61 research outputs found
Loss-of-function mutations in Lysyl-tRNA synthetase cause various leukoencephalopathy phenotypes
Objective: To expand the clinical spectrum of lysyl-tRNA synthetase (KARS) geneârelated diseases, which so far includes Charcot-Marie-Tooth disease, congenital visual impairment and microcephaly, and nonsyndromic hearing impairment.
Methods: Whole-exome sequencing was performed on index patients from 4 unrelated families with leukoencephalopathy. Candidate pathogenic variants and their cosegregation were confirmed by Sanger sequencing. Effects of mutations on KARS protein function were examined by aminoacylation assays and yeast complementation assays.
Results: Common clinical features of the patients in this study included impaired cognitive ability, seizure, hypotonia, ataxia, and abnormal brain imaging, suggesting that the CNS involvement is the main clinical presentation. Six previously unreported and 1 known KARS mutations were identified and cosegregated in these families. Two patients are compound heterozygous for missense mutations, 1 patient is homozygous for a missense mutation, and 1 patient harbored an insertion mutation and a missense mutation. Functional and structural analyses revealed that these mutations impair aminoacylation activity of lysyl-tRNA synthetase, indicating that de- fective KARS function is responsible for the phenotypes in these individuals.
Conclusions: Our results demonstrate that patients with loss-of-function KARS mutations can manifest CNS disorders, thus broadening the phenotypic spectrum associated with KARS-related disease
CONSIDERATIONS ON ENERGETIC CROPS POTENTIAL
In order to breathe fresh and clean air, nature and terrestrial atmosphere should be preserved and protected. Carbon emissions represent one of the main enemies of air quality. Recently, carbon emissions have surpassed all the predictions because the excessive industrialization, becoming the determining factor for global warming. A viable alternative to carbon emissions reduction is the utilization of energy sources that can diminish the noxious substances emissions up to zero. This can be done by using the power of wind, sun, water, energy plants, etc. Among the energetic potential plants, the biomass is obtained- a form of renewable energy which final product is biofuel
Dual-5Îą-Reductase Inhibition Promotes Hepatic Lipid Accumulation in Man
Context:
5Îą-Reductase 1 and 2 (SRD5A1, SRD5A2) inactivate cortisol to 5Îą-dihydrocortisol in addition to their role in the generation of DHT. Dutasteride (dual SRD5A1 and SRD5A2 inhibitor) and finasteride (selective SRD5A2 inhibitor) are commonly prescribed, but their potential metabolic effects have only recently been identified.
Objective:
Our objective was to provide a detailed assessment of the metabolic effects of SRD5A inhibition and in particular the impact on hepatic lipid metabolism.
Design:
We conducted a randomized study in 12 healthy male volunteers with detailed metabolic phenotyping performed before and after a 3-week treatment with finasteride (5 mg od) or dutasteride (0.5 mg od). Hepatic magnetic resonance spectroscopy (MRS) and two-step hyperinsulinemic euglycemic clamps incorporating stable isotopes with concomitant adipose tissue microdialysis were used to evaluate carbohydrate and lipid flux. Analysis of the serum metabolome was performed using ultra-HPLC-mass spectrometry.
Setting:
The study was performed in the Wellcome Trust Clinical Research Facility, Queen Elizabeth Hospital, Birmingham, United Kingdom.
Main Outcome Measure:
Incorporation of hepatic lipid was measured with MRS.
Results:
Dutasteride, not finasteride, increased hepatic insulin resistance. Intrahepatic lipid increased on MRS after dutasteride treatment and was associated with increased rates of de novo lipogenesis. Adipose tissue lipid mobilization was decreased by dutasteride. Analysis of the serum metabolome demonstrated that in the fasted state, dutasteride had a significant effect on lipid metabolism.
Conclusions:
Dual-SRD5A inhibition with dutasteride is associated with increased intrahepatic lipid accumulation.
