2024
Daryadel, A. ; Küng, C.J. ; Haykir, B. ; Sabrautzki, S. ; Hrabě de Angelis, M. ; Hernando, N. ; Rubio-Aliaga, I. ; Wagner, C.A.
Am. J. Physiol.-Renal Physiol. 326, F792-F801 (2024)
The kidney controls systemic inorganic phosphate (Pi) levels by adapting reabsorption to Pi intake. Renal Pi reabsorption is mostly mediated by sodium-phosphate cotransporters NaPi-IIa (SLC34A1) and NaPi-IIc (SLC34A3) which are tightly controlled by various hormones including parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23). PTH and FGF23 rise in response to Pi intake and decrease NaPi-IIa and NaPi-IIc brush border membrane abundance enhancing phosphaturia. Phosphaturia and transporter regulation occur even in the absence of PTH and FGF23 signalling. The calcium-sensing receptor (CaSR) regulates PTH and FGF23 secretion, and may also directly affect renal Pi handling. Here, we combined pharmacological and genetic approaches to examine the role of the CaSR in the acute phosphaturic response to Pi-loading. Animals pretreated with the calcimimetic cinacalcet were hyperphosphatemic, had blunted PTH levels upon Pi administration, a reduced Pi-induced phosphaturia and no Pi-induced NaPi-IIa downregulation. The calcilytic NPS-2143 exaggerated the PTH response to Pi-loading but did not abolish Pi-induced downregulation of NaPi-IIa. In mice with a dominant inactivating mutation in the Casr (CasrBCH002), baseline NaPi-IIa expression was higher, whereas downregulation of transporter expression was blunted in double CasrBCH002/PTH KO transgenic animals. Thus, in response to an acute Pi load, acute modulation of the CaSR affects the endocrine and renal response, while chronic genetic inactivation, displays only subtle differences in the downregulation of NaPi-IIa and NaPi-IIc renal expression. We did not find evidence that the CaSR impacts on the acute renal response to oral Pi-loading beyond its role in regulating PTH secretion.
Wissenschaftlicher Artikel
Scientific Article
Geist, D. ; Hönes, G.S. ; Grund, S.C. ; Pape, J. ; Siemes, D. ; Spangenberg, P. ; Tolstik, E. ; Dörr, S. ; Spielmann, N. ; Fuchs, H. ; Gailus-Durner, V. ; Hrabě de Angelis, M. ; Mittag, J. ; Engel, D.R. ; Führer, D. ; Lorenz, K. ; Moeller, L.C.
Thyroid, DOI: 10.1089/thy.2023.0683 (2024)
BACKGROUND: Stimulation of ventricular hypertrophy and heart rate are two major cardiac effects of thyroid hormone (TH). Aim of this study was to determine in vivo which TH receptor (TR), α or β, and which mode of TR action, canonical gene expression or DNA binding independent noncanonical action, mediate these effects. MATERIAL AND METHODS: We compared global TRα and TRβ knockout mice (TRαKO; TRβKO) with wild-type (WT) mice to determine the TR isoform responsible for T3 effects. The relevance of TR DNA binding was studied in mice with a mutation in the DNA-binding domain that selectively abrogates DNA binding and canonical TR action (TRαGS; TRβGS). Hearts were studied with echocardiography at baseline and after seven weeks T3 treatment. Gene expression was measured with real-time PCR. Heart rate was recorded with radiotelemetry transmitters for seven weeks in untreated, hypothyroid and T3-treated mice. RESULTS: T3 induced ventricular hypertrophy in WT and TRβKO mice, but not in TRαKO mice. Hypertrophy was also induced in TRαGS mice. Thus, hypertrophy is mostly mediated by noncanonical TRα action. Similarly, repression of Mhy7 occurred in WT and TRαGS mice. Basal heart rate was largely dependent on canonical TRα action. But responsiveness to hypothyroidism and T3 treatment as well as expression of pacemaker gene Hcn2 were still preserved in TRαKO mice, demonstrating that TRβ could compensate for absence of TRα. CONCLUSION: T3-induced cardiac hypertrophy could be attributed to noncanonical TRα action, whereas heart rate regulation was mediated by canonical TRα action. TRβ could substitute for canonical, but not noncanonical TRα action.
Wissenschaftlicher Artikel
Scientific Article
Giusti, S.A. ; Pino, N. ; Pannunzio, C. ; Ogando, M.B. ; Armando, N.G. ; Garrett, L. ; Zimprich, A. ; Becker, L. ; Gimeno, M.L. ; Lukin, J. ; Merino, F.L. ; Pardi, M.B. ; Pedroncini, O. ; Di Mauro, G.C. ; Gailus-Durner, V. ; Fuchs, H. ; Hrabě de Angelis, M. ; Patop, I.L. ; Turck, C.W. ; Deussing, J.M. ; Vogt Weisenhorn, D.M. ; Jahn, O. ; Kadener, S. ; Hölter, S.M. ; Brose, N. ; Giesert, F. ; Wurst, W. ; Marin-Burgin, A. ; Refojo, D.
