The Transcriptome Landscape of the In Vitro Human Airway Epithelium Response to SARS-CoV-2.

Airway-liquid interface cultures of primary epithelial cells and of induced pluripotent stem-cell-derived airway epithelial cells (ALI and iALI, respectively) are physiologically relevant models for respiratory virus infection studies because they can mimic the in vivo human bronchial epithelium. Here, we investigated gene expression profiles in human airway cultures (ALI and iALI models), infected or not with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), using our own and publicly available bulk and single-cell transcriptome datasets. SARS-CoV-2 infection significantly increased the expression of interferon-stimulated genes (IFI44, IFIT1, IFIT3, IFI35, IRF9, MX1, OAS1, OAS3 and ISG15) and inflammatory genes (NFKBIA, CSF1, FOSL1, IL32 and CXCL10) by day 4 post-infection, indicating activation of the interferon and immune responses to the virus. Extracellular matrix genes (ITGB6, ITGB1 and GJA1) were also altered in infected cells. Single-cell RNA sequencing data revealed that SARS-CoV-2 infection damaged the respiratory epithelium, particularly mature ciliated cells. The expression of genes encoding intercellular communication and adhesion proteins was also deregulated, suggesting a mechanism to promote shedding of infected epithelial cells. These data demonstrate that ALI/iALI models help to explain the airway epithelium response to SARS-CoV-2 infection and are a key tool for developing COVID-19 treatments.

Blood amyloid and tau biomarkers as predictors of cerebrospinal fluid profiles.

INTRODUCTION: Blood biomarkers represent a major advance for improving the management, diagnosis, and monitoring of Alzheimer's disease (AD). However, their context of use in relation to routine cerebrospinal fluid (CSF) analysis for the quantification of amyloid peptides and tau proteins remains to be determined. METHODS: We studied in two independent cohorts, the performance of blood biomarkers in detecting "nonpathological" (A-/T-/N-), amyloid (A+) or neurodegenerative (T+ /N+) CSF profiles. RESULTS: Plasma Aß1-42/Aß1-40 ratio and phosphorylated tau (p-tau(181)) were independent and complementary predictors of the different CSF profile and in particular of the nonpathological (A-/T-/N-) profile with a sensitivity and specificity close to 85%. These performances and the corresponding biomarker thresholds were significantly different from those related to AD detection. CONCLUSION: The use of blood biomarkers to identify patients who may benefit from secondary CSF testing represents an attractive stratification strategy in the clinical management of patients visiting memory clinics. This could reduce the need for lumbar puncture and foreshadow the use of blood testing on larger populations.

Ultrasensitive digital immunoassays for SOD1 conformation in amyotrophic lateral sclerosis.

Aim: The aim of this study was to detect misfolded Cu/Zn SOD1 as a potential biomarker for amyotrophic lateral sclerosis (ALS). Materials & methods: Two ultrasensitive immunodetection assays were developed for the quantification of total and misfolded SOD1. Results: The detection of total and misfolded SOD1 was possible in human serum and cerebrospinal fluid. Total SOD1 was increased in cerebrospinal fluid from ALS patients. Misfolded SOD1 had low and variable expression in both control and ALS patient samples. Conclusion: These assays hold promise for improving our understanding of ALS and its detection, and could lead to more effective treatment options in the future. Further studies in larger cohorts are now required.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with protein misfolding, including Cu/Zn SOD1. In this study, we set up a method for detecting normal and pathological misfolded SOD1 in human serum and cerebrospinal fluid. SOD1 was increased in ALS and misfolded SOD1 had low and variable expression in both control and ALS. These assays holds promise for improving our understanding of ALS and its diagnosis.