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Aims: Akr1A1 is a glycolytic enzyme catalyzing the reduction of aldehyde to alcohol. This study aims to delineate the role of Akr1A1 in regulating the adipo-osteogenic lineage differentiation of mesenchymal stem cells (MSCs)., Main Methods: MSCs derived from human bone marrow and Wharton Jelly together with gain- and loss-of-function analysis as well as supplementation with the S-Nitrosoglutathione reductase (GSNOR) inhibitor N6022 were used to study the function of Akr1A1 in controlling MSC lineage differentiation into osteoblasts and adipocytes., Key Findings: Akr1A1 expression, PKM2 activity, and lactate production were found to be decreased in osteoblast-committed MSCs, but PGC-1α increased to induce mitochondrial oxidative phosphorylation. Increased Akr1A1 inhibited the SIRT1-dependent pathway for decreasing the expressions of PGC-1α and TAZ but increasing PPAR γ in adipocyte-committed MSCs, hence promoting glycolysis in adipogenesis. In contrast, Akr1A1 expression, PKM2 activity and lactate production were all increased in adipocyte-differentiated cells with decreased PGC-1α for switching energy utilization to glycolytic metabolism. Reduced Akr1A1 expression in osteoblast-committed cells relieves its inhibition of SIRT1-mediated activation of PGC-1α and TAZ for facilitating osteogenesis and mitochondrial metabolism., Significance: Several metabolism-involved regulators including Akr1A1, SIRT1, PPARγ, PGC-1α and TAZ were differentially expressed in osteoblast- and adipocyte-committed MSCs. More importantly, Akr1A1 was identified as a new key regulator for controlling the MSC lineage commitment in favor of adipogenesis but detrimental to osteogenesis. Such information should be useful to develop perspective new therapeutic agents to reverse the adipo-osteogenic differentiation of BMSCs, in a way to increase in osteogenesis but decrease in adipogenesis., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Hemophilia is a genetic disorder linked to the sex chromosomes, resulting in impaired blood clotting due to insufficient intrinsic coagulation factors. There are approximately one million individuals worldwide with hemophilia, with hemophilia A being the most prevalent form. The current treatment for hemophilia A involves the administration of clotting factor VIII (FVIII) through regular and costly injections, which only provide temporary relief and pose inconveniences to patients. In utero transplantation (IUT) is an innovative method for addressing genetic disorders, taking advantage of the underdeveloped immune system of the fetus. This allows mesenchymal stromal cells to play a role in fetal development and potentially correct genetic abnormalities. The objective of this study was to assess the potential recovery of coagulation disorders in FVIII knockout hemophilia A mice through the administration of human amniotic fluid mesenchymal stromal cells (hAFMSCs) via IUT at the D14.5 fetal stage. The findings revealed that the transplanted human cells exhibited fusion with the recipient liver, with a ratio of approximately one human cell per 10,000 mouse cells and produced human FVIII protein in the livers of IUT-treated mice. Hemophilia A pups born to IUT recipients demonstrated substantial improvement in their coagulation issues from birth throughout the growth period of up to 12 weeks of age. Moreover, FVIII activity reached its peak at 6 weeks of age, while the levels of FVIII inhibitors remained relatively low during the 12-week testing period in mice with hemophilia. In conclusion, the results indicated that prenatal intrahepatic therapy using hAFMSCs has the potential to improve clotting issues in FVIII knockout mice, suggesting it as a potential clinical treatment for individuals with hemophilia A.

