共查询到20条相似文献，搜索用时 31 毫秒
1.
Natalia V. Dolgova Susan Nehzati Sanjukta Choudhury Tracy C. MacDonald Nathan R. Regnier Andrew M. Crawford Olena Ponomarenko Graham N. George Ingrid J. Pickering 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(11):2383-2392
Background
Selenium is an essential element with a rich and varied chemistry in living organisms. It plays a variety of important roles ranging from being essential in enzymes that are critical for redox homeostasis to acting as a deterrent for herbivory in hyperaccumulating plants. Despite its importance there are many open questions, especially related to its chemistry in situ within living organisms.Scope of review
This review discusses X-ray spectroscopy and imaging of selenium in biological samples, with an emphasis on the methods, and in particular the techniques of X-ray absorption spectroscopy (XAS) and X-ray fluorescence imaging (XFI). We discuss the experimental methods and capabilities of XAS and XFI, and review their advantages and their limitations. A perspective on future possibilities and next-generation of experiments is also provided.Major conclusions
XAS and XFI provide powerful probes of selenium chemistry, together with unique in situ capabilities. The opportunities and capabilities of the next generation of advanced X-ray spectroscopy experiments are particularly exciting.General significance
XAS and XFI provide versatile tools that are generally applicable to any element with a convenient X-ray absorption edge, suitable for investigating complex systems essentially without pre-treatment. 相似文献2.
Yuta Murakami Koichi Takahashi Kyoka Hoshi Hiromi Ito Mayumi Kanno Kiyoshi Saito Kenneth Nollet Yoshiki Yamaguchi Masakazu Miyajima Hajime Arai Yasuhiro Hashimoto Tatsuo Mima 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(8):1835-1842
Background
Spontaneous intracranial hypotension (SIH) is caused by cerebrospinal fluid (CSF) leakage. Definitive diagnosis can be difficult by clinical examinations and imaging studies.Methods
SIH was diagnosed with the following criteria: (i) evidence of CSF leakage by cranial magnetic resonance imaging (MRI) findings of intracranial hypotension and/or low CSF opening pressure; (ii) no recent history of dural puncture. We quantified CSF proteins by ELISA or Western blotting.Results
Comparing with non-SIH patients, SIH patients showed significant increase of brain-derived CSF glycoproteins such as lipocalin-type prostaglandin D synthase (L-PGDS), soluble protein fragments generated from amyloid precursor protein (sAPP) and “brain-type” transferrin (Tf). Serum-derived proteins such as albumin, immunoglobulin G, and serum Tf were also increased. A combination of L-PGDS and brain-type Tf differentiated SIH from non-SIH with sensitivity 94.7% and specificity 72.6%.Conclusion
L-PGDS and brain-type Tf can be biomarkers for diagnosing SIH.General significance
L-PGDS and brain-type Tf biosynthesized in the brain appears to be markers for abnormal metabolism of CSF. 相似文献3.
Petr Herman Aleš Holoubek Barbora Brodska 《Biochimica et Biophysica Acta (BBA)/General Subjects》2019,1863(1):266-277
Background
EGFP is a fluorescent tag extensively used in biological and biomedical research. Over the years many researches have gathered collections of cell lines bearing specific EGFP-tagged proteins. Despite its popularity some photochemical properties of EGFP remain undocumented and unused. We report on so far unexplored lifetime photoconversion of EGFP usable in FLIM.Methods
Fluorescence lifetime imaging and spectral FLIM has been used for characterization of the EGFP photoconversion and protein tracking.Result
Our data suggest that EGFP can be permanently photoconverted to a short-fluorescence-lifetime form (PC-EGFP) by intense blue irradiation. PC-EGFP cannot be reverted back by 405?nm light and exhibits the same spectral emission properties with blue-shifted absorption compared to the unconverted EGFP. Fluorescence of PC-EGFP is pH-independent and the photoconversion efficiency decreases with the solvent viscosity. Utilization of the EGFP photoconversion was demonstrated by tracking of a nucleophosmin mutant in live HEK-293?T cells during its cytoplasm-nuclear relocalization induced by Leptomycin B.Conclusions
Besides potential FLIM artifacts caused by an unintended EGFP photoconversion, the controlled photoconversion turns EGFP to an excellent tool for kinetic FLIM applications. Since the photoconversion occurs in the lifetime domain, PC-EGFP can be easily distinguished from the unconverted tag by time-resolved detection while all other spectral channels stay free for multicolor labeling.General significance
The reported lifetime photoconversion lines up EGFP with other photoconvertible fluorescent proteins with special advantage for fluorescence lifetime imaging where lifetime-photoconvertible labels are scarce. 相似文献4.
