Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China.
Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China.
Dev Comp Immunol. 2021 Aug;121:104097. doi: 10.1016/j.dci.2021.104097. Epub 2021 Apr 6.
β-Thymosin is a multifunctional peptide ubiquitously expressed in vertebrates and invertebrates. Many studies have found β-thymosin is critical for wound healing, angiogenesis, cardiac repair, hair regrowth, and anti-fibrosis in vertebrates, and plays an important role in antimicrobial immunity in invertebrates. However, whether β-thymosin participates in the regeneration of organisms is still poorly understood. In this study, we identified a β-thymosin gene in Dugesia japonica which played an important role in stem cell proliferation and neuron regeneration during the tissue repair process in D. japonica. Sequencing analysis showed that β-thymosin contained two conserved β-thymosin domains and two actin-binding motifs, and had a high similarity with other β-thymosins of invertebrates. In situ or fluorescence in situ hybridization analysis revealed that Djβ-thymosin was co-localized with DjPiWi in the neoblast cells of intact adult planarians and the blastema of regenerating planarians, suggesting Djβ-thymosin has a potential function of regeneration. Disruption Djβ-thymosin by RNA interference results in a slightly curled up head of planarian and stem cell proliferation defects. Additionally, we found that, upon amputation, Djβ-thymosin RNAi-treated animals had impaired regeneration ability, including impaired blastema formation, delayed eyespot formation, decreased brain area, and disrupted central CNS formation, implying Djβ-thymosin is an essential regulator of stem cell proliferation and neuron regeneration.
β-胸腺素是一种多功能肽，广泛存在于脊椎动物和无脊椎动物中。许多研究发现，β-胸腺素对脊椎动物的伤口愈合、血管生成、心脏修复、毛发再生和抗纤维化至关重要，并在无脊椎动物的抗菌免疫中发挥重要作用。然而，β-胸腺素是否参与生物体的再生仍知之甚少。在这项研究中，我们在日本三角涡虫中鉴定出一种β-胸腺素基因，该基因在三角涡虫组织修复过程中对干细胞增殖和神经元再生起着重要作用。测序分析表明，β-胸腺素含有两个保守的β-胸腺素结构域和两个肌动蛋白结合基序，与其他无脊椎动物的β-胸腺素有很高的相似性。原位杂交或荧光原位杂交分析显示，Djβ-胸腺素与 DjPiWi 在完整成年涡虫的成体干细胞和再生涡虫的芽基中共同定位，提示 Djβ-胸腺素有潜在的再生功能。通过 RNA 干扰破坏 Djβ-胸腺素会导致涡虫头部略微卷曲和干细胞增殖缺陷。此外，我们发现，在截肢后，接受 Djβ-胸腺素 RNAi 处理的动物再生能力受损，包括芽基形成受损、眼斑形成延迟、脑区减少和中枢神经系统形成中断，这表明 Djβ-胸腺素是干细胞增殖和神经元再生的必需调节剂。
