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The diverse clinical phenotypes of Wolf–Hirschhorn syndrome (WHS) are the result of haploinsufficiency of several genes, one of which, LETM1 , encodes a protein of the mitochondrial inner membrane of uncertain function. Here, we show that LETM1 is associated with mitochondrial ribosomes, is required for mitochondrial DNA distribution and expression, and regulates the activity of an ancillary metabolic enzyme, pyruvate dehydrogenase. LETM1 deficiency in WHS alters mitochondrial morphology and DNA organization, as does substituting ketone bodies for glucose in control cells. While this change in nutrient availability leads to the death of fibroblasts with normal amounts of LETM1, WHS‐derived fibroblasts survive on ketone bodies, which can be attributed to their reduced dependence on glucose oxidation. Thus, remodeling of mitochondrial nucleoprotein complexes results from the inability of mitochondria to use specific substrates for energy production and is indicative of mitochondrial dysfunction. However, the dysfunction could be mitigated by a modified diet—for WHS, one high in lipids and low in carbohydrates. Synopsis The mitochondrial inner membrane protein LETM1 regulates mitochondrial DNA metabolism according to nutrient availability, which suggests that in the Wolf‐Hirschhorn syndrome and a range of other mitochondrial disorders, dietary control could impact disease development and progression. Nutrients configure mitochondrial nucleoprotein complexes for energy production; for glucose such adaptation is mediated by LETM1. LETM1 and pyruvate dehydrogenase (PDH) are physically associated with mitochondrial nucleoprotein complexes. Monoallelic deletion of LETM1 inactivates PDH and causes aggregation of mitochondrial nucleoids. LETM1 haploinsufficiency permits proliferation on a strict ketone body growth regime, whereas control cells undergo irreversible mitochondrial DNA aggregation and cell death. Mitochondrial translation and ribosome maintenance in human cells requires LETM1 when the organelles utilize glucose and pyruvate. Graphical Abstract The mitochondrial inner membrane protein LETM1 regulates mitochondrial DNA metabolism according to nutrient availability, which suggests that in the Wolf‐Hirschhorn syndrome and a range of other mitochondrial disorders, dietary control could impact disease development and progression.

Women with intrahepatic cholestasis of pregnancy (ICP) have hypercholanemia alongside an increased risk of dyslipidemia. We investigated how cholic acid (CA) supplementation in murine pregnancy impacts adipose tissue function. Mice were fed normal or 0.5% CA‐supplemented chow from identification of copulatory plug until gestational day 14 or 15 (n = 10–11/group) and were matched experimentally with nonpregnant mice (n = 7/group). Tissue weights were measured alongside plasma bile acids, glucose, lipids, reactive oxygen metabolites (ROM), and adipokines. Subcutaneous and gonadal adipocyte mRNA expression was evaluated. CA supplementation inhibited pregnancy‐associated adipose tissue expansion and decreased fetal weight. CA diet in pregnancy increased LDL‐cholesterol and reduced HDL‐cholesterol. Pregnancy and CA diet reduced lipid metabolism transcript expression in adipocytes. CA supplementation during pregnancy increased plasma ROM by 1.24‐fold and suppressed inflammatory‐modulating pentraxin‐2/3 and insulin‐like growth factor 1 (IGF‐1) levels by >50% and >80%, respectively. Together, we show that hypercholanemia disturbs pregnancy‐associated adipose tissue expansion and mRNA expression in late gestation concomitant with reduced IGF‐1, altered lipid availability and increased inflammation and oxidation, which could impact fetal growth. This work highlights the need to better understand adipose tissue and redox stress changes in ICP pregnancies and the potential implications for fetal health.

Abstract The long and very long chain polyunsaturated fatty acids (LC-PUFAs) are preferentially transported by the mother to the fetus. Failure to supply LC-PUFAs is strongly linked with stillbirth, fetal growth restriction, and impaired neurodevelopmental outcomes. However, dietary supplementation during pregnancy is unable to simply reverse these outcomes, suggesting imperfectly understood interactions between dietary fatty acid intake and the molecular mechanisms of maternal supply. Here we employ a comprehensive approach combining untargeted and targeted lipidomics with transcriptional profiling of maternal and fetal tissues in mouse pregnancy. Comparison of wild-type mice with genetic models of impaired lipid metabolism allows us to describe maternal hepatic adaptations required to provide LC-PUFAs to the developing fetus. A late pregnancy-specific, selective activation of the Liver X Receptor signalling pathway dramatically increases maternal supply of LC-PUFAs within circulating phospholipids. Crucially, genetic ablation of this pathway in the mother reduces LC-PUFA accumulation by the fetus, specifically of docosahexaenoic acid (DHA), a critical nutrient for brain development.

