Methodological advancements in organ-specific ectopic lipid quantitative characterization: Effects of high fat diet on muscle and liver intracellular lipids.

Ectopic lipid accumulation is a hallmark of metabolic diseases, linking obesity to non-alcoholic fatty liver disease, insulin resistance and diabetes. The use of zebrafish as a model of obesity and diabetes is raising due to the conserved properties of fat metabolism between humans and zebrafish, the homologous genes regulating lipid uptake and transport, the implementation of the '3R's principle and their cost-effectiveness. To date, a method allowing the conservation of lipid droplets (LDs) and organs in zebrafish larvae to image ectopic lipids is not available. Our objectives were to develop a novel methodology to quantitatively evaluate organ-specific LDs, in skeletal muscle and liver, in response to a nutritional perturbation. We developed a novel embedding and cryosectioning protocol allowing the conservation of LDs and organs in zebrafish larvae. To establish the quantitative measures, we used a three-arm parallel nutritional intervention design. Zebrafish larvae were fed a control diet containing 14% of nutritional fat or two high fat diets (HFDs) containing 25 and 36% of dietary fats. In muscle and liver, LDs were characterized using immunofluorescence confocal microscopy. In liver, intrahepatocellular lipids were discriminated from intrasinusoid lipids. To complete liver characteristics, fibrosis was identified with Masson's Trichrome staining. Finally, to confirm the conservation and effect of HFD, molecular players of fat metabolism were evaluated by RT-qPCR. The cryosections obtained after setting up the embedding and cryopreservation method were of high quality, preserving tissue morphology and allowing the visualization of ectopic lipids. Both HFDs were obesogenic, without modifying larvae survival or development. Neutral lipid content increased with time and augmented dietary fat. Intramuscular LD volume density increased and was explained by an increase in LDs size but not in numbers. Intrahepatocellular LD volume density increased and was explained by an increased number of LDs, not by their increased size. Sinusoid area and lipid content were both increased. Hepatic fibrosis appeared with both HFDs. We observed alterations in the expression of genes associated with LD coating proteins, LD dynamics, lipogenesis, lipolysis and fatty acid oxidation. In this study, we propose a reproducible and fast method to image zebrafish larvae without losing LD quality and organ morphology. We demonstrate the impact of HFD on LD characteristics in liver and skeletal muscle accompanied by alterations of key players of fat metabolism. Our observations confirm the evolutionarily conserved mechanisms in lipid metabolism and reveal organ specific adaptations. The methodological advancements proposed in this work open the doors to study organelle adaptations in obesity and diabetes related research such as lipotoxicity, organelle contacts and specific lipid depositions

Isolation and analysis of high quality nuclear DNA with reduced organellar DNA for plant genome sequencing and resequencing

<p>Abstract</p> <p>Background</p> <p>High throughput sequencing (HTS) technologies have revolutionized the field of genomics by drastically reducing the cost of sequencing, making it feasible for individual labs to sequence or resequence plant genomes. Obtaining high quality, high molecular weight DNA from plants poses significant challenges due to the high copy number of chloroplast and mitochondrial DNA, as well as high levels of phenolic compounds and polysaccharides. Multiple methods have been used to isolate DNA from plants; the CTAB method is commonly used to isolate total cellular DNA from plants that contain nuclear DNA, as well as chloroplast and mitochondrial DNA. Alternatively, DNA can be isolated from nuclei to minimize chloroplast and mitochondrial DNA contamination.</p> <p>Results</p> <p>We describe optimized protocols for isolation of nuclear DNA from eight different plant species encompassing both monocot and eudicot species. These protocols use nuclei isolation to minimize chloroplast and mitochondrial DNA contamination. We also developed a protocol to determine the number of chloroplast and mitochondrial DNA copies relative to the nuclear DNA using quantitative real time PCR (qPCR). We compared DNA isolated from nuclei to total cellular DNA isolated with the CTAB method. As expected, DNA isolated from nuclei consistently yielded nuclear DNA with fewer chloroplast and mitochondrial DNA copies, as compared to the total cellular DNA prepared with the CTAB method. This protocol will allow for analysis of the quality and quantity of nuclear DNA before starting a plant whole genome sequencing or resequencing experiment.</p> <p>Conclusions</p> <p>Extracting high quality, high molecular weight nuclear DNA in plants has the potential to be a bottleneck in the era of whole genome sequencing and resequencing. The methods that are described here provide a framework for researchers to extract and quantify nuclear DNA in multiple types of plants.</p

