Apo-Lactoferrin Inhibits the Proteolytic Activity of the 110 kDa Zn Metalloprotease Produced by Mannheimia haemolytica A2.

Mannheimia haemolytica is the main etiological bacterial agent in ruminant respiratory disease. M. haemolytica secretes leukotoxin, lipopolysaccharides, and proteases, which may be targeted to treat infections. We recently reported the purification and in vivo detection of a 110 kDa Zn metalloprotease with collagenase activity (110-Mh metalloprotease) in a sheep with mannheimiosis, and this protease may be an important virulence factor. Due to the increase in the number of multidrug-resistant strains of M. haemolytica, new alternatives to antibiotics are being explored; one option is lactoferrin (Lf), which is a multifunctional iron-binding glycoprotein from the innate immune system of mammals. Bovine apo-lactoferrin (apo-bLf) possesses many properties, and its bactericidal and bacteriostatic effects have been highlighted. The present study was conducted to investigate whether apo-bLf inhibits the secretion and proteolytic activity of the 110-Mh metalloprotease. This enzyme was purified and sublethal doses of apo-bLf were added to cultures of M. haemolytica or co-incubated with the 110-Mh metalloprotease. The collagenase activity was evaluated using zymography and azocoll assays. Our results showed that apo-bLf inhibited the secretion and activity of the 110-Mh metalloprotease. Molecular docking and overlay assays showed that apo-bLf bound near the active site of the 110-Mh metalloprotease, which affected its enzymatic activity.

Profile of extracellular matrix metalloproteinase in healthy and infected Toggenburg goats with small ruminant lentivirus in Southeast Brazil / Perfil das metaloproteínas de matriz extracelular em cabras Toggenburg sadias e infectadas por lentivírus de pequenos ruminantes no Sudeste brasileiro

Small ruminant lentiviruses (SRLV) are difficult to diagnose due to their escape mechanisms. Therefore, proteomics is an alternative in the search for biomarkers through extracellular matrix metalloproteinases (MMPs), enzymes related to the immune response. In this sense, this study aimed to analyze the profile of MMPs in healthy and infected Toggenburg goats with chronic SRLV infection in Southeast Brazil. Five positive and five negative goats for SRLV were selected using the agar gel immunodiffusion (AGID) microtechnique, western blot (WB), and nested polymerase chain reaction (nPCR). All animals were submitted to blood collection by puncture of the jugular vein, followed by centrifugation to obtain blood plasma, protein quantification by the Bradford method, one-dimensional electrophoretic separation (1D), and identification of protease activity by zymography and confirmation via reverse zymography in the presence of MMP-2 through the action of tissue inhibitors (TIMP-2). The analysis of protein bands was performed using descriptive statistics and densitometry values for zymography were subjected to the Shapiro-Wilk test to determine normality. Little difference was observed in the occurrence of protein bands between groups. Regarding MMPs, no differences were observed in the expression of proMMP-9, MMP-9, and MMP-2 in animals affected by SRLV. TIMP-2 inhibited proMMP-2 and MMP-2 in all animals. Thus, the profile of protein bands does not change in healthy goats with chronic SRLV infection. The TIMP-2 expression allowed proving the existence of MMP-2 in animals chronically infected by SRLV via reverse zymography

Lentivírus de pequenos ruminantes (LVPR) demonstram diagnóstico complexo devido seus mecanismos de escape. Desse modo, a proteômica apresenta-se como alternativa na busca por biomarcadores através das metaloproteinases da matriz extracelular (MMPs), enzimas ligadas a resposta imunológica. Assim, objetivou-se analisar o perfil das MMPs em cabras Toggenburg sadias e com infecção crônica por LVPR no Sudeste brasileiro. Selecionou-se cinco cabras positivas e cinco negativas para LVPR utilizando: microtécnica de imunodifusão em gel de agarose (MIDGA), Western Blot (WB) e reação em cadeia da polimerase nested (nPCR). Todas foram submetidas à coleta de sangue por punção da veia jugular, seguido de centrifugação para obtenção do plasma sanguíneo, quantificação proteica pelo método Bradford, separação via eletroforese unidimensional (1D), e identificação da atividade das proteases por zimografia e confirmação via zimografia reversa na presença da MMP-2 por meio da ação de inibidores teciduais (TIMP-2). A análise das bandas proteicas ocorreu através de estatística descritiva e para a zimografia os valores de densitometria foram submetidos ao teste de Shapiro-Wilk para determinar a normalidade. Observou-se pouca distinção na ocorrência das bandas proteicas entre os grupos. Em relação as MMPs, não houve diferenças na expressão da proMMP-9, MMP-9 e MMP-2 nos acometidos por LVPR. Observou-se que a TIMP-2 inibiu a proMMP-2 e MMP-2 em todos os animais. Dessa forma, o perfil de bandas proteicas não se altera em cabras sadias e com infecção crônica por LVPR. Através da expressão da TIMP-2 foi possível comprovar a existência da MMP-2 em animais cronicamente infectados por LVPR via zimografia reversa

Dental Adhesives-Surface Modifications of Dentin Structure for Stable Bonding.

