Unrestricted Somatic Stem Cells Research Articles

Current Perspectives and Progress in Preoperative Portal Vein Embolization with Stem Cell Augmentation (PVESA).

Portal vein embolization with stem cell augmentation (PVESA) is an emerging approach for enhancing the growth of the liver segment that will remain after surgery (i.e., future liver remnant, FLR) in patients with liver cancer. Conventional portal vein embolization (PVE) aims to induce preoperative FLR growth, but it has a risk of failure in patients with underlying liver dysfunction and comorbid illnesses. PVESA combines PVE with stem cell therapy to potentially improve FLR size and function more effectively and efficiently. Various types of stem cells can help improve liver growth by secreting paracrine signals for hepatocyte growth or by transforming into hepatocytes. Mesenchymal stem cells (MSCs), unrestricted somatic stem cells, and small hepatocyte-like progenitor cells have been used to augment liver growth in preclinical animal models, while clinical studies have demonstrated the benefit of CD133 + bone marrow-derived MSCs and hematopoietic stem cells. These investigations have shown that PVESA is generally safe and enhances liver growth after PVE. However, optimizing the selection, collection, and application of stem cells remains crucial to maximize benefits and minimize risks. Additionally, advanced stem cell technologies, such as priming, genetic modification, and extracellular vesicle-based therapy, that could further enhance efficacy outcomes should be evaluated. Despite its potential, PVESA requires more investigations, particularly mechanistic studies that involve orthotopic animal models of liver cancer with concomitant liver injury as well as larger human trials.

Modulation of Inflammation By Unrestricted Somatic Stem Cells (USSCs) to Suppress Fibrosis in Mice with Dystrophic Epidermolysis Bullosa

Modulation of Inflammation By Unrestricted Somatic Stem Cells (USSCs) to Suppress Fibrosis in Mice with Dystrophic Epidermolysis Bullosa

Restoring Synaptic Function: How Intranasal Delivery of 3D-Cultured hUSSC Exosomes Improve Learning and Memory Deficits in Alzheimer's Disease.

Memory problems are often the first signs of cognitive impairment related to Alzheimer's disease (AD), and stem cells and stem cell-derived exosomes (EXOs) have been studied for their therapeutic potential to improve the disease signs. While many studies have shown the anti-inflammatory and immunomodulatory effects of stem cells and exosomes on improving memory in different AD models, there is still insufficient data to determine how they modulate neural plasticity to enhance spatial memory and learning ability. Therefore, we conducted a study to investigate the effects of exosomes derived from 3D-cultured human Unrestricted Somatic Stem Cells (hUSSCs) on spatial memory and neuroplasticity markers in a sporadic rat model of AD. Using male Wistar rats induced by intracerebral ventricle injection of streptozotocin, we demonstrated that intranasal administration of hUSSC-derived exosomes could decrease Aβ accumulation and improve learning and memory in the Morris water maze test. We also observed an increase in the expression of pre-synaptic and post-synaptic molecules involved in neuronal plasticity, including NMDAR1, integrin β1, synaptophysin, pPKCα, and GAP-43, in the hippocampus. Our findings suggest that intranasal administration of exosomes can ameliorate spatial learning and memory deficits in rats, at least in part, by increasing the expression of neuroplasticity proteins. These results may encourage researchers to further investigate the molecular pathways involved in memory improvement after stem cell and exosome therapy, with the goal of increasing the efficacy and safety of exosome-based treatments for AD.

Early Postnatal Expression of Tgfβ-1 and Fgf-2 Correlates With Regenerative Functions of Unrestricted Somatic Stem Cell Infusion After Rabbit GMH-IVH.

