Chondroitin sulfate increases hyaluronan production by human synoviocytes through differential regulation of hyaluronan synthases: Role of p38 and Akt

Apple Pomace Extract Induces Cell Proliferation and Increases Type I Collagen and Hyaluronan Production in Human Skin Fibroblasts In Vitro

Apple pomace is the residue left after apples are squeezed. The majority of pomace produced worldwide is produced by the apple manufacturing industry, however, most of the pomace produced by the industry is discarded. Apple pomace contains functional ingredients, such as polyphenols and triterpenoids, and exerts several beneficial effects on human health; however, studies on its cosmetic effects on the skin are lacking. Therefore, herein, we investigated the effects of apple pomace extract (APE) on human skin fibroblasts (HSFs) in vitro. When HSFs were cultured with the extract for 72 h, the number of HSFs increased at concentrations of 10 and 20 µg/mL. Transcriptome analysis and reverse transcription-quantitative PCR results revealed that the extract upregulated the expression of hyaluronan synthase (HAS) 1, HAS2, and HAS3 and downregulated the expression of HYAL1, a gene encoding the hyaluronan-degrading enzyme, in HSFs. Additionally, enzyme-linked immunosorbent assay revealed increased amounts of factors related to skin extracellular matrix, such as type I collagen and hyaluronic acid, secreted in the culture supernatant. The western blotting results suggested that the extract induced extracellular signal-regulated kinase and protein kinase B phosphorylation in HSFs. Additionally, several GO_Terms related to mitosis were detected in the Gene Ontology analysis. This is the first study to show that APE induces the proliferation of HSFs and production of factors related to skin anti-aging.

Hyaluronic Acid and Large Extracellular Vesicles (EVs) in Synovial Fluid and Plasma of Patients With End-Stage Arthritis: Positive Association of EVs to Joint Pain

OBJECTIVE

Hyaluronic acid (HA) in synovial fluid (SF) contributes to boundary lubrication with altered levels in osteoarthritis (OA) and rheumatoid arthritis (RA). SF extracellular vesicles (EVs) may participate in arthritis by affecting inflammation and cartilage degradation. It remains unknown whether HA and EVs display joint-specific alterations in arthritic SFs.

DESIGN

We investigated the numbers and characteristics of HA-particles and large EVs in SF from knees and shoulders of 8 OA and 8 RA patients and 8 trauma controls, and in plasma from 10 healthy controls and 11 knee OA patients. The plasma and SF HA concentrations were determined with a sandwich-type enzyme-linked sorbent assay, and EVs and HA-particles were characterized from plasma and unprocessed and centrifuged SFs with confocal microscopy. The data were compared according to diagnosis, location, and preanalytical processing.

RESULTS

The main findings were: (1) OA and RA SFs can be distinguished from trauma joints based on the distinctive profiles of HA-particles and large EVs, (2) there are differences in the SF HA and EV characteristics between shoulder and knee joints that could reflect their dissimilar mobility, weight-bearing, and shock absorption properties, (3) EV counts in SF and plasma can positively associate with pain parameters independent of age and body adiposity, and (4) low-speed centrifugation causes alterations in the features of HA-particles and EVs, complicating their examination in the original state.

CONCLUSIONS

Arthritis and anatomical location can affect the characteristics of HA-particles and large EVs that may have potential as biomarkers and effectors in joint degradation and pain.

Hyaluronic Acid-Based Injective Medical Devices: In Vitro Characterization of Novel Formulations Containing Biofermentative Unsulfated Chondroitin or Extractive Sulfated One with Cyclodextrins

Currently, chondroitin sulfate (CS) and hyaluronic acid (HA) pharma-grade forms are used for osteoarthritis (OA) management, CS as an oral formulations component, and HA as intra-articular injective medical devices. Recently, unsulfated chondroitin, obtained through biofermentative (BC) manufacturing, has been proposed for thermally stabilized injective preparation with HA. This study aimed to highlight the specific properties of two commercial injective medical devices, one based on HA/BC complexes and the other containing HA, extractive CS, and cyclodextrins, in order to provide valuable information for joint disease treatments. Their biophysical and biomechanical features were assayed; in addition, biological tests were performed on human pathological chondrocytes. Rheological measurements displayed similar behavior, with a slightly higher G' for HA/BC, which also proved superior stability to the hyaluronidase attack. Both samples reduced the expression of specific OA-related biomarkers such as NF-kB, interleukin 6 (IL-6), and metalloprotease-13 (MMP-13). Moreover, HA/BC better ensured chondrocyte phenotype maintenance by up-regulating collagen type 2A1 (COLII) and aggrecan (AGN). Notwithstanding, the similarity of biomolecule components, the manufacturing process, raw materials characteristics, and specific concentration resulted in affecting the biomechanical and, more interestingly, the biochemical properties, suggesting potential better performances of HA/BC in joint disease treatment.

EXOSOMES AND MICROVESICLES FROM ADIPOSE-DERIVED MESENCHYMAL STEM CELLS PROTECTS THE ENDOTHELIAL GLYCOCALYX FROM LPS INJURY

ABSTRACT

Introduction: Endothelial glycocalyx damage occurs in numerous pathological conditions and results in endotheliopathy. Extracellular vesicles, including exosomes and microvesicles, isolated from adipose-derived mesenchymal stem cells (ASCs) have therapeutic potential in multiple disease states; however, their role in preventing glycocalyx shedding has not been defined. We hypothesized that ASC-derived exosomes and microvesicles would protect the endothelial glycocalyx from damage by LPS injury in cultured endothelial cells. Methods : Exosomes and microvesicles were collected from ASC conditioned media by centrifugation (10,000 g for microvesicles, 100,000 g for exosomes). Human umbilical vein endothelial cells (HUVECs) were exposed to 1 μg/mL lipopolysaccharide (LPS). LPS-injured cells (n = 578) were compared with HUVECS with concomitant LPS injury plus 1.0 μg/mL of exosomes (n = 540) or microvesicles (n = 510) for 24 hours. These two cohorts were compared with control HUVECs that received phosphate-buffered saline only (n = 786) and HUVECs exposed to exosomes (n = 505) or microvesicles (n = 500) alone. Cells were fixed and stained with FITC-labeled wheat germ agglutinin to quantify EGX. Real-time quantitative reverse-transcription polymerase chain reaction was used on HUVECs cell lystate to quantify hyaluron synthase-1 (HAS1) expression. Results: Exosomes alone decreased endothelial glycocalyx staining intensity when compared with control (4.94 vs. 6.41 AU, P < 0.001), while microvesicles did not cause a change glycocalyx staining intensity (6.39 vs. 6.41, P = 0.99). LPS injury resulted in decreased glycocalyx intensity as compared with control (5.60 vs. 6.41, P < 0.001). Exosomes (6.85 vs. 5.60, P < 0.001) and microvesicles (6.35 vs. 5.60, P < 0.001) preserved endothelial glycocalyx staining intensity after LPS injury. HAS1 levels were found to be higher in the exosome (1.14 vs. 3.67 RE, P = 0.02) and microvesicle groups (1.14 vs. 3.59 RE, P = 0.02) when compared with LPS injury. Hyaluron synthase-2 and synthase-3 expressions were not different in the various experimental groups. Conclusions: Exosomes alone can damage the endothelial glycocalyx. However, in the presence of LPS injury, both exosomes and microvesicles protect the glycocalyx layer. This effect seems to be mediated by HAS1. Level of Evidence : Basic science study.

Enhancing effects of immobilized chondroitin sulfate on odontogenic differentiation of dental pulp stem cells and reparative dentin formation

OBJECTIVES

Chondroitin sulfate (CS) is a major proteoglycan involved in the mineralization of the organic matrix of dentin. In this study, the roles of CS immobilized in crosslinked collagen I hydrogels (CS-Col I) on odontogenic differentiation of dental pulp stem cells (DPSCs) and reparative dentin formation were investigated.

METHODS

Different concentrations of CS were incorporated into the genipin- crosslinked Col I hydrogels (CS-0.05, CS-0.1, and CS-0.2 respectively). The influences of CS on proliferation and odontogenic differentiation of DPSCs were investigated. Finally, the effect of the functionalized hydrogel on the formation of reparative dentin was analyzed in a rat pulp capping model in vivo.

RESULTS

CS improved the proliferation of DPSCs seeded on the hydrogels (p<0.05). CS also enhanced the mineralization activities and increased the expression levels of the odontogenic related proteins of DPSCs on day 7 and day 14 (p<0.05). In vivo, CS-0.1 hydrogel induced reparative dentin formation with higher quality compared to mineral trioxide aggregate (MTA).

