Asian Spine J.  2019 Oct;13(5):705-712. 10.31616/asj.2018.0257.

Comparison of Transforming Growth Factor-Beta1 and Lovastatin on Differentiating Mesenchymal Stem Cells toward Nucleus Pulposus-like Phenotype: An In Vitro Cell Culture Study

• Yang SH
• Yang KC
• Chen CW
• Huang TC
• Sun YH
• Hu MH

• KMID: 2461998
• DOI: http://doi.org/10.31616/asj.2018.0257

Abstract

STUDY DESIGN: In Vitro cell culture study. PURPOSE: This study aims to investigate the impact of transforming growth factor-beta1 (TGF-β1) and lovastatin on differentiating human mesenchymal stem cells (MSCs) toward nucleus pulposus (NP)-like phenotype. OVERVIEW OF LITERATURE: MSCs offer a cell source to the cell-based therapy for intervertebral disc degeneration. TGF-β1 is used to induce MSCs to differentiate into NP-like cells; however, an undesired expression of collagen type I has been reported. Statins reportedly stimulate expression of bone morphogenetic protein-2 (BMP-2) and promote the chondrogenic phenotype to NP cells. However, the effects of statins with or without TGF-β1 on the differentiation of MSCs into NP-like cells remain unclear.
METHODS
Human MSCs were treated with TGF-β1 alone, lovastatin alone, and simultaneous or sequential treatment with TGF-β1 and lovastatin. After the proposed stimulation, the total RNA was extracted to assess the expression profile of NP cells-specific genes. Hematoxylin-eosin staining was used for examining the microscopic morphology. Furthermore, we detected the syntheses of S-100 protein, aggrecan, and collagen type II in the extracellular matrix using immunohistochemical staining.
RESULTS
Simultaneous or sequential treatment of TGF-β1 and lovastatin could further augment the BMP-2 overexpression compared with lovastatin-alone treatment. However, the mRNA expression of aggrecan and collagen type II was not compatible with the expression level of BMP-2. Immunohistochemical studies revealed compatible production of aggrecan, collagen type II, and S-100 protein in all three groups treated with lovastatin. Cells in groups treated with lovastatin were less populated than that in the group treated with TGF-β1 alone.
CONCLUSIONS
This study demonstrates a promising role of lovastatin in inducing human MSCs into NP-like cells. However, further optimization of cell density before lovastatin treatment, treatment duration, and combination with TGF-β1 are warranted to attain better stimulatory effects.

Keyword

Spine; Intervertebral disc degeneration; Mesenchymal stem cells; Nucleus pulposus-like cells; Lovastatin

MeSH Terms

Aggrecans
Cell Count
Cell Culture Techniques*
Collagen Type I
Collagen Type II
Extracellular Matrix
Humans
Hydroxymethylglutaryl-CoA Reductase Inhibitors
In Vitro Techniques*
Intervertebral Disc Degeneration
Lovastatin*
Mesenchymal Stromal Cells*
Phenotype*
RNA
RNA, Messenger
S100 Proteins
Spine
Aggrecans
Collagen Type I
Collagen Type II
Lovastatin
RNA
RNA, Messenger
S100 Proteins