Estrogen receptor α36 mediates a bone-sparing effect of 17ß-estrodiol in postmenopausal women.

Recently, a membrane-based estrogen receptor (ER), ER-α36, was identified and cloned that transduces membrane-initiated estrogen signaling such as activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway. Here we show that the postmenopausal level of estradiol (E2) induces mitogenic, antiapoptotic, and antiosteogenic effects and proapoptotic effects in postmenopausal osteoblasts and osteoclasts with high levels of ER-α36 expression, respectively. We also found that ER-α36 mediated the effects of postmenopausal-level E(2) on proliferation, apoptosis, and differentiation of osteoblasts through transient activation of the MAPK/ERK pathway, whereas ER-α36-mediated postmenopausal-level E(2) induces apoptosis of osteoclasts through prolonged activation of the MAPK/ERK pathway with the involvement of reactive oxygen species. We also show that the levels of ER-α36 expression in bone are positively associated with bone mineral density but negatively associated with bone biochemical markers in postmenopausal women. Thus the higher levels of ER-α36 expression are required for preserving bone mass in postmenopausal and menopausal women who become osteoporotic if ER-α36-mediated activities are dysregulated.

Cellular and molecular responses in progressive pseudorheumatoid dysplasia articular cartilage associated with compound heterozygous WISP3 gene mutation.

Progressive pseudorheumatoid dysplasia (PPD) is characterized by continuous degeneration and loss of articular cartilage, which has been attributed to mutations in the gene encoding WISP3. We collected a PPD family and analyzed their WISP3 genes mutation. Articular chondrocytes (ACs) were purified from the femurs of a PPD patient after hip replacement surgery. Cell growth, proliferation, and viability were examined. Gene expression profiling and analyses of matrix metalloproteinases (MMP)-1, -3, and -13 proteins were carried out using cDNA differential microarrays, real-time reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot analysis. We found that two probands carried a deletion (840delT) mutation in maternal allele, which leads to truncated WISP3 protein missing 43 residues in C terminus; and a 1000T>C substitution in paternal allele, which was also passed on to four other members in the PPD kindred. PPD ACs were heterogeneous in size with an enhanced rate of cell proliferation and viability compared with the normal ACs. MMP-1, -3, and -13 mRNA expressions were dereased in PPD ACs. MMP-1, -3, and -13 protein levels, however, were increased in cell lysates from PPD ACs, but markedly decreased in the supernatants from cultured ACs. WISP3 mRNA expression in PPD ACs was also decreased. Our results show, for the first time, a compound heterozygous mutation of WISP3 and a series of cellular and molecular changes disturbing the endochondral ossification in this PPD patient.

[Expression of VEGF-C and angiogenesis, and lymphangiogenesis in papillary thyroid carcinoma].

OBJECTIVE: To investigate the relationship between the expression of vascular endothelial growth factor C (VEGF-C) and angiogenesis and lymphangiogenesis in papillary thyroid carcinoma (PTC). METHODS: Seventy-two PTC cases were divided into 3 groups according to the level of invasion: papillary microcarcinoma group (PMC group), intrathyroid carcinoma group (IPC group), and extrathyroid carcinoma group (EPC group). They were again divided into 2 groups according to lymph node metastasis: lymph node metastasis group and lymph node no-metastasis group. The expressions of VEGF-C, CD105 and vascular endothelial growth factor receptor-3 (VEGFR-3) were detected by SP method of immunohistochemical staining. The expression of VEGF-C was analyzed quantitatively by image analysis system, and the PI of VEGF-C (VEGF-C-PI), the number of MVD (microvessel density), and LVD (lymphaticvessel density) were obtained. RESULTS: The VEGF-C-PI of lymph node metastasis group (23.15 +/- 3.75) was higher than that of lymph node non-metastasis group (14.54 +/- 2.93) (P <0.01). MVD was 35.25 +/- 2.06 in the PMC group, 41.75 +/- 5.46 in the IPC group, and 52.58 +/- 4.16 in the EPC group, which showed the elevatory tendency with the increase of invasion (P < 00.5). LVD was 6.00 +/- 0.81 in the PMC group, 13.80 +/- 1.81 in the IPC group, and 19.17 +/- 2.96 in the EPC group, which again showed the elevatory tendency with the increase of invasion (P <0.05). The LVD of lymph node metastasis group (19.56 +/- 2.45) was significantly higher than that of lymph node non-metastasis group (12.48 +/- 2.84) (P < 0.05). VEGF-C was positively correlated with MVD and LVD (r = 0.743, 0.90, P <0.01). CONCLUSION: The expressions of VEGF-C and LVD are related to lymph node metastasis of PTC. MVD and LVD are related to the invasion of PTC. VEGF-C may play an important role in the angiogenesis and lymphangiogenesis.

