The cartilage-specific lectin C-type lectin domain family 3 member A (CLEC3A) enhances tissue plasminogen activator-mediated plasminogen activation.

C-type lectin domain family 3 member A (CLEC3A) is a poorly characterized protein belonging to the superfamily of C-type lectins. Its closest homologue tetranectin binds to the kringle 4 domain of plasminogen and enhances its association with tissue plasminogen activator (tPA) thereby enhancing plasmin production, but whether CLEC3A contributes to plasminogen activation is unknown. Here, we recombinantly expressed murine and human full-length CLEC3As as well as truncated forms of CLEC3A in HEK-293 Epstein-Barr nuclear antigen (EBNA) cells. We analyzed the structure of recombinant CLEC3A by SDS-PAGE and immunoblot, glycan analysis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, size-exclusion chromatography, circular dichroism spectroscopy, and electron microscopy; compared the properties of the recombinant protein with those of CLEC3A extracted from cartilage; and investigated its tissue distribution and extracellular assembly by immunohistochemistry and immunofluorescence microscopy. We found that CLEC3A mainly occurs as a monomer, but also forms dimers and trimers, potentially via a coiled-coil α-helix. We also noted that CLEC3A can be modified with chondroitin/dermatan sulfate side chains and tends to oligomerize to form higher aggregates. We show that CLEC3A is present in resting, proliferating, and hypertrophic growth-plate cartilage and assembles into an extended extracellular network in cultures of rat chondrosarcoma cells. Further, we found that CLEC3A specifically binds to plasminogen and enhances tPA-mediated plasminogen activation. In summary, we have determined the structure, tissue distribution, and molecular function of the cartilage-specific lectin CLEC3A and show that CLEC3A binds to plasminogen and participates in tPA-mediated plasminogen activation.

Identification of antibodies against extracellular matrix proteins in human osteoarthritis.

We investigated the presence of autoantibodies against the extracellular matrix proteins thrombospondin-4 (TSP-4), cartilage oligomeric matrix protein (COMP), C-type lectin domain family 3 member A (CLEC3A), collagen II, collagen VI, matrilin-3, and fibrillin-2 in the serum of osteoarthritis (OA) patients. We compared those results with the presence of such antibodies in rheumatoid arthritis (RA) patients and in healthy donors (HD). Our study examines whether antibodies against extracellular proteins can be used as potential biomarkers to support the clinical diagnosis of OA. 10 OA, 10 RA patients and 10 HD were enrolled in this explorative cross-sectional study. SDS-PAGE and immunoblot were used to investigate the presence of antibodies against extracellular matrix proteins. The serum of 5/10 OA patients but 0/10 HD exhibited TSP-4 IgG isotype antibodies (P = 0.033). The serum of 8/10 OA patients but only 1/10 HD exhibited IgG isotype antibodies against TSP-4 or COMP (P = 0.005). The serum of 9/10 OA patients but only 1/10 HD exhibited IgG isotype antibodies against TSP-4, COMP or CLEC3A (P = 0.005). We found strong evidence for the presence of IgG isotype autoantibodies against the cartilage extracellular matrix proteins TSP-4, COMP and CLEC3A in OA. The detection of IgG isotype autoantibodies against TSP-4, COMP and CLEC3A may support the clinical diagnosis of OA. OA with autoantibodies against cartilage extracellular matrix proteins defines a new OA subgroup suggesting that patients with high concentrations of autoantibodies may benefit from an immune suppressive therapy.

Modified CLEC3A-Derived Antimicrobial Peptides Lead to Enhanced Antimicrobial Activity against Drug-Resistant Bacteria.

Antimicrobial peptides (AMPs) represent a promising alternative to conventional antibiotics. Sequence changes can significantly improve the therapeutic properties of antimicrobial peptides. In our study, we apply different sequence modifications to enhance the performance of the CLEC3A-derived AMPs HT-16 and HT-47. We truncated their sequences, inserting a triple-glycine linker, adding an N-terminal tryptophan residue, and generating a D-amino acid variant, resulting in the generation of seven new peptides. We investigated their antimicrobial activity against gram-positive and gram-negative bacteria, their cytotoxicity to murine cells, and the biostability of the modified peptides in serum. We identified a novel antimicrobial peptide, WRK-30, with enhanced antimicrobial potency against S. aureus and MRSA. Additionally, WRK-30 was less cytotoxic to eukaryotic cells, allowing its application in higher concentrations in an in vivo setting. In conclusion, we identified a novel CLEC3A-derived antimicrobial peptide WRK-30 with significantly improved therapeutic properties and the potential to widen the repertoire of conventional antibiotics.

The ratio of serum LL-37 levels to blood leucocyte count correlates with COVID-19 severity.

