Collagen Fibers In Connective Tissue Research Articles

Skin Improvement with Antioxidant Effect of Yuja (Citrus junos) Peel Fractions: Wrinkles, Moisturizing, and Whitening.

Yuja (Citrus junos) has been cultivated and used for food and medicinal purposes in China and Korea. Its antioxidant, anti-wrinkle, moisturizing, and whitening effects were evaluated in HaCaT, HDF, and B16F10 cells. UVB has been known to cause cellular stress and the production of reactive oxygen species (ROS). Ambivalence of oxidative stress has been reported; however, excessive levels of ROS contribute to skin aging through the loss of elasticity and collagen fibers of connective tissue in the dermis. Skin aging is one of the biological processes that is affected by various factors, including UVB. Pro-Collagen I and hyaluronic acid contents were measured in UVB-irradiated HaCaT and HDF cells to evaluate the anti-wrinkle and moisturizing effects of Yuja-peel (YJP) fractions in -EA (ethyl acetate), -Hex (hexane), and -BuOH (butanol). The expression of matrix metalloproteinases (MMPs) involved in collagen degradation was confirmed to be inhibited by YJP fractions at both the protein and mRNA levels. Filaggrin and serine palmitoyltransferase (SPT), which are moisturizing factors, were induced by YJP fractions. B16F10 cells were treated with α-MSH to induce hyperpigmentation, and then the whitening efficacy of YJP fractions was verified by observing a decrease in melanin content. Overall, our results contribute to the development of various novel skin-improving cosmetics and pharmaceuticals with YJP fractions as active ingredients.

A Comparative Study of the Effect of Melatonin Versus Vitamin C on Aged Labial Tissues in Albino Rats

Background: Structural changes occur with aging, associated with fibrosis and inflammation in body tissues. Aging of oral mucosa causes alterations in oral epithelium and sub-epithelial tissues, due to reduction in certain growth factors, endogenous anti-oxidant enzymes, or both. Aim: to assess anti-aging potential of melatonin & vitamin C on albino rats’ lips.Materials and Methods: 28 male albino rats were used, divided into: Group I: 7 rats aged 6 months (18 years in humans), Group II: 21 rats aged 24 months (72 years in humans), were equally subdivided into 3 subgroups 7 rats each as follows: Subgroup IIA: positive control for other subgroups; Subgroup IIB: received melatonin via gastric gavage (10mg/kg/day) for six consecutive weeks; Subgroup IIC: received vitamin C via gastric gavage (2mg/ml/day) for six consecutive weeks. At the end of the experiment, rats were sacrificed by a high dose of anesthesia. The lips were excised. Specimens were processed for histological examination, stained by H&E, Masson’s Trichrome& Anti-VEGF, examined by light microscope.Results: Subgroup IIA showed statistically significant increase in number of vacuolated epithelial cells, statistically significant reduction in VEGF positive cells, apparent decrease in epithelial thickness, statistically significant reduction in immature collagen fibers’ percentage within connective tissue (CT). Subgroups IIB & IIC, showed significant reduction in number of vacuolated epithelial cells and significant increase in VEGF positive cells and area percentage of immature collagen fibers in CT. However, subgroup IIB’s epithelial structure showed better image and subgroup IIC’s CT structure presented better image.Conclusion: Aging showed structural changes in skin & mucous membrane sides of rat lips, observed within both epithelium and CT. Melatonin & vit. C exhibited efficiency in counteracting these effects. Melatonin presented superior effect on keratinocytes, vit. C showed superiority in repairing senile CT components.

Reconstitution of the Ventricular Endocardium Within Acellular Hearts

There is a need for developing a living tissue-engineered whole heart for transplantation. One solution is to create acellular myocardial tissue scaffolds and seed them with autologous cells for full reconstitution. Our goal was to reconstitute the endocardial layer of both ventricular cavities and the septum surfaces of decellularized hearts. Whole rabbit hearts were decellularized using a biventricular perfusion system. We designed a rotational support system for the scaffolds and seeded the two cardiac cavities with human fibroblasts, collagen hydrogels, fibrin hydrogel, and human endothelial cells in a layer-by-layer fashion. Afterwards, the scaffold was subjected to in vitro conditioning in a purpose-designed bioreactor. Results showed that hydrogels infused onto most surfaces and pores of the scaffold. Seeded cells effectively adhered to many areas of the two ventricles while remaining active by secreting new matrix proteins. These results indicate that layer-by-layer deposition can aid in the reconstitution of the cardiac endocardium. There is a need for developing a living whole heart for transplantation. In this study, we developed a perfusion system to remove all cells from rabbit hearts, while leaving the connective tissue collagen fibers intact. We then developed a rotational bioreactor system to seed the hearts with human cells in a layer-by-layer fashion by suspending human fibroblasts and endothelial cells in fibrin and collagen gels as carriers. Using these systems, we successfully reconstituted an important internal layer of the heart, the endocardium, lining the cavities of the heart, with most cells remaining alive and active.

