RESUMO
【Objective】 To evaluate the differential miRNA expression of breast milk exosome in premature and full-term groups, and to analyze the regulatory pathways by bioinformatics, so as to provide guidance and scientific basis for the growth and development of premature infants and the prevention and treatment of related diseases. 【Methods】 From August 2020 to June 2021, breast milk samples from 13 premature (premate group) and 9 full-term infants(full-term group) in the Department of Child Health Care of the Second Affiliated Hospital of Nanjing Medical University were collected to extract exosomes. The miRNAs of two groups of breast milk exosomes were sequenced by high-throughput sequencing. According to the sequencing results, miRNA expression profiles of milk exosome were analyzed. Biological function software was used to carry out GO and KEGG pathway analysis of differential miRNA. 【Results】 The expression of miRNA in human milk exosomes was rich, especially hsa-miR-148a-3p,hsa-let-7b-5p, hsa-let-7g-5p, hsa-miR-22-3p, hsa-miR-99a-5p, hsa-miR-200, hsa-miR-146b-5p and hsa-miR-26a-5p were relatively high expressed in preterm group and full-term group. Differential expression analysis showed that compared with full-term infant breast milk, 7 miRNAs were up-regulated(log2|fold change|=2.803, 2.714, 1.632, 2.360, 1.350, 3.387, 2.137, respectively), and 5 miRNAs were down-regulated(log2|fold change|=-2.553, -2.197, -2.771, -1.395, -1.136, respectively)(|fold change>2|, P<0.05) in breast milk for preterm infants. In these differential expressed miRNAs, down-regulated miR-29b(P=0.001) and up-regulated miR-133a-3p(P=0.004) were associated with inflammation, and up-regulated miR-126-5p(P=0.021) and miR-126-3p(P=0.041) were associated with lipid metabolism. The fatty acid biosynthesis pathway was obviously enriched in preterm group. MiR-7-5p, miR-29b-3p and miR-100-5p played a role in the fatty acid synthesis pathway. 【Conclusions】 Exosomal miRNAs are rich in breast milk, and have significant differences between preterm and full-term infants′ mothers. The differentially expressed miRNA in preterm infants treast milk may be related to inflammation and promote the growth and development of preterm infants through the fatty acid biosynthesis pathway.
RESUMO
Objective:To explore the effect and mechanism of omega 3-polyunsaturated fatty acid(ω3-PUFA) dietary intervention on mitochondrial function of white adipose tissue in adult rats with postnatal early overfeeding.Methods:An overfed animal model by adjusting litter size was developed for the study of neonatal overfeeding. The litter size was adjusted to 3 male rats per litter(small litter, SL group) and 10 pups per litter(normal litter, NL group). After weaning(week 3), the pups were fed standard chow or ω3-PUFA diet(SL-FO) until postnatal weeks 13. Food intake, body weight, and rectal temperature of rats were measured regularly, and energy metabolism of animals was monitored in week 13. During week 3 and 13, subcutaneous adipose tissue was collected. Inguinal preadipocytes of mice were isolated and induced to differentiate, and 50 μmol/L eicosapentaenoicacid(EPA) was administered for 48 h at the late stage of differentiation. The mRNA and protein expression levels of mitochondrial related genes, mitochondrial copy number, and oxygen consumption rate of adipocytes were detected in adipose tissue and adipocytes.Results:By the 3rd week, the body weight, food intake, and fat cell area in SL group were higher than those in NL group while the body temperature was lower until to 13 weeks. By the 13th week, the O 2 consumption, CO 2 output, and heat production of rats in SL group were lower than those in NL group. Meanwhile, the expressions of mitochondrial function related genes such as uncoupling protein 1(UCP1), carnitine palmitoyltransferase 1(CPT1), SIRT1, and mitochondrial biosynthesis regulatory gene peroxisome proliferator-activated receptor coativator-1 (PGC1α) in adipose tissue by the 3rd and 13th week were significantly reduced( P<0.05). After weaning, ω3-PUFA diet significantly reduced weight gain in SL rats, increased UCP1 protein expression, restored energy metabolism level and mitochondrial function related gene expression. In vitro intervention of EPA increased the mitochondrial copy number, the mRNA and protein expression levels of mitochondrial biosynthesis and functional genes, as well as the mitochondrial basic oxygen consumption rate( P<0.05). Conclusion:ω3-PUFA improves postnatal overfeeding-induced impairment of the mitochondrial function and biosynthesis of subcutaneous white adipose tissue in rats, which may be an important mechanism for fish oil diet to inhibit the early over-nutrition program and restore the thermogenic metabolism.
RESUMO
Objective@#To explore the effect and mechanism of omega 3-polyunsaturated fatty acid(ω3-PUFA) dietary intervention on mitochondrial function of white adipose tissue in adult rats with postnatal early overfeeding.@*Methods@#An overfed animal model by adjusting litter size was developed for the study of neonatal overfeeding. The litter size was adjusted to 3 male rats per litter(small litter, SL group) and 10 pups per litter(normal litter, NL group). After weaning(week 3), the pups were fed standard chow or ω3-PUFA diet(SL-FO) until postnatal weeks 13. Food intake, body weight, and rectal temperature of rats were measured regularly, and energy metabolism of animals was monitored in week 13. During week 3 and 13, subcutaneous adipose tissue was collected. Inguinal preadipocytes of mice were isolated and induced to differentiate, and 50 μmol/L eicosapentaenoicacid(EPA) was administered for 48 h at the late stage of differentiation. The mRNA and protein expression levels of mitochondrial related genes, mitochondrial copy number, and oxygen consumption rate of adipocytes were detected in adipose tissue and adipocytes.@*Results@#By the 3rd week, the body weight, food intake, and fat cell area in SL group were higher than those in NL group while the body temperature was lower until to 13 weeks. By the 13th week, the O2 consumption, CO2 output, and heat production of rats in SL group were lower than those in NL group. Meanwhile, the expressions of mitochondrial function related genes such as uncoupling protein 1(UCP1), carnitine palmitoyltransferase 1(CPT1), SIRT1, and mitochondrial biosynthesis regulatory gene peroxisome proliferator-activated receptor coativator-1 (PGC1α) in adipose tissue by the 3rd and 13th week were significantly reduced(P<0.05). After weaning, ω3-PUFA diet significantly reduced weight gain in SL rats, increased UCP1 protein expression, restored energy metabolism level and mitochondrial function related gene expression. In vitro intervention of EPA increased the mitochondrial copy number, the mRNA and protein expression levels of mitochondrial biosynthesis and functional genes, as well as the mitochondrial basic oxygen consumption rate(P<0.05).@*Conclusion@#ω3-PUFA improves postnatal overfeeding-induced impairment of the mitochondrial function and biosynthesis of subcutaneous white adipose tissue in rats, which may be an important mechanism for fish oil diet to inhibit the early over-nutrition program and restore the thermogenic metabolism.