Ginkgo biloba extract promotes osteogenic differentiation of human bone marrow mesenchymal stem cells in a pathway involving Wnt/β-catenin signaling

Optimizing orthobiologic therapies with exercise, diet, and supplements

Orthobiologic injections including platelet-rich plasma (PRP) and cell-based injections are becoming increasingly popular. Evidence suggests that these therapies can be effective in certain situations. The efficacy of these injections may be more dependent on the quality of the injectate, which given their autologous nature, may be dependent on lifestyle choices like exercise, diet, and supplements. The literature describing PRP injections shows that the number and activity of platelets can improve their efficacy. A multitude of lifestyle modifications can affect those factors. Exercise intensity appears to increase platelet count and increases adhesion as well as release of growth factors. Low inflammatory diets increase platelet counts and activity overall. Stress, some supplements, high cholesterol, or processed sugar diets can increase inflammation and potentially decrease platelet counts as well as quality of PRP injectate. Similarly, cell-based therapies can be affected by mesenchymal stromal cell (MSC) number and quality. Cell-based therapy is based upon limiting cellular senescence and increasing replication and differentiation. Exercise may limit senescence and improve replication and differentiation of these cell-based therapies, especially in older adult populations. There are a multitude of supplements that may potentiate these types of injections and patients should discuss the potential benefits and concerns when starting a supplement regimen. Certain foods as well as changes in oxygenation may limit cellular senescence and lower calorie intake may affect MSC viability and function as well. Overall, the current state of literature describes biologic plausibility of how exercise, diet and supplements might affect orthobiologic injection efficacy. Further translational research needs to be completed to describe the effect size and improve recommendations for clinical implementation.

Targeting Wnt signaling pathway with small-molecule therapeutics for treating osteoporosis

Small molecules are emerging as potential candidates for treating osteoporosis by activating canonical Wnt signaling. These candidates work either by inhibiting DKK-1, sclerostin, SFRP-1, NOTUM, and S1P lyase or by preventing β-catenin degradation through inhibition of GSK-3β, or by targeting Dvl-CXXC5 and axin/β-catenin interactions. While many of these anti-osteoporotic small molecules are in preclinical development, the paucity of FDA-approved small molecules, or promising candidates, that have progressed to clinical trials for treating bone disorders through this mechanism poses a challenge. Despite advancements in computer-aided drug design, it is rarely employed for designing Wnt signaling activators to treat osteoporosis, and high-throughput screen (HTS) remains the primary method for discovering initial hits. Acknowledging the promising therapeutic potential of these compounds in addressing bone diseases, this review underscores the need for further mechanistic elucidation to enhance our understanding of their applications. Additionally, caution must be exercised in the design of small molecule-based Wnt activators due to their association with oncological risks.

(aS)-Glucosciadopitysin, a New Biflavonoid Glycoside from the Leaves of Ginkgo biloba and Osteogenic Activity of Bioflavonoids

The leaves of Ginkgo biloba have been used in treating freckles and effectively reducing cough and sputum in folk medicines. Recently, investigations into the correlation between ginkgo leaves and the proliferative activity of osteogenic differentiation have been conducted. However, bioactive compounds that enhance osteogenesis or exhibit osteoporosis prevention from G. biloba have not been fully identified. Phytochemical investigation of the MeOH extract of G. biloba leaves led to the isolation and identification of a new biflavonoid glycoside, (aS)-glucosciadopitysin (1), along with five flavonoids (2-6), through LC/MS-guided isolation approach. The structure of the new compound 1 was elucidated by the spectroscopic methods, including 1D and 2D NMR analysis, as well as HR-ESIMS. The absolute configuration of sugar moiety was established through acid hydrolysis, followed by chemical derivatization reaction and the axial chirality arising from the biaryl system with substituents was determined by electronic circular dichroism (ECD) calculations. The isolated flavonoids (1-6) were tested for their effects on mesenchymal stem cell (MSC) differentiation at 20 μM using Oil Red O and alkaline phosphatase (ALP) staining. Ginkgetin (2) was further evaluated for osteogenic activity on C3H10T1/2 cells at concentrations of 1, 2.5, 5, and 10 μM for 10 days. ALP staining and RT-PCR assessed the gene expression of osteogenic markers ALP and osteopontin (OPN). Ginkgetin (2) demonstrated the strongest osteogenic activity, significantly increasing the expression of ALP (12.5-fold) and OPN (4.0-fold) at 10 μM, comparable to the positive control, oryzativol A. Ginkgetin (2) shows potential as a therapeutic agent for osteopenia by promoting osteogenesis in MSCs, suggesting its promising role in treating osteoporosis.

The molecular mechanisms of ginkgo (Ginkgo biloba) activity in signaling pathways: A comprehensive review

BACKGROUND

One of the most unique plants that have ever grown on the planet is Ginkgo biloba L., a member of the Ginkgoaceae family with no close living relatives. The existence of several differently structured components of G. biloba has increased the chemical variety of herbal therapy. Numerous studies that investigated the biochemical characteristics of G. biloba suggest this plant as a potential treatment for many illnesses.

PURPOSE

Review the molecular mechanisms involved in the signaling pathways of G. biloba activity in varied circumstances and its potential as a novel treatment for various illnesses.

METHODS

Studies focusing on the molecular processes and signaling pathways of compounds and extracts of G. biloba were found and summarized using the proper keywords and operators from Google Scholar, PubMed, Web of Science, and Scopus without time restrictions.

RESULTS

G. biloba exerts its effects through its anti-inflammatory, anti-apoptotic, anti-cancer, neuroprotective, cardioprotective, hepatoprotective, antiviral, antibacterial, pulmoprotective, renoprotective, anti-osteoporosis, anti-melanogenic, retinoprotective, otoprotective, adipogenic, and anti-adipogenic properties. The most important mechanisms involved in these actions are altering the elevation of ROS formation, inhibiting NADPH oxidases activation, altering the expression of antioxidant enzymes, downregulating MAPKs (p38 MAPK and ERK, and JNK) and AP-1, increasing cAMP, inactivating Stat5, activating the AMPK signaling pathway, affecting Stat3/JAK2, NF-κB, Nrf-2, mTOR, HGF/c-Met, Wnt/β-catenin and BMP signaling pathways, and changing the mitochondrial transmembrane potential, the Bax/Bcl-2 ratio, the release of Cyc from mitochondria to cytosol, the protein cleavage of caspases 3, 7, 8, 9, and 12, poly (ADP-ribose) polymerase, and MMPs levels.

