- Email: [email protected]
BLOOD ALPHA-SYNUCLEIN IN ALZHEIMER'S DISEASE
Poster Presentations: Sunday, July 16, 2017 P1-165
BLOOD ALPHA-SYNUCLEIN IN ALZHEIMER’S DISEASE
Gaush Talat, Dr. C. D. Sinha, Magadh University, Gaya, India. Contact e-mail: [email protected] Background: The accumulation of a-synuclein aggregates is the hallmark of Parkinson’s disease while amyloid aggregates for Alzheimer’s Disease. Numerous studies reported crosstalk of these proteinopathies. Methods: Serum was extracted from AD(n¼40), MCI (n¼20) and age matched healthy control(n¼40) at two time points. Alpha-synuclein level was quantified with ELISA and confirmed with western blot. Results: Mean a-synuclein was significantly higher in 25% patients of Alzheimer’s Disease while only in 10% cases of MCI. The difference between in significant cases with control group was 1.5-fold. And this increase of alpha-synuclein was not correlated with disease duration, onset age of disease or MCI score. Conclusions: Overexpressed Levels of a-synuclein in 25% patients of Alzheimer’s Disease, denotes its confirmation in Alzheimer’s Disease involvement with unknown pathophysiology.
P1-166
THE ANTI-ASTHMATIC DRUG MONTELUKAST ALTERS MICROGLIA PHENOTYPE AND SYNUCLEOPATHY, AND RESTORES LEARNING AND MEMORY IN AN ANIMAL MODEL OF LEWY BODY DEMENTIA
Julia Marschallinger1, Barbara Altendorfer2, Nadine Pillichshammer2, Garnweidner-Raith Julia2, Edward Rockenstein3, Eliezer Masliah4, Ludwig Aigner1, 1Paracelsus Medical University Salzburg, Salzburg, Austria; 2PMU Salzburg, Salzburg, Austria; 3UCSD, La Jolla, CA, USA; 4 University of California, San Diego, La Jolla, CA, USA. Contact e-mail: j. [email protected] Background: Neurodegenerative diseases are associated with
increased neuroinflammation. Leukotrienes are small lipid mediators of neuroinflammatory processes, and thus, leukotriene signaling might be a therapeutic target for neurodegenerative disease such as AD, PD, or Lewy body dementia (LBD). Methods: 6-month old PDGF-promoter-alpha-synuclein (PDGF-a-syn) Dline transgenic mice (abbreviated D-line), an animal model for LBD, were treated per oral gavage daily over a period of 42 days with montelukast (10 mg/kg), an approved leukotriene receptor antagonist for the treatment of asthma. Behavioral analyses (Morris Water Maze – learning and memory) of the animals were performed between days 28 and 40. After transcardial perfusion of the mice on day 42, histological analyses of the hippocampus (proliferation, cell survival, neuroinflammation, alpha-synuclein load) were assessed. Results: We observed elevated levels of 5-LOX protein, the rate limiting enzyme in leukotriene production, in the hippocampus of 6 months old PDGF-promoter-alpha-synuclein (PDGF-a-syn) mice, an animal model for LBD. D-line animals exhibited elevated levels of neuroinflammation, and most importantly, had learning and memory deficits. Treatment of 6 months old Dline mice for 6 weeks with the leukotriene receptor antagonist Montelukast fully restored learning and memory to a level comparable to WT animals without having any adverse effects regardless of the phenotype. Montelukast significantly reduced microglia soma size (a typical morphological surrogate for microglia activation) and reduced the particle size of the phagosomal marker CD68 suggesting either a reduced microglial activity or a restoration of the
P307
phagocytic / lysosomal activity, which is otherwise disturbed in microglia of the aged and of the neurodegenerative brain. Moreover, the Montelukast treatment altered the synucleopathy in the D-line mice. Conclusions: In summary, the leukotriene receptor antagonist Montelukast was highly efficient in restoring cognitive function in an animal model of LBD, most likely but not necessarily limited through its anti-inflammatory action on microglia. This work paves the road for a further development of Montelukast for the treatment neurodegenerative diseases.
