A newly identified biomarker in human hair appears to be related to a type of schizophrenia. In addition to providing new information about the condition , the discovery could help identify it early, before symptoms arise.
It was a group of Japanese researchers, belonging to the RIKEN Center for Brain Science, who detected, in people with schizophrenia, higher than normal levels of Mpst, an enzyme responsible for the production of hydrogen sulfide in the brain. As they hypothesize in the article published in the scientific journal Embo Molecular Medicine, this abnormality is probably the result of a physiological reaction to certain stressors during the course of life, which leads to modification of the DNA.
Schizophrenia is a complex mental disorder, which includes a range of symptoms and behaviors, including hallucinations and psychosis; research suggests that it is not just one disease but as many as eight disorders with genetically distinct causes and the genetic risk factor is believed to be a major contributor to its development.
One method currently used to diagnose schizophrenia is called PPI (Prepulse inhibition) and consists of examining a person’s response to stimuli, manifested by a contraction of skeletal and facial muscles, generally classified as a defensive reaction. People who do not have schizophrenia are less likely to be startled by a loud noise if they have heard it before, while those with the condition react as if it were the first time.
In an animal model study, researchers found that the enzyme Mpst has higher expression when PPI is low; reducing the level of Mpst also helped bring PPI back to values closer to normal.
The Japanese team then examined the postmortem brains of people with schizophrenia and found that Mpst gene expression was higher than those without. In addition, Mpst levels were found to correlate with the severity of symptoms the person had experienced during his or her lifetime.
With this information, the researchers then examined the hair follicles of more than 150 people with schizophrenia and found that, even in these tissues, Mpst expression was much higher in people with the disease. Although Mpst levels are not found to be representative of all existing types of schizophrenia, their measurement could serve in many cases as a biomarker for schizophrenia before symptoms appear.
Source:
Ide M, Ohnishi T et al. Excess hydrogen sulfide and polysulfides production underlies a schizophrenia pathophysiology. EMBO Mol Med. 2019 Oct 28:e10695.
