Efeitos da dieta hipoproteica na expressão dos fatores transcricionais NRF2 e NF-KB em pacientes com doença renal crônica em tratamento conservador

Abstract

Background: Low protein diet (LPD) (0.6 g/Kg/day) prescribed for non-dialysis patients has been demonstrated numerous benefits and it may modulate inflammation and oxidative stress through nuclear factor erythroid 2 - related factor 2 (Nrf2), which encodes antioxidant and phase II detoxifying enzymes, and it is able to inhibit / antagonize nuclear factor-kB (NF-kB) activity, which orchestrates inflammatory and oxidative stress response. However, no study has evaluated the effect of this diet on the modulation of such transcription factors. The objective of this study was to evaluate the effects of LPD on Nfr2 and NF-kB mRNA expression in non-dialysis CKD patients. Methods: In this longitudinal study, LPD was prescribed for 30 non-dialysis CKD patients (referred to the Renal Nutrition Clinic (UFF)) for six months (55.5 ± 14.0 years, BMI, 29.1 ± 5.9 kg/m2, glomerular filtration rate, 35.6 ± 12.2 mL/min). The peripheral blood mononuclear cells (PBMC) were isolated and quantitative Real-Time PCR analysis were performed to evaluate the Nrf2, NF-kB and NQO1 mRNA expression. The nutritional status was evaluated by Dual-energy X-ray absorptiometry (DXA). Thiobarbituric acid-reactive substances (TBARS) levels, a marker of lipid peroxidation, were also evaluated. Biochemical parameters were evaluated in automation device with BioClin® kits. Results: After 6 months of nutritional intervention, Nrf2 mRNA expression was increased from 0.85 (0.47-1.56) to 1.28 (0.63-2.63) (p = 0.03) and TBARS levels were significantly decreased from 1.78 (1.31-2.38) to 1.30 (1.07-2.22) nmol/mL (p = 0.04). NF-kB mRNA expression showed no significant difference after 6 months, but the Nrf2/NF-kB ratio was increased. Conclusion: Based on these results, LPD seems to modulate the Nrf2 expression and decrease the levels of TBARS in nondialysis CKD patients. However, more studies are needed to confirm the effectiveness of LPD in the modulation of transcriptor factors involved with oxidative stress and inflammation in non-dialysis CKD patients.