Sci. Adv. 10:eadj8769 (2024)
Circular RNAs (circRNAs) are a large class of noncoding RNAs. Despite the identification of thousands of circular transcripts, the biological significance of most of them remains unexplored, partly because of the lack of effective methods for generating loss-of-function animal models. In this study, we focused on circTulp4, an abundant circRNA derived from the Tulp4 gene that is enriched in the brain and synaptic compartments. By creating a circTulp4-deficient mouse model, in which we mutated the splice acceptor site responsible for generating circTulp4 without affecting the linear mRNA or protein levels, we were able to conduct a comprehensive phenotypic analysis. Our results demonstrate that circTulp4 is critical in regulating neuronal and brain physiology, modulating the strength of excitatory neurotransmission and sensitivity to aversive stimuli. This study provides evidence that circRNAs can regulate biologically relevant functions in neurons, with modulatory effects at multiple levels of the phenotype, establishing a proof of principle for the regulatory role of circRNAs in neural processes.
Wissenschaftlicher Artikel
Scientific Article
Harada, M. ; Han, S. ; Shi, M. ; Yu, S. ; Adam, J. ; Adamski, J. ; Scheerer, M.F. ; Neschen, S. ; Hrabě de Angelis, M. ; Wang-Sattler, R.
Int. J. Biol. Macromol. 265:130962 (2024)
Combining a Sodium-Glucose-Cotransporter-2-inhibitor (SGLT2i) with metformin is recommended for managing hyperglycemia in patients with type 2 diabetes (T2D) who have cardio-renal complications. Our study aimed to investigate the metabolic effects of SGLT2i and metformin, both individually and synergistically. We treated leptin receptor-deficient (db/db) mice with these drugs for two weeks and conducted metabolite profiling, identifying 861 metabolites across kidney, liver, muscle, fat, and plasma. Using linear regression and mixed-effects models, we identified two SGLT2i-specific metabolites, X-12465 and 3-hydroxybutyric acid (3HBA), a ketone body, across all examined tissues. The levels of 3HBA were significantly higher under SGLT2i monotherapy compared to controls and were attenuated when combined with metformin. We observed similar modulatory effects on metabolites involved in protein catabolism (e.g., branched-chain amino acids) and gluconeogenesis. Moreover, combination therapy significantly raised pipecolate levels, which may enhance mTOR1 activity, while modulating GSK3, a common target of SGLT2i and 3HBA inhibition. The combination therapy also led to significant reductions in body weight and lactate levels, contrasted with monotherapies. Our findings advocate for the combined approach to better manage muscle loss, and the risks of DKA and lactic acidosis, presenting a more effective strategy for T2D treatment.
Wissenschaftlicher Artikel
Scientific Article
Harada, M. ; Adam, J. ; Covic, M. ; Brandmaier, S. ; Muschet, C. ; Huang, J. ; Han, S. ; Rommel, M. ; Rotter, M. ; Heier, M. ; Mohney, R.P. ; Krumsiek, J. ; Kastenmüller, G. ; Rathmann, W. ; Zou, Z. ; Zukunft, S. ; Scheerer, M.F. ; Neschen, S. ; Adamski, J. ; Gieger, C. ; Peters, A. ; Ankerst, D.P. ; Meitinger, T. ; Alderete, T.L. ; Hrabě de Angelis, M. ; Suhre, K. ; Wang-Sattler, R.
Cardiovasc. Diabetol. 23:199 (2024)
BACKGROUND: Metformin and sodium-glucose-cotransporter-2 inhibitors (SGLT2i) are cornerstone therapies for managing hyperglycemia in diabetes. However, their detailed impacts on metabolic processes, particularly within the citric acid (TCA) cycle and its anaplerotic pathways, remain unclear. This study investigates the tissue-specific metabolic effects of metformin, both as a monotherapy and in combination with SGLT2i, on the TCA cycle and associated anaplerotic reactions in both mice and humans. METHODS: Metformin-specific metabolic changes were initially identified by comparing metformin-treated diabetic mice (MET) with vehicle-treated db/db mice (VG). These findings were then assessed in two human cohorts (KORA and QBB) and a longitudinal KORA study of metformin-naïve patients with Type 2 Diabetes (T2D). We also compared MET with db/db mice on combination therapy (SGLT2i + MET). Metabolic profiling analyzed 716 metabolites from plasma, liver, and kidney tissues post-treatment, using linear regression and Bonferroni correction for statistical analysis, complemented by pathway analyses to explore the pathophysiological implications. RESULTS: Metformin monotherapy significantly upregulated TCA cycle intermediates such as malate, fumarate, and α-ketoglutarate (α-KG) in plasma, and anaplerotic substrates including hepatic glutamate and renal 2-hydroxyglutarate (2-HG) in diabetic mice. Downregulated hepatic taurine was also observed. The addition of SGLT2i, however, reversed these effects, such as downregulating circulating malate and α-KG, and hepatic glutamate and renal 2-HG, but upregulated hepatic taurine. In human T2D patients on metformin therapy, significant systemic alterations in metabolites were observed, including increased malate but decreased citrulline. The bidirectional modulation of TCA cycle intermediates in mice influenced key anaplerotic pathways linked to glutaminolysis, tumorigenesis, immune regulation, and antioxidative responses. CONCLUSION: This study elucidates the specific metabolic consequences of metformin and SGLT2i on the TCA cycle, reflecting potential impacts on the immune system. Metformin shows promise for its anti-inflammatory properties, while the addition of SGLT2i may provide liver protection in conditions like metabolic dysfunction-associated steatotic liver disease (MASLD). These observations underscore the importance of personalized treatment strategies.
