RESUMO
MAIN CONCLUSION: Molecular mechanisms of biological rhythms provide opportunities to harness functional allelic diversity in core (and trait- or stress-responsive) oscillator networks to develop more climate-resilient and productive germplasm. The circadian clock senses light and temperature in day-night cycles to drive biological rhythms. The clock integrates endogenous signals and exogenous stimuli to coordinate diverse physiological processes. Advances in high-throughput non-invasive assays, use of forward- and inverse-genetic approaches, and powerful algorithms are allowing quantitation of variation and detection of genes associated with circadian dynamics. Circadian rhythms and phytohormone pathways in response to endogenous and exogenous cues have been well documented the model plant Arabidopsis. Novel allelic variation associated with circadian rhythms facilitates adaptation and range expansion, and may provide additional opportunity to tailor climate-resilient crops. The circadian phase and period can determine adaptation to environments, while the robustness in the circadian amplitude can enhance resilience to environmental changes. Circadian rhythms in plants are tightly controlled by multiple and interlocked transcriptional-translational feedback loops involving morning (CCA1, LHY), mid-day (PRR9, PRR7, PRR5), and evening (TOC1, ELF3, ELF4, LUX) genes that maintain the plant circadian clock ticking. Significant progress has been made to unravel the functions of circadian rhythms and clock genes that regulate traits, via interaction with phytohormones and trait-responsive genes, in diverse crops. Altered circadian rhythms and clock genes may contribute to hybrid vigor as shown in Arabidopsis, maize, and rice. Modifying circadian rhythms via transgenesis or genome-editing may provide additional opportunities to develop crops with better buffering capacity to environmental stresses. Models that involve clock geneâphytohormoneâtrait interactions can provide novel insights to orchestrate circadian rhythms and modulate clock genes to facilitate breeding of all season crops.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Relógios Circadianos , Relógios Circadianos/genética , Arabidopsis/genética , Reguladores de Crescimento de Plantas , Melhoramento Vegetal , Alelos , Produtos Agrícolas/genética , Fatores de Transcrição/genéticaRESUMO
In planta haploid induction (HI), which reduces the chromosome number in the progeny after fertilization, has garnered increasing attention for its significant potential in crop breeding and genetic research. Despite the identification of several natural and synthetic HI systems in different plant species, the molecular and cellular mechanisms underlying these HI systems remain largely unknown. This review synthesizes the current understanding of HI systems in plants (with a focus on genes and molecular mechanisms involved), including the molecular and cellular interactions which orchestrate the HI process. As most HI systems can function across taxonomic boundaries, we particularly discuss the evidence for conserved mechanisms underlying the process. These include mechanisms involved in preserving chromosomal integrity, centromere function, gamete communication and/or fusion, and maintenance of karyogamy. While significant discoveries and advances on haploid inducer systems have arisen over the past decades, we underscore gaps in understanding and deliberate on directions for further research for a more comprehensive understanding of in vivo HI processes in plants.
Assuntos
Melhoramento Vegetal , Plantas , Haploidia , Plantas/genética , CentrômeroRESUMO
Mushrooms are a nutritionally rich and sustainably-produced food with a growing global market. Agaricus bisporus accounts for 11% of the total world mushroom production and it is the dominant species cultivated in Europe. It faces threats from pathogens that cause important production losses, including the mycoparasite Lecanicillium fungicola, the causative agent of dry bubble disease. Through quantitative real-time polymerase chain reaction (qRT-PCR), we determine the impact of L. fungicola infection on the transcription patterns of A. bisporus genes involved in key cellular processes. Notably, genes related to cell division, fruiting body development, and apoptosis exhibit dynamic transcriptional changes in response to infection. Furthermore, A. bisporus infected with L. fungicola were found to accumulate increased levels of reactive oxygen species (ROS). Interestingly, the transcription levels of genes involved in the production and scavenging mechanisms of ROS were also increased, suggesting the involvement of changes to ROS homeostasis in response to L. fungicola infection. These findings identify potential links between enhanced cell proliferation, impaired fruiting body development, and ROS-mediated defence strategies during the A. bisporus (host)-L. fungicola (pathogen) interaction, and offer avenues for innovative disease control strategies and improved understanding of fungal pathogenesis.
