Isolation and Biochemical Properties of Type II Collagen from Blue Shark (Prionace glauca) Cartilage.

Numerous studies have shown that type II collagen (CII) has a potential role in the treatment of rheumatoid arthritis. However, most of the current studies have used terrestrial animal cartilage as a source of CII extraction, with fewer studies involving marine organisms. Based on this background, collagen (BSCII) was isolated from blue shark (Prionace glauca) cartilage by pepsin hydrolysis and its biochemical properties including protein pattern, total sugar content, microstructure, amino acid composition, spectral characteristics and thermal stability were further investigated in the present study. The SDS-PAGE results confirmed the typical characteristic of CII, comprising three identical α1 chains and its dimeric ß chain. BSCII had the fibrous microstructure typical of collagen and an amino acid composition represented by high glycine content. BSCII had the typical UV and FTIR spectral characteristics of collagen. Further analysis revealed that BSCII had a high purity, while its secondary structure comprised 26.98% of ß-sheet, 35.60% of ß-turn, 37.41% of the random coil and no α-helix. CD spectra showed the triple helical structure of BSCII. The total sugar content, denaturation temperature and melting temperature of BSCII were (4.20 ± 0.03)%, 42 °C and 49 °C, respectively. SEM and AFM images confirmed a fibrillar and porous structure of collagen and denser fibrous bundles formed at higher concentrations. Overall, CII was successfully extracted from blue shark cartilage in the present study, and its molecular structure was intact. Therefore, blue shark cartilage could serve as a potential source for CII extraction with applications in biomedicine.

Analysis of N-glycosylation protein of Kashin-Beck disease chondrocytes derived from induced pluripotent stem cells based on label-free strategies with LC-MS/MS.

We aimed to compare N-glycosylation proteins in Kashin-Beck disease (KBD) chondrocytes and normal chondrocytes derived from induced pluripotent stem cells (iPSCs). KBD and normal iPSCs were reprogrammed from human KBD and normal dermal fibroblasts, respectively. Subsequently, chondrocytes were differentiated from KBD and normal iPSCs separately. Immunofluorescence was utilized to assay the protein markers of iPSCs and chondrocytes. Differential N-glycosylation proteins were screened using label-free strategies with LC-MS/MS. Bioinformatics analyses were utilized to interpret the functions of differential N-glycosylation proteins. Immunofluorescence staining revealed that both KBD-iPSCs and normal-iPSCs strongly expressed pluripotency markers OCT4 and NANOG. Meanwhile, chondrocyte markers collagen II and SOX9 are presented in KBD-iPSC-chondrocytes and normal-iPSC-chondrocytes. We obtained 87 differential N-glycosylation sites which corresponded to 68 differential proteins, which were constructed into 1 cluster. We obtained collagen type I trimer and 9 other biological processes; polysaccharide binding and 9 other molecular functions; regulation of transcription by RNA polymerase II and 9 other cellular components from GO; the Pl3K-Akt signaling pathway and 9 other KEGG pathways; peroxisome and 7 other subcellular locations; and integrin alpha chain, C-terminal cytoplasmic region, conserved site and 9 other classifications of domain annotations, and 2 networks. FGFR3 and LRP1 are expressed at higher levels in KBD-iPSC-chondrocytes, while the expressions of COL2A1, TIMP1, UNC5B, NOG, LEPR, and ITGA1 were down-regulated in KBD-iPSC-chondrocytes. The differential expressions of these N-glycosylation proteins may lead to the abnormal function of KBD chondrocytes.

Low levels of type II collagen formation (PRO-C2) are associated with response to sprifermin: a pre-defined, exploratory biomarker analysis from the FORWARD study.

