[
Cell Metab,
2016]
Sex differences in longevity can provide insights into novel mechanisms of aging, yet they have been little studied. Surprisingly, sex-specific longevity patterns are best known in wild animals. Evolutionary hypotheses accounting for longevity patterns in natural populations include differential vulnerability to environmental hazards, differential intensity of sexual selection, and distinct patterns of parental care. Mechanistic hypotheses focus on hormones, asymmetric inheritance of sex chromosomes and mitochondria. Virtually all intensively studied species show conditional sex differences in longevity. Humans are the only species in which one sex is known to have a ubiquitous survival advantage. Paradoxically, although women live longer, they suffer greater morbidity particularly late in life. This mortality-morbidity paradox may be a consequence of greater connective tissue responsiveness to sex hormones in women. Human females' longevity advantage may result from hormonal influences on inflammatory and immunological responses, or greater resistance to oxidative damage; current support for these mechanisms is weak.
[
Annu Rev Biochem,
2008]
Phospholipases A(2) (PLA2s) are esterases that hydrolyze the sn-2 ester of glycerophospholipids and constitute one of the largest families of lipid hydrolyzing enzymes. The mammalian genome contains 10 enzymatically active secreted PLA2s (sPLA2s) and two sPLA2-related proteins devoid of lipolytic enzymatic activity. In addition to the well-established functions of one of these enzymes in digestion of dietary phospholipids and another in host defense against bacterial infections, accumulating evidence shows that some of these sPLA2s are involved in arachidonic acid release from cellular phospholipids for the biosynthesis of eicosanoids, especially during inflammation. More speculative results suggest the involvement of one or more sPLA2s in promoting atherosclerosis and cancer. In addition, the mammalian genome encodes several types of sPLA2-binding proteins, and mounting evidence shows that sPLA2s may have functions related to binding to cellular target proteins in a manner independent of their lipolytic enzymatic activity.