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1.
J Endocr Soc ; 8(8): bvae125, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38974988

RESUMEN

Context: The rise in continuous glucose monitor (CGM) use has been characterized by widening disparities between the least and most socially marginalized. Given access barriers, there is limited CGM patient experience information that is inclusive of those with type 2 diabetes mellitus from socially marginalized backgrounds. Objective: To understand the CGM usage experience in the primary care setting across a US Medicaid population with type 2 diabetes at federally qualified health centers. Methods: This qualitative study used semi-structured phone interviews with 28 English- or Spanish-speaking participants prescribed the CGM who were enrolled in a US Medicaid program that subsidized CGMs. Audio recordings of interviews were transcribed and analyzed by reflective thematic analysis. Results: Twenty-eight participants (75% female, median age 56 years with interquartile-range 48-60 years) were interviewed. Participants were from different racial/ethnic backgrounds: 21% non-Hispanic White, 57% Hispanic, and 18% non-Hispanic Black. Participants primarily spoke English (68%) or Spanish (32%), and 53% reported 9 or fewer years of formal education. We identified 6 major themes: initial expectations and overcoming initiation barriers, convenience and ease promote daily use, increased knowledge leads to improved self-management, collaboration with provider and clinical team, improved self-reported outcomes, and barriers and burdens are generally tolerated. Conclusion: CGM use was experienced as easy to understand and viewed as a tool for diabetes self-efficacy. Expanded CGM access for socially marginalized patients with type 2 diabetes can enhance diabetes self-management to help mitigate diabetes outcome disparities.

2.
J Endocr Soc ; 8(5): bvae042, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38515583

RESUMEN

Context: Despite a high prevalence of obesity in the veteran population, antiobesity medications (AOMs) have been underused in the Veterans Health Administration. Real-world reports on outcomes when AOMs have been used in veterans is limited. Objective: To analyze weight loss outcomes from a local Veterans Health Administration pharmacotherapy-based weight management clinic (WMC). Methods: This was a retrospective cohort study of veterans enrolled in a local WMC for 15 months from August 2016 through September 2018 and followed through November 2019. Patients were offered 1 of 5 available AOMs based on their comorbidities. Factors associated with weight loss (5% or more weight loss) were assessed. Key results: A total of 159 patients were seen in a WMC, 149 (93.7%) veterans were prescribed an AOM, and 129 returned for follow-up. Overall, 61/129 (47%) patients achieved 5% or greater weight loss and 28/129 (22%) achieved 10% or greater weight loss within 15 months. Clinically significant weight loss (%) over the first 15 months was achieved with phentermine/topiramate ER (-6.3%) and liraglutide (-7.5%), but not with orlistat (-3.9%) and lorcaserin (-3.6%). Comorbid obstructive sleep apnea was negatively associated with achieving ≥5% weight loss. Conclusion: Phentermine/topiramate ER and liraglutide were found to be effective AOMs among veterans. Further work is needed to mitigate barriers to AOM initiation given the continued rise in obesity.

3.
Endocr Pract ; 30(4): 367-371, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38307456

RESUMEN

OBJECTIVE: There is a relative lack of consensus regarding the optimal management of hyperglycemia in patients receiving continuous enteral nutrition (EN), with or without a diagnosis of diabetes. METHODS: This retrospective study examined 475 patients (303 with known diabetes) hospitalized in critical care setting units in 2019 in a single center who received continuous EN. Rates of hypoglycemia, hyperglycemia, and glucose levels within the target range (70-180 mg/dL) were compared between patients with and without diabetes, and among patients treated with intermediate-acting (IA) biphasic neutral protamine Hagedorn 70/30, long-acting (LA) insulin, or rapid-acting insulin only. RESULTS: Among those with type 2 diabetes mellitus, IA and LA insulin regimens were associated with a significantly higher proportion of patient-days in the target glucose range and fewer hyperglycemic days. Level 1 (<70 mg/dL) and level 2 (<54 mg/dL) hypoglycemia occurred rarely, and there were no significant differences in level 2 hypoglycemia frequency across the different insulin regimens. CONCLUSION: Administration of IA and LA insulin can be safe and effective for those receiving insulin doses for EN-related hyperglycemia.


