RESUMO
Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease. Despite intensive research, considerable information on NAFLD development remains elusive. In this study, we examined the effects of vitamin D on age-induced NAFLD, especially in connection with mitochondrial abnormalities. We observed the prevention of NAFLD in 22-month-old C57BL/6 mice fed a vitamin D3-supplemented (20,000 IU/kg) diet compared with mice fed a control (1000 IU/kg) diet. We evaluated whether vitamin D3 supplementation enhanced mitochondrial functions. We found that the level of mitochondrial contact site and cristae organizing system (MICOS) 60 (Mic60) level was reduced in aged mice, and this reduction was specifically restored by vitamin D3. In addition, depletion of Immt, the human gene encoding the Mic60 protein, induced changes in gene expression patterns that led to fat accumulation in both HepG2 and primary hepatocytes, and these alterations were effectively prevented by vitamin D3. In addition, silencing of the vitamin D receptor (VDR) decreased the Mic60 levels, which were recovered by vitamin D treatment. To assess whether VDR directly regulates Mic60 levels, we performed chromatin immunoprecipitation and reporter gene analysis. We discovered that VDR directly binds to the Immt 5' promoter region spanning positions -3157 to -2323 and thereby upregulates Mic60. Our study provides the first demonstration that a reduction in Mic60 levels due to aging may be one of the mechanisms underlying the development of aging-associated NAFLD. In addition, vitamin D3 could positively regulate Mic60 expression, and this may be one of the important mechanisms by which vitamin D could ameliorate age-induced NAFLD.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Animais , Camundongos , Lactente , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Vitamina D/farmacologia , Vitamina D/uso terapêutico , Vitamina D/metabolismo , Membranas Associadas à Mitocôndria , Camundongos Endogâmicos C57BL , Membranas Mitocondriais/metabolismoRESUMO
Background: Bariatric surgery (BS) has a superior effect on reducing body weight and fat in patients with morbid obesity. As a result, BS mitigates obesity-related complications such as type 2 diabetes (T2D). However, few studies have shown the mechanism underlying diabetes remission after surgery. This study aimed to investigate the differences in serum hormone and inflammatory cytokine levels related to diabetes before surgery and during 12 months of follow-up in Korean patients with obesity. Methods: The study participants were patients with morbid obesity (n=63) who underwent sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) between 2016 - 2017 at seven tertiary hospitals in Korea. The patients were followed for 1 year after surgery. Results: Sixty-three patients had significant weight loss after surgery and showed improvements in clinical parameters and hormonal and inflammatory profiles. Among them, 23 patients who were diabetic preoperatively showed different remission after surgery. The levels of inflammation-related clinical parameters changed significantly in the remission group, and serum inflammatory cytokine and hormones significantly decreased at certain points and showed an overall decreasing trend. Conclusions: Our study found postoperative changes of factors in blood samples, and the changes in hormones secreted from the three major metabolic tissue (pancreas, adipose, and gut) along with the differences in multi-origin inflammatory cytokines between remission and non-remission groups provide a path for understanding how the effect of BS in improving glucose metabolism is mediated.
RESUMO
BACKGROUND: Glutamate is a major neurotransmitter, although it causes cytotoxicity and inflammation in nonneuronal organs. This study aimed to investigate the metabolic disorders in which glutamate, associated with type 2 diabetes onset, is induced in the liver. METHODS: An analysis of Korean community-based Ansan-Ansung cohort study data as well as functional research using in vitro and mouse models were performed. RESULTS: Groups with high plasma glutamate levels (T2, T3) had a significantly increased risk of diabetes incidence after 8 years, compared to the group with relatively low glutamate levels (T1). Analysis of the effect of glutamate on diabetes onset in vitro showed that glutamate induces insulin resistance by increasing glucose-related protein 78 (GRP78) and phosphoenolpyruvate carboxykinase (PEPCK) expression in SK-Hep-1 human liver cells. In addition, three different genes, FRMB4B, PLG, and PARD3, were significantly associated with glutamate and were identified via genome-wide association studies. Among glutamate-related genes, plasminogen (PLG) levels were most significantly increased in several environments in which insulin resistance was induced, and was also upregulated by glutamate. Glutamate-induced increase in PLG in liver cells was caused by metabotropic glutamate receptor 5 activation, and PLG levels were also upregulated after extracellular secretion. Moreover, glutamate increased the expression of plasminogen activator inhibitor-1 (PAI-1). Thus, extracellular secreted PLG cannot be converted to plasmin (fibrinolytic enzyme) by increased PAI-1. CONCLUSIONS: Increased glutamate is closely associated with the development of diabetes, and it may cause metabolic disorders by inhibiting the fibrinolytic system, which plays an important role in determining blood clots, a hallmark of diabetes.
Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Camundongos , Animais , Humanos , Plasminogênio/genética , Plasminogênio/metabolismo , Inibidor 1 de Ativador de Plasminogênio , Ácido Glutâmico , Diabetes Mellitus Tipo 2/genética , Resistência à Insulina/genética , Estudos de Coortes , Estudo de Associação Genômica Ampla , República da Coreia/epidemiologiaRESUMO
Alcohol consumption is associated with a high increased lipid profile and this association may depend on genetic risk factors. In this study, we aimed to assess the effects of genetic variation associated with alcohol consumption on lipid profiles using data from two Korean population studies. We performed a genotype association study using the HEXA (n = 51,349) and KNHANES (n = 9158) data. Genotype analyses of the two sets of Korean population data showed associations of increased total cholesterol and high-density lipoprotein (HDL)-cholesterol with CETP rs708272. The HEXA and KNHANES populations revealed differences in HDL cholesterol according to the presence of CETP rs708272, independent of ALDH2 rs671 and alcohol consumption. In contrast, total cholesterol levels were associated with alcohol consumption and ALDH2 rs671 in men with CETP rs708272 (CT and TT genotypes). Furthermore, in drinkers with ALDH2 rs671 (GA and AA genotypes), higher total cholesterol was associated with the CETP rs708272 TT minor homozygous genotype based on both HEXA and KNHANES data. Our findings demonstrated that alcohol consumption and genetic variation in either CETP or ALDH2 may be associated with cholesterol levels. We hope these findings will provide a better understanding of the relationship between alcohol consumption and cholesterol according to each individual's genetic background.
Assuntos
Consumo de Bebidas Alcoólicas , Polimorfismo Genético , Consumo de Bebidas Alcoólicas/genética , Aldeído-Desidrogenase Mitocondrial/genética , Colesterol , Proteínas de Transferência de Ésteres de Colesterol/genética , HDL-Colesterol/genética , Genótipo , Humanos , MasculinoRESUMO
Excessive alcohol intake is an important cause of major public health problem in East Asian countries. Growing evidence suggests that genetic factors are associated with alcohol consumption and the risk for alcohol-associated disease, and these factors contribute to the risk of developing chronic diseases, including diabetes. This study aims to investigate the association of type 2 diabetes with genetic polymorphisms within HECTD4 based on alcohol exposure. We performed a genome-wide association study involving the cohorts of the KoGES-HEXA study (n = 50,028) and Ansan and Ansung study (n = 7,980), both of which are prospective cohort studies in Korea. The top three single-nucleotide polymorphisms (SNPs) of the HECTD4 gene, specifically rs77768175, rs2074356 and rs11066280, were found to be significantly associated with alcohol consumption. We found that individuals carrying the variant allele in these SNPs had lower fasting blood glucose, triglyceride, and GGT levels than those with the wild-type allele. Multiple logistic regression showed that statistically significant associations of HECTD4 gene polymorphisms with an increased risk of type 2 diabetes were found in drinkers. Namely, these SNPs were associated with decreased odds of diabetes in the presence of alcohol consumption. As a result of examining the effect of alcohol on the expression of the HECTD4 gene, ethanol increased the expression of HECTD4 in cells, but the level was decreased by NAC treatment. Similar results were obtained from liver samples of mice treated with alcohol. Moreover, a loss of HECTD4 resulted in reduced levels of CYP2E1 and lipogenic gene expression in ethanol-treated cells, while the level of ALDH2 expression increased, indicating a reduction in ethanol-induced hepatotoxicity.
