Homocysteine and age-associated disorders

There are numerous theories of aging, a process which still seems inevitable. Aging leads to cancer and multi-systemic disorders as well as chronic diseases. Decline in age- associated cellular functions leads to neurodegeneration and cognitive decline that affect the quality of life. Accumulation of damage, mutations, metabolic changes, failure in cellular energy production and clearance of altered proteins over the lifetime, and hyperhomocysteinemia, ultimately result in tissue degeneration. The decline in renal functions, nutritional deficiencies, deregulation of methionine cycle and deficiencies of homocysteine remethylation and transsulfuration cofactors cause elevation of homocysteine with advancing age. Abnormal accumulation of homocysteine is a risk factor of cardiovascular, neurodegenerative and chronic kidney disease. Moreover, approximately 50% of people, aged 65 years and older develop hypertension and are at a high risk of developing cardiovascular insufficiency and incurable neurodegenerative disorders. Increasing evidence suggests inverse relation between cognitive impairment, cerebrovascular and cardiovascular events and renal function. Oxidative stress, inactivation of nitric oxide synthase pathway and mitochondria dysfunction associated with impaired homocysteine metabolism lead to aging tissue degeneration. In this review, we examine impact of high homocysteine levels on changes observed with aging that contribute to development and progression of age associated diseases.

Endometrial osteopontin, a ligand of beta3-integrin, is maximally expressed around the time of the "implantation window"

OBJECTIVE

To analyze endometrial mRNA and protein expression of osteopontin and its receptor, beta3-integrin, throughout the menstrual cycle.

DESIGN

Study by immunohistochemistry, RNase protection assay, and ELISA.

SETTING

Academic research unit.

PATIENT(S)

Forty-five regularly cycling women without endometrial pathology.

INTERVENTION(S)

Expression of endometrial osteopontin and beta3-integrin mRNA was analyzed by RNase protection assay in endometrium, endometrial epithelial cells, stromal cells, and endometrial leukocytes (CD45) and by immunohistochemistry in frozen sections of endometrium throughout the menstrual cycle. Concentration of osteopontin was studied in uterine secretions by ELISA.

MAIN OUTCOME MEASURE(S)

mRNA and protein expression of osteopontin and beta3-integrin.

RESULT(S)

Osteopontin mRNA and protein was weakly expressed in the proliferative phase and maximally expressed in the mid to late secretory phases in endometrium, endometrial epithelial cells, and endometrial leukocytes and in uterine secretions. Beta3-integrin mRNA and protein were expressed in stromal cells throughout the menstrual cycle and were maximally expressed in epithelial cells in the mid to late secretory phases.

CONCLUSION(S)

Expression of osteopontin and its receptor, beta3-integrin, in human endometrial glands and osteopontin secretion into the uterine cavity around the time of the "implantation window" suggest a role for these proteins in endometrial function and implantation.

Lefty inhibits receptor-regulated Smad phosphorylation induced by the activated transforming growth factor-beta receptor

Transforming growth factor-beta (TGF-beta) is a pleiotropic cytokine that regulates growth and differentiation of diverse types of cells. TGF-beta actions are directed by ligand-induced activation of TGF-beta receptors with intrinsic serine/threonine kinase activity that trigger phosphorylation of receptor-regulated Smad (R-Smad) protein. Phosphorylated R-Smad proteins bind to Smad4, and the complexes formed move into the nucleus, where they act as components of a transcriptional complex. Here, we show that TGF-beta signaling is inhibited by lefty, a novel member of the TGF-beta superfamily. Lefty perturbed TGF-beta signaling by inhibiting the phosphorylation of Smad2 following activation of the TGF-beta receptor. Moreover, lefty inhibited the events that lie downstream from R-Smad phosphorylation, including heterodimerization of R-Smad proteins with Smad4 and nuclear translocation of the R-Smad.Smad4 complex. Lefty repressed TGF-beta-induced expression of reporter genes for the p21, cdc25, and connective tissue growth factor promoters and of a reporter gene driven by the Smad-binding element. Similarly, lefty inhibited both BMP-mediated Smad5 phosphorylation and gene transcription. The action of lefty does not appear to depend on protein synthesis, including synthesis of inhibitory Smad proteins. Thus, lefty provides a repressed state of TGF-beta- or BMP-responsive genes and participates in negative modulation of TGF-beta and BMP signaling by inhibition of phosphorylation of R-Smad proteins.

Lefty proteins exhibit unique processing and activate the MAPK pathway

Lefty polypeptides, novel members of the transforming growth factor-beta (TGF-beta) superfamily, are involved in the formation of embryonic lateral patterning. Members of the TGF-beta superfamily require processing for their activation, suggesting cleavage to be an essential step for lefty activation. Transfection of different cell lines with lefty resulted in expression of a 42-kDa protein, which was proteolytically processed to release two polypeptides of 34 and 28 kDa. Since members of the proprotein convertase (PC) family cleave different TGF-beta factors and are involved in the establishment of embryonic laterality, we studied their role in lefty processing. Cotransfection analysis showed that PC5A processed the lefty precursor to the 34-kDa form in vivo, whereas furin, PACE4, PC5B, and PC7 had a limited activity. None of these PCs showed activity in the processing of the lefty polypeptide to the 28-kDa lefty form. The mutation of the consensus sequences for PC cleavage in the lefty protein allowed the lefty cleavage sites to be identified. Mutations of the sequence RGKR to GGKG (amino acids 74-77) and of RHGR to GHGR (amino acids 132-135) prevented the proteolytic processing of the lefty precursor to the 34- and 28-kDa forms, respectively. To identify the biologically active form of lefty, we studied the effect of lefty treatment on pluripotent P19 cells. Lefty did not induce Smad2 or Smad5 phosphorylation, Smad2/Smad4 heterodimerization, or nuclear translocation of Smad2 or Smad4, but activated the MAPK pathway in a time- and dose-dependent fashion. Further analysis showed the 28-kDa (but not the 34-kDa) polypeptide to induce MAPK activity. Surprisingly, the 42-kDa lefty protein was also capable of inducing MAPK activity, indicating that the lefty precursor is biologically active. The data support a molecular model of processing as a mechanism for regulation of lefty signaling.

Identification of a prodromal period in Crohn's disease but not ulcerative colitis

OBJECTIVES

Irritable bowel syndrome, a common gastrointestinal diagnosis, has not been clearly studied in inflammatory bowel disease. Some of the residual symptoms in subjects treated with Crohn's disease and ulcerative colitis are thought to be related to irritable bowel syndrome. The aims of this study were 1) to describe the duration and nature of complaints before the diagnosis of Crohn's disease and ulcerative colitis (prodromal period), and 2) to determine the role of IBS in this prodromal period.

METHODS

A total of 66 patients with confirmed inflammatory bowel disease were enrolled in the study. The subjects received a questionnaire to ascertain the nature and duration of symptoms preceding the diagnosis of Crohn's disease or ulcerative colitis, including features described under the Rome criteria for irritable bowel syndrome.

