Inducible nitric oxide synthase in tangle-bearing neurons of patients with Alzheimer's disease.

In Alzheimer's disease (AD), affected neurons accumulate beta amyloid protein, components of which can induce mouse microglia to express the high-output isoform of nitric oxide synthase (NOS2) in vitro. Products of NOS2 can be neurotoxic. In mice, NOS2 is normally suppressed by transforming growth factor beta 1 (TGF-beta 1). Expression of TGF-beta 1 is decreased in brains from AD patients, a situation that might be permissive for accumulation of NOS2. Accordingly, we investigated the expression of NOS2 in patients with AD, using three monospecific antibodies: a previously described polyclonal and two new monoclonal antibodies. Neurofibrillary tangle-bearing neurons and neuropil threads contained NOS2 in brains from each of 11 AD patients ranging in age from 47 to 81 years. NOS2 was undetectable in brains from 6 control subjects aged 23-72 years, but was expressed in small amounts in 3 control subjects aged 77-87 years. Thus, human neurons can express NOS2 in vivo. The high-output pathway of NO production may contribute to pathogenesis in AD.

Smad3 loss confers resistance to the development of trinitrobenzene sulfonic acid-induced colorectal fibrosis.

BACKGROUND: Transforming growth factor-beta (TGF-beta)/Smad3 signalling plays a central role in tissue fibrogenesis, acting as a potent stimulus of extracellular matrix (ECM) protein accumulation. The aim of this study was to evaluate the potential role of Smad3 in the pathogenesis of colonic fibrosis induced by trinitrobenzene sulfonic acid (TNBS) in Smad3 null mice. MATERIALS AND METHODS: Chronic colitis-associated fibrosis was induced in 15 Smad3 null and 13 wild-type mice by intra-rectal administration of TNBS. Each mouse received an incremental dose of TNBS (0.5-1.0 mg per week) over a 6-week period. The colon was excised for macroscopic examination and histological, morphometric and immunohistochemical analyses. For immunohistochemistry, alpha-smooth muscle actin (alpha-SMA), collagen types I-III, TGF-beta1, connective tissue growth factor (CTGF), Smad3, Smad7, and CD3 antibodies were used. RESULTS: At macroscopic examination, the colon of Smad3 wild-type mice appeared significantly harder, thicker and shorter than that of the Smad3 null mice. Of the wild-type mice, 50% presented colonic adhesions and strictures. Histological and morphometric evaluation revealed a significantly higher degree of colonic fibrosis and accumulation of collagen in the Smad3 wild-type compared to null mice, whereas the degree of colonic inflammation did not differ between the two groups of mice. Immunohistochemical evaluation showed a marked increase in CTGF, collagen I-III, TGF-beta and Smad3 staining in the colon of Smad3 wild-type compared to null mice, whereas Smad7 was increased only in null mice. CONCLUSIONS: These results indicate that Smad3 loss confers resistance to the development of TNBS-induced colonic fibrosis. The reduced fibrotic response appears to be due to a reduction in fibrogenic mesenchymal cell activation and ECM production and accumulation. Smad3 could be a novel target for potential treatment of intestinal fibrosis, especially in inflammatory bowel disease.

Accumulation, localization, and compartmentation of transforming growth factor beta during endochondral bone development.

Endochondral bone formation was induced in postnatal rats by implantation of demineralized rat bone matrix. Corresponding control tissue was generated by implanting inactive extracted bone matrix, which did not induce bone formation. At various times, implants were removed and sequentially extracted with guanidine hydrochloride, and then EDTA and guanidine hydrochloride. Transforming growth factor beta (TGF beta) in the extracts was quantitated by a radioreceptor assay. TGF beta was present in demineralized bone matrix before implantation, and the concentration had decreased by 1 d after implantation. Thereafter, TGF beta was undetectable by radioreceptor assay until day 9. From day 9-21 the TGF beta was extracted only after EDTA demineralization, indicating tight association with the mineralized matrix. During this time, the content of TGF beta per milligram soluble protein rose steadily and remained high through day 21. This increased concentration correlated with the onset of vascularization and calcification of cartilage. TGF beta was detected only between days 3-9 in the controls; i.e., non-bone-forming implants. Immunolocalization of TGF beta in bone-forming implants revealed staining of inflammatory cells at early times, followed later by staining of chondrocytes in calcifying cartilage and staining of osteoblasts. The most intense staining of TGF beta was found in calcified cartilage and mineralized bone matrix, again indicating preferential compartmentalization of TGF beta in the mineral phase. In contrast to the delayed expression of TGF beta protein, northern blot analysis showed TGF beta mRNA in implants throughout the sequence of bone formation. The time-dependent accumulation of TGF beta when cartilage is being replaced by bone in this in vivo model of bone formation suggests that TGF beta may play a role in the regulation of ossification during endochondral bone development.