CONCLUSION

CS immobilized in Col I hydrogels could induce odontogenic differentiation of DPSCs in vitro and promote homogeneous mineralized barrier formation in vivo. CS-Col I hydrogel has the potential for reparative dentin formation of high quality in direct pulp capping.

Molecular Fingerprint of Human Pathological Synoviocytes in Response to Extractive Sulfated and Biofermentative Unsulfated Chondroitins

Pharma-grade extractive chondroitin sulfate (CS) is widely used for osteoarthritis (OA) treatment. Recently, unsulfated biofermentative chondroitin (BC) proved positive effects in OA in vitro model. This study, based on primary pathological human synoviocytes, aimed to analyze, by a multiplex assay, a panel of OA-related biomarkers in response to short-term treatments with bovine (CS_b), pig (CS_p) and fish (CS_f) chondroitins, in comparison to BC. As expected, all samples had anti-inflammatory properties, however CS_b, CS_f and especially BC affected more cytokines and chemokines. Based on these results and molecular weight similarity, CS_f and BC were selected to further explore the synoviocytes' response. In fact, Western blot analyses showed CS_f and BC were comparable, downregulating OA-related biomarkers such as the proteins mTOR, NF-kB, PTX-3 and COMP-2. Proteomic analyses, performed by applying a nano-LC-MS/MS TMT isobaric labelling-based approach, displayed the modulation of both common and distinct molecules to chondroitin treatments. Thus, CS_f and BC modulated the biological mediators involved in the inflammation cascade, matrix degradation/remodeling, glycosaminoglycans' synthesis and cellular homeostasis. This study helps in shedding light on different molecular mechanisms related to OA disease that may be potentially affected not only by animal-source chondroitin sulfate but also by unsulfated biofermentative chondroitin.

A composite device for viscosupplementation treatment resistant to degradation by reactive oxygen species and hyaluronidase

Osteoarthritis (OA) is one of the most common musculoskeletal disorders in the world. OA is often associated with the loss of viscoelastic and tribological properties of synovial fluid (SF) due to degradation of hyaluronic acid (HA) by reactive oxygen species (ROS) and hyaluronidases. Viscosupplementation is one of the ways how to effectively restore SF functions. However, current viscosupplementation products provide only temporal therapeutic effect because of short biological half-life. In this article we describe a novel device for viscosupplementation (NV) based on the cross-linked tyramine derivative of HA, chondroitin sulfate (CS), and high molecular weight HA by online determination of viscoelastic properties loss during degradation by ROS and hyaluronidase. Rheological and tribological properties of developed viscosupplement were compared with HA solutions with different molecular weights in the range 500-2000 kDa, which are currently commonly used as medical devices for viscosupplementation treatment. Moreover, based on clinical practice and scientific literature all samples were also diluted by model OA SF in the ratio 1:1 (vol/vol) to better predict final properties after injection to the joint. The observed results confirmed that NV exhibits appropriate rheological properties (viscosity, elastic, and viscous moduli) comparable with healthy SF and maintain them during degradation for a significantly longer time than HA solutions with molecular weight in the range 500-2000 kDa and cross-linked material without CS.

Evaluation of unsulfated biotechnological chondroitin in a knee osteoarthritis mouse model as a potential novel functional ingredient in nutraceuticals and pharmaceuticals

Osteoarthritis is a very disabling disease that can be treated with both non-pharmacological and pharmacological approaches. In the last years, pharmaceutical-grade chondroitin sulfate (CS) and glucosamine emerged as symptomatic slow-acting molecules, effective in pain reduction and improved function in patients affected by osteoarthritis. CS is a sulfated glycosaminoglycan that is currently produced mainly by extraction from animal tissues, and it is commercialized as a pharmaceutical-grade ingredient and/or food supplement. However, public concern on animal product derivatives has prompted the search for alternative non-extractive production routes. Thus, different approaches were established to obtain animal-free natural identical CS. On the other hand, the unsulfated chondroitin, which can be obtained via biotechnological processes, demonstrated promising anti-inflammatory properties in vitro, in chondrocytes isolated from osteoarthritic patients. Therefore, the aim of this study was to explore the potential of chondroitin, with respect to the better-known CS, in an in vivo mouse model of knee osteoarthritis. Results indicate that the treatment with biotechnological chondroitin (BC), similarly to CS, significantly reduced the severity of mechanical allodynia in an MIA-induced osteoarthritic mouse model. Decreased cartilage damage and a reduction of inflammation- and pain-related biochemical markers were also observed. Overall, our data support a beneficial activity of biotechnological unsulfated chondroitin in the osteoarthritis model tested, thus suggesting BC as a potential functional ingredient in pharmaceuticals and nutraceuticals with the advantage of avoiding animal tissue extraction.

Fatty Acid Fingerprints and Hyaluronic Acid in Extracellular Vesicles from Proliferating Human Fibroblast-like Synoviocytes

Extracellular vesicles (EVs) function as conveyors of fatty acids (FAs) and other bioactive lipids and can modulate the gene expression and behavior of target cells. EV lipid composition influences the fluidity and stability of EV membranes and reflects the availability of lipid mediator precursors. Fibroblast-like synoviocytes (FLSs) secrete EVs that transport hyaluronic acid (HA). FLSs play a central role in inflammation, pannus formation, and cartilage degradation in joint diseases, and EVs have recently emerged as potential mediators of these effects. The aim of the present study was to follow temporal changes in HA and EV secretion by normal FLSs, and to characterize the FA profiles of FLSs and EVs during proliferation. The methods used included nanoparticle tracking analysis, confocal laser scanning microscopy, sandwich-type enzyme-linked sorbent assay, quantitative PCR, and gas chromatography. The expression of hyaluronan synthases 1-3 in FLSs and HA concentrations in conditioned media decreased during cell proliferation. This was associated with elevated proportions of 20:4n-6 and total n-6 polyunsaturated FAs (PUFAs) in high-density cells, reductions in n-3/n-6 PUFA ratios, and up-regulation of cluster of differentiation 44, tumor necrosis factor α, peroxisome proliferator-activated receptor (PPAR)-α, and PPAR-γ. Compared to the parent FLSs, 16:0, 18:0, and 18:1n-9 were enriched in the EV fraction. EV counts decreased during cell growth, and 18:2n-6 in EVs correlated with the cell count. To conclude, FLS proliferation was featured by increased 20:4n-6 proportions and reduced n-3/n-6 PUFA ratios, and FAs with a low degree of unsaturation were selectively transferred from FLSs into EVs. These FA modifications have the potential to affect membrane fluidity, biosynthesis of lipid mediators, and inflammatory processes in joints, and could eventually provide tools for translational studies to counteract cartilage degradation in inflammatory joint diseases.

Densification: Hyaluronan Aggregation in Different Human Organs

Hyaluronan (HA) has complex biological roles that have catalyzed clinical interest in several fields of medicine. In this narrative review, we provide an overview of HA aggregation, also called densification, in human organs. The literature suggests that HA aggregation can occur in the liver, eye, lung, kidney, blood vessel, muscle, fascia, skin, pancreatic cancer and malignant melanoma. In all these organs, aggregation of HA leads to an increase in extracellular matrix viscosity, causing stiffness and organ dysfunction. Fibrosis, in some of these organs, may also occur as a direct consequence of densification in the long term. Specific imaging evaluation, such dynamic ultrasonography, elasto-sonography, elasto-MRI and T1ρ MRI can permit early diagnosis to enable the clinician to organize the treatment plan and avoid further progression of the pathology and dysfunction.

Anti-inflammatory and Anti-osteoporotic Potential of Lactobacillus plantarum A41 and L. fermentum SRK414 as Probiotics

This study involves an investigation on the probiotic properties of lactic acid bacteria and their potential applications in an in vitro model of lipopolysaccharide (LPS)-stimulated inflammation and dexamethasone-induced osteoporosis. Nine strains were pre-screened from 485 lactic acid bacteria based on their survival at a low pH and in a solution containing bile salts. All candidates were capable of surviving in an environment with low pH and with bile salts and could successfully colonize the intestine. Furthermore, their functional properties, such as anti-oxidation and anti-inflammation, were evaluated. Of the nine probiotic candidates, Lactobacillus plantarum A41 and L. fermentum SRK414 exhibited the highest anti-oxidative capacity. Moreover, only L. plantarum A41 and L. fermentum SRK414 could increase gut barrier function by upregulating the mRNA expression of tight junction proteins and inhibit the expression of inflammatory mediators induced by LPS-stimulated inflammation. Interestingly, these two strains were also capable of regulating several bone metabolism-related markers playing a role in bone homeostasis and osteoblast differentiation. In brief, L. plantarum A41 and L. fermentum SRK414 exhibited high probiotic potential and potentially impact immune-related bone health by modulating pro-inflammatory cytokines and bone metabolism-related markers.

