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Fu D, Luo J, Wu Y, Zhang L, Li L, Chen H, Wen T, Fu Y, Xiong W. Angiotensin II-induced calcium overload affects mitochondrial functions in cardiac hypertrophy by targeting the USP2/MFN2 axis. Mol Cell Endocrinol 2023; 571:111938. [PMID: 37100191 DOI: 10.1016/j.mce.2023.111938] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/12/2023] [Accepted: 04/23/2023] [Indexed: 04/28/2023]
Abstract
Ubiquitination, a common type of post-translational modification, is known to affect various diseases, including cardiac hypertrophy. Ubiquitin-specific peptidase 2 (USP2) plays a crucial role in regulating cell functions, but its role in cardiac functions remains elusive. The present study aims to investigate the mechanism of USP2 in cardiac hypertrophy. Animal and cell models of cardiac hypertrophy were established using Angiotensin II (Ang II) induction. Our experiments revealed that Ang II induced USP2 downregulation in the in vitro and in vivo models. USP2 overexpression suppressed the degree of cardiac hypertrophy (decreased ANP, BNP, and β-MHC mRNA levels, cell surface area, and ratio of protein/DNA), calcium overload (decreased Ca2+ concentration and t-CaMKⅡ and p-CaMKⅡ, and increased SERCA2), and mitochondrial dysfunction (decreased MDA and ROS and increased MFN1, ATP, MMP, and complex Ⅰ and II) both in vitro and in vivo. Mechanically, USP2 interacted with MFN2 and improved the protein level of MFN2 through deubiquitination. Rescue experiments confirmed that MFN2 downregulation neutralized the protective role of USP2 overexpression in cardiac hypertrophy. Overall, our findings suggested that USP2 overexpression mediated deubiquitination to upregulate MFN2, thus alleviating calcium overload-induced mitochondrial dysfunction and cardiac hypertrophy.
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Affiliation(s)
- Daoyao Fu
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Jing Luo
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Yanze Wu
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Liuping Zhang
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Lei Li
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Hui Chen
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Tong Wen
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Yongnan Fu
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China
| | - Wenjun Xiong
- Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China; Hypertension Research Institute of Jiangxi Province, Nanchang, 330006, Jiangxi, China.
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Zhuang D, Zhang R, Liu H, Dai Y. A Small Natural Molecule S3 Protects Retinal Ganglion Cells and Promotes Parkin-Mediated Mitophagy against Excitotoxicity. Molecules 2022; 27:molecules27154957. [PMID: 35956907 PMCID: PMC9370668 DOI: 10.3390/molecules27154957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/24/2022] [Accepted: 08/01/2022] [Indexed: 02/04/2023] Open
Abstract
Glutamate excitotoxicity may contribute to retinal ganglion cell (RGC) degeneration in glaucoma and other optic neuropathies, leading to irreversible blindness. Growing evidence has linked impaired mitochondrial quality control with RGCs degeneration, while parkin, an E3 ubiquitin ligase, has proved to be protective and promotes mitophagy in RGCs against excitotoxicity. The purpose of this study was to explore whether a small molecule S3 could modulate parkin-mediated mitophagy and has therapeutic potential for RGCs. The results showed that as an inhibitor of deubiquitinase USP30, S3 protected cultured RGCs and improved mitochondrial health against NMDA-induced excitotoxicity. Administration of S3 promoted the parkin expression and its downstream mitophagy-related proteins in RGCs. An upregulated ubiquitination level of Mfn2 and protein level of OPA1 were also observed in S3-treated RGCs, while parkin knockdown resulted in a major loss of the protective effect of S3 on RGCs under excitotoxicity. These findings demonstrated that S3 promoted RGC survival mainly through enhancing parkin-mediated mitophagy against excitotoxicity. The neuroprotective value of S3 in glaucoma and other optic neuropathies deserves further investigation.
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Affiliation(s)
- Dongli Zhuang
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai 200031, China
| | - Rong Zhang
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai 200031, China
| | - Haiyang Liu
- The State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China
| | - Yi Dai
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai 200031, China
- Correspondence:
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Goiran T, Eldeeb MA, Zorca CE, Fon EA. Hallmarks and Molecular Tools for the Study of Mitophagy in Parkinson’s Disease. Cells 2022; 11:cells11132097. [PMID: 35805181 PMCID: PMC9265644 DOI: 10.3390/cells11132097] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 01/27/2023] Open
Abstract
The best-known hallmarks of Parkinson’s disease (PD) are the motor deficits that result from the degeneration of dopaminergic neurons in the substantia nigra. Dopaminergic neurons are thought to be particularly susceptible to mitochondrial dysfunction. As such, for their survival, they rely on the elaborate quality control mechanisms that have evolved in mammalian cells to monitor mitochondrial function and eliminate dysfunctional mitochondria. Mitophagy is a specialized type of autophagy that mediates the selective removal of damaged mitochondria from cells, with the net effect of dampening the toxicity arising from these dysfunctional organelles. Despite an increasing understanding of the molecular mechanisms that regulate the removal of damaged mitochondria, the detailed molecular link to PD pathophysiology is still not entirely clear. Herein, we review the fundamental molecular pathways involved in PINK1/Parkin-mediated and receptor-mediated mitophagy, the evidence for the dysfunction of these pathways in PD, and recently-developed state-of-the art assays for measuring mitophagy in vitro and in vivo.
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Eldeeb MA, Esmaili M, Hassan M, Ragheb MA. The Role of PTEN-L in Modulating PINK1-Parkin-Mediated Mitophagy. Neurotox Res 2022; 40:1103-1114. [PMID: 35699891 DOI: 10.1007/s12640-022-00475-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 12/27/2021] [Accepted: 01/13/2022] [Indexed: 11/24/2022]
Abstract
An inherent challenge that mitochondria face is the continuous exposure to diverse stresses which increase their likelihood of dysregulation. In response, human cells have evolved sophisticated quality control mechanisms to identify and eliminate abnormal dysfunctional mitochondria. One pivotal mitochondrial quality control pathway is PINK1/Parkin-dependent mitophagy which mediates the selective removal of the dysfunctional mitochondria from the cell by autophagy. PTEN-induced putative kinase 1 (PINK1) is a mitochondrial Ser/Thr kinase that was originally identified as a gene responsible for autosomal recessive early-onset Parkinson's disease (PD). Notably, upon failure of mitochondrial import, Parkin, another autosomal-recessive PD gene, is recruited to mitochondria and mediates the autophagic clearance of deregulated mitochondria. Importantly, recruitment of Parkin to damaged mitochondria hinges on the accumulation of PINK1 on the outer mitochondrial membrane (OMM). Normally, PINK1 is imported from the cytosol through the translocase of the outer membrane (TOM) complex, a large multimeric channel responsible for the import of most mitochondrial proteins. After import, PINK1 is rapidly degraded. Thus, at steady-state, PINK1 levels are kept low. However, upon mitochondrial import failure, PINK1 accumulates and forms a high-molecular weight > 700 kDa complex with TOM on the OMM. Thus, PINK1 functions as sensor, tagging dysfunctional mitochondria for Parkin-mediated mitophagy. Although much has been learned about the function of PINK1 in mitophagy, the biochemical and structural basis of negative regulation of PINK1 operation and functions is far from clear. Recent work unveiled new players as PTEN-l as negative regulator of PINK1 function. Herein, we review key aspects of mitophagy and PINK1/Parkin-mediated mitophagy with highlighting the role of negative regulation of PINK1 function and presenting some of the key future directions in PD cell biology.
