Surface Markers CD44 Research Articles

A transcriptomic analysis of dental pulp stem cell senescence in vitro

Background/purposeThe use of human dental pulp stem cells (hDPSCs) as autologous stem cells for tissue repair and regenerative techniques is a significant area of global research. The objective of this study was to investigate the effects of long-term in vitro culture on the multidifferentiation potential of hDPSCs and the potential molecular mechanisms involved.Materials and methodsThe tissue block method was used to extract hDPSCs from orthodontic-minus-extraction patients, which were then expanded and cultured in vitro for 12 generations. Stem cells from passages three, six, nine, and twelve were selected. Flow cytometry was used to detect the expression of stem cell surface markers, and CCK-8 was used to assess cell proliferation. β-Galactosidase staining was employed to detect cellular senescence, Alizarin Red S staining to assess osteogenic potential, and Oil Red O staining to evaluate lipogenic capacity. RNA sequencing (RNA-seq) was conducted to identify differentially expressed genes in DPSCs and investigate their potential mechanisms.ResultsWith increasing passage numbers, pulp stem cells showed an increase in senescence and a decrease in proliferative capacity and osteogenic–lipogenic multidifferentiation potential. The expression of stem cell surface markers CD34 and CD45 was stable, whereas the expression of CD73, CD90, and CD105 decreased with increasing passages. According to the RNA-seq analysis, the differentially expressed genes CFH, WNT16, HSD17B2, IDI1, and COL5A3 may be associated with stem cell senescence.ConclusionIncreased in vitro expansion induced cellular senescence in pulp stem cells, which resulted in a reduction in their proliferative capacity and osteogenic–lipogenic differentiation potential. The differential expression of genes such as CFH, WNT16, HSD17B2, IDI1, and COL5A3 may represent a potential mechanism for the induction of cellular senescence in pulp stem cells.

Effects of Replicative Senescence of Human Chorionic MSCs on their EV-miRNA Profile.

Chorionic mesenchymal stromal cells (CHO-MSCs) and their extracellular vesicles (EVs) are becoming increasingly popular, since chorion is ethically harmless and an easily accessible source of MSCs. However, until now there is only a limited number of studies with a thorough characterization of CHO-MSCs derived EVs and their miRNA profile. In this study, we monitored changes in the EV-miRNA profile between early and late passage of human CHO-MSCs. First, senescence of CHO-MSCs was induced by serial passaging and confirmed by morphological changes, shortened telomeres and changes in the expression of selected genes. The expression of MSCs-specific surface markers CD73, CD90, CD105 did not change with increasing passages. Next, EVs and their miRNA profiles were compared between early vs late passage cells. Number of EVs and their size were not significantly changed. Seven of the top 10 most expressed EV-miRNAs were common to both early and late passages. A differential expression study between early and late passages identified 37 significantly differentially expressed EV-miRNAs, out of which 23 were found to be associated with pathways of cellular senescence based on KEGG pathway analysis. A set of 9 miRNAs were identified as the most frequently associated with senescence and/or with the most altered expression between early and late passages, out of which miR-145-5p, miR-335-5p and miR-199b-3p were the most significant downregulated miRNAs in late passages. The most upregulated EV-miRNAs were miR-1307-3p, miR-3615 and miR320b. Targeting these miRNAs in future experiments may prolong the therapeutic potential of CHO-MSCs and their EVs.

Role of mitochondria in endogenous renal repair.

Renal tubules have potential to regenerate and repair after mild-to-moderate injury. Proliferation of tubular epithelial cells represents the initial step of this reparative process. Although for many years, it was believed that proliferating cells originated from a pre-existing intra-tubular stem cell population, there is now consensus that surviving tubular epithelial cells acquire progenitor properties to regenerate the damaged kidney. Scattered tubular-like cells (STCs) are dedifferentiated adult renal tubular epithelial cells that arise upon injury and contribute to renal self-healing and recovery by replacing lost neighboring tubular epithelial cells. These cells are characterized by the co-expression of the stem cell surface markers CD133 and CD24, as well as mesenchymal and kidney injury markers. Previous studies have shown that exogenous delivery of STCs ameliorates renal injury and dysfunction in murine models of acute kidney injury, underscoring the regenerative potential of this endogenous repair system. Although STCs contain fewer mitochondria than their surrounding terminally differentiated tubular epithelial cells, these organelles modulate several important cellular functions, and their integrity and function are critical to preserve the reparative capacity of STCs. Recent data suggest that the microenviroment induced by cardiovascular risk factors, such as obesity, hypertension, and renal ischemia may compromise STC mitochondrial integrity and function, limiting the capacity of these cells to repair injured renal tubules. This review summarizes current knowledge of the contribution of STCs to kidney repair and discusses recent insight into the key role of mitochondria in modulating STC function and their vulnerability in the setting of cardiovascular disease.

