Target For Treatment Of Obesity Research Articles

Computational insights into human UCP1 activators through molecular docking, MM-GBSA, and molecular dynamics simulation studies

The prevalence of obesity is rapidly increasing worldwide. Brown adipose tissue activates uncoupling protein 1 (UCP1) to generate heat through bypassing ATP synthesis, offering a potential target for obesity treatment. Targeting UCP1 activation to induce thermogenesis through small molecules presents a promising approach for obesity management. In this study, molecular docking of UCP1 activators, using 2,4-dinitrophenol (DNP) as a reference ligand (PDB ID: 8J1N, docking score: −5.343 kcal/mol), identified seven top-scoring compounds: naringin (-7.284 kcal/mol), quercetin (-6.661 kcal/mol), salsalate (-6.017 kcal/mol), rhein (-5.798 kcal/mol), mirabegron (-5.535 kcal/mol), curcumin (-5.479 kcal/mol), and formoterol (-5.451 kcal/mol). Prime MM-GBSA calculation of the top-scored molecule (i.e., naringin) in the docking study showed ΔGBind of −70.48 kcal/mol. Key interactions of these top 7 activators with UCP1 binding pocket residues Trp280, Arg276, Glu190, Arg83, and Arg91 were observed. Molecular dynamics simulations performed for 100 ns confirmed complex stability, with RMSD values below 6 Å. Additionally, most activators showed favorable intestinal absorption (>90 %) and lipophilicity (LogP 2–4), with pKa values supporting their pharmacological potential as UCP1-targeting therapeutics for obesity. These findings provide a foundation for designing potent UCP1 activators by integrating docking scores, interaction profiles, statistical profiles from MD simulations, and physicochemical assessments to develop effective anti-obesity therapies.

8638 NEGR1 is a Mediator of Exercise-Induced Neuritogenesis in Subcutaneous White Adipose Tissue, Implications for Improved Systemic Metabolism

Abstract Disclosure: P. Nigro: None. N.P. Carbone: None. T. Caputo: None. M. Vamvini: None. M.M. Columbus: None. M.F. Hirshman: None. R. Middelbeek: None. L.J. Goodyear: None. Emerging research shows that exercise training results in robust and beneficial adaptions to subcutaneous white adipose tissue (scWAT), leading to improved systemic metabolism. The mechanisms for these benefits of exercise on are not fully understood, but we have recently demonstrated that training in mouse scWAT refines nerve connections in scWAT promoting neurite outgrowth (neuritogenesis). Our multi-omics and advanced microscopy data identifies Neuronal Growth Regulator 1 (NEGR1) as a potential player in this process. Here, we determine the role of NEGR1 as a mediator of scWAT neuritogenesis and regulator of systemic metabolism. Exercise training in mice for 11 days significantly increased NEGR1 protein expression by 35% (p<0.05). Next, we directly injected NEGR1 AAV into the inguinal scWAT of untrained male mice for three weeks resulting in a 43% increase in NEGR1 protein (p<0.05). Overexpression of NEGR1 led to an increase in the innervation markers tyrosine hydroxylase (+38%, p<0.01) and synaptophysin (+39%, p<0.01), and remarkably, a 16% decrease in adipocyte cell size (p<0.05), and a 15% reduction in fasting blood glucose levels (p<0.05). This suggests that NEGR1 plays a fundamental role in regulating scWAT morphology and function, adaptations that improve systemic glucose homeostasis. To determine mechanisms for exercise training-induced increases in NEGR1 expression, we used in silico and cell culture experiments and found that NEGR1 is under the regulation of the Peroxisome Proliferator-Activated Receptor gamma (PPARg) transcription factor. Given that numerous natural and synthetic PPARg ligands are lipids, we used targeted lipidomics to identify exercise-induced lipids capable of binding and inducing PPARg expression in inguinal scWAT. We identified 13-oxo-octadecadienoic acid (13-oxo-ODE), an oxylipin derived from linoleic acid, as a potent agonist and inducer of PPARg expression. Exercise training increased 13-oxo-ODE by 3-fold (p<0.05), and 13-hydroxyoctadecadienoic acid (13-HODE), the 13-oxo-ODE precursor was also increased by 3-fold (p<0.01). To validate that 13-oxo-ODE increases NEGR1, adipocytes were incubated with 2μM of 13-oxo-ODE for 48 hours. 13-oxo-ODE increased NEGR1 expression by 27-fold (p<0.0001) and NEGR1 protein by 2-fold (p<0.01). In summary, NEGR1 is a novel exercise-induced molecule that regulates neuronal refinement in scWAT. Our data also suggest that the synthesis of 13-oxo-ODE leads to PPARγ activation that in turn promotes NEGR1 expression in scWAT. NEGR1 has beneficial effects on scWAT that are associated with improved systemic metabolism, making NEGR1 a novel target for treatment of obesity and cardiometabolic diseases. Presentation: 6/1/2024

