Source Of Mesenchymal Stromal Cells Research Articles

Superior migration ability of umbilical cord-derived mesenchymal stromal cells (MSCs) toward activated lymphocytes in comparison with those of bone marrow and adipose-derived MSCs.

Introduction: Mesenchymal stromal cells (MSCs) are activated upon inflammation and/or tissue damage and migrate to suppress inflammation and repair tissues. Migration is the first important step for MSCs to become functional; however, the migration potency of umbilical cord-derived MSCs (UC-MSCs) remains poorly understood. Thus, we aimed to assess the migration potency of UC-MSCs in comparison with those of bone marrow-derived MSCs (BM-MSCs) and adipose tissue-derived MSCs (AD-MSCs) and investigate the influence of chemotactic factors on the migration of these cells. Methods: We compared the migration potencies of UC-, BM-, and AD-MSCs toward allogeneic stimulated mononuclear cells (MNCs) in mixed lymphocyte reaction (MLR). The number of MSCs in the upper chamber that migrated toward the MLR in the lower chamber was counted using transwell migration assay. Results and discussion: UC-MSCs showed significantly faster and higher proliferation potencies and higher migration potency toward unstimulated MNCs and MLR than BM- and AD-MSCs, although the migration potencies of the three types of MSCs were comparable when cultured in the presence of fetal bovine serum. The amounts of CCL2, CCL7, and CXCL2 in the supernatants were significantly higher in UC-MSCs co-cultured with MLR than in MLR alone and in BM- and AD-MSCs co-cultured with MLR, although they did not induce the autologous migration of UC-MSCs. The amount of CCL8 was higher in BM- and AD-MSCs than in UC-MSCs, and the amount of IP-10 was higher in AD-MSCs co-cultured with MLR than in UC- and BM-MSCs. The migration of UC-MSCs toward the MLR was partially attenuated by platelet-derived growth factor, insulin-like growth factor 1, and matrix metalloproteinase inhibitors in a dose-dependent manner. Conclusion: UC-MSCs showed faster proliferation and higher migration potency toward activated or non-activated lymphocytes than BM- and AD-MSCs. The functional chemotactic factors may vary among MSCs derived from different tissue sources, although the roles of specific chemokines in the different sources of MSCs remain to be resolved.

A Phase I Dose-Escalation Clinical Trial to Assess the Safety and Efficacy of Umbilical Cord-Derived Mesenchymal Stromal Cells in Knee Osteoarthritis.

Osteoarthritis (OA) is the most common degenerative joint disease. Mesenchymal stromal cells (MSC) are promising cell-based therapy for OA. However, there is still a need for additional randomized, dose-dependent studies to determine the optimal dose and tissue source of MSC for improved clinical outcomes. Here, we performed a dose-dependant evaluation of umbilical cord (UC)-derived MSC (Celllistem) in a murine model and in knee OA patients. For the preclinical study, a classical dose (200.000 cells) and a lower dose (50.000 cells) of Cellistem were intra-articularly injected into the mice knee joints. The results showed a dose efficacy response effect of Cellistem associated with a decreased inflammatory and degenerative response according to the Pritzker OARSI score. Following the same approach, the dose-escalation phase I clinical trial design included 3 sequential cohorts: low-dose group (2 × 106 cells), medium-dose group (20 × 106), and high-dose group (80 × 106). All the doses were safe, and no serious adverse events were reported. Nonetheless, 100% of the patients injected with the high-dose experienced injection-related swelling in the knee joint. According to WOMAC total outcomes, patients treated with all doses reported significant improvements in pain and function compared with baseline after 3 and 6 months. However, the improvements were higher in patients treated with both medium and low dose as compared to high dose. Therefore, our data demonstrate that the intra-articular injection of different doses of Cellistem is both safe and efficient, making it an interesting therapeutic alternative to treat mild and symptomatic knee OA patients. Trial registration ClinicalTrials.gov NCT03810521.

Proliferative Effects of Mesenchymal Stromal Cells on Neuroblastoma Cell Lines: Are They Tumor Promoting or Tumor Inhibiting?

