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1.
Khirurgiia (Mosk) ; (5): 25-30, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31169815

RESUMO

AIM: To justify the concept of systemic membrane-destabilizing distress syndrome in surgery via analysis of phospholipid bilayer of cell membranes of various organs in urgent surgical abdominal diseases. MATERIAL AND METHODS: Experimental research on dogs (n=90) included modeling of peritonitis, pancreatitis, intestinal obstruction, obstructive jaundice, and post-hemorrhagic anemia. Clinical and laboratory studies were performed in patients (n=119) with acute peritonitis, severe pancreatitis, intestinal obstruction, post-hemorrhagic anemia, acute cholecystitis, gastrointestinal bleeding, benign mechanical jaundice. Lipid profile in tissues and blood cells was determined by extraction, fractionation and densitometry. Moreover, we assessed intensity of lipid peroxidation and phospholipase activity, endogenous intoxication, functional state of organs and blood cells. RESULTS: It was revealed that all above-mentioned acute abdominal diseases are followed by significant changes of lipid bilayer and dysfunction of tissues in target organs, blood cells and other organs (liver, kidney, colon and small intestine, heart, lungs, spleen, brain). Changes of phospholipid bilayer are correlated with severity and course of the disease. These data were used to determine a new complex in surgery - systemic membrane-destabilizing distress syndrome. Its concept, pathogenesis, and diagnosis are presented. It was analyzed its role in development and progression of dysregulation pathology and thanatogenesis. Evidence of its importance in the pathogenesis of surgical aggression was obtained.


Assuntos
Anemia/fisiopatologia , Membrana Celular/fisiologia , Doenças do Sistema Digestório/fisiopatologia , Hemorragia/fisiopatologia , Icterícia Obstrutiva/fisiopatologia , Estresse Fisiológico/fisiologia , Anemia/complicações , Animais , Doenças do Sistema Digestório/complicações , Modelos Animais de Doenças , Cães , Hemorragia/complicações , Humanos , Icterícia Obstrutiva/complicações , Lipídeos de Membrana/fisiologia , Fosfolipídeos/fisiologia , Síndrome
2.
Nat Commun ; 10(1): 2752, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227693

RESUMO

Various studies have demonstrated that the two leaflets of cellular membranes interact, potentially through so-called interdigitation between the fatty acyl groups. While the molecular mechanism underlying interleaflet coupling remains to be fully understood, recent results suggest interactions between the very-long-chain sphingolipids in the outer leaflet, and phosphatidylserine PS18:0/18:1 in the inner leaflet, and an important role for cholesterol for these interactions. Here we review the evidence that cross-linking of sphingolipids may result in clustering of phosphatidylserine and transfer of signals to the cytosol. Although much remains to be uncovered, the molecular properties and abundance of PS 18:0/18:1 suggest a unique role for this lipid.


Assuntos
Membrana Celular/fisiologia , Bicamadas Lipídicas/metabolismo , Fosfatidilserinas/metabolismo , Esfingolipídeos/metabolismo , Animais , Linhagem Celular , Colesterol/metabolismo , Reagentes para Ligações Cruzadas/metabolismo , Citosol/fisiologia , Humanos
3.
Plant Sci ; 283: 385-395, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128709

RESUMO

High temperature is a major environmental factor affecting plant growth. Heat shock proteins (Hsps) are molecular chaperones that play important roles in improving plant thermotolerance during heat stress. Spinach (Spinacia oleracea) is very sensitive to high temperature; however, the specific function of Hsps in spinach is unclear. In this study, cytosolic heat shock 70 protein (SoHSC70), which was induced by heat stress, was cloned from spinach. Overexpressing SoHSC70 in spinach calli and Arabidopsis enhanced their thermotolerance. In contrast, spinach seedlings with silenced SoHSC70 by virus-induced gene silencing (VIGS) showed more sensitivity to heat stress. Further analysis revealed that overexpressing SoHSC70 altered relative electrical conductivity (REC), malondialdehyde (MDA) content, photosynthetic rate, reactive oxygen species (ROS) accumulation and the activities of antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) after the heat treatment. Taken together, our results suggest that overexpressing SoHSC70 positively affects heat tolerance by reducing membrane damage and ROS accumulation and improving activities of antioxidant enzymes.


