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Bullock G, Johnson GS, Pattridge SG, Mhlanga-Mutangadura T, Guo J, Cook J, Campbell RS, Vite CH, Katz ML. A Homozygous MAN2B1 Missense Mutation in a Doberman Pinscher Dog with Neurodegeneration, Cytoplasmic Vacuoles, Autofluorescent Storage Granules, and an α-Mannosidase Deficiency. Genes (Basel) 2023; 14:1746. [PMID: 37761886 PMCID: PMC10531151 DOI: 10.3390/genes14091746] [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: 08/09/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
A 7-month-old Doberman Pinscher dog presented with progressive neurological signs and brain atrophy suggestive of a hereditary neurodegenerative disorder. The dog was euthanized due to the progression of disease signs. Microscopic examination of tissues collected at the time of euthanasia revealed massive accumulations of vacuolar inclusions in cells throughout the central nervous system, suggestive of a lysosomal storage disorder. A whole genome sequence generated with DNA from the affected dog contained a likely causal, homozygous missense variant in MAN2B1 that predicted an Asp104Gly amino acid substitution that was unique among whole genome sequences from over 4000 dogs. A lack of detectable α-mannosidase enzyme activity confirmed a diagnosis of a-mannosidosis. In addition to the vacuolar inclusions characteristic of α-mannosidosis, the dog exhibited accumulations of autofluorescent intracellular inclusions in some of the same tissues. The autofluorescence was similar to that which occurs in a group of lysosomal storage disorders called neuronal ceroid lipofuscinoses (NCLs). As in many of the NCLs, some of the storage bodies immunostained strongly for mitochondrial ATP synthase subunit c protein. This protein is not a substrate for α-mannosidase, so its accumulation and the development of storage body autofluorescence were likely due to a generalized impairment of lysosomal function secondary to the accumulation of α-mannosidase substrates. Thus, it appears that storage body autofluorescence and subunit c accumulation are not unique to the NCLs. Consistent with generalized lysosomal impairment, the affected dog exhibited accumulations of intracellular inclusions with varied and complex ultrastructural features characteristic of autophagolysosomes. Impaired autophagic flux may be a general feature of this class of disorders that contributes to disease pathology and could be a target for therapeutic intervention. In addition to storage body accumulation, glial activation indicative of neuroinflammation was observed in the brain and spinal cord of the proband.
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Affiliation(s)
- Garrett Bullock
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Gary S. Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Savannah G. Pattridge
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Tendai Mhlanga-Mutangadura
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Juyuan Guo
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - James Cook
- Specialists in Companion Animal Neurology, Clearwater, FL 33765, USA;
| | - Rebecca S. Campbell
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (R.S.C.); (C.H.V.)
| | - Charles H. Vite
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (R.S.C.); (C.H.V.)
| | - Martin L. Katz
- Neurodegenerative Diseases Research Laboratory, Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
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Guo C, Huang Q, Wang Y, Yao Y, Li J, Chen J, Wu M, Zhang Z, E M, Qi H, Ji P, Liu Q, Zhao D, Su H, Qi W, Li X. Therapeutic application of natural products: NAD + metabolism as potential target. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 114:154768. [PMID: 36948143 DOI: 10.1016/j.phymed.2023.154768] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 03/01/2023] [Accepted: 03/12/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Nicotinamide adenine dinucleotide (NAD+) metabolism is involved in the entire physiopathological process and is critical to human health. Long-term imbalance in NAD+ homeostasis is associated with various diseases, including non-alcoholic fatty liver disease, diabetes mellitus, cardiovascular diseases, neurodegenerative disorders, aging, and cancer, making it a potential target for effective therapeutic strategies. Currently, several natural products that target NAD+ metabolism have been widely reported to have significant therapeutic effects, but systematic summaries are lacking. PURPOSE To summarize the latest findings on the prevention and treatment of various diseases through the regulation of NAD+ metabolism by various natural products in vivo and in vitro models, and evaluate the toxicities of the natural products. METHODS PubMed, Web of Science, and ScienceDirect were searched using the keywords "natural products sources," "toxicology," "NAD+ clinical trials," and "NAD+," and/or paired with "natural products" and "diseases" for studies published within the last decade until January 2023. RESULTS We found that the natural products mainly include phenols (curcumin, cyclocurcumin, 4-hydroxybenzyl alcohol, salvianolic acid B, pterostilbene, EGCG), flavonoids (pinostrobin, apigenin, acacetin, tilianin, kaempferol, quercetin, isoliquiritigenin, luteolin, silybin, hydroxysafflor yellow A, scutellarin), glycosides (salidroside), quinones (emodin, embelin, β-LAPachone, shikonin), terpenoids (notoginsenoside R1, ginsenoside F2, ginsenoside Rd, ginsenoside Rb1, ginsenoside Rg3, thymoquinone, genipin), pyrazines (tetramethylpyrazine), alkaloids (evodiamine, berberine), and phenylpropanoids (ferulic acid). These natural products have antioxidant, energy-producing, anti-inflammatory, anti-apoptotic and anti-aging effects, which mainly influence the NAMPT/NAD+/SIRT, AMPK/SIRT1/PGC-1α, Nrf2/HO-1, PKCs/PARPs/NF-κB, and AMPK/Nrf2/mTOR signaling pathways, thereby regulating NAD+ metabolism to prevent and treat various diseases. These natural products have been shown to be safe, tolerable and have fewer adverse effects in various in vivo and in vitro studies and clinical trials. CONCLUSION We evaluated the toxic effects of natural products and summarized the available clinical trials on NAD+ metabolism, as well as the recent advances in the therapeutic application of natural products targeting NAD+ metabolism, with the aim to provide new insights into the treatment of multiple disorders.
