Influence of a Physiologically Formed Blood Clot on Pre-Osteoblastic Cells Grown on a BMP-7-Coated Nanoporous Titanium Surface

Titanium (Ti) nanotopography modulates the osteogenic response to exogenous bone morphogenetic protein 7 (BMP-7) in vitro, supporting enhanced alkaline phosphatase mRNA expression and activity, as well as higher osteopontin (OPN) mRNA and protein levels. As the biological effects of OPN protein are modulated by its proteolytic cleavage by serum proteases, this in vitro study evaluated the effects on osteogenic cells in the presence of a physiological blood clot previously formed on a BMP-7-coated nanostructured Ti surface obtained by chemical etching (Nano-Ti). Pre-osteoblastic MC3T3-E1 cells were cultured during 5 days on recombinant mouse (rm) BMP-7-coated Nano-Ti after it was implanted in adult female C57BI/6 mouse dorsal dermal tissue for 18 h. Nano-Ti without blood clot or with blood clot at time 0 were used as the controls. The presence of blood clots tended to inhibit the expression of key osteoblast markers, except for Opn, and rmBMP-7 functionalization resulted in a tendency towards relatively greater osteoblastic differentiation, which was corroborated by runt-related transcription factor 2 (RUNX2) amounts. Undetectable levels of OPN and phosphorylated suppressor of mothers against decapentaplegic (SMAD) 1/5/9 were noted in these groups, and the cleaved form of OPN was only detected in the blood clot immediately prior to cell plating. In conclusion, the strategy to mimic in vitro the initial interfacial in vivo events by forming a blood clot on a Ti nanoporous surface resulted in the inhibition of pre-osteoblastic differentiation, which was minimally reverted with an rmBMP-7 coating

Effects of rmBMP-7 on Osteoblastic Cells Grown on a Nanostructured Titanium Surface

This study evaluates the effects of the availability of exogenous BMP-7 on osteoblastic cells’ differentiation on a nanotextured Ti surface obtained by chemical etching (Nano-Ti). The MC3T3-E1 and UMR-106 osteoblastic cell lines were cultured for 5 and 7 days, respectively, on a Nano-Ti surface and on a control surface (Control-Ti) in an osteogenic medium supplemented with either 40 or 200 ng/mL recombinant mouse (rm) BMP-7. The results showed that MC3T3-E1 cells exhibited distinct responsiveness when exposed to each of the two rmBMP-7 concentrations, irrespective of the surface. Even with 40 ng/mL rmBMP-7, important osteogenic effects were noticed for Control-Ti in terms of cell proliferation potential; Runx2, Osx, Alp, Bsp, Opn, and Smad1 mRNA expression; and in situ ALP activity. For Nano-Ti, the effects were limited to higher Alp, Bsp, and Opn mRNA expression and in situ ALP activity. On both surfaces, the osteogenic potential of UMR-106 cultures remained unaltered with 40 ng/mL rmBMP-7, but it was significantly reduced when the cultures were exposed to the 200 ng/mL concentration. The availability of rmBMP-7 to pre-osteoblastic cells at the concentrations used alters the expression profile of osteoblast markers, indicative of the acquisition of a more advanced stage of osteoblastic differentiation. This occurs less pronouncedly on the nanotextured Ti and without reflecting in higher mineralized matrix production by differentiated osteoblasts on both surfaces

Cannabis affects people differently: inter-subject variation in the psychotogenic effects of Δ9-tetrahydrocannabinol: a functional magnetic resonance imaging study with healthy volunteers

Background Cannabis can induce transient psychotic symptoms, but not all users experience these adverse effects. We compared the neural response to Δ9-tetrahydrocannabinol (THC) in healthy volunteers in whom the drug did or did not induce acute psychotic symptoms. Method In a double-blind, placebo-controlled, pseudorandomized design, 21 healthy men with minimal experience of cannabis were given either 10mg THC or placebo, orally. Behavioural and functional magnetic resonance imaging measures were then recorded whilst they performed a go/no-go task. Results The sample was subdivided on the basis of the Positive and Negative Syndrome Scale positive score following administration of THC into transiently psychotic (TP; n=11) and non-psychotic (NP; n=10) groups. During the THC condition, TP subjects made more frequent inhibition errors than the NP group and showed differential activation relative to the NP group in the left parahippocampal gyrus, the left and right middle temporal gyri and in the right cerebellum. In these regions, THC had opposite effects on activation relative to placebo in the two groups. The TP group also showed less activation than the NP group in the right middle temporal gyrus and cerebellum, independent of the effects of THC. Conclusions In this first demonstration of inter-subject variability in sensitivity to the psychotogenic effects of THC, we found that the presence of acute psychotic symptoms was associated with a differential effect of THC on activation in the ventral and medial temporal cortex and cerebellum, suggesting that these regions mediate the effects of the drug on psychotic symptom

A False Case of Clozapine-Resistant Schizophrenia

One of the subjects that most concerns physicians is treatment-resistance. About 30%–60% of schizophrenia patients do not respond adequately to antipsychotic treatment and are known as refractory schizophrenia patients. Clozapine has been the drug of choice in such cases. However, approximately 30% of them do not respond to clozapine either. Here, we describe a patient with an initial diagnosis of refractory schizophrenia who had a history of dramatic aggressiveness. However, in this case, “refractoriness” was a wrong diagnosis. A case of psychosis secondary to epilepsy had been treated as schizophrenia for almost 20 years. Reports like this one are important because they remind us of how a thorough investigation can lead to the correct diagnosis and improve the patient's prognosis

