Differential regulation of gene expression in isolated tendon fascicles exposed to cyclic tensile strain in vitro

Mechanical stimulus is a regulator of tenocyte metabolism. The present study investigated temporal regulation of the expression of selected genes by tenocytes in isolated fascicles subjected to tensile strain in vitro. Cyclic tensile strain with a 3% amplitude superimposed on a 2% static strain was provided for 10 min, followed by either an unstrained period or continuous cyclic strain until the end of a 24-h incubation period. mRNA expression of selected anabolic and catabolic genes were evaluated with quantitative PCR at 10 min, 1 h, 6 h, and 24 h. The application of 6-h cyclic strain significantly upregulated type III collagen mRNA expression in strained fascicles compared with unstrained controls, but no alterations were observed in mRNA expression of type I collagen and biglycan. Significant downregulation in the expression of the decorin core protein was observed in fascicles subjected to 24-h cyclic strain. MMP3 and MMP13 expression levels were upregulated by the application of 10 min of cyclic strain, followed by a progressive downregulation until the end of the incubation period in both the absence and the presence of the continuing cyclic strain. Accordingly, alterations in the expression of anabolic genes were limited to the upregulation of type III collagen by prolonged exposure to cyclic strain, whereas catabolic genes were upregulated by a small number of strain cycles and downregulated by a prolonged cyclic strain. These findings demonstrate distinctive patterns of mechanoregulation for anabolic and catabolic genes and help our understanding of tenocyte response to mechanical stimulation.

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Separation of the Binding Step from the Collagen Platelet Reaction

10.1055/s-0039-1682724 ◽

1977 ◽

Author(s):

P.L. Kronick ◽

S.A. Jimenez

Keyword(s):

Type I Collagen ◽

Specific Activity ◽

Adenine Nucleotides ◽

High Specific Activity ◽

Type Iii Collagen ◽

Type I ◽

Type Iii ◽

Valid Comparison ◽

Platelet Reaction

Determination of activity of most agents in stimulating platelets to aggregate or release adenine nucleotides is conveniently done by titrating the platelet reaction with the agent. Platelets have previously been titrated with different types of collagen (types I, II, and III) in this way to compare the activities of the collagens. It has been concluded that the order of activity is type III>I>II. Whether this order is due to differences in binding was not obvious from these experiments because the binding was not determined directly. We have developed a method of comparing activities by measuring the targeted dose for each point in the titration - the amount of collagen which actually binds to platelets. The collagens used in these experiments were prepared in vitro from embryonic chick tissue to give labelled products of extremely high specific activity without structural alteration. We find that type I collagen is at least 20 times as active as previously reported, and that the activity of Type III collagen is not significantly higher when the amounts bound are taken into account. The fraction of the labelled tendon collagen which was bound to platelets was identified as type I by its hydroxyproline/proline ratio. Direct measurement of the bound fraction in dose-response studies is required for valid comparison of collagen activities.

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Antiaging Properties of Exosomes from Adipose-Derived Mesenchymal Stem Cells in Photoaged Rat Skin

BioMed Research International ◽

10.1155/2020/6406395 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Jun-Xian Liang ◽

Xuan Liao ◽

Sheng-Hong Li ◽

Xiao Jiang ◽

Ze-Hua Li ◽

...

Keyword(s):

