Publications by authors named "Kari K Eklund"

61 Publications

Native and oxidised lipoproteins negatively regulate the serum amyloid A-induced NLRP3 inflammasome activation in human macrophages.

Clin Transl Immunology 2021 3;10(8):e1323. Epub 2021 Aug 3.

Helsinki Rheumatic Diseases and Inflammation Research Group Translational Immunology Research Program University of Helsinki Helsinki University Clinicum Helsinki Finland.

Objectives: The NLRP3 inflammasome plays a key role in arterial wall inflammation. In this study, we elucidated the role of serum lipoproteins in the regulation of NLRP3 inflammasome activation by serum amyloid A (SAA) and other inflammasome activators.

Methods: The effect of lipoproteins on the NLRP3 inflammasome activation was studied in primary human macrophages and THP-1 macrophages. The effect of oxidised low-density lipoprotein (LDL) was examined in an mouse model of SAA-induced peritoneal inflammation.

Results: Native and oxidised high-density lipoproteins (HDL) and LDLs inhibited the interaction of SAA with TLR4. HDL and LDL inhibited the secretion of interleukin (IL)-1β and tumor necrosis factor by reducing their transcription. Oxidised forms of these lipoproteins reduced the secretion of mature IL-1β also by inhibiting the activation of NLRP3 inflammasome induced by SAA, ATP, nigericin and monosodium urate crystals. Specifically, oxidised LDL was found to inhibit the inflammasome complex formation. No cellular uptake of lipoproteins was required, nor intact lipoprotein particles for the inhibitory effect, as the lipid fraction of oxidised LDL was sufficient. The inhibition of NLRP3 inflammasome activation by oxidised LDL was partially dependent on autophagy. Finally, oxidised LDL inhibited the SAA-induced peritoneal inflammation and IL-1β secretion .

Conclusions: These findings reveal that both HDL and LDL inhibit the proinflammatory activity of SAA and this inhibition is further enhanced by lipoprotein oxidation. Thus, lipoproteins possess major anti-inflammatory functions that hinder the NLRP3 inflammasome-activating signals, particularly those exerted by SAA, which has important implications in the pathogenesis of cardiovascular diseases.
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http://dx.doi.org/10.1002/cti2.1323DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8329955PMC
August 2021

Lifetime risk of rheumatoid arthritis-associated interstitial lung disease in mutation carriers.

Ann Rheum Dis 2021 Aug 3. Epub 2021 Aug 3.

Institute for Molecular Medicine Finland (FIMM), Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland

Objectives: To estimate lifetime risk of developing rheumatoid arthritis-associated interstitial lung disease (RA-ILD) with respect to the strongest known risk factor for pulmonary fibrosis, a promoter variant.

Methods: FinnGen is a collection of epidemiological cohorts and hospital biobank samples, integrating genetic data with up to 50 years of follow-up within nationwide registries in Finland. Patients with RA and ILD were identified from the Finnish national hospital discharge, medication reimbursement and cause-of-death registries. We estimated lifetime risks of ILD by age 80 with respect to the common variant rs35705950, a promoter variant.

Results: Out of 293 972 individuals, 1965 (0.7%) developed ILD by age 80. Among all individuals in the dataset, increased the risk of ILD with a HR of 2.44 (95% CI: 2.22 to 2.68). Out of 6869 patients diagnosed with RA, 247 (3.6%) developed ILD. In patients with RA, was a strong risk factor of ILD with a HR similar to the full dataset (HR: 2.27, 95% CI: 1.75 to 2.95). In patients with RA, lifetime risks of ILD were 16.8% (95% CI: 13.1% to 20.2%) for carriers and 6.1% (95% CI: 5.0% to 7.2%) for non-carriers. The difference between risks started to emerge at age 65, with a higher risk among men.

Conclusion: Our findings provide estimates of lifetime risk of RA-ILD based on mutation carrier status, demonstrating the potential of genomics for risk stratification of RA-ILD.
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http://dx.doi.org/10.1136/annrheumdis-2021-220698DOI Listing
August 2021

Histamine H Receptor Signaling Regulates the NLRP3 Inflammasome Activation in C2C12 Myocyte During Myogenic Differentiation.

Front Pharmacol 2021 31;12:599393. Epub 2021 May 31.

Urodynamic Center and Department of Urology, Institute of Clinical Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.

NLRP3 inflammasome has been implicated in impaired post-injury muscle healing and in muscle atrophy. Histamine receptors play an important role in inflammation, but the role of histamine H receptor (HR) in myocyte regeneration and in the regulation of NLRP3 inflammasome is not known. We studied the effects of HR signaling on C2C12 myocyte viability, apoptosis, and tumor necrosis factor alpha (TNFα)-induced NLRP3 inflammasome activation during striated myogenic differentiation at three time points (days 0, 3, and 6). Expression of , interleukin-1β (IL-1β), and myogenesis markers were determined. TNFα reduced overall viability of C2C12 cells, and exposure to TNFα induced apoptosis of cells at D6. Activation of HR had no effect on viability or apoptosis, whereas inhibition of HR increased TNFα-induced apoptosis. Stimulation of C2C12 cells with TNFα increased mRNA expression at D3 and D6. Moreover, TNFα reduced the expression of myogenesis markers MyoD1, Myogenin, and Myosin-2 at D3 and D6. HR attenuated TNFα-induced expression of and further inhibited the myogenesis marker expression; while HR -blockage enhanced the proinflammatory effects of TNFα and increased the myogenesis marker expression. TNFα-induced secretion of mature IL-1β was dependent on the activation of the NLRP3 inflammasome, as shown by the reduced secretion of mature IL-1β upon treatment of the cells with the small molecule inhibitor of the NLRP3 inflammasome (MCC950). The activation of HR reduced TNFα-induced IL-1β secretion, while the HR blockage had an opposite effect. In conclusion, the modulation of HR activity regulates the effects of TNFα on C2C12 myocyte differentiation and TNFα-induced activation of NLRP3 inflammasome. Thus, HR signaling may represent a novel target for limiting postinjury muscle inflammation and muscle atrophy.
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http://dx.doi.org/10.3389/fphar.2021.599393DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8202077PMC
May 2021

Hydroxychloroquine reduces interleukin-6 levels after myocardial infarction: The randomized, double-blind, placebo-controlled OXI pilot trial.

Int J Cardiol 2021 Aug 4;337:21-27. Epub 2021 May 4.

Heart and Lung Center, Helsinki University Hospital, Helsinki University, Helsinki, Finland. Electronic address:

Objectives: To determine the anti-inflammatory effect and safety of hydroxychloroquine after acute myocardial infarction.

