Tumor microenvironment immunomodulation by nanoformulated TLR 7/8 agonist and PI3k delta inhibitor enhances therapeutic benefits of radiotherapy.

Infiltration of immunosuppressive cells into the breast tumor microenvironment (TME) is associated with suppressed effector T cell (Teff) responses, accelerated tumor growth, and poor clinical outcomes. Previous studies from our group and others identified infiltration of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) as critical contributors to immune dysfunction in the orthotopic claudin-low tumor model, limiting the efficacy of adoptive cellular therapy. However, approaches to target these cells in the TME are currently lacking. To overcome this barrier, polymeric micellular nanoparticles (PMNPs) were used for the co-delivery of small molecule drugs activating Toll-like receptors 7 and 8 (TLR7/8) and inhibiting PI3K delta (PI3Kδ). The immunomodulation of the TME by TLR7/8 agonist and PI3K inhibitor led to type 1 macrophage polarization, decreased MDSC accumulation and selectively decreased tissue-resident Tregs in the TME, while enhancing the T and B cell adaptive immune responses. PMNPs significantly enhanced the anti-tumor activity of local radiation therapy (RT) in mice bearing orthotopic claudin-low tumors compared to RT alone. Taken together, these data demonstrate that RT combined with a nanoformulated immunostimulant diminished the immunosuppressive TME resulting in tumor regression. These findings set the stage for clinical studies of this approach.

Effect of Priming With Toll-Like Receptor 3 Agonist on Expression of Long Noncoding RNAs in Human Wharton Jelly Mesenchymal Stem Cells.

OBJECTIVES: Mesenchymal stem cells are gaining attention in medicine because of their anti-inflammatory and immunosuppressive properties. Inflammatory conditions can modulate immune responses in mesenchymal stem cells.We investigated the expression of long noncoding RNAs (RMRP, MALT1, NKILA,THRIL, and Linc-MAF-4) in humanWharton jelly mesenchymal stem cells primed with polyinosinicpolycytidylic acid. MATERIALS AND METHODS: Mesenchymal stem cells were isolated from human Wharton jelly by the explant method. To determine the stem nature of the cells, we performed a differentiation test on bone and fat cells. We used flow cytometry analysis to determine surface markers. Umbilical cord mesenchymal stem cells (1 × 105) were cultured in T75 culture flasks in Dulbecco's modified Eagle medium containing 10% fetal bovine serum. After cells reached approximately 80% confluency, cells were exposed to 50 µg/mL of polyinosinic-polycytidylic acid, a Toll-like receptor 3 ligand, for 24, 48, and 72 hours. The control group were cells not exposed to polyinosinic-polycytidylic acid. Real-time polymerase chain reaction evaluated RMRP, MALAT1, NKILA, THRIL, and Linc-MAF-4 long noncoding RNAs. RESULTS: We observed significantly increased expression of NKILA inWharton jelly mesenchymal stem cells stimulated with polyinosinic-polycytidylic acid at 72 hours compared with expression level in the control group (P < .001). CONCLUSIONS: Results indicated that a potential mechanism by which the Toll-like receptor 3 ligand improves immunosuppression of mesenchymal stem cells can be attributed to the regulatory role of long noncoding RNAs, possibly through increased expression of anti-inflammatory long noncoding RNAs such as NKILA.

Delivery of a STING Agonist Using Lipid Nanoparticles Inhibits Pancreatic Cancer Growth.

Introduction: The tumor microenvironment (TME) of pancreatic cancer is highly immunosuppressive and characterized by a large number of cancer-associated fibroblasts, myeloid-derived suppressor cells, and regulatory T cells. Stimulator of interferon genes (STING) is an endoplasmic reticulum receptor that plays a critical role in immunity. STING agonists have demonstrated the ability to inflame the TME, reduce tumor burden, and confer anti-tumor activity in mouse models. 2'3' cyclic guanosine monophosphate adenosine monophosphate (2'3'-cGAMP) is a high-affinity endogenous ligand of STING. However, delivering cGAMP to antigen-presenting cells and tumor cells within the cytosol remains challenging due to membrane impermeability and poor stability. Methods: In this study, we encapsulated 2'3'-cGAMP in a lipid nanoparticle (cGAMP-LNP) designed for efficient cellular delivery. We assessed the properties of the nanoparticles using a series of in-vitro studies designed to evaluate their cellular uptake, cytosolic release, and minimal cytotoxicity. Furthermore, we examined the nanoparticle's anti-tumor effect in a syngeneic mouse model of pancreatic cancer. Results: The lipid platform significantly increased the cellular uptake of 2'3'-cGAMP. cGAMP-LNP exhibited promising antitumor activity in the syngeneic mouse model of pancreatic cancer. Discussion: The LNP platform shows promise for delivering exogenous 2'3'-cGAMP or its derivatives in cancer therapy.

