RESUMO
Acute kidney injury (AKI) is a heterogeneous clinical syndrome with diverse outcomes. The recovery from AKI has prognostic importance. Little research has been done in order to find biomarkers that can predict recovery from AKI. Cav-2 is one of the main constituents of caveolae and is expressed in kidney. This study analyzed the time course of Cav-2 urinary excretion and renal expression in rats treated with cisplatin. Male Wistar rats were injected with cisplatin (5â¯mg/kg b.w., i.p.), and the studies were performed after 2, 4 and 14 days. Cav-2 abundance was evaluated in urine, in renal homogenates and in apical membranes by Western blotting. Cav-2 in urine was increased only 14 days after treatment, in the recovery phase of cisplatin-induced AKI. These results show that Cav-2 in urine could be useful as a biomarker of renal recovery, but not as an early biomarker of cisplatin-induced AKI. Cav-2 expression in total renal homogenates was not modified with treatment, but a down-regulation of Cav-2 in apical membranes was observed in treated animals. We hypothesize that Cav-2 internalizes into renal cells from their apical membrane in response to cisplatin, and regulates in this manner different signaling proteins involved in the physiopathology of renal damage.
Assuntos
Injúria Renal Aguda/urina , Caveolina 2/urina , Cisplatino , Rim/metabolismo , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/fisiopatologia , Animais , Biomarcadores/urina , Modelos Animais de Doenças , Rim/fisiopatologia , Masculino , Ratos Wistar , Recuperação de Função Fisiológica , Eliminação Renal , Fatores de TempoRESUMO
Caveolin-2 (Cav-2) is expressed in a variety of cell tissue, and it has also been found in renal tissue. The expression of Cav-2 in proximal tubules is still unclear. The aim of this study was to carry out a complete evaluation of the expression pattern of Cav-2 in rat renal cortex to clarify and deepen the knowledge about the localization of Cav-2 in the proximal tubules and also to evaluate its presence in urine. Male Wistar rats were used to assess Cav-2 expression by Western blot analysis in homogenates, apical, and basolateral membranes from kidney cortex, in lysates and total plasma membranes from renal cortical cell suspensions, in urine, and in urinary exosomes. Cav-2 was clearly expressed in renal cortex homogenates and in both apical and basolateral membranes isolated from kidney cortex, with a greater expression on the former membranes. It was also observed in lysates and in plasma membranes from cortical cell suspensions. Moreover, Cav-2 was found in urine and in its exosomal fraction. These results confirmed the presence of Cav-2 in proximal tubule cells in the kidney of healthy rats, and showed for the first time its expression at the apical membrane of these cells and in urine. Besides, urinary exosomal pathway could be involved in Cav-2 urinary excretion under normal conditions. We observed an increase in the urinary abundance of Cav-2 in two models of acute kidney injury, and thus we proposed the urinary excretion of Cav-2 as a potential biomarker of kidney injury.
Assuntos
Injúria Renal Aguda/urina , Caveolina 2/urina , Membrana Celular/genética , Exossomos/metabolismo , Túbulos Renais Proximais/metabolismo , Injúria Renal Aguda/patologia , Animais , Biomarcadores/urina , Membrana Celular/patologia , Exossomos/patologia , Túbulos Renais Proximais/patologia , Masculino , Ratos , Ratos WistarRESUMO
Large-scale genome-wide association studies have identified several susceptibility variants associated with the risk of primary open-angle glaucoma (POAG), among which rs4236601 (CAV1/CAV2) at chromosome 7q31 and rs2157719 at chromosome 9p21 (CDKN2B-AS1). The purpose of this study was to investigate whether these variants contribute to the incidence of POAG in a sample of the Brazilian Southeastern population and to determine the best-fitted genetic model for these single nucleotide polymorphisms (SNPs). A case-control study with 557 individuals, 310 with POAG, and 247 controls was conducted through PCR and direct sequencing. We observed a significant effect of the heterozygous genotype (G/A) of rs2157719 that occurred more frequently in the control group (p = 0.0004; OR: 0.517, CI 95%: 0.357-0.745). Allele frequencies also differed between cases and controls (p = 0.006; OR: 0.694, CI 95%: 0.522-0.922) with the best-fitted genetic model for rs2157719 being the codominant model. No differences were observed for genotype and allele distributions in relation to rs4236601 in the CAV1/CAV2 region. The association of rs2157719 (CDKN2B-AS1) with the POAG phenotype corroborates previously published results, reinforcing the importance of this variant in POAG etiology.
Assuntos
Caveolina 1/genética , Caveolina 2/genética , Glaucoma de Ângulo Aberto/genética , Polimorfismo de Nucleotídeo Único , RNA Longo não Codificante/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Glaucoma de Ângulo Aberto/diagnóstico , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-IdadeRESUMO
Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide. Unfortunately, the incidence and mortality associated with HCC are increasing. Therefore, new therapeutic strategies are urgently needed and the use of mesenchymal stromal cells (MSCs) as carrier of therapeutic genes is emerging as a promising option. Different sources of MSCs are being studied for cell therapy and bone marrow-derived cells are the most extensively explored; however, birth associated-tissues represent a very promising source. The aim of this work was to compare the in vitro and in vivo migration capacity between bone marrow MSCs (BM-MSCs) and human umbilical cord perivascular cells (HUCPVCs) towards HCC. We observed that HUCPVCs presented higher in vitro and in vivo migration towards factors released by HCC. The expression of autocrine motility factor (AMF) receptor, genes related with the availability of the receptor on the cell surface (caveolin-1 and -2) and metalloproteinase 3, induced by the receptor activation and important for cell migration, was increased in HUCPVCs. The chemotactic response towards recombinant AMF was increased in HUCPVCs compared to BM-MSCs, and its inhibition in the conditioned medium from HCC induced higher decrease in HUCPVC migration than in BM-MSC. Our results indicate that HUCPVCs could be a useful cellular source to deliver therapeutic genes to HCC.
