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Chachua T, Goletiani C, Maglakelidze G, Sidyelyeva G, Daniel M, Morris E, Miller J, Shang E, Wolgemuth DJ, Greenberg DA, Velíšková J, Velíšek L. Sex-specific behavioral traits in the Brd2 mouse model of juvenile myoclonic epilepsy. GENES BRAIN AND BEHAVIOR 2014; 13:702-12. [PMID: 25130458 DOI: 10.1111/gbb.12160] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/31/2014] [Accepted: 08/04/2014] [Indexed: 12/23/2022]
Abstract
Idiopathic generalized epilepsy represents about 30-35% of all epilepsies in humans. The bromodomain BRD2 gene has been repeatedly associated with the subsyndrome of juvenile myoclonic epilepsy (JME). Our previous work determined that mice haploinsufficient in Brd2 (Brd2+/-) have increased susceptibility to provoked seizures, develop spontaneous seizures and have significantly decreased gamma-aminobutyric acid (GABA) markers in the direct basal ganglia pathway as well as in the neocortex and superior colliculus. Here, we tested male and female Brd2+/- and wild-type littermate mice in a battery of behavioral tests (open field, tube dominance test, elevated plus maze, Morris water maze and Barnes maze) to identify whether Brd2 haploinsufficiency is associated with the human behavioral patterns, the so-called JME personality. Brd2+/- females but not males consistently displayed decreased anxiety. Furthermore, we found a highly significant dominance trait (aggression) in the Brd2+/- mice compared with the wild type, more pronounced in females. Brd2+/- mice of either sex did not differ from wild-type mice in spatial learning and memory tests. Compared with wild-type littermates, we found decreased numbers of GABA neurons in the basolateral amygdala, which is consistent with the increase in aggressive behavior. Our results indicate that Brd2+/- haploinsufficient mice show no cognitive impairment but have behavioral traits similar to those found in patients with JME (recklessness, aggression). This suggests that either the BRD2 gene is directly responsible for influencing many traits of JME or it controls upstream regulators of individual phenotypes.
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Subaran RL, Greenberg DA. The Genetics of Common Epilepsy Disorders: Lessons Learned from the Channelopathy Era. CURRENT GENETIC MEDICINE REPORTS 2014. [DOI: 10.1007/s40142-014-0040-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mao X, Xie L, Greenberg RB, Greenberg JB, Peng B, Mieling I, Jin K, Greenberg DA. Flow-induced regulation of brain endothelial cells in vitro. Vascul Pharmacol 2014; 62:82-7. [DOI: 10.1016/j.vph.2014.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 01/31/2014] [Accepted: 02/18/2014] [Indexed: 10/25/2022]
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Brown RS, Lombardi A, Hasham A, Greenberg DA, Gordon J, Concepcion E, Hammerstad SS, Lotay V, Zhang W, Tomer Y. Genetic analysis in young-age-of-onset Graves' disease reveals new susceptibility loci. J Clin Endocrinol Metab 2014; 99:E1387-91. [PMID: 24684463 PMCID: PMC4079314 DOI: 10.1210/jc.2013-4358] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
CONTEXT Genetic and environmental factors play an essential role in the pathogenesis of Graves' Disease (GD). Children with GD have less exposure time to environmental factors and therefore are believed to harbor stronger genetic susceptibility than adults. OBJECTIVE The aim of the study was to identify susceptibility loci that predispose to GD in patients with young-age-of-onset (YAO) GD. SETTING AND DESIGN One hundred six patients with YAO GD (onset <30 y) and 855 healthy subjects were studied. Cases and controls were genotyped using the Illumina Infinium Immunochip, designed to genotype 196,524 polymorphisms. Case control association analyses were performed using the PLINK computer package. Ingenuity Pathway Analysis program (QIAGEN) was used to carry out pathway analyses. RESULTS Immunochip genetic association analysis identified 30 single-nucleotide polymorphisms in several genes that were significantly associated with YAO GD, including major histocompatibility complex class I and class II genes, BTNL2, NOTCH4, TNFAIP3, and CXCR4. Candidate gene analysis revealed that most of the genes previously shown to be associated with adult-onset GD were also associated with YAO GD. Pathway analysis demonstrated that antigen presentation, T-helper cell differentiation, and B cell development were the major pathways contributing to the pathogenesis of YAO GD. CONCLUSIONS Genetic analysis identified novel susceptibility loci in YAO GD adding a new dimension to the understanding of GD etiology.