BackgroundNeuroblastoma is a common pediatric malignancy with poor survival for high-risk disease. Mesenchymal stromal cells (MSCs) have innate tumor-homing properties, enabling them to serve as a cellular delivery vehicle, but MSCs have demonstrated variable effects on tumor growth. We compared how placental MSCs (PMSCs) and bone marrow-derived MSCs (BM-MSCs) affect proliferation of neuroblastoma (NB) cells in vitro. MethodsIndirect co-culture assessed proliferative effects of 18 MSCs (early-gestation PMSCs (n = 9), term PMSCs (n = 5), BM-MSCs (n = 4) on three high-risk NB cell lines (NB1643, SH-SY5Y, and CHLA90). Controls were NB cells cultured in media alone. Proliferation was assessed using MTS assay and measured by fold change (fc) over controls. PMSCs were sub-grouped by neuroprotective effect: strong (n = 7), intermediate (n = 3), and weak (n = 4). The relationship between MSC type, PMSC neuroprotection, and PMSC gestational age on NB cell proliferation was assessed. ResultsNB cell proliferation varied between MSC groups. BM-MSCs demonstrated lower proliferative effects than PMSCs (fc 1.18 vs 1.44, p < 0.001). Neither gestational age nor neuroprotection significantly predicted degree of proliferation. Proliferative effects of MSCs varied among NB cell lines. BM-MSCs had less effect on CHLA90 (fc 1.01) compared to NB1643 (fc 1.33) and SH-SY5Y (fc 1.20). Only NB1643 showed a difference between early and term PMSCs (p = 0.04). ConclusionEffects of MSCs on NB cell proliferation vary by MSC source and NB cell line. BM-MSCs demonstrated lower proliferative effects than most PMSCs. MSC neuroprotection was not correlated with proliferation. Improved understanding of MSC proliferation-promoting mechanisms may provide valuable insight into selection of cells best suited as drug delivery vehicles. Level of EvidenceN/A. Type of StudyOriginal Research.

Immunomodulatory-associated gene transcripts to multipotency of bovine amniotic fluid mesenchymal stem cells.

The adnexa fetal tissues are sources of mesenchymal stromal cells (MSCs) due to their noninvasive harvest, with all biological material discarded most of the time. MSCs are a promise regarding to their plasticity, self-renewal, differentiation potentials, immunomodulatory and anti-inflammatory properties, which have made clinical stem cell therapy a reality. The present study aimed to characterize and evaluate the immunomodulation ability of bovine mesenchymal cells collected from bovine amniotic fluid (bAFMSCs) isolated and subjected to sixth consecutive culture passages in vitro. The multilineage properties of the bAFMSCs collections confirmed the ability to undergo adipogenic, chondrogenic and osteogenic differentiation. The mesenchymal gene transcription CD106, CD73, CD29, CD90 and CD166 were detected in bAFMSCs, whereas CD34 and CD45 were not detected. Regarding cytokine mRNA expression, IL2, IL6, INFα, INFβ, INFγ, TNFα and TNFβ were downregulated, while IL10 was highly regulated in all studied passages. The present study demonstrated the immunological properties and multipotency of in vitro bAFMSCs collections, and thus, they can be tested in cattle pathological treatments or multiplication by nuclear transfer cloning.

The Human Placental Amniotic Membrane Mesenchymal-Stromal-Cell-Derived Conditioned Medium Inhibits Growth and Promotes Apoptosis of Human Cholangiocarcinoma Cells In Vitro and In Vivo by Suppressing IL-6/JAK2/STAT3 Signaling.

Mesenchymal stromal cells (MSCs) have recently been shown to play an important role in the growth and progression of many solid tumors, including cholangiocarcinoma (CCA). The human placental amniotic membrane (hPAM) is one of the most favorable sources of MSCs due to its availability and non-invasive harvesting procedure. However, the role of human placental amniotic membrane mesenchymal stromal cells (hPAMSCs) in the growth and progression of human CCA has not yet been determined. This study investigates the effects of conditioned medium derived from hPAMSCs (PA-CM) on the properties of three human CCA cell lines and explores possible mechanisms of action. Varying concentrations of PA-CM were used to treat CCA cells to determine their effects on the proliferation and apoptosis of CCA cells. The results showed that PA-CM inhibited the proliferation and colony-forming capacity of KKU100, KKU213A, and KKU213B cells. PA-CM also promoted the apoptosis of these CCA cells by causing the loss of mitochondrial membrane potential. Western Blotting confirmed that PA-CM induced CCA cell apoptosis by increasing the levels of the Bax/Bcl-2 ratio, cleaved caspase 3, and cleaved PARP, possibly by inhibiting the IL-6/JAK2/STAT3 signaling pathway. Moreover, our in vivo study also confirmed the suppressive effect of hPAMSCs on CCA cells by showing that PA-CM reduced tumor volume in nude mice transplanted with human CCA cells. Taken together, our results demonstrate that PA-CM has potent tumor-suppressive effects on human CCA cells and could potentially be used in combination with chemotherapy to develop a more effective treatment for CCA patients.

