p8/nupr1 regulates DNA‐repair activity after double‐strand gamma irradiation‐induced DNA damage

The stress protein p8 is a small, highly basic, unfolded, and multifunctional protein. We have previously shown that most of its functions are exerted through interactions with other proteins, whose activities are thereby enhanced or repressed. In this work we describe another example of such mechanism, by which p8 binds and negatively regulates MSL1, a histone acetyl transferase (HAT)‐associated protein, which in turn binds the DNA‐damage‐associated 53BP1 protein to facilitate DNA repair following DNA γ‐irradiation. Contrary to the HAT‐associated activity, MSL1‐dependent DNA‐repair activity is almost completely dependent on 53BP1 expression. The picture that has emerged from our findings is that 53BP1 could be a scaffold that gets the HAT MSL1‐dependent DNA‐repair activity to the sites of DNA damage. Finally, we also found that, although p8 expression is transiently activated after γ‐irradiation, it is eventually submitted to sustained down‐regulation, presumably to allow development of MSL1‐associated DNA‐repair activity. We conclude that interaction of MSL1 with 53BP1 brings MSL1‐dependent HAT activity to the vicinity of damaged DNA. MSL1‐dependent HAT activity, which is negatively regulated by the stress protein p8, induces chromatin remodeling and relaxation allowing access to DNA of the repair machinery. J. Cell. Physiol. 221: 594–602, 2009. © 2009 Wiley‐Liss, Inc.     

Long-Term Behavioral Programming Induced by Peripuberty Stress in Rats Is Accompanied by GABAergic-Related Alterations in the Amygdala

Stress during childhood and adolescence is a risk factor for psychopathology. Alterations in γ-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the brain, have been found following stress exposure and fear experiences and are often implicated in anxiety and mood disorders. Abnormal amygdala functioning has also been detected following stress exposure and is also implicated in anxiety and social disorders. However, the amygdala is not a unitary structure; it includes several nuclei with different functions and little is known on the potential differences the impact of early life stress may have on this system within different amygdaloid nuclei. We aimed here to evaluate potential regional differences in the expression of GABAergic-related markers across several amygdaloid nuclei in adult rats subjected to a peripuberty stress protocol that leads to enhanced basal amygdala activity and psychopathological behaviors. More specifically, we investigated the protein expression levels of glutamic acid decarboxylase (GAD; the principal synthesizing enzyme of GABA) and of GABA-A receptor subunits α2 and α3. We found reduced GAD and GABA-A α3, but not α2, subunit protein levels throughout all the amygdala nuclei examined (lateral, basolateral, basomedial, medial and central) and increased anxiety-like behaviors and reduced sociability in peripubertally stressed animals. Our results identify an enduring inhibition of the GABAergic system across the amygdala following exposure to early adversity. They also highlight the suitability of the peripuberty stress model to investigate the link between treatments targeting the dysfunctional GABAergic system in specific amygdala nuclei and recovery of specific stress-induced behavioral dysfunctions.     

Direct Comparison of the Efficacy and Safety of Oral Treatments with Oleylphosphocholine (OlPC) and Miltefosine in a Mouse Model of L. major Cutaneous Leishmaniasis

Background

Cutaneous leishmaniasis (CL) represents a range of skin diseases caused by infection with Leishmania parasites and associated with tissue inflammation and skin ulceration. CL is clinically widespread in both the Old and New World but lacks treatments that are well tolerated, effective and inexpensive. Oleylphosphocholine (OlPC) is a new orally bioavailable drug of the alkylphosphocholine family with potent antileishmanial activity against a broad range of Leishmania species/strains.

Methodology/principal findings

The potential of OlPC against Old World CL was evaluated in a mouse model of Leishmania (L.) major infection in BALB/c mice. Initial dose-response experiments showed that an oral daily dose of 40 mg/kg of OlPC was needed to impact time to cure and lesion sizes. This dose was then used to directly compare the efficacy of OlPC to the efficacy of the antileishmanial drugs miltefosine (40 mg/kg/day), fluconazole (160 mg/kg/day) and amphotericin B (25 mg/kg/day). OlPC, miltefosine and fluconazole were given orally for 21 days while amphotericin B was administered intraperitoneally for 10 days. Ulcer sizes and animal weights were followed up on a weekly basis and parasitemia was determined by means of a real-time in vivo imaging system which detects luminescence emitted from luciferase-expressing infecting L. major parasites. Amphotericin B and OlPC showed excellent efficacy against L. major lesions in terms of reduction of parasitic loads and by inducing complete healing of established lesions. In contrast, treatment with miltefosine did not significantly affect parasitemia and lesion sizes, while fluconazole was completely ineffective at the dose regimen tested.

