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Wang D, Li B, Wang S, Hao Y, Wang H, Sun W, Cao J, Zhou X, Zheng B. Engineered inhaled nanocatalytic therapy for ischemic cerebrovascular disease by inducing autophagy of abnormal mitochondria. NPJ Regen Med 2023; 8:44. [PMID: 37567914 PMCID: PMC10421937 DOI: 10.1038/s41536-023-00315-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 07/18/2023] [Indexed: 08/13/2023] Open
Abstract
Mitochondrial dysfunction and subsequent accumulation of reactive oxygen species (ROS) are key contributors to the pathology of ischemic cerebrovascular disease. Therefore, elimination of ROS and damaged mitochondria is crucial for the effective treatment of this disease. For this purpose, we designed an inhalation nanotherapeutic agent, P/D@Mn/Co3O4, to treat ischemic cerebrovascular disease. Mn/Co3O4 effectively removed excess ROS from cells, reduced acute cellular oxidative stress, and protected neural cells from apoptosis. Furthermore, it depleted the H+ surrounding mitochondria and depolarized the mitochondrial membrane potential, inducing mitophagy and eliminating abnormal mitochondria, thereby avoiding the continuous overproduction of ROS by eliminating the source of ROS regeneration. On intranasal administration, Mn/Co3O4 encapsulated by platelet membranes and 2,3-(dioxy propyl)-trimethylammonium chloride can bypass the blood-brain barrier, enter the brain through the trigeminal and olfactory pathways, and target inflammatory regions to remove ROS and damaged mitochondria from the lesion area. In rat models of stroke and vascular dementia, P/D@Mn/Co3O4 effectively inhibited the symptoms of acute and chronic cerebral ischemia by scavenging ROS and damaged mitochondria in the affected area. Our findings indicate that the nanotherapeutic agent developed in this study can be used for the effective treatment of ischemic cerebrovascular disease.
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Affiliation(s)
- Deping Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Xincheng Hospital of Tianjin University, Tianjin University, Tianjin, 300072, China
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, 030001, China
| | - Bowen Li
- Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Xincheng Hospital of Tianjin University, Tianjin University, Tianjin, 300072, China
| | - Shuchao Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Xincheng Hospital of Tianjin University, Tianjin University, Tianjin, 300072, China
| | - Yingjian Hao
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, 030001, China
| | - Hua Wang
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Wei Sun
- Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Xincheng Hospital of Tianjin University, Tianjin University, Tianjin, 300072, China
| | - Jimin Cao
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, 030001, China.
| | - Xin Zhou
- Key Laboratory of Cellular Physiology, Ministry of Education, and the Department of Physiology, Shanxi Medical University, Taiyuan, 030001, China.
| | - Bin Zheng
- Academy of Medical Engineering and Translational Medicine, Tianjin Key Laboratory of Brain Science and Neural Engineering, Xincheng Hospital of Tianjin University, Tianjin University, Tianjin, 300072, China.
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2
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Riboldi GM, Faravelli I, Rinchetti P, Lotti F. SMN post-translational modifications in spinal muscular atrophy. Front Cell Neurosci 2023; 17:1092488. [PMID: 36874214 PMCID: PMC9981653 DOI: 10.3389/fncel.2023.1092488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/26/2023] [Indexed: 02/19/2023] Open
Abstract
Since its first identification as the gene responsible for spinal muscular atrophy (SMA), the range of survival motor neuron (SMN) protein functions has increasingly expanded. This multimeric complex plays a crucial role in a variety of RNA processing pathways. While its most characterized function is in the biogenesis of ribonucleoproteins, several studies have highlighted the SMN complex as an important contributor to mRNA trafficking and translation, axonal transport, endocytosis, and mitochondria metabolism. All these multiple functions need to be selectively and finely modulated to maintain cellular homeostasis. SMN has distinct functional domains that play a crucial role in complex stability, function, and subcellular distribution. Many different processes were reported as modulators of the SMN complex activities, although their contribution to SMN biology still needs to be elucidated. Recent evidence has identified post-translational modifications (PTMs) as a way to regulate the pleiotropic functions of the SMN complex. These modifications include phosphorylation, methylation, ubiquitination, acetylation, sumoylation, and many other types. PTMs can broaden the range of protein functions by binding chemical moieties to specific amino acids, thus modulating several cellular processes. Here, we provide an overview of the main PTMs involved in the regulation of the SMN complex with a major focus on the functions that have been linked to SMA pathogenesis.
