insulina/metabolismo , Proteína Quinase 13 Ativada por Mitógeno/metabolismo , Proteína Quinase C/metabolismo , Animais , Humanos , Camundongos Endogâmicos C57BL , Modelos Biológicos
9.
Ecotoxicol Environ Saf ; 202: 110876, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32563953

RESUMO

This study investigated the acute in vitro effect of low-concentration bisphenol A (BPA) on calcium (45Ca2+) influx in zebrafish (Danio rerio) testis and examined whether intracellular Ca2+ was involved in the effects of BPA on testicular toxicity. In vitro studies on 45Ca2+ influx were performed in the testes after incubation with BPA for 30 min. Inhibitors were added 15 min before the addition of 45Ca2+ and BPA to testes to study the mechanism of action of BPA. The involvement of intracellular calcium from stores on lactate dehydrogenase (LDH) release and on triacylglycerol (TAG) content were carried out after in vitro incubation of testes with BPA for 1 h. Furthermore, gamma-glutamyl transpeptidase (GGT) and aspartate aminotransferase (AST) activities were analyzed in the liver at 1 h after in vitro BPA incubation of D. rerio. Our data show that the acute in vitro treatment of D. rerio testes with BPA at very low concentration activates plasma membrane ionic channels, such as voltage-dependent calcium channels and calcium-dependent chloride channels, and protein kinase C (PKC), which stimulates Ca2+ influx. In addition, BPA increased cytosolic Ca2+ by activating inositol triphosphate receptor (IP3R) and inhibiting sarco/endoplasmic reticulum calcium ATPase (SERCA) at the endoplasmic reticulum, contributing to intracellular Ca2+ overload. The protein kinases, PKC, MEK 1/2 and PI3K, are involved in the mechanism of action of BPA, which may indicate a crosstalk between the non-genomic initiation effects mediated by PLC/PKC/IP3R signaling and genomic responses of BPA mediated by the estrogen receptor (ESR). In vitro exposure to a higher concentration of BPA caused cell damage and plasma membrane injury with increased LDH release and TAG content; both effects were dependent on intracellular Ca2+ and mediated by IP3R. Furthermore, BPA potentially induced liver damage, as demonstrated by increased GGT activity. In conclusion, in vitro effect of BPA in a low concentration triggers cytosolic Ca2+ overload and activates downstream protein kinases pointing to a crosstalk between its non-genomic and genomic effects of BPA mediated by ESR. Moreover, in vitro exposure to a higher concentration of BPA caused intracellular Ca2+-dependent testicular cell damage and plasma membrane injury. This acute toxicity was reinforced by increased testicular LDH release and GGT activity in the liver.


Assuntos
Compostos Benzidrílicos/toxicidade , Cálcio/metabolismo , Fenóis/toxicidade , Testículo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Membrana Celular/metabolismo , Citosol/metabolismo , Retículo Endoplasmático/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/antagonistas & inibidores , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Canais Iônicos , Masculino , Proteína Quinase C/metabolismo , Proteína Quinase C/farmacologia , Transdução de Sinais/efeitos dos fármacos , Testículo/metabolismo , Peixe-Zebra/metabolismo
10.
Proc Natl Acad Sci U S A ; 117(25): 14280-14291, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513715

RESUMO

In utero mammalian development relies on the establishment of the maternal-fetal exchange interface, which ensures transportation of nutrients and gases between the mother and the fetus. This exchange interface is established via development of multinucleated syncytiotrophoblast cells (SynTs) during placentation. In mice, SynTs develop via differentiation of the trophoblast stem cell-like progenitor cells (TSPCs) of the placenta primordium, and in humans, SynTs are developed via differentiation of villous cytotrophoblast (CTB) progenitors. Despite the critical need in pregnancy progression, conserved signaling mechanisms that ensure SynT development are poorly understood. Herein, we show that atypical protein kinase C iota (PKCλ/ι) plays an essential role in establishing the SynT differentiation program in trophoblast progenitors. Loss of PKCλ/ι in the mouse TSPCs abrogates SynT development, leading to embryonic death at approximately embryonic day 9.0 (E9.0). We also show that PKCλ/ι-mediated priming of trophoblast progenitors for SynT differentiation is a conserved event during human placentation. PKCλ/ι is selectively expressed in the first-trimester CTBs of a developing human placenta. Furthermore, loss of PKCλ/ι in CTB-derived human trophoblast stem cells (human TSCs) impairs their SynT differentiation potential both in vitro and after transplantation in immunocompromised mice. Our mechanistic analyses indicate that PKCλ/ι signaling maintains expression of GCM1, GATA2, and PPARγ, which are key transcription factors to instigate SynT differentiation programs in both mouse and human trophoblast progenitors. Our study uncovers a conserved molecular mechanism, in which PKCλ/ι signaling regulates establishment of the maternal-fetal exchange surface by promoting trophoblast progenitor-to-SynT transition during placentation.


