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Qian R, Zhao X, Lyu D, Xu Q, Yuan K, Luo X, Wang W, Wang Y, Liu Y, Cheng Y, Tan Y, Mou F, Yuan C, Yu S. Identification of Causal Genes and Potential Drug Targets for Restless Legs Syndrome: A Comprehensive Mendelian Randomization Study. Pharmaceuticals (Basel) 2024; 17:1626. [PMID: 39770468 PMCID: PMC11728827 DOI: 10.3390/ph17121626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2024] [Revised: 11/22/2024] [Accepted: 11/28/2024] [Indexed: 01/16/2025] Open
Abstract
Background: Restless legs syndrome (RLS) is a common sensorimotor sleep disorder that affects sleep quality of life. Much effort has been made to make progress in RLS pharmacotherapy; however, patients with RLS still report poor long-term symptom control. Methods: Comprehensive Mendelian randomization (MR) was performed to search for potential causal genes and drug targets using the cis-pQTL and RLS GWAS data. Robustness was validated using the summary-based Mendelian randomization (SMR) method and co-localization analysis. Further evidence of pleiotropy of the target genes and their potential side effects was provided by phenome-wide MR analysis (MR-PheWAS). Finally, molecular docking simulations were conducted on drug candidates corresponding to these targets, which revealed promising binding affinities and interaction patterns and underscored the druggable potential of the target gene. All of the analyses above were conducted in the context of Homo sapiens. Results:MAN1A2 showed a statistically significant result in the MR analysis, which was validated through SMR and co-localization analysis. The MR-PheWAS showed a low probability of pleiotropy and prospective side effects. Molecular docking was used to visualize the binding structure and fine affinity for MAN1A2 and the drugs predicted by DSigDB. Conclusions: Our study provides comprehensive evidence supporting MAN1A2 as a promising causal gene and therapeutic target for RLS, offering insights into the underlying molecular mechanisms and paving the way for future drug development efforts.
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Affiliation(s)
- Ruiyi Qian
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Xue Zhao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Dongbin Lyu
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Qingqing Xu
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Kai Yuan
- State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, Institute of Digestive Disease, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR 999077, China;
| | - Xin Luo
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Wanying Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Yang Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Yutong Liu
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Yu Cheng
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Yingting Tan
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Fan Mou
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Chengmei Yuan
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
| | - Shunying Yu
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; (R.Q.); (X.Z.); (D.L.); (Q.X.); (X.L.); (W.W.); (Y.W.); (Y.L.); (Y.C.); (Y.T.); (F.M.)
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Singh H, Baker FC, Ojile J, Adlou B, Kolotovska V, Rigot SK, Charlesworth JD. Efficacy and safety of TOMAC for treatment of medication-naïve and medication-refractory restless legs syndrome: A randomized clinical trial and meta-analysis. Sleep Med 2024; 122:141-148. [PMID: 39173210 PMCID: PMC11414842 DOI: 10.1016/j.sleep.2024.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/29/2024] [Accepted: 08/16/2024] [Indexed: 08/24/2024]
Abstract
OBJECTIVE/BACKGROUND There is a significant unmet need for safe and effective nonpharmacological therapies for restless legs syndrome (RLS). The objective was to evaluate the efficacy and safety of tonic motor activation (TOMAC) in patients with RLS. PATIENTS/METHODS A multicenter, randomized, participant-blinded, sham-controlled trial enrolled 45 adults with primary moderate-to-severe RLS who were either medication-naïve (n = 20) or medication-refractory (n = 25). Participants were 1:1 randomized to TOMAC (n = 22) or sham (n = 23) for two weeks and instructed to self-administer 30-min TOMAC sessions when they experienced RLS symptoms. The primary outcome was mean change in International RLS Study Group Rating Scale (IRLS) total score. A subsequent meta-analysis included the present trial and a previous randomized clinical trial that enrolled medication-naïve RLS patients. RESULTS IRLS reduction was significantly greater for TOMAC than sham (TOMAC -6.59 vs. sham -2.17; mean difference (MD) = -4.42; 95 % confidence interval [CI] -1.57 to -7.26; p = 0.0040). Subgroup analysis showed similar IRLS mean difference for medication-refractory (MD = -4.50; p = 0.02) and medication-naïve (MD = -4.40; p = 0.08) cohorts, which was significantly different from sham only for the medication-refractory cohort. Meta-analysis of combined data from 33 medication-naïve RLS patients showed a significant reduction in mean IRLS score after two weeks for TOMAC compared to sham (MD = -4.30; 95 % CI -1.36 to -7.24; p = 0.004). CONCLUSIONS The present trial confirmed previous reports documenting efficacy and safety of TOMAC in refractory RLS and indicated similar effect sizes in refractory versus naïve subgroups. The meta-analysis demonstrated that TOMAC significantly improves RLS symptoms in naïve participants.
