Subarachnoid haemorrhage leads to accumulation of Ab in the cortical arterioles:

Matthew Myers, MMedSc

In collaboration with Ian Galea (neurology) and Diederik Bulters (neurosurgery)


Our new and yet unpublished data demonstrate that the motive force for efficient clearance of solutes along the walls of blood vessels is provided by vasomotion, which consists of the spontaneous series of contractions of vascular smooth muscle cells, propagated from the arterioles towards the leptomeningeal arteries. As such, the disturbance in the tone and the vasoconstriction induced by an overlying subarachnoid haemorrhage would lead to impaired clearance of solutes in the cortical arteries that are branches of the vessels where the haemorrhage occurs. This study tests the hypothesis that a subarachnoid haemorrhge results in the deposition of Ab in the cortical arteries underlying the haemorrhage.

Hyperhomocystaeinaemia leads to a failure of perivascular clearance of Ab:

Karis Hodgson, BMedSc

In collaboration with Prof Donna Wilcock, University of Kentucky, USA


Hyperhomocystaeinaemia (HHCy, induced mainly by low vitamin B levels) is a risk factor for Alzheimer’s disease. A novel model of HHCy developed by our collaborator Prof Donna Wilcock in the University of Kentucky USA displays all features of small vessel disease. When HHCy is induced in a mouse model of Alzheimer’s disease, there is a significant deposition of amyloid in the walls of blood vessels. We are testing the hypothesis that HHCy results in modifications of the pathways for drainage of fluid from the walls of blood vessels and a failure of perivascular drainage of fluid from the brain.

Maternal Low Protein Diet leads to morphological and biochemical modifications of cerebrovascular basement membranes:

Ben Burwood, Joanna Gould

In collaboration with Dr Sandrine Willaime-Morawek, Prof Tom Fleming


In this project we test the hypothesis that a maternal diet low in fat leads to modifications of the proteoglycans and glycoproteins that make up the cerebrovascular basement membranes, resulting in a failure of perivascular clearance of fluid from the brain.

Markers of lymphatic vessels in the brain parenchyma:

Tom Wand, Masters in Medical Sciences


In this project, using human tissue from the Newcastle Brain Tissue Resource, we assess the pattern of immunostaining of LYVE-1, a marker of lymphatic endothelia, in the brain.

Does maternal high fat diet lead to dementia?

Matthew MacGregor Sharp and Antigoni Manousopoulou

In collaboration with Dr Felino Cagampang


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.

A novel tool to study perivascular lymphatic drainage of Amyloid-beta:

Abby Keable PhD student


  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.

Astrocytes that express Apolipoprotein E4 isoforms are smaller and proliferate less well compared to astrocytes that express the apolipoproteins E2 or E3:

Abby Keable PhD student 

Ronan O’Neill, Masters in Medical Sciences student


 Apart from increasing age, possession of Apolipoprotein E4 (APOE4) is the strongest risk factor for Alzheimer’s disease (AD). Apolipoproteins are key to the transport of cholesterol and are synthesised by astrocytes in the brain. Deposition of amyloid-beta (Ab) peptides in the walls of arteries is a hallmark of AD and reflects a failure of clearance of Ab from the brain. We have demonstrated that fluid and soluble Ab are eliminated from the brain along intramural perivascular pathways that consist of basement membranes within the walls of capillaries and arteries. These pathways for elimination become compromised with ageing and with possession of APOE4 and clearance of Ab fails.

In the present project, using cells from transgenic mice that express APOE2/3/4, we seek to demonstrate for the first time the morphological changes in the astrocytes and the pattern of expression of the different components of the the extracellular matrix. The Delphi system is ideal for testing these hypotheses, as it combines scanning electron microscopy that allows the visualisation of morphological features of the cells, with fluorescence microscopy identifying the immunofluorescence for markers of extracellular matrix.