[GLP-1 receptor agonists : impact on diabetic kidney disease]. / Agonistes des récepteurs du GLP-1 : ­impact sur la maladie rénale diabétique.

In addition to optimal glycemic control and management of other factors aggravating the pathology (hypertension, dyslipidemia, -obesity), the cornerstone of treatment of diabetic kidney disease (DKD) includes blockers of the renin-angiotensin system, sodium-glucose cotransporter 2 inhibitors or nonsteroidal antagonists of the mineralocorticoid receptor (finerenone). Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are recommended in the treatment of high-risk patients with type 2 diabetes (T2DM) to reduce cardiovascular (CV) risk. Data from CV studies indicate a nephroprotective effect of certain GLP-1 RAs in T2DM patients with DKD. The FLOW study published in May 2024, analyzing the impact of semaglutide vs placebo on renal events as primary outcome, confirms this renal protection of GLP-1 RAs.

Outre le contrôle glycémique et la prise en charge d'autres ­facteurs d'aggravation de la pathologie, la pierre angulaire du traitement de la maladie rénale diabétique (MRD) comprend les bloqueurs du système rénine-angiotensine, les inhibiteurs du cotransporteur sodium-glucose de type 2 ou encore la finérénone (antagoniste de l'aldostérone). Les agonistes du récepteur du glucagon-like peptide-1 (ARGLP-1) sont recommandés dans le traitement des patients avec un diabète de type 2 (DT2) à haut risque afin de réduire le risque cardiovasculaire (CV). Les ­données provenant des études CV indiquent un effet néphro­protecteur de certains ARGLP-1 chez les patients DT2 avec MRD. L'étude FLOW, publiée fin mai 2024 et analysant l'impact du sémaglutide sur les événements rénaux comme critère principal, confirme cette protection rénale des ARGLP-1.

[Innovative therapeutic drug combination for type 2 diabetes at cardiorenal risk]. / Combinaison thérapeutique innovante pour le diabète type 2 à risque cardiorénal.

Both glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve cardiorenal -prognosis of at-risk patients with type 2 diabetes thanks to pleiotropic effects that are either common or specific. This article discusses the clinical efficacy of a combined therapy with the two medications. Data were obtained from post hoc analyses of subgroups of participants to cardiovascular outcome trials and from real-life observational retro-spective cohort studies. The reported superiority of the combination versus either monotherapy should be confirmed in an ongoing large prospective trial (PRECIDENTD). The extra-cost of such a combined therapy as well as the common underuse of each pharmacological class in daily clinical practice deserve attention.

Les agonistes des récepteurs du glucagon-like peptide-1 (ARGLP-1) et les inhibiteurs des cotransporteurs sodium-glucose 2 (iSGLT2) améliorent le pronostic cardiorénal des patients avec un diabète de type 2 à risque grâce à des effets pléiotropes à la fois communs et spécifiques. Cet article discute l'efficacité d'une combinaison des deux classes à partir d'analyses de sous-groupes de participants aux grands essais contrôlés à visée cardiovasculaire et de données observationnelles en vie réelle provenant d'études rétrospectives de cohortes. La supériorité de la combinaison rapportée par rapport à l'une ou l'autre monothérapie devra être confirmée dans un grand essai prospectif en cours (PRECIDENTD). Le surcoût d'une telle combinaison et la sous-utilisation déjà constatée en pratique clinique pour chaque classe méritent attention.

Cardiovascular and diabetes outcomes among patients with obesity and type 2 diabetes after metabolic bariatric surgery or glucagon-like peptide 1 receptor agonist treatment.

