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1.
Eur J Pediatr ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767693

RESUMO

Coronavirus disease-19 (COVID-19) caused hospitalizations, severe disease, and deaths in any age, including in the youngest children. The aim of this multicenter national study is to characterize the clinical and the prognostic role of lung ultrasound (LU) in children with COVID-19. We enrolled children between 1 month and 18 years of age with severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection who underwent a LU within 6 h from the first medical evaluation. A total of 213 children were enrolled, 51.6% were male, median age was 2 years and 5 months (interquartile range (IQR) 4 months -11 years and 4 months). One hundred and forty-eight (69.4%) children were admitted in hospital, 9 (6.1%) in pediatric intensive care unit. We found an inverse correlation between the lung ultrasound score (LUS) and the oxygen saturation at the first clinical evaluation (r = -0.16; p = 0.019). Moreover, LUS was significantly higher in patients requiring oxygen supplementation (8 (IQR 3-19) vs 2 (IQR 0-4); p = 0.001). Among LU pathological findings, irregular pleural lines, subpleural consolidations, and pleural effusions were significantly more frequent in patients needing oxygen supplementation (p = 0.007, p = 0.006, and p = 0.001, respectively).  Conclusion: This multicenter study showed that LU in children with COVID-19 can highlight pleural line irregularities, vertical artifacts, and subpleural consolidation. Notably, children with higher LUS have a higher risk of hospitalization and need for oxygen supplementation, supporting LU as a valid and safe point-of-care first level tool for the clinical evaluation of children with COVID-19. What is Known: • Few children infected with SARS-CoV-2 develop a severe disease and need oxygen therapy. • Lung ultrasound can easily detect low respiratory tract infection during SARS-CoV-2. What is New: • Children with higher lung ultrasound score have a higher risk of need for oxygen supplementation. • Irregular pleural line, sub-pleural consolidations and pleural effusions were significantly more frequent in patients needing oxygen supplementation.

2.
J Clin Med ; 13(2)2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38256623

RESUMO

Celiac disease (CD) is frequently associated with other autoimmune disorders. Different studies have explored the association between CD and single autoimmune endocrine disease (AED), especially autoimmune thyroiditis (AIT) and type-1 diabetes mellitus (T1DM). Data about CD as a component of autoimmune polyendocrine syndrome (APS) are scant. We analyzed a large dataset including prospectively collected data from 920 consecutive adult CD patients diagnosed in a third-level Italian institution in the 2013-2023 period, The prevalence of isolated autoimmune endocrine diseases and APS were collected. A total of 262 (28.5%) CD patients had at least one associated AED, with AIT (n = 223, 24.2%) and T1DM (n = 27, 2.9%) being the most frequent conditions. In most cases (n = 173, 66%), AEDs were diagnosed after CD. Thirteen patients (1.4%) had at least two of the requested three endocrinopathies, satisfying the diagnosis of type 2 APS. APS-2 is a rare but not exceptional occurrence among Italian CD patients, underscoring the intricate and multifaceted nature of autoimmune disorders. Periodic evaluations of thyroid function and glycaemia should be recommended after the diagnosis of CD together with testing for autoantibodies that may be helpful in assessing disease risk before disease onset. Likewise, implementation of a systematic screening for CD amongst T1DM and other autoimmune endocrine diseases are paramount.

3.
World J Gastroenterol ; 29(33): 4962-4974, 2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37731994

RESUMO

Splanchnic vein thrombosis (SVT) is a manifestation of venous thromboembolism in an unusual site. Portal, mesenteric, and splenic veins are the most common vessels involved in SVT which occurs mainly in patients with liver cirrhosis, although non-cirrhotic patients could be affected as well. Thrombosis of hepatic veins, also known as Budd-Chiari syndrome, is another manifestation of SVT. Prompt diagnosis and intervention are mandatory in order to increase the recalization rate and reduce the risk of thrombus progression and hypertensive complications. Traditional anticoagulation with heparin and vitamin-K antagonists is the treatment of choice in these cases. However, recent studies have shown promising results on the efficacy and safety of direct oral anticoagulants (DOACs) in this setting. Available results are mainly based on retrospective studies with small sample size, but first clinical trials have been published in the last years. This manuscript aims to provide an updated overview of the current evidence regarding the role of DOACs for SVT in both cirrhotic and non-cirrhotic patients.


