RESUMO
BACKGROUND: Immunization information systems (IIS) are confidential, population-based computerized databases that record vaccination doses administered to persons residing within a given geopolitical area. We sought to highlight the evolution of IIS policy over the last two decades, as IIS play a pivotal role in achieving equitable and high vaccine uptake. METHODS: Legal epidemiological research methods were used to assess relevant IIS statutes and administrative codes across all 50 states, the District of Columbia, Philadelphia, and New York City. Where relevant, laws were cross-checked or supplemented with state and local health department resources. Comparisons to previous legal studies enabled evaluation of trends in IIS laws over time. RESULTS: The compilation of current laws provides an updated overview of the diverse interstate and intrastate policies within the US that govern the capabilities and implementation of IIS. The findings of this study show the progress that has been made in the past decade in improving policies that enable IIS to be utilized across the life-course. Conversely, gaps in IIS data collection, limited interoperability with local and national health information systems, and inconsistent access to view or utilize IIS records due to existing policies, continue to limit the full potential of IIS. CONCLUSIONS: In the United States (US), IIS are implemented and managed at the state and local level, creating variability in IIS policies and implementation. Findings from this study serve as a comprehensive benchmark of current IIS laws that may aid policy stakeholders who are exploring amendments to jurisdictional IIS laws.
Assuntos
Sistemas de Informação em Saúde , Vacinação , Humanos , Imunização , Benchmarking , PolíticasRESUMO
BACKGROUND: Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) uses full-length angiotensin converting enzyme 2 (ACE2) as a main receptor to enter target cells. The goal of this study was to demonstrate the preclinical efficacy of a novel soluble ACE2 protein with increased duration of action and binding capacity in a lethal mouse model of COVID-19. METHODS: A human soluble ACE2 variant fused with an albumin binding domain (ABD) was linked via a dimerization motif hinge-like 4-cysteine dodecapeptide (DDC) to improve binding capacity to SARS-CoV-2. This novel soluble ACE2 protein (ACE2-1-618-DDC-ABD) was then administered intranasally and intraperitoneally to mice before intranasal inoculation of SARS-CoV-2 and then for two additional days post viral inoculation. RESULTS: Untreated animals became severely ill, and all had to be humanely euthanized by day 6 or 7 and had pulmonary alveolar hemorrhage with mononuclear infiltrates. In contrast, all but one mouse infected with a lethal dose of SARS-CoV-2 that received ACE2-1-618-DDC-ABD survived. In the animals inoculated with SARS-CoV-2 that were untreated, viral titers were high in the lungs and brain, but viral titers were absent in the kidneys. Some untreated animals, however, had variable degrees of kidney proximal tubular injury as shown by attenuation of the proximal tubular brush border and increased NGAL and TUNEL staining. Viral titers in the lung and brain were reduced or nondetectable in mice that received ACE2-1-618-DDC-ABD, and the animals developed only moderate disease as assessed by a near-normal clinical score, minimal weight loss, and improved lung and kidney injury. CONCLUSIONS: This study demonstrates the preclinical efficacy of a novel soluble ACE2 protein, termed ACE2-1-618-DDC-ABD, in a lethal mouse model of SARS-CoV-2 infection that develops severe lung injury and variable degrees of moderate kidney proximal tubular injury.
Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Enzima de Conversão de Angiotensina 2/uso terapêutico , Animais , COVID-19/terapia , Rim/virologia , Pulmão/virologia , Camundongos , SARS-CoV-2RESUMO
Conceivably, like other forms of acute kidney injury, cadmium-induced renal injury may also be associated with oxidative stress and various forms of cell death, including necroptosis, a form of regulated necrosis-associated cell death. Myo-inositol oxygenase (MIOX), an enzyme localized in renal proximal tubules, regulates oxidative stress and programmed cell death in various forms of renal injuries. Herein, the role and potential mechanism(s) by which MIOX potentiates cadmium-induced renal tubular damage were investigated. Overexpression of MIOX exacerbated cadmium-induced cell death and proximal tubular injury in mice, whereas MIOX gene disruption attenuated cellular damage in vitro and in vivo. Furthermore, necroptosis was observed in the renal tubular compartment, and, more importantly, it was corroborated by inhibitor experiments with necrostatin-1 (Nec-1). Coadministration of Nec-1 dampened including receptor-interacting protein kinase (RIP)1/RIP3/mixed-lineage kinase domain-like signaling, which is relevant to the process of necroptosis. Interestingly, the necroptosis induced by cadmium in tubules was modulated by MIOX expression profile. Also, the increased reactive oxygen species generation and NADPH consumption were accelerated by MIOX overexpression, and they were mitigated by Nec-1 administration. These findings suggest that MIOX-potentiated redox injury and necroptosis are intricately involved in the pathogenesis of cadmium-induced nephropathy, and this may yield novel potential therapeutic targets for amelioration of cadmium-induced kidney injury.NEW & NOTEWORTHY This is a seminal article documenting the role of myo-inositol oxygenase (MIOX), a renal proximal tubule-specific enzyme, in the exacerbation of cadmium-induced acute kidney injury by perturbing redox balance and inducing necroptosis. MIOX gene disruption or administration of necrostatin-1 (a necroptosis inhibitor) diminished cadmium-induced renal damage, in both in vitro and in vivo systems, suggesting a therapeutic potential of MIOX to attenuate necroptosis and relevant signaling pathways in cadmium-induced renal injury.
Assuntos
Injúria Renal Aguda , Inositol Oxigenase , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Injúria Renal Aguda/metabolismo , Animais , Cádmio/metabolismo , Cádmio/toxicidade , Feminino , Humanos , Inositol Oxigenase/genética , Inositol Oxigenase/metabolismo , Rim/metabolismo , Masculino , Camundongos , Necroptose , OxidantesRESUMO
History Part one of this case appeared 4 months previously and may contain larger images. A 40-year-old woman presented to the outpatient department of our hospital with a 2-year history of abdominal pain, which had worsened in the past few days. There were no other constitutional symptoms; in particular, there was no weight loss or loss of appetite. The serum amylase and serum lipase levels were always within normal limits, even during the current episode. There was no history of pancreatitis, alcohol abuse, drug use, or trauma. The patient was evaluated at an outside clinic 2 years ago and underwent imaging, including US and dedicated pancreatic CT, which revealed a complex multiseptated noncalcified pancreatic cystic lesion. After CT, the patient underwent endoscopic US, which showed the lesion was suspected to be an infected parasitic cyst; fine-needle aspiration and cytology were not attempted due to the risk of iatrogenic rupture. The patient was advised to undergo surgical resection but declined the procedure and was lost to follow-up for 2 years before her current visit to our facility. On clinical examination, there were no clinically important findings, aside from mild to moderate pain on deep palpation and some shifting dullness that was suggestive of ascites. The patient always remained hemodynamically stable. US-guided ascitic fluid analysis was performed, which revealed amylase levels of 869 IU/L (normal range, 4-234 IU/L). Considering prior CT and endoscopic US reports, the patient was further evaluated with a pancreatic MRI protocol for lesion characterization and to explain the new-onset abdominal pain.
Assuntos
Cistadenoma Mucinoso , Neoplasias Pancreáticas , Dor Abdominal/diagnóstico por imagem , Dor Abdominal/etiologia , Adulto , Amilases , Cistadenoma Mucinoso/diagnóstico por imagem , Cistadenoma Mucinoso/cirurgia , Feminino , Humanos , Pâncreas/patologia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/cirurgiaRESUMO
MAIN CONCLUSION: Manipulation of autophagic pathway represents a tremendous opportunity for designing climate-smart crops with improved yield and better adaptability to changing environment. For exploiting autophagy to its full potential, identification and comprehensive characterization of adapters/receptor complex and elucidation of its regulatory network in crop plants is highly warranted. Autophagy is a major intracellular trafficking pathway in eukaryotes involved in vacuolar degradation of cytoplasmic constituents, mis-folded proteins, and defective organelles. Under optimum conditions, autophagy operates at a basal level to maintain cellular homeostasis, but under stressed conditions, it is induced further to provide temporal stress relief. Our understanding of this highly dynamic process has evolved exponentially in the past few years with special reference to several plant-specific roles of autophagy. Here, we review the most recent advances in the field of autophagy in plants and discuss its potential implications in designing crops with improved stress and disease-tolerance, enhanced yield potential, and improved capabilities for producing metabolites of high economic value. We also assess the current knowledge gaps and the possible strategies to develop a robust module for biotechnological application of autophagy to enhance bioeconomy and sustainability of agriculture.
