Morphology of mitochondrial nucleoids in respiratory-deficient yeast cells varies depending on the unit length of the mitochondrial DNA sequence

We investigated the morphology of mitochondrial nucleoids (mt-nucleoids) and mitochondria in Saccharomyces cerevisiae rho(+) and rho(-) cells with DAPI staining and mitochondria-targeted GFP. Whereas the mt-nucleoids appeared as strings of beads in wild-type rho(+) cells at log phase, the mt-nucleoids in hypersuppressive rho(-) cells (HS40 rho(-) cells) appeared as distinct punctate structures. In order to elucidate whether the punctate mt-nucleoids are common to other rho(-) cells, we observed the mt-nucleoids in rho(-) strains that retain different unit lengths of the mitochondrial DNA (mtDNA) sequence. As a result, rho(-) cells that have long mtDNA sequences, of more than 30 kb, had mt-nucleoids with a strings-of-beads appearance in tubular mitochondria. In contrast, rho(-) cells that have short mtDNA sequences, of <1 kb, had punctate mt-nucleoids in tubular mitochondria. This indicates that the morphology of mt-nucleoids in rho(-) cells significantly varies depending on the unit length of their mtDNA sequence. Analyses of mt-nucleoids suggest that the punctate mt-nucleoids in HS40 rho(-) cells consist of concatemeric mtDNAs and oligomeric circular mtDNAs associated with Abf2p and other nucleoid proteins.

Tellurium as a valuable tool for studying the prokaryotic origins of mitochondria

Mitochondria are eukaryotic organelles which contain the own genetic material and evolved from free-living Eubacteria, namely hydrogen-producing Alphaproteobacteria. Since 1965, biologists provided, by research at molecular level, evidence for the prokaryotic origins of mitochondria. However, determining the precise origins of mitochondria is challenging due to inherent difficulties in phylogenetically reconstructing ancient evolutionary events. The use of new tools to evidence the prokaryotic origin of mitochondria could be useful to gain an insight into the bacterial endosymbiotic event that resulted in the permanent acquisition of bacteria, from the ancestral cell, that through time were transformed into mitochondria. Electron microscopy has shown that both proteobacterial and yeast cells during their growth in the presence of increasing amount of tellurite resulted in dose-dependent blackening of the culture due to elemental tellurium (Te(0)) that formed large deposits either along the proteobacterial membrane or along the yeast cell wall and mitochondria. Since the mitochondrial inner membrane composition is similar to that of proteobacterial membrane, in the present work we evidenced the black tellurium deposits on both, cell wall and mitochondria of ρ(+) and respiratory deficient ρ(-) mutants of yeast. A possible role of tellurite in studying the evolutionary origins of mitochondria will be discussed.

Aldehyde dehydrogenase, Ald4p, is a major component of mitochondrial fluorescent inclusion bodies in the yeast Saccharomyces cerevisiae

When Saccharomyces cerevisiae strain 3626 was cultured to the stationary phase in a medium that contained glucose, needle-like structures that emitted autofluorescence were observed in almost all cells by fluorescence microscopy under UV excitation. The needle-like structures completely overlapped with the profile of straight elongated mitochondria. Therefore, these structures were designated as mitochondrial fluorescent inclusion bodies (MFIBs). The MFIB-enriched mitochondrial fractions were successfully isolated and 2D-gel electrophoresis revealed that a protein of 54 kDa was only highly concentrated in the fractions. Determination of the N-terminal amino acid sequence of the 54-kDa protein identified it as a mitochondrial aldehyde dehydrogenase, Ald4p. Immunofluorescence microscopy showed that anti-Ald4p antibody specifically stained MFIBs. Freeze-substitution electron microscopy demonstrated that cells that retained MFIBs had electron-dense filamentous structures with a diameter of 10 nm in straight elongated mitochondria. Immunoelectron microscopy showed that Ald4p was localized to the electron-dense filamentous structures in mitochondria. These results together showed that a major component of MFIBs is Ald4p. In addition, we demonstrate that MFIBs are common features that appear in mitochondria of many species of yeast.

Morphology of mitochondrial nucleoids, mitochondria, and nuclei during meiosis and sporulation of the yeast Saccharomycodes ludwigii

The morphology of mitochondrial nucleoids (mt-nucleoids), mitochondria, and nuclei was investigated during meiosis and sporulation of the diploid cells of the ascosporogenic yeast Saccharomycodes ludwigii. The mt-nucleoids appeared as discrete dots uniformly distributed in stationary-phase cells as revealed by 4',6-diamidino-2-phenylindole (DAPI) staining. Throughout first and second meiotic divisions, the mt-nucleoids moved to be located close to the dividing nuclei with the appearance of dots. On the other hand, mitochondria, which had tubular or fragmented forms in stationary-phase cells, increasingly fused with each other to form elongated mitochondria during meiotic prophase as revealed by 3,3' -dihexyloxacarbocyanine iodide [DiOC(6)(3)] staining. Mitochondria assembled to be located close to dividing nuclei during first and second meiotic divisions, and were finally incorporated into spores. During the first meiotic division, nuclear division occurred in any direction parallel, diagonally, or perpendicular to the longitudinal axis of the cell. In contrast, the second meiotic division was exclusively parallel to the longitudinal axis of the cell. The behavior of dividing nuclei explains the formation of a pair of spores with opposite mating types at both ends of cells. In the course of this study, it was also found that ledges between two spores were specifically stained with DiOC(6)(3).