Axial stretch-dependent cation entry in dystrophic cardiomyopathy: Involvement of several TRPs channels

International audienceIn Duchenne muscular dystrophy (DMD), deficiency of the cytoskeletal protein dystrophin leads to well-described defects in skeletal muscle but also to dilated cardiomyopathy (DCM). In cardiac cells, the subsarcolemmal localization of dystrophin is thought to protect the membrane from mechanical stress. The dystrophin deficiency leads to membrane instability and a high stress-induced Ca(2+) influx due to dysregulation of sarcolemmal channels such as stretch-activated channels (SACs). In this work divalent cation entry has been explored in isolated ventricular Wild Type (WT) and mdx cardiomyocytes in two different conditions: at rest and during the application of an axial stretch. At rest, our results suggest that activation of TRPV2 channels participates to a constitutive basal cation entry in mdx cardiomyocytes.Using microcarbon fibres technique, an axial stretchwas applied to mimic effects of physiological conditions of ventricular filling and study on cation influx bythe Mn(2+)-quenching techniquedemonstrated a high stretch-dependentcationic influx in dystrophic cells, partially due to SACs. Involvement of TRPs channels in this excessive Ca(2+) influx has been investigated using specific modulators and demonstratedboth sarcolemmal localization and an abnormal activity of TRPV2 channels. In conclusion, TRPV2 channels are demonstrated here to play a key role in cation influx and dysregulation in dystrophin deficient cardiomyocytes, enhanced in stretching conditions

Data on calcium increases depending on stretch in dystrophic cardiomyocytes

In this data article, intracellular Ca2+ concentration ([Ca2+]i) was measured in isolated ventricular Wild Type (WT) and mdx cardiomyocytes in two different conditions: at rest and during the application of an axial stretch. Using a carbon microfibers technique, axial stretch was applied to mimic effects of physiological conditions of ventricular filling. A study of cation entry with the same experimental model and the manganese quenching method reported (i) a constitutive cation entry in mdx cardiomyocytes and (ii) the involvement of TRPV2 channels in axial-stretch dependant cation entry, “Axial stretch-dependent cation entry in dystrophic cardiomyopathy: involvement of several TRPs channels” (Aguettaz et al., 2016) [1].Here, the Ca2+ dye fluo-8 was used for [Ca2+]i measurement, in both resting and stretching conditions, using a perfusion protocol starting initially with a calcium free Tyrode solution followed by the perfusion of 1.8 mM Ca2+ Tyrode solution. The variation of [Ca2+]i was found higher in mdx cardiomyocytes. Keywords: Calcium, TRPs channels, Stretch, Cardiomyocytes, Dystrophi

BerILL The ultimate humidity chamber for neutron scattering

We present the design and the performances of a precision humidity chamber for neutron diffraction which is the result of a very fruitful collaboration between the Helmholtz Zentrum Berlin and the Institut Laue Langevin. The sample temperature can be set between 10 and 85 C. The relative humidity is controlled from 10 to 99.9 0.01 by controlling the temperatures of the sample and a water bath at the millidegree Celsius scale. Sample exchanges are extremely easy and the operation only requires entering two parameters sample temperature and relative humidity. The performances are confirmed by neutron diffraction measurements performed on DMPC and DOP

Intravenous thrombolysis or endovascular therapy for acute ischemic stroke associated with cervical internal carotid artery occlusion: the ICARO-3 study

