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1.
Qual Life Res ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743313

RESUMO

PURPOSE: To examine associations between Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales and PedsQL Infant Scales with formal health care resource utilization (HCRU) and informal caregiver burden. METHODS: We studied a pediatric cohort of 837 patients (median age: 8.4 years) with suspected genetic disorders enrolled January 2019 through July 2021 in the NYCKidSeq program for diagnostic sequencing. Using linked ~ nine-month longitudinal survey and physician claims data collected through May 2022, we modeled the association between baseline PedsQL scores and post-baseline HCRU (median follow-up: 21.1 months) and informal care. We also assessed the longitudinal change in PedsQL scores with physician services using linear mixed-effects models. RESULTS: Lower PedsQL total and physical health scores were independently associated with increases in 18-month physician services, encounters, and weekly informal care. Comparing low vs. median total scores, increases were 10.6 services (95% CI: 1.0-24.6), 3.3 encounters (95% CI: 0.5-6.8), and $668 (95% CI: $350-965), respectively. For the psychosocial domain, higher scores were associated with decreased informal care. Based on adjusted linear mixed-effects modeling, every additional ten physician services was associated with diminished improvement in longitudinal PedsQL total score trajectories by 1.1 point (95% confidence interval: 0.6-1.6) on average. Similar trends were observed in the physical and psychosocial domains. CONCLUSION: PedsQL scores were independently associated with higher utilization of physician services and informal care. Moreover, longitudinal trajectories of PedsQL scores became less favorable with increased physician services. Adding PedsQL survey instruments to conventional measures for improved risk stratification should be evaluated in further research.


The Pediatric Quality of Life Inventory (PedsQL) is widely used to measure health-related quality of life in pediatric patients; however, few studies have examined whether the PedsQL is indicative of longitudinal outcomes of morbidity and health care needs. This study captures associations between PedsQL scores with utilization of physician and informal care in children with suspected genetic disorders. We demonstrate that lower PedsQL total and physical health scores are independently associated with greater utilization of physician services and informal care. Moreover, longitudinal trajectories of PedsQL scores become less favorable with increased physician services. Results can inform future applications of PedsQL instruments.

2.
Genet Med ; 26(1): 101011, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37897232

RESUMO

PURPOSE: To better understand the effects of returning diagnostic sequencing results on clinical actions and economic outcomes for pediatric patients with suspected genetic disorders. METHODS: Longitudinal physician claims data after diagnostic sequencing were obtained for patients aged 0 to 21 years with neurologic, cardiac, and immunologic disorders with suspected genetic etiology. We assessed specialist consultation rates prompted by primary diagnostic results, as well as marginal effects on overall 18-month physician services and costs. RESULTS: We included data on 857 patients (median age: 9.6 years) with a median follow-up of 17.3 months after disclosure of diagnostic sequencing results. The likelihood of having ≥1 recommendation for specialist consultation in 155 patients with positive findings was high (72%) vs 23% in 443 patients with uncertain findings and 21% in 259 patients with negative findings (P < .001). Follow-through consultation occurred in 30%. Increases in 18-month physician services and costs following a positive finding diminished after multivariable adjustment. Also, no significant differences between those with uncertain and negative findings were demonstrated. CONCLUSION: Our study did not provide evidence for significant increases in downstream physician services and costs after returning positive or uncertain diagnostic sequencing findings. More large-scale longitudinal studies are needed to confirm these findings.


Assuntos
Revelação , Médicos , Humanos , Criança , Custos e Análise de Custo
4.
Curr Genet ; 69(4-6): 235-249, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37347284

RESUMO

Eukaryotic DNA replication is accompanied by the disassembly and reassembly of nucleosomes and the transmission of epigenetic marks to the newly assembled chromatids. Several histone chaperones, including CAF-1 and Asf1p, are central to these processes. On the other hand, replication forks pause at numerous positions throughout the genome, but it is not known if and how this pausing affects the reassembly and maintenance of chromatin structures. Here, we applied drug-free gene silencing assays to analyze the genetic interactions between CAC1, ASF1, and two genes that regulate the stability of the paused replisome (TOF1) and the resumption of elongation (RRM3). Our results show that TOF1 and RRM3 differentially interact with CAF-1 and ASF1 and that the deletions of TOF1 and RRM3 lead to reduced silencing and increased frequency of epigenetic conversions at three loci in the genome of S. cerevisiae. Our study adds details to the known activities of CAF-1 and Asf1p and suggests that the pausing of the replication fork can lead to epigenetic instability.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , DNA Helicases/genética , Replicação do DNA/genética , Inativação Gênica
5.
Biochem Cell Biol ; 101(1): 125-130, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36661263

