Biology subjects

Friederike Ehrhart

Publications and source records attributed to Friederike Ehrhart.

3 recordsLinked to original sources

bioRxiv2016

Rett syndrome - biological pathways leading from MECP2 to disorder phenotypes

Rett syndrome (RTT) is a rare disease but still one of the most abundant causes for intellectual disability in females. Typical symptoms are onset at month 6-18 after normal pre-and postnatal development, loss of acquired skills and severe intellectual disability. The type and severity of symptoms are individually highly different. A single mutation in one gene, coding for methyl-CpG-binding protein 2 (MECP2), is responsible for the disease. The most important action of MECP2 is regulating epigenetic imprinting and chromatin condensation, but MECP2 influences many different biological pathways on multiple levels. In this review the known changes in metabolite levels, gene expression and biological pathways in RTT are summarized. It is discussed how they are leading to some characteristic RTT phenotypes and identifies the gaps of knowledge, namely which phenotypes have currently no mechanistic explanation leading back to MECP2 related pathways. As a result of this review the visualization of the biologic pathways showing MECP2 up-and downstream regulation was developed and published on WikiPathways.

Neuroscience↗

bioRxiv2016

Low parental melatonin levels increases autism spectrum disorder risk in children

Low melatonin levels are a frequent finding in autism spectrum disorder (ASD) patients. Melatonin is important for normal neurodevelopment and embryonic growth and highly effective in protecting DNA from oxidative damage. Melatonin deficiency, possibly due to low CYP1A2 activity, could be an etiologic factor. As the fetus does not produce melatonin, low maternal melatonin levels should be involved. We measured 6-sulfatoxymelatonin in urine of 60 mothers of a child with ASD that attended our sleep clinic for people with an intellectual disability (ID), and asked for coffee consumption habits, as these are known to be related to CYP1A2 activity. 6-Sulfatoxymelatonin levels were significantly lower in mothers than in controls (p = 0.005), as well as evening coffee consumption (p = 0.034).\n\nAbbreviations

Neuroscience↗

bioRxiv2015

Current systems biology approaches in hazard assessment of nanoparticles

The amount of nanoparticles (NPs) in human environment is increasing. The main sources are the increased introduction in consumer products and air pollution (diesel exhaust). It is meanwhile common knowledge that NPs behave differently as bulk material because of their nano-size. This leads in general to a higher reactivity and some other changed properties, e.g. solubility, surface potential, conductivity, and, to different effects on biological systems. The main impacts of NPs on a cellular and organism level are meanwhile well known: release of toxic ions, increased oxidative stress, and inflammation. Beside these, there is increasing evidence that NPs, especially in low dose/long exposure scenarios, affect biological systems in a broader way, interact with drugs, and exacerbate the effects of diseases. To investigate these effects systems biology approaches are the method of choice. This review summarizes the state of the art of nanoparticle effects on cells and organisms and demonstrate the add value of systems biology investigations to NP hazard assessment.\n\nAbbreviations: nanoparticle (NP), carbon nanotube (CNT), single walled carbon nanotube (SWCNT), multi walled carbon nanotube (MWCNT), ADME (adsorption, distribution, metabolization, excretion), PAMAM (poly(amidoamine)),

Systems Biology↗