Collagen metabolism of human osteoarthritic articular cartilage as modulated by bovine collagen hydrolysates

Collagen Hydrolysates as Nutritional Support in Canine Osteoarthritis: A Narrative Review

Osteoarthritis (OA) is a common disease in dogs with severe impact on their welfare. The multimodal management of OA includes feeding therapeutic diets and nutraceuticals to slow down OA progression. Collagen hydrolysates (CH) are a nutritional supplement that may exert anabolic effects on osteoarthritic joint cartilage as well as disease-modifying effects. After oral intake, CH is absorbed, mainly as amino acids, di- and tripeptides that are transported amongst others to the joint. In addition to reducing cartilage degradation, CH metabolites may reduce synovial inflammation and subchondral bone sclerosis during OA. Preliminary evidence in dogs suffering from the consequences of OA support the clinical efficacy of CH with reported reductions in lameness. However, effects on biomarker level of cartilage metabolism and inflammation are inconclusive. Additionally, current studies show a lack of standardised dosing regimens and the use of not validated outcomes. Future work should therefore elucidate further on the bioavailability of CH in dogs in order to establish adequate dosing recommendations. Furthermore, high-quality placebo-controlled randomised controlled trials are essential to dstudies have evaluated the cetermine the clinical efficacy of CH to reduce lameness, prevent OA progression and thereby improve the level of evidence.

Impact of Specific Bioactive Collagen Peptides on Joint Discomforts in the Lower Extremity during Daily Activities: A Randomized Controlled Trial

The intake of specific collagen peptides (SCPs) has been shown to decrease activity-related knee pain in young, physically active adults. This trial investigated the effect of a 12-week SCP supplementation in a wider age range of healthy men and women over 18 years with functional knee and hip pain during daily activities. A total of 182 participants were randomly assigned to receive either 5 g of specific collagen peptides (CP-G) or a placebo (P-G). Pain at rest and during various daily activities were assessed at baseline and after 12 weeks by a physician and participants using a 10-point numeric rating scale (NRS). The intake of 5 g SCP over 12 weeks significantly reduced pain at rest (p = 0.018) and during walking (p = 0.032) according to the physician's evaluation. Participants in the CP-G also reported significantly less pain when climbing stairs (p = 0.040) and when kneeling down (p < 0.001) compared to the P-G. Additionally, after 12 weeks, restrictions when squatting were significantly lower in the CP-G compared with the P-G (p = 0.014). The daily intake of 5 g of SCP seems to benefit healthy adults with hip and knee joint discomforts by reducing pain during daily activities.

Analysis of Chemical Constituents of Miao Ethnomedicine Heiguteng Zhuifeng Huoluo Capsule (HZFC) and the Discovery of Active Substances in the Treatment of Rheumatoid Arthritis

In this study, the chemical substances of Heiguteng Zhuifeng Huoluo Capsule (HZFC) and its potential active ingredients for the treatment of rheumatoid arthritis (RA) were characterized and analyzed by medicinal chemistry combined with bioinformatics methods. Also, the potential active ingredients of HZFC against RA were verified by lipopolysaccharide (LPS)-induced macrophage activation model. The results showed that 79 chemical constituents were successfully identified, mainly including phenylpropanoids, flavonoids, and alkaloids. Among them, 13 active components were closely related to the nine core targets (FASN, ALOX5, EGFR, MMP1, CYP2D6, CNR1, AR, MAOA, and FKBP5) of HZFC in the treatment of RA. Molecular docking further proved that 13 active components had strong docking activity with 9 core targets. In the verification experiment of the LPS-induced RAW 264.7 macrophage model, the verified components (magnoflorine, N-feruloyltyramine, canadine, rutin, quercetin-3-O-glucoside, and pseudocolumbamine) all showed a clear inhibitory effect on the secretion of inflammatory factors in model cells. The above research results suggest that 13 components such as stepharanine, rutin, quercetin-3-O-glucoside, corydine methyl ether, canadine, 8-oxoepiberberine, disinomenine, deosinomenine glucoside, tuduranine, magnoflorine, isosinomenine, pseudocolumbamine, and N-feruloyltyramine may be the main active substances of HZFC in the treatment of RA.

Blood pH Analysis in Combination with Molecular Medical Tools in Relation to COVID-19 Symptoms

The global outbreak of SARS-CoV-2/COVID-19 provided the stage to accumulate an enormous biomedical data set and an opportunity as well as a challenge to test new concepts and strategies to combat the pandemic. New research and molecular medical protocols may be deployed in different scientific fields, e.g., glycobiology, nanopharmacology, or nanomedicine. We correlated clinical biomedical data derived from patients in intensive care units with structural biology and biophysical data from NMR and/or CAMM (computer-aided molecular modeling). Consequently, new diagnostic and therapeutic approaches against SARS-CoV-2 were evaluated. Specifically, we tested the suitability of incretin mimetics with one or two pH-sensitive amino acid residues as potential drugs to prevent or cure long-COVID symptoms. Blood pH values in correlation with temperature alterations in patient bodies were of clinical importance. The effects of biophysical parameters such as temperature and pH value variation in relation to physical-chemical membrane properties (e.g., glycosylation state, affinity of certain amino acid sequences to sialic acids as well as other carbohydrate residues and lipid structures) provided helpful hints in identifying a potential Achilles heel against long COVID. In silico CAMM methods and in vitro NMR experiments (including ³¹P NMR measurements) were applied to analyze the structural behavior of incretin mimetics and SARS-CoV fusion peptides interacting with dodecylphosphocholine (DPC) micelles. These supramolecular complexes were analyzed under physiological conditions by ¹H and ³¹P NMR techniques. We were able to observe characteristic interaction states of incretin mimetics, SARS-CoV fusion peptides and DPC membranes. Novel interaction profiles (indicated, e.g., by ³¹P NMR signal splitting) were detected. Furthermore, we evaluated GM1 gangliosides and sialic acid-coated silica nanoparticles in complex with DPC micelles in order to create a simple virus host cell membrane model. This is a first step in exploring the structure-function relationship between the SARS-CoV-2 spike protein and incretin mimetics with conserved pH-sensitive histidine residues in their carbohydrate recognition domains as found in galectins. The applied methods were effective in identifying peptide sequences as well as certain carbohydrate moieties with the potential to protect the blood-brain barrier (BBB). These clinically relevant observations on low blood pH values in fatal COVID-19 cases open routes for new therapeutic approaches, especially against long-COVID symptoms.

