Publications by authors named "Wolfgang Hans"

51 Publications

A comprehensive and comparative phenotypic analysis of the collaborative founder strains identifies new and known phenotypes.

Mamm Genome 2020 02 14;31(1-2):30-48. Epub 2020 Feb 14.

Department of Neurology, Friedrich-Baur-Institute, Klinikum Der Ludwig-Maximilians-Universität München, Ziemssenstr. 1a, 80336, Munich, Germany.

The collaborative cross (CC) is a large panel of mouse-inbred lines derived from eight founder strains (NOD/ShiLtJ, NZO/HILtJ, A/J, C57BL/6J, 129S1/SvImJ, CAST/EiJ, PWK/PhJ, and WSB/EiJ). Here, we performed a comprehensive and comparative phenotyping screening to identify phenotypic differences and similarities between the eight founder strains. In total, more than 300 parameters including allergy, behavior, cardiovascular, clinical blood chemistry, dysmorphology, bone and cartilage, energy metabolism, eye and vision, immunology, lung function, neurology, nociception, and pathology were analyzed; in most traits from sixteen females and sixteen males. We identified over 270 parameters that were significantly different between strains. This study highlights the value of the founder and CC strains for phenotype-genotype associations of many genetic traits that are highly relevant to human diseases. All data described here are publicly available from the mouse phenome database for analyses and downloads.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00335-020-09827-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7060152PMC
February 2020

A mouse model for intellectual disability caused by mutations in the X-linked 2'‑O‑methyltransferase Ftsj1 gene.

Biochim Biophys Acta Mol Basis Dis 2019 09 14;1865(9):2083-2093. Epub 2018 Dec 14.

Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University München, Feodor-Lynen Str. 25, 81377 München, Germany.

Mutations in the X chromosomal tRNA 2'‑O‑methyltransferase FTSJ1 cause intellectual disability (ID). Although the gene is ubiquitously expressed affected individuals present no consistent clinical features beyond ID. In order to study the pathological mechanism involved in the aetiology of FTSJ1 deficiency-related cognitive impairment, we generated and characterized an Ftsj1 deficient mouse line based on the gene trapped stem cell line RRD143. Apart from an impaired learning capacity these mice presented with several statistically significantly altered features related to behaviour, pain sensing, bone and energy metabolism, the immune and the hormone system as well as gene expression. These findings show that Ftsj1 deficiency in mammals is not phenotypically restricted to the brain but affects various organ systems. Re-examination of ID patients with FTSJ1 mutations from two previously reported families showed that several features observed in the mouse model were recapitulated in some of the patients. Though the clinical spectrum related to Ftsj1 deficiency in mouse and man is variable, we suggest that an increased pain threshold may be more common in patients with FTSJ1 deficiency. Our findings demonstrate novel roles for Ftsj1 in maintaining proper cellular and tissue functions in a mammalian organism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbadis.2018.12.011DOI Listing
September 2019

The heterozygous R155C VCP mutation: Toxic in humans! Harmless in mice?

Biochem Biophys Res Commun 2018 09 9;503(4):2770-2777. Epub 2018 Aug 9.

Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, 91054, Erlangen, Germany. Electronic address:

Heterozygous missense mutations in the human VCP gene cause inclusion body myopathy associated with Paget disease of bone and fronto-temporal dementia (IBMPFD) and amyotrophic lateral sclerosis (ALS). The exact molecular mechanisms by which VCP mutations cause disease manifestation in different tissues are incompletely understood. In the present study, we report the comprehensive analysis of a newly generated R155C VCP knock-in mouse model, which expresses the ortholog of the second most frequently occurring human pathogenic VCP mutation. Heterozygous R155C VCP knock-in mice showed decreased plasma lactate, serum albumin and total protein concentrations, platelet numbers, and liver to body weight ratios, and increased oxygen consumption and CD8+/Ly6C + T-cell fractions, but none of the typical human IBMPFD or ALS pathologies. Breeding of heterozygous mice did not yield in the generation of homozygous R155C VCP knock-in animals. Immunoblotting showed identical total VCP protein levels in human IBMPFD and murine R155C VCP knock-in tissues as compared to wild-type controls. However, while in human IBMPFD skeletal muscle tissue 70% of the total VCP mRNA was derived from the mutant allele, in R155C VCP knock-in mice only 5% and 7% mutant mRNA were detected in skeletal muscle and brain tissue, respectively. The lack of any obvious IBMPFD or ALS pathology could thus be a consequence of the very low expression of mutant VCP. We conclude that the increased and decreased fractions of the R155C mutant VCP mRNA in man and mice, respectively, are due to missense mutation-induced, divergent alterations in the biological half-life of the human and murine mutant mRNAs. Furthermore, our work suggests that therapy approaches lowering the expression of the mutant VCP mRNA below a critical threshold may ameliorate the intrinsic disease pathology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbrc.2018.08.038DOI Listing
September 2018

Laboratory mouse housing conditions can be improved using common environmental enrichment without compromising data.

PLoS Biol 2018 04 16;16(4):e2005019. Epub 2018 Apr 16.

German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.

Animal welfare requires the adequate housing of animals to ensure health and well-being. The application of environmental enrichment is a way to improve the well-being of laboratory animals. However, it is important to know whether these enrichment items can be incorporated in experimental mouse husbandry without creating a divide between past and future experimental results. Previous small-scale studies have been inconsistent throughout the literature, and it is not yet completely understood whether and how enrichment might endanger comparability of results of scientific experiments. Here, we measured the effect on means and variability of 164 physiological parameters in 3 conditions: with nesting material with or without a shelter, comparing these 2 conditions to a "barren" regime without any enrichments. We studied a total of 360 mice from each of 2 mouse strains (C57BL/6NTac and DBA/2NCrl) and both sexes for each of the 3 conditions. Our study indicates that enrichment affects the mean values of some of the 164 parameters with no consistent effects on variability. However, the influence of enrichment appears negligible compared to the effects of other influencing factors. Therefore, nesting material and shelters may be used to improve animal welfare without impairment of experimental outcome or loss of comparability to previous data collected under barren housing conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pbio.2005019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5922977PMC
April 2018

Genetic and Molecular Insights Into Genotype-Phenotype Relationships in Osteopathia Striata With Cranial Sclerosis (OSCS) Through the Analysis of Novel Mouse Wtx Mutant Alleles.

