HMGA2 expression in white adipose tissue linking cellular senescence with diabetes

There is a clear link between overweight, gain of white adipose tissue, and diabetes type 2 (T2D). The molecular mechanism of the gain of adipose tissue is linked with the expression of high mobility group protein AT-hook 2 (HMGA2), and recent studies revealed an association with a SNP near HMGA2. In this study, we investigated the gene expression of HMGA2, p14^Arf, CDKN1A, and BAX in human abdominal subcutaneous white adipose tissue from 157 patients. We found a significant higher HMGA2 expression in obese individuals than in non-obese patients. Furthermore, the HMGA2 expression in white adipose tissue in patient with type 2 diabetes was significantly higher than in nondiabetic patients. There is an association between the DNA-binding nonhistone protein HMGA2 and the risk of developing T2D that remains mechanistically unexplained so far. Likewise, p14^Arf, an inducer of cellular senescence, has been associated with the occurrence of T2D. The data of the present study provide evidence that both proteins act within the same network to drive proliferation of adipose tissue stem and precursor cells, senescence, and increased risk of T2D, respectively.

Electronic supplementary material

The online version of this article (doi:10.1007/s12263-013-0354-6) contains supplementary material, which is available to authorized users.     

Synthesis and Application of Isosteric Purine 2′-Deoxyribofuranosides

Abstract

The diastereoselective synthesis of several pyrrolo[2,3-d]- and pyrazolo[3,4-d]pyrimidine 2′-deoxy-ribofuranosides employing l-chloro-2-deoxy-3,5-di-0-(p-tolu-oyl)-a-D-erythropentofuranose and the nucleobase anion, generated by liquid-liquid or solid-liquid phase-transfer catalysis, is described. Appropriately protected phosphoramidites of 8-aza-7-deaza-2′-deoxyadenosine and 2′-deoxytubercidin were prepared and employed in solid-phase synthesis of palindromic DNA-fragments. The replacement of dA residues by deoxytubercidin within the Eco RI recognition site d(GAATTC) of the dodecamer d(GTAGAATTCTAC) gave evidence for purine N-7 binding to the endodeoxyribonuclease. The interpretation of similar experiments carried out on d(CGCGAATTCGCG) was obscured because of hairpin formation.     

A Ubiquitin-specific Protease Possesses a Decisive Role for Adenovirus Replication and Oncogene-mediated Transformation

Adenoviral replication depends on viral as well as cellular proteins. However, little is known about cellular proteins promoting adenoviral replication. In our screens to identify such proteins, we discovered a cellular component of the ubiquitin proteasome pathway interacting with the central regulator of adenoviral replication. Our binding assays mapped a specific interaction between the N-terminal domains of both viral E1B-55K and USP7, a deubiquitinating enzyme. RNA interference-mediated downregulation of USP7 severely reduced E1B-55K protein levels, but more importantly negatively affected adenoviral replication. We also succeeded in resynthesizing an inhibitor of USP7, which like the knockdown background reduced adenoviral replication. Further assays revealed that not only adenoviral growth, but also adenoviral oncogene-driven cellular transformation relies on the functions of USP7. Our data provide insights into an intricate mechanistic pathway usurped by an adenovirus to promote its replication and oncogenic functions, and at the same time open up possibilities for new antiviral strategies.     

Inhibition of inducible nitric oxide synthase lowers the cochlear damage by lipopolysaccharide in guinea pigs

Endotoxin-treated cochleas of the guinea pig were examined electrophysiologically and immunohistochemically concerning the expression of inducible nitric oxide synthase (iNOS/NOS II). One mg of bacterial lipopolysaccharide (LPS, 5 mg/ml) or mixed solution of 1 mg of LPS plus 1 mg of N^G-nitro-L-arginine methyl ester (L-NAME, 5 mg/ml) (L-NAME/LPS) was injected into the middle ear of guinea pigs transtympanically. The electrocochleograms were measured prior to, immediately and 48 h after the injection. Immunohistological studies for iNOS followed after fixation, embedding and sectioning of the temporal bones.

