RESUMO
Perineuronal nets (PNN) are highly specialized structures of the extracellular matrix around specific groups of neurons in the central nervous system (CNS). They play functions related to optimizing physiological processes and protection neurons against harmful stimuli. Traditionally, their existence was only described in the CNS. However, there was no description of the presence and composition of PNN in the enteric nervous system (ENS) until now. Thus, our aim was to demonstrate the presence and characterize the components of the PNN in the enteric nervous system. Samples of intestinal tissue from mice and humans were analyzed by RT-PCR and immunofluorescence assays. We used a marker (Wisteria floribunda agglutinin) considered as standard for detecting the presence of PNN in the CNS and antibodies for labeling members of the four main PNN-related protein families in the CNS. Our results demonstrated the presence of components of PNN in the ENS of both species; however its molecular composition is species-specific.
Assuntos
Sistema Nervoso Entérico , Matriz Extracelular , Animais , Sistema Nervoso Entérico/metabolismo , Humanos , Camundongos , Masculino , Feminino , Matriz Extracelular/metabolismo , Adulto , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Lectinas de Plantas/metabolismo , Idoso , Especificidade da Espécie , Receptores de N-Acetilglucosamina/metabolismo , Rede Nervosa/metabolismo , Rede Nervosa/química , Neurônios/metabolismoRESUMO
The perineuronal net (PNN) is a well-described highly specialized extracellular matrix structure found in the central nervous system. Thus far, no reports of its presence or connection to pathological processes have been described in the peripheral nervous system. Our study demonstrates the presence of a PNN in the spinal afferent innervation of the distal colon of mice and characterizes structural and morphological alterations induced in an ulcerative colitis (UC) model. C57Bl/6 mice were given 3% dextran sulfate sodium (DSS) to induce acute or chronic UC. L6/S1 dorsal root ganglia (DRG) were collected. PNNs were labeled using fluorescein-conjugated Wisteria Floribunda (WFA) l lectin, and calcitonin gene-related peptide (CGRP) immunofluorescence was used to detect DRG neurons. Most DRG cell bodies and their extensions toward peripheral nerves were found surrounded by the PNN-like structure (WFA+), labeling neurons' cytoplasm and the pericellular surfaces. The amount of WFA+ neuronal cell bodies was increased in both acute and chronic UC, and the PNN-like structure around cell bodies was thicker in UC groups. In conclusion, a PNN-like structure around DRG neuronal cell bodies was described and found modulated by UC, as changes in quantity, morphology, and expression profile of the PNN were detected, suggesting a potential role in sensory neuron peripheral sensitization, possibly modulating the pain profile of ulcerative colitis.
Assuntos
Colite Ulcerativa , Colo , Gânglios Espinais , Camundongos Endogâmicos C57BL , Animais , Colite Ulcerativa/patologia , Colite Ulcerativa/metabolismo , Camundongos , Gânglios Espinais/patologia , Gânglios Espinais/metabolismo , Colo/inervação , Colo/patologia , Colo/metabolismo , Masculino , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Matriz Extracelular/patologia , Matriz Extracelular/metabolismo , Sulfato de Dextrana/toxicidade , Rede Nervosa/patologia , Rede Nervosa/metabolismoRESUMO
AIMS: Inflammatory bowel disease is recurrent inflammation that affects the gastrointestinal tract causing changes in intestinal motility. The evolution of these changes is not completely understood. The aim of this study was to evaluate anatomical and functional changes in the colon during the development of acute and chronic DSS-induced ulcerative colitis (UC) in C57Bl/6 mice. MATERIALS AND METHODS: Mice were relocated into 5 groups: control (GC) and groups exposed to DSS 3 % for 2 (DSS2d), 5 (DSS5d) and 7 DSS7d) days (acute UC) or 3 cycles (DSS3C; Chronic UC). Mice were monitored daily. After euthanasia, colonic tissue was assessed with histological, immunofluorescence and colon manometry methods. KEY FINDINGS: Ulcerative Colitis is a chronic disease characterized by overt inflammation of the colon. Here we investigate whether the morphological changes caused by UC in the colonic wall, in tuft cells and in enteric neurons also promote any alteration in colonic motility patterns. UC Promotes thickening in the colonic wall, fibrosis, reduction in the number of tuft cells and consequently goblet cells also, without promoting neuronal death however there is a change in the chemical code of myenteric neurons. All of these morphological changes were responsible for causing a change in colonic contractions, colonic migration motor complex, total time of gastrointestinal transit and therefore promoting dysmotility. Further studies stimulating a hyperplasia of tuft cells may be the way to try to keep the colonic epithelium healthy, reducing the damage caused by UC. SIGNIFICANCE: Increasing disease pathology of DSS-induced UC induces structural and neuroanatomical changes and driven damage to cholinergic neurons causes colonic dysmotility, including increase of cholinergic myenteric neurons, followed by variations in the motility pattern of different regions of the colon that taking together characterize colonic dysmotility.