Assuntos
Síndrome de Budd-Chiari , Tromboembolia Venosa , Humanos , Estudos Retrospectivos , Anticoagulantes/efeitos adversos , Heparina
5.
Molecules ; 27(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35335307

RESUMO

Hybrid tannic acid-silica-based porous nanoparticles, TA-SiO2 NPs, have been synthesized under mild conditions in the presence of green and renewable tannic acid biopolymer, a glycoside polymer of gallic acid present in a large part of plants. Tannic acid (TA) was exploited as both a structuring directing agent and green chelating site for heavy metal ions recovery from aqueous solutions. Particles morphologies and porosity were easily tuned by varying the TA initial amount. The sample produced with the largest TA amount showed a specific surface area an order of magnitude larger than silica nanoparticles. The adsorption performance was investigated by using TA-SiO2 NPs as adsorbents for copper (II) ions from an aqueous solution. The effects of the initial Cu2+ ions concentration and the pH values on the adsorption capability were also investigated. The resulting TA-SiO2 NPs exhibited a different adsorption behaviour towards Cu2+, which was demonstrated through different tests. The largest adsorption (i.e., ~50 wt% of the initial Cu2+ amount) was obtained with the more porous nanoplatforms bearing a higher final TA content. The TA-nanoplatforms, stable in pH value around neutral conditions, can be easily produced and their use would well comply with a green strategy to reduce wastewater pollution.


Assuntos
Metais Pesados , Nanopartículas , Adsorção , Nanopartículas/química , Dióxido de Silício/química , Taninos/química
6.
Int J Mol Sci ; 23(5)2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35269725

RESUMO

Generation of the 3' overhang is a critical step during homologous recombination (HR) and replication fork rescue processes. This event is usually performed by a series of DNA nucleases and/or helicases. The nuclease NurA and the ATPase HerA, together with the highly conserved MRE11/RAD50 proteins, play an important role in generating 3' single-stranded DNA during archaeal HR. Little is known, however, about HerA-NurA function and activation of this fundamental and complicated DNA repair process. Herein, we analyze the functional relationship among NurA, HerA and the single-strand binding protein SSB from Saccharolubus solfataricus. We demonstrate that SSB clearly inhibits NurA endonuclease activity and its exonuclease activities also when in combination with HerA. Moreover, we show that SSB binding to DNA is greatly stimulated by the presence of either NurA or NurA/HerA. In addition, if on the one hand NurA binding is not influenced, on the other hand, HerA binding is reduced when SSB is present in the reaction. In accordance with what has been observed, we have shown that HerA helicase activity is not stimulated by SSB. These data suggest that, in archaea, the DNA end resection process is governed by the strictly combined action of NurA, HerA and SSB.


Assuntos
Proteínas Arqueais , Sulfolobus solfataricus , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , DNA/metabolismo , DNA Helicases/metabolismo , Reparo do DNA , DNA de Cadeia Simples/metabolismo , Sulfolobus solfataricus/metabolismo
7.
J Org Chem ; 86(18): 13001-13010, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34469156

RESUMO

The synthesis of calix[4]- and -[6]arene derivatives P6(H)22+·(Cl-)2, V4(H)24+·(Cl-)2·(I-)2, and V6(H)24+·(Cl-)2·(I-)2 bearing N-linked pyridinium (P) and viologen (V) units at the upper rim is described here. A rare example of an anionic conformational template is reported for p-pyridiniumcalix[6]arene P6(H)22+, which adopts a 1,3,5-alternate conformation in the presence of chloride anions. Derivatives P6(H)22+·(Cl-)2, V6(H)24+·(Cl-)2·(I-)2, and V4(H)24+·(Cl-)2·(I-)2 show a negative solvatochromism, while their UV-vis acid-base titration evidenced that upon addition of a base, new bands appear at 487, 583, and 686 nm, respectively, due to the formation of betainic monodeprotonated species P6(H)1+, V6(H)13+, and V4(H)13+. These new bands were attributable to the intramolecular charge-transfer (CT) transition from the phenoxide to the pyridinium or viologen moiety and were responsive to the presence of cations. In fact, the band at 487 nm of P6(H)1+ was quenched in the presence of a hard Li+ cation, and the color of its acetonitrile solution was changed from pink to colorless upon addition of LiI. Consequently, this derivative can be considered as a useful host for the recognition and sensing of lithium cations.


