The expression of Smads in human endometrium and regulation and induction in endometrial epithelial and stromal cells by transforming growth factor-beta

Human endometrium expresses TGF-beta and TGF-beta receptors where they regulate several endometrial biological activities implicated in embryo implantation, irregular bleeding, endometriosis, and cancer. In the present study, we determined the expression of Smads, intracellular signals that mediate TGF-beta receptors signals from the cell surface to the nucleus, in the endometrium as well as isolated endometrial epithelial (EEC) and stromal (ESC) cells. We also determined whether TGF-beta regulates the expression Smads and activates Smad3 in these cells and endometrial surface epithelial cell line (HES). Using semiquantitative RT-PCR, Western blot analysis, and immunohistochemistry, we found that endometrium, EEC, ESC, and HES express Smad3, -4, and -7 mRNA and protein and contain phosphorylated Smad3 (pSmad3). Smads and pSmad3 were localized in the epithelial and stromal cells with cytoplasmic/nuclear localization. TGF-beta in a dose- and time-dependent manner increased the expression of Smads mRNA and protein, the rate of pSmad3 activation, and Smad3 translocation into the nucleus in ESC and HES. The effect of TGF-beta on pSmad3 induction was, in part, abrogated by the pretreatment of HES and ESC with TGF-beta type II receptor antisense oligonucleotides. We conclude that human endometrium expresses the necessary components of Smad signaling pathway, whose expression and induction in endometrial epithelial and stromal cells are regulated by TGF-beta.     

Leptin upregulates beta3-integrin expression and interleukin-1beta, upregulates leptin and leptin receptor expression in human endometrial epithelial cell cultures

Human endometrium and endometrial epithelial cells (EECs) either cultured alone or cocultured with human embryos express leptin and leptin receptor. This study compares the effect of leptin with that of interleukin-1β (IL-1β) on the expression of β3-EEC integrin, a marker of endometrial receptivity. Both cytokines increased the expression of β3-EEC at concentrations in the range of 0.06–3 nM; however, leptin exhibited a significantly greater effect than IL-1β. We also determined the regulatory effects of IL-1β on leptin secretion and on the expression of leptin and leptin receptor at the protein level in both EEC and endometrial stromal cell (ESC) cultures. In EEC cultures, IL-1β upregulated secretion of leptin and expression of both leptin and leptin receptors. No effect of IL-1β was found in the ESC cultures. However, leptin exhibited marginal upregulation of leptin receptor. The upregulation of β3-integrin and leptin/leptin receptor expression by IL-1β in EEC cultures indicates that both cytokines may be implicated in embryonic-maternal cross-talk during the early phase of human implantation. Our present data also raise the possibility that leptin is an endometrial molecular effector of IL-1β action on β3-integrin upregulation. Thus, a new role for leptin in human reproduction as an autocrine/paracrine regulator of endometrial receptivity is proposed.     

Hepatocyte growth factor/Met system promotes endometrial and endometriotic stromal cell invasion via autocrine and paracrine pathways

Endometrial stromal cells reportedly have a role in the initial invasion of endometrial tissue into the peritoneum. Hepatocyte growth factor (HGF), which is a ligand for the c-met protooncogene product (Met), stimulates proliferation and invasion of a large number of cells. In this study we investigated the role of the HGF/Met system in the pathogenesis of endometriosis. HGF concentrations in the peritoneal fluid of patients with endometriosis were significantly higher than in those without endometriosis and correlated positively with revised American Society of Reproductive Medicine scores. We showed that the peritoneum and endometriotic stromal cells may be major sources of HGF in peritoneal fluid. Endometrial and endometriotic stromal cells expressed the Met receptor, which was activated by endogenous and exogenous HGF. HGF enhanced stromal cell proliferation and invasion. We also demonstrated that the HGF-stimulated stromal cell invasion was due in part to the induction of urokinase-type plasminogen activator, a member of the extracellular proteolysis system. In conclusion, the HGF/Met system is involved in the pathogenesis of endometriosis by promoting stromal cell proliferation and invasion of shed endometria and endometrial lesions via autocrine and paracrine pathways.     