Sequential Umbilical Cord Derived Mesenchymal Stromal Cells (MSCs) for the Third-Line Salvage Treatment of Steroid-Refractory Acute GvHD: A Multicenter, Open Label, Phase 1b/2 Trial

Background and Aim: Acute graft-versus-host disease (aGVHD) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT), particularly if treatment is refractory. Human mesenchymal stromal cells (MSCs) have demonstrated safety and efficacy in steroid refractory acute graft versus host disease, due to their well-described immunosuppressive properties, however, clinical trials have resulted in variable success and an optimal source of MSC has yet to be defined. Based on the importance of maternal-fetal interface immune tolerance, the umbilical cord may provide a superior tissue source of MSC to mediate immunomodulation in aGVHD (SR-aGVHD). This study aimed to investigate the safety and efficacy of MSCs delivered as third-line salvage therapy for SR-aGVHD who had received at least two-lines of steroid-containing immunosuppressive therapy. Method: This phase1b/2, multicenter, open-label clinical trial of a third-party, off-the-shelf preparation of human umbilical cord derived mesenchymal stromal cells (hUC-MSCs) (ChiCTR2200061603) enrolled grades II to IV steroid-refractory aGVHD patients who had been treated with at least two-lines of steroid-containing immunosuppressive therapy. This trial consist of 2 parts：a phase Ib dose escalation part using a standard 3+3 design, which planed biweekly i.v. infusions of hUC-MSCs, at 0.5× 10 6 per kg, 1.0× 10 6per kg and 2.0× 10 6 per kg for 3 weeks, to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Phase II of this work is an expansion cohort study of hUC-MSCs at RP2D 1.0×10 6 per kg with 15 patients. The primary endpoint of the study was safety and RP2D. The key secondary endpoints were efficacy of the overall response rate (ORR) at Day 28 and Day 56 defined per the 2014 NIH consensus criteria. Results: From June 23, 2022, through June 12, 2023, a total of 25 patients were enrolled with the median follow up period of 106 (10,210) days. Of the included 25 cases 11 patients (44.0%) were grade III/IV and 14 patients (56.0%) were grade II aGVHD at enrollment. Median patient age was 37.0 (range:24.5-47.0) years, 44.0% male. hUC-MSCs was well tolerated without dose-limiting toxicities in aforementioned three dosages. The reported adverse events (AEs) potentially associated with hUC-MSCs were hypofibrinogenemia (12.0%), upper respiratory tract infection (4.0%), leukopenia (4.0%) and anemia (8.0%) within the median follow-up period of 106 (10, 210) days. Grade 3 or higher AEs were reported in 6 patients (6/25, 24%) with 11 events, all of them were supposed uncorrelated with hUC-MSC. Three patients unfinished the administration:1 was due to withdrawn ICF; 1 was SAE and 1 was due to participate another trial. Up to date of June 12, 2023, twenty of the initial included 25 patients were still in group. And the RP2D of this trial was identified as 1.0× 10 6 per kg. At Day 28, 20 patients (80.0%, 95% CI:59.3%-93.2%) had an overall response, including 10 (40.0%) with complete responses. And at day 56, only one patient loss response, while another non-response patient at day 28 in the dose of 1.0× 10 6 per kg achieved late responses at day 56 ( Table 1). Responses were observed across skin (19/19, 100%), gastrointestinal tract (7/11,72.7%), and liver (2/2, 100.0%) at day 28. Durable overall response at day 56 was 76% (19/25), Figure 1. The median follow-up time after the initiation of hUC-MSC treatment was 106 (10,210) days with the cutoff date of 180 days after recruitment. The probability of 180-day overall survival (OS) and non-relapse mortality was 88.0% (95% CI, 68.8-97.5%) and 8.0% (95% CI, 1.0-26.0%), respectively. The 180-day cumulative incidence of relapse of primary hematologic disease was 8.0% (95%CI,1.0-26.0%). The percentage of total T lymphocyte, neutrophil, cytokine IL-10, IP-10 were statistically decreased in CR group, while CD8+central memory T cell was significantly increased compared to non-CR groups 24h or 96h after hUC-MSC administration (P&amp;lt;0.05）. Conclusion: Collectively, our results support hUC-MSCs as an effective salvage treatment for SR-aGVHD with safe profile. Key words: Acute graft-versus-host disease; allogeneic hematopoietic stem cell transplantation; mesenchymal stromal cells

Anti-inflammatory effect of interleukin-6 highly enriched in secretome of two clinically relevant sources of mesenchymal stromal cells.

Despite several advances in the field of regenerative medicine, clinical management of extensive skin wounds or burns remains a major therapeutic issue. During the past few years, Mesenchymal Stromal Cells (MSCs) have emerged as a novel therapeutic tool to promote tissue repair through their anti-inflammatory, pro-trophic and pro-remodeling effects. They exert their biological activity mainly via the secretion of soluble bioactive molecules such as cytokines, growth factors, proteins and microRNAs which can be encapsulated within extracellular vesicles (EV). The recent discovery of their high plasticity to external stimuli has fostered the development of new targeted therapies known as priming strategies, to enhance their potential. Our team recently showed that Interleukin-1β (IL-1β)-primed gingival MSCs promote wound healing and epidermal engraftment in vitro, and in vivo through their secreted products that contain extracellular vesicles. In the present work, we investigated whether two common sources of MSCs, gingiva and bone marrow, could respond similarly to IL-1β to favor pro-healing capabilities of their secretome. We showed that both primed-MSC sources, or their related secreted products, are able to reduce inflammation in LPS-challenged human monocytic THP-1 cell line. IL-1β priming enhanced MSC secretion of wound healing-related growth factors, cytokines and miRNAs in both sources. Among them, interleukin 6 was shown to be involved in the anti-inflammatory effect of MSC secreted products. Overall, these results underline the pro-healing properties of both MSC sources and their secretome upon IL-1β priming and their potential to improve the current medical treatment of severe wounds.

