Transplantation of adipose tissue lacking PAI-1 improves glucose tolerance and attenuates cardiac metabolic abnormalities in high-fat diet-induced obesity

Systematic Review and Meta-Analysis of SERPINE1 4G/5G Insertion/Deletion Variant With Circulating Lipid Levels

Background

Recent studies have shown that the 4G/5G insertion/deletion variant of SERPINE1 (rs1799889) is closely linked to coronary artery disease (CAD). This study aims to clarify the effects of the rs1799889 variant on lipid levels and to insight into the mechanisms underlying the rs1799889 variant and CAD.

Methods and Results

By searching PubMed and the Cochrane databases for studies published before 31 October 2021, 40 studies conducted on a total of 13,117 subjects were included for the analysis. The consistent findings for the effects of the 5G allele of rs1799889 variant on lipid metabolism were the significantly decreased triglycerides (TG) [standardized mean difference (SMD) = –0.12, 95% CI = –0.21 to 0.03, P = 0.01], total cholesterol (TC) (SMD = –0.12, 95% CI = –0.17 to 0.06, P < 0.001), and low-density lipoprotein cholesterol (LDL-C) (SMD = –0.13, 95% CI = –0.23 to 0.03, P = 0.01) levels. Intriguingly, the significant effects of the rs1799889 variant on LDL-C (SMD = –0.15, 95% CI = –0.26 to 0.05, P < 0.01) and TC (SMD = –0.17, 95% CI = –0.27 to 0.07, P < 0.01) levels were primarily observed in the Asian population. However, the significant effect of the rs1799889 variant on high-density lipoprotein cholesterol (HDL-C) (SMD = 0.26, 95% CI = 0.03–0.48, P = 0.03) levels was detected only in female subjects.

Conclusion

The rs1799889 variant of SERPINE1 is a protective genetic factor against CAD, the Asian population with the 5G allele of the rs1799889 variant may have a reduced CAD risk.

Serpina3c regulates adipose differentiation via the Wnt/β-catenin-PPARγ pathway

OBJECTIVE

The Serpin protein family plays an important role in regulating the functioning of the adipose tissue. This study aimed to study the underlying mechanisms of Serpina3c in regulating adipogenesis.

METHODS

We developed a Serpina3c knockout (Serpina3c^-/-) mouse model and Serpina3c knockdown and overexpression 3 T3-L1 preadipocyte models to evaluate the role of Serpina3c in adipose differentiation. Mice were fed on ND for 12-month or HFD for one month. The body weight, glucose tolerance, and insulin tolerance of the mice were subsequently measured. Lipid depositions and adipose tissue morphology were then detected using Oil red O staining and HE staining. qRT-PCR and Western blot were used to detect the expression of adipose differentiation transcription factors.

RESULTS

Serpina3c^-/- mice exhibited lower body weight and white adipose tissue (WAT) weight than WT mice after 12 months of being fed on ND. Additionally, there was an increase in serum and hepatic triglyceride (TG) levels in Serpina3c^-/- mice, without changes in glucose metabolism. Wnt/β-catenin was upregulated while PPARγ expression was decreased in knockout mice WAT. Impaired adipocyte differentiation caused by Serpina3c knockdown was reversed by IWR-1 and kallistatin through an increase in PPARγ expression. Serpina3c^-/- mice fed on HFD for one month had a lower body weight and WAT than WT, accompanied by increased lipid depositions in the liver and muscles and severe insulin resistance.

CONCLUSION

Serpina3c promotes adipogenesis and maintains normal fat function by inhibiting the Wnt/β-catenin pathway.

Identification of candidate genes that specifically regulate subcutaneous and intramuscular fat deposition using transcriptomic and proteomic profiles in Dingyuan pigs

Subcutaneous fat and intramuscular fat (IMF) deposition are closely related to meat production and pork quality. Dingyuan pig, as a native pig breed in China, low selection leads to obvious genetic and phenotypic differences in the population. Individuals with extreme fat content in the population are ideal models for studying the mechanism of fat deposition. In this study, we used RNA-Seq and tandem mass tags-based (TMT) proteomics to analyze the key pathways and genes that specifically regulate subcutaneous fat and IMF deposition in Dingyuan pigs. We identified 191 differentially expressed genes (DEGs) and 61 differentially abundant proteins (DAPs) in the high and low back fat thickness (HBF, LBF) groups, 85 DEGs and 12 DAPs were obtained in the high and low intramuscular fat (HIMF, LIMF) groups. The functional analysis showed that the DEGs and DAPs in the backfat groups were mainly involved in carbohydrates, amino acids, and fatty acids metabolism, whereas the IMF groups were involved in the insulin pathway, longevity, and some disease-related pathways. We found 40 candidate genes that might tissue-specifically lipids deposition for subcutaneous and intramuscular fat. Our research provides theoretical reference materials for the improvement of fat deposition traits of local pig breeds in my country.

Role of adiposopathy and physical activity in cardio-metabolic disorder diseases

Positive calorie balance disrupts the function of visceral adipose tissue, including the cardiac adipose tissue and the perivascular adipose tissue. The inflammatory and hormonal factors, which are released from adipose tissue, play a central role in inter-organ cross talk, affecting the development of obesity. Excess fat in visceral adipocytes impairs endocrine as well as immune response, leading to multiple aberrant status and posing serious risks to the future health of humans. As confirmed in previous studies, up-regulated pro-inflammatory and down-regulated anti-inflammatory cytokines disturb the communication among muscle, liver, and vasculature. In other words, adiposopathy promote cardio-metabolic risk factors, such as atherosclerosis, hypertension, insulin resistance, dyslipidemia, and pro-thrombotic state, which in turn directly and indirectly promote cardio-metabolic disorder diseases. Increasing evidence from human and animal studies has shown that physical activity restores the size of adipocytes and helps in re-browning of white adipose tissue (WAT). This review summarizes the current evidence on the roles of adiposopathy on cardio-metabolic disorder diseases and the importance of physical activity in restoring the function of adipocytes.

Is Neck Circumference As Reliable As Waist Circumference for Determining Metabolic Syndrome?

Background: Metabolic syndrome (MS) comprises a cluster of risk factors for the development of cardiovascular diseases, which are among the leading causes of morbidity and mortality worldwide. Many studies have shown that neck circumference (NC) has validity in the measure of MS since it correlates positively with the traditional components. For these reasons, this study aimed at comparing waist circumference (WC) and NC for identifying MS parameters in patients treated at a cardiology unit. Methods: This study included 309 patients assisted in a Cardiology Unit. Biochemical and anthropometric parameters were evaluated. Correlations between neck and WC with anthropometric, biochemical, and atherogenic indices were evaluated. The diagnostic ability of neck and WC was assessed by using the receiver operating characteristics curve. Results: The patients had a mean age of 57.2 years, and 56% were men. The diagnosis of MS was present in 48% of men and 39% of women. Neck and WC showed a positive correlation with each other, and both showed positive correlations with the criteria for MS. Moreover, NC showed a positive correlation with body mass index (BMI), insulin, homeostatic model assessment (HOMA)-β, and C-reactive protein. WC showed a positive correlation with BMI, HOMA of insulin resistance (HOMA-IR), and Castelli Index I. Both neck and WC showed the ability to identify the presence of the MS. Conclusion: Both neck and WC showed a significant correlation with several of the metabolic parameters, including some used as criteria for the diagnosis of MS. In addition, both measures demonstrated a good ability to predict MS, making these measures promising for screening patients with this syndrome.