Beneficial effects of vitamin D on COVID-19 progression have been discussed in several studies. Vitamin D stimulates the expression of the antimicrobial peptide LL-37, and evidence shows that LL-37 can antagonize SARS-CoV-2. Therefore, we investigated the association between LL-37 and vitamin D serum levels and the severity of COVID-19. To this end, 78 COVID-19 patients were divided into 5 groups according to disease severity. We determined serum levels of LL-37, vitamin D, and routine laboratory parameters. We demonstrated a correlation of CRP, IL-6, PCT, leukocyte count, and LDH with the severity of COVID-19. Our study did not demonstrate a direct relationship between serum levels of LL-37 and vitamin D and the severity of COVID-19. LL-37 is produced by granulocytes and released at the site of inflammation. Therefore, the analysis of LL-37 in broncho-alvelolar lavage rather than in patient serum seems critical. However, since LL-37 is produced by granulocytes, we determined serum LL-37 levels as a function of leukocyte count. The LL-37/leukocyte count ratio correlates highly significantly inversely proportional with COVID-19 severity. Our results indicate that the LL-37/leukocyte count ratio could be used to assess the risk of COVID-19 progression as early as hospital admission.

Analysis of IgM, IgA, and IgG isotype antibodies Directed against SARS-CoV-2 spike glycoprotein and ORF8 in the course of COVID-19.

Immunoassays are a standard diagnostic tool that assesses immunity in severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection. However, immunoassays do not provide information about contaminating antigens or cross-reactions and might exhibit inaccurately high sensitivity and low specificity. We aimed to gain insight into the serological immune response of SARS-CoV-2 patients by immunoblot analysis. We analyzed serum immunoglobulins IgM, -A, and -G directed against SARS-CoV-2 proteins by immunoblot analysis from 12 infected patients. We determined IgG isotype antibodies by commercially available ELISA and assessed the clinical parameters of inflammation status and kidney and liver injury. Unexpectedly, we found no correlation between the presence of antibodies and the future course of the disease. However, attention should be paid to the parameters CRP, IL-6, and LDH. We found evidence of antibody cross-reactivity, which questions the reliability of results for serum samples that tested negative for anti-SARS-CoV-2 antibodies when assessed by immunoassays. Nevertheless, for the detection of IgG anti-SARS-CoV-2 antibodies, our data suggest that the use of the spike glycoprotein in immunoassays should be sufficient to identify positive patients. Using a combination of the spike glycoprotein and the open reading frame 8 protein could prove to be the best way of detecting anti-SARS-CoV-2 IgM antibodies.

Adesão ao tratamento farmacológico em idosos: uma revisão integrativa da literatura / Adherencia al tratamiento farmacológico en el anciano: revisión integradora de la literatura / Adherence to pharmacological treatment in the aged: an integrative literature review

Objetivo: Identificaros fatores relacionados à adesão ao tratamento farmacológico em idosos. Método: trata-se de estudo bibliográfico, tipo revisão integrativa, realizado nas bases de dados LILACS, PubMed, Scopus, Web Of Science e na Biblioteca Virtual SciELO. Consideraram-se os estudos originais, disponíveis na íntegra e publicados no período de 2013 a 2018. Resultado: Localizou-se 1789 publicações, sendo que 352 eram duplicadas, permanecendo 1437. Após leitura dos títulos e resumos encontrou-se 20 artigos para leitura na íntegra e que representou a amostra final. Conclusão: A adesão ao tratamento por idosos sofre a influência de múltiplos fatores, entre eles socioeconômicos e demográficos, relacionados à condição de saúde, sistema e profissionais, relacionados ao tratamento farmacológico e de estilo de vida e comportamento. O suporte de familiares, amigos e grupos sociais de apoio mostrou-se associada à adesão, assim como percepção positiva da visão e audição, ausência de fragilidade e de declínio cognitivo.

Objetivo: Identificar factores relacionados con la adherencia al tratamiento farmacológico en ancianos. Método: se trata de un estudio bibliográfico, tipo de revisión integradora, realizado en las bases de datos LILACS, PubMed, Scopus, Web Of Science y en la Biblioteca Virtual SciELO. Se consideraron los estudios originales, disponibles íntegramente y publicados en el período de 2013 a 2018. Resultado: se encontraron 1789 publicaciones, de las cuales 352 fueron duplicadas, restando 1437. Luego de la lectura de títulos y resúmenes, se encontraron 20 artículos para lectura en el que representó la muestra final. Conclusión: La adherencia al tratamiento por parte de los ancianos está influenciada por múltiples factores, incluidos los socioeconómicos y demográficos, relacionados con la condición, sistema y profesionales de salud, relacionados con el tratamiento farmacológico y el estilo de vida y la conducta. Se demostró que el apoyo de familiares, amigos y grupos de apoyo social está asociado con la adherencia, así como con la percepción positiva de la visión y la audición, la ausencia de fragilidad y el deterioro cognitivo.

