Cutaneous neurogenic inflammation (CNI) is inflammation that is induced (or enhanced) in the skin by the release of neuropeptides from sensory nerve endings. Clinical manifestations are mainly sensory and vascular disorders such as pruritus and erythema. Transient receptor potential vanilloid 1 and ankyrin 1 (TRPV1 and TRPA1, respectively) are non-selective cation channels known to specifically participate in pain and CNI. Both TRPV1 and TRPA1 are co-expressed in a large subset of sensory nerves, where they integrate numerous noxious stimuli. It is now clear that the expression of both channels also extends far beyond the sensory nerves in the skin, occuring also in keratinocytes, mast cells, dendritic cells, and endothelial cells. In these non-neuronal cells, TRPV1 and TRPA1 also act as nociceptive sensors and potentiate the inflammatory process. This review discusses the role of TRPV1 and TRPA1 in the modulation of inflammatory genes that leads to or maintains CNI in sensory neurons and non-neuronal skin cells. In addition, this review provides a summary of current research on the intracellular sensitization pathways of both TRP channels by other endogenous inflammatory mediators that promote the self-maintenance of CNI.

Glioblastoma (GB) is a highly infiltrative tumor recurring in 90% of cases within a few centimeters of the resection cavity, even in cases of complete tumor resection and adjuvant chemo/radiotherapy. This observation highlights the importance of understanding this special zone of brain tissue surrounding the tumor. It is becoming clear that the nonneoplastic stromal compartment of most solid cancers plays an active role in tumor proliferation, invasion, and metastasis. Very little information, other than that concerning angiogenesis and immune cells, has been collected for stromal cells from GB. As part of a translational research program, we have isolated a new stromal cell population surrounding GB by computer-guided stereotaxic biopsies and primary culture. We named these cells GB-associated stromal cells (GASCs). GASCs are diploid, do not display the genomic alterations typical of GB cells, and have phenotypic and functional properties in common with the cancer-associated fibroblasts (CAFs) described in the stroma of carcinomas. In particular, GASCs express markers associated with CAFs such as fibroblast surface protein, alpha-smooth muscle actin (α-SMA), and platelet-derived growth factor receptor-beta (PDGFRβ). Furthermore, GASCs have a molecular expression profile different from that of control stromal cells derived from non-GB peripheral brain tissues. GASCs were also found to have tumor-promoting effects on glioma cells in vitro and in vivo. The isolation of GASCs in a tumor of neuroepithelial origin was unexpected, and further studies are required to determine their potential as a target for antiglioma treatment.

Due to the close interactions between the skin and peripheral nervous system, there is increasing evidence that the cutaneous innervation is an important modulator of the normal wound healing process. The communication between sensory neurons and skin cells involves a variety of molecules (neuropeptides, neurohormones, and neurotrophins) and their specific receptors expressed by both neuronal and nonneuronal skin cells. It is well established that neurotransmitters and nerve growth factors released in skin have immunoregulatory roles and can exert mitogenic actions; they could also influence the functions of the different skin cell types during the wound healing process.

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