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Sweetat S, Nitzan K, Suissa N, Haimovich Y, Lichtenstein M, Zabit S, Benhamron S, Akarieh K, Mishra K, Barasch D, Saada A, Ziv T, Kakhlon O, Lorberboum-Galski H, Rosenmann H. The Beneficial Effect of Mitochondrial Transfer Therapy in 5XFAD Mice via Liver–Serum–Brain Response. Cells 2023; 12:cells12071006. [PMID: 37048079 PMCID: PMC10093713 DOI: 10.3390/cells12071006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/15/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
We recently reported the benefit of the IV transferring of active exogenous mitochondria in a short-term pharmacological AD (Alzheimer’s disease) model. We have now explored the efficacy of mitochondrial transfer in 5XFAD transgenic mice, aiming to explore the underlying mechanism by which the IV-injected mitochondria affect the diseased brain. Mitochondrial transfer in 5XFAD ameliorated cognitive impairment, amyloid burden, and mitochondrial dysfunction. Exogenously injected mitochondria were detected in the liver but not in the brain. We detected alterations in brain proteome, implicating synapse-related processes, ubiquitination/proteasome-related processes, phagocytosis, and mitochondria-related factors, which may lead to the amelioration of disease. These changes were accompanied by proteome/metabolome alterations in the liver, including pathways of glucose, glutathione, amino acids, biogenic amines, and sphingolipids. Altered liver metabolites were also detected in the serum of the treated mice, particularly metabolites that are known to affect neurodegenerative processes, such as carnosine, putrescine, C24:1-OH sphingomyelin, and amino acids, which serve as neurotransmitters or their precursors. Our results suggest that the beneficial effect of mitochondrial transfer in the 5XFAD mice is mediated by metabolic signaling from the liver via the serum to the brain, where it induces protective effects. The high efficacy of the mitochondrial transfer may offer a novel AD therapy.
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Sweetat S, Casden N, Behar O. Improved neuron protection following cortical injury in the absence of Semaphorin4B. Front Cell Neurosci 2022; 16:1076281. [DOI: 10.3389/fncel.2022.1076281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 11/15/2022] [Indexed: 12/05/2022] Open
Abstract
Injury to the central nervous system induces neuronal cell death and astrogliosis, an astrocyte-mediated response that has both a beneficial and detrimental impact on surrounding neuronal cells. The circumstance however, in which astrogliosis improves neuronal survival after an injury is not fully characterized. We have recently shown that Semaphorin4B (Sema4B) in the cortex is mostly expressed by astrocytes, and in its absence, astrocyte activation after an injury is altered. Here we find that in Sema4B knockout mice, neuronal cell death is reduced; as a result, more neurons survive near the injury site. Sema4B protein applied directly to neurons does not affect neuronal survival. In contrast, survival of wild-type neurons is increased when plated on glial culture isolated from the Sema4B knockout mice, as compared to Sema4B heterozygous cultures. Furthermore, this increased survival is also observed with conditioned medium collected from glial cultures of Sema4B knockout mice compared to heterozygous mice. This indicates that the increased survival is glial cell-dependent and mediated by a secreted factor(s). Together, our results imply that following injury, the lack of Sema4B expression in glial cells improves neuronal survival either as a result of reduced toxic factors, or perhaps increased survival factors under these conditions.
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Samuel I, Ben-Haroush Schyr R, Arad Y, Attali T, Azulai S, Bergel M, Halfon A, Hefetz L, Hirsch T, Israeli H, Lax N, Nitzan K, Sender D, Sweetat S, Okun E, Rosenmann H, Ben-Zvi D. Sleeve Gastrectomy Reduces Glycemia but Does Not Affect Cognitive Impairment in Lean 5xFAD Mice. Front Neurosci 2022; 16:937663. [PMID: 36033613 PMCID: PMC9403181 DOI: 10.3389/fnins.2022.937663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/23/2022] [Indexed: 11/13/2022] Open
Abstract
Obesity and hyperglycemia are risk factors for cognitive decline and for the development of Alzheimer’s Disease (AD). Bariatric surgery is an effective treatment for obesity that was shown to improve cognitive decline in obese patients. Bariatric surgery was shown to exert weight loss independent effects on metabolic diseases such as type 2 diabetes. We tested whether sleeve gastrectomy (SG), a common bariatric surgery, can affect the cognitive impairment in lean, normoglycemic female 5xFAD mice, a genetic model for AD. 5xFAD mice and wild-type (WT) littermates underwent SG or sham surgery at the age of 5 months and were tested for metabolic, behavioral, and molecular phenotypes 90 days later. SG led to a reduction in blood glucose levels and total plasma cholesterol levels in 5xFAD mice without inducing weight loss. However, the surgery did not affect the outcomes of long-term spatial memory tests in these mice. Analysis of β-Amyloid plaques corroborated the behavioral studies in showing no effect of surgery on the molecular phenotype of 5xFAD mice. In conclusion, SG leads to an improved metabolic profile in lean female 5xFAD mice without inducing weight loss but does not affect the brain pathology or behavioral phenotype. Our results suggest that the positive effects of bariatric surgery on cognitive decline in obese patients are likely attributed to weight loss and improvement in obesity sequelae, and not to weight loss independent effects of surgery.
