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1.
Nat Commun ; 15(1): 4385, 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38782906

RESUMEN

The parasite Toxoplasma gondii persists in its hosts by converting from replicating tachyzoites to latent bradyzoites housed in tissue cysts. The molecular mechanisms that mediate T. gondii differentiation remain poorly understood. Through a mutagenesis screen, we identified translation initiation factor eIF1.2 as a critical factor for T. gondii differentiation. A F97L mutation in eIF1.2 or the genetic ablation of eIF1.2 (∆eif1.2) markedly impeded bradyzoite cyst formation in vitro and in vivo. We demonstrated, at single-molecule level, that the eIF1.2 F97L mutation impacts the scanning process of the ribosome preinitiation complex on a model mRNA. RNA sequencing and ribosome profiling experiments unveiled that ∆eif1.2 parasites are defective in upregulating bradyzoite induction factors BFD1 and BFD2 during stress-induced differentiation. Forced expression of BFD1 or BFD2 significantly restored differentiation in ∆eif1.2 parasites. Together, our findings suggest that eIF1.2 functions by regulating the translation of key differentiation factors necessary to establish chronic toxoplasmosis.


Asunto(s)
Toxoplasma , Toxoplasma/metabolismo , Toxoplasma/genética , Animales , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/genética , Toxoplasmosis/parasitología , Toxoplasmosis/metabolismo , Ratones , Mutación , Ribosomas/metabolismo , Biosíntesis de Proteínas , Femenino , ARN Mensajero/metabolismo , ARN Mensajero/genética , Diferenciación Celular , Humanos
3.
bioRxiv ; 2023 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-37961607

RESUMEN

The parasite Toxoplasma gondii persists in its hosts by converting from replicating tachyzoites to latent bradyzoites housed in tissue cysts. The molecular mechanisms that mediate T. gondii differentiation remain poorly understood. Through a mutagenesis screen, we identified translation initiation factor eIF1.2 as a critical factor for T. gondii differentiation. A F97L mutation in eIF1.2 or the genetic ablation of eIF1.2 (Δ eIF1.2 ) markedly impeded bradyzoite cyst formation in vitro and in vivo . We demonstrated, at single-molecule level, that the eIF1.2 F97L mutation impacts the scanning process of the ribosome preinitiation complex on a model mRNA. RNA sequencing and ribosome profiling experiments unveiled that Δ eIF1.2 parasites are defective in the upregulating bradyzoite induction factors BFD1 and BFD2 during stress-induced differentiation. Forced expression of BFD1 or BFD2 significantly restored differentiation in Δ eIF1.2 parasites. Together, our findings suggest that eIF1.2 functions by regulating the translation of key differentiation factors necessary to establish chronic toxoplasmosis.

4.
Matern Child Health J ; 27(Suppl 1): 52-57, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37943395

RESUMEN

PURPOSE: Maternal substance use and deaths due to overdoses are increasing nationwide. Evidence suggests that the rate of resumed substance use, and fatal and non-fatal overdose is greatest in the first year after birth, particularly around six months postpartum, compared to other parts of the perinatal period. Doula care has been linked to improvements in perinatal health and outcomes. DESCRIPTION: In response to the opioid epidemic, the Philadelphia Department of Public Health developed and implemented the Doula Support Program (DSP), with a focus on one year of postpartum care for birthing people with a substance use disorder (SUD). In this paper, we describe the program and its formation and report on the early challenges and successes of the program implementation, based on information we received from program founders and managers in a group interview. ASSESSMENT: Early successes of the program include partnering with local community-based programs to recruit and retain doulas, supplementing traditional doula education with perinatal SUD-specific trainings, and maximizing client referrals by collaborating with local organizations and treatment centers that serve birthing people with SUD. Client retention, however, has proven to be challenging, especially during the COVID-19 pandemic. CONCLUSION: The DSP continues to grow, and lessons learned will facilitate program improvements. The goal of this paper is to outline the development and launch of the DSP and to act as a model for other state and local health departments interested in providing doula care for birthing people with SUD.


