Biomarkers in human platelets can be used to detect depression, according to researchers led by University of Illinois Chicago distinguished professor Mark Rasenick, who discovered a biomarker in human platelets.
An enzyme called adenylyl cyclose (AC), which is produced in response to neurotransmitters such as serotonin and adrenaline, has been found to play a role in the development of depression in both humans and animal models.
“Adenylyl cyclase levels are low in those who are depressed. For some reason, the enzyme that allows neurotransmitters to generate adenylyl cyclases is attenuated because the intermediary protein, Gs alpha, is locked in the cholesterol-rich membrane matrix of the lipid raft, where they do not work very effectively “Rasenick was quoted as saying.
The cellular biomarker for Gs alpha translocation from lipid rafts was discovered in a new study published in the journal Molecular Psychiatry, “A Novel Peripheral Biomarker for Depression and Antidepressant Response,”. One way to discover the biomarker is to perform a blood test.
As a researcher at the Jesse Brown VA Medical Center, Rasenick has developed a single biomarker test that can indicate both the presence of depression as well as the efficacy of treatment. “What we have developed is a test that can not only indicate the presence of depression but it can also indicate therapeutic response with a single biomarker, and that is something that has not existed to date,” Rasenick says.
According to the researchers, they may be able to perform this blood test as soon as one week after starting antidepressant therapy to determine if the treatment is effective. Patients’ depressive symptoms improved when Gs alpha was found outside the lipid raft, according to previous studies. There were no improvements in symptoms in patients who took antidepressants, yet Gs alpha remained trapped — showing that simply having antidepressants in the bloodstream was not enough to alleviate symptoms..
Whether or not Gs alpha is still in the lipid raft can be determined by a blood test after one week.
“In those who were going to get better, you would notice a change in their platelets because they turn over in one week. The biomarker that should indicate a successful treatment would be visible “It was Rasenick’s opinion.
It currently takes several weeks or months for patients and doctors to establish if antidepressants are functioning, and when it is determined that they are not working, various therapy are tried.
“Approximately 30 percent of people never recover from their depression. Perhaps doctors and patients assume that nothing will work, and thus leads to a cycle of failure “Rasenick made the comment. “Primary care doctors typically do not have access to advanced screening tools for diagnosing depression. With this test, doctors can say, “Gee, they look depressed, but their blood does not tell us they are,” even though their appearance suggests otherwise. Maybe we should rethink this?”
Rasenick hopes to create the screening test with the help of his company, Pax Neuroscience, after more research is completed.