Regulation of proliferation, motility, and contractility of human endometrial stromal cells by platelet-derived growth factor

To evaluate the involvement of platelet-derived growth factor (PDGF) isoforms (PDGF-AlphaAlpha, PDGF-AB, and PDGF-BB) on endometrial tissue remodeling during the perimenstrual period, we investigated the effects of PDGF on the proliferation, motility, invasiveness, and contractility of cultured human endometrial stromal cells (ESC) using a modified methylthiazoletetrazolium assay, a 5-bromo-2'-deoxyuridine incorporation assay, an in vitro wound repair assay, a chemotactic migration assay, a Transwell invasion assay, and a collagen gel contraction assay. All three isoforms of PDGF significantly enhanced the cell proliferation, DNA synthesis, and in vitro wound repair of ESC. Chemotactic migration assay, Transwell invasion assay, and collagen gel contraction assay demonstrated that the PDGF isoforms significantly stimulated both the motility of ESC and the collagen gel contractility of ESC. PDGF-BB showed the strongest effects on these cellular functions of ESC. The present study suggested that PDGF isoforms may promote endometrial tissue repair by enhancing the proliferation and expansion of ESC, stimulating ESC migration, and stimulating the contraction of the collagen gel matrix by ESC. By regulating ESC function during the perimenstrual period, PDGF may help to protect the endometrium from extensive fibrosis and scarring.     

In situ detection of TGF betas, TGF beta receptor Ⅱ mRNA and telomerase activity in rat cholangiocarcinogenesis

AIM: Initial report on the in situ examination of the mRNA expression of transforming growth factor betas (TGFβs),TGFβ type Ⅱ receptor (TβRII) and telomerase activity in the experimental rat liver tissue during cholangiocarcinogenesis.METHODS: Rat liver cholangiocarcinogenesis was induced by 3'-methyl 4-dimethylazobenzene (3'Me-DAB). In situhybridization was used to examine the TGFβs) and TGFβ type Ⅱ receptor (TβRⅡ) mRNA, in situ TRAP was used to check the telomerase activity in the tissue samples.RESULTS: There was no TGFβs, TβRⅡ mRNA expression or telomerase activity in the control rat cholangiocytes. The expression of TGFβ1, TβRⅡ was increased in regenerative,hyperplastic, dysplastic cholangiocytes and cholangiocarcinoma (CC) cells. The expression of TGFβ2 mRNA was observed in only a part of hyperplastic, dysplastic cholangiocytes. TGFβ3expression was very weak, only in hyperplastic lesion. There was positive telomerase activity in the regenerative,hyperplastic, dysplastic cholangiocytes, and CC cells. Stroma fibroblasts of these lesions also showed positive TGFβs, TβRⅡ mRNA expression and telomerase activity.CONCLUSION: There were TGFβs, TβRⅡ expression and telomerase activity in hyperplastic, dysplastic cholangiocytes,cholangiocarcinoma cells as well as in stroma fibroblasts during cholangiocarcinogenesis. Their expression or activity is important in cholangiocarcinogenesis andstroma formation.     

Cooperation of the ErbB2 receptor and transforming growth factor beta in induction of migration and invasion in mammary epithelial cells

MCF10A mammary epithelial cells form growth-arrested structures when cultured in three-dimensional basement membrane gels. Activation of the receptor tyrosine kinase ErbB2 induces formation of proliferative structures that share properties with noninvasive early stage lesions. We conducted a genetic screen to identify cDNAs that can cooperate with ErbB2 to induce migration in these cells, with the hypothesis that they would represent candidate "second hits" in the development of invasive breast carcinomas. We found that expression of transforming growth factor (TGF)beta1 and TGFbeta3 in cells expressing activated ErbB2 induces migration in transwell chambers and invasive behavior in both basement membrane cultures and invasion chambers. The ability of ErbB2 to cooperate with TGFbeta correlated with sustained, elevated activation of extracellular signal-regulated kinase (Erk)-mitogen-activated protein kinase. Pharmacological reduction of Erk activity inhibited the cooperative effect of TGFbeta and ErbB2 on migration and expression of activated Erk kinase was sufficient to cooperate with TGFbeta to induce migration and invasion, suggesting that sustained Erk activation is critical for ErbB2/TGFbeta cooperation. In addition, we show that costimulation of ErbB2 and TGFbeta induces autocrine secretion of factors that are sufficient to induce migration, but not invasion, by means of both epidermal growth factor receptor-dependent and -independent processes. These results support the role of TGFbeta as a pro-invasion factor in the progression of breast cancers with activated ErbB2 and suggest that activation of the Erk and epidermal growth factor receptor pathways are key in mediating these events.     