Method: In this multicenter, double-blind, placebo-controlled OXI trial, 125 myocardial infarction patients were randomized at a median of 43 h after hospitalization to receive hydroxychloroquine 300 mg (n = 64) or placebo (n = 61) once daily for 6 months and, followed for an average of 32 months. Laboratory values were measured at baseline, 1, 6, and 12 months.

Results: The levels of interleukin-6 (IL-6) were comparable at baseline between study groups (p = 0.18). At six months, the IL-6 levels were lower in the hydroxychloroquine group (p = 0.042, between groups), and in the on-treatment analysis, the difference at this time point was even more pronounced (p = 0.019, respectively). The high-sensitivity C-reactive protein levels did not differ significantly between study groups at any time points. Eleven patients in the hydroxychloroquine group and four in the placebo group had adverse events leading to interruption or withdrawal of study medication, none of which was serious (p = 0.10, between groups).

Conclusions: In patients with myocardial infarction, hydroxychloroquine reduced IL-6 levels significantly more than did placebo without causing any clinically significant adverse events. A larger randomized clinical trial is warranted to prove the potential ability of hydroxychloroquine to reduce cardiovascular endpoints after myocardial infarction.
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http://dx.doi.org/10.1016/j.ijcard.2021.04.062DOI Listing
August 2021

Proportion of T follicular helper cells in peripheral blood of rheumatoid arthritis patients: a systematic review and meta-analysis.

Expert Rev Clin Immunol 2021 Jun 15;17(6):667-680. Epub 2021 Apr 15.

Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.

Alterations in the levels and activity of Tfh may lead to impaired immune tolerance and autoimmune diseases. The aim of this study was to investigate the proportion and types of Tfh cells in the peripheral blood (PB) of RA patients.Comprehensive databases were searched for studies evaluating the proportion of Tfh cells in the PB of patients with RA compared to healthy control (HCs).The proportion of Tfh cells in RA patients was significantly higher than in HCs (SMD 0.699, [0.513, 0.884], p < 0.0001). Furthermore, Tfh cells proportion in untreated-RA and early-RA patients was markedly greater than HCs, when comparisons done without considering the definition markers, and also when Tfh cells were defined by the specified definition markers. While the proportion of Tfh cells by all definitions was higher in active-RA compared to HCs, analysis of two definitions, CD4CXCR5 and CD4CXCR5ICOS, didn't show significant differences. Furthermore, higher proportion of Tfh cells defined by all definitions and a specified definition (CD4CXCR5PD-1) was observed when SRA compared to SRA patients.The results demonstrate that circulating Tfh are highly elevated in RA patients highlights its potential use as a biomarker and a target for RA therapy.
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http://dx.doi.org/10.1080/1744666X.2021.1915770DOI Listing
June 2021

Tumour cells express functional lymphatic endothelium-specific hyaluronan receptor in vitro and in vivo: Lymphatic mimicry promotes oral oncogenesis?

Oncogenesis 2021 Mar 5;10(3):23. Epub 2021 Mar 5.

Department of Oral and Maxillofacial Diseases, Clinicum, University of Helsinki, 00014, Helsinki, Finland.

Lymphatic metastasis represents the main route of tumour cell dissemination in oral squamous cell carcinoma (OSCC). Yet, there are no FDA-approved therapeutics targeting cancer-related lymphangiogenesis to date. The lymphatic vessel endothelial hyaluronic acid receptor 1 (LYVE-1), a specific lymphatic marker, is associated with poor survival in OSCC patients. In this study, we present a potential novel mechanism of lymphatic metastasis in OSCC-lymphatic mimicry (LM), a process whereby tumour cells form cytokeratin/LYVE-1, but podoplanin-negative, mosaic endothelial-like vessels. LM was detected in one-third (20/57; 35.08%) of randomly selected OSCC patients. The LM-positive patients had shorter overall survival (OS) compared to LM-negative group albeit not statistically significant. Highly-metastatic tumour cells formed distinct LM structures in vitro and in vivo. Importantly, the siRNA-mediated knockdown of LYVE-1 not only impaired tumour cell migration but also blunted their capacity to form LM-vessels in vitro and reduced tumour metastasis in vivo. Together, our findings uncovered, to our knowledge, a previously unknown expression and function of LYVE-1 in OSCC, whereby tumour cells could induce LM formation and promote lymphatic metastasis. Finally, more detailed studies on LM are warranted to better define this phenomenon in the future. These studies could benefit the development of targeted therapeutics for blocking tumour-related lymphangiogenesis.
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http://dx.doi.org/10.1038/s41389-021-00312-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7977063PMC
March 2021

Real-world 6 and 12-month Drug Retention, Remission and Response Rates of Secukinumab in 2,017 Psoriatic Arthritis patients in 13 European Countries.

Arthritis Care Res (Hoboken) 2021 Jan 18. Epub 2021 Jan 18.

Amsterdam University Medical Centres, location VU University medical centre, Department Rheumatology & Immunology Center (ARC), Amsterdam, the Netherlands.

Objective: There is a lack of real-life studies on IL-17 inhibition in psoriatic arthritis (PsA). We assessed real-life 6-/12-month effectiveness (i.e. retention, remission, low-disease-activity [LDA] and response rates) of the IL-17 inhibitor secukinumab in PsA patients overall, and across 1) number of prior biologic/targeted synthetic Disease-Modifying Anti-Rheumatic Drugs (b/tsDMARDs), 2) years since diagnosis, and 3) European registries.

Methods: Thirteen quality registries in rheumatology participating in the European Spondyloarthritis Research Collaboration Network provided longitudinal, observational data collected as part of routine care, for secondary use. Data were pooled and analysed with Kaplan-Meier plots, log-rank tests, Cox regression, and multiple linear and logistic regression analyses.

Results: A total of 2,017 PsA patients started treatment with secukinumab between 2015 and 2018. Overall secukinumab retention rates were 86%/76% after 6/12 months. Crude (LUNDEX adjusted) 6-month remission/LDA (LDA including remission) rates for DAPSA28, DAS28-CRP and SDAI were 13%/46% (11%/39%), 36%/55% (30%/46%) and 13%/56% (11%/47%), and 12-month rates 11%/46% (7%/31%), 39%/56% (26%/38%) and 16%/62% (10%/41%), respectively. CDAI remission/LDA rates were similar to the SDAI rates. Six-month ACR20/50/70 responses were 34%/19%/11% (29%/16%/9%); 12-month: 37%/21%/11% (24%/14%/7%). Secukinumab effectiveness was significantly better for b/tsDMARD naïve patients, similar across time since diagnosis (<2/2-4/>4 years) and varied significantly across the European registries.

