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1.
Cardiol Res ; 15(2): 90-98, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38645824

RESUMEN

Background: Sex and racial disparities in the presentation and management of chest pain persist, however, the impact of coronavirus disease 2019 (COVID-19) on these disparities have not been studied. We sought to determine whether the COVID-19 pandemic contributed to pre-existing sex and racial disparities in the presentation, management, and outcomes of patients presenting to the emergency department (ED) with chest pain. Methods: We conducted an observational cohort study with retrospective data collection of patients between January 1, 2016, and May 1, 2022. This was a single study conducted at a quaternary academic medical center of all patients who presented to the ED with a complaint of chest pain or chest pain equivalent symptoms. Patient were further segregated into different groups based on sex (male, female), race, ethnicity (Asian, Black, Hispanic, White, and other), and age (18 - 40, 41 - 65, > 65). We compared diagnostic evaluations, treatment decisions, and outcomes during prespecified time points before, during, and after the COVID-19 pandemic. Results: This study included 95,764 chest pain encounters. Total chest pain presentations to the ED fell about 38% during the early pandemic months. Females presented significantly less than males during initial COVID-19 (48% vs. 52%, P < 0.001) and Asian females were least likely to present. There was an increase in the total number of troponins and echocardiograms ordered during peak COVID-19 across both sexes, but females were still less likely to have these tests ordered across all timepoints. The number of coronary angiograms did not increase during peak COVID-19, and females were less likely to undergo coronary angiogram during all timepoints. Finally, females with chest pain were less likely to be diagnosed with acute myocardial infarction (AMI) during all timepoints, while in-hospital deaths were similar between males and females during all timepoints. Conclusions: During COVID-19, females, especially Asian females, were less likely to present to the ED for chest pain. Non-White patients were less likely to present to the ED compared to White patients prior to and during the pandemic. Disparities in management and outcomes of chest pain encounters remained similar to pre-COVID-19, with females receiving less cardiac workup and AMI diagnoses than males, but in-hospital mortality remaining similar between groups and timepoints.

2.
FASEB J ; 38(5): e23524, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38466191

RESUMEN

The pathophysiology of osteoporosis is significantly influenced by the impaired functioning of osteoblasts, which is particularly caused by oxidative stress. Nevertheless, the underlying mechanisms responsible for this phenomenon are still not well understood. The objective of this study was to elucidate the impact of fibroblast growth factor 7 (FGF7) on the behavior of osteoblasts under conditions of oxidative stress. The osteoblast-like MC3T3 cells were pretreated with recombinant FGF7 in the presence of oxidative stress induced by hydrogen peroxide (H2 O2 ). We first provided the evidence that the endogenous FGF7 was significantly increased in osteoblasts in response to the increased H2 O2 levels. Recombined FGF7 demonstrated a remarkable capacity to resist the detrimental effects of H2 O2 -induced oxidative stress, including the increase in cell apoptosis, decrease in osteoblast viability, and impairment in osteogenic differentiation capacity, on osteoblasts. Furthermore, we extensively explored the mechanism underlying these protective effects and discovered a remarkable modulation of reactive oxygen species (ROS) homeostasis in H2 O2 -treated cells following the pronounced expression of FGF7, which significantly differed from the control group. Additionally, we observed that FGF7 exerted partial preservation on both the morphology and function of mitochondria when exposed to oxidative stress conditions. Furthermore, FGF7 exhibited the ability to enhance the activation of the p38/MAPK signaling pathway while concurrently suppressing the JNK/MAPK signaling pathway in response to oxidative stress. These results underscore the promising role and underlying mechanisms of FGF7 in preserving osteoblast homeostasis in the face of oxidative stress.


