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1.
Biomolecules ; 14(5)2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38786006

RESUMO

Age is the primary risk factor for neurodegenerative diseases such as Alzheimer's and Huntington's disease. Alzheimer's disease is the most common form of dementia and a leading cause of death in the elderly population of the United States. No effective treatments for these diseases currently exist. Identifying effective treatments for Alzheimer's, Huntington's, and other neurodegenerative diseases is a major current focus of national scientific resources, and there is a critical need for novel therapeutic strategies. Here, we investigate the potential for targeting the kynurenine pathway metabolite 3-hydroxyanthranilic acid (3HAA) using Caenorhabditis elegans expressing amyloid-beta or a polyglutamine peptide in body wall muscle, modeling the proteotoxicity in Alzheimer's and Huntington's disease, respectively. We show that knocking down the enzyme that degrades 3HAA, 3HAA dioxygenase (HAAO), delays the age-associated paralysis in both models. This effect on paralysis was independent of the protein aggregation in the polyglutamine model. We also show that the mechanism of protection against proteotoxicity from HAAO knockdown is mimicked by 3HAA supplementation, supporting elevated 3HAA as the mediating event linking HAAO knockdown to delayed paralysis. This work demonstrates the potential for 3HAA as a targeted therapeutic in neurodegenerative disease, though the mechanism is yet to be explored.


Assuntos
Ácido 3-Hidroxiantranílico , Peptídeos beta-Amiloides , Caenorhabditis elegans , Paralisia , Peptídeos , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Animais , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/genética , Peptídeos/farmacologia , Ácido 3-Hidroxiantranílico/metabolismo , Paralisia/induzido quimicamente , Paralisia/metabolismo , Paralisia/genética , Modelos Animais de Doenças , Doença de Alzheimer/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/tratamento farmacológico , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Doença de Huntington/metabolismo , Doença de Huntington/genética , Dioxigenases/metabolismo , Dioxigenases/genética
2.
Geroscience ; 46(2): 2571-2581, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38103095

RESUMO

The ability to quantify aging-related changes in histological samples is important, as it allows for evaluation of interventions intended to effect health span. We used a machine learning architecture that can be trained to detect and quantify these changes in the mouse kidney. Using additional held out data, we show validation of our model, correlation with scores given by pathologists using the Geropathology Research Network aging grading scheme, and its application in providing reproducible and quantifiable age scores for histological samples. Aging quantification also provides the insights into possible changes in image appearance that are independent of specific geropathology-specified lesions. Furthermore, we provide trained classifiers for H&E-stained slides, as well as tutorials on how to use these and how to create additional classifiers for other histological stains and tissues using our architecture. This architecture and combined resources allow for the high throughput quantification of mouse aging studies in general and specifically applicable to kidney tissues.


Assuntos
Envelhecimento , Aprendizado de Máquina , Camundongos , Animais , Envelhecimento/patologia , Rim
3.
Nat Commun ; 14(1): 8338, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097593

RESUMO

Tryptophan metabolism through the kynurenine pathway influences molecular processes critical to healthy aging including immune signaling, redox homeostasis, and energy production. Aberrant kynurenine metabolism occurs during normal aging and is implicated in many age-associated pathologies including chronic inflammation, atherosclerosis, neurodegeneration, and cancer. We and others previously identified three kynurenine pathway genes-tdo-2, kynu-1, and acsd-1-for which decreasing expression extends lifespan in invertebrates. Here we report that knockdown of haao-1, a fourth gene encoding the enzyme 3-hydroxyanthranilic acid (3HAA) dioxygenase (HAAO), extends lifespan by ~30% and delays age-associated health decline in Caenorhabditis elegans. Lifespan extension is mediated by increased physiological levels of the HAAO substrate 3HAA. 3HAA increases oxidative stress resistance and activates the Nrf2/SKN-1 oxidative stress response. In pilot studies, female Haao knockout mice or aging wild type male mice fed 3HAA supplemented diet were also long-lived. HAAO and 3HAA represent potential therapeutic targets for aging and age-associated disease.


