Lactobacillus casei-fermented Amomum xanthioides ameliorates metabolic dysfunction in high-fat diet-induced obese mice.

Amomum xanthioides (AX) has been used as an edible herbal medicine to treat digestive system disorders in Asia. Additionally, Lactobacillus casei is a well-known probiotic commonly used in fermentation processes as a starter. The current study aimed to investigate the potential of Lactobacillus casei-fermented Amomum xanthioides (LAX) in alleviating metabolic disorders induced by high-fat diet (HFD) in a mouse model. LAX significantly reduced the body and fat weight, outperforming AX, yet without suppressing appetite. LAX also markedly ameliorated excessive lipid accumulation and reduced inflammatory cytokine (IL-6) levels in serum superior to AX in association with UCP1 activation and adiponectin elevation. Furthermore, LAX noticeably improved the levels of fasting blood glucose, serum insulin, and HOMA-IR through positive regulation of glucose transporters (GLUT2, GLUT4), and insulin receptor gene expression. In conclusion, the fermentation of AX demonstrates a pronounced mitigation of overnutrition-induced metabolic dysfunction, including hyperlipidemia, hyperglycemia, hyperinsulinemia, and obesity, compared to non-fermented AX. Consequently, we proposed that the fermentation of AX holds promise as a potential candidate for effectively ameliorating metabolic disorders.

Conditioned overconsumption is dependent on reinforcer type in lean, but not obese, mice.

Associative learning can drive many different types of behaviors, including food consumption. Previous studies have shown that cues paired with food delivery while mice are hungry will lead to increased consumption in the presence of those cues at later times. We previously showed that overconsumption can be driven in male mice by contextual cues, using chow pellets. Here we extended our findings by examining other parameters that may influence the outcome of context-conditioned overconsumption training. We found that the task worked equally well in males and females, and that palatable substances such as high-fat diet and Ensure chocolate milkshake supported learning and induced overconsumption. Surprisingly, mice did not overconsume when sucrose was used as the reinforcer during training, suggesting that nutritional content is a critical factor. Interestingly, we also observed that diet-induced obese mice did not learn the task. Overall, we find that context-conditioned overconsumption can be studied in lean male and female mice, and with multiple reinforcer types.

Metabolic and Skeletal Characterization of the KK/Ay Mouse Model-A Polygenic Mutation Model of Obese Type 2 Diabetes.

Type 2 diabetes (T2D) increases fracture incidence and fracture-related mortality rates (KK.Cg-Ay/J. The Jackson Laboratory; Available from: https://www.jax.org/strain/002468 ). While numerous mouse models for T2D exist, few effectively stimulate persistent hyperglycemia in both sexes, and even fewer are suitable for bone studies. Commonly used models like db/db and ob/ob have altered leptin pathways, confounding bone-related findings since leptin regulates bone properties (Fajardo et al. in Journal of Bone and Mineral Research 29(5): 1025-1040, 2014). The Yellow Kuo Kondo (KK/Ay) mouse, a polygenic mutation model of T2D, is able to produce a consistent diabetic state in both sexes and addresses the lack of a suitable model of T2D for bone studies. The diabetic state of KK/Ay stems from a mutation in the agouti gene, responsible for coat color in mice. This mutation induces ectopic gene expression across various tissue types, resulting in diabetic mice with yellow fur coats (Moussa and Claycombe in Obesity Research 7(5): 506-514, 1999). Male and female KK/Ay mice exhibited persistent hyperglycemia, defining them as diabetic with blood glucose (BG) levels consistently exceeding 300 mg/dL. Notably, male control mice in this study were also diabetic, presenting a significant limitation. Nevertheless, male and female KK/Ay mice showed significantly elevated BG levels, HbA1c, and serum insulin concentration when compared to the non-diabetic female control mice. Early stages of T2D are characterized by hyperglycemia and hyperinsulinemia resulting from cellular insulin resistance, whereas later stages may feature hypoinsulinemia due to ß-cell apoptosis (Banday et al. Avicenna Journal of Medicine 10(04): 174-188, 2020 and Klein et al. Cell Metabolism 34(1): 11-20, 2022). The observed hyperglycemia, hyperinsulinemia, and the absence of differences in ß-cell mass suggest that KK/Ay mice in this study are modeling the earlier stages of T2D. While compromised bone microarchitecture was observed in this study, older KK/Ay mice, representing more advanced stages of T2D, might exhibit more pronounced skeletal manifestations. Compared to the control group, the femora of KK/Ay mice had higher cortical area and cortical thickness, and improved trabecular properties which would typically be indicative of greater bone strength. However, KK/Ay mice displayed lower cortical tissue mineral density in both sexes and increased cortical porosity in females. Fracture instability toughness of the femora was lower in KK/Ay mice overall compared to controls. These findings indicate that decreased mechanical integrity noted in the femora of KK/Ay mice was likely due to overall bone quality being compromised.

