Lysine 2-hydroxyisobutyrylation levels determined adipogenesis and fat accumulation in adipose tissue in pigs.

BACKGROUND: Excessive backfat deposition lowering carcass grade is a major concern in the pig industry, especially in most breeds of obese type pigs. The mechanisms involved in adipogenesis and fat accumulation in pigs remain unclear. Lysine 2-hydroxyisobutyrylation (Khib), is a novel protein post-translational modification (PTM), which play an important role in transcription, energy metabolism and metastasis of cancer cells, but its role in adipogenesis and fat accumulation has not been shown. RESULTS: In this study, we first analyzed the modification levels of acetylation (Kac), Khib, crotonylation (Kcr) and succinylation (Ksu) of fibro-adipogenic progenitors (FAPs), myogenic precursors (Myo) and mesenchymal stem cells (MSCs) with varied differentiation potential, and found that only Khib modification in FAPs was significantly higher than that in MSCs. Consistently, in parallel with its regulatory enzymes lysine acetyltransferase 5 (KAT5) and histone deacetylase 2 (HDAC2) protein levels, the Khib levels increased quadratically (P < 0.01) during adipogenic differentiation of FAPs. KAT5 knockdown in FAPs inhibited adipogenic differentiation, while HDAC2 knockdown enhanced adipogenic differentiation. We also demonstrated that Khib modification favored to adipogenic differentiation and fat accumulation by comparing Khib levels in FAPs and backfat tissues both derived from obese-type pigs (Laiwu pigs) and lean-type pigs (Duroc pigs), respectively. Accordingly, the expression patterns of KAT5 and HDAC2 matched well to the degree of backfat accumulation in obese- and lean-type pigs. CONCLUSIONS: From the perspective of protein translational modification, we are the first to reveal the role of Khib in adipogenesis and fat deposition in pigs, and provided new clues for the improvement of fat accumulation and distribution as expected via genetic selection and nutritional strategy in obese-type pigs.

Multiomics reveals the ameliorating effect and underlying mechanism of aqueous extracts of polygonatum sibiricum rhizome on obesity and liver fat accumulation in high-fat diet-fed mice.

BACKGROUND: Polygonatum sibiricum polysaccharides protect against obesity and NAFLD. However, the potential effects of PS rhizome aqueous extracts (PSRwe) on adiposity and hepatic lipid accumulation remains unexplored. PURPOSE: Elucidating the impact and underlying mechanism of PSRwe on HFD-induced obesity and liver fat depostition. STUDY DESIGN: 56 male mice, aged eight weeks, were divided into seven groups: Positive, four doses of PSRwe, Model, and Control. HFD was fed for eight weeks, followed by alternate-day gavage of orlistat and PSRwe for an additional eight-week period. Integrative analysis encompassing multiomics, physiological and histopathological, and biochemical indexes was employed. METHODS: Body weight (BW); liver, fat and Lee's indexes; TC, TG, LDL-C, HDL-C, AST, ALT, FFA, leptin, and adiponectin in the liver and blood; TNFα, IL-6, and LPS in the colon, plasma, and liver; H&E, PAS and oil red O staining on adipose and liver samples were examined. OGTT and ITT were conducted The gut microbiome, microbial metabolome, colonic and liver transcriptome, plasma and liver metabolites were investigated. RESULTS: PSRwe at the dosage of 7.5 mg/kg demonstrated significant and consistent reduction in BW and hepatic fat deposition than orlistat. PSRwe significantly decreased TC, TG, LDL-C, LEP, FFA levels in blood and liver. PSRwe significantly enhanced the relative abundance of probiotics including Akkermansia muciniphila, Bifidobacterium pseudolongum, Lactobacillus reuteri, and metabolic pathways including glycolysis and fatty acids ß-oxidation. The 70 up-regulated microbial metabolites in PSRwe-treated mice mainly involved in nucleotides and amino acids metabolism, while 40 decreased metabolites primarily associated with lipid metabolism. The up-regulated colonic differentially expressed genes (DEGs) participate in JAK-STAT/PI3K-Akt/FoxO signaling pathway, serotonergic/cholinergic/glutamatergic synapses, while the down-regulated DEGs predominantly focused on fat absorption and transport. The up-regulated liver DEGs mainly concentrated on fatty acid oxidation and metabolism. Liver metabolisms revealed 131 differential metabolites, among which carnitine and oxidized lipids significantly increased in PSRwe-treated mice. In plasma, the 58 up-regulated metabolites mainly participate in co-factors/vitamins metabolism while 154 down-regulated ones in fatty acids biosynthesis. Comprehensive multiomics association analysis revealed significant associations between gut microbiota and colonic/liver gene expression, and suggested exogenous and endogenous betaine may be active compound in alleviating HFD-induced symptoms. CONCLUSION: PSRwe effectively mitigate HFD-induced obesity and hepatic steatosis by increasing beneficial bacteria, reducing colonic fat digestion/absorption, increasing hepatic lipid metabolism, and elevating betaine levels.