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Sun YX, Ji X, Mao X, Xie L, Jia J, Galvan V, Greenberg DA, Jin K. Differential activation of mTOR complex 1 signaling in human brain with mild to severe Alzheimer's disease. J Alzheimers Dis 2014; 38:437-44. [PMID: 23979023 DOI: 10.3233/jad-131124] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mammalian target of rapamycin (mTOR) signaling has been suggested to be effective in modifying cognitive status in animal models of Alzheimer's disease (AD), but little is known about its role in AD patients. We hereby tested whether mTOR signaling was activated and whether activated mTOR signaling was related to the degree of cognitive deficits in patients with AD. Autopsy brain hippocampal tissues were obtained from controls and patients with AD and Western blots were performed using antibodies against mTOR signaling molecules and RagC, an upstream component of mTOR complex 1 (mTORC1) signaling. We found that expression of mTOR/p-mTOR and its downstream targets S6/p-S6 and Raptor/p-Raptor were expressed in the control and AD hippocampus. The expression levels of these signaling molecules were significantly increased in the hippocampus at the severe stages of AD, compared to controls and other stages of AD. Interestingly, Rictor expression level was unaltered. In addition, RagC was increased in the hippocampus at the early, moderate, and severe stages of AD. Our data indicate that mTORC1, but not mTORC2, was activated in the AD brains and that the level of mTOR signaling activation was correlated with cognitive severity of AD patients.
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Stewart WC, Huang Y, Greenberg DA, Vieland VJ. Next-generation linkage and association methods applied to hypertension: a multifaceted approach to the analysis of sequence data. BMC Proc 2014; 8:S111. [PMID: 25519364 PMCID: PMC4143636 DOI: 10.1186/1753-6561-8-s1-s111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
To realize the full potential of next-generation sequencing, it is important to consider multiple sources of genetic information, including inheritance, association, and bioinformatics. To illustrate the promise of such an approach, we applied our next-generation linkage and association (NGLA) methods to the sequence data of a large 57-member Mexican American family with hypertension. Our results show that OSBPL10--a disease susceptibility gene for dyslipidemia--may also influence systolic blood pressure (SBP). In particular, our NGLA dense single-nucleotide polymorphism (SNP) analysis identified a 2.5-megabase (Mb) region that strongly cosegregates with low SBP (maximum posterior probability of linkage [PPL] = 68%). Furthermore, using the posterior probability of linkage disequilibrium (PPLD), we fine-mapped this region and identified 12 SBP-associated variants (PPLD ranging between 4% and 14%) that comprise a rare, 4-site haplotype. This haplotype extends into the candidate gene, OSBPL10 (oxysterol-binding protein-like 10). In contrast to our NGLA methods, a commonly used filter-based approach identified 23 variants with little evidence for spatial clustering around any particular gene or region of interest.
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Xie L, Sun F, Wang J, Mao X, Xie L, Yang SH, Su DM, Simpkins JW, Greenberg DA, Jin K. mTOR signaling inhibition modulates macrophage/microglia-mediated neuroinflammation and secondary injury via regulatory T cells after focal ischemia. THE JOURNAL OF IMMUNOLOGY 2014; 192:6009-19. [PMID: 24829408 DOI: 10.4049/jimmunol.1303492] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Signaling by the mammalian target of rapamycin (mTOR) plays an important role in the modulation of both innate and adaptive immune responses. However, the role and underlying mechanism of mTOR signaling in poststroke neuroinflammation are largely unexplored. In this study, we injected rapamycin, a mTOR inhibitor, by the intracerebroventricular route 6 h after focal ischemic stroke in rats. We found that rapamycin significantly reduced lesion volume and improved behavioral deficits. Notably, infiltration of γδ T cells and granulocytes, which are detrimental to the ischemic brain, was profoundly reduced after rapamycin treatment, as was the production of proinflammatory cytokines and chemokines by macrophages and microglia. Rapamycin treatment prevented brain macrophage polarization toward the M1 type. In addition, we also found that rapamycin significantly enhanced anti-inflammation activity of regulatory T cells (Tregs), which decreased production of proinflammatory cytokines and chemokines by macrophages and microglia. Depletion of Tregs partially elevated macrophage/microglia-induced neuroinflammation after stroke. Our data suggest that rapamycin can attenuate secondary injury and motor deficits after focal ischemia by enhancing the anti-inflammation activity of Tregs to restrain poststroke neuroinflammation.