Background: Pancreatic ductal adenocarcinoma (PDAC) is a malignant cancer and chemotherapy ineffectively treats PDAC, leading to the requirement for alternative tumor-targeted treatment. Human amniotic fluid mesenchymal stem cells (hAFMSCs) have been revealed to suppress tumor growth in various cancers and they are a strong candidate for treating PDAC., Methods: To evaluate the effects of hAFMSCs on human pancreatic carcinoma cells (PANC1, AsPC1 and BxPC3 cell lines) and the possible mechanism involved, an in vitro cell coculture system was used. A PANC1 orthotopic xenograft mouse model was established and hAFMSCs were injected intravenously at 4 weeks post-xenograft., Results: An in vitro coculture assay showed that hAFMSCs inhibited PANC1 cell proliferation by inducing S phase cell cycle arrest and increased cell apoptosis in a time-dependent manner. In PANC1 cells, hAFMSCs caused the downregulation of Cyclin A and Cyclin B1 as well as the upregulation of p21 (CDKN1A) at 24 h post coculture. The upregulation of pro-apoptotic factors Caspase-3/-8 and Bax at 24 h post coculture reduced the migration and invasion ability of PANC1 cells through inhibiting the epithelial-mesenchymal transition (EMT) process. In a PANC1 orthotopic xenograft mouse model, a single injection of hAFMSCs showed significant tumor growth inhibition with evidence of the modulation of cell cycle and pro-apoptotic regulatory genes and various genes involved in matrix metallopeptidase 7 (MMP7) signaling-triggered EMT process. Histopathological staining showed lower Ki67 levels in tumors from hAFMSCs-treated mice., Conclusions: Our data demonstrated that hAFMSCs strongly inhibit PDAC cell proliferation, tumor growth and invasion, possibly by altering cell cycle arrest and MMP7 signaling-triggered EMT., (© 2022. The Author(s).)

A co-culture model of mesenchymal stem cells (MSCs) and fibroblasts is an efficient and rapid method to evaluate the anti-fibrotic effects of MSCs-based cell therapy. Transforming growth factor (TGF)-β1 plays a key role in promotion of fibroblast activation and differentiation which can induce collagen deposition, increase ECM production in lung tissue, eventually resulted in pulmonary fibrosis. Here, we use this co-culture system and examine the ECM production in activated fibroblasts by western blot and quantitative real-time analysis to understand the therapeutic effects of MSCs.

Total body irradiation (TBI) is frequently used in hematopoietic stem cell transplantation (HSCT) and is associated with many complications due to radiation injury to the normal cells, including normal stem cells. Nevertheless, the effects of TBI on the mesenchymal stromal stem cell (MSC) are not fully understood. Bone marrow-derived MSCs (BM-MSCs) isolated from normal adults were irradiated with 200 cGy twice daily for consecutive 3 days, a regimen identical to that used in TBI-conditioning HSCT. The characteristics, differentiation potential, cytogenetics, hematopoiesis-supporting function, and carcinogenicity of the irradiated BM-MSCs were then compared to the non-irradiated control. The irradiated and non-irradiated MSCs shared similar morphology, phenotype, and hematopoiesis-supporting function. However, irradiated MSCs showed much lower proliferative and differentiative potential. Irradiation also induced clonal cytogenetic abnormalities of MSCs. Nevertheless, the carcinogenicity of irradiated MSCs is low in vitro and in vivo. In parallel with the ex vivo irradiation experiments, decreased proliferative and differentiative abilities and clonal cytogenetic abnormalities can also be found in MSCs isolated from transplant recipients who had received TBI-based conditioning previously. Thus, TBI used in HSCT drastically injury MSCs and may contribute to the development of some long-term complications associated with clonal cytogenetic abnormality and poor adipogenesis and osteogenesis after TBI.

Mesenchymal stem cells (MSCs) are widely considered for treatment of pulmonary fibrosis based on the anti-inflammatory, antifibrotic, antiapoptotic, and regenerative properties of the cells. Recently, elevated levels of oncostatin M (OSM) have been reported in the bronchoalveolar lavage fluid of a pulmonary fibrosis animal model and in patients. In this work, we aimed to prolong engrafted MSC survival and to enhance the effectiveness of pulmonary fibrosis transplantation therapy by using OSM-preconditioned MSCs. OSM-preconditioned MSCs were shown to overexpress type 2 OSM receptor (gp130/OSMRβ) and exhibited high susceptibility to OSM, resulting in upregulation of the paracrine factor, hepatocyte growth factor (HGF). Moreover, OSM-preconditioned MSCs enhanced cell proliferation and migration, attenuated transforming growth factor-β1- or OSM-induced extracellular matrix production in MRC-5 fibroblasts through paracrine effects. In bleomycin-induced lung fibrotic mice, transplantation of OSM-preconditioned MSCs significantly improved pulmonary respiratory functions and downregulated expression of inflammatory factors and fibrotic factors in the lung tissues. Histopathologic examination indicated remarkable amelioration of the lung fibrosis. LacZ-tagged MSCs were detected in the lung tissues of the OSM-preconditioned MSC-treated mice 18 days after post-transplantation. Taken together, our data further demonstrated that HGF upregulation played an important role in mediating the therapeutic effects of transplanted OSM-preconditioned MSCs in alleviating lung fibrosis in the mice. Stem Cells Translational Medicine 2017;6:1006-1017., (© 2016 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