Stem Cells ◽

Mrna Expression ◽

Real Time ◽

Type I Collagen ◽

Ultraviolet B ◽

Type Iii Collagen ◽

Type I ◽

Type Iii ◽

Photoaged Skin ◽

Dermal Thickness

Adipose-derived stem cells (ADSCs) have been documented as possible candidates for skin rejuvenation. However, the effects of ADSC-derived exosomes on photoaged skin remain to be fully elucidated. This study was aimed at determining the antiaging effects of ADSC-derived exosomes on photoaged skin. Human ADSCs were isolated from the adipose tissue of healthy women and cultured in vitro. Then, exosomes were extracted from the cultured ADSCs, purified by ultracentrifugation, and verified by examination of cell morphology using transmission electron microscopy and the identification of specific biomarkers. Meanwhile, the optimal exosome concentration and treatment time were selected. The photoaged skin model was created by subjecting Sprague-Dawley rats to ultraviolet B radiation. Exosomes were injected into the photoaged skin in a single therapeutic dose. The thickness of the epidermis and dermis was observed by HE staining. The relative mRNA expression of type I collagen, type III collagen, and matrix metalloproteinases (MMP-1 and MMP-3) was determined by real-time PCR. In the rat model of photoaged skin, the injected exosomes markedly decreased the epidermal thickness and increased the dermal thickness of the photoaged skin 7 days after treatment. Moreover, the proportion of the stratum corneum of the epidermis was decreased. Furthermore, real-time RT-PCR showed that the mRNA expression of type I collagen was increased and that of type III collagen, MMP-1, and MMP-3 was decreased. Our results demonstrate that ADSC-derived exosome treatment could significantly improve skin photodamage and that ADSC-derived exosomes may be a potential agent for photoaged skin treatment.

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Effect of Amplitude and Frequency of Cyclic Tensile Strain on the Inhibition of MMP-1 mRNA Expression in Tendon Cells: An In Vitro Study

Connective Tissue Research ◽

10.1080/03008200390215881 ◽

2003 ◽

Vol 44 (3-4) ◽

pp. 181-187 ◽

Cited By ~ 71

Author(s):

Michael Lavagnino ◽

Steven P. Arnoczky ◽

Tao Tian ◽

Zachary Vaupel

Keyword(s):

Mrna Expression ◽

Tensile Strain ◽

In Vitro Study ◽

Vitro Study ◽

Cyclic Tensile Strain ◽

Tendon Cells

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Basic fibroblast growth factor modulates proliferation and collagen expression in urinary bladder smooth muscle cells

AJP Renal Physiology ◽

10.1152/ajprenal.00107.2007 ◽

2007 ◽

Vol 293 (4) ◽

pp. F1007-F1017 ◽

Cited By ~ 39

Author(s):

Masaaki Imamura ◽

Akihiro Kanematsu ◽

Shingo Yamamoto ◽

Yu Kimura ◽

Isao Kanatani ◽

...

Keyword(s):

Smooth Muscle ◽

Type I Collagen ◽

Type Iii Collagen ◽

Type I ◽

Fibroblast Growth ◽

Bladder Smooth Muscle ◽

Type Iii ◽

Collagen Expression

Bladder hypertrophy is a general consequence of bladder outlet obstruction (BOO) and a typical phenomenon observed in clinical urologic diseases such as benign prostatic hyperplasia and neurogenic bladder. It is characterized by smooth muscle hyperplasia, altered extracellular matrix composition, and increased contractile function. Various growth factors are likely involved in hypertrophic pathophysiology, but their functions remain unknown. In this report, the role of basic fibroblast growth factor (bFGF) was investigated using a rat bladder smooth muscle cell (BSMC) culture system and an original animal model, in which bFGF was released from a gelatin hydrogel directly onto rat bladders. bFGF treatment promoted BSMC proliferation both in vitro and in vivo. In vitro, bFGF downregulated the expression of type I collagen, but upregulated type III collagen. ERK1/2, but not p38MAPK, was activated by bFGF, whereas inhibition of ERK1/2 by PD98059 reversed bFGF-induced BSMC proliferation, type I collagen downregulation, and type III collagen upregulation. In the in vivo release model, bFGF upregulated type III collagen and increased the contractile force of treated bladders. In parallel with these findings, hypertrophied rat bladders created by urethral constriction showed increased urothelial bFGF expression, BSMC proliferation, and increased type III collagen expression compared with sham-operated rats. These data suggest that bFGF from the urothelium could act as a paracrine signal that stimulates the proliferation and matrix production of BSMC, thereby contributing to the hypertrophic remodeling of the smooth muscle layer.

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Cyclic Tensile Strain Induces Tenogenic Differentiation of Tendon-Derived Stem Cells in Bioreactor Culture

BioMed Research International ◽

10.1155/2015/790804 ◽

2015 ◽

Vol 2015 ◽

pp. 1-13 ◽

Cited By ~ 12

Author(s):

Yuan Xu ◽

Qiang Wang ◽

Yudong Li ◽

Yibo Gan ◽

Pei Li ◽

...