Pueraria lobata antioxidant extract ameliorates non-alcoholic fatty liver by altering hepatic fat accumulation and oxidative stress.

ETHNOPHARMACOLOGICAL RELEVANCE: Pueraria lobata is essential medicinal and edible homologous plants widely cultivated in Asian countries. Therefore, P. lobata is widely used in the food, health products and pharmaceutical industries and have significant domestic and international market potential and research value. P. lobata has remarkable biological activities in protecting liver, relieving alcoholism, antioxidation, anti-tumor and anti-inflammation in clinic. However, the potential mechanism of ethyl acetate extract of Pueraria lobata after 70% alcohol extraction (APL) ameliorating nonalcoholic fatty liver disease (NAFLD) has not been clarified. AIM OF THE STUDY: This study aimed to investigate the ameliorative effect of P. lobata extract on human hepatoma cells and injury in rats, and to evaluate its therapeutic potential for ameliorating NAFLD. METHODS: Firstly, the effective part of P. lobata extract was determined as APL by measuring its total substances and antioxidant activity. And then the in vitro and in vivo models of NAFLD were adopted., HepG2 cells were incubated with palmitic acid (PA) and hydrogen peroxide (H2O2). In order to evaluate the effect of APL, Simvastatin and Vitamin C (VC) were used as positive control. Various parameters related to lipogenesis and fatty acid ß-oxidation were studied, such as intracellular lipid accumulation, reactive oxygen species (ROS), Western Blot, mitochondrial membrane potential, apoptosis, and the mechanism of APL improving NAFLD. The chemical components of APL were further determined by HPLC and UPLC-MS, and molecular docking was carried out with Keap1/Nrf2/HO-1 pathway related proteins. RESULTS: APL significantly reduced lipid accumulation and levels of oxidative stress-related factors in vitro and in vivo. Immunohistochemical、Western Blot and PCR analysis showed that the expressions of Nrf2 and HO-1 were up-regulated in APL treatment. The Nrf2 inhibitor ML385 can block the rescue by APL of cellular oxidative stress and lipid accumulation induced by H2O2 and PA, demonstrating its dependence on Nrf2. UPLC/MS analysis showed that there were 3'-hydroxyl puerarin, puerarin, 3'-methoxy puerarin, daidzein, genistin, ononin, daidzin and genistein. CONCLUSION: This study further clarified the mechanism of P. lobata extract in improving NAFLD, which provided a scientific basis for developing new drugs to protect liver injury and laid a solid foundation for developing P. lobata Chinese herbal medicine resources.

The Probiotic Strain Lactobacillus acidophilus CL1285 Reduces Fat Deposition and Oxidative Stress and Increases Lifespan in Caenorhabditis elegans.

Caenorhabditis elegans was recently shown to be a powerful model for studying and identifying probiotics with specific functions. Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2, which are three bacteria that were marketed by Bio-K+, were evaluated using the nematode C. elegans to study fat accumulation, lifespan, and resistance to oxidative stress. Although the general effects of probiotics in terms of protection against oxidative stress were highlighted, the CL1285 strain had an interesting and specific feature, namely its ability to prevent fat accumulation in nematodes; this effect was verified by both the Oil Red and Nile Red methods. This observed phenotype requires daf-16 and is affected by glucose levels. In addition, in a daf-16- and glucose-dependent manner, CL1285 extended the lifespan of C. elegans; this effect was unique to CL1285 and not found in the other L. acidophilus subtypes in this study. Our findings indicate that L. acidophilus CL1285 impacts fat/glucose metabolism in C. elegans and provides a basis to further study this probiotic, which could have potential health benefits in humans and/or in mammals.