A simple method for culture and stable maintenance of giant spheroplasts from the yeast Saccharomyces cerevisiae

When spheroplasts of the yeast Saccharomyces cerevisiae are cultured in liquid medium containing osmotic stabilizer, they undergo nuclear division and growth without cell division, resulting in the formation of giant spheroplasts with multinuclei. In this study, we report a simple method for the culture and stable maintenance of giant spheroplasts. The selection of culture media and cell concentration was found to be important for the growth and maintenance of giant spheroplasts. Among the conditions that we tested, static culture in a synthetic Burkholder's medium in 96-well U-bottomed culture plates was most effective. Under appropriate conditions, we could maintain giant spheroplasts for more than 6 days without proliferation of whole cells or marked lysis. The average diameter of spheroplasts can vary from 16 to 53µm, depending on their initial concentration.

Morphology and protein composition of the mitochondrial nucleoids in yeast cells lacking Abf2p, a high mobility group protein

To elucidate the role of Abf2p, a major mitochondrial DNA-binding protein in the yeast Saccharomyces cerevisiae, we examined the morphology of the mitochondrial nucleoids (mt-nucleoids) in an ABF2-deficient mutant (Δabf2) in vivo and in vitro by 4',6-diamidino-2-phenylindole (DAPI) staining. The mt-nucleoids appeared as diffuse structures with irregular-size in Δabf2 cells that were grown to log phase in YPG medium containing glycerol, in contrast to the strings-of-beads appearance of mt-nucleoids in wild-type cells. In addition, DAPI-fluorescence intensity of the mt-nucleoids transmitted to the bud was significantly lower in Δabf2 cells than in wild-type cells at log phase. However, the lack of Abf2p did not affect the morphology or segregation of mitochondria. The protein composition of the mt-nucleoids isolated from Δabf2 cells grown to stationary phase in YPG medium was very similar to that of the mt-nucleoids isolated from wild-type cells cultured under the same conditions, except for the lack of Abf2p. These results together suggested that in log-phase cells, the lack of Abf2p influences not only the morphology of mt-nucleoids but also their transmission into the bud. On the other hand, our result suggested that in stationary-phase cells, the lack of Abf2p does not significantly alter the protein composition of the mt-nucleoids.

Bismuth heterocycles based on a diphenyl sulfone scaffold: synthesis and substituent effect on the antifungal activity against Saccharomyces cerevisiae

A series of heterocyclic organobismuth(III) compounds 2 [ClBi(5-R-C6H(3)-2-SO2C6H(4)-1'-): R=Me, Ph, MeO, Cl, H, t-Bu, CF3, F, Me2N] was synthesized in order to study the relative importance of structure and specific substitutions in relation to their lipophilicity and antifungal activity against the yeast Saccharomyces cerevisiae. A clear structure-activity relationship between the size of the inhibition zone and the value of ClogP was found for 2. These results suggest that the higher the lipophilicity, the lower the antifungal activity. Thus, 2e (R=H) and 2h (R=F), which had ClogP values of 1.18 and 1.45, respectively, were most active. In contrast, 2b (R=Ph) and 2f (R=t-Bu) had ClogP values of 3.06 and 3.00, respectively, and exhibited no antifungal activity. Compound 6b ClBi[5-(OH)C6H(3)-2-SO(2)-5'-(OH)C6H(3)-1'-] had an estimated ClogP value of 0.81 but exhibited only low activity in spite of its low ClogP value, suggesting that such a considerable decrease in lipophilicity lowers inhibition activity. Bismuth carboxylate 7b derived from p-nitrobenzoic acid and 2e exhibited inhibition activity comparable to those of 2e and 2h despite its higher lipophilicity (ClogP=2.68).

Mitochondrial nucleoids from the yeast Candida parapsilosis: expansion of the repertoire of proteins associated with mitochondrial DNA

Molecules of mitochondrial DNA (mtDNA) are packed into nucleic acid-protein complexes termed mitochondrial nucleoids (mt-nucleoids). In this study, we analysed mt-nucleoids of the yeast Candida parapsilosis, which harbours a linear form of the mitochondrial genome. To identify conserved as well as specific features of mt-nucleoids in this species, we employed two strategies for analysis of their components. First, we investigated the protein composition of mt-nucleoids isolated from C. parapsilosis mitochondria, determined N-terminal amino acid sequences of 14 proteins associated with the mt-nucleoids and identified corresponding genes. Next, we complemented the list of mt-nucleoid components with additional candidates identified in the complete genome sequence of C. parapsilosis as homologues of Saccharomyces cerevisiae mt-nucleoid proteins. Our approach revealed several known mt-nucleoid proteins as well as additional components that expand the repertoire of proteins associated with these cytological structures. In particular, we identified and purified the protein Gcf1, which is abundant in the mt-nucleoids and exhibits structural features in common with the mtDNA packaging protein Abf2 from S. cerevisiae. We demonstrate that Gcf1p co-localizes with mtDNA, has DNA-binding activity in vitro, and is able to stabilize mtDNA in the S. cerevisiae Deltaabf2 mutant, all of which points to a role in the maintenance of the C. parapsilosis mitochondrial genome. Importantly, in contrast to Abf2p, in silico analysis of Gcf1p predicted the presence of a coiled-coil domain and a single high-mobility group (HMG) box, suggesting that it represents a novel type of mitochondrial HMG protein.

Use of the nuc1 null mutant for analysis of yeast mitochondrial nucleoids

Mitochondrial DNA (mtDNA) of the yeast Saccharomyces cerevisiae is organized to form mitochondrial nucleoids (mt-nucleoids) by association with specific proteins. The sensitivity of DNA-protein complexes to nuclease digestion is a useful means for examining DNA packaging and organization. However, the mt-nucleoids isolated from wild-type cells of S. cerevisiae demonstrated a significant amount of endogenous nuclease activity. In order to minimize the nuclease activity associated with the isolated mt-nucleoids, we isolated the mt-nucleoids from a mutant strain that lacked the mitochondrial nuclease, Nuc1p. In this manner, we succeeded in isolating mt-nucleoids that showed a low level of the nuclease activity. Micrococcal nuclease treatment of these mt-nucleoids led to the continuous digestion of mtDNA in the presence of Ca(2+) ions. MtDNA in the mt-nucleoids also showed the continuous digestion pattern when treated with DNase II. These results suggest that mtDNA in the mt-nucleoids is protected from nuclease digestion by association with proteins, but the organization of the mtDNA-protein complexes is different from that of nuclear chromatin, in which the unit of DNA packaging is regularly repeated.

