Ca(2+)-modulated membrane guanylate cyclase in the testes.

To date, the calcium-regulated membrane guanylate cyclase Rod Outer Segment Guanylate Cyclase type 1 (ROS-GC1) transduction system in addition to photoreceptors is known to be expressed in three other types of neuronal cells: in the pinealocytes, mitral cells of the olfactory bulb and the gustatory epithelium of tongue. Very recent studies from our laboratory show that expression of ROS-GC1 is not restricted to the neuronal cells; the male gonads and the spermatozoa also express ROS-GC1. In this presentation, the authors review the existing information on the localization and function of guanylate cyclase with special emphasis on Ca(2+)-modulated membrane guanylate cyclase, ROS-GC1, in the testes. The role of ROS-GC1 and its Ca(2+)-sensing modulators in the processes of spermatogenesis and fertilization are discussed.

Aggregation of spectrin and PKCtheta is an early hallmark of fludarabine/mitoxantrone/dexamethasone-induced apoptosis in Jurkat T and HL60 cells.

It has been shown that changes in spectrin distribution in early apoptosis preceded changes in membrane asymmetry and phosphatidylserine (PS) exposure. PKCtheta was associated with spectrin during these changes, suggesting a possible role of spectrin/PKCtheta aggregation in regulation of early apoptotic events. Here we dissect this hypothesis using Jurkat T and HL60 cell lines as model systems. Immunofluorescent analysis of alphaIIbetaII spectrin arrangement in Jurkat T and HL60 cell lines revealed the redistribution of spectrin and PKCtheta into a polar aggregate in early apoptosis induced by fludarabine/mitoxantrone/dexamethasone (FND). The appearance of an alphaIIbetaII spectrin fraction that was insoluble in a non-ionic detergent (1% Triton X-100) was observed concomitantly with spectrin aggregation. The changes were observed within 2 h after cell exposure to FND, and preceded PS exposure. The changes seem to be restricted to spectrin and not to other cytoskeletal proteins such as actin or vimentin. In studies of the mechanism of these changes, we found that (i) neither changes in apoptosis regulatory genes (e.g., Bcl-2 family proteins) nor changes in cytoskeleton-associated proteins were detected in gene expression profiling of HL60 cells after the first hour of FND treatment, (ii) caspase-3, -7, -8, and -10 had minor involvement in the early apoptotic rearrangement of spectrin/PKCtheta, and (iii) spectrin aggregation was shown to be partially dependent on PKCtheta activity. Our results indicate that spectrin/PKCtheta aggregate formation is related to an early stage in drug-induced apoptosis and possibly may be regulated by PKCtheta activity. These findings indicate that spectrin/PKCtheta aggregation could be considered as a hallmark of early apoptosis and presents the potential to become a useful diagnostic tool for monitoring efficiency of chemotherapy as early as 24 h after treatment.

Coexpression of survivin and PCNA in pituitary tumors and normal pituitary.

OBJECTIVES: The survivin is the protein involved in regulation of basic and cycle-specific functions of cells both in normal and cancer tissue. Recent studies present survivin as a factor having the leading role in the regulation of apoptosis and mitosis as well as a target of anticancer therapy. The employing of survivin in this therapy is based on its high expression level in most human cancers, as well as its association with the disease's progression. The aim of our study was to evaluate the expression and localization of survivin's gene product on the protein level in different types of pituitary tumors and normal pituitary. The coexpression of survivin and proliferating cell nuclear antigen - PCNA in pituitary was also examined. DESIGN AND METHODS: The study was conducted on the postoperative pituitary tumors tissue taken during standard neurosurgical removal of tumor from 43 patients. The group of patients consists of 23 women and 20 men, aged from 27 to 71 years. As a control of the study three normal pituitary tissues obtained at the autopsy were used. Evaluation of survivin and PCNA expression was performed using immunohistochemical staining. RESULTS: The study demonstrated the presence of survivin in all analyzed by us pituitary tumors. Survivin was present also in normal pituitary tissue. The protein was localized mainly in cell's nuclei, however the less intense immunostaining was observed also in the cytoplasm of pituitary tumors cells. Furthermore survivin was found in normal pituitary, but the positive immunostaining was limited to a single cells. The analysis of pituitary tumor cells proliferation index based on PCNA reactivity showed that survivin is coexpressed with PCNA, especially in invasive tumors. CONCLUSIONS: The study documented the presence of survivin in different types of pituitary tumors as well as in normal pituitary. Additionally the coexpression of survivin and PCNA in tumor cells was shown. The expression of survivin in both normal and cancer pituitary cells suggests that it may play an important role in regulation of the gland's proliferation.

