Overexpression of TGF-β1 enhances chondrogenic differentiation and proliferation of human synovium-derived stem cells

Genetic Engineering of Mesenchymal Stem Cells for Regenerative Medicine

Mesenchymal stem cells (MSCs), which can be obtained from various organs and easily propagated in vitro, are one of the most extensively used types of stem cells and have been shown to be efficacious in a broad set of diseases. The unique and highly desirable properties of MSCs include high migratory capacities toward injured areas, immunomodulatory features, and the natural ability to differentiate into connective tissue phenotypes. These phenotypes include bone and cartilage, and these properties predispose MSCs to be therapeutically useful. In addition, MSCs elicit their therapeutic effects by paracrine actions, in which the metabolism of target tissues is modulated. Genetic engineering methods can greatly amplify these properties and broaden the therapeutic capabilities of MSCs, including transdifferentiation toward diverse cell lineages. However, cell engineering can also affect safety and increase the cost of therapy based on MSCs; thus, the advantages and disadvantages of these procedures should be discussed. In this review, the latest applications of genetic engineering methods for MSCs with regenerative medicine purposes are presented.

Genetically modified chondrocytes expressing TGF-β1: a revolutionary treatment for articular cartilage damage?

INTRODUCTION

Currently, joint arthroplasty remains the only definitive management of osteoarthritis, while other treatment modalities only provide temporary and symptomatic relief. The use of genetically engineered chondrocytes is currently undergoing clinical trials. Specifically, it has been designed to induce cartilage growth and differentiation in patients with degenerative arthritis, with the aim to play a curative role in the disease process.

AREAS COVERED

This treatment involves the incorporation of TGF-β1, which has been determined to play an influential role in chondrogenesis and extracellular matrix synthesis. Using genetic manipulation and viral transduction, TGF-β1 is incorporated into human chondrocytes and administered in a minimally invasive fashion directly to the affected joint. Following a database literature search, we evaluated the current evidence on this product and its outcomes. Furthermore, we also briefly reviewed other treatments developed for chondrogenesis and cartilage regeneration for comparison.

EXPERT OPINION

This treatment method has sustained positive effects on functional outcomes and cartilage growth in initial trials. It allows administration in a minimally invasive manner that does not require extended recovery time. Although several treatment modalities are currently under investigation and appear promising, we hope that these effects can be sustained in further studies. Ultimately, we anticipate that the results may be reproducible in many clinical settings and allow us to effectively treat cartilage damage in patients with degenerative arthritis.

The role of growth factors in stem cell-directed chondrogenesis: a real hope for damaged cartilage regeneration

PURPOSE

The use of stem cells in regenerative medicine offers hope to treat numerous orthopaedic disorders, including articular cartilage defects. Although much research has been carried out on chondrogenesis, this complicated process is still not well understood and much more research is needed. The present review provides an overview of the stages of chondrogenesis and describes the effects of various growth factors, which act during the multiple steps involved in stem cell-directed differentiation towards chondrocytes.

METHODS

The current literature on stem cell-directed chondrogenesis, in particular the role of members of the transforming growth factor-β (TGF-β) superfamily-TGF-βs, bone morphogenetic proteins (BMPs) and fibroblast growth factors (FGFs)-is reviewed and discussed.

RESULTS

Numerous studies have reported the chondrogenic potential of both adult- and embryonic-like stem cells and the role of growth factors in programming differentiation of these cells towards chondrocytes. Mesenchymal stem cells (MSCs) are adult multipotent stem cells, whereas induced pluripotent stem cells (iPSC) are reprogrammed pluripotent cells. Although better understanding of the processes involved in the development of cartilage tissues is necessary, both cell types may be of value in the clinical treatment of cartilage injuries or osteoarthritic cartilage lesions.

CONCLUSIONS

MSCs and iPSCs both present unique characteristics. However, at present, it is still unclear which cell type is most suitable in the treatment of cartilage injuries.