Sleep deprivation induced fat accumulation in the visceral white adipose tissue by suppressing SIRT1/FOXO1/ATGL pathway activation.

Sleep is critical for maintaining overall health. Insufficient sleep duration and poor sleep quality are associated with various physical and mental health risks and chronic diseases. To date, plenty of epidemiological research has shown that sleep disorders are associated with the risk of obesity, which is usually featured by the expansion of adipose tissue. However, the underlying mechanism of increased fat accumulation upon sleep disorders remains unclear. Here we demonstrated that sleep deprivation (SD) caused triglycerides (TG) accumulation in the visceral white adipose tissue (vWAT), accompanied by a remarkable decrease in the expression of adipose triglyceride lipase (ATGL) and other two rate-limiting lipolytic enzymes. Due to the key role of ATGL in initiating and controlling lipolysis, we focused on investigating the signaling pathway leading to attenuated ATGL expression in vWAT upon SD in the following study. We observed that ATGL downregulation resulted from the suppression of ATGL transcription, which was mediated by the reduction of the transcriptional factor FOXO1 and its upstream regulator SIRT1 expression in vWAT after SD. Furthermore, impairment of SIRT1/FOXO1/ATGL pathway activation and lipolysis induced by SIRT1 inhibitor EX527 in the 3 T3-L1 adipocytes were efficiently rescued by the SIRT1 activator resveratrol. Most notably, resveratrol administration in SD mice revitalized the SIRT1/FOXO1/ATGL pathway activation and lipid mobilization in vWAT. These findings suggest that targeting the SIRT1/FOXO1/ATGL pathway may offer a promising strategy to mitigate fat accumulation in vWAT and reduce obesity risk associated with sleep disorders.

Detraining after short-term exercise induces hyperphagia and obesity with fatty liver and brown adipose tissue whitening in young male OLETF rats.

This study examined the effects of exercise and detraining at a young age on fat accumulation in various organs. Four-week-old male Otsuka Long-Evans Tokushima Fatty (OLETF) rats were assigned to either the non-exercise sedentary (OLETF Sed) or exercise groups. The exercise group was subdivided into two groups: exercise between 4 and 12 weeks of age (OLETF Ex) and exercise between 4 and 6 weeks of age followed by non-exercise between 6 and 12 weeks of age (OLETF DT). Body weight was significantly lower in the OLETF Ex group than in the OLETF Sed group at 12 weeks of age. Fat accumulation in the epididymal white adipose tissue, liver, and brown adipose tissue was suppressed in the OLETF Ex group. During the exercise period, body weight and food intake in the OLETF DT group were significantly lower than those in the OLETF Sed group. However, food intake was significantly higher in the OLETF DT group than in the OLETF Sed group after exercise cessation, resulting in extreme obesity with fatty liver and brown adipose tissue whitening. Detraining after early-onset exercise promotes hyperphagia, causing extreme obesity. Overeating should be avoided during detraining periods in cases of exercise cessation at a young age.

Clostridium sporogenes increases fat accumulation in mice by enhancing energy absorption and adipogenesis.

