Mesenchymal stem cells: a perspective from in vitro cultures to in vivo migration and niches

Bone Tissue Engineering Using Human Cells: A Comprehensive Review on Recent Trends, Current Prospects, and Recommendations

The use of proper cells for bone tissue engineering remains a major challenge worldwide. Cells play a pivotal role in the repair and regeneration of the bone tissue in vitro and in vivo. Currently, a large number of differentiated (somatic) and undifferentiated (stem) cells have been used for bone reconstruction alone or in combination with different biomaterials and constructs (e.g., scaffolds). Although the results of the cell transplantation without any supporting or adjuvant material have been very effective with regard to bone healing. Recent advances in bone scaffolding are now becoming new players affecting the osteogenic potential of cells. In the present study, we have critically reviewed all the currently used cell sources for bone reconstruction and discussed the new horizons that are opening up in the context of cell-based bone tissue engineering strategies.

Analysis of Treatment of 3 Patients with Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is an acute liver decompensation that occurs within 4 weeks on the basis of chronic liver disease. At present, the treatments of ACLF include general supportive treatment, etiological treatment, prevention and treatment of complications, artificial liver treatment, and liver transplantation. Many studies suggest that stem cell therapy may become a new treatment for patients with ACLF. Our department has also tried the application of this treatment. Now, there are three cases of stem cell therapy for patients with ACLF by our department which will be briefly reported.

Defining osteoblast and adipocyte lineages in the bone marrow

Bone is a complex endocrine organ that facilitates structural support, protection to vital organs, sites for hematopoiesis, and calcium homeostasis. The bone marrow microenvironment is a heterogeneous niche consisting of multipotent musculoskeletal and hematopoietic progenitors and their derivative terminal cell types. Amongst these progenitors, bone marrow mesenchymal stem/stromal cells (BMSCs) may differentiate into osteogenic, adipogenic, myogenic, and chondrogenic lineages to support musculoskeletal development as well as tissue homeostasis, regeneration and repair during adulthood. With age, the commitment of BMSCs to osteogenesis slows, bone formation decreases, fracture risk rises, and marrow adiposity increases. An unresolved question is whether osteogenesis and adipogenesis are co-regulated in the bone marrow. Osteogenesis and adipogenesis are controlled by specific signaling mechanisms, circulating cytokines, and transcription factors such as Runx2 and Pparγ, respectively. One hypothesis is that adipogenesis is the default pathway if osteogenic stimuli are absent. However, recent work revealed that Runx2 and Osx1-expressing preosteoblasts form lipid droplets under pathological and aging conditions. Histone deacetylase 3 (Hdac3) and other epigenetic regulators suppress lipid storage in preosteoblasts and/or control marrow adiposity. Establishing a better understanding of fat storage in bone marrow cells, as well as the osteoblast-adipocyte relationship within the bone marrow niche is necessary to understand the mechanisms underlying disease- and aging-related marrow fat storage and may lead to the development of new therapeutic targets for "fatty bone" and osteoporosis.

Functional Dynamics Inside Nano- or Microscale Bio-Hybrid Systems

Soft nano- or microgels made by natural or synthetic polymers have been investigated intensively because of their board applications. Due to their porosity and biocompatibility, nano- or microgels can be integrated with various biologics to form a bio-hybrid system. They can support living cells as a scaffold; entrap bioactive molecules as a drug carrier or encapsulate microorganisms as a semi-permeable membrane. Especially, researchers have created various modes of functional dynamics into these bio-hybrid systems. From one side, the encapsulating materials can respond to the external stimulus and release the cargo. From the other side, cells can respond to physical, or chemical properties of the matrix and differentiate into a specific cell type. With recent advancements of synthetic biology, cells can be further programed to respond to certain signals, and express therapeutics or other functional proteins for various purposes. Thus, the integration of nano- or microgels and programed cells becomes a potential candidate in applications spanning from biotechnology to new medicines. This brief review will first talk about several nano- or microgels systems fabricated by natural or synthetic polymers, and further discuss their applications when integrated with various types of biologics. In particular, we will concentrate on the dynamics embedded in these bio-hybrid systems, to dissect their designs and sophisticated functions.