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Affiliation(s)
- Chen Guo
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Qingxia Huang
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China; Research Center of Traditional Chinese Medicine, College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130021, China
| | - Yisa Wang
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Yao Yao
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Jing Li
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Jinjin Chen
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Mingxia Wu
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Zepeng Zhang
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China; Research Center of Traditional Chinese Medicine, College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130021, China
| | - Mingyao E
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Hongyu Qi
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Peng Ji
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Qing Liu
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Daqing Zhao
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Hang Su
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Wenxiu Qi
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China.
| | - Xiangyan Li
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Jilin Provincial Key Laboratory of Bio-Macromolecules of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China.
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Ma LY, Liu SF, Guo YG, Ma ZQ, Li Y, Wang SJ, Niu Y, Li M, Zhai JJ, Shang SH, Lv YL, Qu QM. Diabetes influences the fusion of autophagosomes with lysosomes in SH-SY5Y cells and induces Aβ deposition and cognitive dysfunction in STZ-induced diabetic rats. Behav Brain Res 2023; 442:114286. [PMID: 36610548 DOI: 10.1016/j.bbr.2023.114286] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 12/13/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Diabetes has been regarded as an independent risk factor for Alzheimer's disease (AD). Our previous study found that diabetes activated autophagy, but lysosome function was impaired. Autophagy-lysosome dysfunction may be involved in Aβ deposition in diabetic cognitive impairment. In the present study, we used STZ-induced diabetic rats and SH-SY5Y cells to investigate whether diabetes inhibits autophagosome fusion with lysosomes. We found that in the in vivo study, STZ-induced diabetic rats exhibited cognitive dysfunction, and the lysosome function-related factors CTSL, CTSD, and Rab7 were decreased (P < 0.05). In an in vitro study, the mRFP-GFP-LC3 assay showed that the fusion of autophagosomes with lysosomes was partly blocked in SH-SY5Y cells. High glucose treatment downregulated the number of autophagolysosomes, downregulated CTSD, CTSL, and Rab7 expression (P < 0.05), and then influenced the function of ACP2 to partly block the fusion of autophagosomes and lysosomes to inhibit Aβ clearance. These findings indicate that high glucose treatment affected lysosome function, interfered with the fusion of autophagosomes with lysosomes, and partly blocked autophagic flux to influence Aβ clearance.
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Affiliation(s)
- Lou-Yan Ma
- The Second Department of Geriatrics, Xi'an Ninth Hospital, Xi'an, China
| | - Song-Fang Liu
- Department of Endocrinology, Xi'an Ninth Hospital, Xi'an, China
| | - Ya-Gang Guo
- Department of Laboratory, Xi'an Ninth Hospital, Xi'an, China
| | - Zheng-Quan Ma
- The Second Department of Geriatrics, Xi'an Ninth Hospital, Xi'an, China
| | - Ya Li
- Department of Laboratory, Xi'an Forth Hospital, Xi'an, China
| | - Shu-Jin Wang
- Department of Endocrinology, Xi'an Ninth Hospital, Xi'an, China
| | - Yu Niu
- Department of Endocrinology, Xi'an Ninth Hospital, Xi'an, China
| | - Mo Li
- The Second Department of Geriatrics, Xi'an Ninth Hospital, Xi'an, China
| | - Jia-Jia Zhai
- The Second Department of Geriatrics, Xi'an Ninth Hospital, Xi'an, China
| | - Su-Hang Shang
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Ya-Li Lv
- Department of Neurology, Xi'an Forth Hospital, Xi'an, China.