Asunto(s)
Factor 7 de Crecimiento de Fibroblastos , Osteogénesis , Mitocondrias , Osteoblastos , Estrés Oxidativo , Línea Celular , Animales , Ratones
3.
Front Cell Infect Microbiol ; 13: 1157368, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37180439

RESUMEN

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a phenotype of liver diseases associated with metabolic syndrome. The pathogenesis MAFLD remains unclear. The liver maintains is located near the intestine and is physiologically interdependent with the intestine via metabolic exchange and microbial transmission, underpinning the recently proposed "oral-gut-liver axis" concept. However, little is known about the roles of commensal fungi in the disease development. This study aimed to characterize the alterations of oral and gut mycobiota and their roles in MAFLD. Twenty-one MAFLD participants and 20 healthy controls were enrolled. Metagenomics analyses of saliva, supragingival plaques, and feces revealed significant alterations in the gut fungal composition of MAFLD patients. Although no statistical difference was evident in the oral mycobiome diversity within MAFLD and healthy group, significantly decreased diversities were observed in fecal samples of MAFLD patients. The relative abundance of one salivary species, five supragingival species, and seven fecal species was significantly altered in MAFLD patients. Twenty-two salivary, 23 supragingival, and 22 fecal species were associated with clinical parameters. Concerning the different functions of fungal species, pathways involved in metabolic pathways, biosynthesis of secondary metabolites, microbial metabolism in diverse environments, and carbon metabolism were abundant both in the oral and gut mycobiomes. Moreover, different fungal contributions in core functions were observed between MAFLD patients and the healthy controls, especially in the supragingival plaque and fecal samples. Finally, correlation analysis between oral/gut mycobiome and clinical parameters identified correlations of certain fungal species in both oral and gut niches. Particularly, Mucor ambiguus, which was abundant both in saliva and feces, was positively correlated with body mass index, total cholesterol, low-density lipoprotein, alanine aminotransferase, and aspartate aminotransferase, providing evidence of a possible "oral-gut-liver" axis. The findings illustrate the potential correlation between core mycobiome and the development of MAFLD and could propose potential therapeutic strategies.


Asunto(s)
Microbioma Gastrointestinal , Micobioma , Enfermedad del Hígado Graso no Alcohólico , Humanos , Hongos/genética , Heces/microbiología , Saliva
4.
Mol Genet Genomic Med ; 11(5): e2147, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36795372

RESUMEN

BACKGROUND: Hemophilia B (HB), a rare bleeding disorder, shows X-linked recessive inheritance and is caused by heterogeneous variants in the FIX gene (F9) encoding coagulation factor IX (FIX). This study aimed to investigate the molecular pathogenesis of a novel Met394Thr variant causing HB. METHODS: We used Sanger sequencing to analyze F9 sequence variants in members of a Chinese family with moderate HB. Subsequently, we performed in vitro experiments on the identified novel FIX-Met394Thr variant. In addition, we performed bioinformatics analysis of the novel variant. RESULTS: We identified a novel missense variant (c.1181T>C, p.Met394Thr) in a Chinese family with moderate HB in the proband. The proband's mother and grandmother were carriers for the variant. The identified FIX-Met394Thr variant did not affect the transcription of F9 and the synthesis and secretion of FIX protein. The variant may, therefore, affect the physiological function of FIX protein by disrupting its spatial conformation. In addition, another variant (c.88+75A>G) in intron 1 of F9 was identified in the grandmother, which may also affect FIX protein function. CONCLUSION: We identified FIX-Met394Thr as a novel causative variant of HB. Further understanding of the molecular pathogenesis underlying FIX deficiency may guide novel strategies for precision HB therapy.


Asunto(s)
Hemofilia A , Hemofilia B , Humanos , Factor IX/genética , Familia , Hemofilia B/genética , Mutación Missense
5.
Stem Cell Res ; 60: 102682, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35123343

RESUMEN

The lack of coagulation factor VIII in patient with nonsense mutation hemophilia A leads to varying degrees of bleeding symptoms, and long-term use of alternative therapies can produce inhibitors that affect the efficacy. In this study, human induced pluripotent stem cells (iPSCs) of hemophilia A were generated by reprogramming of urine cells. Human urine cells (HUCs) were isolated by collecting patients' mid-stream urine, and cultured to good state in urine medium. Then, the HUCs were transfected with PEP4-EO2S-ET2K and pCEP4-M2L, and iPSCs were obtained in the medium without trophoblast cells and the composition was determined. Finally, alkaline phosphatase staining, karyotype analysis, immunofluorescence staining and teratoma were used to verify that we successfully reprogrammed hemophilia A-specific human induced pluripotent stem cells from patients' urine cells, providing a safe and effective cell model for the study of molecular mechanism and related treatment of hemophilia.


