RESUMEN
During neuronal pruning, phagocytes engulf shed cellular debris to avoid inflammation and maintain tissue homeostasis. How phagocytic receptors recognize degenerating neurites had been unclear. Here, we identify two glucosyltransferases Alg8 and Alg10 of the N-glycosylation pathway required for dendrite fragmentation and clearance through genetic screen. The scavenger receptor Draper (Drpr) is N-glycosylated with complex- or hybrid-type N-glycans that interact specifically with galectins. We also identify the galectins Crouching tiger (Ctg) and Hidden dragon (Hdg) that interact with N-glycosylated Drpr and function in dendrite pruning via the Drpr pathway. Ctg and Hdg are required in hemocytes for expression and function, and are induced during dendrite injury to localize to injured dendrites through specific interaction with exposed phosphatidylserine (PS) on the surface membrane of injured dendrites. Thus, the galectins Ctg and Hdg bridge the interaction between PS and N-glycosylated Drpr, leading to the activation of phagocytosis.
Asunto(s)
Dendritas , Galectinas , Hemocitos , Fagocitosis , Fosfatidilserinas , Animales , Fosfatidilserinas/metabolismo , Glicosilación , Galectinas/metabolismo , Hemocitos/metabolismo , Dendritas/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genéticaRESUMEN
An outbreak of SARS-CoV-2 coronavirus (COVID-19) first detected in Wuhan, China, has created a public health emergency all over the world. The pandemic has caused more than 340 million confirmed cases and 5.57 million deaths as of 23 January 2022. Although carbohydrates have been found to play a role in coronavirus binding and infection, the role of cell surface glycans in SARS-CoV-2 infection and pathogenesis is still not understood. Herein, we report that the SARS-CoV-2 spike protein S1 subunit binds specifically to blood group A and B antigens, and that the spike protein S2 subunit has a binding preference for Lea antigens. Further examination of the binding preference for different types of red blood cells (RBCs) indicated that the spike protein S1 subunit preferentially binds with blood group A RBCs, whereas the spike protein S2 subunit prefers to interact with blood group Lea RBCs. Angiotensin converting enzyme 2 (ACE2), a known target of SARS-CoV-2 spike proteins, was identified to be a blood group A antigen-containing glycoprotein. Additionally, 6-sulfo N-acetyllactosamine was found to inhibit the binding of the spike protein S1 subunit with blood group A RBCs and reduce the interaction between the spike protein S1 subunit and ACE2.
Asunto(s)
Carbohidratos/química , SARS-CoV-2/química , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/metabolismo , COVID-19/virología , Carbohidratos/genética , China , Eritrocitos/metabolismo , Humanos , Ligandos , Polisacáridos , Análisis por Matrices de Proteínas , Unión Proteica , SARS-CoV-2/metabolismo , Internalización del VirusRESUMEN
Fatty liver diseases, common metabolic diseases in chickens, can lead to a decrease in egg production and sudden death of chickens. To solve problems caused by the diseases, reliable chicken models of fatty liver disease are required. To generate chicken models of fatty liver, 7-week-old ISA female chickens were fed with a control diet (17% protein, 5.3% fat, and 1,300 mg/kg choline), a low protein and high fat diet (LPHF, 13% protein, 9.1% fat, and 1,300 mg/kg choline), a high cholesterol with low choline diet (CLC, 17% protein, 7.6% fat with additional 2% cholesterol, and 800 mg/kg choline), a low protein, high fat, high cholesterol, and low choline diet (LPHFCLC, 13% protein, 12.6% fat with additional 2% cholesterol, and 800 mg/kg choline) for 4 wk. Our data showed that the CLC and LPHFCLC diets induced hyperlipidemia. Histological examination and the content of hepatic lipids indicated that the CLC and LPHFCLC diets induced hepatic steatosis. Plasma dipeptidyl peptidase 4, a biomarker of fatty liver diseases in laying hens, increased in chickens fed with the CLC or LPHFCLC diets. Hepatic ballooning and immune infiltration were observed in these livers accompanied by elevated interleukin 1 beta and lipopolysaccharide induced tumor necrosis factor mRNAs suggesting that the CLC and LPHFCLC diets also caused steatohepatitis in these livers. These diets also induced hepatic steatosis in Plymouth Rock chickens. Thus, the CLC and LPHFCLC diets can be used to generate models for fatty liver diseases in different strains of chickens. In ISA chickens fed with the CLC diet, peroxisome proliferator-activated receptor γ, sterol regulatory element binding transcription factor 1, and fatty acid synthase mRNAs increased in the livers, suggesting that lipogenesis was enhanced by the CLC treatment. Our data show that treatment with CLC or LPHFCLC for 4 wk induces fatty liver disease in chickens. These diets can be utilized to rapidly generate chicken models for fatty liver research.
