Genetic Determined Iron Starvation Signature in Friedreich's Ataxia.

BACKGROUND: Early studies in cellular models suggested an iron accumulation in Friedreich's ataxia (FA), yet findings from patients are lacking. OBJECTIVES: The objective is to characterize systemic iron metabolism, body iron storages, and intracellular iron regulation in FA patients. METHODS: In FA patients and matched healthy controls, we assessed serum iron parameters, regulatory hormones as well as the expression of regulatory proteins and iron distribution in peripheral blood mononuclear cells (PBMCs). We applied magnetic resonance imaging with R2*-relaxometry to quantify iron storages in the liver, spleen, and pancreas. Across all evaluations, we assessed the influence of the genetic severity as expressed by the length of the shorter GAA-expansion (GAA1). RESULTS: We recruited 40 FA patients (19 women). Compared to controls, FA patients displayed lower serum iron and transferrin saturation. Serum ferritin, hepcidin, mean corpuscular hemoglobin and mean corpuscular volume in FA inversely correlated with the GAA1-repeat length, indicating iron deficiency and restricted availability for erythropoiesis with increasing genetic severity. R2*-relaxometry revealed a reduction of splenic and hepatic iron stores in FA. Liver and spleen R2* values inversely correlated with the GAA1-repeat length. FA PBMCs displayed downregulation of ferritin and upregulation of transferrin receptor and divalent metal transporter-1 mRNA, particularly in patients with >500 GAA1-repeats. In FA PBMCs, intracellular iron was not increased, but shifted toward mitochondria. CONCLUSIONS: We provide evidence for a previously unrecognized iron starvation signature at systemic and cellular levels in FA patients, which is related to the underlying genetic severity. These findings challenge the use of systemic iron lowering therapies in FA. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Dopamine­iron homeostasis interaction rescues mitochondrial fitness in Parkinson's disease.

Imbalances of iron and dopamine metabolism along with mitochondrial dysfunction have been linked to the pathogenesis of Parkinson's disease (PD). We have previously suggested a direct link between iron homeostasis and dopamine metabolism, as dopamine can increase cellular uptake of iron into macrophages thereby promoting oxidative stress responses. In this study, we investigated the interplay between iron, dopamine, and mitochondrial activity in neuroblastoma SH-SY5Y cells and human induced pluripotent stem cell (hiPSC)-derived dopaminergic neurons differentiated from a healthy control and a PD patient with a mutation in the α-synuclein (SNCA) gene. In SH-SY5Y cells, dopamine treatment resulted in increased expression of the transmembrane iron transporters transferrin receptor 1 (TFR1), ferroportin (FPN), and mitoferrin2 (MFRN2) and intracellular iron accumulation, suggesting that dopamine may promote iron uptake. Furthermore, dopamine supplementation led to reduced mitochondrial fitness including decreased mitochondrial respiration, increased cytochrome c control efficiency, reduced mtDNA copy number and citrate synthase activity, increased oxidative stress and impaired aconitase activity. In dopaminergic neurons derived from a healthy control individual, dopamine showed comparable effects as observed in SH-SY5Y cells. The hiPSC-derived PD neurons harboring an endogenous SNCA mutation demonstrated altered mitochondrial iron homeostasis, reduced mitochondrial capacity along with increased oxidative stress and alterations of tricarboxylic acid cycle linked metabolic pathways compared with control neurons. Importantly, dopamine treatment of PD neurons promoted a rescue effect by increasing mitochondrial respiration, activating antioxidant stress response, and normalizing altered metabolite levels linked to mitochondrial function. These observations provide evidence that dopamine affects iron homeostasis, intracellular stress responses and mitochondrial function in healthy cells, while dopamine supplementation can restore the disturbed regulatory network in PD cells.

Comparative analysis of oral and intravenous iron therapy in rat models of inflammatory anemia and iron deficiency.

