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1.
Cell Immunol ; 383: 104657, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36603504

RESUMEN

Mature IL-33 (MIL33) acting through its receptor, ST2, is known to regulate fibrosis. The precursor, full-length IL-33 (FLIL33), may function differently from MIL33 and independently of ST2. Here we report that genetic deletion of either IL-33 or ST2 attenuates pulmonary fibrosis in the bleomycin model, as does Cre-induced IL-33 deficiency in response to either acute or chronic bleomycin challenge. However, adenovirus-mediated gene delivery of FLIL33, but not MIL33, to the lungs of either wild-type or ST2-deficient mice potentiates the profibrotic effect of bleomycin without inducing a Th2 phenotype. In cultured mouse lung cells, FLIL33 overexpression induces moderate and distinct transcriptomic changes compared with a robust response induced by MIL33, whereas ST2 deletion abrogates the effects of both IL-33 forms. Thus, FLIL33 may contribute to fibrosis in an ST2-independent, Th2-independent, non-transcriptomic fashion, suggesting that pharmacological targeting of both FLIL33 and MIL33 may prove efficacious in patients with pulmonary fibrosis.


Asunto(s)
Fibrosis Pulmonar , Ratones , Animales , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/genética , Interleucina-33/genética , Proteína 1 Similar al Receptor de Interleucina-1/genética , Fibrosis , Bleomicina , Ratones Endogámicos C57BL
2.
Am J Physiol Lung Cell Mol Physiol ; 310(10): L940-54, 2016 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-26993524

RESUMEN

Idiopathic pulmonary fibrosis (IPF) poses challenges to understanding its underlying cellular and molecular mechanisms and the development of better therapies. Previous studies suggest a pathophysiological role for neuraminidase 1 (NEU1), an enzyme that removes terminal sialic acid from glycoproteins. We observed increased NEU1 expression in epithelial and endothelial cells, as well as fibroblasts, in the lungs of patients with IPF compared with healthy control lungs. Recombinant adenovirus-mediated gene delivery of NEU1 to cultured primary human cells elicited profound changes in cellular phenotypes. Small airway epithelial cell migration was impaired in wounding assays, whereas, in pulmonary microvascular endothelial cells, NEU1 overexpression strongly impacted global gene expression, increased T cell adhesion to endothelial monolayers, and disrupted endothelial capillary-like tube formation. NEU1 overexpression in fibroblasts provoked increased levels of collagen types I and III, substantial changes in global gene expression, and accelerated degradation of matrix metalloproteinase-14. Intratracheal instillation of NEU1 encoding, but not control adenovirus, induced lymphocyte accumulation in bronchoalveolar lavage samples and lung tissues and elevations of pulmonary transforming growth factor-ß and collagen. The lymphocytes were predominantly T cells, with CD8(+) cells exceeding CD4(+) cells by nearly twofold. These combined data indicate that elevated NEU1 expression alters functional activities of distinct lung cell types in vitro and recapitulates lymphocytic infiltration and collagen accumulation in vivo, consistent with mechanisms implicated in lung fibrosis.


Asunto(s)
Fibrosis Pulmonar Idiopática/enzimología , Pulmón/enzimología , Linfocitosis/enzimología , Neuraminidasa/metabolismo , Células A549 , Animales , Movimiento Celular , Células Endoteliales/enzimología , Endotelio Vascular/patología , Femenino , Colágenos Fibrilares/metabolismo , Fibroblastos/enzimología , Expresión Génica , Células HEK293 , Humanos , Fibrosis Pulmonar Idiopática/inmunología , Fibrosis Pulmonar Idiopática/patología , Pulmón/irrigación sanguínea , Pulmón/patología , Linfocitos/inmunología , Ratones Endogámicos C57BL , Microvasos/patología , Neuraminidasa/genética
3.
J Immunol ; 189(1): 403-10, 2012 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-22634619

