Synthesis of a metallopeptide-PNA conjugate and its oxidative cross-linking to a DNA target

A nickel(II)-PNA bioconjugate was prepared by formation of a salicylaldimine complex with the amino terminus of a peptide-PNA hybrid with the sequence Arg-His-Gly-[TACCTAGCAT]PNA-Arg-CONH2. Hybridization to complementary oligodeoxynucleotides was demonstrated, and covalent adduct formation was observed upon addition of KHSO5 as oxidant. In the absence of PNA, the reactivity of the phenolic radical generated as an intermediate was found to be G > T > C, A; by inclusion of the PNA delivery agent, cross-links between the two oligomers could be observed with T and C bases in the vicinity of the nickel complex, although G was still the most reactive site. The metal complex could be removed by treatment with EDTA following which the Schiff base linkage was readily hydrolyzed. The final result in this case is a salicylaldehyde moiety appended at the target site in DNA.     

Heat shock protein 10 inhibits lipopolysaccharide-induced inflammatory mediator production

Heat shock protein 10 (Hsp10) and heat shock protein 60 (Hsp60) were originally described as essential mitochondrial proteins involved in protein folding. However, both proteins have also been shown to have a number of extracellular immunomodulatory activities. Here we show that purified recombinant human Hsp10 incubated with cells in vitro reduced lipopolysaccharide (LPS)-induced nuclear factor-kappaB activation and secretion of several inflammatory mediators from RAW264.7 cells, murine macrophages, and human peripheral blood mononuclear cells. Induction of tolerance by contaminating LPS was formally excluded as being responsible for Hsp10 activity. Treatment of mice with Hsp10 before endotoxin challenge resulted in the reduction of serum tumor necrosis factor-alpha and RANTES (regulated upon activation, normal T cell expressed and secreted) levels and an elevation of serum interleukin-10 levels. Hsp10 treatment also delayed mortality in a murine graft-versus-host disease model, where gut-derived LPS contributes to pathology. We were unable to confirm previous reports that Hsp10 has tumor growth factor properties and suggest that Hsp10 exerts anti-inflammatory activity by inhibiting Toll-like receptor signaling possibly by interacting with extracellular Hsp60.     

Glycosaminoglycans Are Interactants of Langerin: Comparison with gp120 Highlights an Unexpected Calcium-Independent Binding Mode

Langerin is a C-type lectin specifically expressed in Langerhans cells. As recently shown for HIV, Langerin is thought to capture pathogens and mediate their internalisation into Birbeck Granules for elimination. However, the precise functions of Langerin remain elusive, mostly because of the lack of information on its binding properties and physiological ligands. Based on recent reports that Langerin binds to sulfated sugars, we conducted here a comparative analysis of Langerin interaction with mannose-rich HIV glycoprotein gp120 and glycosaminoglycan (GAGs), a family of sulfated polysaccharides expressed at the surface of most mammalian cells. Our results first revealed that Langerin bound to these different glycans through very distinct mechanisms and led to the identification of a novel, GAG-specific binding mode within Langerin. In contrast to the canonical lectin domain, this new binding site showed no Ca²⁺-dependency, and could only be detected in entire, trimeric extracellular domains of Langerin. Interestingly binding to GAGs, did not simply rely on a net charge effect, but rather on more discrete saccharide features, such as 6-O-sulfation, or iduronic acid content. Using molecular modelling simulations, we proposed a model of Langerin/heparin complex, which located the GAG binding site at the interface of two of the three Carbohydrate-recognition domains of the protein, at the edge of the a-helix coiled-coil. To our knowledge, the binding properties that we have highlighted here for Langerin, have never been reported for C-type lectins before. These findings provide new insights towards the understanding of Langerin biological functions.     

Health Factors and Risk of All-Cause,Cardiovascular, and Coronary Heart Disease Mortality: Findings from the MONICA and HAPIEE Studies in Lithuania

Aims

This study investigated the trends and levels of the prevalence of health factors, and the association of all-cause and cardiovascular (CVD) mortality with healthy levels of combined risk factors among Lithuanian urban population.

Methods

Data from five general population surveys in Kaunas, Lithuania, conducted between 1983 and 2008 were used. Healthy factors measured at baseline include non-smoking, normal weight, normal arterial blood pressure, normal level of total serum cholesterol, normal physical activity and normal level of fasting glucose. Among 9,209 men and women aged 45–64 (7,648 were free from coronary heart disease (CHD) and stroke at baseline), 1,219 death cases from any cause, 589 deaths from CVD, and 342 deaths from CHD occurred during follow up. Cox proportional hazards regression was used to estimate the association between health factors and mortality from all causes, CVD and CHD.

Results

Between 1983 and 2008, the proportion of subjects with 6 healthy levels of risk factors was higher in 2006–2008 than in 1983–1984 (0.6% vs. 0.2%; p = 0.09), although there was a significant increase in fasting glucose and a decline in intermediate physical activity. Men and women with normal or intermediate levels of risk factors had significantly lower all-cause, CVD and CHD mortality risk than persons with high levels of risk factors. Subjects with 5–6 healthy factors had hazard ratio (HR) of CVD mortality 0.35 (95% confidence interval (CI) 0.15–0.83) compared to average risk in the whole population. The hazard ratio for CVD mortality risk was significant in men (HR 0.34, 95% CI 0.12–0.97) but not in women (HR 0.38, 95% CI 0.09–1.67).

Conclusions

An inverse association of most healthy levels of cardiovascular risk factors with risk of all-cause and CVD mortality was observed in this urban population-based cohort. A greater number of cardiovascular health factors were related with significantly lower risk of CVD mortality, particularly among men.     

Effect of wearing a dorsiflexion assist orthosis on mobility, perceived fatigue and exertion during the six-minute walk test in people with multiple sclerosis: a randomised cross-over protocol

ABSTRACT: BACKGROUND: Fatigue in combination with gait and balance impairments can severely limit daily activities in people with multiple sclerosis (PWMS). Generalised fatigue has a major impact on walking ability, with moderately disabled PWMS experiencing difficulty in walking extended distances. Localised motor fatigue in the ankle dorsiflexors can lead to foot drop, further reducing functional ambulation. The aim of this study is to evaluate the effect of a simple dynamic dorsiflexion assist orthosis on walking-induced fatigue, gait, balance and functional mobility in PWMS. METHODS: A randomised cross-over trial will be conducted with 40 community dwelling PWMS with mild to moderate mobility disability. Participants will initially be screened for disease severity, balance, strength, depression and fatigue at the South Australian Motion Analysis Centre. On two non-consecutive occasions, within two weeks, participants will undergo either the 6-minute walk test (6MWT) or the 6MWT while wearing a dorsiflexion ankle orthosis (with a randomised condition order). Distance walked, perceived exertion, perceived fatigue and the physiological cost of walking (the primary outcome measures) will be compared between the two walking conditions. Additional pre- and post-6MWT assessments for the two conditions will include tests of strength, reaction time, gait and balance. DISCUSSION: This study will increase our understanding of motor fatigue on gait and balance control inPWMS and elucidate the effect of a Dynamic Ankle Orthosis on fatigue-related balance and gait in PWMS. It will also examine relationships between mobility and balance performance with perceived fatigue levels in this group. Trial Registration Number ACTRN12612000218897.