RESUMO

Multiple studies in Saccharomyces cerevisiae have measured the levels of gene silencing by inserting the URA3 gene at various loci and selecting against URA3-expressing cells by 5-flouroorotic acid (5-FOA). However, 5-FOA affects the cellular pools of dNTPs and can produce side effects. To circumvent this issue, we and others have introduced drug-free techniques to detect silent and active gene states. In this study, we compared three drug-free methods based on the expression of fluorescent reporters in the VIIL telomere of S. cerevisiae. Our results point out that only one of these methods is suitable for large-scale drug-free analyses of gene silencing.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Inativação Gênica , Regulação Fúngica da Expressão Gênica
6.
bioRxiv ; 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36415456

RESUMO

Proteases play key roles in viral replication cycles. They can provide cleavage maturation of viral glycoproteins, processing of viral polyproteins, or disassembly of viral capsids. Thus, proteases constitute ideal targets for antiviral intervention â€" pharmaceutically, by small molecule inhibitors, or naturally, by host immune responses. Indeed, we and others have shown that individual members of the Serine protease inhibitor (SERPIN) family have specific antiviral function by blocking proteolytic steps inherent to viral replication cycles. Whether additional members of the large SERPIN family possess antiviral activity and whether SERPINs function as part of the antiviral cell-intrinsic immune response, is currently unknown. Here, we found that specific SERPINs are produced upon infection with clinically relevant respiratory viruses in vitro and in vivo , and in concert with classical interferon-stimulated genes. We next developed a structure-based in silico screen to uncover non-canonical SERPIN-protease pairs. We identified several SERPINs with potential antiviral function, including: SERPINE1 targeting cathepsin L, required for SARS-CoV-2 entry; SERPINB8 targeting furin, required for glycoprotein maturation cleavage of numerous viruses; and SERPINB2 targeting adenovirus protease, which suggests the first direct-acting antiviral SERPIN. Our study demonstrates how proteolysis is modulated for antiviral defense and how this process could inform antiviral targets against clinically relevant respiratory pathogens.

8.
EMBO Rep ; 23(12): e55218, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36256515

RESUMO

Co-opting host cell protein synthesis is a hallmark of many virus infections. In response, certain host defense proteins limit mRNA translation globally, albeit at the cost of the host cell's own protein synthesis. Here, we describe an interferon-stimulated helicase, DDX60, that decreases translation from viral internal ribosome entry sites (IRESs). DDX60 acts selectively on type II IRESs of encephalomyocarditis virus (EMCV) and foot and mouth disease virus (FMDV), but not by other IRES types or by 5' cap. Correspondingly, DDX60 reduces EMCV and FMDV (type II IRES) replication, but not that of poliovirus or bovine enterovirus 1 (BEV-1; type I IRES). Furthermore, replacing the IRES of poliovirus with a type II IRES is sufficient for DDX60 to inhibit viral replication. Finally, DDX60 selectively modulates the amount of translating ribosomes on viral and in vitro transcribed type II IRES mRNAs, but not 5' capped mRNA. Our study identifies a novel facet in the repertoire of interferon-stimulated effector genes, the selective downregulation of translation from viral type II IRES elements.


Assuntos
Interferons , Sítios Internos de Entrada Ribossomal
9.
Expert Opin Biol Ther ; 22(3): 385-395, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34806498

