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Background: Mesenchymal stem cells (MSCs) play important roles in tissue homeostasis by providing a supportive microenvironmental niche for the hematopoietic system. Cigarette smoking induces systemic abnormalities, including an impeded recovery process after hematopoietic stem cell transplantation. However, the role of cigarette smoking-mediated alterations in MSC niche function have not been investigated., Methods: In the present study, we investigated whether exposure to cigarette smoking extract (CSE) disrupts the hematopoietic niche function of MSCs, and pathways impacted. To investigate the effects on bone marrow (BM)-derived MSCs and support of hematopoietic stem and progenitor cells (HSPCs), mice were repeatedly infused with the CSE named 3R4F, and hematopoietic stem and progenitor cells (HSPCs) supporting function was determined. The impact of 3R4F on MSCs at cellular level were screened by bulk-RNA sequencing and subsequently validated through qRT-PCR. Specific inhibitors were treated to verify the ROS or NLRP3-specific effects, and the cells were then transplanted into the animal model or subjected to coculture with HSPCs., Results: Both direct ex vivo and systemic in vivo MSC exposure to 3R4F resulted in impaired engraftment in a humanized mouse model. Furthermore, transcriptomic profile analysis showed significantly upregulated signaling pathways related to reactive oxygen species (ROS), inflammation, and aging in 3R4F-treated MSCs. Notably, ingenuity pathway analysis revealed the activation of NLRP3 inflammasome signaling pathway in 3R4F-treated MSCs, and pretreatment with the NLRP3 inhibitor MCC950 rescued the HSPC-supporting ability of 3R4F-treated MSCs., Conclusion: In conclusion, these findings indicate that exposure to CSE reduces HSPCs supportive function of MSCs by inducing robust ROS production and subsequent NLRP3 activation., (© 2024. The Author(s).)

We generated a human induced pluripotent stem cell (hiPSC) line, KSCBi003-A, from adipose tissue-derived mesenchymal stem cells (Ad-MSCs) using a Sendai virus-based gene delivery system. We confirmed that the KSCBi003-A has a normal karyotype and short tandem repeat (STR)-based identities that match the parent cells. We also confirmed that the cell line expresses pluripotent stem cell markers such as Nanog, OCT4, SSEA-4, TRA-1-60, and TRA-1-81. We also analyzed that the KSCBi003-A has an ability to differentiate three germ layers (ectoderm, mesoderm, endoderm). This cell line is registered and available at the National Stem Cell Bank, Korea National Institute of Health., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Human mesenchymal stem cell (hMSC) aging may lead to a reduced tissue regeneration capacity and a decline in physiological functions. However, the molecular mechanisms controlling hMSC aging in the context of prelamin A accumulation are not completely understood. In this study, we demonstrate that the accumulation of prelamin A in the nuclear envelope results in cellular senescence and potential downstream regulatory mechanisms responsible for prelamin A accumulation in hMSCs. We show for the first time that ZMPSTE24, which is involved in the post-translational maturation of lamin A, is largely responsible for the prelamin A accumulation related to cellular senescence in hMSCs. Direct binding of miR-141-3p to the 3'UTR of ZMPSTE24 transcripts was confirmed using a 3'UTR-luciferase reporter assay. We also found that miR-141-3p, which is overexpressed during senescence as a result of epigenetic regulation, is able to decrease ZMPSTE24 expression levels, and leads to an upregulation of prelamin A in hMSCs. This study provides new insights into mechanisms regulating MSC aging and may have implications for therapeutic application to reduce age-associated MSC pool exhaustion.

