MASP-2 saturation curve in cerebrospinal fluid indicates local synthesis and its equilibrium with soluble and associated forms / La curva de saturación de MASP-2 en líquido cefalorraquídeo indica síntesis local y su equilibrio con formas solubles y asociadas

Introduction: MASP-2 is a mannose blinding lectin associate to serine protease in cerebrospinal fluid and its dynamics through the blood brain barrier is unknown. Objective: To describe MASP-2 diffusion pattern from blood to cerebrospinal fluid. Methods: A transversal observational prospective study was performed 56 control samples of cerebrospinal fluid and serum were employed. ELISA measured MASP-2. Two groups were made: control patients without organic brain disease with normal cerebrospinal fluid and normal barrier function and patients without inflammatory diseases with a blood cerebrospinal fluid barrier dysfunction. Results: MASP-2 concentration in cerebrospinal fluid increase with augment the Q Albumin. QMASP-2 vs. Q Albumin saturation curve indicates that MASP-2 is interacting with other molecules in the subarachnoid environment. The higher inter-individual variation of cerebrospinal fluid MASP-2 of the control compared to the serum MASP-2 indicates that MASP-2 is a protein derived from blood. Conclusions: MASP-2 in CSF is predominantly blood-derived. The saturation curve demonstrates that MASP-2 interacts with the starters of the lectin pathway like mannose binding lectin, ficolins and collectin LK(AU)

Introducción: MASP2 es una proteína de unión a manosa asociada a una proteasa de serina encontrada en la periferia, pero puede pasar a líquido cefalorraquídeo. Sin embargo, su dinámica a través de la barrera sangre-líquido cefalorraquídeo es aún desconocida. Objetivo: Describir la difusión del MASP-2 desde la sangre al líquido cefalorraquídeo. Métodos: Se realiza estudio observacional prospectivo de corte transversal donde se emplearon 56 muestras de suero y líquido cefalorraquídeo. Fue seleccionado un grupo control con pacientes sin enfermedad orgánica del cerebro, con líquido cefalorraquídeo y función de barrera normal y otro grupo de pacientes sin enfermedades inflamatorias del cerebro con disfunción de barrera sangre-líquido cefalorraquídeo. Resultados: La concentración de MASP-2 en líquido cefalorraquídeo aumentó con el incremento de la Q Albúmina. La curva de saturación de Q MASP-2 contra la Q Albúmina indicó que el MASP-2 se encuentra interactuando con otras moléculas en el espacio subaracnoideo. El aumento del coeficiente de variación individual de MASP-2 en líquido cefalorraquídeo de los controles comparado con el MASP-2 en suero indicó que el MASP-2 es una proteína derivada de la sangre. Conclusiones: La producción de MASP-2 en líquido cefalorraquídeo es predominantemente derivada de la sangre. La curva de saturación demostró que el MASP-2 interactúa con los iniciadores de la vía de las lectinas como lectina unida a manosa, las ficolinas y la colectina LK(AU)

Vía de las lectinas, una ruta del complemento en construcción / Lectin pathway, a complement route under construction

ntroducción: El sistema del complemento puede ser activado por tres vías: clásica, alternativa y de las lectinas, esta última en fase de estudio para su completamiento. Objetivo: Describir hasta donde se ha avanzado en la construcción de la vía de las lectinas, sus iniciadores, activadores, reguladores, cascada enzimática y sus funciones biológicas. Metodología: Se realizó una revisión sobre el tema en estudio empleando artículos de libre acceso en la base de datos Pubmed y los trabajos publicados por el grupo de trabajo de la Universidad de Goettigen, la Universidad de Aarhus en Dinamarca y el Laboratorio Central de Líquido Cefalorraquídeo (LABCEL) de la Universidad de Ciencias Médicas de La Habana en los últimos cinco años comprendidos en el período de enero de 2012 a marzo del 2017. Desarrollo: Los iniciadores de la vía de las lectinas son las moléculas de reconocimiento colectinas y ficolinas circulantes en sangre, que participan en muchos procesos del organismo. Los activadores de esta vía son las MASP 1, 2 presentes como proenzimas; y la MASP 3, MAp 19 y 44 actúan como reguladoras. La cascada enzimática luego del reconocimiento es similar a la ruta clásica. Conclusiones: Las colectinas y ficolinas inician la vía de las lectinas. Sus activadores son las MASP 1, 2. Los reguladores son la MASP-3, y las MAp 19 y 44. Similar a la clásica en su cascada enzimática. Es la más antigua en la filogenia por eso participa en muchos procesos en el organismo(AU)

