Aluminium nanorings: configuration deformation and structural transformation

2021 ◽  
Vol 57 (16) ◽  
pp. 2085-2088
Author(s):  
Lin Geng ◽  
Qiao-Hong Li ◽  
San-Tai Wang ◽  
Ya-Jie Liu ◽  
Wei-Hui Fang ◽  
...  

Present herein is the first time that a fatty acid is employed in the assembly of aluminium wheels. Interestingly, a structural transformation between the diol modified and monohydric alcohol is discovered.


2019 ◽  
Vol 316 (5) ◽  
pp. H1014-H1026 ◽  
Author(s):  
Helen E. Collins ◽  
Betty M. Pat ◽  
Luyun Zou ◽  
Silvio H. Litovsky ◽  
Adam R. Wende ◽  
...  

The endoplasmic reticulum/sarcoplasmic reticulum Ca2+ sensor stromal interaction molecule 1 (STIM1), a key mediator of store-operated Ca2+ entry, is expressed in cardiomyocytes and has been implicated in regulating multiple cardiac processes, including hypertrophic signaling. Interestingly, cardiomyocyte-restricted deletion of STIM1 (crSTIM1-KO) results in age-dependent endoplasmic reticulum stress, altered mitochondrial morphology, and dilated cardiomyopathy in mice. Here, we tested the hypothesis that STIM1 deficiency may also impact cardiac metabolism. Hearts isolated from 20-wk-old crSTIM1-KO mice exhibited a significant reduction in both oxidative and nonoxidative glucose utilization. Consistent with the reduction in glucose utilization, expression of glucose transporter 4 and AMP-activated protein kinase phosphorylation were all reduced, whereas pyruvate dehydrogenase kinase 4 and pyruvate dehydrogenase phosphorylation were increased, in crSTIM1-KO hearts. Despite similar rates of fatty acid oxidation in control and crSTIM1-KO hearts ex vivo, crSTIM1-KO hearts contained increased lipid/triglyceride content as well as increased fatty acid-binding protein 4, fatty acid synthase, acyl-CoA thioesterase 1, hormone-sensitive lipase, and adipose triglyceride lipase expression compared with control hearts, suggestive of a possible imbalance between fatty acid uptake and oxidation. Insulin-mediated alterations in AKT phosphorylation were observed in crSTIM1-KO hearts, consistent with cardiac insulin resistance. Interestingly, we observed abnormal mitochondria and increased lipid accumulation in 12-wk crSTIM1-KO hearts, suggesting that these changes may initiate the subsequent metabolic dysfunction. These results demonstrate, for the first time, that cardiomyocyte STIM1 may play a key role in regulating cardiac metabolism. NEW & NOTEWORTHY Little is known of the physiological role of stromal interaction molecule 1 (STIM1) in the heart. Here, we demonstrate, for the first time, that hearts lacking cardiomyocyte STIM1 exhibit dysregulation of both cardiac glucose and lipid metabolism. Consequently, these results suggest a potentially novel role for STIM1 in regulating cardiac metabolism.



2022 ◽  
Vol 2 ◽  
Author(s):  
Daniela Frasca ◽  
Maria Romero ◽  
Denisse Garcia ◽  
Alain Diaz ◽  
Bonnie B. Blomberg

We have measured the secretion of autoimmune antibodies in plasma samples and in culture supernatants of blood-derived B cells from four groups of individuals: young lean (YL), elderly lean (EL), young obese (YO) and elderly obese (EO). We found secretion comparable in YO and EL individuals, suggesting that obesity accelerates age-associated defects in circulating B cells. To define at least one possible molecular pathway involved, we used an in vitro model in which B cells from YL and EL individuals have been stimulated with the Fatty Acid (FA) palmitate, the most common saturated FA in the human body. The rationale to use palmitate is that there is a chronic increase in circulating levels of palmitate, due to increased spontaneous lipolysis occurring during aging and obesity, and this may induce autoimmune B cells. Results herein show that in vitro incubation of B cells from YL and EL individuals with the FA palmitate induces mRNA expression of T-bet, the transcription factor for autoimmune antibodies, as well as secretion of autoimmune IgG antibodies, with B cells from YL individuals looking similar to B cells from EL individuals, confirming our initial hypothesis. The generation of autoimmune B cells in the presence of the FA palmitate was found to be associated with a metabolic reprogramming of B cells from both YL and EL individuals. These results altogether show the critical role of the FA palmitate in inducing human B cell immunosenescence and show for the first time the importance of metabolic pathways in this process.