The latest advancements in dentin bonding have focused on strategies to impair degradation mechanisms in order to extend the longevity of bonded interfaces. Protease inhibitors can reduce collagen degradation within the hybrid layer (HL). Collagen cross-linkers allow better adhesive infiltration and also inhibit proteases activity. Particles added to adhesive can promote mineral precipitation within the HL, reducing nanoleakage and micropermeability, besides possible antimicrobial and enzymatic inhibition effects. Most of these approaches are still experimental, and aspects of the adhesive under the clinician's control are still determinant for the long-term stability of adhesive restorations.

Two-Dimensional Blue Native/SDS Polyacrylamide Gel Electrophoresis for Analysis of Brazilian Bothrops Snake Venoms.

Viperidae snakes are the most important agents of snakebites in Brazil. The protein composition of snake venoms has been frequently analyzed by means of electrophoretic techniques, but the interaction of proteins in venoms has barely been addressed. An electrophoretic technique that has gained prominence to study this type of interaction is blue native polyacrylamide gel electrophoresis (BN-PAGE), which allows for the high-resolution separation of proteins in their native form. These protein complexes can be further discriminated by a second-dimension gel electrophoresis (SDS-PAGE) from lanes cut from BN-PAGE. Once there is no study on the use of bidimensional BN/SDS-PAGE with snake venoms, this study initially standardized the BN/SDS-PAGE technique in order to evaluate protein interactions in Bothrops atrox, Bothrops erythromelas, and Bothrops jararaca snake venoms. Results of BN/SDS-PAGE showed that native protein complexes were present, and that snake venom metalloproteinases and venom serine proteinases maintained their enzymatic activity after BN/SDS-PAGE. C-type lectin-like proteins were identified by Western blotting. Therefore, bidimensional BN/SDS-PAGE proved to be an easy, practical, and efficient method for separating functional venom proteins according to their assemblage in complexes, as well as to analyze their biological activities in further details.

Proteolytic Activity Assays in Haloarchaea.

Extreme halophilic archaea (haloarchaea) have adapted their physiology and biomolecules to thrive in saline environments (>2 M NaCl). Many haloarchaea produce extracellular hydrolases (including proteases) with potential biotechnological applications, which require unusual high salt concentrations to attain their function and maintain their stability. These conditions restrict many of the standard methods used to study these enzymes such as activity determination and/or protein purification. Here, we describe basic protocols to detect and measure extracellular proteolytic activity in haloarchaea including casein hydrolysis on agar plates, quantitative proteolytic activity determination by the azocasein assay and gelatin zymography in presence of the compatible solute glycine-betaine.

Phosphoric acid containing proanthocyanidin enhances bond stability of resin/dentin interface

Abstract Proanthocyanidin (PA) is a promising dentin biomodifier due to its ability to stabilize collagen fibrils against degradation by matrix metalloproteinases (MMPs); however, the most effective protocol to incorporate PA into bonding procedures is still unclear. This study evaluated the effect of dentin biomodification with a PA acid etchant on MMP activity, adhesive interface morphology and resin-dentin microtensile bond strength. Sound extracted human molars were flattened to expose dentin and acid-etched for 15 s according to the groups: EXP - experimental phosphoric acid; EXP+PA - experimental phosphoric acid 10% PA; TE - total-etching system; SE - self-etching system. Samples were restored with composite resin and stored in distilled water (37ºC). MMP activity and interface morphology were analyzed after 24 h by in situ zymography (n=6) and scanning electron microscopy (n=3), respectively. The resin-dentin microtensile bond strength (μTBS) was evaluated after 24 h and 6 months storage (n=6). Significantly higher MMP activity was detected in etched dentin compared with untreated dentin (p<0.05), but no difference among acid groups was found. Resin tags and microtags, indicative of proper adhesive system penetration in dentinal tubules and microtubules, were observed along the hybrid layer in all groups. There was no difference in μTBS between 24 h and 6 months for EXP+PA; moreover, it showed higher long-term μTBS compared with TE and EXP (p<0.05). The results suggest that 15 s of biomodification was not sufficient to significantly reduce MMP activity; nonetheless, EXP+PA was still able to improve resin-dentin bond stability compared with total- and self-etching commercial systems.