Effects of 17 beta-estradiol on the expression of interstitial collagenases-8 and -13 (MMP-8 and MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in ovariectomized rat osteoblastic cells.

Estrogen plays an important role in maintaining normal bone metabolism via the direct or indirect regulation of bone cells. Osteoblastic cells, as the target cells of estrogen, can secrete multiple matrix metalloproteinases (MMPs) that participate in bone remodeling. It has been demonstrated that bone loss induced by estrogen deficiency is closely related to the abnormal expression of multiple MMPs in osteoblastic cells. However, the regulating action of estrogen on the expression of interstitial collagenases MMP-8 and MMP-13 in osteoblastic cells in vivo remains unclear. We used an ovariectomized osteoporotic rat model to analyze the changes in the histomorphometric parameters of bone after and without treatment with 17beta-estradiol (E(2)); We also used immunohistochemistry and in situ hybridization to observe changes in the expression of mRNA and the proteins MMP-8, MMP-13 and TIMP-1 in osteoblastic cells in rat proximal tibia. In this study, we found that in the ovariectomized rat the expression of MMP-13 mRNA and protein increased markedly, whereas the expression of MMP-8 and TIMP-1 mRNA and protein did not change significantly. Our analysis showed that the expression of MMP-13 protein was correlated positively to bone trabecular separation, osteoid surface area, and negatively to trabecular numbers and the percentage of trabecula bone volume/total tissue volume. Our results suggest that MMP-13 plays an important role in estrogen deficiency-induced bone loss, while estrogen can inhibit bone resorption and reduce bone turnover rate by down-regulating the expression of MMP-13 in osteoblastic cells.

[Pathology and molecular pathogenesis of spondyloepiphyseal dysplasia tarda with progressive arthropathy caused by compound CCN6 heterogeneous gene mutations].

OBJECTIVE: To characterize the clinical manifestations, features of roentgenography and MR imaging, and the pathology of articular cartilage and matrix of spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA), to screen the mutations of the disease-causing CCN6 gene, and try to elucidate the molecular pathogenesis of SEDT-PA. METHODS: A questionnaire survey on the clinical manifestations and history was conducted among a pedigree of SEDT-PA with 57 persons (53 living members) in tolal, including 2 probands, a 19-year old female and a 9-year old male. Physical examination and roentgenography and MR imaging were used on the 2 probands to characterize the features of their joints and articular cartilage. The femoral head extracted during replacement of hip of the proband 1 underwent hematoxylin-eosin staining and toludine blue (TB) staining to observe the pathological changes and ultra-microstructure of the articular chondrocytes and cartilage matrix using electron microscopy. Peripheral blood samples were collected from these 53 living members and 100 healthy controls. PCR was used to examine and sequence the exons of CCN6. 3D-conformational illustration of mutant CCN6 proteins were predicted using the Prospect Software. RESULTS: The clinical manifestations, radiology, and MR imaging established the diagnosis of SEDT-PA. Pathologic examination demonstrated that the articular cartilage chondrocytes became hyper-proliferative and immature, while the density and diameter of matrix collagens were dramatically decreased. Mutation studies showed the two probands carried a deletion (840delT) mutation in maternal allele, that caused the truncated CCN6 protein to miss 43 residues in C-terminus; and a substitution mutation (1000T-->C, Ser334Pro) in paternal allele, which was also inherited down to other 4 members in the SEDT-PA kindred. The predicted 3D-conformational changes of the truncated mutant and the Ser334Pro mutant CCN6 proteins demonstrated that in comparison with the wild CCN6 protein, the single long peptide loop in the region from signal peptide to the beginning 24 amino acid residues in the first domain (IGFBP) was subjected to folding into two smaller cross-loops accompanied with a much shorter C-terminus in 840 delT truncated mutant CCN6 protein, and no substantial 3D-conformational change of Ser334Pro mutant CCN6 protein was detected except for the C-terminal peptide towards the opposite direction. CONCLUSION: Novel 840delT mutation of CCN6 gene is the leading cause of SEDT-PA though coexistence of T1000C substitution is necessary for the clinical onset of SEDT-PA, in which marked abnormalities of cartilage chondrocytes and matrix are morphologically and functionally presented.

[Expression of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases in the hepatocellular carcinomas].

