- Email: [email protected]
EARLY CHRONIC TRAUMATIC ENCEPHALOPATHY IN YOUNG ATHLETES AFTER CONCUSSIVE CLOSED-HEAD IMPACT INJURY AND MOUSE MODEL OF IMPACT CONCUSSION
P628
Poster Presentations: Monday, July 25, 2016
Health Institute, Verdun, QC, Canada. Contact e-mail: monica.shin1989@ gmail.com Background: Although the signature properties of Alzheimer’s disease (AD), such as the formation of amyloid plaques, activation of inflammatory responses, and hyperphosphorylation have been well studied, the explanation illustrating a clear relationship specifically between neuroinflammation and cognitive impairment has not yet been discovered. Thus in this article, we employed the McGill-R-Thy1-APP transgenic (Tg) rat model to observe for activation of inflammatory responses and the presence of cognitive decline. We hypothesize that early expression of neuroinflammatory signals will lead to future cognitive decline in the amyloid expressing animals. Methods: Microglial activation was measured using the ligand [18F]PBR06 for PET, while cognitive performance was measured with the MWM task in 5 wild-type (Wt) and 8 Tg rats at baseline (BL; 11.5 months) and at follow-up (FU; 16 months). PBR-PET images were processed using the cerebellar grey matter as the reference region and cognitive measurement was calculated as the average times of day 3 and 4 of the water maze task. The baseline as well as the change (FU – BL) in the cognitive measurements were correlated at voxel level using “VoxelStats” toolbox to observe for the effect of group and PBR interaction on the change in the water maze performance. The PBR values were corrected for global cortical values, and t-statistical maps were generated to illustrate the regions of significance. Results: The association between baseline levels of cognition and inflammation was greater in the Tg than Wt rats in the right nucleus accumbens, whereas in the opposite was seen in the right inferior colliculus. The association between baseline levels of inflammation and change in cognition at follow-up, several regions including the left retrosplenial cortex, right hippocampus, and the right posterior commissure showed higher decrease in cognition of the Tg animals compared to the Wt (Figure 1). Conclusions: At baseline, there is no association between neuroinflammation and cognitive performance; however in more aged rats, baseline levels of PBR is able to predict cognitive decline. The results provide a framework that could potentially be applied in human studies focusing on the detrimental roles of neuroinflammation in AD.
P2-054
CELLULAR MODELING OF INFLAMMATION RELEVANT TO ALZHEIMER’S DISEASE: MOLECULAR AND CYTOKINE ANALYSIS OF HOST RESPONSES FOLLOWING CHLAMYDIAL INFECTION OF HUMAN THP-1 MONOCYTES
Christine J. Hammond, Jonathan M. Anzmann, Abhi P. Jain, Susan T. Hingley, Brian J. Balin, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA. Contact e-mail: [email protected] Background: Our previous investigations have identified an association between brain infection with Chlamydia pneumoniae (Cpn) and late-onset Alzheimer disease (AD). We have demonstrated that Cpn is detectable in AD brain tissues in a variety of cell types including neurons, glia, endothelial cells, and perivascular macrophages. In addition, Cpn has been identified within monocytes from human blood samples from geriatric patients who have demonstrated cognitive change. As we have seen Cpn infection in both peripheral cells and in autopsy brain tissues, this study sought to further understand the initiation of neuroinflammation by using our in vitro infection model. Methods: Human THP-1 monocytes were infected with Cpn to establish acute (24hr) to chronic/persistent (120 hr) infections. Host responses following infection were analyzed using ELISA for inflammatory cytokines. Molecular analysis consisted of evaluating host gene transcript changes using commercial human neuroinflammation and inflammasome real time PCR Arrays and specific changes using IDO1, IDO2, CCL2, AIM2 and IL-1beta primer sets. The infection was analyzed using immunofluorescence microscopy and real time PCR for Chlamydial gene transcripts. Results: Immunofluorescence microscopy revealed Cpn infection of the monocytes at all times post-infection with at least 50% of cells infected at any time point. Inflammatory cytokines for IL-1 beta and IL-18 were increased in infected THP-1 monocytes when compared to uninfected THP-1. Real time PCR analysis revealed upregulation of gene transcripts for numerous host inflammatory and inflammasome genes, many of which have been previously correlated to AD such as CCL2, IL-1beta, IL-6, Caspases, and NFKB1. These transcript changes were consistent with cytokine detection. Conclusions: Infection of THP-1 monocytes with Chlamydia pneumoniae results in unregulated host gene transcripts and increased cytokine production similar to those seen in sporadic late-onset Alzheimer disease samples. These findings support the AD infection hypothesis whereby infection can be a prominent initiating component in AD neurodegeneration. P2-055