Assuntos
Diabetes Mellitus Tipo 2 , Consumo de Bebidas Alcoólicas/efeitos adversos , Aldeído-Desidrogenase Mitocondrial/genética , Animais , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Etanol , Jejum , Estudo de Associação Genômica Ampla , Glucose , Humanos , Camundongos , Polimorfismo de Nucleotídeo Único , Prevalência , Estudos Prospectivos , Triglicerídeos , Ubiquitina-Proteína Ligases/genéticaRESUMO
Long QT syndrome type 2 (LQT2) is a heart disorder caused by a loss-of-function mutation in the KCNH2 gene that is an essential factor in cardiac repolarization and affects the heart rate. This study has generated a human-induced stem cell line (KSCBi014-A) carrying the KCNH2 (c.453delC) mutation from an LQT2 patient. The non-integrative Sendai virus-mediated induced pluripotent stem cell (iPSC) reprogramming method was used for iPSC line generation. The KSCBi014-A line maintained stem cell-like morphology, normal karyotype, and pluripotency, and could differentiate into three germ layers in vitro.
RESUMO
Human pluripotent stem cells (hPSCs) have promising therapeutic applications due to their infinite capacity for self-renewal and pluripotency. Genomic stability is imperative for the clinical use of hPSCs; however, copy number variation (CNV), especially recurrent CNV at 20q11.21, may contribute genomic instability of hPSCs. Furthermore, the effects of CNVs in hPSCs at the whole-transcriptome scale are poorly understood. This study aimed to examine the functional in vivo and in vitro effects of frequently detected CNVs at 20q11.21 during early-stage differentiation of hPSCs. Comprehensive transcriptome profiling of abnormal hPSCs revealed that the differential gene expression patterns had a negative effect on differentiation potential. Transcriptional heterogeneity identified by single-cell RNA sequencing (scRNA-seq) of embryoid bodies from two different isogenic lines of hPSCs revealed alterations in differentiated cell distributions compared with that of normal cells. RNA-seq analysis of 22 teratomas identified several differentially expressed lineage-specific markers in hPSCs with CNVs, consistent with the histological results of the altered ecto/meso/endodermal ratio due to CNVs. Our results suggest that CNV amplification contributes to cell proliferation, apoptosis, and cell fate specification. This work shows the functional consequences of recurrent genetic abnormalities and thereby provides evidence to support the development of cell-based applications.
Assuntos
Biomarcadores Tumorais/genética , Diferenciação Celular , Aberrações Cromossômicas , Cromossomos Humanos Par 20/genética , Variações do Número de Cópias de DNA , Células-Tronco Pluripotentes/patologia , Teratoma/patologia , Animais , Biomarcadores Tumorais/metabolismo , Células Cultivadas , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células-Tronco Pluripotentes/metabolismo , Análise de Sequência de RNA , Teratoma/genética , Teratoma/metabolismo , TranscriptomaRESUMO
Pluripotent stem cell-derived cerebral organoids have the potential to recapitulate the pathophysiology of in vivo human brain tissue, constituting a valuable resource for modelling brain disorders, including infectious diseases. Toxoplasma gondii, an intracellular protozoan parasite, infects most warm-blooded animals, including humans, causing toxoplasmosis. In immunodeficient patients and pregnant women, infection often results in severe central nervous system disease and fetal miscarriage. However, understanding the molecular pathophysiology of the disease has been challenging due to limited in vitro model systems. Here, we developed a new in vitro model system of T. gondii infection using human brain organoids. We observed that tachyzoites can infect human cerebral organoids and are transformed to bradyzoites and replicate in parasitophorous vacuoles to form cysts, indicating that the T. gondii asexual life cycle is efficiently simulated in the brain organoids. Transcriptomic analysis of T. gondii-infected organoids revealed the activation of the type I interferon immune response against infection. In addition, in brain organoids, T. gondii exhibited a changed transcriptome related to protozoan invasion and replication. This study shows cerebral organoids as physiologically relevant in vitro model systems useful for advancing the understanding of T. gondii infections and host interactions.