Efficacy of Chondroprotective Food Supplements Based on Collagen Hydrolysate and Compounds Isolated from Marine Organisms

Osteoarthritis belongs to the most common joint diseases in humans and animals and shows increased incidence in older patients. The bioactivities of collagen hydrolysates, sulfated glucosamine and a special fatty acid enriched dog-food were tested in a dog patient study of 52 dogs as potential therapeutic treatment options in early osteoarthritis. Biophysical, biochemical, cell biological and molecular modeling methods support that these well-defined substances may act as effective nutraceuticals. Importantly, the applied collagen hydrolysates as well as sulfated glucosamine residues from marine organisms were strongly supported by both an animal model and molecular modeling of intermolecular interactions. Molecular modeling of predicted interaction dynamics was evaluated for the receptor proteins MMP-3 and ADAMTS-5. These proteins play a prominent role in the maintenance of cartilage health as well as innate and adapted immunity. Nutraceutical data were generated in a veterinary clinical study focusing on mobility and agility. Specifically, key clinical parameter (MMP-3 and TIMP-1) were obtained from blood probes of German shepherd dogs with early osteoarthritis symptoms fed with collagen hydrolysates. Collagen hydrolysate, a chondroprotective food supplement was examined by high resolution NMR experiments. Molecular modeling simulations were used to further characterize the interaction potency of collagen fragments and glucosamines with protein receptor structures. Potential beneficial effects of collagen hydrolysates, sulfated glycans (i.e., sulfated glucosamine from crabs and mussels) and lipids, especially, eicosapentaenoic acid (extracted from fish oil) on biochemical and physiological processes are discussed here in the context of human and veterinary medicine.

Role of Collagen Derivatives in Osteoarthritis and Cartilage Repair: A Systematic Scoping Review With Evidence Mapping

INTRODUCTION

There is currently no disease-modifying drug for osteoarthritis (OA), and some safety concerns have been identified about the leading traditional drugs. Therefore, research efforts have focused on alternatives such as supplementation with collagen derivatives. The objective of this scoping review is to examine the extent, range, and nature of research, and to summarize and disseminate research findings on the effects of collagen derivatives in OA and cartilage repair. The purpose is to identify gaps in the current body of evidence in order to further help progress research in this setting.

METHODS

The databases Medline, Scopus, CENTRAL, TOXLINE, and CDSR were comprehensively searched from inception to search date. After studies selection against eligibility criteria, following recommended methods, data were charted from the retrieved articles and these were subsequently synthesized. Numerical and graphical descriptive statistical methods were used to show trends in publications and geographical distribution of studies.

RESULTS

The systematic literature search identified a total of 10,834 records. Forty-one published studies were ultimately included in the review, 16 of which were preclinical studies and 25 were clinical studies (including four systematic reviews/meta-analyses). Collagen hydrolysate (CH) and undenatured collagen (UC) were the two types of collagen derivatives studied, with a total of 28 individual studies on CH and nine on UC. More than a third of studies originated from Asia, and most of them have been published after 2008. Oral forms of collagen derivatives were mainly studied; three in vivo preclinical studies and three clinical trials investigated intra-articularly injected CH. In most of the clinical trials, treatment durations varied between 3 and 6 months, with the shortest being 1.4 months and the longest 11 months. All in vivo preclinical studies and clinical trials, regardless of their quality, concluded on beneficial effects of collagen derivatives in OA and cartilage repair, whether used as nutritional supplement or delivered intra-articularly, and whatever the manufacturers of the products, the doses and the outcomes considered in each study.

CONCLUSIONS

Although current evidence shows some potential for the use of CH and UC as an option for management of patients with OA, there is still room for progress in terms of laboratory and clinical research before any definitive conclusion can be made. Harmonization of outcomes in preclinical studies and longer randomized placebo-controlled trials in larger populations with the use of recommended and validated endpoints are warranted before collagen derivatives can be recommended by large scientific societies.

