Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Weightlessness induces bone loss in humans and animal models. We employed the NASA-approved Rotating Wall Vessel bioreactor (RWV) to develop osteoblast-like cell cultures under microgravity and evaluate osteoblast phenotype and cell function. Rat osteoblast-like cell line (ROS.SMER#14) was grown in the RWV at a calculated gravity of 0.008g. For comparison, aliquots of cells were grown in conventional tissue culture dishes or in Non-Rotating Wall Vessels (N-RWV) maintained at unit gravity. In RWV, osteoblasts showed high levels of alkaline phosphatase expression and activity, and elevated expression of osteopontin, osteocalcin, and bone morphogenetic protein 4 (BMP-4). In contrast, the expression of osteonectin, bone sialoprotein II and BMP-2 were unaltered compared to cells in conventional culture conditions. These observations are consistent with a marked osteoblast phenotype. However, we observed that in RWV osteoblasts showed reduced proliferation. Furthermore, DNA nucleosome-size fragmentation was revealed both morphologically, by in situ staining with the Thymine-Adenine binding dye bis-benzimide, and electrophoretically, by DNA laddering. Surprisingly, no p53, nor bcl-2/bax, nor caspase 8 pathways were activated by microgravity, therefore the intracellular cascade leading to programmed cell death remains to be elucidated. Finally, consistent with an osteoclast-stimulating effect by microgravity, osteoblasts cultured in RWV showed upregulation of interleukin-6 (IL-6) mRNA, and IL-6 proved to be active at stimulating osteoclast formation and resorbing activity in vitro. We conclude that under microgravity, reduced osteoblast life span and enhanced IL-6 expression may result in inefficient osteoblast- and increased osteoclast-activity, respectively, thus potentially contributing to bone loss in individuals subjected to weightlessness.
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PMID:Characterization of the osteoblast-like cell phenotype under microgravity conditions in the NASA-approved Rotating Wall Vessel bioreactor (RWV). 1189 60

Maturation of epiphyseal growth plate chondrocytes plays an important role in endochondral bone formation. Previously, we demonstrated that retinoic acid (RA) treatment stimulated annexin-mediated Ca(2+) influx into growth plate chondrocytes leading to a significant increase in cytosolic Ca(2+), whereas K-201, a specific annexin Ca(2+) channel blocker, inhibited this increase markedly. The present study addressed the hypothesis that annexin-mediated Ca(2+) influx into growth plate chondrocytes is a major regulator of terminal differentiation, mineralization, and apoptosis of these cells. We found that K-201 significantly reduced up-regulation of expression of terminal differentiation marker genes, such as cbfa1, alkaline phosphatase (APase), osteocalcin, and type I collagen in RA-treated cultures. Furthermore, K-201 inhibited up-regulation of annexin II, V, and VI gene expression in these cells. RA-treated chondrocytes released mineralization-competent matrix vesicles, which contained significantly higher amounts of annexins II, V, and VI as well as APase activity than vesicles isolated from untreated or RA/K-201-treated cultures. Consistently, only RA-treated cultures showed significant mineralization. RA treatment stimulated the whole sequence of terminal differentiation events, including apoptosis as the final event. After a 6-day treatment gene expression of bcl-2, an anti-apoptotic protein, was down-regulated, whereas caspase-3 activity and the percentage of TUNEL-positive cells were significantly increased in RA-treated cultures compared with untreated cultures. Interestingly, the cytosolic calcium chelator BAPTA-AM and K-201 protected RA-treated chondrocytes from undergoing apoptotic changes, as indicated by higher bcl-2 gene expression, reduced caspase-3 activity, and the percentage of TUNEL-positive cells. In conclusion, annexin-mediated Ca(2+) influx into growth plate chondrocytes is a positive regulator of terminal differentiation, mineralization, and apoptosis events in growth plate chondrocytes.
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PMID:Annexin-mediated Ca2+ influx regulates growth plate chondrocyte maturation and apoptosis. 1244 91