Asunto(s)
Doulas , Trastornos Relacionados con Sustancias , Embarazo , Femenino , Humanos , Pandemias , Philadelphia/epidemiología , Parto , Trastornos Relacionados con Sustancias/epidemiología
5.
EMBO J ; 42(23): e113155, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37886905

RESUMEN

Apicomplexan parasites discharge specialized organelles called rhoptries upon host cell contact to mediate invasion. The events that drive rhoptry discharge are poorly understood, yet essential to sustain the apicomplexan parasitic life cycle. Rhoptry discharge appears to depend on proteins secreted from another set of organelles called micronemes, which vary in function from allowing host cell binding to facilitation of gliding motility. Here we examine the function of the microneme protein CLAMP, which we previously found to be necessary for Toxoplasma gondii host cell invasion, and demonstrate its essential role in rhoptry discharge. CLAMP forms a distinct complex with two other microneme proteins, the invasion-associated SPATR, and a previously uncharacterized protein we name CLAMP-linked invasion protein (CLIP). CLAMP deficiency does not impact parasite adhesion or microneme protein secretion; however, knockdown of any member of the CLAMP complex affects rhoptry discharge. Phylogenetic analysis suggests orthologs of the essential complex components, CLAMP and CLIP, are ubiquitous across apicomplexans. SPATR appears to act as an accessory factor in Toxoplasma, but despite incomplete conservation is also essential for invasion during Plasmodium falciparum blood stages. Together, our results reveal a new protein complex that mediates rhoptry discharge following host-cell contact.


Asunto(s)
Toxoplasma , Toxoplasma/metabolismo , Micronema , Proteínas Protozoarias/metabolismo , Filogenia , Orgánulos/metabolismo
6.
Front Plant Sci ; 14: 1221790, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37900763

RESUMEN

Early determination of transgenic plants that are homozygous for a single locus T-DNA insert is highly desirable in most fundamental and applied transgenic research. This study aimed to build on an accurate, rapid, and reliable quantitative real-time PCR (qPCR) method to fast-track the development of multiple homozygous transgenic rice lines in the T1 generation, with low copy number to single T-DNA insert for further analyses. Here, a well-established qPCR protocol, based on the OsSBE4 reference gene and the nos terminator, was optimized in the transgenic Japonica rice cultivar Nipponbare, to distinguish homozygous single-insert plants with 100% accuracy. This method was successfully adapted to transgenic Indica rice plants carrying three different T-DNAs, without any modifications to quickly develop homozygous rice plants in the T1 generation. The accuracy of this qPCR method when applied to transgenic Indica rice approached 100% in 12 putative transgenic lines. Moreover, this protocol also successfully detected homozygous single-locus T-DNA transgenic rice plants with two-transgene T-DNAs, a feature likely to become more popular in future transgenic research. The assay was developed utilizing universal primers targeting common sequence elements of gene cassettes (the nos terminator). This assay could therefore be applied to other transgenic plants carrying the nos terminator. All procedures described here use standardized qPCR reaction conditions and relatively inexpensive dyes, such as SYBR Green, thus the qPCR method could be cost-effective and suitable for lower budget laboratories that are involved in rice transgenic research.

7.
PLoS Pathog ; 18(5): e1010139, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35512005

RESUMEN

The Toxoplasma gondii lytic cycle is a repetition of host cell invasion, replication, egress, and re-invasion into the next host cell. While the molecular players involved in egress have been studied in greater detail in recent years, the signals and pathways for triggering egress from the host cell have not been fully elucidated. A perforin-like protein, PLP1, has been shown to be necessary for permeabilizing the parasitophorous vacuole (PV) membrane or exit from the host cell. In vitro studies indicated that PLP1 is most active in acidic conditions, and indirect evidence using superecliptic pHluorin indicated that the PV pH drops prior to parasite egress. Using ratiometric pHluorin, a GFP variant that responds to changes in pH with changes in its bimodal excitation spectrum peaks, allowed us to directly measure the pH in the PV prior to and during egress by live-imaging microscopy. A statistically significant change was observed in PV pH during ionomycin or zaprinast induced egress in both wild-type RH and Δplp1 vacuoles compared to DMSO-treated vacuoles. Interestingly, if parasites are chemically paralyzed, a pH drop is still observed in RH but not in Δplp1 tachyzoites. This indicates that the pH drop is dependent on the presence of PLP1 or motility. Efforts to determine transporters, exchangers, or pumps that could contribute to the drop in PV pH identified two formate-nitrite transporters (FNTs). Auxin induced conditional knockdown and knockouts of FNT1 and FNT2 reduced the levels of lactate and pyruvate released by the parasites and lead to an abatement of vacuolar acidification. While additional transporters and molecules are undoubtedly involved, we provide evidence of a definitive reduction in vacuolar pH associated with induced and natural egress and characterize two transporters that contribute to the acidification.


