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Palzkill VR, Tan J, Tice AL, Ferriera LF, Ryan TE. A 6-minute Limb Function Assessment for Therapeutic Testing in Experimental Peripheral Artery Disease Models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.21.586197. [PMID: 38585832 PMCID: PMC10996543 DOI: 10.1101/2024.03.21.586197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Background The translation of promising therapies from pre-clinical models of hindlimb ischemia (HLI) to patients with peripheral artery disease (PAD) has been inadequate. While this failure is multifactorial, primary outcome measures in preclinical HLI models and clinical trials involving patients with PAD are not aligned well. For example, laser Doppler perfusion recovery measured under resting conditions is the most used outcome in HLI studies, whereas clinical trials involving patients with PAD primarily assess walking performance. Here, we sought to develop a 6-min limb function test for preclinical HLI models that assess muscular performance and hemodynamics congruently. Methods We developed an in situ 6-min limb function test that involves repeated isotonic (shortening) contractions performed against a submaximal load. Continuous measurement of muscle blood flow was performed using laser Doppler flowmetry. Quantification of muscle power, work, and perfusion are obtained across the test. To assess the efficacy of this test, we performed HLI via femoral artery ligation on several mouse strains: C57BL6J, BALBc/J, and MCK-PGC1α (muscle-specific overexpression of PGC1α). Additional experiments were performed using an exercise intervention (voluntary wheel running) following HLI. Results The 6-min limb function test was successful at detecting differences in limb function of C57BL6/J and BALBc/J mice subjected to HLI with effect sizes superior to laser Doppler perfusion recovery. C57BL6/J mice randomized to exercise therapy following HLI had smaller decline in muscle power, greater hyperemia, and performed more work across the 6-min limb function test compared to non-exercise controls with HLI. Mice with muscle-specific overexpression of PGC1α had no differences in perfusion recovery in resting conditions, but exhibited greater capillary density, increased muscle mass and absolute force levels, and performed more work across the 6-min limb function test compared to their wildtype littermates without the transgene. Conclusion These results demonstrate the efficacy of the 6-min limb function test to detect differences in the response to HLI across several interventions including where traditional perfusion recovery, capillary density, and muscle strength measures were unable to detect therapeutic differences.
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Affiliation(s)
- Victoria R. Palzkill
- Department of Applied Physiology and Kinesiology, The University of Florida, Gainesville, FL, USA
| | - Jianna Tan
- Department of Applied Physiology and Kinesiology, The University of Florida, Gainesville, FL, USA
| | | | - Leonardo F. Ferriera
- Department of Applied Physiology and Kinesiology, The University of Florida, Gainesville, FL, USA
- Center for Exercise Science, The University of Florida, Gainesville, FL, USA
- The Myology Institute, The University of Florida, Gainesville, FL, USA
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, USA
| | - Terence E. Ryan
- Department of Applied Physiology and Kinesiology, The University of Florida, Gainesville, FL, USA
- Center for Exercise Science, The University of Florida, Gainesville, FL, USA
- The Myology Institute, The University of Florida, Gainesville, FL, USA
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2
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Sun X, Yang Y, Zhao W, Wang M, Chen Y, Wang J, Yang D, Yang Y. MTMR7 suppresses the phenotypic switching of vascular smooth muscle cell and vascular intimal hyperplasia after injury via regulating p62/mTORC1-mediated glucose metabolism. Atherosclerosis 2024; 390:117470. [PMID: 38342025 DOI: 10.1016/j.atherosclerosis.2024.117470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 12/24/2023] [Accepted: 01/30/2024] [Indexed: 02/13/2024]
Abstract
BACKGROUND AND AIMS Myotubularin-related protein 7 (MTMR7) suppresses proliferation in various cell types and is associated with cardiovascular and cerebrovascular diseases. However, whether MTMR7 regulates vascular smooth muscle cell (VSMC) and vascular intimal hyperplasia remains unclear. We explored the role of MTMR7 in phenotypic switching of VSMC and vascular intimal hyperplasia after injury. METHODS AND RESULTS MTMR7 expression was significantly downregulated in injured arteries. Compared to wild type (WT) mice, Mtmr7-transgenic (Mtmr7-Tg) mice showed reduced intima/media ratio, decreased percentage of Ki-67-positive cells within neointima, and increased Calponin expression in injured artery. In vitro, upregulating MTMR7 by Len-Mtmr7 transfection inhibited platelet derived growth factor (PDGF)-BB-induced proliferation, migration of VSMC and reversed PDGF-BB-induced decrease in expression of Calponin and SM-MHC. Microarray, single cell sequence, and other bioinformatics analysis revealed that MTMR7 is highly related to glucose metabolism and mammalian target of rapamycin complex 1 (mTORC1). Further experiments confirmed that MTMR7 markedly repressed glycolysis and mTORC1 activity in PDGF-BB-challenged VSMC in vitro. Restoring mTORC1 activity abolished MTMR7-mediated suppression of glycolysis, phenotypic shift in VSMC in vitro and protection against vascular intimal hyperplasia in vivo. Furthermore, upregulating MTMR7 in vitro led to dephosphorylation and dissociation of p62 from mTORC1 in VSMC. External expression of p62 in vitro also abrogated the inhibitory effects of MTMR7 on glycolysis and phenotypic switching in PDGF-BB-stimulated VSMC. CONCLUSIONS Our study demonstrates that MTMR7 inhibits injury-induced vascular intimal hyperplasia and phenotypic switching of VSMC. Mechanistically, the beneficial effects of MTMR7 are conducted via suppressing p62/mTORC1-mediated glycolysis.
