Timur O. Yarovinsky

Genetic, hormonal, anatomical, and environmental factors underlie sex differences in the prevalence and progression of cardiovascular disease and responses to therapeutics. The presence of two X chromosomes in the female genome decreases susceptibility to X-linked recessive disorders but imposes the need for random X chromosome inactivation as an epigenetic mechanism controlling gene dosage. Long non-coding RNA XIST is essential for transcriptional repression of genes on inactive X chromosome but may also act as a miRNA sponge for post-transcriptional regulation of gene expression and a scaffold for RNA binding proteins that provoke autoimmune responses. These features draw attention to XIST as an important drug development target by design or as an off target, including novel RNA therapeutics for genetic and cardiovascular diseases. Based on the extensive literature analysis, we postulate the hypothesis that XIST can determine sex differences in cardiovascular drug responses and propose several criteria for use in developing or evaluating responses to RNA therapeutics for cardiovascular disease in women. We hope that implementation of those criteria in the process of RNA therapeutics development may be helpful in reducing the risks of adverse effects in women.

Many bacterial pathogens, includingStaphylococcus aureus, use a variety of pore-forming toxins as important virulence factors. Staphylococcal alpha-toxin, a prototype β-barrel pore-forming toxin, triggers the release of proinflammatory mediators and induces primarily necrotic death in susceptible cells. However, whether host factors released in response to staphylococcal infections may increase cell resistance to alpha-toxin is not known. Here we show that prior exposure to interferons (IFNs) prevents alpha-toxin-induced membrane permeabilization, the depletion of ATP, and cell death. Moreover, pretreatment with IFN-α decreases alpha-toxin-induced secretion of interleukin 1β (IL-1β). IFN-α, IFN-β, and IFN-γ specifically protect cells from alpha-toxin, whereas tumor necrosis factor alpha (TNF-α), IL-6, and IL-4 have no effects. Furthermore, we show that IFN-α-induced protection from alpha-toxin is not dependent on caspase-1 or mitogen-activated protein kinases, but requires protein synthesis and fatty acid synthase activity. Our results demonstrate that IFNs may increase cell resistance to staphylococcal alpha-toxin via the regulation of lipid metabolism and suggest that interferons play a protective role during staphylococcal infections.