Curcumin protects against ovariectomy-induced bone loss and decreases osteoclastogenesis

Curcumin has anti-oxidative activity. In view of the increasing evidence for a biochemical link between increased oxidative stress and reduced bone density we hypothesized that curcumin might increase bone density by elevating antioxidant activity in some target cell type. We measured bone density by Micro-CT, enzyme expression levels by quantitative PCR or enzyme activity, and osteoclast (OC) formation by tartrate-resistant acid phosphatase staining. The bone mineral density of the femurs of curcumin-administered mice was significantly higher than that of vehicle-treated mice after ovariectomy (OVX) and this was accompanied by reduced amounts of serum collagen-type I fragments, which are markers of bone resorption. Curcumin suppressed OC formation by increasing receptor activator of nuclear factor-κB ligand (RANKL)-induced glutathione peroxidase-1, and reversed the stimulatory effect of homocysteine, a known H(2) O(2) generator, on OC formation by restoring Gpx activity. Curcumin generated an aberrant RANKL signal characterized by reduced expression of nuclear factor of activated T cells 2 (NFAT2) and attenuated activation of mitogen-activated protein kinases (ERK, JNK, and p38). Curcumin thus inhibited OVX-induced bone loss, at least in part by reducing osteoclastogenesis as a result of increased antioxidant activity and impaired RANKL signaling. These findings suggest that bone loss associated with estrogen deficiency could be attenuated by curcumin administration.     

百色地区民族民间植物崇拜文化与生物多样性保护

植物崇拜是人类崇尚自然、敬畏生命这一朴素理念的基本体现。为了解百色地区民族民间植物崇拜文化内涵及其对生物多样性保护和管理的影响,该文采用民族植物学方法调查了百色地区民族民间植物崇拜文化及其文化特征,从自然崇拜、传统节日文化、生命礼俗和传统医药等方面探讨了百色地区民族民间植物文化对生物多样性保护的作用。结果表明:百色地区民族民间植物文化内涵丰富,具有丰富的生物多样性。百色地区民族民间崇拜植物分属53个种、47个属、28个科。其中,蔷薇科和豆科种类最多,分别为5种; 其次是桑科和禾本科,分别为4种。从生活型的组成来看,乔木植物占绝对优势,有39种,占总种数的73.58%; 草本11种,占总种数的20.75%; 灌木3种,占总种数的5.67%。其中,有4种植物在中国珍稀濒危植物信息系统中被列为国家Ⅱ级名录(闽楠、蚬木、格木、红椿),有5种植物被列为各省市区(地方)保护野生植物名录(红楠、广西青冈、桃金娘、苏木、黄檀)。这些植物形成了多样的植物群落,对百色地区植物多样性保护具有重要的促进作用。     

叶酸靶向载顺铂羧甲基-β-环糊精纳米复合物的制备及对鼻咽癌的体外抑制效应

为达到鼻咽癌（nasopharyngeal carcinoma,NeC）的靶向化疗,该研究通过酰胺化反应和配位偶联技术制备叶酸（folicacid,FA）分子靶向载川页铂（cisplatin,CDDP）羧甲基-β-环糊精（carboxymethyl-β-cyclodextrin,CM—β—CD）纳米复合物（FA-CM—β—CD—CDDP）,采用邻苯二胺（o-phenylenediamine,OPDA）比色法检测复合物中CDDP含量,紫外分光光谱检测FA含量,透射电镜观察复合物形态,激光粒度仪测定复合物粒径大小。荧光显微镜观察NPC叶酸受体（folatereceptor,FR）阳性HNE-1细胞及FR阴性CNE-2细胞对偶联FITC的复合物的吞噬及OPDA比色法检测细胞内CDDP的浓度。通过MTT法、集落形成实验和流式细胞术检测复合物对HNE-1细胞增殖能力和凋亡的影响。研究结果显示,复合物中偶联的FA和CDDP浓度分别为340gg／mL和2mg／mL,CDDP包封率达20．00％,复合物粒径均匀且大小为157．8nm。HNE-1细胞内见较多FITC,细胞内CDDP浓度为6．24ng／mL,而CNE-2细胞内FITC较少,细胞内CDDP浓度仅约2．01ng／mL。HNE-1生长抑制率在24h明显高于对照组（CM—β—CD—CDDP）,其IC50（4．80μg／mL）明显低于对照组（6．97μg／mL）,但当所载的CDDP终浓度达到16．00μg／mL时,两组抑制率均达到80％以上;作用48h两组抑制率无明显差异。在24h,当复合物的CDDP终浓度为1．00μg／mL时,HNE—1的集落形成率为33．21％,明显低于对照组（52．27％）。当复合物的CDDP终浓度为0．25μg／mL和1．00μg／mL时,HNE-1的凋亡率分别达12．65％和22．35％,明显高于对照组（6．91％和14.21％）。研究结果表明,成功构建的FA—CM—β—CD．cDDP纳米复合物能够靶向抑制FR阳性的NPC细胞增殖并促进其凋亡。     

Apparent Reduction of ADAM10 in Scrapie-Infected Cultured Cells and in the Brains of Scrapie-Infected Rodents