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Affiliation(s)
- Xiongshan Sun
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Yao Yang
- From the Department of Pharmacy, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Weiwei Zhao
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Mingliang Wang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Yingmei Chen
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Jia Wang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Dachun Yang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China.
| | - Yongjian Yang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China.
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3
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Lee HK, Kwon DH, Aylor DL, Marchuk DA. A cross-species approach using an in vivo evaluation platform in mice demonstrates that sequence variation in human RABEP2 modulates ischemic stroke outcomes. Am J Hum Genet 2022; 109:1814-1827. [PMID: 36167069 PMCID: PMC9606478 DOI: 10.1016/j.ajhg.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 09/01/2022] [Indexed: 01/25/2023] Open
Abstract
Ischemic stroke, caused by vessel blockage, results in cerebral infarction, the death of brain tissue. Previously, quantitative trait locus (QTL) mapping of cerebral infarct volume and collateral vessel number identified a single, strong genetic locus regulating both phenotypes. Additional studies identified RAB GTPase-binding effector protein 2 (Rabep2) as the casual gene. However, there is yet no evidence that variation in the human ortholog of this gene plays any role in ischemic stroke outcomes. We established an in vivo evaluation platform in mice by using adeno-associated virus (AAV) gene replacement and verified that both mouse and human RABEP2 rescue the mouse Rabep2 knockout ischemic stroke volume and collateral vessel phenotypes. Importantly, this cross-species complementation enabled us to experimentally investigate the functional effects of coding sequence variation in human RABEP2. We chose four coding variants from the human population that are predicted by multiple in silico algorithms to be damaging to RABEP2 function. In vitro and in vivo analyses verify that all four led to decreased collateral vessel connections and increased infarct volume. Thus, there are naturally occurring loss-of-function alleles. This cross-species approach will expand the number of targets for therapeutics development for ischemic stroke.
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Affiliation(s)
- Han Kyu Lee
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA.
| | - Do Hoon Kwon
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - David L Aylor
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Douglas A Marchuk
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA.
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4
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Lee HK, Wetzel-Strong SE, Aylor DL, Marchuk DA. A Neuroprotective Locus Modulates Ischemic Stroke Infarction Independent of Collateral Vessel Anatomy. Front Neurosci 2021; 15:705160. [PMID: 34408625 PMCID: PMC8366065 DOI: 10.3389/fnins.2021.705160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/01/2021] [Indexed: 11/13/2022] Open
Abstract
Although studies with inbred strains of mice have shown that infarct size is largely determined by the extent of collateral vessel connections between arteries in the brain that enable reperfusion of the ischemic territory, we have identified strain pairs that do not vary in this vascular phenotype, but which nonetheless exhibit large differences in infarct size. In this study we performed quantitative trait locus (QTL) mapping in mice from an intercross between two such strains, WSB/EiJ (WSB) and C57BL/6J (B6). This QTL mapping revealed only one neuroprotective locus on Chromosome 8 (Chr 8) that co-localizes with a neuroprotective locus we mapped previously from F2 progeny between C3H/HeJ (C3H) and B6. The allele-specific phenotypic effect on infarct volume at the genetic region identified by these two independent mappings was in the opposite direction of the parental strain phenotype; namely, the B6 allele conferred increased susceptibility to ischemic infarction. Through two reciprocal congenic mouse lines with either the C3H or B6 background at the Chr 8 locus, we verified the neuroprotective effects of this genetic region that modulates infarct volume without any effect on the collateral vasculature. Additionally, we surveyed non-synonymous coding SNPs and performed RNA-sequencing analysis to identify potential candidate genes within the genetic interval. Through these approaches, we suggest new genes for future mechanistic studies of infarction following ischemic stroke, which may represent novel gene/protein targets for therapeutic development.
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Affiliation(s)
- Han Kyu Lee
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Sarah E. Wetzel-Strong
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - David L. Aylor
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States
| | - Douglas A. Marchuk
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
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5
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Kanoke A, Akamatsu Y, Nishijima Y, To E, Lee CC, Li Y, Wang RK, Tominaga T, Liu J. The impact of native leptomeningeal collateralization on rapid blood flow recruitment following ischemic stroke. J Cereb Blood Flow Metab 2020; 40:2165-2178. [PMID: 32669022 PMCID: PMC7585920 DOI: 10.1177/0271678x20941265] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The leptomeningeal collateral status is an independent predictor of stroke outcome. By means of optical coherent tomography angiography to compare two mouse strains with different extent of native leptomeningeal collateralization, we determined the spatiotemporal dynamics of collateral flow and downstream hemodynamics following ischemic stroke. A robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, with continued expansion over the course of seven days. In contrast, little collateral recruitment was seen in Balb/C mice during- and one day after MCAO, which coincided with a greater infarct size and worse functional outcome compared to C57BL/6, despite a slight improvement of cortical perfusion seven days after MCAO. Both strains of mice experienced a reduction of blood flow in the penetrating arterioles (PA) by more than 90% 30-min after dMCAO, although the decrease of PA flow was greater and the recovery was less in the Balb/C mice. Further, Balb/C mice also displayed a prolonged greater heterogeneity of capillary transit time after dMCAO in the MCA territory compared to C57BL/6 mice. Our data suggest that the extent of native leptomeningeal collaterals affects downstream hemodynamics with a long lasting impact in the microvascular bed after cortical stroke.