Assuntos
Autofagia , Desenvolvimento Vegetal , Vacúolos , Produtos Agrícolas/genéticaRESUMO
Diabetic retinopathy (DR) is a chronic microvascular complication of diabetes mellitus (DM). It is a worldwide growing epidemic disease considered to be the leading cause of vision-loss and blindness in people with DM. Redox reactions occurring at the extra- and intracellular levels are essential for the maintenance of cellular homeostasis. Dysregulation of redox homeostasis are implicated in the onset and development of DR. Thioredoxin1 (TRX1) and Thioredoxin2 (TRX2) are cytoplasmic and mitochondrially localized antioxidant proteins ubiquitously expressed in various cells and control cellular reactive oxygen species (ROS) by reducing the disulfides into thiol groups. Thioredoxin-interacting protein (TXNIP) binds to TRX system and inhibits the active reduced form of TRX through disulfide exchange reaction. Recent studies indicate the association of TRX/TXNIP with redox signal transduction pathways including activation of Nod-like receptor pyrin domain containing protein-3 (NLRP3) inflammasome, apoptosis, autophagy/mitophagy, epigenetic modifications in a redox-dependent manner. Thus, it is important to gain a more in-depth understanding about the cellular and molecular mechanisms that links redoxisome and ER/Mitochondrial dysfunction to drive the progression of DR. The purpose of this review is to provide a mechanistic understanding of the complex molecular mechanisms and pathophysiological roles associated with redoxisome, the TRX/TXNIP redox signaling complex under oxidative stress in the development of DR. Also, the molecular targets of FDA approved drugs and clinical trials in addition to effective antioxidant strategies for the treatment of diabetic retinopathy are reviewed.
Assuntos
Diabetes Mellitus , Retinopatia Diabética , Antioxidantes/metabolismo , Retinopatia Diabética/tratamento farmacológico , Retinopatia Diabética/metabolismo , Humanos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxinas/metabolismoRESUMO
Postsecond wave of COVID-19 pandemic in the year 2021, rhino-orbital mucormycosis (ROM) was seen as an epidemic in the Indian community. Severe ROM disease has poor prognosis and requires a multidisciplinary approach for treatment. Hence, its prevention is better than cure. Studies done during the epidemic assessed predisposing factors, but this was a novel study which focused on assessing risk factors for severe disease of ROM. Ninety-four consecutive patients of ROM admitted at our designated nodal tertiary hospital of North India were enrolled, and data were collected and analyzed. Facial edema was the most common presenting complaint. Subclinical and mild COVID-19 infection was associated with severe ROM. Uncontrolled diabetes mellitus and prophylactic zinc supplementation were other significant risk factors for severe ROM. Public awareness among the general population for the above risk factors can prevent a debilitating disease like severe ROM.
Assuntos
COVID-19 , Mucormicose , Humanos , Mucormicose/epidemiologia , Pandemias , Índia/epidemiologia , Fatores de RiscoRESUMO
Regulated cell death (RCD), distinct from accidental cell death, refers to a process of well-controlled programmed cell death with well-defined pathological mechanisms. In the past few decades, various terms for RCDs were coined, and some of them have been implicated in the pathogenesis of various types of acute kidney injury (AKI). Cisplatin is widely used as a chemotherapeutic drug for a broad spectrum of cancers, but its usage was hampered because of being highly nephrotoxic. Cisplatin-induced AKI is commonly seen clinically, and it also serves as a well-established prototypic model for laboratory investigations relevant to acute nephropathy affecting especially the tubular compartment. Literature reports over a period of three decades have indicated that there are multiple types of RCDs, including apoptosis, necroptosis, pyroptosis, ferroptosis, and mitochondrial permeability transition-mediated necrosis, and some of them are pertinent to the pathogenesis of cisplatin-induced AKI. Interestingly, myo-inositol metabolism, a vital biological process that is largely restricted to the kidney, seems to be relevant to the pathogenesis of certain forms of RCDs. A comprehensive understanding of RCDs in cisplatin-induced AKI and their relevance to myo-inositol homeostasis may yield novel therapeutic targets for the amelioration of cisplatin-related nephropathy.