J Bone Miner Res 2018 05 1;33(5):875-887. Epub 2018 Mar 1.

Université Côte d'Azur, INSERM, CNRS, Institut de Biologie Valrose (iBV), Nice, France.

The X-linked WTX/AMER1 protein constitutes an important component of the β-catenin destruction complex that can both enhance and suppress canonical β-catenin signaling. Somatic mutations in WTX/AMER1 have been found in a proportion of the pediatric kidney cancer Wilms' tumor. By contrast, germline mutations cause the severe sclerosing bone dysplasia osteopathia striata congenita with cranial sclerosis (OSCS), a condition usually associated with fetal or perinatal lethality in male patients. Here we address the developmental and molecular function of WTX by generating two novel mouse alleles. We show that in addition to the previously reported skeletal abnormalities, loss of Wtx causes severe midline fusion defects including cleft palate and ectopic synostosis at the base of the skull. By contrast, deletion of the C-terminal part of the protein results in only mild developmental abnormalities permitting survival beyond birth. Adult analysis, however, revealed skeletal defects including changed skull morphology and an increased whole-body bone density, resembling a subgroup of male patients carrying a milder, survivable phenotype. Molecular analysis in vitro showed that while β-catenin fails to co-immunoprecipitate with the truncated protein, partial recruitment appears to be achieved in an indirect manner using AXIN/AXIN2 as a molecular bridge. Taken together our analysis provides a novel model for WTX-caused bone diseases and explains on the molecular level how truncation mutations in this gene may retain some of WTX-protein functions. © 2018 American Society for Bone and Mineral Research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jbmr.3387DOI Listing
May 2018

Fgf9 Mutation Alters Information Processing and Social Memory in Mice.

Mol Neurobiol 2018 Jun 10;55(6):4580-4595. Epub 2017 Jul 10.

Institutes of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany.

In neuropsychiatric diseases, such as major depression and anxiety, pathogenic vulnerability is partially dictated by a genetic predisposition. The search continues to define this genetic susceptibility and establish new genetic elements as potential therapeutic targets. The fibroblast growth factors (FGFs) could be interesting in this regard. This family of signaling molecules plays important roles in development while also functioning within the adult. This includes effects on aspects of brain function such as neurogenesis and synapse formation. Of this family, Fgf9 is expressed in the adult brain, but its functional role is less well defined. In this study, we examined the role of Fgf9 in different brain functions by analyzing the behavior of Fgf9 mutant mice, an Fgf9 allele without the confounding systemic effects of other Fgf9 genetic models. Here, we show that this mutation caused altered locomotor and exploratory reactivity to novel, mildly stressful environments. In addition, mutants showed heightened acoustic startle reactivity as well as impaired social discrimination memory. Notably, there was a substantial decrease in the level of adult olfactory bulb neurogenesis with no difference in hippocampal neurogenesis. Collectively, our findings indicate a role for the Fgf9 mutation in information processing and perception of aversive situations as well as in social memory. Thus, genetic alterations in Fgf9 could increase vulnerability to developing neuropsychiatric disease, and we propose the Fgf9 mutant mice as a valuable tool to study the predictive etiological aspects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12035-017-0659-3DOI Listing
June 2018

The First Scube3 Mutant Mouse Line with Pleiotropic Phenotypic Alterations.

G3 (Bethesda) 2016 12 7;6(12):4035-4046. Epub 2016 Dec 7.

German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany.

The vertebrate Scube (Signal peptide, CUB, and EGF-like domain-containing protein) family consists of three independent members, Scube1-3, which encode secreted cell surface-associated membrane glycoproteins. Limited information about the general function of this gene family is available, and their roles during adulthood. Here, we present the first Scube3 mutant mouse line (Scube3), which clearly shows phenotypic alterations by carrying a missense mutation in exon 8, and thus contributes to our understanding of SCUBE3 functions. We performed a detailed phenotypic characterization in the German Mouse Clinic (GMC). Scube3 mutants showed morphological abnormalities of the skeleton, alterations of parameters relevant for bone metabolism, changes in renal function, and hearing impairments. These findings correlate with characteristics of the rare metabolic bone disorder Paget disease of bone (PDB), associated with the chromosomal region of human SCUBE3 In addition, alterations in energy metabolism, behavior, and neurological functions were detected in Scube3 mice. The Scube3 mutant mouse line may serve as a new model for further studying the effect of impaired SCUBE3 gene function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1534/g3.116.033670DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5144972PMC
December 2016

Viable Ednra mice feature human mandibulofacial dysostosis with alopecia (MFDA) syndrome due to the homologue mutation.

Mamm Genome 2016 12 26;27(11-12):587-598. Epub 2016 Sep 26.

Institute of Experimental Genetics and German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstr.1, 85764, Neuherberg, Germany.