5.
Meenakshi Sharma Dinesh Kumar Krishna Mohan Poluri 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(4):924-935
Background
Characterization of partially collapsed protein conformations at atomic level is a daunting task due to their inherent flexibility and conformational heterogeneity. T7 bacteriophage endolysin (T7L) is a single-domain amidase that facilitates the lysis of Gram-negative bacteria. T7L exhibits a pH-dependent structural transition from native state to partially folded (PF) conformation. In the pH range 5–3, T7L PF states display differential ANS binding characteristics.Methods
CD, fluorescence, NMR spectroscopy and lysis assays were used to investigate the structure-stability- dynamics relationships of T7L PF conformations.Results
Structural studies indicated a partial loss of secondary/tertiary structures compared to its native state. The loss in the tertiary structure and the hydrophobic core opening increases upon decrease of pH from 5 to 3. Thermal denaturation experiments delineated that the pH?5 conformation is thermally irreversible in contrast to pH?3, depicting that hydrophobic core opening is essential for thermal reversibility. Further, urea dependent unfolding features of PF state at pH?5 and 4 evidenced for a collapsed conformation at intermediate urea concentrations. Residue level studies revealed that α1-helix and β3-β4 segment of T7L are the major contributors for such a structural collapse and inherent dynamics.Conclusions
The results suggested that the low pH PF states of T7L are heterogeneous and exhibits differential structural, unfolding, thermal reversibility, and dynamic features.General significance
Unraveling the structure-stability characteristics of different endolysin conformations is essential for designing novel chimeric and engineered phage endolysins as broadband antimicrobial agents over a varied pH range. 相似文献6.
Seong-Cheol Park Il Ryong Kim Jin-Young Kim Yongjae Lee Eun-Ji Kim Ji Hyun Jung Young Jun Jung Mi-Kyeong Jang Jung Ro Lee 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(12):2545-2554
Background
It remains an open question whether plant phloem sap proteins are functionally involved in plant defense mechanisms.Methods
The antifungal effects of two profilin proteins from Arabidopsis thaliana, AtPFN1 and AtPFN2, were tested against 11 molds and 4 yeast fungal strains. Fluorescence profiling, biophysical, and biochemical analyses were employed to investigate their antifungal mechanism.Results
Recombinant AtPFN1 and AtPFN2 proteins, expressed in Escherichia coli, inhibited the cell growth of various pathogenic fungal strains at concentrations ranging from 10 to 160?μg/mL. The proteins showed significant intracellular accumulation and cell-binding affinity for fungal cells. Interestingly, the AtPFN proteins could penetrate the fungal cell wall and membrane and act as inhibitors of fungal growth via generation of cellular reactive oxygen species and mitochondrial superoxide. This triggered the AtPFN variant-induced cell apoptosis, resulting in morphological changes in the cells.Conclusion
PFNs may play a critical role as antifungal proteins in the Arabidopsis defense system against fungal pathogen attacks.General significance
The present study indicates that two profilin proteins, AtPFN1 and AtPFN2, can act as natural antimicrobial agents in the plant defense system. 相似文献7.
