Effect of fluvastatin on apoptosis in human CD4+ T cells.

Statins are lipid-lowering agents with pleiotropic effects. We investigated the apoptotic effects of fluvastatin on peripheral CD4+ T cells from healthy subjects. Fluvastatin induced apoptosis in resting CD4+ T cells but not in CD4+ T cells strongly activated with a high concentration of PMA plus ionomycin (PMA/I) analyzed with annexin V and propidium iodide staining. However, CD4+ T cells activated with a low concentration of PMA/I or with anti-CD3 antibodies were apoptotic after treatment with fluvastatin. Activities of caspases-8, -9, and -3 were increased in resting CD4+ T cells treated with fluvastatin (10 microM). In strongly activated CD4+ T cells, fluvastatin inhibited the activation of caspase-8 induced by PMA/I and increased caspase-9 activity. The caspase-3 activity did not differ between untreated and fluvastatin-treated strongly activated CD4+ T cells. Treatment with fluvastatin (10 microM) enhanced cytochrome c release and increased the Bax/Bcl-2 ratio in both resting and strongly activated CD4+ T cells. Although the in vitro concentration of fluvastatin used in this study is higher than in vivo, other factors may sensitize apoptotic cell death of CD4+ T cells in vivo. In conclusion, fluvastatin induces apoptosis in resting T cells but not in strongly activated T cells, a difference that might be due to the interaction between caspase-8 and caspase-9.

Increased levels and activity of matrix metalloproteinase-9 in obstructive sleep apnea syndrome.

Matrix metalloproteinases (MMPs) are involved in the pathogenesis of cardiovascular diseases. We examined serum levels of MMP-9 and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), activity of MMP-9, and the effect of nasal continuous positive airway pressure (nCPAP) in patients with obstructive sleep apnea syndrome (OSAS). After polysomnography, venous blood was collected at 5:00 A.M. from 44 patients with OSAS and 18 control subjects who were obese, and serum levels of MMP-9, TIMP-1, and enzymatic activity of MMP-9 were measured. In addition, the effects of 1 month of treatment with nCPAP were studied in patients with moderate to severe OSAS. Although serum levels of MMP-9 (p < 0.03) and MMP-9 activity (p < 0.01) were higher in patients with OSAS than in control subjects who were obese, TIMP-1 levels did not differ significantly. In patients with OSAS, the severity of OSAS was the primary factor influencing levels (p < 0.01) and activity (p < 0.01) of MMP-9. nCPAP significantly decreased serum levels (p < 0.01) and activity (p < 0.001) of MMP-9 but did not affect TIMP-1 levels. Therefore, OSAS may increase risks of cardiovascular morbidity, and nCPAP might be useful for decreasing these risks.

IgE binding to raw and boiled shrimp proteins in atopic and nonatopic patients with adverse reactions to shrimp.

BACKGROUND: Characterization of seafood allergens is important to understand the immune response to these allergens. Moreover, a detailed comparison between atopic and nonatopic patients with adverse reactions to shrimp has never been reported. METHODS: Raw and boiled shrimp extracts were analyzed by immunoblotting using sera from 9 atopic and 7 nonatopic patients with a history of adverse reactions to shrimp, and 13 control subjects. Total IgE, specific IgE and skin prick tests (SPT) to shrimp were also investigated. RESULTS: The level of specific IgE to shrimp was higher in atopic patients than nonatopic patients (p<0.05). Symptoms, SPT results and major allergens involved were similar in atopic and nonatopic patients. The 16.5-kD protein had the highest frequency of IgE binding followed by the 40-kD protein in these patients. Other minor IgE-binding proteins were observed at the 20-, 22-, 54-, 72-, 129- and 140-kD regions. Patients who had binding to the 16.5-kD protein had either positive (25% raw/31% cooked) or negative (13% raw/cooked) CAP-FEIA-RAST, while patients who recognized the 40-kD protein all had positive (31% raw/19% cooked) CAP-FEIA-RAST. All control subjects had negative immunoblots for these two proteins. CONCLUSION: The 16.5-kD protein was the most frequent protein identified regardless of CAP-FEIA-RAST results, while the 40-kD protein was only present in patients with positive CAP-FEIA-RAST. Therefore, 16.5-kD protein may be an important allergen that is clinically relevant in both atopic and nonatopic patients with adverse reactions to shrimp even if it is not detected by the CAP-FEIA-RAST system.