Integrins Were Involved in Soybean Agglutinin Induced Cell Apoptosis in IPEC-J2.

Li Pan,Nan Bao,Guixin Qin,Mohammed Hamdy Farouk,Yuan Zhao,Tao Wang

doi:10.3390/ijms19020587

Abstract

Soybean agglutinin (SBA), is a non-fiber carbohydrate related protein and a major anti-nutritional factor. Integrins, transmembrane glycoproteins, are involved in many biological processes. Although recent work suggested that integrins are involved in SBA-induced cell-cycle alterations, no comprehensive study has reported whether integrins are involved in SBA-induced cell apoptosis (SCA) in IPEC-J2. The relationship between SBA and integrins are still unclear. We aimed to elucidate the effects of SBA on IPEC-J2 cell proliferation and cell apoptosis; to study the roles of integrins in IPEC-J2 normal cell apoptosis (NCA) and SCA; and to illustrate the relationship and connection type between SBA and integrins. Thus, IPEC-J2 cells were treated with SBA at the levels of 0, 0.125, 0.25, 0.5, 1.0 or 2.0 mg/mL to determine cell proliferation and cell apoptosis. The cells were divided into control, SBA treated groups, integrin inhibitor groups, and SBA + integrin inhibitor groups to determine the integrin function in SCA. The results showed that SBA significantly (p < 0.05) lowered cell proliferation and induced cell apoptosis in IPEC-J2 (p < 0.05). Inhibition of any integrin type induced the cell apoptosis (p < 0.05) and these integrins were involved in SCA (p < 0.05). Even SBA had no physical connection with integrins, an association was detected between SBA and α-actinin-2 ACTN2 (integrin-binding protein). Additionally, SBA reduced the mRNA expression of integrins by down regulating the gene expression level of ACTN2. We concluded an evidence for the anti-nutritional mechanism of SBA by ACTN2 with integrins. Further trials are needed to prove whether ACTN2 is the only protein for connecting SBA with integrin.

Highlights

Soybean agglutinin (SBA), known as lectin, is a major anti-nutritional factor that represents 5–7% in soybean
The results showed that the SBA could not induce cell apoptosis in addition of integrin inhibitors, indicating that integrins α2, α3, α6, β1 and β4 were involved in SBA-induced cell apoptosis (SCA) in IPEC-J2
The results showed that integrins had no direct association with SBA, which was different from Hadari et al [25], who indicated that Galectin-8, termed S-type lectins, can bind to integrin α3, α6 and β1 and inhibit cell adhesion and induce cell apoptosis

Summary

Introduction

Soybean agglutinin (SBA), known as lectin, is a major anti-nutritional factor that represents 5–7% in soybean. As the structure of SBA has stable characteristics [1], such anti-nutritional factor can resist the enzymatic digestion, and induce deleterious toxic or side effects, including influencing immune response (T lymphocytes activation, inflammation and destroying cancerous cells), interaction between cell-to-cell, cell migration, apoptosis, division, cell proliferation, and signal transduction [1,2,3]. The specific binding of SBA to the intestinal epithelial cells surfaces is the precondition for deleterious toxic or side effects [6]. Weaned pigs supplemented high levels of SBA can bind to intestinal epithelial cell, reduce the epithelial tight junction protein (occludin) expression and increase the mucosal permeability [7]. Of SBA to the intestinal epithelial cells surfaces is the precondition for deleterious toxic or side effects [6]. Weaned pigs supplemented high levels of SBA can bind to intestinal Ienpt.itJ.hMeloila. Sl cci.el2l,01th8,e1n9,r5e8d7 uce the epithelial tight junction protein (occludin) expression and increas2eotfh1e8 mucosal permeability [7]

Objectives

Methods

Discussion

Conclusion