Dental Stem Cells: classification and applications

In the last decades, the term stem cells has been one of the main topics to be discussed due to its scientific and medical importance, since its implementation in the field of medicine offers us very promising alternatives in the treatment and above all solution of diseases such as diabetes, Alzheimer, Parkinson's disease, cancer, in treatments of traumatology and orthopedics, transplants, oral surgery, as well as the reconstruction of organs and tissues including those of dental origin, among others. Stem cells are undifferentiated cells characterized by their great capacity for self-renewal, clonality and differentiation; they are present in the embryonic and adult stages of life in human beings. At present, a large number of sources of mesenchymal stromal cells (MSC) in the oral cavity are classified into eight main populations, which are very easy to obtain for the dental team, including: dental pulp, exfoliated primary teeth, dental follicle, dental germ, apical papilla, periodontal ligament, gingiva and periosteum. The objective of the following review is to show the panorama of the research from its origin, generalities, classification and application of this group of cells, since in spite of the advances in stem cell biology, some ethical controversies, as well as tumor formation and rejection limit their usefulness. That is why in this review we carefully describe the potential of dental stem cells to differentiate into osteoblasts, osteocytes, odontoblasts, chondrocytes, adipocytes and neural cells.&#x0D;

P-801 Human umbilical cord perivascular cells (HUCPVC) reduce ovarian fibrosis and improve pregnancy rates in a mouse model of natural ovarian aging

Abstract Study question Does repeated intravenous administration of human umbilical cord perivascular cells (HUCPVC) during the period of ovarian aging prevent age-related fertility decline in a mouse model? Summary answer Repeated administration of first trimester and term HUCPVC improved pregnancy rates and reduced ovarian fibrosis in a mouse model of natural ovarian aging. What is known already Mesenchymal stromal cells (MSC), such as first trimester (FTM) and term human umbilical cord perivascular cells (HUCPVC), may be good cell candidates to mitigate side-effects of oncotherapy, including infertility, and are also gaining interest in ovarian rejuvenation strategies. The intraovarian or systemic administration of various sources of mesenchymal stromal cells in animal models of advanced reproductive age have been previously reported to improve ovarian reserve, follicle activation and function, via multiple proposed mechanisms. However, mating studies have not previously been performed to demonstrate fertility preservation. In addition, the optimal dose regimen and timing of treatment has not been established. Study design, size, duration Pre-clinical randomized controlled study in a mouse model of natural ovarian aging from 6 months to 12 months, including a negative control group (vehicle-treated), a cell control group (fibroblast-treated) and 3 experimental groups (HUCPVC, 2 sources and 2 dose regimens; n = 10-15 per group). All parameters were compared with young control female mice (6-8 weeks, 6 months). Cell injections and all assessments were blinded. Participants/materials, setting, methods 6-month-old ICR mice randomized into 4 groups received 6 monthly tail vein injections of 1x106 HUCPVC (FTM or term), fibroblast cells or HBSS (vehicle control). A 5th group received a single injection of FTM HUCPVC at 11M (n = 5). Pregnancy and litter size data were collected after breeding trials. The total number of follicles per ovary and picrosirius red (PSR) staining were quantified. Serum anti-Mullerian hormone (AMH) and C-reactive protein (CRP) were analyzed by ELISA. Main results and the role of chance No differences in mortality rates (P = 0.2) and animal weights were observed. The weight gain in FTM and term HUCPVC treated animals was significantly greater than in the other groups, over the duration of the study (P = 0.04). Animals that received 6 injections of FTM and term HUCPVC showed significantly higher pregnancy rates at 12M (100%, 80%) (P = 0.007; P = 0.048, respectively), when compared to animals that received HBSS (40%) and were similar to pregnancy rates of 6-8weeks (100%) and 6M (77%) groups. Fibroblast-treated and 1x FTM HUCPVC-treated groups showed 60% pregnancy rates. Age-associated declines in litter sizes and ovarian reserve indicators were observed as expected, but not rescued by cell treatments, except for levels of AMH which were increased in the group that received 1x FTM HUCPVC injections when compared to HBSS controls (P = 0.04). Age-associated increases in ovarian stroma fibrosis were observed with aging in the control groups (P &amp;lt; 0.0001), and were significantly reduced in 6x FTM HUPCVC, 6x term HUCPVC and 1x FTM HUCPVC groups, when compared to HBSS and fibroblast controls (P &amp;lt; 0.0001; P = 0.01 and P &amp;lt; 0.0001, respectively). An age-associated increase in CRP (P = 0.01) was significantly decreased in 6x FTM HUCPVC-treated groups, when compared to HBSS (P = 0.04). Limitations, reasons for caution Pregnancy rate (the main outcome measured in this study) may confound some of the secondary outcomes analyzed (CRP levels). Use of ovarian tissue for histological analysis and limited serum samples precluded further molecular analyses to assess potential mechanisms for the effects of HUCPVC. Wider implications of the findings FTM HUCPVC have anti-inflammatory and anti-fibrotic effects, and represent a promising source of MSC to prevent fertility decline in women of advanced reproductive age. Trial registration number Not Applicable

