Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with no cure except transplantation. Abnormal alveolar epithelial regeneration is a key driver of IPF development. The function of YAP in alveolar regeneration and IPF pathogenesis remains elusive. Here, we firstly revealed activation of YAP in AEC2s from human IPF lungs and fibrotic mouse lungs. Notably, conditional deletion of YAP in mouse AEC2s exacerbated bleomycin-induced pulmonary fibrosis. Intriguingly, we showed in both conditional knockout mice and alveolar organoids that YAP deficiency impaired AEC2 proliferation and differentiation into AEC1s. Mechanistically, YAP regulated expression levels of genes associated with cell cycle progression and AEC1 differentiation. Furthermore, overexpression of YAP in vitro promoted cell proliferation. These results indicate the critical role of YAP in alveolar regeneration and IPF pathogenesis. Our findings provide new insights to the regulation of alveolar regeneration and IPF pathogenesis, paving the road for developing novel treatment strategies.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), and is highly contagious and pathogenic. TMPRSS2 and Neuropilin-1, the key components that facilitate SARS-CoV-2 infection, are potential targets for treatment of COVID-19. Here we performed a comprehensive analysis on NRP1 and TMPRSS2 in lung to provide information for treating comorbidity of COVID-19 with lung cancer. NRP1 is widely expressed across all the human tissues while TMPRSS2 is expressed in a restricted pattern. High level of NRP1 associates with worse prognosis in multiple cancers, while high level of TMPRSS2 is associated with better survival of Lung Adenocarcinoma (LUAD). Moreover, NRP1 positively correlates with the oncogenic Cancer Associated Fibroblast (CAF), macrophage and endothelial cells infiltration, negatively correlates with infiltration of CD8+ T cell, the tumor killer cell in Lung Squamous cell carcinoma (LUSC). TMPRSS2 shows negative correlation with the oncogenic events in LUAD. RNA-seq data show that NRP1 level is slightly decreased in peripheral blood of ICU admitted COVID-19 patients, unaltered in lung, while TMPRSS2 level is significantly decreased in lung of COVID-19 patients. Our analysis suggests NRP1 as a potential therapeutic target, while sets an alert on targeting TMPRSS2 for treating comorbidity of COVID-19 and lung cancers.

Lung squamous cell carcinoma (LUSC) accounts for approximately 25% to 30% of lung cancers, but largely no targeted therapy is available against it, calling for identification of new oncogenes in LUSC growth for new therapeutic targets. In this study, REL was identified through a screening for oncogenes that are highly amplified in human LUSC. Its expression was associated with poor prognosis in LUSC patients. Furthermore, knockdown of c-Rel in LUSC cell lines lead to significant decrease in cell proliferation and migration. Mechanistically, c-Rel knockdown suppressed NFκB pathway by blocking phosphorylation of IκB. Consistently, pharmaceutic inhibition of c-Rel also. In orthotopic xenograft lung cancer mouse model, c-Rel knockdown inhibited the tumor growth. Cancer cell proliferation and epithelial-mesenchymal-transition (EMT) of the tumors were impaired by c-Rel knockdown. Finally, it's confirmed in precision-cut tumor slices of LUSC that deletion of c-Rel inhibits the NFκB pathway and cancer cell growth. Accordingly, we hypothesize that c-Rel promotes the activation of the NFκB pathway by promoting the phosphorylation of IκB in LUSC. Our study reveals REL as a novel LUSC oncogene and provides new insights into the molecular regulation of LUSC, which will provide new therapeutic targets for the treatment of squamous lung cancer.

Animal models play a crucial role in understanding disease mechanisms and testing potential therapeutic approaches. However, traditional murine models of idiopathic pulmonary fibrosis (IPF) that rely on a single-dose bleomycin injection fail to accurately replicate the complex pathological features observed in IPF patients. This study introduces an improved method using two successive oropharyngeal administrations of bleomycin in mice, which more effectively mimics the progression of IPF. This novel protocol induces key pathological changes, such as the formation of honeycomb-like cysts, fibroblastic foci, and bronchiolization of the alveolar epithelium, closely resembling the histopathology seen in human IPF. By utilizing this model, we are able to capture the progressive fibrotic changes over a longer time frame, which provides more reliable insights into the pathogenesis of IPF. Furthermore, this two-dose approach offers several advantages over conventional single-dose models, including better reproducibility and a more robust representation of the disease's development. This method enhances our ability to study the mechanisms underlying IPF and evaluate potential therapeutic interventions. The proposed protocol offers significant advancement in preclinical research and provides a valuable tool for investigating both the biology of pulmonary fibrosis and the efficacy of novel treatments.

Drosha is a critical regulator of kidney development; its loss or mutation, identified in a subset of Wilms tumor (WT), a pediatric kidney cancer, leads to nephric cap mesenchyme developmental defects. Here, we investigated the role of Drosha in mesangial cells and its impact on glomerular capillary tuft formation. Mesangial cells specific deletion of Drosha (Drosha cKO) in mouse model was generated. Deletion of Drosha in mesangial cells disrupted the glomerular capillary tufts formation, leading to dysplastic glomeruli, proteinuria, oliguria, reduced looping of glomerular capillaries and capillary dilation. Drosha knockdown in mesangial cells (SV40 MES 13) leads to decreased cell proliferation and reduced Gata3 protein level. Transcriptome analysis by RNA-seq shows decreased levels of ribosomal protein genes (RPGs) but unaltered mRNA levels of major genes affecting kidney development, including Gata3, Pax2, Atn1, Wt1 etc., in Drosha-KD compared to Control SV40 MES13 cells. Further analysis indicates Drosha regulates the translation of Gata3 in mesangial cells via regulating RPG transcription. Removal of Drosha in adult mesangial cells did not cause significant kidney dysfunction, indicating that Drosha functions primarily during development rather than in homeostasis. Our work reveals that Drosha in mesangial cells orchestrates the formation of glomerular capillary tufts by regulating Gata3 translation. It identifies the critical role of DROSHA in nephric development and proposes DROSHA as a novel potential causal gene for congenital anomalies of the kidney and the urinary tract (CAKUT).