Characterization, recellularization, and transplantation of rat decellularized testis scaffold with bone marrow-derived mesenchymal stem cells

BACKGROUND

Regenerative medicine potentially offers the opportunity for curing male infertility. Native extracellular matrix (ECM) creates a reconstruction platform to replace the organs. In this study, we aimed to evaluate the efficiency of the testis decellularized scaffold as a proper niche for stem cell differentiation toward testis-specific cell lineages.

METHODS

Rats' testes were decellularized by freeze-thaw cycle followed by immersion in deionized distilled water for 2 h, perfused with 1% Triton X-100 through ductus deferens for 4 h, 1% SDS for 48 h and 1% DNase for 2 h. The decellularized samples were prepared for further in vitro and in vivo analyses.

RESULT

Histochemical and immunohistochemistry studies revealed that ECM components such as Glycosaminoglycans (GAGs), neutral carbohydrate, elastic fibers, collagen I & IV, laminin, and fibronectin were well preserved, and the cells were completely removed after decellularization. Scanning electron microscopy (SEM) showed that 3D ultrastructure of the testis remained intact. In vivo and in vitro studies point out that decellularized scaffold was non-toxic and performed a good platform for cell division. In vivo implant of the scaffolds with or without mesenchymal stem cells (MSCs) showed that appropriate positions for transplantation were the mesentery and liver and the scaffolds could induce donor-loaded MSCs or host migrating cells to differentiate to the cells with phenotype of the sertoli- and leydig-like cells. The scaffolds also provide a good niche for migrating DAZL-positive cells; however, they could not differentiate into post meiotic-cell lineages.

CONCLUSION

The decellularized testis can be considered as a promising vehicle to support cell transplantation and may provide an appropriate niche for testicular cell differentiation.

The effect of human placental chorionic villi derived mesenchymal stem cell on triple-negative breast cancer hallmarks

Mesenchymal stem cells (MSCs) can influence the tumour microenvironment (TEM) and play a major role in tumourigenesis. Triple-negative [Ostrogen receptor (ER-), Progesterone receptor (PgR-), and HER2/neu receptor (HER2-)] breast cancer (TNBC) is an aggressive class of BC characterized by poor prognosis and lacks the benefit of routinely available targeted therapies. This study aims to investigate the effect of human placental chorionic villi derived MSCs (CVMSCs) on the behavior of TNBC in vitro. This was done by assaying different cancer hallmarks including proliferation, migration and angiogenesis. Cell proliferation rate of TNBC cell line (MDA-MB231) was monitored in real time using the xCELLigence system. Whereas, Boyden chamber migration assay was used to measure MDA-MB231 motility and invasiveness toward CVMSCs. Finally, a three-dimensional (3D) model using a co-culture system of CVMSCs with MDA-MB231 with or without the addition of human umbilical vein endothelial cells (HUVECs) was created to assess tumour angiogenesis in vitro. CVMSCs were able to significantly reduce the proliferative and migratory capacity of MDA-MB231 cells. Co-culturing of MDA-MB231 with CVMSCs, not only inhibited the tube formation ability of HUVECs but also reduced the expression of the BC characteristic cytokines; IL-10, IL-12, CXCL9 and CXCL10 of CVMSCs. These results support the hypothesis that CVMSCs can influence the behavior of TNBC cells and provides a basic for a potential therapeutic approach in a pre-clinical settings. The data from this study also highlight the complexity of the in vitro cancer angiogenesis model settings and regulations.

Bone alkaline phosphatase and osteocalcin expression of rat's Gingival mesenchymal stem cells cultured in platelet-rich fibrin for bone remodeling (in vitro study)

OBJECTIVE

The aim of this study was to analyze the osteogenic differentiation of rat GMSCs cultured in PRF for bone remodeling.

MATERIALS AND METHODS

GMSCs were isolated from the lower gingival tissue of four healthy, 250 g, 1-month old, male rats (Rattus norvegicus) cut into small fragments, cultured for 2 weeks, and subsequently passaged every 4-5 days. GMSCs isolated in passage 3 were characterized by CD34, CD45, CD44, CD73, CD90, and CD105 using fluorescein isothiocyanate immunocytochemistry (ICC) examination. GMSCs in passage 3-5 cultured in five M24 plates (N = 108; n = 6/group) for 7, 14, and 21 days with three different mediums as follows: Control (-) group: α-Modified Eagle Medium; Control (+) group: High-dose glucose Dulbecco's Modified Eagle's Medium (DMEM-HG) + osteogenic medium; and treatment group: DMEM-HG + osteogenic medium + PRF. GMSCs were osteogenic differentiation cultured in vitro in three different mediums by bone alkaline phosphatase (BALP) and osteocalcin (OSC) marker using ICC monoclonal antibody.