BACKGROUND: With the increasing prevalence of obesity and type 2 diabetes, the availability of different treatment options remains essential. Studies comparing the outcomes of glucagon-like peptide 1 receptor agonists with those of metabolic bariatric surgery in patients with type 2 diabetes and obesity are lacking. METHODS: Using propensity score matching, based on data from several nationwide clinical registries, patients who underwent primary metabolic bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy) were matched with patients who received glucagon-like peptide 1 receptor agonists. Outcome measures included the occurrence of major cardiovascular events, microvascular complications, and potential side effects (alcohol/substance abuse, self-harm, and fractures). RESULTS: Over a mean follow-up of 7 years, major cardiovascular events occurred in 191 of 2039 patients (cumulative incidence 14.5%) in the surgery group compared with 247 of 2039 patients (19.6%) in the glucagon-like peptide 1 receptor agonist group (HR 0.75 (95% c.i. 0.62 to 0.91), P = 0.003). Patients in the surgery group had lower haemoglobin A1c values 5 years after treatment (mean difference 9.82 (95% c.i. 8.51 to 11.14) mmol/mol, P < 0.001) and fewer microvascular complications (retinopathy HR 0.88 (95% c.i. 0.79 to 0.99), P = 0.039; nephropathy HR 0.72 (95% c.i. 0.66 to 0.80), P < 0.001; and neuropathy or leg ulcers HR 0.82 (95% c.i. 0.74 to 0.92), P < 0.001), but a higher risk of alcohol/substance abuse (HR 2.56 (95% c.i. 1.87 to 3.50), P < 0.001), self-harm (HR 1.41 (95% c.i. 1.17 to 1.71), P < 0.001), and fractures (HR 1.86 (95% c.i. 1.11 to 3.12), P = 0.019). CONCLUSION: Compared with glucagon-like peptide 1 receptor agonist treatment, metabolic bariatric surgery is associated with superior metabolic outcomes and a lower risk of major cardiovascular events in patients with type 2 diabetes and obesity, but a higher risk of alcohol/substance abuse, self-harm, and fractures.

An in situ depot for the sustained release of a TLR7/8 agonist in combination with a TGFß inhibitor promotes anti-tumor immune responses.

Cancer curing immune responses against heterogeneous solid cancers require that a coordinated immune activation is initiated in the antigen avid but immunosuppressive tumor microenvironment (TME). The plastic TME, and the poor systemic tolerability of immune activating drugs are, however, fundamental barriers to generating curative anticancer immune responses. Here, we introduce the CarboCell technology to overcome these barriers by forming an intratumoral sustained drug release depot that provides high payloads of immune stimulatory drugs selectively within the TME. The CarboCell thereby induces a hot spot for immune cell training and polarization and further drives and maintains the tumor-draining lymph nodes in an anticancer and immune activated state. Mechanistically, this transforms cancerous tissues, consequently generating systemic anticancer immunoreactivity. CarboCell can be injected through standard thin-needle technologies and has inherent imaging contrast which secure accurate intratumoral positioning. In particular, here we report the therapeutic performance for a dual-drug CarboCell providing sustained release of a Toll-like receptor 7/8 agonist and a transforming growth factor-ß inhibitor in preclinical tumor models in female mice.

GnRH agonist-only trigger, compared to dual trigger, reduces oocyte retrieval rate in high responders without affecting cumulative live birth rate.

Introduction: This study compared, in high responders undergoing IVF treatment, GnRH agonist-only trigger and dual trigger on oocyte retrieval rate and cumulative live birth rate (LBR). The aim was to determine if the GnRH agonist-only triggers had provided outcomes comparable to dual trigger, while minimizing the risk of ovarian hyperstimulation syndrome (OHSS). Materials and methods: A retrospective, matched case-control study was conducted at Taichung Veterans General Hospital, Taiwan, including women who underwent IVF/ICSI between January 1, 2014, and December 31, 2022. Inclusion criteria were: GnRH antagonist protocol and estrogen level >3,000 pg/ml on trigger day. Exclusion criteria were: immune/metabolic diseases, donated oocytes, and mixed stimulation cycles. Propensity score matching was applied to balance age, AMH level, and oocyte number between the GnRH agonist-only and dual trigger groups. Outcomes were analyzed for patients who had complete treatment cycles, focusing on oocyte retrieval rate and cumulative LBR. Results: We analyzed 116 cycles in the agonist-only group, and 232 cycles in the dual trigger group. No inter-group difference was found in their age, BMI, and AMH levels. The dual trigger group had a higher oocyte retrieval rate (93% vs. 80%; p <0.05), while fertilization rates, blastocyst formation rates, and cumulative LBR were comparable. Notably, no OHSS cases had been reported in the GnRH agonist-only group, compared with 7 cases in the dual trigger group. Conclusion: GnRH agonist-only triggers resulted in a lower oocyte retrieval rate compared to dual triggers but did not significantly affect cumulative LBR in high responders. This approach effectively reduces OHSS risk without compromising pregnancy outcomes, making it a preferable option in freeze-all strategies, despite a longer oocyte pick-up duration and a medium cost. GnRH agonist-only trigger, however, may not be suitable for fresh embryo transfers or patients with low serum LH levels on trigger day.

