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HLA and NLRP3 play an important role in the development of various autoimmune and autoinflammatory diseases. Gout is an autoinflammatory disease associated with multiple genetic and environmental factors. The objective of the present study was to evaluate the interaction and association between genetic polymorphisms of HLA-B and the NLRP3 gene in Mexican patients with gout.Eighty-one patients with gout were included and compared with 95 healthy subjects. The polymorphisms rs4349859, rs116488202, rs2734583 and rs3099844 (within the HLA-B region) and rs3806268 and rs10754558 of the NLRP3 gene were genotyped using TaqMan probes in a Rotor-Gene device. The interactions were determined using the multifactorial dimensionality reduction (MDR) method, while the associations were determined through logistic regression models. The MDR analysis revealed significant interactions between the rs116488202 and rs10754558 polymorphisms with an entropy value of 4.31% (p 0.0001). Significant risk associations were observed with rs4349859 and rs116488202 polymorphisms (p 0.01); however, no significant associations were observed with the polymorphisms of the NLRP3 gene.The results suggest that HLA-B polymorphisms and their interaction with NLRP3 may contribute to the genetic susceptibility of gout.

Ankylosing spondylitis (AS) is a type of inflammatory arthritis that affects primarily the spine. There is a strong association of the HLA-B*27 allele with AS pathogenesis, but recent studies have demonstrated the participation of ERAP1 gene in the genetic susceptibility. The aim of this study was to determine whether HLA-B tag-single nucleotide polymorphisms (SNPs) and ERAP1-related genetic variations associated with AS have equal or similarly performance in patients´ screening compared to HLA-B*27 standard genotyping in Mexican population. Genomic DNA from patients with AS and population-based controls from Mexico City was analyzed for five single nucleotide polymorphisms (SNPs): rs4349859, rs13202464, rs116488202, tagging HLA-B*27; and rs30187 and rs27044 in ERAP1 gene. TaqMan genotype assay method was used for SNPs genotyping. We found a significant association between AS and the heterozygote genotypes and minor alleles of the HLA-B*27 tag-SNPs, as well as for their haplotypes. With respect to ERAP1 polymorphisms, no significant associations were observed (p > 0.05). The sensitivity and specificity analysis showed values of 0.96 and 1.00 for the rs4349859 SNP, and 0.96 and 0.94 for the rs116488202 SNP, respectively, in detecting HLA-B*27 compared to the B27 test as the gold standard. HLA-B*27 tag-SNPs are associated with AS susceptibility; furthermore, the rs4349859 SNP by its own have an outstanding performance in detecting HLA-B*27 and therefore can be proposed as screening marker in the identification of HLA-B*27 in our population.

Humans do not produce uricase, an enzyme responsible for degrading uric acid. However, some bacteria residing in the gut can degrade one-third of the dietary and endogenous uric acid generated daily. New insights based on metagenomic and metabolomic approaches provide a new interest in exploring the involvement of gut microbiota in gout. Nevertheless, the exact mechanisms underlying this association are complex and have not been widely discussed. In this study, we aimed to review the evidence that suggests uric acid extrarenal excretion and gut microbiome are potential risk factors for developing gout. A literature search was performed in PubMed, Web of Science, and Google Scholar using several keywords, including "gut microbiome AND gout". A remarkable intestinal dysbiosis and shifts in abundance of certain bacterial taxa in gout patients have been consistently reported among different studies. Under this condition, bacteria might have developed adaptive mechanisms for de novo biosynthesis and salvage of purines, and thus, a concomitant alteration in uric acid metabolism. Moreover, gut microbiota can produce substrates that might cross the portal vein so the liver can generate de novo purinogenic amino acids, as well as uric acid. Therefore, the extrarenal excretion of uric acid needs to be considered as a factor in gout development. Nevertheless, further studies are needed to fully understand the role of gut microbiome in uric acid production and its extrarenal excretion, and to point out possible bacteria or bacterial enzymes that could be used as probiotic coadjutant treatment in gout patients.

Tobacco use has a negative impact on health due to its relationship with the development of high-mortality diseases, such as pulmonary cancer. However, the effect of cadmium (Cd), present in tobacco smoke, on the development of joint diseases has been scarcely studied. The objective of this review is to discuss the evidence regarding the mechanisms by which Cd exposure, through tobacco smoke, may lead to the development of osteoarthritis (OA), osteoporosis (OP), and rheumatoid arthritis (RA). There’s evidence suggesting a string association between moderate to severe OA development and tobacco use, and that a higher blood concentration of Cd can trigger oxidative stress (OS) and inflammation, favoring cartilage loss. At the bone level, the Cd that is inhaled through tobacco smoke affects bone mineral density, resulting in OP mediated by a decrease in the antioxidant enzymes, which favors the bone resorption process. In RA, tobacco use promotes the citrullination process through Cd exposure, as well as an increase in OS and inflammation. Understanding how tobacco use can increase the damage at the articular level mediated by a toxic metal, i.e., Cd, is important. Finally, proposing prevention, control, and treatment strategies for frequently disabling diseases, such as OA, OP, and RA to reduce its prevalence in the population.

Rheumatoid arthritis (RA) is an autoimmune disease that affects approximately 1% of the worldwide population. In recent decades, oxidative stress (OS) has been shown to be involved in the progression of this disease through DNA, lipid and protein damage, resulting in synovial inflammation. There are many causes of OS; metabolism is involved in the production of reactive oxygen species (ROS) but pollution, diet and microbiota imbalances could lead to the overproduction of these ROS. A decade of research focused on understanding how OS is promoted by known RA risk factors is described herein. The use of antioxidants represents an integrative treatment for patients with rheumatoid arthritis, given the evidence of the damage caused by oxidative stress in this disease. Understanding the different factors that contribute to the development and progression of RA, such as OS, will pave the way not only for better pharmacological treatments but also for recommendations for dietary and health behaviours that will benefit patients with this disease.