Assuntos
Proteínas de Caenorhabditis elegans , Cinurenina , Animais , Masculino , Feminino , Camundongos , Cinurenina/metabolismo , Triptofano/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Ácido 3-Hidroxiantranílico/metabolismo , Longevidade/genética , Camundongos Knockout , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo
4.
bioRxiv ; 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37461572

RESUMO

The ability to quantify aging-related changes in histological samples is important, as it allows for evaluation of interventions intended to effect health span. We used a machine learning architecture that can be trained to detect and quantify these changes in the mouse kidney. Using additional held out data, we show validation of our model, correlation with scores given by pathologists using the Geropathology Research Network aging grading scheme, and its application in providing reproducible and quantifiable age scores for histological samples. Aging quantification also provides the insights into possible changes in image appearance that are independent of specific geropathology-specified lesions. Furthermore, we provide trained classifiers for H&E-stained slides, as well as tutorials on how to use these and how to create additional classifiers for other histological stains and tissues using our architecture.This architecture and combined resources allow for the high throughput quantification of mouse aging studies in general and specifically applicable to kidney tissues.

5.
Hosp Top ; 100(2): 69-76, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34470597

RESUMO

The 2019 SARS-CoV2 virus presented a capacity demand scenario for Yale New Haven Hospital. The response was created with a focus on clinical needs, but was also driven by the unique characteristics of the buildings within our institution. These physical characteristics were considered in the response as a safety measure as little was known about the transmissibility risk in the acute hospital setting of SARS-CoV2 at the time of response. The lessons learned in capacity expansion to meet the potentially catastrophic demand for acute care services due to a novel, poorly understood pathogen are discussed here.


Assuntos
COVID-19 , Hospitais , Humanos , Pacientes Internados , Pandemias/prevenção & controle , RNA Viral , SARS-CoV-2
6.
J Am Soc Nephrol ; 32(8): 1961-1973, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34045313

RESUMO

BACKGROUND: Mutations in COL4A5 are responsible for 80% of cases of X-linked Alport Syndrome (XLAS). Although genes that cause AS are well characterized, people with AS who have similar genetic mutations present with a wide variation in the extent of kidney impairment and age of onset, suggesting the activities of modifier genes. METHODS: We created a cohort of genetically diverse XLAS male and female mice using the Diversity Outbred mouse resource and measured albuminuria, GFR, and gene expression. Using a quantitative trait locus approach, we mapped modifier genes that can best explain the underlying phenotypic variation measured in our diverse population. RESULTS: Genetic analysis identified several loci associated with the variation in albuminuria and GFR, including a locus on the X chromosome associated with X inactivation and a locus on chromosome 2 containing Fmn1. Subsequent analysis of genetically reduced Fmn1 expression in Col4a5 knockout mice showed a decrease in albuminuria, podocyte effacement, and podocyte protrusions in the glomerular basement membrane, which support the candidacy of Fmn1 as a modifier gene for AS. CONCLUSION: With this novel approach, we emulated the variability in the severity of kidney phenotypes found in human patients with Alport Syndrome through albuminuria and GFR measurements. This approach can identify modifier genes in kidney disease that can be used as novel therapeutic targets.


Assuntos
Albuminúria/urina , Colágeno Tipo IV/genética , Creatinina/urina , Forminas/genética , Nefrite Hereditária/genética , Albuminúria/etiologia , Animais , Mapeamento Cromossômico , Modelos Animais de Doenças , Feminino , Forminas/ultraestrutura , Expressão Gênica , Taxa de Filtração Glomerular , Masculino , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Mutação , Nefrite Hereditária/complicações , Nefrite Hereditária/fisiopatologia , Fenótipo , Podócitos/patologia , Estudo de Prova de Conceito , Locos de Características Quantitativas , RNA-Seq , Fatores Sexuais , Sequenciamento Completo do Genoma
7.
J Am Soc Nephrol ; 32(1): 52-68, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33154175