Assuntos
Diferenciação Celular/fisiologia , Isoenzimas/metabolismo , Troca Materno-Fetal/fisiologia , Placenta/metabolismo , Proteína Quinase C/metabolismo , Trofoblastos/fisiologia , Animais , Proteínas de Ligação a DNA/metabolismo , Feminino , Fator de Transcrição GATA2/metabolismo , Humanos , Isoenzimas/genética , Masculino , Camundongos , Camundongos Knockout , Modelos Animais , PPAR gama/metabolismo , Placenta/citologia , Placentação/fisiologia , Gravidez , Proteína Quinase C/genética , Transdução de Sinais , Células-Tronco/citologia , Fatores de Transcrição/metabolismo , Trofoblastos/citologia
11.
Life Sci ; 256: 117886, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32497631

RESUMO

AIMS: Reactive oxygen species (ROS) caused by high glucose (HG) is involved in a lot of diseases including diabetes. However, the underlying mechanism of ROS induction by HG remains unclear. Emerging evidence has shown the 8-oxoguanine glycosylase (OGG1) is the main DNA glycosylase responsible for atherosclerosis, obesity, hepatic steatosis, and insulin resistance, and so on. Our aim was to explore the role of OGG1 on HG-mediated endothelial ROS. MAIN METHODS: Human umbilical vein endothelial cells (HUVECs) were exposed to HG (30 mM) for different time periods. HG predominantly inhibited OGG1 expression in a time-dependent manner measured by western blotting, qPCR and immunofluorescence. Additionally, HUVECs were cultured with a fluorescent probe, DCFH and DHE, after being subjected to HG. Cell chemiluminescence and flow cytometry results revealed that HG caused endothelial ROS activation. KEY FINDINGS: High glucose remarkably decreased endothelial OGG1 expression. The overexpression of OGG1 significantly reversed HG-mediated PKC and NADPH oxidase activities and ROS levels. Moreover, manipulated expression of PKC significantly contacted the role of OGG1 on NADPH oxidase activation. SIGNIFICANCE: These results suggest that OGG1 downregulation promoted HG-induced endothelial ROS production and might be a potential clinical treatment target of diabetics.


Assuntos
DNA Glicosilases/metabolismo , Glucose/toxicidade , Células Endoteliais da Veia Umbilical Humana/metabolismo , NADPH Oxidases/metabolismo , Proteína Quinase C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Animais , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Camundongos , Modelos Biológicos , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
12.
PLoS Genet ; 16(6): e1008890, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32579558

RESUMO

The Drosophila apical photoreceptor membrane is defined by the presence of two distinct morphological regions, the microvilli-based rhabdomere and the stalk membrane. The subdivision of the apical membrane contributes to the geometrical positioning and the stereotypical morphology of the rhabdomeres in compound eyes with open rhabdoms and neural superposition. Here we describe the characterization of the photoreceptor specific protein PIP82. We found that PIP82's subcellular localization demarcates the rhabdomeric portion of the apical membrane. We further demonstrate that PIP82 is a phosphorylation target of aPKC. PIP82 localization is modulated by phosphorylation, and in vivo, the loss of the aPKC/Crumbs complex results in an expansion of the PIP82 localization domain. The absence of PIP82 in photoreceptors leads to misshapped rhabdomeres as a result of misdirected cellular trafficking of rhabdomere proteins. Comparative analyses reveal that PIP82 originated de novo in the lineage leading to brachyceran Diptera, which is also characterized by the transition from fused to open rhabdoms. Taken together, these findings define a novel factor that delineates and maintains a specific apical membrane domain, and offers new insights into the functional organization and evolutionary history of the Drosophila retina.


