Inmunopatología de la brucelosis osteoarticular / Immunopathology of osteoarticular brucelosis

La brucelosis es una de las enfermedades zoonóticas más importantes a nivel mundial capaz de producir enfermedad crónica en los seres humanos. La localización osteoarticular es la presentación más común de la enfermedad activa en el hombre. Sin embargo, algunos de los mecanismos moleculares implicados en la enfermedad osteoarticular han comenzado a dilucidarse recientemente. Brucella abortus induce daño óseo a través de diversos mecanismos en los cuales están implicados TNF-α y RANKL. En estos procesos participan células inflamatorias que incluyen monocitos/macrófagos, neutrófilos, linfocitos T del tipo Th17 y linfocitos B. Además, B. abortus puede afectar directamente las células osteoarticulares. La bacteria inhibe la deposición de la matriz ósea por los osteoblastos y modifica el fenotipo de estas células para producir metaloproteinasas de matriz (MMPs) y la secreción de citoquinas que contribuyen a la degradación del hueso. Por otro lado, la infección por B. abortus induce un aumento en la osteoclastogénesis, lo que aumenta la resorción de la matriz ósea orgánica y mineral y contribuye al daño óseo. Dado que la patología inducida por Brucella afecta el tejido articular, se estudió el efecto de la infección sobre los sinoviocitos. Estos estudios revelaron que, además de inducir la activación de estas células para secretar quemoquinas, citoquinas proinflamatorias y MMPs, la infección inhibe la muerte por apoptosis de los sinoviocitos. Brucella es una bacteria intracelular que se replica en el retículo endoplásmico de los macrófagos. El análisis de los sinoviocitos infectados con B. abortus indicó que las bacterias también se multiplican en el retículo endoplasmático, lo que sugiere que la bacteria podría usar este tipo celular para la multiplicación intracelular durante la localización osteoarticular de la enfermedad. Los hallazgos presentados en esta revisión intentan responder a preguntas sobre los mediadores inflamatorios implicados en el daño osteoarticular causado por Brucella. (AU)

Brucellosis is one of the most important zoonotic diseases that can produce chronic disease in humans worldwide. Osteoarticular involvement is the most common presentation of human active disease. The molecular mechanisms implicated in bone damage have started to be elucidated. B. abortus induces bone damage through diverse mechanisms in which TNF-α and RANKL are implicated. These processes are driven by inflammatory cells, including monocytes/macrophages, neutrophils, Th17 lymphocytes and B cells. Also, Brucella abortus (B. abortus) can directly affect osteoarticular cells. The bacterium inhibits bone matrix deposition by osteoblast and modifies the phenotype of these cells to produce matrix methalloproteinases (MMPs) and cytokine secretion that contribute to bone matrix degradation. B. abortus also affects osteoclast increasing mineral and organic bone matrix resorption and contributing to bone damage. Since the pathology induced by Brucella species involves joint tissue, experiments conducted in sinoviocytes revealed that besides inducing the activation of these cells to secrete chemokines, proinflammatory cytokines and MMPS, the infection also inhibits sinoviocyte apoptosis. Brucella is an intracellular bacterium that replicate in the endoplasmic reticulum of macrophages. The analysis of B. abortus infected sinoviocytes indicated that bacteria also replicate in their reticulum suggesting that the bacterium could use this cell type for intracellular replication during the osteoarticular localization of the disease. The findings presented in this review try to answer key questions about the inflammatory mediators involved in osteoarticular damage caused by Brucella. (AU)

Remodelamento da matriz extracelular da medula óssea em desnutrição protéica: possível relação da via de AKT com a expressão de fibronectina e metaloproteinases de matriz / Extracellular matriz remodeling of the bone marrow in protein malnutrition: possible relationship of AKT pathway with expression of fibronectin and matriz metalloproteínases

