Neuronal anatomy, connectivity, and phenotypic innervation of the knee joint

项目总结 识别神经元连接的模式对于理解功能和解剖回路至关重要 调节痛觉。然而，关于关节组织中神经元的类型和分布的知识 一般限于传统的二维组织病理学和免疫组织病理学方法， 关于连接性和神经元表型的信息很少，甚至没有。新技术已经 允许跨突触电路分析和对神经元放电的精确控制的出现，包括 利用逆行运输的病毒载体(即伪型狂犬病病毒)和异源受体 激活。同时，神经元和血管模式的三维可视化已经被 先进的组织清除技术与由 交叉细胞型特异性Cre重组酶小鼠品系与各种条件激活的报告。 最后，单细胞rna测序的出现允许将细胞表型分析扩展到分子。 不仅提高了分析分辨率，而且还提高了针对更大疾病的治疗目标 比以前可能的更具特异性。高分辨率空间转录组的发展，也就是鱼， 允许关联和验证scRNA-seq数据。在这种情况下，膝关节骨关节炎是一种 应用这些工具的最佳模型，因为有大量的遗传和手术模型可用于正交表 对调查结果的验证。此外，在临床前背景下，包括基因在内的各种治疗方法 治疗已被证明影响疼痛措施，因此，它们构成了一种重要的干预措施。 确认处于疾病状态的神经元中已识别的分子变化。事实上，其中一些 目前正在进行临床试验的治疗方法增加了拟议的临床前发现的潜在翻译影响 这里。最终，解剖学、3D和分子签名的结合将有助于翻译 进入人体组织和活组织，同时最大限度地增加相关新治疗靶点的可能性。

PROJECT SUMMARY Identifying patterns of neuronal connectivity is critical for understanding functional and anatomical circuits that mediate pain perception. However, knowledge about the types and distribution of neurons in joint tissues have generally been limited to traditional 2-dimension histopathological and immunohistopathological approaches, and little to no information is available on connectivity and neuronal phenotypes. New technologies have emerged that allow for both trans-synaptic circuit analysis and precise control of neuronal firing, including the use of retrogradely transported viral vectors (i.e., pseudotyped rabies virus) and heterologous receptor activation. At the same time, 3-dimensional visualization of neuronal and vascular patterns have been advanced by tissue clearing techniques in conjunction with cell type specific fluorescent markers generated by intercrossing cell type specific Cre recombinase mouse lines with a variety of conditionally activated reporters. Finally, the advent of single cell RNA sequencing has allowed for extending cellular phenotyping to a molecular level that has not only increases analytic resolution, but also therapeutic targeting with greater disease specificity than previously possible. The development of high resolution spatial transcriptomics, i.e., MERFISH, allows for correlation and validation of scRNA-seq data. In this context, osteoarthritis of the knee joint is an optimal model for applying these tools as abundant genetic and surgical models are available for orthogonal validation of findings. Moreover, in the preclinical context, various therapeutic approaches including gene therapy have been shown to impact pain measures, and as such, they constitute an important interventional validation of molecular changes that are identified in neurons in the disease state. The fact that some of these therapies are now in clinical trial adds to the potential translational impact of the proposed preclinical findings here. Ultimately, the combination of both anatomic, 3-D, and molecular signatures will facilitate the translation into human tissues and biopsies, while maximizing the likelihood of relevant new therapeutic targets.