Osteoarthritis (OA) is the gradual loss of articular cartilage and involves several tissues, such as the synovial membrane, meniscus, ligaments, and adipose tissue known as Hoffa fat pad. There are largely unexplored factors that lead to OA development, such as the impact of exposure to heavy metals like cadmium (Cd) on the viability of cells in the knee joint tissue. The objective of this report was to identify the cell type with the highest susceptibility to Cd toxicity with respect to cell viability and death. Our findings showed that a concentration as low as 3 μM cadmium chloride for 12 h affects the viability of synovial cells, and a concentration of 10 μM affects Hoffa cells. Our results suggest that Cd can affect the viability of synovial and chondral cells primarily. In contrast, Hoffa cells were less susceptible, likely because Cd favors the production of pro-inflammatory cytokines before triggering their death as part of its damage mechanism at the articular level.

Prostate cancer (PC) is a polygenic disease with broad differences across ethnicities. BRCA1/2 and VDR have exhibited a featured genetic contribution to PC development in European populations. Nonetheless, its contribution in Latino populations specifically among Mexican men, where 70% of PC cases are detected in advanced stages, is still unknown. The contribution of seven polymorphisms in BRCA1/2 and VDR genes to PC susceptibility was evaluated in 370 incident PC cases and 759 age-matched (±5 years) controls belonging to the Mexican population. Based on Gleason score at diagnosis, PC cases were classified as well-differentiated PC (Gleason

Articular cartilage is an avascular tissue with a structure that allows it to support and cushion the overload of the surfaces in contact. It maintains its metabolic functions due to the contribution of different signaling pathways. However, several factors play a role in its deterioration, allowing to the development of osteoarthritis (OA), and one of the major factors is genetic. Our goal was to identify gene–gene interactions (epistasis) between five signaling pathways involved in the articular cartilage metabolism as possible indicators of OA risk. We applied the Multifactor-Dimensionality Reduction (MDR) method to identify and characterize the epistasis between 115 SNPs located in 73 genes related to HIF-1α, Wnt/β-catenin, cartilage extracellular matrix metabolism, oxidative stress, and uric acid transporters. Ninety three patients diagnosed with primary knee OA and 150 healthy controls were included in the study. Genotyping was performed with the OpenArray system, the statistical analysis was carried out with the STATA software v14, and epistasis was analyzed with the MDR software v3.0.2. The MDR analysis revealed that the best interaction model was between polymorphisms rs17786744 of the STC1 gene and rs2615977 of the COL11A1 gene, with an entropy value of 4.44%, CVC 8/10, OR 5.60, 95% CI 3.27–9.59, p

Objective To explore genetic polymorphisms of the Wnt/β-catenin signalling pathway in primary SS (PSS). Methods We included 98 patients with PSS and 165 healthy volunteers. Genomic DNA was extracted from peripheral blood samples. Through an open-array platform of low density, we genotyped 25 polymorphisms from 14 genes (WISP1, DKK1, SOST, FRZB, LRP1, LRP4, LRP5, LRP6, GSKB, ADAMTS5, GDF5, FMN2, ADIPOQ and COL11A1) involved in the Wnt/β-catenin signalling pathway. We compared the allelic and genotypic frequencies with Fisher’s exact test and logistic regression analysis adjusted by age, gender and individual admixture, as well as bootstrap-resampling analysis. We assessed the gene–gene interaction by the multifactor dimensionality reduction method. Results We found a positive significant association with four polymorphisms: LRP5 rs606989, FRZB rs409238, GSK3B rs2037547 and ADIPOQ rs2241766. All of them conferred risk for PSS, being the highest among subjects carrying three to four risk alleles (P < 0.001). According to a multifactor dimensionality reduction analysis, the best models included the LRP5 (rs606989), FRZB (rs409238) and ADIPOQ (rs2241766) polymorphisms. Conclusion LRP5, FRZB and ADIPOQ genes related in the Wnt/β-catenin signalling pathway increased the risk of PSS. Further research is needed to establish their functional role in this clinical entity.

Articular cartilage is the target tissue of osteoarthritis (OA), and because it lacks capillary networks, the microenvironment is hypoxic. Hypoxia inducible factor-1 alpha (HIF-1α) regulates the homeostasis of this tissue. The aim of this study was to investigate whether genetic polymorphisms of the HIF-1α signaling pathway are involved in the development of knee OA. We performed a case-control association study and genotyped 134 knee OA patients and 267 healthy controls. All participants were genotyped in order to evaluate 42 SNPs from 22 genes involved in the HIF-1α signaling pathway using the OpenArray technology. Gene-gene interactions (epistasis) were analyzed using the multifactor dimensionality reduction (MDR) method. The MDR analysis showed epistasis between AKT2 (rs8100018) and IGF1 (rs2288377), AKT2 (rs8100018) and IGF1 (rs35767), IGF1 (rs35767) and COL2A1 (rs1793953), and between GSK3B (rs6438552) and IGF1 (rs35767) polymorphisms, with information gain values of 21.24%, 8.37%, 9.93%, and 5.73%, respectively. Additionally, our model allowed us to identify high- and low-risk genotypes among COL2A1 rs1793953, GSK3B rs6438552, AKT2 rs8100018, and IGF1 rs35767 polymorphisms. Knowing the interactions of these polymorphisms involved in HIF-1α signaling pathway could provide a new diagnostic support tool to identify individuals at high risk of developing knee OA.