OBJECTIVE: Osteoarthritis (OA) is characterized by the gradual loss of cartilage. Sprifermin, a recombinant FGF18, is being developed as a cartilage anabolic drug. PRO-C2 is a serum marker of type II collagen formation and low levels have been shown to be prognostic of radiographic progression. The aim of the study was to investigate whether the patient groups with either high or low PRO-C2 levels responded differently to sprifermin. DESIGN: PRO-C2 was measured in synovial fluid (SF) (n = 59) and serum samples (n = 225) from participants of the FORWARD study, a 2-year phase IIb clinical trial testing the efficacy of intra-articular (IA) sprifermin over placebo. The difference between sprifermin and placebo in respect to in change cartilage thickness (measured by quantitative (q) MRI) was analyzed in groups with either high or low (3rd vs 1st-2nd tertiles) baseline serum PRO-C2 levels. RESULTS: SF levels of PRO-C2 increased over time in response to sprifermin, but not to placebo. In the placebo arm, significantly (p = 0.005) more cartilage was lost in the low vs high PRO-C2 group over the 2-year period. The contrast between sprifermin and placebo was significant (p < 0.001), ranging from 0.104 mm at week 26 to 0.229 mm at week 104 in the low PRO-C2 group. This result was not significant in the high PRO-C2 group ranging from -0.034 to 0.142. CONCLUSIONS: Patients with low serum PRO-C2 levels lost more cartilage thickness over time and grew more cartilage in response to sprifermin vs a placebo when compared to patients with high PRO-C2 levels.

Anterior cruciate ligament reconstruction reinitiates an inflammatory and chondrodegenerative process in the knee joint.

Anterior cruciate ligament (ACL) injury leads to a sustained increase in synovial fluid concentrations of inflammatory cytokines and biomarkers of cartilage breakdown. While this has been documented post-injury, it remains unclear whether ACL reconstruction surgery contributes to the inflammatory process and/or cartilage breakdown. This study is a secondary analysis of 14 patients (nine males/five females, mean age = 9, mean BMI = 28) enrolled in an IRB-approved randomized clinical trial. Arthrocentesis was performed at initial presentation (mean = 6 days post-injury), immediately prior to surgery (mean = 23 days post-injury), 1-week post-surgery, and 1-month post-surgery. Enzyme-linked immunosorbant assay kits were used to determine concentrations of carboxy-terminal telopeptides of type II collagen (CTXII), interleukin-6 (IL-6), and IL-1ß in the synovial fluid. The log-transformed IL-1ß was not normally distributed; therefore, changes between time points were evaluated using a non-parametric Kruskal-Wallis one-way ANOVA. IL-1ß concentrations significantly increased from the day of surgery to the first postoperative time point (P ≤ .001) and significantly decreased at the 4-week postoperative visit (P = .03). IL-1ß concentrations at the 4-week postoperative visit remained significantly greater than both preoperative time points (P > .05). IL-6 concentrations at 1-week post-surgery were significantly higher than at initial presentation (P = .013), the day of surgery (P < .001), and 4 weeks after surgery (P = .002). CTX-II concentrations did not differ between the first three-time points (P > .99) but significantly increased at 4 weeks post-surgery (P < .01). ACL reconstruction appears to reinitiate an inflammatory response followed by an increase in markers for cartilage degradation. ACL reconstruction appears to initiate a second "inflammatory hit" resulting in increased chondral breakdown suggesting that post-operative chondroprotection may be needed.

Extraction and Characterization of Collagen from Elasmobranch Byproducts for Potential Biomaterial Use.

With the worldwide increase of fisheries, fish wastes have had a similar increase, alternatively they can be seen as a source of novel substances for the improvement of society's wellbeing. Elasmobranchs are a subclass fished in high amounts, with some species being mainly bycatch. They possess an endoskeleton composed mainly by cartilage, from which chondroitin sulfate is currently obtained. Their use as a viable source for extraction of type II collagen has been hypothesized with the envisaging of a biomedical application, namely in biomaterials production. In the present work, raw cartilage from shark (Prionace glauca) and ray (Zeachara chilensis and Bathyraja brachyurops) was obtained from a fish processing company and submitted to acidic and enzymatic extractions, to produce acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC). From all the extractions, P. glauca PSC had the highest yield (3.5%), followed by ray ASC (0.92%), ray PSC (0.50%), and P. glauca ASC (0.15%). All the extracts showed similar properties, with the SDS-PAGE profiles being compatible with the presence of both type I and type II collagens. Moreover, the collagen extracts exhibited the competence to maintain their conformation at human basal temperature, presenting a denaturation temperature higher than 37 °C. Hydrogels were produced using P. glauca PSC combined with shark chondroitin sulfate, with the objective of mimicking the human cartilage extracellular matrix. These hydrogels were cohesive and structurally-stable at 37 °C, with rheological measurements exhibiting a conformation of an elastic solid when submitted to shear strain with a frequency up to 4 Hz. This work revealed a sustainable strategy for the valorization of fisheries' by-products, within the concept of a circular economy, consisting of the use of P. glauca, Z. chilensis, and B. brachyurops cartilage for the extraction of collagen, which would be further employed in the development of hydrogels as a proof of concept of its biotechnological potential, ultimately envisaging its use in marine biomaterials to regenerate damaged cartilaginous tissues.