Conclusion: In this large real-world study on secukinumab treatment in PsA, 6- and 12-month effectiveness was comparable to previous observational studies of TNFi. Retention, remission, LDA and response rates were significantly better for b/tsDMARD naïve patients, independent of time since diagnosis and varied significantly across the European countries.
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http://dx.doi.org/10.1002/acr.24560DOI Listing
January 2021

Novel Strain and Its Outer Membrane Vesicles Exert Immunoregulatory Effects .

Front Microbiol 2020 12;11:575455. Epub 2020 Nov 12.

Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.

, belonging to the order Bacteroidales, is a common, short-chain fatty acid producing member of the human intestinal microbiota. A decreased abundance of has been linked to different microbiota-associated diseases, such as non-alcoholic fatty liver disease, cystic fibrosis and inflammatory bowel disease (IBD). The type strain of has been genome-sequenced, but otherwise very little is known about this anaerobic bacterium. The species surfaces in many microbiota studies and, consequently, comprehension on its interactions with the host is needed. In this study, we isolated a novel strain of from a healthy fecal donor, identified it by genome sequencing and addressed its adhesive, epithelium reinforcing and immunoregulatory properties. Our results show that strain 57 is non-adherent to enterocytes or mucus, does not reinforce nor compromise Caco-2 monolayer integrity and most likely harbors penta-acylated, less endotoxic lipid A as part of its lipopolysaccharide (LPS) structure based on the lack of gene and results on low-level NF-κB activity. The studies by transmission electron microscopy revealed that produces outer membrane vesicles (OMV). cells, culture supernatant i.e., spent medium or OMVs did not induce interleukin-8 (IL-8) response in HT-29 enterocyte cells suggesting a very low proinflammatory capacity. On the contrary, the treatment of HT-29 cells with cells, spent medium or OMVs prior to exposure to LPS elicited a significant decrease in IL-8 production as compared to LPS treatment alone. Moreover, spent supernatant induced IL-10 production by immune cells, suggesting anti-inflammatory activity. Our findings indicate that and its effector molecules transported in OMVs could potentially exert anti-inflammatory action in the gut epithelium. Taken together, seems to be a commensal with a primarily beneficial interaction with the host.
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http://dx.doi.org/10.3389/fmicb.2020.575455DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7689251PMC
November 2020

Behçet disease (BD) and BD-like clinical phenotypes: NF-κB pathway in mucosal ulcerating diseases.

Scand J Immunol 2020 Nov 10;92(5):e12973. Epub 2020 Oct 10.

Rare Disease and Pediatric Research Centers, Hospital for Children and Adolescents and Adult Immunodeficiency Unit, Inflammation Center, University of Helsinki and HUS Helsinki University Hospital, Helsinki, Finland.

Behçet's disease (BD) is a heterogeneous multi-organ disorder in search of a unified pathophysiological theory and classification. The disease frequently has overlapping features resembling other disease clusters, such as vasculitides, spondyloarthritides and thrombophilias with similar genetic risk variants, namely HLA-B*51, ERAP1, IL-10, IL-23R. Many of the BD manifestations, such as unprovoked recurrent episodes of inflammation and increased expression of IL-1, IL-6 and TNFα, overlap with those of the hereditary monogenic autoinflammatory syndromes, positioning BD at the crossroads between autoimmune and autoinflammatory syndromes. BD-like disease associates with various inborn errors of immunity, including familial Mediterranean fever, conditions related to dysregulated NF-κB activation (eg TNFAIP3, NFKB1, OTULIN, RELA, IKBKG) and either constitutional trisomy 8 or acquired trisomy 8 in myelodysplastic syndromes. We review here the recent advances in the immunopathology of BD, BD-like diseases and the NF-κB pathway suggesting new elements in the elusive BD etiopathogenesis.
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http://dx.doi.org/10.1111/sji.12973DOI Listing
November 2020

Osteoarthritis and Toll-Like Receptors: When Innate Immunity Meets Chondrocyte Apoptosis.

Biology (Basel) 2020 Mar 30;9(4). Epub 2020 Mar 30.

Department of Rheumatology, Helsinki University and Helsinki University Hospital, 00014 Helsinki, Finland.

Osteoarthritis (OA) has long been viewed as a degenerative disease of cartilage, but accumulating evidence indicates that inflammation has a critical role in its pathogenesis. In particular, chondrocyte-mediated inflammatory responses triggered by the activation of innate immune receptors by alarmins (also known as danger signals) are thought to be involved. Thus, toll-like receptors (TLRs) and their signaling pathways are of particular interest. Recent reports suggest that among the TLR-induced innate immune responses, apoptosis is one of the critical events. Apoptosis is of particular importance, given that chondrocyte death is a dominant feature in OA. This review focuses on the role of TLR signaling in chondrocytes and the role of TLR activation in chondrocyte apoptosis. The functional relevance of TLR and TLR-triggered apoptosis in OA are discussed as well as their relevance as candidates for novel disease-modifying OA drugs (DMOADs).
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http://dx.doi.org/10.3390/biology9040065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235883PMC
March 2020

Tumor necrosis factor primes and metal particles activate the NLRP3 inflammasome in human primary macrophages.

Acta Biomater 2020 05 17;108:347-357. Epub 2020 Mar 17.

Department of Medicine, Clinicum, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 8, 00290 Helsinki, Finland; Translational Immunology Research Program, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland; ORTON Orthopaedic Hospital of the Orton Foundation, Tenholantie 10, 00280 Helsinki, Finland.

