Gastrin attenuates ischemia-reperfusion-induced intestinal injury in rats.

Intestinal ischemia-reperfusion (I/R) injury is a devastating complication when the blood supply is reflowed in ischemic organs. Gastrin has critical function in regulating acid secretion, proliferation, and differentiation in the gastric mucosa. We aimed to determine whether gastrin has an effect on intestinal I/R damage. Intestinal I/R injury was induced by 60-min occlusion of the superior mesenteric artery followed by 60-min reperfusion, and the rats were induced to be hypergastrinemic by pretreated with omeprazole or directly injected with gastrin. Some hypergastrinemic rats were injected with cholecystokinin-2 (CCK-2) receptor antagonist prior to I/R operation. After the animal surgery, the intestine was collected for histological analysis. Isolated intestinal epithelial cells or crypts were harvested for RNA and protein analysis. CCK-2 receptor expression, intestinal mucosal damage, cell apoptosis, and apoptotic protein caspase-3 activity were measured. We found that high gastrin in serum significantly reduced intestinal hemorrhage, alleviated extensive epithelial disruption, decreased disintegration of lamina propria, downregulated myeloperoxidase activity, tumor necrosis factor-α, and caspase-3 activity, and lead to low mortality in response to I/R injury. On the contrary, CCK-2 receptor antagonist L365260 could markedly impair intestinal protection by gastrin on intestinal I/R. Severe edema of mucosal villi with severe intestinal crypt injury and numerous intestinal villi disintegrated were observed again in the hypergastrinemic rats with L365260. The survival in the hypergastrinemic rats after intestinal I/R injury was shortened by L365260. Finally, gastrin could remarkably upregulated intestinal CCK-2 receptor expression. Our data suggest that gastrin by omeprazole remarkably attenuated I/R induced intestinal injury by enhancing CCK-2 receptor expression and gastrin could be a potential mitigator for intestinal I/R damage in the clinical setting.

Human embryonic lung fibroblasts treated with artesunate exhibit reduced rates of proliferation and human cytomegalovirus infection in vitro.

BACKGROUND: Cytomegalovirus (CMV) pneumonia is a major cause of death in immunosuppressed patients. Despite the effective treatment with ganciclovir (GCV) and other antiviral agents, the mortality rate remains between 30% to 50%. Recently, the anti-malarial drug artesunate (ART) wasfound to exhibit significant anti-viral activity. Here, we examined the effects of ART on human cytomegalovirus (HCMV) infection and human embryonic lung fibroblast (HELF) proliferation in vitro. METHODS: HELFs infected with the GFP-expressing Towne-BAC strain of HCMV were divided into three treatment groups: Group I, cells treated with ART for 1.5 h before HCMV inoculation; Group II, cells infected with HCMV that was pre-treated with ART for 1.5 h before HCMV inoculation; Group III, cells that were treated with ART at 1.5 h post-HCMV inoculation. GFP expression was observed daily by fluorescence microscopy, and the number of GFP-positive cells in each experimental group was recorded at 4-5 days post-infection. At 10 days post-infection, the viability of cells in each group was recorded. GCV treatment was used as a control. RESULTS: While no significant effects on cytotoxicity, cell viability, viral infection rates, or antiviral activity were observed upon treatment of Group I or II cells with GCV or low levels of ART, the ART-treated Group III population exhibited significantly reduced rates of infection at drug concentrations higher than 12.5 µM. Similarly, we observed a GCV concentration-dependent reduction in the viral infection rate in Group III cells. Notably, ART-treated, but not GCV-treated, cells also exhibited decreased proliferation. The 50% cytostatic concentrations (CC50) and the half maximal inhibitory concentrations (IC50) of ART and GCV were 54.382 µM and 12.679 µM, and 3.76 M and 14.479 µM, respectively. CONCLUSIONS: In addition to its robust antiviral activity, ART inhibits proliferation of HCMV-infected lung fibroblasts, making it a potential next-generation drug for CMV pneumonia treatment and for reducing fibroproliferation and fibrosis in these patients.

[Drug susceptibility and UL97 gene mutation analysis of cytomegalovirus in recipients of hematopoietic stem cell transplantation].

OBJECTIVE: To monitor human cytomegalovirus (HCMV) drug resistance in recipients of hematopoietic stem cell transplantation by phenotypic and genotypic methods. METHODS: HCMV clinical isolates was isolated from the urine of hematopoietic stem cell transplantation recipients treated with GCV. Tissue cell infection median dose (TCID50) of the isolates was calculated using Reed-Muench method, and their drug susceptibility was determined by plaque reduction assay. We amplified the UL97 DNA fragment of the virus by nested PCR followed by automated DNA sequencing. RESULTS: HCMV clinical strain isolated from the urine samples of the recipients using a human fibroblast cell line showed a TCID50 value of 10(-4.618)/0.1 ml and a 50% inhibitory concentration (IC50) to GCV of 5.847 µmol/L, suggesting its sensitivity to GCV. Alignment with the AD169 DNA reference sequence identified 4 point mutations of the virus at 1509 (T-C), 1575 (C-T), 1794 (T-C), and 1815 (C-G), and only the last mutation resulted in one amino acid mutation to D605E. No gene mutation was found in relation to GCV resistance. CONCLUSIONS: Phenotypic and genotypic assays were established to examine antiviral drug resistance of HCMV in recipients of hematopoietic stem cell transplantation. We did not find any drug resistance of the clinical HCMV isolate.

Myelin-associated glycoprotein inhibits the neuronal differentiation of neural progenitors.

Nogo-66, myelin-associated glycoprotein (MAG), and oligodendrocyte myelin glycoprotein, possess axon growth-inhibiting properties by binding with the Nogo-66 receptor. Recent studies have shown that Nogo-66 inhibits neuronal differentiation of neural progenitor cells (NPCs) and the neurite outgrowth of the neurons differentiated from NPCs. However, the effects of MAG on the differentiation and proliferation of NPCs are unclear. We found that NPCs derived from the hippocampus of embryonic rats expressed Nogo-66 receptor and MAG-Fc, which mimics the function of MAG, inhibited the differentiation of NPCs into neurons but promoted differentiation of NPCs into astrocytes. Furthermore, MAG-Fc inhibited the neurite outgrowth of the neurons differentiated from NPCs. Our results suggest that MAG can inhibit the neuronal differentiation of NPCs.