1
|
LeVine SM. Examining the Role of a Functional Deficiency of Iron in Lysosomal Storage Disorders with Translational Relevance to Alzheimer's Disease. Cells 2023; 12:2641. [PMID: 37998376 PMCID: PMC10670892 DOI: 10.3390/cells12222641] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/09/2023] [Accepted: 11/13/2023] [Indexed: 11/25/2023] Open
Abstract
The recently presented Azalea Hypothesis for Alzheimer's disease asserts that iron becomes sequestered, leading to a functional iron deficiency that contributes to neurodegeneration. Iron sequestration can occur by iron being bound to protein aggregates, such as amyloid β and tau, iron-rich structures not undergoing recycling (e.g., due to disrupted ferritinophagy and impaired mitophagy), and diminished delivery of iron from the lysosome to the cytosol. Reduced iron availability for biochemical reactions causes cells to respond to acquire additional iron, resulting in an elevation in the total iron level within affected brain regions. As the amount of unavailable iron increases, the level of available iron decreases until eventually it is unable to meet cellular demands, which leads to a functional iron deficiency. Normally, the lysosome plays an integral role in cellular iron homeostasis by facilitating both the delivery of iron to the cytosol (e.g., after endocytosis of the iron-transferrin-transferrin receptor complex) and the cellular recycling of iron. During a lysosomal storage disorder, an enzyme deficiency causes undigested substrates to accumulate, causing a sequelae of pathogenic events that may include cellular iron dyshomeostasis. Thus, a functional deficiency of iron may be a pathogenic mechanism occurring within several lysosomal storage diseases and Alzheimer's disease.
Collapse
Affiliation(s)
- Steven M LeVine
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| |
Collapse
|
2
|
Clement D, Szabo EK, Krokeide SZ, Wiiger MT, Vincenti M, Palacios D, Chang YT, Grimm C, Patel S, Stenmark H, Brech A, Majhi RK, Malmberg KJ. The Lysosomal Calcium Channel TRPML1 Maintains Mitochondrial Fitness in NK Cells through Interorganelle Cross-Talk. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:1348-1358. [PMID: 37737664 PMCID: PMC10579149 DOI: 10.4049/jimmunol.2300406] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/18/2023] [Indexed: 09/23/2023]
Abstract
Cytotoxic lymphocytes eliminate cancer cells through the release of lytic granules, a specialized form of secretory lysosomes. This compartment is part of the pleomorphic endolysosomal system and is distinguished by its highly dynamic Ca2+ signaling machinery. Several transient receptor potential (TRP) calcium channels play essential roles in endolysosomal Ca2+ signaling and ensure the proper function of these organelles. In this study, we examined the role of TRPML1 (TRP cation channel, mucolipin subfamily, member 1) in regulating the homeostasis of secretory lysosomes and their cross-talk with mitochondria in human NK cells. We found that genetic deletion of TRPML1, which localizes to lysosomes in NK cells, led to mitochondrial fragmentation with evidence of collapsed mitochondrial cristae. Consequently, TRPML1-/- NK92 (NK92ML1-/-) displayed loss of mitochondrial membrane potential, increased reactive oxygen species stress, reduced ATP production, and compromised respiratory capacity. Using sensitive organelle-specific probes, we observed that mitochondria in NK92ML1-/- cells exhibited evidence of Ca2+ overload. Moreover, pharmacological activation of the TRPML1 channel in primary NK cells resulted in upregulation of LC3-II, whereas genetic deletion impeded autophagic flux and increased accumulation of dysfunctional mitochondria. Thus, TRPML1 impacts autophagy and clearance of damaged mitochondria. Taken together, these results suggest that an intimate interorganelle communication in NK cells is orchestrated by the lysosomal Ca2+ channel TRPML1.
Collapse
Affiliation(s)
- Dennis Clement
- Precision Immunotherapy Alliance, Institute for Cancer Research, University of Oslo, Norway
- Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Edina K. Szabo
- Precision Immunotherapy Alliance, Institute for Cancer Research, University of Oslo, Norway
| | | | - Merete Thune Wiiger
- Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Marianna Vincenti
- Precision Immunotherapy Alliance, Institute for Cancer Research, University of Oslo, Norway
- Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Daniel Palacios
- Precision Immunotherapy Alliance, Institute for Cancer Research, University of Oslo, Norway
- Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Young-Tae Chang
- Department of Chemistry, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Christian Grimm
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Munich, Munich, Germany
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Harald Stenmark
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo, Norway
| | - Andreas Brech
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo, Norway
| | - Rakesh Kumar Majhi
- Precision Immunotherapy Alliance, Institute for Cancer Research, University of Oslo, Norway
- Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Tissue Restoration Lab, Department of Biological Sciences and Bioengineering, Mehta Family Center of Engineering and Medicine, Indian Institute of Technology Kanpur, Kanpur, India
| | - Karl-Johan Malmberg
- Precision Immunotherapy Alliance, Institute for Cancer Research, University of Oslo, Norway
- Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institute, Stockholm, Sweden
| |
Collapse
|
3
|
Yassin-Kassab A, Wang N, Foley J, Stewart TM, Burns MR, Casero RA, Harbison RA, Duvvuri U. Polyamine transport inhibition and cisplatin synergistically enhance tumor control through oxidative stress in murine head and neck cancer models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.25.550524. [PMID: 37546993 PMCID: PMC10402081 DOI: 10.1101/2023.07.25.550524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Background Surgery and/or platinum-based chemoradiation remain standard of care for patients with head and neck squamous cell carcinoma (HNSCC). While these therapies are effective in a subset of patients, a substantial proportion experience recurrence or treatment resistance. As cisplatin mediates cytotoxicity through oxidative stress while polyamines play a role in redox regulation, we posited that combining cisplatin with polyamine transport inhibitor, AMXT-1501, would increase oxidative stress and tumor cell death in HNSCC cells. Methods Cell proliferation was measured in syngeneic mouse HNSCC cell lines treated with cisplatin ± AMXT-1501. Synergy was determined by administering cisplatin and AMXT-1501 at a ratio of 1:10 to cancer cells in vitro . Cancer cells were transferred onto mouse flanks to test the efficacy of treatments in vivo . Reactive oxygen species (ROS) were measured. Cellular apoptosis was measured with flow cytometry using Annexin V/PI staining. High-performance liquid chromatography (HPLC) was used to quantify polyamines in cell lines. Cell viability and ROS were measured in the presence of exogenous cationic amino acids. Results The combination of cisplatin and AMXT-1501 synergize in vitro on HNSCC cell lines. In vivo combination treatment resulted in tumor growth inhibition greater than either treatment individually. The combination treatment increased ROS production and induced apoptotic cell death. HPLC revealed the synergistic mechanism was independent of intracellular polyamine levels. Supplementation of cationic amino acids partially rescued cancer cell viability and reduced ROS. Conclusion AMXT-1501 enhances the cytotoxic effects of cisplatin in vitro and in vivo in aggressive HNSCC cell lines through a polyamine-independent mechanism.
Collapse
|
4
|
Križaj D, Cordeiro S, Strauß O. Retinal TRP channels: Cell-type-specific regulators of retinal homeostasis and multimodal integration. Prog Retin Eye Res 2023; 92:101114. [PMID: 36163161 PMCID: PMC9897210 DOI: 10.1016/j.preteyeres.2022.101114] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 02/05/2023]
Abstract
Transient receptor potential (TRP) channels are a widely expressed family of 28 evolutionarily conserved cationic ion channels that operate as primary detectors of chemical and physical stimuli and secondary effectors of metabotropic and ionotropic receptors. In vertebrates, the channels are grouped into six related families: TRPC, TRPV, TRPM, TRPA, TRPML, and TRPP. As sensory transducers, TRP channels are ubiquitously expressed across the body and the CNS, mediating critical functions in mechanosensation, nociception, chemosensing, thermosensing, and phototransduction. This article surveys current knowledge about the expression and function of the TRP family in vertebrate retinas, which, while dedicated to transduction and transmission of visual information, are highly susceptible to non-visual stimuli. Every retinal cell expresses multiple TRP subunits, with recent evidence establishing their critical roles in paradigmatic aspects of vertebrate vision that include TRPM1-dependent transduction of ON bipolar signaling, TRPC6/7-mediated ganglion cell phototransduction, TRP/TRPL phototransduction in Drosophila and TRPV4-dependent osmoregulation, mechanotransduction, and regulation of inner and outer blood-retina barriers. TRP channels tune light-dependent and independent functions of retinal circuits by modulating the intracellular concentration of the 2nd messenger calcium, with emerging evidence implicating specific subunits in the pathogenesis of debilitating diseases such as glaucoma, ocular trauma, diabetic retinopathy, and ischemia. Elucidation of TRP channel involvement in retinal biology will yield rewards in terms of fundamental understanding of vertebrate vision and therapeutic targeting to treat diseases caused by channel dysfunction or over-activation.
Collapse
Affiliation(s)
- David Križaj
- Departments of Ophthalmology, Neurobiology, and Bioengineering, University of Utah, Salt Lake City, USA
| | - Soenke Cordeiro
- Institute of Physiology, Faculty of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Olaf Strauß
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany.
| |
Collapse
|
5
|
Rani L, Ranjan Sahu M, Chandra Mondal A. Age-related Mitochondrial Dysfunction in Parkinson's Disease: New Insights Into the Disease Pathology. Neuroscience 2022; 499:152-169. [PMID: 35839924 DOI: 10.1016/j.neuroscience.2022.07.007] [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: 04/05/2022] [Revised: 06/13/2022] [Accepted: 07/07/2022] [Indexed: 12/14/2022]
Abstract
Aging is a progressive loss of physiological function that increases risk of disease and death. Among the many factors that contribute to human aging, mitochondrial dysfunction has emerged as one of the most prominent features of the aging process. It has been linked to the development of various age-related pathologies, including Parkinson's disease (PD). Mitochondria has a complex quality control system that ensures mitochondrial integrity and function. Perturbations in these mitochondrial mechanisms have long been linked to various age-related neurological disorders. Even though research has shed light on several aspects of the disease pathology, the underlying mechanism of age-related factors responsible for individuals developing this disease is still unknown. This review article aims to discuss the role of mitochondria in the transition from normal brain aging to pathological brain aging, which leads to the progression of PD. We have discussed the emerging evidence on how age-related disruption of mitochondrial quality control mechanisms contributes to the development of PD-related pathophysiology.
