GPX3 supports ovarian cancer tumor progression in vivo and promotes expression of GDF15.

OBJECTIVE: We previously reported that high expression of the extracellular glutathione peroxidase GPX3 is associated with poor patient outcome in ovarian serous adenocarcinomas, and that GPX3 protects ovarian cancer cells from oxidative stress in culture. Here we tested if GPX3 is necessary for tumor establishment in vivo and to identify novel downstream mediators of GPX3's pro-tumorigenic function. METHODS: GPX3 was knocked-down in ID8 ovarian cancer cells by shRNA to test the role of GPX3 in tumor establishment using a syngeneic IP xenograft model. RNA sequencing analysis was carried out in OVCAR3 cells following shRNA-mediated GPX3 knock-down to identify GPX3-dependent gene expression signatures. RESULTS: GPX3 knock-down abrogated clonogenicity and intraperitoneal tumor development in vivo, and the effects were dependent on the level of GPX3 knock-down. RNA sequencing showed that loss of GPX3 leads to decreased gene expression patterns related to pro-tumorigenic signaling pathways. Validation studies identified GDF15 as strongly dependent on GPX3. GDF15, a member of the TGF-ß growth factor family, has known oncogenic and immune modulatory activities. Similarly, GPX3 expression positively correlated with pro-tumor immune cell signatures, including regulatory T-cell and macrophage infiltration, and displayed significant correlation with PD-L1 expression. CONCLUSIONS: We show for the first time that tumor produced GPX3 is necessary for ovarian cancer growth in vivo and that it regulates expression of GDF15. The immune profile associated with GPX3 expression in serous ovarian tumors suggests that GPX3 may be an alternate marker of ovarian tumors susceptible to immune check-point inhibitors.

Longitudinal Changes in Fecal Calprotectin Levels Among Pregnant Women With and Without Inflammatory Bowel Disease and Their Babies.

BACKGROUND & AIMS: The effect of pregnancy on inflammatory bowel disease (IBD) remains poorly understood. We aimed to monitor intestinal inflammation using fecal calprotectin (FC) in pregnant women and their babies during early life. METHODS: Pregnant women with or without IBD and their infants were prospectively enrolled. FC levels were measured at each trimester of pregnancy and in babies throughout the first 3 years of life. Repeated-measures analysis was applied to investigate changes in FC levels while adjusting for confounders. The FC levels were correlated with the bacterial abundance in both mothers and babies. RESULTS: Six hundred and fourteen fecal samples from 358 mothers (98 with IBD) and 1005 fecal samples from 289 infants (76 born to IBD mothers) were analyzed. Pregnant Patients with IBD maintained higher FC levels through pregnancy compared with controls (P = 7.5 × 10-54). FC gradually increased in controls and declined in Patients with IBD throughout pregnancy (P for interaction = 5.8 × 10-7). Babies born to mothers with IBD presented with significantly higher FC levels than those born to controls up to 3 years of age, after adjusting for sex, delivery mode, feeding behavior, and antibiotics exposure (2 weeks to 3 months of age, P = .015; 12-36 months of age, P = .00003). Subdoligranulum, Roseburia, Fusicatenibacter, and Alistipes negatively correlated, and Streptococcus, Prevotella, Escherichia-Shigella, and Bifidobacterium positively correlated with maternal FC levels at T3. Faecalibacterium, Bifidobacterium, and Alistipes showed negative correlations, and Streptococcus were positively correlated with FC levels within 3 months of birth. CONCLUSIONS: Pregnancy is associated with decreased inflammatory activity in mothers with IBD. Higher FC levels in babies born to mothers with IBD suggest subclinical inflammation in early life, the long-term consequences of which are uncertain.

Genetic architecture of cardiometabolic risks in people living with HIV.