Assuntos
Agaricus , Hypocreales , Espécies Reativas de Oxigênio , Agaricus/genética , Hypocreales/fisiologiaRESUMO
Light stimulates carotenoid synthesis in plants during photomorphogenesis through the expression of PHYTOENE SYNTHASE (PSY), a key gene in carotenoid biosynthesis. The orange carrot (Daucus carota) synthesizes and accumulates high amounts of carotenoids in the taproot that grows underground. Contrary to other organs, light impairs carrot taproot development and represses the expression of carotenogenic genes, such as DcPSY1 and DcPSY2, reducing carotenoid accumulation. By means of RNA sequencing, in a previous analysis, we observed that carrot PHYTOCHROME RAPIDLY REGULATED1 (DcPAR1) is more highly expressed in the underground grown taproot compared with those grown in light. PAR1 is a transcriptional cofactor with a negative role in shade avoidance syndrome regulation in Arabidopsis (Arabidopsis thaliana) through the dimerization with PHYTOCHROME-INTERACTING FACTORs (PIFs), allowing a moderate synthesis of carotenoids. Here, we show that overexpressing AtPAR1 in carrot increases carotenoid production in taproots grown underground as well as DcPSY1 expression. The high expression of AtPAR1 and DcPAR1 led us to hypothesize a functional role of DcPAR1 that was verified through in vivo binding to AtPIF7 and overexpression in Arabidopsis, where AtPSY expression and carotenoid accumulation increased together with a photomorphogenic phenotype. Finally, DcPAR1 antisense carrot lines presented a dramatic decrease in carotenoid levels and in relative expression of key carotenogenic genes as well as impaired taproot development. These results suggest that DcPAR1 is a key factor for secondary root development and carotenoid synthesis in carrot taproot grown underground.
Assuntos
Arabidopsis , Daucus carota , Fitocromo , Arabidopsis/genética , Arabidopsis/metabolismo , Carotenoides/metabolismo , Daucus carota/genética , Daucus carota/metabolismo , Regulação da Expressão Gênica de Plantas , Fitocromo/metabolismoRESUMO
Alcohol-induced pancreas damage remains as one of the main risk factors for pancreatitis development. This disorder is poorly understood, particularly the effect of acetaldehyde, the primary alcohol metabolite, in the endocrine pancreas. Hepatocyte growth factor (HGF) is a protective protein in many tissues, displaying antioxidant, antiapoptotic, and proliferative responses. In the present work, we were focused on characterizing the response induced by HGF and its protective mechanism in the RINm5F pancreatic cell line treated with ethanol and acetaldehyde. RINm5F cells were treated with ethanol or acetaldehyde for 12 h in the presence or not of HGF (50 ng/ml). Cells under HGF treatment decreased the content of reactive oxygen species and lipid peroxidation induced by both toxics, improving cell viability. This effect was correlated to an improvement in insulin expression impaired by ethanol and acetaldehyde. Using a specific inhibitor of Erk1/2 abrogated the effects elicited by the growth factor. In conclusion, the work provides mechanistic evidence of the HGF-induced-protective response to the alcohol-induced damage in the main cellular component of the endocrine pancreas.
Assuntos
Acetaldeído , Etanol , Acetaldeído/toxicidade , Acetaldeído/metabolismo , Linhagem Celular , Etanol/toxicidade , Fator de Crescimento de Hepatócito , Pâncreas/metabolismo , Sistema de Sinalização das MAP QuinasesRESUMO
Alternative splicing (AS) is a gene regulatory mechanism modulating gene expression in multiple ways. AS is prevalent in all eukaryotes including plants. AS generates two or more mRNAs from the precursor mRNA (pre-mRNA) to regulate transcriptome complexity and proteome diversity. Advances in next-generation sequencing, omics technology, bioinformatics tools, and computational methods provide new opportunities to quantify and visualize AS-based quantitative trait variation associated with plant growth, development, reproduction, and stress tolerance. Domestication, polyploidization, and environmental perturbation may evolve novel splicing variants associated with agronomically beneficial traits. To date, pre-mRNAs from many genes are spliced into multiple transcripts that cause phenotypic variation for complex traits, both in model plant Arabidopsis and field crops. Cataloguing and exploiting such variation may provide new paths to enhance climate resilience, resource-use efficiency, productivity, and nutritional quality of staple food crops. This review provides insights into AS variation alongside a gene expression analysis to select for novel phenotypic diversity for use in breeding programs. AS contributes to heterosis, enhances plant symbiosis (mycorrhiza and rhizobium), and provides a mechanistic link between the core clock genes and diverse environmental clues.