Assuntos
Injúria Renal Aguda/induzido quimicamente , Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Inositol/metabolismo , Necroptose/efeitos dos fármacos , Injúria Renal Aguda/patologia , Animais , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Camundongos Endogâmicos C57BL , Necrose/metabolismo , Necrose/patologia , Morte Celular Regulada/efeitos dos fármacosRESUMO
Small GTP-binding proteins from the ADP-ribosylation factor (ARF) family are important regulators of vesicle formation and cellular trafficking in all eukaryotes. ARF activation is accomplished by a protein family of guanine nucleotide exchange factors (GEFs) that contain a conserved catalytic Sec7 domain. Here, we identified and characterized Secdin, a small-molecule inhibitor of Arabidopsis thaliana ARF-GEFs. Secdin application caused aberrant retention of plasma membrane (PM) proteins in late endosomal compartments, enhanced vacuolar degradation, impaired protein recycling, and delayed secretion and endocytosis. Combined treatments with Secdin and the known ARF-GEF inhibitor Brefeldin A (BFA) prevented the BFA-induced PM stabilization of the ARF-GEF GNOM, impaired its translocation from the Golgi to the trans-Golgi network/early endosomes, and led to the formation of hybrid endomembrane compartments reminiscent of those in ARF-GEF-deficient mutants. Drug affinity-responsive target stability assays revealed that Secdin, unlike BFA, targeted all examined Arabidopsis ARF-GEFs, but that the interaction was probably not mediated by the Sec7 domain because Secdin did not interfere with the Sec7 domain-mediated ARF activation. These results show that Secdin and BFA affect their protein targets through distinct mechanisms, in turn showing the usefulness of Secdin in studies in which ARF-GEF-dependent endomembrane transport cannot be manipulated with BFA.
Assuntos
Arabidopsis/efeitos dos fármacos , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Ftalazinas/farmacologia , Piperazinas/farmacologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brefeldina A/farmacologia , Endocitose/efeitos dos fármacos , Endossomos/efeitos dos fármacos , Endossomos/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Plantas Geneticamente Modificadas , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Transporte Proteico , Vacúolos/efeitos dos fármacos , Vacúolos/metabolismoRESUMO
Clathrin-mediated endocytosis (CME) is a highly conserved and essential cellular process in eukaryotic cells, but its dynamic and vital nature makes it challenging to study using classical genetics tools. In contrast, although small molecules can acutely and reversibly perturb CME, the few chemical CME inhibitors that have been applied to plants are either ineffective or show undesirable side effects. Here, we identify the previously described endosidin9 (ES9) as an inhibitor of clathrin heavy chain (CHC) function in both Arabidopsis and human cells through affinity-based target isolation, in vitro binding studies and X-ray crystallography. Moreover, we present a chemically improved ES9 analog, ES9-17, which lacks the undesirable side effects of ES9 while retaining the ability to target CHC. ES9 and ES9-17 have expanded the chemical toolbox used to probe CHC function, and present chemical scaffolds for further design of more specific and potent CHC inhibitors across different systems.
Assuntos
Derivados de Benzeno/farmacologia , Cadeias Pesadas de Clatrina/antagonistas & inibidores , Endocitose/efeitos dos fármacos , Arabidopsis , Derivados de Benzeno/química , Cadeias Pesadas de Clatrina/metabolismo , Humanos , Modelos Moleculares , Estrutura Molecular , Tiofenos/farmacologiaRESUMO
BACKGROUND: To strengthen health systems, the shortage of physicians globally needs to be addressed. However, efforts to increase the numbers of physicians must be balanced with controls on medical education imparted and the professionalism of doctors licensed to practise medicine. METHODS: We conducted a multi-country comparison of mandatory regulations and voluntary guidelines to control standards for medical education, clinical training, licensing and re-licensing of doctors. We purposively selected seven case-study countries with differing health systems and income levels: Canada, China, India, Iran, Pakistan, UK and USA. Using an analytical framework to assess regulations at four sequential stages of the medical education to relicensing pathway, we extracted information from: systematically collected scientific and grey literature and online news articles, websites of regulatory bodies in study countries, and standardised input from researchers and medical professionals familiar with rules in the study countries. RESULTS: The strictest controls we identified to reduce variations in medical training, licensing and re-licensing of doctors between different medical colleges, and across different regions within a country, include: medical education delivery restricted to public sector institutions; uniform, national examinations for medical college admission and licensing; and standardised national requirements for relicensing linked to demonstration of competence. However, countries analysed used different combinations of controls, balancing the strictness of controls across the four stages. CONCLUSIONS: While there is no gold standard model for medical education and practise regulation, examining the combinations of controls used in different countries enables identification of innovations and regulatory approaches to address specific contextual challenges, such as decentralisation of regulations to sub-national bodies or privatisation of medical education. Looking at the full continuum from medical education to licensing is valuable to understand how countries balance the strictness of controls at different stages. Further research is needed to understand how regulating authorities, policy-makers and medical associations can find the right balance of standardisation and context-based flexibility to produce well-rounded physicians.
