RESUMO
Pseudomonas aeruginosa is an opportunistic bacterium that can form a biofilm with the ability to colonize different surfaces and for increasing resistance to antibiotics. An alternative to solve this problem may be the use of non-glucose/mannose glycosylated proteins from Melipona beecheii honey, which are capable of inhibiting the growth of this pathogen. In this work, the antibiofilm activity of the conA-unbound protein fraction (F1) from M. beecheii was evaluated. The crude protein extract (CPE) and the F1 fraction inhibited the P. aeruginosa biofilm growth above 80% at 4 and 1.3 µg/mL, respectively. These proteins affected the structure of the biofilm, as well as fleQ and fleR gene expressions involved in the formation and regulation of the P. aeruginosa biofilm. The results demonstrated that the F1 fraction proteins of M. beecheii honey inhibit and affect the formation of the P. aeruginosa biofilm.
Assuntos
Mel , Infecções por Pseudomonas , Abelhas , Animais , Pseudomonas aeruginosa/genética , Antibacterianos/farmacologia , Biofilmes , Concanavalina ARESUMO
Research in the treatment of type 1 diabetes has been addressed into two main areas: the development of "intelligent insulins" capable of auto-regulating their own levels according to glucose concentrations, or the exploitation of artificial intelligence (AI) and its learning capacity, to provide decision support systems to improve automated insulin therapy. This review aims to provide a synthetic overview of the current state of these two research areas, providing an outline of the latest development in the search for "intelligent insulins," and the results of new and promising advances in the use of artificial intelligence to regulate automated insulin infusion and glucose control. The future of insulin treatment in type 1 diabetes appears promising with AI, with research nearly reaching the possibility of finally having a "closed-loop" artificial pancreas.
Assuntos
Diabetes Mellitus Tipo 1 , Insulina , Humanos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Inteligência Artificial , Insulina Regular Humana , InteligênciaRESUMO
Posttranslational modifications (PTMs) could influence many aspects of protein behavior and function in organisms. Protein glycosylation is one of the major PTMs observed in bacteria, which is crucial for functional regulations of many prokaryotic and eukaryotic organisms. Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccine has been recognized as an indispensable tool in the global fight against tuberculosis (TB) worldwide over several decades. Nevertheless, analysis of glycoprotein profiles of BCG has not been clearly investigated. In this study, we performed O-mannosylated protein analysis in BCG bacteria using gel-based and gel-free approaches. In total, 1,670 hexosylated peptides derived from 754 mannosylated proteins were identified. Furthermore, 20 novel protein products supported by 78 unique peptides not annotated in the BCG database were detected. Additionally, the translational start sites of 384 proteins were confirmed, and 78 proteins were validated through the extension of translational start sites based on N-terminus-derived peptides. The bioinformatic analysis of the O-mannosylated proteins was performed and the expression profiles of four randomly selected proteins were validated through Western blotting. A number of proteins involved in metabolic pathways, including the tricarboxylic acid cycle, glycolysis, oxidative phosphorylation, and two-component system, are discussed. Taken together, these results offer the first O-mannosylated protein analysis of a member of mycobacteria reported to date by using complementary gel-based and gel-free approaches. Some of the proteins identified in this study have important roles involved in metabolic pathways, which could provide insight into the immune molecular mechanisms of this recognized vaccine strain.
Assuntos
Mycobacterium bovis , Tuberculose , Vacina BCG/metabolismo , Glicosilação , Humanos , Mycobacterium bovis/genética , Mycobacterium bovis/metabolismo , Proteômica/métodosRESUMO
A recent study revealed that d-mannose suppressed immunopathology in mouse models of autoimmune diabetes and airway inflammation and increased the proportion of regulatory T cells (Tregs) in mice. We investigated the effect of d-mannose on liver injury in murine autoimmune hepatitis (AIH) models induced by concanavalin A (ConA) and α-galactosylceramide (GalCer). Mouse models of AIH were created by intraperitoneal injection of GalCer or intravenous injection of ConA. Drinking water was supplemented with d-mannose and biochemically and pathologically examined over time. The administration of d-mannose to AIH model mice significantly reduced liver injury and reduced inflammatory cytokine expression. In addition, Tregs among splenocytes and intrahepatic lymphocytes were significantly increased by the administration of d-mannose. These results indicate that treatment with d-mannose reduced the inflammatory response in the liver and suppressed liver damage by increasing Tregs.
