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Liu AC, Shen Y, Serbinski CR, He H, Roman D, Endale M, Aschbacher-Smith L, King KA, Granadillo JL, López I, Krueger DA, Dye TJ, Smith DF, Hogenesch JB, Prada CE. Clinical and functional studies of MTOR variants in Smith-Kingsmore syndrome reveal deficits of circadian rhythm and sleep-wake behavior. HGG ADVANCES 2024; 5:100333. [PMID: 39030910 PMCID: PMC11342114 DOI: 10.1016/j.xhgg.2024.100333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/13/2024] [Accepted: 07/15/2024] [Indexed: 07/22/2024] Open
Abstract
Heterozygous de novo or inherited gain-of-function mutations in the MTOR gene cause Smith-Kingsmore syndrome (SKS). SKS is a rare autosomal dominant condition, and individuals with SKS display macrocephaly/megalencephaly, developmental delay, intellectual disability, and seizures. A few dozen individuals are reported in the literature. Here, we report a cohort of 28 individuals with SKS that represent nine MTOR pathogenic variants. We conducted a detailed natural history study and found pathophysiological deficits among individuals with SKS in addition to the common neurodevelopmental symptoms. These symptoms include sleep-wake disturbance, hyperphagia, and hyperactivity, indicative of homeostatic imbalance. To characterize these variants, we developed cell models and characterized their functional consequences. We showed that these SKS variants display a range of mechanistic target of rapamycin (mTOR) activities and respond to the mTOR inhibitor, rapamycin, differently. For example, the R1480_C1483del variant we identified here and the previously known C1483F are more active than wild-type controls and less responsive to rapamycin. Further, we showed that SKS mutations dampened circadian rhythms and low-dose rapamycin improved the rhythm amplitude, suggesting that optimal mTOR activity is required for normal circadian function. As SKS is caused by gain-of-function mutations in MTOR, rapamycin was used to treat several patients. While higher doses of rapamycin caused delayed sleep-wake phase disorder in a subset of patients, optimized lower doses improved sleep. Our study expands the clinical and molecular spectrum of SKS and supports further studies for mechanism-guided treatment options to improve sleep-wake behavior and overall health.
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Affiliation(s)
- Andrew C Liu
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA.
| | - Yang Shen
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Carolyn R Serbinski
- Divisions of Human Genetics, Neurology, Immunobiology, Pediatric Otolaryngology, and Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Division of Genetics, Genomics & Metabolism, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA
| | - Hongzhi He
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Destino Roman
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Mehari Endale
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Lindsey Aschbacher-Smith
- Divisions of Human Genetics, Neurology, Immunobiology, Pediatric Otolaryngology, and Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Katherine A King
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Jorge L Granadillo
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Isabel López
- Pediatric Neurology Unit, Department of Neurology, Clínica Las Condes, Santiago, Chile
| | - Darcy A Krueger
- Divisions of Human Genetics, Neurology, Immunobiology, Pediatric Otolaryngology, and Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Thomas J Dye
- Divisions of Human Genetics, Neurology, Immunobiology, Pediatric Otolaryngology, and Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - David F Smith
- Divisions of Pediatric Otolaryngology and Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; The Sleep Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; The Center for Circadian Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Otolaryngology Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - John B Hogenesch
- Divisions of Human Genetics, Neurology, Immunobiology, Pediatric Otolaryngology, and Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Carlos E Prada
- Divisions of Human Genetics, Neurology, Immunobiology, Pediatric Otolaryngology, and Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Division of Genetics, Genomics & Metabolism, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA; Department of Pediatrics, Feinberg School of Medicine of Northwestern University, Chicago, IL 60611, USA.