Assuntos
Medula Óssea/patologia , Carcinoma Hepatocelular/patologia , Movimento Celular/fisiologia , Neoplasias Hepáticas/patologia , Células-Tronco Mesenquimais/patologia , Receptores do Fator Autócrino de Motilidade/metabolismo , Cordão Umbilical/patologia , Animais , Medula Óssea/metabolismo , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Carcinoma Hepatocelular/metabolismo , Caveolina 1/metabolismo , Caveolina 2/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Meios de Cultivo Condicionados/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Masculino , Metaloproteinase 3 da Matriz/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Nus , Cordão Umbilical/metabolismoRESUMO
Besides a reduction of L-type Ca2+-currents (Ca(V)1), muscarine and the peptidic M1-selective agonist, MT-1, reduced currents through Ca(V)2.1 (P/Q) and Ca(V)2.2 (N) Ca2+ channel types. This modulation was strongly blocked by the peptide MT-7, a specific muscarinic M1-type receptor antagonist but not significantly reduced by the peptide MT-3, a specific muscarinic M4-type receptor antagonist. Accordingly, MT-7, but not MT-3, blocked a muscarinic reduction of the afterhyperpolarizing potential (AHP) and decreased the GABAergic inhibitory postsynaptic currents (IPSCs) produced by axon collaterals that interconnect spiny neurons. Both these functions are known to be dependent on P/Q and N types Ca2+ channels. The action on the AHP had an important effect in increasing firing frequency. The action on the IPSCs was shown to be caused presynaptically as it coursed with an increase in the paired-pulse ratio. These results show: first, that muscarinic M1-type receptor activation is the main cholinergic mechanism that modulates Ca2+ entry through voltage-dependent Ca2+ channels in spiny neurons. Second, this muscarinic modulation produces a postsynaptic facilitation of discharge together with a presynaptic inhibition of the GABAergic control mediated by axon collaterals. Together, both effects would tend to recruit more spiny neurons for the same task.
Assuntos
Acetilcolina/metabolismo , Caveolinas/fisiologia , Neostriado/citologia , Neurônios/fisiologia , Transmissão Sináptica/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Caveolina 2 , Caveolinas/classificação , Caveolinas/efeitos dos fármacos , Células Cultivadas , Interações Medicamentosas , Estimulação Elétrica/métodos , Técnicas In Vitro , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Muscarina/farmacologia , Agonistas Muscarínicos/classificação , Agonistas Muscarínicos/farmacologia , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp/métodos , Ratos , Ratos Wistar , Receptores Muscarínicos/classificação , Receptores Muscarínicos/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacosRESUMO
Caveolins are cholesterol-binding proteins involved in the regulation of several intracellular processes, including cholesterol transport. Because hepatocytes express caveolin-1 and caveolin-2, these proteins might modulate hepatic lipid metabolism and biliary lipid secretion. Our aim was to investigate the potential physiologic role of caveolins in hepatic cholesterol and bile salt (BS) metabolism and transport using adenoviral gene transfer. C57BL/6 mice were infected with recombinant human caveolin-1 and caveolin-2 adenoviruses. Mice infected with adenovirus lacking the transgene were used as controls. Hepatic caveolin expression was evaluated by immunochemical methods. Reverse-transcription polymerase chain reaction (RT-PCR) and immunoblotting were used to assess messenger RNA (mRNA) levels and protein mass of BS transporters (sodium taurocholate cotransporting polypeptide [Ntcp] and bile salt export pump [Bsep]). Serum, liver, biliary, and fecal biochemical determinations and BS maximal secretory rate (SRm) were performed by standard methods. Ad.Cav-1- and Ad.Cav-2-infected mice exhibited a 10- and 7-fold increase in hepatic caveolin-1 and caveolin-2 protein expression, respectively. Caveolin-1-overexpressing mice had a significant increase in plasma high-density lipoprotein (HDL) cholesterol and hepatic free cholesterol content, whereas total plasma cholesterol and triglyceride levels remained unchanged. Hepatic caveolin-1 and/or caveolin-2 overexpression significantly increased bile flow and secretion of all biliary lipids. Caveolin-1-overexpressing mice showed a 2.5-fold increase in taurocholate (TC) SRm, indicating increased canalicular BS transport capacity. BS pool size and fecal BS excretion remained within the normal range in mice with Cav-1 overexpression. No changes were seen in the protein mass of BS transporters Ntcp and Bsep. In conclusion, our findings indicate that caveolins may play an important role in regulating hepatic BS and cholesterol metabolism.