scholarly journals Role of Purinergic Signalling in Endothelial Dysfunction and Thrombo-Inflammation in Ischaemic Stroke and Cerebral Small Vessel Disease

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 994
Author(s):  
Natasha Ting Lee ◽  
Lin Kooi Ong ◽  
Prajwal Gyawali ◽  
Che Mohd Nasril Che Mohd Nassir ◽  
Muzaimi Mustapha ◽  
...  

The cerebral endothelium is an active interface between blood and the central nervous system. In addition to being a physical barrier between the blood and the brain, the endothelium also actively regulates metabolic homeostasis, vascular tone and permeability, coagulation, and movement of immune cells. Being part of the blood–brain barrier, endothelial cells of the brain have specialized morphology, physiology, and phenotypes due to their unique microenvironment. Known cardiovascular risk factors facilitate cerebral endothelial dysfunction, leading to impaired vasodilation, an aggravated inflammatory response, as well as increased oxidative stress and vascular proliferation. This culminates in the thrombo-inflammatory response, an underlying cause of ischemic stroke and cerebral small vessel disease (CSVD). These events are further exacerbated when blood flow is returned to the brain after a period of ischemia, a phenomenon termed ischemia-reperfusion injury. Purinergic signaling is an endogenous molecular pathway in which the enzymes CD39 and CD73 catabolize extracellular adenosine triphosphate (eATP) to adenosine. After ischemia and CSVD, eATP is released from dying neurons as a damage molecule, triggering thrombosis and inflammation. In contrast, adenosine is anti-thrombotic, protects against oxidative stress, and suppresses the immune response. Evidently, therapies that promote adenosine generation or boost CD39 activity at the site of endothelial injury have promising benefits in the context of atherothrombotic stroke and can be extended to current CSVD known pathomechanisms. Here, we have reviewed the rationale and benefits of CD39 and CD39 therapies to treat endothelial dysfunction in the brain.

2015 ◽  
Vol 36 (1) ◽  
pp. 72-94 ◽  
Author(s):  
Anna Poggesi ◽  
Marco Pasi ◽  
Francesca Pescini ◽  
Leonardo Pantoni ◽  
Domenico Inzitari

The term cerebral small vessel disease (SVD) refers to a group of pathologic processes with various etiologies that affect small arteries, arterioles, venules, and capillaries of the brain. Magnetic resonance imaging (MRI) correlates of SVD are lacunes, recent small subcortical infarcts, white-matter hyperintensities, enlarged perivascular spaces, microbleeds, and brain atrophy. Endothelial dysfunction is thought to have a role in the mechanisms leading to SVD-related brain changes, and the study of endothelial dysfunction has been proposed as an important step for a better comprehension of cerebral SVD. Among available methods to assess endothelial function in vivo, measurement of molecules of endothelial origin in peripheral blood is currently receiving selective attention. These molecules include products of endothelial cells that change when the endothelium is activated, as well as molecules that reflect endothelial damage and repair. This review examines the main molecular factors involved in both endothelial function and dysfunction, and the evidence linking endothelial dysfunction with cerebral SVD, and gives an overview of clinical studies that have investigated the possible association between endothelial circulating biomarkers and SVD-related brain changes.


2018 ◽  
Vol 10 (448) ◽  
pp. eaam9507 ◽  
Author(s):  
Rikesh M. Rajani ◽  
Sophie Quick ◽  
Silvie R. Ruigrok ◽  
Delyth Graham ◽  
Sarah E. Harris ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Che Mohd Nasril Che Mohd Nassir ◽  
Mazira Mohamad Ghazali ◽  
Sabarisah Hashim ◽  
Nur Suhaila Idris ◽  
Lee Si Yuen ◽  
...  

Cerebral small vessel disease (CSVD) represents a spectrum of pathological processes of various etiologies affecting the brain microcirculation that can trigger neuroinflammation and the subsequent neurodegenerative cascade. Prevalent with aging, CSVD is a recognized risk factor for stroke, vascular dementia, Alzheimer disease, and Parkinson disease. Despite being the most common neurodegenerative condition with cerebrocardiovascular axis, understanding about it remains poor. Interestingly, modifiable risk factors such as unhealthy diet including high intake of processed food, high-fat foods, and animal by-products are known to influence the non-neural peripheral events, such as in the gastrointestinal tract and cardiovascular stress through cellular inflammation and oxidation. One key outcome from such events, among others, includes the cellular activations that lead to elevated levels of endogenous cellular-derived circulating microparticles (MPs). MPs can be produced from various cellular origins including leukocytes, platelets, endothelial cells, microbiota, and microglia. MPs could act as microthrombogenic procoagulant that served as a plausible culprit for the vulnerable end-artery microcirculation in the brain as the end-organ leading to CSVD manifestations. However, little attention has been paid on the potential role of MPs in the onset and progression of CSVD spectrum. Corroboratively, the formation of MPs is known to be influenced by diet-induced cellular stress. Thus, this review aims to appraise the body of evidence on the dietary-related impacts on circulating MPs from non-neural peripheral origins that could serve as a plausible microthrombosis in CSVD manifestation as a precursor of neurodegeneration. Here, we elaborate on the pathomechanical features of MPs in health and disease states; relevance of dietary patterns on MP release; preclinical studies pertaining to diet-based MPs contribution to disease; MP level as putative surrogates for early disease biomarkers; and lastly, the potential of MPs manipulation with diet-based approach as a novel preventive measure for CSVD in an aging society worldwide.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
James W Nelson ◽  
David Durgan ◽  
Nadim Ajami ◽  
Joseph Petrosino ◽  
Robert Bryan