In vitro and in vivo association of transforming growth factor-beta 1 with hepatic fibrosis.

Despite extensive efforts, little progress has been made in identifying the factors that induce hepatic fibrosis. Transforming growth factor-beta (TGF-beta) has been shown to enhance collagen production, therefore its role in hepatic fibrosis was investigated. Treatment of cultured hepatic cells with TGF-beta 1 increased type I procollagen mRNA levels 13-fold due to post-transcriptional gene regulation. When two animal models of hepatic fibrosis, murine schistosomiasis and CCl4-treated rats, were examined, they both exhibited increased levels of TGF-beta 1 gene expression at times that somewhat preceded the increase in collagen synthesis. In contrast, in murine schistosomiasis, mRNA levels of tumor necrosis factor and interleukin-1 peaked early in the fibrogenic process. Immunohistochemical analysis showed TGF-beta 1 to be present in normal mouse liver and to be markedly increased in mice infected with schistosomiasis. TGF-beta 1 appeared in the hepatic parenchyma, primarily in hepatocytes. These findings strongly suggest a role for TGF-beta 1 in a pathophysiological state.

Expression of transforming growth factor-beta 1 in specific cells and tissues of adult and neonatal mice.

We have used immunohistochemical techniques to detect transforming growth factor-beta 1 (TGF-beta 1) in many tissues of adult and neonatal mice. Each of two antibodies raised to the amino-terminal 30 amino acids of TGF-beta 1 selectively stained this molecule in either intracellular or extracellular locations. Strong intracellular staining was found in adrenal cortex, megakaryocytes and other cells of the bone marrow, cardiac myocytes, chondrocytes, renal distal tubules, ovarian glandular cells, and chorionic cells of the placenta. Marked staining of extracellular matrix was found in cartilage, heart, pancreas, placenta, skin, and uterus. Staining was often particularly intense in specialized cells of a given tissue, suggesting unique roles for TGF-beta within that tissue. Levels of expression of mRNA for TGF-beta 1 and its histochemical staining did not necessarily correlate in a given tissue, as in the spleen. The present data lend further support to the concept that TGF-beta has an important role in controlling interactions between epithelia and surrounding mesenchyme.

Transforming growth factor-beta 1: histochemical localization with antibodies to different epitopes.

We have localized transforming growth factor-beta (TGF-beta) in many cells and tissues with immunohistochemical methods, using two polyclonal antisera raised to different synthetic preparations of a peptide corresponding to the amino-terminal 30 amino acids of TGF-beta 1. These two antibodies give distinct staining patterns; the staining by anti-CC(1-30) is intracellular. This differential staining pattern is consistently observed in several systems, including cultured tumor cells; mouse embryonic, neonatal, and adult tissues; bovine fibropapillomas; and human colon carcinomas. The extracellular staining by anti-CC(1-30) partially resembles that seen with an antibody to fibronectin, suggesting that extracellular TGF-beta may be bound to matrix proteins. The intracellular staining by anti-LC(1-30) is similar to that seen with two other antibodies raised to peptides corresponding to either amino acids 266-278 of the TGF-beta 1 precursor sequence or to amino acids 50-75 of mature TGF-beta 1, suggesting that anti-LC(1-30) stains sites of TGF-beta synthesis. Results from RIA and ELISAs indicate that anti-LC(1-30) and anti-CC(1-30) recognize different epitopes of this peptide and of TGF-beta 1 itself.

Role of transforming growth factor-beta in the development of the mouse embryo.