Intraventricular hemorrhage (IVH) is a severe complication of preterm birth associated with white matter injury (WMI) and reduced neurogenesis. IVH commonly arises from the germinal matrix, a highly cellular, transient structure, where all precursor cells are born, proliferate, and migrate during brain development. IVH leads to reduced progenitor cell proliferation and maturation and contributes to WMI. Interruption of oligodendrocyte lineage (OL) proliferation and maturation after IVH will prevent myelination. We evaluated whether unrestricted somatic stem cells (USSCs) could recover OL lineage, as USSC release multiple relevant growth factors and cytokines. The effects of USSC infusion at 24 hours after IVH were assessed in the periventricular zone by analysis of OL lineage-specific progression (PDGFR+, OLIG2+, NKX2.2+ with Ki67), and this was correlated with growth factors TGFβ1, FGF2 expression. The early OL cell lineage by immunofluorescence and cell density quantitation showed significant reduction after IVH (P < .05 both PDGFR+, OLIG2+ at day 3); with significant recovery after injection of USSCs (P < .05 both PDGFR+, OLIG2+ at day 3). CSF protein and tissue mRNA levels of TGFβ1 were reduced by IVH and recovered after USSC (P < .05 for all changes). FGF2 showed an increased mRNA after USSC on day3 (P < .05). Cell cyclin genes were unaffected except for the cycle inhibitor P27Kip1 which increased after IVH but returned to normal after USSC on day 3. Our findings demonstrated a plausible mechanism through which USSCs can aid in developmental myelination by recovery of OL proliferation and maturation along with correlative changes in growth factors during brain development.

Numerous Types of Stem Cells Possess Potential to Treat Congenital Hydrocephalus

Twenty-five percent of premature neonate’s experience Intraventricular Hemorrhage (IVH) and 10% of these events are complicated further by the occurrence of hydrocephalus. The number of infants at high risk for IVH and therefore Post Hemorrhagic Hydrocephalus (PHH), is rising due to improved survival rate of premature infants. Fetal onset hydrocephalus is a heterogeneous brain disorder involving Cerebrospinal Fluid (CSF) dynamics and is a result of both genetic and environmental factors. Mesenchymal stem cells present themselves as a potent therapeutic modality for brain injury based on their multipotency, anti-inflammatory, antioxidant and angiogenic functions. Numerous animal model clinical provide evidence that Mesenchymal Stem Cells (MSCs) can target nearly all mechanisms involved in the pathogenesis of hydrocephalus. Unrestricted somatic stem cells possess anti-inflammatory and immunomodulatory properties as well as release growth factors and cytokines with known neuroprotective and axonal growth promoting functions. Neural stem cells are self-sustaining, pluripotent cells that have the capability to correct brain maldevelopment, reduce brain damage, promote regeneration and repair via neurotrophic and immunomodulatory mechanisms and direct cell replacement. For these reasons, stem cells possess the potential to be an effective therapy and should be further researched.

Expression analysis of genes involved in the expansion of hematopoietic stem cells (SCF, Flt3-L, TPO, IL-3, and IL-6) in unrestricted somatic stem cells cultured on fibrin

Umbilical cord blood (UCB) transplantation is a promising therapeutic approach for patients lacking HLA-matched donors. A main limitation to the use of UCB-derived HSCs (UCB–HSCs) is the low number of transplantable cells. Novel culture strategies are being developed to increase the number of HSCs. Unrestricted somatic stem cells (USSCs) have been identified as promising stromal cells for supporting HSC expansion. The current study aimed to explore the effect of fibrin on the expression of hematopoiesis-related genes (SCF, Flt3-L, TPO, IL-3, and IL-6) in USSCs. USSCs were isolated from UCB and characterized by flow cytometry and in vitro multilineage differentiation ability. DAPI staining and the MTT assay were used to assess the effect of fibrin on USSC viability. The cell attachment was evaluated using SEM. qRT-PCR was performed to evaluate the expression of SCF, Flt3-L, TPO, IL-3, and IL-6 in USSCs cultured on 3D fibrin scaffolds. USSCs were positive for CD73, CD105, and CD166 and negative for CD45. Alizarin red and Oil red O stains confirmed calcium deposition and lipid vacuoles in USSCs. Results obtained from DAPI and MTT assays revealed a positive effect of fibrin on USSC viability. Cells cultured on fibrin express significantly higher levels of SCF and TPO compared to those grown in a 2D environment. The positive effect of fibrin on IL-6 levels was reversed. Fibrin did not affect Flt3-L expression and IL-3 mRNA expression was not detected in either group. The results of this study provide the basis for developing further research on the ex vivo expansion of HSCs with USSCs.

