RESUMO
A more complete and holistic view on host-microbe interactions is needed to understand the physiological and cellular barriers that affect the efficacy of drug treatments and allow the discovery and development of new therapeutics. Here, we developed a multimodal imaging approach combining histopathology with mass spectrometry imaging (MSI) and same section imaging mass cytometry (IMC) to study the effects of Salmonella Typhimurium infection in the liver of a mouse model using the S. Typhimurium strains SL3261 and SL1344. This approach enables correlation of tissue morphology and specific cell phenotypes with molecular images of tissue metabolism. IMC revealed a marked increase in immune cell markers and localization in immune aggregates in infected tissues. A correlative computational method (network analysis) was deployed to find metabolic features associated with infection and revealed metabolic clusters of acetyl carnitines, as well as phosphatidylcholine and phosphatidylethanolamine plasmalogen species, which could be associated with pro-inflammatory immune cell types. By developing an IMC marker for the detection of Salmonella LPS, we were further able to identify and characterize those cell types which contained S. Typhimurium.
Assuntos
Espectrometria de Massas/métodos , Imagem Molecular/métodos , Infecções por Salmonella/diagnóstico por imagem , Infecções por Salmonella/microbiologia , Salmonella typhimurium/química , Animais , Feminino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND AND METHODS: In advanced liver damage, hepatic regeneration can occur through proliferation of a resident hepatic progenitor cell (HPC) population. HPCs are located within a designated niche in close association with myofibroblasts and bone marrow (BM) derived macrophages. Extra-cellular matrix (ECM) laminin invariably surrounds HPCs, but the functional requirement of this matrix-cell association is untested in vivo. Using the collagen Iα1((r/r)) mouse (r/r), which produces mutated collagen I resistant to matrix metalloproteinase degradation and has an exaggerated fibrotic response to liver injury, we test the relationship between collagen degradation, laminin deposition, and the HPC response. RESULTS: Chronic fibrotic carbon tetrachloride (CCl4) injury can induce a florid HPC response associated with dense laminin deposition. In the recovery phase after chronic CCl4 injury, r/r mice have a markedly attenuated HPC response compared to wild-types, together with persistence of collagen I and failure to deposit ECM laminin. Similar results were found in r/r mice given the choline-deficient ethionine supplemented diet, another model of the HPC response. In cross-over sex-mismatched BM transplantation (BMT) experiments between r/r mice and wild-types, the blunted HPC response of r/r mice was not rescued by wild-type BMT and likewise not conferred on to wild-type recipients by r/r BMT, demonstrating that the attenuated HPC response in r/r mice is a property intrinsic to the liver. CONCLUSION: Failure of ECM remodelling after chronic fibrotic liver injury hinders the ability of the liver to activate HPCs. Laminin-progenitor cell interactions within the HPC niche are a critical for HPC mediated regeneration.
Assuntos
Matriz Extracelular/fisiologia , Cirrose Hepática Experimental/patologia , Regeneração Hepática/fisiologia , Células-Tronco/patologia , Animais , Células da Medula Óssea/patologia , Transplante de Medula Óssea , Tetracloreto de Carbono , Deficiência de Colina/complicações , Colágeno/metabolismo , Etionina/administração & dosagem , Feminino , Laminina/deficiência , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/fisiopatologia , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
AIM: To assess the effectiveness of the current UK clinical practice in reducing hepatic fat (IHCL). METHODS: Whole body MRI and (1)H MRS were obtained, before and after 6 mo nutritional counselling, from liver, soleus and tibialis muscles in 10 subjects with non-alcoholic fatty liver disease (NAFLD). RESULTS: A 500 Kcal-restricted diet resulted in an average weight loss of 4% (-3.4 kg,) accompanied by significant reductions in most adipose tissue (AT) depots, including subcutaneous (-9.9%), abdominal subcutaneous (-10.2%) and intra-abdominal-AT (-11.4%). Intramyocellular lipids (IMCL) were significantly reduced in the tibialis muscle (-28.2%). Decreases in both IHCL (-39.9%) and soleus IMCL (-12.2%) content were also observed, although these were not significant. Several individuals showed dramatic decreases in IHCL, while others paradoxically showed increases in IHCL content. Changes in body composition were accompanied by improvements in certain liver function tests: serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Significant correlations were found between decreases in IHCL and reductions in both intra-abdominal and abdominal subcutaneous AT. Improvements in liver function tests were associated with reductions in intra-abdominal AT, but not with changes in IHCL. CONCLUSION: This study shows that even a very modest reduction in body weight achieved through lifestyle modification can result in changes in body fat depots and improvements in LFTs.
Assuntos
Tecido Adiposo Branco/metabolismo , Aconselhamento/métodos , Fígado Gorduroso/metabolismo , Metabolismo dos Lipídeos/fisiologia , Fígado/metabolismo , Músculo Esquelético/metabolismo , Terapia Nutricional/métodos , Tecido Adiposo Branco/química , Tecido Adiposo Branco/fisiopatologia , Composição Corporal/fisiologia , Peso Corporal/fisiologia , Fígado Gorduroso/fisiopatologia , Humanos , Estilo de Vida , Fígado/química , Fígado/fisiopatologia , Músculo Esquelético/química , Músculo Esquelético/fisiopatologia , Guias de Prática Clínica como Assunto , Reino Unido , Redução de Peso/fisiologiaRESUMO
Liver biopsy remains the gold standard for characterizing diffuse liver disease and is associated with significant morbidity and, rarely, mortality. Our aim was to investigate whether a noninvasive technique, in vivo phosphorus 31 ((31)P)-magnetic resonance spectroscopy (MRS), could be used to assess the severity of hepatitis C virus (HCV)-related liver disease. Fifteen healthy controls and 48 patients with biopsy-proven HCV-related liver disease were studied prospectively. Based on their histologic fibrosis (F) and necroinflammatory (NI) scores, patients were divided into mild hepatitis (F