Wnt Signaling in Zebrafish Fin Regeneration: Chemical Biology Using GSK3b Inhibitors

poster abstractBone growth can be impaired due to disease, such as osteoporosis, and Wnt signaling pathways regulate bone growth. The parathyroid hormone (PTH) is therapeutic for anabolic bone growth (bone building), which activates Wnt signaling, leading to bone growth. GSK3b (glycogen synthetase kinase 3 beta) protein inhibitors activate Wnt signaling, including in bone growth models. Our study utilized a zebrafish model system to study Wnt activated fin regeneration and bone growth. Wnt signaling is the first genetically identified step in fin regeneration, and bony rays are the main differentiated cell type in fins. Thus, zebrafish fin regeneration may be a useful model to study Wnt signaling mediated bone growth. Fin regeneration experiments were conducted using various concentrations of GSK3b inhibitor compound for different treatment periods and regenerative outgrowth was measured at 4 and 7 days post amputation. Experiments revealed continuous low concentration (5-6 nM) treatment to be most effective at increasing regeneration. Higher concentrations inhibited fin growth, perhaps by excessive stimulation of differentiation programs. In situ hybridization experiments were performed to examine effects of Gsk3b inhibitor on Wnt responsive gene expression. Initial experiments show temporal and spatial changes on individual gene markers following GSK3b inhibitor treatment. Additionally, confocal microscopy and immunofluorescence labeling data indicated that the Wnt signaling intracellular signal transducer, betacatenin, accumulates throughout Gsk3b inhibitor treated tissues. Finally, experiments are underway to quantify phosphohistone-3 staining in regenerating tissue to measure effects of Gsk3b inhibitor on cell proliferation. Together, these data indicate that bone growth in zebrafish fin regeneration is improved by activating Wnt signaling. Zebrafish Wnt signaling experiments provide good model to study bone growth and bone repair mechanisms, and may provide an efficient drug discovery platform

Three red suns in the sky: A transiting, terrestrial planet in a triple M-dwarf system at 6.9 pc

We present the discovery from Transiting Exoplanet Survey Satellite (TESS) data of LTT 1445Ab. At a distance of 6.9 pc, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use MEarth data and results from the Science Processing Operations Center data validation report to determine that the planet transits the primary star in the system. The planet has a radius of ${1.38}_{-0.12}^{+0.13}$ ${R}_{\oplus }$, an orbital period of ${5.35882}_{-0.00031}^{+0.00030}$ days, and an equilibrium temperature of ${433}_{-27}^{+28}$ K. With radial velocities from the High Accuracy Radial Velocity Planet Searcher, we place a 3σ upper mass limit of 8.4 ${M}_{\oplus }$ on the planet. LTT 1445Ab provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. We also present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicate a moderate amount of variability, in agreement with that observed in the TESS light-curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system hints that the entire system may be co-planar, implying that the system may have formed from the early fragmentation of an individual protostellar core.Accepted manuscrip

Patient-reported symptom burden of Charcot-Marie-Tooth Disease Type 1A: findings from an observational digital lifestyle study

Objectives: This study aims to explore the impact of Charcot-Marie-Tooth disease type 1A (CMT1A) and its treatment on patients in European (France, Germany, Italy, Spain, and the United Kingdom) and US real-world practice. Methods: Adults with CMT1A (n = 937) were recruited to an ongoing observational study exploring the impact of CMT. Data were collected via CMT&Me, an app through which participants completed patient-reported outcome measures. Results: Symptoms ranked with highest importance were weakness in the extremities, difficulty in walking, and fatigue. Almost half of participants experienced a worsening of symptom severity since diagnosis. Anxiety and depression were each reported by over one-third of participants. Use of rehabilitative interventions, medications, and orthotics/walking aids was high. Conclusions: Patient-reported burden of CMT1A is high, influenced by difficulties in using limbs, fatigue, pain, and impaired quality of life. Burden severity appears to differ across the population, possibly driven by differences in rehabilitative and prescription-based interventions, and country-specific health care variability

Trans-Ethnic Mapping of BANK1 Identifies Two Independent SLE-Risk Linkage Groups Enriched for Co-Transcriptional Splicing Marks

