ABSTRACT
ObjectiveTo determine the changes in tumor necrosis factor-α (TNF-α) and interleukin-lβ (IL-1β)expression after bone marrow mesenchymal stem cells (BMSCs) transplantation in a rat pup model of hypoxic-ischemic brain damage (HIBD) and discuss the anti-inflammatory mechanism of BMSCs transplantation in the repair of HIBD.MethodsThree-day-old Sprague-Dawley rat pups were randomly divided into three groups: the transplantation group, in which a model of HIBD was established by ligation of left common carotid artery and hypoxia for two hours followed by the injection of 2μl BMSCs (2×105 cells) into the lateral ventricle; the HIBD model group, in which HIBD model was established and 2μl phosphate saline buffer was injected into the lateral ventricle; and the sham-operation group, in which no intervention was given. Histological changes in the brain were detected by HE staining and the number of cells positive for ectodermal dysplasia-1 (ED-1) staining, which is a specific marker for activated microglia, was detected by immunohistochemistry. The protein and mRNA levels of TNF-α and IL-1β were determined by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction. One-way analysis of variance and LSD test were applied for statistical analysis.ResultsHE staining showed that cellular edema and necrocytosis was not observed in cerebral white matter on the 7th post-transplantation day in the transplantation group, but observed in the HIBD model group. In the sham-operation group, cerebral white matter was normal. The number of ED-1 positive cells in the transplantation group (26.3±2.5) was significantly lower than that in the HIBD model group (33.0±4.0), but higher than that in the sham-operation group (2.3±0.6) (LSD test, allP<0.05). The contents of TNF-α and IL-1β both in the transplantation group and the HIBD model group increased and peaked 24 h after transplantation, then gradually decreased, but did not reach normal levels (sham-operation group) on the 7th day. The contents of TNF-α and IL-1β in brain tissue in the HIBD model group [TNF-α: (3.03±0.10), (5.57±0.19), (7.78±0.19), (4.39±0.20), (2.70±019)μg/L; IL-1β:(293.1±7.9), (369.8±17.5), (303.6±23.9), (226.7±21.6), (183.9±33.4) ng/L] were significantly higher than those in the transplantation group [TNF-α: (2.84±0.20), (3.80±0.14), (4.63±0.17), (3.56±0.03), (1.99± 0.17)μg/L; IL-1β: (267.6±14.5), (323.5±26.9), (211.2±24.9), (140.8±7.4), (100.2±8.3) ng/L] at 6, 12, 24, 48 h and 7 days after BMSCs transplantation, respectively. The contents of TNF-α and IL-1β in the sham-operation group [TNF-α:(1.03±0.02), (1.13±0.03), (1.05±0.02), (1.09±0.02), (1.07±0.02)μg/L; IL-1β:(63.6±13.0), (64.0±11.3), (60.8±10.0), (67.9±13.5), (66.2±11.7) ng/L] were significantly lower than those in the transplantation group and HIBD model group (LSD test, allP<0.05). TNF-α and IL-1β mRNA at 24 h after transplantation in the HIBD model group (TNF-α: 2.69±0.43; IL-1β: 3.07±0.38) were significantly higher than those in the transplantation group (TNF-α: 1.61±0.29; IL-1β: 1.08±0.11) and those in the sham-operation group (TNF-α: 0.94±0.16; IL-1β: 1.08±0.11) (LSD test, allP<0.05).ConclusionsBMSCs may play an important role in the recovery of preterm HIBD and the mechanism may involve the inhibition of microglia activation and down-regulation of the expression of inflammatory factors.
ABSTRACT
Objective To analyze the influence of mode of delivery on post-neonatal gut microbiota using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technology.Methods From April to August in 2013,thirty healthy urban full-term neonates in Nanjing City were enrolled in the study,including fifteen exclusive breastfed ones (seven born of caesarean section and eight born vaginally) and fifteen mixed feeding ones (eight born of cesarean section and seven born vaginally).Stool specimens were collected on the 28th day after birth and bacterial genomic DNA was extracted and examined by PCR on 16S rDNA V3 variable region.Bacterial community profiles were obtained by DGGE.Diversity and similarity differences of the gut microbial community structures were analyzed.Two independent sample t test or Chi-square tests were used for stastistical analysis.Results (1)Diversity analysis showed that among exclusive breastfeeding infants,the Strip number and Shannon-Weaver Diversity Index of gut microbiota in infants born abdominally were significantly lower than those born vaginally [9.71 ±4.27 vs 15.12±4.19,2.13±0.39 vs 2.61±0.32,both P＜0.05],but the Simpson index of gut microbiota was significantly higher [0.13 ± 0.04 vs 0.08± 0.03,P＜0.05],and no significant difference was shown in Pielou Index (P＞0.05).In the mixed feeding group,the Strip number and Shannon-Weaver Diversity Index of gut microbiota in infants born abdominally were significantly lower than those born vaginally [10.88±3.23 vs 16.29±5.38,2.26±0.37 vs 2.66±0.31,both P＜0.05],the Simpson index was higher,but together with the Pielou Index,neither showed significant difference (both P＞0.05).(2) Similarity analysis found that gut microbiota from neonates born of same mode of delivery mostly gathered together and had much more similar structures.Conclusions In the post-neonatal period,the species and numbers of gut microbiota in infants born abdominally are all behind of those born vaginally.The predominant microbiota in babies born of cesarean section are more prominent,and gut microbiota in vaginal delivered babies are more uniformly distributed.