Animal models resembling human mutations are valuable tools to research the features of complex human craniofacial syndromes. This is the first report on a viable dominant mouse model carrying a non-synonymous sequence variation within the endothelin receptor type A gene (Ednra c.386A>T, p.Tyr129Phe) derived by an ENU mutagenesis program. The identical amino acid substitution was reported recently as disease causing in three individuals with the mandibulofacial dysostosis with alopecia (MFDA, OMIM 616367) syndrome. We performed standardized phenotyping of wild-type, heterozygous, and homozygous Ednra mice within the German Mouse Clinic. Mutant mice mimic the craniofacial phenotypes of jaw dysplasia, micrognathia, dysplastic temporomandibular joints, auricular dysmorphism, and missing of the squamosal zygomatic process as described for MFDA-affected individuals. As observed in MFDA-affected individuals, mutant Ednra mice exhibit hearing impairment in line with strong abnormalities of the ossicles and further, reduction of some lung volumetric parameters. In general, heterozygous and homozygous mice demonstrated inter-individual diversity of expression of the craniofacial phenotypes as observed in MFDA patients but without showing any cleft palates, eyelid defects, or alopecia. Mutant Ednra mice represent a valuable viable model for complex human syndromes of the first and second pharyngeal arches and for further studies and analysis of impaired endothelin 1 (EDN1)-endothelin receptor type A (EDNRA) signaling. Above all, Ednra mice model the recently published human MFDA syndrome and may be helpful for further disease understanding and development of therapeutic interventions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00335-016-9664-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5110705PMC
December 2016

Hyperoxaluria Requires TNF Receptors to Initiate Crystal Adhesion and Kidney Stone Disease.

J Am Soc Nephrol 2017 Mar 9;28(3):761-768. Epub 2016 Sep 9.

Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany;

Intrarenal crystals trigger inflammation and renal cell necroptosis, processes that involve TNF receptor (TNFR) signaling. Here, we tested the hypothesis that TNFRs also have a direct role in tubular crystal deposition and progression of hyperoxaluria-related CKD. Immunohistochemical analysis revealed upregulated tubular expression of TNFR1 and TNFR2 in human and murine kidneys with calcium oxalate (CaOx) nephrocalcinosis-related CKD compared with controls. Western blot and mRNA expression analyses in mice yielded consistent data. When fed an oxalate-rich diet, wild-type mice developed progressive CKD, whereas , and deficient mice did not. Despite identical levels of hyperoxaluria, , and -deficient mice also lacked the intrarenal CaOx deposition and tubular damage observed in wild-type mice. Inhibition of TNFR signaling prevented the induced expression of the crystal adhesion molecules, CD44 and annexin II, in tubular epithelial cells and , and treatment with the small molecule TNFR inhibitor R-7050 partially protected hyperoxaluric mice from nephrocalcinosis and CKD. We conclude that TNFR signaling is essential for CaOx crystal adhesion to the luminal membrane of renal tubules as a fundamental initiating mechanism of oxalate nephropathy. Furthermore, therapeutic blockade of TNFR might delay progressive forms of nephrocalcinosis in oxalate nephropathy, such as primary hyperoxaluria.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1681/ASN.2016040486DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5328164PMC
March 2017

Generation and Standardized, Systemic Phenotypic Analysis of Pou3f3L423P Mutant Mice.

PLoS One 2016 22;11(3):e0150472. Epub 2016 Mar 22.

Chair for Molecular Animal Breeding and Biotechnology, and Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, 81377, Munich, Germany.

Increased levels of blood plasma urea were used as phenotypic parameter for establishing novel mouse models for kidney diseases on the genetic background of C3H inbred mice in the phenotype-driven Munich ENU mouse mutagenesis project. The phenotypically recessive mutant line HST011 was established and further analyzed. The causative mutation was detected in the POU domain, class 3 transcription factor 3 (Pou3f3) gene, which leads to the amino acid exchange Pou3f3L423P thereby affecting the conserved homeobox domain of the protein. Pou3f3 homozygous knockout mice are published and show perinatal death. Line Pou3f3L423P is a viable mouse model harboring a homozygous Pou3f3 mutation. Standardized, systemic phenotypic analysis of homozygous mutants was carried out in the German Mouse Clinic. Main phenotypic changes were low body weight and a state of low energy stores, kidney dysfunction and secondary effects thereof including low bone mineralization, multiple behavioral and neurological defects including locomotor, vestibular, auditory and nociceptive impairments, as well as multiple subtle changes in immunological parameters. Genome-wide transcriptome profiling analysis of kidney and brain of Pou3f3L423P homozygous mutants identified significantly regulated genes as compared to wild-type controls.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0150472PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4803225PMC
August 2016

Exome sequencing identifies a nonsense mutation in Fam46a associated with bone abnormalities in a new mouse model for skeletal dysplasia.

Mamm Genome 2016 Apr 23;27(3-4):111-21. Epub 2016 Jan 23.

Institute of Human Genetics, German Research Center for Environmental Health (GmbH), Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.

We performed exome sequencing for mutation discovery of an ENU (N-ethyl-N-nitrosourea)-derived mouse model characterized by significant elevated plasma alkaline phosphatase (ALP) activities in female and male mutant mice, originally named BAP014 (bone screen alkaline phosphatase #14). We identified a novel loss-of-function mutation within the Fam46a (family with sequence similarity 46, member A) gene (NM_001160378.1:c.469G>T, NP_001153850.1:p.Glu157*). Heterozygous mice of this mouse line (renamed Fam46a (E157*Mhda)) had significantly high ALP activities and apparently no other differences in morphology compared to wild-type mice. In contrast, homozygous Fam46a (E157*Mhda) mice showed severe morphological and skeletal abnormalities including short stature along with limb, rib, pelvis, and skull deformities with minimal trabecular bone and reduced cortical bone thickness in long bones. ALP activities of homozygous mutants were almost two-fold higher than in heterozygous mice. Fam46a is weakly expressed in most adult and embryonic tissues with a strong expression in mineralized tissues as calvaria and femur. The FAM46A protein is computationally predicted as a new member of the superfamily of nucleotidyltransferase fold proteins, but little is known about its function. Fam46a (E157*Mhda) mice are the first mouse model for a mutation within the Fam46a gene.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00335-016-9619-xDOI Listing
April 2016

Analysis of mammalian gene function through broad-based phenotypic screens across a consortium of mouse clinics.

