In vitro hepatic trans-differentiation of human mesenchymal stem cells using sera from congestive/ischemic liver during cardiac failure

Small Molecule-Mediated Stage-Specific Reprogramming of MSCs to Hepatocyte-Like Cells and Hepatic Tissue for Liver Injury Treatment

BACKGROUND

Derivation of hepatocytes from stem cells has been established through various protocols involving growth factor (GF) and small molecule (SM) agents, among others. However, mesenchymal stem cell-based derivation of hepatocytes still remains expensive due to the use of a cocktail of growth factors, and a long duration of differentiation is needed, thus limiting its potential clinical application.

METHODS

In this study, we developed a chemically defined differentiation strategy that is exclusively based on SM and takes 14 days, while the GF-based protocol requires 23-28 days.

RESULTS

We optimized a stage-specific differentiation protocol for the differentiation of rat bone marrow-derived mesenchymal stem cells (MSCs) into functional hepatocyte-like cells (dHeps) that involved four stages, i.e., definitive endoderm (DE), hepatic competence (HC), hepatic specification (HS) and hepatic differentiation and growth. We further generated hepatic tissue using human decellularized liver extracellular matrix and compared it with hepatic tissue derived from the growth factor-based protocol at the transcriptional level. dHep, upon transplantation in a rat model of acute liver injury (ALI), was capable of ameliorating liver injury in rats and improving liver function and tissue damage compared to those in the ALI model.

CONCLUSIONS

In summary, this is the first study in which hepatocytes and hepatic tissue were derived from MSCs utilizing a stage-specific strategy by exclusively using SM as a differentiation factor.

Generation and transplantation of hepatocytes-like cells using human origin hepatogenic serum for acute liver injury treatment

Liver failure is a critical disease for which regenerative therapies are still being explored. The major limitation in the use of a clinical grade, viable cell-based therapy approach is the scarce availability of sufficient number of in-vitro differentiated hepatocyte-like cells (HLC) that can induce regeneration and ameliorate liver injury. Here, we report for the first time an approach to engineer HLCs using sera of hyperbilirubin patients that act as a reservoir of differentiation factor. Utilizing our humanized approach, mesenchymal stem cells (hMSC) derived from umbilical cord tissue were transdifferentiated into HLC using patient-derived serum along with dimethyl sulfoxide (DMSO). We studied the effects of serum on the proliferation, cell cycle analysis, and apoptosis of hMSC by various differentiation combinations. We optimized the hepatic transdifferentiation ability of hMSC with hyperbilirubin serum treatment for a period of 7 days. Assessment of HLC functionalities was shown by quantifying the HLC spent medium for albumin and urea secretions. Transplantation of HLC in an acute liver injury (ALI) rat model showed an effective improvement in the liver function and histological changes in the liver. The results of this study suggest that hMSC-derived HLC using humanized hepatogenic serum holds a promising potential for cell transplantation, as an efficient therapy modality for liver failure in humans.

In vitro potential of human mesenchymal stem cells for corneal epithelial regeneration

Aim: To determine the potential of mesenchymal stem cells (MSC) for corneal epithelial regeneration in vitro. Materials & methods: Bone marrow MSC (BM-MSC) and adipose tissue MSC were analyzed for corneal epithelial and mesenchymal markers, using limbal stem cells and corneal cells as controls. MSC with better potential were cultured with specific mediums for epithelial induction. Transepithelial electric resistance and wound healing assay with human corneal epithelial cells were performed. Results: BM-MSC showed better potential, increased corneal markers, and higher transepithelial electric resistance values when induced with limbal epithelial culture medium. Induced BM-MSC promoted better wound healing of human corneal epithelial cells by paracrine secretion. Conclusion: BM-MSC has potential for corneal epithelial induction in a protocol compatible with human application.

Do we really need to differentiate mesenchymal stem cells into insulin-producing cells for attenuation of the autoimmune responses in type 1 diabetes: immunoprophylactic effects of precursors to insulin-producing cells

BACKGROUND

Type 1 diabetes (T1D) is a multifactorial autoimmune disorder where pancreatic beta cells are lost before the clinical manifestations of the disease. Administration of mesenchymal stem cells (MSCs) or MSCs differentiated into insulin-producing cells (IPCs) have yielded limited success when used therapeutically. We have evaluated the immunoprophylactic potentials of precursors to insulin-producing cells (pIPCs) and IPCs in nonobese diabetic (NOD) mice to ask a basic question: do we need to differentiate MSCs into IPCs or will pIPCs suffice to attenuate autoimmune responses in T1D?