Aseptic loosening of total joint replacements is driven by a macrophage-mediated inflammatory reaction to implant-derived wear particles. Phagocytosis of implant debris has been suggested to activate the NLRP3 inflammasome leading to secretion of interleukin (IL)-1β. However, factors and molecular mechanisms driving the particle-induced inflammasome activation are yet to be fully elucidated. In this study, we investigated the inflammasome response of human primary macrophages to titanium, chromium, and molybdenum particles in vitro. We observed that particles alone were not sufficient to induce IL-1β secretion, but an additional priming signal-such as bacterial lipopolysaccharide (LPS)-was required to license the inflammasome activation. By using specific inhibitors against the inflammasome signaling pathway, we demonstrate that the particle-induced IL-1β secretion depended upon activation of the NLRP3 inflammasome. We further hypothesized that tumor necrosis factor (TNF) could substitute for LPS as a priming signal, and found that particle stimulation together with preceding TNF treatment resulted in inflammasome-dependent IL-1β production as well. Our results show that the NLRP3 inflammasome mediates wear particle responses in human primary macrophages, and its activation does not necessarily require the presence of bacterial components, but can be induced under aseptic conditions by TNF priming. STATEMENT OF SIGNIFICANCE: This study was conducted to elucidate the molecular mechanisms of metal particle-induced IL-1β secretion in human primary macrophages. Production of this pro-inflammatory mediator from wear particle-activated macrophages has been associated with increased bone loss around total joint replacements-a condition eventually requiring revision surgery. Our results confirm that together with a co-stimulatory priming signal, particles of common implant metals elicit macrophage-mediated IL-1β secretion through activation of the NLRP3 inflammasome pathway. We also present a concept of TNF priming in this context, demonstrating that the particle-related IL-1β secretion can take place in a truly sterile environment. Thus, inhibition of inflammasome signaling appears a means to prevent wear particle-induced inflammation and development of peri‑prosthetic osteolysis.
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http://dx.doi.org/10.1016/j.actbio.2020.03.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7729209PMC
May 2020

A Family With A20 Haploinsufficiency Presenting With Novel Clinical Manifestations and Challenges for Treatment.

J Clin Rheumatol 2020 Jan 21. Epub 2020 Jan 21.

Clinicum, Faculty of Medicine, University of Helsinki, Helsinki.

Background: Tumor necrosis factor α-induced protein 3 gene (TNFAIP3, also called A20) haploinsufficiency (HA20) leads to autoinflammation and autoimmunity. We have recently shown that a p.(Lys91*) mutation in A20 disrupts nuclear factor κB signaling, impairs protein-protein interactions of A20, and leads to inflammasome activation.

Methods: We now describe the clinical presentations and drug responses in a family with HA20 p.(Lys91*) mutation, consistent with our previously reported diverse immunological and functional findings.

Results: We report for the first time that inflammasome-mediated autoinflammatory lung reaction caused by HA20 can be treated with interleukin 1 antagonist anakinra. We also describe severe anemia related to HA20 successfully treated with mycophenolate. In addition, HA20 p.(Lys91*) was found to associate with autoimmune thyroid disease, juvenile idiopathic arthritis, psoriasis, liver disease, and immunodeficiency presenting with specific antibody deficiency and genital papillomatosis.

Conclusions: We conclude that HA20 may lead to combination of inflammation, immunodeficiency, and autoimmunity. The condition may present with variable and unpredictable symptoms with atypical treatment responses.
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http://dx.doi.org/10.1097/RHU.0000000000001268DOI Listing
January 2020

Impact of discordance between patient's and evaluator's global assessment on treatment outcomes in 14 868 patients with spondyloarthritis.

Rheumatology (Oxford) 2020 09;59(9):2455-2461

EuroSpA Coordinating Center, Copenhagen Center for Arthritis Research (COPECARE), Center for Rheumatology and Spine Diseases, Centre for Head and Orthopaedics, Rigshospitalet, Glostrup, Denmark.

Objectives: To assess the impact of 'patient's minus evaluator's global assessment of disease activity' (ΔPEG) at treatment initiation on retention and remission rates of TNF inhibitors (TNFi) in psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) patients across Europe.

Methods: Real-life data from PsA and axSpA patients starting their first TNFi from 11 countries in the European Spondyloarthritis Research Collaboration Network were pooled. Retention rates were compared by Kaplan-Meier analyses with log-rank test and by Cox regression, and remission rates by χ2 test and by logistic regression across quartiles of baseline ΔPEG, separately in female and male PsA and axSpA patients.

Results: We included 14 868 spondyloarthritis (5855 PsA, 9013 axSpA) patients. Baseline ΔPEG was negatively associated with 6/12/24-months' TNFi retention rates in female and male PsA and axSpA patients (P <0.001), with 6/12/24-months' BASDAI < 2 (P ≤0.002) and ASDAS < 1.3 (P ≤0.005) in axSpA patients, and with DAS28CRP(4)<2.6 (P ≤0.04) and DAPSA28 ≤ 4 (P ≤0.01), but not DAS28CRP(3)<2.6 (P ≥0.13) in PsA patients, with few exceptions on remission rates. Retention and remission rates were overall lower in female than male patients.

Conclusion: High baseline patient's compared with evaluator's global assessment was associated with lower 6/12/24-months' remission as well as retention rates of first TNFi in both PsA and axSpA patients. These results highlight the importance of discordance between patient's and evaluator's perspective on disease outcomes.
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http://dx.doi.org/10.1093/rheumatology/kez656DOI Listing
September 2020

Localized delivery of compounds into articular cartilage by using high-intensity focused ultrasound.

Sci Rep 2019 11 4;9(1):15937. Epub 2019 Nov 4.

Electronics Research Laboratory, Department of Physics, University of Helsinki, Helsinki, Finland.

Localized delivery of drugs into an osteoarthritic cartilaginous lesion does not yet exist, which limits pharmaceutical management of osteoarthritis (OA). High-intensity focused ultrasound (HIFU) provides a means to actuate matter from a distance in a non-destructive way. In this study, we aimed to deliver methylene blue locally into bovine articular cartilage in vitro. HIFU-treated samples (n = 10) were immersed in a methylene blue (MB) solution during sonication (f = 2.16 MHz, peak-positive-pressure = 3.5 MPa, mechanical index = 1.8, pulse repetition frequency = 3.0 kHz, cycles per burst: 50, duty cycle: 7%). Adjacent control 1 tissue (n = 10) was first pre-treated with HIFU followed by immersion into MB; adjacent control 2 tissue (n = 10) was immersed in MB without ultrasound exposure. The MB content was higher (p < 0.05) in HIFU-treated samples all the way to a depth of 600 µm from AC surface when compared to controls. Chondrocyte viability and RNA expression levels associated with cartilage degeneration were not different in HIFU-treated samples when compared to controls (p > 0.05). To conclude, HIFU delivers molecules into articular cartilage without major short-term concerns about safety. The method is a candidate for a future approach for managing OA.
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http://dx.doi.org/10.1038/s41598-019-52012-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6828772PMC
November 2019

Retention and response rates in 14 261 PsA patients starting TNF inhibitor treatment-results from 12 countries in EuroSpA.

Rheumatology (Oxford) 2020 07;59(7):1640-1650

Zitelabs Aps, Copenhagen.