Felista L. Tansi Ronny Rüger Ansgar M. Kollmeier Markus Rabenhold Frank Steiniger Roland E. Kontermann Ulf K. Teichgraeber Alfred Fahr Ingrid Hilger 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(6):1389-1400
Background
Endoglin (CD105) is overexpressed on tumor cells and tumor vasculatures, making it a potential target for diagnostic imaging and therapy of different neoplasms. Therefore, studies on nanocarrier systems designed for endoglin-directed diagnostic and drug delivery purposes would expose the feasibility of targeting endoglin with therapeutics.Methods
Liposomes carrying high concentrations of a near-infrared fluorescent dye in the aqueous interior were prepared by the lipid film hydration and extrusion procedure, then conjugated to single chain antibody fragments either selective for murine endoglin (termed mEnd-IL) or directed towards human endoglin (termed hEnd-IL). A combination of Dynamic Light Scattering, electron microscopy, cell binding and uptake assays, confocal microscopy and in vivo fluorescence imaging of mice bearing xenografted human breast cancer and human fibrosarcoma models were implemented to elucidate the potentials of the liposomes.Results
The mEnd-IL and hEnd-IL were highly selective for the respective murine- and human endoglin expressing cells in vitro and in vivo. Hence, the hEnd-IL bound distinctly to the tumor cells and enabled suitable fluorescence imaging of the tumors, whereas the mEnd-IL bound the tumor vasculature, but also to the liver, kidney and lung vasculature of mice.Conclusions
The work highlights key differences between targeting vascular (murine) and neoplastic (human) endoglin in animal studies, and suggests that the hEnd-IL can serve as a delivery system that targets human endoglin overexpressed in pathological conditions.General significance
The endoglin-targeting liposomes presented herewith represent strategic tools for the future implementation of endoglin-directed neoplastic and anti-angiogenic therapies. 相似文献8.
Ryota Iino Tatsuya Iida Akihiko Nakamura Ei-ichiro Saita Huijuan You Yasushi Sako 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(2):241-252
Background
Biological molecular machines support various activities and behaviors of cells, such as energy production, signal transduction, growth, differentiation, and migration.Scope of review
We provide an overview of single-molecule imaging methods involving both small and large probes used to monitor the dynamic motions of molecular machines in vitro (purified proteins) and in living cells, and single-molecule manipulation methods used to measure the forces, mechanical properties and responses of biomolecules. We also introduce several examples of single-molecule analysis, focusing primarily on motor proteins and signal transduction systems.Major conclusions
Single-molecule analysis is a powerful approach to unveil the operational mechanisms both of individual molecular machines and of systems consisting of many molecular machines.General significance
Quantitative, high-resolution single-molecule analyses of biomolecular systems at the various hierarchies of life will help to answer our fundamental question: “What is life?” This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato. 相似文献9.
Rafal Krela Elzbieta Poreba Martyna Weglewska Tomasz Skrzypczak Krzysztof Lesniewicz 《Biochimica et Biophysica Acta (BBA)/General Subjects》2019,1863(3):521-527
Background
During standard gene cloning, the recombinant protein appearing in bacteria as the result of expression leakage very often inhibits cell proliferation leading to blocking of the cloning procedure. Although different approaches can reduce transgene basal expression, the recombinant proteins, which even in trace amounts inhibit bacterial growth, can completely prevent the cloning process.Methods
Working to solve the problem of DNase II-like cDNA cloning, we developed a novel cloning approach. The method is based on separate cloning of the 5′ and 3′ fragments of target cDNA into a vector in such a way that the short Multiple Cloning Site insertion remaining between both fragments changes the reading frame and prevents translation of mRNA arising as a result of promoter leakage. Subsequently, to get the vector with full, uninterrupted Open Reading Frame, the Multiple Cloning Site insertion is removed by in vitro restriction/ligation reactions, utilizing the unique restriction site present in native cDNA.Results
Using this designed method, we cloned a coding sequence of AcDNase II that is extremely toxic for bacteria cells. Then, we demonstrated the usefulness of the construct prepared in this way for overexpression of AcDNase II in eukaryotic cells.Conclusions
The designed method allows cloning of toxic protein coding sequences that cannot be cloned by standard methods.General significance
Cloning of cDNAs encoding toxic proteins is still a troublesome problem that hinders the progress of numerous studies. The method described here is a convenient solution to cloning problems that are common in research on toxic proteins. 相似文献10.
