Introduction: Carbamoylated erythropoietin (CEPO) is a chemically engineered, nonhematopoietic derivative of erythropoietin (EPO) that retains its antidepressant and pro-cognitive effects, which are attributed to the increased expression of neurotrophic factors like brain derived neurotrophic factor (BDNF), in the central nervous system. However, the chemical modification process which produces CEPO from erythropoietin (EPO) requires pure EPO as raw material, is challenging to scale-up and can also cause batch-to-batch variability. To address these key limitations while retaining its behavioral effects, we designed, expressed and analyzed a triple, glutamine, substitution recombinant mimetic of CEPO, named QPO.
Methods and Materials: We employ a combination of computational structural biology, molecular, cellular and behavioral assays to design, produce, purify and test QPO.
Results: QPO was shown to be a nonhematopoietic polypeptide with significant antidepressant-like and pro-cognitive behavioral effects in rodent assays while significantly upregulating BDNF expression in-vitro and in-vivo. The in-silico binding affinity analysis of QPO bound to the EPOR/EPOR homodimer receptor shows significantly decreased binding to Active Site 2, but not Active Site 1, of EPOR.
Discussion: The results of the behavioral and gene expression analysis imply that QPO is a successful CEPO mimetic protein and potentially acts via a similar neurotrophic mechanism, making it a drug development target for psychiatric disorders. The decreased binding to Active Site 2 could imply that this active site is not involved in neuroactive signaling and could allow the development of a functional innate repair receptor (IRR) model. Substituting the three glutamine substitution residues with arginine (RPO) resulted in the loss of behavioral activity, indicating the importance of glutamine residues at those positions.

Keywords: carbamoylated erythropoietin, mimetic, antidepressant, innate repair receptor, erythropoietin receptor, nonhematopoietic


中文翻译：

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行为活性重组神经营养因子的设计与开发

简介：氨基甲酰化促红细胞生成素 (CEPO) 是促红细胞生成素 (EPO) 的化学工程非造血衍生物，保留了其抗抑郁和促认知作用，这归因于脑源性神经营养因子 (BDNF) 等神经营养因子的表达增加，在中枢神经系统。然而，从促红细胞生成素 (EPO) 生产 CEPO ​​的化学修饰过程需要纯 EPO 作为原料，难以扩大规模，并且还会导致批次间差异。为了在保留其行为影响的同时解决这些关键限制，我们设计、表达并分析了 CEPO ​​的三重谷氨酰胺替代重组模拟物，命名为 QPO。
方法和材料：我们结合计算结构生物学、分子、细胞和行为分析来设计、生产、纯化和测试 QPO。
结果： QPO 被证明是一种非造血多肽，在啮齿动物试验中具有显着的抗抑郁样和促认知行为作用，同时在体外和体内显着上调 BDNF 表达。结合 EPOR/EPOR 同型二聚体受体的 QPO 的计算机结合亲和力分析显示，与 EPOR 的活性位点 2 而非活性位点 1 的结合显着降低。
讨论：行为和基因表达分析的结果表明，QPO 是一种成功的 CEPO ​​模拟蛋白，并可能通过类似的神经营养机制发挥作用，使其成为精神疾病的药物开发靶点。与活性位点 2 的结合减少可能意味着该活性位点不参与神经活性信号传导，并可能允许开发功能性先天修复受体 (IRR) 模型。用精氨酸 (RPO) 取代三个谷氨酰胺取代残基导致行为活性丧失，表明谷氨酰胺残基在这些位置的重要性。

关键词：氨基甲酰化促红细胞生成素，模拟物，抗抑郁药，先天修复受体，促红细胞生成素受体，非造血