Genetic and molecular determinants of hereditary hearing loss

The main research focus of the Institute of Pharmacology and Toxicology is the understanding of genetic and molecular mechanisms of syndromic (Pendred syndrome) and non-syndromic malformative hearing loss. In collaboration with the Department of Otolaryngology at SALK (Prof. G. Rasp and Dr. S. Rösch) we have recruited the first Austrian cohort of patients with hearing loss associated with an enlarged vestibular aqueduct (EVA), one of the most common causes of sensorineural hearing loss (Roesch et al. 2018). The SLC26A4 gene, coding for the anion exchanger pendrin, is frequently mutated in the context of Pendred syndrome and non-syndromic EVA. Goal of the research is the precise understanding of the molecular derangements leading to loss of function of pathogenic variants of the pendrin protein, including structural alterations, cellular mis-localization, aberrant turnover and altered gene transcription. The possible contribution of additional genes, including but not limited to connexins GJB2, GJB3 and GJB6, as well as transcription factors such as FOXI1 and POU3F4, in determining malformative hearing loss is also investigated. We also strive to identify novel hearing loss gene and gene modifiers that could explain the disease phenotype in undiagnosed patients. Ultimate goal is to identify novel molecular targets, pathways and strategies for the development of future therapies for hearing loss.

The Institute of Pharmacology and Toxicology holds the approval for diagnostic gene analysis issued by the Bundesministerium für Arbeit, Soziales, Gesundheit und Konsumentenschutz, Austria (approval number: BMASGK-76120/0007-IX/B/16c/2018). The genes analyzed are GJB2, GJB6, SLC26A4 and POU3F4, all of which play a fundamental role in determining sensorineural hearing loss associated with malformations of the inner ear. Additional genes are analysed for research purposes.

Key publications

Bernardinelli E, Roesch S, Simoni E Marino A, Rasp G, Astolfi L, Sarikas A and Dossena S. Novel POU3F4 variants identified in patients with inner ear malformations exhibit aberrant cellular distribution and lack of SLC6A20 transcriptional upregulation. Front Mol Neurosci. Sept 2022.

Roesch, S; Bernardinelli, E; Nofziger, C; Tóth, M; Patsch, W; Rasp, G; Paulmichl, M; Dossena, S; Functional Testing of SLC26A4 Variants-Clinical and Molecular Analysis of a Cohort with Enlarged Vestibular Aqueduct from Austria. Int J Mol Sci. 2018; 19(1):

Pera A, Dossena S, Rodighiero S, Gandía M, Bottà G, Meyer G, Moreno F, Nofziger C, Hernández-Chico C, Paulmichl M. Functional assessment of allelic variants in the SLC26A4 gene involved in Pendred syndrome and nonsyndromic EVA. Proc Natl Acad Sci U S A. 2008;105:18608-18613.

Dossena S, Bizhanova A, Nofziger C, Bernardinelli E, Ramsauer J, Kopp P, Paulmichl M. Identification of allelic variants of pendrin (SLC26A4) with loss and gain of function. Cell Physiol Biochem. 2011;28:467-76.

Oxidative stress in human disease and aging

Reactive Oxygen Species (ROS) are highly reactive chemicals normally produced by the cellular metabolism or following exposure to environmental stressors and xenobiotics. When ROS accumulate beyond the endogenous antioxidant capacity of biological systems, a condition called oxidative stress (OS) ensues. OS underlies several pathophysiological conditions including diabetes mellitus, hearing loss, epilepsy, and aging. The scope of the research is the identification of cellular and molecular targets of OS, with emphasis on ion channel and transporters, and the use of antioxidants to counteract the detrimental effect of OS on a cellular level.

Key publications

Remigante A, Spinelli S, Straface E, Gambardella L, Caruso D, Falliti G, Dossena S, Marino A, Morabito R. Açaì (Euterpe oleracea) Extract Protects Human Erythrocytes from Age-Related Oxidative Stress. Cells. 2022 Aug 3;11(15):2391.

Remigante A, Spinelli S, Basile N, Caruso D, Falliti G, Dossena S, Marino A, Morabito R. Oxidation Stress as a Mechanism of Aging in Human Erythrocytes: Protective Effect of Quercetin. Int J Mol Sci. 2022 Jul 14;23(14):7781.

Remigante A, Spinelli S, Trichilo V, Loddo S, Sarikas A, Pusch M, Dossena S, Marino A, Morabito R. d-Galactose induced early aging in human erythrocytes: Role of band 3 protein. J Cell Physiol. 2022 Feb;237(2):1586-1596.

New teaching media in medicine / Learning analytics

The Internet and the ubiquity of mobile devices open up new didactic opportunities for teaching in higher education. Using quantitative (surveys) and qualitative (focus groups, interviews) methods, we investigate the prevalence and use of digital learning media among today's students and their potential and limitations for knowledge acquisition and transfer. Another research focus is the collection, analysis and evaluation of digital data in the learning context (learning analytics). The goal is the evidence-based development of analysis algorithms in order to dynamically measure the level of knowledge and learning progress of students, to uncover potential problem areas and thus to contribute to the optimization of the teaching and learning process in pharmacology.

Key publications

Kühbeck, F; Berberat, PO; Engelhardt, S; Sarikas, A. Correlation of online assessment parameters with summative exam performance in undergraduate medical education of pharmacology: a prospective cohort study. BMC Med Educ. 2019; 19(1):412

Gutmann J, Kühbeck F, Berberat PO, Fischer MR, Engelhardt S, Sarikas A. Use of learning media by undergraduate medical students in pharmacology: a prospective cohort study. PLoS One. 2015;10:e0122624.