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Affiliation(s)
- Mohamed A Eldeeb
- Department of Neurology and Neurosurgery, Montreal Neurological Institute McGill University, Montreal, QC, Canada. .,Department of Chemistry, Biochemistry Division, Cairo University, Giza, Egypt.
| | - Mansoore Esmaili
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Marwa Hassan
- Department of Chemistry, Biochemistry Division, Cairo University, Giza, Egypt
| | - Mohamed A Ragheb
- Department of Chemistry, Biochemistry Division, Cairo University, Giza, Egypt
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Eldeeb MA, Ragheb MA, Soliman MH, Fahlman RP. Regulation of Neurodegeneration-associated Protein Fragments by the N-degron Pathways. Neurotox Res 2022; 40:298-318. [PMID: 35043375 DOI: 10.1007/s12640-021-00396-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/20/2021] [Accepted: 07/20/2021] [Indexed: 12/20/2022]
Abstract
Among the most salient features that underpin the development of aging-related neurodegenerative disorders are the accumulation of protein aggregates and the decrease in cellular degradation capacity. Mammalian cells have evolved sophisticated quality control mechanisms to repair or eliminate the otherwise abnormal or misfolded proteins. Chaperones identify unstable or abnormal conformations in proteins and often help them regain their correct conformation. However, if repair is not an option, abnormal proteins are selectively degraded to prevent undesired interactions with other proteins or oligomerization into toxic multimeric complexes. The autophagic-lysosomal system and the ubiquitin-proteasome system mediate the selective and targeted degradation of abnormal or aberrant protein fragments. Despite an increasing understanding regarding the molecular responses that counteract the formation and clearance of dysfunctional protein aggregates, the role of N-degrons in these processes is poorly understood. Previous work demonstrated that the Arg-N-end rule degradation pathway (Arg-N-degron pathway) mediates the degradation of neurodegeneration-associated proteins, thereby regulating crucial signaling hubs that modulate the progression of neurodegenerative diseases. Herein, we discuss the functional interconnection between N-degron pathways and proteins associated with neurodegenerative disorders, including Alzheimer's disease, amyotrophic lateral sclerosis, and Parkinson's disease. We also highlight some future prospects related to how the molecular insights gained from these processes will help unveil novel therapeutic approaches.
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Affiliation(s)
- Mohamed A Eldeeb
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt. .,Neurodegenerative Diseases Group, Department of Neurology and Neurosurgery, McGill Parkinson Program, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| | - Mohamed A Ragheb
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Marwa H Soliman
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Richard P Fahlman
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
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Agarwal E, Goldman AR, Tang HY, Kossenkov AV, Ghosh JC, Languino LR, Vaira V, Speicher DW, Altieri DC. A cancer ubiquitome landscape identifies metabolic reprogramming as target of Parkin tumor suppression. SCIENCE ADVANCES 2021; 7:7/35/eabg7287. [PMID: 34433563 PMCID: PMC8386929 DOI: 10.1126/sciadv.abg7287] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 07/02/2021] [Indexed: 05/16/2023]
Abstract
Changes in metabolism that affect mitochondrial and glycolytic networks are hallmarks of cancer, but their impact in disease is still elusive. Using global proteomics and ubiquitome screens, we now show that Parkin, an E3 ubiquitin ligase and key effector of mitophagy altered in Parkinson's disease, shuts off mitochondrial dynamics and inhibits the non-oxidative phase of the pentose phosphate pathway. This blocks tumor cell movements, creates metabolic and oxidative stress, and inhibits primary and metastatic tumor growth. Uniformly down-regulated in cancer patients, Parkin tumor suppression requires its E3 ligase function, is reversed by antioxidants, and is independent of mitophagy. These data demonstrate that cancer metabolic networks are potent oncogenes directly targeted by endogenous tumor suppression.
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Affiliation(s)
- Ekta Agarwal
- Prostate Cancer Discovery and Development Program, The Wistar Institute, Philadelphia, PA 19104, USA
- Immunology, Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Aaron R Goldman
- Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Hsin-Yao Tang
- Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Andrew V Kossenkov
- Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Jagadish C Ghosh
- Prostate Cancer Discovery and Development Program, The Wistar Institute, Philadelphia, PA 19104, USA
- Immunology, Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Lucia R Languino
- Department of Cancer Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Valentina Vaira
- Division of Pathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan 20122, Italy
- Department of Pathophysiology and Transplantation, University of Milan, Milan 20122, Italy
| | - David W Speicher
- Prostate Cancer Discovery and Development Program, The Wistar Institute, Philadelphia, PA 19104, USA
- Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Dario C Altieri
- Prostate Cancer Discovery and Development Program, The Wistar Institute, Philadelphia, PA 19104, USA.
