AimsO(6)-methylguanine-DNA-methyltransferase (MGMT) promoter methylation is a high predictive factor for therapy results of temozolomide in patients with glioma. The objective of this work was to analyse the impact of MGMT promoter methylation in patients with primary diagnosed glioblastoma (GBM) relating to survival using a quantitative method (methylation quantification of endonuclease-resistant DNA, MethyQESD) by verifying a cut-off point for MGMT methylation provided by the literature (</≥10%) and calculating an optimal cut-off.Methods67 patients aged 70 years or younger, operated between January 2013 and December 2015, with newly diagnosed IDH wild-type GBM and clinical follow-up were retrospectively investigated in this study. A known MGMT promoter methylation status was the inclusion criteria.ResultsMedian overall survival (OS) was 16.9 months. Patients who had a methylated MGMT promoter region of ≥10% had an improved OS compared with patients with a methylated promoter region of <10% (p=0.002). Optimal cut-off point for MGMT promoter methylation was 11.7% (p=0.012).ConclusionThe results confirm that the quantitative level of MGMT promoter methylation is a positive prognostic factor in newly diagnosed patients with GBM. The cut-off provided by the literature (</≥10%) and the calculated optimal cut-off value of 11.7% give a statistically significant separation. Hence, MethyQESD is a reliable method to calculate MGMT promoter methylation in GBM.

Satellite cells (SCs) are stem cells and myogenic determinants of skeletal muscles. Aldehyde Dehydrogenase 1 (ALDH1) activity correlates with myogenic properties of SCs, and the paralogues ALDH1A1 and ALDH1A3 are expressed in human SCs. ALDH1 serves as the pacemaker enzyme in retinoic acid (RA)-driven differentiation and acts as a ROS scavenger to protect against oxidative damage. However, the underlying molecular mechanisms of ALDH1 regulation in SCs and its impact on RA-driven myogenesis remain elusive. We analysed the impact of ALDH1A1 and ALDH1A3 activity on myogenesis of the murine myoblast cell line C2C12. Both, ALDH1A1 and ALDH1A3 are pivotal factors in myogenic differentiation, since CRISPR/Cas9-edited single ALDH1a1 or ALDH1a3 knock-out, respectively, impaired experimentally induced myogenic differentiation, as assessed by serum withdrawal, while successive recombinant re-expression of ALDH1A1 or ALDH1A3, respectively, in the corresponding ALDH1 paralogue single knock-out cell lines, recovered the differentiation potential. Loss of differentiation in both single knock-out cell lines was restored by treatment with RA analogue TTNPB, while RA receptor antagonization by AGN 193109 inhibited differentiation of wildtype cell lines, supporting the idea that RA receptor-signalling is pivotal for myogenic differentiation which is accomplished by the ALDH1 paralogues. However, overexpression of ALDH1 paralogues, or disulfiram treatment to inhibit ALDH1 enzymatic activity, not only increased ALDH1A1 and ALDH1A3 protein levels but also induced subsequent differentiation of C2C12 cells independently from serum withdrawal, indicating that ALDH1 dependent myogenic differentiation relies on different cellular conditions, and that yet unknown, RA-independent signalling pathways, may also be involved in myogenic differentiation.

BACKGROUND Sports-related mild traumatic brain injuries (sports related concussion, SRC) have received increasing attention since neurodegenerative processes have been linked to repetitive SRCs. Return-to-Play (RTP) rules have been established for medical advised return into sports activities after concussion, but it is not clear if these rules also reach the sports clubs and its young athletes. OBJECTIVE In youth sports, athletes and their parents search the internet for advice after SRC. We therefore investigated which websites of German sports associations and clubs in football (soccer), handball and rugby offer information on SRC and RTP rules. METHODS The systematic analysis included websites of local football, handball and rugby clubs in two comparable regions in Southern Bavaria and Lower Saxony. The websites of the regional and the German umbrella associations were also included into the study. Eight criteria of the revised Sport Concussion Consensus Statement served as standard for the evaluation according to the protocol published by Swallow et al. (J Neurosurg Pediatr, 2018). RESULTS No information on RTP rules or the topic “sports-related brain injuries” could be found on any of the clubs’ websites. Only the Bavarian Football Association and the Rugby Association sporadically provided information on the topic. The German umbrella associations in football and rugby take up international documents and regulations of the European and the world associations. No information could be found at the German Handball Association. CONCLUSIONS The topics of sports-related brain injuries and RTP rules are mostly neglected on the analysed Websites. This is remarkable, as there are clearly defined consensus guidelines which are widely accepted in international comparison. Especially in the USA, online information on this topic has become standard.

Background Satellite cells (SC) constitute the stem cell population of skeletal muscle tissue and are determinants for myogenesis. Aldehyde Dehydrogenase 1 (ALDH1) enzymatic activity correlates with myogenic properties of SCs and, recently, we could show co-localization of its isoforms ALDH1A1 and ALDH1A3 in SCs of human skeletal muscle. ALDH1 is not only the pacemaker enzyme in retinoic acid signaling and differentiation, but also protecting cell maintenance against oxidative stress products. However, the molecular mechanism of ALDH1 in SC activation and regulation of myogenesis has not yet been characterized. Method Human RH30 and murine C2C12 myoblast cell lines were investigated in regard of ALDH1A1 and ALDH1A1 expression in myogenesis using Western Blot, Immunofluorescence and Aldefluor Assay. Results Here, we show, that isoforms ALDH1A1 and ALDH1A3 are pivotal factors in the process of myogenic differentiation, since ALDH1A1 knock-out and ALDH1A3 knock-out, respectively, impaired differentiation potential. Recombinant re-expression of ALDH1A1 and ALDH1A3, respectively, in corresponding ALDH1-isoform knock-out cells recovered their differentiation potential. Most interestingly, the chemical inhibition of enzymatic activity by disulfiram leads to ALDH1A1 and ALDH1A3 protein upregulation and subsequent myogenic differentiation. Conclusion Our findings indicate that ALDH1A1 and ALDH1A3 proteins are important for myogenic differentiation and, therefore, seem to be essential activators and regulators of SCs.