Collapse
Affiliation(s)
- Linchi Rani
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India
| | - Manas Ranjan Sahu
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India
| | - Amal Chandra Mondal
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India.
| |
Collapse
|
6
|
Abstract
Cisplatin is the first line therapy for patients with head and neck cancer. However, resistance to cisplatin remains a major concern. High expression of the calcium-activated chloride channel TMEM16A in tumors portends poor survival in these patients, possibly because of drug resistance. Here, we show that TMEM16A drives the sequestration of cisplatin into lysosomes. Subsequently, cisplatin is expelled via the delivery of lysosomes to the cell surface. We show that TMEM16A enhances this process, thereby promoting cisplatin resistance. We also show that lysosomal inhibition synergizes with cisplatin to induce tumor cell death. Our data uncovers a new fundamental feature of both lysosomal physiology and cancer cell biology that can potentially impact the treatment of patients with head and neck cancer. Squamous cell carcinoma of the head and neck (SCCHN) is a devastating disease that continues to have low cure rates despite the recent advances in therapies. Cisplatin is the most used chemotherapy agent, and treatment failure is largely driven by resistance to this drug. Amplification of chromosomal band 11q13 occurs in ∼30% of SCCHN tumors. This region harbors the ANO1 gene that encodes the TMEM16A ion channel, which is responsible for calcium-activated chloride transport in epithelial tissues. TMEM16A overexpression is associated with cisplatin resistance, and high TMEM16A levels correlate with decreased survival. However, the mechanistic underpinning of this effect remains unknown. Lysosomal biogenesis and exocytosis have been implicated in cancer because of their roles in the clearance of damaged organelles and exocytosis of chemotherapeutic drugs and toxins. Here, we show that TMEM16A overexpression promotes lysosomal biogenesis and exocytosis, which is consistent with the expulsion of intracellular cisplatin. Using a combination of genetic and pharmacologic approaches, we find that TMEM16A promotes lysosomal flux in a manner that requires reactive oxygen species, TRPML1, and the activation of the β-catenin–melanocyte-inducing transcription factor pathway. The lysosomal inhibitor hydroxychloroquine (HCQ) synergizes with cisplatin in killing SCCHN cells in vitro. Using a murine model of SCCHN, we show that HCQ and cisplatin retard the growth of cisplatin-resistant patient-derived xenografts in vivo. We propose that TMEM16A enables cell survival by the up-regulation of lysosomal sequestration and exocytosis of the cytotoxic drugs. These results uncover a model of treatment for resistance in cancer, its reversal, and a role for TMEM16A.
Collapse
|
7
|
Hafez AA, Jamali Z, Samiei S, Khezri S, Salimi A. Reduction of doxorubicin-induced cytotoxicity and mitochondrial damage by betanin in rat isolated cardiomyocytes and mitochondria. Hum Exp Toxicol 2021; 40:2123-2134. [PMID: 34105389 DOI: 10.1177/09603271211022800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Doxorubicin (DOX) is an anticancer drug which is used for treatment of several types of cancers. But the clinical use of doxorubicin is limited because of its cardiotoxicity and cardiomyopathy. Mitochondrial-dependent oxidative stress and cardiac inflammation appear to be involved in doxorubicin-induced cardiotoxicity. Betanin as a bioactive compound in Beetroot (Beta vulgaris L.) displays anti-radical, antioxidant gene regulatory and cardioprotective activities. In this current study, we investigated the protective effect of betanin on doxorubicin-induced cytotoxicity and mitochondrial-dependent oxidative stress in isolated cardiomyocytes and mitochondria. Isolated cardiomyocytes and mitochondria were treated with three concentrations of betanin (1, 5 and 10 µM) and doxorubicin (3.5 µM) for 6 h. The parameters of cellular and mitochondrial toxicity were analyzed using biochemical and flow cytometric methods. Our results showed a significant toxicity in isolated cardiomyocytes and mitochondria in presence of doxorubicin which was related to reactive oxygen species (ROS) formation, increase in malondialdehyde (MDA), increase in oxidation of GSH to GSSG, lysosomal/mitochondrial damages and mitochondrial swelling. While betanin pretreatment reverted doxorubicin-induced cytotoxicity and oxidative stress in isolated cardiomyocytes and mitochondria. These results suggest that betanin elicited a typical protective effect on doxorubicin-induced cytotoxicity and oxidative stress. It is possible that betanin could be used as a useful adjuvant in combination with doxorubicin chemotherapy for reduction of cardiotoxicity and cardiomyopathy.
Collapse
Affiliation(s)
- A A Hafez
- Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Z Jamali
- Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran
- Department of Addiction Studies, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran
| | - S Samiei
- School of Medicine, Kordestan University of Medical Sciences, Sanandaj, Iran
| | - S Khezri
- Traditional Medicine and Hydrotherapy Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
- Department of Pharmacology and Toxicology, School of Pharmacy, Ardabil University of Medical Sciences, Ardabil, Iran
| | - A Salimi
- Traditional Medicine and Hydrotherapy Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
- Department of Pharmacology and Toxicology, School of Pharmacy, Ardabil University of Medical Sciences, Ardabil, Iran
| |
Collapse
|
8
|
Misko A, Wood L, Kiselyov K, Slaugenhaupt S, Grishchuk Y. Progress in elucidating pathophysiology of mucolipidosis IV. Neurosci Lett 2021; 755:135944. [PMID: 33965501 PMCID: PMC8253105 DOI: 10.1016/j.neulet.2021.135944] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 11/19/2022]
Abstract
Mucolipidosis IV (MLIV) is an autosomal-recessive disease caused by loss-of-function mutations in the MCOLN1 gene encoding the non-selective cationic lysosomal channel transient receptor potential mucolipin-1 (TRPML1). Patients with MLIV suffer from severe motor and cognitive deficits that manifest in early infancy and progressive loss of vision leading to blindness in the second decade of life. There are no therapies available for MLIV and the unmet medical need is extremely high. Here we review the spectrum of clinical presentations and the latest research in the MLIV pre-clinical model, with the aim of highlighting the progress in understanding the pathophysiology of the disease. These highlights include elucidation of the neurodevelopmental versus neurodegenerative features over the course of disease, hypomyelination as one of the major brain pathological disease hallmarks, and dysregulation of cytokines, with emerging evidence of IFN-gamma pathway upregulation in response to TRPML1 loss and pro-inflammatory activation of astrocytes and microglia. These scientific advances in the MLIV field provide a basis for future translational research, including biomarker and therapy development, that are desperately needed for this patient population.
Collapse
Affiliation(s)
- Albert Misko
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, 02114, United States
| | - Levi Wood
- Georgia W. Woodruff School of Mechanical Engineering, Wallace H. Coulter Department of Biomedical Engineering, and Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, United States
| | - Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, United States
| | - Susan Slaugenhaupt
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, 02114, United States
| | - Yulia Grishchuk
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA, 02114, United States.
| |
Collapse
|
9
|
Abstract
Lysosomal calcium is emerging as a modulator of autophagy and lysosomal compartment, an obligatory partner to complete the autophagic pathway. A variety of specific signals such as nutrient deprivation or oxidative stress can trigger lysosomal calcium-mediated nuclear translocation of the transcription factor EB (TFEB), a master regulator of global lysosomal function. Also, lysosomal calcium can promote the formation of autophagosome vesicles (AVs) by a mechanism that requires the production of the phosphoinositide PI3P by the VPS34 autophagic complex and the activation of the energy-sensing kinase AMPK. Additionally, lysosomal calcium plays a role in membrane fusion and fission events involved in cellular processes such as endocytic maturation, autophagosome-lysosome fusion, lysosomal exocytosis, and lysosomal reformation upon autophagy completion. Lysosomal calcium-dependent functions are defective in cellular and animal models of the non-selective cation channel TRPML1, whose mutations in humans cause the neurodegenerative lysosomal storage disease mucolipidosis type IV (MLIV). Lysosomal calcium is not only acting as a positive regulator of autophagy, but it is also responsible for turning-off this process through the reactivation of the mTOR kinase during prolonged starvation. More recently, it has been described the role of lysosomal calcium on an elegant sequence of intracellular signaling events such as membrane repair, lysophagy, and lysosomal biogenesis upon the induction of different grades of lysosomal membrane damage. Here, we will discuss these novel findings that re-define the importance of the lysosome and lysosomal calcium signaling at regulating cellular metabolism.
