TGF-β1-induced Collagen Promotes Chicken Ovarian Follicle Development via an Intercellular Cooperative Pattern

  • Follicle development is a complex process under strict regulation of diverse hormones and cytokines including transforming growth factor β (TGF-β) superfamily members. TGF-β is pivotal for the regulation of ovarian functions under physiological and pathological conditions. In this study, effect of TGF-β1 on chicken follicle development was examined through investigating the accumulation and action of collagen, an indispensable member of the ECM involved in this process.
  • The granulosa cells (GCs) and theca cells (TCs) were separated from growing follicles of the laying chicken for treatment of TGF-β1 and analysis of expression of ECM components and key proteins in intracellular signaling pathways. Results showed that collagen was mainly distributed in the follicular theca layer and was produced with the formation of the granulosa layer during ovarian development. Collagen accumulation increased with follicle growth and treatment of GCs with TGF-β1 elicited an increased expression of collagen.
  • After production from GCs, collagen was transferred to the neighboring TCs to promote cell proliferation and inhibit apoptosis. Treatment of collagen remarkably increased expression of p-ERK, MAPK and p-MAPK, but treatment with hydroxylase inhibitor (to break collagen structure) reversed these alterations. In conclusion, during follicle growth collagen was secreted by GCs under TGF-β1 stimulation and was subsequently collaboratively transferred to neighboring TCs to increase cell proliferation and thus to promote follicle development via an intercellular cooperative pattern during development of chicken growing follicles. This article is protected by copyright. All rights reserved.

Oral administration of undenatured native chicken type II collagen (UC-II) diminished deterioration of articular cartilage in a rat model of osteoarthritis (OA).

The aim of this study was to determine the ability of undenatured native chicken type II collagen (UC-II) to prevent excessive articular cartilage deterioration in a rat model of osteoarthritis (OA).
Twenty male rats were subjected to partial medial meniscectomy tear (PMMT) surgery to induce OA. Immediately after the surgery 10 rats received vehicle and another 10 rats oral daily dose of UC-II at 0.66 mg/kg for a period of 8 weeks. In addition 10 naïve rats were used as an intact control and another 10 rats received sham surgery. Study endpoints included a weight-bearing capacity of front and hind legs, serum biomarkers of bone and cartilage metabolism, analyses of subchondral and cancellous bone at the tibial epiphysis and metaphysis, and cartilage pathology at the medial tibial plateau using histological methods.
PMMT surgery produced moderate OA at the medial tibial plateau. Specifically, the deterioration of articular cartilage negatively impacted the weight bearing capacity of the operated limb. Immediate treatment with the UC-II preserved the weight-bearing capacity of the injured leg, preserved integrity of the cancellous bone at tibial metaphysis and limited the excessive osteophyte formation and deterioration of articular cartilage.
Study results demonstrate that a clinically relevant daily dose of UC-II when applied immediately after injury can improve the mechanical function of the injured knee and prevent excessive deterioration of articular cartilage.

Estradiol inhibits hepatic stellate cell area and collagen synthesis in the chicken liver.

Hepatic stellate cells (HSCs) are the main collagen-producing cells in the liver. The HSC area and amount of collagen fibers are different between male and female chickens. This study was performed to confirm the effect of estradiol on collagen synthesis in the growing chicken liver. Blood estradiol levels in chicks were compared at 4 and 8 weeks of age, and the collagen fibril network in liver tissue was observed at 8 weeks by scanning electron microscopy. Intraperitoneal administrations of estradiol and tamoxifen to male and female chicks, respectively, were performed daily from 5 to 8 weeks of age.
The areas of HSCs and collagen contents were measured in the liver tissue. The blood estradiol level was higher in females than in males, and the collagen fibril network was denser in males than in females at 8 weeks of age. Estradiol administration in males induced decreases in the HSC area and collagen content of the liver. Conversely, tamoxifen administration in females induced an increase in the HSC area but did not facilitate collagen synthesis. Based on these results, estradiol inhibits the area and collagen synthesis of HSCs in the growing chicken liver under normal physiological conditions.