Regulatory effect of Diwu Yanggan Decoction on lysoglycerophospholipids in circulating exosomes in a mouse model of nonalcoholic fatty liver disease

To evaluate the regulatory effect of Diwu Yanggan (DWYG) Decoction on lysoglycerophospholipids (Lyso-GPLs) in circulating exosomes in a mouse model of nonalcoholic fatty liver disease (NAFLD). Circulating exosomes isolated from mouse serum by size exclusion chromatography were morphologically characterized using transmission electron microscope and examined for surface markers CD9, CD63 and TSG101 using Western blotting. Twenty-four male Kunming mice were randomized into 3 groups for normal feeding (control, n=8) or high-fat diet feeding for 1 week to induce NAFLD, after which the latter mice were given DWYG decoction (treatment group, n=8) or normal saline (model group, n=8) by gavage for 4 weeks. After the last treatment, blood samples were collected from the mice for testing serum TC, HDL-C, LDL-C, ALT and AST levels and isolating circulating exosomes. Using multivariate statistical analysis based on targeted metabolomics strategy, the potential biomarkers for Lyso-GPLs in the exosomes were screened. The isolated exosomes about 100 nm in size had a typical saucer-like structure with distinct double-layer membranes and a mean particle size of 137.5 nm and expressed the specific surface marker proteins CD9, CD63 and TSG101. The mouse models of NAFLD had significantly increased serum levels of TC, HDL-C, LDL-C and AST and lowered serum ALT level. A total of 43 Lyso-GPLs with significant reduction after DWYG Decoction treatment were identified in NAFLD mice. DWYG Decoction can regulate Lyso-GPLs in circulating exosomes in NAFLD mice, which provides a new clue for studying the therapeutic mechanism of DWYG Decoction for liver disease.

Cytosolic N-terminal formyl-methionine deformylation derives cancer stem cell features and tumor progression

Eukaryotic cells can synthesize formyl-methionine (fMet)-containing proteins not only in mitochondria but also in the cytosol to some extent. Our previous study revealed substantial upregulation of N-terminal (Nt)-fMet-containing proteins in the cytosol of SW480 colorectal cancer cells. However, the functional and pathophysiological implications remain unclear. Here, we demonstrated that removal of the Nt-formyl moiety of Nt-fMet-containing proteins (via expressing Escherichia coli PDF peptide deformylase) resulted in a dramatic increase in the proliferation of SW480 colorectal cancer cells. This proliferation coincided with the acquisition of cancer stem cell features, including reduced cell size, enhanced self-renewal capacity, and elevated levels of the cancer stem cell surface marker CD24 and pluripotent transcription factor SOX2. Furthermore, deformylation of Nt-fMet-containing proteins promoted the tumorigenicity of SW480 colorectal cancer cells in an in vivo xenograft mouse model. Taken together, these findings suggest that cytosolic deformylation has a tumor-enhancing effect, highlighting its therapeutic potential for cancer treatment.

Decellularized leaf-based biomaterial supports osteogenic differentiation of dental pulp mesenchymal stem cells.

Decellularized tissues are an attractive scaffolds for 3D tissue engineering. Decellularized animal tissues have certain limitations such as the availability of tissue, high costs and ethical concerns related to the use of animal sources. Plant-based tissue decellularized scaffolds could be a better option to overcome the problem. The leaves of different plants offer a unique opportunity for the development of tissue-specific scaffolds, depending on the reticulate or parallel veination. Herein, we decellularized spinach leaves and employed thesefor the propagation and osteogenic differentiation of dental pulp stem cells (DPSCs). DPSCs were characterized by using mesenchymal stem cell surface markers CD90, CD105 and CD73 and CD34, CD45 and HLA-DR using flow cytometry. Spinach leaves were decellularized using ethanol, NaOH and HCL. Cytotoxicity of spinach leaf scaffolds were analysed by MTT assay. Decellularized spinach leaves supported dental pulp stem cell adhesion, proliferation and osteogenic differentiation. Our data demonstrate that the decellularized spinach cellulose scaffolds can stimulate the growth, proliferation and osteogenic differentiation of DPSCs. In this study, we showed the versatile nature of decellularized plant leaves as a biological scaffold and their potential for bone regeneration in vitro.