Collapse
|
10
|
Santoni G, Amantini C, Nabissi M, Maggi F, Arcella A, Marinelli O, Eleuteri AM, Santoni M, Morelli MB. Knock-Down of Mucolipin 1 Channel Promotes Tumor Progression and Invasion in Human Glioblastoma Cell Lines. Front Oncol 2021; 11:578928. [PMID: 33954107 PMCID: PMC8092188 DOI: 10.3389/fonc.2021.578928] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 02/12/2021] [Indexed: 12/21/2022] Open
Abstract
Among cancers that affect the central nervous system, glioblastoma is the most common. Given the negative prognostic significance of transient receptor potential mucolipin 1 (TRPML1) channel reduction in patients with glioblastoma, as discussed in previous publications, the aim of the current study was to investigate the biological advantage of TRPML1 loss for glioma cells. Human glioblastoma primary cancer cells (FSL and FCL) and glioblastoma cell lines (T98 and U251) were used for that purpose. TRPML1 silencing in T98 cells induces defective autophagy, nitric oxide (NO) production, and cathepsin B-dependent apoptosis in the first 48 h and then apoptotic-resistant cells proliferate with a high growth rate with respect to control cells. In U251 cells, knock-down of TRPML1 stimulates NO generation and protein oxidation, arrests cell cycle at G2/M phase, and induces autophagy leading to cathepsin B-dependent senescence. Finally, in both cell lines, the long-term effects of TRPML1 silencing promote survival and invasion capacity with respect to control cells. Silencing of TRPML1 also affects the phenotype of glioblastoma primary cells. FSL cells show increased proliferation ability, while FCL cells enter into senescence associated with an increased invasion ability. In conclusion, although the molecular heterogeneity among different glioblastoma cell lines mirrors the intercellular heterogeneity in cancer cells, our data support TRPML1 downregulation as a negative prognostic factor in glioblastoma.
Collapse
Affiliation(s)
- Giorgio Santoni
- Immunopathology Laboratory, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Consuelo Amantini
- Immunopathology Laboratory, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Massimo Nabissi
- Immunopathology Laboratory, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Federica Maggi
- Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Antonietta Arcella
- Neuropathology Laboratory, Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli, Italy
| | - Oliviero Marinelli
- Immunopathology Laboratory, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Anna Maria Eleuteri
- Clinical Biochemistry Laboratory, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Matteo Santoni
- Medical Oncology Unit, Hospital of Macerata, Macerata, Italy
| | | |
Collapse
|
11
|
Ferroptosis and Its Modulation by Autophagy in Light of the Pathogenesis of Lysosomal Storage Diseases. Cells 2021; 10:cells10020365. [PMID: 33578654 PMCID: PMC7916399 DOI: 10.3390/cells10020365] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/31/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022] Open
Abstract
Ferroptosis is one of the recently described types of cell death which is dependent on many factors, including the accumulation of iron and lipid peroxidation. Its induction requires various signaling pathways. Recent discovery of ferroptosis induction pathways stimulated by autophagy, so called autophagy-dependent ferroptosis, put our attention on the role of ferroptosis in lysosomal storage diseases (LSD). Lysosome dysfunction, observed in these diseases, may influence ferroptosis efficiency, with as yet unknown consequences for the function of cells, tissues, and organisms, due to the effects of ferroptosis on physiological and pathological metabolic processes. Modulation of levels of ferrous ions and enhanced oxidative stress, which are primary markers of ferroptosis, are often described as processes associated with the pathology of LSD. Inhibition of autophagy flux and resultant accumulation of autophagosomes in neuronopathic LSD may induce autophagy-dependent ferroptosis, indicating a considerable contribution of this process in neurodegeneration. In this review article, we describe molecular mechanisms of ferroptosis in light of LSD, underlining the modulation of levels of ferroptosis markers in these diseases. Furthermore, we propose a hypothesis about the possible involvement of autophagy-dependent ferroptosis in these disorders.
Collapse
|
12
|
Hoogmartens C, Rickmann A, Bocqué C, Szurman P, Boden KT. [Late onset visual loss due to retinal atrophy in atypical mucolipidosis type IV]. Ophthalmologe 2021; 119:90-92. [PMID: 33502543 DOI: 10.1007/s00347-021-01322-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 01/08/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Caroline Hoogmartens
- Augenklinik Sulzbach, Knappschaftsklinikum Saar, An der Klinik 10, 66280, Sulzbach/Saar, Deutschland.
| | - Annekatrin Rickmann
- Augenklinik Sulzbach, Knappschaftsklinikum Saar, An der Klinik 10, 66280, Sulzbach/Saar, Deutschland
| | - Catheline Bocqué
- Augenklinik Sulzbach, Knappschaftsklinikum Saar, An der Klinik 10, 66280, Sulzbach/Saar, Deutschland
| | - Peter Szurman
- Augenklinik Sulzbach, Knappschaftsklinikum Saar, An der Klinik 10, 66280, Sulzbach/Saar, Deutschland
| | - Karl Thomas Boden
- Augenklinik Sulzbach, Knappschaftsklinikum Saar, An der Klinik 10, 66280, Sulzbach/Saar, Deutschland
| |
Collapse
|
13
|
Ray B, Bhat A, Mahalakshmi AM, Tuladhar S, Bishir M, Mohan SK, Veeraraghavan VP, Chandra R, Essa MM, Chidambaram SB, Sakharkar MK. Mitochondrial and Organellar Crosstalk in Parkinson's Disease. ASN Neuro 2021; 13:17590914211028364. [PMID: 34304614 PMCID: PMC8317254 DOI: 10.1177/17590914211028364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/04/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial dysfunction is a well-established pathological event in Parkinson's disease (PD). Proteins misfolding and its impaired cellular clearance due to altered autophagy/mitophagy/pexophagy contribute to PD progression. It has been shown that mitochondria have contact sites with endoplasmic reticulum (ER), peroxisomes and lysosomes that are involved in regulating various physiological processes. In pathological conditions, the crosstalk at the contact sites initiates alterations in intracellular vesicular transport, calcium homeostasis and causes activation of proteases, protein misfolding and impairment of autophagy. Apart from the well-reported molecular changes like mitochondrial dysfunction, impaired autophagy/mitophagy and oxidative stress in PD, here we have summarized the recent scientific reports to provide the mechanistic insights on the altered communications between ER, peroxisomes, and lysosomes at mitochondrial contact sites. Furthermore, the manuscript elaborates on the contributions of mitochondrial contact sites and organelles dysfunction to the pathogenesis of PD and suggests potential therapeutic targets.
Collapse
Affiliation(s)
- Bipul Ray
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysuru, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, Mysuru, India
| | - Abid Bhat
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysuru, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, Mysuru, India
| | | | - Sunanda Tuladhar
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysuru, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, Mysuru, India
| | - Muhammed Bishir
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysuru, India
| | - Surapaneni Krishna Mohan
- Department of Biochemistry, Panimalar Medical College Hospital & Research Institute, Varadharajapuram, Poonamallee, Chennai – 600123, India
| | - Vishnu Priya Veeraraghavan
- Department of Biochemistry, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai - 600 077, India
| | - Ramesh Chandra
- Drug Discovery & Development Laboratory, Department of Chemistry, University of Delhi, Delhi, 110007, India
- Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
| | - Musthafa Mohamed Essa
- Department of Food Science and Nutrition, CAMS, Sultan Qaboos University, Muscat, Oman
- Aging and Dementia Research Group, Sultan Qaboos University, Muscat, Sultanate of Oman
- Visiting Professor, Biomedical Sciences department, University of Pacific, Sacramento, CA, USA
| | - Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysuru, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, Mysuru, India
| | - Meena Kishore Sakharkar
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK- S7N 5A2, Canada
| |
Collapse
|
14
|
Li G, Li PL. Lysosomal TRPML1 Channel: Implications in Cardiovascular and Kidney Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:275-301. [PMID: 35138619 PMCID: PMC9899368 DOI: 10.1007/978-981-16-4254-8_13] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lysosomal ion channels mediate ion flux from lysosomes and regulate membrane potential across the lysosomal membrane, which are essential for lysosome biogenesis, nutrient sensing, lysosome trafficking, lysosome enzyme activity, and cell membrane repair. As a cation channel, the transient receptor potential mucolipin 1 (TRPML1) channel is mainly expressed on lysosomes and late endosomes. Recently, the normal function of TRPML1 channels has been demonstrated to be important for the maintenance of cardiovascular and renal glomerular homeostasis and thereby involved in the pathogenesis of some cardiovascular and kidney diseases. In arterial myocytes, it has been found that Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP), an intracellular second messenger, can induce Ca2+ release through the lysosomal TRPML1 channel, leading to a global Ca2+ release response from the sarcoplasmic reticulum (SR). In podocytes, it has been demonstrated that lysosomal TRPML1 channels control lysosome trafficking and exosome release, which contribute to the maintenance of podocyte functional integrity. The defect or functional deficiency of lysosomal TRPML1 channels has been shown to critically contribute to the initiation and development of some chronic degeneration or diseases in the cardiovascular system or kidneys. Here we briefly summarize the current evidence demonstrating the regulation of lysosomal TRPML1 channel activity and related signaling mechanisms. We also provide some insights into the canonical and noncanonical roles of TRPML1 channel dysfunction as a potential pathogenic mechanism for certain cardiovascular and kidney diseases and associated therapeutic strategies.
Collapse
Affiliation(s)
- Guangbi Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA.
| |
Collapse
|
15
|
Yan Y, Wang Y, Ding J, Lu L, Ke GJ, Dong K. TRPML1 Inhibited Photoreceptor Apoptosis and Protected the Retina by Activation of Autophagy in Experimental Retinal Detachment. Ophthalmic Res 2020; 64:587-594. [PMID: 33027790 DOI: 10.1159/000512104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 09/23/2020] [Indexed: 11/19/2022]
Abstract
OBJECTIVE In this study, we used a rat model of retinal detachment (RD) to investigate the effects of transient receptor potential mucolipin 1 (TRPML1) on photoreceptor cells and the underlying mechanism. METHODS An RD model was established by subretinal injection of sodium hyaluronate, and mucolipin synthetic agonist 1 (ML-SA1) and dimethyl sulphoxide were subretinally injected after RD induction. Retinal morphology was observed using haematoxylin-eosin staining, and the apoptosis of photoreceptor cells was detected by transmission electron microscopy. Reactive oxygen species (ROS) were examined with an ROS detection kit. The retinal expression levels of TRPML1, the autophagy-related protein microtubule-associated protein 1 light chain 3 (LC3), Beclin 1, and cleaved caspase 3 were detected by Western blotting. The Morris water maze was used to test vision-dependent behaviour. RESULTS We found that retinal structure and the outer nuclear layer were improved and that the apoptosis of photoreceptor cells was reduced after ML-SA1 injection. The expression of ROS was reduced, and the loss of TRPML1 was inhibited after ML-SA1 treatment. The LC3-II to LC3-I ratio and Beclin 1 expression were enhanced, and cleaved caspase 3 expression was decreased after ML-SA1 treatment. Treatment with ML-SA1 also improved vision-dependent behaviour. CONCLUSIONS Our findings suggest that ML-SA1 attenuates photoreceptor apoptosis and improves vision-dependent behaviour by activation of autophagy.