RESUMO

BACKGROUND: Nephropathologic analyses provide important outcomes-related data in experiments with the animal models that are essential for understanding kidney disease pathophysiology. Precision medicine increases the demand for quantitative, unbiased, reproducible, and efficient histopathologic analyses, which will require novel high-throughput tools. A deep learning technique, the convolutional neural network, is increasingly applied in pathology because of its high performance in tasks like histology segmentation. METHODS: We investigated use of a convolutional neural network architecture for accurate segmentation of periodic acid-Schiff-stained kidney tissue from healthy mice and five murine disease models and from other species used in preclinical research. We trained the convolutional neural network to segment six major renal structures: glomerular tuft, glomerulus including Bowman's capsule, tubules, arteries, arterial lumina, and veins. To achieve high accuracy, we performed a large number of expert-based annotations, 72,722 in total. RESULTS: Multiclass segmentation performance was very high in all disease models. The convolutional neural network allowed high-throughput and large-scale, quantitative and comparative analyses of various models. In disease models, computational feature extraction revealed interstitial expansion, tubular dilation and atrophy, and glomerular size variability. Validation showed a high correlation of findings with current standard morphometric analysis. The convolutional neural network also showed high performance in other species used in research-including rats, pigs, bears, and marmosets-as well as in humans, providing a translational bridge between preclinical and clinical studies. CONCLUSIONS: We developed a deep learning algorithm for accurate multiclass segmentation of digital whole-slide images of periodic acid-Schiff-stained kidneys from various species and renal disease models. This enables reproducible quantitative histopathologic analyses in preclinical models that also might be applicable to clinical studies.


Assuntos
Aprendizado Profundo , Diagnóstico por Computador , Rim/fisiopatologia , Reconhecimento Automatizado de Padrão , Algoritmos , Animais , Modelos Animais de Doenças , Processamento de Imagem Assistida por Computador/métodos , Nefropatias/patologia , Glomérulos Renais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Redes Neurais de Computação , Ácido Periódico/química , Reprodutibilidade dos Testes , Bases de Schiff , Pesquisa Translacional Biomédica
8.
Sci Rep ; 9(1): 12287, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31444371

RESUMO

Uromodulin is a zona pellucida-type protein essentially produced in the thick ascending limb (TAL) of the mammalian kidney. It is the most abundant protein in normal urine. Defective uromodulin processing is associated with various kidney disorders. The luminal release and subsequent polymerization of uromodulin depend on its cleavage mediated by the serine protease hepsin. The biological relevance of a proper cleavage of uromodulin remains unknown. Here we combined in vivo testing on hepsin-deficient mice, ex vivo analyses on isolated tubules and in vitro studies on TAL cells to demonstrate that hepsin influence on uromodulin processing is an important modulator of salt transport via the sodium cotransporter NKCC2 in the TAL. At baseline, hepsin-deficient mice accumulate uromodulin, along with hyperactivated NKCC2, resulting in a positive sodium balance and a better adaptation to water deprivation. In conditions of high salt intake, defective uromodulin processing predisposes hepsin-deficient mice to a salt-wasting phenotype, with a decreased salt sensitivity. These modifications are associated with intracellular accumulation of uromodulin, endoplasmic reticulum-stress and signs of tubular damage. These studies expand the physiological role of hepsin and uromodulin and highlight the importance of hepsin-mediated processing of uromodulin for kidney tubule homeostasis and salt sensitivity.


Assuntos
Homeostase , Túbulos Renais/metabolismo , Serina Endopeptidases/metabolismo , Cloreto de Sódio/farmacologia , Uromodulina/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Homeostase/efeitos dos fármacos , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/patologia , Camundongos Endogâmicos C57BL , Mutação/genética , Fenótipo , Serina Endopeptidases/genética , Membro 1 da Família 12 de Carreador de Soluto/metabolismo , Uromodulina/urina
9.
Am J Pathol ; 189(9): 1786-1796, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31220455

RESUMO

With the advent and increased accessibility of deep neural networks (DNNs), complex properties of histologic images can be rigorously and reproducibly quantified. We used DNN-based transfer learning to analyze histologic images of periodic acid-Schiff-stained renal sections from a cohort of mice with different genotypes. We demonstrate that DNN-based machine learning has strong generalization performance on multiple histologic image processing tasks. The neural network extracted quantitative image features and used them as classifiers to look for differences between mice of different genotypes. Excellent performance was observed at segmenting glomeruli from non-glomerular structure and subsequently predicting the genotype of the animal on the basis of glomerular quantitative image features. The DNN-based genotype classifications highly correlate with mesangial matrix expansion scored by a pathologist (R.E.C.), which differed in these animals. In addition, by analyzing non-glomeruli images, the neural network identified novel histologic features that differed by genotype, including the presence of vacuoles, nuclear count, and proximal tubule brush border integrity, which was validated with immunohistologic staining. These features were not identified in systematic pathologic examination. Our study demonstrates the power of DNNs to extract biologically relevant phenotypes and serve as a platform for discovering novel phenotypes. These results highlight the synergistic possibilities for pathologists and DNNs to radically scale up our ability to generate novel mechanistic hypotheses in disease.


