1
|
Liu C, Tang J, Chen Y, Zhang Q, Lin J, Wu S, Han J, Liu Z, Wu C, Zhuo Y, Li Y. Intracellular Zn 2+ promotes extracellular matrix remodeling in dexamethasone-treated trabecular meshwork. Am J Physiol Cell Physiol 2024; 326:C1293-C1307. [PMID: 38525543 DOI: 10.1152/ajpcell.00725.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/26/2024] [Accepted: 03/09/2024] [Indexed: 03/26/2024]
Abstract
Given the widespread application of glucocorticoids in ophthalmology, the associated elevation of intraocular pressure (IOP) has long been a vexing concern for clinicians, yet the underlying mechanisms remain inconclusive. Much of the discussion focuses on the extracellular matrix (ECM) of trabecular meshwork (TM). It is widely agreed that glucocorticoids impact the expression of matrix metalloproteinases (MMPs), leading to ECM deposition. Since Zn2+ is vital for MMPs, we explored its role in ECM alterations induced by dexamethasone (DEX). Our study revealed that in human TM cells treated with DEX, the level of intracellular Zn2+ significantly decreased, accompanied by impaired extracellular Zn2+ uptake. This correlated with changes in several Zrt-, Irt-related proteins (ZIPs) and metallothionein. ZIP8 knockdown impaired extracellular Zn2+ uptake, but Zn2+ chelation did not affect ZIP8 expression. Resembling DEX's effects, chelation of Zn2+ decreased MMP2 expression, increased the deposition of ECM proteins, and induced structural disarray of ECM. Conversely, supplementation of exogenous Zn2+ in DEX-treated cells ameliorated these outcomes. Notably, dietary zinc supplementation in mice significantly reduced DEX-induced IOP elevation and collagen content in TM, thereby rescuing the visual function of the mice. These findings underscore zinc's pivotal role in ECM regulation, providing a novel perspective on the pathogenesis of glaucoma.NEW & NOTEWORTHY Our study explores zinc's pivotal role in mitigating extracellular matrix dysregulation in the trabecular meshwork and glucocorticoid-induced ocular hypertension. We found that in human trabecular meshwork cells treated with dexamethasone, intracellular Zn2+ significantly decreased, accompanied by impaired extracellular Zn2+ uptake. Zinc supplementation rescues visual function by modulating extracellular matrix proteins and lowering intraocular pressure, offering a direction for further exploration in glaucoma management.
Collapse
Affiliation(s)
- Canying Liu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Jiahui Tang
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Yuze Chen
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Qi Zhang
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Jicheng Lin
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Siting Wu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Jiaxu Han
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Zhe Liu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Caiqing Wu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Yehong Zhuo
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Yiqing Li
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| |
Collapse
|
2
|
Pang JJ. The Variety of Mechanosensitive Ion Channels in Retinal Neurons. Int J Mol Sci 2024; 25:4877. [PMID: 38732096 PMCID: PMC11084373 DOI: 10.3390/ijms25094877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/16/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
Alterations in intraocular and external pressure critically involve the pathogenesis of glaucoma, traumatic retinal injury (TRI), and other retinal disorders, and retinal neurons have been reported to express multiple mechanical-sensitive channels (MSCs) in recent decades. However, the role of MSCs in visual functions and pressure-related retinal conditions has been unclear. This review will focus on the variety and functional significance of the MSCs permeable to K+, Na+, and Ca2+, primarily including the big potassium channel (BK); the two-pore domain potassium channels TRAAK and TREK; Piezo; the epithelial sodium channel (ENaC); and the transient receptor potential channels vanilloid TRPV1, TRPV2, and TRPV4 in retinal photoreceptors, bipolar cells, horizontal cells, amacrine cells, and ganglion cells. Most MSCs do not directly mediate visual signals in vertebrate retinas. On the other hand, some studies have shown that MSCs can open in physiological conditions and regulate the activities of retinal neurons. While these data reasonably predict the crossing of visual and mechanical signals, how retinal light pathways deal with endogenous and exogenous mechanical stimulation is uncertain.