Assuntos
Colite Ulcerativa , Colite , Camundongos , Animais , Colite Ulcerativa/patologia , Colite/induzido quimicamente , Colite/patologia , Colo/patologia , Inflamação/patologia , Doença Crônica , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Camundongos Endogâmicos C57BLRESUMO
Chagas disease, caused by the protozoan Trypanosoma cruzi, is one of the main causes of death due to cardiomyopathy and heart failure in Latin American countries. The treatment of Chagas disease is directed at eliminating the parasite, decreasing the probability of cardiomyopathy and disrupting the disease transmission cycle. Benznidazole (BZ) and nifurtimox (Nfx) are recognized as effective drugs for the treatment of Chagas disease by the World Health Organization, but both have high toxicity and limited efficacy, especially in the chronic disease phase. At low doses, aspirin (ASA) has been reported to protect against T. cruzi infection. We evaluated the effectiveness of BZ in combination with ASA at low doses during the acute disease phase and evaluated cardiovascular aspects and cardiac lesions in the chronic phase. ASA treatment prevented the cardiovascular dysfunction (hypertension and tachycardia) and typical cardiac lesions. Moreover, BZ+ASA-treated mice had a smaller cardiac fibrotic area than BZ-treated mice. These results were associated with an increase in numbers of eosinophils and reticulocytes and levels of nitric oxide in the plasma and cardiac tissue of ASA-treated mice relative to respective controls. These effects of ASA and BZ+ASA in chronically infected mice were inhibited by pretreatment with the lipoxin A4 (LXA4) receptor antagonist Boc-2, indicating that the protective effects of ASA are mediated by ASA-triggered lipoxin. These results emphasize the importance of exploring new drug combinations for treatments of the acute phase of Chagas disease that are beneficial for patients with chronic disease.
Assuntos
Doença de Chagas , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Animais , Aspirina/uso terapêutico , Doença de Chagas/tratamento farmacológico , Combinação de Medicamentos , Humanos , Camundongos , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Tripanossomicidas/uso terapêuticoRESUMO
We evaluated the influence of metabolic syndrome (MS) on acute Trypanosoma cruzi infection. Obese Swiss mice, 70 days of age, were subjected to intraperitoneal infection with 5 × 102 trypomastigotes of the Y strain. Cardiovascular, oxidative, inflammatory, and metabolic parameters were evaluated in infected and non-infected mice. We observed higher parasitaemia in the infected obese group (IOG) than in the infected control group (ICG) 13 and 15 days post-infection. All IOG animals died by 19 days post-infection (dpi), whereas 87.5% of the ICG survived to 30 days. Increased plasma nitrite levels in adipose tissue and the aorta were observed in the IOG. Higher INF-γ and MCP-1 concentrations and lower IL-10 concentrations were observed in the IOG compared to those in the ICG. Decreased insulin sensitivity was observed in obese animals, which was accentuated after infection. Higher parasitic loads were found in adipose and hepatic tissue, and increases in oxidative stress in cardiac, hepatic, and adipose tissues were characteristics of the IOG group. Thus, MS exacerbates experimental Chagas disease, resulting in greater damage and decreased survival in infected animals, and might be a warning sign that MS can influence other pathologies.