Asunto(s)
Hemofilia A , Células Madre Pluripotentes Inducidas , Diferenciación Celular , Factor VIII/genética , Hemofilia A/genética , Hemofilia A/terapia , Humanos , Mutación/genética
6.
Stem Cell Res Ther ; 13(1): 77, 2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35193674

RESUMEN

BACKGROUND: Controlling the adipo-osteogenic lineage commitment of bone marrow mesenchymal stem cell (BMSC) in favor of osteogenesis is considered a promising approach for bone regeneration and repair. Accumulating evidence indicates that oxidative phosphorylation (OXPHOS) is involved in regulating cell fate decisions. As an essential cofactor for OXPHOS, nicotinamide adenine dinucleotide (NAD) has been shown to correlate with the differentiation of stem cells. However, whether NAD manipulates BMSC lineage commitment through OXPHOS remains elusive. Therefore, it is critical to investigate the potential role of NAD on energy metabolism in mediating BMSC lineage commitment. METHODS: In this study, the mitochondrial respiration and intracellular NAD+ level were firstly compared between osteogenic and adipogenic cells. For validating the role of NAD in mitochondrial OXPHOS, the inhibitor of NAD+ salvage pathway FK866 and activator P7C3 were used to manipulate the NAD+ level during osteogenesis. Furthermore, a murine femur fracture model was established to evaluate the effect of FK866 on bone fracture repair. RESULTS: We elucidated that osteogenic committed BMSCs exhibited increased OXPHOS activity and a decreased glycolysis accompanied by an elevated intracellular NAD+ level. In contrast, adipogenic committed BMSCs showed little change in OXPHOS but an upregulated activity in glycolysis and a decline in intracellular NAD+ level in vitro. Moreover, attenuates of NAD+ via salvage pathway in BMSCs diminished osteogenic commitment due to mitochondria dysfunction and reduced activity of OXPHOS. The cells were rescued by supplementing with nicotinamide mononucleotide. In addition, treatment with NAD+ inhibitor FK866 impaired bone fracture healing in vivo. CONCLUSION: Our data reveals NAD+-mediated mitochondrial OXPHOS is indispensable for osteogenic commitment in BMSCs and bone repair, which might provide a potential therapeutic target for bone repair and regeneration.


Asunto(s)
Fracturas Óseas , Células Madre Mesenquimatosas , Animales , Diferenciación Celular , Fracturas Óseas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Ratones , NAD/metabolismo , Osteogénesis , Fosforilación Oxidativa
7.
Front Cell Dev Biol ; 9: 771336, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34881243

RESUMEN

The imbalance between bone formation and bone resorption causes osteoporosis, which leads to severe bone fractures. It is known that increases in osteoclast numbers and activities are the main reasons for increasing bone resorption. Although extensive studies have investigated the regulation of osteoclastogenesis of bone marrow macrophages (BMMs), new pharmacological avenues still need to be unveiled for clinical purpose. Wnt ligands have been widely demonstrated as stimulators of bone formation; however, the inhibitory effect of the Wnt pathway in osteoclastogenesis is largely unknown. Here, we demonstrate that Wnt7b, a potent Wnt ligand that enhances bone formation and increases bone mass, also abolishes osteoclastogenesis in vitro. Importantly, enforced expression of Wnt in bone marrow macrophage lineage cells significantly disrupts osteoclast formation and activity, which leads to a dramatic increase in bone mass. Mechanistically, Wnt7b impacts the glucose metabolic process and AKT activation during osteoclastogenesis. Thus, we demonstrate that Wnt7b diminishes osteoclast formation, which will be beneficial for osteoporosis therapy in the future.

