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1.
Diego A. Miranda Ji-Hyun Kim Long N. Nguyen Wang Cheng Bryan C. Tan Vera J. Goh Jolene S. Y. Tan Jadegoud Yaligar Bhanu Prakash KN S. Sendhil Velan Hongyan Wang David L. Silver 《The Journal of biological chemistry》2014,289(14):9560-9572
Triglycerides within the cytosol of cells are stored in a phylogenetically conserved organelle called the lipid droplet (LD). LDs can be formed at the endoplasmic reticulum, but mechanisms that regulate the formation of LDs are incompletely understood. Adipose tissue has a high capacity to form lipid droplets and store triglycerides. Fat storage-inducing transmembrane protein 2 (FITM2/FIT2) is highly expressed in adipocytes, and data indicate that FIT2 has an important role in the formation of LDs in cells, but whether FIT2 has a physiological role in triglyceride storage in adipose tissue remains unproven. Here we show that adipose-specific deficiency of FIT2 (AF2KO) in mice results in progressive lipodystrophy of white adipose depots and metabolic dysfunction. In contrast, interscapular brown adipose tissue of AF2KO mice accumulated few but large LDs without changes in cellular triglyceride levels. High fat feeding of AF2KO mice or AF2KO mice on the genetically obese ob/ob background accelerated the onset of lipodystrophy. At the cellular level, primary adipocyte precursors of white and brown adipose tissue differentiated in vitro produced fewer but larger LDs without changes in total cellular triglyceride or triglyceride biosynthesis. These data support the conclusion that FIT2 plays an essential, physiological role in fat storage in vivo. 相似文献
2.
Amir Nikou Shauna M. Dorsey Jeremy R. McGarvey Joseph H. Gorman III Jason A. Burdick James J. Pilla 《Computer methods in biomechanics and biomedical engineering》2016,19(16):1714-1720
Computational models are increasingly being used to investigate the mechanical properties of cardiac tissue. While much insight has been gained from these studies, one important limitation associated with computational modeling arises when using in vivo images of the heart to generate the reference state of the model. An unloaded reference configuration is needed to accurately represent the deformation of the heart. However, it is rare for a beating heart to actually reach a zero-pressure state during the cardiac cycle. To overcome this, a computational technique was adapted to determine the unloaded configuration of an in vivo porcine left ventricle (LV). In the current study, in vivo measurements were acquired using magnetic resonance images (MRI) and synchronous pressure catheterization in the LV (N = 5). The overall goal was to quantify the effects of using early–diastolic filling as the reference configuration (common assumption used in modeling) versus using the unloaded reference configuration for predicting the in vivo properties of LV myocardium. This was accomplished by using optimization to minimize the difference between MRI measured and finite element predicted strains and cavity volumes. The results show that when using the unloaded reference configuration, the computational method predicts material properties for LV myocardium that are softer and less anisotropic than when using the early-diastolic filling reference configuration. This indicates that the choice of reference configuration could have a significant impact on capturing the realistic mechanical response of the heart. 相似文献
3.
Proliferating cell nuclear antigen (PCNA) as a proliferative marker during embryonic and adult zebrafish hematopoiesis 总被引:4,自引:1,他引:3
Leung AY Leung JC Chan LY Ma ES Kwan TT Lai KN Meng A Liang R 《Histochemistry and cell biology》2005,124(2):105-111
We investigated the expression of proliferative cell nuclear antigen (PCNA) in zebrafish to delineate the proliferative hematopoietic
component during adult and embryonic hematopoiesis. Immunostaining for PCNA and enhanced green fluorescence protein (eGFP)
was performed in wild-type and fli1-eGFP (endothelial marker) and gata1-eGFP (erythroid cell marker) transgenic fish. Expression
of PCNA mRNA was examined in wild-type and chordin morphant embryos. In adult zebrafish kidney, the renal tubules are surrounded
by endothelial cells and it is separated into hematopoietic and excretory compartments. PCNA was expressed in hematopoietic
progenitor cells but not in mature neutrophils, eosinophils or erythroid cells. Some PCNA+ cells are scattered in the hematopoietic
compartment of the kidney while others are closely associated with renal tubular cells. PCNA was also expressed in spermatogonial
stem cells and intestine crypts, consistent with its role in cell proliferation and DNA synthesis. In embryos, PCNA is expressed
in the brain, spinal cord and intermediate cell mass (ICM) at 24 h-post fertilization. In chordin morphants, PCNA is significantly
upregulated in the expanded ICM. Therefore, PCNA can be used to mark cell proliferation in zebrafish hematopoietic tissues
and to identify a population of progenitor cells whose significance would have to be further investigated. 相似文献
4.