Nat Genet 2015 Sep 27;47(9):969-978. Epub 2015 Jul 27.

Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany.

The function of the majority of genes in the mouse and human genomes remains unknown. The mouse embryonic stem cell knockout resource provides a basis for the characterization of relationships between genes and phenotypes. The EUMODIC consortium developed and validated robust methodologies for the broad-based phenotyping of knockouts through a pipeline comprising 20 disease-oriented platforms. We developed new statistical methods for pipeline design and data analysis aimed at detecting reproducible phenotypes with high power. We acquired phenotype data from 449 mutant alleles, representing 320 unique genes, of which half had no previous functional annotation. We captured data from over 27,000 mice, finding that 83% of the mutant lines are phenodeviant, with 65% demonstrating pleiotropy. Surprisingly, we found significant differences in phenotype annotation according to zygosity. New phenotypes were uncovered for many genes with previously unknown function, providing a powerful basis for hypothesis generation and further investigation in diverse systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ng.3360DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4564951PMC
September 2015

MIM-Induced Membrane Bending Promotes Dendritic Spine Initiation.

Dev Cell 2015 Jun 4;33(6):644-59. Epub 2015 Jun 4.

Neuroscience Center, P.O. Box 56, University of Helsinki, 00014 Helsinki, Finland. Electronic address:

Proper morphogenesis of neuronal dendritic spines is essential for the formation of functional synaptic networks. However, it is not known how spines are initiated. Here, we identify the inverse-BAR (I-BAR) protein MIM/MTSS1 as a nucleator of dendritic spines. MIM accumulated to future spine initiation sites in a PIP2-dependent manner and deformed the plasma membrane outward into a proto-protrusion via its I-BAR domain. Unexpectedly, the initial protrusion formation did not involve actin polymerization. However, PIP2-dependent activation of Arp2/3-mediated actin assembly was required for protrusion elongation. Overexpression of MIM increased the density of dendritic protrusions and suppressed spine maturation. In contrast, MIM deficiency led to decreased density of dendritic protrusions and larger spine heads. Moreover, MIM-deficient mice displayed altered glutamatergic synaptic transmission and compatible behavioral defects. Collectively, our data identify an important morphogenetic pathway, which initiates spine protrusions by coupling phosphoinositide signaling, direct membrane bending, and actin assembly to ensure proper synaptogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.devcel.2015.04.014DOI Listing
June 2015

Screen for alterations of iron related parameters in N-ethyl-N-nitrosourea-treated mice identified mutant lines with increased plasma ferritin levels.

Biometals 2015 Apr 31;28(2):293-306. Epub 2015 Jan 31.

Chair for Molecular Animal Breeding and Biotechnology, Department of Veterinary Sciences, and Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU Munich, Feodor-Lynen-Str. 25, 81377, Munich, Germany,

Iron is essential for numerous cellular processes. For diagnostic purposes iron-related parameters in patients are assessed by clinical chemical blood analysis including the analysis of ferritin, transferrin and iron levels. Here, we retrospectively evaluated the use of these parameters in the phenotype-driven Munich N-ethyl-N-nitrosourea mouse mutagenesis project for the generation of novel animal models for human diseases. The clinical chemical blood analysis was carried out on more than 10,700 G1 and G3 offspring of chemically mutagenized inbred C3H mice to detect dominant and recessive mutations leading to deviations in the plasma levels of iron-related plasma parameters. We identified animals consistently exhibiting altered plasma ferritin or transferrin values. Transmission of the phenotypic deviations to the subsequent generations led to the successful establishment of three mutant lines with increased plasma ferritin levels. For two of these lines the causative mutations were identified in the Fth1gene and the Ireb2 gene, respectively. Thus, novel mouse models for the functional analysis of iron homeostasis were established by a phenotype-driven screen for mutant mice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10534-015-9824-1DOI Listing
April 2015

Loss of Npn1 from motor neurons causes postnatal deficits independent from Sema3A signaling.

Dev Biol 2015 Mar 13;399(1):2-14. Epub 2014 Dec 13.

Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany. Electronic address:

The correct wiring of neuronal circuits is of crucial importance for the function of the vertebrate nervous system. Guidance cues like the neuropilin receptors (Npn) and their ligands, the semaphorins (Sema) provide a tight spatiotemporal control of sensory and motor axon growth and guidance. Among this family of guidance partners the Sema3A-Npn1 interaction has been shown to be of great importance, since defective signaling leads to wiring deficits and defasciculation. For the embryonic stage these defects have been well described, however, also after birth the organism can adapt to new challenges by compensational mechanisms. Therefore, we used the mouse lines Olig2-Cre;Npn1(cond) and Npn1(Sema-) to investigate how postnatal organisms cope with the loss of Npn1 selectively from motor neurons or a systemic dysfunctional Sema3A-Npn1 signaling in the entire organism, respectively. While in Olig2-Cre(+);Npn1(cond-/-) mice clear anatomical deficits in paw posturing, bone structure, as well as muscle and nerve composition became evident, Npn1(Sema-) mutants appeared anatomically normal. Furthermore, Olig2-Cre(+);Npn1(cond) mutants revealed a dysfunctional extensor muscle innervation after single-train stimulation of the N.radial. Interestingly, these mice did not show obvious deficits in voluntary locomotion, however, skilled motor function was affected. In contrast, Npn1(Sema-) mutants were less affected in all behavioral tests and able to improve their performance over time. Our data suggest that loss of Sema3A-Npn1 signaling is not the only cause for the observed deficits in Olig2-Cre(+);Npn1(cond-/-) mice and that additional, yet unknown binding partners for Npn1 may be involved that allow Npn1(Sema-) mutants to compensate for their developmental deficits.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ydbio.2014.11.024DOI Listing
March 2015

Pleiotropic functions for transcription factor zscan10.