Orexins mitigate obesity-associated dysfunctions in mice.

Obesity is a chronic disease that affects more than 400 million adults with severe comorbidities. The search for new treatments to reduce its negative consequences is necessary. Orexins are hypothalamic neuropeptides involved in various physiological processes related to obesity. The aim of this study was to investigate the consequences of chronic orexin-A treatment in mouse models. Female wild-type C57BL/6 mice that were obesity-prone or obesity-resistant and mice that were deficient for orexin receptors were fed with a high-fat diet. Glucose tolerance, indirect calorimetry, expression of brain neuropeptides and receptors, microglial activation, and microbiota were determined to evaluate the role of orexins on metabolic flexibility. Orexin-A reduces weight gain in obesity-prone mice. This reduction is associated with a decrease in body fat, food intake, steatosis, and insulin resistance, as well as alterations of intestinal microbiota composition. A decreased expression of orexin receptors and neuropeptides involved in food intake was also observed in the hypothalamus. Our data support the notion that orexin receptor signaling is involved in different aspects of energy metabolism and can mitigate several dysfunctions associated with obesity, suggesting that orexin receptors can represent new targets for obesity treatment.

Fatty acids promote uncoupled respiration via the ATP/ADP carrier in white adipocytes.

Adipocytes store energy as triglycerides, while mobilizing energy when needed via lipolysis. Triglyceride lipolysis releases fatty acids and glycerol into the circulation to fuel other tissues. However, a significant fraction of fatty acids released by lipolysis are retained within the white adipose tissue and handled by adipocytes. While some of these retained fatty acids are re-esterified in white adipocytes 1-6 , the a substantial amount undergo oxidative metabolism via a pathway regulated by the nongenomic effects of STAT3 7-10 . Here we report that fatty acids promote uncoupled oxidative metabolism in white adipocytes via the ATP/ADP carrier, contributing to thermogenesis and cold tolerance in obese thermoneutral-adapted mice, independent of brown adipose tissue and muscle activity. Our results suggest that uncoupled respiration in white adipocytes significantly contributes to whole-body energy expenditure and could be a promising target for obesity treatment.

Weighing in on the role of brown adipose tissue for treatment of obesity.

Brown adipose tissue (BAT) activation is an emerging target for obesity treatments due to its thermogenic properties stemming from its ability to shuttle energy through uncoupling protein 1 (Ucp1). Recent rodent studies show how BAT and white adipose tissue (WAT) activity can be modulated to increase the expression of thermogenic proteins. Consequently, these alterations enable organisms to endure cold-temperatures and elevate energy expenditure, thereby promoting weight loss. In humans, BAT is less abundant in obese subjects and impacts of thermogenesis are less pronounced, bringing into question whether energy expending properties of BAT seen in rodents can be translated to human models. Our review will discuss pharmacological, hormonal, bioactive, sex-specific and environmental activators and inhibitors of BAT to determine the potential for BAT to act as a therapeutic strategy. We aim to address the feasibility of utilizing BAT modulators for weight reduction in obese individuals, as recent studies suggest that BAT's contributions to energy expenditure along with Ucp1-dependent and -independent pathways may or may not rectify energy imbalance characteristic of obesity.