Assuntos
Antioxidantes/metabolismo , Membrana Celular/metabolismo , Proteínas de Choque Térmico/fisiologia , Proteínas de Plantas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Spinacia oleracea/metabolismo , Termotolerância , Arabidopsis , Membrana Celular/fisiologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Malondialdeído/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Análise de Sequência de DNA , Spinacia oleracea/genética , Spinacia oleracea/fisiologia
4.
J BUON ; 24(1): 158-162, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30941965

RESUMO

PURPOSE: The present study explored the potential of microwaves on membrane fluidity changes in diethylnitrosamine (DEN) induced hepatocellular carcinoma (HCC), in vivo. METHODS: Rats were segregated into four groups: normal control, DEN-treated, microwave-treated, DEN+microwave-treated. Brush border membranes (BBM) were isolated from the rats and, using the membrane extrinsic fluorophore pyrene, we assessed the viscosities as well as fluidity parameters. RESULTS: DEN treatment resulted in a significant rise in lipid peroxidation (LPO). Reduced glutathione levels (GSH) and the activities of glutathione reductase (GR), glutathione transferase (GST), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were found to be significantly decreased following DEN treatment. On the other hand, microwave treatment in DEN-treated rats resulted in a significant decrease in the levels of lipid peroxidation but caused a significant rise in the levels of GSH as well in the activities of GR, GST, SOD, CAT and GPx. The results further demonstrated a marked decrease in membrane microviscosity following DEN treatment. On the other hand, a significant increase was observed in the excimer/monomer ratio and fluidity parameter of DEN-treated rats when compared to normal control rats. However, the alterations in membrane microviscosity and the fluidity parameters were significantly restored after microwave treatment. CONCLUSION: The study, therefore, concludes that microwave proved quite useful in the modulation of membrane stability parameters following DEN-induced hepatic cancer.


Assuntos
Membrana Celular/fisiologia , Dietilnitrosamina/toxicidade , Neoplasias Hepáticas/prevenção & controle , Fluidez de Membrana/fisiologia , Micro-Ondas/uso terapêutico , Alquilantes/toxicidade , Animais , Catalase/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/efeitos da radiação , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/metabolismo , Masculino , Fluidez de Membrana/efeitos dos fármacos , Fluidez de Membrana/efeitos da radiação , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo
5.
Math Biosci Eng ; 16(3): 1392-1413, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30947426

RESUMO

Cell polarity refers to spatial di erences in the shape and structure of cells, which leads to the generation of diverse cell types playing di erent roles in biological processes. Cell polarization usually involves the localization of some specific signaling molecules to a proper location of the cell membrane. Recent studies proposed that delayed negative feedback may be important for maintaining the robustness of cell polarization and the observed oscillating behavior of signaling cluster. However, the fundamental mechanisms for achieving cell polarization under negative feedback remain controversial. In this paper, we formulate the cell polarization system as a non-local reaction di usion equation with positive and delayed negative feedback loops. Through the Turing stability analysis, we identify the parameter conditions, including the range of the time delay constant, for achieving cell polarization without any inhomogeneous spatial cues. Also, our numerical results support that by controlling the length of the time delay in negative feedback and the magnitude of positive feedback, the oscillating behavior of signaling cluster can be observed in our simulations.


Assuntos
Membrana Celular/fisiologia , Polaridade Celular , Simulação por Computador , Saccharomyces cerevisiae/fisiologia , Transdução de Sinais , Retroalimentação Fisiológica , Modelos Lineares , Modelos Biológicos , Saccharomyces cerevisiae/genética
6.
Sheng Li Xue Bao ; 71(2): 196-204, 2019 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-31008479

RESUMO

Cell-to-cell connections provide conduits for signal exchanges, and play important functional roles in physiological and pathological processes of multicellular organisms. Membrane nanotubes are common long-distance connections between cells, not only transfer molecule signals and mitochondria, but also cooperate with gap junction and other cell-to-cell communications to transfer signals. During the last decade, there are many studies about membrane nanotubes, which focus on the similarities and differences between membrane nanotubes and other cell-to-cell communications, as well as their biological functions. In the present review, we summarized the latest findings about the structural diversity, the similarities and differences in signal transmission with other types of cell-to-cell communications, and physiological and pathological roles of membrane nanotubes.