Fructooligosaccharides Intake during Pregnancy Improves Metabolic Phenotype of Offspring in High Fat Diet-Induced Obese Mice.

SCOPE: Obesity and metabolic diseases are closely associated, and individuals who become obese are also prone to type 2 diabetes and cardiovascular disorders. Gut microbiota is mediated by diet and can influence host metabolism and the incidence of metabolic disorders. Recent studies have suggested that improving gut microbiota through a fructooligosaccharide (FOS)-supplemented diet may ameliorate obesity and other metabolic disorders. Although accumulating evidence supports the notion of the developmental origins of health and disease, the underlying mechanisms remain obscure. METHODS AND RESULTS: ICR mice are fed AIN-93G formula-based cellulose -, FOS-, acetate-, or propionate-supplemented diets during pregnancy. Offspring are reared by conventional ICR foster mothers for 4 weeks; weaned mice are fed high fat diet for 12 weeks and housed individually. The FOS and propionate offspring contribute to suppressing obesity and improving glucose intolerance. Gut microbial compositions in FOS-fed mothers and their offspring are markedly changed. However, the beneficial effect of FOS diet on the offspring is abolished when antibiotics are administered to pregnant mice. CONCLUSION: The findings highlight the link between the maternal gut environment and the developmental origin of metabolic syndrome in offspring. These results open novel research avenues into preemptive therapies for metabolic disorders by targeting the maternal gut microbiota.

Resolvin D2 prevents vascular remodeling, hypercontractility and endothelial dysfunction in obese hypertensive mice through modulation of vascular and proinflammatory factors.

During resolution of inflammation, specialized proresolving mediators (SPMs), including resolvins, are produced to restore tissue homeostasis. We hypothesized that there might be a dysregulation of SPMs pathways in pathological vascular remodeling and that resolvin D2 (RvD2) might prevent vascular remodeling and contractile and endothelial dysfunction in a model of obesity and hypertension. In aortic samples of patients with or without abdominal aortic aneurysms (AAA), we evaluated gene expression of enzymes involved in SPMs synthesis (ALOXs), SPMs receptors and pro-inflammatory genes. In an experimental model of aortic dilation induced by high fat diet (HFD, 60%, eighteen weeks) and angiotensin II (AngII) infusion (four weeks), we studied the effect of RvD2 administration in aorta and small mesenteric arteries structure and function and markers of inflammation. In human macrophages we evaluated the effects of AngII and RvD2 in macrophages function and SPMs profile. In patients, we found positive correlations between AAA and obesity, and between AAA and expression of ALOX15, RvD2 receptor GPR18, and pro-inflammatory genes. There was an inverse correlation between the expression of aortic ALOX15 and AAA growth rate. In the mice model, RvD2 partially prevented the HFD plus AngII-induced obesity and adipose tissue inflammation, hypertension, aortic and mesenteric arteries remodeling, hypercontratility and endothelial dysfunction, and the expression of vascular proinflammatory markers and cell apoptosis. In human macrophages, RvD2 prevented AngII-induced impaired efferocytosis and switched SPMs profile. RvD2 might represent a novel protective strategy in preventing vascular damage associated to hypertension and obesity likely through effects in vascular and immune cells.

Dopamine D2 receptor antagonist counteracts hyperglycemia and insulin resistance in diet-induced obese male mice.

