RESUMO
At labor, the myometrium is infiltrated by a massive influx of macrophages that secrete high levels of pro-inflammatory cytokines inducing the expression of specific labor-associated markers. However, the interactions between myocytes and macrophages and the role of macrophages in the myometrium at labor remain to be elucidated. In this work, we studied the role of myometrium-infiltrated macrophages and their interaction with myocytes in lipopolysaccharide-induced preterm labor. A co-culture model of human primary myometrial cells and macrophages was developed and validated. Collagen lattices were used to evaluate myocyte contraction. Differentiation steps were assessed by (i) phalloidin and vinculin staining for cytoskeleton reorganization, (ii) gap junction protein alpha 1 expression and scrape loading/dye transfer with Lucifer Yellow for gap junction intercellular communication, and (iii) calcium imaging for cell excitability. We demonstrated that macrophages favored lipopolysaccharide-induced contraction and early differentiation of myometrial cells. Transwell assays showed that previous activation of macrophages by lipopolysaccharide was essential for this differentiation and that macrophage/myocyte interactions involved macrophage release of reactive oxygen species (ROS). The effects of macrophage-released ROS in myometrial cell transactivation were mimicked by H2O2, suggesting that superoxide anion is a major intermediate messenger in macrophage/myocyte crosstalk during labor. These novel findings provide the foundation for innovative approaches to managing preterm labor, specifically the use of antioxidants to inhibit the initial stages of labor before the contractile phenotype has been acquired. In addition, the co-culture model developed by our team could be used in future research to decipher pathophysiological signaling pathways or screen/develop new tocolytics.
Assuntos
Macrófagos/fisiologia , Miométrio/citologia , Parto/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Contração Uterina/fisiologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Feminino , Humanos , Peróxido de Hidrogênio/farmacologia , Lipopolissacarídeos/farmacologia , Contração Uterina/efeitos dos fármacosRESUMO
MAIN CONCLUSION: The involvement of a WRKY transcription factor in the regulation of lignan biosynthesis in flax using a hairy root system is described. Secoisolariciresinol is the main flax lignan synthesized by action of LuPLR1 (pinoresinol-lariciresinol reductase 1). LuPLR1 gene promoter deletion experiments have revealed a promoter region containing W boxes potentially responsible for the response to Fusarium oxysporum. W boxes are bound by WRKY transcription factors that play a role in the response to stress. A candidate WRKY transcription factor, LuWRKY36, was isolated from both abscisic acid and Fusarium elicitor-treated flax cell cDNA libraries. This transcription factors contains two WRKY DNA-binding domains and is a homolog of AtWRKY33. Different approaches confirmed LuWRKY36 binding to a W box located in the LuPLR1 promoter occurring through a unique direct interaction mediated by its N-terminal WRKY domain. Our results propose that the positive regulator action of LuWRKY36 on the LuPLR1 gene regulation and lignan biosynthesis in response to biotic stress is positively mediated by abscisic acid and inhibited by ethylene. Additionally, we demonstrate a differential Fusarium elicitor response in susceptible and resistant flax cultivars, seen as a faster and stronger LuPLR1 gene expression response accompanied with higher secoisolariciresinol accumulation in HR of the resistant cultivar.
Assuntos
Linho/genética , Fusarium/fisiologia , Lignanas/biossíntese , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas/farmacologia , Fatores de Transcrição/metabolismo , Ácido Abscísico/farmacologia , Etilenos/farmacologia , Linho/metabolismo , Linho/microbiologia , Biblioteca Gênica , Modelos Biológicos , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Regiões Promotoras Genéticas/genética , Estresse Fisiológico , Fatores de Transcrição/genéticaRESUMO
MAIN CONCLUSION: This study provides new insights into the biosynthesis regulation and in planta function of the lignan yatein in flax leaves. Pinoresinol-lariciresinol reductases (PLR) catalyze the conversion of pinoresinol into secoisolariciresinol (SECO) in lignan biosynthesis. Several lignans are accumulated in high concentrations, such as SECO accumulated as secoisolariciresinol diglucoside (SDG) in seeds and yatein in aerial parts, in the flax plant (Linum usitatissimum L.) from which two PLR enzymes of opposite enantioselectivity have been isolated. While LuPLR1 catalyzes the biosynthesis of (+)-SECO leading to (+)-SDG in seeds, the role(s) of the second PLR (LuPLR2) is not completely elucidated. This study provides new insights into the in planta regulation and function of the lignan yatein in flax leaves: its biosynthesis relies on a different PLR with opposite stereospecificity but also on a distinct expression regulation. RNAi technology provided evidence for the in vivo involvement of the LuPLR2 gene in the biosynthesis of (-)-yatein accumulated in flax leaves. LuPLR2 expression in different tissues and in response to stress was studied by RT-qPCR and promoter-reporter transgenesis showing that the spatio-temporal expression of the LuPLR2 gene in leaves perfectly matches the (-)-yatein accumulation and that LuPLR2 expression and yatein production are increased by methyl jasmonate and wounding. A promoter deletion approach yielded putative regulatory elements. This expression pattern in relation to a possible role for this lignan in flax defense is discussed.