Assuntos
Hepatite Autoimune , Animais , Concanavalina A , Modelos Animais de Doenças , Fígado , Manose/metabolismo , Camundongos , Linfócitos T ReguladoresRESUMO
Concanavalin A (ConA), a mannose (Man)-specific leguminous lectin isolated from the jack bean (Canavalia ensiformis) seed extracts, was discovered over a century ago. Although ConA has been extensively applied in various life science research, recombinant mature ConA expression has not been fully established. Here, we aimed to produce recombinant ConA (rConA) in lettuce (Lactuca sativa) using an Agrobacterium tumefaciens-mediated transient expression system. rConA could be produced as a fully active form from soluble fractions of lettuce leaves and purified by affinity chromatography. From 12 g wet weight of lettuce leaves, 0.9 mg rConA could be purified. The glycan-binding properties of rConA were then compared with that of the native ConA isolated from jack bean using glycoconjugate microarray and frontal affinity chromatography. rConA demonstrated a glycan-binding specificity similar to nConA. Both molecules bound to N-glycans containing a terminal Man residue. Consistent with previous reports, terminal Manα1-6Man was found to be an essential unit for the high-affinity binding of rConA and nConA, while bisecting GlcNAc diminished the binding of rConA and nConA to Manα1-6Man-terminated N-glycans. These results demonstrate that the fully active rConA could be produced using the A. tumefaciens-mediated transient expression system and used as a recombinant substitute for nConA.
Assuntos
Lactuca , Polissacarídeos , Cromatografia de Afinidade , Concanavalina A/metabolismo , Humanos , Lactuca/genética , Lactuca/metabolismo , Folhas de Planta/metabolismo , Polissacarídeos/metabolismoRESUMO
OBJECTIVES: Determine the true incidence and time course of atrial fibrillation (AF) after patent foramen ovale closure (PFOc) using implantable loop recorders (ILR) placed during cryptogenic stroke evaluation. BACKGROUND: Published trials report a 2%-6.6% incidence of postimplant atrial fibrillation (PIAF) after PFOc, which is probably a gross underestimation, as only patients presenting in AF were captured. Episodes of paroxysmal and silent AF would have been missed. METHODS: Of 761 patients who underwent PFOc at a single center between January 2016 and December 2020, 35 patients had an ILR implanted before PFOc, without documentation of AF, and had ≥1 month of monitoring post-PFOc. The incidence, onset, and conclusion of AF episodes were determined from a review of patient records. RESULTS: The mean duration of ILR monitoring was 54.6 ± 39.4 weeks after PFOc. AF occurred in 13/35 (37%) patients. PFOc patients who developed PIAF were older than those who did not (62 ± 11 vs. 52 ± 14 years, p = 0.03). In 12/13, the initial PIAF event occurred within 4 weeks of PFOc, with the greatest frequency around 2 weeks and conclusion by 12 weeks in all. No recurrent strokes occurred during ILR monitoring. CONCLUSION: The actual incidence of PIAF was far greater than previously reported and was significantly associated with older age at PFOc. The timing of PIAF onset and termination were consistent with a postimplant inflammatory mechanism. The higher actual PIAF incidence underscores its low stroke potential in this population. A larger prospective trial is required to validate these preliminary results.
Assuntos
Fibrilação Atrial , Forame Oval Patente , Acidente Vascular Cerebral , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/terapia , Forame Oval Patente/complicações , Forame Oval Patente/diagnóstico por imagem , Forame Oval Patente/epidemiologia , Humanos , Incidência , Estudos Prospectivos , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Resultado do TratamentoRESUMO
OBJECTIVES: To assess the short- and long-term outcomes of balloon pulmonary valvuloplasty (BPV) in children with Noonan syndrome (NS). BACKGROUND: Pulmonary stenosis (PS) is the most common congenital heart lesion in NS. BPV is the accepted first line treatment in PS. However, BPV in NS patients has been reported to be less effective, without specific factors for the need for reintervention being identified. METHODS: Retrospective case-note review of all patients with NS who underwent BPV between 1985 and 2020. Patients were divided into 2 groups: those with supravalvular pulmonary stenosis (SPS) in addition to valvar PS, and those with isolated valvar PS. RESULTS: A cohort of 54 patients with NS underwent BPV at a median of 275 (interquartile range [IQR]: 108-575) days of age. SPS was present in 32 (59%) patients whereas 22 had (41) isolated PS. The preprocedural invasive gradient was 47 (IQR: 35-69) mmHg, and 44 (IQR: 35-48) mmHg in those with SPS and those without respectively (p = 0.88). Reintervention was required in 22 patients (41%): 17 (77%) with SPS and 5 (23%) without (p = 0.017). Fourteen patients (11 with SPS) required surgical reintervention and 8 (6 with SPS) required further BPV. There was no significant difference in the age at initial BPV, pre- and postprocedural gradients and interval until reintervention between groups. CONCLUSION: This is the largest reported cohort of patients with NS undergoing BPV. Although BPV is often successful, the reintervention rates are high. SPS was a risk factor for reintervention.
