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Yiwei Qiu - One of the best experts on this subject based on the ideXlab platform.
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Effect of indomethacin and lactoferrin on human tenocyte proliferation and collagen formation in vitro.
Biochemical and biophysical research communications, 2014Co-Authors: Yaonan Zhang, Yiwei Qiu, Xiao Wang, Andrew Carr, Jillian Cornish, Zhidao XiaAbstract:Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in patients with injuries and inflammation of tendon and ligament, and as post-surgical analgesics. The aim of this study is to investigate the effect of indomethacin, a classic NSAID and its combinational effect with an anabolic agent of skeletal tissue, lactoferrin, on the proliferation and collagen formation of human Tenocytes in vitro. A factorial experimental design was employed to study the dose-dependent effect of the combination of indomethacin and lactoferrin. The results showed that indomethacin at high concentration (100 μM) inhibited human tenocyte proliferation in culture medium with 1-10% fetal bovine serum (FBS) in vitro. Also, high dose of indomethacin inhibited the collagen formation of human Tenocytes in 1% FBS culture medium. Lactoferrin at 50-100 μg/ml promoted human tenocyte survival in serum-free culture medium and enhanced proliferation and collagen synthesis of human Tenocytes in 1% FBS culture medium. When 50-100 μg/ml lactoferrin was used in combination with 100-200 μM indomethacin, it partially rescued the inhibitory effects of indomethacin on human tenocyte proliferation, viability and collagen formation. To our knowledge, it is the first evidence that lactoferrin is anabolic to human Tenocytes in vitro and reverses potential inhibitory effects of NSAIDs on human Tenocytes.
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Effects of platelet derived growth factor BB and basic fibroblast growth factor on phenotype of Tenocytes and the mRNA expression of tenocyte phenotypic and differentiation markers
Chinese journal of experimental surgery, 2013Co-Authors: Yiwei Qiu, Liwei ZhuAbstract:Objective To evaluate the the changes of tenocyte phenotype and the expression of the phenotypic markers by adding platelet derived growth factor BB (PDGFBB) and basic fibroblast growth factor(bFGF) to human tenocyte in vitro culture.Methods Human Tenocytes were cultured in α-MEM medium by adding FBS at the concentration of 1％ and supplementing either/both PDGFBB and bFGF.Sirius red staining was employed to evaluate the characteristics of the Tenocytes cultured.Real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) technique was used to detect the mRNA expression of the tenocyte phenotypic and differentiation markers.Results The Tenocytes cultured for 14 days with 1％ FBS,50 μg/L PDGFBB + 50 μg/L bFGF showed less prominent collagen synthesis in comparison with those cultured in 10％ FBS.The Tenocytes cultured in the treated group also showed down-regulated mRNA expression of those markers [Scleraxis (Scx) 0.33,t =374.055 ; Tenomodulin (Tnmd) 0.003,t =28 199.418; Collagen type Ⅰ (Col Ⅰ) 0.57,t =164.195 ; Decorin (Den) 0.26,t =177.52).Conclusion These findings suggest that human Tenocytes could not only maintain their phenotype in the culture media with low concentration of FBS,but also keep the cells at less differentiated state,having this approach a suitable one for tendon tissue engineering. Key words: Tissue engineering; Tenocyte; Basic fibroblast growth factor; Differentiation
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Effects of platelet derived growth factorBB and basic fibroblast growth factor on proliferation and collagen synthesis of Tenocytes
Chinese journal of experimental surgery, 2013Co-Authors: Yiwei Qiu, Liwei ZhuAbstract:Objective To evaluate the effect of platelet derived growth factor (PDGF) BB and basic fibroblast growth factor (bFGF) on proliferation and collagen synthesis of Tenocytes in in vitro culture.Methods Human Tenocytes were cultured in α-MEM medium supplemented with fatal bovine serun (FBS) at various concentrations and both PDGFBB and bFGF.AlamarBlue was used to examine proleration of Tenocytes,and Sirius red staining was employed to evaluate the collagen synthesis of the cells studied.Results The Tenocytes cultured for 14 days with 1％ FBS + 50 μg/L PDGFBB +50 μg/L bFGF showed similar proliferation in comparison with those cultured in 10％ FBS (approximately 400％ increase).Tenocytes cultured in 50 μg/L PDGFBB + 50 μg/L bFGF showed significantly reduced collagen synthesis [(0.211 ±0.002) ng] in comparison with those cultured in 10％ FBS [(0.485 ±0.06g) ng].Conclusion These findings have demonstrated that in the presence of 50 μg/L PDGFBB + 50 μg/L bFGF in the culture medium,FBS usage can be reduced to 1％,which can not only obtain the same prolifertion rate as the 10％ FBS,but also inhibit collagen synthesis. Key words: Tenocyte; Platelet derived growth factor; Basic fibroblast growth factor; Proliferation; Collagen
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Development of a refined tenocyte expansion culture technique for tendon tissue engineering.
