Cyclic stretch enhances neutrophil extracellular trap formation.

BACKGROUND: Neutrophils, the most abundant leukocytes circulating in blood, contribute to host defense and play a significant role in chronic inflammatory disorders. They can release their DNA in the form of extracellular traps (NETs), which serve as scaffolds for capturing bacteria and various blood cells. However, uncontrolled formation of NETs (NETosis) can lead to excessive activation of coagulation pathways and thrombosis. Once neutrophils are migrated to infected or injured tissues, they become exposed to mechanical forces from their surrounding environment. However, the impact of transient changes in tissue mechanics due to the natural process of aging, infection, tissue injury, and cancer on neutrophils remains unknown. To address this gap, we explored the interactive effects of changes in substrate stiffness and cyclic stretch on NETosis. Primary neutrophils were cultured on a silicon-based substrate with stiffness levels of 30 and 300 kPa for at least 3 h under static conditions or cyclic stretch levels of 5% and 10%, mirroring the biomechanics of aged and young arteries. RESULTS: Using this approach, we found that neutrophils are sensitive to cyclic stretch and that increases in stretch intensity and substrate stiffness enhance nuclei decondensation and histone H3 citrullination (CitH3). In addition, stretch intensity and substrate stiffness promote the response of neutrophils to the NET-inducing agents phorbol 12-myristate 13-acetate (PMA), adenosine triphosphate (ATP), and lipopolysaccharides (LPS). Stretch-induced activation of neutrophils was dependent on calpain activity, the phosphatidylinositol 3-kinase (PI3K)/focal adhesion kinase (FAK) signalling and actin polymerization. CONCLUSIONS: In summary, these results demonstrate that the mechanical forces originating from the surrounding tissue influence NETosis, an important neutrophil function, and thus identify a potential novel therapeutic target.

Identification and characterisation of maternal perivascular SUSD2+ placental mesenchymal stem/stromal cells.

Mesenchymal stem cells (MSCs) that meet the International Society for Cellular Therapy (ISCT) criteria are obtained from placental tissue by plastic adherence. Historically, no known single marker was available for isolating placental MSCs (pMSCs) from the decidua basalis. As the decidua basalis is derived from the regenerative endometrium, we hypothesised that SUSD2, an endometrial perivascular MSC marker, would purify maternal perivascular pMSC. Perivascular pMSCs were isolated from the maternal placenta using SUSD2 magnetic bead sorting and assessed for the colony-forming unit-fibroblasts (CFU-F), surface markers, and in vitro differentiation into mesodermal lineages. Multi-colour immunofluorescence was used to colocalise SUSD2 and α-SMA, a perivascular marker in the decidua basalis. Placental stromal cell suspensions comprised 5.1%SUSD2+ cells. SUSD2 magnetic bead sorting of the placental stromal cells increased their purity approximately two-fold. SUSD2+ pMSCs displayed greater CFU-F activity than SUSD2- stromal fibroblasts (pSFs). However, both SUSD2+ pMSC and SUSD2- pSF underwent mesodermal differentiation in vitro, and both expressed the ISCT surface markers. Higher percentages of cultured SUSD2+ pMSCs expressed the perivascular markers CD146, CD140b, and SUSD2 than SUSD2- pSFs. These findings suggest that SUSD2 is a single marker that enriches maternal pMSCs, suggesting they may originate from eMSC. Placental decidua basalis can be used as an alternative source of MSC for clinical translation in situations where there is no access to endometrial tissue.

Correction to: "Comparative repair capacity of knee osteochondral defects using regenerated silk fiber scaffolds and fibrin glue with/without autologous chondrocyes during 36 weeks in rabbit model.

The published online of the original version contains mistakes.

Comparative repair capacity of knee osteochondral defects using regenerated silk fiber scaffolds and fibrin glue with/without autologous chondrocytes during 36 weeks in rabbit model.

The reconstruction capability of osteochondral (OCD) defects using silk-based scaffolds has been demonstrated in a few studies. However, improvement in the mechanical properties of natural scaffolds is still challengeable. Here, we investigate the in vivo repair capacity of OCD defects using a novel Bombyx mori silk-based composite scaffold with great mechanical properties and porosity during 36 weeks. After evaluation of the in vivo biocompatibility and degradation rate of these scaffolds, we examined the effectiveness of these fabricated scaffolds accompanied with/without autologous chondrocytes in the repair of OCD lesions of rabbit knees after 12 and 36 weeks. Moreover, the efficiency of these scaffolds was compared with fibrin glue (FG) as a natural carrier of chondrocytes using parallel clinical, histopathological and mechanical examinations. The data on subcutaneous implantation in mice showed that the designed scaffolds have a suitable in vivo degradation rate and regenerative capacity. The repair ability of chondrocyte-seeded scaffolds was typically higher than the scaffolds alone. After 36 weeks of implantation, most parts of the defects reconstructed by chondrocytes-seeded silk scaffolds (SFC) were hyaline-like cartilage. However, spontaneous healing and filling with a scaffold alone did not eventuate in typical repair. We could not find significant differences between quantitative histopathological and mechanical data of SFC and FGC. The fabricated constructs consisting of regenerated silk fiber scaffolds and chondrocytes are safe and suitable for in vivo repair of OCD defects and promising for future clinical trial studies.

Differentiation potential of menstrual blood- versus bone marrow-stem cells into glial-like cells.

Menstrual blood is easily accessible, renewable, and inexpensive source of stem cells that have been interested for cell therapy of neurodegenerative diseases. In this study, we showed conversion of menstrual blood stem cells (MenSCs) into clonogenic neurosphere- like cells (NSCs), which can be differentiated into glial-like cells. Moreover, differentiation potential of MenSCs into glial lineage was compared with bone marrow stem cells (BMSCs). Differentiation potential of individual converted NSCs derived from MenSCs or BMSCs into glial-like cells was investigated using immunofluorescence staining and real-time polymerase chain reaction.The fibroblastic morphology of both MenSCs and BMSCs was turned into NSCs shape during first step of differentiation. NSCs derived from both BMSCs and MenSCs expressed higher levels of Olig-2 and Nestin markers compared to undifferentiated cells. The expression levels of myelin basic protein (MBP) mRNA up regulated only in BMSCs-NSCs no in MenSCs-NSCs. However, outgrowth of individual NSCs derived from both MenSCs and BMSCs into glial-like cells led to significant up regulation of glial fibrillary acidic protein,Olig-2 and MBP at mRNA and protein level accompanied with down regulation of Nestin protein.This is the first study demonstrating that MenSCs can be converted to NSCs with differentiation ability into glial-like cells. Accumulative data show different expression pattern of glial markers in differentiated MenSCs compared to BMSCs. The comparable differentiation potential, more accessibility and no invasive technique for sample collection of MenSCs in comparison with BMSCs introduce MenSCs as an apt, consistent and safe alternative to BMSCs for cell therapy of neurodegenerative diseases.

Piezo1 expression in neutrophils regulates shear-induced NETosis.

Neutrophil infiltration and subsequent extracellular trap formation (NETosis) is a contributing factor in sterile inflammation. Furthermore, neutrophil extracellular traps (NETs) are prothrombotic, as they provide a scaffold for platelets and red blood cells to attach to. In circulation, neutrophils are constantly exposed to hemodynamic forces such as shear stress, which in turn regulates many of their biological functions such as crawling and NETosis. However, the mechanisms that mediate mechanotransduction in neutrophils are not fully understood. In this study, we demonstrate that shear stress induces NETosis, dependent on the shear stress level, and increases the sensitivity of neutrophils to NETosis-inducing agents such as adenosine triphosphate and lipopolysaccharides. Furthermore, shear stress increases intracellular calcium levels in neutrophils and this process is mediated by the mechanosensitive ion channel Piezo1. Activation of Piezo1 in response to shear stress mediates calpain activity and cytoskeleton remodeling, which consequently induces NETosis. Thus, activation of Piezo1 in response to shear stress leads to a stepwise sequence of cellular events that mediates NETosis and thereby places neutrophils at the centre of localized inflammation and prothrombotic effects.

Literature review on hepatoprotective effects of diosgenin: possible mechanisms of action.