RESUMEN

Expression of IL-33 is elevated in patients with pulmonary diseases, and full-length (not proteolytically processed) IL-33 is the predominant form in the lungs in health and disease. To determine whether activation of IL-33 is needed for functional effects, activities of full-length mouse and mature mouse (mm) forms of IL-33 were compared in vivo. Replication-deficient adenoviral constructs were used for gene delivery. Both isoforms caused pulmonary infiltration of lymphocytes and neutrophils, whereas mm IL-33 also caused pulmonary eosinophilia and goblet cell hyperplasia and increased expression of IL-4, IL-5, IL-13, IL-17, MCP-1, and KC. The different effects were not associated with differential release from IL-33-producing cells or by differences in subcellular distributions of IL-33 isoforms. Germline deficiency of the cell surface receptor chain ST2 abrogated the mm IL-33-induced Th2-associated effects (pulmonary eosinophilia, goblet cell hyperplasia, and increased IL-4 and IL-5), yet the lymphocytic infiltration induced by full-length mouse IL-33 or mm IL-33 was not fully abrogated by the absence of ST2. The similar effects of IL-33 isoforms were associated with comparable regulation of gene expression, notably matrix metalloproteinases 3, 10, and 13. Thus, full-length IL-33 is functionally active in vivo in an ST2-independent fashion, and its effects are partially different from those of mature IL-33. The different effects of these isoforms, particularly the pro-Th2 effects of mature IL-33, are due to differential utilization of the IL-33R chain ST2, whereas their similar effects result from regulation of gene expression.


Asunto(s)
Mediadores de Inflamación/efectos adversos , Interleucinas/efectos adversos , Receptores de Superficie Celular/fisiología , Receptores de Interleucina/fisiología , Células Th2/inmunología , Células Th2/patología , Animales , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Femenino , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/inmunología , Células HEK293 , Humanos , Mediadores de Inflamación/administración & dosificación , Mediadores de Inflamación/fisiología , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Interleucinas/biosíntesis , Interleucinas/fisiología , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Biosíntesis de Proteínas/inmunología , Fibrosis Pulmonar/inmunología , Fibrosis Pulmonar/metabolismo , Fibrosis Pulmonar/patología , Receptores de Superficie Celular/biosíntesis , Receptores de Superficie Celular/genética , Receptores de Interleucina/deficiencia , Receptores de Interleucina/genética , Células Madre/inmunología , Células Madre/metabolismo , Células Madre/patología , Células Th2/metabolismo
4.
J Pain Symptom Manage ; 68(1): e36-e45, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38599533

RESUMEN

CONTEXT: Opioid therapy is a cornerstone for treatment of cancer-related pain, but standardized management practices for patients with cancer and aberrant urine drug test (UDT) results are lacking. OBJECTIVES: To identify the prevalence of UDT ordering (both screening and definitive testing) in the oncology setting and to examine clinician management practices for patients with cancer on opioid therapy with aberrant definitive UDT results. METHODS: We conducted a retrospective chart review of patients with cancer on opioid therapy at an academic cancer center in the United States. Outcomes included UDT ordering patterns and clinician management practices in response to aberrant definitive UDT results. RESULTS: Our study revealed an overall UDT ordering rate of 3.7% among 10,371 patients with cancer on opioid therapy. Among 143 patients for whom definitive UDTs were ordered, oncologists only ordered 14 (9.8%) UDTs, while palliative care ordered the majority (n = 129; 90.2%). Fifty-five (38.5%) patients had aberrant results, and the most common aberrancy was presence of illicit drugs 22 [15.4%]. Clinicians rarely made medication changes (20 [36.4%]) when UDT results were aberrant, and in the setting of possible fentanyl use (n = 8), only 3 (37.5%) patients were started/switched to methadone, and none were started/switched to buprenorphine. CONCLUSION: Overall UDT ordering was infrequent for patients with cancer on opioid therapy, especially by oncologists, and clinicians rarely made prescribing changes when definitive UDT results were aberrant. More definitive guidance related to UDT ordering and opioid management are needed for patients with cancer and aberrant UDT results.


Asunto(s)
Analgésicos Opioides , Dolor en Cáncer , Pautas de la Práctica en Medicina , Humanos , Masculino , Estudios Retrospectivos , Femenino , Persona de Mediana Edad , Analgésicos Opioides/uso terapéutico , Analgésicos Opioides/orina , Dolor en Cáncer/tratamiento farmacológico , Anciano , Detección de Abuso de Sustancias , Cuidados Paliativos , Adulto , Instituciones Oncológicas , Neoplasias/complicaciones , Neoplasias/orina
5.
J Appl Lab Med ; 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39076019