Effectiveness of collagen supplementation on pain scores in healthy individuals with self-reported knee pain: a randomized controlled trial

The purpose of this study was to examine the effects of 12 weeks collagen peptide (CP) supplementation on knee pain and function in individuals with self-reported knee pain. Healthy physically active individuals (n = 167; aged 63 [interquartile range = 56-68] years) with self-reported knee pain received 10 g/day of CP or placebo for 12 weeks. Knee pain and function were measured with the Visual Analog Scale (VAS), the Lysholm questionnaire, and the Knee injury and Osteoarthritis Outcome Score (KOOS). Furthermore, we assessed changes in inflammatory, cartilage, and bone (bio)markers. Measurements were conducted at baseline and after 12 weeks of supplementation. Baseline VAS did not differ between CP and placebo (4.7 [2.5-6.1] vs. 4.7 [2.8-6.2], p = 0.50), whereas a similar decrease in VAS was observed after supplementation (-1.6 ± 2.4 vs. -1.9 ± 2.6, p = 0.42). The KOOS and Lysholm scores increased after supplementation in both groups (p values < 0.001), whereas the increase in the KOOS and Lysholm scores did not differ between groups (p = 0.28 and p = 0.76, respectively). Furthermore, CP did not impact inflammatory, cartilage, and bone (bio)markers (p values > 0.05). A reduced knee pain and improved knee function were observed following supplementation, but changes were similar between groups. This suggests that CP supplementation over a 12-week period does not reduce knee pain in healthy, active, middle-aged to elderly individuals. Novelty CP supplementation over a 12-week period does not reduce knee pain in healthy, active, middle-aged to elderly individuals. CP supplementation over a 12-week period does not impact on inflammatory, cartilage, and bone (bio)markers in healthy, active, middle-aged to elderly individuals.

Undenatured Type II Collagen (UC-II) in Joint Health and Disease: A Review on the Current Knowledge of Companion Animals

OA is quite common in companion animals, especially in large breed dogs and horses. Collagen, the most abundant protein of mammals, has specific connective tissue types for skin, bones, reticulate, basal lamina, bones, cell surfaces, while type II collagen (UC-II) forms the main structure of cartilage tissue. Even at the smaller dosages, UC-II has also been reported to be more effective than the glucosamine and chondroitin sulfate supplements, which are the supplements most frequently used in the market. In this review, we summarize the effects of UC-II on joint health and function in health and disease conditions in companion animals.

The Sialic Acid-Dependent Nematocyst Discharge Process in Relation to Its Physical-Chemical Properties Is A Role Model for Nanomedical Diagnostic and Therapeutic Tools

Formulas derived from theoretical physics provide important insights about the nematocyst discharge process of Cnidaria (Hydra, jellyfishes, box-jellyfishes and sea-anemones). Our model description of the fastest process in living nature raises and answers questions related to the material properties of the cell- and tubule-walls of nematocysts including their polysialic acid (polySia) dependent target function. Since a number of tumor-cells, especially brain-tumor cells such as neuroblastoma tissues carry the polysaccharide chain polySia in similar concentration as fish eggs or fish skin, it makes sense to use these findings for new diagnostic and therapeutic approaches in the field of nanomedicine. Therefore, the nematocyst discharge process can be considered as a bionic blue-print for future nanomedical devices in cancer diagnostics and therapies. This approach is promising because the physical background of this process can be described in a sufficient way with formulas presented here. Additionally, we discuss biophysical and biochemical experiments which will allow us to define proper boundary conditions in order to support our theoretical model approach. PolySia glycans occur in a similar density on malignant tumor cells than on the cell surfaces of Cnidarian predators and preys. The knowledge of the polySia-dependent initiation of the nematocyst discharge process in an intact nematocyte is an essential prerequisite regarding the further development of target-directed nanomedical devices for diagnostic and therapeutic purposes. The theoretical description as well as the computationally and experimentally derived results about the biophysical and biochemical parameters can contribute to a proper design of anti-tumor drug ejecting vessels which use a stylet-tubule system. Especially, the role of nematogalectins is of interest because these bridging proteins contribute as well as special collagen fibers to the elastic band properties. The basic concepts of the nematocyst discharge process inside the tubule cell walls of nematocysts were studied in jellyfishes and in Hydra which are ideal model organisms. Hydra has already been chosen by Alan Turing in order to figure out how the chemical basis of morphogenesis can be described in a fundamental way. This encouraged us to discuss the action of nematocysts in relation to morphological aspects and material requirements. Using these insights, it is now possible to discuss natural and artificial nematocyst-like vessels with optimized properties for a diagnostic and therapeutic use, e.g., in neurooncology. We show here that crucial physical parameters such as pressure thresholds and elasticity properties during the nematocyst discharge process can be described in a consistent and satisfactory way with an impact on the construction of new nanomedical devices.

Determination of Peptide Profile Consistency and Safety of Collagen Hydrolysates as Quality Attributes

Collagen hydrolysates are dietary supplements used for nutritional and medical purposes. They are complex mixtures of low-molecular-weight peptides obtained from the enzymatic hydrolysis of collagen, which provide intrinsic batch-to-batch heterogeneity. In consequence, the quality of these products, which is related to the reproducibility of their mass distribution pattern, should be addressed. Here, we propose an analytical approach to determine the peptide pattern as a quality attribute of Colagenart®, a product containing collagen hydrolysate. In addition, we evaluated the safety by measuring the viability of two cell lines exposed to the product. The consistency of peptide distribution was determined using Size Exclusion Chromatography (SEC), Mass Spectrometry coupled to a reversed phase UPLC system (MS-RP-UPLC), and Shaped-pulse off-resonance water-presaturation proton nuclear magnetic resonance spectrometry [1 Hwater_presat NMR]. The mass distribution pattern determined by SEC was in a range from 1.35 to 17 kDa, and from 2 to 14 kDa by MS-RP-UPLC. [1 Hwater_presat NMR] showed the detailed spin-systems of the collagen hydrolysates components by global assignment of backbone Hα and NH, as well as side-chain proton resonances. Additionally, short-range intraresidue connectivity pathways of identified spin-regions were obtained by a 2D homonuclear shift correlation Shaped-pulse solvent suppression COSY scheme. Safety analysis of Colagenart® was evaluated in CaCo-2 and HepG2 cells at 2.5 and 25 μg/mL and no negative effects were observed. The results demonstrated batch-to-batch reproducibility, which evinces the utility of this approach to establish the consistency of the quality attributes of collagen hydrolysates. PRACTICAL APPLICATION: We propose state-of-the art analytical methodologies (SEC, MS, and NMR) to evaluate peptide profile and composition of collagen hydrolysates as quality attributes. These methodologies are suitable to be implemented for quality control purposes.

