scholarly journals Large‐scale in vitro functional testing and novel variant scoring via protein modeling provide insights into alkaline phosphatase activity in hypophosphatasia

2020 ◽  
Vol 41 (7) ◽  
pp. 1250-1262 ◽  
Author(s):  
Guillermo Angel ◽  
John Reynders ◽  
Christopher Negron ◽  
Thomas Steinbrecher ◽  
Etienne Mornet
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Large Scale ◽  
Protein Modeling ◽  
Functional Testing ◽  
Novel Variant

The inhibitory effects of vancomycin on rat bone marrow–derived mesenchymal stem cell differentiation

2021 ◽  
pp. 1-5
Author(s):  
Kari Hanson ◽  
Carly Isder ◽  
Kristen Shogren ◽  
Anthony L. Mikula ◽  
Lichun Lu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Alkaline Phosphatase ◽  
Osteogenic Differentiation ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
High Dose ◽  
Inhibitory Effects ◽  
Alizarin Red ◽  
Osteogenic Factors

OBJECTIVE The use of intrawound vancomycin powder in spine surgery has been shown to decrease the rate of surgical site infections; however, the optimal dose is unknown. High-dose vancomycin inhibits osteoblast proliferation in vitro and may decrease the rate of solid arthrodesis. Bone marrow–derived mesenchymal stem cells (BMSCs) are multipotent cells that are a source of osteogenesis in spine fusions. The purpose of this study was to determine the effects of vancomycin on rat BMSC viability and differentiation in vitro. METHODS BMSCs were isolated from the femurs of immature female rats, cultured, and then split into two equal groups; half were treated to stimulate osteoblastic differentiation and half were not. Osteogenesis was stimulated by the addition of 50 µg/mL l-ascorbic acid, 10 mM β-glycerol phosphate, and 0.1 µM dexamethasone. Vancomycin was added to cell culture medium at concentrations of 0, 0.04, 0.4, or 4 mg/mL. Early differentiation was determined by alkaline phosphatase activity (4 days posttreatment) and late differentiation by alizarin red staining for mineralization (9 days posttreatment). Cell viability was determined at both the early and late time points by measurement of formazan colorimetric product. RESULTS Viability within the first 4 days decreased with high-dose vancomycin treatment, with cells receiving 4 mg/mL vancomycin having 40%–60% viability compared to the control. A gradual decrease in alizarin red staining and nodule formation was observed with increasing vancomycin doses. In the presence of the osteogenic factors, vancomycin did not have deleterious effects on alkaline phosphatase activity, whereas a trend toward reduced activity was seen in the absence of osteogenic factors when compared to osteogenically treated cells. CONCLUSIONS Vancomycin reduced BMSC viability and impaired late osteogenic differentiation with high-dose treatment. Therefore, the inhibitory effects of high-dose vancomycin on spinal fusion may result from both reduced BMSC viability and some impairment of osteogenic differentiation.

The influence of titanium surfaces treated by alkalis on macrophage and osteoblast-like cell adhesion and gene expression in vitro

RSC Advances ◽  
2015 ◽  
Vol 5 (99) ◽  
pp. 81378-81387 ◽  
Author(s):  
Ting Ma ◽  
Xi-Yuan Ge ◽  
Sheng-Nan Jia ◽  
Xi Jiang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Cell Adhesion ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Related Gene ◽  
Titanium Surfaces

The effect of alkali-treated titanium surfaces on inflammation-related gene expression of macrophages and alkaline phosphatase activity of osteoblast-like cells.

Acidosis inhibits osteoblastic and stimulates osteoclastic activity in vitro

1992 ◽  
Vol 262 (3) ◽  
pp. F442-F448 ◽  
Author(s):  
N. S. Krieger ◽  
N. E. Sessler ◽  
D. A. Bushinsky
Keyword(s):  
Alkaline Phosphatase ◽  
Metabolic Acidosis ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Collagen Synthesis ◽  
Calcium Flux ◽  
Osteoclastic Activity ◽  
Glucuronidase Activity