PLoS One 2014 11;9(8):e104568. Epub 2014 Aug 11.

German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; Chair for Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany.

The transcription factor Zscan10 had been attributed a role as a pluripotency factor in embryonic stem cells based on its interaction with Oct4 and Sox2 in in vitro assays. Here we suggest a potential role of Zscan10 in controlling progenitor cell populations in vivo. Mice homozygous for a Zscan10 mutation exhibit reduced weight, mild hypoplasia in the spleen, heart and long bones and phenocopy an eye malformation previously described for Sox2 hypomorphs. Phenotypic abnormalities are supported by the nature of Zscan10 expression in midgestation embryos and adults suggesting a role for Zscan10 in either maintaining progenitor cell subpopulation or impacting on fate choice decisions thereof.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0104568PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4128777PMC
April 2015

Standardized, systemic phenotypic analysis of Slc12a1I299F mutant mice.

J Biomed Sci 2014 Aug 2;21:68. Epub 2014 Aug 2.

Background: Type I Bartter syndrome is a recessive human nephropathy caused by loss-of-function mutations in the SLC12A1 gene coding for the Na+-K+-2Cl- cotransporter NKCC2. We recently established the mutant mouse line Slc12a1I299F exhibiting kidney defects highly similar to the late-onset manifestation of this hereditary human disease. Besides the kidney defects, low blood pressure and osteopenia were revealed in the homozygous mutant mice which were also described in humans. Beside its strong expression in the kidney, NKCC2 has been also shown to be expressed in other tissues in rodents i.e. the gastrointestinal tract, pancreatic beta cells, and specific compartments of the ear, nasal tissue and eye.

Results: To examine if, besides kidney defects, further organ systems and/or metabolic pathways are affected by the Slc12a1I299F mutation as primary or secondary effects, we describe a standardized, systemic phenotypic analysis of the mutant mouse line Slc12a1I299F in the German Mouse Clinic. Slc12a1I299F homozygous mutant mice and Slc12a1I299F heterozygous mutant littermates as controls were tested at the age of 4-6 months. Beside the already published changes in blood pressure and bone metabolism, a significantly lower body weight and fat content were found as new phenotypes for Slc12a1I299F homozygous mutant mice. Small additional effects included a mild erythropenic anemia in homozygous mutant males as well as a slight hyperalgesia in homozygous mutant females. For other functions, such as immunology, lung function and neurology, no distinct alterations were observed.

Conclusions: In this systemic analysis no clear primary effects of the Slc12a1I299F mutation appeared for the organs other than the kidneys where Slc12a1 expression has been described. On the other hand, long-term effects additional and/or secondary to the kidney lesions might also appear in humans harboring SLC12A1 mutations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12929-014-0068-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4237776PMC
August 2014

Mitochondrial dysfunction and decrease in body weight of a transgenic knock-in mouse model for TDP-43.

J Biol Chem 2014 Apr 10;289(15):10769-10784. Epub 2014 Feb 10.

Helmholtz Zentrum München, Institute of Developmental Genetics, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany; Technische Universität München, c/o Helmholtz Zentrum München, 85764 Neuherberg, Germany. Electronic address:

The majority of amyotrophic lateral sclerosis (ALS) cases as well as many patients suffering from frontotemporal lobar dementia (FTLD) with ubiquitinated inclusion bodies show TDP-43 pathology, the protein encoded by the TAR DNA-binding protein (Tardbp) gene. We used recombinase-mediated cassette exchange to introduce an ALS patient cDNA into the mouse Tdp-43 locus. Expression levels of human A315T TDP-43 protein were 300% elevated in heterozygotes, whereas the endogenous mouse Tdp-43 was decreased to 20% of wild type levels as a result of disturbed feedback regulation. Heterozygous TDP-43(A315TKi) mutants lost 10% of their body weight and developed insoluble TDP-43 protein starting as early as 3 months after birth, a pathology that was exacerbated with age. We analyzed the splicing patterns of known Tdp-43 target genes as well as genome-wide gene expression levels in different tissues that indicated mitochondrial dysfunction. In heterozygous mutant animals, we observed a relative decrease in expression of Parkin (Park2) and the fatty acid transporter CD36 along with an increase in fatty acids, HDL cholesterol, and glucose in the blood. As seen in transmission electron microscopy, neuronal cells in motor cortices of TDP-43(A315TKi) animals had abnormal neuronal mitochondrial cristae formation. Motor neurons were reduced to 90%, but only slight motoric impairment was detected. The observed phenotype was interpreted as a predisease model, which might be valuable for the identification of further environmental or genetic triggers of neurodegeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.M113.515940DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4036193PMC
April 2014

A broad phenotypic screen identifies novel phenotypes driven by a single mutant allele in Huntington's disease CAG knock-in mice.

PLoS One 2013 22;8(11):e80923. Epub 2013 Nov 22.

German Mouse Clinic, Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg/Munich, Germany.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucleotide repeat in the HTT gene encoding huntingtin. The disease has an insidious course, typically progressing over 10-15 years until death. Currently there is no effective disease-modifying therapy. To better understand the HD pathogenic process we have developed genetic HTT CAG knock-in mouse models that accurately recapitulate the HD mutation in man. Here, we describe results of a broad, standardized phenotypic screen in 10-46 week old heterozygous HdhQ111 knock-in mice, probing a wide range of physiological systems. The results of this screen revealed a number of behavioral abnormalities in HdhQ111/+ mice that include hypoactivity, decreased anxiety, motor learning and coordination deficits, and impaired olfactory discrimination. The screen also provided evidence supporting subtle cardiovascular, lung, and plasma metabolite alterations. Importantly, our results reveal that a single mutant HTT allele in the mouse is sufficient to elicit multiple phenotypic abnormalities, consistent with a dominant disease process in patients. These data provide a starting point for further investigation of several organ systems in HD, for the dissection of underlying pathogenic mechanisms and for the identification of reliable phenotypic endpoints for therapeutic testing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0080923PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3838378PMC
December 2014

Standardized, systemic phenotypic analysis of Umod(C93F) and Umod(A227T) mutant mice.

