TY - JOUR A1 - Vona, Barbara A1 - Nanda, Indrajit A1 - Shehata-Dieler, Wafaa A1 - Haaf, Thomas T1 - Genetics of Tinnitus: Still in its Infancy JF - Frontiers in Neuroscience N2 - Tinnitus is the perception of a phantom sound that affects between 10 and 15% of the general population. Despite this considerable prevalence, treatments for tinnitus are presently lacking. Tinnitus exhibits a diverse array of recognized risk factors and extreme clinical heterogeneity. Furthermore, it can involve an unknown number of auditory and non-auditory networks and molecular pathways. This complex combination has hampered advancements in the field. The identification of specific genetic factors has been at the forefront of several research investigations in the past decade. Nine studies have examined genes in a case-control association approach. Recently, a genome-wide association study has highlighted several potentially significant pathways that are implicated in tinnitus. Two twin studies have calculated a moderate heritability for tinnitus and disclosed a greater concordance rate in monozygotic twins compared to dizygotic twins. Despite the more recent data alluding to genetic factors in tinnitus, a strong association with any specific genetic locus is lacking and a genetic study with sufficient statistical power has yet to be designed. Future research endeavors must overcome the many inherent limitations in previous study designs. This review summarizes the previously embarked upon tinnitus genetic investigations and summarizes the hurdles that have been encountered. The identification of candidate genes responsible for tinnitus may afford gene based diagnostic approaches, effective therapy development, and personalized therapeutic intervention. KW - twin study KW - complex disorders KW - genetics KW - genetic heterogeneity KW - genome-wide association study (GWAS) KW - hearing loss KW - tinnitus Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170926 VL - 11 IS - 236 ER - TY - JOUR A1 - Pfeiffer, Susanne A1 - Krüger, Jacqueline A1 - Maierhofer, Anna A1 - Böttcher, Yvonne A1 - Klöting, Nora A1 - El Hajj, Nady A1 - Schleinitz, Dorit A1 - Schön, Michael R. A1 - Dietrich, Arne A1 - Fasshauer, Mathias A1 - Lohmann, Tobias A1 - Dreßler, Miriam A1 - Stumvoll, Michael A1 - Haaf, Thomas A1 - Blüher, Matthias A1 - Kovacs, Peter T1 - Hypoxia-inducible factor 3A gene expression and methylation in adipose tissue is related to adipose tissue dysfunction JF - Scientific Reports N2 - Recently, a genome-wide analysis identified DNA methylation of the HIF3A (hypoxia-inducible factor 3A) as strongest correlate of BMI. Here we tested the hypothesis that HIF3A mRNA expression and CpG-sites methylation in adipose tissue (AT) and genetic variants in HIF3A are related to parameters of AT distribution and function. In paired samples of subcutaneous AT (SAT) and visceral AT (VAT) from 603 individuals, we measured HIF3A mRNA expression and analyzed its correlation with obesity and related traits. In subgroups of individuals, we investigated the effects on HIF3A genetic variants on its AT expression (N = 603) and methylation of CpG-sites (N = 87). HIF3A expression was significantly higher in SAT compared to VAT and correlated with obesity and parameters of AT dysfunction (including CRP and leucocytes count). HIF3A methylation at cg22891070 was significantly higher in VAT compared to SAT and correlated with BMI, abdominal SAT and VAT area. Rs8102595 showed a nominal significant association with AT HIF3A methylation levels as well as with obesity and fat distribution. HIF3A expression and methylation in AT are fat depot specific, related to obesity and AT dysfunction. Our data support the hypothesis that HIF pathways may play an important role in the development of AT dysfunction in obesity. KW - gene expression KW - adipose KW - hypoxia-inducible factor 3A KW - adipose tissue dysfunction KW - obesity Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167662 VL - 6 IS - 27969 ER - TY - JOUR A1 - Vona, Barbara A1 - Hofrichter, Michaela A. H. A1 - Schröder, Jörg A1 - Shehata-Dieler, Wafaa A1 - Nanda, Indrajit A1 - Haaf, Thomas T1 - Hereditary hearing loss SNP-microarray pilot study JF - BMC Research Notes N2 - Objectives: Despite recent advancements in diagnostic tools, the genomic landscape of hereditary hearing loss remains largely uncharacterized. One strategy to understand genome-wide aberrations includes the analysis of copy number variation that can be mapped using SNP-microarray technology. A growing collection of literature has begun to uncover the importance of copy number variation in hereditary hearing loss. This pilot study underpins a larger effort that involves the stage-wise analysis of hearing loss patients, many of whom have advanced to high-throughput sequencing analysis. Data description: Our data originate from the Infinium HumanOmni1-Quad v1.0 SNP-microarrays (Illumina) that provide useful markers for genome-wide association studies and copy number variation analysis. This dataset comprises a cohort of 108 individuals (99 with hearing loss, 9 normal hearing family members) for the purpose of understanding the genetic contribution of copy number variations to hereditary hearing loss. These anonymized SNP-microarray data have been uploaded to the NCBI Gene Expression Omnibus and are intended to benefit other investigators