Using immunohistochemical methods, we have investigated the role of transforming growth factor-beta (TGF-beta) in the development of the mouse embryo. For detection of TGF-beta in 11-18-d-old embryos, we have used a polyclonal antibody specific for TGF-beta type 1 and the peroxidase-antiperoxidase technique. Staining of TGF-beta is closely associated with mesenchyme per se or with tissues derived from mesenchyme, such as connective tissue, cartilage, and bone. TGF-beta is conspicuous in tissues derived from neural crest mesenchyme, such as the palate, larynx, facial mesenchyme, nasal sinuses, meninges, and teeth. Staining of all of these tissues is greatest during periods of morphogenesis. In many instances, intense staining is seen in mesenchyme when critical interactions with adjacent epithelium occur, as in the development of hair follicles, teeth, and the submandibular gland. Marked staining is also seen when remodeling of mesenchyme or mesoderm occurs, as during formation of digits from limb buds, formation of the palate, and formation of the heart valves. The presence of TGF-beta is often coupled with pronounced angiogenic activity. The histochemical results are discussed in terms of the known biochemical actions of TGF-beta, especially its ability to control both synthesis and degradation of both structural and adhesion molecules of the extracellular matrix.

Osteoblasts synthesize and respond to transforming growth factor-type beta (TGF-beta) in vitro.

Transforming growth factor-type beta (TGF-beta) has been identified as a constituent of bone matrix (Seyedin, S. M., A. Y. Thompson, H. Bentz, D. M. Rosen, J. M. McPherson, A. Conti, N. R. Siegel, G. R. Gallupi, and K. A. Piez, 1986, J. Biol. Chem. 261:5693-5695). We used both developing bone and bone-forming cells in vitro to demonstrate the cellular origin of this peptide. TGF-beta mRNA was detected by Northern analysis in both developing bone tissue and fetal bovine bone-forming cells using human cDNA probes. TGF-beta was shown to be synthesized and secreted by metabolically labeled bone cell cultures by immunoprecipitation from the medium. Further, TGF-beta activity was demonstrated in conditioned media from these cultures by competitive radioreceptor and growth promotion assays. Fetal bovine bone cells (FBBC) were found to have relatively few TGF-beta receptors (5,800/cell) with an extremely low Kd of 2.2 pM (high binding affinity). In contrast to its inhibitory effects on the growth of many cell types including osteosarcoma cell lines, TGF-beta stimulated the growth of subconfluent cultures of FBBC; it had little effect on the production of collagen by these cells. We conclude that bone-forming cells are a source for the TGF-beta that is found in bone, and that these cells may be modulated by this factor in an autocrine fashion.

Hyperthermia induces expression of transforming growth factor-beta s in rat cardiac cells in vitro and in vivo.

Hyperthermia causes changes in expression of TGF-beta mRNA and protein in cultured cardiac cells, as well as in the heart in vivo. 12 h after hyperthermia, primary cultures of neonatal rat cardiomyocytes show a two- to threefold decreased expression of TGF-beta mRNAs which returns to control levels by 48 h after heat shock. In cultures of cardiac fibroblasts, expression of TGF-beta mRNAs increases 5-25-fold, 12-48 h after heat shock, while fetal bovine heart endothelial cells show little change in TGF-beta expression after hyperthermia. In each case, mRNAs for TGF-beta s 1, 2, and 3 are regulated similarly. Hearts isolated from rats exposed to hyperthermia show an initial 20-fold decrease in TGF-beta 1 and 3 mRNA levels which return to control levels by 24 h and subsequently are elevated two- to threefold above normal 48-72 h after heat shock; there is little change in TGF-beta 2 mRNA. Expression of immunoreactive TGF-beta 1 and 3 protein, localized intracellularly in myocytes, follows the same pattern as the mRNA expression. By 72 h, some myocytes show hyperstaining for TGF-beta 1. Staining for extracellular TGF-beta 1/3 exhibits the opposite time course, being most intense 3-6 h after heat shock and returning to control levels by 48 h. The increase in TGF-beta s after hyperthermia could play a role in mediating the reported cardioprotective effects of heat shock.

Regulation of transforming growth factor-beta 1 expression by the hepatitis B virus (HBV) X transactivator. Role in HBV pathogenesis.