METHODS

Bone marrow-derived MSCs from Balb/c mice were characterized following the International Society for Cellular Therapy (ISCT) guidelines. MSCs cultured in high-glucose media for 11 to 13 passages were characterized for the expression of pancreatic lineage genes using real-time polymerase chain reaction. Expression of the PDX1 gene in pIPCs was assessed using Western blot and fluorescence-activated cell sorting (FACS). Triple-positive MSCs were differentiated into IPCs using a three-step protocol after sorting them for cell surface markers, i.e. CD29, CD44, and SCA-1. Nonobese diabetic mice were administered pIPCs, IPCs, or phosphate-buffered saline (PBS) into the tail vein at weeks 9 or 10 and followed-up for 29-30 weeks for fasting blood glucose levels. Two consecutive blood sugar levels of more than 250 mg/dl were considered diabetic.

RESULTS

MSCs grown in high-glucose media for 11 to 13 passages expressed genes of the pancreatic lineage such as PDX1, beta2, neurogenin, PAX4, Insulin, and glucagon. Furthermore, Western blot and FACS analysis for PDX-1, a transcription factor necessary for beta cell maturation, confirmed that these cells were precursors of insulin-producing cells (pIPCs). NOD mice administered with pIPCs were better protected from developing diabetes with a protective efficacy of 78.4% (p < 0.009); however, administration of IPCs gave protective efficacy of 55% at the end of 28-30 weeks.

CONCLUSIONS

Precursors to insulin-producing cells seem to have better potential to arrest autoimmune response in type 1 diabetes when administered before the onset of the disease in NOD mice. When translated to humans, autologous mesenchymal stem cells grown in high-glucose media for 10 to 13 passages may have beneficial effects in individuals at high risk of developing type 1 diabetes.

A Patient-Inspired Ex Vivo Liver Tissue Engineering Approach with Autologous Mesenchymal Stem Cells and Hepatogenic Serum

Design and development of ex vivo bioengineered liver tissue substitutes intended for subsequent in vivo implantation has been considered therapeutically relevant to treat many liver diseases that require whole-organ replacement on a long-term basis. The present study focus on patient-inspired ex vivo liver tissue engineering strategy to generate hepatocyte-scaffold composite by combining bone marrow mesenchymal stem cells (BMSCs) derived from cardiac failure patients with secondary hyperbilirubinemia as primers of hepatic differentiation and hepatocyte growth factor (HGF)-enriched sera from same individuals as hepatic inducer. A biodegradable and implantable electrospun fibrous mesh of poly-l-lactic acid (PLLA) and gelatin is used as supporting matrix (average fiber diameter = 285 ± 64 nm, porosity = 81 ± 4%, and average pore size = 1.65 ± 0.77 μm). The fibrous mesh supports adhesion, proliferation, and hepatic commitment of patient-derived BMSCs of adequate stemness using HGF-enriched sera generating metabolically competent hepatocyte-like cells, which is comparable to the hepatic induction with defined recombinant growth factor cocktail. The observed results confirm the combinatorial effects of nanofiber topography and biochemical cues in guiding hepatic specification of BMSCs. The fibrous mesh-hepatocyte construct developed in this study using natural growth factors and BMSCs of same individual is promising for future therapeutic applications in treating damaged livers.

In vivo hepatogenic capacity and therapeutic potential of stem cells from human exfoliated deciduous teeth in liver fibrosis in mice

INTRODUCTION

Liver transplantation is a gold standard treatment for intractable liver diseases. Because of the shortage of donor organs, alternative therapies have been required. Due to their potential to differentiate into a variety of mature cells, stem cells are considered feasible cell sources for liver regeneration. Stem cells from human exfoliated deciduous teeth (SHED) exhibit hepatogenic capability in vitro. In this study, we investigated their in vivo capabilities of homing and hepatocyte differentiation and therapeutic efficacy for liver disorders in carbon tetrachloride (CCl4)-induced liver fibrosis model mice.

METHODS

We transplanted SHED into CCl4-induced liver fibrosis model mice through the spleen, and analyzed the in vivo homing and therapeutic effects by optical, biochemical, histological, immunological and molecular biological assays. We then sorted human leukocyte antigen-ABC (HLA-ABC)-positive cells from primary CCl4-damaged recipient livers, and analyzed their fusogenicity and hepatic characteristics by flow cytometric, genomic DNA, hepatocyte-specific gene assays. Furthermore, we examined the treatment effects of HLA-positive cells to a hepatic dysfunction by a secondary transplantation into CCl4-treated mice.