OBJECTIVE: To explore the expression and clinical prognostic significance of matrix metalloproteinase-2 mRNA (MMP-2 mRNA), tissue inhibitor of matrix metalloproteinase-2 mRNA (TIMP-2 mRNA), matrix metalloproteinase-2 protein (MMP-2), matrix metalloproteinase-9 protein (MMP-9), tissue inhibitor of matrix metalloproteinase-1 protein (TIMP-1), and tissue inhibitor of matrix metalloproteinase-2 protein (TIMP-2) in the hepatocellular carcinomas (HCCs). METHODS: Fifty-six specimens of HCCs from 56 patients, who were followed-up, were investigated by in situ hybridization with specific probes for MMP-2, TIMP-2, and by immunohistochemistry with anti-MMP-2, MMP-9 and anti-TIMP-1, TIMP-2 monoclonal antibody. We analyzed the data with chi-square test, spearmans correlation analysis, monovariate Kaplan-Meier plot and multivariate Cox regression analysis. RESULTS: 1. The positive expression of MMP-2mRNA, TIMP-2mRNA, MMP-2 protein, MMP-9 protein, TIMP-1 protein and TIMP-2 protein in the 56 HCCs cases were 48 (85.7%), 35 (62.5%), 44 (78.6%), 41 (73.2%), 30 (53.6%), and 38 (68%), respectively. 2. We found over-expression of MMP-2 mRNA, MMP-2 protein, and MMP-9 protein, but low expression of TIMP-1 protein in the 56 cases of HCCs (P < 0.01, P < 0.05). 3. There was a positive association between TIMP-2mRNA and TIMP-2 protein expression, and between MMP-2 mRNA and MMP-2 protein in HCCs, respectively (r = 0.316, P < 0.05; r = 0.356, P < 0.05). 4. Over-expression of MMP-2 mRNA was positively correlated to the tumor size and TNM classification (r = 0.441, P < 0.001; r = 0.340, P < 0.05), and MMP-9 protein was related to shortened survival (P < 0.05). 5. In both monovariate Kaplan-Meir plot and multivariate Cox regression analysis, the expression of MMP-2 protein and MMP-9 protein were linked to unfavorable prognosis. These results were further confirmed by multivariate analysis in which MMP-2 protein and MMP-9 protein emerged as independent prognostic factors for poor survival regardless of the age, tumor size, tumor grades, TNM classification and expression of MMP-2mRNA, TIMP-2mRNA, TIMP-1 protein and TIMP-2 protein. The hazard ratios of expression of MMP-2 protein and MMP-9 protein were 3.875 and 4.528, respectively. CONCLUSION: The over-expression of MMP-2mRNA, MMP-2 protein and MMP-9 protein and the imbalance between MMP-2 and TIMP-2 play pivotal roles in the degradation of excellular matrix of HCCs. MMP-2 and MMP-9 immunoreactive protein have been closely related to a shortened survival independent of major prognostic indicators in the primary HCC and increase the risk of the patients after the operation.

[Expression and clinical significance of MMP-2, MMP-9,TIMP-1, and TIMP-2 in breast carcinoma].

BACKGROUND & OBJECTIVE: Expression imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play pivotal roles in tumor invasion and metastasis. But little is known about the correlation between their expression and breast cancer prognosis. The aim of this study was to investigate the expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 in breast carcinomas and to seek their relationship with breast cancer invasion, metastasis, and prognosis. METHODS: Sixty-six patients of breast cancer with clinical features and survival data were enrolled. The mRNA expression of TIMP-2, MMP-2 were determined using in situ hybridization. The protein expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined using immunohistochemistry. The results were analyzed using chi-square test, Kaplan-Meier method, and Cox multivariate regression analysis. RESULTS: The positive expression rates of TIMP-2 mRNA, MMP-2 mRNA and MMP-2, MMP-9, TIMP-1, and TIMP-2 protein were 66.7% (44/66), 65.2% (43/66) and 71.2% (47/66), 68.2% (45/66), 40.9% (27/66), 69.7% (46/66), respectively. The expression of MMP-2 protein had positive correlation with those of MMP-2 mRNA and MMP-9 protein(P< 0.01). The expression of TIMP-2 mRNA had positive correlation with that of TIMP-2 protein. Negative correlation between expression of TIMP-1 protein and MMP-9 protein was found (P< 0.01). Overexpression of MMP-2 and MMP-9 protein were higher in breast cancers with lymph node metastases than those without lymph node metastases, whereas TIMP-2 mRNA and TIMP-1 protein expression were lower in breast cancers with lymph node metastases than those without lymph node metastases (P< 0.05). MMP-2 mRNA and MMP-9 protein were positively associated with the tumor size and shortened survival time(P< 0.05, P< 0.01). Increased expression of MMP-9 protein was correlated with high TNM classification(P< 0.01). The patients of menopause and ER negative expression had higher expression of MMP-2 mRNA (P< 0.05). Kaplan-Meier analysis showed that MMP-2 mRNA, MMP-2 and MMP-9 proteins were linked with unfavorable prognosis(P< 0.01,P< 0.05). CONCLUSION: Overexpression of MMP-2, MMP-9 and expression imbalance between MMP-9 and TIMP-1 protein might play critical roles in degradation of extracellular matrix to enhance the invasive and metastatic capacity of breast cancer. MMP-2 protein might be applied as an independent prognostic indicator for primary breast cancer.

