RESUMEN
New binuclear copper(II) [Cu(II)] tetraligand complexes (six examples) with sulfanylpyrazole ligands were synthesized. Electron spin resonance (ESR) studies have shown that in solution the complexes are transformed to the mononuclear one. Fungicidal properties against Candida albicans were found for the Cu complexes with benzyl and phenyl substituents. An in vitro evaluation of the cytotoxic properties of Cu chelates against HEK293, Jurkat, MCF-7, and THP-1 cells identified the Cu complex with the cyclohexylsulfanyl substituent in the pyrazole core as the lead compound, whereas the Cu complex without a sulfur atom in the pyrazole ligand had virtually no cytotoxic or fungicidal activity. The lead Cu(II) complex was more active than cisplatin. Effect of the S-containing Cu complex on apoptosis and cell cycle distribution has been investigated as well.
Asunto(s)
Antifúngicos , Candida albicans , Complejos de Coordinación , Cobre , Pirazoles , Cobre/química , Cobre/farmacología , Humanos , Pirazoles/química , Pirazoles/farmacología , Pirazoles/síntesis química , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Ligandos , Candida albicans/efectos de los fármacos , Antifúngicos/farmacología , Antifúngicos/química , Antifúngicos/síntesis química , Cristalografía por Rayos X , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Apoptosis/efectos de los fármacos , Citostáticos/farmacología , Citostáticos/química , Citostáticos/síntesis químicaRESUMEN
The incidence of hypertension with diabetes mellitus (DM) as a co-morbid condition is on the rise worldwide. In 2000, an estimated 972 million adults had hypertension, which is predicted to grow to 1.56 billion by 2025. Hypertension often leads to diabetes mellitus that strongly puts the patients at an increased risk of cardiovascular, kidney, and/or atherosclerotic diseases. Hypertension has been identified as a major risk factor for the development of diabetes; patients with hypertension are at two-to-three-fold higher risk of developing diabetes than patients with normal blood pressure (BP). Causes for the increase in hypertension and diabetes are not well understood, environmental factors (e.g., exposure to environmental toxicants like heavy metals, organic solvents, pesticides, alcohol, and urban lifestyle) have been postulated as one of the reasons contributing to hypertension and cardiovascular diseases (CVD). The mechanism of action(s) of these toxicants in developing hypertension and CVDs is not well defined. Research studies have linked hypertension with the chronic consumption of alcohol and exposure to metals like lead, mercury, and arsenic have also been linked to hypertension and CVD. Workers chronically exposed to styrene have a higher incidence of CVD. Recent studies have demonstrated that exposure to particulate matter (PM) in diesel exhaust and urban air contributes to increased CVD and mortality. In this review, we have imparted the role of environmental toxicants such as heavy metals, organic pollutants, PM, alcohol, and some drugs in hypertension and CVD along with possible mechanisms and limitations in extrapolating animal data to humans.
RESUMEN
BACKGROUND: The COVID-19 pandemic has placed exceptional demand on Intensive Care Units, necessitating the critical care transfer of patients on a regional and national scale. Performing these transfers required specialist expertise and involved moving patients over significant distances. Air Ambulance Kent Surrey Sussex created a designated critical care transfer team and was one of the first civilian air ambulances in the United Kingdom to move ventilated COVID-19 patients by air. We describe the practical set up of such a service and the key lessons learned from the first 50 transfers. METHODS: Retrospective review of air critical care transfer service set up and case review of first 50 transfers. RESULTS: We describe key elements of the critical care transfer service, including coordination and activation; case interrogation; workforce; training; equipment; aircraft modifications; human factors and clinical governance. A total of 50 missions are described between 18 December 2020 and 1 February 2021. 94% of the transfer missions were conducted by road. The mean age of these patients was 58 years (29-83). 30 (60%) were male and 20 (40%) were female. The mean total mission cycle (time of referral until the time team declared free at receiving hospital) was 264 min (range 149-440 min). The mean time spent at the referring hospital prior to leaving for the receiving unit was 72 min (31-158). The mean transfer transit time between referring and receiving units was 72 min (9-182). CONCLUSION: Critically ill COVID-19 patients have highly complex medical needs during transport. Critical care transfer of COVID-19-positive patients by civilian HEMS services, including air transfer, can be achieved safely with specific planning, protocols and precautions. Regional planning of COVID-19 critical care transfers is required to optimise the time available of critical care transfer teams.
