Hydrogen sulfide and inflammatory joint diseases

[Abstract] Background: Rheumatoid arthritis (RA) and osteoarthritis (OA) are widespread rheumatic diseases characterized by persistent inflammation and joint destruction. Hydrogen sulfide (H2S) is an endogenous gas with important physiologic functions in the brain, vasculature and other organs. Recent studies have found H2S to be a mediator in inflammatory joint diseases. Objective: This review summarizes the recent literature in this area highlighting relevant developments. Conclusions: Several authors have found that H2S exhibited anti-inflammatory, anti-catabolic and/or anti-oxidant effects in rodent models of acute arthritis and in in vitro models using human synoviocytes and articular chondrocytes from RA and OA tissues. The earliest studies used fast-dissolving salts, such as NaSH, but GYY4137, which produces H2S more physiologically, shortly appeared. More recently still, new H2S-forming compounds that target mitochondria have been synthesized. These compounds open exciting opportunities for investigating the role of H2S in cell bioenergetics, typically altered in arthritides. Positive results have also been obtained when H2S is administered as a sulphurous water bath, an option meriting further study. These findings suggest that exogenous supplementation of H2S may provide a viable therapeutic option for these diseases, particularly in OA

Impairment of hydrogen sulfide synthesis in chondrocytes under high glucose environment: a link between type 2 diabetes and osteoarthritis

Poster presentatio

Effect of hydrogen sulfide sources on inflammation and catabolic markers on interleukin 1β-stimulated human articular chondrocytes

[Abstract] Objective. Hydrogen sulfide (H2S), the third gasotransmitter together with NO and CO, is emerging as a regulator of inflammation. To test if it might offer therapeutic value in the treatment of osteoarthritis (OA) we evaluated the effects of two exogenous sources of H2S, NaSH and GYY4137, on inflammation and catabolic markers that characterize OA. Method. Human chondrocytes (CHs) were isolated from OA tissue. Cells were stimulated with a pro-inflammatory cytokine (interleukin-1β, IL1β, 5 ng/ml) and the ability of the two H2S sources to ameliorate its effects on the cells was tested. Nitric oxide (NO) production was quantified through the Griess reaction. Protein levels of inducible NO synthase (NOS2) and matrix metalloproteinase 13 (MMP13) were visualized through immunocytochemistry (ICC). Relative mRNA expression was quantified with qRT-PCR. Prostaglandin-2 (PGE-2), interleukin 6 (IL6) and MMP13 levels were measured with specific EIAs. NFκB nuclear translocation was visualized with immunofluorescence. Results. Both H2S sources led to significant reductions in NO, PGE-2, IL6 and MMP13 released by the cells and at the protein level. This was achieved by downregulation of relevant genes involved in the synthesis routes of these molecules, namely NOS2, cyclooxigenase-2 (COX2), prostaglandin E synthase (PTGES), IL6 and MMP13. NFκB nuclear translocation was also reduced. Conclusion. NaSH and GYY4137 show anti-inflammatory and anti-catabolic properties when added to IL1β activated osteoarthritic CHs. Supplementation with exogenous H2S sources can regulate the expression of relevant genes in OA pathogenesis and progression, counteracting IL1β pro-inflammatory signals that lead to cartilage destruction in part by reducing NFκB activation.Instituto de Salud Carlos III; CIBER BBN CB06/01/004

El sulfuro de hidrógeno ejerce efectos anti-catabólicos en cartílago articular artrósico in vitro

[Resumen] El sulfuro de hidrógeno (H2S), compuesto activo de las aguas mineromedicinales sulfuradas, ha demostrado ser un protector tisular en varias patologías. Nuestros resultados previos demostraron que NaSH y GYY4137, dos compuestos sintéticos que producen H2S, presentan efectos anti-inflamatorios y anti-catabólicos en condrocitos procedentes de pacientes con artrosis (OA) estimulados con interleuquina 1β (IL1β). En el presente trabajo se investigó si estos mismos compuestos inhiben también los procesos catabólicos directamente en cartílago humano artrósico