RESULTS

Of the 66 subjects analyzed, 45 had Crohn's disease and 21 had ulcerative colitis. The prodromal period was 7.7 +/- 10.7 yr for Crohn's disease and 1.2 +/- 1.8 yr for ulcerative colitis (p < 0.05). Once patients meeting the Rome criteria for irritable bowel syndrome during the prodrome were excluded, the duration of the prodromal period (non-IBS) for ulcerative colitis dropped to 0.8 +/- 1.3 yr compared to 6.9 +/- 9.8 yr in the Crohn's disease group (p < 0.05). The symptoms of the non-IBS prodrome in subjects with Crohn's disease were bloating, diarrhea, stomach pain, heartburn, fever, weight loss, and fatigue. Further analysis demonstrated that subjects whose Crohn's disease initially began as colonic disease had a longer prodrome than with small bowel. In the non-IBS Crohn's group, there was also a correlation between the age at the time of diagnosis and the duration of prodrome (r = 0.67, p < 0.0001).

CONCLUSIONS

There is a significant prodromal period before the time of diagnosis of Crohn's disease that is not found in ulcerative colitis even after exclusion of subjects with IBS.

Dysregulated expression of ebaf, a novel molecular defect in the endometria of patients with infertility

We recently described the expression of ebaf, a novel member of the transforming growth factor-beta superfamily in human endometrium. ebaf messenger ribonucleic acid was expressed in late secretory and menstrual endometria. Here, we show that ebaf is secreted as 42-, 34-, 28-, and 14-kDa proteins into the conditioned medium of transfected cells, endometrial fluid, and serum. The amount of secreted proteins was markedly reduced during the implantation window in the endometria and sera of normal fertile subjects. The expression of ebaf was dysregulated in the endometria of a subset of women with infertility during the receptive phase of the menstrual cycle. Abundant secreted protein was present in the endometria of these women during the implantation window. During the critical period of endometrial receptivity, ebaf protein was more abundant in patients with endometriosis who did not conceive than in patients who became pregnant. These findings show that ebaf is a secreted product and is released into body fluids. Some types of infertility are associated with dysregulated expression of ebaf in human endometrium, suggesting that a molecular defect in uterine receptivity may be identified using such a marker protein.

Regulated expression of cytokines in human endometrium throughout the menstrual cycle: dysregulation in habitual abortion

It is widely assumed that, after ovulation, the human endometrium undergoes specific changes and becomes receptive to the implantation of embryo during the mid-secretory phase. When implantation does not take place, further changes occur which eventually result in the shedding of human endometrium. The present study was carried out to examine whether there are changes in the cytokine gene expression in human endometrium which are correlated with endometrial function in various phases of the menstrual cycle. The RNase protection assay was performed on carefully dated endometria from normal subjects to characterize the expression of cytokines which potentially contribute to endometrial function. These included: tumour necrosis factor (TNF), interleukin (IL)-1beta, IL-6, IL-8, leukaemia inhibitory factor (LIF), transforming growth factor beta1 (TGF-beta1), macrophage colony stimulating factor (MCSF or colony stimulating factor-1), and vascular endothelial growth factor (VEGF) mRNAs. A low level of expression of these cytokine mRNAs was found during the proliferative and early secretory phase. Expression of cytokine mRNA increased during the mid-secretory phase and rose to a peak in the late secretory phase. The level of cytokine mRNA expression during gestation was most akin to that observed during the mid-secretory phase. Individuals with habitual abortion presented with an abnormal expression of IL-1beta and IL-6 mRNA in endometrium, during the mid-secretory phase. Taken together, these findings are consistent with a progressive rise in the expression of cytokines in human endometrium during the secretory phase in natural cycles. Furthermore, the findings show that habitual abortion is associated with the abnormal expression of IL-1beta and IL-6 in the mid-secretory phase.

Progestin regulation of human endometrial function

A well-orchestrated sequence of events enables the human endometrium to become receptive to embryo implantation during a defined period in the menstrual cycle. Ovarian steroids, oestradiol and progesterone, regulate many of these functions in a highly co-ordinated manner. There are no experimental systems for critically examining the regulation of endometrial functions by steroid hormones, especially those responses restricted to the epithelium. Using an experimental xenograft model where the steroid responses of normal endometrium could be predictably recapitulated, the role of progesterone in the regulation of alpha crystallin B in the glandular epithelial cells of human endometrium was established.

From endometrial receptivity to infertility

Implantation of the blastocyst in endometrium requires establishment of a coordinated molecular dialogue between the embryo and the endometrium. Factors instrumental in the preparation of a receptive endometrium are derived from the hypothalamic-pituitary-gonadal axis. These factors modulate the expression of genes that drive the endometrium throughout the characteristic menstrual cycles. During each menstrual cycle, a series of coordinated, architectural, morphological, cytochemical, and molecular changes ultimately lead to the preparation of a receptive endometrium during the putative "receptive period" or "implantation window." It is during this critical period that a proper dialogue can be established between an intrusive blastocyst and a receptive endometrium. If, for any reason, this dialogue is not established or is perturbed, the embryo is aborted. The natural fate of the receptive endometrium, in the absence of implantation, is development of a second set of changes that ultimately lead to menstruation. The identity of the molecular repertoire that makes endometrium receptive to implantation and/or lead to menstruation is being revealed and broadly includes cytokines, heat shock factors, adhesion molecules and matrix metalloproteases. We identified a novel gene of the transforming growth factor-beta, superfamily of molecules, the so-called endometrial bleeding--associated factor or ebaf, whose expression is confined to the late secretory and menstrual phases. Various forms of female infertility were associated with dysregulated expression of ebaf during the implantation window. The findings show an occult molecular defect of endometrial receptivity that seems to be due to dysregulated and premature expression of a member of the premenstrual molecular repertoire. The dysregulated expression of ebaf may assist in the identification, prognostication, and monitoring of treatment of infertile women.

Regulation of TNF-alpha mRNA expression in endometrial cells by TNF-alpha and by oestrogen withdrawal

During each menstrual cycle, the human endometrium undergoes a series of orchestrated and well controlled changes in anticipation of the arrival of the blastocyst. In the absence of implantation, the endometrium is shed. The underlying basis of the menstrual bleeding is not clear, however, it seems to be related to steroid hormone withdrawal. We showed that tumour necrosis factor-alpha (TNF-alpha) is released by human endometrium and that endometrial epithelial cells are a major source of TNF-alpha mRNA and protein. We show here that TNF-alpha mRNA shows a specific menstrual cycle-dependent expression. The expression of TNF-alpha is mostly minimal throughout the proliferative, early and mid-secretory phases. Expression of TNF-alpha mRNA, however, is increased in the human endometrium in the late secretory phase and during endometrial bleeding. Such a menstrual cycle-dependent expression suggests that specific signals regulate the expression of TNF-alpha mRNA in the human endometrium. In vitro, the expression of TNF-alpha mRNA in endometrial epithelial cells could be regulated by exogenous TNF-alpha. This induced expression was both time- and dose-dependent. In vitro, the TNF-alpha mRNA expression was not altered by oestrogen, progesterone, or both, in the endometrial epithelial cells under conditions that maintain the steroid hormone receptors. However, in vivo, oestrogen withdrawal led to an enhanced expression of TNF-alpha in endometrial epithelial cells. These findings suggest that the up-regulation of TNF-alpha in human endometrium in the late secretory phase may be related to the falling serum oestrogen concentration at the end of the menstrual cycle as well as the potentiating effect of released TNF-alpha on its own mRNA expression.

An experimental model for the endometriosis in athymic mice

Endometriosis is an adhesion disorder characterized by the presence of endometrial tissue in ectopic sites outside the uterus. The disease is associated with dysmenorrhea, pelvic pain and infertility. Although endometriosis is the most common gynecologic disorder, relatively little is known regarding its etiology, pathogenesis and the course of the disease. This situation is primarily due to the absence of experimental systems to examine the mechanism of endometrial cell adhesion, role of inflammatory cells and the interactions of epithelial, and stromal cells with the peritoneum and ovarian tissue leading to the development of this disorder. Dissociated human endometrial cells were suspended in peritoneal fluids of individuals with and without endometriosis and were injected into the peritoneal cavity of athymic mice. This led to development of ectopic adhesions of endometrial cells at the peritoneal and ovarian surfaces. Endometrial cells which were marked with fluorescent lipophylic dyes, prior to intraperitoneal injection, could be visualized without surgery at such sites. The studies demonstrate a model for endometriosis in athymic mice.

Multiprobe RNase protection assay with internally labeled radioactive probes, generated by RT-PCR and nested PCR

RNase Protection Assay (RPAs) is a highly sensitive and reproducible method of quantitating the levels of specific mRNA transcripts. The introduction of the commercially available Multiprobe RPAs allow comparing and quantifying the expression of up to different mRNA species in a single sample of 1-20 micrograms of total RNA. To generate probes which are not commercially available, we prepared highly specific probes by RT-PCR and nested PCR. Then, after ligation of a T7 promoter, another PCR was performed with a primer set consisting of a specific sense primer and antisense T7 primer. Only the antisense strand of the double stranded PCR-product contained the T7-promoter sequence on its 5' end, allowing in vitro transcription and internal labeling with [alpha-32]UTP. Probe concentration was determined in a scintillation counter and equal counts were introduced in the assay. In vitro transcription of the PCR generated probes resulted in radioactive probes with a very high specific activity, allowing simultaneous analysis of 70 different RNA samples. RPA could be performed under the same conditions as recommended for the commercially available probe sets, avoiding time consuming optimization of reaction conditions. Negative controls consisted of yeast RNA and sense RNA probes. Positive controls were single stranded templates, generated by asymmetric PCR. Dilution series revealed a high reproducibility and the potential of this technique to semi-quantitate mRNA in different RNA samples. In conclusion, probes may be generated by RT-PCR and nested PCR that will work with the commercially available Multiprobe RPAs. The high probe yield allows analysis of a great number of samples using the same set of probes with a high reproducibility.

Heat shock proteins in human endometrium throughout the menstrual cycle

Human endometrium, in response to steroid hormones, undergoes characteristic cycles of proliferation, secretory changes, and tissue shedding. Human endometrium expresses a molecular repertoire which includes the heat shock proteins (Hsps) Hsp27, Hsp60, Hsp70, Hsp90, and alpha crystallin B chain. The expression of Hsp27, Hsp60, and the constitutive form of Hsp70 (Hsc70) shows a sharp increase in human endometrium after ovulation. The maximal expression of the molecular chaperone, alpha crystallin B chain, occurs during the secretory phase. In view of known functions of the Hsps, it is likely that these proteins are involved in protection of the endometrial proteins against factors with the potential to lead to protein denaturation. Tumor necrosis factor-alpha (TNF-alpha) is a cytotoxic cytokine that is produced in progressive amounts during the secretory phase. The function of the Hsps may be to protect cells against the cytotoxic damage of TNF-alpha, particularly during the critical period of "implantation window."

Molecular control of the implantation window

Human endometrium is the end organ of the hypothalamic-pituitary-ovarian axis. Therefore, endometrium is susceptible to changes in the cases of infertility that originate from disturbances in the normal functioning of this axis. In addition, some cases of unexplained infertility may be due to altered endometrial function. This disturbed endometrial function may originate from lesions in the molecular repertoire that are crucial to implantation. Human endometrium becomes receptive to implantation by the blastocyst within a defined period during the menstrual cycle. The duration of this so-called 'endometrial receptivity' or 'implantation' period seems to span from few days after ovulation to several days prior to menstruation. Successful implantation results from a co-ordinated series of events that would allow establishment of a timely dialogue between a receptive endometrium and an intrusive blastocyst. The members of the molecular repertoire that make endometrium receptive to implantation are gradually being recognized. Among these are the cytokines, integrins, heat shock proteins, tastin and trophinin. In addition, the expression of a second set of genes including tumour necrosis factor alpha (TNF-alpha) and ebaf, may be the appropriate signal for the closure of the 'implantation window', for making the endometrium refractory to implantation and for preparing it for the menstrual shedding.

Temporal and site-specific expression of transforming growth factor-beta4 in human endometrium

We recently identified a novel member of the transforming growth factor (TGF)-beta superfamily and showed that this gene, designated as endometrial bleeding associated factor (ebaf), or TGFbeta4, has a unique expression pattern in human endometrium. By Northern blot analysis, we showed that this gene was expressed in human endometrium during the late secretory and menstrual phases and was absent in proliferative, early and mid-secretory endometria. In this report, we show by in-situ hybridization that the mRNA of the TGF-beta4 is not expressed in the proliferative endometria. On the other hand, focal expression of the TGFbeta4 mRNA first appears in some endometrial glands in the mid-secretory phase. The TGFbeta4 mRNA is strongly expressed in the endometrial stroma during the late secretory and menstrual phases of the cycle. We raised a polyclonal rabbit antiserum against a peptide at the C terminal of the protein. Western blot analysis using affinity purified antiserum shows that the TGFbeta4 precursor detected in the endometrium as well as placenta is 41 kDa. Bands in the range of 45-51 kDa are also present in human endometrium, more predominantly during the late secretory phase. Immunohistochemical staining shows a low level of immunoreactivity for TGFbeta4 in the early, mid- and late proliferative and early and mid-secretory endometria. A strong immunoreactivity for TGFbeta4 is present in the stroma and to lesser extent in the endometrial glands in late secretory and menstrual endometria. The specificity of staining was shown by neutralizing the activity of the antibody with the synthetic peptide used for raising the antibody and by omitting the antibody. The findings show that TGFbeta4, both at the mRNA and protein levels, exhibits temporal and site specific expression in human endometrium.