Establishment of perpendicular protrusion of type I collagen on TiO2 nanotube surface as a priming site of peri-implant connective fibers

Natural teeth are supported by connective tissue collagen fibers that insert perpendicularly in the tooth cementum. Perpendicular insertion plays an important role in the maintenance of the junction between the oral epithelium and the periodontal connective tissue. Most titanium dental implant surfaces have no micro or macro structure to support perpendicularly oriented collagen attachment. Without this tight biologic seal to resist bacterial invasion and epithelial downgrowth, progressive bone loss in peri-implantitis is seen around dental implants. The purpose of this study was to establish the perpendicularly oriented collagen attachment to titanium oxide nanotube (TNT), and to assess its binding stability. TNT was prepared on the titanium-surface by anodization. Scanning electron microscopy (SEM) showed a regularly aligned TNT with an average 67 nm-diameter when anodized at 30 V for 3 h. Subsequently, collagen type I (CoI) was electrophoretically fused to anodic TNT in native polyacrylamide gel system where negatively charged CoI-C term was perpendicularly navigated to TNT. SEM and atomic force microscopy (AFM) were used to analyze CoI on the TiO2 and TNT surface. Several tens of nanometers of CoI protrusion were recorded by AFM. These protrusions may be long enough to be priming sites for cell-secreted CoI. CoI laid parallel to the titanium surface when fused by a chemical linker. Binding resistance of CoI against drastic ultrasonication was measured by Fourier-transform infrared spectroscopy attenuated total reflection (FTIR-ATR). The electrophoretically fused CoI in the titanium nanotube (TNT–CoIEPF) showed the significantly greatest binding resistance than the other groups (P < 0.01, a 1-way ANOVA and Tukey HSD post hoc test). Furthermore, TNT–CoIEPF surface rejected epithelial cell stretching and epithelial sheet formation. Chemically linked horizontal CoI on titanium oxide (TiO2) facilitated epithelial cell stretching and sheet formation.

Short-term use of resveratrol in alloplastic graft material applied with calvarial bone defects in rats

Purpose:The effects of resveratrol administration on calvarial bone defects with alloplastic graft material was investigated for osteoinductive reaction and bone development in rats.Methods:Healthy male rats were randomly divided into 3 groups consisting of 10 rats. Groups were as follows: control (defect) group, defect + graft group, and defect + graft + resveratrol group. A calvarial bone defect was created in all groups, alloplastic bone grafts were applied to the defect in the 2nd and 3rd group, resveratrol (5 mg/kg/day) was added to the drinking water of the animals following graft application for 28 days in the 3rd group.Results:Increase in osteoclasts and necrotic changes were observed histopathologically in the control group. In the 2nd group, reduction of inflammation, congestion of blood vessels, increased osteblastic activity, osteoinductive effect, progression of osteocyte development and increased collagen fibers in connective tissue were observed. In the 3rd group, osteoblasts seemed to secrete bone matrix and accelerate osteoinductive effect with increased osteopregenitor activity and positive osteopontin and osteonectin expressions.Conclusion:Resveratrol treatment was thought to be an alternative and supportive drug for implant application by inducing new bone formation in the calvaral defect region as a result of short-term treatment.

A case report of ear pinna fibrosarcoma in a non-descript goat

A 5 years old non-descript female goat was presented to Teaching Veterinary Clinical Complex, Veterinary College and Research Institute, Namakkal for treatment with the history of progressive growth at the base of the left ear pinna. Grossly, the mass was large, circular and firm in consistency. The whole left ear pinna along with entire mass was removed surgically. Tissue pieces from multiple areas of the mass were collected in 10% formalin and processed for histopathological examination. Microscopically, the mass consisted of interwoven bundles of immature fibroblasts and intermixed with elongated muscle fibers. The histomorphology pattern of the tumour was studied by Van Gieson stain to differentiate muscle cell with connective tissue collagen fibers. The cells were fusiform to ovoid shape with hyperchromatic and elongated/plump nuclei. Based on histopathological picture and special staining, the case was confirmed as fi brosarcoma. This case report describes the successful surgical removal of fibrosarcoma on ear pinna in a non-descriptive female goat.

