S-layer Protein Mediate Effect Of Lactobacillus Acidophilus On Intestinal Epithelial Cell Apoptosis

Neonatal necrotizing enterocolitis(NEC)is a high incidence of disease at premature and low birth weight babies,and has a high mortality rate,often lead to gastric distention,gastric retention,intestinal pneumatosis,vomiting,blood in the stool,even more,serious intestinal necrosis,intestinal perforation,shock,but has no effective prevention and treatment methods.In recent years doctors and scholars has studied means of prevention and treatment.The micro ecological preparation is a hot research topic.Probiotic lactic acid bacteria are common in the human gut,which can help quickly establish neonatal intestinal flora and inhibit the proliferation of pathogenic bacteria,regulating immunity,thereby reducing the incidence and risk of NEC.S-protein is a protein molecule on the surfaceo of lactic acid bacteria,the molecular weight of which is between 25?71 kDa,and the isoelectric point is between 9.35?10.04.It is known that S-layer protein plays an important role in lactic acid bacteria colonization,but also can inhibit the pathogenic bacteria of intestinal adhesion and invasion.But it is few studies that the S-layer protein inhibits apoptosis of intestinal epithelial cells.The experiment was that to explore the possible influencet of S-layer protein of Lactobacillus acidophilus in NEC,we treated newborn SD rats with hypoxic and cold stimulation,caused inflammation of NEC,and use Lactobacillus acidophilus and removal S-layer protein Lactobacillus acidophilus for prevention and intervention.In addition,based on apoptosis of the Caco-2 cell model induction by TNF-a,we reseashed the function of S-layer protein on immune regulation.First,establish rat NEC model and contrast model group with normal group,found that eosinophils lactobacillus can promote the growth and development of neonatal rats.H-E staining results can be seen feeding Lactobacillus acidophilus(removal S-layer protein Lactobacillus acidophilus),NEC onset of severe significantly improved.The pathological study score was 2.06,2.20.TEM results indicated that Lactobacillus acidophilus has good prevention and treatment effect on NEC.Secondly,Lactobacillus acidophilus can effectively reduce intestinal epithelial cell apoptosis rate,reduce TNF-?,IL-6 production and increased IL-8 production.Analysis for variance analysis can be speculated that Lactobacillus acidophilus S-layer protein was involved in the suppression of NEC,and reduced the generation of TNF-a.Then,optimal purification conditionbe of addicted to Lactobacillus acidophilus S-layer protein on Sephadex G-75:eluent pH 9.5,elution liquid flow rate of 1.5 ml/min,0.5 mg/ml sample concentration,sample volume 6 ml.Finally,Caco-2 cell model test show that S-layer protein is addicted to Lactobacillus acidophilus important adhesion.When S-layer protein filled adhesion in Caco-2 cells,there was not enough adhesion sites for Lactobacillus acidophilus,and the adhesion rate declined 79.93%.In Caco-2 cell apoptosis experiment,S-layer protein can significantly reduce the apoptosis rate,and reduce the generation of IL-6,increase the generation of IL-8,and then after the addition of LPS can effectively inhibit the production of caspase-3.