Asunto(s)
Parásitos , Toxoplasma , Animales , Concentración de Iones de Hidrógeno , Parásitos/metabolismo , Perforina/metabolismo , Proteínas Protozoarias/metabolismo , Toxoplasma/metabolismo , Vacuolas/metabolismo
8.
Math Biosci Eng ; 18(4): 3227-3257, 2021 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-34198383

RESUMEN

Vascular endothelial growth factor (VEGF) is a key protein involved in the process of angiogenesis. VEGF is of particular interest after a traumatic brain injury (TBI), as it re-establishes the cerebral vascular network in effort to allow for proper cerebral blood flow and thereby oxygenation of damaged brain tissue. For this reason, angiogenesis is critical in the progression and recovery of TBI patients in the days and weeks post injury. Although well established experimental work has led to advances in our understanding of TBI and the progression of angiogenisis, many constraints still exist with existing methods, especially when considering patient progression in the days following injury. To better understand the healing process on the proposed time scales, we develop a computational model that quickly simulates vessel growth and recovery by coupling VEGF and its interactions with its associated receptors to a physiologically inspired fractal model of the microvascular re-growth. We use this model to clarify the role that diffusivity, receptor kinetics and location of the TBI play in overall blood volume restoration in the weeks post injury and show that proper therapeutic angiogenesis, or vasculogenic therapies, could speed recovery of the patient as a function of the location of injury.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Modelos Biológicos , Neovascularización Fisiológica , Circulación Cerebrovascular , Simulación por Computador , Humanos , Factor A de Crecimiento Endotelial Vascular
9.
mSphere ; : e0044421, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-34190588

RESUMEN

Egress from host cells is an essential step in the lytic cycle of T. gondii and other apicomplexan parasites; however, only a few parasite secretory proteins are known to affect this process. The putative metalloproteinase toxolysin 4 (TLN4) was previously shown to be an extensively processed microneme protein, but further characterization was impeded by the inability to genetically ablate TLN4. Here, we show that TLN4 has the structural properties of an M16 family metalloproteinase, that it possesses proteolytic activity on a model substrate, and that genetic disruption of TLN4 reduces the efficiency of egress from host cells. Complementation of the knockout strain with the TLN4 coding sequence significantly restored egress competency, affirming that the phenotype of the Δtln4 parasite was due to the absence of TLN4. This work identifies TLN4 as the first metalloproteinase and the second microneme protein to function in T. gondii egress. The study also lays a foundation for future mechanistic studies defining the precise role of TLN4 in parasite exit from host cells. IMPORTANCE After replicating within infected host cells, the single-celled parasite Toxoplasma gondii must rupture out of such cells in a process termed egress. Although it is known that T. gondii egress is an active event that involves disruption of host-derived membranes surrounding the parasite, very few proteins that are released by the parasite are known to facilitate egress. In this study, we identify a parasite secretory protease that is necessary for efficient and timely egress, laying the foundation for understanding precisely how this protease facilitates T. gondii exit from host cells.