In this article, we report the synthesis of Na2Sr1‐x(PO4)F:Eux phosphor via a combustion method. The influence of different annealing temperatures on the photoluminescence properties was investigated. The phosphor was excited at both 254 and 393 nm. Na2Sr1‐x(PO4)F:Eux3+ phosphors emit strong orange and red color at 593 and 612 nm, respectively, under both excitation wavelengths. Na2Sr1‐x(PO4)F:Eux3+ phosphors annealed at 1050°C showed stronger emission intensity compared with 600, 900 and 1200°C. Moreover, Na2Sr1‐x(PO4)F:Eux3+ phosphor was found to be more intense when compared with commercial Y2O3:Eu3+ phosphor. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
5.
Valeria Valente Silvia A Teixeira Luciano Neder Oswaldo K Okamoto Sueli M Oba-Shinjo Suely KN Marie Carlos A Scrideli Maria L Pa?ó-Larson Carlos G Carlotti 《BMC molecular biology》2009,10(1):17
Background
Considering the broad variation in the expression of housekeeping genes among tissues and experimental situations, studies using quantitative RT-PCR require strict definition of adequate endogenous controls. For glioblastoma, the most common type of tumor in the central nervous system, there was no previous report regarding this issue. 相似文献6.
Stevenson BJ Bibby J Pignatelli P Muangnoicharoen S O'Neill PM Lian LY Müller P Nikou D Steven A Hemingway J Sutcliffe MJ Paine MJ 《Insect biochemistry and molecular biology》2011,41(7):492-502
Resistance to pyrethroid insecticides in the malaria vector Anopheles gambiae is a major threat to malaria control programmes. Cytochome P450-mediated detoxification is an important resistance mechanism. CYP6M2 is over-expressed in wild populations of permethrin resistant A. gambiae but its role in detoxification is not clear. CYP6M2 was expressed in Escherichia coli and a structural model was produced to examine its role in pyrethroid metabolism. Both permethrin and deltamethrin were metabolized. Rates were enhanced by A. gambiae cytochrome b5 with kinetic parameters of KM = 11 ± 1 ??M and kcat = 6.1 ± 0.4 per min for permethrin (1:1 cis-trans) and KM = 2.0 ± 0.3 ??M and kcat = 1.2 ± 0.1 per min for deltamethrin. Mass spectrometry and NMR analysis identified 4′-hydroxy deltamethrin and hydroxymethyl deltamethrin as major and minor deltamethrin metabolites respectively. Secondary breakdown products included cyano(3-hydroxyphenyl)methyl deltamethrate and deltamethric acid. CYP6M2 was most highly transcribed in the midgut and Malpighian tubules of adult A. gambiae, consistent with a role in detoxification. Our data indicates that CYP6M2 plays an important role in metabolic resistance to pyrethroids and thus an important target for the design of new tools to combat malaria. 相似文献
7.