Collapse
Affiliation(s)
- Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA
| |
Collapse
|
3
|
Guo H, Chen LQ, Zou ZR, Cheng S, Hu Y, Mao L, Tian H, Mei XF. Zinc remodels mitochondrial network through SIRT3/Mfn2-dependent mitochondrial transfer in ameliorating spinal cord injury. Eur J Pharmacol 2024; 968:176368. [PMID: 38316246 DOI: 10.1016/j.ejphar.2024.176368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/08/2024] [Accepted: 01/29/2024] [Indexed: 02/07/2024]
Abstract
Spinal cord injury (SCI) is a traumatic neuropathic condition that results in motor, sensory and autonomic dysfunction. Mitochondrial dysfunction caused by primary trauma is one of the critical pathogenic mechanisms. Moderate levels of zinc have antioxidant effects, promote neurogenesis and immune responses. Zinc normalises mitochondrial morphology in neurons after SCI. However, how zinc protects mitochondria within neurons is unknown. In the study, we used transwell culture, Western blot, Quantitative Real-time Polymerase Chain Reaction (QRT-PCR), ATP content detection, reactive oxygen species (ROS) activity assay, flow cytometry and immunostaining to investigate the relationship between zinc-treated microglia and injured neurons through animal and cell experiments. We found that zinc promotes mitochondrial transfer from microglia to neurons after SCI through Sirtuin 3 (SIRT3) regulation of Mitofusin 2 protein (Mfn2). It can rescue mitochondria in damaged neurons and inhibit oxidative stress, increase ATP levels and promote neuronal survival. Therefore, it can improve the recovery of motor function in SCI mice. In conclusion, our work reveals a potential mechanism to describe the communication between microglia and neurons after SCI, which may provide a new idea for future therapeutic approaches to SCI.
Collapse
Affiliation(s)
- Hui Guo
- School of Basic Medicine, Jinzhou Medical University, Jinzhou, Liaoning, China; Liaoning Provincial Collaborative Innovation Center of Medical Testing and Drug Research, Jinzhou Medical University, Jinzhou, Liaoning, China.
| | - Li-Qing Chen
- Department of Endocrinology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning, China.
| | - Zhi-Ru Zou
- Pharmacy School, Jinzhou Medical University, Jinzhou, Liaoning, China.
| | - Shuai Cheng
- School of Basic Medicine, Jinzhou Medical University, Jinzhou, Liaoning, China; Liaoning Provincial Collaborative Innovation Center of Medical Testing and Drug Research, Jinzhou Medical University, Jinzhou, Liaoning, China.
| | - Yu Hu
- School of Basic Medicine, Jinzhou Medical University, Jinzhou, Liaoning, China.
| | - Liang Mao
- Department of Oncology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning, China.
| | - He Tian
- School of Basic Medicine, Jinzhou Medical University, Jinzhou, Liaoning, China; Liaoning Provincial Collaborative Innovation Center of Medical Testing and Drug Research, Jinzhou Medical University, Jinzhou, Liaoning, China.
| | - Xi-Fan Mei
- Liaoning Provincial Collaborative Innovation Center of Medical Testing and Drug Research, Jinzhou Medical University, Jinzhou, Liaoning, China.
