miR-143-Mediated Responses to Betaine Supplement Repress Lipogenesis and Hepatic Gluconeogenesis by Targeting MAT1a and MAPK11

Dietary Betaine Attenuates High-Carbohydrate-Diet-Induced Oxidative Stress, Endoplasmic Reticulum Stress, and Apoptosis in Mandarin Fish (Siniperca chuatsi)

To investigate the impact of betaine on high-carbohydrate-diet-induced oxidative stress and endoplasmic reticulum (ER) stress, mandarin fish (Siniperca chuatsi) (23.73 ± 0.05 g) were fed with control (NC), betaine (BET), high carbohydrate (HC), and high carbohydrate + betaine (HC + BET) diets for 8 weeks. The results showed that betaine significantly promoted the growth of mandarin fish irrespective of the dietary carbohydrate levels. The HC diet induced oxidative stress, as evidenced by significantly elevated MDA levels. The HC diet significantly stimulated the mRNA levels of genes involved in ER stress (ire1, perk, atf6, xbp1, eif2α, atf4, chop), autophagy (ulk1, becn1, lc3b), and apoptosis (bax). However, betaine mitigated HC-diet-induced oxidative stress by modulating antioxidant enzymes and alleviated ER stress by regulating the mRNA of genes in the PERK-eIF2a-ATF4 pathway. Additionally, betaine significantly reduced the mRNA levels of becn1 and bax, along with the apoptosis rate, indicating a mitigating effect on autophagy and apoptosis. Overall, dietary betaine improved growth, attenuated HC-diet-induced oxidative stress and ER stress, and ultimately alleviated apoptosis in mandarin fish. These findings provide evidence for the use of betaine in aquafeeds to counter disruptive effects due to diets containing high carbohydrate levels.

MiR-143 Targets SYK to Regulate NEFA Uptake and Contribute to Thermogenesis in Male Mice

Excessive energy intake is the main cause of obesity, and stimulation of brown adipose tissue (BAT) and white adipose tissue (WAT) thermogenesis has emerged as an attractive tool for antiobesity. Although miR-143 has been reported to be associated with BAT thermogenesis, its role remains unclear. Here, we found that miR-143 had highest expression in adipose tissue, especially in BAT. During short-term cold exposure or CL316,243 was injected, miR-143 was markedly downregulated in BAT and subcutaneous WAT (scWAT). Moreover, knockout (KO) of miR-143 increases the body temperature of mice upon cold exposure, which may be due to the increased thermogenesis of BAT and scWAT. More importantly, supplementation of miR-143 in BAT of KO mice can inhibit the increase in body temperature in KO mice. Mechanistically, spleen tyrosine kinase was revealed for the first time as a new target of miR-143, and deletion of miR-143 facilitates fatty acid uptake in BAT. In addition, we found that brown adipocytes can promote fat mobilization of white adipocytes, and miR-143 may participate in this process. Meanwhile, we demonstrate that inactivation of adenylate cyclase 9 (AC9) in BAT inhibits thermogenesis through AC9-PKA-AMPK-CREB-UCP1 signaling pathway. Overall, our results reveal a novel function of miR-143 on thermogenesis, and a new functional link of the BAT and WAT.

Insight into the Inter-Organ Crosstalk and Prognostic Role of Liver-Derived MicroRNAs in Metabolic Disease Progression

Dysfunctional hepatic metabolism has been linked to numerous diseases, including non-alcoholic fatty liver disease, the most common chronic liver disorder worldwide, which can progress to hepatic fibrosis, and is closely associated with insulin resistance and cardiovascular diseases. In addition, the liver secretes a wide array of metabolites, biomolecules, and microRNAs (miRNAs) and many of these secreted factors exert significant effects on metabolic processes both in the liver and in peripheral tissues. In this review, we summarize the involvement of liver-derived miRNAs in biological processes with an emphasis on delineating the communication between the liver and other tissues associated with metabolic disease progression. Furthermore, the review identifies the primary molecular targets by which miRNAs act. These consolidated findings from numerous studies provide insight into the underlying mechanism of various metabolic disease progression and suggest the possibility of using circulatory miRNAs as prognostic predictors and therapeutic targets for improving clinical intervention strategies.

Integration of transcriptomics, metabolomics, and lipidomics reveals the mechanisms of doxorubicin-induced inflammatory responses and myocardial dysfunction in mice

Doxorubicin (DOX) is an anthracycline antineoplastic agent that has limited clinical utility due to its dose-dependent cardiotoxicity. Although the exact mechanism remains unknown, inflammatory responses have been implicated in DOX-induced cardiotoxicity (DIC). In this study, we analyzed the transcriptomic, metabolomic as well as lipidomic changes in the DOX-treated mice to explore the underlying mechanisms of DIC. We found that continuous intraperitoneal DOX injections (3 mg/kg/d) for a period of five days significantly induced cardiac dysfunction and cardiac injury in male C57BL/6 J mice (8 weeks old). This corresponded to a significant increase in the myocardial levels of IL-4, IL-6, IL-10, IL-17 and IL-12p70. Furthermore, inflammation-related genes such as Ptgs2, Il1b, Cxcl5, Cxcl1, Cxcl2, Mmp3, Ccl2, Ccl12, Nfkbia, Fos, Mapk11 and Tnf were differentially expressed in the DOX-treated group, and enriched in the IL-17 and TNF signaling pathways. Besides, amino acids, peptides, imidazoles, toluenes, hybrid peptides, fatty acids and lipids such as Hex1Cer, Cer, SM, PG and ACCa were significantly associated with the expression pattern of inflammation-related genes. In conclusion, the integration of transcriptomic, metabolomic and lipidomic data identified potential new targets and biomarkers of DIC.

