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51.
Evelyn Walenta Ariane R. Pessentheiner Helmut J. Pelzmann Alexander Deutsch Madeleine Goeritzer Dagmar Kratky Hubert Hackl Da Young Oh Andreas Prokesch Juliane G. Bogner-Strauss 《PloS one》2013,8(11)
Our knowledge about adipocyte metabolism and development is steadily growing, yet many players are still undefined. Here, we show that α/β-hydrolase domain containing protein 15 (Abhd15) is a direct and functional target gene of peroxisome proliferator-activated receptor gamma (PPARγ), the master regulator of adipogenesis. In line, Abhd15 is mainly expressed in brown and white adipose tissue and strongly upregulated during adipogenesis in various murine and human cell lines. Stable knockdown of Abhd15 in 3T3-L1 cells evokes a striking differentiation defect, as evidenced by low lipid accumulation and decreased expression of adipocyte marker genes. In preconfluent cells, knockdown of Abhd15 leads to impaired proliferation, which is caused by apoptosis, as we see an increased SubG1 peak, caspase 3/7 activity, and BAX protein expression as well as a reduction in anti-apoptotic BCL-2 protein. Furthermore, apoptosis-inducing amounts of palmitic acid evoke a massive increase of Abhd15 expression, proposing an apoptosis-protecting role for ABHD15. On the other hand, in mature adipocytes physiological (i.e. non-apoptotic) concentrations of palmitic acid down-regulate Abhd15 expression. Accordingly, we found that the expression of Abhd15 in adipose tissue is reduced in physiological situations with high free fatty acid levels, like high-fat diet, fasting, and aging as well as in genetically obese mice. Collectively, our results position ABHD15 as an essential component in the development of adipocytes as well as in apoptosis, thereby connecting two substantial factors in the regulation of adipocyte number and size. Together with its intricate regulation by free fatty acids, ABHD15 might be an intriguing new target in obesity and diabetes research. 相似文献
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53.
Won-Kyung Hong Sun-Yeon Heo Baek-Rock Oh Chul Ho Kim Jung-Hoon Sohn Ji-Won Yang Akihiko Kondo Jeong-Woo Seo 《Bioprocess and biosystems engineering》2013,36(9):1191-1197
In the present study, we established a genetic system for manipulating the oleaginous heterotrophic microalgae Aurantiochytrium sp. KRS101, using cycloheximide resistance as the selectable marker. The gene encoding ribosomal protein L44 (RPL44) of Aurantiochytrium sp. KRS101 was first identified and characterized. Proline 56 was replaced with glutamine, affording cycloheximide resistance to strains encoding the mutant protein. This resistance served as a novel selection marker. The gene encoding the Δ12-fatty acid desaturase of Mortierella alpina, used as a reporter, was successfully introduced into chromosomal DNA of Aurantiochytrium sp. KRS101 via 18S rDNA-targeted homologous recombination. Enzymatic conversion of oleic acid (C18:1) to linoleic acid (C18:2) was detected in transformants but not in the wild-type strain. 相似文献
54.
Several plant CDPKs were recently shown to be dual specificity kinases rather than Ser/Thr kinases as traditionally classified by sequence analysis. In the present study we confirm the autophosphorylation of recombinant soybean His6-GmCDPKβ at the Tyr-24 site using sequence- and modification- specific antibodies. Homology modeling of soybean CDPKβ based on recent structures determined for several apicomplexan CDPKs suggested that phosphotyrosine-24 may be inaccessible to phosphatases. However, we report that dephosphorylation of CDPKβ by the protein tyrosine phosphatase 1B, PTP1B, was not restricted in the presence of calcium. Thus, despite conformational changes likely associated with calcium binding to the CDPKs, phosphotyrosine sites remain fully accessible to dephosphorylation suggesting the possibility of conformational breathing and flexing. 相似文献
55.
Hyun-Ju Cho Hyun-Jai Cho Ho-Jae Lee Myung-Kang Song Ji-Yun Seo Yeon-Hee Bae Ju-Young Kim Hae-Young Lee Whal Lee Bon-Kwon Koo Byung-Hee Oh Young-Bae Park Hyo-Soo Kim 《PLoS biology》2013,11(4)
Vascular calcification is an advanced feature of atherosclerosis for which no effective therapy is available. To investigate the modulation or reversal of calcification, we identified calcifying progenitor cells and investigated their calcifying/decalcifying potentials. Cells from the aortas of mice were sorted into four groups using Sca-1 and PDGFRα markers. Sca-1+ (Sca-1+/PDGFRα+ and Sca-1+/PDGFRα−) progenitor cells exhibited greater osteoblastic differentiation potentials than Sca-1− (Sca-1−/PDGFRα+ and Sca-1−/PDGFRα−) progenitor cells. Among Sca-1+ progenitor populations, Sca-1+/PDGFRα− cells possessed bidirectional differentiation potentials towards both osteoblastic and osteoclastic lineages, whereas Sca-1+/PDGFRα+ cells differentiated into an osteoblastic lineage unidirectionally. When treated with a peroxisome proliferator activated receptor γ (PPARγ) agonist, Sca-1+/PDGFRα− cells preferentially differentiated into osteoclast-like cells. Sca-1+ progenitor cells in the artery originated from the bone marrow (BM) and could be clonally expanded. Vessel-resident BM-derived Sca-1+ calcifying progenitor cells displayed nonhematopoietic, mesenchymal characteristics. To evaluate the modulation of in vivo calcification, we established models of ectopic and atherosclerotic calcification. Computed tomography indicated that Sca-1+ progenitor cells increased the volume and calcium scores of ectopic calcification. However, Sca-1+/PDGFRα− cells treated with a PPARγ agonist decreased bone formation 2-fold compared with untreated cells. Systemic infusion of Sca-1+/PDGFRα− cells into Apoe−/− mice increased the severity of calcified atherosclerotic plaques. However, Sca-1+/PDGFRα− cells in which PPARγ was activated displayed markedly decreased plaque severity. Immunofluorescent staining indicated that Sca-1+/PDGFRα− cells mainly expressed osteocalcin; however, activation of PPARγ triggered receptor activator for nuclear factor-κB (RANK) expression, indicating their bidirectional fate in vivo. These findings suggest that a subtype of BM-derived and vessel-resident progenitor cells offer a therapeutic target for the prevention of vascular calcification and that PPARγ activation may be an option to reverse calcification. 相似文献
56.