Structural feature and self-assembly properties of type II collagens from the cartilages of skate and sturgeon.

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted and purified from the cartilages of skate and sturgeon. Their typical structure and physicochemical properties were evaluated by circular dichroism (CD), X-ray diffraction (XRD), and so on. Results showed that the extracted collagen was likely identified as collagen-II composed of three α-chains (135 kDa), with the typical peptide sequence of Gly-X-Y. It showed the collagen retained the native and intact triple helical structure, and its intensity ratio of the positive and negative absorption peaks (Rpn) was 0.19-0.25. In addition, the extracted collagen exhibited obvious self-assembly behavior with the concentration above 0.3 mg/mL, the adjustment of pH 7.4-7.6 and the NaCl concentration of 120 mmol/L. The critical aggregate mass concentrations of pepsin-soluble collagens from skate and sturgeon were 0.93 and 0.86 g/L, respectively. Therefore, collagens from skate and sturgeon cartilages have potential commercial application.

The Effects of Age and Cell Isolation on Collagen II Synthesis by Articular Chondrocytes: Evidence for Transcriptional and Posttranscriptional Regulation.

Adult articular cartilage synthesises very little type II collagen in comparison to young cartilage. The age-related difference in collagen II synthesis is poorly understood. This is the first systematic investigation of age-related differences in extracellular matrix synthesis in fresh articular cartilage and following isolation of chondrocytes. A histological comparison of 3-year-old skeletally mature and 6-month-old juvenile porcine cartilage was made. Differences in collagen II, aggrecan, and Sox5, 6, and 9 mRNA and protein expression and mRNA stability were measured. Adult cartilage was found to be thinner than juvenile cartilage but with similar chondrocyte density. Procollagen α1(II) and Sox9 mRNA levels were 10-fold and 3-fold reduced in adult cartilage. Sox9 protein was halved and collagen II protein synthesis was almost undetectable and calculated to be at least 30-fold reduced. Aggrecan expression did not differ. Isolation of chondrocytes caused a drop in procollagen α1(II) and Sox9 mRNA in both adult and juvenile cells along with a marked reduction in Sox9 mRNA stability. Interestingly, juvenile chondrocytes continued to synthesise collagen II protein with mRNA levels similar to those seen in adult articular cartilage. Age-related differences in collagen II protein synthesis are due to both transcriptional and posttranscription regulation. A better understanding of these regulatory mechanisms would be an important step in improving current cartilage regeneration techniques.

Sprifermin (rhFGF18) versus vehicle induces a biphasic process of extracellular matrix remodeling in human knee OA articular cartilage ex vivo.

Sprifermin, recombinant human fibroblast growth factor 18 (rhFGF18), induces cartilage regeneration in knees of patients with osteoarthritis (OA). We hypothesized that a temporal multiphasic process of extracellular matrix (ECM) degradation and formation underlie this effect. We aimed to characterize the temporal ECM remodeling of human knee OA articular cartilage in response to sprifermin treatment. Articular cartilage explants from patients with knee OA (npatients = 14) were cultured for 70 days, with permanent exposure to sprifermin (900, 450, 225 ng/mL), FGF18 (450 ng/mL), insulin-like growth factor-1 (100 ng/mL, positive control) or vehicle (nreplicates/treatment/patient = 2). Metabolic activity (AlamarBlue) and biomarkers of type IIB collagen (PIIBNP) formation (Pro-C2 enzyme-linked immunosorbent assay [ELISA]) and aggrecanase-mediated aggrecan neo-epitope NITEGE (AGNx1 ELISA) were quantified once a week. At end of culture (day 70), gene expression (quantitative reverse transcription polymerase chain reaction) and proteoglycan content (Safranin O/Fast green staining) were quantified. The cartilage had continuously increased metabolic activity, when treated with sprifermin/FGF18 compared to vehicle. During days 7-28 PIIBNP was decreased and NITEGE was increased, and during days 35-70 PIIBNP was increased. At end of culture, the cartilage had sustained proteoglycan content and relative expression of ACAN < COL2A1 < SOX9 < COL1A1, indicating that functional chondrocytes remained in the explants. Sprifermin induces a temporal biphasic cartilage remodeling in human knee OA articular cartilage explants, with early-phase increased aggrecanase activity and late-phase increased type II collagen formation.