RESUMEN

BACKGROUND: The COVID-19 pandemic reportedly had a significant impact on drug and alcohol use. In this article, we determine positivity rates for urine drugs of abuse and blood alcohol in 5 emergency departments (ED) in the greater Boston metropolitan area over a 4-year period (pre-, during, and post-COVID-19 pandemic). METHODS: Positivity rates for the urine drug screening (UDS) panel and blood alcohol concentration (>80 mg/dL; over the legal limit in MA) were calculated in patients presenting to one of the 5 ED (2 academic hospitals in Boston, MA and 3 community hospitals outside Boston, MA) during each of the 4 different time periods: pre-COVID (January 1, 2019 to December 31, 2019), stay-at-home (March 24, 2020 to May 18, 2020), during COVID (May 19, 2020 to March 28, 2021), and post-COVID (May 12, 2023 to August 31, 2023). Trend analysis was performed. Additionally, positivity rates during and post-COVID were compared to pre-COVID to determine any significant changes in drug positivity. RESULTS: Stimulant (amphetamines and cocaine), cannabinoid, and methadone positivity increased during the pandemic and cocaine, cannabinoid, and methadone positivity remains elevated. By contrast, benzodiazepine and opioid (opiates, fentanyl, oxycodone) positivity decreased and remains lower post-COVID compared to pre-COVID. Patients in the ED with blood alcohol over the legal limit decreased both during and post-COVID. CONCLUSION: Our study showed that the COVID-19 pandemic significantly affected drug and alcohol positivity rates in patients presenting to the ED in greater Boston area. We encourage other institutions to perform similar analyses to help determine local drug use patterns and appropriate composition of UDS panels.

6.
J Appl Lab Med ; 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38656327

RESUMEN

BACKGROUND: Many fentanyl immunoassays are limited in their ability to detect norfentanyl. Urine specimens collected from individuals who have been exposed to fentanyl frequently have detectable concentrations of norfentanyl (≥2 ng/mL) but low concentrations of fentanyl (<2 ng/mL) by LC-MS/MS. The Lin-Zhi Fentanyl II Immunoassay (Lin-Zhi) claims 100% cross-reactivity with norfentanyl and therefore may detect exposure missed by other assays. METHODS: In addition to verifying the manufacturer's analytical sensitivity claims, we selected 92 urine specimens with low-positive Lin-Zhi results (1-99 absorbance units, lowest 10%) for analysis by the Immunalysis Health Equity Impact Assessment and ARK II fentanyl methods. The accuracy of the 3 immunoassays was compared to LC-MS/MS as the reference method. RESULTS: Spiking studies using purified fentanyl and norfentanyl and a set of 100 consecutive specimens confirmed the manufacturer's claims of limit of detection for fentanyl (3.8 ng/mL) and norfentanyl (5.0 ng/mL). However, the 92 low-positive patient specimens demonstrated concentrations of norfentanyl and fentanyl below 2.0 ng/mL by LC-MS/MS, with 47 (51%) having only norfentanyl detected. When comparing Lin-Zhi to the Immunalysis and ARK II immunoassays, only 27 (29%) of the 92 specimens were concordant. Fifty-two (57%) of the specimens were positive by LC-MS/MS and Lin-Zhi but false negative by one or both other immunoassays. Seven specimens (8%) were positive by Lin-Zhi but negative by the other immunoassays and had undetectable concentrations (<2 ng/mL) of fentanyl and norfentanyl by LC-MS/MS. CONCLUSIONS: The clinical sensitivity of the Lin-Zhi exceeds the manufacturer's claims, providing results comparable to LC-MS/MS methods.

