[The Effect of γ-secretase Inhibitor Combined with BMSC on the aGVHD in Mice Model].

OBJECTIVE: To establish the aGVHD mouse model，and investigate the regulatory effect and its mechanism of low-dose GSI combined with BMSC on aGVHD mice. METHODS: C57BL/6 (H-2b) and BALB/c (H-2d) were selected as donor and recipient of allogeneic transplantation to establish the aGVHD mouse model. BALB/c mice were randomly divided into 6 groups, which were the bone marrow cell infusion after irradiation (BM) group; the bone marrow cells + spleen cells after irradiation (BM+SC) group; the bone marrow cells + spleen cells + DMSO (BM+SC+DMSO) (transplant control) group; bone marrow cells + splenocytes +GSI after irradiation (BM+SC+GSI) group; bone marrow cells + spleen cells + bone marrow mesenchymal stromal infusion after irradiation cell (BM+SC+BMSC) group; bone marrow cells + spleen cells + bone marrow mesenchymal stromal cells +GSI infused after irradiation (BM+SC+BMSC+GSI) group. The mice in the two groups containing GSI were intraperitoneally injected with GSI at 5 µmol/kg on day 1, 2, and 3 after transplantation with DMSO as a control. The general conditions, survival time and hematopoietic recovery of mice were observed, cytokines were detected by ELISA, and histopathological changes were detected by immunohistochemistry. The effects of low-dose GSI combined with BMSC on hematopoietic reconstruction and aGVHD development after allo-BMT were investigated. RESULTS: The survival rate of the mice in BM+SC+BMSC+GSI combination group was 80% during the observation period, which was significantly higher than that in the other groups; the incidence of aGVHD was reduced in the BMSC GSI or their combination groups after 21 days of transplantation. GSI could partly promote the recovery of leukocytes, and show no significant delayed effect on the recovery platelets. Moreover, the level of Th1 cytokines (IFN-γ) in BM+SC+BMSC+GSI combined group was lower than that in BM+SC+GSI group (P<0.01), the level of Th2 cytokines (IL-4) in the combination group was higher than that in BM+SC+GSI group (P<0.01), also the level of IL-17 was significantly lower than that in the corresponding control group (P<0.001). CONCLUSION: Low dose GSI combined with BMSC can promote hematopoietic reconstruction and regulate cytokines secretion including IFN-γ, IL-4 and IL-17. GSI combined with BMSC achieve the goal of synergistically inhibiting the occurrence and progression of aGVHD.

A11, a novel diaryl acylhydrazone derivative, exerts neuroprotection against ischemic injury in vitro and in vivo.

There is an urgent need to develop effective therapies for ischemic stroke, but the complicated pathological processes after ischemia make doing so difficult. In the current study, we identified a novel diaryl acylhydrazone derivative, A11, which has multiple neuroprotective properties in ischemic stroke models. First, A11 was demonstrated to induce neuroprotection against ischemic injury in a dose-dependent manner (from 0.3 to 3 µM) in three in vitro experimental ischemic stroke models: oxygen glucose deprivation (OGD), hydrogen peroxide, and glutamate-stimulated neuronal cell injury models. Moreover, A11 was able to potently alleviate three critical pathological changes, apoptosis, oxidative stress, and mitochondrial dysfunction, following ischemic insult in neuronal cells. Further analysis revealed that A11 upregulated the phosphorylation levels of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) in OGD-exposed neuronal cells, suggesting joint activation of the phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MEK)/ERK pathways. In rats with middle cerebral artery occlusion, single-dose administration of A11 (3 mg/kg per day, i.v.) at the onset of reperfusion significantly reduced the infarct volumes and ameliorated neurological deficits. Our study, for the first time, reports the anti-ischemic effect of diaryl acylhydrazone chemical entities, especially A11, which acts on multiple ischemia-associated pathological processes. Our results may provide new clues for the development of an effective therapeutic agent for ischemic stroke.

[Research Progress on Notch Signal Pathway in Acute Graft-Versus-Host Disease -Review].

The Notch signaling pathway is a highly conserved cell signaling system that plays an essential role in many biological processes. Notch signaling regulates multiple aspects of hematopoiesis, especially during T cell develop-ment. Recent data suggest that Notch also regulates mature T cell differentiation and function. The latest data show that Notch also plays an essential role in alloreactive T cells mediating acute graft-versus-host disease (aGVHD), the most severe complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Notch inhibition in donor-derived T cells or blockade of individual Notch ligands and receptors after transplantation can reduce GVHD severity and mortality in mouse models of allo-HSCT, without causing global immunosuppression. These findings indicate Notch in T cells as an attractive therapeutic target to control aGVHD. In this article, the pathophysiology of aGVHD, the Notch signal pathway and aGVHD are reviewed.