RESUMO
The renin-angiotensin-aldosterone system is a neurohormonal system responsible for maintaining homeostasis of fluid regulation, sodium balance, and blood pressure. The complexity of this pathway enables it to be a common target for blood pressure and volume-regulating medications. The mineralocorticoid receptor is one of these targets, and is found not only in the kidney, but also tissues making up the heart, blood vessels, and adipose. Mineralocorticoid receptor antagonists have been shown to slow progression of chronic kidney disease, treat refractory hypertension and primary aldosteronism, and improve morbidity and mortality in management of heart failure with reduced ejection fraction. The more well-studied medications were derived from steroid-based compounds, and thus come with a distinct side-effect profile. To avoid these adverse effects, developing a mineralocorticoid receptor antagonist (MRA) from a non-steroidal base compound has gained much interest. This review will focus on the novel non-steroidal MRA, Finerenone, to describe its unique mechanism of action while summarizing the available clinical trials supporting its use in patients with various etiologies of cardiorenal disease.
Assuntos
Antagonistas de Receptores de Mineralocorticoides , Receptores de Mineralocorticoides , Humanos , Antagonistas de Receptores de Mineralocorticoides/efeitos adversos , Receptores de Mineralocorticoides/metabolismo , Naftiridinas/efeitos adversos , Sistema Renina-AngiotensinaRESUMO
We compared viral suppression rates between patients who continued tenofovir disoproxil fumarate (TDF)/lamivudine (3TC) vs switched to zidovudine (ZDV)/3TC in combination with a boosted protease inhibitor after failure of first-line efavirenz/TDF/3TC. We found higher rates of viral suppression with continued TDF/3TC compared with switching to ZDV/3TC.
RESUMO
In the thymus of non-obese diabetic (NOD) mice, the expression of the autoimmune regulator (Aire) gene varies with age, and its down-regulation in young mice precedes the later emergence of type 1 diabetes mellitus (T1D). In addition, the insulin (Ins2) peripheral tissue antigen (PTA) gene, which is Aire-dependent, is also deregulated in these mice. Based in these findings, we hypothesized that the imbalance in PTA gene expression in the thymus can be associated with slight variations in Aire transcript levels. To test this, we used siRNA to knockdown Aire by in vivo electro-transfection of the thymus of BALB/c mice. The efficiency of the electro-transfection was monitored by assessing the presence of irrelevant Cy3-labeled siRNA in the thymic stroma. Importantly, Aire-siRNA reached medullary thymic epithelial cells (mTECs) down-regulating Aire. As expected, the in vivo Aire knockdown was partial and transient; the maximum 59% inhibition occurred in 48 h. The Aire knockdown was sufficient to down-regulate PTA genes; however, surprisingly, several others, including Ins2, were up-regulated. The modulation of these genes after in vivo Aire knockdown was comparable to that observed in NOD mice before the emergence of T1D. The in vitro transfections of 3.10 mTEC cells with Aire siRNA resulted in samples featuring partial (69%) and complete (100%) Aire knockdown. In these Aire siRNA-transfected 3.10 mTECs, the expression of PTA genes, including Ins2, was down-regulated. This suggests that the expression profile of PTA genes in mTECs is affected by fine changes in the transcription level of Aire.
