“Cerebral small vessel disease is a key feature of vascular dementia”

Project Title: Failure of drainage of fluid from the brain along the walls of blood vessels in vascular dementia 

Funding: Stroke Association Priority Programme Award (vascular dementia) – £245,198.00

Duration: 2017 – 2020

Overview: Cerebral small vessel disease (SVD) is key feature of vascular dementia, radiologically defined by the presence of white matter hyperintensities, lacunar infarcts, microbleeds and perivascular spaces.  Cerebral arteriolosclerosis resulting in loss of elasticity and segmental disorganisation of the arterial wall leads to damage of the deep white matter.  The primary functions of penetrating and perforating cerebral arteries supplying blood and drainage of fluid and solutes from the parenchyma along intramural perivascular pathways along the arterial basement membranes are impaired.  In this project, using animal models and post-mortem brain tissue from stroke survivors with SVD (CogFAST study) along with light sheet 3D microscopy and post-mortem MRI, we will assess the immunocytochemical pattern of distribution of AQP4, α-dystrobrevin and β-dystroglycan.  We will then test the hypotheses that 1) disruption in the anchoring system of the basement membranes such as that observed in α-dystrobrevin knock-out mice and 2) disruption of gliovascular end feet tracked by aquaporin 4 (AQP4) knock-out mice there is failure of perivascular clearance of fluid from the deep gray matter and the corpus callosum.  Our aim is to demonstrate that failure of perivascular drainage of fluid from the brain is a mechanism underlying SVD and this could be targeted therapeutically.

Researcher: Matthew MacGregor Sharp

“Cerebral small vessel disease is a key feature of vascular dementia”

Project Title: Failure of drainage of fluid from the brain along the walls of blood vessels in vascular dementia 

Funding: Stroke Association Priority Programme Award (vascular dementia) – £245,198.00

Duration: 2017 – 2020

Overview: Cerebral small vessel disease (SVD) is key feature of vascular dementia, radiologically defined by the presence of white matter hyperintensities, lacunar infarcts, microbleeds and perivascular spaces.  Cerebral arteriolosclerosis resulting in loss of elasticity and segmental disorganisation of the arterial wall leads to damage of the deep white matter.  The primary functions of penetrating and perforating cerebral arteries supplying blood and drainage of fluid and solutes from the parenchyma along intramural perivascular pathways along the arterial basement membranes are impaired.  In this project, using animal models and post-mortem brain tissue from stroke survivors with SVD (CogFAST study) along with light sheet 3D microscopy and post-mortem MRI, we will assess the immunocytochemical pattern of distribution of AQP4, α-dystrobrevin and β-dystroglycan.  We will then test the hypotheses that 1) disruption in the anchoring system of the basement membranes such as that observed in α-dystrobrevin knock-out mice and 2) disruption of gliovascular end feet tracked by aquaporin 4 (AQP4) knock-out mice there is failure of perivascular clearance of fluid from the deep gray matter and the corpus callosum.  Our aim is to demonstrate that failure of perivascular drainage of fluid from the brain is a mechanism underlying SVD and this could be targeted therapeutically.

Researcher: Matthew MacGregor Sharp

“The meninges are the interface between cerebrospinal fluid and interstitial fluid”

Project TitleThe selective permeability of leptomeninges

Duration: 2017 – 2018

Overview: The meninges are the interface between cerebrospinal fluid and interstitial fluid, with controversy regarding their permeability. Through a partnership with molecular microbiologists (Prof Myron Christodoulides) we are investigating the exact properties of the leptomeninges with particular emphasis on their selective permeability. This is relevant for a) the transfer of Aβ from the parenchyma to the CSF where it is measured as a biomarker for disease progression and b) the pathology of complications of subarachnoid haemorrhage.  

Researcher: In collaboration with Professor Myron Christodoulides

“The meninges are the interface between cerebrospinal fluid and interstitial fluid”

Project TitleThe selective permeability of leptomeninges

Duration: 2017 – 2018

Overview: The meninges are the interface between cerebrospinal fluid and interstitial fluid, with controversy regarding their permeability. Through a partnership with molecular microbiologists (Prof Myron Christodoulides) we are investigating the exact properties of the leptomeninges with particular emphasis on their selective permeability. This is relevant for a) the transfer of Aβ from the parenchyma to the CSF where it is measured as a biomarker for disease progression and b) the pathology of complications of subarachnoid haemorrhage.  