P1-167
AAV-MEDIATED EXPRESSION OF HUMAN LDLR MARKEDLY REDUCES AMYLOID DEPOSITION IN A MOUSE MODEL OF AMYLOID-b AMYLOIDOSIS
Aimin Li1, Hong Jiang1, Kathryn Lefton1, Grace O. Robinson1, Patrick M. Sullivan2, Joseph D. Roh1, David M. Holtzman3,4,5, 1Washington University School of Medicine, Saint Louis, MO, USA; 2Duke University School of Medicine, Durham, NC, USA; 3Hope Center for Neurological Disorders, Saint Louis, MO, USA; 4Washington University School of Medicine, St. Louis, MO, USA; 5Knight Alzheimer’s Disease Research Center, St. Louis, MO, USA. Contact e-mail: [email protected] Background: Apolipoprotein E (APOE) is the strongest genetic risk
factor for Alzheimer’s disease (AD). Evidence suggests that apoE level and apoE isoform both influence amyloid-b (Ab) accumulation in the brain and play critical roles in AD pathogenesis. The low density lipoprotein receptor (LDLR) is a major cell-surface receptor that regulates the level of apoE in the brain. LDLR transgenic mice that overexpress murine LDLR have significantly decreased apoE levels in the brain as well as greatly reduced Ab plaques and enhanced Ab clearance. These results suggest that increasing LDLR levels may represent a novel AD treatment strategy. However, whether postnatal expression of human LDLR in mice that express human apoE4 and that develop Ab plaques can reduce Ab accumulation in the brain is unknown. Methods: APPPS1-21 transgenic mice were crossed to human apoE4 knock-in mice and used in these experiments. All pups were injected with phosphate buffered saline (PBS) at post-natal day (P) 0 as the vehicle control group, with AAV2/8-GFP at P0 as viral vector control, or with AAV2/8-human LDLR as the experimental group. All mice (APP+/0 E4+/+) were sacrificed at 4 months of age. The brains were collected post-perfusion for histological and biochemical assessment. Results: Mice treated with AAV2/8LDLR had significantly reduced brain soluble apoE levels comparing to the PBS and AAV2/8-GFP control mice. AAV2/8LDLR treated mice had significantly decreased insoluble Ab40 and Ab42 levels compared to the PBS and AAV2/8-GFP treated control. Furthermore, mice treated with AAV2/8-LDLR had significantly decreased amyloid deposition compared to PBS and AAV2/ 8-GFP control mice. Soluble apoE levels significantly correlated with amyloid plaque load and insoluble Ab concentration. Conclusions: Postnatal expression of human LDLR by AAV significantly lowered apoE levels in APPPS1-21; apoE4 knock-in mice. Expression of human LDLR also markedly inhibited amyloid deposition and decreased insoluble Ab levels. These results together with our lab’s previous transgenic mouse LDLR studies clearly shows that LDLR is a key receptor that can modulate brain apoE levels as well as Ab pathology. Increasing LDLR expression in the adult brain may be an important target to consider in prevention and treatment of the Ab-related component of AD.
BLOOD ALPHA-SYNUCLEIN IN ALZHEIMER’S DISEASE
Gaush Talat, Dr. C. D. Sinha, Magadh University, Gaya, India. Contact e-mail: [email protected] Background: The accumulation of a-synuclein aggregates is the hallmark of Parkinson’s disease while amyloid aggregates for Alzheimer’s Disease. Numerous studies reported crosstalk of these proteinopathies. Methods: Serum was extracted from AD(n¼40), MCI (n¼20) and age matched healthy control(n¼40) at two time points. Alpha-synuclein level was quantified with ELISA and confirmed with western blot. Results: Mean a-synuclein was significantly higher in 25% patients of Alzheimer’s Disease while only in 10% cases of MCI. The difference between in significant cases with control group was 1.5-fold. And this increase of alpha-synuclein was not correlated with disease duration, onset age of disease or MCI score. Conclusions: Overexpressed Levels of a-synuclein in 25% patients of Alzheimer’s Disease, denotes its confirmation in Alzheimer’s Disease involvement with unknown pathophysiology.