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Affiliation(s)
- Itia Samuel
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Rachel Ben-Haroush Schyr
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Yhara Arad
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
- Department of Military Medicine and Tzameret, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tamar Attali
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Shira Azulai
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Michael Bergel
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Aviv Halfon
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
- Department of Military Medicine and Tzameret, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Liron Hefetz
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
- Department of Military Medicine and Tzameret, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tamir Hirsch
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel
- The Paul Feder Laboratory on Alzheimer’s Disease Research, Bar-Ilan University, Ramat Gan, Israel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Hadar Israeli
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Neta Lax
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Keren Nitzan
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Dana Sender
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Sahar Sweetat
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Eitan Okun
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel
- The Paul Feder Laboratory on Alzheimer’s Disease Research, Bar-Ilan University, Ramat Gan, Israel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Hanna Rosenmann
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
- *Correspondence: Hanna Rosenmann,
| | - Danny Ben-Zvi
- Department of Developmental Biology and Cancer Research, The Institute of Medical Research Israel-Canada, The Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
- Danny Ben-Zvi,
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Kakhlon O, Vaknin H, Mishra K, D’Souza J, Marisat M, Sprecher U, Wald‐Altman S, Dukhovny A, Raviv Y, Da’adoosh B, Engel H, Benhamron S, Nitzan K, Sweetat S, Permyakova A, Mordechai A, Akman HO, Rosenmann H, Lossos A, Tam J, Minassian BA, Weil M. Alleviation of a polyglucosan storage disorder by enhancement of autophagic glycogen catabolism. EMBO Mol Med 2021; 13:e14554. [PMID: 34486811 PMCID: PMC8495453 DOI: 10.15252/emmm.202114554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 05/13/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 11/09/2022] Open
Abstract
This work employs adult polyglucosan body disease (APBD) models to explore the efficacy and mechanism of action of the polyglucosan-reducing compound 144DG11. APBD is a glycogen storage disorder (GSD) caused by glycogen branching enzyme (GBE) deficiency causing accumulation of poorly branched glycogen inclusions called polyglucosans. 144DG11 improved survival and motor parameters in a GBE knockin (Gbeys/ys ) APBD mouse model. 144DG11 reduced polyglucosan and glycogen in brain, liver, heart, and peripheral nerve. Indirect calorimetry experiments revealed that 144DG11 increases carbohydrate burn at the expense of fat burn, suggesting metabolic mobilization of pathogenic polyglucosan. At the cellular level, 144DG11 increased glycolytic, mitochondrial, and total ATP production. The molecular target of 144DG11 is the lysosomal membrane protein LAMP1, whose interaction with the compound, similar to LAMP1 knockdown, enhanced autolysosomal degradation of glycogen and lysosomal acidification. 144DG11 also enhanced mitochondrial activity and modulated lysosomal features as revealed by bioenergetic, image-based phenotyping and proteomics analyses. As an effective lysosomal targeting therapy in a GSD model, 144DG11 could be developed into a safe and efficacious glycogen and lysosomal storage disease therapy.