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Corso B, Greenberg DA. Using linkage analysis to detect gene-gene interaction by stratifying family data on known disease, or disease-associated, alleles. PLoS One 2014; 9:e93398. [PMID: 24690899 PMCID: PMC3972093 DOI: 10.1371/journal.pone.0093398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 03/03/2014] [Indexed: 11/22/2022] Open
Abstract
Detecting gene-gene interaction in complex diseases is a major challenge for common disease genetics. Most interaction detection approaches use disease-marker associations and such methods have low power and unknown reliability in real data. We developed and tested a powerful linkage-analysis-based gene-gene interaction detection strategy based on conditioning the family data on a known disease-causing allele or disease-associated marker allele. We computer-generated multipoint linkage data for a disease caused by two epistatically interacting loci (A and B). We examined several two-locus epistatic inheritance models: dominant-dominant, dominant-recessive, recessive-dominant, recessive-recessive. At one of the loci (A), there was a known disease-related allele. We stratified the family data on the presence of this allele, eliminating family members who were without it. This elimination step has the effect of raising the “penetrance” at the second locus (B). We then calculated the lod score at the second locus (B) and compared the pre- and post-stratification lod scores at B. A positive difference indicated interaction. We also examined if it was possible to detect interaction with locus B based on a disease-marker association (instead of an identified disease allele) at locus A. We also tested whether the presence of genetic heterogeneity would generate false positive evidence of interaction. The power to detect interaction for a known disease allele was 60–90%. The probability of false positives, based on heterogeneity, was low. Decreasing linkage disequilibrium between the disease and marker at locus A decreased the likelihood of detecting interaction. The allele frequency of the associated marker made little difference to the power.
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Sun F, Mao X, Xie L, Greenberg DA, Jin K. Neuroglobin Protein is Upregulated in Alzheimer's Disease. ACTA ACUST UNITED AC 2013; 36:659-63. [DOI: 10.3233/jad-130323] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Haines B, Mao X, Xie L, Spusta S, Zeng X, Jin K, Greenberg DA. Neuroglobin expression in neurogenesis. Neurosci Lett 2013; 549:3-6. [PMID: 23643985 DOI: 10.1016/j.neulet.2013.04.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/11/2013] [Accepted: 04/12/2013] [Indexed: 01/15/2023]
Abstract
Neuroglobin is a hypoxia-inducible, neuroprotective protein related to myoglobin and hemoglobin, but little is known about its neurodevelopmental expression or function. To begin to explore these issues, we measured neuroglobin protein expression during neuronal differentiation of human embryonic stem cells in vitro and in the neurogenic subventricular zone of adult rats in vivo. Neuroglobin protein expression was barely detectable by western blotting in human embryonic stem cells, but was readily demonstrable in neural stem cells, and was further induced upon differentiation to neurons. In the adult subventricular zone, neuroglobin expression coincided with that of the neuronal lineage marker doublecortin, but not with vimentin or glial fibrillary acidic protein. These findings suggest that neuroglobin is expressed early in the course of neuronal differentiation and may, therefore, have a role in neurodevelopment.
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Lipner EM, Tomer Y, Noble JA, Monti MC, Lonsdale JT, Corso B, Stewart WCL, Greenberg DA. HLA class I and II alleles are associated with microvascular complications of type 1 diabetes. Hum Immunol 2013; 74:538-44. [PMID: 23376458 PMCID: PMC3686564 DOI: 10.1016/j.humimm.2013.01.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 12/13/2012] [Accepted: 01/14/2013] [Indexed: 12/25/2022]
Abstract
Although HLA alleles are associated with type 1 diabetes, association with microvascular complications remains controversial. We tested HLA association with complications in multiplex type 1 diabetes families. Probands from 425 type 1 diabetes families from the Human Biological Data Interchange (HBDI) collection were analyzed. The frequencies of specific HLA alleles in patients with complications were compared with the frequencies in complications-free patients. The complications we examined were: retinopathy, neuropathy, and nephropathy. We used logistic regression models with covariates to estimate odds ratios. We found that the DRB1*03:01 allele is a protective factor for complications (OR=0.58; p=0.03), as is the DQA1*05:01-DQB1*02:01 haplotype found in linkage disequilibrium with DRB1*03:01 (OR=0.59; p=0.031). The DRB1*04:01 allele showed no evidence of association (OR=1.13; p=0.624), although DRB1*04:01 showed suggestive evidence when the carriers of the protective DRB1*03:01 were removed from the analysis. The class II DQA1*03:01-DQB1*03:02 haplotype was not associated with complications, but the class I allele B*39:06 (OR=3.27; p=0.008) suggested a strong positive association with complications. Our results show that in type 1 diabetes patients, specific HLA alleles may be involved in susceptibility to, or protection from, microvascular complications.