Journal of tissue engineering and regenerative medicine, 2012Co-Authors: Yiwei Qiu, Xiao Wang, Yaonan Zhang, Andrew Carr, Liwei Zhu, Zhidao Xia, Afsie SabokbarAbstract:The aim of this study was to efficiently expand less differentiated Tenocytes with minimum use of fetal bovine serum (FBS) for tenocyte-based tendon tissue engineering. To achieve this goal, human Tenocytes were cultured in different concentrations of FBS and combinations of growth factors PDGFBB, IGF-1 and bFGF. A number of growth factors were selected that could support tenocyte expansion at reduced differentiated state with minimum FBS usage. Results showed that the expansion of the Tenocytes cultured for 14 days with 1% FBS, 50 ng/ml PDGFBB and 50 ng/ml bFGF was similar to that cultured in the 10% FBS control group. The Tenocytes cultured in the treatment group showed significantly lower collagen synthesis and down-regulation of mRNA expression of tendon differentiation markers. Cell morphology confirmed that Tenocytes cultured in the growth factors had reduced collagen fibril formation compared to Tenocytes cultured in 10% FBS. Our findings confirm the feasibility of inducing human tenocyte expansion in vitro with the least amount of FBS usage, while controlling their differentiation until required. Copyright © 2012 John Wiley & Sons, Ltd.
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Development of a Refined Tenocyte Differentiation Culture Technique for Tendon Tissue Engineering
Cells tissues organs, 2012Co-Authors: Yiwei Qiu, Xiao Wang, Yaonan Zhang, R Rout, Andrew Carr, Liwei Zhu, Zhidao Xia, Afsie SabokbarAbstract:We have established that human Tenocytes can differentiate in the absence of exogenous fetal bovine serum (FBS) but in the presence of insulin-like growth factor-1 (IGF-1) and transforming growth factor-β3 (TGF-β3). The extent of tenocyte differentiation was assessed by examining cell survival, collagen synthesis, cell morphology and expression of tenocyte differentiation markers such as scleraxis (Scx), tenomodulin (Tnmd), collagen type I (Col-I) and decorin (Dcn). Our results indicate that 50 ng/ml IGF-1 and 10 ng/ml TGF-β3 (in the absence of FBS) were capable of maintaining in vitro human tenocyte survival in 14-day cultures. The extent of collagen synthesis and messenger ribonucleic acid expression of Scx, Tnmd, Col-I and Dcn were significantly upregulated in response to IGF-1 and TGF-β3. These findings have shown for the first time that human Tenocytes can be maintained in long-term culture, in serum-free conditions, making this approach a suitable one for the purpose of tendon tissue engineering.
Afsie Sabokbar - One of the best experts on this subject based on the ideXlab platform.
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Development of a refined tenocyte expansion culture technique for tendon tissue engineering.
Journal of tissue engineering and regenerative medicine, 2012Co-Authors: Yiwei Qiu, Xiao Wang, Yaonan Zhang, Andrew Carr, Liwei Zhu, Zhidao Xia, Afsie SabokbarAbstract:The aim of this study was to efficiently expand less differentiated Tenocytes with minimum use of fetal bovine serum (FBS) for tenocyte-based tendon tissue engineering. To achieve this goal, human Tenocytes were cultured in different concentrations of FBS and combinations of growth factors PDGFBB, IGF-1 and bFGF. A number of growth factors were selected that could support tenocyte expansion at reduced differentiated state with minimum FBS usage. Results showed that the expansion of the Tenocytes cultured for 14 days with 1% FBS, 50 ng/ml PDGFBB and 50 ng/ml bFGF was similar to that cultured in the 10% FBS control group. The Tenocytes cultured in the treatment group showed significantly lower collagen synthesis and down-regulation of mRNA expression of tendon differentiation markers. Cell morphology confirmed that Tenocytes cultured in the growth factors had reduced collagen fibril formation compared to Tenocytes cultured in 10% FBS. Our findings confirm the feasibility of inducing human tenocyte expansion in vitro with the least amount of FBS usage, while controlling their differentiation until required. Copyright © 2012 John Wiley & Sons, Ltd.
