These results suggest that fluoxetine may have a direct bearing on the improvement of major depression. Further studies will begin to address these issues. The authors have declared that no competing interests exist. This study is supported by grants 81025025, 81001671 and 81373788 from the National Natural Science Foundation of China. “
“Amyloid-β (Aβ)-peptides, the primary components of neuritic plaques

found in brains of Alzheimer’s disease (AD), are generated by the proteolytic processing of the β-amyloid precursor protein (APP) (Selkoe, 2011 and De Strooper et al., 2012). Beneath the β- and γ-secretases, several other proteases, such as meprin-β, caspase and aminopeptidase A, seem to be involved in this process (Takeda et al., 2004, Sevalle et al., AZD1208 2009 and Bien et al., 2012). Thereby more than 40 different N- and C-terminally truncated and modified variants of the Aβ-peptides are generated (Maler et al., 2007). APP is also present in the immune cells of the central nervous system (CNS) and the periphery, particularly microglia and monocytes (Ledoux, 1993, Bitting et al., 1996, Jung et al., 1999 and Spitzer et al., 2010). The induction of APP and Aβ-peptide secretion in activated mononuclear phagocytes suggests

a role for APP in the initiation of immune responses (Monning et al., 1990 and Sondag and Combs, 2004). Both, the expression of surface receptors and cytokine secretion by macrophages and microglia are context sensitive. Thus, proinflammatory M1- and anti-inflammatory M2-polarized mononuclear phagocytes INCB024360 molecular weight represent the extremes of a heterogeneous continuum (Mantovani et al., 2004 and Varnum

and Ikezu, 2012). Although helpful as a model for investigating the basic functions of mononuclear phagocytes, recent research has identified several intermediate stages and cells that express M1 and M2 markers simultaneously (Xue et al., 2014). In brain sections from AD patients, microglia predominately presented markers of M1 polarization (Michelucci et al., 2009, Varnum and Ikezu, 2012 and Sudduth et al., 2013). The Alanine-glyoxylate transaminase proinflammatory polarization of microglia was shown to inhibit the clearance of Aβ-peptides and might therefore favor the accumulation of Aβ-peptides and consequent neuronal cell death, finally leading to cognitive deterioration and behavioral disturbances (Yamamoto, 2008). Several studies have investigated the phagocytosis of Aβ-peptides as a means to eliminate them from the organism, but data on a potential physiological role for Aβ-peptides in the process of phagocytosis are scarce. Reduced levels of Aβ-peptides in CSF are found not only in AD but also in several other neuroinflammatory diseases, such as borreliosis, herpes encephalitis and bacterial meningitis, with normalization after successful treatment (Sjogren et al., 2001 and Krut et al., 2013).