RESULTS

Transplanted SHED homed to recipient livers, and expressed HLA-ABC, human hepatocyte specific antigen hepatocyte paraffin 1 and human albumin. SHED transplantation markedly recovered liver dysfunction and led to anti-fibrotic and anti-inflammatory effects in the recipient livers. SHED-derived HLA-ABC-positive cells that were sorted from the primary recipient liver tissues with CCl4 damage did not fuse with the host mouse liver cells. Sorted HLA-positive cells not only expressed human hepatocyte-specific genes including albumin, cytochrome P450 1A1, fumarylacetoacetase, tyrosine aminotransferase, uridine 5'-diphospho-glucuronosyltransferase, transferrin and transthyretin, but also secreted human albumin, urea and blood urea nitrogen. Furthermore, SHED-derived HLA-ABC-positive cells were secondary transplanted into CCl4-treated mice. The donor cells homed into secondary recipient livers, and expressed hepatocyte paraffin 1 and human albumin, as well as HLA-ABC. The secondary transplantation recovered a liver dysfunction in secondary recipients.

CONCLUSIONS

This study indicates that transplanted SHED improve hepatic dysfunction and directly transform into hepatocytes without cell fusion in CCl4-treated mice, suggesting that SHED may provide a feasible cell source for liver regeneration.

Mesenchymal stem cells promote liver regeneration and prolong survival in small-for-size liver grafts: involvement of C-Jun N-terminal kinase, cyclin D1, and NF-κB

Background

The therapeutic potential of mesenchymal stem cells (MSCs) has been highlighted recently for treatment of acute or chronic liver injury, by possibly differentiating into hepatocyte-like cells, reducing inflammation, and enhancing tissue repair. Despite recent progress, exact mechanisms of action are not clearly elucidated. In this study, we attempted to explore whether and how MSCs protected hepatocytes and stimulated allograft regeneration in small-for-size liver transplantation (SFSLT).

Methods

SFSLT model was established with a 30% partial liver transplantation (30PLT) in rats. The differentiation potential and characteristics of bone marrow derived MSCs were explored in vitro. MSCs were infused transvenously immediately after graft implantation in therapy group. Expressions of apoptosis-, inflammatory-, anti-inflammatory-, and growth factor-related genes were measured by RT-PCR, activities of transcription factors AP-1 and NF-κB were analyzed by EMSA, and proliferative responses of the hepatic graft were evaluated by immunohistochemistry and western blot.

Results

MSCs were successfully induced into hepatocyte-like cells, osteoblasts and adipocytes in vitro. MSCs therapy could not only alleviate ischemia reperfusion injury and acute inflammation to promote liver regeneration, but also profoundly improve one week survival rate. It markedly up-regulated the mRNA expressions of HGF, Bcl-2, Bcl-XL, IL-6, IL-10, IP-10, and CXCR2, however, down-regulated TNF-α. Increased activities of AP-1 and NF-κB, as well as elevated expressions of p-c-Jun, cyclin D1, and proliferating cell nuclear antigen (PCNA), were also found in MSCs therapy group.

Conclusion

These data suggest that MSCs therapy promotes hepatocyte proliferation and prolongs survival in SFSLT by reducing ischemia reperfusion injury and acute inflammation, and sustaining early increased expressions of c-Jun N-terminal Kinase, Cyclin D1, and NF-κB.

Low frequency magnetic force augments hepatic differentiation of mesenchymal stem cells on a biomagnetic nanofibrous scaffold

Liver tissue engineering using polymeric nanofibrous scaffold and stem cells holds great promises for treating end-stage liver failures. The aim of this study was to evaluate hepatic trans-differentiation potential of human mesenchymal stem cells (hMSCs) on a biomagnetic electrospun nanofibrous scaffold fabricated from a blend of poly-L-lactide (PLLA), collagen and fibrin-rich blood clot, under the influence of a low frequency magnetic field. The scaffold was characterized for surface properties, biochemical and biomechanical parameters and bio-magnetic behaviour. Cell proliferation assay revealed that the scaffold was suitable for hMSCs adhesion and proliferation. Hepatic trans-differentiation potential of hMSCs was augmented on nanofibrous scaffold in magnetic field exposure group compared to control groups, as evident by strong expression of hepatocyte specific markers, albumin release, urea synthesis and presence of an inducible cytochrome P450 system. Our results conclude that biomagnetic scaffold of PLLA/collagen/blood clot augments hepatic trans-differentiation of hMSCs under magnetic field influence.