Reduction of human chorionic gonadotropin beta subunit expression by modified U1 snRNA caused apoptosis in cervical cancer cells.

BACKGROUND: Secretion of human chorionic gonadotropin, especially its beta subunit by malignant trophoblastic tumors and varieties of tumors of different origin is now well documented; however the role of hCG in tumorogenesis is still unknown. RESULTS: This study documents the molecular presence of human chorionic gonadotropin beta subunit in uterine cervix cancer tissues and investigates a novel technique to reduce hCGbeta levels based on expression of a modified U1 snRNA as a method to study the hormone's role in biology of human cervical cancer cells cultured in vitro. The property of U1 snRNA to block the accumulation of specific RNA transcript when it binds to its donor sequence within the 3' terminal exon was used. The first 10 nucleotides of the human U1 snRNA gene, which normally binds to the 5'ss in pre-mRNA were replaced by a sequence complementary to a 10-nt segment in the terminal exon of the hCGbeta mRNA. Three different 5' end-mutated U1 snRNA expression plasmids were tested, each targeting a different sequence in the hCGbeta mRNA, and we found each one blocked the expression of hCGbeta in HeLa cells, a cervix carcinoma cell line, as shown by immunohistochemistry and qRT-PCR. Reduction of hCGbeta levels resulted in a significantly increased apoptosis rate with almost 90% of cells transfected with modified anti-hCGbeta U1 snRNAs showing morphological changes characteristic of the apoptotic process. CONCLUSION: These data suggest that human chorionic gonadotropin beta subunit may act as a tumor growth-stimulating factor.

Caspase-3 activation and phosphatidylserine membrane translocation in human spermatozoa: is there a relationship?

The presence of biochemical signs of apoptosis in ejaculated spermatozoa suggests that apoptosis may be one of the pathways for sperm death. The relationship between the phosphatidylserine (PS) externalization and the presence of the active form of caspase-3 (CP-3) was studied in human spermatozoa after exposure to hydrogen peroxide (H(2)O(2)). Semen from 27 normozoospermic men was examined, as the neat semen, after swim-up isolation and after H(2)O(2) incubation, for the translocation of PS, activation of caspase-3 and mitochondrial membrane potential. The percentage of vital spermatozoa expressing PS translocation was lower than the percentage of vital spermatozoa with the active form of the caspase-3, either in neat (4.9 +/- 2.3% versus 19.7 +/- 6.2%, P < 0.001) or in swim-up semen (2.2 +/- 2.3% versus 4.8 +/- 2.9%, P < 0.01). After swim-up isolation, the percentage of vital spermatozoa with active caspase-3 decreased (P < 0.01). After H(2)O(2) stimulation of the swim-up semen fraction, a decrease in the mitochondrial membrane potential was observed (P < 0.001). Only the midpiece revealed PS translocation after H(2)O(2) stimulation, and it was also the only part to reveal the presence of the active form of caspase-3. All spermatozoa expressing the PS translocation revealed the presence of the active form of caspase-3.

Calcium-modulated rod outer segment membrane guanylate cyclase type 1 transduction machinery in the testes.

The importance of the second messengers, Ca(2+) and cyclic GMP, for the process of fertilization is well established; the mechanisms for their intracellular regulations in the testes are, however, poorly understood. This study documents the biochemical, molecular, and functional identity of a Ca(2+)-modulated membrane guanylate cyclase transduction machinery in bovine testes. The machinery is both inhibited and stimulated by free Ca(2+) levels. The Ca(2+)-sensor component of the inhibitory mode of the machinery is GCAP1 (guanylate cyclase activating protein type 1) and for the stimulatory mode is S100B. The transduction component is a Ca(2+)-driven rod outer segment membrane guanylate cyclase type 1, ROS-GC1. The cyclase is predominantly expressed in spermatogenic cells. GCAP1 expression is restricted to a small population of spermatogonia, whereas S100B is present in the majority of spermatocytes and spermatids. The expression of GCAP1 and S100B in spermatocytes and spermatids is mutually exclusive.

Localization of the DAZ gene expression in seminiferous tubules of patients with spermatogenic disorders.