8.
J Cell Mol Med ; 25(22): 10454-10465, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34626080

RESUMEN

Emerging evidence indicates extensive oxidative stress is a consequence of obesity which impairs bone formation. Glutathione peroxidase 7 (GPX7) is a conserved endoplasmic reticulum (ER) retention protein, lacking of which causes accumulation of reactive oxygen species (ROS) and promotes adipogenesis. Since the imbalance between osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cell (BMSC) leads to severe bone diseases such as osteoporosis, it is critical to investigate the potential protective role of Gpx7 in osteogenesis. Here, we provide evidence that deficiency of Gpx7 reduces osteogenesis, but increases adipogenesis in both human BMSCs (hBMSCs) and mouse mesenchymal stem cell line. Interestingly, further studies indicate this defect can be alleviated by the ER stress antagonist, but not the ROS inhibitor, unveiling an unexpected finding that, unlike adipogenesis, lacking of Gpx7 inhibits osteogenesis mediating by induced ER stress instead of enhanced ROS. Furthermore, the mTOR signalling pathway is found down-regulation during osteogenic differentiation in Gpx7-deficient condition, which can be rescued by relief of ER stress. Taken together, for the first time we identify a novel function of Gpx7 in BMSCs' osteogenic differentiation and indicate that Gpx7 may protect against osteoporotic deficits in humans through ER stress and mTOR pathway interplay.


Asunto(s)
Estrés del Retículo Endoplásmico , Glutatión Peroxidasa/genética , Células Madre Mesenquimatosas/metabolismo , Osteogénesis/genética , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Apoptosis/genética , Biomarcadores , Ciclo Celular/genética , Diferenciación Celular/genética , Células Cultivadas , Regulación del Desarrollo de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Inmunohistoquímica , Masculino , Células Madre Mesenquimatosas/citología , Ratones , Especies Reactivas de Oxígeno/metabolismo
9.
Int J Biol Sci ; 17(14): 3862-3874, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34671204

RESUMEN

Fibroblast growth factors (FGFs) include a large family of growth factors that play a critical role in maintaining bone homeostasis, but the specific role of its members such as FGF7 does not well understand. Osteoblasts are a kind of major cells essential for bone formation. Osteoblasts interact with one another to create the unique structure of osteons. The well-connected osteons constitute the cortical bone. As an early osteocyte marker that triggers actin cytoskeleton dynamics, E11 is essential for osteoblasts' dendrites formation. However, the upstream which regulates E11 is mainly unknown. The purpose of this study was to examine the influence of FGF7 on the expression and the distribution of E11 in osteoblasts, which mediated osteoblasts' processes formation and gap junctional intercellular communication (GJIC) partly through connexin43 (Cx43). We first demonstrated that FGF7 increased the expression of E11 in osteoblasts. We then showed that FGF7 promoted osteoblasts' dendrites elongation and functional gap junctions formation. Furthermore, E11 interacted directly with Cx43 in primary osteoblasts. MAPK pathway and PI3K-AKT pathway were involved in the effect of FGF7. Our results shed light on the unique role of FGF7 on osteoblasts, which may indicate that FGF7 plays a more significant role in the later stages of bone development and homeostasis.


Asunto(s)
Comunicación Celular/fisiología , Conexina 43/metabolismo , Factor 7 de Crecimiento de Fibroblastos/fisiología , Glicoproteínas de Membrana/metabolismo , Células 3T3 , Animales , Ligandos , Sistema de Señalización de MAP Quinasas , Ratones , Osteoblastos/metabolismo
10.
Elife ; 82019 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-31486771

RESUMEN

Cultured mouse peritoneal macrophages release large numbers of ~30-nm cholesterol-rich particles. Here, we show that those particles represent fragments of the plasma membrane that are pulled away and left behind during the projection and retraction of filopodia and lamellipodia. Consistent with this finding, the particles are enriched in proteins found in focal adhesions, which attach macrophages to the substrate. The release of particles is abolished by blocking cell movement (either by depolymerizing actin with latrunculin A or by inhibiting myosin II with blebbistatin). Confocal microscopy and NanoSIMS imaging studies revealed that the plasma membrane-derived particles are enriched in 'accessible cholesterol' (a mobile pool of cholesterol detectable with the modified cytolysin ALO-D4) but not in sphingolipid-sequestered cholesterol [a pool detectable with ostreolysin A (OlyA)]. The discovery that macrophages release cholesterol-rich particles during cellular locomotion is likely relevant to cholesterol efflux and could contribute to extracellular cholesterol deposition in atherosclerotic plaques.


