Contribution of HSP90 Cleavage to the Cytotoxic Effect of Suberoylanilide Hydroxamic Acid In Vivo and the Involvement of TXNIP in HSP90 Cleavage.

Heat shock protein (HSP) 90 is expressed in most living organisms, and several client proteins of HSP90 are necessary for cancer cell survival and growth. Previously, we found that HSP90 was cleaved by histone deacetylase (HDAC) inhibitors and proteasome inhibitors, and the cleavage of HSP90 contributes to their cytotoxicity in K562 leukemia cells. In this study, we first established mouse xenograft models with K562 cells expressing the wild-type or cleavage-resistant mutant HSP90ß and found that the suppression of tumor growth by the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was interrupted by the mutation inhibiting the HSP90 cleavage in vivo. Next, we investigated the possible function of thioredoxin interacting protein (TXNIP) in the HSP90 cleavage induced by SAHA. TXNIP is a negative regulator for thioredoxin, an antioxidant protein. SAHA transcriptionally induced the expression of TXNIP in K562 cells. HSP90 cleavage was induced by SAHA also in the thymocytes of normal mice and suppressed by an anti-oxidant and pan-caspase inhibitor. When the thymocytes from the TXNIP knockout mice and their wild-type littermate control mice were treated with SAHA, the HSP90 cleavage was detected in the thymocytes of the littermate controls but suppressed in those of the TXNIP knockout mice suggesting the requirement of TXNIP for HSP90 cleavage. We additionally found that HSP90 cleavage was induced by actinomycin D, ß-mercaptoethanol, and p38 MAPK inhibitor PD169316 suggesting its prevalence. Taken together, we suggest that HSP90 cleavage occurs also in vivo and contributes to the anti-cancer activity of various drugs in a TXNIP-dependent manner.

Antimicrobial and anti-inflammatory activity of Cystatin C on human gingival fibroblast incubated with Porphyromonas gingivalis.

Background: Periodontal disease is considered one of the most prevalent chronic infectious diseases, often leading to the disruption of tooth-supporting tissues, including alveolar bone, causing tooth mobility and loss. Porphyromonas gingivalis is considered the major etiological agent of this disease, having a plethora of virulence factors, including, lipopolysaccharides (LPS), hemolysins, and proteinases. Antimicrobial peptides are one of the main components of the innate immune response that inhibit the growth of P. gingivalis. The aim of this study was to analyze the antimicrobial activity of cystatin C and to assess the effect on the inflammatory and anti-inflammatory cytokines, the production of reactive oxygen species, and in the release of nitric oxide by human gingival fibroblasts incubated with P. gingivalis in the presence and absence of cystatin C. Methods: P. gingivalis ATCC 33277 was exposed to cystatin C for 24h and co-cultured with human gingival fibroblasts (HGFs) ATCC CRL-2014. The effect of cystatin on growth of P. gingivalis and HGFs was evaluated. Pro-inflammatory (TNFα, IL-1ß) and anti-inflammatory (IL-10) cytokines were determined by ELISA in the supernatants of HGFs incubated with P. gingivalis exposed to cystatin C. Additionally, nitrites and reactive oxygen species (ROS) production were evaluated. Results: Cystatin Cinhibited the growth of P. gingivalis without affecting HGFs. Incubation of HGFs with P. gingivalis led to a significant increase of TNF-α and IL-1ß. In contrast, HGFs incubated with P. gingivalis exposed to cystatin C showed a decreased production of both cytokines, whereas IL-10 was enhanced. Incubation of HGFs with P. gingivalis led to an increase of nitric oxide (NO) and ROS production, which was reduced in the presence of the peptide. Conclusions: Cystatin C inhibits the growth of P. gingivalis and decreases the inflammatory cytokines, ROS, and NO production during infection of HGFs with P. gingivalis. Knowledge on the antimicrobial and immunomodulatory properties of cystatin C could aid in the design of new therapeutic approaches to facilitate the elimination of this bacterium to improve the treatment of periodontal disease.

Computer Aided Drug Design Methodologies with Natural Products in the Drug Research Against Alzheimer's Disease.

Natural products are compounds isolated from plants that provide a variety of lead structures for the development of new drugs by the pharmaceutical industry. The interest in these substances increases because of their beneficial effects on human health. Alzheimer's disease (AD) affects occur in about 80% of individuals aged 65 years. AD, the most common cause of dementia in elderly people, is characterized by progressive neurodegenerative alterations, as decrease of cholinergic impulse, increased toxic effects caused by reactive oxygen species and the inflammatory process that the amyloid plaque participates. In silico studies is relevant in the process of drug discovery; through technological advances in the areas of structural characterization of molecules, computational science and molecular biology have contributed to the planning of new drugs used against neurodegenerative diseases. Considering the social impairment caused by an increased incidence of disease and that there is no chemotherapy treatment effective against AD; several compounds are studied. In the researches for effective neuroprotectants as potential treatments for Alzheimer's disease, natural products have been extensively studied in various AD models. This study aims to carry out a literature review with articles that address the in silico studies of natural products aimed at potential drugs against Alzheimer's disease (AD) in the period from 2015 to 2021.