BANK1 is a susceptibility gene for several systemic autoimmune diseases in several populations. Using the genome-wide association study (GWAS) data from Europeans (EUR) and African Americans (AA), we performed an extensive fine mapping of ankyrin repeats 1 (BANK1). To increase the SNP density, we used imputation followed by univariate and conditional analysis, combinedwith a haplotypic and expression quantitative trait locus (eQTL) analysis. The data from Europeans showed that the associated region was restricted to a minimal and dependent set of SNPs covering introns two and three, and exon two. In AA, the signal found in the Europeans was split into two independent effects. All of the major risk associated SNPs were eQTLs, and the risks were associated with an increased BANK1 gene expression. Functional annotation analysis revealed the enrichment of repressive B cell epigenomicmarks (EZH2 and H3K27me3) and a strong enrichment of splice junctions. Furthermore, one eQTL located in intron two, rs13106926, was found within the binding site for RUNX3, a transcriptional activator. These results connect the local genome topography, chromatin structure, and the regulatory landscape of BANK1 with co-transcriptional splicing of exon two. Our data defines a minimal set of risk associated eQTLs predicted to be involved in the expression of BANK1 modulated through epigenetic regulation and splicing. These findings allow us to suggest that the increased expression of BANK1 will have an impact on B-cell mediated disease pathways.The work presented in this paper has been supported by the Ministerio de Economía y Competitividad, Spain (SAF2016-78631-P), partly co-financed by FEDER funds of the European Union, the Gustaf den V:e-80-års Fond and the Swedish Association against Rheumatism to M.E.A-R. In addition, this work was financed by the NIH P01 grant P01-AI-083194 to C.D.L., J.B.H., R.K., and M.E.A-R. JBH: NIH grants: R01 AI024717, U01 HG00866, P30 AR070549 and U01 AI130830 and the US Department of Veterans Affairs: I01 BX001834.C.D.L.: Center for Public Health Genomics. R.K.: NIH grant R01-AR33062. J.A.J.: NIH grants U54GM104938, P30AR053483

CDK19-related disorder results from both loss-of-function and gain-of-function de novo missense variants

Purpose To expand the recent description of a new neurodevelopmental syndrome related to alterations in CDK19. Methods Individuals were identified through international collaboration. Functional studies included autophosphorylation assays for CDK19 Gly28Arg and Tyr32His variants and in vivo zebrafish assays of the CDK19(G28R) and CDK19(Y32H). Results We describe 11 unrelated individuals (age range: 9 months to 14 years) with de novo missense variants mapped to the kinase domain of CDK19, including two recurrent changes at residues Tyr32 and Gly28. In vitro autophosphorylation and substrate phosphorylation assays revealed that kinase activity of protein was lower for p.Gly28Arg and higher for p.Tyr32His substitutions compared with that of the wild-type protein. Injection of CDK19 messenger RNA (mRNA) with either the Tyr32His or the Gly28Arg variants using in vivo zebrafish model significantly increased fraction of embryos with morphological abnormalities. Overall, the phenotype of the now 14 individuals with CDK19-related disorder includes universal developmental delay and facial dysmorphism, hypotonia (79%), seizures (64%), ophthalmologic anomalies (64%), and autism/autistic traits (56%). Conclusion CDK19 de novo missense variants are responsible for a novel neurodevelopmental disorder. Both kinase assay and zebrafish experiments showed that the pathogenetic mechanism may be more diverse than previously thought.Peer reviewe

Variants at multiple loci implicated in both innate and adaptive immune responses are associated with Sjögren’s syndrome

Sjögren’s syndrome is a common autoimmune disease (~0.7% of European Americans) typically presenting as keratoconjunctivitis sicca and xerostomia. In addition to strong association within the HLA region at 6p21 (Pmeta=7.65×10−114), we establish associations with IRF5-TNPO3 (Pmeta=2.73×10−19), STAT4 (Pmeta=6.80×10−15), IL12A (Pmeta =1.17×10−10), FAM167A-BLK (Pmeta=4.97×10−10), DDX6-CXCR5 (Pmeta=1.10×10−8), and TNIP1 (Pmeta=3.30×10−8). Suggestive associations with Pmeta<5×10−5 were observed with 29 regions including TNFAIP3, PTTG1, PRDM1, DGKQ, FCGR2A, IRAK1BP1, ITSN2, and PHIP amongst others. These results highlight the importance of genes involved in both innate and adaptive immunity in Sjögren’s syndrome