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Affiliation(s)
- Atsushi Kanoke
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.,SFVAMC, San Francisco, CA, USA.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yosuke Akamatsu
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.,SFVAMC, San Francisco, CA, USA.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yasuo Nishijima
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.,SFVAMC, San Francisco, CA, USA.,Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Eric To
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.,SFVAMC, San Francisco, CA, USA
| | - Chih C Lee
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.,SFVAMC, San Francisco, CA, USA
| | - Yuandong Li
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA
| | - Ruikang K Wang
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Jialing Liu
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA.,SFVAMC, San Francisco, CA, USA
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6
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Lee HK, Widmayer SJ, Huang MN, Aylor DL, Marchuk DA. Novel Neuroprotective Loci Modulating Ischemic Stroke Volume in Wild-Derived Inbred Mouse Strains. Genetics 2019; 213:1079-1092. [PMID: 31488517 PMCID: PMC6827375 DOI: 10.1534/genetics.119.302555] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 08/30/2019] [Indexed: 11/18/2022] Open
Abstract
To identify genes involved in cerebral infarction, we have employed a forward genetic approach in inbred mouse strains, using quantitative trait loci (QTL) mapping for cerebral infarct volume after middle cerebral artery occlusion. We had previously observed that infarct volume is inversely correlated with cerebral collateral vessel density in most strains. In this study, we expanded the pool of allelic variation among classical inbred mouse strains by utilizing the eight founder strains of the Collaborative Cross and found a wild-derived strain, WSB/EiJ, that breaks this general rule that collateral vessel density inversely correlates with infarct volume. WSB/EiJ and another wild-derived strain, CAST/EiJ, show the highest collateral vessel densities of any inbred strain, but infarct volume of WSB/EiJ mice is 8.7-fold larger than that of CAST/EiJ mice. QTL mapping between these strains identified four new neuroprotective loci modulating cerebral infarct volume while not affecting collateral vessel phenotypes. To identify causative variants in genes, we surveyed nonsynonymous coding SNPs between CAST/EiJ and WSB/EiJ and found 96 genes harboring coding SNPs predicted to be damaging and mapping within one of the four intervals. In addition, we performed RNA-sequencing for brain tissue of CAST/EiJ and WSB/EiJ mice and identified 79 candidate genes mapping in one of the four intervals showing strain-specific differences in expression. The identification of the genes underlying these neuroprotective loci will provide new understanding of genetic risk factors of ischemic stroke, which may provide novel targets for future therapeutic intervention of human ischemic stroke.
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Affiliation(s)
- Han Kyu Lee
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Samuel J Widmayer
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Min-Nung Huang
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710
| | - David L Aylor
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Douglas A Marchuk
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
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7
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Chen M, Lyu H, Li T, Su XW, Leung CK, Xiong MZQ, Poon WS, Cai YF, Lu G, Chan WY, Wang LX. Study of the association between gait variability and gene expressions in a mouse model of transient focal ischemic stroke. Int J Neurosci 2019; 130:52-63. [PMID: 31512542 DOI: 10.1080/00207454.2019.1663188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Purpose: Gait variability analysis has been clinically adopted to characterize the presentation of various neurological diseases. However, literature and practice lack a comprehensive murine model assessment of the gait deficits that result from transient focal ischemic stroke. Further, correlations between gait parameters and the gene expression profiles associated with brain ischemia have yet to be identified. This study quantitatively assesses gait deficits through a murine model of transient focal cerebral ischemia on day 7 to determine associations between gait deficits and ischemia-related gene expressions.Methods: A total of 182 dynamic and static gait parameters from the transient middle cerebral artery occlusion (MCAO) murine model for simulating human transient focal ischemic stroke on day 7 were measured using the CatWalk system. Pearson's correlation analysis and genes associated with ischemia were identified from the existing literature to aid the investigation of the relationship between gait variability and gene expression profiles.Results: Thirty-nine gait parameters and the mRNA expression levels of four of the eight ischemia-associated genes exhibited more significant change in the MCAO models (p < 0.005) on day 7. Twenty-six gait parameters exhibited strong correlations with four ischemia-associated genes.Conclusion: This examination of gait variability and the strong correlation to the gene expression profiles associated with transient focal brain ischemia on day 7 provides a quantitative and reliable assessment of the MCAO model's motor performance. This research provides valuable insights into the study of disease progression and offers novel therapeutic interventions in the murine modeling of ischemic stroke.
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Affiliation(s)
- Mei Chen
- Neurology Department, The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guang Zhou, China.,CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Hao Lyu
- Division of Neurosurgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Tu Li
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Xian Wei Su
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Chi Kwan Leung
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Mark Zhi Qiang Xiong
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Wai Sang Poon
- Division of Neurosurgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Ye-Feng Cai
- Neurology Department, The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guang Zhou, China
| | - Gang Lu
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.,Ningxia Human Stem Cell Institute, The General Hospital of Ningxia Medical University, Yinchuan, China
| | - Wai-Yee Chan
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Li-Xin Wang
- Neurology Department, The Second Clinical Medical College, Guangzhou University of Chinese Medicine, Guang Zhou, China
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8
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Rudy RF, Charoenvimolphan N, Qian B, Berndt A, Friedlander RM, Weiss ST, Du R. A Genome-Wide Analysis of the Penumbral Volume in Inbred Mice following Middle Cerebral Artery Occlusion. Sci Rep 2019; 9:5070. [PMID: 30911049 PMCID: PMC6433893 DOI: 10.1038/s41598-019-41592-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 03/12/2019] [Indexed: 12/26/2022] Open
Abstract
Following ischemic stroke, the penumbra, at-risk neural tissue surrounding the core infarct, survives for a variable period of time before progressing to infarction. We investigated genetic determinants of the size of penumbra in mice subjected to middle cerebral artery occlusion (MCAO) using a genome-wide approach. 449 male mice from 33 inbred strains underwent MCAO for 6 hours (215 mice) or 24 hours (234 mice). A genome-wide association study using genetic data from the Mouse HapMap project was performed to examine the effects of genetic variants on the penumbra ratio, defined as the ratio of the infarct volume after 6 hours to the infarct volume after 24 hours of MCAO. Efficient mixed model analysis was used to account for strain interrelatedness. Penumbra ratio differed significantly by strain (F = 2.7, P < 0.001) and was associated with 18 significant SNPs, including 6 protein coding genes. We have identified 6 candidate genes for penumbra ratio: Clint1, Nbea, Smtnl2, Rin3, Dclk1, and Slc24a4.