Resemblance of osteophytes in experimental osteoarthritis to transforming growth factor β–induced osteophytes: Limited role of bone morphogenetic protein in early osteoarthritic osteophyte formation

Objective

Osteoarthritis (OA) is characterized by cartilage damage, synovial fibrosis, and osteophyte formation. Both transforming growth factor β (TGFβ) and bone morphogenetic protein 2 (BMP‐2) can induce the formation of osteophytes during OA, but their specific role in this process is unclear. The purpose of this study was to investigate the respective contributions of TGFβ and BMP‐2 to OA.

Methods

Mouse knee joints injected with adenovirus (Ad‐TGFβ or Ad‐BMP‐2) were compared histologically with knee joints from murine models of OA (joints injected with collagenase and joints from STR/Ort mice with spontaneous OA). To further investigate the role of BMP during osteophyte formation, adenovirus Ad‐Gremlin was injected into knee joints that had previously been injected with Ad‐TGFβ or collagenase.

Results

BMP‐2 induced early osteophytes, which bulged from the growth plates on the femur and grew on top of the patella, whereas TGFβ induced early osteophyte formation on the bone shaft beneath the collateral ligament on the femur as well as on top of the patella. The pattern of osteophyte formation during experimental OA closely resembled that of TGFβ‐induced osteophyte formation, but differed from the pattern induced by BMP‐2. Ad‐Gremlin proved to be able to totally block BMP‐2–induced osteophyte formation. However, blocking BMP activity inhibited neither TGFβ‐induced nor experimental OA–associated osteophyte formation.

Conclusion

Our findings demonstrate that the role of BMP during the onset of TGFβ‐induced and experimental OA–induced osteophyte formation is limited. The latter finding does not rule out a role of BMP during osteophyte maturation.

     

Neuregulin/erythroblastic leukemia viral oncogene homolog 3 autocrine loop contributes to invasion and early recurrence of human hepatoma

Intrahepatic metastasis is the primary cause of the high recurrence and poor prognosis of human hepatocellular carcinoma (HCC). However, neither its molecular mechanisms nor markers for its prediction before hepatectomy have been identified. We recently revealed up-regulation of erythroblastic leukemia viral oncogene homolog 3 (ERBB3) in human HCC. Here we examined the clinical and biological significance of ERBB3 in HCC. Up-regulation of ERBB3 in HCC was strongly associated with male gender (P < 0.001), chronic hepatitis B (P = 0.002), microscopic vascular invasion (P = 0.034), early recurrence (P = 0.003), and worse prognosis (P = 0.004). Phosphorylated ERBB3 and its ligands [neuregulins (NRGs)] were detected in both HCC tissues and cells. Phosphorylation of ERBB3 could be induced by conditioned media of HCC cells and abolished by the pretreatment of conditioned media with anti-NRG antibodies or by the silencing of the endogenous NRG expression of the donor HCC cells. Human epidermal growth factor receptor 2 was required for ERBB3 phosphorylation. The downstream phosphoinositide 3-kinase/v-akt murine thymoma viral oncogene homolog pathways were primarily elicited by NRG1/ERBB3 signaling, whereas the mitogen-activated protein kinase/extracellular signal-regulated kinase pathways were elicited by both epidermal growth factor/epidermal growth factor receptor and NRG1/ERBB3 signaling. The activation and silencing of ERBB3-dependent signaling had potent effects on both the migration and invasion of HCC cells, but neither had significant effects on the proliferation of HCC cells, tumor formation, or tumor growth in vitro and in vivo. CONCLUSION: The constitutive activation of ERBB3-dependent signaling via the NRG1/ERBB3 autocrine loop plays a crucial role in the regulation of cell motility and invasion, which contribute to intrahepatic metastasis and early recurrence of HCC. ERBB3 is a marker for the prediction of intrahepatic metastasis and early recurrence. ERBB3-dependent signaling is a candidate target for the treatment of microscopic vascular invasion and for the prevention of HCC recurrence.     