TGF-beta 1 has been implicated in the pathogenesis of liver disease. The high frequency of detection of the hepatitis B virus X (HBx) antigen in liver cells from patients with chronic hepatitis, cirrhosis, and liver cancer suggested that expression of HBx and TGF-beta 1 may be associated. To test this possibility, we examined the expression of TGF-beta 1 in the liver of transgenic mice expressing the HBx gene. We show that the patterns of expression of TGF-beta 1 and Hbx protein are similar in these mice and that HBx activates transcription of the TGF-beta 1 gene in transfected hepatoma cells. The cis-acting element within the TGF-beta 1 gene that is responsive to regulation by Hbx is the binding site for the Egr family of transcription factors. We further show that the Egr-1 protein associates with the HBx protein, allowing HBx to participate in the transcriptional regulation of immediate-early genes. Our results suggest that expression of Hbx might induce expression of TGF-beta 1 in the early stages of infection and raise the possibility that TGF-beta 1 may play a role in hepatitis B virus pathogenesis.

Eosinophils in chronically inflamed human upper airway tissues express transforming growth factor beta 1 gene (TGF beta 1).

Transforming growth factor beta (TGF beta) is a multifunctional protein which has been suggested to play a central role in the pathogenesis of chronic inflammation and fibrosis. Nasal polyposis is a condition affecting the upper airways characterized by the presence of chronic inflammation and varying degrees of fibrosis. To examine the potential role of TGF beta in the pathogenesis of this condition, we investigated gene expression and cytokine production in nasal polyp tissues as well as in the normal nasal mucosa. By Northern blot analysis using a porcine TGF beta 1 cDNA probe, we detected TGF beta 1-specific mRNA in nasal polyp tissues, as well as in the tissue from a patient with allergic rhinitis, but not in the normal nasal mucosa. By the combination of tissue section staining with chromotrope 2R with in situ hybridization using the same TGF beta 1 probe, we found that approximately 50% of the eosinophils infiltrating the polyp tissue express the TGF beta 1 gene. In addition, immunohistochemical localization of TGF beta 1 was detected associated with extracellular matrix as well as in cells in the stroma. These results suggest that in nasal polyposis where eosinophils are the most prevalent inflammatory cell, TGF beta 1 synthesized by these cells may contribute to the structural abnormalities such as stromal fibrosis and basement membrane thickening which characterize this disease.

Transforming growth factor-betas in neurodegenerative disease.

Transforming growth factors-betas (TGF-betas), a family of multifunctional peptide growth factors, affect cells of the central nervous system (CNS). The three mammalian TGF-beta isoforms, TGF-betas 1, 2 and 3, are expressed in adult human brain. Since neuronal degeneration is a defining feature of CNS degenerative diseases, TGF-beta may be important because it can influence neuronal survival. In vitro TGF-beta promotes survival of rat spinal cord motoneurons and dopaminergic neurons. In addition to direct effects on neuronal survival, TGF-beta treatment of cultured astrocytes induces a reactive phenotype. Thus, TGF-beta may also normalize the extracellular matrix environment in degenerative diseases. The expression of TGF-betas change in response to neuronal injury. TGF-beta 1 expression increases in astrocytes and microglia in animal models of cerebral ischemia, while TGF-beta 2 expression increases in activated astroglial cells in human neurodegenerative diseases. TGF-betas protect neurons from a variety of insults. TGF-beta maintains survival of chick telencephalic neurons made hypoxic by treatment with cyanide and decreases the area of infarction when administered in animal models of cerebral ischemia. In vitro TGF-beta protects neurons from damage induced by treatment with beta-amyloid peptide, FeSO4 (induces production of reactive oxygen species), Ca2+ ionophores, glutamate, glutamate receptor agonists and MPTP (toxic for dopaminergic neurons). TGF-beta maintains mitochondrial potential and Ca2+ homeostasis and inhibits apoptosis in neurons. TGF-beta does not prevent neuronal degeneration in a rat model of Parkinson's disease and has yet to be tested in newly developed transgenic mouse models of Alzheimer's disease. TGF-beta is a potent neuroprotective agent which may affect the pathogenesis of neurodegenerative diseases of the CNS.

Transforming growth factor beta 1 induction is associated with transforming growth factors beta 2 and beta 3 down-modulation in 12-O-tetradecanoylphorbol-13-acetate-induced skin hyperplasia.