- Immunology, Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, PA 19104, USA
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7
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Ragheb MA, Soliman MH, Elzayat EM, Mohamed MS, El-Ekiaby N, Abdelaziz AI, Abdel-Wahab AHA. MicroRNA-520c-3p Modulates Doxorubicin-Chemosensitivity in HepG2 Cells. Anticancer Agents Med Chem 2021; 21:237-245. [PMID: 32357822 DOI: 10.2174/1871520620666200502004817] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/11/2019] [Accepted: 12/11/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Doxorubicin (DOX) is one of the most common drugs used in cancer therapy, including Hepatocellular Carcinoma (HCC). Drug resistance is one of chemotherapy's significant problems. Emerging studies have shown that microRNAs (miRNAs) could participate in regulating this mechanism. Nevertheless, the impact of miRNAs on HCC chemoresistance is still enigmatic. OBJECTIVE Investigating the role of microRNA-520c-3p (miR-520c-3p) in the enhancement of the anti-tumor effect of DOX against HepG2 cells. METHODS Expression profile for liver-related miRNAs (384 miRNAs) has been analyzed on HepG2 cells treated with DOX using qRT-PCR. miR-520c-3p, the most deregulated miRNA, was selected for combination treatment with DOX. The expression level for LEF1, CDK2, CDH1, VIM, Mcl-1 and p53 was evaluated in miR-520c-3p transfected cells. Cell viability, colony formation, wound healing as well as apoptosis assays have been demonstrated. Furthermore, Mcl-1 protein level was measured using the western blot technique. RESULTS The present data indicated that miR-520c-3p overexpression could render HepG2 cells chemo-sensitive to DOX through enhancing its suppressive effects on proliferation, migration, and induction of apoptosis. The suppressive effect of miR-520c-3p involved altering the expression levels of some key regulators of cell cycle, proliferation, migration and apoptosis, including LEF1, CDK2, CDH1, VIM, Mcl-1 and p53. Interestingly, Mcl-1 was found to be one of the potential targets of miR-520c-3p, and its protein expression level was down-regulated upon miR-520c-3p overexpression. CONCLUSION Our data referred to the tumor suppressor function of miR-520c-3p that could modulate the chemosensitivity of HepG2 cells towards DOX treatment, providing a promising therapeutic strategy in HCC.
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Affiliation(s)
- Mohamed A Ragheb
- Department of Chemistry (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Marwa H Soliman
- Department of Chemistry (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Emad M Elzayat
- Department of Zoology, Faculty of Science, Cairo University, Giza, Egypt
| | - Mervat S Mohamed
- Department of Chemistry (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Nada El-Ekiaby
- School of Medicine, NewGiza University (NGU), NewGiza, Cairo, Egypt
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Eldeeb MA. N-Terminal-Dependent Protein Degradation and Targeting Cancer Cells. Anticancer Agents Med Chem 2021; 21:231-236. [PMID: 32814541 DOI: 10.2174/1871520620666200819112632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/11/2020] [Accepted: 04/19/2020] [Indexed: 11/22/2022]
Abstract
Intracellular protein degradation is mediated selectively by the Ubiquitin-Proteasome System (UPS) and autophagic-lysosomal system in mammalian cells. Many cellular and physiological processes, such as cell division, cell differentiation, and cellular demise, are fine-tuned via the UPS-mediated protein degradation. Notably, impairment of UPS contributes to human disorders, including cancer and neurodegeneration. The proteasome- dependent N-degron pathways mediate the degradation of proteins through their destabilizing aminoterminal residues. Recent advances unveiled that targeting N-degron proteolytic pathways can aid in sensitizing some cancer cells to chemotherapeutic agents. Furthermore, interestingly, exploiting the N-degron feature, the simplest degradation signal in mammals, and fusing it to a ligand specific for Estrogen-Related Receptor alpha (ERRa) has demonstrated its utility in ERRa knockdown, via N-terminal dependent degradation, and also its efficiency in the inhibition of growth of breast cancer cells. These recent advances uncover the therapeutic implications of targeting and exploiting N-degron proteolytic pathways to curb growth and migration of cancer cells.