Activation of GFRAL+ neurons induces hypothermia and glucoregulatory responses associated with nausea and torpor

GFRAL-expressing neurons actuate aversion and nausea, are targets for obesity treatment, and may mediate metformin effects by long-term GDF15-GFRAL agonism. Whether GFRAL+ neurons acutely regulate glucose and energy homeostasis is, however, underexplored. Here, we report that cell-specific activation of GFRAL+ neurons using a variety of techniques causes a torpor-like state, including hypothermia, the release of stress hormones, a shift from glucose to lipid oxidation, and impaired insulin sensitivity, glucose tolerance, and skeletal muscle glucose uptake but augmented glucose uptake in visceral fat. Metabolomic analysis of blood and transcriptomics of muscle and fat indicate alterations in ketogenesis, insulin signaling, adipose tissue differentiation and mitogenesis, and energy fluxes. Our findings indicate that acute GFRAL+ neuron activation induces endocrine and gluco- and thermoregulatory responses associated with nausea and torpor. While chronic activation of GFRAL signaling promotes weight loss in obesity, these results show that acute activation of GFRAL+ neurons causes hypothermia and hyperglycemia.

New mechanistic insights of anti-obesity by sleeve gastrectomy-altered gut microbiota and lipid metabolism.

The obesity epidemic has been on the rise due to changes in living standards and lifestyles. To combat this issue, sleeve gastrectomy (SG) has emerged as a prominent bariatric surgery technique, offering substantial weight reduction. Nevertheless, the mechanisms that underlie SG-related bodyweight loss are not fully understood. In this study, we conducted a collection of preoperative and 3-month postoperative serum and fecal samples from patients who underwent laparoscopic SG at the First Affiliated Hospital of Shandong First Medical University (Jinan, China). Here, we took an unbiased approach of multi-omics to investigate the role of SG-altered gut microbiota in anti-obesity of these patients. Non-target metabolome sequencing was performed using the fecal and serum samples. Our data show that SG markedly increased microbiota diversity and Rikenellaceae, Alistipes, Parabacteroides, Bactreoidales, and Enterobacteraies robustly increased. These compositional changes were positively correlated with lipid metabolites, including sphingolipids, glycerophospholipids, and unsaturated fatty acids. Increases of Rikenellaceae, Alistipes, and Parabacteroide were reversely correlated with body mass index (BMI). In conclusion, our findings provide evidence that SG induces significant alterations in the abundances of Rikenellaceae, Alistipes, Parabacteroides, and Bacteroidales, as well as changes in lipid metabolism-related metabolites. Importantly, these changes were found to be closely linked to the alleviation of obesity. On the basis of these findings, we have identified a number of microbiotas that could be potential targets for treatment of obesity.

Neural adaption in midbrain GABAergic cells contributes to high-fat diet-induced obesity.

Overeating disorders largely contribute to worldwide incidences of obesity. Available treatments are limited. Here, we discovered that long-term chemogenetic activation of ventrolateral periaqueductal gray (vlPAG) GABAergic cells rescue obesity of high-fat diet-induced obesity (DIO) mice. This was associated with the recovery of enhanced mIPSCs, decreased food intake, increased energy expenditure, and inguinal white adipose tissue (iWAT) browning. In vivo calcium imaging confirmed vlPAG GABAergic suppression for DIO mice, with corresponding reduction in intrinsic excitability. Single-nucleus RNA sequencing identified transcriptional expression changes in GABAergic cell subtypes in DIO mice, highlighting Cacna2d1 as of potential importance. Overexpressing CACNA2D1 in vlPAG GABAergic cells of DIO mice rescued enhanced mIPSCs and calcium response, reversed obesity, and therefore presented here as a potential target for obesity treatment.

