Abnormal expression of colony stimulating factor 1 receptor (CSF1R) and transcription factor PU.1 (SPI1) in the spleen from patients with major psychiatric disorders: A role of brain-spleen axis.

BACKGROUND

The colony stimulating factor 1 receptor (CSF1R) regulates microglia/macrophage proliferation, differentiation and survival; however, the precise role of this protein in psychiatric disorders is unknown. CSF1R is also known to interact with the transcription factor PU.1 (SPI1). Here we studied whether the expressions of CSF1R and SPI1 are altered in the postmortem samples (parietal cortex, cerebellum, spleen) from patients with major psychiatric disorders.

METHODS

Protein expression of CSF1R and SPI1 in the parietal cortex, cerebellum and spleen from control, major depressive disorder (MDD), schizophrenia (SZ), and bipolar disorder (BD) groups was measured.

RESULTS

Levels of CSF1R in the spleen, but not cerebellum and parietal cortex, from MDD and SZ groups were significantly lower than the control group. There was a positive correlation between CSF1R levels in the spleen and CSF1R levels in the parietal cortex in the all subjects from four groups. Furthermore, levels of SPI1 in the cerebellum and spleen from MDD and SZ groups were significantly higher than the control group. Levels of SPI1 in the parietal cortex were not different among the four groups. Interestingly, there was a negative correlation between CSF1R and SPI1 levels in the spleen of the all subjects from four groups. There was also a negative correlation between CSF1R and SPI1 levels in the spleen of MDD group.

LIMITATIONS

The small number in each group may limit our interpretation.

CONCLUSIONS

Abnormalities in CSF1R and SPI1 in the brain-spleen axis might, in part, play a role in the pathophysiology of MDD.