Researcher: In collaboration with Professor Myron Christodoulides

“the motive force for perivascular clearance is provided by spontaneous vasomotion”

Project Title: In vivo MRI imaging of the motive force driving intramural perivascular clearance

Funding: EPSRC Doctoral Prize

Duration: 2018 – 2019

Overview: Based on results from mathematical modelling we now know that the motive force for perivascular clearance is provided by spontaneous vasomotion resulting from the intrinsic contractions of pericytes and cerebrovascular smooth muscle cells and not by the pulsations derived from cardiac cycle (Dr Alexandra Diem, Prof Neil Bressloff). Collaborations are in place with senior neuroradiologists in University College London and Leiden, The Netherlands to demonstrate in vivo in real time using MRI, the features of the motive force for efficient intramural perivascular clearance and correlate this with findings in different stages of Alzheimer’s disease and mild cognitive impairment. This could be the first marker for impaired clearance of cerebral interstitial fluid in humans..

Researcher: Roxana Aldea

“the motive force for perivascular clearance is provided by spontaneous vasomotion”

Project Title: In vivo MRI imaging of the motive force driving intramural perivascular clearance

Funding: EPSRC Doctoral Prize

Duration: 2018 – 2019

Overview: Based on results from mathematical modelling we now know that the motive force for perivascular clearance is provided by spontaneous vasomotion resulting from the intrinsic contractions of pericytes and cerebrovascular smooth muscle cells and not by the pulsations derived from cardiac cycle (Dr Alexandra Diem, Prof Neil Bressloff). Collaborations are in place with senior neuroradiologists in University College London and Leiden, The Netherlands to demonstrate in vivo in real time using MRI, the features of the motive force for efficient intramural perivascular clearance and correlate this with findings in different stages of Alzheimer’s disease and mild cognitive impairment. This could be the first marker for impaired clearance of cerebral interstitial fluid in humans.

Researcher: Roxana Aldea

“flow of Aβ over astrocytes expressing different forms of ApoE results in morphological alterations to the astrocytes”

Project TitleDevelopment of an in vitro perivascular clearance system

Duration: 2015 – 2019

Funding: BBSRC CASE PhD Studentship with Kirkstall Ltd – “Development of an in vitro perivascular clearance system“. £95,042.

Overview: Using a novel Quasi Vivo in vitro system developed by Kirkstall Ltd and mouse astrocytes that express humanised ApoE, (collaboration with David Holtzman, Washington University, USA), we aim to test the hypothesis that flow of Aβ over astrocytes expressing different forms of ApoE results in morphological alterations to the astrocytes expressing ApoE4, compared to those expressing ApoE2 or ApoE3. Using coated coverslips, the astrocytes are plated and left to adhere for 24 hours before being loaded into the QV500 chamber or 24 well plate for static experiments. A solution of astrocyte growth medium supplemented with 100nM Aβ 1-40 is circulated around the system for 24 hours. The coverslip is removed and fixed in 4% PFA, immunostained and examined by confocal microscopy. We have already optimised the system for testing the activity of Quasi Vivo and concluded that the Quasi Vivo system has no significant toxic effect on the growth or viability of the cells when cells grown under flow were compared with static controls. There appears to be a decrease in cell number when Aβ is applied to ApoE4 astrocytes under flow. We have also shown that there are morphological changes to ApoE4 astrocytes when Aβ is applied that are further enhanced when combined with flow. These changes are not seen in ApoE2 or ApoE3 astrocytes. We also observed that Aβ appears to be concentrated where there are clusters of cells, though this has only been seen in ApoE3 astrocytes. This work suggests that the dynamics of interactions between  Aβ and astrocytes are dependent on their APOE genotype and this is likely to contribute to the reduced clearance of Aβ in APOE4 individuals.  

Researcher: Abby Keable

“flow of Aβ over astrocytes expressing different forms of ApoE results in morphological alterations to the astrocytes”

Project TitleDevelopment of an in vitro perivascular clearance system

Duration: 2015 – 2019

Funding: BBSRC CASE PhD Studentship with Kirkstall Ltd – “Development of an in vitro perivascular clearance system“. £95,042.

Overview: Using a novel Quasi Vivo in vitro system developed by Kirkstall Ltd and mouse astrocytes that express humanised ApoE, (collaboration with David Holtzman, Washington University, USA), we aim to test the hypothesis that flow of Aβ over astrocytes expressing different forms of ApoE results in morphological alterations to the astrocytes expressing ApoE4, compared to those expressing ApoE2 or ApoE3. Using coated coverslips, the astrocytes are plated and left to adhere for 24 hours before being loaded into the QV500 chamber or 24 well plate for static experiments. A solution of astrocyte growth medium supplemented with 100nM Aβ 1-40 is circulated around the system for 24 hours. The coverslip is removed and fixed in 4% PFA, immunostained and examined by confocal microscopy. We have already optimised the system for testing the activity of Quasi Vivo and concluded that the Quasi Vivo system has no significant toxic effect on the growth or viability of the cells when cells grown under flow were compared with static controls. There appears to be a decrease in cell number when Aβ is applied to ApoE4 astrocytes under flow. We have also shown that there are morphological changes to ApoE4 astrocytes when Aβ is applied that are further enhanced when combined with flow. These changes are not seen in ApoE2 or ApoE3 astrocytes. We also observed that Aβ appears to be concentrated where there are clusters of cells, though this has only been seen in ApoE3 astrocytes. This work suggests that the dynamics of interactions between  Aβ and astrocytes are dependent on their APOE genotype and this is likely to contribute to the reduced clearance of Aβ in APOE4 individuals.  