Acute treatment of mouse skin with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) induces marked epidermal hyperplasia, which is well evident by 24 h and maximal by 48-72 h. These effects are associated with the early induction of transforming growth factor (TGF) beta 1 expression in the epidermis. We show here that, in contrast to TGF-beta 1, TGF-beta 2, and TGF-beta 3, skin expression is significantly down-modulated in response to TPA. TGF-beta 3 RNA levels decreased by 6 h of treatment but returned to normal or even higher levels at later times. The TGF-beta 3 protein could be detected immunohistochemically in both dermis and epidermis in control skins and at early times of TPA treatment. However, at later times, TGF-beta 3 was found only in dermal cells and not in the epidermis. TGF-beta 2 RNA expression was found to be significantly down-modulated by 24 h of TPA treatment and remained low even at later times. Thus, differential control of the 3 TGF-beta isoforms appears to be a likely determinant of normal skin homeostasis and could be at least partially responsible for TPA-induced skin hyperplasia.

Induction of transforming growth factor beta 1 in human breast cancer in vivo following tamoxifen treatment.

We have investigated the ability of tamoxifen to regulate members of the transforming growth factor beta (TGF-beta) family in human breast cancers in vivo. Using immunohistochemical techniques, we find that 3 months of tamoxifen treatment causes a consistent induction of extracellular TGF-beta 1 in breast cancer biopsies, compared with matched pretreatment samples from the same patient. The induced TGF-beta is localized between and around stromal fibroblasts and appears to be derived from these cells. Lower levels of TGF-beta 1,-beta 2, and -beta 3 seen in epithelial cells were not altered by tamoxifen treatment. The increased stromal staining of TGF-beta 1 occurred in estrogen receptor-negative as well as estrogen receptor-positive tumors. These results provide in vivo evidence for a novel, estrogen receptor-independent mechanism of action for tamoxifen, involving the stromal induction of a potent growth inhibitor for epithelial cells.

Deficient transforming growth factor-beta1 activation and excessive insulin-like growth factor II (IGFII) expression in IGFII receptor-mutant tumors.

The insulin-like growth factor II receptor (IGFIIR) gene has been identified as a coding region target of microsatellite instability in human gastrointestinal (GI) tumors. IGFIIR normally has two growth-suppressive functions: it binds and stimulates the plasmin-mediated cleavage and activation of the latent transforming growth factor-beta1 (LTGF-beta1) complex, and it mediates the internalization and degradation of IGFII ligand, a mitogen. We used an immunohistochemical approach to determine whether IGFIIR mutation affected expression of these proteins in GI tumors. Four highly specific antibodies were used: LC(1-30), which recognizes the active form of TGF-beta1; anti-LTGF-beta1, which detects the LTGF-beta1 precursor protein; anti-IGFIIR; and anti-IGFII ligand. Twenty GI tumors either with (6 of 20) or without (14 of 20) known IGFIIR mutation were examined, along with matching normal tissues. Results were statistically significant in the following categories: (a) decreased active TGF-beta1 protein expression in IGFIIR-mutant tumor tissues versus matching normal tissues or IGFIIR-wild-type tumor tissues; (b) increased LTGF-beta1 protein expression in IGFIIR-mutant tumor tissues versus matching normal tissues or IGFIIR-wild-type tumor tissues; and (c) increased IGFII ligand protein expression in IGFIIR-mutant tumor tissues versus matching normal tissues or IGFIIR-wild-type tumor tissues. These data suggest that in genetically unstable GI tumors, mutation of a microsatellite within the coding region of IGFIIR functionally inactivates this gene, causing both diminished growth suppression (via decreased activation of TGF-beta1) and augmented growth stimulation (via decreased degradation of the IGFII ligand).

A novel synthetic oleanane triterpenoid, 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid, with potent differentiating, antiproliferative, and anti-inflammatory activity.

The new synthetic oleanane triterpenoid 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) is a potent, multifunctional molecule. It induces monocytic differentiation of human myeloid leukemia cells and adipogenic differentiation of mouse 3T3-L1 fibroblasts and enhances the neuronal differentiation of rat PC12 pheochromocytoma cells caused by nerve growth factor. CDDO inhibits proliferation of many human tumor cell lines, including those derived from estrogen receptor-positive and -negative breast carcinomas, myeloid leukemias, and several carcinomas bearing a Smad4 mutation. Furthermore, it suppresses the abilities of various inflammatory cytokines, such as IFN-gamma, interleukin-1, and tumor necrosis factor-alpha, to induce de novo formation of the enzymes inducible nitric oxide synthase (iNos) and inducible cyclooxygenase (COX-2) in mouse peritoneal macrophages, rat brain microglia, and human colon fibroblasts. CDDO will also protect rat brain hippocampal neurons from cell death induced by beta-amyloid. The above activities have been found at concentrations ranging from 10(-6) to 10(-9) M in cell culture, and these results suggest that CDDO needs further study in vivo, for either chemoprevention or chemotherapy of malignancy as well as for neuroprotection.

