Biology subjects

Bolding, M.

Publications and source records attributed to Bolding, M..

6 recordsLinked to original sources

bioRxiv2026

Targeting the RNA regulator HuR in acute traumatic brain injury mitigates secondary injury and improves functional outcome by suppressing neuroinflammation

Traumatic brain injury (TBI) affects ~2.5 million people annually in the US. Minutes after TBI, microglia and astrocytes initiate a neuroinflammatory cascade which promotes secondary injury via cytotoxicity, blood-brain barrier damage, edema, and immune cell recruitment. HuR, an RNA regulator, plays a critical role in the glial response by promoting the expression of proinflammatory mediators including IL-6, IL-1{beta}, TNF-, COX-2, CCL2, and CXCL1 via adenine and uridine-rich elements in the 3' untranslated region of their mRNAs. Here, we assessed SRI-42127, a small molecule HuR inhibitor developed by our group, on neuroinflammatory responses, secondary injury, and functional outcome after TBI. Male mice underwent controlled cortical impact (CCI) followed by peripheral administration of SRI-42127. Functional outcomes assessed included: motor function (balance beam/rotarod) and memory function (object location/recognition). Edema, lesion volume, and BBB permeability were assessed by MRI, brain water content, and Evans blue dye extravasation. HuR nucleocytoplasmic translocation, neuronal loss/apoptosis, microglial and astrocyte activation, and neutrophil infiltration were quantified by immunohistochemistry. Proinflammatory mediator induction was assessed by RT-qPCR and/or immunoblot. Results showed that SRI-42127 treatment improved spatial memory and fine motor performance in the first week in parallel with a reduction in edema, vascular permeability, lesion size, and neuronal loss/apoptosis. There was attenuated microglial activation and astrogliosis, decreased neutrophil infiltration, and suppression of proinflammatory mediator induction. Mechanistically, SRI-42127 inhibited HuR nucleocytoplasmic translocation in microglia and astrocytes. In summary, SRI-42127 potently suppresses neuroinflammation and secondary injury after TBI, improves functional outcomes, and identifies HuR as a new therapeutic target in TBI.

neuroscience↗

bioRxiv2025

Sulfotransferase 4A1 (SULT4a1): A Novel Neuroprotective Protein in Stroke

SULT4a1, a member of the cytosolic sulfotransferase family, is predominantly expressed in neurons and plays potentially vital roles in regulating neural survival and function. SULT4a1 protects against mitochondrial dysfunction and oxidative stress. SULT4a1 levels decrease in experimental stroke models and may play a critical neuroprotective role in mitigating neuronal injury caused by oxygen-glucose deprivation (OGD) and ischemic stroke, as shown in a transient middle cerebral artery occlusion (tMCAO) mouse model. In this study, we investigated the neuroprotective role of SULT4a1 in OGD and tMCAO and highlighted its expression pattern and involvement in maintaining mitochondrial function and reducing oxidative stress, two early pathophysiological features in stroke and related neuronal injury. Our data show that decreased SULT4a1 expression in OGD conditions and in the tMCAO mouse brain leads to enhanced neuronal damage, emphasizing the importance of SULT4a1 in preserving neuronal integrity. Loss of SULT4a1 alone was sufficient to decrease mitochondrial function in mouse cortical neurons. Notably, overexpression of SULT4a1 preserved mitochondrial function, reduced the loss of mitochondrial membrane potential, and diminished oxidative stress, as evidenced by lower reactive oxygen species (ROS) production and reduced protein carbonylation. These results indicate that modulating SULT4a1 expression in stroke could offer a promising strategy for preventing neuronal damage. Indeed, overexpression of SULT4a1 via stereotaxic injection of AAV9 into the mouse brain mitigated tMCAO-related brain injury and functional deficits over time. The findings of this study indicate that SULT4a1 may protect neurons in stroke and related brain injury, possibly by maintaining mitochondrial function and redox homeostasis through mechanisms that are still unknown. It is likely that SULT4a1 regulates neuroprotective processes in both the mitochondria and the cytosol. However, further research is needed to clarify the specific molecular pathways involved in its neuroprotective function.