BMSC-derived exosomes attenuate persistent corneal epithelial injury by affecting retinal neural-like cells

Persistent corneal epithelial defect (PED) is a challenge to human which is difficultly cured, normally requiring long-term follow-up. Herein, this study explored the potential role of bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) in persistent corneal epithelial injury and the underlying mechanism. After characterization of BMSC-exos, RGC-5 cell viability was determined and surface markers of BMSCs were analyzed. Additionally, RT-qPCR and Western blot measured miR-150-5p, Brn3, Islet-1, and PCNA expression. Dual luciferase assays were conducted to evaluate the targeting relationship between long non-coding Ribonucleic Acid (lncRNA) MIAT and miR-150-5p. Presented in ellipsoidal or cup shape, BMSC-exos were positive to BMSC-specific markers CD29 and CD90, and cell surface markers CD9 and CD63 were detected on exosomes. Importantly, treatment with BMSC-exos significantly promoted proliferation of retinal ganglion cells (RGCs) and hindered cell differentiation. Interestingly, down-regulating lncRNA MIAT exerted the same effect as BMSC-exos, increasing cell viability and decreasing the expression of differentiation-related proteins Brn3 and ISL1. Bioinformatics software predicted miR-150-5P as target of lncRNA MIAT, and the relative luciferase activity of miR-150-5P+MIAT-WT co-transfection group was lower. Conclusively, BMSC-exos can improve PED by targeting and regulating miR-150-5p expression through lncRNA MIAT, which can up-regulate PCNA in RGC-5 cells and down-regulate Brn3 and ISL1.

Preliminary study on the mechanism by which exosomes derived from human exfoliated deciduous teeth improve the proliferation and osteogenic inhibitory effect of glucocorticoid-induced BMSCs

BackgroundSteroid-induced osteonecrosis of the femoral head (SONFH) is a disease characterized by a collapsed femoral head caused by the overuse of glucocorticoids. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) is an important pathological feature of SONFH. In this study, we investigated whether exosomes from SHEDs (stem cells from human exfoliated deciduous teeth) have a therapeutic effect on glucocorticoid-induced inhibition of proliferation and osteogenesis in BMSCs, and elucidated the underlying mechanisms involved. MethodsPrimary dental pulp cells were isolated and cultured from human deciduous tooth pulp, SHEDs were isolated and purified by the limiting dilution method and exosomes were isolated from the supernatants of SHEDs by ultracentrifugation. The cell surface markers CD31, CD34, CD45, CD73, CD90 and CD105 were detected by flow cytometry. A Cell-Counting-Kit-8 assay was used to detect cell activity. ALP and Alizarin Red staining were used to identify osteogenic differentiation ability, and exosomes were identified using transmission electron microscopy, NanoFCM and Western blotting. PKH67 fluorescence was used to track the uptake of exosomes by BMSCs. Transcriptome analysis combined with quantitative real-time PCR was used to explore the underlying mechanism involved. ResultsExosomes secreted by SHEDs can be endocytosed by BMSCs, and can partially reverse the inhibitory effects of glucocorticoids on the viability and osteogenic differentiation of BMSCs. Transcriptome sequencing analysis revealed that the differentially expressed mRNAs regulated by SHED-derived exosomes were enriched mainly in signaling pathways such as the apoptosis pathway, the PI3K-Akt signaling pathway, the Hippo signaling pathway and the p53 signaling pathway. qPCR showed that SHED-derived exosomes reversed the dexamethasone-induced upregulation of HGF and ITGB8 expression and the inhibition of EFNA1 expression, but further increased the dexamethasone-induced downregulation of IL7 expression. In conclusion, SHED-derived exosomes partially reversed the inhibitory effects of glucocorticoids on BMSC proliferation and osteogenesis by inhibiting the expression of HGF, ITGB8 and IL7, and upregulating the expression of EFNA1.

Human Cord Blood Endothelial Progenitor Cells and Pregnancy Complications (Preeclampsia, Gestational Diabetes Mellitus, and Fetal Growth Restriction).

Hemangioblasts give rise to endothelial progenitor cells (EPCs), which also express the cell surface markers CD133 and c-kit. They may differentiate into the outgrowth endothelial cells (OECs) that control neovascularization in the developing embryo. According to numerous studies, reduced levels of EPCs in circulation have been linked to human cardiovascular disorders. Furthermore, preeclampsia and senescence have been linked to levels of EPCs produced from cord blood. Uncertainties surround how preeclampsia affects the way EPCs function. It is reasonable to speculate that preeclampsia may have an impact on the function of fetal EPCs during the in utero period; however, the present literature suggests that maternal vasculopathies, including preeclampsia, damage fetal circulation. Additionally, the differentiation potential and general activity of EPCs may serve as an indicator of the health of the fetal vascular system as they promote neovascularization and repair during pregnancy. Thus, the purpose of this review is to compare-through the assessment of their quantity, differentiation potency, angiogenic activity, and senescence-the angiogenic function of fetal EPCs obtained from cord blood for normal and pregnancy problems (preeclampsia, gestational diabetes mellitus, and fetal growth restriction). This will shed light on the relationship between the angiogenic function of fetal EPCs and pregnancy complications, which could have an effect on the management of long-term health issues like metabolic and cardiovascular disorders in offspring with abnormal vasculature development.

