{'fraction_non_alphanumeric': 0.02517162471395881, 'fraction_numerical': 0.014492753623188406, 'mean_word_length': 5.9787234042553195, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A comparative gene-expression analysis of CD34+ hematopoietic stem and progenitor cells grown in static and stirred culture systems

Static and stirred culture systems are widely used to expand hematopoietic cells, but differential culture performances are observed between these systems. We hypothesize that these differential culture outcomes are caused by the physiological responses of CD34(+) hematopoietic stem and progenitor cells (HSPCs) to the different physical microenvironments created in these culture devices. To understand the genetic changes provoked by culture microenvironments, the gene expression profiling of CD34(+) HSPCs grown in static and stirred culture systems was compared using SMART-PCR and cDNA arrays. The results revealed that 103 and 99 genes were significantly expressed in CD34(+) cells from static and stirred systems, respectively. Of those, 91 have similar levels of expression, while 12 show differential transcription levels. These differentially expressed genes are mainly involved in anti-oxidation, DNA repair, apoptosis, and chemotactic activity. A quantitative molecular understanding of the influences of growth microenvironments on transcriptional events in CD34(+) HSPCs should give new insights into optimizing culture strategies to produce hematopoietic cells.