1
|
Mukherjee S, Das S, Bedi M, Vadupu L, Ball WB, Ghosh A. Methylglyoxal-mediated Gpd1 activation restores the mitochondrial defects in a yeast model of mitochondrial DNA depletion syndrome. Biochim Biophys Acta Gen Subj 2023; 1867:130328. [PMID: 36791826 DOI: 10.1016/j.bbagen.2023.130328] [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: 10/10/2022] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
Human MPV17, an evolutionarily conserved mitochondrial inner-membrane channel protein, accounts for the tissue-specific mitochondrial DNA depletion syndrome. However, the precise molecular function of the MPV17 protein is still elusive. Previous studies showed that the mitochondrial morphology and cristae organization are severely disrupted in the MPV17 knockout cells from yeast, zebrafish, and mammalian tissues. As mitochondrial cristae morphology is strictly regulated by the membrane phospholipids composition, we measured mitochondrial membrane phospholipids (PLs) levels in yeast Saccharomyces cerevisiae MPV17 ortholog, SYM1 (Stress-inducible Yeast MPV17) deleted cells. We found that Sym1 knockout decreases the mitochondrial membrane PL, phosphatidyl ethanolamine (PE), and inhibits respiratory growth at 37 ̊C on rich media. Both the oxygen consumption rate and the steady state expressions of mitochondrial complex II and super-complexes are compromised. Apart from mitochondrial PE defect a significant depletion of mitochondrial phosphatidyl-choline (PC) was noticed in the sym1∆ cells grown on synthetic media at both 30 ̊C and 37 ̊C temperatures. Surprisingly, exogenous supplementation of methylglyoxal (MG), an intrinsic side product of glycolysis, rescues the respiratory growth of Sym1 deficient yeast cells. Using a combination of molecular biology and lipid biochemistry, we uncovered that MG simultaneously restores both the mitochondrial PE/PC levels and the respiration by enhancing cytosolic NAD-dependent glycerol-3-phosphate dehydrogenase 1 (Gpd1) enzymatic activity. Further, MG is incapable to restore respiratory growth of the sym1∆gpd1∆ double knockout cells. Thus, our work provides Gpd1 activation as a novel strategy for combating Sym1 deficiency and PC/PE defects.
Collapse
Affiliation(s)
- Soumyajit Mukherjee
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata Pin-700019, India
| | - Shubhojit Das
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata Pin-700019, India
| | - Minakshi Bedi
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata Pin-700019, India
| | - Lavanya Vadupu
- Department of the Biological Sciences, SRM University- AP, Andhra Pradesh Pin- 522240, India
| | - Writoban Basu Ball
- Department of the Biological Sciences, SRM University- AP, Andhra Pradesh Pin- 522240, India
| | - Alok Ghosh
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata Pin-700019, India.
| |
Collapse
|
2
|
Wong HTC, Lukasz D, Drerup CM, Kindt KS. In vivo investigation of mitochondria in lateral line afferent neurons and hair cells. Hear Res 2023; 431:108740. [PMID: 36948126 PMCID: PMC10079644 DOI: 10.1016/j.heares.2023.108740] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 02/17/2023] [Accepted: 03/12/2023] [Indexed: 03/16/2023]
Abstract
To process sensory stimuli, intense energy demands are placed on hair cells and primary afferents. Hair cells must both mechanotransduce and maintain pools of synaptic vesicles for neurotransmission. Furthermore, both hair cells and afferent neurons must continually maintain a polarized membrane to propagate sensory information. These processes are energy demanding and therefore both cell types are critically reliant on mitochondrial health and function for their activity and maintenance. Based on these demands, it is not surprising that deficits in mitochondrial health can negatively impact the auditory and vestibular systems. In this review, we reflect on how mitochondrial function and dysfunction are implicated in hair cell-mediated sensory system biology. Specifically, we focus on live imaging approaches that have been applied to study mitochondria using the zebrafish lateral-line system. We highlight the fluorescent dyes and genetically encoded biosensors that have been used to study mitochondria in lateral-line hair cells and afferent neurons. We then describe the impact this in vivo work has had on the field of mitochondrial biology as well as the relationship between mitochondria and sensory system development, function, and survival. Finally, we delineate the areas in need of further exploration. This includes in vivo analyses of mitochondrial dynamics and biogenesis, which will round out our understanding of mitochondrial biology in this sensitive sensory system.
