Dental pulp stem cells as a therapy for congenital entero-neuropathy.

Hirschsprung's disease is a congenital entero-neuropathy that causes chronic constipation and intestinal obstruction. New treatments for entero-neuropathy are needed because current surgical strategies have limitations5. Entero-neuropathy results from enteric nervous system dysfunction due to incomplete colonization of the distal intestine by neural crest-derived cells. Impaired cooperation between the enteric nervous system and intestinal pacemaker cells may also contribute to entero-neuropathy. Stem cell therapy to repair these multiple defects represents a novel treatment approach. Dental pulp stem cells derived from deciduous teeth (dDPSCs) are multipotent cranial neural crest-derived cells, but it remains unknown whether dDPSCs have potential as a new therapy for entero-neuropathy. Here we show that intravenous transplantation of dDPSCs into the Japanese Fancy-1 mouse, an established model of hypoganglionosis and entero-neuropathy, improves large intestinal structure and function and prolongs survival. Intravenously injected dDPSCs migrate to affected regions of the intestine through interactions between stromal cell-derived factor-1α and C-X-C chemokine receptor type-4. Transplanted dDPSCs differentiate into both pacemaker cells and enteric neurons in the proximal colon to improve electrical and peristaltic activity, in addition to their paracrine effects. Our findings indicate that transplanted dDPSCs can differentiate into different cell types to correct entero-neuropathy-associated defects.

Inhibition of Alk signaling promotes the induction of human salivary-gland-derived organoids.

Hyposalivation and xerostomia are the cause of several morbidities, such as dental caries, painful mucositis, oral fungal infections, sialadenitis and dysphagia. For these reasons, preservation of normal saliva secretion is critical for the maintenance of functionally normal oral homeostasis and for keeping good health. Several strategies for restoring salivary gland function have been reported, from different points of view, based on the use of salivary-gland-derived epithelial stem/progenitor cells and tissue engineering approaches to induce organoids that mimic in vivo salivary glands. In this study, we clarified that inhibition of activin receptor-like kinase (Alk) signaling was essential for the induction of human salivary-gland-derived organoids, and demonstrated the usefulness of such organoids as an inflammatory disease model. In inflammatory conditions like sialadenitis, in general, pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α, also known as TNF) are upregulated, but their function is still unclear. In our established human salivary-gland-derived organoid culture system, we successfully induced organoid swelling by stimulation with carbachol, a non-selective cholinergic agonist, and forskolin, an activator of cystic fibrosis transmembrane conductance regulator (CFTR). Furthermore, we found that this organoid swelling was inhibited by TNF-α. From these results, we could clarify the inhibitory function of TNF-α on saliva secretion in vitro Thus, our established human salivary-gland-derived organoids would be useful for in vitro analyses of the morphological and functional changes involved in salivary gland dysfunctions in several research fields, such as pathobiology, inflammation and regenerative medicine.This article has an associated First Person interview with the first author of the paper.

Extracellular calcium stimulates osteogenic differentiation of human adipose-derived stem cells by enhancing bone morphogenetic protein-2 expression.

Bone morphogenetic protein-2 (BMP-2) promotes the differentiation of non-osteogenic mesenchymal cells to osteogenic cells. In this study, we isolated human adipose-derived stem cells (hASCs) and investigated the effects of recombinant human BMP-2 (rhBMP-2) and extracellular Ca2+ concentration ([Ca2+]out) on the osteogenic differentiation of hASCs. rhBMP-2 promoted calcium deposition in hASCs and stimulated the mRNA expressions of six proteins known to be involved in the osteogenic differentiation of hASCs: Runx2, osterix, alkaline phosphatase, osteonectin, bone sialoprotein and osteocalcin. Elevation of [Ca2+]out enhanced the level of alkaline phosphatase enzyme, increased the mRNA expressions of Runx2 and osteocalcin and induced the expressions of BMP-2 mRNA and protein in hASCs. Elevation of [Ca2+]out transiently increased the intracellular Ca2+ concentration ([Ca2+]in) due to activation of the calcium-sensing receptor (CaSR). The Ca2+-induced expressions of BMP-2 mRNA and protein were inhibited by the calmodulin antagonist, W-7. Furthermore, elevation of [Ca2+]out decreased the cytoplasmic level of phosphorylated nuclear factor of activated T-cell-2 (NFAT-2) and increased the nuclear level of dephosphorylated NFAT2. Taken together, these results suggest that rhBMP-2 promotes the osteogenic differentiation of hASCs. Furthermore, an increase in [Ca2+]out enhances the expression of BMP-2 via activation of the CaSR, elevation of [Ca2+]in and stimulation of Ca2+/calmodulin-dependent NFAT-signaling pathways.

Impaired Junctions and Invaded Macrophages in Oral Epithelia With Oral Pain.

Recurrent or chronic oral pain is a great burden for patients. Recently, the links between epithelial barrier loss and disease were extended to include initiation and propagation. To explore the effects of pathohistological changes in oral epithelia on pain, we utilized labial mucosa samples in diagnostic labial gland biopsies from patients with suspected Sjögren's syndrome (SS), because they frequently experience pain and discomfort. In most labial mucosa samples from patients diagnosed with SS, disseminated epithelial cellular edema was prevalent as ballooning degeneration. The disrupted epithelia contained larger numbers of infiltrating macrophages in patients with oral pain than in patients without pain. Immunohistochemistry revealed that edematous areas were distinct from normal areas, with disarranged cell-cell adhesion molecules (filamentous actin, E-cadherin, ß-catenin). Furthermore, edematous areas were devoid of immunostaining for transient receptor potential channel vanilloid 4 (TRPV4), a key molecule in adherens junctions. In an investigation on whether impaired TRPV4 affect cell-cell adhesion, calcium stimulation induced intimate cell-cell contacts among oral epithelial cells from wild-type mice, while intercellular spaces were apparent in cells from TRPV4-knockout mice. The present findings highlight the relationship between macrophages and epithelia in oral pain processing, and identify TRPV4-mediated cell-cell contacts as a possible target for pain treatment.