Wissenschaftlicher Artikel
Scientific Article
Jiang, S. ; Yuan, T. ; Rosenberger, F.A. ; Mourier, A. ; Dragano, N.R.V. ; Kremer, L. ; Rubalcava-Gracia, D. ; Hansen, F.M. ; Borg, M. ; Mennuni, M. ; Filograna, R. ; Alsina, D. ; Misic, J. ; Koolmeister, C. ; Papadea, P. ; Hrabě de Angelis, M. ; Ren, L. ; Andersson, O. ; Unger, A. ; Bergbrede, T. ; Di Lucrezia, R. ; Wibom, R. ; Zierath, J.R. ; Krook, A. ; Giavalisco, P. ; Mann, M. ; Larsson, N.G.
Nat. Metab., 29 (2024)
The oxidative phosphorylation system1 in mammalian mitochondria plays a key role in transducing energy from ingested nutrients2. Mitochondrial metabolism is dynamic and can be reprogrammed to support both catabolic and anabolic reactions, depending on physiological demands or disease states. Rewiring of mitochondrial metabolism is intricately linked to metabolic diseases and promotes tumour growth3–5. Here, we demonstrate that oral treatment with an inhibitor of mitochondrial transcription (IMT)6 shifts whole-animal metabolism towards fatty acid oxidation, which, in turn, leads to rapid normalization of body weight, reversal of hepatosteatosis and restoration of normal glucose tolerance in male mice on a high-fat diet. Paradoxically, the IMT treatment causes a severe reduction of oxidative phosphorylation capacity concomitant with marked upregulation of fatty acid oxidation in the liver, as determined by proteomics and metabolomics analyses. The IMT treatment leads to a marked reduction of complex I, the main dehydrogenase feeding electrons into the ubiquinone (Q) pool, whereas the levels of electron transfer flavoprotein dehydrogenase and other dehydrogenases connected to the Q pool are increased. This rewiring of metabolism caused by reduced mtDNA expression in the liver provides a principle for drug treatment of obesity and obesity-related pathology.
Wissenschaftlicher Artikel
Scientific Article
Küng, C.J. ; Daryadel, A. ; Fuente, R. ; Haykir, B. ; Hrabě de Angelis, M. ; Hernando, N. ; Rubio-Aliaga, I. ; Wagner, C.A.
Pflugers Arch. 476, 833-845 (2024)
The Calcium-sensing receptor (CaSR) senses extracellular calcium, regulates parathyroid hormone (PTH) secretion, and has additional functions in various organs related to systemic and local calcium and mineral homeostasis. Familial hypocalciuric hypercalcemia type I (FHH1) is caused by heterozygous loss-of-function mutations in the CaSR gene, and is characterized by the combination of hypercalcemia, hypocalciuria, normal to elevated PTH, and facultatively hypermagnesemia and mild bone mineralization defects. To date, only heterozygous Casr null mice have been available as model for FHH1. Here we present a novel mouse FHH1 model identified in a large ENU-screen that carries an c.2579 T > A (p.Ile859Asn) variant in the Casr gene (CasrBCH002 mice). In order to dissect direct effects of the genetic variant from PTH-dependent effects, we crossed CasrBCH002 mice with PTH deficient mice. Heterozygous CasrBCH002 mice were fertile, had normal growth and body weight, were hypercalcemic and hypermagnesemic with inappropriately normal PTH levels and urinary calcium excretion replicating some features of FHH1. Hypercalcemia and hypermagnesemia were independent from PTH and correlated with higher expression of claudin 16 and 19 in kidneys. Likewise, reduced expression of the renal TRPM6 channel in CasrBCH002 mice was not dependent on PTH. In bone, mutations in Casr rescued the bone phenotype observed in Pth null mice by increasing osteoclast numbers and improving the columnar pattern of chondrocytes in the growth zone. In summary, CasrBCH002 mice represent a new model to study FHH1 and our results indicate that only a part of the phenotype is driven by PTH.
Wissenschaftlicher Artikel
Scientific Article
Leu, C.-L. ; Lam, D. ; Salminen, A.V. ; Wefers, B. ; Becker, L. ; Garrett, L. ; Rozman, J. ; Wurst, W. ; Hrabě de Angelis, M. ; Hölter, S.M. ; Winkelmann, J. ; Williams, R.H.