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Affiliation(s)
| | | | | | - Francesco Lotti
- Center for Motor Neuron Biology and Diseases, Departments of Pathology & Cell Biology, and Neurology, Columbia University Irving Medical Center, New York, NY, United States
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3
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Zilio E, Piano V, Wirth B. Mitochondrial Dysfunction in Spinal Muscular Atrophy. Int J Mol Sci 2022; 23:ijms231810878. [PMID: 36142791 PMCID: PMC9503857 DOI: 10.3390/ijms231810878] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder caused by recessive mutations in the SMN1 gene, globally affecting ~8-14 newborns per 100,000. The severity of the disease depends on the residual levels of functional survival of motor neuron protein, SMN. SMN is a ubiquitously expressed RNA binding protein involved in a plethora of cellular processes. In this review, we discuss the effects of SMN loss on mitochondrial functions in the neuronal and muscular systems that are the most affected in patients with spinal muscular atrophy. Our aim is to highlight how mitochondrial defects may contribute to disease progression and how restoring mitochondrial functionality may be a promising approach to develop new therapies. We also collected from previous studies a list of transcripts encoding mitochondrial proteins affected in various SMA models. Moreover, we speculate that in adulthood, when motor neurons require only very low SMN levels, the natural deterioration of mitochondria associated with aging may be a crucial triggering factor for adult spinal muscular atrophy, and this requires particular attention for therapeutic strategies.
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Affiliation(s)
- Eleonora Zilio
- Institute of Human Genetics, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany
| | - Valentina Piano
- Institute of Human Genetics, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany
- Correspondence: (V.P.); (B.W.)
| | - Brunhilde Wirth
- Institute of Human Genetics, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany
- Correspondence: (V.P.); (B.W.)
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4
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Xu H, Liu X, Li W, Xi Y, Su P, Meng B, Shao X, Tang B, Yang Q, Mao Z. p38 MAPK-mediated loss of nuclear RNase III enzyme Drosha underlies amyloid beta-induced neuronal stress in Alzheimer's disease. Aging Cell 2021; 20:e13434. [PMID: 34528746 PMCID: PMC8521488 DOI: 10.1111/acel.13434] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/26/2021] [Accepted: 07/03/2021] [Indexed: 12/30/2022] Open
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs ubiquitously expressed in the brain and regulate gene expression at the post‐transcriptional level. The nuclear RNase III enzyme Drosha initiates the maturation process of miRNAs in the nucleus. Strong evidence suggests that dysregulation of miRNAs is involved in many neurological disorders including Alzheimer's disease (AD). Dysfunction of miRNA biogenesis components may be involved in the processes of those diseases. However, the role of Drosha in AD remains unknown. By using immunohistochemistry, biochemistry, and subcellular fractionation methods, we show here that the level of Drosha protein was significantly lower in the postmortem brain of human AD patients as well as in the transgenic rat model of AD. Interestingly, Drosha level was specifically reduced in neurons of the cortex and hippocampus but not in the cerebellum in the AD brain samples. In primary cortical neurons, amyloid‐beta (Aβ) oligomers caused a p38 MAPK‐dependent phosphorylation of Drosha, leading to its redistribution from the nucleus to the cytoplasm and a decrease in its level. This loss of Drosha function preceded Aβ‐induced neuronal death. Importantly, inhibition of p38 MAPK activity or overexpression of Drosha protected neurons from Aβ oligomers‐induced apoptosis. Taken together, these results establish a role for p38 MAPK‐Drosha pathway in modulating neuronal viability under Aβ oligomers stress condition and implicate loss of Drosha as a key molecular change in the pathogenesis of AD.
