Search Results for: La scansione cerebrale può diagnosticare il morbo di Alzheimer

Circulation, Volume 150, Issue Suppl_1, Page A4146706-A4146706, November 12, 2024. Background:The endothelium plays a major role in preventing thrombosis. Aging leads to a hypercoagulable state with increased procoagulant factors without accompanying rise in anticoagulant factors, shifting the balance to a prothrombotic profile. This increases the risk for conditions such as stroke or myocardial infarction. The mediator/s of this change remains unknown. Medin is a 50 amino acid cleavage product of MFGE8, accumulates in the vasculature with aging and is the most common human amyloid. Vascular medin burden is increased in vascular dementia, Alzheimer’s disease and aortic aneurysms. Medin was shown to induce endothelial and smooth muscle dysfunction and endothelial pro-inflammatory activation. Its role in aging-associated prothrombotic activation is unknown.Aim:To determine the effect of medin on human brain microvascular endothelial cells (HBMVECs) expression and function of thrombomodulin (a transmembrane glycoprotein that is a major anticoagulant through its interaction with thrombin leading to activation of protein C and S which in turn degrades factors Va and VIIIa) and HBMVEC expression of plasminogen activator inhibitor-1 (PAI-1) and tissue factor (major procoagulant proteins).Methods:Primary HBMVECs (passages 6-8) were exposed for 20 hours to physiologic doses of recombinant human medin (1 or 5 uM) and gene and protein expression of thrombomodulin, PAI-1 and tissue factor were measured using rtPCR or Western blot, respectively. In separate experiments, assessment of thrombomodulin function was determined by exposing HBMVECs for 20 hours to medin, after which human protein C (0.2 uM) and α-thrombin (10 nM) were added for 1 hour and amount of activated protein C in media was measured using ELISA.Results:Physiologic dose of medin (5 uM) given to HBMVECs resulted in reduced gene and protein expression of thrombomodulin (Fig. 1), increased gene and protein expression of PAI-1 (Fig. 2), and modest increased protein, but not gene expression of tissue factor (Fig. 3). Medin exposure also reduced HBMVEC ability to convert protein C to activated protein C in the presence of thrombin.Conclusions:Medin reduced HBMVEC production of anticoagulant protein thrombomodulin and increased protein expression of procoagulant proteins PAI-1 and tissue factor. Medin is a potential novel mediator of aging-associated hypercoagulability and could be a promising target in thrombotic diseases such as stroke.

Circulation, Volume 150, Issue Suppl_1, Page A4142250-A4142250, November 12, 2024. Introduction:Circulating progenitor cells (CPC’s) are mononuclear stem cells which originate in the bone marrow, and circulate in the blood, playing a role in promoting vascular regeneration and healing. Previous studies have shown associations between lower levels of CPC’s and increased all-cause mortality, MACE, and atherosclerosis. Additionally, those with cognitive disorders such as Alzheimer’s disease have been shown to have reduced levels of CPC’s, and some association between CPC’s and cognitive decline has been shown. Clinical surrogates for cognitive decline include a lower Montreal Cognitive Assessment (MoCA) score, and an increase in white matter hyperintensities (WMH) on MRI. We hypothesize that reduced circulating EPCs are associated with a lower MoCA score and an increased number of white matter hyperintensities (WMH) on MRI.Methods:In 181 participants (40.3% male, 41.4% Black) with and without mild cognitive impairment, CPCs were enumerated by flow cytometry as CD45medmononuclear cells expressing CD34 and co-expression with either CD133, chemokine CXC motif receptor 4 (CXCR4), or vascular endothelial growth factor receptor-2 (VEGF2R). Participants were followed for four years and underwent neuropsychiatric testing and MRI imaging. MoCA testing was used to evaluate multiple domain cognitive function. Diffusion weighted MRI was used to evaluate for WMH indicating microvascular damage. Linear regression modeling was used to determine the cross-sectional association between CPC’s and both the MoCA score and burden of WMH after adjusting for age, gender, race, body mass index, history of heart failure, and history of chronic kidney disease.Results:Lower levels of CD34/VEGF2R were associated with lower MoCA scores (β=1.31, p=0.025) and more WMH (β= -2109.1, p=0.011) when comparing first and fourth quartile of CPC concentration. Additionally, decreased CD34/133 and CD34/CXCR4 were associated with an increased burden of WMH (β=-3491.1, p=0.029 and β= -2419.8, p=0.012) when first and fourth quartiles were compared.Conclusions:Lower CPC counts of CD34 subsets were associated with worse performance on MoCA and more white matter hyperintensities on MRI, demonstrating that lower endothelial regenerative capacity may lead to decreased cognition and cognitive decline.

Circulation, Volume 150, Issue Suppl_1, Page A4119913-A4119913, November 12, 2024. Background:Medin is one of the most common amyloidogenic proteins and accumulates in the vasculature with aging. Vascular medin accumulation is associated with Alzheimer’s disease, vascular dementia and aortic aneurysms.In vitro, medin has been shown to induce endothelial proinflammatory activation and inex vivohuman cerebral arterial tissue, medin induces both endothelial and smooth muscle dysfunction. The role of medin in vascular smooth muscle (VSMC) activation remains unknown.Aim:The aim of the study is to determine using gene transcription assay whether medin induces VSMC activation and phenotypic transformation.Methods:Human brain vascular smooth muscle cells (HBVSMCs, passages 6-10) were exposed to medin at doses observed in human tissues (0, 0.5, 1 and 5 υM) for 20 hours and reverse transcription polymerase chain reaction (rtPCR) was used to quantify gene expression of proinflammatory factors (interleukin (IL)-6, IL-8, IL-1b) and structural and enzyme proteins associated with VSMC phenotypic transformation (ACTA2, MYH11 and NOX4). In separate experiments, HBVSMCs were exposed to vehicle, medin 5 υM without or with small molecule NFκB inhibitor RO106-9920 (10 υM) or NLGM1 nanoliposome (70% phosphatidylcholine, 25% cholesterol, 5% monosialoganglioside, 100 υg/mL, agent shown to reverse medin-induced endothelial dysfunction and proinflammatory activation).Results:Medin induced a dose-dependent increase in gene expression of IL-6, IL-8 and IL-1b but did not alter gene expression of ACTA2, MYH11 and NOX4 (Fig. 1). Co-treatment of medin with RO106-9920 and NLGM1 showed a trend (not statistically significant) of reduced IL-6 and IL-8 (Fig. 2).Conclusions:Physiologic doses of medin induced pro-inflammatory activation of HBVSMCs but did not affect gene expression of structural proteins (ACTA2 and MYH11) and enzyme (NOX4) involved in VSMC phenotypic transformation. Although the mechanisms behind this effect remains to be explored, results suggest that medin may be an important mediator of aging-associated vascular inflammation.

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New England Journal of Medicine, Volume 391, Issue 17, Page 1660-1661, October 31, 2024.

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