Asunto(s)
Membrana Celular/metabolismo , Movimiento Celular , Micropartículas Derivadas de Células/química , Micropartículas Derivadas de Células/metabolismo , Colesterol/análisis , Macrófagos Peritoneales/metabolismo , Seudópodos/metabolismo , Animales , Células Cultivadas , Ratones , Proteínas/análisis
11.
Elife ; 82019 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-31169500

RESUMEN

GPIHBP1, a GPI-anchored protein of capillary endothelial cells, binds lipoprotein lipase (LPL) within the subendothelial spaces and shuttles it to the capillary lumen. GPIHBP1-bound LPL is essential for the margination of triglyceride-rich lipoproteins (TRLs) along capillaries, allowing the lipolytic processing of TRLs to proceed. In peripheral tissues, the intravascular processing of TRLs by the GPIHBP1-LPL complex is crucial for the generation of lipid nutrients for adjacent parenchymal cells. GPIHBP1 is absent from the capillaries of the brain, which uses glucose for fuel; however, GPIHBP1 is expressed in the capillaries of mouse and human gliomas. Importantly, the GPIHBP1 in glioma capillaries captures locally produced LPL. We use NanoSIMS imaging to show that TRLs marginate along glioma capillaries and that there is uptake of TRL-derived lipid nutrients by surrounding glioma cells. Thus, GPIHBP1 expression in gliomas facilitates TRL processing and provides a source of lipid nutrients for glioma cells.


Asunto(s)
Glioma/metabolismo , Lipoproteínas/metabolismo , Receptores de Lipoproteína/metabolismo , Animales , Encéfalo/irrigación sanguínea , Encéfalo/patología , Capilares/metabolismo , Isótopos de Carbono/metabolismo , Células Endoteliales/metabolismo , Ácidos Grasos/metabolismo , Glioma/irrigación sanguínea , Glioma/patología , Glioma/ultraestructura , Glucosa/metabolismo , Transportador de Glucosa de Tipo 1/metabolismo , Humanos , Lipoproteína Lipasa/metabolismo , Ratones Endogámicos C57BL , Triglicéridos/metabolismo
12.
BMC Oral Health ; 19(1): 22, 2019 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-30670012

RESUMEN

BACKGROUND: Extracellular matrix secretion and odontoblastic differentiation in human dental pulp stem cells (hDPSCs) are the cellular bases for reparative dentinogenesis. Osteomodulin (OMD) is a member of the small leucine-rich proteoglycan family distributed in the extracellular matrix but little is known about its role in osteo/odontogenic differentiation. The objective of this study was to investigate the role of OMD during osteo/odontoblastic differentiation of hDPSCs. METHODS: hDPSCs were selected using immune-magnetic beads and their capability of multi-differentiation was identified. OMD knockdown was achieved using short hairpin RNA (shRNA) lentivirus and was confirmed by western blot. Gene expression was measured by real-time qPCR and osteo/odontoblastic differentiation of hDPSCs was determined by alizarin red S staining. RESULTS: Compared with uninduced cells, the transcription of OMD was up-regulated by 35-fold at the late stage of osteo/odontogenic differentiation. shRNA-mediated gene silencing of OMD decreased the expression of odontoblastic genes, such as alkaline phosphatase (ALP), dentin matrix acidic phosphoprotein 1 (DMP1) and dentin sialophosphoprotein (DSPP). Besides, knockdown of OMD attenuated the mineralized nodules formation induced by osteo/odontogenic medium. CONCLUSIONS: These results implied that OMD may play a pivotal role in modulating the osteo/odontoblastic differentiation of hDPSCs.


Asunto(s)
Pulpa Dental , Proteínas de la Matriz Extracelular/metabolismo , Odontoblastos , Proteoglicanos/metabolismo , Fosfatasa Alcalina , Diferenciación Celular , Células Cultivadas , Humanos , Fosfoproteínas , Células Madre
13.
J Clin Lipidol ; 13(1): 62-69, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30514621