Introduction. The complement system can be activated in three ways: classical, alternative and lectins, the latter in the study phase for its completion. Objective. To describe the progress made in the construction of the lectin pathway, its initiators, activators, regulators, enzymatic cascade and its biological functions. Methods. A review was made on the subject under study using articles of free access in the Pubmed database and the works published by the working group of the University of Goettigen, the University of Aarhus in Denmark and the Central Laboratory of Cefalorraquìdeo liquid (LABCEL) of the University of Medical Sciences of Havana in the last five years included in the period from January 2012 to March 2017. Development. The initiators of the lectin pathway are the collectin recognition molecules and circulating ficolins in blood, which participate in many processes of the organism. The activators of this pathway are MASP 1, 2 present as proenzymes; and MASP 3, MAp 19 and 44 act as regulators. The enzymatic cascade after recognition is similar to the classical route. Conclusions. Collectins and ficolines initiate the lectin pathway. Its activators are MASP 1, 2. The regulators are MASP-3, and MAp 19 and 44. Similar to the classic in its enzymatic cascade. It is the oldest in phylogeny so it participates in many processes in the body.(AU)

Correlation among serum MBL, MASP-2, HsCRP and Clevels in rheumatoid arthritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the correlation among serum levels of manning-binding lectin (MBL), MBL-associated serine proteases-2 (MASP-2), complement Cand high-sensitive C reactive protein (HsCRP) in patients with rheumatoid arthritis (RA).</p><p><b>METHODS</b>Fasting venous blood were collected from 50 RA patients (25 in active stage and 25 in remission) and 40 healthy subjects for detecting serum levels of MBL, MASP-2, complement Cand HsCRP using enzyme-linked immunosorbent assay (ELISA) and immune turbidity assay.</p><p><b>RESULTS</b>The serum levels of MBL and MASP-2 were significantly lower and HsCRP level was significantly higher in patients with RA (in both acute stage and remission) than in the healthy control group (P<0.05), but complement Clevel was similar between the RA patients and control group. Bivariate Pearson correlation analysis showed that in RA patients, MBL was positively correlated with MASP-2 level (r=0.550, P=0.001) and negatively with HsCRP (r=-0.323, P=0.022) but not correlated with C(r=-0.022, P=0.882); MASP-2 was negatively correlated with HsCRP (r=0.453, P=0.453) and was not correlated with C(r=0.049, P=0.738). ROC curve analysis revealed the largest area under curve (AUC) of HsCRP (0.844, P=0.001) and smaller AUCs of MBL (0.025, P=0.001) and MASP-2 (0.266, P=0.001). HsCRP had a much higher sensitivity (84%) than MBL (10%) and MASP-2 (40%) in the diagnosis of RA.</p><p><b>CONCLUSION</b>In RA patients, MBL and MASP-2 are negatively correlated with HsCRP level. Serum MBL and MASP-2 levels decrease with the progression of joint injury in RA patients, suggesting their involvement in the pathological process of RA; but due to their low sensitivity, they are not appropriate indicators for evaluating the disease activity of RA.</p>

Plasma levels of mannan-binding lectin-associated serine protease 2 in children with upper respiratory tract infection / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the significance of plasma levels of mannan-binding lectin (MBL)-associated serine protease 2 (MASP2) in children with upper respiratory tract infection (URTI).</p><p><b>METHODS</b>A total of 103 children with URTI and 35 healthy children were examined for plasma levels of MASP2 and C-reactive protein (CRP). According to CRP levels, white blood cell count (WBC), stage of infection, and administration of treatments, the children with URTI were divided into the elevated CRP group (n=48) and the normal CRP group (n=54), elevated WBC group (n=61) and normal WBC group (n=40), the early stage of infection without treatment group (n=68) and mid-late stage of infection with treatment group (n=35).</p><p><b>RESULTS</b>Plasma MASP2 levels was significantly higher in URTI group than in the healthy control group (P<0.001) and showed a close correlation with age (r=0.302, P<0.01). Plasma MASP2 level was significantly correlated with CRP level in elevated CRP group (r=0.310, P<0.05) but not in normal CRP group (P>0.05), correlated with WBC in elevated WBC group (r=0.392, P<0.01) but not in normal WBC group (P>0.05), and was significantly higher in early stage infection without treatment group than in mid-late stage of infection with treatment group (P<0.01). MASP2, MBL2 and CRP genes had a common binding site for the transcription factor HNF-4α.</p><p><b>CONCLUSIONS</b>MASP2 may be an acute-phase protein, and its plasma level might serve as a new reference index in the diagnosis of URTI in children.</p>