Anemia is a major health issue and associated with increased morbidity. Iron deficiency anemia (IDA) is the most prevalent, followed by anemia of chronic disease (ACD). IDA and ACD often co-exist, challenging diagnosis and treatment. While iron supplementation is the first-line therapy for IDA, its optimal route of administration and the efficacy of different repletion strategies in ACD are elusive. Female Lewis rats were injected with group A streptococcal peptidoglycan-polysaccharide (PG-APS) to induce inflammatory arthritis with associated ACD and/or repeatedly phlebotomized and fed with a low iron diet to induce IDA, or a combination thereof (ACD/IDA). Iron was either supplemented by daily oral gavage of ferric maltol or by weekly intravenous (i.v.) injection of ferric carboxymaltose for up to 4 weeks. While both strategies reversed IDA, they remained ineffective to improve hemoglobin (Hb) levels in ACD, although oral iron showed slight amelioration of various erythropoiesis-associated parameters. In contrast, both iron treatments significantly increased Hb in ACD/IDA. In ACD and ACD/IDA animals, i.v. iron administration resulted in iron trapping in liver and splenic macrophages, induction of ferritin expression and increased circulating levels of the iron hormone hepcidin and the inflammatory cytokine interleukin-6, while oral iron supplementation reduced interleukin-6 levels. Thus, oral and i.v. iron resulted in divergent effects on systemic and tissue iron homeostasis and inflammation. Our results indicate that both iron supplements improve Hb in ACD/IDA, but are ineffective in ACD with pronounced inflammation, and that under the latter condition, i.v. iron is trapped in macrophages and may enhance inflammation.

Mitochondrial Respiration in Response to Iron Deficiency Anemia: Comparison of Peripheral Blood Mononuclear Cells and Liver.

Iron is an essential component for metabolic processes, including oxygen transport within hemoglobin, tricarboxylic acid (TCA) cycle activity, and mitochondrial energy transformation. Iron deficiency can thus lead to metabolic dysfunction and eventually result in iron deficiency anemia (IDA), which affects approximately 1.5 billion people worldwide. Using a rat model of IDA induced by phlebotomy, we studied the effects of IDA on mitochondrial respiration in peripheral blood mononuclear cells (PBMCs) and the liver. Furthermore, we evaluated whether the mitochondrial function evaluated by high-resolution respirometry in PBMCs reflects corresponding alterations in the liver. Surprisingly, mitochondrial respiratory capacity was increased in PBMCs from rats with IDA compared to the controls. In contrast, mitochondrial respiration remained unaffected in livers from IDA rats. Of note, citrate synthase activity indicated an increased mitochondrial density in PBMCs, whereas it remained unchanged in the liver, partly explaining the different responses of mitochondrial respiration in PBMCs and the liver. Taken together, these results indicate that mitochondrial function determined in PBMCs cannot serve as a valid surrogate for respiration in the liver. Metabolic adaptions to iron deficiency resulted in different metabolic reprogramming in the blood cells and liver tissue.

Dietary Iron Overload and Hfe-/- Related Hemochromatosis Alter Hepatic Mitochondrial Function.

Iron is an essential co-factor for many cellular metabolic processes, and mitochondria are main sites of utilization. Iron accumulation promotes production of reactive oxygen species (ROS) via the catalytic activity of iron species. Herein, we investigated the consequences of dietary and genetic iron overload on mitochondrial function. C57BL/6N wildtype and Hfe-/- mice, the latter a genetic hemochromatosis model, received either normal diet (ND) or high iron diet (HI) for two weeks. Liver mitochondrial respiration was measured using high-resolution respirometry along with analysis of expression of specific proteins and ROS production. HI promoted tissue iron accumulation and slightly affected mitochondrial function in wildtype mice. Hepatic mitochondrial function was impaired in Hfe-/- mice on ND and HI. Compared to wildtype mice, Hfe-/- mice on ND showed increased mitochondrial respiratory capacity. Hfe-/- mice on HI showed very high liver iron levels, decreased mitochondrial respiratory capacity and increased ROS production associated with reduced mitochondrial aconitase activity. Although Hfe-/- resulted in increased mitochondrial iron loading, the concentration of metabolically reactive cytoplasmic iron and mitochondrial density remained unchanged. Our data show multiple effects of dietary and genetic iron loading on mitochondrial function and linked metabolic pathways, providing an explanation for fatigue in iron-overloaded hemochromatosis patients, and suggests iron reduction therapy for improvement of mitochondrial function.