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Affiliation(s)
- Robert F Rudy
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | | | - Baogang Qian
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Annerose Berndt
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Robert M Friedlander
- Department of Neurosurgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Scott T Weiss
- Harvard Medical School, Boston, Massachusetts, USA.,Channing Division of Network Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Rose Du
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA. .,Harvard Medical School, Boston, Massachusetts, USA. .,Channing Division of Network Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.
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9
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Vilanilam G, Badi M, Gopal N. Letter by Vilanilam et al Regarding Article, "Collateral Clock Is More Important Than Time Clock for Tissue Fate: A Natural History Study of Acute Ischemic Strokes". Stroke 2018; 49:e339. [PMID: 30571443 DOI: 10.1161/strokeaha.118.023379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
| | - Mohammed Badi
- Department of Neurology, Mayo Clinic, Jacksonville, FL
| | - Neethu Gopal
- Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL
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10
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Kelley KW, Nakao-Inoue H, Molofsky AV, Oldham MC. Variation among intact tissue samples reveals the core transcriptional features of human CNS cell classes. Nat Neurosci 2018; 21:1171-1184. [PMID: 30154505 PMCID: PMC6192711 DOI: 10.1038/s41593-018-0216-z] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/10/2018] [Indexed: 02/08/2023]
Abstract
It is widely assumed that cells must be physically isolated to study their molecular profiles. However, intact tissue samples naturally exhibit variation in cellular composition, which drives covariation of cell-class-specific molecular features. By analyzing transcriptional covariation in 7,221 intact CNS samples from 840 neurotypical individuals, representing billions of cells, we reveal the core transcriptional identities of major CNS cell classes in humans. By modeling intact CNS transcriptomes as a function of variation in cellular composition, we identify cell-class-specific transcriptional differences in Alzheimer's disease, among brain regions, and between species. Among these, we show that PMP2 is expressed by human but not mouse astrocytes and significantly increases mouse astrocyte size upon ectopic expression in vivo, causing them to more closely resemble their human counterparts. Our work is available as an online resource ( http://oldhamlab.ctec.ucsf.edu/ ) and provides a generalizable strategy for determining the core molecular features of cellular identity in intact biological systems.
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Affiliation(s)
- Kevin W Kelley
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA, USA
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California at San Francisco, San Francisco, CA, USA
- Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, USA
- Department of Psychiatry, University of California at San Francisco, San Francisco, CA, USA
- Medical Scientist Training Program and Neuroscience Graduate Program, University of California at San Francisco, San Francisco, CA, USA
| | - Hiromi Nakao-Inoue
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California at San Francisco, San Francisco, CA, USA
- Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, USA
- Department of Psychiatry, University of California at San Francisco, San Francisco, CA, USA
| | - Anna V Molofsky
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California at San Francisco, San Francisco, CA, USA
- Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, USA
- Department of Psychiatry, University of California at San Francisco, San Francisco, CA, USA
| | - Michael C Oldham
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA, USA.
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California at San Francisco, San Francisco, CA, USA.
- Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, USA.
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11
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Lee HK, Koh S, Lo DC, Marchuk DA. Neuronal IL-4Rα modulates neuronal apoptosis and cell viability during the acute phases of cerebral ischemia. FEBS J 2018; 285:2785-2798. [PMID: 29756681 DOI: 10.1111/febs.14498] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/15/2018] [Accepted: 05/02/2018] [Indexed: 12/21/2022]
Abstract
Ischemic stroke caused by an embolus or local thrombosis results in neural tissue damage (an infarct) in the territory of the occluded cerebral artery. Decades of studies have increased our understanding of the molecular events during cerebral infarction; however, translation of these discoveries to druggable targets for ischemic stroke treatment has been largely disappointing. Interleukin-4 (IL-4) is a multifunctional cytokine that exerts its cellular activities via the interleukin-4 receptor α (IL-4Rα). This cytokine receptor complex is associated with diverse immune and inflammatory responses. Recent studies have suggested a role of the cytokine IL-4 in long-term ischemic stroke recovery, involving immune cell activity. In contrast, the role of the receptor, IL-4Rα especially in the acute phase of infarction is unclear. In this study, we determined that IL-4Rα is expressed on neurons and that during the early phases of cerebral infarction (24 h) levels of this receptor are increased to regulate cellular apoptosis factors through activation of STAT6. In this context, we show a neuroprotective role for IL-4Rα in an in vivo surgical model of cerebral ischemia and in ex vivo brain slice explants, using both genetic knockout of this receptor and RNAi-mediated gene knockdown. IL-4Rα may therefore represent a novel target and pathway for therapeutic development in ischemic stroke.
