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1.
Pediatr Res ; 2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38388819

ABSTRACT

BACKGROUND: Overuse of sedation and anesthesia causes delays in gastrojejunostomy tube (GJ) exchanges, increased risk of complications, unnecessary use of resources, preventable hospital admissions, and an adverse impact on patient and family experience. Our hospital was over-utilizing sedation and anesthesia, and we aimed to decrease this use from 78% to 20% within two years. METHODS: An interdisciplinary quality improvement team comprehensively evaluated current processes for GJ tube exchanges through a retrospective chart review for baseline data with prospective time series analysis after improvement implementation. The primary outcome measure was the percentage of pediatric patients that utilized sedation or anesthesia for routine GJ tube exchanges. RESULTS: A statistical process control p-chart was used to calculate and show changes over time for patients (n = 45 patients average). The median percent of pediatric GJ tube exchanges performed with sedation or anesthesia decreased from 77.8% to 11.3%. Most patients (76%) were covered by Medicaid programs; with low reimbursement rates, decreased anesthesiologist billing revenue does not have a negative financial impact. CONCLUSIONS: An interprofessional improvement initiative that engaged patients and families, incorporated pediatric-specific staff services, and developed systematic weaning was associated with a significant decrease in the overuse of sedation and anesthesia for GJ tube exchanges. IMPACT: We believe that this work is highly relevant and impactful for medical centers caring for children who require gastrojejunostomy tubes, an increasingly common approach to management of children with feeding issues. There is very little literature available on the use of sedation or anesthesia for changing these tubes. While large children's medical centers in the USA usually do not utilize sedation or anesthesia, there are likely many serious outliers, especially when children receive care outside of a pediatric specific institution. This paper brings awareness to this serious issue and provides information about how we changed care to achieve higher patient safety and lower medical costs.

2.
Am J Physiol Cell Physiol ; 324(5): C1101-C1109, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36971422

ABSTRACT

MicroRNAs (miRs) control stem cell biology and fate. Ubiquitously expressed and conserved miR-16 was the first miR implicated in tumorigenesis. miR-16 is low in muscle during developmental hypertrophy and regeneration. It is enriched in proliferating myogenic progenitor cells but is repressed during differentiation. The induction of miR-16 blocks myoblast differentiation and myotube formation, whereas knockdown enhances these processes. Despite a central role for miR-16 in myogenic cell biology, how it mediates its potent effects is incompletely defined. In this investigation, global transcriptomic and proteomic analyses after miR-16 knockdown in proliferating C2C12 myoblasts revealed how miR-16 influences myogenic cell fate. Eighteen hours after miR-16 inhibition, ribosomal protein gene expression levels were higher relative to control myoblasts and p53 pathway-related gene abundance was lower. At the protein level at this same time point, miR-16 knockdown globally upregulated tricarboxylic acid (TCA) cycle proteins while downregulating RNA metabolism-related proteins. miR-16 inhibition induced specific proteins associated with myogenic differentiation such as ACTA2, EEF1A2, and OPA1. We extend prior work in hypertrophic muscle tissue and show that miR-16 is lower in mechanically overloaded muscle in vivo. Our data collectively point to how miR-16 is implicated in aspects of myogenic cell differentiation. A deeper understanding of the role of miR-16 in myogenic cells has consequences for muscle developmental growth, exercise-induced hypertrophy, and regenerative repair after injury, all of which involve myogenic progenitors.


Subject(s)
MicroRNAs , Cell Differentiation/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , Muscle Development/genetics , Muscle Fibers, Skeletal/metabolism , Proteome/genetics , Proteomics , Transcriptome/genetics , Animals , Mice
3.
Cell Biochem Funct ; 41(4): 478-489, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37150891

ABSTRACT

Cachexia is characterized by losses in lean body mass and its progression results in worsened quality of life and exacerbated outcomes in cancer patients. However, the role and impact of fibrosis during the early stages and development of cachexia in under-investigated. The purpose of this study was to determine if fibrosis occurs during cachexia development, and to evaluate this in both sexes. Female and male C57BL6/J mice were injected with phosphate-buffered saline or Lewis Lung Carcinoma (LLC) at 8-week of age, and tumors were allowed to develop for 1, 2, 3, or 4 weeks. 3wk and 4wk female tumor-bearing mice displayed a dichotomy in tumor growth and were reassigned to high tumor (HT) and low tumor (LT) groups. In vitro analyses were also performed on cocultured C2C12 and 3T3 cells exposed to LLC conditioned media. Immunohistochemistry and quantitative polymerase chain reaction (qPCR) analysis were used to investigate fibrosis and fibrosis-related signaling in skeletal muscle. Collagen deposition in skeletal muscle was increased in the 1wk, LT, and HT groups in female mice. However, collagen deposition was only increased in the 4wk group in male mice. In general, female mice displayed earlier alterations in extracellular matrix (ECM)-related genes beginning at 1wk post-LLC injection. Whereas this was not seen in males. While overall tumor burden is tightly correlated to cachexia development in both sexes, fibrotic development is not. Male mice did not exhibit early-stage alterations in ECM-related genes contrary to what was noted in female mice.


