Stem cells from adipose tissue. Cell Mol Biol Lett. 2011;16:236-257. [PMID: 21394447 PMCID: PMC6275912 DOI: 10.2478/s11658-011-0005-0]

Trophic effects of mesenchymal stem cells in chondrocyte co-cultures are independent of culture conditions and cell sources

Earlier, we have shown that the increased cartilage production in pellet co-cultures of chondrocytes and bone marrow-derived mesenchymal stem cells (BM-MSCs) is due to a trophic role of the MSC in stimulating chondrocyte proliferation and matrix production rather than MSCs actively undergoing chondrogenic differentiation. These studies were performed in a culture medium that was not compatible with the chondrogenic differentiation of MSCs. In this study, we tested whether the trophic role of the MSCs is dependent on culturing co-culture pellets in a medium that is compatible with the chondrogenic differentiation of MSCs. In addition, we investigated whether the trophic role of the MSCs is dependent on their origins or is a more general characteristic of MSCs. Human BM-MSCs and bovine primary chondrocytes were co-cultured in a medium that was compatible with the chondrogenic differentiation of MSCs. Enhanced matrix production was confirmed by glycosaminoglycans (GAG) quantification. A species-specific quantitative polymerase chain reaction demonstrated that the cartilage matrix was mainly of bovine origin, indicative of a lack of the chondrogenic differentiation of MSCs. In addition, pellet co-cultures were overgrown by bovine cells over time. To test the influence of origin on MSCs' trophic effects, the MSCs isolated from adipose tissue and the synovial membrane were co-cultured with human primary chondrocytes, and their activity was compared with BM-MSCs, which served as control. GAG quantification again confirmed increased cartilage matrix production, irrespective of the source of the MSCs. EdU staining combined with cell tracking revealed an increased proliferation of chondrocytes in each condition. Irrespective of the MSC source, a short tandem repeat analysis of genomic DNA showed a decrease in MSCs in the co-culture over time. Our results clearly demonstrate that in co-culture pellets, the MSCs stimulate cartilage formation due to a trophic effect on the chondrocytes rather than differentiating into chondrocytes, irrespective of culture condition or origin. This implies that the trophic effect of MSCs in co-cultures is a general phenomenon with potential implications for use in cartilage repair strategies.

Adipose tissue-derived mesenchymal stem cell transplantation promotes hepatic regeneration after hepatic ischemia-reperfusion and subsequent hepatectomy in rats

BACKGROUND

Adipose tissue-derived mesenchymal stem cells (ADSCs) are an attractive source for regenerative medicine because they are easily accessible through minimally invasive methods. We investigated the efficacy of ADSC transplantation on outcome after hepatic ischemia-reperfusion and subsequent hepatectomy in rats.

METHODS

ADSCs were isolated from subcutaneous adipose tissue of rats. After clamping the hepatoduodenal ligament for 15 min, the rats were subjected to a 70% partial hepatectomy. After releasing the clamp, 2 × 10(6) ADSCs per rat were injected through the penile vein. Phosphate buffered saline was injected as a control. The parameters of hepatic regeneration, such as hepatic regeneration rate, mitotic index, and anti-proliferating cell nuclear antigen levels, were examined. Furthermore, the expression of hepatic regeneration-associated proteins and genes in the regenerating liver was determined.

RESULTS

The hepatic regeneration rate 2 d after hepatectomy was significantly greater in the ADSC transplanted group compared with the sham group. Mitotic index, anti-proliferating cell nuclear antigen levels, and other regeneration-associated proteins in the liver were significantly higher in the ADSC transplanted group than the sham group on 1 d after hepatectomy. A number of hepatic regeneration-associated genes also were significantly upregulated in the ADSC transplanted group.

CONCLUSIONS

These results indicate that ADSC transplantation may provide beneficial effects in the process of liver regeneration after hepatic ischemia-reperfusion and subsequent hepatectomy.

Optimising human mesenchymal stem cell numbers for clinical application: a literature review

Adult mesenchymal stem cells (MSCs) are being investigated further for their use in stem cell therapies. However, as they are found in very low numbers in adult tissue, expansion in vitro is required to produce desired MSC numbers for clinical application. The need for effective cell-based therapies is increasing due to a rise in the ageing population, increasing the prevalence of musculoskeletal disorders. This review investigates how factors, age and gender of donor, as well as seeding density can affect MSC expansion. Age and gender of donor have received mixed results from studies, whereas seeding density studies have produced consistent results for numerous MSC sources, favouring lower seeding densities. Further research is required to reduce the risk of infection, loss of cell characterisation in cell culture, and making cell-based therapies more cost effective through creating rapid expansion of MSCs regardless of patient factors.