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Affiliation(s)
- Han Kyu Lee
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Sehwon Koh
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA
| | - Donald C Lo
- Center for Drug Discovery and Department of Neurobiology, Duke University Medical Center, Durham, NC, USA
| | - Douglas A Marchuk
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
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12
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D'Abbondanza JA, Ai J, Lass E, Wan H, Brathwaite S, Tso MK, Lee C, Marsden PA, Macdonald RL. Robust effects of genetic background on responses to subarachnoid hemorrhage in mice. J Cereb Blood Flow Metab 2016; 36:1942-1954. [PMID: 26661216 PMCID: PMC5094306 DOI: 10.1177/0271678x15612489] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/08/2015] [Indexed: 01/08/2023]
Abstract
Outcome varies among patients with subarachnoid hemorrhage but known prognostic factors explain only a small portion of the variation in outcome. We hypothesized that individual genetic variations influence brain and vascular responses to subarachnoid hemorrhage and investigated this using inbred strains of mice.Subarachnoid hemorrhage was induced in seven inbred and a chromosome 7 substitution strain of mouse. Cerebral blood flow, vasospasm of the middle cerebral artery, and brain injury were assessed. After 48 h of subarachnoid hemorrhage, mice showed significant middle cerebral artery vasospasm that correlated positively with reduction in cerebral blood flow at 45 min. Mice also had increased neuronal injury compared to sham controls; A/J and C57BL/6 J strains represented the most and least severe, respectively. However, brain injury did not correlate with cerebral blood flow reduction at 45 min or with vasospasm at 48 h. Chromosome 7 substitution did not influence the degree of vasospasm or brain injury.Our data suggested that mouse genetic background influences outcome of subarachnoid hemorrhage. Investigations into the genetic factors causing these inter-strain differences may provide insight into the etiology of the brain damage following subarachnoid hemorrhage. These findings also have implications for animal modeling of disease and suggest that genetic differences may also modulate outcome in other cardiovascular diseases.
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Affiliation(s)
- Josephine A D'Abbondanza
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada.,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Jinglu Ai
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada.,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada
| | - Elliot Lass
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada.,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada
| | - Hoyee Wan
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada.,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada
| | - Shakira Brathwaite
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada.,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Michael K Tso
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada.,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Charles Lee
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada.,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada
| | - Philip A Marsden
- Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - R Loch Macdonald
- Division of Neurosurgery, St. Michael's Hospital, Toronto, ON, Canada .,Labatt Family Centre of Excellence in Brain Injury and Trauma Research, St. Michael's Hospital, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science and the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada
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13
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Ginsberg MD. Expanding the concept of neuroprotection for acute ischemic stroke: The pivotal roles of reperfusion and the collateral circulation. Prog Neurobiol 2016; 145-146:46-77. [PMID: 27637159 DOI: 10.1016/j.pneurobio.2016.09.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/22/2016] [Accepted: 09/10/2016] [Indexed: 12/27/2022]
Abstract
This review surveys the efforts taken to achieve clinically efficacious protection of the ischemic brain and underscores the necessity of expanding our purview to include the essential role of cerebral perfusion and the collateral circulation. We consider the development of quantitative strategies to measure cerebral perfusion at the regional and local levels and the application of these methods to elucidate flow-related thresholds of ischemic viability and to characterize the ischemic penumbra. We stress that the modern concept of neuroprotection must consider perfusion, the necessary substrate upon which ischemic brain survival depends. We survey the major mechanistic approaches to neuroprotection and review clinical neuroprotection trials, focusing on those phase 3 multicenter clinical trials for acute ischemic stroke that have been completed or terminated. We review the evolution of thrombolytic therapies; consider the lessons learned from the initial, negative multicenter trials of endovascular therapy; and emphasize the highly successful positive trials that have finally established a clinical role for endovascular clot removal. As these studies point to the brain's collateral circulation as key to successful reperfusion, we next review the anatomy and pathophysiology of collateral perfusion as it relates to ischemic infarction, as well as the molecular and genetic influences on collateral development. We discuss the current MR and CT-based diagnostic methods for assessing the collateral circulation and the prognostic significance of collaterals in ischemic stroke, and we consider past and possible future therapeutic directions.
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Affiliation(s)
- Myron D Ginsberg
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States.
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14
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Kent TA, Mandava P. Embracing Biological and Methodological Variance in a New Approach to Pre-Clinical Stroke Testing. Transl Stroke Res 2016; 7:274-83. [PMID: 27018014 PMCID: PMC5425098 DOI: 10.1007/s12975-016-0463-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/08/2016] [Accepted: 03/15/2016] [Indexed: 12/12/2022]
Abstract
High-profile failures in stroke clinical trials have discouraged clinical translation of neuroprotectants. While there are several plausible explanations for these failures, we believe that the fundamental problem is the way clinical and pre-clinical studies are designed and analyzed for heterogeneous disorders such as stroke due to innate biological and methodological variability that current methods cannot capture. Recent efforts to address pre-clinical rigor and design, while important, are unable to account for variability present even in genetically homogenous rodents. Indeed, efforts to minimize variability may lessen the clinical relevance of pre-clinical models. We propose a new approach that recognizes the important role of baseline stroke severity and other factors in influencing outcome. Analogous to clinical trials, we propose reporting baseline factors that influence outcome and then adapting for the pre-clinical setting a method developed for clinical trial analysis where the influence of baseline factors is mathematically modeled and the variance quantified. A new therapy's effectiveness is then evaluated relative to the pooled outcome variance at its own baseline conditions. In this way, an objective threshold for robustness can be established that must be overcome to suggest its effectiveness when expanded to broader populations outside of the controlled environment of the PI's laboratory. The method is model neutral and subsumes sources of variance as reflected in baseline factors such as initial stroke severity. We propose that this new approach deserves consideration for providing an objective method to select agents worthy of the commitment of time and resources in translation to clinical trials.
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Affiliation(s)
- Thomas A Kent
- Stroke Outcomes Laboratory, Department of Neurology, Baylor College of Medicine, McNair Campus, 7200 Cambridge St. 9th Floor, MS: BCM609, Houston, TX, 77030, USA.