BACKGROUND: Advances in antiretroviral therapies have greatly improved the survival of people living with human immunodeficiency virus (HIV) infection (PLWH); yet, PLWH have a higher risk of cardiovascular disease than those without HIV. While numerous genetic loci have been linked to cardiometabolic risk in the general population, genetic predictors of the excessive risk in PLWH are largely unknown. METHODS: We screened for common and HIV-specific genetic variants associated with variation in lipid levels in 6284 PLWH (3095 European Americans [EA] and 3189 African Americans [AA]), from the Centers for AIDS Research Network of Integrated Clinical Systems cohort. Genetic hits found exclusively in the PLWH cohort were tested for association with other traits. We then assessed the predictive value of a series of polygenic risk scores (PRS) recapitulating the genetic burden for lipid levels, type 2 diabetes (T2D), and myocardial infarction (MI) in EA and AA PLWH. RESULTS: We confirmed the impact of previously reported lipid-related susceptibility loci in PLWH. Furthermore, we identified PLWH-specific variants in genes involved in immune cell regulation and previously linked to HIV control, body composition, smoking, and alcohol consumption. Moreover, PLWH at the top of European-based PRS for T2D distribution demonstrated a > 2-fold increased risk of T2D compared to the remaining 95% in EA PLWH but to a much lesser degree in AA. Importantly, while PRS for MI was not predictive of MI risk in AA PLWH, multiethnic PRS significantly improved risk stratification for T2D and MI. CONCLUSIONS: Our findings suggest that genetic loci involved in the regulation of the immune system and predisposition to risky behaviors contribute to dyslipidemia in the presence of HIV infection. Moreover, we demonstrate the utility of the European-based and multiethnic PRS for stratification of PLWH at a high risk of cardiometabolic diseases who may benefit from preventive therapies.

Nonsyndromic craniosynostosis: novel coding variants.

BACKGROUND: Craniosynostosis (CS), the premature fusion of one or more neurocranial sutures, is associated with approximately 200 syndromes; however, about 65-85% of patients present with no additional major birth defects. METHODS: We conducted targeted next-generation sequencing of 60 known syndromic and other candidate genes in patients with sagittal nonsyndromic CS (sNCS, n = 40) and coronal nonsyndromic CS (cNCS, n = 19). RESULTS: We identified 18 previously published and 5 novel pathogenic variants, including three de novo variants. Novel variants included a paternally inherited c.2209C>G:p.(Leu737Val) variant in BBS9 of a patient with cNCS. Common variants in BBS9, a gene required for ciliogenesis during cranial suture development, have been associated with sNCS risk in a previous genome-wide association study. We also identified c.313G>T:p.(Glu105*) variant in EFNB1 and c.435G>C:p.(Lys145Asn) variant in TWIST1, both in patients with cNCS. Mutations in EFNB1 and TWIST1 have been linked to craniofrontonasal and Saethre-Chotzen syndrome, respectively; both present with coronal CS. CONCLUSIONS: We provide additional evidence that variants in genes implicated in syndromic CS play a role in isolated CS, supporting their inclusion in genetic panels for screening patients with NCS. We also identified a novel BBS9 variant that further shows the potential involvement of BBS9 in the pathogenesis of CS.

GPX3 supports ovarian cancer tumor progression in vivo and promotes expression of GDF15.

Objective: We previously reported that high expression of the extracellular glutathione peroxidase GPX3 is associated with poor patient outcome in ovarian serous adenocarcinomas, and that GPX3 protects ovarian cancer cells from oxidative stress in culture. Here we tested if GPX3 is necessary for tumor establishment in vivo and to identify novel downstream mediators of GPX3's pro-tumorigenic function. Methods: GPX3 was knocked-down in ID8 ovarian cancer cells by shRNA to test the role of GPX3 in tumor establishment using a syngeneic IP xenograft model. RNA sequencing analysis was carried out in OVCAR3 cells following shRNA-mediated GPX3 knock-down to identify GPX3-dependent gene expression signatures. Results: GPX3 knock-down abrogated clonogenicity and intraperitoneal tumor development in vivo, and the effects were dependent on the level of GPX3 knock-down. RNA sequencing showed that loss of GPX3 leads to decreased gene expression patterns related to pro-tumorigenic signaling pathways. Validation studies identified GDF15 as strongly dependent on GPX3. GDF15, a member of the TGF-ß growth factor family, has known oncogenic and immune modulatory activities. Similarly, GPX3 expression positively correlated with pro-tumor immune cell signatures, including regulatory T-cell and macrophage infiltration, and displayed significant correlation with PD-L1 expression. Conclusions: We show for the first time that tumor produced GPX3 is necessary for ovarian cancer growth in vivo and that it regulates expression of GDF15. The immune profile associated with GPX3 expression in serous ovarian tumors suggests that GPX3 may be an alternate marker of ovarian tumors susceptible to immune check-point inhibitors.