PPARα/γ synergism activates UCP1-dependent and -independent thermogenesis and improves mitochondrial dynamics in the beige adipocytes of high-fat fed mice

ObjectiveThe aim of this study was to investigate the role of peroxisome proliferator-activated receptor (PPAR) activation (single PPARα or PPARγ, and dual PPARα/γ) on UCP1-dependent and -independent thermogenic pathways and mitochondrial metabolism in the subcutaneous white adipose tissue of mice fed a high-fat diet. MethodsMale C57BL/6 mice received either a control diet (10% lipids) or a high-fat diet (HF; 50% lipids) for 12 wk. The HF group was divided to receive the treatments for 4 wk: HFγ (pioglitazone, 10 mg/kg), HFα (WY-14643, 3.5 mg/kg), and HFα/γ (tesaglitazar, 4 mg/kg). ResultsThe HF group was overweight, insulin resistant, and had subcutaneous white adipocyte dysfunction. Treatment with PPARα and PPARα/γ reduced body mass, mitigated insulin resistance, and induced browning with increased UCP1-dependent and -independent thermogenesis activation and improved mitochondrial metabolism to support the beige adipocyte phenotype. ConclusionPPARα and dual PPARα/γ activation recruited UCP1+ beige adipocytes and favored UCP1-independent thermogenesis, yielding body mass and insulin sensitivity normalization. Preserved mitochondrial metabolism emerges as a potential target for obesity treatment using PPAR agonists, with possible clinical applications.

Conventional and genetic associations of adiposity with 1463 proteins in relatively lean Chinese adults

Adiposity is associated with multiple diseases and traits, but little is known about the causal relevance and mechanisms underlying these associations. Large-scale proteomic profiling, especially when integrated with genetic data, can clarify mechanisms linking adiposity with disease outcomes. We examined the associations of adiposity with plasma levels of 1463 proteins in 3977 Chinese adults, using measured and genetically-instrumented BMI. We further used two-sample bi-directional MR analyses to assess if certain proteins influenced adiposity, along with other (e.g. enrichment) analyses to clarify possible mechanisms underlying the observed associations. Overall, the mean (SD) baseline BMI was 23.9 (3.3) kg/m2, with only 6% being obese (i.e. BMI ≥ 30 kg/m2). Measured and genetically-instrumented BMI was significantly associated at FDR < 0.05 with levels of 1096 (positive/inverse: 826/270) and 307 (positive/inverse: 270/37) proteins, respectively, with FABP4, LEP, IL1RN, LSP1, GOLM2, TNFRSF6B, and ADAMTS15 showing the strongest positive and PON3, NCAN, LEPR, IGFBP2 and MOG showing the strongest inverse genetic associations. These associations were largely linear, in adiposity-to-protein direction, and replicated (> 90%) in Europeans of UKB (mean BMI 27.4 kg/m2). Enrichment analyses of the top > 50 BMI-associated proteins demonstrated their involvement in atherosclerosis, lipid metabolism, tumour progression and inflammation. Two-sample bi-directional MR analyses using cis-pQTLs identified in CKB GWAS found eight proteins (ITIH3, LRP11, SCAMP3, NUDT5, OGN, EFEMP1, TXNDC15, PRDX6) significantly affect levels of BMI, with NUDT5 also showing bi-directional association. The findings among relatively lean Chinese adults identified novel pathways by which adiposity may increase disease risks and novel potential targets for treatment of obesity and obesity-related diseases.

Acetyl-coenzyme A acetyltransferase 1 promotes brown adipogenesis by activating the AMPK-PGC1α signaling pathway

Brown adipose tissue (BAT) is thermogenic, expressing high levels of uncoupling protein-1 to convert nutrient energy to heat energy, bypassing ATP synthesis. BAT is a promising therapeutic target for treatment of obesity and type 2 diabetes since it converts fatty acids into heat but mechanisms controlling brown adipogenesis remain unclear. Knockdown of acetyl-Coenzyme A acetyltransferase 1 (ACAT1) in C3H10T1/2 cells suppressed brown adipocyte maturation during the current study and ACAT1 overexpression promoted brown adipocyte maturation. The downstream target of AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma coactivator-1-α (PGC1α), was involved in the action of ACAT1 on brown adipocyte maturation. ACAT1 overexpression enhanced AMPK phosphorylation and promoted PGC1α expression. It is suggested that ACAT1 promotes brown adipocyte maturation by activating the AMPK-PGC1α signaling pathway.

Changes in plasma endocannabinoids concentrations correlate with 18F-FDG PET/MR uptake in brown adipocytes in humans.