Assuntos
Síndrome de Noonan , Estenose da Valva Pulmonar , Valva Pulmonar , Criança , Humanos , Síndrome de Noonan/complicações , Síndrome de Noonan/diagnóstico , Valva Pulmonar/diagnóstico por imagem , Valva Pulmonar/cirurgia , Estenose da Valva Pulmonar/diagnóstico por imagem , Estenose da Valva Pulmonar/terapia , Estudos Retrospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
Spermatozoa capacitation is a time-dependent physiological process essential for acquiring the fertilizing capacity. In this context, reorganization of spermatozoa surface sugars and tyrosine phosphorylation are some of the most important biochemical changes involved in capacitation. However, the relationship between these 2 biomarkers remains poorly defined. By cytofluorescence we simultaneously characterized the head concanavalin A (ConA)-binding sites and the flagellar tyrosine phosphorylation before capacitation, during different capacitation times (1 and 4 h), and after acrosome reaction induction in human spermatozoa. The results showed a strong connection between ConA-label patterns and tyrosine phosphorylation according to the spermatozoa capacitation time and acrosomal status. Specifically, the spermatozoa subpopulation with phosphotyrosine presented proper sugar location (label in acrosomal and postacrosomal region) just after 1 h of capacitation, while cells without phosphotyrosine needed 4 h to do it. Moreover, after induction of spermatozoa acrosome reaction, phosphorylation was significantly correlated (p < 0.05) with the relocation of ConA-binding residues to the equatorial region, regardless of capacitation time. Overall, these observations provide novel insights regarding spermatozoa subpopulations based on essential physiological events like capacitation and acrosome reaction, which could have potential implications in the improvement of spermatozoa selection techniques.
Assuntos
Reação Acrossômica , Receptores de Concanavalina A , Sítios de Ligação , Humanos , Masculino , Fosforilação , Receptores de Concanavalina A/metabolismo , Espermatozoides/metabolismo , Tirosina/metabolismoRESUMO
The transient receptor potential melastatin 8 (TRPM8) is an ion channel that has been widely studied as a cold-sensitive nociceptor. However, its importance in nonneuronal cells is mostly unexplored. Here, we describe the presence and functional significance of endogenous TRPM8, a nonselective Ca2+ -channel in T cell functions. The major pool of TRPM8 resides at the T cell surface and its surface accumulation significantly increases in activated T cells. TRPM8 activation synergizes with T-cell receptor (TCR) stimulation to increase CD25, CD69 levels and enhances secretion of proinflammatory cytokine tumor necrosis factor. However, TRPM8 inhibition does not restrict TCR stimulation mediated activation of T cells, indicating that unlike the heat-sensitive TRPV1 and TRPV4 channels, the cold-sensitive TRPM8 channel may be dispensable during T-cell activation, at least in mice. In this study, we demonstrate that TRPM8 promotes TCR-induced intracellular calcium increase. TRPM8 activation is beneficial for T-cell activation and differentiation into effector cells. TRPM8 inhibition during the T-cell activation process may lead to altered phenotype and reduced proliferation, without affecting cell viability. These results collectively establish TRPM8 as a functional calcium channel whose activation may be utilized for mounting an effective immune response. The findings of this study will be relevant to the regulation and response of T cells during cell-mediated immunity. These results will likely further our understanding on the role of ion channels in T-cell activation.