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Development of a Refined Tenocyte Differentiation Culture Technique for Tendon Tissue Engineering
Cells tissues organs, 2012Co-Authors: Yiwei Qiu, Xiao Wang, Yaonan Zhang, R Rout, Andrew Carr, Liwei Zhu, Zhidao Xia, Afsie SabokbarAbstract:We have established that human Tenocytes can differentiate in the absence of exogenous fetal bovine serum (FBS) but in the presence of insulin-like growth factor-1 (IGF-1) and transforming growth factor-β3 (TGF-β3). The extent of tenocyte differentiation was assessed by examining cell survival, collagen synthesis, cell morphology and expression of tenocyte differentiation markers such as scleraxis (Scx), tenomodulin (Tnmd), collagen type I (Col-I) and decorin (Dcn). Our results indicate that 50 ng/ml IGF-1 and 10 ng/ml TGF-β3 (in the absence of FBS) were capable of maintaining in vitro human tenocyte survival in 14-day cultures. The extent of collagen synthesis and messenger ribonucleic acid expression of Scx, Tnmd, Col-I and Dcn were significantly upregulated in response to IGF-1 and TGF-β3. These findings have shown for the first time that human Tenocytes can be maintained in long-term culture, in serum-free conditions, making this approach a suitable one for the purpose of tendon tissue engineering.
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proliferation and differentiation of human Tenocytes in response to platelet rich plasma an in vitro and in vivo study
Journal of Orthopaedic Research, 2012Co-Authors: Xiao Wang, Yiwei Qiu, Andrew Carr, Zhidao Xia, J T Triffitt, Afsie SabokbarAbstract:Platelet rich plasma (PRP) is the autologous plasma fraction with a platelet-rich cellular component which is enriched with a number of growth factors. Due to its availability and low cost, PRP has become an increasingly popular clinical tool as an alternative source of growth factors for various applications, for example, tendon regeneration but with limited success in clinical trials. The main objective of the current study was to determine whether activated PRP [i.e., platelet rich plasma-clot release (PRCR)] could be used to induce the proliferation and collagen synthesis in human tenocyte in vitro. The advantage of using PRCR is that the platelet-derived bioactive factors are more concentrated and could initiate a more rapid and accelerated healing response than PRP. Our results demonstrated that 10% PRCR treatment accelerated the extent of cell proliferation and collagen production by human Tenocytes in vitro. The expression of specific tenocyte markers were similar to conventional fetal bovine serum (FBS)-treated Tenocytes implanted in mice within 14 days of implantation in diffusion chambers. Moreover, relatively more collagen fibrils were evident in PRCR-treated Tenocytes in vivo as compared to 10% FBS-treated cells. Overall, our feasibility study has indicated that PRCR can induce human tenocyte proliferation and collagen synthesis which could be implemented for future tendon regeneration in reconstructive surgeries.
Zhidao Xia - One of the best experts on this subject based on the ideXlab platform.
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Effect of indomethacin and lactoferrin on human tenocyte proliferation and collagen formation in vitro.
Biochemical and biophysical research communications, 2014Co-Authors: Yaonan Zhang, Yiwei Qiu, Xiao Wang, Andrew Carr, Jillian Cornish, Zhidao XiaAbstract:Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in patients with injuries and inflammation of tendon and ligament, and as post-surgical analgesics. The aim of this study is to investigate the effect of indomethacin, a classic NSAID and its combinational effect with an anabolic agent of skeletal tissue, lactoferrin, on the proliferation and collagen formation of human Tenocytes in vitro. A factorial experimental design was employed to study the dose-dependent effect of the combination of indomethacin and lactoferrin. The results showed that indomethacin at high concentration (100 μM) inhibited human tenocyte proliferation in culture medium with 1-10% fetal bovine serum (FBS) in vitro. Also, high dose of indomethacin inhibited the collagen formation of human Tenocytes in 1% FBS culture medium. Lactoferrin at 50-100 μg/ml promoted human tenocyte survival in serum-free culture medium and enhanced proliferation and collagen synthesis of human Tenocytes in 1% FBS culture medium. When 50-100 μg/ml lactoferrin was used in combination with 100-200 μM indomethacin, it partially rescued the inhibitory effects of indomethacin on human tenocyte proliferation, viability and collagen formation. To our knowledge, it is the first evidence that lactoferrin is anabolic to human Tenocytes in vitro and reverses potential inhibitory effects of NSAIDs on human Tenocytes.