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Affiliation(s)
- Mohamed A Eldeeb
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
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9
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Chen C, Qin H, Tang J, Hu Z, Tan J, Zeng L. USP30 protects against oxygen-glucose deprivation/reperfusion induced mitochondrial fragmentation and ubiquitination and degradation of MFN2. Aging (Albany NY) 2021; 13:6194-6204. [PMID: 33609088 PMCID: PMC7950302 DOI: 10.18632/aging.202629] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 01/21/2021] [Indexed: 12/06/2022]
Abstract
Cerebral ischemia-reperfusion induces mitochondrial fragmentation and dysfunction, which plays a critical role in the subsequent neuronal death and neurological impairment. Protection of mitochondria is an effective strategy to prevent neuronal damage after cerebral ischemia-reperfusion injury. USP30 is a deubiquitinating enzyme that localizes to the outer mitochondrial membrane. USP30 participates in the regulation of mitophagy and maintenance of mitochondrial morphology. In this study, the neuroprotective effect of USP30 and the underlying mechanisms were assessed in an ischemia-reperfusion injury model. SK-N-BE (2) cells were subjected to oxygen-glucose deprivation/reperfusion (OGDR) insult. Ubiquitination of mitochondrial proteins is increased during the early stage of reperfusion after oxygen-glucose deprivation (OGD), but the ubiquitination of cytoplasmic proteins exhibits no obvious changes. OGDR insult also induces rapid ubiquitination and degradation of the mitochondrial fusion protein mitofusin 2 (MFN2) in the early stage of reperfusion after OGD. Overexpression of MFN2 attenuates OGDR induced mitochondrial fragmentation. USP30 overexpression suppresses OGDR-induced ubiquitination and degradation of MFN2, and protects against mitochondrial fragmentation. Therefore, precisely targeting USP30 may provide a novel therapeutic strategy for cerebral ischemia-reperfusion related disorders.
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Affiliation(s)
- Chunli Chen
- Department of Neurology, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Haiyun Qin
- Department of Neurology, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Jiayu Tang
- Department of Neurology, The Second People's Hospital of Hunan Province, Changsha 410007, Hunan, China
| | - Zhiping Hu
- Department of Neurology, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
| | - Jieqiong Tan
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, Hunan, China.,Hunan Key Laboratory of Medical Genetics, Central South University, Changsha 410078, Hunan, China.,Hunan Key Laboratory of Animal Model for Human Diseases, Central South University, Changsha 410078, Hunan, China
| | - Liuwang Zeng
- Department of Neurology, Second Xiangya Hospital, Central South University, Changsha 410011, Hunan, China
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Eldeeb MA, Zorca CE, Ragheb MA, Rashidi FB, Salah El-Din DS. Fine-tuning ER-phagy by post-translational modifications. Bioessays 2020; 43:e2000212. [PMID: 33210303 DOI: 10.1002/bies.202000212] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 01/23/2023]
Abstract
Autophagy functions in both selective and non-selective ways to maintain cellular homeostasis. Endoplasmic reticulum autophagy (ER-phagy) is a subclass of autophagy responsible for the degradation of the endoplasmic reticulum through selective encapsulation into autophagosomes. ER-phagy occurs both under physiological conditions and in response to stress cues, and plays a crucial role in maintaining the homeostatic control of the organelle. Although specific receptors that target parts of the ER membrane, as well as, internal proteins for lysosomal degradation have been identified, the molecular regulation of ER-phagy has been elusive. Recent work has uncovered novel regulators of ER-phagy that involve post-translational modifications of ER-resident proteins and functional cross-talk with other cellular processes. Herein, we discuss how morphology affects the function of the peripheral ER, and how ER-phagy modulates the turnover of this organelle. We also address how ER-phagy is regulated at the molecular level, considering implications relevant to human diseases.