Impact of ETNK1 somatic mutations on phosphoethanolamine synthesis, ROS production and DNA damage.

Recently we showed that Ethanolamine Kinase 1 (ETNK1) mutations cause a decreased synthesis of phosphoethanolamine, and that phosphoethanolamine is able to modulate mitochondrial activity through competition with succinate for complex II. The decreased phosphoethanolamine concentration leads to increased mitochondria activity and reactive oxygen species production, which causes the accumulation of new mutations.

Reactive Oxygen Species and Oxidative Stress in the Pathogenesis and Progression of Genetic Diseases of the Connective Tissue.

Connective tissue is known to provide structural and functional "glue" properties to other tissues. It contains cellular and molecular components that are arranged in several dynamic organizations. Connective tissue is the focus of numerous genetic and nongenetic diseases. Genetic diseases of the connective tissue are minority or rare, but no less important than the nongenetic diseases. Here we review the impact of reactive oxygen species (ROS) and oxidative stress on the onset and/or progression of diseases that directly affect connective tissue and have a genetic origin. It is important to consider that ROS and oxidative stress are not synonymous, although they are often closely linked. In a normal range, ROS have a relevant physiological role, whose levels result from a fine balance between ROS producers and ROS scavenge enzymatic systems. However, pathology arises or worsens when such balance is lost, like when ROS production is abnormally and constantly high and/or when ROS scavenge (enzymatic) systems are impaired. These concepts apply to numerous diseases, and connective tissue is no exception. We have organized this review around the two basic structural molecular components of connective tissue: The ground substance and fibers (collagen and elastic fibers).

Interplay between inflammation and cancer.

Tumor-promoting inflammation is one of the hallmarks of cancer. It has been shown that cancer development is strongly influenced by both chronic and acute inflammation process. Progress in research on inflammation revealed a connection between inflammatory processes and neoplastic transformation, the progression of tumour, and the development of metastases and recurrences. Moreover, the tumour invasive procedures (both surgery and biopsy) affect the remaining tumour cells by increasing their survival, proliferation and migration. One of the concepts explaining this phenomena is an induction of a wound healing response. While in normal tissue it is necessary for tissue repair, in tumour tissue, induction of adaptive and innate immune response related to wound healing, stimulates tumour cell survival, angiogenesis and extravasation of circulating tumour cells. It has become evident that certain types of immune response and immune cells can promote tumour progression more than others. In this review, we focus on current knowledge on carcinogenesis and promotion of cancer growth induced by inflammatory processes.

Maduración pulmonar fetal: efectos sobre la morbilidad respiratoria en prematuros tardíos / Fetal pulmonary maturation: effects on respiratory morbidity in late preterm infants