The aim of the ICARO-3 study was to evaluate whether intra-arterial treatment, compared to intravenous thrombolysis, increases the rate of favourable functional outcome at 3 months in acute ischemic stroke and extracranial ICA occlusion. ICARO-3 was a non-randomized therapeutic trial that performed a non-blind assessment of outcomes using retrospective data collected prospectively from 37 centres in 7 countries. Patients treated with endovascular treatment within 6 h from stroke onset (cases) were matched with patients treated with intravenous thrombolysis within 4.5 h from symptom onset (controls). Patients receiving either intravenous or endovascular therapy were included among the cases. The efficacy outcome was disability at 90 days assessed by the modified Rankin Scale (mRS), dichotomized as favourable (score of 0–2) or unfavourable (score of 3–6). Safety outcomes were death and any intracranial bleeding. Included in the analysis were 324 cases and 324 controls: 105 cases (32.4 %) had a favourable outcome as compared with 89 controls (27.4 %) [adjusted odds ratio (OR) 1.25, 95 % confidence interval (CI) 0.88–1.79, p = 0.1]. In the adjusted analysis, treatment with intra-arterial procedures was significantly associated with a reduction of mortality (OR 0.61, 95 % CI 0.40–0.93, p = 0.022). The rates of patients with severe disability or death (mRS 5–6) were similar in cases and controls (30.5 versus 32.4 %, p = 0.67). For the ordinal analysis, adjusted for age, sex, NIHSS, presence of diabetes mellitus and atrial fibrillation, the common odds ratio was 1.15 (95 % IC 0.86–1.54), p = 0.33. There were more cases of intracranial bleeding (37.0 versus 17.3 %, p = 0.0001) in the intra-arterial procedure group than in the intravenous group. After the exclusion of the 135 cases treated with the combination of I.V. thrombolysis and I.A. procedures, 67/189 of those treated with I.A. procedures (35.3 %) had a favourable outcome, compared to 89/324 of those treated with I.V. thrombolysis (27.4 %) (adjusted OR 1.75, 95 % CI 1.00–3.03, p = 0.05). Endovascular treatment of patients with acute ICA occlusion did not result in a better functional outcome than treatment with intravenous thrombolysis, but was associated with a higher rate of intracranial bleeding. Overall mortality was significantly reduced in patients treated with endovascular treatment but the rates of patients with severe disability or death were similar. When excluding all patients treated with the combination of I.V. thrombolysis and I.A. procedures, a potential benefit of I.A. treatment alone compared to I.V. thrombolysis was observed. © 2014, Springer-Verlag Berlin Heidelberg

Intravenous thrombolysis or endovascular therapy for acute ischemic stroke associated with cervical internal carotid artery occlusion: the ICARO-3 study.

The aim of the ICARO-3 study was to evaluate whether intra-arterial treatment, compared to intravenous thrombolysis, increases the rate of favourable functional outcome at 3 months in acute ischemic stroke and extracranial ICA occlusion. ICARO-3 was a non-randomized therapeutic trial that performed a non-blind assessment of outcomes using retrospective data collected prospectively from 37 centres in 7 countries. Patients treated with endovascular treatment within 6 h from stroke onset (cases) were matched with patients treated with intravenous thrombolysis within 4.5 h from symptom onset (controls). Patients receiving either intravenous or endovascular therapy were included among the cases. The efficacy outcome was disability at 90 days assessed by the modified Rankin Scale (mRS), dichotomized as favourable (score of 0-2) or unfavourable (score of 3-6). Safety outcomes were death and any intracranial bleeding. Included in the analysis were 324 cases and 324 controls: 105 cases (32.4 %) had a favourable outcome as compared with 89 controls (27.4 %) [adjusted odds ratio (OR) 1.25, 95 % confidence interval (CI) 0.88-1.79, p = 0.1]. In the adjusted analysis, treatment with intra-arterial procedures was significantly associated with a reduction of mortality (OR 0.61, 95 % CI 0.40-0.93, p = 0.022). The rates of patients with severe disability or death (mRS 5-6) were similar in cases and controls (30.5 versus 32.4 %, p = 0.67). For the ordinal analysis, adjusted for age, sex, NIHSS, presence of diabetes mellitus and atrial fibrillation, the common odds ratio was 1.15 (95 % IC 0.86-1.54), p = 0.33. There were more cases of intracranial bleeding (37.0 versus 17.3 %, p = 0.0001) in the intra-arterial procedure group than in the intravenous group. After the exclusion of the 135 cases treated with the combination of I.V. thrombolysis and I.A. procedures, 67/189 of those treated with I.A. procedures (35.3 %) had a favourable outcome, compared to 89/324 of those treated with I.V. thrombolysis (27.4 %) (adjusted OR 1.75, 95 % CI 1.00-3.03, p = 0.05). Endovascular treatment of patients with acute ICA occlusion did not result in a better functional outcome than treatment with intravenous thrombolysis, but was associated with a higher rate of intracranial bleeding. Overall mortality was significantly reduced in patients treated with endovascular treatment but the rates of patients with severe disability or death were similar. When excluding all patients treated with the combination of I.V. thrombolysis and I.A. procedures, a potential benefit of I.A. treatment alone compared to I.V. thrombolysis was observed