Progesterone resistance in endometriosis: link to failure to metabolize estradiol

Endometriosis is the most common cause of pelvic pain and affects an estimated 5 million women in the US. The biologically active estrogen estradiol (E2) is the best-defined mitogen for the growth and inflammation processes in the ectopic endometriotic tissue that commonly resides on the pelvic organs. Progesterone and progestins may relieve pain by limiting growth and inflammation in endometriosis but a portion of patients with endometriosis and pelvic pain do not respond to treatment with progestins. Moreover, progesterone-induced molecular changes in the eutopic (intrauterine) endometrial tissue of women with endometriosis are either blunted or undetectable. These in vivo observations are indicative of resistance to progesterone action in endometriosis. The molecular basis of progesterone resistance in endometriosis may be related to an overall reduction in the levels of progesterone receptors (PRs) and the lack of the PR isoform named progesterone receptor B (PR-B). In normal endometrium, progesterone acts on stromal cells to induce secretion of paracrine factor(s). These unknown factor(s) act on neighboring epithelial cells to induce the expression of the enzyme 17beta-hydroxysteroid dehydrogenase type 2 (17beta-HSD-2), which metabolizes the biologically active estrogen E2 to estrone (E1). In endometriotic tissue, progesterone does not induce epithelial 17beta-HSD-2 expression due to a defect in stromal cells. The inability of endometriotic stromal cells to produce progesterone-induced paracrine factors that stimulate 17beta-HSD-2 may be due to the lack of PR-B and very low levels of progesterone receptor A (PR-A) observed in vivo in endometriotic tissue. The end result is deficient metabolism of E2 in endometriosis giving rise to high local concentrations of this local mitogen. The cellular and molecular mechanisms underlying progesterone resistance and failure to metabolize E2 in endometriosis are reviewed.     

Targeting Raf-1 gene expression by a DNA enzyme inhibits juvenile myelomonocytic leukemia cell growth

Juvenile myelomonocytic leukemia (JMML) is an aggressive childhood disorder with few therapeutic options. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha) promote JMML cell growth. A hyperactive function of the ras oncogene is a hallmark of JMML. We therefore targeted the protein kinase Raf-1 downstream of Ras using a DNA enzyme that degrades mRNA-Raf-1. Western blots of JMML cell lysates revealed phosphorylated Raf-1 protein, indicating constitutive activation. Addition of GM-CSF, but not TNF-alpha, increased phosphorylation of both Raf-1 and the mitogen-activated protein kinases (MAPKs) JNK-1 and ERK-1. Depletion of Raf-1 protein markedly impaired activation of MAPKs, induced substantial inhibition of JMML cell colony formation, and virtually abolished GM-CSF hypersensitivity in JMML cells. Exogenous TNF-alpha, but not GM-CSF, restored colony formation of JMML cells pretreated with the enzyme. We could not detect any effect of the enzyme on the proliferation of normal bone marrow cells, indicating its specificity and potential safety. When immunodeficient mice engrafted with JMML cells were treated continuously with the enzyme via a peritoneal osmotic mini-pump for 4 weeks, a profound reduction in the JMML cell numbers in the recipient murine bone marrows was found. We conclude that GM-CSF is a chief regulator of JMML growth and exerts its proleukemic effects primarily via the Ras/Raf-1 signaling cascade. TNF-alpha plays a permissive role, being dependent upon GM-CSF to induce JMML cell proliferation. The DNA enzyme efficiently catabolized mRNA-Raf-1 with subsequent inhibition of JMML cell growth, suggesting its potential as a mechanism-based therapy in this fatal leukemia.     

老年骨关节炎患者关节软骨和滑膜中转化生长因子β及受体和金属蛋白酶组织抑制物的研究

目的 探讨骨关节炎（OA）患者关节软骨和滑膜中转化生长因子β（TGFβ1）、转化生长因子β受体（TGFβR）和金属蛋白酶组织抑制物－1（TIMP－1）变化及其与OA发病的关系。方法 采用免疫组化方法检测23例老年OA患者及3例外伤患者正常关节软骨和滑膜TGFβ1、转化生长因子βI类受体（TGFβRI）、转化生长因子βⅡ类受体（TGFβRⅡ）和TIMP－1的分布和阳性程度。结果 OA患者中14例关节软骨和16例滑膜TGFβ1染色呈阳性或弱阳性,14例关节软骨和15例滑膜TIMP－1染色呈弱阳性,全部OA患者关节软骨和滑膜TGFβRI和TGFβRⅡ染色呈强阳性。阳性细胞包括软骨细胞、滑膜衬里细胞、滑膜下层的血管内皮细胞和间质巨噬细胞等。结论 老年OA患者关节软骨和滑膜中TGFβ1、TGFβ及TIMP－1的变化可能与OA发病有一定的关系。     

