scholarly journals Molecular Mechanisms of Neuroimmune Crosstalk in the Pathogenesis of Stroke

2021 ◽  
Vol 22 (17) ◽  
pp. 9486
Author(s):  
Yun Hwa Choi ◽  
Collin Laaker ◽  
Martin Hsu ◽  
Peter Cismaru ◽  
Matyas Sandor ◽  
...  

Stroke disrupts the homeostatic balance within the brain and is associated with a significant accumulation of necrotic cellular debris, fluid, and peripheral immune cells in the central nervous system (CNS). Additionally, cells, antigens, and other factors exit the brain into the periphery via damaged blood–brain barrier cells, glymphatic transport mechanisms, and lymphatic vessels, which dramatically influence the systemic immune response and lead to complex neuroimmune communication. As a result, the immunological response after stroke is a highly dynamic event that involves communication between multiple organ systems and cell types, with significant consequences on not only the initial stroke tissue injury but long-term recovery in the CNS. In this review, we discuss the complex immunological and physiological interactions that occur after stroke with a focus on how the peripheral immune system and CNS communicate to regulate post-stroke brain homeostasis. First, we discuss the post-stroke immune cascade across different contexts as well as homeostatic regulation within the brain. Then, we focus on the lymphatic vessels surrounding the brain and their ability to coordinate both immune response and fluid homeostasis within the brain after stroke. Finally, we discuss how therapeutic manipulation of peripheral systems may provide new mechanisms to treat stroke injury.

2019 ◽  
Vol 317 (6) ◽  
pp. C1079-C1092 ◽  
Author(s):  
Marquet Minor ◽  
Karel P. Alcedo ◽  
Rachel A. Battaglia ◽  
Natasha T. Snider

Ecto-5′-nucleotidase [cluster of differentiation 73 (CD73)] is a ubiquitously expressed glycosylphosphatidylinositol-anchored glycoprotein that converts extracellular adenosine 5′-monophosphate to adenosine. Anti-CD73 inhibitory antibodies are currently undergoing clinical testing for cancer immunotherapy. However, many protective physiological functions of CD73 need to be taken into account for new targeted therapies. This review examines CD73 functions in multiple organ systems and cell types, with a particular focus on novel findings from the last 5 years. Missense loss-of-function mutations in the CD73-encoding gene NT5E cause the rare disease “arterial calcifications due to deficiency of CD73.” Aside from direct human disease involvement, cellular and animal model studies have revealed key functions of CD73 in tissue homeostasis and pathology across multiple organ systems. In the context of the central nervous system, CD73 is antinociceptive and protects against inflammatory damage, while also contributing to age-dependent decline in cortical plasticity. CD73 preserves barrier function in multiple tissues, a role that is most evident in the respiratory system, where it inhibits endothelial permeability in an adenosine-dependent manner. CD73 has important cardioprotective functions during myocardial infarction and heart failure. Under ischemia-reperfusion injury conditions, rapid and sustained induction of CD73 confers protection in the liver and kidney. In some cases, the mechanism by which CD73 mediates tissue injury is less clear. For example, CD73 has a promoting role in liver fibrosis but is protective in lung fibrosis. Future studies that integrate CD73 regulation and function at the cellular level with physiological responses will improve its utility as a disease target.


Author(s):  
Rajesh Kumar ◽  
Seetha Harilal ◽  
Sabitha M ◽  
Leena K Pappachan ◽  
P R Roshni ◽  
...  

: SARS-CoV-2, the novel coronavirus and the causative organism of Covid-19 pandemic wreaked havoc worldwide producing asymptomatic to symptomatic cases leading to significant morbidity and mortality even after infection. Most of the countries reported a mortality rate of 2-3 % majorly due to cardiorespiratory failures. Recent studies highlighted the neurological involvement playing a key role in cardiorespiratory failures and other symptoms such as headache, anosmia, and ageusia observed in Covid-19 patients. Studies suggests SARS-CoV-2 entry via olfactory epithelium (OE) and the expression of type 2 transmembrane serine protease (TMPRSS2) in addition to angiotensin converting enzyme 2 (ACE2) can facilitate SARS-CoV-2 neurotropism. The virus can either travel via peripheral blood vessel causing endothelial dysfunction, triggering coagulation cascade and multiple organ dysfunction or reach the systemic circulation and take a different route to the blood brain barrier (BBB), disrupting the BBB causing neuroinflammation or neuronal excitotoxicity resulting in the development of encephalitis, encephalopathy, seizures, and strokes. SARS-CoV-2 invasion on brain stem is believed to be responsible for the cardiorespiratory failures observed in Covid-19 patients. Apart from viral invasion via hematogenous route, SARS-CoV-2 neural invasion via PNS nerve terminal, resulting in viral replication and retrograde transportation to soma leading to invasion of the CNS including the brain producing neurological manifestations of the disease either in the initial stages or during the course of the disease and even in a long period post infection in many cases. The ACE2 receptors are expressed in the brain and glial cells and SARS-CoV-2 acts via neuronal as well as non-neuronal pathway. But the exact cell types involved and how they can trigger inflammatory pathways need further in-depth study for the development of targeted therapy.