294 - Modulation of Inflammation By Unrestricted Somatic Stem Cells (USSCs) to Suppress Fibrosis in Mice with Dystrophic Epidermolysis Bullosa

294 - Modulation of Inflammation By Unrestricted Somatic Stem Cells (USSCs) to Suppress Fibrosis in Mice with Dystrophic Epidermolysis Bullosa

Cardiac injection of USSC boosts remuscularization of the infarcted heart by shaping the T-cell response

Regenerating the injured heart remains one of the most vexing challenges in cardiovascular medicine. Cell therapy has shown potential for treatment of myocardial infarction, but low cell retention so far has limited its success. Here we show that intramyocardial injection of highly apoptosis-resistant unrestricted somatic stem cells (USSC) into infarcted rat hearts resulted in an unprecedented thickening of the left ventricular wall with cTnT+/BrdU+ cardiomyocytes that was paralleled by progressively restored ejection fraction. USSC induced significant T-cell enrichment in ischemic tissue with enhanced expression of T-cell related cytokines. Inhibition of T-cell activation by anti-CD28 monoclonal antibody, fully abolished the regenerative response which was restored by adoptive T-cell transfer. Secretome analysis of USSC and lineage tracing studies suggest that USSC secrete paracrine factors over an extended period of time which boosts a T-cell driven endogenous regenerative response mainly from adult cardiomyocytes.

Evaluation of Unrestricted Somatic Stem Cells Therapy in an Ex-Vivo and in-Vivo Acquired Severe Aplastic Anemia Model

Background: In acquired severe aplastic anemia (aSAA), oligoclonal expansion of dysregulated CD8+ cytotoxic T cells, abnormal function of CD4+ T helper cells, along with elevated production of IFN-γ and TNF-α have been associated with the apoptosis of hematopoietic stem and progenitor cells (HSPC) (Young, N Engl J Med, 2018). Liao and Cairo et al (Cell Transplantation, 2014) have demonstrated that cord blood-derived unrestricted somatic stem cells (USSCs) could significantly reverse the abnormal/inverted ratio of CD4:CD8 T cells, increases the number of FOXP3A positive Treg cells and decrease the level of IFN-γ in an animal model of recessive dystrophic epidermolysis bullosa (RDEB). Alternative therapies are in great need for patients with aSAA as immunosuppressive therapy (IST) overall responses are sub-optimal. Objectives:To determine the effect of USSCs on HSPC survival, differentiation and phosphorylation pathways in an ex-vivo culture of aSAA with human CD34+ cells.To determine the effect of USSCs administration on blood cell count recovery, bone marrow (BM) cellularity and survival in an in-vivo inflammatory cytokine mediated mice model of aSAA. Design/Methods: Human HSPC were cultured with SCF, FLT3 and human TPO. HSPCs alone, with and without IFN-γ and TNF-α served as controls. USSCs (transwell and direct) were added to the culture. HSPC were harvested and assayed for their survival at day 7 and 14. Annexin-V+/PI+ were referred to as late apoptotic cells. Each experimental condition was set up in triplicate. The cells were cultured at 37°C with 5% CO2. Multi-lineage differentiation capacity was assessed with a selective colony forming units (CFU) assay and compared between experimental groups. Signaling pathways were determined using phosphor-flow cytometric analysis of pSTAT1. For the immune mediated mouse model of aSAA, 8-week-old C57BL/6 mice were irradiated with 6.5Gy TBI. Spleen lymphocytes were collected from FVB donors, and injected 4 hours post-radiation into B6 recipient mice via the retro-orbital vein, at 1-1.5 × 106 cells/recipient in 100μL PBS. Each experimental group (PBS control and USSCs) included 20 mice per group. Mice were continuously monitored for their survival. Peripheral blood (PB) was analyzed using a VETSCAN® HM5 Analyzer. Mean ± SEM of the blood counts was compared between experimental groups. Mice femur bones were extracted and cleaned of soft tissue, fixed and sectioned. Paraffin sections were stained with Hematoxylin and Eosin (H&E) to assess morphology. Results: The myelosuppressive effect of IFN-γ and TNF-α was significantly rescued (4-fold increase) by the addition of USSCs (transwell) at day 7. After 28 days direct co-culture with USSCs increased CD34+ survival as well (p<0.001) from 5 to 35 cells/µl. A significantly higher percent of viable cells (73% versus 63%) was observed among the USSCs treated cells (P<0.05). Phosphor-flow cytometric analysis demonstrated an almost 50% decrease in pSTAT1 in the presence of USSCs (p<0.05). Based on CFU analysis, CD34+ cells cultured in the presence of USSCs were able to produce more CFU (52, SD±3.7) at day 7 (p<0.01) compared to IFN-γ and TNF-α treated cells (16, SD±2.8). Also, USSCs were associated with more BFU (p<0.05) at day 14. In our immune mediated aplastic anemia mice model, treatment with USSCs was associated with substantial prolonged mice survival (p=0.02) (Figure 1a). Evaluation of PB counts demonstrated increased hemoglobin levels at day 14 in the USSCs treated mice (p<0.05) 5.6g/dL (SD±0.6), compared to PBS treated mice 2.1g/dL (SD±0.1). BM evaluation of USSCs treated mice versus PBS control displayed higher cellularity in the USSCs treated sections (Figure 1b). Conclusions: Cellular therapy, such as USSCs, may be instrumental in the treatment of aSAA, specifically by increasing BFU-E and eventually hemoglobin levels. Future studies will need to be done to investigate the exact mechanisms of action and the clinical efficacy of this novel cellular therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Fenugreek Extract-Loaded Polycaprolacton/Cellulose Acetate Nanofibrous Wound Dressings for Transplantation of Unrestricted Somatic Stem Cells: An In Vitro and In Vivo Evaluation

