Highlights d Intestinal epithelium-specific Piezo1 deletion disturbs gut and bone homeostasis d Fecal ssRNA is a natural ligand of Piezo1 d Colonic infusion of RNase A suppresses gut motility and increases bone mass d Intestinal ssRNA-Piezo1 axis is a critical factor in systemic 5-HT synthesis

SummaryCandida albicans infection can cause skin, vulvar, or oral pain. Despite the obvious algesic activity of C. albicans, the molecular mechanisms of fungal nociception remain largely unknown. Here we show that the C. albicans-specific signaling pathway led to severe mechanical allodynia. We discovered that C. albicans-derived β-glucan stimulated nociceptors depending on Dectin-1, and two pathways in inflammatory pain. The major pathway operates via the Dectin-1-mediated ATP-P2X3/P2X2/3 axis through intercellular relationships between keratinocytes and primary sensory neurons, which depends on the ATP transporter vesicular nucleotide transporter (VNUT). The other pathway operates via the Dectin-1-mediated PLC-TRPV1/TRPA1 axis in primary sensory neurons. Intriguingly, C. albicans-derived β-glucan has the ability to enhance histamine-independent pruritus, and VNUT inhibitor clodronate can be used to treat unpleasant feelings induced by β-glucan. Collectively, this is the first report to indicate that Dectin-1 and VNUT mediated innate sensory mechanisms that detect fungal infection.

Zinc finger protein St18 was initially reported as candidate tumor suppressor gene, and also suggested that fibroblast St18 positively regulates NF-kB activation. Despite the pleiotropic functions of St18, little is known about its roles in macrophages. Here, we report that myeloid St18 is a potent inhibitor of VEGF-A. Mice lacking St18 in myeloid lineages exhibit increased retinal vasculature with enhanced serum VEGF-A concentrations. Despite the normal activation of NF-kB target genes, these mice are highly susceptible to LPS-induced shock, polymicrobial sepsis, and experimental colitis, accompanied by enhanced vascular and intestinal leakage. Pharmacological inhibition of VEGF signaling rescued the high mortality rate of myeloid-specific St18-deficient mice in response to inflammation. Mechanistically, St18 directly binds to Sp1 and attenuates its activity, leading to the suppression of Sp1 target gene VEGF-A. Using mouse genetic and pharmacological models, we reveal myeloid St18 as a critical septic death protector.