interested in aggregating platform-matched array patient datasets or as part of a supporting reference tool for other laboratories to better understand recurring copy number variations in other genetic disorders. KW - copy number variation KW - genotyping arrays KW - hereditary hearing loss KW - illumina KW - infinium HumanOmni1-Quad KW - SNP-microarray Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176239 VL - 11 IS - 391 ER - TY - JOUR A1 - Nanda, Indrajit A1 - Steinlein, Claus A1 - Haaf, Thomas A1 - Buhl, Eva M. A1 - Grimm, Domink G. A1 - Friedman, Scott L. A1 - Meurer, Steffen K. A1 - Schröder, Sarah K. A1 - Weiskirchen, Ralf T1 - Genetic characterization of rat hepatic stellate cell line HSC-T6 for in vitro cell line authentication JF - Cells N2 - Immortalized hepatic stellate cells (HSCs) established from mouse, rat, and humans are valuable in vitro models for the biomedical investigation of liver biology. These cell lines are homogenous, thereby providing consistent and reproducible results. They grow more robustly than primary HSCs and provide an unlimited supply of proteins or nucleic acids for biochemical studies. Moreover, they can overcome ethical concerns associated with the use of animal and human tissue and allow for fostering of the 3R principle of replacement, reduction, and refinement proposed in 1959 by William M. S. Russell and Rex L. Burch. Nevertheless, working with continuous cell lines also has some disadvantages. In particular, there are ample examples in which genetic drift and cell misidentification has led to invalid data. Therefore, many journals and granting agencies now recommend proper cell line authentication. We herein describe the genetic characterization of the rat HSC line HSC-T6, which was introduced as a new in vitro model for the study of retinoid metabolism. The consensus chromosome markers, outlined primarily through multicolor spectral karyotyping (SKY), demonstrate that apart from the large derivative chromosome 1 (RNO1), at least two additional chromosomes (RNO4 and RNO7) are found to be in three copies in all metaphases. Additionally, we have defined a short tandem repeat (STR) profile for HSC-T6, including 31 species-specific markers. The typical features of these cells have been further determined by electron microscopy, Western blotting, and Rhodamine-Phalloidin staining. Finally, we have analyzed the transcriptome of HSC-T6 cells by mRNA sequencing (mRNA-Seq) using next generation sequencing (NGS). KW - liver KW - extracellular matrix KW - hepatic stellate cell KW - myofibroblast KW - fibrosis KW - in vitro model KW - SKY analysis KW - phalloidin stain KW - next generation sequencing KW - STR profile Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-275178 SN - 2073-4409 VL - 11 IS - 11 ER - TY - JOUR A1 - Maierhofer, Anna A1 - Flunkert, Julia A1 - Dittrich, Marcus A1 - Müller, Tobias A1 - Schindler, Detlev A1 - Nanda, Indrajit A1 - Haaf, Thomas T1 - Analysis of global DNA methylation changes in primary human fibroblasts in the early phase following X-ray irradiation JF - PLoS ONE N2 - Epigenetic alterations may contribute to the generation of cancer cells in a multi-step process of tumorigenesis following irradiation of normal body cells. Primary human fibroblasts with intact cell cycle checkpoints were used as a model to test whether X-ray irradiation with 2 and 4 Gray induces direct epigenetic effects (within the first cell cycle) in the exposed cells. ELISA-based fluorometric assays were consistent with slightly reduced global DNA methylation and hydroxymethylation, however the observed between-group differences were usually not significant. Similarly, bisulfite pyrosequencing of interspersed LINE-1 repeats and centromeric α-satellite DNA did not detect significant methylation differences between irradiated and non-irradiated cultures. Methylation of interspersed ALU repeats appeared to be slightly increased (one percentage point; p = 0.01) at 6 h after irradiation with 4 Gy. Single-cell analysis showed comparable variations in repeat methylation among individual cells in both irradiated and control cultures. Radiation-induced changes in global repeat methylation, if any, were much smaller than methylation variation between different fibroblast strains. Interestingly, α-satellite DNA methylation positively correlated with gestational age. Finally, 450K methylation arrays mainly targeting genes and CpG islands were used for global DNA methylation analysis. There were no detectable methylation differences in genic (promoter, 5' UTR, first exon, gene body, 3' UTR) and intergenic regions between irradiated and control fibroblast cultures. Although we cannot exclude minor effects, i.e. on individual CpG sites, collectively our data suggest that global DNA methylation remains rather stable in irradiated normal body cells in the early phase of DNA damage response. KW - DNA methylation KW - fibroblasts KW - methylation KW - alu elements KW - DNA damage KW - epigenetics KW - cancer treatment Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170895 VL - 12 IS - 5 ER - TY - JOUR A1 - Vona, Barbara A1 - Maroofian, Reza A1 - Bellacchio, Emanuele A1 - Najafi, Maryam A1 - Thompson, Kyle A1 - Alahmad, Ahmad A1 - He, Langping A1 - Ahangari, Najmeh A1 - Rad, Abolfazl A1 - Shahrokhzadeh, Sima A1 - Bahena, Paulina A1 - Mittag, Falk A1 - Traub, Frank A1 - Movaffagh, Jebrail