Nanoparticle-Cartilage Interaction: Pathology-Based Intra-articular Drug Delivery for Osteoarthritis Therapy

Osteoarthritis is the most prevalent chronic and debilitating joint disease, resulting in huge medical and socioeconomic burdens. Intra-articular administration of agents is clinically used for pain management. However, the effectiveness is inapparent caused by the rapid clearance of agents. To overcome this issue, nanoparticles as delivery systems hold considerable promise for local control of the pharmacokinetics of therapeutic agents. Given the therapeutic programs are inseparable from pathological progress of osteoarthritis, an ideal delivery system should allow the release of therapeutic agents upon specific features of disorders. In this review, we firstly introduce the pathological features of osteoarthritis and the design concept for accurate localization within cartilage for sustained drug release. Then, we review the interactions of nanoparticles with cartilage microenvironment and the rational design. Furthermore, we highlight advances in the therapeutic schemes according to the pathology signals. Finally, armed with an updated understanding of the pathological mechanisms, we place an emphasis on the development of "smart" bioresponsive and multiple modality nanoparticles on the near horizon to interact with the pathological signals. We anticipate that the exploration of nanoparticles by balancing the efficacy, safety, and complexity will lay down a solid foundation tangible for clinical translation.

Chondroitin Sulfate in USA Dietary Supplements in Comparison to Pharma Grade Products: Analytical Fingerprint and Potential Anti-Inflammatory Effect on Human Osteoartritic Chondrocytes and Synoviocytes

The biological activity of chondroitin sulfate (CS) and glucosamine (GlcN) food supplements (FS), sold in USA against osteoarthritis, might depend on the effective CS and GlcN contents and on the CS structural characteristics. In this paper three USA FS were compared to two pharmaceutical products (Ph). Analyses performed by HPAE-PAD, by HPCE and by SEC-TDA revealed that the CS and GlcN titers were up to −68.8% lower than the contents declared on the labels and that CS of mixed animal origin and variable molecular weights was present together with undesired keratan sulfate. Simulated gastric and intestinal digestions were performed in vitro to evaluate the real CS amount that may reach the gut as biopolymer. Chondrocytes and synoviocytes primary cells derived from human pathological joints were used to assess: cell viability, modulation of the NF-κB, quantification of cartilage oligomeric matrix protein (COMP-2), hyaluronate synthase enzyme (HAS-1), pentraxin (PTX-3) and the secreted IL-6 and IL-8 to assess inflammation. Of the three FS tested only one (US FS1) enhanced chondrocytes viability, while all of them supported synoviocytes growth. Although US FS1 proved to be less effective than Ph as it reduced NF-kB, it could not down-regulate COMP-2; HAS-1 was up-regulated but with a lower efficacy. Inflammatory cytokines were markedly reduced by Ph while a slight decrease was only found for US-FS1.

Clinical effectiveness and safety of intra-articular injection of HYALGO in the management of knee osteoarthritis symptoms: A multicenter prospective study

BACKGROUND

The reduced concentration of hyaluronic acid in the synovial fluid, leading to impairment of joint function and painful symptomatology during knee osteoarthritis (OA), can be restored by using injectable formulations of hyaluronic acid (HA) and chondroitin sulfate (CS), variable for relative composition, HA/CS molecular modifications, and injection protocols. The present study aims to assess the safety and performance of the intra-articular (IA) viscosupplementing agent HYALGO, a formulation combining 40 mg/mL HA (>1700 kDa) and 40 mg/mL CS, in the treatment of patients suffering from knee OA.

METHODS

74 patients affected by knee lesions classified as grade II and III according to Kellgren and Lawrence classification were prospectively recruited and treated with three HYALGO injections (2 mL) given one week apart. Visual analogue scale (VAS) pain changes were monitored at each injection and over-time at 6, 14, and 26 weeks of follow-up. Secondary endpoints were: Western Ontario McMaster University Osteoarthritis index (WOMAC), Patient's Global Assessment (PGA) score, Clinical Observer Global Assessment (COGA) score, Outcome Measures in Rheumatology Committee (OMERACT) and Osteoarthritis Research Society International (OARSI) responders rates. Patients were also assessed for changes in their ultrasound joint scores according to the criteria of the OMERACT US Task Force Group.

RESULTS

Pain reduction was statistically significant starting from the first IA injection. Mean pain reduction from baseline to week 26 was -90.6%. At 26 weeks, WOMAC Pain was reduced by -62.7%, WOMAC Stiffness by -47.2%, WOMAC Physical Function by -54.1%; Total WOMAC by -53.8%. The VAS PGA change from baseline was -48.0 [mm] and VAS COGA -41.0 [mm]. Responders at week 26 were 78.4%. Ultrasound parameters (joint effusion, synovial thickness, and popliteal cysts) improved or remained stable from baseline to week 6.

CONCLUSIONS

Three injections of HYALGO were safe and effective to manage symptomatic knee OA, with a beneficial effect that increased progressively over time, peaking 6 months after injection.

Functions of, and replenishment strategies for, chondroitin sulfate in the human body

Chondroitin sulfate (CS) belongs to a class of molecules called glycosaminoglycans (GAGs). These are long, linear chains of polysaccharides comprising alternating amino sugars and hexuronic acid. Similar to other GAGs, CS is important in a multitude of biological activities. Alteration of CS levels has been implicated in several pathological conditions, including osteoarthritis (OA) and other inflammatory diseases, as well as physiological conditions, such as aging. Therefore, devising replenishment strategies for this molecule is an important area of research. In this review, we discuss the nature of CS, its function in different organs, and its implications in health and disease. We also describe different methods for the exogenous administration of CS.

Re-appraising the potential of naringin for natural, novel orthopedic biotherapies

Naringin is a naturally occurring flavonoid found in plants of the Citrus genus that has historically been used in traditional Chinese medical regimens for the treatment of osteoporosis. Naringin modulates signaling through numerous molecular pathways critical to musculoskeletal development, cellular differentiation, and inflammation. Administration of naringin increases in vitro expression of bone morphogenetic proteins (BMPs) and activation of the Wnt/β-catenin and extracellular signal-related kinase (Erk) pathways, thereby promoting osteoblastic proliferation and differentiation from stem cell precursors for bone formation. Naringin also inhibits osteoclastogenesis by both modifying RANK/RANKL interactions and inducing apoptosis in osteoclasts in vitro. In addition, naringin acts on the estrogen receptor in bone to mimic the native bone-preserving effects of estrogen, with few systemic side effects on other estrogen-sensitive tissues. The efficacy of naringin therapy in reducing the osteolysis characteristic of common musculoskeletal pathologies such as osteoporosis, degenerative joint disease, and osteomyelitis, as well as inflammatory conditions affecting bone such as diabetes mellitus, has been extensively demonstrated in vitro and in animal models. Naringin thus represents a naturally abundant, cost-efficient agent whose potential for use in novel musculoskeletal biotherapies warrants re-visiting and further exploration through human studies. Here, we review the cellular mechanisms of action that have been elucidated regarding the action of naringin on bone resident cells and the bone microenvironment, in vivo evidence of naringin’s osteostimulative and chondroprotective properties in the setting of osteolytic bone disease, and current limitations in the development of naringin-containing translational therapies for common musculoskeletal conditions.

Regulation of gene expression by MF63, a selective inhibitor of microsomal PGE synthase 1 (mPGES1) in human osteoarthritic chondrocytes

Background and Purpose

mPGES1 catalyses the production of PGE₂, the most abundant prostanoid related to inflammation and pain in arthritis. mPGES1 is suggested to be a safer and more selective drug target in inflammatory conditions compared to the COX enzymes inhibited by NSAIDs. In the present study, we investigated the effects of the selective mPGES1 inhibitor MF63 on gene expression in primary human chondrocytes from patients with osteoarthritis (OA).

Experimental Approach

Chondrocytes were isolated from articular cartilage obtained from osteoarthritis patients undergoing knee replacement surgery. The effects of MF63 were studied in the primary chondrocytes with RNA‐sequencing based genome‐wide expression analysis. The main results were confirmed with qRT‐PCR and compared with the effects of the NSAID ibuprofen. Functional analysis was performed with the GO database and interactions between the genes were studied with STRING.

Key Results

MF63 enhanced the expression of multiple metallothionein 1 (MT1) isoforms as well as endogenous antagonists of IL‐1 and IL‐36. The expression of IL‐6, by contrast, was down‐regulated. These genes were also essential in functional and interaction network analyses. The effects of MF63 were consistent in qRT‐PCR analysis, whereas the effects of ibuprofen overlapped only partly with MF63. There were no evident findings of catabolic effects by MF63.

