The Collagen Binding Domain of Gelatinase A Modulates Degradation of Collagen IV by Gelatinase B

Type IV collagen remodeling plays a critical role in inflammatory responses, angiogenesis and metastasis. Its remodeling is executed by a family of matrix metalloproteinases (MMPs), of which the constitutive gelatinase A (MMP2) and the inducible gelatinase B (MMP9) are key examples. Thus, in many pathological conditions, both gelatinases act together. Kinetic data are reported for the enzymatic processing at 37 degrees C of type IV collagen from human placenta by MMP9 and its modulation by the fibronectin-like collagen binding domain (CBD) of MMP2. The alpha l and alpha 2 chain components of type IV collagen were cleaved by gelatinases and identified by mass spectrometry as well as Edman sequencing. Surface plasmon resonance interaction assays showed that CBD bound type IV collagen at two topologically distinct sites. On the basis of linked-function analysis, we demonstrated that CBD of MMP2 tuned the cleavage of collagen IV by MMP9, presumably by inducing a ligand-linked structural change on the type IV collagen. At low, concentrations, the CBD bound the first site and thereby allosterically modulated the binding of MMP9 to collagen IV, thus enhancing the collagenolytic activity of MMP9. At high concentrations, CBD binding to the second site interfered with MMP9 binding to collagen IV, acting as a competitive inhibitor. Interestingly, modulation of collagen IV degradation by inactive forms of MMP2 also occurred in a cell-based system, revealing that this interrelationship affected neutrophil migration across a collagen IV membrane. The regulation of the proteolytic processing by a catalytically inactive domain (i.e., CBD) suggests that the two gelatinases might cooperate in degrading substrates even when either one is inactive. This observation reinforces the idea of exosite targets for MMP inhibitors, which should include all macromolecular substrate recognition site

Canine sterile steroid-responsive lymphadenitis in 49 dogs

OBJECTIVES:To report clinical and laboratory features, treatment responses and outcome in dogs diagnosed with sterile steroid-responsive lymphadenitis in the United Kingdom. MATERIALS AND METHODS:Medical records of dogs diagnosed with sterile steroid-responsive lymphadenitis from 2009 to 2016 at six specialist referral centres were evaluated retrospectively. RESULTS:The study included 49 dogs. Springer spaniels appeared to be over-represented (16 of 49 dogs). Young dogs (median age: 3 years and 9 months) and females (31 of 49) were frequently affected. Clinical presentation was variable, with pyrexia (39 of 49), lethargy (35 of 49) and anorexia (21 of 49) the most commonly reported clinical signs. Lymph node cytology or histopathology demonstrated neutrophilic, pyogranulomatous, granulomatous or necrotising lymphadenitis without a detectable underlying cause in all cases. Because a sterile immune-mediated aetiology was suspected, all dogs received prednisolone, which was followed by rapid resolution of clinical signs and lymphadenopathy in most cases. CLINICAL SIGNIFICANCE:Sterile steroid-responsive lymphadenitis should be considered in dogs with pyrexia of unknown origin with inflammatory lymphadenopathy if no underlying cause can be found and often responds well to immunosuppressive corticosteroid therapy

Consensus on treatment for residents in long-term care facilities : perspectives from relatives and care staff in the PACE cross-sectional study in 6 European countries

Background: In long-term care facilities often many care providers are involved, which could make it difficult to reach consensus in care. This may harm the relation between care providers and can complicate care. This study aimed to describe and compare in six European countries the degree of consensus among everyone involved in care decisions, from the perspective of relatives and care staff. Another aim was to assess which factors are associated with reporting that full consensus was reached, from the perspective of care staff and relatives.Methods: In Belgium, England, Finland, Italy, the Netherlands and Poland a random sample of representative long-term care facilities reported all deaths of residents in the previous three months (n = 1707). This study included residents about whom care staff (n = 1284) and relatives (n = 790) indicated in questionnaires the degree of consensus among all involved in the decision or care process. To account for clustering on facility level, Generalized Estimating Equations were conducted to analyse the degree of consensus across countries and factors associated with full consensus.Results: Relatives indicated full consensus in more than half of the residents in all countries (NL 57.9% - EN 68%), except in Finland (40.7%). Care staff reported full consensus in 59.5% of residents in Finland to 86.1% of residents in England. Relatives more likely reported full consensus when: the resident was more comfortable or talked about treatment preferences, a care provider explained what palliative care is, family-physician communication was well perceived, their relation to the resident was other than child (compared to spouse/partner) or if they lived in Poland or Belgium (compared to Finland). Care staff more often indicated full consensus when they rated a higher comfort level of the resident, or if they lived in Italy, the Netherland, Poland or England (compared to Finland).Conclusions: In most countries the frequency of full consensus among all involved in care decisions was relatively high. Across countries care staff indicated full consensus more often and no consensus less often than relatives. Advance care planning, comfort and good communication between relatives and care professionals could play a role in achieving full consensus

Consensus definition of advance care planning in dementia: A 33-country Delphi study.

