CCL7 contributes to angiotensin II-induced abdominal aortic aneurysm by promoting macrophage infiltration and pro-inflammatory phenotype

Chemokine C-C motif ligand 7 (CCL7), a member of CC chemokine subfamily, plays pivotal roles in numerous inflammatory diseases. Hyper-activation of inflammation is an important characteristic of abdominal aortic aneurysm (AAA). Therefore, in the present study, we aimed to determine the effect of CCL7 on AAA formation. CCL7 abundance in aortic tissue and macrophage infiltration were both increased in angiotensin II (Ang II)-induced AAA mice. Ex vivo, CCL7 promoted macrophage polarization towards M1 phenotype. This effect was reversed by the blockage of CCR1, a receptor of CCL7. CCL7 up-regulated JAK2/STAT1 protein level in macrophage, and CCL7-induced M1 activation was suppressed by JAK2/STAT1 pathway inhibition. To verify the effect of CCL7 on AAA in vivo, either CCL7-neutralizing antibody (CCL7-nAb) or vehicles were intraperitoneally injected 24 hours prior to Ang II infusion and subsequently every three days for 4 weeks. CCL7-nAb administration significantly attenuated Ang II-induced luminal and external dilation as well as pathological remodelling. Immunostaining showed that CCL7-nAb administration significantly decreased aneurysmal macrophage infiltration. In conclusion, CCL7 contributed to Ang II-induced AAA by promoting M1 phenotype of macrophage through CCR1/JAK2/STAT1 signalling pathway.     

Recombinant neuritin affects the senescence,apoptosis, proliferation,and migration of rat bone marrow-derived mesenchymal stem cells

Objective

To study the effects of recombinant neuritin expressed by Pichia pastoris GS115 on the senescence, apoptosis, proliferation, and migration associated with rat bone marrow-derived mesenchymal stem cells (BMSCs).

Results

Recombinant neuritin was purified by Ni-affinity chromatography and identified by western blot and MALDI-TOF spectrometry. The effects of recombinant neuritin on senescence, apoptosis, proliferation, and migration of rat BMSCs WERE investigated. β-Galactosidase staining indicated that recombinant neuritin administration significantly inhibited BMSCs senescence at 1 μg neuritin/ml. Additionally, recombinant neuritin reduced the number of apoptotic cells at the early stage according to Annexin V/propidium iodide staining and inhibited cell proliferation according to MTT assay results. Moreover wound healing assay results showed that recombinant neuritin promoted BMSCs migration in the neuritin-treatment group.

Conclusion

Recombinant neuritin affects the senescence, apoptosis, proliferation, migration of rat BMSCs. Our findings offer insight into neuritin function outside of the nervous system.

     

石榴木质素合成相关基因PgMYB308的克隆和表达分析

该研究以‘红玉石籽’(Punica granatumcv.Hongyushizi)石榴为试验材料,采用RACE和RT-PCR方法,获得与木质素的合成相关基因PgMYB308。PgMYB308基因cDNA全长792bp,编码263个氨基酸。分子量为29.56kD,理论等电点为9.07。序列比对和功能域分析发现,PgMYB308包含R2和R3保守域,以及C1、C2、C4和锌指基序。系统进化树分析显示,PgMYB308与其他物种起源相同,而与桉树EgMYB308亲缘关系最近。荧光定量PCR分析表明,PgMYB308在茎、叶和种子等组织中均有表达,其中茎中表达量最高,叶片中表达量最低;PgMYB308在‘突尼斯软籽’中表达最高,而在‘红玉石籽’和‘白玉石籽’中表达量较低;PgMYB308在‘红玉石籽’籽粒的不同时期均有表达,但在花后20d相对表达量最高,以后随发育进程呈现逐渐下降的趋势。     

Capturing the photo‐signaling state of a photoreceptor in a steady‐state fashion by binding a transition metal complex

Binding a small molecule to proteins causes conformational changes, but often to a limited extent. Here, we demonstrate that the interaction of a CO‐releasing molecule (CORM3) with a photoreceptor photoactive yellow protein (PYP) drives large structural changes in the latter. The interaction of CORM3 and a mutant of PYP, Met100Ala, not only trigger the isomerization of its chromophore, p‐coumaric acid, from its anionic trans configuration to a protonated cis configuration, but also increases the content of β‐sheet at the cost of α‐helix and random coil in the secondary structure of the protein. The CORM3 derived Met100Ala is found to highly resemble the signaling state, which is one of the key photo‐intermediates of this photoactive protein, in both protein local conformation and chromophore configuration. The organometallic reagents hold promise as protein engineering tools. This work highlights a novel approach to structurally accessing short lived intermediates of proteins in a steady‐state fashion.     

