1
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Xu B, Anderson BM, Mountford SJ, Thompson PE, Mintern JD, Edgington-Mitchell LE. Cathepsin X deficiency alters the processing and localisation of cathepsin L and impairs cleavage of a nuclear cathepsin L substrate. Biol Chem 2024; 405:351-365. [PMID: 38410910 DOI: 10.1515/hsz-2023-0355] [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: 11/29/2023] [Accepted: 02/12/2024] [Indexed: 02/28/2024]
Abstract
Proteases function within sophisticated networks. Altering the activity of one protease can have sweeping effects on other proteases, leading to changes in their activity, structure, specificity, localisation, stability, and expression. Using a suite of chemical tools, we investigated the impact of cathepsin X, a lysosomal cysteine protease, on the activity and expression of other cysteine proteases and their inhibitors in dendritic cells. Among all proteases examined, cathepsin X gene deletion specifically altered cathepsin L levels; pro-cathepsin L and its single chain accumulated while the two-chain form was unchanged. This effect was recapitulated by chemical inhibition of cathepsin X, suggesting a dependence on its catalytic activity. We demonstrated that accumulation of pro- and single chain cathepsin L was not due to a lack of direct cleavage by cathepsin X or altered glycosylation, secretion, or mRNA expression but may result from changes in lysosomal oxidative stress or pH. In the absence of active cathepsin X, nuclear cathepsin L and cleavage of the known nuclear cathepsin L substrate, Lamin B1, were diminished. Thus, cathepsin X activity selectively regulates cathepsin L, which has the potential to impact the degree of cathepsin L proteolysis, the nature of substrates that it cleaves, and the location of cleavage.
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Affiliation(s)
- Bangyan Xu
- Department of Biochemistry & Pharmacology, 2281 Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Parkville, VIC 3052, Australia
| | - Bethany M Anderson
- Department of Biochemistry & Pharmacology, 2281 Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Parkville, VIC 3052, Australia
| | - Simon J Mountford
- Medicinal Chemistry, 2541 Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, VIC 3052, Australia
| | - Philip E Thompson
- Medicinal Chemistry, 2541 Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, VIC 3052, Australia
| | - Justine D Mintern
- Department of Biochemistry & Pharmacology, 2281 Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Parkville, VIC 3052, Australia
| | - Laura E Edgington-Mitchell
- Department of Biochemistry & Pharmacology, 2281 Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Parkville, VIC 3052, Australia
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2
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Gumusgoz E, Kasiri S, Verma M, Wu J, Villarreal Acha D, Marriam U, Fyffe-Maricich S, Lin A, Chen X, Gray SJ, Minassian BA. CSTB gene replacement improves neuroinflammation, neurodegeneration and ataxia in murine type 1 progressive myoclonus epilepsy. Gene Ther 2024; 31:234-241. [PMID: 38135787 DOI: 10.1038/s41434-023-00433-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/30/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023]
Abstract
EPM1 is the most common form of Progressive Myoclonus Epilepsy characterized by late-childhood onset, ever-worsening and disabling myoclonus, seizures, ataxia, psychiatric disease, and shortened lifespan. EPM1 is caused by expansions of a dodecamer repeat sequence in the promoter of CSTB (cystatin B), which dramatically reduces, but does not eliminate, gene expression. The relatively late onset and consistent presence of a minimal amount of protein product makes EPM1 a favorable target for gene replacement therapy. If treated early, these children's normally developed brains could be rescued from the neurodegeneration that otherwise follows, and their cross-reactive immunological material (CRIM) positive status greatly reduces transgene related toxicity. We performed a proof-of-concept CSTB gene replacement study in Cstb knockout mice by introducing full-length human CSTB driven by the CBh promoter packaged in AAV9 and administered at postnatal days 21 and 60. Mice were sacrificed at 2 or 9 months of age, respectively. We observed significant improvements in expression levels of neuroinflammatory pathway genes and cerebellar granule cell layer apoptosis, as well as amelioration of motor impairment. The data suggest that gene replacement is a promising therapeutic modality for EPM1 and could spare affected children and families the ravages of this otherwise severe neurodegenerative disease.