Human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) are useful tools for regenerative medicine due to their capacity for self-renewal and multi-lineage differentiation. The appropriate clinical application of MSCs for regenerative medicine requires an integrated understanding of multiple signaling pathways that regulate cell proliferation, stemness and differentiation. However, the potential molecular mechanisms mediating these functions are not completely understood. The effects of hedgehog (Hh) signaling on the osteogenic differentiation of MSCs are still controversial, and the underlying mechanisms are unclear. In the present study, we evaluated the direct effects of Hh signaling on the osteogenic differentiation of hUCB-MSCs and investigated potential downstream regulatory mechanisms responsible for Hh signaling. We observed that Hh signaling acts as a negative regulator of osteogenic differentiation through the suppression of RNA-binding Msi1, which in turn suppresses the expression of Wnt1 and the miR-148 family, especially miR-148b. Moreover, Hh and Msi1 are considered to be potential stemness markers of hUCB-MSCs due to their differentiation-dependent expression profiles. This study provides new insights into mechanisms regulating MSC differentiation and may have implications for a variety of therapeutic applications in the clinic., (© 2013.)

CD49f (integrin subunit α6) regulates signaling pathways in a variety of cellular activities. However, the role of CD49f in regulating the differentiation and pluripotency of stem cells has not been fully investigated. Therefore, in this study, human mesenchymal stem cells (hMSCs) were induced to form spheres under nonadherent culture conditions, and we found that the CD49f-positive population was enriched in MSC spheres compared with MSCs in a monolayer. The expression of CD49f regulated the ability of hMSCs to form spheres and was associated with an activation of the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway. Furthermore, the forced expression of CD49f modulated the proliferation and differentiation potentials of hMSCs through prolonged activation of PI3K/AKT and suppressed the level of p53. We showed that the pluripotency factors OCT4 and SOX2 were recruited to the putative promoter region of CD49f, indicating that OCT4 and SOX2 play positive roles in the expression of CD49f. Indeed, CD49f expression was upregulated in human embryonic stem cells (hESCs) compared with hMSCs. The elevated level of CD49f expression was significantly decreased upon embryoid body formation in hESCs. In hESCs, the knockdown of CD49f downregulated PI3K/AKT signaling and upregulated the level of p53, inducing differentiation into three germ layers. Taken together, our data suggest that the cell-surface protein CD49f has novel and dynamic roles in regulating the differentiation potential of hMSCs and maintaining pluripotency., (Copyright © 2012 AlphaMed Press.)

Niemann Pick disease type C1 (NPC) is an autosomal recessive disease characterized by progressive neurological deterioration leading to premature death. In this study, we hypothesized that human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have the multifunctional abilities to ameliorate NPC symptoms in the brain. To test this hypothesis, hUCB-MSCs were transplanted into the hippocampus of NPC mice in the early asymptomatic stage. This transplantation resulted in the recovery of motor function in the Rota Rod test and impaired cholesterol homeostasis leading to increased levels of cholesterol efflux-related genes such as LXRα, ABCA1, and ABCG5 while decreased levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase were observed in NPC mice. In the cerebrum, hUCB-MSCs enhanced neuronal cell survival and proliferation, where they directly differentiated into electrically active MAP2-positive neurons as demonstrated by whole-cell patch clamping. In addition, we observed that hUCB-MSCs reduced Purkinje neuronal loss by suppression of inflammatory and apoptotic signaling in the cerebellum as shown by immunohistochemistry. We further investigated how hUCB-MSCs enhance cellular survival and inhibit apoptosis in NPC mice. Neuronal cell survival was associated with increased PI3K/AKT and JAK2/STAT3 signaling; moreover, hUCB-MSCs modulated the levels of GABA/glutamate transporters such as GAT1, EAAT2, EAAT3, and GAD6 in NPC mice as assessed by Western blot analysis. Taken together, our findings suggest that hUCB-MSCs might play multifunctional roles in neuronal cell survival and ameliorating motor deficits of NPC mice.

