棒状腐败乳杆菌Lc7的生物学特性及益生作用

【目的】对分离自健康成人粪便样本的棒状腐败乳杆菌(Loigolactobacillus coryniformis)Lc7进行分类学鉴定和益生潜力评估。【方法】基于16SrRNA基因和基因组核心基因构建系统发育树,对Lc7进行分类学鉴定;通过耐酸和胆汁酸盐、粘附、抗氧化和抑菌实验,以及溶血、明胶酶活性和抗菌药物敏感性实验,评估Lc7的益生特性。同时,构建小鼠溃疡性结肠炎模型,评估Lc7的体内抗炎潜力。【结果】Lc7鉴定为L. coryniformis,在酸和胆汁酸盐的连续作用下,Lc7的存活率为70.17%。Lc7对HT-29细胞的粘附指数为56.33 CFU/cell,其自聚集和疏水性分别为80%和40%;Lc7对福氏志贺菌和鼠伤寒沙门菌等7个常见致病菌均有较强的抑制能力;对1,1-二苯基-2-苦基肼(1,1-diphenyl-2-picryl-hydrazyl,DPPH)和羟自由基(hydroxyl radicals,·OH)的清除率分别为91.70%和48.53%;Lc7无溶血现象和明胶酶活性,对选取的大多数抗生素均敏感。在小鼠结肠炎实验中,Lc7干预组小鼠结肠长度明显长于模型组(...     

帝萝花‘璀璨明珠'的植株高效再生

为解决木本切花植物帝萝花‘璀璨明珠’繁殖效率低的问题,该文以帝萝花‘璀璨明珠’的幼嫩枝芽为外植体,研究了不同基本培养基对其长势的影响、不同激素种类和浓度对其增殖和生根的效果,分析了其离体繁殖的生长特点,并建立了高效的帝萝花‘璀璨明珠’组培快繁技术体系。结果表明:帝萝花‘璀璨明珠’幼嫩枝芽的消毒方法为0.1%的升汞溶液浸泡12 min,污染率为21.5%;外植体在WPM+ZT 1 mg·L~(-1)+NAA 0.1 mg·L~(-1)培养基上,侧芽萌发率为73%;增殖的最佳培养基为MS+BA 0.4 mg·L~(-1)+NAA 0.05 mg·L~(-1),增殖系数为6.63,增殖方式为侧芽增殖和植株基部丛生芽增殖;生根的适宜培养基为MS+IBA 0.75mg·L~(-1)+NAA 1 mg·L~(-1),生根率为70%;生根瓶苗移栽于珍珠岩和细草炭(体积比为0.5∶1)的基质中,光照强度为10 000～12 000 lx,空气湿度为70%～80%下培养,60 d后成活率可达72%。该研究结果为帝萝花组培种苗的商业化生产提供了技术支撑,同时促进了该高档木本切花的推广和种植及产业化。     

Responses of soil labile organic carbon and water-stable aggregates to reforestation in southern subtropical China

中国南亚热带土壤易分解有机碳和水稳性团聚体对造林的响应 造林被认为可以提高土壤碳稳定性并促进土壤碳累积。然而,实验结果差异很大,造林在提高土壤碳稳定性方面的作用仍存在争议。因此,在森林生态系统中不同土壤碳库对造林如何响应目前尚不清楚。基于此,本文对亚热带地区的尾叶桉林(Eucalyptus urophylla)、厚荚相思林(Acacia crassicarpa)、 红锥林(Castanopsis hystrix)、10树种混交林和自然恢复草坡等5种不同林型的土壤碳组分进行了研究,评估其不同土层(0–10、10–20、20–40 和40–60 cm)中的土壤易分解有机碳(容易被高锰酸钾氧化的有机碳ROC和土壤可溶性有机碳DOC)及土壤团聚体相关的碳对造林的响应。实验结果表明,造林(与自然恢复草坡比较)和林型并没有显著影响土壤ROC浓度,而自然恢复草坡土壤的DOC浓度在4个土层中均最高。0–10 cm土层中各径级的土壤团聚体其碳(C)浓度均是红锥林最高。此外,在任一土层中,林型对不同径级土壤水稳性团聚体比例的影响均不显著。但是土壤深度显著改变土壤团聚体的分布,0–20 cm土层主要为>0.25 mm粒径的团聚体,20–60 cm土层则是0.053–2 mm粒径的团聚体占主导。这些结果显示造林和林型影响土壤DOC 和团聚体C,而且它们相比于ROC对造林的响应更为敏感。研究发现,与自然恢复相比,人工林降低了土壤DOC浓度,暗示它可能会减少土壤C的淋溶损失。此外,红锥林能够通过物理保护提高表土层中土壤碳的稳定性。本研究为关注土壤碳汇功能时的中国南亚热带地区造林树种选择提供了有价值的信息。     