| | - Qiu-Min Qu
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
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RAB7A GTPase Is Involved in Mitophagosome Formation and Autophagosome-Lysosome Fusion in N2a Cells Treated with the Prion Protein Fragment 106-126. Mol Neurobiol 2023; 60:1391-1407. [PMID: 36449254 DOI: 10.1007/s12035-022-03118-5] [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: 08/05/2022] [Accepted: 11/03/2022] [Indexed: 12/02/2022]
Abstract
Failed communication between mitochondria and lysosomes causes dysfunctional mitochondria, which may induce mitochondria-related neurodegenerative diseases. Here, we show that RAB7A, a small GTPase of the Rab family, mediates the crosstalk between these two important organelles to maintain homeostasis in N2a cells treated with PrP106-126. Specifically, we demonstrate that mitophagy deficiency in N2a cells caused by PrP106-126 is associated with dysregulated RAB7A localization in mitochondria. Cells lacking RAB7A display decreased mitochondrial colocalization with lysosomes and significantly increased mitochondrial protein expression, resulting in inhibited mitophagy. In contrast, overexpression of GTP-bound RAB7A directly induces lysosome colocalization with mitochondria. Further study revealed that GTP-bound RAB7A protects mitochondrial homeostasis by supporting autophagosome biogenesis. Moreover, we suggest that depletion of RAB7A leads to gross morphological changes in lysosomes, which prevents autophagosome-lysosome fusion and interferes with the breakdown of autophagic cargo within lysosomes. Overexpression of GTP-bound RAB7A can also alleviate PrP106-126-induced morphological damage and dysfunction of mitochondria, reducing neuronal apoptosis. Collectively, our data demonstrate that RAB7A successfully drives mitochondria to the autophagosomal lumen for degradation, suggesting that the communication of proteotoxic stress from mitochondria to lysosomes requires RAB7A, as a signaling molecule, to establish a link between the disturbed mitochondrial network and its remodeling. These findings indicate that small molecules regulating mitophagy have the potential to modulate cellular homeostasis and the clinical course of neurodegenerative diseases. Proposed model of mitophagy regulated by RAB7A. (1) Accumulating PrP106-126 induced mitophagy. (2) RAB7A is recruited to mitochondria. (3) ATG5-12 and ATG9A (5) vesicles are recruited to the autophagosome formation sites in a RAB7A-dependent manner. The ATG5-12 complex recruits and anchors LC3-I to form active LC3-II (4), accelerating mitophagosomal formation. The ATG9A vesicles are thought to be a source of membranes for autophagosome assembly. The recruitment of proteins and lipids induces membrane expansion and subsequent closure to form the mitophagosome. (6) Maintenance of the normal low lysosomal PH depends on active (GTP-bound) RAB7A. (7) RAB7A recruits effector molecules responsible for tight membrane interactions, and directly or indirectly, the subsequent autophagosome merges with the lysosome, and the cargo is completely degraded.
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Li Q, Wang L, Ji D, Yu W, Zhang Y, Xiang Y, Zhou C, Wang L, Deng P, Pi H, Lu Y, Ma Q, He M, Zhang L, Yu Z, Deng A. Metformin attenuates cadmium-induced degeneration of spiral ganglion neuron via restoring autophagic flux in primary culture. J Inorg Biochem 2022; 234:111901. [PMID: 35716551 DOI: 10.1016/j.jinorgbio.2022.111901] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 05/31/2022] [Accepted: 06/07/2022] [Indexed: 10/18/2022]
Abstract
Cadmium (Cd), a common environmental and occupational toxicant, is an important risk factor for hearing loss. After exposure, Cd accumulates in the inner ear and induces spiral ganglion neuron (SGN) degeneration; however, the underlying mechanisms are poorly understood. Dysfunctional autophagy has been implicated in many neurodegenerative diseases, including Cd-induced neurotoxicity. Metformin has been validated to confer not only anti-hyperglycaemic but also neuroprotective effects. However, the relationship between autophagy dysfunction, SGN degeneration, and the effect of metformin on Cd-induced SGN neurotoxicity has not yet been established. In this study, we demonstrate that metformin notably attenuates Cd-evoked SGN degeneration by restoring impaired autophagy flux, as evidenced by the suppression of Cd-induced elevation of autophagy markers microtubule-associated protein 1A/1B-light chain 3-II (LC3-II) and autophagy substrate protein p62 in degenerated SGN. Blockage of autophagy flux by chloroquine abolished metformin-induced neuroprotection against Cd-induced neurotoxicity in SGN. The results of this study reveal that autophagy dysfunction is an important component of Cd-induced SGN degeneration, and metformin may be a potential protective agent for attenuating SGN degeneration following Cd exposure.