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Sun F, Xie L, Mao X, Hill J, Greenberg DA, Jin K. Effect of a contralateral lesion on neurological recovery from stroke in rats. Restor Neurol Neurosci 2013; 30:491-5. [PMID: 22868223 DOI: 10.3233/rnn-2012-120254] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE Clinical studies suggest a correlation between changes in activity of the contralesional cerebral cortex and spontaneous recovery from stroke, but whether this is a causal relationship is uncertain. METHODS Young adult Sprague-Dawley male rats underwent unilateral or bilateral permanent distal middle cerebral artery occlusion (dMCAO). Infarct volume was determined by 2,3,5-triphenyltetrazolium chloride (TTC) staining 24 hr after dMCAO, and functional outcome was assessed 1-28 days after dMCAO using the ladder rung walking and limb placing tests. RESULTS Infarct volume was unchanged, but functional neurological deficits were reduced 1 day after bilateral compared to unilateral dMCAO. CONCLUSIONS Activity in the contralesional cerebral cortex may inhibit functional motor recovery after experimental stroke.
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Xie L, Mao X, Jin K, Greenberg DA. Vascular endothelial growth factor-B expression in postischemic rat brain. Vasc Cell 2013; 5:8. [PMID: 23601533 PMCID: PMC3671984 DOI: 10.1186/2045-824x-5-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 04/19/2013] [Indexed: 01/27/2023] Open
Abstract
Background Vascular endothelial growth factor-B (VEGF-B) protects against experimental stroke, but the effect of stroke on VEGF-B expression is uncertain. Methods We examined VEGF-B expression by immunohistochemistry in the ischemic border zone 1–7 days after middle cerebral artery occlusion in rats. Results VEGF-B immunoreactivity in the border zone was increased after middle cerebral artery occlusion and was associated with neurons and macrophages/microglia, but not astrocytes or endothelial cells. Conclusions These findings provide additional evidence for a role of VEGF-B in the endogenous response to cerebral ischemia.
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Tomer Y, Hasham A, Davies TF, Stefan M, Concepcion E, Keddache M, Greenberg DA. Fine mapping of loci linked to autoimmune thyroid disease identifies novel susceptibility genes. J Clin Endocrinol Metab 2013; 98:E144-52. [PMID: 23118423 PMCID: PMC3537111 DOI: 10.1210/jc.2012-2408] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CONTEXT Genetic factors play a major role in the etiology of autoimmune thyroid disease (AITD) including Graves' disease (GD) and Hashimoto's thyroiditis (HT). We have previously identified three loci on chromosomes 10q, 12q, and 14q that showed strong linkage with AITD, HT, and GD, respectively. OBJECTIVES The objective of the study was to identify the AITD susceptibility genes at the 10q, 12q, and 14q loci. DESIGN AND PARTICIPANTS Three hundred forty North American Caucasian AITD patients and 183 healthy controls were studied. The 10q, 12q, and 14q loci were fine mapped by genotyping densely spaced single-nucleotide polymorphisms (SNPs) using the Illumina GoldenGate genotyping platform. Case control association analyses were performed using the UNPHASED computer package. Associated SNPs were reanalyzed in a replication set consisting of 238 AITD patients and 276 controls. RESULTS Fine mapping of the AITD locus, 10q, showed replicated association of the AITD phenotype (both GD and HT) with SNP rs6479778. This SNP was located within the ARID5B gene recently reported to be associated with rheumatoid arthritis and GD in Japanese. Fine mapping of the GD locus, 14q, revealed replicated association of the GD phenotype with two markers, rs12147587 and rs2284720, located within the NRXN3 and TSHR genes, respectively. CONCLUSIONS Fine mapping of three linked loci identified novel susceptibility genes for AITD. The discoveries of new AITD susceptibility genes will engender a new understanding of AITD etiology.
