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971.
Joya E. Nahon Menno Hoekstra Vanessa van Harmelen Patrick C.N. Rensen Ko Willems van Dijk Sander Kooijman Miranda Van Eck 《生物化学与生物物理学报:疾病的分子基础》2019,1865(2):494-501
Objective
Proteoglycan 4 (Prg4) has emerged from human association studies as a possible factor contributing to weight gain, dyslipidemia and insulin resistance. In the current study, we investigated the causal role of Prg4 in controlling lipid and glucose metabolism in mice.Methods
Prg4 knockout (KO) mice and wild-type (WT) littermates were challenged with an obesogenic high-fat diet (45% of total calories as fat) for 16?weeks. To further stimulate the development of metabolic alterations, 10% fructose water was provided starting from week 13.Results
Prg4 deficiency only tended to reduce diet-induced body weight gain, but significantly improved glucose handling (AUC: ?29%; p?<?0.05), which was also reflected by a tendency towards a reduced HOMA-IR score (?49%; p?=?0.06 as compared to WT mice). This coincided with lower hepatic expression of glycolysis (Gck: ?30%; p?<?0.05) and lipogenesis (Acc: ?21%; p?<?0.05 and Scd1: ?38%; p?<?0.001) genes, which translated in significantly lower hepatic triglyceride levels (?56%; p?<?0.001) in Prg4 KO mice as compared to WT mice. Prg4 KO mice likely had lower glucose utilization by skeletal muscle as compared to WT mice, judged by a significant reduction in the genes Glut4 (?29%; p?<?0.01), Pfkm (?21%; p?<?0.05) and Hk2 (?39%; p?<?0.001). Moreover, Prg4 KO mice showed a favorable white adipose tissue phenotype with lower uptake of triglyceride-derived fatty acids (?46%; p?<?0.05) and lower gene expression of inflammatory markers Cd68, Mcp1 and Tnfα (?65%, ?81% and ?63%, respectively; p?<?0.01) than WT mice.Conclusion
Prg4 KO mice are protected from high-fat diet-induced glucose intolerance and fatty liver disease. 相似文献972.
Cecilia Nigro Alessia Leone Michele Longo Immacolata Prevenzano Thomas H. Fleming Antonella Nicolò Luca Parrillo Rosa Spinelli Pietro Formisano Peter P. Nawroth Francesco Beguinot Claudia Miele 《生物化学与生物物理学报:疾病的分子基础》2019,1865(1):73-85
Impaired angiogenesis leads to long-term complications and is a major contributor of the high morbidity in patients with Diabetes Mellitus (DM). Methylglyoxal (MGO) is a glycolysis byproduct that accumulates in DM and is detoxified by the Glyoxalase 1 (Glo1). Several studies suggest that MGO contributes to vascular complications through mechanisms that remain to be elucidated. In this study we have clarified for the first time the molecular mechanism involved in the impairment of angiogenesis induced by MGO accumulation.Angiogenesis was evaluated in mouse aortic endothelial cells isolated from Glo1-knockdown mice (Glo1KD MAECs) and their wild-type littermates (WT MAECs). Reduction in Glo1 expression led to an accumulation of MGO and MGO-modified proteins and impaired angiogenesis of Glo1KD MAECs. Both mRNA and protein levels of the anti-angiogenic HoxA5 gene were increased in Glo1KD MAECs and its silencing improved both their migration and invasion. Nuclear NF-?B-p65 was increased 2.5-fold in the Glo1KD as compared to WT MAECs. Interestingly, NF-?B-p65 binding to HoxA5 promoter was also 2-fold higher in Glo1KD MAECs and positively regulated HoxA5 expression in MAECs. Consistent with these data, both the exposure to a chemical inhibitor of Glo1 “SpBrBzGSHCp2” (GI) and to exogenous MGO led to the impairment of migration and the increase of HoxA5 mRNA and NF-?B-p65 protein levels in microvascular mouse coronary endothelial cells (MCECs).This study demonstrates, for the first time, that MGO accumulation increases the antiangiogenic factor HoxA5 via NF-?B-p65, thereby impairing the angiogenic ability of endothelial cells. 相似文献
973.