The research on the expression and mutations of DAZ and its homologues in human and other mammals suggests that protein products of these genes can mainly affect development of germinal cells. The aim of the present study was to analyze the expression of the DAZ gene in seminiferous tubules of six men with spermatogenic disorders (hypospermatogenesis and spermatogenic arrest). The results based on the RT-PCR IS technique demonstrated that the DAZ product was present only in some seminiferous tubules and the fluorescence intensity was different within individual tubules. The most intense fluorescence characterised the spermatogonia, especially these organised in small groups inside separate tubules. In the patients with spermatogenic arrest at the spermatocyte stage, the DAZ gene transcripts were also found in primary spermatocytes. However, the fluorescence intensity of primary spermatocytes, except the fluorescence of the spermatocytes localised upon the lumen, was weaker than the fluorescence of spermatogonia. The results of our study showed that DAZ gene activity seems to correspond to the proliferative activity of stem cells of germinal epithelium.

Effects of galanin on proliferation and apoptosis of immature rat thymocytes.

Evidence indicates that some regulatory peptides (endothelins, cholecystokinin and VIP) are involved in the control of thymus growth, and we have investigated whether galanin may be included in this group of peptides. In fact, galanin, a 29-amino acid peptide acting through three subtypes of G protein-coupled receptors (GalR1, GalR2 and GalR3), seems to play a role in the control of the immune system. Reverse transcription (RT)-polymerase chain reaction (PCR) allowed the detection of galanin, GalR1 and GalR3 mRNAs in the thymus cortex of immature (20-day-old) rats, while GalR2 expression was very weak or absent. Immature rats were given three subcutaneous injections (28, 16 and 4 h before sacrifice) of 2 nmol/100 g galanin and or the galanin-receptor antagonist (galanin-A) [D-Thr(6),D-Trp(8,9),15-ol]-galanin(1-15), and 0.1 mg/100 g vincristine 3 h before sacrifice. Thymuses were processed for light microscopy and the percentage of metaphase-arrested cells (mitotic index) was evaluated. Galanin-A increased the thymus mitotic index, while galanin was ineffective, thereby suggesting that endogenous galanin exerts a maximal tonic inhibitory effect on the proliferative activity of thymocytes in immature rats. Immature rat thymocytes were cultured in vitro for 12 h in the presence of 10(-6) M galanin and/or galanin-A. Hoechst 33342 and propidium iodide were added to the cultures, and the percentage of apoptotic and necrotic cells was determined under fluorescence microscope. Galanin increased apoptotic index, and the effect was prevented by galanin-A. Neither galanin nor galanin-A altered necrotic index. Collectively, our findings indicate that galanin, probably acting through GalR1 and GalR3, exerts antiproliferative and proapoptotic effects on immature rat thymocytes, which makes it likely that this peptide plays a role in the autocrine/paracrine functional regulation of immune system in the rat.

Localization of human chorionic gonadotropin beta subunit transcripts in ovarian cancer tissue.

Recent studies demonstrated that besides placenta and malignant trophoblastic tumors, hCG and especially its beta-subunit is secreted by a varieties of tumors of different origin. The aim of the present investigation was to determine the expression pattern of human chorionic gonadotropin gene in ovarian cancer tissue. The study included 8 patients with epithelial ovarian carcinoma. The expression and distribution of hCGbeta mRNA was assessed by in situ RT-PCR method. The semi-quantitative assessment was performed using computer image analysis. Transformation of the images into the pseudocolour scale showed a clear difference in fluorescence intensity among individual cancer cells. The intensity of ISRT-PCR products corresponding with expression level of hCGbeta demonstrated that its production by individual cancer cells is different. In all studied specimens of the ovarian carcinoma tissue, cancer cells characterized by the presence of active hCGbeta gene were found, whereas noncancerous tissue demonstrated lack of the gene expression. Thus, the study clearly shows that the expression of hCGbeta is the feature of ovarian cancer tissue.

Effects of treatment with somatostatin analogues on the occurrence of apoptosis in somatotropinomas.

