JTP-103237, a monoacylglycerol acyltransferase inhibitor, prevents fatty liver and suppresses both triglyceride synthesis and de novo lipogenesis.

AIM: Monoacyglycerol acyltransferases (MGATs) are known to play important roles in intestinal TG absorption. In contrast, the role of MGATs in the liver is still unclear. We investigated the effects of JTP-103237, a novel MGAT inhibitor, on hepatic MGAT activity and hepatic lipid metabolism. RESULTS: JTP-103237 reduced hepatic triglyceride content and hepatic MGAT activity in a high sucrose very low fat (HSVLF) diet induced fatty liver model. Interestingly, JTP-103237 suppressed not only triglyceride (TG) and diacylglycerol (DG) synthesis, but also fatty acid (FA) synthesis (de novo lipogenesis) in this model. JTP-103237 also suppressed lipogenesis-related gene expression, such as sterol regulatory element-binding protein 1-c. Moreover, JTP-103237 decreased plasma glucose levels and total cholesterol and reduced the accumulation of epididymal fats in HSVLF diet fed mice. CONCLUSION: In the present study, JTP-103237 prevented carbohydrate-induced fatty liver and suppressed both TG synthesis and de novo lipogenesis, suggesting MGAT inhibitor may prevent carbohydrate-induced metabolic disorders, including NAFLD, obesity and diabetes.

The proximal intestinal Fatty Acid-Binding Proteins liver FABP (LFABP) and intestinal FABP (IFABP) differentially modulate whole body energy homeostasis but are not centrally involved in net dietary lipid absorption: Studies of the LFABP/IFABP double knockout mouse.

Proximal intestinal enterocytes expresses both intestinal-fatty acid binding protein (IFABP; FABP2) and liver-FABP (LFABP; FABP1). These FABPs are thought to be important in the net uptake of dietary lipid from the intestinal lumen, however their specific and potentially unique functions in the enterocyte remain incompletely understood. We previously showed markedly divergent phenotypes in LFABP-/- vs. IFABP-/- mice fed high-fat diets, with the former becoming obese and the latter remaining lean relative to wild-type (WT) mice, supporting different functional roles for each protein. Interestingly, neither mouse model displayed increased fecal lipid concentration, raising the question of whether the presence of one FABP was sufficient to compensate for absence of the other. Here, we generated an LFABP and IFABP double knockout mouse (DKO) to determine whether simultaneous ablation would lead to fat malabsorption, and to further interrogate the individual vs. overlapping functions of these proteins. Male WT, IFABP-/-, LFABP-/-, and DKO mice were fed a low-fat (10 % kcal) or high-fat (45 % kcal) diet for 12 weeks. The body weights and fat mass of the DKO mice integrated those of the LFABP-/- and IFABP-/- single knockouts, supporting the notion that IFABP and LFABP have distinct functions in intestinal lipid assimilation that result in downstream alterations in systemic energy metabolism. Remarkably, no differences in fecal fat concentrations were found in the DKO compared to WT, revealing that the FABPs are not required for net intestinal uptake of dietary lipid.

Metabolic dysregulation and emerging therapeutical targets for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is an aggressive human cancer with increasing incidence worldwide. Multiple efforts have been made to explore pharmaceutical therapies to treat HCC, such as targeted tyrosine kinase inhibitors, immune based therapies and combination of chemotherapy. However, limitations exist in current strategies including chemoresistance for instance. Tumor initiation and progression is driven by reprogramming of metabolism, in particular during HCC development. Recently, metabolic associated fatty liver disease (MAFLD), a reappraisal of new nomenclature for non-alcoholic fatty liver disease (NAFLD), indicates growing appreciation of metabolism in the pathogenesis of liver disease, including HCC, thereby suggesting new strategies by targeting abnormal metabolism for HCC treatment. In this review, we introduce directions by highlighting the metabolic targets in glucose, fatty acid, amino acid and glutamine metabolism, which are suitable for HCC pharmaceutical intervention. We also summarize and discuss current pharmaceutical agents and studies targeting deregulated metabolism during HCC treatment. Furthermore, opportunities and challenges in the discovery and development of HCC therapy targeting metabolism are discussed.

Systemic and spinal administration of FAAH, MAGL inhibitors and dual FAAH/MAGL inhibitors produce antipruritic effect in mice.

The increase of endocannabinoid tonus by inhibiting fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL) represents a promising therapeutic approach in a variety of disease to overcome serious central side effects of exocannabinoids. Recent studies reported that systemic administration of FAAH and MAGL inhibitors produce antipruritic action. Dual FAAH/MAGL inhibitors have also been described to get enhanced endocannabinoid therapeutic effect. In this study, we examined and compared dose-related antipruritic effects of systemic (intraperitoneal; ip) or intrathecal (it) administration of selective FAAH inhibitor PF-3845 (5, 10, and 20 mg/kg, i.p.; 1, 5, and 10 µg, i.t.), MAGL inhibitor JZL184 (4, 20, and 40 mg/kg, i.p.; 1, 5, and 10 µg, i.t.) and dual FAAH/MAGL inhibitor JZL195 (2, 5, and 20 mg/kg, i.p.; 1, 5, and 10 µg, i.t.) on serotonin (5-HT)-induced scratching model. Serotonin (25 µg) was injected intradermally in a volume of 50 µl into the rostral part of skin on the back of male Balb-C mice. Both systemic or intrathecal administration of PF-3845, JZL184 or JZL195 produced similar dose-dependent antipruritic effects. Our results suggest that endocannabinoid-degrading enzymes FAAH and MAGL are involved in pruritic process at spinal level. FAAH, MAGL or dual FAAH/MAGL inhibitors have promising antipruritic effects, at least, in part through spinal site of action.

Effect of pre-existing maternal obesity, gestational diabetes and adipokines on the expression of genes involved in lipid metabolism in adipose tissue.

OBJECTIVE: To determine the effect of maternal obesity, gestational diabetes mellitus (GDM) and adipokines on the expression of genes involved in fatty acid uptake, transport, synthesis and metabolism. MATERIALS/METHODS: Human subcutaneous and omental adipose tissues were obtained from lean, overweight and obese normal glucose tolerant (NGT) women and women with GDM. Quantitative RT-PCR (qRT-PCR) was performed to determine the level of expression. Adipose tissue explants were performed to determine the effect of the adipokines TNFα, IL-1ß and leptin on adipose tissue gene expression. RESULTS: Pre-existing maternal obesity and GDM are associated with decreased expression in genes involved in fatty acid uptake and intracellular transport (LPL, FATP2, FATP6, FABPpm and ASCL1), triacylglyceride (TAG) biosynthesis (MGAT1,7 MGAT2 and DGAT1), lipogenesis (FASN) and lipolysis (PNPLA2, HSL and MGLL). Decreased gene expression was also observed for the transcription factors involved in lipid metabolism (LXRα, PPARα, PPARδ, PPARγ, RXRα and SREBP1c). On the other hand, the gene expression of the adipokines TNFα, IL-1ß and or leptin was increased in adipose tissue from obese and GDM women. Functional in vitro studies revealed that these adipokines decreased the gene expression of LPL, FATP2, FATP6, ASCL1, PNPLA2, PPARδ, PPARγ and RXRα. CONCLUSIONS: Pregnancies complicated by pre-existing maternal obesity and GDM are associated with abnormal adipose tissue lipid metabolism, which may play a role in the pathogenesis of these diseases.