Nathalie Chaly Sandra B. Munro Michael A. Swallow 《Journal of cellular biochemistry》1996,62(1):76-89
We have examined the composition and ultrastructure of the nuclear periphery during in vitro myogenesis of the rat myoblast cell line, L6E9. Immunofluorescence labelling and immunoblotting showed that lamins A/C and B were all present in undifferentiated cells, but that they increased significantly before extensive cell fusion had occurred, with lamins A/C increasing proportionately more. Electron microscopic observations were consistent with these results, showing an increase in the prominence of the lamina during differentiation. On the other hand, immunofluorescence labelling suggested that the P1 antigen began to disappear from the nuclear periphery as the cells were fusing, after the increase in lamin quantity, and was no longer detectable in multinucleated cells. Unexpectedly, however, P1 was readily detected in isolated nuclei, whether prepared from myoblast or differentiated cultures, as well as in both myoblast and myotube nuclear matrices. It appears probable, therefore, that the fading of P1 labelling is due to masking of the epitope by a soluble factor recruited to the nuclear periphery as cells differentiate. These data, together with evidence that the genome is substantially rearranged during L6E9 myogenesis [Chaly and Munro, 1996], suggest that L6E9 cells are a useful model system in which to study the interrelationship of nuclear envelope organization, chromatin spatial order, and nuclear function. © 1996 Wiley-Liss, Inc. 相似文献
974.
Je-Yong Choi Byung-Heon Lee Keun-Bae Song Rang-Woon Park In-San Kim Kun-Young Sohn Joon-Seung Jo Hyun-Mo Ryoo 《Journal of cellular biochemistry》1996,61(4):609-618
Bone formation involves several tightly regulated gene expression patterns of bone-related proteins. To determine the expression patterns of bone-related proteins during the MC3T3-E1 osteoblast-like cell differentiation, we used Northern blotting, enzymatic assay, and histochemistry. We found that the expression patterns of bone-related proteins were regulated in a temporal manner during the successive developmental stages including proliferation (days 4–10), bone matrix formation/maturation (days 10–16), and mineralization stages (days 16 –30). During the proliferation period (days 4–10), the expression of cell-cycle related genes such as histone H3 and H4, and ribosomal protein S6 was high. During the bone matrix formation/maturation period (days 10–16), type I collagen expression and biosynthesis, fibronectin, TGF-β1 and osteonectin expressions were high and maximal around day 16. During this maturation period, we found that the expression patterns of bone matrix proteins were two types: one is the expression pattern of type I collagen and TGF-β1, which was higher in the maturation period than that in both the proliferation and mineralization periods. The other is the expression pattern of fibronectin and osteonectin, which was higher in the maturation and mineralization periods than in the proliferation period. Alkaline phosphatase activity was high during the early matrix formation/maturation period (day 10) and was followed by a decrease to a level still significantly above the baseline level seen at day 4. During the mineralization period (days 16–30), the number of nodules and the expression of osteocalcin were high. Osteocalcin gene expression was increased up to 28 days. Our results show that the expression patterns of bone-related proteins are temporally regulated during the MC3T3-E1 cell differentiation and their regulations are unique compared with other systems. Thus, this cell line provides a useful in vitro system to study the developmental regulation of bone-related proteins in relation to the different stages during the osteoblast differentiation. © 1996 Wiley-Liss, Inc. 相似文献
975.
David K. Gardner Monika Pawelczynski Alan O. Trounson 《Molecular reproduction and development》1996,44(4):472-475
The ability of individual bovine blastocysts to survive freezing and thawing procedures was assessed by measuring glucose and pyruvate uptake and lactate production immediately before and after cryopreservation. Using glucose and pyruvate uptake and lactate production it was not possible to determine, prior to freezing, which blastocysts would be viable after thawing. However, in the 5 hr immediately after thawing, those blastocysts which expanded their blastocoel had significantly greater glucose and pyruvate uptake and lactate production (P < 0.01) than those embryos which failed to develop after a 14 hr overnight incubation. Interestingly, after thawing, two distinct populations of blastocysts existed with respect to glucose uptake and lactate production, indicating that it is possible to identify those blastocysts immediately after thawing which will reexpand. In contrast, there was a considerable degree of overlap in pyruvate uptakes between the viable and nonviable groups of embryos, indicating that this parameter could not be used to select viable embryos after thawing. There was an increase in the calculated oxidation of carbohydrates after thawing, consistent with a partial uncoupling of the inner mitochondrial membrane. In conclusion, glucose uptake and lactate production can be used to select prospectively viable blastocysts immediately after thawing, indicating that glycolysis is a major energy-generating pathway for the embryo at this time. © 1996 Wiley-Liss, Inc. 相似文献
976.
Changes in the plasma membrane of bovine sperm during heparin-induced capacitation were detected by the binding of fluorescent labeled lectins to unfixed sperm. Of the seven lectins evaluated, only binding of wheat germ agglutinin (WGA) changed with capacitation. Sperm were classified into one of 5 patterns (p1–p5) based on staining with WGA, presence or absence of propidium iodide (PI) staining (dead or alive), and acrosomal integrity (acrosome intact or reacted). The major changes associated with capacitation occurred in p1 and p2. Sperm in p1 exhibited diffuse WGA binding over the anterior sperm head, were alive, and had intact acrosomes. In p2, sperm were also acrosome intact and alive, but lacked WGA binding. When sperm were incubated under capacitating conditions with heparin, there was a decrease over time in the percentage of sperm classified in p1 (p < 0.05) and an increase in the percentage of sperm in p2 (p < 0.05). When capacitation by heparin was delayed by the inclusion of glucose in the culture medium, the same heparin-dependent changes in the percentage of sperm in p1 and p2 were delayed (p < 0.05). When capacitation by heparin was inhibited by including protamine in the culture medium, the percentage of sperm in p1 or p2 was not different from sperm incubated without heparin. Heparin-induced capacitation was associated with a loss of WGA binding to the bovine sperm head. © 1996 Wiley-Liss, Inc. 相似文献
977.