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Affiliation(s)
- Qian Li
- Department of Otolaryngology Head and Neck Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Liuqian Wang
- Department of Otolaryngology Head and Neck Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Di Ji
- Department of Otolaryngology Head and Neck Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Wei Yu
- Department of Otolaryngology Head and Neck Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yan Zhang
- Department of Otolaryngology Head and Neck Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yanghong Xiang
- Department of Otolaryngology Head and Neck Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Chao Zhou
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Liting Wang
- Biomedical Analysis Center, Army Medical University (Third Military Medical University), Chongqing, China
| | - Ping Deng
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Huifeng Pi
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yonghui Lu
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Qinlong Ma
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Mindi He
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Lei Zhang
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhengping Yu
- Department of Occupational Health, Army Medical University (Third Military Medical University), Chongqing, China
| | - Anchun Deng
- Department of Otolaryngology Head and Neck Surgery, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China.
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Mondal A, Appu AP, Sadhukhan T, Bagh MB, Previde RM, Sadhukhan S, Stojilkovic S, Liu A, Mukherjee AB. Ppt1-deficiency dysregulates lysosomal Ca ++ homeostasis contributing to pathogenesis in a mouse model of CLN1 disease. J Inherit Metab Dis 2022; 45:635-656. [PMID: 35150145 PMCID: PMC9090967 DOI: 10.1002/jimd.12485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/05/2022] [Accepted: 02/08/2022] [Indexed: 11/08/2022]
Abstract
Inactivating mutations in the PPT1 gene encoding palmitoyl-protein thioesterase-1 (PPT1) underlie the CLN1 disease, a devastating neurodegenerative lysosomal storage disorder. The mechanism of pathogenesis underlying CLN1 disease has remained elusive. PPT1 is a lysosomal enzyme, which catalyzes the removal of palmitate from S-palmitoylated proteins (constituents of ceroid lipofuscin) facilitating their degradation and clearance by lysosomal hydrolases. Thus, it has been proposed that Ppt1-deficiency leads to lysosomal accumulation of ceroid lipofuscin leading to CLN1 disease. While S-palmitoylation is catalyzed by palmitoyl acyltransferases (called ZDHHCs), palmitoyl-protein thioesterases (PPTs) depalmitoylate these proteins. We sought to determine the mechanism by which Ppt1-deficiency may impair lysosomal degradative function leading to infantile neuronal ceroid lipofuscinosis pathogenesis. Here, we report that in Ppt1-/- mice, which mimic CLN1 disease, low level of inositol 3-phosphate receptor-1 (IP3R1) that mediates Ca++ transport from the endoplasmic reticulum to the lysosome dysregulated lysosomal Ca++ homeostasis. Intriguingly, the transcription factor nuclear factor of activated T-cells, cytoplasmic 4 (NFATC4), which regulates IP3R1-expression, required S-palmitoylation for trafficking from the cytoplasm to the nucleus. We identified two palmitoyl acyltransferases, ZDHHC4 and ZDHHC8, which catalyzed S-palmitoylation of NFATC4. Notably, in Ppt1-/- mice, reduced ZDHHC4 and ZDHHC8 levels markedly lowered S-palmitoylated NFATC4 (active) in the nucleus, which inhibited IP3R1-expression, thereby dysregulating lysosomal Ca++ homeostasis. Consequently, Ca++ -dependent lysosomal enzyme activities were markedly suppressed. Impaired lysosomal degradative function impaired autophagy, which caused lysosomal storage of undigested cargo. Importantly, IP3R1-overexpression in Ppt1-/- mouse fibroblasts ameliorated this defect. Our results reveal a previously unrecognized role of Ppt1 in regulating lysosomal Ca++ homeostasis and suggest that this defect contributes to pathogenesis of CLN1 disease.
