Protective effects of imperatorin against cerebral ischemia/reperfusion-induced oxidative stress through Nrf2 signaling pathway in rats

OBJECTIVE To investigates the effects of imperatorin on the oxidative stress in the cerebral cortex and hippocampus after focal cerebral ischemia/reperfusion injury.METHODS Transient focal cerebral ischemia/reperfusion model in male Sprague-Dawley rats was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion.Imperatorin(1.25 and 2.5 mg·kg-1)or vehicle were administered intraperitoneally at 1,5 and 9 h after the onset of ischemia.At 24 h after reperfusion,the biomarkers of oxidative stress such as the levels of reactive oxygen species(ROS),lipid peroxidation products malondialdehyde(MDA),nitric oxide(NO)and total antioxidant capacity(T-AOC),the activities of inducible nitric oxide synthase(iN OS),superoxide dismutase(SOD)and catalase(CAT)in the cerebral cortex and hippocampus were observed.We also assessed the nuclear factor erythroid 2-related factor 2(Nrf2),heme oxygenase-1(HO-1),and the NAD(P)H-quinone oxidoreductase 1(NQO-1)protein expression by Western blot.RESULTS As compared to vehicle-treated animals,imperatorin treatment significantly reduced the ROS,MDA,NO levels and i NOS activity,increased T-AOC and the activities of SOD and CAT.Furthermore,imperatorin treatment also significantly induced the nuclear translocation of Nrf2,enhanced the protein expression of HO-1 and NQO-1 in the cerebral cortex and hippocampus.CONCLUSION Our findings indicate that imperatorin can protect the brain against the excessive oxidative stress induced by cerebral ischemia/reperfusion through activation of Nrf2 signaling pathway.

地方媒体助力乡村振兴角色及路径研究

乡村振兴战略是一项系统化工程,需要多方协同形成合力,媒体的宣传、引导、监督等功能在实施乡村振兴中发挥着特殊的作用。如何推动媒体有效参与并服务于乡村振兴战略是当前我国媒体面临的重要课题,尤其是在实施乡村振兴战略的背景下,地方媒体发挥着描绘乡村振兴实践图谱的作用,在挖掘乡村故事、提升媒体报道的传播力和影响力、具有天然的优势。随着互联网技术的更迭,地方媒体既有机遇,也面临着挑战,如何做好角色、转变路径助力乡村振兴,更应该引起重视和研究。

Isolation and Identification of Pathogenic Fungi in Kiwifruit during the Storage Period

[Objectives]The paper was to identify the pathogenic species of postharvest diseases of kiwifruit.[Methods]The pathogenic fungi were isolated from diseased kiwifruits during the storage period,and cultured to observe their culture traits and morphological characteristics.Molecular biological identification and pathogenicity test were carried out to confirm the main pathogens.[Results]There were 7 species of pathogenic fungi causing kiwifruit diseases during the storage period,including Alternaria spp.,Botryosphaeria dothidea,Phomopsis/Diaporthe spp.,Pestalotiopsis sp.,Pseudocercospora sp.,Colletotrichum sp.,and Botrytis cinerea.[Conclusions]The research will provide a scientific basis for the prevention and control of postharvest diseases of kiwifruit.

Tyrosine Aminotransferase Gene (SmTAT) Revealed Genetic Diversity and Phylogeny of Cultivated Danshen (Salvia miltiorrhiza) Populations

Chinese traditional medicine Danshen is the radix of the perennial herbs of Salvia miltiorrhiza Bunge, which has a variety of pharmacological effects and is traditionally and extensively applied clinically to treat cardiovascular disorders. In this research, the genomic genes for tyrosine aminotransferase (TAT) of 38 cultivated populations of Danshen in China were cloned and bioinformatic analyses were conducted to reveal its genetic diversity and phylogeny. The full-length SmTAT was 2296 - 2444 bp including 6 exons (encoding 411 amino acids) and 5 introns. Overall, the SmTAT genes in cultivated Danshen populations are highly conserved with a relative low level of genetic diversity. The spliced exons (1236 bp) had 23 SNP variations with a rate of 1.86%, of which 22 occurred in the white flower S. miltiorrhiza Bge.f.alba population (W-SCHY-W-1) and led to 5 amino acid variations. The entire 290 SNP variations with a rate of 24% in the 5 introns occurred exclusively in W-SCHY-W-1. Phylogenetic trees based on the full-length, combined introns, the spliced exons, and the deduced amino acid sequences of SmTAT all showed a two-clade basic structure with W-SCHY-W-1 uniquely standing alone. The SmTAT gene of the white flower population (W-SCHY-W-1) is unique and especially rich in variations. The first time clarified genomic SmTAT gene structure and genetic diversity in cultivated Danshen populations laid an excellent foundation for further studies on the biosynthesis of bioactives and the molecular breeding of Danshen as well as in plant tyrosine metabolism.

Pathway-selective suppression of chemokine receptor signaling in B cells by LPS through downregulation of PLC-b2

Lymphocyte activation leads to changes in chemokine receptor expression.There are limited data,however,on how lymphocyte activators can alter chemokine signaling by affecting downstream pathways.We hypothesized that B cell-activating agents might alter chemokine responses by affecting downstream signal transducers,and that such effects might differ depending on the activator.We found that activating mouse B cells using either anti-IgM or lipopolysaccharide(LPS)increased the surface expression of CCR6 and CCR7 with large increases in chemotaxis to their cognate ligands.By contrast,while anti-IgM also led to enhanced calcium responses,LPS-treated cells showed only small changes in calcium signaling as compared with cells that were freshly isolated.Of particular interest,we found that LPS caused a reduction in the level of B-cell phospholipase C(PLC)-b2 mRNA and protein.Data obtained using PLC-b22/2 mice showed that the b2 isoform mediates close to one-half the chemokine-induced calcium signal in resting and anti-IgM-activated B cells,and we found that calcium signals in the LPS-treated cells were boosted by increasing the level of PLC-b2 using transfection,consistent with a functional effect of downregulating PLC-b2.Together,our results show activator-specific effects on responses through B-cell chemokine receptors that are mediated by quantitative changes in a downstream signal-transducing protein,revealing an activity for LPS as a downregulator of PLC-b2,and a novel mechanism for controlling chemokine-induced signals in lymphocytes.