Epigenetic modulation of macrophage polarization prevents lumbar disc degeneration.

Inflammation plays an essential role in the development of lumbar disc degeneration (LDD), although the exact effects of macrophage subtypes on LDD remain unclear. Based on previous studies, we hypothesized that M2-polarization of local macrophages and simultaneous suppression of their production of fibrotic transforming growth factor beta 1 (TGFß1) could inhibit progression of LDD. Thus, we applied an orthotopic injection of adeno-associated virus (AAV) carrying shRNA for DNA Methyltransferase 1 (DNMT1) and/or shRNA for TGFß1 under a macrophage-specific CD68 promoter to specifically target local macrophages in a mouse model for LDD. We found that shDNMT1 significantly reduced levels of the pro-inflammatory cytokines TNFα, IL-1ß and IL-6, significantly increased levels of the anti-inflammatory cytokines IL-4 and IL-10, significantly increased M2 macrophage polarization, significantly reduced cell apoptosis in the disc degeneration zone and significantly reduced LDD-associated pain. The anti-apoptotic and anti-pain effects were further strengthened by co-application of shTGFß1. Together, these data suggest that M2 polarization of macrophages induced by both epigenetic modulation and suppressed production and release of TGFß1 from polarized M2 macrophages, may have a demonstrable therapeutic effect on LDD.

COL2A1 and Caspase-3 as Promising Biomarkers for Osteoarthritis Prognosis in an Equus asinus Model.

Osteoarthritis (OA) is one of the most degenerative joint diseases in both human and veterinary medicine. The objective of the present study was the early diagnosis of OA in donkeys using a reliable grading of the disease based on clinical, chemical, and molecular alterations. OA was induced by intra-articular injection of 25 mg monoiodoacetate (MIA) as a single dose into the left radiocarpal joint of nine donkeys. Animals were clinically evaluated through the assessment of lameness score, radiographic, and ultrasonographic findings for seven months. Synovial fluid and cartilage samples were collected from both normal and diseased joints for the assessment of matrix metalloproteinases (MMPs) activity, COL2A1 protein expression level, and histopathological and immunohistochemical analysis of Caspase-3. Animals showed the highest lameness score post-induction after one week then decreased gradually with the progression of radiographical and ultrasonographic changes. MMP activity and COL2A1 and Caspase-3 expression increased, accompanied by articular cartilage degeneration and loss of proteoglycan. OA was successfully graded in Egyptian donkeys, with the promising use of COL2A1and Caspase-3 for prognosis. However, MMPs failed to discriminate between early and late grades of OA.

[Relationship between supernatant cytokines and expression of markers of epitelial-mesenchymal transition of invasive breast carcinoma of non-specific lymphynosis type]. / Vzaimosviaz' mezhdu tsitokinami supernatantov i ékspressiei markerov épitelial'no-mezenkhimal'nogo perekhoda bioptatov invazivnoi kartsinomy molochnoi zhelezy nespetsificheskogo tipa pri limfogennom metastazirovanii.

