Effect of hyaluronic acid on chondrocyte apoptosis

Histological features of knee osteoarthritis treated with triamcinolone acetonide and hyaluronic acid

Osteoarthritis (OA) is one of the most common degenerative joint diseases leading to disability in the end stage. Although intra-articular triamcinolone acetonide (TA) is one of the OA treatments that have been widely used, the side effects of such corticosteroids are still controversial. Intra-articular hyaluronic acid (HA) injection is another therapeutic option for patients with OA who do not want to use corticosteroids because of their side effects. However, the difference between the histological features associated with TA and HA in the treatment of OA remains unclear. Thus, the present study aimed to compare the histological effects of TA and HA on the cartilage of patients with knee OA. In the current study, 31 patients diagnosed with grade 3-4 knee OA on the Kellgren-Lawrence radiographic grading scale were separated into three groups: TA (n=12); HA (n=7) and untreated group (n=12). Histological examination of the whole articular cartilages of the patients was performed with hematoxylin and eosin and Alcian staining, as well as using a TUNEL assay. Clinical data such as cartilage thickness, structural and component deterioration, proteoglycan levels, apoptosis and empty lacunae were compared between the three groups. The results showed a high level of deterioration in both TA and HA groups but not in the untreated group, although the thickness of cartilage in the HA group was lower compared with that in the TA and untreated groups. The proteoglycan levels in the TA group were lower compared with those in the HA group. Moreover, the number of empty lacunae in the HA group was higher compared with that in the TA group, while no difference in apoptosis was found between TA and HA groups. A significant difference was not found in the histological staining between TA and HA groups. On the other hand, a significant difference was found in cartilage deterioration between the medial and lateral sides in these groups. TA and HA groups showed comparable histological results. TA injection is cheaper and easier but has more adverse effects for patients with knee OA than HA injection. Therefore, orthopaedists should select TA or HA based on the economic and specific needs of patients.

Hyaluronic Acid Oligosaccharide Derivatives Alleviate Lipopolysaccharide-Induced Inflammation in ATDC5 Cells by Multiple Mechanisms

High molecular weight hyaluronic acids (HMW-HAs) have been used for the palliative treatment of osteoarthritis (OA) for decades, but the pharmacological activity of HA fragments has not been fully explored due to the limited availability of structurally defined HA fragments. In this study, we synthesized a series glycosides of oligosaccharides of HA (o-HAs), hereinafter collectively referred to as o-HA derivatives. Their effects on OA progression were examined in a chondrocyte inflammatory model established by the lipopolysaccharide (LPS)-challenged ATDC5 cells. Cell Counting Kit-8 (CCK-8) assays and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) showed that o-HA derivatives (≤100 μg/mL) exhibited no cytotoxicity and pro-inflammatory effects. We found that the o-HA and o-HA derivatives alleviated LPS-induced inflammation, apoptosis, autophagy and proliferation-inhibition of ATDC5 cells, similar to the activities of HMW-HAs. Moreover, Western blot analysis showed that different HA derivatives selectively reversed the effects of LPS on the expression of extracellular matrix (ECM)-related proteins (MMP13, COL2A1 and Aggrecan) in ATDC5 cells. Our study suggested that o-HA derivatives may alleviate LPS-induced chondrocyte injury by reducing the inflammatory response, maintaining cell proliferation, inhibiting apoptosis and autophagy, and decreasing ECM degradation, supporting a potential oligosaccharides-mediated therapy for OA.

State of art in intra-articular hip injections of different medications for osteoarthritis: a systematic review

BACKGROUND

Intra-articular hip injections for osteoarthritis represent a useful instrument to reduce pain and disability in the common clinical practice. Several medications can be injected locally with different level of evidence-based efficacy.

OBJECTIVE

The objective of this systematic review is to investigate the effectiveness of intra-articular injections of different medications or substances for the pain treatment and the management of disability in subjects affected by hip osteoarthritis.

METHODS

Two reviewers selected independently randomised controlled trials published in the last 10 years, using PubMed and Scopus databases. The risk of bias was evaluated with Cochrane library assessment tool.

RESULTS

12 randomised controlled trials have been selected. We found 8 papers comparing hyaluronic acid with platelet rich plasma, with corticosteroids and with saline solution; 1 paper compares two types of hyaluronic acid with different molecular weights; 3 papers study the effects of corticosteroids alone or compared to ketorolac or saline solution.