Asunto(s)
Ambulancias Aéreas , COVID-19 , Servicios Médicos de Urgencia , Adulto , Anciano , Anciano de 80 o más Años , Aeronaves , Cuidados Críticos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Estudios Retrospectivos , SARS-CoV-2RESUMEN
Epigenetic regulation involves reversible changes in histones and DNA modifications that can be inherited without any changes in the DNA sequence. Dysregulation of normal epigenetic processes can lead to aberrant gene expression as observed in many diseases, notably cancer. Recent insights into the mechanisms of DNA methylation, histone modifications, and non-coding RNAs involved in altered gene expression profiles of tumor cells have caused a paradigm shift in the diagnostic and therapeutic approaches towards cancer. There has been a surge in search for compounds that could modulate the altered epigenetic landscape of tumor cells, and to exploit their therapeutic potential against cancers. Flavonoids are naturally occurring phenol compounds which are abundantly found among phytochemicals and have potentials to modulate epigenetic processes. Knowledge of the precise flavonoid-mediated epigenetic alterations is needed for the development of epigenetics drugs and combinatorial therapeutic approaches against cancers. This review is aimed to comprehensively explore the epigenetic modulations of flavonoids and their anti-tumor activities.
RESUMEN
The overuse of cisplatin (>50 mg/m2) is limited to nephrotoxicity, ototoxicity, gastrotoxicity, myelosuppression, and allergic reactions. The objective of this study was to investigate the nephroprotective effects of Daucus carota and Eclipta prostrata extracts on cisplatin-induced nephrotoxicity in Wistar albino rats. The study involved male Wistar albino rats of 8 weeks weighing 220-270 g. A single injection of 5 mg/kg was injected into the rats for nephrotoxicity. Rats were divided into four groups based on dose conentrations. Blood and urine samples of rats were collected on the 0, 7th, 14th, and 21st days for nephrological analysis. The results showed that Cis + DC/Cis + EP (600 mg/kg) significantly (p < 0.001) increased the body weight and reduced the kidney weight of cisplatin-induced nephrotoxicity in rats (p < 0.001) as compared to Cis group. The results showed that 600 mg/kg administration of Cis + DC/Cis +EP successfully (p < 0.005) improved the urine and plasmin creatinine, Na, and K level compared to the Cis group. Histopathological results confirmed that Cis + EP/Cis + DC effectively improved the renal abnormalities. It is concluded that the co-administration of Cis + EP extract showed exceptional nephroprotective effects at a dose rate of 600 mg/kg.
Asunto(s)
Cisplatino/efectos adversos , Daucus carota/química , Eclipta/química , Enfermedades Renales/inducido químicamente , Enfermedades Renales/tratamiento farmacológico , Sustancias Protectoras/uso terapéutico , Animales , Peso Corporal/efectos de los fármacos , Creatinina/sangre , Riñón/efectos de los fármacos , Riñón/patología , Enfermedades Renales/sangre , Enfermedades Renales/orina , Masculino , Tamaño de los Órganos/efectos de los fármacos , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Potasio/orina , Sustancias Protectoras/farmacología , Ratas Wistar , Sodio/orina , Micción/efectos de los fármacosRESUMEN
BACKGROUND: Breast cancer (BC), the second most common cause of cancer-related deaths, remains a significant threat to the health and wellness of women worldwide. The tumor microenvironment (TME), comprising cellular components, such as cancer-associated fibroblasts (CAFs), immune cells, endothelial cells and adipocytes, and noncellular components such as extracellular matrix (ECM), has been recognized as a critical contributor to the development and progression of BC. The interplay between TME components and cancer cells promotes phenotypic heterogeneity, cell plasticity and cancer cell stemness that impart tumor dormancy, enhanced invasion and metastasis, and the development of therapeutic resistance. While most previous studies have focused on targeting cancer cells with a dismal prognosis, novel therapies targeting stromal components are currently being evaluated in preclinical and clinical studies, and are already showing improved efficacies. As such, they may offer better means to eliminate the disease effectively. CONCLUSIONS: In this review, we focus on the evolving concept of the TME as a key player regulating tumor growth, metastasis, stemness, and the development of therapeutic resistance. Despite significant advances over the last decade, several clinical trials focusing on the TME have failed to demonstrate promising effectiveness in cancer patients. To expedite clinical efficacy of TME-directed therapies, a deeper understanding of the TME is of utmost importance. Secondly, the efficacy of TME-directed therapies when used alone or in combination with chemo- or radiotherapy, and the tumor stage needs to be studied. Likewise, identifying molecular signatures and biomarkers indicating the type of TME will help in determining precise TME-directed therapies.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Resistencia a Antineoplásicos , Células Madre Neoplásicas/patología , Microambiente Tumoral , Animales , Fibroblastos Asociados al Cáncer/patología , Femenino , Humanos , Terapia Molecular DirigidaRESUMEN