Obesity leads to insulin resistance (IR) and type 2 diabetes. In humans, low levels of the hormone prolactin (PRL) correlate with IR, adipose tissue (AT) dysfunction, and increased prevalence of T2D. In obese rats, PRL treatment promotes insulin sensitivity and reduces visceral AT adipocyte hypertrophy. Here, we tested whether elevating PRL levels with the prokinetic and antipsychotic drug sulpiride, an antagonist of dopamine D2 receptors, improves metabolism in high fat diet (HFD)-induced obese male mice. Sulpiride treatment (30 days) reduced hyperglycemia, IR, and the serum and pancreatic levels of triglycerides in obese mice, reduced visceral and subcutaneous AT adipocyte hypertrophy, normalized markers of visceral AT function (PRL receptor, Glut4, insulin receptor and Hif-1α), and increased glycogen stores in skeletal muscle. However, the effects of sulpiride reducing hyperglycemia were also observed in obese prolactin receptor null mice. We conclude that sulpiride reduces obesity-induced hyperglycemia by mechanisms that are independent of prolactin/prolactin receptor activity. These findings support the therapeutic potential of sulpiride against metabolic dysfunction in obesity.

Effects of Prevotella copri on insulin, gut microbiota and bile acids.

Obesity is becoming a major global health problem in children that can cause diseases such as type 2 diabetes and metabolic disorders, which are closely related to the gut microbiota. However, the underlying mechanism remains unclear. In this study, a significant positive correlation was observed between Prevotella copri (P. copri) and obesity in children (p = 0.003). Next, the effect of P. copri on obesity was explored by using fecal microbiota transplantation (FMT) experiment. Transplantation of P. copri. increased serum levels of fasting blood glucose (p < 0.01), insulin (p < 0.01) and interleukin-1ß (IL-1ß) (p < 0.05) in high-fat diet (HFD)-induced obese mice, but not in normal mice. Characterization of the gut microbiota indicated that P. copri reduced the relative abundance of the Akkermansia genus in mice (p < 0.01). Further analysis on bile acids (BAs) revealed that P. copri increased the primary BAs and ursodeoxycholic acid (UDCA) in HFD-induced mice (p < 0.05). This study demonstrated for the first time that P. copri has a significant positive correlation with obesity in children, and can increase fasting blood glucose and insulin levels in HFD-fed obese mice, which are related to the abundance of Akkermansia genus and bile acids.

Selective epigenetic alterations in RNF43 in pancreatic exocrine cells from high-fat-diet-induced obese mice; implications for pancreatic cancer.

OBJECTIVE: Pancreatic cancer (PC) originates and progresses with genetic mutations in various oncogenes and suppressor genes, notably KRAS, CDKN2A, TP53, and SMAD4, prevalent across diverse PC cells. In addition to genetic mutations/deletions, persistent exposure to high-risk factors, including obesity, induces whole-genome scale epigenetic alterations contributing to malignancy. However, the impact of obesity on DNA methylation in the presymptomatic stage, particularly in genes prone to PC mutation, remains uncharacterized. RESULTS: We analyzed the methylation levels of 197 loci in six genes (KRAS, CDKN2A, TP53, SMAD4, GNAS and RNF43) using Illumina Mouse Methylation BeadChip array (280 K) data from pancreatic exocrine cells obtained from high-fat-diet (HFD) induced obese mice. Results revealed no significant differences in methylation levels in loci between HFD- and normal-fat-diet (NFD)-fed mice, except for RNF43, a negative regulator of Wnt signaling, which showed hypermethylation in three loci. These findings indicate that, in mouse pancreatic exocrine cells, high-fat dietary obesity induced aberrant DNA methylation in RNF43 but not in other frequently mutated PC-related genes.

[Activation of α7 nAChR improves white fat homeostasis and promotes beige adipogenesis and thermogenesis in obese mice].