Fibrosis severity and mannan-binding lectin [MBL]/MBL associated serine protease 1 [MASP-1] complex in HCV-infected patients

Mannan-binding lectin [MBL] is a collectin synthesised in the liver and secreted into the bloodstream. It binds micro-organisms via interactions with glycans on the target surface. Bound MBL subsequently activates MBL-associated serine protease proenzymes [MASPs]. Several studies have investigated the possible role for MBL in hepatitis C virus [HCV] infection by examining MBL levels and polymorphisms in relation to disease progression and in response to treatment. The aim of this study was to investigate the relation of the activity of MBL and MBL/MASP-1 complex in sera of patients with mild and severe chronic HCV infection and outcome of HCV infection. Serum level of MBL and functional assays for MBL/MASP-1 complex activity were assayed in sera of 80 patients with chronic HCV infection. Patients were divided into two groups according to the results of the liver biopsy, group I [40 HCV patients had mild hepatic fibrosis, Ishak fibrosis stages 0-1] and group II [40 HCV patients had severe hepatic fibrosis, Ishak fibrosis stages 5-6], in addition to 20 control subjects as group III. The analysis of the MBL/MASP-1 complex activity at 0, 3 and 6 months was performed in all patients. Serum levels of MBL and MBL/MASP-1 complex activity were higher in sera of patients with chronic HCV liver disease compared to those in control subjects. There was a correlation between the activity of the MBL/MASP-1 complex and the severity of fibrosis [P= 0.003]. MBL/MASP-1 complex activity was associated more significantly with severe fibrosis in comparison to MBL concentration. MBL and MBL/MASP-1 complex activities play a key role in first-line host defence mechanism against certain infectious agents including HCV infection. However, it is also likely that the role of MBL and MBL/MASP-1 complex activity extends beyond this restricted infection-related view in that it appears to be a key regulator of inflammation

Níveis séricos e polimorfismos gênicos da lectina ligadora de manose (MBL) e da serino protease associada à MBP (MASP)-2 em uma amostra da população brasileira / Mannose-binding lectin (MBL) and MBL associated serine protease (MASP)-2 serum levels and genetic polymorphisms in a Brazilian population sample

A Lectina Ligadora de Manose (MBL) é uma proteína que reconhece carboidratos na superfície microbiana levando à ativação do sistema complemento. Este processo é mediado por Serino Proteases tal como a MASP-2. O complexo MBL/MASP-2 é responsável pela formação da C3 convertase C4bC2b. Os níveis séricos de MBL e a MASP-2 (genes MBL2 e MASP-2, respectivamente) são geneticamente determinados, e podem ser influenciados pela presença de polimorfismos em um único nucleotídeo SNPs em genes codificadores destas proteínas. OBJETIVO: Determinar os níveis séricos e polimorfismos gênicos da MBL e MASP-2 em uma amostra da população brasileira. MÉTODOS: 294 amostras de doadores de sangue [mediana = 36,51 ± 10,56; 18-63 anos; 91/294 (30,95%) sexo feminino, 203/294 (69,05%) sexo masculino] foram genotipadas para os SNPs do éxon 1 (MBL2): SNPs localizados nos códons 52 (ArgCys), 54 (GlyAsp) e 57 (GlyGlu) e SNP Asp371Tyr (D371Y, A>C ) do gene da MASP-2 (éxon 9). Foi utilizado o ensaio de temperatura de dissociação para éxon 1 (MBL2) e sequenciamento direto dos promoters (H/L, X/Y e P/Q, nas posições -550, -221 e +4, respectivamente). A combinação das variantes do éxon 1 MBL2 foram agrupadas e denominadas alelo O e o genótipo selvagem foi denominado A. O éxon 9 da MASP-2 foi genotipado através da plataforma TaqMan. RESULTADOS: MBL2: 58,5% A/A, 36,39% A/O e 5,1% O/O; promoters: 13% H/H, 39% H/L, 48% L/L; 2% X/X, 26% X/Y, 72% Y/Y; 52% P/P, 37% P/Q, 11% Q/Q; haplótipos encontrados: 15% LXPA, 28% HYPA, 8% LYQO, 12% LYPO, 11% LYPA, 22% LYQA e 4% HYPO. Quanto à produção, 56,12% produziram altos níveis de MBL, 30,61% níveis médios e 13,27% níveis baixos ou insuficientes de MBL. Para MASP-2: 38,78% A/A, 44,56% A/C e 16,67% C/C. CONCLUSÃO: A prevalência (5,1%) SNP O/O do éxon 1 (MBL2) está de acordo com a literatura brasileira, é semelhante à européia (4%) e japonesa (5%), menor que a africana (10-14%). Níveis séricos de MBL corresponderam aos genótipos determinados. Esta é a...