INTRODUCCIÓN: Los recién nacidos entre las 34 y las 36 semanas de gestación (SEG), definidos actualmente como "prematuros tardíos" (RNPTT) requieren en mayor frecuencia de internación en unidades de cuidados intensivos neonatales, siendo la morbilidad respiratoria una de las principales causas de internación. El uso de corticoides prenatales ha demostrado mejorar la función pulmonar en prematuros extremos (<27,6 SEG), muy prematuros (28-31,6 SEG) y prematuros moderados, (32-36,6 SEG) pero no han sido evaluados en forma extensa en el período prematuro tardío y no existen datos concluyentes al respecto. OBJETIVO: Comparar la frecuencia en que se presenta la morbilidad respiratoria en RNPTT con o sin maduración pulmonar previa. Establecer los factores asociados a morbilidad respiratoria en RNPTT. Comparar los pacientes RNPTT con y sin maduración pulmonar: los requerimientos de internación en general, requerimiento de internación por morbilidad respiratoria y en estos, días de oxigenoterapia y necesidad de ARM y/o VNI. MÉTODO: Diseño observacional, retrospectivo y analítico. Población constituida por todos los RNPTT que nacieron en la CURF entre el 1 de enero de 2017 y el 31 de diciembre de 2017. Las variables maternas y neonatales se compararán entre los dos grupos RNPTT con o sin maduración pulmonar. La frecuencia de presentación de la morbilidad respiratoria entre los RNPTT con o sin maduración pulmonar, los factores asociados a morbilidad respiratoria, los requerimientos de internación y necesidad de ARM y VNI se compararon con la prueba de chicuadrado siendo estadísticamente significativa la diferencia entre los mismos con P ≤0,05. Los días de internación se compararon mediante la prueba de T de Student. El Software que se utilizó para procesar los datos estadísticos será el SPSS versión 11.0 (Chicago, IL). RESULTADOS: De los RNPTT estudiados (160) N=86 (53.7 %) recibieron corticoides prenatales completos. La edad gestacional media (DE) de administración fueron 35,2 (2,2) semanas. La frecuencia de morbilidad respiratoria fue de 21,2%. No hubo diferencia en la frecuencia de morbilidad respiratoria global entre ambos grupos (p 0,3777). El sexo masculino (51,3% vs 49.0%; p= 0,0034) la APP (34,09%; p= 0,0197) y morbilidad materna (preeclampsia, app, diabetes gestacional, corioamnionitis, RPM, placenta previa, HIE) (70,65%; p= 0,0062) se asociaron a morbilidad respiratoria. No hubo diferencias en el requerimiento de internación ni en el número de días de internación entre ambos grupos. Tampoco se observó diferencias en el requerimiento de oxígeno, ARM, VNI, uso de surfactante y necesidad de reanimación. Tampoco se hallaron diferencias en la frecuencia de enfermedad de membrana hialina, taquipnea transitoria del recién nacido, neumotórax. Hubo tendencia a una disminución de la frecuencia de SDRA (6,35 % vs 33.33%, p= 0,051) en el grupo que recibió maduración pulmonar como así también una mayor frecuencia de apneas 25% (p= 0,0392). CONCLUSIÓN: En este estudio la maduración pulmonar con corticoides no influencio la frecuencia de morbilidad respiratoria global. Sin embargo, al analizar las patologías respiratorias de manera individual, encontramos una tendencia a la disminución de SDRA en el grupo madurado. La frecuencia de apneas fue mayor en el grupo que recibió corticoides lo que requiere un análisis con mayor profundidad. El sexo masculino como así también la APP y morbilidad materna se asociaron a mayor frecuencia de morbilidad respiratoria. (AU)

INTRODUCTION: Newborns between 34 and 36 weeks of gestation (WG), currently defined as "latepreterm infants" (LPTI), require of admission in neonatal intensive care units more frequently, with respiratory morbidity being one of the main causes of hospitalization. The use of prenatal corticosteroids has been shown to improve lung function in extremely preterm (<27.6 WG), very preterm (28-31.6 WG), and moderate preterm infants (32-36.6 WG), but it has not been evaluated extensively in the late-preterm period, leaving no conclusive data in this regard. OBJECTIVES: To compare the frequency of respiratory morbidity in LPTI with and without previous lung maturation. To establish the factors associated with respiratory morbidity in LPTI. • To compare LPTI patients with and without lung maturation: the requirements for hospitalization in general, the need for hospitalization due to respiratory morbidity, and in these cases, days of oxygen therapy and need for MRA and / or NIV. METHOD: Observational, retrospective and analytical design. Population constituted by all LPTI that were born in the CURF between January 1, 2017 and December 31, 2017. Maternal and neonatal variables were compared between LPTI groups with and without lung maturation. The frequency of presentation of respiratory morbidity among LPTI with or without lung maturation, the factors associated with respiratory morbidity, the requirements for hospitalization and the need for MRA and NIV were compared with the chi-square test, considering statistically significant the difference between them with P ≤0.05. Days of hospitalization were compared using the Student's T test. The software used to process the statistical data was the SPSS version 11.0 (Chicago, IL). RESULTS: Of the LPTI studied (160), N = 86 (53.7%) received complete antenatal corticosteroids. Mean gestational age (SD) for administration was 35.2 (2.2) weeks. The frequency of respiratory morbidity was 21.2%. There was no difference in the frequency of overall respiratory morbidity between both groups (p 0.3777). Male sex (51,3% vs 49.0%; p= 0,0034), preterm birth risk (34,09%; p= 0,0197) and maternal morbidity (preeclampsia, preterm birth risk, gestational diabetes, chorioamnionitis, preterm membrane rupture, previous placenta, pregnancy-induced hypertension) (70,65%; p= 0,0062) were associated to respiratory morbidity. There were no differences regarding hospitalization requirement or the number of hospitalization days between both groups. No differences were observed in oxygen requirement, MRA, NIV, use of surfactant and need for resuscitation. No differences were found in the frequency of hyaline membrane disease, newborn transient tachypnea and pneumothorax. There was a tendency to a decrease in the frequency of RDS (6.25% vs 33.33%; p= 0.051), and a higher frequency of apneas (25.0% vs 0%; p= 0.0392) in the group of patients who received lung maturation. CONCLUSION: In this study, pulmonary maturation with corticosteroids did not influence the frequency of global respiratory morbidity. However, when analyzing respiratory pathologies individually, we found a tendency to decrease of RDS in the matured group. The frequency of apneas was higher in the group that received corticosteroids, which requires further analysis. Male sex as well as preterm birth risk and maternal morbidity were associated to a higher frequency of respiratory morbidity

Ramalin, an antioxidant compound derived from Antarctic lichen, prevents progression of liver fibrosis induced by dimethylnitrosamine (DNM) in rats.