Assuntos
Encéfalo/parasitologia , Interferon Tipo I/genética , Organoides/parasitologia , Toxoplasma/fisiologia , Animais , Encéfalo/citologia , Encéfalo/imunologia , Linhagem Celular , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Técnicas de Cultura de Órgãos , Organoides/citologia , Organoides/imunologia , Toxoplasma/patogenicidade , ToxoplasmoseRESUMO
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by the loss of paternally expressed genes in an imprinted region of chromosome 15q11.2-q13. We generated a human-induced pluripotent stem cell line, designated KSCBi009-A, from peripheral blood mononuclear cells of a 13-year-old male PWS patient exhibiting deletion of the paternal chromosome 15q11.2-q13 region. The deletion was confirmed via methylation-specific multiplex ligation probe amplification assay (MS-MLPA) of genomic DNA. The hiPSC line expressed pluripotency markers and differentiated into three germ layers. The cell line may serve as a valuable model of an imprinting PWS disorder useful in terms of drug discovery and development.
Assuntos
Células-Tronco Pluripotentes Induzidas , Síndrome de Prader-Willi , Adolescente , Cromossomos , Cromossomos Humanos Par 15/genética , Metilação de DNA/genética , Impressão Genômica , Humanos , Leucócitos Mononucleares , Masculino , Síndrome de Prader-Willi/genéticaRESUMO
Although human induced pluripotent stem cell (hiPSC) lines are karyotypically normal, they retain the potential for mutation in the genome. Accordingly, intensive and relevant quality controls for clinical-grade hiPSCs remain imperative. As a conceptual approach, we performed RNA-seq-based broad-range genetic quality tests on GMP-compliant human leucocyte antigen (HLA)-homozygous hiPSCs and their derivatives under postdistribution conditions to investigate whether sequencing data could provide a basis for future quality control. We found differences in the degree of single-nucleotide polymorphism (SNP) occurring in cells cultured at three collaborating institutes. However, the cells cultured at each centre showed similar trends, in which more SNPs occurred in late-passage hiPSCs than in early-passage hiPSCs after differentiation. In eSNP karyotyping analysis, none of the predicted copy number variations (CNVs) were identified, which confirmed the results of SNP chip-based CNV analysis. HLA genotyping analysis revealed that each cell line was homozygous for HLA-A, HLA-B, and DRB1 and heterozygous for HLA-DPB type. Gene expression profiling showed a similar differentiation ability of early- and late-passage hiPSCs into cardiomyocyte-like, hepatic-like, and neuronal cell types. However, time-course analysis identified five clusters showing different patterns of gene expression, which were mainly related to the immune response. In conclusion, RNA-seq analysis appears to offer an informative genetic quality testing approach for such cell types and allows the early screening of candidate hiPSC seed stocks for clinical use by facilitating safety and potential risk evaluation.
Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular , Reprogramação Celular/genética , Reprogramação Celular/fisiologia , Variações do Número de Cópias de DNA/genética , Genótipo , Teste de Histocompatibilidade , Homozigoto , Humanos , Cariotipagem , RNA-Seq , Transcriptoma/genéticaRESUMO
Leber congenital amaurosis (LCA) is an inherited retinal dystrophy that is characterized by severe visual impairment in early infancy. We generated a human induced pluripotent stem cell (hiPSC) line, DKHi090-A, from peripheral blood mononuclear cells (PBMCs) of a patient with LCA, by using a Sendai virus-based gene delivery system. We confirmed that DKHi090-A has a nicotinamide mononucleotide adenyltransferase 1 (NMNAT1) mutation and normal karyotype. DKHi090-A line is pluripotent and is capable of multilineage differentiation. This cell line is registered and is available at the National Stem Cell Bank, Korea National Institute of Health.