CONCLUSIONS

The studies reviewed were heterogeneous regarding sample size, level of osteoarthritis, evaluated with Kellegren-Lawrence score, medications used and follow up timings. However, we have observed that intra-articular injections of platelet-rich plasma seem to decrease pain at short term and disability at long term, in patients affected by hip osteoarthritis better than hyaluronic acid. The association of hyaluronic acid and corticosteroids could give better results compared to hyaluronic acid alone, while the use of intra-articular ketorolac and saline solution requires more studies.

Hyaluronic Acid-Functionalized Hybrid Gelatin-Poly-L-Lactide Scaffolds with Tunable Hydrophilicity

In this study, we describe the production of hybrid gelatin-poly-L-lactide electrospun scaffolds whose hydrophilicity was controlled by binding increasing concentrations of hyaluronic acid (HA). We show that cross-linking has advantages over coating when aiming to functionalize the scaffolds with HA. The here described scaffolds structurely mimicked the complexity of the extracellular matrix, and when excited by second harmonic generation, they produced a signal that is typical of collagen-containing biological fibers. Fluorescence lifetime imaging microscopy (FLIM) was used to marker-independently monitor the growth of human dermal fibroblasts on the electrospun scaffolds using reduced (phosphorylated) nicotinamide adenine dinucleotide as target. Benefitting from the different fluorescence lifetimes of the polymer and the endogenous cellular fluorophore, we were able to distinguish and separate the signals produced by the cells from the signals generated by the electrospun scaffolds. FLIM further allowed the detection of metabolic differences in the cells seeded on the HA-functionalized scaffolds compared with cells that were cultured on nonfunctionalized control scaffolds.

Effects of Streptococcus thermophilus on anterior cruciate ligament transection-induced early osteoarthritis in rats

Osteoarthritis (OA) is the most common joint disorder and is classically defined as a progressively degenerative disease of articular cartilage. It manifests as joint pain and disability and currently has no comprehensive treatments. The primary purpose of the present study was to test the effects of probiotics, Streptococcus thermophilus (TCI633), on anterior cruciate ligament transection (ACLT)-induced experimental osteoarthritis (OA) in rats. In the current study, the experimental groups were given TCI633 (5x10⁹, 5x10¹⁰ and 5x10¹¹ CFU/kg/day) and glucosamine sulfate (250 mg/kg) between week 8 and 20 following ACLT. The results showed that oral administration of TCI633 and glucosamine had significant therapeutic effects on pain behaviors and knee swelling. Dose-dependent effects of TCI633 were also observed in ACLT-treated rats. Histopathological analysis demonstrated that ACLT+TCI633 (5x10⁹, 5x10¹⁰ and 5x10¹¹ CFU/kg/day) improved the synovial inflammation and cartilage damage of ACLT rats. Histology evaluation using the Osteoarthritis Research Society International system and synovial inflammatory score analysis showed the dose-dependent inhibition of TCI633 on synovial inflammation and cartilage damage. Immunohistochemical staining and TUNEL apoptosis staining showed that TCI633 could effectively increase the expression of type II collagen and reduce the amount of chondrocyte apoptosis in cartilage. Therefore, the present study demonstrated that oral intake of TCI633 could significantly suppressing pain behavior, reduce joint swelling and synovial tissue inflammation and increase type II collagen expression in cartilage. There was also a reduction in chondrocyte apoptosis and decreased progression of OA in ACLT-treated rats.

Anti‑chondrocyte apoptosis effect of genistein in treating inflammation‑induced osteoarthritis

Osteoarthritis (OA) is a chronic disease that is mainly characterized by chondrocyte degeneration. Inflammatory mediators participate in the development of OA, leading to chondrocyte apoptosis and destruction of the cartilage. Genistein is the major active component of isoflavone, with a chemical composition and a biological effect that is similar to that of estrogens, which prevents the degradation of cartilage; however, its underlying mechanisms of action remain unknown. The aim of the present study was to investigate the anti-apoptotic effects of genistein on chondrocytes for the treatment of inflammation-induced OA. Interleukin (IL)-1β was used to establish a chondrocyte OA model. After treatment with different concentrations of genistein, western blotting identified that expression levels of collagen II and aggrecan were increased in a concentration-dependent manner, while caspase 3 expression gradually decreased after genistein application. Moreover, flow cytometry and ELISA results demonstrated that genistein could decrease chondrocyte apoptosis and reduce the levels of tumor necrosis factor (TNF)-α in a dose-dependent manner. Furthermore, the in vitro data were evaluated in an OA rat model. Genistein increased the collagen and acid glycosaminoglycan content, as well as decreased the levels of TNF-α and IL-1β. Genistein also promoted the expression levels of collagen II and aggrecan in the articular cartilage, and decreased the expression of caspase 3, thus alleviating cartilage degradation. In conclusion, the results indicated that genistein mediated inflammation and had an anti-apoptotic role in treating OA. Therefore, genistein may serve as an alternative treatment for OA.