Breast cancer characteristics and surgery among women with Li-Fraumeni syndrome in Germany-A retrospective cohort study.

BACKGROUND: Women with Li-Fraumeni syndrome (LFS) have elevated breast cancer (BC) risk. Optimal BC treatment strategies in this population are yet unknown. METHODS: BC subtypes and treatment were retrospectively investigated between December 2016 and January 2019 in a multicentre study. BC risks were evaluated according to the type of surgery. RESULTS: Thirty-five women of our study population (35/44; 79.5%) had developed 36 breast lesions at first diagnosis at a mean age of 34 years. Those breast lesions comprised 32 invasive BCs (89%), three ductal carcinoma in situ alone (8%) and one malignant phyllodes tumour (3%). BCs were mainly high-grade (18/32), of no special type (NST; 31/32), HER2-enriched (11/32) or luminal-B-(like)-type (10/32). Affected women (n = 35) received breast-conserving surgery (BCS, n = 17) or a mastectomy (ME, n = 18) including seven women with simultaneous contralateral prophylactic mastectomy (CPM) at first diagnosis. Nineteen women suffered 20 breast or locoregional axillary lesions at second diagnosis with mean age of 36. Median time between first and second diagnosis was 57 months; median time to contra- and ipsilateral recurrence depended on surgical strategies (BCS: 46 vs. unilateral ME: 93 vs. bilateral ME > 140 months). Women with a primary treatment of solitaire therapeutic ME suffered from contralateral BC earlier compared to those with therapeutic ME and CPM (median: 93 vs. >140 months). CONCLUSION: Aggressive BC subtypes occur among women with LFS. Surgical treatment, i.e. ME and CPM, may prolong time to a second BC diagnosis. Conclusion on long-term survival benefit is pending. Individual competing tumour risks and long-term outcomes need to be taken into consideration.

Cytokine-Mediated Regulation of ARG1 in Macrophages and Its Impact on the Control of Salmonella enterica Serovar Typhimurium Infection.

Arginase 1 (ARG1) is a cytosolic enzyme that cleaves L-arginine, the substrate of inducible nitric oxide synthase (iNOS), and thereby impairs the control of various intracellular pathogens. Herein, we investigated the role of ARG1 during infection with Salmonella enterica serovar Typhimurium (S.tm). To study the impact of ARG1 on Salmonella infections in vitro, bone marrow-derived macrophages (BMDM) from C57BL/6N wild-type, ARG1-deficient Tie2Cre+/-ARG1fl/fl and NRAMPG169 C57BL/6N mice were infected with S.tm. In wild-type BMDM, ARG1 was induced by S.tm and further upregulated by the addition of interleukin (IL)-4, whereas interferon-γ had an inhibitory effect. Deletion of ARG1 did not result in a reduction in bacterial numbers. In vivo, Arg1 mRNA was upregulated in the spleen, but not in the liver of C57BL/6N mice following intraperitoneal S.tm infection. The genetic deletion of ARG1 (Tie2Cre+/-ARG1fl/fl) or its pharmacological inhibition with CB-1158 neither affected the numbers of S.tm in spleen, liver and blood nor the expression of host response genes such as iNOS, IL-6 or tumour necrosis factor (TNF). Furthermore, ARG1 was dispensable for pathogen control irrespective of the presence or absence of the phagolysosomal natural resistance-associated macrophage protein 1 (NRAMP1). Thus, unlike the detrimental function of ARG1 seen during infections with other intraphagosomal microorganisms, ARG1 did not support bacterial survival in systemic salmonellosis, indicating differential roles of arginine metabolism for host immune response and microbe persistence depending on the type of pathogen.

