Biology subjects

Haller, S. T.

Publications and source records attributed to Haller, S. T..

4 recordsLinked to original sources

bioRxiv2026

Exploring the Mechanism of Na⁺/K⁺-ATPase (NKA) and 20-HETE Ligand Interactions by in-silico modeling

The Na+/K+-ATPase (NKA) regulates ion balance in the kidney and influences cellular processes like proliferation and apoptosis through its signal transduction. The endogenous ligand 20-Hydroxyeicosatetraenoic acid (20-HETE) contributes to inflammation and fibrosis in chronic kidney disease (CKD) and inhibits NKA activity in renal tubules. However, the molecular mechanism of this interaction remains unclear. In this study, we used in-silico approach to investigate the potential interaction between 20-HETE and NKA. Various ligands, including known NKA ligands such as cardiotonic steroids (CTS), 20-HETE, and negative controls, were docked using rigid and Induced Fit Docking to predict the affinity of the ligands toward NKA. Binding free energy calculations with the Prime Molecular mechanics with generalized Born and surface area (Prime MM/GBSA) tools were used to confirm the involvement of key amino acids in ligand-receptor interactions. The docking analyses revealed that 20-HETE exhibited a binding affinity comparable to negative control, with some differences between rigid and induced fit docking. Binding free energy data highlighted key amino acids in the 20-HETE and NKA interaction. Interaction fingerprint and mutations such as Ala330Gly and Val329Ala significantly reduced binding free energy, while Thr804Ala showed a notable decrease, underscoring the potential importance of these amino acids in ligand stabilization. These findings provide computational evidence supporting potential direct interaction between 20-HETE and NKA and identify candidate residues for future experimental validation.

bioinformatics↗

bioRxiv2025

Microcystin-LR aerosol exposure increases inflammatory drivers of asthma, Evidence of an NF-κB amplification mechanism

Microcystin-LR (MC-LR) is one of a large family of cyanotoxins which are naturally produced by cyanobacteria within harmful algal blooms occurring in bodies of water globally. Early findings of the toxicity of such blooms stemmed from fatalities of livestock drinking from affected water. Since then, various toxins have been identified such as the microcystins. Microcystin-LR has been studied as a representative congener due to its abundance and toxicity. While there have been extensive studies of microcystin-LR by oral route exposure, we have turned our attention to inhalation route exposure due to the recent findings of microcystin-containing lake and sea-spray aerosol. We have shown inflammatory outcomes in the airways of mice and in human cell culture models after microcystin aerosol exposure, and have found a consistent molecular patterns similar to those of Type 1/Type 17 driven neutrophilic asthma. Here we address the hypothesis that MC-LR will increase the inflammatory mediators of neutrophilic asthma leading to worsening symptoms. This is tested and characterized in both in vitro and in vivo models. We found that asthma symptoms and molecular signatures of inflammation are both worsened by MC-LR exposure in a mouse model of neutrophilic asthma. We found that 3D human airway cell culture models reconstructed from asthmatic donor cells are similarly affected, however healthy donor cells are nearly unaltered by comparison. Aggregating these findings with RNA sequencing data from all models, we developed a hypothetical molecular mechanism which relies on MC-LR mediated amplification of existing inflammatory signaling. We test this in a human reporter cell line of NF-{kappa}B activity and further demonstrate the mechanism by inhibitor testing. This study sheds light on the risk to asthmatic patients living near or recreating on affected bodies of water. Beyond asthma, we believe this study provides crucial insight into the findings over the last 40 years concerning disparate outcomes of MC-LR exposure as the result of exposure will be dependent on the signaling state of the tissue upon exposure.

molecular biology↗

bioRxiv2022

GeneToList: A web application to assist with gene identifiers for the non-bioinformatics-savvy scientist

The increasing incorporation of omics technology into clinical and translational medicine presents challenges to end users of the large and complex datasets that are generated by these methods. A particular challenge in genomics is that the nomenclature for genes is not uniform between large genomic databases or between commonly used genetic analysis tools. Furthermore, outdated genomic nomenclature can still be found amongst scientific communications including peer-reviewed manuscripts. Therefore, a web application (GeneToList) was developed to assist is gene ID conversion and alias matching, with a specific focus on achieving a user-friendly interface for the non-bioinformatics-savvy scientist. Availability and implementationGeneToList is available at https://www.genetolist.com/. The tool is a web application that is compatible with many standard browsers. ContactJoshua.Breidenbach@UToledo.edu or support@genetolist.com

bioinformatics↗

bioRxiv2020

Impact of Comorbidities on the Expression of SARS-CoV-2 Viral Entry-Related Genes

Viral entry mechanisms for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an important aspect of virulence. Proposed mechanisms involve host cell membrane-bound angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine proteases (TTSPs), such as transmembrane serine protease isoform 2 (TMPRSS2). The distribution of expression of these genes across cell types representing multiple organ systems in healthy individuals has been recently demonstrated. However, comorbidities such as diabetes and cardiovascular disease are highly prevalent in patients with Coronavirus Disease 2019 (COVID-19) and associated with worse outcomes. Whether these conditions contribute directly to SARS-CoV-2 virulence remain unclear. Here we show that the expression levels of ACE2, TMPRSS2 and other viral entry-related genes are modulated in target organs of select disease states. In tissues such as heart, which normally express ACE2 but minimal TMPRSS2, we found that TMPRSS2 as well as other TTSPs are elevated in individuals with comorbidities vs healthy individuals. Additionally, we found increased expression of viral entry-related genes in the settings of hypertension, cancer or smoking across target organ systems. Our results demonstrate that common comorbidities may contribute directly to SARS-CoV-2 virulence and suggest new therapeutic targets to improve outcomes in vulnerable patient populations.

microbiology↗