Resumo A proantocianidina (PA) é um biomodificador dentinário promissor devido a sua capacidade de estabilizar as fibrilas colágenas contra a degradação por metaloproteinases da matriz (MMPs); no entanto, o protocolo mais eficaz para a incorporação de PA em procedimentos adesivos ainda não está claro. Este estudo avaliou o efeito da biomodificação da dentina com um condicionador ácido contendo PA na atividade de MMPs, morfologia da interface adesiva e resistência à microtração resina-dentina. Molares humanos extraídos foram lixados para exposição da dentina e condicionados com ácido por 15 s de acordo com os grupos: EXP - ácido fosfórico experimental; EXP+PA - ácido fosfórico experimental com 10% PA; TE - sistema total-etch; SE - sistema self-etch. As amostras foram restauradas com resina composta e armazenadas em água destilada (37ºC). A atividade de MMP e morfologia da interface foram analisadas após 24 h por zimografia in situ (n=6) e microscopia eletrônica de varredura (n=3), respectivamente. A resistência à microtração resina-dentina (μTBS) foi avaliada após 24 horas e 6 meses de armazenamento (n=6). Atividade de MMP detectada na dentina condicionada foi significativamente maior em comparação com a dentina não tratada (p <0,05), mas não houve diferenças entre os diferentes ácidos. Tags e microtags de resina, indicativos de uma penetração adequada do sistema adesivo nos túbulos e microtúbulos dentinários, foram observadas ao longo da camada híbrida em todos os grupos. Não houve diferença entre os valores de μTBS de 24 h e 6 meses para EXP+PA; além disso, EXP+PA apresentou maiores valores de μTBS após 6 meses em comparação com TE e EXP (p <0,05). Os resultados sugerem que a biomodificação por 15 s não foi suficiente para reduzir significativamente a atividade de MMP; apesar disso, EXP + PA foi capaz de melhorar a estabilidade da interface resina-dentina em comparação com sistemas total- e self-etch comerciais.

The Influence of Different Bleaching Protocols on Dentinal Enzymatic Activity: An In Vitro Study.

This study aimed to investigate matrix metalloproteinase (MMP) activity in human dentin using in-situ and gelatin zymography, after at-home and in-office bleaching, related to their clinical exposure times. Dentin specimens (n = 5) were treated with 35% hydrogen peroxide (50 min per session/4 sessions), 10% carbamide peroxide (180 min/21 sessions), or no treatment. All were subjected to in-situ zymography. Dentin slices were, subsequently, obtained, covered with fluorescein-conjugated gelatin, and examined with confocal laser-scanning microscopy. The fluorescence intensity was quantified and statistically analyzed using one-way ANOVA and Bonferroni tests (α = 0.05). Furthermore, gelatin zymography was performed on protein extracts obtained from dentin powder (N = 8 teeth), treated with hydrogen peroxide or carbamide peroxide, with different exposure times (10/50 min for hydrogen peroxide; 252/1260 min for carbamide peroxide). The results of the in-situ zymography showed no statistical differences between the bleached specimens and the control group, with a medium level of gelatinolytic activity expressed in the dentin tubules. The results of gelatin zymography showed an increased expression of pro-MMP-9 in carbamide peroxide groups. The expression of pro-MMP-2 decreased in all the experimental groups. The bleaching treatments performed on the enamel of sound teeth do not influence dentinal enzymatic activity. However, when unprotected dentin tissue is bleached, matrix metalloproteinases are more expressed, particularly when carbamide peroxide is used, proportional to the exposure time.

Two-dimensional blue native/SDS polyacrylamide gel electrophoresis for analysis of Brazilian Bothrops snake venoms

Viperidae snakes are the most important agents of snakebites in Brazil. The protein composition of snake venoms has been frequently analyzed by means of electrophoretic techniques, but the interaction of proteins in venoms has barely been addressed. An electrophoretic technique that has gained prominence to study this type of interaction is blue native polyacrylamide gel electrophoresis (BN-PAGE), which allows for the high-resolution separation of proteins in their native form. These protein complexes can be further discriminated by a second-dimension gel electrophoresis (SDS-PAGE) from lanes cut from BN-PAGE. Once there is no study on the use of bidimensional BN/SDS-PAGE with snake venoms, this study initially standardized the BN/SDS-PAGE technique in order to evaluate protein interactions in Bothrops atrox, Bothrops erythromelas, and Bothrops jararaca snake venoms. Results of BN/SDS-PAGE showed that native protein complexes were present, and that snake venom metalloproteinases and venom serine proteinases maintained their enzymatic activity after BN/SDS-PAGE. C-type lectin-like proteins were identified by Western blotting. Therefore, bidimensional BN/SDS-PAGE proved to be an easy, practical, and efficient method for separating functional venom proteins according to their assemblage in complexes, as well as to analyze their biological activities in further details.