P1-166
THE ANTI-ASTHMATIC DRUG MONTELUKAST ALTERS MICROGLIA PHENOTYPE AND SYNUCLEOPATHY, AND RESTORES LEARNING AND MEMORY IN AN ANIMAL MODEL OF LEWY BODY DEMENTIA
Julia Marschallinger1, Barbara Altendorfer2, Nadine Pillichshammer2, Garnweidner-Raith Julia2, Edward Rockenstein3, Eliezer Masliah4, Ludwig Aigner1, 1Paracelsus Medical University Salzburg, Salzburg, Austria; 2PMU Salzburg, Salzburg, Austria; 3UCSD, La Jolla, CA, USA; 4 University of California, San Diego, La Jolla, CA, USA. Contact e-mail: j. [email protected] Background: Neurodegenerative diseases are associated with
increased neuroinflammation. Leukotrienes are small lipid mediators of neuroinflammatory processes, and thus, leukotriene signaling might be a therapeutic target for neurodegenerative disease such as AD, PD, or Lewy body dementia (LBD). Methods: 6-month old PDGF-promoter-alpha-synuclein (PDGF-a-syn) Dline transgenic mice (abbreviated D-line), an animal model for LBD, were treated per oral gavage daily over a period of 42 days with montelukast (10 mg/kg), an approved leukotriene receptor antagonist for the treatment of asthma. Behavioral analyses (Morris Water Maze – learning and memory) of the animals were performed between days 28 and 40. After transcardial perfusion of the mice on day 42, histological analyses of the hippocampus (proliferation, cell survival, neuroinflammation, alpha-synuclein load) were assessed. Results: We observed elevated levels of 5-LOX protein, the rate limiting enzyme in leukotriene production, in the hippocampus of 6 months old PDGF-promoter-alpha-synuclein (PDGF-a-syn) mice, an animal model for LBD. D-line animals exhibited elevated levels of neuroinflammation, and most importantly, had learning and memory deficits. Treatment of 6 months old Dline mice for 6 weeks with the leukotriene receptor antagonist Montelukast fully restored learning and memory to a level comparable to WT animals without having any adverse effects regardless of the phenotype. Montelukast significantly reduced microglia soma size (a typical morphological surrogate for microglia activation) and reduced the particle size of the phagosomal marker CD68 suggesting either a reduced microglial activity or a restoration of the
P307
phagocytic / lysosomal activity, which is otherwise disturbed in microglia of the aged and of the neurodegenerative brain. Moreover, the Montelukast treatment altered the synucleopathy in the D-line mice. Conclusions: In summary, the leukotriene receptor antagonist Montelukast was highly efficient in restoring cognitive function in an animal model of LBD, most likely but not necessarily limited through its anti-inflammatory action on microglia. This work paves the road for a further development of Montelukast for the treatment neurodegenerative diseases.
P1-167
AAV-MEDIATED EXPRESSION OF HUMAN LDLR MARKEDLY REDUCES AMYLOID DEPOSITION IN A MOUSE MODEL OF AMYLOID-b AMYLOIDOSIS
Aimin Li1, Hong Jiang1, Kathryn Lefton1, Grace O. Robinson1, Patrick M. Sullivan2, Joseph D. Roh1, David M. Holtzman3,4,5, 1Washington University School of Medicine, Saint Louis, MO, USA; 2Duke University School of Medicine, Durham, NC, USA; 3Hope Center for Neurological Disorders, Saint Louis, MO, USA; 4Washington University School of Medicine, St. Louis, MO, USA; 5Knight Alzheimer’s Disease Research Center, St. Louis, MO, USA. Contact e-mail: [email protected] Background: Apolipoprotein E (APOE) is the strongest genetic risk
factor for Alzheimer’s disease (AD). Evidence suggests that apoE level and apoE isoform both influence amyloid-b (Ab) accumulation in the brain and play critical roles in AD pathogenesis. The low density lipoprotein receptor (LDLR) is a major cell-surface receptor that regulates the level of apoE in the brain. LDLR transgenic mice that overexpress murine LDLR have significantly decreased apoE levels in the brain as well as greatly reduced Ab plaques and enhanced Ab clearance. These results suggest that increasing LDLR levels may represent a novel AD treatment strategy. However, whether postnatal expression of human LDLR in mice that express human apoE4 and that develop Ab plaques can reduce Ab accumulation in the brain is unknown. Methods: APPPS1-21 transgenic mice were crossed to human apoE4 knock-in mice and used in these experiments. All pups were injected with phosphate buffered saline (PBS) at post-natal day (P) 0 as the vehicle control group, with AAV2/8-GFP at P0 as viral vector control, or with AAV2/8-human LDLR as the experimental group. All mice (APP+/0 E4+/+) were sacrificed at 4 months of age. The brains were collected post-perfusion for histological and biochemical assessment. Results: Mice treated with AAV2/8LDLR had significantly reduced brain soluble apoE levels comparing to the PBS and AAV2/8-GFP control mice. AAV2/8LDLR treated mice had significantly decreased insoluble Ab40 and Ab42 levels compared to the PBS and AAV2/8-GFP treated control. Furthermore, mice treated with AAV2/8-LDLR had significantly decreased amyloid deposition compared to PBS and AAV2/ 8-GFP control mice. Soluble apoE levels significantly correlated with amyloid plaque load and insoluble Ab concentration. Conclusions: Postnatal expression of human LDLR by AAV significantly lowered apoE levels in APPPS1-21; apoE4 knock-in mice. Expression of human LDLR also markedly inhibited amyloid deposition and decreased insoluble Ab levels. These results together with our lab’s previous transgenic mouse LDLR studies clearly shows that LDLR is a key receptor that can modulate brain apoE levels as well as Ab pathology. Increasing LDLR expression in the adult brain may be an important target to consider in prevention and treatment of the Ab-related component of AD.