Post-COVID anosmia and the expression of pathological proteins in nasal mucosa nerves endings

Introduction: Anosmia and ageusia were observed as frequent neurological complications of SARS-CoV-2 infections. the aim of the study was to elaborate methods for detection of pathological proteins in nerve endings and to evaluate the frequency and intensity of pathological proteins expression in patients with persistent anosmia. Material(s) and Method(s): the study included 249 patients (181 females and 68 males) aged 47 +/-14 years from NeuroCOViD Polyclinic in Poznan observed from April 2021 untill now. the mucosal biopsy was performed using endoscopy from anterior ethmoid cells. the expression of alpha-synuclein was evaluated using immunofuorescence, and amyloid, tau and tDP43 proteins-using immunohistochemistry. Result(s): Anosmia was observed in 42% of patients and cacosmia-in 6%. Ageusia/dysgeusia was observed in 31% cases. in patients with mild clinical course of COViD19-not hospitalized anosmia (45%) and dys-geusia were more frequent (33%), and cacosmia was observed only in this group. in hospitalized patients anosmia was found in 22% of cases, dysgeusia in 13%, and cacosmia was not observed at all. the expression of alpha-synuclein, amyloid, tau and tDP43 proteins was found in nerve bundles, epithelial cells and in surrounding (nerve endings) of gland cells. Conclusion(s): SARS-CoV-2 infection may induce the expression of pathological proteins in olfactory mucosa of post-COViD patients with anosmia.

Corrigendum: TDP-43 and NEAT long non-coding RNA: Roles in neurodegenerative disease.

[This corrects the article DOI: 10.3389/fncel.2022.954912.].

DIFFERENTIAL TRANSCRIPTOMIC CHANGES IN THE CENTRAL NERVOUS SYSTEM AND NEUROGENIC BLADDERS OF MICE INFECTED WITH A CORONAVIRUS

INTRODUCTION AND OBJECTIVE: Neurodegenerative diseases, such as multiple sclerosis (MS), often lead to the development of neurogenic lower urinary tract symptoms (LUTS). We previously characterized neurogenic bladder dysfunction in a mouse model of MS induced by a coronavirus, mouse hepatitis virus (MHV). The objective of this study was to identify genes and pathways linking neuroinflammation in the central nervous system with urinary bladder dysfunction to enhance our understanding of the mechanisms underlying LUTS in demyelinating diseases. METHODS: Adult C57BL/6 male mice (N=12) received either an intracranial injection of MHV (6,000 PFU) or sterile saline (control). The lumbosacral (L6-S2) spinal cord (SC) segments and urinary bladders were collected during acute infection stage (week 1) and at the first peak of demyelination (week 4) after inoculation with the virus. Total RNA was isolated and analyzed using Nanostring nCounter Neuroinflammation panel. The expression levels of 770 genes associated with neuroinflammation were assessed and compared between the specimens. RESULTS: Transcriptome analysis of SC specimens confirmed a significantly increased expression of 132 genes in MHV mice (tens to hundreds fold change) involved in the regulation of astrocyte, microglia and oligodendrocyte functions, neuroinflammation and immune responses. Out of 132 genes up-regulated in the SC, only 2 genes (siglec1, 46-fold in the SC, 2.6-fold at 1 week and 1.8-fold at 4 weeks in the bladder;and zbp1, 568-fold in the SC, 2.8-fold at 1 week and 2.2-fold at 4 weeks in the bladder) were up-regulated in the urinary bladders of MHV-infected mice. Additionally, two genes were significantly up-regulated (ttr, 2.2-fold at 1week and 1.7-fold at 4 weeks;and ms4a4a, 2.3-fold at 1week and 1.6-fold at 4 weeks), and two were down-regulated (asb2, -1.8-fold at 1 week and -1.6-fold at 4 weeks, and myct1, -1.7-fold at 1week and -1.6-fold at 4 weeks) exclusively in the urinary bladders of MHV mice. CONCLUSIONS: Two genes, siglec1 (encodes type 1 transmembrane protein, expressed in microglia and macrophages, promotes neuroinflammation) and zbp1 (encodes a Z-DNA binding protein, plays role in the innate immune response) link the development of neuroinflammation in the central nervous system with neurogenic changes in the urinary bladders of MHV-infected mice. Further research is needed to establish a functional relationship between expression of these genes and neurogenic LUTS.

Longitudinal changes of neurospecific serum proteins in COVID-19 patients

INTRODUCTION/HYPOTHESIS: COVID-19 has been associated with distinct types of neuronal damage. We hypothesize that the progression of neurological damage will be related to an imbalance between neurodegeneration, neuroinflammatory, and neuroprotective markers, therefore suggesting a potential mechanism for the emergence of adverse, chronic outcomes. METHODS: 105 patients admitted to an urban, academic hospital with a diagnosis of COVID-19 were enrolled. Serum neuroprotective (clusterin, fetuin), neurodegenerative (τ, phosphorylated τ, amyloids, TDP43, NRGN, NCAM-1, and KLK6), and neuroinflammatory (CCL23, YKL40, MIF) markers were collected. These were analyzed longitudinally in conjunction with immune system activators (RAGE, IL-34) using the multiplex platform. Electronic medical records were used to collect demographic and clinical data. RESULTS: Of the 105 patients, 5 were diagnosed with stroke within 28 days of admission, followed by an additional 6 strokes occurring by 6 months, or a 9.5% occurrence of stroke overall. Serum levels of Amyloid β42 declined significantly for the general population 7 days after admission when compared to initial collections (p< 0.001), while Amyloid β40, KLK6, and MIF declined and recovered within the same 7 days (p< 0.001, p< 0.001, p=0.003). The neuroprotective markers fetuin and clusterin were particularly dynamic with fetuin decreasing and restoring in less than 7 days (p=0.02) and clusterin remaining low after admission (p< 0.001). Most patients had persistently elevated CCL23 levels, with the stroke patient cohort having the highest values (p=0.018). The IL-6 levels of stroke patients were significantly higher compared to their non-stroke counterparts one week after admission (p=0.001), while IL-8 levels fluctuated before declining (p< 0.001). CONCLUSIONS: Our data reveals elevations in neuronal damage in the 7 days following hospital admission for COVID-19 patients. The down-regulation of fetuin and clusterin is particularly compelling as their declines may be linked to the elevated neuronal injury seen with increased neuroinflammatory markers, specifically CCL23 and IL-6. Serum levels of neurodegeneration markers proved complex, therefore possibly suggesting a more dynamic relationship to the neural abnormalities seen in COVID-19 patients.

Optimization of reaction condition of recombinase polymerase amplification to detect SARS-CoV-2 DNA and RNA using a statistical method.

Recombinase polymerase amplification (RPA) is an isothermal reaction that amplifies a target DNA sequence with a recombinase, a single-stranded DNA-binding protein (SSB), and a strand-displacing DNA polymerase. In this study, we optimized the reaction conditions of RPA to detect SARS-CoV-2 DNA and RNA using a statistical method to enhance the sensitivity. In vitro synthesized SARS-CoV-2 DNA and RNA were used as targets. After evaluating the concentration of each component, the uvsY, gp32, and ATP concentrations appeared to be rate-determining factors. In particular, the balance between the binding and dissociation of uvsX and DNA primer was precisely adjusted. Under the optimized condition, 60 copies of the target DNA were specifically detected. Detection of 60 copies of RNA was also achieved. Our results prove the fabrication flexibility of RPA reagents, leading to an expansion of the use of RPA in various fields.