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Gardiner, A. S.

Publications and source records attributed to Gardiner, A. S..

3 recordsLinked to original sources

Prenatal Alcohol Exposure Downregulates Focal Adhesion Molecules Tensin 1 and Tensin 2 Contributing to Cerebrovascular Dysfunction

Fetal alcohol spectrum disorders (FASD) are caused by prenatal alcohol exposure (PAE), which leads to developmental defects during embryogenesis. Angiogenesis is one facet of development that is heavily dysregulated during PAE and where such impairment is poorly understood. Here we found that expression levels of focal adhesion molecules Tensin 1 (Tns1) and Tensin 2 (Tns2) were significantly reduced by alcohol exposure in brain microvascular endothelial cells (BMVECs). We also found that miR-150-5p, which we previously found was increased by PAE, regulates the expression of Tns1 and Tns2. Dual-luciferase assays demonstrated direct binding of miR-150-5p to the 3UTRs of Tns1 and Tns2. Additionally, we utilized sprouting angiogenesis bead assays to evaluate endothelial cell sprouting in response to ethanol (EtOH) treatment and following Tns1 and/or Tns2 overexpression as well as miR-150-5p modulation. Tns1 and Tns2 rescued both EtOH- and miR-150-5p-mediated deficits in sprouting angiogenesis. Overall, we found that miR-150-5p negatively regulates Tns1 and Tns2 in BMVECs and that augmenting Tns1 and Tns2 expression may reverse the negative effects of EtOH, and subsequent miR-150-5p elevation, thus improving endothelial cell sprouting during cerebrovascular development.

cell biology↗

Spatial profiling and neurovascular communication in the developing and adolescent cortex following prenatal alcohol exposure

Fetal alcohol spectrum disorders (FASD) constitute a wide range of developmental, cognitive, and behavioral impairments caused by prenatal alcohol exposure (PAE). Although neuronal and vascular consequences of PAE have been studied, how alcohol affects the cerebrovasculature within the framework of the neurovascular unit (NVU) across development remains poorly understood. At minimum, the NVU comprises neurons, astrocyte endfeet, and endothelial cells (ECs), which coordinate to maintain brain homeostasis. Here, we used the NanoString Digital Spatial Profiling platform to characterize spatial transcriptomic data from neurons, astrocytes, and ECs from PAE and saccharin (SAC) control cortices at embryonic day 18 (E18) and postnatal day 28 (P28). Differentially expressed genes were then used for Ingenuity Pathway Analysis (IPA) to identify altered biological pathways and perform comparison analyses across developmental time points, while CellChat was used to infer cell cell communication networks. We uncovered thousands of differentially expressed genes and numerous altered pathways and biological processes in PAE cortices across development. Both IPA and CellChat analyses implicated dysregulation of vascular and extracellular matrix (ECM) remodeling, cell adhesion, and neuroinflammatory signaling. CellChat further predicted the loss of several key bidirectional relationships and altered ligand-receptor interactions among neurovascular cell types at E18 and P28. Overall, these findings identify PAE associated alterations in neurovascular gene expression and intercellular signaling across development, providing potential mechanisms by which PAE may disrupt neurodevelopment.

molecular biology↗

Loss of KHSRP Increases Neuronal Growth and Synaptic Transmission and Alters Memory Consolidation Through RNA Stabilization

The KH-type splicing regulatory protein (KHSRP) is an RNA-binding protein linked to decay of AU-rich element containing mRNAs. We have previously shown that KHSRP destabilizes the mRNA encoding the growth-associated protein GAP-43 and decreases neurite growth in cultured embryonic neurons. In contrast, loss of KHSRP stabilizes Gap43 mRNA and increases neurite growth. Here, we have tested functions of neural KHSRP in vivo. We find upregulation of 1460 mRNAs in the neocortex of adult Khsrp-/- mice, of which 527 bind to KHSRP with high specificity. These KHSRP targets are involved in pathways for neuronal morphology, axon guidance, neurotransmission and long-term memory. Neocortical neurons show increased axon growth and dendritic spine density in Khsrp-/- mice. Analyses of neuronal cultures from embryonic Khsrp-/- mice point to a neuron-intrinsic alteration in axonal and dendritic growth and elevations in KHSRP-target mRNAs, including subcellularly localized mRNAs. Hippocampus and infralimbic cortex of Khsrp-/- mice show presynaptic elevations in neurotransmission. The Khsrp-/- mice have significant deficits in both trace conditioning and attention set-shifting tasks compared Khsrp+/+ mice, indicating impaired prefrontal- and hippocampal-dependent memory consolidation with loss of KHSRP. Overall, our results indicate that prenatal deletion of KHSRP impairs neuronal development resulting in alterations in neuronal morphology and function by changing post-transcriptional control of neuronal gene expression.

neuroscience↗