Potential of Oral Cavity Stem Cells for Bone Regeneration: A Scoping Review

Bone loss is a common problem that ranges from small defects to large defects after trauma, surgery, or congenital malformations. The oral cavity is a rich source of mesenchymal stromal cells (MSCs). Researchers have documented their isolation and studied their osteogenic potential. Therefore, the objective of this review was to analyze and compare the potential of MSCs from the oral cavity for use in bone regeneration. Methods: A scoping review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The databases reviewed were PubMed, SCOPUS, Scientific Electronic Library Online (SciELO), and Web of Science. Studies using stem cells from the oral cavity to promote bone regeneration were included. Results: A total of 726 studies were found, of which 27 were selected. The MSCs used to repair bone defects were (I) dental pulp stem cells of permanent teeth, (II) stem cells derived from inflamed dental pulp, (III) stem cells from exfoliated deciduous teeth, (IV) periodontal ligament stem cells, (V) cultured autogenous periosteal cells, (VI) buccal fat pad-derived cells, and (VII) autologous bone-derived mesenchymal stem cells. Stem cells associate with scaffolds to facilitate insertion into the bone defect and to enhance bone regeneration. The biological risk and morbidity of the MSC-grafted site were minimal. Successful bone formation after MSC grafting has been shown for small defects with stem cells from the periodontal ligament and dental pulp as well as larger defects with stem cells from the periosteum, bone, and buccal fat pad. Conclusions: Stem cells of maxillofacial origin are a promising alternative to treat small and large craniofacial bone defects; however, an additional scaffold complement is required for stem cell delivery.

Enhanced Proliferative and Osteogenic Potential of Periodontal Ligament Stromal Cells.

Cell-based therapies using periodontal ligament stromal cells (PDLSC) for periodontal regeneration may represent an alternative source for mesenchymal stromal cells (MSC) to MSC derived from bone marrow (MSC(M)) and adipose tissue (MSC(AT)). We aimed to characterize the osteogenic/periodontal potential of PDLSC in comparison to MSC(M) and MSC(AT). PDLSC were obtained from surgically extracted healthy human third molars, while MSC(M) and MSC(AT) were obtained from a previously established cell bank. Flow cytometry, immunocytochemistry, and cell proliferation analyses provided cellular characteristics from each group. Cells from the three groups presented MSC-like morphology, MSC-related marker expression, and multilineage differentiation capacity (adipogenic, chondrogenic, and osteogenic). In this study, PDLSC expressed osteopontin, osteocalcin, and asporin, while MSC(M) and MSC(AT) did not. Of note, only PDLSC expressed CD146, a marker previously applied to identify PDLSC, and presented higher proliferative potential compared to MSC(M) and MSC(AT). Upon osteogenic induction, PDLSC exhibited higher calcium content and enhanced upregulation of osteogenic/periodontal genes compared to MSC(M) and MSC(AT), such as Runx2, Col1A1 and CEMP-1. However, the alkaline phosphatase activity of PDLSC did not increase. Our findings suggest that PDLSC might be a promising cell source for periodontal regeneration, presenting enhanced proliferative and osteogenic potential compared to MSC(M) and MSC(AT).

First trimester human umbilical cord perivascular cells (HUCPVC) modulate the kynurenine pathway and glutamate neurotransmission in an LPS-induced mouse model of neuroinflammation

BackgroundThe Kynurenine Pathway (KP) of tryptophan degradation and glutamate toxicity is implicated in several neurological disorders, including depression. The therapeutic potential of mesenchymal stromal cells (MSC), owing to their well documented phagocytosis-driven mechanism of immunomodulation and neuroprotection, has been tested in many neurological disorders. However, their potential to influence KP and the glutamatergic system has not yet been investigated. Hence, this study sought to investigate the effect of HUCPVC, a rich and potent source of MSC, on Lipopolysaccharide (LPS)-activated KP metabolites, KP enzymes, and key components of glutamate neurotransmission.MethodsThe immunomodulatory effect of peripherally administered HUCPVC on the expression profile of kynurenine pathway metabolites and enzymes was assessed in the plasma and brain of mice treated with LPS using LCMS and QPCR. An assessment of the glutamatergic system, including selected receptors, transporters and related proteins was also conducted by QPCR, immunohistochemistry and Western blot.ResultsHUCPVC were found to modulate LPS-induced activation of KP enzymes and metabolites in the brain associated with neurotoxicity. Moreover, the reduced expression of the glutamatergic components due to LPS was also found to be significantly improved by HUCPVC.ConclusionsThe immunomodulatory properties of HUCPVC appear to confer neuroprotection, at least in part, through their ability to modulate the KP in the brain. This KP modulation enhances neuroprotective regulators and downregulates neurotoxic consequences, including glutamate neurotoxicity, which is associated with neuroinflammation and depressive behavior.