OBJECTIVE: To investigate the effects of α7 nicotinic acetylcholine receptor (nAChR) agonist on ß3-adrenoceptor agonist-induced impairment of white fat homeostasis and beige adipose formation and heat production in obese mice. METHODS: Forty obese C57BL/6J mice were randomized into high-fat feeding group, ß3-adrenoceptor agonist-treated model group, α7 nAChR agonist group, and α7 nAChR inhibitor group (n=10), with another 10 mice with normal feeding as the blank control group. White adipose tissue from the epididymis of the mice were sampled for HE staining of the adipocytes. The expression levels of TNF-α, IL-1ß, IL-10 and TGF-ß in the white adipose tissue were determined by ELISA, and the mRNA levels of iNOS, Arg1, UCP-1, PRDM-16 and PGC-1α were detected using RT-qPCR. Western blotting was performed to detect the expression levels of NF-κB P65, p-JAK2, p-STAT3 in the white adipose tissue. RESULTS: Compared with those in the blank control group, the mice with high-fat feeding showed significantly increased body weight, more fat vacuoles in the white adipose tissue, increased volume of lipid droplets in the adipocytes, upregulated iNOS mRNA expression and protein expression of TNF-α and IL-1ß, and lowered expression of Arg-1 mRNA and IL-10 and TGF-ß proteins (P < 0.01). Treatment with α7 nAChR significantly reduced mRNA levels of PRDM-16, PGC-1α and UCP-1, lowered TNF-α and IL-1ß expressions, increased IL-10 and TGF-ß expressions, and reduced M1/M2 macrophage ratio in the white adipose tissues (P < 0.05 or 0.01). CONCLUSION: Activation of α7 nAchR improves white adipose tissue homeostasis impairment induced by ß3 agonist, promotes transformation of M1 to M2 macrophages, reduces inflammatory response in white adipose tissue, and promote beige adipogenesis and thermogenesis in obese mice.

Anti-obesity potentiality of Lactiplantibacillus plantarum E2_MCCKT isolated from a fermented beverage, haria: a high fat diet-induced obese mice model study.

Obesity is a growing epidemic worldwide. Several pharmacologic drugs are being used to treat obesity but these medicines exhibit side effects. To find out the alternatives of these drugs, we aimed to assess the probiotic properties and anti-obesity potentiality of a lactic acid bacterium E2_MCCKT, isolated from a traditional fermented rice beverage, haria. Based on the 16S rRNA sequencing, the bacterium was identified as Lactiplantibacillus plantarum E2_MCCKT. The bacterium exhibited in vitro probiotic activity in terms of high survivability in an acidic environment and 2% bile salt, moderate auto-aggregation, and hydrophobicity. Later, E2_MCCKT was applied to obese mice to prove its anti-obesity potentiality. Adult male mice (15.39 ± 0.19 g) were randomly divided into three groups (n = 5) according to the type of diet: normal diet (ND), high-fat diet (HFD), and HFD supplemented with E2_MCCKT (HFT). After four weeks of bacterial treatment on the obese mice, a significant reduction of body weight, triglyceride, and cholesterol levels, whereas, improvements in serum glucose levels were observed. The bacterial therapy led to mRNA up-regulation of lipolytic transcription factors such as peroxisome proliferator-activated receptor-α which may increase the expression of fatty acid oxidation-related genes such as acyl-CoA oxidase and carnitine palmitoyl-transferase-1. Concomitantly, both adipocytogenesis and fatty acid synthesis were arrested as reflected by the down-regulation of sterol-regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase genes. In protein expression study, E2_MCCKT significantly increased IL-10 expression while decreasing pro-inflammatory cytokine (IL-1Ra and TNF-α) expression. In conclusion, the probiotic Lp. plantarum E2_MCCKT might have significant anti-obesity effects on mice.

Leptin signalling regulates transcriptional differences in granulosa cells from genetically obese mice but not the activation of NLRP3 inflammasome.