Assuntos
Membrana Celular/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Células Fotorreceptoras de Invertebrados/metabolismo , Retina/crescimento & desenvolvimento , Animais , Animais Geneticamente Modificados , Evolução Biológica , Diferenciação Celular/genética , Membrana Celular/genética , Membrana Celular/ultraestrutura , Polaridade Celular/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Mutação com Perda de Função , Masculino , Microscopia Eletrônica de Transmissão , Fosforilação , Células Fotorreceptoras de Invertebrados/citologia , Células Fotorreceptoras de Invertebrados/ultraestrutura , Filogenia , Proteína Quinase C/metabolismo , Retina/citologia , Retina/ultraestrutura , Transcrição Genética
13.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(1): 17-22, 2020 Jan 28.
Artigo em Chinês | MEDLINE | ID: mdl-32476368

RESUMO

OBJECTIVE: To observe the effects of acute exhaustive exercise on the expressions of oxidative stress related enzymes in skeletal muscle of rats. METHODS: Forty male SD rats were divided into 4 groups, 10 rats in each group, which were the control group (C group), exhausted exercise group (E group), exercise + PKC inhibitor group (EC group), exercise + NOX inhibitor group (EA group). Three groups of exercise rats were familiarized with treadmill running for 3 days (5 m/min, once/d, no incline), then rested for one day. EC group was injected with PKC inhibitor chelerythrine (5 mg / kg) one day before and one hour before exercise, EA group was injected with NADPH oxidase inhibitor apocynin (10 mg / kg) at the same time, group C and group E were injected with the same dose of normal saline. Three groups of exercise rats were subjected to a one-time treadmill exhaustion exercise, and the plantaris were taken after exhaustion. Reactive oxygen species (ROS) were detected by DCF fluorescent probe, NOX2, NOX4, 3-NT were analyzed by Western blot, and PKC, NOX2, NOX4 were analyzed by immunoprecipitation. RESULTS: Compared with group C, ROS level, NOX2 and NOX4 protein expressions, PKC-NOX2 and PKC-NOX4 complex levels, and 3-NT production in group E were significantly increased (P<0.01, P<0.05), and ROS level was no significant difference in group EC and group EA (P>0.05), and NOX4 protein expression in group EC was significantly increased (P < 0.05). Compared with group E, ROS level, NOX2 and NOX4 protein expressions, PKC-NOX2 and PKC-NOX4 complex levels, 3-NT production were decreased significantly (P<0.01, P<0.05). CONCLUSION: Exhausted exercise induces increased expressions of NOX2 and NOX4 proteins in skeletal muscle, and PKC mediates the production of ROS by regulating NOX2.


Assuntos
Músculo Esquelético/fisiologia , NADPH Oxidase 2/metabolismo , NADPH Oxidase 4/metabolismo , Estresse Oxidativo , Condicionamento Físico Animal , Acetofenonas/farmacologia , Animais , Masculino , NADPH Oxidases , Proteína Quinase C/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
14.
Clin Sci (Lond) ; 134(10): 1167-1180, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32458968

RESUMO

In the present study, we evaluated the metabolic effects of green tea polyphenols (GTPs) in high-fat diet (HFD) fed Zucker fatty (ZF) rats, in particular the effects of GTP on skeletal muscle insulin sensitivity. Body weight, visceral fat, glucose tolerance, lipid profiles and whole-body insulin sensitivity were measured in HFD-fed ZF rats after 8-week-treatment with GTP (200 mg/kg of body weight) or saline (5 ml/kg of body weight). Zucker lean rats were studied as controls. Ex vivo insulin-mediated muscle glucose uptake was assessed. Immunoblotting was used to evaluate the expression of key insulin signalling proteins in skeletal muscle. GTP treatment attenuated weight gain (P<0.05) and visceral fat accumulation (27.6%, P<0.05), and significantly reduced fasting serum glucose (P<0.05) and insulin (P<0.01) levels. Homoeostasis model assessment of insulin resistance (HOMA-IR), a measure of insulin resistance, was lower (P<0.01) in GTP-treated animals compared with ZF controls. Moreover, insulin-stimulated glucose uptake by isolated soleus muscle was increased (P<0.05) in GTP-ZF rats compared with ZF-controls. GTP treatment attenuated the accumulation of ectopic lipids (triacyl- and diacyl-glycerols), enhanced the expression and translocation of glucose transporter-4, and decreased pSer612IRS-1 and increased pSer473Akt2 expression in skeletal muscle. These molecular changes were also associated with significantly decreased activation of the inhibitory (muscle-specific) protein kinase (PKC) isoform, PKC-θ. Taken together, the present study has shown that regular ingestion of GTP exerts a number of favourable metabolic and molecular effects in an established animal model of obesity and insulin resistance. The benefits of GTP are mediated in part by inhibiting PKC-θ and improving muscle insulin sensitivity.


