Tedizolid phosphate alleviates DSS-induced ulcerative colitis by inhibiting senescence of cell and colon tissue through activating AMPK signaling pathway.

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease. Previous studies have suggested a link between senescence process and the body's inflammatory reaction, indicating that senescence may exacerbate UC, yet the relation between UC and senescence remains unclear. Tedizolid Phosphate (TED), a novel oxazolidinone antimicrobial, is indicated in acute bacterial skin infections, its impact on senescence is not known. Our research revealed that the UC inducer dextran sulfate sodium (DSS) triggers senescence in both colon epithelial NCM460 cells and colon tissues, and TED that screened from a compound library demonstrated a strong anti-senescence effect on DSS treated NCM460 cells. As an anti-senescence medication identified in this research, TED efficiently alleviated UC and colonic senescence in mice caused by DSS. By proteomic analysis and experimental validation, we found that DSS significantly inhibits the AMPK signaling pathway, while TED counteracts senescence by restoring AMPK activity. This research verified that the development of UC is accompanied with colon tissue senescence, and TED, an anti-senescence medication, can effectively treat UC caused by DSS and alleviate colon senescence. Our work suggests anti-senescence strategy is an effective approach for UC treatment.

Neuroprotective effects of genistein on SH-SY5Y cells overexpressing A53T mutant α-synuclein.

Genistein, a potent antioxidant compound, protects dopaminergic neurons in a mouse model of Parkinson's disease. However, the mechanism underlying this action remains unknown. This study investigated human SH-SY5Y cells overexpressing the A53T mutant of α-synuclein. Four groups of cells were assayed: a control group (without any treatment), a genistein group (incubated with 20 µM genistein), a rotenone group (treated with 50 µM rotenone), and a rotenone + genistein group (incubated with 20 µM genistein and then treated with 50 µM rotenone). A lactate dehydrogenase release test confirmed the protective effect of genistein, and genistein remarkably reversed mitochondrial oxidative injury caused by rotenone. Western blot assays showed that BCL-2 and Beclin 1 levels were markedly higher in the genistein group than in the rotenone group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling revealed that genistein inhibited rotenone-induced apoptosis in SH-SY5Y cells. Compared with the control group, the expression of NFE2L2 and HMOX1 was significantly increased in the genistein + rotenone group. However, after treatment with estrogen receptor and NFE2L2 channel blockers (ICI-182780 and ML385, respectively), genistein could not elevate NFE2L2 and HMOX1 expression. ICI-182780 effectively prevented genistein-mediated phosphorylation of NFE2L2 and remarkably suppressed phosphorylation of AKT, a protein downstream of the estrogen receptor. These findings confirm that genistein has neuroprotective effects in a cell model of Parkinson's disease. Genistein can reduce oxidative stress damage and cell apoptosis by activating estrogen receptors and NFE2L2 channels.

Exendin-4 inhibits high-altitude cerebral edema by protecting against neurobiological dysfunction.

The anti-inflammatory and antioxidant effects of exendin-4 (Ex-4) have been reported previously. However, whether (Ex-4) has anti-inflammatory and antioxidant effects on high-altitude cerebral edema (HACE) remains poorly understood. In this study, two rat models of HACE were established by placing rats in a hypoxic environment with a simulated altitude of either 6000- or 7000-m above sea level (MASL) for 72 hours. An altitude of 7000 MASL with 72-hours of hypoxia was found to be the optimized experimental paradigm for establishing HACE models. Then, in rats where a model of HACE was established by introducing them to a 7000 MASL environment with 72-hours of hypoxia treatment, 2, 10 and, 100 µg of Ex-4 was intraperitoneally administrated. The open field test and tail suspension test were used to test animal behavior. Routine methods were used to detect change in inflammatory cells. Hematoxylin-eosin staining was performed to determine pathological changes to brain tissue. Wet/dry weight ratios were used to measure brain water content. Evans blue leakage was used to determine blood-brain barrier integrity. Enzyme-linked immunosorbent assay (ELISA) was performed to measure markers of inflammation and oxidative stress including superoxide dismutase, glutathione, and malonaldehyde values, as well as interleukin-6, tumor necrosis factor-alpha, cyclic adenosine monophosphate levels in the brain tissue. Western blot analysis was performed to determine the levels of occludin, ZO-1, SOCS-3, vascular endothelial growth factor, EPAC1, nuclear factor-kappa B, and aquaporin-4. Our results demonstrate that Ex-4 preconditioning decreased brain water content, inhibited inflammation and oxidative stress, alleviated brain tissue injury, maintain blood-brain barrier integrity, and effectively improved motor function in rat models of HACE. These findings suggest that Ex-4 exhibits therapeutic potential in the treatment of HACE.