The biological characteristics of chicken embryo mesenchymal stem cells isolated from chorioallantoic membrane.

Mesenchymal stem cells (MSCs) derived from fetal membranes (FMs) have the potential to exhibit immunosuppression, improve blood flow, and increase capillary density during transplantation. In the field of medicine, opening up new avenues for disease treatment. Chicken embryo chorioallantoic membrane (CAM), as an important component of avian species FM structure, has become a stable tissue engineering material in vivo angiogenesis, drug delivery, and toxicology studies. Although it has been confirmed that chorionic mesenchymal stem cells (Ch-MSCs) can be isolated from the outer chorionic layer of FM, little is known about the biological characteristics of MSCs derived from chorionic mesodermal matrix of chicken embryos. Therefore, we evaluated the characteristics of MSCs isolated from chorionic tissues of chicken embryos, including cell proliferation ability, stem cell surface antigen, genetic stability, and in vitro differentiation potential. Ch-MSCs exhibited a broad spindle shaped appearance and could stably maintain diploid karyotype proliferation to passage 15 in vitro. Spindle cells were positive for multifunctional markers of MSCs (CD29, CD44, CD73, CD90, CD105, CD166, OCT4, and NANOG), while hematopoietic cell surface marker CD34, panleukocyte marker CD45, and epithelial cell marker CK19 were negative. In addition, chicken Ch-MSC was induced to differentiate into four types of mesodermal cells in vitro, including osteoblasts, chondrocytes, adipocytes, and myoblasts. Therefore, the differentiation potential of chicken Ch-MSC in vitro may have great potential in tissue engineering. In conclusion, chicken Ch-MSCs may be an excellent model cell for stem cell regenerative medicine and chorionic tissue engineering.

Abstract 11: Development of innovative off-the-shelf cancer immunotherapies with iPSC-derived CD8-positive T-cells

Abstract Chimeric antigen receptor (CAR) based T-cell immunotherapies have transformed the oncology landscape and evolved as part of the standard of care for several hematological malignancies. To generate CAR-T-cell products, autologous patient-derived αβT-cells are engineered with a CAR for tumor cell targeting. However, generating autologous T-cell products fails in a significant number of cases due to the poor quality and quantity of blood-derived T-cells and is associated with manufacturing and logistical complexity as well as high product costs. Therefore, it is crucial to develop strategies for off-the-shelf T-cell products as otherwise many patients are left without this treatment option. Manufacturing allogeneic T-cells from induced pluripotent stem cells (iPSCs) has a great potential to generate cell products with consistently high quality and scalable quantities. In addition, high fidelity gene-editing can be performed in iPSCs to address tumor resistance mechanisms and to prevent exhaustion of the T-cells. We have established a feeder-free differentiation protocol that enables robust production of iPSC-derived αβT-cells (iαβT). Flow cytometry and single cell transcriptome analysis ensure stringent monitoring of all process stages. To demonstrate functional activity of iαβT, cytotoxicity and cytokine release assays were performed. We compared the differentiation potential of iPSC lines derived from T-cells (t-iPSCs) to a hematopoietic stem cell-derived iPSC line with an αβTCR knock-in. Hematopoietic progenitor cells were induced from the different iPSC lines and differentiated into iαβT. During the differentiation process, surface markers CD45, CD5 and CD7 were displayed, and cells started to express αβTCRs. Importantly, iαβT derived from the different iPSC lines expressed CD8α and CD8β which is crucial for the function of cytotoxic T-cells. The CD4/CD8 double positive stage is an important step in T-cell development and was observed only when T-cells were generated from t-iPSC, but not from the TCR knock-in cells. Functional analysis of iαβT-cells confirmed their cytotoxic activity and potential to release cytokines after activation. Our scalable process for iαβT differentiation generates CD8-positive T-cells that secrete cytokines and show cytotoxic activity against tumor cells, demonstrating their potential as a promising cell source for TCR-T or CAR-T cancer immunotherapies. Citation Format: Riga Tawo, Michela Mirenda, Olivia Cypris, Philip Hublitz, Nadja Wagner, Michael Epstein, Michael Esquerre, Audrey Holtzinger, Monika Braun, Markus Dangl, Rodrigo Grandy, Daniel Sommermeyer. Development of innovative off-the-shelf cancer immunotherapies with iPSC-derived CD8-positive T-cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 11.