Complex pathophysiology of diabetic wounds causes a delayed wound healing response. Advanced wound dressing materials that deliver biochemical cues are of particular interest in wound healing research. Here, we developed a dual-function delivery vehicle for drug and cell delivery applications to treat diabetic wounds. The delivery system was developed via electrospinning of polycaprolacton/cellulose acetate solution containing fenugreek extract. The produced delivery vehicle was characterized using microstructural studies, cell viability assay, cytoprotection assay, cell migration assay, In Vitro anti-inflammatory assay, free radical scavenging assay, tensile strength studies, swelling studies, and protein adsorption test. Scaffolds were then seeded with 30000 unrestricted somatic stem cells and transplanted into the rat model of excisional diabetic wound. Wound healing assay showed that the co-delivery of fenugreek extract and unrestricted somatic stem cells led to a substantial improvement in the healing activity of electrospun dressings, as evidenced by higher wound contraction, epithelial thickness, and collagen deposition in this group compared with other experimental groups. Gene expression analysis showed that dual-function delivery system could increase the expression level of VEGF, b-FGF, and collagen type II genes. Furthermore, the tissue expression level of IL-1β and glutathione peroxidase genes was significantly reduced in this group compared with other groups. This study shows that the developed system may be considered as a potential treatment modality for diabetic wounds in the clinic.

Influence of Xenogeneic and Alloplastic Carriers for Bone Augmentation on Human Unrestricted Somatic Stem Cells.

Alloplastic and xenogeneic bone grafting materials are frequently used for bone augmentation. The effect of these materials on precursor cells for bone augmentation is yet to be determined. The aim of this study was to ascertain, in vitro, how augmentation materials influence the growth rates and viability of human unrestricted somatic stem cells. The biocompatibility of two xenogeneic and one alloplastic bone graft was tested using human unrestricted somatic stem cells (USSCs). Proliferation, growth, survival and attachment of unrestricted somatic stem cells were monitored after 24 h, 48 h and 7 days. Furthermore, cell shape and morphology were evaluated by SEM. Scaffolds were assessed for their physical properties by Micro-CT imaging. USSCs showed distinct proliferation on the different carriers. Greatest proliferation was observed on the xenogeneic carriers along with improved viability of the cells. Pore sizes of the scaffolds varied significantly, with the xenogeneic materials providing greater pore sizes than the synthetic inorganic material. Unrestricted somatic stem cells in combination with a bovine collagenous bone block seem to be very compatible. A scaffold’s surface morphology, pore size and bioactive characteristics influence the proliferation, attachment and viability of USSCs.

Emerging therapies for brain recovery after IVH in neonates: Cord blood derived Mesenchymal Stem Cells (MSC) and Unrestricted Somatic Stem Cells (USSC)

In this report, we summarize evidence on mechanisms of injury after intraventricular hemorrhage resulting in post-hemorrhagic white matter injury and hydrocephalus and correlate that with the possibility of cellular therapy. We describe how two stem cell lines (MSC & USSC) acting in a paracrine fashion offer promise for attenuating the magnitude of injury in animal models and for improved functional recovery by: lowering the magnitude of apoptosis and neuronal cell death, reducing inflammation, and thus, mitigating white matter injury that culminates in improved motor and neurocognitive outcomes. Animal models of IVH are analyzed for their similarity to the human condition and we discuss merits of each approach. Studies on stem cell therapy for IVH in human neonates is described. Lastly, we offer suggestions on what future studies are needed to better understand mechanisms of injury and recovery and argue that human trials need to be expanded in parallel to animal research.