GnRH-a-based fertility-sparing treatment of atypical endometrial hyperplasia (AEH) and early endometrial carcinoma (EC) patients: a multicenter, open-label, randomized designed clinical trial protocol.

BACKGROUND: Around 4% of women receive an endometrial cancer diagnosis before turning 40, mainly those without prior childbirth experience and a strong desire to preserve their ability to conceive. Consequently, for young patients diagnosed with atypical endometrial hyperplasia (AEH) or early endometrial carcinoma (EC), a fertility-preserving approach employing high-dose oral progesterone has been adopted. However, previous research has shown a notable relapse rate. Furthermore, the extended use of substantial oral progesterone doses may hinder ovarian function and raise the risk of weight gain, liver issues, blood clotting, and breast cancer. We previously assessed the clinical effectiveness and pregnancy outcomes of gonadotropin-releasing hormone agonist (GnRH-a) based re-treatment for women with EC and AEH who did not respond to oral progestin therapy but achieved favorable treatment results and reproductive outcomes. METHODS: This study will be an open-label, two-armed, randomized, investigator-initiated multicenter trial evaluating the combination of GnRH-a with the levonorgestrel-releasing intrauterine system or the combination of GnRH-a with an aromatase inhibitor (comprising a subcutaneous GnRH-a injection every 4 weeks and daily oral letrozole 2.5 mg). A total of 226 participants will be randomly allocated to one of the two treatment groups in a 1:1 ratio. The primary objective is to determine the effectiveness of GnRH-a-based re-treatment in achieving a complete response (CR) at 24 weeks for patients with AEH or EC. Secondary objectives include assessing the pregnancy rate 12 weeks after treatment, as well as post-treatment pregnancy outcomes and the rate of recurrence. ETHICS AND DISSEMINATION: The protocol received approval from the Institutional Review Board of Peking Union Medical College Hospital and from boards at five other institutions. The trial will adhere to the principles outlined in the World Medical Association's Declaration of Helsinki and follow Good Clinical Practice standards. The trial results will be disseminated through publication in a peer-reviewed journal. CONCLUSIONS: Prospective evidence supporting conservative treatment for EC and AEH is limited. There is a need for new approaches that can achieve higher CR rates with fewer side effects. This trial will assess the effectiveness of GnRH-a-based fertility-sparing treatment in obese women and recurrent patients, offering a promising alternative for patients with EC and AEH. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry ChiCTR2200067099. Registered on December 27, 2022.

GLP-1R-positive neurons in the lateral septum mediate the anorectic and weight-lowering effects of liraglutide in mice.

Liraglutide, a glucagon-like peptide-1 (GLP-1) analog, is approved for obesity treatment, but the specific neuronal sites that contribute to its therapeutic effects remain elusive. Here, we show that GLP-1 receptor-positive (GLP-1R-positive) neurons in the lateral septum (LSGLP-1R) play a critical role in mediating the anorectic and weight-loss effects of liraglutide. LSGLP-1R neurons were robustly activated by liraglutide, and chemogenetic activation of these neurons dramatically suppressed feeding. Targeted knockdown of GLP-1 receptors within the LS, but not in the hypothalamus, substantially attenuated liraglutide's ability to inhibit feeding and lower body weight. The activity of LSGLP-1R neurons rapidly decreased during naturalistic feeding episodes, while synaptic inactivation of LSGLP-1R neurons diminished the anorexic effects triggered by liraglutide. Together, these findings offer critical insights into the functional role of LSGLP-1R neurons in the physiological regulation of energy homeostasis and delineate their instrumental role in mediating the pharmacological efficacy of liraglutide.

Kidney and Cardiovascular Effectiveness of SGLT2 Inhibitors vs GLP-1 Receptor Agonists in Type 2 Diabetes.