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Development of a refined tenocyte expansion culture technique for tendon tissue engineering.
Journal of tissue engineering and regenerative medicine, 2012Co-Authors: Yiwei Qiu, Xiao Wang, Yaonan Zhang, Andrew Carr, Liwei Zhu, Zhidao Xia, Afsie SabokbarAbstract:The aim of this study was to efficiently expand less differentiated Tenocytes with minimum use of fetal bovine serum (FBS) for tenocyte-based tendon tissue engineering. To achieve this goal, human Tenocytes were cultured in different concentrations of FBS and combinations of growth factors PDGFBB, IGF-1 and bFGF. A number of growth factors were selected that could support tenocyte expansion at reduced differentiated state with minimum FBS usage. Results showed that the expansion of the Tenocytes cultured for 14 days with 1% FBS, 50 ng/ml PDGFBB and 50 ng/ml bFGF was similar to that cultured in the 10% FBS control group. The Tenocytes cultured in the treatment group showed significantly lower collagen synthesis and down-regulation of mRNA expression of tendon differentiation markers. Cell morphology confirmed that Tenocytes cultured in the growth factors had reduced collagen fibril formation compared to Tenocytes cultured in 10% FBS. Our findings confirm the feasibility of inducing human tenocyte expansion in vitro with the least amount of FBS usage, while controlling their differentiation until required. Copyright © 2012 John Wiley & Sons, Ltd.
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Development of a Refined Tenocyte Differentiation Culture Technique for Tendon Tissue Engineering
Cells tissues organs, 2012Co-Authors: Yiwei Qiu, Xiao Wang, Yaonan Zhang, R Rout, Andrew Carr, Liwei Zhu, Zhidao Xia, Afsie SabokbarAbstract:We have established that human Tenocytes can differentiate in the absence of exogenous fetal bovine serum (FBS) but in the presence of insulin-like growth factor-1 (IGF-1) and transforming growth factor-β3 (TGF-β3). The extent of tenocyte differentiation was assessed by examining cell survival, collagen synthesis, cell morphology and expression of tenocyte differentiation markers such as scleraxis (Scx), tenomodulin (Tnmd), collagen type I (Col-I) and decorin (Dcn). Our results indicate that 50 ng/ml IGF-1 and 10 ng/ml TGF-β3 (in the absence of FBS) were capable of maintaining in vitro human tenocyte survival in 14-day cultures. The extent of collagen synthesis and messenger ribonucleic acid expression of Scx, Tnmd, Col-I and Dcn were significantly upregulated in response to IGF-1 and TGF-β3. These findings have shown for the first time that human Tenocytes can be maintained in long-term culture, in serum-free conditions, making this approach a suitable one for the purpose of tendon tissue engineering.
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proliferation and differentiation of human Tenocytes in response to platelet rich plasma an in vitro and in vivo study
Journal of Orthopaedic Research, 2012Co-Authors: Xiao Wang, Yiwei Qiu, Andrew Carr, Zhidao Xia, J T Triffitt, Afsie SabokbarAbstract:Platelet rich plasma (PRP) is the autologous plasma fraction with a platelet-rich cellular component which is enriched with a number of growth factors. Due to its availability and low cost, PRP has become an increasingly popular clinical tool as an alternative source of growth factors for various applications, for example, tendon regeneration but with limited success in clinical trials. The main objective of the current study was to determine whether activated PRP [i.e., platelet rich plasma-clot release (PRCR)] could be used to induce the proliferation and collagen synthesis in human tenocyte in vitro. The advantage of using PRCR is that the platelet-derived bioactive factors are more concentrated and could initiate a more rapid and accelerated healing response than PRP. Our results demonstrated that 10% PRCR treatment accelerated the extent of cell proliferation and collagen production by human Tenocytes in vitro. The expression of specific tenocyte markers were similar to conventional fetal bovine serum (FBS)-treated Tenocytes implanted in mice within 14 days of implantation in diffusion chambers. Moreover, relatively more collagen fibrils were evident in PRCR-treated Tenocytes in vivo as compared to 10% FBS-treated cells. Overall, our feasibility study has indicated that PRCR can induce human tenocyte proliferation and collagen synthesis which could be implemented for future tendon regeneration in reconstructive surgeries.
