Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 58
Filter
1.
Proc Natl Acad Sci U S A ; 120(27): e2211041120, 2023 07 04.
Article in English | MEDLINE | ID: mdl-37364105

ABSTRACT

The molecular events governing skeletal muscle glucose uptake have pharmacological potential for managing insulin resistance in conditions such as obesity, diabetes, and cancer. With no current pharmacological treatments to target skeletal muscle insulin sensitivity, there is an unmet need to identify the molecular mechanisms that control insulin sensitivity in skeletal muscle. Here, the Rho guanine dissociation inhibitor α (RhoGDIα) is identified as a point of control in the regulation of insulin sensitivity. In skeletal muscle cells, RhoGDIα interacted with, and thereby inhibited, the Rho GTPase Rac1. In response to insulin, RhoGDIα was phosphorylated at S101 and Rac1 dissociated from RhoGDIα to facilitate skeletal muscle GLUT4 translocation. Accordingly, siRNA-mediated RhoGDIα depletion increased Rac1 activity and elevated GLUT4 translocation. Consistent with RhoGDIα's inhibitory effect, rAAV-mediated RhoGDIα overexpression in mouse muscle decreased insulin-stimulated glucose uptake and was detrimental to whole-body glucose tolerance. Aligning with RhoGDIα's negative role in insulin sensitivity, RhoGDIα protein content was elevated in skeletal muscle from insulin-resistant patients with type 2 diabetes. These data identify RhoGDIα as a clinically relevant controller of skeletal muscle insulin sensitivity and whole-body glucose homeostasis, mechanistically by modulating Rac1 activity.


Subject(s)
Diabetes Mellitus, Type 2 , Insulin Resistance , rho Guanine Nucleotide Dissociation Inhibitor alpha , Animals , Mice , Diabetes Mellitus, Type 2/metabolism , Glucose/metabolism , Insulin/metabolism , Muscle, Skeletal/metabolism , rac1 GTP-Binding Protein/metabolism , rho Guanine Nucleotide Dissociation Inhibitor alpha/metabolism
2.
Org Biomol Chem ; 21(32): 6493-6497, 2023 Aug 16.
Article in English | MEDLINE | ID: mdl-37529886

ABSTRACT

In this work, we wish to present a nickel-catalyzed divergent ring-contraction and ring-opening/isomerization reaction of tert-cyclobutanols. The key to control these two different reaction pathways is to choose appropriate boronic acid, where the use of phenylboronic acid and pyrimidin-5-ylboronic acid enables a ring-contraction and ring-opening reaction/isomerization, respectively. Both cyclopropyl aryl methanones and 1-aryl butan-1-ones could be selectively obtained.

3.
Org Biomol Chem ; 21(16): 3360-3364, 2023 Apr 26.
Article in English | MEDLINE | ID: mdl-37038990

ABSTRACT

Herein, we describe a nickel-catalyzed divergent formylation and carboxylation reaction of aryl halides with isocyanides. A rich array of aromatic aldehydes and carboxylic acids can be, respectively, accessed in moderate to good yields. Some sensitive functional groups such as hydroxyl, iodine, cyano, and indolyl are fairly tolerant of nickel catalysis. In the carboxylation reactions, the combination of isocyanide and H2O is first employed as a promising carbonyl surrogate instead of gaseous CO and CO2.

4.
Mol Cell Proteomics ; 20: 100030, 2021.
Article in English | MEDLINE | ID: mdl-33583770

ABSTRACT

Many cell surface and secreted proteins are modified by the covalent addition of glycans that play an important role in the development of multicellular organisms. These glycan modifications enable communication between cells and the extracellular matrix via interactions with specific glycan-binding lectins and the regulation of receptor-mediated signaling. Aberrant protein glycosylation has been associated with the development of several muscular diseases, suggesting essential glycan- and lectin-mediated functions in myogenesis and muscle development, but our molecular understanding of the precise glycans, catalytic enzymes, and lectins involved remains only partially understood. Here, we quantified dynamic remodeling of the membrane-associated proteome during a time-course of myogenesis in cell culture. We observed wide-spread changes in the abundance of several important lectins and enzymes facilitating glycan biosynthesis. Glycomics-based quantification of released N-linked glycans confirmed remodeling of the glycome consistent with the regulation of glycosyltransferases and glycosidases responsible for their formation including a previously unknown digalactose-to-sialic acid switch supporting a functional role of these glycoepitopes in myogenesis. Furthermore, dynamic quantitative glycoproteomic analysis with multiplexed stable isotope labeling and analysis of enriched glycopeptides with multiple fragmentation approaches identified glycoproteins modified by these regulated glycans including several integrins and growth factor receptors. Myogenesis was also associated with the regulation of several lectins, most notably the upregulation of galectin-1 (LGALS1). CRISPR/Cas9-mediated deletion of Lgals1 inhibited differentiation and myotube formation, suggesting an early functional role of galectin-1 in the myogenic program. Importantly, similar changes in N-glycosylation and the upregulation of galectin-1 during postnatal skeletal muscle development were observed in mice. Treatment of new-born mice with recombinant adeno-associated viruses to overexpress galectin-1 in the musculature resulted in enhanced muscle mass. Our data form a valuable resource to further understand the glycobiology of myogenesis and will aid the development of intervention strategies to promote healthy muscle development or regeneration.