Assuntos
Calixarenos , Viologênios , Animais , Cátions , Cloretos , Cloro
10.
Nanomaterials (Basel) ; 11(1)2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33401556

RESUMO

An analytical method is presented in this work for the linear vibrations and buckling of nano-plates in a hygro-thermal environment. Nonlinear von Kármán terms are included in the plate kinematics in order to consider the instability phenomena. Strain gradient nonlocal theory is considered for its simplicity and applicability with respect to other nonlocal formulations which require more parameters in their analysis. Present nano-plates have a coupled magneto-electro-elastic constitutive equation in a hygro-thermal environment. Nano-scale effects on the vibrations and buckling behavior of magneto-electro-elastic plates is presented and hygro-thermal load outcomes are considered as well. In addition, critical temperatures for vibrations and buckling problems are analyzed and given for several nano-plate configurations.

11.
Cell Calcium ; 93: 102309, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33181424

RESUMO

The oxysterol-binding protein-related proteins (ORPs) have emerged as orchestrators of phosphatidylinositol-4,5-bisphosphate (PIP2) and cholesterol trafficking to the plasma membrane (PM). In this scenario, recent studies raised the prospect of ORPs cooperative behavior in sustaining leukemia stem cells (LSCs) survival by remotely enhancing ER-mitochondria Ca2+ communication. At the apex of the signaling cascade, the aberrantly upregulated LSC-ORP4L fosters PM-PIP2 extraction & cleavage, endoplasmic reticulum (ER)-Ca2+ release and mitochondrial energetics. The theoretical ember of draining fuel from the chemoresistant LSCs by restraining endoplasmic reticulum (ER)-mitochondria Ca2+ fluxes in a lipid-contingent fashion ensues. In light of relevant literature, this review briefly and critically discusses some key molecular ins & outs underlying such therapeutic opportunity in acute myeloid leukemia (AML).


Assuntos
Cálcio/metabolismo , Leucemia/metabolismo , Leucemia/patologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fosfatidilinositol 4,5-Difosfato/metabolismo , Animais , Colesterol/metabolismo , Humanos , Transdução de Sinais
12.
FEBS Lett ; 594(18): 3067-3075, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32620030

RESUMO

6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase isoform 3 (PFKFB3) is a key enzyme of the glycolytic pathway, and it plays an essential role in angiogenesis. 3-(3-Pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO) is frequently used as a glycolysis inhibitor and is thought to inhibit PFKFB3. However, this latter effect of 3PO has never been investigated in detail and was the aim of the present study. To demonstrate binding of 3PO to PFKFB3, we used isothermal titration calorimetry. However, 3PO did not bind to PFKFB3, even up to 750 µm, in contrast to 3 µm of AZ67, which is a potent and specific PFKFB3 inhibitor. Instead, 3PO accumulated lactic acid inside the cells, leading to a decrease in the intracellular pH and an inhibition of enzymatic reactions of the glycolytic pathway.


Assuntos
Glicólise/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Fosfofrutoquinase-2/metabolismo , Piridinas/farmacologia , Humanos , Ligação Proteica
13.
Artigo em Inglês | MEDLINE | ID: mdl-31501195