Collapse
Affiliation(s)
- Hiu-Tung C Wong
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Daria Lukasz
- Section on Sensory Cell Development and Function, National Institute of Deafness and other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Catherine M Drerup
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Katie S Kindt
- Section on Sensory Cell Development and Function, National Institute of Deafness and other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
3
|
Barrallo-Gimeno A, Llorens J. Hair cell toxicology: With the help of a little fish. Front Cell Dev Biol 2022; 10:1085225. [PMID: 36582469 PMCID: PMC9793777 DOI: 10.3389/fcell.2022.1085225] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022] Open
Abstract
Hearing or balance loss are disabling conditions that have a serious impact in those suffering them, especially when they appear in children. Their ultimate cause is frequently the loss of function of mechanosensory hair cells in the inner ear. Hair cells can be damaged by environmental insults, like noise or chemical agents, known as ototoxins. Two of the most common ototoxins are life-saving medications: cisplatin against solid tumors, and aminoglycoside antibiotics to treat infections. However, due to their localization inside the temporal bone, hair cells are difficult to study in mammals. As an alternative animal model, zebrafish larvae have hair cells similar to those in mammals, some of which are located in a fish specific organ on the surface of the skin, the lateral line. This makes them easy to observe in vivo and readily accessible for ototoxins or otoprotective substances. These features have made possible advances in the study of the mechanisms mediating ototoxicity or identifying new potential ototoxins. Most importantly, the small size of the zebrafish larvae has allowed screening thousands of molecules searching for otoprotective agents in a scale that would be highly impractical in rodent models. The positive hits found can then start the long road to reach clinical settings to prevent hearing or balance loss.
Collapse
Affiliation(s)
- Alejandro Barrallo-Gimeno
- Department de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Campus de Bellvitge, Universitat de Barcelona, L’Hospitalet de Llobregat, Spain,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain,Institut D'Investigació Biomèdica de Bellvitge, IDIBELL, L’Hospitalet de Llobregat, Spain,*Correspondence: Alejandro Barrallo-Gimeno,
| | - Jordi Llorens
- Department de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Campus de Bellvitge, Universitat de Barcelona, L’Hospitalet de Llobregat, Spain,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain,Institut D'Investigació Biomèdica de Bellvitge, IDIBELL, L’Hospitalet de Llobregat, Spain
| |
Collapse
|
4
|
Lee DS, Schrader A, Warchol M, Sheets L. Cisplatin exposure acutely disrupts mitochondrial bioenergetics in the zebrafish lateral-line organ. Hear Res 2022; 426:108513. [PMID: 35534350 PMCID: PMC9745743 DOI: 10.1016/j.heares.2022.108513] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/18/2022] [Accepted: 05/02/2022] [Indexed: 12/16/2022]
Abstract
Cisplatin is a commonly used chemotherapeutic agent that causes debilitating high-frequency hearing loss. No targeted therapies currently exist to treat cisplatin ototoxicity, partly because the underlying mechanisms of cisplatin-induced hair cell damage are not completely defined. Zebrafish may offer key insights to cisplatin ototoxicity because their lateral-line organ contains hair cells that are remarkably similar to those within the cochlea but are optically accessible, permitting observation of cisplatin injury in live intact hair cells. In this study, we used a combination of genetically encoded biosensors in zebrafish larvae and fluorescent indicators to characterize changes in mitochondrial bioenergetics in response to cisplatin. Following exposure to cisplatin, confocal imaging of live intact neuromasts demonstrated increased mitochondrial activity. Staining with fixable fluorescent dyes that accumulate in active mitochondria similarly showed hyperpolarized mitochondrial membrane potential. Zebrafish expressing a calcium indicator within their hair cells revealed elevated levels of mitochondrial calcium immediately following completion of cisplatin treatment. A fluorescent ROS indicator demonstrated that these changes in mitochondrial function were associated with increased oxidative stress. After a period of recovery, cisplatin-exposed zebrafish demonstrated caspase-3-mediated apoptosis. Altogether, these findings suggest that cisplatin acutely disrupts mitochondrial bioenergetics and may play a key role in initiating cisplatin ototoxicity.