A desnutrição proteica (DP) pode ocasionar alterações na matriz extracelular (MEC) de diferentes órgãos e tecidos, inclusive o hematopoético, com comprometimento funcional. Estudos do nosso laboratório demonstraram, em modelo murino de DP, aumento da expressão proteica de fibronectina (FN) no estroma medular ósseo in vivo, principalmente na região subendosteal (local de fixação da célula tronco progenitora hemopoética). Já in vitro, no estroma medular ósseo, observou-se tanto o aumento quanto a diminuição de FN e a presença de suas isoformas. Essas alterações de FN parecem estar envolvidas com a hipoplasia da medula óssea (MO) em camundongos desnutridos. As modificações quantitativas de FN podem ser devidas: (i) à ação das metaloproteinases de matriz (MMP) responsáveis pela degradação das proteínas da MEC; (ii) aos inibidores de metaloproteinases (TIMP) que regulam a degradação da MEC; (iii) às alterações transcricionais, reguladas pela via de AKT/mTOR, que controla os splicing alternativos na FN, resultando em isoformas dessa proteína; (iv) a processos pós-transcricionais modulados por LC3, que aumenta a tradução do RNAm de FN. Assim, o objetivo deste estudo foi elucidar os mecanismos que alteram o turnover de FN no estroma medular ósseo em modelo murino de DP. Utilizamos camundongos, C57BL/6J machos, adultos, separados em dois grupos: controle e desnutrido, alimentados, ad libitum, com ração contendo 12% e 2% de proteína, respectivamente. Após cinco semanas de indução à desnutrição os camundongos foram eutanasiados, e coletado o material biológico. Avaliamos: o estado nutricional, o hematológico, a histologia da MO femoral bem como a determinação imunohistoquímica da FN, MMP-2 e MMP-9, determinação da expressão de FN e suas isoformas em células totais da MO, o estabelecimento do estroma medular ósseo in vitro, por 28 e 35 dias de cultivo. A partir das culturas foram avaliadas a expressão de RNAm de FN e suas isoformas, MMP-2, MMP-9, TIMP-1, TIMP-2, AKT, mTOR e LC3α e ß, quantificação de MMP-2, MMP-9, TIMP-1, TIMP-2,TNFα, TGFß e IL-1ß e determinação de LC3ß e proteínas da via de AKT/mTOR. Não observamos alterações na expressão do RNAm de FN e suas isoformas ex vivo e in vitro, mas um aumento da deposição de FN na MO.Também não observamos modificações na imunolocalização de MMP-2 e MMP-9 na MO e na atividade dessas proteínas no sobrenadante de culturas de células estromais in vitro, mas houve aumento da expressão do RNAm de MMP-9 em 28 dias de cultivo. Não detectamos alterações na expressão de RNAm e na concentração de TIMP-1 e TIMP-2 no sobrenadante das culturas. Houve redução significativa de TNFα e TGFß no sobrenadante das culturas de 28 dias. Observamos aumento da expressão do RNAm de mTOR em culturas de 28 dias e LC3α e LC3ß em 35 dias de células estromais. Encontramos menor fosforilação de PI3K, AKT, PTEN, mTOR e mTOR total e aumento de LC3ß em culturas de 28 dias, mas redução de LC3ß em 35 dias. Em função dos dados inferimos que a DP conduz a alterações da FN que não estão relacionadas à ação de MMPs e TIMPs e sim a modificações de LC3ß e da via de AKT/mTOR