RESUMO

INTRODUCTION: Human epidermal growth factor receptor 2 (HER2)-positive breast cancers account for approximately 15 to 20% of breast cancer diagnoses. Historically, HER2-positive breast cancers had been associated with poorer prognosis. The addition of HER2-targeted agents to treatment regimens has significantly improved outcomes for patients with HER2-positive breast cancer. Despite this, relapses continue to occur in about 20% of patients. Newer therapeutic strategies are needed. The role of immunotherapy in the treatment of HER2-positive breast cancer is currently under clinical investigation. AREAS COVERED: This article will focus on the clinical trial data evaluating immune checkpoint inhibitors, including pembrolizumab, atezolizumab, avelumab, durvalumab, and nivolumab in the treatment of HER2-positive breast cancer. EXPERT OPINION: The incorporation of immunotherapy in the treatment of HER2-positive breast cancer is a reasonable strategy. Clinical trials of checkpoint inhibitors with HER2-targeted agents show clinical activity in HER2-positive breast cancer tumors that are programmed cell death-ligand 1 (PD-L1) positive and also when used as an earlier line of therapy in the metastatic setting. Treatment of HER2-positive breast cancer with immunotherapy and HER2-targeted agents warrants continued clinical investigation.


Assuntos
Neoplasias da Mama , Inibidores de Checkpoint Imunológico , Neoplasias da Mama/metabolismo , Feminino , Humanos , Imunoterapia , Recidiva Local de Neoplasia/tratamento farmacológico , Receptor ErbB-2
10.
Clin Lymphoma Myeloma Leuk ; 21(3): 188-198.e2, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33339769

RESUMO

BACKGROUND: We evaluated time to thromboembolism (TE) and risk factors in multiple myeloma (MM) patients after first exposure to immunomodulatory therapy, stratified by thromboprophylaxis. PATIENTS AND METHODS: We retrospectively analyzed adult MM patients who received immunomodulatory therapy with or without dexamethasone between February 2012 and October 2017. Thromboprophylaxis included aspirin, anticoagulants (low-molecular-weight heparin, direct oral anticoagulants, or warfarin), or none. Primary endpoint was time to on-treatment TE by thromboprophylaxis type. Time to TE using death as a competing risk censored at 12 months was used in univariate and multivariable analyses to identify risk factors. RESULTS: Of 485 evaluable patients, 57% were white and 36% African American; median age was 66. Most received lenalidomide (97.5%) and dexamethasone (90%). Half presented with ≥ 1 comorbidities. Sixty-nine had no documented receipt of prophylaxis, 357 aspirin, and 59 anticoagulation. More patients receiving anticoagulants had ≥ 1 comorbidities compared to aspirin or no-prophylaxis groups (P < .001). There was no difference in 12-month estimated cumulative incidence of TE (7.3%; 95% confidence interval, 5.2-9.9) between thromboprophylaxis groups (none 4.4%, aspirin 8.5%, anticoagulant 3.4%) (P = .24). In multivariable analyses, male sex (hazard ratio, 2.50; 95% confidence interval, 1.21-5.17; P = .014) and presence of any comorbidity (hazard ratio, 2.35; 95% confidence interval, 1.17-4.73; P = .016) were associated with TE incidence; thromboprophylaxis type was not (P = .12). CONCLUSION: Male sex and presence of any comorbidity were associated with time to TE. There were no differences in TE incidence between thromboprophylaxis groups despite a higher proportion of those in the anticoagulant group having ≥ 1 comorbidities.


Assuntos
Antineoplásicos Imunológicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Mieloma Múltiplo/complicações , Mieloma Múltiplo/epidemiologia , Tromboembolia/epidemiologia , Tromboembolia/etiologia , Antineoplásicos Imunológicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores , Tomada de Decisão Clínica , Comorbidade , Gerenciamento Clínico , Suscetibilidade a Doenças , Humanos , Incidência , Mieloma Múltiplo/tratamento farmacológico , Medição de Risco , Fatores de Risco , Tromboembolia/diagnóstico , Tromboembolia/prevenção & controle , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia
11.
Insects ; 9(4)2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30463305

RESUMO

We use climatic conditions that are associated with known monarch butterfly overwintering groves in California to build a Maxent model, and focus on the fine scale probability of overwintering grove occurrence in a topographically complex region of the state (Santa Barbara County). Grove locations are known from recent and historical surveys and a long-term citizen science database. The climatic niche model performs well, predicting that overwintering habitat is most likely to occur along the coast and at low elevations, as shown by empirical data. We then use climatic variables in conjunction with climate change scenarios to model the future location of overwintering habitat, and find a substantial shift in the predicted distribution. Under a plausible scenario, the probability of occurrence of overwintering habitat directly reflects elevation, with coastal regions having a reduced probability relative to today, and higher elevation sites increasing in probability. Under a more extreme scenario, high probability sites are only located along ridgelines and in mountaintop regions of the county. This predicted shift in distribution is likely to have management implications, as sites that currently lack monarchs may become critical to conservation in the future. Our results suggest that estimating the size of the western overwintering population in the future will be problematic, unless annual counts compensate for a shift in the distribution and a potential change in the number and location of occupied sites.