Assuntos
Processamento Alternativo , Arabidopsis , Melhoramento Vegetal , Splicing de RNA , Arabidopsis/genética , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Precursores de RNA/genéticaRESUMO
The latest studies on the epidemiology of diverse types of cancers have located in the scene the relevance of liver tumors, particularly hepatocellular carcinoma (HCC). HCC is a life-threatening malignancy triggered by chronic exposure to hepatitis B and C viruses, excessive alcohol intake, hepatic lipid droplet accumulation, and aflatoxins that lead to persistent liver damage. The occurrence of such etiological risk factors deeply marks the variability in the incidence of HCC worldwide reflected by geography, ethnicity, age, and lifestyle factors influenced by cultural aspects. New perspectives on the primary risk factors and their potential gene-environment interactions (GxE) have been well-addressed in some cancers; however, it continues to be a partially characterized issue in liver malignancies. In this review, the epidemiology of the risk factors for HCC are described enhancing the GxE interactions identified in Mexico, which could mark the risk of this liver malignancy among the population and the measures needed to revert them. Updated healthcare policies focusing on preventive care should be tailored based on the genetic and environmental risk factors, which may influence the effect of the etiological agents of HCC. Robust regional investigations related to epidemiological, clinical, and basic studies are warranted to understand this health problem complying with the rules of ethnic, genetic, environmental, and social diversity.
Assuntos
Carcinoma Hepatocelular , Hepatite B , Neoplasias Hepáticas , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/genética , Hepatite B/complicações , Humanos , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/genética , México/epidemiologia , Fatores de RiscoRESUMO
Growth differentiation factor 11 (GDF11) has been characterized as a key regulator of differentiation in cells that retain stemness features. Recently, it has been reported that GDF11 exerts tumor-suppressive properties in hepatocellular carcinoma cells, decreasing clonogenicity, proliferation, spheroid formation, and cellular function, all associated with a decrement in stemness features, resulting in mesenchymal to epithelial transition and loss of aggressiveness. The aim of the present work was to investigate the mechanism associated with the tumor-suppressive properties displayed by GDF11 in liver cancer cells. Hepatocellular carcinoma-derived cell lines were exposed to GDF11 (50 ng/ml), RNA-seq analysis in Huh7 cell line revealed that GDF11 exerted profound transcriptomic impact, which involved regulation of cholesterol metabolic process, steroid metabolic process as well as key signaling pathways, resembling endoplasmic reticulum-related functions. Cholesterol and triglycerides determination in Huh7 and Hep3B cells treated with GDF11 exhibited a significant decrement in the content of these lipids. The mTOR signaling pathway was downregulated, and this was associated with a reduction in key proteins involved in the mevalonate pathway. In addition, real-time metabolism assessed by Seahorse technology showed abridged glycolysis as well as glycolytic capacity, closely related to an impaired oxygen consumption rate and decrement in adenosine triphosphate production. Finally, transmission electron microscopy revealed mitochondrial abnormalities, such as cristae disarrangement, consistent with metabolic changes. Results provide evidence that GDF11 impairs cancer cell metabolism targeting lipid homeostasis, glycolysis, and mitochondria function and morphology.
Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Carcinoma Hepatocelular/metabolismo , Fatores de Diferenciação de Crescimento/metabolismo , Lipogênese , Neoplasias Hepáticas/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células , Regulação para Baixo , Glicólise , Humanos , Neoplasias Hepáticas/patologia , Consumo de Oxigênio , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismoRESUMO
The mechanism of damage of the biliary epithelium remains partially unexplored. However, recently many works have offered new evidence regarding the cholangiocytes' damage process, which is the main target in a broad spectrum of pathologies ranging from acute cholestasis, cholangiopathies to cholangiocarcinoma. This is encouraging since some works addressed this epithelium's relevance in health and disease until a few years ago. The biliary tree in the liver, comprised of cholangiocytes, is a pipeline for bile flow and regulates key hepatic processes such as proliferation, regeneration, immune response, and signaling. This review aimed to compile the most recent advances on the mechanisms of cholangiocellular damage during cholestasis, which, although it is present in many cholangiopathies, is not necessarily a common or conserved process in all of them, having a relevant role cAMP and PKA during obstructive cholestasis, as well as Ca2+-dependent PKC in functional cholestasis. Cholangiocellular damage could vary according to the type of cholestasis, the aggressor, or the bile ducts' location where it develops and what kind of damage can favor cholangiocellular carcinoma development.