Objective: To investigate TNF inhibitor (TNFi) retention and response rates in European biologic-naïve patients with PsA.

Methods: Prospectively collected data on PsA patients in routine care from 12 European registries were pooled. Heterogeneity in baseline characteristics between registries were explored (analysis of variance and pairwise comparison). Retention rates (Kaplan-Meier), clinical remission [28-joint count DAS (DAS28) <2.6; 28 joint Disease Activity index for Psoriatic Arthritis ⩽4] and ACR criteria for 20% improvement (ACR20)/ACR50/ACR70 were calculated, including LUNDEX adjustment.

Results: Overall, 14 261 patients with PsA initiated a first TNFi. Considerable heterogeneity of baseline characteristics between registries was observed. The median 12-month retention rate (95% CI) was 77% (76, 78%), ranging from 68 to 90% across registries. Overall, DAS28/28 joint Disease Activity index for Psoriatic Arthritis remission rates at 6 months were 56%/27% (LUNDEX: 45%/22%). Six-month ACR20/50/70 responses were 53%/38%/22%, respectively. In patients initiating a first TNFi after 2009 with registered fulfilment of ClASsification for Psoriatic ARthritis (CASPAR) criteria (n = 1980) or registered one or more swollen joint at baseline (n = 5803), the retention rates and response rates were similar to those found overall.

Conclusion: Approximately half of >14 000 patients with PsA who initiated first TNFi treatment in routine care were in DAS28 remission after 6 months, and three-quarters were still on the drug after 1 year. Considerable heterogeneity in baseline characteristics and outcomes across registries was observed. The feasibility of creating a large European database of PsA patients treated in routine care was demonstrated, offering unique opportunities for research with real-world data.
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http://dx.doi.org/10.1093/rheumatology/kez427DOI Listing
July 2020

Effect of Aging on the Macrophage Response to Titanium Particles.

J Orthop Res 2020 02 18;38(2):405-416. Epub 2019 Sep 18.

Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California.

Macrophage-mediated inflammatory reaction to implant wear particles drives bone loss around total joint replacements (TJR). Although most TJR recipients are elderly, studies linking wear particle-activated macrophages and peri-implant osteolysis have not taken into account the multiple effects that aging has on the innate immune system and, in particular, on macrophages. To address this, we compared the wear particle responses of bone marrow macrophages obtained from young (2-month) and aged (18-month) mice. Macrophages were polarized to M0, M1, or M2 phenotypes in vitro, challenged with titanium particles, and their inflammatory response was characterized at multiple time points by quantitative reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay. In addition, age-dependent changes in activation of transcription factor nuclear factor-κB were analyzed by a lentiviral vector-based luciferase reporter system. The particle stimulation experiment was further repeated using human primary macrophages isolated from blood donors of different ages. We found that the pro-inflammatory responses were generally higher in macrophages obtained from young mice, but differences between the age groups remained small and of uncertain biological significance. Noteworthily, M2 polarization effectively suppressed the particle-induced inflammation in both young and aged macrophages. These results suggest that aging of the innate immune system per se plays no significant role in the response of macrophages to titanium particles, whereas induction of M2 polarization appears a promising strategy to limit macrophage-mediated inflammation regardless of age. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:405-416, 2020.
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http://dx.doi.org/10.1002/jor.24461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6980287PMC
February 2020

Insights image for Forskolin attenuates the NLRP3 inflammasome activation and IL-1β secretion in human macrophages.

Pediatr Res 2019 12 21;86(6):785. Epub 2019 Aug 21.

Department of Medicine, Division of Rheumatology, Helsinki University Central Hospital, Haartmaninkatu 2, 000290, Helsinki, Finland.

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http://dx.doi.org/10.1038/s41390-019-0544-zDOI Listing
December 2019

Gain-of-function CEBPE mutation causes noncanonical autoinflammatory inflammasomopathy.

J Allergy Clin Immunol 2019 11 13;144(5):1364-1376. Epub 2019 Jun 13.

Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.

Background: CCAAT enhancer-binding protein epsilon (C/EBPε) is a transcription factor involved in late myeloid lineage differentiation and cellular function. The only previously known disorder linked to C/EBPε is autosomal recessive neutrophil-specific granule deficiency leading to severely impaired neutrophil function and early mortality.

Objective: The aim of this study was to molecularly characterize the effects of C/EBPε transcription factor Arg219His mutation identified in a Finnish family with previously genetically uncharacterized autoinflammatory and immunodeficiency syndrome.

Methods: Genetic analysis, proteomics, genome-wide transcriptional profiling by means of RNA-sequencing, chromatin immunoprecipitation (ChIP) sequencing, and assessment of the inflammasome function of primary macrophages were performed.

Results: Studies revealed a novel mechanism of genome-wide gain-of-function that dysregulated transcription of 464 genes. Mechanisms involved dysregulated noncanonical inflammasome activation caused by decreased association with transcriptional repressors, leading to increased chromatin occupancy and considerable changes in transcriptional activity, including increased expression of NLR family, pyrin domain-containing 3 protein (NLRP3) and constitutively expressed caspase-5 in macrophages.

Conclusion: We describe a novel autoinflammatory disease with defective neutrophil function caused by a homozygous Arg219His mutation in the transcription factor C/EBPε. Mutated C/EBPε acts as a regulator of both the inflammasome and interferome, and the Arg219His mutation causes the first human monogenic neomorphic and noncanonical inflammasomopathy/immunodeficiency. The mechanism, including widely dysregulated transcription, is likely not unique for C/EBPε. Similar multiomics approaches should also be used in studying other transcription factor-associated diseases.
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http://dx.doi.org/10.1016/j.jaci.2019.06.003DOI Listing
November 2019

Forskolin attenuates the NLRP3 inflammasome activation and IL-1β secretion in human macrophages.

Pediatr Res 2019 12 13;86(6):692-698. Epub 2019 May 13.

Pediatric Urodynamic Center and Department of Urology, Institute of Clinical Medicine, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China.

Background: The treatment of nucleotide-binding domain and leucine-rich repeat containing family, pyrin domain containing 3 (NLRP3) inflammasome-mediated pediatric inflammatory diseases is challenging. Here we studied whether cyclic adenosine monophosphate (cAMP) elevator forskolin could attenuate the nigericin-induced NLRP3-inflammasome activation and interleukin-1β (IL-1β) secretion in human macrophages.

Methods: The proteins and messenger RNA (mRNA) levels of inflammasome structural proteins and proinflammatory cytokines were measured in forskolin-stimulated nigericin-activated human THP-1 macrophages and primary macrophages.