Sleep 47:zsae015 (2024)
Restless legs syndrome (RLS) is a neurological disorder characterized by uncomfortable or unpleasant sensations in the legs during rest periods. To relieve these sensations, patients move their legs, causing sleep disruption. While the pathogenesis of RLS has yet to be resolved, there is a strong genetic association to the MEIS1 gene. A missense variant in MEIS1 is enriched 7-fold in RLS patients compared to non-affected individuals. We generated a mouse line carrying this mutation (p.Arg272His/c.815G>A), referred to herein as Meis1R272H/R272H (Meis1 point mutation), to determine whether it would phenotypically resemble RLS. As women are more prone to RLS, driven partly by an increased risk of developing RLS during pregnancy, we focussed on female homozygous mice. We evaluated RLS-related outcomes, particularly sensorimotor behavior and sleep, in young and aged mice. Compared to non-carrier littermates, homozygous mice displayed very few differences. Significant hyperactivity occurred before the lights-on (rest) period in aged female mice, reflecting the age-dependent incidence of RLS. Sensory experiments involving tactile feedback (rotorod, wheel running, and hotplate) were only marginally different. Overall, RLS-like phenomena were not recapitulated except for the increased wake activity prior to rest. This is likely due to the focus on young mice. Nevertheless, the Meis1R272H mouse line is a potentially useful RLS model, carrying a clinically relevant variant and showing an age-dependent phenotype.
Wissenschaftlicher Artikel
Scientific Article
Ouni, M. ; Kovác, L. ; Gancheva, S. ; Jähnert, M. ; Zuljan, E. ; Gottmann, P. ; Kahl, S. ; Hrabě de Angelis, M. ; Roden, M. ; Schürmann, A.
Obesity 32, 363-375 (2024)
Objective: The aim of this study was to discover novel markers underlying the improvement of skeletal muscle metabolism after bariatric surgery. Methods: Skeletal muscle transcriptome data of lean people and people with obesity, before and 1 year after bariatric surgery, were subjected to weighted gene co-expression network analysis (WGCNA) and least absolute shrinkage and selection operator (LASSO) regression. Results of LASSO were confirmed in a replication cohort. Results: The expression levels of 440 genes differing between individuals with and without obesity were no longer different 1 year after surgery, indicating restoration. WGCNA clustered 116 genes with normalized expression in one major module, particularly correlating to weight loss and decreased plasma free fatty acids (FFA), 44 of which showed an obesity-related phenotype upon deletion in mice. Among the genes of the major module, 105 represented prominent markers for reduced FFA concentration, including 55 marker genes for decreased BMI in both the discovery and replication cohorts. Conclusions: Previously unknown gene networks and marker genes underlined the important role of FFA in restoring muscle gene expression after bariatric surgery and further suggest novel therapeutic targets for obesity.
Wissenschaftlicher Artikel
Scientific Article
Sabikunnahar, B. ; Caldwell, S. ; Varnum, S. ; Hogan, T. ; Lahue, K.G. ; Rathkolb, B. ; Gerlini, R. ; Dragano, N.R.V. ; Aguilar-Pimentel, J.A. ; Irmler, M. ; Sanz-Moreno, A. ; da Silva Buttkus, P. ; Beckers, J. ; Wolf, E. ; Gailus-Durner, V. ; Fuchs, H. ; Hrabě de Angelis, M. ; Ather, J.L. ; Poynter, M.E. ; Krementsov, D.N.
Physiol. Rep. 12:e15901 (2024)
Obesity is a global health problem characterized by excessive fat accumulation, driven by adipogenesis and lipid accumulation. Long non-coding RNAs (lncRNAs) have recently been implicated in regulating adipogenesis and adipose tissue function. Mouse lncRNA U90926 was previously identified as a repressor of in vitro adipogenesis in 3T3-L1 preadipocytes. Consequently, we hypothesized that, in vivo, U90926 may repress adipogenesis, and hence its deletion would increase weight gain and adiposity. We tested the hypothesis by applying U90926-deficient (U9-KO) mice to a high-throughput phenotyping pipeline. Compared with WT, U9-KO mice showed no major differences across a wide range of behavioral, neurological, and other physiological parameters. In mice fed a standard diet, we have found no differences in obesity-related phenotypes, including weight gain, fat mass, and plasma concentrations of glucose, insulin, triglycerides, and free fatty acids, in U9-KO mice compared to WT. U90926 deficiency lacked a major effect on white adipose tissue morphology and gene expression profile. Furthermore, in mice fed a high-fat diet, we found increased expression of U90926 in adipose tissue stromal vascular cell fraction, yet observed no effect of U90926 deficiency on weight gain, fat mass, adipogenesis marker expression, and immune cell infiltration into the adipose tissue. These data suggest that the U90926 lacks an essential role in obesity-related phenotypes and adipose tissue biology in vivo.
Wissenschaftlicher Artikel
Scientific Article
Tollot-Wegner, M. ; Jessen, M. ; Kim, K. ; Sanz-Moreno, A. ; Spielmann, N. ; Gailus-Durner, V. ; Fuchs, H. ; Hrabě de Angelis, M. ; von Eyss, B.