Subject(s)
Galectin 1/metabolism , Glycopeptides/metabolism , Muscle Development , Animals , Cell Line , Galectin 1/genetics , Glycomics , Glycosylation , Male , Mice, Inbred C57BL , Muscle, Skeletal/metabolism , Protein Processing, Post-Translational , Proteomics , Rats
5.
Molecules ; 27(24)2022 Dec 14.
Article in English | MEDLINE | ID: mdl-36558010

ABSTRACT

Dynamic emissive materials in aqueous media have received much attention owing to their ease of preparation, tunable luminescence and environmental friendliness. However, hydrophobic fluorophores usually suffer from aggregation-caused quenching in water. In this work, we constructed an artificial light-harvesting system by using a non-covalent aggregation-induced emission dimer as antenna and energy donor. The dimer is quadruple hydrogen bonded from a ureidopyrimidinone derivative (M) containing a tetraphenylethylene group. The dispersed nano-assemblies based on the dimer in aqueous media were fabricated with the help of surfactant. By loading a hydrophobic acceptor molecule DBT into the nano-assemblies, man-made light-harvesting nanoparticles were fabricated, showing considerable energy transfer efficiency and a relatively high antenna effect. Additionally, the fluorescence color of the system can be gradually tuned by varying the content of the acceptors. This study provides a general way for the construction of an aqueous light-harvesting system based on a supramolecular dimer, which is important for potential application in luminescent materials.


Subject(s)
Nanoparticles , Water , Humans , Water/chemistry , Light , Energy Transfer , Luminescence
6.
FASEB J ; 34(4): 5697-5714, 2020 04.
Article in English | MEDLINE | ID: mdl-32141144

ABSTRACT

Type 2 diabetes (T2D) manifests from inadequate glucose control due to insulin resistance, hypoinsulinemia, and deteriorating pancreatic ß-cell function. The pro-inflammatory factor Activin has been implicated as a positive correlate of severity in T2D patients, and as a negative regulator of glucose uptake by skeletal muscle, and of pancreatic ß-cell phenotype in mice. Accordingly, we sought to determine whether intervention with the Activin antagonist Follistatin can ameliorate the diabetic pathology. Here, we report that an intravenous Follistatin gene delivery intervention with tropism for striated muscle reduced the serum concentrations of Activin B and improved glycemic control in the db/db mouse model of T2D. Treatment reversed the hyperglycemic progression with a corresponding reduction in the percentage of glycated-hemoglobin to levels similar to lean, healthy mice. Follistatin gene delivery promoted insulinemia and abundance of insulin-positive pancreatic ß-cells, even when treatment was administered to mice with advanced diabetes, supporting a mechanism for improved glycemic control associated with maintenance of functional ß-cells. Our data demonstrate that single-dose intravascular Follistatin gene delivery can ameliorate the diabetic progression and improve prognostic markers of disease. These findings are consistent with other observations of Activin-mediated mechanisms exerting deleterious effects in models of obesity and diabetes, and suggest that interventions that attenuate Activin signaling could help further understanding of T2D and the development of novel T2D therapeutics.


Subject(s)
Diabetes Mellitus, Experimental/therapy , Diabetes Mellitus, Type 2/therapy , Follistatin/genetics , Gene Transfer Techniques , Genetic Therapy , Glycemic Control , Hyperglycemia/therapy , Administration, Intravenous , Animals , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/pathology , Follistatin/administration & dosage , Hyperglycemia/genetics , Insulin Resistance , Mice
7.
Am J Physiol Heart Circ Physiol ; 318(4): H840-H852, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32142359