Asunto(s)
Pollos , Colesterol , Colina , Dieta , Hígado Graso , Hiperlipidemias , Animales , Colesterol/metabolismo , Colina/metabolismo , Dieta/veterinaria , Modelos Animales de Enfermedad , Hígado Graso/fisiopatología , Hígado Graso/veterinaria , Femenino , Hiperlipidemias/veterinaria , Hígado/patología , Enfermedades de las Aves de Corral/fisiopatologíaRESUMEN
Adult humans and mice possess significant classical brown adipose tissues (BAT) and, upon cold-induction, acquire brown-like adipocytes in certain depots of white adipose tissues (WAT), known as beige adipose tissues or WAT browning/beiging. Activating thermogenic classical BAT or WAT beiging to generate heat limits diet-induced obesity or type-2 diabetes in mice. Adiponectin is a beneficial adipokine resisting diabetes, and causing "healthy obese" by increasing WAT expansion to limit lipotoxicity in other metabolic tissues during high-fat feeding. However, the role of its receptors, especially adiponectin receptor 1 (AdipoR1), on cold-induced thermogenesis in vivo in BAT and in WAT beiging is still elusive. Here, we established a cold-induction procedure in transgenic mice over-expressing AdipoR1 and applied a live 3-D [18F] fluorodeoxyglucose-PET/CT (18F-FDG PET/CT) scanning to measure BAT activity by determining glucose uptake in cold-acclimated transgenic mice. Results showed that cold-acclimated mice over-expressing AdipoR1 had diminished cold-induced glucose uptake, enlarged adipocyte size in BAT and in browned WAT, and reduced surface BAT/body temperature in vivo. Furthermore, decreased gene expression, related to thermogenic Ucp1, BAT-specific markers, BAT-enriched mitochondrial markers, lipolysis and fatty acid oxidation, and increased expression of whitening genes in BAT or in browned subcutaneous inguinal WAT of AdipoR1 mice are congruent with results of PET/CT scanning and surface body temperature in vivo. Moreover, differentiated brown-like beige adipocytes isolated from pre-adipocytes in subcutaneous WAT of transgenic AdipoR1 mice also had similar effects of lowered expression of thermogenic Ucp1, BAT selective markers, and BAT mitochondrial markers. Therefore, this study combines in vitro and in vivo results with live 3-D scanning and reveals one of the many facets of the adiponectin receptors in regulating energy homeostasis, especially in the involvement of cold-induced thermogenesis.
Asunto(s)
Tejido Adiposo Beige/metabolismo , Tejido Adiposo Pardo/metabolismo , Receptores de Adiponectina/genética , Termogénesis/genética , Proteína Desacopladora 1/genética , Adipocitos Beige/metabolismo , Tejido Adiposo Beige/diagnóstico por imagen , Tejido Adiposo Pardo/diagnóstico por imagen , Tejido Adiposo Blanco/diagnóstico por imagen , Tejido Adiposo Blanco/metabolismo , Animales , Metabolismo Energético/genética , Regulación del Desarrollo de la Expresión Génica/genética , Ratones , Ratones Transgénicos/genética , Ratones Transgénicos/metabolismo , Mitocondrias/genética , Obesidad/genética , Obesidad/metabolismo , Obesidad/patología , Tomografía de Emisión de PositronesRESUMEN
Leucine-rich repeat kinase 2 (LRRK2) is involved in lipid metabolism; however, the role of LRRK2 in lipid metabolism to affect non-alcoholic fatty liver disease (NAFLD) is still unclear. In the mouse model of NAFLD induced by a high-fat diet, we observed that LRRK2 was decreased in livers. In HepG2 cells, exposure to palmitic acid (PA) down-regulated LRRK2. Overexpression and knockdown of LRRK2 in HepG2 cells were performed to further investigate the roles of LRRK2 in lipid metabolism. Our results showed that ß-oxidation in HepG2 cells was promoted by LRRK2 overexpression, whereas LRRK2 knockdown inhibited ß-oxidation. The critical enzyme of ß-oxidation, carnitine palmitoyltransferase 1A (CPT1A), was positively regulated by LRRK2. Our data suggested that the regulation of CPT1A by LRRK2 may be via the activation of AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor α (PPARα). The overexpression of LRRK2 reduced the concentration of a pro-inflammatory cytokine, tumor necrosis factor α (TNFα), induced by PA. The increase in ß-oxidation may promote lipid catabolism to suppress inflammation induced by PA. These results indicated that LRRK2 participated in the regulation of ß-oxidation and suggested that the decreased LRRK2 may promote inflammation by suppressing ß-oxidation in the liver.
Asunto(s)
Carnitina O-Palmitoiltransferasa/fisiología , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/fisiología , Oxígeno/metabolismo , Animales , Núcleo Celular/metabolismo , Citocinas/metabolismo , Dieta Alta en Grasa , Células Hep G2 , Humanos , Inflamación , Metabolismo de los Lípidos , Masculino , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Oxidación-Reducción , PPAR alfa/metabolismo , Ácido Palmítico/farmacología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Mass spectrometry imaging (MSI) using the ambient ionization technique enables a direct chemical investigation of biological samples with minimal sample pretreatment. However, detailed morphological information of the sample is often lost due to its limited spatial resolution. In this study, predictive high-resolution molecular imaging was produced by the fusion of ambient ionization MSI with optical microscopy of routine hematoxylin and eosin (H&E) staining. Specifically, desorption electrospray ionization (DESI) and nanospray desorption electrospray ionization (nanoDESI) mass spectrometry were employed to visualize lipid and protein species on mice tissue sections. The resulting molecular distributions obtained by ambient ionization MSI-microscopy fusion were verified with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MSI and immunohistochemistry (IHC) staining. Label-free molecular imaging with 5-µm spatial resolution can be acquired using DESI and nanoDESI, whereas the typical spatial resolution of ambient ionization MSI was â¼100⯵m. In this regard, sharpened molecular histology of tissue sections was achieved, providing complementary references to the pathology. Such a multi-modal integration enables the discovery of potential tumor biomarkers. After image fusion, more than a dozen potential biomarkers on a metastatic mouse lung tissue section and Luminal B breast tumor tissue section were identified.
Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias de la Mama/diagnóstico por imagen , Lípidos/análisis , Neoplasias Pulmonares/diagnóstico por imagen , Proteínas de Neoplasias/análisis , Imagen Óptica , Animales , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/secundario , Ratones , Ratones Endogámicos ICR , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
BACKGROUND: Adiponectin (ADN) is an adipokine derived from adipocytes. It binds to adiponectin receptor 1 and 2 (AdipoR1 and R2) to exert its function in regulating whole-body energy homeostasis and inflammatory responses. However, the role of ADN-AdipoR1 signaling in intestinal inflammation is controversial, and its role in the regulation of neutrophils is still unclear. Our goal was to clarify the role of AdipoR1 signaling in colitis and the effects on neutrophils. METHODS: We generated porcine AdipoR1 transgenic mice (pAdipoR1 mice) and induced murine colitis using dextran sulfate sodium (DSS) to study the potential role of AdipoR1 in inflammatory bowel disease. We also treated a THP-1 macrophage and a HT-29 colon epithelial cell line with ADN recombinant protein to study the effects of ADN on inflammation. RESULTS: After inducing murine colitis, pAdipoR1 mice developed more severe symptoms than wild-type (WT) mice. Treatment with ADN increased the expression of pro-inflammatory factors in THP-1 and HT-29 cells. Moreover, we also observed that the expression of cyclooxygenase2 (cox2), neutrophil chemokines (CXCL1, CXCL2 and CXCL5), and the infiltration of neutrophils were increased in the colon of pAdipoR1 mice. CONCLUSIONS: Our study showed that ADN-AdipoR1 signaling exacerbated colonic inflammation through two possible mechanisms. First, ADN-AdipoR1 signaling increased pro-inflammatory factors. Second, AdipoR1 enhanced neutrophil chemokine expression and recruited neutrophils into the colonic tissue to increase inflammation.
Asunto(s)
Adiponectina/genética , Colitis/genética , Expresión Génica , Enfermedades Inflamatorias del Intestino/genética , Receptores de Adiponectina/genética , Transducción de Señal , Adiponectina/metabolismo , Animales , Sulfato de Dextran/farmacología , Femenino , Células HT29 , Humanos , Ratones Transgénicos , Receptores de Adiponectina/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sus scrofa , Células THP-1RESUMEN
High expression of either ß4 integrin or focal adhesion kinase (FAK) has been reported in human colon cancer. However, it remains unclear how ß4 integrin together with FAK contributes to the tumorigenicity of colon cancer. Here, we demonstrate that the co-overexpression of ß4 integrin and FAK positively correlates with advanced stages of human colon cancer. Activated ß4 integrin interacts with FAK and subsequently induces FAK phosphorylation at Tyr397. Furthermore, ablation of the ß4 integrin/FAK complex and/or FAK activation impair colon cancer cell proliferation, anchorage-independent growth, and tumorigenicity. Our data indicate that the ß4 integrin/FAK complex and subsequent FAK activation are essential regulators during the tumorigenicity of colon cancer, and we suggest an alternative strategy for colon cancer therapy.
Asunto(s)
Neoplasias del Colon/metabolismo , Quinasa 1 de Adhesión Focal/metabolismo , Integrina beta4/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Femenino , Quinasa 1 de Adhesión Focal/genética , Humanos , Integrina beta4/genética , Masculino , Proteínas de Neoplasias/genética , Fosforilación/genéticaRESUMEN
Although accelerated atherosclerosis and arteriosclerosis are the main causes of cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients, the molecular pathogenesis remains largely obscure. Our study of the aortic function in a typical CKD model of subtotal nephrectomy (SNX) rats demonstrated phenotypes that resemble CKD patients with aortic stiffness. The 2-DE analysis of rat aortas followed by MS identified 29 up-regulated and 53 down-regulated proteins in SNX rats. Further Western blot and immunohistochemistry analyses validated the decreased HSP27 and increased milk fat globule epidermal growth factor-8 (MFG-E8) in SNX rats. Functional classification of differential protein profiles using KOGnitor revealed that the two major categories involved in aortic stiffness are posttranslational modification, protein turnover, chaperones (23%) and cytoskeleton (21%). Ingenuity Pathway Analysis highlighted cellular assembly and organization, and cardiovascular system development and function as the two most relevant pathways. Among the identified proteins, the clinical significance of the secreted protein MFG-E8 was confirmed in 50 CKD patients, showing that increased serum MFG-E8 level is positively related to aortic stiffness and renal function impairment. Drug interventions with an inhibitor of the angiotensin converting enzyme, enalapril, in SNX rats improved aortic stiffness and decreased MFG-E8 depositions. Together, our studies provide a repertoire of potential biomarkers related to the aortic stiffness in CKD.
Asunto(s)
Aorta/química , Nefrectomía , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Antígenos de Superficie , Aorta/efectos de los fármacos , Modelos Animales de Enfermedad , Enalapril/farmacología , Proteínas de Choque Térmico HSP27/análisis , Humanos , Enfermedades Renales/patología , Enfermedades Renales/fisiopatología , Masculino , Proteínas de la Leche/análisis , Proteómica , Ratas , Ratas Sprague-DawleyRESUMEN
Blastocystis hominis is probably the most common protozoan found in the human gut worldwide. In Taiwan, the prevalence of B. hominis infection is yet to be determined but is expected to be relatively higher among foreign workers. No data is available on the prevalence of B. hominis infection in long-term care facilities in Taiwan. This study included 713 subjects (552 residents and 161 care workers) from ten long-term care facilities in Taiwan who completed stool microscopic examinations with Merthiolate-iodine-formalin stain technique. The prevalence rate of blastocystosis was the highest among foreign and domestic care workers followed by residents (12.2%, 4.6%, and 2.7%, respectively). Older age (p = 0.04) and lower educational level (p = 0.008) were significantly associated with blastocystosis among care workers. Among residents, B. hominis infection was negatively associated with prolonged use of antibiotics within 3 months prior to examination (p = 0.05) and positively associated with tracheostomy in-place (p = 0.028). In conclusion, B. hominis infection was the most prevalent intestinal parasitic infection among both care workers and residents of long-term care facilities in Taiwan. Use of antibiotics was negatively associated with B. hominis infection among residents. Additionally, appropriate preventive measures should be implemented to older care workers with lesser educational attainment in order to reduce the risk of blastocystosis infection.