Xenotransplantation of pig chondrocytes: therapeutic potential and barriers for cartilage repair

Transplantation may be the best option for the repair of many cartilage lesions including early osteoarthritis. Currently, autologous and allogeneic chondrocytes are grafted into cartilage defects to treat selected patients with moderate clinical success. However, their limited use justifies exploring novel therapies for cartilage repair. Xenotransplantation could become a solution by offering high cell availability, quality and genetic engineering capabilities. The rejection process of xenogeneic cartilage is thus being elucidated in order to develop counteractive strategies. Initial studies determined that pig cartilage xenografts are rejected by a slow process comprising humoral and cellular responses in which the galactose α1,3-galactose antigen participates. Since then, our group has identified key mechanisms of the human response to pig chondrocytes (PCs). In particular, human antibody and complement contribute to PC rejection by inducing a pro-inflammatory milieu. Furthermore, PCs express and up-regulate molecules which are functionally relevant for a variety of cellular immune responses (SLA-I, the potent co-stimulatory molecule CD86, and adhesion molecules VCAM-1 and ICAM-1). These participate by triggering a T cell response, as well as supporting a prominent role of the innate immune responses led by natural killer (NK) cells and monocytes/macrophages. Human NK cells lyse PCs by using selected NK activating receptors, whereas human monocytes are activated by PCs to secrete cytokines and chemokines. All this knowledge sets the bases for the development of genetic engineering approaches designed to avert rejection of xenogeneic chondrocytes and leads the way to developing new clinical applications for cartilage repair.

Septic arthritis caused by Peptostreptococcus asaccharolyticus

Peptostreptococcus spp are commensal organisms, usually involved in periodontal disease. Peptostreptococcus asaccharolyticus is an anaerobic gram-negative cocci, difficult to isolate due to its slow growth. Septic arthritis by this microorganism is a rare entity, but it can occur by hematogenous dissemination from a distant focus. Colonization and growth are more likely to occur in an already damaged articulation. We report the case of a 57 year-old woman with peripheral spondyloarthritis who developed knee septic arthritis by Peptostreptococcus asaccharolyticus.

Psychometric properties of the Revised Fibromyalgia Impact Questionnaire (FIQR) - a contribution to the Portuguese validation of the scale

BACKGROUND

Fibromyalgia (FM) remains a relatively misunderstood and clinically challenging condition that impact significantly in the individual´s life, impairing global functioning and diminishing quality of life. Management is complex and frequently unsatisfactory, requiring personal tailoring and adaptation of interventions according to the fluctuations of the disease manifestations and their response to therapy. The use of comprehensive and quantified assessment tools constitutes, therefore, an essential component of the management of patients with FM. The Revised Fibromyalgia Impact Questionnaire (FIQR) is currently one of the most used and well validated instruments to assess functional (in)capacity and global impact of FM and associated symptoms.

OBJECTIVES

To translate to Portuguese the FIQR and to study its psychometric properties.

MATERIAL AND METHODS

The total sample comprised 103 women with fibromyalgia, defined according to the established criteria for FM. A self-report battery composed by the Revised Fibromyalgia Impact Questionnaire (FIQR), the Portuguese version of Beck Depression Inventory-II (BDI-II) and the Profile of Mood States (PoMS) was administered. The FIQR was re-administered to twenty-four participants, six weeks after the first evaluation. Internal reliability was assessed through Cronbach's alpha, corrected item-total score correlations and alpha if item deleted. Spearman and Pearson correlations along with repeated measures tests were computed to assess the temporal stability of the scale. Convergent and divergent validity were assessed via Spearman and Pearson correlations.

RESULTS

The FIQR demonstrated a good to very good internal consistency (from α = 0.87 to α = 0.94). All items correlated to a good degree (above 0.30) to the total score and contributed significantly to the overall reliability. Moreover, FIQR presented a good temporal stability (from r = .617 to r = .886, p ≤ .001) and favorable convergent and discriminant validity with depressive symptoms (r > .289, p ≤ .01) and positive (r > -.186, p > .05) and negative affect (r > .206, p ≤ .05).

CONCLUSIONS

The Portuguese version of the FIQR demonstrated good psychometric properties, which renders it a proper and valuable tool to be used in different settings.

Exploring the factorial structure of the revised Fibromyalgia Impact Questionnaire (FIQR) in a Portuguese sample of fibromyalgia patients

Introduction

The Revised-Fibromyalgia Impact Questionnaire (FIQR), composed by 21 items, is one of the most used tools to measure the impact of fibromyalgia both in clinical and research settings. Although it has demonstrated good psychometric properties (Bennet et al., 2009; Costa et al., 2015), little is known about its factorial structure.

Objective/Aims

To explore FIQR's factorial structure and examine its association with several psychological constructs.