Asunto(s)
Diabetes Mellitus Tipo 2 , Hiperglucemia , Hipoglucemia , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/efectos adversos , Estudios Retrospectivos , Nutrición Enteral , Enfermedad Crítica/terapia , Glucemia , Insulina/efectos adversos , Hipoglucemia/inducido químicamente , Hipoglucemia/epidemiología , Hipoglucemia/tratamiento farmacológico , Insulina de Acción Prolongada/uso terapéutico , Hiperglucemia/tratamiento farmacológico , Hiperglucemia/prevención & control , Hiperglucemia/inducido químicamente , Glucosa/uso terapéutico , Insulina Isófana/efectos adversos
4.
Am J Physiol Lung Cell Mol Physiol ; 325(6): L711-L725, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37814796

RESUMEN

Chronic obstructive pulmonary disease (COPD) is characterized by nonresolving inflammation fueled by breach in the endothelial barrier and leukocyte recruitment into the airspaces. Among the ligand-receptor axes that control leukocyte recruitment, the full-length fractalkine ligand (CX3CL1)-receptor (CX3CR1) ensures homeostatic endothelial-leukocyte interactions. Cigarette smoke (CS) exposure and respiratory pathogens increase expression of endothelial sheddases, such as a-disintegrin-and-metalloproteinase-domain 17 (ADAM17, TACE), inhibited by the anti-protease α-1 antitrypsin (AAT). In the systemic endothelium, TACE cleaves CX3CL1 to release soluble CX3CL1 (sCX3CL1). During CS exposure, it is not known whether AAT inhibits sCX3CL1 shedding and CX3CR1+ leukocyte transendothelial migration across lung microvasculature. We investigated the mechanism of sCX3CL1 shedding, its role in endothelial-monocyte interactions, and AAT effect on these interactions during acute inflammation. We used two, CS and lipopolysaccharide (LPS) models of acute inflammation in transgenic Cx3cr1gfp/gfp mice and primary human endothelial cells and monocytes to study sCX3CL1-mediated CX3CR1+ monocyte adhesion and migration. We measured sCX3CL1 levels in plasma and bronchoalveolar lavage (BALF) of individuals with COPD. Both sCX3CL1 shedding and CX3CR1+ monocytes transendothelial migration were triggered by LPS and CS exposure in mice, and were significantly attenuated by AAT. The inhibition of monocyte-endothelial adhesion and migration by AAT was TACE-dependent. Compared with healthy controls, sCX3CL1 levels were increased in plasma and BALF of individuals with COPD, and were associated with clinical parameters of emphysema. Our results indicate that inhibition of sCX3CL1 as well as AAT augmentation may be effective approaches to decrease excessive monocyte lung recruitment during acute and chronic inflammatory states.NEW & NOTEWORTHY Our novel findings that AAT and other inhibitors of TACE, the sheddase that controls full-length fractalkine (CX3CL1) endothelial expression, may provide fine-tuning of the CX3CL1-CX3CR1 axis specifically involved in endothelial-monocyte cross talk and leukocyte recruitment to the alveolar space, suggests that AAT and inhibitors of sCX3CL1 signaling may be harnessed to reduce lung inflammation.


Asunto(s)
Quimiocina CX3CL1 , Enfisema Pulmonar , Animales , Humanos , Ratones , alfa 1-Antitripsina/farmacología , Comunicación Celular , Receptor 1 de Quimiocinas CX3C/metabolismo , Células Endoteliales/metabolismo , Endotelio/metabolismo , Inflamación/metabolismo , Ligandos , Lipopolisacáridos/farmacología , Lipopolisacáridos/metabolismo , Pulmón/metabolismo , Monocitos , Enfisema Pulmonar/metabolismo
5.
Diabetes Care ; 46(2): 391-398, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36480729