Abstract 122: Fusobacterium nucleatum in saliva of oral cancer patients induces tumor stemness defense phenotype in cancer stem cells

Abstract Background: Oral squamous cell carcinoma (OSCC) is a highly aggressive cancer. Cancer Stem Cells (CSCs) having cell surface markers CD44, ALDH, and EpCAM+ have been identified in OSCC. However, the host pathogen interaction between CSCs and oral microbiome has not yet been studied. A number of studies have recently demonstrated the presence of specific oral bacteria populations and their lipopolysaccharides (LPS) in the tumor microenvironment (1). We previously reported pathogenic bacterial internalization in the CSCs (2). Based on the findings, we have developed an in-vitro model to investigate how oral microbiota may integrate into the tumor microenvironment's CSC population and control its activity. Here, we investigated the host/pathogen interaction between CSCs and FN. Methods: Oral bacteria FN was selectively isolated using FEA agar plates from oral saliva of oral cancer patients (n=10) at stage 3 or 4. The isolated bacteria was co cultured with SCC 25 cells at MOI of 1:50. After co culturing the stemness genes such as SOX 2, OCT 4, Nanog,LPS and ABCG2+ cancer stem cell markers were analysed. ABCG2+ CSCs and ABCG2- cells were immunomagnetically sorted and lysed followed by RNA extraction and RT QPCR was performed to observe if FN has selectively internalised in the CSCs. Also ABCG2+ and ABCG 2- cells were used to perform clonogenic assay. Results: Coculture of FN with SCC 25 cell line induced high expression of stemness genes SOX, OCT 4 and Nanog along with CSC markers ABCG2+. Moreover high expression of LPS was observed indicating the presence of FN in the coculture. Importantly live bacteria was found internalized in ABCG2+ cells but not in ABCG2- cells. High clonogenicity was observed in ABCG2+ CSCs compared to ABCG2- cells. Notably, we found that live bacteria and their LPS, mostly Fusobacterium nucleatum isolated (FN) from clinical subjects, were capable of invading CSCs in the in-vitro setting. Post the host-pathogen interaction; it enabled the activation of a niche modulatory tumor stemness defense (TSD) phenotype in the CSCs. These aggressive CSCs with the TSD phenotype have been found to have a critical role in the progression and relapse of oral cancer. Conclusion: Expression of stemness genes infers the niche defence mechanism of the CSCs of the tumour microenvironment due to infection of FN. Importantly presence of live bacteria in ABCG2+ CSCs indicates that FN selectively infects ABCG2+ CSCs but not ABCG2- cells. High clonogenicity of ABCG2+ CSCs confirms the TSD phenotypic attributes of the CSCs.

Alginate hydrogel-PCL/gelatin nanofibers composite scaffold containing mesenchymal stem cells-derived exosomes sustain release for regeneration of tympanic membrane perforation

Exosomes are among the most effective therapeutic tools for tissue engineering. This study demonstrates that a 3D composite scaffold containing exosomes can promote regeneration in rat tympanic membrane perforation (TMP). The scaffolds were characterized using scanning electron microscopy (SEM), degradation, PBS adsorption, swelling, porosity, and mechanical properties. To confirm the isolation of exosomes from human adipose-derived mesenchymal stem cells (hAMSCs), western blot, SEM, and dynamic light scattering (DLS) were performed. The Western blot test confirmed the presence of exosomal surface markers CD9, CD81, and CD63. The SEM test revealed that the isolated exosomes had a spherical shape, while the DLS test indicated an average diameter of 82.5 nm for these spherical particles. MTT assays were conducted to optimize the concentration of hAMSCs-exosomes in the hydrogel layer of the composite. Exosomes were extracted on days 3 and 7 from an alginate hydrogel containing 100 and 200 μg/mL of exosomes, with 100 μg/mL identified as the optimal value. The optimized composite scaffold demonstrated improved growth and migration of fibroblast cells. Animal studies showed complete tympanic membrane regeneration (TM) after five days. These results illustrate that a scaffold containing hAMSC-exosomes can serve as an appropriate tissue-engineered scaffold for enhancing TM regeneration.

