Inflammatory Macrophage Interleukin-1β Mediates High-Fat Diet-Induced Heart Failure With Preserved Ejection Fraction

Diabetes mellitus (DM) is a main risk factor for diastolic dysfunction (DD) and heart failure with preserved ejection fraction. High-fat diet (HFD) mice presented with diabetes mellitus, DD, higher cardiac interleukin (IL)-1β levels, and proinflammatory cardiac macrophage accumulation. DD was significantly ameliorated by suppressing IL-1β signaling or depleting macrophages. Mice with macrophages unable to adopt a proinflammatory phenotype were low in cardiac IL-1β levels and were resistant to HFD-induced DD. IL-1β enhanced mitochondrial reactive oxygen species (mitoROS) in cardiomyocytes, and scavenging mitoROS improved HFD-induced DD. In conclusion, macrophage-mediated inflammation contributed to HFD-associated DD through IL-1β and mitoROS production.

Effect of Korean Red Ginseng on metabolic syndrome

Metabolic syndrome (MS) refers to a clustering of at least three of the following medical conditions: high blood pressure, abdominal obesity, hyperglycemia, low high-density lipoprotein level, and high serum triglycerides. MS is related to a wide range of diseases which includes obesity, diabetes, insulin resistance, cardiovascular disease, dyslipidemia, or non-alcoholic fatty liver disease. There remains an ongoing need for improved treatment strategies for MS. The most important risk factors are dietary pattern, genetics, old age, lack of exercise, disrupted biology, medication usage, and excessive alcohol consumption, but pathophysiology of MS has not been completely identified. Korean Red Ginseng (KRG) refers to steamed/dried ginseng, traditionally associated with beneficial effects such as anti-inflammation, anti-fatigue, anti-obesity, anti-oxidant, and anti-cancer effects. KRG has been often used in traditional medicine to treat multiple metabolic conditions. This paper summarizes the effects of KRG in MS and related diseases such as obesity, cardiovascular disease, insulin resistance, diabetes, dyslipidemia, or non-alcoholic fatty liver disease based on experimental research and clinical studies.

Quercetin inhibits adipogenesis of muscle progenitor cells in vitro

Muscle satellite cells are committed myogenic progenitors capable of contributing to myogenesis to maintain adult muscle mass and function. Several experiments have demonstrated that muscle satellite cells can differentiate into adipocytes in vitro, supporting the mesenchymal differentiation potential of these cells. Moreover, muscle satellite cells may be a source of ectopic muscle adipocytes, explaining the lipid accumulation often observed in aged skeletal muscle (sarcopenia) and in muscles of patients` with diabetes. Quercetin, a polyphenol, is one of the most abundant flavonoids distributed in edible plants, such as onions and apples, and possesses antioxidant, anticancer, and anti-inflammatory properties. In this study, we examined whether quercetin inhibited the adipogenesis of muscle satellite cells in vitro with primary cells from rat limbs by culture in the presence of quercetin under adipogenic conditions. Morphological observations, Oil Red-O staining results, triglyceride content analysis, and quantitative reverse transcription polymerase chain reaction revealed that quercetin was capable of inhibiting the adipogenic induction of muscle satellite cells into adipocytes in a dose-dependent manner by suppressing the transcript levels of adipogenic markers, such as peroxisome proliferator-activated receptor-γ and fatty acid binding protein 4. Our results suggested that quercetin inhibited the adipogenesis of muscle satellite cells in vitro by suppressing the transcription of adipogenic markers.

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Quercetin inhibited the adipogenesis of muscle satellite cells in vitro.

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The effect of quercetin might be based on suppression at the transcriptional levels.

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Quercetin could limit ectopic lipid accumulation as observed in aged muscles.

Conserved function of the long noncoding RNA Blnc1 in brown adipocyte differentiation

OBJECTIVE

Long noncoding RNAs (lncRNAs) are emerging as important regulators of diverse biological processes. Recent work has demonstrated that the inducible lncRNA Blnc1 stimulates thermogenic gene expression during brown and beige adipocyte differentiation. However, whether Blnc1 is functionally conserved in humans has not been explored. In addition, the molecular basis of the Blnc1 ribonucleoprotein complex in thermogenic gene induction remains incompletely understood. The aims of the current study were to: i) investigate functional conservation of Blnc1 in mice and humans and ii) elucidate the molecular mechanisms by which Blnc1 controls the thermogenic gene program in brown adipocytes.

METHODS

Full-length human Blnc1 was cloned and examined for its ability to stimulate brown adipocyte differentiation. Different truncation mutants of Blnc1 were generated to identify functional RNA domains responsible for thermogenic gene induction. RNA-protein interaction studies were performed to delineate the molecular features of the Blnc1 ribonucleoprotein complex.

RESULTS

Blnc1 is highly conserved in mice and humans at the sequence and function levels, both capable of stimulating brown adipocyte gene expression. A conserved RNA domain was identified to be required and sufficient for the biological activity of Blnc1. We identified hnRNPU as an RNA-binding protein that facilitates the assembly and augments the transcriptional function of the Blnc1/EBF2 ribonucleoprotein complex.

CONCLUSIONS

Blnc1 is a conserved lncRNA that promotes thermogenic gene expression in brown adipocytes through formation of the Blnc1/hnRNPU/EBF2 ribonucleoprotein complex.

Improved adipose tissue metabolism after 5-year growth hormone replacement therapy in growth hormone deficient adults: The role of zinc-α2-glycoprotein

Growth hormone (GH) supplementation therapy to adults with GH deficiency has beneficial effects on adipose tissue lipid metabolism, improving thus adipocyte functional morphology and insulin sensitivity. However, molecular nature of these effects remains unclear. We therefore tested the hypothesis that lipid-mobilizing adipokine zinc-α2-glycoprotein is causally linked to GH effects on adipose tissue lipid metabolism. Seventeen patients with severe GH deficiency examined before and after the 5-year GH replacement therapy were compared with age-, gender- and BMI-matched healthy controls. Euglycemic hyperinsulinemic clamp was used to assess whole-body and adipose tissue-specific insulin sensitivity. Glucose tolerance was determined by oGTT, visceral and subcutaneous abdominal adiposity by MRI, adipocyte size morphometrically after collagenase digestion, lipid accumulation and release was studied in differentiated human primary adipocytes in association with GH treatment and zinc-α2-glycoprotein gene silencing. Five-year GH replacement therapy improved glucose tolerance, adipose tissue insulin sensitivity and reduced adipocyte size without affecting adiposity and whole-body insulin sensitivity. Adipose tissue zinc-α2-glycoprotein expression was positively associated with whole-body and adipose tissue insulin sensitivity and negatively with adipocyte size. GH treatment to adipocytes in vitro increased zinc-α2-glycoprotein expression (>50%) and was paralleled by enhanced lipolysis and decreased triglyceride accumulation (>35%). Moreover, GH treatment improved antilipolytic action of insulin in cultured adipocytes. Most importantly, silencing zinc-α2-glycoprotein eliminated all of the GH effects on adipocyte lipid metabolism. Effects of 5-year GH supplementation therapy on adipose tissue lipid metabolism and insulin sensitivity are associated with zinc-α2-glycoprotein. Presence of this adipokine is required for the GH action on adipocyte lipid metabolism in vitro.