Search Results (1,540)

Background: Sleep disorders, particularly insomnia, represent a major public health concern, while currently available hypnotic drugs are often limited by adverse effects and poor long-term tolerability. Methods: In this study, we investigated the sleep-promoting effects of a mixture of Hypericum perforatum L. and Melissa officinalis L. extract (HME) and its underlying mechanisms in male ICR and C57BL/6 mice. In a pentobarbital-induced sleep model in mice, sleep onset latency and total sleep time were measured. Pharmacological studies using various antagonists and agonists were conducted to elucidate receptor-mediated mechanisms. Immunohistochemical and immunofluorescence analyses were performed to assess neuronal activity, and cortical mRNA expression was evaluated by quantitative analysis. HPLC analysis was used to identify the major constituents of HME, and their pharmacological profiles were functionally evaluated. Results: HME significantly reduced sleep onset latency and prolonged total sleep time. These hypnotic effects were shown to be mediated through adenosine and melatonin receptor signaling pathways. Immunohistochemical and immunofluorescence analyses showed that HME suppressed neuronal activity in wake-promoting cholinergic and orexinergic neurons of the basal forebrain and lateral hypothalamus, while enhancing activation of sleep-promoting GABAergic neurons in the ventrolateral preoptic nucleus. At the molecular level, HME increased cortical mRNA expression levels of adenosine A₁ receptor, adenosine A_2A receptor, melatonin receptor ₁, and melatonin receptor ₂. From the HPLC analysis, rosmarinic acid and hyperoside were identified as the major constituents of HME. Functional evaluation of these compounds revealed complementary pharmacological profiles, with hyperoside primarily acting through adenosine receptors and rosmarinic acid engaging both adenosine and melatonin receptor pathways. Conclusion: These findings suggest that HME enhances both sleep initiation and maintenance through adenosine and melatonin receptor signaling pathways, thereby supporting its potential as a multitarget therapeutic agent for improving sleep quality. Full article

Incretin receptor agonists (IRAs) such as GLP-1-based therapies improve metabolic and cognitive outcomes and enhance brain insulin signaling. One way that IRAs could have these actions is by affecting the blood–brain barrier (BBB); however, IRA-BBB interactions are poorly studied. Here, we examined the ability of insulin and IRAs to affect each other’s transport across the BBB in lean mice. We found that intracerebroventricular (ICV) administration of the insulin receptor antagonist S961 did not affect the blood-to-brain transport of the bioactive fragment of the IRA, ¹²⁵I-dulaglutide (BAF). In contrast, ¹²⁵I-dulaglutide (BAF) co-administered with intravenous (IV) insulin significantly enhanced ¹²⁵I-dulaglutide (BAF) BBB transport into whole brain, olfactory bulb, parietal cortex, and pons, demonstrating insulin-dependent modulation of IRA BBB transport. Regional transport rates for ¹²⁵I-dulaglutide (BAF) across the brain varied by ~2.5-fold, with the fastest transport into the olfactory bulb, frontal cortex, cerebellum, and pons. Co-administration of IV dulaglutide (BAF) did not alter ¹²⁵I-insulin BBB transport rates (K_i) but did reduce reversible insulin binding (V_i) at the BBB by >50%, suggesting rapid effects on BBB insulin receptors. To explore the effects of chronic IRA administration, lean mice were treated with semaglutide for two weeks. Body weight and food intake were unchanged, but female mice showed reduced fasting levels of serum insulin and GLP-1 and decreased insulin transport into whole brain, while male mice showed a reduction in insulin binding at the BBB. Chronic semaglutide also reduced ¹²⁵I-insulin BBB transport in female mice when studied with in situ perfusion, a procedure that removes the immediate influence of serum factors. Together, these findings demonstrate reciprocal and female-selective interactions between IRAs and insulin at the BBB. Acute insulin enhances the BBB transport of an IRA in female mice, whereas chronic IRA exposure selectively impairs insulin BBB transport in females, highlighting the BBB as a dynamic and hormone-sensitive interface with implications for long-term treatment in mouse models and potential for translation impact in humans. Full article