Collapse
Affiliation(s)
- Yuanye Yan
- Department of Ophthalmology, Eye Center, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yisai Wang
- Department of Ophthalmology, Anhui Medical University, Hefei, China
| | - Jie Ding
- Department of Ophthalmology, The Second People's Hospital of Hefei, Hefei, China
| | - Li Lu
- Department of Ophthalmology, Eye Center, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Gen-Jie Ke
- Department of Ophthalmology, Eye Center, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.,Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Kai Dong
- Department of Ophthalmology, Eye Center, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| |
Collapse
|
16
|
Mepyans M, Andrzejczuk L, Sosa J, Smith S, Herron S, DeRosa S, Slaugenhaupt SA, Misko A, Grishchuk Y, Kiselyov K. Early evidence of delayed oligodendrocyte maturation in the mouse model of mucolipidosis type IV. Dis Model Mech 2020; 13:dmm044230. [PMID: 32586947 PMCID: PMC7406328 DOI: 10.1242/dmm.044230] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 06/16/2020] [Indexed: 12/19/2022] Open
Abstract
Mucolipidosis type IV (MLIV) is a lysosomal disease caused by mutations in the MCOLN1 gene that encodes the endolysosomal transient receptor potential channel mucolipin-1, or TRPML1. MLIV results in developmental delay, motor and cognitive impairments, and vision loss. Brain abnormalities include thinning and malformation of the corpus callosum, white-matter abnormalities, accumulation of undegraded intracellular 'storage' material and cerebellar atrophy in older patients. Identification of the early events in the MLIV course is key to understanding the disease and deploying therapies. The Mcoln1-/- mouse model reproduces all major aspects of the human disease. We have previously reported hypomyelination in the MLIV mouse brain. Here, we investigated the onset of hypomyelination and compared oligodendrocyte maturation between the cortex/forebrain and cerebellum. We found significant delays in expression of mature oligodendrocyte markers Mag, Mbp and Mobp in the Mcoln1-/- cortex, manifesting as early as 10 days after birth and persisting later in life. Such delays were less pronounced in the cerebellum. Despite our previous finding of diminished accumulation of the ferritin-bound iron in the Mcoln1-/- brain, we report no significant changes in expression of the cytosolic iron reporters, suggesting that iron-handling deficits in MLIV occur in the lysosomes and do not involve broad iron deficiency. These data demonstrate very early deficits of oligodendrocyte maturation and critical regional differences in myelination between the forebrain and cerebellum in the mouse model of MLIV. Furthermore, they establish quantitative readouts of the MLIV impact on early brain development, useful to gauge efficacy in pre-clinical trials.
Collapse
Affiliation(s)
- Molly Mepyans
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Livia Andrzejczuk
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jahree Sosa
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Sierra Smith
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Shawn Herron
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Samantha DeRosa
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Susan A Slaugenhaupt
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Albert Misko
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Yulia Grishchuk
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| |
Collapse
|
17
|
Copper-dependent ATP7B up-regulation drives the resistance of TMEM16A-overexpressing head-and-neck cancer models to platinum toxicity. Biochem J 2020; 476:3705-3719. [PMID: 31790150 DOI: 10.1042/bcj20190591] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/13/2019] [Accepted: 12/02/2019] [Indexed: 12/17/2022]
Abstract
Platinum-containing drugs such as cisplatin and carboplatin are routinely used for the treatment of many solid tumors including squamous cell carcinoma of the head and neck (SCCHN). However, SCCHN resistance to platinum compounds is well documented. The resistance to platinum has been linked to the activity of divalent transporter ATP7B, which pumps platinum from the cytoplasm into lysosomes, decreasing its concentration in the cytoplasm. Several cancer models show increased expression of ATP7B; however, the reason for such an increase is not known. Here we show a strong positive correlation between mRNA levels of TMEM16A and ATP7B in human SCCHN tumors. TMEM16A overexpression and depletion in SCCHN cell lines caused parallel changes in the ATP7B mRNA levels. The ATP7B increase in TMEM16A-overexpressing cells was reversed by suppression of NADPH oxidase 2 (NOX2), by the antioxidant N-Acetyl-Cysteine (NAC) and by copper chelation using cuprizone and bathocuproine sulphonate (BCS). Pretreatment with either chelator significantly increased cisplatin's sensitivity, particularly in the context of TMEM16A overexpression. We propose that increased oxidative stress in TMEM16A-overexpressing cells liberates the chelated copper in the cytoplasm, leading to the transcriptional activation of ATP7B expression. This, in turn, decreases the efficacy of platinum compounds by promoting their vesicular sequestration. We think that such a new explanation of the mechanism of SCCHN tumors' platinum resistance identifies novel approach to treating these tumors.
Collapse
|
18
|
Jezela-Stanek A, Ciara E, Stepien KM. Neuropathophysiology, Genetic Profile, and Clinical Manifestation of Mucolipidosis IV-A Review and Case Series. Int J Mol Sci 2020; 21:ijms21124564. [PMID: 32604955 PMCID: PMC7348969 DOI: 10.3390/ijms21124564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/21/2020] [Accepted: 06/23/2020] [Indexed: 12/23/2022] Open
Abstract
Mucolipidosis type IV (MLIV) is an ultra-rare lysosomal storage disorder caused by biallelic mutations in MCOLN1 gene encoding the transient receptor potential channel mucolipin-1. So far, 35 pathogenic or likely pathogenic MLIV-related variants have been described. Clinical manifestations include severe intellectual disability, speech deficit, progressive visual impairment leading to blindness, and myopathy. The severity of the condition may vary, including less severe psychomotor delay and/or ocular findings. As no striking recognizable facial dysmorphism, skeletal anomalies, organomegaly, or lysosomal enzyme abnormalities in serum are common features of MLIV, the clinical diagnosis may be significantly improved because of characteristic ophthalmological anomalies. This review aims to outline the pathophysiology and genetic defects of this condition with a focus on the genotype–phenotype correlation amongst cases published in the literature. The authors will present their own clinical observations and long-term outcomes in adult MLIV cases.
Collapse
Affiliation(s)
- Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland;
| | - Elżbieta Ciara
- Department of Medical Genetics, The Children’s Memorial Heath Institute, 04-730 Warsaw, Poland;
| | - Karolina M. Stepien
- Adult Inherited Metabolic Diseases, Salford Royal NHS Foundation Trust, Salford M6 8HD, UK
- Correspondence:
| |
Collapse
|
19
|
Googins MR, Woghiren-Afegbua AO, Calderon M, St Croix CM, Kiselyov KI, VanDemark AP. Structural and functional divergence of GDAP1 from the glutathione S-transferase superfamily. FASEB J 2020; 34:7192-7207. [PMID: 32274853 DOI: 10.1096/fj.202000110r] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/12/2020] [Accepted: 03/24/2020] [Indexed: 11/11/2022]
Abstract
Mutations in ganglioside-induced differentiation-associated protein 1 (GDAP1) alter mitochondrial morphology and result in several subtypes of the inherited peripheral neuropathy Charcot-Marie-Tooth disease; however, the mechanism by which GDAP1 functions has remained elusive. GDAP1 contains primary sequence homology to the GST superfamily; however, the question of whether GDAP1 is an active GST has not been clearly resolved. Here, we present biochemical evidence, suggesting that GDAP1 has lost the ability to bind glutathione without a loss of substrate binding activity. We have revealed that the α-loop, located within the H-site motif is the primary determinant for substrate binding. Using structural data of GDAP1, we have found that critical residues and configurations in the G-site which canonically interact with glutathione are altered in GDAP1, rendering it incapable of binding glutathione. Last, we have found that the overexpression of GDAP1 in HeLa cells results in a mitochondrial phenotype which is distinct from oxidative stress-induced mitochondrial fragmentation. This phenotype is dependent on the presence of the transmembrane domain, as well as a unique hydrophobic domain that is not found in canonical GSTs. Together, we data point toward a non-enzymatic role for GDAP1, such as a sensor or receptor.