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Tang H, Mao X, Xie L, Greenberg DA, Jin K. Expression level of vascular endothelial growth factor in hippocampus is associated with cognitive impairment in patients with Alzheimer's disease. Neurobiol Aging 2012. [PMID: 23182805 DOI: 10.1016/j.neurobiolaging.2012.10.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Although the enhanced expression of vascular endothelial growth factor (VEGF) in the brains of patients with Alzheimer's disease (AD) has been reported, the functional significance of VEGF level in the progression of AD is still unclear. We examined the VEGF expression in the hippocampus of patients with AD at different stages of progression by Western blot analysis, and found that the VEGF189 isoform (VEGF(189)) was barely detectable in normal hippocampus, but significantly increased at the early stage of patients with AD. VEGF(189) was decreased with advancing stages of AD. Immunostaining shows that VEGF was significantly increased in the cells in the CA1, CA3, and dentate gyrus regions of hippocampus and layers III and V of entorhinal cortex of patients with AD, compared with normal brain. Confocal images show that VEGF was predominantly expressed in neurons and astrocytes in the hippocampus and entorhinal cortex of patients with AD. Our data suggest that VEGF level is associated with progressive loss of cognitive function in patients with AD.
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Greenberg DA, Stewart WCL. How should we be searching for genes for common epilepsy? A critique and a prescription. Epilepsia 2012; 53 Suppl 4:72-80. [PMID: 22946724 DOI: 10.1111/j.1528-1167.2012.03616.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Despite enormous data collection and analysis efforts, the genetic influences on common epilepsies remain mostly unknown. We propose that reasons for the lack of progress can be traced to three factors: (1) A reluctance to consider fine-grained phenotype definitions based on extensive and carefully collected clinical data; (2) the pursuit of genetic analysis methods that are popular but poorly conceived and are inadequate to the task of resolving the problems inherent in common disease studies; (3) preconceived ideas about the genetic mechanisms that cause epilepsy (which we have discussed elsewhere). We propose a paradigm for finding epilepsy-related loci and alleles that has proven successful in other common diseases.
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Haines BA, Davis DA, Zykovich A, Peng B, Rao R, Mooney SD, Jin K, Greenberg DA. Comparative protein interactomics of neuroglobin and myoglobin. J Neurochem 2012; 123:192-8. [PMID: 22816983 DOI: 10.1111/j.1471-4159.2012.07881.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neuroglobin is a hypoxia-inducible O(2)-binding protein with neuroprotective effects in cell and animal models of stroke and Alzheimer's disease. The mechanism underlying neuroglobin's cytoprotective action is unknown, although several possibilities have been proposed, including anti-oxidative and anti-apoptotic effects. We used affinity purification-mass spectrometry methods to identify neuroglobin-interacting proteins in normoxic and hypoxic murine neuronal (HN33) cell lysates, and to compare these interactions with those of a structurally and functionally related protein, myoglobin. We report that the protein interactomes of neuroglobin and myoglobin overlap substantially and are modified by hypoxia. In addition, neuroglobin-interacting proteins include partners consistent with both anti-oxidative and anti-apoptotic functions, as well as with a relationship to several neurodegenerative diseases.
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Wang X, Mao X, Xie L, Sun F, Greenberg DA, Jin K. Conditional depletion of neurogenesis inhibits long-term recovery after experimental stroke in mice. PLoS One 2012; 7:e38932. [PMID: 22723908 PMCID: PMC3378583 DOI: 10.1371/journal.pone.0038932] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 05/14/2012] [Indexed: 11/19/2022] Open
Abstract
We reported previously that ablation of doublecortin (DCX)-immunopositive newborn neurons in mice worsens anatomical and functional outcome measured 1 day after experimental stroke, but whether this effect persists is unknown. We generated transgenic mice that express herpes simplex virus thymidine kinase under control of the DCX promoter (DCX-TK transgenic mice). DCX-expressing and recently divided cells in the rostral subventricular zone (SVZ) and hippocampus of DCX-TK transgenic mice, but not wild-type mice, were specifically depleted after ganciclovir (GCV) treatment for 14 days. Focal cerebral ischemia was induced by permanent distal middle cerebral artery occlusion (MCAO) on day 14 of vehicle or GCV treatment, and mice were killed 12 weeks after MCAO. Infarct volume was significantly increased and neurologic deficits were more severe in GCV- compared to vehicle-treated DCX-TK transgenic mice at first 8 weeks, after depletion of DCX- and bromodeoxyuridine-immunoreactive cells in the SVZ and dentate gyrus following focal ischemia. Our results indicate that endogenous neurogenesis in a critical period following experimental stroke influences the course of long-term recovery.