PALLD mutation in a European family conveys a stromal predisposition for familial pancreatic cancer.

BACKGROUNDPancreatic cancer is one of the deadliest cancers, with low long-term survival rates. Despite recent advances in treatment, it is important to identify and screen high-risk individuals for cancer prevention. Familial pancreatic cancer (FPC) accounts for 4%-10% of pancreatic cancers. Several germline mutations are related to an increased risk and might offer screening and therapy options. In this study, we aimed to identity of a susceptibility gene in a family with FPC.METHODSWhole exome sequencing and PCR confirmation was performed on the surgical specimen and peripheral blood of an index patient and her sister in a family with high incidence of pancreatic cancer, to identify somatic and germline mutations associated with familial pancreatic cancer. Compartment-specific gene expression data and immunohistochemistry were also queried.RESULTSThe identical germline mutation of the PALLD gene (NM_001166108.1:c.G154A:p.D52N) was detected in the index patient with pancreatic cancer and the tumor tissue of her sister. Whole genome sequencing showed similar somatic mutation patterns between the 2 sisters. Apart from the PALLD mutation, commonly mutated genes that characterize pancreatic ductal adenocarcinoma were found in both tumor samples. However, the 2 patients harbored different somatic KRAS mutations (G12D and G12V). Healthy siblings did not have the PALLD mutation, indicating a disease-specific impact. Compartment-specific gene expression data and IHC showed expression in cancer-associated fibroblasts (CAFs).CONCLUSIONWe identified a germline mutation of the palladin (PALLD) gene in 2 siblings in Europe, affected by familial pancreatic cancer, with a significant overexpression in CAFs, suggesting that stromal palladin could play a role in the development, maintenance, and/or progression of pancreatic cancer.FUNDINGDFG SFB 1321.

Gallstones, Body Mass Index, C-Reactive Protein, and Gallbladder Cancer: Mendelian Randomization Analysis of Chilean and European Genotype Data.

BACKGROUND AND AIMS: Gallbladder cancer (GBC) is a neglected disease with substantial geographical variability: Chile shows the highest incidence worldwide, while GBC is relatively rare in Europe. Here, we investigate the causal effects of risk factors considered in current GBC prevention programs as well as C-reactive protein (CRP) level as a marker of chronic inflammation. APPROACH AND RESULTS: We applied two-sample Mendelian randomization (MR) using publicly available data and our own data from a retrospective Chilean and a prospective European study. Causality was assessed by inverse variance weighted (IVW), MR-Egger regression, and weighted median estimates complemented with sensitivity analyses on potential heterogeneity and pleiotropy, two-step MR, and mediation analysis. We found evidence for a causal effect of gallstone disease on GBC risk in Chileans (P = 9 × 10-5 ) and Europeans (P = 9 × 10-5 ). A genetically elevated body mass index (BMI) increased GBC risk in Chileans (P = 0.03), while higher CRP concentrations increased GBC risk in Europeans (P = 4.1 × 10-6 ). European results suggest causal effects of BMI on gallstone disease (P = 0.008); public Chilean data were not, however, available to enable assessment of the mediation effects among causal GBC risk factors. CONCLUSIONS: Two risk factors considered in the current Chilean program for GBC prevention are causally linked to GBC risk: gallstones and BMI. For Europeans, BMI showed a causal effect on gallstone risk, which was itself causally linked to GBC risk.

Chemotherapy of Locally Advanced or Metastatic Urothelial Cell Carcinoma: Monocentric Real-Life Data.

