[Low expression of Tlr-1, -2, -4 a il-2, -2r, -10, -10r and TgFb1 in pseudosynovial tissue collected at revision total knee arthroplasty for aseptic loosening]. / Nízká exprese Tlr-1, -2, -4 a il-2, -2r, -10, -10r, TgFb1 v pseudosynoviální tkáni odebrané pri reoperaci asepticky uvolnené totální endoprotézy kycle a kolena.

PURPOSE OF THE STUDY: Aseptic loosening (AL) and periprosthetic osteolysis (PPOL) in total hip (THA) and knee (TKA) arthroplasty are linked to an inflammatory process initiated by wear debris released from artificial joints. There is still limited information about the contribution of Toll-like receptors (TLRs) and distinct regulatory cytokines to AL/PPOL in both joints. METHODS: In this study, we investigated mRNA expression of TLR-1,-2,-4 and cytokines/receptors (IL-2,-2R,-10,-10R, TGFb1) in pseudosynovial tissue obtained from 55 patients with aseptically failed THAs/TKAs and 37 control patients with hip/knee primary osteoarthritis (OA) using quantitative RT-PCR. Immunohistochemical staining was used to detect the corresponding proteins. Non-parametric Kruskal-Wallis and Mann-Whitney tests were used to determine differences between the patient groups. RESULTS: When comparing expression profiles between patients with aseptically failed THA and TKA, higher amounts of TLR-1,- 2,-4 and IL-2R mRNA transcripts were detected in THA patients. The mRNA expression of studied molecules (TLR-1,-2,-4, IL-2, IL-10, IL-2R, IL-10R, TGFb1) did not differ between THA and OA hip tissues. Lower mRNA expression of TLR-1,-2,- 4, IL-10, and IL-10R was detected in TKA when compared to control knee OA. Similar mRNA profiles of IL-2, IL-2R, and TGFb1 were observed in TKA and knee OA. Using immunohistochemistry, we detected low expression of TLR-1 protein in failed THA/TKA, whereas TLR-2 protein levels were higher in TKA/THA patients than in OA controls. High individual variability in TLR-4 protein levels was detected among patients with aseptically loosened THA and TKA. IL-10 protein levels were similar in THA and TKA patient subgroups and control subjects, whereas IL-10R protein level was higher in failed TKAs and OA controls than in THAs. No difference in IL-2 protein levels was detected between patients with THA/TKA and those with OA. DISCUSSION: Our data indicate close similarity between the expression patterns in aseptically failed THA and TKA. However, certain differences were observed which also suggest unique pathways associated with the end-stage of aseptic loosening in THA and TKA. For instance, differences in the size, shape and load of polyethylene particles between THA and TKA could play some role. The composition of THA and TKA and differences in terms of mechanical forces might also be involved. CONCLUSIONS: This is the fist study comparing the gene expression profile of a particular set of innate immunity regulatory molecules between tissues from aseptically failed THA and TKA. Low expression of TLR-1,-2,-4 and cytokines/receptors (IL-2, IL-2R, IL-10, IL-10R, and TGFb1) was observed in pseudosynovial tissues obtained from aseptically failed THAs and TKAs. Higher amount of TLR transcripts was detected in THA as compared to TKA. These findings indicate certain differences in the mechanism of aseptic loosening occurring at the site of THA and TKA. Further research is warranted.

Comparison of periprosthetic tissues in knee and hip joints: differential expression of CCL3 and DC-STAMP in total knee and hip arthroplasty and similar cytokine profiles in primary knee and hip osteoarthritis.

OBJECTIVE: To identify expression profiles (EP) associated with aseptic loosening of total knee arthroplasty (TKA) and to compare them with EP observed in total hip arthroplasty (THA), and primary knee and hip osteoarthritis (OA). DESIGN: Gene EP of TNF, IL-6, IL-8, CHIT1, BMP4, CCL3, CCL18, MMP9, RANKL, OPG, DC-STAMP and SOCS3 were assessed using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) on tissues retrieved from patients with aseptically failed TKA (n = 21), THA (n = 41) and primary knee (n = 20) and hip (n = 17) OA. Immunohistochemistry was applied to localize the proteins. RESULTS: When compared to knee OA, the pseudosynovial tissue in TKA exhibit (1) elevation of alternative macrophage activation marker (CHIT1), chemokine (IL-8), and a proteolytic enzyme (MMP9); (2) downregulation of pro-inflammatory cytokine (TNF), osteoclastic regulator (OPG) and a stimulator of bone formation (BMP4); (3) no difference in IL-6, CCL3, CCL18, RANKL, DC-STAMP and SOCS3. The EP in TKA differed from EP in aseptically failed THA by lower CCL3 and DC-STAMP mRNA and protein expression. EP of all studied inflammatory and osteoclastogenic molecules were similar in knee and hip OA. CONCLUSIONS: Comparing to OA, aseptic loosening of TKA is associated with upregulated expression of CHIT1, IL-8 and MMP9, dysregulated RANKL:OPG ratio and low levels of inflammatory cytokines. Similar cytokine profiles were associated with primary knee and hip OA. Further research is required to explain the differences in CCL3 and DC-STAMP expression between failed TKA and THA.