Astragali Radix-Curcumae Rhizoma inhibits colon cancer progression and enhances 5-FU efficacy by regulating hypoxia-inducible factors and tumor stem cells

The animal and cell models were used in this study to investigate the mechanism of Astragali Radix-Curcumae Rhizoma(HQEZ) in inhibiting colon cancer progression and enhancing the efficacy of 5-fluorouracil(5-FU) by regulating hypoxia-inducible factors and tumor stem cells. The animal model was established by subcutaneous transplantation of colon cancer HCT116 cells in nude mice, and 24 successfully modeled mice were randomized into model, 5-FU, HQEZ, and 5-FU+HQEZ groups. The tumor volume was measured every two days. Western blot was employed to measure the protein levels of epidermal growth factor receptor(EGFR), dihydropyrimidine dehydrogenase(DPYD), and thymidylate synthase(TYMS), the key targets of the hypoxic core region, as well as the hypoxia-inducible factors HIF-1α and HIF-2α and the cancer stem cell surface marker CD133 and SRY-box transcription factor 2(SOX2). The results of animal experiments showed that HQEZ slowed down the tumor growth and significantly increased the tumor inhibition rate of 5-FU. Compared with the model group, HQEZ significantly down-regulated the protein levels of EGFR and DPYD, and 5-FU+HQEZ significantly down-regulated the protein levels of EGFR and TYMS in tumors. Compared with the model group, HQEZ significantly down-regulated the protein levels of HIF-1α, HIF-2α, SOX2, and CD133 in the hypoxic core region. Compared with the 5-FU group, 5-FU+HQEZ lowered the protein levels of HIF-1α, HIF-2α, and SOX2. The cell experiments showed that the protein le-vels of HIF-1α and HIF-2α in HCT116 cells elevated significantly after low oxygen treatment. Compared with 5-FU(1.38 μmol·L~(-1)) alone, HQEZ(40 mg·mL~(-1)) and 5-FU+HQEZ significantly down-regulated the protein levels of HIF-1α, HIF-2α, and TYMS. In conclusion, HQEZ can inhibit the expression of hypoxia-responsive molecules in colon cancer cells and reduce the properties of cancer stem cells, thereby enhancing the therapeutic effect of 5-FU on colon cancer.

Differentiation Potential Analysis of Bone Marrow Mesenchymal Stem Cells from Guizhou Miniature Pigs

In this study, different growth characteristics of hematopoietic stem cells and bone marrow mesenchymal stem cells were used to isolate and culture BMSCs by whole bone marrow adhesion method, and RT-PCR was used to detect cell surface markers CD29, CD31, CD34, CD44, CD71, CD73, CD90. The differentiation of osteocytes into adipocytes and osteoblasts was induced in vitro, and the differentiation ability was observed by staining with oil red O and rubinin. To investigate the isolation and culture methods of BMSCs from Guizhou miniature pigs (Sussa lvanius) in vitro, and to study their biological characteristics and potential for multi-differentiation. The results showed that a small number of adherent cells could be seen in the primary BMSCs cultured in vitro within 48 hours, and the confluent cells reached 90% in 5~6 days. The cell growth state was good, and the shape was spindle and polygonal. RT-PCR was used to detect the positive expression of CD29, CD44, CD71, CD73 and CD90 on the cell surface, and the negative expression of CD31 and CD34. Oil red O staining showed the formation of lipid droplets in the cells, and alizarine red staining showed calcium nodules in the cells, indicating that the cells isolated and cultured in this experiment had the ability of multidirection differentiation. It is consistent with the characteristics of BMSCs. The growth of BMSCs cultured in vitro was stable, and the expanded BMSCs had multidirectional differentiation potential, which was an ideal seed cell for tissue engineering.

Deer antler stem cells immortalization by modulation of hTERT and the small extracellular vesicles characters.

Deer antler stem cells (AnSCs) exhibit properties of both embryonic and mesenchymal stem cells, with superior self-renewal and proliferation, which drive rapid antler growth and regeneration. AnSCs and their derived small extracellular vesicles (sEVs) hold promising potential for applications in regeneration medicine. Due to the restricted proliferative capacity inherent in primary cells, the production capacity of AnSCs and their sEVs are limited. Human telomerase reverse transcriptase (hTERT) is the most important telomerase subunit, hTERT gene insertion has been successfully employed in generating immortalized cell lines. In this study, we successfully established immortalized AnSCs by transducing the hTERT gene using lentivirus. Compared to primary AnSCs, hTERT-AnSCs demonstrated extended passage potential and accelerated proliferation rates while maintaining the mesenchymal stem cell surface markers CD44 and CD90. Additionally, hTERT-AnSCs retained the capacity for osteogenic, adipogenic, and chondrogenic differentiation. sEVs derived from hTERT-AnSCs exhibited a particle size distribution similar to that of AnSCs, both displaying a cup-shaped morphology and expressing CD81, ALIX, and TSG101, while notably lacking GM130 expression. We successfully isolated primary stem cells from deer antler and established the immortalized hTERT-AnSCs. Remarkably, this cell line maintains its stem cell characteristics even after 40 passages. The sEVs derived from these cells exhibit identical morphological and structural features to those of primary AnSCs. This research provides essential technical support for the application of AnSCs and their sEVs in regenerative medicine.

