19 research outputs found

    High flavonoid accompanied with high starch accumulation triggered by nutrient starvation in bioenergy crop duckweed (Landoltia punctata)

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    Background: As the fastest growing plant, duckweed can thrive on anthropogenic wastewater. The purple-backed duckweed, Landoltia punctata, is rich in starch and flavonoids. However, the molecular biological basis of high flavonoid and low lignin content remains largely unknown, as does the best method to combine nutrients removed from sewage and the utilization value improvement of duckweed biomass. Results: A combined omics study was performed to investigate the biosynthesis of flavonoid and the metabolic flux changes in L. punctata grown in different culture medium. Phenylalanine metabolism related transcripts were identified and carefully analyzed. Expression quantification results showed that most of the flavonoid biosynthetic transcripts were relatively highly expressed, while most lignin-related transcripts were poorly expressed or failed to be detected by iTRAQ based proteomic analyses. This explains why duckweed has a much lower lignin percentage and higher flavonoid content than most other plants. Growing in distilled water, expression of most flavonoid-related transcripts were increased, while most were decreased in uniconazole treated L. punctata (1/6 x Hoagland + 800 mg center dot L-1 uniconazole). When L. punctata was cultivated in full nutrient medium (1/6 x Hoagland), more than half of these transcripts were increased, however others were suppressed. Metabolome results showed that a total of 20 flavonoid compounds were separated by HPLC in L. punctata grown in uniconazole and full nutrient medium. The quantities of all 20 compounds were decreased by uniconazole, while 11 were increased and 6 decreased when grown in full nutrient medium. Nutrient starvation resulted in an obvious purple accumulation on the underside of each frond. Conclusions: The high flavonoid and low lignin content of L. punctata appears to be predominantly caused by the flavonoid-directed metabolic flux. Nutrient starvation is the best option to obtain high starch and flavonoid accumulation simultaneously in a short time for biofuels fermentation and natural products isolation

    Establishing and boosting communication in the European Reference Network for Rare Neurological Diseases (ERN-RND): the impact of offering free educational webinars

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    BACKGROUND: Since it first started operating in 2017, the European Reference Network for Rare Neurological Diseases (ERN-RND) implemented a multi-channel communication strategy to effectively reach its target audience: healthcare professionals, patients, researchers, industry representatives and the general public. We first created a website containing useful and up to date information, followed by social media accounts. Here, the analytical data collected about the ERN-RND website and social media channels was compared (Twitter, Facebook, YouTube) during two periods: October 2018 to September 2019, and the year after the ERN-RND free educational webinars were launched: from October 2019 to September 2020. This allowed us to quantify the impact of offering a tangible product (webinars) on the communication strategy. RESULTS: The analytical data obtained from October 2018 to September 2019 and from October 2019 to September 2020 clearly shows a significant increase in traffic and followers since the launch of the ERN-RND webinars in November 2019. We also created a communication survey which was disseminated between February and June 2021. We collected responses from 61 people: 38 healthcare professionals, 11 scientists, 10 patients (advocates), 2 industry representatives, 1 patient association, 1 charity representative, 1 resident and 1 master student. Most respondents answered “webinars” as the number one reason when asked about which content they look for on the ERN-RND website. CONCLUSIONS: Offering a tangible product—such as the webinars presented in this report—to a specific target group (healthcare professionals) supported our communication strategy by driving traffic to ERN-RND communication channels. It has also successfully tackled ERN-RND’s general aim: by enabling the flow of knowledge on rare neurological and movement disorders to the medical community in hospitals treating patients with these rare and complex conditions, patients ultimately benefit from improved and faster diagnosis, care, and treatment. We aim to set up similar strategies to effectively reach other or the same target groups. For healthcare professionals, organising eConsultations via the Clinical Patient Management System or disseminating standards of care such as diagnostic and therapeutic algorithms as well as clinical practice guidelines might offer potential. For the patient community, organising customised and multilingual webinars could also work. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13023-022-02209-9

    An open-label trial in Friedreich ataxia suggests clinical benefit with high-dose resveratrol, without effect on frataxin levels