Robert H. White 《Chirality》1996,8(4):332-340
The configuration at the C-9 of methanopterin (MPT) has been determined by comparing the circular dichroism (CD) spectra of MPT and its hydrolytic fragment, 1-[4-[[1-(2-amino-7-methyl-4-hydroxy-6-pteridinyl)-ethyl]amino]phenyl]-1-deoxy-D -ribitol (HP-1), with the CD spectra of a series of model compounds of known stereochemistry. These compounds included (S)-6-[1-(4-carboxymethylanilino)ethyl]pterin, (S-6(1-hydroxyethyl)-7-methylpterin, (S-6-(1-hydroxyethyl)pterin, (R)-6-(1-phenoxyethyl)pterin, D (+)-neopterin, and L -biopterin. From this comparison it was concluded that MPT has the R configuration at C-9 and is thus configurationally related to D (+)-neopterin, which has the S configuration at C-1. From previous work establishing the relative stereochemistry at C-6, C-7, and C-9 of N5-N10-methenyl-5,6,7,8-tetrahydromethanopterin (N5-N10-methenyl-H4MPT) as R, S, and R, respectively, it is clear that the remaining asymmetric carbons at C-6 and C-7 of H4MPT have the S and S configuration, respectively. Comparison of these latter two positions to the equivalent carbons in 5,6,7,8-tetrahydrofolate (H4folate) show that the steps involved in the biological reduction of MPT to H4MPT occur with the same stereochemical outcome as those involved in the biological reduction of folate to H4folate. © 1996 Wiley-Liss, Inc. 相似文献
978.
Mohammad A. Ilian Barney R. Sparrow Byung-Woo Ryu Daniel P. Selivonchick Henry W. Schaup 《Journal of biochemical and molecular toxicology》1996,11(1):51-56
The activity and level of hepatic pyruvate carboxylase (PC) has been reported to be altered by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) treatment in mice. If alteration in PC level/activity by TCDD influences TCDD toxicity, one would expect to observe an early post-exposure reduction in PC mRNA. To examine the molecular events responsible for the alteration of PC activity in livers of TCDD-treated mice, we designed a synthetic DNA oligonucleotide probe specific for PC mRNA. Northern blot analysis on RNA extracts from hepatic tissue at various times and doses post-TCDD exposure were done. Furthermore, to elucidate the role of the dioxin Ah locus on alterations of PC activity by TCDD, we utilized C57BL/6J (Ahb/b, Ah high TCDD affinity) mice and a congenic (Ahd/d, Ah low TCDD affinity) mouse strain. At 8 days post TCDD treatment, a dose-dependent reduction of hepatic PC mRNA levels was observed in Ahb/b mice. The response, reduction in PC mRNA levels, in the Ahb/b strain was about 10-fold greater than that of comparably exposed congenic Ahd/d mice. These results indicate that previously reported reductions in PC activity/level by TCDD treatment of mice is a consequence of a reduction in PC mRNA levels and that the effect requires a competent Ah receptor. © 1996 John Wiley & Sons, Inc. 相似文献
979.