10.
Expert Opin Investig Drugs ; 29(11): 1199-1208, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32869671

RESUMEN

INTRODUCTION: Triple negative breast cancer (TNBC) was once thought to be an insurmountable disease marked by a lack of targeted treatments. However, we are now witnessing the dawn of targeted therapies for TNBC in which progress has stemmed from an improved understanding of the components that make TNBC unique. The identification of biomarkers, such as BRCA1/2, PIK3CA and RSK2, have advanced the field remarkably and there is considerable interest in finding novel therapeutics for TNBC that offer durable clinical benefit with fewer adverse events. AREAS COVERED: We discuss phase I/II trials of new and emerging targeted therapies for TNBC, according to ClinicalTrials.gov up to June 2020. Although the emphasis is on ongoing and completed early phase trials, we also highlight pivotal studies that have led to the approval of new targeted classes of drugs for TNBC, with a focus on outcomes and common adverse events of each class of therapy. EXPERT OPINION: The way forward for TNBC treatment is through precision medicine. The use of novel agents matched with biomarkers to identify patients with the best chance of sustainable response offers new hope. We now have great potential for improving the outcomes for patients with TNBC.


Asunto(s)
Antineoplásicos/farmacología , Terapia Molecular Dirigida , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Biomarcadores de Tumor/metabolismo , Drogas en Investigación/farmacología , Femenino , Humanos , Medicina de Precisión , Neoplasias de la Mama Triple Negativas/patología
11.
J Clin Pharm Ther ; 45(4): 691-697, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32356381

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: Coronary artery disease (CAD) is the leading cause of mortality worldwide. Patient education is an essential part of cardiac patients' care targeting self-management behaviour to reduce risk factors and subsequent events. There has been no Vietnamese questionnaire to assess patient's knowledge about CAD; therefore, the purpose of this study was to translate, cross-culturally adapt and validate the Coronary Artery Disease Education Questionnaire-Short Version (CADE-Q SV) for use in Vietnam. METHODS: Translation and cross-cultural adaption of the tool were carried out in five stages: (a) two independent translations from English into Vietnamese were produced; (b) these two translations were then synthesized; (c) two translators blinded to the outcome measurements independently created separate back translations into English; (d) nine experts reached consensus on all items of the Vietnamese version of the CADE-Q SV; and (e) a pilot study was conducted on 35 patients with acute coronary syndrome (ACS). The validity and reliability of the questionnaires were then evaluated in 117 Vietnamese patients with ACS. The internal consistency and test-retest reliability were assessed by Cronbach's alpha and Cohen's kappa coefficient, respectively. Construct validity was determined by examining the relationship between knowledge scores and patient characteristics. RESULTS: The Vietnamese version of CADE-Q SV was created, including 20 items divided into two domains: medical and psychological condition, and nutrition and exercise. There was good equivalence between the original and the Vietnamese versions in all four areas: semantic, idiomatic, experiential and conceptual equivalence. Cronbach's alpha coefficients were acceptable for the questionnaire as a whole (0.78) and for the two domains: medical and psychological condition (0.71) and nutrition and exercise (0.52). All Cohen's kappa coefficients confirmed test-retest reliability (Kappa > 0.600; P < .001). Construct validity was confirmed by a significant correlation of knowledge scores with education level (P = .004). WHAT IS NEW AND CONCLUSION: The Vietnamese version of CADE-Q SV can be considered a valid and reliable questionnaire to evaluate patient's knowledge of CAD. Further studies could investigate the influence of knowledge scores on adherence to medications and clinical outcomes of patients with CAD.


Asunto(s)
Enfermedad de la Arteria Coronaria/psicología , Síndrome Coronario Agudo/psicología , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Vietnam
13.
Am J Med Genet A ; 179(12): 2382-2392, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31566869

RESUMEN

The aim of the study is to determine the prevalence, outcomes, and survival (among live births [LB]), in pregnancies diagnosed with trisomy 13 (T13) and 18 (T18), by congenital anomaly register and region. Twenty-four population- and hospital-based birth defects surveillance registers from 18 countries, contributed data on T13 and T18 between 1974 and 2014 using a common data-reporting protocol. The mean total birth prevalence (i.e., LB, stillbirths, and elective termination of pregnancy for fetal anomalies [ETOPFA]) in the registers with ETOPFA (n = 15) for T13 was 1.68 (95% CI 1.3-2.06), and for T18 was 4.08 (95% CI 3.01-5.15), per 10,000 births. The prevalence varied among the various registers. The mean prevalence among LB in all registers for T13 was 0.55 (95%CI 0.38-0.72), and for T18 was 1.07 (95% CI 0.77-1.38), per 10,000 births. The median mortality in the first week of life was 48% for T13 and 42% for T18, across all registers, half of which occurred on the first day of life. Across 16 registers with complete 1-year follow-up, mortality in first year of life was 87% for T13 and 88% for T18. This study provides an international perspective on prevalence and mortality of T13 and T18. Overall outcomes and survival among LB were poor with about half of live born infants not surviving first week of life; nevertheless about 10% survived the first year of life. Prevalence and outcomes varied by country and termination policies. The study highlights the variation in screening, data collection, and reporting practices for these conditions.


