Comparison of Osteogenic Potential of Phenytoin with Dexamethasone in Cultured Dental Pulp Stem Cells

Phenytoin regulates osteogenic differentiation of human bone marrow stem cells by PI3K/Akt pathway

Background

We mainly studied the mechanism by which phenytoin promotes osteogenic differentiation of human jawbone marrow stem cells.

Methods

Bone marrow stem cells were extracted from jaw bone tissue debris obtained from 5 subjects undergoing implant restoration. Osteogenic and adipogenic experiments proved cells stemness, and the expression of ALP, RUNX2, and OSX were detected by qPCR and Western blot. High-throughput sequencing was used to extract differentially expressed genes, the network database predicted phenytoin drug targets, GO and KEGG enrichment combined with PPI network diagram to analyze the osteogenesis mechanism.

Results

Calcium nodules and lipid droplet formation were observed in osteogenic and adipogenic experiments. The concentration of phenytoin within 100 mg/L does not produce cytotoxicity. The results of PCR and WB indicated that 50 mg/L phenytoin significantly promoted the expression of ALP and RUNX2, and 25 mg/L phenytoin significantly promoted the expression of OSX. The results of network pharmacology suggest that phenytoin promotes bone formation by up-regulating FGFR2, S1PR1, TGFB3, VCAN core proteins and activating PI3K/Akt pathway.

Conclusions

Phenytoin activated the PI3K/Akt pathway to regulate the osteogenic differentiation of human jawbone marrow stem cells. https://data.mendeley.com/datasets/t3xstktt93/1.

Therapeutic Potential of Mesenchymal Stem Cells in the Treatment of Epilepsy and Their Interaction with Antiseizure Medications

Epilepsy is a life-threatening neurological disease that affects approximately 70 million people worldwide. Although the vast majority of patients may be successfully managed with currently used antiseizure medication (ASM), the search for alternative therapies is still necessary due to pharmacoresistance in about 30% of patients with epilepsy. Here, we review the effects of ASMs on stem cell treatment when they could be, as expected, co-administered. Indeed, it has been reported that ASMs produce significant effects on the differentiation and determination of stem cell fate. In addition, we discuss more recent findings on mesenchymal stem cells (MSCs) in pre-clinical and clinical investigations. In this regard, their ability to differentiate into various cell types, reach damaged tissues and produce and release biologically active molecules with immunomodulatory/anti-inflammatory and regenerative properties make them a high-potential therapeutic tool to address neuroinflammation in different neurological disorders, including epilepsy. Overall, the characteristics of MSCs to be genetically engineered, in order to replace dysfunctional elements with the aim of restoring normal tissue functioning, suggested that these cells could be good candidates for the treatment of epilepsy refractory to ASMs. Further research is required to understand the potential of stem cell treatment in epileptic patients and its interaction with ASMs.

Phenytoin Is Promoting the Differentiation of Dental Pulp Stem Cells into the Direction of Odontogenesis/Osteogenesis by Activating BMP4/Smad Pathway

Background

The purpose of this study was the evaluation of the potential and mechanism of phenytoin to promote differentiation of human dental pulp stem cells (hDPSC) into odontoblasts/osteoblasts.

Methods

Fourth-generation human hDPSC originating from healthy pulp of third molars was cultured in control as well as phenytoin-containing media (PHT) for 14 days. qPCR was applied to detect the expression of DSPP, DMP1, and ALP genes. Western blot analysis was used to confirm the findings. One-way analysis of variance (ANOVA) was used for statistical analysis (p < 0.05). Information about phenytoin was assessed from PubChem database, while targets of phenytoin were assessed from six databases. Drug targets were extracted based on the differentially expressed genes (‖logFC‖ ≥ 1, p < 0.05) in the experimental group (50 mg/L PHT, 14 days). GO BP and KEGG pathway enrichment analysis on the obtained drug targets was performed and the target protein functional network diagram was constructed.

Results

A concentration below 200 mg/L PHT had no obvious toxicity to hDPSC. The expression of DSPP, DMP1, and ALP genes in the 50 mg/L PHT concentration group increased significantly. The WB experiment showed that the protein content of BMP4, Smad1/5/9, and p-Smad1/5 was significantly increased in 50 mg/L PHT in comparison with the NC group (the group without treatment of PHT) at 14 days.

Conclusion

Phenytoin has the ability of promoting the differentiation of hDPSC into odontoblasts and osteoblasts. BMP4/Smad pathway, inducing odontogenic/osteogenic differentiation of hDPSC, appears a main process in this context.

