Effect of Weight Loss on High‐Molecular Weight Adiponectin in Obese Children

Our aim was to determine the influence of weight reduction on total (T‐) and high‐molecular weight (HMW‐) adiponectin in obese (OB) prepubertal children. Seventy OB prepubertal white patients were followed for 18 months and studied after reducing their BMI by 1 (n = 51) and 2 standard deviation scores (SDS) (n = 21) under conservative treatment, and 6 months after achieving weight loss (n = 44). Body composition dual‐energy X‐ray absorptiometry (DXA) and serum levels of T‐ and HMW‐adiponectin, resistin, leptin, leptin soluble receptor (sOB‐R), tumoral necrosis factor‐α and interleukin‐6 were determined. The control group consisted of 61 healthy prepubertal children. At diagnosis T‐adiponectin was higher (P < 0.01; confidence interval (+0.04) — (+0.15)) and HMW‐adiponectin lower (P < 0.001; confidence interval (?0.45) ? (?0.21)) in OB children than in controls. A reduction in body fat increased T‐ and HMW‐adiponectin and sOB‐R (all P < 0.001) and decreased leptin (P < 0.001) and interleukin‐6 levels (P < 0.05). After 6 months of sustained weight reduction a decrease in tumoral necrosis factor‐α (P < 0.01) occurred, whereas weight recovery increased leptin (P < 0.001) and decreased T‐adiponectin (P < 0.05). HMW‐adiponectin levels negatively correlated with homeostasis model assessment (HOMA) index and BMI in the whole cohort (both P < 0.001), as did T‐adiponectin levels and HOMA index in OB patients (P < 0.01), but neither T‐ nor HMW‐adiponectin correlated with body fat content (BFC) in OB children. We conclude that the impairment of T‐ and HMW‐adiponectin levels in childhood obesity is different to that in elder OB patients, showing closer relationship with carbohydrate metabolism parameters than with BFC, but increasing their levels after weight loss and in association with metabolic improvement.     

ERK1/2 MAP kinases promote cell cycle entry by rapid, kinase-independent disruption of retinoblastoma-lamin A complexes

As orchestrators of essential cellular processes like proliferation, ERK1/2 mitogen-activated protein kinase signals impact on cell cycle regulation. A-type lamins are major constituents of the nuclear matrix that also control the cell cycle machinery by largely unknown mechanisms. In this paper, we disclose a functional liaison between ERK1/2 and lamin A whereby cell cycle progression is regulated. We demonstrate that lamin A serves as a mutually exclusive dock for ERK1/2 and the retinoblastoma (Rb) protein. Our results reveal that, immediately after their postactivation entrance in the nucleus, ERK1/2 dislodge Rb from its interaction with lamin A, thereby facilitating its rapid phosphorylation and consequently promoting E2F activation and cell cycle entry. Interestingly, these effects are independent of ERK1/2 kinase activity. We also show that cellular transformation and tumor cell proliferation are dependent on the balance between lamin A and nuclear ERK1/2 levels, which determines Rb accessibility for phosphorylation/inactivation.     

Fibroblast and prostate tumor cell cross-talk: Fibroblast differentiation, TGF-β, and extracellular matrix down-regulation

Growth and survival of tumors at a site of metastasis involve interactions with stromal cells in the surrounding environment. Stromal cells aid tumor cell growth by producing cytokines as well as by modifying the environment surrounding the tumor through modulation of the extracellular matrix (ECM). Small leucine-rich proteoglycans (SLRPs) are biologically active components of the ECM which can be altered in the stroma surrounding tumors. The influence tumor cells have on stromal cells has been well elucidated. However, little is understood about the effect metastatic cancer cells have on the cell biology and behavior of the local stromal cells. Our data reveal a significant down-regulation in the expression of ECM components such as collagens I, II, III, and IV, and the SLRPs, decorin, biglycan, lumican, and fibromodulin in stromal cells when grown in the presence of two metastatic prostate cancer cell lines PC3 and DU145. Interestingly, TGF-β down-regulation was observed in stromal cells, as well as actin depolymerization and increased vimentin and α5β1 integrin expression. MT1-MMP expression was upregulated and localized in stromal cell protrusions which extended into the ECM. Moreover, enhanced stromal cell migration was observed after cross-talk with metastatic prostate tumor cells. Xenografting metastatic prostate cancer cells together with “activated” stromal cells led to increased tumorigenicity of the prostate cancer cells. Our findings suggest that metastatic prostate cancer cells create a metastatic niche by altering the phenotype of local stromal cells, leading to changes in the ECM.     

