The intestinal epithelium faces complicated luminal environment and is prone to oxidative damage induced by ingested materials and microbial pathogens. Disruption of redox balance and proliferation in the intestinal epithelium can contribute to the development of various intestinal diseases.

Previous studies indicated that dietary supplemented L-serine had strong anti-oxidant effects on the liver of many kinds of rodent models of oxidative stress. Additionally, L-serine availability has been suggested to influence mitochondrial function and cellular respiration in proliferating cells.

However, whether exogenous L-serine has any beneficial effects on redox status and cell growth in the intestine that are under oxidative stress remains unknown.

Researchers in the Institute of Subtropical Agriculture (ISA) of the Chinese Academy of Sciences conducted in vivo and in vitro experiments to investigate the role of L-serine deficiency and exogenous L-serine supplementation in the maintenance of intestinal redox balance and cell proliferation in the normal mammalian intestine and the related mechanisms.

In their study, mice under oxidative stress were fed a L-serine-deficient diet, while intestinal porcine epithelial cells (IPEC-J2) under oxidative stress were cultured with either L-serine-deficient or L-serine-supplemented medium.

The researchers found that L-serine deficiency exacerbated oxidative stress, apoptosis, and inhibition of proliferation in the intestine of mice and IPEC-J2 cells challenged by hydrogen peroxide, while L-serine supplementation rescued redox imbalance and proliferation defects.

They also found that serine alleviated oxidative stress through supporting glutathione synthesis and activating nuclear factor erythroid-2 related factor 2 signaling.

Furthermore, the mammalian target of rapamycin pathway played a critical role in the effects of serine on promoting proliferation.

"Our findings shed new light on the application of L-serine in the prevention and treatment of oxidative stress-related diseases in intestine" said ZHOU Xihong, a researcher in ISA.

The study entitled "Serine is required for the maintenance of redox balance and proliferation in the intestine under oxidative stress" was published in The FASEB Journal. It was supported by the National Natural Science Foundation of China.

Contact: Zhou,Xihong 

Email: xhzhou@isa.ac.cn

Institute of Subtropical Agriculture, The Chinese Academy of Science