Collapse
Affiliation(s)
- Matthew R Googins
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Michael Calderon
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Kirill I Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Andrew P VanDemark
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
20
|
Cheng Z, Yang B, Zhou H, Nunez Y, Kranzler HR, Gelernter J. Genome-wide scan identifies opioid overdose risk locus close to MCOLN1. Addict Biol 2020; 25:e12811. [PMID: 31362332 DOI: 10.1111/adb.12811] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 06/13/2019] [Accepted: 06/26/2019] [Indexed: 01/22/2023]
Abstract
The United States is experiencing the worst opioid overdose (OpOD) crisis in its history. We carried out a genome-wide association study on OpOD severity among 3 477 opioid-exposed individuals, 1 019 of whom experienced OpODs, including 2 032 European Americans (EAs) (653 overdose cases), and 1 445 African Americans (AAs) (366 overdose cases). Participants were scored 1 to 4 based on their reported overdose status and the number of times that medical treatment was required. Genome-wide association study (GWAS) of EAs and AAs separately resulted in two genome-wide significant (GWS) signals in AAs but none in EAs. The first signal was represented by three closely mapped variants (rs115208233, rs116181528, and rs114077267) located near mucolipin 1 (MCOLN1) and patatin-like phospholipase domain containing 6 (PNPLA6), and the other signal was represented by rs369098800 near dead-box helicase 18 (DDX18). There were no additional GWS signals in the trans-population meta-analysis, so that post-GWAS analysis focused on these loci. In network analysis, MCOLN1 was coexpressed with PNPLA6, but only MCOLN1-associated genes were enriched in functional categories relevant to OpOD, including calcium and cation channel activities; no enrichment was observed for PNPLA6-associated genes. Drug repositioning analysis was carried out in the connectivity map (CMap) database for MCOLN1 (PNPLA6 was not available in CMap) and showed that the opioid agonist drug-induced expression profile is similar to that of MCOLN1 overexpression and yielded the highest-ranked expression profile of 83 drug classes. Thus, MCOLN1 may be a risk gene for OpOD, but replication is needed. This knowledge could be helpful in the identification of drug targets for preventing OpOD.
Collapse
Affiliation(s)
- Zhongshan Cheng
- Division of Human Genetics, Department of PsychiatryYale University School of Medicine and VA CT Healthcare Center New Haven CT USA
| | - Bao‐Zhu Yang
- Division of Human Genetics, Department of PsychiatryYale University School of Medicine and VA CT Healthcare Center New Haven CT USA
| | - Hang Zhou
- Division of Human Genetics, Department of PsychiatryYale University School of Medicine and VA CT Healthcare Center New Haven CT USA
| | - Yaira Nunez
- Division of Human Genetics, Department of PsychiatryYale University School of Medicine and VA CT Healthcare Center New Haven CT USA
| | - Henry R. Kranzler
- Center for Studies of Addiction, Department of PsychiatryUniversity of Pennsylvania Perelman School of Medicine and Crescenz Veterans Affairs Medical Center Philadelphia PA USA
| | - Joel Gelernter
- Division of Human Genetics, Department of PsychiatryYale University School of Medicine and VA CT Healthcare Center New Haven CT USA
- Departments of Genetics and NeuroscienceYale University School of Medicine New Haven CT USA
| |
Collapse
|
21
|
Spix B, Chao YK, Abrahamian C, Chen CC, Grimm C. TRPML Cation Channels in Inflammation and Immunity. Front Immunol 2020; 11:225. [PMID: 32184778 PMCID: PMC7058977 DOI: 10.3389/fimmu.2020.00225] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 01/28/2020] [Indexed: 12/24/2022] Open
Abstract
Background: In 1883, Ilya Mechnikov discovered phagocytes and established the concept of phagocytosis by macrophages. In 1908, he was awarded the Nobel Prize in Physiology/Medicine for his findings, which laid the foundations for today's understanding of the innate immune response. Only in the 1960s, Max Cooper and Robert Good significantly advanced our understanding of the immune system by demonstrating that B- and T-cells cooperate to regulate the adaptive immune response. Both, innate and adaptive immune response are essential to effectively protect the individual against infectious agents, such as viruses, bacterial or insect toxins, or allergens. Innate immune responses occur rapidly upon exposure to noxious or infectious agents or organisms, in contrast to the adaptive immune system that needs days rather than hours to develop and acts primarily on the basis of antigen-specific receptors expressed on the surface of B- and T-lymphocytes. In recent years, it has become evident that endosomes and lysosomes are involved in many aspects of immune cell function, such as phagocytosis, antigen presentation and processing by antigen-presenting cells, release of proinflammatory mediators, e.g., by mast cells, or secretion of the pore-forming protein perforin by cytotoxic T lymphocytes. Several lysosomal storage disorders (LSDs) have been associated with defects in immune system function or immune system hyperactivity, such as Gaucher, Fabry, or Niemann-Pick type C1 disease, mucopolysaccharidoses (MPS), gangliosidosis, or juvenile neuronal ceroid lipofuscinosis (JNCL). Beside accumulating evidence on the importance of endolysosomes in immune cell function, recent results suggest direct roles of endolysosomal ion channels, such as the TRPML channels (mucolipins), which are members of the transient receptor potential (TRP) superfamily of non-selective cation channels, for different aspects of immune cell function. The aim of this review is to discuss the current knowledge about the roles of TRPML channels in inflammation and immunity, and to assess their potential as drug targets to influence immune cell functions. Advances: Examples of recently established roles of TRPML channels in immune system function and immune response include the TRPML1-mediated modulation of secretory lysosomes, granzyme B content, and tuning of effector function in NK cells, TRPML1-dependent directional dendritic cell (DC) migration and DC chemotaxis, and the role of TRPML2 in chemokine release from LPS-stimulated macrophages. Outlook: Although our understanding of the functional roles of TRPML channels in inflammation and immunity is still in its infancy, a few interesting findings have been made in the past years, encouraging further and more detailed work on the role of TRPMLs, e.g., in intracellular trafficking and release of chemokines, cytokines, or granzyme B, or in phagocytosis and bacterial toxin and virus trafficking through the endolysosomal machinery.
Collapse
Affiliation(s)
- Barbara Spix
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Yu-Kai Chao
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Carla Abrahamian
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Cheng-Chang Chen
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Christian Grimm
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany
| |
Collapse
|
22
|
Al-Bari MAA, Xu P. Molecular regulation of autophagy machinery by mTOR-dependent and -independent pathways. Ann N Y Acad Sci 2020; 1467:3-20. [PMID: 31985829 DOI: 10.1111/nyas.14305] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 11/23/2019] [Accepted: 01/07/2020] [Indexed: 12/15/2022]
Abstract
Macroautophagy is a lysosomal degradative pathway or recycling process that maintains cellular homeostasis. This autophagy involves a series of sequential processing events, such as initiation; elongation and nucleation of the isolation membrane; cargo recruitment and maturation of the autophagosome (AP); transport of the AP; docking and fusion of the AP with a late endosome or lysosome; and regeneration of the lysosome by the autophagic lysosomal reformation cycle. These events are critically coordinated by the action of a set of several key components, including autophagy-related proteins (Atg), and regulated by intricate networks, such as mechanistic target of rapamycin (mTOR), a master regulator of autophagy, as well as mTOR-independent signaling pathways. Among mTOR-independent pathways, the transient receptor potential (TRP) calcium ion channel TRPML (mucolipin) subfamily is emerging as an important signaling channel to modulate lysosomal biogenesis and autophagy. This review discusses the recent advances in elucidating the molecular mechanisms and regulation of the autophagy process. Understanding these mechanisms may ultimately allow scientists and clinicians to control this process in order to improve human health.
Collapse
Affiliation(s)
| | - Pingyong Xu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
23
|
Yu J, Yang J. Ion channels as potential redox sensors in lysosomes. Channels (Austin) 2019; 13:477-482. [PMID: 31662029 PMCID: PMC6833971 DOI: 10.1080/19336950.2019.1684428] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 08/26/2019] [Accepted: 09/15/2019] [Indexed: 02/08/2023] Open
Abstract
Lysosomes are central organelles that recycle materials and energy to maintain intracellular homeostasis. Lysosomes are capable of sensing environmental cues such as nutrition to regulate their function accordingly. Whether lysosomes can sense redox signaling, however, was unclear. Here in this review, we summarized recent evidence of lysosomal ion channel as redox sensors for this organelle. We also discussed their roles in lysosomal diseases that features imbalanced redox.
Collapse
Affiliation(s)
- Jie Yu
- Sports Science Research Center, Zhejiang College of Sports, Hangzhou, China
| | - Junsheng Yang
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, China
| |
Collapse
|
24
|
Chacon J, Rosas L, Cuajungco MP. ZnT3 expression levels are down-regulated in the brain of Mcoln1 knockout mice. Mol Brain 2019; 12:24. [PMID: 30914059 PMCID: PMC6434829 DOI: 10.1186/s13041-019-0446-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/14/2019] [Indexed: 12/03/2022] Open
Abstract
Aim Zinc is a critical divalent cation in mammalian brain, but its concentration must be strictly-controlled. Within certain subsets of glutamatergic neurons, ZnT3 (encoded by the Slc30a3 gene) facilitates the transport and storage of zinc in synaptic vesicles. It has been previously reported that Slc30a3 mRNA levels are perturbed in numerous neurodegenerative disorders. Given the growing evidence of zinc dysregulation in another neurodegenerative disease known as Mucolipidosis IV (MLIV), we hypothesized that abnormal ZnT3 expression would be observed in the brain of MLIV mouse model. Elucidating the link between abnormal ZnT3 and zinc levels could reveal the neuropathological correlates between MLIV and other age-related brain disorders. Methods Total RNAs from cortical tissues of Mucolipin-1 knockout (Mcoln1−/− KO) and Mcoln1+/+ wild-type (WT) littermate control mice were analyzed for differential gene expression (DGE) using RNA sequencing (RNA-seq). Real-time quantitative PCR (qPCR) and Western blot techniques were used to validate the data. Results RNA-seq analysis showed a marked decrease in baseline levels of Slc30a3 mRNA in Mcoln1−/− mice. Real-time qPCR and Western blot analyses confirmed that Slc30a3 transcripts and its protein levels were significantly reduced. Our observations add MLIV to a growing list of neurodegenerative diseases that parallels abnormal ZnT3 expression with zinc dyshomeostasis. Electronic supplementary material The online version of this article (10.1186/s13041-019-0446-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jonathan Chacon
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd., Fullerton, CA, 92831, USA
| | - Lauren Rosas
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd., Fullerton, CA, 92831, USA
| | - Math P Cuajungco
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd., Fullerton, CA, 92831, USA. .,Center for Applied Biotechnology Studies, California State University Fullerton, Fullerton, CA, 92831, USA.