Constitutive expression of the HTLV-I pX and env regions in Jurkat T-cells induces differential activation of SRE, CRE and NF kappa B pathways

Human T-cell leukemia virus type I (HTLV-I) causes adult T-cell leukemia/lymphoma (ATLL). HTLV Tax, the viral transcriptional activator, can activate a variety of cellular genes. HTLV-mediated T-cell transformation, however, may involve additional viral proteins expressed from singly- as well as doubly-spliced viral mRNA. To determine the combined effect of these viral proteins on cellular gene expression in Jurkat T-cells, we derived stable transfectants that constitutively express the HTLV-I pX and env regions (J3.9). J3.9 cells show substantially increased mRNA levels of egr-1 and c-jun but no induction of either CD25 or GM-CSF by Northern blotting. This pattern corresponded to the activation of an egr-1 but not a GM-CSF promoter-driven reporter construct in transient gene expression assays. In DNA electrophoretic mobility shift assays (EMSA), nuclear extract from J3.9 cells has significantly increased binding to CRE and SRE but not nuclear factor kappa B (NF kappa B) DNA oligos, as compared to J-Neo cell extract. These results suggest that low level expression of pX and env region gene products in Jurkat T-cells stimulates persistent activation of CRE- and SRE- but not NF kappa B-induced cellular genes.

Distinct tumor specific expression of TGFB4 (ebaf)*, a novel human gene of the TGF-beta superfamily

We recently identified a novel gene of the TGF-beta superfamily, endometrial bleeding associated factor, TGFB4 (ebaf), that, throughout the menstrual cycle, exhibited a defined expression in human endometrium. Here, we report on the expression of TGFB4 (ebaf) in normal and neoplastic human tissues. The expression of this gene was absent in a host of normal tissues including lung, stomach, small bowel, liver, kidney, breast, lymph node, spleen, ovary and fallopian tube. However, a weak expression of the 2.1 kb variant of the TGFB4 (ebaf) mRNA was observed in rectal, ovarian, and testicular tissues and the 2.1 and 2.5 kb TGFB4 (ebaf) mRNAs were observed in the pancreatic tissue. The expression of the mRNA of this gene was absent in sarcomas, Hodgkin's and non-Hodgkin's lymphomas, melanomas, squamous cell carcinomas, hepatocellular carcinomas, renal cell carcinomas, and adenocarcinomas of the breast, endometrium and lung. The expression of the TGFB4 (ebaf) mRNA was observed primarily in adenocarcinomas that exhibited a mucinous differentiation. This included colonic, duodenal, and ovarian adenocarcinomas. The expression of TGFB4 (ebaf) mRNA was absent in non- mucinous colonic, gastric and ovarian adenocarcinomas and adenocarcinomas of colon metastatic to the liver. However, some serous adenocarcinomas of the ovary also exhibited TGFB4 (ebaf) mRNA. The testicular tumors, seminomas and embryonal carcinomas, also expressed TGFB4 (ebaf) mRNA. These findings show that the TGFB4 (ebaf) mRNA has distinct tumor specific expression.

Detection of ebaf, a novel human gene of the transforming growth factor beta superfamily association of gene expression with endometrial bleeding

Human endometrium is unique since it is the only tissue in the body that bleeds at regular intervals. In addition, abnormal endometrial bleeding is one of the most common manifestations of gynecological diseases, and is a prime indication for hysterectomy. Here, we report on a novel human gene, endometrial bleeding associated factor (ebaf), whose strong expression in endometrium was associated with abnormal endometrial bleeding. In normal human endometrium, this gene was transiently expressed before and during menstrual bleeding. In situ hybridization showed that the mRNA of ebaf was expressed in the stroma without any significant mRNA expression in the endometrial glands or endothelial cells. The predicted protein sequence of ebaf showed homology with and structural features of the members of TGF-beta superfamily. Fluorescence in situ hybridization showed that the ebaf gene is located on human chromosome 1 at band q42.1. Thus, ebaf is a novel member of the TGF-beta superfamily and an endometrial tissue factor whose expression is associated with normal menstrual and abnormal endometrial bleeding.

The progressive rise in the expression of alpha crystallin B chain in human endometrium is initiated during the implantation window: modulation of gene expression by steroid hormones

Human endometrium undergoes sequential changes during the menstrual cycle and becomes receptive to implantation during a defined period in the secretory phase. We attempted to identify the genes expressed during this period by representational difference analysis (RDA). When the cDNAs of a proliferative endometrium were used as the driver and the cDNAs of a post-ovulatory day 5 endometrium were used as the tester, a number of bands were identified by RDA. DNA of the cloned RDA products revealed that the majority of the clones contained a fragment of a cDNA identical to that of a crystallin B chain. Northern blot analysis showed that the expression of the alpha crystallin B chain mRNA was absent during the proliferative phase. The expression of the mRNA of alpha crystallin B chain first appeared in the secretory phase, progressively increased during this phase and peaked in the late secretory endometria. The pattern of expression of alpha crystallin B chain mRNA in the endometrium of mature cycling baboons (Papio anubis) was similar to that seen in human endometrium. As revealed by Western blot analysis, the expression of the alpha crystallin B chain protein in human endometrium followed a pattern of expression similar to its mRNA. At the cellular level, the immunoreactive protein first appeared in the surface epithelial cells of human endometrium within the implantation window without significant immunoreactivity in the underlying glandular cells. During the mid- and late secretory phases, the intensity of staining in the epithelial cells was enhanced and an intense immunoreactivity was developed in the glandular epithelium, alpha crystallin B chain was virtually an epithelial product and no immunoreactivity for this protein was detectable in the stromal cells, endothelial cells or lymphoid cells. The expression of alpha crystallin B chain could be regulated, by medroxy progesterone acetate as well as by oestrogen withdrawal, in human endometrial carcinoma cells (EnCa-101), transplanted to nude mice. Based on the data presented here, the known function of alpha crystallin B chain and its distinct pattern of expression in human endometrium, we suggest that this protein is an important factor within the molecular repertoire that makes endometrium receptive to implantation.

Murine IL-10 fails to reduce GVHD despite inhibition of alloreactivity in vitro

Graft-versus-host disease (GVHD) is a serious complication following allogeneic bone marrow transplantation (BMT). Initial immunologic events that are thought to lead to clinical GVHD include allogeneic antigen presentation, CD4+ T cell proliferation and eventually generation of specific cytotoxic lymphocytes. Interleukin-10 (IL-10) has been shown to inhibit the function of antigen presenting cells (APC) and to reduce lymphocyte proliferation. In this study we investigated the possible role of recombinant murine IL-10 (rmIL-10) as prophylactic treatment of GVHD in a murine BMT model involving B10.BR donor mice (H-2k) and AKR recipients (H-2k). In particular, we wished to determine whether early post-BMT administration of IL-10 would suppress GVHD by interfering with macrophage function and inflammatory cytokine production during the proposed "afferent' phase of GVHD. In MLR assays, rmIL-10 significantly inhibited the proliferation of donor spleen cells when stimulated by irradiated recipient spleen cells in a dose-dependent manner. In murine BMT, rmIL-10 was administered exogenously by intraperitoneal injection of 100 U daily in two different dosage schedules, on days-1, 0, 1, 2, 3, 6 to target the early post-BMT phase, and days-1, 0, 3, 5, 7, 10 after BMT, to administer the same total dose throughout the engraftment period. IL-10 injected mice had lower plasma IL-1 alpha levels on day 3 (12 pg/ml vs 64 pg/ml in controls, P < 0.05), suggesting that both macrophage function and inflammatory cytokine production were inhibited. In contrast to the MLR data, no significant improvement in morbidity and mortality from GVHD was observed. Therefore, IL-10 does not appear to be useful in GVHD prophylaxis.

