Mast cells in human testicular biopsies from patients with mixed atrophy: increased numbers, heterogeneity, and expression of cyclooxygenase 2 and prostaglandin D2 synthase.
Paraules clau
Resum
OBJECTIVE
To determine intratesticular abundance and distribution of tryptase-positive mast cells (MCs) and to examine the expression of key enzymes of prostaglandin (PG) synthesis, cyclooxygenase 2 (COX2), and PGD2 synthase in the testes of men with mixed atrophy (MA) syndrome and in normal samples.
METHODS
Retrospective study.
METHODS
Academic research institute and andrology practice.
METHODS
Nineteen men.
METHODS
Testicular biopsies.
METHODS
Immunohistochemistry and evaluation of COX2 and tryptase-positive MCs, laser microdissection of immunoreactive cells followed by reverse transcriptase polymerase chain reaction for COX2 and PGDS-H mRNA, and transmission electron microscopy.
RESULTS
In line with previous studies, few tryptase-positive MCs, but no COX2-positive cells, were observed in testes with normal spermatogenesis. In MA samples, the number of tryptase-positive MCs was significantly increased and the cells accumulated in the walls of the seminiferous tubules. In 11 of 13 MA samples, COX2 protein was detected. In 2 cases, Leydig cells were positive; however, in all 11 of 13 cases, COX2 was localized to MCs, coexpressing tryptase. The proportion of MCs coexpressing COX2 varied from 4% to 35%. Laser microdissection of tryptase/COX2-positive MCs followed by reverse transcriptase polymerase chain reaction revealed PGDS-H mRNA. Transmission electron microscopy identified typical MCs with abundant granules and another subtype with only a few granules, implying that MCs may differentiate in the testes.
CONCLUSIONS
In patients with MA, testicular MC numbers and phenotypes change with respect to the ability to express COX2 and synthesize PGs. MCs and PGs have emerged as players in spermatogenic dysfunction.
