Collagen-derived peptides modulate CD4 T-cell differentiation and suppress allergic responses in mice.

Introduction: Collagen peptides have been widely used as a food supplement. After ingestion of collagen peptides, oligopeptides containing hydroxyproline (Hyp), which are known to have some physiological activities, are detected in peripheral blood. However, the effects of collagen-peptide administration on immune response are unclear.

Collagen peptide ingestion alters lipid metabolism-related gene expression and the unfolded protein response in mouse liver.

Ingestion of collagen peptide (CP) elicits beneficial effects on the body, including improvement in blood lipid profiles, but the underlying mechanisms remain unclear. The purpose of this study was to investigate the effects of CP ingestion on the liver, which controls lipid metabolism in the body. Male BALB/cCrSlc mice were bred with the AIN-93M diet containing 14 % casein or the AIN-93M-based low-protein diet containing 10 % casein or a diet containing 6 % casein+4 % CP for 10 weeks (n 12/group).

Ring-Mesh Model of Proteoglycan Glycosaminoglycan Chains in Tendon based on Three-dimensional Reconstruction by Focused Ion Beam Scanning Electron Microscopy.

Tendons are composed of collagen fibrils and proteoglycan predominantly consisting of decorin. Decorin is located on the d-band of collagen fibrils, and its glycosaminoglycan (GAG) chains have been observed between collagen fibrils with transmission electron microscopy. GAG chains have been proposed to interact with each other or with collagen fibrils, but its three-dimensional organization remains unclear.

A Rapid and Simple LC-MS Method Using Collagen Marker Peptides for Identification of the Animal Source of Leather.

Identification of the animal source of leather is difficult using traditional methods, including microscopic observation and PCR. In the present study, a LC-MS method was developed for detecting interspecies differences in the amino acid sequence of type I collagen, which is a major component of leather, among six animals (cattle, horse, pig, sheep, goat, and deer). After a dechroming procedure and trypsin digestion, six tryptic peptides of type I collagen were monitored by LC-MS in multiple reaction monitoring mode for the animal source identification using the patterns of the presence or absence of the marker peptides.

Oral ingestion of collagen peptide causes change in width of the perimysium of the chicken iliotibialis lateralis muscle.

Skeletal muscle is mainly composed of myofibers and intramuscular connective tissue. Bundles composed of many myofibers, with each myofiber sheathed in connective tissue called the endomysium, are packed in the perimysium, which occupies the vast bulk of the intramuscular connective tissue. The perimysium is a major determination factor for muscle texture.

Comparative study of dermal components and plasma TGF-β1 levels in Slc39a13/Zip13-KO mice.

Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities that are identified in the extracellular matrix. Transforming growth factor-β1 (TGF-β1) plays a crucial role in formation of the extracellular matrix. It has been reported that the loss of function of zinc transporter ZRT/IRT-like protein 13 (ZIP13) causes the spondylocheiro dysplastic form of EDS (SCD-EDS: OMIM 612350), in which dysregulation of the TGF-β1 signaling pathway is observed, although the relationship between the dermis abnormalities and peripheral TGF-β1 level has been unclear.

Detection of endogenous and food-derived collagen dipeptide prolylhydroxyproline (Pro-Hyp) in allergic contact dermatitis-affected mouse ear.

Generation of collagen dipeptides and deposition of orally administered prolylhydroxyproline (Pro-Hyp) in local inflammatory sites were examined in mice with hapten (2,4-dinitrofluorobenzene)-induced dermatitis in the ear. Pro-Hyp content in the hapten-treated ear was significantly higher in the chronic phase of contact dermatitis than the vehicle control. In contrast, hydroxyprolylglycine contents remained at lower levels in all cases compared to Pro-Hyp.

Collagen peptide and vitamin C additively attenuate age-related skin atrophy in Sod1-deficient mice.

Age-related skin thinning is correlated with a decrease in the content of collagen in the skin. Accumulating evidence suggests that collagen peptide (CP) and vitamin C (VC) transcriptionally upregulate type I collagen in vivo. However, the additive effects of CP and VC on age-related skin changes remain unclear.