The relationship between the content of supernatant cytokines and the expression of non-specific type of markers of epithelial-mesenchymal transition markers in the presence (group II) and the absence of lymphogenous metastasis (group I) were studied in biopsy specimens of mammary invasive breast carcinoma. The concentrations of TNF-α, IFN-γ, G-CSF, GM-CSF, VEGF, MCP-1, IL-2, IL-4, IL-6, IL-8, IL-10, IL-17, IL-18, IL-1ß and IL-1Ra, as well as the expression of immunohistochemical (IHC) markers of the epithelial-mesenchymal transition - cadherin-E (CDH1), ß-1 integrin (CD29) and type II collagen (CII) were assayed. Results have shown that patients of these groups statistically significantly differed in spontaneous production of IL-18 and G-CSF, in terms of the index of the effect of the polyclonal activator on G-CSF production. There was a correlation between the parameter of CII expression in tumor tissue and the production of cytokines by tumor biopsy specimens; it was characteristic of all patients with invasive carcinoma of a non-specific type, and correlations, both direct and reverse between the expression indices of CDH1, CD29 and cytokine production varied depending on the presence or the absence of lymphogenous metastasis. The study revealed the features of the correlation between the production of cytokines by the tumor, its microenvironment and the expression of IHC markers of the epithelial-mesenchymal transition in patients with invasive non-specific breast carcinoma in the presence and absence of lymphogenous metastasis.

Optimization of immunohistochemical detection of collagen type II in osteochondral sections by comparing decalcification and antigen retrieval agent combinations.

Bone containing tissues such as osteochondral joint are resistant to routine tissue processing, therefore require decalcification. This technique causes removal of mineral salts, but in the process may macerate the organic tissue, hence the need for tissue fixation. Such severe processing demands careful antigen retrieval to necessitate optimal staining. The aim of our study was to compare five different antigen retrieval protocols (heat retrieval and protein digestion) following decalcification of rabbit knee joints using two different techniques (20% formic acid and 10% ethylenediamine-tetra acetic acid: EDTA). Osteochondral sections were compared based on time required for decalcification, ease of sectioning, morphological integrity using HE staining and antigen preservation (Collagen type II) using immunohistochemistry. The two decalcification solutions did not impair the tissue morphology and ease of sectioning. Joints processed with formic acid decalcified four times faster than EDTA. Among the five antigen retrieval approaches, maximal collagen II uptake with minimal nonspecific staining was found with protein digestion (pronase and hyaluronidase) in both formic acid and EDTA sections. For osteo-chondral sections, we recommend using 10% EDTA for decalcification and pronase plus hyaluronidase for antigen retrieval if maintaining tissue morphology is crucial, whereas if time is of the essence, 20% FA with pronase plus hyaluronidase is the faster option while still preserving structural integrity. Clin. Anat. 33:343-349, 2020. © 2019 Wiley Periodicals, Inc.

Physical Activity Prevents Cartilage Degradation: A Metabolomics Study Pinpoints the Involvement of Vitamin B6.

Osteoarthritis (OA) is predominantly characterized by the progressive degradation of articular cartilage, the connective tissue produced by chondrocytes, due to an imbalance between anabolic and catabolic processes. In addition, physical activity (PA) is recognized as an important tool for counteracting OA. To evaluate PA effects on the chondrocyte lineage, we analyzed the expression of SOX9, COL2A1, and COMP in circulating progenitor cells following a half marathon (HM) performance. Therefore, we studied in-depth the involvement of metabolites affecting chondrocyte lineage, and we compared the metabolomic profile associated with PA by analyzing runners' sera before and after HM performance. Interestingly, this study highlighted that metabolites involved in vitamin B6 salvage, such as pyridoxal 5'-phosphate and pyridoxamine 5'-phosphate, were highly modulated. To evaluate the effects of vitamin B6 in cartilage cells, we treated differentiated mesenchymal stem cells and the SW1353 chondrosarcoma cell line with vitamin B6 in the presence of IL1ß, the inflammatory cytokine involved in OA. Our study describes, for the first time, the modulation of the vitamin B6 salvage pathway following PA and suggests a protective role of PA in OA through modulation of this pathway.

Continuous preparation and characterization of immunomodulatory peptides from type II collagen by a novel immobilized enzyme membrane reactor with improved performance.