Shreyasi Asthana Zaved Hazarika Parth Sarathi Nayak Jyoti Roy Anupam Nath Jha Bibekanand Mallick Suman Jha 《Biochimica et Biophysica Acta (BBA)/General Subjects》2019,1863(1):153-166
Background
Injection localized amyloidosis is one of the most prevalent disorders in type II diabetes mellitus (TIIDM) patients relying on insulin injections. Previous studies have reported that nanoparticles can play a role in the amyloidogenic process of proteins. Hence, the present study deals with the effect of zinc oxide nanoparticles (ZnONP) on the amyloidogenicity and cytotoxicity of insulin.Methods
ZnONP is synthesised and characterized using XRD, Zeta Sizer, UV-Visible spectroscope and TEM. The characterization is followed by ZnONP interaction with insulin, which is studied employing fluorescence spectroscopes, isothermal titration calorimetry and molecular dynamics simulations. The interaction leads insulin conformational rearrangement into amyloid-like fibril, which is studied using thioflavin T dye binding assay, circular dichroism spectroscopy and TEM, followed by cytotoxicity propensity using Alamar Blue dye reduction assay.Results
Insulin has very weak interaction with ZnONP interface. Insulin at studied concentration forms amorphous aggregates at physiological pH, whereas in presence of ZnONP interface amyloid-like fibrils are formed. While the amyloid-like fibrils are cytotoxic to MIN6 and THP-1 cell lines, insulin and ZnONP individual solutions and their fresh mixtures enhance the cells proliferation.Conclusions
The presence of ZnONP interface enhances insulin fibrillation at physiological pH by providing a favourable template for the nucleation and growth of insulin amyloids.General significance
The studied protein-nanoparticle system from protein conformational dynamics point of view throws caution over nanoparticle use in biological applications, especially in vivo applications, considering the amyloidosis a very slow but non-curable degenerative disease. 相似文献11.
Stefanie Nowak Antonella Di Pizio Anat Levit Masha Y. Niv Wolfgang Meyerhof Maik Behrens 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(10):2162-2173
Background
In humans, bitterness perception is mediated by ~25 bitter taste receptors present in the oral cavity. Among these receptors three, TAS2R10, TAS2R14 and TAS2R46, exhibit extraordinary wide agonist profiles and hence contribute disproportionally high to the perception of bitterness. Perhaps the most broadly tuned receptor is the TAS2R14, which may represent, because of its prominent expression in extraoral tissues, a receptor of particular importance for the physiological actions of bitter compounds beyond taste.Methods
To investigate how the architecture and composition of the TAS2R14 binding pocket enables specific interactions with a complex array of chemically diverse bitter agonists, we carried out homology modeling and ligand docking experiments, subjected the receptor to point-mutagenesis of binding site residues and performed functional calcium mobilization assays.Results
In total, 40 point-mutated receptor constructs were generated to investigate the contribution of 19 positions presumably located in the receptor's binding pocket to activation by 7 different TAS2R14 agonists. All investigated positions exhibited moderate to pronounced agonist selectivity.Conclusions
Since numerous modifications of the TAS2R14 binding pocket resulted in improved responses to individual agonists, we conclude that this bitter taste receptor might represent a suitable template for the engineering of the agonist profile of a chemoreceptive receptor.General significance
The detailed structure-function analysis of the highly promiscuous and widely expressed TAS2R14 suggests that this receptor must be considered as potentially frequent target for known and novel drugs including undesired off-effects. 相似文献12.
D. Bellavia L. Raimondi V. Costa A. De Luca V. Carina M. Maglio M. Fini R. Alessandro G. Giavaresi 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(9):1893-1901
Background
Exosomes are nanovesicles actively secreted by potentially all cell types, including tumour cells, with the primary role of extracellular systemic communication mediators, both at autocrine and paracrine levels, at short and long distances. Recently, different studies have used exosomes as a delivery system for a plethora of different molecules, such as drugs, microRNAs and proteins. This has been made possible thanks to the simplicity in exosomes engineering, their great stability and versatility for applications in oncology as well as in regenerative medicine.Scope of review
The aim of this review is to provide information on the state-of-the-art and possible applications of engineered exosomes, both for cargo and specific cell-targeting, in different pathologies related to the musculoskeletal system.Major conclusions
The use of exosomes as therapeutic agents is rapidly evolving, different studies explore drug delivery with exosomes using different molecules, showing an enormous potential in various research fields such as oncology and regenerative medicine.General significance
However, despite the significant progress made by the different studies carried out, currently, the use of exosomes is not a therapeutic reality for the considerable difficulties to overcome. 相似文献13.