Asunto(s)
Síndrome de la Trisomía 13/epidemiología , Síndrome de la Trisomía 18/epidemiología , Femenino , Humanos , Nacimiento Vivo , Mortalidad , Vigilancia de la Población , Embarazo , Resultado del Embarazo , Diagnóstico Prenatal , Prevalencia , Sistema de Registros , Síndrome de la Trisomía 13/genética , Síndrome de la Trisomía 13/mortalidad , Síndrome de la Trisomía 18/genética , Síndrome de la Trisomía 18/mortalidad
14.
mBio ; 10(4)2019 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-31387907

RESUMEN

Toxoplasma gondii is a ubiquitous pathogen that can cause encephalitis, congenital defects, and ocular disease. T. gondii has also been implicated as a risk factor for mental illness in humans. The parasite persists in the brain as slow-growing bradyzoites contained within intracellular cysts. No treatments exist to eliminate this form of parasite. Although proteolytic degradation within the parasite lysosome-like vacuolar compartment (VAC) is critical for bradyzoite viability, whether other aspects of the VAC are important for parasite persistence remains unknown. An ortholog of Plasmodium falciparum chloroquine resistance transporter (CRT), TgCRT, has previously been identified in T. gondii To interrogate the function of TgCRT in chronic-stage bradyzoites and its role in persistence, we knocked out TgCRT in a cystogenic strain and assessed VAC size, VAC digestion of host-derived proteins and parasite autophagosomes, and the viability of in vitro and in vivo bradyzoites. We found that whereas parasites deficient in TgCRT exhibit normal digestion within the VAC, they display a markedly distended VAC and their viability is compromised both in vitro and in vivo Interestingly, impairing VAC proteolysis in TgCRT-deficient bradyzoites restored VAC size, consistent with a role for TgCRT as a transporter of products of digestion from the VAC. In conjunction with earlier studies, our current findings suggest a functional link between TgCRT and VAC proteolysis. This study provides further evidence of a crucial role for the VAC in bradyzoite persistence and a new potential VAC target to abate chronic Toxoplasma infection.IMPORTANCE Individuals chronically infected with the intracellular parasite Toxoplasma gondii are at risk of experiencing reactivated disease that can result in progressive loss of vision. No effective treatments exist for chronic toxoplasmosis due in part to a poor understanding of the biology underlying chronic infection and a lack of well-validated potential targets. We show here that a T. gondii transporter is functionally linked to protein digestion within the parasite lysosome-like organelle and that this transporter is necessary to sustain chronic infection in culture and in experimentally infected mice. Ablating the transporter results in severe bloating of the lysosome-like organelle. Together with earlier work, this study suggests the parasite's lysosome-like organelle is vital for parasite survival, thus rendering it a potential target for diminishing infection and reducing the risk of reactivated disease.


Asunto(s)
Proteínas de Transporte de Membrana/metabolismo , Proteínas Protozoarias/metabolismo , Toxoplasma/crecimiento & desarrollo , Toxoplasma/metabolismo , Toxoplasmosis/parasitología , Vacuolas/metabolismo , Animales , Autofagosomas/metabolismo , Supervivencia Celular , Femenino , Humanos , Estadios del Ciclo de Vida , Lisosomas/genética , Lisosomas/metabolismo , Proteínas de Transporte de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Proteolisis , Proteínas Protozoarias/genética , Toxoplasma/genética , Vacuolas/genética
15.
MMWR Morb Mortal Wkly Rep ; 68(2): 31-36, 2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30653484