Assuntos
Aldeído Oxirredutases/fisiologia , Processamento de Imagem Assistida por Computador/métodos , Rim/fisiopatologia , Redes Neurais de Computação , Vias Neurais , Animais , Masculino , Camundongos , Camundongos Knockout , Fenótipo
10.
DNA Res ; 26(1): 37-44, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30395234

RESUMO

The prevalence of chronic kidney disease (CKD) is rising worldwide and 10-15% of the global population currently suffers from CKD and its complications. Given the increasing prevalence of CKD there is an urgent need to find novel treatment options. The American black bear (Ursus americanus) copes with months of lowered kidney function and metabolism during hibernation without the devastating effects on metabolism and other consequences observed in humans. In a biomimetic approach to better understand kidney adaptations and physiology in hibernating black bears, we established a high-quality genome assembly. Subsequent RNA-Seq analysis of kidneys comparing gene expression profiles in black bears entering (late fall) and emerging (early spring) from hibernation identified 169 protein-coding genes that were differentially expressed. Of these, 101 genes were downregulated and 68 genes were upregulated after hibernation. Fold changes ranged from 1.8-fold downregulation (RTN4RL2) to 2.4-fold upregulation (CISH). Most notable was the upregulation of cytokine suppression genes (SOCS2, CISH, and SERPINC1) and the lack of increased expression of cytokines and genes involved in inflammation. The identification of these differences in gene expression in the black bear kidney may provide new insights in the prevention and treatment of CKD.


Assuntos
Regulação da Expressão Gênica , Genoma , Hibernação/genética , Ursidae/genética , Animais , Feminino , Perfilação da Expressão Gênica , Masculino , Receptor Nogo 2/genética , Estações do Ano , Análise de Sequência de DNA , Análise de Sequência de RNA , Proteínas Supressoras da Sinalização de Citocina/genética , Ursidae/fisiologia
11.
Am J Physiol Renal Physiol ; 315(6): F1644-F1651, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30256126

RESUMO

Current methods of scoring histological kidney samples, specifically glomeruli, do not allow for collection of quantitative data in a high-throughput and consistent manner. Neither untrained individuals nor computers are presently capable of identifying glomerular features, so expert pathologists must do the identification and score using a categorical matrix, complicating statistical analysis. Critical information regarding overall health and physiology is encoded in these samples. Rapid comprehensive histological scoring could be used, in combination with other physiological measures, to significantly advance renal research. Therefore, we used machine learning to develop a high-throughput method to automatically identify and collect quantitative data from glomeruli. Our method requires minimal human interaction between steps and provides quantifiable data independent of user bias. The method uses free existing software and is usable without extensive image analysis training. Validation of the classifier and feature scores in mice is highlighted in this work and shows the power of applying this method in murine research. Preliminary results indicate that the method can be applied to data sets from different species after training on relevant data, allowing for fast glomerular identification and quantitative measurements of glomerular features. Validation of the classifier and feature scores are highlighted in this work and show the power of applying this method. The resulting data are free from user bias. Continuous data, such that statistical analysis can be performed, allows for more precise and comprehensive interrogation of samples. These data can then be combined with other physiological data to broaden our overall understanding of renal function.


Assuntos
Diagnóstico por Computador/métodos , Interpretação de Imagem Assistida por Computador/métodos , Nefropatias/patologia , Glomérulos Renais/patologia , Aprendizado de Máquina , Microscopia/métodos , Reconhecimento Automatizado de Padrão/métodos , Animais , Automação Laboratorial , Biópsia , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , Valor Preditivo dos Testes , Ratos , Reprodutibilidade dos Testes , Software , Especificidade da Espécie , Fluxo de Trabalho
12.
Physiol Genomics ; 50(8): 543-552, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29652635

RESUMO

Mesangial matrix expansion is an important process in the initiation of chronic kidney disease, yet the genetic factors driving its development are unknown. Our previous studies have implicated Far2 as a candidate gene associated with differences in mesangial matrix expansion between mouse inbred strains. Consistent with the hypothesis that increased expression of Far2 leads to mesangial matrix expansion through increased production of platelet-activating factor precursors, we show that FAR2 is capable of mediating de novo platelet-activating factor synthesis in vitro and driven by the transcription factor NKX3.2. We demonstrate that knockdown of Far2 in mice delays the progression of mesangial matrix expansion with at least six months (equivalent to ~15 yr in human). Furthermore, we show that increased FAR2 expression in human patients is associated with diabetic nephropathy, lupus nephritis, and IgA nephropathy. Taken together, these results highlight FAR2's role in the development of mesangial matrix expansion and chronic kidney disease.