Introduction: Idiopathic pulmonary fibrosis is a progressive diffuse parenchymal lung disorder of unknown etiology. Mesenchymal stem cell (MSC)-based therapy is a novel approach with great therapeutic potential for the treatment of lung diseases. Despite demonstration of MSC grafting, the populations of engrafted MSCs have been shown to decrease dramatically 24 hours post-transplantation due to exposure to harsh microenvironments. Hypoxia is known to induce expression of cytoprotective genes and also secretion of anti-inflammatory, anti-apoptotic and anti-fibrotic factors. Hypoxic preconditioning is thought to enhance the therapeutic potency and duration of survival of engrafted MSCs. In this work, we aimed to prolong the duration of survival of engrafted MSCs and to enhance the effectiveness of idiopathic pulmonary fibrosis transplantation therapy by the use of hypoxia-preconditioned MSCs., Methods: Hypoxic preconditioning was achieved in MSCs under an optimal hypoxic environment. The expression levels of cytoprotective factors and their biological effects on damaged alveolar epithelial cells or transforming growth factor-beta 1-treated fibroblast cells were studied in co-culture experiments in vitro. Furthermore, hypoxia-preconditioned MSCs (HP-MSCs) were intratracheally instilled into bleomycin-induced pulmonary fibrosis mice at day 3, and lung functions, cellular, molecular and pathological changes were assessed at 7 and 21 days after bleomycin administration., Results: The expression of genes for pro-survival, anti-apoptotic, anti-oxidant and growth factors was upregulated in MSCs under hypoxic conditions. In transforming growth factor-beta 1-treated MRC-5 fibroblast cells, hypoxia-preconditioned MSCs attenuated extracellular matrix production through paracrine effects. The pulmonary respiratory functions significantly improved for up to 18 days of hypoxia-preconditioned MSC treatment. Expression of inflammatory factors and fibrotic factor were all downregulated in the lung tissues of the hypoxia-preconditioned MSC-treated mice. Histopathologic examination observed a significant amelioration of the lung fibrosis. Several LacZ-labeled MSCs were observed within the lungs in the hypoxia-preconditioned MSC treatment groups at day 21, but no signals were detected in the normoxic MSC group. Our data further demonstrated that upregulation of hepatocyte growth factor possibly played an important role in mediating the therapeutic effects of transplanted hypoxia-preconditioned MSCs., Conclusion: Transplantation of hypoxia-preconditioned MSCs exerted better therapeutic effects in bleomycin-induced pulmonary fibrotic mice and enhanced the survival rate of engrafted MSCs, partially due to the upregulation of hepatocyte growth factor.

High concentrations of oxygen aggravate the severity of lung injury in patients requiring mechanical ventilation. Although mesenchymal stem cells have been shown to effectively attenuate various injured tissues, there is limited information regarding a role for amniotic fluid stem cells (AFSCs) in treating acute lung injury. We hypothesized that intravenous delivery of AFSCs would attenuate lung injury in an experimental model of hyperoxia-induced lung injury. AFSCs were isolated from EGFP transgenic mice. The in vitro differentiation, surface markers, and migration of the AFSCs were assessed by specific staining, flow cytometry, and a co-culture system, respectively. The in vivo therapeutic potential of AFSCs was evaluated in a model of acute hyperoxia-induced lung injury in mice. The administration of AFSCs significantly reduced the hyperoxia-induced pulmonary inflammation, as reflected by significant reductions in lung wet/dry ratio, neutrophil counts, and the level of apoptosis, as well as reducing the levels of inflammatory cytokine (IL-1β, IL-6, and TNF-α) and early-stage fibrosis in lung tissues. Moreover, EGFP-expressing AFSCs were detected and engrafted into a peripheral lung epithelial cell lineage by fluorescence microscopy and DAPI stain. Intravenous administration of AFSCs may offer a new therapeutic strategy for acute lung injury (ALI), for which efficient treatments are currently unavailable.