Hepatic fibrosis is characterized by the excessive accumulation of extracellular matrix (ECM), primarily collagen, within the liver. Because reactive oxygen species (ROS) has been implicated in its pathogenesis, the use of antioxidants as a potential treatment has been broadly explored. Here, we investigated the hepatoprotective properties of ramalin (RM), a compound extracted from the Antarctic lichen Ramalina terebrata, against hepatic fibrosis in vitro and in vivo. RM suppressed hepatic stellate cell (HSC) activation in vitro without any significant signs of adverse effects on the cells tested, and the accumulation of ECM was dramatically reduced in the liver tissue. Oral administration of RM in rats noticeably improved the gross appearance of the liver with increased body and liver weight relative to the DMN injected rats, and all of the serum biochemical markers returned to the normal range. RM treatment have ameliorated hepatic fibrosis in rats induced by DMN by repressing α-smooth muscle actin (α-SMA) and upregulating heme oxygenase-1 (HO-1). In addition, RM significantly reduced collagen accumulation, and levels of malondialdehyde (MDA) and hydroxyproline (HP) in the liver tissue of DMN injected rats. The efficacy exerted by RM was through erythroid 2-related factor 2 (Nrf2) mediated antioxidant response proteins such as HO-1 and NAD(P)H quinone dehydrogenase 1 (NQO-1). Our results show the beneficial effect of RM against the progression of hepatic fibrosis.

Effects of δ-tocotrienol on ochratoxin A-induced nephrotoxicity in rats.

Ochratoxin A (OTA), is a natural contaminant of the food chain worldwide involved in the development of different type of cancers in animals and humans. Several studies suggested that oxidative damage might contribute to increase the cytotoxicity and carcinogenicity capabilities of OTA. The aim of this study was to evaluate the possible protective effect of δ-tocotrienol (Delta), a natural form of vitamin E, against OTA-induced nephrotoxicity. Male Sprague-Dawley rats were treated with OTA and/or Delta by gavage for 14 days. Our results shown that OTA treatment induced the increase of reactive oxigen species production correlated to a strong reduction of Glomerular Filtration Rate (GFR) and absoluted fluid reabsorption (Jv) with conseguent significant increase in blood pressure. Consistent, we noted in the kidney of rats treated with OTA, an increase in malondialdheyde and dihydroethidium production and a reduction of the activity of the catalase, superoxide dismutase, and glutathione peroxidase. Conversly, in the rat group subjected to the concomitant treatment OTA plus Delta, we observed the restored effect, compared the OTA treatment group, on blood pressure, GFR, Jv, and all activities of renal antioxidant enzymes. Finally, as far as concern the tissue damage induced by OTA and measured evaluating fibronectin protein levels, we observed that in OTA plus Delta group this effect is not restored. Our findings releval that a mechanism underlying the renal toxicity induced by OTA is the oxidative stress and provide a new rationale to use a Delta in order to protect, at least in part, against OTA-induced nephrotoxicity.

Tumor-Derived Microvesicles Modulate Antigen Cross-Processing via Reactive Oxygen Species-Mediated Alkalinization of Phagosomal Compartment in Dendritic Cells.

Dendritic cells (DCs) are the only antigen-presenting cells able to prime naïve T cells and cross-prime antigen-specific CD8+ T cells. Their functionality is a requirement for the induction and maintenance of long-lasting cancer immunity. Albeit intensively investigated, the in vivo mechanisms underlying efficient antigen cross-processing and presentation are not fully understood. Several pieces of evidence indicate that antigen transfer to DCs mediated by microvesicles (MVs) enhances antigen immunogenicity. This mechanism is also relevant for cross-presentation of those tumor-associated glycoproteins such as MUC1 that are blocked in HLA class II compartment when internalized by DCs as soluble molecules. Here, we present pieces of evidence that the internalization of tumor-derived MVs modulates antigen-processing machinery of DCs. Employing MVs derived from ovarian cancer ascites fluid and established tumor cell lines, we show that MV uptake modifies DC phagosomal microenvironment, triggering reactive oxygen species (ROS) accumulation and early alkalinization. Indeed, tumor MVs carry radical species and the MV uptake by DCs counteracts the chemically mediated acidification of the phagosomal compartment. Further pieces of evidence suggest that efficacious antigen cross-priming of the MUC1 antigen carried by the tumor MVs results from the early signaling induced by MV internalization and the function of the antigen-processing machinery of DCs. These results strongly support the hypothesis that tumor-derived MVs impact antigen immunogenicity by tuning the antigen-processing machinery of DCs, besides being carrier of tumor antigens. Furthermore, these findings have important implications for the exploitation of MVs as antigenic cell-free immunogen for DC-based therapeutic strategies.

