491 research outputs found
A Novel Transcription Factor, T-bet, Directs Th1 Lineage Commitment
AbstractNaive T helper cells differentiate into two subsets, Th1 and Th2, each with distinct functions and cytokine profiles. Here, we report the isolation of T-bet, a Th1-specific T box transcription factor that controls the expression of the hallmark Th1 cytokine, IFNγ. T-bet expression correlates with IFNγ expression in Th1 and NK cells. Ectopic expression of T-bet both transactivates the IFNγ gene and induces endogenous IFNγ production. Remarkably, retroviral gene transduction of T-bet into polarized Th2 and Tc2 primary T cells redirects them into Th1 and Tc1 cells, respectively, as evidenced by the simultaneous induction of IFNγ and repression of IL-4 and IL-5. Thus, T-bet initiates Th1 lineage development from naive Thp cells both by activating Th1 genetic programs and by repressing the opposing Th2 programs
Cutaneous nociception evoked by 15-delta PGJ2 via activation of ion channel TRPA1
<p>Abstract</p> <p>Background</p> <p>A number of prostaglandins (PGs) sensitize dorsal root ganglion (DRG) neurons and contribute to inflammatory hyperalgesia by signaling through specific G protein-coupled receptors (GPCRs). One mechanism whereby PGs sensitize these neurons is through modulation of "thermoTRPs," a subset of ion channels activated by temperature belonging to the Transient Receptor Potential ion channel superfamily. Acrid, electrophilic chemicals including cinnamaldehyde (CA) and allyl isothiocyanate (AITC), derivatives of cinnamon and mustard oil respectively, activate thermoTRP member TRPA1 via direct modification of channel cysteine residues.</p> <p>Results</p> <p>Our search for endogenous chemical activators utilizing a bioactive lipid library screen identified a cyclopentane PGD<sub>2 </sub>metabolite, 15-deoxy-Δ<sup>12,14</sup>-prostaglandin J<sub>2 </sub>(15d-PGJ<sub>2</sub>), as a TRPA1 agonist. Similar to CA and AITC, this electrophilic molecule is known to modify cysteines of cellular target proteins. Electophysiological recordings verified that 15d-PGJ<sub>2 </sub>specifically activates TRPA1 and not TRPV1 or TRPM8 (thermoTRPs also enriched in DRG). Accordingly, we identified a population of mouse DRG neurons responsive to 15d-PGJ<sub>2 </sub>and AITC that is absent in cultures derived from TRPA1 knockout mice. The irritant molecules that activate TRPA1 evoke nociceptive responses. However, 15d-PGJ<sub>2 </sub>has not been correlated with painful sensations; rather, it is considered to mediate anti-inflammatory processes via binding to the nuclear peroxisome proliferator-activated receptor gamma (PPARγ). Our <it>in vivo </it>studies revealed that 15d-PGJ<sub>2 </sub>induced acute nociceptive responses when administered cutaneously. Moreover, mice deficient in the TRPA1 channel failed to exhibit such behaviors.</p> <p>Conclusion</p> <p>In conclusion, we show that 15d-PGJ<sub>2 </sub>induces acute nociception when administered cutaneously and does so via a TRPA1-specific mechanism.</p
Exosomes neutralize synaptic-plasticity-disrupting activity of Aβ assemblies in vivo
Background: Exosomes, small extracellular vesicles of endosomal origin, have been suggested to be involved in both the metabolism and aggregation of Alzheimer’s disease (AD)-associated amyloid β-protein (Aβ). Despite their ubiquitous presence and the inclusion of components which can potentially interact with Aβ, the role of exosomes in regulating synaptic dysfunction induced by Aβ has not been explored. Results: We here provide in vivo evidence that exosomes derived from N2a cells or human cerebrospinal fluid can abrogate the synaptic-plasticity-disrupting activity of both synthetic and AD brain-derived Aβ. Mechanistically, this effect involves sequestration of synaptotoxic Aβ assemblies by exosomal surface proteins such as PrPC rather than Aβ proteolysis. Conclusions: These data suggest that exosomes can counteract the inhibitory action of Aβ, which contributes to perpetual capability for synaptic plasticity
Caregiver Participation Engagement in Child Mental Health Prevention Programs: a Systematic Review
