1
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Oswalia J, Singh S, Gautam V, Arya R. Altered Autophagic Flux in GNE mutant cells of Indian Origin: potential drug target for GNE Myopathy. Exp Cell Res 2024:114118. [PMID: 38852763 DOI: 10.1016/j.yexcr.2024.114118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/11/2024]
Abstract
Autophagy phenomenon in the cell maintains proteostasis balance by eliminating damaged organelles and protein aggregates. Imbalance in autophagic flux may cause accumulation of protein aggregates in various neurodegenerative disorders. Regulation of autophagy by either calcium or chaperone play a key role in the removal of protein aggregates from the cell. The neuromuscular rare genetic disorder, GNE Myopathy, is characterized by accumulation of rimmed vacuoles having protein aggregates of β-amyloid and tau that may result from altered autophagic flux. In the present study, the autophagic flux was deciphered in HEK cell-based model for GNE Myopathy harbouring GNE mutations of Indian origin. The refolding activity of HSP70 chaperone was found to be reduced in GNE mutant cells compared to wild type controls. The autophagic markers LC3II/I ratio was altered with increased number of autophagosome formation in GNE mutant cells compared to wild type cells. The cytosolic calcium levels were also increased in GNE mutant cells of Indian origin. Interestingly, treatment of GNE mutant cells with HSP70 activator, BGP-15, restored the expression and refolding activity of HSP70 along with autophagosome formation. Treatment with calcium chelator, BAPTA-AM restored the cytoplasmic calcium levels and autophagosome formation but not LC3II/I ratio significantly. Our study provides insights towards GNE mutation specific response for autophagy regulation and opens up a therapeutic advancement area in calcium signalling and HSP70 function for GNE related Myopathy.
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Affiliation(s)
- Jyoti Oswalia
- School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067.
| | - Shagun Singh
- School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067.
| | - Vaishali Gautam
- School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067.
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067.
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2
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Mashangva F, Oswalia J, Singh S, Arya R. Potential small effector molecules restoring cellular defects due to sialic acid biosynthetic enzyme deficiency: Pathological relevance to GNE myopathy. Biochem Pharmacol 2024; 223:116199. [PMID: 38604256 DOI: 10.1016/j.bcp.2024.116199] [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: 10/29/2023] [Revised: 02/21/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
GNEM (GNE Myopathy) is a rare neuromuscular disease caused due to biallelic mutations in sialic acid biosynthetic GNE enzyme (UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine Kinase). Recently direct or indirect role of GNE in other cellular functions have been elucidated. Hyposialylation of IGF-1R leads to apoptosis due to mitochondrial dysfunction while hyposialylation of β1 integrin receptor leads to altered F-actin assembly, disrupted cytoskeletal organization and slow cell migration. Other cellular defects in presence of GNE mutation include altered ER redox state and chaperone expression such as HSP70 or PrdxIV. Currently, there is no cure to treat GNEM. Possible therapeutic trials focus on supplementation with sialic acid, ManNAc, sialyllactose and gene therapy that slows the disease progression. In the present study, we analyzed the effect of small molecules like BGP-15 (HSP70 modulator), IGF-1 (IGF-1R ligand) and CGA (cofilin activator) on cellular phenotypes of GNE heterozygous knock out L6 rat skeletal muscle cell line (SKM‑GNEHz). Treatment with BGP-15 improved GNE epimerase activity by 40 % and reduced ER stress by 45 % for SKM‑GNEHz. Treatment with IGF-1 improved epimerase activity by 37.5 %, F-actin assembly by 100 %, cell migration upto 36 % (36 h) and atrophy by 0.44-fold for SKM‑GNEHz. Treatment with CGA recovered epimerase activity by 49 %, F-actin assembly by 132 % and cell migration upto 41 % (24 h) in SKM‑GNEHz. Our study shows that treatment with these small effector molecules reduces the detrimental phenotype observed in SKM‑GNEHz, thereby, providing insights into potential therapeutic targets for GNEM.
