ABSTRACT
The dipeptidyl peptidase-4 (DPP-4) inhibitor saxagliptin has been found to reduce progressive albuminuria, but the exact mechanism of inhibition is unclear. Podocyte epithelial-to-mesenchymal transition (EMT) has emerged as a potential pathway leading to proteinuria in diabetic nephropathy (DN). Stromal cell-derived factor-1α (SDF-1α), one of the substrates of DPP-4, can activate the protein kinase A pathway and subsequently inhibit its downstream effector, transforming growth factor-ß1 (TGF-ß1), which induces podocyte EMT. Thus, this study was designed to test the hypothesis that saxagliptin reduces progressive albuminuria by preventing podocyte EMT through inhibition of SDF-1α cleavage in DN. The results of a series of assays, including ELISA, western blotting, and immunochemistry/immunofluorescence, showed that saxagliptin treatment obviously ameliorated urinary microalbumin excretion and renal histological changes in high-fat diet/streptozotocin-induced diabetic rats. Furthermore, saxagliptin-treated diabetic rats presented with suppression of DPP-4 activity/protein expression accompanied by restoration of SDF-1α levels, which subsequently hindered NOX2 expression and podocyte EMT. In vitro, we consistently observed that saxagliptin significantly inhibited increased DPP-4 activity/expression, oxidative stress and podocyte EMT. Application of an SDF-1α receptor inhibitor (AMD3100) to cultured podocytes further confirmed the essential role of SDF-1α in podocyte EMT inhibition. In sum, we demonstrated for the first time that saxagliptin treatment plays an essential role in ameliorating progressive DN by preventing podocyte EMT through a SDF-1α-related pathway, suggesting that saxagliptin could offer renoprotection and that SDF-1α might be a potential therapeutic target for DN.
ABSTRACT
Abstract Background: Cell-derived microvesicles (MVs) are vesicles released from activated or apoptotic cells. However, the levels of MVs in myocardial infarction have been found inconsistent in researches. Objective: To assess the association between MVs and myocardial infarction by conducting a meta-analysis. Methods: A systematic literature search on PubMed, Embase, Cochran, Google Scholar electronic database was conducted. Comparison of the MVs levels between myocardial infarction patients and healthy persons were included in our study. Standard Mean Difference (SMD) and 95% confidence interval (CI) in groups were calculated and meta-analyzed. Results: 11 studies with a total of 436 participants were included. Compared with the health persons, AMVs [SMD = 3.65, 95% CI (1.03, 6.27)], PMVs [SMD = 2.88, 95% CI (1.82, 3.93),] and EMVs [SMD = 2.73, 95% CI (1.13, 4.34)], levels were higher in patients with myocardial infarction. However, LMVs levels [SMD = 0.73, 95% CI (-0.57, 2.03)] were not changed significantly in patients with myocardial infarction. Conclusions: AMVs, PMVs and EMVs might be potential biomarkers for myocardial infarction.
Resumo Fundamentos: As microvesículas derivadas de células (MVs) são vesículas liberadas de células ativadas ou apoptóticas. No entanto, os níveis de MVs no infarto do miocárdio foram encontrados inconsistentes nas pesquisas. Objetivo: Avaliar a associação entre MV e infarto do miocárdio por meio de uma meta-análise. Métodos: Foi realizada uma pesquisa sistemática na literatura em PubMed, Embase, Cochran e no banco de dados eletrônico do Google Scholar. Uma comparação dos níveis de MV entre pacientes com infarto do miocárdio e pessoas saudáveis foi incluída no nosso estudo. A Diferença Média Padrão (DMP) e o intervalo de confiança (IC) de 95% nos grupos foram calculadas e meta-analisadas. Resultados: Foram incluídos 11 estudos com um total de 436 participantes. Em comparação com as pessoas saudáveis, as MVA [DMP = 3,65, IC 95% (1,03, 6,27)], MVPs [DMP = 2,88, IC 95% (1,82, 3,93)] e MVEs [DMP = 2,73, IC 95% (1,13, 4.34)], foram maiores em pacientes com infarto do miocárdio. No entanto, os níveis de MVL [DMP = 0,73, IC 95% (-0,57, 2,03)] não foram alterados significativamente em pacientes com infarto do miocárdio. Conclusões: MVAs, MVPs e MVEs podem ser biomarcadores potenciais para o infarto do miocárdio.
ABSTRACT
BACKGROUND:: Cell-derived microvesicles (MVs) are vesicles released from activated or apoptotic cells. However, the levels of MVs in myocardial infarction have been found inconsistent in researches. OBJECTIVE:: To assess the association between MVs and myocardial infarction by conducting a meta-analysis. METHODS:: A systematic literature search on PubMed, Embase, Cochran, Google Scholar electronic database was conducted. Comparison of the MVs levels between myocardial infarction patients and healthy persons were included in our study. Standard Mean Difference (SMD) and 95% confidence interval (CI) in groups were calculated and meta-analyzed. RESULTS:: 11 studies with a total of 436 participants were included. Compared with the health persons, AMVs [SMD = 3.65, 95% CI (1.03, 6.27)], PMVs [SMD = 2.88, 95% CI (1.82, 3.93),] and EMVs [SMD = 2.73, 95% CI (1.13, 4.34)], levels were higher in patients with myocardial infarction. However, LMVs levels [SMD = 0.73, 95% CI (-0.57, 2.03)] were not changed significantly in patients with myocardial infarction. CONCLUSIONS:: AMVs, PMVs and EMVs might be potential biomarkers for myocardial infarction. FUNDAMENTOS:: As microvesículas derivadas de células (MVs) são vesículas liberadas de células ativadas ou apoptóticas. No entanto, os níveis de MVs no infarto do miocárdio foram encontrados inconsistentes nas pesquisas. OBJETIVO:: Avaliar a associação entre MV e infarto do miocárdio por meio de uma meta-análise. MÉTODOS:: Foi realizada uma pesquisa sistemática na literatura em PubMed, Embase, Cochran e no banco de dados eletrônico do Google Scholar. Uma comparação dos níveis de MV entre pacientes com infarto do miocárdio e pessoas saudáveis foi incluída no nosso estudo. A Diferença Média Padrão (DMP) e o intervalo de confiança (IC) de 95% nos grupos foram calculadas e meta-analisadas. RESULTADOS:: Foram incluídos 11 estudos com um total de 436 participantes. Em comparação com as pessoas saudáveis, as MVA [DMP = 3,65, IC 95% (1,03, 6,27)], MVPs [DMP = 2,88, IC 95% (1,82, 3,93)] e MVEs [DMP = 2,73, IC 95% (1,13, 4.34)], foram maiores em pacientes com infarto do miocárdio. No entanto, os níveis de MVL [DMP = 0,73, IC 95% (-0,57, 2,03)] não foram alterados significativamente em pacientes com infarto do miocárdio. CONCLUSÕES:: MVAs, MVPs e MVEs podem ser biomarcadores potenciais para o infarto do miocárdio.