LBX2-AS1 promotes ovarian cancer progression by facilitating E2F2 gene expression via miR-455-5p and miR-491-5p sponging

LBX2-AS1 is a long non-coding RNA that facilitates the development of gastrointestinal cancers and lung cancer, but its participation in ovarian cancer development remained uninvestigated. Clinical data retrieved from TCGA ovarian cancer database and the clinography of 60 ovarian cancer patients who received anti-cancer treatment in our facility were analysed. The overall cell growth, colony formation, migration, invasion, apoptosis and tumour formation on nude mice of ovarian cancer cells were evaluated before and after lentiviral-based LBX2-AS1 knockdown. ENCORI platform was used to explore LBX2-AS1-interacting microRNAs and target genes of the candidate microRNAs. Luciferase reporter gene assay and RNA pulldown assay were used to verify the putative miRNA-RNA interactions. Ovarian cancer tissue specimens showed significant higher LBX2-AS1 expression levels that non-cancerous counterparts. High expression level of LBX2-AS1 was significantly associated with reduced overall survival of patients. LBX2-AS1 knockdown significantly down-regulated the cell growth, colony formation, migration, invasion and tumour formation capacity of ovarian cancer cells and increased their apoptosis in vitro. LBX2-AS1 interacts with and thus inhibits the function of miR-455-5p and miR-491-5p, both of which restrained the expression of E2F2 gene in ovarian cancer cells via mRNA targeting. Transfection of miRNA inhibitors of these two miRNAs or forced expression of E2F2 counteracted the effect of LBX2-AS1 knockdown on ovarian cancer cells. LBX2-AS1 was a novel cancer-promoting lncRNA in ovarian cancer. This lncRNA increased the cell growth, survival, migration, invasion and tumour formation of ovarian cancer cells by inhibiting miR-455-5p and miR-491-5p, thus liberating the expression of E2F2 cancer-promoting gene.     

Protein C‐terminal enzymatic labeling identifies novel caspase cleavages during the apoptosis of multiple myeloma cells induced by kinase inhibition

Caspase activation and proteolytic cleavages are the major events in the early stage of apoptosis. Identification of protein substrates cleaved by caspases will reveal the occurrence of the early events in the apoptotic process and may provide potential drug targets for cancer therapy. Although several N‐terminal MS‐based proteomic approaches have been developed to identify proteolytic cleavages, these methods have their inherent drawbacks. Here we apply a previously developed proteomic approach, protein C‐terminal enzymatic labeling (ProC‐TEL), to identify caspase cleavage events occurring in the early stage of the apoptosis of a myeloma cell line induced by kinase inhibition. Both previously identified and novel caspase cleavage sites are detected and the reduction of the expression level of several proteins is confirmed biochemically upon kinase inhibition although the current ProC‐TEL procedure is not fully optimized to provide peptide identifications comparable to N‐terminal labeling approaches. The identified cleaved proteins form a complex interaction network with central hubs determining morphological changes during the apoptosis. Sequence analyses show that some ProC‐TEL identified caspase cleavage events are unidentifiable when traditional N‐terminomic approaches are utilized. This work demonstrates that ProC‐TEL is a complementary approach to the N‐terminomics for the identification of proteolytic cleavage events such as caspase cleavages in signaling pathways.     

Effects of Latanoprost and Bimatoprost on the Expression of Molecules Relevant to Ocular Inflow and Outflow Pathways

Background and Purpose

The intraocular pressure (IOP)-lowering and side effects in response to different prostaglandin F₂α analogues can be variable, but, the underlying basis for this difference remains unknown. This study investigated the differential changes of cellular proteins relevant to IOP-lowering effects of latanoprost and bimatoprost.

Methods

The human T lymphoblast (MOLT-3) cell line and immortalized human trabecular meshwork (iHTM) cells were studied by quantitative PCR and by immunofluorescence after treatment with either latanoprost or bimatoprost. New Zealand white rabbit eyes were treated topically with each agent and, following euthanasia, anterior segment tissues were studied with immunostaining.