Conclusion and Implications

Metallothionein 1 has been suggested to have anti‐inflammatory and protective effects in cartilage. Up‐regulation of the antagonists of IL‐1 superfamily and down‐regulation of the pro‐inflammatory cytokine IL‐6 also support novel anti‐inflammatory and possibly disease‐modifying effects of mPGES1 inhibitors in arthritis.

[The efficacy and safety of intra-articular application of a combination of sodium hyaluronate and chondroitin sulfate for osteoarthritis of the knee: a multicenter prospective study]

in 3 mL on patients with knee osteoarthritis (OA) in a multicenter prospective study.

MATERIALS AND METHODS

79 outpatients (predominantly females 81.0%) from 5 RF constituent territories with primary tibiofemoral KellgrenLawrence score grade II or III knee OA, 40 mm pain intensity during walking on visual analogue scale (VAS), requiring NSAIDs intake (for at least 30 days during 3 months prior to enrollment) were included into the study after signing the informed consent form. Mean age was 60.38.7 years, mean BMI 29.24.7 kg/m2, disease duration 6 (310) years. Grade II OA was documented in 68.4% of patients, Grade III in 31.6%. The study lasted for 6 months. Efficacy and safety evaluations were made based on VAS pain assessment, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) [WOMAC pain (0500), WOMAC function (01700), WOMAC stiffness (0200)], VAS patients health status, EQ-5D-based assessment of patients quality of life, global physicians and patients efficacy assessment, and daily NSAIDs requirements.

RESULTS

Obtained results demonstrate statistically significant VAS pain reduction during walking already in 1 week after intra-articular injection of the combination [respectively, 62 (5572) and 41 (3251) mm, р0.0001]. Moreover, pain continued to subside during all 3 months of follow up [in 1 month 28 (2042), in 3 month 22 (1437) mm]. A significant pan reduction achieved at Mo 3 persisted until Mo 6 20 (1442) mm, without documented pain increase. Similar trends were observed with total WOMAC score [1125 (8991540) at baseline, and 552 (309837) mm by the end of the study, p0.0001], and all WOMAC sub-scores [268 (189312) baseline WOMAC pain, 91 (48171) mm by the end of the study p0.0001; stiffness 101 (59130) and 40 (2061) mm, p0.0001; function 802 (6471095) and 402 (191638) mm, p0.0001, respectively]. Median time to the onset of therapeutic effect was 7 (518) days. Statistically significant improvement of patients quality of life by EQ-5D and general health status was observed during all follow up period [respectively, 0.52 (-0.020.59) and 0.69 (0.590.80), р0.0001; 48 (3060) and 72 (6080) mm, р0.0001]. One injection of the drug resulted in dose reduction or discontinuation of NSAIDs therapy: at baseline 76 patients (96.2%) were taking NSAIDs, in one week 31 (39.2%) patients discontinued NSAIDs, in 1 month 72.2%, in 3 months 73.4%, and by the end of the study at Mo 6 54.4% were not taking NSAIDs. These data were consistent with physicians and patients global assessment of the efficacy of treatment, who stated significant improvement and improvement in the majority of cases, with only few no effect or worsening cases documented in analyzed population. Adverse events, such as worsening of pain and/or swelling of the joint, were documented in 8 patients (10.1%); they resolved spontaneously or following NSAIDs intake.

CONCLUSION

These results suggest that intra-articular injections of hyaluronic acid plus chondroitin sulfate in patients with knee OA are efficient and safe. A single injection of the drug resulted in statistically significant reduction of pain and stiffness, reduction in NSAIDs intake, as well as improvement in patients quality of life and function.

Intra-Articular Hyaluronic Acid and Chondroitin Sulfate: Pharmacokinetic Investigation in Osteoarthritic Rat Models

Background

Viscosupplementation of synovial fluid with intra-articular (IA) injections of hyaluronic acid (HA) is widely used for symptomatic treatment of osteoarthritis (OA). Herein we present HCS, a new combination of chemicals, associating HA and chondroitin sulfate (CS), both members of the glycosaminoglycan (GAGs) family, which are major components of the joint. HA provides viscosity to the synovial fluid and CS provides elasticity to the cartilage. Reduced levels of HA and CS are observed in OA joints and are associated with progressive cartilage damage and loss.

Objective

The objective of the study was to evaluate the pharmacokinetic (PK) properties of both HA and CS after IA administration in a validated OA animal model.

Methods

Motion impairment measurements and histological examinations were used to validate the ability of an IA injection of mono-iodoacetate (MIA) in the knee of rats to induce OA symptoms. Then, the PK properties of HA and CS after IA administration were characterized and each active ingredient was independently profiled: HA was labeled with tritium (3H-HA) and CS was labeled with carbon 14. (14C-CS) The final radio-labeled solution reproduced the cold HCS formulation.

Results

Four male Sprague-Dawley rats received a 1 mg MIA injection on day 1, then motor impairment was monitored from day 4 to day 18. Chondrocyte necrosis, loss of GAGs and other cartilage damage were observed. Twelve other rats received a MIA IA injection on day 1 then a radio-labeled HCS IA injection (50 µL) on day 8. Plasma and knee cartilage were collected postadministration and the terminal half-life was similar in both matrices (about 5 days), for both 3H-HA and 14C-CS.

Conclusions

Despite differences in their molecular size, HA and CS showed PK behavior similarly characterized by prolonged residence inside the joint and slow release in plasma, favoring long-term beneficial effects. (Curr Ther Res Clin Exp. 2020; 92:XXX-XXX).

Effect of diclofenac etalhyaluronate (SI-613) on the production of high molecular weight sodium hyaluronate in human synoviocytes

BACKGROUND

We have reported that a single intra-articular injection of diclofenac etalhyaluronate (SI-613) exerted a potent and long-lasting analgesic effect in experimental arthritis models. In the present study, we investigated the effect of SI-613 on the production of high molecular weight hyaluronic acid (HMW-HA) in synoviocytes from osteoarthritis (OA) patients and compared its efficacy with that of hyaluronic acid (HA).

METHODS

We compared the effect of SI-613, HA, and diclofenac sodium (DF-Na) on high molecular weight HA production by human synoviocytes.

RESULTS

SI-613 and exogenous HA induced the production of high molecular weight HA in synoviocytes from OA patients, whereas DF-Na had no effect. The molecular weight of newly produced HA was about 1000 kDa in the HA-treated synoviocytes and much higher than 2400 kDa in the SI-613-treated cells. The effect of the mixture of HA and DF-Na was similar to that of HA alone in that the molecular weight of newly produced HA was around 1000 kDa. SI-613 significantly suppressed hyaluronidase 2 (HYAL2) mRNA expression and significantly enhanced hyaluronan synthase 2 (HAS2) mRNA expression. HA had no effect on the expression levels of HYAL and HAS.

CONCLUSION

The present results clearly demonstrate that SI-613 induces the production of high molecular weight HA in synoviocytes from OA patients, suggesting the long-lasting analgesic and disease modifying effect of SI-613 for OA. Taken together with the anti-inflammatory and analgesic effects we recently reported for the intra-articular administration of SI-613 to experimental animal models, SI-613 holds great promise for the treatment of knee osteoarthritis.

Cultures of a human synovial cell line to evaluate platelet-rich plasma and hyaluronic acid effects

Synovial inflammation plays an important role in osteoarthritis (OA) pathogenesis. Different biological compounds have been tested mainly on chondrocytes, to treat early stages of OA. However, because OA has been recently defined as "an organ" pathology, investigation on synoviocytes is also needed. Therefore, the aim of the present study was to validate a human fibroblast-like synoviocytes cell line (K4IM) to test the effects of platelet-rich plasma (PRP) and hyaluronan (HA) on anabolic and catabolic gene expression and on HA secretion from cell cultures. In order to determine the effect of PRP and HA, K4IM cells were maintained in culture with or without TNF-α stimulation. In the presence of PRP, unstimulated K4IM cells presented the same expression of IL1B, IL6, CXCL8, VEGF, TIMP1, and hyaluronic synthase isoform HAS3 as primary human synoviocytes, while HA addition did not change their expression pattern, which was similar to control cells. Stimulated cells expressed significantly higher values of IL1B, CXCL8, and VEGF compared with unstimulated ones. PRP did not show any modification, except for VEGF, while HA addition modulated IL1B expression. PRP did not modulate HA release of both stimulated and unstimulated cells. Our study showed the possibility to use K4IM synoviocytes as an in vitro model to test biological compounds useful for the treatment of early OA. Primary cells reflect the phenotype of cells in vivo, but limited recovery from biopsies and restricted lifespan makes experimental manipulation challenging. Therefore, despite cell lines present some limitations, they could be used as an alternative for preliminary experiments.