| |
Collapse
|
25
|
Boudewyn LC, Walkley SU. Current concepts in the neuropathogenesis of mucolipidosis type IV. J Neurochem 2019; 148:669-689. [PMID: 29770442 PMCID: PMC6239999 DOI: 10.1111/jnc.14462] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/29/2018] [Accepted: 05/02/2018] [Indexed: 12/11/2022]
Abstract
Mucolipidosis type IV (MLIV) is an autosomal recessive, lysosomal storage disorder causing progressively severe intellectual disability, motor and speech deficits, retinal degeneration often culminating in blindness, and systemic disease causing a shortened lifespan. MLIV results from mutations in the gene MCOLN1 encoding the transient receptor potential channel mucolipin-1. It is an ultra-rare disease and is currently known to affect just over 100 diagnosed individuals. The last decade has provided a wealth of research focused on understanding the role of the enigmatic mucolipin-1 protein in cell and brain function and how its absence causes disease. This review explores our current understanding of the mucolipin-1 protein in relation to neuropathogenesis in MLIV and describes recent findings implicating mucolipin-1's important role in mechanistic target of rapamycin and TFEB (transcription factor EB) signaling feedback loops as well as in the function of the greater endosomal/lysosomal system. In addition to addressing the vital role of mucolipin-1 in the brain, we also report new data on the question of whether haploinsufficiency as would be anticipated in MCOLN1 heterozygotes is associated with any evidence of neuron dysfunction or disease. Greater insights into the role of mucolipin-1 in the nervous system can be expected to shed light not only on MLIV disease but also on numerous processes governing normal brain function. This article is part of the Special Issue "Lysosomal Storage Disorders".
Collapse
Affiliation(s)
- Lauren C. Boudewyn
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, New York
| | - Steven U. Walkley
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
26
|
Horn A, Jaiswal JK. Cellular mechanisms and signals that coordinate plasma membrane repair. Cell Mol Life Sci 2018; 75:3751-3770. [PMID: 30051163 PMCID: PMC6541445 DOI: 10.1007/s00018-018-2888-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 07/13/2018] [Accepted: 07/23/2018] [Indexed: 02/08/2023]
Abstract
Plasma membrane forms the barrier between the cytoplasm and the environment. Cells constantly and selectively transport molecules across their plasma membrane without disrupting it. Any disruption in the plasma membrane compromises its selective permeability and is lethal, if not rapidly repaired. There is a growing understanding of the organelles, proteins, lipids, and small molecules that help cells signal and efficiently coordinate plasma membrane repair. This review aims to summarize how these subcellular responses are coordinated and how cellular signals generated due to plasma membrane injury interact with each other to spatially and temporally coordinate repair. With the involvement of calcium and redox signaling in single cell and tissue repair, we will discuss how these and other related signals extend from single cell repair to tissue level repair. These signals link repair processes that are activated immediately after plasma membrane injury with longer term processes regulating repair and regeneration of the damaged tissue. We propose that investigating cell and tissue repair as part of a continuum of wound repair mechanisms would be of value in treating degenerative diseases.
Collapse
Affiliation(s)
- Adam Horn
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue, NW, Washington, DC, 20010-2970, USA
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Jyoti K Jaiswal
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue, NW, Washington, DC, 20010-2970, USA.
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.
| |
Collapse
|
27
|
Brini M, Leanza L, Szabo I. Lipid-Mediated Modulation of Intracellular Ion Channels and Redox State: Physiopathological Implications. Antioxid Redox Signal 2018; 28:949-972. [PMID: 28679281 DOI: 10.1089/ars.2017.7215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Significance: Ion channels play an important role in the regulation of organelle function within the cell, as proven by increasing evidence pointing to a link between altered function of intracellular ion channels and different pathologies ranging from cancer to neurodegenerative diseases, ischemic damage, and lysosomal storage diseases. Recent Advances: A link between these pathologies and redox state as well as lipid homeostasis and ion channel function is in the focus of current research. Critical Issues: Ion channels are target of modulation by lipids and lipid messengers, although in most cases the mechanistic details have not been clarified yet. Ion channel function importantly impacts production of reactive oxygen species (ROS), especially in the case of mitochondria and lysosomes. ROS, in turn, may modulate the function of intracellular channels triggering thereby a feedback control under physiological conditions. If produced in excess, ROS can be harmful to lipids and may produce oxidized forms of these membrane constituents that ultimately affect ion channel function by triggering a "circulus vitiosus." Future Directions: The present review summarizes our current knowledge about the contribution of intracellular channels to oxidative stress and gives examples of how these channels are modulated by lipids and how this modulation may affect ROS production in ROS-related diseases. Future studies need to address the importance of the regulation of intracellular ion channels and related oxidative stress by lipids in various physiological and pathological contexts. Antioxid. Redox Signal. 28, 949-972.
Collapse
Affiliation(s)
- Marisa Brini
- Department of Biology, University of Padova, Padova, Italy
| | - Luigi Leanza
- Department of Biology, University of Padova, Padova, Italy
| | - Ildiko Szabo
- Department of Biology, University of Padova, Padova, Italy.,CNR Institute of Neuroscience, Padova, Italy
| |
Collapse
|
28
|
Li H, Pei W, Vergarajauregui S, Zerfas PM, Raben N, Burgess SM, Puertollano R. Novel degenerative and developmental defects in a zebrafish model of mucolipidosis type IV. Hum Mol Genet 2018; 26:2701-2718. [PMID: 28449103 DOI: 10.1093/hmg/ddx158] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 04/19/2017] [Indexed: 12/20/2022] Open
Abstract
Mucolipidosis type IV (MLIV) is a lysosomal storage disease characterized by neurologic and ophthalmologic abnormalities. There is currently no effective treatment. MLIV is caused by mutations in MCOLN1, a lysosomal cation channel from the transient receptor potential (TRP) family. In this study, we used genome editing to knockout the two mcoln1 genes present in Danio rerio (zebrafish). Our model successfully reproduced the retinal and neuromuscular defects observed in MLIV patients, indicating that this model is suitable for studying the disease pathogenesis. Importantly, our model revealed novel insights into the origins and progression of the MLIV pathology, including the contribution of autophagosome accumulation to muscle dystrophy and the role of mcoln1 in embryonic development, hair cell viability and cellular maintenance. The generation of a MLIV model in zebrafish is particularly relevant given the suitability of this organism for large-scale in vivo drug screening, thus providing unprecedented opportunities for therapeutic discovery.
Collapse
Affiliation(s)
- Huiqing Li
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Wuhong Pei
- Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sivia Vergarajauregui
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.,Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Patricia M Zerfas
- Office of Research Services, Division of Veterinary Resources, National Institutes of Health, Bethesda, MD, USA
| | - Nina Raben
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Shawn M Burgess
- Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Rosa Puertollano
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
29
|
Fliniaux I, Germain E, Farfariello V, Prevarskaya N. TRPs and Ca2+ in cell death and survival. Cell Calcium 2018; 69:4-18. [DOI: 10.1016/j.ceca.2017.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 10/19/2022]
|
30
|
Todkar K, Ilamathi HS, Germain M. Mitochondria and Lysosomes: Discovering Bonds. Front Cell Dev Biol 2017; 5:106. [PMID: 29270406 PMCID: PMC5725469 DOI: 10.3389/fcell.2017.00106] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/22/2017] [Indexed: 01/30/2023] Open
Abstract
In the last decade, the traditional view of lysosomes has been challenged by the recognition that lysosomes are not only degradative organelles, but also metabolic sensors that play a key role in the regulation of metabolism and cell growth. Similarly, mitochondria are now seen as crucial metabolic hubs dictating cell fate decisions, not just ATP-producing machines. Importantly, these functions are generally performed as a coordinate response of distinct organelles that are physically and functionally connected. While the association between mitochondria and the endoplasmic reticulum is well known, a similar interaction between mitochondria and lysosomes is now emerging. This interaction could be required to shuttle amino acids, lipids and ions such as Ca2+ between the two organelles, thereby modulating their metabolic functions. In addition, a tethering complex linking the two organelles has recently been described in yeast, although the mammalian counterpart has yet to be identified. Here, we discuss the implications of these recent findings.
Collapse
Affiliation(s)
- Kiran Todkar
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Hema S Ilamathi
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Marc Germain
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| |
Collapse
|
31
|
Di Paola S, Scotto-Rosato A, Medina DL. TRPML1: The Ca (2+)retaker of the lysosome. Cell Calcium 2017; 69:112-121. [PMID: 28689729 DOI: 10.1016/j.ceca.2017.06.006] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/16/2017] [Accepted: 06/16/2017] [Indexed: 12/27/2022]
Abstract
Efficient functioning of lysosome is necessary to ensure the correct performance of a variety of intracellular processes such as degradation of cargoes coming from the endocytic and autophagic pathways, recycling of organelles, and signaling mechanisms involved in cellular adaptation to nutrient availability. Mutations in lysosomal genes lead to more than 50 lysosomal storage disorders (LSDs). Among them, mutations in the gene encoding TRPML1 (MCOLN1) cause Mucolipidosis type IV (MLIV), a recessive LSD characterized by neurodegeneration, psychomotor retardation, ophthalmologic defects and achlorhydria. At the cellular level, MLIV patient fibroblasts show enlargement and engulfment of the late endo-lysosomal compartment, autophagy impairment, and accumulation of lipids and glycosaminoglycans. TRPML1 is the most extensively studied member of a small family of genes that also includes TRPML2 and TRPML3, and it has been found to participate in vesicular trafficking, lipid and ion homeostasis, and autophagy. In this review we will provide an update on the latest and more novel findings related to the functions of TRPMLs, with particular focus on the emerging role of TRPML1 and lysosomal calcium signaling in autophagy. Moreover, we will also discuss new potential therapeutic approaches for MLIV and LSDs based on the modulation of TRPML1-mediated signaling.
