Cell-Type-Specific Expression of Hyaluronan Synthases HAS2 and HAS3 Promotes Goblet Cell Hyperplasia in Allergic Airway Inflammation.

Allergic rhinitis (AR) is a multifactorial airway disease characterized by basal and goblet cell hyperplasia. Hyaluronic acid (HA) is a major component of extracellular matrix and a critical contributor to tissue repair and remodeling after injury. We previously demonstrated that the intermediate progenitor cell (IPC) surface marker CD44v3 is upregulated in the basal and suprabasal layers of well-differentiated primary human nasal epithelial (HNE) cells after stimulation with the Th2 (T-helper cell type 2) cytokine IL-4, and an antibody blocking the CD44v3-HA interaction suppressed IL-4-induced goblet cell hyperplasia. We now show that the expression of HA and two HA synthases, HAS2 and HAS3, was upregulated in both the nasal surface epithelium of subjects with AR and IL-4-stimulated HNE cells. Inhibition of HA synthesis by 4-methylumbelliferone suppressed IL-4-induced goblet cell hyperplasia. Moreover, HAS2 and HAS3 were expressed in IPCs depending on the differentiation events, as follows: the rapid, transient upregulation of HAS2 induced basal IPC proliferation and basal-to-suprabasal transition, whereas the delayed upregulation of HAS3 promoted the transition of suprabasal IPCs to a goblet cell fate. 4-methylumbelliferone treatment in a house dust mite-induced murine AR model attenuated goblet cell metaplasia. Last, HA concentrations in nasal epithelial lining fluids from patients with AR positively correlated with the concentrations of mediators causing allergic inflammation. These data suggest that HA produced after the sequential upregulation of HAS2 and HAS3 contributes to goblet cell hyperplasia in allergic airway inflammation and modulates disease progression.

CD44v3-Positive Intermediate Progenitor Cells Contribute to Airway Goblet Cell Hyperplasia.

In allergic airway diseases, intermediate progenitor cells (IPCs) increase in number in the surface epithelium. IPCs arise from basal cells, the origin of hallmark pathological changes, including goblet cell hyperplasia and mucus hypersecretion. Thus, targeting IPCs will benefit future treatment of allergic airway diseases. However, the lack of adequate cell surface markers for IPCs limits their identification and characterization. We now show that CD44 containing exon v3 (CD44v3) is a surface marker for IPCs that are capable of both proliferating and generating differentiated goblet cells in allergic human nasal epithelium. In primary human nasal epithelial cells that had differentiated at an air-liquid interface, IL-4 upregulated mRNA expression of three CD44v variants that include exon v3 (CD44v3-v6, CD44v3,v8-v10, and CD44v3-v10), and it induced expression of CD44v3 protein in the basal and suprabasal layers of the culture. FACS analysis revealed two subpopulations differing in CD44v3 concentrations, as follows: CD44v3low cells expressed high amounts of proliferative and basal cell markers (Ki-67 and TP63), whereas CD44v3high cells strongly expressed progenitor and immature and mature goblet cell markers (SOX2, CA2, and SPDEF). Importantly, a blocking anti-CD44 antibody suppressed IL-4-induced mucin production by human nasal epithelial cells. Furthermore, CD44v3 was coexpressed with TP63, KRT5, or SOX2 and was upregulated in the basal and suprabasal layers of the nasal surface epithelium of subjects with allergic rhinitis. Taken together, these data demonstrate that high CD44v3 expression contributes to goblet cell hyperplasia in inflammation of the allergic airway.

The polyherbal composition Gyeongshingangjeehwan 18 attenuates glucose intolerance and pancreatic steatosis in C57BL/6J mice on a high-fat diet.

Ethnopharmacologic relevance: Gyeongshingangjeehwan 18 (GGEx18) is a polyherbal composition derived from Ephedra sinica Stapf (Ephedraceae), Laminaria japonica Aresch (Laminariaceae), and Rheum palmatum L. (Polygonaceae) that is used as an antiobesity drug in Korean clinics. Its constituents are traditionally known to combat obesity, dyslipidemia, and insulin resistance. OBJECTIVE: This study was undertaken to investigate the effects of GGEx18 on glucose metabolism and pancreatic steatosis in obese C57BL/6 J mice fed a high-fat diet (HFD) and to examine the related cellular and molecular mechanisms. MATERIALS AND METHODS: The mice were grouped and fed for 13 weeks as follows: 1) low-fat diet, 2) HFD, or 3) HFD supplemented with GGEx18 (500 mg/kg/day). Various factors affecting insulin sensitivity and pancreatic function were then assessed via blood analysis, histology, immunohistochemistry, and real-time polymerase chain reaction. RESULTS: GGEx18 treatment of obese mice reduced body weight, total fat, and visceral fat mass. GGEx18 inhibited hyperglycemia and hyperinsulinemia and improved glucose and insulin tolerance. GGEx18 also decreased serum leptin levels and concomitantly increased adiponectin levels. Furthermore, GGEx18-treated mice exhibited reduced pancreatic fat accumulation and normalized insulin-secreting ß-cell area. GGEx18 increased pancreatic expression of genes promoting fatty acid ß-oxidation (i.e., MCAD and VLCAD), whereas expression levels of lipogenesis-related genes (i.e., PPARγ, SREBP-1c, and FAS) declined. DISCUSSION AND CONCLUSION: GGEx18 curtailed impaired glucose metabolism and pancreatic steatosis in our mouse model by regulating pancreatic genes that govern lipid metabolism and improving insulin sensitivity. This composition may benefit patients with impaired glucose tolerance, insulin resistance, and pancreatic dysfunction.