Assuntos
Educação Médica , Medicina , Médicos , Competência Clínica , Humanos , ÍndiaRESUMO
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system and is caused by an aberrant immune response to myelin sheath. Disease-modifying medications, which mainly aim to suppress such aberrant immune response, have significantly improved MS treatment. However, the disease severity continues to worsen. In contrast, progressively more data suggest that 1,25-dihydroxyvitamin D or 1,25(OH)2D, i.e., the active vitamin D, suppresses the differentiation of potentially pathogenic T cells associated with MS, enhances the differentiation of regulatory T cells that suppress the pathogenic T cells, and promotes remyelination. These novel 1,25(OH)2D functions have encouraged investigators to develop vitamin D as a potential therapy for MS. However, because of the hypercalcemia that is associated with high 1,25(OH)2D concentrations, supplementation of native vitamin D has been a major focus in clinical trials for the treatment of MS, but such trials have produced mixed data. In this article, we will review current progress in the supplementation of different vitamin D forms for the treatment of experimental autoimmune encephalomyelitis (i.e., an MS animal model) as well as MS. Furthermore, we will review alternative strategies that our laboratory and others are pursuing in an attempt to circumvent the hurdles that are hampering the effective use of vitamin D as a potential therapy for MS.
Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Esclerose Múltipla/tratamento farmacológico , Vitamina D/uso terapêutico , Animais , Ensaios Clínicos como Assunto , Encefalomielite Autoimune Experimental/imunologia , Humanos , Esclerose Múltipla/imunologia , Índice de Gravidade de Doença , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismo , Resultado do Tratamento , Vitamina D/farmacologiaRESUMO
Besides oxidant stress, endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of various metabolic disorders affecting the kidney. These two forms of stresses are not mutually exclusive to each other and may operate by a feedback loop in worsening the cellular injury. To attest to this contention, studies were performed to assess whether in such a setting, there is worsening of tubulointerstitial injury. We employed tunicamycin as a model of ER stress and used tubular cells and mice overexpressing myo-inositol oxygenase (MIOX), an enzyme involved in glycolytic events with excessive generation of ROS. Concomitant treatment of tunicamycin and transfection of cells with MIOX-pcDNA led to a marked generation of ROS, which was reduced by MIOX-siRNA. Likewise, an accentuated expression of ER stress sensors, GRP78, XBP1, and CHOP, was observed, which was reduced with MIOX-siRNA. These sensors were markedly elevated in MIOX-TG mice compared with WT treated with tunicamycin. This was accompanied with marked deterioration of tubular morphology, along with impairment of renal functions. Interestingly, minimal damage and elevation of ER stressors was observed in MIOX-KO mice. Downstream events that were more adversely affected in MIOX-TG mice included accentuated expression of proapoptogenic proteins, proinflammatory cytokines, and extracellular matrix constituents, although expression of these molecules was unaffected in MIOX-KO mice. Also, their tunicamycin-induced accentuated expression in tubular cells was notably reduced with MIOX-siRNA. These studies suggest that the biology of MIOX-induced oxidant stress and tunicamycin-induced ER stress are interlinked, and both of the events may feed into each other to amplify the tubulointerstitial injury.