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    Friedreich ataxia (FRDA) is due to a triplet repeat expansion in FXN, resulting in deficiency of the mitochondrial protein frataxin. Resveratrol is a naturally occurring polyphenol, identified to increase frataxin expression in cellular and mouse models of FRDA and has anti-oxidant properties. This open-label, non-randomized trial evaluated the effect of two different doses of resveratrol on peripheral blood mononuclear cell (PBMC) frataxin levels over a 12-week period in individuals with FRDA. Secondary outcome measures included PMBC FXN mRNA, oxidative stress markers, and clinical measures of disease severity. Safety and tolerability were studied. Twenty-four participants completed the study; 12 received low-dose resveratrol (1 g daily) and 12 high-dose resveratrol (5 g daily). PBMC frataxin levels did not change in either dosage group [low-dose group change: 0.08 pg/ÎĽg protein (95 % CI -0.05, 0.21, p = 0.21); high-dose group change: 0.03 pg/ÎĽg protein (95 % CI -0.10, 0.15, p = 0.62)]. Improvement in neurologic function was evident in the high-dose group [change in Friedreich Ataxia Rating Scale -3.4 points, 95 % CI (-6.6, -0.3), p = 0.036], but not the low-dose group. Significant improvements in audiologic and speech measures, and in the oxidative stress marker plasma F2-isoprostane were demonstrated in the high-dose group only. There were no improvements in cardiac measures or patient-reported outcome measures. No serious adverse events were recorded. Gastrointestinal side-effects were a common, dose-related adverse event. This open-label study shows no effect of resveratrol on frataxin levels in FRDA, but suggests that independent positive clinical and biologic effects of high-dose resveratrol may exist. Further assessment of efficacy is warranted in a randomized placebo-controlled trial

    Impact of D181V and A69T on the function of ferroportin as an iron export pump and hepcidin receptor

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    Mutations in the only known mammalian iron exporter ferroportin cause a rare iron overload disorder termed ferroportin disease. Two distinct clinical phenotypes are caused bi different disease mechanisms: mutations in ferroportin either cause loss of iron export function or gain of function due to resistance to hepcidin, the peptide hormone that normally downregulates ferroportin. The aim of the present study was to examine the disease mechanisms of the thus far unclassified A69T and D181V ferroportin mutations. We overexpressed wild-type and mutant ferroportin fused to green fluorescent protein in human embryonic kidney cells and used a F-59-eassay, intracellular ferritin concentrations, confocal microscopy and flow cytometry to study iron export function, subcellular localization and the responsiveness to hepcidin. While the A69T ferroportin mutation seems not to affect the iron export function it causes dose-dependent hepcidin resistance. We further found that D181V mutated ferroportin is iron export defective and hepcidin resistant, similar to the loss of function mutations A77D and C367X. This indicates that intact iron export might be necessary for hepcidin-induced downregulation of ferroportin. This hypothesis was investigated by studying the hepcidin response under modulation of iron availability. Incubation of wild-type ferroportin overexpressing cells with holo-transferrin increases the hepcidin effect whereas chelating extracellular ferrous iron causes hepcidin resistance. In this study we present data that postulates to classify the D181V ferroportin mutation as loss of function and the A69T mutation as dose-dependent hepcidin resistant and outline a possible causal link between iron export function and the hepcidin effect. (C) 2014 Elsevier B.V. All rights reserved

    An open-label trial in Friedreich ataxia suggests clinical benefit with high-dose resveratrol, without effect on frataxin levels

    No full text
    Friedreich ataxia (FRDA) is due to a triplet repeat expansion in FXN, resulting in deficiency of the mitochondrial protein frataxin. Resveratrol is a naturally occurring polyphenol, identified to increase frataxin expression in cellular and mouse models of FRDA and has anti-oxidant properties. This open-label, non-randomized trial evaluated the effect of two different doses of resveratrol on peripheral blood mononuclear cell (PBMC) frataxin levels over a 12-week period in individuals with FRDA. Secondary outcome measures included PMBC FXN mRNA, oxidative stress markers, and clinical measures of disease severity. Safety and tolerability were studied. Twenty-four participants completed the study; 12 received low-dose resveratrol (1 g daily) and 12 high-dose resveratrol (5 g daily). PBMC frataxin levels did not change in either dosage group [low-dose group change: 0.08 pg/ÎĽg protein (95% CI -0.05, 0.21, p = 0.21); high-dose group change: 0.03 pg/ÎĽg protein (95% CI -0.10, 0.15, p = 0.62)]. Improvement in neurologic function was evident in the high-dose group [change in Friedreich Ataxia Rating Scale -3.4 points, 95% CI (-6.6, -0.3), p = 0.036], but not the low-dose group. Significant improvements in audiologic and speech measures, and in the oxidative stress marker plasma F2-isoprostane were demonstrated in the high-dose group only. There were no improvements in cardiac measures or patient-reported outcome measures. No serious adverse events were recorded. Gastrointestinal side-effects were a common, dose-related adverse event. This open-label study shows no effect of resveratrol on frataxin levels in FRDA, but suggests that independent positive clinical and biologic effects of high-dose resveratrol may exist. Further assessment of efficacy is warranted in a randomized placebo-controlled trial
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