Immunohistochemical analysis of the microanatomy of primate ovary

The ovary is a complex organ composed of cells of diverse lineages. Therefore, in this study we examined whether immunolocalization of various cytoskeletal, epithelial, immune-cell, and neural-associated proteins can differentiate various cells in the baboon and human ovaries. Surface epithelial cells exhibited immunoreactivity for cytokeratin and desmin, however, they did not immunostain for other epithelial markers such as carcinoembryonic antigen or epithelial membrane antigen. Smooth muscle actin was distributed apically whereas vimentin was localized basally in these cells. Ova exhibited strong immunoreactivity for S-100, Leu-M1, and neurofilament and did not show immunoreactivity for epithelial and cytoskeletal proteins. In antral follicles and theca cells, and after formation of corpus luteum, both granulosa and theca cells expressed immunoreactivity for vimentin. Cytokeratins were absent in the preantral and antral follicles. However, atresia and development of apoptosis was associated with expression of immunoreactive cytokeratins in atretic follicles. Development of corpus luteum led to major changes in the immunophenotype of follicular cells. The mere presence of immunoreactivity for cytokeratin and a strong immunoreactivity for desmin in the luteinized granulosa and not in the theca cells allowed discrimination of these cells from each other and from their ancestral cells. Proliferating cell nuclear antigen was present in various ovarian cells except for ovum. The distinct patterns of expression of cytoskeletal, epithelial, and neural-associated proteins in various cells of the ovary facilitates their identification and discrimination.

Heat shock proteins in human endometrium throughout the menstrual cycle

Human endometrium is a steroid-sensitive tissue and there is evidence that supports the viewpoint that heat shock proteins (HSP) are implicated in the regulation of steroid function. Therefore, in this study we examined the expression of various members of the heat shock family of proteins in the steroid-responsive human endometrium. Western blot analysis revealed that the expression of HSP90 showed minimal changes throughout the menstrual cycle. When normalized to the amount of HSP90, the expression of HSP27, HSP60 and the constitutive form of heat shock protein 70 (HSC70) increased progressively during the late proliferative and early secretory phases, and diminished in the mid- to late secretory and menstrual phases. In contrast, the inducible form of heat shock protein 70 (HSP70) did not undergo these changes. The cellular and subcellular localizations of these proteins were examined in human endometria by immunohistochemical staining. With the exception of HSP70, which was found primarily in the epithelial cells, the immunoreactivity for other heat shock proteins was found in both the stroma and the epithelium. Immunoreactivity for HSP27 was found in the lymphoid aggregates within endometrial stroma, and both HSP27 and HSP90 were found in endothelial cells. The immunoreactive heat shock proteins were found in the nuclei and/or cytoplasm of cells. However, no consistent nuclear versus cytoplasmic staining emerged, and such localization was irrespective of the site, the cell type or the phase of the menstrual cycle. Our findings show that endometrium has a full complement of heat shock proteins. The menstrual cycle-dependent changes in the amounts of heat shock protein suggest regulation by steroid hormones.

The signals and molecular pathways involved in human menstruation, a unique process of tissue destruction and remodelling

Human endometrium is a specialized tissue that undergoes sequential phases of proliferation and secretory changes in order to support the implantation and growth of an embryo. If implantation does not occur, this tissue rapidly undergoes dissolution during the menstrual period. Tissue shedding during menstruation is associated with significant apoptosis, disordered expression of adhesion molecules, loss of filamentous (F) actin from cell borders and fragmentation of endometrial glands. On the other hand, compromise of integrity of vessels and dissolution of the extracellular matrix leads to bleeding and tissue dissolution. The processes of bleeding and tissue shedding during menstruation are precisely controlled by a number of systemic and local factors. The systemic signal that leads to menstruation is the withdrawal of the steroid hormones. The available evidence suggests but does not yet prove that tumour necrosis factor (TNF)-alpha may serve as the local signal contributing to the processes of menstrual shedding and bleeding. Secretion of metalloproteinases and their subsequent activation induced by plasmin facilitates degradation of extracellular matrices and bleeding. The menstrual process ceases by secretion of steroid hormones directly or through regulation of production or activation of signals that lead to tissue shedding and bleeding.

Progressive rise in the expression of interleukin-6 in human endometrium during menstrual cycle is initiated during the implantation window

In order to be prepared for implantation, human endometrium undergoes a predictable series of proliferative and secretory changes. Cytokines play an important role in regulation of these changes. Therefore, in this study, we immunolocalized the cytokine, interleukin-6 (IL-6), its receptor and the signal transducer gp130 in human endometrium throughout the menstrual cycle. During the entire menstrual cycle, the IL-6 receptor and gp130 were found primarily in the endometrial glands and to a lesser extent in the stroma. The immunoreactivity of these proteins did not change in endometrial cells during the entire menstrual cycle with an exception of reduced immunoreactivity of gp130 in endometrial glands during menstrual phase. Immunostaining showed that immunoreactive IL-6 was weakly expressed in human endometrium during the proliferative phase. Strong immunoreactivity for IL-6 appeared in endometrium during the putative 'implantation window'. Expression was by far most pronounced both in the glandular and surface epithelial cells. The amount of immunoreactive IL-6 in the epithelium progressively increased during the secretory/menstrual phases. During the late secretory phase, only stromal cells in the upper functionalis exhibited immunoreactivity for IL-6. Western blot analysis corroborated the immunohistochemical data. Human endometrial IL-6 consisted of a protein with an apparent mobility of 26 kDa. The immunoreactive band of IL-6 was weak in the proliferative phase. The expression of this protein increased progressively during the secretory/menstrual phases. The findings show a cell-specific pattern of distribution for immunoreactive IL-6 in human endometrium. The menstrual cycle-dependent expression of IL-6 suggests that this cytokine may play a role in changes in endometrium that prepare this tissue for implantation and menstrual shedding.

TNF-α induces dyscohesion of epithelial cells. Association with disassembly of actin filaments

TNF-α induced, in a time and dose-dependent fashion, cell-cell dissociation (dyscohesion) of endometrial epithelial cells. Within the time frame that dyscohesion was induced, TNF-α, in a dose-dependent fashion, reduced filamentous (F) actin and resulted in the loss of F-actin from the intercellular boundaries. Loss of F-actin mediated by TNF-α was not due to a reduction in the overall amount of actin or its β-isoform. Two proteins, Rho and Rho guanine nucleotide dissociation inhibitor (Rho-GDI), have been implicated in the regulation of organization of actin cytoskeleton. The reduced level of F-actin was not associated with altered expression of Rho protein, however, it was associated with an increase in the amount of Rho available for ribosylationin vitro by the C3 exoenzyme of Clostridium botulinum. The amount of Rho-GDI protein did not change after treatment with TNF-α suggesting that elevated expression of this protein is not responsible for the disassembly of actin filaments. These findings show that TNF-α induces dyscohesion. Dyscohesion induced by this cytokine is associated with perturbation of the actin cytoskeleton which may be due to the regulatory role of TNF-α on Rho.