PLoS One 2013 24;8(10):e78337. Epub 2013 Oct 24.

Chair for Molecular Animal Breeding and Biotechnology, and Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU, Munich, Munich, Germany.

Uromodulin-associated kidney disease (UAKD) summarizes different clinical features of an autosomal dominant heritable disease syndrome in humans with a proven uromodulin (UMOD) mutation involved. It is often characterized by hyperuricemia, gout, alteration of urine concentrating ability, as well as a variable rate of disease progression inconstantly leading to renal failure and histological alterations of the kidneys. We recently established the two Umod mutant mouse lines Umod(C93F) and Umod(A227T) on the C3H inbred genetic background both showing kidney defects analogous to those found in human UAKD patients. In addition, disease symptoms were revealed that were not yet described in other published mouse models of UAKD. To examine if further organ systems and/or metabolic pathways are affected by Umod mutations as primary or secondary effects, we describe a standardized, systemic phenotypic analysis of the two mutant mouse lines Umod(A227T) and Umod(C93F) in the German Mouse Clinic. Different genotypes as well as different ages were tested. Beside the already published changes in body weight, body composition and bone metabolism, the influence of the Umod mutation on energy metabolism was confirmed. Hematological analysis revealed a moderate microcytic and erythropenic anemia in older Umod mutant mice. Data of the other analyses in 7-10 month-old mutant mice showed single small additional effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0078337PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3813435PMC
February 2015

Long-term experiment to study the development, interaction, and influencing factors of DEXA parameters.

Mamm Genome 2013 Oct 6;24(9-10):376-88. Epub 2013 Oct 6.

Helmholtz Zentrum München, German Mouse Clinic, Institute of Experimental Genetics, German Research Center for Environmental Health (GmbH), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany,

Dual-energy X-ray absorption (DEXA) is commonly used to measure bone mineral density (BMD), bone mineral content (BMC), and body composition data (fat mass and lean mass) for phenotype assessment in mice. We were interested in the long-term development of BMD, BMC, lean mass, and fat mass of mice, also taking into account sex and genetic background. The dataset was used to analyze correlations among the different parameters. We analyzed males and females from inbred strains C3HeB/FeJ and C57BL/6J, starting from 42 until 528 days of age. To evaluate the effect of husbandry systems, we repeated a part of the study in a second facility with a different caging system. We also assessed different DEXA settings and repeatability of the scans. The results of this study were used to draw conclusions for the use of DEXA analysis in mouse phenotyping approaches.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00335-013-9477-8DOI Listing
October 2013

A comparative phenotypic and genomic analysis of C57BL/6J and C57BL/6N mouse strains.

Genome Biol 2013 Jul 31;14(7):R82. Epub 2013 Jul 31.

Background: The mouse inbred line C57BL/6J is widely used in mouse genetics and its genome has been incorporated into many genetic reference populations. More recently large initiatives such as the International Knockout Mouse Consortium (IKMC) are using the C57BL/6N mouse strain to generate null alleles for all mouse genes. Hence both strains are now widely used in mouse genetics studies. Here we perform a comprehensive genomic and phenotypic analysis of the two strains to identify differences that may influence their underlying genetic mechanisms.

Results: We undertake genome sequence comparisons of C57BL/6J and C57BL/6N to identify SNPs, indels and structural variants, with a focus on identifying all coding variants. We annotate 34 SNPs and 2 indels that distinguish C57BL/6J and C57BL/6N coding sequences, as well as 15 structural variants that overlap a gene. In parallel we assess the comparative phenotypes of the two inbred lines utilizing the EMPReSSslim phenotyping pipeline, a broad based assessment encompassing diverse biological systems. We perform additional secondary phenotyping assessments to explore other phenotype domains and to elaborate phenotype differences identified in the primary assessment. We uncover significant phenotypic differences between the two lines, replicated across multiple centers, in a number of physiological, biochemical and behavioral systems.

Conclusions: Comparison of C57BL/6J and C57BL/6N demonstrates a range of phenotypic differences that have the potential to impact upon penetrance and expressivity of mutational effects in these strains. Moreover, the sequence variants we identify provide a set of candidate genes for the phenotypic differences observed between the two strains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/gb-2013-14-7-r82DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4053787PMC
July 2013

Rapamycin extends murine lifespan but has limited effects on aging.

J Clin Invest 2013 Aug 25;123(8):3272-91. Epub 2013 Jul 25.

Institute of Pathology, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.

Aging is a major risk factor for a large number of disorders and functional impairments. Therapeutic targeting of the aging process may therefore represent an innovative strategy in the quest for novel and broadly effective treatments against age-related diseases. The recent report of lifespan extension in mice treated with the FDA-approved mTOR inhibitor rapamycin represented the first demonstration of pharmacological extension of maximal lifespan in mammals. Longevity effects of rapamycin may, however, be due to rapamycin's effects on specific life-limiting pathologies, such as cancers, and it remains unclear if this compound actually slows the rate of aging in mammals. Here, we present results from a comprehensive, large-scale assessment of a wide range of structural and functional aging phenotypes, which we performed to determine whether rapamycin slows the rate of aging in male C57BL/6J mice. While rapamycin did extend lifespan, it ameliorated few studied aging phenotypes. A subset of aging traits appeared to be rescued by rapamycin. Rapamycin, however, had similar effects on many of these traits in young animals, indicating that these effects were not due to a modulation of aging, but rather related to aging-independent drug effects. Therefore, our data largely dissociate rapamycin's longevity effects from effects on aging itself.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI67674DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3726163PMC
August 2013

An ENU mutagenesis-derived mouse model with a dominant Jak1 mutation resembling phenotypes of systemic autoimmune disease.