Collapse
Affiliation(s)
- Simone Di Paola
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli ,NA, Italy
| | - Anna Scotto-Rosato
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli ,NA, Italy
| | - Diego Luis Medina
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli ,NA, Italy.
| |
Collapse
|
32
|
Ravi S, Peña KA, Chu CT, Kiselyov K. Biphasic regulation of lysosomal exocytosis by oxidative stress. Cell Calcium 2016; 60:356-362. [PMID: 27593159 DOI: 10.1016/j.ceca.2016.08.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 08/26/2016] [Accepted: 08/27/2016] [Indexed: 02/02/2023]
Abstract
Oxidative stress drives cell death in a number of diseases including ischemic stroke and neurodegenerative diseases. A better understanding of how cells recover from oxidative stress is likely to lead to better treatments for stroke and other diseases. The recent evidence obtained in several models ties the process of lysosomal exocytosis to the clearance of protein aggregates and toxic metals. The mechanisms that regulate lysosomal exocytosis, under normal or pathological conditions, are only beginning to emerge. Here we provide evidence for the biphasic effect of oxidative stress on lysosomal exocytosis. Lysosomal exocytosis was measured using the extracellular levels of the lysosomal enzyme beta-hexosaminidase (ß-hex). Low levels or oxidative stress stimulated lysosomal exocytosis, but inhibited it at high levels. Deletion of the lysosomal ion channel TRPML1 eliminated the stimulatory effect of low levels of oxidative stress. The inhibitory effects of oxidative stress appear to target the component of lysosomal exocytosis that is driven by extracellular Ca2+. We propose that while moderate oxidative stress promotes cellular repair by stimulating lysosomal exocytosis, at high levels oxidative stress has a dual pathological effect: it directly causes cell damage and impairs damage repair by inhibiting lysosomal exocytosis. Harnessing these adaptive mechanisms may point to pharmacological interventions for diseases involving oxidative proteotoxicity or metal toxicity.
Collapse
Affiliation(s)
- Sreeram Ravi
- Department of Biological Sciences, Pittsburgh, PA 15260, USA
| | - Karina A Peña
- Department of Biological Sciences, Pittsburgh, PA 15260, USA
| | - Charleen T Chu
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Kirill Kiselyov
- Department of Biological Sciences, Pittsburgh, PA 15260, USA.
| |
Collapse
|
33
|
Onyenwoke RU, Brenman JE. Lysosomal Storage Diseases-Regulating Neurodegeneration. J Exp Neurosci 2016; 9:81-91. [PMID: 27081317 PMCID: PMC4822725 DOI: 10.4137/jen.s25475] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/11/2015] [Accepted: 11/16/2015] [Indexed: 12/19/2022] Open
Abstract
Autophagy is a complex pathway regulated by numerous signaling events that recycles macromolecules and can be perturbed in lysosomal storage diseases (LSDs). The concept of LSDs, which are characterized by aberrant, excessive storage of cellular material in lysosomes, developed following the discovery of an enzyme deficiency as the cause of Pompe disease in 1963. Great strides have since been made in better understanding the biology of LSDs. Defective lysosomal storage typically occurs in many cell types, but the nervous system, including the central nervous system and peripheral nervous system, is particularly vulnerable to LSDs, being affected in two-thirds of LSDs. This review provides a summary of some of the better characterized LSDs and the pathways affected in these disorders.
Collapse
Affiliation(s)
- Rob U Onyenwoke
- Department of Pharmaceutical Science, Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, NC, USA
| | - Jay E Brenman
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
34
|
Kiselyov K, Muallem S. ROS and intracellular ion channels. Cell Calcium 2016; 60:108-14. [PMID: 26995054 DOI: 10.1016/j.ceca.2016.03.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 12/15/2022]
Abstract
Oxidative stress is a well-known driver of numerous pathological processes involving protein and lipid peroxidation and DNA damage. The resulting increase of pro-apoptotic pressure drives tissue damage in a host of conditions, including ischemic stroke and reperfusion injury, diabetes, death in acute pancreatitis and neurodegenerative diseases. Somewhat less frequently discussed, but arguably as important, is the signaling function of oxidative stress stemming from the ability of oxidative stress to modulate ion channel activity. The evidence for the modulation of the intracellular ion channels and transporters by oxidative stress is constantly emerging and such evidence suggests new regulatory and pathological circuits that can be explored towards new treatments for diseases in which oxidative stress is an issue. In this review we summarize the current knowledge on the effects of oxidative stress on the intracellular ion channels and transporters and their role in cell function.
Collapse
Affiliation(s)
- Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States; Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch NIH, NIDCR, Bethesda, MD 20892, United States.
| | - Shmuel Muallem
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States; Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch NIH, NIDCR, Bethesda, MD 20892, United States.
| |
Collapse
|
35
|
Grishchuk Y, Peña KA, Coblentz J, King VE, Humphrey DM, Wang SL, Kiselyov KI, Slaugenhaupt SA. Impaired myelination and reduced brain ferric iron in the mouse model of mucolipidosis IV. Dis Model Mech 2015; 8:1591-601. [PMID: 26398942 PMCID: PMC4728313 DOI: 10.1242/dmm.021154] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 09/08/2015] [Indexed: 12/11/2022] Open
Abstract
Mucolipidosis type IV (MLIV) is a lysosomal storage disease caused by mutations in the MCOLN1 gene, which encodes the lysosomal transient receptor potential ion channel mucolipin-1 (TRPML1). MLIV causes impaired motor and cognitive development, progressive loss of vision and gastric achlorhydria. How loss of TRPML1 leads to severe psychomotor retardation is currently unknown, and there is no therapy for MLIV. White matter abnormalities and a hypoplastic corpus callosum are the major hallmarks of MLIV brain pathology. Here, we report that loss of TRPML1 in mice results in developmental aberrations of brain myelination as a result of deficient maturation and loss of oligodendrocytes. Defective myelination is evident in Mcoln1(-/-) mice at postnatal day 10, an active stage of postnatal myelination in the mouse brain. Expression of mature oligodendrocyte markers is reduced in Mcoln1(-/-) mice at postnatal day 10 and remains lower throughout the course of the disease. We observed reduced Perls' staining in Mcoln1(-/-) brain, indicating lower levels of ferric iron. Total iron content in unperfused brain is not significantly different between Mcoln1(-/-) and wild-type littermate mice, suggesting that the observed maturation delay or loss of oligodendrocytes might be caused by impaired iron handling, rather than by global iron deficiency. Overall, these data emphasize a developmental rather than a degenerative disease course in MLIV, and suggest that there should be a stronger focus on oligodendrocyte maturation and survival to better understand MLIV pathogenesis and aid treatment development.
Collapse
Affiliation(s)
- Yulia Grishchuk
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Karina A Peña
- Department of Biological Sciences, University of Pittsburgh, 519 Langley Hall, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Jessica Coblentz
- Department of Biological Sciences, University of Pittsburgh, 519 Langley Hall, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Victoria E King
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Daniel M Humphrey
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Shirley L Wang
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Kirill I Kiselyov
- Department of Biological Sciences, University of Pittsburgh, 519 Langley Hall, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Susan A Slaugenhaupt
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| |
Collapse
|
36
|
Cuajungco MP, Silva J, Habibi A, Valadez JA. The mucolipin-2 (TRPML2) ion channel: a tissue-specific protein crucial to normal cell function. Pflugers Arch 2015; 468:177-92. [PMID: 26336837 DOI: 10.1007/s00424-015-1732-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 08/25/2015] [Accepted: 08/27/2015] [Indexed: 12/26/2022]
Abstract
The discovery of the TRPML subfamily of ion channels has created an exciting niche in the fields of membrane trafficking, signal transduction, autophagy, and metal homeostasis. The TRPML protein subfamily consists of three members, TRPML1, TRPML2, and TRPML3, which are encoded by MCOLN1, MCOLN2, and MCOLN3 genes, respectively. They are non-selective cation channels with six predicted transmembrane domains and intracellular amino- and carboxyl-terminus regions. They localize to the plasma membrane, endosomes, and lysosomes of cells. TRPML1 is associated with the human lysosomal storage disease known as mucolipidosis type IV (MLIV), but TRPML2 and TRPML3 have not been linked with a human disease. Although TRPML1 is expressed in many tissues, TRPML3 is expressed in a varied but limited set of tissues, while TRPML2 has a more limited expression pattern where it is mostly detected in lymphoid and myeloid tissues. This review focuses on TRPML2 because it appears to play an important, yet unrecognized role in the immune system. While the evidence has been mostly indirect, we present and discuss relevant data that strengthen the connection of TRPML2 with cellular immunity. We also discuss the functional redundancy between the TRPML proteins, and how such features could be exploited as a potential therapeutic strategy for MLIV disease. We present evidence that TRPML2 expression may complement certain phenotypic alterations in MLIV cells and briefly examine the challenges of functional complementation. In conclusion, the function of TRPML2 still remains obscure, but emerging data show that it may serve a critical role in immune cell development and inflammatory responses.
