BACKGROUND: The protective effect of mesenchymal stem cells (MSCs) on cardiac ischemia-reperfusion (I/R) injury has been widely reported. Dental pulp-derived mesenchymal stem cells (DP-MSCs) have therapeutic effects on various diseases, including diabetes and cirrhosis. This study aimed to determine the therapeutic effects of DP-MSCs on I/R injury and elucidate the underlying mechanism. METHODS: Myocardial I/R injury model mice were treated with DP-MSCs or a miR-19a-3p mimic. The infarct volume, fibrotic area, pyroptosis, inflammation level, and cardiac function were measured. Cardiomyocytes exposed to hypoxia-reoxygenation were transfected with the miR-19a-3p mimic, miR-19a-3p inhibitor, or negative control. Pyroptosis and protein expression in the interferon regulatory factor 8/mitogen-activated protein kinase (IRF-8/MAPK) pathway were measured. RESULTS: DP-MSCs protected cardiac function in cardiac I/R-injured mice and inhibited cardiomyocyte pyroptosis. The upregulation of miR-19a-3p protected cardiac function, inhibited cardiomyocyte pyroptosis, and inhibited IRF-8/MAPK signaling in cardiac I/R-injured mice. DP-MSCs inhibited cardiomyocyte pyroptosis and the IRF-8/MAPK signaling by upregulating the miR-19a-3p levels in cardiomyocytes injured by I/R. CONCLUSION DP-MSCs protected cardiac function by inhibiting cardiomyocyte pyroptosis through miR-19a-3p under I/R conditions.
Animals ; MicroRNAs/metabolism* ; Pyroptosis/genetics* ; Mesenchymal Stem Cells/metabolism* ; Myocytes, Cardiac/cytology* ; Mice ; Male ; Mice, Inbred C57BL ; Dental Pulp/cytology* ; Myocardial Reperfusion Injury/therapy* ; MAP Kinase Signaling System/physiology*

Steroid-induced osteonecrosis of femoral head (SONFH) is a disease characterized by femoral head collapse and local pain caused by excessive use of glucocorticoids. Peroxisome proliferator-activated receptor-γ (PPARγ) is mainly expressed in adipose tissue. Wnt/β-catenin, AMPK and other related signaling pathways play an important role in regulating adipocyte differentiation, fatty acid uptake and storage. Bone marrow mesenchymal cells (BMSCs) have the ability to differentiate into adipocytes or osteoblasts, and the use of hormones upregulates PPARγ expression, resulting in BMSCs biased towards adipogenic differentiation. The increase of adipocytes affects the blood supply and metabolism of the femoral head, and the decrease of osteoblasts leads to the loss of trabecular bone, which eventually leads to partial or total ischemic necrosis and collapse of the femoral head. MicroRNAs (miRNAs) are a class of short non-coding RNAs that regulate gene expression by inhibiting the transcription or translation of target genes, thereby affecting cell function and disease progression. Studies have shown that miRNAs affect the progression of SONFH by regulating PPARγ lipid metabolism-related signaling pathways. Therefore, it may be an accurate and feasible SONFH treatment strategy to regulate adipogenic-osteoblast differentiation in BMSCs by targeted intervention of miRNA differential expression to improve lipid metabolism. In this paper, the miRNA-mediated PPARγ-related signaling pathways were classified and summarized to clarify their effects on lipid metabolism in SONFH, providing a theoretical reference for miRNA targeted therapy of SONFH, and then providing scientific evidence for SONFH precision medicine.
MicroRNAs/physiology* ; PPAR gamma/metabolism* ; Femur Head Necrosis/metabolism* ; Humans ; Signal Transduction/physiology* ; Lipid Metabolism/physiology* ; Animals ; Cell Differentiation ; Mesenchymal Stem Cells/cytology* ; Glucocorticoids/adverse effects*

