PTP1B Inhibitors Research Articles

Ball milling extraction as a green and efficient approach for the extraction of sixteen xanthone-type QR-2 and PTP1B inhibitors from Garcinia mangostana L. pericarp

Ball milling extraction as a green and efficient approach for the extraction of sixteen xanthone-type QR-2 and PTP1B inhibitors from Garcinia mangostana L. pericarp

Ursolic Acid Derivatives Bearing 1,2,3-triazole Moieties as Potential PTP1B Inhibitors

Ursolic Acid Derivatives Bearing 1,2,3-triazole Moieties as Potential PTP1B Inhibitors

Effects of dietary wild bitter melon (Momordica charantia var. abbreviate Ser.) extract on glucose and lipid metabolism in HFD/STZ-induced type 2 diabetic rats.

Plant-based extracts to interfere with the onset of diabetes may be a promising approach towards type 2 diabetes mellitus (T2DM). Bitter gourd (Momordica charantia L.) is popularly consumed as an edible and medicinal resource with hypoglycemic effect in China. Wild bitter gourd (Momordica Charantia var. abbreviata Ser.) is a variant of bitter gourd, but there are relatively few studies on it. The purpose of the experiment is to first screen out the most effective extraction part of Momordica charantia L. and Momordica Charantia var. abbreviata Ser. through the hypoglycemic activity experiment in vitro, and by using a high-fat and high-sugar diet with STZ-induced diabetic rat model in vivo to explore the possible mechanism of action against diabetes. This study first performed α-glucosidase, PTP1B and lipase activities inhibition experiments on the alcohol and water extracts of Momordica charantia L. and Momordica Charantia var. abbreviata Ser. Sprague Dawley rats were either given normal feed or a high sugar and fat diet for four weeks, followed STZ (25 mg/kg, via i. p.) was given. Rats with fasting blood glucose ≥11.1 mmol/l after one week were deemed to be diabetic, treatments were administered for four weeks, and then blood samples were used to evaluate hematological and biochemical indicators, and liver was removed for post-analysis. The expression levels of p-AMPK, AMPK, p-PI3K, PI3K, p-AKT, AKT, p-GSK3β, GSK3β, p-IRS-1, IRS-1, GLUT2 were determined by Western blot. At the same time, the chemical components was identified by liquid-mass spectrometry. Data showed that the ethanol extract of wild bitter gourd (WBGE) had the best ability to regulate glucose and lipid metabolism in vitro. Therefore, we further investigated the antidiabetic effects of oral consumption of WBGE on high-fat diet (HFD) and streptozotocin (STZ)-induced T2DM in SD rats. WBGE effectively reduced blood glucose and lipid levels, alleviated glucose intolerance and insulin resistant. Moreover, WBGE consumption could also inhibited oxidant responses and inflammatory damage. Mechanism studies have shown that WBGE may act by regulating AMPK/PI3K signaling pathway. On the other hand, the content of total phenol, total flavonoids, total saponins and total polysaccharide were measured by UV, 27 compounds were identified by LC-MS. These studies explored the role and mechanism of WBGE in regulating glucose and lipid metabolism, and may support the utilization and further investigation of wild bitter gourd as a dietary intervention strategy to prevent diabetes and related metabolic abnormalities.

Potential Effect of Phlorotannins in Brown Algae for Antidiabetic Therapy: Molecular Docking Approach