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Affiliation(s)
- Or Kakhlon
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Hilla Vaknin
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
| | - Kumudesh Mishra
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Jeevitha D’Souza
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
| | - Monzer Marisat
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
| | - Uri Sprecher
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
| | - Shane Wald‐Altman
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
| | - Anna Dukhovny
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
| | - Yuval Raviv
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
| | - Benny Da’adoosh
- Blavatnik Center for Drug DiscoveryTel Aviv UniversityTel AvivIsrael
| | - Hamutal Engel
- Blavatnik Center for Drug DiscoveryTel Aviv UniversityTel AvivIsrael
| | - Sandrine Benhamron
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
- Hadassah BrainLabs – National Knowledge Center for Research on Brain DiseasesHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Keren Nitzan
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
- Hadassah BrainLabs – National Knowledge Center for Research on Brain DiseasesHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Sahar Sweetat
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
- Hadassah BrainLabs – National Knowledge Center for Research on Brain DiseasesHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Anna Permyakova
- Obesity and Metabolism LaboratoryInstitute for Drug ResearchSchool of PharmacyFaculty of MedicineThe Hebrew University of JerusalemJerusalemIsrael
| | - Anat Mordechai
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Hasan Orhan Akman
- Department of NeurologyColumbia University Medical CenterNew YorkNew YorkUSA
| | - Hanna Rosenmann
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
- Hadassah BrainLabs – National Knowledge Center for Research on Brain DiseasesHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Alexander Lossos
- Department of NeurologyHadassah‐Hebrew University Medical CenterJerusalemIsrael
| | - Joseph Tam
- Obesity and Metabolism LaboratoryInstitute for Drug ResearchSchool of PharmacyFaculty of MedicineThe Hebrew University of JerusalemJerusalemIsrael
| | - Berge A. Minassian
- Division of NeurologyDepartment of PediatricsUniversity of Texas Southwestern Medical CenterDallasTXUSA
| | - Miguel Weil
- Laboratory for Neurodegenerative Diseases and Personalized MedicineThe Cell Screening Facility for Personalized MedicineThe Shmunis School of Biomedicine and Cancer ResearchThe George S. Wise Faculty for Life SciencesSagol School of NeurosciencesTel Aviv UniversityTel AvivIsrael
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Birger A, Ben-Dor I, Ottolenghi M, Turetsky T, Gil Y, Sweetat S, Perez L, Belzer V, Casden N, Steiner D, Izrael M, Galun E, Feldman E, Behar O, Reubinoff B. Human iPSC-derived astrocytes from ALS patients with mutated C9ORF72 show increased oxidative stress and neurotoxicity. EBioMedicine 2019; 50:274-289. [PMID: 31787569 PMCID: PMC6921360 DOI: 10.1016/j.ebiom.2019.11.026] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [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: 07/26/2019] [Revised: 10/24/2019] [Accepted: 11/18/2019] [Indexed: 12/12/2022] Open
Abstract
Background Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects motor neurons (MNs). It was shown that human astrocytes with mutations in genes associated with ALS, like C9orf72 (C9) or SOD1, reduce survival of MNs. Astrocyte toxicity may be related to their dysfunction or the release of neurotoxic factors. Methods We used human induced pluripotent stem cell-derived astrocytes from ALS patients carrying C9orf72 mutations and non-affected donors. We utilized these cells to investigate astrocytic induced neuronal toxicity, changes in astrocyte transcription profile as well as changes in secretome profiles. Findings We report that C9-mutated astrocytes are toxic to MNs via soluble factors. The toxic effects of astrocytes are positively correlated with the length of astrocyte propagation in culture, consistent with the age-related nature of ALS. We show that C9-mutated astrocytes downregulate the secretion of several antioxidant proteins. In line with these findings, we show increased astrocytic oxidative stress and senescence. Importantly, media conditioned by C9-astrocytes increased oxidative stress in wild type MNs. Interpretation Our results suggest that dysfunction of C9-astrocytes leads to oxidative stress of themselves and MNs, which probably contributes to neurodegeneration. Our findings suggest that therapeutic strategies in familial ALS must not only target MNs but also focus on astrocytes to abrogate nervous system injury.
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Affiliation(s)
- Anastasya Birger
- The Sidney and Judy Swartz Embryonic Stem Cell Research Center of The Goldyne Savad Institute of Gene Therapy & The Department of Obstetrics & Gynecology, Hadassah University Medical Center, Jerusalem 91120, Israel; Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel
| | - Israel Ben-Dor
- The Sidney and Judy Swartz Embryonic Stem Cell Research Center of The Goldyne Savad Institute of Gene Therapy & The Department of Obstetrics & Gynecology, Hadassah University Medical Center, Jerusalem 91120, Israel
| | - Miri Ottolenghi
- The Sidney and Judy Swartz Embryonic Stem Cell Research Center of The Goldyne Savad Institute of Gene Therapy & The Department of Obstetrics & Gynecology, Hadassah University Medical Center, Jerusalem 91120, Israel
| | - Tikva Turetsky
- The Sidney and Judy Swartz Embryonic Stem Cell Research Center of The Goldyne Savad Institute of Gene Therapy & The Department of Obstetrics & Gynecology, Hadassah University Medical Center, Jerusalem 91120, Israel
| | - Yaniv Gil
- The Sidney and Judy Swartz Embryonic Stem Cell Research Center of The Goldyne Savad Institute of Gene Therapy & The Department of Obstetrics & Gynecology, Hadassah University Medical Center, Jerusalem 91120, Israel
| | - Sahar Sweetat
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel
| | - Liat Perez
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel
| | - Vitali Belzer
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel
| | - Natania Casden
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel
| | - Debora Steiner
- The Sidney and Judy Swartz Embryonic Stem Cell Research Center of The Goldyne Savad Institute of Gene Therapy & The Department of Obstetrics & Gynecology, Hadassah University Medical Center, Jerusalem 91120, Israel
| | - Michal Izrael
- Kadimastem Ltd., Sapir 7, Weizmann Science Park, Nes-Ziona, Israel
| | - Eithan Galun
- The Goldyne Savad Institute of Gene Therapy, Hadassah University Medical Center, Jerusalem 91120, Israel
| | - Eva Feldman
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Oded Behar
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel.
