CCL2 and obesity due to melanocortin 4 receptor deficiency: Since inflammation in the CNS is associated with disruption of the BBB in several neurological disorders, including some associated with obesity [44,45], we further analyzed the integrity of the BBB in the striatum by measuring the expression of key tight-junction proteins and the C-C chemokine ligand 2 (Ccl2), a regulator of BBB permeability.