- Michael E. DeBakey VA Medical Center Stroke Program and Center for Translational Research on Inflammatory Diseases, Houston, TX, USA.
| | - Pitchaiah Mandava
- Stroke Outcomes Laboratory, Department of Neurology, Baylor College of Medicine, McNair Campus, 7200 Cambridge St. 9th Floor, MS: BCM609, Houston, TX, 77030, USA
- Michael E. DeBakey VA Medical Center Stroke Program and Center for Translational Research on Inflammatory Diseases, Houston, TX, USA
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15
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Lee HK, Keum S, Sheng H, Warner DS, Lo DC, Marchuk DA. Natural allelic variation of the IL-21 receptor modulates ischemic stroke infarct volume. J Clin Invest 2016; 126:2827-38. [PMID: 27400126 DOI: 10.1172/jci84491] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 05/12/2016] [Indexed: 02/06/2023] Open
Abstract
Risk for ischemic stroke has a strong genetic basis, but heritable factors also contribute to the extent of damage after a stroke has occurred. We previously identified a locus on distal mouse chromosome 7 that contributes over 50% of the variation in postischemic cerebral infarct volume observed between inbred strains. Here, we used ancestral haplotype analysis to fine-map this locus to 12 candidate genes. The gene encoding the IL-21 receptor (Il21r) showed a marked difference in strain-specific transcription levels and coding variants in neonatal and adult cortical tissue. Collateral vessel connections were moderately reduced in Il21r-deficient mice, and cerebral infarct volume increased 2.3-fold, suggesting that Il21r modulates both collateral vessel anatomy and innate neuroprotection. In brain slice explants, oxygen deprivation (OD) activated apoptotic pathways and increased neuronal cell death in IL-21 receptor-deficient (IL-21R-deficient) mice compared with control animals. We determined that the neuroprotective effects of IL-21R arose from signaling through JAK/STAT pathways and upregulation of caspase 3. Thus, natural genetic variation in murine Il21r influences neuronal cell viability after ischemia by modulating receptor function and downstream signal transduction. The identification of neuroprotective genes based on naturally occurring allelic variations has the potential to inform the development of drug targets for ischemic stroke treatment.
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16
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Wang JJC, Rau C, Avetisyan R, Ren S, Romay MC, Stolin G, Gong KW, Wang Y, Lusis AJ. Genetic Dissection of Cardiac Remodeling in an Isoproterenol-Induced Heart Failure Mouse Model. PLoS Genet 2016; 12:e1006038. [PMID: 27385019 PMCID: PMC4934852 DOI: 10.1371/journal.pgen.1006038] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/18/2016] [Indexed: 12/17/2022] Open
Abstract
We aimed to understand the genetic control of cardiac remodeling using an isoproterenol-induced heart failure model in mice, which allowed control of confounding factors in an experimental setting. We characterized the changes in cardiac structure and function in response to chronic isoproterenol infusion using echocardiography in a panel of 104 inbred mouse strains. We showed that cardiac structure and function, whether under normal or stress conditions, has a strong genetic component, with heritability estimates of left ventricular mass between 61% and 81%. Association analyses of cardiac remodeling traits, corrected for population structure, body size and heart rate, revealed 17 genome-wide significant loci, including several loci containing previously implicated genes. Cardiac tissue gene expression profiling, expression quantitative trait loci, expression-phenotype correlation, and coding sequence variation analyses were performed to prioritize candidate genes and to generate hypotheses for downstream mechanistic studies. Using this approach, we have validated a novel gene, Myh14, as a negative regulator of ISO-induced left ventricular mass hypertrophy in an in vivo mouse model and demonstrated the up-regulation of immediate early gene Myc, fetal gene Nppb, and fibrosis gene Lgals3 in ISO-treated Myh14 deficient hearts compared to controls. Heart failure is the most common cause of morbidity and mortality in the aging population. Previous large-scale human genome-wide association studies have yielded only a handful of genetic loci contributing to heart failure-related traits. Using a panel of diverse inbred mouse strains, treated with a β-adrenergic agonist isoproterenol to mimic the heart failure state, we sought to uncover the contribution of common genetic variation in heart failure. We found that heart failure has a strong genetic component. We successfully identified 17 genome-wide significant loci associated with indices of heart failure. We showed that genetic variation in a novel gene Myh14 affects heart failure by altering the mechanical responses of heart muscles to isoproterenol-induced stress. Follow-up studies of this gene and additional candidate genes and loci should reveal potential mechanisms by which genetic variations contribute to heart failure in the general human population. Such insights may lead to improved diagnosis and tailor treatment based on the genetic makeup of individuals in the population.
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Affiliation(s)
- Jessica Jen-Chu Wang
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail: (JJCW); (AJL)
| | - Christoph Rau
- Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Rozeta Avetisyan
- Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Shuxun Ren
- Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Milagros C. Romay
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Gabriel Stolin
- Department of Molecular, Cell, and Developmental Biology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Ke Wei Gong
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Yibin Wang
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Aldons J. Lusis
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail: (JJCW); (AJL)
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17
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Bustamante-Marin XM, Cook MS, Gooding J, Newgard C, Capel B. Left-Biased Spermatogenic Failure in 129/SvJ Dnd1Ter/+ Mice Correlates with Differences in Vascular Architecture, Oxygen Availability, and Metabolites. Biol Reprod 2015; 93:78. [PMID: 26224005 PMCID: PMC6322448 DOI: 10.1095/biolreprod.115.128850] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 03/06/2015] [Accepted: 07/06/2015] [Indexed: 01/19/2023] Open
Abstract
Homozygosity for the Ter mutation in the RNA-binding protein Dead end 1 (Dnd1(Ter/Ter)) sensitizes germ cells to degeneration in all mouse strains. In 129/SvJ mice, approximately 10% of Dnd1(Ter/+) heterozygotes develop spermatogenic failure, and 95% of unilateral cases occur in the left testis. The first differences between right and left testes were detected at Postnatal Day 15 when many more spermatogonial stem cells (SSCs) were undergoing apoptosis in the left testis compared to the right. As we detected no significant left/right differences in the molecular pathway associated with body axis asymmetry or in the expression of signals known to promote proliferation, differentiation, and survival of germ cells, we investigated whether physiological differences might account for asymmetry of the degeneration phenotype. We show that left/right differences in vascular architecture are associated with a decrease in hemoglobin saturation and increased levels of HIF-1alpha in the left testis compared to the right. In Dnd1 heterozygotes, lower oxygen availability was associated with metabolic differences, including lower levels of ATP and NADH in the left testis. These experiments suggest a dependence on oxygen availability and metabolic substrates for SSC survival and suggest that Dnd1(Ter/+) SSCs may act as efficient sensors to detect subtle environmental changes that alter SSC fate.
