The purpose of this study was to evaluate the cerebral protection of salvianolic acid B (Sal B) against cerebral I/R injury and investigate the underlying mechanism. As shown by 2,3,5-Triphenyltetrazolium chloride (TTC) staining and magnetic resonance imaging (MRI) analyses, Sal B significantly reduced cerebral infarct size, and accompanied with improved neurobehavioral functions as indicated by the modified Bederson score and Longa five-point scale. Sal B decreased the production of reactive oxygen species (p < .05, n = 10). The data of Western blotting and reverse transcription quantitative real time polymerase chain reaction (qRT-PCR) analyses showed that the expression of GFAP, Iba1, IL-1β, IL-6, TNF-α and Cleaved-caspase 3 was significantly reduced by Sal B in I/R injured brain tissues as compared to corresponding controls (p < .05, n = 10). Over activation of astrocytes and microglia were inhibited by Sal B as shown by immunostaining of GFAP and Iba 1. These data suggest that Sal B has neural protective effects against I/R-induced cerebral injury and could be an effective candidate for further development of clinical therapy.
Abstract. Endothelin (ET)-2 plays a crucial role in ovarian ovulation in mammals. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1α-mediated transcriptional activation contributes to the increased expression of ET-2 gene in response to hCG in rat ovarian granulosa cells (GCs) during gonadotropin-induced superovulation. By realtime RT-PCR analysis, ET-2 mRNA expression was found to significantly increase in cultured ovarian GCs after treatment with hCG, or even N-carbobenzoxyl-L-leucinyl-L-leucinyl-L-norvalinal , while this increased ET-2 mRNA expression could also be blocked by ferrous ammonium sulfate (FAS) under human chorionic gonadotropin (hCG) treatment. Further analysis also found that these changes of ET-2 mRNA were consistent with HIF-1α expression or HIF-1 activity, and HIF-1α inhibitor echinomycin inhibited ovulation in rats. Taken together, these results indicate that ET-2 is transcriptionally activated by hCG through HIF-1α-mediated mechanism in GCs. This HIF-1α-induced transcriptional activation may be one of the important mechanisms mediating the increase of ET-2 expression in GCs during the gonadotropin-induced mammalian ovulatory process in vivo. Key words: Endothelin-2, Granulosa cells, Hypoxia-inducible factor-1α, Rat (J. Reprod. Dev. 58: [678][679][680][681][682][683][684] 2012) I n female rats, two pituitary gonadotropin hormones, FSH and LH, control reproductive cyclical events, including ovarian follicle maturation, rupture and release of fertilizable oocytes during a 4-day reproductive cycle in the initial stage of puberty. During each cycle, FSH stimulates a pool of preantral follicles to develop into mature follicles, while the ensuing surge of LH induces ovulation, through LH-activated downstream signaling pathways inthe preovulatory follicles and eventually triggers the release ofoocytes from these follicles [1,2]. At present, our understanding of the regulatory mechanisms controlling the growth and final differentiation of a mammalian follicle has advanced exponentially, but our understanding of even the most fundamental pathways is still not complete during these dynamic processes. Endothelin-2 (ET-2) was recently proposed as a granulosa cell-derived contractile signal that facilitates ovulation [3][4][5].Endothelin-2 (ET-2) is a small, 21 amino acid peptide that is produced by granulosa cells at the time of ovulation [3]. Expression of mRNA for ET-2, but not ET-1 or ET-3, is dramatically increased in the periovulatory follicle for only a very brief period of time (1-2 h) around ovulation, and blockade of endothelin receptor binding will delay/inhibit the process of follicular rupture [3]. This rather unique spatial-and temporal-specific pattern of mRNA expression suggests the involvement of direct signaling pathways to accurately coordinate controlled production of this peptide. Therefore, understanding of the regulatory mechanism controlling production of endothelin-2 (ET-2) becomes more and more important for further knowledge of the p...
Echinomycin is a small-molecule inhibitor of hypoxia-inducible factor-1 DNA-binding activity, which plays a crucial role in ovarian ovulation in mammalians. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1α-mediated endothelin (ET)-2 expressions contributed to ovarian ovulation in response to human chorionic gonadotropin (hCG) during gonadotropin-induced superuvulation. By real-time RT-PCR analysis, ET-2 mRNA level was found to significantly decrease in the ovaries after echinomycin treatment, while HIF-1α mRNA and protein expression was not obviously changed. Further analysis also showed that these changes of ET-2 mRNA were consistent with HIF-1 activity in the ovaires, which is similar with HIF-1α and ET-2 expression in the granulosa cells with gonadotropin and echinomycin treatments. The results of HIF-1α and ET-2 expression in the granulosa cells transfected with cis-element oligodeoxynucleotide (dsODN) under gonadotropin treatment further indicated HIF-1α directly mediated the transcriptional activation of ET-2 during gonadotropin-induced superuvulation. Taken together, these results demonstrated that HIF-1α-mediated ET-2 transcriptional activation is one of the important mechanisms regulating gonadotropin-induced mammalian ovulatory precess in vivo.
Head and neck squamous cell carcinoma (HNSCC) is a multistage process during which adverse genetic alterations accumulate resulting in loss of cell cycle control, selective cell overgrowth, and ultimately formation of malignancy. Among various genetic alterations in HNSCC is increased microsatellite instability (MSI). hMLH1 is one of the major mismatch DNA repair genes, the inactivation of which caused increased MSI in a variety of human cancers including HNSCC. While somatic mutation is a major mechanism of the hMLH1 gene inactivation in hereditary form of human cancer, promoter hypermethylation appears to be primarily involved in the inactivation of the hMLH1 gene in sporadic form of human cancers. In the current study, we analyzed 78 cases of HNSCC for hMLH1 protein expression and promoter hypermethylation by IHC and methylation-specific PCR (MSP). Twenty-four of 78 cases (31%) of HNSCC contained markedly reduced levels of the hMLH1 protein. Based on the IHC results, 8 cases without and 8 with hMLH1 protein expression (total of 16) were further analyzed by MSP. Seven of 8 cases (88%) that were negative for the hMLH1 protein displayed promoter hypermethylation, whereas 7 of 7 cases (100%) strongly positive for the protein were free of promoter methylation. This study confirms our previous conclusion that promoter hypermethylation represents a major mechanism of the hMLH1 gene inactivation in HNSCC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.