99mTc-labeled benzothiazole and stilbene derivatives as imaging agents for Aβ plaques in cerebral amyloid angiopathy

MedChemComm ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Jianhua Jia ◽  
Mengchao Cui ◽  
Jiapei Dai ◽  
Xuedan Wang ◽  
Yu-Shin Ding ◽  
...  

99mTc-labeled probes in this study for the Aβ plaques in the blood vessels of the brain may be used as SPECT imaging agents for the diagnosis of CAA.

2020 ◽  
Author(s):  
Yuriko Tachida ◽  
Saori Miura ◽  
Rie Imamaki ◽  
Naomi Ogasawara ◽  
Hiroyuki Takuwa ◽  
...  

AbstractThe deposition of amyloid β (Aβ) in blood vessels of the brain, known as cerebral amyloid angiopathy (CAA), is observed in more than 90% of Alzheimer’s disease (AD) patients. The presence of such CAA pathology is not as evident, however, in most mouse models of AD, thereby making it difficult to examine the contribution of CAA to the pathogenesis of AD. Since blood levels of soluble amyloid precursor protein (sAPP) in rodents are less than 1% of those in humans, we hypothesized that endothelial APP expression would be markedly lower in rodents, thus providing a reason for the poorly expressed CAA pathology. Here we generated mice that specifically express human APP770 in endothelial cells. These mice exhibited an age-dependent robust deposition of Aβ in brain blood vessels but not in the parenchyma. Crossing these animals with APP knock-in mice led to an expanded CAA pathology as evidenced by increased amounts of amyloid accumulated in the cortical blood vessels. These results show that both neuronal and endothelial APP contribute cooperatively to vascular Aβ deposition, and suggest that this mouse model will be useful for studying disease mechanisms underlying CAA and for developing novel AD therapeutics.


2005 ◽  
Vol 58 (3) ◽  
pp. 348-350 ◽  
Author(s):  
Roy O. Weller ◽  
James A. R. Nicoll

2018 ◽  
Vol 89 (6) ◽  
pp. A33.3-A34
Author(s):  
Jasmin Tilling ◽  
Benjamin Trewin ◽  
Stanley Levy

IntroductionCerebral amyloid angiopathy (CAA) is a common age-related condition characterised by amyloid beta-peptide deposition affecting the medium sized cortical and leptomeningeal arteries, arterioles and capillaries. CAA-related Inflammation (CAA-I) is an increasingly recognised variant of CAA, which is thought to be due to perivascular auto-inflammation in response to amyloid deposition. We describe the clinical course of two cases of probable CAA-I.CasesA 71 year old man presented with new-onset seizures, headaches and subacute cognitive decline. MRI of the brain demonstrated confluent subcortical T2 white matter hyperintensities and cerebral oedema, with predominantly superimposed widespread cortico-subcortical micro-haemorrhages, in keeping with the diagnosis of CAA-I. A course of immunosuppresive therapy was commenced with five days of intravenous methylprednisolone, resulting in marked radiological and clinical improvement within two weeks.A 76 year old female presented with subacute cognitive dysfunction and apraxia, and transient left-sided weakness. MRI scan of the brain initially demonstrated a right temporo-occipital infarct, leading to primary treatment for stroke, but subsequently evolved to reveal diffuse multi-lobar T2 white matter hyperintensities with leptomeningeal involvement. A provisional diagnosis of CAA-I was made and following a poor clinical response to a trial of corticosteroid therapy, treatment with intravenous cyclophosphamide was commenced.ConclusionThese cases emphasise the importance of CAA-I as part of the differential diagnosis in patients presenting with symptoms of subacute cognitive decline, seizures, headaches and focal neurological deficits, given the potential for dramatic improvement with readily accessible immunosuppressive therapies.


ACS Omega ◽  
2018 ◽  
Vol 3 (10) ◽  
pp. 13089-13096 ◽  
Author(s):  
Jia Song ◽  
Xiaohui Peng ◽  
Linlin Li ◽  
Fan Yang ◽  
Xiaojun Zhang ◽  
...  