Collapse
Affiliation(s)
- David S. Lee
- Department of Otolaryngology – Head and Neck Surgery, Washington University School of Medicine, 660 S. Euclid Ave. Campus Box 8115, St. Louis, MO 63110, USA,Corresponding author at: Department of Otolaryngology – Head and Neck Surgery, Washington University School of Medicine, 660 S. Euclid Ave. Campus Box 8115, St. Louis, MO 63110, USA. (D.S. Lee)
| | - Angela Schrader
- Department of Otolaryngology – Head and Neck Surgery, Washington University School of Medicine, 660 S. Euclid Ave. Campus Box 8115, St. Louis, MO 63110, USA
| | - Mark Warchol
- Department of Otolaryngology – Head and Neck Surgery, Washington University School of Medicine, 660 S. Euclid Ave. Campus Box 8115, St. Louis, MO 63110, USA,Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Lavinia Sheets
- Department of Otolaryngology – Head and Neck Surgery, Washington University School of Medicine, 660 S. Euclid Ave. Campus Box 8115, St. Louis, MO 63110, USA,Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
5
|
Saettele AL, Wong HTC, Kindt KS, Warchol ME, Sheets L. Prolonged Dexamethasone Exposure Enhances Zebrafish Lateral-Line Regeneration But Disrupts Mitochondrial Homeostasis and Hair Cell Function. J Assoc Res Otolaryngol 2022; 23:683-700. [PMID: 36261670 PMCID: PMC9789251 DOI: 10.1007/s10162-022-00875-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/20/2022] [Indexed: 01/06/2023] Open
Abstract
The synthetic glucocorticoid dexamethasone is commonly used to treat inner ear disorders. Previous work in larval zebrafish has shown that dexamethasone treatment enhances hair cell regeneration, yet dexamethasone has also been shown to inhibit regeneration of peripheral nerves after lesion. We therefore used the zebrafish model to determine the impact of dexamethasone treatment on lateral-line hair cells and primary afferents. To explore dexamethasone in the context of regeneration, we used copper sulfate (CuSO4) to induce hair cell loss and retraction of nerve terminals, and then allowed animals to recover in dexamethasone for 48 h. Consistent with previous work, we observed significantly more regenerated hair cells in dexamethasone-treated larvae. Importantly, we found that the afferent processes beneath neuromasts also regenerated in the presence of dexamethasone and formed an appropriate number of synapses, indicating that innervation of hair cells was not inhibited by dexamethasone. In addition to regeneration, we also explored the effects of prolonged dexamethasone exposure on lateral-line homeostasis and function. Following dexamethasone treatment, we observed hyperpolarized mitochondrial membrane potentials (ΔΨm) in neuromast hair cells and supporting cells. Hair cells exposed to dexamethasone were also more vulnerable to neomycin-induced cell death. In response to a fluid-jet delivered saturating stimulus, calcium influx through hair cell mechanotransduction channels was significantly reduced, yet presynaptic calcium influx was unchanged. Cumulatively, these observations indicate that dexamethasone enhances hair cell regeneration in lateral-line neuromasts, yet also disrupts mitochondrial homeostasis, making hair cells more vulnerable to ototoxic insults and possibly impacting hair cell function.
Collapse
Affiliation(s)
- Allison L Saettele
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, USA
| | - Hiu-Tung C Wong
- Section On Sensory Cell Development and Function, National Institutes On Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, USA
| | - Katie S Kindt
- Section On Sensory Cell Development and Function, National Institutes On Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, USA
| | - Mark E Warchol
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Lavinia Sheets
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
6
|
Evaluation of Cisplatin-Induced Pathology in the Larval Zebrafish Lateral Line. Int J Mol Sci 2022; 23:ijms232214302. [PMID: 36430778 PMCID: PMC9694025 DOI: 10.3390/ijms232214302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022] Open
Abstract
Cisplatin is an effective anticancer agent, but also causes permanent hearing loss by damaging hair cells-the sensory receptors essential for hearing. There is an urgent clinical need to protect cochlear hair cells in patients undergoing cisplatin chemotherapy. The zebrafish lateral line organ contains hair cells and has been frequently used in studies to screen for otoprotective compounds. However, these studies have employed a wide range of cisplatin dosages and exposure times. We therefore performed a comprehensive evaluation of cisplatin ototoxicity in the zebrafish lateral line with the goal of producing a standardized, clinically relevant protocol for future studies. To define the dose- and time-response patterns of cisplatin-induced hair-cell death, we treated 6-day-old larvae for 2 h in 50 µM-1 mM cisplatin and allowed them to recover. We observed delayed hair cell death, which peaked at 4-8 h post-exposure. Cisplatin also activated a robust inflammatory response, as determined by macrophage recruitment and phagocytosis of hair cells. However, selective depletion of macrophages did not affect hair cell loss. We also examined the effect of cisplatin treatment on fish behavior and found that cisplatin-induced lateral line injury measurably impaired rheotaxis. Finally, we examined the function of remaining hair cells that appeared resistant to cisplatin treatment. We observed significantly reduced uptake of the cationic dye FM1-43 in these cells relative to untreated controls, indicating that surviving hair cells may be functionally impaired. Cumulatively, these results indicate that relatively brief exposures to cisplatin can produce hair cell damage and delayed hair cell death. Our observations provide guidance on standardizing methods for the use of the zebrafish model in studies of cisplatin ototoxicity.