Methods

Hundred and three women with fibromyalgia (mean age 47.32 ± 10.63) filled in the Portuguese validated versions of the FIQR, Perceived Stress Scale, Perseverative Thinking Questionnaire, Beck Depression Inventory-II and Profile of Mood States. A principal components analysis with varimax rotation was carried out. The number of factors to extract was based on Cattel's scree plot and eigenvalues’ magnitude. The associations between FIQR dimensions and psychological constructs were examined via Pearson correlations and multiple linear regressions.

Results

Three factors were extracted [F1/Function = Items 1–9, α = 0.92; F2/Symptoms = Items 12, 16–21, α = 0.83; F3/Impact = Items 10, 11, 13–15, α = 0.83] explaining 58.57% of the variance. FIQR symptoms were the best and, nearly in all analyses, the only significant predictor.

Conclusions

The factorial structure of the Portuguese version of FIQR partially overlaps with the proposed theoretical domains (Bennet et al., 2009). Similarly to Luciano et al.’s study (2013), factorial analysis also evidenced the multidimensionality of some items. Fibromyalgia symptoms seem to play the most deleterious effect, being associated with poor mental health indicators. Future studies are needed to confirm the factorial structure found, due to sample size, items subjectivity and study's exploratory nature.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

[Dermatomyositis-like syndrome in x-linked agammaglobulinemia]

Primary immunodeficiencies (PIDs) encompass more than 250 different pathological conditions. X-linked agammaglobulinemia (XLA) has been occasionally associated with cutaneous and muscular manifestations resembling dermatomyositis, often termed dermatomyositis-like syndrome (DLS). This syndrome has been associated with cutaneous, muscular and central nervous system manifestations, accompanying a persistent infection by an Echovirus. According to sixteen previously reported cases, this syndrome has a poor prognosis. We report the case of a 27-years old male, with XLA and DLS, successfully treated with 6 cycles of human immunoglobulin and methotrexate. Clinical symptoms improved dramatically with a complete resolution of the musculoskeletal manifestations. Despite this clinical response, prognosis should remain reserved. The evolution of this syndrome remains unpredictable and therapeutic options are limited. To the best of our knowledge, there are only a few reports of similar cases which have survived so many months after the diagnosis.

Genetic engineering strategies to prevent the effects of antibody and complement on xenogeneic chondrocytes

Advances in animal transgenesis may allow using xenogeneic chondrocytes in tissue-engineering applications for clinical cartilage repair. Porcine cartilage is rejected by humoral and cellular mechanisms that could be overcome by identifying key molecules triggering rejection and developing effective genetic-engineering strategies. Accordingly, high expression of α1,2-fucosyltransferase (HT) in xenogeneic cartilage protects from galactose α1,3-galactose (Gal)-mediated antibody responses. Now, we studied whether expression of a complement inhibitor provides further protection. First, porcine articular chondrocytes (PAC) were isolated from non-transgenic, single and double transgenic pigs expressing HT and moderate levels of human CD59 (hCD59) and their response to human serum was assessed. High recombinant expression of human complement regulatory molecules hCD59 and hDAF was also attained by retroviral transduction of PAC for further analyses. Complement activation on PAC after exposure to 20 % human serum for 24 hours mainly triggered the release of pro-inflammatory cytokines IL-6 and IL-8. Transgenic expression of HT and hCD59 did not suffice to fully counteract this effect. Nevertheless, the combination of blocking anti-Gal antibodies (or C5a) and high hCD59 levels conferred very high protection. On the contrary, high hDAF expression attained the most dramatic reduction in IL-6/IL-8 secretion by a single strategy, but the additional inhibition of anti-Gal antibodies or C5a did not provide further improvement. Notably, we demonstrate that both hCD59 and hDAF inhibit anaphylatoxin release in this setting. In conclusion, our study identifies genetic-engineering approaches to prevent humoral rejection of xenogeneic chondrocytes for use in cartilage repair.

Progesterone 5β-reductase genes of the Brassicaceae family as function-associated molecular markers

This study aimed to define progesterone 5β-reductases (P5βR, EC 1.3.99.6, enone 1,4-reductases) as function-associated molecular markers at the plant family level. Therefore cDNAs were isolated from 25 Brassicaceae species, including two species, Erysimum crepidifolium and Draba aizoides, known to produce cardiac glycosides. The sequences were used in a molecular phylogeny study. The cladogram created is congruent to the existing molecular analyses. Recombinant His-tagged forms of the P5βR cDNAs from Aethionema grandiflorum, Draba aizoides, Nasturtium officinale, Raphanus sativus and Sisymbrium officinale were expressed in E. coli. Enone 1,4-reductase activity was demonstrated in vitro using progesterone and 2-cyclohexen-1-one as substrates. Evidence is provided that functional P5βRs are ubiquitous in the Brassicaceae. The recombinant P5βR enzymes showed different substrate preferences towards progesterone and 2-cyclohexen-1-one. Sequence comparison of the catalytic pocket of the P5βR enzymes and homology modelling using Digitalis lanata P5βR (PDB ID: 2V6G) as template highlighted the importance of the hydrophobicity of the binding pocket for substrate discrimination. It is concluded that P5βR genes or P5βR proteins can be used as valuable function-associated molecular markers to infer taxonomic relationship and evolutionary diversification from a metabolic/catalytic perspective.

