β-Carotene Attenuates Apoptosis and Autophagy via PI3K/AKT/mTOR Signaling Pathway in Necrotizing Enterocolitis Model Cells IEC-6

Abstract

Background. Necrotizing enterocolitis (NEC) is a devastating disease affecting the gastrointestinal tract in the newborn period. In recent years, the role of apoptosis and autophagy in intestinal mucosal barrier dysfunction has come into prominence in research regarding the pathogenesis of NEC. β-Carotene is a well-known vitamin A precursor, and its content in breast milk is relatively high, especially in the colostrum. In the present study, we investigated the protective effect of β-carotene on necrotizing enterocolitis model cells IEC-6 induced by lipopolysaccharide (LPS). Methods. CCK-8 assay was performed to evaluate cell viability. The Annexin V-FITC/PI method was used to detect apoptosis. Western blotting was utilized to measure the expression levels of proteins. Immunofluorescence analysis was used to assess the autophagy of IEC-6 cells. Results. Our findings indicated that β-carotene inhibited the apoptosis of IEC-6 cells by downregulating cleaved caspase-3 levels and Bax levels and upregulating Bcl-2 levels, reducing cell autophagy via downregulating LC3II/I ratio and upregulating p62 levels. In addition, the expression of p-PI3K, p-AKT, and p-mTOR was upregulated after β-carotene treatment. Interestingly, these changes induced by β-carotene were partially reversed by rapamycin and voxtalisib. Conclusion. In conclusion, our findings indicated that β-carotene can attenuate apoptosis and autophagy of IEC-6 cells induced by LPS via activating the PI3K/AKT/mTOR signaling pathway. Therefore, β-carotene may be a promising drug used in the clinical treatment of NEC.