Biology subjects

Reischl, S.

Publications and source records attributed to Reischl, S..

3 recordsLinked to original sources

bioRxiv2024

Orally delivered biodegradable targeted inflammation resolving pectin-coated nanoparticles induce anastomotic healing post intestinal surgery

Although medical treatment is sucessful in most cases in patients with inflammatory bowel diseases (IBD), a percentage of patients require surgical resection of diseased bowel segments at least once in their lifetime. Healing success of the intestinal anastomosis is at high risk, especially in presence of acute inflammation. Failure of anastomotic healing is a life-threatening complication and causes high socioeconomic costs. Common anti-inflammatory medications can have detrimental effects on wound healing. Thus, targeted perioperative therapeutics supporting anastomotic healing during colitis are an urgent medical need. Here, we develop a novel basal membrane targeted controlled release, pectin-coated polymeric nanoparticle (NP) encapsulating a highly potent inflammation resolving mediator, the peptide Ac2-26. These NPs can undergo gastric passage and facilitate localized release of the therapeutic peptide in the colon via degradation of their pectin-chitosan coating by microbial pectinases, which subsequently exposes a collagen IV targeted NP surface, allowing for further binding and retention of the NPs at the intestinal wound. To test these NPs, we used a murine surgical model combining the formation of an intestinal anastomosis with the induction of a preoperative colitis by dextran sodium sulfate. In this model, perioperative administration of pectin-chitosan coated NPs containing Ac2-26 (P-C-Col IV-Ac2-26-NP) led to the reduction of colitis activity in the postoperative phase. Macroscopic wound closure was improved by P-C-Col IV-Ac2-26-NP treatment as evaluated by endoscopy and intraabdominal adhesion scoring. Microscopic analysis of the healing process showed an improved semiquantitative healing score in the treatment group. In this proof-of-concept study we demonstrate that novel P-C-Col IV-Ac2-26-NP could be a promising and clinically feasible perioperative treatment strategy for IBD patients. TOC graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=135 SRC="FIGDIR/small/569918v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@14f726dorg.highwire.dtl.DTLVardef@e1739aorg.highwire.dtl.DTLVardef@16ca7d0org.highwire.dtl.DTLVardef@7d87fe_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

RNA splicing modulator induces peripheral neuropathy with increased neurofilament light chain levels via p53 signaling

RNA splicing modulators are a new class of small molecules with the potential to modify the expression levels of proteins. A recent clinical trial investigating the splicing modulator branaplam for Huntingtons disease to lower huntingtin levels was terminated due to the development of peripheral neuropathy. Here, we describe how branaplam leads to this adverse effect. On a cellular level, branaplam disrupts neurite integrity reflected by elevated neurofilament light chain levels in human induced pluripotent stem cell (iPSC)-derived motor neurons (iPSC-MN). Branaplam does not target neuropathy-associated genes. However, transcription factor binding site enrichment analysis indicates p53 activation. P53 activation upon branaplam treatment in iPSC-MN is linked to increased nucleolar stress, thereby enhanced expression of the neurotoxic p53-target gene BBC3. These findings illustrate that RNA splicing modulators may have clinically relevant off-target effects, implying the necessity of comprehensive pre-screening in human models prior to executing clinical trials. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=188 SRC="FIGDIR/small/551640v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@9b2cbdorg.highwire.dtl.DTLVardef@1964746org.highwire.dtl.DTLVardef@121612corg.highwire.dtl.DTLVardef@72c6a6_HPS_FORMAT_FIGEXP M_FIG C_FIG One Sentence SummaryPredicting side effects of RNA splicing modulator branaplam leading to neurotoxicity via nucleolar stress, p53 activation, and axonal degeneration.

pharmacology and toxicology↗

bioRxiv2020

Live-cell imaging of circadian clock protein dynamics in CRISPR-generated knock-in cells

The current model of the mammalian circadian oscillator is predominantly based on data from genetics and biochemistry experiments, while the cell biology of circadian clocks is still in its infancy. Here, we describe a new strategy for the efficient generation of knock-in reporter cell lines using CRISPR technology that is particularly useful for lowly or transiently expressed genes, such as those coding for circadian clock proteins. We generated single and double knock-in cells with endogenously expressed PER2 and CRY1 fused to fluorescent proteins, which allowed to simultaneously monitor the dynamics of CRY1 and PER2 proteins in live single cells. Both proteins are highly rhythmic in the nucleus of human cells with PER2 showing a much higher amplitude than CRY1. Surprisingly, CRY1 protein is nuclear at all circadian times indicating the absence of circadian gating of nuclear import. Furthermore, in the nucleus of individual cells CRY1 abundance rhythms are phase-delayed ([~]5 hours), and CRY1 levels are much higher (>6 times) compared to PER2 questioning the current model of the circadian oscillator. Our knock-in strategy will allow the generation of additional single, double or triple knock-in cells for circadian clock proteins, which should greatly advance our understanding about the cell biology of circadian clocks.

cell biology↗