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Affiliation(s)
- Haidong Xu
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
| | - Xiaolei Liu
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
| | - Wenming Li
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
| | - Ye Xi
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
| | - Peng Su
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
| | - Bo Meng
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
| | - Xiaoyun Shao
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
| | - Beisha Tang
- Department of Neurology Xiangya Hospital Central South University Changsha China
| | - Qian Yang
- Department of Neurosurgery Tangdu Hospital The Fourth Military Medical University Xi'an China
| | - Zixu Mao
- Department of Pharmacology and Chemical Biology Emory University School of Medicine Atlanta Georgia USA
- Department of Neurology Emory University School of Medicine Atlanta Georgia USA
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5
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Abiusi E, Infante P, Cagnoli C, Lospinoso Severini L, Pane M, Coratti G, Pera MC, D'Amico A, Diano F, Novelli A, Spartano S, Fiori S, Baranello G, Moroni I, Mora M, Pasanisi MB, Pocino K, Le Pera L, D'Amico D, Travaglini L, Ria F, Bruno C, Locatelli D, Bertini ES, Morandi LO, Mercuri E, Di Marcotullio L, Tiziano FD. SMA-miRs (miR-181a-5p, -324-5p, and -451a) are overexpressed in spinal muscular atrophy skeletal muscle and serum samples. eLife 2021; 10:68054. [PMID: 34542403 PMCID: PMC8486378 DOI: 10.7554/elife.68054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 09/13/2021] [Indexed: 12/24/2022] Open
Abstract
Background: Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by the degeneration of the second motor neuron. The phenotype ranges from very severe to very mild forms. All patients have the homozygous loss of the SMN1 gene and a variable number of SMN2 (generally 2–4 copies), inversely related to the severity. The amazing results of the available treatments have made compelling the need of prognostic biomarkers to predict the progression trajectories of patients. Besides the SMN2 products, few other biomarkers have been evaluated so far, including some miRs. Methods: We performed whole miRNome analysis of muscle samples of patients and controls (14 biopsies and 9 cultures). The levels of muscle differentially expressed miRs were evaluated in serum samples (51 patients and 37 controls) and integrated with SMN2 copies, SMN2 full-length transcript levels in blood and age (SMA-score). Results: Over 100 miRs were differentially expressed in SMA muscle; 3 of them (hsa-miR-181a-5p, -324-5p, -451a; SMA-miRs) were significantly upregulated in the serum of patients. The severity predicted by the SMA-score was related to that of the clinical classification at a correlation coefficient of 0.87 (p<10-5). Conclusions: miRNome analyses suggest the primary involvement of skeletal muscle in SMA pathogenesis. The SMA-miRs are likely actively released in the blood flow; their function and target cells require to be elucidated. The accuracy of the SMA-score needs to be verified in replicative studies: if confirmed, its use could be crucial for the routine prognostic assessment, also in presymptomatic patients. Funding: Telethon Italia (grant #GGP12116).
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Affiliation(s)
- Emanuela Abiusi
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Paola Infante
- Center For Life Nano Science@Sapienza, Istituto Italiano di Tecnologia; Department of Molecular Medicine, Università degli Studi di Roma "La Sapienza", Roma, Italy, Roma, Italy
| | - Cinzia Cagnoli
- Clinical and Experimental Epileptology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy, Roma, Italy
| | | | - Marika Pane
- Pediatric Neurology, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy.,Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Giorgia Coratti
- Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Maria Carmela Pera
- Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Adele D'Amico
- Unit of Neuromuscular and Neurodegenerative Disorders, Dept. Neurosciences, Bambino Gesu' Children's Hospital IRCCS, Roma, Italy
| | - Federica Diano
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Agnese Novelli
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Serena Spartano
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Stefania Fiori
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Giovanni Baranello
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Isabella Moroni
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marina Mora
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Maria Barbara Pasanisi
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Krizia Pocino
- Department of Medical and Surgical Sciences, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Roma, Italy
| | - Loredana Le Pera
- Bioenergetics and Molecular Biotechnologies (IBIOM), CNR-Institute of Biomembranes, Bari, Italy.,CNR-Institute of Molecular Biology and Pathology (IBPM), Rome, Italy
| | - Davide D'Amico
- Amazentis SA, EPFL Innovation Park, Losanne, Switzerland
| | - Lorena Travaglini
