Biology subjects

Dalla Costa, I.

Publications and source records attributed to Dalla Costa, I..

4 recordsLinked to original sources

bioRxiv2026

Mouse Neural Organoids Model the Mature In Vivo Synaptic Proteome

Neural organoids represent a promising approach for modelling neural circuits and neurological disease, yet their utility depends on whether they can recapitulate the molecular complexity of mature brain synapses. Here, we optimized a protocol to generate mature forebrain organoids from mouse embryonic stem cells and used time-resolved proteomics to define the emergence of synaptic proteins during maturation. Using fluorescence-activated synaptosome sorting coupled with mass spectrometry, we quantified the synapse-enriched proteome and found a high correlation with matched in vivo synaptic proteomes. These findings demonstrate that complex mature synaptic molecular architecture is present within an in vitro organoid environment.

neuroscience↗

bioRxiv2025

Acetylation of Axonal G3BP1 through ELP3 Accelerates Axon Regeneration

Nerve injury triggers localized translation of axonal mRNAs to respond to injury and nerve regeneration. The core stress granule protein G3BP1 sequesters axonal mRNAs in granules before and after axotomy. G3BP1 granule disassembly can be regulated by post-translational modifications, including phosphorylation of S149 phosphorylation and acetylation of human K376 (mouse K374). Axonal G3BP1 undergoes phosphorylation after axotomy, but acetylation of G3BP1 in axons was unknown. Here we show that rodent G3BP1 undergoes K374 acetylation after axotomy is ELP3-dependent, which enhances axonal protein synthesis, accelerates nerve regeneration, and supports functional recovery. ELP3-depleted neurons exhibit reduced axon growth and increased axonal G3BP1 granules. The proximal axons degenerate rapidly despite maintaining soma connectivity, an effect prevented by expression of acetylmimetic G3BP1.Together, these findings identify G3BP1 acetylation via ELP3 as a critical regulator of both axonal regeneration and neuronal resilience, revealing a post-translational mechanism that links stress granule regulation to neuronal repair and protection.

neuroscience↗

bioRxiv2025

An axon-intrinsic loop restricts nerve regeneration through axonal protein synthesis

Injured axons synthesize the RNA Binding Protein KHSRP that promotes mRNA decay and slows nerve regeneration. Axotomy-induced increase in axoplasmic Ca2+ activates axonal Khsrp translation, and while Ca2+ returns to pre-injury levels within 16 hours post-axotomy, axonal KHSRP remains elevated. Alternating translation of Reg3a and Khsrp sustains axonal KHSRP levels in regenerating axons. Nerve injury activates Reg3a expression, resulting in increased REG3A synthesis and secretion from axons. REG3A stimulates ER Ca2+ release to activate PERK, increase eIF2 phosphorylation, and increase Khsrp translation. Axoplasmic Ca2+ slowly oscillates in growth cones and Reg3A depletion attenuates growth cone Ca2+ oscillations, decreases KHSRP synthesis, reduces the axons retractive events, and accelerates peripheral nerve regeneration. Thus, REG3A to KHSRP signaling provides an axon-intrinsic loop that decelerates axon growth through localized mRNA translation.

neuroscience↗

bioRxiv2018

Precursor miRNAs are trafficked along axons associated with vesicles and locally processed to regulate growth cone steering

Various species of non-coding RNAs (ncRNAs) are enriched in subcellular compartments but the mechanisms orchestrating their delocalization and their local functions remain largely unknown. We investigated both aspects using the elongating retinal ganglion cell axon and its tip, the growth cone, as models. We reveal that specific endogenous precursor microRNAs (pre-miRNAs) are actively trafficked, anchored to CD63-positive vesicles, to distal axons along microtubules. Upon exposure to the chemotropic cue Sema3A, pre-miRNAs are processed specifically within axons into newly synthesized mature miRNAs, which, in turn, silence the basal translation of TUBB3 but not of APP. At the organismal level, these mature miRNAs are required for growth cone steering and a fully functional visual system. Overall, our results uncover a novel mode of ncRNA transport from one cytosolic compartment to another within polarized cells. They also reveal that newly synthesized miRNAs are critical components of a ncRNA-based signaling pathway that transduces environmental signals into the structural remodelling of subcellular compartments.\n\nHighlightsO_LIPrecursor miRNAs are actively transported along axons to the growth cone tethered to CD63-positive vesicles\nC_LIO_LISema3A but not Slit2 induces the local biogenesis of specific miRNAs within axons\nC_LIO_LIMature miRNAs are important for growth cone responsiveness ex vivo and the establishment of functional connections in vivo\nC_LIO_LINewly synthesized miRNAs inhibit the basal translation of TUBB3 but not APP upon Sema3A exposure\nC_LI

cell biology↗