This study aims to manifest the effect of the active compound phlorotannins in brown algae on decreasing insulin resistance by analyzing the predicted interaction between phlorotannins and protein tyrosine phosphatase 1B (PTP 1B) and estimating the pharmacokinetics and toxicity of the active compound for type 2 diabetes mellitus (DM) therapy. This type of research uses an in silico study to test the effect of using phlorotannins as an active compound in brown algae against PTP 1B inhibition. Starting from preparing materials, i.e., downloading the three-dimensional structure of phlorotannins via PubChem and PTP 1B via RSCB PDB (PDB 1A5Y), molecular docking using Molegro Virtual Docker 5, molecular visualization using PyMol and Discovery Studio, and predicting pharmacokinetics and toxicity via pkCSM have been conducted. Here, the phlorotannins include phloroglucinol, dioxinodehydroeckol, eckol, phlorofucofuroeckol-A, dieckol, 7-phloroeckol, and 6,6′-bieckol. In addition, Ertiprotafib and S-phosphocysteine are used here as the comparison controls for docking validation. All phlorotannins can bind to PTP 1B at the same binding site with drug control. Experimental results revealed that phlorotannins–PTP 1B produces lower energy than complex S-phosphocysteine–PTP 1B (−266.8 kJ/mol), which acts as a control here. However, phloroglucinol–PTP 1B produces (−208 kJ/mol) under the same condition. Compared with the drug control Ertiprotafib (−322.8 kJ/mol), the lower bond energy is owned by phlorofucofuroeckol-A (−370.6 kJ/mol), 7-phloroeckol (−328 kJ/mol), dieckol (−331.8 kJ/mol), and 6.6'-bieckol (−341 kJ/mol). Furthermore, phlorotannins are very well absorbed in the intestine. According to Lipinski’s rule, active compounds, such as phloroglucinol, eckol, and dioxinodehydroeckol have high potential as a drug. Phlorotannins are nontoxic against hepatocytes and have fewer side effects than drug control. Based on the obtained data, use of the active compound phlorotannins in brown algae can decrease insulin resistance, which can be employed as adjunctive therapy in type 2 DM.

Targeting protein tyrosine phosphatases for CDK6-induced immunotherapy resistance

Elucidating the mechanisms of resistance to immunotherapy and developing strategies to improve its efficacy are challenging goals. Bioinformatics analysis demonstrates that high CDK6 expression in melanoma is associated with poor progression-free survival of patients receiving single-agent immunotherapy. Depletion of CDK6 or cyclin D3 (but not of CDK4, cyclin D1, or D2) in cells of the tumor microenvironment inhibits tumor growth. CDK6 depletion reshapes the tumor immune microenvironment, and the host anti-tumor effect depends on cyclin D3/CDK6-expressing CD8+ and CD4+ Tcells. This occurs by CDK6 phosphorylating and increasing the activities of PTP1B and Tcell protein tyrosine phosphatase (TCPTP), which, in turn, decreases tyrosine phosphorylation of CD3ζ, reducing the signal transduction for Tcell activation. Administration of a PTP1B and TCPTP inhibitor prove more efficacious than using a CDK6 degrader in enhancing Tcell-mediated immunotherapy. Targeting protein tyrosine phosphatases (PTPs) might be an effective strategy for cancer patients who resist immunotherapy treatment.

The importance of including the C-terminal domain of PTP1B1-400 to identify potential antidiabetic inhibitors

In the present work, we studied the inhibitory and kinetic implications of classical PTP1B inhibitors (chlorogenic acid, ursolic acid, suramin) using three enzyme constructs (hPTP1B1-285, hPTP1B1-321, and hPTP1B1-400). The results indicate that the unstructured region of PTP1B (300-400 amino acids) is very important both to obtain optimal inhibitory results and propose classical inhibition mechanisms (competitive or non-competitive) through kinetic studies. The IC50 calculated for ursolic acid and suramin using hPTP1B1-400 are around four and three times lower to the short form of the enzyme, the complete form of PTP1B, the one found in the cytosol (in vivo). On the other hand, we highlight the studies of enzymatic kinetics using the hPTP1B1-400 to know the type of enzymatic inhibition and to be able to direct docking studies, where the unstructured region of the enzyme can be one more option for binding compounds with inhibitory activity.

