Cytokines and MMP-9 Levels in rheumatoid arthritis and osteoarthritis patients with persistent parvovirus B19, HHV-6 and HHV-7 Infection

Funding Information: This work was supported in part by the grant Nr. 09.0112 from Latvian Council of Science and by the National Research Programme in Biomedicine 2014–2017. Publisher Copyright: © 2019 Anda Kadiša et al., published by Sciendo 2019. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes erosive changes and ankylosis of joints and may cause internal injuries. Osteoarthritis (OA) is a degenerative process of the articular cartilage. However, inflammatory mediators may play a pivotal role in the initiation and perpetuation of the OA process. It is necessary to continue to study possible factors that may promote the development of the disease. The goal of this study was to evaluate the frequency and activity stage of parvovirus B19 (B19V) and persistent human herpes virus (HHV)-6 and HHV-7 infection in RA and OA patients, and healthy persons, in relation to cytokine levels and presence or absence of viral infections. RA patients with active B19V infection had the highest levels of tumour necrosis factor alpha (TNF-α), which may contribute to the development of RA. In the case of OA, the TNF-α level was higher in patients with active persistent B19V infection, suggesting that B19V reactivation affects also OA. Interleukin (IL)-6, IL-10 and metalloproteinase (MMP)-9 levels were higher in RA patients with latent HHV-6/-7 infection in comparison with active HHV-6/-7 infection, whereas in OA patients levels of all studied cytokines were very variable, ranging from low to high but without significant differences. This suggests that also latent HHV-6 and -7 viral infections can promote development of RA.Peer reviewe

The Sphingosine-1-Phosphate (S1P) Lysophospholipid Receptor S1P3 Regulates MAdCAM-1+ Endothelial Cells in Splenic Marginal Sinus Organization

Marginal zones (MZs) are microdomains in the spleen that contain various types of immune cells, including MZ B cells, MOMA1+ metallophilic macrophages, and mucosal addressin cell adhesion molecule 1 (MAdCAM-1)+ endothelial cells. MAdCAM-1+ and MOMA1+ cells line the sinus, that separates MZs from splenic follicles. Here we show that a receptor for the lysophospholipid sphingosine-1-phosphate (S1P), S1P3, is required for normal numbers of splenic immature and MZ B cells, and for S1P-induced chemotaxis of MZ B cells. S1P3 is also essential for proper alignment of MOMA1+ macrophages and MAdCAM-1+ endothelial cells along the marginal sinus. The lack of cohesion of the marginal sinus in S1P3−/− mice affects MZ B cell functions, as wild-type (WT) MZ B cells migrate more into S1P3−/− follicles than into WT follicles after treatment with lipopolysaccharide. Additionally, short-term homing experiments demonstrate that WT MZ B cells home to the S1P3−/− spleen in increased numbers, suggesting a role for the marginal sinus in regulating MZ B cells numbers. Moreover, S1P3−/− mice are defective in mounting immune responses to thymus-independent antigen type 2 due to defects in radiation-resistant cells in the spleen. These data identify lysophospholipids and the S1P3 receptor as essential regulators of the MZ sinus and its role as a barrier to the follicle

Deficiency of annexins A5 and A6 induces complex changes in the transcriptome of growth plate cartilage but does not inhibit the induction of mineralization

Initiation of mineralization during endochondral ossification is a multistep process and has been assumed to correlate with specific interactions of annexins A5 and A6 and collagens. However, skeletal development appears to be normal in mice deficient for either A5 or A6, and the highly conserved structures led to the assumption that A5 and A6 may fulfill redundant functions. We have now generated mice deficient of both proteins. These mice were viable and fertile and showed no obvious abnormalities. Assessment of skeletal elements using histologic, ultrastructural, and peripheral quantitative computed tomographic methods revealed that mineralization and development of the skeleton were not significantly affected in mutant mice. Otherwise, global gene expression analysis showed subtle changes at the transcriptome level of genes involved in cell growth and intermediate metabolism. These results indicate that annexins A5 and A6 may not represent the essential annexins that promote mineralization in vivo

Presence of Human Bocavirus 1 in Hospitalised Children with Acute Respiratory Tract Infections in Latvia and Lithuania