OBJECTIVES: Apoptosis of endocrine cells represents one of factors significantly affected the control of hormones secretion. Present study aimed to examine whether treatment of somatotropinoma types tumours with somatostatine analogue (lanreotide) results in apoptosis. MATERIAL AND METHODS: The studies were performed on 35 patients with somatotropinoma type tumours on whom adenomectomy was performed by transsphenoidal approach. The operative material was examined by cellular morphology, based on light and electron microscopy and chromosomal ladder formation assay. RESULTS: The number of apoptotic cells showed features typical for the process as condensation and fragmentation of chromatin, vacuolisation, damage of the inner structure of mitochondria and oligonucleosomal fragmentation of DNA was found in the study material. The results of the studies demonstrated the occurrence of lanreotide induced apoptosis in somatotropinoma type tumours. The grade of apoptotic cells in macroadenomas type adenomas, treated with lanreotide, ranged from 4.0% to 17.1% (mean 8.7+/-2.6%). Patients in whom hypophysectomy was not preceded by lanreotide treatment demonstrated low level of apoptotic cells (no more than 3.5%). CONCLUSIONS: The studies showed that treatment with somatostatine analogue-lanreotide induced apoptosis of tumour cell suggesting that the induction of apoptotic cell death may be involved in the anticancer activity of somatostatine analogue.

[Image cytometry appliance in chronic tonsillitis]. / Wykorzystanie cytometrii obrazowej w diagnostyce przewleklego zapalenia migdalków podniebiennych.

Enlargement of palatinar tonsils in the course of chronic inflammatory process has been thought till now to reflect pronounced lymphocyte proliferation even if such mechanism fails to explain the persistent increase in size of the organ. The studies were performed on 92 tonsils obtained from 4 to 16 years old children in whom the tonsils were removed due to chronic inflammatory processes in upper respiratory tract or in ears. Cell proliferation and apoptosis were evaluated by flow cytometry and by image analysis. The data show that apoptosis in the tonsils is accompanying lymphocyte proliferation in the course of chronic inflammatory process. Evaluation of homeostasis in palatine tonsils could be helpful in referring children for tonsillectomy. Imagine analysis may objectivize and specify diagnosis of chronic tonsillitis.

Rod outer segment membrane guanylate cyclase type 1 (ROS-GC1) calcium-modulated transduction system in the sperm.

OBJECTIVE: Evaluation of the presence of a Ca(2+)-regulated membrane guanylate cyclase signal transudation system in the spermatozoa. DESIGN: Experimental study. SETTING: Research university laboratory. PATIENT(S): Human sperm obtained from healthy donors who met the criteria of the World Health Organization for normozoospermia and bovine semen collected from bulls of proven fertility. INTERVENTION(S): Radioimmunoassay and immunohistochemistry of human and bovine spermatozoa. MAIN OUTCOME MEASURE(S): The membrane guanylate cyclase activity and the presence of membrane guanylate cyclase transduction machinery components in the spermatozoa. RESULT(S): The identity of a Ca(2+)-modulated membrane guanylate cyclase transduction machinery in human and bovine spermatozoa has been documented. The machinery is both inhibited and stimulated within nanomolar to semimicromolar range of free Ca(2+). The transduction component of this machinery is the rod outer segment membrane guanylate cyclase type 1 (ROS-GC1). The enzyme coexists with three Ca(2+)-dependent modulators: guanylate cyclase activating protein type 1 (GCAP1), S100B and neurocalcin delta. ROS-GC1 and its modulators are present in the heads and tails of both species' spermatozoa. CONCLUSION(S): The coexpression of ROS-GC1 and its activators in spermatozoa suggests that the Ca(2+)-modulated ROS-GC1 transduction system may be a part of the fertilization machinery.

Trichrome Mallory's stain may indicate differential rates of RNA synthesis in eutopic and ectopic endometrium.

Mallory's triple staining is a histochemical technique used mainly for analysing connective tissues and glands and other tissues. We have described the differences in the nuclear staining between eutopic and ectopic endometrium as well as endometrial hyperplasia and adenocarcinoma using the Mallory's method. The ultrastructural differences between eutopic and ectopic endometrium have been detected. In normal and hyperplastic endometrium the presence of stromal cell nuclei with an increased affinity to aniline blue has been observed. The affinity has disappeared after digestion of tissues with RNase. In cases of endometriosis, independently of cell types, the nuclei have shown affinity to orange G. Similar effects in adenocarcinoma have been noted. The ultrastructural studies have shown that in normal endometrium the stroma contained cells with euchromatic and low electron density cell nuclei. In endometriosis heterochromatic cell nuclei present both in the stroma and within glands have been detected. The results indicate that the Mallory's technique may be a useful tool for recognizing the differences between eutopic and ectopic endometrium. The affinity for aniline blue in normal and hyperplastic endometrium occurs most likely due to increased RNA synthesis. Based on Mallory's staining a similarity between hyperplasia and unchanged endometrium in contrast to similar results of the staining obtained in cases of adenocarcinoma and endometriosis may be suggested.