RESUMEN

Prevalence of gastroschisis, a serious birth defect of the abdominal wall resulting in some of the abdominal contents extending outside the body at birth, has been increasing worldwide (1,2). Gastroschisis requires surgical repair after birth and is associated with digestive and feeding complications during infancy, which can affect development. Recent data from 14 U.S. states indicated an increasing prevalence of gastroschisis from 1995 to 2012 (1). Young maternal age has been strongly associated with gastroschisis, but research suggests that risk factors such as smoking, genitourinary infections, and prescription opioid use also might be associated (3-5). Data from 20 population-based state surveillance programs were pooled and analyzed to assess age-specific gastroschisis prevalence during two 5-year periods, 2006-2010 and 2011-2015, and an ecologic approach was used to compare annual gastroschisis prevalence by annual opioid prescription rate categories. Gastroschisis prevalence increased only slightly (10%) from 2006-2010 to 2011-2015 (prevalence ratio = 1.1, 95% confidence interval [CI] = 1.0-1.1), with the highest prevalence among mothers aged <20 years. During 2006-2015, the prevalence of gastroschisis was 1.6 times higher in counties with high opioid prescription rates (5.1 per 10,000 live births; CI = 4.9-5.3) and 1.4 times higher where opioid prescription rates were medium (4.6 per 10,000 live births; CI = 4.4-4.8) compared with areas with low prescription rates (3.2 per 10,000 live births; CI = 3.1-3.4). Public health research is needed to understand factors contributing to the association between young maternal age and gastroschisis and assess the effect of prescription opioid use during pregnancy on this pregnancy outcome.


Asunto(s)
Analgésicos Opioides/uso terapéutico , Prescripciones de Medicamentos/estadística & datos numéricos , Fenómenos Ecológicos y Ambientales , Gastrosquisis/epidemiología , Adulto , Distribución por Edad , Analgésicos Opioides/efectos adversos , Etnicidad/estadística & datos numéricos , Femenino , Gastrosquisis/etnología , Humanos , Recién Nacido , Madres/estadística & datos numéricos , Embarazo , Efectos Tardíos de la Exposición Prenatal , Prevalencia , Grupos Raciales/estadística & datos numéricos , Factores de Riesgo , Estados Unidos/epidemiología , Adulto Joven
16.
J Biol Chem ; 294(5): 1541-1553, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30514763

RESUMEN

Toxoplasma gondii is a ubiquitous, obligate intracellular eukaryotic parasite that causes congenital birth defects, disease in immunocompromised individuals, and blindness. Protein glycosylation plays an important role in the infectivity and evasion of immune responses of many eukaryotic parasites and is also of great relevance to vaccine design. Here we demonstrate that micronemal protein 2 (MIC2), a motility-associated adhesin of T. gondii, has highly glycosylated thrombospondin repeat (TSR) domains. Using affinity-purified MIC2 and MS/MS analysis along with enzymatic digestion assays, we observed that at least seven C-linked and three O-linked glycosylation sites exist within MIC2, with >95% occupancy at these O-glycosylation sites. We found that addition of O-glycans to MIC2 is mediated by a protein O-fucosyltransferase 2 homolog (TgPOFUT2) encoded by the TGGT1_273550 gene. Even though POFUT2 homologs are important for stabilizing motility-associated adhesins and for host infection in other apicomplexan parasites, loss of TgPOFUT2 in T. gondii had only a modest impact on MIC2 levels and the wider parasite proteome. Consistent with this, both plaque formation and tachyzoite invasion were broadly similar in the presence or absence of TgPOFUT2. These findings indicate that TgPOFUT2 O-glycosylates MIC2 and that this glycan, in contrast to previous findings in another study, is dispensable in T. gondii tachyzoites and for T. gondii infectivity.