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Affiliation(s)
- Avisek Mondal
- Section on Developmental Genetics, Division of Translational Medicine
| | - Abhilash P. Appu
- Section on Developmental Genetics, Division of Translational Medicine
| | - Tamal Sadhukhan
- Section on Developmental Genetics, Division of Translational Medicine
| | - Maria B. Bagh
- Section on Developmental Genetics, Division of Translational Medicine
| | - Rafael M. Previde
- Section on Cellular Signaling, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830
| | | | - Stanko Stojilkovic
- Section on Cellular Signaling, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830
| | - Aiyi Liu
- Biostatistics and Bioinformatics Branch, Division of Intramural Population Health Research, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830
| | - Anil B Mukherjee
- Section on Developmental Genetics, Division of Translational Medicine
- Correspondence to AM () or ABM ()
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Simonati A, Williams RE. Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview. Front Neurol 2022; 13:811686. [PMID: 35359645 PMCID: PMC8961688 DOI: 10.3389/fneur.2022.811686] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/11/2022] [Indexed: 01/04/2023] Open
Abstract
The main aim of this review is to summarize the current state-of-art in the field of childhood Neuronal Ceroid Lipofuscinosis (NCL), a group of rare neurodegenerative disorders. These are genetic diseases associated with the formation of toxic endo-lysosomal storage. Following a brief historical review of the evolution of NCL definition, a clinically-oriented approach is used describing how the early symptoms and signs affecting motor, visual, cognitive domains, and including seizures, may lead clinicians to a rapid molecular diagnosis, avoiding the long diagnostic odyssey commonly observed. We go on to focus on recent advances in NCL research and summarize contributions to knowledge of the pathogenic mechanisms underlying NCL. We describe the large variety of experimental models which have aided this research, as well as the most recent technological developments which have shed light on the main mechanisms involved in the cellular pathology, such as apoptosis and autophagy. The search for innovative therapies is described. Translation of experimental data into therapeutic approaches is being established for several of the NCLs, and one drug is now commercially available. Lastly, we show the importance of palliative care and symptomatic treatments which are still the main therapeutic interventions.
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Affiliation(s)
- Alessandro Simonati
- Departments of Surgery, Dentistry, Paediatrics, and Gynaecology, School of Medicine, University of Verona, Verona, Italy
- Department of Clinical Neuroscience, AOUI-VR, Verona, Italy
- *Correspondence: Alessandro Simonati
| | - Ruth E. Williams
- Department of Children's Neuroscience, Evelina London Children's Hospital, London, United Kingdom
- Ruth E. Williams
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Kim WD, Wilson-Smillie MLDM, Thanabalasingam A, Lefrancois S, Cotman SL, Huber RJ. Autophagy in the Neuronal Ceroid Lipofuscinoses (Batten Disease). Front Cell Dev Biol 2022; 10:812728. [PMID: 35252181 PMCID: PMC8888908 DOI: 10.3389/fcell.2022.812728] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs), also referred to as Batten disease, are a family of neurodegenerative diseases that affect all age groups and ethnicities around the globe. At least a dozen NCL subtypes have been identified that are each linked to a mutation in a distinct ceroid lipofuscinosis neuronal (CLN) gene. Mutations in CLN genes cause the accumulation of autofluorescent lipoprotein aggregates, called ceroid lipofuscin, in neurons and other cell types outside the central nervous system. The mechanisms regulating the accumulation of this material are not entirely known. The CLN genes encode cytosolic, lysosomal, and integral membrane proteins that are associated with a variety of cellular processes, and accumulated evidence suggests they participate in shared or convergent biological pathways. Research across a variety of non-mammalian and mammalian model systems clearly supports an effect of CLN gene mutations on autophagy, suggesting that autophagy plays an essential role in the development and progression of the NCLs. In this review, we summarize research linking the autophagy pathway to the NCLs to guide future work that further elucidates the contribution of altered autophagy to NCL pathology.
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Affiliation(s)
- William D. Kim
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | | | - Aruban Thanabalasingam
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | - Stephane Lefrancois
- Centre Armand-Frappier Santé Biotechnologie, Institut National de La Recherche Scientifique, Laval, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
- Centre D'Excellence en Recherche sur Les Maladies Orphelines–Fondation Courtois (CERMO-FC), Université Du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Susan L. Cotman
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA, United States
| | - Robert J. Huber
- Department of Biology, Trent University, Peterborough, ON, Canada
- *Correspondence: Robert J. Huber,
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9
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Lin H. Protein cysteine palmitoylation in immunity and inflammation. FEBS J 2021; 288:7043-7059. [PMID: 33506611 PMCID: PMC8872633 DOI: 10.1111/febs.15728] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/24/2020] [Accepted: 01/25/2021] [Indexed: 07/24/2023]
Abstract
Protein cysteine palmitoylation, or S-palmitoylation, has been known for about 40 years, and thousands of proteins in humans are known to be modified. Because of the large number of proteins modified, the importance and physiological functions of S-palmitoylation are enormous. However, most of the known physiological functions of S-palmitoylation can be broadly classified into two categories, neurological or immunological. This review provides a summary on the function of S-palmitoylation from the immunological perspective. Several important immune signaling pathways are discussed, including STING, NOD1/2, JAK-STAT in cytokine signaling, T-cell receptor signaling, chemotactic GPCR signaling, apoptosis, phagocytosis, and endothelial and epithelial integrity. This review is not meant to be comprehensive, but rather focuses on specific examples to highlight the versatility of palmitoylation in regulating immune signaling, as well as the potential and challenges of targeting palmitoylation to treat immune diseases.
