Stanulis-Praeger B M, Yaar M, Redziniak G, Meybeck A, Gilchrest B A
United States Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.
J Invest Dermatol. 1988 May;90(5):749-54. doi: 10.1111/1523-1747.ep12560950.
An extract prepared from newborn calf thymus stimulated proliferation of human keratinocytes cultured from newborn foreskins and from skin biopsies of 26 adult volunteers aged 19 to 70 years. Growth over the 7-day assay period in the basal medium was age-dependent, with newborn cultures achieving a 10-fold increase in cell number over seeding density, old adult cultures barely maintaining their seeding density and young adult cultures intermediate in proliferative capacity. Maximally stimulatory extract concentration was 5-fold higher for newborn than for adult keratinocytes, with adult cultures experiencing toxicity at doses still growth-promoting for newborn cultures. At optimal extract concentration the maximal average increase in cell yield (66.3% for newborn, 53.6% for young adult, and 18.1% for old) indicated decreased mitogen responsiveness or increased inhibitor sensitivity with increasing donor age. Stimulation of cholera toxin-treated cultures was equally high, ranging from 39.4% to 145.9%, suggesting that the extract acts through a cyclic AMP-independent pathway. Thymic extract did not increase colony forming efficiency. Our findings provide further support for the concept of functional interactions between the skin and the immune system, in addition to the recognized morphologic similarities between thymic cells and keratinocytes. Furthermore, these data confirm earlier findings of an inverse relationship between mitogen responsiveness and donor age for cultured cells.
从新生小牛胸腺制备的提取物可刺激源自新生儿包皮以及26名年龄在19至70岁之间的成年志愿者皮肤活检样本所培养的人角质形成细胞的增殖。在基础培养基中进行的7天检测期内，细胞生长呈现出年龄依赖性，新生样本培养物的细胞数量相对于接种密度增加了10倍，老年成年样本培养物几乎无法维持其接种密度，而年轻成年样本培养物的增殖能力则处于中间水平。对于新生角质形成细胞，最大刺激提取物浓度比成年角质形成细胞高5倍，在对新生样本培养物仍具有促生长作用的剂量下，成年样本培养物会出现毒性。在最佳提取物浓度下，细胞产量的最大平均增加量（新生样本为66.3%，年轻成年样本为53.6%，老年样本为18.1%）表明，随着供体年龄的增加，有丝分裂原反应性降低或抑制剂敏感性增加。对经霍乱毒素处理的培养物的刺激同样很高，范围在39.4%至145.9%之间，这表明该提取物通过一条不依赖环磷酸腺苷的途径发挥作用。胸腺提取物并未提高集落形成效率。我们的研究结果为皮肤与免疫系统之间功能相互作用的概念提供了进一步支持，此外，胸腺细胞与角质形成细胞之间也存在公认的形态学相似性。此外，这些数据证实了早期关于培养细胞有丝分裂原反应性与供体年龄之间呈负相关的研究结果。
