Title: The impact of mitochondrial and thermal stress on the bioengenerics and reserve capacity of fish cell lines Authors
Submitted to: International Congress on the Biology of Fish
Publication Type: Abstract Only
Publication Acceptance Date: May 13, 2012
Publication Date: July 17, 2012
Citation: Beck, B.H., Fuller, S.A. 2012. The impact of mitochondrial and thermal stress on the bioengenerics and reserve capacity of fish cell lines [abstract]. 10th International Congress on the Biology of Fish. p.9. Technical Abstract: Both wild and cultured fish are subject to numerous stressors that can induce or exacerbate metabolic disturbances that first manifest at the cellular level. In the present study, we sought to further our understanding of cellular metabolism in fish by examining the comparative responses of cell lines derived from three fish species: channel catfish (CCO), white bass (WBE), and fathead minnow (EPC) to both mitochondrial and thermal stressors. We extracellular flux (EF) technology, which detects minute changes in oxygen (O2) levels and pH within the media immediate to cells. By measuring the O2 consumption rate (OCR), an indicator of mitochondrial respiration, cells exhibited unique aerobic phenotypes. Simultaneously, we measured the extracellular acidification rate (ECAR), a surrogate of glycolysis, and found that amongst all cell lines the ECAR was <1 mpH/min/ g protein. Next, we performed a mitochondrial function protocol whereby compounds modulating distinct components of mitochondrial respiration were sequentially exposed to cell monolayers. This experiment provided us with basal and maximal OCR, OCR linked to ATP production, OCR resulting from ion movement across the mitochondrial inner membrane, the reserve respiratory capacity, and OCR independent of the electron transport chain. From these parameters we constructed metabolic signatures for each cell type. Following a heat shock, EPC and CCO cells significantly decreased aerobic respiration and all three cell lines modestly increased glycolytic metabolism. After heat shock, the reserve capacity was relatively unaffected in EPC and CCO cells, but significantly decreased in WBE cells; suggesting a diminished capacity of WBE cells to cope with thermal stress These novel findings provide key proof-of-concept experimental data that further highlight the utility of fish cells/cell lines as tools for modeling bioenergetics and will facilitate the development of assays predictive of how fish cope with insults encountered in various settings.