BACKGROUND/AIM: Up to 30% of all patients will present with an advanced or a metastatic stage (mUCC) at the moment of the initial diagnosis of urothelial cell carcinoma of the bladder (UCC). We investigated the numbers, the efficacy and toxicity of different chemotherapies for mUCC in daily practice and "real-life" conditions and evaluated them substance-specifically. PATIENTS AND METHODS: All patients with a mUCC, who were treated between January 1, 2006 and October 31, 2016 at the Department of Urology and Pediatric Urology at University Hospital Marburg (Germany), were retrospectively analyzed. We set the focus on demographic and tumor-specific data as well as on effectiveness, therapy sequences, and drug tolerance. RESULTS: Forty-one patients were identified. Of the 41 patients, 85.4% of the patients in first-line therapy received gemcitabine/cisplatin. A large proportion of 85.4% received a second-line therapy and 40% a third-line therapy due to progress or relapse. Median overall survival (mOS) was 18 months including all patients and increased up to 29.5 months in the cases of three therapy lines. CONCLUSION: Our data reveal that chemotherapy of mUCC is effective and side effects are manageable in daily clinical practice.

Cancer surveillance and distress among adult pathogenic TP53 germline variant carriers in Germany: A multicenter feasibility and acceptance survey.

BACKGROUND: Li-Fraumeni syndrome (LFS) is a high-risk cancer predisposition syndrome caused by pathogenic germline variants of TP53. Cancer surveillance has noted a significant survival advantage in individuals with LFS; however, little is known about the feasibility, acceptance, and psychosocial effects of such a program. METHODS: Pathogenic TP53 germline variant carriers completed a 7-part questionnaire evaluating sociodemographics, cancer history, surveillance participation, reasons for nonadherence, worries, and distress adapted from the Cancer Worry Scale. Counselees' common concerns and suggestions were assessed in MAXQDA Analytics Pro 12. RESULTS: Forty-nine participants (46 females and 3 males), aged 40.0 ± 12.6 years, formed the study population; 43 (88%) had a personal cancer history (including multiple cancers in 10 [20%]). Forty-three individuals participated (88%) in surveillance during the study or formerly. Willingness to undergo surveillance was influenced by satisfaction with genetic testing and counseling (P = .019 [Fisher-Yates test]) but not by sociodemographics, cancer history, or distress level. Almost one-third of the participants reported logistical difficulties in implementing surveillance because of the high frequency of medical visits, scheduling difficulties, and the travel distance to their surveillance providers. Self-reported distress and perceived emotional burden for family members and partners were moderate (median for self-reported distress, 3.3; median for perceived emotional burden, 3.0). For both, the interquartile range was moderate to very high (2.7-3.7 and 3.0-3.7, respectively). CONCLUSIONS: Individuals with LFS require efficient counseling as well as an accessible, well-organized, interdisciplinary, standardized surveillance program to increase adherence and psychological coping.

Myeloproliferative Diseases as Possible Risk Factor for Development of Chronic Thromboembolic Pulmonary Hypertension-A Genetic Study.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease which is often caused by recurrent emboli. These are also frequently found in patients with myeloproliferative diseases. While myeloproliferative diseases can be caused by gene defects, the genetic predisposition to CTEPH is largely unexplored. Therefore, the objective of this study was to analyse these genes and further genes involved in pulmonary hypertension in CTEPH patients. A systematic screening was conducted for pathogenic variants using a gene panel based on next generation sequencing. CTEPH was diagnosed according to current guidelines. In this study, out of 40 CTEPH patients 4 (10%) carried pathogenic variants. One patient had a nonsense variant (c.2071A>T p.Lys691*) in the BMPR2 gene and three further patients carried the same pathogenic variant (missense variant, c.1849G>T p.Val617Phe) in the Janus kinase 2 (JAK2) gene. The latter led to a myeloproliferative disease in each patient. The prevalence of this JAK2 variant was significantly higher than expected (p < 0.0001). CTEPH patients may have a genetic predisposition more often than previously thought. The predisposition for myeloproliferative diseases could be an additional risk factor for CTEPH development. Thus, clinical screening for myeloproliferative diseases and genetic testing may be considered also for CTEPH patients.