Existing advance care planning (ACP) definitional frameworks apply to individuals with decision-making capacity. We aimed to conceptualize ACP for dementia in terms of its definition and issues that deserve particular attention. Delphi study with phases: (A) adaptation of a generic ACP framework by a task force of the European Association for Palliative Care (EAPC); (B) four online surveys by 107 experts from 33 countries, September 2021 to June 2022; (C) approval by the EAPC board. ACP in dementia was defined as a communication process adapted to the person's capacity, which includes, and is continued with, family if available. We identified pragmatic boundaries regarding participation and time (i.e., current or end-of-life care). Three interrelated issues that deserve particular attention were capacity, family, and engagement and communication. A communication and relationship-centered definitional framework of ACP in dementia evolved through international consensus supporting inclusiveness of persons with dementia and their family. This article offers a consensus definitional framework of advance care planning in dementia. The definition covers all stages of capacity and includes family caregivers. Particularly important are (1) capacity, (2) family, (3) engagement, and communication. Fluctuating capacity was visualized in relation to roles and engaging stakeholders

Direct Visualization of Protease Action on Collagen Triple Helical Structure

Enzymatic processing of extracellular matrix (ECM) macromolecules by matrix metalloproteases (MMPs) is crucial in mediating physiological and pathological cell processes. However, the molecular mechanisms leading to effective physiological enzyme-ECM interactions remain elusive. Only scant information is available on the mode by which matrix proteases degrade ECM substrates. An example is the enzymatic degradation of triple helical collagen II fragments, generated by the collagenase MMP-8 cleavage, during the course of acute inflammatory conditions by gelatinase B/MMP-9. As is the case for many other matrix proteases, it is not clear how MMP-9 recognizes, binds and digests collagen in this important physiological process. We used single molecule imaging to directly visualize this protease during its interaction with collagen fragments. We show that the initial binding is mediated by the diffusion of the protease along the ordered helix on the collagen ¾ fragment, with preferential binding of the collagen tail. As the reaction progressed and prior to collagen degradation, gelatin-like morphologies resulting from the denaturation of the triple helical collagen were observed. Remarkably, this activity was independent of enzyme proteolysis and was accompanied by significant conformational changes of the working protease. Here we provide the first direct visualization of highly complex mechanisms of macromolecular interactions governing the enzymatic processing of ECM substrates by physiological protease

Care staff's self-efficacy regarding end-of-life communication in the long-term care setting:Results of the PACE cross-sectional study in six European countries

Background: An important part of palliative care is discussing preferences at end of life, however such conversations may not often occur. Care staff with greater self-efficacy towards end-of-life communication are probably more likely to have such discussions, however, there is a lack of research on self-efficacy towards end-of-life discussions among long-term care staff in Europe and related factors. Objectives: Firstly, to describe and compare the self-efficacy level of long-term care staff regarding end-of-life communication across six countries; secondly, to analyse characteristics of staff and facilities which are associated to self-efficacy towards end-of-life communication. Design: Cross-sectional survey. Settings: Long-term care facilities in Belgium, England, Finland, Italy, the Netherlands and Poland (n = 290). Participants: Nurses and care assistants (n = 1680) completed a self-efficacy scale and were included in the analyses. Methods: Care staff rated their self-efficacy (confidence in their own ability) on a scale of 0 (cannot do at all) to 7 -(certain can do) of the 8-item communication subscale of the Self-efficacy in End-of-Life Care survey. Staff characteristics included age, gender, professional role, education level, training in palliative care and years working in direct care. Facility characteristics included facility type and availability of palliative care guidelines, palliative care team and palliative care advice. Analyses were conducted using Generalized Estimating Equations, to account for clustering of data at facility level. Results: Thde proportion of staff with a mean self-efficacy score >5 was highest in the Netherlands (76.4%), ranged between 55.9% and 60.0% in Belgium, Poland, England and Finland and was lowest in Italy (29.6%). Higher levels of self-efficacy (>5) were associated with: staff over 50 years of age (OR 1.86 95% CI[1.30–2.65]); nurses (compared to care assistants) (1.75 [1.20–2.54]); completion of higher secondary or tertiary education (respectively 2.22 [1.53–3.21] and 3.11 [2.05–4.71]; formal palliative care training (1.71 [1.32–2.21]); working in direct care for over 10 years (1.53 [1.14–2.05]); working in a facility with care provided by onsite nurses and care assistants and offsite physicians (1.86 [1.30–2.65]); and working in a facility where guidelines for palliative care were available (1.39 [1.03–1.88]). Conclusion: Self-efficacy towards end-of-life communication was most often low in Italy and most often high in the Netherlands. In all countries, low self-efficacy was found relatively often for discussion of prognosis. Palliative care education and guidelines for palliative care could improve the self-efficacy of care staff

Influence of wiring cost on the large-scale architecture of human cortical connectivity

In the past two decades some fundamental properties of cortical connectivity have been discovered: small-world structure, pronounced hierarchical and modular organisation, and strong core and rich-club structures. A common assumption when interpreting results of this kind is that the observed structural properties are present to enable the brain's function. However, the brain is also embedded into the limited space of the skull and its wiring has associated developmental and metabolic costs. These basic physical and economic aspects place separate, often conflicting, constraints on the brain's connectivity, which must be characterized in order to understand the true relationship between brain structure and function. To address this challenge, here we ask which, and to what extent, aspects of the structural organisation of the brain are conserved if we preserve specific spatial and topological properties of the brain but otherwise randomise its connectivity. We perform a comparative analysis of a connectivity map of the cortical connectome both on high- and low-resolutions utilising three different types of surrogate networks: spatially unconstrained (‘random’), connection length preserving (‘spatial’), and connection length optimised (‘reduced’) surrogates. We find that unconstrained randomisation markedly diminishes all investigated architectural properties of cortical connectivity. By contrast, spatial and reduced surrogates largely preserve most properties and, interestingly, often more so in the reduced surrogates. Specifically, our results suggest that the cortical network is less tightly integrated than its spatial constraints would allow, but more strongly segregated than its spatial constraints would necessitate. We additionally find that hierarchical organisation and rich-club structure of the cortical connectivity are largely preserved in spatial and reduced surrogates and hence may be partially attributable to cortical wiring constraints. In contrast, the high modularity and strong s-core of the high-resolution cortical network are significantly stronger than in the surrogates, underlining their potential functional relevance in the brain