Patients with liver cancer frequently exhibit abnormal liver function and disorders in lipid metabolism. This study investigates the effects of Oleanolic acid (OA) on hepatocellular carcinoma (HCC) through the regulation of lipid metabolism. Computational simulations identified six core targets of OA, including PPARα, HMGCR, and ESR1, with stable binding confirmed through molecular docking and dynamics analyses. The experiments demonstrated that OA reduced intracellular lipid accumulation, suppressed cell migration (p < 0.05), and promoted apoptosis. The levels of lipid droplets and triglycerides (TG) were significantly decreased (p < 0.05). The expression levels of lipid metabolism-related genes, including PPARA, CPT1A, FASN, and HMGCR, were assessed using qRT-PCR (p < 0.05). Additionally, protein expression levels were analyzed through Western blotting (p < 0.05). Furthermore, the combination of OA with the antagonist GW6471 enhanced tumor suppression, while the combination with the agonist Pemafibrate reversed the effects of OA. Compared to OA alone, the antagonist combination significantly reduced PPARα and CPT1A protein expression (p < 0.05), whereas Pemafibrate upregulated these proteins (p < 0.05). In conclusion, OA exerts its anti-lipid metabolism effects in HCC by modulating the PPARα-CPT1A axis, indicating its potential therapeutic value in liver cancer treatment. Full article

Background/Objectives: Promoting white adipose tissue (WAT) browning into thermogenic beige adipocytes is a promising anti-obesity strategy. Yanggyeoksanhwa-tang (YST) has been used traditionally to alleviate obesity-related conditions. Catalpol and rhoifolin are major bioactive components of Rehmannia glutinosa (Gaertn.) and Lonicera japonica (Thunb.) with known metabolic or anti-inflammatory effects. However, their direct roles in adipocyte browning and the mechanisms via β3-adrenergic receptor (β3-AR) signaling are not well defined, and this study addresses this gap. Methods: To evaluate browning potential, 3T3-L1 adipocytes were treated with catalpol and rhoifolin during differentiation. The expression of browning markers and lipid metabolism or catabolism transcription factors was analyzed using Western blotting and quantitative real-time polymerase chain reaction. The involvement of the β3-AR and adenosine monophosphate–activated protein kinase (AMPK) signaling pathways was further validated using specific agonists and antagonists. Results: Both compound treatments significantly upregulated beige-specific (Cd137, Cited, Tbx1, Cidea, Fgf21, Tmem26) and mitochondrial biogenesis markers (Cox4, Nrf1, Tfam), accompanied by a marked increase in thermogenic markers (UCP1, PGC-1α, Prdm16). Concurrently, lipolysis-related genes such as Atgl, Hsl, and Plin1 were elevated, while lipogenesis targets (Fasn, Lpl, Srebf1, Acaca) were downregulated through activation of the β3-AR signaling pathway. Conclusions: These findings suggest that catalpol and rhoifolin, key phytochemicals of YST, promote WAT browning and lipolysis. Our findings indicate that these compounds induce browning and modulate metabolism via the β3-AR pathway. These results serve as a cornerstone for natural anti-obesity therapy, pending further validation in vivo and clinical studies. Full article

Sigmar1 is a multifunctional molecular chaperone protein located on the Mitochondria-associated endoplasmic reticulum membranes (MAM). Recent studies have shown that Sigmar1 is not only a regulatory protein involved in cellular stress responses but also plays a significant role in the process of autophagy. It regulates the initiation and progression of autophagy by influencing multiple autophagy-related signaling pathways and interacting with key proteins such as LC3 and GABARAP. This regulation exhibits a dual nature. On one hand, it can induce protective autophagy, helping cells cope with stress such as oxidative stress and endoplasmic reticulum stress, thereby playing a protective role in the progression of diseases such as neurodegenerative disorders and cardiovascular diseases. On the other hand, in certain cancers, Sigmar1 may also promote tumor cell survival through autophagy regulation, thereby exacerbating disease progression. Consequently, developing agonists and antagonists targeting Sigmar1 has become a highly promising therapeutic strategy. This review provides a systematic overview of recent advances in the biological characterization of Sigmar1 and its molecular mechanisms in regulating autophagy. It summarizes the multifaceted roles of Sigmar1 in various diseases and discusses current research progress and the application prospects of Sigmar1 agonists and antagonists, aiming to establish a theoretical foundation for the development of novel Sigmar1-based therapeutic strategies for human diseases. Full article