Synovial cells play a crucial part in gouty arthritis, with different features for the inflammation within the joint. However, there is no information about how the synoviocytes can mediate the activation of inflammation. We hypothesized that the process of monosodium urate (MSU) crystal uptake alters the inflammatory response of synoviocytes through regulation of unknown mechanisms. Synoviocytes were stimulated with MSU crystals, and the phagocytosis index (PhIx) was evaluated by counting of cells with MSU ingested using polarized light microscopy. Additionally, transmission electron microscopy and flow cytometry were performed. Secretion of cytokines was measured by a panel of immunoassays. Changes in gene expression of hypoxia-inducible factor-1 ( HIF1A), von Hippel-Lindau ( VHL), and vascular endothelial growth factor ( VEGF) were evaluated by quantitative real-time PCR (qRT-PCR). Protein levels were detected by ELISA. MSU crystals induced a time-dependent increase in PhIx and the formation of numerous secretory vesicles and cavities located in the cytoplasm. Culture supernatants of MSU-treated cells had high levels of the cytokines IL-1β, IL-6, IL-8, TNF-α, and MCP-1, and the growth factors NGF and HGF. The decrease in HIF1A gene expression was 0.58-fold, and overexpression of VHL and VEGF genes was 1.98- and 4-fold, respectively, in MSU-treated synoviocytes compared to untreated cells. Additionally, VEGF levels were increased. The identification of phagocytosis of MSU crystals triggering an inflammatory cellular state in synoviocytes suggests a possible mechanism of synovial activation in the pathogenesis of crystal-induced arthritis. Impact statement Gout is distinguished by an inflammatory process that is mediated by phagocytosis of monosodium urate (MSU) crystals in synoviocytes by regulation of unknown mechanisms. Here we suggest that the synovial cells play a crucial role in gouty arthritis by activating inflammation by MSU uptake and increasing the secretion of pro-inflammatory cytokines IL-1β, IL-6, IL-8, TNF-α, MCP-1, and the growth factors NGF and HGF. We discuss some co-existing features in synoviocytes, including anomalous morphologies of the cells, and microvesicle formation, dysregulation in VEGF gene expression. We provide evidence that phagocytosis of MSU crystals triggers an inflammatory cellular state in synoviocytes in the pathogenesis of crystal-induced arthritis.

We hypothesized that the secretion of inflammatory mediators from synoviocytes affects the chondrocyte homeostasis of articular cartilage. This study was a preliminary attempt to elucidate the molecular mechanisms by which soluble mediators obtained from activated synoviocytes induce oxidative stress and inflammation in chondrocytes. We measured the concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), nerve growth factor (NGF), superoxide anion (O2•-), hydrogen peroxide (H2O2), and nitric oxide (NO•) from articular human cells. First, we created a conditional basal medium by exposing synoviocytes (HS) to monosodium urate crystals (CBM). The chondrocytes were exposed to either CBM (CCM), urate crystals directly (CMSU), or remained untreated (CC) as a negative control. Data were analyzed by ANOVA tests; Bonferroni test was performed for multiple comparisons between groups. Interestingly, we observed that mediators of inflammation and oxidative stress were significantly higher in CCM than CMSU and CC groups (P

Few studies have addressed the detection and clinical impact of different crystals in patients with diverse rheumatologic diagnoses in Latin America. The aim of this study was to assess the consistency between the clinical referring diagnosis and the identification of crystals, such as monosodium urate (MSU) and calcium pyrophosphate (CPP), in the synovial fluid (SF) of patients from a Mexican tertiary care institution.We reviewed the results of 264 SF analyses to identify any changes in diagnosis upon SF analysis. We reported patient medical file data on sex, age, diagnosis, and microscopic SF analysis results. We performed consistency analyses between referring diagnoses and SF findings with McNemar's test.The prevalence of MSU crystals in SF was noted in 89.1% of gout cases and 9.09% of cases of calcium pyrophosphate disease (CPPD). CPP crystals were present in 54.5% of CPPD cases, 42.9% of osteoarthritis (OA) cases, and 7.27% of gout cases. Calcium hydroxyapatite (HA) crystals were identified in 5.45% of gout cases, 33.3% of rheumatoid arthritis (RA) cases, 57.1% of OA cases, and 63.6% of CPPD cases. Cholesterol and lipid crystals were present in small proportions in RA cases. Glucocorticoid crystals were observed in 1.85% of gout cases, 44.4% of RA cases, and 42.9% of OA cases. We observed an association of MSU identification with clinical suspicion of gout (P = 0.08), CPP with OA (P = 0.26) and CPPD (P = 0.50). An association was noted between HA and the diagnosis of CPPD (P = 0.84) and OA (P0.99). The number of initial diagnoses that changed upon SF analysis was 14.3%.SF analysis has major diagnostic value regarding MSU crystals and gout. Our findings underscore the importance of SF crystal analysis in identifying the prevalence of crystals in the Mexican population. SF analysis provides for better diagnosis of crystal arthropathies and improves the quality of the medical care that the patient receives. Key Points • Synovial fluid analysis in laboratories from developing countries has been scarce. • In some cases, the initial diagnosis is modified after of synovial fluid analysis. • This study confirmed that synovial fluid analysis exhibits major diagnostic value for urate crystals and gout.

The microwaves-assisted extraction (MAE) for concentration of cherry phytochemicals has seen explored. Polyphenols from cherries, Prunus avium (L.) L., were extracted using a microwave oven at 2,450 MHz, 453 W for a period of 60 s (T60), and was compared versus an unprocessed MAE extract (T0). The extracts were analyzed for total polyphenols, total anthocyanins, and antioxidant capacity. THP-1 cells were stimulated with monosodium urate (MSU) crystals at 150 µg/ml for 24 hr. Cherry extracts were added to cultures concurrently with MSU or 3 hr before MSU addition as pretreatments. Reactive oxygen species (ROS), IL-1β levels, and MSU crystal phagocytosis were evaluated. T60 extract showed a higher concentration of polyphenols, anthocyanins, and antioxidant activity than T0 extract. ROS were inhibited using the 1:800 and 1:1,600 (v:v) dilutions from both extracts, even used as pretreatments. IL-1β levels and MSU crystal phagocytosis were reduced. Cherry is a source of polyphenolic compounds with antioxidant and anti-inflammatory activity. PRACTICAL APPLICATIONS: The cherries and a cherry extract obtained via MAE has benefits as a possible coadjuvant to conventional gout therapy due to attenuate the inflammation and the oxidative stress triggered by monosodium urate crystals in THP-1 cells, which mimic an acute episode of gout.