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Affiliation(s)
| | - Jyoti Oswalia
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Shagun Singh
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
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3
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Abdel-Naim AB, Kumar P, Bazuhair MA, Rizg WY, Niyazi HA, Alkuwaity K, Niyazi HA, Alharthy SA, Harakeh S, Haque S, Prakash A, Kumar V. Computational insights into dynamics and conformational stability of N-acetylmannosamine kinase mutations. J Biomol Struct Dyn 2024:1-11. [PMID: 38502682 DOI: 10.1080/07391102.2024.2323702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 02/21/2024] [Indexed: 03/21/2024]
Abstract
The activity of UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE) is essential for the biosynthesis of sialic acid, which is involved in cellular processes in health and diseases. GNE contains an N-terminal epimerase domain and a C-terminal kinase domain (N-acetylmannosamine kinase, MNK). Mutations of the GNE protein led to hypoactivity of the enzyme and cause sialurea or autosomal recessive inclusion body myopathy/Nonaka myopathy. Here, we used all-atom molecular dynamics (MD) simulations to comprehend the folding, dynamics and conformational stability of MNK variants, including the wild type (WT) and three mutants (H677R, V696M and H677R/V696M). The deleterious and destabilizing nature of MNK mutants were predicted using different prediction tools. Results predicted that mutations modulate the stability, flexibility and function of MNK. The effect of mutations on the conformational stability and dynamics of MNK was next studied through the free-energy landscape (FEL), hydrogen-bonds and secondary structure changes. The FEL results show that the mutations interfere with various conformational transitions in both WT and mutants, exposing the structural underpinnings of protein destabilization and unfolding brought on by mutation. We discover that, when compared to the other two mutations, V696M and H677R/V696M, H677R has the most harmful effects. These findings have a strong correlation with published experimental studies that demonstrate how these mutations disrupt MNK activity. Hence, this computational study describes the structural details to unravel the mutant effects at the atomistic resolution and has implications for understanding the GNE's physiological and pathological role.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ashraf B Abdel-Naim
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Mohamed Saeed Tamer Chair for Pharmaceutical Industries, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Center of Excellence for Drug Research and Pharmaceutical Industries, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Pawan Kumar
- School of Computational & Integrative Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Mohammed A Bazuhair
- Center of Excellence for Drug Research and Pharmaceutical Industries, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Clinical Pharmacology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Waleed Y Rizg
- Mohamed Saeed Tamer Chair for Pharmaceutical Industries, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Center of Excellence for Drug Research and Pharmaceutical Industries, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hatoon A Niyazi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Khalil Alkuwaity
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Vaccines and Immunotherapy Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hanouf A Niyazi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Saif A Alharthy
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Toxicology and Forensic Sciences Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Steve Harakeh
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Yousef Abdul Latif Jameel Scientific Chair of Prophetic Medicine Application, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Health Sciences, Jazan University, Jazan, Saudi Arabia
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut, Lebanon
- Centre of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
| | - Amresh Prakash
- Amity Institute of Integrative Sciences and Health, Amity University Haryana, Gurgaon, India
| | - Vijay Kumar
- Amity Institute of Neuropsychology & Neurosciences, Amity University, Noida, India
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4
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Yadav R, Devi SS, Oswalia J, Ramalingam S, Arya R. Role of HSP70 chaperone in protein aggregate phenomenon of GNE mutant cells: Therapeutic lead for GNE Myopathy. Int J Biochem Cell Biol 2022; 149:106258. [PMID: 35777599 DOI: 10.1016/j.biocel.2022.106258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/04/2022] [Accepted: 06/25/2022] [Indexed: 10/17/2022]
Abstract
Limited treatment options and research in understanding the pathomechanisms of rare diseases has raised concerns about their therapeutic development. One such poorly understood ultra-rare neuromuscular disorder is GNE Myopathy (GNEM) which is caused due to mutation in key sialic acid biosynthetic enzyme, GNE. Treatment with sialic acid or its derivatives/precursors slows the disease progression, but curative strategies need to be explored further. Pathologically, muscle biopsy samples of GNEM patients reveal rimmed vacuole formation due to aggregation of β-amyloid, Tau, presenilin proteins with unknown mechanism. The present study aims to understand the mechanism of protein aggregate formation in GNE mutant cells to decipher role of chaperones in disease phenotype. The pathologically relevant GNE mutations expressed as recombinant proteins in HEK cells was used as a model system for GNEM to estimate extent of protein aggregation. We identified HSP70, a chaperone, as binding partner of GNE. Downregulation of HSP70 with altered BAG3, JNK, BAX expression levels was observed in GNE mutant cells. The cell apoptosis was observed in GNE mutation specific manner. An activator of HSP70 chaperone, BGP-15, rescued the phenotypic defects due to GNE mutation, thereby, reducing protein aggregation significantly. The results were further validated in rat skeletal muscle cell lines carrying single Gne allele. Our study suggests that HSP70 activators can be a promising therapeutic target in the treatment of ultra-rare GNE Myopathy disease.