CONCLUSIONS

G. biloba and its components have gained attention in recent years for their therapeutic benefits, such as their anti-inflammatory, antioxidant, anti-apoptotic, and apoptotic effects. By understanding their molecular mechanisms and signaling pathways, potential novel medicines might be developed in response to the rising public desire for new therapies.

The potential of plant extracts in cell therapy

Cell therapy is the frontier technology of biotechnology innovation and the most promising method for the treatment of refractory diseases such as tumours. However, cell therapy has disadvantages, such as toxicity and poor therapeutic effects. Plant extracts are natural, widely available, and contain active small molecule ingredients that are widely used in the treatment of various diseases. By studying the effect of plant extracts on cell therapy, active plant extracts that have positive significance in cell therapy can be discovered, and certain contributions to solving the current problems of attenuation and adjuvant therapy in cell therapy can be made. Therefore, this article reviews the currently reported effects of plant extracts in stem cell therapy and immune cell therapy, especially the effects of plant extracts on the proliferation and differentiation of mesenchymal stem cells and nerve stem cells and the potential role of plant extracts in chimeric antigen receptor T-cell immunotherapy (CAR-T) and T-cell receptor modified T-cell immunotherapy (TCR-T), in the hope of encouraging further research and clinical application of plant extracts in cell therapy.

Trans-differentiation of mouse mesenchymal stem cells into pancreatic β-like cells by a traditional anti-diabetic medicinal herb Medicago sativa L

BACKGROUND AND AIM

Medicago sativa L. is a medicinal herb first cultivated in ancient Iran. Traditionally, it has been utilized for the treatment of several disorders. The plant has been in the human diet for at least 1500 years. Although the hypoglycaemic and anti-diabetic effects of the plant have been approved in traditional medicine, further investigations are needed to support the rational use of M. sativa by humans. This project aimed to evaluate the trans-differentiation potential of bone marrow mesenchymal stem cells (MSCs) to pancreatic β-like cells (insulin-producing cells; IPCs) under the influence of M. sativa extract.

EXPERIMENTAL PROCEDURE

Bone marrow MSCs isolated, characterized, and then treated by flower or leaf extract of M. sativa. Beta-cell characteristics of the differentiated cells were evaluated by several techniques, including specific staining, QPCR, immunofluorescence, and ELISA.

RESULTS

The results showed that the differentiated cells were able to express some specific pancreatic genes (PDX-1, insulin1, and insulin2) and proteins (insulin receptor beta, insulin, proinsulin, and C peptide). Furthermore, ELISA analysis indicated the ability of these cells in the production and secretion of insulin, after exposure to glucose.

CONCLUSION

Overall, both the flower and leaf extract of M. sativa had the potential of differentiation induction of MSCs into IPCs with the characteristics of pancreatic β-like cells. Therefore, M. sativa, as an herbal drug, may be beneficial for the treatment of diseases including diabetes.

Therapeutic Potential of Skin Stem Cells and Cells of Skin Origin: Effects of Botanical Drugs Derived from Traditional Medicine

Skin, the largest organ of the body, plays a vital role in protecting inner organs. Skin stem cells (SSCs) comprise a group of cells responsible for multiplication and replacement of damaged and non-functional skin cells; thereby help maintain homeostasis of skin functions. SSCs and differentiated cells of the skin such as melanocytes and keratinocytes, have a plethora of applications in regenerative medicine. However, as SSCs reside in small populations in specific niches in the skin, use of external stimulants for cell proliferation in vitro and in vivo is vital. Synthetic and recombinant stimulants though available, pose many challenges due to their exorbitant prices, toxicity issues and side effects. Alternatively, time tested traditional medicine preparations such as polyherbal formulations are widely tested as effective natural stimulants, to mainly stimulate proliferation, and melanogenesis/prevention of melanogenesis of both SSCs and cells of skin origin. Complex, multiple targets, synergistic bioactivities of the phytochemical constituents of herbal preparations amply justify these as natural stimulants. The use of these formulations in clinical applications such as in skin regeneration for burn wounds, wound healing acceleration, enhancement or decrease of melanin pigmentations will be in great demand. Although much multidisciplinary research is being conducted on the use of herbal formulas as stem cell stimulants, very few related clinical trials are yet registered with the NIH clinical trial registry. Therefore, identification/ discovery, in depth investigations culminating in clinical trials, as well as standardization and commercialization of such natural stimulants must be promoted, ensuring the sustainable use of medicinal plants.

Hormesis and bone marrow stem cells: Enhancing cell proliferation, differentiation and resilience to inflammatory stress

This paper identifies and provides the first detailed assessment of hormetic dose responses by bone marrow stem cells (BMSCs) from a broad range of animal models and humans with particular emphasis on cell renewal (proliferation), cell differentiation and enhancing resilience to inflammatory stress. Such hormetic dose responses are commonly reported, being induced by a broad range of chemicals, including pharmaceuticals (e.g., caffeine, dexamethasone, nicotine), dietary supplements (e.g., curcumin, Ginkgo biloba, green tea extracts. resveratrol, sulforaphane), endogenous agents (e.g., hydrogen sulfide, interleukin 10), environmental contaminants (e.g., arsenic, PFOS) and physical stressor agents (e.g., EMF, shockwaves). Hormetic dose responses reported here for BMSCs are similar to those induced with other stem cell types [e.g., adipose-derived stem cells (ADSCs), dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), neuro stem cells (NSCs), embryonic stem cells (ESCs)], indicating a substantial degree of generality for hormetic responses in stem cells. The paper assesses both the underlying mechanistic foundations of BMSC hormetic responses and their potential therapeutic implications.

Enamel matrix derivative (EMD) enhances the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs)

To investigate the EMD's capacity in BMSCs osteogenic differentiation. In vivo and in vitro, BMSCs were treated with EMD, scanning electron microscopy, and Alizarin Red staining were used to detect the changes in the osteogenic ability of BMSCs, and the proliferation ability of BMSCs was evaluated by CCK8. In addition, by adding xav939, a typical inhibitor of Wnt/β-catenin signaling pathway, the regulatory function of Wnt/β-catenin signaling was clarified. The results showed that EMD promote cell proliferation and 25 μg/ml EMD had the most significant effect. Cells inducing osteogenesis for 2 and 3 even 4 weeks, the cell staining is deeper in EMD treated group than that of the control (P < 0.05) by alizarin Red staining, suggesting more mineralization of BMSCs. In vivo implanting the titanium plate wrapped with 25 μg/ml EMD treated-BMSC film into nude mice for 8 weeks, more nodules were formed on the surface of the titanium plate than that the control (P < 0.05). HE showed that there is a little blue-violet immature bone-like tissue block. Besides, the expression of RUNX Family Transcription Factor 2 (Runx2), Osterix, Osteocalcin (OCN), collagen I (COLI), alkaline phosphatase (ALP) and β-catenin were inhibited in xav939 group (P < 0.05); Inversely, all were activated in EMD group (P < 0.05). In conclusion, EMD promoted the proliferation and osteogenic differentiation of BMSCs. EMD's function on BMSCs might be associated with the Wnt/β-catenin signaling pathway.

