Biology subjects

Hesse, M.

Publications and source records attributed to Hesse, M..

5 recordsLinked to original sources

bioRxiv2026

Pharmacokinetics and Efficacy of the FimH Inhibitor Sibofimloc in Preventing Necrotizing Enterocolitis in Preterm Piglets

Necrotizing enterocolitis (NEC) is a disease in preterm infants associated with an increased abundance of Enterobacteriaceae. FimH, a mannose-binding adhesin on Enterobacteriaceae type 1 fimbriae, mediates mucosal attachment and TLR4-dependent inflammatory cascades. We evaluated the safety, pharmacokinetics, and efficacy of an oral FimH inhibitor (Sibofimloc) to reduce Enterobacteriaceae colonization and prevent NEC in preterm piglets. We performed a 9-d dose-escalation safety study (10, 25, 50 mg/kg BID) assessing absorption and tolerability and a 10-d randomized efficacy study. Piglets in the efficacy study received an infant formula diet with or without oral sibofimloc (40 mg/kg BID), or donor human milk (DHM) as a healthy control. NEC incidence, tissue histopathology, and gut microbiota composition via metagenomic whole-genome sequencing (WGS) were evaluated. Systemic exposure data reveal that sibofimloc was dose-dependently absorbed, while plasma levels decreased from postnatal day 2 to day 8, indicating reduced drug absorption with maturation of the intestinal barrier. Treatment with sibofimloc did not reduce NEC incidence (100% in sibofimloc in formula controls) or severity, whereas DHM-fed piglets experienced 0% NEC. Sibofimloc-treated animals exhibited significantly reduced crypt depths, demonstrating heightened mucosal injury and impaired regenerative capacity. WGS revealed that sibofimloc-treated animals maintained a gut luminal microbiota composition similar to untreated formula controls, dominated by Clostridium perfringens (C. perfringens). Selective targeting of FimH-expressing Enterobacteriaceae was insufficient to prevent NEC or alter the gut microbiota in this preterm piglet model, underscoring the complexity of NEC-associated microbial communities and suggesting that additional microbial targets and other colonization mechanisms may contribute to disease development.

microbiology↗

bioRxiv2026

LRRK2/LRRK1 interactions modulate Rab7 activity and inhibit lysosomal exocytosis

Mutations in the LRRK2 gene are the most common genetic cause of both familial and sporadic Parkinsons disease (PD). LRRK2 belongs to the leucine-rich repeat kinase (LRRK) family. Two members of the LRRK family exist in humans (LRRK1 and LRRK2). Although there is strong structural similarity between the two proteins, they have attracted very different levels of attention by the scientific community owing to the strong association between LRRK2 and PD. In contrast, the role of LRRK1 is relatively unexplored. LRRK2 is also known to regulate endolysosomal function, but its precise role in this process remains incompletely understood. Our study investigated the interaction between LRRK1 and LRRK2 under different cellular conditions, uncovering their role in modulating the endolysosomal system. We found that LRRK1 and LRRK2 interact and modulate each others activity, and that this interaction is reduced under starvation conditions. We also found that LRRK1 and LRRK2 have contrasting effects on lysosomal size, impacting on lysosomal exocytosis. Together, our findings suggest that LRRK2 regulates endolysosomal homeostasis, at least in part, by modulating LRRK1. Our findings offer new insight into the molecular mechanisms associated with lysosomal function and, ultimately, we anticipate this knowledge will help us better understand the molecular crosstalk between LRRK kinases and their contribution to PD pathogenesis. Graphical abstractStarvation reduces the interaction between LRRK2 and LRRK1 due to a conformational change in LRRK2. Under normal conditions, LRRK2/LRRK1 interaction enhances LRRK1 activity, leading to increased phosphorylation of Rab7. Disruption of the Rab7 cycle impairs lysosomal homeostasis, leading to lysosomal accumulation and an increase in lysosomal diameter. This enlargement negatively impacts lysosomal exocytosis. Created with BioRender.com. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=176 SRC="FIGDIR/small/731951v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@13ce58forg.highwire.dtl.DTLVardef@1034543org.highwire.dtl.DTLVardef@1b84096org.highwire.dtl.DTLVardef@198598f_HPS_FORMAT_FIGEXP M_FIG C_FIG