Purification of an Abf2p-like protein from mitochondrial nucleoids of yeast Pichia jadinii and its role in the packaging of mitochondrial DNA

A 26-kDa protein with highly basic pI was purified from the mitochondrial (mt-) nucleoids of the yeast Pichia jadinii by a combination of acid extraction, hydroxyapatite chromatography and DNA-cellulose chromatography. The 26-kDa protein has the ability to introduce a supercoil into circular plasmid DNA in the presence of topoisomerase I and to package mtDNA into nucleoid-like aggregates. The mt-nucleoids isolated from P. jadinii cells were disassembled in the presence of 2 M NaCl and reassembled into nucleoid-like aggregates by the removal of the salts. During the course of the reassembly of the mt-nucleoids, three specific proteins of 20 kDa, 26 kDa and 56 kDa predominantly precipitated after the centrifugation of the reassembled mt-nucleoids. These results suggest that the 26-kDa protein of P. jadinii has a similar function in the packaging of mtDNA to Abf2p, a major mitochondrial DNA-binding protein in Saccharomyces cerevisiae.

Mitochondrial chromosome structure: an insight from analysis of complete yeast genomes

Recent progress in the analysis of protein components of the mitochondrial nucleoid and replisome of baker's yeast, Saccharomyces cerevisiae, opens a unique opportunity for understanding the molecular principles of mitochondrial inheritance. In this work we identified homologs of proteins involved in the mitochondrial DNA packaging and replication in the complete genome sequence of the petite-negative yeast Kluyveromyces lactis. Comparative analysis of their counterparts from phylogenetically diverse yeast species revealed conserved as well as diverged features of the organellar chromosome structure and its replication strategy. Moreover, it provides a basis for subsequent functional studies of the structure and dynamics of the mitochondrial nucleoids.

Gastrointestinal stromal tumor arising in the rectovaginal septum

We report herein a rare case of malignant gastrointestinal stromal tumor (GIST) originated from the rectal wall, which presented as a tumor on the rectovaginal septum. A 54-year-old Japanese woman, gravida 4, para 3, was admitted complaining of anuresis and severe constipation. She had a history of hysterectomy and right salpingo-oophorectomy for uterine leiomyoma 11 years previously. Pelvic examination revealed an 8.5 x 7.5 x 7.5 cm hard mass in the rectovaginal space. The inferior border of the tumor was 2 cm from the vaginal introitus and 2 cm from the anus. Computed tomography and magnetic resonance imaging showed a well-circumscribed soft-tissue mass filling the rectovaginal space. Urinary bladder and rectum were markedly compressed and displaced. Colon fiberscopy revealed invasion of the tumor into the rectal mucosa. An abdominoperineal resection of the rectum with posterior vaginal wall resection and pelvic lymphadenectomy was performed. The resected specimen showed a rectal submucosal tumor that was 8 x 8 x 7 cm in size. The tumor was diagnosed as a malignant GIST. Immunohistochemical analysis confirmed this diagnosis. The patient is now healthy without evidence of recurrence at 13 months after surgery. Gynecologists should be aware of rectal GIST arising in the rectovaginal space as a differential diagnosis of vaginal submucosal tumor.

A 22 kDa protein specific for yeast mitochondrial nucleoids is an unidentified putative ribosomal protein encoded in open reading frame YGL068W

Mitochondrial-nucleoid (mt-nucleoid) proteins of the yeast Saccharomyces cerevisiae were separated by two-dimensional gel electrophoresis. Analysis of the N-terminal amino acid sequence showed that a 22 kDa protein which is unique in the mt-nucleoid fraction is an unidentified protein encoded in the open reading frame YGL068W and shows a homology with the ribosomal protein L7/L12 of bacteria. We named this protein Mnp1p (for the mitochondrial-nucleoid protein 1). Immunoblotting of each fraction with an anti-Mnp1p antibody during the mt-nucleoid isolation showed that Mnp1p is highly concentrated in the mt-nucleoid fraction. Immunofluorescence microscopy suggested that Mnp1p is localized to mitochondria in vivo, and a significant amount of Mnp1p is associated with the mt-nucleoids. On the other hand, Northern blotting showed that a large amount of large and small mitochondrial ribosomal RNAs was not associated with the mt-nucleoids and remained in the supernatant after the isolation of mt-nucleoids. The null mutation of MNP1 led to a respiratory-deficient phenotype, but the morphology of the mt-nucleoids in the transformants carrying the null mutation was normal. These results suggest that a significant amount of Mnp1p plays a role as a major component of the mt-nucleoids.

Scanning electron microscopy of endometriotic lesions in the pelvic peritoneum and the histogenesis of endometriosis

OBJECTIVE

To determine whether the epithelium of an endometriotic lesion has eutopic endometrial glandular epithelium morphology or not for the histogenesis of endometriosis.

METHOD

Scanning electron microscopy (SEM) of the endometrium was done for 25 cases. Histologically proven endometriotic lesions of 10 of these 25 cases were processed for SEM. Peroneum samples of another 15 cases without histological endometriosis were also studied.

RESULT

Three of 10 cases with histologically proven endometriotic lesions revealed endometrium-like morphology by SEM, whereas normal appearing peritoneum without histological endometriosis in 15 cases showed no endometrium-like structures by SEM.

CONCLUSION

Although abovementioned results did not support retrograde menstruation and implantation, they suggested a possibility of derivation from the endometrium.

