n-3 fatty acids modulate T-cell calcium signaling in obese macrosomic rats.
OBJECTIVE
We investigated the effects of a diet containing EPAX-7010, rich in PUFAs such as eicosapentaenoic acid [20:5(n-3)] and docosahexaenoic acid [22:6(n-3)], i.e., a PUFA/EPAX regimen, on T-cell activation in diabetic pregnant rats and their obese pups.


METHODS
Mild hyperglycemia in pregnant rats was induced by intraperitoneal injection of streptozotocin on Day 5 of gestation. T-cell blastogenesis was assayed by using (3)H-thymidine, whereas intracellular free calcium concentrations ([Ca(2+)]i) were measured by using Fura-2 in diabetic pregnant rats and their obese offspring.


RESULTS
Concavalin-A-stimulated T-cell proliferation was decreased in both pregnant diabetic rats and their obese pups as compared with control animals. Feeding the PUFA/EPAX diet restored T-cell proliferation in both groups of animals. We also employed ionomycin, which at 50 nM opens calcium channels, and thapsigargin (TG), which recruits [Ca(2+)]i from endoplasmic reticulum pool. We observed that ionomycin-induced increases in [Ca(2+)]i in T-cells of diabetic mothers and obese offspring were greater than in those of control rats. Furthermore, feeding PUFA/EPAX diet diminished significantly the ionomycin-evoked rise in [Ca(2+)]i in diabetic and obese animals. TG-induced increases in [Ca(2+)]i in T-cells of diabetic pregnant rats and their obese offspring were greater than in those of control rats. The feeding of the experimental diet significantly curtailed the TG-evoked increases in [Ca(2+)]i in both diabetic and obese rats.


CONCLUSIONS
Together, these observations provide evidence that T-cell activation and T-cell calcium signaling are altered during gestational diabetes and macrosomia. Hence, dietary fish oils, particularly eicosapentaenoic acid and docosahexaenoic acid, may restore these T-cell abnormalities.
Guermouche
Baya
B
Départment de Biologie, Faculté des Sciences, Université de Tlemcen, Algeria.
Yessoufou
Akadiri
A
Soulimane
Nassima
N
Merzouk
Hafida
H
Moutairou
Kabirou
K
Hichami
Aziz
A
Khan
Naim Akhtar
NA
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003208:Concanavalin A / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000276:immunology; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D005320:Fetal Macrosomia / Q000209:etiology / Q000276:immunology*; D005865:Gestational Age; D015759:Ionomycin / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D009765:Obesity / Q000209:etiology / Q000276:immunology*; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000150:complications / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D013154:Spleen; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019284:Thapsigargin / Q000494:pharmacology
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D003208:Concanavalin A; D015759:Ionomycin; D019284:Thapsigargin; D002118:Calcium