Assuntos
Aldeído Oxirredutases/genética , Nefropatias Diabéticas/genética , Mesângio Glomerular/metabolismo , Adulto , Idoso , Aldeído Oxirredutases/metabolismo , Animais , Nefropatias Diabéticas/metabolismo , Feminino , Mesângio Glomerular/patologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Adulto Jovem
13.
PLoS One ; 12(12): e0189485, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29244860

RESUMO

Glycogen synthase kinase 3 (GSK3) plays an important role in the development of diabetes mellitus and renal injury. GSK3 inhibition increases glucose uptake in insulin-insensitive muscle and adipose tissue, while it reduces albuminuria and glomerulosclerosis in acute kidney injury. The effect of chronic GSK3 inhibition in diabetic nephropathy is not known. We tested the effect of lithium, the only clinical GSK3 inhibitor, on the development of diabetes mellitus and kidney injury in a mouse model of diabetic nephropathy. Twelve-week old female BTBR-ob/ob mice were treated for 12 weeks with 0, 10 and 40 mmol LiCl/kg after which the development of diabetes and diabetic nephropathy were analysed. In comparison to BTBR-WT mice, ob/ob mice demonstrated elevated bodyweight, increased blood glucose/insulin levels, urinary albumin and immunoglobulin G levels, glomerulosclerosis, reduced nephrin abundance and a damaged proximal tubule brush border. The lithium-10 and -40 diets did not affect body weight and resulted in blood lithium levels of respectively <0.25 mM and 0.48 mM. The Li-40 diet fully rescued the elevated non-fasting blood glucose levels. Importantly, glomerular filtration rate was not affected by lithium, while urine albumin and immunoglobulin G content were further elevated. While lithium did not worsen the glomerulosclerosis, proximal tubule function seemed affected by lithium, as urinary NGAL levels were significantly increased. These results demonstrate that lithium attenuates non-fasting blood glucose levels in diabetic mice, but aggravates urinary albumin and immunoglobulin G content, possibly resulting from proximal tubule dysfunction.


Assuntos
Albuminúria/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Hipoglicemiantes/farmacologia , Cloreto de Lítio/farmacologia , Albuminúria/etiologia , Animais , Glicemia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/sangue , Avaliação Pré-Clínica de Medicamentos , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Hipoglicemiantes/uso terapêutico , Rim/efeitos dos fármacos , Rim/enzimologia , Rim/patologia , Cloreto de Lítio/uso terapêutico , Camundongos Obesos
14.
Hum Mol Genet ; 26(19): 3722-3735, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28934385

RESUMO

Mutations of the human ATP6V1B1 gene cause distal renal tubular acidosis (dRTA; OMIM #267300) often associated with sensorineural hearing impairment; however, mice with a knockout mutation of Atp6v1b1 were reported to exhibit a compensated acidosis and normal hearing. We discovered a new spontaneous mutation (vortex, symbol vtx) of Atp6v1b1 in an MRL/MpJ (MRL) colony of mice. In contrast to the reported phenotype of the knockout mouse, which was developed on a primarily C57BL/6 (B6) strain background, MRL-Atp6v1b1vtx/vtx mutant mice exhibit profound hearing impairment, which is associated with enlarged endolymphatic compartments of the inner ear. Mutant mice have alkaline urine but do not exhibit overt metabolic acidosis, a renal phenotype similar to that of the Atpbv1b1 knockout mouse. The abnormal inner ear phenotype of MRL- Atp6v1b1vtx/vtx mice was lost when the mutation was transferred onto the C57BL/6J (B6) background, indicating the influence of strain-specific genetic modifiers. To genetically map modifier loci in Atp6v1b1vtx/vtx mice, we analysed ABR thresholds of progeny from a backcross segregating MRL and B6 alleles. We found statistically significant linkage with a locus on Chr 13 that accounts for about 20% of the hearing threshold variation in the backcross mice. The important effect that genetic background has on the inner ear phenotype of Atp6v1b1 mutant mice provides insight into the hearing loss variability associated with dRTA caused by ATP6V1B1 mutations. Because MRL-Atp6v1b1vxt/vtx mice do not recapitulate the metabolic acidosis of dRTA patients, they provide a new genetic model for nonsyndromic deafness with enlarged vestibular aqueduct (EVA; OMIM #600791).