Wnt signaling activation: targets and therapeutic opportunities for stem cell therapy and regenerative medicine

Wnt proteins are secreted morphogens that play critical roles in embryonic development, stem cell proliferation, self-renewal, tissue regeneration and remodeling in adults. While aberrant Wnt signaling contributes to diseases such as cancer, activation of Wnt/β-catenin signaling is a target of interest in stem cell therapy and regenerative medicine. Recent high throughput screenings from chemical and biological libraries, combined with improved gene expression reporter assays of Wnt/β-catenin activation together with rational drug design, led to the development of a myriad of Wnt activators, with different mechanisms of actions. Among them, Wnt mimics, antibodies targeting Wnt inhibitors, glycogen-synthase-3β inhibitors, and indirubins and other natural product derivatives are emerging modalities to treat bone, neurodegenerative, eye, and metabolic disorders, as well as prevent ageing. Nevertheless, the creation of Wnt-based therapies has been hampered by challenges in developing potent and selective Wnt activators without off-target effects, such as oncogenesis. On the other hand, to avoid these risks, their use to promote ex vivo expansion during tissue engineering is a promising application.

Effect of Eucomis autumnalis on the Osteogenic Differentiation of Adipose Derived Stem Cells

Eucomis autumnalis subsp. autumnalis (Mill.) Chitt. (EASA) is a commonly used medicinal plant for the treatment of fractures, osteoarthritis, back pain, and wound healing in Southern Africa. In this study, the effects of water and acetone extracts of EASA on the viability, osteogenic differentiation, and mineralization of human adipose derived stem cells (hADSCs) were investigated in vitro. The results showed that both water and acetone extracts of EASA increased cell viability at concentrations between 10 to 50 µg/mL on day 7 and 14 of treatment. Osteogenic differentiation and mineralization of hADSCs was optimal at 5 μg/mL for the water extract and at 5 to 10 μg/ml for the acetone extract. A 5 µg/ml acetone extract up-regulated the expression of the ALP, Runx2, Col1a1, and osteocalcin genes. In addition, EASA up-regulated β-catenin, cyclin D1 and osteoprotegerin genes. The results suggest that EASA may likely up-regulate the expression of β-catenin, which subsequently up-regulates the osteogenic marker genes through Runx2. On the other hand, EASA also up-regulates cyclin D1 supporting the growth of precursor cells. Additionally, EASA upregulated the expression of osteoprotegerin (OPG) suggesting that it may inhibit bone resorption. The results of this study support the traditional use of the plant in bone healing.

Comparing the effects of Elaegnus Angustifolia, Hypericum Perforatum and Psidium Guajava extracts on metabolic activity of dental pulp-derived mesenchymal stem cells

Dental pulp derived-mesenchymal stem cells (DP-MSCs) is considered a suitable are candidate for tissue engineering techniques and osseous reconstruction. Based on the hypothesis that Hypericum perforatum, Elaeagnus Angustifolia and Psidium guajava extracts can be used in cell-based bone tissue engineering due to meagre cytotoxicity response in the cell culture medium, their effects on the viability and metabolic activity of DP-MSCs were investigated and compared with each extract. DP-MSCs were extracted from human dental pulp, characterized by flow cytometry, and differentiated into Osteogenic and adipogenic lineages which were then cultured in different concentrations of E. Angustifolia, H. perforatum and P. guajava extracts at different time intervals followed by MTT assay evaluation. The dental pulp mesenchymal stem cells were evaluated for their plastic adherence ability, fibroblast-like and spindle morphology. According to flow cytometry data, isolated cells from DP-MSCs expressed MSCs markers. A comparison of herbal extracts' concentrations revealed that 500 μg/ml was toxic to dental pulp stem cells, a guide to the toxic dose for DP-MSCs. The P.guajava bore low toxicity and increased dental pulp stem cell viability in comparison to the other two herbal extracts. The hydro-alcoholic extracts of E. Angustifolia, H. perforatum, and P. guajava were efficient in DP-MSCs viability, and therefore were concluded to be useful in maintaining structural and functional cell viability. It was also concluded that the co-culture of stem cells with herbal elements could stimulate endogenous factors to enhance the proliferation and viability of MSCs.

Meta-analysis of Ginkgo biloba Preparation for the Treatment of Alzheimer's Disease

OBJECTIVE

The objective of this study was to investigate the efficacy and safety of Ginkgo biloba preparation for the treatment of Alzheimer disease (AD).

METHODS

Both English (PubMed, Embase, Cochrane Library databases, and the Cochrane Controlled Trials Register) and Chinese (WanFang, Chinese Biomedical, CNKI, and VIP databases) databases were systematically and independently searched by 2 authors from their inception until July 3, 2019. All relevant studies included AD patients who were treated with Ginkgo biloba. The efficacy and safety of the medicine were used as the main measurement index.

RESULTS

Seven studies (N = 939) were identified and analyzed. When compared with placebo, Ginkgo biloba showed exact validity in cognitive function and global clinical assessment (cognitive function section: risk ratio = 1.98, 95% confidence interval = 1.52-2.59, Z = 5.12, P < 0.001; according to Clinical Global Impression Change: odds ratio = 3.119, 95% confidence interval = 2.206-4.410, Z = 6.44, P < 0.001). Adverse events were mild.

CONCLUSIONS

Ginkgo biloba preparation has reliable efficacy of cognitive function and global clinical assessment and safety in the treatment of AD.