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Jin K, Mao X, Xie L, Greenberg DA. Interactions between vascular endothelial growth factor and neuroglobin. Neurosci Lett 2012; 519:47-50. [PMID: 22583764 DOI: 10.1016/j.neulet.2012.05.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 05/02/2012] [Accepted: 05/03/2012] [Indexed: 12/26/2022]
Abstract
Vascular endothelial growth factor (VEGF) and neuroglobin (Ngb) participate in neuronal responses to hypoxia and ischemia, but the relationship between their effects, if any, is unknown. To address this issue, we measured Ngb levels in VEGF-treated mouse cerebrocortical cultures and VEGF levels in cerebrocortical cultures from Ngb-overexpressing transgenic mice. VEGF stimulated Ngb expression in a VEGFR2/Flk1 receptor-dependent manner, whereas Ngb overexpression suppressed expression of VEGF. These findings provide further insight into hypoxia-stimulated neuronal signaling pathways.
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Shang E, Cui Q, Wang X, Beseler C, Greenberg DA, Wolgemuth DJ. The bromodomain-containing gene BRD2 is regulated at transcription, splicing, and translation levels. J Cell Biochem 2012; 112:2784-93. [PMID: 21608014 DOI: 10.1002/jcb.23192] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The human BRD2 gene has been linked and associated with a form of common epilepsy and electroencephalographic abnormalities. Disruption of Brd2 in the mouse revealed that it is essential for embryonic neural development and that viable Brd2(+/-) heterozygotes show both decreased GABAergic neuron counts and increased susceptibility to seizures. To understand the molecular mechanisms by which mis-expression of BRD2 might contribute to epilepsy, we examined its regulation at multiple levels. We discovered that BRD2 expresses distinct tissue-specific transcripts that originate from different promoters and have strikingly different lengths of 5' untranslated regions (5'UTR). We also experimentally confirmed the presence of a highly conserved, alternatively spliced exon, inclusion of which would result in a premature termination of translation. Downstream of this alternative exon is a polymorphic microsatellite (GT-repeats). Manipulation of the number of the GT-repeats revealed that the length of the GT-repeats affects the ratio of the two alternative splicing products. In vitro translation and expression in cultured cells revealed that among the four different mRNAs (long and short 5'UTR combined with regular and alternative splicing), only the regularly spliced mRNA with the short 5'UTR yields full-length protein. In situ hybridization and immunohistochemical studies showed that although Brd2 mRNA is expressed in both the hippocampus and cerebellum, Brd2 protein only can be detected in the cerebellar Purkinje cells and not in hippocampal cells. These multiple levels of regulation would likely affect the production of functional BRD2 protein during neural development and hence, its role in the etiology of seizure susceptibility.
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Greenberg DA. Computer simulation is an undervalued tool for genetic analysis: a historical view and presentation of SHIMSHON--a Web-based genetic simulation package. Hum Hered 2011; 72:247-57. [PMID: 22189467 DOI: 10.1159/000330633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Computer simulation methods are under-used tools in genetic analysis because simulation approaches have been portrayed as inferior to analytic methods. Even when simulation is used, its advantages are not fully exploited. Here, I present SHIMSHON, our package of genetic simulation programs that have been developed, tested, used for research, and used to generated data for Genetic Analysis Workshops (GAW). These simulation programs, now web-accessible, can be used by anyone to answer questions about designing and analyzing genetic disease studies for locus identification. This work has three foci: (1) the historical context of SHIMSHON's development, suggesting why simulation has not been more widely used so far. (2) Advantages of simulation: computer simulation helps us to understand how genetic analysis methods work. It has advantages for understanding disease inheritance and methods for gene searches. Furthermore, simulation methods can be used to answer fundamental questions that either cannot be answered by analytical approaches or cannot even be defined until the problems are identified and studied, using simulation. (3) I argue that, because simulation was not accepted, there was a failure to grasp the meaning of some simulation-based studies of linkage. This may have contributed to perceived weaknesses in linkage analysis; weaknesses that did not, in fact, exist.
