scholarly journals Haptoglobin-stimulated bone resorption in neonatal mouse calvarial bones in vitro

1992 ◽  
Vol 35 (5) ◽  
pp. 587-591 ◽  
Author(s):  
Ulf H. Lerner ◽  
Nils Fröhlander
1992 ◽  
Vol 12 (5) ◽  
pp. 407-411 ◽  
Author(s):  
Östen Ljunggren ◽  
Sverker Ljunghall

Bone resorption, in vitro, is often measured as the release of prelabelled45Ca from neonatal mouse calvarial bones, or from fetal rat long bones. In this report we describe a technique to measure the breakdown of bone-matrix, in vitro. We also describe a new way to dissect neonatal mouse calvarial bones, in order to obtain large amounts of bone samples. Twelve bone fragments were dissected out from each mouse calvaria and were thereafter cultured in CMRL 1066 culture medium in serum-free conditions in 0.5 cm2 multiwell culture dishes. Matrix degradation after treatment with parathyroid hormone was assessed by measuring the amount of carboxyterminal telopeptide of type I collagen (ICTP) by RIA. The data on matrix degradation was compared to the release of prelabelled45Ca from neonatal mouse calvarial bones. We found that the dose-responses for parathyroid hormone-induced release of prelabelled45Ca and ICTP were identical. In conclusion: RIA-analysis of the ICTP-release is an easy and accurate method to measure degradation of bone-matrix, in vitro. Furthermore, the new dissection technique, described in this report, makes it easy to obtain large amounts of bone samples and thus to perform extensive experiments, e.g. dose-responses for agents that enhance bone resorption.


1997 ◽  
Vol 155 (3) ◽  
pp. 513-521 ◽  
Author(s):  
HH Conaway ◽  
D Grigorie ◽  
UH Lerner

Differential effects on in vitro bone resorption were observed when the glucocorticoids, hydrocortisone and dexamethasone, were added to neonatal mouse calvariae treated with either parathyroid hormone (PTH), 1,25(OH)2-vitamin D3, all trans-retinoic acid (t-RA), or prostaglandin E2 (PGE2). Bone resorption was assessed by analyzing either the release of 45Ca from [45Ca]CaCl2 prelabeled calvarial bones or the release of 3H from [3H]proline prelabeled calvariae. At PGE2 concentrations of 3 x 10(-8) and 3 x 10(-7) mol/l, co-treatment with either 10(-6) mol/l dexamethasone or 10(-6) mol/l hydrocortisone caused additive 45Ca release from neonatal mouse calvariae. In contrast, synergistic release from mouse calvarial bones of both 45Ca and 3H was found after either 10(-6) mol/l hydrocortisone or 10(-6) mol/l dexamethasone was combined with 3 x 10(-11) mol/l PTH treatment for 120 h. Dose-response studies indicated that the synergistic stimulation of 45Ca release from neonatal mouse calvariae by glucocorticoids and PTH could be elicited at glucocorticoid concentrations of 10(-8) to 10(-6) mol/l and at PTH concentrations of 10(-11) to 10(-9) mol/l. Progesterone and RU 38486 (a derivative of 19-nortestosterone with antiglucocorticoid activity) blocked the synergism noted with glucocorticoid and PTH co-treatment, suggesting that interaction between the steroids and PTH was dependent on glucocorticoid receptor interaction. Addition of either 10(-6) mol/l hydrocortisone or 10(-6) mol/l dexamethasone to neonatal mouse calvariae treated with 1,25(OH)2-vitamin D3 (10(-11) and 10(-10) mol/l) also resulted in synergistic stimulation of 45Ca release. In contrast to these observations, the stimulatory effect of t-RA (10(-8) mol/l) on 45Ca release from calvarial bones was abolished in the presence of 10(-6) mol/l dexamethasone. These results suggest that an important role of glucocorticoids may be to synergistically potentiate bone resorption stimulated by PTH and 1,25(OH)2-vitamin D3, but indicate an opposing interaction between the glucocorticoids and bone resorptive retinoids.


1986 ◽  
Vol 181 (3) ◽  
pp. 438-442 ◽  
Author(s):  
S. Gunasekaran ◽  
G. E. Hall ◽  
A. D. Kenny

1987 ◽  
Vol 114 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Chohei Shigeno ◽  
Itsuo Yamamoto ◽  
Shegiharu Dokoh ◽  
Megumu Hino ◽  
Jun Aoki ◽  
...  

Abstract. We have partially purified a tumour factor capable of stimulating both bone resorption in vitro and cAMP accumulation in osteoblastic ROS 17/2 cells from three human tumours associated with humoral hypercalcaemia of malignancy. Purification of tumour factor by sequential acid urea extraction, gel filtration and cation-exchange chromatography, reverse-phase high performance liquid chromatography followed by analytical isoelectric focussing provided a basic protein (pI > 9.3) with a molecular weight of approximately 13 000 as a major component of the final preparation which retained both the two bioactivities. Bone resorbing activity and cAMP-increasing activity in purified factor correlated with each other. cAMP-increasing activity of the factor was heat- and acid-stable, but sensitive to alkaline ambient pH. Treatment with trypsin destroyed cAMP-increasing activity of the factor. Synthetic parathyroid hormone (PTH) antagonist, human PTH-(3– 34) completely inhibited the cAMP-increasing activity of the factor. The results suggest that this protein factor, having its effects on both osteoclastic and osteoblastic functions, may be involved in development of enhanced bone resorption in some patients with humoral hypercalcaemia of malignancy.