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Affiliation(s)
- Emrah Gumusgoz
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Sahba Kasiri
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Mayank Verma
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Daniel Villarreal Acha
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ummay Marriam
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | | | - Xin Chen
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Steven J Gray
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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3
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Singh S, Hämäläinen RH. The Roles of Cystatin B in the Brain and Pathophysiological Mechanisms of Progressive Myoclonic Epilepsy Type 1. Cells 2024; 13:170. [PMID: 38247861 PMCID: PMC10814315 DOI: 10.3390/cells13020170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/03/2024] [Accepted: 01/15/2024] [Indexed: 01/23/2024] Open
Abstract
Progressive myoclonic epilepsy type 1 (EPM1) is an autosomal recessive disorder, also known as Unverricht-Lundborg disease (ULD). EPM1 patients suffer from photo-sensitive seizures, stimulus-sensitive myoclonus, nocturnal myoclonic seizures, ataxia and dysarthria. In addition, cerebral ataxia and impaired GABAergic inhibition are typically present. EPM1 is caused by mutations in the Cystatin B gene (CSTB). The CSTB protein functions as an intracellular thiol protease inhibitor and inhibits Cathepsin function. It also plays a crucial role in brain development and regulates various functions in neurons beyond maintaining cellular proteostasis. These include controlling cell proliferation and differentiation, synaptic functions and protection against oxidative stress, likely through regulation of mitochondrial function. Depending on the differentiation stage and status of neurons, the protein localizes either to the cytoplasm, nucleus, lysosomes or mitochondria. Further, CSTB can also be secreted to the extracellular matrix for interneuron rearrangement and migration. In this review, we will review the various functions of CSTB in the brain and discuss the putative pathophysiological mechanism underlying EPM1.
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Affiliation(s)
| | - Riikka H. Hämäläinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Neulaniementie 2, 70211 Kuopio, Finland;
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4
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Pollari E, Tegelberg S, Björklund H, Kälviäinen R, Lehesjoki AE, Haapalinna A. In depth behavioral phenotyping unravels complex motor disturbances in Cstb-/- mouse, a model for progressive myoclonus epilepsy type 1. Front Behav Neurosci 2023; 17:1325051. [PMID: 38179183 PMCID: PMC10764494 DOI: 10.3389/fnbeh.2023.1325051] [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: 10/20/2023] [Accepted: 12/01/2023] [Indexed: 01/06/2024] Open
Abstract
Progressive myoclonus epilepsy type 1 (EPM1) is an autosomal recessively inherited childhood-adolescence onset neurodegenerative disease caused by mutations in the cystatin B (CSTB gene). The key clinical manifestation in EPM1 is progressive, stimulus-sensitive, in particular action-induced myoclonus. The cystatin B-deficient mouse model, Cstb-/-, has been described to present with myoclonic seizures and progressive ataxia. Here we describe results from in-depth behavioral phenotyping of the Cstb-/- mouse model in pure isogenic 129S2/SvHsd background covering ages from 1.5 to 6 months. We developed a method for software-assisted detection of myoclonus from video recordings of the Cstb-/- mice. Additionally, we observed that the mice were hyperactive and showed reduced startle response, problems in motor coordination and lack of inhibition. We were, however, not able to demonstrate an ataxic phenotype in them. This detailed behavioral phenotyping of the Cstb-/- mice reveals new aspects of this mouse model. The nature of the motor problems in the Cstb-/- mice seems to be more complex and more resembling the human phenotype than initially described.
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Affiliation(s)
| | - Saara Tegelberg
- Folkhälsan Research Center and Medicum, Medical Faculty, University of Helsinki, Helsinki, Finland
| | | | - Reetta Kälviäinen
- Epilepsy Center, Neuro Center, Kuopio University Hospital, Kuopio, Finland
- Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Anna-Elina Lehesjoki
- Folkhälsan Research Center and Medicum, Medical Faculty, University of Helsinki, Helsinki, Finland
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5
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Trstenjak-Prebanda M, Biasizzo M, Dolinar K, Pirkmajer S, Turk B, Brault V, Herault Y, Kopitar-Jerala N. Stefin B Inhibits NLRP3 Inflammasome Activation via AMPK/mTOR Signalling. Cells 2023; 12:2731. [PMID: 38067160 PMCID: PMC10798374 DOI: 10.3390/cells12232731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 11/24/2023] [Accepted: 11/26/2023] [Indexed: 12/18/2023] Open
Abstract
Stefin B (cystatin B) is an inhibitor of lysosomal and nuclear cysteine cathepsins. The gene for stefin B is located on human chromosome 21 and its expression is upregulated in the brains of individuals with Down syndrome. Biallelic loss-of-function mutations in the stefin B gene lead to Unverricht-Lundborg disease-progressive myoclonus epilepsy type 1 (EPM1) in humans. In our past study, we demonstrated that mice lacking stefin B were significantly more sensitive to sepsis induced by lipopolysaccharide (LPS) and secreted higher levels of interleukin 1-β (IL-1β) due to increased inflammasome activation in bone marrow-derived macrophages. Here, we report lower interleukin 1-β processing and caspase-11 expression in bone marrow-derived macrophages prepared from mice that have an additional copy of the stefin B gene. Increased expression of stefin B downregulated mitochondrial reactive oxygen species (ROS) generation and lowered the NLR family pyrin domain containing 3 (NLRP3) inflammasome activation in macrophages. We determined higher AMP-activated kinase phosphorylation and downregulation of mTOR activity in stefin B trisomic macrophages-macrophages with increased stefin B expression. Our study showed that increased stefin B expression downregulated mitochondrial ROS generation and increased autophagy. The present work contributes to a better understanding of the role of stefin B in regulation of autophagy and inflammasome activation in macrophages and could help to develop new treatments.
