Assessment of SARS-CoV-2 infection in astrocytes

Discovered in late 2019 in a market in the city of Wuhan, Hubei Province, China, SARS-CoV-2 is an important member of the Coronaviridae family, responsible for bringing the whole world into a state of alert causing a global pandemic. The virus has been identified as causing a characteristic clinical condition known as "Corona-virus disease 2019" (COVID-19), causing an Acute Respiratory Syndrome. Being a respiratory virus, transmitted by direct contact with an infected person and by touching contaminated surfaces, SARS-CoV-2 quickly spread throughout the world, causing a pandemic, having today more than 535 million people infected and causing more than million deaths. In addition to the respiratory system, the virus is present in other cells in the body. Findings show the presence of SARS-CoV-2 in cerebrospinal fluid associated with changes in the expression of neuronal inflammation markers, as well as an increased expression of cytokines released by astrocytes, indicating an alteration in the Central Nervous System (CNS). In this project, we analyzed the effects of SARS-CoV-2 infection directly on astrocytes, glial cells that are extremely important for the maintenance of homeostasis and CNS defense. Therefore, we produced astrocytes from three human iPSC strains to verify aspects of cell morphology and physiology, as well as gene and protein expression, after infection with the virus. We found that SARS-CoV-2 is capable of infecting astrocytes, but some studies are still needed to better elucidate its role in the interaction with this cell type in the CNS.

[An electron microscopic study of neocortex of Syrian hamsters (Mesocricetus auratus) infected with SARS-CoV-2 (Coronaviridae: Coronavirinae: Betacoronavirus: Sarbecovirus)].

INTRODUCTION: Convalescent COVID-19 patients have various signs of central nervous system damage, including those directly associated with SARS-CoV-2. Hence, studies of SARS-COV-2 related morphological changes in neocortex are particularly relevant for understanding the mechanisms of their formation and development of approaches to preclinical evaluation of the effectiveness of antiviral drugs. The purpose of the research is a longitudinal study of the ultrastructural alterations in Syrian hamsters neocortex after experimental SARS-CoV-2 infection. MATERIALS AND METHODS: Male Syrian hamsters weighing 80100 g, aged 4 to 6 weeks, were infected with 26 l SARS-CoV-2 intranasally with 4104 TCD50/ml of viral particles. The animals were euthanized on days 3, 7 or 28 post-infection, the brain was extracted with the cortex excision. The material analysis was performed using transmission electron microscopy. RESULTS AND DISCUSSION: On day 3 post-infection, the number of moderately hyperchromic neurons in neocortex increased, while by the day 7 the number of apoptotic cells significantly increased. Simultaneously, an increased signs of neuronophagy and representation of atypical glia were observed. Increased number of altered oligodendrocytes was observed on day 28 post-infection. Viral invasion was accompanied by changes in neocortical cells since day 3 post-infection, such as transformation of their nucleus, the rough endoplasmic reticulum and the Golgi vesicles as well as microvascular spasm with perivascular edema. CONCLUSION: As a result of electron microscopic study, the ultrastructural alterations in neocortex were described in an experimental model of SARS-CoV-2 infection. The findings can be used to identify the mechanisms of infection pathogenesis and to search for the new directions in development of medicines.

Is amyloid involved in acute neuroinflammation? A CSF analysis in encephalitis.

INTRODUCTION: Several investigations have argued for a strong relationship between neuroinflammation and amyloid metabolism but it is still unclear whether inflammation exerts a pro-amyloidogenic effect, amplifies the neurotoxic effect of amyloid, or is protective. METHODS: Forty-two patients with acute encephalitis (ENC) and 18 controls underwent an extended cerebrospinal fluid (CSF) panel of inflammatory, amyloid (Aß40, 42, and 38, sAPP-α, sAPP-ß), glial, and neuronal biomarkers. Linear and non-linear correlations between CSF biomarkers were evaluated studying conditional independence relationships. RESULTS: CSF levels of inflammatory cytokines and neuronal/glial markers were higher in ENC compared to controls, whereas the levels of amyloid-related markers did not differ. Inflammatory markers were not associated with amyloid markers but exhibited a correlation with glial and neuronal markers in conditional independence analysis. DISCUSSION: By an extensive CSF biomarkers analysis, this study showed that an acute neuroinflammation state, which is associated with glial activation and neuronal damage, does not influence amyloid homeostasis.

Neuroinflammation in Dementia-Therapeutic Directions in a COVID-19 Pandemic Setting.