Nanomedical Relevance of the Intermolecular Interaction Dynamics-Examples from Lysozymes and Insulins

Insulin and lysozyme share the common features of being prone to aggregate and having biomedical importance. Encapsulating lysozyme and insulin in micellar nanoparticles probably would prevent aggregation and facilitate oral drug delivery. Despite the vivid structural knowledge of lysozyme and insulin, the environment-dependent oligomerization (dimer, trimer, and multimer) and associated structural dynamics remain elusive. The knowledge of the intra- and intermolecular interaction profiles has cardinal importance for the design of encapsulation protocols. We have employed various biophysical methods such as NMR spectroscopy, X-ray crystallography, Thioflavin T fluorescence, and atomic force microscopy in conjugation with molecular modeling to improve the understanding of interaction dynamics during homo-oligomerization of lysozyme (human and hen egg) and insulin (porcine, human, and glargine). The results obtained depict the atomistic intra- and intermolecular interaction details of the homo-oligomerization and confirm the propensity to form fibrils. Taken together, the data accumulated and knowledge gained will further facilitate nanoparticle design and production with insulin or lysozyme-related protein encapsulation.

Comparative Analysis of Peptide Composition and Bioactivity of Different Collagen Hydrolysate Batches on Human Osteoarthritic Synoviocytes

Collagen hydrolysates (CHs) are heterogeneous mixtures of collagen peptides that are often used as nutraceuticals for osteoarthritis (OA). In this study, we compared the peptide composition and pharmacological effects of three different CH preparations (CH-Alpha^®, Peptan^® B 2000 and Mobiforte^®) as well as their production batches. Our biochemical analysis using MALDI-TOF mass spectrometry and the ICPL™-isotope labelling method revealed marked differences between different CH preparations and even between some production batches of the same preparation. We also investigated the pharmacological effects of these CHs on human fibroblast-like synoviocytes (FLS). No significant effects on cultured FLS could be demonstrated for either production batch of CH-Alpha^®, Peptan^® B 2000, and Mobiforte^® analyzing a small number of pharmacological relevant targets. Thus, our study already shows for the first time that different production batches of the same CH preparation as well as different CH preparations can differ significantly in their peptide composition. In this line, further studies are also needed to verify equal pharmacological efficacy of CH batches on a much broader range of (patho)physiological relevant targets. If OA patients are to be offered a safe and effective nutraceutical a better knowledge about all potential effects as well as ensuring the same active-substance levels are a prerequisite.

The Growth Proliferation, Apoptotic Prevention, and Differentiation Induction of the Gelatin Hydrolysates from Three Sources to Human Fetal Osteoblasts (hFOB 1.19 Cells)

Gelatins from the skin of bovine, porcine, and tilapia were hydrolyzed to three degrees of hydrolysis (DH) by alcalase, neutrase, and papain, respectively. These hydrolysates at 0.02⁻0.1 g/L promoted the growth of human fetal osteoblasts by 101.4⁻135.7%, while higher DH or using papain and tilapia gelatins resulted in higher proliferation. The hydrolysates from porcine and tilapia gelatins at 0.05 g/L prevented induced apoptosis (decreasing total apoptotic proportions from 28.4% or 35.2% to 10.3⁻17.5% or 16.0⁻23.6%), and had differentiation induction (increasing alkaline phosphatase activity by 126.9⁻246.7% in early differentiation stage, or enhancing osteocalcin production by 4.1⁻22.5% in later differentiation stage). These hydrolysates had a similar amino acid profile; however, tilapia gelatin hydrolysates by papain with DH 15.4% mostly displayed higher activity than others. Tilapia gelatin hydrolysate could up-regulate β-catenin, Wnt 3a, Wnt 10b, cyclin D1, and c-Myc expression at mRNA levels by 1.11⁻3.60 folds, but down-regulate GSK 3β expression by 0.98 fold. Of note, β-catenin in total cellular and nuclear protein was up-regulated by 1.14⁻1.16 folds but unchanged in cytoplasmic protein, Wnt 10b, cyclin D1, and c-Myc expression were up-regulated by 1.27⁻1.95 folds, whilst GSK 3β expression was down-regulated by 0.87 fold. Activation of Wnt/β-catenin pathway is suggested to mediate cell proliferation and differentiation.

