Intermittent administration of PTH induces the expression of osteocalcin and BMP-2 on choroid plexus cells associated with suppression of sclerostin, TGF-β1, and Na+K+ATPase

Pulp stones and kidney stones-related gene: An investigation of single nucleotide polymorphisms in the gene encoding parathyroid hormone

Introduction

Pulp stones (PS), whose origins remain unclear, present a challenge for clinical practice in Endodontics. Similar to other calcifications, a relationship with parathyroid hormone is hypothesized.

Purpose

The aim of this study was to investigate the association between the presence of PS and kidney stones (KS) and single nucleotide polymorphisms (SNPs) in the parathyroid hormone (PTH) gene, which is related to KS.

Methods

This cross-sectional study included adults of both sexes, divided into groups: with PS and without PS. PS diagnosis was based on radiographic evaluation. Saliva samples were collected from all participants, and prior history of KS was recorded. The samples were processed, and genomic DNA was used to genotype the rs694, rs6256, and rs307247 SNPs. The Hardy-Weinberg equilibrium was assessed using the Chi-square test. Genotypic and allelic profiles under additive, dominant, and recessive models were evaluated using a univariate logistic regression model and the Wald test, with analyses conducted in SPSS® version 23.0. Additionally, Fisher's exact test was used to compare the haplotype frequencies. Statistical significance was set at 5 %.

Results

The study included 63 patients with PS and 54 without PS, with a mean age of 32.5 years. No statistically significant association was observed between the groups regarding the presence of KS. Allelic and genotypic analyses revealed no significant association (P > 0.05) between the presence of PS and SNPs analyzed in the groups studied.

Conclusion

None of the SNPs studied in the gene encoding PTH were associated with PS or KS.

Dose of alendronate directly increases trabeculae expansivity without altering bone volume in rat femurs

AIM

To evaluate the effects of sodium alendronate on bone repair in fractures created in appendicular bones.

METHODS

Wistar rats (n = 36) were allocated into three distinct groups: group C (control), group B1 (received 1 mg/kg of alendronate), and group B2 (received 3 mg/kg of alendronate). The rats underwent femoral transversal linear fracture surgery using stable internal fixation with a 2.0 mm plate and screw system. Each animal randomly received intraperitoneal applications of sodium alendronate at a dose corresponding to group B1 or B2 three times a week, while the control group received a 0.9% saline solution. Drug administration was performed until euthanasia at 45 d. The femurs were removed and each surgical piece was sent for radiographic, tomographic and microtomographic analysis. Data were submitted to descriptive and inferential statistical analysis (95% confidence interval).

RESULTS

Quantitative evaluations of bone neoformation did not show differences among the groups in the radiographic (P = 0.341), microtomographic (P = 0.581) and tomographic evaluations (P = 0.171). In the qualitative microtomographic analysis, a smaller distance was observed between the internal bone trabeculae in the groups that used alendronate (P = 0.05). On the other hand, group B2 had a higher amount of bone trabeculae per unit length when compared to the other groups (P = 0.04).

CONCLUSION

It is likely that the use of alendronate did not have a direct influence on the amount of bone neoformation, however it did influence the bone quality in a dose-dependent manner, ultimately affecting the distance and quantity of the trabeculae.

The effect of vitamin D and zoledronic acid in bone marrow adiposity in kidney transplant patients: A post hoc analysis

PURPOSE

Osteoblasts and adipocytes are derived from mesenchymal stem cells. An imbalance in the differentiation of these lineages could affect the preservation of bone integrity. Several studies have suggested the importance of this imbalance in the pathogenesis of osteoporosis after kidney transplant (KT), but the role of bone marrow adiposity in this process is not well known, and if the treatment with the anti-absorptive (zoledronic acid-ZA) drugs could attenuate bone loss. Thus, our objective was compare bone marrow adiposity, osteoblasts and osteocytes before and after KT, verify an association between bone remodeling process (Turnover, Volume, and Mineralization-TMV classification), the osteocyte sclerostin expression to evaluate if there is a role of Wnt pathway, as well as the effect of ZA on these cells.

METHODS

We studied 29 new living-donor KT patients. One group received ZA at the time of KT plus cholecalciferol for twelve months, and the other group received only cholecalciferol. Bone biopsies were performed at baseline and after 12 months of treatment. Histomorphometric evaluation was performed in bone and bone marrow adipocytes. Sclerostin (Scl) expression in osteocytes was evaluated by immunohistochemistry.

RESULTS

Some bone marrow adiposity parameters were increased before KT. After KT, some of them remained increased and they worsened with the use of ZA. In the baseline, lower bone Volume and Turnover, were associated with increased bone marrow adiposity parameters (some of them). After KT, both groups showed the same associations. Osteocyte Scl expression after KT decreased with the use of ZA. We observed also an inverse association between bone adiposity parameters and lower osteocyte sclerostin expression 12 months after KT.

CONCLUSION

In conclusion, the present study suggests that KT fails to normalize bone marrow adiposity, and it even gets worse with the use of ZA. Moreover, bone marrow adiposity is inversely associated with bone Volume and Turnover, which seems to be accentuated by the antiresorptive therapy.