Articular cartilage and periarticular muscle tissues are strongly affected during knee osteoarthritis (OA). Creatine kinase (CK) is an enzyme expressed in several tissues, but the isoform CK-MM is specific of skeletal muscle, and its serum concentration is used as a biomarker of muscle damage. Genetic variants of the CKM gene have been associated with various pathologies, but to date, there are no reports of association with OA. Due to the rs4884 polymorphism being well represented in the Mexican population, it is used as an ancestry informative marker; thus, the goal of this preliminary report was to evaluate the association of this polymorphism in primary knee OA Mexican patients.Eighty-seven patients with primary knee OA were compared with 107 healthy controls. Serum CK-MM was determined using the dot blot system, and genotyping was performed using the OpenArray system. Logistic regression models were used to assess the association between the rs4884 polymorphism and OA susceptibility adjusting by gender, age, and body mass index.There were no significant differences in serum CK-MM values between patients and controls. The GG genotype and the G allele had a higher frequency in the control group compared with the OA group (24.3% vs. 12.6%, OR = 0.34, 95% CI = 0.14-0.84, P = 0.019; and 40.2% vs. 28.2%, OR = 0.51, 95% CI = 0.32-0.82, P = 0.005, respectively).Our results suggest a protection role of the rs4884 polymorphism against knee OA development; further studies are required to confirm it. Key Points • CK-MM enzyme catalyzes the conversion of creatine and ATP to create phosphocreatine and ADP; this reaction is reversible. • In tissues that consume ATP rapidly, such as skeletal muscle, the phosphocreatine serves as an important energy reservoir. • During knee OA, peripheral muscle tissues of the joint may be affected. • The rs4884 polymorphism of the CKM gene may participate as a protective factor in the development of OA.

Osteosarcoma is the most common bone tumor, mainly affecting adolescents and young adults, and metastatic disease has poor outcomes with a dismal overall survival. Currently, chemotherapy is the standard of care with limited results, finding that new therapies could improve these outcomes. Preclinical and clinical studies have suggested a possible important role of ErbB pathway aberrations in osteosarcoma etiology. The present study shows the effect of afatinib, an irreversible ErbB family blocker in osteosarcoma cell lines. Within a panel of human osteosarcoma cell lines, we addressed cell viability assay using afatinib at increasing concentrations. Motility was measured in wound-healing assays and invasion capacity was assessed in Transwell chamber assays. Finally, to monitor ErbB pathway modulation by afatinib and related compounds, we used Western blot analyses. Cell viability inhibition, as well as a reduction of motility and migration of osteosarcoma cell line were observed after treatment with afatinib. Likewise, in the HOS cell line, afatinib decreased phosphorylation of key components in the ErbB signaling pathway. Afatinib shows relevant antitumor effect in several osteosarcoma cell lines, as it causes a significant impact on cell viability, motility, and migration with a significant decrease in the activation of ErbB pathway activity.

Overweight and inadequate physical fitness are critical variables that impact directly on the health, wellbeing of service members and military readiness, characteristics required to overcome dangerous situations during sea rescues and in the first line of combat in the Mexican Navy. Here we determined the impact of body composition (BC) on physical fitness components (PFC) [cardiorespiratory fitness (CRF) and muscle strength-resistance (MSR)] of 110 marines, rescue swimmers, and divers of the Mexican Navy classified as overweight. We found significant differences in medians of BC and PFC among groups (p

Osteoarthritis (OA) is a complex disease with a multifactorial etiology. The genetic component is one of the main associated factors, resulting from interactions between genes and environmental factors. The aim of this study was to identify gene-gene interactions (epistasis) of the articular cartilage extracellular matrix (ECM) in knee OA. Ninety-two knee OA patients and 147 healthy individuals were included. Participants were genotyped in order to evaluate nine variants of eight genes associated with ECM metabolism using the OpenArray technology. Epistasis was analyzed using the multifactor dimensionality reduction (MDR) method. The MDR analysis showed significant gene-gene interactions between MMP3 (rs679620) and COL3A1 (rs1800255), and between COL3A1 (rs1800255) and VEGFA (rs699947) polymorphisms, with information gain values of 3.21% and 2.34%, respectively. Furthermore, in our study we found interactions in high-risk genotypes of the HIF1AN, MMP3 and COL3A1 genes; the most representative were [AA+CC+GA], [AA+CT+GA] and [AA+CT+GG], respectively; and low-risk genotypes [AA+CC+GG], [GG+TT+GA] and [AA+TT+GA], respectively. Knowing the interactions of these polymorphisms involved in articular cartilage ECM metabolism could provide a new tool to identify individuals at high risk of developing knee OA.

Objective Human mesenchymal stem cells (hMSCs) are a promising source for regenerative medicine, especially mesodermal lineages. Clinical applications require an understanding of the mechanisms for transcriptional control to maintain the desired cell type. The aim of this study was to identify novel markers for differentiation of hMSCs into bone or cartilage with the use of Kartogenin, by RNA analysis using microarray technology, and explore the role of RhoA-Rho associated protein kinase (ROCK) inhibition in these. Methods Commercial human bone marrow derived primary mesenchymal stem cells were purchased from ATCC. Cells were differentiated in vitro in 2-dimensional cultures using Kartogenin as the main cartilage inducer and bone morphogenetic protein 2 for bone differentiation; cells were cultured with and without ROCK inhibitor Y-27632. After 21 days of culture, whole RNA was extracted and analyzed via Affimetrix microarrays. The most significant hits were validated by quantitative polymerase chain reaction. Results We found a total of 1,757 genes that were either up- or downregulated on differentiation, when compared to P1 hMSC (control) at day 0 of differentiation. Two members of the Serpin superfamily, SERPINA9 and SERPINB2, were significantly upregulated in the cartilage groups, whereas they were unchanged in the bone groups with and without ROCK inhibition. Conclusions SERPINA9 and SERPINB2 are novel differentiation markers, and molecular regulator candidates for hMSC lineage commitment toward bone and cartilage, providing a new tool for regenerative medicine. Our study highlights the roles of these 2 genes, with significant upregulation of both in cell cultures stimulated with Kartogenin.