There has been considerable variability in the reported results of immunohistochemical staining for some diagnostically relevant antigens. Our objectives in this study were to (1) use a multitumor tissue microarray with tissue from 351 cases received in our department, representing 16 normal tissues and 47 different tumor types, to compare immunohistochemical staining results in our laboratory with published data, using a panel of 22 antibodies; (2) assess interlaboratory variability of immunohistochemical staining for S-100 using this microarray; and (3) test the ability of hierarchical clustering analysis to group tumors by primary site, based on their immunostaining profile. Tissue microarrays consisting of duplicate 0.6-mm cores from blocks identified in the hospital archives were constructed and stained according to our usual protocols. Antibodies directed against the following antigens were used: B72.3, bcl-2, carcinoembryonic antigen, c-kit, pankeratin, CD 68, CD 99, CK 5/6, CK 7, CK 8/18, CK19, CK 20, CK 22, epithelial membrane antigen, estrogen receptor, melan-A, p53, placental alkaline phosphatase, S-100, synaptophysin, thyroid transcription factor-1, and vimentin. Staining results on the array cases were compared with published results, and hierarchical clustering analysis was performed based on the immunohistochemical staining results. Unstained slides of the multitumor tissue microarray were sent to five other diagnostic immunohistochemistry laboratories and stained for S-100 protein. The staining results from the different laboratories were compared. Staining results using our current methods and samples from our laboratory were compatible with those described in the literature for most antigens. Placental alkaline phosphatase staining was not specific with our protocol, showing staining of a broad spectrum of different tumors; this finding initiated a review of our recent requests for placental alkaline phosphatase immunostaining and revealed two instances in which placental alkaline phosphatase positivity was incorrectly interpreted as evidence of a germ cell tumor. S-100 staining was less sensitive but more specific for the diagnosis of melanoma or neural tumor in our laboratory, compared to some published reports. Assessment of interlaboratory variability of S-100 immunostaining showed that there was more frequent staining of carcinomas in some laboratories, resulting in decreased specificity of S-100 staining in distinguishing melanoma from carcinoma. Hierarchical clustering analysis showed a strong trend for tumors to cluster by tissue of origin, but there were significant exceptions. We conclude that multiple-tumor microarrays are an efficient method for assessing the sensitivity and specificity of staining with any antibody used diagnostically. As a tool for quality assurance, they offer the advantage of taking into account local differences in tissue fixation, processing, and staining. They also allow cost-effective assessment of interlaboratory variability in immunohistochemical staining. Results of hierarchical clustering analysis show the potential for panels of immunohistochemical stains to identify the primary site of metastatic carcinomas but also confirm the limitations of currently available antibodies in giving unequivocal tissue-specific staining patterns.
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PMID:Tissue microarrays are an effective quality assurance tool for diagnostic immunohistochemistry. 1248 Oct 20

Perivascular epithelioid cells (PEC) in angiomyolipoma (AML) were recently proposed to be its most common progenitor cells. Histologically, triphasic components were present in various proportions, but were overwhelmingly myogenic in epithelioid variants of AML. Despite histological discrimination, the immunophenotypic profiles between triphasic and epithelioid AML have never been compared. The aim of the present study was to clarify the identity of PEC by using immunoreactivity to estrogen receptor (ER), progesterone receptor (PR), bcl-2 and placenta alkaline phosphatase (PLAP), and to use this information to compare triphasic and epithelioid AML. A total of 33 out of 67 cases of renal angiomyolipoma that underwent surgery were reviewed over the period 1998-2003. Two cases were associated with tuberous sclerosis. Ten patients had other malignant tumors, and three patients had a nodal extension. Immunohistochemistry showed that bcl-2 (59.4%), PLAP (46.9%), HMB-45 (100%) was predominantly localized around vessels. The stem cell markers were absolutely negative in all AML types. The estrogen receptors were positive in 14 cases (42.4%) and the progesterone receptors were positive in five cases. Bcl-2 and both female sex hormone receptors were significantly more frequent in the epithelioid variant of AML than in the triphasic type. Perivascular epithelioid cells express bcl-2, ER, PR and PLAP, and ER could be partly associated with myogenic proliferation.
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PMID:Estrogen receptor is significantly associated with the epithelioid variants of renal angiomyolipoma: a clinicopathological and immunohistochemical study of 67 cases. 1518 5