Intravenous thrombolysis or endovascular therapy for acute ischemic stroke associated with cervical internal carotid artery occlusion: the ICARO-3 study

The aim of the ICARO-3 study was to evaluate whether intra-arterial treatment, compared to intravenous thrombolysis, increases the rate of favourable functional outcome at 3 months in acute ischemic stroke and extracranial ICA occlusion. ICARO-3 was a non-randomized therapeutic trial that performed a non-blind assessment of outcomes using retrospective data collected prospectively from 37 centres in 7 countries. Patients treated with endovascular treatment within 6 h from stroke onset (cases) were matched with patients treated with intravenous thrombolysis within 4.5 h from symptom onset (controls). Patients receiving either intravenous or endovascular therapy were included among the cases. The efficacy outcome was disability at 90 days assessed by the modified Rankin Scale (mRS), dichotomized as favourable (score of 0\u20132) or unfavourable (score of 3\u20136). Safety outcomes were death and any intracranial bleeding. Included in the analysis were 324 cases and 324 controls: 105 cases (32.4 %) had a favourable outcome as compared with 89 controls (27.4 %) [adjusted odds ratio (OR) 1.25, 95 % confidence interval (CI) 0.88\u20131.79, p = 0.1]. In the adjusted analysis, treatment with intra-arterial procedures was significantly associated with a reduction of mortality (OR 0.61, 95 % CI 0.40\u20130.93, p = 0.022). The rates of patients with severe disability or death (mRS 5\u20136) were similar in cases and controls (30.5 versus 32.4 %, p = 0.67). For the ordinal analysis, adjusted for age, sex, NIHSS, presence of diabetes mellitus and atrial fibrillation, the common odds ratio was 1.15 (95 % IC 0.86\u20131.54), p = 0.33. There were more cases of intracranial bleeding (37.0 versus 17.3 %, p = 0.0001) in the intra-arterial procedure group than in the intravenous group. After the exclusion of the 135 cases treated with the combination of I.V. thrombolysis and I.A. procedures, 67/189 of those treated with I.A. procedures (35.3 %) had a favourable outcome, compared to 89/324 of those treated with I.V. thrombolysis (27.4 %) (adjusted OR 1.75, 95 % CI 1.00\u20133.03, p = 0.05). Endovascular treatment of patients with acute ICA occlusion did not result in a better functional outcome than treatment with intravenous thrombolysis, but was associated with a higher rate of intracranial bleeding. Overall mortality was significantly reduced in patients treated with endovascular treatment but the rates of patients with severe disability or death were similar. When excluding all patients treated with the combination of I.V. thrombolysis and I.A. procedures, a potential benefit of I.A. treatment alone compared to I.V. thrombolysis was observed