Assuntos
Comunicação Celular , Membrana Celular/fisiologia , Junções Comunicantes/fisiologia , Nanotubos , Humanos , Mitocôndrias/fisiologia
7.
Nat Plants ; 5(2): 194-203, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30737512

RESUMO

During arbuscular mycorrhizal (AM) symbiosis, cells within the root cortex develop a matrix-filled apoplastic compartment in which differentiated AM fungal hyphae called arbuscules reside. Development of the compartment occurs rapidly, coincident with intracellular penetration and rapid branching of the fungal hypha, and it requires much of the plant cell's secretory machinery to generate the periarbuscular membrane that delimits the compartment. Despite recent advances, our understanding of the development of the periarbuscular membrane and the transfer of molecules across the symbiotic interface is limited. Here, using electron microscopy and tomography, we reveal that the periarbuscular matrix contains two types of membrane-bound compartments. We propose that one of these arises as a consequence of biogenesis of the periarbuscular membrane and may facilitate movement of molecules between symbiotic partners. Additionally, we show that the arbuscule contains massive arrays of membrane tubules located between the protoplast and the cell wall. We speculate that these tubules may provide the absorptive capacity needed for nutrient assimilation and possibly water absorption to enable rapid hyphal expansion.


Assuntos
Membrana Celular/fisiologia , Micorrizas/fisiologia , Células Vegetais/microbiologia , Raízes de Plantas/citologia , Raízes de Plantas/microbiologia , Membrana Celular/ultraestrutura , Tomografia com Microscopia Eletrônica , Medicago truncatula/genética , Medicago truncatula/microbiologia , Microscopia Eletrônica , Mutação , Micorrizas/ultraestrutura , Células Vegetais/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Simbiose
8.
Physiol Biochem Zool ; 92(2): 239-251, 2019 Mar/Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30741598

RESUMO

Although tissue fatty acid (FA) composition has been linked to whole-animal performance (e.g., aerobic endurance, metabolic rate, postexercise recovery) in a wide range of animal taxa, we do not adequately understand the pace of changes in FA composition and its implications for the ecology of animals. Therefore, we used a C4 to C3 diet shift experiment and compound-specific δ13C analysis to estimate the turnover rates of FAs in the polar and neutral fractions of flight muscle lipids (corresponding to membranes and lipid droplets) of exercised and sedentary zebra finches (Taeniopygia guttata). Turnover was fastest for linoleic acid (LA; 18:2n6) and palmitic acid (PA; 16:0), with 95% replacement times of 10.8-17.7 d in the polar fraction and 17.2-32.8 d in the neutral fraction, but was unexpectedly slow for the long-chain polyunsaturated FAs (LC-PUFAs) arachidonic acid (20:4n6) and docosahexaenoic acid (22:6n3) in the polar fraction, with 95% replacement in 64.9-136.5 d. Polar fraction LA and PA turnover was significantly faster in exercised birds (95% replacement in 8.5-13.3 d). Our results suggest that FA turnover in intramuscular lipid droplets is related to FA tissue concentrations and that turnover does not change in response to exercise. In contrast, we found that muscle membrane FA turnover is likely driven by a combination of selective LC-PUFA retention and consumption of shorter-chain FAs in energy metabolism. The unexpectedly fast turnover of membrane-associated FAs in muscle suggests that songbirds during migration could substantially remodel their membranes within a single migration stopover, and this may have substantial implications for how the FA composition of diet affects energy metabolism of birds during migration.


Assuntos
Tecido Adiposo/fisiologia , Composição Corporal/fisiologia , Ácidos Graxos/fisiologia , Tentilhões/fisiologia , Músculo Esquelético/fisiologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Membrana Celular/fisiologia , Dieta/veterinária , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Feminino , Masculino
9.
Appl Microbiol Biotechnol ; 103(5): 2121-2131, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30680434

RESUMO

Due to a constant attack by phage, bacteria in the environment have evolved diverse mechanisms to defend themselves. Several reviews on phage resistance mechanisms have been published elsewhere. Thanks to the advancement of molecular techniques, several new phage resistance mechanisms were recently identified. For the practical phage therapy, the emergence of phage-resistant bacteria could be an obstacle. However, unlike antibiotic, phages could evolve a mechanism to counter-adapt against phage-resistant bacteria. In this review, we summarized the most recent studies of the phage-bacteria arm race with the perspective of future applications of phages as antimicrobial agents.