Alternative splice variants of the mitochondrial fission protein DNM1L/Drp1 regulate mitochondrial dynamics and tumor progression in ovarian cancer.

Aberrant mitochondrial fission/fusion dynamics have been reported in cancer cells. While post translational modifications are known regulators of the mitochondrial fission/fusion machinery, we show that alternative splice variants of the fission protein Drp1 (DNM1L) have specific and unique roles in cancer, adding to the complexity of mitochondrial fission/fusion regulation in tumor cells. Ovarian cancer specimens express an alternative splice transcript variant of Drp1 lacking exon 16 of the variable domain, and high expression of this splice variant relative to other transcripts is associated with poor patient outcome. Unlike the full-length variant, expression of Drp1 lacking exon 16 leads to decreased association of Drp1 to mitochondrial fission sites, more fused mitochondrial networks, enhanced respiration, and TCA cycle metabolites, and is associated with a more metastatic phenotype in vitro and in vivo. These pro-tumorigenic effects can also be inhibited by specific siRNA-mediated inhibition of the endogenously expressed transcript lacking exon 16. Moreover, lack of exon 16 abrogates mitochondrial fission in response to pro-apoptotic stimuli and leads to decreased sensitivity to chemotherapeutics. These data emphasize the significance of the pathophysiological consequences of Drp1 alternative splicing and divergent functions of Drp1 splice variants, and strongly warrant consideration of Drp1 splicing in future studies.

A dietary intervention to improve the microbiome composition of pregnant women with Crohn's disease and their offspring: The MELODY (Modulating Early Life Microbiome through Dietary Intervention in Pregnancy) trial design.

Crohn's disease (CD), a type of inflammatory bowel disease (IBD), is a chronic condition of the gastrointestinal tract that is caused by the loss of mucosal tolerance towards the commensal bacteria resulting in inflammatory responses. It has long been postulated that the gut microbiota, a complex and dynamic population of microorganisms, plays a key role in the pathogenesis of IBD. Maternal diagnosis of IBD has been identified as the greatest risk factor for IBD in offspring increasing the odds of developing the disease >4.5-fold. Moreover, babies born to mothers with IBD have demonstrated reduced gut bacterial diversity. There is accumulating evidence that the early life microbiota colonization is informed by maternal diet within the 3rd trimester of pregnancy. While babies born to mothers with IBD would pose an ideal cohort for intervention, no primary prevention measures are currently available. Therefore, we designed the MELODY (Modulating Early Life Microbiome through Dietary Intervention in Pregnancy) trial to test whether the IBD-AID™ dietary intervention during the last trimester of pregnancy can beneficially shift the microbiome of CD patients and their babies, thereby promoting a strong, effective immune system during a critical time of the immune system development. We will also test if favorable changes in the microbiome can lead to a reduced risk of postpartum CD relapse and lower mucosal inflammation in the offspring. This study will help create new opportunities to foster a healthy microbiome in the offspring at high risk of other immune-mediated diseases, potentially reducing their risk later in life.

Mutations in GNAL cause primary torsion dystonia.

Dystonia is a movement disorder characterized by repetitive twisting muscle contractions and postures. Its molecular pathophysiology is poorly understood, in part owing to limited knowledge of the genetic basis of the disorder. Only three genes for primary torsion dystonia (PTD), TOR1A (DYT1), THAP1 (DYT6) and CIZ1 (ref. 5), have been identified. Using exome sequencing in two families with PTD, we identified a new causative gene, GNAL, with a nonsense mutation encoding p.Ser293* resulting in a premature stop codon in one family and a missense mutation encoding p.Val137Met in the other. Screening of GNAL in 39 families with PTD identified 6 additional new mutations in this gene. Impaired function of several of the mutants was shown by bioluminescence resonance energy transfer (BRET) assays.