Gut bacteria belonging to the Clostridium family play a pivotal role in regulating host energy balance and metabolic homeostasis. As a commensal bacterium, Clostridium sporogenes has been implicated in modulating host energy homeostasis, albeit the underlying mechanism remains elusive. Therefore, this study aimed to investigate the impact of C. sporogenes supplementation on various physiological parameters, intestinal morphology, particularly adipose tissue accumulation, and glucolipid metabolism in mice. The findings reveal that mice supplemented with C. sporogenes for 6 weeks exhibited a notable increase in body weight, fat mass, adipocyte size, and serum triglyceride (TG) levels. Notably, the increased fat accumulation is observed despite consistent feed intake in treated mice. Mechanistically, C. sporogenes supplementation significantly improved the structure integrity of intestinal villi and enhanced energy absorption efficiency while reducing excretion of carbohydrates and fatty acids in feces. This was accompanied by upregulation of glucose and fatty acid transporter expression. Furthermore, supplementation with C. sporogenes promoted adipogenesis in both liver and adipose tissues, as evidenced by increased levels of hepatic pyruvate, acetyl-CoA, and TG, along with elevated expression levels of genes associated with lipid synthesis. Regarding the microbiological aspect, C. sporogenes supplementation correlated with an increased abundance of Clostridium genus bacteria and enhanced carbohydrate enzyme activity. In summary, C. sporogenes supplementation significantly promotes fat accumulation in mice by augmenting energy absorption and adipogenesis, possibly mediated by the expansion of Clostridium bacteria population with robust glycolipid metabolic ability. IMPORTANCE: The Clostridia clusters have been implicated in energy metabolism, the specific species and underlying mechanisms remain unclear. This present study is the first to report Clostridium sporogenes is able to affect fat accumulation and glycolipid metabolism. We indicated that gavage of C. sporogenes promoted the adipogenesis and fat accumulation in mice by not only increasing the abundance of Clostridium bacteria but by also enhancing the metabolic absorption of carbohydrates and fatty acids significantly. Obviously, changes of gut microbiota caused by the C. sporogenes, especially the significant increase of Clostridium bacteria, contributed to the fat accumulation of mice. In addition, the enhancement of Clostridium genus bacteria remarkably improved the synthesis of hepatic pyruvate, acetyl-CoA, and triglyceride levels, as well as reduced the excretion of fecal carbohydrates, short-chain fatty acids, and free fatty acids remarkably. These findings will help us to understand the relationship of specific bacteria and host energy homeostasis.

Competing endogenous RNA networks were associated with fat accumulation in skeletal muscle of aged male mice.

Muscle aging contributed to morbidity and mortality in the elderly adults by leading to severe outcomes such as frailty, falls and fractures. Post-transcriptional regulation especially competing endogenous RNA (ceRNA) mechanism may modulate the process of skeletal muscle aging. RNA-seq was performed in quadriceps of 6-month-old (adult) and 22-month-old (aged) male mice to identify differentially expressed ncRNAs and mRNAs and further construct ceRNA networks. Decreased quadriceps-body weight ratio and muscle fiber cross-sectional area as well as histological characteristics of aging were observed in the aged mice. Besides, there were higher expressions of atrogin-1 and MuRF-1 and lower expression of Myog, Myf4 and Myod1 in the quadriceps of aged mice relative to that of adult mice. The expression of 85 lncRNAs, 52 circRNAs, 10 miRNAs and 277 mRNAs were significantly dysregulated in quadriceps between the two groups, among which two ceRNA networks lncRNA 2700081O15Rik/circRNA_0000820-miR-673-3p-Tmem120b were constructed. Level of triglycerides and expression of PPARγ, C/EBPα, FASN and leptin were elevated and the expression of adiponectin was reduced in quadriceps of aged mice compared with that of adult mice. LncRNA 2700081O15Rik/circRNA_0000820-miR-673-3p-Tmem120b were possibly associated with the adipogenesis and fat accumulation in skeletal muscle of age male mice.

Growth increase and gonadal dysfunction of the lined seahorse triggered by zinc exposure.

Seahorses are characterized by unique characteristics such as a male pregnancy reproductive strategy and grasping preferences, which make these species vulnerable to various environmental risks. Zinc (Zn) is one of the most frequently occurring toxic elements in coastal waters; however, little is known about the effect of Zn exposure on seahorses. In the present study, line seahorses (Hippocampus erectus) were exposed to waterborne Zn (0.2 and 1.0 mg/L) and the impact on growth and gonadal development was investigated. Zn exposure induced growth improvement, but also led to gonadal dysfunction in the lined seahorse. Female seahorses exhibited high testosterone levels, immature follicles, and weight increase after Zn exposure, which is the typical characteristics of a polycystic ovary syndrome (PCOS)-like phenotype. Transcriptomic data suggested that the Zn-induced growth promotion resulted from the dysregulated expression of fat accumulation genes. Further investigation of gene expression profiles in the brain, ovaries, and testes indicated that Zn affected the expression of genes involved in growth, immunity, tissue remodeling, and gonadal development by regulating serum steroid hormone levels and androgen receptor expression. This study not only clarifies the complex impact of Zn on seahorses using physiological, histological, and molecular evidence but can also provide new insights into the mechanism underlying PCOS in reproductive-aged women. Moreover, this work demonstrates the risk of the common practice of Zn supplementation in the aquaculture industry as the consequent growth yield may not represent a healthy condition.

