Mast cells in human testicular biopsies from patients with mixed atrophy: increased numbers, heterogeneity, and expression of cyclooxygenase 2 and prostaglandin D2 synthase  Harald Welter, Ph.D., Frank M. Köhn, M.D., Artur Mayerhofer, M.D.  Fertility and Sterility  Volume 96, Issue 2, Pages 309-313 (August 2011) DOI: 10.1016/j.fertnstert.2011.05.035 Copyright © 2011 American Society for Reproductive Medicine Terms and Conditions

Figure 1 Tryptase and cyclooxygenase 2 (COX2) in human testicular biopsies. Representative sections from patients with normal spermatogenesis (A and B) and with mixed atrophy (MA) (C to G) are shown. (A) A few tryptase-positive mast cells (MCs; black arrows) are present, but immunostaining of a consecutive section for COX2 (B) is negative. (C) COX2-immunoreactive Leydig cells derived from an MA sample form groups (enclosed by white arrows). (D and E) Sequential sections from an MA biopsy were stained for tryptase and COX2, respectively. Note that MCs are accumulating, especially in the walls of a seminiferous tubule (T) with impaired spermatogenesis (boxed area). The letter B denotes blood vessel. (F and G) Enlarged regions of the boxed areas in D and E, respectively. Also note the tryptase-positive MCs in the interstitial spaces (black arrowheads) and within the thickened peritubular wall (open arrowheads), as well as the COX2/tryptase coexpression in the MCs in G. The inset in G shows an isotype control with an equivalent antibody concentration. Bars = 50 μm. Fertility and Sterility 2011 96, 309-313DOI: (10.1016/j.fertnstert.2011.05.035) Copyright © 2011 American Society for Reproductive Medicine Terms and Conditions

Figure 2 Tryptase- and cyclooxygenase 2–immunostained mast cells. Data are depicted as mast cells per tubule in normal (n = 3) and mixed atrophy (MA) (n = 13) specimens in a box and whisker plot. The box represents the interquartile range (25th–75th percentiles), and the line within the box is the median value. Bottom and top bars of the whisker indicate minimum and maximum of the data, respectively. ★ indicates statistically significant differences (P<.05, unpaired t test). INT = interstitial; n.s. = nonsignificant; PT = peritubular. Fertility and Sterility 2011 96, 309-313DOI: (10.1016/j.fertnstert.2011.05.035) Copyright © 2011 American Society for Reproductive Medicine Terms and Conditions

Figure 3 Laser microdissection and transmission electron microscopy studies showing cyclooxygenase 2 (COX2)/prostaglandin D synthase hematopoietic type (PGDS-H) expression and a maturing mast cell (MC). (A) A peritubular tryptase- and COX2-positive MC (arrow) before and after laser microdissection (inset). Tissue of the seminiferous tubular (TUB) and interstitial (INT; pictures not shown) compartments were isolated in the same way and subjected to nested reverse transcriptase polymerase chain reaction. Bar = 50 μm. (B) Ethidium bromide–stained agarose gel showing results of a reverse transcriptase polymerase chain reaction experiment. Expression of PGDS-H was identified in human testicular MCs and INT but not in the TUB, whereas COX2 mRNA was detected in all human testicular compartments tested. Control (−): testicular cDNA was replaced by water. (C) Transmission electron microscopy view of a developing (young) human testicular MC. Note that only few electron-dense granules are seen in this MC, which was located in the INT. Bar = 3 μm. Fertility and Sterility 2011 96, 309-313DOI: (10.1016/j.fertnstert.2011.05.035) Copyright © 2011 American Society for Reproductive Medicine Terms and Conditions