7.
J Mass Spectrom Adv Clin Lab ; 33: 14-20, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39041051

RESUMEN

Introduction: Benzodiazepines are frequently prescribed and misused therefore urine drug screening (UDS) is performed in many patient populations. Most current benzodiazepine immunoassays have poor sensitivity, particularly for detecting the metabolites of newer benzodiazepines such as lorazepam in urine. Objectives: We aimed to verify the clinical performance of the new qualitative Roche Benzodiazepines II (BNZ2) immunoassay, as well as compare its performance to the Roche Benzodiazepines Plus (BENZ) assay in two patient populations: UDS in the emergency department (ED) and compliance monitoring. Methods: An initial verification study was performed, selecting for samples containing clonazepam and lorazepam metabolites. Performance of the BNZ2 and BENZ assays was compared to liquid chromatography-tandem mass spectrometry (LC-MS/MS) as the reference method. Sensitivity, specificity, false positive rate (FPR) and false negative rate (FNR) were determined. Results: We verified the performance claims in the initial verification and demonstrated similar precision, with coefficient of variations (CVs) of 12.8% and 7.7% for negative and positive controls, respectively. Furthermore, we observed higher clinical sensitivity and lower FNR with the BNZ2 assay in both the ED and compliance monitoring populations due to improved cross-reactivity for lorazepam and clonazepam metabolites. Despite these improvements, the BNZ2 assay was unable to detect 27% of specimens positive by LC-MS/MS, including specimens from patients using benzodiazepines without prescription. Discussion: Due to its improved performance and rapid turnaround time, the BNZ2 assay should be implemented for UDS in the ED. However, the assay should not replace LC-MS/MS testing for compliance monitoring, as unsuspected benzodiazepine use may go undetected.

8.
Am J Respir Cell Mol Biol ; 49(6): 999-1008, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23837438

RESUMEN

The mechanisms of interstitial lung disease (ILD) remain incompletely understood, although recent observations have suggested an important contribution by IL-33. Substantial elevations in IL-33 expression were found in the lungs of patients with idiopathic pulmonary fibrosis and scleroderma lung disease, as well as in the bleomycin injury mouse model. Most of the observed IL-33 expression was intracellular and intranuclear, suggesting involvement of the full-length (fl) protein, but not of the proteolytically processed mature IL-33 cytokine. The effects of flIL-33 on mouse lungs were assessed independently and in combination with bleomycin injury, using recombinant adenovirus-mediated gene delivery. Bleomycin-induced changes were not affected by gene deficiency of the IL-33 receptor T1/ST2. Combined flIL-33 expression and bleomycin injury exerted a synergistic effect on pulmonary lymphocyte and collagen accumulation, which could be explained by synergistic regulation of the cytokines transforming growth factor-ß, IL-6, monocyte chemotactic protein-1, macrophage inflammatory protein\x{2013}1α, and tumor necrosis factor-α. By contrast, no increase in the levels of the Th2 cytokines IL-4, IL-5, or IL-13 was evident. Moreover, flIL-33 was found to increase the expression of several heat shock proteins (HSPs) significantly, and in particular HSP70, which is known to be associated with ILD. Thus, flIL-33 is a synergistic proinflammatory and profibrotic regulator that acts by stimulating the expression of several non-Th2 cytokines, and activates the expression of HSP70.


Asunto(s)
Bleomicina/toxicidad , Interleucinas/inmunología , Lesión Pulmonar/etiología , Animales , Citocinas/inmunología , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Humanos , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33 , Interleucinas/genética , Interleucinas/metabolismo , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Enfermedades Pulmonares Intersticiales/etiología , Enfermedades Pulmonares Intersticiales/inmunología , Enfermedades Pulmonares Intersticiales/patología , Lesión Pulmonar/inmunología , Lesión Pulmonar/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Procesamiento Proteico-Postraduccional , Receptores de Interleucina/deficiencia , Receptores de Interleucina/genética , Receptores de Interleucina/inmunología
10.
J Appl Lab Med ; 8(6): 1160-1172, 2023 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-37643134

RESUMEN

BACKGROUND: Clinical laboratories immediately provided rapid, reliable, and high-throughout diagnostic testing for COVID-19, which was an essential component in combating the pandemic. As the pandemic evolved, the clinical laboratory was faced with additional challenges. However, there are limited studies on the impact of the pandemic on the clinical laboratory over the past 3 years. METHODS: The American Association for Clinical Chemistry (AACC) sent 8 surveys over a 32-month time period to international clinical laboratory leadership asking questions about COVID-19 testing, supplies, staffing, and lessons learned. RESULTS: There were a total of 191 unique respondents: 133 laboratories in the US and 58 laboratories from 37 other countries participated. By May 2020, more than 70% of laboratories offered COVID-19 diagnostic testing with average turnaround times ranging from 1 to 24 h. Daily COVID-19 testing volumes peaked in January of 2022 at a median of 775 tests per day. Throughout the pandemic, supplies and staffing concerns increased. In most of the 8 surveys, 55% to 65% of laboratories reported they were unable to obtain supplies. Obtaining reagents and test kits was the most problematic. Staffing challenges continue to be a significant concern and most laboratories have struggled hiring testing personnel. CONCLUSIONS: Survey results were utilized to demonstrate the impact of the pandemic on the clinical laboratory community, and importantly, findings were presented to the White House Coronavirus Taskforce. Overall, the clinical laboratories had a robust response to the COVID-19 pandemic, and despite ongoing and evolving challenges, continue to provide rapid diagnostic testing.