Alkynyl gold(I) complex triggers necroptosis via ROS generation in colorectal carcinoma cells.

Given the rise of apoptosis-resistant tumors, there exist a growing interest in developing new drugs capable of inducing different types of cell death to reduce colorectal cancer-related death rates. As apoptosis and necroptosis do not share cellular machinery, necroptosis induction may have a great therapeutic potential on those apoptosis-resistant cancers, despite the inflammatory effects associated with it. We have synthesized an alkynyl gold(I) complex [Au(CC-2-NC5H4)(PTA)] whose anticancer effect was tested on the colorectal adenocarcinoma Caco-2 cell line. With regard to its mechanism of action, this gold complex enters the mitochondria and disrupts its normal function, leading to an increase in ROS production, which triggers necroptosis. Necroptosis induction has been found dependent of TNF-α (Tumor necrosisfactor α) and TNFR1(Tumor necrosisfactor receptor 1) binding, RIP1(Receptor-Interacting Protein 1) activation and NF-κB (Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells) signaling. Moreover, the antitumor potential of [Au(CC-2-NC5H4)(PTA)] has also been confirmed on the 3D cancer model spheroid. Overall, the obtained data show firstly that gold complexes might have the ability of inducing necroptosis, and secondarily that our compound [Au(CC-2-NC5H4)(PTA)] is an interesting alternative to current chemotherapy drugs in cases of apoptosis resistance.

Oxidative stress, microRNAs and cytosolic calcium homeostasis.

Reactive oxygen species increase cytosolic [Ca(2+)], (Cai), and also modulate the expression of some microRNAs (miRNAs), however the link among oxidative stress, miRNAs and Cai is poorly characterized. In this review we have focused on three groups of miRNAs: (a) miRNAs that are modulated both by ROS and Cai: miR-181a and miR-205; (b) miRNAs that are modulated by ROS and have an effect on Cai: miR-1, miR-21, miR-24, miR-25, miR-185 and miR-214; (c) miRNAs that modulate both ROS and Cai: miR-133; miR-145, miR-495, and we have analyzed their effects on cell signaling and cell function. Finally, in the last section we have examined the role of these miRNAs in the skin, under conditions associated with enhanced oxidative stress, i.e. skin aging, the response to ultraviolet light and two important skin diseases, psoriasis and atopic dermatitis. It is apparent that although some experimental evidence is already available on (a) the role of Cai in miRNAs expression and (b) on the ability of some miRNAs to modulate Cai-dependent intracellular signaling, these research lines are still largely unexplored and represent important areas of future studies.

Effectiveness of hyperbaric oxygen for experimental treatment of schistosomiasis mansoni using praziquantel-free and encapsulated into liposomes: assay in adult worms and oviposition.

The treatment of schistosomiasis depends on a single drug: praziquantel (PZQ). However, this treatment presents limitations such as low and/or erratic bioavailability that can contribute to cases of tolerance. Improvements to the available drug are urgently needed and studies with a controlled system of drug release, like liposomes, have been gaining prominence. The present study evaluated the activity and synergy between liposomal-praziquantel (lip.PZQ) and hyperbaric oxygen therapy (HBO). Mice received doses of 60 or 100mg/kg PZQ or lip.PZQ, 50 days post-infection, and after the treatment, were exposed to HBO (3 atmosphere absolute - ATA) for 1h. The viability of adult worms and oviposition were analyzed, by necropsy and Kato-Katz examination performed after 15 days of treatment. A concentration of 100mg/kg of lip.PZQ+HBO was more effective (48.0% reduction of worms, 83.3% reduction of eggs/gram of feces) and 100% of the mice had altered of oograms (indicating interruption of oviposition) compared to other treatments and to the Control group (infected and untreated). It is known that PZQ requires participation of the host immune system to complete its antischistosomal activity and that HBO is able to stimulate the immune system. The drug became more available in the body when incorporated into liposomes and, used with HBO, the HBO worked as an adjuvant. This explains the decreases of oviposition and worms recovered form hepatic portal system.