Introduction: Recent data suggest a possible role of endocannabinoids in the regulation of brown adipose tissue (BAT) activity. Those findings indicate potential treatment options for obesity. The aim of this study was to evaluate the relationship between plasma endocannabinoids concentrations and the presence of BAT in humans. Methods: The study group consisted of 25 subjects divided into two groups: BAT positive BAT(+), (n = 17, median age = 25years) and BAT negative BAT(-), (n = 8, median age = 28years). BAT was estimated using 18F-FDG PET/MR after 2h of cold exposure. The level of plasma endocannabinoids was assessed at baseline, 60min and 120min of cold exposure. Results: In both groups, BAT(+) and BAT(-), during the cooling, we observed a decrease of the same endocannabinoids: arachidonoylethanolamide (AEA), eicosapentaenoyl ethanolamide (EPEA) and oleoyl ethanolamide (OEA) with a much more profound decline in BAT(+) subjects. Statistically significant fall of PEA (palmitoylethanolamide) and SEA (stearoylethanolamide) concentrations after 60min (FC = 0.7, p = 0.007 and FC = 0.8, p = 0.03, respectively) and 120min (FC = 0.81, p = 0.004, and FC = 0.9, p = 0.01, respectively) of cooling was observed only in individuals with BAT. Conclusion: We noticed the profound decline of endocannabinoids concentrations in subjects with increased 18F-FDG PET/MR uptake in BAT. Identification of a new molecules related to BAT activity may create a new target for obesity treatment.

Gamma-Aminobutyric Acid Promotes Beige Adipocyte Reconstruction by Modulating the Gut Microbiota in Obese Mice.

Given the increasing prevalence of obesity, the white-to-beige adipocyte conversion has attracted interest as a target for obesity treatment. Gamma-aminobutyric acid (GABA) treatment can reduce obesity, but the underlying mechanism remains unclear. Here, we aimed to investigate the mechanism by which GABA triggers weight loss by improving the beiging of inguinal white adipose tissue (iWAT) and the role of gut microbiota in this process. The results showed that GABA reduced body weight and adipose inflammation and promoted the expression of thermogenic genes in the iWAT. The 16S rRNA sequence analysis of gut microbiota showed that GABA treatment increased the relative abundance of Bacteroidetes, Akkermansia, and Romboutsia and reduced that of Firmicutes and Erysipelatoclostridium in obese mice. Additionally, serum metabolomic analysis revealed that GABA treatment increased 3-hydroxybutyrate and reduced oxidized lipid levels in obese mice. Spearman's correlation analysis showed that Akkermansia and Romboutsia were negatively associated with the levels of oxidized lipids. Fecal microbiota transplantation analysis confirmed that the gut microbiota was involved in the white-to-beige adipocyte reconstruction by GABA. Overall, our findings suggest that GABA treatment may promote iWAT beiging through the gut microbiota in obese mice. GABA may be utilized to protect obese people against metabolic abnormalities brought on by obesity and gut dysbiosis.

Obesity is associated with IL-6 gene polymorphisms rs1800795 and rs1800796 but not SOCS3 rs4969170.

An imbalance of inflammatory factors can stimulate obesity by inducing chronic inflammation in adipose tissue. Interleukin-6 (IL-6) is a cytokine with both inflammatory and anti-inflammatory functions. Suppressor of cytokine signaling 3 (SOCS3) acts as an inhibitor for a number of cytokine signals. The IL-6 and SOCS3 genes are known to be involved in lipid and energy metabolism, although it is unclear how these genes relate to obesity. The aim of this study is to determine whether the obesity risk is associated with the IL-6 (rs1800795, rs1800796) and SOCS3 (rs4969170) gene polymorphisms. Based on their body mass index (BMI) scores, 185 people were determined, of whom 90 were from the control group and 95 were obese. Anthropometric measurements and biochemical parameters of the study subjects were documented during the examination. Genomic DNA isolation was performed from the blood samples of all participants. IL-6 (rs1800795, rs1800796) and SOCS3 (rs4969170) polymorphisms were detected by real-time quantitative polymerase chain reaction (qRT-PCR) from genomic DNA samples. The IL-6 rs1800795 and rs1800796 variants showed a significant difference between the control and obese groups (p = 0.027; p = 0.013). The SOCS3 rs4969170 variation did not substantially differ between the control and obese groups (p = 0.825). In our study, IL-6 rs1800795(G/C) and rs1800796(G/C) polymorphisms appeared to be a risk factor for obesity. The C allele was associated with the obesity phenotypes. However, the SOCS3 rs4969170 (A/G) polymorphism was not linked to an increased risk of obesity. IL-6 polymorphisms may be new targets for obesity treatment.