Osteoarthritis (OA) is the most common form of arthritis and is frequently diagnosed and managed in primary care; it is characterized by loss of articular hyaline cartilage, which is a unique connective tissue that physiologically lacks blood vessels. Articular cartilage survives in a microenvironment devoid of oxygen, which is regulated by hypoxia inducible factor (HIF-1α). HIF-1α is considered the main transcriptional regulator of cellular and developmental response to hypoxia. To date, the relevance of HIF-1α in the assessment of cartilage has increased since its participation is essential in the homeostasis of this tissue. Taking into account the new emerging insights of HIF-1α in the scientific literature in the last years, we focused the present review on the potential role of HIF-1α signaling pathway in OA development, especially in how some genetic factors may influence the maintenance or breakdown of articular cartilage. Resumo A osteoartrite (OA) é a forma mais comum de artrite e frequentemente é diagnosticada e gerenciada na atenção primária; é caracterizada por perda da cartilagem articular hialina, um tecido conjuntivo único que fisiologicamente carece de vasos sanguíneos. A cartilagem articular sobrevive em um microambiente desprovido de oxigênio, que é regulado pelo fator induzível por hipóxia-1α (HIF-1α). O HIF-1α é considerado o principal regulador transcricional da resposta celular e de desenvolvimento à hipóxia. Na atualidade, a relevância do HIF-1α na avaliação da cartilagem tem aumentado, já que a sua participação é essencial na homeostase desse tecido. Considerando as novas perspectivas emergentes do HIF-1α na literatura científica nos últimos anos, foca-se a presente revisão no potencial papel da via de sinalização do HIF-1α no desenvolvimento da OA, especialmente no modo como alguns fatores genéticos podem influenciar na manutenção ou ruptura da cartilagem articular.

Objective. To evaluate the allele and genotype frequencies of polymorphic sites ofHIF1AandANKAgenes in primary Sjögren’s syndrome (pSS).Methods. We included 110 patients with pSS and 141 ethnically matched healthy controls. ThreeHIF1Agene polymorphisms(Pro582Ser,Ala588Thr, andC191T)and twoAKNA genepolymorphisms(−1372C>AandPro624Leu)were genotyped using TaqMan probes in a Real-Time PCR instrument. Associations between pSS and genotypes, alleles, and inheritance models of the SNPs of interest were evaluated by logistic regression adjusted by age and gender.Results. TheC/Tgenotype and theTallele of theHIF1A Pro582Serpolymorphism protected against pSS (OR = 0.22; 95% CI = 0.09–0.52;P<0.01; OR = 0.26; 95% CI = 0.12–0.58;P<0.01, resp.), whereas under a recessive model adjusted by age and gender, theAKNA −1372C>Apolymorphism A/A genotype was associated with an increased risk of pSS (OR = 2.60; 95% CI = 1.11–6.12;P=0.03).Conclusions. We identifiedHIF1A Pro582SerTallele andC/Tgenotype as well asAKNA −1372C>Apolymorphism A/A genotype as genetic factors associated with pSS. Further studies in other populations are needed to validate our findings and research is warranted in order to shed some light on their functional implications across biological pathways in this disease.

Epidemiological studies have reported that exposure to toxic metals like cadmium (Cd) may promote the development of musculoskeletal diseases, such as osteoporosis, rheumatoid arthritis (RA), and osteoarthritis (OA), among others. The objective of this review is to summarize the molecular mechanisms of inflammation and oxidative stress activated by Cd at the bone level, particularly in osteoporosis, RA, and OA. Cadmium can increase bone resorption, affect the activity of osteoclasts and calcium (Ca) absorption, and impair kidney function, which favors the development of osteoporosis. In the case of RA, Cd interferes with the activity of antioxidant proteins, like superoxide dismutase (SOD) and catalase (CAT). It also promotes an inflammatory state, inducing the process of citrullination, which affects the proteins of immune response. On the other hand, accumulation of Cd in the tissues and blood of smokers has been related to the development of some musculoskeletal diseases. Therefore, knowing the negative impact of Cd toxicity at the articular level can help understand the damage mechanisms it produces, leading to the development of such diseases.

Overweight produces oxidative stress (OS) on the articular cartilage, with the subsequent risk of developing knee osteoarthritis (OA). Associations between genetic polymorphisms related to OS and OA have been reported, but it is currently unknown whether there exist interactions among them that affect OA development. To identify and evaluate interactions between multiple SNPs related to OS in Mexican knee OA patients. Ninety-two knee OA patients were included in the study, which were compared to 147 healthy controls. Nine variants of six genes (PEPD, AGER, IL6, ADIPOQ, PON1, and CA6) related to OS were genotyped in both study groups through the OpenArray system. Epistasis was analyzed with the multifactor dimensionality reduction (MDR) method. The MDR analysis revealed a significant interaction (p = 0.0107) between polymorphisms rs1501299 (ADIPOQ) and rs662 (PON1), with an entropy value of 9.84%; in addition, high and low risk genotypes were identified between these two polymorphisms. The effect of the interaction between rs1501299 (ADIPOQ) and rs662 (PON1) polymorphisms seems to play an important role in OA pathogenesis; so the epistasis analysis may provide an excellent tool for identifying individuals at high risk for developing OA.

Background An essential element imbalance in the joint might favor gradual degeneration of the articular cartilage. It has been reported that cadmium (Cd) plays an antagonistic role with regards to the presence of essential elements, such as zinc (Zn), iron (Fe), and manganese (Mn), which may favor the development of disabling diseases, like osteoarthritis (OA) and osteoporosis. Methods 3D cultures of human chondrocytes were phenotyped with the Western blot technique and structurally evaluated with histological staining. The samples were exposed to 1, 5, and 10 μM of CdCl2 for 12 h, with a non-exposed culture as control. The concentration of Cd, Fe, Mn, Zn, chromium (Cr), and nickel (Ni) was quantified through plasma mass spectrometry (ICP-MS). The data were analyzed with a Kruskal Wallis test, a Kendall’s Tau test and Spearman’s correlation coefficient with the Stata program, version 14. Results Our results suggest that Cd exposure affects the structure of micromass cultures and plays an antagonistic role on the concentration of essential metals, such as Zn, Ni, Fe, Mn, and Cr. Conclusion Cd exposure may be a risk factor for developing joint diseases like OA, as it can interfere with cartilage absorption of other essential elements that maintain cartilage homeostasis.