Metabolic acidosis induces net calcium flux (JCa) from cultured neonatal mouse calvariae through physicochemical and cell-mediated mechanisms. To determine the role of osteoblasts in acid-induced JCa, collagen synthesis and alkaline phosphatase activity were assessed in calvariae incubated in reduced pH and bicarbonate medium, a model of metabolic acidosis (Met), and compared with controls (Ctl). Collagen synthesis fell from 30.5 +/- 1.1 in Ctl to 25.1 +/- 0.4% with Met, and alkaline phosphatase decreased from 403 +/- 25 in Ctl to 298 +/- 21 nmol Pi.min-1.mg protein-1 with Met. During acidosis JCa was correlated inversely with percent collagen synthesis (r = -0.743, n = 11, P = 0.009) and with alkaline phosphatase activity (r = -0.453, n = 22, P = 0.034). To determine the role of osteoclasts in acid-induced JCa, osteoclastic beta-glucuronidase activity was determined in Ctl and Met in the absence or presence of the osteoclastic inhibitor calcitonin (CT, 3 x 10(-9) M). Met increased beta-glucuronidase (5.9 +/- 0.2) compared with Ctl (4.6 +/- 0.3 micrograms phenolphthalein released.bone-1.h-1), whereas CT inhibited beta-glucuronidase in both Ctl and Met (3.1 +/- 0.2 and 3.5 +/- 0.3, respectively). During acidosis JCa was correlated directly with beta-glucuronidase activity (r = 0.683, n = 42, P less than 0.001). Thus the cell-mediated component of JCa during acidosis in vitro appears to result from a combination of inhibited osteoblastic and stimulated osteoclastic activity.

scholarly journals Endocrine Relationships of Leukocyte Alkaline Phosphatase

Blood ◽  
1965 ◽  
Vol 25 (3) ◽  
pp. 356-369 ◽  
Author(s):  
FRED ROSNER ◽  
STANLEY L. LEE
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Mean Value ◽  
Conclusive Evidence ◽  
In Vitro Tests ◽  
Enzyme Release ◽  
Men And Women ◽  
Leukocyte Alkaline Phosphatase

Abstract Leukocyte alkaline phosphatase activity has been noted to be different in men and women. The mean leukocyte alkaline phosphatase activity for 74 normal men, aged 19 to 60 years, was 23 mg. of phosphorus per 1010 polvmorphonuclear leukocytes per hour. The corresponding mean value for 75 normal young women, age 19-48 years, was 35 (p < .001). No significant differences between boys and girls occurred until the time of puberty. After the menopause, the values for women approached the values for men. Women treated with androgens had lower leukocyte alkaline phosphatase activity than did control women. These results suggest that androgenic hormones inhibit this enzyme, and that other, as yet undefined endocrine influences, also affect its level of activity. In vitro tests with various concentrations of androgens and estrogens failed to provide conclusive evidence of direct effect on leukocytes although some degree of direct inhibition by androgens was suggested. Studies using saponin to effect enzyme release from leukocyte granules did not demonstrate whether the differences between men and women are differences of enzyme release or of content of leukocyte alkaline phosphatase.

scholarly journals A New 9,11-Secosterol from the Vietnamese Sea Soft Coral, Sarcophyton Mililatensis, Increases the Function of Osteoblastic MC3T3-E1 Cells

2007 ◽  
Vol 2 (11) ◽  
pp. 1934578X0700201 ◽  
Author(s):  
Chau Van Minh ◽  
Nguyen Xuan Cuong ◽  
Tran Anh Tuan ◽  
Eun Mi Choi ◽  
Young Ho Kim ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Bone Formation ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Soft Coral ◽  
Chemical Investigation ◽  
Significant Elevation ◽  
Prevention Of Osteoporosis ◽  
Polyhydroxylated Sterols

Chemical investigation of the Vietnamese soft coral Sarcophyton mililatensis resulted in the isolation of a new 9,11-secosterol, sarcomilasterol (1), along with two known polyhydroxylated sterols, sarcoaldesterol B (2) and ergosta-1β,3β,5α,6β-tetraol (3). Their structures were established on the basis of NMR spectroscopic and MS experiments. Compound 1 (3 μM) significantly increased the growth of MC3T3-E1 cells and caused a significant elevation of alkaline phosphatase activity and nodules mineralization compared to those of the control (P<0.05). These results suggest that compound 1 has a direct stimulatory effect on bone formation in vitro and may contribute to the prevention of osteoporosis.