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Affiliation(s)
- Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
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10
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On the cusp of cures: Breakthroughs in Batten disease research. Curr Opin Neurobiol 2021; 72:48-54. [PMID: 34571324 DOI: 10.1016/j.conb.2021.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 12/27/2022]
Abstract
Batten disease is a family of rare, lysosomal disorders caused by mutations in one of at least 13 genes, which encode a diverse set of lysosomal and extralysosomal proteins. Despite decades of research, the development of effective therapies has remained intractable. But now, the field is experiencing rapid, unprecedented progress on multiple fronts. New tools are providing insights into previously unsolvable problems, with molecular functions now known for nine Batten disease proteins. Protein interactome data are uncovering potential functional overlap between several Batten disease proteins, providing long-sought links between seemingly disparate proteins. Understanding of cellular etiology is elucidating contributions from and interactions between various CNS cell types. Collectively, this explosion in insight is hastening an unparalleled period of therapeutic breakthroughs, with multiple therapies showing great promise in preclinical and clinical studies. The coming years will provide a continuation of this rapid progress, with the promise of effective treatments giving patients hope.
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11
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Augustine EF, Adams HR, de Los Reyes E, Drago K, Frazier M, Guelbert N, Laine M, Levin T, Mink JW, Nickel M, Peifer D, Schulz A, Simonati A, Topcu M, Turunen JA, Williams R, Wirrell EC, King S. Management of CLN1 Disease: International Clinical Consensus. Pediatr Neurol 2021; 120:38-51. [PMID: 34000449 DOI: 10.1016/j.pediatrneurol.2021.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 04/01/2021] [Accepted: 04/04/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND CLN1 disease (neuronal ceroid lipofuscinosis type 1) is a rare, genetic, neurodegenerative lysosomal storage disorder caused by palmitoyl-protein thioesterase 1 (PPT1) enzyme deficiency. Clinical features include developmental delay, psychomotor regression, seizures, ataxia, movement disorders, visual impairment, and early death. In general, the later the age at symptom onset, the more protracted the disease course. We sought to evaluate current evidence and to develop expert practice consensus to support clinicians who have not previously encountered patients with this rare disease. METHODS We searched the literature for guidelines and evidence to support clinical practice recommendations. We surveyed CLN1 disease experts and caregivers regarding their experiences and recommendations, and a meeting of experts was conducted to ascertain points of consensus and clinical practice differences. RESULTS We found a limited evidence base for treatment and no clinical management guidelines specific to CLN1 disease. Fifteen CLN1 disease experts and 39 caregivers responded to the surveys, and 14 experts met to develop consensus-based recommendations. The resulting management recommendations are uniquely informed by family perspectives, due to the inclusion of caregiver and advocate perspectives. A family-centered approach is supported, and individualized, multidisciplinary care is emphasized in the recommendations. Ascertainment of the specific CLN1 disease phenotype (infantile-, late infantile-, juvenile-, or adult-onset) is of key importance in informing the anticipated clinical course, prognosis, and care needs. Goals and strategies should be periodically reevaluated and adapted to patients' current needs, with a primary aim of optimizing patient and family quality of life.
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Affiliation(s)
- Erika F Augustine
- Department of Neurology and Neurogenetics, Kennedy Krieger Institute, Baltimore, Maryland; Departments of Neurology and Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York.