Results: Activation of THP-1 macrophages with nigericin increased the mRNA expression of NLRP3, IL-1β, and caspase-1 (P < 0.01). Forskolin stimulation had no effect on the mRNA expression of NLRP3, caspase-1, or IL-1β in nigericin-activated cells (P > 0.05), while their protein levels were significantly decreased (P < 0.05). Forskolin-mediated increase in cytoplasmic cAMP in non-activated cells was attenuated in nigericin-activated macrophages (P < 0.05). Basal IL-1β secretion increased from 584 to 2696 pg/mL (P < 0.01) in nigericin-activated macrophages; forskolin dose-dependently reduced the nigericin-induced secretion of mature IL-1β (P < 0.01). Forskolin also inhibited the IL-1β secretion from activated human primary macrophages.

Conclusions: Forskolin inhibits the NLRP3 inflammasome activation and the secretion of mature IL-1β, in human macrophages. Forskolin and other cAMP elevator drugs could represent a novel approach for treatment of diseases associated with excessive inflammasome activation, like pediatric inflammatory diseases.
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http://dx.doi.org/10.1038/s41390-019-0418-4DOI Listing
December 2019

Human β-Defensin 2 Expression in Oral Epithelium: Potential Therapeutic Targets in Oral Lichen Planus.

Int J Mol Sci 2019 Apr 10;20(7). Epub 2019 Apr 10.

Translational Immunology Research Program, University of Helsinki, 00014 Helsinki, Finland.

Human β-defensin 2 (hBD-2) is a potent antimicrobial peptide that participates in defense against invading bacteria. We recently showed that bacterial components and histamine, through histamine H4 receptor (H4R), are involved in the pathogenesis of the potentially malignant lesion, oral lichen planus (OLP). However, the underlying mechanisms remain unknown. We, therefore, investigated the role of hBD2-histamine crosstalk signaling in promoting OLP pathology. Biopsies from OLP and oral tongue squamous cell carcinoma (OTSCC) patients, and healthy controls were used. Two OTSCC cell lines and normal human oral keratinocytes (HOKs) were used. HBD-2 and other targets were mapped by immunostaining and analyzed by ImageJ2 software. The highly sensitive droplet-digital PCR technology and qRT-PCR were utilized to study the clinically derived and in vitro samples, respectively. H4R was challenged with the specific agonist HST-10 and inverse agonist ST-1007. HBD-2 was highly induced in OLP lesions. In contrast, hBD2 expression was attenuated in OTSCC tissues, while very low levels of hBD-2 messenger RNA (mRNA) were observed in OTSCC cells. Together with tumor necrosis factor-α (TNF-α), histamine upregulated hBD-2 mRNA expression in HOKs. Activation of H4R seems to modulate the expression of epithelial hBD-2. These findings suggest the involvement of hBD-2 in the pathogenesis of OLP and may, thus, be harnessed for therapeutic interventions in OLP.
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http://dx.doi.org/10.3390/ijms20071780DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6479702PMC
April 2019

Impact of constitutional TET2 haploinsufficiency on molecular and clinical phenotype in humans.

Nat Commun 2019 03 19;10(1):1252. Epub 2019 Mar 19.

Department of Biomedicine, Experimental Hematology, University Hospital Basel and University of Basel, Basel, CH-4031, Switzerland.

Clonal hematopoiesis driven by somatic heterozygous TET2 loss is linked to malignant degeneration via consequent aberrant DNA methylation, and possibly to cardiovascular disease via increased cytokine and chemokine expression as reported in mice. Here, we discover a germline TET2 mutation in a lymphoma family. We observe neither unusual predisposition to atherosclerosis nor abnormal pro-inflammatory cytokine or chemokine expression. The latter finding is confirmed in cells from three additional unrelated TET2 germline mutation carriers. The TET2 defect elevates blood DNA methylation levels, especially at active enhancers and cell-type specific regulatory regions with binding sequences of master transcription factors involved in hematopoiesis. The regions display reduced methylation relative to all open chromatin regions in four DNMT3A germline mutation carriers, potentially due to TET2-mediated oxidation. Our findings provide insight into the interplay between epigenetic modulators and transcription factor activity in hematological neoplasia, but do not confirm the putative role of TET2 in atherosclerosis.
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http://dx.doi.org/10.1038/s41467-019-09198-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6424975PMC
March 2019

Haploinsufficiency of A20 impairs protein-protein interactome and leads into caspase-8-dependent enhancement of NLRP3 inflammasome activation.

RMD Open 2018 17;4(2):e000740. Epub 2018 Oct 17.

Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland.

Objectives: encodes A20 that negatively regulates nuclear factor kappa light chain enhancer of activated B cells (NF-κB), the major transcription factor coordinating inflammatory gene expression. polymorphisms have been linked with a spectrum of inflammatory and autoimmune diseases and, recently, loss-of-function mutations in A20 were found to cause a novel inflammatory disease 'haploinsufficiency of A20' (HA20). Here we describe a family with HA20 caused by a novel loss-of-function mutation and elucidate the upstream molecular mechanisms linking HA20 to dysregulation of NF-κB and the related inflammasome pathway.

Methods: NF-κB activation was studied in a mutation-expressing cell line using luciferase reporter assay. Physical and close-proximity protein-protein interactions of wild-type and p.(Lys91*) mutant A20 were analysed using mass spectrometry. NF-κB -dependent transcription, cytokine secretion and inflammasome activation were compared in immune cells of the HA20 patients and control subjects.

Results: The protein-protein interactome of p.(Lys91*) mutant A20 was severely impaired, including interactions with proteins regulating NF-κB activation, DNA repair responses and the NLR family pyrin domain containing 3 (NLRP3) inflammasome. The p.(Lys91*) mutant A20 failed to suppress NF-κB signalling, which led to increased NF-κB -dependent proinflammatory cytokine transcription. Functional experiments in the HA20 patients' immune cells uncovered a novel caspase-8-dependent mechanism of NLRP3 inflammasome hyperresponsiveness that mediated the excessive secretion of interleukin-1β and interleukin-18.

Conclusions: The current findings significantly deepen our understanding of the molecular mechanisms underlying HA20 and other diseases associated with reduced A20 expression or function, paving the way for future therapeutic targeting of the pathway.
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http://dx.doi.org/10.1136/rmdopen-2018-000740DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6203104PMC
October 2018

DEC2 Blocks the Effect of the ARNTL2/NPAS2 Dimer on the Expression of PER3 and DBP.