颍上八里河自然保护区鹭卵p3种重金属残留分析

2005年5月,采集了淮河地区颍上八里河集群繁殖的夜鹭（Nycticorax nycticorax）和小白鹭（Egretta garzetta）鸟卵共18枚,用原子吸收法测定了卵壳、内容物中重金属Cd、Pb、Cr的残留量。结果表明,所有卵壳样品中均检出一定水平的Cd、Pb和Cr残留量,夜鹭卵壳中重金属残留量为Pb〉Cr〉Cd,小白鹭卵壳中重金属残留量为Cr〉Pb〉Cd,卵壳中Pb和Cr残留量的种间差异都不显著,但Cd的种间差异显著;在2种鹭卵内容物中,Cr都被检出,在夜鹭卵内容物样品中,Pb只被部分检出,Cd在2种鹭卵内容物样品中都没有被检出,3种重金属在内容物中残留量的种间差异都不显著。2种鹭卵壳中Pb和Cd残留量极其显著地高于卵内容物,但Cr的这种残留分布上的差异不显著。本研究进一步证明卵壳可用作重金属污染物的指示物,监测和评价湿地生态系统中重金属的污染状况。     

Two Novel Bacteriophages of Thermophilic Bacteria Isolated from Deep-Sea Hydrothermal Fields

Bacteriophages of thermophiles are of great interest due to their important roles in many biogeochemical and ecological processes. However, no virion has been isolated from deep-sea thermophilic bacteria to date. In this investigation, two lytic bacteriophages (termed Bacillus virus W1 and Geobacillus virus E1) of thermophilic bacteria were purified from deep-sea hydrothermal fields in the Pacific for the first time. Bacillus virus W1 (BVW1) obtained from Bacillus sp. w13, had a long tail (300nm in length and 15 nm in width) and a hexagonal head (70 nm in diameter). Another virus, Geobacillus virus E1 (GVE1) from Geobacillus sp. E26323, was a typical Siphoviridae phage with a hexagonal head (130 nm in diameter) and a tail (180 nm in length and 30 nm in width). The two phages contained double-stranded genomic DNAs. The genomic DNA sizes of BVW1 and GVE1 were estimated to be about 18 and 41 kb, respectively. Based on SDS-PAGE of purified virions, six major proteins were revealed for each of the two phages. The findings in our study will be very helpful to realize the effect of virus on thermophiles as well as the communities in deep-sea hydrothermal fields.     

Demecolcine-induced enucleation of sheep meiotically maturing oocytes

The objective of this study was to investigate the possible effect of demecolcine, a microtubule-disrupting reagent, on induced enucleation (IE) of sheep meiotically maturing oocytes. Immunofluorescent staining with anti-tubulin antibodies was used to examine the spindle status of the oocytes. When the oocytes with intact germinal vesicles (GV) were cultured in the medium containing various concentrations of demecolcine (0.01 to 0.4 microg.mL-1) for 20 to 22 h, the spindle microtubule organization and first polar body (PB1) extrusion were inhibited by demecolcine in a dose-dependent manner. The highest IE rate (58.1%) was from the treatment with 0.04 microg.mL-1 demecolcine. Demecolcine treatment applied after germinal vesicle breakdown (GVBD) or at metaphase (M) yielded a PB1 extrusion rate and IE efficiency similar to the treatment applied at the onset of maturation. Analysis by immunofluorescence showed that both nonspindle microtubules and spindle microtubules were significantly disorganized by demecolcine. Combination treatment with demecolcine and cycloheximide (CHX) or 6-dimethylaminopurine (6-DMAP) led to single pronuclear formation rather than PB1 extrusion. When demecolcine-treated oocytes were transferred into demecolcine-free medium, the ability to extrude PB1 was quickly restored and a 72.1% IE rate was obtained following such treatment. These results demonstrate that demecolcine can be used as a potential reagent for induced enucleation of sheep meiotically maturing oocytes and may greatly facilitate research in nuclear transfer.