OBJECTIVE: To investigate the effects of sodium valproate (VPA) in inhibiting Erastin-induced ferroptosis in bone marrow mesenchymal stem cells (BMSCs) and its underlying mechanisms. METHODS: BMSCs were isolated from bone marrow of 8-week-old Spragur Dawley rats and identified [cell surface antigens CD90, CD44, and CD45 were analyzed by flow cytometry, and osteogenic and adipogenic differentiation abilities were assessed by alizarin red S (ARS) and oil red O staining, respectively]. Cells of passage 3 were used for the Erastin-induced ferroptosis model, with different concentrations of VPA for intervention. The optimal drug concentration was determined using the cell counting kit 8 assay. The experiment was divided into 4 groups: group A, cells were cultured in osteogenic induction medium for 24 hours; group B, cells were cultured in osteogenic induction medium containing optimal concentration Erastin for 24 hours; group C, cells were cultured in osteogenic induction medium containing optimal concentration Erastin and VPA for 24 hours; group D, cells were cultured in osteogenic induction medium containing optimal concentration Erastin and VPA, and 8 μmol/L EX527 for 24 hours. The mitochondrial state of the cells was evaluated, including the levels of malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS). Osteogenic capacity was assessed by alkaline phosphatase (ALP) activity and ARS staining. Western blot analysis was performed to detect the expressions of osteogenic-related proteins [Runt-related transcription factor 2 (RUNX2) and osteopontin (OPN)], ferroptosis-related proteins [glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and solute carrier family 7 member 11 (SLC7A11)], and pathway-related proteins [adenosine monophosphate-activated protein kinase (AMPK) and Sirtuin 1 (SIRT1)]. RESULTS: The cultured cells were identified as BMSCs. VPA inhibited Erastin-induced ferroptosis and the decline of osteogenic ability in BMSCs, acting through the activation of the AMPK/SIRT1 pathway. VPA significantly reduced the levels of ROS and MDA in Erastin-treated BMSCs and significantly increased GSH levels. Additionally, the expression levels of ferroptosis-related proteins (GPX4, FTH1, and SLC7A11) significantly decreased. VPA also upregulated the expressions of osteogenic-related proteins (RUNX2 and OPN), enhanced mineralization and osteogenic differentiation, and increased the expressions of pathway-related proteins (AMPK and SIRT1). These effects could be reversed by the SIRT1 inhibitor EX527. CONCLUSION VPA inhibits ferroptosis in BMSCs through the AMPK/SIRT1 axis and promotes osteogenesis.
Mesenchymal Stem Cells/metabolism* ; Ferroptosis/drug effects* ; Animals ; Valproic Acid/pharmacology* ; Rats ; Rats, Sprague-Dawley ; Sirtuin 1/metabolism* ; Cell Differentiation/drug effects* ; Cells, Cultured ; AMP-Activated Protein Kinases/metabolism* ; Osteogenesis/drug effects* ; Piperazines/pharmacology* ; Bone Marrow Cells/cytology* ; Reactive Oxygen Species/metabolism* ; Signal Transduction/drug effects*

OBJECTIVE: To investigate the antioxidant and osteogenic induction capabilities of calcium phosphate nanoflowers (hereinafter referred to as nanoflowers) in vitro at different concentrations. METHODS: Nanoflowers were prepared using gelatin, tripolyphosphate, and calcium chloride. Their morphology, microstructure, elemental composition and distribution, diameter, and molecular constitution were characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive spectroscopy. Femurs and tibias were harvested from twelve 4-week-old Sprague Dawley rats, and bone marrow mesenchymal stem cells (BMSCs) were isolated and cultured using the whole bone marrow adherent method, followed by passaging. The third passage cells were identified as stem cells by flow cytometry and then co-cultured with nanoflowers at concentrations of 0, 0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8, 3.2, and 3.6 mg/mL. Cell counting kit 8 (CCK-8) assay was performed to screen for the optimal concentration that demonstrated the best cell viability, which was subsequently used as the experimental concentration for further studies. After co-culturing BMSCs with the screened concentration of nanoflowers, the biocompatibility of the nanoflowers was verified through live/dead cell staining, scratch