Poster #027, Charles R. Drew University of Medicine and Science
Profiling Extracellular Matrix Signaling in Trisomy 21 Lung Fibroblast Derived Extracellular Vesicles
Mentors: Denise Al Alam, PhD and Soula Danopoulos, PhD
Trisomy 21 (T21), the genetic cause of Down syndrome (DS), results from the triplication of chromosome 21. Pulmonary complications are a leading cause of morbidity and mortality in individuals with DS. Our group has shown these defects affect several components of the developing lung, including the extracellular matrix (ECM). Additionally, T21 lung fibroblasts, key producers of ECM, can alter the morphology and composition of non-T21 cells even without direct cell-to-cell contact. Extracellular vesicles (EVs), membrane-bound particles that mediate intercellular communication by transporting bioactive cargo, may contribute to this effect. Therefore, we aimed to evaluate differences in ECM-associated factors carried by EVs derived from T21 and Non-T21 lung fibroblasts. Three pairs of T21 and non-T21 postnatal human lung fibroblasts (HLFs) were cultured in DMEM/F12 with 10% FBS to 80% confluency, then switched to EV-depleted medium for 72 hours. Conditioned media was collected, EVs were isolated and quality-checked, and EV proteins were extracted, quantified, and analyzed by western blotting. Additionally, conditioned media from T21 and non-T21 HLF was transferred to cultures of the opposite genotype to determine whether secreted factors could modulate ECM-associated gene expression. Non-T21 HLFs exposed to conditioned media from T21 fibroblasts showed significant changes in expression of ECM-associated genes, suggesting that secreted factors influence recipient cells. EVs isolated from T21 and non-T21 HLF were positive for EpCam, Annexin A5, TSG101, CD81, ICAM and ALIX, confirming successful EV isolation. Further characterization of EV protein cargo by Western blot will determine whether EV-mediated transfer of ECM-related factors contributes to altered matrix composition and function in T21 lungs. Together, the observed changes in morphology and cell composition in the absence of direct cell-to-cell contact, along with altered ECM-associated gene expression following conditioned media transfer, suggest the possibility that ECM signaling mediated by Trisomy 21 lung fibroblast derived EVs is dysregulated.