RESUMEN

OBJECTIVE: Current studies on continuous glucose monitor (CGM) uptake are revealing for significant barriers and inequities for CGM use among patients from socially underprivileged communities. This study explores the effect of full subsidies regardless of diabetes type on CGM uptake and HbA1c outcomes in a U.S. adult patient population on Medicaid. RESEARCH DESIGN AND METHODS: This retrospective cohort study examined 3,036 adults with diabetes enrolled in a U.S. Medicaid program that fully subsidized CGM. CGM uptake and adherence were assessed by CGM prescription and dispense data, including more than one fill and adherence by medication possession ratio (MPR). Multivariate logistic regression evaluated predictors of CGM uptake. Pre- and post-CGM use HbA1c were compared. RESULTS: CGM were very well received by both individuals with type 1 diabetes and individuals with type 2 diabetes with similar high fill adherence levels (mean MPR 0.78 vs. 0.72; P = 0.06). No significant difference in CGM uptake outcomes were noted among major racial/ethnic groups. CGM use was associated with improved HbA1c among those with type 2 diabetes (-1.2% [13.1 mmol/mol]; P < 0.001) that was comparable between major racial/ethnic groups and those with higher fill adherence achieved greater HbA1c reduction (-1.4% [15.3 mmol/mol]; P < 0.001) compared with those with lower adherence (-1.0% [10.9 mmol/mol]; P < 0.001). CONCLUSIONS: CGM uptake disparities can largely be overcome by eliminating CGM cost barriers. CGM use was associated with improved HbA1c across all major racial/ethnic groups, highlighting broad CGM appeal, utilization, and effectiveness across an underprivileged patient population.


Asunto(s)
Diabetes Mellitus Tipo 2 , Adulto , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hemoglobina Glucada , Estudios Retrospectivos , Medicaid , Automonitorización de la Glucosa Sanguínea , Glucemia
6.
J Am Soc Nephrol ; 34(2): 220-240, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36283811

RESUMEN

BACKGROUND: Translation shutdown is a hallmark of late-phase, sepsis-induced kidney injury. Methods for controlling protein synthesis in the kidney are limited. Reversing translation shutdown requires dephosphorylation of the eukaryotic initiation factor 2 (eIF2) subunit eIF2 α ; this is mediated by a key regulatory molecule, protein phosphatase 1 regulatory subunit 15A (Ppp1r15a), also known as GADD34. METHODS: To study protein synthesis in the kidney in a murine endotoxemia model and investigate the feasibility of translation control in vivo by boosting the protein expression of Ppp1r15a, we combined multiple tools, including ribosome profiling (Ribo-seq), proteomics, polyribosome profiling, and antisense oligonucleotides, and a newly generated Ppp1r15a knock-in mouse model and multiple mutant cell lines. RESULTS: We report that translation shutdown in established sepsis-induced kidney injury is brought about by excessive eIF2 α phosphorylation and sustained by blunted expression of the counter-regulatory phosphatase Ppp1r15a. We determined the blunted Ppp1r15a expression persists because of the presence of an upstream open reading frame (uORF). Overcoming this barrier with genetic and antisense oligonucleotide approaches enabled the overexpression of Ppp1r15a, which salvaged translation and improved kidney function in an endotoxemia model. Loss of this uORF also had broad effects on the composition and phosphorylation status of the immunopeptidome-peptides associated with the MHC-that extended beyond the eIF2 α axis. CONCLUSIONS: We found Ppp1r15a is translationally repressed during late-phase sepsis because of the existence of an uORF, which is a prime therapeutic candidate for this strategic rescue of translation in late-phase sepsis. The ability to accurately control translation dynamics during sepsis may offer new paths for the development of therapies at codon-level precision. PODCAST: This article contains a podcast at.


Asunto(s)
Lesión Renal Aguda , Endotoxemia , Animales , Ratones , Biosíntesis de Proteínas , Sistemas de Lectura Abierta , Factor 2 Eucariótico de Iniciación/genética , Factor 2 Eucariótico de Iniciación/metabolismo , Endotoxemia/complicaciones , Modelos Animales de Enfermedad , Lesión Renal Aguda/genética , Proteína Fosfatasa 1
7.
Radiol Case Rep ; 16(4): 824-828, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33552333

RESUMEN

Portal vein thrombosis (PVT) is an important cause of noncirrhotic portal hypertension. Noncancerous extrinsic compression of portal vein to drive PVT formation is rare, but important to identify. A 64-year-old female with idiopathic hepatic artery pseudoaneurysm (HAPA) rupture 7 months prior presented with acute-onset hematemesis and melena and was found to have prehepatic portal hypertensive variceal bleeding. Her HAPA-related retroperitoneal hematoma had resulted in portal vein compression, thrombosis, and cavernous transformation despite prompt stent graft placement across the ruptured HAPA, and required definitive treatment by transjugular intrahepatic portosystemic shunt creation with portal vein reconstruction utilizing a trans-splenic access. This case highlights the importance of interval abdominal imaging and hypercoagulability screening for noncirrhotic patients at-risk for PVT, which identified the patient as a heterozygous carrier of Factor V Leiden.