The novel importance of miR-143 in obesity regulation

Obesity and substantially increased risk of metabolic diseases have become a global epidemic. microRNAs have attracted a great deal of attention as a potential therapeutic target for obesity. MiR-143 has been known to specifically promote adipocyte differentiation by downregulating extracellular signal-regulated kinase 5. Our latest study found that miR-143 knockout is against diet-induced obesity by promoting brown adipose tissue thermogenesis and inhibiting white adipose tissue adipogenesis. Moreover, LPS- or IL-6-induced inhibition of miR-143 expression in brown adipocytes promotes thermogenesis by targeting adenylate cyclase 9. In this review, we will summarize the expression and functions of miR-143 in different tissues, the influence of obesity on miR-143 in various tissues, the important role of adipose-derived miR-143 in the development of obesity, the role of miR-143 in immune cells and thermoregulation and discuss the potential significance and application prospects of miR-143 in obesity management.

LPS-Induced Inhibition of miR-143 Expression in Brown Adipocytes Promotes Thermogenesis and Fever

Fever is an important part of inflammatory response to infection. Although brown adipose tissue (BAT) thermogenesis is known to be potently influenced by systemic inflammation, the role of BAT during infection-induced fever remains largely unknown. Here, we injected mice with a low dose of LPS and found that low-dose LPS can directly induce thermogenesis of brown adipocytes. It is known that miR-143 is highly expressed in the BAT, and miR-143 knockout mice exhibited stronger thermogenesis under cold exposure. Interestingly, miR-143 was negatively correlated with an LPS-induced increase of TNFα and IL-6 mRNA levels, and the IL-6 pathway may mediate the inhibition of miR-143 expression. Moreover, miR-143 is down-regulated by LPS, and overexpression of miR-143 in brown adipocytes by lentivirus could rescue the enhancement of UCP1 protein expression caused by LPS, hinting miR-143 may be an important regulator of the thermogenesis in brown adipocytes. More importantly, the knockout of miR-143 further enhanced the LPS-induced increase of body temperature and BAT thermogenesis, and this result was further confirmed by in vitro experiments by using primary brown adipocytes. Mechanistically, adenylate cyclase 9 (AC9) is a new target gene of miR-143 and LPS increases BAT thermogenesis by a way of inhibiting miR-143 expression, a negative regulator for AC9. Our study considerably improves our collective understanding of the important function of miR-143 in inflammatory BAT thermogenesis.

miR-143-null Is against Diet-Induced Obesity by Promoting BAT Thermogenesis and Inhibiting WAT Adipogenesis

Excessive energy intake is the main cause of obesity, and stimulation of brown adipose tissue (BAT) thermogenesis has emerged as an attractive tool for anti-obesity. Although miR-143 has been reported to promote white adipocyte differentiation, its role in BAT remains unclear. In our study, we found that during HFD-induced obesity, the expression of miR-143 in BAT was significantly reduced, and the expression of miR-143 in WAT first increased and then decreased. Knockout (KO) of miR-143 with CRISPR/Cas9 did not affect the energy metabolism of normal diet fed mice and brown adipocyte differentiation but inhibited the differentiation of white adipocytes. Importantly, during high fat diet-induced obesity, miR-143KO significantly reduced body weight, and improved energy expenditure, insulin sensitivity, and glucose tolerance. Further exploration showed that miR-143KO reduced the weight of adipose tissue, promoted mitochondrial number and functions, induced thermogenesis and lipolysis of BAT, increased lipolysis, and inhibited lipogenesis of white adipose tissue (WAT). Our study considerably improves our collective understanding of the function of miR-143 in adipose tissue and its potential significance in anti-obesity and provides a new avenue for the management of obesity through the inhibition of miR-143 in BAT and WAT.

miR-146a-5p promotes epithelium regeneration against LPS-induced inflammatory injury via targeting TAB1/TAK1/NF-κB signaling pathway

Intestinal inflammation often restricts the health and production of animals. MiR-146a has been proved to be an anti-inflammatory molecule in inflammatory disorders, but its role in the intestinal injury and regeneration remains unclear. The study aimed to explore the inflammatory response of intestinal epithelial cells (IECs) in intestinal tissue-specific miR-146a-5p knockout mouse models. We identified the role of miR-146a-5p in inhibiting inflammatory response and promoting proliferation under lipopolysaccharide (LPS) stimulation in vitro and vivo. LPS stimulation significantly increased the expression of TNF-α, IL6 and inhibited IPEC-J2 cell proliferation. Overexpression of miR-146a-5p can reverse the effect of LPS stimulation, and promote the proliferation of intestinal epithelial cells. In the LPS challenge experiment in intestine-specific miR-146a knock-out mice (CKO) and Floxp^+/+ mice (CON), CKO mice were more sensitive to LPS stimulation, with more weight loss and more severe intestinal morphological damage than CON mice. Also, miR-146a-5p regulated LPS-induced intestinal injury, inflammation by targeting TAB1. Taken together, miR-146a may function as an anti-inflammatory factor in IECs by targeting TAB1/TAK1-IKK-NF-κB signaling pathway. miR-146a-5p may represent a promising biomarker for inflammatory disorders, and may provide an effective therapeutic method to alleviate weaning stress in piglets and some experimental basis to improve the intestinal health of livestock.