Polyglutamine-Expanded Androgen Receptor Alteration of Skeletal Muscle Homeostasis and Myonuclear Aggregation Are Affected by Sex, Age and Muscle Metabolism.

Polyglutamine (polyQ) expansions in the androgen receptor (AR) gene cause spinal and bulbar muscular atrophy (SBMA), a neuromuscular disease characterized by lower motor neuron (MN) loss and skeletal muscle atrophy, with an unknown mechanism. We generated new mouse models of SBMA for constitutive and inducible expression of mutant AR and performed biochemical, histological and functional analyses of phenotype. We show that polyQ-expanded AR causes motor dysfunction, premature death, IIb-to-IIa/IIx fiber-type change, glycolytic-to-oxidative fiber-type switching, upregulation of atrogenes and autophagy genes and mitochondrial dysfunction in skeletal muscle, together with signs of muscle denervation at late stage of disease.

Insulin-like growth factor 1 signaling in motor neuron and polyglutamine diseases: From molecular pathogenesis to therapeutic perspectives.

The pleiotropic peptide insulin-like growth factor 1 (IGF-I) regulates human body homeostasis and cell growth. IGF-I activates two major signaling pathways, namely phosphoinositide-3-kinase (PI3K)/protein kinase B (PKB/Akt) and Ras/extracellular signal-regulated kinase (ERK), which contribute to brain development, metabolism and function as well as to neuronal maintenance and survival. In this review, we discuss the general and tissue-specific effects of the IGF-I pathways.

Pituitary Adenylyl Cyclase Activating Polypeptide (PACAP) Signaling and the Cell Cycle Machinery in Neurodegenerative Diseases.

Pituitary adenylyl cyclase activating polypeptide (PACAP) is a neuropeptide with great neuroprotective effects and remarkable therapeutic potential. PACAP activates several cellular pathways to exert its protective effects. Emerging evidence shows that PACAP can modify the levels and activity of cell cycle components involved in neurodegeneration to protect neurons from death.

Mutations in TGM6 induce the unfolded protein response in SCA35.

Spinocerebellar ataxia type 35 (SCA35) is a rare autosomal-dominant neurodegenerative disease caused by mutations in the TGM6 gene, which codes for transglutaminase 6 (TG6). Mutations in TG6 induce cerebellar degeneration by an unknown mechanism. We identified seven patients bearing new mutations in TGM6.

Pro-apoptotic properties of morphine in neuroblastoma × glioma NG108-15 hybrid cells: modulation by yohimbine.

Short-term incubation with pharmacologically relevant concentrations of morphine has been shown to transiently affect the metabolism and redox status of NG108-15 cells through δ-opioid receptor stimulation, but apparently did not provoke cell death. The present work tries to determine if incubation with morphine at longer time intervals (24 h) provokes apoptosis and/or necrosis, as it has been described in other cell lines. We have also checked the potential modulatory role of yohimbine on these effects, on the basis of the previously described interactions between this drug and opioid receptor ligands.

Yohimbine does not affect opioid receptor activation but prevents adenylate cyclase regulation by morphine in NG108-15 cells.

Aims: Yohimbine has been shown to modulate the pharmacological actions of opioid drugs in a way that could be of potential therapeutic interest. This work tries to study if this interaction involves the impairment of opioid receptor activation at the cellular level by studying the effects of morphine and yohimbine on NG108-15 neuroblastoma x glioma hybrid cells.

Main Methods: [(35)S]GTPγS binding assays were performed to study δ-opioid and α(2B)-adrenoceptor activation by opioid and adrenoceptor agonists in the presence and absence of yohimbine.

Yohimbine prevents the effect of morphine on the redox status of neuroblastomaxglioma NG108-15 cells.

The alpha(2)-adrenoceptor antagonist yohimbine is known to interact with the effects of opioid receptor agonists in vivo, and thus could modulate the action of morphine-like analgesics. The focus of the present work was to further study these interactions in a cell culture endowed with opioid and alpha(2)-adrenoceptors in order to know if they could happen at the cellular level. In a first step, incubation with morphine (10microM) or the delta opioid agonist DPDPE (1microM) for 6h was shown to decrease the reduction of (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) by NG108-15 neuroblastomaxglioma hybrid cells in a naloxone-sensitive manner, thus showing that the opioids affect the redox status of the cells in a delta receptor-mediated way.

Behavioral and in vitro evaluation of tetrodotoxin tolerability for therapeutic applications.

Tetrodotoxin (TTX) injection is currently being studied in clinical trials for potential antinociceptive applications. This work tries to increase the knowledge of its biological tolerability by using a behavioral procedure that can detect aversive effects of drug treatments, as well as in vitro cytotoxicity studies in non-excitable cell systems. Place conditioning studies with Sprague-Dawley male rats showed that pharmacologically active TTX injections (2.