Maintenance of genomic integrity is critical for the perpetuation of all forms of life including humans. Living organisms are constantly exposed to stress from internal metabolic processes and external environmental sources causing damage to the DNA, thereby promoting genomic instability. To counter the deleterious effects of genomic instability, organisms have evolved general and specific DNA damage repair (DDR) pathways that act either independently or mutually to repair the DNA damage. The mechanisms by which various DNA repair pathways are activated have been fairly investigated in model organisms including bacteria, fungi, and mammals; however, very little is known regarding how plants sense and repair DNA damage. Plants being sessile are innately exposed to a wide range of DNA-damaging agents both from biotic and abiotic sources such as ultraviolet rays or metabolic by-products. To escape their harmful effects, plants also harbor highly conserved DDR pathways that share several components with the DDR machinery of other organisms. Maintenance of genomic integrity is key for plant survival due to lack of reserve germline as the derivation of the new plant occurs from the meristem. Untowardly, the accumulation of mutations in the meristem will result in a wide range of genetic abnormalities in new plants affecting plant growth development and crop yield. In this review, we will discuss various DNA repair pathways in plants and describe how the deficiency of each repair pathway affects plant growth and development.
RESUMEN
Head and neck squamous cell carcinomas (HNSCCs) are a group of heterogeneous aggressive tumors affecting more than half a million patients worldwide annually. While the tobacco- and alcohol-associated HNSCC tumors are declining, human papillomavirus (HPV)-induced tumors are on rise. Despite recent advances in multimodality therapeutic interventions including surgery in combination with chemoradiation therapy (CRT), the overall 5-year survival has not improved more than 50%. The underlying reasons for this dismal prognosis is the intrinsic or acquired resistance to CRT. While previous studies were focused to target tumor cells, recent findings have implicated the involvement of tumor microenvironment (TME) on tumor progression and response to therapy. HNSCC TME includes cancer-associated fibroblasts (CAFs), endothelial cells, immune cells, endocrine cells, and the extracellular matrix (ECM) proteins including collagen and fibronectin. Understanding the crosstalk between TME and cancer cells is important to formulate more effective novel therapies and to overcome resistance mechanisms. Here, we summarized the current literature on recent advances on HNSCC TME with special emphasis on novel cell-cell interactions and therapies currently under development.
Asunto(s)
Neoplasias de Cabeza y Cuello , Infecciones por Papillomavirus , Células Endoteliales , Neoplasias de Cabeza y Cuello/terapia , Humanos , Papillomaviridae , Carcinoma de Células Escamosas de Cabeza y Cuello/terapia , Microambiente TumoralRESUMEN
FACT (facilitates chromatin transcription) is a protein complex that allows RNA polymerase II (RNAPII) to overcome the nucleosome-induced barrier to transcription. While abundant in undifferentiated cells and many cancers, FACT is not abundant or is absent in most tissues. Therefore, we screened for additional proteins that might replace FACT upon differentiation. We identified two proteins, lens epithelium-derived growth factor (LEDGF) and hepatoma-derived growth factor 2 (HDGF2), each containing two high mobility group A (HMGA)-like AT-hooks and a methyl-lysine reading Pro-Trp-Trp-Pro (PWWP) domain that binds to H3K36me2 and H3K36me3.LEDGF and HDGF2 colocalize with H3K36me2/3 at genomic regions containing active genes. In myoblasts, LEDGF and HDGF2 are enriched on most active genes. Upon differentiation to myotubes, LEDGF levels decrease, while HDGF2 levels are maintained. Moreover, HDGF2 is required for their proper expression. HDGF2 knockout myoblasts exhibit an accumulation of paused RNAPII within the transcribed region of many HDGF2 target genes, indicating a defect in early elongation.