In this study, a novel method of continuous coupling of immobilized enzymatic hydrolysis reactor and membrane separation (CIEH-MS) was used to isolate the immunomodulatory peptides from type II collagen (CII) in chick sternal cartilage. The immobilized neutral protease was successfully prepared with an activity of 400.5 U/g. The CIEH-MS system loaded with immobilized neutral protease had high operational stability with enzyme decay constant of 0.0077 and half-life of 89.61 hr. Using a CIEH-MS system, the immunomodulatory peptides were obtained with lymphocyte proliferation of 66.23%, peptide yield of 23.43%, degree of hydrolysis (DH) of 22.41%, and permeate flux of 6.17 L/m2 h. The peptide fractions were further purified and the P3-2-4 fraction (RGQLGPM) with 760.4 Da molecular weights exhibited the highest lymphocyte proliferation activity (85.54%) and binding ability to human leukocyte antigen-DRB1 (HLA-DRB1) molecules (133.2 ng/ml). The results demonstrated that CIEH-MS system is an effective way to obtain immunomodulatory peptides from CII. PRACTICAL APPLICATIONS: Chick sternal cartilage is one of the by-products of meat processing, and it is often discarded as waste or used for low-value purposes. CII is the most abundant collagen in chick sternal cartilage, and recently studies have demonstrated that CII peptides possess the ability to induce immunologic tolerance for the treatment of chronic disease. In order to find potential applications for this by-product, immunomodulatory peptides from CII hydrolysates in chick sternal cartilage were isolated using a novel CIEH-MS system. The result showed that CII peptides exhibited a high immunomodulatory activity, and had a potential application in functional foods and medical fields.

Letter to the editor UC-II® Undenatured type II collagen: update to analytical methods.

Supplementation with UC-II® undenatured type II collagen has been shown to provide joint health benefits for both healthy adults and adults with knee osteoarthritis in controlled clinical trials. These trials used UC-II® materials with undenatured type II collagen characterized by an ELISA method that utilizes a monoclonal antibody specific for epitopes expressed by undenatured type II collagen protein only. In 2014, we modified the sample preparation part of the ELISA method in order to reduce the amount of time devoted to this procedure. We undertook these modifications in order to provide commercial manufacturers with a streamlined assay methodology better aligned with their product testing requirements. In doing so, it altered the percent of undenatured collagen now reported for UC-II® undenatured type II collagen. The intent of this letter is to clarify that the UC-II® materials used in the published clinical research cited herein, and the commercially available ingredient, remain identical and to describe the rationale for the change in the extraction method.

Use of Allogeneic Hypoxic Mesenchymal Stem Cells For Treating Disc Degeneration in Rabbits.

Intervertebral discs (IVDs) are important biomechanical components of the spine. Once degenerated, mesenchymal stem cell (MSC)-based therapies may aid in the repair of these discs. Although hypoxic preconditioning enhances the chondrogenic potential of MSCs, it is unknown whether bone marrow MSCs expanded under hypoxic conditions (1% O2 , here referred to as hypoxic MSCs) are better than bone marrow MSCs expanded under normoxic conditions (air, here referred to as normoxic MSCs) with regards to disc regeneration capacity. The purpose of this study was to compare the therapeutic effects of hypoxic and normoxic MSCs in a rabbit needle puncture degenerated disc model after intra-disc injection. Six weeks after needle puncture, MSCs were injected into the IVD. A vehicle-treated group and an un-punctured sham-control group were included as controls. The tissues were analyzed by histological and immunohistochemical methods 6 and 12 weeks post-injection. At 6 and 12 weeks, less disc space narrowing was evident in the hypoxic MSC-treated group compared to the normoxic MSC-treated group. Significantly better histological scores were observed in the hypoxic MSC group. Discs treated with hypoxic MSCs also demonstrated significantly better extracellular matrix deposition in type II and XI collagen. Increased CD105 and BMP-7 expression were also observed upon injection of hypoxic MSCs. In conclusion, hypoxic MSC injection was more effective than normoxic MSC injection for reducing IVD degeneration progression in vivo. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1440-1450, 2019.

GPDPLQ1237-A Type II Collagen Neo-Epitope Biomarker of Osteoclast- and Inflammation-Derived Cartilage Degradation in vitro.