Assuntos
Células-Tronco Pluripotentes Induzidas/metabolismo , Amaurose Congênita de Leber/genética , Animais , Feminino , Humanos , LactenteRESUMO
Assessment of differentiation potential is a basic requirement to obtain qualified human pluripotent stem cells (hPSCs). Here, we report a simple differentiation method using fetal bovine serum (FBS) to estimate differentiation potential and propensity of hPSCs. PluriTest using RNA-sequencing showed that cells differentiated after treatment with 5% FBS. Expression patterns of three germ layer markers revealed that cells cultured in Knockout Serum Replacement-containing medium (KSR) with mouse feeder cells had higher differentiation potential than cells cultured in a chemically defined medium (E8) with recombinant matrix proteins, especially into the mesoderm and endoderm lineages. Analysis of differentially expressed genes between KSR and E8 identified DUSP6 as a marker for where cells had been cultured. Expression of DUSP6 correlated with FGF-ERK signaling activity. Fine-tuning of FGF-ERK signaling activity to a range that can shut down DUSP6 transcription but sustain NANOG transcription partially increased the differentiation potential. Our data suggest that differentiation with 5% FBS is good to estimate differentiation potential and propensity at the early stage, and that DUSP6 is an excellent marker to monitor ERK signaling activity.
Assuntos
Diferenciação Celular , Fosfatase 6 de Especificidade Dupla/análise , Sistema de Sinalização das MAP Quinases , Células-Tronco Pluripotentes/metabolismo , Soro , Animais , Biomarcadores/análise , Técnicas de Cultura de Células/métodos , Meios de Cultura/farmacologia , Células Alimentadoras , Fatores de Crescimento de Fibroblastos/metabolismo , Humanos , Camundongos , Células-Tronco Pluripotentes/citologiaRESUMO
PDX1 plays a crucial role in the development and maintenance of ß-cells and directly regulates pancreatic ß-cell-specific transcription factors by binding to the insulin gene. Here, we introduced an EGFP reporter into the C-terminus of PDX1 in KSCBi005-A human induced pluripotent stem cells through homologous recombination using CRISPR/Cas9 nuclease. The cells had a normal karyotype, expressed several pluripotency markers, and maintained their differentiation potential. KSCBi005-A-3 cells can be used to monitor PDX1 expression in live cells during ß-cell differentiation; the cell line has been registered at the National Stem Cell Bank, Korea National Institute of Health.
Assuntos
Sistemas CRISPR-Cas/genética , Técnicas de Cultura de Células/métodos , Linhagem Celular/citologia , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Homeodomínio/genética , Transativadores/genética , Sequência de Bases , Humanos , MasculinoRESUMO
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by loss of paternally expressed genes in an imprinted region of 15q11.2-q13. We established a human-induced pluripotent stem cell (hiPSC) line, KSCBi007-A, from the peripheral blood mononuclear cells of a 5-month-old girl with PWS that retained maternal uniparental disomy (UPD). Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) of genomic DNA revealed the maternal UPD in the hiPSCs. The generated hiPSC line expressed pluripotency markers and showed the ability to differentiate into three germ layers in vitro. This hiPSC line could be used as a cellular model of an imprinting disorder in humans.
Assuntos
Células-Tronco Pluripotentes Induzidas/patologia , Síndrome de Prader-Willi/patologia , Dissomia Uniparental/patologia , Linhagem Celular , Feminino , Humanos , Lactente , Reprodutibilidade dos TestesRESUMO
Senior-Loken syndrome (SLS) is a rare disorder primarily associated with kidney and retinal dysfunction. We generated a human induced pluripotency stem cell (hiPSC) line, designated DKHi005-A, from peripheral blood mononuclear cells of a patient with SLS using a Sendai virus reprogramming method. We confirmed that DKHi005-A cells harbor the same mutation as the patient and show a normal karyotype. DKHi005-A also has pluripotency and the capacity for differentiation into the three germ layers. This cell line is registered and available at the National Stem Cell Bank, Korea National Institute of Health.