Asunto(s)
Fibroblastos/parasitología , Fucosiltransferasas/metabolismo , Interacciones Huésped-Parásitos , Proteínas de la Membrana/metabolismo , Proteínas Protozoarias/metabolismo , Toxoplasma/patogenicidad , Toxoplasmosis/parasitología , Células Cultivadas , Fibroblastos/citología , Fibroblastos/metabolismo , Glicosilación , Humanos , Proteoma/análisis , Toxoplasmosis/metabolismo
17.
PLoS Pathog ; 14(12): e1007476, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30513119

RESUMEN

Intracellular pathogens must egress from the host cell to continue their infectious cycle. Apicomplexans are a phylum of intracellular protozoans that have evolved members of the membrane attack complex and perforin (MACPF) family of pore forming proteins to disrupt cellular membranes for traversing cells during tissue migration or egress from a replicative vacuole following intracellular reproduction. Previous work showed that the apicomplexan Toxoplasma gondii secretes a perforin-like protein (TgPLP1) that contains a C-terminal Domain (CTD) which is necessary for efficient parasite egress. However, the structural basis for CTD membrane binding and egress competency remained unknown. Here, we present evidence that TgPLP1 CTD prefers binding lipids that are abundant in the inner leaflet of the lipid bilayer. Additionally, solving the high-resolution crystal structure of the TgPLP1 APCß domain within the CTD reveals an unusual double-layered ß-prism fold that resembles only one other protein of known structure. Three direct repeat sequences comprise subdomains, with each constituting a wall of the ß-prism fold. One subdomain features a protruding hydrophobic loop with an exposed tryptophan at its tip. Spectrophotometric measurements of intrinsic tryptophan fluorescence are consistent with insertion of the hydrophobic loop into a target membrane. Using CRISPR/Cas9 gene editing we show that parasite strains bearing mutations in the hydrophobic loop, including alanine substitution of the tip tryptophan, are equally deficient in egress as a strain lacking TgPLP1 altogether. Taken together our findings suggest a crucial role for the hydrophobic loop in anchoring TgPLP1 to the membrane to support its cytolytic activity and egress function.


Asunto(s)
Perforina/metabolismo , Proteínas Protozoarias/metabolismo , Toxoplasma/patogenicidad , Toxoplasmosis/metabolismo , Membrana Celular/metabolismo , Humanos , Perforina/química , Conformación Proteica , Proteínas Protozoarias/química , Toxoplasma/química
18.
Birth Defects Res ; 110(19): 1478-1486, 2018 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-30444307

RESUMEN

BACKGROUND/OBJECTIVES: In this data brief, we examine major eye and ear anomalies (anophthalmia/microphthalmia, anotia/microtia, and congenital cataract) for a recent 5-year birth cohort using data from 30 population-based birth defects surveillance programs in the United States. METHODS: As a special call for data for the 2018 NBDPN Annual Report, state programs reported expanded data on eye/ear anomalies for birth years 2011-2015. We calculated the combined overall prevalence (per 10,000 live births) and 95% confidence intervals (CI), for the three anomalies as well as by maternal age, maternal race/ethnicity, infant sex, laterality, presence/absence of other major birth defects, and case ascertainment methodology utilized by the program (active vs. passive). RESULTS: The overall prevalence estimate (per 10,000 live births) was 1.5 (95% CI: 1.4-1.5) for anophthalmia/microphthalmia, 1.5 (95% CI: 1.4-1.6) for congenital cataract, and 1.8 (95% CI: 1.7-1.8) for anotia/microtia. Congenital cataract prevalence varied little by maternal race/ethnicity, infant sex, or case ascertainment methodology; prevalence differences were more apparent across strata for anophthalmia/microphthalmia and anotia/microtia. Prevalence among active vs. passive ascertainment programs was 50% higher for anophthalmia/microphthalmia (1.9 vs. 1.2) and two-fold higher for anotia/microtia (2.6 vs. 1.2). Anophthalmia/microphthalmia was more likely than other conditions to co-occur with other birth defects. All conditions were more frequent among older mothers (40+ years). CONCLUSIONS: This data brief provides recent prevalence estimates for anophthalmia/microphthalmia, congenital cataract, and anotia/microtia that address a data gap by examining pooled data from 30 population-based surveillance systems, covering a five-year birth cohort of about 12.4 million births.


