Stimulus-specific plasticity of prefrontal cortex dopamine neurotransmission

Future planning and behavioral modification is thought to require experience-dependent plasticity in neuronal circuits involving the prefrontal cortex, nucleus accumbens and amygdala. Dopamine has been implicated in such plasticity; however, the nature of the adaptive response of dopamine systems to emotionally salient experiences is poorly understood. We determined whether the dopaminergic response to a given stimulus changes after the first exposure to that stimulus and whether this alteration is stimulus specific. Dopamine release was measured in the prefrontal cortex and the nucleus accumbens in response to two aversive but qualitatively distinct stimuli, physical restraint and electrical microstimulation of basolateral amygdala. In the prefrontal cortex, the first exposure to restraint or amygdala stimulation produced similar increases in dopamine release. The second exposure to restraint resulted in an attenuated response (- 36%) whereas the second exposure to amygdala stimulation produced a potentiated response (+ 110%). Cross-modal potentiation of response occurred with both stimuli. These adaptive changes were specific to the prefrontal cortex and were not observed in the nucleus accumbens. These findings demonstrate that prefrontal cortical dopamine output adapts after a single exposure to stimuli with emotional salience. The direction of this adaptation, however, is not uniform and depends on the nature of the stimulus.     

Following the genes: a framework for animal modeling of psychiatric disorders

Background

The caspase family, which plays a central role in apoptosis in metazoans, has undergone an expansion in amphioxus, increasing to 45 members through domain recombination and shuffling.

Results

In order to shed light on the conservation and uniqueness of this family in amphioxus, we cloned three representative caspase genes, designated as bbtCaspase-8, bbtCaspase-1/2 and bbtCaspase3-like, from the amphioxus Branchiostoma belcheri tsingtauense. We found that bbtCaspase-8 with conserved protein architecture is involved in the Fas-associated death domain-Caspase-8 mediated pro-apoptotic extrinsic pathway, while bbtCaspase3-like may mediate a nuclear apoptotic pathway in amphioxus. Also, bbtCaspase-1/2 can co-localize with bbtFADD2 in the nucleus, and be recruited to the cytoplasm by amphioxus apoptosis associated speck-like proteins containing a caspase recruitment domain, indicating that bbtCaspase-1/2 may serve as a switch between apoptosis and caspase-dependent innate immune response in invertebrates. Finally, amphioxus extrinsic apoptotic pathway related caspases played important roles in early embryogenesis.

Conclusions

Our study not only demonstrates the conservation of bbtCaspase-8 in apoptosis, but also reveals the unique features of several amphioxus caspases with novel domain architectures arose some 500 million years ago.     

Strong binding active constituents of phytochemical to BMPR1A promote bone regeneration: In vitro,in silico docking,and in vivo studies

Two of the most problematic orthopedic and neurosurgeon visits are associated with spine and craniofacial fractures. Therefore, more attention needs to be paid to finding a medicine to repair these fractures. Amongst the most mysterious herbs, Aloe vera stands out. In the present study, the ameliorating function of A. vera on osteogenesis was studied in vitro and in vivo. Osteoblast-like cells were exposed to A. vera, followed by analysis of cell viability, lactate dehydrogenase release, and intracellular reactive oxygen species (ROS) production. The results showed an enhanced cell biocompatibility in a dose-dependent manner due to attenuated intracellular ROS production. Furthermore, a docking study indicated that the strong affinity of A. vera constituents to type I bone morphogenic protein receptor (BMPR1A) without the involvement of the BMPR1A chain B. The induction of osteogenesis prompts extracellular calcium deposition by osteoblasts, which affirms successful in vitro bone regeneration. However, injection of A. vera in rats with critical size calvarial defects induced Runx2, alkaline phosphatase (ALP), OCN, and BMP2 genes overexpression, which led to the formation of victorious bone with enhanced bone density and ALP activity. It is worthy to note that Aloin has the highest affinity to BMPR1A, whereas there are no reports regarding the impact of Aloenin, Aloesin, and γ-sitosterol on osteogenesis. Furthermore, some of them have antitumor potency, and it might be proposed that they are considered as a bone substitute in the osteotomy site of osteosarcoma with the aim of bone recovery and suppression of osteosarcoma. The whole consequences of this investigation manifests the plausibility of using A. vera as an antioxidant and osteoconductive substitute.     