Protein malnutrition (PM) can lead changes in extracellular matrix (ECM) from several organs and tissues, including hematopoietic, with functional impairments. Research from our laboratory demonstrated, in a murine model of protein malnutrition, increase in proteic expression of fibronectin (FN) in vivo bone marrow stroma, principally in subendosteal region (attachment site of hematopoietic stem/progenitor cell - HSPC). It was observed as both an increase and a decrease in the presence of FN and its isoforms in vitro bone marrow stroma. These FN changes seem to be related to bone marrow (BM) hypoplasia in malnourished mice. Quantitative FN changes may be due to: (i) action of matrix metalloproteinases (MMP) responsible for ECM proteins degradation; (ii) tissue inhibitors of metalloproteinases (TIMP) that regulate ECM degradation; (iii) transicional changes regulated by AKT/mTOR pathway, which controls alternative splicing in FN, resulting in isoforms from this protein; (iv) post-transcriptional processes modulated by LC3 that increases FN mRNA translation. Therefore, the aim of this study was to elucidade the mechanisms that changes the FN turnover in bone marrow stroma in a murine model of PM. C57BL/6J, adult and male mice were used and divided into two groups: control and malnourished, fed ad libitum with ration containing 12% and 2% of protein, respectively. After five weeks of induction malnutrition, mice were euthanized and the biological material was collected. We evaluated: nutritional and hematologic status, the femoral BM histology, immunohistochemistry determination of FN, MMP-2 and MMP-9, the FN and its isoforms expression determination in total BM cells, establishment of in vitro bone marrow stroma for 28 and 35 days of culture. From the cultures were evaluated FN mRNA expressions and its isoforms, MMP-2, MMP-9, TIMP-1, TIMP-2, AKT, mTOR, LC3α and ß, quantification of MMP-2, MMP-9, TIMP-1, TIMP-2,TNFα, TGFß and IL-1ß and determination of LC3ß and AKT/mTOR proteins. No changes were observed, ex vivo and in vitro, in the expression of FN mRNA and its isoforms, but there was a FN deposition increase in BM. We did not observe modifications in MMP-2 e MMP-9 immunolocalization in BM and in these proteins activity in the supernatant of in vitro stromal cell culture, but there was an increase in MMP-9 mRNA expression after 28 days of culture. We did not detect changes in mRNA and in TIMP-1 and TIMP-2 expressions in the supernatant of cultures. There was significant reduction of TNFα and TGFß in the cultures supernatant of 28 days. We observed an increase of mTOR RNAm in 28 days cultures and also LC3α and LC3ß in stromal cells with 35 days. We found lower phosphorylation of PI3K, AKT, PTEN, mTOR e total mTOR and an LC3ß increase in 28 days cultures, yet an LC3ß reduction in 35 days. According to the data we conclude that PM leads to FN changes that are not related to MMPs and TIMPs actions, but the LC3ß and AKT/mTOR pathway modifications

Methods of using click chemistry in the discovery of enzyme inhibitors.

This protocol describes the step-by-step procedures for the efficient assembly of bidentate inhibitor libraries of a target enzyme, using the so-called 'click chemistry' between an alkyne-bearing core group and an azide-modified peripheral group, followed by direct biological screening for the identification of potential 'hits'. The reaction is highlighted by its modularity, high efficiency (approximately 100% yield in most cases) and tolerance toward many functional groups present in the fragments, as well as biocompatibility (typically carried out in aqueous conditions with small amounts of biocompatible catalysts). The approach consists of three steps: (i) chemical synthesis of alkyne-bearing protein tyrosine phosphatase or matrix metalloprotease core groups and diverse azide-modified peripheral groups; (ii) click chemistry to assemble the bidentate inhibitor libraries; and (iii) direct screening of the libraries with target enzymes using 384-well microplate assays. Following the chemical synthesis of the core and peripheral groups and optimization of the click chemistry conditions (approximately 1 week), steps (ii) and (iii) take 3 d to complete (approximately 1-2 d for library assembly and 1 d for inhibitor screening).

Are adrenomedullin positive modulators novel matrix metalloproteinase inhibitors?