assay, and cytoskeleton staining. The antioxidant capacity was assessed by using reactive oxygen species (ROS) fluorescence staining. The in vitro osteoinductive ability was evaluated via alkaline phosphatase (ALP) staining, alizarin red staining, and immunofluorescence staining of osteocalcin (OCN) and Runt-related transcription factor 2 (RUNX2). All the above indicators were compared with the control group of normally cultured BMSCs without the addition of nanoflowers. RESULTS: Scanning electron microscopy revealed that the prepared nanoflowers exhibited a flower-like structure; transmission electron microscopy scans discovered that the nanoflowers possessed a multi-layered structure, and high-magnification images displayed continuous atomic arrangements, with the nanoflower diameter measuring (2.00±0.25) μm; energy-dispersive spectroscopy indicated that the nanoflowers contained elements such as C, N, O, P, and Ca, which were uniformly distributed across the flower region; Fourier transform infrared spectroscopy analyzed the absorption peaks of each component, demonstrating the successful preparation of the nanoflowers. Through CCK-8 screening, the concentrations of 0.8, 1.2, and 1.6 mg/mL were selected for subsequent experiments. The live/dead cell staining showed that nanoflowers at different concentrations exhibited good cell compatibility, with the 1.2 mg/mL concentration being the best (P<0.05). The scratch assay results indicated that the cell migration ability in the 1.2 mg/mL group was superior to the other groups (P<0.05). The cytoskeleton staining revealed that the cell morphology was well-extended in all concentration groups, with no significant difference compared to the control group. The ROS fluorescence staining demonstrated that the ROS fluorescence in all concentration groups decreased compared to the control group after lipopolysaccharide induction (P<0.05), with the 1.2 mg/mL group showing the weakest fluorescence. The ALP staining showed blue-purple nodular deposits around the cells in all groups, with the 1.2 mg/mL group being significantly more prominent. The alizarin red staining displayed orange-red mineralized nodules around the cells in all groups, with the 1.2 mg/mL group having more and denser nodules. The immunofluorescence staining revealed that the expressions of RUNX2 and OCN proteins in all concentration groups increased compared to the control group, with the 1.2 mg/mL group showing the strongest protein expression (P<0.05). CONCLUSION The study successfully prepares nanoflowers, among which the 1.2 mg/mL nanoflowers exhibits excellent cell compatibility, antioxidant properties, and osteogenic induction capability, demonstrating their potential as an artificial bone substitute material.
Animals ; Osteogenesis/drug effects* ; Mesenchymal Stem Cells/drug effects* ; Calcium Phosphates/pharmacology* ; Rats, Sprague-Dawley ; Rats ; Antioxidants/chemistry* ; Cells, Cultured ; Cell Differentiation/drug effects* ; Nanostructures/chemistry* ; Tissue Engineering/methods* ; Bone Marrow Cells/cytology* ; Coculture Techniques ; Tissue Scaffolds/chemistry* ; Male ; Biocompatible Materials/chemistry* ; Cell Survival ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Cell Proliferation

The healing of the tendon-bone interface is a complex dynamic process involving the interaction of multiple cellular and molecular signaling pathways. Bone mesenchymal stem cells (BMSCs) have the potential to differentiate into various types of cells, including osteoblasts, chondrocytes and adipocytes, etc., and have the potential to regenerate damaged tissues. They are potential seed cells for promoting tendon-bone healing. How to precisely regulate the proliferation and differentiation of BMSCs to accelerate the process of tendon-bone healing is a current research hotspot. Monomers of traditional Chinese medicine can promote tendon-bone healing by regulating signaling pathways such as Wnt/β-catenin and BMP/Smad to induce osteogenic and chondrogenic differentiation of BMSCs. This article reviews from several aspects such as the regulatory role of related signaling pathways on tendine-bone healing, traditional Chinese medicine monomers and their mechanism of regulating BMSCs to promote tendine-bone healing in order to providing new ideas for promoting tendine-bone healing.
