scholarly journals Characterization of 11beta-hydroxysteroid dehydrogenase activity and corticosteroid receptor expression in human osteosarcoma cell lines

1999 ◽  
Vol 161 (3) ◽  
pp. 455-464 ◽  
Author(s):  
R Bland ◽  
CA Worker ◽  
BS Noble ◽  
LJ Eyre ◽  
IJ Bujalska ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Cell Lines ◽  
Primary Cultures ◽  
Hydroxysteroid Dehydrogenase ◽  
Receptor Expression ◽  
Osteosarcoma Cell ◽  
Bone Homeostasis ◽  
Rt Pcr

Studies in vitro and in vivo have shown that corticosteroids play an important role in bone physiology and pathophysiology. It is now established that corticosteroid hormone action is regulated, in part, at the pre-receptor level through the expression of isozymes of 11beta-hydroxysteroid dehydrogenase (11beta-HSD), which are responsible for the interconversion of hormonally active cortisol to cortisone. In this report we demonstrate 11beta-HSD activity in human osteoblast (OB) cells. Osteosarcoma-derived OB cell lines TE-85, MG-63 and SaOS-2 and fibrosarcoma Hs913T cells express the type 2 isoform of 11beta-HSD, as determined by reverse transcription polymerase chain reaction (RT-PCR) and specific enzyme assays. Enzyme activity was shown to be strictly NAD dependent with a Km of approximately 71 nM; 11beta-HSD type 1 mRNA expression and enzyme activity were not detected. All four cell lines expressed mRNA for the glucocorticoid receptor (GR) and mineralocorticoid receptor, but specific binding was only detectable with radiolabelled dexamethasone (Kd=10 nM) and not aldosterone. MG-63 cells had two to three times more GR than the other OB cells, which correlated with the higher levels of 11beta-HSD 2 activity in these cells. In contrast to the osteosarcoma cell studies, RT-PCR analysis of primary cultures of human OB cells revealed the presence of mRNA for 11beta-HSD 1 as well as 11beta-HSD 2. However, enzyme activity in these cells remained predominantly oxidative, i.e. inactivation of cortisol to cortisone (147 pmol/h per mg protein at 500 nM cortisol) was greater than cortisone to cortisol (10.3 pmol/h per mg protein at 250 nM cortisone). Data from normal human OB and osteosarcoma cells demonstrate the presence of an endogenous mechanism for inactivation of glucocorticoids in OB cells. We postulate that expression of the type 1 and type 2 isoforms of 11beta-HSD in human bone plays an important role in normal bone homeostasis, and may be implicated in the pathogenesis of steroid-induced osteoporosis.

scholarly journals Importance of the 11β-hydroxysteroid dehydrogenase enzyme in clinical disorders

2013 ◽  
Vol 154 (8) ◽  
pp. 283-293 ◽  
Author(s):  
Karolina Feldman ◽  
István Likó ◽  
Zsolt Nagy ◽  
Ágnes Szappanos ◽  
Vince Kornél Grolmusz ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Chromosome 1 ◽  
Gene Encoding ◽  
Local Synthesis ◽  
Dehydrogenase Enzyme ◽  
Clinical Disorders ◽  
Polymorphic Variants

Glucocorticoids play an important role in the regulation of carbohydrate and amino acid metabolism, they modulate the function of the immune system, and contribute to stress response. Increased and decreased production of glucocorticoids causes specific diseases. In addition to systemic hypo- or hypercortisolism, alteration of local synthesis and metabolism of cortisol may result in tissue-specific hypo- or hypercortisolism. One of the key enzymes participating in the local synthesis and metabolism of cortisol is the 11β-hydroxysteroid dehydrogenase enzyme. Two isoforms, type 1 and type 2 enzymes are located in the endoplasmic reticulum and catalyze the interconversion of hormonally active cortisol and inactive cortisone. The type 1 enzyme mainly works as an activator, and it is responsible for the generation of cortisol from cortisone in liver, adipose tissue, brain and bone. The gene encoding this enzyme is located on chromosome 1. The authors review the physiological and pathophysiological processes related to the function of the type 1 11β-hydroxysteroid dehydrogenase enzyme. They summarize the potential significance of polymorphic variants of the enzyme in clinical diseases as well as knowledge related to inhibitors of enzyme activity. Although further studies are still needed, inhibition of the enzyme activity may prove to be an effective tool for the treatment of several diseases such as obesity, osteoporosis and type 2 diabetes. Orv. Hetil., 2013, 154, 283–293.

scholarly journals Proliferative responses to altered 17β-hydroxysteroid dehydrogenase (17HSD) type 2 expression in human breast cancer cells are dependent on endogenous expression of 17HSD type 1 and the oestradiol receptors

