Human and Rat Bone Marrow-Derived Mesenchymal Stem Cells Differ in Their Response to Fibroblast Growth Factor and Platelet-Derived Growth Factor

Cytological Effects of Serum Isolated from Polytraumatized Patients on Human Bone Marrow-Derived Mesenchymal Stem Cells

Due to their immunomodulatory and regenerative capacity, human bone marrow-derived mesenchymal stem cells (hBMSCs) are promising in the treatment of patients suffering from polytrauma. However, few studies look at the effects of sera from polytraumatized patients on hBMSCs. The aim of this study was to explore changes in hBMSC properties in response to serum from polytrauma patients taken at different time points after the trauma incident. For this, sera from 84 patients with polytrauma (collected between 2010 and 2020 in our department) were used. In order to test the differential influence on hBMSC, sera from the 1^st (D1), 5^th (D5), and 10^th day (D10) after polytrauma were pooled, respectively. As a control, sera from three healthy donors (HS), matched with respect to age and gender to the polytrauma group, were collected. Furthermore, hBMSCs from four healthy donors were used in the experiments. The pooled sera of HS, D1, D5, and D10 were analyzed by multicytokine array for pro-/anti-inflammatory cytokines. Furthermore, the influence of the different sera on hBMSCs with respect to cell proliferation, colony forming unit-fibroblast (CFU-F) assay, cell viability, cytotoxicity, cell migration, and osteogenic and chondrogenic differentiation was analyzed. The results showed that D5 serum significantly reduced hBMSC cell proliferation capacity compared with HS and increased the proportion of dead cells compared with D1. However, the frequency of CFU-F was not reduced in polytrauma groups compared with HS, as well as the other parameters. The serological effect of polytrauma on hBMSCs was related to the time after trauma. It is disadvantageous to use BMSCs in polytraumatized patients at least until the fifth day after polytrauma as obvious cytological changes could be found at that time point. However, it is promising to use hBMSCs to treat polytrauma after five days, combined with the concept of “Damage Control Orthopedics” (DCO).

Stem Cell Secretome for Spinal Cord Repair: Is It More than Just a Random Baseline Set of Factors?

Hundreds of thousands of people suffer spinal cord injuries each year. The experimental application of stem cells following spinal cord injury has opened a new era to promote neuroprotection and neuroregeneration of damaged tissue. Currently, there is great interest in the intravenous administration of the secretome produced by mesenchymal stem cells in acute or subacute spinal cord injuries. However, it is important to highlight that undifferentiated neural stem cells and induced pluripotent stem cells are able to adapt to the damaged environment and produce the so-called lesion-induced secretome. This review article focuses on current research related to the secretome and the lesion-induced secretome and their roles in modulating spinal cord injury symptoms and functional recovery, emphasizing different compositions of the lesion-induced secretome in various models of spinal cord injury.

Effects of ginsenoside Rb1 on second-degree burn wound healing and FGF-2/PDGF-BB/PDGFR-β pathway modulation

Background

Panax notoginseng (Burk.) F. H. Chen (P. notoginseng) is a traditional Chinese medicine that has been used therapeutically for cardiovascular diseases, inflammatory diseases and traumatic injuries as well as for external and internal bleeding due to injury. Ginsenoside Rb1, a crucial monomeric active constituent extracted from P. notoginseng, has attracted widespread attention because of its potential anti-inflammatory, bacteriostatic, and cell growth-promoting effects. In this study, the therapeutic effects of ginsenoside Rb1 on second-degree burn in rats and the potential underlying mechanisms were explored.

Methods

A rat model of second-degree burn injury was established, and skin wound healing was monitored at different time points after ginsenoside Rb1 treatment. HE staining was performed to identify burn severity, and biological tissues were biopsied on days 0, 7, 14, and 24 after treatment. Skin wound healing at different time points was monitored by macroscopic observation. Furthermore, IHC, WB, and RT-PCR were utilized to determine the protein and mRNA expression levels of PDGF-BB, PDGFR-β, and FGF-2 in wound tissues after treatment.

Results

HE staining showed that after 24 days of ginsenoside Rb1 treatment, skin tissue morphology was significant improved. Macroscopic observation demonstrated that in ginsenoside Rb1-treated rats, the scab removal time and fur growth time were decreased, and the wound healing rate was increased. Collectively, the results of IHC, WB and RT-PCR showed that PDGF-BB, PDGFR-β, and FGF-2 expressions peaked earlier in ginsenoside Rb1-treated rats than in model rats, consistent with the macroscopic observations.

Conclusion

Collectively, these findings  indicated that ginsenoside Rb1 promotes burn wound healing via a mechanism possibly associated with upregulation of FGF-2/PDGF-BB/PDGFR-β gene and protein expressions.

Synthetic polymers as xeno-free materials for stabilizing basic fibroblast growth factor in human mesenchymal stem cell cultures

Series of sulfonated polymers were evaluated as additives in cell culture media. Some of the compounds, such as sulfated polyvinyl alcohol (PVA), prevented denaturation and loss of basic fibroblast growth factor during cell culture and enhanced human mesenchymal stem cell proliferation. These compounds are xeno-free alternatives of heparin, an animal-derived sulfated saccharide, often used as an additive. To the best our knowledge, this study is the first to show that chemically defined synthetic chemicals, such as sulfated polyvinyl alcohol, can be used for this purpose.

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Basic fibroblast growth factor in stem cell culture medium decreased during culture.

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Basic fibroblast growth factor concentration was correlated with culture results.

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Sulfated materials were evaluated to protect basic fibroblast growth factor.

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Four materials showed protective effect and hence activated cell proliferation.

Electrical Stimulation Decreases Dental Pulp Stem Cell Osteo-/Odontogenic Differentiation

Dental pulp stem cells (DPSCs) have great potential for use in tissue engineering (TE)-based dental treatments. Electrical stimulation (EStim) has been shown to influence cellular functions that could play an important role in the success of TE treatments. Despite many recent studies focused on DPSCs, few have investigated the effect EStim has on these cells. The aim of this research was to investigate the effects of direct current (DC) EStim on osteo-/odontogenic differentiation of DPSCs. To do so cells were isolated from male Sprague Dawley rats (7-8 weeks old), and phenotype characterization and multilineage differentiation analysis were conducted to verify their "stemness." Different voltages of DC EStim were administrated 1 h/day for 7 days, and the effect of EStim on DPSC osteo-/odontogenic differentiation was assessed by measuring calcium and collagen deposition, alkaline phosphatase (ALP) activity, and expression of osteo- and odontogenic marker genes at days 7 and 14 of culture. We found that while 10 and 50 mV/mm of EStim had no effect on cell number or metabolic activity, 100 mV/mm caused a significant reduction in cell number, and 150 mV/mm resulted in cell death. Despite increased gene expression of osteo-/odontogenic gene markers, Osteocalcin, RunX2, BSP, and DMP1, at day 7 in EStim treated cells, 50 mV/mm of EStim decreased collagen deposition and ALP activity at both time points, and calcium deposition was found to be lower at day 14. In conclusion, under the conditions tested, EStim appears to impair DPSC osteo-/odontogenic differentiation. Additional studies are needed to further characterize and understand the mechanisms involved in DPSC response to EStim, with an eye toward its potential use in TE-based dental treatments.