Danlou Tablet Improves Chronic Intermittent Hypoxia-Induced Dyslipidemia and Arteriosclerosis by HIF-1α-Angptl4 mRNA Signaling Pathway.

OBJECTIVE: To detect whether Danlou Tablet (DLT) regulates the hypoxia-induced factor (HIF)-1α-angiopoietin-like 4 (Angptl4) mRNA signaling pathway and explore the role of DLT in treating chronic intermittent hypoxia (CIH)-induced dyslipidemia and arteriosclerosis. METHODS: The mature adipocytes were obtained from 3T3-L1 cell culturation and allocated into 8 groups including control groups (Groups 1 and 5, 0.1 mL of cell culture grade water); DLT groups (Groups 2 and 6, 0.1 mL of 1,000 µg/mL DLT submicron powder solution); dimethyloxalylglycine (DMOG) groups (Groups 3 and 7, DMOG and 0.1 mL of cell culture grade water); DMOG plus DLT groups (Groups 4 and 8, DMOG and 0.1 mL of 1,000 µg/mL DLT submicron powder solution). Groups 1-4 used mature adipocytes and groups 5-8 used HIF-1 α-siRNA lentivirus-transfected mature adipocytes. After 24-h treatment, real-time polymerase chain reaction and Western blot were employed to determine the mRNA and protein expression levels of HIF-1 α and Angptl4. In animal experiments, the CIH model in ApoE-/- mice was established. Sixteen mice were complete randomly divided into 4 groups including sham group, CIH model group [intermittent hypoxia and normal saline (2 mL/time) gavage once a day]; Angptl4 Ab group [intermittent hypoxia and Angptl4 antibody (30 mg/kg) intraperitoneally injected every week]; DLT group [intermittent hypoxia and DLT (250 mg/kg) once a day], 4 mice in each group. After 4-week treatment, enzyme linked immunosorbent assay was used to detect the expression levels of serum total cholesterol (TC) and triglyceride (TG). Hematoxylin-eosin and CD68 staining were used to observe the morphological properties of arterial plaques. RESULTS: Angptl4 expression was dependent on HIF-1 α, with a reduction in mRNA expression and no response in protein level to DMOG or DLT treatment in relation to siHIF-1 α -transfected cells. DLT inhibited HIF-1 α and Angptl4 mRNA expression (P<0.05 or P<0.01) and reduced HIF-1 α and Angptl4 protein expressions with DMOG in mature adipocytes (all P<0.01), as the effect on HIF-1 α protein also existed in the presence of siHIF-1 α (P<0.01). ApoE-/- mice treated with CIH had increased TG and TC levels (all P<0.01) and atherosclerotic plaque. Angptl4 antibody and DLT both reduce TG and TC levels (all P<0.01), as well as reducing atherosclerotic plaque areas, narrowing arterial wall thickness and alleviating atherosclerotic lesion symptoms to some extent. CONCLUSION: DLT had positive effects in improving dyslipidemia and arteriosclerosis by inhibiting Angptl4 protein level through HIF-1 α-Angptl4 mRNA signaling pathway.

Genome-wide study refines the quantitative trait locus for number of ribs in a Large White × Minzhu intercross pig population and reveals a new candidate gene.

In China, sparerib is one of the most valuable parts of the pork carcass. As a result, candidate gene mining for number of ribs has become an interesting study focus. To examine the genetic basis for this major trait, we genotyped 596 individuals from an F2 Large White × Minzhu intercross pig population using the PorcineSNP60 Genotyping BeadChip. The genome-wide association study identified a locus for number of ribs in a 2.38-Mb region on Sus scrofa chromosome 7 (SSC7 of Sus scrofa genome assembly, Sscrofa10.2). We identified the top significant SNP ASGA0035536, which explained 16.51 % of the phenotypic variance. A previously reported candidate causal mutation (g.19034 A>C) in vertebrae development-associated gene VRTN explained 8.79 % of the phenotypic variation on number of ribs and had a much lower effect than ASGA0035536. Haplotype sharing analysis in F1 boars localized the rib number QTL to a 951-kb interval on SSC7. This interval encompassed 17 annotated genes in Sscrofa10.2, including the previously reported VRTN candidate gene. Of the 17 candidate genes, LTBP2, which encodes a latent transforming growth factor beta binding protein, was previously reported to indirectly regulate the activity of growth differentiation factor Gdf11, which has been shown to increase the number of ribs in knock-out mice. Thus, we propose LTBP2 as a good new candidate gene for number of ribs in the pig population. This finding advances our understanding of the genetic architecture of rib number in pigs.

A genome-wide association study of limb bone length using a Large White × Minzhu intercross population.

BACKGROUND: In pig, limb bone length influences ham yield and body height to a great extent and has important economic implications for pig industry. In this study, an intercross population was constructed between the indigenous Chinese Minzhu pig breed and the western commercial Large White pig breed to examine the genetic basis for variation in limb bone length. The aim of this study was to detect potential genetic variants associated with porcine limb bone length. METHODS: A total of 571 F2 individuals from a Large White and Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip, and phenotyped for femur length (FL), humerus length (HL), hipbone length (HIPL), scapula length (SL), tibia length (TL), and ulna length (UL). A genome-wide association study was performed by applying the previously reported approach of genome-wide rapid association using mixed model and regression. Statistical significance of the associations was based on Bonferroni-corrected P-values. RESULTS: A total of 39 significant SNPs were mapped to a 11.93 Mb long region on pig chromosome 7 (SSC7). Linkage analysis of these significant SNPs revealed three haplotype blocks of 495 kb, 376 kb and 492 kb, respectively, in the 11.93 Mb region. Annotation based on the pig reference genome identified 15 genes that were located near or contained the significant SNPs in these linkage disequilibrium intervals. Conditioned analysis revealed that four SNPs, one on SSC2 and three on SSC4, showed significant associations with SL and HL, respectively. CONCLUSIONS: Analysis of the 15 annotated genes that were identified in these three haplotype blocks indicated that HMGA1 and PPARD, which are expressed in limbs and influence chondrocyte cell growth and differentiation, could be considered as relevant biological candidates for limb bone length in pig, with potential applications in breeding programs. Our results may also be useful for the study of the mechanisms that underlie human limb length and body height.