Prevention programs are a key method to reduce the prevalence and impact of mental health disorders in childhood and adolescence. Caregiver participation engagement (CPE), which includes caregiver participation in sessions as well as follow-through with homework plans, is theorized to be an important component in the effectiveness of these programs. This systematic review aims to (1) describe the terms used to operationalize CPE and the measurement of CPE in prevention programs, (2) identify factors associated with CPE, (3) examine associations between CPE and outcomes, and (4) explore the effects of strategies used to enhance CPE. Thirty-nine articles representing 27 unique projects were reviewed. Articles were included if they examined CPE in a program that focused to some extent on preventing child mental health disorders. There was heterogeneity in both the terms used to describe CPE and the measurement of CPE. The majority of projects focused on assessment of caregiver home practice. There were no clear findings regarding determinants of CPE. With regard to the impact of CPE on program outcomes, higher levels of CPE predicted greater improvements in child and caregiver outcomes, as well as caregiver-child relationship quality. Finally, a small number of studies found that motivational and behavioral strategies (e.g., reinforcement, appointment reminders) were successful in promoting CPE. This review highlights the importance of considering CPE when developing, testing, and implementing prevention programs for child mental health disorders. Increased uniformity is needed in the measurement of CPE to facilitate a better understanding of determinants of CPE. In addition, the field would benefit from further evaluating strategies to increase CPE as a method of increasing the potency of prevention programs
Provider beliefs in effectiveness and recommendations for primary HPV testing in 3 health-care systems
In 2018, the US Preventive Services Task Force endorsed primary human papillomavirus testing (pHPV) for cervical cancer screening. We aimed to describe providers\u27 beliefs about pHPV testing effectiveness and which screening approach they regularly recommend. We invited providers who performed 10 or more cervical cancer screens in 2019 in 3 healthcare systems that had not adopted pHPV testing: Kaiser Permanente Washington, Mass General Brigham, and Parkland Health; 53.7% (501/933) completed the survey between October and December 2020. Response distributions varied across modalities (P \u3c .001), with cytology alone or cotesting being more often viewed as somewhat or very effective for 30- to 65-year-olds compared with pHPV (cytology alone 94.1%, cotesting 96.1%, pHPV 66.0%). In 21- to 29-year-olds, the pattern was similar (cytology alone 92.2%, 64.7% cotesting, 50.8% pHPV). Most providers were either incorrect or unsure of the guideline-recommended screening interval for pHPV. Educational efforts are needed about the relative effectiveness and recommended use of pHPV to promote guideline-concordant care
Functional cardiac fibroblasts derived from human pluripotent stem cells via second heart field progenitors
Cardiac fibroblasts (CFs) play critical roles in heart development, homeostasis, and disease. The limited availability of human CFs from native heart impedes investigations of CF biology and their role in disease. Human pluripotent stem cells (hPSCs) provide a highly renewable and genetically defined cell source, but efficient methods to generate CFs from hPSCs have not been described. Here, we show differentiation of hPSCs using sequential modulation of Wnt and FGF signaling to generate second heart field progenitors that efficiently give rise to hPSC-CFs. The hPSC-CFs resemble native heart CFs in cell morphology, proliferation, gene expression, fibroblast marker expression, production of extracellular matrix and myofibroblast transformation induced by TGFβ1 and angiotensin II. Furthermore, hPSC-CFs exhibit a more embryonic phenotype when compared to fetal and adult primary human CFs. Co-culture of hPSC-CFs with hPSC-derived cardiomyocytes distinctly alters the electrophysiological properties of the cardiomyocytes compared to co-culture with dermal fibroblasts. The hPSC-CFs provide a powerful cell source for research, drug discovery, precision medicine, and therapeutic applications in cardiac regeneration.J.L.C. received funding from Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior and Fundação de Amparo à Pesquisa do Distrito Federal. The work was funded by NIH R01 HL129798 (T.J.K.); NIH U01
HL134764 (T.J.K.); S10RR025644 (T.J.K.); and the UW Institute for Clinical and Translational Research, grant UL1TR000427, from the Clinical and Translational Science Award of the NCATS/NIH.S
