The Energetic Stress Marker GDF15 is Induced by Acute Psychosocial Stress.

GDF15 (growth differentiation factor 15) is a marker of cellular and mitochondrial energetic stress linked to physical-mental illness, aging, and mortality. Here, we describe the psychobiological regulation of plasma and saliva GDF15 in four human studies including 3,599 samples from 148 healthy individuals. We report two main observations establishing GDF15 as a novel tractable biomarker of psychosocial stress.

Dynamic behavior of cell-free mitochondrial DNA in human saliva.

Mitochondria contain their own genome that can be released in multiple biofluids such as blood and cerebrospinal fluid, as cell-free mitochondrial DNA (cf-mtDNA). In clinical studies, blood cf-mtDNA predicts mortality and higher cf-mtDNA levels are associated with mental and physical stress. However, the dynamics of cf-mtDNA has not been defined, and whether it can be measured non-invasively like other neuroendocrine markers in saliva has not been examined.