Expression of the janus kinases-signal transducers and activators of transcription pathway in Hassall's corpuscles of the human thymus.
The janus kinases (JAK) and signal transducers and activators of transcription (STAT) pathway has been shown to play a key role in cytokine-mediated signal transduction, and to regulate growth, differentiation, and death of both normal and transformed cells. In the present study, we investigated immunohistochemically the distribution of the JAK-STAT pathway in the human thymus. Various elements of the pathway were abundantly expressed in Hassall's corpuscles, located in the thymus medulla and representing terminal stages of the thymic medullary epithelium. Furthermore, the elements of the pathway showed distinct localization in Hassall's corpuscles. JAK1, JAK2, and TYK2 were expressed in high amounts in the entirety of Hassall's corpuscles, whereas JAK3 was in the outer layer. STAT1, STAT2, and STAT6 were abundantly expressed in the entire Hassall's corpuscles, whereas STAT5 was in the outer layer. These findings strongly suggest that the JAK-STAT pathway may play a role in thymic medullary epithelial maturation.
Department of Legal Medicine, Osaka Medical College, Takatsuki, Japan.
H
H
Nishio
K
K
Matsui
H
H
Tsuji
A
A
Tamura
K
K
Suzuki
D002675:Child, Preschool; D004268:DNA-Binding Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D008297:Male; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000032:analysis*; D011506:Proteins / Q000032:analysis; D011518:Proto-Oncogene Proteins; D050794:STAT1 Transcription Factor; D050795:STAT2 Transcription Factor; D050800:STAT6 Transcription Factor; D015398:Signal Transduction / Q000502:physiology*; D053634:TYK2 Kinase; D013950:Thymus Gland / Q000737:chemistry / Q000201:enzymology* / Q000648:ultrastructure; D015534:Trans-Activators / Q000032:analysis; D015533:Transcriptional Activation / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism
D004268:DNA-Binding Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050795:STAT2 Transcription Factor; C494084:STAT2 protein, human; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D015534:Trans-Activators; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; C507924:JAK2 protein, human; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D053634:TYK2 Kinase; C070139:TYK2 protein, human