2021 ◽  
pp. 69-70
Author(s):  
Neelu Khanna Suri ◽  
Kanika Kinra ◽  
Pawan Suri

preeclampsia can affect multiple organ systems due to hypertension and systemic endothelial dysfunction, one of the more delicate maternal systems impacted is the brain It is not always the acute risk of preeclampsia and eclampsia on the brain that impacts maternal outcome. Cortical blindness is generally reversible, and permanent blindness from retinal vascular changes is rare [8].Other than effective treatment of preeclampsia/eclampsia and termination of pregnancy, no specic therapy is indicated in pre- eclamptic women who experience ocular changes. A Similar case with Eclampsia and blindness is presented here.


2020 ◽  
Vol 21 (22) ◽  
pp. 8484 ◽  
Author(s):  
Kritika Sharma ◽  
Tim U. Krohne ◽  
Volker Busskamp

Retinal degenerative diseases lead to irreversible blindness. Decades of research into the cellular and molecular mechanisms of retinal diseases, using either animal models or human cell-derived 2D systems, facilitated the development of several therapeutic interventions. Recently, human stem cell-derived 3D retinal organoids have been developed. These self-organizing 3D organ systems have shown to recapitulate the in vivo human retinogenesis resulting in morphological and functionally similar retinal cell types in vitro. In less than a decade, retinal organoids have assisted in modeling several retinal diseases that were rather difficult to mimic in rodent models. Retinal organoids are also considered as a photoreceptor source for cell transplantation therapies to counteract blindness. Here, we highlight the development and field’s improvements of retinal organoids and discuss their application aspects as human disease models, pharmaceutical testbeds, and cell sources for transplantations.


2020 ◽  
pp. 000486742096147
Author(s):  
Christos Pantelis ◽  
Mahesh Jayaram ◽  
Anthony J Hannan ◽  
Robb Wesselingh ◽  
Jess Nithianantharajah ◽  
...  

Although COVID-19 is predominantly a respiratory disease, it is known to affect multiple organ systems. In this article, we highlight the impact of SARS-CoV-2 (the coronavirus causing COVID-19) on the central nervous system as there is an urgent need to understand the longitudinal impacts of COVID-19 on brain function, behaviour and cognition. Furthermore, we address the possibility of intergenerational impacts of COVID-19 on the brain, potentially via both maternal and paternal routes. Evidence from preclinical models of earlier coronaviruses has shown direct viral infiltration across the blood–brain barrier and indirect secondary effects due to other organ pathology and inflammation. In the most severely ill patients with pneumonia requiring intensive care, there appears to be additional severe inflammatory response and associated thrombophilia with widespread organ damage, including the brain. Maternal viral (and other) infections during pregnancy can affect the offspring, with greater incidence of neurodevelopmental disorders, such as autism, schizophrenia and epilepsy. Available reports suggest possible vertical transmission of SARS-CoV-2, although longitudinal cohort studies of such offspring are needed. The impact of paternal infection on the offspring and intergenerational effects should also be considered. Research targeted at mechanistic insights into all aspects of pathogenesis, including neurological, neuropsychiatric and haematological systems alongside pulmonary pathology, will be critical in informing future therapeutic approaches. With these future challenges in mind, we highlight the importance of national and international collaborative efforts to gather the required clinical and preclinical data to effectively address the possible long-term sequelae of this global pandemic, particularly with respect to the brain and mental health.


2020 ◽  
Vol 319 (1) ◽  
pp. C45-C63
Author(s):  
Jeffrey S. Isenberg ◽  
David D. Roberts

Numerous age-dependent alterations at the molecular, cellular, tissue and organ systems levels underlie the pathophysiology of aging. Herein, the focus is upon the secreted protein thrombospondin-1 (TSP1) as a promoter of aging and age-related diseases. TSP1 has several physiological functions in youth, including promoting neural synapse formation, mediating responses to ischemic and genotoxic stress, minimizing hemorrhage, limiting angiogenesis, and supporting wound healing. These acute functions of TSP1 generally require only transient expression of the protein. However, accumulating basic and clinical data reinforce the view that chronic diseases of aging are associated with accumulation of TSP1 in the extracellular matrix, which is a significant maladaptive contributor to the aging process. Identification of the relevant cell types that chronically produce and respond to TSP1 and the molecular mechanisms that mediate the resulting maladaptive responses could direct the development of therapeutic agents to delay or revert age-associated maladies.