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Guan Y, Wang Y, Yuan F, Lu H, Ren Y, Xiao T, Chen K, Greenberg DA, Jin K, Yang GY. Effect of suture properties on stability of middle cerebral artery occlusion evaluated by synchrotron radiation angiography. Stroke 2011; 43:888-91. [PMID: 22180249 DOI: 10.1161/strokeaha.111.636456] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The intraluminal suture technique for producing middle cerebral artery occlusion in rodents is the most commonly used method for modeling focal cerebral ischemia associated with clinical ischemic stroke. Synchrotron radiation angiography may provide a novel solution to directly monitor the success of middle cerebral artery occlusion. METHODS Twenty adult Sprague-Dawley rats for middle cerebral artery occlusion models were prepared randomly with different suture head silicone coating. In vivo imaging was performed at beam line BL13W1, Shanghai Synchrotron Radiation Facility, Shanghai, China. RESULTS Silicone-coated suture was superior to uncoated suture for producing consistent brain infarction. Additionally, silicone coating length was an important variable controlling the extent of the ischemic lesion: infarcts affected predominantly the caudate-putamen with large variability (<2 mm), both the cortex and caudate-putamen (2-3.3 mm), and most of the hemisphere, including the hypothalamus (>3.3 mm). CONCLUSIONS Synchrotron radiation angiography provides a useful tool to observe hemodynamic changes after middle cerebral artery occlusion, and the physical properties of suture are critical to the success of the middle cerebral artery occlusion model.
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49
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Winchester R, Minevich G, Steshenko V, Kirby B, Kane D, Greenberg DA, FitzGerald O. HLA associations reveal genetic heterogeneity in psoriatic arthritis and in the psoriasis phenotype. ACTA ACUST UNITED AC 2011; 64:1134-44. [PMID: 22006066 DOI: 10.1002/art.33415] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Rigorously ascertained cases of psoriatic arthritis in subjects presenting to a rheumatology unit were compared with cases of psoriasis in subjects presenting to a dermatology unit, where subjects with musculoskeletal features were excluded, to address 1) the extent to which the contribution of the major histocompatibility complex (MHC) to psoriatic arthritis susceptibility resembles that in psoriasis, and 2) whether MHC genes determine quantitative traits within the psoriatic arthritis phenotype. METHODS Separate discovery and validation subcohorts of patients recruited from a relatively homogeneous population were studied by sequence-based HLA typing, in which frequencies of the HLA-B and HLA-C alleles and haplotypes were compared. RESULTS In patients with psoriatic arthritis, the frequency of C*06:02 was lower than that in patients with psoriasis (28.7% versus 57.5%; P = 9.9 × 10(-12) ). Three haplotypes containing B*27:05 or B*39:01 were significantly increased in frequency in patients with psoriatic arthritis, but not in those with psoriasis. The structurally related B*39:06 allele was not increased in frequency. B*27 was associated with an interval of 0.98 years between skin and musculoskeletal disease (P = 2.05 × 10(-6) ), compared with an interval of 10.14 years for C*06. Preliminary evidence suggested that B*38:01 and B*08 may be associated with psoriatic arthritis susceptibility, and that allotypes encoding P2 pockets that bind side chains opposite in charge from those encoded by the B*27 and B*39 molecules may exert a protective role. CONCLUSION These findings suggest that the psoriasis phenotype results from two patterns of MHC effect. The first involves the classic psoriasis susceptibility gene C*06, which confers more penetrant skin disease with less prevalent and more time-dependent musculoskeletal phenotype development. The second pattern appears to be mediated by HLA-B alleles, notably B*27, and includes temporally more coincident musculoskeletal involvement that is nearly equivalent in penetrance to that of the skin disease.
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Jin K, Mao X, Xie L, Greenberg DA. Neuroglobin expression in human arteriovenous malformation and intracerebral hemorrhage. ACTA NEUROCHIRURGICA. SUPPLEMENT 2011; 111:315-9. [PMID: 21725774 DOI: 10.1007/978-3-7091-0693-8_52] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
We reported previously that Notch signaling is activated in human arteriovenous malformations (AVMs) and that intracerebral hemorrhage (ICH) in humans is accompanied by increased neurogenesis. The former phenomenon may be involved in AVM pathogenesis and the latter in the brain's response to ICH-induced injury. Here we describe increased expression of the hypoxia-inducible neuroprotective protein, neuroglobin (Ngb), in neurons surrounding unruptured AVMs and in the perihematomal region adjacent to ICH. In these disorders, as in other clinical settings, such as ischemic stroke, AVM- and ICH-induced overexpression of Ngb may be stimulated by ischemic hypoxia and may help to constrain brain injury.
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