267 - Human Cord Blood Derived Unrestricted Somatic Stem Cells Promote Wound Healing and Suppress Inflammation to Fibrosis Transition in an Animal Model of Recessive Dystrophic Epidermolysis Bullosa

267 - Human Cord Blood Derived Unrestricted Somatic Stem Cells Promote Wound Healing and Suppress Inflammation to Fibrosis Transition in an Animal Model of Recessive Dystrophic Epidermolysis Bullosa

Analysis of Spontaneous and Induced Osteogenic Differentiation in 3D-micromasses of Human Multipotent Stem Cells.

Craniofacial reconstruction of extensive bone defects causes high morbidity to patients. Contemporary reconstructive surgery aims at restoring lost bone with either autogenous bone or substitutes. Multipotent unrestricted somatic stem cells (USSC) show a potential for osteoblast differentiation and are increasingly used in tissue engineering. The osteogenic potential of USSC micromasses influenced by dexamethasone, ascorbic acid and β-glycerophosphate (DAG) seems promising. The present study evaluated the effects of DAG and MAPK, ERK and PI3K/Akt-pathway inhibitors on growth and mineralization of USSC micromasses. Cells: i) USSC-18 (female, Passage 8), ii) USSC-8 (female Passage 9), and iii) USSC-8/17 (male, Passage 8), all cultured in 350 ml DMEM, with 150 ml fetal bovine serum, 5 ml penicillin/streptomycin and 5 ml L-glutamine. Differentiation was induced using 50 μM dexamethasone in DMEM, 50 mM ascorbic acid in PBS and 1 M β-glycerolphosphate in PBS. Microtome slices were dyed with OsteoImage™ and analyzed under fluorescence microscopy. Significant increase in size and mineralization of DAG-treated micromasses was found on days 3 (p<0.001), 6 (p<0.001) and 7 (p<0.001). The ERK-pathway inhibitor, FR180204, significantly reduced micromass growth and mineralization in non-DAG treated cells (p<0.001) but showed increased mineralization in DAG-treated cells (p=0.014). The PI3K/Akt-pathway inhibitor, LY294002, did not significantly affect micromass growth but significantly decreased mineralization (p<0.001). The MAP-kinase inhibitor, U0126, significantly reduced micromass growth (p=0.001) and mineralization (p=0.001) of DAG-treated cells. DAG is a strong initiator of osteogenic differentiation. The PI3K/Akt-pathway inhibitor and the ERK-pathway inhibitor, FR180204, control osteogenic differentiation of 3D-micromasses. These results may facilitate preconditioning of cell cultures in guided tissue regeneration.

The Effect of Exosomes Derived from Unrestricted Somatic Stem Cells on Murine Model of Sepsis

Sepsis is a systemic infection mainly caused by bacterial infections. Despite all efforts and advances in the treatment of sepsis, it is still considered one of the leading causes of death in hospitalized patients. Today, we have to use novel therapies and one of the most important is cell-free therapy. Exosomes have been shown to contain the contents of their parent cells and that they do not generate an immune response between different individuals which makes them a good candidate for transplantation. Unrestricted somatic stem cells (USSC), also known as mesenchymal stem cell progenitors due to their high proliferative capacity and low immune response, may be a novel therapy for sepsis. In this study, the effect of USSC-derived exosomes on sepsis was investigated using a mouse model. USSCs were isolated from human cord blood and characterized by flow cytometry and multi-lineage differentiation. The exosomes were then harvested from USSCs and characterized by transmission electron microscopy, Western blotting, and dynamic light scattering. The harvested exosomes were injected into the mouse model of sepsis. Biochemical, histological, molecular, and survival studies were performed in different groups. Our observations showed that USSC-derived exosomes can reduce inflammation in septic mice. Histopathologic and biochemical findings in the sham group showed multiorgan involvement, but these changes disappeared after 7 days of exosome administration. Moreover, the expression of IRAK-1 and TRAF-6 (main adapter molecules in signaling pathways of inflammation) was decreased through negative regulation by miR-146a after 72 h of exosome administration. A 2-fold increase in the level of IL-10 and a 2-fold decrease in the levels of IL-6 and TNF-α was observed. In conclusion, we showed that direct injection of USSC-derived exosomes can be one of the important methods for the treatment of various aspects of sepsis due to their immunomodulatory properties.