Assuntos
Ativação Linfocitária/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Canais de Cátion TRPM/metabolismo , Animais , Complexo CD3/metabolismo , Cálcio/metabolismo , Membrana Celular/metabolismo , Proliferação de Células , Sobrevivência Celular , Citocinas/metabolismo , Humanos , Células Jurkat , Camundongos , Camundongos Endogâmicos BALB C , Modelos Biológicos , Canais de Cátion TRPM/antagonistas & inibidores , Canais de Cátion TRPV/metabolismoRESUMO
BACKGROUND: Interleukin (IL)-39 is a novel member of IL-12 family and has been reported to play a pro-inflammatory role in lupus-like mice, but its function in concanavalin A (ConA)-induced liver injury is currently unclear. MATERIALS AND METHODS: In this study, we investigated the effects of IL-39 expression in a mouse model of ConA induced-hepatitis. We first showed that delivery of plasmid DNA encoding mouse IL-39 using the hydrodynamic tail vein injection method increased IL-39 mRNA and protein levels in the liver. We then administrated mice with IL-39 plasmid before ConA injection and measured serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, inflammatory infiltration, and hepatocyte necrosis in the liver. Additionally, we further explored the potential mechanism of IL-39 in ConA-induced liver injury by measuring several inflammatory mediators. RESULTS: We found that ectopic IL-39 expression promoted the ConA-induced increase in serum ALT and AST levels, inflammatory infiltration, and hepatocyte necrosis in the liver. We also observed that IL-39 plasmid administration significantly increased serum and liver interferon-γ, tumor necrosis factor-α, and IL-17A levels, but did not affect serum and liver IL-10 levels in ConA-induced hepatitis. CONCLUSION: Our results suggest that IL-39 can exacerbate ConA-induced hepatitis and may be a therapeutic target in inflammatory liver disease.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Concanavalina A/toxicidade , Interleucinas/biossíntese , Fígado/efeitos dos fármacos , Fígado/metabolismo , Animais , Doença Hepática Induzida por Substâncias e Drogas/patologia , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Percutaneous patent foramen ovale (PFO) closure is recommended for secondary prevention of paradoxical embolism through a PFO. In the United States, two Food and Drug Administration-approved PFO closure devices are currently available, and the choice depends on operator preference and PFO anatomy. Although these devices are easy to implant, there are several potential complications. As opposed to the Amplatzer PFO Occluder, there has been no published case of atrial erosion with Gore closure devices. This report describes two cases of pericardial tamponade due to perforation of the atrial wall induced by a wire frame fracture of the Gore Helex and Cardioform devices.
Assuntos
Cateterismo Cardíaco/efeitos adversos , Cateterismo Cardíaco/instrumentação , Tamponamento Cardíaco/etiologia , Forame Oval Patente/terapia , Átrios do Coração/lesões , Traumatismos Cardíacos/etiologia , Falha de Prótese , Dispositivo para Oclusão Septal , Adulto , Tamponamento Cardíaco/diagnóstico por imagem , Tamponamento Cardíaco/cirurgia , Remoção de Dispositivo , Feminino , Forame Oval Patente/complicações , Forame Oval Patente/diagnóstico por imagem , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Traumatismos Cardíacos/diagnóstico por imagem , Traumatismos Cardíacos/cirurgia , Humanos , Pessoa de Meia-Idade , Desenho de Prótese , Resultado do TratamentoRESUMO
Immunoglobulin (Igκ) has been reported to be expressed in sorted liver epithelial cells of µMT mice, and the sequence characteristics of hepatocyte-derived Igκ were different from those of classical B-cell-derived Igκ. However, the physiological function of hepatocyte-derived Igκ is still unclear. The expression of Igκ was firstly identified in primary hepatocytes and normal liver cell line (NCTC1469), and hepatocyte-derived Igκ expression was elevated and displayed unique localization in hepatocytes of concanavalin A (ConA)-induced hepatitis model. Moreover, Igκ knockout mice were more sensitive to ConA-induced hepatitis and had higher serum aspartate aminotransferase (AST) levels, more severe histological injury and a greater number of terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL)-positive cells as compared with littermate controls. Furthermore, knockdown of Igκ in primary hepatocytes and NCTC1469 cells led to accelerated activation of the mitochondrial death pathway and caspase-3 cleavage in vitro, which might be related to inhibition of NF-κB signaling pathway and activation of JNK via the cytoskeleton dynamics. Taken together, these results indicate that hepatocyte-derived Igκ mediates cellular resistance to ConA-induced liver injury by inhibiting activation of caspase-3 and the mitochondrial death pathway, suggesting that Igκ plays an important role in hepatocyte survival and exerts a protective effect against ConA-induced liver injury in mice.
