PhD Scientific Days 2021

PH_II_L: Pharmaceutical Sciences II. Lectures

Ischemic helium conditioning increases cardiac fibroblast migration which is not propagated via soluble factors or extracellular vesicles

Text of the abstract

Introduction: Helium inhalation and ischemic conditioning induce cardioprotection against ischemia/reperfusion injury, of which cellular mechanism is not fully elucidated. Extracellular vesicles (EVs) are cell-derived, nano-sized membrane vesicles which play role in cardioprotective mechanisms, but their function in helium-conditioning (HeC) has not been studied, yet.
Aims: We investigate how HeC affects cardiac fibroblasts, and if their HeC-induced EVs or other secreted factors propagate cardioprotection between cardiac cells.
Methods: Neonatal rat cardiac fibroblasts (NRCF) were exposed to glucose deprivation and HeC rendered by four cycles of 95% helium + 5% CO2 for one hour, followed by one hour normoxic condition. 40 hours after HeC NRCF activation was analyzed with Western blot (WB) and migration assays. From cell supernatant, large extracellular vesicles (lEVs) were isolated with differential centrifugation and analyzed with WB and nanoparticle tracking analysis. Supernatant from HeC-treated NRCF was transferred to naïve NRCF and immortalized human umbilical vein endothelia cells (HUVEC/TERT2) and migration and angiogenesis assay was performed.
Result: HeC accelerated the migration of NRCFs. Meanwhile, HeC did not increase the expression of markers of fibroblast activation, or secretion of lEVs from NRCF. HeC tend to decrease lEV secretion of NRCFs, but supernatant of HeC or CTRL NRCF did not accelerate the migration of naïve NRCF or affect angiogenic potential of HUVEC/TERT2.
Conclusion: Since HeC increased the migration of NRCF but did not induce myofibroblast transformation and since this effect was not transferable by EVs or soluble factors, HeC may alleviate acute myocardial damage, but may not have prolonged effect on long-term fibrosis or on post-ischemic revascularization.

University and Doctoral School

Semmelweis University, Doctoral School of Pharmaceutical Sciences