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Affiliation(s)
- Haramandeep Singh
- Sleep Medicine Specialists of California, 5201 Norris Canyon Rd, Suite 120, San Ramon, CA 94583, USA.
| | - Fiona C Baker
- Center for Health Sciences, SRI International, 333 Ravenswood Ave, Menlo Park, CA 94025, USA.
| | - Joseph Ojile
- Clayton Sleep Institute, LLC, 11188 Tesson Ferry Road, Suite 100, St. Louis, MO 63123 USA.
| | - Bahman Adlou
- Noctrix Health, Inc., 6700 Koll Center Pkwy, Suite 310, Pleasanton, CA, USA
| | | | - Stephanie K Rigot
- Noctrix Health, Inc., 6700 Koll Center Pkwy, Suite 310, Pleasanton, CA, USA
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Earley CJ, García-Borreguero D, Falone M, Winkelman JW. Clinical efficacy and safety of intravenous ferric carboxymaltose for treatment of restless legs syndrome: a multicenter, randomized, placebo-controlled clinical trial. Sleep 2024; 47:zsae095. [PMID: 38625730 DOI: 10.1093/sleep/zsae095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/03/2023] [Indexed: 04/17/2024] Open
Abstract
STUDY OBJECTIVES Iron therapy is associated with improvements in restless legs syndrome (RLS). This multicenter, randomized, double-blind study evaluated the effect of intravenous ferric carboxymaltose (FCM) on RLS. METHODS A total of 209 adult patients with a baseline International RLS (IRLS) score ≥ 15 were randomized (1:1) to FCM (750 mg/15 mL) or placebo on study days 0 and 5. Ongoing RLS medication was tapered starting on Day 5, with the goal of discontinuing treatment or achieving the lowest effective dose. Co-primary efficacy endpoints were changed from baseline in IRLS total score and the proportion of patients rated as much/very much improved on the Clinical Global Impression (CGI)-investigator (CGI-I) scale at day 42 in the "As-Treated" population. RESULTS The "As-Treated" population comprised 107 FCM and 101 placebo recipients; 88 (82.2%) and 68 (67.3%), respectively, completed the day 42 assessment. The IRLS score reduction was significantly greater with FCM versus placebo: least-squares mean (95% confidence interval [CI]) -8.0 (-9.5, -6.4) versus -4.8 (-6.4, -3.1); p = .0036. No significant difference was observed in the proportion of FCM (35.5%) and placebo (28.7%) recipients with a CGI-I response (odds ratio 1.37 [95% CI: 0.76, 2.47]; p = .2987). Fewer patients treated with FCM (32.7%) than placebo (59.4%) received RLS interventions between day 5 and study end (p = .0002). FCM was well tolerated. CONCLUSIONS The IRLS score improved with intravenous FCM versus placebo, although the combination of both co-primary endpoints was not met. Potential methodological problems in the study design are discussed.
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Affiliation(s)
| | | | - Mark Falone
- American Regent, Inc., Clinical Research and Development, Shirley, NY, USA
| | - John W Winkelman
- Departments of Psychiatry and Neurology, Massachusetts General Hospital, Boston, MA, USA
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Walters AS, Li Y, Koo BB, Ondo WG, Weinstock LB, Champion D, Afrin LB, Karroum EG, Bagai K, Spruyt K. Review of the role of the endogenous opioid and melanocortin systems in the restless legs syndrome. Brain 2024; 147:26-38. [PMID: 37633259 PMCID: PMC10796165 DOI: 10.1093/brain/awad283] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/23/2023] [Accepted: 08/01/2023] [Indexed: 08/28/2023] Open
Abstract
Restless legs syndrome (RLS) is responsive to opioid, dopaminergic and iron-based treatments. Receptor blocker studies in RLS patients suggest that the therapeutic efficacy of opioids is specific to the opioid receptor and mediated indirectly through the dopaminergic system. An RLS autopsy study reveals decreases in endogenous opioids, β-endorphin and perhaps Met-enkephalin in the thalamus of RLS patients. A total opioid receptor knock-out (mu, delta and kappa) and a mu-opioid receptor knock-out mouse model of RLS show circadian motor changes akin to RLS and, although both models show sensory changes, the mu-opioid receptor knock mouse shows circadian sensory changes closest to those seen in idiopathic RLS. Both models show changes in striatal dopamine, anaemia and low serum iron. However, only in the total receptor knock-out mouse do we see the decreases in serum ferritin that are normally found in RLS. There are also decreases in serum iron when wild-type mice are administered a mu-opioid receptor blocker. In addition, the mu-opioid receptor knock-out mouse also shows increases in striatal zinc paralleling similar changes in RLS. Adrenocorticotropic hormone and α-melanocyte stimulating hormone are derived from pro-opiomelanocortin as is β-endorphin. However, they cause RLS-like symptoms and periodic limb movements when injected intraventricularly into rats. These results collectively suggest that an endogenous opioid deficiency is pathogenetic to RLS and that an altered melanocortin system may be causal to RLS as well.
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Affiliation(s)
- Arthur S Walters
- Sleep Division, Department of Neurology, Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Yuqing Li
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Brian B Koo
- Sleep Medicine Laboratory, VA Connecticut Health Care System, West Haven, CT 06516, USA
- Yale Center for Restless Legs Syndrome, Yale School of Medicine, New Haven, CT 06520, USA
| | - William G Ondo
- Department of Neurology, Methodist Hospital, Weill Cornell Medical School, Houston, TX 77030, USA
| | - Leonard B Weinstock
- Department of Internal Medicine, Washington University School of Medicine, St.Louis, MO 63130, USA
| | - David Champion
- Sydney Children's Hospital, Department of Pain Medicine, Randwick, NSW 2031, Australia
| | - Lawrence B Afrin
- Hematology/Oncology, AIM Center for Personalized Medicine, Purchase, NY 10577, USA
| | - Elias G Karroum
- Department of Neurology and Rehabilitation Medicine, The George Washington University School of Medicine and Health Sciences, George Washington University, Washington, D.C. 20052, USA
| | - Kanika Bagai
- Sleep Division, Department of Neurology, Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Karen Spruyt
- Université Paris Cité, NeuroDiderot Inserm, Paris 75019, France
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