Asunto(s)
COVID-19 , Humanos , Estados Unidos , Prueba de COVID-19 , Laboratorios Clínicos , Pandemias , Técnicas de Laboratorio Clínico/métodos , SARS-CoV-2
11.
Clin Toxicol (Phila) ; 61(4): 248-259, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37129223

RESUMEN

BACKGROUND: Many states in the United States have progressed towards legalization of marijuana including decriminalization, medicinal and/or recreational use. We studied the impact of legalization on cannabis-related emergency department visits in states with varying degrees of legalization. METHODS: Seventeen healthcare institutions in fifteen states (California, Colorado, Connecticut, Florida, Iowa, Kentucky, Maryland, Massachusetts, Missouri, New Hampshire, Oregon, South Carolina, Tennessee, Texas, Washington) participated. Cannabinoid immunoassay results and cannabis-related International Classification of Diseases (ninth and tenth versions) codes were obtained for emergency department visits over a 3- to 8-year period during various stages of legalization: no state laws, decriminalized, medical approval before dispensaries, medical dispensaries available, recreational approval before dispensaries and recreational dispensaries available. Trends and monthly rates of cannabinoid immunoassay and cannabis-related International Classification of Diseases code positivity were determined during these legalization periods. RESULTS: For most states, there was a significant increase in both cannabinoid immunoassay and International Classification of Diseases code positivity as legalization progressed; however, positivity rates differed. The availability of dispensaries may impact positivity in states with medical and/or recreational approval. In most states with no laws, there was a significant but smaller increase in cannabinoid immunoassay positivity rates. CONCLUSIONS: States may experience an increase in cannabis-related emergency department visits with progression toward marijuana legalization. The differences between states, including those in which no impact was seen, are likely multifactorial and include cultural norms, attitudes of local law enforcement, differing patient populations, legalization in surrounding states, availability of dispensaries, various ordering protocols in the emergency department, and the prevalence of non-regulated cannabis products.


Asunto(s)
Cannabinoides , Cannabis , Marihuana Medicinal , Estados Unidos , Humanos , Colorado/epidemiología , Legislación de Medicamentos , Servicio de Urgencia en Hospital
12.
Cytokine ; 58(1): 20-6, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22249152

RESUMEN

We have previously described an alternatively spliced isoform of IL-4 mRNA that omits exon 2 and is termed IL-4δ2. However, the natural production of IL-4δ2 protein and its association with disease have not been previously assessed due to unavailability of an antibody that interacts with IL-4δ2 without cross-reactivity with full length IL-4. We used a unique monoclonal antibody (mAb) that reacts with IL-4δ2, but not with IL-4, and observed that IL-4δ2 is naturally produced by T cells from patients with asthma, but not from healthy controls. The kinetics of IL-4δ2 and IL-4 production by phorbol myristate acetate (PMA)/ionomycin-activated cells differed, with IL-4δ2 increasing at 48-72h and IL-4 peaking at 24h. The steady-state levels of IL-4δ2 mRNA varied significantly among the donors and were discordant with the corresponding protein levels, suggesting post-transcriptional regulation of protein production. Polarized Th1 or Th2 lymphocytes were not a major source of IL-4δ2. Stimulation of cultured T lymphocytes with IL-4δ2 caused elevated production of IFN-γ, IL-10, IL-6, MCP-1, and TNF-α, with notable differences between patients and controls in the production of IFN-γ, IL-10, and IL-6. Thus, IL-4δ2 is natively produced not only as mRNA but also as a protein by cells other than Th1 or Th2. It is regulated post-transcriptionally, is associated with allergic asthma, and regulates production of other cytokines by primary T lymphocytes. Alternatively spliced interleukin-4 may be a new biomarker, a pathophysiological player, and possibly a molecular target for future therapies in asthma.