The threshold and amplitude of the compound action potential (CAP) became significantly worse in the LPS treated group. In contrast, the changes of the threshold and amplitude of CAP were decreased in the L-NAME/LPS group. iNOS was expressed in the stria vascularis, the spiral ligament, the organ of Corti and the spiral ganglion in the LPS group. These immunore-activities in the L-NAME/LPS group were less intense than that in the LPS group. These results indicate that LPS has an ototoxic effect on the cochlea and that this effect could be mediated by iNOS produced high nitric oxide under inflammatory conditions.     

Effects of Winter Ticks and Internal Parasites on Moose Survival in Vermont,USA

Moose (Alces alces) have experienced considerable declines along the periphery of their range in the northeastern United States. In Vermont, the population declined 45% from 2010 to 2017 despite minimal hunter harvest and adequate habitat. Similarly, nearby populations recently experienced epizootics characterized by >50% mortality. Declines have largely been associated with the effects of winter ticks (Dermacentor albipictus), but uncertainty exists about the effects of environmental and other parasite-related conditions on moose survival. We examined patterns of moose survival among a radio-collared population (n = 127) in Vermont from 2017 to 2019. Our objectives were to estimate causes of mortality and model survival probability as a function of individual and landscape variables for calves (<1 yr) and adults (≥1 yr). Observed adult survival was 90% in 2017, 84% in 2018, and 86% in 2019, and winter calf survival was 60% in 2017, 50% in 2018, and 37% in 2019. Winter tick infestation was the primary cause of mortality (91% of calves, 25% of adults), and 32% of all mortalities had evidence of meningeal worm (Parelaphostrongylus tenuis). Other sources of mortality such as vehicles, harvest, predation, deep snow, and other parasitic infections were negligible. The best supported calf model included sex differences and negative effects of tick engorgement (%/week) and parasite level (roundworm and lungworm). The best supported adult model included the effect of cumulative tick engorgement (cumulative %/week), which negatively affected survival. Our results indicate that winter tick engorgement strongly affects survival, and is probably compounded by the presence of meningeal worm and other parasites. Reduced tick effects may be achieved by decreasing moose density through harvest and managing late winter habitat to minimize tick density. Management of white-tailed deer (Odocoileus virginianus) density may also affect the transmission of meningeal worm. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.     

Rapid,reliable, and reproducible cell fusion assay to quantify SARS-Cov-2 spike interaction with hACE2

COVID-19 is a global crisis of unimagined dimensions. Currently, Remedesivir is only fully licensed FDA therapeutic. A major target of the vaccine effort is the SARS-CoV-2 spike-hACE2 interaction, and assessment of efficacy relies on time consuming neutralization assay. Here, we developed a cell fusion assay based upon spike-hACE2 interaction. The system was tested by transient co-transfection of 293T cells, which demonstrated good correlation with standard spike pseudotyping for inhibition by sera and biologics. Then established stable cell lines were very well behaved and gave even better correlation with pseudotyping results, after a short, overnight co-incubation. Results with the stable cell fusion assay also correlated well with those of a live virus assay. In summary we have established a rapid, reliable, and reproducible cell fusion assay that will serve to complement the other neutralization assays currently in use, is easy to implement in most laboratories, and may serve as the basis for high throughput screens to identify inhibitors of SARS-CoV-2 virus-cell binding and entry.     

Burkavidin: a novel secreted biotin-binding protein from the human pathogen Burkholderia pseudomallei

The avidin-biotin technology has many applications, including molecular detection; immobilization; protein purification; construction of supramolecular assemblies and artificial metalloenzymes. Here we present the recombinant expression of novel biotin-binding proteins from bacteria and the purification and characterization of a secreted burkavidin from the human pathogen Burkholderia pseudomallei. Expression of the native burkavidin in Escherichia coli led to periplasmic secretion and formation of a biotin-binding, thermostable, tetrameric protein containing an intra-monomeric disulphide bond. Burkavidin showed one main species as measured by isoelectric focusing, with lower isoelectric point (pI) than streptavidin. To exemplify the potential use of burkavidin in biotechnology, an artificial metalloenzyme was generated using this novel protein-scaffold and shown to exhibit enantioselectivity in a rhodium-catalysed hydrogenation reaction.