Endometrial stromal cells undergoing decidualization down-regulate their properties to produce proinflammatory cytokines in response to interleukin-1 beta via reduced p38 mitogen-activated protein kinase phosphorylation

The decidualized endometrium plays a role in regulating trophoblast invasion for successful implantation and maintenance of pregnancy. IL-1 beta, a proinflammatory cytokine, has been suggested to play a role in this process. Recently, several lines of evidence indicate the importance of p38 MAPK in various inflammatory responses. We investigated whether endometrial stromal cells (ESC) change their inflammatory responses to IL-1 beta as related to p38 MAPK phosphorylation during the process of decidualization. ESC were decidualized by the treatment with progesterone for 9 d, as determined as such by an increase in the production of prolactin and cAMP by the cells. Whereas IL-1 beta increased the production of IL-6, IL-8, and monocyte chemotactic protein-1, and expression of cyclooxygenase-2 mRNA in ESC cultured without treatment, the stimulatory effects of IL-1 beta were reduced in the decidualized cells. Treatment with SB202190, a p38 MAPK inhibitor, also reduced the stimulatory effects of IL-1 beta in nondecidualized ESC. P38 MAPK phosphorylation was increased by IL-1 beta in nondecidualized ESC, whereas the IL-1 beta-induced increase was suppressed in the decidualized cells. Treatment with 8-bromo-cAMP reduced IL-1 beta-induced phosphorylation of p38 MAPK in nondecidualized ESC. In contrast, treatment with H89, a protein kinase A inhibitor, reversed a reduction in IL-1 beta-induced p38 MAPK phosphorylation in the decidualized cells. In summary, decidualization seems to be a process during which endometrial cells diminish their response to IL-1 beta, a known key factor for implantation, leading to the down-regulation of inflammation-like events, which may be relevant to controlled trophoblast invasion. The altered property of decidualized cells is thought to be caused by attenuation of IL-1 beta-induced p38 MAPK phosphorylation in a way that involves the activation of the cAMP/protein kinase A pathway.     

Mechanical stretch stimulates interleukin-8 production in endometrial stromal cells: possible implications in endometrium-related events

Uterine movement is suggested to play roles in various events related to the uterus. In view of the current concept underscoring the biological implications of mechanical stretch, we speculated that the mechanical stretch exerted by uterine movement might stimulate the production of biochemical mediators in endometrial cells and contribute to inflammation-associating processes, such as menstruation and endometriosis. To address the possible effects of mechanical stretch in the endometrium, endometrial stromal cells (ESC) were cultured on flexible-bottomed culture plates, and cyclic stretch (25% elongation) was applied in serum-free conditions at a rate of two cycles per minute using a computer-operated cell tension system. IL-8 concentrations in the conditioned medium were measured using ELISA, and IL-8 mRNA expression in ESC was measured by RT-PCR. Cyclic stretch increased the secretion of IL-8 from ESC. The increase in IL-8 secretion was inhibited by PD98059, an inhibitor of extracellular signal-regulated kinase 1/2. The increase was also inhibited by progesterone. In addition, the conditioned medium of ESC cultured with cyclic stretch stimulated the mRNA expression of IL-8 in ESC cultured under stationary conditions. These findings imply that uterine movement has an impact on endometrium-related physiology and pathology by stimulating the production of a biochemical mediator(s) in the endometrium.     

