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Khazma T, Grossman A, Guez-Haddad J, Feng C, Dabas H, Sain R, Weitman M, Zalk R, Isupov MN, Hammarlund M, Hons M, Opatowsky Y. Structure-function analysis of ceTIR-1/hSARM1 explains the lack of Wallerian axonal degeneration in C. elegans. Cell Rep 2023; 42:113026. [PMID: 37635352 PMCID: PMC10675840 DOI: 10.1016/j.celrep.2023.113026] [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: 01/07/2023] [Revised: 06/05/2023] [Accepted: 08/09/2023] [Indexed: 08/29/2023] Open
Abstract
Wallerian axonal degeneration (WD) does not occur in the nematode C. elegans, in contrast to other model animals. However, WD depends on the NADase activity of SARM1, a protein that is also expressed in C. elegans (ceSARM/ceTIR-1). We hypothesized that differences in SARM between species might exist and account for the divergence in WD. We first show that expression of the human (h)SARM1, but not ceTIR-1, in C. elegans neurons is sufficient to confer axon degeneration after nerve injury. Next, we determined the cryoelectron microscopy structure of ceTIR-1 and found that, unlike hSARM1, which exists as an auto-inhibited ring octamer, ceTIR-1 forms a readily active 9-mer. Enzymatically, the NADase activity of ceTIR-1 is substantially weaker (10-fold higher Km) than that of hSARM1, and even when fully active, it falls short of consuming all cellular NAD+. Our experiments provide insight into the molecular mechanisms and evolution of SARM orthologs and WD across species.
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Affiliation(s)
- Tami Khazma
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Atira Grossman
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Julia Guez-Haddad
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Chengye Feng
- Departments of Neuroscience and Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Hadas Dabas
- Departments of Neuroscience and Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Radhika Sain
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Michal Weitman
- Department of Chemistry, Bar-Ilan University, Ramat Gan, Israel
| | - Ran Zalk
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Michail N Isupov
- Henry Wellcome Building for Biocatalysis, Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Marc Hammarlund
- Departments of Neuroscience and Genetics, Yale School of Medicine, New Haven, CT, USA.
| | - Michael Hons
- European Molecular Biology Laboratory, Grenoble, France.
| | - Yarden Opatowsky
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
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Ding C, Wu Y, Dabas H, Hammarlund M. Activation of the CaMKII-Sarm1-ASK1-p38 MAP kinase pathway protects against axon degeneration caused by loss of mitochondria. eLife 2022; 11:73557. [PMID: 35285800 PMCID: PMC8920508 DOI: 10.7554/elife.73557] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/25/2022] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial defects are tightly linked to axon degeneration, yet the underlying cellular mechanisms remain poorly understood. In Caenorhabditis elegans, PVQ axons that lack mitochondria degenerate spontaneously with age. Using an unbiased genetic screen, we found that cell-specific activation of CaMKII/UNC-43 suppresses axon degeneration due to loss of mitochondria. Unexpectedly, CaMKII/UNC-43 activates the conserved Sarm1/TIR-1-ASK1/NSY-1-p38 MAPK pathway and eventually the transcription factor CEBP-1 to protect against degeneration. In addition, we show that disrupting a trafficking complex composed of calsyntenin/CASY-1, Mint/LIN-10, and kinesin suppresses axon degeneration. Further analysis indicates that disruption of this trafficking complex activates the CaMKII-Sarm1-MAPK pathway through L-type voltage-gated calcium channels. Our findings identify CaMKII as a pivot point between mitochondrial defects and axon degeneration, describe how it is regulated, and uncover a surprising neuroprotective role for the Sarm1-p38 MAPK pathway in this context.
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Affiliation(s)
- Chen Ding
- Department of Neuroscience, Yale University School of MedicineNew HavenUnited States
| | - Youjun Wu
- Department of Genetics, Yale University School of MedicineNew HavenUnited States
| | - Hadas Dabas
- Department of Genetics, Yale University School of MedicineNew HavenUnited States
| | - Marc Hammarlund
- Department of Neuroscience, Yale University School of MedicineNew HavenUnited States,Department of Genetics, Yale University School of MedicineNew HavenUnited States
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Cui Z, Dabas H, Leonard BC, Shiah JV, Grandis JR, Johnson DE. Caspase-8 mutations associated with head and neck cancer differentially retain functional properties related to TRAIL-induced apoptosis and cytokine induction. Cell Death Dis 2021; 12:775. [PMID: 34362880 PMCID: PMC8346537 DOI: 10.1038/s41419-021-04066-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022]
Abstract
The cysteine protease, caspase-8, undergoes dimerization, processing, and activation following stimulation of cells with death ligands such as TRAIL, and mediates TRAIL induction of the extrinsic apoptosis pathway. In addition, caspase-8 mediates TRAIL-induced activation of NF-κB and upregulation of immunosuppressive chemokines/cytokines, via a mechanism independent of caspase-8 catalytic activity. The gene encoding procaspase-8 is mutated in 10% of human head and neck squamous cell carcinomas (HNSCCs). Despite a paucity of experimental evidence, HNSCC-associated caspase-8 mutations are commonly assumed to be loss of function. To investigate their functional properties and phenotypic effects, 18 HNSCC-associated caspase-8 mutants were expressed in doxycycline-inducible fashion in cell line models wherein the endogenous wild-type caspase-8 was deleted. We observed that 5/8 mutants in the amino-terminal prodomain, but 0/10 mutants in the carboxyl-terminal catalytic region, retained an ability to mediate TRAIL-induced apoptosis. Caspase-8 proteins with mutations in the prodomain were defective in dimerization, whereas all ten of the catalytic region mutants efficiently dimerized, revealing an inverse relationship between dimerization and apoptosis induction for the mutant proteins. Roughly half (3/8) of the prodomain mutants and 9/10 of the catalytic region mutants retained the ability to mediate TRAIL induction of immunosuppressive CXCL1, IL-6, or IL-8. Doxycycline-induced expression of wild-type caspase-8 or a representative mutant led to an increased percentage of T and NKT cells in syngeneic HNSCC xenograft tumors. These findings demonstrate that HNSCC-associated caspase-8 mutants retain properties that may influence TRAIL-mediated apoptosis and cytokine induction, as well as the composition of the tumor microenvironment.