Phylogenetic relationships of the endemic Antarctic benthic hydroids (Cnidaria, Hydrozoa): what does the mitochondrial 16S rRNA tell us about it?

Hydroidolinan hydrozoans are widely represented in the benthic Antarctic ecosystem, mainly by some endemic and putative monophyletic groups, never included in molecular phylogenetic analyses. 38 partial sequences of the mitochondrial 16S rRNA gene were obtained for 38 species belonging to 14 families (six anthoathecates and eight leptothecates) and 20 genera (7 anthoathecates and 13 leptothecates). These sequences were combined with 108 additional sequences retrieved from the GenBank to investigate both the hypothetical monophyletism and the phylogenetic relationships of those endemic Antarctic groups; the potential use of the marker for barcoding was also investigated. Our results uphold the monophyly of some important hydroidolinan groups, such as the superfamily Plumularioidea (together with all its families, including Schizotrichidae, fam. nov.) and the Aplanulata. Concerning the Antarctic endemic groups, most results as monophyletic (Oswaldella, Schizotricha and Staurotheca), some genera form part of the expectable groups (e.g. Abietinella, located into the monophyletic Zygophylacinae clade) and, finally, others have shown a surprising position (e.g. Stegella, closely related to Lafoeinae, or Billardia and Stegopoma, allied with Hebellidae). Finally, our study has shown the utility of the marker to recognize the Antarctic species considered, but the low genetic divergence in some of the most important Antarctic groups suggests being careful when using it for DNA barcoding in the case of the original Antarctic hydroid fauna.     

Ectoines in cell stress protection: Uses and biotechnological production

Microorganisms produce and accumulate compatible solutes aiming at protecting themselves from environmental stresses. Among them, the wide spread in nature ectoines are receiving increasing attention by the scientific community because of their multiple applications. In fact, increasing commercial demand has led to a multiplication of efforts in order to improve processes for their production.     

Technological trends,global market,and challenges of bio-ethanol production

Ethanol use as a fuel additive or directly as a fuel source has grown in popularity due to governmental regulations and in some cases economic incentives based on environmental concerns as well as a desire to reduce oil dependency. As a consequence, several countries are interested in developing their internal market for use of this biofuel. Currently, almost all bio-ethanol is produced from grain or sugarcane. However, as this kind of feedstock is essentially food, other efficient and economically viable technologies for ethanol production have been evaluated. This article reviews some current and promising technologies for ethanol production considering aspects related to the raw materials, processes, and engineered strains development. The main producer and consumer nations and future perspectives for the ethanol market are also presented. Finally, technological trends to expand this market are discussed focusing on promising strategies like the use of microalgae and continuous systems with immobilized cells.     

A Mutation in the Lettuce Infectious Yellows Virus Minor Coat Protein Disrupts Whitefly Transmission but Not In Planta Systemic Movement