Assuntos
Estresse do Retículo Endoplasmático , Inositol Oxigenase/metabolismo , Nefropatias/enzimologia , Túbulos Renais Proximais/enzimologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Modelos Animais de Doenças , Chaperona BiP do Retículo Endoplasmático , Humanos , Inositol Oxigenase/genética , Nefropatias/induzido quimicamente , Nefropatias/genética , Nefropatias/patologia , Túbulos Renais Proximais/patologia , Células LLC-PK1 , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Suínos , TunicamicinaRESUMO
EchAMP, the tenth most abundant transcript expressed in the mammary gland of echidna, has in vitro broad-spectrum antibacterial effects. However, the effects of EchAMP on mastitis, a condition where inflammation is triggered following mammary gland infection, has not been investigated. To investigate the impact of EchAMP against mastitis, EchAMP transgenic mice were generated. In antibacterial assays, the whey fractions of milk from transgenic mice significantly reduced growth of Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa compared with whey fractions from wildtype mice. Furthermore, a mastitis model created by infecting mammary gland with these four bacterial strains displayed a significant reduction in bacterial load in transgenic mice injected with S. aureus and B. subtilis. On further confirmation, histomorphologic analysis showed absence of necrosis and cell infiltration in the mammary glands of transgenic mice. To understand the role of EchAMP against inflammation, we employed an LPS-injected mastitis mouse model. LPS is known to induce phopshorylation of NF-κB and MAPK pathways, which in turn activate downstream proinflammatory signaling mediators, to promote inflammation. In LPS-treated EchAMP transgenic mice, phosphorylation levels of NF-κB, p38 and ERK1/2 were significantly downregulated. Furthermore, in mammary gland of transgenic mice, there was a significant downregulation of mRNA levels of proinflammatory cytokines, namely TNF-α, IL-6 and IL-1ß. Taken together, these data suggest that EchAMP has an antiinflammatory response and is effective against S. aureus and B. subtilis. We suggest that EchAMP may be a potential prophylactic protein against mastitis in dairy animals by expressing this gene in their mammary gland.
Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Inflamação/genética , Mastite/genética , Infecções Estafilocócicas/genética , Animais , Feminino , Humanos , Inflamação/induzido quimicamente , Inflamação/microbiologia , Inflamação/prevenção & controle , Interleucina-1beta/genética , Interleucina-6/genética , Lipopolissacarídeos/toxicidade , Sistema de Sinalização das MAP Quinases/genética , Glândulas Mamárias Animais/metabolismo , Mastite/induzido quimicamente , Mastite/microbiologia , Mastite/prevenção & controle , Camundongos , Camundongos Transgênicos/genética , NF-kappa B/genética , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Tachyglossidae/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
Advanced glycation end products (AGEs) play a role in pathogenesis of diabetic nephropathy (DN). Myo-inositol oxygenase (MIOX) has been implicated in tubulointerstitial injury in the context of DN. We investigated the effect of AGEs on MIOX expression and delineated mechanisms that lead to tubulointerstitial injury. The status of MIOX, RAGE, and relevant cellular signaling pathways activated following AGE:RAGE interaction was examined in tubular cells and kidneys of AGE-BSA-treated mice. A solid-phase assay revealed an enhanced binding of RAGE with AGE-BSA, AGE-laminin, and AGE-collagen IV. The cells treated with AGE-BSA had increased MIOX activity/expression and promoter activity. This was associated with activation of various signaling kinases of phosphatidylinositol 3-kinase (PI3K)-AKT pathway and increased expression of NF-κB, transforming growth factor (TGF)-ß, and fibronectin, which was negated with the treatment of MIOX/RAGE- small interfering (si) RNA. Concomitant with MIOX upregulation, there was an increased generation of reactive oxygen species (ROS), which could be abrogated with MIOX/RAGE- siRNA treatment. The kidneys of mice treated with AGE-BSA had significantly high urinary A/C ratio, upregulation of MIOX, RAGE and NF-κB, along with influx of monocytes into the tubulointerstitium, increased the expression of MCP-1, IL-6, and fibronectin and increased the generation of ROS. Such perturbations were abrogated with the concomitant treatment of inhibitors MIOX or RAGE (d-glucarate and FPS-ZM1). These studies support a role of AGE:RAGE interaction in the activation of PI3K-AKT pathway and upregulation of MIOX, with excessive generation of ROS, increased expression of NF-κB, inflammatory cytokines, TGF-ß, and fibronectin. Collectively, these observations highlight the relevance of the biology of MIOX in the contribution toward tubulointerstitial injury in DN.