ABSTRACT

Diabetic cardiomyopathy is a distinct form of heart disease that represents a major cause of death and disability in diabetic patients, particularly, the more prevalent type 2 diabetes patient population. In the current study, we investigated whether administration of recombinant adeno-associated viral vectors carrying a constitutively active phosphoinositide 3-kinase (PI3K)(p110α) construct (rAAV6-caPI3K) at a clinically relevant time point attenuates diabetic cardiomyopathy in a preclinical type 2 diabetes (T2D) model. T2D was induced by a combination of a high-fat diet (42% energy intake from lipid) and low-dose streptozotocin (three consecutive intraperitoneal injections of 55 mg/kg body wt), and confirmed by increased body weight, mild hyperglycemia, and impaired glucose tolerance (all P < 0.05 vs. nondiabetic mice). After 18 wk of untreated diabetes, impaired left ventricular (LV) systolic dysfunction was evident, as confirmed by reduced fractional shortening and velocity of circumferential fiber shortening (Vcfc, all P < 0.01 vs. baseline measurement). A single tail vein injection of rAAV6-caPI3K gene therapy (2×1011vector genomes) was then administered. Mice were followed for an additional 8 wk before end point. A single injection of cardiac targeted rAAV6-caPI3K attenuated diabetes-induced cardiac remodeling by limiting cardiac fibrosis (reduced interstitial and perivascular collagen deposition, P < 0.01 vs. T2D mice) and cardiomyocyte hypertrophy (reduced cardiomyocyte size and Nppa gene expression, P < 0.001 and P < 0.05 vs. T2D mice, respectively). The diabetes-induced LV systolic dysfunction was reversed with rAAV6-caPI3K, as demonstrated by improved fractional shortening and velocity of circumferential fiber shortening (all P < 0.05 vs pre-AAV measurement). This cardioprotection occurred in combination with reduced LV reactive oxygen species (P < 0.05 vs. T2D mice) and an associated decrease in markers of endoplasmic reticulum stress (reduced Grp94 and Chop, all P < 0.05 vs. T2D mice). Together, our findings demonstrate that a cardiac-selective increase in PI3K(p110α), via rAAV6-caPI3K, attenuates T2D-induced diabetic cardiomyopathy, providing proof of concept for potential translation to the clinic.NEW & NOTEWORTHY Diabetes remains a major cause of death and disability worldwide (and its resultant heart failure burden), despite current care. The lack of existing management of heart failure in the context of the poorer prognosis of concomitant diabetes represents an unmet clinical need. In the present study, we now demonstrate that delayed intervention with PI3K gene therapy (rAAV6-caPI3K), administered as a single dose in mice with preexisting type 2 diabetes, attenuates several characteristics of diabetic cardiomyopathy, including diabetes-induced impairments in cardiac remodeling, oxidative stress, and function. Our discovery here contributes to the previous body of work, suggesting the cardioprotective effects of PI3K(p110α) could be a novel therapeutic approach to reduce the progression to heart failure and death in diabetes-affected patients.


Subject(s)
Class I Phosphatidylinositol 3-Kinases/genetics , Diabetes Mellitus, Type 2/complications , Diabetic Cardiomyopathies/therapy , Genetic Therapy/methods , Animals , Class I Phosphatidylinositol 3-Kinases/metabolism , Dependovirus/genetics , Dependovirus/metabolism , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Type 2/etiology , Diabetic Cardiomyopathies/etiology , Diabetic Cardiomyopathies/pathology , Diet, High-Fat/adverse effects , Endoplasmic Reticulum Stress , Fibrosis , Genetic Vectors/genetics , Genetic Vectors/metabolism , Male , Mice , Myocardium/metabolism , Reactive Oxygen Species , Ventricular Remodeling
8.
Proc Natl Acad Sci U S A ; 114(26): E5266-E5275, 2017 06 27.
Article in English | MEDLINE | ID: mdl-28607086

ABSTRACT

The transforming growth factor-ß (TGF-ß) network of ligands and intracellular signaling proteins is a subject of intense interest within the field of skeletal muscle biology. To define the relative contribution of endogenous TGF-ß proteins to the negative regulation of muscle mass via their activation of the Smad2/3 signaling axis, we used local injection of adeno-associated viral vectors (AAVs) encoding ligand-specific antagonists into the tibialis anterior (TA) muscles of C57BL/6 mice. Eight weeks after AAV injection, inhibition of activin A and activin B signaling produced moderate (∼20%), but significant, increases in TA mass, indicating that endogenous activins repress muscle growth. Inhibiting myostatin induced a more profound increase in muscle mass (∼45%), demonstrating a more prominent role for this ligand as a negative regulator of adult muscle mass. Remarkably, codelivery of activin and myostatin inhibitors induced a synergistic response, resulting in muscle mass increasing by as much as 150%. Transcription and protein analysis indicated that this substantial hypertrophy was associated with both the complete inhibition of the Smad2/3 pathway and activation of the parallel bone morphogenetic protein (BMP)/Smad1/5 axis (recently identified as a positive regulator of muscle mass). Analyses indicated that hypertrophy was primarily driven by an increase in protein synthesis, but a reduction in ubiquitin-dependent protein degradation pathways was also observed. In models of muscular dystrophy and cancer cachexia, combined inhibition of activins and myostatin increased mass or prevented muscle wasting, respectively, highlighting the potential therapeutic advantages of specifically targeting multiple Smad2/3-activating ligands in skeletal muscle.