Assuntos
4-Butirolactona/análogos & derivados , Linho/fisiologia , Genes de Plantas/genética , Oxirredutases/genética , Imunidade Vegetal/genética , 4-Butirolactona/biossíntese , Dioxóis , Linho/enzimologia , Linho/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Genes de Plantas/fisiologia , Glucuronidase/metabolismo , Redes e Vias Metabólicas , Oxirredutases/fisiologia , Imunidade Vegetal/fisiologia , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase em Tempo Real , Nicotiana/genéticaRESUMO
ABCD1 and ABCD2 are two closely related ATP-binding cassette half-transporters predicted to homodimerize and form peroxisomal importers for fatty acyl-CoAs. Available evidence has shown that ABCD1 and ABCD2 display a distinct but overlapping substrate specificity, although much remains to be learned in this respect as well as in their capability to form functional heterodimers. Using a cell model expressing an ABCD2-EGFP fusion protein, we first demonstrated by proximity ligation assay and co-immunoprecipitation assay that ABCD1 interacts with ABCD2. Next, we tested in the pxa1/pxa2Δ yeast mutant the functionality of ABCD1/ABCD2 dimers by expressing chimeric proteins mimicking homo- or heterodimers. For further structure-function analysis of ABCD1/ABCD2 dimers, we expressed chimeric dimers fused to enhanced GFP in human skin fibroblasts of X-linked adrenoleukodystrophy patients. These cells are devoid of ABCD1 and accumulate very long-chain fatty acids (C26:0 and C26:1). We checked that the chimeric proteins were correctly expressed and targeted to the peroxisomes. Very long-chain fatty acid levels were partially restored in transfected X-linked adrenoleukodystrophy fibroblasts regardless of the chimeric construct used, thus demonstrating functionality of both homo- and heterodimers. Interestingly, the level of C24:6 n-3, the immediate precursor of docosahexaenoic acid, was decreased in cells expressing chimeric proteins containing at least one ABCD2 moiety. Our data demonstrate for the first time that both homo- and heterodimers of ABCD1 and ABCD2 are functionally active. Interestingly, the role of ABCD2 (in homo- and heterodimeric forms) in the metabolism of polyunsaturated fatty acids is clearly evidenced, and the chimeric dimers provide a novel tool to study substrate specificity of peroxisomal ATP-binding cassette transporters.
Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Peroxissomos/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Animais , Sequência de Bases , Linhagem Celular , Primers do DNA , Dimerização , Humanos , Camundongos , Plasmídeos , Reação em Cadeia da Polimerase , Ratos , Relação Estrutura-AtividadeRESUMO
X-linked adrenoleukodystrophy (X-ALD) is a rare neurodegenerative disorder characterized by the accumulation of very-long-chain fatty acids resulting from a beta-oxidation defect. Oxidative stress and inflammation are also key components of the pathogenesis. X-ALD is caused by mutations in the ABCDI gene, which encodes for a peroxisomal half ABC transporter predicted to participate in the entry of VLCFA-CoA into the peroxisome, the unique site of their beta-oxidation. Two homologous peroxisomal ABC transporters, ABCD2 and ABCD3 have been proven to compensate for ABCD1 deficiency when overexpressed. Pharmacological induction of these target genes could therefore represent an alternative therapy for X-ALD patients. Since LXR activation was shown to repress ABCD2 expression, we investigated the effects of LXR antagonists in different cell lines. Cells were treated with GSK(17) (a LXR antagonist recently discovered from the GlaxoSmithKline compound collection), 22(S)-hydroxycholesterol (22S-HC, another LXR antagonist) and 22R-HC (an endogenous LXR agonist). We observed up-regulation of ABCD2,ABCD3 and CTNNB1 (the gene encoding for beta-catenin, which was recently demonstrated to induce ABCD2 expression) in human HepG2 hepatoma cells and in X-ALD skin fibroblasts treated with LXR antagonists. Interestingly, induction in X-ALD fibroblasts was concomitant with a decrease in oxidative stress. Rats treated with 22S-HC showed hepatic induction of the 3 genes of interest. In human, we show by multiple tissue expression array that expression of ABCD2 appears to be inversely correlated with NR1H3 (LXRalpha) expression. Altogether, antagonists of LXR that are currently developed in the context of dyslipidemia may find another indication with X-ALD.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Receptores Nucleares Órfãos/antagonistas & inibidores , Subfamília D de Transportador de Cassetes de Ligação de ATP , Adrenoleucodistrofia/metabolismo , Ácidos Graxos/análise , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Hidroxicolesteróis/farmacologia , Receptores X do Fígado , Estresse OxidativoRESUMO
The objective of this study was to evaluate the biological activities of the major phytosterols present in argan oil (AO) and in cactus seed oil (CSO) in BV2 microglial cells. Accordingly, we first determined the sterol composition of AO and CSO, showing the presence of Schottenol and Spinasterol as major sterols in AO. While in CSO, in addition to these two sterols, we found mainly another sterol, the Sitosterol. The chemical synthesis of Schottenol and Spinasterol was performed. Our results showed that these two phytosterols, as well as sterol extracts from AO or CSO, are not toxic to microglial BV2 cells. However, treatments by these phytosterols impact the mitochondrial membrane potential. Furthermore, both Schottenol and Spinasterol can modulate the gene expression of two nuclear receptors, liver X receptor (LXR)-α and LXRß, their target genes ABCA1 and ABCG1. Nonetheless, only Schottenol exhibited a differential activation vis-à-vis the nuclear receptor LXRß. Thus Schottenol and Spinasterol can be considered as new LXR agonists, which may play protective roles by the modulation of cholesterol metabolism.