Effect of Exosomes From Bone Marrow-Derived Mesenchymal Stromal Cells and Adipose-Derived Stromal Cells on Bone-Tendon Healing in a Murine Rotator Cuff Injury Model.

Bone-tendon injury is characterized by poor self-healing. It is established that exosomes are favorable for tissue repair and regeneration. However, their effect on bone-tendon healing has not yet been determined. To compare the effectiveness of exosomes derived from adipose-derived mesenchymal stromal cells (ADSC-Exos) and bone marrow-derived mesenchymal stromal cells (BMSC-Exos) on bone-tendon interface healing in murine rotator cuff injury model and explore the underlying mechanisms thereof. Controlled laboratory study. A total of 63 male C57BL6 mice with rotator cuff injuries underwent surgery and were randomly assigned to a control group treated without exosomes (n = 21), an ADSC-Exos group (n = 21), or a BMSC-Exos group (n = 21). The mice were sacrificed 4 or 8 weeks after surgery, and tissues were collected for histologic examination and radiographic and biomechanical testing. For exosome tracing in vivo, mice were sacrificed 7 days after surgery. A series of functional assays (radiographic evaluation, proliferation assay, Alizarin Red staining, alkaline phosphatase staining and activity, Alcian blue staining, quantitative polymerase chain reaction analyses, and glycosaminoglycans quantification) were conducted to evaluate the effect of exosomes on the cellular behaviors of the BMSCs in vitro. A statistical analysis of multiple-group comparisons was performed by 1-way analysis of variance, followed by the Bonferroni post hoc test to assess the differences between the 2 groups. The ADSCs and BMSCs were positive for surface markers CD29 and CD90 and negative for surface markers CD34 and CD45 and could differentiate into osteoblasts, chondrocytes, and adipocytes. Exosomes showed a cup- or sphere-shaped morphology and were positive for CD63 and TGS101. Local injection of ADSC-Exos and BMSC-Exos could recruit BMSCs and promote osteogenesis, chondrogenesis, and bone-tendon healing. In vitro, ADSC-Exos and BMSC-Exos could significantly promote the proliferation, migration, osteogenic differentiation, and chondrogenic differentiation ability of BMSCs. In vivo, ADSC-Exos and BMSC-Exos significantly accelerated bone-tendon injury healing, with no significant statistical difference between them. ADSC-Exos and BMSC-Exos exhibited similar therapeutic effects on bone-tendon healing in our murine animal model. ADSC-Exos and BMSC-Exos may be used to develop a new cell-free therapy method for promoting rotator cuff injury repair.

Tobacco exposure, but not aging, shifts the frequency of peripheral blood B cell subpopulations.

Several disturbances in T-cell mediated immunity have been described during aging, but immunosenescence of the B-cell compartment is less well elucidated. The peripheral blood B-cell compartment (CD19+) can be split into six main subpopulations according to the cell surface markers IgD, CD27, CD24, and CD38: Transitional, naïve, unswitched, switched, double negative and plasmablasts. We thus aimed to verify whether shifts in these subsets occur during healthy and pathological aging. We recruited three groups of aged people (> 60 years old), healthy, COPD patients, and smokers without altered pulmonary function test, and a fourth group of individuals 18-40 years old (youngs). Total B-cells percentage and absolute number were similar among the healthy aged, COPD patients, and youngs, but the smokers showed significantly higher absolute numbers. While all six B-cell subset percentages were comparable among the healthy aged, COPD patients, and youngs, smokers showed significantly higher percentages of switched B-cells and reduced naïve B-cells than the other three groups, resulting in an inverted naive:switched ratio. Analysis of the cell subset absolute numbers showed a similar trend. Overall, our results suggest that aging drives milder alterations in the distribution of peripheral blood B-cell subpopulations than in the T-cell compartment. We suggest that it is the T-cell immunosenescence that most contributes to the poor humoral immune responses in the elderly, vaccine responses included. Surprisingly it was the smokers who showed significant alterations when compared with the youngs, healthy aged, and aged COPD patients, probably as a result of the chronic immune stimulation described in active smoking subjects.

A novel approach for transforming breast cancer stem cells into endothelial cells.

