CAREER: Illuminating the Effects of Hypoxia on Macrophage-Epithelial Crosstalk in Engineered 3D environments

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

Maintenance of oxygen balance is critical for development, growth and repair in both healthy and diseased tissues. When oxygen supply is lower than demand (hypoxia), such as in tissue injury, host cells secrete signals to initiate repair processes. These secreted signals can be derived from epithelial cells that form a protective barrier in different organs (e.g., lungs). Macrophages, a key cell type in tissue homeostasis, integrate these signals to dynamically respond to their environment. The broader goal of this CAREER project is to advance the engineering science and biological understanding of cell-cell communication mechanisms under hypoxia. This will be accomplished by developing a microfluidic technology to faithfully model the interactions of macrophages with epithelial cells in a dynamic 3D environment. The proposed research will be integrated into an educational and outreach program at the pre-college and college levels. Underrepresented high-school students will be introduced to concepts of transport phenomena in immune cell function through a hands-on microfluidic camp, and every summer, one high school student will be hosted in the investigator’s lab for a mentored research program. Through collaboration with the Young Women in Bio and the Leading for Life organizations the investigator will develop outreach activities to attract women in STEM. Finally, results from the research objective on oxygen and secreted signal transport will be integrated into classroom activities at the graduate level. The investigator’s long-term research goal is to create and use engineering approaches to elucidate the mechanisms influencing cellular adaptation under dysregulated oxygen levels and to actively modulate these mechanisms to restore homeostatic cellular function. To address this need, a novel microfluidic platform with integrated on-demand oxygen delivery will be engineered. This microfluidic technology will be used to dissect oxygen-regulated macrophage-epithelial crosstalk mechanisms that impact macrophage recruitment and proinflammatory cytokine profiles in a 3D collagen matrix. Furthermore, the effects of re-oxygenation on cellular stress pathways in hypoxia-conditioned macrophage-epithelial cocultures will be evaluated. Successful completion of the proposed work will yield 1) crucial advances in the fundamental understanding of how oxygen impacts key processes in macrophages including cell migration and 2) strategies to mitigate the proinflammatory state induced by hypoxic stress. In addition, this knowledge will facilitate the identification of novel targets for restoring tissue homeostasis and will impact the future design of experimental platforms to study cell migration in tissue morphogenesis and disease states. This approach can be extended to (a) study how dysregulated oxygen levels control additional fundamental processes, including nutrient uptake in tissue homeostasis, and (b) design new tissue-engineered systems with multi-parametric control of oxygen and biochemical inputs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.