Assuntos
Hepatócitos/metabolismo , Cadeias kappa de Imunoglobulina/metabolismo , Hepatopatias/metabolismo , Animais , Apoptose , Linhagem Celular , Células Cultivadas , Concanavalina A/toxicidade , Citoesqueleto/metabolismo , Hepatócitos/efeitos dos fármacos , Cadeias kappa de Imunoglobulina/genética , Hepatopatias/etiologia , MAP Quinase Quinase 4/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/metabolismo , NF-kappa B/metabolismoRESUMO
BACKGROUND: Liver injury associated with acute graft-versus-host disease (aGVHD) is a frequent and severe complication of hematopoietic stem cell transplantation and remains a major cause of transplant-related mortality. Bone marrow-derived mesenchymal stem cells (BM-MSCs) has been proposed as a potential therapeutic approach for aGVHD. However, the therapeutic effects are not always achieved. In this study, we genetically engineered C57BL/6 mouse BM-MSCs with AKT1 gene and tested whether AKT1-MSCs was superior to control MSCs (Null-MSCs) for cell therapy of liver aGVHD. RESULTS: In vitro apoptosis analyses showed that, under both routine culture condition and high concentration interferon-γ (IFN-γ) (100ng/mL) stimulation condition, AKT1-MSCs had a survival (anti-apoptotic) advantage compared to Null-MSCs. In vivo imaging showed that AKT1-MSCs had better homing capacity and longer persistence in injured liver compared to Null-MSCs. Most importantly, AKT1-MSCs demonstrated an enhanced immunomodulatory function by releasing more immunosuppressive cytokines, such as IL-10. Adoptive transfer of AKT1-MSCs mitigated the histopathological abnormalities of concanavalin A(ConA)-induced liver injury along with significantly lowered serum levels of ALT and AST. The attenuation of liver injury correlated with the decrease of TNF-α and IFN-γ both in liver tissue and in the serum. CONCLUSIONS: In summary, BM-MSCs genetically modified with AKT1 has a survival advantage and an enhanced immunomodulatory function both in vitro and in vivo and thus demonstrates the therapeutic potential for prevention and amelioration of liver GVHD and other immunity-associated liver injuries.
RESUMO
Glycoproteins play a central role in diverse biological processes and are linked with many serious human diseases. In this paper we present a simple, reproducible and cost-effective analytical workflow that enables the reliable quantification of clinically relevant human plasma glycoproteins using label free microflow LC-MS/MS analysis. Plasma N-glycoproteins were selectively extracted via ConA Sepharose lectin affinity chromatography then separated into two fractions using reversed-phase solid phase extraction. LC-MS/MS analysis of the tryptic digest of both fractions identified 90 proteins from which 54 clinically relevant glycoproteins were selected for protein profiling. Careful assessment of the chosen peptides and transitions in terms of reproducibility, selectivity, signal intensity and peak shape was carried out. Measurement of the analytical precision of the method revealed the majority of glycoproteins showed a coefficient of variation (CV) ≤15% (median CV 11.8%, range 3.6-33%). The method was successfully applied to compare glycoproteins in plasma and serum and to detect changes in glycoprotein profile in perturbed plasma pre-treated with ammonium sulphate. Our results show that label-free methodology can be a cost-effective affordable alternative to stable isotope standard workflow when applied for relative protein quantification, especially when targeting a large number of proteins in bioanalytical measurements.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Glicoproteínas/sangue , Espectrometria de Massas em Tandem/métodos , Sulfato de Amônio/química , Cromatografia de Afinidade , Glicoproteínas/isolamento & purificação , Humanos , Análise de Componente Principal , Extração em Fase SólidaRESUMO
Transcatheter valve replacement offers a safe and effective alternative to traditional surgical techniques in patients with congenital heart disease, especially those at high surgical risk. The most common causes of morbidity and mortality in patients with D-transposition of the great arteries status post Senning or Mustard repair is severe tricuspid valve (TV) regurgitation. Replacement of the systemic TV may be useful in those without severe systemic ventricular dysfunction. We present a case of a patient with D-loop transposition of the great arteries status post Mustard repair and TV ring placement with subsequent severe systemic TV regurgitation, at high surgical risk, who underwent a transcatheter valve replacement via a trans-apical approach using an Edwards Sapien XT valve.