Coupling substrate-trapping with proximity-labeling to identify protein tyrosine phosphatase PTP1B signaling networks

The ability to define functional interactions between enzymes and their substrates is crucial for understanding biological control mechanisms; however, such methods face challenges in the transient nature and low stoichiometry of enzyme-substrate interactions. Now, we have developed an optimized strategy that couples substrate-trapping mutagenesis to proximity-labeling mass spectrometry for quantitative analysis of protein complexes involving the protein tyrosine phosphatase PTP1B. This methodology represents a significant shift from classical schemes; it is capable of being performed at near-endogenous expression levels and increasing stoichiometry of target enrichment without a requirement for stimulation of supraphysiological tyrosine phosphorylation levels or maintenance of substrate complexes during lysis and enrichment procedures. Advantages of this new approach are illustrated through application to PTP1B interaction networks in models of HER2-positive and Herceptin-resistant breast cancer. We have demonstrated that inhibitors of PTP1B significantly reduced proliferation and viability in cell-based models of acquired and de novo Herceptin resistance in HER2-positive breast cancer. Using differential analysis, comparing substrate-trapping to wild-type PTP1B, we have identified multiple unreported protein targets of PTP1B with established links to HER2-induced signaling and provided internal validation of method specificity through overlap with previously identified substrate candidates. Overall, this versatile approach can be readily integrated with evolving proximity-labeling platforms (TurboID, BioID2, etc.), and is broadly applicable across all PTP family members for the identification of conditional substrate specificities and signaling nodes in models of human disease.

Discovery of Novel PTP1B Inhibitors with Once-Weekly Therapeutic Potential for Type 2 Diabetes: Design, Synthesis, and In Vitro and In Vivo Investigations of BimBH3 Peptide Analogues.

Poor medication adherence in patients with type 2 diabetes mellitus has become one of the main causes of suboptimal glycemic control. Once-weekly drugs can markedly improve the convenience, adherence, and quality of life of T2DM patients; thus, they are clinically needed and preferred. PTP1B plays a negative role in both insulin and leptin signaling pathways, which makes it an important target for diabetes. Herein, we design and synthesize 35 analogues of core BimBH3 peptide via lipidation/acylation strategy based on our previous work and evaluate their PTP1B inhibitory activity, obtaining the primary structure-activity relationship. Five compounds with good PPT1B inhibitory activity, target selectivity, and significantly improved stability were selected for molecular docking study and searching candidate molecules with long-acting antidiabetic potential. The in vivo anti-T2DM evaluation validated the once-weekly therapeutic potential of analogues 19, 26, 27, 31, and 33, which were comparable with semaglutide and therefore presented as promising drug candidates.

Integrated use of ligand and structure-based virtual screening, molecular dynamics, free energy calculation and ADME prediction for the identification of potential PTP1B inhibitors.

Protein tyrosine phosphatases (PTPs) are the group of enzymes that control both cellular activity and the dephosphorylation of tyrosine (Tyr)-phosphorylated proteins. Dysregulation of PTP1B has contributed to numerous diseases including Diabetes Mellitus, Alzheimer's disease, and obesity rendering PTP1B as a legitimate target for therapeutic applications. It is highly challenging to target this enzyme because of its highly conserved and positively charged active-site pocket motivating researchers to find novel lead compounds against it. The present work makes use of an integrated approach combining ligand-based and structure-based virtual screening to find hit compounds targeting PTP1B. Initially, pharmacophore modeling was performed to find common features like two hydrogen bond acceptors, an aromatic ring and one hydrogen bond donor from the potent PTP1B inhibitors. The dataset of compounds matching with the common pharmacophoric features was filtered to remove Pan-Assay Interference substructure and to match the Lipinski criteria. Then, compounds were further prioritized using molecular docking and top fifty compounds with good binding affinity were selected for absorption, distribution, metabolism, and excretion (ADME) predictions. The top five compounds with high solubility, absorption and permeability holding score of - 10 to - 9.3kcal/mol along with Ertiprotafib were submitted to all-atom molecular dynamic (MD) studies. The MD studies and binding free energy calculations showed that compound M4, M5 and M8 were having better binding affinity for PTP1B enzyme with ∆Gtotal score of - 24.25, - 31.47 and - 33.81kcal/mol respectively than other compounds indicating that compound M8 could be a suitable lead compound as PTP1B inhibitor.