Obesity resulting from melanocortin-4 receptor (MC4R) dysfunction is characterized by combined metabolic dysregulation and maladaptive reward-related behaviors that limit the durability of existing therapies. The endocannabinoid system is a central regulator of appetite, lipid metabolism, and reward processing; however, first-generation cannabinoid receptor 1 (CB1) antagonists were limited by adverse neuropsychiatric effects. SKNY-1 is an orally active tetrahydrocannabivarin (THCV) analog designed to engage pathway-biased CB1 signaling, modulate cannabinoid receptor 2 (CB2), and selectively inhibit monoamine oxidase B (MAO-B), with the objective of addressing both metabolic and behavioral components of obesity while minimizing central nervous system liability through biased CB1 signaling, CB2 modulation, and potential complementary MAO-B inhibition. Here, we integrated in vitro pharmacological profiling of SKNY-1 with in vivo evaluation in an adult mc4r(G894C) zebrafish model exhibiting obesity-associated metabolic and reward-related phenotypes. In vitro, SKNY-1 displayed low-potency modulation of CB1 cyclic AMP signaling (EC₅₀ ~30 µM) but more potent antagonism of the CB1 β-arrestin pathway (IC₅₀ ~6 µM), consistent with differential CB1 pathway modulation. SKNY-1 acted as a CB2 partial agonist (EC₅₀ ~0.1 µM), with antagonist activity emerging at higher concentrations, and selectively inhibited MAO-B at low affinity with no activity against MAO-A. In vivo, mc4r(G894C) zebrafish mutants exhibited dyslipidemia, hepatic triglyceride accumulation, altered appetite-regulatory gene expression, increased metabolic rate, and enhanced compulsive high-calorie feeding and nicotine-seeking behaviors. Oral administration of SKNY-1 for six days produced dose-dependent effects. Both doses normalized total cholesterol and low-density lipoprotein levels and reduced hepatic triglycerides toward wild-type values without affecting circulating triglycerides. The higher dose (200 ng per fish per day) induced significant body weight reduction while preserving body density and attenuated reward-associated feeding and nicotine-seeking behaviors. The lower dose (20 ng per fish per day) more effectively normalized the leptin a-to-ghrelin expression ratio. Collectively, these findings demonstrate that SKNY-1 engages integrated endocannabinoid and potential dopaminergic mechanisms to improve metabolic parameters and attenuate maladaptive reward-related behaviors in an MC4R-deficient vertebrate model, supporting its further translational investigation for obesity complicated by compulsive eating and substance-seeking behaviors. Full article

Background and Objectives: Sevoflurane, a widely used volatile anesthetic, can induce oxidative stress and apoptosis, but the underlying mechanisms in human cardiomyocytes remain unclear. This study investigated the role of transient receptor potential vanilloid 1 (TRPV1) channels in sevoflurane-induced cardiotoxicity and the potential mitigating effect of ascorbic acid. Materials and Methods: Human cardiomyocytes were exposed to sevoflurane (5.1%, 6 h) and/or ascorbic acid (1 mM, 30 min), with or without the TRPV1 channel antagonist capsazepine and with the TRPV1 channel agonist Capsaicin. Intracellular calcium, reactive oxygen species (ROS), apoptosis, mitochondrial membrane potential, and caspase-3/9 activities were assessed. Results: Sevoflurane significantly increased intracellular calcium levels, ROS production, mitochondrial depolarization, apoptosis, and caspase-3/9 activity compared with controls (p < 0.001). These effects were attenuated by capsazepine, suggesting a role for TRPV1 involvement. Ascorbic acid pretreatment significantly reduced sevoflurane-induced elevations in all parameters (p < 0.001). Combined ascorbic acid and capsazepine treatment yielded further reductions in calcium, ROS, apoptosis, and caspase activities compared to ascorbic acid alone (p < 0.05). Conclusions: Sevoflurane induces apoptosis in human cardiomyocytes via ROS-mediated activation of the TRPV1 channel, leading to calcium overload, mitochondrial dysfunction, and caspase-dependent cell death. Ascorbic acid exerts mitigating effects by reducing oxidative stress and modulating TRPV1 channel activity, suggesting a potential therapeutic strategy for myocardial protection during sevoflurane anesthesia. Full article