Collapse
|
7
|
Castranova D, Samasa B, Venero Galanternik M, Gore AV, Goldstein AE, Park JS, Weinstein BM. Long-term imaging of living adult zebrafish. Development 2022; 149:274463. [PMID: 35142351 PMCID: PMC8918778 DOI: 10.1242/dev.199667] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 11/30/2021] [Indexed: 11/20/2022]
Abstract
The zebrafish has become a widely used animal model due, in large part, to its accessibility to and usefulness for high-resolution optical imaging. Although zebrafish research has historically focused mostly on early development, in recent years the fish has increasingly been used to study regeneration, cancer metastasis, behavior and other processes taking place in juvenile and adult animals. However, imaging of live adult zebrafish is extremely challenging, with survival of adult fish limited to a few tens of minutes using standard imaging methods developed for zebrafish embryos and larvae. Here, we describe a new method for imaging intubated adult zebrafish using a specially designed 3D printed chamber for long-term imaging of adult zebrafish on inverted microscope systems. We demonstrate the utility of this new system by nearly day-long observation of neutrophil recruitment to a wound area in living double-transgenic adult casper zebrafish with fluorescently labeled neutrophils and lymphatic vessels, as well as intubating and imaging the same fish repeatedly. We also show that Mexican cavefish can be intubated and imaged in the same way, demonstrating this method can be used for long-term imaging of adult animals from diverse aquatic species.
Collapse
|
8
|
Holmgren M, Ravicz ME, Hancock KE, Strelkova O, Kallogjeri D, Indzhykulian AA, Warchol ME, Sheets L. Mechanical overstimulation causes acute injury and synapse loss followed by fast recovery in lateral-line neuromasts of larval zebrafish. eLife 2021; 10:69264. [PMID: 34665127 PMCID: PMC8555980 DOI: 10.7554/elife.69264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 10/18/2021] [Indexed: 12/14/2022] Open
Abstract
Excess noise damages sensory hair cells, resulting in loss of synaptic connections with auditory nerves and, in some cases, hair-cell death. The cellular mechanisms underlying mechanically induced hair-cell damage and subsequent repair are not completely understood. Hair cells in neuromasts of larval zebrafish are structurally and functionally comparable to mammalian hair cells but undergo robust regeneration following ototoxic damage. We therefore developed a model for mechanically induced hair-cell damage in this highly tractable system. Free swimming larvae exposed to strong water wave stimulus for 2 hr displayed mechanical injury to neuromasts, including afferent neurite retraction, damaged hair bundles, and reduced mechanotransduction. Synapse loss was observed in apparently intact exposed neuromasts, and this loss was exacerbated by inhibiting glutamate uptake. Mechanical damage also elicited an inflammatory response and macrophage recruitment. Remarkably, neuromast hair-cell morphology and mechanotransduction recovered within hours following exposure, suggesting severely damaged neuromasts undergo repair. Our results indicate functional changes and synapse loss in mechanically damaged lateral-line neuromasts that share key features of damage observed in noise-exposed mammalian ear. Yet, unlike the mammalian ear, mechanical damage to neuromasts is rapidly reversible.
Collapse
Affiliation(s)
- Melanie Holmgren
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States
| | - Michael E Ravicz
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Kenneth E Hancock
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Olga Strelkova
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Dorina Kallogjeri
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States
| | - Artur A Indzhykulian
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Mark E Warchol
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States.,Department of Neuroscience, Washington University School of Medicine, St Louis, United States
| | - Lavinia Sheets
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States.,Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States
| |
Collapse
|