Yuwon Park Nam‐Soon Choi Sangjin Park Seung Hee Woo Soojin Sim Bo Yun Jang Seung M. Oh Soojin Park Jaephil Cho Kyu Tae Lee 《Liver Transplantation》2013,3(2):206-212
Remarkable improvements in the electrochemical performance of Si materials for Li‐ion batteries have been recently achieved, but the inherent volume change of Si still induces electrode expansion and external cell deformation. Here, the void structure in Si‐encapsulating hollow carbons is optimized in order to minimize the volume expansion of Si‐based anodes and improve electrochemical performance. When compared to chemical etching, the hollow structure is achieved via electroless etching is more advanced due to the improved electrical contact between carbon and Si. Despite the very thick electrodes (30 ~ 40 μm), this results in better cycle and rate performances including little capacity fading over 50 cycles and 1100 mA h g?1 at 2C rate. Also, an in situ dilatometer technique is used to perform a comprehensive study of electrode thickness change, and Si‐encapsulating hollow carbon mitigates the volume change of electrodes by adoption of void space, resulting in a small volume increase of 18% after full lithiation corresponding with a reversible capacity of about 2000 mA h g?1. 相似文献
57.
Hari Datta Bhattarai Babita Paudel Kim Il Chan Hyuncheol Oh Joung Han Yim 《Phytochemistry letters》2013,6(4):536-538
A new fused tetracyclic heterocyclic compound, (4bR,10bR)-4b-hydroxy-10b,12-dihydrodibenzo[c,h][2,6]naphthyridine-5,11(4bH,6H)-dione (1), and a known compound, butyl 2-[(benzoyloxy)methyl]benzoate, spatozoate 2, were isolated from the broth culture of Serratia sp. PAMC 25557. The structure of 1 was determined by analyzing spectroscopic data. Compound 1 did not exhibit antimicrobial activity against Escherichia coli, Staphylococcus aureus, or Candida albicans. In addition, up to 100 μg/ml compound 1 did not show any toxicity against Artemia salina larvae. However, compound 1 showed DPPH free radical scavenging activity (IC50 = 16.7 ± 0.34 μg/ml). This was the first report of spatozoate isolation from bacterial sources. 相似文献
58.
Emmanuel S. Buys Yu-Chieh Ko Clemens Alt Sarah R. Hayton Alexander Jones Laurel T. Tainsh Ruiyi Ren Andrea Giani Maeva Clerté Emma Abernathy Robert E. T. Tainsh Dong-Jin Oh Rajeev Malhotra Pankaj Arora Nadine de Waard Binglan Yu Raphael Turcotte Daniel Nathan Marielle Scherrer-Crosbie Stephanie J. Loomis Jae H. Kang Charles P. Lin Haiyan Gong Douglas J. Rhee Peter Brouckaert Janey L. Wiggs Meredith S. Gregory Louis R. Pasquale Kenneth D. Bloch Bruce R. Ksander 《PloS one》2013,8(3)
Primary open angle glaucoma (POAG) is a leading cause of blindness worldwide. The molecular signaling involved in the pathogenesis of POAG remains unknown. Here, we report that mice lacking the α1 subunit of the nitric oxide receptor soluble guanylate cyclase represent a novel and translatable animal model of POAG, characterized by thinning of the retinal nerve fiber layer and loss of optic nerve axons in the context of an open iridocorneal angle. The optic neuropathy associated with soluble guanylate cyclase α1–deficiency was accompanied by modestly increased intraocular pressure and retinal vascular dysfunction. Moreover, data from a candidate gene association study suggests that a variant in the locus containing the genes encoding for the α1 and β1 subunits of soluble guanylate cyclase is associated with POAG in patients presenting with initial paracentral vision loss, a disease subtype thought to be associated with vascular dysregulation. These findings provide new insights into the pathogenesis and genetics of POAG and suggest new therapeutic strategies for POAG. 相似文献
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60.
Chang-Mo Oh Kyu-Won Jung Young-Joo Won Aesun Shin Hyun-Joo Kong Jae Kwan Jun Sang-yoon Park 《PloS one》2013,8(8)