Biology subjects

Mayr, L.

Publications and source records attributed to Mayr, L..

4 recordsLinked to original sources

bioRxiv2022

Adaptation to ER-stress via serine glycine metabolism licences STING signalling and CMV control in intestinal epithelial cells

Inflammatory bowel diseases (IBD) are characterized by chronic relapsing inflammation of the gastrointestinal tract. While the molecular causality between endoplasmic reticulum (ER) stress and intestinal inflammation is widely accepted, the metabolic consequences of chronic ER-stress on the pathophysiology of IBD remain unclear. By using in vitro, ex vivo, in vivo mouse models and patient datasets, we identified a distinct polarisation of the mitochondrial one-carbon (1C) metabolism and a fine-tuning of the amino acid uptake in intestinal epithelial cells tailored to support GSH and NADPH metabolism upon chronic ER-stress. This metabolic phenotype strongly correlates with IBD severity and therapy-response. Mechanistically, we uncover that both chronic ER-stress and serine limitation disrupt cGAS/STING-signalling, impairing the epithelial response against viral and bacterial infection, fuelling experimental enteritis. Consequently, antioxidant treatment restores STING function and virus control. Collectively, our data highlight the importance of the plasticity of serine metabolism to allow proper cGAS/STING-signalling and innate immune responses upon chronic inflammation in the gut.

cell biology↗

bioRxiv2021

Interleukin-11 plays a key role in human and mouse alcohol-related liver disease

BackgroundAlcoholic hepatitis (AH) reflects acute exacerbation of alcoholic liver disease (ALD) and is a growing healthcare burden worldwide with limited treatment options. Interleukin-11 (IL-11) is a pro-fibrotic, pro-inflammatory cytokine with increasingly recognized toxicities in parenchymal and epithelial cells. AimThe aim of this study was to explore the prognostic value of IL-11 serum levels in patients suffering from AH and cirrhosis of various etiology and to understand the role of IL-11 in experimental ALD. MethodsIL-11 serum concentration and tissue expression was determined in a cohort comprising 50 patients with AH, 110 patients with cirrhosis and 19 healthy volunteers. Findings were replicated in an independent patient cohort including 186 patients. Ethanol-fed wildtype mice were treated with a neutralizing murine IL-11 receptor-antibody (anit-IL11RA) and thereafter examined for severity signs and markers of ALD. ResultsHuman IL-11 serum concentration and liver tissue expression increased with severity of liver disease and were most pronounced in AH. In a multivariate Cox-regression, a serum level above 6.4 picograms/milliliter was a MELD independent risk factor for transplant-free liver disease survival in patients with compensated and decompensated cirrhosis. Findings were confirmed in an independent cohort. In mice, severity of alcohol-induced liver inflammation was positively correlated to enhanced hepatic IL-11 expression. Pretreatment with a neutralizing anti-IL11RA inhibited hepatic inflammation and mice were protected from ethanol-induced liver injury. In comparison to IgG-control, ethanol-fed mice treated with anti-IL11RA showed decreased steatosis, hepatic neutrophil infiltration, and expression of pro-inflammatory cytokines. ConclusionIL-11 plays a crucial role in the pathogenesis of ALD and could serve as an independent prognostic factor for transplant-free survival. Blocking IL-11 signaling might be a therapeutic option in human ALD, particularly AH.

immunology↗

bioRxiv2020

ObLiGaRe doxycycline Inducible (ODIn) Cas9 system driving pre-clinical drug discovery, from design to cancer treatment

The CRISPR-Cas9 system has increased the speed and precision of genetic editing in cells and animals. However, model generation for drug development is still expensive and time-consuming, demanding more target flexibility and faster turnaround times with high reproducibility. We have generated a tightly controlled ObLiGaRe doxycycline inducible SpCas9 (ODInCas9) transgene. Targeted ObLiGaRe resulted in functional integration into both human and mouse cells culminating in the generation of the ODInCas9 mouse. Genomic editing can be performed in cells of various tissue origins without any detectable gene editing in the absence of doxycycline. Somatic in vivo editing can model non-small cell lung cancer (NSCLC) adenocarcinomas, enabling treatment studies to validate the efficacy of candidate drugs. The ODInCas9 mouse can be utilized for robust and tunable genome editing allowing for flexibility, speed and uniformity at reduced cost, leading to high throughput and practical preclinical in vivo therapeutic testing.

genomics↗

bioRxiv2018

In vivo CRISPR-Cas gene editing with no detectable genome-wide off-target mutations

CRISPR-Cas genome-editing nucleases hold substantial promise for human therapeutics1-5 but identifying unwanted off-target mutations remains an important requirement for clinical translation6, 7. For ex vivo therapeutic applications, previously published cell-based genome-wide methods provide potentially useful strategies to identify and quantify these off-target mutation sites8-12. However, a well-validated method that can reliably identify off-targets in vivo has not been described to date, leaving the question of whether and how frequently these types of mutations occur. Here we describe Verification of In Vivo Off-targets (VIVO), a highly sensitive, unbiased, and generalizable strategy that we show can robustly identify genome-wide CRISPR-Cas nuclease off-target effects in vivo. To our knowledge, these studies provide the first demonstration that CRISPR-Cas nucleases can induce substantial off-target mutations in vivo, a result we obtained using a deliberately promiscuous guide RNA (gRNA). More importantly, we used VIVO to show that appropriately designed gRNAs can direct efficient in vivo editing without inducing detectable off-target mutations. Our findings provide strong support for and should encourage further development of in vivo genome editing therapeutic strategies.

molecular biology↗