Background: Glucagon-like peptide-1 receptor agonist (GLP-1 RA) use has increased exponentially as studies show significant benefits in cardiovascular and renal diseases and obesity. Accessibility to the public also increased after compounding pharmacies began direct-to-consumer distribution. Gastrointestinal side effects are common; however, hypersensitivity reactions are rare. Case Presentation: A 50-year-old female with a history of obesity, hypertension, and lisinopril-induced angioedema presented to the Emergency Department with swelling of the lips, tongue, and throat developing four hours after her first injection of compounded semaglutide for weight loss. She was treated with epinephrine, corticosteroids, and antihistamines, but due to progressive airway edema, she required intubation and mechanical ventilation for four days. After extubation, she reported accidentally injecting a ten-fold higher dose (2 mg) of semaglutide than was appropriate for the first dose. The hospitalization was complicated by hypoglycemia requiring dextrose infusion, but was otherwise unremarkable, and she was discharged home on day 7. Based on the temporal onset after semaglutide injection, this presentation was most consistent with GLP-1 RA-induced angioedema. While she also had a history of lisinopril-induced angioedema five years earlier, and had been taking valsartan for hypertension, the remoteness of the lisinopril exposure made this less likely. Conclusions: Semaglutide use may be associated with severe angioedema within hours of administration. Given the overlapping indications and patient populations, angioedema appearing in patients taking both GLP-1 RAs and ACE inhibitors may become increasingly common and present a diagnostic dilemma. Diagnosis of hypersensitivity to GLP-1 RAs can be supported with history and positive skin testing. Clinicians should be aware that inexperienced patients are at the highest risk of dosing errors. Full article

Chronic kidney disease (CKD) is a major global health burden associated with substantially increased risks of morbidity and mortality. Cardiovascular disease remains the leading cause of death across all stages of CKD. Over the past few decades, several pharmacologic therapies—including renin–angiotensin system inhibitors, sodium–glucose cotransporter-2 inhibitors, mineralocorticoid receptor antagonists, glucagon-like peptide-1 receptor agonists, and lipid-lowering agents—have demonstrated substantial cardio-nephroprotective benefits and are recommended in international guidelines. However, real-world implementation of these therapies remains incomplete, and emerging evidence highlights important sex-based disparities in prescribing patterns. Although CKD is more prevalent in women worldwide, women with CKD are consistently less likely than men to receive guideline-directed cardioprotective and nephroprotective medications. This treatment gap spans both traditional therapies, such as angiotensin-converting enzyme inhibitors and statins, and newer agents with proven outcome benefits. Women are less likely to initiate treatment, less likely to receive high-intensity or target doses, and less likely to achieve recommended blood pressure and lipid goals. Importantly, the presence of CKD attenuates the usual female survival advantage, and the relative excess cardiovascular risk associated with CKD may be particularly pronounced in women. The under-prescription of cardio-renal therapies in women with CKD reflects a complex interplay of factors. These include older age at presentation, higher reported rates of adverse drug reactions, concerns regarding tolerability and safety in advanced kidney disease, therapeutic inertia, underestimation of cardiovascular risk, and persistent underrepresentation of women in clinical trials. Biological differences in pharmacokinetics and pharmacodynamics, as well as structural and system-level barriers, further contribute to inequities in care. Addressing these disparities requires improved risk recognition, sex-informed prescribing practices, enhanced representation of women in clinical research, and implementation strategies that incorporate sex-disaggregated performance metrics. Reducing treatment gaps is essential to improving cardiovascular and renal outcomes and to achieving equitable, precision-based care for women with CKD. Full article

Human endometrial mesenchymal stem/stromal cells (eMSCs) are widely used in laboratories and clinical applications to study various aspects of tissue engineering and regenerative medicine. Three-dimensional (3D) cultivated MSCs have a higher therapeutic efficacy compared to 2D culture. Ion channels are involved in maintaining many physiological cell functions, including proliferation, differentiation, apoptosis, and migration. This study describes the functional expression of voltage-gated sodium channels (NaV) in eMSCs and the role of these channels in cell migration. Using RT-PCR analysis and immunofluorescent microscopy, we identified the expression of almost all pore-forming alpha (NaV 1.1, 1.2, 1.4–1.9) and channel-modulating beta-NaV subunits (except beta2) in eMSCs. In the whole-cell patch-clamp configuration, channels activated by membrane depolarization of eMSC were detected. The channels were blocked by the selective NaV antagonist TTX in nanomolar concentrations. The NaV agonist veratridine at a concentration of less than 40 μM inhibited voltage-gated sodium currents, while 100 μM and above prevented channel inactivation. The wound healing assay showed that both TTX (10 μM) and veratridine (100 μM) reduced the migration properties (the wound healing rate) of eMSCs cultivated in 2D conditions compared to the control. An opposite effect by both agents was shown on the motility of eMSCs cultivated in 3D conditions, increasing the cell spreading rate from spheroids. Our data suggest that NaV channels are expressed in human eMSCs and play an important role in the regulation of stem cell migration; this regulatory mechanism significantly depends on the culture conditions of MSCs. Full article

