There were no significant MI-503 research buy differences among 0–24-hr hypoxia in control groups (n= 20) for all the measured cytokines. As shown in Table 1, 6-hr hypoxia evoked an obvious elevation of IL-17A (mean 7.10 pg/mL, n= 20), IL-1β (mean 37.00 pg/mL, n= 20) and IL-23 (mean 377.49 pg/mL, n= 20) from PBMC in
chronic stage SCI patient groups, while 24-hr hypoxia induced a slightly decreased release of IL-17A (mean 5.74 pg/mL, n= 20). On the contrary, no obvious elevation of IFN-γ (mean 11.81 pg/mL, n= 20) was detected in SCI patients’ PBMC culture supernatants under hypoxia exposure (Table 2). This study provides evidence that hypoxia might induce immunological response by upregulating Th17 ratio and IL-17A expression in severe RXDX-106 purchase cerebral infarction patients during the chronic stage. Previous studies have found increased peripheral blood IL-17A mRNA levels in acute cerebral infarction patients (7, 19). However, it was difficult to demonstrate in vivo whether the IL-17A upregulation was induced by hypoxia but not by
other potential stimuli. It has been demonstrated that hypoxia could upregulate the expression and function of pro-inflammatory cytokines and inhibitors of these cytokines might prevent related neurotoxicity in ischemic stroke rodent models (20–23). But to our knowledge, the hypoxia induced Th17 participating pathogenesis of brain ischemic injury has not been reported. The results of this study indicate that the primary event following hypoxia treatment of cultured patients’ PBMC involves Th17 upregulation, accompanied by increased IL-17A expression and release. Previous studies have demonstrated Th17 and IL-17A are essential for the expression of pro-inflammatory cytokines triggered by transcription factor nuclear factor-κB in multiple those sclerosis (24). Our data revealed that only the
patients but not healthy volunteers’ PBMC responded significantly higher to hypoxia exposure for IL-17A expression as well as Th17 upregulation in vitro, suggesting that local ischemic brain lesions might already contribute to PBMC differentiation toward Th17 direction during the acute stage in vivo and the activated PBMC obtained during the chronic stage of ischemic stroke might be more allergic to hypoxia stimulation compared to normal control groups. How do ischemic neural cells in the central nervous system (CNS) affect Th17 upregulation in vivo? Pro-inflammatory cytokines, such as TNF-α, IL-1β, IL-6, TGF-β and IL-23 produced in the CNS may enter the peripheral blood and upregulate Th17 in PBMC. Alternatively, peripheral blood T cells and monocytes/macrophages may enter the CNS by means of chemokines induced in the ischemic brain and be activated, and then return to the peripheral blood. Previous studies have revealed that activated monocytes/macrophages played an important pathogenic role in hypoxic and ischemic brains (25–27).