Heparin-binding epidermal growth factor and its receptors mediate decidualization and potentiate survival of human endometrial stromal cells

Heparin-binding epidermal growth factor (HB-EGF) has pleiotropic biological functions in many tissues, including those of the female reproductive tract. It facilitates embryo development and mediates implantation and is thought to have a function in endometrial receptivity and maturation. The mature HB-EGF molecule manifests its activity as either a soluble factor (sol-HB-EGF) or a transmembrane precursor (tm-HB-EGF) and can bind two receptors, EGFR and ErbB4/HER4. In this study, we identify factors that modulate expression of HB-EGF, EGFR, and ErbB4 in endometrial stromal cells in vitro. We demonstrate that levels of sol- and tm-HB-EGF, EGFR, and ErbB4 are increased by cAMP, a potent inducer of decidualization of the endometrial stroma. We also show that production of sol- and tm-HB-EGF is differentially modulated by TNF alpha and TGF beta. Our data suggest that HB-EGF has a function in endometrial maturation in mediating decidualization and attenuating TNF alpha- and TGF beta-induced apoptosis of endometrial stromal cells.     

Cyclooxygenase-2 regulates survival, migration, and invasion of human endometriotic cells through multiple mechanisms

Endometriosis is a debilitating disease characterized by the presence of functional endometrial glandular epithelium and stroma outside the uterine cavity that affects up to 20% of women of child-bearing age. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme in the biosynthesis of prostaglandin E(2) (PGE(2)), is highly expressed in endometriotic tissues and results in increased concentrations of peritoneal PGE(2) in women. In this study, we determined the expression of COX-2 protein in ectopic and eutopic endometria in humans and the role of COX-2 in endometriotic cell survival, migration, and invasion in humans. Our results indicate that COX-2 protein is abundantly expressed in ectopic endometria compared with eutopic endometria. Comparatively, expression of COX-2 protein is higher in eutopic endometria from women with endometriosis compared with women without endometriosis. Inhibition of COX-2 decreases survival, migration, and invasion of endometriotic cells that are associated with decreased production of PGE(2). Cell growth inhibitory effects of COX-2 inhibition/silencing are mediated through nuclear poly (ADP-ribose) polymerase-mediated apoptosis. Cell motility and invasion inhibitory effects of COX-2 inhibition/silencing are mediated through matrix metalloproteinase-2 and -9 activities. Interestingly, effects of COX-2 inhibition is more profound in endometriotic epithelial than in stromal cells. Furthermore, inhibition of COX-2 affects invasion rather than migration of endometriotic epithelial and stromal cells. It is the first evidence showing that inhibition of COX-2 decreases endometriotic epithelial and stromal cell survival, migration, and invasion in humans. Our results support the emerging concept that COX-2/PGE(2) promotes the pathophysiology and pathogenesis of endometriosis in humans.     

Hormone and growth factor signaling in endometrial renewal: role of stem/progenitor cells

The human endometrium is a dynamic remodeling tissue undergoing more than 400 cycles of regeneration, differentiation and shedding during a woman's reproductive years. The co-ordinated and sequential actions of estrogen and progesterone direct these major remodeling events preparing a receptive endometrium for blastocyst implantation on a monthly basis. Adult stem/progenitor cells are likely responsible for endometrial regeneration. Functional approaches have been used to identify candidate endometrial stem/progenitor cells, as there are no specific stem cell markers. Rare populations of human endometrial epithelial and stromal colony-forming cells/units (CFU) and side population (SP) cells have been identified. Several growth factors are required for CFU activity: epidermal growth factor (EGF), transforming growth factor alpha (TGFalpha) and platelet-derived growth factor BB (PDGF-BB) for both epithelial and stromal CFU, and basic fibroblast growth factor (bFGF) for stromal, but not epithelial CFU. A sub-population of human endometrial stromal cells with mesenchymal stem cell properties of CFU activity and multilineage (fat, muscle, cartilage and bone) differentiation have been isolated by their co-expression of CD146 and PDGF-receptor beta. Candidate epithelial and stromal stem/progenitor cells have been identified in mouse endometrium as rare label retaining cells (LRCs) in the luminal epithelium and as perivascular cells at the endometrial-myometrial junction, respectively. While epithelial and most stromal LRC do not express estrogen receptor alpha (Esr1), they rapidly proliferate on estrogen stimulation, most likely mediated by neighbouring Esr1-expressing niche cells. It is likely that these newly identified endometrial stem/progenitor cells may play key roles in the development of gynecological diseases associated with abnormal endometrial proliferation such as endometriosis and endometrial cancer.