Cobalt Chloride as a Hypoxia Mimicking Agent Induced HIF-1α and mTOR Expressions of Human Umbilical Cord Mesenchymal Stem Cells

ABSTRACT Objective: To assess the effects of cobalt chloride (CoCl2) as a hypoxia mimicking agent on human umbilical cord mesenchymal stem cells (hUCMSCs) expression of HIF-1α and mTOR for use in regenerative dentistry. Material and Methods: Human umbilical cord mesenchymal stem cells were isolated and then cultured. The characteristics of stemness were screened and confirmed by flow cytometry. The experiment was conducted on hypoxia (H) and normoxia (N) groups. Each group was divided and incubated into 24-, 48-, and 72-hours observations. Hypoxic treatment was performed using 100 µM CoCl2 on 5th passage cells in a conventional incubator (37°C; 5CO2). Then, immunofluorescence of HIF-1α and mTOR was done. Data was analyzed statistically using One-way ANOVA and Tukey's HSD. Results: Significant differences were found between normoxic and hypoxic groups on HIF-1α (p=0.015) and mTOR (p=0.000) expressions. The highest HIF-1α expression was found at 48 hours in the hypoxia group, while for mTOR at 24 hours in the hypoxia group. Conclusion: Hypoxia using cobalt chloride was able to increase human umbilical cord mesenchymal stem cells expression of HIF-1α and mTOR.

Human umbilical cord mesenchymal stem cells accelerate and increase implant osseointegration in diabetic rats.

OBJECTIVE: This study was conducted to assess the effect of hUCMSCs injection on the osseointegration of dental implant in diabetic rats via Runt-related Transcription Factor 2 (Runx2), Osterix (Osx), osteoblasts, and Bone Implant Contact (BIC). METHODOLOGY: The research design was a true experimental design using Rattus norvegicus Wistar strain. Rattus norvegicus were injected with streptozotocin to induce experimental diabetes mellitus. The right femur was drilled and loaded with titanium implant. Approximately 1 mm from proximal and distal implant site were injected with hUCMSCs. The control group was given only gelatin solvent injection. After 2 and 4 weeks of observation, the rats were sacrificed for further examination around implant site using immunohistochemistry staining (RUNX2 and Osterix expression), hematoxylin eosin staining, and bone implant contact area. Data analysis was done using ANOVA test. RESULTS: Data indicated a significant difference in Runx2 expression (p<0.001), osteoblasts (p<0.009), BIC value (p<0.000), and Osterix expression (p<0.002). In vivo injection of hUCMSCs successfully increased Runx2, osteoblasts, and BIC value significantly, while decreased Osterix expression, indicating an acceleration of the bone maturation process. CONCLUSION: The results proved hUCMSCs to accelerate and enhance implant osseointegration in diabetic rat models.

Human umbilical cord mesenchymal stem cells induction in peri-implantitis Rattus norvegicus accelerates and enhances osteogenesis activity and implant osseointegration.

Peri-implantitis additional treatment generally aims to repair damaged tissue through a regenerative approach. Human umbilical cord mesenchymal stem cells (hUCMSCs) produce a high osteogenic effect and are capable of modulating the immune system by suppressing inflammatory response, modulating bone resorption, and inducing endogenous osteogenesis. AIM: This study was intended to discover the effect of hUCMSCs on an implant osseointegration process in peri-implantitis rat subjects as assessed by several markers including interleukin-10 (IL-10), transforming growth factor-ß (TGF-ß), receptor activator of nuclear factor kappa- ß ligand (RANKL), bone morphogenic protein (BMP-2), osterix (Osx), and osteoprotegerin (OPG). MATERIAL AND METHODS: The research design implemented during this study represented a true experimental design incorporating the use of Rattus norvegicus (Wistar strain) as subjects. RESULTS: Data analysed by means of a Brown Forsythe test indicated differences between the increase in BMP-2 expression (p < 0.000) and Osx expression (p < 0.001) and between RANKL expression (p < 0.001, Tukey HSD) and OPG expression (p < 0.000, Games Howell). CONCLUSION: According to the findings of this research, hUCMSCs induction is successful in accelerating and enhancing osteogenic activity and implant osseointegration in peri-implantitis rat subjects.