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Affiliation(s)
- Rashmi Yadav
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
| | | | - Jyoti Oswalia
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
| | | | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India; Special Center for Systems Medicine, Jawaharlal Nehru University, New Delhi 110067, India.
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5
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The role of amyloid β in the pathological mechanism of GNE myopathy. Neurol Sci 2022; 43:6309-6321. [PMID: 35904705 PMCID: PMC9616754 DOI: 10.1007/s10072-022-06301-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/21/2022] [Indexed: 11/18/2022]
Abstract
GNE myopathy is a hereditary muscle disorder characterized by muscle atrophy and weakness initially involving the lower distal extremities. The treatment of GNE myopathy mainly focuses on a sialic acid deficiency caused by a mutation in the GNE gene, but it has not achieved the expected effect. The main pathological features of GNE myopathy are myofiber atrophy and rimmed vacuoles, including accumulation of amyloid β, which is mainly found in atrophic muscle fibers. Although the role of amyloid β and other misfolded proteins on the nervous system has been widely recognized, the cause and process of the formation of amyloid β in the pathological process of GNE myopathy are unclear. In addition, amyloid β has been reported to be linked to quality control mechanisms of proteins, such as molecular chaperones, the ubiquitin–proteasome system, and the autophagy-lysosome system. Herein, we summarize the possible reasons for amyloid β deposition and illustrate amyloid β-mediated events in the cells and their role in muscle atrophy in GNE myopathy. This review represents an overview of amyloid β and GNE myopathy that could help identify a potential mechanism and thereby a plausible therapeutic for the disease.
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6
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Functional characterization of GNE mutations prevalent in Asian subjects with GNE myopathy, an ultra-rare neuromuscular disorder. Biochimie 2022; 199:36-45. [DOI: 10.1016/j.biochi.2022.03.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 03/25/2022] [Accepted: 03/30/2022] [Indexed: 12/19/2022]
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7
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Zhang KY, Duan HQ, Li QX, Luo YB, Bi FF, Huang K, Yang H. Expanding the clinicopathological-genetic spectrum of GNE myopathy by a Chinese neuromuscular centre. J Cell Mol Med 2021; 25:10494-10503. [PMID: 34676965 PMCID: PMC8581342 DOI: 10.1111/jcmm.16978] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/19/2021] [Accepted: 09/24/2021] [Indexed: 12/16/2022] Open
Abstract
GNE myopathy is a heterogeneous group of ultrarare neuromuscular disorders caused by mutations in the GNE gene. An estimated prevalence of 1~21/1,000,000 leads to a deficiency of data and a lack of availability of samples to conduct clinical research on this neuromuscular disorder. Although GNE, which is the mutated gene responsible for the disease, is well known as the key enzyme in the biosynthesis pathway of sialic acid, the clinicopathological-genetic spectrum of GNE mutant patients is still unclear and expanding. This study presents ten unrelated patients with GNE myopathy, discovering five novel missense mutations. Clinical, electrophysiological, imaging, pathological and genetic data are presented in a retrospective manner. Interestingly, several patients in the cohort were found to have peripheral neuropathy and inflammatory cell infiltration in muscle biopsies, which have seldom been reported. This study, conducted by a neuromuscular centre in China, is the first attempt to highlight these abnormal clinicopathological features and associate them with genetic mutations in GNE myopathy.
