SLCO5A1 and synaptic assembly genes contribute to impulsivity in juvenile myoclonic epilepsy

Elevated impulsivity is a key component of attention-deficit hyperactivity disorder (ADHD), bipolar disorder and juvenile myoclonic epilepsy (JME). We performed a genome-wide association, colocalization, polygenic risk score, and pathway analysis of impulsivity in JME (n = 381). Results were followed up with functional characterisation using a drosophila model. We identified genome-wide associated SNPs at 8q13.3 (P = 7.5 × 10-9) and 10p11.21 (P = 3.6 × 10-8). The 8q13.3 locus colocalizes with SLCO5A1 expression quantitative trait loci in cerebral cortex (P = 9.5 × 10-3). SLCO5A1 codes for an organic anion transporter and upregulates synapse assembly/organisation genes. Pathway analysis demonstrates 12.7-fold enrichment for presynaptic membrane assembly genes (P = 0.0005) and 14.3-fold enrichment for presynaptic organisation genes (P = 0.0005) including NLGN1 and PTPRD. RNAi knockdown of Oatp30B, the Drosophila polypeptide with the highest homology to SLCO5A1, causes over-reactive startling behaviour (P = 8.7 × 10-3) and increased seizure-like events (P = 6.8 × 10-7). Polygenic risk score for ADHD genetically correlates with impulsivity scores in JME (P = 1.60 × 10-3). SLCO5A1 loss-of-function represents an impulsivity and seizure mechanism. Synaptic assembly genes may inform the aetiology of impulsivity in health and disease.

The 3D chromatin landscape of rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a pediatric soft tissue cancer with a lack of precision therapy options for patients. We hypothesized that with a general paucity of known mutations in RMS, chromatin structural driving mechanisms are essential for tumor proliferation. Thus, we carried out high-depth in situ Hi-C in representative cell lines and patient-derived xenografts (PDXs) to define chromatin architecture in each major RMS subtype. We report a comprehensive 3D chromatin structural analysis and characterization of fusion-positive (FP-RMS) and fusion-negative RMS (FN-RMS). We have generated spike-in in situ Hi-C chromatin interaction maps for the most common FP-RMS and FN-RMS cell lines and compared our data with PDX models. In our studies, we uncover common and distinct structural elements in large Mb-scale chromatin compartments, tumor-essential genes within variable topologically associating domains and unique patterns of structural variation. Our high-depth chromatin interactivity maps and comprehensive analyses provide context for gene regulatory events and reveal functional chromatin domains in RMS.

The Association of Global and Disease-Related Stress With Susceptibility to and Use of E-Cigarettes and Marijuana Among Adolescents With Congenital Heart Disease

OBJECTIVE

Adolescents with congenital heart disease (CHD) are exposed to disease-related stressors and have elevated risk for cardiovascular and cognitive complications that are exacerbated by e-cigarettes and marijuana. The aims of this cross-sectional study are to: (1) identify the association between perceived global and disease-related stress and susceptibility to e-cigarettes and marijuana, (2) determine if the association between stress and susceptibility differs by gender, and (3) explore the association between stress and ever use of e-cigarettes and marijuana among adolescents with CHD.

METHODS

Adolescents with CHD (N = 98; aged 12-18 years) completed self-report measures of susceptibility to/ever use of e-cigarettes and marijuana and global and disease-related stress.

RESULTS

Susceptibility to e-cigarettes and marijuana was reported by 31.3% and 40.2% of adolescents, respectively. Ever use of e-cigarettes and marijuana was reported by 15.3% and 14.3% of adolescents, respectively. Global stress was associated with susceptibility to and ever use of e-cigarettes and marijuana. Disease-related stress was associated with susceptibility to marijuana. Females reported more global and disease-related stress than males, but the association of stress with susceptibility to e-cigarettes and marijuana did not differ by gender.

CONCLUSIONS

Susceptibility to e-cigarettes and marijuana is common among adolescents with CHD and is associated with stress. Future work to examine the longitudinal associations between susceptibility, stress, and use of e-cigarettes and marijuana is warranted. Global stress may be an important consideration in the development of strategies to prevent these risky health behaviors among adolescents with CHD.