Asunto(s)
Diferenciación Celular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Nucleosomas/metabolismo , Transcripción Genética , Animales , Regulación de la Expresión Génica , Células HeLa , Humanos , Ratones , Unión Proteica , Células Madre/metabolismoRESUMEN
Development of multidrug resistance among pathogens has become a global problem for chemotherapy of bacterial infections. Extended-spectrum ß-lactamase- (ESßL-) producing enteric bacteria and methicillin-resistant Staphylococcus aureus (MRSA) are the two major groups of problematic MDR bacteria that have evolved rapidly in the recent past. In this study, the aqueous extract of Murraya koenigii leaves was used for synthesis of silver nanoparticles. The synthesized MK-AgNPs were characterized using UV-vis spectroscopy, FTIR, XRD, SEM, and TEM, and their antibacterial potential was evaluated on multiple ESßL-producing enteric bacteria and MRSA. The nanoparticles were predominantly found to be spheroidal with particle size distribution in the range of 5-20 nm. There was 60.86% silver content in MK-AgNPs. Evaluation of antibacterial activity by the disc-diffusion assay revealed that MK-AgNPs effectively inhibited the growth of test pathogens with varying sized zones of inhibition. The MICs of MK-AgNPs against both MRSA and methicillin-sensitive S. aureus (MSSA) strains were 32 µg/ml, while for ESßL-producing E. coli, it ranged from 32 to 64 µg/ml. The control strain of E. coli (ECS) was relatively more sensitive with an MIC of 16 µg/ml. The MBCs were in accordance with the respective MICs. Analysis of growth kinetics revealed that the growth of all tested S. aureus strains was inhibited (â¼90%) in presence of 32 µg/ml of MK-AgNPs. The sensitive strain of E. coli (ECS) showed least resistance to MK-AgNPs with >81% inhibition at 16 µg/ml. The present investigation revealed an encouraging result on in vitro efficacy of green synthesized MK-AgNPs and needed further in vivo assessment for its therapeutic efficacy against MDR bacteria.
RESUMEN
Cancer and the associated secondary bacterial infections are leading cause of mortality, due to the paucity of effective drugs. Here, we have synthesized silver nanoparticles (AgNPs) from organic resource and confirmed their anti-cancer and anti-microbial potentials. Microwave irradiation method was employed to synthesize AgNPs using Pandanus odorifer leaf extract. Anti-cancer potential of AgNPs was evaluated by scratch assay on the monolayer of rat basophilic leukemia (RBL) cells, indicating that the synthesized AgNPs inhibit the migration of RBL cells. The synthesized AgNPs showed MIC value of 4-16 µg/mL against both Gram +ve and Gram -ve bacterial strains, exhibiting the anti-microbial potential. Biofilm inhibition was recorded at sub-MIC values against Gram +ve and Gram -ve bacterial strains. Violacein and alginate productions were reduced by 89.6 and 75.6%, respectively at 4 and 8 µg/mL of AgNPs, suggesting anti-quorum sensing activity. Exopolysaccharide production was decreased by 61-79 and 84% for Gram -ve and Gram +ve pathogens respectively. Flagellar driven swarming mobility was also reduced significantly. Furthermore, In vivo study confirmed their tolerability in mice, indicating their clinical perspective. Collective, we claim that the synthesized AgNPs have anti-metastasis as well as anti-microbial activities. Hence, this can be further tested for therapeutic options to treat cancer and secondary bacterial infections.