| |
Collapse
|
4
|
Wu C, Han J, Wu S, Liu C, Zhang Q, Tang J, Liu Z, Yang J, Chen Y, Zhuo Y, Li Y. Reduced Zn 2+ promotes retinal ganglion cells survival and optic nerve regeneration after injury through inhibiting autophagy mediated by ROS/Nrf2. Free Radic Biol Med 2024; 212:415-432. [PMID: 38134974 DOI: 10.1016/j.freeradbiomed.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023]
Abstract
The molecular mechanism of how reduced mobile zinc (Zn2+) affected retinal ganglion cell (RGC) survival and optic nerve regeneration after optic nerve crush (ONC) injury remains unclear. Here, we used conditionally knocked out ZnT-3 in the amacrine cells (ACs) of mice (CKO) in order to explore the role of reactive oxygen species (ROS), nuclear factor erythroid 2-related factor 2 (NFE2L2, Nrf2) and autophagy in the protection of RGCs and axon regeneration after ONC injury. We found that reduced Zn2+ can promote RGC survival and axonal regeneration by decreasing ROS, activating Nrf2, and inhibiting autophagy. Additionally, autophagy after ONC is regulated by ROS and Nrf2. Visual function in mice after ONC injury was partially recovered through the reduction of Zn2+, achieved by using a Zn2+ specific chelator N,N,N',N'-tetrakis-(2-Pyridylmethyl) ethylenediamine (TPEN) or through CKO mice. Overall, our data reveal the crosstalk between Zn2+, ROS, Nrf2 and autophagy following ONC injury. This study verified that TPEN or knocking out ZnT-3 in ACs is a promising therapeutic option for the treatment of optic nerve damage and elucidated the postsynaptic molecular mechanism of Zn2+-triggered damage to RGCs after ONC injury.
Collapse
Affiliation(s)
- Caiqing Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Jiaxu Han
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Siting Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Canying Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Qi Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Jiahui Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Zhe Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Jinpeng Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Yuze Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Yehong Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China.
| | - Yiqing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China.
| |
Collapse
|
5
|
Yao BF, Luo XJ, Peng J. A review for the correlation between optic atrophy 1-dependent mitochondrial fusion and cardiovascular disorders. Int J Biol Macromol 2024; 254:127910. [PMID: 37939779 DOI: 10.1016/j.ijbiomac.2023.127910] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 10/19/2023] [Accepted: 11/03/2023] [Indexed: 11/10/2023]
Abstract
Mitochondrial dynamics homeostasis is sustained by continuous and balanced fission and fusion, which are determinants of morphology, abundance, biogenesis and mitophagy of mitochondria. Optic atrophy 1 (OPA1), as the only inner mitochondrial membrane fusion protein, plays a key role in stabilizing mitochondrial dynamics. The disturbance of mitochondrial dynamics contributes to the pathophysiological progress of cardiovascular disorders, which are the main cause of death worldwide in recent decades and result in tremendous social burden. In this review, we describe the latest findings regarding OPA1 and its role in mitochondrial fusion. We summarize the post-translational modifications (PTMs) for OPA1 and its regulatory role in mitochondrial dynamics. Then the diverse cell fates caused by OPA1 expression during cardiovascular disorders are discussed. Moreover, cardiovascular disorders (such as heart failure, myocardial ischemia/reperfusion injury, cardiomyopathy and cardiac hypertrophy) relevant to OPA1-dependent mitochondrial dynamics imbalance have been detailed. Finally, we highlight the potential that targeting OPA1 to impact mitochondrial fusion may be used as a novel strategy against cardiovascular disorders.
Collapse
Affiliation(s)
- Bi-Feng Yao
- Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410078, China
| | - Xiu-Ju Luo
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha 410013, China
| | - Jun Peng
- Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410078, China; Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410078, China.
