ABSTRACT
OBJECTIVE To construct an insulin-resistant(IR)small intestinal organoid model of mice and study the protective effect of flavanomarein(FM)on the intestinal mucosal barrier in the model.METHODS ①Small intestinal organoid models of C57BL/6J and db/db of mice were constructed.The expressions of Ki-67,E-cadherin(E-cad),lysozyme(Lyz)and mucin-2(Muc-2)in small intestinal organ-oids were detected by 3D immunofluorescence.RT-qPCR was used to detect the expressions of fibro-nectin(Fn),glucagon-like peptide-1(GLP-1)and peotide YY(PYY)mRNA while Western blotting was used to detect the expressions of Fn,GLP-1 and PYY protein.The Lyz secretion level was detected by ELISA.② Small intestinal organoids were divided into five groups:C57BL/6J mice 'small intestinal organ-oids as the normal control group,db/db mice' intestinal organoids as the IR model group,db/db mice small intestinal organoids with flavanomarein 25,50 and 100 μmol·L-1 intervention for 48 h as IR model+ FM groups.RT-qPCR was used to detect the expression of Lyz mRNA while Western blotting was used to detect the expression of Lyz protein.RESULTS ① On the 6th day of small intestinal organoid culture,a ring structure with a clear luminal structure was formed and an IR mouse small intestinal organoid model was established.3D Immunofluorescence detection showed that the established small intestinal organoids all expressed Ki-67,E-cad,Lyz and MUC-2.Compared with the normal control group,the expres-sion of Fn mRNA in the IR model group was significantly increased(P<0.05)while the expressions of GLP-1 and PYY mRNA were significantly decreased(P<0.05).Compared with the normal control group,the expression of Fn protein in the IR model group was significantly decreased(P<0.05)while the expressions of GLP-1 and PYY protein were significantly increased(P<0.05).ELISA results showed that compared with the normal control group,the secretion levels of Lyz in the IR model group were signifi-cantly decreased(P<0.01).② RT-qPCR results showed that compared with the normal control group,the expression of Lyz mRNA in the IR model group was significantly decreased(P<0.01).Compared with the IR model group,the expression of Lyz mRNA in the IR model+FM 50 and 100 μmol·L-1 groups was significantly increased(P<0.05,P<0.01).Western blotting results showed that compared with the normal control group,the expression of Lyz protein in the IR model group was significantly decreased(P<0.01).Compared with the IR model group,the expression of Lyz protein in the IR model+FM 50 and 100 μmol·L-1 groups was significantly increased(P<0.05,P<0.01).CONCLUSION The constructed IR mouse small intestinal organoid model provides a more complete in vitro research model for exploring the pathophysiological mechanism by which drug interventions help repair the intestinal mucosal barrier.FM may maintain the intestinal mucosal barrier by reversing the decrease in Lyz expression levels in IR mice,thereby improving IR.