Assuntos
Resistência à Insulina , Insulina/metabolismo , Músculo Esquelético/metabolismo , Polifenóis/farmacologia , Transdução de Sinais , Chá/química , Adiposidade/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Glucose/metabolismo , Teste de Tolerância a Glucose , Transportador de Glucose Tipo 4/metabolismo , Gordura Intra-Abdominal/efeitos dos fármacos , Gordura Intra-Abdominal/metabolismo , Isoenzimas/metabolismo , Masculino , Proteínas Musculares/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/enzimologia , Fosforilação/efeitos dos fármacos , Proteína Quinase C/metabolismo , Transporte Proteico/efeitos dos fármacos , Ratos Zucker
15.
Chem Biol Interact ; 326: 109128, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32416088

RESUMO

Exposure to mycotoxins is mostly by ingestion but also occurs by the dermal and inhalation routes. The present study for the first time demonstrated that mycotoxin Deoxynivalenol (DON), permeates through Swiss albino mice skin, which demands awareness of health risks in people who are dermally exposed to mycotoxins especially agricultural farmers. Despite the widespread contamination of DON in food commodities studies to alleviate DON's toxicity are sparsely reported. Thus effective measures to combat mycotoxins associated toxicity remains an imperative aspect to be considered from the angle of dermal exposure. Topical application of Celecoxib (1-2 mg), followed by DON (100 µg) application on the dorsal side of mice, resulted in substantial decrease in DON-induced (i) edema, hyperplasia, cell proliferation (ii) inhibition of cytokine and prostaglandin-E2 levels (iii) phosphorylation of ERK1/2, JNK, p38, MAPKKs, CREB, P90-RSK (iv) downregulation of c-Jun, c- Fos, phospho-NF-kB and their downstream target proteins cyclin D1 and COX-2. Using Ro-31-8220 (Protein-Kinase-C inhibitor), it was observed PKC was responsible for DON induced upregulation of COX-2 and iNOS proteins. Treatment of Celecoxib decreased DON-induced translocation of Protein Kinase C isozymes (α,ε,γ), demonstrating the role of PKC in DON-mediated biochemical and molecular alterations responsible for its dermal toxicity. The present findings indicate that topical application of celecoxib is effective in the management of inflammatory skin disorders induced by foodborne fungal toxin DON. The skin permeation potential of Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor NSAID, was also assessed, and the results indicated that the permeation was relatively lower as compared to the oral mode of administration. Hence topical use of celecoxib may be preferred over oral dosing because of lower systemic absorption and to avoid the unwanted side effects. This study provides a prospect for exploring the clinical efficacy of topically applied COX-2 inhibitors for the management of inflammatory skin disorders induced by foodborne fungal toxins.


Assuntos
Celecoxib/farmacologia , Proliferação de Células/efeitos dos fármacos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Proteína Quinase C/metabolismo , Pele/efeitos dos fármacos , Tricotecenos/efeitos adversos , Animais , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Feminino , Inflamação/metabolismo , Camundongos , Transdução de Sinais/efeitos dos fármacos , Pele/metabolismo , Dermatopatias/tratamento farmacológico , Dermatopatias/metabolismo
16.
Life Sci ; 253: 117728, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32353430