- See more at: http://press.endocrine.org/doi/10.1210/jc.2015-2928#sthash.KmmY91Iw.dpu
Susceptibility to fatty acid-induced β-cell dysfunction is enhanced in prediabetic diabetes-prone biobreeding rats: A potential link between β-cell lipotoxicity and islet inflammation
β-Cell lipotoxicity is thought to play an important role in the development of type 2 diabetes. However, no study has examined its role in type 1 diabetes, which could be clinically relevant for slow-onset type 1 diabetes. Reports of enhanced cytokine toxicity in fat-laden islets are consistent with the hypothesis that lipid and cytokine toxicity maybe synergistic. Thus, β-cell lipotoxicity could be enhanced in models of autoimmune diabetes. To determine this, we examined the effects of prolonged free fatty acids elevation on β-cell secretory function in the prediabetic diabetes-prone BioBreeding (dp-BB) rat, its diabetes-resistant BioBreeding (dr-BB) control, and normal Wistar-Furth (WF) rats. Rats received a 48-h iv infusion of saline or Intralipid plus heparin (IH) (to elevate free fatty acid levels âź2-fold) followed by hyperglycemic clamp or islet secretion studies ex vivo. IH significantly decreased β-cell function, assessed both by the disposition index (insulin secretion corrected for IH-induced insulin resistance) and in isolated islets, in dp-BB, but not in dr-BB or WF, rats, and the effect of IH was inhibited by the antioxidant N-acetylcysteine. Furthermore, IH significantly increased islet cytokine mRNA and plasma cytokine levels (monocyte chemoattractant protein-1 and IL-10) in dp-BB, but not in dr-BB or WF, rats. All dp-BB rats had mononuclear infiltration of islets, which was absent in dr-BB and WF rats. In conclusion, the presence of insulitis was permissive for IH-induced β-cell dysfunction in the BB rat, which suggests a link between β-cell lipotoxicity and islet inflammation. Copyright Š 2013 by The Endocrine Society
ASPECTS REGARDING THE CULTIVATION OF TOPINAMBOUR
Jerusalem artichoke (Helianthus tuberosusL.) is a perennial plant whose tubers containinulin,which can be used as raw material for healthy products, sweeteners, bioethanol and animal feed. The objective of this paper is o present some consideration about this very important plant for agriculture, medicine, food and health
Substrate interaction defects in histidylâ tRNA synthetase linked to dominant axonal peripheral neuropathy
Histidylâ tRNA synthetase (HARS) ligates histidine to cognate tRNA molecules, which is required for protein translation. Mutations in HARS cause the dominant axonal peripheral neuropathy Charcotâ Marieâ Tooth disease type 2W (CMT2W); however, the precise molecular mechanism remains undefined. Here, we investigated three HARS missense mutations associated with CMT2W (p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly). The three mutations localize to the HARS catalytic domain and failed to complement deletion of the yeast ortholog (HTS1). Enzyme kinetics, differential scanning fluorimetry (DSF), and analytical ultracentrifugation (AUC) were employed to assess the effect of these substitutions on primary aminoacylation function and overall dimeric structure. Notably, the p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly HARS substitutions all led to reduced aminoacylation, providing a direct connection between CMT2Wâ linked HARS mutations and loss of canonical ARS function. While DSF assays revealed that only one of the variants (p.Val155Gly) was less thermally stable relative to wildâ type, all three HARS mutants formed stable dimers, as measured by AUC. Our work represents the first biochemical analysis of CMTâ associated HARS mutations and underscores how loss of the primary aminoacylation function can contribute to disease pathology.Diseaseâ causing variants in multiple aminoacylâ tRNA synthetase genes have been linked to the dominant inherited peripheral neuropathy Charcot Marie Tooth (CMT) disease. Here, we employed yeast complementation, enzyme kinetics, differential scanning fluorimetry (DSF), and analytical ultra centrifugation (AUC) to investigate three histidylâ tRNA synthetase (HARS) missense mutations associated with CMT2W (p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly). The mutant substitutions all led to reduced catalytic activity and poorer histidine and ATP binding, illustrating how loss of primary aminoacylation function can contribute to disease pathology.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142441/1/humu23380_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142441/2/humu23380.pd
EQUIPMENT FOR EXTRACTING AND PLANTING EARTH BALE ROOT PLANTS