| |
Collapse
|
6
|
Wu S, Liu C, Tang J, Wu C, Zhang Q, Liu Z, Han J, Xue J, Lin J, Chen Y, Yang J, Zhuo Y, Li Y. Tafluprost promotes axon regeneration after optic nerve crush via Zn 2+-mTOR pathway. Neuropharmacology 2024; 242:109746. [PMID: 37832634 DOI: 10.1016/j.neuropharm.2023.109746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/23/2023] [Accepted: 10/04/2023] [Indexed: 10/15/2023]
Abstract
PURPOSE To investigate whether Tafluprost could promote optic nerve regeneration in mice after optic nerve crush (ONC) and determine the underlying molecular mechanism. METHODS Tafluprost was injected into the vitreous body immediately after ONC. The level of Zn2+ in the inner plexiform layer (IPL) of the retina was stained using autometallography (AMG). The number of survival retinal ganglion cells (RGCs) was determined via dual staining with RGC markers Tuj1 and RBPMS. Individual axons that regenerated to 0.25, 0.5, 0.75 and 1 mm were manually counted in the whole-mount optic nerve labeled by cholera toxin B fragment (CTB). Immunofluorescence and Western blot were performed to detect protein expression levels. Pattern electroretinogram was used to evaluate RGCs function. RESULTS Tafluprost promoted RGC survival in a dose-dependent manner with an optimal concentration of 1 μM. Tafluprost significantly decreased ZnT-3 expression and Zn2+ accumulation in the IPL of retina. Tafluprost stimulated intense axonal regeneration and maintained RGCs function compared to control. Mechanistically, Tafluprost and Zn2+ elimination treatment (TPEN or ZnT-3 deletion) can activate the mTOR pathway with an improved percentage of pS6+ RGCs in the retina. However, rapamycin, a specific inhibitor of the mTOR1, inhibited the activation of the mTOR pathway and abolished the regenerative effect mediated by Tafluprost. Tafluprost also inhibited the upregulation of p62, LC3 and Beclin-1, attenuated the overactivation of microglia/macrophages and downregulated the expression of TNFα and IL-1β. CONCLUSIONS Our results suggest that Tafluprost promoted axon regeneration via regulation of the Zn2+-mTOR pathway, and provide novel research directions for glaucomatous optic nerve injury mechanisms.
Collapse
Affiliation(s)
- Siting Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Canying Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Jiahui Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Caiqing Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Qi Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Zhe Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Jiaxu Han
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Jingfei Xue
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Jicheng Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Yuze Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Jinpeng Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China
| | - Yehong Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China.
| | - Yiqing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, 510060, China.
| |
Collapse
|
7
|
Yang Q, Wang L, Liang Y, He Q, Sun Q, Luo J, Cao H, Fang Y, Zhou Y, Yang J, Wen P, Jiang L. Loss of UCP2 causes mitochondrial fragmentation by OMA1-dependent proteolytic processing of OPA1 in podocytes. FASEB J 2023; 37:e23265. [PMID: 37874273 DOI: 10.1096/fj.202301055r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/26/2023] [Accepted: 10/10/2023] [Indexed: 10/25/2023]
Abstract
Mitochondrial dysfunction plays an important role in the onset and progression of podocyte injury and proteinuria. However, the process by which the change in the podocyte mitochondria occurs is not well understood. Uncoupling protein 2 (UCP2) is a mitochondrial anion carrier protein, which is located in the mitochondrial inner membrane. Here, we reported that mice with podocyte-specific Ucp2 deficiency developed podocytopathy with proteinuria with aging. Furthermore, those mice exhibited increased proteinuria in experimental models evoked by Adriamycin. Our findings suggest that UCP2 mediates mitochondrial dysfunction by regulating mitochondrial dynamic balance. Ucp2-deleted podocytes exhibited increased mitochondrial fission and deficient in ATP production. Mechanistically, opacity protein 1 (OPA1), a key protein in fusion of mitochondrial inner membrane, was regulated by UCP2. Ucp2 deficiency promoted proteolysis of OPA1 by activation OMA1 which belongs to mitochondrial inner membrane zinc metalloprotease. Those finding demonstrate the role of UCP2 in mitochondrial dynamics in podocytes and provide new insights into pathogenesis associated with podocyte injury and proteinuria.