Asunto(s)
Anoftalmos/epidemiología , Microtia Congénita/epidemiología , Microftalmía/epidemiología , Adulto , Estudios de Casos y Controles , Catarata/epidemiología , Anomalías Congénitas/epidemiología , Oído/anomalías , Anomalías del Ojo , Femenino , Humanos , Lactante , Recién Nacido , Modelos Logísticos , Masculino , Edad Materna , Madres , Oportunidad Relativa , Vigilancia de la Población/métodos , Embarazo , Prevalencia , Sistema de Registros , Factores de Riesgo , Estados Unidos
19.
Sci Rep ; 8(1): 5025, 2018 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-29567944

RESUMEN

Development of metabolic syndrome is associated with hyperactivity of the HPA axis characterized by elevated levels of circulating adrenal hormones including cortisol and aldosterone. However, the molecular mechanism leading to the dysregulation of the HPA axis is not well elucidated. In this study, we found that insulin regulates adrenal steroidogenesis by increasing the expression and activity of steroidogenic factor 1 (SF-1) both in vitro and in vivo and this insulin effect was partly through inhibition of FoxO1. Specifically, insulin increased the protein and RNA levels of SF-1 and steroidogenic target genes. Further, adrenal SF-1 expression was significantly increased by hyperactivation of insulin signaling in mice. Together with the elevated SF-1 expression in adrenal glands, hyperactivation of insulin signaling led to increased aldosterone and corticosterone levels. On the other hand, suppressing the insulin signaling using streptozotocin markedly reduced the expression of adrenal SF-1 in mice. In addition, overexpression of FoxO1 significantly suppressed SF-1 and its steroidogenic target genes implying that the positive effect of insulin on SF-1 activity might be through suppression of FoxO1 in the adrenal gland. Taken together, these results indicate that insulin regulates adrenal steroidogenesis through coordinated control of SF-1 and FoxO1.


Asunto(s)
Corteza Suprarrenal/metabolismo , Aldosterona/biosíntesis , Corticosterona/biosíntesis , Diabetes Mellitus Experimental/metabolismo , Proteína Forkhead Box O1/metabolismo , Insulina/metabolismo , Factor Esteroidogénico 1/metabolismo , Corteza Suprarrenal/citología , Aldosterona/sangre , Animales , Vías Biosintéticas/efectos de los fármacos , Vías Biosintéticas/fisiología , Línea Celular Tumoral , Corticosterona/sangre , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/etiología , Dieta Alta en Grasa/efectos adversos , Femenino , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Sistema Hipotálamo-Hipofisario/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Fosforilación/fisiología , Sistema Hipófiso-Suprarrenal/fisiología , ARN Interferente Pequeño/metabolismo , Factor Esteroidogénico 1/genética , Estreptozocina/toxicidad
20.
Exp Mol Med ; 50(2): e437, 2018 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-29391540

RESUMEN

4-hydroxy-3-methoxycinnamic acid (ferulic acid, FA) is known to have numerous beneficial health effects, including anti-obesity and anti-hyperglycemic properties. However, the molecular networks that modulate the beneficial FA-induced metabolic effects have not been well elucidated. In this study, we explored the molecular mechanisms mediating the beneficial metabolic effects of FA. In mice, FA protected against high-fat diet-induced weight gain, reduced food intake and exhibited an overall improved metabolic phenotype. The food intake suppression by FA was accompanied by a specific reduction in hypothalamic orexigenic neuropeptides, including agouti-related protein and neuropeptide Y, with no significant changes in the anorexigenic peptides pro-opiomelanocortin and cocaine and amphetamine-regulated transcript. FA treatment also inhibited fat accumulation in the liver and white adipose tissue and suppressed the expression of gluconeogenic genes, including phosphoenolpyruvate carboxylase and glucose-6-phosphatase. Furthermore, we show that FA phosphorylated and inactivated the transcription factor FoxO1, which positively regulates the expression of gluconeogenic and orexigenic genes, providing evidence that FA might exert its beneficial metabolic effects through inhibition of FoxO1 function in the periphery and the hypothalamus.


Asunto(s)
Ácidos Cumáricos/farmacología , Proteína Forkhead Box O1/metabolismo , Glucosa/metabolismo , Homeostasis/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Neuropéptidos/metabolismo , Animales , Biomarcadores , Línea Celular , Dieta Alta en Grasa , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/genética , Regulación de la Expresión Génica/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Masculino , Ratones , Fosforilación
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