Assuntos
Procedimentos Cirúrgicos do Sistema Biliar/efeitos adversos , Sistema Biliar/patologia , Colestase/patologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Animais , Sistema Biliar/metabolismo , Proliferação de Células , Colestase/metabolismo , Colestase/cirurgia , Humanos , Ligadura , Transdução de SinaisRESUMO
INTRODUCTION AND OBJECTIVES: It is well-known that signaling mediated by the hepatocyte growth factor (HGF) and its receptor c-Met in the liver is involved in the control of cellular redox status and oxidative stress, particularly through its ability to induce hepatoprotective gene expression by activating survival pathways in hepatocytes. It has been reported that HGF can regulate the expression of some members of the NADPH oxidase family in liver cells, particularly the catalytic subunits and p22phox. In the present work we were focused to characterize the mechanism of regulation of p22phox by HGF and its receptor c-Met in primary mouse hepatocytes as a key determinant for cellular redox regulation. MATERIALS AND METHODS: Primary mouse hepatocytes were treated with HGF (50 ng/mL) at different times. cyba expression (gene encoding p22phox) or protein content were addressed by real time RT-PCR, Western blot or immunofluorescence. Protein interactions were explored by immunoprecipitation and FRET analysis. RESULTS: Our results provided mechanistic information supporting the transcriptional repression of cyba induced by HGF in a mechanism dependent of NF-κB activity. We identified a post-translational regulation mechanism directed by p22phox degradation by proteasome 26S, and a second mechanism mediated by p22phox sequestration by c-Met in plasma membrane. CONCLUSION: Our data clearly show that HGF/c-Met exerts regulation of the NADPH oxidase by a wide-range of molecular mechanisms. NADPH oxidase-derived reactive oxygen species regulated by HGF/c-Met represents one of the main mechanisms of signal transduction elicited by this growth factor.
Assuntos
Grupo dos Citocromos b/fisiologia , Fator de Crescimento de Hepatócito/fisiologia , Hepatócitos/metabolismo , NADPH Oxidases/fisiologia , Proteínas Proto-Oncogênicas c-met/fisiologia , Transdução de Sinais/fisiologia , Animais , Técnicas de Cultura de Células , Hepatócitos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Biossíntese de Proteínas , Transcrição GênicaRESUMO
Tuberculosis (TB) is one of the deadliest infectious diseases in humankind history. Although, drug sensible TB is slowly decreasing, at present the rise of TB cases produced by multidrug-resistant (MDR) and extensively drug-resistant strains is a big challenge. Thus, looking for new therapeutic options against these MDR strains is mandatory. In the present work, we studied, in BALB/c mice infected with MDR strain, the therapeutic effect of supra-pharmacological doses of the conventional primary antibiotics rifampicin and isoniazid (administrated by gavage or intratracheal routes), in combination with recombinant human hepatocyte growth factor (HGF). This high dose of antibiotics administered for 3 months, overcome the resistant threshold of the MDR strain producing a significant reduction of pulmonary bacillary loads but induced liver damage, which was totally prevented by the administration of HGF. To address the long-term efficiency of this combined treatment, groups of animals after 1 month of treatment termination were immunosuppressed by glucocorticoid administration and, after 1 month, mice were euthanized, and the bacillary load was determined in lungs. In comparison with animals treated only with a high dose of antibiotics, animals that received the combined treatment showed significantly lower bacterial burdens. Thus, treatment of MDR-TB with very high doses of primary antibiotics particularly administrated by aerial route can produce a very good therapeutic effect, and its hepatic toxicity can be prevented by the administration of HGF, becoming in a new treatment modality for MDR-TB.