Bovine apo-lactoferrin affects the secretion of proteases in Mannheimia haemolytica A2.

Mannheimia haemolytica serotype A2 is the main bacterial causative agent of ovine mannheimiosis, a disease that leads to substantial economic losses for livestock farmers. Several virulence factors allow M. haemolytica to colonize the lungs and establish infection. Virulence factors can be directly secreted into the environment by bacteria but are also released through outer membrane vesicles (OMVs). In addition, due to the abuse of antibiotics in the treatment of this disease, multidrug-resistant bacterial strains of M. haemolytica have emerged. One therapeutic alternative to antibiotics or an adjuvant to be used in combination with antibiotics could be lactoferrin (Lf), a multifunctional cationic glycoprotein of the mammalian innate immune system to which no bacterial resistance has been reported. The aim of this work was to determine the effect of bovine iron-free Lf (apo-BLf) on the production and secretion of proteases into culture supernatant (CS) and on their release in OMVs. Zymography assays showed that addition of sub-MIC concentrations of apo-BLf to M. haemolytica cultures inhibited protease secretion without affecting culture growth. Biochemical characterization revealed that these proteases were mainly cysteine- and metalloproteases. The secretion of a 100 kDa metalloprotease was inhibited by sub-MIC concentrations of apo-BLf since this protease was present in the cytoplasm and OMVs but not in CS proteins, as corroborated by Western blotting. On the other hand, proteases produced by M. haemolytica caused cleavage of apo-BLf. However, when Lf is cleaved, peptides known as lactoferricins, which are more bactericidal than natural Lf, can be produced. M. haemolytica A2 protease-mediated degradation of host tissue proteins could be an important virulence factor during the infectious process of pneumonia in ovines. The mechanism of M. haemolytica protease secretion could be inhibited by treatment with apo-BLf in animals.

Exploring the Milk-Clotting and Proteolytic Activities in Different Tissues of Vallesia glabra: a New Source of Plant Proteolytic Enzymes.

Proteolytic enzymes are widely distributed in nature, playing essential roles in important biological functions. Recently, the use of plant proteases at the industrial level has mainly increased in the food industry (e.g., cheesemaking, meat tenderizing, and protein hydrolysate production). Current technological and scientific advances in the detection and characterization of proteolytic enzymes have encouraged the search for new natural sources. Thus, this work aimed to explore the milk-clotting and proteolytic properties of different tissues of Vallesia glabra. Aqueous extracts from the leaves, fruits, and seeds of V. glabra presented different protein profiles, proteolytic activity, and milk-clotting activity. The milk-clotting activity increased with temperature (30-65 °C), but this activity was higher in leaf (0.20 MCU/mL) compared with that in fruit and seed extracts (0.12 and 0.11 MCU/mL, respectively) at 50 °C. Proteolytic activity in the extracts assayed at different pH (2.5-12.0) suggested the presence of different types of active proteases, with maximum activity at acidic conditions (4.0-4.5). Inhibitory studies indicated that major activity in V. glabra extracts is related to cysteine proteases; however, the presence of serine, aspartic, and metalloproteases was also evident. The hydrolytic profile of caseins indicated that V. glabra leaves could be used as a rennet substitute in cheesemaking, representing a new and promising source of proteolytic enzymes.

