and RANTES induce formation of TRAP-positive, multinuclear cells from M-CSF-treated monocytes in the absence of RANKL, but produced osteoclasts that lacked cathepsin K expression and resorptive capacity. It is proposed that CCL2 and RANTES act as autocrine loop in human osteoclast differentiation. The CCL2 chemokine is also expressed by neurons, astrocytes and microglia. The expression of CCL2 in neurons is mainly found in the cerebral cortex, globus pallidus, hippocampus, paraventricular and supraoptic hypothalamic nuclei, lateral hypothalamus, substantia nigra, facial nuclei, motor and spinal trigeminal nuclei, gigantocellular reticular nucleus and in Purkinje cells in the cerebellum. Clinical importance CCL2 is implicated in pathogeneses of several diseases characterized by monocytic infiltrates, such as psoriasis, rheumatoid arthritis and atherosclerosis. Administration of anti-CCL2 antibodies in a model of glomerulonephritis reduces infiltration of macrophages and T cells, reduces crescent formation, as well as scarring and renal impairment. CCL2 is involved in the neuroinflammatory processes that takes place in the various diseases of the central nervous system (CNS), which are characterized by neuronal degeneration. CCL2 expression in glial cells is increased in epilepsy, brain ischemia Alzheimer's disease experimental autoimmune encephalomyelitis (EAE), and traumatic brain injury. Hypomethylation of CpG sites within the CCL2 promoter region is affected by high levels of blood glucose and TG, which increase CCL2 levels in the blood serum. The later plays an important role in the vascular complications of type 2 diabetes. CCL2 induces amylin expression through ERK1/ERK2/JNK-AP1 and NF-κB related signaling pathways independent of CCR2. Amylin upregulation by CCL2 contributes to the elevation of the plasma amylin and insulin resistance in obesity. Adipocytes secrete various adipokines that may be involved in the negative cross-talk between adipose tissue and skeletal muscle. CCL2 impairs insulin signaling in skeletal muscle cells via ERK1/2 activation at doses similar to its physiological plasma concentrations (200 pg/mL), but does not involve activation of the NF-κB pathway. CCL2 significantly reduced insulin-stimulated glucose uptake in myocytes. CCL2 may represent a molecular link in the negative cross-talk between adipose tissue and skeletal muscle assigning a completely novel important role to CCL2 besides inflammation. Incubation of HL-1 cardiomyocytes and human myocytes with oxidized-LDL induced the expression of BNP and CCL2 genes, while native LDL (N-LDL) had no effect. Treatment with melatonin in old mice with age related liver inflammation decreased the mRNA expression of TNF-α, IL-1β, HO (HO-1 and HO-2), iNOS, CCL2, NF-κB1, NF-κB2 and NKAP in old male mice. The