Assuntos
Antibióticos Antituberculose/toxicidade , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Fator de Crescimento de Hepatócito/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos , Animais , Quimioterapia Combinada , Humanos , Isoniazida/toxicidade , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis , Rifampina/toxicidadeRESUMO
N-(Aryloxy)imines, readily accessible by condensation/tautomerization of (pseudo)benzylic primary amines and 2,6-di-tert-butyl-1,4-benzoquinone, undergo efficient allylation to afford a wide range of homoallylic primary amines following hydrolytic workup. Deprotonation of N-(aryloxy)imines generates a delocalized 2-azaallyl anion-type nucleophile that engages in dearomative C-C bond-forming reactions with allylpalladium(II) electrophiles generated from allylic tert-butyl carbonates. This reactivity umpolung enables the formal α-allylation of (pseudo)benzylic primary amines. Mechanistic studies reveal that the apparent regioselectivity of the desired bond-forming event is a convergent process that is initiated by unselective allylation of N-(aryloxy)imines to give several regioisomeric species, which subsequently rearrange via stepwise [1,3]- or concerted [3,3]-sigmatropic shifts, ultimately converging to provide the desired regioisomer of the amine products.
Assuntos
Aminas , Iminas , Ânions , Catálise , PaládioRESUMO
INTRODUCTION AND OBJECTIVE: Non-alcoholic fatty liver disease remains as one of the main liver disorders worldwide. It is widely accepted that is the kind of lipid, rather than the amount deposited in the cells that determines cell damage. Cholesterol and saturated free fatty acids are deleterious lipids when accumulated but, in contrast, there are some valuable lipids that could counteract those with harmful properties. Much of this knowledge arises from studies using a single fatty acid, but the effects of a combination of fatty acids, as obtained by diet has been poorly addressed. In the present work, we were focused to figure out the cellular effect of two different mixes of fatty acids, one with high proportion of saturated fatty acids, and another one with high proportion of unsaturated fatty acids (Mediterranean-like) in a cellular model of steatosis. MATERIAL AND METHODS: Primary mouse hepatocytes from animals fed with a western diet (high fat and carbohydrates diet), were treated with both mixes of fatty acids for 24â¯h. RESULTS: Our data clearly show that only the high unsaturated fatty acid mix induced a decrease in triglycerides (47.5%) and cholesterol (59%) content in steatotic hepatocytes mediating cellular protection associated to the decrement of ROS and oxidative damage. The mixture of high saturated fatty acids exhibited no effects, preserving high levels of cholesterol and triglycerides and oxidative damage. In conclusion, our results show that Mediterranean-like mix of fatty acids exerts cellular protection in steatosis by decreasing triglycerides, cholesterol, ROS content and oxidative damage.
Assuntos
Dieta Mediterrânea , Dieta Ocidental , Ácidos Graxos Insaturados/farmacologia , Hepatócitos/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Animais , Antígenos de Neoplasias/efeitos dos fármacos , Células Cultivadas , Colesterol/metabolismo , Modelos Animais de Doenças , Hepatócitos/metabolismo , Hepatócitos/patologia , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Endogâmicos BALB C , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Estresse Oxidativo/efeitos dos fármacos , Fosfolipases A1/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Triglicerídeos/metabolismoRESUMO
Non-alcoholic fatty liver disease (NAFLD) encompasses a broad spectrum of histopathological changes ranging from non-inflammatory intracellular fat deposition to non-alcoholic steatohepatitis (NASH), which may progress into hepatic fibrosis, cirrhosis, or hepatocellular carcinoma. Recent data suggest that impaired hepatic cholesterol homeostasis and its accumulation are relevant to the pathogenesis of NAFLD/NASH. Despite a vital physiological function of cholesterol, mitochondrial dysfunction is an important consequence of dietary-induced hypercholesterolemia and was, subsequently, linked to many pathophysiological conditions. The aim in the current study was to evaluate the morphological and molecular changes of cholesterol overload in mouse liver and particularly, in mitochondria, induced by a high-cholesterol (HC) diet for one month. Histopathological studies revealed microvesicular hepatic steatosis and significantly elevated levels of liver cholesterol and triglycerides leading to impaired liver synthesis. Further, high levels of oxidative stress could be determined in liver tissue as well as primary hepatocyte culture. Transcriptomic changes induced by the HC diet involved disruption in key pathways related to cell death and oxidative stress as well as upregulation of genes related to glutathione homeostasis. Impaired liver function could be associated with a decrease in mitochondrial membrane potential and ATP content and significant alterations in mitochondrial dynamics. We demonstrate that cholesterol overload in the liver leads to mitochondrial changes which may render damaged hepatocytes proliferative and resistant to cell death whereby perpetuating liver damage.