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Bhor S, Tonny SH, Dinesh S, Sharma S. Computational screening of damaging nsSNPs in human SOD1 genes associated with amyotrophic lateral sclerosis identifies destabilising effects of G38R and G42D mutations through in silico evaluation. In Silico Pharmacol 2024; 12:20. [PMID: 38559706 PMCID: PMC10973320 DOI: 10.1007/s40203-024-00191-7] [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: 12/06/2023] [Accepted: 01/14/2024] [Indexed: 04/04/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS), a complicated neurodegenerative disorder affected by hereditary and environmental variables, is a condition. In this study, the genetic makeup of ALS is investigated, with a focus on the SOD1 gene's single-nucleotide polymorphisms (SNPs) and their ability to affect disease risk. Eleven high-risk missense variations that may impair the functionality of the SOD1 protein were discovered after a thorough examination of SNPs in the SOD1 gene. These mutations were chosen using a variety of prediction approaches, highlighting their importance in the aetiology of ALS. Notably, it was discovered that the stability of the SOD1 wild-type protein structure was compromised by the G38R and G42D SOD1 variants. Additionally, Edaravone, a possible ALS medication, showed a greater affinity for binding mutant SOD1 structures, pointing to potential personalised treatment possibilities. The high-risk SNPs discovered in this investigation seem to have functional effects, especially on the stability of proteins and their interactions with other molecules. This study clarifies the complex genetics of ALS and offers insights into how these genetic variations may affect the effectiveness of therapeutic interventions, particularly in the context of edaravone. In this study advances our knowledge of the genetic mechanisms causing ALS vulnerability and prospective therapeutic strategies. Future studies are necessary to confirm these results and close the gap between individualised clinical applications and improved ALS care.
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Affiliation(s)
- Samiksha Bhor
- Department of Bioinformatics, BioNome, Bengaluru, Karnataka 560043 India
| | - Sadia Haque Tonny
- Department of Plant Pathology, Faculty of Agriculture, Bangladesh Agricultural University, Mymensingh, 2202 Bangladesh
| | - Susha Dinesh
- Department of Bioinformatics, BioNome, Bengaluru, Karnataka 560043 India
| | - Sameer Sharma
- Department of Bioinformatics, BioNome, Bengaluru, Karnataka 560043 India
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Simonelli V, Ferrari AR, Battini R, Brovedani P, Bartolini E. Midline non-ictal rhythmic waveforms as possible electroencephalographic biomarkers of Smith-Klingsmore syndrome in children. Clin Neurophysiol Pract 2024; 9:102-105. [PMID: 38495955 PMCID: PMC10940733 DOI: 10.1016/j.cnp.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 01/20/2024] [Accepted: 02/02/2024] [Indexed: 03/19/2024] Open
Abstract
Introduction Pathogenic variants of the MTOR gene result in the Smith-Kingsmore syndrome, whose phenotypical spectrum includes facial dysmorphisms and neurological features. Expressivity is variable, patients exhibit a combination of intellectual disability, macrocephaly and epilepsy. The diagnosis can be missed, failing to detect the causative pathogenic mutation in patients with somatic mosaicism or even skipping to analyze MTOR when the phenotype is not completely expressed. Case study Herein, we report two children harboring the same MTOR recurring mutation (c.5395G>A/p.Glu1799Lys) whose EEG displayed a peculiar combination of midline rhythmic waveforms and asynchronous spike-and-wave discharges with anterior fast activity in sleep and wake. Conclusion: We suggest these features might be considered as possible hallmarks of the syndrome and could aid to expedite the diagnosis when the phenotype is incomplete.
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Affiliation(s)
- Valerio Simonelli
- IRCCS Stella Maris Foundation, Department of Developmental Neuroscience, Pisa, Italy
| | - Anna Rita Ferrari
- IRCCS Stella Maris Foundation, Department of Developmental Neuroscience, Pisa, Italy
| | - Roberta Battini
- IRCCS Stella Maris Foundation, Department of Developmental Neuroscience, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Paola Brovedani
- IRCCS Stella Maris Foundation, Department of Developmental Neuroscience, Pisa, Italy
| | - Emanuele Bartolini
- IRCCS Stella Maris Foundation, Department of Developmental Neuroscience, Pisa, Italy
- Tuscany PhD Programme in Neurosciences, University of Florence, Italy
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Tamir S, Dye TJ, Witt RM. Sleep and Circadian Disturbances in Children With Neurodevelopmental Disorders. Semin Pediatr Neurol 2023; 48:101090. [PMID: 38065637 DOI: 10.1016/j.spen.2023.101090] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 12/18/2023]
Abstract
Sleep problems are highly prevalent in those with neurodevelopmental disorders (NDDs). We propose this is secondary to multiple factors that directly and indirectly negatively impact sleep and circadian processes in those with NDDs, which in turn, further perturbs development, resulting in a "developmental and sleep/circadian-related encephalopathy." In this review, we discuss select NDDs with known or suspected sleep and circadian phenotypes. We also highlight important considerations when evaluating and treating sleep and circadian disorders in these populations.