Assuntos
Microglia/efeitos dos fármacos , Receptores Nucleares Órfãos/agonistas , Óleos de Plantas/química , Sitosteroides/farmacologia , Estigmasterol/análogos & derivados , Transportador 1 de Cassete de Ligação de ATP/genética , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Linhagem Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Lipoproteínas/genética , Receptores X do Fígado , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Microglia/citologia , Opuntia/química , Receptores Nucleares Órfãos/genética , Sementes/química , Esteróis/análise , Estigmasterol/síntese química , Estigmasterol/farmacologiaRESUMO
OBJECTIVE: Liver X receptors (LXRs) are oxysterol-activated nuclear receptors that are highly expressed in macrophages and regulate lipid homeostasis and inflammation. Among putative LXR target genes, lysophosphatidylcholine acyltransferase 3 (LPCAT3) involved in the Lands cycle controls the fatty acid composition at the sn-2 position of glycerophospholipids and, therefore, the availability of fatty acids, such as arachidonic acid (AA), used for eicosanoid synthesis. The aim of our study was to determine whether LXRs could regulate the Lands cycle in human macrophages, to assess the consequences in terms of lipid composition and inflammatory response, and to work out the relative contribution of LPCAT3 to the observed changes. APPROACH AND RESULTS: Transcriptomic analysis revealed that LPCAT3 was upregulated by LXR agonists in human macrophages. Accordingly, LXR stimulation significantly increased lysophospholipid acyltransferase activity catalyzed by LPCAT3. Lipidomic analysis demonstrated that LXR activation increased the AA content in the polar lipid fraction, specifically in phosphatidylcholines. The LXR-mediated effects on AA distribution were abolished by LPCAT3 silencing, and a redistribution of AA toward the neutral lipid fraction was observed in this context. Finally, we observed that preconditioning of human macrophages by LXR agonist treatment increased the release of arachidonate-derived eicosanoids, such as prostaglandin E2 and thromboxane after lipopolysaccharide stimulation, with a significant attenuation by LPCAT3 silencing. CONCLUSIONS: Altogether, our data demonstrate that the LXR-mediated induction of LPCAT3 primes human macrophages for subsequent eicosanoid secretion by increasing the pool of AA, which can be mobilized from phospholipids.
Assuntos
1-Acilglicerofosfocolina O-Aciltransferase/genética , Ácido Araquidônico/metabolismo , Eicosanoides/metabolismo , Inflamação/genética , Macrófagos/metabolismo , Receptores Nucleares Órfãos/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferase/metabolismo , Células Cultivadas , Dimetil Sulfóxido/farmacologia , Dinoprostona/metabolismo , Humanos , Inflamação/fisiopatologia , Receptores X do Fígado , Macrófagos/efeitos dos fármacos , Análise em Microsséries , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Receptores Nucleares Órfãos/efeitos dos fármacos , RNA Mensageiro/análise , Sensibilidade e Especificidade , Regulação para Cima/genéticaRESUMO
INTRODUCTION: Metabolic and bariatric surgery (MBS) has experienced considerable growth, addressing the challenges of obesity and its complications. The lack of a comprehensive bibliometric analysis in Latin America motivates this study, highlighting the need to understand the evolution of research in this area and its impact on clinical decision-making and health policies. METHODOLOGY: A cross-sectional bibliometric study was carried out using the Scopus database. A structured search strategy was designed to identify articles related to bariatric surgery with authors affiliated with Latin American countries. Inclusion and exclusion criteria were applied, followed by a descriptive and bibliometric analysis of the scientific production found. RESULTS: A total of 3553 documents published between 1991 and 2024 were included. There was an annual growth of 11%, with an average age of documents of 7.5 years. A concentration was observed in some countries, notably Brazil, Mexico, and Chile. Although scientific output increased, the average number of citations per article showed a downward trend since 2003. DISCUSSION: Despite the growth in scientific production, the quality and relevance of research is questioned, especially given the decrease in the impact received. It highlights the lack of meaningful regional collaboration, which could limit the sharing of knowledge and resources. Questions are raised about gaps in research capacity and the economic and development implications are discussed. CONCLUSIONS: This study provides valuable information to strengthen future research in bariatric surgery in Latin America. It highlights the importance of promoting regional and international collaboration and improving research training in countries with less participation. Clinical intervention strategies can benefit from better understanding research trends and adopting evidence-based practices in a more informed manner.
