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Pumroy RA, De Jesús-Pérez JJ, Protopopova AD, Rocereta JA, Fluck EC, Fricke T, Lee BH, Rohacs T, Leffler A, Moiseenkova-Bell V. Molecular details of ruthenium red pore block in TRPV channels. EMBO Rep 2024; 25:506-523. [PMID: 38225355 PMCID: PMC10897480 DOI: 10.1038/s44319-023-00050-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/17/2024] Open
Abstract
Transient receptor potential vanilloid (TRPV) channels play a critical role in calcium homeostasis, pain sensation, immunological response, and cancer progression. TRPV channels are blocked by ruthenium red (RR), a universal pore blocker for a wide array of cation channels. Here we use cryo-electron microscopy to reveal the molecular details of RR block in TRPV2 and TRPV5, members of the two TRPV subfamilies. In TRPV2 activated by 2-aminoethoxydiphenyl borate, RR is tightly coordinated in the open selectivity filter, blocking ion flow and preventing channel inactivation. In TRPV5 activated by phosphatidylinositol 4,5-bisphosphate, RR blocks the selectivity filter and closes the lower gate through an interaction with polar residues in the pore vestibule. Together, our results provide a detailed understanding of TRPV subfamily pore block, the dynamic nature of the selectivity filter and allosteric communication between the selectivity filter and lower gate.
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Affiliation(s)
- Ruth A Pumroy
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - José J De Jesús-Pérez
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Anna D Protopopova
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Julia A Rocereta
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Edwin C Fluck
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Tabea Fricke
- Institute for Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - Bo-Hyun Lee
- Department of Physiology and Convergence Medical Science, Institute of Health Sciences, Gyeongsang National University Medical School, Jinju, Korea
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA
| | - Andreas Leffler
- Institute for Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - Vera Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Gabner S, Böck P, Fink D, Glösmann M, Handschuh S. The visible skeleton 2.0: phenotyping of cartilage and bone in fixed vertebrate embryos and foetuses based on X-ray microCT. Development 2020; 147:dev187633. [PMID: 32439754 DOI: 10.1242/dev.187633] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Accepted: 04/23/2020] [Indexed: 01/14/2023]
Abstract
For decades, clearing and staining with Alcian Blue and Alizarin Red has been the gold standard to image vertebrate skeletal development. Here, we present an alternate approach to visualise bone and cartilage based on X-ray microCT imaging, which allows the collection of genuine 3D data of the entire developing skeleton at micron resolution. Our novel protocol is based on ethanol fixation and staining with Ruthenium Red, and efficiently contrasts cartilage matrix, as demonstrated in whole E16.5 mouse foetuses and limbs of E14 chicken embryos. Bone mineral is well preserved during staining, thus the entire embryonic skeleton can be imaged at high contrast. Differences in X-ray attenuation of ruthenium and calcium enable the spectral separation of cartilage matrix and bone by dual energy microCT (microDECT). Clearing of specimens is not required. The protocol is simple and reproducible. We demonstrate that cartilage contrast in E16.5 mouse foetuses is adequate for fast visual phenotyping. Morphometric skeletal parameters are easily extracted. We consider the presented workflow to be a powerful and versatile extension to the toolkit currently available for qualitative and quantitative phenotyping of vertebrate skeletal development.
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Affiliation(s)
- Simone Gabner
- Histology and Embryology, Department for Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
| | - Peter Böck
- Histology and Embryology, Department for Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
| | - Dieter Fink
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Veterinaärplatz 1, A-1210 Vienna, Austria
| | - Martin Glösmann
- VetCore Facility for Research/Imaging Unit, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
| | - Stephan Handschuh
- VetCore Facility for Research/Imaging Unit, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Vienna, Austria
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Medvedeva YV, Weiss JH. Intramitochondrial Zn2+ accumulation via the Ca2+ uniporter contributes to acute ischemic neurodegeneration. Neurobiol Dis 2014; 68:137-44. [PMID: 24787898 DOI: 10.1016/j.nbd.2014.04.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/02/2014] [Accepted: 04/21/2014] [Indexed: 01/02/2023] Open
Abstract
Ca(2+) and Zn(2+) have both been implicated in the induction of acute ischemic neurodegeneration. We recently examined changes in intracellular Zn(2+) and Ca(2+) in CA1 pyramidal neurons subjected to oxygen glucose deprivation (OGD), and found that Zn(2+) rises precede and contribute to the onset of terminal Ca(2+) rises ("Ca(2+) deregulation"), which are causatively linked to a lethal loss of membrane integrity. The present study seeks to examine the specific role of intramitochondrial Zn(2+) accumulation in ischemic injury, using blockers of the mitochondrial Ca(2+) uniporter (MCU), through which both Zn(2+) and Ca(2+) appear able to enter the mitochondrial matrix. In physiological extracellular Ca(2+), treatment with the MCU blocker, Ruthenium Red (RR), accelerated the Ca(2+) deregulation, most likely by disrupting mitochondrial Ca(2+) buffering and thus accelerating the lethal cytosolic Ca(2+) overload. However, when intracellular Ca(2+) overload was slowed, either by adding blockers of major Ca(2+) entry channels or by lowering the concentration of Ca(2+) in the extracellular buffer, Ca(2+) deregulation was delayed, and under these conditions either Zn(2+) chelation or MCU blockade resulted in similar further delays of the Ca(2+) deregulation. In parallel studies using the reactive oxygen species (ROS) indicator, hydroethidine, lowering Ca(2+) surprisingly accelerated OGD induced ROS generation, and in these low Ca(2+) conditions, either Zn(2+) chelation or MCU block slowed the ROS generation. These studies suggest that, during acute ischemia, Zn(2+) entry into mitochondria via the MCU induces mitochondrial dysfunction (including ROS generation) that occurs upstream of, and contributes to the terminal Ca(2+) deregulation.
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Affiliation(s)
- Yuliya V Medvedeva
- Department of Neurology, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA 92697, USA.
| | - John H Weiss
- Department of Neurology, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA 92697, USA.
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