8.
JCI Insight ; 5(14)2020 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-32573489

RESUMEN

Cigarette smoking (CS) and genetic susceptibility determine the risk for development, progression, and severity of chronic obstructive pulmonary diseases (COPD). We posited that an incidental balanced reciprocal chromosomal translocation was linked to a patient's risk of severe COPD. We determined that 46,XX,t(1;4)(p13.1;q34.3) caused a breakpoint in the immunoglobulin superfamily member 3 (IGSF3) gene, with markedly decreased expression. Examination of COPDGene cohort identified 14 IGSF3 SNPs, of which rs1414272 and rs12066192 were directly and rs6703791 inversely associated with COPD severity, including COPD exacerbations. We confirmed that IGSF3 is a tetraspanin-interacting protein that colocalized with CD9 and integrin B1 in tetraspanin-enriched domains. IGSF3-deficient patient-derived lymphoblastoids exhibited multiple alterations in gene expression, especially in the unfolded protein response and ceramide pathways. IGSF3-deficient lymphoblastoids had high ceramide and sphingosine-1 phosphate but low glycosphingolipids and ganglioside levels, and they were less apoptotic and more adherent, with marked changes in multiple TNFRSF molecules. Similarly, IGSF3 knockdown increased ceramide in lung structural cells, rendering them more adherent, with impaired wound repair and weakened barrier function. These findings suggest that, by maintaining sphingolipid and membrane receptor homeostasis, IGSF3 is required for cell mobility-mediated lung injury repair. IGSF3 deficiency may increase susceptibility to CS-induced lung injury in COPD.


Asunto(s)
Fumar Cigarrillos/genética , Predisposición Genética a la Enfermedad , Inmunoglobulinas/genética , Proteínas de la Membrana/genética , Enfermedad Pulmonar Obstructiva Crónica/genética , Translocación Genética/genética , Apoptosis/genética , Adhesión Celular/genética , Movimiento Celular/genética , Cromosomas Humanos Par 1/genética , Cromosomas Humanos Par 4/genética , Fumar Cigarrillos/efectos adversos , Femenino , Regulación de la Expresión Génica/genética , Humanos , Integrina beta1/genética , Masculino , Persona de Mediana Edad , Mutación/genética , Polimorfismo de Nucleótido Simple/genética , Enfermedad Pulmonar Obstructiva Crónica/inducido químicamente , Enfermedad Pulmonar Obstructiva Crónica/patología , Índice de Severidad de la Enfermedad , Tetraspanina 29/genética
9.
Sci Rep ; 10(1): 280, 2020 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-31937874

RESUMEN

Chronic hypoxia leads to pathologic remodeling of the pulmonary vasculature and pulmonary hypertension (PH). The antioxidant enzyme extracellular superoxide dismutase (SOD3) protects against hypoxia-induced PH. Hyaluronan (HA), a ubiquitous glycosaminoglycan of the lung extracellular matrix, is rapidly recycled at sites of vessel injury and repair. We investigated the hypothesis that SOD3 preserves HA homeostasis by inhibiting oxidative and enzymatic hyaluronidase-mediated HA breakdown. In SOD3-deficient mice, hypoxia increased lung hyaluronidase expression and activity, hyaluronan fragmentation, and effacement of HA from the vessel wall of small pulmonary arteries. Hyaluronan fragmentation corresponded to hypoxic induction of the cell surface hyaluronidase-2 (Hyal2), which was localized in the vascular media. Human pulmonary artery smooth muscle cells (HPASMCs) demonstrated hypoxic induction of Hyal2 and SOD-suppressible hyaluronidase activity, congruent to our observations in vivo. Fragmentation of homeostatic high molecular weight HA promoted HPASMC proliferation in vitro, whereas pharmacologic inhibition of hyaluronidase activity prevented hypoxia- and oxidant-induced proliferation. Hypoxia initiates SOD3-dependent alterations in the structure and regulation of hyaluronan in the pulmonary vascular extracellular matrix. These changes occurred soon after hypoxia exposure, prior to appearance of PH, and may contribute to the early pathogenesis of this disease.