Hormesis and Ginkgo biloba (GB): Numerous biological effects of GB are mediated via hormesis

Ginkgo biloba (GB) extracts have been shown to commonly induce biphasic dose responses in a range of cell types and endpoints (e.g., cochlea neural stem cells, cell viability, cell proliferation). The magnitude and width of the low dose stimulation of these biphasic dose responses are similar to those reported for hormetic dose responses. These hormetic dose responses occur within direct stimulatory responses as well as in preconditioning experimental protocols, displaying acquired resistance within an adaptive homeodynamic and temporal framework and repeated measurement protocols. The demonstrated GB dose responses further reflect the general occurrence of hormetic dose responses that consistently appear to be independent of the biological model, endpoint, inducing agent, and/or mechanism. These findings have important implications for consideration(s) of study designs involving dose selection, dose spacing, sample size, and statistical power. This illustrates and strengthens the need to characterize the low dose stimulatory response range and optimal dose in order to explore potential public health and clinical applications of plant-derived agents, such as GB.

Osteogenic differentiation potential of human bone marrow-derived mesenchymal stem cells enhanced by bacoside-A

Stem cell therapy is growing rapidly to treat numerous diseases including bone-associated diseases. Mesenchymal stem cells (MSCs) are most commonly preferred to treat bone diseases because it possesses high osteogenic potency. Though, to obtain maximum osteogenic efficiency of MSCs is challenging. Therefore, this study was planned to evaluate the osteogenic efficiency of human bone marrow derived mesenchymal stem cells (hBMSCs) by bacoside-A. This study was investigated the activity of alkaline phosphatase (ALP) and expressions of the genes specific to osteogenic regulation mainly runt-related transcription factor 2 (Runx2), osterix (Osx), osteocalcin (OCN) and collagen type Iα1 (Col I α1) in hBMSCs cultured under osteogenic conditions at different concentrations of bacoside-A for 14 days. The results of this study depicted significant upregulation in the activity of ALP and expressions of osteogenic regulator genes in bacoside-A treated cells when compared with control cells. Besides, expressions of glycogen synthase kinase-3β (GSK-3β) and Wnt/β-catenin were evaluated; these expressions were also significantly increased in bacoside-A treated cells when compared with control cells. This result provides a further supporting evidence of bacoside-A role on osteogenesis in hBMSCs. The present study suggest that bacoside-A will be applied to ameliorate the process of osteogenesis in hBMSCs to repair damaged bone structure during MSC-based therapy; this will be an excellent and auspicious treatment for bone-associated disorders including osteoporosis. Significance of the study Osteoporosis is a bone metabolic disorder characterized by an imbalance between the activity of osteoblastic bone formation and osteoclastic bone resorption that disrupts the bone microarchitecture. Current anti-osteoporotic drugs are inhibiting bone resorption, but they are unable to restore the bone structure due to extreme bone remodelling process and causes numerous side effects. The finding of natural bioactive compounds with osteogenic property is very essential for osteoporosis treatment. This study was reported that bacoside-A ameliorated osteogenic differentiation of hBMSCs through upregulation of osteogenic differentiation genes and Wnt/β-catenin signalling pathway. This result is indicating that bacoside-A may be useful for osteoporosis treatments.

Effects of Sapindus mukorossi Seed Oil on Proliferation, Osteogenetic/Odontogenetic Differentiation and Matrix Vesicle Secretion of Human Dental Pulp Mesenchymal Stem Cells

Stem cells have attracted great interest in the development of tissue engineering. However, the self-regeneration and multi-differentiation capabilities of stem cells are easily impaired during cell transplantation. Recent studies have demonstrated that Sapindus mukorossi (S. mukorossi) seed oil has various positive biological effects. However, it is not yet clear whether S. mukorossi seed oil can increase the growth and differentiation of dental pulp mesenchymal stem cells (DPSCs). The aim of this study is to investigate the effects of S. mukorossi seed oil on the proliferation and differentiation of DPSCs. DPSCs with and without S. mukorossi seed oil, respectively, were evaluated and compared. The viabilities of the cells were assessed by MTT tests. The osteogenetic and odontogenetic capacities of the DPSCs were tested using Alizarin red S staining and alkaline phosphatase (ALP) activity assays. In addition, real-time PCR was performed to examine the gene expression of ALP, BMP-2 and DMP-1. Finally, extracellular matrix vesicle secretion was detected via scanning electron microscopy. No significant difference was observed in the viabilities of the DPSCs with and without S. mukorossi seed oil, respectively. However, under osteogenic and odontogenic induction, S. mukorossi seed oil increased the secretion of mineralized nodules and the ALP activity of the DPSCs (p < 0.05). The ALP gene expression of the differentiation-induced DPSCs was also enhanced. Finally, a greater secretion of extracellular matrix vesicles was detected in the DPSCs following odontogenic induction complemented with S. mukorossi seed oil. Overall, the present results show that S. mukorossi seed oil promotes the osteogenic/odontogenic differentiation and matrix vesicle secretion of DPSCs.

Ilimaquinone inhibits neovascular age-related macular degeneration through modulation of Wnt/β-catenin and p53 pathways

Neovascular age-related macular degeneration (nAMD) is a common cause of irreversible vision loss in the elderly. Anti-vascular endothelial growth factor has been effective in treating pathological ocular neovascularization, but it has limitations including the need for repeated intraocular injections for the maintenance of therapeutic effects in most patients and poor or non-response to this agent in some patients. in vitro cellular studies were conducted using retinal pigment epithelial cell lines (ARPE-19 and hTERT-RPE1), human umbilical vein endothelial cells (HUVECs), and human umbilical vein smooth muscle cells (HUVSMCs). in vivo efficacy of ilimaquinone (IQ) was tested in laser-induced choroidal neovascularization mouse and rabbit models. Tissue distribution study was performed in male C57BL6/J mice. IQ, 4,9-friedodrimane-type sesquiterpenoid isolated from the marine sponge, repressed the expression of angiogenic/inflammatory factors and restored the expression of E-cadherin in retinal pigment epithelial cells by inhibiting the Wnt/β-catenin pathway. In addition, it selectively inhibited proliferation and tube formation of HUVECs by activating the p53 pathway. Topical and intraperitoneal administration of IQ significantly reduced choroidal neovascularization in rabbits and mice with laser-induced choroidal neovascularization. Notably, IQ by the oral route of exposure was highly permeable to the eyes and suppressed abnormal vascular leakage by downregulation of β-catenin and stabilization of p53 in vivo. Our findings demonstrate that IQ functions through regulation of p53 and Wnt/β-catenin pathways with conceivable advantages over existing cytokine-targeted anti-angiogenic therapies.