Assuntos
Surdez/genética , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo , Acidose/genética , Acidose/metabolismo , Acidose Tubular Renal/genética , Acidose Tubular Renal/metabolismo , Animais , Surdez/metabolismo , Modelos Animais de Doenças , Orelha Interna/patologia , Feminino , Ligação Genética , Perda Auditiva/genética , Perda Auditiva/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Fenótipo , Aqueduto Vestibular/metabolismo , Aqueduto Vestibular/fisiologia
15.
Aging Cell ; 16(4): 672-682, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28401650

RESUMO

We report a systematic RNAi longevity screen of 82 Caenorhabditis elegans genes selected based on orthology to human genes differentially expressed with age. We find substantial enrichment in genes for which knockdown increased lifespan. This enrichment is markedly higher than published genomewide longevity screens in C. elegans and similar to screens that preselected candidates based on longevity-correlated metrics (e.g., stress resistance). Of the 50 genes that affected lifespan, 46 were previously unreported. The five genes with the greatest impact on lifespan (>20% extension) encode the enzyme kynureninase (kynu-1), a neuronal leucine-rich repeat protein (iglr-1), a tetraspanin (tsp-3), a regulator of calcineurin (rcan-1), and a voltage-gated calcium channel subunit (unc-36). Knockdown of each gene extended healthspan without impairing reproduction. kynu-1(RNAi) alone delayed pathology in C. elegans models of Alzheimer's disease and Huntington's disease. Each gene displayed a distinct pattern of interaction with known aging pathways. In the context of published work, kynu-1, tsp-3, and rcan-1 are of particular interest for immediate follow-up. kynu-1 is an understudied member of the kynurenine metabolic pathway with a mechanistically distinct impact on lifespan. Our data suggest that tsp-3 is a novel modulator of hypoxic signaling and rcan-1 is a context-specific calcineurin regulator. Our results validate C. elegans as a comparative tool for prioritizing human candidate aging genes, confirm age-associated gene expression data as valuable source of novel longevity determinants, and prioritize select genes for mechanistic follow-up.


Assuntos
Caenorhabditis elegans/genética , Regulação da Expressão Gênica no Desenvolvimento , Genoma , Longevidade/genética , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/antagonistas & inibidores , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Ontologia Genética , Estudo de Associação Genômica Ampla , Humanos , Hidrolases/antagonistas & inibidores , Hidrolases/genética , Hidrolases/metabolismo , Proteínas de Repetições Ricas em Leucina , Anotação de Sequência Molecular , Proteínas Musculares/antagonistas & inibidores , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Proteínas/antagonistas & inibidores , Proteínas/genética , Proteínas/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Tetraspaninas/antagonistas & inibidores , Tetraspaninas/genética , Tetraspaninas/metabolismo
16.
J Am Soc Nephrol ; 27(11): 3271-3277, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27020856

RESUMO

Changes in metabolite levels of the kynurenine pathway have been observed in patients with CKD, suggesting involvement of this pathway in disease pathogenesis. Our recent genetic analysis in the mouse identified the kynurenine 3-mono-oxygenase (KMO) gene (Kmo) as a candidate gene associated with albuminuria. This study investigated this association in more detail. We compared KMO abundance in the glomeruli of mice and humans under normal and diabetic conditions, observing a decrease in glomerular KMO expression with diabetes. Knockdown of kmo expression in zebrafish and genetic deletion of Kmo in mice each led to a proteinuria phenotype. We observed pronounced podocyte foot process effacement on long stretches of the filtration barrier in the zebrafish knockdown model and mild podocyte foot process effacement in the mouse model, whereas all other structures within the kidney remained unremarkable. These data establish the candidacy of KMO as a causal factor for changes in the kidney leading to proteinuria and indicate a functional role for KMO and metabolites of the tryptophan pathway in podocytes.