Allosteric inhibition via nonpolar terpenoid inhibitors.

Protein tyrosine phosphatases (PTPs) are promising drug targets for treating a wide range of diseases such as diabetes, cancer, and neurological disorders, but their conserved active sites have complicated the design of selective therapeutics. This study examines the allosteric inhibition of PTP1B by amorphadiene (AD) and α-bisabolene(AB), terpenoid hydrocarbons that are unusually selective inhibitors. Molecular dynamics (MD) simulations carried out in this study suggest that both AD and AB can stably sample multiple neighboring sites on the allosterically influential C-terminus of the catalytic domain. Intriguingly, the binding mode of AD and AB differs from that of the most well-studied allosteric inhibitor of PTP1B, BBR. Indeed, biophysical measurements and MD simulations indicate that AD and BBR can bind simultaneously. Upon binding, both inhibitors destabilize the α7 helix and disrupt hydrogen bonds that facilitate closure of the catalytically essential WPD loop. The α7 helix is destabilized through the significant disruption of localized interactions at the α3-α7 helix interface for AD, AB, and BBR. Additionally, our findings suggest that the selectivity of AD and AB to PTP1B over TCPTP is due to relatively small differences in the composition of the α7 which eliminate the hydrophobic pocket in which the ligands bind to PTP1B. These findings indicate that AD and AB may be promising scaffolds for building allosteric inhibitors of PTP1B and illustrate more broadly how unfunctionalized terpenoids can engage in specific interactions with protein surfaces.

Enzyme PTP-1B Inhibition Studies by Vanadium Metal Complexes: a Kinetic Approach.

The medical field now needs more novel drugs to treat obesity and type-2 diabetes mellitus (T2D) than ever before. Obesity and T2D are both characterized by resistance to the hormones leptin and insulin. PTP-1B is a promising target for drug growth, as strong genetic, pharmacological, and biochemical evidence points to the possibility of treating diabetes and obesity by blocking the PTP-1B enzyme. Studies have also found that PTP-1B is overexpressed in patients with diabetes and obesity, suggesting that inhibiting PTP-1B may be a useful technique in their care. There are no clinically used PTP-1B inhibitors, despite the fact that numerous naturally occurring PTP-1B inhibitors have demonstrated great therapeutic promise. This is most likely due to their low activity or lack of selectivity. It is still important to look for more effective and focused PTP-1B inhibitors. A few organovanadium metal complexes were synthesized and characterized, and binding studies on vanadium complexes with PTP-B were also performed using fluorescence emission spectroscopy. Additionally, we theoretically (molecular modeling) and experimentally (enzyme kinetics) examined the PTP-1B inhibitory effects of these vanadium metal complexes and found that they have excellent PTP-1B inhibitory properties.

The PTP1B selective inhibitor MSI-1436 mitigates Tunicamycin-induced ER stress in human hepatocarcinoma cell line through XBP1 splicing modulation.