Breast Cancer Res. 26:74 (2024)
The transcription factor TRPS1 is a context-dependent oncogene in breast cancer. In the mammary gland, TRPS1 activity is restricted to the luminal population and is critical during puberty and pregnancy. Its function in the resting state remains however unclear. To evaluate whether it could be a target for cancer therapy, we investigated TRPS1 function in the healthy adult mammary gland using a conditional ubiquitous depletion mouse model where long-term depletion does not affect fitness. Using transcriptomic approaches, flow cytometry and functional assays, we show that TRPS1 activity is essential to maintain a functional luminal progenitor compartment. This requires the repression of both YAP/TAZ and SRF/MRTF activities. TRPS1 represses SRF/MRTF activity indirectly by modulating RhoA activity. Our work uncovers a hitherto undisclosed function of TRPS1 in luminal progenitors intrinsically linked to mechanotransduction in the mammary gland. It may also provide new insights into the oncogenic functions of TRPS1 as luminal progenitors are likely the cells of origin of many breast cancers.
Wissenschaftlicher Artikel
Scientific Article
Tomar, A. ; Gómez Velázquez, M. ; Gerlini, R. ; Comas-Armangue, G. ; Makharadze, L. ; Kolbe, T. ; Boersma, A. ; Dahlhoff, M. ; Burgstaller, J.P. ; Lassi, M. ; Darr, J. ; Toppari, J. ; Virtanen, H. ; Kühnapfel, A. ; Scholz, M. ; Landgraf, K. ; Kiess, W. ; Vogel, M. ; Gailus-Durner, V. ; Fuchs, H. ; Marschall, S. ; Hrabě de Angelis, M. ; Kotaja, N. ; Körner, A. ; Teperino, R.
Nature, DOI: 10.1038/s41586-024-07472-3 (2024)
Spermatozoa harbour a complex and environment-sensitive pool of small non-coding RNAs (sncRNAs)1, which influences offspring development and adult phenotypes1-7. Whether spermatozoa in the epididymis are directly susceptible to environmental cues is not fully understood8. Here we used two distinct paradigms of preconception acute high-fat diet to dissect epididymal versus testicular contributions to the sperm sncRNA pool and offspring health. We show that epididymal spermatozoa, but not developing germ cells, are sensitive to the environment and identify mitochondrial tRNAs (mt-tRNAs) and their fragments (mt-tsRNAs) as sperm-borne factors. In humans, mt-tsRNAs in spermatozoa correlate with body mass index, and paternal overweight at conception doubles offspring obesity risk and compromises metabolic health. Sperm sncRNA sequencing of mice mutant for genes involved in mitochondrial function, and metabolic phenotyping of their wild-type offspring, suggest that the upregulation of mt-tsRNAs is downstream of mitochondrial dysfunction. Single-embryo transcriptomics of genetically hybrid two-cell embryos demonstrated sperm-to-oocyte transfer of mt-tRNAs at fertilization and suggested their involvement in the control of early-embryo transcription. Our study supports the importance of paternal health at conception for offspring metabolism, shows that mt-tRNAs are diet-induced and sperm-borne and demonstrates, in a physiological setting, father-to-offspring transfer of sperm mitochondrial RNAs at fertilization.
Wissenschaftlicher Artikel
Scientific Article
Wackerhage, H. ; Hinrichs, A. ; Wolf, E. ; Hrabě de Angelis, M.
J. Physiol.-London 602, 1655-1658 (2024)
Review
Review
2023
Ali Khan, A. ; Valera Vazquez, G. ; Gustems, M. ; Matteoni, R. ; Song, F. ; Gormanns, P. ; Fessele, S. ; Raess, M. ; Hrabě de Angelis, M.
Mamm. Genome 34, 408-417 (2023)
Over the last decade, INFRAFRONTIER has positioned itself as a world-class Research Infrastructure for the generation, phenotyping, archiving, and distribution of mouse models in Europe. The INFRAFRONTIER network consists of 22 partners from 15 countries, and is continuously enhancing and broadening its portfolio of resources and services that are offered to the research community on a non-profit basis. By bringing together European rodent model expertise and providing valuable disease model services to the biomedical research community, INFRAFRONTIER strives to push the accessibility of cutting-edge human disease modelling technologies across the European research landscape. This article highlights the latest INFRAFRONTIER developments and informs the research community about its extensively utilised services, resources, and technical developments, specifically the intricacies of the INFRAFRONTIER database, use of Curated Disease Models, overview of the INFRAFRONTIER Cancer and Rare Disease resources, and information about its main state-of-the-art services.
Review
Review
Bukas, C. ; Galter, I. ; da Silva Buttkus, P. ; Fuchs, H. ; Maier, H. ; Gailus-Durner, V. ; Müller, C.L. ; Hrabě de Angelis, M. ; Piraud, M. ; Spielmann, N.