Subject(s)
Cachexia , Carcinoma, Lewis Lung , Male , Female , Animals , Mice , Cachexia/etiology , Cachexia/pathology , Quality of Life , Muscle, Skeletal/pathology , Carcinoma, Lewis Lung/complications , Carcinoma, Lewis Lung/pathology , Mice, Inbred C57BL
4.
Am J Physiol Endocrinol Metab ; 322(3): E278-E292, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35068192

ABSTRACT

microRNAs (miRs) are linked to various human diseases including type 2 diabetes mellitus (T2DM) and emerging evidence suggests that miRs may serve as potential therapeutic targets. Lower miR-16 content is consistent across different models of T2DM; however, the role of miR-16 in muscle metabolic health is still elusive. Therefore, the purpose of this study was to investigate how deletion of miR-16 in mice affects skeletal muscle metabolic health and contractile function in both sexes. This study was conducted using both 1) in vitro and 2) in vivo experiments. In in vitro experiments, we used C2C12 myoblasts to test if inhibition or overexpression of miR-16 affected insulin-mediated glucose handling. In in vivo experiments, we generated muscle-specific miR-16 knockout (KO) mice fed a high-fat diet (HFD) to assess how miR-16 content impacts metabolic and contractile properties including glucose tolerance, insulin sensitivity, muscle contractile function, protein anabolism, and mitochondrial network health. In in vitro experiments, although inhibition of miR-16 induced impaired insulin signaling (P = 0.002) and glucose uptake (P = 0.014), overexpression of miR-16 did not attenuate lipid overload-induced insulin resistance using the diacylglycerol analog 1-oleoyl-2-acetyl-sn-glycerol. In in vivo experiments, miR-16 deletion induced both impaired muscle contractility (P = 0.031-0.033), and mitochondrial network health (P = 0.008-0.018) in both sexes. However, although males specifically exhibited impaired insulin sensitivity following miR-16 deletion (P = 0.030), female KO mice showed pronounced glucose intolerance (P = 0.046), corresponding with lower muscle weights (P = 0.015), and protein hyperanabolism (P = 0.023). Our findings suggest distinct sex differences in muscle adaptation in response to miR-16 deletion and miR-16 may serve as a key regulator for metabolic dysregulation in T2DM.NEW & NOTEWORTHY We set to investigate the role of miR-16 in skeletal muscle during diet-induced insulin resistance. Our data provide novel evidence that the lack of miR-16 induced multiple aberrations in insulin sensitivity, muscle contractility, mitochondrial network health, and protein turnover in a sex-dependent manner. Interestingly, miR-16 deletion leads to insulin resistance in males and exacerbated glucose intolerance in females, suggesting different mechanisms of metabolic dysregulation with a lack of miR-16 between sexes.


Subject(s)
Diabetes Mellitus, Type 2 , Glucose Intolerance , Insulin Resistance , MicroRNAs , Animals , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Diet, High-Fat , Female , Glucose/metabolism , Glucose Intolerance/genetics , Glucose Intolerance/metabolism , Insulin/metabolism , Insulin Resistance/genetics , Male , Mice , Mice, Knockout , MicroRNAs/genetics , MicroRNAs/metabolism , Muscle, Skeletal/metabolism
5.
Int J Mol Sci ; 21(21)2020 Oct 22.
Article in English | MEDLINE | ID: mdl-33105841

