Pain is a complex process that involves both detection in the peripheral nervous system and perception in the CNS. Individual-toindividual differences in pain are well documented, but not well understood. Here we capitalized on inherited erythromelalgia (IEM), a well characterized human genetic model of chronic pain, and studied a unique family containing related IEM subjects with the same disease-causing Na V 1.7 mutation, which is known to make dorsal root ganglion (DRG) neurons hyperexcitable, but different pain profiles (affected son with severe pain, affected mother with moderate pain, and an unaffected father). We show, first, that, at least in some cases, relative sensitivity to pain can be modeled in subject-specific induced pluripotent stem cell (iPSC)-derived sensory neurons in vitro; second, that, in some cases, mechanisms operating in peripheral sensory neurons contribute to interindividual differences in pain; and third, using whole exome sequencing (WES) and dynamic clamp, we show that it is possible to pinpoint a specific variant of another gene, KCNQ in this particular kindred, that modulates the excitability of iPSC-derived sensory neurons in this family. While different gene variants may modulate DRG neuron excitability and thereby contribute to interindividual differences in pain in other families, this study shows that subject-specific iPSCs can be used to model interindividual differences in pain. We further provide proof-of-principle that iPSCs, WES, and dynamic clamp can be used to investigate peripheral mechanisms and pinpoint specific gene variants that modulate pain signaling and contribute to interindividual differences in pain.

microRNA-21 (miR-21) is the most commonly upregulated miRNA in solid tumors. This cancer-associated microRNA (oncomiR) regulates various downstream effectors associated with tumor pathogenesis during all stages of carcinogenesis. In this study, we analyzed the function of miR-21 in noncancer cells of the tumor microenvironment to further evaluate its contribution to tumor progression. We report that the expression of miR-21 in cells of the tumor immune infiltrate, and in particular in macrophages, was responsible for promoting tumor growth. Absence of miR-21 expression in tumor- associated macrophages (TAMs), caused a global rewiring of their transcriptional regulatory network that was skewed toward a proinflammatory angiostatic phenotype. This promoted an antitumoral immune response characterized by a macrophage-mediated improvement of cytotoxic T-cell responses through the induction of cytokines and chemokines, including IL-12 and C-X-C motif chemokine 10. These effects translated to a reduction in tumor neovascularization and an induction of tumor cell death that led to decreased tumor growth. Additionally, using the carrier peptide pH (low) insertion peptide, we were able to target miR-21 in TAMs, which decreased tumor growth even under conditions where miR-21 expression was deficient in cancer cells. Consequently, miR-21 inhibition in TAMs induced an angiostatic and immunostimulatory activation with potential therapeutic implications.

Cisplatin is an effective chemotherapeutic agent, but significant nephrotoxicity limits its clinical use. Despite extensive investigation of the acute cellular and molecular responses to cisplatin, the mechanisms of progression from acute to chronic kidney injury have not been explored. We used functional and morphological metrics to establish a time-point when the transition from acute and reversible kidney injury to chronic and irreparable kidney disease is clearly established. In mice administered 1 or 2 doses of intraperitoneal cisplatin separated by 2 weeks, kidney function returned toward baseline two weeks after the first dose, but failed to return to normal two weeks following a second dose. Multiphoton microscopy revealed increased glomerular epithelial and proximal tubular damage in kidneys exposed to two doses of cisplatin compared with those exposed to a single dose. In contrast, there was no evidence of fibrosis, macrophage invasion, or decrease in endothelial cell mass in chronically diseased kidneys. Pathway analysis of microarray data revealed regulated necrosis as a key determinant in the development of chronic kidney disease after cisplatin administration. Western blot analysis demonstrated activation of proteins involved in necroptosis and increased expression of kidney injury markers, cellular stress response regulators, and upstream activators of regulated necrosis, including Toll-like receptors 2 and 4. These data