Assuntos
Cirurgia Bariátrica , Bibliometria , Cirurgia Bariátrica/estatística & dados numéricos , Humanos , Estudos Transversais , América Latina , Pesquisa Biomédica , Obesidade Mórbida/cirurgiaRESUMO
Up to now the lipid bilayers were rarely considered as targets in cancer therapy despite pronounced differences in lipid composition between plasma membranes of benign and malignant cells. In this study we demonstrate that the lipid bilayer of the plasma membrane is druggable and suitable for facilitating selective delivery of amphiphilic gemcitabine-squalene nanomedicines to cancer cells. Data from radioactive assays, fluorescent membrane probes and molecular dynamics simulations provide evidence of selective accumulation of gemcitabine-squalene in the plasma membranes with disrupted lipid asymmetry and its subsequent preferential uptake by malignant cells. This causes pronounced cytotoxicity on cancer cells in comparison to their benign counterparts originating from the same tissue.
Assuntos
Neoplasias , Pró-Fármacos , Gencitabina , Bicamadas Lipídicas/metabolismo , Esqualeno/metabolismo , Membrana Celular/metabolismo , Neoplasias/metabolismoRESUMO
Secoisolariciresinol diglucoside (SDG), the main phytoestrogenic lignan of Linum usitatissimum, is accumulated in the seed coat of flax during its development and pinoresinol-lariciresinol reductase (PLR) is a key enzyme in flax for its synthesis. The promoter of LuPLR1, a flax gene encoding a pinoresinol lariciresinol reductase, contains putative regulatory boxes related to transcription activation by abscisic acid (ABA). Gel mobility shift experiments evidenced an interaction of nuclear proteins extracted from immature flax seed coat with a putative cis-acting element involved in ABA response. As ABA regulates a number of physiological events during seed development and maturation we have investigated its involvement in the regulation of this lignan synthesis by different means. ABA and SDG accumulation time courses in the seed as well as LuPLR1 expression were first determined in natural conditions. These results showed that ABA timing and localization of accumulation in the flax seed coat could be correlated with the LuPLR1 gene expression and SDG biosynthesis. Experimental modulations of ABA levels were performed by exogenous application of ABA or fluridone, an inhibitor of ABA synthesis. When submitted to exogenous ABA, immature seeds synthesized 3-times more SDG, whereas synthesis of SDG was reduced in immature seeds treated with fluridone. Similarly, the expression of LuPLR1 gene in the seed coat was up-regulated by exogenous ABA and down-regulated when fluridone was applied. These results demonstrate that SDG biosynthesis in the flax seed coat is positively controlled by ABA through the transcriptional regulation of LuPLR1 gene.
Assuntos
Ácido Abscísico/metabolismo , Butileno Glicóis/metabolismo , Linho/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Lignanas/metabolismo , Oxirredutases/biossíntese , Linho/enzimologia , Linho/metabolismo , Furanos , Genes de Plantas , Lignanas/biossíntese , Oxirredutases/genética , Reguladores de Crescimento de Plantas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Sementes/enzimologia , Sementes/genética , Sementes/metabolismoRESUMO
Many signaling pathways, molecular and cellular actors which are critical for wound healing have been implicated in cancer metastasis. These two conditions are a complex succession of cellular biological events and accurate regulation of these events is essential. Apart from inflammation, macrophages-released ROS arise as major regulators of these processes. But, whatever the pathology concerned, oxidative stress is a complicated phenomenon to control and requires a finely tuned balance over the different stages and responding cells. This review provides an overview of the pivotal role of oxidative stress in both wound healing and metastasis, encompassing the contribution of macrophages. Indeed, macrophages are major ROS producers but also appear as their targets since ROS interfere with their differentiation and function. Elucidating ROS functions in wound healing and metastatic spread may allow the development of innovative therapeutic strategies involving redox modulators.