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Affiliation(s)
- Sharon Tamir
- University of Cincinnati College of Medicine, Cincinnati, OH; Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Thomas J Dye
- Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Division of Pulmonary Medicine and the Sleep Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Center for Circadian Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Rochelle M Witt
- Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Division of Pulmonary Medicine and the Sleep Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Center for Circadian Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH.
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Bhadra S, Xu YJ. TTT (Tel2-Tti1-Tti2) Complex, the Co-Chaperone of PIKKs and a Potential Target for Cancer Chemotherapy. Int J Mol Sci 2023; 24:ijms24098268. [PMID: 37175973 PMCID: PMC10178989 DOI: 10.3390/ijms24098268] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 04/27/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
The heterotrimeric Tel2-Tti1-Tti2 or TTT complex is essential for cell viability and highly observed in eukaryotes. As the co-chaperone of ATR, ATM, DNA-PKcs, mTOR, SMG1, and TRRAP, the phosphatidylinositol 3-kinase-related kinases (PIKKs) and a group of large proteins of 300-500 kDa, the TTT plays crucial roles in genome stability, cell proliferation, telomere maintenance, and aging. Most of the protein kinases in the kinome are targeted by co-chaperone Cdc37 for proper folding and stability. Like Cdc37, accumulating evidence has established the mechanism by which the TTT interacts with chaperone Hsp90 via R2TP (Rvb1-Rvb2-Tah1-Pih1) complex or other proteins for co-translational maturation of the PIKKs. Recent structural studies have revealed the α-solenoid structure of the TTT and its interactions with the R2TP complex, which shed new light on the co-chaperone mechanism and provide new research opportunities. A series of mutations of the TTT have been identified that cause disease syndrome with neurodevelopmental defects, and misregulation of the TTT has been shown to contribute to myeloma, colorectal, and non-small-cell lung cancers. Surprisingly, Tel2 in the TTT complex has recently been found to be a target of ivermectin, an antiparasitic drug that has been used by millions of patients. This discovery provides mechanistic insight into the anti-cancer effect of ivermectin and thus promotes the repurposing of this Nobel-prize-winning medicine for cancer chemotherapy. Here, we briefly review the discovery of the TTT complex, discuss the recent studies, and describe the perspectives for future investigation.