RESUMO

AIMS: Studies indicate that the pattern of shear stress determines the direction of endothelial progenitor cells (EPCs) differentiation. However, the mechanism remains largely unknown. Herein, we try to identify the role of oscillatory shear stress (OSS) in the transdifferentiation of EPCs into mesenchymal cells and the mechanism involved. MATERIALS AND METHODS: OSS was applied to EPCs using the flow chamber system in vitro. Matrigel, Boyden chamber, and healing assay were used to observe the changes in EPCs function. Further, 2',7'-dichlorofluorescein diacetate (DCFH-DA) probe and/or western blot were performed to detect the expression of reactive oxygen species (ROS), p53 and PKCζ in EPCs. EPCs transduced with Lentivirus carrying Tp53 were implanted into the arterial vessel in the balloon injured rat model, and neointimal thickening was verified by HE staining. KEY FINDINGS: OSS enhanced the expression of mesenchymal cell markers alpha-smooth muscle actin (α-SMA) and smooth muscle 22 alpha (SM22α) on EPCs. In the meantime, OSS time-dependently decreased p53 expression in EPCs, which was partially abolished by treatment with ROS scavenger N-acetylcysteine (NAC) or protein kinase C zeta (PKCζ) inhibitor Go6983. Moreover, the p53 agonist tenovin-1 attenuated the changes of OSS-mediated the mesenchymal cell markers and EPCs function. Besides, we also found that transplanting EPCs transfected with LV-Tp53 significantly inhibited neointimal thickening and promoted reendothelialization in vivo. SIGNIFICANCE: This study demonstrates OSS-induced EPC transdifferentiation into mesenchymal cells and ROS/PKCζ/p53 pathway play an essential role in it. It may serve as a promising therapeutic target for cardiovascular disease in the future.


Assuntos
Células Progenitoras Endoteliais/citologia , Células-Tronco Mesenquimais/citologia , Espécies Reativas de Oxigênio/metabolismo , Estresse Mecânico , Acetanilidas/farmacologia , Animais , Diferenciação Celular/fisiologia , Transdiferenciação Celular/fisiologia , Células Cultivadas , Masculino , Proteína Quinase C/metabolismo , Ratos , Tioureia/análogos & derivados , Tioureia/farmacologia , Fatores de Tempo , Proteína Supressora de Tumor p53/metabolismo
17.
Proc Natl Acad Sci U S A ; 117(20): 10688-10698, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32371485

RESUMO

AIDS is a pandemic disease caused by HIV that affects 37 million people worldwide. Current antiretroviral therapy slows disease progression but does not eliminate latently infected cells, which resupply active virus, thus necessitating lifelong treatment with associated compliance, cost, and chemoexposure issues. Latency-reversing agents (LRAs) activate these cells, allowing for their potential clearance, thus presenting a strategy to eradicate the infection. Protein kinase C (PKC) modulators-including prostratin, ingenol esters, bryostatin, and their analogs-are potent LRAs in various stages of development for several clinical indications. While LRAs are promising, a major challenge associated with their clinical use is sustaining therapeutically meaningful levels of the active agent while minimizing side effects. Here we describe a strategy to address this problem based on LRA prodrugs, designed for controllable release of the active LRA after a single injection. As intended, these prodrugs exhibit comparable or superior in vitro activity relative to the parent compounds. Selected compounds induced higher in vivo expression of CD69, an activation biomarker, and, by releasing free agent over time, significantly improved tolerability when compared to the parent LRAs. More generally, selected prodrugs of PKC modulators avoid the bolus toxicities of the parent drug and exhibit greater efficacy and expanded tolerability, thereby addressing a longstanding objective for many clinical applications.


Assuntos
Fármacos Anti-HIV/farmacologia , Briostatinas/farmacologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Pró-Fármacos/farmacologia , Proteína Quinase C/metabolismo , Latência Viral/efeitos dos fármacos , Animais , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/uso terapêutico , Briostatinas/síntese química , Briostatinas/uso terapêutico , Linhagem Celular Tumoral , Células Cultivadas , Diterpenos/química , Infecções por HIV/tratamento farmacológico , HIV-1/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Ésteres de Forbol/química , Pró-Fármacos/síntese química , Pró-Fármacos/uso terapêutico , Proteína Quinase C/efeitos dos fármacos
18.
Nat Commun ; 11(1): 2266, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385244

RESUMO

The evolutionarily conserved Par3/Par6/aPKC complex regulates the polarity establishment of diverse cell types and distinct polarity-driven functions. However, how the Par complex is concentrated beneath the membrane to initiate cell polarization remains unclear. Here we show that the Par complex exhibits cell cycle-dependent condensation in Drosophila neuroblasts, driven by liquid-liquid phase separation. The open conformation of Par3 undergoes autonomous phase separation likely due to its NTD-mediated oligomerization. Par6, via C-terminal tail binding to Par3 PDZ3, can be enriched to Par3 condensates and in return dramatically promote Par3 phase separation. aPKC can also be concentrated to the Par3N/Par6 condensates as a client. Interestingly, activated aPKC can disperse the Par3/Par6 condensates via phosphorylation of Par3. Perturbations of Par3/Par6 phase separation impair the establishment of apical-basal polarity during neuroblast asymmetric divisions and lead to defective lineage development. We propose that phase separation may be a common mechanism for localized cortical condensation of cell polarity complexes.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Complexos Multiproteicos/metabolismo , Animais , Células COS , Ciclo Celular , Diferenciação Celular , Sobrevivência Celular , Chlorocebus aethiops , Proteínas de Drosophila/química , Drosophila melanogaster/citologia , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Larva/citologia , Complexos Multiproteicos/química , Neurônios/citologia , Neurônios/metabolismo , Domínios Proteicos , Proteína Quinase C/metabolismo , Ratos
19.
Arch Biochem Biophys ; 687: 108375, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32339486