RESUMEN

BACKGROUND: Autoantibodies against glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) cause chylomicronemia by blocking the ability of GPIHBP1 to bind lipoprotein lipase (LPL) and transport the enzyme to its site of action in the capillary lumen. OBJECTIVE: A patient with multiple sclerosis developed chylomicronemia during interferon (IFN) ß1a therapy. The chylomicronemia resolved when the IFN ß1a therapy was discontinued. Here, we sought to determine whether the drug-induced chylomicronemia was caused by GPIHBP1 autoantibodies. METHODS: We tested plasma samples collected during and after IFN ß1a therapy for GPIHBP1 autoantibodies (by western blotting and with enzyme-linked immunosorbent assays). We also tested whether the patient's plasma blocked the binding of LPL to GPIHBP1 on GPIHBP1-expressing cells. RESULTS: During IFN ß1a therapy, the plasma contained GPIHBP1 autoantibodies, and those autoantibodies blocked GPIHBP1's ability to bind LPL. Thus, the chylomicronemia was because of the GPIHBP1 autoantibody syndrome. Consistent with that diagnosis, the plasma levels of GPIHBP1 and LPL were very low. After IFN ß1a therapy was stopped, the plasma triglyceride levels returned to normal, and GPIHBP1 autoantibodies were undetectable. CONCLUSION: The appearance of GPIHBP1 autoantibodies during IFN ß1a therapy caused chylomicronemia. The GPIHBP1 autoantibodies disappeared when the IFN ß1a therapy was stopped, and the plasma triglyceride levels fell within the normal range.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/inmunología , Hiperlipoproteinemia Tipo I/inmunología , Interferón beta/efectos adversos , Esclerosis Múltiple/terapia , Receptores de Lipoproteína/inmunología , Adulto , Autoanticuerpos/sangre , Enfermedades Autoinmunes/etiología , Células Cultivadas , Femenino , Humanos , Hiperlipoproteinemia Tipo I/etiología , Interferón beta/uso terapéutico , Esclerosis Múltiple/complicaciones , Unión Proteica , Síndrome , Triglicéridos/sangre , Privación de Tratamiento
14.
Biochem Biophys Res Commun ; 504(4): 899-902, 2018 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-30224066

RESUMEN

Heterogeneity in the metabolic properties of adipocytes in white adipose tissue has been well documented. We sought to investigate metabolic heterogeneity in adipocytes of brown adipose tissue (BAT), focusing on heterogeneity in nutrient uptake. To explore the possibility of metabolic heterogeneity in brown adipocytes, we used nanoscale secondary ion mass spectrometry (NanoSIMS) to quantify uptake of lipids in adipocytes interscapular BAT and perivascular adipose tissue (PVAT) after an intravenous injection of triglyceride-rich lipoproteins (TRLs) containing [2H]triglycerides (2H-TRLs). The uptake of deuterated lipids into brown adipocytes was quantified by NanoSIMS. We also examined 13C enrichment in brown adipocytes after administering [13C]glucose or 13C-labeled mixed fatty acids by gastric gavage. The uptake of 2H-TRLs-derived lipids into brown adipocytes was heterogeneous, with 2H enrichment in adjacent adipocytes varying by more than fourfold. We also observed substantial heterogeneity in 13C enrichment in adjacent brown adipocytes after administering [13C]glucose or [13C]fatty acids by gastric gavage. The uptake of nutrients by adjacent brown adipocytes within a single depot is variable, suggesting that there is heterogeneity in the metabolic properties of brown adipocytes.


Asunto(s)
Adipocitos Marrones/metabolismo , Nutrientes/farmacocinética , Espectrometría de Masa de Ion Secundario/métodos , Animales , Isótopos de Carbono/análisis , Ácidos Grasos/farmacocinética , Glucosa/farmacocinética , Lípidos/farmacocinética , Lipoproteínas/administración & dosificación , Lipoproteínas/farmacocinética , Ratones Endogámicos C57BL , Ratones Mutantes , Receptores de Lipoproteína/genética
15.
Proc Natl Acad Sci U S A ; 115(36): E8499-E8508, 2018 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-30127022

RESUMEN

Macrophages are generally assumed to unload surplus cholesterol through direct interactions between ABC transporters on the plasma membrane and HDLs, but they have also been reported to release cholesterol-containing particles. How macrophage-derived particles are formed and released has not been clear. To understand the genesis of macrophage-derived particles, we imaged mouse macrophages by EM and nanoscale secondary ion mass spectrometry (nanoSIMS). By scanning EM, we found that large numbers of 20- to 120-nm particles are released from the fingerlike projections (filopodia) of macrophages. These particles attach to the substrate, forming a "lawn" of particles surrounding macrophages. By nanoSIMS imaging we showed that these particles are enriched in the mobile and metabolically active accessible pool of cholesterol (detectable by ALO-D4, a modified version of a cholesterol-binding cytolysin). The cholesterol content of macrophage-derived particles was increased by loading the cells with cholesterol or by adding LXR and RXR agonists to the cell-culture medium. Incubating macrophages with HDL reduced the cholesterol content of macrophage-derived particles. We propose that release of accessible cholesterol-rich particles from the macrophage plasma membrane could assist in disposing of surplus cholesterol and increase the efficiency of cholesterol movement to HDL.