Author(s):  
Natalie Aparecida Rodrigues Fernandes ◽  
Angelo Constantino Camilli ◽  
Laura Andrea Gonzalez Maldonado ◽  
Cindy Grace Pérez Pacheco ◽  
Amanda Favoreto Silva ◽  
...  
Keyword(s):  

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1982
Author(s):  
Wataru Ariyoshi ◽  
Shiika Hara ◽  
Ayaka Koga ◽  
Yoshie Nagai-Yoshioka ◽  
Ryota Yamasaki

Although the anti-tumor and anti-infective properties of β-glucans have been well-discussed, their role in bone metabolism has not been reviewed so far. This review discusses the biological effects of β-glucans on bone metabolisms, especially on bone-resorbing osteoclasts, which are differentiated from hematopoietic precursors. Multiple immunoreceptors that can recognize β-glucans were reported to be expressed in osteoclast precursors. Coordinated co-stimulatory signals mediated by these immunoreceptors are important for the regulation of osteoclastogenesis and bone remodeling. Curdlan from the bacterium Alcaligenes faecalis negatively regulates osteoclast differentiation in vitro by affecting both the osteoclast precursors and osteoclast-supporting cells. We also showed that laminarin, lichenan, and glucan from baker’s yeast, as well as β-1,3-glucan from Euglema gracilisas, inhibit the osteoclast formation in bone marrow cells. Consistent with these findings, systemic and local administration of β-glucan derived from Aureobasidium pullulans and Saccharomyces cerevisiae suppressed bone resorption in vivo. However, zymosan derived from S. cerevisiae stimulated the bone resorption activity and is widely used to induce arthritis in animal models. Additional research concerning the relationship between the molecular structure of β-glucan and its effect on osteoclastic bone resorption will be beneficial for the development of novel treatment strategies for bone-related diseases.


Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 619
Author(s):  
Hyun-Jung Park ◽  
Malihatosadat Gholam-Zadeh ◽  
Sun-Young Yoon ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi

Loss of ovarian function is closely related to estrogen (E2) deficiency, which is responsible for increased osteoclast (OC) differentiation and activity. We aimed to investigate the action mechanism of E2 to decrease bone resorption in OCs to protect from ovariectomy (OVX)-induced bone loss in mice. In vivo, tartrate-resistant acid phosphatase (TRAP) staining in femur and serum carboxy-terminal collagen crosslinks-1 (CTX-1) were analyzed upon E2 injection after OVX in mice. In vitro, OCs were analyzed by TRAP staining, actin ring formation, carboxymethylation, determination of reactive oxygen species (ROS) level, and immunoprecipitation coupled with Western blot. In vivo and in vitro, E2 decreased OC size more dramatically than OC number and Methyl-piperidino-pyrazole hydrate dihydrochloride (MPPD), an estrogen receptor alpha (ERα) antagonist, augmented the OC size. ERα was found in plasma membranes and E2/ERα signaling affected receptor activator of nuclear factor κB ligand (RANKL)-induced actin ring formation by rapidly decreasing a proto-oncogene tyrosine-protein kinase, cellular sarcoma (c-Src) (Y416) phosphorylation in OCs. E2 exposure decreased physical interactions between NADPH oxidase 1 (NOX1) and the oxidized form of c-Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), leading to higher levels of reduced SHP2. ERα formed a complex with the reduced form of SHP2 and c-Src to decrease c-Src activation upon E2 exposure, which blocked a signal for actin ring formation by decreased Vav guanine nucleotide exchange factor 3 (Vav3) (p–Y) and Ras-related C3 botulinum toxin substrate 1 (Rac1) (GTP) activation in OCs. E2/ERα signals consistently inhibited bone resorption in vitro. In conclusion, our study suggests that E2-binding to ERα forms a complex with SHP2/c-Src to attenuate c-Src activation that was induced upon RANKL stimulation in a non-genomic manner, resulting in an impaired actin ring formation and reducing bone resorption.


2021 ◽  
Vol 22 (7) ◽  
pp. 3616
Author(s):  
Ewelina Jozefczuk ◽  
Piotr Szczepaniak ◽  
Tomasz Jan Guzik ◽  
Mateusz Siedlinski

Sphingosine kinase-1 (Sphk1) and its product, sphingosine-1-phosphate (S1P) are important regulators of cardiac growth and function. Numerous studies have reported that Sphk1/S1P signaling is essential for embryonic cardiac development and promotes pathological cardiac hypertrophy in adulthood. However, no studies have addressed the role of Sphk1 in postnatal cardiomyocyte (CM) development so far. The present study aimed to assess the molecular mechanism(s) by which Sphk1 silencing might influence CMs development and hypertrophy in vitro. Neonatal mouse CMs were transfected with siRNA against Sphk1 or negative control, and subsequently treated with 1 µM angiotensin II (AngII) or a control buffer for 24 h. The results of RNASeq analysis revealed that diminished expression of Sphk1 significantly accelerated neonatal CM maturation by inhibiting cell proliferation and inducing developmental pathways in the stress (AngII-induced) conditions. Importantly, similar effects were observed in the control conditions. Enhanced maturation of Sphk1-lacking CMs was further confirmed by the upregulation of the physiological hypertrophy-related signaling pathway involving Akt and downstream glycogen synthase kinase 3 beta (Gsk3β) downregulation. In summary, we demonstrated that the Sphk1 silencing in neonatal mouse CMs facilitated their postnatal maturation in both physiological and stress conditions.


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