Obesity is associated with increased ovarian inflammation and the establishment of leptin resistance. We presently investigated the role of impaired leptin signalling on transcriptional regulation in granulosa cells (GCs) collected from genetically obese mice. Furthermore, we characterised the association between ovarian leptin signalling, the activation of the NOD-like receptor protein 3 (NLRP3) inflammasome and macrophage infiltration in obese mice. After phenotype characterisation, ovaries were collected from distinct group of animals for protein and mRNA expression analysis: (i) mice subjected to a diet-induced obesity (DIO) protocol, where one group was fed a high-fat diet (HFD) and another a standard chow diet (CD) for durations of 4 or 16 weeks; (ii) mice genetically deficient in the long isoform of the leptin receptor (ObRb; db/db); (iii) mice genetically deficient in leptin (ob/ob); and (iv) mice rendered pharmacologically hyperleptinemic (LEPT). Next, GCs from antral follicles isolated from db/db and ob/ob mice were subjected to transcriptome analysis. Transcriptional analysis revealed opposing profiles in genes associated with steroidogenesis and prostaglandin action between the genetic models, despite the similarities in body weight. Furthermore, we observed no changes in the mRNA and protein levels of NLRP3 inflammasome components in the ovaries of db/db mice or in markers of M1 and M2 macrophage infiltration. This contrasted with the downregulation of NLRP3 inflammasome components and M1 markers in ob/ob and 16-wk HFD-fed mice. We concluded that leptin signalling regulates NLRP3 inflammasome activation and the expression of M1 markers in the ovaries of obese mice in an ObRb-dependent and ObRb-independent manner. Furthermore, we found no changes in the expression of leptin signalling and NLRP3 inflammasome genes in GCs from db/db and ob/ob mice, which was associated with no effects on macrophage infiltration genes, despite the dysregulation of genes associated with steroidogenesis in homozygous obese db/db. Our results suggest that: (i) the crosstalk between leptin signalling, NLRP3 inflammasome and macrophage infiltration takes place in ovarian components other than the GC compartment; and (ii) transcriptional changes in GCs from homozygous obese ob/ob mice suggest structural rearrangement and organisation, whereas in db/db mice the impairment in steroidogenesis and secretory activity.

Calorie Restriction Using High-Fat/Low-Carbohydrate Diet Suppresses Liver Fat Accumulation and Pancreatic Beta-Cell Dedifferentiation in Obese Diabetic Mice.

In diabetes, pancreatic ß-cells gradually lose their ability to secrete insulin with disease progression. ß-cell dysfunction is a contributing factor to diabetes severity. Recently, islet cell heterogeneity, exemplified by ß-cell dedifferentiation and identified in diabetic animals, has attracted attention as an underlying molecular mechanism of ß-cell dysfunction. Previously, we reported ß-cell dedifferentiation suppression by calorie restriction, not by reducing hyperglycemia using hypoglycemic agents (including sodium-glucose cotransporter inhibitors), in an obese diabetic mice model (db/db). Here, to explore further mechanisms of the effects of food intake on ß-cell function, db/db mice were fed either a high-carbohydrate/low-fat diet (db-HC) or a low-carbohydrate/high-fat diet (db-HF) using similar calorie restriction regimens. After one month of intervention, body weight reduced, and glucose intolerance improved to a similar extent in the db-HC and db-HF groups. However, ß-cell dedifferentiation did not improve in the db-HC group, and ß-cell mass compensatory increase occurred in this group. More prominent fat accumulation occurred in the db-HC group livers. The expression levels of genes related to lipid metabolism, mainly regulated by peroxisome proliferator-activated receptor α and γ, differed significantly between groups. In conclusion, the fat/carbohydrate ratio in food during calorie restriction in obese mice affected both liver lipid metabolism and ß-cell dedifferentiation.

Elucidating ascorbate and aldarate metabolism pathway characteristics via integration of untargeted metabolomics and transcriptomics of the kidney of high-fat diet-fed obese mice.