Assuntos
Diabetes Mellitus Tipo 1/imunologia , Células Epiteliais/imunologia , Regulação da Expressão Gênica , Timo/metabolismo , Fatores de Transcrição/genética , Transcrição Gênica , Animais , Linhagem Celular , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP1A2/metabolismo , Diabetes Mellitus Tipo 1/genética , Feminino , Humanos , Insulina/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , RNA Mensageiro/biossíntese , RNA Interferente Pequeno/genética , Timo/imunologia , Transcriptoma , Proteína AIRERESUMO
Positive selection (PS) in the thymus involves the presentation of self-peptides that are bound to MHC class II on the surface of cortical thymus epithelial cells (cTECs). Prss16 gene corresponds to one important element regulating the PS of CD4(+) T lymphocytes, which encodes Thymus-specific serine protease (Tssp), a cTEC serine-type peptidase involved in the proteolytic generation of self-peptides. Nevertheless, additional peptidase genes participating in the generation of self-peptides need to be found. Because of its role in the mechanism of PS and its expression in cTECs, the Prss16 gene might be used as a transcriptional marker to identify new genes that share the same expression profile and that encode peptidases in the thymus. To test this hypothesis, we compared the differential thymic expression of 4,500 mRNAs of wild-type (WT) C57BL/6 mice with their respective Prss16-knockout (KO) mutants by using microarrays. From these, 223 genes were differentially expressed, of which 115 had known molecular/biological functions. Four endopeptidase genes (Casp1, Casp2, Psmb3 and Tpp2) share the same expression profile as the Prss16 gene; i.e., induced in WT and repressed in KO while one endopeptidase gene, Capns1, features opposite expression profile. The Tpp2 gene is highlighted because it encodes a serine-type endopeptidase functionally similar to the Tssp enzyme. Profiling of the KO mice featured down-regulation of Prss16, as expected, along with the genes mentioned above. Considering that the Prss16-KO mice featured impaired PS, the shared regulation of the four endopeptidase genes suggested their participation in the mechanism of self-peptide generation and PS.
Assuntos
Perfilação da Expressão Gênica , Estudos de Associação Genética , Peptídeos/imunologia , Serina Endopeptidases/genética , Timo/imunologia , Transcrição Gênica , Animais , Análise por Conglomerados , Células Epiteliais/enzimologia , Regulação da Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Anotação de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Serina Endopeptidases/metabolismoRESUMO
Considering that imbalance of central tolerance in the thymus contributes to aggressive autoimmunity, we compared the expression of peripheral tissue autoantigens (PTA) genes, which are involved in self-representation in the thymic stroma, of two mouse strains; DBA-1/J (MHC-H2(q)) susceptible and DBA-2/J (MHC-H2(d)) resistant to collagen induced arthritis (CIA). We evaluate whether these strains differ in their thymic gene expression, allowing identification of genes that might play a role in susceptibility/resistance to CIA. Microarray profiling showed that 1093 PTA genes were differentially modulated between collagen immunized DBA-1/J and DBA-2/J mice. These genes were assigned to 17 different tissues/organs, including joints/bone, characterizing the promiscuous gene expression (PGE), which is implicated in self-representation. Hierarchical clustering of microarray data and quantitative RT-PCR analysis showed that Aire (autoimmune regulator), an important regulator of the PGE process, Aire-dependent (insulin), Aire-independent (Col2A1 and Gad67), and other 22 joint/bone autoantigen genes were down-regulated in DBA-1/J compared with DBA-2/J in the thymus. Considering the importance of MHC-H2 in peptide-self presentation and autoimmunity susceptibility, we reconstructed transcriptional networks of both strains based on actual microarray data. The networks clearly demonstrated different MHC-H2 transcriptional interactions with PTAs genes. DBA-1/J strain featured MHC-H2 as a node influencing downstream genes. Differently, in DBA-2/J strain network MHC-H2 was exclusively self-regulated and does not control other genes. These findings provide evidence that CIA susceptibility in mice may be a reflex of a cascade-like transcriptional control connecting different genes to MHC-H2 in the thymus.