Assuntos
Tecido Adiposo/metabolismo , Doença de Chagas/metabolismo , Inflamação/metabolismo , Fígado/metabolismo , Síndrome Metabólica/metabolismo , Miocárdio/metabolismo , Estresse Oxidativo/fisiologia , Tecido Adiposo/patologia , Animais , Doença de Chagas/complicações , Doença de Chagas/patologia , Citocinas/sangue , Modelos Animais de Doenças , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Inflamação/complicações , Inflamação/patologia , Resistência à Insulina/fisiologia , Fígado/patologia , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/patologia , Camundongos , Miocárdio/patologia , Trypanosoma cruziRESUMO
Infection of Giardia duodenalis is one of the most common human parasitic disease worldwide. This infection may be related to important changes in the enteric nervous system. The objective of this study was to evaluate the myenteric and submucosal plexuses, the intestinal muscle layer, and gastrointestinal transit in mice infected with assemblages A and B of G. duodenalis. Swiss albino mice (Mus musculus) were infected with assemblages A and B of G. duodenalis for 15 days. Gastrointestinal transit time was evaluated before euthanasia. Duodenum and jejunum were removed for histological and immunohistochemical analyses. It was observed a reduction in the enteric glial cell count and a decrease in the ratio of enteric glial cells to neurons. The number of neurons did not change, but morphological changes were observed in the duodenum and jejunum in both plexuses, including an increase in the nuclear area and a reduction of cell bodies in the myenteric plexus and a decrease in the nuclear area in the submucosal plexus. A reduction of the thickness of the muscle layer was observed in the duodenum, with no significant differences in the gastrointestinal transit times. Assemblages A and B of G. duodenalis decrease the number of enteric glial cells in the myenteric and submucosal plexuses, decrease the thickness of the muscle layer, and change the morphology of neurons. Graphical abstract á .
Assuntos
Duodeno/citologia , Giardia lamblia/patogenicidade , Giardíase/patologia , Jejuno/citologia , Neuroglia/citologia , Neurônios/citologia , Animais , Contagem de Células , Modelos Animais de Doenças , Duodeno/inervação , Duodeno/parasitologia , Trânsito Gastrointestinal/fisiologia , Giardíase/parasitologia , Humanos , Jejuno/inervação , Jejuno/parasitologia , Masculino , Camundongos , Músculos/parasitologia , Músculos/patologia , Plexo Mientérico/citologiaRESUMO
In the enteric nervous system (ENS), nitrergic neurons produce and use nitric oxide (NO) as an inhibitory motor neurotransmitter in response to parasitic infections, including those caused by Toxoplasma gondii. However, damage to the host caused by NO has been reported by various authors, and the role of NO in protection or cytotoxicity continues to be extensively studied. In this study, nitrergic neurons were investigated in the myenteric plexus of the jejunum and the distal colon of rats infected with 500 oocysts of the M7741 strain of T. gondii. Ten rats were randomly assigned into a control group (CG) and infected group (IG; received 500 sporulated oocysts of T. gondii orally). After 24h, the rats were euthanized, and samples of the jejunum and distal colon were obtained and processed for NADPH-diaphorase histochemical analysis. Quantitative and morphometric analysis of the nitrergic neurons in whole mounts containing the myenteric plexus was performed. There was a numeric reduction of nitrergic neurons per mm2 in both jejunum and distal colon. The remaining nitrergic neurons suffered atrophy in the areas of the cell body and nucleus, which resulted in a decrease in cytoplasm. Thus, we conclude that an avirulent strain of T. gondii in a short time causes neuroplastic changes in the small and large intestine of rats.
Assuntos
Neurônios Nitrérgicos/parasitologia , Toxoplasma/patogenicidade , Toxoplasmose/patologia , Animais , Intestinos/inervação , Intestinos/parasitologia , Plexo Mientérico/parasitologia , Plexo Mientérico/patologia , Neurônios Nitrérgicos/patologia , Distribuição Aleatória , Ratos , Ratos Wistar , Toxoplasma/fisiologia , VirulênciaRESUMO
Patients with Chagas' disease may develop dysfunctions of oesophageal and colonic motility resulting from the degeneration or loss of the myenteric neurons of the enteric nervous system. Studies have shown that the use of aspirin, also known as acetylsalicylic acid (ASA), influences the pathogenesis of the disease. However, this remains controversial. The aim of this study was to evaluate the consequences of treatment with low doses of aspirin during the chronic phase of Chagas' disease on oesophageal function. Twenty male Swiss mice, 60 days of age, were used. The animals were infected with Y strain of Trypanosoma cruzi, injected intraperitoneally. Aspirin was given at a dose of 50 mg/kg to some of the infected animals, from the 55th to 63rd day after inoculation on consecutive days, and from the 65th to 75th day on alternate days. We investigated food passage of time, wall structure and nitrergic neuronal population of the distal oesophagus. Our data revealed that the use of low doses of aspirin in chronic Chagas' disease caused an increase in the number of nitrergic neurons and partially prevented hypertrophy of the oesophagus. In addition, the aspirin administration impeded Chagas' diseases associated changes in intestinal transit time. Thus treatment with aspirin in the chronic phase of Chagas' disease changes the natural history of the disease and raises the possibility of using it as a new therapeutic approach to the treatment of this aspect of Chagas' disease pathology.
