by Keyword: Actin dynamics

Liu, TY, De Pace, C, Huang, RD, Bruno, G, Shao, T, Tian, YP, Chen, B, Chen, L, Luo, K, Gong, QY, Ruiz-Pérez, L, Battaglia, G, Tian, XH, (2023). An Iridium (III) complex revealing cytoskeleton nanostructures under super-resolution nanoscopy and liquid-phase electron microscopy Sensors And Actuators B-Chemical 388, 133839

Live cell actin visualization is fundamental for exploring cellular motility, cytokinesis, intracellular transport, and other correlated functions. The current imaging techniques that allow imaging of actin in its native environment are optical and electron microscopy. Such imaging techniques offer high enough resolution to investigate the ultrastructure of actin however they come at the expense of actin integrity. Inspired by the lack of suitable probes that preserve actin's integrity, we designed a cyclometalated Ir (III) complex that interacts with live cells and displays light switch behaviour upon specific actin binding. The exceptional photophysical properties of the proposed probe allow unprecedented resolution of cytoskeleton ultrastructures under stimulated emission depletion (STED) super-resolution nanoscopy. Moreover, the Ir complex enables the capability of visualizing actin polymers and periodicity under correlative light electron microscopy (CLEM) and liquid-phase electron microscopy (LPEM) at similar to 8 nm resolution.

JTD Keywords: Actin dynamics, Actin targeting, Adhesion, Cells, Clem, Fluorescent, Iridium (iii) complex, Lead, Light, Lpem, Super-resolution ultrastructures

Mesquida-Veny, F, Martinez-Torres, S, Del Rio, JA, Hervera, A, (2022). Nociception-Dependent CCL21 Induces Dorsal Root Ganglia Axonal Growth via CCR7-ERK Activation Frontiers In Immunology 13, 880647

While chemokines were originally described for their ability to induce cell migration, many studies show how these proteins also take part in many other cell functions, acting as adaptable messengers in the communication between a diversity of cell types. In the nervous system, chemokines participate both in physiological and pathological processes, and while their expression is often described on glial and immune cells, growing evidence describes the expression of chemokines and their receptors in neurons, highlighting their potential in auto- and paracrine signalling. In this study we analysed the role of nociception in the neuronal chemokinome, and in turn their role in axonal growth. We found that stimulating TRPV1(+) nociceptors induces a transient increase in CCL21. Interestingly we also found that CCL21 enhances neurite growth of large diameter proprioceptors in vitro. Consistent with this, we show that proprioceptors express the CCL21 receptor CCR7, and a CCR7 neutralizing antibody dose-dependently attenuates CCL21-induced neurite outgrowth. Mechanistically, we found that CCL21 binds locally to its receptor CCR7 at the growth cone, activating the downstream MEK-ERK pathway, that in turn activates N-WASP, triggering actin filament ramification in the growth cone, resulting in increased axonal growth.

JTD Keywords: axonal growth, ccl21, ccr7, mek-erk, Actin dynamics, Axonal growth, Ccl21, Ccr7, Cell-migration, Central-nervous-system, Chemokine, Ligands, Mek-erk, Microglia, Neurons, Neuropathic pain, Nociception, Phosphorylation, Regeneration