Liver diseases are among the major causes of death worldwide. Alcohol consumption, obesity, diabetes mellitus, viral infection, and drug-induced liver injury are common risk factors for the development of liver diseases. Diosgenin is a herbal steroidal sapogenin with hepatoprotective properties. This phytosteroid modulates lipid profile and prevents liver injury and fibrosis, metabolic associated fatty liver disease (MAFLD), steatohepatitis, and diabetes mellitus. Different mechanisms have been presented underlying the therapeutic properties of diosgenin. Diosgenin with antioxidant activity and ability to inhibit pro-inflammatory and apoptotic mediators as well as modulating gut microbiota is able to protect the liver. This literature overview summarizes the previously published studies regarding the hepatoprotective function of diosgenin against liver injury in different conditions with an emphasis on possible underlying mechanisms.

Repair of Osteochondral Defects in Rabbit Knee Using Menstrual Blood Stem Cells Encapsulated in Fibrin Glue: A Good Stem Cell Candidate for the Treatment of Osteochondral Defects.

Background: In recent years, researchers discovered that menstrual blood-derived stem cells (MenSCs) have the potential to differentiate into a wide range of tissues including the chondrogenic lineage. In this study, we aimed to investigate the effect of MenSCs encapsulated in fibrin glue (FG) on healing of osteochondral defect in rabbit model. Methods: We examined the effectiveness of MenSCs encapsulated in FG in comparison with FG alone in the repair of osteochondral defect (OCD) lesions of rabbit knees after 12 and 24 weeks. Results: Macroscopical evaluation revealed that the effectiveness of MenSCs incorporation with FG is much higher than FG alone in repair of OCD defects. Indeed, histopathological evaluation of FG + MenSCs group at 12 weeks post-transplantation demonstrated that defects were filled with hyaline cartilage-like tissue with proper integration, high content of glycosaminoglycan and the existence of collagen fibers especially collagen type II, as well as by passing time (24 weeks post-transplantation), the most regenerated tissue in FG + MenSCs group was similar to hyaline cartilage with relatively good infill and integration. As the same with the result of 12 weeks post-implantation, the total point of microscopical examination in FG + MenSCs group was higher than other experimental groups, however, no significant difference was detected between groups at 24 weeks (p > 0.05). Conclusion: In summary, MenSCs as unique stem cell population, is suitable for in vivo repair of OCD defects and promising for the future clinical application.

Current State of Cartilage Tissue Engineering using Nanofibrous Scaffolds and Stem Cells.

Cartilage is an avascular, aneural, and alymphatic connective tissue with a limited capacity caused by low mitotic activity of its resident cells, chondrocytes. Natural repair of full thickness cartilage defects usually leads to the formation of fibrocartilage with lower function and mechanical force compared with the original hyaline cartilage and further deterioration can occur. Tissue engineering and regenerative medicine is a promising strategy to repair bone and articular cartilage defects and rehabilitate joint functions by focusing on the optimal combination of cells, material scaffolds, and signaling molecules. The unique physical and topographical properties of nanofibrous structures allow them to mimic the extracellular matrix of native cartilage, making an appropriate resemblance to induce cartilage tissue regeneration and reconstruction. To improve simulation of native cartilage, the incorporation of nanofibrous scaffolds with suitable corresponsive cells could be effective. In this review article, an attempt was made to present the current state of cartilage tissue engineering using nanofibrous scaffolds and stem cells as high proliferative immune privilege cells with chondrogenic differentiation ability. The comprehensive information was retrieved by search of relevant subject headings in Medline/Pubmed and Elsevier databases.

Exogenous Secreted Frizzled-Related Protein-4 Modulates Steroidogenesis of Rat Granulosa Cells through Wnt/ß-catenin and PI3K/AKT Signaling Pathways.