Protein tyrosine phosphatase PTP1B is considered as a key metabolic enzyme that has been reported to be associated with insulin resistance onset, and underlying cellular metabolic malfunctions, including ER stress and mitochondrial failure. In this study, effects of selective PTP1B inhibition using MSI-1436 on cellular apoptosis, oxidative stress, mitochondrial dysfunction and ER stress have been assessed using an in vitro model of Tunicamycin induced ER stress in HepG2 cell line. Inhibition of PTP1B using MSI-1436 significantly increased cell viability and reduced the number of apoptotic cells as well as the expression of key apoptosis initiators and effectors. MSI-1436 further mitigated ER stress, by downregulating the expression of IRE1, ATF6 and PERK transcripts, all being key ER stress sensors. Interestingly, MSI-1436 inhibited the XBP1 splicing, and thus its UPR-associated transcriptional activity. PTP1B inhibition further enabled to restore proper mitochondrial biogenesis, by improving transmembrane potential, and diminishing intracellular ROS while restoring of endogenous antioxidant enzymes genes expression. PTP1B inhibition using MSI-1436 could improve cellular apoptosis and metabolic integrity through the mitigation of ER and mitochondrial stress signalling pathways, and excessive ROS accumulation. This strategy may be useful for the treatment of metabolic disorders including IR, NAFLD and diabetes.

CX08005, a Protein Tyrosine Phosphatase 1B Inhibitor, Attenuated Hepatic Lipid Accumulation and Microcirculation Dysfunction Associated with Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the common metabolic diseases characterized by hepatic lipid accumulation. Insulin resistance and microcirculation dysfunction are strongly associated with NAFLD. CX08005, an inhibitor of PTP1B with the IC50 of 0.75 ± 0.07 μM, has been proven to directly enhance insulin sensitivity. The present study aimed to investigate the effects of CX08005 on hepatic lipid accumulation and microcirculation dysfunction in both KKAy mice and diet-induced obesity (DIO) mice. Hepatic lipid accumulation was evaluated by hepatic triglyceride determination and B-ultrasound analysis in KKAy mice. Insulin sensitivity and blood lipids were assessed by insulin tolerance test (ITT) and triglyceride (TG)/total cholesterol (TC) contents, respectively. In addition, the hepatic microcirculation was examined in DIO mice by in vivo microscopy. The results showed that CX08005 intervention significantly reduced the TG and echo-intensity attenuation coefficient in the livers of KKAy mice. Furthermore, we found that CX08005 treatment significantly enhanced insulin sensitivity, and decreased plasma TG and/or TC contents in KKAy and DIO mice, respectively. In addition, CX08005 treatment ameliorated hepatic microcirculation dysfunction in DIO mice, as evidenced by increased RBCs velocity and shear rate of the blood flow in central veins and in the interlobular veins, as well as enhanced rate of perfused hepatic sinusoids in central vein area. Additionally, CX08005 administration decreased the adhered leukocytes both in the center veins and in the hepatic sinusoids area. Taken together, CX08005 exhibited beneficial effects on hepatic lipid accumulation and microcirculation dysfunction associated with NAFLD, which was involved with modulating insulin sensitivity and leukocyte recruitment, as well as restoration of normal microcirculatory blood flow.

Root-Extracted lignanamides from Limonium gmelinii (Willd.) Kuntze with a potential PTP1B inhibitory activity by regulating PI3K/AKT signaling pathway

The phytochemical study of Limonium gmelinii roots resulted in the isolation of five lignanamides (1–5). Among them, limoniumins J, K, and M (1, 2, and 4) are undescribed compounds, limoniumin L (3) is a new naturally occurring lignanamide, and limoniumin B (5) is a known compound which showed PTP1B inhibition activity with an IC50 value of 5.05 ± 2.44 μM in our previous work. Spectroscopic data analysis, including 1D and 2D NMR and HRESIMS experiments, established the chemical structures of limoniumins J − M (1–4). Compounds 1–4 showed PTP1B inhibition activity, among which compound 3 showed the most potent PTP1B inhibition with an IC50 value of 2.07 ± 0.05 μM. Compounds 3 and 5 could significantly increase cellular glucose consumption and glucose uptake in L6 muscle cells and could synergize with insulin to promote glucose consumption and glucose uptake in a concentration-dependent manner. The treatment of compound 3 also promoted glycogen synthesis in skeletal muscle cells. Western blot analysis demonstrated that the good hypoglycemic effect of compounds 3 and 5 was achieved by activating PI3K/AKT signaling pathway to promote glucose consumption, glucose uptake, and glycogen synthesis. Furthermore, studies on molecular docking revealed the potent interactions between these bioactive substances and the PTP1B protein.