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Affiliation(s)
- Kai-Yue Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,Clinic Medicine of 8-year Program, Xiangya School of Medicine, Central South University, Changsha, China
| | - Hui-Qian Duan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qiu-Xiang Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yue-Bei Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Fang-Fang Bi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Kun Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
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8
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Chaudhary P, Sharma S, Singh R, Arya R. Elucidation of ER stress and UPR pathway in sialic acid-deficient cells: Pathological relevance to GNEM. J Cell Biochem 2021; 122:1886-1902. [PMID: 34555215 DOI: 10.1002/jcb.30148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 12/31/2022]
Abstract
Accumulation of misfolded proteins in endoplasmic reticulum (ER) generates a stress condition in the cell. The cell combats ER stress by activating unfolded protein response (UPR) and ERAD (ER stress-associated degradation) pathway. Failure to restore favorable folding environment results in cell dysfunction and apoptosis. Various neurodegenerative disorders are characterized by the accumulation of misfolded protein, protein aggregates, and ER stress. GNE myopathy (GNEM) is a neuromuscular disorder pathologically characterized by rimmed vacuole formation due to the accumulation of protein aggregates. More than 200 mutations in key sialic acid biosynthetic enzyme UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) have been identified worldwide in the muscle biopsies of GNE myopathy patients. However, the cellular and molecular pathomechanism leading to the disease ar poorly understood. In the present study, the phenomenon of ER stress has been elucidated in GNE mutant cells overexpressing GNE mutations of Indian origin. The effect of GNE mutations on activation of UPR signaling via inositol-requiring transmembrane kinase/endoribonuclease 1 (IRE-1), protein kinase RNA-like endoplasmic reticulum kinase (PERK), and activating transcription factor-6 (ATF6) were deciphered to understand the effect of GNE mutations on these proteins. GRP78 was upregulated with increased X-box-binding protein-1 (XBP-1) splicing and CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) upregulation leading to increased apoptosis of GNE mutant cells. Insulin-like growth factor 1 (IGF-1) ligand rescued the cells from apoptotic phenotype by supporting cell survival mechanism. Our study indicates a balance of cell death and survival that decides cell fate and offers potential therapeutic targets to combat ER stress in diseases associated with dysfunctional UPR pathway.
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Affiliation(s)
| | - Shweta Sharma
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Reema Singh
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.,Special Centre for Systems Medicine, Jawaharlal Nehru University, New Delhi, India
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Devi SS, Yadav R, Mashangva F, Chaudhary P, Sharma S, Arya R. Generation and Characterization of a Skeletal Muscle Cell-Based Model Carrying One Single Gne Allele: Implications in Actin Dynamics. Mol Neurobiol 2021; 58:6316-6334. [PMID: 34510381 DOI: 10.1007/s12035-021-02549-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 08/28/2021] [Indexed: 12/13/2022]
Abstract
UDP-N-Acetyl glucosamine-2 epimerase/N-acetyl mannosamine kinase (GNE) catalyzes key enzymatic reactions in the biosynthesis of sialic acid. Mutation in GNE gene causes GNE myopathy (GNEM) characterized by adult-onset muscle weakness and degeneration. However, recent studies propose alternate roles of GNE in other cellular processes beside sialic acid biosynthesis, particularly interaction of GNE with α-actinin 1 and 2. Lack of appropriate model system limits drug and treatment options for GNEM as GNE knockout was found to be embryonically lethal. In the present study, we have generated L6 rat skeletal muscle myoblast cell-based model system carrying one single Gne allele where GNE gene is knocked out at exon-3 using AAV mediated SEPT homology recombination (SKM-GNEHz). The cell line was heterozygous for GNE gene with one wild type and one truncated allele as confirmed by sequencing. The phenotype showed reduced GNE epimerase activity with little reduction in sialic acid content. In addition, the heterozygous GNE knockout cells revealed altered cytoskeletal organization with disrupted actin filament. Further, we observed increased levels of RhoA leading to reduced cofilin activity and causing reduced F-actin polymerization. The disturbed signaling cascade resulted in reduced migration of SKM-GNEHz cells. Our study indicates possible role of GNE in regulating actin dynamics and cell migration of skeletal muscle cell. The skeletal muscle cell-based system offers great potential in understanding pathomechanism and target identification for GNEM.
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Affiliation(s)
| | - Rashmi Yadav
- School of Biotechnology, Jawaharlal Nehru University, 110067, New Delhi, India
| | | | - Priyanka Chaudhary
- School of Biotechnology, Jawaharlal Nehru University, 110067, New Delhi, India
| | - Shweta Sharma
- School of Biotechnology, Jawaharlal Nehru University, 110067, New Delhi, India
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, 110067, New Delhi, India. .,Special Centre for Systems Medicine (Concurrent Faculty), Jawaharlal Nehru University, New Mehrauli Road, 110067, New Delhi, India.