Effect of Fish Collagen Hydrolysates on Type I Collagen mRNA Levels of Human Dermal Fibroblast Culture

Fish discards and subproducts may represent an important source of raw material, not only for the food industry, but for other different kind of industries, such as the nutraceutical and cosmetic industries. Collagen, which is mainly obtained from animal skins, is an important structural protein in the animal kingdom having many different applications. It is well known that fish skins constitute a significant subproduct in the fishery industry, especially in the case of some species, where fish skins may represent up to 20% of the total body weight of fish. Peptides from collagen hydrolysates have been described to be useful for preventing skin aging and osteoarthritis, however, the mechanism for these biological activities is not well known. Fibroblasts are the main cell types involved in the collagen synthesis, and in the present work, human dermal fibroblasts have been exposed to the treatment of collagen peptides of two different molecular weight ranges. Results show that higher molecular weight collagen peptides produce higher synthesis of collagen type I mRNA and, therefore, it may suggest that prior molecular weight selection may be an important step to maximize the effect of collagen hydrolysates on collagen type I synthesis by dermal fibroblasts.

Current status of top 10 nutraceuticals used for Knee Osteoarthritis in India

Knee Osteoarthritis (OA) is a progressive degenerative joint disease affecting the quality of life of the elderly population. There is considerable evidence that nutraceuticals from natural herbs may play a significant role in inflammation and joint destruction in OA. We review the current status of some of the commonly used nutraceuticals in Indian market - Boswellia, Aflapin, Chondroitin sulphate, Glucosamine sulphate, Collagen peptide, Curcumin, Fish Oil, Ginger, Green tea, and Rosehip extract. We have summarized their mechanism of action, biological effects, toxicities and efficacy in the management of Knee OA. These supplements have been found to be effective in knee OA in various studies. No serious side effects have been reported for any of these supplements. Overall, our study identifies and support the use of these nutraceuticals to provide symptomatic relief to patients with knee OA and justify their use as an adjunct therapy for the management. More good quality trials are needed to provide definitive answers to questions related to their efficacy and safety for OA prevention and treatment.

Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides

The aim of the study was to evaluate the use of specific collagen peptides in reducing pain in athletes with functional knee problems during sport. Athletic subjects (n = 139) with functional knee pain ingested 5 g of bioactive collagen peptides (BCP) or a placebo per day for 12 weeks. The primary outcome of the study was a change in pain intensity during activity, which was evaluated by the participants and the attending physicians using a visual analogue scale (VAS). As secondary endpoints, pain intensity under resting conditions, the range of motion of the knee joint, and the use of additional therapeutic options were assessed. The results revealed a statistically significant improvement in activity-related pain intensity in the verum group compared with placebo. (ΔVASBCP = 19.5 ± 2.4; ΔVASPlacebo = 13.9 ± 2.1; p = 0.046). The results were confirmed by the physician’s assessment. (ΔVASBCP = 16.7 ± 1.8; ΔVASPlacebo = 12.2 ± 1.8; p = 0.021). Pain under resting conditions was also improved, but no significance compared with placebo was detected (ΔVASBCP = 10.2 ± 18.4; ΔVASPlacebo = 7.4 ± 15.2; p = 0.209). Due to the high joint mobility at baseline, no significant changes of this parameter could be detected. The use of additional treatment options was significantly reduced after BCP intake. The study demonstrated that the supplementation of specific collagen peptides in young adults with functional knee problems led to a statistically significant improvement of activity-related joint pain.

Metabolic Response of Human Osteoarthritic Cartilage to Biochemically Characterized Collagen Hydrolysates

The most frequent disease of the locomotor system is osteoarthritis (OA), which, as a chronic joint disease, might benefit more from nutrition than acute illnesses. Collagen hydrolysates (CHs) are peptidic mixtures that are often used as nutraceuticals for OA. Three CHs were characterized biochemically and pharmacologically. Our biophysical (MALDI-TOF-MS, NMR, AFM) and fluorescence assays revealed marked differences between CHs of fish (Peptan^® F 5000, Peptan^® F 2000) and porcine (Mobiforte^®) origin with respect to the total number of peptides and common peptides between them. Using a novel dual radiolabeling procedure, no CH modulated collagen biosynthesis in human knee cartilage explants. Peptan^® F 2000 enhanced the activities of the aggrecanase ADMATS4 and ADMATS5 in vitro without loss of proteoglycan from cartilage explants; the opposite effect was observed with Mobiforte^®. Interleukin (IL)-6, matrix metalloproteinase (MMP)-1, -3 and -13 levels were elevated in explants that were treated with Mobiforte^® and Peptan^® F 5000, but not with Peptan^® F 2000. In conclusion, the heterogeneous peptide composition and disparate pharmacological effects between CHs suggest that the effect of a CH preparation cannot be extrapolated to other formulations. Thus, the declaration of a CH as a safe and effective nutraceutical requires a thorough examination of its pleiotropic effects.

Identification of Targets of a New Nutritional Mixture for Osteoarthritis Management Composed by Curcuminoids Extract, Hydrolyzed Collagen and Green Tea Extract

Objective

We have previously demonstrated that a mixture of curcuminoids extract, hydrolyzed collagen and green tea extract (COT) inhibited inflammatory and catabolic mediator’s synthesis by osteoarthritic human chondrocytes. The objective of this study was to identify new targets of COT using genomic and proteomic approaches.

Design

Cartilage specimens were obtained from 12 patients with knee osteoarthritis. Primary human chondrocytes were cultured in monolayer until confluence and then incubated for 24 or 48 hours in the absence or in the presence of human interleukin(IL)-1β (10^-11M) and with or without COT, each compound at the concentration of 4 μg/ml. Microarray gene expression profiling between control, COT, IL-1β and COT IL-1β conditions was performed. Immunoassays were used to confirm the effect of COT at the protein level.

