Aerobic training increases the expression of adiponectin receptor genes in the peripheral blood mononuclear cells of young men

Little is known about the effect of exercise training on the expression of adiponectin receptor genes in peripheral blood mononuclear cells (PBMCs). In this study, we investigated the effects of aerobic training on the expression of AdipoR1 and AidpoR2 mRNAs in PBMCs, whole body insulin sensitivity, and circulating adiponectins in men. Thirty young men were randomly assigned to either a control (n=15) or an exercise (n=15) group. Subjects assigned to the exercise group underwent a 12-week jogging and/or running programme on a motor-driven treadmill at an intensity of 60%-75% of the age-based maximum heart rate with duration of 40 minutes per session and a frequency of 5 days per week. Two-way mixed ANOVA with repeated measures was used to test any significant time-by-group interaction effects for the measured variables at p=0.05. We found significant time-by-group interaction effects for waist circumference (p=0.001), VO_2max (p<0.001), fasting insulin (p=0.016), homeostasis model assessment for insulin resistance (HOMA-IR) (p=0.010), area under the curve (AUC) for insulin response during the 75-g oral glucose tolerance test (p=0.002), high-molecular weight (HMW) adiponectin (p=0.016), and the PBMC mRNA levels of AdipoR1 (p<0.001) and AdipoR2 (p=0.001). The exercise group had significantly increased mRNA levels of AdipoR1 and AdipoR2 in PBMCs, along with increased whole body insulin sensitivity and HMW adiponectin, decreased waist circumference, and increased VO_2max compared with the control group. In summary, the current findings suggest that exercise training modulates the expression of AdipoR1 and AdipoR2 mRNAs in PBMCs, implying that manipulation of the expression of these genes could be a potential surrogate for lifestyle intervention-mediated improvements of whole body insulin sensitivity and glucose homeostasis.     

Genetic and environmental heterogeneity of residual variance of weight traits in Nellore beef cattle

Background

Many studies have provided evidence of the existence of genetic heterogeneity of environmental variance, suggesting that it could be exploited to improve robustness and uniformity of livestock by selection. However, little is known about the perspectives of such a selection strategy in beef cattle.

Methods

A two-step approach was applied to study the genetic heterogeneity of residual variance of weight gain from birth to weaning and long-yearling weight in a Nellore beef cattle population. First, an animal model was fitted to the data and second, the influence of additive and environmental effects on the residual variance of these traits was investigated with different models, in which the log squared estimated residuals for each phenotypic record were analyzed using the restricted maximum likelihood method. Monte Carlo simulation was performed to assess the reliability of variance component estimates from the second step and the accuracy of estimated breeding values for residual variation.

Results

The results suggest that both genetic and environmental factors have an effect on the residual variance of weight gain from birth to weaning and long-yearling in Nellore beef cattle and that uniformity of these traits could be improved by selecting for lower residual variance, when considering a large amount of information to predict genetic merit for this criterion. Simulations suggested that using the two-step approach would lead to biased estimates of variance components, such that more adequate methods are needed to study the genetic heterogeneity of residual variance in beef cattle.     

Synthesis and physicochemical properties of two analogs of poly(dA): poly(2-aminopurine-9-beta-D-deoxyribonucleotide) and poly 2-amino-deoxyadenylic acid.

Polymerization of chemically synthesized dn2h6ATP and dn2ATP by deoxynucleotidyl transferase from calf thymus furnished poly(dn2h6A) and poly(dn2A) respectively. The synthetic polynucleotides were characterized by spectroscopic, ultracentrifugation and enzymatic methods. In polynucleotide-polynucleotide interaction, poly(dn2h6A) and poly(dn2A) behaved like analogs of poly(dnA).     

Human palatine tonsil: a new potential tissue source of multipotent mesenchymal progenitor cells

Introduction  

Mesenchymal progenitor cells (MPCs) are multipotent progenitor cells in adult tissues, for example, bone marrow (BM). Current challenges of clinical application of BM-derived MPCs include donor site morbidity and pain as well as low cell yields associated with an age-related decrease in cell number and differentiation potential, underscoring the need to identify alternative sources of MPCs. Recently, MPC sources have diversified; examples include adipose, placenta, umbilicus, trabecular bone, cartilage, and synovial tissue. In the present work, we report the presence of MPCs in human tonsillar tissue.     

Molecular Characterization of Proteolytic Processing of the Gag Proteins of Human Spumavirus

Spumaviruses, or foamy viruses, express Gag proteins that are incompletely processed by the viral protease in cell cultures. To delineate the proteolytic cleavage sites between potential Gag subdomains, recombinant human spumaretrovirus (HSRV) Gag proteins of different lengths were expressed, purified by affinity chromatography, and subjected to HSRV protease assays. HSRV-specific proteolytic cleavage products were isolated and characterized by Western blotting. Peptides spanning potential cleavage sites, as deduced from the sizes of the proteolytic cleavage products, were chemically synthesized and assayed with HSRV protease. The cleaved peptides were then subjected to mass spectrometry. In control experiments, HSRV protease-deficient mutant proteins were used to rule out unspecific processing by nonviral proteases. The cleavage site junctions identified and the calculated sizes of the cleavage products were in agreement with those of the authentic cleavage products of the HSRV Gag proteins detectable in viral proteins from purified HSRV particles and in virus-infected cells. The biological significance of the data was confirmed by mutational analysis of the cleavage sites in a recombinant Gag protein and in the context of the infectious HSRV DNA provirus.     

Ether lipid biosynthesis: isolation and molecular characterization of human dihydroxyacetonephosphate acyltransferase

In this paper we describe isolation and molecular characterization of human dihydroxyacetonephosphate acyltransferase (DAP-AT). The enzyme was extracted from rabbit Harderian gland peroxisomes and isolated as a trimeric complex by sucrose density gradient centrifugation. From peptide sequences matching EST-clones were obtained which allowed cloning and sequencing of the cDNA from a human cDNA library. The nucleotide-derived amino acid sequence revealed a protein consisting of 680 amino acid residues of molecular mass 77 187 containing a C-terminal type 1 peroxisomal targeting signal. Monospecific antibodies raised against this polypeptide efficiently immunoprecipitated DAP-AT activity from solubilized peroxisomal preparations, thus demonstrating that the cloned cDNA codes for DAP-AT.     

Rapid restriction mapping of DNA cloned in lambda phage vectors

A protocol for the rapid restriction mapping of phage λ clones has been developed. Partial digestion products are selectively labelled at the right or left cohesive λ DNA termini by hybridisation with [³²P]oligonucleotides complementary to the single-stranded cos ends. After gel electrophoresis and autoradiography, the restriction map can be directly determined from the “ladder” of partial digestion products.