Post-treatment of hyaluronan to decrease the apoptotic effects of carprofen in canine articular chondrocyte culture

A major concern associated with the use of drugs is their adverse side effects. Specific examples of the drugs of concern include antibiotic agents and non-steroidal anti-inflammatory drugs. Despite the presence of a high degree of efficacy for specific conditions, these drugs may deteriorate the surrounding tissues that are exposed to them. Often, carprofen is used for joint inflammation; however, it may stimulate cartilage degradation which can then lead to osteoarthritis progression. In this study, hyaluronan was combined with carprofen treatment in three different applications (pre-treatment, co-treatment and post-treatment) on normal canine chondrocytes to determine whether Hyaluronan (HA) is capable of mitigating the degree of chondrotoxicity of carprofen. Our findings revealed that carprofen at IC₂₀ (0.16 mg/mL) decreased viability and increased nitric oxide (NO) production. Importantly, carprofen induced the apoptosis of canine chondrocytes via the up-regulation of Bax, Casp3, Casp8, Casp9 and NOS2 as compared to the control group. Although the co-treatment of HA and carprofen appeared not to further alleviate the chondrotoxicity of carprofen due to the presence of a high number of apoptotic chondrocytes, post-treatment with HA (carprofen treatment for 24 h and then changed to HA for 24 h) resulted in a decrease in chondrocyte apoptosis by the down-regulation of Bax, Casp3, Casp8, Casp9, NOS2, along with NO production when compared with the treatment of carprofen for 48 h (P < 0.05). These results suggest that HA can be used as a therapeutic agent to mitigate the degree of chondrotoxicity of carprofen.

Therapy for cartilage defects: functional ectopic cartilage constructed by cartilage-simulating collagen, chondroitin sulfate and hyaluronic acid (CCH) hybrid hydrogel with allogeneic chondrocytes

OBJECTIVE

To regenerate functional cartilage-mimicking ectopic cartilage as a source for the restoration of cartilage defects, we used a previously synthesized three-phase collagen, chondroitin sulfate and hyaluronic acid (CCH) hydrogel for the encapsulation of allogeneic chondrocytes with a diffusion chamber system that was buried subcutaneously in the host for 4 weeks and then implanted into a cartilage defect.

METHODS

The CCH hydrogel was prepared and seeded with allogeneic chondrocytes from new-born rabbits, prior to being enveloped in a diffusion chamber that prevents cell ingrowth and vascular invasion of the host, as described previously. A collagen hydrogel (C) was used as the control. The diffusion chamber was embedded subcutaneously in an adult rabbit. 4 weeks later, the regenerated tissue was harvested from the diffusion chamber and then further used for cartilage repair in the same host. To evaluate the regenerated tissue, cell viability assay using calcein-acetoxymethyl (calcein-AM)/propidium iodide (PI) staining, biochemical analysis by examination of total DNA and GAG content, gene expression detection using RT-PCR for Col 1a1, Col 2a1, Acan, and Sox9, biomechanical detection and histological evaluation were implemented.

RESULTS

Analysis of the cell activity and biochemical evaluation in vitro showed that cell proliferation, GAG secretion and gene/protein expression of cartilage specific markers were much higher in the CCH group than those in the C group. The CCH constructed ectopic cartilage tissue in vivo showed the typical characteristics of hyaline cartilage with higher expression of cartilage matrix markers compared with the C groups, as evidenced by morphological and histological findings as well as RT-PCR analysis. Furthermore, ectopic cartilage from CCH successfully facilitated the cartilage restoration, with higher morphological and histological scores and greater mechanical strength than that from C.

CONCLUSION

The three-phase CCH hydrogel, which is closer to natural cartilage matrix and is stiffer than collagen, may replace collagen as the "gold standard" for cartilage tissue engineering. This study may provide a new insight for cartilage repair using ectopic cartilage reconstructed from functional materials and allogeneic cells.