2021 ◽  
Vol 218 (3) ◽  
Author(s):  
Eric Song ◽  
Ce Zhang ◽  
Benjamin Israelow ◽  
Alice Lu-Culligan ◽  
Alba Vieites Prado ◽  
...  

Although COVID-19 is considered to be primarily a respiratory disease, SARS-CoV-2 affects multiple organ systems including the central nervous system (CNS). Yet, there is no consensus on the consequences of CNS infections. Here, we used three independent approaches to probe the capacity of SARS-CoV-2 to infect the brain. First, using human brain organoids, we observed clear evidence of infection with accompanying metabolic changes in infected and neighboring neurons. However, no evidence for type I interferon responses was detected. We demonstrate that neuronal infection can be prevented by blocking ACE2 with antibodies or by administering cerebrospinal fluid from a COVID-19 patient. Second, using mice overexpressing human ACE2, we demonstrate SARS-CoV-2 neuroinvasion in vivo. Finally, in autopsies from patients who died of COVID-19, we detect SARS-CoV-2 in cortical neurons and note pathological features associated with infection with minimal immune cell infiltrates. These results provide evidence for the neuroinvasive capacity of SARS-CoV-2 and an unexpected consequence of direct infection of neurons by SARS-CoV-2.


2021 ◽  
Vol 15 ◽  
Author(s):  
Ulrich Schweizer ◽  
Simon Bohleber ◽  
Wenchao Zhao ◽  
Noelia Fradejas-Villar

Eighteen years ago, unexpected epileptic seizures in Selenop-knockout mice pointed to a potentially novel, possibly underestimated, and previously difficult to study role of selenium (Se) in the mammalian brain. This mouse model was the key to open the field of molecular mechanisms, i.e., to delineate the roles of selenium and individual selenoproteins in the brain, and answer specific questions like: how does Se enter the brain; which processes and which cell types are dependent on selenoproteins; and, what are the individual roles of selenoproteins in the brain? Many of these questions have been answered and much progress is being made to fill remaining gaps. Mouse and human genetics have together boosted the field tremendously, in addition to traditional biochemistry and cell biology. As always, new questions have become apparent or more pressing with solving older questions. We will briefly summarize what we know about selenoproteins in the human brain, glance over to the mouse as a useful model, and then discuss new questions and directions the field might take in the next 18 years.


Author(s):  
Joshua D. Breidenbach ◽  
Prabhatchandra Dube ◽  
Subhanwita Ghosh ◽  
Nikolai N. Modyanov ◽  
Deepak Malhotra ◽  
...  

AbstractViral entry mechanisms for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an important aspect of virulence. Proposed mechanisms involve host cell membrane-bound angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine proteases (TTSPs), such as transmembrane serine protease isoform 2 (TMPRSS2). The distribution of expression of these genes across cell types representing multiple organ systems in healthy individuals has been recently demonstrated. However, comorbidities such as diabetes and cardiovascular disease are highly prevalent in patients with Coronavirus Disease 2019 (COVID-19) and associated with worse outcomes. Whether these conditions contribute directly to SARS-CoV-2 virulence remain unclear. Here we show that the expression levels of ACE2, TMPRSS2 and other viral entry-related genes are modulated in target organs of select disease states. In tissues such as heart, which normally express ACE2 but minimal TMPRSS2, we found that TMPRSS2 as well as other TTSPs are elevated in individuals with comorbidities vs healthy individuals. Additionally, we found increased expression of viral entry-related genes in the settings of hypertension, cancer or smoking across target organ systems. Our results demonstrate that common comorbidities may contribute directly to SARS-CoV-2 virulence and suggest new therapeutic targets to improve outcomes in vulnerable patient populations.


2017 ◽  
Vol 103 (3) ◽  
pp. 269-271 ◽  
Author(s):  
Chayatat Ruangkit ◽  
Sasivimon Soonsawad ◽  
Thavatchai Tutchamnong ◽  
Buranee Swatesutipun

Oxygen is the most common treatment for newborns in need of respiratory support. However, oxygen can cause tissue injury through reactive oxygen species formation, especially in premature infants with reduced antioxidant defences, and may result in short-term and long-term toxic effects in multiple organ systems. Although most hospitals have the capability to tightly control oxygen delivery to hospitalised neonates, in many circumstances, the need is overlooked during infant transport. Lack of awareness of harm or appropriate medical equipment invariably results in excessive oxygen exposure. We developed a quality improvement programme to decrease oxygen exposure to newborns during their transportation, thus improving patient safety and quality of care.


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