Cell Biology↗

bioRxiv2024

Efficient targeting of heart lesions with cardiac myofibroblasts: Combined gene and cell therapy enhanced by magnetic steering

1The cardiac scar is a collagen-rich area, which is populated by myofibroblasts and has proven little amenable for therapeutic interventions. Herein, we have established an efficient targeting strategy for cardiac lesions by genetically manipulating embryonic cardiac myofibroblasts (mFB) in vitro, load the cells with magnetic nanoparticles and inject these into infarcted mouse hearts using magnetic steering. This yields strongly increased numbers ([~]4 fold compared to other cell types) of engrafted mFB. The injected mFB and endogenous myofibroblast (endoFB) population remain separate in the scar, but grafted mFB enhance the proliferation rate of endoFB by [~]4 fold. We also tested the functional impact of this approach by grafting lentiviral (LV)-transduced Connexin43 (Cx43) overexpressing mFB into the cardiac lesion. Prominent engraftment of Cx43+ mFB provides strong protection against post-infarct ventricular tachycardia (VT) in vivo, as VT incidence is reduced by [~]50 % at two and eight weeks after cell injection. Thus, ex vivo gene and subsequent in vivo cell therapy combined with magnetic steering of cardiac mFB enable efficient functional targeting of the cardiac scar.

physiology↗

bioRxiv2021

Deubiquitinase-Targeting Chimeras for Targeted Protein Stabilization

Targeted protein degradation is a powerful therapeutic modality that uses heterobifunctional small-molecules to induce proximity between E3 ubiquitin ligases and target proteins to ubiquitinate and degrade specific proteins of interest. However, many proteins are ubiquitinated and degraded to drive disease pathology; in these cases targeted protein stabilization (TPS), rather than degradation, of the actively degraded target using a small-molecule would be therapeutically beneficial. Here, we present the Deubiquitinase-Targeting Chimera (DUBTAC) platform for TPS of specific proteins. Using chemoproteomic approaches, we discovered the covalent ligand EN523 that targets a non-catalytic allosteric cysteine C23 in the K48 ubiquitin-specific deubiquitinase OTUB1. We then developed a heterobifunctional DUBTAC consisting of our EN523 OTUB1 recruiter linked to lumacaftor, a drug used to treat cystic fibrosis that binds {Delta}F508-CFTR. We demonstrated proof-of-concept of TPS by showing that this DUBTAC robustly stabilized {Delta}F508-CFTR in human cystic fibrosis bronchial epithelial cells in an OTUB1-dependent manner. Our study underscores the utility of chemoproteomics-enabled covalent ligand discovery approaches to develop new induced proximity-based therapeutic modalities and introduces the DUBTAC platform for TPS. Editorial summaryWe have developed the Deubiquitinase Targeting Chimera (DUBTAC) platform for targeted protein stabilization. We have discovered a covalent recruiter against the deubiquitinase OTUB1 that we have linked to the mutant {Delta}F508-CFTR targeting cystic fibrosis drug Lumacaftor to stabilize mutant CFTR protein in cells.

biochemistry↗

bioRxiv2021

Visualizing multi-protein patterns at the synapse of neuronal tissue with DNA-assisted single-molecule localization microscopy

The development of super-resolution microscopy (SRM) has widened our understanding of biomolecular structure and function in biological materials. Imaging multiple targets within a single area would elucidate their spatial localization relative to the cell matrix and neighboring biomolecules, revealing multi-protein macromolecular structures and their functional co-dependencies. SRM methods are, however, limited to the number of suitable fluorophores that can be imaged during a single acquisition as well as the loss of antigens during antibody washing and restaining for organic dye multiplexing. We report the visualization of multiple protein targets within the pre- and postsynapse in 350-400 nm thick neuronal tissue sections using DNA-assisted single-molecule localization microscopy. Using antibodies labeled with short DNA oligonucleotides, multiple targets are visualized successively by sequential exchange of fluorophore-labeled complementary oligonucleotides present in the imaging buffer. The structural integrity of the tissue is maintained owing to only a single labelling step during sample preparation. Multiple targets are imaged using a single laser wavelength, minimizing chromatic aberration. This method proved robust for multi-target imaging in semi-thin tissue sections, paving the way towards structural cell biology with single-molecule super-resolution microscopy.

biophysics↗