Basic Fibroblast Growth Factor Stimulates the Proliferation of Bone Marrow Mesenchymal Stem Cells in Giant Panda (Ailuropoda melanoleuca)

Multilayer Gelatin-Supported BMP-9 Coating Promotes Osteointegration and Neo-Bone Formation at the n-CDHA/PAA Composite Biomaterial-Bone Interface

BACKGROUND

The development of biomaterials capable of accelerating bone wound repair is a critical focus in bone tissue engineering. This study aims to evaluate the osteointegration and bone regeneration potential of a novel multilayer gelatin-supported Bone Morphogenetic Protein 9 (BMP-9) coated nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA) composite biomaterials, focusing on the material-bone interface, and putting forward a new direction for the research on the interface between the coating material and bone.

METHODS

The BMP-9 recombinant adenovirus (Adenovirus (Ad)-BMP-9/Bone Marrow Mesenchymal Stem Cells (BMSc)) was produced by transfecting BMSc and supported using gelatin (Ad-BMP-9/BMSc/Gelatin (GT). Multilayer Ad-BMP-9/BMSc/GT coated nano-calcium deficient hydroxyapatite/polyamino acid (n-CDHA/PAA) composite biomaterials were then prepared and co-cultured with MG63 cells for 10 days, with biocompatibility assessed through microscopy, Cell Counting Kit-8 (CCK-8), and alkaline phosphatase (ALP) assays. Subsequently, multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws were fabricated, and the adhesion of the coating to the substrate was observed using scanning electron microscopy (SEM). In vivo studies were conducted using a New Zealand White rabbit intercondylar femoral fracture model. The experimental group was fixed with screws featuring multilayer Ad-BMP-9/BMSc/GT coatings, while the control groups used medical metal screws and n-CDHA/PAA composite biomaterial screws. Fracture healing was monitored at 1, 4, 12, and 24 weeks, respectively, using X-ray observation, Micro-CT imaging, and SEM. Integration at the material-bone interface and the condition of neo-tissue were assessed through these imaging techniques.

RESULTS

The Ad-BMP-9/GT coating significantly enhanced MG63 cell adhesion, proliferation, and differentiation, while increasing BMP-9 expression in vitro. In vivo studies using a rabbit femoral fracture model confirmed the biocompatibility and osteointegration potential of the multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws. Compared to control groups (medical metal screws and n-CDHA/PAA composite biomaterial screws), this material demonstrated faster fracture healing, stronger osteointegration, and facilitated new bone tissue formation with increased calcium deposition at the material-bone interface.

CONCLUSION

The multilayer GT-supported BMP-9 coated n-CDHA/PAA composite biomaterials have demonstrated favorable osteogenic cell interface performance, both in vitro and in vivo. This study provides a foundation for developing innovative bone repair materials, holding promise for significant advancements in clinical applications.

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

Stimulating factors for regulation of osteogenic and chondrogenic differentiation of mesenchymal stem cells

Mesenchymal stem cells (MSCs), distributed in many tissues in the human body, are multipotent cells capable of differentiating in specific directions. It is usually considered that the differentiation process of MSCs depends on specialized external stimulating factors, including cell signaling pathways, cytokines, and other physical stimuli. Recent findings have revealed other underrated roles in the differentiation process of MSCs, such as material morphology and exosomes. Although relevant achievements have substantially advanced the applicability of MSCs, some of these regulatory mechanisms still need to be better understood. Moreover, limitations such as long-term survival in vivo hinder the clinical application of MSCs therapy. This review article summarizes current knowledge regarding the differentiation patterns of MSCs under specific stimulating factors.

Effects and mechanisms of basic fibroblast growth factor on the proliferation and regenerative profiles of cryopreserved dental pulp stem cells

OBJECTIVES

Various factors could interfere the biological performance of DPSCs during post-thawed process. Yet, little has been known about optimization of the recovery medium for DPSCs. Thus, our study aimed to explore the effects of adding recombinant bFGF on DPSCs after 3-month cryopreservation as well as the underlying mechanisms.

MATERIALS AND METHODS

DPSCs were extracted from impacted third molars and purified by MACS. The properties of CD146⁺ DPSCs (P3) were identified by CCK-8 and flow cytometry. After cryopreservation for 3 months, recovered DPSCs (P4) were immediately supplied with a series of bFGF and analysed cellular proliferation by CCK-8. Then, the optimal dosage of bFGF was determined to further identify apoptosis and TRPC1 channel through Western blot. The succeeding passage (P5) from bFGF pre-treated DPSCs was cultivated in bFGF-free culture medium, cellular proliferation and stemness were verified, and pluripotency was analysed by neurogenic, osteogenic and adipogenic differentiation.

