Immunohistochemical analysis of bcl-2, Bax and Bak expression in thyroid glands from patients with Graves' disease.
In order to clarify the role of apoptosis and the expression of Bcl-2 family proteins in the pathology of Graves' disease (GD), we evaluated the apoptosis by in situ end-labeling of fragmented DNA and the expression of Bcl-2, Bax and Bak by immunohistochemistry in thyroid tissues from 20 patients with GD and in normal thyroid tissues from 6 patients with follicular adenoma (N). Apoptotic nuclei were found in thyrocytes and in germinal center of lymphoid follicles. Bcl-2 was strongly expressed in both GD and N thyrocytes. Bax was not expressed in either GD or N thyrocytes. Bak was expressed in thyrocytes from 5 of 20 patients with GD, while it was detected in all N thyrocytes. In lymphoid follicles Bcl-2 was expressed in the mantle zone, while Bax and Bak were both expressed in the germinal center. The percentage of apoptotic nuclei in GD thyrocytes was low (0~3.6%), and negatively correlated with the weight of the thyroid glands resected (rs = -0.43, P<0.05). It was greater in Bak-positive GD thyrocytes than in Bak-negative ones (mean +/- SD; 1.7 +/- 0.7% vs. 0.7 +/- 0.9%, P<0.05). These findings suggest that the differential expression of Bcl-2 family proteins in both thyrocytes and lymphoid follicles may be involved in the pathology of GD.
Hiromatsu
Yuji
Y
Division of Endocrinology and Metabolism, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.
Kaku
Hiroo
H
Mukai
Tokunori
T
Miyake
Ikuyo
I
Fukutani
Tomoka
T
Koga
Mari
M
Shoji
Shingo
S
Toda
Shuji
S
Koike
Norimasa
N
D000293:Adolescent; D000328:Adult; D017209:Apoptosis; D053938:DNA Fragmentation; D005260:Female; D006111:Graves Disease / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000032:analysis*; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D013961:Thyroid Gland / Q000737:chemistry*; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein
C494772:BAK1 protein, human; C494826:BAX protein, human; D008565:Membrane Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein