a-surgical-model-for-graft-brown-adipose-tissue-on-heart-surface

A Surgical Model for Graft of Brown Adipose Tissue on the Heart Surface in Mice

A mouse model for investigating the paracrine effects of browning epicardial adipose tissue (EAT) on coronary arteries and the myocardium should be ...

The Second Xiangya Hospital of Central South University

 Dendrobium officinale polysaccharide (DOP) is the main active ingredient in a valuable traditional Chinese medicine, which exerts several pharmacological activities including hepatoprotection and hypoglycemic effects. However, the effects of DOP on obesity-associated insulin resistance (IR) and lipid metabolism remain unknown. This study aimed to investigate the role of DOP in IR and abnormal lipid metabolism in obese mice.  IR models were established using 3T3-L1 adipocytes, C2C12 myocytes, and primary cultured hepatocytes exposed to palmitate acid. After treatment with DOP, insulin-stimulated glucose uptake, glucose release, and AKT phosphorylation was detected. Fasting blood glucose, fasting serum insulin, the glucose tolerance test (GTT), and the insulin tolerance test (ITT) were measured to evaluate IR of obese mice. Lipid analysis was conducted to evaluate the effects of DOP on lipid metabolism in obese mice.  , DOP treatment ameliorated palmitic acid-induced IR in adipocytes, myocytes, and hepatocytes. DOP regulated cellular insulin sensitivity  the peroxisome proliferator-activated receptor-γ (PPAR-γ). Furthermore, administration of DOP significantly reduced the IR and visceral adipose tissue (VAT) inflammation of diet-induced obese (DIO) and the genetically-induced obesity mice (ob/ob) mouse models. In addition, DOP treatment attenuated the high-fat diet (HFD)-induced liver lipid accumulation by reducing liver triglycerides (TG), plasma free fatty acid (FFA), serum cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels, while increasing HDL-C levels.  DOP could improve obesity-associated IR and abnormal lipid metabolism through its activities on PPAR-γ, and may serve as a potential therapeutic agent for obesity-associated insulin resistance and lipid metabolism disorder.

Dendrobium Officinale Polysaccharide Attenuates Insulin Resistance and Abnormal Lipid Metabolism in Obese Mice.

Vascular calcification and vascular ageing are "silent" diseases but are highly prevalent in patients with end stage renal failure and type 2 diabetes, as well as in the ageing population. Melatonin (MT) has been shown to induce cardiovascular protection effects. However, the role of MT on vascular calcification and ageing has not been well-identified. In this study, the aortic transcriptional landscape revealed clues for MT related cell-to-cell communication between endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) in vascular calcification and vascular ageing. Furthermore, we elucidated that it was exosomes that participate in the information transportation from ECs to VSMCs. The exosomes secreted from melatonin-treated ECs (MT-ECs-Exos) inhibited calcification and senescence of VSMCs. Mechanistically, miR-302d-5p was highly enriched in MT-ECs-Exos, while depletion of miR-302d-5p blocked the ability of MT-ECs-Exos to suppress VSMC calcification and senescence. Notably, Wnt3 was a bona fide target of miR-302d-5p and modulated VSMC calcification and senescence. Furthermore, we found that maturation of endothelial derived exosomal miR-302d-5p was promoted by WTAP in an N-methyladenosine (mA)-dependent manner. Interestingly, MT alleviated vascular calcification and ageing in 5/6-nephrectomy (5/6 NTP) mice, a chronic kidney disease (CKD) induced vascular calcification and vascular ageing mouse model. MT-ECs-Exos was absorbed by VSMCs in vivo and effectively prevented vascular calcification and ageing in 5/6 NTP mice. ECs-derived miR-302d-5p mediated MT induced anti-calcification and anti-ageing effects in 5/6 NTP mice. Our study suggests that MT-ECs-Exos alleviate vascular calcification and ageing through the miR-302d-5p/Wnt3 signaling pathway, dependent on mA methylation.

Vascular wall microenvironment: Endothelial cells original exosomes mediated melatonin-suppressed vascular calcification and vascular ageing in a m6A methylation dependent manner.

Article	Year
Dendrobium Officinale Polysaccharide Attenuates Insulin Resistance and Abnormal Lipid Metabolism in Obese Mice. Frontiers in pharmacology\| PubMed ID: 34194325	2021
Vascular wall microenvironment: Endothelial cells original exosomes mediated melatonin-suppressed vascular calcification and vascular ageing in a m6A methylation dependent manner. Bioactive materials\| PubMed ID: 39280584	2024

Zhi-Ang Zhou

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