2006 ◽  
Vol 13 (3) ◽  
pp. 875-884 ◽  
Author(s):  
A Jansson ◽  
C Gunnarsson ◽  
O Stål
Keyword(s):  
Breast Cancer ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Hydroxysteroid Dehydrogenase ◽  
S Phase ◽  
Phase Fraction ◽  
Mcf7 Cells ◽  
Endogenous Expression

The primary source of oestrogen in premenopausal women is the ovary but, after menopause, oestrogen biosynthesis in peripheral tissue is the exclusive site of formation. An enzyme group that affects the availability of active oestrogens is the 17β-hydroxysteroid dehydrogenase (17HSD) family. In breast cancer, 17HSD type 1 and type 2 have been mostly investigated and seem to be the principal 17HSD enzymes involved thus far. The question whether 17HSD type 1 or type 2 is of greatest importance in breast tumour development is still not clear. The aim of this study was to investigate how the loss of 17HSD type 2 expression, using siRNA in the non-tumour breast epithelial cells HMEC (human mammal epithelial cells) and MCF10A, and gain of 17HSD type 2 expression, using transient transfection in the breast cancer derived cell lines MCF7 and T47D, affect oestradiol conversion and proliferation rate measured as S-phase fraction. We further investigated how this was related to the endogenous expression of 17HSD type 1 and oestradiol receptors in the examined cell lines. The oestradiol level in the medium changed significantly in the MCF7 transfected cells and the siRNA-treated HMEC cells, but not in T47D or MCF10A. The S-phase fraction decreased in the 17HSD type 2-transfected MCF7 cells and the siRNA-treated HMEC cells. The results seemed to be dependent on the endogenous expression of 17HSD type 1 and the oestradiol receptors. In conclusion, we found that high or low levels of 17HSD type 2 affected the oestradiol concentration significantly. However, the response was dependent on the endogenous expression of 17HSD type 1. Expression of 17HSD type 1 seems to be dominant to 17HSD type 2. Therefore, it may be important to investigate a ratio between 17HSD type 1 and 17HSD type 2.

17β-Hydroxysteroid dehydrogenase Type 1 and Type 2: Association between mRNA expression and activity in cell lines

2006 ◽  
Vol 248 (1-2) ◽  
pp. 246-249 ◽  
Author(s):  
Joanna M. Day ◽  
Helena J. Tutill ◽  
Simon P. Newman ◽  
Atul Purohit ◽  
Harshani R. Lawrence ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Cell Lines ◽  
Hydroxysteroid Dehydrogenase ◽  
Expression And Activity

scholarly journals 11?-Hydroxysteroid dehydrogenase Type 1 in obesity and Type 2 diabetes

Diabetologia ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 1-11 ◽  
Author(s):  
T. M. Stulnig ◽  
W. Waldh�usl
Keyword(s):  
Type 2 Diabetes ◽  
Hydroxysteroid Dehydrogenase

An in vitro microdialysis methodology to study 11β-hydroxysteroid dehydrogenase type 1 enzyme activity in liver microsomes

2007 ◽  
Vol 370 (1) ◽  
pp. 26-37 ◽  
Author(s):  
Li Sun ◽  
Julie A. Stenken ◽  
Amy Y. Yang ◽  
Jamie J. Zhao ◽  
Donald G. Musson
Keyword(s):  
Enzyme Activity ◽  
Liver Microsomes ◽  
Hydroxysteroid Dehydrogenase

scholarly journals Cloning, expression and enzyme activity delineation of two novel CANT1 mutations: the disappearance of dimerization may indicate the change of protein conformation and even function

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Hong-Dan Wang ◽  
Liang-Jie Guo ◽  
Zhan-Qi Feng ◽  
Da-Wei Zhang ◽  
Meng-Ting Zhang ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Cloning And Expression ◽  
Expression Vectors ◽  
Extracellular Secretion ◽  
Chinese Origin ◽  
Desbuquois Dysplasia ◽  
Pathogenic Change ◽  
First Time

Abstract Background Desbuquois dysplasia (DBQD) was a rare autosomal recessive skeletal dysplasia. Calcium activated nucleotidase 1 (CANT1) mutation was identified as a common pathogenic change for DBQD type 1 and Kim variant but not for DBQD type 2. To our knowledge, all patients with DBQD type 1 currently found could be explained by mutations in the CANT1 gene, but mutations in the CANT1 gene might not be directly diagnosed as DBQD type 1. Results We have identified two novel CANT1 mutations (mut1: c.594G > A [p.Trp198*], mut2: c.734C > T [p.Pro245Leu]) in three children from a family of Chinese origin for the first time. Two of the three children could be diagnosed as typical DBQD type 1 and one child could not be diagnosed as DBQD type 1 based on the clinical data we had. To further clarify the effect of the two mutations of the CANT1 gene, we studied the CANT1 gene expression and detected the protein secretion and nucleotide enzyme activity through cDNA cloning and expression vectors construction for wild and mutant types. The mut1 was a nonsense mutation which could lead to premature termination and produced the truncated bodies; The CANT1 dimer of mut2 was significantly reduced and even undetectable. The extracellular secretion of mut1 was extremely high while mut2 was significantly reduced compared with the wild type. And mut1 and mut2 also could result in a significant reduction in the activity of CANT1 nucleotidease. From the results we could deduce that the two mutations of the CANT1 gene were the causes of the two cases in this study. Conclusions Regarding the particularity of the cases reported in this study, the pathogenesis of CANT1 might be more complicated. The genetic and phenotype of three children with the same genetic background need to be further studied. Larger cohort of patients was needed to establish genotype–phenotype correlations in DBQD.