Antifungal activity of organobismuth compounds against the yeast Saccharomyces cerevisiae: structure–activity relationship

Antifungal activity of organobismuth(III) and (V) compounds 1-9 was examined against the yeast, Saccharomyces cerevisiae. A clear structure-activity relationship was observed in these compounds. Thus, triarylbismuth dichlorides 2 [(4-YC6H4)3BiCl2: Y=MeO, F, Cl, CF3, CN, NO2] and halobismuthanes 6 [2-(t)BuSO2C6H4(4-YC6H4)BiX: Y=MeO, Me, H, Cl; X=Cl, Br, I], 7 [Bi(X)(C6H4-2-SO2C6H4-1'-): X=Cl, Br, I], 8 [2-Me2NCH2C6H4(Ph)BiX: X=Cl, Br] and 9 [4-MeC6H4(8-Me2NC10H6-1-)BiCl] showed the growth inhibition effect, while triarylbismuth difluorides 3 [(4-YC6H4)3BiF2] and triarylbismuthanes 1 [(4-YC6H4)3Bi], 4 [2-(t)BuSO2C6H4(4-YC6H4)2Bi] and 5 [4-YC6H4Bi(C6H4-2-SO2C6H4-1'-)] were not active at all irrespective of the nature of the substituents. Generation of the inhibition effect is governed by the facility of nucleophilic reaction at the bismuth center and the Lewis acidic bismuth center is an active site. Of all the bismuth compounds attempted, halobismuthanes 7 derived from diphenyl sulfone exhibited the highest activities. An X-ray crystallographic study of 7a [Bi(Cl)(C6H4-2-SO2C6H4-1'-)] revealed that the bismuth center adopts a seven-coordinated geometry, which is unusual in organobismuth(III) compounds, through the intramolecular and intermolecular coordination between the bismuth and oxygen atoms. The marked inhibition effect of 7 may be attributed to such a highly coordinated geometry, which allows the bismuth center to bind tightly with some biomolecules playing important roles in the growth of S. cerevisiae.

Gastrointestinal stromal tumor arising in the rectovaginal septum

We report herein a rare case of malignant gastrointestinal stromal tumor (GIST) originated from the rectal wall, which presented as a tumor on the rectovaginal septum.

A 54-year-old Japanese woman, gravida 4, para 3, was admitted complaining of anuresis and severe constipation. She had a history of hysterectomy and right salpingo-oophorectomy for uterine leiomyoma 11 years previously. Pelvic examination revealed an 8.5 × 7.5 × 7.5 cm hard mass in the rectovaginal space. The inferior border of the tumor was 2 cm from the vaginal introitus and 2 cm from the anus. Computed tomography and magnetic resonance imaging showed a well-circumscribed soft-tissue mass filling the rectovaginal space. Urinary bladder and rectum were markedly compressed and displaced. Colon fiberscopy revealed invasion of the tumor into the rectal mucosa. An abdominoperineal resection of the rectum with posterior vaginal wall resection and pelvic lymphadenectomy was performed. The resected specimen showed a rectal submucosal tumor that was 8 × 8 × 7 cm in size. The tumor was diagnosed as a malignant GIST. Immunohistochemical analysis confirmed this diagnosis. The patient is now healthy without evidence of recurrence at 13 months after surgery.

Gynecologists should be aware of rectal GIST arising in the rectovaginal space as a differential diagnosis of vaginal submucosal tumor.

The clinical role of interleukin-6 and interleukin-6 soluble receptor in human follicular fluids

In order to investigate the role of interleukin-6 (IL-6) and interleukin-6 soluble receptor (sR) in human ovulation, we evaluated the concentrations in human follicular fluid and analyzed the correlation of IL-6 and IL-6 sR with oocyte maturation. The oocytes were obtained from the follicular fluid of 45 women undergoing in vitro fertilization and embryo transfer. The concentrations of IL-6 and IL-6 sR in follicular fluid were measured by ELISA. In addition, granulosa cells obtained from the follicular fluid were cultured and treated with forskolin and 12- o-tetradecanoylphorbol 13-acetate for 24-48 h. The concentration of IL-6 was significantly higher in the follicular fluid than in the serum (P<0.01). In contrast, the concentration of IL-6 sR was significantly lower in the follicular fluid than in the serum (P<0.001). The concentrations of IL-6 and IL-6 sR were significantly higher in the follicular fluid containing mature oocytes than in fluid containing immature oocytes (P<0.05). The production of IL-6 was markedly increased over the basal level after 24 h of treatment with forskolin (P<0.001) and 48 h of treatment (P<0.01) with cultured granulosa cells. Our data suggest that IL-6 and IL-6 sR may play an important role in follicular growth and development in human preovulatory processes. It is possible that IL-6 in particular may be regulated by cAMP. IL-6 and IL-6 sR might also be valuable biochemical markers in the evaluation of oocyte maturation.

Isolation of the mitochondrial nucleoids from yeast Kluyveromyces lactis and analyses of the nucleoid proteins

Mitochondrial (mt) nucleoids were isolated from yeast Kluyveromyces lactis with morphological intactness. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) revealed more than 20 proteins that are associated with the mt-nucleoids. However, the protein profile of the mt-nucleoids of K. lactis was significantly different from that of the mt-nucleoid proteins from Saccharomyces cerevisiae. SDS-DNA PAGE, which detected an Abf2p, a major mitochondrial DNA-binding protein, among the mt-nucleoid proteins of S. cerevisiae on a gel, detected only a 17-kDa protein in the K. lactis mt-nucleoid proteins. The 17-kDa protein was purified as homogeneous from the mt-nucleoids by a combination of acid extraction, hydroxyapatite chromatography and DNA-cellulose chromatography. The 17-kDa protein introduced a negative supercoil into circular plasmid DNA in the presence of topoisomerase I, as does S. cerevisiae Abf2p, and it packed K. lactis mtDNA into nucleoid-like particles in vitro. These results, together with the determination of the N-terminal amino acid sequence, suggested that the 17-kDa protein is an Abf2p homologue of K. lactis and plays structural roles in compacting mtDNA in cooperation with other nucleoid proteins.