Biomarcadores de estresse oxidativo em fumantes crônicos e em portadores de insuficiência respiratória crônica (IResC) durante oxigenoterapia domiciliar prolongada (ODP) / Biomarkers of oxidative stress in patients with chronic respiratory insuficiency (CResI) during long term oxigen therapy (LTOT)

Objetivo: Este trabalho consistiu em avaliar biomarcadores de estresse oxidativo em portadores de insuficiência respiratória crônica (IResC) em três momentos: antes, após 7 e ao longo de 270 dias de oxigenoterapia domiciliar prolongada (ODP). Métodos: Foram medidas as atividades das enzimas catalase (CAT) e glutationa redutase (GR) no hemolisado, as concentrações de hemoglobina, lactato e ácido úrico (AU) no sangue total e as concentrações de grupamentos sulfidrilas totais (GST) e proteínas carboniladas (PC) no plasma desses pacientes por método espectrofotométrico. A saturação de oxigênio (SpO2) no sangue foi medida através de oxímetro de pulso. Comparamos, num primeiro momento indivíduos fumantes com pacientes com IResC e ambos com o grupo-controle, de não fumantes. Resultados: Observou-se que, embora os dois grupos possuam níveis aumentados de estresse oxidativo, este foi muito maior no grupo IResC, representado principalmente pela diminuição nas atividades das enzimas CAT, GR e concentração plasmática de GST. Após sete dias de tratamento com oxigênio houve um aumento na SpO2 (P < 0,05), CAT, GR e AU (P < 0,05). Por outro lado, a concentração de GST se manteve diminuída nesse período (P < 0,05). Os dados referentes aos pacientes submetidos a ODP ao longo de 270 dias mostraram que somente a atividade da GR se apresentou significativamente diminuída nesse período (P < 0.05). Conclusão: A hipoxemia crônica produz efeitos prejudiciais que não são revertidos com a administração prolongada de oxigênio, que não é capaz, portanto, de impedir a evolução clínica da doença...

Alterações nos parâmetros fisiológicos dos recém-nascidos sob oxigenoterapia na coleta de gasometria / Alterations in the physiological parameters of newborns using oxygen therapy in the collection of blood gases

Objetivo: Identificar as alterações que ocorrem nos parâmetros fisiológicos dos recém-nascidos sob oxigenoterapia na coleta de gasometria arterial, comparando os momentos imediatamente antes, imediatamente depois, e cinco minutos depois do procedimento. Métodos: Estudo longitudinal, do tipo antes e depois,. Amostra composta por 67 recém-nascidos sob oxigenoterapia que receberam punção arterial para gasometria. Resultados: O grupo de recém-nascidos em Oxi-Hood sofreu alterações significativas (p<0,05) na frequência cardíaca, pulso e saturação de oxigênio. Os recém-nascidos em ventilação mecânica obtiveram alterações de frequência respiratória e pulso e aqueles sob CPAP nasal não mostraram instabilidade dos parâmetros fisiológicos. Conclusão: O estímulo doloroso causado pela coleta de gasometria nos recém-nascidos mostrou variações de todos os parâmetros fisiológicos, porém, para tal procedimento, as alterações foram diferentes em cada modalidade de oxigenoterapia. .

Objective: To identify the changes that occur in the physiological parameters of newborns under oxygen therapy during the collection of arterial blood gases, comparing the moments immediately before, immediately after, and five minutes after the procedure. Methods: A longitudinal study, of the before and after research design. The sample was composed of 67 newborns under oxygen therapy that had an arterial puncture for blood gas analysis. Results: The group of newborns in an Oxyhood experienced significant alterations (p<0.05) in heart rate, pulse and oxygen saturation. Newborns on mechanical ventilation had alterations in respiratory rate and pulse, while those with nasal CPAP showed no instability in physiological parameters. Conclusion: The painful stimulus caused by the collection of blood gases in newborns showed changes in all physiological parameters, however, for such a procedure, the changes were different for each mode of oxygen therapy. .

Metabolic flux analysis of recombinant Pichia pastoris growing on different glycerol/methanol mixtures by iterative fitting of NMR-derived (13)C-labelling data from proteinogenic amino acids.