Asunto(s)
Micropartículas Derivadas de Células/metabolismo , Colesterol/metabolismo , Lipoproteínas HDL/metabolismo , Macrófagos/metabolismo , Animales , Micropartículas Derivadas de Células/ultraestructura , Lipoproteínas HDL/ultraestructura , Macrófagos/ultraestructura , Ratones , Ratones Noqueados , Microscopía Electrónica , Células RAW 264.7 , Espectrometría de Masa de Ion Secundario
16.
Elife ; 72018 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-30010539

RESUMEN

Anhydrobiotes are rare microbes, plants and animals that tolerate severe water loss. Understanding the molecular basis for their desiccation tolerance may provide novel insights into stress biology and critical tools for engineering drought-tolerant crops. Using the anhydrobiote, budding yeast, we show that trehalose and Hsp12, a small intrinsically disordered protein (sIDP) of the hydrophilin family, synergize to mitigate completely the inviability caused by the lethal stresses of desiccation. We show that these two molecules help to stabilize the activity and prevent aggregation of model proteins both in vivo and in vitro. We also identify a novel in vitro role for Hsp12 as a membrane remodeler, a protective feature not shared by another yeast hydrophilin, suggesting that sIDPs have distinct biological functions.


Asunto(s)
Deshidratación , Proteínas de Choque Térmico/metabolismo , Proteínas Intrínsecamente Desordenadas/metabolismo , Viabilidad Microbiana , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiología , Estrés Fisiológico , Trehalosa/metabolismo , Membrana Celular/metabolismo , Agregación Patológica de Proteínas/prevención & control
17.
Cell Metab ; 27(5): 1055-1066.e3, 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29719224

RESUMEN

The processing of triglyceride-rich lipoproteins (TRLs) in capillaries provides lipids for vital tissues, but our understanding of TRL metabolism is limited, in part because TRL processing and lipid movement have never been visualized. To investigate the movement of TRL-derived lipids in the heart, mice were given an injection of [2H]triglyceride-enriched TRLs, and the movement of 2H-labeled lipids across capillaries and into cardiomyocytes was examined by NanoSIMS. TRL processing and lipid movement in tissues were extremely rapid. Within 30 s, TRL-derived lipids appeared in the subendothelial spaces and in the lipid droplets and mitochondria of cardiomyocytes. Enrichment of 2H in capillary endothelial cells was not greater than in cardiomyocytes, implying that endothelial cells may not be a control point for lipid movement into cardiomyocytes. Remarkably, a deficiency of the putative fatty acid transport protein CD36, which is expressed highly in capillary endothelial cells, did not impede entry of TRL-derived lipids into cardiomyocytes.


Asunto(s)
Capilares/metabolismo , Lipólisis , Lipoproteínas/metabolismo , Miocitos Cardíacos/metabolismo , Triglicéridos/metabolismo , Animales , Antígenos CD36/metabolismo , Capilares/citología , Deuterio/química , Células Endoteliales/citología , Células Endoteliales/metabolismo , Gotas Lipídicas/metabolismo , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Miocitos Cardíacos/citología , Espectrometría de Masa de Ion Secundario/métodos
18.
Front Microbiol ; 9: 404, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29657574

RESUMEN

The luxS gene is present in a wide range of bacteria and is involved in many cellular processes. LuxS mutation can cause autoinducer(AI)-2 deficiency and methyl metabolism disorder. The objective of this study was to demonstrate that, in addition to AI-2-mediated quorum sensing (QS), methyl metabolism plays an important role in LuxS regulation in Streptococcus mutans. The sahH gene from Pseudomonas aeruginosa was amplified and introduced into the S. mutans luxS-null strain to complement the methyl metabolism disruption in a defective QS phenotype. The intracellular activated methyl cycle (AMC) metabolites [S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), homocysteine (HCY), and methionine] were quantified in wild-type S. mutans and its three derivatives to determine the metabolic effects of disrupting the AMC. Biofilm mass and structure, acid tolerance, acid production, exopolysaccharide synthesis of multispecies biofilms and the transcriptional level of related genes were determined. The results indicated that SAH and SAM were relatively higher in S. mutans luxS-null strain and S. mutans luxS null strain with plasmid pIB169 when cultured overnight, and HCY was significantly higher in S. mutans UA159. Consistent with the transcriptional profile, luxS deletion-mediated impairment of biofilm formation and acid tolerance was restored to wild-type levels using transgenic SahH. These results also suggest that methionine methyl metabolism contributes to LuxS regulation in S. mutans to a significant degree.