Results

More than 4000 genes were differentially expressed between conditions. The key regulated pathways were related to inflammation, cartilage metabolism and angiogenesis. The IL-1β stimulated chemokine ligand 6, matrix metalloproteinase-13, bone morphogenetic protein-2 and stanniocalcin1 gene expressions and protein productions were down-regulated by COT. COT significantly decreased stanniocalcin1 production in basal condition. Serpin E1 gene expression and protein production were down-regulated by IL-1β. COT reversed the inhibitory effect of IL-1β. Serpin E1 gene expression was up-regulated by COT in control condition.

Conclusion

The COT mixture has beneficial effect on osteoarthritis physiopathology by regulating the synthesis of key catabolic, inflammatory and angiogenesis factors. These findings give a scientific rationale for the use of these natural ingredients in the management of osteoarthritis.

Molecular Basis of the Receptor Interactions of Polysialic Acid (polySia), polySia Mimetics, and Sulfated Polysaccharides

Polysialic acid (polySia) and polySia glycomimetic molecules support nerve cell regeneration, differentiation, and neuronal plasticity. With a combination of biophysical and biochemical methods, as well as data mining and molecular modeling techniques, it is possible to correlate specific ligand-receptor interactions with biochemical processes and in vivo studies that focus on the potential therapeutic impact of polySia, polySia glycomimetics, and sulfated polysaccharides in neuronal diseases. With this strategy, the receptor interactions of polySia and polySia mimetics can be understood on a submolecular level. As the HNK-1 glycan also enhances neuronal functions, we tested whether similar sulfated oligo- and polysaccharides from seaweed could be suitable, in addition to polySia, for finding potential new routes into patient care focusing on an improved cure for various neuronal diseases. The knowledge obtained here on the structural interplay between polySia or sulfated polysaccharides and their receptors can be exploited to develop new drugs and application routes for the treatment of neurological diseases and dysfunctions.

Low-molecular-weight fractions of Alcalase hydrolyzed egg ovomucin extract exert anti-inflammatory activity in human dermal fibroblasts through the inhibition of tumor necrosis factor-mediated nuclear factor κB pathway

Ovomucin is a mucin-like protein from egg white with a variety of biological functions. We hypothesized that ovomucin-derived peptides might exert anti-inflammatory activity. The specific objectives were to test the anti-inflammatory activities of different ovomucin hydrolysates and its various fractions in human dermal fibroblasts, and to understand the possible molecular mechanisms. Three ovomucin hydrolysates were prepared and desalted; only the desalted Alcalase hydrolysate showed anti-inflammatory activity. Desalting of ovomucin hydrolysate enriched the proportion of low-molecular-weight (MW) peptides. Indeed, ultrafiltration of this hydrolysate displayed comparable anti-inflammatory activity in dermal fibroblasts, indicating the responsible role of low-MW bioactive peptides in exerting the beneficial biological function. The anti-inflammatory activity of low-MW peptides was regulated through the inhibition of tumor necrosis factor-mediated nuclear factor κ-light-chain-enhancer of activated B cells activity. Our study demonstrated that both peptide composition and MW distribution play important roles in anti-inflammatory activity. The low-MW fractions prepared from ovomucin Alcalase hydrolysate may have potential applications for maintenance of dermal health and treatment of skin diseases.

T-2 Toxin Alters the Levels of Collagen II and Its Regulatory Enzymes MMPs/TIMP-1 in a Low-Selenium Rat Model of Kashin-Beck Disease

The objectives of this study are to assess T-2 toxin's involvement in low selenium (Se)-induced Kashin-Beck disease (KBD) in rats and unveil the mechanisms underlying this disease. Two hundred thirty rats were randomly divided into two groups after weaning and fed normal or low-Se diets (n = 115), respectively, for a month. After low-Se model confirmation, rats in each group were subdivided into five: two subgroups (n = 20) were fed their current diets (normal or low-Se diets, respectively) for 30 and 90 days, respectively; two other subgroups (n = 25) received their current diets + low T-2 toxin (100 ng/g BW/day) for 30 and 90 days, respectively; and 25 rats were fed their current diets + high T-2 toxin (200 ng/g BW/day) for 30 days. Articular cartilage samples were extracted for hematoxylin and eosin (H&E) staining and immunohistochemistry. Western blot and reverse transcription-polymerase chain reaction (RT-PCR) were used to assess protein and mRNA levels, respectively, of collagen II, matrix metalloproteinase (MMP-1), MMP -3, MMP-13, and tissue inhibitor of metalloproteinase-1 (TIMP-1). Low Se and T-2 toxin synergistically affected animal fitness. Interestingly, low Se + T-2 toxin groups showed KBD characteristics. MMP-1, -3, and -13 mRNA and protein levels generally increased in low-Se groups, while collagen II and TIMP-1 levels showed a downward trend, compared with normal diet fed animals for the same treatment (P < 0.05). T-2 toxin's effect was dose but not time dependent. Low Se and T-2 toxin synergistically alter the expression levels of collagen II as well as its regulatory enzymes MMP-1, MMP-3, MMP-13, and TIMP-1, inducing cartilage damage. Therefore, T-2 toxin may cause KBD in low-Se conditions.