Hitoshi Ashida Essam Enan Fumio Matsumura 《Journal of biochemical and molecular toxicology》1996,11(6):269-278
The effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on lipid peroxidation, 3H-Me-glucose (3H-Me-glu), and 14C-dehydroascorbic acid (14C-DHA) uptakes were studied in adipose tissue of male guinea pig. Under in vitro test conditions, using isolated adipose tissue in a culture medium (explant culture), TCDD reduced the uptake of 3H-Me-glu and 14C-DHA in a dose- and time-dependent fashion. The IC50 values of TCDD's action were 0.04 and 2 nM on 14C-DHA and 3H-Me-glu uptakes, respectively. TCDD (10 nM) also suppressed glucose transporting activity within 15 minutes in explant-cultured adipocytes. Cytochalasin B (CB) and nonlabeled D-glucose inhibited 14C-DHA uptake also in a dose-dependent manner. In addition, TCDD was found to induce lipid peroxidation in ex-plant-cultured adipose tissue. This effect of TCDD was similar to that of a typical lipid peroxidation inducer, CCl4, and it was dose and time dependent. TCDD caused a statistically significant rise in lipid peroxidation at a concentration as low as 0.1 nM after 60 minutes of treatment in explant culture. Unexpectedly, the Ah receptor partial antagonists, 4,7-phenanthroline and α-naphthoflavone, did not fully antagonize TCDD-induced lipid peroxidation in explant-cultured adipocytes. In vivo treatment of TCDD also induced lipid peroxidation. Among seven organs of male guinea pig tested, the levels of lipid peroxidation in adipose tissue and in liver increased at 1 and 40 days following a single i.p. dose of TCDD (1 μg/kg). The results of an in vivo time-course study indicated that such an effect of TCDD was most pronounced after 40 days of treatment. Finally, we have tested the protective role of some antioxidants on TCDD-induced lipid peroxidation under explant-culture conditions. The results indicated that DHA, but not ascorbic acid, could completely abolish TCDD-induced lipid peroxidation. The protective effect of DHA on TCDD-induced lipid peroxidation was stronger than that of α-tocopherol and uric acid, and this effect was blocked by CB. We conclude from these studies that TCDD acts in this guinea pig tissue through two different routes: one is the Ah receptor-dependent route causing the reduction of the level of glucose transporters and subsequent decrease of cellular uptake of DHA and the other, the Ah receptor-independent route causing the overall lipid peroxidation. Nevertheless, it appears likely that both events are antagonized by DHA. © 1997 John Wiley & Sons, Inc. J Biochem Toxicol 11: 269–278, 1997. 相似文献
980.
Yan-ming Liu Yue Cao Ping-sen Zhao Liang-yin Wu Ya-min Lu Yu-long Wang Jia-feng Zhao Xin-guang Liu 《International journal of biological sciences》2022,18(2):637
Background: Circular RNAs (circRNAs), which generally act as microRNA (miRNA) sponges to competitively regulate the downstream target genes of miRNA, play an essential role in cancer biology. However, few studies have been reported on the role of circRNA based competitive endogenous RNA (ceRNA) network in hepatocellular carcinoma (HCC). Herein, we aimed to screen and establish the circRNA/miRNA/mRNA networks related to the prognosis and progression of HCC and further explore the underlying mechanisms of tumorigenesis.Methods: GEO datasets , GSE97332, and GSE108724 were utilized to screen the differentially expressed circRNAs (DE-circRNAs), DE-miRNAs, and DEmRNAs between HCC and matched para-carcinoma tissues. After six RNA-RNA predictions and five intersections between DE-RNAs and predicted RNAs, the survival-related RNAs were screened by the ENCORI analysis tool. The ceRNA networks were constructed using Cytoscape software, based on two models of up-regulated circRNA/down-regulated miRNA/up-regulated mRNA and down-regulated circRNA/up-regulated miRNA/down-regulated mRNA. The qRT-PCR assay was utilized for detecting the RNA expression levels in HCC cells and tissues. The apoptosis, Edu, wound healing, and transwell assays were performed to evaluate the effect of miR-106b-5p productions on the proliferation, invasion, and metastasis of HCC cells. In addition, the clone formation, cell cycle, and nude mice xenograft tumor assays were used to investigate the influence of hsa_circ_0001495 (circCCNB1) silencing and overexpression on the proliferation of HCC cells in vitro and in vivo. Furthermore, the mechanism of downstream gene DYNC1I1 and AKT/ERK signaling pathway via the circCCNB1/miR-106b-5p/GPM6A network in regulating the cell cycle was also explored.Results: Twenty DE-circRNAs with a genomic length less than 2000bp, 11 survival-related DE-miRNAs, and 61 survival-related DE-mRNAs were screened out and used to construct five HCC related ceRNA networks. Then, the circCCNB1/miR-106b-5p/GPM6A network was randomly selected for subsequent experimental verification and mechanism exploration at in vitro and in vivo levels. The expression of circCCNB1 and GPM6A were significantly down-regulated in HCC cells and cancer tissues, while miR-106b-5p expression was up-regulated. After transfections, miR-106b-5p mimics notably enhanced the proliferation, invasion, and metastasis of HCC cells, while the opposite was seen with miR-105b-5p inhibitor. In addition, circCCNB1 silencing promoted the clone formation ability, the cell cycle G1-S transition, and the growth of xenograft tumors of HCC cells via GPM6A downregulation. Subsequently, under-expression of GPM6A increased DYNC1I1 expression and activated the phosphorylation of the AKT/ERK pathway to regulate the HCC cell cycle.Conclusions: We demonstrated that circCCNB1 silencing promoted cell proliferation and metastasis of HCC cells by weakening sponging of oncogenic miR-106b-5p to induce GPM6A underexpression. DYNC1I1 gene expression was up-regulated and further led to activation of the AKT/ERK signaling pathway. GSE101728相似文献