2021 ◽  
pp. 8-20

Micellar therapy has become a usefully viable treatment arm in various fields, ranging from oncology to bioimaging. As such, research leading to any improvements or adaptations in administration and techniques can have far-reaching consequences. Potential aspects of prebiotic chemistry may also be explored in such research as well. To that end, proof-of-concept experiments were performed to elucidate a possible mechanism of action for prebiotic protocell division. Representative potentially prebiotically plausible biomolecules, i.e., a fatty acid, amino acid, and nucleotide were mixed and heated in water and subjected to microscopic examination for observation of possible self-division and laboratory testing for the presence of polypeptides and polynucleotides (Biuret, MALDI mass-spec, etc.) with and without the presence of nucleotide. The results are presented for the first time here and a mechanism is proposed that best fits the data obtained. The evolutionary, e.g., prebiotic biomolecular cooperativity, and clinical, e.g., potential antineoplastic micellar/vesicular therapy, ramifications are discussed as well. Keywords: Micelle; Liposome; Protocell; MRNA; Self-division; Mechanism; Solid tumors



1982 ◽  
Vol 152 (1) ◽  
pp. 26-34
Author(s):  
M Leduc ◽  
R Kasra ◽  
J van Heijenoort

Various methods of inducing autolysis of Escherichia coli cells were investigated, some being described here for the first time. For the autolysis of growing cells only induction methods interfering with the biosynthesis of peptidoglycan were taken into consideration, whereas with harvested cells autolysis was induced by rapid osmotic or EDTA shock treatments. The highest rates of autolysis were observed after induction by moenomycin, EDTA, or cephaloridine. The different autolyses examined shared certain common properties. In particular, regardless of the induction method used, more or less extensive peptidoglycan degradation was observed, and 10(-2) M Mg2+ efficiently inhibited the autolytic process. However, for other properties a distinction was made between methods used for growing cells and those used for harvested cells. Autolysis of growing cells required RNA, protein, and fatty acid synthesis. No such requirements were observed with shock-induced autolysis performed with harvested cells. Thus, the effects of Mg2+, rifampicin, chloramphenicol, and cerulenin clearly suggest that distinct factors are involved in the control of the autolytic system of E. Coli. Uncoupling agents such as sodium azide, 2,4-dinitrophenol, and carbonyl-cyanide-m-chlorophenyl hydrazone used at their usual inhibiting concentration had no effect on the cephaloridine or shock-induced autolysis.



2020 ◽  
Author(s):  
Chi Zhang ◽  
Stephen Boppart

Abstract The mitochondrion is one of the key organelles for maintaining cellular homeostasis. External environmental stimuli and internal regulatory processes alter the metabolism and functions of mitochondria. To understand these activities of mitochondria, it is critical to probe the key metabolic molecules inside these organelles. In this study, we used label-free chemical imaging modalities including coherent anti-Stokes Raman scattering and multiphoton-excited autofluorescence to study the mitochondrial activities in living cancer cells. We found that hypothermia exposure tends to induce fatty-acid (FA) accumulation in some mitochondria of MIAPaCa-2 cells. Autofluorescence images show that the FA-accumulated mitochondria also have abnormal NADH and FAD metabolism, likely induced by the dysfunction of the electron transport chain. We also found that when the cells were re-warmed to physiological temperature after a period of hypothermia, the FA-accumulated mitochondria changed their structural features, likely caused by the mitophagy process. To the best of our knowledge, this is the first time that FA accumulation in mitochondria was observed in live cells. Our research also demonstrates that multimodal label-free chemical imaging is an attractive tool to discover abnormal functions of mitochondria at the single-organelle level and can be used to quantify the dynamic changes of this organelle under perturbative conditions.



1994 ◽  
Vol 266 (3) ◽  
pp. G372-G381 ◽  
Author(s):  
M. Armand ◽  
P. Borel ◽  
C. Dubois ◽  
M. Senft ◽  
J. Peyrot ◽  
...  

Fasting subjects were intragastrically intubated and received a coarsely emulsified test meal. Gastric aspirates were collected after 1, 2, 3, and 4 h. During digestion in the stomach, unemulsified lipids (> or = 100 microns) represented a minor fraction. A significant amount of the large 70- to 100-microns lipid droplets disappeared, and fine 1- to 10-microns droplets were generated. The median lipid droplet diameter significantly decreased (21.9 vs. 52.9 microns) after 1 h and kept intermediate values for longer periods of time. The emulsion surface area was 100-120 m2/l and was basically provided by 1- to 100-microns droplets. Lipolysis catalyzed by gastric lipase primarily occurred within the first hour of digestion (11.9%). Smaller droplets were enriched in triglyceride lipolytic products. The free fatty acid concentrations were in the range of 5.6-8.2 mM over 1-4 h. The present finding demonstrates for the first time that in the human stomach most dietary lipids are present in the form of emulsified droplets, in the range of 20-40 microns, and that gastric lipolysis can help to increase emulsification in the stomach.