Administration of Harmine and Imipramine Alters Creatine Kinase and Mitochondrial Respiratory Chain Activities in the Rat Brain

The present study evaluated mitochondrial respiratory chain and creatine kinase activities after administration of harmine (5, 10, and 15 mg/kg) and imipramine (10, 20, and 30 mg/kg) in rat brain. After acute treatment occurred an increase of creatine kinase in the prefrontal with imipramine (20 and 30 mg/kg) and harmine in all doses, in the striatum with imipramine (20 and 30 mg/kg) and harmine (5 and 10 mg/kg); harmine (15 mg/kg) decreased creatine kinase. In the chronic treatment occurred an increase of creatine kinase with imipramine (20 mg/kg), harmine (5 mg/kg) in the prefrontal with imipramine (20 and 30 mg/kg) and harmine (5 and 10 mg/kg) in the striatum. In the acute treatment, the complex I increased in the prefrontal with harmine (15 mg/kg) and in the striatum with harmine (10 mg/kg); the complex II decreased with imipramine (20 and 30 mg/kg) in the striatum; the complex IV increased with imipramine (30 mg/kg) in the striatum. In the chronic treatment, the complex I increased with harmine (5 mg/kg) in the prefrontal; the complex II increased with imipramine (20 mg/kg) in the prefrontal; the complex IV increased with harmine (5 mg/kg) in the striatum. Finally, these findings further support the hypothesis that harmine and imipramine could be involved in mitochondrial function

Cannabidiol Prevents Motor and Cognitive Impairments Induced by Reserpine in Rats

Cannabidiol (CBD) is a non-psychotomimetic compound from Cannabis sativa that presents antipsychotic, anxiolytic, anti-inflammatory, and neuroprotective effects. In Parkinson's disease patients, CBD is able to attenuate the psychotic symptoms induced by L-DOPA and to improve quality of life. Repeated administration of reserpine in rodents induces motor impairments that are accompanied by cognitive deficits, and has been applied to model both tardive dyskinesia and Parkinson's disease. The present study investigated whether CBD administration would attenuate reserpine-induced motor and cognitive impairments in rats. Male Wistar rats received four injections of CBD (0.5 or 5 mg/kg) or vehicle (days 2-5). On days 3 and 5, animals received also one injection of 1 mg/kg reserpine or vehicle. Locomotor activity, vacuous chewing movements, and catalepsy were assessed from day 1 to day 7. On days 8 and 9, we evaluated animals' performance on the plus-maze discriminative avoidance task, for learning/memory assessment. CBD (0.5 and 5 mg/kg) attenuated the increase in catalepsy behavior and in oral movements - but not the decrease in locomotion induced by reserpine. CBD (0.5 mg/kg) also ameliorated the reserpine-induced memory deficit in the discriminative avoidance task. Our data show that CBD is able to attenuate motor and cognitive impairments induced by reserpine, suggesting the use of this compound in the pharmacotherapy of Parkinson's disease and tardive dyskinesia.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Sao Paulo, Dept Psychiat, Interdisciplinary Lab Clin Neurosci, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Pharmacol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Psychobiol, Sao Paulo, BrazilUniv Sao Paulo, Dept Neurosci & Behav, Ribeirao Preto, BrazilNatl Council Sci & Technol Dev, Natl Inst Translat Med, Ribeirao Preto, BrazilInterdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), São Paulo, BrazilDepartment of Pharmacology, Universidade Federal de São Paulo (UNIFESP), São Paulo, BrazilDepartment of Psychobiology, Universidade Federal de São Paulo (UNIFESP), São Paulo, BrazilFAPESP: 2010/07994-3FAPESP: 2015/03354-3CNPq/MS/SCTIE/DECIT: 26/2014CNPq/MS/SCTIE/DECIT: 466805/2014-4Web of Scienc

Cannabinoid receptor CB1 mediates baseline and activity-induced survival of new neurons in adult hippocampal neurogenesis

<p>Abstract</p> <p>Background</p> <p>Adult neurogenesis is a particular example of brain plasticity that is partially modulated by the endocannabinoid system. Whereas the impact of synthetic cannabinoids on the neuronal progenitor cells has been described, there has been lack of information about the action of plant-derived extracts on neurogenesis. Therefore we here focused on the effects of Δ9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) fed to female C57Bl/6 and Nestin-GFP-reporter mice on proliferation and maturation of neuronal progenitor cells and spatial learning performance. In addition we used cannabinoid receptor 1 (CB1) deficient mice and treatment with CB1 antagonist AM251 in Nestin-GFP-reporter mice to investigate the role of the CB1 receptor in adult neurogenesis in detail.</p> <p>Results</p> <p>THC and CBD differed in their effects on spatial learning and adult neurogenesis. CBD did not impair learning but increased adult neurogenesis, whereas THC reduced learning without affecting adult neurogenesis. We found the neurogenic effect of CBD to be dependent on the CB1 receptor, which is expressed over the whole dentate gyrus. Similarly, the neurogenic effect of environmental enrichment and voluntary wheel running depends on the presence of the CB1 receptor. We found that in the absence of CB1 receptors, cell proliferation was increased and neuronal differentiation reduced, which could be related to CB1 receptor mediated signaling in Doublecortin (DCX)-expressing intermediate progenitor cells.</p> <p>Conclusion</p> <p>CB1 affected the stages of adult neurogenesis that involve intermediate highly proliferative progenitor cells and the survival and maturation of new neurons. The pro-neurogenic effects of CBD might explain some of the positive therapeutic features of CBD-based compounds.</p