Obesity is a major independent risk factor for chronic kidney disease and can activate renal oxidative stress injury. Ascorbate and aldarate metabolism is an important carbohydrate metabolic pathway that protects cells from oxidative damage. However the effect of oxidative stress on this pathway is still unclear. Therefore, the primary objective of this study was to investigate the ascorbate and aldarate metabolism pathway in the kidneys of high-fat diet-fed obese mice and determine the effects of oxidative stress. Male C57BL/6J mice were fed on a high-fat diet for 12 weeks to induce obesity. Subsequently, non-targeted metabolomics profiling was used to identify metabolites in the kidney tissues of the obese mice, followed by RNA sequencing using transcriptomic methods. The integrated analysis of metabolomics and transcriptomics revealed the alterations in the ascorbate and aldarate metabolic pathway in the kidneys of these high-fat diet-fed obese mice. The high-fat diet-induced obesity resulted in notable changes, including thinning of the glomerular basement membrane, alterations in podocyte morphology, and an increase in oxidative stress. Metabolomics analysis revealed 649 metabolites in the positive-ion mode, and 470 metabolites in the negative-ion mode. Additionally, 659 differentially expressed genes (DEGs) were identified in the obese mice, of which 34 were upregulated and 625 downregulated. Integrated metabolomics and transcriptomics analyses revealed two DEGs and 13 differential metabolites in the ascorbate and aldarate metabolic pathway. The expression levels of ugt1a9 and ugt2b1 were downregulated, and the ascorbate level in kidney tissue of obese mice was reduced. Thus, renal oxidative stress injury induced by high-fat diet affects metabolic regulation of ascorbate and aldarate metabolism in obese mice. Ascorbate emerged as a potential marker for predicting kidney damage due to high-fat diet-induced obesity.

Effects of repeated weight cycling on non-alcoholic steatohepatitis in diet-induced obese mice.

Lifestyle interventions remain the treatment of choice for patients with obesity and metabolic complications, yet are difficult to maintain and often lead to cycles of weight loss and regain (weight cycling). Literature on weight cycling remains controversial and we therefore investigated the association between weight cycling and metabolic complications using preexistent obese mice. Ldlr-/-.Leiden mice received a high-fat diet (HFD) for 20 weeks to induce obesity. Subsequently, weight-cycled mice were switched between the healthy chow diet and HFD for four 2-week periods and compared to mice that received HFD for the total study period. Repeated weight cycling tended to decrease body weight and significantly reduced fat mass, whereas adipose tissue inflammation was similar relative to HFD controls. Weight cycling did not significantly affect blood glucose or plasma insulin levels yet significantly reduced plasma free fatty acid and alanine transaminase/aspartate transaminase levels. Hepatic macrovesicular steatosis was similar and microvesicular steatosis tended to be increased upon weight cycling. Weight cycling resulted in a robust decrease in hepatic inflammation compared to HFD controls while hepatic fibrosis and atherosclerosis development were not affected. These results argue against the postulate that repeated weight cycling leads to unfavorable metabolic effects, when compared to a continuous unhealthy lifestyle, and in fact revealed beneficial effects on hepatic inflammation, an important hallmark of non-alcoholic steatohepatitis.

Fish Oil Improves Offspring Metabolic Health of Paternal Obese Mice by Targeting Adipose Tissue.

Obesity is a fast-growing epidemic affecting more than 40% of the US population and leads to co-morbidities such as type 2 diabetes and cancer. More importantly, there is a rapid increase in childhood obesity associated with obesity in parents. Further, offspring are encoded with approximately half of their genetic information from the paternal side. Obesity in fathers at the preconceptional period likely influences the intergenerational development of obesity. This study focuses on the role of fish oil supplementation as a non-pharmacological intervention in fathers and its impact on childhood obesity using animal models. Male mice were fed a low-fat diet or high-fat diet with or without fish oil for 10 weeks and mated with female mice on a chow diet. Offspring were then continued on a chow diet until 8 or 16 weeks. In vivo insulin tolerance was tested to assess the metabolic health of offspring. Further, adipose tissue was harvested upon sacrifice, and genetic markers of inflammation and lipid metabolism in the tissue were analyzed. Offspring of males supplemented with fish oil showed lower body weight, improved insulin tolerance, and altered inflammatory markers. Markers of fatty acid oxidation were higher, while markers of fatty acid synthesis were lower in offspring of fathers fed fish oil. This supports fish oil as an accessible intervention to improve offspring metabolic health.

Enhanced Metabolic Effects of Fish Oil When Combined with Vitamin D in Diet-Induced Obese Male Mice.