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Affiliation(s)
- Ximena M Bustamante-Marin
- Department of Cell Biology, Duke University, Durham, North Carolina Departmento Biomédico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Matthew S Cook
- Department of Cell Biology, Duke University, Durham, North Carolina Department of Anatomy, University of California, San Francisco, California
| | - Jessica Gooding
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Departments of Pharmacology and Cancer Biology & Medicine, Duke University Medical Center, Durham, North Carolina
| | - Christopher Newgard
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Departments of Pharmacology and Cancer Biology & Medicine, Duke University Medical Center, Durham, North Carolina
| | - Blanche Capel
- Department of Cell Biology, Duke University, Durham, North Carolina
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18
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Fluri F, Schuhmann MK, Kleinschnitz C. Animal models of ischemic stroke and their application in clinical research. DRUG DESIGN DEVELOPMENT AND THERAPY 2015; 9:3445-54. [PMID: 26170628 PMCID: PMC4494187 DOI: 10.2147/dddt.s56071] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This review outlines the most frequently used rodent stroke models and discusses their strengths and shortcomings. Mimicking all aspects of human stroke in one animal model is not feasible because ischemic stroke in humans is a heterogeneous disorder with a complex pathophysiology. The transient or permanent middle cerebral artery occlusion (MCAo) model is one of the models that most closely simulate human ischemic stroke. Furthermore, this model is characterized by reliable and well-reproducible infarcts. Therefore, the MCAo model has been involved in the majority of studies that address pathophysiological processes or neuroprotective agents. Another model uses thromboembolic clots and thus is more convenient for investigating thrombolytic agents and pathophysiological processes after thrombolysis. However, for many reasons, preclinical stroke research has a low translational success rate. One factor might be the choice of stroke model. Whereas the therapeutic responsiveness of permanent focal stroke in humans declines significantly within 3 hours after stroke onset, the therapeutic window in animal models with prompt reperfusion is up to 12 hours, resulting in a much longer action time of the investigated agent. Another major problem of animal stroke models is that studies are mostly conducted in young animals without any comorbidity. These models differ from human stroke, which particularly affects elderly people who have various cerebrovascular risk factors. Choosing the most appropriate stroke model and optimizing the study design of preclinical trials might increase the translational potential of animal stroke models.
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Affiliation(s)
- Felix Fluri
- Department of Neurology, University Clinic Wuerzburg, Wuerzburg, Germany
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19
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Nishijima Y, Akamatsu Y, Weinstein PR, Liu J. Collaterals: Implications in cerebral ischemic diseases and therapeutic interventions. Brain Res 2015; 1623:18-29. [PMID: 25770816 DOI: 10.1016/j.brainres.2015.03.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 02/09/2023]
Abstract
Despite the tremendous progress made in the treatment of cerebrovascular occlusive diseases, many patients suffering from ischemic brain injury still experience dismal outcomes. Although rehabilitation contributes to post-stroke functional recovery, there is no doubt that interventions that promote the restoration of blood supply are proven to minimize ischemic injury and improve recovery. In response to the acutely decreased blood perfusion during arterial occlusion, arteriogenesis, the compensation of blood flow through the collateral circulation during arterial obstructive diseases can act not only in a timely fashion but also much more efficiently compared to angiogenesis, the sprouting of new capillaries, and a mechanism occurring in a delayed fashion while increases the total resistance of the vascular bed of the affected territory. Interestingly, despite the vast differences between the two vascular remodeling mechanisms, some crucial growth factors and cytokines involved in angiogenesis are also required for arteriogenesis. Understanding the mechanisms underlying vascular remodeling after ischemic brain injury is a critical step towards the development of effective therapies for ischemic stroke. The present article will discuss our current views in vascular remodeling acutely after brain ischemia, namely arteriogenesis, and some relevant clinical therapies available on the horizon in augmenting collateral flow that hold promise in treating ischemic brain injury. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke.
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Affiliation(s)
- Yasuo Nishijima
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA; Department of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yosuke Akamatsu
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA; Department of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Phillip R Weinstein
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA
| | - Jialing Liu
- Department of Neurological Surgery, UCSF, San Francisco, CA 94121, USA; SFVAMC, San Francisco, CA 94121, USA.