A Mathematical Analysis of the Driving Force of Perivascular Lymphatic Drainage in the Brain:

Alexandra K. Diem & Roxana Aldea


  The observation that perivascular lymphatic drainage in the brain occurs in the reverse direction of the blood flow has for a long time been puzzling for researchers. While arterial pulsations have been suggested as the driving force for the drainage of soluble proteins such as Aß, it did not explain the directionality of the flow. Our model implements a simple valve mechanism that can explain the reverse flow of ISF, which is based on realistic structural assumptions. The findings have potential implications for AD research in the search for preventive medication.

Using this model it can be shown analytically that a net reverse flow in the PVS cannot be achieved without a valve. Therefore the implementation of a valve mechanism via conformational changes of the BM proteins is justified. The use of the valve mechanism leads to a net reverse drainage in the PVS and therefore our model provides a possible explanation of the reverse solute drainage in the brain, which is based on realistic assumptions.

In this study a mathematical model of perivascular lymphatic drainage using a flap-like valve mechanism is introduced, which only allows for unidirectional flow. The results of this model suggest that such a valve can promote net reverse flow in the perivascular spaces (PVS) and that this valve may be realised by conformational changes of the BM proteins.

Our model is based on Darcy’s Law using a nonlinear permeability function to describe a valve mechanism. The BM is very narrow (100 nm) and therefore it is reasonable to assume thin film flow, which, together with the continuity equation, forms the governing equations of the model. The flow is driven by a travelling wave on the boundary of the ISF and artery, which models the heart-rate driven pulsation of arteries.

High Resolution 3D Imaging of Cerebral Blood Vessels:

Matthew MacGregor Sharp


Using serial block-face scanning electron microscopy (SBEM) we are imaging brain tissue to elucidate how the cerebral vasculature differs in ultrastructure and conformation in different regions of the brain.

We are currently using a FEI Quanta 250 SEM in 3View mode (Gatan Inc) to generate high resolution three-dimensional images of mouse cerebral vasculature in grey and white matter regions.

Lymphatic clearance of the interstitial and cerebrospinal fluids of the brain:

Nazira Albargothy


The lymphatic clearance pathways of the brain are different compared to the other organs of the body and have been the subject of heated debates. Drainage of brain extracellular fluids, particularly interstitial fluid (ISF) and cerebrospinal fluid (CSF), is not only important for volume regulation, but also for removal of waste products such as amyloid beta (Aβ). CSF plays a special role in clinical medicine, as it is available for analysis of biomarkers for Alzheimer’s disease. Despite the lack of a complete anatomical and physiological picture of the communications between the subarachnoid space (SAS) and the brain parenchyma, it is often assumed that Aβ is cleared from the cerebral ISF into the CSF. The direction of flow, the anatomical structures involved and the driving forces remain elusive, with partially conflicting data in literature. The presence of Aβ in the glia limitans in Alzheimer’s disease suggests a direct communication of ISF with CSF. There is also the well-described pathology of cerebral amyloid angiopathy (CAA) associated with the failure of perivascular drainage of Aβ.

We are performing simultaneous stereotaxic injections of fluorescent tracers and nanoparticles into mouse brain parenchyma (ISF) and cistern magna (CSF) and visualising their movement over different time points using novel fluorescent and electron microscopy techniques.

The significance of Aquaporin 4 to perivascular lymphatic drainage:

Maureen Gatherer

Raisah Owasil, Masters in Medical Sciences


Aquaporin 4 is a molecule involved in water transport across astrocyte end feet. Experimental studies suggest that it has a role in clearance of interstitial fluid.

The aim of this study is to characterise the pattern of immunostaining of aquaporin across different stages of cognitive decline of human brains. The hypothesis is that in young, old and Alzheimer’s disease there is the same percentage area stained with aquaporin 4 but the distribution of aquaporin 4 relative to the profile of blood vessels and morphology of the astrocytes is different in different disease states.

We will also perform a qualitative analysis of cerebral capillary ultrastructure from aquaporin 4 knock-out mice (AQP4 KO), compared to normal mice and to transgenic mice that are a model of cerebral amyloid angiopathy (Tg 5X FAD mice). We will test the hypothesis that a lack of aquaporin 4 results in thinner basement membranes.