Mamm. Genome 34, 200-215 (2023)
Echocardiography, a rapid and cost-effective imaging technique, assesses cardiac function and structure. Despite its popularity in cardiovascular medicine and clinical research, image-derived phenotypic measurements are manually performed, requiring expert knowledge and training. Notwithstanding great progress in deep-learning applications in small animal echocardiography, the focus has so far only been on images of anesthetized rodents. We present here a new algorithm specifically designed for echocardiograms acquired in conscious mice called Echo2Pheno, an automatic statistical learning workflow for analyzing and interpreting high-throughput non-anesthetized transthoracic murine echocardiographic images in the presence of genetic knockouts. Echo2Pheno comprises a neural network module for echocardiographic image analysis and phenotypic measurements, including a statistical hypothesis-testing framework for assessing phenotypic differences between populations. Using 2159 images of 16 different knockout mouse strains of the German Mouse Clinic, Echo2Pheno accurately confirms known cardiovascular genotype-phenotype relationships (e.g., Dystrophin) and discovers novel genes (e.g., CCR4-NOT transcription complex subunit 6-like, Cnot6l, and synaptotagmin-like protein 4, Sytl4), which cause altered cardiovascular phenotypes, as verified by H&E-stained histological images. Echo2Pheno provides an important step toward automatic end-to-end learning for linking echocardiographic readouts to cardiovascular phenotypes of interest in conscious mice.
Wissenschaftlicher Artikel
Scientific Article
Cacheiro, P. ; Spielmann, N. ; Mashhadi, H.H. ; Fuchs, H. ; Gailus-Durner, V. ; Smedley, D. ; Hrabě de Angelis, M.
Dis. Model. Mech. 16:dmm049770 (2023)
Mouse models are relevant to study the functionality of genes involved in human diseases, however, translation of phenotypes can be challenging. Herein, we investigated genes related to monogenic forms of cardiovascular disease based on the Genomics England PanelApp and aligned them to the International Mouse Phenotyping Consortium data. We found 153 genes associated to cardiomyopathy, cardiac arrhythmias or congenital heart disease in humans, 151 with a one2one mouse orthologs. For 37.7% (57/151) viability and heart data captured by electrocardiography, transthoracic echocardiography, morphology and pathology from embryos and young adult mice was available. In knockout mice, 75.4% (43/57) of these genes showed non-viable phenotypes, whereas records of prenatal, neonatal or infant death in humans were found for 35.1% (20/57). Multisystem phenotypes are common, with 58.8% (20/34) of heterozygous (homozygous lethal) and 78.6% (11/14) of homozygous (viable) mice showing cardiovascular, metabolic/homeostasis, musculoskeletal, hematopoietic, nervous system and/or growth abnormalities mimicking the clinical manifestations observed in patients. This IMPC data is critical beyond cardiac diagnostics given its multisystemic nature that allows detecting abnormalities across physiological systems, providing a valuable resource to understand pleiotropic effects.
Wissenschaftlicher Artikel
Scientific Article
Calame, D.G. ; Guo, T. ; Wang, C. ; Garrett, L. ; Jolly, A. ; Dawood, M. ; Kurolap, A. ; Henig, N.Z. ; Fatih, J.M. ; Herman, I. ; Du, H. ; Mitani, T. ; Becker, L. ; Rathkolb, B. ; Gerlini, R. ; Seisenberger, C. ; Marschall, S. ; Hunter, J.V. ; Gerard, A. ; Heidlebaugh, A. ; Challman, T. ; Spillmann, R.C. ; Jhangiani, S.N. ; Coban-Akdemir, Z. ; Lalani, S. ; Liu, L. ; Revah-Politi, A. ; Iglesias, A. ; Guzman, E. ; Baugh, E. ; Boddaert, N. ; Rondeau, S. ; Ormieres, C. ; Barcia, G. ; Tan, Q.K.G. ; Thiffault, I. ; Pastinen, T. ; Sheikh, K. ; Biliciler, S. ; Mei, D. ; Melani, F. ; Shashi, V. ; Yaron, Y. ; Steele, M. ; Wakeling, E. ; Østergaard, E. ; Nazaryan-Petersen, L. ; Millan, F. ; Santiago-Sim, T. ; Thevenon, J. ; Bruel, A.L. ; Thauvin-Robinet, C. ; Popp, D. ; Platzer, K. ; Gawlinski, P. ; Wiszniewski, W. ; Marafi, D. ; Pehlivan, D. ; Posey, J.E. ; Gibbs, R.A. ; Gailus-Durner, V. ; Guerrini, R. ; Fuchs, H. ; Hrabě de Angelis, M. ; Hölter, S.M. ; Cheung, H.H. ; Gu, S. ; Lupski, J.R.