Vitamin D (vit D) and fish oil (FO) both offer unique health benefits, however, their combined effects have not been evaluated in obesity and nonalcoholic fatty liver disease (NAFLD). Hence, we hypothesized that vit D and FO supplementation would have additive effects in reducing obesity-associated inflammation and NAFLD. Male C57BL6 mice were split into four groups and fed a high fat (HF) diet supplemented with a low (HF; +200 IU vit D) or high dose of vitamin D (HF + D; +1000 IU vit D); combination of vit D and FO (HF-FO; +1000 IU vit D); or only FO (HF-FO; +200 IU vit D) for 12 weeks. We measured body weight, food intake, glucose tolerance, and harvested epididymal fat pad and liver for gene expression analyses. Adiposity was reduced in groups supplemented with both FO and vit D. Glucose clearance was higher in FO-supplemented groups compared to mice fed HF. In adipose tissue, markers of fatty acid synthesis and oxidation were comparable in groups that received vit D and FO individually in comparison to HF. However, the vit D and FO group had significantly lower fatty acid synthesis and higher oxidation compared to the other groups. Vit D and FO also significantly improved fatty acid oxidation, despite similar fatty acid synthesis among the four groups in liver. Even though we did not find additive effects of vit D and FO, our data provide evidence that FO reduces markers of obesity in the presence of adequate levels of vit D.

Single cell tracing of Pomc neurons reveals recruitment of 'Ghost' subtypes with atypical identity in a mouse model of obesity.

The hypothalamus contains a remarkable diversity of neurons that orchestrate behavioural and metabolic outputs in a highly plastic manner. Neuronal diversity is key to enabling hypothalamic functions and, according to the neuroscience dogma, it is predetermined during embryonic life. Here, by combining lineage tracing of hypothalamic pro-opiomelanocortin (Pomc) neurons with single-cell profiling approaches in adult male mice, we uncovered subpopulations of 'Ghost' neurons endowed with atypical molecular and functional identity. Compared to 'classical' Pomc neurons, Ghost neurons exhibit negligible Pomc expression and are 'invisible' to available neuroanatomical approaches and promoter-based reporter mice for studying Pomc biology. Ghost neuron numbers augment in diet-induced obese mice, independent of neurogenesis or cell death, but weight loss can reverse this shift. Our work challenges the notion of fixed, developmentally programmed neuronal identities in the mature hypothalamus and highlight the ability of specialised neurons to reversibly adapt their functional identity to adult-onset obesogenic stimuli.

[Genistein loaded by PRF improved bone healing in obese mice].

PURPOSE: To clarify the effect of genistein(GEN) on osteogenic differentiation and explore the effect of GEN loaded by platelet-rich fibrin (PRF) on the repair process of bone defects in obese mice. METHODS: In in vitro experiments, the effect of GEN(0, 0.1, 1, 10, 50 µmol/L) on the proliferation of mouse embryonic osteoblast precursor cells (MC3T3-E1) was determined by CCK 8. Alkaline phosphatase(ALP) staining and quantitative detection of ALP activity were performed to determine the changes of ALP activity in cells; RNA and protein expression levels of ALP, osteopontin (OPN) and osteocalcin (OCN) were detected by quantitative real-time PCR(qRT-PCR) and Western blot. Alizarin red staining was used to define the effect of GEN on mineralization of MC3T3-E1. To verify the feasibility of the PRF drug loading, the ultrastructure of PRF was subsequently observed under SEM. In in vivo experiments, obese C57 mouse models were established by high-fat diet feeding. On this basis, skull defect models with a diameter of 2.8 mm were established, and the prepared GEN/PRF complexes were placed into the bone defect area. The effects of GEN on skull defect repair in obese mice were evaluated by Micro-CT scanning and hematoxylin-eosin(H-E) staining. Statistical analysis was performed with GraphPad Prism 5.0 software package. RESULTS: CCK 8 results showed that 0.1, 1 µmol/L GEN promoted cell proliferation within 7 days(P＜0.05); 10 µmol/L GEN had no significant effect on the process of cell proliferation. From the second day, 50 µmol/L GEN significantly inhibited cell growth and showed cytotoxicity(P＜0.05). These two concentrations had similar effects in promoting cellular osteogenic differentiation. SEM results showed that PRF presented a 3-dimensional network structure, providing space for loading drug molecules. In in vivo experiments, the body weight of mice in the high-fat diet (HFD) group was 27.7% greater than that in the normal diet group(P＜0.05) and had abnormal glucose tolerance (P＜0.05). Micro-CT showed that compared with the normal diet group, the number of bone trabeculae in the femur of obese mice was decreased(P＜0.05), the distance between bone trabeculae was widened(P＜0.05), and the bone density was decreased (P＜0.05). In addition, GEN (0.1, 1.0 µmol/L) loaded by PRF increased bone volume fraction in the skull of obese mice (P＜0.05). H-E results showed that GEN/PRF promoted the healing of the bone defects. CONCLUSIONS: GEN promotes osteogenic differentiation of MC3T3-E1, and it can effectively accelerate the healing of cranial bone defects after loading with PRF in obese mice.