Although dementia is a heterogenous group of diseases, inflammation has been shown to play a central role in all of them and provides a common link in their pathology. This review aims to highlight the importance of immune response in the most common types of dementia. We describe molecular aspects of pro-inflammatory signaling and sources of inflammatory activation in the human organism, including a novel infectious agent, SARS-CoV-2. The role of glial cells in neuroinflammation, as well as potential therapeutic approaches, are then discussed. Peripheral immune response and increased cytokine production, including an early surge in TNF and IL-1ß concentrations activate glia, leading to aggravation of neuroinflammation and dysfunction of neurons during COVID-19. Lifestyle factors, such as diet, have a large impact on future cognitive outcomes and should be included as a crucial intervention in dementia prevention. While the use of NSAIDs is not recommended due to inconclusive results on their efficacy and risk of side effects, the studies focused on the use of TNF antagonists as the more specific target in neuroinflammation are still very limited. It is still unknown, to what degree neuroinflammation resulting from COVID-19 may affect neurodegenerative process and cognitive functioning in the long term with ongoing reports of chronic post-COVID complications.

Impact of SARS-CoV-2 infection during pregnancy on postnatal brain development: The potential role of glial cells

Glial cells are crucial for maintaining central nervous system (CNS) homeostasis. They actively participate in immune responses, as well as form functional barriers, such as blood-brain barrier (BBB), which restrict the entry of pathogens and inflammatory mediators into the CNS. In general, viral infections during the gestational period can alter the embryonic and fetal environment, and the related inflammatory response may affect neurodevelopment and lead to behavioral dysfunction during later stage of life, as highlighted by our group for Zika virus infection. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) induces a cytokine storm and, during pregnancy, may be related to a more severe form of the coronavirus disease-19 (COVID-19) and also to higher preterm birth rates. SARS-CoV-2 can also affect the CNS by inducing neurochemical remodeling in neural cells, which can compromise neuronal plasticity and synaptic function. However, the impact of SARS-CoV-2 infection during pregnancy on postnatal CNS, including brain development during childhood and adulthood, remains undetermined. Our group has recently highlighted the impact of COVID-19 on the expression of molecular markers associated with neuropsychiatric disorders, which are strongly related to the inflammatory response. Thus, based on these relationships, we discussed the impact of SARS-CoV-2 infection either during pregnancy or in critical periods of neurodevelopment as a risk factor for neurological consequences in the offspring later in life, focusing on the potential role of glial cells. Thus, it is important to consider future and long-term public health concerns associated with SARS-CoV-2 infection during pregnancy. [ FROM AUTHOR] Copyright of Biocell is the property of Tech Science Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Inhibition of Monoacylglycerol Lipase by NSD1819 as an Effective Strategy for the Endocannabinoid System Modulation against Neuroinflammation-Related Disorders.

Neuroinflammation is a key pathological event shared by different diseases affecting the nervous system. Since the underlying mechanism of neuroinflammation is a complex and multifaceted process, current pharmacological treatments are unsatisfactory-a reason why new therapeutic approaches are mandatory. In this context, the endocannabinoid system has proven to possess neuroprotective and immunomodulatory actions under neuroinflammatory status, and its modulation could represent a valuable approach to address different inflammatory processes. To this aim, we evaluated the efficacy of a repeated treatment with NSD1819, a potent ß-lactam-based monoacylglycerol lipase inhibitor in a mouse model of neuroinflammation induced by lipopolysaccharide (LPS) injection. Mice were intraperitoneally injected with LPS 1 mg/kg for five consecutive days to induce systemic inflammation. Concurrently, NSD1819 (3 mg/kg) was daily per os administered from day 1 until the end of the experiment (day 11). Starting from day 8, behavioral measurements were performed to evaluate the effect of the treatment on cognitive impairments, allodynia, motor alterations, anhedonia, and depressive-like behaviors evoked by LPS. Histologically, glial analysis of the spinal cord was also performed. The administration of NSD1819 was able to completely counteract thermal and mechanical allodynia as highlighted by the Cold plate and von Frey tests, respectively, and to reduce motor impairments as demonstrated by the Rota rod test. Moreover, the compound was capable of neutralizing the memory loss in the Passive avoidance test, and reducing depressive-like behavior in the Porsolt test. Finally, LPS stimulation caused a significant glial cells activation in the dorsal horn of the lumbar spinal cord that was significantly recovered by NSD1819 repeated treatment. In conclusion, NSD1819 was able to thwart the plethora of symptoms evoked by LPS, thus representing a promising candidate for future applications in the context of neuroinflammation and related diseases.