The aim of this study is to investigate the prevalence of subclinical ankle involvement by ultrasound in patients with rheumatoid arthritis (RA). The study was conducted on 216 patients with RA and 200 healthy sex- and age-matched controls. Patients with no history or clinical evidence of ankle involvement underwent US examination. For each ankle, tibio-talar (TT) joint, tibialis anterior (TA) tendon, extensor halux (EH) and extensor common (EC) tendons, tibialis posterior (TP) tendon, flexor common (FC) tendon and flexor hallux (FH) tendon, peroneous brevis (PB) and longus (PL) tendons, Achilles tendon (AT) and plantar fascia (PF) were assessed. The following abnormalities were recorded: synovitis, tenosynovitis, bursitis, enthesopathy and rupture. BMI, DAS28, RF ESR and CRP were also obtained. A total of 432 ankles of patients with RA and 400 ankles of healthy controls were assessed. In 188 (87%) patients with RA, US showed ankle abnormalities whereas, in control group, US found abnormalities in 57 (28.5 %) subjects (p = 0.01). The most frequent US abnormality in RA patients was TP tenosynovits (69/216) (31.9 %), followed by PL tenosynovitis (58/216) (26.9 %), TT synovitis (54/216) (25 %), PB tenosynovitis (51/216) (23.6 %), AT enthesopathy (41/216) (19 %) and AT bursitis (22/216) (10.2 %). In 118 RA patients out of 216 (54.6%), a positive PD was found. No statistically significant correlation was found between the US findings and age, disease duration, BMI, DAS28, RF, ESR and CRP. The present study provides evidence of the higher prevalence of subclinical ankle involvement in RA patients than in age- and gender-matched healthy controls identified by US.

The title of the article is incorrectly published in the original article. The correct article title is "Afatinib is active in osteosarcoma cell lines".

Osteoarthritis (OA) is the gradual loss of articular cartilage and decrease in subchondral space. One of the risk factors Exposure to cadmium (Cd) through tobacco smoke has been identified as a major OA risk factor. There are no reports addressing the role of Cd in OA progression at the molecular level. Our findings revealed that Cd can promote the activation of metalloproteinases (MMP1, MMP3, MMP9 y MMP13), affecting the expression of COL2A1 and ACAN, and decreasing the presence of glycosaminoglycans and proteoglycans through an inflammatory response related to IL-1β y a IL-6, as well as oxidative by producing ROS like O2−• and H2O2. In conclusion, our findings suggest a cytotoxic role of Cd in the articular cartilage, which could affect OA development.

This study was designed to investigate whether genetic polymorphisms of the Wnt/β-catenin signaling pathway and its interactions are involved in the development of knee osteoarthritis (KOA). Patients with KOA (n = 131) and healthy individuals (n = 190) with different ancestry from two Mexican populations (Mexico City and Guadalajara City) were analyzed. Twenty-five SNPs from thirteen genes (WISP1, DKK1, SOST, FRZB, LRP1, LRP4, LRP5, LRP6, GSKB, ADAMTS5, GDF5, FMN2 and COL11A1) involved in the Wnt/β-catenin signaling pathway were genotyped. Genetic and allelic frequencies and gene–gene interactions were performed for this study. After adjusting for age, sex, BMI and admixture, significant associations were found for five SNPs in Mexico City: LRP6 rs12314259 (G/G genotype OR 0.22, P = 0.029; and G allele OR 0.48, P = 0.022), SOST rs851054 (C/T genotype OR 0.42, P = 0.027; and T allele OR 0.62, P = 0.026), FMN2 rs986690 (G/A genotype OR 0.42, P = 0.034; and A allele OR 0.50, P = 0.015), FRZB rs409238 (A/G genotype, OR 2.41, P = 0.022), and COL11A1 rs2615977 (A/C genotype OR 2.39, P = 0.024); no associations for Guadalajara City were found. With respect to gene–gene interactions, the pairwise interactions of WISP1–COL11A1, COL11A1–FRZB, FRZB–SOST and WISP1–FMN2 make it possible to visualize the synergistic or antagonistic effect of their genotypes or alleles in both populations. These results suggest that gene–gene interactions in the Wnt/β-catenin signaling pathway play a role in the etiology of KOA.

The anti-inflammatory and immunomodulatory effects of nanoparticles in several chronic diseases have been extensively researched. The aim of this review is to examine how nanoparticles modulate the inflammatory pathways that characterize the most prevalent forms of microcrystal-induced arthritis, including gout, pseudogout, and BCP-induced arthritis. The nanoparticles of chitosan-coated calcium phosphate, uricase, aceclofenac, and gold have been investigated in crystal-inducedarthritis. The most important results of the studies outlined in this review show that nanoparticles can inhibit the expression and the release of some pro-inflammatory mediators and proteolytic enzymes, and the activity of different transcriptional factors in vitro, as well as decrease the uric acid levels in several studies of in vitro and in vivo models of gout, which show interesting results in terms of decreasing the amount of crystals and tissue damage, respectively. In view of their multiple beneficial effects, nanoparticles can be considered a valuable therapy that contributes to the pharmacological treatment in crystalinduced arthritis.