It is not clear whether adult stem cell extracellular matrix (ECM) can regulate cancer cells. We demonstrated that the ECM produced by UCB-MSCs was able to arrest the growth of metastatic tumor cells by upregulating levels of PTEN in aggressive cancer cells. Human UCB-MSCs produced dickkopf (DKK1) are capable of inhibiting cancer cell proliferation but has no contribution to the tumor inhibition effect of UCB-MSC ECM. This study also provides an innovative approach to specifically examine the effect of stem cell microenvironments on cancer cells without the complexity of cell-cell interactions. In conclusion, human UCB-MSC ECM prohibits cancer cell proliferation., (2010 Elsevier Ireland Ltd. All rights reserved.)

Background: REX1/ZFP42 is a well-known embryonic stem cell (ESC) marker. However, the role of REX1, itself, is relatively unknown because the function of REX1 has only been reported in the differentiation of ESCs via STAT signaling pathways. Human mesenchymal stem cells (hMSCs) isolated from young tissues and cancer cells express REX1., Methodology/principal Finding: Human umbilical cord blood-derived MSCs (hUCB-MSCs) and adipose tissue-derived MSCs (hAD-MSCs) strongly express REX1 and have a lower activation status of p38 MAPK, but bone marrow-derived MSCs (hBM-MSCs) have weak REX1 expression and higher activation of p38 MAPK. These results indicated that REX1 expression in hMSCs was positively correlated with proliferation rates but inversely correlated with the phosphorylation of p38 MAPK. In hUCB-MSCs, the roles of REX1 and p38 MAPK were investigated, and a knockdown study was performed using a lentiviral vector-based small hairpin RNA (shRNA). After REX1 knockdown, decreased cell proliferation was observed. In REX1 knocked-down hUCB-MSCs, the osteogenic differentiation ability deteriorated, but the adipogenic potential increased or was similar to that observed in the controls. The phosphorylation of p38 MAPK in hUCB-MSCs significantly increased after REX1 knockdown. After p38 MAPK inhibitor treatment, the cell growth in REX1 knocked-down hUCB-MSCs almost recovered, and the suppressed expression levels of CDK2 and CCND1 were also restored. The expression of MKK3, an upstream regulator of p38 MAPK, significantly increased in REX1 knocked-down hUCB-MSCs. The direct binding of REX1 to the MKK3 gene was confirmed by a chromatin immunoprecipitation (ChIP) assay., Conclusions/significance: These findings showed that REX1 regulates the proliferation/differentiation of hMSCs through the suppression of p38 MAPK signaling via the direct suppression of MKK3. Therefore, p38 MAPK and REX-1 status can determine the cell fate of adult stem cells (ASCs). These results were the first to show the role of REX1 in the proliferation/differentiation of ASCs.

Human umbilical cord blood-derived mesenchymal stem cells (MSCs) are known to possess the potential for multiple differentiations abilities in vitro and in vivo. In canine system, studying stem cell therapy is important, but so far, stem cells from canine were not identified and characterized. In this study, we successfully isolated and characterized MSCs from the canine umbilical cord and its fetal blood. Canine MSCs (cMSCs) were grown in medium containing low glucose DMEM with 20% FBS. The cMSCs have stem cells expression patterns which are concerned with MSCs surface markers by fluorescence- activated cell sorter analysis. The cMSCs had multipotent abilities. In the neuronal differentiation study, the cMSCs expressed the neuronal markers glial fibrillary acidic protein (GFAP), neuronal class III beta tubulin (Tuj-1), neurofilament M (NF160) in the basal culture media. After neuronal differentiation, the cMSCs expressed the neuronal markers Nestin, GFAP, Tuj-1, microtubule-associated protein 2, NF160. In the osteogenic & chondrogenic differentiation studies, cMSCs were stained with alizarin red and toluidine blue staining, respectively. With osteogenic differentiation, the cMSCs presented osteoblastic differentiation genes by RT-PCR. This finding also suggests that cMSCs might have the ability to differentiate multipotentially. It was concluded that isolated MSCs from canine cord blood have multipotential differentiation abilities. Therefore, it is suggested that cMSCs may represent a be a good model system for stem cell biology and could be useful as a therapeutic modality for canine incurable or intractable diseases, including spinal cord injuries in future regenerative medicine studies.