Signals and molecular pathways involved in apoptosis, with special emphasis on human endometrium

Apoptosis is a selective process for deletion of cells in various biological systems. This event, similar to proliferation, is tightly regulated, with both processes playing essential roles in the homeostasis of renewable tissues. In human endometrium, proliferation and apoptosis occur at opposing poles of the menstrual cycle. The proliferative phase is marked by rapid growth of the endometrial epithelial lining, whereas progressive increase in apoptosis in this tissue is the hallmark of the secretory and menstrual phases. The purpose of this review is to highlight some of the signals and molecular events which are associated with and that may participate in apoptosis. This is followed by a review of the current literature regarding apoptosis in human endometrium.

The signals and molecular pathways involved in implantation, a symbiotic interaction between blastocyst and endometrium involving adhesion and tissue invasion

Implantation is a complex process requiring the interaction of the blastocyst, and subsequently the developing embryo with the endometrium. Initially, the detailed cellular interactions implicated in this process were defined. More recently, many signals and molecular pathways are recognized that induce, or regulate the complex series of interactions required for implantation. In this review, the cellular and molecular interactions that take place during implantation are discussed.

Tumour necrosis factor-alpha-mediated dyscohesion of epithelial cells is associated with disordered expression of cadherin/beta-catenin and disassembly of actin filaments

Tumour necrosis factor (TNF)-alpha induced, in a time- and dose-dependent fashion, dyscohesion (cell-cell dissociation) of the endometrial epithelial cells. TNF-alpha impaired the ability of cells to aggregate and to attain compaction. The cell-cell adherent junction is a specialized region of the plasma membrane where cadherin molecules act as adhesion molecules and actin filaments are densely associated with the plasma membrane through a well-developed plasmalemmal undercoat. Dyscohesion induced by TNF-alpha was associated with the disordered expression of cadherin/beta-catenin at the sites of cell-cell contact. In addition, within the time-frame that dyscohesion was induced, TNF-alpha down-regulated the expression of actin mRNA only at 100 ng/ml without modulating the overall amount of actin protein, its beta-isoform or the amount of ribosylated actin. However, TNF-alpha-mediated dyscohesion of epithelial cells was associated with loss of plasmalemmal undercoat as well as intracytoplasmic aggregates of F-actin and a simultaneous increase in G-actin. The effect of cytochalasin-B, which disrupts actin filaments on cell-cell binding, was less pronounced than the effect of TNF-alpha, suggesting that the effect of this cytokine on dyscohesion is not solely dependent on the disassembly of actin filaments. These findings show that the induction of disordered expression of adhesion molecules, as well as disassembly of actin filaments, are implicated in the dyscohesion induced by TNF-alpha.

Menstruation is associated with disordered expression of desmoplakin I/II and cadherin/catenins and conversion of F- to G-actin in endometrial epithelium

Endometrium is unique since it is the only tissue that undergoes regular cyclic bleedings. Menstrual shedding is associated with the breakdown of endometrium, including the fragmentation of endometrial glands. To gain insight into the underlying basis of fragmentation of the endometrial epithelium during the menstrual phase, we examined the expression of proteins implicated in epithelial cell-cell binding in human endometria throughout the entire menstrual cycle. Western blotting failed to reveal differences in the relative amount of E-cadherin, alpha- or beta-catenin or actin in the menstrual endometria compared with those in the proliferative or secretory phases. However, specific changes in the expression pattern of these proteins as well as desmoplakin I/II were detected by immunohistochemical staining in epithelial cells of menstrual endometria. Desmoplakin I/II, E-cadherin, alpha- and beta-catenins and beta-actin were localized to intercellular borders as well as the luminal and basal regions of glandular epithelium during the proliferative and secretory phases. Immunoreactivity of E-cadherin and alpha-catenin was confined to epithelial cells, whereas beta-catenin and beta-actin were present in epithelial cells, as well as in stroma and endothelial cells. Binding of F-actin to fluorescein isothiocyanate-labelled phalloidin localized this form of actin to the intercellular borders, and the basal and luminal cytoplasm of epithelial cells in proliferative and secretory endometria. Menstrual shedding was associated with disorganization of the site-specific distribution of desmoplakin I/II, E-cadherin and alpha- and beta-catenins.(ABSTRACT TRUNCATED AT 250 WORDS)

Site and menstrual cycle-dependent expression of proteins of the tumour necrosis factor (TNF) receptor family, and BCL-2 oncoprotein and phase-specific production of TNF alpha in human endometrium

Apoptosis in human endometrial epithelium progressively increases from early to late secretory/menstrual phases and remains consistently more prominent in the basalis. It has been suggested that tumour necrosis factor (TNF) alpha secreted during the secretory/menstrual phases plays a role in induction of programmed cell death in these cells. In the present study, we characterized expression of receptors of TNF alpha, Fas antigen and BCL-2 in endometrial cells to gain insight as to whether this type of cell death in endometrium may be related to differential or preferential expression of these proteins at specific phases of the menstrual cycle. In addition, to relate production of TNF alpha to the development of apoptosis, the amount of TNF alpha released by human endometrium was measured. Immunostaining demonstrated that the TNF receptor (TNFr; p55/60)-I, TNFr-II (p75/80) as well as Fas protein were expressed in endometrial epithelium throughout the entire menstrual cycle. This expression was progressively diminished from the basalis towards the upper functionalis. In the proliferative phase, the expression of BCL-2 was prominent in the endometrial glands particularly in those residing in the basalis. This expression became weak as early as the third post-ovulatory day and remained low during the remaining phases of the menstrual cycle. The amount of TNF alpha released by endometrial fragments obtained from various phases of the menstrual cycle was determined. The amount of TNF alpha released into the culture medium by the endometrium was low in the proliferative phase. However, the amount of released TNF alpha progressively increased in the secretory phase and peaked in the menstrual phase. TNFr-I, TNFr-II, Fas, BCL-2 and TNF alpha could be identified by Western blot analysis of proteins extracted from endometrium. Therefore, endometrial epithelium by virtue of expression of receptors of TNF alpha as well as Fas protein is properly poised to respond to ligand signals that regulate apoptosis. Induction of apoptosis in endometrial epithelium and menstrual shedding may be related to loss of the protective effect of BCL-2 as well as to the amount of TNF alpha.