Plant Foods and Their Phytochemicals as DPP IV and PTP1B Inhibitors for Blood Glucose Regulation: A Review

Plant Foods and Their Phytochemicals as DPP IV and PTP1B Inhibitors for Blood Glucose Regulation: A Review

Novel thieno[2,3-b]quinoline-procaine hybrid molecules: A new class of allosteric SHP-1 activators evolved from PTP1B inhibitors

Small molecule activators could equally provide powerful tools as inhibitors do for interrogating cellular signal transduction. However, targeted protein activation is chemically challenging. Developing activators against Src homology region 2 domain-containing phosphatase-1 (SHP-1) to block STAT3 pathway represents a promising strategy for DLBCL therapy. Here we reported a new class of thieno[2,3-b]quinoline-procaine hybrid molecules as SHP-1 allosteric activators. The representative hybrid compound 3b displayed SHP-1 activating effect with EC50 of 5.48 ± 0.28 µmol/L. Further investigations confirmed that 3b allosterically interacted with SHP-1, switched it from close to open conformation, blocked SHP-1/p-STAT3 pathway, induced apoptosis and inhibited ABC-DLBCL cell proliferation in vitro, and delayed tumor growth in the xenograft model of SU-DHL-2. Overall, this work offered a novel paradigm to develop SHP-1 allosteric activators through chemical space evolution of PTPs inhibitors, and firstly validated the therapeutic strategy that directly activating SHP-1 alone could be a potential therapy against ABC-DLBCL via blocking STAT3 pathway.

PTP1B Inhibitor Claramine Rescues Diabetes-Induced Spatial Learning and Memory Impairment in Mice.

Accumulating clinical and epidemiological studies indicate that learning and memory impairment is more prevalent among people with diabetes mellitus (DM). PTP1B is a member of protein tyrosine phosphatase family and participates in a variety of pathophysiological effects including inflammatory, insulin signaling pathway, and learning and memory. This study was aimed to investigate the effects of CA, a specific inhibitor of PTP1B, on spatial learning and memory impairment in diabetic mice caused by high-fat diet and injection of streptozotocin. We found that the protein expressions of PTP1B increased in hippocampal CA1, CA3, and PFC regions of diabetic mice. Network pharmacology results showed that PTP1B might be one of the key targets between diabetes and cognitive dysfunction, and CA might alleviate DM-induced cognitive dysfunction. Animal experiments showed that CA ameliorated DM-induced spatial learning and memory impairment, and improved glucose and lipid metabolic disorders. Moreover, administration of CA alleviated hippocampal structure damage and enhanced the expressions of synaptic proteins, including PSD-95, SYN-1, and SYP in diabetic mice. Furthermore, CA treatment not only significantly down-regulated the expressions of PTP1B and NLRP3 inflammatory related proteins (NLRP3, ASC, Caspase-1, COX-2, IL-1β, and TNF-α), but also significantly up-regulated the expressions of insulin signaling pathway-related proteins (p-IRS1, p-PI3K, p-AKT, and p-GSK-3β) in diabetic mice. Taken together, these results suggested that PTP1B might be a targeted strategy to rescue learning and memory deficits in DM, possibly through inhibition of NLRP3 inflammasome and regulation of insulin signaling pathway.

Inhibition of PTP1B by isosinensetin, a polymethoxylated flavone isolated from trifoliate orange peel: kinetic studies, molecular docking, and molecular dynamics simulation

Inhibition of PTP1B by isosinensetin, a polymethoxylated flavone isolated from trifoliate orange peel: kinetic studies, molecular docking, and molecular dynamics simulation

Molecular targets of endothelial phosphatidic acid regulating major depressive disorder.

