Protective role of olesoxime against wild-type α-synuclein-induced toxicity in human neuronally differentiated SHSY-5Y cells.

BACKGROUND AND PURPOSE: Parkinson's disease (PD) is usually diagnosed clinically from classical motor symptoms, while definitive diagnosis is made postmortem, based on the presence of Lewy bodies and nigral neuron cell loss. α-Synuclein (ASYN), the main protein component of Lewy bodies, clearly plays a role in the neurodegeneration that characterizes PD. Additionally, mutation in the SNCA gene or copy number variations are associated with some forms of familial PD. Here, the objective of the study was to evaluate whether olesoxime, a promising neuroprotective drug can prevent ASYN-mediated neurotoxicity. EXPERIMENTAL APPROACH: We used here a novel, mechanistically approachable and attractive cellular model based on the inducible overexpression of human wild-type ASYN in neuronally differentiated human neuroblastoma (SHSY-5Y) cells. This model demonstrates gradual cellular degeneration, coinciding temporally with the appearance of soluble and membrane-bound ASYN oligomers and cell death combining both apoptotic and non-apoptotic pathways. KEY RESULTS: Olesoxime fully protected differentiated SHSY-5Y cells from cell death, neurite retraction and cytoplasmic shrinkage induced by moderate ASYN overexpression. This protection was associated with a reduction in cytochrome c release from mitochondria and caspase-9 activation suggesting that olesoxime prevented ASYN toxicity by preserving mitochondrial integrity and function. In addition, olesoxime displayed neurotrophic effects on neuronally differentiated SHSY-5Y cells, independent of ASYN expression, by promoting their differentiation. CONCLUSIONS AND IMPLICATIONS: Because ASYN is a common underlying factor in many cases of PD, olesoxime could be a promising therapy to slow neurodegeneration in PD.

Olesoxime delays muscle denervation, astrogliosis, microglial activation and motoneuron death in an ALS mouse model.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. The pathology is mimicked to a striking degree in transgenic mice carrying familial ALS-linked SOD1 gene mutations. Olesoxime (TRO19622), a novel neuroprotective and reparative compound identified in a high-throughput screen based on motoneuron (MN) survival, delays disease onset and improves survival in mutant SOD1(G93A) mice, a model for ALS. The present study further analyses the cellular basis for the protection provided by olesoxime at the neuromuscular junctions (NMJ) and the spinal cord. Studies were carried out at two disease stages, 60 days, presymptomatic and 104 days, symptomatic. Cohorts of wild type and SOD1(G93A) mice were randomized to receive olesoxime-charged food pellets or normal diet from day 21 onward. Analysis showed that olesoxime initially reduced denervation from 60 to 30% compared to SOD1(G93A) mice fed with control food pellets while at the symptomatic stage only a few NMJs were still preserved. Immunostaining of cryostat sections of the lumbar spinal cord with VAChT to visualize MNs, GFAP for astrocytes and Iba1 for microglial cells showed that olesoxime strongly reduced astrogliosis and microglial activation and prevented MN loss. These studies suggest that olesoxime exerts its protective effect on multiple cell types implicated in the disease process in SOD1(G93A) mice, slowing down muscle denervation, astrogliosis, microglial activation and MN death. A Phase 3 clinical study in ALS patients will determine whether olesoxime could be beneficial for the treatment of ALS.

The 24 h urinary cortisol/cortisone ratio and epinephrine/norepinephrine ratio for monitoring training in young female tennis players.

The effect of training variations on the 24 h urinary cortisol/cortisone (C/Cn) ratio and the epinephrine/norepinephrine (E/NE) ratio in relation with mood (evaluated using the Brunel Mood Scale: BRUMS) and performance was investigated in seven trained young female tennis players (12.8 +/- 1.7 years). Like the proposed model in adults, the monitoring of hormonal and mood parameters could be a useful index in training follow-up in young sportswomen. Assessment of nutritional intake, nitrogen excretion rate and nitrogen balance were also determined to measure the dietary practice of these athletes. Nitrogen balance was calculated from the mean daily protein intake and the urinary nitrogen excretion. Data were collected after a 1-month rest (September, T1), 3 months after T1 (after technical and endurance training: December, T2) and 7 months after T1 (after 4 months of increasing-volume/high-intensity training: March, T3). A significant increase in C/Cn ratio (+ 30 %, p < 0.05) were noted from T1 to T3. In the same time, urinary NE concentrations decreased significantly. The E/NE ratio increased from T1 to T2 and decreased at T3 (T1 vs. T3: - 30 %, p < 0.05). The BRUMS inventory at T3 reflected changes in specific mood states with a significant increase in fatigue and anger scores, while vigor scores decreased significantly compared to T1. This period also corresponded with the lowest percentage of matches won and with the highest training load. Energy intake was about 16 % lower than the French recommendations for girls of the same age. However, a positive nitrogen balance was observed from a mean intake of 1.0 g x kg (-1) x day (-1). Our results reveal that an increase of overnight urinary C/Cn ratio and a decrease of E/NE ratio are concomitant with alterations in mood state and performance, all these parameters being associated with physical and psychological stress.

