Comparison of long non-coding RNAs in adipose and muscle tissues between seven indigenous Chinese and the Yorkshire pig breeds

lncRNAs play crucial roles in fat metabolism in animals. Previously, we have compared the mRNA transcriptome profiles between seven fat-type Chinese pig breeds and one lean-type Western breed (Yorkshire, YY). The associations between differentially expressed (DE) genes and phenotypical traits were investigated. In the present study, to further explore the underlying regulatory mechanisms, lncRNAs were sequenced and compared between YY and Chinese indigenous breeds. The results showed 9114 and 7538 DE lncRNAs between at least one Chinese breed and the YY breed in the adipose and muscle tissue respectively. KEGG enrichment analysis revealed that the target genes of these DE lncRNAs mainly influenced the glucolipid metabolism, which is an important process affecting meat quality. Correlation analyses between the DE lncRNA and DE mRNA genes related to meat quality and growth traits were performed. The results showed that LTCONS_00073280 was associated with intramuscular fat content. Four lncRNAs (LTCONS_00101781, LTCONS_00037879, LTCONS_00088260 and LTCONS-00128343) might mediate backfat thickness. Overall, this study provides candidate lncRNAs that potentially affect meat quality, which might be useful for molecular breeding of pig breeds in future.

Developmental changes in the expression of the GLUT2 and GLUT4 genes in the longissimus dorsi muscle of Yorkshire and Tibetan pigs

Glucose transporter proteins 2 and 4 (GLUT2 and GLUT4) play important roles in glucose transport and energy metabolism. Changes in the levels of GLUT2 and GLUT4 mRNA were measured in longissimus dorsi muscle from the lean Yorkshire and fat Tibetan pig breeds at six different time points (1, 2, 3, 4, 5, and 6 months) with quantitative real-time polymerase chain reactions. The results showed that GLUT2 and GLUT4 mRNA were abundantly expressed in the longissimus dorsi muscle and that the developmental expression patterns were similar in both breeds. Tibetan pigs exhibited higher intramuscular fat and GLUT2 mRNA levels, while Yorkshire pigs exhibited a higher myofiber cross-sectional area (CSA) and GLUT4 mRNA levels. Furthermore, the changes in the GLUT4 mRNA levels were strongly and positively correlated with the CSA over a period of six months. These results exhibit time- and breed-specific expression patterns of GLUT2 and GLUT4, which highlight their potential as candidate genes for assessing adipose deposition and muscle development in pigs. These differences in the expression of GLUT family genes may also have indications for meat quality.

Serum secretory phospholipase A2-IIa (sPLA2-IIA) levels in patients surviving acute myocardial infarction

BACKGROUND

The increase of secretory phospholipase A2-IIa (sPLA2-IIa) in culprit coronary lesions is associated with myocardial infarction, and the increase of sPLA2-IIa in peripheral plasma levels has a significant risk and prognostic value in patients with coronary artery disease. Little is known about the prognostic significance of elevated serum sPLA2-IIa in post-acute myocardial infarction (post-AMI) patients.

OBJECTIVES

The present study is designed to investigate the potential association between serum sPLA2-IIa and prognosis in post-acute myocardial infarction (post-AMI) patients.

PATIENTS AND METHODS

From Oct 1998 to Sep 2008, a total of 964 post-AMI patients with serum samples collected in the convalescent stage were studied. Serum levels of sPLA2-IIa were measured by ELISA. According to the optimal cut-off value for sPLA2-IIa concentration, patients were then divided into 2 groups. Categorical variables were compared between the 2 groups using the χ2 test. All continuous variables are described as mean ± SD and were compared using Student's t-test. Statistical associations between clinicopathological observations and sPLA2-IIa levels were determined using the Mann-Whitney U test. The clinical value of sPLA2-IIa level as a prognostic parameter was evaluated using the Cox's proportional hazards model.

RESULTS

During a median follow-up period of 1,462 days, 123 patients (12.7%) had adverse events (all-cause mortality, n=52; non-fatal MI, n=31; readmission for heart failure [HF], n=40). Patients were divided into 2 groups according to a serum sPLA2-IIa level of 360 ng/dl, which was determined to be the optimal cut-off for discriminating all-cause mortality based on the maximum value of the area under the receiver operating characteristic curve. Patients with elevated sPLA2-IIa (> 360 ng/dl, n=164) had a significantly higher prevalence of death (18.3% [30/164] vs. 2.75% [22/800] p < 0.001) and readmission for HF (14% [23/164/ vs. 2.1% [17/800], p < 0.0001), but not of non-fatal MI (4.88% [8/164]vs. 2.87% [23/800], p = 0.096), compared to those with sPLA2-IIa < 360 ng/dl. Multivariate Cox regression analysis indicated that elevated serum sPLA2-IIa was associated with an increased risk of mortality and readmission for HF.

CONCLUSIONS

Elevated serum sPLA2-IIa during the convalescent stage of AMI predicted long-term mortality and readmission for HF after survival discharge in the post-AMI patients.