COVID-19 causes neuronal degeneration and reduces neurogenesis in human hippocampus.

Recent investigations of COVID-19 have largely focused on the effects of this novel virus on the vital organs in order to efficiently assist individuals who have recovered from the disease. In the present study we used hippocampal tissue samples extracted from people who died after COVID-19. Utilizing histological techniques to analyze glial and neuronal cells we illuminated a massive degeneration of neuronal cells and changes in glial cells morphology in hippocampal samples. The results showed that in hippocampus of the studied brains there were morphological changes in pyramidal cells, an increase in apoptosis, a drop in neurogenesis, and change in spatial distribution of neurons in the pyramidal and granular layer. It was also demonstrated that COVID-19 alter the morphological characteristics and distribution of astrocyte and microglia cells. While the exact mechanism(s) by which the virus causes neuronal loss and morphology in the central nervous system (CNS) remains to be determined, it is necessary to monitor the effect of SARS-CoV-2 infection on CNS compartments like the hippocampus in future investigations. As a result of what happened in the hippocampus secondary to COVID-19, memory impairment may be a long-term neurological complication which can be a predisposing factor for neurodegenerative disorders through neuroinflammation and oxidative stress mechanisms.

64th Annual Meeting of the Pathology Section of the German Veterinary Medical Association

These proceedings contain 25 papers from the 64th Annual Meeting of the Pathology Section of the German Veterinary Medical Association. Topics include tumour infiltrating lymphocytes in mammary carcinomas in domestic rabbits;what decides good or bad? - global gene expression analysis of the adenoma of the hepatoid perianal glands and adenocarcinoma the canine apocrine anal sac glands;the canine cutaneous histiocytoma - boring or perspective in immuno-oncology?;impact of antibiotic pretreatment on ventilator-induced lung injury: contradiction between histology and transcriptome analysis?;characterization of murine satellite glial cells of the dorsal root ganglia - a unique cell population with potential regenerative capacities;impact of antibiotic pretreatment on ventilator-induced lung injury: contradiction between histology and transcriptome analysis?;primary diffuse leptomeningeals oligodendrogliomatosis in a cat;pathomorphological studies of fibroadnexal dysplasia in dogs;pyogranulomatous inflammation in multiple Organs of a dog with evidence of Corynebacterium tuberculostearicum;ovary tumors in cats - overview of the examination material from 2009-2020 and case report of a recurrent dysgerminoma;atherosclerosis in the dog;spinal neuroenteric cyst in one Saint Bernard;MENX - an endogenous model for pseudohypoxic pheochromocytomas;molecular Level Evolution II: similarities of CLCA2 in sauropsids and mammals;in vivo detection of double-stranded Ribonucleic acid (RNA) as an early detection marker unclear viral infections using the example of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) in experimental infected hamsters;the role of different mast cell subtypes in the context of intestinal carcinogenesis - a species-comparative approach;an underestimated treasure in paraffin - establishment of a global transcriptome analysis canine tumors from FFPE material based on QuantSeq 3' technology;well researched? - an approximation of the role of CLCA1 in joints through usage molecular databases;integration of digitized historical and cytopathology into an open source DICOM database and viewer system;3R 3D: skin model for the study of viral infections;CARD9 signaling promotes hippocampal neurogenesis and cytokine balance in a mouse model of virus-induced encephalitis;neuropathological changes after intranasal infection with Rift Valley fever virus - a murine model for human encephalitis;a T-cell a day keeps Theiler away - the influence non-reactive T-cells on the course of a Theiler virus infection in mice with C57BL/6 background;digitization in pathology - new opportunities and their obstacles;and specific features of satellite glial cells of dog and pig.

Sex-Specific Microglial Activation and SARS-CoV-2 Receptor Expression Induced by Chronic Unpredictable Stress.

The coronavirus disease 2019 (COVID-19) pandemic has generated a lot of stress and anxiety among not only infected patients but also the general population across the globe, which disturbs cerebral immune homeostasis and potentially exacerbates the SARS-CoV-2 virus-induced neuroinflammation, especially among people susceptible to neuropsychiatric disorders. Here, we used a chronic unpredictable mild stress (CUMS) mouse model to study its effects on glia-mediated neuroinflammation and expression of SARS-CoV2 viral receptors. We observed that female mice showed depressive-like behavior after CUMS, whereas male mice showed enhanced anxiety and social withdrawal. Interestingly, CUMS led to increased amounts of total and MHCII+ microglia in the hippocampi of female mice but not male mice. mRNA levels of SARS-CoV-2 viral receptors angiotensin-converting enzyme 2 (Ace2) and basigin (Bsg) were also upregulated in the prefrontal cortices of stressed female mice but not male mice. Similarly, sex-specific changes in SARS-CoV-2 viral receptors FURIN and neuropilin-1 (NRP1) were also observed in monocytes of human caregivers enduring chronic stress. Our findings provided evidence on detrimental effects of chronic stress on the brain and behavior and implied potential sex-dependent susceptibility to SARS-CoV-2 infection after chronic stress.