Isolation, Purification and Structural Characterestics of Chondroitin Sulfate from Smooth hound Cartilage: In vitro Anticoagulant and Antiproliferative Properties

Chondroitin sulfate was extracted from the cartilage of smooth hound (CSSH) and then purified by anion exchange chromatography. The structual characteristic of CSSH was evaluated by acetate cellulose electrophoresis, FTIR, ¹³C NMR and SAX-HPLC. Molecular weight of CSSH was average 68.78 KDa. Disaccharide analysis indicated that CSSH was predominately composed of monosulfated disaccharides in position 6 and 4 of the N-acetylgalactosamine (45.34% and 32.49%, respectively). CSSH was tested for in vitro anticoagulant activity using the three classical coagulation assays (activated partial thromboplastin time (aPTT), prothrombine time (TT) and thrombin time (PT) tests). The finding showed that CSSH prolonged significatively (p < 0.05), aPTT, TT and PT about 1.4, 3.44 and 1.21 fold, respectively, greater than that of the negative control at a concentration of 100 μg/ml. The CSSH caused a significant antiproliferative activity against HCT116 cell, which was 79% of cell proliferation inhibition at the concentration of 1000 μg/ml. Further, CSSH presented no toxicity against the normal cells and no hemolysis towards bovine erythrocytes for all concentrations tested. CSSH demonstrated hopeful antiproliferative and anticoagulant potential, which may be used as a novel and effective drug.

Human hyaluronic acid synthase-1 promotes malignant transformation via epithelial-to-mesenchymal transition, micronucleation and centrosome abnormalities

Background

Human hyaluronic acid (HA) molecules are synthesized by three membrane spanning Hyaluronic Acid Synthases (HAS1, HAS2 and HAS3). Of the three, HAS1 is found to be localized more into the cytoplasmic space where it synthesizes intracellular HA. HA is a ubiquitous glycosaminoglycan, mainly present in the extracellular matrix (ECM) and on the cell surface, but are also detected intracellularly. Accumulation of HA in cancer cells, the cancer-surrounding stroma, and ECM is generally considered an independent prognostic factors for patients. Higher HA production also correlates with higher tumor grade and more genetic heterogeneity in multiple cancer types which is known to contribute to drug resistance and results in treatment failure. Tumor heterogeneity and intra-tumor clonal diversity are major challenges for diagnosis and treatment. Identification of the driver pathway(s) that initiate genomic instability, tumor heterogeneity and subsequent phenotypic/clinical manifestations, are fundamental for the diagnosis and treatment of cancer. Thus far, no evidence was shown to correlate intracellular HA status (produced by HAS1) and the generation of genetic diversity in tumors.

Methods

We tested different cell lines engineered to induce HAS1 expression. We measured the epithelial traits, centrosomal abnormalities, micronucleation and polynucleation of those HAS1-expressing cells. We performed real-time PCR, 3D cell culture assay, confocal microscopy, immunoblots and HA-capture methods.

Results

Our results demonstrate that overexpression of HAS1 induces loss of epithelial traits, increases centrosomal abnormalities, micronucleation and polynucleation, which together indicate manifestation of malignant transformation, intratumoral genetic heterogeneity, and possibly create suitable niche for cancer stem cells generation.

Conclusions

The intracellular HA produced by HAS1 can aggravate genomic instability and intratumor heterogeneity, pointing to a fundamental role of intracellular HA in cancer initiation and progression.

Electronic supplementary material

The online version of this article (10.1186/s12964-017-0204-z) contains supplementary material, which is available to authorized users.

The comparison of the effects of a novel hydrogel compound and traditional hyaluronate following micro-fracture procedure in a rat full-thickness chondral defect model

PURPOSE

The aim of this experimental study was to investigate the impact of HA-CS-NAG compound (hyaluronate, sodium chondroitin sulfate, N-acetyl-d-glucosamine) on the quality of repair tissue after micro-fracture and to compare it with HA (hyaluronat), in a rat full-thickness chondral defect model.

METHODS

Full-thickness chondral defects were created in a non-weight bearing area by using a handle 2.7-mm drill bit, in the right knees of 33 Sprague-Dawley rats. Each specimen then underwent micro-fracture using a needle. Two weeks after surgery, 3 groups were randomly formed among the rats (n = 33). In Group 1, 0.2 mL of sterile saline solution (0.9%) was injected. In Group 2, 0.2 mL HA with a mean molecular weight of 1.2 Mda was injected. In Group 3, 0.2 mL of HA-CS-NAG compound (hyaluronate, sodium chondroitin sulfate, N-acetyl-d-glucosamine) was injected. The injections were applied on the 14th, the 21st and the 28th postoperative days. All rats were sacrificed on the 42nd postoperative day. Histological analysis of the repair tissue was performed for each specimen by two blinded observers using Wakitani scoring system.

RESULTS

There was significantly improved repair tissue in both Group 3 and Group 2 when compared with Group 1. Group 3 showed statistically significant improvement in terms of 'cell morphology' and 'integration of donor with host' when compared to Group 2 (p < 0.001).

CONCLUSION

Intra-articular injection of HA-CS-NAG compound after micro-fracture results in significantly improved repair tissue in rats' chondral defects when compared to HA regarding the donor integration and cell morphology.

Monosodium urate crystals induce oxidative stress in human synoviocytes

Background

Gout is the most common inflammatory arthropathy of metabolic origin and it is characterized by intense inflammation, the underlying mechanisms of which are unknown. The aim of this study was to evaluate the oxidative stress in human fibroblast-like synoviocytes (FLS) exposed to monosodium urate (MSU) crystals, which trigger an inflammatory process.

Methods

Human FLS isolated from synovial tissue explants were stimulated with MSU crystals (75 μg/mL) for 24 h. Cellular viability was evaluated by crystal violet staining, apoptosis was assessed using Annexin V, and the cellular content of reactive oxygen species (ROS) and nitrogen species (RNS) (O₂^-, H₂O₂, NO) was assessed with image-based cytometry and fluorometric methods. In order to determine protein oxidation levels, protein carbonyls were detected through oxyblot analysis, and cell ultrastructural changes were assessed by transmission electron microscopy.

Results

The viability of FLS exposed to MSU crystals decreased by 30 % (P < 0.05), while apoptosis increased by 42 % (P = 0.01). FLS stimulated with MSU crystals exhibited a 2.1-fold increase in H₂O₂ content and a 1.5-fold increase in O₂^- and NO levels. Oxyblots revealed that the spots obtained from FLS protein lysates exposed to MSU crystals exhibited protein carbonyl immunoreactivity, which reflects the presence of oxidatively modified proteins. Concomitantly, MSU crystals triggered the induction of changes in the morphostructure of FLS, such as the thickening and discontinuity of the endoplasmic reticulum, and the formation of vacuoles and misfolded glycoproteins.

Conclusions

Our results prove that MSU crystals induce the release of ROS and RNS in FLS, subsequently oxidizing proteins and altering the cellular oxidative state of the endoplasmic reticulum, which results in FLS apoptosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1012-3) contains supplementary material, which is available to authorized users.

Biotechnological Chondroitin a Novel Glycosamminoglycan With Remarkable Biological Function on Human Primary Chondrocytes

Cartilage tissue engineering, with in vitro expansion of autologus chondrocytes, is a promising technique for tissue regeneration and is a new potential strategy to prevent and/or treat cartilage damage (e.g., osteoarthritis). The aim of this study was (i) to investigate and compare the effects of new biotechnological chondroitin (BC) and a commercial extractive chondroitin sulfate (CS) on human chondrocytes in vitro culture; (ii) to evaluate the anti‐inflammatory effects of the innovative BC compared to extractive CS. A chondrogenic cell population was isolated from human nasoseptal cartilage and in vitro cultures were studied through time‐lapse video microscopy (TLVM), immunohistochemical staining and cytometry. In order to investigate the effect of BC and CS on phenotype maintainance, chondrogenic gene expression of aggrecan (AGN), of the transcriptor factor SOX9, of the types I and II collagen (COL1A1 and COL1A2), were quantified through transcriptional and protein evaluation at increasing cultivation time and passages. In addition to resemble the osteoarthritis‐like in vitro model, chondrocytes were treated with IL‐1β and the anti‐inflammatory activity of BC and CS was assessed using cytokines quantification by multiplex array. BC significantly enhances cell proliferation also preserving chondrocyte phenotype increasing type II collagen expression up to 10 days of treatment and reduces inflammatory response in IL‐1β treated chondrocytes respect to CS treated cells. Our results, taken together, suggest that this new BC is of foremost importance in translational medicine because it can be applied in novel scaffolds and pharmaceutical preparations aiming at cartilage pathology treatments such as the osteoarthritis. J. Cell. Biochem. 117: 2158–2169, 2016. © 2016 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.