RESULTS

It is found that adding 20 ng/mL bFGF in culture medium could significantly promote the proliferation of freshly thawed DPSCs (P4) through suppressing apoptosis, activating ERK pathway and up-regulating TRPC1. Such proliferative superiority could be inherited to the succeeding passage (P5) from bFGF pre-stimulated DPSCs, meanwhile, stemness and pluripotency have not been compromised.

CONCLUSIONS

This study illustrated a safe and feasible cell culture technique to rapidly amplify post-thawed DPSCs with robust regenerative potency, which brightening the future of stem cells banking and tissue engineering.

Basic fibroblast growth factor enhances proliferation and hepatocyte growth factor expression of feline mesenchymal stem cells

Introduction

The objective of this study is to evaluate the effect of basic fibroblast growth factor (bFGF) on the proliferation and secretion activity of feline adipose-derived mesenchymal stem cells (MSC).

Methods

Feline MSC isolated from the subcutaneous adipose tissue of cats were cultured with or without bFGF.

Results

The bFGF addition enhanced the proliferation of feline MSC to a significant great extent compared with that without bFGF, although the cell proliferation tended to increase with the bFGF concentration. In addition, adipogenic and osteogenic staining assay demonstrated that the bFGF addition allowed MSC to maintain the differentiation ability even after the proliferation. Moreover, no change in the surface markers of MSC was observed between the cultures with or without bFGF. A quantitative RT-PCR assay revealed that the HGF and TSG-6 expression significantly increased by the bFGF addition. The highest mRNA expression of MMP-2 was observed for cells cultured in 1000 ng/ml bFGF concentration.

Conclusions

The culture with bFGF is a promising way to enhance the proliferation, and HGF secretion ability of MSC as well as maintain their differentiation ability and immunophenotype nature.

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Feline adipose-derived mesenchymal stem cells (MSC) was cultured with or without the basic fibroblast growth factor (bFGF).

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The bFGF enhanced the proliferation and increased the mRNA expression of HGF, TSG-6, and MMP-2.

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The bFGF addition was not influenced to the differentiation ability and cell surface marker of MSC.

Basic fibroblast growth factor promotes human dental pulp stem cells cultured in 3D porous chitosan scaffolds to neural differentiation

AIM/PURPOSE

Dental pulp stem cells (DPSCs) were widely used as seed cells in the field of tissue engineering and regenerative medicine, including spinal cord injury (SCI) repair and other neuronal degenerative diseases, due to their easy isolation, multiple differentiation potential, low immunogenicity and low rates of rejection during transplantation. Various studies have shown that bFGF can enhance peripheral nerve regeneration after injury, and phospho-ERK (p-ERK) activation as a major mediator may be involved in this process. Previous studies also have proved that a suitable biomaterial scaffold can carry and transport the therapeutic cells effectively to the recipient area. It has showed in our earlier experiments that 3D porous chitosan scaffolds exhibited a suitable circumstance for survival and neural differentiation of DPSCs in vitro. The purpose of the study was to evaluate the influence of chitosan scaffolds and bFGF on differentiation of DPSCs.

MATERIALS AND METHODS

In current study, DPSCs were cultured in chitosan scaffolds and treated with neural differentiation medium for 7 days. The neural genes and protein markers were analyzed by western blot and immunofluorescence. Meanwhile, the relevant signaling pathway involved in this process was also tested.

RESULTS

Our study revealed that the viability of DPSCs was not influenced by co-culture with the chitosan scaffolds as well as bFGF. Compared with the control and DPSC/chitosan-scaffold groups, the levels of GFAP, S100β and β-tubulin III significantly increased in the DPSC/chitosan-scaffold+bFGF group.

CONCLUSION

Chitosan scaffolds were non-cytotoxic to the survival of DPSCs, and chitosan scaffolds combined with bFGF facilitated the neural differentiation of DPSCs. The transplantation of DPSCs/chitosan-scaffold+bFGF might be a secure and effective method of treating SCI and other neuronal diseases.