Background Aims: Mesenchymal stromal cells (MSC) have been studied intensively in regenerative medicine. However, their therapeutic potential against tumor formation and cancer metastasis is still unclear. The effects of transplantation of MSCs in early-stage of carcinogenesis, should be evaluated., Methods: MSC isolated from human umbilical cord blood (UCB) and adipose tissue (AD) were transplanted in a mouse cancer metastasis model. The effects of MSC on tumor growth and metastasis were analyzed. The effects of transplantation of MSC into the mouse model at very early stage carcinogenesis were also evaluated., Results: Human MSC reduced lung metastasis and inhibited the growth of human breast cancer cells by inducing apoptosis. In addition, transplantation of both UCB and AD MSC into a cancer model with no detectable clinical symptoms did not appear to promote tumor growth or metastasis., Conclusions: We evaluated the effect of MSC derived from human UCB and AD tissue in a tumor model. Our findings may help to elucidate the interaction between cancer cells and MSC, as well as the application of MSC to clinical trials.

Stem cell-based therapy has recently emerged for use in novel therapeutics for incurable diseases. For successful recovery from neurologic diseases, the most pivotal factor is differentiation and directed neuronal cell growth. In this study, we fabricated three different widths of a micro-pattern on polydimethylsiloxane (PDMS; 1, 2, and 4 microm). Surface modification of the PDMS was investigated for its capacity to manage proliferation and differentiation of neural-like cells from umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs). Among the micro-patterned PDMS fabrications, the 1 microm-patterned PDMS significantly increased cell proliferation and most of the cells differentiated into neuronal cells. In addition, the 1 microm-patterned PDMS induced an increase in cytosolic calcium, while the differentiated cells on the flat and 4 microm-patterned PDMS had no response. PDMS with a 1 microm pattern was also aligned to direct orientation within 10 degrees angles. Taken together, micro-patterned PDMS supported UCB-MSC proliferation and induced neural like-cell differentiation. Our data suggest that micro-patterned PDMS might be a guiding method for stem cell therapy that would improve its therapeutic action in neurological diseases.

Current approaches of biomaterials for the repair of critical-sized bone defects still require immense effort to overcome numerous obstacles. The biodegradable polymer-based scaffolds have been required to expand further function for bone tissue engineering. Poly(lactic-co-glycolic) acid (PLGA) is one of the most common biopolymers owing to its biodegradability for tissue regenerations. However, there are major clinical challenges that the byproducts of the PLGA cause an acidic environment of implanting site. The critical processes in bone repair are osteogenesis, angiogenesis, and inhibition of excessive osteoclastogenesis. In this study, the porous PLGA (P) scaffold was combined with magnesium hydroxide (MH, M) and bone-extracellular matrix (bECM, E) to improve anti-inflammatory ability and osteoconductivity. Additionally, the bioactive polydeoxyribonucleotide (PDRN, P) was additionally incorporated in the existing PME scaffold. The prepared PMEP scaffold has pro-osteogenic and pro-angiogenic effects and inhibition of osteoclast due to the PDRN, which interacts with the adenosine A2A receptor agonist that up-regulates expression of vascular endothelial growth factor (VEGF) and down-regulates inflammatory cytokines. The PMEP scaffold has superior biological properties for human bone-marrow mesenchymal stem cells (hBMSCs) adhesion, proliferation, and osteogenic differentiation in vitro. Moreover, the gene expressions related to osteogenesis and angiogenesis of hBMSCs increased and the inflammatory factors decreased on the PMEP scaffold. In conclusion, it provides a promising strategy and clinical potential candidate for bone tissue regeneration and repairing bone defects. [ABSTRACT FROM AUTHOR]