2020 ◽  
Author(s):  
Suk-Ki Chang ◽  
JeongYeong Kim ◽  
DongKyu Lee ◽  
Chang Hyun Yoo ◽  
Seokha Jin ◽  
...  

Abstract Purpose Growing evidence suggests that alterations of the cerebral microvasculature play a critical role in the pathogenesis of Alzheimer’s disease (AD). The objective of this study was to characterize and evaluate the cerebral microvascular architecture in the AD transgenic (Tg) mice model compared with non-Tg mice using brain microvascular indices obtained by MRI.Methods Seven non-Tg mice and ten 5xFAD Tg mice were scanned using a 7-T animal MRI system to measure the transverse relaxation rates of R2 and R2* before and after injection of the monocrystalline iron oxide nanoparticle contrast agent. After calculation of the relaxation rate difference of ΔR2* and ΔR2, the microvascular indices of the vessel size index (VSI), mean vessel diameter (mVD), mean vessel density (Q), mean vessel-weighted image (MvWI), and blood volume fraction (BVf) were mapped. The voxel-based analyses and regions-of-interest (ROIs)-based analyses were performed to compare the indices between the non-Tg and Tg groups.Results The BVf, mVD, VSI, and MvWI were greater in the Tg group than in the non-Tg group based on voxel comparisons. Additionally, the ROIs-based analysis showed that ΔR2*, BVf, mVD, MvWI, and VSI were increased in the Tg group compared to the non-Tg group in several brain regions. Most ROIs defined by the mouse brain atlas were not significantly different between the two groups.Conclusion We found increased microvascular indices of VSI and mVD in the Tg mice, reflecting microvascular disruption in the brain, which may be related to damages of the neurovascular unit in AD caused by cerebral amyloid angiopathy.Clinical Relevance / Application: To date, few studies have investigated the microvascular injuries of the AD brain using MRI. We suggest that investigation of cerebral microvasculature using a high-field MRI in AD would be worthwhile to elucidate the pathophysiology of cerebral amyloid angiopathy in this disease. Indeed, microvascular MRI can be a promising imaging tool for investigating early diagnosis and monitoring treatment in AD.


2012 ◽  
Vol 7 (2) ◽  
pp. 134 ◽  
Author(s):  
Octavio M Pontes-Neto ◽  
Eitan Auriel ◽  
Steven M Greenberg ◽  
◽  
◽  
...  

Cerebral amyloid angiopathy (CAA) is pathologically defined as the deposition of amyloid protein, most commonly the amyloid β peptide (Aβ), primarily within the media and adventitia of small and medium-sized arteries of the leptomeninges, cerebral and cerebellar cortex. This deposition likely reflects an imbalance between Aβ production and clearance within the brain and leads to weakening of the overall structure of brain small vessels, predisposing patients tolobar intracerebral haemorrhage (ICH), brain ischaemia and cognitive decline. CAA is associated with markers of small vessel disease, like lobar microbleeds and white matter hyperintensities on magnetic resonance imaging. Therefore, it can be now be diagnosed during life with reasonable accuracy by clinical and neuroimaging criteria. Despite the lack of a specific treatment for this condition, the detection of CAA may help in the management of patients, regarding the prevention of major haemorrhagic complications and genetic counselling. This review discusses recent advances in our understanding of the pathophysiology, detection and management of CAA.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Valentina Perosa ◽  
Leon P Munting ◽  
Whitney Freeze ◽  
Ashley A Scherlek ◽  
Anand Viswanathan ◽  
...  

