Lung progenitors from lambs can differentiate into specialized alveolar or bronchiolar epithelial cells

Abstract

BackgroundAirways progenitors may be involved in embryogenesis and lung repair. The characterization of these important populations may enable development of new therapeutics to treat acute or chronic lung disease. In this study, we aimed to establish the presence of bronchioloalveolar progenitors in ovine lungs and to characterize their potential to differentiate into specialized cells.ResultsLung cells were studied using immunohistochemistry on frozen sections of the lung. Immunocytochemistry and flow cytometry were conducted on ex-vivo derived pulmonary cells. The bronchioloalveolar progenitors were identified by their co-expression of CCSP, SP-C and CD34. A minor population of CD34pos/SP-Cpos/CCSPpos cells (0.33% ± 0.31) was present ex vivo in cell suspensions from dissociated lungs. Using CD34 magnetic positive-cell sorting, undifferentiated SP-Cpos/CCSPpos cells were purified (>80%) and maintained in culture. Using synthetic media and various extracellular matrices, SP-Cpos/CCSPpos cells differentiated into either club cells (formerly named Clara cells) or alveolar epithelial type-II cells. Furthermore, these ex vivo and in vitro derived bronchioloalveolar progenitors expressed NANOG, OCT4 and BMI1, specifically described in progenitors or stem cells, and during lung development.ConclusionsWe report for the first time in a large animal the existence of bronchioloalveolar progenitors with dual differentiation potential and the expression of specialized genes. These newly described cell population in sheep could be implicated in regeneration of the lung following lesions or in development of diseases such as cancers.

Ovine Pulmonary Adenocarcinoma: A Unique Model to Improve Lung Cancer Research

“…However, the presence of BASC in humans and sheep has not been firmly established (95). Cells displaying some features of BASC have been described in sheep (72, 96) but their significance in OPA tumourigenesis remains unclear.…”

Gestational Exposure to Cigarette Smoke Suppresses the Gasotransmitter H2S Biogenesis and the Effects Are Transmitted Transgenerationally

“…Moreover, the concentrations of TGF-β by Western blot analysis ( Figure 1D ) and of the anti-asthmatic factor SOX2 by IHC ( Figure 1E ), were significantly lower in gestationally SS-exposed lungs. SOX2 is a pluripotent transcription factor in bronchoalveolar progenitors, which promotes the Club cells to express Clara-cell secretory protein (CCSP) and surfactant protein-C (SP-C) ( 54 ). CCSP and SP-C are suppressed by gestational SS ( 10 ) and reduced SOX2 and CCSP levels are associated with higher risk of asthma ( 55 ); humans and mice deficient in CCSP, exhibit airway hyperresponsiveness ( 56 ).…”

State of the art on lung organoids in mammals

“…Numerous reviews have described the different lung stem cells identified, mainly characterized in humans and mice [ 15 , 22 – 25 ]. Descriptions of lung stem cells in other medium and large mammals are still very sparse, except in our work on the identification of ovine bronchioloalveolar progenitors with dual differentiation potential [ 26 ].…”

“…To date the vast majority of in vitro lung models are developed from mouse and human tissues, with protocols published, describing the method used to isolate and cultivate primary adult lung epithelial cells alone or in coculture, as monolayers, as a polarized epithelium (2D) or at the air–liquid interface (ALI) [ 39 ]. Few data are available on other model species, especially those of agronomic interest, but we can point to several papers on porcine [ 40 ], bovine [ 41 – 44 ], equine [ 45 ] and ovine [ 26 , 46 ] lung cells. Primary adult differentiated lung epithelial cells remain difficult to isolate due to their low turn-over.…”