EARLY CHRONIC TRAUMATIC ENCEPHALOPATHY IN YOUNG ATHLETES AFTER CONCUSSIVE CLOSED-HEAD IMPACT INJURY AND MOUSE MODEL OF IMPACT CONCUSSION
Lee E. Goldstein1,2, Chad A. Tagge1, Andrew M. Fisher1, Olga Minaeva1, Amanda Gaudreau1, Xiao-Lei Zhang3, Chirag Upreti3, Maria Ericsson4, Mark W. Wojnarowicz2, Noel F. Casey2, Juliet A. Moncaster2, Christopher Nowinski2, Robert Cantu2, Sudad Saman5, Garth F. Hall5, Victor E. Alvarez2,6, Asami Kondo4, Andy Anderson7, Ronel Veksler8, Kristen Onos9, Haiyan Lu10, Vlad Senatorov11, Bertrand R. Huber6, Thor D. Stein2,6, Yorghos Tripodis12, Daniela Kaufer11, Kun Ping Lu4, Robin O. Cleveland13, Gareth Howell9, Alon Friedman8, Richard Ransohoff10, Bruce T. Lamb10, William C. Moss7, Patric K. Stanton3, Ann C. McKee2,6, 1Boston University, Boston, MA, USA; 2 Boston University School of Medicine, Boston, MA, USA; 3New York
Poster Presentations: Monday, July 25, 2016 Medical College, Valhalla, NY, USA; 4Harvard Medical School, Boston, MA, USA; 5University of Massachusetts Lowell, Lowell, MA, USA; 6VA Boston Healthcare System, Jamaica Plain, MA, USA; 7Lawrence Livermore National Laboratory, Livermore, CA, USA; 8Ben-Gurion University, Beersheba, Israel; 9The Jackson Laboratory, Bar Harbor, ME, USA; 10 Cleveland Clinic, Cleveland, OH, USA; 11University of California, Berkeley, Berkeley, CA, USA; 12Boston University School of Public Health, Boston, MA, USA; 13University of Oxford, Oxford, United Kingdom. Contact e-mail: [email protected] Background: The mechanisms by which head injury induces concussion, traumatic brain injury (TBI), and chronic traumatic encephalopathy (CTE) are not known. Methods: New impact neurotrauma mouse model that utilizes momentum transfer to induce traumatic head acceleration and neurological signs of concussion. Human and mouse brain neuropathology, biomechanics and kinematic analyses, neurobehavioral testing, phosphorylated tau protein neurochemistry, hippocampal and medial prefrontal cortical electrophysiology, Evans blue and dynamic contrast-enhanced MRI neuroimaging, flow cytometry, simulation modelling. Results: We detected early CTE-linked pathologies in postmortem brains from young athletes in the post-acute period after closed-head impact injury. Unanesthetized mice subjected to lateral closed-head impact injury exhibited contralateral limb weakness, impaired gait and balance, and locomotor abnormalities that recapitulate neurological signs and temporal course of concussion in humans. Brains from impact-injured mice demonstrated microvasculopathy, phosphorylated tau proteinopathy (cis-p-tau, pS202-tau), blood-brain barrier (BBB) dysfunction, and infiltrative and intrinsic neuroinflammation. CTE pathologies emerged acutely in ipsilateral cortex and co-localized with extravasated serum protein detectable by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in vivo. We detected early and persistent impairments in hippocampal axonal conduction and medial prefrontal cortical long-term potentiation (LTP) of synaptic neurotransmission in both hemispheres distant from the injury. Neither the presence nor severity of concussion correlated with head kinematics, acute injury, or chronic sequelae. Moreover, concussion was observed only after impact but not blast under conditions of comparable head kinematics. Simulation modeling revealed that impact generates asymmetric force point loading in the brain subjacent to the contact site and sheer stress spread that propagates circumferentially to distant brain regions before onset of macroscopic head motion. During impact, point loading and sheer stress spread is associated with concussion, whereas during blast, diffuse loading with minimal shear is not. By contrast, structural injury, CTE pathologies, and persistent functional distrubances are triggered by slower-acting inertial forces generated in both injuries. Conclusions: The mechanisms subserving concussion are independent of those leading to acute TBI and CTE. Concussion is neither necessary nor sufficient for acute brain injury or chronic sequelae. By contrast, closedhead impact, with or without concussion, is sufficient to trigger brain pathologies and functional deficits associated with TBI and CTE.