J Circadian Rhythms 2017 Aug 11;15. Epub 2017 Aug 11.

Department of Medicine, Clinicum, University of Helsinki and Helsinki University Hospital, Helsinki, FI.

The expression of clock genes and are disturbed in rheumatoid arthritis, an autoimmune disease with circadian variation of symptoms. We have shown that TNF is a potent inducer of these genes. We investigated the regulation of and by TNF and elucidated their effect on other clock gene expressions. Additionally, we studied the effect of and on and . Cultured primary human fibroblasts were stimulated with TNF and the effects on ARNTL2 and NPAS2 were studied with RT-qPCR and immunofluorescence staining. The role of NF-κB was analyzed using IKK-2 inhibitor IMD-0354. TNF promoted ARNTL2 localization into the nuclei. Similar to , the effects of TNF on and expressions were mediated via NF-κB. Cloned and were transfected into HEK293. The ARNTL2/NPAS2 dimer was a weaker inducer of and than ARNTL/NPAS2. ARNTL2 and NPAS2 are regulated by TNF via the same mechanism as DEC2. Compared to their paralogs they have unique effects on other circadian components. Our data suggest that these genes are responsible, at least in fibroblasts, for the accurate adaptation of circadian timekeeping in individual cells during inflammation.
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http://dx.doi.org/10.5334/jcr.149DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5624067PMC
August 2017

Functional analysis of synovial fluid from osteoarthritic knee and carpometacarpal joints unravels different molecular profiles.

Rheumatology (Oxford) 2019 05;58(5):897-907

Helsinki Institute for Life Science (HiLIFE) and Faculty of Medicine, Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, Finland.

Objective: In this work, we aimed to elucidate the molecular mechanisms driving primary OA. By studying the dynamics of protein expression in two different types of OA joints we searched for similarities and disparities to identify key molecular mechanisms driving OA.

Methods: For this purpose, human SF samples were obtained from CMC-I OA and knee joint of OA patients. SF samples were analysed by label-free quantitative liquid chromatography mass spectrometry. Disease-relevant proteins identified in proteomics studies, such as clusterin, paraoxonase/arylesterase 1 (PON1) and transthyretin were validated by enzyme-linked immunosorbent assays, and on the mRNA level by droplet digital PCR. Functional studies were performed in vitro using primary chondrocytes.

Results: Differential proteomic changes were observed in the concentration of 40 proteins including clusterin, PON1 and transthyretin. Immunoassay analyses of clusterin, PON1, transthyretin and other inflammatory cytokines confirmed significant differences in protein concentration in SF of CMC-I and knee OA patients, with primarily lower protein expression levels in CMC-I. Functional studies on chondrocytes unequivocally demonstrated that stimulation with SF obtained from knee OA, in contrast to CMC-I OA joint, caused a significant upregulation in pro-inflammatory response, cell death and hypertrophy.

Conclusion: This study demonstrates that differential expression of molecular players in SF from different OA joints evokes diverse effects on primary chondrocytes. The pathomolecular mechanisms of OA may significantly differ in various joints, a finding that brings a new dimension into the pathogenesis of primary OA.
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http://dx.doi.org/10.1093/rheumatology/key232DOI Listing
May 2019

Serum Epstein-Barr virus DNA, detected by droplet digital PCR, correlates with disease activity in patients with rheumatoid arthritis.

Clin Exp Rheumatol 2018 Sep-Oct;36(5):778-784. Epub 2018 Mar 20.

Department of Rheumatology, Helsinki University and Helsinki University Hospital, and ORTON Orthopaedic Hospital, Helsinki, Finland.

Objectives: To study the prevalence of asymptomatic activation of Epstein-Barr virus (EBV) in patients with rheumatoid arthritis (RA) and to analyse the correlation of serum EBV DNA with the disease activity.

Methods: The level of EBV DNA was determined by droplet digital PCR assay from the serum of 46 DMARD naive early RA (ERA) and 22 chronic RA (CRA)-patients at study onset. Follow-up samples from 31 ERA and 16 CRA patients were obtained after starting or modifying the anti-rheumatic treatment. EBV DNA was also measured from 33 healthy controls and 9 patients with adult onset Still's disease (AOSD). Disease activity was assessed by the disease activity score (DAS28).

Results: At baseline, EBV DNA was detected in the serum of 7 of the 46 ERA patients all of whom had moderate or high disease activity. In the follow-up samples, 11 of 31 patients were EBV DNA positive. At baseline EBV positive patients had significantly higher disease activity (p=0.036) and the concentration of EBV DNA correlated significantly with DAS28 (rs=0.333, p=0.024). EBV DNA was detected in 3 of 22 CRA patients at study onset and in 8 of 16 in the follow-up samples. At follow-up EBV positive patients had significantly higher DAS28 (p=0.027) and the concentration of EBV DNA correlated significantly with DAS28 (rs=0.724, p=0.002). Only one of the healthy controls and none of the AOSD patients were positive for EBV DNA.

Conclusions: Active RA is associated with a lytic EBV infection which may have a role in the pathogenesis of RA.
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January 2019

Histamine H receptor signalling in tongue cancer and its potential role in oral carcinogenesis - a short report.

Cell Oncol (Dordr) 2017 Dec 26;40(6):621-630. Epub 2017 Jun 26.

Department of Clinical Medicine, Clinicum, University of Helsinki, Helsinki, Finland.

Purpose: Recent reports indicate that histamine and its novel, high-affinity histamine H receptor (HR) play a role in carcinogenesis, and thus HR signalling has become a focus of increasing interest in the pathogenesis of many cancers. The roles of HR in oral epithelial dysplasia (OED) and oral tongue squamous cell carcinoma (OTSCC) are unknown. The purpose of this study was to assess HR expression in OTSCC patients and in OTSCC-derived cell lines.

Methods: Biopsies taken from OED, OTSCC and healthy oral mucosa were studied by immunostaining. Primary human oral keratinocytes (HOKs) and two OTSCC-derived cell lines (HSC-3 and SCC-25) were used for the in vitro studies. Quantitative real-time PCR was used to measure oncogene expression in the stimulated HOKs.

Results: We found that HR-immunoreactivity was significantly reduced in the OED and OTSCC samples, especially in the samples with higher histopathological grades and noticeably increased mast cell counts. The presence of HR in HSC-3 cells had clearly waned, in contrast to the HOKs. Gene expression data indicated that histamine-relevant inflammatory and environmental elements may participate in the regulation of oncogenes.