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Affiliation(s)
- Mojca Trstenjak-Prebanda
- Department of Biochemistry, Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Monika Biasizzo
- Department of Biochemistry, Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- International Postgraduate School Jožef Stefan, SI-1000 Ljubljana, Slovenia
| | - Klemen Dolinar
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (K.D.); (S.P.)
| | - Sergej Pirkmajer
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (K.D.); (S.P.)
| | - Boris Turk
- Department of Biochemistry, Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Veronique Brault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM, CNRS, Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (V.B.)
| | - Yann Herault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM, CNRS, Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (V.B.)
- Institut Clinique de la Souris, PHENOMIN, CELPHEDIA, INSERM, CNRS, Universite’ de Strasbourg, 67404 Illkirch Graffenstaden, France
| | - Nataša Kopitar-Jerala
- Department of Biochemistry, Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
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Sereesongsaeng N, Burrows JF, Scott CJ, Brix K, Burden RE. Cathepsin V regulates cell cycle progression and histone stability in the nucleus of breast cancer cells. Front Pharmacol 2023; 14:1271435. [PMID: 38026973 PMCID: PMC10657903 DOI: 10.3389/fphar.2023.1271435] [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: 08/02/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction: We previously identified that Cathepsin V (CTSV) expression is associated with poor prognosis in ER+ breast cancer, particularly within the Luminal A subtype. Examination of the molecular role of the protease within Luminal A tumours, revealed that CTSV promotes tumour cell invasion and proliferation, in addition to degradation of the luminal transcription factor, GATA3, via the proteasome. Methods: Cell line models expressing CTSV shRNA or transfected to overexpress CTSV were used to examine the impact of CTSV on cell proliferation by MTT assay and flow cytometry. Western blotting analysis was used to identify the impact of CTSV on histone and chaperone protein expression. Cell fractionation and confocal microscopy was used to illustrate the presence of CTSV in the nuclear compartment. Results: In this work we have identified that CTSV has an impact on breast cancer cell proliferation, with CTSV depleted cells exhibiting delayed progression through the G2/M phase of the cell cycle. Further investigation has revealed that CTSV can control nuclear expression levels of histones H3 and H4 via regulating protein expression of their chaperone sNASP. We have discovered that CTSV is localised to the nuclear compartment in breast tumour cells, mediated by a bipartite nuclear localisation signal (NLS) within the CTSV sequence and that nuclear CTSV is required for cell cycle progression and histone stability in breast tumour cells. Discussion: Collectively these findings support the hypothesis that targeting CTSV may have utility as a novel therapeutic target in ER+ breast cancer by impairing cell cycle progression via manipulating histone stabilisation.