RESUMO

The pro- and antiapoptotic proteins belonging to the B-cell lymphoma-2 (Bcl-2) family exert a critical control over cell-death processes by enabling or counteracting mitochondrial outer membrane permeabilization. Beyond this mitochondrial function, several Bcl-2 family members have emerged as critical modulators of intracellular Ca2+ homeostasis and dynamics, showing proapoptotic and antiapoptotic functions. Bcl-2 family proteins specifically target several intracellular Ca2+-transport systems, including organellar Ca2+ channels: inositol 1,4,5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs), Ca2+-release channels mediating Ca2+ flux from the endoplasmic reticulum, as well as voltage-dependent anion channels (VDACs), which mediate Ca2+ flux across the mitochondrial outer membrane into the mitochondria. Although the formation of protein complexes between Bcl-2 proteins and these channels has been extensively studied, a major advance during recent years has been elucidating the complex interaction of Bcl-2 proteins with IP3Rs. Distinct interaction sites for different Bcl-2 family members were identified in the primary structure of IP3Rs. The unique molecular profiles of these Bcl-2 proteins may account for their distinct functional outcomes when bound to IP3Rs. Furthermore, Bcl-2 inhibitors used in cancer therapy may affect IP3R function as part of their proapoptotic effect and/or as an adverse effect in healthy cells.


Assuntos
Cálcio/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Animais , Apoptose , Retículo Endoplasmático/metabolismo , Fibroblastos/metabolismo , Homeostase , Humanos , Camundongos , Mitocôndrias/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Domínios Proteicos , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Proteína bcl-X/metabolismo
14.
Drug Discov Today ; 24(5): 1092-1103, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30910738

RESUMO

Intracellular Ca2+-flux systems located at the ER-mitochondrial axis govern mitochondrial Ca2+ balance and cell fate. Multiple yet incurable pathologies are characterized by insufficient or excessive Ca2+ fluxes toward the mitochondria, in turn leading to aberrant cell life or death dynamics. The discovery and ongoing molecular characterization of the main interorganellar Ca2+ gateways have resulted in a novel class of peptide tools able to regulate relevant protein-protein interactions (PPIs) underlying this signaling scenario. Here, we review peptides, molecularly derived from Ca2+-flux systems or their accessory proteins. We discuss how they alter Ca2+-signaling protein complexes and modulate cell survival in light of their forthcoming therapeutic applications.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Peptídeos/farmacologia , Animais , Retículo Endoplasmático/metabolismo , Humanos , Mitocôndrias/metabolismo , Peptídeos/uso terapêutico
15.
Int J Biol Macromol ; 122: 1224-1234, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30219517

RESUMO

An intracellular ß-xylosidase (AbXyl), from the thermoalkaline Anoxybacillus sp. 3M, was purified and characterized. The homodimeric enzyme (140 kDa) was optimally active at 65 °C and pH 5.5, exhibited half life of 10 h at 60 °C, 78 and 88% residual activity after 24 h, at pH 4.5 and 8.0, respectively. Fe2+, Cu2+, Al3+, Ag+ and Hg2+ inhibited the enzyme; the activity was moderately stimulated by SDS and not influenced by ß-mercaptoethanol. In the presence of p-nitrophenyl-ß-d-xylopyranoside, AbXyl exhibited Km of 0.19 mM, Kcat of 453.29 s-1, Kcat Km-1 of 2322 s-1 mM and was moderately influenced by xylose (Ki 21.25 mM). The enzyme hydrolyzed xylo-oligomers into xylose and catalyzed transxylosilation reactions also in presence of alcohols as acceptors, producing xylo-oligosaccharides and alkyl-xylosides. Finally AbXyl was applied towards a statistically optimized process of brewery's spent grain bioconversion, highlighting the important role of this biocatalyst in reaching high yields of fermentable sugars.


Assuntos
Agricultura , Anoxybacillus/enzimologia , Carboidratos/química , Resíduos Industriais , Xilosidases/metabolismo , Anoxybacillus/citologia , Inibidores Enzimáticos/farmacologia , Concentração de Íons de Hidrogênio , Hidrólise , Espaço Intracelular/enzimologia , Especificidade por Substrato , Temperatura , Xilosidases/antagonistas & inibidores
16.
Oxid Med Cell Longev ; 2018: 2615372, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30140363