Conclusions: Our results suggest an association between HR and oral carcinogenesis. Furthermore, our findings raise a potential implication of histamine-mediated factors in the regulation of oncogenes, possibly via mast cells, as crucial components of the tumor microenvironment. The identification of new elements that govern oral cancer development is highly relevant for the development of novel therapeutic approaches in OTSCC.
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http://dx.doi.org/10.1007/s13402-017-0336-6DOI Listing
December 2017

Laser-ultrasonic delivery of agents into articular cartilage.

Sci Rep 2017 06 21;7(1):3991. Epub 2017 Jun 21.

Electronics Research Laboratory, Department of Physics, University of Helsinki, Helsinki, Finland.

Research is ongoing to develop drug therapies to manage osteoarthritis (OA) and articular cartilage (AC) injuries. However, means to deliver drug to localized AC lesions are highly limited and not clinically available. This study investigates the capability of laser ultrasound (laser-induced plasma sound source) to deliver agents (methylene blue, MB, in PBS) into bovine AC. Treatment samples (n = 10) were immersed in MB solution simultaneously with LU exposure, while adjacent control 1 tissue (n = 10) was pre-treated with LU followed by immersion in MB and adjacent control 2 tissue (n = 10) was only immersed in MB. AC exposed (n = 22) or not exposed (n = 27) to LU were characterized for anomalies in structure, composition, viability or RNA expression. Optically detected MB content was significantly (p < 0.01) higher in treatment samples up to a depth of 500 µm from AC surface as compared to controls. No major unwanted short-term effects on AC structure, proteoglycan or collagen contents, chondrocyte viability or RNA expression levels were detected. In conclusion, LU can deliver agents into AC without major short-term concerns on safety. LU could reveal new strategies for the development of localized drug therapies in AC.
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http://dx.doi.org/10.1038/s41598-017-04293-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5479804PMC
June 2017

Prevention of Biomaterial Infection by Pre-Operative Incubation with Human Cells.

Surg Infect (Larchmt) 2017 Apr 7;18(3):336-344. Epub 2017 Mar 7.

1 Department of Otorhinolaryngology - Head and Neck Surgery, Helsinki University Hospital and University of Helsinki , Helsinki, Finland .

Background: Cells of tissues and biofilm forming bacteria compete for the living space on the surface of an implant. We hypothesized the incubation of the implant (titanium, polydimethylsiloxane, and polystyrene surface) with human cells before implantation as a strategy to prevent bacterial adhesion and biofilm formation.

Methods: After 24 hours of incubation with human osteogenic sarcoma SaOS-2 cells (1 × 10 cells/mL), the materials were incubated for 4.5 hours or two days with Staphylococcus aureus in serial 1:10 dilutions of 10 colony-forming units/mL. The bacterial adherence and biofilm biomass on materials pre-incubated with SaOS-2 cells were compared with our previous results on materials incubated only with bacteria or in simultaneous co-culture of SaOS-2 cells and S. aureus. Fluorescent microscopy and crystal violet stain were used. The number of viable SaOS-2 and bacterial cells present was tested using colorimetric methods (MTT, LDH) and drop plate method, respectively.

Results: The pre-treatment with human cells was associated with a reduction of bacterial colonization of the biomaterial at 4.5 hours and 48 hours compared with the non-pre-treated materials. The presence of bacteria decreased the number of viable human cells on all materials. ( Supplementary Fig. 1 ; see online supplementary materials at www.liebertpub.com/sur ).

Conclusions: These results suggest that the pre-operative incubation of prostheses with host cells could prevent infection of biomaterials.
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http://dx.doi.org/10.1089/sur.2016.263DOI Listing
April 2017

Global Characterization of Protein Secretion from Human Macrophages Following Non-canonical Caspase-4/5 Inflammasome Activation.

Mol Cell Proteomics 2017 04 14;16(4 suppl 1):S187-S199. Epub 2017 Feb 14.

From the ‡Rheumatology, University of Helsinki and Helsinki University Hospital, 00290 Helsinki, Finland.

Gram-negative bacteria are associated with a wide spectrum of infectious diseases in humans. Inflammasomes are cytosolic protein complexes that are assembled when the cell encounters pathogens or other harmful agents. The non-canonical caspase-4/5 inflammasome is activated by Gram-negative bacteria-derived lipopolysaccharide (LPS) and by endogenous oxidized phospholipids. Protein secretion is a critical component of the innate immune response. Here, we have used label-free quantitative proteomics to characterize global protein secretion in response to non-canonical inflammasome activation upon intracellular LPS recognition in human primary macrophages. Before proteomics, the total secretome was separated into two fractions, enriched extracellular vesicle (EV) fraction and rest-secretome (RS) fraction using size-exclusion centrifugation. We identified 1048 proteins from the EV fraction and 1223 proteins from the RS fraction. From these, 640 were identified from both fractions suggesting that the non-canonical inflammasome activates multiple, partly overlapping protein secretion pathways. We identified several secreted proteins that have a critical role in host response against severe Gram-negative bacterial infection. The soluble secretome (RS fraction) was highly enriched with inflammation-associated proteins upon intracellular LPS recognition. Several ribosomal proteins were highly abundant in the EV fraction upon infection, and our data strongly suggest that secretion of translational machinery and concomitant inhibition of translation are important parts of host response against Gram-negative bacteria sensing caspase-4/5 inflammasome. Intracellular recognition of LPS resulted in the secretion of two metalloproteinases, isintegrin nd etalloproteinase domain-containing protein 10 (ADAM10) and MMP14, in the enriched EV fraction. ADAM10 release was associated with the secretion of TNF, a key inflammatory cytokine, and M-CSF, an important growth factor for myeloid cells probably through ADAM10-dependent membrane shedding of these cytokines. Caspase-4/5 inflammasome activation also resulted in secretion of danger-associated molecules S100A8 and prothymosin-α in the enriched EV fraction. Both S100A8 and prothymosin-α are ligands for toll-like receptor 4 recognizing extracellular LPS, and they may contribute to endotoxic shock during non-canonical inflammasome activation.
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http://dx.doi.org/10.1074/mcp.M116.064840DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5393394PMC
April 2017

Congestive heart failure: more common as well as an important cardiovascular outcome: reply.

Eur Heart J Cardiovasc Pharmacother 2017 04;3(2):99

Heart and Lung Center, University of Helsinki and Helsinki University Hospital, HUS, 00029, Finland, PL 340.

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http://dx.doi.org/10.1093/ehjcvp/pvw050DOI Listing
April 2017
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