A Randomized Clinical Trial Demonstrating Feasibility and Preliminary Efficacy of a Videoconference-Delivered Physical Activity Lifestyle Intervention Among Adolescents With a Congenital Heart Defect

BACKGROUND

Individuals with congenital heart defects are at increased risk for developing further cardiovascular complications, which can be mitigated by increasing physical activity. Given that positive health behaviors begin declining during older adolescence, it is vital to promote lifestyle changes in this population.

PURPOSE

The current study aims to (a) determine the feasibility/acceptability of the Congenital Heart Disease Physical Activity Lifestyle (CHD-PAL) intervention among adolescents (ages 15-18) with moderate and complex congenital heart defects, and (b) estimate the preliminary efficacy of CHD-PAL for increasing time spent in moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness and decreasing sedentary behavior.

METHODS

Eligible participants were randomized into either CHD-PAL (eight 30-min videoconferencing sessions over 20 weeks with an interventionist + Fitbit + exercise prescription) or a comparator (Fitbit + exercise prescription).

RESULTS

Sixty adolescents were randomized (76% recruitment rate; 94% of participants were retained from baseline to follow-up). Most adolescents (73%) and their parents/guardians (76%) reported that the trial was enjoyable. While there was no effect of arm on change in MVPA, sedentary behavior, or cardiorespiratory fitness for the entire sample, among those who engaged in <21 min of MVPA on average at baseline, adolescents in the CHD-PAL intervention had an increase of 16 min/day of MVPA more than comparators (d = 0.90).

CONCLUSIONS

The CHD-PAL intervention warrants examination in a larger trial to establish efficacy among those adolescents with a congenital heart defect who engage in <21 min of MVPA/day and should include follow-up assessments to examine effect durability.

CLINICAL TRIALS REGISTRATION

NCT03335475.

Spatially resolved in silico modeling of NKG2D signaling kinetics suggests a key role of NKG2D and Vav1 Co-clustering in generating natural killer cell activation

Natural Killer (NK) cells provide key resistance against viral infections and tumors. A diverse set of activating and inhibitory NK cell receptors (NKRs) interact with cognate ligands presented by target host cells, where integration of dueling signals initiated by the ligand-NKR interactions determines NK cell activation or tolerance. Imaging experiments over decades have shown micron and sub-micron scale spatial clustering of activating and inhibitory NKRs. The mechanistic roles of these clusters in affecting downstream signaling and activation are often unclear. To this end, we developed a predictive in silico framework by combining spatially resolved mechanistic agent based modeling, published TIRF imaging data, and parameter estimation to determine mechanisms by which formation and spatial movements of activating NKG2D microclusters affect early time NKG2D signaling kinetics in a human cell line NKL. We show co-clustering of NKG2D and the guanosine nucleotide exchange factor Vav1 in NKG2D microclusters plays a dominant role over ligand (ULBP3) rebinding in increasing production of phospho-Vav1(pVav1), an activation marker of early NKG2D signaling. The in silico model successfully predicts several scenarios of inhibition of NKG2D signaling and time course of NKG2D spatial clustering over a short (~3 min) interval. Modeling shows the presence of a spatial positive feedback relating formation and centripetal movements of NKG2D microclusters, and pVav1 production offers flexibility towards suppression of activating signals by inhibitory KIR ligands organized in inhomogeneous spatial patterns (e.g., a ring). Our in silico framework marks a major improvement in developing spatiotemporal signaling models with quantitatively estimated model parameters using imaging data.

Natural Killer cells are lymphocytes of our innate immunity and provide important resistance against viral infections and tumors. NK cells scan the local environment with diverse activating and inhibitory NK cell receptors (NKRs) and remain tolerized or lyse target cells expressing cognate ligands to NKRs. NKRs have been found to form micron sized clusters (or microclusters) as they interact with cognate ligands, and mechanisms regarding how the formation and movements of these microclusters influence NK cell signaling and activation, specifically related to activating NKRs, are often unclear. To this end, we develop a predictive spatially resolved early-time NK cell signaling model to study the interplay between membrane-proximal biochemical signaling events and the kinetics of microclusters of activating NKG2D and inhibitory KIR2DL2 receptors. We used published TIRF imaging data to validate our in silico models and estimate model parameters. Predictions from multiple in silico models are tested against a variety of data obtained from published imaging experiments and immunoassays. Our analysis suggests co-clustering of NKG2D and the guanosine nucleotide exchange factor Vav1 in the microclusters plays a major role in enhancing downstream activating signals. The developed framework can be extended to describe spatiotemporal signaling for other activating NKRs including CD16.