Reexpression of aggrecan and type II collagen genes in dedifferentiated adult human articular chondrocytes (AHAC) in suspension culture varied widely depending on the specific lot of bovine serum used to supplement the culture medium. Some lots of serum provided strong induction of aggrecan and type II collagen expression by AHAC while others did not stimulate significant production of these hyaline cartilage extracellular matrix molecules even following several weeks in culture. Addition of 50 ng/ml insulin-like growth factor-I (IGF-I) to a deficient serum lot significantly enhanced its ability to induce aggrecan and type II collagen mRNA. Given this observation, IGF-I and other growth factors were tested in defined serum-free media for their effects on the expression of these genes. Neither IGF-I nor insulin nor transforming growth factor beta (TGF-beta) alone stimulated induction of aggrecan or type II collagen production by dedifferentiated AHAC. However, TGF-beta 1 or TGF-beta 2 combined with IGF-I or insulin provided a strong induction as demonstrated by RNase protection and immunohistochemical assays. Interestingly, type I collagen, previously shown to be downregulated in serum supplemented suspension cultures of articular chondrocytes, persisted for up to 12 weeks in AHAC cultured in defined medium supplemented with TGF-beta and IGF-I.
"It counteracts NO production induced by IL1 . In addition, TGFß is able to increase the production of essential cartilage matrix molecules such as aggrecan and type II collagen  , and prevent loss of proteoglycan in articular cartilage during experimental OA [57,60–62]. TGFß also functions as anti-arthritic  and is able to block inflammation in vivo . "
[Show abstract][Hide abstract] ABSTRACT: Transforming growth factor beta (TGFb) is a major signalling pathway in joints. This superfamilly is involved in numerous cellular processes in cartilage. Usually, they are considered to favor chondrocyte differentiation and cartilage repair. However, other studies show also deleterious effects of TGFb which may induce hypertrophy. This may be explained at least in part by alteration of TGFb signaling pathways in aging chondrocytes. This review focuses on the functions of TGFb in joints and the regulation of its signaling mediators (receptors, Smads) during aging and osteoarthritis.
Aging and Disease 12/2014; 5(6):394-405. DOI:10.14336/AD.2014.0500394 · 3.07 Impact Factor
"In addition, adhering various GFs on the surface of our nanofibers increased their regenerative potential. bFGF, IGF-1, and TGF-β2 may stimulate angiogenesis, fibroblast proliferation, and collagen synthesis, thus enhancing tissue stability.35–37 Their concentration ratio and their positive effect on cultivated cells were evaluated in our group by Filová et al.38 "
[Show abstract][Hide abstract] ABSTRACT: Incisional hernia affects up to 20% of patients after abdominal surgery. Unlike other types of hernia, its prognosis is poor, and patients suffer from recurrence within 10 years of the operation. Currently used hernia-repair meshes do not guarantee success, but only extend the recurrence-free period by about 5 years. Most of them are nonresorbable, and these implants can lead to many complications that are in some cases life-threatening. Electrospun nanofibers of various polymers have been used as tissue scaffolds and have been explored extensively in the last decade, due to their low cost and good biocompatibility. Their architecture mimics the natural extracellular matrix. We tested a biodegradable polyester poly-ε-caprolactone in the form of nanofibers as a scaffold for fascia healing in an abdominal closure-reinforcement model for prevention of incisional hernia formation. Both in vitro tests and an experiment on a rabbit model showed promising results.
International Journal of Nanomedicine 07/2014; 9(1):3263-77. DOI:10.2147/IJN.S63095 · 4.38 Impact Factor
"In the present study, we demonstrate that combined overexpression of IGF-1 and FGF-2 within ASCs via adenoviral mediated-gene transfer significantly enhanced the chondrogenic differentiation after 28 days in an aggregate culture system in vitro, greater than with IGF-1, FGF-2, TGF-β1, SOX9 alone or in other combination. While previous studies have analyzed the effects of these factors on chondrogenesis using MSCs  or cartilage repair using chondrocytes [31,32], there has been no study assessing combination of all of these growth and transcriptional factors on chondrogenesis using ASCs. "
[Show abstract][Hide abstract] ABSTRACT: Adipose derived mesenchymal stem cells (ASCs) have the potential to differentiate into cartilage under stimulation with some reported growth and transcriptional factors, which may constitute an alternative for cartilage replacement approaches. In this study, we analyzed the in vitro chondrogenesis of ASCs transduced with adenoviral vectors encoding the factors Insulin-like growth factor-1 (IGF-1), Transforming growth factor-b beta1 (TGF-beta1), Fibroblast growth factor 2 (FGF-2), and Sex determining region Y-box 9 (SOX9) either alone or in combinations.
Aggregate cultures of characterized ovine ASCs were transduced with 100 multiplicity of infections (MOIs) of Ad.IGF-1, Ad.TGF-beta1, Ad.FGF-2, and Ad.SOX9 alone or in combination. These were harvested at various time points for detection of cartilage-specific genes expression by quantitative real time PCR (qRT-PCR) or after 14 and 28 days for histologic and biochemical analyses detecting proteoglycans, collagens (II, I and X), and total sulfated glycosaminoglycans (GAGs) and collagen content, respectively.
qRT-PCR expression analyses showed that co-expression of IGF-1 and FGF-2 resulted in higher significant expression levels of aggrecan, biglycan, cartilage-matrix, proteoglycan, and collagen II (All with P = <0.001 at 28 days). Aggregates co-transduced with Ad.IGF-1/Ad.FGF-2 showed a selective expression of proteoglycans and collagen type II, with limited expression of collagens I and X demonstrated by histological analyses, and had significantly greater GAGs and collagen production than the positive control (P= <0.001). Western blot analyses also demonstrated for this combination, increased expression of collagen II, while expression of collagens I and X were undetectable and limited, respectively.
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