Assuntos
Apoptose , Colesterol na Dieta , Dieta Hiperlipídica , Hepatócitos/patologia , Fígado/patologia , Mitocôndrias Hepáticas/patologia , Dinâmica Mitocondrial , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Apoptose/genética , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Fígado/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/metabolismo , Dinâmica Mitocondrial/genética , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Estresse Oxidativo , Fatores de Tempo , TranscriptomaRESUMO
Linoleic acid (LA) is an essential and omega-6 polyunsaturated fatty acid that mediates a variety of biological processes, including migration and invasion in breast cancer cells. Phospholipase D (PLD) catalyses the hydrolysis of phosphatidylcholine to produce phosphatidic acid and choline. Increases of expression and activity of PLD are reported in several human cancers, including gastric, colorectal, renal, stomach, lung and breast. In this article, we demonstrate that LA induces an increase of PLD activity in MDA-MB-231 breast cancer cells. Particularly, PLD1 and/or PLD2 mediate migration and invasion induced by LA. Moreover, LA induces increases in number and size of spheroids via PLD activity. FFAR1 also mediates migration and invasion, whereas PLD activation induced by LA requires the activities of FFAR1, FFAR4 and EGFR in MDA-MB-231 cells. In summary, PLD plays a pivotal role in migration and invasion induced by LA in MDA-MB-231 breast cancer cells.
Assuntos
Neoplasias da Mama/enzimologia , Movimento Celular/efeitos dos fármacos , Ácido Linoleico/farmacologia , Proteínas de Neoplasias/metabolismo , Fosfolipase D/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Células MCF-7 , Invasividade NeoplásicaRESUMO
Acute pancreatitis is a multifactorial disease associated with profound changes of the pancreas induced by release of digestive enzymes that lead to increase in proinflammatory cytokine production, excessive tissue necrosis, edema, and bleeding. Elevated levels of hepatocyte growth factor (HGF) and its receptor c-Met have been observed in different chronic and acute pancreatic diseases including experimental models of acute pancreatitis. In the present study, we investigated the protective effects induced by the recombinant human HGF in a mouse model of cerulein-induced acute pancreatitis. Pancreatitis was induced by 8 hourly administrations of supramaximal cerulein injections (50 µg/kg, ip). HGF treatment (20 µg/kg, iv), significantly attenuated lipase content and amylase activity in serum as well as the degree inflammation and edema overall leading to less severe histologic changes such as necrosis, induced by cerulein. Protective effects of HGF were associated with activation of pro-survival pathways such as Akt, Erk1/2, and Nrf2 and increase in executor survival-related proteins and decrease in pro-apoptotic proteins. In addition, ROS content and lipid peroxidation were diminished, and glutathione synthesis increased in pancreas. Systemic protection was observed by lung histology. In conclusion, our data indicate that HGF exerts an Nrf2 and glutathione-mediated protective effect on acute pancreatitis reflected by a reduction in inflammation, edema, and oxidative stress.
Assuntos
Fator de Crescimento de Hepatócito/uso terapêutico , Pancreatite/tratamento farmacológico , Substâncias Protetoras/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Ceruletídeo , Modelos Animais de Doenças , Glutationa/biossíntese , Fator de Crescimento de Hepatócito/sangue , Fator de Crescimento de Hepatócito/farmacologia , Humanos , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Pancreatite/patologia , Substâncias Protetoras/farmacologia , Proteínas Proto-Oncogênicas c-met/metabolismo , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Análise de SobrevidaRESUMO
INTRODUCTION AND AIM: Obesity is a worldwide epidemic problem, described as a risk factor for hepatic diseases, such as non-alcoholic fatty liver disease and other pathologies related to development of cholesterol crystals and cholesterol gallbladder stones. It has been reported that cholesterol overload may cause hepatic damage; however, little is known about the effects of an acute hypercholesterolemic diet on the gallbladder. The aim of this manuscript was to evaluate the impact of a cholesterol-rich diet on the gallbladder. MATERIAL AND METHODS: The study included ten eight-week-old C57BL6 male mice, which were divided into two study groups and fed different diets for 48 h: a hypercholesterolemic diet and a balanced Chow diet. After 48 h, the mice were analyzed by US with a Siemens Acuson Antares equipment. Mice were subsequently sacrificed to carry out a cholesterol analysis with a Refloton System (Roche), a crystal analysis with a Carl Zeiss microscope with polarized light, and a histological analysis with Hematoxylin-eosin staining. RESULTS: The hypercholesterolemic diet induced an increase in gallbladder size and total cholesterol content in the bile, along with important histological changes. CONCLUSION: Cholesterol overloads not only trigger hepatic damage, but also affect the gallbladder significantly.