- Unit of Neuromuscular and Neurodegenerative Disorders, Dept. Neurosciences, Bambino Gesu' Children's Hospital IRCCS, Roma, Italy
| | - Francesco Ria
- Department of Translational Medicine and Surgery, Section of General Pathology, Università Cattolica del Sacro Cuore, Roma, Italy.,Fondazione Policlinico Universitario A. Gemelli - IRCCS, Rome, Italy
| | - Claudio Bruno
- Center of Translational and Experimental Myology, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Denise Locatelli
- Clinical and Experimental Epileptology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy, Roma, Italy
| | - Enrico Silvio Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Dept. Neurosciences, Bambino Gesu' Children's Hospital IRCCS, Roma, Italy
| | - Lucia Ovidia Morandi
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Eugenio Mercuri
- Pediatric Neurology, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy.,Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Lucia Di Marcotullio
- Department of Molecular Medicine, Università degli Studi di Roma "La Sapienza", Roma, Italy.,Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Francesco Danilo Tiziano
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy.,Unit of Medical Genetics, Department of Laboratory science and Infectious Diseases, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Rome, Italy
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6
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Lett KE, Logan MK, McLaurin DM, Hebert MD. Coilin enhances phosphorylation and stability of DGCR8 and promotes miRNA biogenesis. Mol Biol Cell 2021; 32:br4. [PMID: 34319763 PMCID: PMC8684749 DOI: 10.1091/mbc.e21-05-0225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
MicroRNAs (miRNAs) are ∼22 nt small noncoding RNAs that control gene expression at the posttranscriptional level through translational inhibition and destabilization of their target mRNAs. The biogenesis of miRNAs involves a series of processing steps beginning with cropping of the primary miRNA transcript by the Microprocessor complex, which is comprised of Drosha and DGCR8. Here we report a novel regulatory interaction between the Microprocessor components and coilin, the Cajal Body (CB) marker protein. Coilin knockdown causes alterations in the level of primary and mature miRNAs, let-7a and miR-34a, and their miRNA targets, HMGA2 and Notch1, respectively. We also found that coilin knockdown affects the levels of DGCR8 and Drosha in cells with (HeLa) and without (WI-38) CBs. To further explore the role of coilin in miRNA biogenesis, we conducted a series of co-immunoprecipitation experiments using coilin and DGCR8 constructs, which revealed that coilin and DGCR8 can form a complex. Additionally, our results indicate that phosphorylation of DGCR8, which has been shown to increase protein stability, is impacted by coilin knockdown. Collectively, our results implicate coilin as a member of the regulatory network governing miRNA biogenesis.
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Affiliation(s)
- Katheryn E Lett
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
| | - Madelyn K Logan
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
| | - Douglas M McLaurin
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
| | - Michael D Hebert
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
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7
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Chen TH. Circulating microRNAs as potential biomarkers and therapeutic targets in spinal muscular atrophy. Ther Adv Neurol Disord 2021; 13:1756286420979954. [PMID: 33488772 PMCID: PMC7768327 DOI: 10.1177/1756286420979954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/20/2020] [Indexed: 12/12/2022] Open
Abstract
Spinal muscular atrophy (SMA), a leading genetic cause of infant death, is a neurodegenerative disease characterized by the selective loss of particular groups of motor neurons (MNs) in the anterior horn of the spinal cord with progressive muscle wasting. SMA is caused by a deficiency of the survival motor neuron (SMN) protein due to a homozygous deletion or mutation of the SMN1 gene. However, the molecular mechanisms whereby the SMN complex regulates MN functions are not fully elucidated. Emerging studies on SMA pathogenesis have turned the attention of researchers to RNA metabolism, given that increasingly identified SMN-associated modifiers are involved in both coding and non-coding RNA (ncRNA) processing. Among various ncRNAs, microRNAs (miRNAs) are the most studied in terms of regulation of posttranscriptional gene expression. Recently, the discovery that miRNAs are critical to MN function and survival led to the study of dysregulated miRNAs in SMA pathogenesis. Circulating miRNAs have drawn attention as a readily available biomarker due to their property of being clinically detectable in numerous human biofluids through non-invasive approaches. As there are recent promising findings from novel miRNA-based medicines, this article presents an extensive review of the most up-to-date studies connecting specific miRNAs to SMA pathogenesis and the potential applications of miRNAs as biomarkers and therapeutic targets for SMA.
