Dept. of Systems Biology and Bioinformatics is a part of the University of Rostock, Germany Universität Rostock

Dr. Johannes Wollbold

Image: Dr. Johannes Wollbold

Current Projects

Reactive Oxygen Species and the Dynamics of Ageing. A Mitochondrial Multi-gene, Multi-organ Approach (ROSAge)
Aging
It is widely assumed that mitochondrial dysfunction and subsequent ROS (Reactive Oxygen Species) production are crucial players in ageing. However, the specific role of mitochondrial pathways in the onset and progression of degeneration and ageing is still unclear, as is the degree of interplay among organs in the ageing process. We hypothesise that impairing mitochondrial respiratory function leads to oxidative stress and ROS production. This induces DNA damage, inflammation and, ultimately, cell senescence and ageing.
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Research Interest

Production of reactive oxygen species (ROS) in the respiratory chain

"I aim at connecting interdisciplinary knowledge in order to understand the logics of free radical production and ageing."

The classical free radical theory of aging assumes that oxidative damage by reactive oxygen species (ROS) accumulates with age in a self-enhancing process. The theory has been confirmed by many experiments in various species. However, it is seriously challenged since several years. In this ambiguous situation, I am collecting and ordering existing knowledge focusing on the questions: Under which conditions do ROS increase with age? Do they always cause damage, or what are beneficial effects? Is a high lifespan observed in spite of a certain level of nonfunctional DNA, proteins or lipids?

In order to shed light on these questions, I developed a specific method of knowledge base construction. Data reported in literature or collected by our experimental partners of the ROSAge consortium is formalized as "Ripple Down Rules" (RDR), a structure of general rules and exceptions. This rule set is further validated and completed by the attribute exploration algorithm [1] of Formal Concept Analysis: Implicational rules proposed by the algorithm are accepted or counterexamples are given, if necessary after supplementary literature or data queries. Thus, a minimal rule base is defined systematically. From this base, all implications valid according to the available knowledge can be derived logically (completeness). I am adapting the open source software conexp-clj (written in the LISP dialect Clojure) accordingly.

Furthermore, my special attention is directed towards physiological conditions where ROS have a positive role for signalling, e.g. in the immune system. Recent findings suggest that - in contrast to other tissues - in inflamed pancreatic acinar cells pro-apoptotic effects of ROS dominate their effect on mitochondrial pore opening leading finally to necrosis.

For this situation, we developed a model in multi-valued logic (implemented in R, published 2014 in BMC Systems Biology (see below) and in the BioModels database, after conversion to the SBML-qual standard), based on published data and supplementary measurements by the department of Gastroenterology Rostock. The investigation of beneficial ROS signaling contributes to a more differentiated knowledge of its deregulation and of real ROS influences on ageing. Moreover, we hope to better understand the effect of ROS on enhanced apoptosis as a property of ageing.
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[1] German Wikipedia page co-authored by me, with some English literature and weblinks.

Academic Background

2011 - 2015
PostDoc, Systems Biology and Bioinformatics
University of Rostock, Germany

2011
Attribute Exploration of Gene Regulatory Processes
PhD (Dr. rer. nat.) in Computer Science
Bio Systems Analysis Group, University of Jena, Germany

2010 - 2011
Steinbeis Transfer Center for Proteome Analysis, Rostock

2008 - 2009
Institute of Algebra, University of Dresden, Germany

2005 - 2007
Systems Biology / Bioinformatics,  Leibniz Institute for Natural Product Research and Infection Biology - Hans-Kn

Publications

Wollbold J, Jaster R, Müller S, Rateitschak K, Wolkenhauer O
Anti-inflammatory effects of reactive oxygen species – a multi-valued logical model validated by formal concept analysis

BMC Systems Biology, 8:101  doi:10.1186/s12918-014-0101-7.
open access

Wollbold J, Köhling R, Borchmann D
Attribute Exploration with Proper Premises and Incomplete Knowledge Applied to the Free Radical Theory of Ageing

In: Glodeanu C, Kaytoue M, Sacarea C: Formal Concept Analysis. LNCS 8478, Springer 2014, p. 268-283.

Contact Details

Systems Biology and Bioinformatics
Ulmenstrasse 69 (building 3, 3rd floor)
18057 Rostock, Germany
Room 411


phone: +49 381 498-7575
fax: +49 381 498-7572
mail: jwollbold(at]gmx[point)de

Collaborators & Partners

Federal Ministry for Education and Research (BMBF)
University of Rostock
Rostock/Germany
Prof. Robert Jaster
Dep. of Gastroenterology
Medical Faculty
University of Rostock
arivis GmbH