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10
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Devi SS, Yadav R, Arya R. Altered Actin Dynamics in Cell Migration of GNE Mutant Cells. Front Cell Dev Biol 2021; 9:603742. [PMID: 33816461 PMCID: PMC8012676 DOI: 10.3389/fcell.2021.603742] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/09/2021] [Indexed: 11/27/2022] Open
Abstract
Cell migration is an essential cellular process that requires coordination of cytoskeletal dynamics, reorganization, and signal transduction. The actin cytoskeleton is central in maintaining the cellular structure as well as regulating the mechanisms of cell motility. Glycosylation, particularly sialylation of cell surface proteins like integrins, regulates signal transduction from the extracellular matrix to the cytoskeletal network. The activation of integrin by extracellular cues leads to recruitment of different focal adhesion complex proteins (Src, FAK, paxillin, etc.) and activates the signal including Rho GTPases for the regulation of actin assembly and disassembly. During cell migration, the assembly and disassembly of actin filament provides the essential force for the cell to move. Abnormal sialylation can lead to actin signaling dysfunction leading to aberrant cell migration, one of the main characteristics of cancer and myopathies. In the present study, we have reported altered F-actin to G-actin ratios in GNE mutated cells. These cells exhibit pathologically relevant mutations of GNE (UDP N-acetylneuraminic 2-epimerase/N-acetylmannosamine kinase), a key sialic acid biosynthetic enzyme. It was found that GNE neither affects the actin polymerization nor binds directly to actin. However, mutation in GNE resulted in increased binding of α-actinin to actin filaments. Further, through confocal imaging, GNE was found to be localized in focal adhesion complex along with paxillin. We further elucidated that mutation in GNE resulted in upregulation of RhoA protein and Cofilin activity is downregulated, which could be rescued with Rhosin and chlorogenic acid, respectively. Lastly, mutant in GNE reduced cell migration as implicated from wound healing assay. Our study indicates that molecules altering Cofilin function could significantly revert the cell migration defect due to GNE mutation in sialic acid-deficient cells. We propose cytoskeletal proteins to be alternate drug targets for disorders associated with GNE such as GNE myopathy.
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Affiliation(s)
| | - Rashmi Yadav
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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Awasthi K, Arya R, Bhattacharya A, Bhattacharya S. The Inherited Neuromuscular Disorder GNE Myopathy: Research to Patient Care. Neurol India 2019; 67:1213-1219. [PMID: 31744945 DOI: 10.4103/0028-3886.271259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Inherited neuromuscular diseases are a heterogeneous group of rare diseases for which the low general awareness leads to frequent misdiagnosis. Advances in DNA sequencing technologies are changing this situation, and it is apparent that these diseases are not as rare as previously thought. Knowledge of the pathogenic variants in patients is helping in research efforts to develop new therapies. Here we present a review of current knowledge in GNE myopathy, a rare neuromuscular disorder caused by mutations in the GNE gene that catalyzes the biosynthesis of sialic acid. The most common initial symptom is foot drop caused by anterior tibialis muscle weakness. There is a progressive wasting of distal skeletal muscles in the lower and upper extremities as well. The quadriceps is relatively spared, which is a distinguishing feature of this disease. The characteristic histological features include autophagic rimmed vacuoles with inclusion bodies. GNE variant analysis of Indian patients has revealed a founder mutation (p.Val727Met) common within the normal Indian populations, especially in the state of Gujurat. We discuss therapeutic options, including metabolite supplementation, pharmacological chaperones, and gene therapy. Initiatives that bring together patients, researchers, and physicians are necessary to improve knowledge and treatment for these rare disorders.
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Affiliation(s)
- Kapila Awasthi
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Alok Bhattacharya
- School of Life Sciences; World without GNE Myopathy, Jawaharlal Nehru University, New Delhi, India
| | - Sudha Bhattacharya
- World without GNE Myopathy, Jawaharlal Nehru University; School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
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12
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Devi S, Yadav R, Chanana P, Arya R. Fighting the Cause of Alzheimer's and GNE Myopathy. Front Neurosci 2018; 12:669. [PMID: 30374284 PMCID: PMC6196280 DOI: 10.3389/fnins.2018.00669] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 09/06/2018] [Indexed: 12/12/2022] Open
Abstract
Age is the common risk factor for both neurodegenerative and neuromuscular diseases. Alzheimer disease (AD), a neurodegenerative disorder, causes dementia with age progression while GNE myopathy (GNEM), a neuromuscular disorder, causes muscle degeneration and loss of muscle motor movement with age. Individuals with mutations in presenilin or amyloid precursor protein (APP) gene develop AD while mutations in GNE (UDP N-acetylglucosamine 2 epimerase/N-acetyl Mannosamine kinase), key sialic acid biosynthesis enzyme, cause GNEM. Although GNEM is characterized with degeneration of muscle cells, it is shown to have similar disease hallmarks like aggregation of Aβ and accumulation of phosphorylated tau and other misfolded proteins in muscle cell similar to AD. Similar impairment in cellular functions have been reported in both disorders such as disruption of cytoskeletal network, changes in glycosylation pattern, mitochondrial dysfunction, oxidative stress, upregulation of chaperones, unfolded protein response in ER, autophagic vacuoles, cell death, and apoptosis. Interestingly, AD and GNEM are the two diseases with similar phenotypic condition affecting neuron and muscle, respectively, resulting in entirely different pathology. This review represents a comparative outlook of AD and GNEM that could lead to target common mechanism to find a plausible therapeutic for both the diseases.