BACKGROUND: It has been reported that secreted frizzled-related protein-4 known as an antagonist of Wnt signaling pathway plays a role in luteinization process of rodent granulosa cells. The purpose of this study was twofold: 1) to determine whether recombinant human secreted frizzled-related protein-4 (rhSFRP-4) could directly induce terminal differentiation of rat Granulosa Cells (GCs) and 2) to understand how the modulation of ß-catenin and Protein Kinase B (PKB)/AKT activity by exogenous SFRP-4 could be involved in steroidogenesis. METHODS: GCs were firstly stimulated with Follicle-Stimulating Hormone (FSH) named as FSH-primed cells then were treated with luteinizing hormone (LH). Then estradiol (E2) and progesterone (P4) production levels were assessed in the absence or presence of rhSFRP-4 treatment. The expression levels of activated ß-catenin, pAKTser 473 , pGSK3ßser 9 were assessed by western blot or immunofluoresence. RESULTS: In the presence of rhSFRP-4, there was 38% decreased E2 levels compared to untreated FSH-primed cells (p<0.05), and P4 production subsequently decreased. However, in GCs pre-treated with rhSFRP-4 prior to addition of FSH, P4 levels increased 2-fold compared with untreated cells (p<0.05). Unexpectedly, treatment with rhSFRP-4 prior to LH stimulation inhibited LH-induced P4 secretion. Treatment with low (0.5 ng/ml) but not high (50 ng/ml) concentrations of rhSFRP-4 led to significantly increased levels of pGSK3ßser 9 (1.6-fold) and nuclear active ß-catenin (2.8-fold) in GCs compared with untreated cells. Interestingly, pre-treating GCs with rhsFPR4 prior to LH stimulation resulted in a 38% decrease in pAKTser 473 levels compared with those in LH-treated cells (p<0.05). CONCLUSION: Taken together, our results showed that rhSFRP-4 could directly induce terminal differentiation in GCs via the modulation of ß-catenin and PKB/AKT pathways and that it does so in a dose-dependent manner.

Extended Culture of Encapsulated Human Blastocysts in Alginate Hydrogel Containing Decidualized Endometrial Stromal Cells in the Presence of Melatonin.

Extended in vitro culture of human embryos beyond blastocyst stage could serve as a tool to explore the molecular and physiological mechanisms underlying embryo development and to identify factors regulating pregnancy outcomes. This study presents the first report on the maintenance of human embryo in vitro by alginate co-encapsulation of human blastocyst and decidualized endometrial stromal cells (EnSCs) under melatonin-fortified culture conditions. The effectiveness of the 3D culture system was studied through monitoring of embryo development in terms of survival time, viability, morphological changes, and production of the two hormones of 17b-oestradiol and human chorionic gonadotropin. The embryo structural integrity was preserved during alginate encapsulation; however, only 23 % of the encapsulated embryos could retain in the hydrogels over time and survived until day 4 post-encapsulation. The culture medium fortification with melatonin significantly elevated the maintenance rate of expanded embryos in alginate beads by 65 % and prolonged survival time of human embryos to day 5. Furthermore, embryo co-culture with EnSCs using melatonin-fortified medium increased the survival time of encapsulated embryos to 44 %. The levels of two measured hormones significantly rose at day 4 in comparison with day 2 post-encapsulation especially in the group co-encapsulated with EnSCs and cultivated in melatonin-fortified culture medium. These data are the first evidence representing in vitro development of human embryos until day 10 post-fertilization. This achievement can facilitate the investigation of the mechanisms regulating human embryo development.

Comparative Immunophenotypic Characteristics, Proliferative Features, and Osteogenic Differentiation of Stem Cells Isolated from Human Permanent and Deciduous Teeth with Bone Marrow.

To find out differences and similarities in phenotypic, proliferative, and trans-differentiation properties of stem cells isolated from pulp of deciduous (SHEDs) and permanent (DPSCs) teeth with human bone marrow stem cells (BMSCs), we examined the expression of mesenchymal and embryonic stem cell markers in relation to the proliferation and osteogenic differentiation potentials of these cells. In this way, after isolating SHEDs, DPSCs, and BMSCs, cell proliferation was evaluated and population doubling time was calculated accordingly. Expression patterns of mesenchymal, hematopoietic, and embryonic stem cell markers were assessed followed by examining differentiation potential toward osseous tissue through alizarin red staining and qRT-PCR. Based on the results, the proliferation rates of SHEDs and DPSCs were significantly higher than that of BMSCs (P < 0.0001). High expression of mesenchymal stem cell markers and weak expression of hematopoietic markers were observed in all the three groups. The mean expression of OCT-4 was significantly higher in SHEDs and DPSCs (P = 0.028), while the expression of SSEA-4 was lower (P = 0.006) compared to BMSCs. Osteogenic differentiation potential of SHEDs was greater than DPSCs; however, it was lower than that of BMSCs. Conclusively, the distinctive immunophenotyping, proliferation rate, and differentiation pattern of SHEDs and DPSCs discriminate these cells from BMSCs. Furthermore, dissimilarity in differentiation potential is evidence implying that SHEDs might be more primitive stem cell population compared to DPSCs.