STATISTICAL ANALYSIS USED

The one-way analysis of variance was performed (P < 0.05) based on Shapiro-Wilk and Levene's tests (P > 0.05).

RESULTS

GMSCs were shown to present + CD44, +CD73, +CD90, +CD105 and - CD34, - and CD45 expression as MSCs markers. The treatment group showed the highest BALP expression (16.00 ± 1.732) on day 7, while OSC expression (13.67 ± 2.309) on day 21 showed the statistically significant difference between groups (P < 0.05).

CONCLUSION

GMSCs cultured in PRF demonstrated potential osteogenic differentiation ability capable of accelerating in vitro bone remodeling by enhancing BALP and OSC expression.

Osteogenic potential of gingival stromal progenitor cells cultured in platelet rich fibrin is predicted by core-binding factor subunit-α1/Sox9 expression ratio ( in vitro)

Background: Alveolar bone defect regeneration has long been problematic in the field of dentistry. Gingival stromal progenitor cells (GSPCs) offer a promising solution for alveolar bone regeneration. In order to optimally differentiate and proliferate progenitor cells, growth factors (GFs) are required. Platelet rich fibrin (PRF) has many GFs and can be easily manufactured. Core-binding factor subunit-α1 (CBF-α1) constitutes a well-known osteogenic differentiation transcription factor in SPCs. Sox9, as a chondrogenic transcription factor, interacts and inhibits CBF-α1, but its precise role in direct in vitro osteogenesis remains unknown. GSPCs cultured in vitro in PRF to optimally stimulate osteogenic differentiation has been largely overlooked. The aim of this study was to analyze GSPCs cultured in PRF osteogenic differentiation predicted by CBF-α1/Sox9. Methods: This study used a true experimental with post-test only control group design and random sampling. GPSCs isolated from the lower gingiva of four healthy, 250-gram, 1-month old, male Wistar rats ( Rattus Novergicus) were cultured for two weeks, passaged every 4-5 days. GSPCs in passage 3-5 were cultured in five M24 plates (N=108; n=6/group) for Day 7, Day 14, and Day 21 in three different mediums (control negative group: αModified Eagle Medium; control positive group: High Glucose-Dulbecco's Modified Eagle Medium (DMEM-HG) + osteogenic medium; Treatment group: DMEM-HG + osteogenic medium + PRF). CBF-α1 and Sox9 were examined with ICC monoclonal antibody. A one-way ANOVA continued with Tukey HSD test (p<0.05) based on Kolmogorov-Smirnov and Levene's tests (p>0.05) was performed. Results: The treatment group showed the highest CBF-α1/Sox9 ratio (16.00±3.000/14.33±2.517) on Day 7, while the lowest CBF-α1/Sox9 ratio (3.33±1.528/3.67±1.155) occurred in the control negative group on Day 21, with significant difference between the groups (p<0.05). Conclusion: GSPCs cultured in PRF had potential osteogenic differentiation ability predicted by the CBF-α1/sox9 ratio.

Combined effect of retinoic acid and calcium on the in vitro differentiation of human adipose-derived stem cells to adipocytes

CONTEXT

It has been shown that adipogenesis can be modulated by factors such as all-trans retinoic acid (ATRA) and calcium.

OBJECTIVE

To determine, the combined effect of ATRA and calcium on the differentiation of human adipose-derived stem cells (hADSCs).

METHODS

Mesenchymal stem cells (MSCs) were differentiated into the adipocytes by 0.5 and 1 µM of ATRA and 5 and 10 mM calcium separately or in combination. After MTS assay the differentiation of MSCs to adipocyte was evaluated, Oil Red O staining, GLUT4 concentration and gene expression of PPARG2, adiponectin, and GLUT4 were measured by Real-Time PCR.

RESULTS

Except 10 mM calcium treated group, other groups and more significantly combination treatments could reduce all adipocyte markers compared to the control.

CONCLUSION

These results suggest that ATRA and calcium together have significant inhibitory effect on adipogenesis that can be helpful for finding new mechanisms to prevent or control the adipogenesis.