Altered corticosteroid metabolism differentially affects pituitary corticotropin response

2002 ◽  
Vol 282 (2) ◽  
pp. E466-E473 ◽  
Author(s):  
Junko Hanafusa ◽  
Tomoatsu Mune ◽  
Tetsuya Tanahashi ◽  
Yukinori Isomura ◽  
Tetsuya Suwa ◽  
...  
Keyword(s):  
Glycyrrhizic Acid ◽  
Mrna Level ◽  
Hydroxysteroid Dehydrogenase ◽  
Corticotropin Releasing Factor ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Basal Plasma ◽  
Corticosterone Response ◽  
Pituitary Adrenal Axis

To evaluate the effects of altered corticosteroid metabolism on the hypothalamic-pituitary-adrenal axis, we examined rats treated with glycyrrhizic acid (G rats) or rifampicin (R rats) for 7 days. The half-life of exogenously administered hydrocortisone as a substitute for corticosterone was longer in G rats and shorter in R rats, with no differences in basal plasma levels of ACTH or corticosterone. The ACTH responses to human corticotropin-releasing factor (CRF) or insulin-induced hypoglycemia were greater in G rats and tended to be smaller in R rats compared with those in the control rats, whereas the corticosterone response was similar. No difference was observed in the content and mRNA level of hypothalamic CRF among the groups. The number and mRNA level of CRF receptor and type 1 11β-hydroxysteroid dehydrogenase (11-HSD1) mRNA level in the pituitary were increased in G rats but not changed in R rats, suggesting that chronically increased intrapituitary corticosterone upregulates pituitary CRF receptor expression. In contrast, CRF mRNA levels in the pituitary were increased in R rats. Our data indicate novel mechanisms of corticosteroid metabolic modulation and the involvement of pituitary 11-HSD1 and CRF in glucocorticoid feedback physiology.

scholarly journals Differential expression and regulation of ryanodine receptor and myo-inositol 1,4,5-trisphosphate receptor Ca2+ release channels in mammalian tissues and cell lines

1997 ◽  
Vol 327 (1) ◽  
pp. 251-258 ◽  
Author(s):  
John J. MACKRILL ◽  
R. A. John CHALLISS ◽  
D. A. O'CONNELL ◽  
F. Anthony LAI ◽  
Stefan R. NAHORSKI
Keyword(s):  
Cell Lines ◽  
Mammalian Cell ◽  
Release Channel ◽  
Chronic Stimulation ◽  
Channel Proteins ◽  
Mammalian Cell Lines ◽  
Rabbit Tissues ◽  
Stimulation Of

Ryanodine receptors (RyRs) and Ins(1,4,5)P3 receptors (Ins(1,4,5)P3Rs) represent two multigene families of channel proteins that mediate the release of Ca2+ ions from intracellular stores. In the present study, the expression patterns of these channel proteins in mammalian cell lines and tissues were investigated by using isoform-specific antibodies. All cell lines examined expressed two or more Ins(1,4,5)P3R isoforms, with the type 1 Ins(1,4,5)P3R being ubiquitous. RyR isoforms were detected in only six out of eight cell lines studied. Similarly, of the nine rabbit tissues examined, RyR protein expression was detected only in brain, heart, skeletal muscle and uterus. Specific [3H]ryanodine binding was found in a number of rabbit tissues, although it was not detected in mammalian cell lines. Subcellular fractionation of SH-SY5Y human neuroblastomas revealed that the type 2 RyR and type 1 Ins(1,4,5)P3R co-localize among the fractions of a sucrose-cushion separation of crude microsomal membrane fractions. Manipulation of SH-SY5Y cells by chronic stimulation of muscarinic acetylcholine receptor (mAChR) results in a decrease in their type 1 Ins(1,4,5)P3R levels but not in the abundance of the type 2 RyR. Differentiation of these neuroblastomas by using retinoic acid did not detectably alter their expression of Ca2+-release channel proteins. Finally, differentiation of BC3H1 cells affects the expression of their Ca2+-release channel proteins in an isoform-specific manner. In summary, this study demonstrates that mammalian cell lines display distinct patterns of Ca2+-release channel protein expression. The abundance of these proteins is differentially regulated during phenotypic modifications of a cell, such as differentiation or chronic stimulation of mAChR.

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