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Affiliation(s)
| | - James F. Burrows
- School of Pharmacy, Medical Biology Centre, Queen’s University Belfast, Belfast, United Kingdom
| | - Christopher J. Scott
- The Patrick G Johnston Centre for Cancer Research, Medical Biology Centre, Queen’s University Belfast, Belfast, United Kingdom
| | - Klaudia Brix
- School of Science, Constructor University, Bremen, Germany
| | - Roberta E. Burden
- School of Pharmacy, Medical Biology Centre, Queen’s University Belfast, Belfast, United Kingdom
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7
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Gorski K, Jackson CB, Nyman TA, Rezov V, Battersby BJ, Lehesjoki AE. Progressive mitochondrial dysfunction in cerebellar synaptosomes of cystatin B-deficient mice. Front Mol Neurosci 2023; 16:1175851. [PMID: 37251643 PMCID: PMC10213208 DOI: 10.3389/fnmol.2023.1175851] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/25/2023] [Indexed: 05/31/2023] Open
Abstract
The involvement of mitochondrial dysfunction in cystatin B (CSTB) deficiency has been suggested, but its role in the onset of neurodegeneration, myoclonus, and ataxia in the CSTB-deficient mouse model (Cstb-/-) is yet unknown. CSTB is an inhibitor of lysosomal and nuclear cysteine cathepsins. In humans, partial loss-of-function mutations cause the progressive myoclonus epilepsy neurodegenerative disorder, EPM1. Here we applied proteome analysis and respirometry on cerebellar synaptosomes from early symptomatic (Cstb-/-) mice to identify the molecular mechanisms involved in the onset of CSTB-deficiency associated neural pathogenesis. Proteome analysis showed that CSTB deficiency is associated with differential expression of mitochondrial and synaptic proteins, and respirometry revealed a progressive impairment in mitochondrial function coinciding with the onset of myoclonus and neurodegeneration in (Cstb-/-) mice. This mitochondrial dysfunction was not associated with alterations in mitochondrial DNA copy number or membrane ultrastructure. Collectively, our results show that CSTB deficiency generates a defect in synaptic mitochondrial bioenergetics that coincides with the onset and progression of the clinical phenotypes, and thus is likely a contributor to the pathogenesis of EPM1.
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Affiliation(s)
- Katarin Gorski
- Folkhälsan Research Center, Helsinki, Finland
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Christopher B. Jackson
- Department of Biochemistry and Developmental Biology, Medicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Tuula A. Nyman
- Department of Immunology, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Veronika Rezov
- Folkhälsan Research Center, Helsinki, Finland
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | | | - Anna-Elina Lehesjoki
- Folkhälsan Research Center, Helsinki, Finland
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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8
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Daura E, Tegelberg S, Hakala P, Lehesjoki AE, Joensuu T. Cystatin B deficiency results in sustained histone H3 tail cleavage in postnatal mouse brain mediated by increased chromatin-associated cathepsin L activity. Front Mol Neurosci 2022; 15:1069122. [DOI: 10.3389/fnmol.2022.1069122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/14/2022] [Indexed: 12/05/2022] Open
Abstract
Cystatin B (CSTB) is a cysteine cathepsin inhibitor whose biallelic loss-of-function mutations in human result in defects in brain development and in neurodegeneration. The physiological function of CSTB is largely unknown, and the mechanisms underlying the human brain diseases remain poorly understood. We previously showed that CSTB modulates the proteolysis of the N-terminal tail of histone H3 (H3cs1) during in vitro neurogenesis. Here we investigated the significance of this mechanism in postnatal mouse brain. Spatiotemporal analysis of H3cs1 intensity showed that while H3cs1 in wild-type (wt) mice was found at varying levels during the first postnatal month, it was virtually absent in adult brain. We further showed that the high level of H3cs1 coincides with chromatin association of de novo synthesized cathepsin L suggesting a role for nuclear cathepsin L in brain development and maturation. On the contrary, the brains of Cstb–/– mice showed sustained H3cs1 proteolysis to adulthood with increased chromatin-associated cathepsin L activity, implying that CSTB regulates chromatin-associated cathepsin L activity in the postnatal mouse brain. As H3 tail proteolysis has been linked to cellular senescence in vitro, we explored the presence of several cellular senescence markers in the maturing Cstb–/– cerebellum, where we see increased levels of H3cs1. While several markers showed alterations in Cstb–/– mice, the results remained inconclusive regarding the association of deficient CSTB function with H3cs1-induced senescence. Together, we identify a molecular role for CSTB in brain with implications for brain development and disease.