ABSTRACT

It is established that cancer cachexia causes limb muscle atrophy and is strongly associated with morbidity and mortality; less is known about how the development of cachexia impacts the diaphragm. The purpose of this study was to investigate cellular signaling mechanisms related to mitochondrial function, reactive oxygen species (ROS) production, and protein synthesis during the development of cancer cachexia. C57BL/J6 mice developed Lewis Lung Carcinoma for either 0 weeks (Control), 1 week, 2 weeks, 3 weeks, or 4 weeks. At designated time points, diaphragms were harvested and analyzed. Mitochondrial respiratory control ratio was ~50% lower in experimental groups, which was significant by 2 weeks of cancer development, with no difference in mitochondrial content markers COXIV or VDAC. Compared to the controls, ROS was 4-fold elevated in 2-week animals but then was not different at later time points. Only one antioxidant protein, GPX3, was altered by cancer development (~70% lower in experimental groups). Protein synthesis, measured by a fractional synthesis rate, appeared to become progressively lower with the cancer duration, but the mean difference was not significant. The development and progression of cancer cachexia induces marked alterations to mitochondrial function and ROS production in the diaphragm and may contribute to increased cachexia-associated morbidity and mortality.


Subject(s)
Cachexia/metabolism , Carcinoma, Lewis Lung/metabolism , Diaphragm/physiopathology , Mitochondria, Muscle/metabolism , Animals , Antioxidants/metabolism , Cachexia/etiology , Carcinoma, Lewis Lung/physiopathology , Diaphragm/metabolism , Forkhead Box Protein O3/metabolism , Glutathione Peroxidase/metabolism , Male , Mice, Inbred C57BL , Muscle Proteins/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction
6.
Proc Natl Acad Sci U S A ; 113(45): 12768-12773, 2016 Nov 08.
Article in English | MEDLINE | ID: mdl-27791120

ABSTRACT

Hepatitis C virus (HCV) is a major cause of liver disease, affecting over 2% of the world's population. The HCV envelope glycoproteins E1 and E2 mediate viral entry, with E2 being the main target of neutralizing antibody responses. Structural investigations of E2 have produced templates for vaccine design, including the conserved CD81 receptor-binding site (CD81bs) that is a key target of broadly neutralizing antibodies (bNAbs). Unfortunately, immunization with recombinant E2 and E1E2 rarely elicits sufficient levels of bNAbs for protection. To understand the challenges for eliciting bNAb responses against the CD81bs, we investigated the E2 CD81bs by electron microscopy (EM), hydrogen-deuterium exchange (HDX), molecular dynamics (MD), and calorimetry. By EM, we observed that HCV1, a bNAb recognizing the N-terminal region of the CD81bs, bound a soluble E2 core construct from multiple angles of approach, suggesting components of the CD81bs are flexible. HDX of multiple E2 constructs consistently indicated the entire CD81bs was flexible relative to the rest of the E2 protein, which was further confirmed by MD simulations. However, E2 has a high melting temperature of 84.8 °C, which is more akin to proteins from thermophilic organisms. Thus, recombinant E2 is a highly stable protein overall, but with an exceptionally flexible CD81bs. Such flexibility may promote induction of nonneutralizing antibodies over bNAbs to E2 CD81bs, underscoring the necessity of rigidifying this antigenic region as a target for rational vaccine design.

7.
Physiol Genomics ; 50(12): 1071-1082, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30289747

ABSTRACT

Cancer-cachexia (CC) is a wasting condition directly responsible for 20-40% of cancer-related deaths. The mechanisms controlling development of CC-induced muscle wasting are not fully elucidated. Most investigations focus on the postcachectic state and do not examine progression of the condition. We recently demonstrated mitochondrial degenerations precede muscle wasting in time course progression of CC. However, the extent of muscle perturbations before wasting in CC is unknown. Therefore, we performed global gene expression analysis in CC-induced muscle wasting to enhance understanding of intramuscular perturbations across the development of CC. Lewis lung carcinoma (LLC) was injected into the hind-flank of C57BL6/J mice at 8 wk of age with tumor allowed to develop for 1, 2, 3, or 4 wk and compared with PBS-injected control. Muscle wasting was evident at 4 wk LLC. RNA sequencing of gastrocnemius muscle samples showed widespread alterations in LLC compared with PBS animals with largest differences seen in 4 wk LLC, suggesting extensive transcriptomic alterations concurrent to muscle wasting. Commonly altered pathways included: mitochondrial dysfunction and protein ubiquitination, along with other less studied processes in this condition regulating transcription/translation and cytoskeletal structure. Current findings present novel evidence of transcriptomic shifts and altered cellular pathways in CC-induced muscle wasting.