RESUMEN
BACKGROUND: Organ donation in the United Arab Emirates (UAE) was restricted until recently to living donation. This survey was conducted to explore the public knowledge, belief, and attitude regarding donation during life and after death. METHODOLOGY: A 31-item survey was distributed among 900 participants (UAE residents) of whom 495 completed the forms and were considered for further analysis. RESULTS: Among the participants, 293 (59.2%) were women and 202 (40.1%) were men. With 8 items as the highest possible score, the mean score of knowledge was 4.42 (SD = 1.54) and 436 (88%) of the participants knew about a brain-dead condition. However, their awareness on organ donation and transplantation legislation in the UAE was not consistent, and less than 198 (40%) had correct knowledge in this regard. Religious belief regarding organ donation was scored at 80 and the mean of the beliefs score obtained was 56.56 (SD = 6.39). Together, 369 (74.6%) of the participants had positive religious sentiments regarding the issue. Participants' attitude toward organ donation and transplantation was scored at 14.7 out of 20 possible score (SD = 2.46) with 396 (80%) acknowledging the fact that organ donation and transplantation prolongs and improves recipient's quality of life. LIMITATIONS: The small number of respondents (n = 495) in the survey was a limitation of the study. CONCLUSIONS: The population of the UAE was moderately well informed and motivated about organ donation and transplantation. Although a knowledge gap about the current legislation prevailed, the majority of the participants were knowledgeable, they nurtured positive beliefs, and had compassionate attitude regarding lawful organ transplantation.
Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Donantes de Tejidos/psicología , Obtención de Tejidos y Órganos , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Religión , Encuestas y Cuestionarios , Donantes de Tejidos/provisión & distribución , Emiratos Árabes UnidosRESUMEN
Rheumatoid arthritis (RA) is a chronic, inflammatory, systemic autoimmune disease, affecting the joints with varying severity among patients. The risk factors include age, gender, genetics, and environmental exposure (cigarette smoking, air pollutants, and occupational). Many complications can follow, such as permanent joint damage requiring arthroplasty, rheumatoid vasculitis, and Felty syndrome requiring splenectomy if it remains unaddressed. As there is no cure for RA, the treatment goals are to reduce the pain and stop/slow further damage. Here, we present a brief summary of various past and present treatment modalities to address the complications associated with RA.
Asunto(s)
Artritis Reumatoide/tratamiento farmacológico , Corticoesteroides/efectos adversos , Corticoesteroides/uso terapéutico , Analgésicos Opioides/uso terapéutico , Antiinflamatorios no Esteroideos/efectos adversos , Antiinflamatorios no Esteroideos/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Antirreumáticos/efectos adversos , Antirreumáticos/uso terapéutico , Artritis Reumatoide/complicaciones , Artritis Reumatoide/cirugía , Humanos , Inmunosupresores/uso terapéutico , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Leflunamida/uso terapéutico , Modalidades de Fisioterapia , Factores de Riesgo , Factor de Necrosis Tumoral alfa/uso terapéuticoRESUMEN
Testicular germ cell tumors (TGCT) are the most frequent cancer among young men, with increasing incidence worldwide. Advanced paternal age has been linked to adverse health outcomes in offspring, but reports on the association of paternal age with TGCT are few and inconsistent. We aimed to examine the relationship of paternal age (PAB) at birth with the risk of TGCT and by histologic type: seminoma and non-seminoma. A population-based cohort of 1,056,058 males, examined at ages 16-19 between the years 1980-2011, was linked to the Israel National Cancer Registry to obtain incident TGCT through 2012. We applied multivariable Cox regression. During 16.5 million person-years of follow-up, 1247 incident cases (604 seminomas and 643 non-seminomas) were detected. Increasing PAB was linearly associated with lower risk of TGCT (HRper year = 0.983, 95% CI: 0.974-0.993, p = 0.001), after adjustment for year of birth, years of education, height, cryptorchidism history and origin, and also with additional adjustment for maternal age at birth (MAB) (HRper year = 0.980: 0.965-0.995, p = 0.008). The association was stronger for seminoma (HRper year = 0.968: 0.946-0.989, p = 0.004) and persisted in a subset adjusted for sibship size (HRper year = 0.950: 0.917-0.983, p = 0.003). In the fully adjusted model, young PAB (15-24 vs. ≥30) was a risk factor for seminoma (HR = 1.41: 1.07-1.85, p = 0.014). In models adjusted for PAB, MAB was not associated with risk of TGCT. In conclusion, our findings suggest that young paternal age is a risk factor of TGCT, especially seminoma. The findings warrant further investigation into the possible impact of young paternal age on their offsprings' testes.