Assuntos
Técnicas de Cultura de Células/métodos , Ciliopatias/sangue , Ciliopatias/patologia , Células-Tronco Pluripotentes Induzidas/patologia , Doenças Renais Císticas/sangue , Doenças Renais Císticas/patologia , Amaurose Congênita de Leber/sangue , Amaurose Congênita de Leber/patologia , Leucócitos Mononucleares/patologia , Atrofias Ópticas Hereditárias/sangue , Atrofias Ópticas Hereditárias/patologia , Sequência de Bases , Linhagem Celular , Criança , Feminino , HumanosRESUMO
Osteogenesis imperfecta (OI) is a genetic disorder characterized by brittle bones. OI type I is the most common and usually the mildest form. We generated human induced pluripotent stem cells (hiPSCs), KSCBi006-A, from the peripheral blood mononuclear cells of a patient with OI type I using the Sendai virus delivery method. The generated hiPSCs retained the disease-causing DNA mutation (COL1A1, c.3162delT) and showed a normal karyotype. KSCBi006-A also has pluripotency and the capacity for differentiation into the three germ layers. These patient-specific iPSCs provide a valuable cellular modeling platform for OI and a resource for drug screening.
Assuntos
Técnicas de Cultura de Células/métodos , Linhagem Celular/patologia , Colágeno Tipo I/genética , Células-Tronco Pluripotentes Induzidas/patologia , Mutação/genética , Osteogênese Imperfeita/genética , Osteogênese Imperfeita/patologia , Sequência de Bases , Criança , Cadeia alfa 1 do Colágeno Tipo I , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
NESTIN, an intermediate filament, is a neuroectodermal marker involved in induced pluripotent stem cell (iPSC) differentiation toward neural lineages. Here, we introduced an EGFP reporter into the C-terminus of NESTIN in KSCBi005-A hiPSCs through homologous recombination using CRISPR/Cas9 nuclease. The successfully edited line was confirmed by sequencing and had a normal karyotype. It expressed EGFP upon induction of neural differentiation and exhibited potential for differentiation into three germ layers. KSCBi005-A-1 cells could be used to monitor the expression of NESTIN in differentiated cell types. This cell line is available at the National Stem Cell Bank, Korea National Institute of Health.
Assuntos
Linhagem Celular/metabolismo , Proteínas de Fluorescência Verde/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Nestina/genética , Sistemas CRISPR-Cas , Diferenciação Celular , Linhagem Celular/citologia , Genes Reporter , Proteínas de Fluorescência Verde/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Masculino , Nestina/metabolismoRESUMO
We generated a human induced pluripotent stem cell (hiPSC) line, KSCBi003-A, from adipose tissue-derived mesenchymal stem cells (Ad-MSCs) using a Sendai virus-based gene delivery system. We confirmed that the KSCBi003-A has a normal karyotype and short tandem repeat (STR)-based identities that match the parent cells. We also confirmed that the cell line expresses pluripotent stem cell markers such as Nanog, OCT4, SSEA-4, TRA-1-60, and TRA-1-81. We also analyzed that the KSCBi003-A has an ability to differentiate three germ layers (ectoderm, mesoderm, endoderm). This cell line is registered and available at the National Stem Cell Bank, Korea National Institute of Health.
Assuntos
Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Mesenquimais/metabolismo , Diferenciação Celular , HumanosRESUMO
We generated human induced pluripotent stem cells (KSCBi002-B and KSCBi002-B-1) from the dermal fibroblasts of a donor using a modified RNA-based gene delivery method. According to GTG-banding analysis, the generated KSCBi002-B line has a cytogenetic abnormality (46,XY, t(1;4)(q21;q25)) that is distinct from that of the donor, whereas KSCBi002-B-1 has a normal karyotype (46,XY). These cell lines can be useful as a model for characterizing the hiPSCs generated by a non-viral and non-integrative system, or as a chromosomal balanced translocation model. These two cell lines are registered and available from the National Stem Cell Bank, Korea National Institute of Health.