Effects of low protein feed on hepato-intestinal health and muscle quality of grass carp (Ctenopharyngodon idellus).

In this study, grass carp (33.28 ± 0.05 g) were fed three diets for 8 weeks: control (crude protein [CP] 30%, crude lipid [CL] 6%), low protein (LP; CP16%, CL6%), and low protein with high-fat (LPHF; CP16%, CL10%). The final body weight decreased in the LP and LPHF groups compared to the Control (P < 0.05). Liver triglycerides, total cholesterol, and nonesterified fatty acids were higher in the LP group than the Control, whereas these indexes in the LPHF group were higher than those in the LP group (P < 0.05). The LP group had intestinal barrier damage, while the LPHF group had a slight recovery. TNF-α, IL-8, and IL-1ß content were lower in the LP group than in the Control (P < 0.05), and even higher in the LPHF group (P < 0.05). The expressions of endoplasmic reticulum stress-related genes Activating transcription factor 6 (ATF-6) and Glucose-regulated protein (GRP78) were higher in the LPHF group against the LP group (P < 0.05). The IL-1ß and TNF-α content negatively correlated with intestinal Actinomycetes and Mycobacterium abundance (P < 0.05). The muscle fiber diameter was smaller in both the LP and LPHF groups than the control (P < 0.05), with the LP group showing metabolites related to protein digestion and absorption, and LPHF group exhibiting metabolites related to taste transmission. The results demonstrate reducing dietary protein affects growth, causing liver lipid accumulation, reduced enteritis response, and increased muscle tightness, while increasing fat content accelerates fat accumulation and inflammation.

Subtherapeutic Kitasamycin Promoted Fat Accumulation in the Longissimus Dorsi Muscle in Growing-Finishing Pigs.

Kitasamycin (KM), a broad-spectrum macrolide antibiotic, has implications for growth performance and residue in animals and humans. This study aimed to explore the effects of different KM doses on intramuscular fat accumulation, cecal microflora, and short-chain fatty acids (SCFAs) using a growing-finishing pig model. Forty-two pigs were divided into three groups: control, subtherapeutic KM (50 mg/kg, KM50), and therapeutic KM (200 mg/kg, KM200) diets over 8 weeks. KM50 led to increased back fat thickness, fat content in the longissimus dorsi muscle (LM), and elevated plasma total cholesterol (TC) levels (p < 0.05), supported by upregulated lipid synthesis gene expression (Acc1, Fas, Scd1) (p < 0.05) in the LM. KM50 altered cecal microflora, reducing Lactobacillus spp. and Bifidobacterium spp. abundance, while increasing SCFA concentrations (acetic acid, propionic acid, total SCFAs) (p < 0.05). KM200 had minimal effects on intestinal weight and density, with increased apparent digestibility of nutrients. These findings highlight the dose-dependent impact of KM on intramuscular fat deposition. Subtherapeutic KM induced ectopic fat deposition, emphasizing potential risks in disease treatment for humans and animals.

Impacts of the vegetable Urtica dioica on the intestinal T and B cell phenotype and macronutrient absorption in C57BL/6J mice with diet-induced obesity.

In two previous studies, we showed that supplementing a high-fat (HF) diet with 9% w/w U. dioica protects against fat accumulation, insulin resistance, and dysbiosis. This follow-up study in C57BL6/J mice aimed at testing: (i) the efficacy of the vegetable at lower doses: 9%, 4%, and 2%, (ii) the impact on intestinal T and B cell phenotype and secretions, (iii) impact on fat and glucose absorption during excess nutrient provision. At all doses, the vegetable attenuated HF diet induced fat accumulation in the mesenteric, perirenal, retroperitoneal fat pads, and liver but not the epididymal fat pad. The 2% dose protected against insulin resistance, prevented HF diet-induced decreases in intestinal T cells, and IgA+ B cells and activated T regulatory cells (Tregs) when included both in the LF and HF diets. Increased Tregs correlated with reduced inflammation; prevented increases in IL6, IFNγ, and TNFα in intestine but not expression of TNFα in epididymal fat pad. Testing of nutrient absorption was performed in enteroids. Enteroids derived from mice fed the HF diet supplemented with U. dioica had reduced absorption of free fatty acids and glucose compared to enteroids from mice fed the HF diet only. In enteroids, the ethanolic extract of U. dioica attenuated fat absorption and downregulated the expression of the receptor CD36 which facilitates uptake of fatty acids. In conclusion, including U. dioica in a HF diet, attenuates fat accumulation, insulin resistance, and inflammation. This is achieved by preventing dysregulation of immune homeostasis and in the presence of excess fat, reducing fat and glucose absorption.