Assuntos
Nefropatias Diabéticas/metabolismo , Fibronectinas/metabolismo , Inositol Oxigenase/metabolismo , Rim/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Soroalbumina Bovina/metabolismoRESUMO
Plant cells rely on numerous membrane-localized receptor kinases for communication with each other as well as with the environment to ensure coordinated growth, development and survival. Additionally, several families of small secreted peptides have been identified in plants that possibly regulate various developmental processes through activation of specific membrane receptor kinases. In research efforts to elucidate the underlying signaling processes in plants, it has become obvious that knowledge of both the extracellular ligand and its corresponding receptor(s) is a prerequisite to understand cell communication. Of more than 1,000 orphan peptides in plants, only a few have been functionally characterized and paired with their respective receptors. Here, we discuss recent advances made in the field of receptor-ligand pairing and visualization in plant cells by means of chemically labeled ligands. We summarize and compare various chemical strategies from the mammalian field that can be employed to extend our understanding of the plant receptor kinase functions in plants.
Assuntos
Proteínas de Plantas/metabolismo , Plantas/metabolismo , Comunicação Celular/genética , Comunicação Celular/fisiologia , Proteínas de Plantas/genética , Plantas/genéticaRESUMO
The catabolic enzyme myo-inositol oxygenase (MIOX) is expressed in proximal tubules and up-regulated in the diabetic state. Previously, we reported its transcriptional and translation regulation by high glucose (HG), osmolytes, and fatty acids. However, its epigenetic regulation is unknown. Bisulfite sequencing revealed that both human and mouse MIOX promoters, enriched with CpG sites, are hypomethylated and unmethylated under HG ambience and hyperglycemic states associated with increased MIOX expression. Eletrophoretic mobility shift assays revealed increased binding of unmethylated oligos with nucleoproteins of cells maintained under HG. In addition, a strong binding of specificity protein (Sp)-1 transcription factor with MIOX promoter was observed under HG, especially with unmethylated Sp-1 oligo. Specificity of binding was established by supershift assays and treatment with the Sp-1 inhibitor mithramycin. Promoter analysis revealed an increase in luciferase activity under HG, which was reduced after mutation of the Sp-1-binding site. Sp1 siRNA treatment reduced mRNA and protein expression of Sp-1 and MIOX and generation of reactive oxygen species derived from NADPH oxidase (NOX)-4 and mitochondrial sources. In addition, there was reduced expression of hypoxia-inducible factor-1α relevant in the pathogenesis of diabetic nephropathy. Sp1 siRNA treatment reduced fibronectin expression, an extracellular matrix protein that is increased in diabetic nephropathy and tubulopathy. HG-induced MIOX expression was also reduced with the treatment of apelin-13, which deacetylates histones. Overall, these findings highlight the epigenetic regulation of MIOX in the pathogenesis of diabetic tubulopathy.
Assuntos
Metilação de DNA/genética , Nefropatias Diabéticas/enzimologia , Nefropatias Diabéticas/patologia , Glucose/toxicidade , Inositol Oxigenase/metabolismo , Fator de Transcrição Sp1/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Ilhas de CpG/genética , Nefropatias Diabéticas/genética , Fibronectinas/metabolismo , Deleção de Genes , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Inositol Oxigenase/genética , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Nucleoproteínas/metabolismo , Oxirredução/efeitos dos fármacos , Regiões Promotoras Genéticas , Ligação Proteica/efeitos dos fármacos , RNA Interferente Pequeno/metabolismoRESUMO
Overexpression of the proximal tubular enzyme myo-inositol oxygenase (MIOX) induces oxidant stress in vitro However, the relevance of MIOX to tubular pathobiology remains enigmatic. To investigate the role of MIOX in cisplatin-induced tubular AKI, we generated conditional MIOX-overexpressing transgenic (MIOX-TG) mice and MIOX-knockout (MIOX-/-) mice with tubule-specific MIOX overexpression or knockout, respectively. Compared with cisplatin-treated wild-type (WT) mice, cisplatin-treated MIOX-TG mice had even greater increases in urea, creatinine, and KIM-1 levels and more tubular injury and apoptosis, but these effects were attenuated in cisplatin-treated MIOX-/- mice. Similarly, MIOX-TG mice had the highest and MIOX-/- mice had the lowest renal levels of Bax, cleaved caspase-3, and NADPH oxidase-4 expression and reactive oxygen species (ROS) generation after cisplatin treatment. In vitro, cisplatin dose-dependently increased ROS generation in LLC-PK1 cells. Furthermore, MIOX overexpression in these cells accentuated cisplatin-induced ROS generation and perturbations in the ratio of GSH to oxidized GSH, whereas MIOX-siRNA or N-acetyl cysteine treatment attenuated these effects. Additionally, the cisplatin-induced enhancement of p53 activation, NF-κB binding to DNA, and NF-κB nuclear translocation in WT mice was exacerbated in MIOX-TG mice but absent in MIOX-/- mice. In vitro, MIOX-siRNA or NAC treatment reduced the dose-dependent increase in p53 expression induced by cisplatin. We also observed a remarkable influx of inflammatory cells and upregulation of cytokines in kidneys of cisplatin-treated MIOX-TG mice. Finally, analysis of genomic DNA in WT mice revealed cisplatin-induced hypomethylation of the MIOX promoter. These data suggest that MIOX overexpression exacerbates, whereas MIOX gene disruption protects against, cisplatin-induced AKI.