Comparison of Single-Step Methods to Enrich Lipase Concentrations in Bacterial Cell Lysates

Abstract Lipases are currently used in food technology for the modification of fats and oils. The thermal stability of lipase is an essential characteristic for this application. This study compares four individual single-step methods (heat treatment, ethanol precipitation, ammonium sulfate precipitation, and size-exclusion chromatography) to enrich lipase concentrations from thermophilic bacterial (Geobacillius stearothermophilus and Anoxybacillus flavithermus) cell lysates. SDS-PAGE and size exclusion chromatography were used to determine the molecular weights of the lipases and the enrichment efficiencies were determined using specific enzyme activities. The molecular weight of G. stearothermophilus lipase was approximately 42 kDa, and approximately 33 kDa for A. flavithermus lipase. For each organism, ethanol precipitation resulted in the highest enrichment fold, followed by ammonium sulfate precipitation, gel filtration and heat treatment respectively. The highest yields for G. stearothermophilus lipase were obtained with ammonium sulfate precipitation, followed by get filtration, and ethanol precipitation respectively. The highest yields for A. flavithermus lipase were obtained from heat treatment followed by ammonium sulfate precipitation, gel filtration and ethanol precipitation respectively. Ethanol precipitation and heat treatment are simple methods for enzyme enrichment from cell lysates and can result in high enzyme yields with moderate enrichment folds compared to complex multi-step purification methods.

Extraction, Partial Purification and Characterization of Bromelain from Pineapple (Ananas Comosus) Crown, Core and Peel Waste

Abstract Ananas Comosus (also known as pineapple) is a part of Bromeliaceae family and it is consumed as food as well as folk medicine for the treatment of various diseases. It is reported that pineapple is a rich source of bromelain, a cysteine protease and it is considered as an important enzyme in different industries due to its significant therapeutic and industrial applications such as anticancer, anti-inflammatory and meat tenderizing. Bromelain is mostly present in fruit and stem of pineapple, but it is reported that crown, core, and peels, which constitute the waste of the pineapple plant, also contain bromelain but limited data is available. Therefore, the proposed study aimed at utilizing pineapple waste for the extraction and characterization of bromelain. Firstly, crude bromelain was extracted with phosphate buffer (pH 7), then it was subjected to partial purification using different fractions of ammonium sulphate (NH4)2SO4 such as 30, 40, 50 and 60% followed by desalting and concentration. Enzyme activity was calculated by using casein digesting unit (CDU) method. The results demonstrated that the crown bromelain showed highest purification of 4.34-fold at 30% (NH4)2SO4 saturation, whereas core and peel bromelain showed highest purification of 2.75 and 2.59-fold at 40% (NH4)2SO4 saturation. The molecular weight of crude and partially purified bromelain was determined by SDS-PAGE analysis and found to be 26 KDa. The pH and thermal stability of all the parts of pineapple showed maximum stability at pH 7 and at 35oC temperature.

Study of metalloproteinases in the blood of goats experimentally infected with caprine encephalitis arthritis virus / Estudo de metaloproteinases no sangue de caprinos experimentalmente infectados pelo vírus da artrite encefalite caprina

Caprine arthritis encephalitis is a lentiviral disease that leads to considerable losses in goat farming. In the acute phase of viral infection, though antiviral antibodies are produced by the host's immune system, they are not sufficient to be detected by serological tests. Acute infections begin with an incubation period, during which the viral genome replicates and host innate responses are initiated. Matrix metalloproteinases (MMPs) are enzymes that play an important role in the physiological and pathological processes of tissue remodeling. The present study aimed to evaluate the expression of MMPs and their activity in the blood serum of male goats experimentally infected with caprine arthritis encephalitis virus (CAEV). Five dairy male goats, aged 3-4 years, were intravenously inoculated with CAEV Cork strain (titer: 105-6 TCID50/mL) after being tested negative for CAEV thrice at consecutive intervals of 30 days using western blot analysis and nested-PCR. The study included three stages: S1 or pre-infection stage; S2 or seroconversion stage, corresponding to the occurrence of first seroconversion; and S3 or post-seroconversion stage, corresponding to 23 weeks after seroconversion. Zymography was performed for the samples using gelatin zymography gels (12.5%), which were subjected to electrophoresis at 170V, 1A, and 300W for 50-70 min. The density of MMP-2 was found to be lower at S1 (1456.20 pixels) than that at S2 and S3 (1943.80 and 2104.40 pixels, respectively) (P < 0.05); and the density of MMP-9 was found to be lower at S3 (133.60 pixels) than that at S1 and S2 (359.60 and 370.60 pixels, respectively). The density of proMMP-2 was low at S1 and S3 (130.45 and 145.20 pixels, respectively). On the other hand, the density of proMMP-9 was statistically different between S1 and S3 (89.22 vs. 415.60 pixels). Both proMMP-2 and proMMP-9 were absent at S2. Thus, MMP-2 and MMP9 exhibited opposite behaviors depending on the stage [...].(AU)