P2-057
AMPHIREGULIN MEDIATES APOE’S ASSOCIATION WITH DEMENTIA, AND ETHNICITY MODERATES BOTH ASSOCIATIONS
Safa Al-Rubaye1, Raymond F. Palmer1, Donald R. Royall1,2, 1University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; 2South Texas Veterans Health Administration Geriatric Research Education and Clinical Center (GRECC), San Antonio, TX, USA. Contact e-mail: [email protected]
P629
Background: The latent variable “d” (for “dementia”) is a dementia-specific phenotype. The majority of d’s variance were found far only in Non-Hispanic Whites (NHW). We recently identified amphiregulin (AREG) as the unique mediator of APOE’s specific association with d. We assessed ethnicity’s effect on their associations in a large and longitudinal cohort, the Texas Alzheimer’s Research and Care Consortium (TARCC). Methods: We used the “dEQ” homolog, previously shown to be ethnicity equivalent, among n ¼ 3072 TARCC participants: Hispanic Mexican-Americans (MA) (n ¼ 1113) and NHW (n ¼ 1958). dEQ is indicated by COWA, LMII, VRI, DST, targets IADL, and is adjusted for age, gender and education. dEQ constructed in Wave 2 data was output as a composite “dEQ-score”. Serum amphiregulin (AREG) was tested as a mediator of APOE’s direct effect on Wave 2 dEQ. This model was adjusted for age, gender, education, ethnicity, depression, serum HgbA1c, and HCY. Findings were replicated in two random subgroups. We stratified the cohort on ethnicity, and retested APOE’s association with Wave 2 dEQ in each ethnic subgroup. The final mediation paths are temporally sequential and arguably causal. Results: The Mediation Direct Path Model (APOE > dEQ) had excellent fit [c2¼ 3.47 (6), p ¼0.75; CFI ¼ 1.0; RMSEA ¼ 0.00]. Independently of covariates, APOEe4 burden was significantly directly associated with dEQ (r ¼ 0.28, p < 0.001). AREG Mediation Model also had excellent fit [c2 ¼ 56.56 (19), p < 0.001; CFI ¼ 0.990; RMSEA ¼ 0.025]. AREG mediated 6.0% of APOEe4 burden’s direct effect on dEQ (z ¼ 6.24, p ¼ 0.001). This effect replicated across random subsets [c2 difference ¼ 4.8 (3), p ¼ 0.10]. APOEe4 burden was significantly directly associated with Wave 2 dEQ in NHW (r ¼ 0.31, p < 0.001), but their
Poster Presentations: Monday, July 25, 2016
Health Institute, Verdun, QC, Canada. Contact e-mail: monica.shin1989@ gmail.com Background: Although the signature properties of Alzheimer’s disease (AD), such as the formation of amyloid plaques, activation of inflammatory responses, and hyperphosphorylation have been well studied, the explanation illustrating a clear relationship specifically between neuroinflammation and cognitive impairment has not yet been discovered. Thus in this article, we employed the McGill-R-Thy1-APP transgenic (Tg) rat model to observe for activation of inflammatory responses and the presence of cognitive decline. We hypothesize that early expression of neuroinflammatory signals will lead to future cognitive decline in the amyloid expressing animals. Methods: Microglial activation was measured using the ligand [18F]PBR06 for PET, while cognitive performance was measured with the MWM task in 5 wild-type (Wt) and 8 Tg rats at baseline (BL; 11.5 months) and at follow-up (FU; 16 months). PBR-PET images were processed using the cerebellar grey matter as the reference region and cognitive measurement was calculated as the average times of day 3 and 4 of the water maze task. The baseline as well as the change (FU – BL) in the cognitive measurements were correlated at voxel level using “VoxelStats” toolbox to observe for the effect of group and PBR interaction on the change in the water maze performance. The PBR values were corrected for global cortical values, and t-statistical maps were generated to illustrate the regions of significance. Results: The association between baseline levels of cognition and inflammation was greater in the Tg than Wt rats in the right nucleus accumbens, whereas in the opposite was seen in the right inferior colliculus. The association between baseline levels of inflammation and change in cognition at follow-up, several regions including the left retrosplenial cortex, right hippocampus, and the right posterior commissure showed higher decrease in cognition of the Tg animals compared to the Wt (Figure 1). Conclusions: At baseline, there is no association between neuroinflammation and cognitive performance; however in more aged rats, baseline levels of PBR is able to predict cognitive decline. The results provide a framework that could potentially be applied in human studies focusing on the detrimental roles of neuroinflammation in AD.