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Affiliation(s)
- Tai-Heng Chen
- Department of Pediatrics, Division of Pediatric Emergency, Kaohsiung Medical University Hospital, School of Post-Baccalaureate Medicine, College of Medicine, Kaohsiung Medical University, No. 100, Tzyou 1st Road, Kaohsiung 80708, Taiwan
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8
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Wirth B. Spinal Muscular Atrophy: In the Challenge Lies a Solution. Trends Neurosci 2021; 44:306-322. [PMID: 33423791 DOI: 10.1016/j.tins.2020.11.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/08/2020] [Accepted: 11/30/2020] [Indexed: 12/16/2022]
Abstract
The path from gene discovery to therapy in spinal muscular atrophy (SMA) has been a highly challenging endeavor, but also led to one of the most successful stories in neurogenetics. In SMA, a neuromuscular disorder with an often fatal outcome until recently, with those affected never able to sit, stand, or walk, children now achieve these motoric abilities and almost age-based development when treated presymptomatically. This review summarizes the challenges along this 30-year journey. It is also meant to inspire early-career scientists not to give up when things become difficult but to try to uncover the biological underpinnings and transform the challenge into the next big discovery. Without doubt, the improvements seen with the three therapeutic strategies in SMA are impressive; many open questions remain and are discussed in this review.
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Affiliation(s)
- Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine, Center for Rare Disorders, University of Cologne, Kerpener Str. 34, 50931 Cologne, Germany.
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9
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Thelen MP, Wirth B, Kye MJ. Mitochondrial defects in the respiratory complex I contribute to impaired translational initiation via ROS and energy homeostasis in SMA motor neurons. Acta Neuropathol Commun 2020; 8:223. [PMID: 33353564 PMCID: PMC7754598 DOI: 10.1186/s40478-020-01101-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 12/22/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by loss of lower motor neurons, which leads to proximal muscle weakness and atrophy. SMA is caused by reduced survival motor neuron (SMN) protein levels due to biallelic deletions or mutations in the SMN1 gene. When SMN levels fall under a certain threshold, a plethora of cellular pathways are disturbed, including RNA processing, protein synthesis, metabolic defects, and mitochondrial function. Dysfunctional mitochondria can harm cells by decreased ATP production and increased oxidative stress due to elevated cellular levels of reactive oxygen species (ROS). Since neurons mainly produce energy via mitochondrial oxidative phosphorylation, restoring metabolic/oxidative homeostasis might rescue SMA pathology. Here, we report, based on proteome analysis, that SMA motor neurons show disturbed energy homeostasis due to dysfunction of mitochondrial complex I. This results in a lower basal ATP concentration and higher ROS production that causes an increase of protein carbonylation and impaired protein synthesis in SMA motor neurons. Counteracting these cellular impairments with pyruvate reduces elevated ROS levels, increases ATP and SMN protein levels in SMA motor neurons. Furthermore, we found that pyruvate-mediated SMN protein synthesis is mTOR-dependent. Most importantly, we showed that ROS regulates protein synthesis at the translational initiation step, which is impaired in SMA. As many neuropathies share pathological phenotypes such as dysfunctional mitochondria, excessive ROS, and impaired protein synthesis, our findings suggest new molecular interactions among these pathways. Additionally, counteracting these impairments by reducing ROS and increasing ATP might be beneficial for motor neuron survival in SMA patients.
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10
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Simon CM, Van Alstyne M, Lotti F, Bianchetti E, Tisdale S, Watterson DM, Mentis GZ, Pellizzoni L. Stasimon Contributes to the Loss of Sensory Synapses and Motor Neuron Death in a Mouse Model of Spinal Muscular Atrophy. Cell Rep 2020; 29:3885-3901.e5. [PMID: 31851921 PMCID: PMC6956708 DOI: 10.1016/j.celrep.2019.11.058] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/08/2019] [Accepted: 11/14/2019] [Indexed: 12/31/2022] Open
Abstract
Reduced expression of the survival motor neuron (SMN) protein causes the neurodegenerative disease spinal muscular atrophy (SMA). Here, we show that adeno-associated virus serotype 9 (AAV9)-mediated delivery of Stasimon—a gene encoding an endoplasmic reticulum (ER)-resident transmembrane protein regulated by SMN—improves motor function in a mouse model of SMA through multiple mechanisms. In proprioceptive neurons, Stasimon overexpression prevents the loss of afferent synapses on motor neurons and enhances sensory-motor neurotransmission. In motor neurons, Stasimon suppresses neurodegeneration by reducing phosphorylation of the tumor suppressor p53. Moreover, Stasimon deficiency converges on SMA-related mechanisms of p53 upregulation to induce phosphorylation of p53 through activation of p38 mitogen-activated protein kinase (MAPK), and pharmacological inhibition of this kinase prevents motor neuron death in SMA mice. These findings identify Stasimon dysfunction induced by SMN deficiency as an upstream driver of distinct cellular cascades that lead to synaptic loss and motor neuron degeneration, revealing a dual contribution of Stasimon to motor circuit pathology in SMA. SMN deficiency causes motor circuit dysfunction in SMA. Simon et al. show that Stasimon—an ER-resident protein regulated by SMN—contributes to sensory synaptic loss and motor neuron death in SMA mice through distinct mechanisms. In motor neurons, Stasimon dysfunction induces p38 MAPK-mediated phosphorylation of p53 whose inhibition prevents neurodegeneration.