Small Molecule Wnt Pathway Modulators from Natural Sources: History, State of the Art and Perspectives

The Wnt signaling is one of the major pathways known to regulate embryonic development, tissue renewal and regeneration in multicellular organisms. Dysregulations of the pathway are a common cause of several types of cancer and other diseases, such as osteoporosis and rheumatoid arthritis. This makes Wnt signaling an important therapeutic target. Small molecule activators and inhibitors of signaling pathways are important biomedical tools which allow one to harness signaling processes in the organism for therapeutic purposes in affordable and specific ways. Natural products are a well known source of biologically active small molecules with therapeutic potential. In this article, we provide an up-to-date overview of existing small molecule modulators of the Wnt pathway derived from natural products. In the first part of the review, we focus on Wnt pathway activators, which can be used for regenerative therapy in various tissues such as skin, bone, cartilage and the nervous system. The second part describes inhibitors of the pathway, which are desired agents for targeted therapies against different cancers. In each part, we pay specific attention to the mechanisms of action of the natural products, to the models on which they were investigated, and to the potential of different taxa to yield bioactive molecules capable of regulating the Wnt signaling.

Ganoderal A effectively induces osteogenic differentiation of human amniotic mesenchymal stem cells via cross-talk between Wnt/β-catenin and BMP/SMAD signaling pathways

Osteogenic inducers play central roles in effective stem cell-based treatment of bone defects/losses. However, the current routine osteogenic inducer is a cocktail comprising three components that must be improved due to low induction efficiency and side effects. Therefore, there is an urgent need to develop safer and more effective osteoinducers. Herein, we demonstrated the osteogenic effect of Ganoderal A (GD-A), a tetracyclic triterpenoid compound from Ganoderma lucidum. GD-A showed no cytotoxicity toward human amniotic mesenchymal stem cells (hAMSCs) at doses of 0.001-10 μM; furthermore, 0.01 μM GD-A significantly induced the generation of osteoblast-specific markers, such as alkaline phosphatase, and calcium deposition in hAMSCs. At molecular levels, GD-A promoted the expression of multiple osteoblast differentiation markers, such as RUNX2, OSX, OPN, ALP, OCN, and COL1α1. Both Wnt/β-catenin and BMP/SMAD signaling were shown as active during hAMSC osteodifferentiation. Furthermore, specific blocking of both signals by KYA1797K and SB431542 significantly inhibited alkaline phosphatase secretion and RUNX2 and ALP expression when used alone or in combination. Meanwhile, both signals were also blocked. These findings suggest that GD-A induces hAMSC differentiation into osteoblasts through signaling cross-talk between Wnt/β-catenin and BMP/SMAD. Taken together, GD-A is a safe, effective, and novel osteoinducer and might be used for stem cell-based therapy for bone defects/losses.

In vitro differentiation induction of embryonal carcinoma stem cells into insulin-producing cells by Cichorium intybus L. leaf extract

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal herb Cichorium intybus L. (chicory) has been used traditionally for the treatment of various diseases, including diabetes. One of the promising therapeutic options to treat diabetes is replacing the degenerative pancreatic β cells by stem cell-derived IPCs (insulin-producing cells).

AIM OF THE STUDY

By the combination of cell therapy as a modern approach and traditional medicine, the current study was designed to evaluate the effects of chicory leaf extract (LE) on the differentiation potential of P19 EC cells (an embryonal carcinoma stem cell line) into IPCs.

MATERIALS AND METHODS

The plant (voucher no. 4567) were collected and deposited in the herbarium of Shahrekord University. In vitro experiments were designed to compare the effects of various concentrations of LE on the differentiation potential of P19 EC cells.

RESULTS

The differentiated cells showed morphological characteristics of pancreatic β cells. They could also synthesized and secreted insulin when exposed to glucose. Moreover, the cells expressed specific proteins and genes of mature pancreatic β cells.

CONCLUSIONS

In conclusion, LE as a natural herbal extract was efficiently able to induce the differentiation of P19 EC cells into the clusters similar to pancreatic islets with the molecular, cellular and functional characteristics of mature β cells.

Small molecules for mesenchymal stem cell fate determination

Mesenchymal stem cells (MSCs) are adult stem cells harboring self-renewal and multilineage differentiation potential that are capable of differentiating into osteoblasts, adipocytes, or chondrocytes in vitro, and regulating the bone marrow microenvironment and adipose tissue remodeling in vivo. The process of fate determination is initiated by signaling molecules that drive MSCs into a specific lineage. Impairment of MSC fate determination leads to different bone and adipose tissue-related diseases, including aging, osteoporosis, and insulin resistance. Much progress has been made in recent years in discovering small molecules and their underlying mechanisms control the cell fate of MSCs both in vitro and in vivo. In this review, we summarize recent findings in applying small molecules to the trilineage commitment of MSCs, for instance, genistein, medicarpin, and icariin for the osteogenic cell fate commitment; isorhamnetin, risedronate, and arctigenin for pro-adipogenesis; and atractylenolides and dihydroartemisinin for chondrogenic fate determination. We highlight the underlying mechanisms, including direct regulation, epigenetic modification, and post-translational modification of signaling molecules in the AMPK, MAPK, Notch, PI3K/AKT, Hedgehog signaling pathways etc. and discuss the small molecules that are currently being studied in clinical trials. The target-based manipulation of lineage-specific commitment by small molecules offers substantial insights into bone marrow microenvironment regulation, adipose tissue homeostasis, and therapeutic strategies for MSC-related diseases.

A Review on the Effect of Plant Extract on Mesenchymal Stem Cell Proliferation and Differentiation

Stem cell has immense potential in regenerative cellular therapy. Mesenchymal stem cells (MSCs) can become a potential attractive candidate for therapy due to its remarkable ability of self-renewal and differentiation into three lineages, i.e., ectoderm, mesoderm, and endoderm. Stem cell holds tremendous promises in the field of tissue regeneration and transplantation for disease treatments. Globally, medicinal plants are being used for the treatment and prevention of a variety of diseases. Phytochemicals like naringin, icariin, genistein, and resveratrol obtained from plants have been extensively used in traditional medicine for centuries. Certain bioactive compounds from plants increase the rate of tissue regeneration, differentiation, and immunomodulation. Several studies show that bioactive compounds from plants have a specific role (bioactive mediator) in regulating the rate of cell division and differentiation through complex signal pathways like BMP2, Runx2, and Wnt. The use of plant bioactive phytochemicals may also become promising in treating diseases like osteoporosis, neurodegenerative disorders, and other tissue degenerative disorders. Thus, the present review article is aimed at highlighting the roles and consequences of plant extracts on MSCs proliferation and desired lineage differentiations.

Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment

Stem cell transplantation has brought new hope for the treatment of neurological diseases. The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells. Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors, the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located. Accordingly, the optimal microenvironment for inducing stem cell differentiation is a hot topic. EGb761 is extracted from the leaves of the Ginkgo biloba tree. It is used worldwide and is becoming one of the focuses of stem cell research. Studies have shown that EGb761 can antagonize oxygen free radicals, stabilize cell membranes, promote neurogenesis and synaptogenesis, increase the level of brain-derived neurotrophic factors, and replicate the environment required during the differentiation of stem cells into nerve cells. This offers the possibility of using EGb761 to induce the differentiation of stem cells, facilitating stem cell transplantation. To provide a comprehensive reference for the future application of EGb761 in stem cell therapy, we reviewed studies investigating the influence of EGb761 on stem cells. These started with the composition and neuropharmacology of EGb761, and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.

TIMP-1 inhibits proliferation and osteogenic differentiation of hBMSCs through Wnt/β-catenin signaling

The present study aimed to evaluate the effect of tissue inhibitor of metalloproteinase-1 (TIMP-1) on the proliferation and osteogenic differentiation potential of human bone marrow-derived MSCs (hBMSCs). hBMSCs with stable TIMP-1 overexpression or TIMP-1 knockdown were generated. Osteogenic differentiation was assessed by Alizarin Red S staining, alkaline phosphatase (ALP) activity and expression of specific markers. Compared with the vehicle controls, TIMP-1 knockdown significantly promoted the growth of hBMSCs. TIMP-1 knockdown up-regulated β-catenin and cyclin D1 proteins. During osteogenic differentiation, TIMP-1 knockdown elevated the deposition of calcium nodules, ALP activity and the mRNA levels of the osteogenic markers sex determining region Y-box 9 (Sox9), CCAAT-enhancer-binding protein and peroxisome proliferator-activated receptor γ. During osteogenic differentiation, TIMP-1 knockdown significantly enhanced the up-regulation of osteocalcin proteins. Meanwhile, TIMP-1 overexpression attenuated the Wnt/activator Wnt3a-induced up-regulation cyclin D1 and Runt-related transcription factor 2 (RUNX-2) (during osteogenic differentiation) proteins, while TIMP-1 knockdown restored the inhibitor Dickkopf 1-induced inhibition effect on the expression of β-catenin, cyclin D1 and RUNX-2. TIMP-1 plays a negative regulatory role in the proliferation and osteogenesis of hBMSCs, at least partially, through Wnt/β-catenin signaling.

Plants and Their Bioactive Constituents in Mesenchymal Stem Cell-Based Periodontal Regeneration: A Novel Prospective

Periodontitis is a common chronic inflammatory disease, which causes the destruction of both the soft and mineralized tissues. However, current treatments such as bone graft materials, barrier membranes, and protein products all have difficulties in regenerating the complete periodontal tissue structure. Stem cell-based tissue engineering has now emerged as one of the most effective treatments for the patients suffering from periodontal diseases. Plants not only can be substrates for life processes, but also contain hormones or functional molecules. Numbers of preclinical studies have revealed that products from plant can be successfully applied in modulating proliferation and differentiation of human mesenchymal stem cells. Plant-derived substances can induce stem cells osteogenic differentiation, and they also possess angiogenic potency. Furthermore, in the field of tissue engineering, plant-derived compounds or plant extracts can be incorporated with biomaterials or utilized as biomaterials for cell transplantation. So it is speculated that botanical products may become a new perspective in stem cell-based periodontal regeneration. However, the lack of achieving predict clinical efficacy and quality control has been the major impediment to its extensive application. This review gives an overview of the prospect of applying different plant-derived substances in various human mesenchymal stem cells-based periodontal regeneration.

The Growth Proliferation, Apoptotic Prevention, and Differentiation Induction of the Gelatin Hydrolysates from Three Sources to Human Fetal Osteoblasts (hFOB 1.19 Cells)

Gelatins from the skin of bovine, porcine, and tilapia were hydrolyzed to three degrees of hydrolysis (DH) by alcalase, neutrase, and papain, respectively. These hydrolysates at 0.02⁻0.1 g/L promoted the growth of human fetal osteoblasts by 101.4⁻135.7%, while higher DH or using papain and tilapia gelatins resulted in higher proliferation. The hydrolysates from porcine and tilapia gelatins at 0.05 g/L prevented induced apoptosis (decreasing total apoptotic proportions from 28.4% or 35.2% to 10.3⁻17.5% or 16.0⁻23.6%), and had differentiation induction (increasing alkaline phosphatase activity by 126.9⁻246.7% in early differentiation stage, or enhancing osteocalcin production by 4.1⁻22.5% in later differentiation stage). These hydrolysates had a similar amino acid profile; however, tilapia gelatin hydrolysates by papain with DH 15.4% mostly displayed higher activity than others. Tilapia gelatin hydrolysate could up-regulate β-catenin, Wnt 3a, Wnt 10b, cyclin D1, and c-Myc expression at mRNA levels by 1.11⁻3.60 folds, but down-regulate GSK 3β expression by 0.98 fold. Of note, β-catenin in total cellular and nuclear protein was up-regulated by 1.14⁻1.16 folds but unchanged in cytoplasmic protein, Wnt 10b, cyclin D1, and c-Myc expression were up-regulated by 1.27⁻1.95 folds, whilst GSK 3β expression was down-regulated by 0.87 fold. Activation of Wnt/β-catenin pathway is suggested to mediate cell proliferation and differentiation.

The catalytic activity for ginkgolic acid biodegradation, homology modeling and molecular dynamic simulation of salicylic acid decarboxylase

The toxic ginkgolic acids are the main safety concern for the application of Ginkgo biloba. In this study, the degradation ability of salicylic acid decarboxylase (SDC) for ginkgolic acids was examined using ginkgolic acid C15:1 as a substrate. The results indicated that the content of ginkgolic acid C15:1 in Ginkgo biloba seeds was significantly decreased after 5 h treatment with SDC at 40 °Cand pH 5.5. In order to explore the structure of SDC and the interaction between SDC and substrates, homology modeling, molecular docking and molecular dynamics were performed. The results showed that SDC might also have a catalytic active center containing a Zn²⁺. Compared with the template structure of 2,6-dihydroxybenzoate decarboxylase, the residues surrounding the binding pocket, His10, Phe23 and Phe290, were replaced by Ala10, Tyr27 and Tyr301 in the homology constructed structure of SDC, respectively. These differences may significantly affect the substrates adaptability of SDC for salicylic acid derivatives.