Comparative evaluation of in vivo biocompatibility and biodegradability of regenerated silk scaffolds reinforced with/without natural silk fibers.

Nowadays, exceptional advantages of silk fibroin over synthetic and natural polymers have impelled the scientists to application of this biomaterial for tissue engineering purposes. Recently, we showed that embedding natural degummed silk fibers in regenerated Bombyx mori silk-based scaffold significantly increases the mechanical stiffness, while the porosity of the scaffolds remains the same. In the present study, we evaluated degradation rate, biocompatibility and regenerative properties of the regenerated 2% and 4% wt silk-based composite scaffolds with or without embedded natural degummed silk fibers within 90 days in both athymic nude and wild-type C57BL/6 mice through subcutaneous implantation. In all scaffolds, a suitable interconnected porous structure for cell penetration was seen under scanning electron microscopy. Compressive tests revealed a functional relationship between fiber reinforcement and compressive modulus. In addition, the fiber/fibroin composite scaffolds support cell attachment and proliferation. On days 30 to 90 after subcutaneous implantation, the retrieved tissues were examined via gross morphology, histopathology, immunofluorescence staining and reverse transcription-polymerase chain reaction as shown in Figure 1. Results showed that embedding the silk fibers within the matrix enhances the biodegradability of the matrix resulting in replacement of the composite scaffolds with the fresh connective tissue. Fortification of the composites with degummed fibers not only regulates the degradation profile but also increases the mechanical performance of the scaffolds. This report also confirmed that pore size and structure play an important role in the degradation rate. In conclusion, the findings of the present study narrate key role of additional surface area in improving in vitro and in vivo biological properties of the scaffolds and suggest the potential ability of these fabricated composite scaffolds for connective tissue regeneration. spjba;30/6/793/FIG10885328215601925F1fig1-0885328215601925Figure 1.Illustrative summary of the main methods and findings.RS: regenerated silk; RSF: regenerated fibroin/ silk fiber composite scaffolds; H&E: Hematoxylin and eosin; COX-1: Cyclooxygenase.

Tissue Engineering and Regenerative Medicine in Iran: Current State of Research and Future Outlook.

During two decades ago, Iran has exhibited remarkable increase in scientific publication in different aspects including tissue engineering and regenerative medicine (TERM). The field of TERM in Iran dates comes back to the early part of the 1990 and the advent of stem cell researches. Nowadays, Iran is one of the privileged countries in stem cell therapy in the Middle East. The next major milestone in TERM was application and fabrication of scaffolds for tissue engineering in the early 2000s with a focus on engineering bone and cartilage tissue. A good amount of thoughtful works has also yielded prototypes of other tissue substitutes such as nerve conduits, liver, and even heart. However, forward movement to clinical application of these products is still far from offering clinically acceptable solutions. In this study, we have presented a comprehensive review on the efforts of Iranian scientists in different issues of tissue engineering and regenerative medicine field.

Efficient generation of functional hepatocyte-like cells from menstrual blood-derived stem cells.

In recent years, the advantages of menstrual blood-derived stem cells (MenSCs), such as minimal ethical considerations, easy access and high proliferative ability, have inspired scientists to investigate the potential of MenSCs in cell therapy of different diseases. In order to characterize the potency of these cells for future cell therapy of liver diseases, we examined the potential of MenSCs to differentiate into hepatocytes, using different protocols. First, the immunophenotyping properties and potential of MenSCs to differentiate into osteoblasts, adipocytes and chondrocytes were evaluated. Thereafter, the differentiation protocols developed by two concentrations of hepatocyte growth factor (HGF) and oncostatin M (OSM), in combination with other components in serum-supplemented or serum-free culture media, were also investigated. The sequential differentiation was monitored by real-time PCR, immunostaining and functional assays. Our primary data revealed that the isolated MenSCs exhibited mesenchymal stem cell markers in parallel to OCT-4 as an embryonic marker. Regardless of differentiation procedures, the developed cells expressed mature hepatocyte markers, such as albumin, tyrosine aminotransferase and cytokeratin-18 at the mRNA and protein levels. They also showed functional properties of hepatocytes, including albumin secretion, glycogen storage and cytochrome P450 7A1 expression. However, the degree of differentiation was dependent on the concentrations of HGF and OSM. Indeed, omission of serum during the differentiation process caused typical improvement in hepatocyte-specific functions. This study is a novel report demonstrating the differentiation potential of MenSCs into hepatocyte-like cells. We recommend a complementary serum-free differentiation protocol for enrichment of in vitro production of functional MenSC-derived hepatocyte-like cells that could lead to a major step toward applied stem cell therapy of chronic liver diseases.