| | - Heather R Adams
- Departments of Neurology and Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Emily de Los Reyes
- Department of Pediatrics and Neurology, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio
| | | | | | - Norberto Guelbert
- Metabolic Diseases Section, Children's Hospital of Cordoba, Cordoba, Argentina
| | - Minna Laine
- Department of Pediatric Neurology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Tanya Levin
- Medical Writing Consultant, Atlanta, Georgia
| | - Jonathan W Mink
- Departments of Neurology, Neuroscience, and Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Miriam Nickel
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Angela Schulz
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alessandro Simonati
- Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona School of Medicine, Verona, Italy
| | - Meral Topcu
- Professor Emeritus, Department of Pediatric Neurology, Hacettepe University, Ankara, Turkey
| | - Joni A Turunen
- Department of Ophthalmology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Ruth Williams
- Children's Neurosciences Centre, Evelina London Children's Hospital, London, United Kingdom
| | - Elaine C Wirrell
- Divisions of Epilepsy and Child and Adolescent Neurology, Department of Neurology, Mayo Clinic, Rochester, Minnesota
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12
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Gupta R, Sahu M, Srivastava D, Tiwari S, Ambasta RK, Kumar P. Post-translational modifications: Regulators of neurodegenerative proteinopathies. Ageing Res Rev 2021; 68:101336. [PMID: 33775891 DOI: 10.1016/j.arr.2021.101336] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 03/10/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
One of the hallmark features in the neurodegenerative disorders (NDDs) is the accumulation of aggregated and/or non-functional protein in the cellular milieu. Post-translational modifications (PTMs) are an essential regulator of non-functional protein aggregation in the pathogenesis of NDDs. Any alteration in the post-translational mechanism and the protein quality control system, for instance, molecular chaperone, ubiquitin-proteasome system, autophagy-lysosomal degradation pathway, enhances the accumulation of misfolded protein, which causes neuronal dysfunction. Post-translational modification plays many roles in protein turnover rate, accumulation of aggregate and can also help in the degradation of disease-causing toxic metabolites. PTMs such as acetylation, glycosylation, phosphorylation, ubiquitination, palmitoylation, SUMOylation, nitration, oxidation, and many others regulate protein homeostasis, which includes protein structure, functions and aggregation propensity. Different studies demonstrated the involvement of PTMs in the regulation of signaling cascades such as PI3K/Akt/GSK3β, MAPK cascade, AMPK pathway, and Wnt signaling pathway in the pathogenesis of NDDs. Further, mounting evidence suggests that targeting different PTMs with small chemical molecules, which acts as an inhibitor or activator, reverse misfolded protein accumulation and thus enhances the neuroprotection. Herein, we briefly discuss the protein aggregation and various domain structures of different proteins involved in the NDDs, indicating critical amino acid residues where PTMs occur. We also describe the implementation and involvement of various PTMs on signaling cascade and cellular processes in NDDs. Lastly, we implement our current understanding of the therapeutic importance of PTMs in neurodegeneration, along with emerging techniques targeting various PTMs.
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13
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Pesaola F, Quassollo G, Venier AC, De Paul AL, Noher I, Bisbal M. The neuronal ceroid lipofuscinosis-related protein CLN8 regulates endo-lysosomal dynamics and dendritic morphology. Biol Cell 2021; 113:419-437. [PMID: 34021618 DOI: 10.1111/boc.202000016] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/18/2021] [Accepted: 05/22/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND INFORMATION The endo-lysosomal system (ELS) comprises a set of membranous organelles responsible for transporting intracellular and extracellular components within cells. Defects in lysosomal proteins usually affect a large variety of processes and underlie many diseases, most of them with a strong neuronal impact. Mutations in the endoplasmic reticulum-resident CLN8 protein cause CLN8 disease. This condition is one of the 14 known neuronal ceroid lipofuscinoses (NCLs), a group of inherited diseases characterised by accumulation of lipofuscin-like pigments within lysosomes. Besides mediating the transport of soluble lysosomal proteins, recent research suggested a role for CLN8 in the transport of vesicles and lipids, and autophagy. However, the consequences of CLN8 deficiency on ELS structure and activity, as well as the potential impact on neuronal development, remain poorly characterised. Therefore, we performed CLN8 knockdown in neuronal and non-neuronal cell models to analyse structural, dynamic and functional changes in the ELS and to assess the impact of CLN8 deficiency on axodendritic development. RESULTS CLN8 knockdown increased the size of the Golgi apparatus, the number of mobile vesicles and the speed of endo-lysosomes. Using the fluorescent fusion protein mApple-LAMP1-pHluorin, we detected significant lysosomal alkalisation in CLN8-deficient cells. In turn, experiments in primary rat hippocampal neurons showed that CLN8 deficiency decreased the complexity and size of the somatodendritic compartment. CONCLUSIONS Our results suggest the participation of CLN8 in vesicular distribution, lysosomal pH and normal development of the dendritic tree. We speculate that the defects triggered by CLN8 deficiency on ELS structure and dynamics underlie morphological alterations in neurons, which ultimately lead to the characteristic neurodegeneration observed in this NCL. SIGNIFICANCE This is, to our knowledge, the first characterisation of the effects of CLN8 dysfunction on the structure and dynamics of the ELS. Moreover, our findings suggest a novel role for CLN8 in somatodendritic development, which may account at least in part for the neuropathological manifestations associated with CLN8 disease.