19.
Artículo en Inglés | MEDLINE | ID: mdl-29497601

RESUMEN

Pregnancy is a physiological process with pronounced hormonal fluctuations in females, and relatively little is known regarding how pregnancy influences the ecological shifts of supragingival microbiota. In this study, supragingival plaques and salivary hormones were collected from 11 pregnant women during pregnancy (P1, ≤14 weeks; P2, 20-25 weeks; P3, 33-37 weeks) and the postpartum period (P4, 6 weeks after childbirth). Seven non-pregnant volunteers were sampled at the same time intervals. The microbial genetic repertoire was obtained by 16S rDNA sequencing. Our results indicated that the Shannon diversity in P3 was significantly higher than in the non-pregnant group. The principal coordinates analysis showed distinct clustering according to gestational status, and the partial least squares discriminant analysis identified 33 genera that may contribute to this difference. There were differentially distributed genera, among which Neisseria, Porphyromonas, and Treponema were over-represented in the pregnant group, while Streptococcus and Veillonella were more abundant in the non-pregnant group. In addition, 53 operational taxonomic units were observed to have positive correlations with sex hormones in a redundancy analysis, with Prevotella spp. and Treponema spp. being most abundant. The ecological events suggest that pregnancy has a role in shaping an at-risk-for-harm microbiota and provide a basis for etiological studies of pregnancy-associated oral dysbiosis.


Asunto(s)
Biodiversidad , Encía/microbiología , Microbiota , Adulto , Femenino , Hormonas , Humanos , Metagenoma , Metagenómica , Filogenia , Embarazo , ARN Ribosómico 16S , Saliva/microbiología
20.
JCI Insight ; 2(20)2017 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-29046479

RESUMEN

In mammals, GPIHBP1 is absolutely essential for transporting lipoprotein lipase (LPL) to the lumen of capillaries, where it hydrolyzes the triglycerides in triglyceride-rich lipoproteins. In all lower vertebrate species (e.g., birds, amphibians, reptiles, fish), a gene for LPL can be found easily, but a gene for GPIHBP1 has never been found. The obvious question is whether the LPL in lower vertebrates is able to reach the capillary lumen. Using purified antibodies against chicken LPL, we showed that LPL is present on capillary endothelial cells of chicken heart and adipose tissue, colocalizing with von Willebrand factor. When the antibodies against chicken LPL were injected intravenously into chickens, they bound to LPL on the luminal surface of capillaries in heart and adipose tissue. LPL was released rapidly from chicken hearts with an infusion of heparin, consistent with LPL being located inside blood vessels. Remarkably, chicken LPL bound in a specific fashion to mammalian GPIHBP1. However, we could not identify a gene for GPIHBP1 in the chicken genome, nor could we identify a transcript for GPIHBP1 in a large chicken RNA-seq data set. We conclude that LPL reaches the capillary lumen in chickens - as it does in mammals - despite an apparent absence of GPIHBP1.


Asunto(s)
Capilares/metabolismo , Pollos/metabolismo , Lipoproteína Lipasa/metabolismo , Receptores de Lipoproteína/metabolismo , Tejido Adiposo/irrigación sanguínea , Tejido Adiposo/metabolismo , Animales , Anticuerpos , Células Endoteliales/metabolismo , Femenino , Cabras , Corazón , Heparina , Humanos , Inmunoglobulina G , Metabolismo de los Lípidos , Lipoproteína Lipasa/genética , Lipoproteínas/metabolismo , Masculino , Ratones , Receptores de Lipoproteína/análisis , Receptores de Lipoproteína/genética , Triglicéridos/metabolismo
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