Although neuroepithelial tubules (NET) often are a component of immature teratoma (IT), they are not always required for diagnosis. Other somatic elements are sufficient and often verified with immunohistochemical stain. This study was designed to determine the definition of immaturity versus fetal ontogeny, using several molecular markers in IT. It is our contention that IT is equivalent to an embryonic stage less than a fertilization age (FA) of 8 weeks, and a mature teratoma (MT) to a fetal stage later than a FA of 8 weeks, whereas an embryonal carcinoma (Eca) matches a pre-embryonic stage earlier than a FA of 2 weeks. The teratomatous components used as a roadmap to evaluate maturity included: a lobular structure of primitive endodermal tubules (FA 4 to 6 weeks), a ventricle-lined cortical plate (FA 9 weeks), a complex papillary choroid plexus (FA 10 weeks), melanin deposition in hair follicles (FA 15 weeks), and the bell stage of odontogenesis (FA 19 weeks). The teratomatous components of 25 resected ovarian solid teratoma samples were compared with fetal ontogeny. For an immunohistochemical analysis, the CD30, CD34, CD99, bcl-2, alpha-fetoprotein (AFP), and placenta-like alkaline phosphatase (PLAP) were assessed. The AFP and Ki-1 were positive in the embryoid body, which was identified at a FA less than 4 weeks in Eca. The AFP was positive in the primitive endodermal components and some of the squamous epithelium in IT. The CD99 and bcl-2 were selectively stained in the primitive NET, which was detected no later than a FA of 6 weeks. The CD34 and bcl-2 were positive in the immature-looking precartilage blastomatous components, which proved useful for detecting immature cartilage, corresponding to a FA of 5 to 6 weeks. The ontogeny of IT was found to correspond to the embryonic stage at a FA of 2 to 8 weeks, and CD99, CD34, bcl-2, AFP, CD30, and PLAP could be used as supportive tools to define IT. This new grading system could be more scientific and more reproducible in any spectra of teratoma.
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PMID:Diagnostic challenge of fetal ontogeny and its application on the ovarian teratomas. 1578 74

Puerarin is a major isoflavonoid compound isolated from Pueraria lobata, an edible vine used widely for various medicinal purposes. It has been used for centuries in China to counteract alcohol intoxication. However, the effects of puerarin on chemical-induced liver fibrosis have not been reported. In the present study, we investigated the effects of puerarin on liver fibrosis in Wistar rats induced by alcohol plus carbon tetrachloride administration. Liver fibrosis was produced in rats by treatment with a mixture (50% alcohol, 8 g/kg per day; corn oil, 2 g/kg per day; pyrazole, 24 mg/kg per day; ig) once a day and by intraperitoneal injection of 0.25 ml/kg of a 25% solution of carbon tetrachloride in olive oil twice a week for 8 weeks. After 8 weeks, treatment with puerarin (0.4 and 0.8 g/kg ig, daily for 4 weeks) was conducted to examine its therapeutic effects. At the same time, the model group and treatment group continued to receive the chemical mixture, while the control group received saline instead of the chemical mixture. Upon pathological examination, the puerarin-treated rats significantly reversed the symptoms of liver fibrosis and other hepatic lesions. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as indexes of hepatic cell disruption, were reduced with puerarin treatment, whereas no significant effect was discovered in the levels of alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT) activities. A significant increase in apoptosis of activated hepatic stellate cell (HSC) was found by flow cytometric analysis of the hepatic tissues. And the expression of bcl-2 mRNA was down-regulated after puerarin administration. Consequently, all these results showed that puerarin could effectively reverse chemical-induced liver fibrosis in experimental rats, via the recovery of hepatic injury as well as the induction of apoptosis in activated HSC.
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PMID:Reversal of chemical-induced liver fibrosis in Wistar rats by puerarin. 1642 32

Twenty-five children (19 M:6 F) with newly diagnosed ALL with median age of 5.5 years (1 month-12 years) were enrolled in the study. Apoptosis regulator proteins bcl-2 and bax were measured in all patients using alkaline phosphatase anti-alkaline phosphatase method. Twenty-one patients were positive for bcl-2 and 23 cases for Bax, although expression levels varied. Patients who presented with splenomegaly or hepatomegaly < 5 cm expressed significantly higher levels of bcl-2 and bax protein expression. Neither of age ( < or >10 years), sex, generalized lymphadenopathy, WBC ( < or >50,000/mul) or FAB subtype was associated with high levels of bcl-2 or bax protein expression. Patients with higher mean hemoglobin levels (p = 0.009), high blast % in bone marrow (p = 0.02), immature immunophenotype (p = 0.001) exhibited signifxicantly higher bcl-2 levels. Bcl-2/bax ratio correlated inversely with TLC at presentation (p = 0.022; r = - 0.456) and in B-lineage leukemic cells as compared to T-lineage cells (p = 0.002). Bcl-2/bax ratio did not correlate with any other variable measured. Bcl-2 and bax protein co-express in ALL and high bcl-2/bax ratio correlates with good prognosis features.
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PMID:Expression of apoptosis regulators Bcl-2 and Bax in childhood acute lymphoblastic leukemia. 1736 91