Results

In cultured MOLT-3 cells, mRNA expression of both c-fos and matrix metalloproteinase 9 increased significantly in response to each agent. In addition, there was little change in tissue inhibitor of metalloproteinase (TIMP)-3 mRNA, but a significant decrease in TIMP-4. Fibronectin mRNA in MOLT-3 cells was down-regulated with bimatoprost, but was up-regulated with latanoprost. Immunofluorescence analysis of iHTM cells showed that intracellular fibronectin was significantly decreased by bimatoprost, but was increased by latanoprost. Both latanoprost and bimatoprost increased mRNA expression of NF-кB p65 and decreased that of IкBα. Aquaporin-1 mRNA expression was significantly down-regulated by bimatoprost. Immunostaining also revealed a significant decrease of aquaporin-1 in the ciliary epithelium of New Zealand white rabbits after bimatoprost treatment.

Conclusions

Similarities in protein expression produced by latanoprost and bimatoprost in vitro may be relevant to the mechanism for their IOP-lowering effects in vivo. Differences in fibronectin expression and in aquaporin-1 expression in response to each agent may contribute to variability in the IOP-lowering efficacy in some studies.     

Maternal serum-derived exosomal lactoferrin as a marker in detecting and predicting ventricular septal defect in fetuses

Among different types of congenital heart diseases, ventricular septal defect is the most frequently diagnosed type and is frequently missed in early prenatal screening programs. Herein, we explored the role of maternal serum-derived exosomes in detecting and predicting ventricular septal defect in fetuses in the early stage of pregnancy. A total of 104 pregnant women consisting of 52 ventricular septal defect cases and 52 healthy controls were recruited. TMT/iTRAQ proteomic analysis uncovered 15 maternal serum exosomal proteins, which showed differential expression between ventricular septal defect and control groups. Among these, four down-regulated proteins, lactoferrin, SBSN, DCD, and MBD3, were validated by Western blot. The protein lactoferrin was additionally verified by ELISA which was able to distinguish ventricular septal defects from controls with area under the ROC curve (AUC) 0.804 (p < 0.001). Our findings reveal that lactoferrin in maternal serum-derived exosomes may be a potential biomarker for non-invasive prenatal diagnosis of fetal ventricular septal defects.     

Heterotrimeric G alpha q/G alpha 11 proteins function upstream of vascular endothelial growth factor (VEGF) receptor-2 (KDR) phosphorylation in vascular permeability factor/VEGF signaling

Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) functions by activating two receptor-tyrosine kinases, Flt-1 (VEGF receptor (VEGFR)-1) and KDR (VEGFR-2), both of which are selectively expressed on primary vascular endothelium. KDR is responsible for VPF/VEGF-stimulated endothelial cell proliferation and migration, whereas Flt-1 down-modulates KDR-mediated endothelial cell proliferation. Our most recent works show that pertussis toxin-sensitive G proteins and Gbetagamma subunits are required for Flt-1-mediated down-regulation of human umbilical vein endothelial cell (HUVEC) proliferation and that Gq/11 proteins are required for KDR-mediated RhoA activation and HUVEC migration. In this study, we demonstrate that Gq/11 proteins are also required for VPF/VEGF-stimulated HUVEC proliferation. Our results further indicate that Gq/11 proteins specifically mediate KDR signaling such as intracellular Ca2+ mobilization rather than Flt-1-induced CDC42 activation and that a Gq/11 antisense oligonucleotide completely inhibits MAPK phosphorylation induced by KDR but has no effect on Flt-1-induced MAPK activation. More importantly, we demonstrate that Gq/11 proteins interact with KDR in vivo, and the interaction of Gq/11 proteins with KDR does not require KDR tyrosine phosphorylation. Surprisingly, the Gq/11 antisense oligonucleotide completely inhibits VPF/VEGF-stimulated KDR phosphorylation. Expression of a constitutively active mutant of G11 but not Gq can cause phosphorylation of KDR and MAPK. In addition, a Gbetagamma minigene, hbetaARK1(495), inhibits VPF/VEGF-stimulated HUVEC proliferation, MAPK phosphorylation, and intracellular Ca2+ mobilization but has no effect on KDR phosphorylation. Taken together, this study demonstrates that Gq/11 proteins mediate KDR tyrosine phosphorylation and KDR-mediated HUVEC proliferation through interaction with KDR.