A meta-analysis of carotid endarterectomy versus stenting in the treatment of symptomatic carotid stenosis.

BACKGROUND: Carotid stenosis is one of the common reasons for patients with ischemic stroke, and the two invasive options carotid endarterectomy (CEA) and carotid artery stenting (CAS) are the most popular treatments. But the relative efficacy and safety of the methods are not clear. METHODS: About 521 articles related to CAS and CEA for carotid stenosis published in 1995 - 2011 were retrieved from MEDLINE, Cochrane Library (CL), and China National Knowledge Infrastructure (CNKI) China Journal Full-Test database. Of them, eight articles were chosen. Meta-analysis was used to assess the relative risks. RESULTS: The eight studies included 3873 patients with symptomatic carotid artery stenosis, including 1941 cases in the carotid stent angioplasty group, and 1932 cases in the carotid endarterectomy group. Fixed effect model analysis showed that within 30 days of incidence of all types of strokes, surgery was significantly highly preferred in CAS patients (CAS group) than the CEA patients (CEA group), and the difference was statistically significant (relative ratio (RR) = 1.80, 95% confidence interval (CI): 1.380 - 2.401, P < 0.0001). But the incidence of death in the two groups is not showed and is not statistically significant after 30 days (RR = 1.52, 95%CI: 0.82 - 2.82, P = 0.18). The rate of cranial nerve injury in the CAS group is lower than the CEA group (RR = 0.14, 95%CI: 0.05 - 0.43, P = 0.0005). The incidence of CAS patients with myocardial infarction is lower than the CEA group after 30 days, but statistically meaningless (RR = 0.22, 95%CI: 0.05 - 1.02, P = 0.05). The stroke or death in CAS patients were higher than the CEA group after 1 year of treatment (RR = 2.58, 95%CI: 1.03 - 6.48, P = 0.04). CONCLUSIONS: Compared to CAS, carotid endarterectomy is still the preferred treatment methodology of symptomatic carotid artery stenosis. Future meta-analyses should then be performed in long-term follow-up to support this treatment recommendation.

[Inhibitory effect of folic acid/polyamide-amine as a miR-7 vector on the growth of glioma in mice].

OBJECTIVE: To explore if folic acid/polyamide-amine (FA/PAMAM) enhances the therapeutic effect of miR-7gene therapy for glioma in vivo. METHODS: The miR-7 gene was transfected into U251 glioma cells by FA/PAMAM. The efficiency of gene transfection was assessed by fluorescence microscopy. The miR-7 level was detect by quantitative RT-PCR. Intracranial glioma models were established in thymectomized mice, and FA/PAMAM nanoparticles were transplanted into the tumors in situ 3 days later. The animal survival was recorded and the gross tumor volume and degree of edema were observed by MRI. Apoptosis in the glioma cells and expression of proliferating cell nuclear antigen (PCNA), matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) were assessed by immunohistochemistry, and EGFR and AKT-2 protein expression was detected by Western blot assay. RESULTS: Compared with the liposomes, the FA/PAMAM nanoparticles were more efficient to transfer miR-7 gene into U251 glioma cells, MRI showed that the tumor growth was much slower in the FA/PAMAM/miR-7 group, and the animal survival time was longer. The apoptosis rate was (5.3 ± 0.9)% in the control group, (11.4 ± 2.4)% in the liposome/miR-7 group, and (17.7 ± 3.7)% in the FA/PAMAM/miR-7 group. The immunohistochemical assay showed that the levels of PCNA, MMP-2 and MMP-9 protein in the FA/PAMAM/miR-7 group were (34.6 ± 5.4)%, (24.5 ± 4.1)%, (25.4 ± 5.1)%, respectively, significantly lower than those in the liposome/miR-7 group (49.3 ± 5.9)%, (31.7 ± 7.1)% and (39.4 ± 6.4)%, respectively, and those in the control group (57.3 ± 7.4)%, (45.4 ± 6.9)% and (55.1 ± 7.3)%, respectively (all P < 0.05). The expressions of EGFR and AKT-2 proteins were 1.09 ± 0.12 and 0.62 ± 0.10 in the control group, 0.63 ± 0.11 and 0.43 ± 0.07 in the liposome/miR-7 group, and significantly deceased (0.47 ± 0.09 and 0.31 ± 0.04, respectively) in the FA/PAMAM/miR-7 group (all P < 0.05). CONCLUSION: Compared with the liposomes, FA/PAMAM can transfect miR-7 into glioma cells with a higher efficiency in vivo, makes a longer time of the drug action, and shows a certain inhibitory effect on the growth of glioma, therefore, might become a new drug targeting agent in gene therapy forglioma.

