The fluorescence ubiquitination-based cell cycle indicator (FUCCI) is a powerful tool for use in live cells but current FUCCI-based assays have limited throughput in terms of image processing and quantification. Here, we developed a lentiviral system that rapidly introduced FUCCI transgenes into cells by using an all-in-one expression cassette, FastFUCCI. The approach alleviated the need for sequential transduction and characterisation, improving labelling efficiency. We coupled the system to an automated imaging workflow capable of handling large datasets. The integrated assay enabled analyses of single-cell readouts at high spatiotemporal resolution. With the assay, we captured in detail the cell cycle alterations induced by antimitotic agents. We found that treated cells accumulated at G2 or M phase but eventually advanced through mitosis into the next interphase, where the majority of cell death occurred, irrespective of the preceding mitotic phenotype. Some cells appeared viable after mitotic slippage, and a fraction of them subsequently re-entered S phase. Accordingly, we found evidence that targeting the DNA replication origin activity sensitised cells to paclitaxel. In summary, we demonstrate the utility of the FastFUCCI assay for quantifying spatiotemporal dynamics and identify its potential in preclinical drug development.

Objectives:

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Introduction No studies have reported mental health symptom comparisons prior to and during COVID-19 in vulnerable medical populations. Objective To compare anxiety and depression symptoms among people with a pre-existing medical condition and factors associated with changes. Methods Pre-COVID-19 Scleroderma Patient-centered Intervention Network Cohort data were linked to COVID-19 data from April 2020. Multiple linear and logistic regression were used to assess factors associated with continuous change and ≥ 1 minimal clinically important difference (MCID) change for anxiety (PROMIS Anxiety 4a v1.0; MCID = 4.0) and depression (Patient Health Questionnaire-8; MCID = 3.0) symptoms, controlling for pre-COVID-19 levels. Results Mean anxiety symptoms increased 4.9 points (95% confidence interval [CI] 4.0 to 5.7). Depression symptom change was negligible (0.3 points; 95% CI -0.7 to 0.2). Compared to France ( N = 159), adjusted anxiety symptom change scores were significantly higher in the United Kingdom ( N = 50; 3.3 points, 95% CI 0.9 to 5.6), United States ( N = 128; 2.5 points, 95% CI 0.7 to 4.2), and Canada ( N = 98; 1.9 points, 95% CI 0.1 to 3.8). Odds of ≥1 MCID increase were 2.6 for the United Kingdom (95% CI 1.2 to 5.7) but not significant for the United States (1.6, 95% CI 0.9 to 2.9) or Canada (1.4, 95% CI 0.7 to 2.5). Older age and adequate financial resources were associated with less continuous anxiety increase. Employment and shorter time since diagnosis were associated with lower odds of a ≥ 1 MCID increase. Conclusions Anxiety symptoms, but not depression symptoms, increased dramatically during COVID-19 among people with a pre-existing medical condition.