Objective: To identify factors related to adherence to pharmacological treatment in the aged. Method: this is a bibliographic study, type of integrative review, carried out in the databases LILACS, PubMed, Scopus, Web Of Science and in the Virtual Library SciELO. The original studies were considered, available in full and published in the period from 2013 to 2018. Result: 1789 publications were found, of which 352 were duplicated, remaining 1437. After reading the titles and abstracts, 20 articles were found for reading in the that represented the final sample. Conclusion: Adherence to treatment by the aged is influenced by multiple factors, including socioeconomic and demographic factors, related to the health condition, system and professionals, related to pharmacological treatment and lifestyle and behavior. The support of family, friends and social support groups was shown to be associated with adherence, as well as positive perception of vision and hearing, absence of fragility and cognitive decline.

Análise demográfica e socioeconômica do uso de medicamentos por idosos residentes em zona rural / Demographic and socioeconomic analysis of medication use by elderly people living in rural areas

O objetivo deste estudo é analisar a associação de características demográficas e socioeconômicas relacionadas ao uso de medicamentos. Avaliou-se uma amostra de 822 idosos com 60 anos ou mais. A coleta de dados ocorreu no período de julho a outubro de 2014. Obteve-se evidências de associação entre sexo e uso de medicamentos e faixa etária e uso de medicamentos. A prevalência quanto ao uso de pelo menos um medicamento foi de 83%. Os medicamentos para o sistema cardiovascular foram os mais prevalentes, seguidos do trato alimentar e metabolismo e sistema nervoso. Destaca-se a grande quantidade de medicamentos utilizados para Doenças Crônicas Não Transmissíveis, deste modo, ressalta-se a importância da atenção integral a saúde do idoso.

The objective of this study is to analyze the association of demographic and socioeconomic characteristics related to medication use. A sample of 822 elderly people aged 60 years or older was evaluated. Data collection took place from July to October 2014. Evidence of associations between sex and medication use and age group and medication use was obtained. The prevalence regarding the use of at least one medication was 83%. Medications for the cardiovascular system were the most prevalent, followed by the dietary tract, and metabolism and nervous system. The large amount of drugs used for Chronic Non-Communicable Diseases stands out, thus, the importance of comprehensive health care for the elderly is highlighted.

Conhecimentos, atitudes e práticas em saúde do idoso da zona rural / Knowledge, attitudes and practices in health of the rural area elderly

Objetivo: identificar os conhecimentos, atitudes e práticas em saúde de idosos residentes em zona rural. Método: trata-se de estudo bibliográfico, tipo revisão integrativa, realizado nas bases de dados MEDLINE, LILACS, Web of Science, Scopus e na biblioteca virtual SciELO. Consideraram-se os estudos originais qualitativos, disponíveis na íntegra e publicados no período de 2013 a 2017. Analisaram-se os dados referentes à local e ano de publicação, objetivos, métodos e resultados. Apresentaram-se os resultados em forma de figuras. Resultados: analisaram-se oito estudos publicados em periódicos internacionais resultando em categorias. Conclusão: constata-se que os conhecimentos em saúde dos idosos residentes em zona rural são frágeis, principalmente, no que se refere a identificação de fatores de risco e sinais e sintomas de doenças e agravos. As atitudes e práticas em saúde revelam a dificuldade de adesão/compreensão de ações de promoção da saúde e prevenção de doenças e agravos, possivelmente devido a falta de um cuidado culturalmente congruente.(AU)

Objective: to identify the knowledge, attitudes and practices in health of elderly people living in rural areas. Method: this is a bibliographical study, type integrative, carried out in the MEDLINE, LILACS, Web of Science, Scopus and SciELO virtual libraries. The original qualitative studies, available in full and published between 2013 and 2017, were considered. Data on location and year of publication, objectives, methods and results were analyzed. The results were presented in the form of figures. Results: eight studies published in international journals were analyzed, resulting in the categories. Conclusion: it is verified that the health knowledge of the elderly living in rural areas is fragile, mainly, in the identification of risk factors and signs and symptoms of diseases and injuries. Health attitudes and practices reveal the difficulty of adherence / understanding of health promotion actions and prevention of diseases and injuries, possibly due to a lack of culturally congruent care.(AU)

Objetivo: identificar los conocimientos, actitudes y prácticas en salud de ancianos residentes en zona rural. Método: se trata de estudio bibliográfico, tipo revisión integrativa, realizado en las bases de datos MEDLINE, LILACS, Web of Science, Scopus y en la biblioteca virtual SciELO. Se consideraron los estudios originales cualitativos, disponibles en su totalidad y publicados en el período de 2013 a 2017. Se analizaron los datos referentes a la ubicación y año de publicación, objetivos, métodos y resultados. Se presentaron los resultados en forma de figuras. Resultados: se analizaron ocho estudios publicados en periódicos internacionales resultando en las categorías. Conclusión: se constata que los conocimientos en salud de los ancianos residentes en zonas rurales son frágiles, principalmente, en lo que se refiere a la identificación de factores de riesgo y signos y síntomas de enfermedades y agravios. Las actitudes y prácticas en salud revelan la dificultad de adhesión / comprensión de acciones de promoción de la salud y prevención de enfermedades y agravios, posiblemente debido a la falta de un cuidado culturalmente congruente.(AU)