The American Heart Association (AHA) recently formalized cardiovascular–kidney–metabolic (CKM) syndrome to characterize the systemic interplay among cardiovascular failure, chronic kidney disease (CKD), and metabolic disturbances. Despite evolving clinical management, identifying a unifying cellular driver of this multi-organ deterioration remains a critical priority. This review explores the hypothesis that mitochondrial dysfunction serves as the fundamental pathological nexus of CKM syndrome, driving the progression from early-stage metabolic risk to end-stage organ failure. We synthesize evidence demonstrating how nutrient overload and lipotoxicity precipitate a vicious cycle of bioenergetic failure. In the cardiovascular system, ATP deficiency and impaired mitophagy lead to the structural remodeling observed in both heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF). In the kidney, the high mitochondrial density of proximal tubules renders them uniquely susceptible to oxidative stress and mitochondrial DNA (mtDNA) leakage, which subsequently triggers systemic inflammation. Furthermore, we analyze how established therapies—including sodium–glucose co-transporter 2 (SGLT2) inhibitors, Glucagon-like peptide-1 (GLP-1) receptor agonists, and non-steroidal mineralocorticoid receptor antagonists (MRAs)—exert organ-protective effects via mitochondrial mechanisms, promoting metabolic efficiency, reducing reactive oxygen species generation, stabilizing mitochondrial integrity, and promoting mitochondrial quality control processes. Finally, we review emerging mitochondrial-targeted strategies, such as mitoquinol, elamipretide and NAD+ boosters, which aim to restore the SIRT1-PGC-1 α signaling axis. Mitochondria function as the central engines of the CKM axis. A shift toward a mitocentric clinical model may enable earlier intervention and more precise targeting of the mechanisms driving organ crosstalk. Future success depends on multidisciplinary collaboration and the validation of mitochondrial biomarkers to advance precision medicine in CKM syndrome. Full article

Recent Phase 3 clinical trials of selective kappa-opioid (KOP) receptor antagonists aticaprant and navacaprant failed to demonstrate sufficient clinical efficacy in treatment-resistant depression (TRD). This highlights a critical gap in current strategies that target opioid-mediated hedonic suppression. We propose two hypotheses to explain these setbacks: (1) neutral antagonists are inherently ineffective in blocking constitutively active KOP receptor hyperactivation and (2) the nociceptin opioid (NOP) receptor provides functional redundancy that compensates for KOP receptor blockade. Gaining insights from paralogous compensation in drug-resistant tumors, we argue for shifting from selective opioid antagonists to dual KOP/NOP receptor blockers to meaningfully improve reward function. This concept provides a theoretical framework for overcoming clinical resistance where selective KOP targeting with neutral antagonists has failed. Thus, we advocate for the development of opioid inverse agonists (such as nor-BNI, CAS: 105618-26-6), pan-antagonists (such as AT-076, CAS: 1657028-64-2), and combinations of selective blockers. Full article

Concurrent alcohol and cannabis use (“crossfading”) is increasingly prevalent, especially among adolescents, yet its toxicological impact on pulmonary innate immunity remains largely unexplored. Alveolar macrophages (AMs) orchestrate inflammatory responses in the lung, and dysregulated macrophage polarization is a hallmark of alcohol-associated lung disease. Although alcohol and cannabinoids individually modulate immune function, the mechanisms by which their co-exposure alters macrophage activation and inflammatory signaling in the lung are largely unknown. AMs are highly sensitive to xenobiotic exposure and play a central role in regulating inflammatory and cytotoxic responses. In this study, we investigated how acute ethanol exposure, synthetic cannabinoid exposure, and their combined exposure affect macrophage viability, polarization, and the release of inflammatory mediators via cannabinoid receptor (CB1R/CB2R)-dependent pathways. Human THP-1-derived macrophages and KG-1 macrophage-like cells were exposed to ethanol, the CB1/CB2 agonist WIN 55,212-2, or both, with selective pharmacological antagonism of CB1R and CB2R. Ethanol exposure activated and polarized macrophages toward a pro-inflammatory M1 phenotype, accompanied by increased secretion of pro-inflammatory cytokines MCP-1, TGF-α, IFN-β, IL-6, and TNF-α. In contrast, WIN 55,212-2 promoted anti-inflammatory M2 polarization and increased IL-10 and IL-4 production. Notably, co-exposure to ethanol and WIN produced an antagonistic immunomodulatory response, characterized by the suppression of ethanol-induced M1 polarization and attenuation of pro-inflammatory cytokine release. Mechanistically, pharmacological CB1R blockade reduced ethanol-induced M1 polarization and cytokine secretion, whereas CB2R blockade exacerbated these effects, underscoring divergent roles for cannabinoid receptors in regulating pulmonary macrophage responses. This study provides novel findings demonstrating the mechanism by which alcohol–cannabinoid co-use reshapes macrophage immune phenotypes and identifies the endocannabinoid system as a potential therapeutic target for alcohol-related inflammatory lung disease. Full article