BACKGROUND: Emerging data suggest that glucagon-like peptide-1 receptor agonists (GLP-1 RAs) improve kidney outcomes for people with type 2 diabetes (T2D). Direct comparisons of the kidney and cardiovascular effectiveness of GLP-1 RA with sodium-glucose cotransporter 2 inhibitors (SGLT2i), a first-line therapy for this population, are needed. OBJECTIVES: The authors compared kidney and cardiovascular outcomes for new users of SGLT2i and GLP-1 RAs with T2D. METHODS: Using propensity score overlap weighting, we analyzed electronic health record data from 20 U.S. health systems contributing to PCORnet between 2015 and 2020. The primary kidney outcome was a composite of sustained 40% estimated glomerular filtration rate (eGFR) decline, incident end-stage kidney disease, or all-cause mortality over 2 years or until censoring. In addition, we examined cardiovascular and safety outcomes. RESULTS: The weighted study cohort included 35,004 SGLT2i and 47,268 GLP-1 RA initiators. Over a median of 1.2 years, the primary outcome did not differ between treatments (HR: 0.91; 95% CI: 0.81-1.02), although SGLT2i were associated with a lower risk of 40% eGFR decline (HR: 0.77; 95% CI: 0.65-0.91). Risks of mortality (HR: 1.08; 95% CI: 0.92-1.27), a composite of stroke, myocardial infarction, or death (HR: 1.03; 95% CI: 0.93-1.14), and heart failure hospitalization (HR: 0.95; 95% CI: 0.80-1.13) did not differ. Genital mycotic infections were more common for SGLT2i initiators, but other safety outcomes did not differ. The results were similar regardless of chronic kidney disease status. CONCLUSIONS: SGLT2i and GLP-1 RAs led to similar kidney and cardiovascular outcomes in people with T2D, though SGLT2i initiation was associated with a lower risk of 40% eGFR decline. (Evaluating Comparative Effectiveness of Empagliflozin in Type 2 Diabetes Population With and Without Chronic Kidney Disease; NCT05465317).

GLP-1 RAs and SGLT2-Is to Lower Glucose and Reduce the Risk of Cardiovascular and Diabetic Kidney Disease.

The landscape of diabetes management has changed, such that the goal of pharmacotherapy extends beyond glucose-lowering to prioritize risk reduction of cardiovascular disease and diabetic kidney disease. Two newer classes of medications, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2-Is), have become first line therapies for many patients with type 2 diabetes to reduce cardiovascular and renal complications of type 2 diabetes. This review article will describe the mechanism of action, evidence for cardiovascular and kidney outcomes, contraindications, adverse effects, and risk mitigation strategies for the GLP-1 RA and SGLT2-I drug classes. In addition, we will provide a practical approach for primary care clinicians to prescribe, adjust, and combine these medication classes, while considering patient preference, tolerability, comorbidities, cost, and availability.

Enhancing radiotherapy response via intratumoral injection of a TLR9 agonist in autochthonous murine sarcomas.

Radiation therapy (RT) is frequently used to treat cancers, including soft-tissue sarcomas. Prior studies established that the toll-like receptor 9 (TLR9) agonist cytosine-phosphate-guanine oligodeoxynucleotide (CpG) enhances the response to RT in transplanted tumors, but the mechanisms of this enhancement remain unclear. Here, we used CRISPR/Cas9 and the chemical carcinogen 3-methylcholanthrene (MCA) to generate autochthonous soft-tissue sarcomas with high tumor mutation burden. Treatment with a single fraction of 20 Gy RT and 2 doses of CpG significantly enhanced tumor response, which was abrogated by genetic or immunodepletion of CD8+ T cells. To characterize the immune response to CpG+RT, we performed bulk RNA-Seq, single-cell RNA-Seq, and mass cytometry. Sarcomas treated with 20 Gy and CpG demonstrated increased CD8 T cells expressing markers associated with activation and proliferation, such as Granzyme B, Ki-67, and IFN-γ. CpG+RT also upregulated antigen presentation pathways on myeloid cells. Furthermore, in sarcomas treated with CpG+RT, TCR clonality analysis suggests an increase in clonal T cell dominance. Collectively, these findings demonstrate that CpG+RT significantly delays tumor growth in a CD8 T cell-dependent manner. These results provide a strong rationale for clinical trials evaluating CpG or other TLR9 agonists with RT in patients with soft-tissue sarcoma.

Peripheral administration of a κ-opioid receptor agonist nalfurafine inactivates gonadotropin-releasing hormone pulse generator activity in goats.