Marilene Demasi Fernanda Marques da Cunha 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(12):2948-2954
Background
It has been almost three decades since the removal of oxidized proteins by the free 20S catalytic unit of the proteasome (20SPT) was proposed. Since then, experimental evidence suggesting a physiological role of proteolysis mediated by the free 20SPT has being gathered.Scope of review
Experimental data that favors the hypothesis of free 20SPT as playing a role in proteolysis are critically reviewed.Major conclusions
Protein degradation by the proteasome may proceed through multiple proteasome complexes with different requirements though the unequivocal role of the free 20SPT in cellular proteolysis towards native or oxidized proteins remains to be demonstrated.General significance
The biological significance of proteolysis mediated by the free 20SPT has been elusive since its discovery. The present review critically analyzes the available experimental data supporting the proteolytic role of the free or single capped 20SPT. 相似文献14.
Simin Feng Zhuqing Dai Anna B. Liu Jinbao Huang Nihal Narsipur Grace Guo Bo Kong Kenneth Reuhl Wenyun Lu Zisheng Luo Chung S. Yang 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2018,1863(10):1274-1284
Objective
To investigate and compare the effects of two common dietary phytosterols, stigmasterol and β-sitosterol, in altering lipid metabolism and attenuating nonalcoholic fatty liver disease (NAFLD).Methods
Stigmasterol and β-sitosterol were administered to mice at 0.4% in a high-fat western-style diet (HFWD) for 17?weeks.Results
Stigmasterol and β-sitosterol significantly ameliorated HFWD-induced fatty liver and metabolic abnormalities, including elevated levels of hepatic total lipids, triacylglycerols, cholesterol and liver histopathology. Both phytosterols decreased the levels of intestinal bile acids, accompanied by markedly increased fecal lipid levels. In addition, they altered the expression of genes involved in lipid metabolism. β-Sitosterol was less effective in affecting most of these parameters. Lipidomic analysis of liver and serum samples showed that stigmasterol prevented the HFWD-induced elevation of some di- and triacylglycerol species and lowering of some phospholipid species. Stigmasterol also decreased serum levels of ceramides.Conclusion
Stigmasterol and β-sitosterol, at a dose corresponding to that suggested for humans by the FDA for lowering cholesterol levels, are shown to alleviate HFWD-induced NAFLD. Stigmasterol was more effective than β-sitosterol, possibly because of its suppression of hepatic lipogenic gene expression and modulation of circulating ceramide levels. 相似文献15.
Irena Trbojević-Akmačić Frano Vučković Marija Vilaj Andrea Skelin Lennart C. Karssen Jasminka Krištić Julija Jurić Ana Momčilović Jelena Šimunović Massimo Mangino Manuela De Gregori Maurizio Marchesini Concetta Dagostino Jerko Štambuk Mislav Novokmet Richard Rauck Yurii S. Aulchenko Dragan Primorac Gordan Lauc 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(10):2124-2133
Background
Low back pain (LBP) is the symptom of a group of syndromes with heterogeneous underlying mechanisms and molecular pathologies, making treatment selection and patient prognosis very challenging. Moreover, symptoms and prognosis of LBP are influenced by age, gender, occupation, habits, and psychological factors. LBP may be characterized by an underlying inflammatory process. Previous studies indicated a connection between inflammatory response and total plasma N-glycosylation. We wanted to identify potential changes in total plasma N-glycosylation pattern connected with chronic low back pain (CLBP), which could give an insight into the pathogenic mechanisms of the disease.Methods
Plasma samples of 1128 CLBP patients and 760 healthy controls were collected in clinical centers in Italy, Belgium and Croatia and used for N-glycosylation profiling by hydrophilic interaction ultra-performance liquid chromatography (HILIC-UPLC) after N-glycans release, fluorescent labeling and clean-up. Observed N-glycosylation profiles have been compared with a cohort of 126 patients with acute inflammation that underwent abdominal surgery.Results
We have found a statistically significant increase in the relative amount of high-branched (tri-antennary and tetra-antennary) N-glycan structures on CLBP patients' plasma glycoproteins compared to healthy controls. Furthermore, relative amounts of disialylated and trisialylated glycan structures were increased, while high-mannose and glycans containing bisecting N-acetylglucosamine decreased in CLBP.Conclusions
Observed changes in CLBP on the plasma N-glycome level are consistent with N-glycosylation changes usually seen in chronic inflammation.General significance
To our knowledge, this is a first large clinical study on CLBP patients and plasma N-glycome providing a new glycomics perspective on potential disease pathology. 相似文献16.