In vitro evaluation of ferutinin on proliferation and osteogenesis differentiation in human unrestricted Somatic stem cells

Osteoporosis is a common disease in post-menopausal women. The increased risk of breast cancer and malignancy with hormone replacement, hampers its wide-usage. Phytoestrogens are known to have selective estrogen receptor modulator activity. The present study aims to determine how ferutinin affects unrestricted human Somatic Stem Cells (USSCs) osteogenic differentiation. The effect of ferutinin on USSCs proliferation was assessed by MTT assay while osteogenesis was evaluated using Alkaline Phosphatase Activity (ALP), calcium deposition and Alizarin Red Staining. Quantitative real-time PCR was applied to examine the expression of bone specific genes such as osteocalcin, Runx2, and BMP-2. Ferutinin (5–15 µg/mL) could positively impact on the proliferation of cells in a dose-dependent manner. Also, ALP enzyme activity and calcium deposition were enhanced in the presence of ferutinin. Based on real-time PCR results, ferutinin could increase the expression of bone marker genes. The pattern of ferutinin effect on gene expression is similar to standard synthetic estrogen, 17-β-estradiol. In the presence of the estrogen activity inhibitor (ICI), the effect of ferutinin on ALP and gene level was diminished. In conclusion, ferutinin may be considered as a potential candidate for the stem cell therapy in osteoporosis.

Human Cord Blood Derived Unrestricted Somatic Stem Cells Restore Aquaporin Channel Expression, Reduce Inflammation and Inhibit the Development of Hydrocephalus After Experimentally Induced Perinatal Intraventricular Hemorrhage.

Intraventricular hemorrhage (IVH) is a severe complication of preterm birth associated with cerebral palsy, intellectual disability, and commonly, accumulation of cerebrospinal fluid (CSF). Histologically, IVH leads to subependymal gliosis, fibrosis, and disruption of the ependymal wall. Importantly, expression of aquaporin channels 1 and 4 (AQP1 and AQP4) regulating respectively, secretion and absorption of cerebrospinal fluids is altered with IVH and are associated with development of post hemorrhagic hydrocephalus. Human cord blood derived unrestricted somatic stem cells (USSCs), which we previously demonstrated to reduce the magnitude of hydrocephalus, as having anti-inflammatory, and beneficial behavioral effects, were injected into the cerebral ventricles of rabbit pups 18 h after glycerol-induced IVH. USSC treated IVH pups showed a reduction in ventricular size when compared to control pups at 7 and 14 days (both, P < 0.05). Histologically, USSC treatment reduced cellular infiltration and ependymal wall disruption. In the region of the choroid plexus, immuno-reactivity for AQP1 and ependymal wall AQP4 expression were suppressed after IVH but were restored following USSC administration. Effects were confirmed by analysis of mRNA from dissected choroid plexus and ependymal tissue. Transforming growth factor beta (TGF-β) isoforms, connective tissue growth factor (CTGF) and matrix metalloprotease-9 (MMP-9) mRNA, as well as protein levels, were significantly increased following IVH and restored towards normal with USSC treatment (P < 0.05). The anti-inflammatory cytokine Interleukin-10 (IL-10) mRNA was reduced in IVH, but significantly recovered after USSC injection (P < 0.05). In conclusion, USSCs exerted anti-inflammatory effects by suppressing both TGF-β specific isoforms, CTGF and MMP-9, recovered IL-10, restored aquaporins expression towards baseline, and reduced hydrocephalus. These results support the possibility of the use of USSCs to reduce IVH consequences in prematurity.