Assuntos
Deleção de Genes , Quinurenina 3-Mono-Oxigenase/genética , Proteinúria/enzimologia , Proteinúria/genética , Animais , Feminino , Humanos , Quinurenina 3-Mono-Oxigenase/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peixe-Zebra
17.
Curr Protoc Mouse Biol ; 5(2): 95-133, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26069080

RESUMO

Despite the dramatic increase in human lifespan over the past century, there remains pronounced variability in "health-span," or the period of time in which one is generally healthy and free of disease. Much of the variability in health-span and lifespan is thought to be genetic in origin. Understanding the genetic mechanisms of aging and identifying ways to boost longevity is a primary goal in aging research. Here, we describe a pipeline of phenotypic assays for assessing mouse models of aging. This pipeline includes behavior/cognition testing, body composition analysis, and tests of kidney function, hematopoiesis, and immune function, as well as physical parameters. We also describe study design methods for assessing lifespan and health-span, and other important considerations when conducting aging research in the laboratory mouse. The tools and assays provided can assist researchers with understanding the correlative relationships between age-associated phenotypes and, ultimately, the role of specific genes in the aging process.


Assuntos
Envelhecimento , Modelos Animais de Doenças , Ciência dos Animais de Laboratório/métodos , Camundongos , Envelhecimento/fisiologia , Envelhecimento/psicologia , Estruturas Animais/fisiologia , Animais , Comportamento Animal , Humanos , Longevidade , Camundongos/genética , Camundongos/fisiologia , Projetos de Pesquisa
18.
Invest New Drugs ; 33(1): 128-37, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25248753

RESUMO

BACKGROUND: Ganetespib (STA-9090) is an Hsp90 inhibitor that downregulates VEGFR, c-MET, HER2, IGF-IR, EGFR, and other Hsp90 client proteins involved in hepatocarcinogenesis, thereby making it an attractive therapy for HCC. This Phase I study was performed to establish the safety, tolerability, recommended Phase 2 dose (RP2D), and preliminary clinical activity of ganetespib in previously treated patients with advanced HCC. METHODS: Patients with advanced HCC, Child-Pugh A cirrhosis, progression on or intolerance to sorafenib, and ECOG PS ≤ 1 were enrolled in a standard 3x3 dose escalation study at doses of 100 mg/m(2), 150 mg/m(2), and 200 mg/m(2) IV given on days 1, 8, and 15 of each 28-day cycle. Objective response by RECIST version 1.1 criteria was evaluated by CT/MRI every 8 weeks. RESULTS: Fourteen patients were enrolled in this trial and received at least one dose of the study drug. Of the 14 patients: median age, 57 years old; male 71 %; Asian 36 %; HCC etiology (HBV 36 %, HCV 43 %, Hemachromatosis 7 %, unknown 21 %); Child Pugh Class (A 93 %, B 7 %); median number of prior treatments 2; median baseline AFP 70.1 ng/mL. The RP2D was determined to be 200 mg/m(2). The most commonly seen AEs were diarrhea (93 %), fatigue (71 %), AST elevation (64 %), and hyperglycemia (64 %). The most common Gr 3/4 AEs were hyperglycemia (21 %) and lipasemia (21 %). One (7 %) patient had a fatal AE, septic shock, within 30 days of receiving the study drug. One dose-limiting toxicity, grade 3 lipasemia, was observed at the 100 mg/m(2) dose. Pharmacokinetics studies showed a t1/2, CL, Tmax, and Vss of 6.45 h, 48.28 L/h (25.56 L/h/m(2)), 0.76 h, and 191 L (100.4 L/m(2)), respectively. No objective responses were seen; one patient (7 %) had stable disease at 16 weeks. Median time to progression was 1.8 months, and median overall survival was 7.2 months. CONCLUSION: Ganetespib had a manageable safety profile in patients with advanced HCC who had progressed on at least one line of systemic therapy. The pharmacokinetic profile showed that ganetespib exposure in patients with mild hepatic dysfunction is similar to that seen in patients with normal liver function. Ganetespib showed limited clinical benefit in patients with advanced HCC in this phase I trial.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Neoplasias Hepáticas/tratamento farmacológico , Triazóis/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/metabolismo , Feminino , Humanos , Fígado/metabolismo , Hepatopatias/metabolismo , Neoplasias Hepáticas/metabolismo , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Triazóis/efeitos adversos , Triazóis/sangue , Triazóis/farmacocinética
19.
J Am Soc Nephrol ; 24(12): 1995-2001, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24009241