Comparative evaluation of differentiation potential of menstrual blood- versus bone marrow-derived stem cells into hepatocyte-like cells.

Menstrual blood has been introduced as an easily accessible and refreshing stem cell source with no ethical consideration. Although recent works have shown that menstrual blood stem cells (MenSCs) possess multi lineage differentiation capacity, their efficiency of hepatic differentiation in comparison to other stem cell resources has not been addressed so far. The aim of this study was to investigate hepatic differentiation capacity of MenSCs compared to bone marrow-derived stem cells (BMSCs) under protocols developed by different concentrations of hepatocyte growth factor (HGF) and oncostatin M (OSM) in combination with other components in serum supplemented or serum-free culture media. Such comparison was made after assessment of immunophenotye, trans-differentiation potential, immunogenicity and tumorigeicity of these cell types. The differential expression of mature hepatocyte markers such as albumin (ALB), cytokeratin 18 (CK-18), tyrosine aminotransferase and cholesterol 7 alpha-hydroxylase activities (CYP7A1) at both mRNA and protein levels in differentiating MenSCs was significantly higher in upper concentration of HGF and OSM (P1) compared to lower concentration of these factors (P2). Moreover, omission of serum during differentiation process (P3) caused typical improvement in functions assigned to hepatocytes in differentiated MenSCs. While up-regulation level of ALB and CYP7A1 was higher in differentiated MenSCs compared to driven BMSCs, expression level of CK-18, detected level of produced ALB and glycogen accumulation were lower or not significantly different. Therefore, based on the overall comparable hepatic differentiation ability of MenSCs with BMSCs, and also accessibility, refreshing nature and lack of ethical issues of MenSCs, these cells could be suggested as an apt and safe alternative to BMSCs for future stem cell therapy of chronic liver diseases.

Chondrogenic differentiation of menstrual blood-derived stem cells on nanofibrous scaffolds.

Cartilage tissue engineering is a promising technology to restore and repair cartilage lesions in the body. In recent years, significant advances have been made using stem cells as a cell source for clinical goals of cartilage tissue engineering. Menstrual blood-derived stem cells (MenSCs) is a novel population of stem cells that demonstrate the potential and differentiate into a wide range of tissues including the chondrogenic lineage. Incorporation of cell culture with extracellular matrix (ECM) like substratum plays an important role in cartilage tissue regeneration by providing attachment sites as well as bioactive signals for cells to grow and differentiate into chondrogenic lineage. The electrospun nanofibers are a class of polymer-based biomaterials that have been extensively utilized in tissue engineering as ECM-like scaffold. This chapter discusses potential of electrospun nanofibers for cell-based cartilage tissue engineering and presents detailed protocols on immunophenotyping characterization and chondrogenic differentiation of MenSCs seeded in poly-ε-caprolactone (PCL) nanofibers. The isolated MenSCs are characterized using flow cytometry, seeded on the nanofibers, imaged using scanning electron microscopy, and subsequently differentiated into chondrogenic lineage in culture medium containing specific growth factors and cytokines. Immunofluorescence and alcian blue staining are used to evaluate the development of seeded MenSCs in PCL nanofibrous scaffold into chondrogenic lineage.

Characterization and chondrogenic differentiation of menstrual blood-derived stem cells on a nanofibrous scaffold.