Mammary epithelial cell phagocytosis downstream of TGF-ß3 is characterized by adherens junction reorganization.

After weaning, during mammary gland involution, milk-producing mammary epithelial cells undergo apoptosis. Effective clearance of these dying cells is essential, as persistent apoptotic cells have a negative impact on gland homeostasis, future lactation and cancer susceptibility. In mice, apoptotic cells are cleared by the neighboring epithelium, yet little is known about how mammary epithelial cells become phagocytic or whether this function is conserved between species. Here we use a rat model of weaning-induced involution and involuting breast tissue from women, to demonstrate apoptotic cells within luminal epithelial cells and epithelial expression of the scavenger mannose receptor, suggesting conservation of phagocytosis by epithelial cells. In the rat, epithelial transforming growth factor-ß (TGF-ß) signaling is increased during involution, a pathway known to promote phagocytic capability. To test whether TGF-ß enhances the phagocytic ability of mammary epithelial cells, non-transformed murine mammary epithelial EpH4 cells were cultured to achieve tight junction impermeability, such as occurs during lactation. TGF-ß3 treatment promoted loss of tight junction impermeability, reorganization and cleavage of the adherens junction protein E-cadherin (E-cad), and phagocytosis. Phagocytosis correlated with junction disruption, suggesting junction reorganization is necessary for phagocytosis by epithelial cells. Supporting this hypothesis, epithelial cell E-cad reorganization and cleavage were observed in rat and human involuting mammary glands. Further, in the rat, E-cad cleavage correlated with increased γ-secretase activity and ß-catenin nuclear localization. In vitro, pharmacologic inhibitors of γ-secretase or ß-catenin reduced the effect of TGF-ß3 on phagocytosis to near baseline levels. However, ß-catenin signaling through LiCl treatment did not enhance phagocytic capacity, suggesting a model in which both reorganization of cell junctions and ß-catenin signaling contribute to phagocytosis downstream of TGF-ß3. Our data provide insight into how mammary epithelial cells contribute to apoptotic cell clearance, and in light of the negative consequences of impaired apoptotic cell clearance during involution, may shed light on involution-associated breast pathologies.

Cell type-specific expression of transforming growth factor-beta 1 in the mouse uterus during the periimplantation period.

Immunohistochemistry and in situ and Northern blot hybridization were employed to determine temporal and spatial expression of transforming growth factor-beta 1 (TGF beta 1) in the mouse uterus during the periimplantation period. The polyclonal antisera anti-LC-(1-30) and anti-CC-(1-30), raised against two different preparations of a peptide corresponding to the amino-terminal 30 amino acids of TGF beta 1, were used for histochemical analyses because of their distinct staining patterns. Anti-LC shows intracellular staining, while staining by anti-CC is primarily extracellular. The colocalization of intracellular staining by anti-LC with in situ hybridization of TGF beta 1 mRNA in the luminal and glandular epithelia on days 1-4 of pregnancy (day 1 = vaginal plug) indicates that the epithelial cells are the primary sites of TGF beta 1 synthesis during the preimplantation period. On the other hand, staining of the extracellular matrix of the stroma by anti-CC during this period suggests an active accumulation of TGF-beta 1 that is synthesized in and secreted from the epithelia. While intracellular staining and accumulation of TGF-beta 1 mRNA in the epithelia were clearly evident on days 1-4, the extracellular staining showed temporal fluctuations. The clear extracellular staining of the stroma that was observed on day 1 was absent on day 2; moderate staining was again visualized in the stroma on day 3 and was markedly increased on day 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Presence of transforming growth factor-beta and their selective cellular localization in human ovarian tissue of various reproductive stages.