Effects of collagen peptide ingestion on UV-B-induced skin damage.

The effect of daily ingestion of collagen peptide on the skin damage induced by repeated UV-B irradiation was examined. Ingestion of collagen peptide (0.2 g/kg/d) suppressed UV-B-induced decreases in skin hydration, hyperplasia of the epidermis, and decreases in soluble type I collagen.

Weakness in intercellular association of keratinocytes in severely brittle nails.

The brittle fingernail is a common complaint, but the features of the cellular structure of the nail plate remain unclear. In this study, clipped nailplates from two persons with severely brittle nails, one female aged 26 years and one male aged 82 years, were observed by light and electron microscopy and compared with normal nail plates. Numerous cracks were observed in clipped brittle nails, but not in normal nails, on light microscopy.

Effects of ingestion of collagen peptide on collagen fibrils and glycosaminoglycans in the dermis.

In order to investigate the effects of collagen peptide ingestion on fibroblasts and the extracellular matrix in the dermis, collagen peptide was administered orally to pigs at 0.2 g/kg body weight/d for 62 d, and its effects were compared with those of lactalbumin and water controls. Fibroblast density, and diameter and density of collagen fibrils were significantly larger in the collagen peptide group than in the lactalbumin and water control groups.

Effects of ingestion of collagen peptide on collagen fibrils and glycosaminoglycans in Achilles tendon.

In order to investigate whether the oral ingestion of collagen peptide affects the extracellular matrix of tendon, two doses (0.2 g/kg and 1.0 g/kg body weight) were orally administered daily for 56 d to a rabbit, and both the size of collagen fibrils and the amount of glycosaminoglycans in the Achilles tendon were measured in comparison with those in a rabbit fed with a control protein, lactalbumin, or water alone.

Cloning and nucleotide sequence of a novel 28-kDa protein from the mantle muscle of the squid Todarodes pacificus with homology to tropomyosin.

In recent studies, we found autodegradation of collagen from the mantle muscle of the squid Todarodes pacificus and also that the 28- and 25-kDa proteins are closely related to this phenomenon [Connect. Tissue Res. 45 (2004) 109-121].

Collagen of chronically inflamed skin is over-modified and upregulates secretion of matrix metalloproteinase 2 and matrix-degrading enzymes by endothelial cells and fibroblasts.

In order to investigate the properties of collagen in chronically inflamed tissue, we isolated collagen from the ear skin of mice with chronic contact dermatitis and examined its biochemical characteristics and the functions that regulate the secretion of matrix metalloproteinase 2 and collagen-degrading enzymes from endothelial cells and fibroblasts. Collagen in skin with chronic contact dermatitis comprised 60% type I collagen and 40% type III collagen, which latter is higher than the content of type III collagen in control skin (35%). The denaturation temperature was higher (42 degrees C) than that of control skin (39 degrees C).

Size control of decorin dermatan sulfate during remodeling of collagen fibrils in healing skin.

Recently it has been reported that the molecular size of decorin dermatan sulfate (DS) was increased in healing skin after hapten application and that the elongated DS was distributed in enlarged interfibrillar space among thin collagen fibrils in situ. Here we show that such modulation of the length of decorin DS is temporary. Although the size of decorin DS was evidently increased on day 15, it decreased to almost normal size on day 35 when the altered disaccharide composition of DS was also recovered.

Expression of cellular prion-related protein by murine Langerhans cells and keratinocytes.

Transmissible spongiform encephalopathies are characterized by the accumulation of a proteinase-resistant isoform of the cellular prion-related protein (PrP(c)) within the central nervous system (CNS). The accumulation of scrapie-associated PrP (PrP(Sc)) within cells of the lymphoreticular system prior to its accumulation in the CNS is regarded as important for the development of neurological diseases after peripheral inoculation. Little, however, is known as to which cells are the targets for peripheral inoculation.