Regulation of all-trans retinoic acid (ATRA) signaling is crucial to early embryonic development. Embryonic stem (ES) cell-derived gastruloids mimic normal development in response to the Wnt/β-catenin agonist CHIR9901, and this study has examined the importance of the activities of RAR (retinoic acid receptor) α and γ to gastruloid development. Expression of retinoic acid receptor (RAR)γ within developing gastruloids was spatially restricted to primitive cells that co-expressed ES cell and early progenitor cell markers, i.e., Nanog, Sox2, and Oct4. In contrast, RARα expression was ubiquitous. mRNAs for the key enzymes involved in ATRA synthesis (Aldh1a2) and degradation (Cyp26a1) were not seen in cells that expressed RARγ. Treatment of ES cell-derived gastruloids with physiologically relevant (10 nm) levels of ATRA or with a highly selective RARγ agonist blocked normal developmental processes, preventing symmetry-breaking and axial elongation. This was not seen following treatments with an RARα agonist, where there was a tendency for enhanced axial elongation. Brachyury (TBXT) immuno-positive cells localized in the posterior end of elongated gastruloids in control- and RARα agonist-treated cultures, with Sox2 immuno-positive cells seen more widely, whilst both TBXT and Sox2 immuno-positive cells were randomly distributed throughout ATRA- and RARγ agonist-treated gastruloids. Concurrent treatment of gastruloids with 10 nm ATRA and 100 nm of an RARγ antagonist partially abrogated the ATRA-mediated block to axial elongation. Conversely, 10 nm RARγ antagonist treatments were associated with the formation of multi-axis gastruloid elongations, with comparatively little effect seen after treatments with an RARα antagonist. These findings reveal that RARγ plays a crucial role in the development of embryonic tissues. Full article

Background/Objectives: Leprosy is a chronic infection caused by Mycobacterium leprae that, in addition to Schwann cells, macrophages, and adipocytes, also infects human peripheral blood monocytes and subverts their metabolism in its favor. Infection is marked by cholesterol and fatty acid accumulation in lipid droplets (LDs), and a reduction in mitochondrial membrane potential (Δψm). Previous studies showed that M. leprae downregulates adenosine receptor A_2A (A_2AR) expression in Schwann cells, while activation reduces LD accumulation and bacterial viability. Since A_2AR controls immunometabolic response, we investigated whether A_2AR signaling restrains M. leprae-driven reprogramming in monocytes. Methods: Peripheral blood mononuclear cells from healthy donors were enriched for monocytes and infected with M. leprae in the presence or absence of adenosinergic modulators (5′AMP, adenosine (ADO), A_2AR agonist CGS21680, the antagonist ZM241385, or A_2BR antagonist, MRS1754). We used flow cytometry, fluorescence microscopy, and RT-qPCR to evaluate purinergic components expression and bacillary viability. LDs and Δψm were measured by fluorescence microscopy, and extracellular levels of inosine (INO) and hypoxanthine (HPX) by LC-MS/MS. Results: The results show that infection increased CD39, ADA, A_2AR and A₃R expression, decreased ENT1, A₁R and A_2BR, and raised extracellular INO and HPX. In addition, 5′AMP, ADO and CGS21680 reversed infection-induced LD accumulation. CGS21680 also restored Δψm and decreased intracellular M. leprae viability. Conclusions: Our data suggest that M. leprae suppresses A_2AR signaling to favor its survival in monocytes, indicating that the extracellular ADO–A_2AR pathway may be a potential target to limit early M. leprae infection. Full article