The association between different molecular weights of hyaluronic acid and CHAD, HIF-1α, COL2A1 expression in chondrocyte cultures

The aim of the present study was to investigate the effects of three different formulations of hyaluronic acid (HA): Low molecular weight (MW) Sinovial One^®, medium MW Viscoplus^® and high MW Durolane^®, on chondrocyte proliferation and collagen type II (COL2A1), hypoxia-inducible factor 1α (HIF-1α) and chondroadherin (CHAD) expression in primary chondrocyte cultures. Standard primary chondrocyte cultures were established from osteochondral tissues surgically obtained from 6 patients with gonarthrosis. Cell morphology was evaluated using an inverted light microscope; cell proliferation was determined with a MTT assay and confirmed with acridine orange/propidium iodide staining. Levels of CHAD, COL2A1 and HIF-1α expression were assessed using specific TaqMan gene expression assays. The results demonstrated the positive effect of HA treatment on cell proliferation, which was independent from the MW. COL2A1 expression increased in the medium and high MW HA treated groups. It was observed that HIF-1α expression increased in the high MW treated group alone. CHAD expression increased only in the medium MW HA treated group. Evaluation of gene expression revealed that levels of expression increased as the duration of HA application increased, in the medium and high MW HA treated groups. In terms of increased viability and proliferation, a longer duration of HA application was more effective. Taken together, it may be concluded that the administration of medium and high MW HA may be a successful way of treating diseases affecting chondrocytes in a clinical setting.

Therapeutic efficacy of intra-articular hyaluronan derivative and platelet-rich plasma in mice following axial tibial loading

Objective

To investigate the therapeutic potential of intra-articular hyaluronan-derivative HYADD^® 4-G and/or platelet-rich plasma (PRP) in a mouse model of non-invasive joint injury.

Methods

Non-invasive axial tibial loading was used to induce joint injury in 10-week-old C57BL/6J mice (n = 86). Mice underwent a single loading of either 6 Newton (N) or 9N axial tibial compression. HYADD^® 4-G was injected intra-articularly at 8 mg/mL or 15 mg/mL either before or after loading with or without PRP. Phosphate-buffered-saline was injected as control. Knee joints were harvested at 5 or 56 days post-loading and prepared for micro-computed tomography scanning and subsequently processed for histology. Immunostaining was performed for aggrecan to monitor its distribution, for CD44 to monitor chondrocyte reactive changes and for COMP (cartilage oligomeric matrix protein) as an index for cartilage matrix changes related to loading and cartilage injury. TUNEL assay was performed to identify chondrocyte apoptosis.

Results

Loading initiated cartilage proteoglycan loss and chondrocyte apoptosis within 5 days with slowly progressive post-traumatic osteoarthritis (no cartilage degeneration, but increased synovitis and ectopic calcification after 9N loading) at 56 days. Mice treated with repeated HYADD^® 4-G (15 mg/mL) or HYADD^® 4-G (8 mg/mL) ± PRP or PRP alone exhibited no significant improvement in the short-term (5 days) and long-term (56 days) consequences of joint loading except for a trend for improved bone changes compared to non-loaded joints.

Conclusion

While we failed to show an overall effect of intra-articular delivery of hyaluronan-derivative and/or PRP in reversing/protecting the pathological events in cartilage and synovium following joint injury, some bone alterations were relatively less severe with hyaluronan-derivative at higher concentration or in association with PRP.

In vitro effects of triamcinolone acetonide and in combination with hyaluronan on canine normal and spontaneous osteoarthritis articular cartilage

The purposes of this study were to examine the cartilage degradation effects of triamcinolone acetonide (TA) on normal and osteoarthritic (OA) primary canine chondrocytes and cartilage explants and to examine the cartilage degradation effects of TA in combination with low-molecular-weight hyaluronan (LMWHA). To assess the effects of these drugs on cell culture, 3,[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and real-time PCR were used to measure chondrotoxicity and determine gene expression, respectively. Uronic acid and hydroxyproline remaining in cartilage and histopathology were used to estimate the effects of these drugs on cartilage explants. In chondrocyte cultures, TA reduced chondrocyte viability in a concentration-dependent manner. LMWHA 2.5 mg/ml combined with TA at IC20 (0.09 mg/ml) could increase the viability of normal chondrocytes when compared with TA-treated alone. TA at IC20 induced down-regulation of ACAN and induced up-regulation of ADAMTS5 in canine normal chondrocytes. TA at IC20 (0.11 mg/ml) up-regulated ADAMTS5, MMP2, MMP3, MMP13, and ACAN expression in canine OA chondrocytes. In explant culture, TA at 1.25, 2.5, and 5 mg/ml increased the severity of structural damage, chondrocyte loss and cluster formation, and proteoglycan loss in OA cartilage. LMWHA could decrease the chondrotoxicity of TA at IC20 only in normal chondrocytes, as observed by chondrocyte viability. The combination of LMWHA and TA did not show clearly beneficial effects in all other normal and OA samples. Consequently, using TA alone or in combination with LMWHA in OA cartilage should be of concern because it may lead to cartilage destruction.