ABCB1/4 gallbladder cancer risk variants identified in India also show strong effects in Chileans.

BACKGROUND: The first large-scale genome-wide association study of gallbladder cancer (GBC) recently identified and validated three susceptibility variants in the ABCB1 and ABCB4 genes for individuals of Indian descent. We investigated whether these variants were also associated with GBC risk in Chileans, who show the highest incidence of GBC worldwide, and in Europeans with a low GBC incidence. METHODS: This population-based study analysed genotype data from retrospective Chilean case-control (255 cases, 2042 controls) and prospective European cohort (108 cases, 181 controls) samples consistently with the original publication. RESULTS: Our results confirmed the reported associations for Chileans with similar risk effects. Particularly strong associations (per-allele odds ratios close to 2) were observed for Chileans with high Native American (=Mapuche) ancestry. No associations were noticed for Europeans, but the statistical power was low. CONCLUSION: Taking full advantage of genetic and ethnic differences in GBC risk may improve the efficiency of current prevention programs.

An Animal Model Further Uncovers the Role of Mutant BrafV600E during Papillary Thyroid Cancer Development.

Papillary thyroid carcinomas (PTCs) account for 90% of human thyroid cancer cases, which represent 1% of all cancer cases. They are likely to develop from papillary thyroid microcarcinomas (PTMCs), found in up to 36% of healthy individuals, due to rare progression events (0.01%). Although the prognosis of PTCs is excellent, 5% to 10% of tumors display an unfavorable outcome. About 45% of PTCs exhibit activating BRAFV600E mutations. Rats of the inbred BD strains postnatally exposed to the carcinogen N-ethyl-N-nitrosourea developed PTMCs, which closely resembled their human counterparts judging from their histology, size, and marginal tendency to progress. DNA sequencing revealed mutations in exon 15 of the Braf gene identical to the human BRAFV600E mutation in 82% of the cases. Predominantly a 50:50 ratio of wild-type to mutant Braf alleles was seen regardless of tumor size or animal age, indicating that the Braf mutation is an early, if not the initial, event in rat PTMC development. Surprisingly, most PTMCs carrying a confirmed BrafV600E mutation did not display BrafV600E protein expression. As the BrafV600Egene is supposed to be the driver in PTC development, down-regulation of expression should contribute to the low risk for progression of PTMC. This model system will enable further insights into the molecular mechanisms of PTMC initiation and progression to PTC, further translating into targeted tumor prevention strategies/therapies.

Breast cancer risk in BRCA1/2 mutation carriers and noncarriers under prospective intensified surveillance.

Comparably little is known about breast cancer (BC) risks in women from families tested negative for BRCA1/2 mutations despite an indicative family history, as opposed to BRCA1/2 mutation carriers. We determined the age-dependent risks of first and contralateral breast cancer (FBC, CBC) both in noncarriers and carriers of BRCA1/2 mutations, who participated in an intensified breast imaging surveillance program. The study was conducted between January 1, 2005, and September 30, 2017, at 12 university centers of the German Consortium for Hereditary Breast and Ovarian Cancer. Two cohorts were prospectively followed up for incident FBC (n = 4,380; 16,398 person-years [PY], median baseline age: 39 years) and CBC (n = 2,993; 10,090 PY, median baseline age: 42 years). Cumulative FBC risk at age 60 was 61.8% (95% CI 52.8-70.9%) for BRCA1 mutation carriers, 43.2% (95% CI 32.1-56.3%) for BRCA2 mutation carriers and 15.7% (95% CI 11.9-20.4%) for noncarriers. FBC risks were significantly higher than in the general population, with incidence rate ratios of 23.9 (95% CI 18.9-29.8) for BRCA1 mutation carriers, 13.5 (95% CI 9.2-19.1) for BRCA2 mutation carriers and 4.9 (95% CI 3.8-6.3) for BRCA1/2 noncarriers. Cumulative CBC risk 10 years after FBC was 25.1% (95% CI 19.6-31.9%) for BRCA1 mutation carriers, 6.6% (95% CI 3.4-12.5%) for BRCA2 mutation carriers and 3.6% (95% CI 2.2-5.7%) for noncarriers. CBC risk in noncarriers was similar to women with unilateral BC from the general population. Further studies are needed to confirm whether less intensified surveillance is justified in women from BRCA1/2 negative families with elevated risk.