The Lettuce infectious yellows virus (LIYV) RNA 2 mutant p1-5b was previously isolated from Bemisia tabaci-transmitted virus maintained in Chenopodium murale plants. p1-5b RNA 2 contains a single-nucleotide deletion in the minor coat protein (CPm) open reading frame (ORF) that is predicted to result in a frameshift and premature termination of the protein. Using the recently developed agroinoculation system for LIYV, we tested RNA 2 containing the p1-5b CPm mutant genotype (agro-pR6-5b) in Nicotiana benthamiana plants. We showed that plant infection triggered by agro-pR6-5b spread systemically and resulted in the formation of virions similar to those produced in p1-5b-inoculated protoplasts. However, virions derived from these mutant CPm genotypes were not transmitted by whiteflies, even though virion concentrations were above the typical transmission thresholds. In contrast, and as demonstrated for the first time, an engineered restoration mutant (agro-pR6-5bM1) was capable of both systemic movement in plants and whitefly transmission. These results provide strong molecular evidence that the full-length LIYV-encoded CPm is dispensable for systemic plant movement but is required for whitefly transmission.Members of the genus Crinivirus are emerging plant viruses in many parts of the world. An important factor contributing to the increase in the incidence of these viruses is their association with and transmission by whitefly vectors that have increased in distribution in the last several decades. Lettuce infectious yellows virus (LIYV), the type member of the genus Crinivirus (family Closteroviridae), is specifically transmitted by the sweet potato whitefly, Bemisia tabaci biotype A, in a semipersistent, noncirculative manner (6). The virus is confined to phloem cells within infected plants and is not transmissible to plants by leaf rub inoculation. The bipartite single-stranded positive-sense LIYV genome components, consisting of RNA 1 (approximately 8.1 kb) and RNA 2 (approximately 7.2 kb), are separately encapsidated in flexuous filamentous particles that are characteristic of the family Closteroviridae (8, 11). These virions are comprised of four protein components: the major coat protein (CP), the minor coat protein (CPm), an Hsp70 homolog (Hsp70h), and a 59-kDa protein (P59). Like other viruses in the family Closteroviridae, LIYV has bipolar virions with a “body” composed mainly of the CP and a “head” that is formed by the assembly of CPm subunits (2, 4, 7, 22, 28). Hsp70h and P59 are detected in LIYV virions (22), but their locations have not been identified, as they are not readily detected by immunogold labeling and transmission electron microscopy (IGL-TEM). For two members of the family Closteroviridae, Citrus tristeza virus (CTV) and Beet yellows virus (BYV), the combination of Hsp70h, P61 (the homolog of LIYV P59 in CTV) or P64 (the homolog of LIYV P59 in BYV), and CPm encapsidates the 5′ end (∼630 to 650 nucleotides [nt]) of the RNA genome, demonstrating the complex interactions that exist among the capsid proteins and the genomic RNA (15, 21).In our previous studies, we demonstrated the transmission of LIYV using an in vitro acquisition and whitefly transmission system (13, 22). Results from previous work implicated a role for LIYV CPm in whitefly transmission. Antibodies to CPm blocked the in vitro acquisition/transmission of LIYV virion preparations by B. tabaci biotype A, while antibodies to CP, Hsp70h, and P59 did not (22). The in vitro whitefly membrane-feeding system had also been used to demonstrate B. tabaci biotype A transmission of virions that were derived from cloned infectious cDNAs of LIYV RNA 1 and RNA 2 of several genotypes, including pR6 (the first cloned wild-type [WT] infectious cDNA of LIYV RNA 2 [10]), establishing for the first time that these cloned constructs contained all of the information necessary for protoplast infection, virion formation, whitefly transmission, and infection in plants (12). In that study, the mutant p1-5b was among the cloned LIYV RNA 2 cDNAs derived from B. tabaci biotype A-transmitted virus maintained in Chenopodium murale plants.p1-5b contains a single-adenine-residue deletion in the CPm open reading frame (ORF) at nucleotide 592, a deletion that is predicted to result in a frameshift, 14 new amino acids, and premature termination of the protein (12). The predicted p1-5b CPm has 211 amino acids, compared to 453 amino acids in the wild-type (pR6 genotype) protein. The p1-5b genotype also contains three other nucleotide changes in the CPm ORF relative to the pR6 infectious clone sequence (27), all of which result in amino acid changes. In contrast, the p1-5b CP, Hsp70h, and P59 sequences are identical to that of pR6 (12). Possible polymorphisms throughout the rest of the p1-5b clone were not characterized. In a prior study, B. tabaci biotype A transmission of p1-5b virions was not observed, even though the mutation did not affect its infectivity in protoplasts (as determined by virion yields) and apparent particle morphology (12). However, those studies were disadvantaged by the necessity of propagation in protoplasts to obtain specific genotypes from infectious cloned cDNAs. Protoplasts yield low quantities of virion relative to plants, and virion concentration is a critical parameter in whitefly transmission (13). Although virion concentrations in those experiments were above typical thresholds for whitefly transmission (12, 13), low concentrations may still be limiting for transmission, making negative transmission results difficult to interpret. Obtaining adequate virion concentrations of specific genotypes for whitefly transmission to plants has therefore been a significant hurdle to LIYV transmission studies.The recently developed agroinoculation method for LIYV (24) permits the study of systemic plant infection by distinct LIYV genotypes, including those that are whitefly transmission deficient, and the recovery of higher virion yields than were possible using protoplasts. The objective of this study was to further examine the function of the LIVY CPm by extending our observations of p1-5b. We constructed mutants with the CPm frameshift restored to determine if engineered mutations that either restored or disrupted the formation of an intact CPm also affected systemic plant infection, virion formation, and B. tabaci biotype A transmission. Our study revealed that a mutant engineered with the restored CPm ORF produced a WT infection profile characterized by systemic virus movement within agroinoculated plants and the generation of CPm-containing virions that were whitefly transmissible. Intriguingly, systemic virus movement was also observed for a mutant engineered to express the 1-5b CPm, but the virions lacked an identifiable CPm and were defective in whitefly transmission. These results represent a significant advance in addressing challenging questions and hypotheses about Crinivirus whitefly transmission properties not testable using earlier systems.     

