RESUMO
BCL-X mRNA alternative splicing generates pro-apoptotic BCL-XS or anti-apoptotic BCL-XL gene products and the mechanism that regulates splice shifting is incompletely understood. We identified and characterized a long non-coding RNA (lncRNA) named INXS, transcribed from the opposite genomic strand of BCL-X, that was 5- to 9-fold less abundant in tumor cell lines from kidney, liver, breast and prostate and in kidney tumor tissues compared with non-tumors. INXS is an unspliced 1903 nt-long RNA, is transcribed by RNA polymerase II, 5'-capped, nuclear enriched and binds Sam68 splicing-modulator. Three apoptosis-inducing agents increased INXS lncRNA endogenous expression in the 786-O kidney tumor cell line, increased BCL-XS/BCL-XL mRNA ratio and activated caspases 3, 7 and 9. These effects were abrogated in the presence of INXS knockdown. Similarly, ectopic INXS overexpression caused a shift in splicing toward BCL-XS and activation of caspases, thus leading to apoptosis. BCL-XS protein accumulation was detected upon INXS overexpression. In a mouse xenograft model, intra-tumor injections of an INXS-expressing plasmid caused a marked reduction in tumor weight, and an increase in BCL-XS isoform, as determined in the excised tumors. We revealed an endogenous lncRNA that induces apoptosis, suggesting that INXS is a possible target to be explored in cancer therapies.
Assuntos
Apoptose , RNA Longo não Codificante/fisiologia , Proteína bcl-X/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Caspases/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/metabolismo , Humanos , Neoplasias Renais/genética , Neoplasias Renais/patologia , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Isoformas de Proteínas/análise , Isoformas de Proteínas/genética , Splicing de RNA , RNA Longo não Codificante/análise , RNA Longo não Codificante/biossíntese , RNA Longo não Codificante/genética , Proteínas de Ligação a RNA/metabolismo , Proteína bcl-X/análise , Proteína bcl-X/genéticaRESUMO
Epithelial polarization modulates gene expression. The transcription factor zonula occludens 1 (ZO-1)-associated nucleic acid binding protein (ZONAB) can shuttle between tight junctions and nuclei, promoting cell proliferation and expression of cyclin D1 and proliferating cell nuclear antigen (PCNA), but whether it also represses epithelial differentiation is unknown. Here, during mouse kidney ontogeny and polarization of proximal tubular cells (OK cells), ZONAB and PCNA levels decreased in parallel and inversely correlated with increasing apical differentiation, reflected by expression of megalin/cubilin, maturation of the brush border, and extension of the primary cilium. Conversely, ZONAB reexpression and loss of apical differentiation markers provided a signature for renal clear cell carcinoma. In confluent OK cells, ZONAB overexpression increased proliferation and PCNA while repressing megalin/cubilin expression and impairing differentiation of the brush border and primary cilium. Reporter and chromatin immunoprecipitation assays demonstrated that megalin and cubilin are ZONAB target genes. Sparsely plated OK cells formed small islands composed of distinct populations: Cells on the periphery, which lacked external tight junctions, strongly expressed nuclear ZONAB, proliferated, and failed to differentiate; central cells, surrounded by continuous junctions, lost nuclear ZONAB, stopped proliferating, and engaged in apical differentiation. Taken together, these data suggest that ZONAB is an important component of the mechanisms that sense epithelial density and participates in the complex transcriptional networks that regulate the switch between proliferation and differentiation.
Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Túbulos Renais Proximais , Adenocarcinoma de Células Claras/patologia , Adenocarcinoma de Células Claras/fisiopatologia , Adulto , Animais , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Linhagem Celular Tumoral , Polaridade Celular/fisiologia , Regulação para Baixo/fisiologia , Células Epiteliais/citologia , Células Epiteliais/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Neoplasias Renais/patologia , Neoplasias Renais/fisiopatologia , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/embriologia , Túbulos Renais Proximais/fisiologia , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Camundongos , Camundongos Endogâmicos C57BL , Gambás , Regiões Promotoras Genéticas/fisiologia , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Fatores de Transcrição , TransfecçãoRESUMO
Noninvasive analysis of renal function in conscious mice is necessary to optimize the use of mouse models. In this study, we evaluated whether single photon emission-computed tomography (SPECT) using specific radionuclear tracers can be used to analyze changes in renal proximal tubule functions. The tracers included (99m)TC- dimercaptosuccinic acid ((99m)Tc-DMSA), which is used for cortex imaging; (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3), used for dynamic renography; and (123)I-beta(2)-microglobulin, which monitors receptor-mediated endocytosis. (99m)Tc-DMSA SPECT imaging was shown to delineate the functional renal cortex with a approximately 1-mm spatial resolution and accumulated in the cortex reaching a plateau 5 h after injection. The cortical uptake of (99m)Tc-DMSA was abolished in Clcn5 knockout mice, a model of proximal tubule dysfunction. Dynamic renography with (99m)Tc-MAG3 in conscious mice demonstrated rapid extraction from blood, renal accumulation, and subsequent tubular secretion. Anesthesia induced a significant delay in the (99m)Tc-MAG3 clearance. The tubular reabsorption of (123)I-beta(2)-microglobulin was strongly impaired in the Clcn5 knockout mice, with defective tubular processing and loss of the native tracer in urine, reflecting proximal tubule dysfunction. Longitudinal studies in a model of cisplatin-induced acute tubular injury revealed a correlation between tubular recovery and (123)I-beta(2)-microglobulin uptake. These data show that SPECT imaging with well-validated radiotracers allows in vivo investigations of specific proximal tubule functions in conscious mice.
