Host IPR channels are dispensable for rotavirus Ca signaling but critical for intercellular Ca waves that prime uninfected cells for rapid virus spread.

Many viruses exploit host Ca signaling to facilitate their replication; however, little is known about how Ca signals from different host and viral channels contribute to the overall dysregulation of Ca signaling or promote virus replication. Using cells lacking IPR, a host ER Ca channel, we delineated intracellular Ca signals within virus-infected cells and intercellular Ca waves (ICWs), which increased Ca signaling in neighboring, uninfected cells. In infected cells, IPR was dispensable for rotavirus-induced Ca signaling and replication, suggesting the rotavirus NSP4 viroporin supplies these signals.

Distribution of P2Y and P2X purinergic receptor expression within the intestine.

Nucleotides are potent extracellular signaling molecules during homeostasis, infection, and injury due to their ability to activate purinergic receptors. The nucleotide ATP activates P2X receptors (P2RXs), whereas the nucleotides ADP, ATP, UTP, and UDP-glucose selectively activate different P2Y receptors (P2RYs). Several studies have established crucial roles for P2 receptors during intestinal inflammatory and infectious diseases, yet the most extensive characterization of purinergic signaling has focused on immune cells and the central and enteric nervous systems.

The Inositol Trisphosphate Receptor (IP R) is Dispensable for Rotavirus-induced Ca Signaling and Replication but Critical for Paracrine Ca Signals that Prime Uninfected Cells for Rapid Virus Spread.

Unlabelled: Rotavirus is a leading cause of viral gastroenteritis. A hallmark of rotavirus infection is an increase in cytosolic Ca caused by the nonstructural protein 4 (NSP4). NSP4 is a viral ion channel that releases Ca from the endoplasmic reticulum (ER) and the increase in Ca signaling is critical for rotavirus replication.

Comparison of Aptamer Signaling Mechanisms Reveals Disparities in Sensor Response and Strategies to Eliminate False Signals.

Aptamers are nucleic acid-based affinity reagents that have been incorporated into a variety of molecular sensor formats. However, many aptamer sensors exhibit insufficient sensitivity and specificity for real-world applications, and although considerable effort has been dedicated to improving sensitivity, sensor specificity has remained largely neglected and understudied. In this work, we have developed a series of sensors using aptamers for the small-molecule drugs flunixin, fentanyl, and furanyl fentanyl and compare their performance─in particular, focusing on their specificity.

Suite of Aptamer-Based Sensors for the Detection of Fentanyl and Its Analogues.

Fentanyl and its analogues are potent synthetic opioids that are commonly abused and are currently the number one cause of drug overdose death in the United States. The ability to detect fentanyl with simple, rapid, and low-cost tools is crucial for forensics, medical care, and public safety. Conventional on-site testing options for fentanyl detection─including chemical spot tests, lateral-flow immunoassays, and portable Raman spectrometers─each have their own unique flaws that limit their analytical utility.

A Human Oral Fluid Assay for - and Isomer Detection of Amphetamine and Methamphetamine Using Liquid-Liquid Extraction.

Medical providers are increasingly confronted with clinical decision-making that involves (meth)amphetamines. And clinical laboratories need a sensitive, efficient assay for routine assessment of - and -isomers to determine the probable source of these potentially illicit analytes. This paper presents a validated method of - and -isomer detection in human oral fluid from an extract used for determination of a large oral fluid assay (63 analytes) on an older AB SCIEX 4000 instrument.

Gastrointestinal organoids in the study of viral infections.

Viruses are among the most prevalent enteric pathogens. Although virologists historically relied on cell lines and animal models, human intestinal organoids (HIOs) continue to grow in popularity. HIOs are nontransformed, stem cell-derived, ex vivo cell cultures that maintain the cell type diversity of the intestinal epithelium.

Rotavirus induces intercellular calcium waves through ADP signaling.

Rotavirus causes severe diarrheal disease in children by broadly dysregulating intestinal homeostasis. However, the underlying mechanism(s) of rotavirus-induced dysregulation remains unclear. We found that rotavirus-infected cells produce paracrine signals that manifested as intercellular calcium waves (ICWs), observed in cell lines and human intestinal enteroids.

Rotavirus infection induces glycan availability to promote ileum-specific changes in the microbiome aiding rotavirus virulence.

Multiple studies have identified changes within the gut microbiome in response to diarrheal-inducing bacterial pathogens. However, examination of the microbiome in response to viral pathogens remains understudied. Compounding this, many studies use fecal samples to assess microbiome composition; which may not accurately mirror changes within the small intestine, the primary site for most enteric virus infections.

Recovirus NS1-2 Has Viroporin Activity That Induces Aberrant Cellular Calcium Signaling To Facilitate Virus Replication.

Enteric viruses in the family cause acute gastroenteritis in humans and animals, but the cellular processes needed for virus replication and disease remain unknown. A common strategy among enteric viruses, including rotaviruses and enteroviruses, is to encode a viral ion channel (i.e.

Rotavirus Calcium Dysregulation Manifests as Dynamic Calcium Signaling in the Cytoplasm and Endoplasmic Reticulum.

Like many viruses, rotavirus (RV) dysregulates calcium homeostasis by elevating cytosolic calcium ([Ca]cyt) and decreasing endoplasmic reticulum (ER) stores. While an overall, monophasic increase in [Ca]cyt during RV infection has been shown, the nature of the RV-induced aberrant calcium signals and how they manifest over time at the single-cell level have not been characterized. Thus, we generated cell lines and human intestinal enteroids (HIEs) stably expressing cytosolic and/or ER-targeted genetically-encoded calcium indicators to characterize calcium signaling throughout RV infection by time-lapse imaging.

The Rotavirus NSP4 Viroporin Domain is a Calcium-conducting Ion Channel.

Viroporins are small virus-encoded ion channel proteins. Most viroporins are monovalent selective cation channels, with few showing the ability to conduct divalent cations, like calcium (Ca). Nevertheless, some viroporins are known to disrupt host cell Ca homeostasis, which is critical for virus replication and pathogenesis.