Lipase activity inhibited by aloenin A: Glycoside from Aloe vera (L.) Burm. f.-In vitro and molecular docking studies.

Obesity is taking over many parts of the world and has been identified as the second leading cause of preventable death, with a dramatic increase in prevalence over the last two decades. Pancreatic lipase is a lipid-digesting enzyme that plays an important role in fat metabolism. Inhibiting pancreatic lipase is an attractive target for obesity treatment. Phytochemicals or bioactive compounds/extracts isolated from medicinal plants offer a promising platform for the development of pancreatic lipase inhibitors. This study aims to characterize and investigate the effect of aloenin A, glycoside found in Aloe vera, as a possible inhibitor of pancreatic lipase in vitro and in silico. A. vera extract had an IC50 value of 0.5472 μg/ml, whereas aloenin A had an IC50 value of 14.95 μg/mL and was found to inhibit in a competitive manner. These findings were supported by molecular docking studies, which revealed that aloenin A binds to the substrate binding site with a binding energy of - 7.16 kcal/mol, and this binding site is stabilized by three hydrogen bonds contributed by Phe77 and Asp79 . Our findings suggest that the anti-hyperlipidemic effects of A. vera on pancreatic lipase can be attributed in part to the presence of aloenin A.

Chronic cAMP activation induces adipocyte browning through discordant biphasic remodeling of transcriptome and chromatin accessibility

ObjectiveAdipose tissue thermogenesis has been suggested as a new therapeutic target to promote energy metabolism for obesity and metabolic disease. Cold-inducible thermogenic adipocytes, called beige adipocytes, have attracted significant attention for their potent anti-obesity activity in adult humans. In this study, we identified the mechanisms underlying beige adipocyte recruitment, so-called adipocyte browning, by different stimuli. MethodsWe generated a new adipocyte cell line with enhanced browning potentials and determined its transcriptomic and epigenomic responses following cAMP (forskolin, FSK) versus PPARγ activation (rosiglitazone). We performed time-course RNA-seq and compared the treatments and in vivo adipocyte browning. We also developed an improved protocol for Assay for Transposase Accessible Chromatin-sequencing (ATAC-seq) and defined changes in chromatin accessibility in a time course. The RNA-seq and ATAC-seq data were integrated to determine the kinetics of their coordinated regulation and to identify a transcription factor that drives these processes. We conducted functional studies using pharmacological and genetic approaches with specific inhibitors and shRNA-mediated knockdown, respectively. ResultsFSK, not rosiglitazone, resulted in a biphasic transcriptomic response, resembling the kinetics of in vivo cold-induced browning. FSK promoted tissue remodeling first and subsequently shifted energy metabolism, concluding with a transcriptomic profile similar to that induced by rosiglitazone. The thermogenic effects of FSK were abolished by PPARγ antagonists, indicating PPARγ as a converging point. ATAC-seq uncovered that FSK leads to a significant chromatin remodeling that precedes or persists beyond transcriptomic changes, whereas rosiglitazone induces minimal changes. Motif analysis identified nuclear factor, interleukin 3 regulated (NFIL3) as a transcriptional regulator connecting the biphasic response of FSK-induced browning, as indicated by disrupted thermogenesis with NFIL3 knockdown. ConclusionsOur findings elucidated unique dynamics of the transcriptomic and epigenomic remodeling in adipocyte browning, providing new mechanistic insights into adipose thermogenesis and molecular targets for obesity treatment.

MC4R biased signalling and the conformational basis of biological function selections.