A1 - Amiri, Nafise A1 - Doosti, Mohammad A1 - Boostani, Reza A1 - Shirzadeh, Ebrahim A1 - Haaf, Thomas A1 - Diodato, Daria A1 - Schmidts, Miriam A1 - Taylor, Robert W. A1 - Karimiani, Ehsan Ghayoor T1 - Expanding the clinical phenotype of IARS2-related mitochondrial disease JF - BMC Medical Genetics N2 - Background: IARS2 encodes a mitochondrial isoleucyl-tRNA synthetase, a highly conserved nuclear-encoded enzyme required for the charging of tRNAs with their cognate amino acid for translation. Recently, pathogenic IARS2 variants have been identified in a number of patients presenting broad clinical phenotypes with autosomal recessive inheritance. These phenotypes range from Leigh and West syndrome to a new syndrome abbreviated CAGSSS that is characterised by cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia, as well as cataract with no additional anomalies. Methods: Genomic DNA from Iranian probands from two families with consanguineous parental background and overlapping CAGSSS features were subjected to exome sequencing and bioinformatics analysis. Results: Exome sequencing and data analysis revealed a novel homozygous missense variant (c.2625C > T, p.Pro909Ser, NM_018060.3) within a 14.3 Mb run of homozygosity in proband 1 and a novel homozygous missense variant (c.2282A > G, p.His761Arg) residing in an ~ 8 Mb region of homozygosity in a proband of the second family. Patient-derived fibroblasts from proband 1 showed normal respiratory chain enzyme activity, as well as unchanged oxidative phosphorylation protein subunits and IARS2 levels. Homology modelling of the known and novel amino acid residue substitutions in IARS2 provided insight into the possible consequence of these variants on function and structure of the protein. Conclusions: This study further expands the phenotypic spectrum of IARS2 pathogenic variants to include two patients (patients 2 and 3) with cataract and skeletal dysplasia and no other features of CAGSSS to the possible presentation of the defects in IARS2. Additionally, this study suggests that adult patients with CAGSSS may manifest central adrenal insufficiency and type II esophageal achalasia and proposes that a variable sensorineural hearing loss onset, proportionate short stature, polyneuropathy, and mild dysmorphic features are possible, as seen in patient 1. Our findings support that even though biallelic IARS2 pathogenic variants can result in a distinctive, clinically recognisable phenotype in humans, it can also show a wide range of clinical presentation from severe pediatric neurological disorders of Leigh and West syndrome to both non-syndromic cataract and cataract accompanied by skeletal dysplasia. KW - adrenal insufficiency KW - CAGSSS KW - cataracts KW - growth hormone deficiency KW - IARS2 KW - sensory neuropathy KW - sensorineural hearing loss KW - type II esophageal achalasia KW - skeletal dysplasia Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176620 VL - 19 IS - 196 ER - TY - JOUR A1 - Nanda, Indrajit A1 - Schröder, Sarah K. A1 - Steinlein, Claus A1 - Haaf, Thomas A1 - Buhl, Eva M. A1 - Grimm, Domink G. A1 - Weiskirchen, Ralf T1 - Rat hepatic stellate cell line CFSC-2G: genetic markers and short tandem repeat profile useful for cell line authentication JF - Cells N2 - Hepatic stellate cells (HSCs) are also known as lipocytes, fat-storing cells, perisinusoidal cells, or Ito cells. These liver-specific mesenchymal cells represent about 5% to 8% of all liver cells, playing a key role in maintaining the microenvironment of the hepatic sinusoid. Upon chronic liver injury or in primary culture, these cells become activated and transdifferentiate into a contractile phenotype, i.e., the myofibroblast, capable of producing and secreting large quantities of extracellular matrix compounds. Based on their central role in the initiation and progression of chronic liver diseases, cultured HSCs are valuable in vitro tools to study molecular and cellular aspects of liver diseases. However, the isolation of these cells requires special equipment, trained personnel, and in some cases needs approval from respective authorities. To overcome these limitations, several immortalized HSC lines were established. One of these cell lines is CFSC, which was originally established from cirrhotic rat livers induced by carbon tetrachloride. First introduced in 1991, this cell line and derivatives thereof (i.e., CFSC-2G, CFSC-3H, CFSC-5H, and CFSC-8B) are now used in many laboratories as an established in vitro HSC model. We here describe molecular features that are suitable for cell authentication. Importantly, chromosome banding and multicolor spectral karyotyping (SKY) analysis demonstrate that the CFSC-2G genome has accumulated extensive chromosome rearrangements and most chromosomes exist in multiple copies producing a pseudo-triploid karyotype. Furthermore, our study documents a defined short tandem repeat (STR) profile including 31 species-specific markers, and a list of genes expressed in CFSC-2G established by bulk mRNA next-generation sequencing (NGS). KW - liver KW - extracellular matrix KW - hepatic stellate cell KW - myofibroblast KW - fibrosis KW - stress fibers KW - spectral karyotyping KW - rhodamine–phalloidin stain KW - next-generation sequencing KW - STR profile Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288067 SN - 2073-4409 VL - 11 IS - 18 ER -