SARS-CoV-2 targets glial cells in human cortical organoids.

Coronavirus disease 2019 (COVID-19) patients have manifested a variety of neurological complications, and there is still much to reveal regarding the neurotropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human stem cell-derived brain organoids offer a valuable in vitro approach to study the cellular effects of SARS-CoV-2 on the brain. Here we used human embryonic stem cell-derived cortical organoids to investigate whether SARS-CoV-2 could infect brain tissue in vitro and found that cortical organoids could be infected at low viral titers and within 6 h. Importantly, we show that glial cells and cells of the choroid plexus were preferentially targeted in our model, but not neurons. Interestingly, we also found expression of angiotensin-converting enzyme 2 in SARS-CoV-2 infected cells; however, viral replication and cell death involving DNA fragmentation does not occur. We believe that our model is a tractable platform to study the cellular effects of SARS-CoV-2 infection in brain tissue.

Does COVID-19 contribute to development of neurological disease?

BACKGROUND: Although coronavirus disease 2019 (COVID-19) has been associated primarily with pneumonia, recent data show that the causative agent of COVID-19, the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can infect a large number of vital organs beyond the lungs, such as the heart, kidneys, and the brain. Thus, there is evidence showing possible retrograde transmission of the virus from the olfactory epithelium to regions of the brain stem. METHODS: This is a literature review article. The research design method is an evidence-based rapid review. The present discourse aim is first to scrutinize and assess the available literature on COVID-19 repercussion on the central nervous system (CNS). Standard literature and database searches were implemented, gathered relevant material, and extracted information was then assessed. RESULTS: The angiotensin-converting enzyme 2 (ACE2) receptors being the receptor for the virus, the threat to the central nervous system is expected. Neurons and glial cells express ACE2 receptors in the CNS, and recent studies suggest that activated glial cells contribute to neuroinflammation and the devastating effects of SARS-CoV-2 infection on the CNS. The SARS-CoV-2-induced immune-mediated demyelinating disease, cerebrovascular damage, neurodegeneration, and depression are some of the neurological complications discussed here. CONCLUSION: This review correlates present clinical manifestations of COVID-19 patients with possible neurological consequences in the future, thus preparing healthcare providers for possible future consequences of COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and glial cells: Insights and perspectives.

In December 2019, a pneumonia outbreak was reported in Wuhan, Hubei province, China. Since then, the World Health Organization declared a public health emergency of international concern due to a growing number of deaths around the globe, as well as unparalleled economic and sociodemographic consequences. The disease called coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel form of human coronavirus. Although coronavirus infections have been associated with neurological manifestations such as febrile seizures, convulsions, change in mental status, and encephalitis, less is known about the impact of SARS-CoV-2 in the brain. Recently, emerging evidence suggests that SARS-CoV-2 is associated with neurological alterations in COVID-19 patients with severe clinical manifestations. The molecular and cellular mechanisms involved in this process, as well as the neurotropic and neuroinvasive properties of SARS-CoV-2, are still poorly understood. Glial cells, such as astrocytes and microglia, play pivotal roles in the brain response to neuroinflammatory insults and neurodegenerative diseases. Further, accumulating evidence has shown that those cells are targets of several neurotropic viruses that severely impact their function. Glial cell dysfunctions have been associated with several neuroinflammatory diseases, suggesting that SARS-CoV-2 likely has a primary effect on these cells in addition to a secondary effect from neuronal damage. Here, we provide an overview of these data and discuss the possible implications of glial cells as targets of SARS-CoV-2. Considering the roles of microglia and astrocytes in brain inflammatory responses, we shed light on glial cells as possible drivers and potential targets of therapeutic strategies against neurological manifestations in patients with COVID-19. The main goal of this review is to highlight the need to consider glial involvement in the progression of COVID-19 and potentially include astrocytes and microglia as mediators of SARS-CoV-2-induced neurological damage.