1. Identification of an immunodominant B-cell epitope in bovine type II collagen and the production of antibodies to type II collagen by immunization with a synthetic peptide representing this epitope
K Morgan, S L Turner, I Reynolds, A H Hajeer, A Brass, J Worthington Immunology. 1992 Dec;77(4):609-16.
Using epitope scanning of 272 short, synthetic peptides representing the amino acid sequence of the CB-11 peptide of type II collagen, we have shown that five strains of rat, immunized with type II collagen, produce antibodies to a region 37-45 amino acids from the amino end of CB-11 peptide. Antibodies to this region always gave the highest binding values suggesting that it is an immunodominant region. Wistar rats immunized with a synthetic peptide representing this region, coupled to keyhole limpet haemocyanin, produced antibodies to this peptide which could still be detected at 1:4000 to 1:8000 dilution but none developed clinical arthritis. All sera also showed binding of antibodies to denatured bovine type II collagen but not to native type II collagen, keyhole limpet haemocyanin or to bovine serum albumin by ELISA. Sera from peptide-immunized rats were examined for antibody binding to the 272 short peptides of the CB-11 peptide and to the synthetic peptides representing shortened forms of the immunodominant region and forms of it with substituted amino acids. These results showed that the antibodies in the peptide-immunized rats were not identical to those produced to that peptide by rats immunized with type II collagen but may represent subpopulations of them. These findings suggest caution in interpreting the role of antibodies to individual peptides in arthritis induction without knowledge of their fine specificity.
2. Food-Derived Collagen Peptides, Prolyl-Hydroxyproline (Pro-Hyp), and Hydroxyprolyl-Glycine (Hyp-Gly) Enhance Growth of Primary Cultured Mouse Skin Fibroblast Using Fetal Bovine Serum Free from Hydroxyprolyl Peptide
Tomoko T Asai, Fumi Oikawa, Kazunobu Yoshikawa, Naoki Inoue, Kenji Sato Int J Mol Sci. 2019 Dec 28;21(1):229. doi: 10.3390/ijms21010229.
Prolyl-hydroxyproline (Pro-Hyp) and hydroxyprolyl-glycine (Hyp-Gly) appear in human blood after ingestion of collagen hydrolysate and trigger growth of fibroblasts attached on collagen gel, which has been associated with beneficial effects upon ingestion of collagen hydrolysate, such as improvement of skin and joint conditions. In the present study, inconsistent results were obtained by using different lots of fetal bovine serum (FBS). Fibroblasts proliferated in collagen gel without adding Pro-Hyp and Hyp-Gly and did not respond to addition of Pro-Hyp and Hyp-Gly, which raises doubts about conclusions from prior research. Unexpectedly high levels of hydroxyprolyl peptides, including Pro-Hyp, however, were present in the FBS (approximately 100 µM), and also in other commercially available forms of FBS (70-80 µM). After removal of low molecular weight (LMW, < 6000 Da) compounds from the FBS by size exclusion chromatography, Pro-Hyp and Hyp-Gly again triggered growth of fibroblasts attached on collagen and increased the number of fibroblasts migrated from mouse skin. These results indicate the presence of bioactive hydroxyprolyl peptides in commercially available FBS, which can mask effects of Pro-Hyp and Hyp-Gly supplementation; our work confirms that Pro-Hyp and Hyp-Gly do play crucial roles in proliferation of fibroblasts.
3. A double-blind, placebo-controlled, randomised, clinical study on the effectiveness of collagen peptide on osteoarthritis
Suresh Kumar, Fumihito Sugihara, Keiji Suzuki, Naoki Inoue, Sriraam Venkateswarathirukumara J Sci Food Agric. 2015 Mar 15;95(4):702-7. doi: 10.1002/jsfa.6752. Epub 2014 Jun 24.
Background: Recent studies show that enzymatically hydrolysed collagen, the collagen peptide, is absorbed and distributed to joint tissues and has analgesic and anti-inflammatory properties. A double-blind, placebo-controlled, randomised trial with collagen peptides isolated from pork skin (PCP) and bovine bone (BCP) sources was carried out to study the effectiveness of orally supplemented collagen peptide to control the progression of osteoarthritis in patients diagnosed with knee osteoarthritis. Improvement in treatment was assessed with reduction in Western Ontario McMaster Universities (WOMAC), visual analogue scale (VAS) and quality of life (QOL) scores from baseline to 13 weeks (Visit 7). Safety and tolerability were also evaluated. Results: There was significant reduction from baseline to Visit 7 in the primary end points of WOMAC and VAS scores and in the secondary end point of QOL score in subjects with PCP and BCP groups, while in subjects with placebo group the end point indices remained unaltered. Furthermore, all the score levels of WOMAC, VAS and QOL decreased significantly (P < 0.01) in the study group compared to placebo group in Visit 7. Conclusion: The study demonstrated that collagen peptides are potential therapeutic agents as nutritional supplements for the management of osteoarthritis and maintenance of joint health.