RESUMO

Aging of the kidney is associated with renal damage, in particular mesangial matrix expansion (MME). Identifying the genes involved in this process will help to unravel the mechanisms of aging and aid in the design of novel therapeutic modalities aimed at prevention and regression. In this study, structural changes in glomeruli of 24 inbred mouse strains were characterized in male mice at 6, 12, and 20 months of age. Haplotype association mapping was used to determine genetic loci associated with the presence of MME at 20 months. This analysis identified a significant association with a 200-kb haplotype block on chromosome 6 containing Far2. Sequencing revealed that mouse strains with MME contain a 9-bp sequence in the 5' untranslated region of Far2 that is absent in most of the strains without MME. Real-time PCR showed a two-fold increase in the expression of Far2 in the kidneys of strains with the insert, and subsequent experiments performed in vitro with luciferase reporter vectors showed that this sequence difference causes differential expression of Far2. Overexpression of Far2 in a mouse mesangial cell line induced upregulation of platelet activating factor and the fibrotic marker TGF-ß. This upregulation of MME-promoting factors may result, in part, from the FAR2-catalyzed reduction of fatty acyl-coenzyme A to fatty alcohols, which are possible precursors of platelet activating factor. Overall, these data suggest the identification of a novel pathway involved in renal aging that may yield therapeutic targets for reducing MME.


Assuntos
Envelhecimento/patologia , Aldeído Oxirredutases/genética , Glomérulos Renais/patologia , Glomérulos Renais/fisiologia , Células Mesangiais/patologia , Células Mesangiais/fisiologia , Envelhecimento/fisiologia , Animais , Mapeamento Cromossômico , Haplótipos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Endogâmicos MRL lpr , Camundongos Endogâmicos NOD , Especificidade da Espécie
20.
Clin Cancer Res ; 19(6): 1557-66, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23362324

RESUMO

PURPOSE: We conducted a single-arm phase II study of cediranib, a pan-VEGFR tyrosine kinase inhibitor, in patients with advanced hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: Patients with histologically confirmed measurable advanced HCC and adequate hematologic, hepatic, and renal functions received cediranib 30-mg orally once daily (4 weeks/cycle). The primary endpoint was progression-free survival (PFS) rate at 3 months. Other endpoints included response rates, overall survival (OS), pharmacokinetics (PK), and biomarkers for cediranib. RESULTS: Cediranib treatment resulted in an estimated 3-month PFS rate of 77% (60%, 99%). Median PFS was 5.3 (3.5,9.7) months, stable disease was seen in 5/17 patients (29%), and median OS was 11.7 (7.5-13.6) months. Grade 3 toxicities included hypertension (29%), hyponatremia (29%), and hyperbilirubinemia (18%). Cediranib PK were comparable to those seen in cancer patients with normal hepatic function. Plasma levels of VEGF and PlGF increased and sVEGFR1, sVEGFR2, and Ang-2 decreased after cediranib treatment. PFS was inversely correlated with baseline levels of VEGF, sVEGFR2, and bFGF and with on-treatment levels of bFGF and IGF-1, and directly associated with on-treatment levels of IFN-γ. OS was inversely correlated with baseline levels of sVEGFR1, Ang-2, TNF-α, CAIX, and CD34(+)CD133(+)CD45(dim) circulating progenitor cells and on-treatment levels of sVEGFR2. CONCLUSIONS: Despite the limitations of primary endpoint selection, cediranib at 30-mg daily showed a high incidence of toxicity and preliminary evidence of antitumor activity in advanced HCC. Hepatic dysfunction did not seem to affect the steady-state PK of cediranib. Exploratory studies suggested proangiogenic and inflammatory factors as potential biomarkers of anti-VEGF therapy in HCC.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Quinazolinas/administração & dosagem , Idoso , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/biossíntese , Estadiamento de Neoplasias , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacocinética , Quinazolinas/efeitos adversos , Quinazolinas/farmacocinética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores
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