Neurons co-expressing kisspeptin, neurokinin B, and dynorphin A (KNDy neurons), located in the arcuate nucleus (ARC) of the hypothalamus, are indicated to be the gonadotropin-releasing hormone (GnRH) pulse generator. Dynorphin A is reported to suppress GnRH pulse generator activity. Nalfurafine is a selective agonist of the κ-opioid receptor (KOR), a receptor for dynorphin A, clinically used as an anti-pruritic drug. This study aimed to evaluate the effects of nalfurafine on GnRH pulse generator activity and luteinizing hormone (LH) pulses using female goats. Nalfurafine (0, 2, 4, 8, or 16 µg/head) was intravenously injected into ovariectomized Shiba goats. The multiple unit activity (MUA) in the ARC area was recorded, and plasma LH concentrations were measured 2 and 48 h before and after injection, respectively. The MUA volley interval during 0-2 h after injection was significantly increased in the nalfurafine 8 and 16 µg groups compared with the vehicle group. In 0-2 h after injection, the number of LH pulses was significantly decreased in the nalfurafine 8 and 16 µg groups, and the mean and baseline LH were significantly decreased in all nalfurafine-treated groups (2, 4, 8, and 16 µg) compared with the vehicle group. These results suggest that nalfurafine inhibits the activity of the GnRH pulse generator in the ARC, thus suppressing pulsatile LH secretion. Therefore, nalfurafine could be used as a reproductive inhibitor in mammals.

Cheminformatic Read-Across Approach Revealed Ultraviolet Filter Cinoxate as an Obesogenic Peroxisome Proliferator-Activated Receptor γ Agonist.

This study introduces a novel cheminformatic read-across approach designed to identify potential environmental obesogens, substances capable of disrupting metabolism and inducing obesity by mainly influencing nuclear hormone receptors (NRs). Leveraging real-valued two-dimensional features derived from chemical fingerprints of 8435 Tox21 compounds, cluster analysis and subsequent statistical testing revealed 385 clusters enriched with compounds associated with specific NR targets. Notably, one cluster exhibited selective enrichment in peroxisome proliferator-activated receptor γ (PPARγ) agonist activity, prominently featuring methoxy cinnamate ultraviolet (UV) filters and obesogen-related compounds. Experimental validation confirmed that 2-ethoxyethyl 4-methoxycinnamate, an organic UV filter cinoxate, could selectively bind to PPARγ (Ki = 18.0 µM), eliciting an obesogenic phenotype in human bone marrow-derived mesenchymal stem cells during adipogenic differentiation. Molecular docking and further experiments identified cinoxate as a potent PPARγ full agonist, demonstrating a preference for coactivator SRC3 recruitment. Moreover, cinoxate upregulated transcription levels of genes encoding lipid metabolic enzymes in normal human epidermal keratinocytes as primary cells exposed during clinical usage. This study provides compelling evidence for the efficacy of cheminformatic read-across analysis in prioritizing potential obesogens, showcasing its utility in unveiling cinoxate as an obesogenic PPARγ agonist.

Relationship Between Melatonin Receptor Agonists and Parkinson's Disease.

Parkinson's disease affects millions of people worldwide, and without significant progress in disease prevention and treatment, its incidence and prevalence could increase by more than 30% by 2030. Researchers have focused on targeting sleep and the circadian system as a novel treatment strategy for Parkinson's disease. This study investigated the association between melatonin receptor agonists and Parkinson's disease, using the Food and Drug Administration (FDA) Adverse Events Reporting System (FAERS). The target drugs were melatonin receptor agonists including ramelteon, tasimelteon, and agomelatine. Parkinson's disease cases were defined according to the Medical Dictionary for Regulatory Activities (MedDRA) 25.0; Standardized MedDRA Query (SMQ) using both the "narrow" and "broad" preferred terms (PTs) associated with Parkinson's disease. The association between melatonin receptor agonists (ramelteon, tasimelteon, and agomelatine) and Parkinson's disease was evaluated by the reporting odds ratio. Upon analyzing the data from all patients registered in the FAERS, ramelteon (ROR: 0.66, 95% confidence interval [95% CI]: 0.51-0.84) and tasimelteon (ROR: 0.49, 95% CI: 0.38-0.62) showed negative correlations with Parkinson's disease. Conversely, only agomelatine was positively correlated with Parkinson's disease (ROR: 2.63, 95% CI: 2.04-3.40). These results suggest that among the melatonin receptor agonists, ramelteon and tasimelteon are negatively correlated with Parkinson's disease. In contrast, agomelatine was shown to be positively correlated with Parkinson's disease. These results should be used in research to develop drugs for the treatment of Parkinson's disease, fully considering the limitations of the spontaneous reporting system.