Researcher: Abby Keable

“loss of perivascular innervation by cholinergic neurons leads to dysfunctional regulation of vascular tone”

Project Title: Innervation of cerebral arteries is key to maintenance of efficient clearance and flow

Funding: Alzheimer’s Research UK – Co-PI “Targeting perivascular innervation and vascular tone for improved clearance of ß-amyloid from the brain“. £88,440

Duration: 2015 – 2018

Overview: This project, funded by Alzheimer’s Research UK in collaboration with Dr Cheryl Hawkes (Open University), tests the hypothesis that loss of perivascular innervation by cholinergic neurons leads to dysfunctional regulation of vascular tone, thereby reducing the motive force for perivascular drainage of Aβ leading to a worsening of cerebral amyloid angiopathy.

Researcher: Maureen Gatherer In collaboration with Dr Cheryl Hawkes

“loss of perivascular innervation by cholinergic neurons leads to dysfunctional regulation of vascular tone”

Project Title: Innervation of cerebral arteries is key to maintenance of efficient clearance and flow

Funding: Alzheimer’s Research UK – Co-PI “Targeting perivascular innervation and vascular tone for improved clearance of ß-amyloid from the brain“. £88,440

Duration: 2015 – 2018

Overview: This project, funded by Alzheimer’s Research UK in collaboration with Dr Cheryl Hawkes (Open University), tests the hypothesis that loss of perivascular innervation by cholinergic neurons leads to dysfunctional regulation of vascular tone, thereby reducing the motive force for perivascular drainage of Aβ leading to a worsening of cerebral amyloid angiopathy.

Researcher: Maureen Gatherer In collaboration with Dr Cheryl Hawkes

“exposure to a high fat diet during development and early life leads to the remodelling of the neurovascular unit “

Project TitleDoes maternal high fat diet lead to dementia?

Funding: Rosetrees Trust Project grant – “The effect of maternal high fat on the clearance of interstitial fluid from the brain“. £25,000.

Duration: 2017 – 2018

Overview: In this project we test the hypothesis that exposure to a high fat diet during development and early life, leads to the remodelling of the neurovascular unit and reduces the efficiency of Aβ clearance from the brain, leading to increased CAA severity. A mouse model of pre- and postnatal high fat diet exposure will be established by feeding female mice (C57Bl/6), either a standard (21% kcal fat) or high fat (45% kcal fat) diet for 4 weeks before conception and during gestation and lactation. At weaning, male and female offspring will be fed either a normal or high fat to generate 4 groups of experimental mice. We will create a separate group of female pregnant mice that will be treated with Metformin to assess whether this therapeutic agent is effective in halting the pathological process. We aim to demonstrate that simple measures like improving the diet of pregnant mothers, managing hypercholesterolaemia, diabetes will prevent or delay the onset of dementia.

Researcher: Regan Doherty, Matthew MacGregor Sharp and Antigoni Manousopoulou. In collaboration with Dr Felino Cagampang

“exposure to a high fat diet during development and early life leads to the remodelling of the neurovascular unit “

Project TitleDoes maternal high fat diet lead to dementia?

Funding: Rosetrees Trust Project grant – “The effect of maternal high fat on the clearance of interstitial fluid from the brain“. £25,000.

Duration: 2017 – 2018

Overview: In this project we test the hypothesis that exposure to a high fat diet during development and early life, leads to the remodelling of the neurovascular unit and reduces the efficiency of Aβ clearance from the brain, leading to increased CAA severity. A mouse model of pre- and postnatal high fat diet exposure will be established by feeding female mice (C57Bl/6), either a standard (21% kcal fat) or high fat (45% kcal fat) diet for 4 weeks before conception and during gestation and lactation. At weaning, male and female offspring will be fed either a normal or high fat to generate 4 groups of experimental mice. We will create a separate group of female pregnant mice that will be treated with Metformin to assess whether this therapeutic agent is effective in halting the pathological process. We aim to demonstrate that simple measures like improving the diet of pregnant mothers, managing hypercholesterolaemia, diabetes will prevent or delay the onset of dementia.

Researcher: Regan Doherty, Matthew MacGregor Sharp and Antigoni Manousopoulou. In collaboration with Dr Felino Cagampang