Biochemical composition of perivascular lymphatic drainage pathways:

Antigoni Manousopoulou


  Proteomics, a relatively recent scientific field, allows us to examine in an un-targeted fashion the relative expression of a large number of proteins in a certain biological system under different conditions. Unlike the traditional hypothesis-driven scientific approaches, proteomics is a hypothesis-generating tool. Our state-of-the-art proteomics methodologies include isobaric labelling approaches and multiple dimensions of liquid chromatography combined with tandem mass spectrometry. By using isobaric labelling, we are able to compare up to eight different biological conditions in a single multiplex experiment. 

The aim of our study is to examine the global proteomic profile of leptomeningeal arteries derived from young and old controls and patients with cerebral amyloid angiopathy (CAA).

We chose to apply our global proteomics approach to these specimens in order to examine in an unbiased way how the proteomic profile of brain vessels changes as a result of normal ageing as opposed to the pathological accumulation of amyloid beta in the walls of leptomeningeal arteries. The differentially expressed proteins will be interrogated using in silico bioinformatics tools to unveil biological processes being affected by ageing or CAA. This hypothesis-generating pipeline could help us gain a further insight in the pathophysiology of CAA compared to normal ageing but also highlight novel therapeutic targets.

Differences in the structure of the walls of cerebral arteries in the white matter compared to grey matter. Significance for Alzheimer’s disease.

Matthew MacGregor Sharp

Richard Cumpsty and Theo Criswell, Masters in Medical Sciences


The deposition of amyloid-β (Aβ) in the walls of cortical arteries is a major hallmark of cerebral amyloid angiopathy and Alzheimer’s disease. There are no current imaging markers specific for arterial deposition of Aβ, but recent clinical and imaging studies suggest that the severity of cerebrovascular deposits of Aβ correlates with the dilated perivascular spaces observed in the subcortical white matter. As arteries penetrate the cortex from the subarachnoid space, they gain a layer of pia mater that adheres to the wall of the artery, in direct contact with the tortuous extracellular spaces in the gray matter. It is unclear if this arrangement is maintained in the white matter.

In this study we hypothesise that, within the white matter there are two layers of leptomeninges and a perivascular space, providing the anatomical basis for dilated perivascular spaces.

Differences in the pattern of drainage of fluid from the white matter compared to the grey matter:

Matthew MacGregor Sharp


  The anatomical pathways of drainage from the white matter have not been described and we anticipate differences compared to the pattern of drainage from the grey matter, as we have already demonstrated anatomical and physiological variation in the pattern of drainage of fluid from different regions of grey matter. The anatomy of the perivascular compartment also appears to be different between grey matter and white matter (work presented at the Winter Meeting of the Anatomical Society, Cambridge 2015, Richard Cumpsty, Masters student and 1st prize winner of junior investigator poster presentation). From our studies so far, we know that the pattern of perivascular drainage of soluble material from the parenchyma is different from that of particles. .

We have demonstrated the convective influx/glymphatic distribution of nanoparticles from the CSF along glial-pial basement membranes, which is relevant for conditions such as subarachnoid haemorrhage, in which convective influx of blood results in complications that increase mortality in patients. Based on these observations, the proposed study tests the following hypotheses:

  1. interstitial fluid of the brain parenchyma does not reach the dural lymphatics;
  2. fluid from the grey matter normally drains along capillaries and arteries, whereas fluid from the white matter drains along capillaries, arteries and veins towards the subarachnoid space and does not reach the dural lymphatics.
2017 - 2020

Vascular dementia: failure of fluid drainage from cerebral white matter:

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.

Matthew MacGregor Sharp

2017 - 2018

The selective permeability of leptomeninges:

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.

In collaboration with Professor Myron Christodoulides

2017 - 2018

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

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.

Roxana Aldea, PhD student

2017

Maternal Low Protein Diet leads to morphological and biochemical modifications of cerebrovascular basement membranes:

In this project we test the hypothesis that a maternal diet low in fat leads to modifications of the proteoglycans and glycoproteins that make up the cerebrovascular basement membranes, resulting in a failure of perivascular clearance of fluid from the brain.

