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Ozkan, E.

Publications and source records attributed to Ozkan, E..

3 recordsLinked to original sources

A Novel Mouse Model Demonstrates In Vivo Replenishment of Central Nervous System Pericytes After Successful Acute Ablation

Central nervous system (CNS) pericytes play crucial roles in vascular development and blood-brain barrier maturation during prenatal development, as well as in regulating cerebral blood flow in adults. They have also been implicated in the pathogenesis of numerous neurological disorders. However, the behavior of pericytes in the adult brain after injury remains poorly understood, partly due to limitations in existing pericyte ablation models. To investigate pericyte responses following acute ablation, we developed a tamoxifen-inducible pericyte ablation model by crossing PDGFR{beta}-P2A-CreERT2 and Rosa26-DTA176 transgenic mouse lines. Using this model, we studied the effects of different tamoxifen doses and conducted histological examinations 15 and 60 days post-injection to assess both short- and long-term impacts of pericyte ablation. Our results demonstrate that a low dose of tamoxifen effectively ablates CNS pericytes in mice without reducing survival or causing significant systemic side effects, such as weight loss. Additionally, we found that the extent of pericyte depletion varies between the cortex and the spinal cords gray and white matter regions. Importantly, both pericyte coverage and numbers increased in the weeks following acute ablation, indicating the regenerative capacity of CNS pericytes in vivo. This model offers a valuable tool for future studies on the role of pericytes in neurological disorders, overcoming the limitations of constitutive pericyte ablation models.

neuroscience↗

A trans-synaptic IgLON adhesion molecular complex directly contacts and clusters a nicotinic receptor

The localization and clustering of neurotransmitter receptors at appropriate postsynaptic sites is a key step in the control of synaptic transmission. Here, we identify a novel paradigm for the synaptic localization of an ionotropic acetylcholine receptor (AChR) based on the direct interaction of its extracellular domain with a cell adhesion molecule of the IgLON family. Our results show that RIG-5 and ZIG-8, which encode the sole IgLONs in C. elegans, are tethered in the pre- and postsynaptic membranes, respectively, and interact in vivo through their first immunoglobulin-like (Ig) domains. In addition, ZIG-8 traps ACR-16 via a direct cis-interaction between the ZIG-8 Ig2 domain and the base of the large extracellular AChR domain. Such mechanism has never been reported, but all these molecules are conserved during evolution. Similar interactions may directly couple Ig superfamily adhesion molecules and members of the large family of Cys-loop ionotropic receptors, including AChRs, in the mammalian nervous system, and may be relevant in the context of IgLON-associated brain diseases.

neuroscience↗

Structural basis and functional roles for Toll-like receptor binding to Latrophilin adhesion-GPCR in embryo development

Latrophilins/ADGRLs are conserved adhesion-type G protein-coupled receptors associated with early embryonic morphogenesis defects, lethality, and sterility across multiple model organisms. However, their mechanistic roles in embryogenesis and the identity of their binding ligands remain unknown. Here, we identified a cell-surface receptor, TOL-1, the sole Toll-like receptor in C. elegans, as a novel ligand for the C. elegans Latrophilin, LAT-1. The extracellular lectin domain of LAT-1 directly binds to the second leucine-rich repeat domain of TOL-1. The highresolution crystal structure and the cryo-EM density map of the LAT-1-TOL-1 ectodomain complex reveal a previously-unobserved mode of one-to-one interaction enabled by a large interface. CRISPR/Cas9-mediated mutation of key interface residues selectively disrupted the endogenous LAT-1-TOL-1 interaction in C. elegans, leading to partial sterility, lethality, and malformed embryos. Thus, TOL-1 binding to LAT-1 represents a receptor-ligand axis essential for animal morphogenesis.

biochemistry↗