Platelet-rich plasma in osteoarthritis treatment: review of current evidence

Review[Abstract] Platelet-rich plasma (PRP) is defined as a volume of plasma with a platelet concentration higher than the average in peripheral blood. Many basic, preclinical and even clinical case studies and trials report PRP’s ability to improve musculoskeletal conditions including osteoarthritis, but paradoxically, just as many conclude it has no effect. The purpose of this narrative review is to discuss the available relevant evidence that supports the clinical use of PRP in osteoarthritis, highlighting those variables we perceive as critical. Here, recent systematic reviews and meta-analyses were used to identify the latest randomized controlled trials (RCTs) testing a PRP product as an intra-articular treatment for knee osteoarthritis, compared with an intra-articular control (mostly hyaluronic acid). Conclusions in the identified RCTs are examined and compared. In total, five recent meta-analyses and systematic reviews were found meeting the above criteria. A total of 19 individual trials were identified in the five reviews but only 9 were level of evidence I RCTs, and many had moderate or high risks of bias. At present, results from these RCTs seem to favor PRP use over other intra-articular treatments to improve pain scales in the short and medium term (6–12 months), but the overall level of evidence is low. As a result, clinical effectiveness of PRP for knee osteoarthritis treatment is still under debate. This is, prominently, the result of a lack of standardization of PRP products, scarceness of high quality RCTs not showing high risks of bias, and poor patient stratification for inclusion in the RCTs.Insituto de Salud Carlos III PI12/00329Insituto de Salud Carlos III; PI16/0212

Hydrogen sulfide biosynthesis is impaired in the osteoarthritic joint

[Abstract] Osteoarthritis (OA) is the most common form of arthritis and it is a leading cause of disability in the elderly. Its complete etiology is not known although there are several metabolic, genetic, epigenetic, and local contributing factors involved. At the moment, there is no cure for this pathology and treatment alternatives to retard or stop its progression are intensively being sought. Hydrogen sulfide (H2S) is a small gaseous molecule and is present in sulfurous mineral waters as its active component. Data from recent clinical trials shows that balneotherapy (immersion in mineral and/or thermal waters from natural springs) in sulfurous waters can improve OA symptoms, in particular, pain and function. Yet, the underlying mechanisms are poorly known. Hydrogen sulfide is also considered, with NO and CO, an endogenous signaling gasotransmitter. It is synthesized endogenously with the help of three enzymes, cystathionine gamma-lyase (CTH), cystathionine beta-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MPST). Here, the expression of these three enzymes was demonstrated by quantitative real-time polymerase chain reaction (qRT-PCR) and their protein abundance [by immunohistochemistry and Western blot (WB)] in human articular cartilage. No significant differences were found in CBS or CTH expression or abundance, but mRNA and protein levels of 3-MPST were significantly reduced in cartilage form OA donors. Also, the biosynthesis of H2S from OA cartilage, measured with a specific microelectrode, was significantly lower than in OA-free tissue. Yet, no differences were found in H2S concentration in serum from OA patients and OA-free donors. The current results suggest that reduced levels of the mitochondrial enzyme 3-MPST in OA cartilage might be, at least in part, responsible for a reduction in H2S biosynthesis in this tissue and that impaired H2S biosynthesis in the joint might be a contributing factor to OA. This could contribute to explain why exogenous supplementation of H2S, for instance with sulfurous thermal water, has positive effects in OA patients.Instituto de Salud carlos III; PI12/00329Instituto de Salud Carlos III; PI16/02124Instituto de Salud Carlos III; RETIC-RIER-RD12/0009/0018Xunta de Galicia; IN607A 2017/1

Intra-articular administration of hydrogen sulphide ameliorates severity of experimental osteoarthritis

Conference abstrac

Reduced Levels of H₂S in Diabetes-Associated Osteoarthritis Are Linked to Hyperglycaemia, Nrf-2/HO-1 Signalling Downregulation and Chondrocyte Dysfunction

[Abstract] Different findings indicate that type 2 diabetes is an independent risk factor for osteoarthritis (OA). However, the mechanisms underlying the connection between both diseases remain unclear. Changes in the balance of hydrogen sulphide (H₂S) are thought to play an important role in the pathogenesis of diabetes and its complications, although its role is still controversial. In this study, we examined the modulation of H₂S levels in serum and chondrocytes from OA diabetic (DB) and non-diabetic (non-DB) patients and in cells under glucose stress, in order to elucidate whether impairment in H₂S-mediated signalling could participate in the onset of DB-related OA. Here, we identified a reduction in H₂S synthesis in the cartilage from OA-DB patients and in cells under glucose stress, which is associated with hyperglycaemia-mediated dysregulation of chondrocyte metabolism. In addition, our results indicate that H₂S is an inductor of the Nrf-2/HO-1 signalling pathway in cartilage, but is also a downstream target of Nrf-2 transcriptional activity. Thereby, impairment of the H₂S/Nrf-2 axis under glucose stress or DB triggers chondrocyte catabolic responses, favouring the disruption of cartilage homeostasis that characterizes OA pathology. Finally, our findings highlight the benefits of the use of exogeneous sources of H₂S in the treatment of DB-OA patients, and warrant future clinical studies.This research was funded by grant PI19/01206 from the Fondo de Investigación Sanitaria, integrated in the National Plan for Scientific Program, Development, and Technological Innovation 2013–2016 and funded by the Instituto de Salud Carlos III (ISCIII)-General Subdirection of Assessment and Promotion of Research-European Regional Development Fund (FEDER) “A way of making Europe”, and also by grants ED431B 2020/55 (Grupos con Potencial de Crecemento 2020) and IN607A 2021/7 (Grupos de Referencia Competitiva) from Xunta de Galicia. The study was also supported by the Biomedical Research Network Centre (CIBER), an initiative of ISCIII. C.V.-G. thanks Xunta de Galicia for his postdoctoral contract (grant number ED481D 2017/023)Xunta de Galicia; ED431B 2020/55Xunta de Galicia; IN607A 2021/7Xunta de Galicia; ED481D 2017/02