The yeast Pichia pastoris has emerged as one of the most promising yeast cell factories for the production of heterologous proteins. The readily available genetic tools and the ease of high-cell density cultivations using methanol or glycerol/methanol mixtures are among the key factors for this development. Previous studies have shown that the use of mixed feeds of glycerol and methanol seem to alleviate the metabolic burden derived from protein production, allowing for higher specific and volumetric process productivities. However, initial studies of glycerol/methanol co-metabolism in P. pastoris by classical metabolic flux analyses using (13)C-derived Metabolic Flux Ratio (METAFoR) constraints were hampered by the reduced labelling information obtained when using C3:C1 substrate mixtures in relation to the conventional C6 substrate, that is, glucose. In this study, carbon flux distributions through the central metabolic pathways in glycerol/methanol co-assimilation conditions have been further characterised using biosynthetically directed fractional (13)C labelling. In particular, metabolic flux distributions were obtained under 3 different glycerol/methanol ratios and growth rates by iterative fitting of NMR-derived (13)C-labelling data from proteinogenic amino acids using the software tool (13)CFlux2. Specifically, cells were grown aerobically in chemostat cultures fed with 80:20, 60:40 and 40:60 (w:w) glycerol/methanol mixtures at two dilutions rates (0.05 hour(-1) and 0.16 hour(-1)), allowing to obtain additional data (biomass composition and extracellular fluxes) to complement pre-existing datasets. The performed (13)C-MFA reveals a significant redistribution of carbon fluxes in the central carbon metabolism as a result of the shift in the dilution rate, while the ratio of carbon sources has a lower impact on carbon flux distribution in cells growing at the same dilution rate. At low growth rate, the percentage of methanol directly dissimilated to CO2 ranges between 50% and 70%. At high growth rate the methanol is completely dissimilated to CO2 by the direct pathway, in the two conditions of highest methanol content.

AMPKα1 controls hepatocyte proliferation independently of energy balance by regulating Cyclin A2 expression.

BACKGROUND: AMP-activated protein kinase (AMPK) is an evolutionarily conserved sensor of cellular energy status that contributes to restoration of energy homeostasis by slowing down ATP-consuming pathways and activating ATP-producing pathways. Unexpectedly, in different systems, AMPK is also required for proper cell division. In the current study, we evaluated the potential effect of the AMPK catalytic subunit, AMPKα1, on hepatocyte proliferation. METHODS: Hepatocyte proliferation was determined in AMPKα1 knockout and wild-type mice in vivo after two thirds partial hepatectomy, and in vitro in primary hepatocyte cultures. The activities of metabolic and cell cycle-related signaling pathways were measured. RESULTS: After partial hepatectomy, hepatocytes proliferated rapidly, correlating with increased AMPK phosphorylation. Deletion of AMPKα1 delayed liver regeneration by impacting on G1/S transition phase. The proliferative defect of AMPKα1-deficient hepatocytes was cell autonomous, and independent of energy balance. The priming phase, lipid droplet accumulation, protein anabolic responses and growth factor activation after partial hepatectomy occurred normally in the absence of AMPKα1 activity. By contrast, mRNA and protein expression of cyclin A2, a key driver of S phase progression, were compromised in the absence of AMPK activity. Importantly, AMPKα1 controlled cyclin A2 transcription mainly through the ATF/CREB element. CONCLUSIONS: Our study highlights a novel role for AMPKα1 as a positive regulator of hepatocyte division occurring independently of energy balance.

Modulation of the antioxidant/pro-oxidant balance, cytotoxicity and antiviral actions of grape seed extracts.

Grape seed extracts (GSEs) were investigated in yeast cells harbouring defects in their antioxidant system (regarding the cellular growth and growth recovery from H2O2 insult). GSEs antioxidant activity was detected in wild-type and mutant strains Δcta1, Δgsh1 and Δoye2glr1, while pro-oxidant activity in Δsod1 cells was seen. Assessment of proliferation of prostate cancer PC3 and HBV-replicating HepG2 2.2.15 cells treated with GSEs has shown higher cytotoxicity of red grape seed extract (RW) than white grape seed extract (WW) subjective to dose and period of administration. No antiviral effect was detected by measuring the secreted virion particles in HepG2 2.2.15 cells treated with GSEs. The GSEs play a dual antioxidant/pro-oxidant role in vivo according with the cellular antioxidant system deficiencies and exhibit cytotoxic properties in PC3 and HepG2 2.2.15 cell lines, but no antiviral action against HBV.

Hipoxia en la malignidad del cáncer: revisión / Hypoxia in cancer malignity: review

La hipoxia es una característica común en los tumores sólidos, contribuyendo local y sistémicamente a la progresión tumoral, además de la falta de respuesta a la radioterapia y quimioterapia, lo cual provoca un incremento en la probabilidad de recurrencia de un tumor. El factor de transcripción HIF-1 es el mayor regulador de la adaptación del tumor a la hipoxia, induciendo la expresión de muchos genes que permiten a las células sobrevivir en estas condiciones. Los eventos dependientes de HIF-1 que están implicados en la progresión tumoral son múltiples, destacando la proliferación, el metabolismo de la glucosa, la angiogénesis y la metástasis. Es fundamental investigar más acerca de los mecanismos de acción del factor HIF-1 ya que es factible encontrar inhibidores que puedan usarse terapéuticamente contra el cáncer. En este trabajo se hace una revisión del papel que desempeña el factor HIF-1 en la hipoxia, así como su implicación en la angiogénesis y la metástasis.

