Zhou Yiqin, Zhang Jianying, Wu Haishan, Hogan MaCalus V, Wang James H-C
MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, 210 Lothrop Street, BST, E1640, Pittsburgh, PA, 15213, USA.
Joint Surgery and Sports Medicine Department, Shanghai Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Huangpu, Shanghai, 200003, China.
Stem Cell Res Ther. 2015 Sep 15;6(1):173. doi: 10.1186/s13287-015-0172-4.
Platelet-rich plasma (PRP) is widely used to treat tendon injuries in clinics. These PRP preparations often contain white blood cells or leukocytes, and the precise cellular effects of leukocyte-rich PRP (L-PRP) on tendons are not well defined. Therefore, in this study, we determined the effects of L-PRP on tendon stem/progenitor cells (TSCs), which play a key role in tendon homeostasis and repair.
TSCs isolated from the patellar tendons of rabbits were treated with L-PRP or P-PRP (pure PRP without leukocytes) in vitro, followed by measuring cell proliferation, stem cell marker expression, inflammatory gene expression, and anabolic and catabolic protein expression by using immunostaining, quantitative real-time polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay, respectively.
Cell proliferation was induced by both L-PRP and P-PRP in a dose-dependent manner with maximum proliferation at a 10 % PRP dose. Both PRP treatments also induced differentiation of TSCs into active tenocytes. Nevertheless, the two types of PRP largely differed in several effects exerted on TSCs. L-PRP induced predominantly catabolic and inflammatory changes in differentiated tenocytes; its treatment increased the expression of catabolic marker genes, matrix metalloproteinase-1 (MMP-1), MMP-13, interleukin-1beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α), and their respective protein expression and prostaglandin E2 (PGE 2) production. In contrast, P-PRP mainly induced anabolic changes; that is, P-PRP increased the gene expression of anabolic genes, alpha-smooth muscle actin (α-SMA), collagen types I and III.
These findings indicate that, while both L-PRP and P-PRP appear to be "safe" in inducing TSC differentiation into active tenocytes, L-PRP may be detrimental to the healing of injured tendons because it induces catabolic and inflammatory effects on tendon cells and may prolong the effects in healing tendons. On the other hand, when P-PRP is used to treat acutely injured tendons, it may result in the formation of excessive scar tissue due to the strong potential of P-PRP to induce inordinate cellular anabolic effects.
富含血小板血浆（PRP）在临床上被广泛用于治疗肌腱损伤。这些PRP制剂通常含有白细胞，而富含白细胞的PRP（L-PRP）对肌腱的确切细胞效应尚不清楚。因此，在本研究中，我们确定了L-PRP对肌腱干/祖细胞（TSCs）的影响，TSCs在肌腱内环境稳定和修复中起关键作用。
从兔髌腱分离的TSCs在体外分别用L-PRP或P-PRP（不含白细胞的纯PRP）处理，然后分别通过免疫染色、定量实时聚合酶链反应、蛋白质印迹和酶联免疫吸附测定来测量细胞增殖、干细胞标志物表达、炎症基因表达以及合成代谢和分解代谢蛋白表达。
L-PRP和P-PRP均以剂量依赖方式诱导细胞增殖，在10%PRP剂量时增殖达到最大值。两种PRP处理也均诱导TSCs分化为活跃的肌腱细胞。然而，两种类型的PRP对TSCs产生的几种效应有很大差异。L-PRP主要在分化的肌腱细胞中诱导分解代谢和炎症变化；其处理增加了分解代谢标志物基因基质金属蛋白酶-1（MMP-1）、MMP-13、白细胞介素-1β（IL-1β）、IL-6和肿瘤坏死因子-α（TNF-α）的表达，以及它们各自的蛋白表达和前列腺素E2（PGE2）的产生。相比之下，P-PRP主要诱导合成代谢变化；也就是说，P-PRP增加了合成代谢基因α-平滑肌肌动蛋白（α-SMA）、I型和III型胶原蛋白的基因表达。
这些发现表明，虽然L-PRP和P-PRP在诱导TSCs分化为活跃的肌腱细胞方面似乎都是“安全的”，但L-PRP可能对受伤肌腱的愈合有害，因为它对肌腱细胞诱导分解代谢和炎症作用，并可能延长肌腱愈合中的效应。另一方面，当使用P-PRP治疗急性损伤的肌腱时，由于P-PRP诱导过度细胞合成代谢效应的强大潜力，可能导致形成过多的瘢痕组织。
Zotero 插件