A encefalite por artrite caprina é uma doença lentiviral que leva a perdas consideráveis na criação de caprinos. Na fase aguda da infecção viral, embora os anticorpos antivirais sejam produzidos pelo sistema imunológico do hospedeiro, eles não são suficientes para serem detectados por testes sorológicos. As infecções agudas começam com um período de incubação, durante o qual o genoma viral se replica e as respostas inatas do hospedeiro são iniciadas. As metaloproteinases da matriz (MMPs) são enzimas que desempenham um papel importante nos processos fisiológicos e patológicos da remodelação tecidual. O presente estudo teve como objetivo avaliar a expressão de MMPs e sua atividade no soro sanguíneo de reprodutores caprinos infectados experimentalmente pelo vírus da encefalite por artrite caprina(CAEV). Cinco machos caprinos, com idades entre 3-4 anos, foram inoculadas por via intravenosa com a cepa de CAEV Cork (título: 105-6 TCID50/mL) após serem testados negativamente para CAEV três vezes em intervalos consecutivos de 30 dias usando a análise de western blot e nested-PCR. O estudo incluiu três etapas: estágio S1 ou pré-infecção; S2 ou estágio de soroconversão, correspondente à ocorrência de primeira soroconversão; e S3 ou pós-soroconversão, correspondendo a 23 semanas após a soroconversão. A zimografia foi realizada para as amostras utilizando gel de gelatina (12,5%), que foram submetidos à eletroforese em 170V, 1A e 300W por 50-70 min. Verificou-se que a densidade de MMP-2era menor em S1 (1456,20 pixels) do que em S2 e S3 (1943,80 e 2104,40 pixels, respectivamente) (P <0,05); e a densidade de MMP-9 foi menor em S3 (133,60 pixels) do que em S1 e S2 (359,60 e 370,60 pixels, respectivamente). A densidade do proMMP-2 era baixa em S1 e S3 (130,45 e 145,20 pixels, respectivamente). Por outro lado, a densidade do proMMP-9 foi estatisticamente diferente entre S1 e S3(89,22 vs. 415,60 pixels). ProMMP-2 e proMMP-9 estavam ausentes no S2. Assim, MMP-2 e [...].(AU)

Study of metalloproteinases in the blood of goats experimentally infected with caprine encephalitis arthritis virus / Estudo de metaloproteinases no sangue de caprinos experimentalmente infectados pelo vírus da artrite encefalite caprina

Caprine arthritis encephalitis is a lentiviral disease that leads to considerable losses in goat farming. In the acute phase of viral infection, though antiviral antibodies are produced by the host's immune system, they are not sufficient to be detected by serological tests. Acute infections begin with an incubation period, during which the viral genome replicates and host innate responses are initiated. Matrix metalloproteinases (MMPs) are enzymes that play an important role in the physiological and pathological processes of tissue remodeling. The present study aimed to evaluate the expression of MMPs and their activity in the blood serum of male goats experimentally infected with caprine arthritis encephalitis virus (CAEV). Five dairy male goats, aged 3-4 years, were intravenously inoculated with CAEV Cork strain (titer: 105-6 TCID50/mL) after being tested negative for CAEV thrice at consecutive intervals of 30 days using western blot analysis and nested-PCR. The study included three stages: S1 or pre-infection stage; S2 or seroconversion stage, corresponding to the occurrence of first seroconversion; and S3 or post-seroconversion stage, corresponding to 23 weeks after seroconversion. Zymography was performed for the samples using gelatin zymography gels (12.5%), which were subjected to electrophoresis at 170V, 1A, and 300W for 50-70 min. The density of MMP-2 was found to be lower at S1 (1456.20 pixels) than that at S2 and S3 (1943.80 and 2104.40 pixels, respectively) (P < 0.05); and the density of MMP-9 was found to be lower at S3 (133.60 pixels) than that at S1 and S2 (359.60 and 370.60 pixels, respectively). The density of proMMP-2 was low at S1 and S3 (130.45 and 145.20 pixels, respectively). On the other hand, the density of proMMP-9 was statistically different between S1 and S3 (89.22 vs. 415.60 pixels). Both proMMP-2 and proMMP-9 were absent at S2. Thus, MMP-2 and MMP9 exhibited opposite behaviors depending on the stage [...].

