Anti-ALOX15 monoclonal antibody, clone 4H9

We studied the effect of SIRT1 deacetylase and PPAR gamma receptor activators on proinflammatory (M1), anti-inflammatory (M2) polarization of RAW264.7 macrophages and their modulating effects on insulin sensitivity of adipocytes. In M1 macrophages, the expression of TNF alpha and CXCL9, secretion of CXCL11, ROS generation, and content of dendritic-like cells were elevated. In M2 macrophages, expression of IGF-1 and ALOX15 factors was enhanced. SIRT1 activator (DCHC) and PPAR gamma receptor ligand (rosiglitazone) reduced expression of inflammatory markers TNF alpha and CXCL9 and increased expression of IGF-1 and ALOX15. SIRT1 inhibitor Ex527 increased the proportion of dendritic cells in macrophage populations. The paracrine effect of M1-macrophage-conditioned media attenuated insulin-dependent phosphorylation of threonine (Thr308) in Akt kinase and enhanced phosphorylation of serine (Ser473). This effect was attenuated by DCHC and rosiglitazone.

The pathogenesis of preeclampsia (PE) involves several pathophysiological processes that may be affected by glucocorticoid (GC). We confirmed previously that GC exposure could result in PE, while PE is linked to a deficiency of lipoxin A(4)(LXA(4)), an endogenous dual anti-inflammatory and proresolving mediator. The present study was to investigate whether GC exposure induces PEviadampening LXA(4). In the study, cortisol levels of PE women were higher than those of normal pregnancies, LXA(4)levels were downregulated in both PE patients and GC-mediated PE rats, and leukotriene B-4(LTB4) levels were upregulated in both PE patients and GC- mediated PE rats. Moreover, cortisol levels were negatively correlated to LXA(4)levels, while positively correlated to LTB(4)levels in PE patients. Mechanically, GC downregulated LXA(4)viadisturbing its biosynthetic enzymes, including ALOX15, ALOX5B and ALOX5, especially activating ALOX5, the key enzyme for class switching between LXA(4)and LTB4. Importantly, replenishing LXA(4)could ameliorate PE-related symptoms and placental oxidative stress in PE rat model induced by GC. Moreover, LXA(4)could inhibit GC-mediated ALOX5 activation and LTB(4)increase, and also suppress 11 beta-HSD2 expression and corticosterone upregulation. The protective actions of LXA(4)might be explained by its roles in antagonizing the adverse effects of GC on trophoblast development. Together, our findings indicate that GC exposure could contribute to PE through dampening LXA(4), and GC/LXA(4)axis may represent a common pathway through which PE occurs.