Application potential of human fetal stem/progenitor cells in cell therapy

In vitro and in vivo assessment of biocompatibility of AZ31 alloy as biliary stents: a preclinical approach

INTRODUCTION

Biomaterial technology due to its lack of or minimal side effects in tissues has great potential. Traditionally biomaterials used were cobalt-chromium, stainless steel and nitinol alloys. Biomaterials such as magnesium (Mg) and zinc (Zn) have good biocompatibility and consequently can be a potential material for medical implants. To date, the effects of AZ31 alloy stent on cell apoptosis are still unclear. The current investigation was designed to determine the effect of AZ31 alloy stent on necrosis and apoptosis of common bile duct (CBD) epithelial cells.

MATERIAL AND METHODS

We experimented with application of different concentrations of AZ31 alloy stent to primary mouse extrahepatic bile epithelial cells (MEBECs) and estimated the effect on apoptosis and necrotic cells. Apoptosis and pro-apoptosis expression were estimated through real-time PCR. For in vivo protocol, we used rabbits, implanted the AZ31 bile stent, and estimated its effect on the CBD. AZ31 (40%) concentration showed an effect on the apoptotic and necrotic cells.

RESULTS

Real-time PCR revealed that AZ31 (40%) concentration increased the apoptotic genes such as NF-κB, caspase-3, Bax and Bax/Bcl-2 ratio as compared to the control group. In the in vivo experiment, AZ31 alloy stents were implanted into the CBD and showed an effect on the alteration the hematological, hepatic and non-hepatic parameters.

CONCLUSIONS

To conclude, it can be stated that AZ31 induces apoptosis via alteration in genes including nuclear factor kappa-B (NF-κB), caspase-3, Bax and Bax/Bcl-2 ratio and improved the hematological, hepatic and non-hepatic parameters.

Conditions for Collection of Placental Tissue Samples for Culturing of Multipotent Mesenchymal Stromal Cells

Placentas from women aged 25-32 years with normal course of gestation were studied. It is essential to stick to certain methodological approaches for preparing viable multipotent mesenchymal stromal cell culture and to carry out morphological (macro and micro) evaluation of the chorionic villi, umbilical cords, and placentas. At stage I of the study, patients' histories, labor course, and examinations of the newborns should be analyzed to exclude women with genital and extragenital diseases. At stage II, it is essential to stick to special regulations and methods for collection of specimens of the cord, amnion, and placental tissue proper. Histological control of the placental structures collected for multipotent mesenchymal stromal cell culturing is obligatory.

Human embryonic mesenchymal stem cells alleviate pathologic changes of MRL/Lpr mice by regulating Th7 cell differentiation

Recent evidence indicates that mesenchymal stem cells (MSC) derived from early embryonic tissues have better therapeutic ability as compared with adult tissue-derived stem cells. In the present study, we transplanted human early embryonic MSC (hMSC) into MRL/Lpr mice via tail vein injection to observe the therapeutic efficacy of hMSC and their impact on T helper 17 (Th17) cell differentiation in MRL/Lpr mice. Animals in hMSC treatment group received hMSC (1 × 10⁶/200 μL) via the tail vein at the age of 16 and 19 weeks. We found that hMSC treatment prolonged the survival of MRL/Lpr mice without inducing tumorigenesis, reduced urine protein, and alleviated the renal pathologic changes. In addition, it reduced the proportion of Th17 cells in the spleen of MRL/Lpr mice and the serum interleukin 17 (IL-17) concentration. Our in vitro experiment also demonstrated that hMSC could secrete Th17 differentiation-related cytokines of PGE2, IL-10 and TGF-β, and IFN-γ stimulation up-regulated the secretion of these immune regulating factors. The results of the present study suggest that hMSC therapy could alleviate systemic and local renal lesions in MRL/Lpr mice, probably by secreting immune regulating factors and regulating Th17 cell differentiation in MRL/Lpr mice.

Fetal Renal Stem Cell Transplant in Nephrotic and Nonnephrotic Glomerulonephritis with Stage 2-4 Chronic Kidney Disease: Potential Effect on Proteinuria and Glomerular Filtration Rate

OBJECTIVES

Proteinuria is a major cause of glomerulosclerosis progression in glomerular diseases, and the development of end-stage renal disease is more rapid in nephrotic patients than in nonnephrotic ones. The renal parenchyma is less regenerable because it is a tissue consisting of renal cells. Thus, stem cells obtained from fetal kidney tissue might be effective for reducing proteinuria and delaying glomerulosclerosis in these patients.