Major depressive disorder (MDD) is a severe disease of unknown pathogenesis with a lifetime prevalence of ~10%. Therapy requires prolonged treatment that often fails. We have previously demonstrated that ceramide levels in the blood plasma of patients and in mice with experimental MDD are increased. Neutralization of blood plasma ceramide prevented experimental MDD in mice. Mechanistically, we demonstrated that blood plasma ceramide accumulated in endothelial cells of the hippocampus, inhibited phospholipase D (PLD) and thereby decreased phosphatidic acid in the hippocampus. Here, we demonstrate that phosphatidic acid binds to and controls the activity of phosphotyrosine phosphatase (PTP1B) in the hippocampus and thus determines tyrosine phosphorylation of a variety of cellular proteins including TrkB. Injection of PLD, phosphatidic acid, or inhibition of PTP1B abrogated MDD and normalized cellular tyrosine phosphorylation, including phosphorylation of TrkB and neurogenesis in the hippocampus. Most importantly, these treatments also rapidly normalized behavior of mice with experimental MDD. Since phosphatidic acid binds to and inhibits PTP1B, the lack of phosphatidic acid results in increased activity of PTP1B and thereby in reduced tyrosine phosphorylation of TrkB and other cellular proteins. Thus, our data indicate a novel pathogenetic mechanism of and a rapidly acting targeted treatment for MDD.

Modulation of hypothalamic AMPK phosphorylation by olanzapine controls energy balance and body weight

BackgroundSecond-generation antipsychotics (SGAs) are a mainstay therapy for schizophrenia. SGA-treated patients present higher risk for weight gain, dyslipidemia and hyperglycemia. Herein, we evaluated the effects of olanzapine (OLA), widely prescribed SGA, in mice focusing on changes in body weight and energy balance. We further explored OLA effects in protein tyrosine phosphatase-1B deficient (PTP1B-KO) mice, a preclinical model of leptin hypersensitivity protected against obesity. MethodsWild-type (WT) and PTP1B-KO mice were fed an OLA-supplemented diet (5 mg/kg/day, 7 months) or treated with OLA via intraperitoneal (i.p.) injection or by oral gavage (10 mg/kg/day, 8 weeks). Readouts of the crosstalk between hypothalamus and brown or subcutaneous white adipose tissue (BAT and iWAT, respectively) were assessed. The effects of intrahypothalamic administration of OLA with adenoviruses expressing constitutive active AMPKα1 in mice were also analyzed. ResultsBoth WT and PTP1B-KO mice receiving OLA-supplemented diet presented hyperphagia, but weight gain was enhanced only in WT mice. Unexpectedly, all mice receiving OLA via i.p. lost weight without changes in food intake, but with increased energy expenditure (EE). In these mice, reduced hypothalamic AMPK phosphorylation concurred with elevations in UCP-1 and temperature in BAT. These effects were also found by intrahypothalamic OLA injection and were abolished by constitutive activation of AMPK in the hypothalamus. Additionally, OLA i.p. treatment was associated with enhanced Tyrosine Hydroxylase (TH)-positive innervation and less sympathetic neuron-associated macrophages in iWAT. Both central and i.p. OLA injections increased UCP-1 and TH in iWAT, an effect also prevented by hypothalamic AMPK activation. By contrast, in mice fed an OLA-supplemented diet, BAT thermogenesis was only enhanced in those lacking PTP1B. Our results shed light for the first time that a threshold of OLA levels reaching the hypothalamus is required to activate the hypothalamus BAT/iWAT axis and, therefore, avoid weight gain. ConclusionOur results have unraveled an unexpected metabolic rewiring controlled by hypothalamic AMPK that avoids weight gain in male mice treated i.p. with OLA by activating BAT thermogenesis and iWAT browning and a potential benefit of PTP1B inhibition against OLA-induced weight gain upon oral treatment.