Subject(s)
Cachexia/genetics , Muscle Fibers, Skeletal/pathology , Muscular Atrophy/genetics , Transcriptome/genetics , Animals , Cachexia/pathology , Carcinoma, Lewis Lung/genetics , Carcinoma, Lewis Lung/pathology , Disease Progression , Gene Expression Profiling/methods , Mice , Mice, Inbred C57BL , Mitochondria/genetics , Mitochondria/pathology , Muscular Atrophy/pathology
8.
Physiol Genomics ; 49(5): 253-260, 2017 May 01.
Article in English | MEDLINE | ID: mdl-28341621

ABSTRACT

Muscle atrophy is a hallmark of cancer cachexia resulting in impaired function and quality of life and cachexia is the immediate cause of death for 20-40% of cancer patients. Multiple microRNAs (miRNAs) have been identified as being involved in muscle development and atrophy; however, less is known specifically on miRNAs in cancer cachexia. The purpose of this investigation was to examine the miRNA profile of skeletal muscle atrophy induced by cancer cachexia to uncover potential miRNAs involved with this catabolic condition. Phosphate-buffered saline (PBS) or Lewis lung carcinoma cells (LLC) were injected into C57BL/6J mice at 8 wk of age. LLC animals were allowed to develop tumors for 4 wk to induce cachexia. Tibialis anterior muscles were extracted and processed to isolate small RNAs, which were used for miRNA sequencing. Sequencing results were assembled with mature miRNAs, and functions of miRNAs were analyzed by Ingenuity Pathway Analysis. LLC animals developed tumors that contributed to significantly smaller tibialis anterior muscles (18.5%) and muscle cross-sectional area (40%) compared with PBS. We found 371 miRNAs to be present in the muscle above background levels. Of these, nine miRNAs were found to be differentially expressed. Significantly altered groups of miRNAs were categorized into primary functionalities including cancer, cell-to-cell signaling, and cellular development among others. Gene network analysis predicted specific alterations of factors contributing to muscle size including Akt, FOXO3, and others. These results create a foundation for future research into the sufficiency of targeting these genes to attenuate muscle loss in cancer cachexia.


Subject(s)
Cachexia/genetics , MicroRNAs/genetics , Muscle, Skeletal/pathology , Muscular Atrophy/genetics , Neoplasms, Experimental/genetics , Animals , Cachexia/complications , Cachexia/physiopathology , Gene Expression Regulation , Gene Regulatory Networks , Mice, Inbred C57BL , Muscular Atrophy/etiology , Muscular Atrophy/pathology , Neoplasms, Experimental/complications
9.
Exp Physiol ; 102(9): 1194-1207, 2017 09 01.
Article in English | MEDLINE | ID: mdl-28639297

ABSTRACT

NEW FINDINGS: What is the central question of this study? What are the individual and combined effects of muscle-specific peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) overexpression and physical activity during high-fat feeding on glucose and exercise tolerance? What is the main finding and its importance? Our main finding is that muscle-specific PGC-1α overexpression provides no protection against lipid-overload pathologies nor does it enhance exercise adaptations. Instead, physical activity, regardless of PGC-1α content, protects against high-fat diet-induced detriments. Activation of muscle autophagy was correlated with exercise protection, suggesting that autophagy might be a mediating factor for exercise-induced protection from lipid overload. The prevalence of glucose intolerance is alarmingly high. Efforts to promote mitochondrial biogenesis through peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) to mitigate glucose intolerance have been controversial. However, physical activity remains a primary means to alleviate the condition. The aim of this study was to determine the combined effects of muscle-specific overexpression of PGC-1α and physical activity on glucose handling during diet-induced obesity. Wild-type (WT, ∼20) and PGC-1α muscle transgenic (MCK-PGC-1α, ∼20) mice were given a Western diet (WD) at 8 weeks age and allowed to consume food ab libitum throughout the study. At 12 weeks of age, all animals were divided into sedentary (SED) or voluntary wheel running (VWR) interventions. At 7, 11 and 15 weeks of age, animals underwent glucose tolerance tests (GTT) and graded exercise tests (GXT). At 16 weeks of age, tissues were collected. At 11 weeks, the MCK-PGC-1α animals had 50% greater glucose tolerance integrated area under the curve compared with WT. However, at 15 weeks, SED animals also had greater GTT integrated area under the curve compared with VWR, regardless of genotype; furthermore, SED animals demonstrated reduced exercise capacity compared with earlier time points, which was not seen in VWR animals. Voluntary distance run per day was correlated with GTT in VWR-WT, but not VWR-MCK-PGC-1α mice. Voluntary wheel running and genotype independently resulted in a greater LC3II/LC3I ratio, suggesting enhanced autophagosome formation, which was correlated with exercise-induced improvements in GTT. In conclusion, artificially increasing mitochondrial content does not protect from lipid-induced pathologies nor does it augment exercise adaptations. Physical activity ameliorates the effects of lipid overload-induced glucose intolerance, an effect that appears to be related to enhanced activation of autophagy.