Transport of Neutral Solute Across Articular Cartilage: The Role of Zonal Diffusivities

Transport of solutes through diffusion is an important metabolic mechanism for the avascular cartilage tissue. Three types of interconnected physical phenomena, namely mechanical, electrical, and chemical, are all involved in the physics of transport in cartilage. In this study, we use a carefully designed experimental-computational setup to separate the effects of mechanical and chemical factors from those of electrical charges. Axial diffusion of a neutral solute (Iodixanol) into cartilage was monitored using calibrated microcomputed tomography (micro-CT) images for up to 48 hr. A biphasic-solute computational model was fitted to the experimental data to determine the diffusion coefficients of cartilage. Cartilage was modeled either using one single diffusion coefficient (single-zone model) or using three diffusion coefficients corresponding to superficial, middle, and deep cartilage zones (multizone model). It was observed that the single-zone model cannot capture the entire concentration-time curve and under-predicts the near-equilibrium concentration values, whereas the multizone model could very well match the experimental data. The diffusion coefficient of the superficial zone was found to be at least one order of magnitude larger than that of the middle zone. Since neutral solutes were used, glycosaminoglycan (GAG) content cannot be the primary reason behind such large differences between the diffusion coefficients of the different cartilage zones. It is therefore concluded that other features of the different cartilage zones such as water content and the organization (orientation) of collagen fibers may be enough to cause large differences in diffusion coefficients through the cartilage thickness.

Curcuminoids extract, hydrolyzed collagen and green tea extract synergically inhibit inflammatory and catabolic mediator's synthesis by normal bovine and osteoarthritic human chondrocytes in monolayer

The main objective of this study was to assess the in vitro effects of curcuminoids extract, hydrolyzed collagen and green tea extract in normal bovine chondrocytes and osteoarthritic human chondrocytes cultured in monolayer. This study also investigated the synergic or additive effects of these compounds. Enzymatically isolated primary bovine or human chondrocytes were cultured in monolayer until confluence and then incubated for 24 hours or 48 hours in the absence or in the presence of interleukin-1β and with or without curcuminoids extract, hydrolyzed collagen or green tea extract, added alone or in combination, at different concentrations. Cell viability was neither affected by these compounds, nor by interleukin 1β. In the absence of interleukin-1β, compounds did not significantly affect bovine chondrocytes metabolism. In human chondrocytes and in the absence of interleukin 1β, curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract significantly inhibited matrix metalloproteinase-3 production. In interleukin-1β-stimulated bovine chondrocytes, interleukin-6, inducible nitric oxide synthase, cyclooxygenase2, matrix metalloproteinase 3, a disintegrin and metalloproteinase with thrombospondin type I motifs 4 and a disintegrin and metalloproteinase with thrombospondin type I motifs 5 expressions were decreased by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. The combination of the three compounds was significantly more efficient to inhibit interleukin-1β stimulated matrix metalloproteinase-3 expression than curcuminoids extract alone. In interleukin-1β-stimulated human chondrocytes, nitric oxide, interleukin-6 and matrix metalloproteinase 3 productions were significantly reduced by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. These findings indicate that a mixture of curcuminoids extract, hydrolyzed collagen and green tea extract has beneficial effects on chondrocytes culture in inflammatory conditions and provide a preclinical basis for the in vivo testing of this mixture.

Bovine collagen peptides compounds promote the proliferation and differentiation of MC3T3-E1 pre-osteoblasts

Objective

Collagen peptides (CP) compounds, as bone health supplements, are known to play a role in the treatment of osteoporosis. However, the molecular mechanisms of this process remain unclear. This study aimed to investigate the effects of bovine CP compounds on the proliferation and differentiation of MC3T3-E1 cells.

Methods

Mouse pre-osteoblast cell line MC3T3-E1 subclone 4 cells were treated with bovine CP compounds. Cell proliferation was analyzed by MTT assays and the cell cycle was evaluated by flow cytometry scanning. Furthermore, MC3T3-E1 cell differentiation was analyzed at the RNA level by real-time PCR and at the protein level by western blot analysis for runt-related transcription factor 2 (Runx2), a colorimetric p-nitrophenyl phosphate assay for alkaline phosphatase (ALP), and ELISA for osteocalcin (OC). Finally, alizarin red staining for mineralization was measured using Image Software Pro Plus 6.0.

Results

Cell proliferation was very efficient after treatment with different concentrations of bovine CP compounds, and the best concentration was 3 mg/mL. Bovine CP compounds significantly increased the percentage of MC3T3-E1 cells in G₂/S phase. Runx2 expression, ALP activity, and OC production were significantly increased after treatment with bovine CP compounds for 7 or 14 days. Quantitative analyses with alizarin red staining showed significantly increased mineralization of MC3T3-E1 cells after treatment with bovine CP compounds for 14 or 21 days.

Conclusions

Bovine CP compounds increased osteoblast proliferation, and played positive roles in osteoblast differentiation and mineralized bone matrix formation. Taking all the experiments together, our study indicates a molecular mechanism for the potential treatment of osteoarthritis and osteoporosis.