P2-054
CELLULAR MODELING OF INFLAMMATION RELEVANT TO ALZHEIMER’S DISEASE: MOLECULAR AND CYTOKINE ANALYSIS OF HOST RESPONSES FOLLOWING CHLAMYDIAL INFECTION OF HUMAN THP-1 MONOCYTES
Christine J. Hammond, Jonathan M. Anzmann, Abhi P. Jain, Susan T. Hingley, Brian J. Balin, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA. Contact e-mail: [email protected] Background: Our previous investigations have identified an association between brain infection with Chlamydia pneumoniae (Cpn) and late-onset Alzheimer disease (AD). We have demonstrated that Cpn is detectable in AD brain tissues in a variety of cell types including neurons, glia, endothelial cells, and perivascular macrophages. In addition, Cpn has been identified within monocytes from human blood samples from geriatric patients who have demonstrated cognitive change. As we have seen Cpn infection in both peripheral cells and in autopsy brain tissues, this study sought to further understand the initiation of neuroinflammation by using our in vitro infection model. Methods: Human THP-1 monocytes were infected with Cpn to establish acute (24hr) to chronic/persistent (120 hr) infections. Host responses following infection were analyzed using ELISA for inflammatory cytokines. Molecular analysis consisted of evaluating host gene transcript changes using commercial human neuroinflammation and inflammasome real time PCR Arrays and specific changes using IDO1, IDO2, CCL2, AIM2 and IL-1beta primer sets. The infection was analyzed using immunofluorescence microscopy and real time PCR for Chlamydial gene transcripts. Results: Immunofluorescence microscopy revealed Cpn infection of the monocytes at all times post-infection with at least 50% of cells infected at any time point. Inflammatory cytokines for IL-1 beta and IL-18 were increased in infected THP-1 monocytes when compared to uninfected THP-1. Real time PCR analysis revealed upregulation of gene transcripts for numerous host inflammatory and inflammasome genes, many of which have been previously correlated to AD such as CCL2, IL-1beta, IL-6, Caspases, and NFKB1. These transcript changes were consistent with cytokine detection. Conclusions: Infection of THP-1 monocytes with Chlamydia pneumoniae results in unregulated host gene transcripts and increased cytokine production similar to those seen in sporadic late-onset Alzheimer disease samples. These findings support the AD infection hypothesis whereby infection can be a prominent initiating component in AD neurodegeneration. P2-055
EARLY CHRONIC TRAUMATIC ENCEPHALOPATHY IN YOUNG ATHLETES AFTER CONCUSSIVE CLOSED-HEAD IMPACT INJURY AND MOUSE MODEL OF IMPACT CONCUSSION
Lee E. Goldstein1,2, Chad A. Tagge1, Andrew M. Fisher1, Olga Minaeva1, Amanda Gaudreau1, Xiao-Lei Zhang3, Chirag Upreti3, Maria Ericsson4, Mark W. Wojnarowicz2, Noel F. Casey2, Juliet A. Moncaster2, Christopher Nowinski2, Robert Cantu2, Sudad Saman5, Garth F. Hall5, Victor E. Alvarez2,6, Asami Kondo4, Andy Anderson7, Ronel Veksler8, Kristen Onos9, Haiyan Lu10, Vlad Senatorov11, Bertrand R. Huber6, Thor D. Stein2,6, Yorghos Tripodis12, Daniela Kaufer11, Kun Ping Lu4, Robin O. Cleveland13, Gareth Howell9, Alon Friedman8, Richard Ransohoff10, Bruce T. Lamb10, William C. Moss7, Patric K. Stanton3, Ann C. McKee2,6, 1Boston University, Boston, MA, USA; 2 Boston University School of Medicine, Boston, MA, USA; 3New York
Poster Presentations: Monday, July 25, 2016 Medical College, Valhalla, NY, USA; 4Harvard Medical School, Boston, MA, USA; 5University of Massachusetts Lowell, Lowell, MA, USA; 6VA Boston Healthcare System, Jamaica Plain, MA, USA; 7Lawrence Livermore National Laboratory, Livermore, CA, USA; 8Ben-Gurion University, Beersheba, Israel; 9The Jackson Laboratory, Bar Harbor, ME, USA; 10 Cleveland Clinic, Cleveland, OH, USA; 11University of California, Berkeley, Berkeley, CA, USA; 12Boston University School of Public Health, Boston, MA, USA; 13University of Oxford, Oxford, United Kingdom. Contact e-mail: [email protected] Background: The mechanisms by which head injury induces concussion, traumatic brain injury (TBI), and chronic traumatic encephalopathy (CTE) are not known. Methods: New impact neurotrauma mouse model that utilizes momentum transfer to induce traumatic head acceleration and neurological signs of concussion. Human and mouse brain neuropathology, biomechanics and kinematic analyses, neurobehavioral testing, phosphorylated tau protein neurochemistry, hippocampal and