scholarly journals A biodegradable porous composite scaffold of PCL/BCP containing Ang-(1-7) for bone tissue engineering

Cerâmica ◽  
2012 ◽  
Vol 58 (348) ◽  
pp. 481-488 ◽  
Author(s):  
F. A. Macedo ◽  
E. H. M. Nunes ◽  
W. L. Vasconcelos ◽  
R. A. Santos ◽  
R. D. Sinisterra ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Composite Scaffold ◽  
Weight Ratio ◽  
High Porosity ◽  
X Rays ◽  
Solvent Casting

Highly porous three-dimensional biodegradable scaffolds was obtained from beta-tricalcium phosphate-hydroxyapatite bioceramic (BCP), PCL, and Angiotensin-(1-7). We used the solvent casting and particulate leaching methods (SC/PL). The processed scaffolds were characterized by X-ray microtomography (µ-CT). Biocompatibility tests in vitro were performed during three and seven days using MTT and Alkaline Phosphatase Activity (APA) assays. Both the MTT activity and APA were evaluated using a one-way ANOVA test. The µ-CT results showed that the increase of the PCL:BCP weight ratio leads to structures with lower pore sizes. The pore interconnectivity of the processed scaffolds was evaluated in terms of the fragmentation index (FI). We observed that the obtained composites present poorly connected structures, with close values of FI. However, as the polymer phase is almost transparent to the X-rays, it was not taken into consideration in the µ-CT tests. The MTT activity assay revealed that scaffolds obtained with and without Angiotensin-(1-7) present mild and moderate cytotoxic effects, respectively. The APA assay showed that the rat osteoblasts, when in contact for three days with the PCL composites, presented an APA similar to that observed for the control cells. Nevertheless, for an incubation time of seven days we observed a remarkable decrease in the alkaline phosphatase activity. In conclusion, using the solvent casting and salt leaching method we obtained 3D porous that are composites of PCL, BC and Ang-(1-7), which have suitable shapes for the bone defects, a high porosity and interconnect pores. Furthermore, the viability in vitro showed that the scaffolds have potential for drug delivery system and could be used in future in vivo tests.

Triiodothyronine stimulates cartilage growth and maturation by different mechanisms

1987 ◽  
Vol 252 (2) ◽  
pp. E176-E182 ◽  
Author(s):  
W. M. Burch ◽  
J. J. Van Wyk
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Growth Plate ◽  
Alkaline Phosphatase Activity ◽  
Growth Response ◽  
Growth Effect ◽  
Cartilage Growth ◽  
Growth Plate Cartilage ◽  
Cartilage Differentiation

The mechanisms by which triiodothyronine (T3) stimulates growth and maturation of growth-plate cartilage in vitro were studied by incubating embryonic chick pelvic cartilages in serum-free medium in the presence and absence of T3 for 3 days. To determine whether T3 might stimulate production of somatomedins by the cartilage, medium from cartilage incubated with and without T3 was assayed for somatomedin C (Sm-C) by radioimmunoassay. No difference in Sm-C content was found. However, cartilage incubated with T3 and increasing amounts of human Sm-C (0.5-20 ng/ml) weighed more and had greater amounts of glycosaminoglycan than cartilage incubated in the same concentrations of Sm-C without T3, suggesting that T3 enhances the growth effect of somatomedin. We added a monoclonal antibody to Sm-C (anti-Sm-C) to the organ culture to determine whether T3's stimulatory effect on cartilage growth could be blocked. The anti-Sm-C inhibited growth of cartilage incubated in medium alone and blocked the growth response to T3. By using alkaline phosphatase as a biochemical marker to follow maturation, we found that T3 stimulated a 57% increase in alkaline phosphatase activity above cartilage incubated in medium alone and that anti-Sm-C did not inhibit T3's stimulatory effect on alkaline phosphatase activity. We propose two different mechanisms by which T3 affects growth-plate cartilage: T3 promotes cartilage growth primarily through enhancing the effect of somatomedin, and T3 stimulates cartilage maturation possibly by accelerating the normal process of cartilage differentiation from proliferative to hypertrophic chondrocytes.

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