Mesenchymal Stem Cells/cytology* ; Humans ; Animals ; Bone Marrow Cells/cytology* ; Bone and Bones/drug effects* ; Wound Healing/drug effects* ; Medicine, Chinese Traditional ; Tendons/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Signal Transduction/drug effects* ; Cell Differentiation/drug effects*

Objective To investigate the effects and underlying mechanisms of human placental chorionic plate-derived mesenchymal stem cells (hpcMSCs) on cognitive dysfunction, neuroinflammation, neuronal damage and synaptic plasticity in a mouse model of stroke. Methods A mouse model of middle cerebral artery occlusion (MCAO) was adopted. The mice were randomly divided into three groups: sham operation group, MCAO group and hpcMSCs treatment group, with seven mice in each group. The hpcMSCs treatment group received hpcMSCs transplantation on the 1st, 3rd and 10th day after MCAO. One month after MCAO, the cognitive ability of the mice was evaluated by Morris water maze and Y maze behavioral tests; the morphological changes and synaptic functions of hippocampal neurons were analyzed by HE staining, Nissl staining, Golgi staining and immunofluorescence staining techniques; the density and activation status of microglia was analyzed by Fluorescent labeling method; the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6 in brain tissue were analyzed by ELISA; the expressions of phosphorylated-mitogen-activated protein kinase kinase 1 (p-MEK1), phosphorylated-extracellular regulated protein kinase (p-ERK) and phosphorylated-cAMP-response element binding protein (p-CREB) and other proteins related to neuroprotection in the signal pathways were detected by Western blotting; and electrophysiological detection was performed using hippocampal slices in vitro. Results Compared with the MCAO group, mice in the hpcMSCs treatment group showed significant improvements, including improved cognitive ability, alleviated neuroinflammation (demonstrated by reduced microglial activation and decreased levels of inflammatory factors TNF-α, IL-1β and IL-6), and increased neuronal density with normalized morphology of neurons in the hippocampal CA1 region. The treatment group also demonstrated a significantly increased number of Nissl-positive cells and density of dendritic spines of hippocampal neurons, along with restored frequency of miniature excitatory postsynaptic potential (mEPSP). Moreover, hpcMSCs treatment significantly increased the expression levels of p-MEK1, p-ERK and p-CREB in the hippocampus. Conclusion Transplantation of hpcMSCs ameliorates cognitive dysfunction and hippocampal neuronal injury in stroke mice through the reduction of neuroinflammation, restoration of hippocampal neuronal function, promotion of synaptic plasticity and activation of the MEK/ERK/CREB signaling pathway. These findings suggest a new potential therapeutic approach for post-stroke neural repair.
Animals ; Hippocampus/physiopathology* ; Mice ; Cognitive Dysfunction/etiology* ; Mesenchymal Stem Cell Transplantation ; Male ; Neurons/metabolism* ; Stroke/metabolism* ; Humans ; Neuroinflammatory Diseases/therapy* ; Female ; Cyclic AMP Response Element-Binding Protein/metabolism* ; Disease Models, Animal ; Mesenchymal Stem Cells/cytology* ; Mice, Inbred C57BL

Objective To observe the effect of m⁶A methylation regulation on Notch1 pathway on the homing of BMSCs in asthma, and the intervention study of traditional Chinese medicine compound Yanghe Pingchuan Granules. Methods Rat bone mesenchymal stem cells(BMSC)and bronchial epithelial cells were cocultured. The extracted cells were divided into: bronchial epithelial cell group, asthma bronchial epithelial cell+mesenchymal stem cell co-culture group (co-culture group), co-culture cell+normal serum group, coculture cell+serum containing optimal drug group, siRNA FTO+normal serum group, siRNA FTO-NC+normal serum group, and siRNA FTO+serum containing optimal drug group. The vitality and cell cycle changes of co-cultured cells were detected. The level and markers of homing BMSC were detected by immunofluorescence staining. The expression of Notch1 pathway related genes were detected by qRT-PCR. The expression of Notch1 pathway related proteins were detected by Western blot. Results Compared with bronchial epithelial cell group, the co-cultured cell group showed an increase in the homing level of BMSCs and the expression of C-X-C motif chemokine receptor 4 (CXCR4), stromal cell-derived factor 1 (SDF-1), Notch1, transcription factor recombination signal binding protein-J (RBP-J), and hairy enhancer of split 1 (Hes1) proteins. Compared with the co-cultured cell group and co-cultured cell+normal serum group, the co-cultured cell+serum containing optimal drug group showed an increase in the homing level of BMSCs and the expressions of CXCR4 and SDF-1, while the protein and mRNA levels of Notch1 and Hes1 decreased. Compared with the siRNA FTO-NC+normal serum group, the siRNA FTO+normal serum group showed an increase in the levels of Notch1, activated Notch1, RBP-J, Hes1 protein, and cell viability, while the level of homing BMSC decreased. Compared with siRNA FTO+normal serum group, the levels of Notch1, RBP-J mRNA, activated Notch1, and Hes1 protein decreased, while the level of homing BMSCs increased in siRNA FTO+serum containing optimal drug group. The levels of Notch1, RBP-J, and Hes1 mRNA were reduced in the co-cultured cells+serum containing optimal drug group. Compared with siRNA FTO+serum containing optimal drug group, the expressions of Notch1, activated Notch1, RBP-J, Hes1 protein and cell viability decreased, while the level of homing BMSCs increased in the co-cultured cells+serum containing optimal drug group. Conclusion Yanghe Pingchuan Granules may promote the homing of BMSCs in asthma and alleviate asthma inflammation by upregulating the expression of FTO and inhibiting the expression of downstream genes in the Notch1 signaling pathway.