Las metaloproteasas de la matriz (MMPs) pertenecen a la familia de enzimasque contienen zinc y juegan un papel predominante en la degradación del tejidoconectivo. Por ello se consideran dianas terapéuticas para procesos de inflamacióny enfermedades malignas y degenerativas. Por otro lado, se ha demostrado recientementeque un miembro de esta familia, MMP-2, una colagenasa de tipo IV tambiénconocida como gelatinasa A, es capaz de degradar un péptido angiogénico denominadoadrenomedulina (AM) (1). AM es una hormona peptídica que desarrolla unpapel importante en diversas patologías como diabetes, hipertensión y cáncer. Seha identificado mediante un cribado de alto rendimiento (HTS) de la colección decompuestos del Instituto Nacional del Cáncer (NCI), una serie de moduladores coninteresante actividad hipotensora (2). El mecanismo de acción de estos moduladoreses desconocido y nosotros proponemos que pueden afectar a la biodisponibilidadde la AM en el torrente sanguíneo por medio de la inhibición de la actividad dela MMP-2. En este trabajo presentamos un estudio teórico que hace uso de técnicascomo mecánica molecular, docking y Cribado Virtual con el objetivo de demostraresa hipótesis. A continuación del estudio computacional se llevó a cabo la evaluaciónbiológica de algunos compuestos, permitiéndonos proponer un nuevo tipo deZBG que puede ser interesante para el diseño de nuevos inhibidores de MMPS, coninterés como agentes anticancerosos y antiangiogénicos

Matrix metalloproteinases (MMPs), are a family of structurally related zinccontaining enzymes that play a major role in the breakdown of connective tissueand therefore, are targets for therapeutic inhibitors in many inflammatory,malignant, and degenerative diseases. On the other hand, it has been recentlydemonstrated that one of these enzymes, MMP-2, a type IV collagenase, termedgelatinase A, cleaves the angiogenic peptide adrenomedullin (AM) (1). AM is apeptide hormone that plays a critical role in several diseases such as diabetes,hypertension and cancer. In a High Throughput Screening (HTS) carried out at theNational Cancer Institute (NCI), a series of AM modulators were identified, with aninteresting hypotensive activity (2). In order to shed light into the mechanism ofaction of these interesting compounds, we have hypothesized that they may be affecting the biodisponibility of AM in the blood stream by inhibiting the MMP-2protease activity. In the present work, we present a theoretical study, making useof molecular mechanics, docking and virtual screening techniques, with the aim ofdemonstrating this hypothesis. Biological evaluation of MMP-2 inhibition by someselected compounds, followed the computational work, leading us to propose astructurally new type of MMP-2 inhibitors, with possible interest as anticancer andantiangiogenic agents

[Design, synthesis and activity evaluation of novel matrix metalloproteinases inhibitors based on the structure of enzyme].

A novel inhibitor series for matrix metalloproteinases (MMPs) were designed and synthesized. Using succinate and malonate as zinc binding groups and long hydrophobic substituents to bind with S1' pockets, the compounds showed micromolar inhibition and selectivity for MMP-2 over others. And we found a better activity compound. It is a chance to find a better precursor of MMP-2 inhibitors with activity and bioavailability by further optimization of compounds.

Efecto de condroitín sulfato y ácido hialurónico (500-730 kDa) sobre la síntesis de estromelisina (MMP-3) y MMP-1 en cultivo de condrocitos humanos / Effect of chondroitin sulfate and hyaluronic acid (500-730 kDa) on synthesis of stromelysin (MMP-3) and MMP-1 in human chondrocyte cultures