24-hr urinary catecholamine excretion, training and performance in elite swimmers.

The aim of the present study was to investigate the effects of training variations on 24-hr urinary noradrenaline (NA) and adrenaline (Ad) levels and the adrenaline/noradrenaline (Ad/NA) ratio to search for a possible relationship between catecholamine excretion, training, and performance in highly trained swimmers. Fourteen swimmers (5 female and 9 male) were tested after 4 weeks of intense training (IT), 3 weeks of reduced training (RT), and 5 weeks of low training (LT). At the end of each period, the swimmers performed their best event at an official competition. Individual performances were expressed as percentage of the previous season's best performance. The changes in NA levels after 4 weeks of IT were negatively related to changes in training volume (r=-0.70, p<0.01) and total training load (r=-0.68, p<0.02). NA levels measured at the end of IT were positively related to changes in performance after three weeks of RT (r=0.77, p<0.01). The percentage changes in performance between RT and LT were related to NA levels at the end of RT (r=0.60; p<0.04). Ad/NA ratios and Ad were related to performance (r=0.58, p<0.01; r=52, p<0.01; respectively). The differences in Ad/NA ratios and Ad between two consecutive competitions were related to the differences in performance (r=0.59, p<0.01; r=0.49, p<0.01; respectively). 24-hr NA and the Ad/NA excretion ratio were related to both training variations and performance. Thus, 24-hr NA levels and Ad/NA ratio may provide useful markers for monitoring training stress in elite swimmers.

Critical study of common conditions of storage of glucocorticoids and catecholamines in 24-h urine collected during resting and exercising conditions.

BACKGROUND: Except immediate freezing of the samples, no practical method has been validated for preservation of glucocorticoids and catecholamines in 24-h urine collection. Furthermore, the influence of urine storage at bladder temperature during periods of different lengths and the effect of prior exercise on preservation of these hormones in the bladder have not been investigated until now. METHODS: Ten healthy volunteers collected their urine both after a resting and after an exercise session. Urine was aliquoted into tubes which were stored during 24 h in the presence or in the absence of preservatives and at different temperatures. Two samples were stored either 3 or 9 h at 37 degrees C (bladder temperature) without additive. RESULTS AND CONCLUSIONS: When collecting 24-h urine samples for glucocorticoids determination, sample can be stored at room temperature during the 24-h collection period without compromising glucocorticoids preservation. When collecting 24-h urine samples for catecholamines determination, samples have to be chilled without preservative during the whole of the collection period. If the samples have to be stored at room temperature, HCl should be used. Moreover, we report for the first time that catecholamines can be degraded in the bladder and therefore that subjects should urinate every 3 h during either a resting or an exercising day.

Acute and chronic effects of exercise on tissue sensitivity to glucocorticoids.

The aim of this study was to address the effect of endurance training on tissue sensitivity to glucocorticoids (GC) in both resting and exercising conditions. In vitro dexamethasone inhibition of LPS-induced interleukin-6 secretion in cultures of peripheral monocytes was compared in untrained subjects (UT) and in endurance-trained men (ET) at the end of a 2-h run and during exercise recovery. We demonstrated an in vitro plasticity of sensitivity of monocytes to GC in ET men, superimposed to changes in systemic cortisol concentrations (plasma and saliva). Compared with sedentary men, similar resting cortisol levels in ET men are associated with decreased sensitivity of monocytes to GC 8 and 24 h after the end of the last training session (P < 0.05, ET vs. UT). Moreover, in these ET subjects, an acute bout of exercise increased the sensitivity of monocytes to GC (at 1000 and 1200; ET vs. UT, P > 0.05). This acute exercise-induced increase in tissue sensitivity to GC, which is synchronous with activation of the hypothalamo-pituitary adrenal axis, may act to shut off muscle inflammatory reaction and cytokine synthesis and then decrease exercise-induced muscle damage or inflammatory response. By contrast, the decreased sensitivity of monocytes to GC reported in ET men 24 h after the last bout of exercise may be related to the process of desensitization that may act to protect the body from prolonged, exercise-induced cortisol secretion. These acute and chronic effects of exercise on tissue sensitivity to GC demonstrate an adaptation of the hypothalamo-pituitary adrenal axis to repeated and prolonged exercise-induced increases in GC secretion.