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Affiliation(s)
- Christian M Simon
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Meaghan Van Alstyne
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Francesco Lotti
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Elena Bianchetti
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Sarah Tisdale
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - D Martin Watterson
- Department of Pharmacology, Northwestern University, Chicago, IL 60611, USA
| | - George Z Mentis
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA; Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Livio Pellizzoni
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA.
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Logan MK, McLaurin DM, Hebert MD. Synergistic interactions between Cajal bodies and the miRNA processing machinery. Mol Biol Cell 2020; 31:1561-1569. [PMID: 32432989 PMCID: PMC7521794 DOI: 10.1091/mbc.e20-02-0144] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cajal bodies (CBs) are subnuclear domains involved in the formation of ribonucleoproteins (RNPs) including small nuclear RNPs (snRNPs). CBs associate with specific gene loci, which impacts expression and provides a platform for the biogenesis of the nascent transcripts emanating from these genes. Here we report that CBs can associate with the C19MC microRNA (miRNA) gene cluster, which suggests a role for CBs in the biogenesis of animal miRNAs. The machinery involved in the formation of miRNAs includes the Drosha/DGCR8 complex, which processes primary-miRNA to precursor miRNA. Further processing of precursor miRNA by Dicer and other components generates mature miRNA. To test if CBs influence the expression and formation of miRNAs, we examined two representative miRNAs (miR-520 h and let-7a) in conditions that disrupt CBs. CB disruption correlates with alterations in the level of primary and mature miRNA and the let-7a mRNA target, HMGA2. We have also found that the processing of some small CB-specific RNAs (scaRNAs) is directly mediated by the Drosha/DGCR8 complex. ScaRNAs form scaRNPs, which play an important role in snRNP formation. Collectively, our results demonstrate that CBs and the miRNA processing machinery functionally interact and together contribute to the biogenesis of miRNAs and snRNPs.
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Affiliation(s)
- Madelyn K Logan
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, MS 39216
| | - Douglas M McLaurin
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, MS 39216
| | - Michael D Hebert
- Department of Cell and Molecular Biology, The University of Mississippi Medical Center, Jackson, MS 39216
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Autophagy in motor neuron diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 172:157-202. [PMID: 32620242 DOI: 10.1016/bs.pmbts.2020.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Motor neuron diseases (MNDs) are a wide group of neurodegenerative disorders characterized by the degeneration of a specific neuronal type located in the central nervous system, the motor neuron (MN). There are two main types of MNs, spinal and cortical MNs and depending on the type of MND, one or both types are affected. Cortical MNs innervate spinal MNs and these control a variety of cellular targets, being skeletal muscle their main one which is also affected in MNDs. A correct functionality of autophagy is necessary for the survival of all cellular types and it is particularly crucial for neurons, given their postmitotic and highly specialized nature. Numerous studies have identified alterations of autophagy activity in multiple MNDs. The scientific community has been particularly prolific in reporting the role that autophagy plays in the most common adult MND, amyotrophic lateral sclerosis, although many studies have started to identify physiological and pathological functions of this catabolic system in other MNDs, such as spinal muscular atrophy and spinal and bulbar muscular atrophy. The degradation of selective cargo by autophagy and how this process is altered upon the presence of MND-causing mutations is currently also a matter of intense investigation, particularly regarding the selective autophagic clearance of mitochondria. Thorough reviews on this field have been recently published. This chapter will cover the current knowledge on the functionality of autophagy and lysosomal homeostasis in the main MNDs and other autophagy-related topics in the MND field that have risen special interest in the research community.