Reduced Right Ventricular Output Reserve in Patients With Systemic Sclerosis and Mildly Elevated Pulmonary Artery Pressure.

OBJECTIVE: This prospective study was undertaken to evaluate right ventricular function and pulmonary arterial compliance (PAC; ratio of stroke volume to pulse pressure) at rest and during exercise in patients with systemic sclerosis (SSc) with normal mean pulmonary artery pressure (PAP), patients with SSc with mildly elevated mean PAP, and patients with SSc with manifest pulmonary hypertension (PH). METHODS: Patients with SSc (n = 112) underwent clinical assessment and right-sided heart catheterization at rest and during exercise and were divided into 3 groups according to their resting mean PAP values: normal mean PAP (≤20 mm Hg), mildly elevated mean PAP (21-24 mm Hg), and PH (mean PAP ≥25 mm Hg). Results were compared between groups by analysis of variance followed by post hoc Student's t-test. RESULTS: Compared to patients with normal mean PAP, patients with mildly elevated mean PAP had a lower 6-minute walking distance (P = 0.008), lower cardiac index (P = 0.027) and higher pulmonary vascular resistance (P = 0.0002) during exercise, and lower PAC at rest (P = 0.016) and different stages of exercise (P = 0.033 for 25W and P = 0.024 for 75W). CONCLUSION: The results of this study suggest that impaired 6-minute walking distance in SSc patients with mildly elevated mean PAP might be caused by reduced PAC during exercise and reduced right ventricular output reserve, presumably due to impaired coupling between the right ventricle and the pulmonary vasculature. These findings provide further evidence of the clinical relevance of mildly elevated mean PAP in patients with SSc.

A direct regulatory link between microRNA-137 and SHANK2: implications for neuropsychiatric disorders.

BACKGROUND: Mutations in the SHANK genes, which encode postsynaptic scaffolding proteins, have been linked to a spectrum of neurodevelopmental disorders. The SHANK genes and the schizophrenia-associated microRNA-137 show convergence on several levels, as they are both expressed at the synapse, influence neuronal development, and have a strong link to neurodevelopmental and neuropsychiatric disorders like intellectual disability, autism, and schizophrenia. This compiled evidence raised the question if the SHANKs might be targets of miR-137. METHODS: In silico analysis revealed a putative binding site for microRNA-137 (miR-137) in the SHANK2 3'UTR, while this was not the case for SHANK1 and SHANK3. Luciferase reporter assays were performed by overexpressing wild type and mutated SHANK2-3'UTR and miR-137 in human neuroblastoma cells and mouse primary hippocampal neurons. miR-137 was also overexpressed or inhibited in hippocampal neurons, and Shank2 expression was analyzed by quantitative real-time PCR and Western blot. Additionally, expression levels of experimentally validated miR-137 target genes were analyzed in the dorsolateral prefrontal cortex (DLPFC) of schizophrenia and control individuals using the RNA-Seq data from the CommonMind Consortium. RESULTS: miR-137 directly targets the 3'UTR of SHANK2 in a site-specific manner. Overexpression of miR-137 in mouse primary hippocampal neurons significantly lowered endogenous Shank2 protein levels without detectable influence on mRNA levels. Conversely, miR-137 inhibition increased Shank2 protein expression, indicating that miR-137 regulates SHANK2 expression by repressing protein translation rather than inducing mRNA degradation. To find out if the miR-137 signaling network is altered in schizophrenia, we compared miR-137 precursor and miR-137 target gene expression in the DLPFC of schizophrenia and control individuals using the CommonMind Consortium RNA sequencing data. Differential expression of 23% (16/69) of known miR-137 target genes was detected in the DLPFC of schizophrenia individuals compared with controls. We propose that in further targets (e.g., SHANK2, as described in this paper) which are not regulated on RNA level, effects may only be detectable on protein level. CONCLUSION: Our study provides evidence that a direct regulatory link exists between miR-137 and SHANK2 and supports the finding that miR-137 signaling might be altered in schizophrenia.