Ghrelin is a 28-residue peptide identified in the stomach as an endogenous ligand of the growth hormone secretagogue receptor that is expressed in a variety of peripheral tissues, as well as in the brain. In previous studies, ghrelin has been shown to stimulate both adipogenic differentiation from preadipocytes and osteogenic differentiation from preosteoblasts or primary osteoblasts. This study was undertaken to investigate the direct effect of ghrelin on the lineage allocation of mesenchymal stem cells (MSCs). We identified ghrelin receptor mRNA in C3H10T1/2 cells, and we found the levels of this mRNA to be attenuated during osteogenic differentiation. Treatment of cells with ghrelin resulted in both proliferation and inhibition of caspase-3 activity. In addition, ghrelin decreased serum deprivation-induced bax protein expression and release of cytochrome c from the mitochondria, whereas it increased bcl-2 protein expression. Moreover, ghrelin inhibited early osteogenic differentiation, as shown by alkaline phosphatase activity and staining, and inhibited osteoblast-specific genes expression by altering Runx2, PPARgamma, and C/EBPalpha protein expression.
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PMID:Ghrelin inhibits early osteogenic differentiation of C3H10T1/2 cells by suppressing Runx2 expression and enhancing PPARgamma and C/EBPalpha expression. 1916 Apr 22

The aim of this work was to evaluate the biocompatibility of poly(vinylidene fluoride-trifluoroethylene)/barium titanate (P(VDF-TrFE)/BT) membrane to be used in guided tissue regeneration (GTR). Fibroblasts from human periodontal ligament (hPDLF) and keratinocytes (SCC9) were plated on P(VDF-TrFE)/BT and polytetrafluorethylene membranes at a cell density of 20,000 cells well(-1) and cultured for up to 21 days. Cell morphology, adhesion and proliferation were evaluated in hPDLF and keratinocytes, while total protein content and alkaline phosphatase (ALP) activity were assayed only for hPDLF. Using a higher cell density, real-time polymerase chain reaction (PCR) was performed to assess the expression of typical genes of hPDLF, such as periostin, PDLs17, S100A4 and fibromodulin, and key phenotypic markers of keratinocytes, including involucrin, keratins 1, 10 and 14. Expression of the apoptotic genes bax, bcl-2 and survivin was evaluated for both cultures. hPDLF adhered and spread more on P(VDF-TrFE)/BT, whereas keratinocytes showed a round shape on both membranes. hPDLF adhesion was greater on P(VDF-TrFE)/BT at 2 and 4h, while keratinocyte adhesion was similar for both membranes. Whereas proliferation was significantly higher for hPDLF on P(VDF-TrFE)/BT at days 1 and 7, no signs of keratinocyte proliferation could be noticed for both membranes. Total protein content was greater on P(VDF-TrFE)/BT at 7, 14 and 21 days, and higher levels of ALP activity were observed on P(VDF-TrFE)/BT at 21 days. Real-time PCR revealed higher expression of phenotypic markers of hPDLF and keratinocytes as well as greater expression of apoptotic genes in cultures grown on P(VDF-TrFE)/BT. These results indicate that, by favoring hPDLF adhesion, spreading, proliferation and typical mRNA expression, P(VDF-TrFE)/BT membrane should be considered an advantageous alternative for GTR.
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PMID:In vitro biocompatibility of poly(vinylidene fluoride-trifluoroethylene)/barium titanate composite using cultures of human periodontal ligament fibroblasts and keratinocytes. 1970 97

Liuweidihuang wan (LW), initially a well-known formula for curing "wu chi wu ruan", is commonly used nowadays for clinical treatment of postmenopausal osteoporosis (PO), but the identity of the effective substance(s) remains unclear. The present study was designed to evaluate the effects of morroniside and loganin isolated from LW on the proliferation, differentiation and apoptosis of MC3T3-E1 cells, as well as the possible mechanism of action. Morroniside and loganin had no effects on the proliferation of MC3T3-E1 cells, but both susbtances could improve the activity of alkaline phosphatase (ALP), and increase the contents of collagen type I and osteocalcin. Simultaneously, the mRNA expression of caspase-3, capase-9, RANKL was down-regulated and that of bcl-2 was up-regulated, which partially explains the anti-osteoporosis mechanism in MC3T3-E1 cells. In conclusion, morroniside and loganin may directly promote the differentiation and inhibit the apoptosis of MC3T3-E1 cells, and accordingly indirectly reduce bone resorption, which makes them promising natural drugs leads for treating PO in the near future.
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PMID:The pharmacological effects of morroniside and loganin isolated from Liuweidihuang Wan, on MC3T3-E1 cells. 2096 81


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