Chronic mild restraint stress rats decreased CMKLR1 expression in distinct brain region

Inflammation contributes to the pathophysiology of depression. Chemokine-like receptor-1 (CMKLR1) plays an important role both in the development of inflammation and in the mechanism of antidepressant effect of Omega-3 polyunsaturated fatty acids (Omega-3 PUFAs), ecosapeatanolicacid (EPA). The present study was to investigate the modification of CMKLR1 in chronic restraint stress (CRS) rats. CMKLR1 was examined in different brain region from CRS rats by using western blot and quantitative real-time PCR. The CMKLR1 expression in the hippocampus, prefrontal cortex and cerebellum was determined on 3, 7, 10 and 21 days of repeated restraint stress and was compared to controls. The results showed that the protein and mRNA level of CMKLR1 in the prefrontal cortex and hippocampus were significantly increased on day 3 and then decreased on day 7, 10 and 21 in the CRS rats. The protein and mRNA level of CMKLR1 in cerebellum was similar to that of control group throughout the whole experiment. Changed expression of brain CMKLR1 is suggested to be involved in the mechanism of depression.

► CMKLR1 mRNA level in the PFC and hippocampus was markedly decreased in the CRS rats.
► The CMKLR1 protein level in the PFC and hippocampus decreased in the CRS rats.
► Decreased expression of CMKLR1 is suggested to be involved in depression.