Biology subjects

Zebochin, I.

Publications and source records attributed to Zebochin, I..

3 recordsLinked to original sources

bioRxiv2024

A role for fibroblast and mural cell subsets in models of neuropathic pain.

Neuropathic pain is a particularly intractable type of chronic pain that can result from physical nerve damage due to surgery or entrapment. Here, we present data which suggest that a particular subclass of fibroblast and mural cells may be implicated in the sensory neuron dysfunction that is characteristic of this pain state. In a mouse model of traumatic painful neuropathy, we used cell sorting, nerve tissue clearing and RNA sequencing to study mesenchymal lineage cells. With cell sorting (n = 4 mouse nerves) and tissue clearing (n = 5), we show that fibroblasts and mural cells positive for the platelet-derived growth factor receptor beta (Pdgfrb) gene are increased in number for at least two months post-nerve damage. Moreover, single cell RNA sequencing data (n = 4) from our own lab and those of three other laboratories reveal that Pdgfrb+ cells express high levels of known and putative pro-algesic mediators. Bulk sequencing of sorted Pdgfrb+ fibroblasts (n = 10) and Pdgfrb+/Cd146+ mural cells (n = 11) further indicate that many of these mediators are upregulated in neuropathy. We go on to demonstrate that a human nerve pericyte line releases a selection of these pro-algesic mediators at protein level. Moreover, conditioned media from stimulated human pericytes induces intra-cellular changes in human induced pluripotent stem cell derived sensory neurons (n = 5 independent differentiations); these changes (phosphorylation of the transcription factor signal transducer and activator of transcription 3, STAT3) have been previously linked to sensory neuron activation. In summary, our data indicate that mesenchymal cell abnormalities should be considered when developing novel strategies to tackle neuropathic pain. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/627455v2_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@186492corg.highwire.dtl.DTLVardef@12deb90org.highwire.dtl.DTLVardef@1c43b8aorg.highwire.dtl.DTLVardef@211952_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2024

Blockade of rheumatoid arthritis synovial fluid-induced sensory neuron activation by JAK inhibitors

ObjectiveClinical studies suggest that compared to anti-TNF treatment, JAK inhibitors (JAKi) are superior in reducing pain in rheumatoid arthritis (RA). The underlying mechanisms for this observation are still unknown. Sensory neurons transmit noxious signals from inflamed joints to the central nervous system, where a pain percept is generated. We investigated whether JAKi exert direct effects on sensory neurons. MethodsIn-house and public RNA sequencing datasets of sensory neurons were analysed for relevant JAK/STAT and cytokine-receptor gene expression. Human induced pluripotent stem cell (IPSC)-derived sensory neurons were stimulated with serum and synovial fluid (SF) from individuals with RA, or with selected cytokines that were found in RA SF by Luminex. Phosphorylation of STAT3 (pSTAT3) was assessed by Western blot. Sensory neuron activation was examined by recording neuronal firing using multi-electrode array and measuring expression levels of pain-relevant genes with STAT3-binding sites. ResultsCell-free RA synovial fluid induced pSTAT3 in IPSC-derived sensory neurons, an effect which was completely blocked by the JAKi tofacitinib. Compared to paired serum, RA SF was enriched for the JAK/STAT cytokines IL-6, IL-11, LIF, IFN-alpha and IFN-beta, with their requisite receptors present on sensory neurons. Stimulation of IPSC- derived sensory neurons with these recombinant cytokines recapitulated pSTAT3 induction in these cells. Furthermore, IL-6+sIL-6R or LIF upregulated expression of pain-relevant genes which was blocked by tofacitinib. Finally, we provided evidence that LIF can induce neuronal sensitisation. ConclusionOur data indicate that JAKi can act directly on sensory neurons, providing a potential mechanistic explanation for their suggested superior analgesic properties.

immunology↗

bioRxiv2024

Modelling inflammation-induced peripheral sensitization in a dish - more complex than expected?

Peripheral sensitization of nociceptors is believed to be a key driver of chronic pain states. Here, we sought to study the effects of a modified version of inflammatory soup on the excitability of human stem-cell derived sensory neurons. For this, we used a pre-existing and a novel stem cell line, modified to stably express the calcium sensor GCamP6f. Upon treatment with inflammatory soup, we observed no changes in neuronal transcription or functional responses upon calcium imaging, and only a very minor increase in resting membrane potential via whole cell patch clamping. Similarly small changes were observed when treating mouse primary sensory neurons with inflammatory soup. A semi-systematic re-examination of past literature further indicated that observed effects of inflammatory mediators on dissociated sensory neuron cultures are generally very small. We conclude that modelling inflammation-induced peripheral sensitization in vitro is non-trivial and will require careful selection of mediators and/or more complex, longitudinal multi-cellular setups. Especially in the latter, our novel GCamP6f induced-pluripotent stem cell line may be of value.

neuroscience↗