Next generation nerve guides: materials, fabrication, growth factors, and cell delivery

Nerve guides are increasingly being used surgically to repair acute peripheral nerve injuries. This is not only due to an increase in the number of commercially available devices, but also clinical acceptance. However, regeneration distance is typically limited to 20-25 mm, in part due to the basic tubular design. A number of experimental studies have shown improvements in nerve regeneration distance when conduits incorporate coatings, internal scaffolds, topographical cues, or the delivery of support cells. Current studies on designing nerve guides for maximizing nerve regeneration focus both on cell-containing and cell-free devices, the latter being clinically attractive as "off the shelf" products. Arguably better results are obtained when conduits are used in conjunction with support cells (e.g., Schwann cells or stem cells) that can improve regeneration distance and speed of repair, and provide informative experimental data on how Schwann and neuronal cells respond in regenerating injured nerves. In this review we discuss the range of current nerve guides commercially available and appraise experimental studies in the context of the future design of nerve guides for clinical use.

Stem Cell Therapy: A New Treatment for Burns?

Stem cell therapy has emerged as a promising new approach in almost every medicine specialty. This vast, heterogeneous family of cells are now both naturally (embryonic and adult stem cells) or artificially obtained (induced pluripotent stem cells or iPSCs) and their fates have become increasingly controllable, thanks to ongoing research in this passionate new field. We are at the beginning of a new era in medicine, with multiple applications for stem cell therapy, not only as a monotherapy, but also as an adjunct to other strategies, such as organ transplantation or standard drug treatment. Regrettably, serious preclinical concerns remain and differentiation, cell fusion, senescence and signalling crosstalk with growth factors and biomaterials are still challenges for this promising multidisciplinary therapeutic modality. Severe burns have several indications for stem cell therapy, including enhancement of wound healing, replacement of damaged skin and perfect skin regeneration - incorporating skin appendages and reduced fibrosis -, as well as systemic effects, such as inflammation, hypermetabolism and immunosuppression. The aim of this review is to describe well established characteristics of stem cells and to delineate new advances in the stem cell field, in the context of burn injury and wound healing.

Perinatal sources of mesenchymal stem cells: Wharton's jelly, amnion and chorion

Recently, stem cell biology has become an interesting topic, especially in the context of treating diseases and injuries using transplantation therapy. Several varieties of human stem cells have been isolated and identified in vivo and in vitro. Ideally, stem cells for regenerative medical application should be found in abundant quantities, harvestable in a minimally invasive procedure, then safely and effectively transplanted to either an autologous or allogenic host. The two main groups of stem cells, embryonic stem cells and adult stem cells, have been expanded to include perinatal stem cells. Mesenchymal stem cells from perinatal tissue may be particularly useful in the clinic for autologous transplantation for fetuses and newborns, and after banking in later stages of life, as well as for in utero transplantation in case of genetic disorders.This review highlights the characteristics and therapeutic potential of three human mesenchymal stem cell types obtained from perinatal sources: Wharton's jelly, the amnion, and the chorion.

Effect of three common SNPs in 5'-flanking region of LEP and ADIPOQ genes on their expression in Polish obese children and adolescents

Genes encoding adipokines are considered as candidates for human obesity. In this study we analyzed the expression of leptin (LEP) and adiponectin (ADIPOQ) genes in relation to common 5′-flanking or 5′UTR variants: -2548G>A (LEP), 19A>G (LEP) and -11377C>G (ADIPOQ) in Polish obese children and adolescents. Relative transcription levels in the subcutaneous adipose tissue (real time RT–PCR) and serum protein concentrations (RIA) were measured in 48 obese subjects with known genotypes at three polymorphic sites and in five non-obese controls. None of the studied polymorphisms altered significantly the expression. Significantly elevated relative transcription levels of the LEP gene (P < 0.05) and serum leptin concentrations (P < 0.01) were recorded in obese patients, when compared with the non-obese controls, but such differences were not found for the ADIPOQ gene. Interestingly, the leptin to adiponectin protein concentration ratio (L/A) was approximately sevenfold higher in obese children and adolescents when compared with the non-obese controls (P < 0.001). Taking into consideration the observed relationship between the genotypes and the gene expression level we suggest that these SNPs are not conclusive markers for predisposition to obesity in Polish children and adolescents. On the other hand, we confirmed that the leptin to adiponectin gene expression ratio (L/A) is an informative index characterizing obesity.

Scalable robotic biofabrication of tissue spheroids

Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.