Keyword(s):

Cell Proliferation ◽

Tensile Strain ◽

Type I Collagen ◽

3D Culture ◽

Receptor Interaction ◽

Type I ◽

Bioreactor Culture ◽

Cyclic Tensile Strain ◽

Tenogenic Differentiation

Different loading regimens of cyclic tensile strain impose different effects on cell proliferation and tenogenic differentiation of TDSCs in three-dimensional (3D) culture in vitro, which has been little reported in previous literatures. In this study we assessed the efficacy of TDSCs in a poly(L-lactide-co-ε-caprolactone)/collagen (P(LLA-CL)/Col) scaffold under mechanical stimulation in the custom-designed 3D tensile bioreactor, which revealed that cyclic tensile strain with different frequencies (0.3 Hz, 0.5 Hz, and 1.0 Hz) and amplitudes (2%, 4%, and 8%) had no influence on TDSC viability, while it had different effects on the proliferation and the expression of type I collagen, tenascin-C, tenomodulin, and scleraxis of TDSCs, which was most obvious at 0.5 Hz frequency with the same amplitude and at 4% amplitude with the same frequency. Moreover, signaling pathway from microarray analysis revealed that reduced extracellular matrix (ECM) receptor interaction signaling initiated the tendon genius switch. Cyclic tensile strain highly upregulated genes encoding regulators of NPM1 and COPS5 transcriptional activities as well as MYC related transcriptional factors, which contributed to cell proliferation and differentiation. In particular, the transcriptome analysis provided certain new insights on the molecular and signaling networks for TDSCs loaded in these conditions.

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In Vitro Analysis of the Co-Assembly of Type-I and Type-III Collagen

Cellular and Molecular Bioengineering ◽

10.1007/s12195-016-0466-3 ◽

2016 ◽

Vol 10 (1) ◽

pp. 41-53 ◽

Cited By ~ 3

Author(s):

Esma Eryilmaz ◽

Winfried Teizer ◽

Wonmuk Hwang

Keyword(s):

Type Iii Collagen ◽

Type I ◽

Type Iii ◽

Vitro Analysis ◽

In Vitro Analysis

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Corticosterone impairs the mRNA expression and activity of 3β- and 17β-hydroxysteroid dehydrogenases in adult rat Leydig cells

Biochemistry and Cell Biology ◽

10.1139/o06-074 ◽

2006 ◽

Vol 84 (5) ◽

pp. 745-754 ◽

Cited By ~ 21

Author(s):

R. Badrinarayanan ◽

S. Rengarajan ◽

P. Nithya ◽

K. Balasubramanian

Keyword(s):

Mrna Expression ◽

Leydig Cells ◽

Molecular Mechanisms ◽

Experimental Studies ◽

In Vitro Studies ◽

Type I ◽

Total Rna ◽

Type Iii ◽

Hydroxysteroid Dehydrogenases

Clinical and experimental studies, including our own observations, have shown the adverse effects of excess glucocorticoids on testicular steroid hormone production. The present study was designed to gain insight into the molecular mechanisms by which excess corticosterone impairs Leydig cell steroidogenesis. To achieve this, adult rats were administered with corticosterone-21-acetate (2 mg/100 g body weight) twice daily for 15 days. After the treatment period, rats were killed by decapitation. The testes were removed, decapsulated aseptically and used for the isolation of Leydig cells. Purified Leydig cells were used for assessing the activity of 3β- and 17β-hydroxysteroid dehydrogenases (HSDs) and total RNA isolation. For in vitro studies, purified Leydig cells (7.5 × 106 cells) of control rats were plated in culture flasks and exposed to different concentrations (50, 100, 200, 400, and 800 nmol/L) of corticosterone for 24 h. At the end of incubation, total RNA was isolated from cultured Leydig cells, and the mRNA of 3β- and 17β-HSDs was quantified by RT–PCR. A significant reduction in the activities and levels of 3β-HSD type-I and 17β-HSD type-III mRNAs in Leydig cells were observed. In vitro studies demonstrated a dose-dependent significant impairment in both the activity and mRNA expression of these enzymes. These results suggest that corticosterone might have a direct effect on the transcription of the genes of 3β- and 17β-HSD. It is inferred from the present in vivo and in vitro studies that one of the molecular mechanisms by which excess corticosterone decreases the steroidogenic potency of Leydig cells is by suppressing the mRNA expression of 3β-HSD type-I and 17β-HSD type-III enzymes.

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