Angiotensin-converting enzyme 2 in peripheral lung club cells modulates the susceptibility to SARS-CoV-2 in chronic obstructive pulmonary disease.

Accumulating evidence has confirmed that chronic obstructive pulmonary disease (COPD) is a risk factor for development of severe pathological changes in the peripheral lungs of patients with COVID-19. However, the underlying molecular mechanisms remain unclear. Because bronchiolar club cells are crucial for maintaining small airway homeostasis, we sought to explore whether the altered susceptibility to SARS-CoV-2 infection of the club cells might have contributed to the severe COVID-19 pneumonia in COPD patients.

[Expression of HOXC4 gene during early development in zebrafish].

Objective: To investigate the mechanism of HOXC4 gene during early development in zebrafish, study it's expression in hematopoiesis system with whole mount in situ hybridization (WISH), then make a foundation work for further study of HOXC4 gene in hematopoiesis development.

Methods: The total RNA of different phases of zebrafish embryos was extracted, and a fragment of HOXC4 gene was cloned with RT-PCR, then HOXC4 gene fragment and pCS2 was digested with BamH I and Xho I restriction enzyme, after that HOXC4 gene fragment was inserted into pCS2+ vector. After confirming the constructed plasmid, the digoxingenin-labeled anti-sence mRNA probe of HOXC4 gene was synthesized in vitro by using T3 RNA polymerase, the exprression pattern of HOXC4 during zebrafish embryogenesis using anti-sence probe with WISH was conducted.

[Expression pattern of hoxd3 gene during early development of wild-type zebrafish embryos].

Objective: To investigate the expression pattern of hoxd3 gene during early embryogenesis and angiogenesis of wild-type zebrafish.

Methods: Total RNA was extracted from embryos of zebrafish in different development stages by trizol. The cDNA of hoxd3 gene was amplified by RT-PCR.