2012 ◽  
Vol 7 (1) ◽  
pp. 1934578X1200700
Author(s):  
Ouassila Touafek ◽  
Zahia Kabouche ◽  
Joël Boustie ◽  
Christian Bruneau

Three long-chain unsaturated esters (1-3), a fatty acid (4), a fatty ester (5), phytone (6) and a phloroglucinol (hyperfoliatin) (7) were isolated from the light petroleum extract of the endemic species Hypericum tomentosum L. (Clusiaceae). Compound 2, 8,10,13-trimethyltetradecanoic acid (2E)-3-methylhexadec-2-enyl ester, which we named tomentosate, is reported for the first time. The structures of the identified compounds were established on the basis of physical and spectroscopic analysis, and by comparison with literature data.



1999 ◽  
Vol 24 (6) ◽  
pp. 515-523 ◽  
Author(s):  
Arend Bonen ◽  
Dragana Miskovic ◽  
Bente Kiens

Recently, a number of putative LCFA transporters have been identified: fatty acid binding protein (FABPpm), fatty acid translocase (FAT/CD36), and fatty acid transport protein (FATP). We have demonstrated, for the first time, that transcripts of all three putative LCFA transporters (FAT mRNA, FATP mRNA, and mAspAT/FABPpm mRNA) are present in human skeletal muscle. Key words: mRNA, membrane



2002 ◽  
Vol 282 (2) ◽  
pp. E318-E325 ◽  
Author(s):  
Gerjanne J. Vianen ◽  
Peter P. Obels ◽  
Guido E. E. J. M. van den Thillart ◽  
Johan Zaagsma

The regulation of triglyceride mobilization by catecholamines was investigated in the teleost fish Oreochromis mossambicus (tilapia) in vivo and in vitro. In vitro experiments were carried out with adipocytes that were isolated for the first time from fish adipose tissue. For the in vivo experiments, cannulated tilapia were exposed to stepwise decreasing oxygen levels (20, 10, and 5% air saturation; 3.9, 1.9, and 1.0 kPa Po 2, respectively), each level being maintained for 2 h. Blood samples were taken at timed intervals and analyzed for plasma lactate, glucose, free fatty acids, epinephrine, norepinephrine, and cortisol. Hypoxia exposure did not change plasma epinephrine levels. In contrast, the plasma norepinephrine concentration markedly increased at all hypoxia levels. Over the same period, plasma free fatty acid levels showed a significant continuous decrease, suggesting that norepinephrine is responsible for the reduced plasma free fatty acid concentration, presumably through inhibition of lipolysis in adipose tissue. To elucidate the mechanism, adipocytes were isolated from mesenteric adipose tissue of tilapia and incubated with 1) norepinephrine, 2) norepinephrine + phentolamine (α1,α2-antagonist), 3) isoproterenol (nonselective β-agonist), 4) isoproterenol + timolol (β1,β2-antagonist), 5) norepinephrine + timolol, and 6) BRL-35135A (β3-agonist). The results demonstrate for the first time that norepinephrine and isoproterenol suppress lipolysis in isolated adipocytes of tilapia. The effect of norepinephrine is not mediated through α2-adrenoceptors but, like isoproterenol, via β-adrenoceptors. Furthermore, this study provides strong indications that β3-adrenoceptors are involved.



Author(s):  
Xiaoyu Yang ◽  
Jing Li ◽  
Liting Zhao ◽  
Yazhuo Chen ◽  
Zhijun Cui ◽  
...  

AbstractObesity is closely associated with low-bone-mass disorder. Discoidin domain receptor 2 (DDR2) plays essential roles in skeletal metabolism, and is probably involved in fat metabolism. To test the potential role of DDR2 in fat and fat-bone crosstalk, Ddr2 conditional knockout mice (Ddr2Adipo) were generated in which Ddr2 gene is exclusively deleted in adipocytes by Adipoq Cre. We found that Ddr2Adipo mice are protected from fat gain on high-fat diet, with significantly decreased adipocyte size. Ddr2Adipo mice exhibit significantly increased bone mass and mechanical properties, with enhanced osteoblastogenesis and osteoclastogenesis. Marrow adipocyte is diminished in the bone marrow of Ddr2Adipo mice, due to activation of lipolysis. Fatty acid in the bone marrow was reduced in Ddr2Adipo mice. RNA-Seq analysis identified adenylate cyclase 5 (Adcy5) as downstream molecule of Ddr2. Mechanically, adipocytic Ddr2 modulates Adcy5-cAMP-PKA signaling, and Ddr2 deficiency stimulates lipolysis and supplies fatty acid for oxidation in osteoblasts, leading to the enhanced osteoblast differentiation and bone mass. Treatment of Adcy5 specific inhibitor abolishes the increased bone mass gain in Ddr2Adipo mice. These observations establish, for the first time, that Ddr2 plays an essential role in the crosstalk between fat and bone. Targeting adipocytic Ddr2 may be a potential strategy for treating obesity and pathological bone loss simultaneously.



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