Kalirin: a novel genetic risk factor for ischemic stroke

Cerebrovascular and cardiovascular diseases are the leading causes of death and disability worldwide. They are complex disorders resulting from the interplay of genetic and environmental factors, and may share several susceptibility genes. Several recent studies have implicated variants of the Kalirin (KALRN) gene with susceptibility to cardiovascular and metabolic phenotypes, but no studies have yet been performed in stroke patients. KALRN is involved, among others, in the inhibition of inducible nitric oxide synthase, in the regulation of ischemic signal transduction, and in neuronal morphogenesis, plasticity, and stability. The goal of the present study was to determine whether SNPs in the KALRN region on 3q13, which includes the Ropporin gene (ROPN1), predispose to ischemic stroke (IS) in a cohort of Portuguese patients and controls. We genotyped 34 tagging SNPs in the KALRN and ROPN1 chromosomal region on 565 IS patients and 517 unrelated controls, and performed genotype imputation for 405 markers on chromosome 3. We tested the single-marker association of these SNPs with IS. One SNP (rs4499545) in the ROPN1–KALRN intergenic region and two SNPs in KALRN (rs17286604 and rs11712619) showed significant (P < 0.05) allelic and genotypic (unadjusted and adjusted for hypertension, diabetes, and ever smoking) association with IS risk. Thirty-two imputed SNPs also showed an association at P < 0.05, and actual genotyping of three of these polymorphisms (rs7620580, rs6438833, and rs11712039) validated their association. Furthermore, rs11712039 was associated with IS (0.001 < P < 0.01) in a recent well-powered genomewide association study (Ikram et al. 2009). These studies suggest that variants in the KALRN gene region constitute risk factors for stroke and that KALRN may represent a common risk factor for vascular diseases.     

Environmental constraints in the colonization sequence of roe deer (Capreolus capreolus Linnaeus, 1758) across the Iberian Mountains, Spain

Aim This paper describes the dispersal process of roe deer (Capreolus capreolus Linnaeus, 1758) with respect to climatic factors, landscape characteristics and human activity. We hypothesized that environmental characteristics constrain the relative abundance and dispersal process of roe deer. Location The study was conducted in the Iberian Mountains, north‐eastern Spain, during 1986–2000. Methods Roe deer colonization dates in the study area were obtained from a survey for large mammals and from direct interviews with the employees of the Fish and Game Agency. We used a 10 × 10 km UTM grid as the sampling unit (n = 91). The relative abundance of roe deer was estimated by counting the number of pellet groups in line transects, which were representative of the habitat availability in the 10 × 10 km UTM grid. Climatic factors were obtained from meteorological stations placed near to the plot. Landscape structure indices, topography and human activity factors were obtained from digital maps using fragstats 3.3 and idrisi 32. We discarded a number of variables with no statistical significance and avoided multicollinearity by using Spearman rank correlation. Then, we used GLMz (with a multinomial error distribution and a logit link function) to analyse the influence of each variable considered in the dispersal process. Finally, GLMz (with a binomial error distribution and a logit link function) were used a posteriori to differentiate between the effects of the explanatory factors on a particular phase of the dispersal process. Results Our results indicate that proximity to a previously colonized grid significantly affected the global process of roe deer colonization. Independently of the proximity of the nearest population in the previous phase of colonization, our results also indicated that the dispersal process was influenced by precipitation and landscape structure, leading the species to colonize even apparently hostile places. Original nuclei of these populations occurred in territories with high and constant precipitation, and a landscape formed by mosaics of agricultural land with a high proportion of forests. During the expansion process, roe deer colonized territories with summer droughts, dominated by large agricultural patches and with few forest patches. Main conclusions These data support the working hypothesis that environmental characteristics constrain roe deer relative abundance and dispersal process through the Iberian Mountains. The location of the original nuclei of these populations probably had environmental conditions that were more favourable for the roe deer. Areas settled in the final phases of the dispersal process had low relative abundances of roe deer, and are likely to act mainly as dispersal corridors rather than being able to sustain viable populations themselves.