Conclusions/Significance

Given the data showing the outstanding efficacy and tolerability of OlPC, our results suggest that OlPC is a promising new drug candidate to improve and simplify current clinical management of L. major CL.     

Capillary electrophoresis of subcellular-sized particles

Utilization of capillary electrophoresis (CE) for characterization and analytical separation of submicron- and micron-sized organic and inorganic particles as well as biological vesicles is reviewed. CE has been applied to charged polystyrene size standards, inorganic and organic colloidal particles, lipoprotein particles, liposomes, microsomes and viruses. These particle separations generally occur in a size-dependent manner and provide values of electrophoretic mobility which are in good agreement with those obtained by other electrophoretic techniques.     

Effect of restricted watering and its combination with root pruning on root growth capacity,water status and food reserves ofPinus caribaea var.hondurensis seedlings

Summary Six-month oldPinus caribaea var.hondurensis seedling were subjected to various regimes of restricted watering and their combinations with root pruning to determine a suitable technique of producing seedlings with optimum physiological condition for successful bare-root planting.From the range of treatments tested, plants subjected to watering once every 9 days (D9) were found to be the hardest in terms of highest root growth capacity, leaf water content, root starch content and in having a moderately low transpiration rate.P. caribaea seedlings subjected to this preconditioning treatment may be more able to survive bare-root planting.     

Adaptations of microbial communities and dissolved organics to seasonal pressures in a mesotrophic coastal Mediterranean lake

In lake ecosystems, changes in eukaryotic and prokaryotic microbes and the concentration and availability of dissolved organic matter (DOM) produced within or supplied to the system by allochthonous sources are components that characterize complex processes in the microbial loop. We address seasonal changes of microbial communities and DOM in the largest Croatian lake, Vrana. This shallow lake is connected to the Adriatic Sea and is impacted by agricultural activity. Microbial community and DOM structure were driven by several environmental stressors, including drought, seawater intrusion and heavy precipitation events. Bacterial composition of different lifestyles (free-living and particle-associated) differed and only a part of the particle-associated bacteria correlated with microbial eukaryotes. Oscillations of cyanobacterial relative abundance along with chlorophyll a revealed a high primary production season characterized by increased levels of autochthonous DOM that promoted bacterial processes of organic matter degradation. From our results, we infer that in coastal freshwater lakes dependent on precipitation-evaporation balance, prolonged dry season coupled with heavy irrigation impact microbial communities at different trophic levels even if salinity increases only slightly and allochthonous DOM inputs decrease. These pressures, if applied more frequently or at higher concentrations, could have the potential to overturn the trophic state of the lake.     

Novel 5-Alkylcarboxamide-2'-Deoxyuridine-5'-Triphosphates for Enzymatic Synthesis of Highly Modified DNA

Russian Journal of Bioorganic Chemistry - The synthesis of deoxyuridine triphosphate derivatives with alkyl groups of various chain length attached to the pyrimidine base by the trans-alkene linker...     

ADRA2A is involved in neuro‐endocrine regulation of bone resorption

Adrenergic stimulation is important for osteoclast differentiation and bone resorption. Previous research shows that this happens through β2‐adrenergic receptor (AR), but there are conflicting evidence on presence and role of α2A‐AR in bone. The aim of this study was to investigate the presence of α2A‐AR and its involvement in neuro‐endocrine signalling of bone remodelling in humans. Real‐time polymerase chain reaction (PCR) and immunohistochemistry were used to investigate α2A‐AR receptor presence and localization in bone cells. Functionality of rs553668 and rs1800544 single nucleotide polymorphism SNPs located in α2A‐AR gene was analysed by qPCR expression on bone samples and luciferase reporter assay in human osteosarcoma HOS cells. Using real‐time PCR, genetic association study between rs553668 A>G and rs1800544 C>G SNPs and major bone markers was performed on 661 Slovenian patients with osteoporosis. α2A‐AR is expressed in osteoblasts and lining cells but not in osteocytes. SNP rs553668 has a significant influence on α2A‐AR mRNA level in human bone samples through the stability of mRNA. α2A‐AR gene locus associates with important bone remodelling markers (BMD, CTX, Cathepsin K and pOC). The results of this study are providing comprehensive new evidence that α2A‐AR is involved in neuro‐endocrine signalling of bone turnover and development of osteoporosis. As shown by our results the neurological signalling is mediated through osteoblasts and result in bone resorption. Genetic study showed association of SNPs in α2A‐AR gene locus with bone remodelling markers, identifying the individuals with higher risk of development of osteoporosis.