Funding Information: This study was supported by Republic of China (Taiwan)-Republic of Latvia-Republic of Lithuania scientific collaboration project, "Establishing of the framework to track molecular epidemiology of Parvoviruses and to correlate sequence variability with different clinical manifestations" (Research Council of Latvia Nr. gr. 6-25/2012/0026, Research Council of Lithuania TAPLLT02/201) and by project Nr. RSU ZP 17/2013 "Epidemiology, pathogenicity of human Bocavirus (HBoV) species and possible association with lower respiratory tract illnesses and acute gastroenteritis in children". We are grateful to Rita Nikitenkiene and Irina Maksimova for technical help. Publisher Copyright: © 2016 by Zaiga Nora-Krūkle. Copyright: Copyright 2016 Elsevier B.V., All rights reserved.Human bocavirus 1 (HBoV1) is a parvovirus recently found to be a possible aetiologic agent of acute respiratory disease in children. We conducted the first clinical and molecular study on this virus in Latvia (LV) and Lithuania (LT). The aim of the study was to determine the occurrence of HBoV1 in respiratory tract samples taken from hospitalised children with acute respiratory tract infections in LV and LT. In total 186 children with age one to 50 months, and who fulfilled criteria of acute respiratory tract infection, including lower respiratory tract infections, with or without fever, were included in this study. A nasopharyngeal aspirate was obtained from each patient on admission. DNA was isolated and polimerase chain reaction (PCR) performed targeting the HBoV1 NS1sequence. HBoV1 positive samples were sequenced and phylogenetic analysis was performed. HBoV1 sequence was detected in 42 (32%) of 130 LV and in 8 (14%) of 56 LT samples. In LV the majority of patients with HBoV1 infection were observed in February while in LT in October. The phylogenetic tree for HBoV1 indicated that isolates of HBoV1 cluster closely and include almost all of the isolates in this study. HBoV1 is common in Latvia and Lithuania and might be a significant pathogen that contributes to acute respiratory tract infections in children.Peer reviewe

Performance of new gellan gum hydrogels combined with human articular chondrocytes for cartilage regeneration when subcutaneously implanted in nude mice

Gellan gum is a polysaccharide that has been recently proposed by our group for cartilage tissueengineering applications. It is commonly used in the food and pharmaceutical industry and has the ability to form stable gels without the use of harsh reagents. Gellan gum can function as a minimally invasive injectable system, gelling inside the body in situ under physiological conditions and efficiently adapting to the defect site. In this work, gellan gum hydrogels were combined with human articular chondrocytes (hACs) and were subcutaneously implanted in nude mice for 4 weeks. The implants were collected for histological (haematoxylin and eosin and Alcian blue staining), biochemical [dimethylmethylene blue (GAG) assay], molecular (real-time PCR analyses for collagen types I, II and X, aggrecan) and immunological analyses (immunolocalization of collagen types I and II). The results showed a homogeneous cell distribution and the typical round-shaped morphology of the chondrocytes within the matrix upon implantation. Proteoglycans synthesis was detected by Alcian blue staining and a statistically significant increase of proteoglycans content was measured with the GAG assay quantified from 1 to 4 weeks of implantation. Real-time PCR analyses showed a statistically significant upregulation of collagen type II and aggrecan levels in the same periods. The immunological assays suggest deposition of collagen type II along with some collagen type I. The overall data shows that gellan gum hydrogels adequately support the growth and ECM deposition of human articular chondrocytes when implanted subcutaneously in nude mice.J. T. Oliveira would like to acknowledge the Portuguese Foundation for Science and Technology (FCT) for his grant (SFP,H/BD17135/2004). The authors would like to thank the patients at Hospital de S. Marcos, Braga, Portugal, for the donation of the biological samples and the medical staff for their help and support. The authors would also like to thank the Institute for Health and Life Sciences (ICVS), University of Minho, Braga, Portugal, for allowing the use of their research facilities. This work was carried out under the scope of European NoE EXPERTISSUES (Project No. NMP3-CT-2004-500283) and partially supported by the European Project HIPPOCRATES (No. STRP 505758-1)

Disorganization of the splenic microanatomy in ageing mice

The precise mechanisms responsible for immunosenescence still remain to be determined, however, considering the evidence that disruption of the organization of primary and secondary lymphoid organs results in immunodeficiency, we propose that this could be involved in the decline of immune responses with age. Therefore, we investigated the integrity of the splenic microarchitecture in mice of increasing age and its reorganization following immune challenge in young and old mice. Several differences in the anatomy of the spleen with age in both the immune and stromal cells were observed. There is an age‐related increase in the overall size of the white pulp, which occurs primarily within the T‐cell zone and is mirrored by the enlargement of the T‐cell stromal area, concurrent to the distinct boundary between T cells and B cells becoming less defined in older mice. In conjunction, there appears to be a loss of marginal zone macrophages, which is accompanied by an accumulation of fibroblasts in the spleens from older animals. Furthermore, whereas the reorganization of the white pulp is resolved after several days following antigenic challenge in young animals, it remains perturbed in older subjects. All these age‐related changes within the spleen could potentially contribute to the age‐dependent deficiencies in functional immunity