RA promotes proliferation of primordial germ cell-like cells differentiated from porcine skin-derived stem cells

Previous studies have shown that primordial germ cell-like cells (PGCLCs) can be obtained from human, porcine and mouse skin-derived stem cells (SDSCs). In this paper, we found retinoic acid (RA), the active derivative of vitamin A, accelerated the growth of porcine primordial germ cells (pPGCs) and porcine PGCLCs (pPGCLCs) which were derived from porcine SDSCs (pSDSCs). Moreover, flow cytometry results revealed that the proliferation promoting effect of RA was attenuated by U0126, a specific inhibitor of extracellular signal-regulated kinase (ERK). Western blot analysis showed the protein level of ERK, phosphorylated ERK, cyclin D1 (CCND1), and cyclin-dependent kinase 2 (CDK2) increased after stimulation with RA, and this effect could also be abolished by U0126. Our data revealed that ablation of ERK expression by U0126 should significantly decrease proliferation of pPGCLCS. This reduction was because CCND1 and CDK2 proteins level decrease and subsequently the pPGCLCs were arrested in the G0/G1 phase. In addition, we also confirmed RA indeed promoted the proliferation of pPGCs isolated from porcine fetal genital ridges in vitro. Furthermore, our data indicated that DNA methylation pattern were changed in pPGCLCs and this pattern were more similar to pPGCs.

Vascularization converts the lineage fate of bone mesenchymal stem cells to endothelial cells in tissue-engineered bone grafts by modulating FGF2-RhoA/ROCK signaling

The prevascularization of tissue-engineered bone grafts (TEBGs) has been shown to accelerate capillary vessel ingrowth in bone defect remodeling and to enhance new bone formation. However, the exact mechanisms behind this positive effect remain unknown. Here, we report that basic fibroblast growth factor (FGF2)-Ras homolog gene family member A (RhoA)/Rho-associated protein kinase (ROCK) signaling functions as a molecular switch to regulate the lineage fate of bone mesenchymal stem cells (BMSCs) and that prevascularization promotes the cell fate switch, which contributes to increased bone regeneration with the use of prevascularized TEBGs compared with control TEBGs. Prevascularized TEBGs enhanced the in vivo endothelial differentiation of BMSCs by inhibiting RhoA/ROCK signaling. In vitro data more clearly showed that BMSCs differentiated into von Willebrand factor (vWF)-positive endothelial cells, and FGF2-induced inhibition of RhoA/ROCK signaling played a key role. Our novel findings uncovered a new mechanism that stimulates the increased vascularization of engineered bone and enhanced regeneration by promoting the endothelial differentiation of BMSCs implanted in TEBGs. These results offer a new molecular target to regulate TEBG-induced bone regeneration.

Basic Fibroblast Growth Factor Inhibits Apoptosis and Promotes Proliferation of Adipose-Derived Mesenchymal Stromal Cells Isolated from Patients with Type 2 Diabetes by Reducing Cellular Oxidative Stress

Type 2 diabetes (T2D) is a chronic metabolic disorder affecting increasing number of people in developed countries. Therefore new strategies for treatment of T2D and its complications are of special interest. Nowadays, cellular therapies involving mesenchymal stromal cells that reside in adipose tissue (ASCs) constitute a promising approach; however, there are still many obstacles concerning safety and effectiveness that need to be overcome before ASCs could be engaged for the treatment of diabetes mellitus. One of the challenges is preventing ASCs from deterioration caused by elevated oxidative stress present in diabetes milieu. In the current study we investigated the effect of basic fibroblast growth factor (bFGF) treatment on ASCs isolated from patients with diagnosed T2D. We demonstrate here that cell exposition to bFGF in 5 and 10 ng/mL dosages results in improved morphology, increased proliferative activity, reduced cellular senescence and apoptosis, and decreased oxidative stress, indicating recovery of ASCs' function impaired by T2D. Therefore our results provide a support for bFGF as a potential therapeutic agent for improving stem cell-based approaches for the treatment of diabetes mellitus and its complications.

External factors influencing mesenchymal stem cell fate in vitro

Mesenchymal stem cells (MSCs) have extensive potentials, which make them attractive candidates for the developmental biology, drug discovery and regenerative medicine. However, the use of MSCs is limited by their scarceness in tissues and in culture conditions. They also exhibit various degrees of potency which subsequently influencing their applications. Nowadays, questions remain about how self-renewal and differentiation of MSCs can be controlled in vitro and in vivo, how they will behave and migrate to the right place and how they modulate the immune system. Therefore, identification of factors and culture conditions to affect the fate and function of MSCs may be effective to enhance their applications in clinical situations. Studies have indicated that the fate of MSCs in culture is influenced by various external factors, including the specific cell source, donor age, plating density, passage number and plastic surface quality. Some other factors such as cell culture media and their supplementary factors, O₂ concentration, mechano-/electro-stimuli and three-dimensional scaffolds are also shown to be influential. This review addresses the current state of MSC research for describing and discussing the findings about external factors that influence the fate and function of MSCs. Additionally, the new discoveries and suggestions regarding their molecular mechanisms will be explained.