Biology subjects

Brier, M.

Publications and source records attributed to Brier, M..

2 recordsLinked to original sources

bioRxiv2023

Alternating Magnetic Fields Drive Stimulation of Gene Expression via Generation of Reactive Oxygen Species

Magnetogenetics represents a method for remote control of cellular function. Despite successful use of magnetic fields to control gene expression in vitro and in vivo, the mechanism underlying magnetogenetics is largely unknown, thereby hindering further development and applications. Previous work suggests a chemical-based mechanism involving the generation of reactive oxygen species (ROS) as a platform initiator and downstream signaling molecule. Herein, a chemical biology approach was used to elucidate further the mechanism of radio frequency-alternating magnetic field (RF-AMF) stimulation of a TRPV1-ferritin magnetogenetics platform that leads to Ca2+ gating. RF-AMF stimulation of HEK 293T cells expressing TRPV1-Ferritin resulted in a [~]30% and [~]140% increase in intra- and extracellular ROS levels, respectively. Mutations to specific cysteine residues in TRPV1 responsible for ROS sensitivity eliminated RF-AMF driven Ca2+-dependent transcription of secreted embryonic alkaline phosphatase (SEAP). Using a non-tethered (to TRPV1) ferritin also eliminated RF-AMF driven SEAP production. These results suggest ferritin-dependent ROS activation of TRPV1 plays a key role in the initiation of magnetogenetics. Furthermore, inhibition of IP3R-based endoplasmic reticulum (ER) Ca2+ release with Xestospongin C, inhibition of protein kinase C (PKC) activity with Go 6983, or inhibition of NADPH oxidase (NOX) isoforms 1/2 gp91phoxcytochrome with GSK 2795039 eliminated short-term RF-AMF potentiation of SEAP production with capsaicin. Similarly, Go 6983 significantly reduced long-term RF-AMF capsaicin potentiation of SEAP production. These results suggest that ROS-activated TRPV1 signaling to increase intracellular Ca2+ includes pathways involving PKC, NOX, and the ER. Together, these findings fill in current knowledge gaps in the mechanism of magnetogenetics, which may lead to translational applications in medicine and biotechnology.

bioengineering↗

bioRxiv2021

Differential sphingosine-1-phosphate receptor-1 (S1PR1) protein expressions in the dorsolateral prefrontal cortex between schizophrenia Type 1 and Type 2

Understanding the etiology and treatment approaches in schizophrenia is challenged in part by the heterogeneity of this disorder. One encouraging progress is the growing evidence that there are subtypes of schizophrenia that may relate to disease duration and premorbid severity. Recent in vitro findings of messenger ribonucleic acid (mRNA) gene expression on postmortem dorsolateral prefrontal cortex (DLPFC) showed that schizophrenia has two subtypes, those with a relatively normal DLPFC transcriptome (Type 1) and those with differentially expressed genes (Type 2). Sphingosine-1-phosphate receptor-1 (S1PR1) is one of the genes that was highly upregulated in Type 2 compared to Type 1 and controls. The impact of that finding is limited because it only can be confirmed through analysis of autopsy tissue, and the clinical characteristics such as symptoms severity or illness duration was not available from that Medical Examiner based autopsy study. However, S1PR1 has great potential because it is a target gene that can be accessed via positron emission tomography (PET) in vivo using specific radioligands (starting with [11C]CS1P1) successfully developed at our center in human brain imaging. As a preliminary study to validate this PET target in schizophrenia, S1PR1 protein expression was assessed by receptor autoradiography (ARG) using [3H]CS1P1 and immunohistochemistry (IHC) in the DLPFC from patients with schizophrenia classified as Type 1 or Type 2 based on their DLPFC transcriptomes and from controls. Our analyses demonstrate that ARG S1PR1 protein expression is significantly higher in Type 2 compared to Type 1 (p < 0.05) and controls (p < 0.05), which was consistent with previous mRNA S1PR1. These findings support the possibility that PET S1PR1 can be used as a future imaging biomarker to distinguish these subgroups of schizophrenic patients during life with obvious implications for both patient management and the design of clinical trials to validate novel pharmacologic therapies.

neuroscience↗