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Affiliation(s)
- Zhibin Cui
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Hadas Dabas
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Brandon C Leonard
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Jamie V Shiah
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Jennifer R Grandis
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Daniel E Johnson
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, CA, USA.
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Maheshwari P, Chauhan K, Kadam R, Pujani A, Kaur M, Chitalia M, Dabas H, Perkins MD, Boehme CC, Denkinger CM, Raizada N, Ginnard J, Jefferson C, Pantoja A, Rupert S, Kik SV, Cohen C, Chedore P, Satyanarayana S, Pai M. Market assessment of tuberculosis diagnostics in India in 2013. Int J Tuberc Lung Dis 2017; 20:304-13. [PMID: 27046709 DOI: 10.5588/ijtld.15.0571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND India represents a significant potential market for new tests. We assessed India's market for tuberculosis (TB) diagnostics in 2013. METHODS Test volumes and unit costs were assessed for tuberculin tests, interferon-gamma release assays, sputum smear microscopy, serology, culture, speciation testing, nucleic-acid amplification tests (i.e., in-house polymerase chain reaction, Xpert(®) MTB/RIF, line-probe assays) and drug susceptibility testing. Data from the public sector were collected from the Revised National TB Control Programme reports. Private sector data were collected through a survey of private laboratories and practitioners. Data were also collected from manufacturers. RESULTS In 2013, India's public sector performed 19.2 million tests, with a market value of US$22.9 million. The private sector performed 13.6 million tests, with a market value of US$60.4 million when prices charged to the patient were applied. The overall market was US$70.8 million when unit costs from the ingredient approach were used for the 32.8 million TB tests performed in the entire country. Smear microscopy was the most common test performed, accounting for 25% of the overall market value. CONCLUSION India's estimated market value for TB diagnostics in 2013 was US$70.8 million. These data should be of relevance to test developers, donors and implementers.
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Affiliation(s)
- P Maheshwari
- Clinton Health Access Initiative [CHAI], New Delhi, India
| | - K Chauhan
- Clinton Health Access Initiative [CHAI], New Delhi, India
| | - R Kadam
- Clinton Health Access Initiative [CHAI], New Delhi, India
| | - A Pujani
- Clinton Health Access Initiative [CHAI], New Delhi, India
| | - M Kaur
- Clinton Health Access Initiative [CHAI], New Delhi, India
| | - M Chitalia
- Clinton Health Access Initiative [CHAI], New Delhi, India
| | - H Dabas
- Clinton Health Access Initiative [CHAI], New Delhi, India
| | - M D Perkins
- Foundation for Innovative New Diagnostics [FIND], Geneva, Switzerland
| | - C C Boehme
- Foundation for Innovative New Diagnostics [FIND], Geneva, Switzerland
| | - C M Denkinger
- Foundation for Innovative New Diagnostics [FIND], Geneva, Switzerland
| | - N Raizada
- Foundation for Innovative New Diagnostics [FIND], Geneva, Switzerland
| | | | - C Jefferson
- Independent consultant, currently consulting for FIND and UNITAID, Philadelphia, Pennsylvania, USA
| | - A Pantoja
- Independent consultant, Zurich, Switzerland
| | - S Rupert
- Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
| | - S V Kik
- McGill International TB Centre, Montreal, Quebec, Canada
| | - C Cohen
- McGill International TB Centre, Montreal, Quebec, Canada
| | - P Chedore
- McGill International TB Centre, Montreal, Quebec, Canada
| | | | - M Pai
- McGill Global Health Programs, Department of Epidemiology & Biostatistics, McGill International TB Centre, 1020 Pine Ave West, Montreal, QC, Canada H3A 1A2.
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