Assuntos
Estado de Consciência , Túbulos Renais Proximais/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Animais , Canais de Cloreto/deficiência , Canais de Cloreto/metabolismo , Cisplatino , Rim/diagnóstico por imagem , Rim/metabolismo , Córtex Renal/diagnóstico por imagem , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Túbulos Renais , Cinética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Renografia por Radioisótopo , Compostos Radiofarmacêuticos/farmacocinética , Ácido Dimercaptossuccínico Tecnécio Tc 99m/farmacocinética , Tecnécio Tc 99m Mertiatida , Microglobulina beta-2/metabolismoRESUMO
High-throughput analyses have shown that aquaporins (AQPs) belong to a cluster of genes that are differentially expressed during kidney organogenesis. However, the spatiotemporal expression patterns of the AQP gene family during tubular maturation and the potential influence of genetic variation on these patterns and on water handling remain unknown. We investigated the expression patterns of all AQP isoforms in fetal (E13.5 to E18.5), postnatal (P1 to P28), and adult (9 weeks) kidneys of inbred (C57BL/6J) and outbred (CD-1) mice. Using quantitative polymerase chain reaction (PCR), we evidenced two mRNA patterns during tubular maturation in C57 mice. The AQPs 1-7-11 showed an early (from E14.5) and progressive increase to adult levels, similar to the mRNA pattern observed for proximal tubule markers (Megalin, NaPi-IIa, OAT1) and reflecting the continuous increase in renal cortical structures during development. By contrast, AQPs 2-3-4 showed a later (E15.5) and more abrupt increase, with transient postnatal overexpression. Most AQP genes were expressed earlier and/or stronger in maturing CD-1 kidneys. Furthermore, adult CD-1 kidneys expressed more AQP2 in the collecting ducts, which was reflected by a significant delay in excreting a water load. The expression patterns of proximal vs. distal AQPs and the earlier expression in the CD-1 strain were confirmed by immunoblotting and immunostaining. These data (1) substantiate the clustering of important genes during tubular maturation and (2) demonstrate that genetic variability influences the regulation of the AQP gene family during tubular maturation and water handling by the mature kidney.
Assuntos
Aquaporinas/genética , Aquaporinas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Variação Genética/genética , Rim/crescimento & desenvolvimento , Rim/metabolismo , Família Multigênica/genética , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos EndogâmicosRESUMO
According to the World Health Organization (WHO), Plasmodium falciparum is the deadliest parasite among all species. This parasite possesses the ability to sense molecules, including melatonin (MEL) and cAMP, and modulate its cell cycle accordingly. MEL synchronizes the development of this malaria parasite by activating several cascades, including the generation of the second messenger cAMP. Therefore, we performed RNA sequencing (RNA-Seq) analysis in P. falciparum erythrocytic stages (ring, trophozoite and schizont) treated with MEL and cAMP. To investigate the expression profile of P. falciparum genes regulated by MEL and cAMP, we performed RNA-Seq analysis in three P. falciparum strains (control, 3D7; protein kinase 7 knockout, PfPK7-; and PfPK7 complement, PfPK7C). In the 3D7 strain, 38 genes were differentially expressed upon MEL treatment; however, none of the genes in the trophozoite (T) stage PfPK7- knockout parasites were differentially expressed upon MEL treatment for 5 hours compared to untreated controls, suggesting that PfPK7 may be involved in the signaling leading to differential gene expression. Moreover, we found that MEL modified the mRNA expression of genes encoding membrane proteins, zinc ion-binding proteins and nucleic acid-binding proteins, which might influence numerous functions in the parasite. The RNA-Seq data following treatment with cAMP show that this molecule modulates different genes throughout the intraerythrocytic cycle, namely, 75, 101 and 141 genes, respectively, in the ring (R), T and schizont (S) stages. Our results highlight P. falciparum's perception of the external milieu through the signaling molecules MEL and cAMP, which are able to drive to changes in gene expression in the parasite.
RESUMO
Haplotype, allele frequencies and population data of nine Y-chromosome STR loci, DYS385I, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, were determined from a sample of 69 unrelated Greek male individuals.
Assuntos
Cromossomos Humanos Y/genética , Genética Populacional , Sequências de Repetição em Tandem/genética , Impressões Digitais de DNA , Frequência do Gene , Grécia , Haplótipos , Humanos , Masculino , Reação em Cadeia da PolimeraseRESUMO
BACKGROUND: Autosomal-dominant medullary cystic kidney disease type 2 (MCKD2) and familial juvenile hyperuricemic nephropathy (FJHN) are heritable renal diseases with autosomal-dominant transmission and shared features, including polyuria, progressive renal failure, and abnormal urate handling, which leads to hyperuricemia and gout. Mutations of the UMOD gene, disrupting the tertiary structure of uromodulin, cause MCKD2 and FJHN. METHODS: Haplotype analysis of a large Spanish family with MCKD was carried out to determinate genetic linkage to MCKD2 locus. Mutation detection was performed by direct sequencing of the UMOD gene. The level of Tamm-Horsfall protein in the urine was measured by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. RESULTS: Linkage to MCKD2 locus was demonstrated (LOD score: 4.13), and a known pathogenic uromodulin mutation was found in exon 4, corresponding to Cys255Tyr, disrupting the light chain binding domain of the protein. In this consanguineous family there were three patients homozygous for the C255Y mutation, and multiple heterozygous cases, allowing the MCKD phenotypes associated with one or two mutant alleles to be compared. The homozygous individuals survived to adulthood, although presenting an earlier onset of hyperuricemia and faster progression to end-stage renal disease than heterozygous individuals. Western analysis revealed lower levels of urine THP in one heterozygous patient compared with a normal control patient, both with normal renal function. CONCLUSION: The study shows that individuals with two UMOD mutations are viable, but they do have more severe disease on average than heterozygotes. This family sheds light on the possible disease mechanism in this disorder.