Collapse
Affiliation(s)
- Qianqian Yang
- Division of Nephrology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, China
| | - Lulu Wang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yuehong Liang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qingyu He
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qi Sun
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jing Luo
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hongdi Cao
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yi Fang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yang Zhou
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Junwei Yang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ping Wen
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Lei Jiang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| |
Collapse
|
8
|
Chapa-Dubocq XR, Rodríguez-Graciani KM, García-Báez J, Vadovsky A, Bazil JN, Javadov S. The Role of Swelling in the Regulation of OPA1-Mediated Mitochondrial Function in the Heart In Vitro. Cells 2023; 12:2017. [PMID: 37626827 PMCID: PMC10453793 DOI: 10.3390/cells12162017] [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: 06/18/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
Optic atrophy-1 (OPA1) plays a crucial role in the regulation of mitochondria fusion and participates in maintaining the structural integrity of mitochondrial cristae. Here we elucidate the role of OPA1 cleavage induced by calcium swelling in the presence of Myls22 (an OPA1 GTPase activity inhibitor) and TPEN (an OMA1 inhibitor). The rate of ADP-stimulated respiration was found diminished by both inhibitors, and they did not prevent Ca2+-induced mitochondrial respiratory dysfunction, membrane depolarization, or swelling. L-OPA1 cleavage was stimulated at state 3 respiration; therefore, our data suggest that L-OPA1 cleavage produces S-OPA1 to maintain mitochondrial bioenergetics in response to stress.
Collapse
Affiliation(s)
- Xavier R. Chapa-Dubocq
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR 00936-5067, USA; (X.R.C.-D.); (K.M.R.-G.); (J.G.-B.)
| | - Keishla M. Rodríguez-Graciani
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR 00936-5067, USA; (X.R.C.-D.); (K.M.R.-G.); (J.G.-B.)
| | - Jorge García-Báez
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR 00936-5067, USA; (X.R.C.-D.); (K.M.R.-G.); (J.G.-B.)
| | - Alyssa Vadovsky
- Department of Physiology, Michigan State University, East Lansing, MI 48824-1046, USA; (A.V.); (J.N.B.)
| | - Jason N. Bazil
- Department of Physiology, Michigan State University, East Lansing, MI 48824-1046, USA; (A.V.); (J.N.B.)
| | - Sabzali Javadov
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR 00936-5067, USA; (X.R.C.-D.); (K.M.R.-G.); (J.G.-B.)
| |
Collapse
|
9
|
Chapa-Dubocq XR, Rodríguez-Graciani KM, Escobales N, Javadov S. Mitochondrial Volume Regulation and Swelling Mechanisms in Cardiomyocytes. Antioxidants (Basel) 2023; 12:1517. [PMID: 37627512 PMCID: PMC10451443 DOI: 10.3390/antiox12081517] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/24/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
Mitochondrion, known as the "powerhouse" of the cell, regulates ion homeostasis, redox state, cell proliferation and differentiation, and lipid synthesis. The inner mitochondrial membrane (IMM) controls mitochondrial metabolism and function. It possesses high levels of proteins that account for ~70% of the membrane mass and are involved in the electron transport chain, oxidative phosphorylation, energy transfer, and ion transport, among others. The mitochondrial matrix volume plays a crucial role in IMM remodeling. Several ion transport mechanisms, particularly K+ and Ca2+, regulate matrix volume. Small increases in matrix volume through IMM alterations can activate mitochondrial respiration, whereas excessive swelling can impair the IMM topology and initiates mitochondria-mediated cell death. The opening of mitochondrial permeability transition pores, the well-characterized phenomenon with unknown molecular identity, in low- and high-conductance modes are involved in physiological and pathological increases of matrix volume. Despite extensive studies, the precise mechanisms underlying changes in matrix volume and IMM structural remodeling in response to energy and oxidative stressors remain unknown. This review summarizes and discusses previous studies on the mechanisms involved in regulating mitochondrial matrix volume, IMM remodeling, and the crosstalk between these processes.
Collapse
Affiliation(s)
| | | | | | - Sabzali Javadov
- Department of Physiology, University of Puerto Rico School of Medicine, San Juan, PR 00936-5067, USA; (X.R.C.-D.); (K.M.R.-G.); (N.E.)
| |
Collapse
|