A second planet transiting LTT 1445A and a determination of the masses of both worlds

K.H. acknowledges support from STFC grant ST/R000824/1.LTT 1445 is a hierarchical triple M-dwarf star system located at a distance of 6.86 pc. The primary star LTT 1445A (0.257 M⊙) is known to host the transiting planet LTT 1445Ab with an orbital period of 5.36 days, making it the second-closest known transiting exoplanet system, and the closest one for which the host is an M dwarf. Using Transiting Exoplanet Survey Satellite data, we present the discovery of a second planet in the LTT 1445 system, with an orbital period of 3.12 days. We combine radial-velocity measurements obtained from the five spectrographs, Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, High Accuracy Radial Velocity Planet Searcher, High-Resolution Echelle Spectrometer, MAROON-X, and Planet Finder Spectrograph to establish that the new world also orbits LTT 1445A. We determine the mass and radius of LTT 1445Ab to be 2.87 ± 0.25 M⊕ and 1.304-0.060+0.067 R⊕, consistent with an Earth-like composition. For the newly discovered LTT 1445Ac, we measure a mass of 1.54-0.19+0.20 M⊕ and a minimum radius of 1.15 R⊕, but we cannot determine the radius directly as the signal-to-noise ratio of our light curve permits both grazing and nongrazing configurations. Using MEarth photometry and ground-based spectroscopy, we establish that star C (0.161 M⊙) is likely the source of the 1.4 day rotation period, and star B (0.215 M⊙) has a likely rotation period of 6.7 days. We estimate a probable rotation period of 85 days for LTT 1445A. Thus, this triple M-dwarf system appears to be in a special evolutionary stage where the most massive M dwarf has spun down, the intermediate mass M dwarf is in the process of spinning down, while the least massive stellar component has not yet begun to spin down.Publisher PDFPeer reviewe

Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists

Psychosocial impact of undergoing prostate cancer screening for men with BRCA1 or BRCA2 mutations.

OBJECTIVES: To report the baseline results of a longitudinal psychosocial study that forms part of the IMPACT study, a multi-national investigation of targeted prostate cancer (PCa) screening among men with a known pathogenic germline mutation in the BRCA1 or BRCA2 genes. PARTICPANTS AND METHODS: Men enrolled in the IMPACT study were invited to complete a questionnaire at collaborating sites prior to each annual screening visit. The questionnaire included sociodemographic characteristics and the following measures: the Hospital Anxiety and Depression Scale (HADS), Impact of Event Scale (IES), 36-item short-form health survey (SF-36), Memorial Anxiety Scale for Prostate Cancer, Cancer Worry Scale-Revised, risk perception and knowledge. The results of the baseline questionnaire are presented. RESULTS: A total of 432 men completed questionnaires: 98 and 160 had mutations in BRCA1 and BRCA2 genes, respectively, and 174 were controls (familial mutation negative). Participants' perception of PCa risk was influenced by genetic status. Knowledge levels were high and unrelated to genetic status. Mean scores for the HADS and SF-36 were within reported general population norms and mean IES scores were within normal range. IES mean intrusion and avoidance scores were significantly higher in BRCA1/BRCA2 carriers than in controls and were higher in men with increased PCa risk perception. At the multivariate level, risk perception contributed more significantly to variance in IES scores than genetic status. CONCLUSION: This is the first study to report the psychosocial profile of men with BRCA1/BRCA2 mutations undergoing PCa screening. No clinically concerning levels of general or cancer-specific distress or poor quality of life were detected in the cohort as a whole. A small subset of participants reported higher levels of distress, suggesting the need for healthcare professionals offering PCa screening to identify these risk factors and offer additional information and support to men seeking PCa screening