孕前和孕期维生素D缺乏对子代大鼠肠道菌群及抗菌肽cathelicidin的影响

Effects of maternal vitamin D deficiency before and during pregnancy on intestinal flora and cathelicidin antimicrobial peptide expression in offspring rats

目的·探讨孕前和孕期维生素D缺乏对子代大鼠肠道菌群及抗菌肽cathelicidin(cathelicidin antimicrobial peptide,CAMP)的影响。方法·将24只8周龄雌性SD大鼠分为3组,对照组(C组)、维生素D缺乏组(VDD组)及维生素D补充组(VDS组)各8只。通过特殊饲料饮食构建大鼠孕前和孕期维生素D缺乏模型。母鼠孕第14日用液相色谱-串联质谱联用法检测血清25(OH)D水平。子鼠4周龄时,取血检测25(OH)D水平;取粪便检测肠道菌群;取结肠组织,用实时荧光定量RT-q PCR法、Western blotting法分别测定大鼠CAMP的mRNA及蛋白表达水平。结果·大鼠孕前和孕期维生素D缺乏模型构建成功。C组、VDD组及VDS组子鼠肠道乳酸杆菌的相对丰度分别为0.050±0.016、0.028±0.013及0.033±0.021。与C组相比,VDD组子鼠肠道乳酸杆菌的相对丰度显著降低(P<0.05),结肠CAMP的mRNA及蛋白表达水平亦显著降低(均P<0.05)。与VDD组相比,VDS组子鼠肠道乳酸杆菌的相对丰度有升高的趋势,但差异无统计学意义;结肠CAMP的mRNA表达水平无明显改变,蛋白表达水平显著升高(P<0.05)。结论·孕期维生素D缺乏可致子代大鼠结肠CAMP的mRNA及蛋白表达水平和肠道乳酸杆菌的相对丰度显著降低。孕期维生素D补充后,子代大鼠结肠CAMP的蛋白表达水平显著升高,肠道乳酸杆菌的丰度也有升高的趋势。

Objective· To explore the effects of maternal vitamin D deficiency before and during pregnancy on the intestinal flora and cathelicidin antimicrobial pepfide （CAMP） in offspring rats. Methods. Twenty-four female Sprague-Dawley rats （8-week-old） were randomly assigned to three groups （n=8 per group）, i.e. control group （C group）, vitamin D deficiency group （VDD group）, and vitamin D supplement group （VDS group）. Special diets were used to build the rat models of vitamin D deficiency before and during pregnancy. Maternal 25（OH）D level was detected by liquid chromatography tandem mass spectrometry （LC-MS/MS） at gestational day 14. At the age of 4 weeks in offsprings, the level of 25（OH）D was measured; the faeces were collected for the detection of intestinal flora; the mRNA and protein expression of CAMP were evaluated by real-time quantitative RT- PCR and Western blotting, respectively. Results · The rat models of vitamin D deficiency before and during pregnancy were successfully established. The relative abundance of intestinal Lactobacillus in the offspring rats in C group, VDD group and VDS group was 0.050·0.016, 0.028·0.013 and 0.033·-0.021, respectively. Compared with C group, the relative abundance of intestinal Lactobacillus in VDD group significantly decreased （P〈0.05）, and the mRNA and protein expression of colonic CAMP significantly decreased as well （P〈0.05）. Compared with VDD group, VDS group showed a trend of increase in the abundance of intestinal Lactobacillus; the mRNA expression of colonic CAMP didn＇t change significantly, but the protein expression of colonic CAMP significantly increased （P〈0.05）. Conelusion· Vitamin D deficiency during pregnancy results in decreased abundance of intestinal Lactobacilli as well as reduced mRNA and protein expression of colonic CAMP in offspring rats. Vitamin D supplementation significantly improves the protein expression of colonic CAMP and induces a trend of increase in the abundance of intestinal Lactobacilli in offspring rats.