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Chen TH, Chen JA. Multifaceted roles of microRNAs: From motor neuron generation in embryos to degeneration in spinal muscular atrophy. eLife 2019; 8:50848. [PMID: 31738166 PMCID: PMC6861003 DOI: 10.7554/elife.50848] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/05/2019] [Indexed: 12/12/2022] Open
Abstract
Two crucial questions in neuroscience are how neurons establish individual identity in the developing nervous system and why only specific neuron subtypes are vulnerable to neurodegenerative diseases. In the central nervous system, spinal motor neurons serve as one of the best-characterized cell types for addressing these two questions. In this review, we dissect these questions by evaluating the emerging role of regulatory microRNAs in motor neuron generation in developing embryos and their potential contributions to neurodegenerative diseases such as spinal muscular atrophy (SMA). Given recent promising results from novel microRNA-based medicines, we discuss the potential applications of microRNAs for clinical assessments of SMA disease progression and treatment.
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Affiliation(s)
- Tai-Heng Chen
- PhD Program in Translational Medicine, Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Academia Sinica, Kaohsiung, Taiwan.,Department of Pediatrics, Division of Pediatric Emergency, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jun-An Chen
- PhD Program in Translational Medicine, Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Academia Sinica, Kaohsiung, Taiwan.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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Rehorst WA, Thelen MP, Nolte H, Türk C, Cirak S, Peterson JM, Wong GW, Wirth B, Krüger M, Winter D, Kye MJ. Muscle regulates mTOR dependent axonal local translation in motor neurons via CTRP3 secretion: implications for a neuromuscular disorder, spinal muscular atrophy. Acta Neuropathol Commun 2019; 7:154. [PMID: 31615574 PMCID: PMC6794869 DOI: 10.1186/s40478-019-0806-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 12/19/2022] Open
Abstract
Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder, which causes dysfunction/loss of lower motor neurons and muscle weakness as well as atrophy. While SMA is primarily considered as a motor neuron disease, recent data suggests that survival motor neuron (SMN) deficiency in muscle causes intrinsic defects. We systematically profiled secreted proteins from control and SMN deficient muscle cells with two combined metabolic labeling methods and mass spectrometry. From the screening, we found lower levels of C1q/TNF-related protein 3 (CTRP3) in the SMA muscle secretome and confirmed that CTRP3 levels are indeed reduced in muscle tissues and serum of an SMA mouse model. We identified that CTRP3 regulates neuronal protein synthesis including SMN via mTOR pathway. Furthermore, CTRP3 enhances axonal outgrowth and protein synthesis rate, which are well-known impaired processes in SMA motor neurons. Our data revealed a new molecular mechanism by which muscles regulate the physiology of motor neurons via secreted molecules. Dysregulation of this mechanism contributes to the pathophysiology of SMA.
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Analysis of the Association Between MicroRNA Biogenesis Gene Polymorphisms and Venous Thromboembolism in Koreans. Int J Mol Sci 2019; 20:ijms20153771. [PMID: 31374978 PMCID: PMC6695971 DOI: 10.3390/ijms20153771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/26/2019] [Accepted: 07/31/2019] [Indexed: 12/15/2022] Open
Abstract
Venous thromboembolism (VTE) involves the formation of a blood clot, typically in the deep veins of the leg or arm (deep vein thrombosis), which then travels via the circulatory system and ultimately lodges in the lungs, resulting in pulmonary embolism. A number of microRNAs (miRNAs) are well-known regulators of thrombosis and thrombolysis, and mutations in miRNA biogenesis genes, such as DICER1, DROSHA have been implicated in miRNA synthesis and function. We investigated the genetic association between polymorphisms in four miRNA biogenesis genes, DICER1 rs3742330A > G, DROSHA rs10719T > C, RAN rs14035C > T and XPO5 rs11077A > C, and VTE in 503 Koreans: 300 controls and 203 patients. Genotyping was assessed with polymerase chain reaction-restriction fragment length polymorphism assays. We detected associations between polymorphisms in RAN and XPO5 and VTE prevalence (RAN rs14035CC + CT versus TT: p = 0.018; XPO5 rs11077AA + AC versus CC: p < 0.001). Analysis of allele combinations of all four polymorphisms (DICER1, DROSHA, RAN, XPO5) revealed that A-T-T-A was associated with decreased VTE prevalence (p = 0.0002), and A-T-C-C was associated with increased VTE prevalence (p = 0.027). Moreover, in subjects with provoked VTE, the DROSHA rs10719T > C, polymorphism was associated with increased disease prevalence (TT versus TC + CC: p < 0.039). Our study demonstrates that RAN and XPO5 polymorphisms are associated with risk for VTE in Korean subjects.
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