RESUMO
Maternal obesity is associated with a wide spectrum of labour disorders, including preterm birth. Leptin, a pro-inflammatory adipokine and a key factor of obesity, is suspected to play a major role in these disorders. OB-R, its receptor, is expressed on macrophages and myocytes, two cell types critical for labour onset. Macrophages secrete reactive oxygen species/pro-inflammatory cytokines, responsible for myometrial differentiation while myocytes control uterine contractions. In this study, we assessed the effect of leptin on myometrial contraction and differentiation using our validated co-culture model of human primary macrophages and myocytes. We demonstrated that leptin had a different effect on myocytes and macrophages depending on the dose. A low leptin concentration induced a tocolytic effect by preventing myocytes' contraction, differentiation, and macrophage-induced ROS production. Additionally, leptin led to an increase in HLA-G expression, suggesting that the tocolytic effect of leptin may be driven by HLA-G, a tolerogenic molecule. Finally, we observed that recombinant HLA-G also prevented LPS-induced ROS production by macrophages. Altogether, these data provide a putative molecular mechanism by which leptin may induce immune tolerance and therefore interfere with labour-associated mechanisms. Therefore, HLA-G represents a potential innovative therapeutic target in the pharmacological management of preterm labour.
Assuntos
Nascimento Prematuro , Tocolíticos , Feminino , Antígenos HLA-G , Humanos , Recém-Nascido , Leptina/farmacologia , Gravidez , Nascimento Prematuro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Contração UterinaRESUMO
BACKGROUND: We previously showed that supernatants of Lactobacillus biofilms induced an anti-inflammatory response by affecting the secretion of macrophage-derived cytokines, which was abrogated upon immunodepletion of the stress protein GroEL. METHODS: We purified GroEL from L. reuteri and analysed its anti-inflammatory properties in vitro in human macrophages isolated from buffy coats, ex vivo in explants from human biopsies and in vivo in a mouse model of DSS induced intestinal inflammation. As a control, we used GroEL purified (LPS-free) from E. coli. RESULTS: We found that L. reuteri GroEL (but not E. coli GroEL) inhibited pro-inflammatory M1-like macrophages markers, and favored M2-like markers. Consequently, L. reuteri GroEL inhibited pro-inflammatory cytokines (TNFα, IL-1ß, IFNγ) while favouring an anti-inflammatory secretome. In colon tissues from human biopsies, L. reuteri GroEL was also able to decrease markers of inflammation and apoptosis (caspase 3) induced by LPS. In mice, we found that rectal administration of L. reuteri GroEL (but not E. coli GroEL) inhibited all signs of haemorrhagic colitis induced by DSS including intestinal mucosa degradation, rectal bleeding and weight loss. It also decreased intestinal production of inflammatory cytokines (such as IFNγ) while increasing anti-inflammatory IL-10 and IL-13. These effects were suppressed when animals were immunodepleted in macrophages. From a mechanistic point of view, the effect of L. reuteri GroEL seemed to involve TLR4, since it was lost in TRL4-/- mice, and the activation of a non-canonical TLR4 pathway. CONCLUSIONS: L. reuteri GroEL, by affecting macrophage inflammatory features, deserves to be explored as an alternative to probiotics.
Assuntos
Chaperonina 60/farmacologia , Colo/efeitos dos fármacos , Inflamação/prevenção & controle , Lactobacillus/metabolismo , Animais , Chaperonina 60/uso terapêutico , Colo/fisiopatologia , Modelos Animais de Doenças , Inflamação/tratamento farmacológico , Limosilactobacillus reuteri/efeitos dos fármacos , Limosilactobacillus reuteri/metabolismo , Camundongos Endogâmicos BALB C , Estatísticas não ParamétricasRESUMO
In this work, we have explored natural unmodified low- and high-density lipoproteins (LDL and HDL, respectively) as selective delivery vectors in colorectal cancer therapy. We show in vitro in cultured cells and in vivo (NanoSPECT/CT) in the CT-26 mice colorectal cancer model that LDLs are mainly taken up by cancer cells, while HDLs are preferentially taken up by macrophages. We loaded LDLs with cisplatin and HDLs with the heat shock protein-70 inhibitor AC1LINNC, turning them into a pair of "Trojan horses" delivering drugs selectively to their target cells as demonstrated in vitro in human colorectal cancer cells and macrophages, and in vivo. Coupling of the drugs to lipoproteins and stability was assessed by mass spectometry and raman spectrometry analysis. Cisplatin vectorized in LDLs led to better tumor growth suppression with strongly reduced adverse effects such as renal or liver toxicity. AC1LINNC vectorized into HDLs induced a strong oxidative burst in macrophages and innate anticancer immune response. Cumulative antitumor effect was observed for both drug-loaded lipoproteins. Altogether, our data show that lipoproteins from patient blood can be used as natural nanocarriers allowing cell-specific targeting, paving the way toward more efficient, safer, and personalized use of chemotherapeutic and immunotherapeutic drugs in cancer.