BACKGROUND: Mannose-binding lectin (MBL) is a protein that recognizes carbohydrates on microbial surface leading to complement activation. This process is mediated by MBL-associated serine proteases, such as MASP-2. MBL/MASP-2 complex is responsible for generating the C3 convertase C4bC2b. Both MBL and MASP-2 levels are genetically determined, and can be influenced by the presence of single nucleotide polymorphisms (SNPs) in the genes encoding for these proteins (namely MBL2 and MASP-2). OBJTECTIVE: to determine MBL and MASP-2 serum levels and the frequencies of MBL2 and MASP-2 gene polymorphisms in a Brazilian population sample. METHODS: 294 blood donor samples [median age = 36.51 ± 10.56 years, range 18-63, 91/294 (31%) females and 203/294 (69%) males] were genotyped for MBL2 exon 1 SNPs: single point mutation in codon 52 (ArgCys), 54 (GlyAsp) and 57 (GlyGlu), and MASP-2 polymorphism Asp371Tyr (D371Y, A>C) (exon 9). A melting temperature assay was used to perform the genotyping of MBL2 SNPs. The combination of variants of MBL2 were grouped together as allele O, wild types were indicated as A. Exon 1 promoters were evaluated by direct genotype sequencing- alleles H/L, X/Y and P/Q (positions -550, -221 and +4, respectively). MASP-2 exon 9 genotyping was performed by using TaqMan pre-developed assay. RESULTS: MBL2: 58.5% A/A, 36.39% A/O, 5.1% O/O; promoters: 13% H/H, 39% H/L, 48% L/L; 2% X/X, 26% X/Y, 72% Y/Y; 52% P/P, 37% P/Q, 11% Q/Q; haplotypes: 15% LXPA, 28% HYPA, 8% LYQO, 12% LYPO, 11% LYPA, 22% LYQA and 4% HYPO. MASP-2: 38.78% A/A, 44.56% A/C and 16.67% C/C. CONCLUSION: The prevalence (5.1%) of O/O genotype of MBL2 exon 1 SNPs in our population is in accordance with Brazilian reports, similar to European (4%) and Japanese (5%); lower than Africans (10-14%). There is a correlation between MBL serum levels and genotyping. Moreover, this is the first report of D371Y MASP-2 polymorphism frequency in a Brazilian population. Our data may contribute to...

Specific interaction of hepatitis C virus glycoproteins with mannan binding lectin inhibits virus entry

Mannan-binding lectin (MBL) is a soluble innate immune protein that binds to glycosylated targets. MBL acts as an opsonin and activates complement, contributing to the destruction and clearance of infecting microorganisms. Hepatitis C virus (HCV) encodes two envelope glycoproteins E1 and E2, expressed as non-covalent E1/E2 heterodimers in the viral envelope. E1 and E2 are potential ligands for MBL. Here we describe an analysis of the interaction between HCV and MBL using recombinant soluble E2 ectodomain fragment, the full-length E1/E2 heterodimer, expressed in vitro, and assess the effect of this interaction on virus entry. A binding assay using antibody capture of full length E1/E2 heterodimers was used to demonstrate calcium dependent, saturating binding of MBL to HCV glycoproteins. Competition with various saccharides further confirmed that the interaction was via the lectin domain of MBL. MBL binds to E1/E2 representing a broad range of virus genotypes. MBL was shown to neutralize the entry into Huh-7 cells of HCV pseudoparticles (HCVpp) bearing E1/E2 from a wide range of genotypes. HCVpp were neutralized to varying degrees. MBL was also shown to neutralize an authentic cell culture infectious virus, strain JFH-1 (HCVcc). Furthermore, binding of MBL to E1/E2 was able to activate the complement system via MBL-associated serine protease 2. In conclusion, MBL interacts directly with HCV glycoproteins, which are present on the surface of the virion, resulting in neutralization of HCV particles.

Functional estimation of mannose binding lectin associated serine protease (MBL-MASPs) in human serum.