Assuntos
Bactérias/virologia , Bacteriófagos/crescimento & desenvolvimento , Terapia por Fagos/métodos , Bactérias/genética , Proteínas de Bactérias/genética , Sistemas CRISPR-Cas/genética , Sistemas CRISPR-Cas/fisiologia , Membrana Celular/fisiologia , Interferência de RNA/fisiologia , Proteínas Repressoras/genética
10.
Biochim Biophys Acta Mol Cell Res ; 1866(4): 554-565, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30611767

RESUMO

Hearing loss is among the most prevalent sensory impairments in humans. Cochlear implantable devices represent the current therapies for hearing loss but have various shortcomings. ERM (ezrin- radixin -moesin) are a family of adaptor proteins that link plasma membrane with actin cytoskeleton, playing a crucial role in cell morphology and in the formation of membrane protrusions. Recently, bioactive sphingolipids have emerged as regulators of ERM proteins. Sphingosine 1-phosphate (S1P) is a pleiotropic sphingolipid which regulates fundamental cellular functions such as proliferation, survival, migration as well as processes such as development and inflammation mainly via ligation to its specific receptors S1PR (S1P1-5). Experimental findings demonstrate a key role for S1P signaling axis in the maintenance of auditory function. Preservation of cellular junctions is a fundamental function both for S1P and ERM proteins, crucial for the maintenance of cochlear integrity. In the present work, S1P was found to activate ERM in a S1P2-dependent manner in murine auditory epithelial progenitors US/VOT-E36. S1P-induced ERM activation potently contributed to actin cytoskeletal remodeling and to the appearance of ionic currents and membrane passive properties changes typical of more differentiated cells. Moreover, PKC and Akt activation was found to mediate S1P-induced ERM phosphorylation. The obtained findings contribute to demonstrate the role of S1P signaling pathway in inner ear biology and to disclose potential innovative therapeutical approaches in the field of hearing loss prevention and treatment.


Assuntos
Citoesqueleto de Actina/metabolismo , Cóclea/citologia , Proteínas do Citoesqueleto/metabolismo , Células Epiteliais/fisiologia , Lisofosfolipídeos/fisiologia , Esfingosina/análogos & derivados , Animais , Linhagem Celular , Membrana Celular/fisiologia , Fenômenos Eletrofisiológicos , Células Epiteliais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Proteínas dos Microfilamentos/metabolismo , Proteína Quinase C/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Lisoesfingolipídeo/fisiologia , Esfingosina/fisiologia , Células-Tronco/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
11.
J Agric Food Chem ; 67(7): 1918-1926, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30689371

RESUMO

Cold stress adversely affects cell viability and acidification, and new cryoprotective methods continue to be needed in cold-chain food industry. Given this, we investigated the cryoprotective effects and action mechanism of antifreeze peptides obtained from tilapia scales (TSAPP) on Streptococcus thermophilus during cold stress. Our results showed that the molecular weight of TSAPP ranged from 180 to 2000 Da and its thermal hysteresis activity was 0.29 °C. Growth of S. thermophilus was improved after treatment with TSAPP (1 mg/mL) under cold stress. This growth was notable when compared with the effects of other cryoprotectants. Furthermore, TSAPP improved the metabolic activity of S. thermophilus during cold stress. TSAPP likely offered its cellular protection by maintaining cell membrane fluidity through hydrogen bonding of the phospholipid bilayer. These results indicate that TSAPP has potential as a novel biological peptide material with cryoprotective activity for future use in probiotic or other processed food applications.


Assuntos
Escamas de Animais/química , Proteínas Anticongelantes/farmacologia , Resposta ao Choque Frio/efeitos dos fármacos , Crioprotetores/farmacologia , Streptococcus thermophilus/efeitos dos fármacos , Tilápia , Animais , Proteínas Anticongelantes/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Crioprotetores/química , Ligações de Hidrogênio , Fluidez de Membrana/efeitos dos fármacos , Peso Molecular , Streptococcus thermophilus/crescimento & desenvolvimento
12.
BMC Bioinformatics ; 20(1): 2, 2019 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-30606118