Andrea Pica Serena Leone Rocco Di Girolamo Federica Donnarumma Alessandro Emendato Michele Fortunato Rega Antonello Merlino Delia Picone 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(4):808-815
Background
MNEI and its variant Y65R-MNEI are sweet proteins with potential applications as sweeteners in food industry. Also, they are often used as model systems for folding and aggregation studies.Methods
X-ray crystallography was used to structurally characterize Y65R-MNEI at five different pHs, while circular dichroism and fluorescence spectroscopy were used to study their thermal and chemical stability. ThT assay and AFM were used for studying the kinetics of aggregation and morphology of the aggregates.Results
Crystal structures of Y65R-MNEI revealed the existence of a dimer in the asymmetric unit, which, depending on the pH, assumes either an open or a closed conformation. The pH dramatically affects kinetics of formation and morphology of the aggregates: both MNEI and Y65R-MNEI form fibrils at acidic pH while amorphous aggregates are observed at neutral pH.Conclusions
The mutation Y65R induces structural modifications at the C-terminal region of the protein, which account for the decreased stability of the mutant when compared to MNEI. Furthermore, the pH-dependent conformation of the Y65R-MNEI dimer may explain the different type of aggregates formed as a function of pH.General significance
The investigation of the structural bases of aggregation gets us closer to the possibility of controlling such process, either by tuning the physicochemical environmental parameters or by site directed mutagenesis. This knowledge is helpful to expand the range of stability of proteins with potential industrial applications, such as MNEI and its mutant Y65R-MNEI, which should ideally preserve their structure and soluble state through a wide array of conditions. 相似文献17.
W.F. Theeuwes H.R. Gosker R.C.J. Langen N.A.M. Pansters A.M.W.J. Schols A.H.V. Remels 《生物化学与生物物理学报:疾病的分子基础》2018,1864(9):2913-2926
Background
Mitochondrial biogenesis is crucial for myogenic differentiation and regeneration of skeletal muscle tissue and is tightly controlled by the peroxisome proliferator-activated receptor-γ co-activator 1 (PGC-1) signaling network. In the present study, we hypothesized that inactivation of glycogen synthase kinase (GSK)-3β, previously suggested to interfere with PGC-1 in non-muscle cells, potentiates PGC-1 signaling and the development of mitochondrial biogenesis during myogenesis, ultimately resulting in an enhanced myotube oxidative capacity.Methods
GSK-3β was inactivated genetically or pharmacologically during myogenic differentiation of C2C12 muscle cells. In addition, m. gastrocnemius tissue was collected from wild-type and muscle-specific GSK-3β knock-out (KO) mice at different time-points during the reloading/regeneration phase following a 14-day hind-limb suspension period. Subsequently, expression levels of constituents of the PGC-1 signaling network as well as key parameters of mitochondrial oxidative metabolism were investigated.Results
In vitro, both knock-down as well as pharmacological inhibition of GSK-3β not only increased expression levels of important constituents of the PGC-1 signaling network, but also potentiated myogenic differentiation-associated increases in mitochondrial respiration, mitochondrial DNA copy number, oxidative phosphorylation (OXPHOS) protein abundance and the activity of key enzymes involved in the Krebs cycle and fatty acid β-oxidation. In addition, GSK-3β KO animals showed augmented reloading-induced increases in skeletal muscle gene expression of constituents of the PGC-1 signaling network as well as sub-units of OXPHOS complexes compared to wild-type animals.Conclusion
Inactivation of GSK-3β stimulates activation of PGC-1 signaling and mitochondrial biogenesis during myogenic differentiation and reloading of the skeletal musculature. 相似文献18.