C-telopeptide of type II collagen (CTX-II) has been shown to be a highly relevant biomarker of cartilage degradation in human rheumatic diseases, if measured in synovial fluid or urine. However, serum or plasma CTX-II have not been demonstrated to have any clinical utility to date. Here, we describe the GPDPLQ1237 ELISA which targets the EKGPDPLQ↓ neo-epitope, an elongated version of the CTX-II neo-epitope (EKGPDP↓), speculated to be a blood-precursor of CTX-II generated by the cysteine protease cathepsin K. Human osteoclast cartilage resorption cultures as well as oncostatin M and tumour necrosis factor α-stimulated bovine cartilage explant cultures were used to validate GPDPLQ1237 biologically by treating the cultures with the cysteine protease inhibitor E-64 and/or the matrix metalloproteinase (MMP) inhibitor GM6001 to assess the potential contributions of these two protease classes to GPDPLQ1237 release. Cartilage resorption-derived GPDPLQ1237 release was inhibited by E-64 (72.1% inhibition), GM6001 (75.5%), and E-64/GM6001 (91.5%), whereas CTX-II release was inhibited by GM6001 (87.0%) but not by E-64 (5.5%). Cartilage explant GPDPLQ1237 and CTX-II release were both fully inhibited by GM6001 but were not inhibited by E-64. No clinically relevant GPDPLQ1237 reactivity was identified in human serum, plasma, or urine from healthy donors or arthritis patients. In conclusion, the GPDPLQ1237 biomarker is released during osteoclast-derived cysteine protease- and MMP-mediated cartilage degradation in vitro, whereas CTX-II release is mediated by MMPs and not by cysteine proteases, as well as from MMP-mediated cartilage degradation under a pro-inflammatory stimulus. These findings suggest that GPDPLQ1237 may be relevant in diseases with pathological osteoclast activity and cartilage degradation. Further studies are required to validate the neo-epitope in human samples.

Effect of culture duration on chondrogenic preconditioning of equine bone marrow mesenchymal stem cells in self-assembling peptide hydrogel.

Ex vivo induction of chondrogenesis is a promising approach to improve upon the use of bone marrow mesenchymal stem cells (MSCs) for cartilage tissue engineering. This study evaluated the potential to induce chondrogenesis with days of culture in chondrogenic medium for MSCs encapsulated in self-assembling peptide hydrogel. To simulate the transition from preconditioning culture to implantation, MSCs were isolated from self-assembling peptide hydrogel into an individual cell suspension. Commitment to chondrogenesis was evaluated by seeding preconditioned MSCs into agarose and culturing in the absence of the chondrogenic cytokine transforming growth factor beta (TGFß). Positive controls consisted of undifferentiated MSCs seeded into agarose and cultured in medium containing TGFß. Three days of preconditioning was sufficient to produce chondrogenic MSCs that accumulated ∼75% more cartilaginous extracellular matrix than positive controls by day 17. However, gene expression of type X collagen was ∼65-fold higher than positive controls, which was attributed to the absence of TGFß. Potential induction of immunogenicity with preconditioning culture was indicated by expression of major histocompatibility complex class II (MHCII), which was nearly absence in undifferentiated MSCs, and ∼7% positive for preconditioned cells. These data demonstrate the potential to generate chondrogenic MSCs with days of self-assembling peptide hydrogel, and the ability to readily recover an individual cell suspension that is suited for injectable therapies. However, continued exposure to TGFß may be necessary to prevent hypertrophy indicated by type X collagen expression, while immunogenicity may be a concern for allogeneic applications. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1368-1375, 2019.

Cartilage oligomeric matrix protein, C-terminal cross-linking telopeptide of type II collagen, and matrix metalloproteinase-3 as biomarkers for knee and hip osteoarthritis (OA) diagnosis: a systematic review and meta-analysis.