Association of seasonal changes in circulating cortisol concentrations with the expression of cortisol biosynthetic enzymes and a glucocorticoid receptor in the blubber of common bottlenose dolphin.

Cortisol is secreted from the adrenal cortex in response to stress, and its circulating levels are used as robust physiological indicators of stress intensity in various animals. Cortisol is also produced locally in adipose tissue by the conversion of steroid hormones such as cortisone, which is related to fat accumulation. Circulating cortisol levels, probably induced by cold stress, increase in cetaceans under cold conditions. However, whether cortisol production in subcutaneous adipose tissue is enhanced when fat accumulation is renewed during the cold season remains unclear. Therefore, in this study, we examine the effect of environmental temperature on the expression of cortisol synthesis-related enzymes and a glucocorticoid receptor in the subcutaneous fat (blubber) and explore the association between these expressions and fluctuations in circulating cortisol levels in common bottlenose dolphins (Tursiops truncatus). Skin biopsies were obtained seasonally from eight female dolphins, and seasonal differences in the expression of target genes in the blubber were analyzed. Blood samples were collected throughout the year, and cortisol levels were measured. We found that the expressions of cytochrome P450 family 21 subfamily A member 2 (CYP21A2) and nuclear receptor subfamily 3 group C member 1 (NR3C1), a glucocorticoid receptor, were increased in the cold season, and 11 beta-hydroxysteroid dehydrogenase type 1 (HSD11B1) showed a similar trend. Blood cortisol levels increased when the water temperature decreased. These results suggest that the conversion of 17-hydroxyprogesterone to cortisol via 11-deoxycortisol and/or of cortisone to cortisol is enhanced under cold conditions, and the physiological effects of cortisol in subcutaneous adipose tissue may contribute to on-site lipid accumulation and increase the circulating cortisol concentrations. The results obtained in this study highlight the role of cortisol in the regulation of the blubber that has developed to adapt to aquatic life.

Influence of glucagon-like peptide-1 receptor agonists on fat accumulation in patients with diabetes mellitus and non-alcoholic fatty liver disease or obesity: A systematic review and meta-analysis of randomized control trials.

AIM: This systematic review and meta-analysis aimed to comprehensively evaluate the impact of glucagon-like peptide 1 receptor agonists (GLP-1RAs) on visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in individuals with diabetes mellitus and non-alcoholic fatty liver disease (NAFLD) or obesity. METHODS: A search of PubMed, Embase, and Web of Science until October 2023 identified 13 Randomized Controlled Trials (RCTs) meeting the inclusion criteria. Bias risk was assessed using the Cochrane risk-of-bias instrument. Statistical analysis utilized standard mean differences (SMD) in Review Manager 5.4. Heterogeneity and publication bias were assessed. This study used the protocol registered with the Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY2023110020). RESULTS: GLP-1RA treatment significantly reduced VAT (SMD -0.55, 95 % CI [-0.90, -0.19]), SAT (SMD -0.59, 95 % CI [-0.99, -0.19]), body weight (SMD -1.07, 95 % CI [-1.67, -0.47]), and body mass index (BMI) (SMD -1.10, 95 % CI [-1.74, -0.47]) compared to controls. Heterogeneity was observed for VAT (I2 = 79 %, P < 0.01), SAT (I2 = 73 %, P < 0.01), body weight (I2 = 82 %, P < 0.01), and BMI (I2 = 82 %, P < 0.01). No publication bias was detected for VAT (P = 0.57) and SAT (P = 0.18). GLP-1RA treatment improved fasting blood glucose (FBG), postprandial glucose (PPG), hemoglobin A1c (HbA1c), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and fibrosis-4 (FIB-4). CONCLUSIONS: This meta-analysis highlights GLP-1RAs' potential to reduce fat accumulation, body weight, and BMI and improve glycemic control in individuals with diabetes mellitus and NAFLD or obesity. These findings supported using GLP-1RAs as promising therapeutic agents to address abnormal adipose tissue distribution and metabolic dysfunction.