Introducción: El condroitín sulfato (CS) y el ácido hialurónico (AH) son fármacos que se utilizan para el tratamiento sintomático de la artrosis (AO). La colagenasa-1 (MMP-1) y la estromelisina-1 (MMP-3) son 2 enzimas proteolíticas encargadas de la degradación de la matriz extracelular en la AO. Pocos estudios han determinado el efecto in vitro de CS y AH sobre la síntesis de MMP-1 y de AH sobre la expresión de MMP-3 en cultivos de condrocitos humanos artrósicos, y en la bibliografía que se ha revisado no hay estudios que evalúen el efecto de CS sobre MMP-3. Objetivos: Analizar el efecto de CS y AH (500-730 kDa) sobre la síntesis de MMP-3 y MMP-1 inducida por interleucina 1â (IL-1â) en condrocitos artrósicos. Material y métodos: Los condrocitos se incubaron durante 48 h con IL-1â (2,5 ng/ml) en presencia o ausencia de diferentes concentraciones de AH (Hyalgan®, Bioibérica Farma) o CS (Condrosan®, Bioibérica Farma) (10, 50, 100, 150, 200 y 1.000 ìg/ml). La valoración funcional de los condrocitos se realizó mediante enzimoinmunoanálisis de los valores de MMP- 1 y MMP-3. Resultados: CS y AH inhiben la síntesis de MMP-3 inducida por IL-1â, sin afectar de forma significativa a los valores de MMP-1. CS y AH redujeron los valores de expresión de la MMP-3 a todas las concentraciones estudiadas, sin que se encontraran diferencias estadísticamente significativas entre dichas concentraciones. Conclusiones: Nuestro estudio demuestra por primera vez que CS inhibe la síntesis de MMP-3 en el cartílago artrósico y corrobora los escasos datos existentes sobre la capacidad de AH de inhibir dicha enzima(AU)

Introduction: Chondroitin sulfate (CS) and hyaluronic acid (HA) are used in the symptomatic treatment of osteoarthritis (OA). Cholagenase-1 (MMP-1) and stromelysin-1 (MMP-3), are responsible for degradation of the extracellular matrix in OA. Few studies have determined the in vitro effect of CS and HA on MMP-1 synthesis and that of HA on MMP-3 expression in human OA chondrocyte culture. In the literature reviewed, there were no studies evaluating the effect of CS on MMP-3. Objectives: To analyze the effect of CS and HA (500- 730 kDa) on MMP-3 and MMP-1 synthesis induced by interleukin-1â (IL-1â) in OA chondrocytes. Material and methods: Chondrocytes were incubated for 48 hours with IL-1â (2.5 ng/ml) in the presence or absence of different HA concentrations (Hyalgan®, Bioibérica Farma) (10, 50, 100, 150, 200 and 1000 ìg/ml). Functional evaluation of chondrocytes was performed by enzyme-immunoanalysis of MMP-1 and MMP-3 levels. Results: CS and HA inhibited IL-1â-induced MMP-3 synthesis, without significantly modifying MMP-1. CS and HA reduced levels of MMP-3 expression at all the studied concentrations, with no statistically significant differences among these concentrations. Conclusions: The results of this study show for the first time that CS inhibits MMP-3 synthesis in OA cartilage. and corroborates the few existing data on the ability of HA to inhibit this enzyme(AU)

Prevention of progressive joint destruction in collagen-induced arthritis in rats by a novel matrix metalloproteinase inhibitor, FR255031.

FR255031 (2-[(7S)-7-[5-(4-ethylphenyl)-2-thienyl]-1,1-dioxido-4-(2-pyridinylcarbonyl)hexahydro-1,4-thiazepin-7-yl]-N-hydroxyacetamide) is a novel synthetic matrix metalloproteinase (MMP) inhibitor that inhibits human collagenases (MMP-1, MMP-8 and MMP-13), gelatinases (MMP-2 and MMP-9) and membrane type 1 MMP (MT1-MMP/MMP-14). FR255031 also inhibits rat collagenase and gelatinase. We studied the effect of FR255031 and Trocade, an inhibitor of collagenase and MMP-14, on a rat collagen-induced arthritis (CIA) model. Rat CIA was induced by intradermal injection of type II collagen (IIC) and oral administration of FR255031 or Trocade was performed for 28 days. Body weight loss, hind paw swelling, elevation of serum anti-IIC antibody, and histological and radiographic scores were evaluated. FR255031 markedly inhibited cartilage degradation in a dose-dependent manner in the CIA model, but Trocade failed to prevent the degradation. FR255031 at a dose of 100 mg kg(-1) also had statistically significant effects on bone destruction and pannus formation and on the recovery of body weight loss on day 28. These results indicate that FR255031 is effective for rat CIA, especially on joint cartilage destruction. These data suggest that as well as collagenases or MT-MMP, gelatinases are also involved in joint destruction in arthritis.