RESUMO

Sarcopenia is the age-related loss of skeletal muscle mass, strength, and function. It is associated with regenerative difficulties by satellite cells, adult muscle stem cells, and alteration of oxidative management, mainly the increase in superoxide anions (O2•-). We aimed to investigate the relation between regenerative deficit in elderly and increase in O2•- production along with mitochondrial alterations. Myoblasts and myotubes from skeletal muscle of young and elderly healthy subjects (27.8 ± 6 and 72.4 ± 6.5 years old) were measured: (1) superoxide dismutase activity and protein content, (2) mitochondrial O2•- production levels, (3) O2•- production variability, and (4) mitochondrial bioenergetic profile. Compared to young myoblasts, elderly myoblasts displayed decreased SOD2 protein expression, elevated mitochondrial O2•- baseline levels, and decreased oxidative phosphorylation and glycolysis. Additionally, elderly versus young myotubes showed elevated mitochondrial O2•- levels when stressed with N-acetyl cysteine or high glucose and higher glycolysis despite showing comparable oxidative phosphorylation levels. Altogether, the elderly may have less metabolic plasticity due to the impaired mitochondrial function caused by O2•-. However, the increased energy demand related to the differentiation process appears to activate compensatory mechanisms for the partial mitochondrial dysfunction.


Assuntos
Biópsia/métodos , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Mioblastos/metabolismo , Superóxidos/metabolismo , Adulto , Idoso , Diferenciação Celular , Células Cultivadas , Feminino , Humanos , Masculino , Mioblastos/patologia
17.
Biochim Biophys Acta Mol Cell Res ; 1865(11 Pt B): 1707-1717, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29906486

RESUMO

Ca2+ signaling governs a diverse range of cellular processes and, as such, is subject to tight regulation. A main component of the complex intracellular Ca2+-signaling network is the inositol 1,4,5-trisphosphate (IP3) receptor (IP3R), a tetrameric channel that mediates Ca2+ release from the endoplasmic reticulum (ER) in response to IP3. IP3R function is controlled by a myriad of factors, such as Ca2+, ATP, kinases and phosphatases and a plethora of accessory and regulatory proteins. Further complexity in IP3R-mediated Ca2+ signaling is the result of the existence of three main isoforms (IP3R1, IP3R2 and IP3R3) that display distinct functional characteristics and properties. Despite their abundant and overlapping expression profiles, IP3R1 is highly expressed in neurons, IP3R2 in cardiomyocytes and hepatocytes and IP3R3 in rapidly proliferating cells as e.g. epithelial cells. As a consequence, dysfunction and/or dysregulation of IP3R isoforms will have distinct pathophysiological outcomes, ranging from neurological disorders for IP3R1 to dysfunctional exocrine tissues and autoimmune diseases for IP3R2 and -3. Over the past years, several IP3R mutations have surfaced in the sequence analysis of patient-derived samples. Here, we aimed to provide an integrative overview of the clinically most relevant mutations for each IP3R isoform and the subsequent molecular mechanisms underlying the etiology of the disease.


Assuntos
Suscetibilidade a Doenças , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Mutação , Animais , Cálcio/metabolismo , Sinalização do Cálcio , Regulação da Expressão Gênica , Humanos , Receptores de Inositol 1,4,5-Trifosfato/química , Isoformas de Proteínas
18.
FEBS J ; 285(1): 127-145, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29131545

RESUMO

B-cell lymphoma 2 (Bcl-2) protein is the archetype apoptosis suppressor protein. The N-terminal Bcl-2-homology 4 (BH4) domain of Bcl-2 is required for the antiapoptotic function of this protein at the mitochondria and endoplasmic reticulum (ER). The involvement of the BH4 domain in Bcl-2's antiapoptotic functions has been proposed based on Gly-based substitutions of the Ile14/Val15 amino acids, two hydrophobic residues located in the center of Bcl-2's BH4 domain. Following this strategy, we recently showed that a BH4-domain-derived peptide in which Ile14 and Val15 have been replaced by Gly residues, was unable to dampen proapoptotic Ca2+ -release events from the ER. Here, we investigated the impact of these mutations on the overall structure, stability, and function of full-length Bcl-2 as a regulator of Ca2+ signaling and cell death. Our results indicate that full-length Bcl-2 Ile14Gly/Val15Gly, in contrast to wild-type Bcl-2, (a) displayed severely reduced structural stability and a shortened protein half-life; (b) failed to interact with Bcl-2-associated X protein (BAX), to inhibit the inositol 1,4,5-trisphosphate receptor (IP3 R) and to protect against Ca2+ -mediated apoptosis. We conclude that the hydrophobic face of Bcl-2's BH4 domain (Ile14, Val15) is an important structural regulatory element by affecting protein stability and turnover, thereby likely reducing Bcl-2's ability to modulate the function of its targets, like IP3 R and BAX. Therefore, Bcl-2 structure/function studies require pre-emptive and reliable determination of protein stability upon introduction of point mutations at the level of the BH4 domain.