RESUMO

BACKGROUND: 3D segmentation is often a prerequisite for 3D object display and quantitative measurements. Yet existing voxel-based methods do not directly give information on the object surface or topology. As for spatially continuous approaches such as level-set, active contours and meshes, although providing surfaces and concise shape description, they are generally not suitable for multiple object segmentation and/or for objects with an irregular shape, which can hamper their adoption by bioimage analysts. RESULTS: We developed LimeSeg, a computationally efficient and spatially continuous 3D segmentation method. LimeSeg is easy-to-use and can process many and/or highly convoluted objects. Based on the concept of SURFace ELements ("Surfels"), LimeSeg resembles a highly coarse-grained simulation of a lipid membrane in which a set of particles, analogous to lipid molecules, are attracted to local image maxima. The particles are self-generating and self-destructing thus providing the ability for the membrane to evolve towards the contour of the objects of interest. The capabilities of LimeSeg: simultaneous segmentation of numerous non overlapping objects, segmentation of highly convoluted objects and robustness for big datasets are demonstrated on experimental use cases (epithelial cells, brain MRI and FIB-SEM dataset of cellular membrane system respectively). CONCLUSION: In conclusion, we implemented a new and efficient 3D surface reconstruction plugin adapted for various sources of images, which is deployed in the user-friendly and well-known ImageJ environment.


Assuntos
Membrana Celular/fisiologia , Imagem Tridimensional/métodos , Lipídeos/fisiologia , Humanos
13.
Microb Pathog ; 127: 368-379, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30557584

RESUMO

Microbial studies on Catfish revealed that Klebsiella is the most common pathogen causing prevalence of ulcers, fin erosion, and other lesions. During this study, a new strain of bacteria was isolated from Channa punctatus, and molecular identification by 16srRNA revealed the strain was Klebsiella PKBSG14 (Accession no KJ162158). The strain was also PCR positive for two virulent gene wcaG (Accession no LN606595) and rmpA (Accession no LN606594) responsible for inflammatory reactions and induction of innate immune response in the host cell. To study innate immune response induced by pathogenic infection the phagocytic interactive process between the spleen macrophages and KlebsiellaPKBSG14 was investigated using optical microscopy. FACS of splenic macrophages revealed that the phagocytic interaction leads to the process of macrophage cell cycle progression. A detailed study on the macrophage DNA content by performing DNA fragmentation and comet allowed us to study simultaneously host cell division as a function of phagocytosis and the findings unveiled the fact that Phagocytosis of KlebsiellaPKBSG14 aided in macrophage cell cycle progression but was less likely to complete mitosis. Here we also report the cytotoxic effect linked to the infection with KlebsiellaPKBSG14 by performing Cell viability assay, intracellular production of ROS, and mitochondrial transmembrane potential where it manifested itself in impaired cellular function. So, in summary, we simultaneously discovered a new strain of bacteria ie. Klebsiella PKBSG14 as well as deliberately attempted to study the immunomodulatory effect of isolated new stain on Channa punctatus by performing host-pathogen phagocytic interactive experiments, the cell cycle state of the host cell and pathogen-mediated cytotoxicity along with genotoxicity, and our results evidence a new immunomodulatory effect of KlebsiellaPKBSG14 infection on fish splenic macrophages.


Assuntos
Doenças dos Peixes/microbiologia , Doenças dos Peixes/patologia , Imunidade Inata , Infecções por Klebsiella/veterinária , Klebsiella/imunologia , Fatores de Virulência/imunologia , Animais , Peixes-Gato , Membrana Celular/fisiologia , Sobrevivência Celular , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Klebsiella/classificação , Klebsiella/genética , Klebsiella/isolamento & purificação , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/patologia , Macrófagos/imunologia , Potenciais da Membrana , Fagocitose , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Espécies Reativas de Oxigênio/metabolismo , Análise de Sequência de DNA , Baço/imunologia , Baço/microbiologia , Fatores de Virulência/genética
14.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1864(3): 312-325, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30553843