neuroscience↗

bioRxiv2023

Ectopically Expressed Rhodopsin Is Not Sensitive to X-rays

Visual perception of X-radiation is a well-documented, but poorly understood phenomenon. Early literature implicates scotopic rod cells and rod opsin in X-ray detection, however, evidence suggests that X-rays excite the retina via a different mechanism than visible light. While rhodopsins role in X-ray perception is unclear, the possibility that it could function as an X-ray receptor has led to speculation that it could act as a transgenically expressed X-ray receptor. If so, it could be used to transduce transcranial X-ray signals and control the activity of genetically targeted populations of neurons in a less invasive version of optogenetics, X-genetics. Here we investigate whether human rhodopsin (hRho) is capable of transducing X-ray signals when expressed outside of the retinal environment. We use a live-cell cAMP GloSensor luminescence assay to measure cAMP decreases in hRho-expressing HEK293 cells in response to visible light and X-ray stimulation. We show that cAMP GloSensor luminescence decreases are not observed in hRho-expressing HEK293 cells in response to X-ray stimulation, despite the presence of robust responses to visible light. Additionally, irradiation had no significant effect on cAMP GloSensor responses to subsequent visible light stimulation. These results indicate that ectopically expressed rhodopsin does not function as an X-ray receptor, and suggest that it is not capable of transducing transcranial X-ray signals into neural activity for X-ray mediated, genetically targeted neuromodulation.

neuroscience↗

bioRxiv2020

Somatotopic Arrangement of Eight Distinct Skin Areas in the Human Primary Somatosensory Cortex Derived from Functional Magnetic Resonance Imaging

AO_SCPLOWBSTRACTC_SCPLOWBlood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) was used to investigate cortical activity associated with peripheral tactile stimuli in a small cohort of healthy humans. MR-safe automated pneumatic stimulators modeled after the Wartenberg pinwheel were used to generate tactile stimuli at regular intervals on eight disparate areas of skin. The phase-encoded BOLD responses of voxels in the cerebral cortex were characterized by the maximal normalized cross-correlation coefficients at time delays between an idealized response and the measure time course. Overall at the group level, the somatotopic organization of the somatosensory cortex (SI) follows the accepted homunculus model, but a noticeable amount of variation was observed between individual study participants. The surface areas of cortical regions in SI activated by tactile stimulation of different body parts were calculated, giving an estimate of cortical magnification factors. Data collected with the participant actively attending the stimuli were compared to data collected before the attention task. No significant attention-related changes were observed in the somatotopic maps or in time courses of voxels well-correlated to stimuli.

neuroscience↗

bioRxiv2019

LITE-1 Mediates X-ray Avoidance Response in C. elegans

We report the finding that C. elegans display X-ray avoidance behavior at high but well tolerated doses, and that this behavior appears to require LITE-1, a gustatory receptor that has been implicated in UV avoidance behavior. We recorded acute behavioral responses of wildtype worms to increasing intensities of X-ray stimulation and found a positive stimulation-response relationship. Mutant strains of worms with dysfunctional photoreceptor proteins LITE-1 and GUR-3 were assayed, and the X-ray avoidance response was found to be nearly absent in LITE-1 mutants but not GUR-3 mutants, suggesting a prominent role for LITE-1 in the detection of X-rays. These findings may be important for developing optogenetics tools to stimulate cells in deep tissue using X-rays, for understanding the mechanism of LITE-1 signaling, and for understanding how organisms may respond to radiation.

neuroscience↗

bioRxiv2019

Localized delivery and uncaging of glutamate from MRI-visible albumin nanoclusters in the rat hippocampus using focused ultrasound

There is an ongoing need for noninvasive tools to manipulate brain activity with molecular, spatial and temporal specificity. Here we have investigated the use of MRI-visible, albumin-based nanoclusters for noninvasive, localized and temporally specific drug delivery to the rat brain. We demonstrated that IV injected nanoclusters could be deposited into target brain regions via focused ultrasound facilitated blood brain barrier opening. We showed that nanocluster location could be confirmed in vivo with MRI. Additionally, following confirmation of nanocluster delivery, release of the nanocluster payload into brain tissue can be triggered by a second focused ultrasound treatment performed without circulating microbubbles. Release of glutamate from nanoclusters in vivo caused enhanced c-Fos expression, indicating that the loading capacity of the nanoclusters is sufficient to induce neuronal activation. This novel technique for noninvasive stereotactic drug delivery to the brain with temporal specificity could provide a new way to study brain circuits in vivo preclinically with high relevance for clinical translation. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=36 SRC="FIGDIR/small/696237v4_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@b528f9org.highwire.dtl.DTLVardef@1950228org.highwire.dtl.DTLVardef@1c0ada0org.highwire.dtl.DTLVardef@c71790_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