Mesenchymal stromal cells in the endosteal niche lining compact bone (CB-MSCs) represent a heterogeneous population, all of which contribute to bone repair and remodelling. Hyperglycaemia associated with type 2 diabetes mellitus (T2DM) can delay and impair the bone healing process. Therefore, this study investigated the influences of high (25 mM) glucose conditions on CB-MSC populations isolated from male Wistar rats, versus normal (5.5 mM) glucose conditions; in terms of proliferation (population doublings, PDs), senescence characteristics, stem cell marker expression, colony forming efficiencies (CFEs); and osteogenic/adipogenic differentiation, following extended culture in vitro. CB-MSCs under both normoglycaemic and hyperglycaemic conditions demonstrated similar morphologies and rapid exponential growth to >300PDs, although high glucose conditions promoted more rapid and persistent proliferation beyond ~50PDs, with few indications of senescence. Limited senescence was confirmed by minimal SA-β-galactosidase staining, low senescence marker (p53, p21waf1, p16INK4a) expression and positive telomere maintenance marker (rTERT, TR) expression. However, telomere lengths varied throughout culture expansion, with hyperglycaemia significantly reducing telomere lengths at PD50 and PD200. Furthermore, CB-MSCs expanded in normal and high glucose conditions remained non-transformed, exhibiting similar MSC (CD73/CD90/CD105), multipotency (CD146) and embryonic (Slug, Snail) markers throughout extended culture, but negligible hematopoietic (CD34/CD45) or pluripotency (Nanog, Oct4) markers. Hyperglycaemia significantly increased CFEs at PD50 and PD100, which decreased at PD200. CB-MSC osteogenic differentiation was also inhibited by hyperglycaemia at PD15, PD100 and PD200, but not at PD50. Hyperglycaemia inhibited CB-MSC adipogenic differentiation to a lesser extent at PD15 and PD50, with reduced adipogenesis overall at PD100 and PD200. This study demonstrates the limited negative impact of hyperglycaemia on the proliferative and stem cell characteristics of heterogeneous CB-MSC populations, although minor sub-population(s) appear more susceptible to these conditions leading to impaired osteogenic/adipogenic differentiation capabilities. Such findings potentially highlight the impact of hyperglycaemia on CB-MSC bone repair capabilities in situ.

中文翻译：

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高糖条件对大鼠内膜生壁生壁间充质基质细胞扩增和分化能力的影响

骨膜内生壁衬里致密骨（CB-MSC）中的间充质基质细胞代表异质群体，所有这些都有助于骨骼修复和重塑。与2型糖尿病（T2DM）相关的高血糖症会延迟并损害骨愈合过程。因此，本研究调查了高（25 mM）葡萄糖条件对从雄性Wistar大鼠分离的CB-MSC群体的影响，与正常（5.5 mM）葡萄糖条件相比；在增殖（种群倍增，PD），衰老特征，干细胞标志物表达，集落形成效率（CFE）方面；和体外培养后的成骨/成脂分化。在正常血糖和高血糖条件下的CB-MSCs表现出相似的形态，并迅速指数增长至> 300PDs，尽管高葡萄糖条件可促进〜50PDs以上的更快和持续的增殖，几乎没有衰老迹象。通过最小限度的SA-β-半乳糖苷酶染色，低衰老标记（p53，p21waf1，p16INK4a）表达和端粒维持阳性标记（rTERT，TR）表达，可以确认有限的衰老。但是，端粒长度在整个培养扩增过程中都不同，高血糖会显着降低PD50和PD200处的端粒长度。此外，在正常和高葡萄糖条件下扩增的CB-MSC仍未转化，在整个扩展培养过程中均表现出相似的MSC（CD73 / CD90 / CD105），多能性（CD146）和胚胎（Slug，Snail）标记，但造血能力可忽略不计（CD34 / CD45）或多能性（Nanog，Oct4）标记。高血糖会显着增加PD50和PD100的CFE，在PD200下降了。在PD15，PD100和PD200，高血糖也可抑制CB-MSC的成骨分化，但在PD50，则不会。高血糖症在PD15和PD50抑制CB-MSC的脂肪形成分化的程度较小，而在PD100和PD200总体上降低了脂肪形成。这项研究表明，高血糖症对异质CB-MSC群体的增殖和干细胞特征的负面影响有限，尽管较小的亚群似乎更容易受到这些条件的影响，从而导致成骨/成脂分化能力受损。这些发现潜在地突出了高血糖对原位CB-MSC骨修复能力的影响。高血糖症在PD15和PD50抑制CB-MSC的脂肪形成分化的程度较小，而在PD100和PD200总体上降低了脂肪形成。这项研究表明，高血糖症对异质CB-MSC群体的增殖和干细胞特征的负面影响有限，尽管较小的亚群似乎更容易受到这些条件的影响，从而导致成骨/成脂分化能力受损。这些发现潜在地突出了高血糖对原位CB-MSC骨修复能力的影响。高血糖症在PD15和PD50抑制CB-MSC的脂肪形成分化的程度较小，而在PD100和PD200总体上降低了脂肪形成。这项研究表明，高血糖症对异质CB-MSC群体的增殖和干细胞特征的负面影响有限，尽管较小的亚群似乎更容易受到这些条件的影响，从而导致成骨/成脂分化能力受损。这些发现潜在地突出了高血糖对原位CB-MSC骨修复能力的影响。尽管少数亚群似乎更容易受到这些条件的影响，从而导致成骨/成脂分化能力受损。这些发现潜在地突出了高血糖对原位CB-MSC骨修复能力的影响。尽管少数亚群似乎更容易受到这些条件的影响，从而导致成骨/成脂分化能力受损。这些发现潜在地突出了高血糖对原位CB-MSC骨修复能力的影响。