Asunto(s)
Ácido Hialurónico/metabolismo , Hipertensión Pulmonar/patología , Hipoxia , Animales , Hipoxia de la Célula , Proliferación Celular/efectos de los fármacos , Femenino , Humanos , Ácido Hialurónico/análisis , Ácido Hialurónico/farmacología , Hialuronoglucosaminidasa/antagonistas & inhibidores , Hialuronoglucosaminidasa/genética , Hialuronoglucosaminidasa/metabolismo , Hipertensión Pulmonar/metabolismo , Pulmón/enzimología , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Miocitos del Músculo Liso/citología , Miocitos del Músculo Liso/metabolismo , Arteria Pulmonar/citología , Arteria Pulmonar/enzimología , Superóxido Dismutasa/deficiencia , Superóxido Dismutasa/genética , Regulación hacia Arriba
10.
Am J Respir Crit Care Med ; 200(9): 1113-1125, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31265321

RESUMEN

Rationale: The loss of pulmonary endothelial cells in emphysema is associated with increased lung ceramide. Ceramide perturbations may cause adaptive alterations in other bioactive sphingolipids, with pathogenic implications. We previously reported a negative correlation between emphysema and circulating glycosphingolipids (GSLs). Glucosylceramide (GlcCer), the initial GSL synthesized from ceramide by GCS (GlcCer synthase), is required for embryonic survival, but its role in the lung is unknown.Objectives: To determine if cigarette smoke (CS) alters lung GlcCer and to elucidate the role of GCS in lung endothelial cell fate.Methods: GlcCer was measured by tandem mass spectrometry in BAL fluid of CS- or elastase-exposed mice, and GCS was detected by Western blotting in chronic obstructive pulmonary disease lungs and CS extract-exposed primary human lung microvascular endothelial cells (HLMVECs). The role of GlcCer and GCS on mTOR (mammalian target of rapamycin) signaling, autophagy, lysosomal function, and cell death were studied in HLMVECs with or without CS exposure.Measurements and Main Results: Mice exposed to chronic CS or to elastase, and patients with chronic obstructive pulmonary disease, exhibited significantly decreased lung GlcCer and GCS. In mice, lung GlcCer levels were negatively correlated with airspace size. GCS inhibition in HLMVEC increased lysosomal pH, suppressed mTOR signaling, and triggered autophagy with impaired lysosomal degradation and apoptosis, recapitulating CS effects. In turn, increasing GlcCer by GCS overexpression in HLMVEC improved autophagic flux and attenuated CS-induced apoptosis.Conclusions: Decreased GSL production in response to CS may be involved in emphysema pathogenesis, associated with autophagy with impaired lysosomal degradation and lung endothelial cell apoptosis.


Asunto(s)
Células Endoteliales/patología , Glucosilceramidas/metabolismo , Enfisema Pulmonar/etiología , Enfisema Pulmonar/metabolismo , Fumar/efectos adversos , Animales , Autofagia , Técnicas de Cultivo de Célula , Muerte Celular , Modelos Animales de Enfermedad , Ratones , Enfisema Pulmonar/patología
11.
Biochem Biophys Rep ; 17: 114-121, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30623115

RESUMEN

During inflammation, the covalent linking of the ubiquitous extracellular polysaccharide hyaluronan (HA) with the heavy chains (HC) of the serum protein inter alpha inhibitor (IαI) is exclusively mediated by the enzyme tumor necrosis factor α (TNFα)-stimulated-gene-6 (TSG-6). While significant advances have been made regarding how HC-modified HA (HC-HA) is an important regulator of inflammation, it remains unclear why HC-HA plays a critical role in promoting survival in intraperitoneal lipopolysaccharide (LPS)-induced endotoxemia while exerting only a modest role in the outcomes following intratracheal exposure to LPS. To address this gap, the two models of intraperitoneal LPS-induced endotoxic shock and intratracheal LPS-induced acute lung injury were directly compared in TSG-6 knockout mice and littermate controls. HC-HA formation, endogenous TSG-6 activity, and inflammatory markers were assessed in plasma and lung tissue. TSG-6 knockout mice exhibited accelerated mortality during endotoxic shock. While both intraperitoneal and intratracheal LPS induced HC-HA formation in lung parenchyma, only systemically-induced endotoxemia increased plasma TSG-6 levels and intravascular HC-HA formation. Cultured human lung microvascular endothelial cells secreted TSG-6 in response to both TNFα and IL1ß stimulation, indicating that, in addition to inflammatory cells, the endothelium may secrete TSG-6 into circulation during systemic inflammation. These data show for the first time that LPS-induced systemic inflammation is uniquely characterized by significant vascular induction of TSG-6 and HC-HA, which may contribute to improved outcomes of endotoxemia.