Subject(s)
Autophagy/physiology , Glucose/metabolism , Obesity/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Physical Conditioning, Animal/physiology , Animals , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Mitochondria/metabolism , Motor Activity/physiology , Muscle, Skeletal/metabolism
10.
J Cell Biochem ; 117(8): 1775-87, 2016 08.
Article in English | MEDLINE | ID: mdl-26683117

ABSTRACT

Insulin resistant diabetes, currently at epidemic levels in developed countries, begins in the skeletal muscle and is linked to altered protein turnover. microRNAs downregulate targeted mRNA translation decreasing the amount of translated protein, thereby regulating many cellular processes. Regulation of miRNAs and their function in skeletal muscle insulin resistance is largely unexplored. The purpose of this study was to identify the effects of insulin resistance on contents of skeletal muscle miRNAs with potential functions in protein turnover. We examined miRs -1, -16, -23, -27, -133a, -133b, and -206 in muscles of Zucker rats. miR-1 was 5- to 10-fold greater in obesity, whereas miRs-16 and -133b were repressed ∼50% in obese compared to lean rats, with no other alterations in miRNA contents. miR-16 correlated to protein synthesis in lean, but not obese rats. miR-16 reduction by lipid overload was verified in-vivo by diet-induced obesity and in-vitro using a diacylglycerol analog. A role for miR-16 in protein turnover of skeletal myocytes was established using transient overexpression and anti-miR inhibition. miR-16 overexpression resulted in lower protein synthesis (puromycin incorporation, ∼25-50%), mTOR (∼25%), and p70S6K1 (∼40%) in starved and insulin stimulated myoblasts. Conversely, anti-miR-16 increased basal protein synthesis (puromycin incorporation, ∼75%), mTOR (∼100%), and p70S6K1 (∼100%). Autophagy was enhanced by miR-16 overexpression (∼50% less BCL-2, ∼100% greater LC3II/I, ∼50% less p62) and impaired with miR-16 inhibition (∼45% greater BCL-2, ∼25% less total LC3, ∼50% greater p62). This study demonstrates reduced miR-16 during insulin resistance and establishes miR-16 control of protein accretion in skeletal muscle. J. Cell. Biochem. 117: 1775-1787, 2016. © 2015 Wiley Periodicals, Inc.


Subject(s)
Autophagy , Insulin Resistance , MicroRNAs/metabolism , Muscle Proteins/metabolism , Myoblasts, Skeletal/metabolism , Obesity/metabolism , Animals , MicroRNAs/genetics , Muscle Proteins/genetics , Obesity/genetics , Rats , Rats, Zucker
11.
J Virol ; 88(1): 469-76, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24155406

ABSTRACT

Previous human antibody studies have shown that the human VH1-46 antibody variable gene segment encodes much of the naturally occurring human B cell response to rotavirus and is directed to virus protein 6 (VP6). It is currently unknown why some of the VH1-46-encoded human VP6 monoclonal antibodies inhibit viral transcription while others do not. In part, there are affinity differences between antibodies that likely affect inhibitory activity, but we also hypothesize that there are differing modes of binding to VP6 that affect the ability to block the transcriptional pore on double-layered particles. Here, we used a hybrid method approach for antibody epitope mapping, including single-particle cryo-electron microscopy (cryo-EM) and enhanced amide hydrogen-deuterium exchange mass spectrometry (DXMS) to determine the location and mode of binding of a VH1-46-encoded antibody, RV6-25. The structure of the RV6-25 antibody-double-layered particle (DLP) complex indicated a very complex binding pattern that revealed subtle differences in accessibility of the VP6 epitope depending on its position in the type I, II, or III channels. These subtle variations in the presentation or accessibility of the RV VP6 capsid layer led to position-specific differences in occupancy for binding of the RV6-25 antibody. The studies also showed that the location of binding of the noninhibitory antibody RV6-25 on the apical surface of RV VP6 head domain does not obstruct the transcription pore upon antibody binding, in contrast to binding of an inhibitory antibody, RV6-26, deeper in the transcriptional pore.