Am J Pathol 2013 Aug 19;183(2):352-68. Epub 2013 Jun 19.

Institute of Experimental Genetics and the German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.

Within the Munich, Germany, N-ethyl-N-nitrosourea mouse mutagenesis program, we isolated a dominant Jak1 mouse model resembling phenotypic characteristics related to autoimmune disease. Chromosomal sequencing revealed a new Jak1 (p.Ser645Pro) point mutation at the conserved serine of the pseudokinase domain, corresponding to a somatic human mutation (p.Ser646Phe) inducing a constitutive activation of the Janus kinase (JAK)/STAT pathway. Morphologically, all Jak1(S645P+/-) mice showed a progressive structural deterioration of ears starting at the age of 4 months, with mononuclear cell infiltration into the dermis. Female mutant mice, in particular, developed severe skin lesions in the neck from 7 months of age. The IHC analysis of these lesions showed an activation of Stat3 downstream to Jak1(S645P) and elevated tissue levels of IL-6. Histopathological analysis of liver revealed a nodular regenerative hyperplasia. In the spleen, the number of Russell bodies was doubled, correlating with significant increased levels of all immunoglobulin isotypes and anti-DNA antibodies in serum. Older mutant mice developed thrombocytopenia and altered microcytic red blood cell counts. Jak1(S645P+/-) mice showed phenotypes related to impaired bone metabolism as increased carboxy-terminal collagen cross-link-1 levels and alkaline phosphatase activities in plasma, hypophosphatemia, and strongly decreased bone morphometric values. Taken together, Jak1(S645P+/-) mice showed an increased activation of the IL-6-JAK-STAT pathway leading to a systemic lupus erythematosus-like phenotype and offering a new valuable tool to study the role of the JAK/STAT pathway in disease development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajpath.2013.04.027DOI Listing
August 2013

Type of uromodulin mutation and allelic status influence onset and severity of uromodulin-associated kidney disease in mice.

Hum Mol Genet 2013 Oct 6;22(20):4148-63. Epub 2013 Jun 6.

Uromodulin-associated kidney disease (UAKD) is a dominant heritable renal disease in humans which is caused by mutations in the uromodulin (UMOD) gene and characterized by heterogeneous clinical appearance. To get insights into possible causes of this heterogeneity of UAKD, we describe the new mutant mouse line Umod(C93F), leading to disruption of a putative disulfide bond which is also absent in a known human UMOD mutation, and compare the phenotype of this new mouse line with the recently published mouse line Umod(A227T). In both mutant mouse lines, which were both bred on the C3H background, the Umod mutations cause a gain-of-toxic function due to a maturation defect of the mutant uromodulin leading to a dysfunction of thick ascending limb of Henle's loop (TALH) cells of the kidney. Umod mutant mice exhibit increased plasma urea and Cystatin levels, impaired urinary concentration ability, reduced fractional excretion of uric acid and nephropathological alterations including uromodulin retention in TALH cells, interstitial fibrosis and inflammatory cell infiltrations, tubular atrophy and occasional glomerulo- und tubulocystic changes, a phenotype highly similar to UAKD in humans. The maturation defect of mutant uromodulin leads to the accumulation of immature uromodulin in the endoplasmic reticulum (ER) and to ER hyperplasia. Further, this study was able to demonstrate for the first time in vivo that the severity of the uromodulin maturation defect as well as onset and speed of progression of renal dysfunction and morphological alterations are strongly dependent on the particular Umod mutation itself and the zygosity status.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/hmg/ddt263DOI Listing
October 2013

Mouse nuclear myosin I knock-out shows interchangeability and redundancy of myosin isoforms in the cell nucleus.

PLoS One 2013 11;8(4):e61406. Epub 2013 Apr 11.

Department of Biology of Cell Nucleus, Institute of Molecular Genetics, ASCR, v.v.i., Prague, Czech Republic.

Background: Nuclear myosin I (NM1) is a nuclear isoform of the well-known "cytoplasmic" Myosin 1c protein (Myo1c). Located on the 11(th) chromosome in mice, NM1 results from an alternative start of transcription of the Myo1c gene adding an extra 16 amino acids at the N-terminus. Previous studies revealed its roles in RNA Polymerase I and RNA Polymerase II transcription, chromatin remodeling, and chromosomal movements. Its nuclear localization signal is localized in the middle of the molecule and therefore directs both Myosin 1c isoforms to the nucleus.

Methodology/principal Findings: In order to trace specific functions of the NM1 isoform, we generated mice lacking the NM1 start codon without affecting the cytoplasmic Myo1c protein. Mutant mice were analyzed in a comprehensive phenotypic screen in cooperation with the German Mouse Clinic. Strikingly, no obvious phenotype related to previously described functions has been observed. However, we found minor changes in bone mineral density and the number and size of red blood cells in knock-out mice, which are most probably not related to previously described functions of NM1 in the nucleus. In Myo1c/NM1 depleted U2OS cells, the level of Pol I transcription was restored by overexpression of shRNA-resistant mouse Myo1c. Moreover, we found Myo1c interacting with Pol II. The ratio between Myo1c and NM1 proteins were similar in the nucleus and deletion of NM1 did not cause any compensatory overexpression of Myo1c protein.

Conclusion/significance: We observed that Myo1c can replace NM1 in its nuclear functions. Amount of both proteins is nearly equal and NM1 knock-out does not cause any compensatory overexpression of Myo1c. We therefore suggest that both isoforms can substitute each other in nuclear processes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0061406PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3623870PMC
October 2013

Modeling hepatic osteodystrophy in Abcb4 deficient mice.