Assuntos
Colesterol na Dieta , Vesícula Biliar , Cálculos Biliares/etiologia , Hipercolesterolemia/etiologia , Ultrassonografia , Animais , Bile/metabolismo , Colesterol na Dieta/sangue , Cristalização , Modelos Animais de Doenças , Fígado Gorduroso/etiologia , Vesícula Biliar/diagnóstico por imagem , Vesícula Biliar/metabolismo , Vesícula Biliar/patologia , Cálculos Biliares/sangue , Cálculos Biliares/diagnóstico por imagem , Cálculos Biliares/patologia , Hipercolesterolemia/sangue , Masculino , Camundongos Endogâmicos C57BL , Microscopia de Polarização , Fatores de TempoRESUMO
French intervention in Mexico (1861-1867) is particularly full of episodes of patriotic heroism in terms of military, politic and, even, religious affairs, however this history is also rich in episodes related to diseases and the evolution of Mexican scientific medicine practice, epidemics such as typhus (nowadays knows as rickettsiosis), yellow fever, or cholera. Principally, this context outlined the Mexican history and influenced the course of the nation. The epidemics served as fertile land for the development of medicine science leading by prominent physicians, particularly by doctor Miguel Francisco Jiménez.
El periodo comprendido entre 1861 y 1867, marcado por la ocupación extranjera, particularmente por Francia, es sin lugar a dudas rico en gestas de patriotismo sin igual en la historia de México por la coyuntura política, militar e incluso religiosa del periodo en cuestión; sin embargo, poco se ha abordado de manera concreta el estado que guardaban la salud y la ciencia médica en dicho periodo, lleno de episodios sumamente interesantes en cuanto a epidemias como el tifo, la fiebre amarilla o el cólera, sobre todo cuando estas enfermedades afectaron y marcaron el rumbo de la historia nacional, a la par con el desarrollo de la naciente medicina científica mexicana encabezada por varios médicos, en especial por el Dr. Miguel Francisco Jiménez.
Assuntos
História da Medicina , Tifo Epidêmico Transmitido por Piolhos/história , Febre Amarela/história , França , História do Século XIX , MéxicoRESUMO
The pentacyclic alkaloid calothrixin B (1) has been synthesized in 5 steps from murrayaquinone A (9). The key step involved the union of boryl aniline 31 with brominated murrayaquinone A (26). In this transformation, alkylquinone 26 undergoes tautomerization to a quinone methide, which is intercepted by boryl aniline 31 to forge a new C-N bond. An intramolecular Suzuki coupling, followed by dehydrogenative aromatization, completed the synthesis of calothrixin B. Subsequent N-oxidation of calothrixin B delivered calothrixin A. The successful synthesis of these alkaloids and the challenges that led to the development of the final synthesis plan are reported herein.
Assuntos
Benzoquinonas/química , Alcaloides Indólicos/síntese química , Aminação , Alcaloides Indólicos/química , Estrutura MolecularRESUMO
BACKGROUND: Currently, two pathogenic pathways describe the role of obesity in osteoarthritis (OA); one through biomechanical stress, and the other by the contribution of systemic inflammation. The aim of this study was to evaluate the effect of free fatty acids (FFA) in human chondrocytes (HC) expression of proinflammatory factors and reactive oxygen species (ROS). METHODS: HC were exposed to two different concentrations of FFA in order to evaluate the secretion of adipokines through cytokines immunoassays panel, quantify the protein secretion of FFA-treated chondrocytes, and fluorescent cytometry assays were performed to evaluate the reactive oxygen species (ROS) production. RESULTS: HC injury was observed at 48 h of treatment with FFA. In the FFA-treated HC the production of reactive oxygen species such as superoxide radical, hydrogen peroxide, and the reactive nitrogen species increased significantly in a at the two-dose tested (250 and 500 µM). In addition, we found an increase in the cytokine secretion of IL-6 and chemokine IL-8 in FFA-treated HC in comparison to the untreated HC. CONCLUSION: In our in vitro model of HC, a hyperlipidemia microenvironment induces an oxidative stress state that enhances the inflammatory process mediated by adipokines secretion in HC.