Background & objectives: Mannose binding lectin (MBL), a C-type or Ca2+ dependent lectin, plays a major role in lectin pathway of complement activation. MBL deficiency/insufficiency is associated with susceptibility to many infections. It is important to know the association of functional lectin levels with disease condition. Therefore, we carried out this study to develop a simple assay to estimate the functional MBL-associated serine proteases (MBL-MASPs) levels in human serum samples. Methods: A novel method was developed based on direct haemolysis of mannan coated human erythrocytes in autologous human serum for functional estimation of MBL and associated serine proteases (MBLMASPs complex). Functional MBL-MASPs serum levels in 75 healthy individuals was estimated. Results were compared with those obtained by ELISA based assay. Results: Lysis of mannan coated human RBC in autologous serum was highly specific and mediated by MBL-MASPs lectin complement pathway. Concentration of MBL-MASPs in serum of normal healthy individuals (n=75) was found to be 1.579 μg/ml (median= 1.149 μg/ml) by the haemolytic assay which was comparable to the values obtained by ELISA method. Interpretation & conclusions: Our findings showed that the method developed for the estimation of functional MBL-MASPs levels in human serum is simple, cost-effective and comparable with existing ELISA method.

Selección de cepas nativas con actividad quitino-proteolítica de bacillus sp aisladas de suelos tropicales / Selecting native Bacillus sp strains having chitinolytic and proteolytic activity which have been isolated from tropical soils

El objetivo de este trabajo fue la selección de cepas nativas del género Bacillus con actividad quitinolíticay proteolítica, en suelo tropical en la costa de Oaxaca, México. Se aislaron 150 cepas, de las cuales 22fueron seleccionadas por presentar actividad quitinolítica y proteolítica. Dicha actividad se evaluó porla formación de halo de hidrólisis alrededor de la colonia en medios de cultivo suplementados con quitinacoloidal al 5% y leche descremada al 1% respectivamente. Las cepas LUM B001, B003, B013, B015y B065 presentaron mayor actividad quitinolítica y proteolítica, por lo que tienen el potencial para serevaluadas en control biológico de hongos fitopatógenos. Se encontró al género Bacillus distribuido ensuelos cultivados y no cultivados, no se encontraron diferencias estadísticas según el cultivo establecido(P<0,05), sin embargo se encontraron diferencias significativas (P<0,05) entre las zonas estudiadas, correspondiendolas menores recuperaciones de cepas a los terrenos del municipio de Tututepec, Oaxaca.

This work was aimed at selecting native strains from the Bacillus genus having chitinolytic and proteolytic activityfrom soil from the tropical coast of Oaxaca, Mexico. 150 strains were isolated, 22 of which were selectedas they presented chitinolytic and proteolytic activity. Such activity was assessed by the formation of a hydrolysishalo around the colony in culture media supplemented with 5% colloidal chitin and 1% skimmed milk.The LUM B001, B003, B013, B015 and B065-chitin strains presented higher quitinolytic and proteolytic activity,thereby having the potential for being evaluated in the biological control of phytopathogenic fungi. TheBacillus genus was found in cultivated and uncultivated soils; no statistical differences were found accordingto established crop (p <0.05); however, significant differences (p <0.05) were found between the areas beingstudied regarding the smaller amount of strains collected from land in the municipality of Tututepec, Oaxaca.

Species and characteristics of protein adsorption on reused hemodialysis membranes / 生物医学工程学杂志

The aim of this study was to systemically analyze the proteins that adsorbed on the surface of hemodialysis membrane. The Fresenius F6 reused polysulfone dialyzers were selected as the research objects. The methodology we used encompassed the digestion of protein in rinsed solution and the separation of peptide mixture in virtue of RP-HPLC followed by ESI-MS/MS identification in orde to get their adsorption behavior, species and characteristics. The results illustrated that, after being rinsed by reverse osmosis (RO) water, 179 species of the protein adsorbed on the hemodialysis membrane, most of which were acidulous and middle or small weight protein molecules. The data from counting the numbers of peptides showed there were 5 species of high-abundant proteins (the contents being above 5% each), namely Ficolin-2 precursor, Complement C3 precursor (Fragment), Mannan-binding lectin serine protease 1 isoform 2 precursor, Complement-activating component of Ra-reactive factor precursor, and Mannan-binding lectin serine protease 1 isoform 3. These proteins are in close relationship with human immune system; moreover, they are of great significance to the clinical mechanism for cleaning reuse hemodialyzers and to the development of new hemodialysis materials.