Lactate transporter MCT1 in hepatic stellate cells promotes fibrotic collagen expression in nonalcoholic steatohepatitis.

Circulating lactate is a fuel source for liver metabolism but may exacerbate metabolic diseases such as nonalcoholic steatohepatitis (NASH). Indeed, haploinsufficiency of lactate transporter monocarboxylate transporter 1 (MCT1) in mice reportedly promotes resistance to hepatic steatosis and inflammation. Here, we used adeno-associated virus (AAV) vectors to deliver thyroxin binding globulin (TBG)-Cre or lecithin-retinol acyltransferase (Lrat)-Cre to MCT1fl/fl mice on a choline-deficient, high-fat NASH diet to deplete hepatocyte or stellate cell MCT1, respectively. Stellate cell MCT1KO (AAV-Lrat-Cre) attenuated liver type 1 collagen protein expression and caused a downward trend in trichrome staining. MCT1 depletion in cultured human LX2 stellate cells also diminished collagen 1 protein expression. Tetra-ethylenglycol-cholesterol (Chol)-conjugated siRNAs, which enter all hepatic cell types, and hepatocyte-selective tri-N-acetyl galactosamine (GN)-conjugated siRNAs were then used to evaluate MCT1 function in a genetically obese NASH mouse model. MCT1 silencing by Chol-siRNA decreased liver collagen 1 levels, while hepatocyte-selective MCT1 depletion by AAV-TBG-Cre or by GN-siRNA unexpectedly increased collagen 1 and total fibrosis without effect on triglyceride accumulation. These findings demonstrate that stellate cell lactate transporter MCT1 significantly contributes to liver fibrosis through increased collagen 1 protein expression in vitro and in vivo, while hepatocyte MCT1 appears not to be an attractive therapeutic target for NASH.

Bcat2-Mediated Branched-Chain Amino Acid Catabolism Is Linked to the Aggravated Inflammation in Obese with Psoriasis Mice.

SCOPE: The global prevalence of obesity has significantly increased, presenting a major health challenge. High-fat diet (HFD)-induced obesity is closely related to the disease severity of psoriasis, but the mechanism is not fully understood. METHODS AND RESULTS: The study utilizes the HFD-induced obesity model along with an imiquimod (IMQ)-induced psoriasis-like mouse model (HFD-IMQ) to conduct transcriptomics and metabolomic analyses. HFD-induced obese mice exhibits more severe psoriasis-like lesions compared to normal diet (ND)-IMQ mice. The expression of genes of the IL-17 signaling pathway (IL-17A, IL-17F, S100A9, CCL20, CXCL1) is significantly upregulated, leading to an accumulation of T cells and neutrophils in the skin. Moreover, the study finds that there is an inhibition of the branched-chain amino acids (BCAAs) catabolism pathway, and the key gene branched-chain amino transferase 2 (Bcat2) is significantly downregulated, and the levels of leucine, isoleucine, and valine are elevated in the HFD-IMQ mice. Furthermore, the study finds that the peroxisome proliferator-activated receptor gamma (PPAR γ) is inhibited, while STAT3 activity is promoted in HFD-IMQ mice. CONCLUSION: HFD-induced obesity significantly amplifies IL-17 signaling and exacerbates psoriasis, with a potential role played by Bcat2-mediated BCAAs metabolism. The study suggests that BCAA catabolism and PPAR γ-STAT3 exacerbate inflammation in psoriasis with obesity.