Background: The presence of genetic variants in uric acid (UA) transporters can be associated with hyperuricemia, and therefore with an increased risk of monosodium urate (MSU) crystal precipitation. The inflammatory process triggered by these crystals leads to cartilage damage, which, in turn, could promote knee osteoarthritis (KOA). Objective: To determine whether genetic polymorphisms of the UA transporters and their interactions are associated with KOA. Materials and Methods: Two hundred forty-three unrelated Mexican-mestizo individuals were recruited for this case-control study. Ninety-three of them were KOA patients but without gout, and one hundred and fifty healthy individuals with no symptoms or signs of KOA were recruited as controls. Forty-one single-nucleotide polymorphisms (SNPs) involved in the UA transporters were genotyped with OpenArray technology in a QuantStudio 12K flex-System with both cases and controls. Results: After adjusting by age, gender, BMI, and ancestry, significant associations were found for eight SNPs: rs1260326 (GCKR), rs780093 (GCKR), rs17050272 (INHBB), rs1471633 (PDZK1), rs12129861 (PDZK1), rs7193778 (IGF1R), rs17786744 (STC1), and rs1106766 (R3HDM2). With respect to gene–gene interactions, the pairwise interactions of rs112129861 (PDZK1) and rs7193778 (IGF1R); rs17050272 (INHBB) and rs1106766 (R3HDM2); rs1106766 (R3HDM2) and rs780093 (GCKR); rs1260326 (GCKR) and rs17786744 (STC1); and rs17786744 (STC1) and rs1106766 (R3HDM2) make it possible to visualize the synergistic or antagonistic effect of their genotypes or alleles on KOA development. Conclusions: Our preliminary results show that the common gene variants related to UA transport are associated with KOA in the Mexican population. Further studies must be carried out to corroborate it.

Background HIF-1α is the main transcriptional regulator of cellular and developmental response to hypoxia, and also participates in the integration of the T cell receptor and cytokine receptor-mediated signals of CD4+ helper cells. Another transcription factor also involved in the immune responses is the AT-hook transcription factor (AKNA). Objectives To evaluate the allele and genotype frequencies of polymorphic sites of HIF1A and ANKA genes in primary Sjogren9s syndrome (pSS). Methods We included 110 patients with pSS and 141 ethnically matched healthy controls. Three HIF1A gene polymorphisms (Pro582Ser, Ala588Thr, and C191T) and two AKNA genes polymorphism (-1372C>A, and Pro624Leu) were genotyped using TaqMan probes in a Real-Time PCR instrument. Associations between pSS and genotypes, alleles and inheritance models of the SNPs of interest were evaluated by logistic regression adjusted by age and gender. Results Most of the patients were females (95.4%), median age 55 years and median disease duration of 7.8 years. The C/T genotype and the T allele of the HIF1APro582Ser polymorphism protected against pSS (OR=0.22; 95% CI=0.09–0.52; P A polymorphism A/A genotype was associated with an increased risk of pSS (OR=2.60; 95% CI=1.11–6.12; P=0.03). Parotid enlargement was associated with the HIF1A gene polymorphism (rs11549465), conferring protection for the C/T genotype vs. C/C (OR=0.22; 95% CI 0.05–0.90, P=0.03). The allele T of the same polymorphism was also associated with parotid enlargement (OR=0.24, 95% CI=0.65–0.95; P=0.04). We did not find any association with any other clinical or serological feature. Conclusions We identified HIF1APro582Ser T allele and C/T genotype as well as AKNA -1372C>A polymorphism A/A genotype as genetic factors associated with pSS. Further studies in other populations are needed to validate our findings and to shed some light on their functional implications. References Palazon A, Goldrath A, Nizet V, Johnson R. HIF transcription factors, inflammation and immunity. Immunity 2014; 41:518–28. Sims-Mourtada JC, Bruce S, McKeller MR, et al. The human AKNA gene expresses multiple transcripts and protein isoforms as a result of alternative promoter usage, splicing, and polyadenylation. DNA Cell Biol 2005;24:325–38. Disclosure of Interest None declared

Background The hallmark of osteoarthritis (OA) is the breakdown of articular cartilage. Articular cartilage is an avascular tissue, and this generates a hypoxic microenvironment. Hypoxia inducible factor-1α (HIF-1α) is the main transcriptional regulator of cellular and developmental response to hypoxia. Objectives The present study was designed to investigate whether genetic polymorphisms of the HIF-1α signaling pathway are involved in the development of knee OA. Methods A total of 243 unrelated Mexican-mestizo individuals comprising 93 knee OA patients and 150 healthy controls were recruited into the study. 42 genetic polymorphisms from 22 genes involved in the HIF-1α signaling pathway ( PIK3R1 , AKT2 , GSK3B , IL6 , AGER , HIF1A , EGLN1, VHL , HIF1AN , VEGFA , EPO , NOS2 , NOS3 , IGF1 , EGF , EDN1 , MMP1 , MMP3 , MMP13 , CA , COL2A1 , COL3A1 ) were genotyped in cases and controls using TaqMan-based allelic discrimination assays. Results After adjusting for age, sex and admixture, significant associations with knee OA were found for 7 SNPs in the case-control study. The following genotypes and alleles were associated with protection against OA: the CT genotype of the HIF1AN rs11190613 polymorphism (OR=0.44, 95% CI=0.19–1.0, P =0.05); the AA genotype of the VEGFA rs1570360 polymorphism (OR=0.14, 95% CI=0.02–0.69, P =0.016); the GT genotype and T allele of the VEGFA rs729761 polymorphism (OR=0.47, 95% CI=0.22–1.0, P =0.05; and OR=0.51, 95% CI=0.27–0.97, P =0.041, respectively); the GA genotype of the COL2A1 rs1793953 polymorphism (OR=0.40, 95% CI=0.20–0.79, P =0.008); and the GG genotype and G allele of the CKM rs4884 polymorphism (OR=0.34, 95% CI=0.14–0.84, P =0.019; and OR=0.51, 95% CI=0.32–0.82, respectively). Otherwise, the CT genotype of the COL3A1 rs2138533 polymorphism (OR=2.89, 95% CI=1.28–6.5, P =0.01); and the GA genotype of the IGF1 rs35767 polymorphism (OR=2.22, 95% CI=1.11–4.43, P =0.024) were associated with an increased risk of OA. However, by using of epistatic interactions between HIF-1α pathway polymorphisms, we found that the gene-gene interaction had a synergistic effect over the estimated OR-values (see table). Conclusions In this study we could observe that the gene-gene interaction of the HIF-1α signaling pathway highly increases the risk of developing OA, with the exception of COL2A1 and HIF1AN interaction which had a protective role against OA. Further studies are needed to validate this results. References Fernandez-Torres J, et al. Polymorphic variation of hypoxia inducible factor-1 A (HIF1A) gene might contribute to the development of knee osteoarthritis: a pilot study. BMC Musculoskelet Disord 2015; 16:218. Rodriguez-Fontanela C, et al. Assessment of osteoarthritis candidate genes in a meta-analysis of nine genome-wide association studies. Arthritis Rheumatol 2014; 66:940–949. Disclosure of Interest None declared