Animals ; Receptor, Notch1/genetics* ; Mesenchymal Stem Cells/cytology* ; Asthma/genetics* ; Drugs, Chinese Herbal/pharmacology* ; Signal Transduction/drug effects* ; Rats ; Coculture Techniques ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics* ; Epithelial Cells/metabolism* ; Rats, Sprague-Dawley ; Cells, Cultured ; Male

PURPOSE: To investigate the regulatory role of nerve injury-induced protein 1 (NINJ1) in the anti-inflammatory function of human umbilical cord mesenchymal stem cells (hUC-MSCs) co-stimulated by interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). METHODS: hUC-MSCs were expanded in vitro using standard protocols, with stem cell characteristics confirmed by flow cytometry and multilineage differentiation assays. The immunomodulatory properties and cellular activity of cytokine-co-pretreated hUC-MSCs were systematically evaluated via quantitative reverse transcription RT-qPCR, lymphocyte proliferation suppression assays, and Cell Counting Kit-8 viability tests. Transcriptome sequencing, Western blotting and small interfering RNA interference were integrated to analyze the regulatory mechanisms of NINJ1 expression. Functional roles of NINJ1 in pretreated hUC-MSCs were elucidated through gene silencing combined with lactate dehydrogenase release assays, Annexin V/Propidium Iodide apoptosis analysis, macrophage co-culture models, and cytokine Enzyme-Linked Immunosorbent Assay. Therapeutic efficacy was validated in a cecal ligation and puncture-induced septic mouse model: 80 mice were randomly allocated into 4 experimental groups (n=20/group): sham group (laparotomy without cecal ligation); phosphate-buffered saline-treated group (cecal ligation and puncture (CLP) + 0.1 mL phosphate-buffered saline); hUC-MSCs (small interfering RNA (siRNA)-interferon-gamma and tumor necrosis factor-alpha co-stimulation (IT))-treated group (CLP + hUC-MSCs transfected with scrambled siRNA); and hUC-MSCs (siNINJ1-IT)-treated group (CLP + hUC-MSCs with NINJ1-targeting siRNA). RESULTS: hUC-MSCs demonstrated compliance with International Society for Cellular Therapy criteria, confirming their stem cell identity. IFN-γ/TNF-α co-pretreatment enhanced the immunosuppressive capacity of hUC-MSCs, accompanied by the reduction of cellular viability, while concurrently upregulating pro-inflammatory cytokines such as interleukin-6 and interleukin-1β. This co-stimulation significantly elevated NINJ1 expression in hUC-MSCs, whereas genetic silencing of NINJ1 effectively suppressed pro-inflammatory cytokine production and attenuated damage-associated molecular patterns release through inhibition of programmed plasma membrane rupture. Furthermore, the NINJ1 interference potentiated the ability of cytokine-pretreated hUC-MSCs to suppress LPS-induced pro-inflammatory responses in RAW264.7 macrophages. In cecal ligation and puncture-induced sepsis model, NINJ1-silenced hUC-MSCs exhibited enhanced therapeutic efficacy, manifested by reduced systemic inflammation and multi-organ damage. CONCLUSION Our findings shed new light on the immunomodulatory functions of cytokine-primed MSCs, offering groundbreaking insights for developing MSC-based therapies against inflammatory diseases via interfering the expression of NINJ1.
