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UNIVERSITY OF ILLINOIS AT CHICAGO
Department of Psychiatry
Fifth Annual Research Forum – Extravaganza 2014
POSTER TITLE
Increased Toll-like receptor 2 and 6 protein expression the
depressed suicide brain
DISEASE/KEY
WORDS:
TLR2, TLR5, TLR6, depression, suicide, postmortem brain
AUTHORS:
Xinguo Ren, M.D., Hooriyah S. Rizavi, M.S., Ghanshyam N.
Pandey, Ph. D
MENTEE
CATEGORY:
RESEARCH MENTOR:
Ghanshyam N.
Pandey, Ph. D.
BACKGROUND:
Abnormalities of the immune function in depression and suicide are
based in part on the observation of increased levels of proinflammatory
cytokines in the serum and in postmortem brain of depressed and
suicidal patients. Several studies suggest dysregulation of the immune
system in suicide as increased microgliosis has been reported in
postmortem brain of suicide subjects and increased levels of
proinflammatory cytokines in the CSF of suicidal patients. This
observed abnormality of cytokines in suicide may be related to altered
innate immune receptors known as Toll-like receptors (TLRs). In a
recent study we reported a significant increase in the protein and mRNA
levels of TLR3 and TLR4. To further examine the role of TLR in suicide
we have now studied the expression of TLR2, TLR5, and TLR6 in
depressed suicide subjects.
METHODS:
We determined the protein expression of TLR2, TLR5, and TLR6 in
the PFC of 24 depressed suicide victim and 24 normal control subjects.
The postmortem brain tissues were obtained from the Maryland Brain
Collection and the psychological autopsies were performed for the
diagnosis of the subjects using DSM-IV-SCID. Protein expression was
determined using Western blot technique.
RESULTS:
When we compared the protein expression of TLR2, TLR5 and
TLR6 of adult suicide brain with the normal control subjects, we found
UNIVERSITY OF ILLINOIS AT CHICAGO
Department of Psychiatry
that the protein expression of TLR2 was significantly increased in
depressed suicide victims compared with normal control subjects, while
there was no difference in TLR5 protein expression in depressed
suicide victims compared with normal control subjects. The protein
expression of TLR6 was also significantly increased in the PFC of
depressed suicide subjects compared with normal controls.
CONCLUSIONS:
These results suggest that overexpression of TLR2 and TLR6
protein may be in part related to the abnormalities of proinflammatory
cytokines in the brain of suicide victims and that abnormalities of innate
immunity are associated with suicide.