Concurrent application of conductive biopolymeric chitosan/ polyvinyl alcohol/ MWCNTs nanofibers, intracellular signaling manipulating molecules and electrical stimulation for more effective cardiac tissue engineering

Fabrication of appropriate electro-conductive scaffold, application of small molecules (SMs), electrical stimulation (ES), and stem cells are steps forward in cardiac tissue engineering. Herein, for the first time, all mentioned factors have been taken into account concurrently regarding the differentiation of unrestricted somatic stem cells (USSCs) into cardiac cells. To accomplish this goal, electrospun composite scaffolds made of chitosan (CS) and polyvinyl alcohol (PVA) with multi-wall carbon nanotubes (MWCNTs; ranged from 0 to 2.5% w/w) were fabricated. After analyzing mechanical, electrical, and biological properties, the best MWCNTs portion was selected. Of note, the addition of 2%w/w MWCNTs to the CS/PVA samples reduced average fiber diameter from 225 to 110 nm, increasing electrical conductivity from 8 × 10−5 S/m to 9 × 10−3 S/m and trebling tensile strength. Then, by using a 10-day differentiation protocol (including CHIR99021, IWP2, SB431542, and purmorphamine SMs) and ES, USSCs were induced into cardiomyocytes. Overexpression of some cardiac-associated genes, including troponin I, CX43, and β-MHC, along with proper phenotypic alteration, were observed. (Scaffold + SM + ES) show a significant increase in the expression of these genes, 172, 5.3, and 64-times as normalized to undifferentiated cells, respectively. Our findings confirmed the importance of the simultaneous implementation of different factors for the developing functionality of the cardiac tissue. Altogether, it is recommended to deploy all mentioned features to obtain effective cardiac tissue engineering.

Synthesis of thermogel modified with biomaterials as carrier for hUSSCs differentiation into cardiac cells: Physicomechanical and biological assessment

One of the major challenges in cardiac cell therapy is cell death and low rate of cardiac differentiation. In this regard, a series of thermosensitive and injectable hydrogels with similar physicomechanical properties of cardiac tissue can be an ideal candidate for delivering human unrestricted somatic stem cells (hUSSCs) and improve the quality of cell therapy. Here, we designed N-isopropylacrylamide/acrylic acid/N-acryloxysuccinimide/2-hydroxyethyl methacrylate-poly lactide (NIPAAm/AAc/NAS/HEMAPLA) hydrogel via ring-opening polymerization for encapsulation of the cells. To improve biological activities, biomaterials like hyaluronic acid (HA), Aloe vera (AV), and silk fibroin (SF) were added with pure hydrogel (Pgel). The modulus of hydrogels was estimated between 68.1 and 74.63 kPa that was similar to the normal cardiac modulus. Moreover, the elastic region increased by adding biomaterials to Pgel. The results of RT-PCR and ICC demonstrated that the most expression of early genes (GATA4, NKX2.5) was related to Pgel/AV/SF group. In contrast, the highest expression of other genes (GJA1, TNNI3, MYH6) was observed in Pgel/HA/SF. The presence of biomaterials in the structure of hydrogel can play a key role in cell fate and the induction of cell differentiation as a factor influencing mechanotransduction. These hydrogels hold an excellent promise to deliver hUSSCs into damaged tissue for cardiac regeneration.

Functional omics analyses reveal only minor effects of microRNAs on human somatic stem cell differentiation

The contribution of microRNA-mediated posttranscriptional regulation on the final proteome in differentiating cells remains elusive. Here, we evaluated the impact of microRNAs (miRNAs) on the proteome of human umbilical cord blood-derived unrestricted somatic stem cells (USSC) during retinoic acid (RA) differentiation by a systemic approach using next generation sequencing analysing mRNA and miRNA expression and quantitative mass spectrometry-based proteome analyses. Interestingly, regulation of mRNAs and their dedicated proteins highly correlated during RA-incubation. Additionally, RA-induced USSC demonstrated a clear separation from native USSC thereby shifting from a proliferating to a metabolic phenotype. Bioinformatic integration of up- and downregulated miRNAs and proteins initially implied a strong impact of the miRNome on the XXL-USSC proteome. However, quantitative proteome analysis of the miRNA contribution on the final proteome after ectopic overexpression of downregulated miR-27a-5p and miR-221-5p or inhibition of upregulated miR-34a-5p, respectively, followed by RA-induction revealed only minor proportions of differentially abundant proteins. In addition, only small overlaps of these regulated proteins with inversely abundant proteins in non-transfected RA-treated USSC were observed. Hence, mRNA transcription rather than miRNA-mediated regulation is the driving force for protein regulation upon RA-incubation, strongly suggesting that miRNAs are fine-tuning regulators rather than active primary switches during RA-induction of USSC.