Department of Pathology, University of North Dakota, School of Medicine and Health Sciences, 1301 N. Columbia Road, Stop 9037, Grand Forks, ND 58202, United States of America.
Toxicol Appl Pharmacol. 2019 Jul 15;375:5-16. doi: 10.1016/j.taap.2019.05.007. Epub 2019 May 9.
Stem/progenitor cells are involved in the regeneration of the renal tubules after damage due to a toxic insult. However, the mechanism involved in the regeneration of the tubules by the stem cells is not well understood due to the lack of immortal cell lines that represent the stem/progenitor cells of the kidney. A previous study from our laboratory has shown that the immortalized cell line RPTEC/TERT1 contains two populations of cells, one co-expressing CD24 and CD133, the other expressing CD24 only. The goal of the present study was to determine if both these populations could be sorted into separate independent cultures and if so, determine their characteristic features and response to the nephrotoxicant cadmium. The results of our study show that both the populations of cells could grow as independent cultures and maintain their phenotype after extended sub-culture. The CD133/CD24 co-expressing cells formed multicellular spheroids (nephrospheres), a characteristic feature of stem/progenitor cells, and formed branched tubule-like structures when grown on the surface of matrigel, whereas the CD133/CD24 cells were unable to form these structures. The CD133/CD24 cells were able to grow and undergo neurogenic, adipogenic, osteogenic, and tubulogenic differentiation, whereas the CD133/CD24 cells expressed some of the differentiation markers but were unable to grow in some of the specialized growth media. The CD133/ CD24 co-expressing cells had a shorter doubling time compared to the cells that expressed only CD24, and were more resistant to the toxic effects of the heavy metal, cadmium. In conclusion, the isolation and characterization of these two cell populations form the RPTEC/TERT1 cell line will facilitate the development of studies that determine the mechanisms involved in tubular damage and regeneration particularly after a toxic insult.
干细胞/祖细胞参与肾小管在毒性损伤后的再生。然而,由于缺乏代表肾脏干细胞/祖细胞的永生化细胞系,因此对于干细胞如何再生小管的机制还了解甚少。我们实验室的一项先前研究表明,永生化细胞系 RPTEC/TERT1 包含两种细胞群体,一种共同表达 CD24 和 CD133,另一种仅表达 CD24。本研究的目的是确定这两种细胞群体是否可以被分离到单独的独立培养物中,如果可以,那么确定它们的特征和对肾毒性物质镉的反应。我们的研究结果表明,这两种细胞群体都可以作为独立的培养物生长,并在延长的亚培养后保持其表型。CD133/CD24 共表达细胞形成多细胞球体(肾球体),这是干细胞/祖细胞的特征,并且当在基质胶表面上生长时形成分支管状结构,而 CD133/CD24 细胞则无法形成这些结构。CD133/CD24 细胞能够生长并经历神经发生、脂肪生成、成骨和管状分化,而 CD133/CD24 细胞表达一些分化标记物,但无法在一些专门的生长培养基中生长。与仅表达 CD24 的细胞相比,CD133/CD24 共表达细胞的倍增时间更短,并且对重金属镉的毒性作用更具抵抗力。总之,这些两种细胞群体的分离和鉴定将促进研究肾小管损伤和再生机制的发展,特别是在受到毒性损伤后。