Durable engraftment of genetically modified FVIII-secreting autologous bone marrow stromal cells in the intramedullary microenvironment

Genetically modified FVIII‐expressing autologous bone marrow‐derived mesenchymal stromal cells (BMSCs) could cure haemophilia A. However, culture‐expanded BMSCs engraft poorly in extramedullary sites. Here, we compared the intramedullary cavity, skeletal muscle, subcutaneous tissue and systemic circulation as tissue microenvironments that could support durable engraftment of FVIII‐secreting BMSC in vivo. A zinc finger nuclease integrated human FVIII transgene into PPP1R12C (intron 1) of culture‐expanded primary canine BMSCs. FVIII‐secretory capacity of implanted BMSCs in each dog was expressed as an individualized therapy index (number of viable BMSCs implanted × FVIII activity secreted/million BMSCs/24 hours). Plasma samples before and after implantation were assayed for transgenic FVIII protein using an anti‐human FVIII antibody having negligible cross‐reactivity with canine FVIII. Plasma transgenic FVIII persisted for at least 48 weeks after implantation in the intramedullary cavity. Transgenic FVIII protein levels were low after intramuscular implantation and undetectable after both intravenous infusion and subcutaneous implantation. All plasma samples were negative for anti‐human FVIII antibodies. Plasma concentrations and durability of transgenic FVIII secretion showed no correlation with the therapy index. Thus, the implantation site microenvironment is crucial. The intramedullary microenvironment, but not extramedullary tissues, supported durable engraftment of genetically modified autologous FVIII‐secreting BMSCs.

Characterization of the interaction between human decidua parietalis mesenchymal stem/stromal cells and natural killer cells

Background

Human decidua parietalis mesenchymal stem/multipotent stromal cells (DPMSCs) have unique phenotypic and functional properties that make them promising candidates for cell-based therapy. Here, we investigated DPMSC interaction with natural killer (NK) cells, and the effects of this interaction on NK cell phenotypic characteristics and functional activities.

Methods

DPMSCs isolated from the decidua parietalis of human fetal membranes were cultured with interleukin (IL)-2-activated and IL-2-unactivated NK cells isolated from healthy human peripheral blood. NK cell proliferation and cytolytic activities were then examined using functional assays. NK cell expression of receptors mediating the cytolytic activity against DPMSCs, and the mechanism underlying this effect on DPMSCs, were also examined using flow cytometry and light microscopy, respectively.

Results

DPMSCs stimulated IL-2-induced proliferation of resting NK cells and the proliferation of activated NK cells. Moreover, IL-2-activated NK cells, but not freshly isolated NK cells, efficiently lysed DPMSCs. The induction of this NK cell cytolytic activity against DPMSCs was mediated by the activating NK cell receptors NKG2D, CD69, NKp30, and NKp44. However, DPMSCs showed a direct induction of NK cell cytolytic activity through CD69. We also found that DPMSCs expressed the ligands for these activating NK cell receptors including Nectin-2, ULBP-2, MICA, and MICB. Although DPMSCs expressed HLA class I molecules, they were susceptible to lysis by NK cells, suggesting that HLA class I antigens do not play a significant role in NK cell cytolytic action. In addition, DPMSCs did not inhibit NK cell cytolytic activity against cancer cells. Importantly, DPMSCs significantly increased NK expression of inflammatory molecules with anticancer activities.

Conclusions

We conclude that DPMSCs have potential for therapeutic application in cancer therapy, but not in transplantation or immunological diseases.

Mechanisms and Mitochondrial Redox Signaling in Photobiomodulation

Photobiomodulation (PBM) involves the use of red or near-infrared light at low power densities to produce a beneficial effect on cells or tissues. PBM therapy is used to reduce pain, inflammation, edema, and to regenerate damaged tissues such as wounds, bones, and tendons. The primary site of light absorption in mammalian cells has been identified as the mitochondria and, more specifically, cytochrome c oxidase (CCO). It is hypothesized that inhibitory nitric oxide can be dissociated from CCO, thus restoring electron transport and increasing mitochondrial membrane potential. Another mechanism involves activation of light or heat-gated ion channels. This review will cover the redox signaling that occurs in PBM and examine the difference between healthy and stressed cells, where PBM can have apparently opposite effects. PBM has a marked effect on stem cells, and this is proposed to operate via mitochondrial redox signaling. PBM can act as a preconditioning regimen and can interact with exercise on muscles.