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Activation of Nrf2‐Antioxidant Signaling by 1,25‐Dihydroxyvitamin D 3 Prevents Leptin‐Induced Oxidative Stress and Inflammation in Human Endothelial Cells
Author(s) -
Daleprane Julio,
Texeira Thaisa,
Bezerra Flavia
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.644.4
Subject(s) - leptin , oxidative stress , chemistry , viability assay , sod2 , gene knockdown , medicine , inflammation , endocrinology , reactive oxygen species , small interfering rna , mtt assay , superoxide dismutase , cell , biology , biochemistry , apoptosis , transfection , gene , obesity
Obesity is associated with hyperleptinemia and endothelial dysfunction. The present work aimed to evaluate the role of 1,25‐Dihydroxyvitamin D3 in protect endothelial cells against leptin‐induced oxidative stress and inflammation. In order to evaluate this hypothesis, cell viability in the presence of 1,25(OH) 2 D 3 and leptin was determinate using MTT assay, we also used small interfering RNA (siRNA) to knockdown the expression of VDR in HUVEC. Endothelial cells were pre‐treated with physiologic (10 −10 M) and supraphysiologic (10 −7 M) concentrations of 1,25(OH) 2 D 3 and exposed to leptin. Quantification of superoxide anion (O 2 •− ) production, translocation of NRF2 and of NF‐ΚB subunit p65 to the nucleus and the activation of their target genes were performed. In 1,25(OH) 2 D 3 pre‐treated (both at physiologic and supraphysiologic concentrations) endothelial cells, the viability did not decrease in the presence of 10 ng/mL of leptin demonstrating a protective effect of 1,25(OH) 2 D 3 against leptin‐induced cytotoxicity. When siRNA‐VDR cells were pretreated with 1,25(OH) 2 D 3 and exposed to leptin (10 μg/mL), it was observed that 1,25(OH) 2 D 3 did not prevent cell death, demonstrating a protective effect of 1,25(OH) 2 D 3 dependent of VDR. Pretreatment of HUVEC with 1,25(OH) 2 D 3 prevented the leptin‐induced increase in O 2 •− production. I was observed that 1,25(OH) 2 D 3 further increased Nrf2 translocation to the nucleus and stimulated transcription of its target genes such as SOD2 , GPX , NQO1 and HMOX1 . Leptin enhanced the translocation to the nucleus of the major inflammatory transcription factor NF‐ΚB and increased the production of vascular inflammatory mediators, including interleukin (IL)‐6, TNF‐α and IL‐13, which were prevented by pretreatment with 1,25(OH) 2 D 3 . These findings suggest that pretreatment with 1,25(OH) 2 D 3 in the presence of high concentration of leptin, have a positive effect on the endothelium through the regulation of mediators of antioxidant activity and inflammation. Support or Funding Information This study was supported by funding from National Council of Scientific and Technological Development (CNPq, Protocol 472711/2013‐0) and Rio de Janeiro State Research Agency (FAPERJ; Protocol E‐26/010.002632/2014).