Disrupted blood flow in conditions such as peripheral artery disease and critical limb ischemia leads to variations in oxygen supply within skeletal muscle tissue, creating regions of poorly perfused, hypoxic skeletal muscle surrounded by regions of adequately perfused, normoxic muscle tissue. These oxygen gradients may have significant implications for muscle injury or disease, as mediated by the exchange of paracrine factors between differentially oxygenated tissue. However, creating and maintaining heterogeneous oxygen landscapes within a controlled experimental setup to ensure continuous paracrine signaling is a technological challenge. Here, we engineer oxygen-controlled microphysiological systems to investigate paracrine interactions between differentially oxygenated engineered muscle tissue. We fabricated microphysiological systems with dual oxygen landscapes that also had engineered control over paracrine interactions between hypoxic and normoxic skeletal muscle tissues, which were differentiated from C2C12 myoblasts cultured on micromolded gelatin hydrogels. The microphysiological systems interfaced with a new 3D-printed oxygen control well plate insert, which we designed to distribute flow to multiple microphysiological systems and minimize evaporation for longer timepoints. With our system, we demonstrated that amphiregulin, a myokine associated with skeletal muscle injury, exhibits unique upregulation in both gene expression and secretion after 24 hours due to paracrine interactions between hypoxic and normoxic skeletal muscle tissue. Our platform can be extended to investigate other impacts of paracrine interactions between hypoxic and normoxic skeletal muscle and can more broadly be used to elucidate many forms of oxygen-dependent crosstalk in other organ systems.

中文翻译：

---

分析由 3D 打印组件制造的微生理系统中缺氧和常氧骨骼肌组织之间的旁分泌相互作用。


在外周动脉疾病和严重肢体缺血等情况下，血流中断会导致骨骼肌组织内的氧气供应发生变化，从而产生灌注不良、缺氧的骨骼肌区域，周围环绕着灌注充分的正常氧肌组织区域。这些氧梯度可能对肌肉损伤或疾病有重大影响，这是由差氧组织之间的旁分泌因子交换介导的。然而，在受控实验装置中创建和维持异质氧景观以确保连续的旁分泌信号传导是一项技术挑战。在这里，我们设计了氧控微生理系统，以研究差别氧工程肌肉组织之间的旁分泌相互作用。我们制造了具有双氧景观的微生理系统，该系统还工程控制了缺氧和常氧骨骼肌组织之间的旁分泌相互作用，这与在微成型明胶水凝胶上培养的 C2C12 成肌细胞不同。微生理系统与新的 3D 打印氧气对照孔板插件连接，我们将其设计为将流量分配到多个微生理系统，并最大限度地减少较长时间点的蒸发。通过我们的系统，我们证明了双调蛋白是一种与骨骼肌损伤相关的肌因子，由于缺氧和常氧骨骼肌组织之间的旁分泌相互作用，24 小时后基因表达和分泌都表现出独特的上调。 我们的平台可以扩展到研究缺氧和常氧骨骼肌之间旁分泌相互作用的其他影响，并且可以更广泛地用于阐明其他器官系统中多种形式的氧依赖性串扰。