| | - Benjamin Reubinoff
- The Sidney and Judy Swartz Embryonic Stem Cell Research Center of The Goldyne Savad Institute of Gene Therapy & The Department of Obstetrics & Gynecology, Hadassah University Medical Center, Jerusalem 91120, Israel.
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Maimon R, Ionescu A, Bonnie A, Sweetat S, Wald-Altman S, Gradus T, Weil M, Behar O, Trotti D, Perlson E. Muscles secretion of toxic factors regulated by miR126-5P facilitate motor neuron degeneration in ALS. J Neurol Sci 2017. [DOI: 10.1016/j.jns.2017.08.2295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gal-Mark N, Shallev L, Sweetat S, Barak M, Billy Li J, Levanon EY, Eisenberg E, Behar O. Abnormalities in A-to-I RNA editing patterns in CNS injuries correlate with dynamic changes in cell type composition. Sci Rep 2017; 7:43421. [PMID: 28266523 PMCID: PMC5339895 DOI: 10.1038/srep43421] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/24/2017] [Indexed: 11/10/2022] Open
Abstract
Adenosine to Inosine (A-to-I) RNA editing is a co- or post-transcriptional mechanism that modifies genomically encoded nucleotides at the RNA level. A-to-I RNA editing is abundant in the brain, and altered editing levels have been reported in various neurological pathologies and following spinal cord injury (SCI). The prevailing concept is that the RNA editing process itself is dysregulated by brain pathologies. Here we analyzed recent RNA-seq data, and found that, except for few mammalian conserved editing sites, editing is significantly higher in neurons than in other cell populations of the brain. We studied A-to-I RNA editing in stab wound injury (SWI) and SCI models and showed that the apparent under-editing observed after injury correlates with an approximately 20% reduction in the relative density of neurons, due to cell death and immune cell infiltration that may account for the observed under-editing. Studies of neuronal and astrocyte cultures and a computational analysis of SCI RNA-seq data further supported the possibility that a reduction in neuronal density is responsible for alterations in the tissue-wide editing patterns upon injury. Thus, our data suggest that the case for a mechanistic linkage between A-to-I RNA editing and brain pathologies should be revisited.
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Affiliation(s)
- Nurit Gal-Mark
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Lea Shallev
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Sahar Sweetat
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel
| | - Michal Barak
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Erez Y Levanon
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Eli Eisenberg
- Raymond and Beverly Sackler School of Physics and Astronomy and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Oded Behar
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, Jerusalem 91120, Israel
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Ben-Zvi A, Sweetat S, Behar O. Elimination of aberrant DRG circuitries in Sema3A mutant mice leads to extensive neuronal deficits. PLoS One 2013; 8:e70085. [PMID: 23922915 PMCID: PMC3724818 DOI: 10.1371/journal.pone.0070085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 06/17/2013] [Indexed: 01/19/2023] Open
Abstract
Axon guidance molecules determine the pattern of neuronal circuits. Accuracy of the process is ensured by unknown mechanisms that correct early guidance errors. Since the time frame of error correction in Sema3A null mice partly overlaps with the period of naturally occurring cell death in dorsal root ganglia (DRG) development, we tested the hypothesis that apoptosis of misguided neurons enables error correction. We crossed BAX null mice, in which DRG apoptosis is blocked, with Sema3A null mice to induce errors. Analyses of these double-null mouse embryos showed that the elimination of abnormal projections is not blocked in the absence of BAX. Surprisingly however, there are fewer surviving neurons in Sema3A null or Sema3A/BAX double-null newborn mice than in wild-type mice. These results suggest that guidance errors are corrected by a BAX-independent cell death mechanism. Thus, aberrant axonal guidance may lead to reductions in neuronal numbers to suboptimal levels, perhaps increasing the likelihood of neuropathological consequences later in life.
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Affiliation(s)
- Ayal Ben-Zvi
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Sahar Sweetat
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Oded Behar
- Department of Developmental Biology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel
- * E-mail:
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