Complete response to radiation therapy in a patient with chemotherapy-resistant ovarian clear cell adenocarcinoma

Recurrent ovarian cancer after front-line chemotherapy is incurable. In most institutions, chemotherapy is continued as salvage therapy after primary chemotherapy failure and despite the fact that long-term survival and complete responses are infrequent. Radiation therapy for patients with recurrent ovarian cancer has often been done with palliative intent. A patient with ovarian clear cell adenocarcinoma received irradiation with palliative intent to the whole pelvis after chemotherapy (paclitaxel, carboplatin, and irinotecan) produced no effect. Although she developed a rectovaginal fistula due to cancer invasion during radiation therapy. One year and half after the therapy, she is still alive with no evidence of disease. In an effort to maximize salvage potential and quality of life while minimizing toxicity, selected patients with ovarian cancer should be treated with radiation therapy directed to residual or recurrent sites.

The effect of epidermal growth factor on vascular endothelial growth factor secretion by endometrial stromal cells

Endometrial stromal cells undergo morphological and functional changes to facilitate oocyte implantation under regulation of various hormones and growth factors. We studied physiological induction by epidermal growth factor (EGF) of vascular endothelial growth factor (VEGF) in these cells. In human endometrial stromal cells, the effect of EGF, genistein, tryphostin AG1478 (a tyrosine kinase inhibitor), and wortmannin (a phosphatidylinositol 3-kinase inhibitor) on production of VEGF was examined. Total RNA was extracted and VEGF mRNA expression was quantified by Northern analysis. EGF induced production of VEGF by stromal cells in a time-dependent manner; the effect became significant after 12 h and increased further between 24 and 48 h (P<0.05). Dose dependency was also significant (P<0.01). Genistein, tryphostin AG1478, and wortmannin partially suppressed the increase in production induced by EGF (P<0.01, P<0.01, P<0.01), respectively. Production of EGF by fertilized oocytes and trophoblasts has been reported in early pregnancy. VEGF is believed to be induced by EGF through mechanisms involving tyrosine kinase and phosphatidylinositol 3-kinase. The increase in VEGF may contribute to neovascularization that promotes proliferation of endometrium and placentation.

c-Ets1 is a promising marker in epithelial ovarian cancer

c-Ets1 controls the expression of some genes involved in extracellular matrix remodeling. To elucidate the involvement of c-Ets1 in epithelial ovarian carcinogenesis, we investigated the role of the proto-oncogene c-ets1 in the regulation of physiological processes such as cell proliferation, differentiation, and tumor invasion. Using fluorescent immunohistochemistry, we analyzed serial frozen sections for c-Ets1 protein expression in 26 patients with ovarian epithelial carcinoma, 10 patients with benign cystadenoma of the ovary, and 10 premenopausal patients with normal ovaries. We analyzed the relationship between the percentage of c-Ets1 stained cells in a patient and characteristics of the patient including histological classification, clinical stage, histological grade, and clinical outcome. c-Ets1 was not detected in any cases of benign ovarian cystadenoma. Most of the c-Ets1 proteins were found in the cytoplasm and some in the nucleus of epithelial ovarian cancer tissues. Moreover, c-Ets1 was strongly expressed in the head portion of papillary cancer tissues that had invaded the stroma. c-Ets1 expression was significantly associated with clinical stage (p<0.01), histological grade (p<0.01), and clinical outcome (p<0.01). Survival data were available for all patients and univariate Cox regression analysis showed that c-Ets1 expression was significantly associated with a poor prognosis (p<0.05). Our results demonstrate that c-Ets1 expression in epithelial ovarian cancer correlates to the malignant potential of the tumor.

Identification of the YMN-1 antigen protein and biochemical analyses of protein components in the mitochondrial nucleoid fraction of the yeast Saccharomyces cerevisiae

We analyzed the protein components contained in the mitochondrial nucleoid (mt-nucleoid) fraction of the yeast Saccharomyces cerevisiae. Immunoblotting with anti-Abf2p antibody demonstrated the association of Abf2p, a major mitochondrial DNA-binding protein, with the mt-nucleoids. In contrast, porin and cytochrome c oxidase subunit III (CoxIIIp) were not detected by immunoblotting in the mt-nucleoid fraction. The YMN-1 monoclonal antibody recognized a 48 kDa protein of the mt-nucleoid fraction. The N-terminal amino acid sequence of the protein and immunological evidence showed that the YMN-1 monoclonal antibody recognizes dihydrolipoyl transsuccinylase (KE2), which is one of the constituents of the alpha-ketoglutarate dehydrogenase complex (KGDC). alpha-Ketoglutarate dehydrogenase (KE1) and dihydrolipoyl dehydrogenase (E3), which are other subunits of KGDC, were also detected in the mt-nucleoid fraction. An enzyme assay of the mt-nucleoid fraction showed that cytochrome c oxidase and fumarase activity were barely detected in the fraction, but the specific activity of KGDC in the mt-nucleoid fraction was relatively high and was approximately 60% of the specific activity in the mitochondrial fraction. Three components of KGDC were detected in the DNA-binding protein fractions after DNA-cellulose column chromatography of mt-nucleoid proteins. These results suggested that a part of KGDC in the mitochondrial matrix is associated with mt-nucleoids in vivo.

Synergistic effect of interleukin-1alpha and ceramide analogue on production of prostaglandin E2 and F2alpha by endometrial stromal cells

PROBLEM

Prostaglandins (PGs) are synthesized in the endometrium. Our objective was to evaluate interleukin (IL)-1alpha-induced production of PGE2 and PGF2alpha in endometrial stromal cells (ESC) following treatment with ceramide analogues.