OBJECTIVES: To explore the promoting effect of ginsenoside Rb3 (Rb3) on osteogenesis in periodontitis environment, and to explain its mechanism. METHODS: Human periodontal ligament stem cells (hPDLSCs) were cultured by tissue block method and identified by flow cytometry. Cell counting kit-8 (CCK8) method and calcein acetoxymethyl ester/propidium iodide staining were used to detect the effect of Rb3 on the viability of hPDLSCs cells. In vitro cell experiments were divided into control group, 10 μg/mL lipopolysaccharides (LPS) group, 10 μg/mL LPS+100 μmol/L Rb3 group and 10 μg/mL LPS+200 μmol/L Rb3 group. Alkaline phosphatase (ALP) staining was used to detect the ALP activity of hPDLSCs in each group after osteogenesis induction. The expression of hPDLSCs interleukin-6 (IL-6), interleukin-8 (IL-8), runt-related transcription factor 2 (RUNX2) and transforming growth factor-β (TGF-β)genes in each group after osteogenesis was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. Western blot was used to detect the protein expression of hPDLSCs phosphorrylated extracellular signal-regulated kinase (p-ERK) in each group. Sprague-Dawley rats were randomly divided into the control group, ligation group and ligation+Rb3 group. The left molar-maxillary tissue was subjected to micro-computed tomography (micro-CT) scanning. After the scanning, the left molar-maxilla was made into periodontal tissue sections. Hematoxylin-eosin (HE) staining was used to detect the infiltration and loss of adhesion of inflammatory cells. Masson staining was used to detect the destruction of gingival collagen fibers. Immunofluorescence staining was used to detect the protein expression of RUNX2 and p-ERK. The expression of TGF-β in rat gingival tissue was detected by qRT-PCR. The protein expression of IL-6 in peripheral serum of rats was detected by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used to detect the proportion of Treg cells in rat heart blood. The experimental data were statistically analyzed by Graph Pad Prism10.1.2 software. RESULTS: Rb3 had no effect on the cell activity of hPDLSCs. The results of qRT-PCR and ALP staining showed that Rb3 could inhibit the gene expression of IL-6 and IL-8 in inflammatory hPDLSCs, promote TGF-β gene and promote the osteogenic differentiation of inflammatory hPDLSCs. Western blot showed that Rb3 inhibited the protein expression of inflammatory hPDLSCs p-ERK. The results from micro-CT, Masson staining, and HE staining demonstrated that Rb3 promotes alveolar bone formation in rats with periodontitis, while simultaneously inhibiting the destruction of periodontal fibrous tissue, reducing attachment loss, and suppressing inflammatory cell infiltration. The results of flow cytometry showed that Rb3 could promote the differentiation of Treg cells in peripheral blood of periodontitis rats. The results of ELISA and qRT-PCR showed that Rb3 could inhibit the protein expression of IL-6 and promote the gene expression of TGF-β in periodontitis rats. Immunofluorescence results showed that Rb3 could promote the protein expression of RUNX2 and inhibit the protein expression of p-ERK in periodontitis rats. CONCLUSIONS Rb3 can reduce the inflammatory reaction of periodontal tissues in periodontitis rats, and promote the osteogenic differentiation of hPDLSCs by regulating p-ERK pathways.
Animals ; Ginsenosides/pharmacology* ; Osteogenesis/drug effects* ; Periodontitis/metabolism* ; Rats ; Periodontal Ligament/cytology* ; Humans ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Stem Cells/drug effects* ; Interleukin-6/metabolism* ; Rats, Sprague-Dawley ; Interleukin-8/metabolism* ; Cells, Cultured ; MAP Kinase Signaling System/drug effects* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Male ; Phosphorylation ; Lipopolysaccharides ; Extracellular Signal-Regulated MAP Kinases/metabolism* ; Alkaline Phosphatase/metabolism*

OBJECTIVES: Investigating the protective effect of naringenin (NAR) on the osteogenic potential of human periodontal ligament stem cells (hPDLSCs) under oxidative stress and its related mechanisms. METHODS: The oxidative damage model of hPDLSCs was established using hydrogen peroxide (H₂O₂) andthe hPDLSCs were treated with different concentrations of NAR and 0.5 μmol/L forkhead box protein O-1 (FOXO1) inhibitor AS1842856. After that, the cell counting kit-8 (CCK8) was used to determine the optimal concentrations of H₂O₂ and NAR. The alkaline phosphatase (ALP) staining and real time fluorescent quantitative reverse transcription polymerase chain reaction (qRT-PCR) were employed to assess the expression of ALP, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) in hPDLSCs of each group. The enzyme-linked immunosorbent assay (ELISA) and 2',7'-dichlorofluorescin diacetate (DCFH-DA) staining were utilized to evaluate the expression of reactive oxygen species (ROS), malondialdehyde (MDA) and lactate dehydrogenase (LDH) in hPDLSCs. Meanwhile, qRT-PCR and western blot were used to detect the expression levels of FOXO1 and β-catenin, both are pathway related genes and proteins. RESULTS: H₂O₂ exposure led to an increase in oxidative damage in hPDLSCs, characterized by a rise in intracellular ROS levels and increased expression of MDA and LDH (P<0.05). At the same time, the osteogenic differentiation ability of hPDLSCs decreased, as evidenced by lighter ALP staining and reduced expression levels of osteogenic differentiation-related genes ALP, RUNX2 and OCN (P<0.05). Co-treatment with NAR alleviated the oxidative damage in hPDLSCs, enhanced their antioxidant capacity, and restored their osteogenic ability. The FOXO1 inhibitor AS1842856 downregulated the expression of β-catenin (P<0.05) and significantly diminished both the antioxidant effect of NAR and its ability to restore osteogenesis (P<0.05). CONCLUSIONS NAR can enhance the antioxidant capacity of hPDLSCs by activating the FOXO1/β-catenin signaling pathway within hPDLSCs, thereby mitigating oxidative stress damage and alleviating the loss of osteogenic capacity.
Humans ; Oxidative Stress/drug effects* ; Periodontal Ligament/cytology* ; Hydrogen Peroxide ; Forkhead Box Protein O1/metabolism* ; Stem Cells/cytology* ; Flavanones/pharmacology* ; beta Catenin/metabolism* ; Osteogenesis/drug effects* ; Signal Transduction ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Alkaline Phosphatase/metabolism* ; Osteocalcin/metabolism* ; Cells, Cultured ; Cell Differentiation/drug effects*