PP2B and ERK1/2 regulate hyaluronan synthesis of HT168 and WM35 human melanoma cell lines

Hyaluronan (HA) is the major glycosaminoglycan component of the extracellular matrix in either normal or malignant tissues and it may affect proliferation, motility and differentiation of various cell types. Three isoforms of plasma membrane-bound hyaluronan synthases (HAS 1, 2 and 3) secrete and simultaneously bind pericellular HA. HAS enzymes are subjects of post-translational protein phosphorylation which is believed to regulate their enzymatic activity. In this study, we investigated the HA homeostasis of normal human epidermal melanocytes, HT168 and WM35 human melanoma cell lines and melanoma metastases. HAS2 and HAS3 were detected in all the samples, while the expression of HAS1 was not detectable in any case. Malignant tissue samples and melanoma cell lines contained extra- and intracellular HA abundantly but not normal melanocytes. Applying HA as a chemoattractant facilitated the migration of melanoma cells in Boyden chamber. The amount of HA was reduced upon the inhibition of calcineurin with cyclosporine A (CsA), while the inhibition of ERK1/2 with PD098059 elevated it in both cell lines. The signals of Ser/Thr phosphoproteins at 57 kD were stronger after CsA treatment, while a markedly weaker signal was detected upon inhibition of the MAPK pathway. Our results suggest opposing effects of the two investigated enzymes on the HA homeostasis of melanoma cells. We propose that the dephosphorylation of HAS enzymes targeted by PP2B augments HA production, while their phosphorylation by the activity of MAPK pathway reduces HA synthesis. As the expression of the HA receptor RHAMM was also significantly enhanced by PD098059, the MAPK pathway exerted a complex attenuating effect on HA signalling in the investigated melanoma cells. This observation suggests that the application of MAPK-ERK pathway inhibitors requires a careful therapeutic design in melanoma treatment.

Hyaluronan synthase 1: a mysterious enzyme with unexpected functions

Hyaluronan synthase 1 (HAS1) is one of three isoenzymes responsible for cellular hyaluronan synthesis. Interest in HAS1 has been limited because its role in hyaluronan production seems to be insignificant compared to the two other isoenzymes, HAS2 and HAS3, which have higher enzymatic activity. Furthermore, in most cell types studied so far, the expression of its gene is low and the enzyme requires high concentrations of sugar precursors for hyaluronan synthesis, even when overexpressed in cell cultures. Both expression and activity of HAS1 are induced by pro-inflammatory factors like interleukins and cytokines, suggesting its involvement in inflammatory conditions. Has1 is upregulated in states associated with inflammation, like atherosclerosis, osteoarthritis, and infectious lung disease. In addition, both full length and splice variants of HAS1 are expressed in malignancies like bladder and prostate cancers, multiple myeloma, and malignant mesothelioma. Interestingly, immunostainings of tissue sections have demonstrated the role of HAS1 as a poor predictor in breast cancer, and is correlated with high relapse rate and short overall survival. Utilization of fluorescently tagged proteins has revealed the intracellular distribution pattern of HAS1, distinct from other isoenzymes. In all cell types studied so far, a high proportion of HAS1 is accumulated intracellularly, with a faint signal detected on the plasma membrane and its protrusions. Furthermore, the pericellular hyaluronan coat produced by HAS1 is usually thin without induction by inflammatory agents or glycemic stress and depends on CD44–HA interactions. These specific interactions regulate the organization of hyaluronan into a leukocyte recruiting matrix during inflammatory responses. Despite the apparently minor enzymatic activity of HAS1 under normal conditions, it may be an important factor under conditions associated with glycemic stress like metabolic syndrome, inflammation, and cancer.

Systemic biochemical markers of joint metabolism and inflammation in relation to radiographic parameters and pain of the knee: data from CHECK, a cohort of early-osteoarthritis subjects

OBJECTIVE

To investigate associations of biochemical markers of joint metabolism and inflammation with minimum joint space width (JSW) and osteophyte area (OP area) of knees showing no or doubtful radiographic osteoarthritis (OA) and to investigate whether these differed between painful and non-painful knees.

DESIGN

Serum (s-) and urinary (u-) levels of the cartilage markers uCTX-II, sCOMP, sPIIANP, and sCS846, bone markers uCTX-I, uNTX-I, sPINP, and sOC, synovial markers sPIIINP and sHA, and inflammation markers hsCRP and erythrocyte sedimentation rate (ESR) were assessed in subjects from CHECK (Cohort Hip and Cohort Knee) demonstrating Kellgren and Lawrence grade ≤1 OA on knee radiographs. Minimum JSW and OP area of these knees were quantified in detail using Knee Images Digital Analysis (KIDA).

RESULTS

uCTX-II levels showed negative associations with minimum JSW and positive associations with OP area. sCOMP and sHA levels showed positive associations with OP area, but not with minimum JSW. uCTX-I and uNTX-I levels showed negative associations with minimum JSW and OP area. Associations of biochemical marker levels with minimum JSW were similar between painful and non-painful knees, associations of uCTX-II, sCOMP, and sHA with OP area were only observed in painful knees.

CONCLUSIONS

In these subjects with no or doubtful radiographic knee OA, uCTX-II might not only reflect articular cartilage degradation but also endochondral ossification in osteophytes. Furthermore, sCOMP and sHA relate to osteophytes, maybe because synovitis drives osteophyte development. High bone turnover may aggravate articular cartilage loss. Metabolic activity in osteophytes and synovial tissue, but not in articular cartilage may be related to knee pain.

Effect of two different preparations of platelet-rich plasma on synoviocytes

PURPOSE

To analyse the modifications induced by two different platelet-rich plasma (PRP) preparations on osteoarthritis (OA) synoviocytes, by documenting changes in gene expression of factors involved in joint physiopathology.

METHODS

OA synoviocytes were cultured for 7 days in medium with different concentrations of either P-PRP (a pure platelet concentrate without leucocytes but with a limited number of platelets), L-PRP (a higher platelet concentrate containing leucocytes) or platelet-poor plasma (PPP). Gene expression of interleukin (IL)-1beta, IL-6, IL-8/CXCL8, tumour necrosis factor alpha, IL-10, IL-4, IL-13, metalloproteinase-13, tissue inhibitor of metalloproteinase (TIMP)-1, (TIMP)-3, (TIMP)-4, vascular endothelial growth factor, transforming growth factor beta1, fibroblast growth factor (FGF)-2, hepatocyte growth factor (HGF), hyaluronic acid (HA) synthases (HAS)-1, (HAS)-2, and (HAS)-3 was analysed by RT-PCR. HA production was determined in culture supernatants by ELISA.

RESULTS

IL-1β, IL-8 and FGF-2 were significantly induced by L-PRP compared to both P-PRP and PPP; HGF was down-modulated by L-PRP versus both P-PRP and PPP, and an inverse dose-response influence was shown for all preparations. Expression level of TIMP-4 was lower in the presence of L-PRP compared with P-PRP. HA production and HAS gene expression did not seem to be modulated by PRP.

CONCLUSIONS

L-PRP is able to sustain the up-regulation of proinflammatory factors, (IL-1beta, IL-8 and FGF-2), together with a down-modulation of HGF and TIMP-4 expression, two factors that have been recognized as anti-catabolic mediators in cartilage, thus supporting the need to further optimize the PRP preparations to be applied in clinical practice.

Angelica Sinensis polysaccharides stimulated UDP-sugar synthase genes through promoting gene expression of IGF-1 and IGF1R in chondrocytes: promoting anti-osteoarthritic activity

BACKGROUND

Osteoarthritis (OA) is a chronic joints disease characterized by progressive degeneration of articular cartilage due to the loss of cartilage matrix. Previously, we found, for the first time, that an acidic glycan from Angelica Sinensis Polysaccharides (APSs), namely the APS-3c, could protect rat cartilage from OA due to promoting glycosaminoglycan (GAG) synthesis in chondrocytes. In the present work, we tried to further the understanding of ASP-3c's anti-OA activity.

METHODOLOGY/PRINCIPAL FINDINGS

Human primary chondrocytes were treated with APS-3c or/and recombinant human interleukin 1β (IL-1β). It turned out that APS-3c promoted synthesis of UDP-xylose and GAG, as well as the gene expression of UDP-sugar synthases (USSs), insulin like growth factor 1 (IGF1) and IGF1 receptor (IGF1R), and attenuated the degenerative phenotypes, suppressed biosynthesis of UDP-sugars and GAG, and inhibited the gene expression of USSs, IGF1 and IGF1R induced by IL-1β. Then, we induced a rat OA model with papain, and found that APS-3c also stimulated GAG synthesis and gene expression of USSs, IGF1 and IGF1R in vivo. Additionally, recombinant human IGF1 and IGF1R inhibitor NP-AEW541 were applied to figure out the correlation between stimulated gene expression of USSs, IGF1 and IGF1R induced by APS-3c. It tuned out that the promoted GAG synthesis and USSs gene expression induced by APS-3c was mediated by the stimulated IGF1 and IGF1R gene expression, but not through directly activation of IGF1R signaling pathway.

