Organoid technology and lung injury mouse models evaluating effects of hydroxychloroquine on lung epithelial regeneration

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) damages lung epithelial stem/progenitor cells. Ideal anti-SARS-CoV-2 drug candidates should be screened to prevent secondary injury to the lungs. Here, we propose that in vitro threedimensional organoid and lung injury repair mouse models are powerful models for the screening antiviral drugs. Lung epithelial progenitor cells, including airway club cells and alveolar type 2 (AT2) cells, were co-cultured with supportive fibroblast cells in transwell inserts. The organoid model was used to evaluate the possible effects of hydroxychloroquine, which is administered as a symptomatic therapy to COVID-19 patients, on the function of mouse lung stem/progenitor cells. Hydroxychloroquine was observed to promote the self-renewal of club cells and differentiation of ciliated and goblet cells in vitro. Additionally, it inhibited the self-renewal ability of AT2 cells in vitro.Naphthalene-or bleomycin-induced lung injury repair mouse models were used to investigate the in vivo effects of hydroxychloroquine on the regeneration of club and AT2 cells, respectively. The naphthalene model indicated that the proliferative ability and differentiation potential of club cells were unaffected in the presence of hydroxychloroquine. The bleomycin model suggested that hydroxychloroquine had a limited effect on the proliferation and differentiation abilities of AT2 cells. These findings suggest that hydroxychloroquine has limited effects on the regenerative ability of epithelial stem/progenitor cells. Thus, stem/progenitor cell-derived organoid technology and lung epithelial injury repair mouse models provide a powerful platform for drug screening, which could possibly help end the pandemic.

Evaluation of Broad Anti-Coronavirus Activity of Autophagy-Related Compounds Using Human Airway Organoids

“…In the future, it is expected that the efficacy and toxicity of candidate compounds can be evaluated more accurately by conducting tests using not only airway organoids but also alveolar organoids 27 and animal experiments. 28 …”

“…Although the results of compound screening may differ depending on the SARS-CoV-2 variant, drug concentration, and cell type used in a study, it is believed that using a physiologically relevant model will lead us to results with improved clinical predictability. In the future, it is expected that the efficacy and toxicity of candidate compounds can be evaluated more accurately by conducting tests using not only airway organoids but also alveolar organoids and animal experiments …”

“…In the future, it is expected that the efficacy and toxicity of candidate compounds can be evaluated more accurately by conducting tests using not only airway organoids but also alveolar organoids 27 and animal experiments. 28 Cycloheximide has been reported to inhibit autophagy via mTORC1 activation. 29 Autophagy inhibition is a potential mechanism for the observed inhibition of SARS-CoV-2 infection by cycloheximide.…”

Towards a “Testis in a Dish”: Generation of Mouse Testicular Organoids that Recapitulate Testis Structure and Expression Profiles

“…As culturing in various 2D culture conditions did not seem optimal in terms of cell morphology, we sought a 3D culture system that would better support testicular organoid formation and maintenance. Several organoid systems, including kidney, lung, liver, and cerebral organoids, use transwell inserts [32][33][34][35][36][37]. Since the kidney and gonads share common developmental origin from the intermediate mesoderm [38], and they both possess tubular structures, we explored the use of transwell inserts for generating testicular organoids (Figure 1A).…”