Decreased frequency of the TNF2 allele of TNF-alpha -308 promoter polymorphism is associated with lacunar infarction

BACKGROUND AND PURPOSE: Enhanced release of proinflammatory cytokines may contribute to the pathogenesis of stroke. It was examined whether G to A promoter polymorphism in the tumor necrosis factor-alpha gene at position -308 affects the risk of stroke. METHODS: We genotyped 336 patients with ischemic stroke and 333 healthy controls for this polymorphism. Patients were divided into different groups based on the Oxfordshire Community Stroke Project (OCSP) or a modified TOAST classification. Distribution of the alleles at -308 G>A promoter polymorphism was determined by PCR-RLFP method. RESULTS: Patients with ischemic stroke had a significantly (p<0.001) decreased (0.115) frequency of the -308 A (TNF2) allele compared to the healthy controls (0.196). When patients were categorized according to the OCSP classification, it turned out that significant (p=0.002) decrease in TNF2 allele frequency (0.065) was restricted to the patients with lacunar infarct (LACI) whereas the frequency of the TNF2 alleles in patients with the other three subtypes (TACI, PACI, and POCI) did not significantly differ from that in healthy controls. Similar results were obtained when the patients were divided according to the modified TOAST classification: the frequencies of the TNF2 allele were 0.068 and 0.140 (p=0.010) in the patients with small-vessel and non-small vessel (large vessel infarction or ischemic stroke of other origin) infarction, respectively. The age-adjusted odds ratio of the patients carrying the TNF2 allele to develop lacunar infarct was 0.33 (0.16-0.68) (p=0.002) compared to the non-carriers. This difference was also restricted to the male patients. CONCLUSIONS: Our results suggest that male carriers of TNF2 allele are less susceptible for the development of lacunar subtype of ischemic stroke than the non-carriers.     

Identifying novel genes involved in both deer physiological and human pathological osteoporosis

Osteoporosis attacks 10% of the population worldwide. Humans or even the model animals of the disease cannot recover from porous bone. Regeneration in skeletal elements is the unique feature of our newly investigated osteoporosis model, the red deer (Cervus elaphus) stag. Cyclic physiological osteoporosis is a consequence of the annual antler cycle. This phenomenon raises the possibility to identify genes involved in the regulation of bone mineral density on the basis of comparative genomics between deer and human. We compare gene expression activity of osteoporotic and regenerating rib bone samples versus autumn dwell control in red deer by microarray hybridization. Identified genes were tested on human femoral bone tissue from non-osteoporotic controls and patients affected with age-related osteoporosis. Expression data were evaluated by Principal Components Analysis and Canonical Variates Analysis. Separation of patients into a normal and an affected group based on ten formerly known osteoporosis reference genes was significantly improved by expanding the data with newly identified genes. These genes include IGSF4, FABP3, FABP4, FKBP2, TIMP2, TMSB4X, TRIB, and members of the Wnt signaling. This study supports that extensive comparative genomic analyses, here deer and human, provide a novel approach to identify new targets for human diagnostics and therapy. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Differential Changes in Expression of Stress- and Metabolic-Related Neuropeptides in the Rat Hypothalamus during Morphine Dependence and Withdrawal

Chronic morphine treatment and naloxone precipitated morphine withdrawal activates stress-related brain circuit and results in significant changes in food intake, body weight gain and energy metabolism. The present study aimed to reveal hypothalamic mechanisms underlying these effects. Adult male rats were made dependent on morphine by subcutaneous implantation of constant release drug pellets. Pair feeding revealed significantly smaller weight loss of morphine treated rats compared to placebo implanted animals whose food consumption was limited to that eaten by morphine implanted pairs. These results suggest reduced energy expenditure of morphine-treated animals. Chronic morphine exposure or pair feeding did not significantly affect hypothalamic expression of selected stress- and metabolic related neuropeptides - corticotropin-releasing hormone (CRH), urocortin 2 (UCN2) and proopiomelanocortin (POMC) compared to placebo implanted and pair fed animals. Naloxone precipitated morphine withdrawal resulted in a dramatic weight loss starting as early as 15–30 min after naloxone injection and increased adrenocorticotrophic hormone, prolactin and corticosterone plasma levels in morphine dependent rats. Using real-time quantitative PCR to monitor the time course of relative expression of neuropeptide mRNAs in the hypothalamus we found elevated CRH and UCN2 mRNA and dramatically reduced POMC expression. Neuropeptide Y (NPY) and arginine vasopressin (AVP) mRNA levels were transiently increased during opiate withdrawal. These data highlight that morphine withdrawal differentially affects expression of stress- and metabolic-related neuropeptides in the rat hypothalamus, while relative mRNA levels of these neuropeptides remain unchanged either in rats chronically treated with morphine or in their pair-fed controls.     