METHODS OF STUDY

ESC were obtained from human uterine endometrium by enzymic digestion and filtration. ESC were treated with IL-1alpha, IL-1 receptor antagonist (ra), C2-ceramide and C6-ceramide. The concentrations of PGE2 and PGF2alpha in media were determined using ELISA. The induction of prostaglandin H synthase (PGHS)-2 mRNA was also ascertained by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The production of PGE2 and PGF2alpha was significantly increased by IL-lalpha and suppressed by IL-1 ra, in a dose-dependent manner. PGF2alpha production was further increased by treatment with the combination of IL-1alpha and C2-ceramide as compared with IL-1alpha treatment alone. There was no significant difference in PGE2 production between cells treated with IL-1alpha and C2-ceramide and those treated with IL-1alpha alone. Both PGE2 and PGF2alpha production were significantly increased by treatment with IL-1alpha and C6-ceramide as compared with IL-1alpha treatment alone. Treatment of ESC with IL-1alpha stimulated PGHS-2 mRNA. PGHS-2 mRNA was decreased when IL-1 ra was added to the IL-1alpha-stimulated cells.

CONCLUSIONS

These results suggest that IL-1alpha stimulates the production of PGE2 and PGF2alpha by a mechanism that involves the sphingomyelin-ceramide system, and thus that ceramide may be important in increasing the production of PGE2 and PGF2alpha in the human 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.

The effect of dexamethasone on expression of mitogen-induced cyclooxygenase-2 mRNA by amnion-derived (WISH) cells

OBJECTIVES

It has been reported that prostaglandin E(2) (PGE(2)) is synthesized in the amnion and that this synthesis increases during labor. The purpose of this study was to clarify the mechanism for the expression of cyclooxygenase-2 (COX-2) mRNA and the PGE(2) synthesis of amnion-derived (WISH) cells.

STUDY DESIGN

Cells were cultured and treated by 12-O-tetradecanoylphorbol-13-acetate (TPA) and dexamethasone (DEX). PGE(2) in the culture medium was measured by ELISA. Total RNA was extracted from the cells, and COX-2 mRNA expression was analyzed by Northern blot analysis.

RESULTS

During the time course of PGE(2) production in response to TPA stimulation, the PGE(2) production could not be detected until incubation had continued for 2h, but this production appeared to continue after 4h of incubation. PGE(2) production was significantly increased by TPA and suppressed by treatment with TPA and DEX. During the time course of COX-2 mRNA expression in response to treatment with TPA, the COX-2 mRNA band was detected after 1.5h. The strongest expression of COX-2 mRNA was observed at 2h incubation. After pre-treatment with TPA for 1h, the TPA-induced COX-2 mRNA was suppressed by treatment with DEX for 1 or 2h incubation in a dose-dependent manner.

CONCLUSIONS

These results suggest that COX-2 mRNA is induced by TPA which activate protein kinase C, and suppressed by DEX in WISH cells.

Polo-like kinase (PLK) expression in endometrial carcinoma

Polo-like kinase (PLK) is a cell cycle-regulated, cyclin-independent serine/threonine protein kinase. Recent reports have shown a critical role for PLK during tumorigenesis. To explore whether PLK plays a general role as a tumor marker of endometrial carcinomas, we examined the expression of PLK mRNA and protein in endometrial carcinomas and normal endometrium, and analyzed the relationship between PLK protein expression and malignant potential. We found that PLK mRNA was expressed in all specimens from endometrial carcinoma patients using RT-PCR methods, although some specimens from normal endometria were negative. Immunohistochemically, most of the PLK was found in the cytoplasm (around the nucleus), and partly in the nucleus of endometrial carcinoma glands and also secreted tissues from endometrial carcinoma glands. PLK was expressed at the basement membrane of carcinoma glands and partly expressed in the head portion of papillary carcinoma tissues. There was a significant correlation between percentages of PLK-positive cells and histological grade of endometrial carcinoma (P<0.0001). However, the expression of proliferating cell nuclear antigen and Ki-67 was independent of PLK expression. Moreover, we noted that PLK is strongly expressed in invading carcinoma cells. PLK expression could reflect the degree of malignancy and proliferation in endometrial carcinoma. Thus, in addition to being of diagnostic value, modulation of PLK activity in the tumors by chemotherapeutic agents or gene therapy may prove to be of therapeutic value.

The effect of pregnancy on cytochrome P4501A2, xanthine oxidase, and N-acetyltransferase activities in humans

OBJECTIVE

Our objective was to evaluate the activity of cytochrome P4501A2 (CYP1A2), xanthine oxidase (XO), and N-acetyltransferase 2 (NAT2) from early to late pregnancy and after delivery.

METHODS

Twelve women were studied on three occasions during pregnancy (early, 8-16 weeks' gestation; middle, 20-28 weeks' gestation; and late, 32-39 weeks' gestation) and about 1 month after delivery. Caffeine was used as a metabolic probe. After the women ingested a can or a bottle of caffeine-containing soft drink, urine samples were collected for 12 hours. The caffeine metabolites measured were 5-acetylamino-6-amino-3-methyluracil (AAMU), 1-methylxanthine (1X), 1-methyl-uric acid (1U), 1,7-dimethyl-uric acid (17U), and 1,7-dimethylxanthine (17X). The hepatic enzyme activities were estimated by the urinary caffeine metabolic ratios as follows: CYP1A2 = (AAMU + 1X + 1U)/17U; XO = 1U/(1X + 1U); NAT2 = AAMU/(AAMU + 1X + 1U).