Am. J. Hum. Genet. 110, 1394-1413 (2023)
DExD/H-box RNA helicases (DDX/DHX) are encoded by a large paralogous gene family; in a subset of these human helicase genes, pathogenic variation causes neurodevelopmental disorder (NDD) traits and cancer. DHX9 encodes a BRCA1-interacting nuclear helicase regulating transcription, R-loops, and homologous recombination and exhibits the highest mutational constraint of all DDX/DHX paralogs but remains unassociated with disease traits in OMIM. Using exome sequencing and family-based rare-variant analyses, we identified 20 individuals with de novo, ultra-rare, heterozygous missense or loss-of-function (LoF) DHX9 variant alleles. Phenotypes ranged from NDDs to the distal symmetric polyneuropathy axonal Charcot-Marie-Tooth disease (CMT2). Quantitative Human Phenotype Ontology (HPO) analysis demonstrated genotype-phenotype correlations with LoF variants causing mild NDD phenotypes and nuclear localization signal (NLS) missense variants causing severe NDD. We investigated DHX9 variant-associated cellular phenotypes in human cell lines. Whereas wild-type DHX9 was restricted to the nucleus, NLS missense variants abnormally accumulated in the cytoplasm. Fibroblasts from an individual with an NLS variant also showed abnormal cytoplasmic DHX9 accumulation. CMT2-associated missense variants caused aberrant nucleolar DHX9 accumulation, a phenomenon previously associated with cellular stress. Two NDD-associated variants, p.Gly411Glu and p.Arg761Gln, altered DHX9 ATPase activity. The severe NDD-associated variant p.Arg141Gln did not affect DHX9 localization but instead increased R-loop levels and double-stranded DNA breaks. Dhx9-/- mice exhibited hypoactivity in novel environments, tremor, and sensorineural hearing loss. All together, these results establish DHX9 as a critical regulator of mammalian neurodevelopment and neuronal homeostasis.
Wissenschaftlicher Artikel
Scientific Article
Chee, J.M. ; Lanoue, L. ; Clary, D. ; Higgins, K. ; Bower, L. ; Flenniken, A. ; Guo, R. ; Adams, D.J. ; Bosch, F. ; Braun, R.E. ; Brown, S.D.M. ; Chin, H.J.G. ; Dickinson, M.E. ; Hsu, C.W. ; Dobbie, M. ; Gao, X. ; Galande, S. ; Grobler, A. ; Heaney, J.D. ; Herault, Y. ; Hrabě de Angelis, M. ; Mammano, F. ; Nutter, L.M.J. ; Parkinson, H. ; Qin, C. ; Shiroishi, T. ; Sedlacek, R. ; Seong, J.K. ; Xu, Y. ; Ackert-Bicknell, C. ; Adams, D. ; Adoum, A.T. ; Akoma, U. ; Ali-Hadji, D. ; André, P. ; Auburtin, A. ; Bam’Hamed, C. ; Beig, J. ; Berberovic, Z. ; Bezginov, A. ; Birling, M.C. ; Boroviak, K. ; Bottomley, J. ; Butterfield, N.C. ; Cacheiro, P. ; Cambridge, E.L. ; Camilleri, S. ; Champy, M.F. ; Cater, H. ; Charles, P. ; Chesler, E.J. ; Christiansen, A.E. ; Cipriani, V. ; Cockle, N. ; Codner, G. ; Creighton, A. ; Cruz, M. ; Curry, K.F. ; D’Souza, A. ; Danisment, O. ; Delbarre, D. ; Dewhurst, H.F. ; Doe, B. ; Dorr, A. ; Duddy, G. ; Duffin, K. ; El Amri, A. ; Elrick, H. ; Eskandarian, M. ; Fray, M. ; Frost, A. ; Gampe, K.K. ; Ganguly, M. ; Gannon, D. ; Gertsenstein, M. ; Gleeson, D. ; Goodwin, L. ; Graw, J. ; Grimsrud, K. ; Haselimashhadi, H. ; Hobson, L. ; Hong, S.H. ; Horner, N. ; Trainor, A.G. ; Huang, Z. ; Kane, C. ; Katsman, Y.
BMC Biol. 21:22 (2023)
Background: Microphthalmia, anophthalmia, and coloboma (MAC) spectrum disease encompasses a group of eye malformations which play a role in childhood visual impairment. Although the predominant cause of eye malformations is known to be heritable in nature, with 80% of cases displaying loss-of-function mutations in the ocular developmental genes OTX2 or SOX2, the genetic abnormalities underlying the remaining cases of MAC are incompletely understood. This study intended to identify the novel genes and pathways required for early eye development. Additionally, pathways involved in eye formation during embryogenesis are also incompletely understood. This study aims to identify the novel genes and pathways required for early eye development through systematic forward screening of the mammalian genome. Results: Query of the International Mouse Phenotyping Consortium (IMPC) database (data release 17.0, August 01, 2022) identified 74 unique knockout lines (genes) with genetically associated eye defects in mouse embryos. The vast majority of eye abnormalities were small or absent eyes, findings most relevant to MAC spectrum disease in humans. A literature search showed that 27 of the 74 lines had previously published knockout mouse models, of which only 15 had ocular defects identified in the original publications. These 12 previously published gene knockouts with no reported ocular abnormalities and the 47 unpublished knockouts with ocular abnormalities identified by the IMPC represent 59 genes not previously associated with early eye development in mice. Of these 59, we identified 19 genes with a reported human eye phenotype. Overall, mining of the IMPC data yielded 40 previously unimplicated genes linked to mammalian eye development. Bioinformatic analysis showed that several of the IMPC genes colocalized to several protein anabolic and pluripotency pathways in early eye development. Of note, our analysis suggests that the serine-glycine pathway producing glycine, a mitochondrial one-carbon donator to folate one-carbon metabolism (FOCM), is essential for eye formation. Conclusions: Using genome-wide phenotype screening of single-gene knockout mouse lines, STRING analysis, and bioinformatic methods, this study identified genes heretofore unassociated with MAC phenotypes providing models to research novel molecular and cellular mechanisms involved in eye development. These findings have the potential to hasten the diagnosis and treatment of this congenital blinding disease.
