Leptin and leptin receptor expression in asthma

Immunofluorescence from NHBE cells for leptin (A) and leptin receptor (B). Particulars are shown in C and D. The expression of leptin receptor appears more apical than basolateral (magnification ×630). Bar = 10 μm. Negative controls are shown in E through H. Immunocytochemistry for leptin (I) and leptin receptor (J) from 16HBE cells (red), NHBE cells (K and L), and BECs (M and N; brown) is also shown (magnification at ×1000). Insets show negative controls.

Flow cytometric analysis for leptin receptor expression in 16HBE cells (A), NHBE cells (B), and BECs (C). Physical parameters (left) and overlay of fluorescence intensity (FL1; right) related to the expression of leptin receptor versus events histogram of cells cultured in medium. White peaks indicate negative controls. SSC-H, Side light scatter-height; FSC-H, forward light scatter-height.

Leptin receptor expression, TGF-β1 release, and cell proliferation by 16HBE cells. A, Leptin receptor expression in 16HBE cells cultured with medium, TGF-β1, FP, and anti–TGF-β1. B, Supernatants from 16HBE cells stimulated with leptin, leptin pharmacologic inhibitors, and TNF-α were assessed for TGF-β1 release (ELISA). C, 16HBE colony numbers on leptin incubation. ^∗P < .05, unpaired t test.

A, Immunohistochemistry for leptin on epithelium from bronchial biopsy specimens (brown). Healthy volunteers (C) and subjects with mild uncontrolled (UA), mild controlled (ICS), and severe (SDA) asthma are shown (magnification at ×400). Scale bar = 40 μm. B, Leptin expression is significantly lower^∗ in the UA (P < .001) and SDA (P < .001) groups versus the C group and significantly higher^∗∗ in the ICS group vs the UA (P < .03) and SDA (P < .01) groups.

A, Immunohistochemistry for leptin receptor on epithelium from bronchial biopsy specimens (brown) of healthy volunteers (C) and subjects with mild uncontrolled (UA), mild controlled (ICS), and severe (SDA) asthma (magnification at ×400). Scale bar = 40 μm. B, Leptin receptor expression is significantly lower^∗ in the UA (P < .01) and SDA (P < .001) groups versus the C group and significantly higher^∗∗ in the ICS group versus the UA (P < .01) and SDA (P < .01) groups.

A, Immunohistochemistry for TGF-β on epithelium from bronchial biopsy specimens (red) of healthy volunteers (C) and subjects with mild uncontrolled (UA), mild controlled (ICS), and severe (SDA) asthma (magnification at ×400). Scale bar = 40 μm. B, TGF-β expression is significantly higher^∗ in the UA group versus the C (P < .01), ICS (P < .05), and SDA (P < .03) groups.

A, Hematoxylin staining for RBM thickness from bronchial biopsy specimens (blue; magnification ×400). Scale bar = 40 μm. B, RBM thickness is significantly higher^∗ in subjects with mild uncontrolled asthma (UA; n = 8; P < .01), subjects with mild controlled asthma (ICS; n = 8; P < .04), and subjects with severe asthma (SDA; n = 15; P <0.001) versus healthy control volunteers (C; n = 15).

Correlations between leptin/leptin receptor and RBM. In bronchial epithelium leptin and leptin receptor expressions are positively correlated with each other (A). Leptin (B) and leptin receptor (C) expressions are inversely correlated with RBM thickness. Healthy volunteers (C; n = 15) and subjects with mild uncontrolled (UA; n = 8), mild controlled (ICS; n = 8), and severe (SDA; n = 15) asthma are shown.

Correlations between leptin/leptin receptor, TGF-β, and RBM. In bronchial epithelium leptin (A) and leptin receptor (B) expressions are inversely correlated with TGF-β expression. TGF-β expression is positively correlated with RBM thickness (C). Healthy control volunteers (C; n = 15) and subjects with mild uncontrolled (UA; n = 8) and mild controlled (ICS; n = 8) asthma are shown.