Conserved signaling pathways underlying heterotopic ossification

Heterotopic ossification (HO), a serious disorder of extra-skeletal bone formation, occurs as a common complication of trauma or in rare genetic disorders. Many conserved signaling pathways have been implicated in HO; however, the exact underlying molecular mechanisms for many forms of HO are still unclear. The emerging picture is that dysregulation of bone morphogenetic protein (BMP) signaling plays a central role in the process, but that other conserved signaling pathways, such as Hedgehog (HH), Wnt/β-catenin and Fibroblast growth factors (FGF), are also involved, either through cross-talk with BMP signaling or through other independent mechanisms. Deep understanding of the conserved signaling pathways is necessary for the effective prevention and treatment of HO. In this review, we update and integrate recent progress in this area. Hopefully, our discussion will point to novel promising, druggable loci for further translational research and successful clinical applications.

Effects of Bambusa tulda on the proliferation of human stem cells

To date, the effects of Bambusa tulda on stem cells have not been thoroughly assessed. The present study aimed to evaluate the effects of Bambusa tulda extract on the morphology and proliferative potential of human mesenchymal stem cells derived from the gingiva. The stem cells were cultured in a growth medium in the presence of Bambusa tulda methanolic extract (BBT) at concentrations ranging from 0.001 to 1%. Evaluation of cell morphology and cellular proliferation as well as immunofluorescent assays for collagen I were performed on days 1, 3, 5 and 7. Stem cells in the control group displayed a fibroblast-like morphology, and BBT treatment did not produce any noticeable morphological changes. However, application of 1% BBT produced a significant increase in cell proliferation. BBT, particularly at the concentration of 1%, also caused a noticeable increase of collagen I expression at day 1 and day 3. Based on these findings, it was concluded that BBT exerted beneficial effects on the proliferation of mesenchymal stem cells and enhanced collagen I expression at early time points.

Du-Huo-Ji-Sheng-Tang and its active component Ligusticum chuanxiong promote osteogenic differentiation and decrease the aging process of human mesenchymal stem cells

ETHNOPHARMACOLOGICAL RELEVANCE

Postmenopausal osteoporosis is the most common bone disease worldwide. Information concerning the effects of herbal medicines on mesenchymal cell osteogenesis and senescence remains lacking.

AIM OF THIS STUDY

This study was designed to investigate the effects of Du-Huo-Ji-Sheng-Tang (DHJST), a Chinese herbal medicine and its active component Ligusticum chuanxiong on osteogenic differentiation and the aging process of human mesenchymal cells (hMSCs).

MATERIALS & METHODS

hMSCs were used as in vitro model and osteogenesis was induced by administration of either osteogenesis inducing medium (OIM) or dexamethasone-depleted OIM (DDOIM) for 1-week or 2 weeks and the results were evaluated by measuring the formation of mineralization nodules. The effects of the compound recipe DHJST and its active component L. chuanxiong on hMSCs osteogenesis-related gene expression was determined by real-time PCR that targeted bone morphogenetic protein-2 (BMP2), RUNX2, ALP, COL-1, osteopontin (OPN), and osteocalcin (OCN). Antibodies against BMP-related signaling pathway proteins, such as BMP-2, ERK, SMAD 1/5/8, and RUNX2, were also detected at the protein level by Western blotting. Finally, the cumulative growth curve and senescence of the hMSCs were evaluated in order to assess the aging process.

RESULTS

L. chuanxiong increased osteogenic activity in hMSCs and up-regulated BMP-2 and RUNX2 gene expression via the activation of SMAD 1/5/8 and ERK signaling. Furthermore DHJST also showed a trend towards promoting the same effects in the same system. In the absence of dexamethasone, DHJST did activate SMAD 1/5/8 and ERK signaling and hence increased RUNX2 protein expression in hMSCs. In addition, both DHJST and L. chuanxiong delayed the hMSCs aging process by decreasing cell senescence.

CONCLUSIONS

We concluded that DHJST and its active component L. chuanxiong are able to promote osteogenic activity and decrease hMSCs senescence as cells age.

Tenuigenin promotes the osteogenic differentiation of bone mesenchymal stem cells in vitro and in vivo

Osteoporosis, which is a systemic skeletal disease characterized by low bone mineral density and microarchitectural deterioration of bone quality, is a global and increasing public health problem. Recent studies have suggested that Tenuigenin (TEN), a class of native compounds with numerous biological activities such as anti-resorptive properties, exerts protective effects against postmenopausal bone loss. The present study aims to investigate the osteogenic effects of TEN on bone mesenchymal stem cells (BMSCs) in vitro and in vivo. Alkaline phosphatase (ALP) activity/staining, Alizarin red staining and the expression of osteogenic markers, including runt-related transcription factor 2, osterix, osteocalcin, collagen Iα1, β-catenin and glycogen synthase kinase-3β were investigated in primary femoral BMSCs from C57/BL6 mice cultured under osteogenic conditions for 2 weeks to examine the effects of TEN. An ovariectomized (OVX) mouse model was used to investigate the effect of TEN treatment for 3 months in vivo. We found that ALP activity, mineralized nodules and the expression of osteogenic markers were increased and WNT/β-catenin signaling was enhanced in vitro and in vivo. Bone parameters, including trabecular thickness, trabecular number and bone mineral density were higher in the OVX+TEN group than in control OVX mice. Our results suggest the therapeutic potential of TEN for the treatment of patients with postmenopausal osteoporosis.

Pivotal Cytoprotective Mediators and Promising Therapeutic Strategies for Endothelial Progenitor Cell-Based Cardiovascular Regeneration

Cardiovascular diseases (CVDs), including atherosclerosis, stroke, and myocardial infarction, is a major cause of death worldwide. In aspects of cell therapy against CVD, it is generally accepted that endothelial progenitor cells (EPCs) are potent neovascular modulators in ischemic tissues. In response to ischemic injury signals, EPCs located in a bone marrow niche migrate to injury sites and form new vessels by secreting various vasculogenic factors including VEGF, SDF-1, and FGF, as well as by directly differentiating into endothelial cells. Nonetheless, in ischemic tissues, most of engrafted EPCs do not survive under harsh ischemic conditions and nutrient depletion. Therefore, an understanding of diverse EPC-related cytoprotective mediators underlying EPC homeostasis in ischemic tissues may help to overcome current obstacles for EPC-mediated cell therapy for CVDs. Additionally, to enhance EPC's functional capacity at ischemic sites, multiple strategies for cell survival should be considered, that is, preconditioning of EPCs with function-targeting drugs including natural compounds and hormones, virus mediated genetic modification, combined therapy with other stem/progenitor cells, and conglomeration with biomaterials. In this review, we discuss multiple cytoprotective mediators of EPC-based cardiovascular repair and propose promising therapeutic strategies for the treatment of CVDs.