Asunto(s)
Neoplasias de Células Germinales y Embrionarias/epidemiología , Edad Paterna , Neoplasias Testiculares/epidemiología , Adolescente , Adulto , Factores de Edad , Estudios de Cohortes , Humanos , Masculino , Factores de Riesgo , Adulto JovenRESUMEN
The resistance and pathogenesis of bacteria could be related to their ability to sense and respond to population density, termed quorum sensing (QS). Inhibition of the QS system is considered as a novel strategy for the development of antipathogenic agents, especially for combating drug-resistant bacterial infections. In the present study, the anti-QS activity of Onion peel ethylacetate fraction (ONE) was tested against Chromobacterium violaceum CV12472 and Pseudomonas aeruginosa PAO1. ONE inhibit the QS-mediated virulence factors production such as violacein in C. violaceum and elastase, pyocyanin in P. aeruginosa. Further, the treatment with sub-MICs of ONE significantly inhibited the QS-mediated biofilm formation, EPS (Extracellular polymeric substances) production and swarming motility. Further, quercetin 4'-O-ß-D glucopyranoside (QGP) was isolated from ONE and its anti-QS potential was confirmed after observing significant inhibition of QS-controlled virulence factors such as violacein, elastase, pyocyanin and biofilm formation in test pathogens. Molecular docking analysis predicted that QGP should be able to bind at the active sites of Vfr and LasR, and if so blocks the entry of active sites in Vfr and LasR.
RESUMEN
The fidelity of DNA replication is determined by many factors, here simplified as the contribution of the DNA polymerase (nucleotide selectivity and proofreading), mismatch repair, a balanced supply of nucleotides, and the condition of the DNA template (both in terms of sequence context and the presence of DNA lesions). This review discusses the contribution and interplay between these factors to the overall fidelity of DNA replication.
Asunto(s)
Núcleo Celular/enzimología , Replicación del ADN , ADN Polimerasa Dirigida por ADN/metabolismo , ADN/biosíntesis , Animales , Núcleo Celular/patología , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , ADN/química , ADN/genética , Daño del ADN , Reparación de la Incompatibilidad de ADN , Enzimas Reparadoras del ADN/metabolismo , ADN Polimerasa Dirigida por ADN/química , ADN Polimerasa Dirigida por ADN/genética , Inestabilidad Genómica , Humanos , Modelos Moleculares , Neoplasias/enzimología , Neoplasias/genética , Neoplasias/patología , Conformación de Ácido Nucleico , Conformación Proteica , Relación Estructura-ActividadRESUMEN
DNA polymerase ε (Pol ε) is a replicative DNA polymerase with an associated 3'-5' exonuclease activity. Here, we explored the capacity of Pol ε to perform strand displacement synthesis, a process that influences many DNA transactions in vivo We found that Pol ε is unable to carry out extended strand displacement synthesis unless its 3'-5' exonuclease activity is removed. However, the wild-type Pol ε holoenzyme efficiently displaced one nucleotide when encountering double-stranded DNA after filling a gap or nicked DNA. A flap, mimicking a D-loop or a hairpin structure, on the 5' end of the blocking primer inhibited Pol ε from synthesizing DNA up to the fork junction. This inhibition was observed for Pol ε but not with Pol δ, RB69 gp43 or Pol η. Neither was Pol ε able to extend a D-loop in reconstitution experiments. Finally, we show that the observed strand displacement synthesis by exonuclease-deficient Pol ε is distributive. Our results suggest that Pol ε is unable to extend the invading strand in D-loops during homologous recombination or to add more than two nucleotides during long-patch base excision repair. Our results support the hypothesis that Pol ε participates in short-patch base excision repair and ribonucleotide excision repair.