Viacheslav V. Senichkin Gelina S. Kopeina Eugeniia A. Prokhorova Alexey V. Zamaraev Inna N. Lavrik Boris Zhivotovsky 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(3):557-566
Background
The development of approaches that increase therapeutic effects of anti-cancer drugs is one of the most important tasks of oncology. Caloric restriction in vivo or serum deprivation (SD) in vitro has been shown to be an effective tool for sensitizing cancer cells to chemotherapeutic drugs. However, the detailed mechanisms underlying the enhancement of apoptosis in cancer cells by SD remain to be elucidated.Methods
Flow cytometry, caspase activity assay and western blotting were used for cell death rate evaluation. Western blotting, gel-filtration, siRNA approach and qRT-PCR were used to elucidate the mechanism underlying cell death potentiation upon SD.Results
We demonstrated that SD sensitizes cancer cells to treatment with chemotherapeutic agent cisplatin. This effect is independent on activation of caspases-2 and -8, apical caspases triggering apoptosis in response to genotoxic stress. SD potentiates cell death via downregulation of the anti-apoptotic protein Mcl-1. In fact, SD reduces the Mcl-1 mRNA level, which consequently decreases the Mcl-1 protein level and renders cells more susceptible to apoptosis induction via the formation of apoptosome.Conclusions
Mcl-1 protein is an important regulator of sensitivity of cancer cells to apoptotic stimuli upon SD.General significance
This study identifies Mcl-1 as a new target for the sensitization of human cancer cells to cell death by SD, which is of great significance for the development of efficient anti-cancer therapies. 相似文献19.
Direct visualization of nucleolar G-quadruplexes in live cells by using a fluorescent light-up probe
Suge Zhang Hongxia Sun Hongbo Chen Qian Li Aijiao Guan Lixia Wang Yunhua Shi Shujuan Xu Meirong Liu Yalin Tang 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(5):1101-1106
Background
Direct detection of G-quadruplexes in human cells has become an important issue due to the vital role of G-quadruplex related to biological functions. Despite several probes have been developed for detection of the G-quadruplexes in cytoplasm or whole cells, the probe being used to monitor the nucleolar G-quadruplexes is still lacking.Methods
Formation of the nucleolar G-quadruplex structures was confirmed by using circular dichroism (CD) spectroscopy. The binding affinity and selectivity of Thioflavin T (ThT) towards various DNA/RNA motifs in solution and gel system were measured by using fluorescence spectroscopy and polyacrylamide gel electrophoresis (PAGE), respectively. G-quadruplex imaging in live cells was directly captured by using confocal laser scanning microscopy (CLSM).Results
Formation of the rDNA and rRNA G-quadruplex structures is demonstrated in vitro. ThT is found to show much higher affinity and selectivity towards these G-quadruplex structures versus other nucleic acid motifs either in solution or in gel system. The nucleolar G-quadruplexes in living cells are visualized by using ThT as a fluorescent probe. G-quadruplex-ligand treatments in live cells lead to sharp decrease of ThT signal.Conclusions
The natural existence of the G-quadruplexes structure in the nucleoli of living cells is directly visualized by using ThT as an indicator.General significance
The research provides substantive evidence for formation of the rRNA G-quadruplex structures, and also offers an effective probe for direct visualization of the nucleolar G-quadruplexes in living cells. 相似文献20.
Sheng-Wei Chang Jack Wellmerling Xiaoli Zhang Rachael E. Rayner Wissam Osman Sara Mertz Amal O. Amer Mark E. Peeples Prosper N. Boyaka Estelle Cormet-Boyaka 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(9):1988-1994