12.
Am J Physiol Lung Cell Mol Physiol ; 316(3): L558-L566, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30628489

RESUMEN

Proapoptotic and monocyte chemotactic endothelial monocyte-activating protein 2 (EMAPII) is released extracellularly during cigarette smoke (CS) exposure. We have previously demonstrated that, when administered intratracheally during chronic CS exposures, neutralizing rat antibodies to EMAPII inhibited endothelial cell apoptosis and lung inflammation and reduced airspace enlargement in mice (DBA/2J strain). Here we report further preclinical evaluation of EMAPII targeting using rat anti-EMAPII antibodies via either nebulization or subcutaneous injection. Both treatment modalities efficiently ameliorated emphysema-like disease in two different strains of CS-exposed mice, DBA/2J and C57BL/6. Of relevance for clinical applicability, this treatment showed therapeutic and even curative potential when administered either during or following CS-induced emphysema development, respectively. In addition, a fully humanized neutralizing anti-EMAPII antibody administered subcutaneously to mice during CS exposure retained anti-apoptotic and anti-inflammatory effects similar to that of the parent rat antibody. Furthermore, humanized anti-EMAPII antibody treatment attenuated CS-induced autophagy and restored mammalian target of rapamycin signaling in the lungs of mice, despite ongoing CS exposure. Together, our results demonstrate that EMAPII secretion is involved in CS-induced lung inflammation and cell injury, including apoptosis and autophagy, and that a humanized EMAPII neutralizing antibody may have therapeutic potential in emphysema.


Asunto(s)
Anticuerpos Neutralizantes/farmacología , Lesión Pulmonar/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfisema Pulmonar/tratamiento farmacológico , Fumar/efectos adversos , Animales , Autofagia/efectos de los fármacos , Citocinas/efectos de los fármacos , Lesión Pulmonar/metabolismo , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Proteínas de Neoplasias/efectos de los fármacos , Neumonía/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Enfisema Pulmonar/metabolismo , Proteínas de Unión al ARN/efectos de los fármacos
13.
Respir Res ; 19(1): 107, 2018 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-29855321

RESUMEN

BACKGROUND: Several inflammatory lung diseases display abundant presence of hyaluronic acid (HA) bound to heavy chains (HC) of serum protein inter-alpha-inhibitor (IαI) in the extracellular matrix. The HC-HA modification is critical to neutrophil sequestration in liver sinusoids and to survival during experimental lipopolysaccharide (LPS)-induced sepsis. Therefore, the covalent HC-HA binding, which is exclusively mediated by tumor necrosis factor α (TNFα)-stimulated-gene-6 (TSG-6), may play an important role in the onset or the resolution of lung inflammation in acute lung injury (ALI) induced by respiratory infection. METHODS: Reversible ALI was induced by a single intratracheal instillation of LPS or Pseudomonas aeruginosa in mice and outcomes were studied for up to six days. We measured in the lung or the bronchoalveolar fluid HC-HA formation, HA immunostaining localization and roughness, HA fragment abundance, and markers of lung inflammation and lung injury. We also assessed TSG-6 secretion by TNFα- or LPS-stimulated human alveolar macrophages, lung fibroblast Wi38, and bronchial epithelial BEAS-2B cells. RESULTS: Extensive HC-modification of lung HA, localized predominantly in the peri-broncho-vascular extracellular matrix, was notable early during the onset of inflammation and was markedly decreased during its resolution. Whereas human alveolar macrophages secreted functional TSG-6 following both TNFα and LPS stimulation, fibroblasts and bronchial epithelial cells responded to only TNFα. Compared to wild type, TSG-6-KO mice, which lacked HC-modified HA, exhibited modest increases in inflammatory cells in the lung, but no significant differences in markers of lung inflammation or injury, including histopathological lung injury scores. CONCLUSIONS: Respiratory infection induces rapid HC modification of HA followed by fragmentation and clearance, with kinetics that parallel the onset and resolution phase of ALI, respectively. Alveolar macrophages may be an important source of pulmonary TSG-6 required for HA remodeling. The formation of HC-modified HA had a minor role in the onset, severity, or resolution of experimental reversible ALI induced by respiratory infection with gram-negative bacteria.


