Protective effect of creatine in hippocampal cell cultures challenged with oxidative stress.

<p>Hippocampal cells (DIV 15) were incubated with hydrogen peroxide in rising concentrations in absence or in presence of 5 mM creatine. After 24 h the LDH release into the cell culture supernatant was assessed. Total protein of the cell monolayer was used as a reference. Data are expressed as arbitrary units per mg protein +/− standard deviation. Each data point represents the mean of triplicates. Each experiment was independently performed in triplicate. Statistical analysis was performed by unpaired Student's T-test. *denotes statistical significance at a level of p<0.01.</p

Raw data of IRI scores (mean, SD) by OXTR rs2254298 and rs53576 genotypes in schizophrenia patients (SZ, n = 145) and healthy controls (HC, n = 145).

1)<p>T-test for independent samples: T = −3.493, p<0.001.</p

Impact of creatine on glutamate efflux into the supernatant in hippocampal cell cultures exposed to hydrogen peroxide.

<p>Hippocampal cells (DIV 15) were incubated with rising concentrations of hydrogen peroxide in absence or in presence of 5 mM creatine. After 24 h the glutamate release into the cell culture supernatant was enzymatically determined. Total protein of the lysed cell monolayer was used as a reference. Data are expressed as glutamate concentration per mg protein +/− standard deviation. Each data point represents the mean of triplicates. Each experiment was independently performed in triplicate. Statistical analysis was performed by unpaired Student's T-test. *denotes statistical significance at a level of p<0.01.</p

Protective effect of creatine in hippocampal cell cultures exposed to glutamate.

<p>Hippocampal cells (DIV 17) were incubated with rising concentrations of glutamate in absence or in presence of 5 mM creatine. After 24 h the LDH release into the cell culture supernatant was determined. Total protein of the lysed cell monolayer was used as a reference. Data are expressed as arbitrary units per mg protein +/− standard deviation. Each data point represents the mean of triplicates. Each experiment was independently performed in triplicate. Statistical analysis was performed by unpaired Student's T-test. *denotes statistical significance at a level of p<0.01.</p

Effect of creatine on intracellular ATP/Phosphocreatine content in hippocampal cells exposed to glutamate.

<p>Hippocampal cells (DIV 17) were challenged with glutamate at rising concentrations in absence or presence of 5 mM creatine. After 24 h of incubation the cells were harvested and intracellular ATP/PCr concentration was determined by luciferin/luciferase chemiluminescence. Total protein content of the cell lysate was employed as a reference. Data are expressed as intracellular ATP concentration equivalents corrected for total protein +/− standard deviation. Each data point represents the mean of triplicates. The experiment was independently performed in triplicate. Unpaired Student's T-test was used for statistics. *denotes statistical significance at a level of p<0.01.</p

Effect of creatine on intracellular ATP/Phosphocreatine content in hippocampal cells under oxidative stress.

<p>Hippocampal cells (DIV 15) were challenged with hydrogen peroxide at rising concentrations in absence or presence of 5 mM creatine. After 24 h the cells were harvested for determination of intracellular ATP/PCr concentration, which was determined by luciferin/luciferase chemiluminescence and for measurement of total protein content, which served as a reference. Data are expressed as intracellular ATP concentration equivalents corrected for total protein +/− standard deviation. Each data point represents the mean of triplicates. The experiment was independently performed in triplicate. Unpaired Student's T-test was used for statistics. *denotes statistical significance at a level of p<0.01.</p

Impact of creatine pre-incubation on NMDA-triggered intracellular calcium rise in hippocampal cells.

<p>Hippocampal cell cultures (DIV 18) were incubated with 5 mM of creatine for 18 h. Cells were harvested, dissociated and loaded with FURA PE-3/AM. Ca²⁺ ratiometry was performed in 0.5×10⁶ cells/ml at 37°C. After stable baseline ratios were achieved NMDA was added and the response was recorded for 400 seconds. Thapsigargin was added for SERCA inhibition. The tracings are representative for 5 individual experiments by calculating curve means. Data for intracellular Ca²⁺ are expressed in arbitrary units. The second tracing shows responses in creatine-pretreated cells, the first one has been acquired from control cells.</p

Self rated dimensions of empathy (Interpersonal Reactivity Index, IRI) in schizophrenic patients (n = 145) and controls (n = 145); between-group comparisons.

1)<p>T-test for independent samples (two-sided). Significant results are indicated in bold type.</p

OXTR rs2254298 polymorphisms and IRI ‘empathic concern’ scores in schizophrenic patients and healthy controls.

<p>Self-rated IRI ‘empathic concern’ scores are significantly higher in schizophrenic patients endowed with an OXTR SNP rs2254298 AA- or AG-genotype compared to GG-genotype carriers (n = 145; mean, SD; t-test for independent samples, ***: p<0.001), while no significant differences between genotypes are detected in healthy controls (n = 145; p>0.05).</p

OXTR rs2254298 and rs53576 polymorphisms and PANSS positive, negative and general psychopathology scores in schizophrenic patients.

<p>Schizophrenic patients carrying AA- or AG-genotypes of OXTR rs2254298 show significantly higher PANSS general psychopathology scores than GG-carriers (n = 145; mean, SD; t-test for independent samples, *: p<0.05).</p