Expression of semaphorin 3A, semaphorin 7A and their receptors in multiple sclerosis lesions

Background:

Studies in multiple sclerosis (MS) and in experimental models point to a critical role of semaphorin (sema)3A and sema7A in MS pathogenesis.

Objective:

The objective of this paper is to characterise the expression of sema3A, sema7A, and their receptors in MS lesions.

Methods:

We included 44 demyelinating lesions from MS patients, 12 lesions with acute cerebral infarct, 11 lesions with progressive multifocal leucoencephalopathy and 10 non-neurological control patients. MS lesions were classified according to inflammatory activity and all samples were immunostained for sema3A, sema7A, neuropilin 1 (Np-1), α1-integrin, and β1-integrin.

Results:

In MS-damaged white matter sema3A and Np-1 were both detected in microglia/macrophages, whereas reactive astrocytes expressed only sema3A. Otherwise, sema7A, α1-integrin and β1-integrin were observed in reactive astrocytes, and microglia/macrophages only expressed β1-integrin. The expression of sema3A, sema7A and their receptors is more relevant in MS than in other demyelinating diseases. Sema3A and sema7A expression correlated with the inflammatory activity of the MS lesions, suggesting their involvement in the immunological process that takes place in MS.

Conclusions:

The expression pattern of sema3A, sema7A and their receptors in MS lesions suggests that both molecules contribute to create a negative environment for tissue regeneration, influencing the ability to regenerate the damaged tissue.

Influence of input material and operational performance on the physical and chemical properties of MSW compost

Certain controversy exists about the use of compost from MSW (municipal solid waste) and, specifically, from the organic fraction of MSW that has not been separated at the source. In this case, the final composition of MSW compost is related to the performance of the separation process in MBT (Mechanical and Biological Treatment) plants as well as the composition of raw materials and the particular features of composting systems. In an effort to investigate the quality of MSW compost, 30 samples of this product obtained from 10 different MBT plants were studied. The main physical and chemical properties were analyzed and were compared with the requirements of current legislation. The composting systems used to produce these compost samples were studied and the input materials were characterized. The results reveal that the heavy metal content in MSW compost was below the legal restrictions in all samples but one; however, in most of them the percentage of Pb was high. The fertilizing potential of MSW compost has been demonstrated by its high nutrient concentrations, particularly N, K, P, Ca and Mg. Nevertheless, here the percentage of inert impurities with a size larger than 2 mm, such as plastic or glass, was seen to be excessively high exceeding in some cases the legal limit. The source of such pollution lies in the composting inputs, OFMSW (organic fraction of MSW), which showed high percentages of improper materials such as plastic (9%) or glass (11%). Accordingly, the performance of the sorting stage for the collection of the raw material must be improved, as must the refining process, since this does not remove the necessary amounts of these impurities from the final compost.

In Contrast to Anti-C5 Therapy, Cobra Venom Factor Does Not Prevent Rejection of Xenogeneic Cartilage in Mice

BACKGROUND

The use of xenogeneic chondrocytes may benefit the development of clinical tissue-engineering applications for cartilage repair. However, cartilage xenografts are slowly rejected by humoral and cellular mechanisms to which galactose α1,3-galactose (Gal) antigen and complement contribute. Accordingly, transgenic expression of human α1,2-fucosyltransferase (HT) in porcine cartilage helps to protect from the Gal-mediated immune response. Here, we aimed to assess the effect of the broadly used complement inhibitor cobra venom factor (CVF) in comparison with anti-C5 therapy in α1,3-galactosyltransferase knockout (Gal KO) mice transplanted with porcine cartilage.

METHODS

Gal KO mice grafted with control or HT-transgenic cartilage were left untreated or treated systemically with either anti-C5 antibody or CVF for 5 weeks. The degree of rejection was evaluated by use of histopathological analysis, and serum anti-Gal antibodies were measured in all cohorts.

RESULTS

The rejection process of control cartilage was well advanced by 5 weeks after transplantation in untreated Gal KO mice, whereas enhanced graft survival characterized by reduced cellular immune infiltrate was found in mice grafted with HT cartilage and/or treated with anti-C5. In contrast, CVF administration led to inconsistent results, with some grafts showing no improvement or even increased amounts of granulocytes. Regarding antibody titers, the anti-Gal immunoglobulin (Ig)M increased in the control transplant cohort and remained unchanged in the HT-graft recipients at 5 weeks after transplantation. Notably, a strong anti-Gal IgM response was readily detected in CVF-treated mice of both transplanted cohorts.

CONCLUSIONS

CVF does not present advantages over anti-C5 therapy for preventing rejection of xenogeneic porcine cartilage.