Colchicine modulates expression of pro-inflammatory genes in neutrophils from patients with familial Mediterranean fever and healthy subjects.

Colchicine (Col) is a microtubule depolymerizing drug, widely used for treatment of familial Mediterranean fever (FMF). Mechanisms by which Col exerts its beneficial effects are not yet completely understood, especially with respect to gene expression in polymorphonuclear neutrophils (PMNs), the main effector cells in acute inflammatory attacks of FMF. This study was, therefore, designed to elucidate possible modulatory effect of Col on expression of inflammation-related genes in circulating PMNs from 16 FMF patients in the remission period and 11 healthy subjects. In vitro effect of Col exposure (1 microg/ml) on expression of 8 selected genes was examined using quantitative real-time RT-PCR. Col up-regulated expression of IL-8 and IL-1beta genes in FMF (13-fold and 2.7-fold, p less than 0.05, respectively) and healthy (3-fold and 6.5-fold, p less than 0.05, respectively) PMNs, and down-regulated caspase-1 in FMF neutrophils (3-fold, p less than 0.05). In FMF PMNs treated with Col mRNAs of IL-8 (51-fold, p less than 0.01) and c-FOS (7-fold, p less than 0.05) transcripts were elevated compared to those from healthy subjects. By contrast, caspase-1 mRNA was decreased in FMF neutrophils compared to healthy cells (1.6-fold, p less than 0.05). Hereby, we provide evidence that, at least in vitro, Col displays pro-inflammatory potential in respect to IL-1beta and IL-8 genes. At the same time, our findings implicate suppression of caspase-1 expression by Col as a potential mechanism for its effects in FMF treatment.

MicroRNAs: Emerging Regulators of Immune-Mediated Diseases.

MicroRNAs (miRNAs) represent the most abundant class of regulators of gene expression in humans: they regulate one-third of human protein-coding genes. These small noncoding ∼22-nucleotides (nt)-long RNAs originate by multistep process from miRNA genes localized in the genomic DNA. To date, more than 1420 miRNAs have been identified in humans (miRBase v17). The main mechanism of miRNA action is the posttranscriptional regulation via RNA interference with their target mRNAs. The majority of target mRNAs (more than 80%) undergo degradation after recognition by complementary miRNA; the translational inhibition with little or no influence on mRNA levels has been also reported. Each miRNA may suppress multiple mRNA targets (average ∼200), and at the same time, one mRNA can be targeted by many miRNAs enabling to control a spectrum wide range of cellular processes. Recently, the role of miRNAs in the development of immune cells and the maintenance of immune system homeostasis gained attention, and the involvement of miRNAs in the pathogenesis of several immune system diseases has emerged. This review focuses on the role of miRNAs in autoimmune disorders (systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease and psoriasis), inflammatory pathologies of distinct organ (atherosclerosis, osteoarthritis and atopic eczema) and/or systemic locations such as allergy. The role of miRNAs, their predicted and known mRNA targets and description of their actions in physiological immune reactions and in the pathological processes ongoing in immune-mediated human disorders will be discussed. Finally, miRNA-based diagnostics and therapeutic potentials will be highlighted.

T-helper cell type-1 transcription factor T-bet is upregulated in pulmonary sarcoidosis.

Upregulation of genes for interferon (IFN)-γ and CXC chemokine receptor (CXCR)3 expression, two crucial molecules in sarcoid inflammation and granuloma formation, is directly controlled by the T-helper (Th)1 transcription factor T-bet (T-box, expressed in T-cells). However, there is no information on T-bet expression in sarcoidosis or its relationship with "sarcoidosis-associated" genes. Therefore, we investigated expression of T-bet mRNA and, in parallel, a spectrum of genes known to be involved in sarcoidosis pathogenesis. Transcripts were determined in bronchoalveolar lavage (BAL) cells from 62 sarcoidosis patients and 25 controls by quantitative RT-PCR; T-bet protein was localised by immunohistochemistry. Patient's BAL cells expressed higher mRNA T-bet levels than those of controls (mean ± sd fold change 3.64 ± 1.72; p = 0.00006). T-bet mRNA expression did not vary between clinical phenotypes as assessed by chest radiography stage, presence/absence of Löfgren's syndrome, extrapulmonary/pulmonary involvement or progressing/remitting disease (p > 0.05). T-bet mRNA expression correlated with expression of IFN-γ, CC chemokine ligand 5, CXC chemokine ligand (CXC)10, interleukin (IL)-2 receptor/IL-15 receptor ß, CXCR3 and CXCR6 (p < 0.01). T-bet protein was localised to alveolar macrophages and lymphocytes, tissue multinucleated giant cells, macrophages and lymphocytes. In pulmonary sarcoidosis, T-bet upregulation is associated with changes in expression of IFN-γ, CXCR3 and chemokines/receptors involved in the pathogenesis of sarcoidosis, which suggests a role for T-bet in this Th1 disease, including modulation of some sarcoidosis-associated genes.