The MC4R, a GPCR, has long been a major target for obesity treatment. As the most well‐studied melanocortin receptor subtype, the evolutionary knowledge pushes the drug development and structure–activity relationship (SAR) moving forward. The past decades have witnessed the evolution of scientists' view on GPCRs gradually from the control of a single canonical signalling pathway via a bilateral ‘active‐inactive’ model to a multi‐state alternative model where the ligands' binding affects the selection of the downstream signalling. This evolution brings the concept of biased signalling and the beginning of the next generation of peptide drug development, with the aim of turning from receptor subtype specificity to signalling pathway selectivity. The determination of the value structures of the MC4R revealed insights into the working mechanism of MC4R activation upon binding of agonists. However, new challenge has risen as we seek to unravel the mystery of MC4R signalling selection. Thus, more biased agonists and ligands with representative biological functions are needed to solve the rest of the puzzle.

Accreditation Council for Pharmacy Education: 2021 Annual Report

<h3>Background and Objectives</h3> Narcolepsy type 1 (NT1) is an orphan brain disorder caused by the irreversible destruction of orexin neurons. Metabolic disturbances are common in patients with NT1 who have a body mass index (BMI) 10% to 20% higher than the general population, with one-third being obese (BMI &gt;30 kg/m²). Besides the destruction of orexin neurons in NT1, the metabolic alterations in obese and nonobese patients with NT1 remain unknown. The aim of this study was to identify possible differences in plasma metabolic profiles between patients with NT1 and controls as a function of their BMI status. <h3>Methods</h3> We used a targeted liquid chromatography–mass spectrometry metabolomics approach to measure 141 circulating, low-molecular-weight metabolites in drug-free fasted plasma samples from 117 patients with NT1 (including 41 obese individuals) compared with 116 BMI-matched controls (including 57 obese individuals). <h3>Results</h3> Common metabolites driving the difference between patients with NT1 and controls, regardless of BMI, were identified, namely sarcosine, glutamate, nonaylcarnitine (C9), 5 long-chain lysophosphatidylcholine acyls, 1 sphingolipid, 12 phosphatidylcholine diacyls, and 11 phosphatidylcholine acyl-akyls, all showing increased concentrations in NT1. Metabolite concentrations significantly affected by NT1 (n = 42) and BMI category (n = 40) showed little overlap (n = 5). Quantitative enrichment analysis revealed common metabolic pathways that were implicated in the NT1/control differences in both normal BMI and obese comparisons, namely glycine and serine, arachidonic acid, and tryptophan metabolism. The metabolites driving these differences were glutamate, sarcosine, and ornithine (glycine and serine metabolism); glutamate and PC aa C34:4 (arachidonic acid metabolism); and glutamate, serotonin, and tryptophan (tryptophan metabolism). Linear metabolite-endophenotype regression analyses highlight that as part of the NT1 metabolic phenotype, most of the relationships between the sleep parameters (i.e., slow-wave sleep duration, sleep latency, and periodic leg movement) and metabolite concentrations seen in the controls were lost. <h3>Discussion</h3> These results represent the most comprehensive metabolic profiling of patients with NT1 as a function of BMI and propose some metabolic diagnostic biomarkers for NT1, namely glutamate, sarcosine, serotonin, tryptophan, nonaylcarnitine, and some phosphatidylcholines. The metabolic pathways identified offer, if confirmed, possible targets for treatment of obesity in NT1. <h3>Classification of Evidence</h3> This study provides Class II evidence that a distinct metabolic profile can differentiate patients with NT1 from patients without the disorder.