Subject(s)
Antibodies, Viral/immunology , Antigens, Viral/immunology , Capsid Proteins/immunology , Epitopes/immunology , Amino Acid Sequence , Base Sequence , Binding Sites, Antibody , Biopolymers/immunology , Cryoelectron Microscopy , DNA Primers , Epitopes/chemistry , Mass Spectrometry , Molecular Sequence Data
12.
Am J Physiol Endocrinol Metab ; 306(5): E503-11, 2014 Mar 01.
Article in English | MEDLINE | ID: mdl-24398401

ABSTRACT

Previously, we demonstrated that high-volume resistance exercise stimulates mitochondrial protein synthesis (a measure of mitochondrial biogenesis) in lean but not obese Zucker rats. Here, we examined factors involved in regulating mitochondrial biogenesis in the same animals. PGC-1α was 45% higher following exercise in obese but not lean animals compared with sedentary counterparts. Interestingly, exercised animals demonstrated greater PPARδ protein in both lean (47%) and obese (>200%) animals. AMPK phosphorylation (300%) and CPT-I protein (30%) were elevated by exercise in lean animals only, indicating improved substrate availability/flux. These findings suggest that, despite PGC-1α induction, obese animals were resistant to exercise-induced synthesis of new mitochondrial and oxidative protein. Previously, we reported that most anabolic processes are upregulated in these same obese animals regardless of exercise, so the purpose of this study was to assess specific factors associated with the mitochondrial genome as possible culprits for impaired mitochondrial biogenesis. Exercise resulted in higher mRNA contents of mitochondrial transcription factor A (∼50% in each phenotype) and mitochondrial translation initiation factor 2 (31 and 47% in lean and obese, respectively). However, mitochondrial translation elongation factor-Tu mRNA was higher following exercise in lean animals only (40%), suggesting aberrant regulation of mitochondrial translation elongation as a possible culprit in impaired mitochondrial biogenesis following exercise with obesity.


Subject(s)
Mitochondria, Muscle/physiology , Mitochondria/metabolism , Mitochondrial Turnover/physiology , Obesity/metabolism , Physical Conditioning, Animal/physiology , Transcription Factors/metabolism , AMP-Activated Protein Kinases/metabolism , Animals , Mitochondria/genetics , Obesity/genetics , PPAR delta/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha , Phosphorylation , Rats , Rats, Zucker , Transcription Factors/genetics
13.
PLoS Pathog ; 8(2): e1002550, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22383882

ABSTRACT

Ebolaviruses cause hemorrhagic fever with up to 90% lethality and in fatal cases, are characterized by early suppression of the host innate immune system. One of the proteins likely responsible for this effect is VP24. VP24 is known to antagonize interferon signaling by binding host karyopherin α proteins, thereby preventing them from transporting the tyrosine-phosphorylated transcription factor STAT1 to the nucleus. Here, we report that VP24 binds STAT1 directly, suggesting that VP24 can suppress at least two distinct branches of the interferon pathway. Here, we also report the first crystal structures of VP24, derived from different species of ebolavirus that are pathogenic (Sudan) and nonpathogenic to humans (Reston). These structures reveal that VP24 has a novel, pyramidal fold. A site on a particular face of the pyramid exhibits reduced solvent exchange when in complex with STAT1. This site is above two highly conserved pockets in VP24 that contain key residues previously implicated in virulence. These crystal structures and accompanying biochemical analysis map differences between pathogenic and nonpathogenic viruses, offer templates for drug design, and provide the three-dimensional framework necessary for biological dissection of the many functions of VP24 in the virus life cycle.


Subject(s)
Ebolavirus , Protein Folding , STAT1 Transcription Factor/metabolism , Viral Proteins/chemistry , Viral Proteins/metabolism , Amino Acid Sequence , Crystallography, X-Ray , Ebolavirus/metabolism , HEK293 Cells , Humans , Interferons/antagonists & inhibitors , Models, Molecular , Molecular Conformation , Molecular Sequence Data , Protein Binding , Protein Interaction Domains and Motifs/genetics , STAT1 Transcription Factor/chemistry , STAT1 Transcription Factor/genetics , Viral Proteins/genetics , alpha Karyopherins/chemistry , alpha Karyopherins/metabolism
14.
Ann Vasc Surg ; 28(2): 318-23, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24084271