Enamel Matrix Derivative Promotes Healing of a Surgical Wound in the Rat Oral Mucosa.

Enamel matrix proteins (EMPs) play a role in enamel formation and the development of the periodontium. Sporadic clinical observations of periodontal regeneration treatments with enamel matrix derivative (EMD), a commercial formulation of EMPs, suggest that it also promotes post-surgical healing of soft tissues. In vitro studies showed that EMD stimulates various cellular effects, which could potentially enhance wound healing. This study examines the in vivo effects of EMD on healing of an oral mucosa surgical wound in rats. A bilateral oral mucosa wound was created via a crestal incision in the anterior edentulous maxilla of Sprague-Dawley rats. Full-thickness flaps were raised, and, after suturing, EMD was injected underneath the soft tissues on one side, whereas the EMD vehicle was injected in the contralateral side. Animals were sacrificed after 5 or 9 days, and the wound area was subjected to histologic and immunohistochemical analysis of the epithelial gap, number of macrophages, blood vessels, proliferating cells, and collagen content in the connective tissue (CT). Gene expression analysis was also conducted 2 days post-surgery. EMD had no effect on the epithelial gap of the wound. On both days 5 and 9, EMD treatment increased significantly the number of blood vessels and the collagen content. EMD also enhanced (by 20% to 40%) the expression of transforming growth factors β1 and β2, vascular endothelial growth factor, interleukin-1β, matrix metalloproteinase-1, versican, and fibronectin. EMD improves oral mucosa incisional wound healing by promoting formation of blood vessels and collagen fibers in CT.

Polarized Light Microscopic Analysis of Bone Formation After Inhibition of Cyclooxygenase 1 and 2

Potassium diclofenac is a potent nonsteroidal anti-inflammatory drug (NSAID) and COX isoforms (COX-1 and COX-2) inhibitor. Quantitative analysis of birefringence with polarized light microscopy is a useful method to investigate the macromolecular orientation and organization of collagen fibers in connective tissues. The aim of this research was to analyze the collagen structure and maturation in bone formed after potassium diclofenac administration, during first molar orthodontic movement. Sixty Wistar rats were divided in two equal groups (N = 30): control (C) and potassium diclofenac (PD). The animals in Group C received 0.9% saline solution and the PD group received potassium diclofenac Cataflam (5 mg/kg). Animals were sacrificed 3, 7, or 14 days after a NiTi unilateral closed-coil spring was stretched between the upper right first molar and the incisors. The first molar area was fixed, decalcified, and histologically processed using picrosirius pigment. The collagen birefringence of bone turnover was analyzed by phase retardation. Two-way ANOVA and Tukey's test showed that optical retardation was influenced by time and treatment. There was increase in the collagen organization over time. On the third day, the C group showed better collagen organization than the PD group. Potassium diclofenac interfered in collagen maturation, reducing fibril organization in the initial phase of orthodontic movement.

A quantitative method to determine the orientation of collagen fibers in the dermis.

We have developed a quantitative microscopic method to determine changes in the orientation of collagen fibers in the dermis resulting from mechanical stress. The method is based on the use of picrosirius red-stained cryostat sections of piglet skin in which collagen fibers reflect light strongly when epipolarization microscopy is used. Digital images of sections were converted into binary images that were analyzed quantitatively on the basis of the length of the collagen fibers in the plane of the section as a measure for the orientation of the fibers. The length of the fibers was expressed in pixels and the mean length of the 10 longest fibers in the image was taken as the parameter for the orientation of the fibers. To test the procedure in an experimental setting, we used skin after 0 and 30 min of skin stretching. The orientation of the fibers in sections of control skin differed significantly from the orientation of fibers in sections of skin that was stretched mechanically for 30 min [76 +/- 15 (n=5) vs 132 +/- 36 (n=5)]. The method described here is a relatively simple way to determine (changes in) the orientation of individual collagen fibers in connective tissue and can also be applied for analysis of the orientation of any other structural element in tissues so long as a representative binary image can be created.