Role of Cyp2j6 in Brown Adipogenesis

ObjectivesBrown adipocytes are novel targets for obesity treatment and prevention. Cytochrome P-450 (CYP) epoxygenases, Cyp2j family members in particular, produce epoxy fatty acids (EpFAs), which are known to play important roles in regulating adipogenesis and obesity. However, the effects of Cyp2j6, the most abundant member of the Cyp2j family, on brown adipogenesis have not been reported. Here, we examined mRNA expression patterns of Cyp2j6 in brown vs. white adipogenesis and diet-induced obesity and investigated the impact of overexpression of Cyp2j6 on brown adipogenesis.Methods Cyp2j6 mRNA expression was examined in murine brown vs. white adipocyte differentiation and the brown (iBAT), epididymal (eWAT), and inguinal white adipose tissue (iWAT) of diet-induced obese mice. Moreover, murine brown pre-adipocytes were stably transfected with either Cyp2j6 or the vector control to investigate the effects of Cyp2j6 overexpression on brown adipogenesis.Results Cyp2j6 mRNA was significantly suppressed in differentiated brown adipocytes compared to brown pre-adipocytes. In contrast, Cyp2j6 mRNA was not changed in white adipocyte differentiation. Moreover, Cyp2j6 mRNA was elevated in iBAT, eWAT, and iWAT of diet-induced obese mice compared to the controls; however, only Cyp2j6 mRNA in the eWAT reached significance. Furthermore, Cyp2j6 overexpression significantly suppressed murine brown adipocyte differentiation as evaluated by lipid accumulation and brown markers’ expression.ConclusionsOur results suggest that Cyp2j6 may play an important role in brown adipogenesis. Further studies of Cyp2j6 in brown adipogenesis and BAT development in vivo are warranted.Funding SourcesThe work was supported by NIH.

A Novel PKCβ Inhibitor More Potent than Ruboxistaurin: Potential Therapeutic Tool for Obesity and Fatty Liver Disease

The ongoing epidemic of obesity and its associated comorbidities has increased the demand for novel therapeutics targeted toward modulating appetite and/or energy metabolism. The search for clinically useful drugs has thus far met with limited success, and therefore the identification of novel potential targets remains of great interest. We previously showed that mice with systemic PKCβ depletion displayed many of the features one would desire in individuals treated with an ideal antiobesity drug; increase in lean body mass and elevated metabolic rate contributing to prevention of diet‐induced adiposity, hepatic steatosis, and insulin resistance (Hepatology 49:1525, 2009; J. Lipid Res. 286:22795, 2011). Even depletion of hepatocyte‐specific PKCβ recapitulated many of the bebeficial features of whole‐body knockout mice (Mol. Metab. 44:e101133, 2021; JCI Insight 6:e149023, 2021). Our results provide compelling evidence that PKCβ is an important therapeutic target for treatment of obesity and related metabolic complications. An alternative strategy to genetic manipulation of PKCβ expression is the chronic use of selective inhibitors to resolve obesity, or reverse obesity, or both. About 25 years ago, it was reported that a small, orally available molecule, called ruboxistaurin, (also known as LY333,531) reported to potently and selectively inhibited PKCβ. This inhibitor displayed kinetics consistent with direct competition for ATP binding to PKCβ. This selectivity fueled several randomized clinical trials of ruboxstaurin to resolve chronic diabetic microvascular complications such as neuropathy, retinopathy, and macular oedema. Although the mechanism through which hyperglycemia results in vascular dysfunction has not been well established, but the in vivo and in vitro preclinical evidence suggested that hyperglycemia‐induced activation of PKCβ might underlie the development of these microvascular diseases into chronic diabetic complications. To the best of our knowledge, primary outcomes were never achieved in any of the trials and ruboxistaurin has not been approved from the U. S. Food and Drug Administration. Considering that targeting PKCβ outside of the conserved ATP site may be an effective strategy to achieve greater selectivity and potency, we hereby describe screening of already known and newly synthesized bisindolylmaleimides and their derivatives to evaluate whether these chemicals inhibit PKCβ with similar or higher potency than ruboxistaurin. These chemicals were also used to evaluate inhibition of PKCβ vs PKCα. We identified INST3399 as the most potent inhibitor of PKCβ in the basal state, being about 5‐times more potent than ruboxistaurin and more than 100‐fold selectivity for PKCβ versus PKCα. INST3399 is also several orders of magnitude more selective for inhibition of PKCβ in comparison to other ATP dependent kinases. INST3399 appears to inhibit PKCβ by a mechanism different from ruboxistaurin. As expected, INST3399 prevented diet‐induced obesity and hepatic steatosis. This has clear implications for the treatment of metabolic conditions with excessive PKCβ activity. Further studies are in progress to assess the therapeutic efficacy of this compound in reversing obesity.