Toward transplantation tolerance with adipose tissue-derived therapeutics.

Solid organ and composite tissue allotransplanation have been widely applied to treat end-stage organ failure and massive tissue defects, respectively. Currently there are a lot of research endeavors focusing on induction of transplantation tolerance, to relieve the burden derived from long-term immunosuppressant uptake. The mesenchymal stromal cells (MSCs) have been demonstrated with potent immunomodulatory capacities and applied as promising cellular therapeutics to promote allograft survival and induce tolerance. As a rich source of adult MSCs, adipose tissue provides additional advantages of easy accessibility and good safety profile. In recent years, the stromal vascular fraction (SVF) isolated from adipose tissues following enzymatic or mechanical processing without in vitro culture and expansion has demonstrated immunomodulatory and proangiogenic properties. Furthermore, the secretome of AD-MSCs has been utilized in transplantation field as a potential "cell-free" therapeutics. This article reviews recent studies that employ these adipose-derived therapeutics, including AD-MSCs, SVF, and secretome, in various aspects of organ and tissue allotransplantation. Most reports validate their efficacies in prolonging allograft survival. Specifically, the SVF and secretome have performed well for graft preservation and pretreatment, potentially through their proangiogenic and antioxidative capacities. In contrast, AD-MSCs were suitable for peri-transplantation immunosuppression. The proper combination of AD-MSCs, lymphodepletion and conventional immunosuppressants could consistently induce donor-specific tolerance to vascularized composite allotransplants (VCA). For each type of transplantation, optimizing the choice of therapeutics, timing, dose, and frequency of administration may be required. Future progress in the application of adipose-derived therapeutics to induce transplantation tolerance will be further benefited by continued research into their mechanisms of action and the development of standardized protocols for isolation methodologies, cell culture, and efficacy evaluation.

Is mandible derived mesenchymal stromal cells superior in proliferation and regeneration to long bone-derived mesenchymal stromal cells?

Mesenchymal stromal cells (MSCs) are cells with the characteristic ability of self-renewal along with the ability to exhibit multilineage differentiation. Bone marrow (BM) is the first tissue in which MSCs were identified and BM-MSCs are most commonly used among various MSCs in clinical settings. MSCs can stimulate and promote osseous regeneration. Due to the difference in the development of long bones and craniofacial bones, the mandibular-derived MSCs (M-MSCs) have distinct differentiation characteristics as compared to that of long bones. Both mandibular and long bone-derived MSCs are positive for MSC-associated markers such as CD-73, -105, and -106, stage-specific embryonic antigen 4 and Octamer-4, and negative for hematopoietic markers such as CD-14, -34, and -45. As the M-MSCs are derived from neural crest cells, they have embryogenic cells which promote bone repair and high osteogenic potential. In vitro and in vivo animal-based studies demonstrate a higher rate of proliferation and high osteogenic potential for M-MSCs as compared to long-bones MSCs, but in vivo studies in human subjects are lacking. The BM-MSCs have their advantages and limitations. M-MSCs may be utilized as an alternative source of MSCs which can be utilized for tissue engineering and promoting the regeneration of bone. M-MSCs may have potential advantages in the repair of craniofacial or orofacial defects. Considering the utility of M-MSCs in the field of orthopaedics, we have discussed various unresolved questions, which need to be explored for their better utility in clinical practice.

Chronological and Replicative Aging of CD51+/PDGFR-α+ Pulp Stromal Cells

As a crucial source of mesenchymal stromal cells, CD51+/PDGFR-α+ human dental pulp stromal cells (hDPSCs) are promising seeding cells for regenerative medicine. Cellular senescence hinders the translational application of hDPSCs. However, it remains unclear whether chronological and replicative senescence results in distinct outcomes for hDPSCs. To investigate the influence of senescence on DPSCs, we used transgenic lineage tracking, immunofluorescence, flow cytometry, and various molecular experiments to depict the dynamic pattern of hDPSCs in mice and humans during chronological and replicative senescence. The data demonstrated that CD51+/PDGFR-α+ cells were decreased in chronological senescence. Impaired self-renewal and higher ossificatory differentiation were observed in chronologically senescent hDPSCs. Regarding replicative senescence, a decreased CD51+ but upregulated PDGFR-α+ population was observed in culture. Furthermore, weakened self-renewal and osteogenic differentiation were observed in replicatively senescent hDPSCs. In summary, CD51+/PDGFR-α+ hDPSCs decrease in chronologically aged pulp, with self-renewal that is impaired without impaired osteogenic differentiation. However, replicative senescence has a different impact: self-renewal and ossific differentiation are impaired and CD51 expression is reduced, but PDGFR-α expression remains. These findings demonstrate the different outcomes of chronological and replicative senescence in CD51+/PDGFR-α+ hDPSCs. Furthermore, we revealed that impaired self-renewal is the core dysfunction for both types of cellular aging and that osteogenic differentiation capability differs between them. This study provides insights into the influence of chronological and replicative senescence on the characteristics and capabilities of hDPSCs. These advances provide fundamental knowledge to alleviate cellular aging of CD51+/PDGFR-α+ hDPSCs and promote their translational applications.