Expression of adhesion molecules in human endometrial vasculature throughout the menstrual cycle

In the present study, we examined the pattern of expression of human leukocyte antigen (HLA)-DR as well as several adhesion molecules implicated in leukocyte trafficking, including ICAM-1, E-selectin, and VCAM-1 in human endometrium. All of the vessels in endometrium exhibited HLA-DR and ICAM-1 throughout the menstrual cycle. In the proliferative phase, endothelial cells in the functionalis were weak to nonreactive for VCAM-1 and were E-selectin negative (E-selectin-). Endothelial cells of the vessels in the basalis and within myometrium were VCAM positive (VCAM-1+)/E-selectin-. In sharp contrast, in the secretory phase, endothelial cells in the basalis were VCAM-1+/E-selectin+. Surprisingly, endometrial glands, primarily those in the basalis, expressed E-selectin and VCAM-1 during the entire menstrual cycle. Stromal cells were ICAM-1+ and were focally HLA-DR+ around HLA-DR+ lymphoid cells during the entire menstrual cycle and were E-selectin-/VCAM-1- during the proliferative phase. Immunoreactivity for VCAM-1 and E-selectin, however, appeared in the stromal cells in the upper functionalis in the secretory phase. Immunoreactivity for VCAM-1 was the distinguishing feature that separated the lymphoid cells in the aggregates from other nonaggregated lymphoid cells. Recruitment of leukocytes to tissues is in part due to cytokine-regulated expression of specific molecules on endothelial cells. Therefore, we tested the effects of cytokines on the expression of these molecules in endothelial cells derived from microvasculature. ICAM-1 and VCAM-1 were inducible in a dose-dependent fashion in the endothelial cells by interleukin-1 alpha (IL-1 alpha), interferon-gamma (IFN gamma), and tumor necrosis factor-alpha (TNF alpha). Expression of HLA-DR in endothelial cells was inducible by IL-1 alpha and IFN gamma and not by TNF alpha. Expression of E-selectin on endothelial cells was induced only by IL-1 alpha, not by IFN gamma or TNF alpha. Cytokine treatment of endothelial cells significantly enhanced the binding of leukocytes to endothelial cells. The data show a heterogeneity in the vasculature of endometrium with respect to the expression of various adhesion molecules. This heterogeneity is potentially related to the type or amount of cytokine with which endothelial cells are activated. In addition, unique cell- and site-specific expression of adhesion molecules in human endometrium throughout the menstrual cycle may account for the distinct distribution pattern of leukocytes in this tissue.

Regulatory roles of IFN-gamma in human endometrium

Available data suggest that several microenvironments exist within the complex structure of human endometrium. Predecidual reaction which is associated with the expression of VLA-1 and alpha 1 PEG first appears in the stromal cells around the spiral arteries. Expression of Ber-EP4 is limited to a distinct group of stromal cells that reside around glands and underneath surface epithelium. A distinctly different group of stromal cells that surround lymphoid cells express HLA-DR molecules. The proliferative activity of endometrial epithelium is markedly higher in the upper functionalis and is gradually diminished towards the basalis. In addition, several proteins, including HLA-DR and some members of the integrin family of molecules are strongly expressed in the basalis epithelium. The expression of these proteins in endometrial epithelium is gradually diminished towards the surface. The gradual rather than abrupt changes in the expression of proteins and proliferative activity across the length of endometrial epithelium argues against separation of endometrium into the distinct regions of basalis and functionalis. Rather, such distribution is in favor of existence of a polarized microenvironment in human endometrium. Emerging evidence suggests that the development of this microenvironment is mediated by T cells activated within lymphoid aggregates with consequent secretion of IFN-gamma. IFN-gamma regulates HLA-DR expression and proliferation of endometrial epithelium. Maximal impact of the cytokine is exerted in regions close to the source of cytokine with a gradual dissipation of the effect distant from this source. Therefore, this cytokine may be the prototype of a group of paracrine factors that induce a polarized microenvironment in human endometrium.

Cytokines and the hypothalamic-pituitary-ovarian-endometrial axis

Recently, the demarcating boundaries that allowed separation of the fields of reproductive biology, endocrinology, immunology and neurobiology have faded. The missing link that now ties these disciplines together is the understanding that the language by which cells communicate within these diverse systems is unanimous. This language is the network of products collectively called cytokines. The effect of these factors spans from the hypothalamus to the endometrium and is undoubtedly involved in the maintenance of the delicate balance within the hypothalamic-pituitary-gonadal-endometrial axis. Orchestrated networks of these cytokines also seem to be linked to the steroid hormone signals, an essential feature for maintenance of normal menstrual cycles. Evidence in favour of these emerging concepts is discussed. Major emphasis is placed on interferons, interleukins, tumour necrosis factor, transforming growth factors and colony-stimulating factors.

Induction of a polarized micro-environment by human T cells and interferon-gamma in three-dimensional spheroid cultures of human endometrial epithelial cells

Expression of human leukocyte antigen (HLA)-DR molecules and proliferation of epithelium in human endometrium are polarized. We have suggested that the induction of such a polarized micro-environment is T cell and interferon (IFN)-gamma dependent. The present study was designed to demonstrate the induction of such a micro-environment around T cells and around the source of IFN-gamma. Spheroids reminiscent of endometrial glands were formed by allowing three-dimensional aggregation of endometrial epithelial cells of a cloned HLA-DR negative endometrial carcinoma cell line (ECC1) over agarose. Both HLA-DR expression and inhibition of proliferation were found to be directly dependent on the dose of IFN-gamma that was allowed to diffuse in the agarose beneath the spheroids. To show that the interaction of the epithelial cells with activated T cells also induces HLA-DR molecules in a paracrine fashion in the epithelial cells, ECC1 spheroids were co-cultured with increasing numbers of allogeneic peripheral blood T cells for various time-intervals. T cells bound to the ECC1 cells, and became activated as indicated by the expression of interleukin (IL)-2 receptor and HLA-DR molecules. A focal HLA-DR expression became apparent in the ECC1 cells adjacent to the T cells. As the number of T cells added to spheroid cultures was increased, a concomitant increase in the number of HLA-DR positive ECC1 cells occurred and HLA-DR immunoreactivity was enhanced in each cell. There was a corresponding decrease in the proliferation of the ECC1 cells in T cell-ECC1 spheroid co-cultures. Based on these data, we suggest that activation of T cells is associated with the induction of HLA-DR expression and inhibition of proliferation in a paracrine fashion in the epithelial cells and may be responsible for the creation of a polarized micro-environment in vivo.

Cytokine expression in human endometrium throughout the menstrual cycle

Recent evidence suggests that diverse endometrial functions may be regulated by cytokines. In this report, the presence of protein and mRNA of cytokines were studied in human endometrium throughout the menstrual cycle. The presence of the interleukin-1 (IL-1) alpha, interleukin-1 (IL-1) beta, interleukin receptor antagonist (IRAP), interleukin-6 (IL-6) and transforming growth factor (TGF)-alpha proteins were demonstrated by immunohistochemical staining. The IL-1 alpha and TGF-alpha proteins were strongly expressed and IL-1 beta protein was weakly expressed in all the cells in the stroma as well as epithelial cells. IRAP was markedly expressed in the cells with morphological features of macrophages scattered in the stroma, and the expression of IL-6 protein was predominant in the endometrial epithelium. Diffuse cytoplasmic expression of IL-1 alpha in endometrial epithelium during the proliferative phase contrasted markedly with its enhanced luminal expression during the secretory phase of the menstrual cycle. In addition, the presence of the mRNA of these cytokines in endometrium was established throughout the entire menstrual cycle by reverse transcription-polymerase chain reaction (RT-PCR). Abundant expression of cytokines in human endometrium emphasizes the significant roles that cytokines play in cell-cell interactions and in regulating endometrial functions.

