Metabolic alterations and distribution of five-carbon precursors in jasmonic acid-elicited Catharanthus roseus cell suspension cultures

Plant science

Enhanced benzophenanthridine alkaloid production and protein expression with combined elicitor in Eschscholtzia californica suspension cultures

Production of the benzophenanthridine alkaloids in Eschscholtzia californica suspension cell cultures was optimized by adding 0.5 mg methyl jasmonate (MJ) and 0.02 mg salicylic acid (SA)/g FCW after 7 days cultivation. Sanguinarine reached 24 mg/g DCW by such treatment; 10 times higher than in control cell cultures. MJ and SA induced expression of berberine bridge enzyme and 3'-hydroxy-(S)-N-methylcoclaurine-4'-O-methyltransferase, respectively. MJ plus SA induced over-expression of both enzymes.X118sciescopu

Synergistic effects of sequential treatment with methyl jasmonate, salicylic acid and yeast extract on benzophenanthridine alkaloid accumulation and protein expression in Eschscholtzia californica suspension cultures

To develop an optimal bioprocess for secondary metabolite production and explain the bioprocess at the molecular level, we examine the synergistic effects of sequential treatment with methyl jasmonate (MJ), salicylic acid (SA) and yeast extract (YE) on benzophenanthridine alkaloid accumulation and protein expression in Eschscholtzia californica suspension cultures. Serial treatment of MJ, SA and YE at 24h intervals enhanced the accumulation of dihydrosanguinarine (2.5 times) and sanguinarine (5.5 times). This sequential treatment using different signal elicitors was more effective than single elicitor or simultaneous treatment of the elicitors; it induced benzophenanthridine alkaloid accumulation to 917.7 +/- 42.0 mg/L. Also, (S)-methylcoclaurine-3'-hydroxylase (CYP80B1) and 3'-hydroxy-(S)-N-methylcoclaurine-4'-O-methyltransferase (4'OMT) expressions among enzymes in sanguinarine biosynthetic pathway explained the synergistic effects by sequential treatment of the elicitors. The sequential treatment strategy using elicitors related to different signal transduction pathways can be used to design better processes to increase accumulation of secondary metabolites in plant cell culture. Analysis of protein expression provides the detailed information about metabolite accumulation through the correlated results. (C) 2008 Elsevier B.V. All rights reserved.X1123sciescopu

Reward learning impairment in patients with first-episode schizophrenia-spectrum disorder

This journal suppl. entitled: Abstracts of the 4th Biennial Schizophrenia International Research ConferenceBACKGROUND: Accumulating evidence indicated that schizophrenia patients exhibited reward learning impairment. Nonetheless, most previous studies focused on chronically-ill patients who had longstanding exposure to antipsychotic medication treatment which may interfere with reward processing. In this study, we aimed to investigate reward learning impairment (gradual reinforcement learning) in patients with first-episode schizophrenia-spectrum disorder with particular focus on its relationship with a key negative symptom sub-domain, namely avolition. METHODS: Thirty-one patients with first-episode DSM-IV schizophrenia, schizophreniform disorder or schizoaffective disorder (treated with antipsychotic for 3-6 months) and 33 healthy controls matched with age, sex and educational level were recruited. Each subject completed a computerized Go/No Go task, in which they had to decide whether or not to choose each stimulus which had different reinforcement probabilities. The task comprised 3 training blocks and 1 transfer phase presenting novel combinations of previously learned stimuli. A battery of cognitive assessments was administered to patients and HC. Patients were assessed with symptom severity using PANSS and SANS (for negative symptoms). Data on antipsychotic medication treatment was obtained. Omnibus repeated measures ANOVA and one-way ANOVAs were used to compare gradual reinforcement learning performance of patients and HC. Spearman’s correlational analyses were used to examine the association between reinforcement learning deficit and symptom dimensions. RESULTS: Patients did not differ from HC in terms of age (P: mean: 24.81, SD: 7.42; HC: mean: 23.68, SD: 7.49), sex (P: male: 42%; HC: male:47%) and years of education (P: mean: 12.48, SD: 2.67; HC: mean: 12.70, SD: 2.73). HC had significantly higher IQ estimate and better overall cognitive functions than patients. Regarding gradual reinforcement learning performance, patients had significantly lower accuracy in positive stimuli in training blocks 2 (F(1,62) = 6.25, p<0.05) and 3 (F(1,62) = 8.00, P<0.05). Patients also had longer reaction time to positive stimuli in training blocks 2 (F(1,62) = 9.22, P<0.05) and 3 (F(1,62) = 4.70, P<0.05). Avolition score (derived from Avolition-Asociality global sum score of SANS) negatively correlated with positive stimuli’s accuracy in transfer phase (r(31)=−0.48, p<0.01). DISCUSSION: The findings of this study indicated that gradual reinforcement learning deficit (esp. positive reinforcement dysfunction) was found in the initial stage of schizophrenia and was associated with severity of volitional impairment. Further prospective research is required to clarify longitudinal course of reward leaning impairment and its relationship with outcome on symptoms and functioning