Evaluating the Effect of Hypoxia on Human Adult Mesenchymal Stromal Cell Chondrogenesis In Vitro: A Systematic Review

Human adult mesenchymal stromal cells (MSCs) from a variety of sources may be used to repair defects in articular cartilage by inducing them into chondrogenic differentiation. The conditions in which optimal chondrogenic differentiation takes place are an area of interest in the field of tissue engineering. Chondrocytes exist in vivo in a normally hypoxic environment and thus it has been suggested that exposing MSCs to hypoxia may also contribute to a beneficial effect on their differentiation. There are two main stages in which MSCs can be exposed to hypoxia, the expansion phase when cells are cultured, and the differentiation phase when cells are induced with a chondrogenic medium. This systematic review sought to explore the effect of hypoxia at these two stages on human adult MSC chondrogenesis in vitro. A literature search was performed on PubMed, EMBASE, Medline via Ovid, and Cochrane, and 24 studies were ultimately included. The majority of these studies showed that hypoxia during the expansion phase or the differentiation phase enhances at least some markers of chondrogenic differentiation in adult MSCs. These results were not always demonstrated at the protein level and there were also conflicting reports. Studies evaluating continuous exposure to hypoxia during the expansion and differentiation phases also had mixed results. These inconsistent results can be explained by the heterogeneity of studies, including factors such as different sources of MSCs used, donor variability, level of hypoxia used in each study, time exposed to hypoxia, and differences in culture methodology.

Comparison Between Cancellous Trabecular and Cortical Specimens from Human Lumbar Spine Samples as an Alternative Source of Mesenchymal Stromal Cells.

Due to their immunosuppressive potential and ability to differentiate into multiple musculoskeletal cell lineages, mesenchymal stromal cells (MSCs) became popular in clinical trials for the treatment of musculoskeletal disorders. The aim of this study was to isolate and characterize native populations of MSCs from human cortical and cancellous bone from the posterior elements of the lumbar spine and determine what source of MSCs yields better quality and quantity of cells to be potentially used for spinal fusion repair. We were able to show that MSCs from trabecular and cortical spine had the typical MSC morphology and expression markers; the ability to differentiate in adipocyte, chondrocyte, or osteoblast but they did not have a consistent pattern in the expression of the specific differentiation lineage genes. Moreover, MSCs from both sites demonstrated an immune suppression profile suggesting that these cells may have a more promising success in applications related to immunomodulation more than exploring their ability to drive osteogenesis to prevent nonunion in spine fusion procedures.

Human Adipose- and Amnion-Derived Mesenchymal Stromal Cells Similarly Mitigate Osteoarthritis Progression in the Dunkin Hartley Guinea Pig

Background: Clinical trials are currently underway to investigate the efficacy of intra-articular administration of mesenchymal stromal cells (MSCs) to mitigate osteoarthritis (OA) progression in the knee. Although multiple MSC sources exist, studies have yet to determine whether differences in therapeutic efficacy exist between them. Purpose: To compare the ability of intra-articularly injected adipose-derived MSCs (AD-MSCs) and amnion-derived MSCs (AM-MSCs) to mitigate the progression of knee OA in a small animal model of spontaneous OA, as well as to compare the therapeutic potential of MSCs in hyaluronic acid (HA) and in HA only with saline (OA) controls. Study Design: Controlled laboratory study. Methods: Injections of AD-MSCs or AM-MSCs suspended in HA or HA only were performed in the rear stifle joints of 3-month-old Dunkin Hartley guinea pigs (DHGPs). Repeat injections occurred at 2 and 4 months after the initial injection in each animal. Contralateral limbs received saline injections and served as untreated controls. Subsequently, joints were analyzed for osteoarthritic changes of the cartilage and subchondral bone via histologic and biochemical analyses. To evaluate MSC retention time in the joint space, DHGPs received a single intra-articular injection of fluorescently labeled AD-MSCs or AM-MSCs, and the fluorescence intensity was longitudinally tracked via an in vivo imaging system. Results: No statistically significant differences in outcomes were found when comparing the ability of AD-MSCs and AM-MSCs to mitigate OA. However, the injection of AD-MSCs, AM-MSCs, and HA-only treatments more effectively mitigated cartilage damage compared with that of saline controls by demonstrating higher amounts of cartilage glycosaminoglycan content and improved histological proteoglycan scoring while reducing the percentage of osteophytes present. Conclusion: Intra-articular injection of AD-MSCs, AM-MSCs, or HA only was able to similarly mitigate the progression of cartilage damage and reduce the percentage of osteophytes compared with that of saline controls in the DHGP. However, this study was unable to establish the superiority of AD-MSCs versus AM-MSCs as a treatment to mitigate spontaneous OA. Clinical Relevance: MSCs demonstrate the ability to mitigate the progression of knee OA and thus may be used in a prophylactic approach to delay the need for end-stage treatment strategies.