Tumor necrosis factor-alpha messenger ribonucleic acid and protein in human endometrium

Although previous studies have shown that the tumor necrosis factor-alpha (TNF) gene is expressed in pregnancy decidua, it has not been determined whether this gene is transcribed or translated in the endometrium prior to implantation. To address this question and to identify cells expressing the TNF gene, samples of normal cycling human endometria were tested for TNF mRNA by in situ hybridization using a biotinylated antisense RNA probe, and the corresponding protein was localized in the same tissues by immunocytochemistry with a monoclonal antibody to TNF. Both TNF message and protein were identified in the endometrium throughout the menstrual cycle, and the same types of cells that contained transcripts also contained protein. As judged by the intensities of the hybridization signals, TNF mRNA increased during the proliferative phases, declined in the early secretory phase, and again rose during mid-to-late secretory phases, suggesting positive associations with levels of female sex hormones that show similar cyclic fluctuations. At the initiation of the cycle, transcripts were primarily localized to glandular epithelial cells whereas by the midproliferative phase, message was also present in stromal cells. Hybridization signals were consistently more intense in functionalis-region than in basalis-region stromal cells, and were frequently stronger in basalis-region glandular epithelia than in functionalis-region glands. These observations document that the TNF gene is expressed in normal cycling endometria, suggest that ovarian hormones may regulate TNF gene transcription, and identify differences in specific endometrial compartments. The findings are also consistent with the postulate that TNF is a local mediator of cellular communications in the human endometrium.

Patterns of expression of integrin molecules in human endometrium throughout the menstrual cycle

A heterogeneous group of cells interact with each other and with the surrounding matrix to form the complex structure of human endometrium. Since the integrin superfamily of molecules is involved in the cell-cell and cell-matrix interactions, this study was designed to screen, in situ, the cellular distribution of CDW49a-f molecules in human endometrium throughout the menstrual cycle. The integrin molecules were localized by immunohistochemistry using monoclonal antibodies. Glandular epithelium expressed all integrin molecules. With the exception of CDW49d (alpha 4 beta 1), surface epithelium also expressed all these molecules. Endothelial cells were positive for all integrin molecules except CDW49a (alpha 1 beta 1). Endometrial lymphoid cells were positively immunostained for CDW49a, d and e (alpha 5 beta 1) and were negative for CDW49b (alpha 2 beta 1), CDW49c (alpha 3 beta 1) and CDW49f (alpha 6 beta 1). Regional differences in the expression of integrin molecules were observed. As compared to the functionalis epithelium, basalis epithelium characteristically exhibited higher expression of CDW49a, d and e. Two integrins in endometrium, CDW49a and d exhibited changes related to the menstrual cycle. CDW49a, which was not expressed in glandular epithelial cells in the proliferative phase, was strongly expressed in these cells after ovulation and its expression was diminished in the late secretory phase. This molecule was not expressed in the stromal cells, however, predecidual cells characteristically expressed this molecule in the late secretory phase. CDW49d was only expressed in the glandular epithelial cells in the mid-proliferative to mid-secretory phases.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of HLA-DR expression in endometrial epithelial cells by endometrial T-cells: potential regulatory role of endometrial T-cells in vivo

Endometrial epithelial cells express HLA-DR molecules of the major histocompatibility complex in vivo adjacent to aggregates of T-cells in the endometrial stroma. To test whether HLA-DR expression on endometrial epithelium is mediated by T-cells, endometrial T-cells were isolated from human endometrium by the sheep red blood cell rosetting technique. In contrast to the resting T-cells from peripheral blood and similar to the peripheral blood T-cells activated with Concanavalin-A, endometrial T-cells formed colonies in vitro. Direct addition of the endometrial T-cells to epithelial cell cultures derived from autologous glands induced both morphological changes as well as HLA-DR molecules in the epithelial cells. The intensity of the immunostained HLA-DR molecules in the epithelial cells as well as the percentages of the HLA-DR-positive epithelial cells correlated with the number of T-cells added to the epithelial cell cultures. T-Cells were bound to the HLA-DR-positive epithelial cells as single cells or aggregates, and they were not found bound to the HLA-DR-negative epithelial cells. The supernatant of the endometrial T-cells induced expression of HLA-DR molecules and morphological changes in cultures of HLA-DR-negative epithelial cells. This expression could be inhibited by a neutralizing antiserum to interferon-gamma. These findings are consistent with the hypothesis that endometrial T-cells are activated and suggest that the expression of HLA-DR molecules in glandular epithelium in vivo is mediated by the interferon-gamma secreted by the endometrial T-cells.

Expression of colony-stimulating factor-1 (CSF-1) messenger RNA in human endometrial glands during the menstrual cycle: molecular cloning of a novel transcript that predicts a cell surface form of CSF-1

Colony-stimulating factor-1 (CSF-1) has been primarily characterized as a hematopoietic growth factor required for the proliferation and differentiation of monocytic cells. Recent immunohistological observations have shown that this growth factor is also synthesized by the glandular epithelial cells of the pregnant human endometrium and by first trimester human trophoblasts. In the present study endometrial glands were purified from nonpregnant human endometria collected through the menstrual cycle and examined for CSF-1 mRNA expression. The two major mRNAs (4.0 and 3.0 kilobases in length) detected in midproliferative and midsecretory phases differed in the size of the exon 6 and coded, respectively, for a secreted and a cell surface form of CSF-1. The 3.0-kilobase transcript represented a novel CSF-1 mRNA species that was molecularly cloned and sequenced. These data raise the possibility that CSF-1 may be involved in both distant and cell to cell regulatory pathways of cell proliferation and differentiation in the human endometrium.

Ubiquitous expression of TNF-alpha/cachectin immunoreactivity in human endometrium

Emerging evidence suggests that cytokines play significant roles as intercellular communication signals in human endometrium. In the present report, an immunohistochemical staining method and tumor necrosis factor-alpha (TNF-alpha) specific polyclonal antibody was used to identify potential in vivo sources of this cytokine in human endometrium. During the proliferative and early secretory phases of the menstrual cycle, glandular epithelium was distinctly free of any immunoreactive product. With the emergence of mid- and particularly late-secretory phases, however, some glandular epithelial cells started to express TNF-alpha. In the late secretory phase, glands exhibiting strong staining were adjacent to those that were negative for TNF-alpha or only sparingly contained positively immunostained cells. Remarkably, the glandular epithelium constituted a major source of enhanced expression of TNF-alpha during gestation. In the proliferative phase, virtually all stromal cells strongly expressed TNF-alpha, and in the secretory phase, some variability of staining could be observed among various stromal cells. In gestational endometria, decidual cells and in all endometria, endothelial cells strongly expressed immunoreactivity for TNF-alpha. These data demonstrate that various constituents of endometria are constitutively primed to express TNF-alpha and that this expression is distinctly associated with the changes in endometrium that are compelled by hormonal stimuli.