FMLP-, thapsigargin-, and H2O2-evoked changes in intracellular free calcium concentration in lymphocytes and neutrophils of type 2 diabetic patients
- 264 Downloads
Type 2 diabetic (T2DM) patients are immune-compromised having a higher susceptibility to infections and long-term complications in different parts of the body contributing to increased morbidity and mortality. A derangement in the homeostasis of intracellular free calcium concentration [Ca2+]i is known to be associated with several diseases in the body including T2DM. Both neutrophils and lymphocytes play active protective roles in host immune response to infection showing impairment in microbicidal functions including phagocytosis and chemotaxis which are calcium-dependent processes. This study evaluated the process of [Ca2+]i mobilization from both neutrophils and lymphocytes taken from blood of both T2DM patients and healthy age-matched control subjects investigating the effect of N-formyl-methionyl-leucyl-phenylalanine (fMLP), thapsigargin (TG), and hydrogen peroxide (H2O2) on [Ca2+]i homeostasis. This study employed isolated peripheral blood neutrophils and lymphocytes from 24 T2DM patients and 24 healthy volunteers. Either neutrophils or lymphocytes were stimulated separately with fMLP, TG, or H2O2. Induced changes in [Ca2+] in both neutrophils and lymphocytes were evaluated using spectrofluorometric methods. Stimulation of human neutrophils and lymphocytes with fMLP, TG, or H2O2 in the presence of [Ca2+]o resulted in significant decreases in [Ca2+]i mobilization from T2DM patients compared with healthy controls. These data indicate that neutrophils and lymphocytes from T2DM patients are less responsive to calcium mobilizing agents compared with granulocytes from healthy controls and this is possibly due to the hyperglycemia. The results suggest that agonist-evoked decrease in [Ca2+]i in immune cells might be one of the possible mechanisms of impaired immunity in diabetic patients.
KeywordsType 2 diabetes mellitus Lymphocytes Neutrophils Cytosolic calcium Agonists
The authors are indebted to all the research staff members of Department of Physiology, University of Extremadura, Badajoz, Spain and University of Central Lancashire, Lancashire Teaching Hospitals NHS Trust, UK for their support. All the Type 2 Diabetic patients and controls who have given their blood samples for this work are greatly acknowledged. Dr J. Espino is a recipient of a research grant from the Ministerio de Educación, Cultura y Deporte (AP2009-0753).
- 1.Kumar PJ, Clark M (2007) Diabetes mellitus and other disorders of metabolism. In: Kumar PJ, Clark M (eds) Textbook of medicine. Saunders, London, pp 1069–1122Google Scholar
- 6.Roitt I, Brostoff J, Male D (1996) Immunology, 4th edn. Mosby-Wolfe, LondonGoogle Scholar
- 9.Clausen T, Elbrink J, Martin BR (1974) Insulin controlling calcium distribution in muscle and fat cells. Acta Endocrinol 77:137–143Google Scholar
- 12.Berliner S, Rogowski O, Rotstein R, Fusman R, Shapira I, Bornstein NM (2000) Activated polymorphonuclear leukocytes and monocytes in the peripheral blood of patients with ischemic heart and brain conditions correspond to the presence of multiple risk factors for atherothrombosis. Cardiology 94:19–25PubMedCrossRefGoogle Scholar
- 20.Popko K, Winklewski P, Jakubczak B, Wasilewski R, Wasik M (2003) Changes in intracellular calcium free and calcium stored balance in children granulocytes after stimulation: preliminary results. Centr Eur J Immunol 28:62–66Google Scholar
- 29.Genestier AL, Michallet MC, Prévost G, Bellot G, Chalabreysse L, Peurol S, Thivolet F, Etienne J, Lina G, Vallette FM, Vandenesch F, Genestier L (2005) Staphylococcus aureus Panton–Valentine leukocidin directly targets mitochondria and induces Bax-independent apoptosis of human neutrophils. J Clin Invest 115:3117–3127PubMedCentralPubMedCrossRefGoogle Scholar