Introduction: Pulmonary emphysema is a major component of chronic obstructive pulmonary disease (COPD). Emphysema progression attributed not only to alveolar structure loss and pulmonary regeneration impairment, but also to excessive inflammatory response, proteolytic and anti-proteolytic activity imbalance, lung epithelial cells apoptosis, and abnormal lung remodeling. To ameliorate lung damage with higher efficiency in lung tissue engineering and cell therapy, pre-differentiating graft cells into more restricted cell types before transplantation could enhance their ability to anatomically and functionally integrate into damaged lung. In this study, we aimed to evaluate the regenerative and repair ability of lung alveolar epithelium in emphysema model by using lung epithelial progenitors which pre-differentiated from amniotic fluid mesenchymal stem cells (AFMSCs). Methods: Pre-differentiation of eGFP-expressing AFMSCs to lung epithelial progenitor-like cells (LEPLCs) was established under a modified small airway growth media (mSAGM) for 7-day induction. Pre-differentiated AFMSCs were intratracheally injected into porcine pancreatic elastase (PPE)-induced emphysema mice at day 14, and then inflammatory-, fibrotic-, and emphysema-related indices and pathological changes were assessed at 6 weeks after PPE administration. Results: An optimal LEPLCs pre-differentiation condition has been achieved, which resulted in a yield of approximately 20% lung epithelial progenitors-like cells from AFMSCs in a 7-day period. In PPE-induced emphysema mice, transplantation of LEPLCs significantly improved regeneration of lung tissues through integrating into the lung alveolar structure, relieved airway inflammation, increased expression of growth factors such as vascular endothelial growth factor (VEGF), and reduced matrix metalloproteinases and lung remodeling factors when compared with mice injected with AFMSCs. Histopathologic examination observed a significant amelioration in DNA damage in alveolar cells, detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL), the mean linear intercept, and the collagen deposition in the LEPLC-transplanted groups. Conclusion: Transplantation of predifferentiated AFMSCs through intratracheal injection showed better alveolar regeneration and reverse elastase-induced pulmonary emphysema in PPE-induced pulmonary emphysema mice. [ABSTRACT FROM AUTHOR]

Fractures are the result of fragile bone structures after trauma caused by direct or indirect external impact or strong muscular contraction. Most fracture patients undergo surgical fixation to accelerate the healing process and restore the function of mutilated bone. Promoting the healing process remains an important issue for the treatment of bone fractures. Our previous studies demonstrated the remarkable bone-protective effects of kefir peptides (KPs) in ovariectomized rats and mice. In this study, we further evaluate the efficacy of KPs on fracture healing using a rat model of femoral fracture. Fifteen 8-week-old male Sprague Dawley (SD) rats were divided into the sham, mock, and KPs groups, in which the mock and the KPs groups underwent femur-fracture surgery with nail fixation, while the sham group underwent a sham operation. The next day, rats were orally administered with daily 400 mg/kg of KPs (KPs group) or distilled water (sham and mock groups) for four weeks. X-ray imaging, histochemical staining and serum osteogenic markers were applied for fracture healing evaluation. In vitro, mouse bone marrow mesenchymal stem cells (BMMSCs) and MC3T3-E1 line were subjected to osteoblast differentiation in the presence of KPs and compared with no KPs treatment. The results demonstrated that KPs treatment improved the progression of the fracture healing process (p < 0.05) and significantly increased the expressions of Col1a1, Alp, Spp1 , Vegfa and Cox2 mRNA in the femurs of the KPs-treated fractured rats compared to those of the mock-treated fracture rats. In vitro, KPs treatment promoted bone regeneration factor (Col1a1, Alp, M-csf and Phospho1) expression in MC3T3-E1-derived osteoblast cultures (on Day 3) and enhanced osteogenic differentiation and mineralization in BMMSC-derived osteoblast cultures (on Day 17 and Day 21). This is the first study to show that KPs can help with fracture healing by promoting osteogenic differentiation, and it also suggests that KPs can be used as a nutritional supplement to accelerate fracture healing. [ABSTRACT FROM AUTHOR]