Maternal green tea polyphenol intake during lactation attenuates kidney injury in high-fat-diet-fed male offspring programmed by maternal protein restriction in rats

Abstract

Maternal malnutrition is known to increase the risk of obesity in offspring. We investigated whether green tea extract (GTE) intake during lactation affects obesity-related fibrosis and inflammation in the kidney of high-fat-diet-fed adult offspring of protein-restricted-diet-fed dams during pregnancy and lactation. Pregnant Wistar rats received diets containing 20% (normal-protein, NP) or 8% (low-protein, LP) casein, and they received 0%-, 0.12%- or 0.24%-GTE-containing LP diets (LP/LP, LP/LGT and LP/HGT, respectively) during lactation. At weaning, the pups that received a diet providing 13% (normal-fat, NF) or 45% (high-fat, HF) energy from fat were divided into five groups: NP/NP/NF, LP/LP/NF, LP/LP/HF, LP/LGT/HF and LP/HGT/HF. At week 45, the degree of fibrosis; macrophage infiltration; protein expression levels of TGF-β; and mRNA levels of TNF-α, DNMT, UHRF1 and histone lysine methyltransferase (G9a) in the kidneys of male offspring were examined. The area of fibrosis and TGF-βlevels increased in the LP/LP/HF group. Conversely, the fibrotic areas and TGF-β levels in the LP/HGT/HF group decreased (33% and 31%, respectively) compared with those in the LP/LP/HF group. The number of macrophages and mRNA levels of TNF-α in the LP/HGT/HF group decreased (34% and 29%, respectively) compared with those in the LP/LP/HF group. DNMT1, UHRF1 and G9a mRNA levels in the LP/HGT/HF group decreased compared with those in the LP/LP/HF group. In conclusion, GTE intake during lactation attenuated tubulointerstitial fibrosis and macrophage infiltration by down-regulating epigenetic modulators such as DNMT1, UHRF1 and G9a in the kidney of HF-diet-fed adult offspring programmed by maternal protein restriction.