Stimulatory effects of the degradation products from Mg-Ca-Sr alloy on the osteogenesis through regulating ERK signaling pathway

The influence of Mg-1Ca-xwt.% Sr (x = 0.2, 0.5, 1.0, 2.0) alloys on the osteogenic differentiation and mineralization of pre-osteoblast MC3T3-E1 were studied through typical differentiation markers, such as intracellular alkaline phosphatase (ALP) activity, extracellular collagen secretion and calcium nodule formation. It was shown that Mg-1Ca alloys with different content of Sr promoted cell viability and enhanced the differentiation and mineralization levels of osteoblasts, and Mg-1Ca-2.0Sr alloy had the most remarkable and significant effect among all. To further investigate the underlying mechanisms, RT-PCR and Western Blotting assays were taken to analyze the mRNA expression level of osteogenesis-related genes and intracellular signaling pathways involved in osteogenesis, respectively. RT-PCR results showed that Mg-1Ca-2.0Sr alloy significantly up-regulated the expressions of the transcription factors of Runt-related transcription factor 2 (RUNX2) and Osterix (OSX), Integrin subunits, as well as alkaline phosphatase (ALP), Bone sialoprotein (BSP), Collagen I (COL I), Osteocalcin (OCN) and Osteopontin (OPN). Western Blotting results suggested that Mg-1Ca-2.0Sr alloy rapidly induced extracellular signal-regulated kinase (ERK) activation but showed no obvious effects on c-Jun N terminal kinase (JNK) and p38 kinase of MAPK. Taken together, our results demonstrated that Mg-1Ca-2.0Sr alloy had excellent biocompatibility and osteogenesis via the ERK pathway and is expected to be promising as orthopedic implants and bone repair materials.

SIRT1 was involved in TNF-α-promoted osteogenic differentiation of human DPSCs through Wnt/β-catenin signal

Dental pulp stem cells (DPSCs), as one type of mesenchymal stem cells (MSCs), have the capability of self-renewal and differentiating along the various directions, including osteogenic, chondrogenic, neurogenic, and adipogenic. We previously study and found that tumor necrosis factor-α (TNF-α) promoted osteogenic differentiation of human DPSCs via the Wnt/β-catenin signaling pathway in low concentration while inhibited that in high concentration. In the abovementioned process, we found that sirtuin-1 (SIRT1) had the same change compared with the characteristic protein of bone formation, such as bone morphogenetic protein 2 (BMP2), runt-related transcription factor 2 (Runx2), and collagen I (COL1). We asked whether SIRT1 could regulate osteogenesis of DPSCs. In inflammation microenvironment constructed by TNF-α, we tested the expression changing of SIRT1 and analyzed the function of SIRT1 on osteogenic differentiation of DPSCs. SIRT1 deacetylated β-catenin, and then promote its accumulation in the nucleus. Accumulated β-catenin can lead to transcription of osteogenic characteristic genes. Using the activator of SIRT1, resveratrol, could promote the above-mentioned process of osteogenic differentiation. SIRT1 could regulate osteogenesis of DPSCs through Wnt/β-catenin signal. SIRT1, as a regulator of differentiation of DPSCs, may be a new target for cell-based therapy in oral diseases and other regenerative medicine.

bFGF- and CaPP-Loaded Fibrin Clots Enhance the Bioactivity of the Tendon-Bone Interface to Augment Healing

BACKGROUND

Tendon-to-bone healing is a complex and slow process, and the rate of poor healing remains high. In recent years, several new strategies have been developed that enhance tendon-to-bone healing by increasing the bioactivity. Fibrin clots have been widely used to improve tissue healing and tissue engineering,

HYPOTHESIS

Modified fibrin clots can improve the bioactivity of the tendon-bone interface and histological appearance.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 27 male New Zealand White rabbits were used. Of these, 3 were used for cell isolation, and the remaining 24 rabbits were divided into 2 groups (12 per group) for an in vivo partial patellectomy study. The setting time, degradation time, and basic fibroblast growth factor (bFGF) and ceramide-activated protein phosphatase (CaPP) release kinetics of bFGF- and CaPP-loaded fibrin clots were modified appropriately for early tendon-to-bone healing. In an in vitro experiment, the bFGF- and CaPP-loaded fibrin clots were assessed for cell migration and proliferation by microscopy, MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay, and DAPI (4',6-diamidino-2-phenylindole) assay. Quantitative real-time reverse transcription polymerase chain reaction and a Western blot assay were performed to test for an induction effect of the bFGF- and CaPP-loaded fibrin clots. Finally, for the in vivo experiment, the rabbits were divided into 2 treatment groups: one with bFGF- and CaPP-loaded fibrin clots and one without bFGF- and CaPP-loaded fibrin clots after partial patellectomy in patella-patellar tendon sutured sites. A histological evaluation was performed at 2, 4, and 6 weeks after surgery.

RESULTS

The sitting time and degradation time of the bFGF- and CaPP-loaded fibrin clots were set at 15 seconds and more than 2 weeks, respectively, and the porosity was minimized to achieve the highest levels of cell migration and growth. In the bFGF-CaPP group of the in vitro experiment, cell proliferation increased to a greater extent relative to the control group (P < .05); the mRNA expression of osteopontin, alkaline phosphatase, runt-related transcription factor 2, vascular endothelial growth factor, and collagen type I was upregulated (P < .05); and the relative protein expression of these factors was enhanced (P < .05). In vivo, hematoxylin and eosin staining showed that the tendon-to-bone connections were more mature and more arranged when treated with bFGF- and CaPP-loaded fibrin clots than when untreated, and the histological scores were higher.

CONCLUSION

bFGF- and CaPP-loaded fibrin clots enhanced cell migration and proliferation and the expression of related genes and proteins, which increased the bioactivity of the tendon-bone interface and resulted in the histological improvement of tendon-to-bone healing.

CLINICAL RELEVANCE

As fibrin clots have already been used in clinical practice, bFGF- and CaPP-loaded fibrin clots can be further used to augment healing in the early stages of tendon-to-bone healing.