INTRODUCTION: The recent identification of menstrual blood-derived stem cells (MenSCs) as a unique population of stem cells has created enormous promise for tissue engineering. In this study, after characterization of MenSCs in comparison with bone marrow-derived stem cells (BMSCs), the potential of MenSCs seeded into electrospun, biodegradable, nanofibrous scaffolds in order to engineer cartilage was evaluated. METHODS: MenSCs and BMSCs were isolated by discontinuous density gradient centrifugation and plastic adherence. After characterization of MenSCs compared with BMSCs, MenSC differentiation into chondrocytes was investigated on a nanofibrous scaffold with specific growth and differentiation factors. The scaffold was prepared from polycaprolactone (PCL) and its surface was modified by plasma treatment. RESULTS: Flow cytometric analysis of expanded cells showed that MenSCs typically express some surface and intracellular markers associated with BMSCs. But marked expression of OCT-4 and the absence of STRO1 distinguished them from mesenchymal stem cells obtained from bone marrow. Based on scanning electron microscope images, the MenSCs were strongly anchored to the highly porous scaffold, which they penetrated and proliferated on. The scaffold contained an extensive cartilage-like extracellular matrix with about 50% greater glycosaminoglycan content than control MenSCs differentiated in a two-dimensional (2D) culture system (p<0.05). Considerable amounts of proteoglycan were produced by the cells differentiated on the scaffold, as demonstrated by Alcian blue staining. Unlike undifferentiated MenSCs, cells differentiated on the scaffold had strong immunoreactivity with monoclonal antibody against collagen type II. CONCLUSIONS: The evidence presented in this study introduces MenSCs as a suitable stem cell population candidate for cartilage tissue engineering.

Osteogenic differentiation of stem cells derived from menstrual blood versus bone marrow in the presence of human platelet releasate.

In recent decades, stem cell therapy has been introduced as a novel therapeutic approach for patients suffering from bone disorders. Recently, menstrual blood has been identified as an easily accessible and recycled stem cell source. However, the osteogenic differentiation capacity of menstrual blood-derived stem cells (MenSCs) compared with other adult stem cells remained unsolved. The aim of this study was to investigate the osteogenic differentiation capacity of MenSCs compared to bone marrow-derived mesenchymal stem cells (BMSCs) in the presence of human platelet releasate (HPR). Our results showed that MenSCs were strongly positive for mesenchymal and negative for hematopoietic stem cell markers in a similar manner to BMSCs. In contrary to BMSCs, MenSCs exhibited marked expression of OCT-4 and a significantly higher proliferative capacity. Mineralization, as judged by alizarin red staining, was more pronounced in differentiated BMSCs than in differentiated MenSCs in an osteogenic medium fortified with fetal bovine serum (FBS). However, FBS substitution with HPR in a differentiation medium resulted in typical impact on intensity of MenSC mineralization. The results of semiquantitative reverse transcription-polymerase chain reaction showed comparable levels of parathyroid hormone receptor and osteocalcin transcripts in both types of differentiated stem cells in an HPR medium supplemented with osteogenic inducers. However, the upregulation level of alkaline phosphatase was relatively lower in differentiated MenSCs than that in differentiated BMSCs. We concluded that despite lower osteogenic differentiation capacity of MenSCs compared to BMSCs, substitution of FBS with HPR could equalize the osteogenic differentiation of MenSCs. Therefore, by taking advantage of osteogenic driving potential of HPR, MenSCs could be introduced as an apt and safe alternative to BMSCs for bone tissue-engineering purposes.

Proliferation and chondrogenic differentiation potential of menstrual blood- and bone marrow-derived stem cells in two-dimensional culture.

Menstrual blood is easily accessible, renewable, and inexpensive source of stem cells. In this study, we investigated the chondrogenic differentiation potential of menstrual blood-derived stem cells (MenSCs) compared with that of bone marrow-derived stem cells (BMSCs) in two-dimensional culture. Following characterization of isolated cells, the potential for chondrogenic differentiation of MenSCs and BMSCs was evaluated by immunocytochemical and molecular experiments. MenSCs were strongly positive for mesenchymal stem cell markers in a manner similar to that of BMSCs. In contrast to BMSCs, MenSCs exhibited marked expression of OCT4, and higher proliferative capacity. Differentiated MenSCs showed strong immunoreactivity to a monoclonal antibody against Collagen type 2, in a pattern similar to BMSCs. Accumulation of proteoglycans in differentiated MenSCs was also comparable with that in differentiated BMSCs. However, the mRNA expression patterns as judged by RT-PCR of chondrogenic markers such as Collagen 2A1, Collagen 9A1 and SOX9 in MenSCs were different from those in BMSCs. Given these findings, MenSCs appear to be a unique stem cell population with higher proliferation than and comparable chondrogenic differentiation ability to BMSCs in two-dimensional culture. Much quantitative studies at the molecular level may elucidate the reasons for the observed differences in MenSCs and BMSCs.