It has been described that A disintegrin and metalloproteinase (ADAM10) may involve in the physiopathology of prion diseases, but the direct molecular basis still remains unsolved. In this study, we confirmed that ADAM10 was able to cleave recombinant human prion protein in vitro. Using immunoprecipitation tests (IP) and immunofluorescent assays (IFA), reliable molecular interaction between the native cellular form of PrP (PrP^C) and ADAM10 was observed not only in various cultured neuronal cell lines but also in brain homogenates of healthy hamsters and mice. Only mature ADAM10 (after removal of its prodomain) molecules showed the binding activity with the native PrP^C. Remarkably more prion protein (PrP)-ADAM10 complexes were detected in the membrane fraction of cultured cells. In the scrapie-infected SMB cell model, the endogenous ADAM10 levels, especially the mature ADAM10, were significantly decreased in the fraction of cell membrane. IP and IFA tests of prion-infected SMB-S15 cells confirmed no detectable PrP-ADAM10 complex in the cellular lysates and PrP-ADAM10 co-localization on the cell surface. Furthermore, we demonstrated that the levels of ADAM10 in the brain homogenates of scrapie agent 263K-infected hamsters and agent ME7-infected mice were also almost diminished at the terminal stage, showing time-dependent decreases during the incubation period. Our data here provide the solid molecular basis for the endoproteolysis of ADAM10 on PrP molecules and interaction between ADAM10 and PrP^C. Obvious loss of ADAM10 during prion infection in vitro and in vivo highlights that ADAM10 may play essential pathophysiological roles in prion replication and accumulation.     

Rice OsPAD4 functions differently from Arabidopsis AtPAD4 in host‐pathogen interactions

The extensively studied Arabidopsis phytoalexin deficient 4 (AtPAD4) gene plays an important role in Arabidopsis disease resistance; however, the function of its sequence ortholog in rice is unknown. Here, we show that rice OsPAD4 appears not to be the functional ortholog of AtPAD4 in host‐pathogen interactions, and that the OsPAD4 encodes a plasma membrane protein but that AtPAD4 encodes a cytoplasmic and nuclear protein. Suppression of OsPAD4 by RNA interference (RNAi) increased rice susceptibility to the biotrophic pathogen Xanthomonas oryzae pv. oryzae (Xoo), which causes bacteria blight disease in local tissue. OsPAD4‐RNAi plants also show compromised wound‐induced systemic resistance to Xoo. The increased susceptibility to Xoo was associated with reduced accumulation of jasmonic acid (JA) and phytoalexin momilactone A (MOA). Exogenous application of JA complemented the phenotype of OsPAD4‐RNAi plants in response to Xoo. The following results suggest that OsPAD4 functions differently than AtPAD4 in response to pathogen infection. First, OsPAD4 plays an important role in wound‐induced systemic resistance, whereas AtPAD4 mediates systemic acquired resistance. Second, OsPAD4‐involved defense signaling against Xoo is JA‐dependent, but AtPAD4‐involved defense signaling against biotrophic pathogens is salicylic acid‐dependent. Finally, OsPAD4 is required for the accumulation of terpenoid‐type phytoalexin MOA in rice‐bacterium interactions, but AtPAD4‐mediated resistance is associated with the accumulation of indole‐type phytoalexin camalexin.     

Deep sequencing of the ancestral tobacco species Nicotiana tomentosiformis reveals multiple T‐DNA inserts and a complex evolutionary history of natural transformation in the genus Nicotiana

Nicotiana species carry cellular T‐DNA sequences (cT‐DNAs), acquired by Agrobacterium‐mediated transformation. We characterized the cT‐DNA sequences of the ancestral Nicotiana tabacum species Nicotiana tomentosiformis by deep sequencing. N. tomentosiformis contains four cT‐DNA inserts derived from different Agrobacterium strains. Each has an incomplete inverted‐repeat structure. TA is similar to part of the Agrobacterium rhizogenes 1724 mikimopine‐type T‐DNA, but has unusual orf14 and mis genes. TB carries a 1724 mikimopine‐type orf14‐mis fragment and a mannopine‐agropine synthesis region (mas2‐mas1‐ags). The mas2′ gene codes for an active enzyme. TC is similar to the left part of the A. rhizogenes A4 T‐DNA, but also carries octopine synthase‐like (ocl) and c‐like genes normally found in A. tumefaciens. TD shows a complex rearrangement of T‐DNA fragments similar to the right end of the A4 TL‐DNA, and including an orf14‐like gene and a gene with unknown function, orf511. The TA, TB, TC and TD insertion sites were identified by alignment with N. tabacum and Nicotiana sylvestris sequences. The divergence values for the TA, TB, TC and TD repeats provide an estimate for their relative introduction times. A large deletion has occurred in the central part of the N. tabacum cv. Basma/Xanthi TA region, and another deletion removed the complete TC region in N. tabacum. Nicotiana otophora lacks TA, TB and TD, but contains TC and another cT‐DNA, TE. This analysis, together with that of Nicotiana glauca and other Nicotiana species, indicates multiple sequential insertions of cT‐DNAs during the evolution of the genus Nicotiana.     

Green‐lighting green fluorescent protein: Faster and more efficient folding by eliminating a cis–trans peptide isomerization event

Wild‐type green fluorescent protein (GFP) folds on a time scale of minutes. The slow step in folding is a cis–trans peptide bond isomerization. The only conserved cis‐peptide bond in the native GFP structure, at P89, was remodeled by the insertion of two residues, followed by iterative energy minimization and side chain design. The engineered GFP was synthesized and found to fold faster and more efficiently than its template protein, recovering 50% more of its fluorescence upon refolding. The slow phase of folding is faster and smaller in amplitude, and hysteresis in refolding has been eliminated. The elimination of a previously reported kinetically trapped state in refolding suggests that X‐P89 is trans in the trapped state. A 2.55 Å resolution crystal structure revealed that the new variant contains only trans‐peptide bonds, as designed. This is the first instance of a computationally remodeled fluorescent protein that folds faster and more efficiently than wild type.