Assuntos
Aspirina/farmacologia , Doença de Chagas/tratamento farmacológico , Esôfago/patologia , Neurônios/efeitos dos fármacos , Animais , Aspirina/administração & dosagem , Doença de Chagas/patologia , Doença Crônica , Colo/patologia , Modelos Animais de Doenças , Esôfago/efeitos dos fármacos , Masculino , Camundongos , Plexo Mientérico/efeitos dos fármacos , Plexo Mientérico/patologia , Neurônios/patologiaRESUMO
Oral transmission of the protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas disease, has been documented in Latin American countries. The reported cases of infection were due to the ingestion of contaminated fresh fruit, juices, or sugar cane juice. There have been few studies on the physiopathology of the disease in oral transmission cases. Gastritis is a common ailment that can be caused by poor dietary habits, intake of alcohol or other gastric irritants, bacterial infection, or by the widespread use of non-steroidal anti-inflammatory drugs (NSAIDs). This study investigated in a mouse model whether gastric mucosal injury, induced by aspirin, would affect the course of disease in animals infected with T. cruzi by the oral route. The CL14 and G strains of T. cruzi, both of low infectivity, were used. To this end, groups of BALB/c mice were treated during 5 days with aspirin (100 mg kg(-1)) before oral infection with T. cruzi metacyclic forms (4 × 10(5) or 5 × 10(7) parasites/mouse). Histological analysis and determination of nitric oxide and TNF-α were performed in gastric samples obtained 5 days after infection. Parasitemia was monitored from the thirteenth day after infection. The results indicate that aspirin treatment of mice injured their gastric mucosa and facilitated invasion by both CL14 and G strains of T. cruzi. Strain CL14 caused more severe infection compared to the G strain, as larger numbers of amastigote nests were found in the stomach and parasitemia levels were higher. Our study is novel in that it shows that gastric mucosal damage caused by aspirin, a commonly used NSAID, facilitates T. cruzi infection by the oral route.
Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Aspirina/efeitos adversos , Doença de Chagas/etiologia , Mucosa Gástrica/efeitos dos fármacos , Gastrite/complicações , Animais , Bebidas/parasitologia , Doença de Chagas/transmissão , Carboidratos da Dieta , Feminino , Parasitologia de Alimentos , Frutas/parasitologia , Mucosa Gástrica/química , Mucosa Gástrica/patologia , Gastrite/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nitritos/metabolismo , Estômago/parasitologia , Trypanosoma cruzi/efeitos dos fármacos , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Chronic mucocutaneous candidiasis constitutes a heterogeneous group of syndromes, characterized by non-invasive infection of the skin, nails and mucosal membranes by the fungus Candida spp. Although symptoms are heterogeneous, in all cases there is a reduction in protective cytokines, favouring the development of disease. The normal role of cytokines in skin lesions is not well understood. The present study aimed to investigate the progression of disease, understand specific cellular and molecular components involved in immunity to Candida albicans and determine the balance between pro- and anti-inflammatory cytokines over the course of cutaneous infection in immunocompetent mice. BALB/c mice (five per group) were inoculated with 5 × 10(6)C. albicans pseudohyphae in the deep dermis of the paw and analysed over 1-14â days post-infection. The contralateral paws were used for negative controls. Haematoxylin and eosin staining of skin sections during C. albicans infection was performed to analyse structural modifications to the epidermis such as hyperplasia, and infiltration of neutrophils and fibroblasts in the dermis. The cytokine populations were determined by capture ELISA using popliteal lymph node tissue. Pro-inflammatory cytokines (IL-6, TNF-α, IL-12, IFN-γ and IL-17) were detected at significant levels during the initial phase of cutaneous infection and correlated with the rapid elimination of C. albicans. Anti-inflammatory cytokines (IL-13, IL-4, IL-10 and transforming growth factor-ß) were detected on day 4 post-infection, and prevented exacerbation of inflammation and participated in healing of lesions. Thus, a balance between pro- and anti-inflammatory cytokines was fundamental for the resolution of infection. Importantly, these findings broaden our understanding of the immune mechanisms involved in chronic cutaneous candidiasis.