Perivascular spaces (PVS) are fluid-filled spaces surrounding cerebral blood vessels. MRI-visible, supposedly enlarged, PVS in the centrum semiovale (CSO) have been associated with cerebral amyloid angiopathy (CAA). PVS enlargement may be due to perivascular clearance impairments, potentially caused by increased amyloid-β (Aβ) accumulation in the walls of vessels in the overlying cortex. We test this hypothesis, using MRI-guided histopathological examination of PVS in CAA autopsy cases. The cohort included 19 CAA (74.1±8.2y, 7F) and 5 non-CAA control cases (88.0±4.9y, 3F). Formalin-fixed hemispheres were scanned on a 3T MRI scanner, including a 500μm T2-weighted sequence. PVS enlargement was assessed in the CSO on in vivo and ex vivo MRI. In addition, local score of PVS enlargement was assessed in four pre-defined juxtacortical areas (Fig.A), using a semiquantitative score and on the corresponding histological sections (Fig.B). Severity of leptomeningeal and cortical CAA were assessed on adjacent Aβ-stained sections, using a semiquantitative scale.PVS enlargement was more severe in CAA cases compared to controls, both on in vivo and ex vivo MRI (p<0.05). PVS enlargement on ex vivo MRI positively correlated with the severity of PVS enlargement on the corresponding histopathological samples (Fig.C). Within CAA cases, the degree of PVS enlargement on ex vivo MRI was positively associated with leptomeningeal CAA severity (n=52 samples, ρ=0.35, p=0.011), but not cortical CAA severity (n=52 samples, ρ=0.10, p=0.472). These preliminary findings confirm that the degree of MRI-visible PVS in juxtacortical brain areas reflects enlargement on histopathology. Moreover, they suggest that PVS enlargement in cases with CAA corresponds to increased CAA severity in the overlying leptomeningeal vessels, possibly as a result of impaired perivascular clearance. Future directions include characterization of individual blood vessels associated with PVS enlargement.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Carson Finger ◽  
Juneyoung Lee ◽  
Diego Morales ◽  
Bharti Manwani

Introduction: Cerebral amyloid angiopathy (CAA) is one of the common causes of intracerebral hemorrhage in the elderly. It is caused by the deposition of amyloid-beta1-40 (Aβ1-40) deposition within cerebral blood vessels, especially the smooth muscle layer, that can cause cerebral microbleeds (CMBs) and cognitive impairment. We hypothesize Aβ deposition causes an innate inflammatory response characterized by an increase and activation of microglia and macrophages. This inflammation might cause CMBs, neuronal damage and cognitive decline CAA. Methods: C57BL6 Tg-SwDI male and female mice (18 months) were used as a mouse model for CAA. Age-matched wild-type (WT) mice were used as controls. Brain samples from these mice were fractionated and 23-plex cytokine multiplex was performed on the brain lysates. Data was analyzed using two sample t-test or GraphPad PRISM. Results: Our data showed that CAA increased levels of pro-inflammatory cytokines in the brain, as compared with WT mice. Multiplex analysis showed that Tg-SwDI mice had significantly higher levels of cytokines; tumor necrosis factor-α (TNF-α; 54.38 vs. 17.03 pg/ml, p=0.00207), IL-12 (70.81 vs. 53.95 pg/ml, p= 0.014), macrophage inflammatory protein-1α (MIP-1α, 113.92 vs. 16.81 pg/ml, p=3.85E-10), MIP-1β (86.15 vs. 53.43 pg/ml, p= 3.51E-09) and monocyte chemoattractant protein-1 (MCP-1, 109.46 vs. 118.53 pg/ml, p= 0.00033). Conclusion: This study highlights a monocyte/macrophage driven pro-inflammatory milieu in CAA. Recent studies using in vivo two-photon imaging and histology have found recruitment of microglia and monocytes/macrophages around induced 100 μm sized hemorrhage. The increase in these microglia is only found in Alzheimer’s patients who also had CAA and was not seen in patients with no CAA, suggesting the role of microglia in causing vascular frailty in CAA. Our study suggests that pro-inflammatory cytokines like TNF-a, IL-12, MIP-1α, MIP-1β and MCP-1 can be therapeutic targets for CAA.


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