Human umbilical cord mesenchymal stem cells accelerate and increase implant osseointegration in diabetic rats

Abstract Objective This study was conducted to assess the effect of hUCMSCs injection on the osseointegration of dental implant in diabetic rats via Runt-related Transcription Factor 2 (Runx2), Osterix (Osx), osteoblasts, and Bone Implant Contact (BIC). Methodology The research design was a true experimental design using Rattus norvegicus Wistar strain. Rattus norvegicus were injected with streptozotocin to induce experimental diabetes mellitus. The right femur was drilled and loaded with titanium implant. Approximately 1 mm from proximal and distal implant site were injected with hUCMSCs. The control group was given only gelatin solvent injection. After 2 and 4 weeks of observation, the rats were sacrificed for further examination around implant site using immunohistochemistry staining (RUNX2 and Osterix expression), hematoxylin eosin staining, and bone implant contact area. Data analysis was done using ANOVA test. Results Data indicated a significant difference in Runx2 expression (p<0.001), osteoblasts (p<0.009), BIC value (p<0.000), and Osterix expression (p<0.002). In vivo injection of hUCMSCs successfully increased Runx2, osteoblasts, and BIC value significantly, while decreased Osterix expression, indicating an acceleration of the bone maturation process. Conclusion The results proved hUCMSCs to accelerate and enhance implant osseointegration in diabetic rat models.

Propolis extract and bovine bone graft combination in the expression of VEGF and FGF2 on the preservation of post extraction socket.

AIM: To determine the potential of propolis extract and BBG combination on the quantity of fibroblast growth factor 2 (FGF-2), vascular endothelial growth factor (VEGF), and osteoblasts in the preservation of tooth extraction socket on days 3 and 7. SETTINGS AND DESIGN: Laboratory in vivo reseach using animal model. MATERIALS AND METHODS: Fifty-six Cavia cobaya were divided into eight groups containing seven animals in each group. The extraction socket on the lower left incisor was filled with polyethylene glycol (PEG) at a concentration of 2% (Groups I and II) as a control; active materials consisted of propolis extract and PEG (Groups III and IV); active materials consisted of BBG and PEG (Groups V and VI); and active materials consisted of propolis extract, BBG, and PEG (Groups VII and VIII). Then, an examination was done using immunohistochemistry to perform an expression of VEGF, FGF2, as well as histology of osteoblasts. STATISTICAL ANALYSIS USED: The statistical analysis performed using a one-way ANOVA and Tukey's honestly significant difference test. RESULTS: Propolis extract, BBG and PEG had the most significant result related to the formation of FGF2, VEGF, and osteoblasts. CONCLUSION: The combination of propolis extract with BBG and PEG in socket preservation is effective in increasing the expression of FGF2, VEGF, and osteoblasts.

The role of the combination of Moringa oleifera leaf extract and demineralized freeze-dried bovine bone xenograft (xenograft) as tooth extraction socket preservation materials on osteocalcin and transforming growth factor-beta 1 expressions in alveolar bone of Cavia cobaya.

AIM: Alveolar bone resorption, often occurring after tooth extraction, can be minimized through socket preservation. This process uses a combination of Moringa leaf extract and demineralized freeze-dried bovine bone xenograft (DFDBBX) that is expected to generate both transforming growth factor-beta 1 (TGF-ß1) expressions as a transcription factor associated with osteoblast differentiation and osteocalcin accelerating alveolar bone formation. This research aimed to analyze the role of the combination of Moringa leaf extract and DFDBBX induced in socket preservation when generating TGF-ß1 and osteocalcin expressions. MATERIALS AND METHODS: The left mandibular incisors of 56 Cavia cobaya were extracted and divided into four groups subjected to different socket preservation treatments. The first group treated with polyethylene glycol, the second group with DFDBBX, the third group with Moringa leaf extract, and the fourth group with a combination of DFDBBX and Moringa leaf extract. The C. cobaya were examined on days 7 and 30, after which the specimens were sacrificed and examined using an immunohistochemical technique. The resulting data were then analyzed using one-way ANOVA and Tukey's honestly significant difference tests. RESULTS: There was a significant difference in TGF-ß1 and osteocalcin expressions between the groups (P < 0.05). The highest mean amount of TGF-ß1 and osteocalcin was found in the fourth group on both days 7 and 30. CONCLUSIONS: The combination of Moringa leaf extract and DFDBBX can effectively generate TGF-ß1 and osteocalcin expressions during the preservation of tooth extraction sockets.