Ben Burwood, Joanna Gould. In collaboration with Dr Sandrine Willaime-Morawek, Prof Tom Fleming

2017

Markers of lymphatic vessels in the brain parenchyma:

In this project, using human tissue from the Newcastle Brain Tissue Resource, we assess the pattern of immunostaining of LYVE-1, a marker of lymphatic endothelia, in the brain.

Tom Wand, Masters in Medical Sciences

2017

Does maternal high fat diet lead to dementia?

n 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.

Matthew MacGregor Sharp and Antigoni Manousopoulou. In collaboration with Dr Felino Cagampang

2016 - 2018

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

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: Mrs Maureen Gatherer

Maureen Gatherer. In collaboration with Dr Cheryl Hawkes

2016 - 2017

Regional differences in the ultrastructure of cerebral blood vessels. Significance for cerebral small vessel disease and vascular cognitive impairment:

Cerebral small vessel disease (SVD) is characterised by neuroimaging features including dilated perivascular spaces (DPVS) and white matter hyperintensities (WMH) which are associated with cognitive impairment. DPVS exist within the white matter (WM) but are absent from cortical grey matter (GM). Differences in the arrangement of leptomeningeal cells around blood vessels may underlie this regional specificity. We hypothesised that one leptomeningeal layer exists around cortical GM arterioles and two layers around WM vessels, providing the anatomical basis for DPVS.

One cause of WMH is periventricular venous collagenosis (PVC) which describes the build-up of concentric layers of collagen around post-capillary venules in the periventricular white matter (PVWM). PVC is a compensatory response to shear stress on venule walls caused by abnormal extension of the arterial pulse-wave into the venous system. The exclusivity of PVC to the PVWM may be explained by ultrastructural differences in the expression of intramural cells (pericytes, smooth muscle cells) which constitute the limited pulse-wave-attenuating properties of venules. We hypothesised that intramural cell expression is lower in PVWM venules compared to superficial WM venules, increasing their susceptibility to PVC.

Using transmission electron microscopy, we are analysing the ultrastructure of blood vessels in the cortical GM, subcortical WM and basal ganglia of an intracardially perfused 12-year old Beagle brain (supplied by Invicro, USA).

Theodore Criswell, Master of Medical Sciences Student,
Matthew MacGregor Sharp

2016 - 2017

Subarachnoid haemorrhage leads to accumulation of Ab in the cortical arterioles:

Our new and yet unpublished data demonstrate that the motive force for efficient clearance of solutes along the walls of blood vessels is provided by vasomotion, which consists of the spontaneous series of contractions of vascular smooth muscle cells, propagated from the arterioles towards the leptomeningeal arteries. As such, the disturbance in the tone and the vasoconstriction induced by an overlying subarachnoid haemorrhage would lead to impaired clearance of solutes in the cortical arteries that are branches of the vessels where the haemorrhage occurs. This study tests the hypothesis that a subarachnoid haemorrhge results in the deposition of Ab in the cortical arteries underlying the haemorrhage.

Matthew Myers, MMedSc. In collaboration with Ian Galea (neurology) and Diederik Bulters (neurosurgery)

2016 - 2017

Hyperhomocystaeinaemia leads to a failure of perivascular clearance of Ab:

Hyperhomocystaeinaemia (HHCy, induced mainly by low vitamin B levels) is a risk factor for Alzheimer’s disease. A novel model of HHCy developed by our collaborator Prof Donna Wilcock in the University of Kentucky USA displays all features of small vessel disease. When HHCy is induced in a mouse model of Alzheimer’s disease, there is a significant deposition of amyloid in the walls of blood vessels. We are testing the hypothesis that HHCy results in modifications of the pathways for drainage of fluid from the walls of blood vessels and a failure of perivascular drainage of fluid from the brain.