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Affiliation(s)
- Favio Pesaola
- Programa de Investigación Translacional de Lipofuscinosis Ceroidea Neuronal, Hospital de Niños de Córdoba, Córdoba, 5014, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Médicas "Mercedes y Martin Ferreyra"- IMMF-UNC-CONICET, Laboratorio de Neurobiología, Av. Friuli 2434, 5016 Córdoba, Argentina, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina
| | - Gonzalo Quassollo
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Médicas "Mercedes y Martin Ferreyra"- IMMF-UNC-CONICET, Laboratorio de Neurobiología, Av. Friuli 2434, 5016 Córdoba, Argentina, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina
| | - Ana Clara Venier
- Programa de Investigación Translacional de Lipofuscinosis Ceroidea Neuronal, Hospital de Niños de Córdoba, Córdoba, 5014, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigación en Ciencias de la Salud (INICSA), Bv. de la Reforma y Enfermera Gordillo, Ciudad Universitaria, Córdoba, 5016, Argentina
| | - Ana Lucía De Paul
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigación en Ciencias de la Salud (INICSA), Bv. de la Reforma y Enfermera Gordillo, Ciudad Universitaria, Córdoba, 5016, Argentina.,Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica, Bv. de la Reforma y Enfermera Gordillo, Ciudad Universitaria, Córdoba, 5016, Argentina
| | - Ines Noher
- Programa de Investigación Translacional de Lipofuscinosis Ceroidea Neuronal, Hospital de Niños de Córdoba, Córdoba, 5014, Argentina
| | - Mariano Bisbal
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Médicas "Mercedes y Martin Ferreyra"- IMMF-UNC-CONICET, Laboratorio de Neurobiología, Av. Friuli 2434, 5016 Córdoba, Argentina, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina.,Instituto Universitario de Ciencias Biomédicas Córdoba, Córdoba, 5016, Argentina
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14
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Vergoten G, Bailly C. Binding of hydroxychloroquine and chloroquine dimers to palmitoyl-protein thioesterase 1 (PPT1) and its glycosylated forms: a computational approach. J Biomol Struct Dyn 2021; 40:8197-8205. [PMID: 33876698 DOI: 10.1080/07391102.2021.1908167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The lysosomal enzyme palmitoyl-protein thioesterase 1 (PPT1) removes thioester-linked fatty acid groups from membrane-bound proteins to facilitate their proteolysis. A lack of PPT1 (due to gene mutations) causes the progressive death of cortical neurons and is responsible for infantile neural ceroid lipofuscinosis (INCL), a severe neurodegenerative disorder in children. Conversely, PPT1 is often over-expressed in cancer, and considered as a valid target to control tumor growth. Potent and selective inhibitors of PPT1 have been designed, in particular 4-amino-7-chloro-quinoline derivatives such as hydroxychloroquine (HCQ) and the dimeric analogues Lys05 and DC661. We have modeled the interaction of these three compounds with the enzyme, taking advantage of the PPT1 crystallographic structure. The molecules can fit into the palmitate site of the protein, with the dimeric compounds forming more stable complexes than the monomer. But the molecular modeling suggests that the most favorable binding sites are located outside the active site. Two sites centered on residues Met112 and Gln144 were identified, offering suitable cavities for drug binding. According to the calculated empirical energies of interaction (ΔE), the dimer DC661 forms the most stable complex at site Met112 of palmitate-bound PPT1. N-glycosylated forms of PPT1 were elaborated. Paucimannosidic glycans (M2FA and M3F) and a bulkier tetra-antennary complex glycan were introduced at asparagine residues N197, N212 and N232. These N-glycans do not impede drug binding, thus suggesting that all glycoforms of PPT1 can be targeted with these compounds.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Gérard Vergoten
- Inserm, INFINITE - U1286, Institut de Chimie Pharmaceutique Albert Lespagnol (ICPAL), Faculté de Pharmacie, University of Lille, Lille, France
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15
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Abstract
Our cells are comprised of billions of proteins, lipids, and other small molecules packed into their respective subcellular organelles, with the daunting task of maintaining cellular homeostasis over a lifetime. However, it is becoming increasingly evident that organelles do not act as autonomous discrete units but rather as interconnected hubs that engage in extensive communication through membrane contacts. In the last few years, our understanding of how these contacts coordinate organelle function has redefined our view of the cell. This review aims to present novel findings on the cellular interorganelle communication network and how its dysfunction may contribute to aging and neurodegeneration. The consequences of disturbed interorganellar communication are intimately linked with age-related pathologies. Given that both aging and neurodegenerative diseases are characterized by the concomitant failure of multiple cellular pathways, coordination of organelle communication and function could represent an emerging regulatory mechanism critical for long-term cellular homeostasis. We anticipate that defining the relationships between interorganelle communication, aging, and neurodegeneration will open new avenues for therapeutics.
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Affiliation(s)
- Maja Petkovic
- Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA
| | - Caitlin E O'Brien
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA
| | - Yuh Nung Jan
- Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
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