13.
Bioanalysis ; 8(18): 1919-36, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27523799

RESUMO

AIM: Selumetinib is an inhibitor of MEK1/2 in Phase III development that has activity in multiple tumor types. Validated bioanalytical methods were required to quantitate selumetinib and its N-desmethyl and amide metabolites in a variety of human biological matrices. Methodology & results: LC-MS/MS assays were developed and validated that demonstrated acceptable precision, accuracy and selectivity for selumetinib and the two metabolites in human plasma, urine, blood dialysate and plasma ultrafiltrate. Incurred sample re-analysis was acceptable and issues observed in plasma with the amide metabolite, due to potential instability, were addressed. CONCLUSION: Robust and sensitive LC-MS/MS assays for the quantification of selumetinib and two of its metabolites were validated in human biological matrices and are being used to support the clinical development program.


Assuntos
Benzimidazóis/sangue , Benzimidazóis/urina , Inibidores de Proteínas Quinases/sangue , Inibidores de Proteínas Quinases/urina , Espectrometria de Massas em Tandem/métodos , Amidas/sangue , Amidas/metabolismo , Amidas/urina , Benzimidazóis/metabolismo , Cromatografia Líquida/métodos , Monitoramento de Medicamentos/métodos , Humanos , Limite de Detecção , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 2/antagonistas & inibidores , Inibidores de Proteínas Quinases/metabolismo
14.
Mil Med ; 179(8): 865-78, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25102529

RESUMO

Mental health problems pose challenges for military veterans, returning service members, and military family members including spouses and children. Challenges to meeting mental health needs include improving access to care and improving quality of care. Mobile Health, or "mHealth," can help meet these needs in the garrison and civilian environments. mHealth brings unique capabilities to health care provision through the use of mobile device technologies. This report identifies high-priority mHealth technology development considerations in two categories. First, priority considerations specific to mental health care provision include safety, privacy, evidence-based practice, efficacy studies, and temperament. Second, priority considerations broadly applicable to mHealth include security, outcomes, ease of use, carrier compliance, hardware, provider perspectives, data volume, population, regulation, command policy, and reimbursement. Strategic planning for the advancement of these priority considerations should be coordinated with stated Department of Defense capability needs to maximize likelihood of adoption. This report also summarizes three leading, military programs focused on mHealth projects in mental health, The Telemedicine and Advanced Technology Research Center, The Military Operational Medicine Research Program, United States Army Medical Research and Materiel Command, and The National Center for Telehealth and Technology.


Assuntos
Computadores de Mão , Acessibilidade aos Serviços de Saúde , Serviços de Saúde Mental , Militares/psicologia , Telemedicina , Veteranos/psicologia , Segurança Computacional , Humanos , Aplicativos Móveis , Segurança do Paciente , Privacidade , Estados Unidos
15.
Nat Prod Commun ; 8(8): 1059-64, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24079166

RESUMO

Four steroidal alkaloids extracted from the roots and rhizomes of Veratrum californicum were separated by high performance liquid chromatography (HPLC) and identified using high resolution electrospray ionization time of flight tandem mass spectrometry (ESI-TOF-MS/MS) as veratrosine, cycloposine, veratramine, and cyclopamine. This paper compares ethanol and benzene as extraction solvents, HPLC solvent conditions leading to good separation of steroidal alkaloids, and MS/MS fragmentation patterns for the four steroidal alkaloids which have been released to the public database MassBank.jp. The reported Soxhlet extraction method nearly triples the recovery of steroidal alkaloids from V. californicum.