MATERIALS AND METHODS

This report presents preliminary data from a prospective cohort study that included 17 patients with chronic glomerulonephritis in stage 2 to 4 chronic kidney disease who completed 3 visits during 1 year of follow-up. Fetal renal stem cells (multiple cells in suspension) were injected into the patient every 6 months. Patients were divided into 2 groups according to their nephrotic status, and 24-hour maximal proteinuria was recorded for at least 6 months (first group with proteinuria < 3.5 g/24 h, and second group with proteinuria > 3.5 g/24 h).

RESULTS

During follow-up, group 1 was observed to have stable hemoglobin and total protein levels but significantly decreased albumin levels and glomerular filtration rates. In group 2, total protein with serum albumin significantly increased, and proteinuria and glomerular filtration rates significantly decreased. There was no significant difference in glomerular filtration rate decline between groups.

CONCLUSIONS

Treatment with fetal renal stem cells significantly decreased proteinuria in nephrotic patients. However, this outcome also might have resulted from a reduction in glomerular filtration rate. Further studies with a larger number of patients and a control group would help to achieve better results that measure the efficacy of this treatment.

N-acetylcysteine-pretreated human embryonic mesenchymal stem cell administration protects against bleomycin-induced lung injury

INTRODUCTION

The transplantation of mesenchymal stem cells (MSCs) has been reported to be a promising approach in the treatment of acute lung injury. However, the poor efficacy of transplanted MSCs is one of the serious handicaps in the progress of MSC-based therapy. Therefore, the purpose of this study was to investigate whether the pretreatment of human embryonic MSCs (hMSCs) with an antioxidant, namely N-acetylcysteine (NAC), can improve the efficacy of hMSC transplantation in lung injury.

METHODS

In vitro, the antioxidant capacity of NAC-pretreated hMSCs was assessed using intracellular reactive oxygen species (ROS) and glutathione assays and cell adhesion and spreading assays. In vivo, the therapeutic potential of NAC-pretreated hMSCs was assessed in a bleomycin-induced model of lung injury in nude mice.

RESULTS

The pretreatment of hMSCs with NAC improved antioxidant capacity to defend against redox imbalances through the elimination of cellular ROS, increasing cellular glutathione levels, and the enhancement of cell adhesion and spreading when exposed to oxidative stresses in vitro. In addition, the administration of NAC-pretreated hMSCs to nude mice with bleomycin-induced lung injury decreased the pathological grade of lung inflammation and fibrosis, hydroxyproline content and numbers of neutrophils and inflammatory cytokines in bronchoalveolar lavage fluid and apoptotic cells, while enhancing the retention and proliferation of hMSCs in injured lung tissue and improving the survival rate of mice compared with results from untreated hMSCs.

CONCLUSIONS

The pretreatment of hMSCs with NAC could be a promising therapeutic approach to improving cell transplantation and, therefore, the treatment of lung injury.

VEGF-modified human embryonic mesenchymal stem cell implantation enhances protection against cisplatin-induced acute kidney injury

The implantation of mesenchymal stem cells (MSC) has been reported as a new technique to restore renal tubular structure and improve renal function in acute kidney injury (AKI). Vascular endothelial growth factor (VEGF) plays an important role in the renoprotective function of MSC. Whether upregulation of VEGF by a combination of MSC and VEGF gene transfer could enhance the protective effect of MSC in AKI is not clear. We investigated the effects of VEGF-modified human embryonic MSC (VEGF-hMSC) in healing cisplatin-injured renal tubular epithelial cells (TCMK-1) with a coculture system. We found that TCMK-1 viability declined 3 days after cisplatin pretreatment and that coculture with VEGF-hMSC enhanced cell protection via mitogenic and antiapoptotic actions. In addition, administration of VEGF-hMSC in a nude mouse model of cisplatin-induced kidney injury offered better protective effects on renal function, tubular structure, and survival as represented by increased cell proliferation, decreased cellular apoptosis, and improved peritubular capillary density. These data suggest that VEGF-modified hMSC implantation could provide advanced benefits in the protection against AKI by increasing antiapoptosis effects and improving microcirculation and cell proliferation.