The effect of disodium cromoglycate (DSCG) on in vitro proliferation of CD4+, CD8+, and CD19+ cell populations derived from allergic and healthy donors

Disodium cromoglycate inhibits asthma-like features induced by sphingosine-1-phosphate

Compelling evidence suggests the involvement of sphingosine-1-phosphate (S1P) in the pathogenesis of asthma. The systemic administration of S1P causes asthma like features in the mouse involving mast cells. In this study we investigated whether disodium cromoglycate (DSCG), administered as a preventative treatment as in human therapy, could affect S1P effects on airways. BALB/c mice, treated with DSCG, received subcutaneous administration of S1P. Bronchi and pulmonary tissues were collected and functional, molecular and cellular studies were performed. DSCG inhibited S1P-induced airway hyper-reactivity as well as pulmonary inflammation. DSCG decreased the recruitment of solely mast cells and B cells in the lung. IgE serum levels, prostaglandin D₂, mucus production and IL-13 were also reduced when mice were pretreated with DSCG. S1P induced pulmonary expression of CD23 on T and B cells, that was reversed by DSCG. Conversely, S1P failed to upregulate CD23 in mast cell-deficient Kit ^W-sh/W-sh mice. In conclusion we have shown that DSCG inhibits S1P-induced asthma like features in the mouse. This beneficial effect is due to a regulatory action on mast cell activity, and in turn to an inhibition of IgE-dependent T and B cells responses.

Cromolyn ameliorates acute and chronic injury in a rat lung transplant model

BACKGROUND

Mast cells have been associated with obliterative bronchiolitis (OB) in human pulmonary allografts, although their role in the development of OB remains unknown.

METHODS

In this study, we evaluated the role of mast cells in pulmonary allograft rejection using an orthotopic rat pulmonary allograft model that utilizes chronic aspiration of gastric fluid to reliably obtain OB. Pulmonary allograft recipients (n = 35) received chronic aspiration of gastric fluid with (n = 10) and without (n = 16) treatment with a mast cell membrane stabilizer, cromolyn sodium, or chronic aspiration with normal saline (n = 9) as a control.

RESULTS

The acute graft injury associated with long ischemic time in the model (6 hours total ischemic time; typical acute graft injury rate ~30%) was apparently blocked by cromolyn, because peri-operative mortality associated with the acute graft injury was not observed in any of the animals receiving cromolyn (p = 0.045). Further, the rats receiving cromolyn developed significantly fewer OB lesions than those treated with gastric fluid alone (p < 0.001), with a mean reduction of 46% of the airways affected.

CONCLUSIONS

These findings provide impetus for further studies aimed at elucidating the effects of cromolyn and the role of mast cells in pulmonary allotransplantation.

Disodium cromoglycate suppresses the induction of cysteinyl leukotriene synthesis during granulocytic differentiation in HL-60 cells

OBJECTIVES

Disodium cromoglycate (DSCG) and nedocromil sodium are anti-asthma drugs that have a variety of physiological and biological effects. We examined whether DSCG affects the induction of cysteinyl Leukotriene (cysLT) synthesis during dimethyl sulfoxide (DMSO)-induced granulocytic differentiation in HL-60 cells.

METHODS

HL-60 cells were differentiated to mature granulocyte-like cells by DMSO in the presence or absence of DSCG for 5 days. Then, we measured A23187-stimulated production of LTC4, an initial product of cysLTs. We also examined the mRNA expression and enzyme activity of LTC4 synthase and other LT-synthetic enzymes.

RESULTS

The amount of LTC4 production was 732.0+/-19.0 pg/10(6) cells in DMSO-differentiated HL-60 cells. The value was significantly decreased to 420.7+/-22.7 pg/10(6) cells in the presence of DSCG at 100 microg/ml. The DMSO-induced mRNA expression and enzyme activity of LTC4 synthase was also suppressed by DSCG.

CONCLUSIONS

Our results indicate that DSCG suppresses the DMSO-induced LTC4 synthase-activity by inhibiting mRNA expression of LTC4 synthase, which might be a novel anti-allergic action of DSCG.

The effect of H1 receptor antagonists on peripheral blood mononuclear cells, adenoid cells and primary cell lines

This study describes the in vitro effect of three H1 receptor antagonists (dexchlorpheniramine, terfenadine and loratadine) on human peripheral blood mononuclear cells (PBMC, n = 30) from allergic patients and healthy individuals. The three H1 receptor antagonists significantly inhibited antigen/mitogen-induced PBMC proliferation in a concentration-dependent manner. Allergen-specific T-cell responses in allergic individuals were similarly inhibited. The effect of the three drugs was also tested in cultures of mononuclear cells derived from adenoid tissue. The growth kinetics were investigated using spontaneously proliferating cell lines to examine whether the inhibition was caused by general toxicity. Three cell lines, HCT 8 (an ileocaecal adenocarcinoma) RPMI 8866 (B-cell line) and 166 A2 (T hybridoma) were tested. Loratadine (< 0.03 microM) and dexchlorpheniramine (< 0.62 microM) altered the kinetics of HCT 8 and RPMI 8866, respectively. When testing RPMI 8866 and 166 A2, the growth-inhibitory effect of terfenadine and loratadine could be neutralized by addition of cell culture filtrate from RPMI 8866 or 166 A2. These culture filtrates are rich in soluble low-affinity IgE receptor (sCD23) and IgE-binding factor (IgEBF), respectively. Our findings show that the antihistamines investigated display some non-convential in vitro anti-allergic properties possibly not related to their interaction with the H1 receptor. In addition, our results suggest: a) The H1 receptor antagonists used differ in their pattern of cell inhibition; b) The inhibitory effect is completely reversible at low drug concentrations.