Effect of balneotherapy in sulfurous water on an in vivo murine model of osteoarthritis

[Abstract] Osteoarthritis (OA) is a chronic joint disease that results in progressive cartilage destruction and subsequently joint dysfunction. Growing evidence indicates beneficial impact of balneological interventions in OA; however, their mechanisms of action are still unclear. Here, we evaluate the effect of balneotherapy in sulfurous water in an OA experimental model. Experimental OA was induced in Wistar rats by transection of the medial collateral ligament and removal of the medial meniscus of the left knee. Animals were randomized into three groups: non-treated (control) and balneotherapy using sulfurous water (SW) or tap water (TW). Macroscopic evaluation was performed, as well as evaluation of pain levels and analysis of motor function by rotarod test. Histopathological changes in articular cartilage and synovium were also evaluated. The presence of matrix metalloproteinase-13 (MMP-13) and oxidative damage markers was assessed by immunohistochemistry. Joint destabilization induced joint thickening, loss of joint flexion, and increased levels of pain. At day 40, animals from SW group presented lower pain levels than those from control group. Experimental OA also affected motor function. Balneotherapy in sulfur-rich water significantly improved joint mobility in relation to that in tap water. Besides, we observed that cartilage deterioration was lower in SW group than in the other two groups. Likewise, SW group showed reduced levels of MMP-13 in the cartilage. Conversely, we failed to observe any modulation on synovial inflammation. Finally, balneotherapy in sulfurous water diminished the presence of oxidative damage markers. Our results suggest the beneficial effect of balneotherapy in sulfur-rich water on an experimental model of OA, showing a reduced cartilage destruction and oxidative damage. Thus, these findings support the use of balneotherapy as a non-pharmacological treatment in OA.Instituto de Salud Carlos III; PI16/02124Xunta de Galicia; AGRUP2015/05 CICA-INIBICXunta de Galicia; IN607A 2017/11(GPC

Long-term effects of hydrogen sulfide on the anabolic-catabolic balance of articular cartilage in vitro

[Abstract] Healthy cartilage maintenance relies on an equilibrium among the anabolic and catabolic processes in chondrocytes. With the onset of osteoarthritis (OA), increased interleukin (IL)-1β levels induce an inhibition of the synthesis of extracellular matrix (ECM) proteins, as well as an increase in proteases. This eventually leads to a predominance of the catabolic phenotype and the progressive loss of articular cartilage. Hydrogen sulfide (H2S) is a small gaseous molecule recognized as the third endogenous gasotransmitter. When administered exogenously, it has shown anti-inflammatory and anti-catabolic properties in several in vitro and in vivo models. Here, OA cartilage disks were co-cultured in vitro with IL-1β (5 ng/ml) and NaSH or GYY4137 (200 or 1000 μM) for 21 days. The ability of these two H2S-producing compounds to avoid long term extracellular matrix (ECM) destruction was evaluated. We used a glycosaminoglycan (GAG) quantification kit histology and immunohistochemistry (IHC) to evaluate matrix proteins degradation and matrix metalloproteinases (MMP) abundance. Through the GAGs quantification assay, safranin O (S-O) and toluidine blue (TB) stains, and keratan/chondroitin sulfate (KS/ChS) IHCs it was shown that co-stimulation with H2S-forming reagents effectively avoided GAGs destruction. Both Masson's trichrome (MT) stain and collagen (col) type II IHC, as well as aggrecan (agg) IHC demonstrated that not only were these proteins protected but even promoted, their abundance being higher than in the basal condition. Further, stains also demonstrated that positivity in the inter-territorial and intra-cellular for the different matrix components were rescued, suggesting that NaSH and GYY4137 might also have pro-anabolic effects. In addition, a clear protective effect against the increased MMPs levels was seen, since increased MMP3 and 13 levels were subsequently reduced with the co-stimulation with sulfide compounds. In general, GYY4137 was more effective than NaSH, and increasing the dose improved the results. This study demonstrates that H2S anti-catabolic effects, which had been previously proven in short-term (24–48 h) in vitro cellular models, are maintained over time directly in OA cartilage tissue.Instituto de Salud Carlos III; PI12/0032