Transcriptional response of Saccharomyces cerevisiae to the proapoptotic unsaturated fatty aldehyde t-2-hexadecenal by RNAseq
Hexadecenal, a trans (-2,3-) unsaturated fatty aldehyde, is an intermediate of the sphingolipid degradation pathway. This pathway, induced during cellular stress, involves the conversion of sphingosine-1-phosphate to hexadecenal by Sphingosine-1-Phosphate-Lyase (SPL) in humans and DPL1 in yeast. Hexadecenal is further metabolized to hexadecenoic acid by Fatty Aldehyde Dehydrogenase (ALDH3A2 in humans and HFD1 in yeast).  Trans-2-hexadecenal (t-2-hex), has been found to induce mitochondrial dysfunction in a conserved manner from yeast to humans. However, the specific mechanisms and biological targets underlying this lipid-induced mitochondrial inhibition remain largely unknown. In this study, we employed unbiased transcriptomic approaches using the Saccharomyces cerevisiae yeast model to elucidate the principal mechanisms and biological targets associated with t-2-hex-induced mitochondrial dysfunction.  To investigate the effects of t-2-hex, we utilized an hfd1 mutant strain lacking the HFD1 gene. This strain exhibited increased sensitivity to t-2-hex treatment compared to wild-type cells. Exponentially growing hfd1 mutant cells were exposed to 100 µM t-2-hex for a duration of 3 hours, while control cells were incubated with the solvent dimethyl sulfoxide (DMSO), in which hexadecenal is dissolved.  Total RNA was extracted from both treated and control cells for high-throughput sequencing analysis. Through transcriptomic profiling, we aimed to identify differentially expressed genes, pathways, and regulatory networks associated with t-2-hex-induced mitochondrial dysfunction in yeast. This study provides a comprehensive analysis of the transcriptional response to t-2-hex treatment, shedding light on the molecular mechanisms and potential biological targets underlying lipid-induced mitochondrial dysfunction.