Karis Hodgson, BMedSc In collaboration with Prof Donna Wilcock, University of Kentucky, USA

2016 - 2017

Differences in the structure of the walls of cerebral arteries in the white matter compared to grey matter. Significance for Alzheimer’s disease:

The deposition of amyloid-β (Aβ) in the walls of cortical arteries is a major hallmark of cerebral amyloid angiopathy and Alzheimer’s disease. There are no current imaging markers specific for arterial deposition of Aβ, but recent clinical and imaging studies suggest that the severity of cerebrovascular deposits of Aβ correlates with the dilated perivascular spaces observed in the subcortical white matter. As arteries penetrate the cortex from the subarachnoid space, they gain a layer of pia mater that adheres to the wall of the artery, in direct contact with the tortuous extracellular spaces in the gray matter. It is unclear if this arrangement is maintained in the white matter. In this study we hypothesise that, within the white matter there are two layers of leptomeninges and a perivascular space, providing the anatomical basis for dilated perivascular spaces.

Matthew MacGregor Sharp. Richard Cumpsty and Theo Criswell, Masters in Medical Sciences.

2016

High resolution 3D imaging of cerebral blood vessels:

Using serial block-face scanning electron microscopy (SBEM) we are imaging brain tissue to elucidate how the cerebral vasculature differs in ultrastructure and conformation in different regions of the brain. We are currently using a FEI Quanta 250 SEM in 3View mode (Gatan Inc) to generate high resolution three-dimensional images of mouse cerebral vasculature in grey and white matter regions.

Matthew MacGregor Sharp

2015 - 2019

Development of an in vitro perivascular clearance system:

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

Abby Keable PhD student

2014 - 2017

Lymphatic clearance of the interstitial and cerebrospinal fluids of the brain:

The lymphatic clearance pathways of the brain are different compared to the other organs of the body and have been the subject of heated debates. Drainage of brain extracellular fluids, particularly interstitial fluid (ISF) and cerebrospinal fluid (CSF), is not only important for volume regulation, but also for removal of waste products such as amyloid beta (Aβ). CSF plays a special role in clinical medicine, as it is available for analysis of biomarkers for Alzheimer’s disease. Despite the lack of a complete anatomical and physiological picture of the communications between the subarachnoid space (SAS) and the brain parenchyma, it is often assumed that Aβ is cleared from the cerebral ISF into the CSF. The direction of flow, the anatomical structures involved and the driving forces remain elusive, with partially conflicting data in literature. The presence of Aβ in the glia limitans in Alzheimer’s disease suggests a direct communication of ISF with CSF. There is also the well-described pathology of cerebral amyloid angiopathy (CAA) associated with the failure of perivascular drainage of Aβ.

We are performing simultaneous stereotaxic injections of fluorescent tracers and nanoparticles into mouse brain parenchyma (ISF) and cistern magna (CSF) and visualising their movement over different time points using novel fluorescent and electron microscopy techniques.

Nazira Albargothy PhD student

2013 - 2017

Biochemical composition of perivascular lymphatic drainage pathways:

Proteomics, a relatively recent scientific field, allows us to examine in an un-targeted fashion the relative expression of a large number of proteins in a certain biological system under different conditions. Unlike the traditional hypothesis-driven scientific approaches, proteomics is a hypothesis-generating tool. Our state-of-the-art proteomics methodologies include isobaric labelling approaches and multiple dimensions of liquid chromatography combined with tandem mass spectrometry. By using isobaric labelling, we are able to compare up to eight different biological conditions in a single multiplex experiment. 

The aim of our study is to examine the global proteomic profile of leptomeningeal arteries derived from young and old controls and patients with cerebral amyloid angiopathy (CAA).

We chose to apply our global proteomics approach to these specimens in order to examine in an unbiased way how the proteomic profile of brain vessels changes as a result of normal ageing as opposed to the pathological accumulation of amyloid beta in the walls of leptomeningeal arteries. The differentially expressed proteins will be interrogated using in silico bioinformatics tools to unveil biological processes being affected by ageing or CAA. This hypothesis-generating pipeline could help us gain a further insight in the pathophysiology of CAA compared to normal ageing but also highlight novel therapeutic targets.

Our proteomic analyses in humans and experimental studies highlighted the potential for Clusterin and Tissue Inhibitor of Metalloproteinases to be facilitators of intramural perivascular clearance. We are collaborating with Prof John Fryer, Mayo Clinica, USA is to test the potential for Clusterin as a therapeutic agent for restoring IPAD.

Antigoni Manousopoulou. In collaboration with Prof John Fryer, Mayo Clinica, USA.