ABSTRACT

BACKGROUND: To investigate the clinical outcomes in patients with renal vein anomalies who undergo inferior vena cava (IVC) filter placement. METHODS: Contrast-enhanced computed tomography images of 410 patients who underwent IVC filter placement were retrospectively reviewed to detect renal vein anomalies. Clinical outcomes involving de novo pulmonary embolism and worsening of renal function were compared between patients with the location of filters placed in relation to the anomalous renal veins versus not in relation to any renal veins. RESULTS: A total of 97 (23.7%) renal vein anomalies were identified: 62 (15.1%) multiple right renal veins, 23 (5.6%) circumaortic left renal veins, 10 (2.4%) retroaortic left renal veins, and 2 (0.5%) accessory left renal veins. Frequency of de novo pulmonary embolism in patients with circumaortic left renal veins who had filters placed at or in between the 2 left renal veins was not significantly different from patients who underwent infra- or suprarenal filter placement (5.9% [1/17] vs. 3.1% [12/387]; P = 0.433). The frequency of patients who had a >25% decrease in estimated glomerular filtration rate after IVC filter placement was not significantly different whether the filter was placed in an infrarenal location or at or above the level of the anomalous renal veins (11.0% [37/335] vs. 17.6% [6/34]; P = 0.261). CONCLUSIONS: Clinical outcomes involving the frequency of de novo pulmonary embolism and worsening of renal function are not dependent on location of IVC filter placement in patients with renal vein anomalies.


Subject(s)
Kidney Diseases/complications , Prosthesis Implantation/instrumentation , Pulmonary Embolism/prevention & control , Renal Veins/abnormalities , Vascular Malformations/complications , Vena Cava Filters , Vena Cava, Inferior , Venous Thrombosis/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Child , Contrast Media , Female , Glomerular Filtration Rate , Humans , Kidney/physiopathology , Kidney Diseases/diagnosis , Kidney Diseases/physiopathology , Male , Middle Aged , Phlebography/methods , Prosthesis Implantation/adverse effects , Pulmonary Embolism/etiology , Renal Veins/diagnostic imaging , Retrospective Studies , Risk Factors , Tomography, X-Ray Computed , Treatment Outcome , Vascular Malformations/diagnostic imaging , Vena Cava, Inferior/diagnostic imaging , Venous Thrombosis/complications , Venous Thrombosis/diagnostic imaging , Young Adult
15.
J Am Vet Med Assoc ; 262(8): 1-5, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38701838

ABSTRACT

OBJECTIVE: To determine the value veterinary students place on nonpecuniary job benefits related to working arrangements. SAMPLE: 381 companion animal-focused veterinary students at 14 US veterinary colleges. METHODS: We employed a survey with a choice-based conjoint experiment. The experimental data were analyzed with a random parameter logit model, from which willingness to accept was calculated. RESULTS: The results indicated that students would prefer working 4 days a week and closer to 40 hours per week, with 13 days of paid time off. Flexible working arrangements were valued from approximately $1,500 to $3,400, depending on the attribute being analyzed. Paid time off was most highly valued. CLINICAL RELEVANCE: These results will help employers better identify the current preferences of soon-to-be associate veterinarians and can match job offer/working arrangements to enhance recruitment and retention within veterinary practices.


Subject(s)
Salaries and Fringe Benefits , Students , Salaries and Fringe Benefits/statistics & numerical data , Humans , Students/psychology , Female , Male , Education, Veterinary/economics , Veterinarians/psychology , Career Choice , Adult , Surveys and Questionnaires , Young Adult , Data Collection , United States , Animals
16.
Cell Rep ; 43(3): 113881, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38442019

ABSTRACT

An intriguing effect of short-term caloric restriction (CR) is the expansion of certain stem cell populations, including muscle stem cells (satellite cells), which facilitate an accelerated regenerative program after injury. Here, we utilized the MetRSL274G (MetRS) transgenic mouse to identify liver-secreted plasminogen as a candidate for regulating satellite cell expansion during short-term CR. Knockdown of circulating plasminogen prevents satellite cell expansion during short-term CR. Furthermore, loss of the plasminogen receptor KT (Plg-RKT) is also sufficient to prevent CR-related satellite cell expansion, consistent with direct signaling of plasminogen through the plasminogen receptor Plg-RKT/ERK kinase to promote proliferation of satellite cells. Importantly, we are able to replicate many of these findings in human participants from the CALERIE trial. Our results demonstrate that CR enhances liver protein secretion of plasminogen, which signals directly to the muscle satellite cell through Plg-RKT to promote proliferation and subsequent muscle resilience during CR.