Suitability of porcine chondrocyte micromass culture to model osteoarthritis in vitro

In vitro tissue models are useful tools for the development of novel therapy strategies in cartilage repair and care. The limited availability of human primary tissue and high costs of animal models hamper preclinical tests of innovative substances and techniques. In this study we tested the potential of porcine chondrocyte micromass cultures to mimic human articular cartilage and essential aspects of osteoarthritis (OA) in vitro. Primary chondrocytes were enzymatically isolated from porcine femoral condyles and were maintained in 96-multiwell format to establish micromass cultures in a high-throughput scale. Recombinant porcine tumor necrosis factor alpha (TNF-α) was used to induce OA-like changes documented on histological (Safranin O, collagen type II staining), biochemical (hydroxyproline assay, dimethylmethylene blue method), and gene expression level (Affymetrix porcine microarray, real time PCR) and were compared with published data from human articular cartilage and human micromass cultures. After 14 days in micromass culture, porcine primary chondrocytes produced ECM rich in proteoglycans and collagens. On gene expression level, significant correlations of detected genes with porcine cartilage (r = 0.90), human cartilage (r = 0.71), and human micromass culture (r = 0.75) were observed including 34 cartilage markers such as COL2A1, COMP, and aggrecan. TNF-α stimulation led to significant proteoglycan (-75%) and collagen depletion (-50%). Comparative expression pattern analysis revealed the involvement of catabolic enzymes (MMP1, -2, -13, ADAM10), chemokines (IL8, CCL2, CXCL2, CXCL12, CCXL14), and genes associated with cell death (TNFSF10, PMAIPI, AHR) and skeletal development (GPNMB, FRZB) including transcription factors (WIF1, DLX5, TWIST1) and growth factors (IGFBP1, -3, TGFB1) consistent with published data from human OA cartilage. Expression of genes related to cartilage ECM formation (COL2A1, COL9A1, COMP, aggrecan) as well as hypertrophic bone formation (COL1A1, COL10A1) was predominantly found decreased. These findings indicating significant parallels between human articular cartilage and the presented porcine micromass model and vice versa confirm the applicability of known cartilage marker and their characteristics in the porcine micromass model. TNF-α treatment enabled the initiation of typical OA reaction patterns in terms of extensive ECM loss, cell death, formation of an inflammatory environment through the induction of genes coding for chemokines and enzymes, and the modulation of genes involved in skeletal development such as growth factors, transcription factors, and cartilage ECM-forming genes. In conclusion, the porcine micromass model represents an alternative tissue platform for the evaluation of innovative substances and techniques for the treatment of OA.

Potential application of hydrolyzed fish collagen for inducing the multidirectional differentiation of rat bone marrow mesenchymal stem cells

Hydrolyzed fish collagen (HFC) has recently attracted considerable attention because of its outstanding bioactivity. However, few studies have been performed to determine the biological effects of HFC on bone marrow mesenchymal stem cells (BMSCs), which are often used in regenerative medicine. In this study, the molecular weight, amino acid composition, and contact angle of HFC were measured. The influence of HFC on cell viability and the multidirectional differentiation of BMSCs into osteogenic, endothelial, adipogenic, chondrogenic, and neural lineages were also assessed. Furthermore, the mechanism by which HFC promotes osteogenesis was investigated at the protein level. The molecular weight of HFC ranged from 700 to 1300 Da, the contact angle of HFC was approximately 26°, and HFC was found to be composed of various amino acids, including glycine, proline, and hydroxyproline. At a concentration of 0.2 mg/mL, HFC promoted cell viability, and significantly up-regulated the expression of osteogenic markers (RUNX2, ALP, OPN, and OCN), as well as endothelial markers (CD31, VE-cadherin, and VEGFR2). Western blot results indicated that treatment of BMSCs with 0.2 mg/mL HFC could activate the MAPK/ERK signaling pathway and then increase the protein level of RUNX2, while treatment with PD98059, a specific inhibitor of ERK1/2, could significantly inhibit the expression of P-ERK and RUNX2. Interestingly, real-time PCR demonstrated that HFC inhibited the expression of adipogenic markers (LPL and ADFP) and chondrogenic markers (aggrecan and COLII), whereas it had no effect on neural differentiation markers (MAP2 and β3-tubulin). In summary, this study suggests that without the use of any additional inducing reagent, HFC has the potential to actively promote osteogenic and endothelial differentiation because of its high hydrophilicity and the optimal extracellular microenvironment supplied by its amino acids. This research also revealed that HFC inhibited adipogenic and chondrogenic differentiation, but it had no influence on the neural differentiation of rat bone marrow mesenchymal stem cells (rBMSCs).

Osteogenic activity of collagen peptide via ERK/MAPK pathway mediated boosting of collagen synthesis and its therapeutic efficacy in osteoporotic bone by back-scattered electron imaging and microarchitecture analysis

Collagen hydrolysate (CH) has been reported to exhibit a positive effect on bone. In the present study, the in vitro effects of CH (<3 kDa) were examined and the in vivo experiments confirmed the positive effects of CH in ovariectomized (OVX) rats. Bone mineral density (BMD) was examined by DXA analysis. Scanning electron microscopic analysis and quantitative 3D-color backscattered electrons imaging analysis were performed on the lumbar vertebrae. CH increased osteoblastic cell proliferation and alkaline phosphatase activity in a dose-dependent manner. Collagen synthesis and collagen, type1, alpha1 (COL1A1) gene expression were also increased by CH treatment. Furthermore, CH-induced COL1A1 gene expression was completely abolished by extracellular signal-regulated kinase (ERK) inhibitor, suggesting the involvement of ERK/MAPK signaling for transcriptional effects on COL1A1 expression. OVX rats supplemented with CH showed osteoprotective effects as the BMD levels were increased compared with control. Moreover, CH prevented the trabecular bone loss induced by OVX and improved the microarchitecture of lumbar vertebrae. CH administration dose-dependently reduced the serum procollagen type I N-terminal propeptide level, which was elevated by OVX. The present study suggests that CH isolated in this study is a promising alternative to current therapeutic agents for the management of osteoporosis.