Alex Scott - One of the best experts on this subject based on the ideXlab platform.
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enhanced collagen type i synthesis by human Tenocytes subjected to periodic in vitro mechanical stimulation
BMC Musculoskeletal Disorders, 2014Co-Authors: Robert G. Mccormack, Alex Scott, Elise HuismanAbstract:Mechanical stimulation (e.g. slow heavy loading) has proven beneficial in the rehabilitation of chronic tendinopathy, however the optimal parameters of stimulation have not been experimentally determined. In this study of mechanically stimulated human Tenocytes, the influence of rest insertion and cycle number on (1) the protein and mRNA levels of type I and III collagen; (2) the mRNA levels of transforming growth factor beta (TGFB1) and scleraxis (SCXA); and (3) tenocyte morphology, were assessed. Human hamstring Tenocytes were mechanically stimulated using a Flexcell® system. The stimulation regimens were 1) continuous and 2) rest-inserted cyclic equiaxial strain at a frequency of 0.1 Hz for 100 or 1000 cycles. Data were normalized to unstimulated (non-stretched) control groups for every experimental condition. qPCR was performed to determine relative mRNA levels and quantitative immunocytochemistry image analysis was used to assess protein levels and cell morphology. Collagen type I mRNA level and pro-collagen protein levels were higher in Tenocytes that were subjected to rest-inserted mechanical stimulation, compared to continuous stretching (p < 0.05). Rest insertion and increased cycle number also had significant positive effects on the levels of mRNA for TGFB1 and SCXA (p < 0.05). There was no direct relation between cell morphology and gene expression, however mechanical stimulation, overall, induced a metabolically active tenocyte phenotype as evidenced by cells that on average demonstrated a decreased major-minor axis ratio (p < 0.05) with greater branching (p < 0.01). The incorporation of rest periods in a mechanical stretching regimen results in greater collagen type I synthesis. This knowledge may be beneficial in refining rehabilitation protocols for tendon injury.
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Mechanism of mast cell adhesion to human Tenocytes in vitro
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2014Co-Authors: Hayedeh Behzad, Shu-huei Tsai, Paulina Nassab, Rouhollah Mousavizadeh, Robert G. Mccormack, Alex ScottAbstract:Mast cells and fibroblasts are two key players involved in many fibrotic and degenerative disorders. In the present study we examined the nature of binding interactions between human mast cells and tendon fibroblasts (Tenocytes). In the mast cell-fibroblast co-culture model, mast cells were shown to spontaneously bind to Tenocytes, in a process that was partially mediated by α5β1 integrin receptors. The same receptors on mast cells significantly mediated binding of these cells to tissue culture plates in the presence of tenocyte-conditioned media; the tenocyte-derived fibronectin in the media was shown to also play a major role in these binding activities. Upon binding to Tenocytes or tissue culture plates, mast cells acquired an elongated phenotype, which was dependent on α5β1 integrin and tenocyte fibronectin. Additionally, tenocyte-derived fibronectin significantly enhanced mRNA expression of the adhesion molecule, THY1, by mast cells. Our data suggests that α5β1 integrin mediates binding of mast cells to human tenocyte and to tenocyte-derived ECM proteins, in particular fibronectin. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:9–16, 2015.