A encefalite por artrite caprina é uma doença lentiviral que leva a perdas consideráveis na criação de caprinos. Na fase aguda da infecção viral, embora os anticorpos antivirais sejam produzidos pelo sistema imunológico do hospedeiro, eles não são suficientes para serem detectados por testes sorológicos. As infecções agudas começam com um período de incubação, durante o qual o genoma viral se replica e as respostas inatas do hospedeiro são iniciadas. As metaloproteinases da matriz (MMPs) são enzimas que desempenham um papel importante nos processos fisiológicos e patológicos da remodelação tecidual. O presente estudo teve como objetivo avaliar a expressão de MMPs e sua atividade no soro sanguíneo de reprodutores caprinos infectados experimentalmente pelo vírus da encefalite por artrite caprina(CAEV). Cinco machos caprinos, com idades entre 3-4 anos, foram inoculadas por via intravenosa com a cepa de CAEV Cork (título: 105-6 TCID50/mL) após serem testados negativamente para CAEV três vezes em intervalos consecutivos de 30 dias usando a análise de western blot e nested-PCR. O estudo incluiu três etapas: estágio S1 ou pré-infecção; S2 ou estágio de soroconversão, correspondente à ocorrência de primeira soroconversão; e S3 ou pós-soroconversão, correspondendo a 23 semanas após a soroconversão. A zimografia foi realizada para as amostras utilizando gel de gelatina (12,5%), que foram submetidos à eletroforese em 170V, 1A e 300W por 50-70 min. Verificou-se que a densidade de MMP-2era menor em S1 (1456,20 pixels) do que em S2 e S3 (1943,80 e 2104,40 pixels, respectivamente) (P <0,05); e a densidade de MMP-9 foi menor em S3 (133,60 pixels) do que em S1 e S2 (359,60 e 370,60 pixels, respectivamente). A densidade do proMMP-2 era baixa em S1 e S3 (130,45 e 145,20 pixels, respectivamente). Por outro lado, a densidade do proMMP-9 foi estatisticamente diferente entre S1 e S3(89,22 vs. 415,60 pixels). ProMMP-2 e proMMP-9 estavam ausentes no S2. Assim, MMP-2 e [...].

Bioactive glass-ceramic bone repair associated or not with autogenous bone: a study of organic bone matrix organization in a rabbit critical-sized calvarial model.

OBJECTIVE: The aim of the study was to analyze bone matrix (BMX) organization after bone grafting and repair using a new bioactive glass-ceramic (Biosilicate®) associated or not with particulate autogenous bone graft. MATERIAL AND METHODS: Thirty rabbits underwent surgical bilateral parietal defects and divided into groups according to the materials used: (C) control-blood clot, (BG) particulate autogenous bone, (BS) bioactive glass-ceramic, and BG + BS. After 7, 14, and 30 days post-surgery, a fragment of each specimen was fixed in - 80 °C liquid nitrogen for zymographic evaluation, while the remaining was fixed in 10% formalin for histological birefringence analysis. RESULTS: The results of this study demonstrated that matrix organization in experimental groups was significantly improved compared to C considering collagenous organization. Zymographic analysis revealed pro-MMP-2, pro-MMP-9, and active (a)-MMP-2 in all groups, showing gradual decrease of total gelatinolytic activity during the periods. At day 7, BG presented more prominent gelatinolytic activity for pro-MMP-2 and 9 and a-MMP-2, when compared to the other groups. In addition, at day 7, a 53% activation ratio (active form/[active form + latent form]) was evident in C group, 33% in BS group, and 31% in BG group. CONCLUSION: In general, BS allowed the production of a BMX similar to BG, with organized collagen deposition and MMP-2 and MMP-9 disponibility, permitting satisfactory bone remodeling at the late period. CLINICAL RELEVANCE: The evaluation of new bone substitute, with favorable biological properties, opens the possibility for its use as a viable and efficient alternative to autologous bone graft.

Characterization of metalloproteases and serine proteases of Toxoplasma gondii tachyzoites and their effect on epithelial cells.

Toxoplasma gondii can infect all nucleated cells from warm-blooded organisms. After infection, Toxoplasma spreads throughout the body and migrates across biological barriers, such as the intestinal and blood-brain barriers, as well as the placenta in pregnant women. The mechanisms for parasite dissemination are still unknown; however, proteases could play a role as a virulence factor. The aim of this study was to detect and to characterize proteases in whole-cell extracts and in excretion/secretion products from tachyzoites of the RH strain isolated from infected mice. Both fractions were analyzed by gelatin and casein zymography and by azocasein degradation. The biochemical characterization of proteases included standardization of optimal conditions for their activation, such as pH, the presence of cofactors, and a reducing agent. In both fractions, we detected at least nine gelatin-degrading metalloproteases in the range of 50 to 290 kDa. The proteases present in the excretion/secretion products were found as soluble proteins and not associated with exosome-like vesicles or other secretory vesicles. Moreover, by using casein zymography, it was possible to detect three serine proteases. Exposure of MDCK cells to excretion/secretion products modified the organization of the cell monolayer, and this effect was reverted after washing thoroughly with PBS and inhibition by metalloprotease and serine protease inhibitors. Proteomic analysis of excretion/secretion products identified 19 proteases. These findings suggest that tachyzoites of a highly virulent strain of Toxoplasma use a battery of proteases to modify the epithelium, probably as a strategy to facilitate their tissue dissemination.

