Effects of prolactin on HLA-DR and CD40 expressions by human thyrocytes

Objective To study the effects of prolactin(PRL) on HLA-DR and CD40 expressions by human thyrocytes,and to investigate the possible mechanisms for PRL to affect the development of Graves'disease(GD).Methods Thyrocytes in secondary culture,which were from GD thyroid glands the tissues adjacent to the lwesions of multinodular goiter and andenoma(control group),were treated respectively with ovine PRL (oPRL),interferon-γ(IFN-γ),interlukin-4(IL-4)and oPRL plus IFN-γ(10U/ml)or IL-4(5ng/ml)for 7days.HLA-DR and CD40 expressions on the thyrocytes were determined by immunofluorescent staining and flow cytometry. Results oPRL(12.5ng/ml-1000ng/ml)had no significant direct effect on HLA-DR or CD40 expression.It did not significantly affect the stimulation of HLA-DR expressions on the rwo groups of thyrocyte treated with IFN-γ or on GD thyrocytes treated with IL-4.oPRL could antagonize the stimulation of CD40 expressions by IFN-γ and the inhibition by IL-4 on both groups of thyrocytes.The antagonizing effects were related to the concentration of PRL.IFN-γ-stimulated percentages of CD40+ thyrocytes and delta mean fluorescence intensity(dMF)in both thyrocyte sources were significantly reduced in the presence of 200ng/ml oPRL(both GD and Control:P<0.01and P<0.05,respectively;Control:P<0.05)and 1000ng/ml oPRL(GD:P<0.01;Control:P<0.05).oPRL caused significant increasing in IL-4-inhibited percentages of CD40+ cells from the two groups of thyrocytes at 12.5ng/ml and 1000ng/ml and dMF from GD thyrocytes at 1000ng/ml(P<0.05).Conclusions PRL can exert indirect effects on CD40 expressions on thyrocytes by antagonizing the modulatory actions of IFN-γand IL-4 with dose-related effects.This may be one important mechanism for PRL to affect the development of GD.

Preliminary Study on Chinese Drug-Induced Apoptosis of Thyrocytes in Graves' Disease

Objective: To investigate the cellular and molecular mechanisms of some Chinese drugs on apoptosis of thyrocytes in Graves' disease. Methods: Two to ten weeks before and after using Chinese drugs on 13 Graves' disease patients with anti-thyroid drugs, patients' thyroid tissue was aspired with percutaneous puncturing needle. The effects of some Chinese drugs on thyrocytes was studied by applying cell morphology (stained with nuclear fast red, NFR), flow cytometry (stained with propidium iodide, PI), and terminal uridine deoxynucleotidyl end-labelling (TUNEL) technique (alkaline phosphatase and CBIP/NBT, NFR). The size of thyroid gland was measured by color Doppler ultrasonography. Results: After Chinese drug treatment, compared with single anti-thyroid drug group, the size of thyroid was significantly reduced (P<0.01). The apoptosis of thyrocytes can be observed by cell morphology such as chromatin condensation and nuclear fragmentation. The apoptosis rate is 18.66%±20.01% (n=13) in anti-thyroid drugs plus Chinese drugs group, 2.11%±1.78% (n=13) in single anti-thyroid drug group (P<0.01). For up to 2-10 weeks, more TUNEL-positive cells were found after treatment with Chinese drugs than those treated with anti-thyroid drug alone. Conclusion: Some Chinese drugs when used in combination with anti-thyroid drugs in treating Graves' disease could induce apoptosis of thyrocytes.