RESULTS

Statistically significant differences were found in CYP1A2 (P < .0001) and NAT2 (P < .01). The mean metabolic ratios for CYP1A2 during pregnancy (6.80, 5.18, and 4.97 for the early phase, middle phase, and late phase, respectively) were significantly lower than the ratio after delivery (10.39). The mean metabolic ratio for NAT2 in the early phase (0.57) was significantly lower than after delivery (0.66). There was no significant difference in metabolic ratios for XO during pregnancy and after delivery.

CONCLUSION

The data demonstrate that pregnancy influences CYP1A2 and NAT2 activity. CYP1A2 activity decreases not only in late pregnancy but also in early and middle pregnancy.

Expression and regulation of growth-regulated oncogene alpha in human endometrial stromal cells

Growth-regulated oncogene alpha (GROalpha), a potent chemoattractant for neutrophils, has previously been detected in the endometrial stromal cells (ESC) of human endometrium. In this study, the mRNA expression of GROalpha in the endometrium was evaluated by reverse transcription-polymerase chain reaction analysis, while the localization of GROalpha protein was studied by immunohistochemistry and the concentrations of GROalpha were measured using an enzyme-linked immunosorbent assay (ELISA). The effects of known modulators of endometrial function on the production of GROalpha by ESC were also examined by ELISA and Northern blot analysis. The expression of both GROalpha mRNA and GROalpha protein was detected in the cycling endometrium. GROalpha protein was localized mainly in the stroma, and endometrial tissues in the secretory phase contained higher amounts of GROalpha protein than did those in the proliferative phase. The production of GROalpha by ESC was enhanced by in-vitro decidualization. Lipopolysaccharide, tumour necrosis factor-alpha and interleukin-1beta also stimulated the expression of GROalpha mRNA and protein by ESC. These results suggest that the production of GROalpha by ESC is regulated by ovarian steroid hormones as well as by inflammatory mediators. The modulation of GROalpha concentrations in the local environment may contribute to normal and pathological processes in the uterus by regulating leukocyte trafficking in the endometrium.

Atypical polypoid adenomyoma in a patient with hyperprolactinemia

We report a case of an atypical polypoid adenomyoma in a patient with hyperprolactinemia. A 23-year-old Japanese woman was admitted complaining of atypical genital bleeding. Specula examination revealed a walnut-size polypoid mass extruding from the cervix. The patient was oligomenorrheac, and endocrine analysis showed hyperprolactinemia. Transvaginal ultrasonography and magnetic resonance imaging revealed an endometrial polypoid mass (4 x 3 x 3 cm) arising from the lower segment of the uterine corpus. The pathologic diagnosis of the tumor after polypectomy was atypical polypoid adenomyoma. It is suggested that ovarian dysfunction caused by hyperprolactinemia may be involved in the pathogenesis of atypical polypoid adenomyoma in the present case.

Effect of endotoxin-induced reactive oxygen species on sperm motility

OBJECTIVE

To define the mechanism of infection-induced damage of sperm.

DESIGN

The effect of lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) on sperm motility and its modification by scavengers were investigated.

SETTING

Research laboratory of a university hospital.

PATIENT(S)

Normozoospermic semen samples were obtained from 37 healthy volunteers.

INTERVENTION(S)

The sperms were incubated in the presence of LPS with or without scavengers.

MAIN OUTCOME MEASURE(S)

Sperm motility was evaluated by a sperm quality analyzer (SQAIIB). ROS formation in semen samples was measured by a Berthold luminometer (LB953).

RESULT(S)

Motility of spermatozoa was decreased in the LPS-treated samples compared with that in the control groups. ROS was significantly higher in the LPS-treated groups than in the control groups. The addition of ROS scavengers restored the motility index and suppressed ROS production in the LPS-treated semen samples.

CONCLUSION(S)

These data suggest that endotoxin-induced excessive production of ROS is responsible for the decrease in sperm motility and that antioxidant therapy may be a therapeutic option for infertile men with bacterial genital tract infection.

Atypical polypoid adenomyoma in a patient with hyperprolactinemia

Abstract.

Nasu K, Miyazaki T, Takai N, Miyakawa I. Atypical polypoid adenomyoma in a patient with hyperprolactinemia.

We report a case of an atypical polypoid adenomyoma in a patient with hyperprolactinemia. A 23-year-old Japanese woman was admitted complaining of atypical genital bleeding. Specula examination revealed a walnut-size polypoid mass extruding from the cervix. The patient was oligomenorrheac, and endocrine analysis showed hyperprolactinemia. Transvaginal ultrasonography and magnetic resonance imaging revealed an endometrial polypoid mass (4 × 3 × 3 cm) arising from the lower segment of the uterine corpus. The pathologic diagnosis of the tumor after polypectomy was atypical polypoid adenomyoma. It is suggested that ovarian dysfunction caused by hyperprolactinemia may be involved in the pathogenesis of atypical polypoid adenomyoma in the present case.

FTIR spectroscopic analyses of human placental membranes

We investigated the differences in the Fourier transform infrared (FTIR) spectra of normal and abnormal human placentas. Normal placentas, placentas with infant intrauterine growth restriction (IUGR), and placentas from mothers with diabetes mellitus (DM) were used, none of which had been treated before measurement. The tissues were divided into three parts: the upper one-third portion (P1), the middle portion (P2), and the lower one-third portion (P3). Placental tissues were also investigated histochemically. The differences of the main second-derivative FTIR spectra among P1, P2, and P3 in normal placentas were observed in bands appearing between 1080 and 1090 cm(-1). Bands in P2 were observed at 1083 cm(-1), which was significantly higher than that in P3 (p < 0.05). The spectrum of P2 tissue in placentas with infant IUGR had a peak at 1081 cm(-1), which was significantly different from those of P1 and P3 (p < 0.05). In placentas with DM, the P2 band was shifted to a peak at 1088 cm(-1). These data were well correlated with the histochemical sugar-chain staining pattern of the P2 portion of the placenta. Our data suggested that this IR technique is applicable to the clinical diagnosis of diseases in the gynecological field.

