Single high-dose intravenous injection of Wharton's jelly-derived mesenchymal stem cell exerts protective effects in a rat model of metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS) is a significant epidemiological problem worldwide. It is a pre-morbid, chronic and low-grade inflammatory disorder that precedes many chronic diseases. Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) could be used to treat MetS because they express high regenerative capacity, strong immunomodulatory properties and allogeneic biocompatibility. This study aims to investigate WJ-MSCs as a therapy against MetS in a rat model. METHODS: Twenty-four animals were fed with high-fat high-fructose (HFHF) diet ad libitum. After 16 weeks, the animals were randomised into treatment groups (n = 8/group) and received a single intravenous administration of vehicle, that is, 3 × 106 cells/kg or 10 × 106 cells/kg of WJ-MSCs. A healthy animal group (n = 6) fed with a normal diet received the same vehicle as the control (CTRL). All animals were periodically assessed (every 4 weeks) for physical measurements, serum biochemistry, glucose tolerance test, cardiovascular function test and whole-body composition. Post-euthanasia, organs were weighed and processed for histopathology. Serum was collected for C-reactive protein and inflammatory cytokine assay. RESULTS: The results between HFHF-treated groups and healthy or HFHF-CTRL did not achieve statistical significance (α = 0.05). The effects of WJ-MSCs were masked by the manifestation of different disease subclusters and continuous supplementation of HFHF diet. Based on secondary analysis, WJ-MSCs had major implications in improving cardiopulmonary morbidities. The lungs, liver and heart show significantly better histopathology in the WJ-MSC-treated groups than in the untreated CTRL group. The cells produced a dose-dependent effect (high dose lasted until week 8) in preventing further metabolic decay in MetS animals. CONCLUSIONS: The establishment of safety and therapeutic proof-of-concept encourages further studies by improving the current therapeutic model.

Safety study of allogeneic mesenchymal stem cell therapy in animal model.

Intravenous (IV) infusion of mesenchymal stem cells (MSCs) from nascent tissues like Wharton's Jelly of the umbilical cord is reported to offer therapeutic effects against chronic diseases. However, toxicological data essential for the clinical application of these cells are limited. Thus, this study aimed to determine the safety of IV infusion of Wharton's Jelly derived MSCs (WJ-MSCs) in rats. Fifteen male Sprague-Dawley rats were randomised into the control or treatment group. Each group received an equal volume of saline or WJ-MSC (10 × 106 cell/kg) respectively. The animals were evaluated for physical, biochemical and haematological changes at Week 0, 2, 4, 8 and 12 during the 12-week study. Acute toxicity was performed during Week 2 and sub-chronic toxicity during Week 12. At the end of the study, the relative weight of organs was calculated and histology was performed for lung, liver, spleen and kidney. The findings from physical, serum biochemistry and complete blood count demonstrated no statistically significant differences between groups. However, pathological evaluation reported minor inflammation in the lungs for all groups, but visible healing and resolution of inflammation were observed in the treatment group only. Additionally, the histological images of the treatment group had significantly improved pulmonary structures compared to the control group. In summary, the IV administration of WJ-MSC was safe in the rats. Further studies are needed to determine the long-term safety of the WJ-MSC in both healthy and diseased animal models.