OBJECTIVE: This study was design to examine the diagnostic performance of cartilage oligomeric matrix protein (COMP), C-terminal cross-linking telopeptide of type II collagen (CTX-II), and matrix metalloproteinase-3 (MMP-3) as biomarker for knee and hip OA. METHODS: Systematic search on multiple databases was completed in January 2018 using certain keywords. COMP, CTX-II, MMP-3 levels in knee and hip OA patients and healthy individuals were collected and calculated. Differences between subgroups were expressed as standardized mean differences (SMD). Subgroup analyses were performed to compare COMP, CTX-II, and MMP-3 performance between measuring sources, genders, large and small sample size and diagnostic criteria for OA patients. RESULTS: A moderate performance of COMP in distinguishing between knee (SMD: 0.68; 95% confidence intervals (CI): 0.43-0.93; P < 0.0001) or hip (SMD: 0.25; 95% CI, 0.10, 0.40; P = 0.0008) OA patients and controls were found. CTX-II showed a moderated standardised mean differences (SMD) of 0.48 (95% CI, 0.32, 0.64; P < 0.0001) in the detection of knee OA and a large SMD of 0.76 (95% CI, 0.09, 1.42; P = 0.03) in diagnosing hip OA. A small SMD of 0.32 (95% CI, -0.03, 0.67; P = 0.07) was found for MMP-3 performance and the results did not reach statistic significance. Progression study revealed potential effectiveness of serum COMP in predicting OA progression. Subgroup analysis showed that serum COMP and urinary CTX-II performed better in male than female. Study size and diagnostic criteria did not significantly influence the pooled SMD, but they might be the sources of heterogeneity among studies. CONCLUSION: The overall results indicates that serum COMP and urinary CTX-II can distinguish between knee or hip OA patients and control subjects. Serum COMP is effective in predicting OA progression.Further researches with rigorous study design and a larger sample size are required to validate our findings.

Mesenchymal Stem Cells Induced by Microencapsulated Chondrocytes on Repairing of Intervertebral Disc Degeneration.

OBJECTIVE: To evaluate the therapeutic effects of mesenchymal stem cells induced by microencapsulated chondrocytes on repairing of intervertebral disc degeneration. METHODS: Rabbit chondrocytes and bone marrow-derived mesenchymal stem cells (MSC) were derived. Chondrocytes were microencapsulated by a microcapsule generator to produce microencapsulated chondrocytes (MEC). MSC were then co-cultured with MEC (MSC-MEC) and the properties and the therapeutic effects on repairing of intervertebral disc degeneration were studied. For the in vitro study, cell proliferation, type II collagen, and glycosaminoglycan (GAG) were studied. The MSC induced by chondrocytes in the Transwell system (MSC-MLC) and pure MSC were used as the control group. For the in vivo studied, MSC-MEC were implanted into the intervertebral disc degenerated (IDD) models, and the radiological images, biomechanical properties, collagen II, and histology of the discs were studied. The IDD, MSC, and MSC-MLC groups were used as the control group. RESULTS: In the in vitro study, no significant differences were found among the three groups, indicating that the microcapsule co-culture system will not affect the proliferation of MSC. The type II collagen quantity secreted by MSC-MEC was 23.57 ± 2.46 ng/µL, which was more than for MSC-MLC (15.14 ± 2.31 ng/µL) and MSC groups (4.17 ± 1.23 ng/µL, all P < 0.025). GAG secreted by MSC-MEC was 0.184 ± 0.006 mg/well, which was more than for the MSC-MLC (0.151 ± 0.011 mg/well) and MSC groups (0.023 ± 0.002 mg/well, all P < 0.025). In the in vivo study, no obvious degenerative or protrusive disc was found in the MSC-MEC group, while protrusive discs could be found in the MSC-MLC group, and both degenerative and protrusive discs were found in MSC and IDD groups, which indicated that the reparative effects of MSC-MEC on degenerated discs were better than for the control groups. Biomechanical properties of discs in the MSC-MEC group were maintained at all four time points (2nd, 4th, 8th, and 16th week after implantation). The compressive strength (CS) and the elastic modulus (EM) of MSC and IDD groups were consistently decreased. The CS of the MSC-MLC group was increased in the 4th week but decreased again in the 8th week, while the EM of the MSC-MLC group consistently decreased. Western blot results indicated that discs of the MSC-MEC group had more collagen II, which is an important component of discs. Histology staining showed that the nucleus pulposus of MSC-MEC was complete; no obvious fragment of component loss was found, while those of MSC-MLC, MSC, and IDD groups were widened, broken, and hollow. CONCLUSION: The microencapsulation method for half-contact co-culturing improves the differentiation extent of MSC, and MSC induced by chondrocytes could also be used for treatment of IDD.