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20
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Electro-acupuncture at Neiguan pretreatment alters genome-wide gene expressions and protects rat myocardium against ischemia-reperfusion. Molecules 2014; 19:16158-78. [PMID: 25302705 PMCID: PMC6271995 DOI: 10.3390/molecules191016158] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 12/14/2022] Open
Abstract
This study investigated genome-wide gene expressions and the cardioprotective effects of electro-acupuncture pretreatment at the PC6 Neiguan acupoint on myocardial ischemia reperfusion (I/R) injury. Male SD rats were randomly divided into four groups: sham operation (SO), I/R, electro-acupuncture at the PC6 Neiguan acupoint pretreatment (EA) and electro-acupuncture at non-acupoint pretreatment (NA). Compared with the I/R group, the survival rate of the EA group was significantly increased, the arrhythmia score, infarction area, serum concentrations of CK, LDH and CK-Mb and plasma level of cTnT were significantly decreased. RNA-seq results showed that 725 genes were up-regulated and 861 genes were down-regulated under I/R conditions compared to the SO group; both EA and NA reversed some of these gene expression levels (592 in EA and 238 in NA group). KEGG pathway analysis indicated that these genes were involved in multiple pathways, including ECM, MAPK signaling, apoptosis, cytokine and leukocyte pathways. In addition, some pathways were uniquely regulated by EA, but not NA pretreatment, such as oxidative stress, cardiac muscle contraction, gap junction, vascular smooth muscle contraction, hypertrophic, NOD-like receptor, and P53 and B-cell receptor pathways. This study was first to reveal the gene expression signatures of acute myocardial I/R injury and electro-acupuncture pretreatment in rats.
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21
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Sealock R, Zhang H, Lucitti JL, Moore SM, Faber JE. Congenic fine-mapping identifies a major causal locus for variation in the native collateral circulation and ischemic injury in brain and lower extremity. Circ Res 2013; 114:660-71. [PMID: 24300334 DOI: 10.1161/circresaha.114.302931] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
RATIONALE Severity of tissue injury in occlusive disease is dependent on the extent (number and diameter) of collateral vessels, which varies widely among healthy mice and humans. However, the causative genetic elements are unknown. Recently, much of the variation among different mouse strains, including C57Bl/6J (B6, high extent) and BALB/cByJ (Bc, low extent), was linked to a quantitative trait locus on chromosome 7 (Candq1). OBJECTIVE We used congenic mapping to refine Candq1 and its candidate genes to create an isogenic strain set with large differences in collateral extent to assess their impact and the impact of Candq1, alone, on ischemic injury. METHODS AND RESULTS Six congenic strains possessing portions of Candq1 introgressed from B6 into Bc were generated and phenotyped. Candq1 was refined from 27 to 0.737 Mb with full retention of effect, that is, return or rescue of phenotypes from the poor values in Bc to nearly those of wild-type B6 in the B6/B6 congenic mice as follows: 83% rescue of low pial collateral extent and 4.5-fold increase in blood flow and 85% reduction of infarct volume after middle cerebral artery occlusion; 54% rescue of low skeletal muscle collaterals and augmented recovery of perfusion (83%) and function after femoral artery ligation. Gene deletion and in silico analysis further delineated the candidate genes. CONCLUSIONS We have significantly refined Candq1 (now designated determinant of collateral extent 1; Dce1), demonstrated that genetic background-dependent variation in collaterals is a major factor underlying differences in ischemic tissue injury, and generated a congenic strain set with wide allele dose-dependent variation in collateral extent for use in investigations of the collateral circulation.
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Affiliation(s)
- Robert Sealock
- From the Departments of Cell Biology and Physiology (R.S., H.Z., J.L.L., J.E.F.) and Surgery (S.M.M.), and The McAllister Heart Institute (H.Z., J.L.L., J.E.F.), School of Medicine, University of North Carolina at Chapel Hill, NC
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22
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Keum S, Lee HK, Chu PL, Kan MJ, Huang MN, Gallione CJ, Gunn MD, Lo DC, Marchuk DA. Natural genetic variation of integrin alpha L (Itgal) modulates ischemic brain injury in stroke. PLoS Genet 2013; 9:e1003807. [PMID: 24130503 PMCID: PMC3794904 DOI: 10.1371/journal.pgen.1003807] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 08/05/2013] [Indexed: 11/18/2022] Open
Abstract
During ischemic stroke, occlusion of the cerebrovasculature causes neuronal cell death (infarction), but naturally occurring genetic factors modulating infarction have been difficult to identify in human populations. In a surgically induced mouse model of ischemic stroke, we have previously mapped Civq1 to distal chromosome 7 as a quantitative trait locus determining infarct volume. In this study, genome-wide association mapping using 32 inbred mouse strains and an additional linkage scan for infarct volume confirmed that the size of the infarct is determined by ancestral alleles of the causative gene(s). The genetically isolated Civq1 locus in reciprocal recombinant congenic mice refined the critical interval and demonstrated that infarct size is determined by both vascular (collateral vessel anatomy) and non-vascular (neuroprotection) effects. Through the use of interval-specific SNP haplotype analysis, we further refined the Civq1 locus and identified integrin alpha L (Itgal) as one of the causative genes for Civq1. Itgal is the only gene that exhibits both strain-specific amino acid substitutions and expression differences. Coding SNPs, a 5-bp insertion in exon 30b, and increased mRNA and protein expression of a splice variant of the gene (Itgal-003, ENSMUST00000120857), all segregate with infarct volume. Mice lacking Itgal show increased neuronal cell death in both ex vivo brain slice and in vivo focal cerebral ischemia. Our data demonstrate that sequence variation in Itgal modulates ischemic brain injury, and that infarct volume is determined by both vascular and non-vascular mechanisms.
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Affiliation(s)
- Sehoon Keum
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Han Kyu Lee
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Pei-Lun Chu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Matthew J. Kan
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Min-Nung Huang
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Carol J. Gallione
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Michael D. Gunn
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Donald C. Lo
- Center for Drug Discovery and Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Douglas A. Marchuk
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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