Bone 2013 Aug 29;55(2):501-11. Epub 2013 Mar 29.

Department of Medicine II, Saarland University Medical Center, Homburg, Germany.

Hepatic osteodystrophy (HOD) denotes the alterations in bone morphology and metabolism frequently observed in patients with chronic liver diseases, in particular in case of cholestatic conditions. The molecular mechanisms underlying HOD are only partially understood. In the present study, we characterized the bone phenotypes of the ATP-binding cassette transporter B4 knockout mouse (Abcb4(-/-)), a well-established mouse model of chronic cholestatic liver disease, with the aim of identifying and characterizing a mouse model for HOD. Furthermore, we investigated the influence of vitamin D on bone quality in this model. The bone morphology analyses revealed reduced bone mineral contents as well as changes in trabecular bone architecture and decreased cortical bone densities in Abcb4(-/-) mice with severe liver fibrosis. We observed dysregulation of genes involved in bone remodeling (osteoprotegerin, osteocalcin, osteopontin) and vitamin D metabolism (7-dehydrocholesterol reductase, Gc-globulin, Cyp2r1, Cyp27a1) as well as alterations in calcium and vitamin D homeostasis. In addition, serum RANKL and TGF-β levels were increased in Abcb4(-/-) mice. Vitamin D dietary intervention did not restore the bone phenotypes of Abcb4(-/-) animals. We conclude that the Abcb4(-/-) mouse provides an experimental framework and a preclinical model to gain further insights into the molecular pathobiology of HOD and to study the systemic effects of therapeutic interventions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bone.2013.03.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4075965PMC
August 2013

SMC6 is an essential gene in mice, but a hypomorphic mutant in the ATPase domain has a mild phenotype with a range of subtle abnormalities.

DNA Repair (Amst) 2013 May 18;12(5):356-66. Epub 2013 Mar 18.

Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK.

Smc5-6 is a highly conserved protein complex related to cohesin and condensin involved in the structural maintenance of chromosomes. In yeasts the Smc5-6 complex is essential for proliferation and is involved in DNA repair and homologous recombination. siRNA depletion of genes involved in the Smc5-6 complex in cultured mammalian cells results in sensitivity to some DNA damaging agents. In order to gain further insight into its role in mammals we have generated mice mutated in the Smc6 gene. A complete knockout resulted in early embryonic lethality, demonstrating that this gene is essential in mammals. However, mutation of the highly conserved serine-994 to alanine in the ATP hydrolysis motif in the SMC6 C-terminal domain, resulted in mice with a surprisingly mild phenotype. With the neo gene selection marker in the intron following the mutation, resulting in reduced expression of the SMC6 gene, the mice were reduced in size, but fertile and had normal lifespans. When the neo gene was removed, the mice had normal size, but detailed phenotypic analysis revealed minor abnormalities in glucose tolerance, haematopoiesis, nociception and global gene expression patterns. Embryonic fibroblasts derived from the ser994 mutant mice were not sensitive to killing by a range of DNA damaging agents, but they were sensitive to the induction of sister chromatid exchanges induced by ultraviolet light or mitomycin C. They also accumulated more oxidative damage than wild-type cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dnarep.2013.02.006DOI Listing
May 2013

Clinical Chemistry and Other Laboratory Tests on Mouse Plasma or Serum.

Curr Protoc Mouse Biol 2013 Jun 1;3(2):69-100. Epub 2013 Jun 1.

Institute of Experimental Genetics, German Mouse Clinic, Helmholtz-Zentrum München, German Research Center for Environmental Health, GmbH, Neuherberg, Germany.

Besides hematological analyses, many other parameters, including clinical chemistry and endocrinological values, can be determined from mouse blood samples. For most of these tests, plasma or serum samples are used. Data obtained by these investigations provide indications of genotype effects on metabolism and organ functions. Here we describe in detail the considerations that have to be taken into account to get adequate samples for plasma or serum analyses and the recommended sample processing for different investigations. Furthermore, we describe established methods used in the German Mouse Clinic (GMC) to determine clinical chemical parameters; for more in-depth analysis of specific classes of biomarkers, we provide instructions for ELISAs (sandwich and competitive) as well as LC-MS/MS, focusing on markers associated with bone or steroid metabolism in the mouse as working examples. Curr. Protoc. Mouse Biol. 3:69-100 © 2013 by John Wiley & Sons, Inc.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/9780470942390.mo130043DOI Listing
June 2013

Targeted estrogen delivery reverses the metabolic syndrome.

Nat Med 2012 Dec 11;18(12):1847-56. Epub 2012 Nov 11.

Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.

We report the development of a new combinatorial approach that allows for peptide-mediated selective tissue targeting of nuclear hormone pharmacology while eliminating adverse effects in other tissues. Specifically, we report the development of a glucagon-like peptide-1 (GLP-1)-estrogen conjugate that has superior sex-independent efficacy over either of the individual hormones alone to correct obesity, hyperglycemia and dyslipidemia in mice. The therapeutic benefits are driven by pleiotropic dual hormone action to improve energy, glucose and lipid metabolism, as shown by loss-of-function models and genetic action profiling. Notably, the peptide-based targeting strategy also prevents hallmark side effects of estrogen in male and female mice, such as reproductive endocrine toxicity and oncogenicity. Collectively, selective activation of estrogen receptors in GLP-1-targeted tissues produces unprecedented efficacy to enhance the metabolic benefits of GLP-1 agonism. This example of targeting the metabolic syndrome represents the discovery of a new class of therapeutics that enables synergistic co-agonism through peptide-based selective delivery of small molecules. Although our observations with the GLP-1-estrogen conjugate justify translational studies for diabetes and obesity, the multitude of other possible combinations of peptides and small molecules may offer equal promise for other diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nm.3009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3757949PMC
December 2012
-->