20 resultados para Stroma


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Abstract Background Remodeling of the extracellular matrix is one of the most striking features observed in the uterus during the estrous cycle and after hormone replacement. Versican (VER) is a hyaluronan-binding proteoglycan that undergoes RNA alternative splicing, generating four distinct isoforms. This study analyzed the synthesis and distribution of VER in mouse uterine tissues during the estrous cycle, in ovariectomized (OVX) animals and after 17beta-estradiol (E2) and medroxyprogesterone (MPA) treatments, either alone or in combination. Methods Uteri from mice in all phases of the estrous cycle, and animals subjected to ovariectomy and hormone replacement were collected for immunoperoxidase staining for versican, as well as PCR and quantitative Real Time PCR. Results In diestrus and proestrus, VER was exclusively expressed in the endometrial stroma. In estrus and metaestrus, VER was present in both endometrial stroma and myometrium. In OVX mice, VER immunoreaction was abolished in all uterine tissues. VER expression was restored by E2, MPA and E2+MPA treatments. Real Time PCR analysis showed that VER expression increases considerably in the MPA-treated group. Analysis of mRNA identified isoforms V0, V1 and V3 in the mouse uterus. Conclusion These results show that the expression of versican in uterine tissues is modulated by ovarian steroid hormones, in a tissue-specific manner. VER is induced in the myometrium exclusively by E2, whereas MPA induces VER deposition only in the endometrial stroma.

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Abstract Background Immunological alterations are implicated in the increased prevalence of high-grade squamous intraepithelial lesions (HG-SIL) and persistent human papillomavirus (HPV) infection. This study evaluated the expression of CD4, CD8, CD25 (IL-2Rα) and CD28 antigens from SIL biopsies, stratified by HIV status and HPV-type. Biopsies specimens from 82 (35 HIV+) women with a normal cervix, low-grade (LG-SIL) or high-grade lesions (HG-SIL) were studied. CD molecule expression was evaluated by immunohistochemistry and HPV detection/typing performed using PCR techniques. Results CD4 stromal staining was increased in patients with HPV18. Women with HPV16 infection showed decreased: a) CD8 and CD25 stromal staining, b) CD25 staining in LG-SIL epithelium and in HG-SIL stroma. In HIV- women samples, CD28 epithelial staining and CD8 stromal staining surrounding metaplastic epithelium were less intense and even absent, as compared to HIV+ women. Both epithelial and stromal CD8 staining was more intense in the HG-SIL/HIV+ group than in the HG-SIL/HIV- group. Positive correlations were observed between CD4/CD25, CD4/CD28 and CD25/CD28 in the stroma and CD25/CD28 in the epithelium. Conclusion HIV status and HPV-type may influence the lymphomononuclear cell profile present in the spectrum of cervical lesions. The knowledge of the infiltrating cell profile in cervical tumours may help the development of specific anti-tumoural strategies.

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Abstract Introduction Endometrial ossification is an uncommon disease related to secondary infertility and its etiology and pathogenesis are controversial. More than 80% of reported cases occur after pregnancy. Case presentation A 33-year-old Caucasian woman was admitted with a history of secondary infertility and with a regular menstrual cycle. She reported a miscarriage at 12 weeks of gestation 7 years previously and subsequent dilatation and curettage in another medical facility. Vaginal ultrasound was performed and showed an intrauterine structure described as a hyperechogenic image suggesting calcification related to chronic endometritis. Office hysteroscopy revealed a wide endometrial cavity and proliferative endometrium, with a coral-like white plaque 1.5 cm in length on the right horn and posterior wall of the uterus. The lesion was treated by hysteroscopy without complications. Microscopic examination showed endometrial tissue with osseous metaplasia in the stroma. Nine months after the procedure, the patient became pregnant spontaneously. Conclusion In our patient, hysteroscopy was effective in the diagnosis and treatment of osseous metaplasia of the endometrium associated with infertility.

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In mammalian species, profibrogenic cells are activated to become myofibroblasts in response to liver damage. Few studies have examined hepatic myofibroblasts and their role in liver damage in teleosts. The aim of the present study was to investigate the involvement of myofibroblast-like cells in rainbow trout (Oncorhynchus mykiss) with hepatic damage induced by aflatoxin B1 (AFB1). Histopathological and immunohistochemical analyses characterized alterations in the liver stroma during the carcinogenic process. Anti-human a-smoothmuscle actin (SMA) and anti-human desmin primary antibodies were used in immunohistochemistry. Only the anti-SMA reagent labelled cells in trout liver. In the livers of control fish, only smooth muscle in blood vessels and around bile ducts was labelled. In the livers from AFB1-treated fish, SMA-positive cells were present in the stroma surrounding neoplastic lesions and in areas of desmoplastic reaction. These observations indicate that in teleosts, as in mammals, the myofibroblast-like cell is involved in fibrosis associated with liver injury. Chronic liver injury induced in trout by aflatoxin may provide a useful model system for study of the evolution of such mechanisms.

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We have previously shown the differential expression of versican in the mouse uterus under ovarian hormone influence. We also demonstrated there is not a direct correlation between mRNA levels and protein expression, suggesting posttranscriptional events, such as alteration in mRNA stability. This posttranscriptional effect may result in the elongation and stabilization of transcripts poly(A) tail. Thus, the aim of this study was to analyze whether estradiol (E2) regulates versican mRNA stability and expression in a dose-related and time-dependent manner. For this purpose female mice were ovariectomized and treated with a single injection of 0.1 or 10 μg E2. To block transcription a group of females received a single injection of alpha-amanitin before hormone administration. Uterine tissues were collected 30 min, 1, 3, 6, 12 and 24 h after treatments and processed for quantitative real time PCR (qPCR), RACE-PAT Assay and immunohistochemistry. qPCR showed that versican mRNA levels are higher than control from 3 to 24 h after E2 administration, whereas after transcription inhibition versican mRNA unexpectedly increases within 3 h, which can be explained when transcriptional blockers alter the degradation rate of the transcript, resulting in the superinduction of this mRNA. Accordingly, analysis of versican transcript poly(A) tail evidenced a longer product 3 h after treatment, but not after 12 h. Versican immunoreaction becomes conspicuous in the superficial stroma only 3 h after E2 injection, whereas the whole stroma is immunoreactive from 6 h onward. These results demonstrate that E2 modulates versican at the transcriptional and posttranscriptional levels in a time-dependent manner.