RESUMO

Cholesterol, an essential lipid component of cellular plasma membranes, regulates fluidity, mechanical integrity, raft structure and may specifically interact with membrane proteins. Numerous effects on ion channels by cholesterol, including changes in current amplitude, voltage dependence and gating kinetics, have been reported. We have previously described such changes in the voltage-gated potassium channel Kv1.3 of lymphocytes by cholesterol and its analog 7-dehydrocholesterol (7DHC). In voltage-gated channels membrane depolarization induces movement of the voltage sensor domains (VSD), which is transmitted by a coupling mechanism to the pore domain (PD) to open the channel. Here, we investigated whether cholesterol effects were mediated by the VSD to the pore or the PD was the direct target. Specificity was tested by comparing Kv1.3 and Kv10.1 channels having different VSD-PD coupling mechanisms. Current recordings were performed with two-electrode voltage-clamp fluorometry, where movement of the VSDs was monitored by attaching fluorophores to external cysteine residues introduced in the channel sequence. Loading the membrane with cholesterol or 7DHC using methyl-ß-cyclodextrin induced changes in the steady-state and kinetic parameters of the ionic currents while leaving fluorescence parameters mostly unaffected in both channels. Non-stationary noise analysis revealed that reduction of single channel conductance rather than that of open probability caused the observed current decrease. Furthermore, confocal laser scanning and stimulated emission depletion microscopy demonstrated significant changes in the distribution of these ion channels in response to sterol loading. Our results indicate that sterol-induced effects on ion channel gating directly target the pore and do not act via the VSD.


Assuntos
Membrana Celular/fisiologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Esteróis/metabolismo , Animais , Membrana Celular/metabolismo , Colesterol , Cisteína , Células HEK293 , Humanos , Membranas , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Proteínas de Xenopus/metabolismo , Xenopus laevis/metabolismo , beta-Ciclodextrinas
15.
Microbiol Res ; 218: 108-117, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30454652

RESUMO

All three domains of life have an ordered plasma membrane which is pivotal in the selective fitness of primitive life. Like cholesterol in eukaryotes, hopanoids are important in bacteria to modulate membrane order. Hopanoids are pentacyclic triterpenoid lipids biosynthesised in many eubacteria, few ferns and lichens. Hopanoid modulates outer membrane order and hopanoid deficiency results in the weakened structural integrity of the membrane which may in turn affect the other structures within or spanning the cell envelope and contributing to various membrane functions. Hence, to decipher the role of hopanoid, genome-wide transcriptome of wild-type and Δshc mutant of Rhodopseudomonas palustris TIE-1 was studied which indicated 299 genes were upregulated and 306 genes were downregulated in hopanoid deficient mutant, representing ∼11.5% of the genome. Thirty-eight genes involved in chemotaxis, response to stimuli and signal transduction were differentially regulated and impaired motility in hopanoid deficient mutant showed that hopanoid plays a crucial role in chemotaxis. The docking study demonstrated that diguanylate cyclase which catalyses the synthesis of secondary messenger exhibited the capability to interact with hopanoids and might be confederating in chemotaxis and signal transduction. Seventy-four genes involved in membrane transport were differentially expressed and cell assays also explicit that the multidrug transport is compromised in Δshc mutant. Membrane transport is reliant on hopanoids which may explain the basis for previous observations linking hopanoids to antibiotic resistance. Disturbing the membrane order by targeting lipid synthesis can be a possible novel approach in developing new antimicrobials and hopanoid biosynthesis could be a potential target.


Assuntos
Transporte Biológico/genética , Membrana Celular/fisiologia , Quimiotaxia/genética , Regulação Bacteriana da Expressão Gênica/genética , Proteínas de Membrana Transportadoras/genética , Rodopseudomonas/genética , Rodopseudomonas/metabolismo , Triterpenos/metabolismo , Proteínas de Escherichia coli/metabolismo , Deleção de Genes , Perfilação da Expressão Gênica , Proteínas de Membrana Transportadoras/metabolismo , Fósforo-Oxigênio Liases/metabolismo , Transdução de Sinais/genética
17.
J Vis Exp ; (141)2018 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-30582597

RESUMO

Standard spermiograms describing sperm quality are mostly based on the physiological and visual parameters, such as ejaculate volume and concentration, motility and progressive motility, and sperm morphology and viability. However, none of these assessments is good enough to predict the semen quality. Given that maintenance of sperm viability and fertilization potential depends on membrane integrity and intracellular functionality, evaluation of these parameters might enable a better prediction of sperm fertilization competence. Here, we describe three feasible methods to evaluate sperm quality using specific fluorescent probes combined with fluorescence microscopy or flow cytometry analyses. Analyses assessed plasma membrane integrity using 4',6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI), acrosomal membrane integrity using fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and mitochondrial membrane integrity using 5,5',6,6'-tetra-chloro-1,1',3,3'-tetraethylbenzimidazolyl carbocyanine iodide (JC-1). Combinations of these methods are also presented. For instance, use of annexin V combined with PI fluorochromes enables assessing apoptosis and calculating the proportion of apoptotic sperm (apoptotic index). We believe that these methodologies, which are based on examining spermatozoon membranes, are very useful for the evaluation of sperm quality.