Assuntos
Artrite Experimental/genética , Artrite Experimental/imunologia , Autoantígenos/metabolismo , Redes Reguladoras de Genes , Timo/metabolismo , Animais , Artrite Experimental/metabolismo , Autoantígenos/genética , Autoantígenos/imunologia , Células Cultivadas , Biologia Computacional , Perfilação da Expressão Gênica , Redes Reguladoras de Genes/imunologia , Antígenos de Histocompatibilidade/metabolismo , Camundongos , Camundongos Endogâmicos DBA , Análise em Microsséries , Tolerância a Antígenos Próprios , Especificidade da Espécie , Timo/imunologia , Timo/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína AIRERESUMO
In this study, we observed the occurrence of TRBV8.1-DB2.1 V(D)J recombination in murine fetal thymus organ culture (FTOC), in which the thymic microenvironment is mimicked. Since ionizing radiation affects T-cell development, we irradiated FTOCs with gamma rays to evaluate the modulation of genes implicated in TRBV8.1-BD2.1 rearrangements. The nylon cDNA microarray method was employed to monitor the expression of 9216 genes, which were organized in coexpression clusters. Clustering analysis showed similar expression profiling of genes implicated in the V(D)J recombination and DNA double strand break (DSB) repair processes such as XRCC4, RAG-2, Artemis and DNA-PK-cs, thus suggesting overlap between the two processes. The RUNX3 gene, whose coded protein binds to the enhancers of TR genes, was also modulated and the DNA cross-linking LR1 gene, which plays a role in the opening of hairpin DNA structures and whose expression pattern is similar to Artemis, may play a role in the control of V(D)J recombination. Furthermore, our data demonstrate that the FTOC model system and cDNA microarray method are useful tools to evidentiate genes that may play a role in both processes V(D)J recombination and DNA repair.
Assuntos
Reparo do DNA/genética , Perfilação da Expressão Gênica , Timo/efeitos da radiação , VDJ Recombinases/metabolismo , Animais , Diferenciação Celular , Análise por Conglomerados , DNA Complementar/genética , Raios gama , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T , Camundongos , Camundongos Endogâmicos BALB C , Hibridização de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos , Técnicas de Cultura de Órgãos , Reação em Cadeia da Polimerase/métodos , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T/citologia , Linfócitos T/efeitos da radiação , Timo/embriologia , Timo/metabolismoRESUMO
The CBA/J inbred mouse strain constitutes an interesting in vivo model-system for studies on molecular genetics of thymus ontogeny. Using RT-PCR method we have found previously that several immune system related genes as interleukins and MHC are differentially expressed. During this period the onset of T-cell receptor beta rearrangements also occur. To know which other genes are modulated during the ontogeny of the thymus, the mRNA expression levels of fetal thymus (15 and 16 days gestation) of CBA/J mouse strain were measured by hybridization with a set of four macroarrays containing a panel of 6,144 IMAGE cDNA clones from MTB thymus library. We found 145 differentially expressed sequences; 44 were up- and 101 down-regulated in the thymus at 15-16 days gestation. Among these sequences, only 20 are identified as genes whose functions are known and 125 are still unknown. Our data demonstrated that, despite intense research on maturation of the immune system focusing on the activity of several well-characterized genes, the large scale expression profile during thymus ontogeny is still an open matter. The use of cDNA-array technology is an affordable method to identify new genes that may play a role in this phenomenon.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Timo/metabolismo , Animais , Feminino , Perfilação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos CBA , Timo/embriologiaRESUMO
The V(D)J recombination of TCRalpha and beta in early developing T-cells is a highly modulated phenomenon initiated and completed by recombinase complex (RAG-1 and RAG-2), and regulated by other gene products such as interleukins. To further evaluate the association of several other gene products with the evolution of TCRVbeta8.1 V(D)J rearrangements in vivo, the mRNA expression levels of seven interleukins, three cytokines, receptors TCRVbeta8.1 and IL-2Rbeta, MHC-I/MHC-II, RAG-1/ RAG-2 and retroviral superantigen MMTV(SW) were measured by RT-PCR during the fetal development of the thymus of three inbred mouse strains (Balb-c, C57B1/6 and CBA/J). Clustering using the Tree View software, was used to organize these genes based on similarity of expression patterns. Each strain displayed a different expression profile during thymus ontogeny. During the late developmental stage the most evident association was the kinetics of MMTV(SW) retrovirus, IL-2Rbeta and IL-7 overexpression with reduction of TCRVbeta8.1-D1beta2.1 rearrangement in the thymus of CBA/J mice. These data suggest a susceptibility of this strain to expression of MMTV(SW) upon reduction of the rearranged TCRVbeta8.1-Dbeta2.1 segment in developing thymocytes, with parallel IL-7 overexpression.