The importance of a healthy gut microbiota on host physiology is becoming increasingly evident. Recent studies suggest that alterations to the microbiota can have adverse effects beyond the GI tract, and has been linked to hypertension and stroke. Thus we hypothesized that gut dysbiosis could contribute to the development of cerebral small vessel disease (CSVD). Giving merit to this hypothesis, we found that the microbiota of the spontaneously hypertensive stroke prone rat (SHRSP) is significantly different than that of WKY controls. Using 16s rRNA sequencing of bacterial DNA we found that SHRSP animals had decreases in measures of bacterial richness (p=.005) and diversity (p=.028), indicative of gut dysbiosis. Phenotypically, CSVD includes vessel remodeling, BBB breakdown and neuroinflammation. Gut dysbiosis is often associated with a leaky gut barrier that allows bacteria to enter the systemic circulation. We observed significantly greater permeability of the SHRSP colon barrier when compared to WKY (p=.026). We next sought to determine if impaired colon barrier function in SHRSP could lead to increased bacterial translocation to the periphery and ultimately to the brain. Brains were harvested from 24 week old SHRSP and WKY animals and qRT-PCR of the 16s rRNA gene was performed to detect the presence of bacteria in the brain. We discovered that SHRSP animals displayed a 50% increase in bacterial 16S rRNA load in the brain compared to WKY animals (p=.0063) confirming that bacteria are not only present in CSVD rats, but also in greater abundance than WKYs. Similarly, we found that SHRSP animals displayed a near 2-fold increase of the bacterial endotoxin LPS in the brain, as compared to WKY brain LPS levels (p=.01). Finally, to further confirm the presence of bacterial components in the brain we used immunofluorescence imaging to visualize peptidoglycan (PG), a molecule found solely in bacterial cell walls. We discovered that we could visualize the presence of PG in the brains of SHRSP animals, and note that PG was commonly observed inside microglia. We conclude from this study that SHRSP rats exhibit gut dysbiosis, gut barrier breakdown, and bacterial products in the brain. Further studies will examine how this bacterial presence contributes to the CSVD phenotypes.


2021 ◽  
pp. 1-10
Author(s):  
Yanjing Lu ◽  
Yifan Li ◽  
Qian Feng ◽  
Rong Shen ◽  
Hao Zhu ◽  
...  

<b><i>Background:</i></b> Altered white matter brain networks have been extensively studied in cerebral small vessel disease (SVD). However, there exists currently a deficiency of comprehending the performance of changes within the structural networks of the brain in cases with cerebral SVD and depression symptoms. The main aim of the present research is to study the network topology behaviors and features of rich-club organization in SVD patients using graph theory and diffusion tensor imaging (DTI) to characterize changes in the microstructure of the brain. <b><i>Methods:</i></b> DTI datasets were acquired from 26 SVD patients with symptoms of depression (SVD + D) and 26 SVD patients without symptoms of depression (SVD − D), and a series of neuropsychological assessments were completed. A structural network was created using a deterministic fiber tracking method. The analysis of rich-club was performed in company with analysis of the global network features of the network to characterize the topological properties of all subjects. <b><i>Results:</i></b> DTI data were obtained from SVD patients who manifested symptoms of depression (SVD + D) and from control SVD patients (SVD − D). In comparison with SVD − D patients, SVD + D cases demonstrated a diminished coefficient of clustering along with lower global efficiencies and longer path length characteristics. Rich-club analysis showed SVD + D patients had decreased feeder connectivity and local connectivity strengths compared to SVD − D patients. Our data also showed that the feeder connections in the brain correlated significantly with the severity of depression in SVD + D patients. <b><i>Conclusions:</i></b> Our study revealed that SVD patients with depressive symptoms have disrupted white matter networks that characteristically have reduced network efficiency compared to the networks in other SVD patients. Disrupted information interactions among the regions of nonrich-club and rich-club in SVD cases are related to the severity of depression. Our data suggest that DTI may be utilized as an appropriate biomarker for the diagnosis of depression in comorbid SVD patients.


2017 ◽  
Vol 52 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Cezary Grochowski ◽  
Jakub Litak ◽  
Piotr Kamieniak ◽  
Ryszard Maciejewski

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