Subject(s)
Plasminogen , Receptors, Cell Surface , Mice , Animals , Humans , Plasminogen/metabolism , Receptors, Cell Surface/metabolism , Caloric Restriction , Liver/metabolism , Mice, Transgenic , Serine Proteases , Cell Proliferation , Muscles/metabolism
17.
Int J Gynaecol Obstet ; 162(3): 823-828, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36965125

ABSTRACT

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare phenomenon that can present in the postpartum period. We show the experience of a 35-year-old patient who presented with headache after an uncomplicated pregnancy and vaginal delivery. She was initially diagnosed with pre-eclampsia, and subsequently with RCVS following discovery of multifocal vascular narrowing on magnetic resonance arteriography (MRA). Verapamil was initiated, and at 1 month there was improvement intracranially, but cervical vertebral arterial narrowing, likely dissection, was discovered. Verapamil was continued and aspirin was initiated. Follow-up imaging 5 months postpartum demonstrated near-complete resolution of previously noted abnormalities, which remained stable at reimaging at 10 months postpartum. In conclusion, the symptoms of RCVS can mimic or coexist with pre-eclampsia. Early intracranial imaging such as MRA can permit timely diagnosis and facilitate appropriate management and follow-up.


Subject(s)
Pre-Eclampsia , Pregnancy , Female , Humans , Adult , Vasoconstriction , Magnetic Resonance Imaging , Postpartum Period , Verapamil
18.
Nat Aging ; 3(8): 948-964, 2023 08.
Article in English | MEDLINE | ID: mdl-37500973

ABSTRACT

Heterochronic parabiosis (HPB) is known for its functional rejuvenation effects across several mouse tissues. However, its impact on biological age and long-term health is unknown. Here we performed extended (3-month) HPB, followed by a 2-month detachment period of anastomosed pairs. Old detached mice exhibited improved physiological parameters and lived longer than control isochronic mice. HPB drastically reduced the epigenetic age of blood and liver based on several clock models using two independent platforms. Remarkably, this rejuvenation effect persisted even after 2 months of detachment. Transcriptomic and epigenomic profiles of anastomosed mice showed an intermediate phenotype between old and young, suggesting a global multi-omic rejuvenation effect. In addition, old HPB mice showed gene expression changes opposite to aging but akin to several life span-extending interventions. Altogether, we reveal that long-term HPB results in lasting epigenetic and transcriptome remodeling, culminating in the extension of life span and health span.


Subject(s)
Longevity , Rejuvenation , Mice , Animals , Longevity/genetics , Multiomics , Aging/genetics
19.
Biomed Opt Express ; 14(12): 6114-6126, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38420330

ABSTRACT

We used diffuse reflectance spectroscopy to quantify tissue absorption and scattering-based parameters in similarly sized tumors derived from a panel of four isogenic murine breast cancer cell lines (4T1, 4T07, 168FARN, 67NR) that are each capable of accomplishing different steps of the invasion-metastasis cascade. We found lower tissue scattering, increased hemoglobin concentration, and lower vascular oxygenation in indolent 67NR tumors incapable of metastasis compared with aggressive 4T1 tumors capable of metastasis. Supervised learning statistical approaches were able to accurately differentiate between tumor groups and classify tumors according to their ability to accomplish each step of the invasion-metastasis cascade. We investigated whether the inhibition of metastasis-promoting genes in the highly metastatic 4T1 tumors resulted in measurable optical changes that made these tumors similar to the indolent 67NR tumors. These results demonstrate the potential of diffuse reflectance spectroscopy to noninvasively evaluate tumor biology and discriminate between indolent and aggressive tumors.

20.
Nat Commun ; 13(1): 7613, 2022 Dec 09.
Article in English | MEDLINE | ID: mdl-36494364

ABSTRACT

Pathologies associated with sarcopenia include decline in muscular strength, lean mass and regenerative capacity. Despite the substantial impact on quality of life, no pharmacological therapeutics are available to counteract the age-associated decline in functional capacity and/or, resilience. Evidence suggests immune-secreted cytokines can improve muscle regeneration, a strategy which we leverage in this study by rescuing the age-related deficiency in Meteorin-like through several in vivo add-back models. Notably, the intramuscular, peptide injection of recombinant METRNL was sufficient to improve muscle regeneration in aging. Using ex vivo media exchange and in vivo TNF inhibition, we demonstrate a mechanism of METRNL action during regeneration, showing it counteracts a pro-fibrotic gene program by triggering TNFα-induced apoptosis of fibro/adipogenic progenitor cells. These findings demonstrate therapeutic applications for METRNL to improve aged muscle, and show Fibro/Adipogenic Progenitors are viable therapeutic targets to counteract age-related loss in muscle resilience.


Subject(s)
Muscle, Skeletal , Quality of Life , Muscle, Skeletal/physiology , Adipogenesis , Stem Cells , Cytokines
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