PRISMA-Compliant Meta-Analysis of Randomized Controlled Trials on Osteoarthritis of Knee Managed with Allogeneic vs Autologous MSCs: Efficacy and Safety Analysis.

Meta-analysis. Our objective is to review the randomized controlled trials (RCTs) that have been conducted previously on the topic of osteoarthritis of the knee to assess and compare the efficacy and safety of autologous and allogeneic sources of mesenchymal stromal cells (MSCs) in the treatment of osteoarthritis. We searched the electronic databases PubMed, Embase, Web of Science, and the Cochrane Library until August 2021 for randomised controlled trials (RCTs) analysing the efficacy and safety of autologous and allogeneic sources of MSCs in the management of knee osteoarthritis. These searches were conducted independently and in duplicate. The outcomes that were taken into consideration for analysis were the visual analogue score (VAS) for pain, the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), the Lysholm score, and adverse events. The OpenMeta [Analyst] software was utilised to carry out the analysis in the R platform. In total, 21 studies with a total of 936 patients were considered for this analysis. Because none of the studies made a direct comparison of the autologous and allogeneic sources of MSCs, we pooled the results of all of the included studies of both sources and made a comparative analysis of how the two types of MSCs fared in their respective applications. Although both allogeneic and autologous sources of MSCs demonstrated significantly better VAS improvement after 6 months (p = 0.006, p = 0.001), this trend was not maintained after 1 year for the allogeneic source (p = 0.171, p = 0.027). When compared to their respective controls based on WOMAC scores after 1 year, autologous sources (p = 0.016) of MSCs performed better than allogeneic sources (p = 0.186).A similar response was noted between the sources at 2years in their Lysholm scores (p = 0.682, p = 0.017), respectively. Moreover, allogeneic sources (p = 0.039) of MSCs produced significant adverse events than autologous sources (p = 0.556) compared to their controls. Our analysis of literature showed that autologous sources of MSCs stand superior to allogeneic sources of MSC with regard to their consistent efficacy for pain, functional outcomes, and safety. However, we strongly recommend that further studies be conducted that are of a high enough quality to validate our findings and reach a consensus on the best source of MSCs for use in cellular therapy treatments for knee osteoarthritis. The online version contains supplementary material available at 10.1007/s43465-022-00751-z.

Hyperthermia-stimulated tonsil-mesenchymal stromal cells suppress hematological cancer cells through downregulation of IL-6.

There are contradictory reports on the use of mesenchymal stromal cells (MSCs) in cancer therapy. Variable outcomes have been associated with several factors including cancer pathology, experimental procedure, MSC source tissue, and individual genetic differences. It is also known that MSCs exert their therapeutic effects with various paracrine factors released from these cells. The profiles of the factors released from MSCs are altered by heat shock, hypoxia, oxidative stress, starvation or various agents such as inflammatory cytokines, and their therapeutic potential is affected. In this study, the antitumor potential of conditioned media (CM), which contains paracrine factors, of mild hyperthermia-stimulated mesenchymal stromal cells derived from lymphoid organ tonsil tissue (T-MSC) was investigated in comparison with CM obtained from T-MSCs grew under normal culture conditions. CM was obtained from T-MSCs that were successfully isolated from palatine tonsil tissue and characterized. The cytotoxic effect of CM on the growth of hematological cancer cell lines at different concentrations (1:1 and 1:2) was demonstrated by methylthiazoldiphenyl-tetrazolium bromide analysis. In addition, the apoptotic effect of T-MSC-CM treatment was evaluated on the cancer cells using Annexin-V/PI detection method by flow cytometry. The pro/anti-apoptotic and cytokine-related gene expressions were also analyzed by real-time polymerase chain reactionpost T-MSC-CM treatment. In conclusion, we demonstrated that the factors released from hyperthermia-stimulated T-MSCs induced apoptosis in hematological cancer cell lines in a dose-dependent manner. Importantly, our results at the transcriptional level support that the factors and cytokines released from hyperthermia-stimulated T-MSC may exert antitumoral effects in cancer cells by downregulation of IL-6 that promotestumorigenesis. These findings reveal that T-MSC-CM can be a powerful cell-free therapeutical strategy for cancer therapy.