Background Gout is the most prevalent inflammatory arthropathy in young men, in which clinical manifestations are triggered by the deposits of monosodium urate (MSU) crystals in and around joints. From a clinical perspective, gouty attacks and tophaceous deposits have been associated to nodal osteoarthritis [1,2]. Objectives To determine the molecular mechanisms associating MSU crystal deposits with chondrocyte activation and changes in articular cartilage. Methods Primary cultures of synoviocytes were activated with MSU crystals for 24 h, the resulting supernatant was used as a supplementary conditioning basal medium (CBM) for 24 h chondrocyte growth. The expression level profile of cytokines (IL-6, IL-8) and nerve growth factor (NGF) in the supernatant was measured. Production of reactive oxygen and nitrogen species, such as O2●, H2O2, and NO●, was also measured intracellularly. Results Upon activation by MSU crystals, synoviocytes increased secretion of IL-6 and IL-8, as well as intracellular production of O2●, H2O2, and NO● in comparison to non-stimulated synoviocytes. Additionally, the chondrocytes incubated with CBM for 24 h increased significantly IL-6, IL-8, and NGF levels, as well as O2●, H2O2, and NO● levels when compared to non-stimulated chondrocytes. Secretion of these soluble mediators was even higher than the one observed in the synoviocytes and chondrocytes directly stimulated with MSU crystals. Conclusions Pro-inflammatory cytokine secretion induced by MSU crystals in synoviocytes triggers chondrocyte activation, intensifying the articular inflammatory state in gouty attacks. Furthermore, the increase in reactive species (particularly NO●, which inhibits proteoglycan synthesis) compromises the homeostasis of the extracellular matrix of the cartilage. Finally, overproduction of NGF and H2O2 by the chondrocyte functions a pain modulator during gout attacks. References Fam AG, et al. Gouty arthritis in nodal osteoarthritis. J Rheumatol 1996; 23:684–9. Roddy E, et al. Gout and nodal osteoarthritis: a case-control study. Rheumatology (Oxford) 2008; 47:732–3. Disclosure of Interest None declared

Recent studies have identified AKNA as a potential susceptibility gene for several inflammatory diseases. Here, we aimed to assess the potential association of AKNA polymorphisms with knee osteoarthritis (KOA) susceptibility in a Mexican population, following STREGA recommendations. From a DNA bank of 181 KOA patients and 140 healthy controls, two AKNA SNPs were genotyped using TaqMan probes. The association between KOA susceptibility and AKNA polymorphisms genotypes was evaluated by multivariated logistic regression analysis. Information regarding patients’ inflammatory biomarkers levels was obtained and their association with AKNA polymorphisms genotypes was assessed by lineal regression. We found a positive association with the recessive inheritance model of both AKNA polymorphisms (A/A genotype for both) and KOA susceptibility adjusting by age, body mass index (BMI), gender and place of birth (OR = 2.48, 95% CI 1.09–5.65 for rs10817595 polymorphism; and OR = 4.96; 95% CI 2.421–10.2 for rs3748176 polymorphism). Additionally these associations were also seen after stratifying patients by KOA severity and age. Furthermore the total leukocyte count was positively associated with rs10817595 AKNA polymorphism (β = 1.39; 95% CI 0.44–2.34) adjusting by age, BMI, gender, place of birth and disease severity. We suggest that regulatory and coding polymorphisms of the inflammatory modulator gene AKNA can influence the development of KOA. Further structural and functional studies might reveal the role of AKNA in OA and other rheumatic diseases.

Osteoarthritis is characterized by the presence of proinflammatory cytokines and reactive oxygen species. We aimed to clarify the role of prooxidant enzyme content at the synovial membrane level and how it correlates with the inflammatory process in patients with knee osteoarthritis (KOA). In synovial membranes from KOA patients and control group, we analyzed the protein content of prooxidant enzymes such as Nox2, xanthine oxidase (XO), and prolidase as well as the proinflammatory NALP3. Results show that protein content of prolidase and Nox2 increased 4.8- and 8.4-fold, respectively, and XO showed an increasing trend, while the NALP3 inflammasome increased 5.4-fold with respect to control group. Levels of prolidase and XO had a positive correlation between the levels of NALP3 and Nox2. By principal component analysis the protein expression pattern by study groups was evaluated. Three clusters were identified; protein expression patterns were higher for clusters two (prolidase) and three (XO and Nox2) between KOA patients and controls. Data suggest that prooxidant enzymes increase in synovial membrane of KOA patients and may contribute to the inflammatory state and degradation of the articular cartilage.

Context: Breast cancer (BC) risk has been differentially associated with urinary levels of some phthalate metabolites.Objective: To investigate whether PPARγ and PPARGC1B polymorphisms modulate these associations.Materials and methods: 208 BC cases were age-matched with 220 population controls. Phthalate metabolites were determined by HPLC-MS. PPARγ Pro12Ala (rs1801281) and PPARGC1B Ala203Pro (rs7732671) and Val279Ile (rs17572019) were genotyped.Results: The association between mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and BC risk was positively modified in PPARγ Pro12Ala C carriers. The association with mono-iso-butyl phthalate (MiBP) in PPARGC1B Ala203Pro G carriers was negatively modified.Conclusion. PPARγ and PPARGC1B polymorphisms modulate the association between phthalate exposure and BC risk.