RESUMO

Homo sapiens orphan G protein-coupling receptor PEIG-1 was first cloned and characterized by applying differential display to T84 colonic carcinoma cells incubated in the presence of phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) (GenBank AF506289.1). Later, Lotan's laboratory found the same gene product in response to retinoic acid analogues, naming it with the symbol RAIG1. Now the official HGNC symbol is GPRC5A. Here, we report the extension of its original cDNA fragment towards the 5' and 3' end. In addition, we show that TPA (100 ng/ml, 162 nM) strongly stimulated GPRC5A mRNA in T84 colonic carcinoma cells, with maximal expression at 4 h and 100 ng/ml (162 nM). Western blots showed several bands between 35 and 50 kDa, responding to TPA stimulation. Confocal microscopy confirmed its TPA upregulation and the location in the plasma membrane. The PKC inhibitor Gö 6983 (10 µM), and the Ca2+ chelator BAPTA-AM (150 µM), strongly inhibited its TPA induced upregulation. The PKA inhibitor H-89 (10 µM), and the MEK1/2 inhibitor U0126 (10 µM), also produced a significant reduction in the TPA response (~50%). The SGK1 inhibitor GSK650394 stimulated GPRC5A basal levels at low doses and inhibit its TPA-induced expression at concentrations ≥10 µM. The IL-1ß autocrine loop and downstream signalling did not affect its expression. In conclusion, RAIG1/RAI3/GPRC5A corresponds to the originally reported PEIG-1/TIG1; the inhibition observed in the presence of Gö 6983, BAPTA and U0126, suggests that its TPA-induced upregulation is mediated through a PKC/Ca2+ →MEK1/2 signalling axis. PKA and SGK1 kinases are also involved in its TPA-induced upregulation.


Assuntos
Proteína Quinase C/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Sequência de Aminoácidos , Butadienos/farmacologia , Linhagem Celular Tumoral , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Humanos , Indóis/farmacologia , Isoquinolinas/farmacologia , Maleimidas/farmacologia , Nitrilos/farmacologia , Conformação Proteica em alfa-Hélice , Estrutura Terciária de Proteína , RNA Mensageiro/metabolismo , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/genética , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Regulação para Cima/efeitos dos fármacos
20.
Int J Mol Sci ; 21(7)2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32276377

RESUMO

Phosphoinositides (PI) form just a minor portion of the total phospholipid content in cells but are significantly involved in cancer development and progression. In several cancer types, phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] play significant roles in regulating survival, proliferation, invasion, and growth of cancer cells. Phosphoinositide-specific phospholipase C (PLC) catalyze the generation of the essential second messengers diacylglycerol (DAG) and inositol 1,4,5 trisphosphate (InsP3) by hydrolyzing PtdIns(4,5)P2. DAG and InsP3 regulate Protein Kinase C (PKC) activation and the release of calcium ions (Ca2+) into the cytosol, respectively. This event leads to the control of several important biological processes implicated in cancer. PLCs have been extensively studied in cancer but their regulatory roles in the oncogenic process are not fully understood. This review aims to provide up-to-date knowledge on the involvement of PLCs in cancer. We focus specifically on PLCß, PLCγ, PLCδ, and PLCε isoforms due to the numerous evidence of their involvement in various cancer types.


Assuntos
Neoplasias/enzimologia , Fosfatidilinositóis/metabolismo , Fosfoinositídeo Fosfolipase C/metabolismo , Transdução de Sinais , Animais , Diglicerídeos/metabolismo , Humanos , Neoplasias/metabolismo , Neoplasias/fisiopatologia , Proteína Quinase C/metabolismo
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