Wissenschaftlicher Artikel
Scientific Article
da Silva Buttkus, P. ; Spielmann, N. ; Klein-Rodewald, T. ; Schütt, C. ; Aguilar-Pimentel, J.A. ; Amarie, O.V. ; Becker, L. ; Calzada-Wack, J. ; Garrett, L. ; Gerlini, R. ; Kraiger, M. ; Leuchtenberger, S. ; Östereicher, M.A. ; Rathkolb, B. ; Sanz-Moreno, A. ; Stoeger, C. ; Hölter, S.M. ; Seisenberger, C. ; Marschall, S. ; Fuchs, H. ; Gailus-Durner, V. ; Hrabě de Angelis, M.
Mamm. Genome 34, 244-261 (2023)
Rare diseases (RDs) are a challenge for medicine due to their heterogeneous clinical manifestations and low prevalence. There is a lack of specific treatments and only a few hundred of the approximately 7,000 RDs have an approved regime. Rapid technological development in genome sequencing enables the mass identification of potential candidates that in their mutated form could trigger diseases but are often not confirmed to be causal. Knockout (KO) mouse models are essential to understand the causality of genes by allowing highly standardized research into the pathogenesis of diseases. The German Mouse Clinic (GMC) is one of the pioneers in mouse research and successfully uses (preclinical) data obtained from single-gene KO mutants for research into monogenic RDs. As part of the International Mouse Phenotyping Consortium (IMPC) and INFRAFRONTIER, the pan-European consortium for modeling human diseases, the GMC expands these preclinical data toward global collaborative approaches with researchers, clinicians, and patient groups.Here, we highlight proprietary genes that when deleted mimic clinical phenotypes associated with known RD targets (Nacc1, Bach2, Klotho alpha). We focus on recognized RD genes with no pre-existing KO mouse models (Kansl1l, Acsf3, Pcdhgb2, Rabgap1, Cox7a2) which highlight novel phenotypes capable of optimizing clinical diagnosis. In addition, we present genes with intriguing phenotypic data (Zdhhc5, Wsb2) that are not presently associated with known human RDs.This report provides comprehensive evidence for genes that when deleted cause differences in the KO mouse across multiple organs, providing a huge translational potential for further understanding monogenic RDs and their clinical spectrum. Genetic KO studies in mice are valuable to further explore the underlying physiological mechanisms and their overall therapeutic potential.
Wissenschaftlicher Artikel
Scientific Article
Dreher, S.I. ; Irmler, M. ; Pivovarova-Ramich, O. ; Kessler, K. ; Jurchott, K. ; Sticht, C. ; Fritsche, L. ; Schneeweiss, P. ; Machann, J. ; Pfeiffer, A.F.H. ; Hrabě de Angelis, M. ; Beckers, J. ; Birkenfeld, A.L. ; Peter, A. ; Niess, A.M. ; Weigert, C. ; Moller, A.
Int. J. Obes. 47, 313-324 (2023)
Background: Exercise exerts many health benefits by directly inducing molecular alterations in physically utilized skeletal muscle. Molecular adaptations of subcutaneous adipose tissue (SCAT) might also contribute to the prevention of metabolic diseases. Aim: To characterize the response of human SCAT based on changes in transcripts and mitochondrial respiration to acute and repeated bouts of exercise in comparison to skeletal muscle. Methods: Sedentary participants (27 ± 4 yrs) with overweight or obesity underwent 8-week supervised endurance exercise 3×1h/week at 80% VO2peak. Before, 60 min after the first and last exercise bout and 5 days post intervention, biopsies were taken for transcriptomic analyses and high-resolution respirometry (n = 14, 8 female/6 male). Results: In SCAT, we found 37 acutely regulated transcripts (FC > 1.2, FDR < 10%) after the first exercise bout compared to 394, respectively, in skeletal muscle. Regulation of only 5 transcripts overlapped between tissues highlighting their differential response. Upstream and enrichment analyses revealed reduced transcripts of lipid uptake, storage and lipogenesis directly after exercise in SCAT and point to β-adrenergic regulation as potential major driver. The data also suggest an exercise-induced modulation of the circadian clock in SCAT. Neither term was associated with transcriptomic changes in skeletal muscle. No evidence for beigeing/browning was found in SCAT along with unchanged respiration. Conclusions: Adipose tissue responds completely distinct from adaptations of skeletal muscle to exercise. The acute and repeated reduction in transcripts of lipid storage and lipogenesis, interconnected with a modulated circadian rhythm, can counteract metabolic syndrome progression toward diabetes.
Wissenschaftlicher Artikel
Scientific Article