Members of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway are present and active in human sperm.
OBJECTIVE
To investigate whether components of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway are present and active in human sperm.


METHODS
Comparative study.


METHODS
Reproductive biology department.


METHODS
Nine sperm donors.


METHODS
Sperm were exposed to interferon-alpha (IFN-alpha), IFN-gamma, interleukin-12 (IL-12), Ca2+ ionophore (A23187), or progesterone under capacitating conditions.


METHODS
Cell lysates prepared from sperm and Jurkat T-cell line were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the expression of JAKs (1-3 and TYK 2) and STATs (1-6) was examined by Western blot analysis. Effect of IFN-alpha, IFN-gamma, IL-12, A23187, or progesterone on sperm STAT 1 or STAT 4 phosphorylation was determined by phospho-STAT 1 antibody or antiphosphotyrosine (APT) Western blot analysis. Indirect immunofluorescence and confocal laser scanning microscopy was used to confirm the specific staining of anti-TYK 2, anti-STAT 1, and anti-STAT 4 antibodies.


RESULTS
By Western blot analysis, only antibodies to TYK 2 of the JAK family, and antibodies to STAT 1 and STAT 4 members of the STAT family specifically recognized protein bands corresponding to TYK 2, STAT 1, and STAT 4 described in other cell types. By confocal microscopy, antibodies to TYK 2 reacted with the sperm tail as well as the apical region of sperm head, whereas antibodies to STAT 1 and STAT 4 reacted with the apical region of the sperm head. Tyrosine phosphorylation of STAT 1 in capacitated sperm was enhanced by IFN-alpha and IFN-gamma, and that of STAT 4 was enhanced by IL-12. Both A23187 and progesterone markedly inhibited tyrosine phosphorylation of sperm STAT 4.


CONCLUSIONS
Members of the JAK/STAT proteins, TYK 2, STAT 1, and STAT 4 are present and active in human sperm. The localization of STAT 1 and STAT 4 proteins to the apical region of the sperm head and their activation by IFN-alpha, IFN-gamma, or IL-12 implicate a role for sperm STAT proteins in fertilization. We hypothesize that sperm-derived phosphorylated STAT 1 and STAT 4 could contribute to the pool of transcription factors during sperm-oocyte fusion as well as transmit signal to the oocyte nucleus. Therefore, defects in sperm TYK 2 and STAT 1- or STAT 4-mediated signaling pathway may have relevance to male factor infertility.
D'Cruz
O J
OJ
Department of Reproductive Biology, Parker Hughes Institute, St. Paul, Minnesota 55113, USA. odcruz@ih.org
Vassilev
A O
AO
Uckun
F M
FM
D015153:Blotting, Western; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000494:pharmacology; D019169:Jurkat Cells; D008297:Male; D008854:Microscopy, Electron; D010766:Phosphorylation; D011374:Progesterone / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases; D011506:Proteins / Q000378:metabolism*; D050794:STAT1 Transcription Factor; D050797:STAT4 Transcription Factor; D015398:Signal Transduction; D013094:Spermatozoa / Q000187:drug effects / Q000201:enzymology*; D053634:TYK2 Kinase; D015534:Trans-Activators / Q000378:metabolism* / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism
D004268:DNA-Binding Proteins; D016898:Interferon-alpha; D011506:Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050797:STAT4 Transcription Factor; C494090:STAT4 protein, human; D015534:Trans-Activators; D018664:Interleukin-12; D000001:Calcimycin; D014443:Tyrosine; D011374:Progesterone; D007371:Interferon-gamma; D011505:Protein-Tyrosine Kinases; D053634:TYK2 Kinase; C070139:TYK2 protein, human; D002118:Calcium