Hypoxia is a common characteristic of solid tumors. It contributes to local and systemic tumor progression, as well as the lack of response to radio and chemotherapy, therefore increasing the probability of tumor recurrence. The HIF-1 transcription factor is the main regulator of tumor adaptation to hypoxia stress, stimulating the expression of many genes that allow cells to survive under these conditions. Products dependent on HIF-1 factor are involved in processes of tumor progression, such as proliferation, glucose metabolism, ph-acidosis, angiogenesis and metastasis. It has become increasingly necessary to gain knowledge on the HIF-1 mechanisms of action, since it is possible to find inhibitors that could be used therapeutically against cancer. In this review, a summary is given on the role that the HIF-1 factor plays in hypoxia, as well as its implications on angiogenesis and metastasis

Saturação venosa central e mista de oxigênio no choque séptico: existe diferença clinicamente relevante? / Central and mixed venous oxygen saturation in septic shock: is there a clinically relevant difference?

INTRODUÇÃO: A medida da saturação venosa central de oxigênio (SvcO2) tem sido proposta como alternativa a saturação venosa mista (SvO2), com grau de concordância variável nos dados atualmente disponíveis. Esse estudo objetivou avaliar as possíveis diferenças entre a SvO2 e a SvcO2 ou saturação venosa atrial de oxigênio (SvaO2), com ênfase na interferência do débito cardíaco, e o impacto delas no manejo clínico do paciente séptico. MÉTODOS: Estudo prospectivo observacional em pacientes com choque séptico monitorizados com cateter de artéria pulmonar. Foi obtido sangue simultaneamente para determinação da SvcO2, SvO2 e SvaO2. Realizado testes de correlação linear (significativos se p<0,05) e análise de concordância (Bland-Altman) entre as amostras e nos subgupos de débito cardíaco. Além disso, foi avaliada a concordância entre condutas clínicas baseadas nessas medidas. RESULTADOS: Foram obtidas 61 medidas de 23 pacientes, mediana de idade de 65,0 (49,0-75,0) anos, APACHE II médio de 27,7±6,3. Os valores médios encontrados foram 72,20±8,26 por cento, 74,61±7,60 por cento e 74,64±8,47 por cento para SvO2, SvcO2 e SvaO2. O teste de correlação linear mostrou baixa correlação tanto entre a SvO2 e a SvcO2 (r=0,61, p<0,0001) quanto entre a SvO2 e a SvaO2 (r=0,70, p<0,0001). As concordâncias entre SvcO2/SvO2 e SvaO2/SvO2 foram, respectivamente, de -2,40±1,96 (-16,20 e 11,40) e -2,40±1,96 (-15,10 e 10,20), sem diferença nos subgrupos de débito cardíaco. Não houve concordância na conduta clínica em 27,8 por cento dos casos, tanto entre SvcO2/SvO2 como de SvaO2/SvO2. CONCLUSÃO: Esse estudo mostra que a correlação e a concordância entre SvO2 e SvcO2 é baixa e pode levar a condutas clínicas diferentes.

INTRODUCTION: Central venous oxygen saturation (SvcO2) has been proposed as an alternative for mixed venous oxygen saturation (SvO2), with a variable level of acceptance according to available data. This study aimed to evaluate possible differences between SvO2 and SvcO2 or atrial venous saturation (SvaO2), with emphasis on the role of cardiac output and their impact on clinical management of the septic patient. METHODS: This is an observational, prospective study of patients with septic shock monitored by pulmonary artery catheter. Blood was obtained simultaneously for SvcO2, SvO2 and SvaO2 determination. Linear correlation (significant if p<0.05) and agreement analysis (Bland-Altman) were performed with samples and subgroups according to cardiac output. Moreover, agreement about clinical management based on these samples was evaluated. RESULTS: Sixty one measurements from 23 patients were obtained, median age of 65.0 (49.0-75.0) years and mean APACHE II of 27.7±6.3. Mean values of SvO2, SvcO2 and SvaO2 were 72.20±8.26 percent, 74.61±7.60 percent and 74.64±8.47 percent. Linear correlation test showed a weak correlation between SvO2 and SvcO2 (r=0.61, p<0.0001) and also between SvO2 and SvaO2 (r=0.70, p<0.0001). Agreements between SvcO2/SvO2 and SvaO2/SvO2 were -2.40±1.96 (-16.20 and 11.40) and -2.40±1.96 (-15.10 and 10.20), respectively, with no difference in the cardiac output subgroups. No agreement was found in clinical management for 27.8 percent of the cases, both for SvcO2/SvO2 and for SvaO2/SvO2. CONCLUSION: This study showed that the correlation and agreement between SvO2 and SvcO2 is weak and may lead to different clinical management.