Purification, characterization and thermal inactivation kinetics of a non-regioselective thermostable lipase from a genotypically identified extremophilic Bacillus subtilis NS 8

Thermostable lipase produced by a genotypically identified extremophilic Bacillus subtilis NS 8 was purified 500-fold to homogeneity with a recovery of 16% by ultrafiltration, DEAE-Toyopearl 650M and Sephadex G-75 column. The purified enzyme showed a prominent single band with a molecular weight of 45 kDa. The optimum pH and temperature for activity of lipase were 7.0 and 60°C, respectively. The enzyme was stable in the pH range between 7.0 and 9.0 and temperature range between 40 and 70°C. It showed high stability with half-lives of 273.38 min at 60°C, 51.04 min at 70°C and 41.58 min at 80°C. The D-values at 60, 70 and 80°C were 788.70, 169.59 and 138.15 min, respectively. The enzyme's enthalpy, entropy and Gibb's free energy were in the range of 70.07-70.40 kJ mol(-1), -83.58 to -77.32 kJ mol(-1)K(-1) and 95.60-98.96 kJ mol(-1), respectively. Lipase activity was slightly enhanced when treated with Mg(2+) but there was no significant enhancement or inhibition of the activity with Ca(2+). However, other metal ions markedly inhibited its activity. Of all the natural vegetable oils tested, it had slightly higher hydrolytic activity on soybean oil compared to other oils. On TLC plate, the enzyme showed non-regioselective activity for triolein hydrolysis.     

Specific alterations in complement protein activity of little brown myotis (Myotis lucifugus) hibernating in white-nose syndrome affected sites

White-nose syndrome (WNS) is the most devastating condition ever reported for hibernating bats, causing widespread mortality in the northeastern United States. The syndrome is characterized by cutaneous lesions caused by a recently identified psychrophilic and keratinophylic fungus (Geomyces destructans), depleted fat reserves, atypical behavior, and damage to wings; however, the proximate cause of mortality is still uncertain. To assess relative levels of immunocompetence in bats hibernating in WNS-affected sites compared with levels in unaffected bats, we describe blood plasma complement protein activity in hibernating little brown myotis (Myotis lucifugus) based on microbicidal competence assays using Escherichia coli, Staphylococcus aureus and Candida albicans. Blood plasma from bats collected during mid-hibernation at WNS-affected sites had higher bactericidal ability against E. coli and S. aureus, but lower fungicidal ability against C. albicans when compared with blood plasma from bats collected at unaffected sites. Within affected sites during mid-hibernation, we observed no difference in microbicidal ability between bats displaying obvious fungal infections compared to those without. Bactericidal ability against E. coli decreased significantly as hibernation progressed in bats collected from an affected site. Bactericidal ability against E. coli and fungicidal ability against C. albicans were positively correlated with body mass index (BMI) during late hibernation. We also compared complement activity against the three microbes within individuals and found that the ability of blood plasma from hibernating M. lucifugus to lyse microbial cells differed as follows: E. coli>S. aureus>C. albicans. Overall, bats affected by WNS experience both relatively elevated and reduced innate immune responses depending on the microbe tested, although the cause of observed immunological changes remains unknown. Additionally, considerable trade-offs may exist between energy conservation and immunological responses. Relationships between immune activity and torpor, including associated energy expenditure, are likely critical components in the development of WNS.     

Interaction Between Oxytocin and Opioidergic System on Food Intake Regulation in Neonatal Layer Type Chicken

The aim of the current study was to determine possible interaction of central oxytocin and opioidergic system on food intake regulation in neonatal layer-type chicken. In experiment 1, FD₃ chicken ICV injected with control solution, oxytocin (10 µg), β-FNA (µ receptor antagonist, 5 µg) and oxytocin (10 µg)?+?β-FNA were injected. Experiments 2–6 were similar to experiments 1, except chicken injected with nor-BNI (κ receptor antagonist, 5 µg), NTI (δ receptor antagonist, 5 µg), DAMGO (µ receptor agonist, 62.25 pmol), U-50488H (κ receptor agonist, 10 nmol), DPDPE (δ receptor agonist, 20 pmol) instead of β-FNA. In experiment 7, control solution, DAMGO (125 pmol), d(CH2)5Tyr(Me)-[Orn8]-vasotocin (oxytocin antagonist, 5 µg) and DAMGO?+?d(CH2)5Tyr(Me)-[Orn8]-vasotocin were ICV injected to FD₃ chicken. Experiments 8 and 9 were similar to experiments 7, except chicken injected with U-50488H (30 nmol) and DPDPE (40 pmol) instead of DAMGO. Then, cumulative food intake was recorded at 30, 60 and 120 min after injection. According to the results, ICV injection of the oxytocin (10 µg) significantly decreased food intake compared to control group (P?<?0.05). Co-injection of the oxytocin?+?β-FNA and oxytocin?+?U-50488H significantly decreased hypophagic effect of the oxytocin (P?<?0.05). While, co-injection of the oxytocin?+?nor-BNI or oxytocin?+?DAMGO significantly amplified hypophagic effect of the oxytocin in chicken (P?<?0.05). In addition, ICV injection of DAMGO (125 pmol) significantly decreased cumulative food intake compared to control group (P?<?0.05). However, co-addministration of the DAMGO?+?(CH2)5Tyr(Me)-[Orn8]-vasotocin significantly decreased hypophagic effect of the DAMGO (P?<?0.05) in chicken. These results suggested there are interconnection between oxytocin and opioidergic system on central food intake regulation, which mediates via µ and κ opioidergic receptors in neonatal layer-type chicken.