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EFFECTS OF MAST CELLS ON THE FUNCTION OF ISOLATED HUMAN Tenocytes
British Journal of Sports Medicine, 2013Co-Authors: Hayedeh Behzad, Alex ScottAbstract:Introduction Tendinopathy, a pathological condition caused by tendon overuse, adversely affects millions of people in athletic and occupational settings worldwide. The underlying molecular mechanisms in the development of tendinopathy are poorly understood, however, increased mast cell numbers have been detected in human patellar tendinopathy specimens. Mast cells are known to increase fibroblast proliferation and collagen production leading to fibrosis in some tissues. The present study was carried out to determine the effects of mast cells on isolated human tendon fibroblasts (Tenocytes) and explore a possible role for mast cells in the development of tendinopathy. Methods Primary human Tenocytes were isolated from hamstring tendons of healthy donors. Light and electron microscopy were used to examine a physical association between mast cells (HMC-1) and Tenocytes, in vitro. Collagen gel contraction assay was used to examine the effects of mast cells on isolated Tenocytes. Cell viability and proliferation was assessed by MTS assay. Gene expression was quantitated by qPCR. Results HMC-1 mast cells were shown by light and electron microscopy to physically bind to primary Tenocytes through adherent junctions. Immunostaining for stem cell factor (SCF), a mast cell growth factor, showed homogeneous expression of this protein on the surface of Tenocytes. Additionally, qPCR showed an increase in tenocyte SCF mRNA expression in the presence of mast cells. In other experiments, both mast cells and mast cell sonicates were shown to induce tenocyte mediated contraction of collagen gel, which appeared to be driven by TGF-β1. MTS assay showed a mast cell mediated increase in tenocyte survival and proliferation. Discussion These findings suggest that either through physical association with Tenocytes and/or release of mediators, mast cells could play a role in the regulation and activation of Tenocytes. Further studies are underway to investigate the molecular mechanisms of mast cell-tenocyte interactions and whether these could play a role in the pathogenesis of tendinopathy.
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substance p is a mechanoresponsive autocrine regulator of human tenocyte proliferation
PLOS ONE, 2011Co-Authors: Alex Scott, Ludvig J Backman, Gloria Fong, Gustav Andersson, Patrik DanielsonAbstract:It has been hypothesised that substance P (SP) may be produced by primary fibroblastic tendon cells (Tenocytes), and that this production, together with the widespread distribution of the neurokinin-1 receptor (NK-1 R) in tendon tissue, could play an important role in the development of tendinopathy, a condition of chronic tendon pain and thickening. The aim of this study was to examine the possibility of endogenous SP production and the expression of NK-1 R by human Tenocytes. Because tendinopathy is related to overload, and because the predominant tissue pathology (tendinosis) underlying early tendinopathy is characterized by tenocyte hypercellularity, the production of SP in response to loading/strain and the effects of exogenously administered SP on tenocyte proliferation were also studied. A cell culture model of primary human tendon cells was used. The vast majority of tendon cells were immunopositive for the tenocyte/fibroblast markers tenomodulin and vimentin, and immunocytochemical counterstaining revealed that positive immunoreactions for SP and NK-1 R were seen in a majority of these cells. Gene expression analyses showed that mechanical loading (strain) of tendon cell cultures using the FlexCell© technique significantly increased the mRNA levels of SP, whereas the expression of NK-1 R mRNA decreased in loaded as compared to unloaded tendon cells. Reduced NK-1 R protein was also observed, using Western blot, after exogenously administered SP at a concentration of 10−7 M. SP exposure furthermore resulted in increased cell metabolism, increased cell viability, and increased cell proliferation, all of which were found to be specifically mediated via the NK-1 R; this in turn involving a common mitogenic cell signalling pathway, namely phosphorylation of ERK1/2. This study indicates that SP, produced by Tenocytes in response to mechanical loading, may regulate proliferation through an autocrine loop involving the NK-1 R.