Native Chicken Collagen Type II

NATE-1165 Creative Enzymes 1kg 453.6 EUR

Chicken Collagen type I alpha 2,COL1A2/Collagen I ELISA Kit

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Chicken Collagen type I alpha 2,COL1A2/Collagen I ELISA Kit

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Chicken Collagen VI(COL6) ELISA Kit

NSL0931Ch Sunlong 1026 T 528 EUR

Chicken Collagen Type IX α1 ELISA

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Chicken Collagen Type I ELISA kit

E01A89328 BlueGene 96T 700 EUR

Chicken Collagen Type Ⅲ ELISA kit

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Chicken Collagen Type IV ELISA kit

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Chicken Collagen Type 5 ELISA kit

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Chicken Collagen Type X ELISA kit

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Chicken Collagen Type II ELISA kit

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Chicken Collagen Type IV ELISA Kit

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Chicken Collagen Type VII ELISA kit

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Chicken Collagen type I alpha 2, COL1A2/Collagen I GENLISA ELISA

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Chicken Collagen Type VIII ELISA kit

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Chicken Collagen Type XVII ELISA kit

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Chicken Collagen autoantibody ELISA Kit

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Chicken Soluble Collagen ELISA kit

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Chicken Collagen Type VI α6 Elisa kit

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Chicken Collagen Type VI (COL6) ELISA Kit

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Effects of PDGF-BB delivery from heparinized collagen sutures on the healing of lacerated chicken flexor tendon in vivo.

  • Flexor tendon lacerations are traditionally repaired by using non-absorbable monofilament sutures. Recent investigations have explored to improve the healing process by growth factor delivery from the sutures. However, it is difficult to conjugate growth factors to nylon or other synthetic sutures. This study explores the performance of a novel electrochemically aligned collagen suture in a flexor tendon repair model with and without platelet derived growth factor following complete tendon laceration in vivo. Collagen suture was fabricated via electrochemical alignment process. Heparin was covalently bound to electrochemically aligned collagen sutures (ELAS) to facilitate affinity bound delivery of platelet-derived growth factor-BB (PDGF-BB).
  • Complete laceration of the flexor digitorum profundus in the third digit of the foot was performed in 36 skeletally mature White Leghorn chickens. The left foot was used as the positive control. Animals were randomly divided into three groups: control specimens treated with standard nylon suture (n=12), specimens repaired with heparinated ELAS suture without PDGF-BB (n=12) and specimens repaired with heparinated ELAS suture with affinity bound PDGF-BB (n=12). Specimens were harvested at either 4weeks or 12weeks following tendon repair. Differences between groups were evaluated by the degree of gross tendon excursion, failure load/stress, stiffness/modulus, absorbed energy at failure, elongation/strain at failure.
  • Quantitative histological scoring was performed to assess cellularity and vascularity. Closed flexion angle measurements demonstrated no significant differences in tendon excursion between the study groups at 4 or 12weeks. Biomechanical testing showed that the group treated with PDGF-BB bound heparinated ELAS suture had significantly higher stiffness and failure load (p<0.05) at 12-weeks relative to both heparinated ELAS suture and nylon suture. Similarly, the group treated with PDGF-BB bound suture had significantly higher ultimate tensile strength and Young’s modulus (p<0.05) at 12-weeks relative to both ELAS suture and nylon suture. Compared to nylon controls, heparinized ELAS with PDGF-BB improved biomechanics and vascularity during tendon healing by 12-weeks following primary repair. The ability of ELAS to deliver PDGF-BB to the lacerated area of tendon presents investigators with a functional bioinductive platform to improve repair outcomes following flexor tendon repair.
  • A high strength aligned collagen suture was fabricated via linear electrocompaction and heparinized for prolonged delivery of PDFG-BB.When it was used to suture a complete lacerated flexor tendon in a chicken model controlled release of the PDGF-BB improved the strength of treated tendon after 12 weeks compared to tendon sutured with commercial nylon suture. Furthermore, Collagen suture with affinity bound PDGF-BB enhanced the vascularization and remodeling of lacerated tendon when it compare to synthetic nylon suture. Overall, electrocompacted collagen sutures holds potential to improve repair outcome in flexor tendon surgeries by improving repair strength and stiffness, vascularity, and remodeling via sustained delivery of the PDGF-BB. The bioinductive collagen suture introduces a platform for sustained delivery of other growth factors for a wide-array of applications.

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