Immunological characterization and immunocytochemical localization of a progesterone-dependent cat endometrial secretory protein

Activation of lysosomal cathepsins in pregnant bovine leukocytes

In ruminants, interferon-tau (IFNT)-mediated expression of interferon-stimulated genes in peripheral blood leukocytes (PBLs) can indicate pregnancy. Recently, type 1 IFN-mediated activation of lysosomes and lysosomal cathepsins (CTSs) was observed in immune cells. This study investigated the status of lysosomal CTSs and lysosomes in PBLs collected from pregnant (P) and non-pregnant (NP) dairy cows, and conducted in vitro IFNT stimulation of NP blood leukocytes. Blood samples were collected 0, 7, 14 and 18 days post-artificial insemination, and the peripheral blood mononuclear cells (PBMCs) and polymorphonuclear granulocytes (PMNs) separated. The fluorescent activity of CTSB and CTSK in PMNs significantly increased with the progress of pregnancy, especially on day 18. In vitro supplementation of IFNT significantly increased the activities of CTSB and CTSK in NP PBMCs and PMNs. CTSB expression was significantly higher in PBMCs and PMNs collected from P day-18 cows than from NP cows, whereas there was no difference in CTSK expression. IFNT increased CTSB expression but did not affect CTSK expression. Immunodetection showed an increase of CTSB in P day-18 PBMCs and PMNs. In vitro stimulation of IFNT increased CTSB in NP PBMCs and PMNs. Lysosomal acidification showed a significant increase in P day-18 PBMCs and PMNs. IFNT also stimulated lysosomal acidification. Expressions of lysosome-associated membrane protein (LAMP) 1 and LAMP2 were significantly higher in P day-18 PBMCs and PMNs. The results suggest that pregnancy-specific activation of lysosomal functions by CTS activation in blood leukocytes is highly associated with IFNT during maternal and fetal recognition of pregnancy.

Differential Expression of Cathepsins and Cystatin C in Ovine Uteroplacental Tissues

Cathepsins (CTSs) are peptidases that have biological roles in degrading extracellular matrix, catabolism of intracellular proteins, and processing of pro-hormones. Cystatin C (CST3) is a secreted inhibitor of lysosomal cysteine proteases cathepsin B (CTSB) and CTSL. Our working hypothesis is that cathepsins and cystatins play important roles in implantation and placentation in sheep. Expression of CTSB, CTSD, CTSH, CTSK, CTSL, CTSS, CTSZ, and CST3 mRNAs was detected in ovine uteroplacental tissues with distinct temporal and/or spatial expression patterns between Days 40 and 120 of pregnancy. Of particular note, CTSB, CTSD, and CTSZ mRNAs were predominantly detected in the chorion of the placenta and were more abundant in the placentomes than the intercaruncular endometria. CTSL and CST3 mRNAs were abundant in the endometrial epithelia and chorion, whereas CTSK, CTSS and CTSH mRNAs were most abundant in the stratum compactum stroma of the intercaruncular endometrium. Consistent with localisation of mRNAs, immunoreactive CTSL and CST3 proteins were mainly observed in the intercaruncular endometrial glands and intercotyledonary placenta during later pregnancy. These results support the working hypothesis that CTS and CST3 in uteroplacental tissues are involved in endometrial remodelling and placentation in sheep.

Cathepsins in the ovine uterus: regulation by pregnancy, progesterone, and interferon tau

Cathepsins (CTS) are peptidases that have biological roles in degrading extracellular matrix, catabolism of intracellular proteins, and processing of prohormones. Expression of CTSB, CTSD, CTSH, CTSK, CTSL, CTSS, and CTSZ genes was detected in the endometria of cyclic and early pregnant ewes with distinct temporal and spatial expression patterns. In the d 18 and 20 conceptus, expression of CTSB, CTSD, CTSL, and CTSZ mRNA was detected in the trophectoderm. Of particular note, CTSL mRNA was the most abundant CTS mRNA in the ovine endometrium and detected only in the luminal epithelium and superficial glandular epithelium of cyclic and pregnant ewes. CTSL mRNA increased 8-fold between d 10 and 18 in endometria of pregnant ewes, whereas it declined between d 14 and 16 in cyclic ewes. CTSL protein was also detected in conceptus trophectoderm, and pro-CTSL was detected in uterine flushings from ewes between d 12 and 16 of pregnancy. In ovariectomized and catheterized ewes, CTSL mRNA in the endometrium was increased by progesterone and intrauterine injections of ovine interferon (IFN)tau. Other endometrial CTS genes were also regulated by progesterone alone (CTSB, CTSK, CTSS, and CTSZ) or progesterone and IFNtau (CTSH, CTSK, CTSS, and CTSZ). These results indicate that CTS of endometrial and conceptus origin may regulate endometrial remodeling and conceptus implantation, endometrial CTS genes are regulated by ovarian and placental hormones, and CTSL is a novel IFNtau-stimulated gene expressed only in luminal epithelium and superficial glandular epithelium of the endometrium.

Expression of cathepsin L in normal endometrium and endometrial cancer

OBJECTIVE

To evaluate the expression of cathepsin L in normal endometrium and endometrial adenocarcinoma.

STUDY DESIGN

Tissue from eight cases of G1 and eight of G2 endometrioid adenocarcinoma, and 15 normal endometrial specimens were examined by immunohistochemistry.

RESULTS

In the normal endometrium, cathepsin L was expressed in a few cell layers of the apical part of the glandular epithelium throughout the menstrual cycle. In the carcinomas, there was an inverse correlation between the grade of tumor and the cathepsin L expression.

CONCLUSION

Cathepsin L expression may cease during endometrial carcinogenesis and its expression may be less important in tumor progression than it is in tumors of other tissues.

Immunological detection of cat uterine proteins in ferrets, dogs and baboons

In the cat, a high molecular weight (greater than 320 kDa) estrogen (E2)-dependent protein (CUPED) and a group of low molecular weight (28 kDa, 36 kDa, 41 kDa) progesterone (P)-dependent proteins (PDP) are synthesized by the epithelial cells of the deep uterine glands and secreted into the lumen. The present study was designed to investigate the possibility that other species synthesize proteins similar to CUPED and PDP in response to steroids. Uterine flushings and media from cultured endometrial explants obtained from E2 or P dominated animals were analyzed on Western blots for the presence of proteins which cross-react with antibodies raised against CUPED and PDP. CUPED antibody immunoreacted with a protein band at approximately the same molecular weight as CUPED in the media and flushings from E2-treated ferret, dog and baboon, but not from rat, mouse or hamster. In the cat, ferret and dog, specific immunocytochemical staining was observed in the apical portion of the secretory cells. In the baboon, staining was observed in both the basal and apical areas of the epithelial cells. The presence of CUPED in the uterine lumen during the E2-dominated phase of the reproductive cycle in several species suggests that CUPED may play a general role in providing the necessary biochemical milieu for reproductive success. The PDP antibody did not cross-react with proteins in the media of species other than cat, and therefore may be unique to the cat.