Effect of glycyrrhetinic acid on the viability of human gingival fibroblasts

Some therapeutic agents and medicines such as phenytoin(PHT), nifedipine and cyclosporine may lead to adverse effects causing pathologic changes in tissue, especially on the gingivae1-8). The common histological finding is a marked gingival hyperplasia, with proliferation of gingival fibroblasts and an increase of collagen fibers in connective tissue. PHT-induced human gingival overgrowth may be genetically programmed for increased synthesis of collagen9). PHT-induced gingival overgrowth was preceded by the inflammation of gingivae10-11). Previous studies reported that PHT, nifedipine and cyclosporine increased the cell activity of human gingival fibroblasts12-17). Some differentiation factors such as glycyrrhetinic acid(GA), retinoic acid, ursolic acid and oleanolic acid inhibited18-25). Previous studies reported that GA inhibited intercellular communication between human fibroblasts26-27). Glycyrrhizin(GL), a major component of licorice (Glycyrrhiza glabra L.), is ingested orally as a sweetener or as an ingredient in oriental medicine. GL has a steroid-like action and anti-viral activity (Pompei et al., 1979). Indeed, use of GL to treat chronic viral hepatitis has shown that it can reduce hepatocellular injury by immunopathologic mechanisms and hepatotoxins, possibly through its ability to inhibit phospholipase A2 activity preventing liver lysosome labilization29-30). GL is metabolized to GA, and then 3-epi-18-GA via 3-keto-18-GA by human intestinal flora31). GA shows pronounced antiinflammatory activity and anti-estrogenic action via alteration of cortisol metabolism32-35). GA inhibits the growth and stimulates melanogenesis in cultured melanoma cells36). There are many reports about the use of differentiation factors for the resolution of uncontrolled growth such as in tumors, but there are few report about its use in the dental field including gingival hyperplasia. The purpose of this study was to investigate the 대한치주과학회지 : Vol. 28, No. 3, 1998

Dependence of stress-strain nonlinearity of connective tissues on the geometry of collagen fibres

Collagen fibers in connective tissues have a periodic, “crimped” shape. In this work, they are modelled as long, sinusoidal beams. Constitutive equations in uniaxial tension are obtained by geometric considerations for a single collagen fiber as well as for bundles of fibers embedded in a matrix. The effect of fiber orientation is briefly discussed.

The intracellular biosynthesis of collagen. Some possible implications for diseases of bone and other connective tissues.

The work performed in this laboratory in the last several years bears only indirectly on the subject of this symposium, but it probably provides a basic framework for biochemical approaches to the problems which occur in bone as a result of long-term dialysis. Collagen is the principal organic constituent of bone, and one of the questions we and others have asked is1: How do cells in connective tissue synthesize collagen? Before discussing this question, however, I will present a brief review of the structure of the collagen molecule as it is known.2-5 Structure of Collagen The collagen fibers in connective tissues are made up of small fibrils which have a characteristic pattern when examined by electron microscopy (Fig 1). The most characteristic feature of these fibrils is a series of major crossbands which are separated by a distance of approximately 700 Angstroms (A). As was demonstrated primarily

The Intracellular Biosynthesis of Collagen

The work performed in this laboratory in the last several years bears only indirectly on the subject of this symposium, but it probably provides a basic framework for biochemical approaches to the problems which occur in bone as a result of long-term dialysis. Collagen is the principal organic constituent of bone, and one of the questions we and others have asked is¹: How do cells in connective tissue synthesize collagen? Before discussing this question, however, I will present a brief review of the structure of the collagen molecule as it is known.^2-5 <h3>Structure of Collagen</h3> The collagen fibers in connective tissues are made up of small fibrils which have a characteristic pattern when examined by electron microscopy (Fig 1). The most characteristic feature of these fibrils is a series of major crossbands which are separated by a distance of approximately 700 Angstroms (A). As was demonstrated primarily

The carbohydrate of basement membranes of human kidney glomeruli

It has been shown by fluorescent antibody technique that rabbit anti-sera against rat kidney glomeruli basement membranes and lens capsule cross-react with each other as well as other basement membranes but not with collagen fibers of connective tissue 1,2. It has been, furthermore, reported that the lens capsules of cattle 3 and rabbit 4 contain chains of glucose and galactose linked to collagen and a sialofucoglycan in a glycoprotein. This suggested that one or both of these glycans may be the common or cross-reacting antigen in the lens capsule and basement membranes. This report brings evidence that the basement membrane of human kidney glomeruli contains both these types of carbohydrate; one consisting of glucose and galactose linked to collagen, and the other a sialofucohexosaminoglycan.