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Affiliation(s)
- Mohamed A Eldeeb
- McGill Parkinson Program, Neurodegenerative Diseases Group, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Cornelia E Zorca
- McGill Parkinson Program, Neurodegenerative Diseases Group, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Mohamed A Ragheb
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Fatma B Rashidi
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Doaa S Salah El-Din
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
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11
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N-degron-mediated degradation and regulation of mitochondrial PINK1 kinase. Curr Genet 2020; 66:693-701. [PMID: 32157382 DOI: 10.1007/s00294-020-01062-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 12/12/2022]
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative condition characterized by a gradual loss of a specific group of dopaminergic neurons in the substantia nigra. Importantly, current treatments only address the symptoms of PD, yet not the underlying molecular causes. Concomitantly, the function of genes that cause inherited forms of PD point to mitochondrial dysfunction as a major contributor in the etiology of PD. An inherent challenge that mitochondria face is the continuous exposure to diverse stresses including high levels of reactive oxygen species and protein misfolding, which increase their likelihood of dysregulation. In response, eukaryotic cells have evolved sophisticated quality control mechanisms to identify, repair and/or eliminate abnormal dysfunctional mitochondria. One such mechanism is mitophagy, a process which involves PTEN-induced putative kinase 1 (PINK1), a mitochondrial Ser/Thr kinase and Parkin, an E3 ubiquitin ligase, each encoded by genes responsible for early-onset autosomal recessive familial PD. Over 100 loss-of-function mutations in the PTEN-induced putative kinase 1 (PINK1) gene have been reported to cause autosomal recessive early-onset PD. PINK1 acts upstream of Parkin and is essential for the mitochondrial localization and activation of Parkin. Upon mitochondrial damage, PINK1 builds up on the outer mitochondrial membrane (OMM) and mediates the activation of Parkin. Activated Parkin then ubiquitinates numerous OMM proteins, eliciting mitochondrial autophagy (mitophagy). As a result, damaged mitochondrial components can be selectively eliminated. Thus, PINK1 acts a sensor of damage via fine-tuning of its levels on mitochondria, where it activates Parkin to orchestrate the clearance of unhealthy mitochondria. Previous work has unveiled that the Arg-N-end rule degradation pathway (Arg-N-degron pathway) mediates the degradation of PINK1, and thus fine-tune PINK1-dependent mitochondrial quality control pathway. Herein, we briefly discuss the interconnection between N-end rule degradation pathways and mitophagy in the context of N-degron mediated degradation of mitochondrial kinase PINK1 and highlight some of the future prospects.
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12
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Eldeeb MA, Ragheb MA, Esmaili M. How does protein degradation regulate TOM machinery-dependent mitochondrial import? Curr Genet 2020; 66:501-505. [PMID: 32060627 DOI: 10.1007/s00294-020-01056-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 01/19/2020] [Accepted: 01/21/2020] [Indexed: 12/13/2022]
Abstract
Mitochondrial dysregulation is a pivotal hallmark of aging-related disorders. Although there is a considerable understanding of the molecular counteracting responses toward damaged mitochondria, the molecular underpinnings connecting the abnormal aggregation of mitochondrial precursor protein fragments and abrogation of mitochondrial import machinery are far from clear. Recently, proteasomal-dependent degradation was unveiled as a pivotal fine-tuner of TOM machinery-dependent mitochondrial import. Herein, the role of proteasomal-mediated degradation in regulating fidelity of TOM-dependent import is briefly discussed and analyzed. The insights obtained from the characterization of this process may be applied to targeting mitochondrial import dysfunction in some neurodegenerative disorders.
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Affiliation(s)
- Mohamed A Eldeeb
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt. .,McGill Parkinson Program, Neurodegenerative Diseases Group, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| | - Mohamed A Ragheb
- Chemistry Department (Biochemistry Division), Faculty of Science, Cairo University, Giza, Egypt
| | - Mansoore Esmaili
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
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Mitochondrial dynamics and their potential as a therapeutic target. Mitochondrion 2019; 49:269-283. [PMID: 31228566 DOI: 10.1016/j.mito.2019.06.002] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/02/2019] [Accepted: 06/06/2019] [Indexed: 12/16/2022]
Abstract
Mitochondrial dynamics shape the mitochondrial network and contribute to mitochondrial function and quality control. Mitochondrial fusion and division are integrated into diverse cellular functions and respond to changes in cell physiology. Imbalanced mitochondrial dynamics are associated with a range of diseases that are broadly characterized by impaired mitochondrial function and increased cell death. In various disease models, modulating mitochondrial fusion and division with either small molecules or genetic approaches has improved function. Although additional mechanistic understanding of mitochondrial fusion and division will be critical to inform further therapeutic approaches, mitochondrial dynamics represent a powerful therapeutic target in a wide range of human diseases.
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The ubiquitin specific protease USP34 protects the ubiquitin ligase gp78 from proteasomal degradation. Biochem Biophys Res Commun 2019; 509:348-353. [DOI: 10.1016/j.bbrc.2018.12.141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 12/19/2018] [Indexed: 11/24/2022]
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Regulating Apoptosis by Degradation: The N-End Rule-Mediated Regulation of Apoptotic Proteolytic Fragments in Mammalian Cells. Int J Mol Sci 2018; 19:ijms19113414. [PMID: 30384441 PMCID: PMC6274719 DOI: 10.3390/ijms19113414] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 10/24/2018] [Accepted: 10/27/2018] [Indexed: 12/13/2022] Open
Abstract
A pivotal hallmark of some cancer cells is the evasion of apoptotic cell death. Importantly, the initiation of apoptosis often results in the activation of caspases, which, in turn, culminates in the generation of proteolytically-activated protein fragments with potentially new or altered roles. Recent investigations have revealed that the activity of a significant number of the protease-generated, activated, pro-apoptotic protein fragments can be curbed via their selective degradation by the N-end rule degradation pathways. Of note, previous work revealed that several proteolytically-generated, pro-apoptotic fragments are unstable in cells, as their destabilizing N-termini target them for proteasomal degradation via the N-end rule degradation pathways. Remarkably, previous studies also showed that the proteolytically-generated anti-apoptotic Lyn kinase protein fragment is targeted for degradation by the UBR1/UBR2 E3 ubiquitin ligases of the N-end rule pathway in chronic myeloid leukemia cells. Crucially, the degradation of cleaved fragment of Lyn by the N-end rule counters imatinib resistance in these cells, implicating a possible linkage between the N-end rule degradation pathway and imatinib resistance. Herein, we highlight recent studies on the role of the N-end rule proteolytic pathways in regulating apoptosis in mammalian cells, and also discuss some possible future directions with respect to apoptotic proteolysis signaling.
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The role of mitochondria in cellular toxicity as a potential drug target. Cell Biol Toxicol 2018; 34:87-91. [PMID: 29511917 DOI: 10.1007/s10565-018-9425-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 02/13/2018] [Indexed: 12/13/2022]
Abstract
Mitochondrial malfunction is related to aging and to the onset of many diseases, such as obesity/diabetes, cancer, and cardiovascular and neurodegenerative diseases. The molecular principles of biological and toxicological processes the mitochondria can regulate should be disease-specific, cell type-specific, and drug targetable. Mitochondrial biology and toxicology is evolving and undergoing a revolution through fast-developing biotechnologies garnering increasing attention due to the importance of targeted therapies. Mitochondrial energy production and metabolism are conducted via post-mitochondrial signaling, and are controlled by extra-mitochondrial pathways. Mitochondrial biology and toxicology has a history spanning over 30 years and is one of the main scientific focuses at Cell Biology and Toxicology. It is our aim to pioneer innovations of mitochondrial biology and toxicology to improve the understanding, highlight the latest development, and find mitochondria-based targets for therapies. It is expected to know how drugs can initiate mitochondrial dysfunction, the role of nuclear messages in regulating mitochondrial DNA (MtDNA), and how mitochondria communicate between or with other cells. Further studies are crucial to discover how mitochondria control the process of immune response, autophagy/mitophagy, genome activation, and cell interaction. It is also needed to innovate how the transcription is started and terminated within mitochondria, the cytosolic proteins and other organelles interact with mitochondria, and MtDNA regulates the function of mitochondrial respiratory megacomplexes.
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How Far Can Mitochondrial DNA Drive the Disease? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1038:1-8. [DOI: 10.1007/978-981-10-6674-0_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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