Case-case genome-wide association analysis identifying genetic loci with divergent effects on Crohn's disease and ulcerative colitis

The Eating Disorders Genetics Initiative 2 (EDGI2): study protocol

BACKGROUND

The Eating Disorders Genetics Initiative 2 (EDGI2) is designed to explore the role of genes and environment in anorexia nervosa, bulimia nervosa, binge-eating disorder, and avoidant/restrictive food intake disorder (ARFID) with a focus on broad population representation and severe and/or longstanding illness.

METHODS

A total of 20,000 new participants (18,700 cases and 1,300 controls) will be ascertained from the United States (US), Mexico (MX), Australia (AU), Aotearoa New Zealand (NZ), Sweden (SE), and Denmark (DK). Comprehensive phenotyping and genotyping will be performed for participants in US, MX, AU, NZ, and SE using the EDGI2 questionnaire battery and participant saliva samples. In DK, case identification and genotyping will be through the National Patient Register and bloodspots archived near birth. Case-control and case-case genome-wide association studies will be conducted within EDGI2 and enhanced via meta-analysis with external data from the Eating Disorders Working Group of the Psychiatric Genomics Consortium (PGC-ED). Additional analyses will explore genetic correlations between eating disorders (EDs) and other psychiatric and metabolic traits, calculate polygenic risk scores (PRS), and leverage functional biology to evaluate clinical outcomes. Moreover, analyzing PRS for patient stratification and linking identified risk loci to clinically relevant phenotypes highlight the potential of EDGI2 for clinical translation.

DISCUSSION

EDGI2 is a global expansion of the EDGI study to increase sample size, increase participant representation across multiple ancestral backgrounds, and to include ARFID. ED genetics research has historically lagged behind other psychiatric disorders, and EDGI2 is designed to rapidly advance the study of the genetics of the major EDs. Exploring EDs at both the diagnostic level and the symptom level will provide an unprecedented look at the genetic architecture underlying EDs.

TRIAL REGISTRATION

EDGI2 is a registered clinical trial: clinicaltrials.gov NCT06594913. https://clinicaltrials.gov/study/NCT06594913 (posted September 19, 2024).

Deubiquitinase OTUD3: a double-edged sword in immunity and disease

Deubiquitination is an important form of post-translational modification that regulates protein homeostasis. Ovarian tumor domain-containing proteins (OTUDs) subfamily member OTUD3 was identified as a deubiquitinating enzyme involved in the regulation of various physiological processes such as immunity and inflammation. Disturbances in these physiological processes trigger diseases in humans and animals, such as cancer, neurodegenerative diseases, diabetes, mastitis, etc. OTUD3 is aberrantly expressed in tumors and is a double-edged sword, exerting tumor-promoting or anti-tumor effects in different types of tumors affecting cancer cell proliferation, metastasis, and metabolism. OTUD3 is regulated at the transcriptional level by a number of MicroRNAs, such as miR-520h, miR-32, and miR101-3p. In addition, OTUD3 is regulated by a number of post-translational modifications, such as acetylation and ubiquitination. Therefore, understanding the regulatory mechanisms of OTUD3 expression can help provide insight into its function in human immunity and disease, offering the possibility of its use as a therapeutic target to diagnose or treat disease.

Diverse targets of SMN2-directed splicing-modulating small molecule therapeutics for spinal muscular atrophy

Designing an RNA-interacting molecule that displays high therapeutic efficacy while retaining specificity within a broad concentration range remains a challenging task. Risdiplam is an FDA-approved small molecule for the treatment of spinal muscular atrophy (SMA), the leading genetic cause of infant mortality. Branaplam is another small molecule which has undergone clinical trials. The therapeutic merit of both compounds is based on their ability to restore body-wide inclusion of Survival Motor Neuron 2 (SMN2) exon 7 upon oral administration. Here we compare the transcriptome-wide off-target effects of these compounds in SMA patient cells. We captured concentration-dependent compound-specific changes, including aberrant expression of genes associated with DNA replication, cell cycle, RNA metabolism, cell signaling and metabolic pathways. Both compounds triggered massive perturbations of splicing events, inducing off-target exon inclusion, exon skipping, intron retention, intron removal and alternative splice site usage. Our results of minigenes expressed in HeLa cells provide mechanistic insights into how these molecules targeted towards a single gene produce different off-target effects. We show the advantages of combined treatments with low doses of risdiplam and branaplam. Our findings are instructive for devising better dosing regimens as well as for developing the next generation of small molecule therapeutics aimed at splicing modulation.