Assuntos
Candida albicans/crescimento & desenvolvimento , Candida albicans/imunologia , Candidíase Cutânea/imunologia , Candidíase Cutânea/patologia , Pele/imunologia , Pele/patologia , Animais , Citocinas/análise , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Histocitoquímica , Linfonodos/imunologia , Camundongos Endogâmicos BALB C , Microscopia , Neutrófilos/imunologiaRESUMO
Toxoplasmosis is a widely distributed disease caused by the protozoan Toxoplasma gondii that is mainly transmitted orally. Once ingested, the parasite crosses the intestinal barrier to reach the blood and lymph systems to migrate to other regions of the host. The objective of this study was to evaluate the changes in the myenteric plexus and the jejunal wall of Wistar rats caused by oral infection with T. gondii oocysts (ME-49 strain). Inocula of 10, 100, 500 and 5000 oocysts were used. The total population of myenteric neurons and the most metabolically active subpopulation (NADH-diaphorase positive - NADH-dp) exhibited a decrease proportional to the dose of T. gondii. There was also a quantitative increase in the subpopulation of NADPH-diaphorase-positive (NADPH-dp) myenteric neurons, indicating greater expression of the NOS enzyme. Neuronal atrophy was observed, and morphological and morphometric alterations such as jejunal atrophy were found in the infected groups. Hypertrophy of the external muscle with the presence of inflammatory foci was observed in the group infected with 5000 oocysts. The changes observed in the infected groups were proportional to the number of oocysts inoculated.
Assuntos
Jejuno/patologia , Plexo Mientérico/patologia , Toxoplasmose Animal/patologia , Animais , Anticorpos Antiprotozoários/sangue , Modelos Animais de Doenças , Histocitoquímica , Imunoglobulina G/sangue , Masculino , NAD , NADP , Neurônios/patologia , Distribuição Aleatória , Ratos , Ratos Wistar , Toxoplasma/imunologiaRESUMO
During the aging process, the body's systems change structurally and loss of function can occur. Ingesting a smaller amount of food has been considered a plausible proposal for increased longevity with the quality of life. However, the effects of dietary restriction (DR) during aging are still poorly understood, especially for organs of the digestive system. This study aimed to describe the body weight, oxidative status and possible morphological changes of the intestinal wall of rats submitted to DR during the aging process (7 to 18months old). Twelve 7-month-old male Wistar rats fed ad libitum since birth were assigned to two groups: control group (CG, n=6) fed ad libitum from 7 to 18months old; and dietary restriction group (DRG, n=6) fed 50% of the amount of chow consumed by the CG from 7 to 18months old. The body weight, feed and water intake were monitored throughout the experiment. Blood, periepididymal adipose tissue (PAT) and retroperitoneal adipose tissue (RAT), and the small intestine were collected at 18months old. The blood was collected to evaluate its components and oxidative status. Sections from the duodenum and ileum were stained with HE, PAS and AB pH2.5 for morphometric analyses of the intestinal wall components, and to count intraepithelial lymphocytes (IELs), goblet cells and cells in mitosis in the epithelium. DR rats showed a reduction in weight, naso-anal length, PAT, RAT and intestinal length; however, they consumed more water. Blood parameters indicate that the DR rats remained well nourished. In addition, they showed lower lipid peroxidation. Hypertrophy of the duodenal mucosa and atrophy of the ileal mucosa were observed. The number of goblet cells and IELs was reduced, but the mitotic index remained unaltered in both duodenum and ileum. In conclusion, 50% dietary restriction for rats from 7 to 18months old contributed to improving their nutritional parameters but, to achieve this, adjustments were required in the structure of the body weight and morphology of the small intestine.