Silencing lncRNA NEAT1 reduces nonalcoholic fatty liver fat deposition by regulating the miR-139-5p/c-Jun/SREBP-1c pathway.

INTRODUCTION AND OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) starts with the abnormal accumulation of lipids in the liver. Long noncoding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) was reported to modulate hepatic metabolic homeostasis in NAFLD. However, little is known about the molecular mechanisms of NAFLD. MATERIALS AND METHODS: To establish a NAFLD cellular model, HepG2 cells and LO2 cells were treated with 1 mM free fatty acids (FFAs) for 24 h. NEAT1, miRNA (miR)-139-5p, c-Jun and sterol-regulatory element binding protein-1c (SREBP-1c) were evaluated using qPCR. The protein levels of c-Jun, SREBP1c, acetyl-CoA carboxylase (ACC) and fatty acid synthetase (FAS) were determined using western blotting. Moreover, Oil Red O staining was employed to assess lipid accumulation. In addition, a kit assay was performed to evaluate TG levels. Finally, the interactions among NEAT1, miR-139-5p, c-Jun and SREBP1c were identified by dual luciferase reporter gene assay. RESULTS: NEAT1, c-Jun and SREBP1c expression was markedly elevated, while miR-139-5p expression was reduced in the NAFLD cellular model. NEAT1 knockdown restrained lipid accumulation in the NAFLD cellular model by directly targeting miR-139-5p. Moreover, miR-139-5p overexpression suppressed lipid accumulation by directly suppressing c-Jun expression. In addition, c-Jun silencing suppressed lipid accumulation by directly targeting SREBP1c. Finally, miR-139-5p inhibition mitigated the inhibitory effect of sh-NEAT1 on lipid accumulation. CONCLUSION: NEAT1 aggravated FFA-induced lipid accumulation in hepatocytes by regulating the c-Jun/SREBP1c axis by sponging miR-139-5p, indicating the potential of NEAT1 as a promising therapeutic target for NAFLD.

Complementary feeding and childhood adiposity in preschool-aged children in a large Chinese cohort.

OBJECTIVE: To examine the association between the timing and type of complementary feeding and childhood adiposity in Mainland China. STUDY DESIGN: During 1999-2009, 97 424 singletons were enrolled in the Jiaxing Birth Cohort, a population-based prospective cohort study in Southeast China. Of these children, 43 848 children provided complementary diet information and other anthropometric measurements at 1, 3, and 6 months of age and were followed up until 4-5 years of age. Obesity and overweight were identified as body mass index (BMI)-for-age z-score (SD) ≥2 and between 1 and 2, respectively. RESULTS: Among 40 510 children in the statistical analysis, 3.18% were overweight and 64.8% were fed complementary food before 3 months of age. Early introduction of complementary foods was associated with greater BMI z-score (P-trend < .001) and higher risk of overweight (P-trend = .033). Compared with introduction of complementary foods between 4-6 months of age, before 3 months of age of introduction was associated with 11% greater risk of overweight (OR 1.11, 95% CI 1.03-1.19). No significant association between timing of complementary feeding and obesity was observed. Fish liver oil was the major type of complementary food associated with adiposity. Early introduction of fish liver oil was associated with greater BMI z-score (P < .001) and greater risk of overweight (P-trend = .004). CONCLUSIONS: Early introduction of fish liver oil is associated with greater childhood BMI and risk of overweight in Chinese children at 4-5 years of age.

Circulating 25-hydroxyvitamin D, IRS1 variant rs2943641, and insulin resistance: replication of a gene-nutrient interaction in 4 populations of different ancestries.

BACKGROUND: Associations of either insulin receptor substrate 1 (IRS1) variants or circulating 25-hydroxyvitamin D [25(OH)D] with type 2 diabetes (T2D) and insulin resistance (IR) are inconsistent. This study sought to determine whether circulating 25(OH)D modulates the association of a potentially functional variant at IRS1 (rs2943641) with insulin resistance. METHOD: Interaction between IRS1 rs2943641 and circulating 25(OH)D on homeostasis model assessment for IR (HOMA-IR) was examined in the Boston Puerto Rican Health Study (BPRHS) (n = 1144). Replication was performed in the African-American (n = 1126), non-Hispanic white (n = 1967), and Hispanic (n = 1241) populations of the Multi-Ethnic Study of Atherosclerosis (MESA) with genotypes of 3 IRS1 variants, rs2972144, rs1515104, and rs2673142, which are tag single nucleotide polymorphisms (SNPs) and in strong linkage disequilibrium with rs2943641. RESULTS: Higher circulating 25(OH)D was associated with lower risk of T2D and IR in BPRHS women homozygous for minor allele rs2943641T. Consistently, in each of 3 MESA populations, HOMA-IR and insulin decreased more evidently with higher circulating 25(OH)D in women of the rs2943641TT genotype than in carriers of the major allele (rs2943641C). Metaanalysis indicated significant and consistent interactions between circulating 25(OH)D and IRS1 variants on HOMA-IR (log transformed) [pooled ß = -0.008, 95% CI: -0.016 to -0.001, P interaction = 0.004] and insulin (log transformed) (pooled ß = -0.006, 95% CI: -0.011 to -0.002, P interaction = 0.023) in 3065 women of the 4 populations. CONCLUSIONS: Participants with different genotypes of IRS1 rs2943641 exhibit differential benefit from high circulating 25(OH)D for the reduction of insulin resistance and T2D risk. This gene-nutrient interaction, which appears to be limited to women, warrants further examination in randomized controlled trials of vitamin D supplementation.