Asunto(s)
Lesión Pulmonar Aguda/metabolismo , alfa-Globulinas/metabolismo , Ácido Hialurónico/metabolismo , Macrófagos Alveolares/metabolismo , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/microbiología , Animales , Células Cultivadas , Humanos , Lipopolisacáridos/toxicidad , Macrófagos Alveolares/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Transgénicos , Depuración Mucociliar/efectos de los fármacos , Depuración Mucociliar/fisiología , Unión Proteica , Factores de Tiempo
14.
Stem Cells Dev ; 26(20): 1468-1476, 2017 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-28825379

RESUMEN

Alpha-1 antitrypsin (A1AT), a circulating acute-phase reactant antiprotease, is produced and secreted by cells of endodermal epithelial origin, primarily hepatocytes, and by immune cells. Deficiency of A1AT is associated with increased risk of excessive lung inflammation and injury, especially following chronic cigarette smoke (CS) exposure. Exogenous administration of mesenchymal progenitor cells, including adipose tissue-derived stromal/stem cells (ASC), alleviates CS-induced lung injury through paracrine effectors such as growth factors. It is unknown, however, if mesodermal ASC can secrete functional A1AT and if CS exposure affects their A1AT production. Human ASC collected via liposuction from nonsmoking or smoking donors were stimulated by inflammatory cytokines tumor necrosis alpha (TNFα), oncostatin M (OSM), and/or dexamethasone (DEX) or were exposed to sublethal concentrations of ambient air control or CS extract (0.5%-2%). We detected minimal expression and secretion of A1AT by cultured ASC during unstimulated conditions, which significantly increased following stimulation with TNFα or OSM. Furthermore, TNFα and OSM synergistically enhanced A1AT expression and secretion, which were further increased by DEX. The A1AT transcript variant produced by stimulated ASC resembled that produced by bronchial epithelial cells rather than the variant produced by monocytes/macrophages. While the cigarette smoking status of the ASC donor had no measurable effect on the ability of ASC to induce A1AT expression, active exposure to CS extract markedly reduced A1AT expression and secretion by cultured ASC, as well as human tracheobronchial epithelial cells. ASC-secreted A1AT covalently complexed with neutrophil elastase in control ASC, but not in cells transfected with A1AT siRNA. Undifferentiated ASC may require priming to secrete functional A1AT, a potent antiprotease that may be relevant to stem cell therapeutic effects.


Asunto(s)
Tejido Adiposo/citología , Diferenciación Celular , Oncostatina M/farmacología , Factor de Necrosis Tumoral alfa/farmacología , alfa 1-Antitripsina/metabolismo , Bronquios/citología , Diferenciación Celular/efectos de los fármacos , Línea Celular , Fumar Cigarrillos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Humanos , Elastasa de Leucocito/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo , alfa 1-Antitripsina/genética
15.
Ann Am Thorac Soc ; 13 Suppl 4: S311-6, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27564666

RESUMEN

Animal models of disease help accelerate the translation of basic science discoveries to the bedside, because they permit experimental interrogation of mechanisms at relatively high throughput, while accounting for the complexity of an intact organism. From the groundbreaking observation of emphysema-like alveolar destruction after direct instillation of elastase in the lungs to the more clinically relevant model of airspace enlargement induced by chronic exposure to cigarette smoke, animal models have advanced our understanding of alpha-1 antitrypsin (AAT) function. Experimental in vivo models that, at least in part, replicate clinical human phenotypes facilitate the translation of mechanistic findings into individuals with chronic obstructive pulmonary disease and with AAT deficiency. In addition, unexpected findings of alveolar enlargement in various transgenic mice have led to novel hypotheses of emphysema development. Previous challenges in manipulating the AAT genes in mice can now be overcome with new transgenic approaches that will likely advance our understanding of functions of this essential, lung-protective serine protease inhibitor (serpin).


Asunto(s)
Modelos Animales de Enfermedad , Enfisema Pulmonar/metabolismo , alfa 1-Antitripsina/metabolismo , Animales , Ratones , Ratones Transgénicos , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , alfa 1-Antitripsina/genética , Deficiencia de alfa 1-Antitripsina/genética , Deficiencia de alfa 1-Antitripsina/metabolismo
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