Transcriptome and Metabolome Analyses Provide Insight into the Glucose-Induced Adipogenesis in Porcine Adipocytes.

Glucose is a major energy substrate for porcine adipocytes and also serves as a regulatory signal for adipogenesis and lipid metabolism. In this study, we combined transcriptome and metabolome analyses to reveal the underlying regulatory mechanisms of high glucose (HG) on adipogenesis by comparing differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) identified in porcine adipocytes. Results showed that HG (20 mmol/L) significantly increased fat accumulation in porcine adipocytes compared to low glucose (LG, 5 mmol/L). A total of 843 DEGs and 365 DAMs were identified. Functional enrichment analyses of DEGs found that multiple pathways were related to adipogenesis, lipid metabolism, and immune-inflammatory responses. PPARγ, C/EBPα, ChREBP, and FOS were identified as the key hub genes through module 3 analysis, and PPARγ acted as a central regulator by linking genes involved in lipid metabolism and immune-inflammatory responses. Gene-metabolite networks found that PPARγ-13-HODE was the most important interaction relationship. These results revealed that PPARγ could mediate the cross-talk between adipogenesis and the immune-inflammatory response during adipocyte maturation. This work provides a comprehensive view of the regulatory mechanisms of glucose on adipogenesis in porcine adipocytes.

Vitamin D Mitigates Hepatic Fat Accumulation and Inflammation and Increases SIRT1/AMPK Expression in AML-12 Hepatocytes.

Emerging evidence has demonstrated a strong correlation between vitamin D status and fatty liver disease. Aberrant hepatic fat infiltration contributes to oxidant overproduction, promoting metabolic dysfunction, and inflammatory responses. Vitamin D supplementation might be a good strategy for reducing hepatic lipid accumulation and inflammation in non-alcoholic fatty liver disease and its associated diseases. This study aimed to investigate the role of the most biologically active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D), in hepatic fat accumulation and inflammation in palmitic acid (PA)-treated AML-12 hepatocytes. The results indicated that treatment with 1,25(OH)2D significantly decreased triglyceride contents, lipid peroxidation, and cellular damage. In addition, mRNA levels of apoptosis-associated speck-like CARD-domain protein (ASC), thioredoxin-interacting protein (TXNIP), NOD-like receptor family pyrin domain-containing 3 (NLRP3), and interleukin-1ß (IL-1ß) involved in the NLRP3 inflammasome accompanied by caspase-1 activity and IL-1ß expression were significantly suppressed by 1,25(OH)2D in PA-treated hepatocytes. Moreover, upon PA exposure, 1,25(OH)2D-incubated AML-12 hepatocytes showed higher sirtulin 1 (SIRT1) expression and adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. A SIRT1 inhibitor alleviated the beneficial effects of 1,25(OH)2D on PA-induced hepatic fat deposition, IL-1ß expression, and caspase-1 activity. These results suggest that the favorable effects of 1,25(OH)2D on hepatic fat accumulation and inflammation may be, at least in part, associated with the SIRT1.

Multiomics analysis reveals that microbiota regulate fat and muscle synthesis in chickens.

Intestinal microbiota regulates the host metabolism, including fat metabolism and muscle development in mammals; however, studies on the interactions between the gut microbiome and in chickens with respect to fat metabolism and muscle development are still rare. We established a germ-free (GF) chicken model to determine the transcriptomes and metabolomes of GF and specific-pathogen-free (SPF) chickens. Transcriptome analysis showed 1,282 differentially expressed genes (DEGs) in GF and SPF chickens. The expression levels of some genes related to muscle formation were very high in SPF chickens but low in GF chickens, suggesting that GF chickens had poorer muscle development ability. In contrast, the expression levels of some fat synthesis-related genes were very low in SPF chickens but high in GF chickens, suggesting that GF chickens had a more potent fat-synthesizing ability. Metabolome analysis revealed 62 differentially expressed metabolites (DEMs) in GF and SPF chickens, of which 35 were upregulated and 27 were downregulated. Furthermore, the Pearson correlation coefficient (PCC) was calculated, and an interaction network was constructed to visualize the crosstalk between the genes, metabolites, and gut microbiota in GF and SPF chickens. The top 10 gut microbiota were positively correlated with lipid metabolism including13(S)-HpODE and 9(S)-HpOTrE, and genes related to muscle development, while were negatively correlated with genes related to fat synthesis. In conclusion, this study indicated that chicken intestinal microbiota regulate host metabolism, inhibit fat synthesis, and may promote muscle development.