CONCLUSIONS/SIGNIFICANCES

We demonstrated for the first time that APS-3c presented anti-OA activity through stimulating IGF-1 and IGF1R gene expression, but not directly activating the IGF1R signaling pathway, which consequently promoted UDP-sugars and GAG synthesis due to up-regulating gene expression of USSs. Our findings presented a better understanding of APS-3c's anti-OA activity and suggested that APS-3c could potentially be a novel therapeutic agent for OA.

Chondroitin sulphate extracted from antler cartilage using high hydrostatic pressure and enzymatic hydrolysis

Chondroitin sulphate (CS), a major glycosaminoglycan, is an essential component of the extracellular matrix in cartilaginous tissues. Wapiti velvet antlers are a rich source of these molecules. The purpose of the present study was to develop an effective isolation procedure of CS from fresh velvet antlers using a combination of high hydrostatic pressure (100 MPa) and enzymatic hydrolysis (papain). High CS extractability (95.1 ± 2.5%) of total uronic acid was obtained following incubation (4 h at 50 °C) with papain at pH 6.0 in 100 MPa compared to low extractability (19 ± 1.1%) in ambient pressure (0.1 MPa). Antler CS fractions were isolated by Sephacryl S-300 chromatography and identified by western blot using an anti-CS monoclonal antibody. The antler CS fraction did not aggregate with hyaluronic acid in CL-2B chromatography and possessed DPPH radical scavenging activity at 78.3 ± 1.5%. The results indicated that high hydrostatic pressure and enzymatic hydrolysis procedure may be a useful tool for the isolation of CS from antler cartilaginous tissues.

Does platelet-rich plasma freeze-thawing influence growth factor release and their effects on chondrocytes and synoviocytes?

PRP cryopreservation remains a controversial point. Our purpose was to investigate the effect of freezing/thawing on PRP molecule release, and its effects on the metabolism of chondrocytes and synoviocytes. PRP was prepared from 10 volunteers, and a half volume underwent one freezing/thawing cycle. IL-1β, HGF, PDGF AB/BB, TGF-β1, and VEGF were assayed 1 hour and 7 days after activation. Culture media of chondrocytes and synoviocytes were supplemented with fresh or frozen PRP, and, at 7 days, proliferation, gene expression, and secreted proteins levels were evaluated. Results showed that in the freeze-thawed PRP the immediate and delayed molecule releases were similar or slightly lower than those in fresh PRP. TGF-β1 and PDGF AB/BB concentrations were significantly reduced after freezing both at 1 hour and at 7 days, whereas HGF concentration was significantly lower in frozen PRP at 7 days. In fresh PRP IL-1β and HGF concentrations underwent a significant further increase after 7 days. Similar gene expression was found in chondrocytes cultured with both PRPs, whereas in synoviocytes HGF gene expression was higher in frozen PRP. PRP cryopreservation is a safe procedure, which sufficiently preserves PRP quality and its ability to induce proliferation and the production of ECM components in chondrocytes and synoviocytes.

Comparison of platelet-rich plasma formulations for cartilage healing: an in vitro study

BACKGROUND

Platelet-rich plasma (PRP) has been advocated as one treatment for cartilage tissue regeneration. To date, several different platelet-rich formulations have been available, but a deep knowledge of their composition and mechanism of action in a specific clinical use is needed. The aim of this study was to investigate the effect of various PRP formulations on human chondrocytes in vitro.

METHODS

Blood from ten human volunteers was used to prepare three formulations: (1) PRP with a relatively low concentration of platelets and very few leukocytes (P-PRP), (2) PRP with high concentrations of both platelets and leukocytes (L-PRP), and (3) platelet-poor plasma (PPP). Selected growth factors in the formulations were measured, and the in vitro effects of various concentrations were tested by exposing chondrocytes isolated from osteoarthritic cartilage of four different men and measuring cell proliferation, matrix production, and gene expression.

RESULTS

L-PRP contained the highest levels of growth factors and cytokines. All three formulations stimulated chondrocyte proliferation throughout the culture period evaluated; the only significant difference among the formulations was on day 7, when P-PRP induced greater cell growth compared with the other two formulations. P-PRP stimulated chondrocyte anabolism, as shown by the expression of type-II collagen and aggrecan, whereas L-PRP promoted catabolic pathways involving various cytokines. However, L-PRP induced greater expression of the hyaluronic acid synthase-2 gene and greater production of hyaluronan compared with P-PRP.

CONCLUSIONS

L-PRP and P-PRP induced distinct effects on human articular chondrocytes in vitro, possibly because of differences in the concentrations of platelets, leukocytes, growth factors, and other bioactive molecules. The identification of the optimal amounts and ratios of these blood components could ideally lead to a formulation more suitable for the treatment of cartilage lesions.

Knee osteoarthritis: hyaluronic acid, platelet-rich plasma or both in association?

INTRODUCTION

Bidirectional interactions between cells and fluidic surroundings regulate cellular functions and maintain tissue or organ architecture. Accordingly, the synovial fluid is the primary source of environmental signals and determines to a great extent the molecular interactions within the joint capsule, both in homeostasis and pathology.

AREAS COVERED

We provided an update on hyaluronic acid (HA) and platelet-rich plasma (PRP) concepts necessary to build the rationale for creating a combined treatment. The information is based on a PubMed search using the terms 'platelet-rich plasma', 'hyaluronic acid', 'knee pathology', 'knee osteoarthritis' (OA).

EXPERT OPINION

In OA, a deleterious fluidic microenvironment is established, with presence of HA fragments, catabolic enzymes and inflammatory molecules. The central concept underlying intra-articular injection is to modify deleterious fluidic microenvironments. PRP administration has shown pain remission and function improvement, but less than half of the patients showed clinically significant improvement. PRP exceeds HA, the comparator used in PRP clinical trials, albeit both HA and PRP alleviate symptoms in mild-to-moderate OA patients. Combining PRP and HA may benefit from their dissimilar biological mechanisms and help in controlling delivery and presentation of signaling molecules. Three armed randomized studies, using both HA and PRP as comparators, will provide information about the impact of this approach.

Hyaluronic acid secretion by synoviocytes alters under cyclic compressive load in contracted collagen gels

Knee osteoarthritis is a degenerative disease of diarthrodial joints. Biomechanical factors are considered as risk factors for the disease, the knee joint being normally subject to pressure. Some studies have examined the biomechanical environment of the knee joint in vitro. The aim of this study was to establish a culture model to mimic the knee joint environment. As a first step, synoviocytes induced contraction of three-dimensional collagen gels. Next, contracted collagen gels containing synoviocytes underwent cyclical compression ranging from 0 to 40 kPa at a frequency of 1.0 Hz for 1.5, 3, 6 and 12 h using the FX-4000C™ Flexercell(®) Compression Plus™ System. RNA in collagen gels was extracted immediately after compression and mRNA expression levels of HAS genes were analyzed by quantitative RT-PCR. Culture medium was collected 48 h after compression and analyzed by agarose gel electrophoresis and cellulose acetate electrophoresis. Synoviocytes in contracted collagen gels were stimulated by cyclic compressive load. Long-term compressive stimulation led to the production of higher molecular weight hyaluronic acid, whereas, short-term, compressive stimulation increased the total amount of hyaluronic acid. Furthermore, mRNA expression levels of both HAS-1 and HAS-2 were significantly higher than without compression. Taken together, using this gel culture system, synoviocytes synthesized higher molecular weight hyaluronic acid and produced large quantities of hyaluronic acid through up-regulation of HAS gene expression. Therefore, the contracted collagen gel model will be a useful in vitro three-dimensional model of the knee joint.

Importance of synovitis in osteoarthritis: evidence for the use of glycosaminoglycans against synovial inflammation

OBJECTIVES

After detailing the different aspects of synovial inflammation (i.e., cellular, biochemical, and vascular) and based on the current knowledge, the aim of this review was to collect the available in vitro and in vivo data regarding the potency of some glycosaminoglycan (GAG) compounds to target synovial inflammation, an important aspect of osteoarthritis.

METHODS

The first part of the review corresponds to a qualitative review of the inflammatory status of OA synovial membrane. The second part corresponds to a systematic review of the literature regarding the potential effects of some GAGs on the previously described phenomenon.