Immunohistochemical studies were performed using specific polyclonal antibodies to transforming growth factor (TGF)-beta 1 and TGF-beta 2 to determine their presence and cellular localization in human ovarian tissues of various reproductive states. In the small ovarian follicles, the immunostaining for TGF-beta 1 was present in oocytes, follicle cells, and granulosa and theca cell layers. The level of immunostaining associated with granulosa and theca cell layers intensified as the size of the follicles increased. In the luteal tissue, both the small and large luteal cells immunostained for TGF-beta 1 and their intensities were similar to theca and granulosa cell layers, respectively. The patterns of immunostaining were similar in early (days 14-19), mid (days 22-25), and late (days 26-29) luteal phases; however, the intensity was highest at mid and decreased at late luteal phase. Corpus albicans showed a very weak immunostaining for TGF-beta 1, whereas ectopic pregnancy small luteal cells immunostained relatively intensely. The ovarian stromal, luteal tissue fibroblasts, and arterioles endothelial and smooth muscle cells were also immunostained for TGF-beta 1. The immunostaining of the ovarian tissues for TGF-beta 2 indicated that the theca cell layers were the exclusive cells in the follicles with intense immunostaining, which increased in the larger follicles. A low immunostaining was also observed in granulosa cell of the large follicles. In the luteal tissues, only small luteal cells showed intense immunostaining for TGF-beta 2, which was similar in intensity to that in the theca cells; however, the large luteal cells showed a low level of immunostaining at midluteal phase. The small luteal cells in corpus albicans and ectopic pregnancy luteal tissues retained their immunostaining for TGF-beta 2, but with lower intensity. Endothelial and smooth muscle cells of arterioles also immunostained for TGF-beta 2, but not ovarian stromal cells. Atretic follicles showed very low or no detectable immunostaining for TGF-beta 1 or TGF-beta 2. The results of present studies show that human ovarian tissue at all the reproductive states locally produces TGF-beta 1 and TGF-beta 2, and although TGF-beta 1 is present in most major ovarian cell types, TGF-beta 2 is only produced by theca cells in the follicles and small luteal cells in luteal tissues.

Human uterine tissue throughout the menstrual cycle expresses transforming growth factor-beta 1 (TGF beta 1), TGF beta 2, TGF beta 3, and TGF beta type II receptor messenger ribonucleic acid and protein and contains [125I]TGF beta 1-binding sites.

The use of isoform-specific transforming growth factor-beta (TGF beta) primers, 35S-labeled 40-mer oligonucleotide probes and polyclonal antibodies, reverse transcription-polymerase chain reaction, in situ hybridization, and immunohistochemical observations has revealed that human uterine tissue at various reproductive stages expresses TGF beta s and TGF beta type II receptor messenger RNAs (mRNAs) and proteins. The reverse transcription-polymerase chain reaction revealed the predicted 443-, 310-, 524-, and 431-basepair fragments for TGF beta 1, TGF beta 2, TGF beta 3, and TGF beta type II receptor, respectively, in both endometrial and myometrial tissues, which were further verified by restriction enzyme analysis. In situ hybridization and immunohistochemical observations indicated that all uterine cell types express TGF beta s mRNAs and proteins. In the functionalis region, endometrial luminal and glandular epithelial cells are the primary cell types expressing TGF beta s mRNAs and proteins, with lesser expression in stromal cells, whereas in the basalis region, they are equally expressed in both cell types. In myometrium, TGF beta mRNA and protein expression in smooth muscle cells occurs at a substantially lower level than in endometrial tissue. In endometrial tissue, the highest level of TGF beta mRNA and protein expression appeared in the late proliferative and early to midsecretory phases of the menstrual cycle, with a considerable reduction during the late secretory and postmenopausal periods. The pattern and cellular distribution of TGF beta type II receptor protein were similar to those seen with TGF beta isoforms in both endometrial and myometrial tissues. Quantitative autoradiography (net grain density per 100 microns 2) of specific binding of [125I]TGF beta 1 for different uterine cell types indicated that the stromal cells contain a higher grain density than other uterine cell types (P < 0.05), without a significantly different density in the proliferative, compared with the secretory, phase of the menstrual cycle. These data suggest that TGF beta s acting through their specific receptors may play an important role in a variety of uterine functions in an autocrine/paracrine manner, and ovarian steroids may also regulate their expression in endometrial tissue.