Assuntos
Anuloplastia da Valva Cardíaca/instrumentação , Implante de Prótese de Valva Cardíaca/efeitos adversos , Próteses Valvulares Cardíacas , Insuficiência da Valva Tricúspide/cirurgia , Valva Tricúspide/cirurgia , Feminino , Hemodinâmica , Humanos , Pessoa de Meia-Idade , Desenho de Prótese , Recuperação de Função Fisiológica , Índice de Gravidade de Doença , Resultado do Tratamento , Valva Tricúspide/diagnóstico por imagem , Valva Tricúspide/fisiopatologia , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/fisiopatologiaRESUMO
In this experiment,the antioxidant capacity of raspberry extract and the protective effect on liver injury induced by ConA in mice were investigated. Balb/C male mice were randomly divided into six groups: normal group,model group,bicyclol control group( 200 mg·kg~(-1)),low-dose raspberry extract group( 200 mg·kg~(-1)),middle-dose raspberry extract group( 400 mg·kg~(-1)),and highdose raspberry extract group( 800 mg·kg~(-1)). Each group was intragastrically administered with drugs according to the body weight once a day. Seven days later,all of the groups except for the normal group were treated with ConA( 20 mg·kg~(-1)) through tail vein injection to establish the acute liver injury model. The mice were put to death 8 hours later. The organ indexes were calculated. These rum levels of ALT,AST and LDH and the activities of SOD,CAT,GSH and MDA in liver tissue were detected. HE staining was used to observe the pathological changes of liver tissue in mice. Western blot was used to detect the expressions of Bax,Bcl-2,Nrf2 and Keap-1. The antioxidant capacity of raspberry extract was measured by CAA assay. The results showed that,raspberry extract had a strong antioxidant capacity. Simultaneously,compared with the model group,raspberry extract can significantly improve the pathological conditions of liver,and significantly reduce ALT,AST and LDH activities in serum of liver injury mice( P<0. 01). The activities of SOD,CAT in liver homogenate supernatant were significantly increased in the high-dose group,the content of GSH increased,while the content of MDA was sharply declined in the high-dose group( P<0. 01). Meanwhile,raspberry extract down-regulated the expressions of Bax and Keap-1 and up-regulated the expressions of Bcl-2 and Nrf2. CAA showed that the compound raspberry extract had a strong antioxidant capacity. Therefore,raspberry extract has an obvious protective effect on acute liver injury induced by ConA in mice.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Rubus , Animais , Antioxidantes , Fígado , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Substâncias ProtetorasRESUMO
Stromal cells in adipose tissue are useful for repair/regenerative therapy as they harbor a substantial number of mesenchymal stem cells; therefore, freshly isolated autologous uncultured adipose tissue derived stromal cells (u-ADSCs) are useful for regenerative therapy, and obviate the need for mesenchymal stem cells. We evaluated the therapeutic effect of murine u-ADSCs and sorted subsets of u-ADSCs in a concanavalin A (ConA) induced murine model of hepatitis, as well as their characteristics. We found that 10-20% of u-ADSCs expressed the CD45 leukocyte-related antigen. CD68, which is a marker of macrophages (MΦs), was expressed by 50% of CD45+ u-ADSCs. About 90% of CD68+ CD45+ cells expressed CD206 antigen, which is a marker of inhibitory M2-type MΦs. Genes related to M2-type MUs were especially more highly expressed by CD45+ CD206+ u-ADSCs than by CD45- u-ADSCs. CD45+ u-ADSCs inhibited the expression of cytokines/chemokines and suppressed the proliferation of splenocytes stimulated with ConA. We observed that not only whole u-ADSCs, but also the CD45+ subset of u-ADSCs ameliorated the ConA-induced hepatitis in mice. In conclusion, we show that freshly isolated murine u-ADSCs were effective against acute hepatitis, and CD45+ u-ADSCs acting phenotypically and functionally like M2-type MΦs, contributed to the repair of liver tissue undergoing inflammation.
