Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606 8502, Japan.
Department of Food Science and Nutrition, Faculty of Human Life and Environment, Nara Women‛s University, Nara 630 8506, Japan.
Int J Mol Sci. 2019 Dec 28;21(1):229. doi: 10.3390/ijms21010229.
Prolyl-hydroxyproline (Pro-Hyp) and hydroxyprolyl-glycine (Hyp-Gly) appear in human blood after ingestion of collagen hydrolysate and trigger growth of fibroblasts attached on collagen gel, which has been associated with beneficial effects upon ingestion of collagen hydrolysate, such as improvement of skin and joint conditions. In the present study, inconsistent results were obtained by using different lots of fetal bovine serum (FBS). Fibroblasts proliferated in collagen gel without adding Pro-Hyp and Hyp-Gly and did not respond to addition of Pro-Hyp and Hyp-Gly, which raises doubts about conclusions from prior research. Unexpectedly high levels of hydroxyprolyl peptides, including Pro-Hyp, however, were present in the FBS (approximately 100 µM), and also in other commercially available forms of FBS (70-80 µM). After removal of low molecular weight (LMW, < 6000 Da) compounds from the FBS by size exclusion chromatography, Pro-Hyp and Hyp-Gly again triggered growth of fibroblasts attached on collagen and increased the number of fibroblasts migrated from mouse skin. These results indicate the presence of bioactive hydroxyprolyl peptides in commercially available FBS, which can mask effects of Pro-Hyp and Hyp-Gly supplementation; our work confirms that Pro-Hyp and Hyp-Gly do play crucial roles in proliferation of fibroblasts.
脯氨酰-羟脯氨酸（Pro-Hyp）和羟脯氨酸-甘氨酸（Hyp-Gly）在摄入胶原水解物后会出现在人体血液中，并触发附着在胶原凝胶上的成纤维细胞生长，这与摄入胶原水解物的有益效果有关，例如改善皮肤和关节状况。在本研究中，使用不同批次的胎牛血清（FBS）得到了不一致的结果。成纤维细胞在没有添加 Pro-Hyp 和 Hyp-Gly 的情况下在胶原凝胶中增殖，并且对添加 Pro-Hyp 和 Hyp-Gly 没有反应，这使人对先前研究的结论产生了怀疑。然而，出人意料的是，FBS（约 100 µM）中存在高水平的羟脯氨酸肽，包括 Pro-Hyp，以及其他市售形式的 FBS（70-80 µM）中也存在高水平的羟脯氨酸肽。通过大小排阻层析法从 FBS 中去除低分子量（LMW，<6000 Da）化合物后，Pro-Hyp 和 Hyp-Gly 再次触发附着在胶原上的成纤维细胞生长，并增加了从小鼠皮肤迁移的成纤维细胞数量。这些结果表明，市售 FBS 中存在具有生物活性的羟脯氨酸肽，这可能掩盖了 Pro-Hyp 和 Hyp-Gly 补充的作用；我们的工作证实 Pro-Hyp 和 Hyp-Gly 确实在成纤维细胞增殖中发挥关键作用。