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tenocyte responses to mechanical loading in vivo a role for local insulin like growth factor 1 signaling in early tendinosis in rats
Arthritis & Rheumatism, 2007Co-Authors: Alex Scott, Jillianne Leigh Cook, David A Hart, David C Walker, Vincent Duronio, Karim M KhanAbstract:Objective To investigate tenocyte regulatory events during the development of overuse supraspinatus tendinosis in rats. Methods Supraspinatus tendinosis was induced by running rats downhill at 1 km/hour for 1 hour a day. Tendons were harvested at 4, 8, 12, and 16 weeks and processed for brightfield, polarized light, or transmission electron microscopy. The development of tendinosis was assessed semiquantitatively using a modified Bonar histopathologic scale. Apoptosis and proliferation were examined using antibodies against fragmented DNA or proliferating cell nuclear antigen, respectively. Insulin-like growth factor 1 (IGF-1) expression was determined by computer-assisted quantification of immunohistochemical reaction. Local IGF-1 signaling was probed using antibodies to phosphorylated insulin receptor substrate 1 (IRS-1) and ERK-1/2. Results Tendinosis was present after 12 weeks of downhill running and was characterized by tenocyte rounding and proliferation as well as by glycosaminoglycan accumulation and collagen fragmentation. The proliferation index was elevated in CD90+ Tenocytes in association with tendinosis and correlated with increased local IGF-1 expression by Tenocytes and phosphorylation of IRS-1 and ERK-1/2. Both apoptosis and cellular inflammation were absent at all time points. Conclusion In this animal model, early tendinosis was associated with local stimulation of Tenocytes rather than with extrinsic inflammation or apoptosis. Our data suggest a role for IGF-1 in the load-induced tenocyte responses during the pathogenesis of overuse tendon disorders.
Jong-hwei S. Pang - One of the best experts on this subject based on the ideXlab platform.
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Low-level laser irradiation stimulates tenocyte proliferation in association with increased NO synthesis and upregulation of PCNA and cyclins.
Lasers in medical science, 2014Co-Authors: Wen-chung Tsai, Hsiangning Chang, Miao-sui Lin, Ju-wen Cheng, Jean-lon Chen, Chen-yin Chen, Yu-hsin Liao, Jong-hwei S. PangAbstract:Low-level laser therapy is commonly used to treat tendinopathy or tendon injury. Tendon healing requires tenocyte migration to the repair site, followed by proliferation and synthesis of the extracellular matrix. There are few evidence to elucidate that low-level laser promote tenocyte proliferation. This study was designed to determine the effect of laser on tenocyte proliferation. Furthermore, the association of this effect with secretion of nitric oxide (NO) and the expressions of proliferating cell nuclear antigen (PCNA) and cyclins D1, E, A, and B1 was investigated. Tenocytes intrinsic to rat Achilles tendon were treated with low-level laser (660 nm). Tenocyte proliferation was evaluated by MTT assay and immunocytochemistry with Ki-67 stain. NO in the conditioned medium was measured by ELISA. Western blot analysis was used to evaluate the protein expressions of PCNA and cyclins D1, E, A, and B1. The results revealed that Tenocytes proliferation was enhanced dose dependently by laser. NO secretion was increased after laser treatment. PCNA and cyclins E, A, and B1 were upregulated by laser. In conclusion, low-level laser irradiation stimulates tenocyte proliferation in a process that is mediated by upregulation of NO, PCNA, and cyclins E, A, and B1.
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Low-Level Laser Irradiation Stimulates Tenocyte Migration with Up-Regulation of Dynamin II Expression
PLOS ONE, 2012Co-Authors: Wen-chung Tsai, Jong-hwei S. Pang, Ying-hsun Chen, Fang-chen LiangAbstract:Low-level laser therapy (LLLT) is commonly used to treat sports-related tendinopathy or tendon injury. Tendon healing requires tenocyte migration to the repair site, followed by proliferation and synthesis of the extracellular matrix. This study was designed to determine the effect of laser on tenocyte migration. Furthermore, the correlation between this effect and expression of dynamin 2, a positive regulator of cell motility, was also investigated. Tenocytes intrinsic to rat Achilles tendon were treated with low-level laser (660 nm with energy density at 1.0, 1.5, and 2.0 J/cm2). Tenocyte migration was evaluated by an in vitro wound healing model and by transwell filter migration assay. The messenger RNA (mRNA) and protein expressions of dynamin 2 were determined by reverse transcription/real-time polymerase chain reaction (real-time PCR) and Western blot analysis respectively. Immunofluorescence staining was used to evaluate the dynamin 2 expression in Tenocytes. Tenocytes with or without laser irradiation was treated with dynasore, a dynamin competitor and then underwent transwell filter migration assay. In vitro wound model revealed that more Tenocytes with laser irradiation migrated across the wound border to the cell-free zone. Transwell filter migration assay confirmed that tenocyte migration was enhanced dose-dependently by laser. Real-time PCR and Western-blot analysis demonstrated that mRNA and protein expressions of dynamin 2 were up-regulated by laser irradiation dose-dependently. Confocal microscopy showed that laser enhanced the expression of dynamin 2 in cytoplasm of Tenocytes. The stimulation effect of laser on Tenocytes migration was suppressed by dynasore. In conclusion, low-level laser irradiation stimulates tenocyte migration in a process that is mediated by up-regulation of dynamin 2, which can be suppressed by dynasore.
