MIF (Macrophage migration Inhibitory Factor) - a new molecular target for the treatment of depressant and anxiety...

Clinical depression affects 121 million people around the world,  according to the World Health Organization, but only 60% to 80% of cases are effectively treated with current medication and psychotherapy.  Now researchers from Ecole Polytechnique Fédérale de Lausann, (EPFL), have come up with an interesting target, i.e., macrophage migration inhibitory factor, MIF. 

MIF(see strucutre : wikipedia : a pro-inflammatory cytokine that is expressed in the CNS) is normally thought to play a role in tissue swelling (inflammatory mediator possibly associated with rheumatoid arthritis,  RA-severity) and even cancer development (metastatic potential in speculative models of cancer), but its precise location and function in the brain remained a mystery before Carmen Sandi's (lead researcher) study. 

 The research team, first detected a concentration of MIF protein in stem cells in the hippocampus, (a key area for memory formation and neuron generation during adulthood). New neurons are thought to be linked to the creation of new memories but they may also play an important role in curbing anxiety  (previous studies have shown that prolonged periods of stress reduce neurogenesis, and many anti-depressants actually boost the production of new neurons).

By genetically and pharmaceutically manipulating the level of MIF in the hippocampus of rats, the researchers discovered that the absence of MIF significantly reduced the production of neurons and increased anxiety They also found that the lack of MIF decreases the ability of anti-depressants to stimulate neurogenesis. 

Researchers, identified  MIF expression in neurogenic cells  (in stem cells, cells undergoing proliferation, and in newly proliferated cells undergoing maturation) in the subgranular zone of the rodent dentate gyrus. A causal function for MIF in cell proliferation was shown using genetic (MIF gene deletion) and pharmacological (treatment with the MIF antagonist Iso-1 - see (right side) chemical structure : (S,R)-3-(4-Hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid, methyl ester) approaches. 

As per the claim by the researchers,  genetic deletion of MIF resulted in increased anxiety and depression-like behaviors, as well as of impaired hippocampus-dependent memory. Researchers conclude that,   MIF as a potentially relevant molecular target for the development of treatments linked to deficits in neurogenesis, as well as to problems related to anxiety, depression, and cognition....

Ref : Carmen Sandi et. al., Molecular Psychiatry, 23 February 2010