Mutations in nuclear-encoded protein subunits of the mitochondrial ribosome are an increasingly recognised cause of oxidative phosphorylation system (OXPHOS) disorders. Among them, mutations in the MRPL44 gene, encoding a structural protein of the large subunit of the mitochondrial ribosome, have been identified in four patients with OXPHOS defects and early-onset hypertrophic cardiomyopathy with or without additional clinical features. A 23-year-old individual with cardiac and skeletal myopathy, neurological involvement, and combined deficiency of OXPHOS complexes in skeletal muscle was clinically and genetically investigated. Analysis of whole-exome sequencing data revealed a homozygous mutation in MRPL44 (c.467 T > G), which was not present in the biological father, and a region of homozygosity involving most of chromosome 2, raising the possibility of uniparental disomy. Short-tandem repeat and genome-wide SNP microarray analyses of the family trio confirmed complete maternal uniparental isodisomy of chromosome 2. Mitochondrial ribosome assembly and mitochondrial translation were assessed in patient derived-fibroblasts. These studies confirmed that c.467 T > G affects the stability or assembly of the large subunit of the mitochondrial ribosome, leading to impaired mitochondrial protein synthesis and decreased levels of multiple OXPHOS components. This study provides evidence of complete maternal uniparental isodisomy of chromosome 2 in a patient with MRPL44 -related disease, and confirms that MRLP44 mutations cause a mitochondrial translation defect that may present as a multisystem disorder with neurological involvement.

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder affecting 0.5–2% of pregnancies. The majority of cases present in the third trimester with pruritus, elevated serum bile acids and abnormal serum liver tests. ICP is associated with an increased risk of adverse outcomes, including spontaneous preterm birth and stillbirth. Whilst rare mutations affecting hepatobiliary transporters contribute to the aetiology of ICP, the role of common genetic variation in ICP has not been systematically characterised to date. Here, we perform genome-wide association studies (GWAS) and meta-analyses for ICP across three studies including 1138 cases and 153,642 controls. Eleven loci achieve genome-wide significance and have been further investigated and fine-mapped using functional genomics approaches. Our results pinpoint common sequence variation in liver-enriched genes and liver-specific cis -regulatory elements as contributing mechanisms to ICP susceptibility. Investigation of variation in three cohorts has identified multiple genetic signals associated with the pregnancy-specific liver disorder, intrahepatic cholestasis of pregnancy, giving insight into the disease which can cause preterm birth and stillbirth.

Essential fatty acids (EFAs) and their derivatives, the long and very long chain polyunsaturated fatty acids (LC-PUFAs), are preferentially transported by the mother to the fetus. Failure to supply EFAs is strongly linked with stillbirth, fetal growth restriction, and impaired neurodevelopmental outcomes. However, dietary supplementation during pregnancy is unable to simply reverse these outcomes, suggesting imperfectly understood interactions between dietary EFA intake and the molecular mechanisms of maternal supply. Here we combine untargeted lipidomics with transcriptional profiling of healthy and genetically-manipulated murine models to understand the maternal adaptations required to provide LC-PUFAs to the developing fetus. We discovered a late pregnancy-specific, selective activation of the Liver X Receptor signalling pathway which dramatically increases maternal supply of LC-PUFAs within circulating phospholipids. Crucially, genetic ablation of this pathway in the mother reduced LC-PUFA accumulation by the fetus. Overall our work suggests new molecular strategies for improving maternal-fetal transfer of these important lipids.

University faculty members describe their collaborative projects with other faculty members, rsearchers, graduate students, professional educators, and other stakeholders in the educational enterprise. Through descriptions of several collaborative projects, the chapters explore some of the less explicitly articulated aspects of collaborative ventures. The authors use a variety of conceptual frameworks, derived from a number of disciplines including education and business, to deconstruct collaboration and to further undernstand its elements, issues, dynamics, and problematics. By confronting the challenges of building genuine and effective collaborative partnerships across institutions and cultures and by examining how the personal and the professional intertwine within the process, the book extends and deepens the dialogue about such partnerships. Collaboration is presented as a deeply personal and professionally challenging enterprise that offers satisfaction and enrichment when it is undertaken with eyes and minds wide open.

