Investigating the effects of molecular and environmental factors on collagen deposition by cultured rainbow trout (Oncorhynchus mykiss) cardiac fibroblasts

Abstract

Male rainbow trout undergo sex-specific cardiac remodelling in response to thermal acclimation, which includes changes in collagen composition. To characterize the cellular mechanisms involved we used cardiac fibroblasts from male and female trout to build upon previous studies on the collagen remodelling process. Rainbow trout cardiac fibroblasts were exposed to testosterone, cold acclimation, angiotensin II (ANG II), TGF-, and biomechanical stretch to look at their influences on cell signalling and gene transcription. We hypothesized that fibroblasts would respond to these factors in a pro-collagen response except for testosterone due to its inability to cause change in previous studies with other animals. increase We found that the factors did not act in a consistently pro-fibrotic manner. One notable finding was the induction of cell signalling under cold acclimated stretch. This provides support for the hypothesis that the increased ventricular stretch that occurs under cold acclimation initiates the collagen remodelling response.