Kräenbring J, Monzon Penza T, Gutmann J, Muehlich S, Zolk O, Wojnowski L, Maas R, Engelhardt S, Sarikas A. Accuracy and completeness of drug information in wikipedia: a comparison with standard textbooks of pharmacology. PLoS One. 2014;9:e106930.

Kühbeck F, Engelhardt S, Sarikas A. OnlineTED.com - a novel web-based audience response system for higher education. A pilot study to evaluate user acceptance. GMS Z Med Ausbild. 2014; 31: Doc5.

The Institute of Pharmacology and Toxicology of Paracelsus Medical University is committed to excellence in teaching and training of medical and pharmacy students. We offer some of the best pharmacology teaching, ranging from lectures and award-winning e-learning tools to lab internships, bachelor, master or PhD theses. 

In collaboration with the Technical University of Munich we have initiated and developed Pharmacases.de, an award-winning peer teaching and open access e-learning platform of pharmacology. Please visit Pharmacases.de for more information.

Prof. Sarikas and his team has developed OnlineTED, a web-based audience response system for higher education. Please visit onlineTED for further information.

The Institute of Pharmacology and Toxicology offers the following online teaching systems:

• Peer-teaching and E-learning project Pharmacases www.pharmacases.de
• PMU300 drug substance list www.pmu300.at
• Online voting system OnlineTED www.onlineted.de

The Institute of Pharmacology and Toxicology participates in the following lectures and seminars at Paracelsus Medical University in Salzburg: 

Human Medicine diploma program

• Lecture “Pharmacology and Toxicology”

Bachelor`s degree study Pharmacy

• Lecture “General Pharmacology A”
• Lecture “General Pharmacology B”

The Institute of Pharmacology and Toxicology offers the following methods and analyses as part of scientific collaboration projects for academic institutions and companies:

Electrophysiology Facility

State of the art patch-clamp set-up composed of an EPC 10 USB amplifier (HEKA, Germany), pneumatic anti-vibrating table, piezoelectric micromanipulator (Scientifica), inverted phase contrast microscope (Motic AE31) equipped with epi-fluorescence and FITC and TRITC emission filters for identification of transfected cells, perfusion system with ALA VC4 valve commander and vacuum pump, Macintosh computer running the PatchMaster acquisition software. Users will have access to a horizontal puller (Sutter Instruments) and a microforge (Narishige) for construction of electrodes and to a biosafety level II cell culture room.

Electrophysiology Facility

Advanced Molecular Imaging Facility

State of the art true confocal system, equipped with 4 lasers (Diode, Argon, DPSS, Helium/Neon) giving 8 excitation lines (405, 458, 476, 488, 496, 514, 561, 633 nm), conventional and resonant scanner for fast acquisition speed, acousto-optical beam splitter (AOBS) for better transmission of the emitted light, acousto-optical tunable filter (AOTF) for fine control of laser power, 3 photomultipliers (PMTs) with spectral detectors for free choice of the emission window and one hybrid detector (hyD) for optimal signal-to-noise ratio acquisition in the red emission region, 5 objectives (10x, 20x, 40x and two 63x) including one 63x water immersion objective for imaging of living samples, temperature, humidity and CO2 control. The confocal microscope is housed in a biosafety level II laboratory room equipped with one biosafety level II hood, one cell culture incubator, fridge, freezer, one small fume hood, one system producing type III deionized water.

Advanced Molecular Imaging Facility

Single Nucleotide Polymorphisms (SNPs) assay

Single-nucleotide polymorphism (SNP) assays determine prevalence and genotype one or more SNPs in a given cohort. Genomic DNA is extracted from no more than 350 ul of peripheral blood using the automated EZ1 Advanced XL platform (Qiagen) and subjected to real-time PCR with allele-specific primers and a probe-based reporter system on a Rotor Gene Q instrument (QIAGEN), which can run 72 samples simultaneously.

Analysis of subcellular localization and protein-protein interaction

Localization of a protein within a given subcellular compartment or co-localization of two or more proteins within a cell are useful strategies to unravel protein function, interaction, and trafficking. Co-localization of native or recombinant proteins in living or fixed cells is quantified and statistically analyzed to disclose differences between protein variants or different conditions. Markers of cellular compartments, including nucleus, plasma membrane, endoplasmic reticulum, Golgi complex, mitochondria, and autophagosomes permit the identification of the specific subcellular compartment of a protein. Fluorescence Resonance Energy Transfer (FRET) permits the identification and characterization of direct interactions beween protein pairs in living or fixed cells in various experimental conditions. Molecular imaging is performed with a Leica TCS SP5 II confocal microscope equipped with 4 lasers and 8 excitation wavelengths (405, 458, 476, 488, 496, 514, 561, 633 nm).

Arnoldas Matulevicius, MA, Erasmus student, Vilnius Gediminas Technical University, Lithuania

Rapolas Jamontas, Master student, Vilnius Gediminas Technical University, Lithuania

Jokubas Siuipys, Erasmus student, Vilnius Gediminas Technical University, Lithuania

Laura Raschke, PMU300 section editor

Christian Puttinger, PMU300 section editor

Andreas Preuschoff, BSc, PMU300 section editor