Suppressive effects of dental pulp stem cells and its conditioned medium on development and migration of colorectal cancer cells through MAPKinase pathways

OBJECTIVES

Mesenchymal stem cells (MSCs) extensively interact with cancer cells and other stromal cells in the tumor microenvironment. However, the role of MSCs in colorectal cancer (CRC) development and metastasis is controversial. Strong evidence demonstrated that conditioned medium (CM) obtained from MSCs regulates main cellular functions such as proliferation, differentiation, migration, and communication due to its cell secretomes. This study was designed to determine the inhibitory effect of dental pulp stem cells (DPSC) and its extracted conditioned medium (DPSC-CM) in CRC progression.

MATERIALS AND METHODS

The inhibitory effects of DPSC-CM on growth, apoptosis, and migration of CRC cells were evaluated by resazurin, flow cytometry of propidium iodide (PI) stained cells, and wound closure assay, respectively. Western blotting detected the expression of MAPKinase and apoptotic proteins. Also, the homing ability of DPSCs and the invasion ability of CRC cells under indirect co-culture were assayed by the Boyden chamber assay.

RESULTS

DPSC-CM reduced the viability and induced the apoptosis of CRC cells significantly. Western blot analysis confirmed the increase in cytochrome C, phospho-JNK/SAPK to JNK/SAPK ratio, cleaved-caspase 8 and 3 in treated CRC cells with DPSC-CM, and decrease in phospho-ERK (P44/42 MAPK) to ERK (P44/42 MAPK) ratio, which are involved in induction of apoptosis and growth inhibition of cancer cells with minimal change in normal cells. Also, DPSCs could migrate (homing ability) to Caco₂ and SW48 cells significantly.

CONCLUSION

To sum up, DPSC-CM had significant apoptotic and growth inhibitory effects on the CRC cells through the MAPKinase and apoptosis signaling pathways.

An insight into the implications of estrogen deficiency and transforming growth factor β in antiepileptic drugs-induced bone loss

There have been a number of reports that chronic antiepileptic drug (AEDs) therapy is associated with abnormal bone and calcium metabolism, osteoporosis/osteomalacia, and increased risk of fractures. Bony adverse effects of long term antiepileptic drug therapy have been reported for more than four decades but the exact molecular mechanism is still lacking. Several mechanisms have been proposed regarding AEDs induced bone loss; Hypovitaminosis D, hyperparathyroidism, estrogen deficiency, calcitonin deficiency. Transforming growth factor-β (TGF- β) is abundant in bone matrix and has been shown to regulate the activity of osteoblasts and osteoclasts in vitro. All isoforms of TGF- β are expressed in bone and intricately play role in bone homeostasis by modulating estrogen level. Ovariectomised animal have shown down regulation of TGF- β in bone that could also be a probable target of AEDs therapy associated bone loss. One of the widely accepted hypotheses regarding the conventional drugs induced bone loss is hypovitaminosis D which is by virtue of their microsomal enzyme inducing effect. However, despite of the lack of enzyme inducing effect of certain newer antiepileptic drugs, reduced bone mineral density with these drugs have also been reported. Thus an understanding of bone biology, pathophysiology of AEDs induced bone loss at molecular level can aid in the better management of bone loss in patients on chronic AEDs therapy. This review focuses mainly on certain new molecular targets of AEDs induced bone loss.

Pre-Transplantation Serum Parathyroid Hormone Influences the Number of Mobilized CD34+ Hematopoietic Stem Cells in Autologous Hematopoietic Stem Cell Transplantation

Background

Parathyroid hormone (PTH) is a calcium homeostasis regulator and can affect bone marrow niche. PTH leads to the bone marrow stem cell niche expansion as well as the induction of stem cell mobilization from the bone marrow into peripheral blood. In this study, we evaluated the association between pre- transplantation serum PTH levels and the number of circulating CD34+ cells along with the platelets/white blood cells (Plt/WBC) engraftment in patients who underwent autologous Hematopoietic Stem Cell Transplantation.

Methods

Subjects for the study were 100 patients who received autologous hematopoietic stem cell transplantation (auto-HSCT), retrospectively. Serum levels of PTH, calcium, phosphorus, and alkaline phosphatase were measured before mobilization. Their impacts were measured on the number of mobilized CD34+ hematopoietic stem cells, and Plt/WBC engraftment.

Results

High levels of serum PTH (> 63.10 pg/mL) was significantly associated with higher number of CD34+ cells in peripheral blood after granulocyte- colony stimulating factor (G-CSF)-induced mobilization (p= 0.079*). Serum calcium at low levels were associated with higher number of circulating CD34+ cells post mobilization. Pre- transplantation serum levels of phosphorus and alkaline phosphatase on CD34+ numbers were not statistically significant. Serum Plt/WBC engraftment was not improved in presence of high levels of serum PTH.

Conclusion

We suggested that serum PTH levels before transplantation could be influential in raising the number of circulating CD34+ hematopoietic stem cell after mobilization.