Assuntos
Alcaloides de Veratrum/isolamento & purificação , Veratrum/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Alcaloides de Veratrum/química
16.
Toxicol Sci ; 122(1): 64-72, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21527774

RESUMO

Electrophile-mediated post-translational modifications (PTMs) are known to cause tissue toxicities and disease progression. These effects are mediated via site-specific modifications and structural disruptions associated with such modifications. 1,4-Benzoquinone (BQ) and its quinone-thioether metabolites are electrophiles that elicit their toxicity via protein arylation and the generation of reactive oxygen species. Site-specific BQ-lysine adducts are found on residues in cytochrome c that are necessary for protein-protein interactions, and these adducts contribute to interferences in its ability to facilitate apoptosome formation. To further characterize the structural and functional impact of these BQ-mediated PTMs, the original mixture of BQ-adducted cytochrome c was fractionated by liquid isoelectric focusing to provide various fractions of BQ-adducted cytochrome c species devoid of the native protein. The fractionation process separates samples based on their isoelectric point (pI), and because BQ adducts form predominantly on lysine residues, increased numbers of BQ adducts on cytochrome c correlate with a lower protein pI. Each fraction was analyzed for structural changes, and each was also assayed for the ability to support apoptosome-mediated activation of caspase-3. Circular dichroism revealed that several of the BQ-adducted cytochrome c species maintained a slightly more rigid structure in comparison to native cytochrome c. BQ-adducted cytochrome c also failed to activate caspase-3, with increasing numbers of BQ-lysine adducts corresponding to a greater inability to activate the apoptosome. In summary, the specific site of the BQ-lysine adducts, and the nature of the adduct, are important determinants of the subsequent structural changes to cytochrome c. In particular, adducts at sites necessary for protein-protein interactions interfere with the proapoptotic function of cytochrome c.


Assuntos
Apoptossomas/efeitos dos fármacos , Apoptossomas/metabolismo , Benzoquinonas/toxicidade , Citocromos c/química , Adutos de DNA , Lisina/metabolismo , Animais , Benzoquinonas/química , Caspase 3/metabolismo , Cromatografia Líquida , Dicroísmo Circular/métodos , Cavalos , Focalização Isoelétrica/métodos , Modelos Moleculares , Conformação Proteica , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Estrutura Quaternária de Proteína , Espectrometria de Massas em Tandem
17.
Methods Mol Biol ; 691: 303-16, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20972761

RESUMO

Biological reactive intermediates can be created via metabolism of xenobiotics during the process of chemical elimination. They can also be formed as by-products of cellular metabolism, which produces reactive oxygen and nitrogen species. These reactive intermediates tend to be electrophilic in nature, which enables them to interact with tissue macromolecules, disrupting cellular signaling processes and often producing acute and chronic toxicities. Quinones are a well-known class of electrophilic species. Many natural products contain quinones as active constituents, and the quinone moiety exists in a number of chemotherapeutic agents. Quinones are also frequently formed as electrophilic metabolites from a variety of xeno- and endobiotics. Hydroquinone (HQ) is present in the environment from various sources, and it is also a known metabolite of benzene. HQ is converted in the body to 1,4-benzoquinone, which subsequently gives rise to hematotoxic and nephrotoxic quinone-thioether metabolites. The toxicity of these metabolites is dependent upon their ability to arylate proteins and to produce oxidative stress. Protein tertiary structure and protein amino acid sequence combine to determine which proteins are targets of these electrophilic quinone-thioether metabolites. We have used cytochrome c and model peptides to view adduction profiles of quinone-thioether metabolites, and have determined by MALDI-TOF analysis that these electrophiles target specific residues within these model systems.


Assuntos
Preparações Farmacêuticas/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Sequência de Aminoácidos , Animais , Bovinos , Hidroquinonas/metabolismo , Hidroquinonas/toxicidade , Peptídeos/química , Peptídeos/metabolismo , Proteínas/química , Especificidade por Substrato
18.
Methods Mol Biol ; 691: 317-26, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20972762

