Biology subjects

Christenson, P. R.

Publications and source records attributed to Christenson, P. R..

3 recordsLinked to original sources

bioRxiv2023

Blood-based Nano-QuIC: Accelerated and Inhibitor-resistant Detection of Misfolded Alpha-synuclein

A hallmark of -synucleinopathies (e.g. Parkinsons disease) is the misfolding and aggregation of -synuclein in tissues and biological fluids. Protein amplification assays like real-time quaking-induced conversion (RT-QuIC) are sensitive yet currently limited to semi-invasive sample types such as cerebrospinal fluid because more accessible samples, such as blood, contain inhibitors. Here, we show that Nanoparticle-enhanced Quaking-induced Conversion (Nano-QuIC) can double the speed of reactions spiked with misfolded -synuclein while increasing sensitivity 100-fold in human plasma. Nano-QuIC detected spike concentrations down to 90 pg/ml in lysed whole blood, while reactions without nanoparticles (RT-QuIC) failed to have any detection due to the presence of strong inhibitors. Moreover, Nano-QuIC showed increased seeding activity in plasma samples from Parkinsons patients (n=4) versus healthy controls (n=4). This sets the groundwork for the noninvasive diagnostic use of Nano-QuIC, potentially enabling early disease detection and management through blood-based testing. TOC graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/552630v2_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@1141573org.highwire.dtl.DTLVardef@18c63d6org.highwire.dtl.DTLVardef@1ee9524org.highwire.dtl.DTLVardef@81af13_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2023

Microfluidic Quaking-Induced Conversion (Micro-QuIC) for Rapid On-Site Amplification and Detection of Misfolded Proteins

Protein misfolding diseases, such as prion diseases, Alzheimers, and Parkinsons, share a common molecular mechanism involving the misfolding and aggregation of specific proteins. There is an urgent need for point-of-care (POC) diagnostic technologies that can accurately detect these misfolded proteins, facilitating early diagnosis and intervention. Here, we introduce the Microfluidic Quaking Induced Conversion (Micro-QuIC), a novel acoustofluidic platform for the rapid and sensitive detection of protein misfolding diseases. We demonstrate the utility of our technology using chronic wasting disease (CWD) as a model system, as samples from wild white-tailed deer are readily accessible, and CWD shares similarities with human protein misfolding diseases. Acoustofluidic mixing enables homogeneous mixing of reagents in a high-Reynolds-number regime, significantly accelerating the turnaround time for CWD diagnosis. Our Micro-QuIC assay amplifies prions by an order of magnitude faster than the current gold standard, real-time quaking-induced conversion (RT-QuIC). Furthermore, we integrated Micro-QuIC with a gold nanoparticle-based, naked-eye detection method, which enables visual discrimination between CWD positive and negative samples without the need for a bulky fluorescence detection module. This integration creates a rapid, POC testing platform capable of detecting misfolded proteins associated with a variety of protein misfolding diseases. TOC graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/549283v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@885eeaorg.highwire.dtl.DTLVardef@10f820eorg.highwire.dtl.DTLVardef@12396eaorg.highwire.dtl.DTLVardef@188fe0f_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2021

A Field-Deployable Diagnostic Assay for the Visual Detection of Misfolded Prions

Chronic Wasting Disease (CWD), a prion disease of cervids, has been identified across North America, Northern Europe and Korea. Diagnostic tools for the rapid and reliable detection of prion diseases are limited. Here, we combine gold nanoparticles (AuNPs) and quaking induced conversion (QuIC) technologies for the visual detection of amplified misfolded prion proteins from tissues of wild white-tailed deer infected with Chronic Wasting Disease (CWD). Our newly developed diagnostic test, MN-QuIC, enables both naked-eye and light-absorbance measurements for the detection of misfolded prions. The MN-QuIC assay leverages basic laboratory equipment that is cost-effective and portable, thus facilitating real-time prion diagnostics across a variety of settings. To test the portability of our assay, we deployed to a rural field station in southeastern Minnesota and tested for CWD on site. We successfully demonstrated that MN-QuIC is functional in a non-traditional laboratory setting by performing a blinded analysis in the field and correctly identifying all CWD positive and CWD not detected (independently confirmed with ELISA and/or IHC tests) animals at the field site, thus documenting the portability of the assay. Additionally, we show that electrostatic forces and concentration effects help govern the AuNP/prion interactions and contribute to the differentiation of CWD-prion positive and negative samples. We examined 17 CWD-positive and 24 CWD-not-detected white-tailed deer tissues that were independently tested using ELISA, IHC, and RT-QuIC technologies, and results secured with MN-QuIC were 100% consistent with these tests. We conclude that hybrid AuNP and QuIC assays, such as MN-QuIC, have great potential for sensitive, field-deployable diagnostics for a variety of protein misfolding diseases.

molecular biology↗