Collapse
Affiliation(s)
- Math P Cuajungco
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd., Fullerton, CA, 92831, USA. .,Center for Applied Biotechnology Studies, California State University Fullerton, Fullerton, CA, 92831, USA.
| | - Joshua Silva
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd., Fullerton, CA, 92831, USA
| | - Ania Habibi
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd., Fullerton, CA, 92831, USA
| | - Jessica A Valadez
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd., Fullerton, CA, 92831, USA
| |
Collapse
|
37
|
Abstract
Exposure of cells to micromolar Cu activates recombinant transcription factor EB (TFEB), leading to expression of the lysosomal network genes. Whereas TFEB overexpression has a cytoprotective effect under moderate Cu exposure, it enhances oxidative stress and mitochondrial damage caused by high levels of Cu. Transition metal toxicity is an important factor in the pathogenesis of numerous human disorders, including neurodegenerative diseases. Lysosomes have emerged as important factors in transition metal toxicity because they handle transition metals via endocytosis, autophagy, absorption from the cytoplasm and exocytosis. Transcription factor EB (TFEB) regulates lysosomal biogenesis and the expression of lysosomal proteins in response to lysosomal and/or metabolic stresses. Since transition metals cause lysosomal dysfunction, we proposed that TFEB may be activated to drive gene expression in response to transition metal exposure and that such activation may influence transition metal toxicity. We found that transition metals copper (Cu) and iron (Fe) activate recombinant TFEB and stimulate the expression of TFEB-dependent genes in TFEB-overexpressing cells. In cells that show robust lysosomal exocytosis, TFEB was cytoprotective at moderate levels of Cu exposure, decreasing oxidative stress as reported by the expression of heme oxygenase-1 (HMOX1) gene. However, at high levels of Cu exposure, particularly in cells with low levels of lysosomal exocytosis, activation of overexpressed TFEB was toxic, increasing oxidative stress and mitochondrial damage. Based on these data, we conclude that TFEB-driven gene network is a component of the cellular response to transition metals. These data suggest limitations and disadvantages of TFEB overexpression as a therapeutic approach.
Collapse
|
38
|
Mirabelli-Badenier M, Severino M, Tappino B, Tortora D, Camia F, Zanaboni C, Brera F, Priolo E, Rossi A, Biancheri R, Di Rocco M, Filocamo M. A novel homozygous MCOLN1 double mutant allele leading to TRP channel domain ablation underlies Mucolipidosis IV in an Italian Child. Metab Brain Dis 2015; 30:681-6. [PMID: 25156245 DOI: 10.1007/s11011-014-9612-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 08/15/2014] [Indexed: 10/24/2022]
Abstract
Mucolipidosis type IV (MLIV) is a very rare disorder of late endosome/lysosome transport, characterized by neurodevelopmental abnormalities and progressive visual impairment owing to corneal clouding and retinal dystrophy. Greater than 70 % of MLIV patients are of Ashkenazi Jewish ancestry. Here we report a novel MCOLN1double mutant allele [c.395_397delCTG;c.468_474dupTTGGACC] which introduces a premature stop codon [p.Ala132del; p.Asn159LeufsX27] leading to almost complete abrogation of the region coding mucolipin-1, a member of the transient receptor potential (TRP) cation channel family. The genomic lesion was identified in homozygous state, in a non-Jewish Italian MLIV patient, who also presented abnormal serum gastrin levels. Conventional and advanced MRI sequences, including diffusion tensor imaging and tractography, were used for the assessment of white matter involvement in the patient.
Collapse
|
39
|
Brief exposure to copper activates lysosomal exocytosis. Cell Calcium 2015; 57:257-62. [PMID: 25620123 DOI: 10.1016/j.ceca.2015.01.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/23/2014] [Accepted: 01/05/2015] [Indexed: 11/20/2022]
Abstract
Copper (Cu) is essential mineral, but its toxicity necessitates existence of powerful machinery responsible for the extraction of excess Cu from the cell. Cu exposure was recently shown to induce the translocation of Cu pump ATP7B to the lysosomes followed by lysosomal exocytosis. Here we sought to investigate the mechanisms underlying the effect of Cu on lysosomal exocytosis. We found that brief exposure to Cu activates lysosomal exocytosis, which was measured as a release of the lysosomal digestive enzyme β-hexosaminidase (β-hex) into the extracellular medium and by the presence lysosomal protein LAMP1 at the plasma membrane. Such release depends on calcium (Ca) and on the lysosomal SNARE VAMP7. ATP7B knockdown using RNAi suppressed the basal lysosomal exocytosis, but did not affect the ability of Cu to activate it. ATP7B knockdown was associated with sustained oxidative stress. The removal of Ca from the extracellular medium suppressed the Cu-dependent component of the lysosomal exocytosis. We propose that Cu promotes lysosomal exocytosis by facilitating a Ca-dependent step of the lysosomal exocytosis.
Collapse
|
40
|
The role of TRPMLs in endolysosomal trafficking and function. Cell Calcium 2014; 58:48-56. [PMID: 25465891 DOI: 10.1016/j.ceca.2014.10.008] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/15/2014] [Accepted: 10/17/2014] [Indexed: 12/24/2022]
Abstract
Members of the Transient Receptor Potential-Mucolipin (TRPML) constitute a family of evolutionarily conserved cation channels that function predominantly in endolysosomal vesicles. Whereas loss-of-function mutations in human TRPML1 were first identified as being causative for the lysosomal storage disease, Mucolipidosis type IV, most mammals also express two other TRPML isoforms called TRPML2 and TRPML3. All three mammalian TRPMLs as well as TRPML related genes in other species including Caenorhabditis elegans and Drosophila exhibit overlapping functional and biophysical properties. The functions of TRPML proteins include roles in vesicular trafficking and biogenesis, maintenance of neuronal development, function, and viability, and regulation of intracellular and organellar ionic homeostasis. Biophysically, TRPML channels are non-selective cation channels exhibiting variable permeability to a host of cations including Na(+), Ca(2+), Fe(2+), and Zn(2+), and are activated by a phosphoinositide species, PI(3,5)P2, that is mostly found in endolysosomal membranes. Here, we review the functional and biophysical properties of these enigmatic cation channels, which represent the most ancient and archetypical TRP channels.
Collapse
|
41
|
Guha S, Coffey EE, Lu W, Lim JC, Beckel JM, Laties AM, Boesze-Battaglia K, Mitchell CH. Approaches for detecting lysosomal alkalinization and impaired degradation in fresh and cultured RPE cells: evidence for a role in retinal degenerations. Exp Eye Res 2014; 126:68-76. [PMID: 25152362 DOI: 10.1016/j.exer.2014.05.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 05/15/2014] [Accepted: 05/18/2014] [Indexed: 01/20/2023]
Abstract
Lysosomes contribute to a multitude of cellular processes, and the pH of the lysosomal lumen plays a central mechanistic role in many of these functions. In addition to controlling the rate of enzymatic degradation for material delivered through autophagic or phagocytotic pathways, lysosomal pH regulates events such as lysosomal fusion with autophagosomes and the release of lysosomal calcium into the cytoplasm. Disruption of either the steady state lysosomal pH or of the regulated manipulations to lysosomal pH may be pathological. For example, chloroquine elevates the lysosomal pH of retinal pigmented epithelial (RPE) cells and triggers a retinopathy characterized by the accumulation of lipofuscin-like material in both humans and animals. Compensatory responses to restore lysosomal pH are observed; new data illustrate that chronic chloroquine treatment increases mRNA expression of the lysosomal/autophagy master transcription factor TcFEB and of the vesicular proton pump vHATPase in the RPE/choroid of mice. An elevated lysosomal pH with upregulation of TcFEB and vHATPase resembles the pathology in fibroblasts of patients with mutant presenilin 1 (PS1), suggesting a common link between age-related macular degeneration (AMD) and Alzheimer's disease. While the absolute rise in pH is often small in these disorders, elevations of only a few tenths of a pH unit can have a major impact on both lysosomal function and the accumulation of waste over decades. Accurate measurement of lysosomal pH can be complex, and imprecise measurements have clouded the field. Protocols to optimize pH measurement from fresh and cultured cells are discussed, and indirect measurements to confirm changes in lysosomal pH and degradative capacity are addressed. The ability of reacidifying treatments to restore degradative function confirms the central role of lysosomal pH in these disorders and identifies potential approaches to treat diseases of lysosomal accumulation like AMD and Alzheimer's disease. In summary, various approaches to determine lysosomal pH in fresh and cultured cells, as well as the potential to restore pH levels to an optimal range, can help identify and repair pathologies associated with lysosomal defects in RPE cells and perhaps also suggest new approaches to treat lysosomal storage diseases throughout the body.
Collapse
Affiliation(s)
- Sonia Guha
- Departments of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA; Department of Ophthalmology, University of California at Los Angeles, Los Angeles, CA, USA
| | - Erin E Coffey
- Departments of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Wennan Lu
- Departments of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jason C Lim
- Departments of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jonathan M Beckel
- Departments of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA; Department of Anesthesiology, University of Pittsburgh, USA
| | - Alan M Laties
- Departments of Ophthalmology University of Pennsylvania, Philadelphia, PA, USA
| | | | - Claire H Mitchell
- Departments of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA; Departments of Physiology, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
42
|
Permeation, regulation and control of expression of TRP channels by trace metal ions. Pflugers Arch 2014; 467:1143-64. [PMID: 25106481 PMCID: PMC4435931 DOI: 10.1007/s00424-014-1590-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/10/2014] [Accepted: 07/13/2014] [Indexed: 01/26/2023]
Abstract
Transient receptor potential (TRP) channels form a diverse family of cation channels comprising 28 members in mammals. Although some TRP proteins can only be found on intracellular membranes, most of the TRP protein isoforms reach the plasma membrane where they form ion channels and control a wide number of biological processes. There, their involvement in the transport of cations such as calcium and sodium has been well documented. However, a growing number of studies have started to expand our understanding of these proteins by showing that they also transport other biologically relevant metal ions like zinc, magnesium, manganese and cobalt. In addition to this newly recognized property, the activity and expression of TRP channels can be regulated by metal ions like magnesium, gadolinium, lanthanum or cisplatin. The aim of this review is to highlight the complex relationship between metal ions and TRP channels.
Collapse
|