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the effect of aging on migration proliferation and collagen expression of Tenocytes in response to ciprofloxacin
Journal of Orthopaedic Research, 2012Co-Authors: Hsiangning Chang, Wen-chung Tsai, Jong-hwei S. Pang, Miao-sui Lin, Carl P.c. Chen, Yun-ming YangAbstract:Quinolone-induced tendinopathy or tendon rupture tends to be age-related. However, the synergistic effects of quinolone and aging on Tenocytes remained to be explored. Tenocytes intrinsic to rat Achilles tendon from two age groups (young: 2 months; and near senescent (old): 24 months) were treated with ciprofloxacin. Tenocyte migration and proliferation were assessed by transwell filter migration assay and MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay, respectively. Messenger RNA and protein expressions of types I and III collagen were determined by reverse transcription-polymerase chain reaction (RT/PCR) and Western blot analysis, respectively. Transwell filter migration assay revealed that ciprofloxacin inhibited Tenocytes migration, which became more significant in old Tenocytes (p < 0.05). The results of MTT assay revealed that Tenocytes proliferation decreased after ciprofloxacin treatment (p < 0.05), which also became more significant in old Tenocytes. The results of RT-PCR and Western blot analysis revealed that mRNA and protein expressions of type I collagen remained unchanged in either young or old Tenocytes with ciprofloxacin treatment, whereas the expressions of type III collagen were down-regulated by ciprofloxacin, which was more significant in old Tenocytes. In conclusion, aging potentiated the ciprofloxacin-mediated inhibition of migration, proliferation, and expression of type III collagen of Tenocytes. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:764–768, 2012
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The effect of aging on migration, proliferation, and collagen expression of Tenocytes in response to ciprofloxacin.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2011Co-Authors: Hsiangning Chang, Wen-chung Tsai, Jong-hwei S. Pang, Miao-sui Lin, Carl P.c. Chen, Yun-ming YangAbstract:Quinolone-induced tendinopathy or tendon rupture tends to be age-related. However, the synergistic effects of quinolone and aging on Tenocytes remained to be explored. Tenocytes intrinsic to rat Achilles tendon from two age groups (young: 2 months; and near senescent (old): 24 months) were treated with ciprofloxacin. Tenocyte migration and proliferation were assessed by transwell filter migration assay and MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay, respectively. Messenger RNA and protein expressions of types I and III collagen were determined by reverse transcription-polymerase chain reaction (RT/PCR) and Western blot analysis, respectively. Transwell filter migration assay revealed that ciprofloxacin inhibited Tenocytes migration, which became more significant in old Tenocytes (p
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decreased proliferation of aging Tenocytes is associated with down regulation of cellular senescence inhibited gene and up regulation of p27
Journal of Orthopaedic Research, 2011Co-Authors: Wen-chung Tsai, Fang-chen Liang, Hsiangning Chang, Chenghsiu Chien, Jong-hwei S. PangAbstract:Symptomatic tendinopathy tends to be age-related. However, the molecular mechanisms of ageing and its effects on tenocyte proliferation and cell cycle progression are unknown. We examined Tenocytes from Achilles tendons in rats from three age groups (young, 2 months; middle-aged, 12 months, and near senescence, 24 months). Tenocyte proliferation was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Senescence-associated β-galactosidase (SA β-gal) staining was performed in all groups of Tenocytes. mRNA and protein expression of cellular senescence-inhibited gene (CSIG) and p27 was measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. The results of MTT assay revealed that tenocyte proliferation decreased with age (p < 0.05). Cell cycle progression was arrested at G0/G1 phase in senescent Tenocytes. More senescent Tenocytes expressed SA β-gal than young Tenocytes did. By RT-PCR and Western blot analysis, the gene and protein expression of CSIG was found to be down-regulated, whereas that of p27 was up-regulated with age. In conclusion, the proliferation of Tenocytes declines with age and is associated with the down-regulation of CSIG and up-regulation of p27. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1598–1603, 2011