[Ion chromatography for determination of ammonia sampled by silica gel in air of workplace].

OBJECTIVE: To establish an ion chromatography (IC) method for determination of ammonia in air of workplace. METHODS: Ammonia in workplace air was collected in silica gel tube, desorbed with 10 mmol/L methanesulfonic acid by ultrasonic for 10 min, determined by IC. RESULTS: The linearity range was 0.02-1.00 microg/ml. The linear equation was Y = 12041X-187 (r = 0.9997). The limit of quantification was 0.13 mg/m3 (the air volume was 1.5 L). Collection efficiency was 100%. Extraction efficiency was 99%. The relative standard deviation was 4.2%-6.3%. The penetration capacity was more than 264 microg. Sample could be stored for 14 days at least by ambient storage. CONCLUSION: This method is convenient, applicable and sensitive, suitable to determinate ammonia in air of workplace.

Tropism mechanism of stem cells targeting injured brain tissues by stromal cell-derived factor-1.

OBJECTIVE: To explore the role and function of stromal cell-derived factor-1 (SDF-1) in stem cells migrating into injured brain area. METHODS: Rat-derived nerve stem cells (NSCs) were isolated and cultured routinely. Transwell system was used to observe the migration ability of NSCs into injured nerve cells. Immunocytochemistry was used to explore the expression of chemotactic factor receptor-4 (CXCR-4) in NSCs. In vivo, we applied immunofluorescence technique to observe the migration of NSCs into injured brain area. Immunofluorescence technique and Western blotting were used to test expression level of SDF-1. After AMD3100 (a special chemical blocker) blocking CXCR-4, the migration ability of NSCs was tested in vivo and in vitro, respectively. RESULTS: NSCs displayed specific tropism for injured nerve cells or traumatic brain area in vivo and in vitro. The expression level of SDF-1 in traumatic brain area increased remarkably and the expression level of CXCR-4 in the NSCs increased simultaneously. After AMD3100 blocking the expression of CXCR-4, the migration ability of NSCs decreased significantly both in vivo and in vitro. CONCLUSIONS: SDF-1 may play a key role in stem cells migrating into injured brain area through specially combining with CXCR-4.

Stem cells modified by brain-derived neurotrophic factor to promote stem cells differentiation into neurons and enhance neuromotor function after brain injury.

OBJECTIVE: To promote stem cells differentiation into neurons and enhance neuromotor function after brain injury through brain-derived neurotrophic factor (BDNF) induction. METHODS: Recombinant adenovirus vector was applied to the transfection of BDNF into human-derived umbilical cord mesenchymal stem cells (UCMSCs). Enzyme linked immunosorbent assay (ELISA) was used to determine the secretion phase of BDNF. The brain injury model of athymic mice induced by hydraulic pressure percussion was established for transplantation of stem cells into the edge of injury site. Nerve function scores were obtained, and the expression level of transfected and non-transfected BDNF, proportion of neuron specific enolase (NSE) and glial fibrillary acidic protein (GFAP), and the number of apoptosis cells were compared respectively. RESULTS: The BDNF expression achieved its stabilization at a high level 72 hours after gene transfection. The mouse obtained a better score of nerve function, and the proportion of the NSE-positive cells increased significantly (P<0.05), but GFAP-positive cells decreased in BDNF-UCMSCs group compared with the other two groups (P<0.05). At the site of high expression of BDNF, the number of apoptosis cells decreased markedly. CONCLUSION: BDNF gene can promote the differentiation of the stem cells into neurons rather than glial cells, and enhance neuromotor function after brain injury.