Medium- and Long-Chain Triacylglycerol: Preparation, Health Benefits, and Food Utilization.

Medium- and long-chain triacylglycerol (MLCT) is a structured lipid with both medium- and long-chain fatty acids in one triacylglycerol molecule. Compared with long-chain triacylglycerol (LCT), which is mainly present in common edible oils, and the physical blend of medium-chain triacylglycerol with LCT (MCT/LCT), MLCT has different physicochemical properties, metabolic characteristics, and nutritional values. In this article, the recent advances in the use of MLCT in food formulations are reviewed. The natural sources and preparation of MLCT are discussed. A comprehensive summary of MLCT digestion, absorption, transport, and oxidation is provided as well as its health benefits, including reducing the risk of overweight, hypolipidemic and hypoglycemic effects, etc. The potential MLCT uses in food formulations, such as infant formulas, healthy foods for weight loss, and sports foods, are summarized. Finally, the current safety assessment and regulatory status of MLCT in food formulations are reviewed.

Gastric Submucosal Fat Accumulation Is Associated with Insulin Resistance in Patients with Obesity.

PURPOSE: Ectopic fat accumulation plays a significant role in obesity-related metabolic dysfunction, and few studies have reported an association between ectopic gastric fat and metabolic risk factors. We aim to fulfill this need by assessing the degree of gastric submucosal fat accumulation in pathologic sections of 190 sleeve gastrectomy specimens. METHODS: Study patients were divided into two groups (D1 and D2) based on whether fat accumulation exceeded 1/3 of the submucosa of the stomach. Demographic and metabolic risk factors were compared between the two groups. Metabolic risk variables that might be associated with the degree of fat accumulation were screened in the original cohort. After balancing for possible confounders, the robustness of the correlations was assessed using binary and conditional logistic regression analyses. RESULTS: All study patients had fat accumulation in the submucosa of the stomach. C-reactive protein (CRP), body mass index (BMI), visceral fat area (VFA), and insulin resistance (IR) were higher in the D2 group than in the D1 group in the original cohort (P < 0.05). Logistic regression analysis showed that BMI and IR may be associated with increased fat accumulation. After balancing variables other than obesity indicators and IR using propensity score matching, BMI and IR remained significantly different between the two groups (P < 0.05). Further analysis of the matched cohort using two logistic regression analyses showed that IR was an independent risk factor for increased fat accumulation. CONCLUSION: This study indicated that gastric submucosal fat accumulation was prevalent in patients with obesity and was associated with IR.

Correlation between plasma glutamate and adiponectin in patients with type 2 diabetes.

Visceral fat accumulation is a major determinant of type 2 diabetes mellitus and cardiovascular diseases. Recent studies have reported that glutamate is the most elevated amino acid in the plasma amino acid profile in patients with obesity and/or visceral fat accumulation. Here, we show the relationship between plasma glutamate and the clinical features of patients with type 2 diabetes. The study subjects were 62 (28 men and 34 women) Japanese patients with type 2 diabetes. Blood profiles, including glutamate and adiponectin (APN) levels and estimated visceral fat area (eVFA), were measured. We also evaluated the plasma amino acid levels in mice with or without obesity by GC/MS analysis. In patients with type 2 diabetes, plasma glutamate was positively correlated with BMI, eVFA, and fasting insulin but negatively correlated with APN and duration of diabetes. Additionally, multiple regression analysis revealed that plasma glutamate was a significant determinant of APN. The plasma glutamate level was most significantly increased in obese mice compared to control mice, and it was negatively correlated with APN. These results suggest that the level of plasma glutamate could be a strong indicator of adipocyte dysfunction in patients with type 2 diabetes.