RESULTS

The synovial aspect of the inflammatory status of OA has been detailed. Chondroitin sulfate has demonstrated to control the three aspects of synovial membrane inflammation: cell infiltration and activity, biochemical mediators release, and angiogenesis. Glucosamine is also active on both cellular and molecular aspects of the inflammatory reaction. Hyaluronic acid seems to be anti-inflammatory in its native form, while products of degradation are reported to be pro-angiogenic.

CONCLUSION

Much evidence suggests that some of the studied GAG compounds could target different aspects of synovitis. Some of them could be considered in combination therapy since they exhibit complementary properties. Most of the studies have concentrated on articular cartilage and chondrocytes. In order to achieve a structure modification, one may now consider all joint tissues and investigate the drug potency on all of them. Potent treatment should trigger the most important features of OA: cartilage degradation, subchondral bone sclerosis, and all aspects of synovial inflammation.

Symptom and structure modification in osteoarthritis with pharmaceutical-grade chondroitin sulfate: what's the evidence?

OBJECTIVES

Osteoarthritis is a chronic disease characterized by irreversible damage to joint structures, including loss of articular cartilage, osteophyte formation, alterations in the subchondral bone and synovial inflammation. It has been shown that chondroitin sulfate interferes with the progression of structural changes in joint tissues and is used in the management of patients with osteoarthritis.

METHODS

This review summarizes data from relevant reports describing the mechanisms of action of chondroitin sulfate that may explain the beneficial effects of the drug and examines the evidence for clinical efficacy of oral chondroitin sulfate in osteoarthritis. Data included in the review were derived from a literature search in PubMed. Literature searches were performed in PubMed using the search terms 'chondroitin sulfate', 'pharmaceutical-grade', 'osteoarthritis', 'randomized clinical trials', 'humans'. The MEDLINE database was searched from January 1996 through August 2012 for all randomized controlled trials, meta-analyses, systematic reviews, and review articles of chondroitin sulfate in osteoarthritis.

RESULTS

Chondroitin sulfate exerts in vitro a beneficial effect on the metabolism of different cell lines: chondrocytes, synoviocytes and cells from subchondral bone, all involved in osteoarthritis. It increases type II collagen and proteoglycan synthesis in human articular chondrocytes and is able to reduce the production of some pro-inflammatory factors and proteases, to reduce the cellular death process, and improve the anabolic/catabolic balance of the extracellular cartilage matrix (ECM). Clinical trials have reported a beneficial effect of chondroitin sulfate on pain and function. The structure-modifying effects of chondroitin sulfate have been reported and analyzed in recent meta-analyses. The results in knee osteoarthritis demonstrate a small but significant reduction in the rate of decline in joint space width. Because chondroitin sulfate quality of several nutraceuticals has been found to be poor, it is recommended that pharmaceutical-grade chondroitin sulfate is used rather than food supplements in the treatment of OA. Chondroitin sulfate is recommended by several guidelines from international societies in the management of knee and hip OA. Furthermore, its safety profile is favorable when compared with many other therapies used in OA.

CONCLUSION

Chondroitin sulfate is an effective and safe treatment option for patients with osteoarthritis.

Interleukin-32-induced thymic stromal lymphopoietin plays a critical role in macrophage differentiation through the activation of caspase-1 in vitro

Introduction

Interleukin (IL)-32 is an inflammatory cytokine induced by Mycobacterium tuberculosis and Mycobacterium bovis in a variety of cell types and discovered in the synovial of patients with rheumatoid arthritis (RA). Thymic stromal lymphopoietin (TSLP) play several roles in the pathogenesis of RA. However, the role of IL-32 and TSLP in RA has not been elucidated.

Methods

We evaluated the specific mechanism of between IL-32 and TSLP in RA using human monocyte cell line, THP-1 cells.

Results

Here we documented for the first time that IL-32 highly increased TSLP production in THP-1 cells and human blood monocytes. TSLP expression was induced by IL-32 via activation of caspase-1 and nuclear factor-κB. TSLP produced by IL-32 increased differentiation of monocytes but depletion of TSLP prevented differentiation of monocytes into macrophage-like cells. Chondroprotective drugs such as chondroitin sulfate (CS) and the traditional Korean medicine, BaekJeol-Tang (BT) decrease production of TSLP and activation of caspase-1 and nuclear factor-κB. In addition, CS and BT inhibited IL-32-induced monocytes differentiation.

Conclusions

Taken together, IL-32 and TSLP are important cytokines involved in the development of RA. The effects of CS and BT were associated with the downregulation of TSLP and caspase-1 through negative regulation of IL-32 pathways in RA.

Chondroitin sulfate in the treatment of osteoarthritis: from in vitro studies to clinical recommendations

Chondroitin sulfate (CS) is recommended as a therapeutic intervention in the multimodal approach of osteoarthritis (OA) management. CS has been studied extensively to describe its pharmacology (pharmacokinetic, in vitro and in vivo effects) and its clinical efficacy. Various results have been reported depending on the system of evaluation (model, dosage and duration) and the source of CS (origin and quality). The purpose of this review was to gather most of the available information about CS and to discuss its potency in OA management.

Effect of a solution of hyaluronic acid-chondroitin sulfate-N-acetyl glucosamine on the repair response of cartilage to single-impact load damage

OBJECTIVE

To investigate effects of 1% hyaluronic acid-chondroitin sulfate-N-acetyl glucosamine (HCNAG) on the damage repair response in equine articular cartilage.

SAMPLE

Articular cartilage from 9 clinically normal adult horses.

PROCEDURES

Full-thickness cartilage disks were harvested from the third metacarpal bone. Cartilage was single-impact loaded (SIL) with 0.175 J at 0.7 m/s and cultured in DMEM plus 1 % (vol/vol) HCNAG or fibroblastic growth factor (FGF)-2 (50 ng/mL). Histologic and immunohistochemical techniques were used to identify tissue architecture and apoptotic cells and to immunolocalize type I and II collagen and proliferating nuclear cell antigen (PCNA).

RESULTS

Type II collagen immunoreactivity increased in SIL cartilage, compared with control samples. At days 14 and 28 (day 0 = initiation of culture), control samples had significantly fewer repair cells than did other treatment groups. In control samples and SIL + HCNAG, there was a significant decrease in apoptotic cell number, compared with results for SIL and SIL + FGF-2 samples. At days 14 and 28, there was a significant increase in chondrocytes stained positive for PCNA in the control samples.

CONCLUSIONS AND CLINICAL RELEVANCE

1% HCNAG significantly affected apoptotic and repair cell numbers in an SIL damage-repair technique in adult equine articular cartilage. However, HCNAG had no effect on the number of PCNA-positive chondrocytes or on type II collagen immunohistochemical results. The inclusion of 1% HCNAG in lavage solutions administered after arthroscopy may be beneficial to cartilage health by increasing the number of repair cells and decreasing the number of apoptotic cells.

Estrogen affects the glycosaminoglycan layer of the murine bladder

OBJECTIVES

Urinary tract infections (UTIs), commonly caused by uropathogenic Escherichia coli (UPEC), confer significant morbidity among postmenopausal women. Glycosaminoglycans (GAGs) comprise the first line of defense at the bladder's luminal surface. Our objective was to use a murine model of menopause to determine whether estrogen status affects the GAG layer in response to UPEC infection.

METHODS

Adult female mice underwent sham surgery (SHAM, n = 18) or oophorectomy (OVX, n = 66) to establish a murine model of menopause. A subset of oophorectomized mice underwent hormone therapy (HT, n = 33) with 17β-estradiol. Mice were inoculated with UPEC and killed at various time points; bladders were collected and GAG layer thickness was assessed in multiple bladder sections. Sixteen measurements were made per bladder. A repeated-measures 2-way analysis of variance was performed to determine the effect of time after infection and hormonal condition on GAG thickness. We also investigated the molecular underpinnings of GAG biosynthesis in response to alterations in estrogen status and infection.

RESULTS

We did not observe significant difference of GAG thickness among the 3 hormonal conditions; however, the time course of GAG thickness was significantly different (P < 0.05). The OVX mice demonstrated significantly greater thickness at 72 hours after infection (P = 0.0001), and this effect was shifted earlier (24 hours after infection) on the addition of HT (P = 0.001). At 2 to 4 weeks after infection, GAG thickness among all cohorts was not significantly different from baseline. In addition, quantitative reverse transcription-polymerase chain reaction analysis revealed that GAG biosynthesis is altered by estrogen status at basal level and on infection.

CONCLUSIONS

The GAG layer is dynamically altered during the course of UTI. Our data show that HT positively regulates GAG layer thickness over time, as well as the composition of the GAGs. In addition, the GAG sulfation status can be influenced by estrogen levels in response to UPEC infection. The protective effects of the GAG layer in UTI may represent pharmacologic targets for the treatment and prevention of postmenopausal UTI.