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Wei F, Pan B, Diao J, Wang Y, Sheng Y, Gao S. The micronuclear histone H3 clipping in the unicellular eukaryote Tetrahymena thermophila. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:584-594. [PMID: 37078088 PMCID: PMC10077241 DOI: 10.1007/s42995-022-00151-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/07/2022] [Indexed: 05/02/2023]
Abstract
Clipping of the histone H3 N-terminal tail has been implicated in multiple fundamental biological processes for a growing list of eukaryotes. H3 clipping, serving as an irreversible process to permanently remove some post-translational modifications (PTMs), may lead to noticeable changes in chromatin dynamics or gene expression. The eukaryotic model organism Tetrahymena thermophila is among the first few eukaryotes that exhibits H3 clipping activity, wherein the first six amino acids of H3 are cleaved off during vegetative growth. Clipping only occurs in the transcriptionally silent micronucleus of the binucleated T. thermophila, thus offering a unique opportunity to reveal the role of H3 clipping in epigenetic regulation. However, the physiological functions of the truncated H3 and its protease(s) for clipping remain elusive. Here, we review the major findings of H3 clipping in T. thermophila and highlight its association with histone modifications and cell cycle regulation. We also summarize the functions and mechanisms of H3 clipping in other eukaryotes, focusing on the high diversity in terms of protease families and cleavage sites. Finally, we predict several protease candidates in T. thermophila and provide insights for future studies. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-022-00151-0.
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Affiliation(s)
- Fan Wei
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Bo Pan
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Jinghan Diao
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Yuanyuan Wang
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Yalan Sheng
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Shan Gao
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
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10
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Žerovnik E. Human stefin B: from its structure, folding, and aggregation to its function in health and disease. Front Mol Neurosci 2022; 15:1009976. [PMID: 36340691 PMCID: PMC9634419 DOI: 10.3389/fnmol.2022.1009976] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/01/2022] [Indexed: 01/11/2024] Open
Abstract
Mutations in the gene for human stefin B (cystatin B) cause progressive myoclonic epilepsy type 1 (EPM1), a neurodegenerative disorder. The most common change is dodecamer repeats in the promoter region of the gene, though missense and frameshift mutations also appear. Human stefin B primarily acts as a cysteine cathepsin inhibitor, and it also exhibits alternative functions. It plays a protective role against oxidative stress, likely via reducing mitochondrial damage and thus generating fewer mitochondrial reactive oxygen species (ROS). Accordingly, lack of stefin B results in increased inflammation and NLRP3 inflammasome activation, producing more ROS. The protein is cytosolic but also has an important role in the nucleus, where it prevents cleavage of the N terminal part of histone 3 by inhibiting cathepsins L and B and thus regulates transcription and cell cycle. Furthermore, it has been shown that stefin B is oligomeric in cells and that it has a specific role in the physiology of the synapse and in vesicular transport. On the basis of my research team's data on the structure, folding, and aggregation of stefin B, we have proposed that it might regulate proteostasis, possessing a chaperone-like function. In this review, I synthesize these observations and derive some conclusions on possible sources of EPM1 pathology. The interaction partners of stefin B and other gene mutations leading to EPM1-like pathology are discussed and common pathways are pinpointed.
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Affiliation(s)
- Eva Žerovnik
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, Ljubljana, Slovenia
- Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
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11
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MMP-9 drives the melanomagenic transcription program through histone H3 tail proteolysis. Oncogene 2022; 41:560-570. [PMID: 34785776 DOI: 10.1038/s41388-021-02109-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 11/08/2022]
Abstract
Melanoma is a type of skin cancer that develops in pigment-producing melanocytes and often spreads to other parts of the body. Aberrant gene expression has been considered as a crucial step for increasing the risk of melanomagenesis, but how chromatin reorganization contributes to this pathogenic process is still not well understood. Here we report that matrix metalloproteinase 9 (MMP-9) localizes to the nucleus of melanoma cells and potentiates gene expression by proteolytically clipping the histone H3 N-terminal tail (H3NT). From genome-wide studies, we discovered that growth-regulatory genes are selectively targeted and activated by MMP-9-dependent H3NT proteolysis in melanoma cells. MMP-9 cooperates functionally with p300/CBP because MMP-9 cleaves H3NT in a manner that is dependent on p300/CBP-mediated acetylation of H3K18. The functional significance of MMP-9-dependent H3NT proteolysis is further underscored by the fact that RNAi knockdown and small-molecule inhibition of MMP-9 and p300/CBP impede melanomagenic gene expression and melanoma tumor growth. Together, our data establish new functions and mechanisms for nuclear MMP-9 in promoting melanomagenesis and demonstrate how MMP-9-dependent H3NT proteolysis can be exploited to prevent and treat melanoma skin cancer.
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