OBJECTIVES: This study investigated the effects of a polycaprolactone (PCL)-polyethylene glycol (PEG) scaffold incorporated with concentrated growth factor (CGF) on the adhesion, proliferation, and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs). METHODS: The PCL-PEG-CGF composite scaffold was fabricated using an immersion and freeze-drying technique. Its microstructure, mechanical properties, and biocompatibility were systematically characterized. The hPDLSCs were isolated through enzymatic digestion, and the hPDLSCs were identified through flow cytometry. Third-passage hPDLSCs were seeded onto the composite scaffolds, and their adhesion, proliferation and osteogenic differentiation were assessed using CCK-8 assays, 4',6-diamidino-2-phenylindole (DAPI) staining, alkaline phosphatase (ALP) staining, alizarin red staining, and Western blot analysis of osteogenesis-related proteins [Runt-related transcription factor 2 (Runx2), ALP, and morphogenetic protein 2 (BMP2)]. RESULTS: Scanning electron microscopy revealed that the PCL-PEG-CGF composite scaffold exhibited a honeycomb-like structure with heterogeneous pore sizes. The composite scaffold exhibited excellent hydrophilicity, as evidenced by a contact angle (θ) approaching 0° within 6 s. Its elastic modulus was measured at (4.590 0±0.149 3) MPa, with comparable hydrophilicity, fracture tensile strength, and fracture elongation to PCL-PEG scaffold. The hPDLSCs exhibited significantly improved adhesion to the PCL-PEG-CGF composite scaffold compared with the PCL-PEG scaffold (P<0.01). Additionally, cell proliferation was markedly improved in all the experimental groups on days 3, 5, and 7 (P<0.01), and statistically significant differences were found between the PCL-PEG-CGF group and other groups (P<0.01). The PCL-PEG-CGF group showed significantly elevated ALP activity (P<0.05), increased mineralization nodule formation, and upregulated expression of osteogenic-related proteins (Runx2, BMP2 and ALP; P<0.05). CONCLUSIONS The PCL-PEG-CGF composite scaffold exhibited excellent mechanical properties and biocompatibility, enhancing the adhesion and proliferation of hPDLSCs and promoting their osteogenic differentiation by upregulating osteogenic-related proteins.
Humans ; Polyesters/chemistry* ; Periodontal Ligament/cytology* ; Polyethylene Glycols/chemistry* ; Stem Cells/cytology* ; Tissue Scaffolds ; Cell Proliferation ; Osteogenesis ; Cell Differentiation ; Cell Adhesion ; Bone Morphogenetic Protein 2/metabolism* ; Cells, Cultured ; Alkaline Phosphatase/metabolism* ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Intercellular Signaling Peptides and Proteins/pharmacology* ; Tissue Engineering/methods*

Chronic non-healing wounds significantly impair patient rehabilitation and remain a critical clinical challenge. Stem cell-derived exosomes, owing to their biocompatibility and physiological activity, have emerged as a promising therapeutic approach in regenerative medicine. Beyond their intrinsic wound-healing properties, exosomes are increasingly explored as carriers for small-molecule drugs to enhance synergistic treatment effects. Although microRNAs (miRNAs) exhibit potential in promoting cell proliferation and re-epithelialization, their clinical application is hindered by poor stability. In this study, we investigated the therapeutic effects of miR-132-3p-loaded human umbilical mesenchymal stem cell-derived exosomes (miR-132-3p@UMSC-EXOs) on human foreskin fibroblast-1 (HFF-1). Our findings demonstrated that miR-132-3p@UMSC-EXOs significantly enhanced proliferation and migration of HFF-1, while reducing intracellular reactive oxygen species (ROS) levels compared with unloaded exosomes. Furthermore, qRT-PCR and Western blotting analyses revealed that miR-132-3p@UMSC-EXOs modulated the expression of genes associated with extracellular matrix (ECM) remodeling and inflammation, suggesting their potential to upregulate collagen synthesis and improve ECM metabolism. These results highlight the therapeutic promise of miR-132-3p@UMSC-EXOs in accelerating wound healing.
Humans ; MicroRNAs/pharmacology* ; Exosomes/metabolism* ; Mesenchymal Stem Cells/cytology* ; Wound Healing ; Umbilical Cord/cytology* ; Cell Proliferation ; Fibroblasts/cytology* ; Skin/injuries* ; Cell Movement ; Reactive Oxygen Species/metabolism* ; Cells, Cultured

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

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*

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