Activated leukocyte cell adhesion molecule modulates neurotrophin signaling

Cell adhesion molecules of the immunoglobulin superfamily (IgCAMs) have been shown to modulate growth factor signaling and follow complex trafficking pathways in neurons. Similarly, several growth factors, including members of the neurotrophin family, undergo axonal retrograde transport that is required to elicit their full signaling potential in neurons. We sought to determine whether IgCAMs that enter the axonal retrograde transport route co-operate with neurotrophin signaling. We identified activated leukocyte cell adhesion molecule (ALCAM), a protein involved in axon pathfinding and development of the neuromuscular junction, to be associated with an axonal endocytic compartment that contains neurotrophins and their receptors. Although ALCAM enters carriers that are transported bidirectionally in motor neuron axons, it is predominantly co-transported with the neurotrophin receptor p75(NTR) toward the cell body. ALCAM was found to specifically potentiate nerve growth factor (NGF)-induced differentiation and signaling. The extracellular domain of ALCAM is both necessary and sufficient to potentiate NGF-induced neurite outgrowth, and its homodimerization is required for this novel role. Our findings indicate that ALCAM synergizes with NGF to induce neuronal differentiation, raising the possibility that it functions not only as an adhesion molecule but also in the modulation of growth factor signaling in the nervous system.     

Post-transplant diabetes mellitus - risk factors and effects on the function and morphology of the allograft

The incidence of post-transplant diabetes mellitus and its effects on the kidney allograft function and morphology were assessed. Patients were divided into three groups according to their glucose metabolism. Risk factors for diabetes were first assessed, and then changes in renal function were checked. Morphological changes in the allografts were examined by protocol biopsies. The overall incidence of diabetes was 16%. The development of diabetes was influenced significantly by the body mass index, the body weight and the age of the recipient. The incidence of diabetes was 8.6% in patients on cyclosporine A therapy and 28.8% in those on tacrolimus (p < 0.05). As to the morphology of the kidney, a significantly higher proportion of the biopsies showed severe interstitial fibrosis/tubular atrophy (p = 0.0004) and subclinical acute rejection ( p = 0.001) in the diabetic group compared to the normal one. This clinical study has revealed that the adverse effect of diabetes on the allograft can be detected with protocol biopsy before the manifestation of a functional deterioration.     

On risks and benefits of iron supplementation recommendations for iron intake revisited

Iron is an essential trace element with a high prevalence of deficiency in infants and in women of reproductive age from developing countries. Iron deficiency is frequently associated with anaemia and, thus, with reduced working capacity and impaired intellectual development. Moreover, the risk for premature delivery, stillbirth and impaired host-defence is increased in iron deficiency. Iron-absorption and -distribution are homeostatically regulated to reduce the risk for deficiency and overload. These mechanisms interact, in part, with the mechanisms of oxidative stress and inflammation and with iron availability to pathogens. In the plasma, fractions of iron may not be bound to transferrin and are hypothesised to participate in atherogenesis. Repleted iron stores and preceding high iron intakes reduce intestinal iron absorption which, however, offers no reliable protection against oral iron overload. Recommendations for dietary iron intake at different life stages are given by the US Food and Nutrition Board (FNB), by FAO/WHO and by the EU Scientific Committee, among others. They are based, on estimates for iron-losses, iron-bioavailability from the diet, and iron-requirements for metabolism and growth. Differences in choice and interpretation of these estimates lead to different recommendations by the different panels which are discussed in detail. Assessment of iron-related risks is based on reports of adverse health effects which were used in the attempts to derive an upper safe level for dietary iron intake. Iron-related harm can be due to direct intestinal damage, to oxidative stress, or to stimulated growth of pathogens. Unfortunately, it is problematic to derive a reproducible cause-effect and dose-response relationship for adverse health effects that suggest a relationship to iron-intake, be they based on mechanistic or epidemiological observations. Corresponding data and interpretations are discussed for the intestinal lumen, the vascular system and for the intracellular and interstitial space, considering interference of the mechanisms of iron homoeostasis as a likely explanation for differences in epidemiological observations.     

Rapid solid-phase synthesis of a calmodulin-binding peptide using controlled microwave irradiation

A rapid and efficient microwave-assisted solid-phase synthesis method for the preparation of a nonapeptide using conventional Fmoc/Bu(t) orthogonal protection strategy is described. In this protocol, the coupling steps are performed within 5 min at 60 degrees C and the Fmoc-deprotection steps are completed within 3 min at 60 degrees C using a dedicated single-mode microwave peptide synthesizer utilizing temperature-controlled conditions. It is demonstrated that the model nonapeptide (containing the calmodulin-binding octapeptide sequence) is synthesized in a shorter time (approximately 3.5 h) and with high purity (>95%) under microwave irradiation conditions in comparison with a reference peptide that is obtained by standard methods at room temperature (within 11 h).