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Affiliation(s)
- Sankhadip Bhadra
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Yong-Jie Xu
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
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Kamble VS, Pachpor TA, Khandagale SB, Wagh VV, Khare SP. Translation initiation and dysregulation of initiation factors in rare diseases. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Xiao F, Zhou Z, Song X, Gan M, Long J, Verkhivker G, Hu G. Dissecting mutational allosteric effects in alkaline phosphatases associated with different Hypophosphatasia phenotypes: An integrative computational investigation. PLoS Comput Biol 2022; 18:e1010009. [PMID: 35320273 PMCID: PMC8979438 DOI: 10.1371/journal.pcbi.1010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 04/04/2022] [Accepted: 03/10/2022] [Indexed: 11/18/2022] Open
Abstract
Hypophosphatasia (HPP) is a rare inherited disorder characterized by defective bone mineralization and is highly variable in its clinical phenotype. The disease occurs due to various loss-of-function mutations in ALPL, the gene encoding tissue-nonspecific alkaline phosphatase (TNSALP). In this work, a data-driven and biophysics-based approach is proposed for the large-scale analysis of ALPL mutations-from nonpathogenic to severe HPPs. By using a pipeline of synergistic approaches including sequence-structure analysis, network modeling, elastic network models and atomistic simulations, we characterized allosteric signatures and effects of the ALPL mutations on protein dynamics and function. Statistical analysis of molecular features computed for the ALPL mutations showed a significant difference between the control, mild and severe HPP phenotypes. Molecular dynamics simulations coupled with protein structure network analysis were employed to analyze the effect of single-residue variation on conformational dynamics of TNSALP dimers, and the developed machine learning model suggested that the topological network parameters could serve as a robust indicator of severe mutations. The results indicated that the severity of disease-associated mutations is often linked with mutation-induced modulation of allosteric communications in the protein. This study suggested that ALPL mutations associated with mild and more severe HPPs can exert markedly distinct effects on the protein stability and long-range network communications. By linking the disease phenotypes with dynamic and allosteric molecular signatures, the proposed integrative computational approach enabled to characterize and quantify the allosteric effects of ALPL mutations and role of allostery in the pathogenesis of HPPs.
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Affiliation(s)
- Fei Xiao
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Ziyun Zhou
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Xingyu Song
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai, China
| | - Mi Gan
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Jie Long
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Gennady Verkhivker
- Department of Computational and Data Sciences, Chapman University, One University Drive, Orange, California, United States of America
- Department of Biomedical and Pharmaceutical Sciences, Chapman University Pharmacy School 9401 Jeronimo Rd, Irvine, California, United States of America
| | - Guang Hu
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
- * E-mail:
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Izumi R, Hino M, Nagaoka A, Shishido R, Kakita A, Hoshino M, Kunii Y, Yabe H. Dysregulation of DPYSL2 expression by mTOR signaling in schizophrenia: Multi-level study of postmortem brain. Neurosci Res 2021; 175:73-81. [PMID: 34543692 DOI: 10.1016/j.neures.2021.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 01/26/2023]
Abstract
The mechanistic target of rapamycin (mTOR)-signaling and dihydropyrimidinase-like 2 (DPYSL2), which are increasingly gaining attention as potential therapeutic targets for schizophrenia, are connected via Cap-dependent translation of the 5'TOP motif. We quantified the expression of molecules constituting the mTOR-signaling and DPYSL2 in the prefrontal cortex (PFC) and superior temporal gyrus (STG) of postmortem brain tissue samples from 24 patients with schizophrenia and 32 control individuals and conducted association analysis to examine abnormal regulation of DPYSL2 expression by the mTOR-signaling in schizophrenia. The average ribosomal protein S6 (S6) levels in the PFC and STG were lower in patients with schizophrenia (p < 0.01). DPYSL2 expression showed a significant positive correlation with phospho-S6 expression levels, which were effectors of mTOR translational regulation, and the correlation slope between phospho-S6 and DPYSL2 expressions differed between cases and controls. Association analyses of these mTOR-signaling and DPYSL2 alterations with genetic polymorphisms and the clinical profile suggested that certain genetic variants of DPYSL2 require high mTOR-signaling activity. Thus, the findings confirmed decreased S6 expression levels in schizophrenia and supported the relationship between the mTOR-signaling and DPYSL2 via 5'TOP Cap-dependent translation, thus providing insights connecting the two major schizophrenia treatment strategies associated with the mTOR-signaling and DPYSL2.
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Affiliation(s)
- Ryuta Izumi
- Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Psychology, Takeda General Hospital, Aizuwakamatu, Japan
| | - Mizuki Hino
- Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Disaster Psychiatry, International Research Institute of Disaster Science, Tohoku University, Sendai, Japan
| | - Atsuko Nagaoka
- Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Risa Shishido
- Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Yasuto Kunii
- Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Disaster Psychiatry, International Research Institute of Disaster Science, Tohoku University, Sendai, Japan.
| | - Hirooki Yabe
- Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan
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