Subtypes of Native American ancestry and leading causes of death: Mapuche ancestry-specific associations with gallbladder cancer risk in Chile.

Latin Americans are highly heterogeneous regarding the type of Native American ancestry. Consideration of specific associations with common diseases may lead to substantial advances in unraveling of disease etiology and disease prevention. Here we investigate possible associations between the type of Native American ancestry and leading causes of death. After an aggregate-data study based on genome-wide genotype data from 1805 admixed Chileans and 639,789 deaths, we validate an identified association with gallbladder cancer relying on individual data from 64 gallbladder cancer patients, with and without a family history, and 170 healthy controls. Native American proportions were markedly underestimated when the two main types of Native American ancestry in Chile, originated from the Mapuche and Aymara indigenous peoples, were combined together. Consideration of the type of Native American ancestry was crucial to identify disease associations. Native American ancestry showed no association with gallbladder cancer mortality (P = 0.26). By contrast, each 1% increase in the Mapuche proportion represented a 3.7% increased mortality risk by gallbladder cancer (95%CI 3.1-4.3%, P = 6×10-27). Individual-data results and extensive sensitivity analyses confirmed the association between Mapuche ancestry and gallbladder cancer. Increasing Mapuche proportions were also associated with an increased mortality due to asthma and, interestingly, with a decreased mortality by diabetes. The mortality due to skin, bladder, larynx, bronchus and lung cancers increased with increasing Aymara proportions. Described methods should be considered in future studies on human population genetics and human health. Complementary individual-based studies are needed to apportion the genetic and non-genetic components of associations identified relying on aggregate-data.

Familial breast cancer: Genetic counseling over time, including patients´ expectations and initiators considering the Angelina Jolie effect.

PURPOSE: The German Consortium for hereditary breast/ovarian cancer (GC-HBOC) aims for nationwide access to professional, individualized yet structured care for families at high risk. The identification of such families remains key for optimal care. Our study evaluates counselees' characteristics, referral practices, expectations and motivations in respect to their first genetic consultation. The impact of the Angelina Jolie Effect (AJE) was prospectively assessed. METHODS: All counselees could participate through a questionnaire. Groups were built in respect to neoadjuvant chemotherapy (FT) and before/after AJE. RESULTS: The 917 (88.5%) counselees (FT: 8.2%) were on average female (97.3%), with a mean age of 44.6, had children (71.9%), higher education (88%), personal (46.4%) or at least one first-degree relative (74.6%) with BC/OC or known BRCA1/2 mutation (11.8%), were in a relationship (76.1%), and living in a village (40.7%). The AJE is associated with significantly fewer cancelations (p = 0.005), more attendance among men (4.2% vs. 0.8%, p = 0.002), and people with familial BRCA1/2 (14.8% vs. 7.5%, p = 0.003). The majority seek information regarding their cancer risk (83%) or relatives' risk (74.8%), HBOC (69.1%), and surveillance programs for themselves (66.6%) or relatives (60.6%). CONCLUSION: Enhanced media awareness of genetic cancer motivates patients, including other patient groups. A higher number of participants, including more men, are attending GC due to the AJE. In terms of the rising complexity of genetic testing, the analysis of patients' expectations and initiators for GC suggests that there is an urgent need to develop to participate motivation analysis. The factors revealed as impediments to accessing GC-HBOC guide recommendations to optimize access to genetic counseling. Medical educational programs for primary gynecologists and families at risk might be options to reach more participants.