Asunto(s)
Empalme Alternativo , Asma/genética , Asma/fisiopatología , Interleucina-4/genética , Linfocitos T/metabolismo , Adulto , Humanos , Interleucina-4/biosíntesis , ARN Mensajero/metabolismo
13.
J Perinatol ; 41(1): 157-163, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33070153

RESUMEN

OBJECTIVES: Investigate characteristics of term infants culture-evaluated for early-onset sepsis (EOS) in neonatal intensive care units (NICUs), frequencies of organisms causing EOS, and factors associated with EOS. STUDY DESIGN: Using a cohort design, we identified term infants evaluated for EOS with blood, cerebrospinal fluid, or urine cultures in 326 NICUs (2011-2016). Using multivariable logistic regression, we investigated the association between EOS and demographic characteristics. RESULTS: Of 142,410 infants, 1197 (0.8%) had EOS, most commonly caused by group B Streptococcus (GBS; 40.6%). Lower EOS risk was associated with low Apgar score, Cesarean delivery, small for gestational age, prenatal antibiotic exposure, and positive or unknown maternal GBS screening result. Increased risk was associated with prolonged rupture of membranes, maternal age <19 years, vasopressor treatment, and ventilator support. CONCLUSION(S): GBS was the most frequent cause of EOS. Early risk factor recognition may help daily management of term infants in NICUs.


Asunto(s)
Unidades de Cuidado Intensivo Neonatal , Sepsis , Adulto , Antibacterianos/uso terapéutico , Cesárea , Femenino , Humanos , Lactante , Recién Nacido , Embarazo , Factores de Riesgo , Sepsis/diagnóstico , Sepsis/tratamiento farmacológico , Sepsis/epidemiología , Streptococcus agalactiae , Adulto Joven
14.
Mol Biol Cell ; 31(5): 386-396, 2020 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-31940260

RESUMEN

Mechanical cues regulate the function of a broad range of stem cells in culture and in tissue. For example, soft substrates promote the neuronal differentiation of neural stem cells (NSCs) by suppressing cytoskeletal contractility. However, the mechanisms that link cytoskeletal signaling to the transcriptional regulatory processes that ultimately govern stiffness-dependent NSC fate commitment are not fully understood. Here, we show that Angiomotin (AMOT), which can bind both F-actin and the neurosuppressive transcriptional coactivator Yes-associated protein (YAP), is critical for mechanotransduction in NSCs. On soft substrates, loss of AMOT substantially reduces neurogenesis, whereas on stiff substrates, loss of AMOT negates the rescue of neurogenesis normally induced by pharmacologic inhibition of myosin activity. Furthermore, overexpression of a phospho-mimetic S175E AMOT mutant, which has been established to enhance AMOT-YAP binding, increases ß-catenin activity and rescues neurogenesis on stiff substrates. Together, our data identify AMOT as an important intermediate signal transducer that allows NSCs to sense and respond to extracellular stiffness cues.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Diferenciación Celular , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Mecanotransducción Celular , Proteínas de la Membrana/metabolismo , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Quinasas Asociadas a rho/metabolismo , Actinas/metabolismo , Angiomotinas , Animales , Femenino , Modelos Biológicos , Neurogénesis , Fosforilación , Unión Proteica , Ratas Endogámicas F344 , Fracciones Subcelulares/metabolismo , Especificidad por Sustrato , Proteínas Señalizadoras YAP , beta Catenina/metabolismo , Proteínas de Unión al GTP rho/metabolismo
15.
Curr Opin Biomed Eng ; 4: 13-20, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29399646

RESUMEN

Neural stem cells (NSCs) are a valuable cell source for tissue engineering, regenerative medicine, disease modeling, and drug screening applications. Analogous to other stem cells, NSCs are tightly regulated by their microenvironmental niche, and prior work utilizing NSCs as a model system with engineered biomaterials has offered valuable insights into how biophysical inputs can regulate stem cell proliferation, differentiation, and maturation. In this review, we highlight recent exciting studies with innovative material platforms that enable narrow stiffness gradients, mechanical stretching, temporal stiffness switching, and three-dimensional culture to study NSCs. These studies have significantly advanced our knowledge of how stem cells respond to an array of different biophysical inputs and the underlying mechanosensitive mechanisms. In addition, we discuss efforts to utilize engineered material scaffolds to improve NSC-based translational efforts and the importance of mechanobiology in tissue engineering applications.

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