Expression of epithelial neutrophil-activating peptide 78 in cultured human endometrial stromal cells

It has been demonstrated that human endometrial stromal cells (ESC) produce a variety of chemokines in vivo and in vitro. To evaluate the expression of epithelial neutrophil-activating peptide 78 (ENA-78) in the endometrium, concentrations of ENA-78 in cyclic endometrial tissues were measured using enzyme-linked immunosorbent assay. The expression of ENA-78 was also detected in cyclic endometrium by immunohistochemistry. Endometrial tissues in the secretory phase contained higher amounts of ENA-78 protein than did those in the proliferative phase. Immunofluorescence staining revealed that ENA-78 protein was localized mainly in the stroma of endometrium. In addition, to evaluate the involvement of inflammatory mediators and ovarian steroid hormones in the production of ENA-78 by ESC was evaluated by in-vitro studies. Unstimulated ESC constitutively secreted ENA-78. Progesterone, lipopolysaccharide, tumour necrosis factor-alpha, and interleukin-1beta significantly stimulated the expression of ENA-78 by ESC. It is suggested that the production of ENA-78 by ESC is regulated by progesterone as well as by the inflammatory mediators. The modulation of ENA-78 concentration in the local environment by these mediators may contribute to the normal and pathological processes of human reproduction through regulation of leukocyte trafficking into the endometrium.

Expression of receptor tyrosine kinase EphB4 and its ligand ephrin-B2 is associated with malignant potential in endometrial cancer

The protein kinases includes many oncogenes and growth-factor receptors, as well as genes that are involved in cell cycle regulation. EphB4 receptors are a subfamily of receptor tyrosine kinases that are activated by ephrin-B2 ligands and are thought to play an important role in the development and oncogenesis of various tissues. However, very little experimental evidence exists to support this hypothesis. To elucidate the involvement of EphB4 and ephrin-B2 in endometrial carcinogenesis, we used fluorescent immunohistochemistry to analyze serial frozen sections of 20 endometrial carcinomas and 20 normal endometria for EphB4 and ephrin-B2 protein expression. We analyzed the relationship between the patient's characteristics and the percentages of EphB4- and ephrin-B2-stained cells. EphB4 expression was significantly associated with histological grade (p < 0.001) and certain clinical stages. Ephrin-B2 Expression was significantly associated with the presence of invasion to > 1/2 myometrium (p = 0.002). Our results demonstrate that increased EphB4 and ephrin-B2 expression may reflect or induce in endometrial carcinomas increased potential for growth and tumorigenicity. Furthermore, these results suggest that EphB4 receptor kinase may modulate the biological behavior of endometrial carcinomas through autocrine and/or paracrine activation, which is caused by ephrin-B2 ligands that are expressed in the same or neighbouring cells by immunohistochemistry.

Effects of platelet-activating factor on cytokine production by human uterine cervical fibroblasts

Platelet-activating factor (PAF), a lipid that acts as a potent proinflammatory mediator, is involved in several reproductive processes including parturition. To investigate the effects of PAF on expression of various cytokines by cultured human uterine cervical fibroblasts obtained at term prior to labour, Northern blot analyses and enzyme-linked immunosorbent assays were performed. C-PAF, a stable analogue of PAF, increased expression of interleukin-6 and -8 mRNA in a dose-dependent manner (10(-10) to 10(-8) mol/l of C-PAF), and the expression peaked within 4 h. The corresponding protein concentrations were increased in culture media. Monocyte chemoattractant protein-1 mRNA showed marked induction by 10(-8) mol/l of C-PAF; this peaked by 4 h and was followed by an increase in the protein concentration. Another cytokine, RANTES (regulated upon activation, normal T cell expressed and secreted) showed marked mRNA induction by 10(-8) mol/l of C-PAF, and continued to increase in a time-dependent manner until 24 h. The protein concentration was correspondingly increased in the medium. The PAF-induced cytokine production was abolished by co-incubation with WEB 2170, a specific PAF receptor antagonist. PAF may stimulate local production of cytokines which may induce migration of leukocytes and accelerate collagenolysis in the uterine cervix, thus contributing to cervical ripening during parturition.

Id1 expression is associated with histological grade and invasive behavior in endometrial carcinoma

Basic helix-loop-helix (bHLH) DNA-binding proteins have been reported to regulate tissue-specific transcription of cellular differentiation within multiple cell lineages. The Id family of helix-loop-helix proteins does not possess a basic DNA-binding domain and functions as a negative regulator of bHLH proteins by forming high-affinity heterodimers with bHLH proteins. Id proteins were originally characterized as inhibitors of DNA binding and cell differentiation. Thus, overexpression of Id proteins correlates with cell proliferation and arrested differentiation in many cell lineages. To elucidate the involvement of Id1 in endometrial carcinogenesis, we analyzed serial frozen sections for Id1 protein expression in 20 cases of endometrial carcinoma and 20 cases of normal endometria by fluorescent immunohistochemistry. We analyzed the relationship between the percentages of Id1-stained cells and the patient's characteristics, including histological grade, clinical stage, presence of invasion to >1/2 myometrium, and clinical outcome. In normal endometria, Id1 was not detected in either the proliferative or the secretory phase. There was, however, abundant Id1 immunoreactivity in the endometrial carcinoma cells. Moreover, Id1 was strongly expressed in the inflammatory cells. Scoring on the basis of the percentage of positive cells indicated that Id1 expression is significantly associated with histological grade (P<0.05) and the presence of invasion to >1/2 myometrium (P<0.05). Our results demonstrate that increased Id1 expression in endometrial carcinoma correlates with the malignant potential of this tumor.