Assuntos
Isoleucina/genética , Mutação Puntual , Proteínas Proto-Oncogênicas c-bcl-2/genética , Valina/genética , Animais , Apoptose/genética , Células COS , Cálcio/metabolismo , Linhagem Celular Tumoral , Chlorocebus aethiops , Humanos , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Isoleucina/química , Isoleucina/metabolismo , Camundongos , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Estabilidade Proteica , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Valina/química , Valina/metabolismo
19.
PLoS One ; 12(10): e0185791, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28973046

RESUMO

Protein imaging, allowing a wide variety of biological studies both in vitro and in vivo, is of great importance in modern biology. Protein and peptide tags fused to proteins of interest provide the opportunity to elucidate protein location and functions, detect protein-protein interactions, and measure protein activity and kinetics in living cells. Whereas several tags are suitable for protein imaging in mesophilic organisms, the application of this approach to microorganisms living at high temperature has lagged behind. Archaea provide an excellent and unique model for understanding basic cell biology mechanisms. Here, we present the development of a toolkit for protein imaging in the hyperthermophilic archaeon Sulfolobus islandicus. The system relies on a thermostable protein tag (H5) constructed by engineering the alkylguanine-DNA-alkyl-transferase protein of Sulfolobus solfataricus, which can be covalently labeled using a wide range of small molecules. As a suitable host, we constructed, by CRISPR-based genome-editing technology, a S. islandicus mutant strain deleted for the alkylguanine-DNA-alkyl-transferase gene (Δogt). Introduction of a plasmid-borne H5 gene in this strain led to production of a functional H5 protein, which was successfully labeled with appropriate fluorescent molecules and visualized in cell extracts as well as in Δogt live cells. H5 was fused to reverse gyrase, a peculiar thermophile-specific DNA topoisomerase endowed with positive supercoiling activity, and allowed visualization of the enzyme in living cells. To the best of our knowledge, this is the first report of in vivo imaging of any protein of a thermophilic archaeon, filling an important gap in available tools for cell biology studies in these organisms.


Assuntos
Archaea/metabolismo , Proteínas Arqueais/metabolismo , Sulfolobus solfataricus/metabolismo , Sulfolobus/metabolismo , DNA Topoisomerases Tipo I/metabolismo , Temperatura Alta
20.
Front Oncol ; 7: 75, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28516063

RESUMO

Mitochondria are important regulators of cell death and cell survival. Mitochondrial Ca2+ levels are critically involved in both of these processes. On the one hand, excessive mitochondrial Ca2+ leads to Ca2+-induced mitochondrial outer membrane permeabilization and thus apoptosis. On the other hand, mitochondria need Ca2+ in order to efficiently fuel the tricarboxylic acid cycle and maintain adequate mitochondrial bioenergetics. For obtaining this Ca2+, the mitochondria are largely dependent on close contact sites with the endoplasmic reticulum (ER), the so-called mitochondria-associated ER membranes. There, the inositol 1,4,5-trisphosphate receptors are responsible for the Ca2+ release from the ER. It comes as no surprise that this Ca2+ release from the ER and the subsequent Ca2+ uptake at the mitochondria are finely regulated. Cancer cells often modulate ER-Ca2+ transfer to the mitochondria in order to promote cell survival and to inhibit cell death. Important regulators of these Ca2+ signals and the onset of cancer are the B-cell lymphoma 2 (Bcl-2) family of proteins. An increasing number of reports highlight the ability of these Bcl-2-protein family members to finely regulate Ca2+ transfer from ER to mitochondria both in healthy cells and in cancer. In this review, we focus on recent insights into the dynamic regulation of ER-mitochondrial Ca2+ fluxes by Bcl-2-family members and how this impacts cell survival, cell death and mitochondrial energy production.

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