Assuntos
Tecido Adiposo/imunologia , Antígenos Comuns de Leucócito/imunologia , Células-Tronco Mesenquimais/imunologia , Células Estromais/imunologia , Tecido Adiposo/citologia , Tecido Adiposo/metabolismo , Animais , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/imunologia , Doença Hepática Induzida por Substâncias e Drogas/terapia , Concanavalina A/toxicidade , Citometria de Fluxo , Perfilação da Expressão Gênica/métodos , Interleucina-10/imunologia , Interleucina-10/metabolismo , Antígenos Comuns de Leucócito/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/metabolismo , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/metabolismo , Células Estromais/transplanteRESUMO
BACKGROUND/AIMS: Autoimmune hepatitis (AIH) is a chronic necroinflammatory disease of the liver whose pathogenic mechanisms have not yet been elucidated. Moreover, the current treatment used for the vast majority of AIH patients is largely dependent on immunosuppressant administration and liver transplantation. However, research on the pathogenesis of AIH and effective new treatments for AIH have been hampered by a lack of animal models that accurately reproduce the human condition. METHODS: AIH models created by concanavalin A (ConA) injections at different times and doses. The levels of ALT, AST, LDH and inflammatory cytokines were examined at various times after 20 mg/kg ConA was administered by ELISA using commercially available kits. Moreover, liver pathological changes were observed by flow cytometry (FCM) and H&E staining. RESULTS: Our experiments demonstrated that the levels of ALT, AST, LDH and several inflammatory cytokines, including TNF-α, IFN-γ, and IL-6, were higher in the 20 mg/kg 12 h ConA group than in the other groups. Importantly, the numbers of activated CD4+ and CD8+ T lymphocytes in the blood, spleen and liver were calculated. These results showed that ConA (20 mg/kg for 12 h)-induced hepatitis was similar to that in clinical AIH patients. Furthermore, we found that the number of MDSCs in the blood was significantly increased in the ConA (20 mg/kg for 12 h) group compared with controls. Our findings indicated that ConA (20 mg/kg for 12 h)-induced hepatitis could be used as an experimental murine model that mirrors most of the pathogenic properties of human type I AIH. CONCLUSION: This model [ConA (20 mg/kg for 12 h)] provides a valuable tool for studying AIH immunopathogenesis and rapidly assessing novel therapeutic approaches.
Assuntos
Concanavalina A/toxicidade , Hepatite Autoimune/patologia , Adulto , Alanina Transaminase/sangue , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Aspartato Aminotransferases/sangue , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Modelos Animais de Doenças , Feminino , Hepatite Autoimune/etiologia , Hepatite Autoimune/metabolismo , Humanos , Interleucina-4/metabolismo , Interleucina-6/metabolismo , Lectinas Tipo C/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The context of the article: Leishmania amazonensis has a wide geographical distribution throughout South American countries and can cause self-healing to severe cases as mucocutaneous or visceral forms. Leishmaniasis presents a balance of inflammatory and anti-inflammatory cytokines which is responsible for promoting the activation of phagocytes, essential to control the infection and lead to tissue repair/resolution of the disease, respectively. Results and discussion: Our model revealed that the treatment with Con-A was capable to stimulate human PBMC cells by increasing the phagocytic capacity and promoting parasite elimination. The pretreatment with Con-A promoted inflammatory (IFN-γ, TNF-α, IL-2 and IL-6) and anti-inflammatory (IL-4 and IL-10) cytokines production, increased the reactive oxygen species (ROS) sinthesys as well as the expression and presence of iNOS enzyme, but not nitric oxide production. Conclusion: Based on the data obtained, it was possible to infer that Con-A induces the ROS production, responsible for eliminating parasites in addition to regulatory cytokines synthesis which are important for disease resolution.
Assuntos
Antiprotozoários/farmacologia , Concanavalina A/farmacologia , Leishmania/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Animais , Células Cultivadas , Citocinas/biossíntese , Voluntários Saudáveis , Humanos , Imunidade Celular/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/parasitologia , Óxido Nítrico Sintase Tipo II/genética , Fagócitos/efeitos dos fármacos , Fagócitos/imunologia , Fagócitos/metabolismo , Fagócitos/parasitologiaRESUMO
Lectins are a widely studied group of proteins capable of specific and reversible binding to carbohydrates. Undoubtedly, the best characterized are those extracted from plants of the Leguminosae family. Inside this group of proteins, those from the Diocleinae subtribe have attracted attention, in particular Concanavalin A (ConA), the best-studied lectin of the group. Diocleinae lectins, also called ConA-like lectins, present a high similarity of sequence and three-dimensional structure and are known to present inflammatory, vasoactive, antibiotic, immunomodulatory and antitumor activities, among others. This high similarity of lectins inside the ConA-like group makes it possible to use them to study structure/biological activity relationships by the variability of both carbohydrate specificity and biological activities results. It is in this context the following review aims to summarize the most recent data on the biochemical and structural properties, as well as biological activities, of ConA-like lectins and the use of these lectins as models to study structure/biological activity relationships.