Oscar Diaz-Horta Duygu Duman Joseph Foster II Asl? S?rmac? Michael Gonzalez Nejat Mahdieh Nikou Fotouhi Mortaza Bonyadi Filiz Ba?ak Cengiz Ibis Menendez Rick H. Ulloa Yvonne J. K. Edwards Stephan Züchner Susan Blanton Mustafa Tekin 《PloS one》2012,7(11)
Identification of the pathogenic mutations underlying autosomal recessive nonsyndromic hearing loss (ARNSHL) is difficult, since causative mutations in 39 different genes have so far been reported. After excluding mutations in the most common ARNSHL gene, GJB2, via Sanger sequencing, we performed whole-exome sequencing (WES) in 30 individuals from 20 unrelated multiplex consanguineous families with ARNSHL. Agilent SureSelect Human All Exon 50 Mb kits and an Illumina Hiseq2000 instrument were used. An average of 93%, 84% and 73% of bases were covered to 1X, 10X and 20X within the ARNSHL-related coding RefSeq exons, respectively. Uncovered regions with WES included those that are not targeted by the exome capture kit and regions with high GC content. Twelve homozygous mutations in known deafness genes, of which eight are novel, were identified in 12 families: MYO15A-p.Q1425X, -p.S1481P, -p.A1551D; LOXHD1-p.R1494X, -p.E955X; GIPC3-p.H170N; ILDR1-p.Q274X; MYO7A-p.G2163S; TECTA-p.Y1737C; TMC1-p.S530X; TMPRSS3-p.F13Lfs*10; TRIOBP-p.R785Sfs*50. Each mutation was within a homozygous run documented via WES. Sanger sequencing confirmed co-segregation of the mutation with deafness in each family. Four rare heterozygous variants, predicted to be pathogenic, in known deafness genes were detected in 12 families where homozygous causative variants were already identified. Six heterozygous variants that had similar characteristics to those abovementioned variants were present in 15 ethnically-matched individuals with normal hearing. Our results show that rare causative mutations in known ARNSHL genes can be reliably identified via WES. The excess of heterozygous variants should be considered during search for causative mutations in ARNSHL genes, especially in small-sized families. 相似文献
8.
Genomic analysis of the relationship between gene expression variation and DNA polymorphism in Drosophila simulans
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Background
Understanding how DNA sequence polymorphism relates to variation in gene expression is essential to connecting genotypic differences with phenotypic differences among individuals. Addressing this question requires linking population genomic data with gene expression variation.Results
Using whole genome expression data and recent light shotgun genome sequencing of six Drosophila simulans genotypes, we assessed the relationship between expression variation in males and females and nucleotide polymorphism across thousands of loci. By examining sequence polymorphism in gene features, such as untranslated regions and introns, we find that genes showing greater variation in gene expression between genotypes also have higher levels of sequence polymorphism in many gene features. Accordingly, X-linked genes, which have lower sequence polymorphism levels than autosomal genes, also show less expression variation than autosomal genes. We also find that sex-specifically expressed genes show higher local levels of polymorphism and divergence than both sex-biased and unbiased genes, and that they appear to have simpler regulatory regions.Conclusion
The gene-feature-based analyses and the X-to-autosome comparisons suggest that sequence polymorphism in cis-acting elements is an important determinant of expression variation. However, this relationship varies among the different categories of sex-biased expression, and trans factors might contribute more to male-specific gene expression than cis effects. Our analysis of sex-specific gene expression also shows that female-specific genes have been overlooked in analyses that only point to male-biased genes as having unusual patterns of evolution and that studies of sexually dimorphic traits need to recognize that the relationship between genetic and expression variation at these traits is different from the genome as a whole. 相似文献9.
Y. Yiangou P. Burnet G. Nikou B. J. Chrysanthou S. R. Bloom 《Journal of neurochemistry》1989,53(3):886-889
The primary human and porcine structure of the novel neuropeptide cerebellin is unknown. These peptides were, therefore, isolated by a combination of ion-exchange and reverse-phase chromatography using a specific radioimmunoassay against rat cerebellin. The sequences of the peptides were deduced by mass spectrometry (for both human and porcine cerebellins) and gas-phase Edman degradation (for porcine cerebellin). In both species, two molecular forms were identified. In the human, the major form corresponded to the pentadecamer [des-Ser1]-cerebellin (approximately 95% of the total) and the minor form, to the hexadecamer peptide. In the pig, however, both molecular forms were present in approximately equal amounts. The finding that the sequences of human and porcine cerebellin are identical to that of the rat suggests that strong evolutionary pressure has acted to conserve this sequence. 相似文献
10.