Asunto(s)
ADN Polimerasa II/metabolismo , ADN de Hongos/biosíntesis , Saccharomyces cerevisiae/enzimología , ADN de Hongos/química , Conformación de Ácido Nucleico , Nucleótidos/metabolismo , Subunidades de Proteína/metabolismo , Cloruro de Sodio/farmacología , Especificidad por Sustrato/efectos de los fármacosRESUMEN
Chronic alcohol consumption induces multi-organ damage, including alcoholic liver disease (ALD), pancreatitis and hypertension. Ethanol and ethanol metabolic products play a significant role in the manifestation of its toxicity. Ethanol metabolizes to acetaldehyde and produces reduced nicotinamide adenine dinucleotide (NADH) by cytosolic alcohol dehydrogenase. Ethanol metabolism mediated by cytochrome-P450 2E1 causes oxidative stress due to increased production of reactive oxygen species (ROS). Acetaldehyde, increased redox cellular state and ROS activate transcription factors, which in turn activate genes for lipid biosynthesis and offer protection of hepatocytes from alcohol toxicity. Sterol regulatory element binding proteins (SREBPs) and peroxisome proliferator activated-receptors (PPARs) are two key lipogenic transcription factors implicated in the development of fatty liver in alcoholic and non-alcoholic steatohepatitis. SREBP-1 is activated in the livers of chronic ethanol abusers. An increase in ROS activates nuclear factor erythroid-2-related factor-2 (Nrf2) and hypoxia inducible factor (HIF) to provide protection to hepatocytes from ethanol toxicity. Under ethanol exposure, due to increased gut permeability, there is release of gram-negative bacteria-derived lipopolysaccharide (LPS) from intestine causing activation of immune response. In addition, the metabolic product, acetaldehyde, modifies the proteins in hepatocyte, which become antigens inviting auto-immune response. LPS activates macrophages, especially the liver resident macrophages, Kupffer cells. These Kupffer cells and circulating macrophages secrete various cytokines. The level of tumor necrosis factor-α (TNFα), interleukin-1beta (IL-1ß), IL-6, IL-8 and IL-12 have been found elevated among chronic alcoholics. In addition to elevation of these cytokines, the peripheral iron (Fe(2+)) is also mobilized. An increased level of hepatic iron has been observed among alcoholics. Increased ROS, IL-1ß, acetaldehyde, and increased hepatic iron, all activate nuclear factor-kappa B (NF-κB) transcription factor. Resolution of increased reactive oxygen species requires increased expression of genes responsible for dismutation of increased ROS which is partially achieved by IL-6 mediated activation of signal transducers and activators of transcription 3 (STAT3). In addition to these transcription factors, activator protein-1 may also be activated in hepatocytes due to its association with resolution of increased ROS. These transcription factors are central to alcohol-mediated hepatotoxicity.
Asunto(s)
Consumo de Bebidas Alcohólicas/metabolismo , Hígado Graso/metabolismo , Hipertensión/metabolismo , Factores de Transcripción/metabolismo , Animales , Etanol/farmacocinética , Etanol/toxicidad , Hígado Graso/inducido químicamente , Humanos , Hipertensión/inducido químicamente , Estrés OxidativoRESUMEN
Atherosclerosis is a chronic inflammatory disease associated with cardiovascular dysfunction including myocardial infarction, unstable angina, sudden cardiac death, stroke and peripheral thromboses. It has been predicted that atherosclerosis will be the primary cause of death in the world by 2020. Atherogenesis is initiated by endothelial injury due to oxidative stress associated with cardiovascular risk factors including diabetes mellitus, hypertension, cigarette smoking, dyslipidemia, obesity, and metabolic syndrome. The impairment of the endothelium associated with cardiovascular risk factors creates an imbalance between vasodilating and vasoconstricting factors, in particular, an increase in angiotensin II (Ang II) and a decrease in nitric oxide. The renin-angiotensin system (RAS), and its primary mediator Ang II, also have a direct influence on the progression of the atherosclerotic process via effects on endothelial function, inflammation, fibrinolytic balance, and plaque stability. Anti-inflammatory agents [statins, secretory phospholipase A2 inhibitor, lipoprotein-associated phospholipase A2 inhibitor, 5-lipoxygenase activating protein, chemokine motif ligand-2, C-C chemokine motif receptor 2 pathway inhibitors, methotrexate, IL-1 pathway inhibitor and RAS inhibitors (angiotensin-converting enzyme inhibitors)], Ang II receptor blockers and ranin inhibitors may slow inflammatory processes and disease progression. Several studies in human using anti-inflammatory agents and RAS inhibitors revealed vascular benefits and reduced progression of coronary atherosclerosis in patients with stable angina pectoris; decreased vascular inflammatory markers, improved common carotid intima-media thickness and plaque volume in patients with diagnosed atherosclerosis. Recent preclinical studies have demonstrated therapeutic efficacy of vitamin D analogs paricalcitol in ApoE-deficient atherosclerotic mice.