Assuntos
Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/enzimologia , Cisplatino/efeitos adversos , Inositol Oxigenase/deficiência , Animais , Inositol Oxigenase/fisiologia , Masculino , Camundongos , Camundongos Knockout , Camundongos TransgênicosRESUMO
BACKGROUND: Salinity stress is a major constrain in the global rice production and hence serious efforts are being undertaken towards deciphering its remedial strategies. The comparative analysis of differential response of salt sensitive and salt tolerant lines is a judicious approach to obtain essential clues towards understanding the acquisition of salinity tolerance in rice plants. However, adaptation to salt stress is a fairly complex process and operates through different mechanisms. Among various mechanisms involved, the reactive oxygen species mediated salinity tolerance is believed to be critical as it evokes cascade of responses related to stress tolerance. In this background, the present paper for the first time evaluates the ROS generating and the scavenging system in tandem in both salt sensitive and salt tolerant cultivars of rice for getting better insight into salinity stress adaptation. RESULTS: Comparative analysis of ROS indicates the higher level of hydrogen peroxide (H2O2) and lower level of superoxide ions (O(2-)) in the salt tolerant as compared to salt sensitive cultivars. Specific activity of ROS generating enzyme, NADPH oxidase was also found to be more in the tolerant cultivars. Further, activities of various enzymes involved in enzymatic and non enzymatic antioxidant defence system were mostly higher in tolerant cultivars. The transcript level analysis of antioxidant enzymes were in alignment with the enzymatic activity. Other stress markers like proline were observed to be higher in tolerant varieties whereas, the level of malondialdehyde (MDA) equivalents and chlorophyll content were estimated to be more in sensitive. CONCLUSION: The present study showed significant differences in the level of ROS production and antioxidant enzymes activities among sensitive and tolerant cultivars, suggesting their possible role in providing natural salt tolerance to selected cultivars of rice. Our study demonstrates that the cellular machinery for ROS production and scavenging system works in an interdependent manner to offer better salt stress adaptation in rice. The present work further highlights that the elevated level of H2O2 which is considered as a key determinant for conferring salt stress tolerance to rice might have originated through an alternative route of photocatalytic activity of chlorophyll.
Assuntos
Sequestradores de Radicais Livres/metabolismo , Oryza/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Cloreto de Sódio/metabolismo , Clorofila/metabolismo , Malondialdeído/metabolismo , Oryza/genética , Estresse Oxidativo , Tolerância ao SalRESUMO
Alzheimer's disease (AD) is a neurodegenerative disorder in which the death of brain cells causes memory loss and cognitive decline, i.e., dementia. The disease starts with mild symptoms and gradually becomes severe. AD is one of the leading causes of mortality worldwide. Several different hallmarks of the disease have been reported such as deposits of ß-amyloid around neurons, hyperphosphorylated tau protein, oxidative stress, dyshomeostasis of bio-metals, low levels of acetylcholine, etc. AD is not simple to diagnose since there is no single diagnostic test for it. Pharmacotherapy for AD currently provides only symptomatic relief and mostly targets cognitive revival. Computational biology approaches have proved to be reliable tools for the selection of novel targets and therapeutic ligands. Molecular docking is a key tool in computer-assisted drug design and development. Docking has been utilized to perform virtual screening on large libraries of compounds, and propose structural hypotheses of how the ligands bind with the target with lead optimization. Another potential application of docking is optimization stages of the drug-discovery cycle. This review summarizes the known drug targets of AD, in vivo active agents against AD, state-of-the-art docking studies done in AD, and future prospects of the docking with particular emphasis on AD.