Mesenchymal Stem Cells/drug effects* ; Animals ; Interferon-gamma/pharmacology* ; Tumor Necrosis Factor-alpha/pharmacology* ; Humans ; Mice ; Umbilical Cord/cytology* ; Cells, Cultured ; Apoptosis ; Male

Stem cell treatment may enhance erectile dysfunction (ED) in individuals with cavernous nerve injury (CNI). Nevertheless, no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) on ED. We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED. Sprague-Dawley rats (total = 175) were randomly allocated into five groups. A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs (1 × 10 6 cells, 5 × 10 6 cells, and 1 × 10 7 cells in 0.1 ml, respectively). Penile tissues were harvested for histological analysis on 1 day, 3 days, 7 days, 14 days, 28 days, 60 days, and 90 days postsurgery. It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED. Moreover, there was no significant disparity in the effectiveness of various dosages of HUC-MSCs. However, the expression of endothelial markers (rat endothelial cell antigen-1 [RECA-1] and endothelial nitric oxide synthase [eNOS]), smooth muscle markers (alpha smooth muscle actin [α-SMA] and desmin), and neural markers (neurofilament [RECA-1] and neurogenic nitric oxide synthase [nNOS]) increased significantly with prolonged treatment time. Masson's staining demonstrated an increased in the smooth muscle cell (SMC)/collagen ratio. Significant changes were detected in the microstructures of various types of cells. In vivo imaging system (IVIS) analysis showed that at the 1 st day, the HUC-MSCs implanted moved to the site of damage. Additionally, the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.
Male ; Animals ; Erectile Dysfunction/metabolism* ; Rats, Sprague-Dawley ; Mesenchymal Stem Cell Transplantation/methods* ; Rats ; Penis/pathology* ; Humans ; Disease Models, Animal ; Umbilical Cord/cytology* ; Peripheral Nerve Injuries/complications* ; Mesenchymal Stem Cells ; Nitric Oxide Synthase Type III/metabolism* ; Actins/metabolism* ; Nitric Oxide Synthase Type I/metabolism*

OBJECTIVES: To investigate whether human umbilical cord mesenchymal stem cells (HUC-MSCs) play protective effects against white matter injury (WMI) in neonatal rats via activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)/heme oxygenase-1 (HO-1) signaling pathway. METHODS: A neonatal WMI model was established in 3-day-old Sprague-Dawley rats by unilateral common carotid artery ligation combined with hypoxia. The study comprised two parts. (1) Rats were randomized into sham, hypoxia-ischemia (HI), and HUC-MSC groups (n=36 per group); brain tissues were collected at 7, 14, and 21 days after modeling. (2) Rats were randomized into sham, HI, HUC-MSC, and HUC-MSC+ML385 (Nrf2 inhibitor) groups (n=12 per group); tissues were collected 14 days after modeling. Hematoxylin-eosin staining assessed histopathology, and Luxol fast blue staining evaluated myelination. Immunohistochemistry examined the localization and expression of Nrf2, myelin basic protein (MBP), and proteolipid protein (PLP). Immunofluorescence assessed synaptophysin (SYP) and postsynaptic density-95 (PSD-95). Western blotting quantified Nrf2, Keap1, HO-1, SYP, PSD-95, MBP, and PLP. Spatial learning and memory were evaluated by the Morris water maze. RESULTS: At 7, 14, and 21 days after modeling, the sham group showed intact white matter, whereas the HI group exhibited white matter disruption, cellular vacuolation, and disorganized nerve fibers. These pathological changes were attenuated in the HUC-MSC group. Compared with the HI group, the HUC-MSC group showed increased Nrf2 immunopositivity and protein levels, increased HO-1 protein levels, and decreased Keap1 protein levels (P<0.05). Compared with the HI group, the HUC-MSC group had higher SYP and PSD-95 immunofluorescence intensities and protein levels, higher MBP and PLP positivity and protein levels, increased mean optical density of myelin, more platform crossings, and longer time in the target quadrant (all P<0.05). These improvements were reduced in the HUC-MSC+ML385 group compared with the HUC-MSC group (P<0.05). CONCLUSIONS HUC-MSCs may promote oligodendrocyte maturation and synaptogenesis after neonatal WMI by activating the Nrf2/Keap1/HO-1 pathway, thereby improving spatial cognitive function.