Tumor vascular endothelial cells play a pivotal in the tumor microenvironment, influencing the proliferation, invasion, and metastasis of tumor progression. The present study investigated a novel method for inducing the transformation of breast cancer stem cells into endothelial cells, providing a cellular model investigating anti-angiogenic mechanisms in vitro. The breast cancer cell line MCF-7 was used, and the expression of CD133 was initially detected using flow cytometry. CD133+ breast cancer cells were purified using immunomagnetic bead sorting technology, yielding an MCF-7CD133+ subpopulation. The proliferation ability of these cells was assessed using an MTT assay, while their microsphere formation ability was evaluated using a microsphere formation assay. Post-transformation in an optimized endothelial cell culture medium, expression of endothelial cell markers CD31 and CD105 were detected using flow cytometry. Endothelial cell tube formation assays and DiI-labeled acetylated low-density lipoprotein (DiI-Ac-LDL) assays were employed to analyze the endothelial cell function of the MCF-7CD133+ cells. MDM2/CEN12 gene amplification was detected through fluorescence in situ hybridization (FISH). The MCF-7 breast cancer cell line exhibited 1.7±0.3% trace cells expressing the stem cell surface marker CD133. After anti-CD133 immunomagnetic bead sorting, MCF-7CD133+ and MCF-7CD133- subpopulation cells were obtained, with CD133 expression rates of 85.6±2.8 and 0.18±0.08%, respectively. MTT assay results demonstrated that, after 7 days, the proliferation rate of MCF-7CD133+ cells was significantly higher compared with MCF-7CD133- cells. MCF-7CD133+ subpopulation cells displayed strong stem cell characteristics, growing in suspension in serum-free media and forming tumor cell spheres. In contrast, MCF-7CD133- cells failed to form microspheres. After culturing cells in endothelial cell differentiation and maintenance media, the percentage of MCF-7CD133+ cells before and after endothelial cell culture was 0.3±0.16 and 81.4±8.37% for CD31+ cells and 0.2±0.08 and 83.8±7.24% for CD105+ cells, respectively. Vascular-like structure formation and Ac-LDL phagocytosis with red fluorescence in the tube formation assays confirmed endothelial cell function in the MCF-7CD133+ cells. FISH was used to verify MDM2/CEN12 gene amplification in the induced MCF-7CD133+ cells, indicating tumor cell characteristics. The modified endothelial cell transformation medium effectively induced differentiated tumor stem cells to express vascular endothelial cell markers and exhibit endothelial functions, ideal for in vitro anti-angiogenesis research.

Hydrogel loaded with exosomes from Wharton's Jelly-derived mesenchymal stem cells enhances wound healing in mice.

To explore the effect of hydrogel loaded with exosomes from Wharton's Jelly-derived mesenchymal stem cell (WJMSC) on wound healing. Exosomes were extracted from WJMSC, and the morphology and size of WJMSC-derived exosomes (WEX) were analyzed by transmission electron microscopy and nanoparticle size analyzer, respectively. The surface markers CD9, CD81, and Calnexin of WEX were detected by Western blotting. Exosome-loaded alginate hydrogel (WEX-gel) was prepared; its morphology was studied by scanning electron microscope, and its rheological behavior was examined by a rheometer. The in vitro drug release performance of WEX-gel was investigated by BCA method. RAW264.7 cells were treated with alginate hydrogel, WEX and WEX-gel, respectively; and the expression of CD86 and CD206 in macrophages was detected by flow cytometry. A full-thickness skin wound model was established in mice; the model mice were randomly divided into blank control group, WEX control group and WEX-gel group, and PBS, WEX and WEX-gel were applied to the wound area of mice, respectively. On day 3, the skin tissue of mice was excised, and the antibacterial effect of WEX hydrogel was evaluated by plate counting. On day 15, the mice were euthanized and the percentage of residual wounds was calculated. The histological changes of the skin wound were observed after hematoxylin and eosin (HE) and Masson stainings. The expression of CD86, CD206, CD31 and vascular endothelial growth factor (VEGF) in the skin wound tissue was detected by immunohistochemistry. Exosomes were successfully extracted from WJMSC. WEX-gel presented a regular three-dimensional network structure, good rheology and controlled drug release performance. WEX-gel promoted the polarization of RAW264.7 cells from the M1 phenotype to M2 phenotype in vitro. The residual wound percentage in blank control group, WEX control group and WEX-gel group were (27.5±3.4)%, (15.3±1.2)% and (7.6±1.1)%, respectively (P<0.05). The antibacterial property of WEX-gel is better than that of WEX (P<0.05). The dermis thickness, the number of new hair follicles, and the rate of collagen deposition in the WEX-gel group were significantly higher than those in the other two groups (all P<0.05). The expression of CD206, CD31 and VEGF in skin wound tissue was higher and the expression of CD86 was lower in WEX-gel group than those in other two groups (all P<0.05). WEX-gel can significantly promote wound healing in mice by regulating the polarization of macrophages.