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Sistemas de Liberação de Medicamentos/métodos , Lipoproteínas HDL/farmacologia , Lipoproteínas LDL/farmacologia , Animais , Linhagem Celular , Linhagem Celular Tumoral , Cisplatino/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Humanos , Lipoproteínas/sangue , Lipoproteínas/química , Lipoproteínas HDL/sangue , Lipoproteínas HDL/química , Lipoproteínas LDL/sangue , Lipoproteínas LDL/química , Macrófagos/efeitos dos fármacos , Camundongos , Análise Espectral Raman/métodosRESUMO
The LuPLR1 gene encodes a pinoresinol lariciresinol reductase responsible for the biosynthesis of (+)-secoisolariciresinol, a cancer chemopreventive lignan, highly accumulated in the seedcoat of flax (Linum usitatissimum L.). Abscisic acid (ABA) plays a key role in the regulation of LuPLR1 gene expression and lignan accumulation in both seeds and cell suspensions, which require two cis-acting elements (ABRE and MYB2) for this regulation. Ca2+ is a universal secondary messenger involved in a wide range of physiological processes including ABA signaling. Therefore, Ca2+ may be involved as a mediator of LuPLR1 gene expression and lignan biosynthesis regulation exerted by ABA. To test the potential implication of Ca2+ signaling, a pharmacological approach was conducted using both flax cell suspensions and maturing seed systems coupled with a ß-glucuronidase reporter gene experiment, RT-qPCR analysis, lignan quantification as well as Ca2+ fluorescence imaging. Exogenous ABA application results in an increase in the intracellular Ca2+ cytosolic concentration, originating mainly from the extracellular medium. Promoter-reporter deletion experiments suggest that the ABRE and MYB2 cis-acting elements of the LuPLR1 gene promoter functioned as Ca2+-sensitive sequences involved in the ABA-mediated regulation. The use of specific inhibitors pointed the crucial roles of the Ca2+ sensors calmodulin-like proteins and Ca2+-dependent protein kinases in this regulation. This regulation appeared conserved in the two different studied systems, i.e. cell suspensions and maturing seeds. A calmodulin-like, LuCML15b, identified from gene network analysis is proposed as a key player involved in this signal transduction since RNAi experiments provided direct evidences of this role. Taken together, these results provide new information on the regulation of plant defense and human health-promoting compounds, which could be used to optimize their production.
Assuntos
Ácido Abscísico/fisiologia , Cálcio/metabolismo , Calmodulina/metabolismo , Linho/metabolismo , Lignanas/biossíntese , Reguladores de Crescimento de Plantas/fisiologia , Proteínas de Plantas/metabolismo , Transdução de Sinais , Ácido Abscísico/metabolismo , Butileno Glicóis/metabolismo , Cromatografia Líquida de Alta Pressão , Regulação da Expressão Gênica de Plantas , Glucuronidase/metabolismo , Lignanas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteína Quinase C/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/fisiologia , TranscriptomaRESUMO
The transplantation of primordial germ cells (PGCs) is a valuable tool for gene-banking and reconstitution by means of a germline chimera. For this technology, studies regarding developmental stages and traceability of PGCs are necessary. The objective of this study was to develop a micromanipulation procedure for the future establishment of cryobanks of PGCs in migratory characins. Incubation temperatures were evaluated at 22 ° C, 26 ° C, and 30 ° C in order to synchronize developmental stages. The highest hatching rates and the lowest abnormality rate arose at 26° C, which was considered to be the best incubation temperature. Enzymatic removal of the chorion was determined to be best using 0.05% pronase, in which the embryos presented better survival rates. In order to visualize PGCs in vivo, artificial GFP-nos1 3'UTR mRNA was injected and the migration route was observed in vivo as PGCs were visualized firstly at the segmentation stage (6 to 13 somites). The number of GFP positive cells ranged from 8 to 20 per embryo (mean of 13.8; n = 5). After hatching, GFP-positive cells increased to 14 to 27 embryos (mean of 19.8; n = 5). Visualization of the GFP-positive cells was possible at 10 days post hatching, and at this stage, the cells were positioned in the yolk extension region. This is the first report on PGC visualization in vivo in Neotropical fish; the obtained data provide information on the identification and migration of PGCs. The information presented in this work brings new insights in gene banking in Neotropical species and subsequent reconstitution through a germinal germline chimera.
Assuntos
Movimento Celular , Caraciformes/embriologia , Córion , Embrião não Mamífero/citologia , Desenvolvimento Embrionário , Células Germinativas/citologia , Micromanipulação , Animais , Embrião não Mamífero/fisiologia , Células Germinativas/fisiologiaRESUMO
BACKGROUND AND OBJECTIVE: In order to assess whether Fok I vitamin D receptor gene (VDR) polymorphism is involved in the genetic susceptibility of type 1 diabetes, a case-control study was conducted and VDR genotypes were related to serum concentrations of 25(OH) vitamin D and cytokines transforming growth factor beta1 (TGF-beta1) and interferon gamma (INF-gamma). PATIENTS AND METHOD: 151 incident cases of type 1 diabetes and 182 non related healthy controls from Santiago were studied for VDR polymorphisms in peripheral blood DNA. Exon 2 (Fok I) segments were amplified by polimerase chain reaction and analyzed by means of restriction fragment length polymorphism to determine each corresponding genotype. Differences for allele, genotype and serological markers as 25(OH) vitamin D, TGF-beta1 and INF-gamma levels distribution between patients and controls were analyzed. RESULTS: Fok I polymorphism distribution analysis showed no differences between patients and controls. Among diabetics, higher levels of TGF-beta1 (median, 282.6 pg/ml; range, 131.8-3,031.4) were observed compared with healthy children (median, 232.2 pg/ml; range, 135.7-506.5) (p < 0.0038). Similar results were observed for INF-gamma concentrations (median, 121.1 pg/ml, and range, 5.3-228.8, in cases, and median, 89.6 pg/ml, and range, 10.9-117.2 in controls) (p < 0.0004). The diabetic carriers of the ff genotype showed low levels of 25(OH) vitamin D compared with the carriers of the F allele: mean (standard deviation), 23.1 (5.9) versus 27.9 (10.3) ng/ml (p < 0.03). A similar result was observed for TGF-beta1 concentrations in diabetic carriers of ff genotype and patients carriers of the F allele (298.5 versus 276.6; p < 0.05). CONCLUSIONS: Fok I polymorphism of VDR could have a marginal role in the immunologic disturbance in type 1 diabetes.
Assuntos
Diabetes Mellitus Tipo 1/genética , Interferon gama/sangue , Polimorfismo Genético , Receptores de Calcitriol/genética , Fator de Crescimento Transformador beta1/sangue , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Interpretação Estatística de Dados , Diabetes Mellitus Tipo 1/imunologia , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Lactente , Recém-Nascido , Polimorfismo de Fragmento de RestriçãoRESUMO
HSF1 is a transcription factor that plays a key role in circadian resetting by temperature. We have used zebrafish embryos to decipher the roles of zHsf1, heat and light on zper2 transcription in vivo. Our results show that heat shock (HS) stimulated zper2 expression in the dark but has no cumulative effect combined with light. After light exposition, zper2 expression was 2.7 fold increased threefold in the hsf1-morphants in comparison to control embryos. Our results show that zHsf1 plays a positive role in HS-driven expression of zper2 in the dark but seems to act as an attenuator in the presence light.
Assuntos
Ritmo Circadiano/fisiologia , Proteínas do Olho/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Proteínas Circadianas Period/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Proteínas Circadianas Period/genética , Peixe-Zebra/embriologiaRESUMO
Objetivos: realizar el estudio fitoquímico cualitativo para determinar la actividad antioxidante y toxicidad sobre Artemia salina de los extractos de las hojas de Justicia secunda Vahl, recolectada en Mérida, Venezuela. Metodología: el tamizaje fitoquímico de los extractos de las hojas de Justicia secunda Vahl. (Acanthaceae) se realizó a través de pruebas químicas específicas y permitió determinar la presencia de este-roles en el extracto hexanoico; esteroles y compuestos fenólicos en el diclorometanoico; alcaloides, esteroles y compuestos fenólicos en el extracto etanólico. La actividad antioxidante de los extractos de J. secunda fue evaluada usando el método de la capacidad secuestrante de radicales libres de 2,2-difenil-1-picrilhidrazilo (DPPH») mediante espectrofotometría UV-visible a una longitud de onda de 517 nm, con ácido ascórbico como control positivo (176 µg/rnL). Resultados: los extractos diclorometanoico y etanólico mostraron actividad antioxidante, con un porcentaje de inhibición superior a 50 a 4 mg/mL y a una concentración de 0,75 mg/mL un porcentaje de inhibición de 27,7 y 53,0; IC50 de 1,85 mg/mL y 0,69 mg/mL, respectivamente. En cuanto a la toxicidad sobre A. salina, del extracto etanólico mostró una DL50 entre 919,32 y 3781,9 ppm y es relativamente inocuo, según la clasificación CYTED. Conclusión: en general, los resultados obtenidos sugieren que los extractos de las hojas de J. secunda Vahl, podrían ser una alternativa en la formulación de fármacos, debido a su potencial como antioxidante y su baja toxicidad.
SUMMARY Aims: To carry out the qualitative phytochemical study to determine the antioxidant activity and toxicity on Artemia salina of the extracts of the leaves of Justicia secunda Vahl, collected in Mérida, Venezuela. Methodology: Phytochemical screening of extracts from the aerial parts of Justicia secunda Vahl. (Acanthaceae) was carried out through specific chemical tests that allowed the presence of sterols in the hexanoic extract to be determined; sterols and phenolic compounds in the dichloromethane and alkaloids, sterols and phenolic compounds in the ethanolic extract. The antioxidant activity of extracts from the aerial parts of J. secunda was evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPHâ¢) radical scavenging method, using spectrophotometry UV-Visible at a wavelength of 517 nm, with ascorbic acid as control (176 µg/mL). Results: The dichloromethane and ethanolic extracts showed anti-oxidant activity, with an inhibition percentage higher than 50 to 4 mg/mL and at a concentration of 0.75 mg / mL, percentage of 27.7 and 53.0; IC50 of 1.85 mg/mL and 0.69 mg/mL, respectively. Regarding toxicity on A. salina, the ethanolic extract showed an LD50 between 919.32 and 3781.9 ppm, it was relatively harmless, according to the CYTED classification. Conclusion: Overall, the results obtained suggest that the extracts of the aerial parts of J. secunda Vahl, could be an alternative for future drug formulation since it has potent antioxidant activity and low toxicity.