NF-E2-Related Factor 2/physiology* ; Animals ; Rats, Sprague-Dawley ; Signal Transduction/physiology* ; Humans ; Rats ; White Matter/pathology* ; Kelch-Like ECH-Associated Protein 1/physiology* ; Umbilical Cord/cytology* ; Heme Oxygenase-1/physiology* ; Animals, Newborn ; Male ; Mesenchymal Stem Cell Transplantation ; Heme Oxygenase (Decyclizing)/physiology* ; Mesenchymal Stem Cells/physiology* ; Female ; Hypoxia-Ischemia, Brain

OBJECTIVE: To prepare clinical-grade human umbilical cord-derived mesenchymal stem cells (hUC-MSC) with high expression of hematopoietic supporting factors and evaluate their stem cell characteristics. METHODS: Fetal umbilical cord tissues were collected from healthy postpartum women during full-term cesarean section. Wharton's jelly was mechanically separated and hUC-MSCs were obtained by explant culture method and enzyme digestion method in an animal serum-free culture system with addition of human platelet lysate. The phenotypic characteristics of hUC-MSCs obtained by two methods were detected by flow cytometry. The differences in proliferation ability between the two groups of hUC-MSCs were identified through CCK-8 assay and colony forming unit-fibroblast (CFU-F) assay. The differences in multilineage differentiation potential between the two groups of hUC-MSCs were identified through induction of adipogenic, osteogenic, and chondrogenic differentiation. The mRNA expression levels of hematopoietic supporting factors such as SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in the two groups of hUC-MSCs were identified by real-time fluorescence quantiative PCR(RT-qPCR). RESULTS: The results of flow cytometry showed that hUC-MSCs obtained by the two methods both expressed high levels of CD73, CD90 and CD105, while lowly expressed CD31, CD45 and HLA-DR. The results of CCK-8 and CFU-F assay showed that the proliferation ability of hUC-MSCs obtained by explant culture method was better than those obtained by enzyme digestion method. The results of the triple lineage differentiation experiment showed that there was no significant difference in multilineage differentiation potential between the two grous of hUC-MSCs. The results of RT-qPCR showed that the mRNA expression levels of hematopoietic supporting factors SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in hUC-MSCs obtained by explant cultrue method were higher than those obtained by enzyme digestion method. CONCLUSION Clinical-grade hUC-MSCs with high expression levels of hematopoietic supporting factors were successfully cultured in an animal serum-free culture system.
Humans ; Mesenchymal Stem Cells/metabolism* ; Umbilical Cord/cytology* ; Cell Differentiation ; Female ; Cell Proliferation ; Cells, Cultured ; Chemokine CXCL12/metabolism* ; Angiopoietin-1/metabolism* ; Vascular Cell Adhesion Molecule-1/metabolism* ; Stem Cell Factor/metabolism* ; Flow Cytometry ; Pregnancy

OBJECTIVE: To investigate the role of extracellular vesicles (EVs) derived from placental tissue and placental mesenchymal stem cells in supporting the growth and function of adult hematopoietic stem and progenitor cells (HSPCs), so as to optimize their culture system. METHODS: EVs were isolated from mouse placental tissue (PL-EV) and placental mesenchymal stem cells (PL-MSC-EV). These EVs were co-cultured with 3 000 adult bone marrow LKS⁺ (lineage^- c-Kit⁺ Sca-1⁺ ) cells for 72 hours at concentrations of 0, 1, 10, 50, 100, and 200 μg/ml. The proportion and absolute count of LKS⁺ cells after co-culture were analyzed by flow cytometry, while their self-renewal and multi-lineage differentiation potential were evaluated using colony-forming unit (CFU) assays. RESULTS: Compared to the blank control group, the proportion of LKS⁺ cells were significantly increased in PL-EV groups at concentrations ≥10 μg/ml after 72 hours of co-culture. Notably, LKS⁺ cells co-cultured at the concentration of 10 μg/ml exhibited the highest absolute count (899±171) and the highest proportion of LT-HSCs (LKS⁺ CD135^- CD34^-) (0.67%±0.07%). In the PL-MSC-EV co-culture system, the absolute count of LKS⁺ cells peaked at the concentration of 1 μg/ml (1011±99 cells), though the proportion of LT-HSCs was relatively low (0.15%±0.05%). The comparison between these two culture systems revealed that PL-EV at 10 μg/ml and PL-MSC-EV at 1 μg/ml displayed the most pronounced effects on LKS⁺ cell proliferation, but with no significant difference between them. CFU assays showed that, in the PL-EV culture system, the number of LKS⁺ colony formed in 1 and 10 μg/ml groups was not significantly different compared with the blank control group. In contrast, in the PL-MSC-EV system, the highest LKS⁺ colony-forming capacity was observed when co-cultured with 1 μg/ml PL-MSC-EV, while a significant reduction was noted at concentrations above 10 μg/ml. CONCLUSION PL-EV and PL-MSC-EV effectively support the growth and function of HSPCs. And PL-MSC-EV exhibits a superior efficacy in preserving the stemness of LKS⁺ cells, thus suggesting its potential for optimizing culture systems of HSPCs.
Mesenchymal Stem Cells/cytology* ; Extracellular Vesicles ; Placenta/cytology* ; Female ; Animals ; Mice ; Pregnancy ; Hematopoietic Stem Cells/cytology* ; Coculture Techniques ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured