DANUBIA SILVA DOS SANTOS
Projetos de Pesquisa
Unidades Organizacionais
FM, Faculdade de Medicina - Docente
LIM/13 - Laboratório de Genética e Cardiologia Molecular, Hospital das Clínicas, Faculdade de Medicina
LIM/13 - Laboratório de Genética e Cardiologia Molecular, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
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- Cardioprotection conferred by sodium-glucose cotransporter 2 inhibitors: a renal proximal tubule perspective(2020) SANTOS, Danubia Silva dos; POLIDORO, Juliano Z.; BORGES-JUNIOR, Flavio A.; GIRARDI, Adriana C. C.Sodium-glucose cotransporter 2 (SGLT2) inhibitors, also known as gliflozins, improve glycemia by suppressing glucose reuptake in the renal proximal tubule. Currently, SGLT2 inhibitors are primarily indicated as antidiabetic agents; however. their benefits extend far beyond glucose control. Cardiovascular outcome trials indicated that all studied SGLT2 inhibitors remarkably and consistently reduce cardiovascular mortality and hospitalization for heart failure (HF) in type 2 diabetes (T2D) patients. Nevertheless. the mechanisms underlying the unprecedented cardiovascular benefits of gliflozins remain elusive. Multiple processes that directly or indirectly improve myocardial performance may be involved, including the amelioration of proximal tubular dysfunction. Therefore. this paper provides a perspective on the potential cellular and molecular mechanisms of the proximal tubule that may, at least in part, mediate the cardioprotection conferred by SGLT2 inhibitors. Specifically, we focus on the effects of SGLT2 on extracellular volume homeostasis, including its plausible functional and physical association with the apical Na+/H+ exchanger isoform 3 as well as its complex and its possible bidirectional interactions with the intrarenal angiotensin system and renal sympathetic nervous system. We also discuss evidence supporting a potential benefit of gliflozins in reducing cardiovascular risk, attributable to their effect on proximal tubule handling of uric acid and albumin as well as in erythropoietin production. Unraveling the mechanisms behind the beneficial actions of SGLT2 inhibitors may not only contribute to a better understanding of the pathophysiology of cardiovascular diseases but also enable repurposing of gliflozins to improve the routine management of HF patients with or without T2D.
- Empagliflozin Inhibits Proximal Tubule NHE3 Activity, Preserves GFR, and Restores Euvolemia in Nondiabetic Rats with Induced Heart Failure(2021) BORGES-JUNIOR, Avio A.; SANTOS, Danubia Silva dos; BENETTI, Acaris; POLIDORO, Juliano Z.; WISNIVESKY, Aline C. T.; CRAJOINAS, Renato O.; ANTONIO, Ednei L.; JENSEN, Leonardo; CARAMELLI, Bruno; MALNIC, Gerhard; TUCCI, Paulo J.; GIRARDI, Adriana C. C.Background SGLT2 inhibitors reduce the risk of heart failure (HF) mortality and morbidity, regardless of the presence or absence of diabetes, but the mechanisms underlying this benefit remain unclear. Experiments with nondiabetic HF rats tested the hypothesis that the SGLT2 inhibitor empagliflozin (EMPA) inhibits proximal tubule (PT) NHE3 activity and improves renal salt and water handling. Methods Male Wistar rats were subjected to myocardial infarction or sham operation. After 4 weeks, rats that developed HF and sham rats were treated with EMPA or untreated for an additional 4 weeks. Immunoblotting and quantitative RT-PCR evaluated SGLT2 and NHE3 expression. Stationary in vivo microperfusion measured PT NHE3 activity. Results EMPA-treated HF rats displayed lower serum B-type natriuretic peptide levels and lower right ventricle and lung weight to tibia length than untreated HF rats. Uponsaline challenge, the diuretic and natriuretic responses of EMPA-treated HF rats were similar to those of sham rats and were higher than those of untreated HF rats. Additionally, EMPA treatment prevented GFR decline and renal atrophy in HF rats. PT NHE3 activity was higher in HF rats than in sham rats, whereas treatment with EMPA markedly reduced NHE3 activity. Unexpectedly, SGLT2 protein and mRNA abundance were upregulated in the PT of HF rats. Conclusions Prevention of HF progression by EMPA is associated with reduced PTNHE3 activity, restoration of euvolemia, and preservation of renal mass. Moreover, dysregulation of PT SGLT2 may be involved in the pathophysiology of nondiabetic HF.