medial prefrontal cortical electrophysiology, Evans blue and dynamic contrast-enhanced MRI neuroimaging, flow cytometry, simulation modelling. Results: We detected early CTE-linked pathologies in postmortem brains from young athletes in the post-acute period after closed-head impact injury. Unanesthetized mice subjected to lateral closed-head impact injury exhibited contralateral limb weakness, impaired gait and balance, and locomotor abnormalities that recapitulate neurological signs and temporal course of concussion in humans. Brains from impact-injured mice demonstrated microvasculopathy, phosphorylated tau proteinopathy (cis-p-tau, pS202-tau), blood-brain barrier (BBB) dysfunction, and infiltrative and intrinsic neuroinflammation. CTE pathologies emerged acutely in ipsilateral cortex and co-localized with extravasated serum protein detectable by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in vivo. We detected early and persistent impairments in hippocampal axonal conduction and medial prefrontal cortical long-term potentiation (LTP) of synaptic neurotransmission in both hemispheres distant from the injury. Neither the presence nor severity of concussion correlated with head kinematics, acute injury, or chronic sequelae. Moreover, concussion was observed only after impact but not blast under conditions of comparable head kinematics. Simulation modeling revealed that impact generates asymmetric force point loading in the brain subjacent to the contact site and sheer stress spread that propagates circumferentially to distant brain regions before onset of macroscopic head motion. During impact, point loading and sheer stress spread is associated with concussion, whereas during blast, diffuse loading with minimal shear is not. By contrast, structural injury, CTE pathologies, and persistent functional distrubances are triggered by slower-acting inertial forces generated in both injuries. Conclusions: The mechanisms subserving concussion are independent of those leading to acute TBI and CTE. Concussion is neither necessary nor sufficient for acute brain injury or chronic sequelae. By contrast, closedhead impact, with or without concussion, is sufficient to trigger brain pathologies and functional deficits associated with TBI and CTE.
P2-057
AMPHIREGULIN MEDIATES APOE’S ASSOCIATION WITH DEMENTIA, AND ETHNICITY MODERATES BOTH ASSOCIATIONS
Safa Al-Rubaye1, Raymond F. Palmer1, Donald R. Royall1,2, 1University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; 2South Texas Veterans Health Administration Geriatric Research Education and Clinical Center (GRECC), San Antonio, TX, USA. Contact e-mail: [email protected]
P629
Background: The latent variable “d” (for “dementia”) is a dementia-specific phenotype. The majority of d’s variance were found far only in Non-Hispanic Whites (NHW). We recently identified amphiregulin (AREG) as the unique mediator of APOE’s specific association with d. We assessed ethnicity’s effect on their associations in a large and longitudinal cohort, the Texas Alzheimer’s Research and Care Consortium (TARCC). Methods: We used the “dEQ” homolog, previously shown to be ethnicity equivalent, among n ¼ 3072 TARCC participants: Hispanic Mexican-Americans (MA) (n ¼ 1113) and NHW (n ¼ 1958). dEQ is indicated by COWA, LMII, VRI, DST, targets IADL, and is adjusted for age, gender and education. dEQ constructed in Wave 2 data was output as a composite “dEQ-score”. Serum amphiregulin (AREG) was tested as a mediator of APOE’s direct effect on Wave 2 dEQ. This model was adjusted for age, gender, education, ethnicity, depression, serum HgbA1c, and HCY. Findings were replicated in two random subgroups. We stratified the cohort on ethnicity, and retested APOE’s association with Wave 2 dEQ in each ethnic subgroup. The final mediation paths are temporally sequential and arguably causal. Results: The Mediation Direct Path Model (APOE > dEQ) had excellent fit [c2¼ 3.47 (6), p ¼0.75; CFI ¼ 1.0; RMSEA ¼ 0.00]. Independently of covariates, APOEe4 burden was significantly directly associated with dEQ (r ¼ 0.28, p < 0.001). AREG Mediation Model also had excellent fit [c2 ¼ 56.56 (19), p < 0.001; CFI ¼ 0.990; RMSEA ¼ 0.025]. AREG mediated 6.0% of APOEe4 burden’s direct effect on dEQ (z ¼ 6.24, p ¼ 0.001). This effect replicated across random subsets [c2 difference ¼ 4.8 (3), p ¼ 0.10]. APOEe4 burden was significantly directly associated with Wave 2 dEQ in NHW (r ¼ 0.31, p < 0.001), but their