COVID-19 lessons from the dish: Dissecting CNS manifestations through brain organoids

Pathogenic Mechanism and Multi-omics Analysis of Oral Manifestations in COVID-19

Coronavirus disease 2019 (COVID-19) is a respiratory infectious disease that seriously threatens human life. The clinical manifestations of severe COVID-19 include acute respiratory distress syndrome and multiple organ failure. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, spreads through contaminated droplets. SARS-CoV-2 particles have been detected in the saliva of COVID-19 patients, implying that the virus can infect and damage the oral cavity. The oral manifestations of COVID-19 include xerostomia and gustatory dysfunction. Numerous studies showed that the four structural proteins of SARS-CoV-2 are its potential pathogenic factors, especially the S protein, which binds to human ACE2 receptors facilitating the entry of the virus into the host cells. Usually, upon entry into the host cell, a pathogen triggers the host’s immune response. However, a mount of multi-omics and immunological analyses revealed that COVID-19 is caused by immune dysregulation. A decrease in the number and phenotypes of immune cells, IFN-1 production and excessive release of certain cytokines have also been reported. In conclusion, this review summarizes the oral manifestations of COVID-19 and multi-omics analysis of SARS-CoV-2 infection.

The Ferret as a Model System for Neocortex Development and Evolution

The neocortex is the largest part of the cerebral cortex and a key structure involved in human behavior and cognition. Comparison of neocortex development across mammals reveals that the proliferative capacity of neural stem and progenitor cells and the length of the neurogenic period are essential for regulating neocortex size and complexity, which in turn are thought to be instrumental for the increased cognitive abilities in humans. The domesticated ferret, Mustela putorius furo, is an important animal model in neurodevelopment for its complex postnatal cortical folding, its long period of forebrain development and its accessibility to genetic manipulation in vivo. Here, we discuss the molecular, cellular, and histological features that make this small gyrencephalic carnivore a suitable animal model to study the physiological and pathological mechanisms for the development of an expanded neocortex. We particularly focus on the mechanisms of neural stem cell proliferation, neuronal differentiation, cortical folding, visual system development, and neurodevelopmental pathologies. We further discuss the technological advances that have enabled the genetic manipulation of the ferret in vivo. Finally, we compare the features of neocortex development in the ferret with those of other model organisms.

[COVID-19 and the central and peripheral nervous system]

Die gesundheitlichen Auswirkungen der Coronavirus-Krankheit 2019 (COVID-19) durch die Infektion von SARS-CoV‑2 (Schweres-Akutes-Respiratorisches–Syndrom-Coronavirus 2) werden mit der Ausbreitung der Pandemie immer deutlicher. Neben der Lunge sind auch andere Organe betroffen, welche die Morbidität und Mortalität deutlich beeinflussen können. Insbesondere neurologische Symptome unter Beteiligung des zentralen und peripheren Nervensystems können akute Symptome oder Langzeitfolgen auslösen. Die Mechanismen dieser Neuropathogenese der SARS-CoV-2-Infektion und ihr Zusammenhang mit akuten und chronischen neurologischen Symptomen sind Gegenstand aktueller Studien, die sich mit der Untersuchung einer potenziellen direkten und indirekten Virusinfektion des Nervensystems beschäftigen. In der folgenden Übersichtsarbeit wird der aktuelle Stand über die neuropathologischen Manifestationen, die molekulare Pathogenese, die möglichen Infektionswege im Nervensystem und die systemischen Wirkungen zusammengefasst. Zusätzlich wird ein Überblick über das bundesweite Register CNS-COVID19 und Kooperationen gegeben, die zu einem besseren Verständnis der neurologischen Symptome von COVID-19 beitragen sollen.