Trees are one of the biggestĂÂ organisms living on the planet and their role is extremely important, namely that to maintain the purity of air we breathe, improve water quality, prevent soil erosion, reduce noise level, ensure food, construction materials and eventually people comfort. Plantation and transplantation of trees by means of specialized equipmentĂÂ in comparison with human force leads to an increased planting speed and higher yield, economically speaking. This paper is designed to present different constructive variants, at world level, of equipment for extracting and planting trees with earth bale at their roots, necessary for afforestation, landscape design, tree nurseries
The REgolith X-Ray Imaging Spectrometer (REXIS) for OSIRIS-REx: identifying regional elemental enrichment on asteroids
The OSIRIS-REx Mission was selected under the NASA New Frontiers program and is scheduled for launch in September of 2016 for a rendezvous with, and collection of a sample from the surface of asteroid Bennu in 2019. 101955 Bennu (previously 1999 RQ36) is an Apollo (near-Earth) asteroid originally discovered by the LINEAR project in 1999 which has since been classified as a potentially hazardous near-Earth object. The REgolith X-Ray Imaging Spectrometer (REXIS) was proposed jointly by MIT and Harvard and was subsequently accepted as a student led instrument for the determination of the elemental composition of the asteroid's surface as well as the surface distribution of select elements through solar induced X-ray fluorescence. REXIS consists of a detector plane that contains 4 X-ray CCDs integrated into a wide field coded aperture telescope with a focal length of 20 em for the detection of regions with enhanced abundance in key elements at 50 m scales. Elemental surface distributions of approximately 50-200 m scales can be detected using the instrument as a simple collimator. An overview of the observation strategy of the REXIS instrument and expected performance are presented here.Astronom
Biallelic VARS variants cause developmental encephalopathy with microcephaly that is recapitulated in vars knockout zebrafish
Aminoacyl tRNA synthetases (ARSs) link specific amino acids with their cognate transfer RNAs in a critical early step of protein translation. Mutations in ARSs have emerged as a cause of recessive, often complex neurological disease traits. Here we report an allelic series consisting of seven novel and two previously reported biallelic variants in valyl-tRNA synthetase (VARS) in ten patients with a developmental encephalopathy with microcephaly, often associated with early-onset epilepsy. In silico, in vitro, and yeast complementation assays demonstrate that the underlying pathomechanism of these mutations is most likely a loss of protein function. Zebrafish modeling accurately recapitulated some of the key neurological disease traits. These results provide both genetic and biological insights into neurodevelopmental disease and pave the way for further in-depth research on ARS related recessive disorders and precision therapies
NADPH Oxidase 2-Derived Reactive Oxygen Species Mediate FFAs-Induced Dysfunction and Apoptosis of β-Cells via JNK, p38 MAPK and p53 Pathways
Dysfunction of β-cell is one of major characteristics in the pathogenesis of type 2 diabetes. The combination of obesity and type 2 diabetes, characterized as âdiabesityâ, is associated with elevated plasma free fatty acids (FFAs). Oxidative stress has been implicated in the pathogenesis of FFA-induced β-cell dysfunction. However, molecular mechanisms linking between reactive oxygen species (ROS) and FFA-induced β-cell dysfunction and apoptosis are less clear. In the present study, we test the hypothesis that NOX2-derived ROS may play a critical role in dysfunction and apoptosis of β-cells induced by FFA. Our results show that palmitate and oleate (0.5 mmol/L, 48 h) induced JNK activation and AKT inhibition which resulted in decreased phosphorylation of FOXO1 following nuclear localization and the nucleocytoplasmic translocation of PDX-1, leading to the reducing of insulin and ultimately dysfunction of pancreatic NIT-1 cells. We also found that palmitate and oleate stimulated apoptosis of NIT-1 cells through p38MAPK, p53 and NF-ÎşB pathway. More interestingly, our data suggest that suppression of NOX2 may restore FFA-induced dysfunction and apoptosis of NIT-1 cells. Our findings provide a new insight of the NOX2 as a potential new therapeutic target for preservation of β-cell mass and function
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