Objetivo: realizar o estudo fitoquímico qualitativo para determinar a atividade antioxidante e toxicidade sobre Artemia salina dos extratos das folhas de Justicia secunda Vahl, coletadas em Mérida, Venezuela. Metodologia: triagem fitoquímica de extratos das partes aéreas de Justicia secunda Vahl. (Acanthaceae) foi realizado por meio de testes químicos específicos e permitiu determinar a presença de esteróis no extrato hexanoico; esteróis e compostos fenólicos no diclorometano e alcalóides, esteróis e compostos fenólicos no extrato etanólico. A atividade antioxidante de extratos das partes aéreas de J. secunda foi avaliada pelo método de sequestro do radical 1,1-difenil-2-picrilhidrazil (DPPH»), por espectrofotometria UV-Visível no comprimento de onda de 517 nm, com ácido ascórbico como controle (176 µg/mL). Resultados: os extratos diclorometano e etanólico apresentaram atividade antioxidante, com percentual de inibição superior a 50 a 4 mg/mL e na concentração de 0,75 mg/ mL, percentagem de 27,7 e 53,0; IC50 de 1,85 mg/mL e 0,69 mg/mL, respectivamente. Em relação à toxicidade sobre A. salina, o extrato etanólico apresentou DL50 entre 919,32 e 3781,9 ppm, sendo relativamente inofensivo, segundo a classificação CYTED. Conclusão: de maneira geral, os resultados obtidos sugerem que os extratos das partes aéreas de J. secunda Vahl, podem ser uma alternativa para futura formulação de fármacos por apresentarem potente atividade antioxidante e baixa toxicidade.
RESUMO
Resumen Antecedentes: Clásicamente, la falla cardiaca se ha clasificado en dos grupos, según tengan fracción de eyección preservada o reducida; no obstante, en fecha reciente se ha añadido el grupo de fracción intermedia, y aún existe gran desconocimiento sobre sus características fisiopatológicas y clínicas. Objetivo: Caracterizar el grupo de pacientes con fracción intermedia en cuanto a sus variables sociodemográficas, clínicas y de tratamiento. Método: Se realizó un estudio descriptivo, retrospectivo, en el que se analizaron historias clínicas de pacientes con falla cardiaca hospitalizados por agudización en el periodo comprendido entre enero de 2015 y diciembre de 2017. Resultados: Se revisaron 1536 historias clínicas, de las cuales 864 cumplían los criterios de inclusión. El grupo con fracción intermedia correspondió a 83 (9.6%) pacientes, en quienes se encontró predominio del sexo femenino (53%) y una edad mediana de 77 años. La coronariopatía fue la etiología más frecuente (26.5%), mientras que la falta de adherencia a los medicamentos fue la causa principal de descompensación (14.5%). Los medicamentos más usados fueron los betabloqueadores y la furosemida, tanto al ingreso como al egreso. El grupo con mayor mortalidad fue el de fracción de eyección reducida (4.1%). La estancia hospitalaria, el ingreso y la estancia en la unidad de cuidados intensivos fueron similares en todos los grupos, independientemente de la fracción de eyección. Conclusiones: Los hallazgos son similares a los descritos en otras poblaciones internacionales y en algunas nacionales, y avalan la hipótesis de un fenotipo intermedio con un comportamiento etiológico semejante al de la fracción de eyección reducida.
Abstract Background: Classically, heart failure has been classified in two groups, depending on a preserved or reduced ejection fraction, but a mid-range ejection fraction group has been introduced recently, and there is still great ignorance about its physiopathological and clinical characteristics. Objective: To characterize this group of patients as for their sociodemographic, clinical and treatment variables. Method: We carried out a descriptive, retrospective study, by analyzing medical records from patients hospitalized with acute heart failure between January 2015 and December 2017. Results: We reviewed 1536 medical records of which 864 met the inclusion criteria. The mid-range ejection fraction group corresponded to 83 (9.6%) of patients, of which the majority were women (53%), with a median age of 77 years, coronary heart disease as the most frequent etiology (26.5%) and lack of adherence to medications as the main cause of decompensation (14.5%). The most frequently used drugs were betablockers and furosemide, both upon admission and discharge. Mortality was higher between patients with reduced ejection fraction (4.1%). Hospital stay, admission to and length of stay in an ICU, were similar between all groups regardless of ejection fraction. Conclusions: Our findings are similar to those described in previous international and national cohorts, and support the hypothesis of an intermediate phenotype with an etiology similar to that seen with a reduced ejection fraction.