Expression of matrix metalloproteinase-2 and metalloproteinase-9 in the skin of dogs with visceral leishmaniasis.

The skin is the first organ to be infected by the parasite in canine visceral leishmaniasis. The enzyme matrix metalloproteinase (MMP) acts towards degradation of the extracellular matrix (ECM) and modulation of the inflammatory response against many kinds of injuries. The aims of this study were to evaluate the expression of MMP-2 and MMP-9 through immunohistochemistry and zymography on the skin (muzzle, ears, and abdomen) of dogs that were naturally infected by Leishmania spp. and to compare these results with immunodetection of the parasite and with alterations to the dermal ECM. Picrosirius red staining was used to differentiate collagen types I and III in three regions of the skin. The parasite load, intensity of inflammation, and production of MMP-2 (latent) and MMP-9 (active and latent) were higher in the ear and muzzle regions. MMP-9 (active) predominated in the infected group of dogs and its production was significantly different to that of the control group. Macrophages, lymphocytes, and plasma cells predominated in the dermal inflammation and formed granulomas in association with degradation of mature collagen (type I) and with discrete deposition of young collagen (type III). This dermal change was more pronounced in dogs with high parasite load in the skin. Therefore, it was concluded that the greater parasite load and intensity of inflammation in the skin led consequently to increased degradation of mature collagen, caused by increased production of MMPs, particularly active MMP-9, in dogs with visceral leishmaniasis. This host response profile possibly favors systemic dissemination of the parasite.

Water-associated attributes in the contemporary dentin bonding milieu.

OBJECTIVES: The water-associated attributes of resin-dentin interfaces created by contemporary adhesives are important determinants of bond integrity and stability. In the present work, these attributes were estimated from the perspectives of causality, to examine the behavior of the first and most-recently launched versions of universal adhesives when applied in either the etch-and-rinse mode or the self-etch mode. METHODS: The immediate cause of interfacial permeability and the time-dependent cause of water sorption were investigated in conjunction with the intermediate effect of interface degradation and the more long-term effect of loss of mechanical strength, before and after thermomechanical cycling. The results were compared with control etch-and-rinse and self-etch adhesives. RESULTS: Although the introduction of this new class of universal adhesives has brought forth significant changes to the dental adhesion arena, including more application options, reduced bonding armamentarium and increased user friendliness, the water-associated attributes that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large, when compared with benchmarks established by former classes of adhesives. CONCLUSION: It appears that the current trend of adhesive development has brought forth significant changes but lacks the vigor that demarcates progress and technological sublimity. CLINICAL SIGNIFICANCE: The advent of the user friendly universal adhesives has brought forth significant changes to the dental adhesion arena. However, the elements that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large.

Cloning and Characterization of a Novel N-acetylglucosaminidase (AtlD) from Enterococcus faecalis.

The atlD gene from an Enterococcus faecalis strain isolated from a Mexican artisanal cheese was cloned, sequenced and expressed in Escherichia coli in order to perform a biochemical characterization. A partial amino acid sequence of the heterologous protein was obtained by LC-MS/MS, and it corresponded to a novel peptidoglycan hydrolase designated AtlD. Its molecular mass was 62-75 kDa, as determined by SDS-PAGE, zymography, Western blot, and exclusion chromatography. Electrofocusing rendered an isoelectric point (pI) of 4.8. It exhibited N-acetylglucosaminidase activity, with an optimal pH and temperature between 6-7 and 50°C, respectively. It retained 85% activity with NaCl at 1,000 mM, but it was susceptible to divalent ions, particularly Zn2+. It showed antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and enterococcal strains of clinical origin. Due to the fact that it showed activity versus pathogenic bacteria, and because of its capabilities under ionic strength, temperature, and pH values present in food matrices, it could be applied as an additive in the food industry. This study will aid in the design of new antibacterial agents of natural origin to combat food-borne diseases, and it could be used as an industrial or hospital hygiene agent as well.