Microtubules control cellular shape and coherence in amoeboid migrating cells

Cells navigating through complex tissues face a fundamental challenge: while multiple protrusions explore different paths, the cell needs to avoid entanglement. How a cell surveys and then corrects its own shape is poorly understood. Here, we demonstrate that spatially distinct microtubule dynamics regulate amoeboid cell migration by locally promoting the retraction of protrusions. In migrating dendritic cells, local microtubule depolymerization within protrusions remote from the microtubule organizing center triggers actomyosin contractility controlled by RhoA and its exchange factor Lfc. Depletion of Lfc leads to aberrant myosin localization, thereby causing two effects that rate-limit locomotion: (1) impaired cell edge coordination during path finding and (2) defective adhesion resolution. Compromised shape control is particularly hindering in geometrically complex microenvironments, where it leads to entanglement and ultimately fragmentation of the cell body. We thus demonstrate that microtubules can act as a proprioceptive device: they sense cell shape and control actomyosin retraction to sustain cellular coherence

Platelet-rich plasma induces post-natal maturation of immature articular cartilage and correlates with LOXL1 activation

Platelet-­rich plasma (PRP) is used to stimulate the repair of acute and chronic cartilage damage even though there is no definitive evidence of how this is achieved. Chondrocytes in injured and diseased situations frequently re­ express phenotypic biomarkers of immature cartilage so tissue maturation is a potential pathway for restoration of normal structure and function. We used an in vitro model of growth factor­induced maturation to perform a comparative study in order to determine whether PRP can also induce this specific form of remodeling that is characterised by increased cellular proliferation and tissue stiffness. Gene expression patterns specific for maturation were mimicked in PRP treated cartilage, with chondromodulin, collagen types II/X downregulated, deiodinase II and netrin­1 upregulated. PRP increased cartilage surface cell density 1.5­fold (P < 0.05), confirmed by bromodeoxyuridine incorporation and proportionate increases in proliferating cell nuclear antigen gene expression. Atomic force microscopy analysis of PRP and growth factor treated cartilage gave a 5­fold increase in stiffness correlating with a 10­fold upregulation of lysyl oxidase like­1 gene expression (P < 0.001). These data show PRP induces key aspects of post­natal maturation in immature cartilage and provides the basis to evaluate a new biological rationale for its activity when used clinically to initiate joint repair

Site-specific analysis of gene expression in early osteoarthritis using the Pond-Nuki model in dogs

BACKGROUND: Osteoarthritis (OA) is a progressive and debilitating disease that often develops from a focal lesion and may take years to clinically manifest to a complete loss of joint structure and function. Currently, there is not a cure for OA, but early diagnosis and initiation of treatment may dramatically improve the prognosis and quality of life for affected individuals. This study was designed to determine the feasibility of analyzing changes in gene expression of articular cartilage using the Pond-Nuki model two weeks after ACL-transection in dogs, and to characterize the changes observed at this time point. METHODS: The ACL of four dogs was completely transected arthroscopically, and the contralateral limb was used as the non-operated control. After two weeks the dogs were euthanatized and tissues harvested from the tibial plateau and femoral condyles of both limbs. Two dogs were used for histologic analysis and Mankin scoring. From the other two dogs the surface of the femoral condyle and tibial plateau were divided into four regions each, and tissues were harvested from each region for biochemical (GAG and HP) and gene expression analysis. Significant changes in gene expression were determined using REST-XL, and Mann-Whitney rank sum test was used to analyze biochemical data. Significance was set at (p < 0.05). RESULTS: Significant differences were not observed between ACL-X and control limbs for Mankin scores or GAG and HP tissue content. Further, damage to the tissue was not observed grossly by India ink staining. However, significant changes in gene expression were observed between ACL-X and control tissues from each region analyzed, and indicate that a unique regional gene expression profile for impending ACL-X induced joint pathology may be identified in future studies. CONCLUSION: The data obtained from this study lend credence to the research approach and model for the characterization of OA, and the identification and validation of future diagnostic modalities. Further, the changes observed in this study may reflect the earliest changes in AC reported during the development of OA, and may signify pathologic changes within a stage of disease that is potentially reversible