Assuntos
Fluorometria/métodos , Motilidade Espermática/fisiologia , Espermatozoides/química , Espermatozoides/fisiologia , Animais , Bovinos , Membrana Celular/química , Membrana Celular/fisiologia , Citometria de Fluxo/métodos , Corantes Fluorescentes/análise , Masculino , Microscopia de Fluorescência/métodos , Propídio/análise , Análise do Sêmen/métodos
18.
Microsc Microanal ; 24(6): 713-728, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30588913

RESUMO

Venous thrombosis is associated with combined oral contraceptive (COC) use. We investigated the impact of two ethinyl estradiol (EE) and drospirenone (DRSP) containing COCs (3 mg DRSP/20 µg EE and 3 µg DRSP/30 µg EE) on the viscoelasticity of whole blood clots along with the biophysical and biochemical characteristics of erythrocytes. Thromboelastography (TEG) analysis showed a tendency toward a hypercoagulable state in the COCs groups that was more pronounced with higher EE concentrations. Light microscopy and scanning electron microscopy (SEM) showed rouleaux formation of erythrocytes and alterations to the erythrocyte shape for both COC groups, which was attributed to membrane damage. SEM analysis showed spontaneous activation of fibrin and platelets in the COC groups, along with interactions between erythrocytes and platelets and/or fibrin. Confocal microscopy confirmed compromised membrane integrity in the COC groups compared to controls. Global thrombosis test analysis showed increased platelet activation and low thrombolysis in both COC groups when compared to controls. In conclusion, DRSP/EE formulations impact erythrocytes' biophysical and biochemical properties to cause a shift in hemostasis to a prothrombotic state. Although these effects are mostly subclinical the long-term effects and risks involved with the use of these hormones should be considered carefully for each individual.


Assuntos
Androstenos/farmacologia , Anticoncepcionais Orais Combinados/farmacologia , Módulo de Elasticidade/efeitos dos fármacos , Agregação Eritrocítica/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Etinilestradiol/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Trombose Venosa/induzido quimicamente , Viscosidade/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Membrana Celular/fisiologia , Forma Celular/efeitos dos fármacos , Eritrócitos/química , Feminino , Humanos , Microscopia Eletrônica de Varredura , Tromboelastografia
19.
Reprod Domest Anim ; 53 Suppl 2: 37-45, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30238662

RESUMO

Flow cytometry is increasingly used in research and also in clinical andrology. Recent developments in instrumentation, availability of probes and bioinformatics expand the possibilities of flow cytometry well beyond the classical two parametric analyses in use. In this paper, an overview of recent developments in flow cytometry will be presented under the perspective of the authors; aspects such a multicolor assays and computational cytometry will be discussed as well.


Assuntos
DNA/análise , Citometria de Fluxo , Mitocôndrias/fisiologia , Espermatozoides/fisiologia , Animais , Membrana Celular/fisiologia , Corantes , Masculino , Mitocôndrias/ultraestrutura , Espermatozoides/ultraestrutura
20.
Phys Rev Lett ; 120(25): 258001, 2018 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-29979071

RESUMO

Inspired by recent experimental observations of patterning at the membrane of a living cell, we propose a generic model for the dynamics of a fluctuating interface driven by particlelike inclusions which stimulate its growth. We find that the coupling between interfacial and inclusions dynamics yields microphase separation and the self-organization of traveling waves. These patterns are strikingly similar to those detected in experiments on biological membranes. Our results further show that the active growth kinetics do not fall into the Kardar-Parisi-Zhang universality class for growing interfaces, displaying instead a novel superposition of scaling and sustained oscillations.


Assuntos
Membrana Celular/fisiologia , Movimento Celular/fisiologia , Proteínas de Membrana/fisiologia , Modelos Biológicos , Modelos Teóricos , Processos de Crescimento Celular/fisiologia , Membrana Celular/metabolismo , Proteínas de Membrana/metabolismo
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