     

Bone marrow-derived mesenchymal stem cells enhance angiogenesis via their α6β1 integrin receptor

Bone marrow-derived mesenchymal stem cells (BMSCs) facilitate the angiogenic response of endothelial cells (ECs) within three-dimensional (3D) matrices in vivo and in engineered tissues in vitro in part through paracrine mediators and by acting as stabilizing pericytes. However, the molecular interactions between BMSCs and nascent tubules during the process of angiogenesis are not fully understood. In this study, we have used a tractable 3D co-culture model to explore the functional role of the α6β1 integrin adhesion receptor on BMSCs in sprouting angiogenesis. We report that knockdown of the α6 integrin subunit in BMSCs significantly reduces capillary sprouting, and causes their failure to associate with the nascent vessels. Furthermore, we demonstrate that the BMSCs with attenuated α6 integrin proliferate at a significantly lower rate relative to either control cells expressing non-targeting shRNA or wild type BMSCs; however, despite adding more cells to compensate for this deficit in proliferation, deficient sprouting persists. Collectively, our findings demonstrate that the α6 integrin subunit in BMSCs is important for their ability to stimulate vessel morphogenesis. This conclusion may have important implications in the optimization of cell-based strategies to promote angiogenesis.     

Association of the costimulatory molecule gene polymorphisms and active cytomegalovirus infection in hematopoietic stem cell transplant patients

Determinative associations may exist between costimulatory molecule gene polymorphisms with a variety of post hematopoietic stem cell transplantation (HSCT) viral related clinical outcomes especially acute graft versus host disease (aGVHD). Therefore in this study the associations between costimulatory molecule gene polymorphisms including: cytotoxic T-lymphocyte antigen-4 (CTLA4), programmed cell death-1 (PD-1), inducible T cell costimulator (ICOS), and cluster differentiation 28 (CD28) with active cytomegalovirus (CMV) infection were evaluated in HSCT patients. The 72 allogeneic HSCT patients with and without aGVHD were enrolled in this cross sectional study between years: 2004–2011. The single nucleotide polymorphisms in loci of the costimulatory molecules including: CTLA4 gene (?318 C/T, 1722 T/C, 1661 A/G, +49 A/G), PD-1 gene (PD-1.3 A/G, PD-1.9 C/T), ICOS gene (1720 C/T), and CD28 gene (+17 C/T) were analyzed in studied HSCT patients by PCR-RFLP methods. The active CMV infection was evaluated in fresh EDTA-treated blood samples of each allogeneic HSCT patients by CMV antigenemia kit according to manufacturer’s instruction. Active CMV infection was found in 11 of 72 (15.27 %) of allogeneic HSCT patients. The T allele and TT genotype of the CD28 +17 C/T were significantly higher frequency in active CMV infected allogeneic HSCT patients experienced aGVHD. The G allele and GG genotype of the CTLA4 ?1661 A/G were significantly higher frequent in active CMV infected allogeneic HSCT patients experienced low grade of aGVHD. Finally, finding of significant associations between CD28 +17 C/T and CTLA4 ?1661 A/G genotypes with CMV active infection in allogeneic HSCT patients experienced aGVHD emphasize on the importance of the genetic pattern of costimulatory genes in outcomes of active CMV infection in HSCT patients needs completed studies.     

DFT study of HOMO structural map of β-diketones and β-ketoesters; towards prediction of electrochemical oxidation

In this study, anodic oxidation potentials of a training set of the selected 14 β-diketones and β-diketoesters were measured by means of cyclic voltammetry on a glassy carbon electrode and correlated with the highest occupied molecular orbital (HOMO) calculated at the #B3LYP/6-311+G** level. HOMO energy level and HOMO structural map were used to make a powerful model to classify molecules which show similar chemical and electrochemical behaviours. The linear correlation between anodic peak potential, E_pA, and E_HOMO of classified compounds, certifies that they have the same mechanism of the electron transfer reaction.