The effect of low dose nylestriol-levonorgestrel replacement therapy on bone mineral density in women with postmenopausal osteoporosis.

OBJECTIVE: Recently our studies have shown that nylestriol in combination with levonorgestrel prevented bone loss, decreased bone turnover rate and increased the maximal loading of bone without obvious side effects in retinoic acid (RA) induced osteoporotic rats. In addition to the animal experiments, we evaluate the effect of Compound Nylestriol Tablet (CNT) on bone mineral density (BMD) in women with postmenopausal osteoporosis. Compound Nylestriol Tablet, which contains 0.5 mg of nylestriol (cyclopentylethinyl estriol) and 0.15 mg of levonorgestrel per tablet, was authorized as a new anti-osteoporotic agent for clinical trial in postmenopausal osteoporosis. METHODS: One year's clinical observation was performed in 191 eligible patients who were randomly divided into two groups (A and B). In group A, 119 patients were treated for one year with CNT (one tablet per week) and in group B, 72 patients with placebo. Bone mineral density of lumbar antero-posterior spine (L1-L4), lateral spine, total hip and total forearm positions including radius+ulna at the ultra distal areas, mid areas, and one-third areas, were measured before and after treatment. Biochemical parameters and effects of CNT on uterus, and breast were observed. RESULTS: We found that patients treated with CNT had a significant decrease of bone loss in total forearm, including radius+ulna at the ultra distal, mid, and 1/3 areas compared with control subjects (all P < 0.05). An improved BMD tendency could be seen at the lumbar spine. There were no differences in the observed biochemical variables. No side-effects on uterus, or mammary glands observed. None of the patients had uterine bleeding or vertebral fractures during one year's CNT treatment. CONCLUSION: These data suggested that CNT is effective, safe and convenient in treating postmenopausal osteoporosis.

[In situ expression of connexins in various carcinomas].

BACKGROUND & OBJECTIVE: Malignant cells are often associated with aberrant expression or localization of connexins. Expression of Cx26, Cx32, Cx43, and Cx45 genes were studied to gain their expression profile in tissue microarrayers consisting of various carcinomas and to elucidate their function in carcinogenesis. METHODS: Basing on the principle of constructing tissue microarrays, the authors take use of self-made tissue arrayer to construct tissue microarrays for the different kinds of cancer specimens. Meanwhile, expression of connexin(Cx) genes, such as Cx32, Cx26, Cx43, and Cx45 in the tissue microarrays were detected in 292 cases of tumor tissues and 89 paratumor tissues by immunohistochemistry. RESULTS: (1) Three kinds of tissue microarrays consisting samples from 20 different carcinomas were constructed successfully, which contained 360, 200, or 100 spots in each receptive paraffin block with tissue cylinder of 0.75mm or 0.6mm diameter respectively.(2) The expression profiles of Cx32, Cx26, Cx43, and Cx45 in 20 kinds of carcinomas and their related adjacent-cancer tissues were gained, which were widely low expressed in carcinomas especially in nasopharyngeal carcinomas. Expression of Cx26, Cx32, Cx43, and Cx45 in carcinomas such as carcinomas of colon and recta, hepatocellular carcinomas, gastric carcinomas, lung carcinomas and thyroid cancers were significantly lower than their related adjacent-cancer tissues. CONCLUSION: Low expression of Cx26, Cx32, Cx43, and Cx45 might play crucial roles in carcinogenesis of many kinds of carcinomas. Tissue microarrays consisting of many different kinds of carcinomas provide a new high-throughout tool for rapid and comprehensive molecular expression profiles of carcinomas, such as connexin genes.

[Technique for undecalcified bone tissue. Immunohistochemistry and in situ hybridization].

OBJECTIVE: To investigate the feasibility of applying immunohistochemistry (IH) and in situ hybridization (ISH) technique to the undecalcified bone sections. METHODS: The proximal tibiae of SD rats were embedded with the modified methylmethacrylate low-temperature embedding method and then made into undecalcified bone sections. The sections were stained with Goldner's Masson Trichrome, and the expression of IGF-1 mRNA and protein in the bone tissue cells were detected by IH and ISH. RESULTS: Goldner's staining demonstrated the structure of trabeculae bone was intact and osteoid at the edge of trabeculae stained red. Osteoblasts and osteoclasts in bone sections could be seen clearly. The positive signals of IGF-1 mRNA and protein were found in the cytoplasm of osteoblasts, chondrocytes in epiphyseal plate and some mononuclear cells in the bone marrow. The matrix of trabeculae also showed positive expression of IGF-1 protein. CONCLUSION: The undecalcified bone sections prepared by the method can meet the needs of IH and ISH. The establishment of this method will provide technological platform for the study of molecular pathology on metabolic bone diseases such as osteoporosis.