Outcomes for children with relapsed and refractory neuroblastoma are dismal. The combination of irinotecan and temozolomide has activity in these patients, and its acceptable toxicity profile makes it an excellent backbone for study of new agents. We aimed to test the addition of temsirolimus or dinutuximab to irinotecan–temozolomide in patients with relapsed or refractory neuroblastoma. For this open-label, randomised, phase 2 selection design trial of the Children's Oncology Group (COG; ANBL1221), patients had to have histological verification of neuroblastoma or ganglioneuroblastoma at diagnosis or have tumour cells in bone marrow with increased urinary catecholamine concentrations at diagnosis. Patients of any age were eligible at first designation of relapse or progression, or first designation of refractory disease, provided organ function requirements were met. Patients previously treated for refractory or relapsed disease were ineligible. Computer-based randomisation with sequence generation defined by permuted block randomisation (block size two) was used to randomly assign patients (1:1) to irinotecan and temozolomide plus either temsirolimus or dinutuximab, stratified by disease category, previous exposure to anti-GD2 antibody therapy, and tumour MYCN amplification status. Patients in both groups received oral temozolomide (100 mg/m2 per dose) and intravenous irinotecan (50 mg/m2 per dose) on days 1–5 of 21-day cycles. Patients in the temsirolimus group also received intravenous temsirolimus (35 mg/m2 per dose) on days 1 and 8, whereas those in the dinutuximab group received intravenous dinutuximab (17·5 mg/m2 per day or 25 mg/m2 per day) on days 2–5 plus granulocyte macrophage colony-stimulating factor (250 μg/m2 per dose) subcutaneously on days 6–12. Patients were given up to a maximum of 17 cycles of treatment. The primary endpoint was the proportion of patients achieving an objective (complete or partial) response by central review after six cycles of treatment, analysed by intention to treat. Patients, families, and those administering treatment were aware of group assignment. This study is registered with ClinicalTrials.gov, number NCT01767194, and follow-up of the initial cohort is ongoing. Between Feb 22, 2013, and March 23, 2015, 36 patients from 27 COG member institutions were enrolled on this groupwide study. One patient was ineligible (alanine aminotransferase concentration was above the required range). Of the remaining 35 patients, 18 were randomly assigned to irinotecan–temozolomide–temsirolimus and 17 to irinotecan–temozolomide–dinutuximab. Median follow-up was 1·26 years (IQR 0·68–1·61) among all eligible participants. Of the 18 patients assigned to irinotecan–temozolomide–temsirolimus, one patient (6%; 95% CI 0·0–16·1) achieved a partial response. Of the 17 patients assigned to irinotecan–temozolomide–dinutuximab, nine (53%; 95% CI 29·2–76·7) had objective responses, including four partial responses and five complete responses. The most common grade 3 or worse adverse events in the temsirolimus group were neutropenia (eight [44%] of 18 patients), anaemia (six [33%]), thrombocytopenia (five [28%]), increased alanine aminotransferase (five [28%]), and hypokalaemia (four [22%]). One of the 17 patients assigned to the dinutuximab group refused treatment after randomisation; the most common grade 3 or worse adverse events in the remaining 16 patients evaluable for safety were pain (seven [44%] of 16), hypokalaemia (six [38%]), neutropenia (four [25%]), thrombocytopenia (four [25%]), anaemia (four [25%]), fever and infection (four [25%]), and hypoxia (four [25%]); one patient had grade 4 hypoxia related to therapy that met protocol-defined criteria for unacceptable toxicity. No deaths attributed to protocol therapy occurred. Irinotecan–temozolomide–dinutuximab met protocol-defined criteria for selection as the combination meriting further study whereas irinotecan–temozolomide–temsirolimus did not. Irinotecan–temozolomide–dinutuximab shows notable anti-tumour activity in patients with relapsed or refractory neuroblastoma. Further evaluation of biomarkers in a larger cohort of patients might identify those most likely to respond to this chemoimmunotherapeutic regimen. National Cancer Institute.

A phase 3 randomized study (COG ANBL0032) demonstrated significantly improved outcome by adding immunotherapy with ch14.18 antibody to isotretinoin as post-consolidation therapy for high-risk neuroblastoma (NB). This study, ANBL0931, was designed to collect FDA-required safety/toxicity data to support FDA registration of ch14.18. Newly diagnosed high-risk NB patients who achieved at least a partial response to induction therapy and received myeloablative consolidation with stem cell rescue were enrolled to receive six courses of isotretinoin with five concomitant cycles of ch14.18 combined with GM-CSF or IL2. Ch14.18 infusion time was 10-20 h per dose. Blood was collected for cytokine analysis and its association with toxicities and outcome. Of 105 patients enrolled, five patients developed protocol-defined unacceptable toxicities. The most common grade ≥ 3 non-hematologic toxicities of immunotherapy for cycles 1-5, respectively, were neuropathic pain (41, 28, 22, 31, 24%), hypotension (10, 17, 4, 14, 8%), allergic reactions (ARs) (3, 10, 5, 7, 2%), capillary leak syndrome (1, 4, 0, 2, 0%), and fever (21, 59, 6, 32, 5%). The 3-year event-free survival and overall survival were 67.6 ± 4.8% and 79.1 ± 4.2%, respectively. AR during course 1 was associated with elevated serum levels of IL-1Ra and IFNγ, while severe hypotension during this course was associated with low IL5 and nitrate. Higher pretreatment CXCL9 level was associated with poorer event-free survival (EFS). This study has confirmed the significant, but manageable treatment-related toxicities of this immunotherapy and identified possible cytokine biomarkers associated with select toxicities and outcome. EFS and OS appear similar to that previously reported on ANBL0032.