RESUMO

Biologically reactive intermediates are formed following metabolism of xenobiotics, and during normal oxidative metabolism. These reactive species are electrophilic in nature and are capable of forming stable adducts with target proteins. These covalent protein modifications can initiate processes that lead to acute tissue injury or chronic disease. Recent advancements in mass spectrometry techniques and data analysis has permitted a more detailed investigation of site-specific protein modifications by reactive electrophiles. Knowledge from such analyses will assist in providing a better understanding of how specific classes of electrophiles produce toxicity and disease progression via site-selective protein-specific covalent modification. Hydroquinone (HQ) is a known environmental toxicant, and its quinone-thioether metabolites, formed via the intermediate generation of 1,4-benzoquinone (1,4-BQ), elicit their toxic response via the covalent modification of target proteins and the generation of reactive oxygen species. We have utilized a model protein, cytochrome c, to guide us in identifying 1,4-BQ- and 1,4-BQ-thioether derived site-specific protein modifications. LC-MS/MS analyses reveals that these modifications occur selectively on lysine and glutamic acid residues of the target protein, and that these modifications occur within identifiable "electrophile binding motifs" within the protein. These motifs are found within lysine-rich regions of the protein and appear to be target sites of 1,4-BQ-thioether adduction. These residues also appear to dictate the nature of post-adduction chemistry and the final structure of the adduct. This model system will provide critical insight for in vivo adduct hunting following exposure to 1,4-BQ-thioethers, but the general approaches can also be extended to the identification of protein adducts derived from other classes of reactive electrophiles.


Assuntos
Cromatografia Líquida/métodos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas/metabolismo , Espectrometria de Massas em Tandem/métodos , Sequência de Aminoácidos , Animais , Benzoquinonas/química , Benzoquinonas/toxicidade , Sítios de Ligação , Citocromos c/química , Citocromos c/metabolismo , Dados de Sequência Molecular , Proteínas/química , Especificidade por Substrato , Xenobióticos/metabolismo , Xenobióticos/toxicidade
19.
Methods Mol Biol ; 691: 327-38, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20972763

RESUMO

The environmental toxicant hydroquinone (HQ) and its glutathione conjugates (GSHQs) cause renal cell necrosis via a combination of redox cycling and the covalent adduction of proteins within the S3 segment of the renal proximal tubules in the outer stripe of the outer medulla (OSOM). Following administration of 2-(glutathion-S-yl)HQ (MGHQ) (400 µmol/kg, i.v., 2 h) to Long Evans (wild-type Eker) rats, Western analysis utilizing an antibody specific for quinol-thioether metabolites of HQ revealed the presence of large amounts of chemical-protein adducts in both the OSOM and urine. By aligning the Western blot film with a parallel gel stained for protein, we can isolate the adducted proteins for LC-MS/MS analysis. Subsequent database searching can identify the specific site(s) of chemical adduction within these proteins. Finally, a combination of software programs can validate the identity of the adducted peptides. The site-specific identification of covalently adducted and oxidized proteins is a prerequisite for understanding the biological significance of chemical-induced posttranslational modifications (PTMs) and their toxicological significance.


Assuntos
Western Blotting/métodos , Cromatografia Líquida/métodos , Poluentes Ambientais/metabolismo , Hidroquinonas/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteinúria/metabolismo , Espectrometria de Massas em Tandem/métodos , Animais , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Poluentes Ambientais/toxicidade , Hidroquinonas/toxicidade , Ratos , Estatística como Assunto
20.
Methods Mol Biol ; 691: 339-47, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20972764

RESUMO

Recent technological advancements in mass spectrometry facilitate the detection of chemical-induced posttranslational modifications (PTMs) that may alter cell signaling pathways or alter the structure and function of the modified proteins. To identify such protein adducts (Kleiner et al., Chem Res Toxicol 11:1283-1290, 1998), multi-dimensional protein identification technology (MuDPIT) has been utilized. MuDPIT was first described by Link et al. as a new technique useful for protein identification from a complex mixture of proteins (Link et al., Nat Biotechnol 17:676-682, 1999). MuDPIT utilizes two different HPLC columns to further enhance peptide separation, increasing the number of peptide hits and protein coverage. The technology is extremely useful for proteomes, such as the urine proteome, samples from immunoprecipitations, and 1D gel bands resolved from a tissue homogenate or lysate. In particular, MuDPIT has enhanced the field of adduct hunting for adducted peptides, since it is more capable of identifying lesser abundant peptides, such as those that are adducted, than the more standard LC-MS/MS. The site-specific identification of covalently adducted proteins is a prerequisite for understanding the biological significance of chemical-induced PTMs and the subsequent toxicological response they elicit.


Assuntos
Cromatografia Líquida/métodos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteinúria/metabolismo , Espectrometria de Massas em Tandem/métodos , Animais , Bases de Dados de Proteínas , Hidroquinonas/metabolismo , Hidroquinonas/toxicidade , Ratos , Reprodutibilidade dos Testes , Estatística como Assunto
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