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Affiliation(s)
| | - Rashmi Yadav
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Pratibha Chanana
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Ranjana Arya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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13
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Carrillo N, Malicdan MC, Huizing M. GNE Myopathy: Etiology, Diagnosis, and Therapeutic Challenges. Neurotherapeutics 2018; 15:900-914. [PMID: 30338442 PMCID: PMC6277305 DOI: 10.1007/s13311-018-0671-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
GNE myopathy, previously known as hereditary inclusion body myopathy (HIBM), or Nonaka myopathy, is a rare autosomal recessive muscle disease characterized by progressive skeletal muscle atrophy. It has an estimated prevalence of 1 to 9:1,000,000. GNE myopathy is caused by mutations in the GNE gene which encodes the rate-limiting enzyme of sialic acid biosynthesis. The pathophysiology of the disease is not entirely understood, but hyposialylation of muscle glycans is thought to play an essential role. The typical presentation is bilateral foot drop caused by weakness of the anterior tibialis muscles with onset in early adulthood. The disease slowly progresses over the next decades to involve skeletal muscles throughout the body, with relative sparing of the quadriceps until late stages of the disease. The diagnosis of GNE myopathy should be considered in young adults presenting with bilateral foot drop. Histopathologic findings on muscle biopsies include fiber size variation, atrophic fibers, lack of inflammation, and the characteristic "rimmed" vacuoles on modified Gomori trichome staining. The diagnosis is confirmed by the presence of pathogenic (mostly missense) mutations in both alleles of the GNE gene. Although there is no approved therapy for this disease, preclinical and clinical studies of several potential therapies are underway, including substrate replacement and gene therapy-based strategies. However, developing therapies for GNE myopathy is complicated by several factors, including the rare incidence of disease, limited preclinical models, lack of reliable biomarkers, and slow disease progression.
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Affiliation(s)
- Nuria Carrillo
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD, 20892, USA.
| | - May C Malicdan
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD, 20892, USA
| | - Marjan Huizing
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD, 20892, USA
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Detienne G, De Haes W, Mergan L, Edwards SL, Temmerman L, Van Bael S. Beyond ROS clearance: Peroxiredoxins in stress signaling and aging. Ageing Res Rev 2018; 44:33-48. [PMID: 29580920 DOI: 10.1016/j.arr.2018.03.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 03/21/2018] [Indexed: 12/12/2022]
Abstract
Antioxidants were long predicted to have lifespan-promoting effects, but in general this prediction has not been well supported. While some antioxidants do seem to have a clear effect on longevity, this may not be primarily as a result of their role in the removal of reactive oxygen species, but rather mediated by other mechanisms such as the modulation of intracellular signaling. In this review we discuss peroxiredoxins, a class of proteinaceous antioxidants with redox signaling and chaperone functions, and their involvement in regulating longevity and stress resistance. Peroxiredoxins have a clear role in the regulation of lifespan and survival of many model organisms, including the mouse, Caenorhabditis elegans and Drosophila melanogaster. Recent research on peroxiredoxins - in these models and beyond - has revealed surprising new insights regarding the interplay between peroxiredoxins and longevity signaling, which will be discussed here in detail. As redox signaling is emerging as a potentially important player in the regulation of longevity and aging, increased knowledge of these fascinating antioxidants and their mode(s) of action is paramount.
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Affiliation(s)
- Giel Detienne
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
| | - Wouter De Haes
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
| | - Lucas Mergan
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
| | - Samantha L Edwards
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
| | - Liesbet Temmerman
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
| | - Sven Van Bael
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
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