Immunofluorescent Detection of Two Thymidine Analogues (CldU and IdU) in Primary Tissue
Accurate measurement of cell division is a fundamental challenge in experimental biology that becomes increasingly complex when slowly dividing cells are analyzed. Established methods to detect cell division include direct visualization by continuous microscopy in cell culture, dilution of vital dyes such as carboxyfluorescein di-aetate succinimidyl ester (CFSE), immuno-detection of mitogenic antigens such as ki67 or PCNA, and thymidine analogues. Thymidine analogues can be detected by a variety of methods including radio-detection for tritiated thymidine, immuno-detection for bromo-deoxyuridine (BrdU), chloro-deoxyuridine (CldU) and iodo-deoxyuridine (IdU), and chemical detection for ethinyl-deoxyuridine (EdU). We have derived a strategy to detect sequential incorporation of different thymidine analogues (CldU and IdU) into tissues of adult mice. Our method allows investigators to accurately quantify two successive rounds of cell division. By optimizing immunostaining protocols our approach can detect very low dose thymidine analogues administered via the drinking water, safe to administer to mice for prolonged periods of time. Consequently, our technique can be used to detect cell turnover in very long-lived tissues. Optimal immunofluoresent staining results can be achieved in multiple tissue types, including pancreas, skin, gut, liver, adrenal, testis, ovary, thyroid, lymph node, and brain. We have also applied this technique to identify oncogenic transformation within tissues. We have further applied this technique to determine if transit-amplifying cells contribute to growth or renewal of tissues. In this sense, sequential administration of thymidine analogues represents a novel approach for studying the origins and survival of cells involved in tissue homeostasis
Independent Review Of Social And Population Variation In Mental Health Could Improve Diagnosis In DSM Revisions
At stake in the May 2013 publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), are billions of dollars in insurance payments and government resources, as well as the diagnoses and treatment of millions of patients. We argue that the most recent revision process has missed social determinants of mental health disorders and their diagnosis: environmental factors triggering biological responses that manifest themselves in behavior; differing cultural perceptions about what is normal and what is abnormal behavior; and institutional pressures related to such matters as insurance reimbursements, disability benefits, and pharmaceutical marketing. In addition, the experts charged with revising the DSM lack a systematic. way to take population-level variations in diagnoses into account. To address these problems, we propose the creation of an independent research review body that would monitor variations in diagnostic patterns, inform future DSM revisions, identify needed changes in mental health policy and practice, and recommend new avenues of research. Drawing on the best available knowledge, the review body would make possible more precise and equitable psychiatric diagnoses and interventions
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Refining the accuracy of validated target identification through coding variant fine-mapping in type 2 diabetes.
We aggregated coding variant data for 81,412 type 2 diabetes cases and 370,832 controls of diverse ancestry, identifying 40 coding variant association signals (P < 2.2 × 10-7); of these, 16 map outside known risk-associated loci. We make two important observations. First, only five of these signals are driven by low-frequency variants: even for these, effect sizes are modest (odds ratio ≤1.29). Second, when we used large-scale genome-wide association data to fine-map the associated variants in their regional context, accounting for the global enrichment of complex trait associations in coding sequence, compelling evidence for coding variant causality was obtained for only 16 signals. At 13 others, the associated coding variants clearly represent 'false leads' with potential to generate erroneous mechanistic inference. Coding variant associations offer a direct route to biological insight for complex diseases and identification of validated therapeutic targets; however, appropriate mechanistic inference requires careful specification of their causal contribution to disease predisposition
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