Subject(s)
Dependovirus , Genetic Vectors , Muscle Proteins , Muscle, Skeletal/growth & development , Muscular Diseases , Signal Transduction , Transforming Growth Factor beta , Activins/antagonists & inhibitors , Activins/genetics , Activins/metabolism , Animals , Gene Targeting , Male , Mice , Muscle Proteins/antagonists & inhibitors , Muscle Proteins/genetics , Muscle Proteins/metabolism , Muscle, Skeletal/pathology , Muscular Diseases/genetics , Muscular Diseases/metabolism , Muscular Diseases/pathology , Organ Size/genetics , Smad Proteins/genetics , Smad Proteins/metabolism , Transforming Growth Factor beta/antagonists & inhibitors , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/metabolism
9.
Clin Sci (Lond) ; 132(3): 381-397, 2018 02 14.
Article in English | MEDLINE | ID: mdl-29358507

ABSTRACT

We previously showed that medium chain acyl-coenzyme A dehydrogenase (MCAD, key regulator of fatty acid oxidation) is positively modulated in the heart by the cardioprotective kinase, phosphoinositide 3-kinase (PI3K(p110α)). Disturbances in cardiac metabolism are a feature of heart failure (HF) patients and targeting metabolic defects is considered a potential therapeutic approach. The specific role of MCAD in the adult heart is unknown. To examine the role of MCAD in the heart and to assess the therapeutic potential of increasing MCAD in the failing heart, we developed a gene therapy tool using recombinant adeno-associated viral vectors (rAAV) encoding MCAD. We hypothesised that increasing MCAD expression may recapitulate the cardioprotective properties of PI3K(p110α). rAAV6:MCAD or rAAV6:control was delivered to healthy adult mice and to mice with pre-existing pathological hypertrophy and cardiac dysfunction due to transverse aortic constriction (TAC). In healthy mice, rAAV6:MCAD induced physiological hypertrophy (increase in heart size, normal systolic function and increased capillary density). In response to TAC (~15 weeks), heart weight/tibia length increased by ~60% in control mice and ~45% in rAAV6:MCAD mice compared with sham. This was associated with an increase in cardiomyocyte cross-sectional area in both TAC groups which was similar. However, hypertrophy in TAC rAAV6:MCAD mice was associated with less fibrosis, a trend for increased capillary density and a more favourable molecular profile compared with TAC rAAV6:control mice. In summary, MCAD induced physiological cardiac hypertrophy in healthy adult mice and attenuated features of pathological remodelling in a cardiac disease model.


Subject(s)
Cardiomegaly/therapy , Genetic Therapy , Heart Failure/drug therapy , Protective Agents/pharmacology , Animals , Cardiomegaly/genetics , Disease Models, Animal , Male , Mice, Inbred C57BL , Myocardium/pathology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/pathology , Phosphatidylinositol 3-Kinase/drug effects , Phosphatidylinositol 3-Kinases/genetics
10.
Diabetes Obes Metab ; 20(8): 1928-1936, 2018 08.
Article in English | MEDLINE | ID: mdl-29652108

ABSTRACT

AIMS: The induction of heat shock protein 72 (Hsp72) via heating, genetic manipulation or pharmacological activation is metabolically protective in the setting of obesity-induced insulin resistance across mammalian species. In this study, we set out to determine whether the overexpression of Hsp72, specifically in skeletal muscle, can protect against high-fat diet (HFD)-induced obesity and insulin resistance. MATERIALS AND METHODS: An Adeno-Associated Viral vector (AAV), designed to overexpress Hsp72 in skeletal muscle only, was used to study the effects of increasing Hsp72 levels on various metabolic parameters. Two studies were conducted, the first with direct intramuscular (IM) injection of the AAV:Hsp72 into the tibialis anterior hind-limb muscle and the second with a systemic injection to enable body-wide skeletal muscle transduction. RESULTS: IM injection of the AAV:Hsp72 significantly improved skeletal muscle insulin-stimulated glucose clearance in treated hind-limb muscles, as compared with untreated muscles of the contralateral leg when mice were fed an HFD. Despite this finding, systemic administration of AAV:Hsp72 did not improve body composition parameters such as body weight, fat mass or percentage body fat, nor did it lead to an improvement in fasting glucose levels or glucose tolerance. Furthermore, no differences were observed for other metabolic parameters such as whole-body oxygen consumption, energy expenditure or physical activity levels. CONCLUSIONS: At the levels of Hsp72 over-expression reported herein, skeletal muscle-specific Hsp72 overexpression via IM injection has the capacity to increase insulin-stimulated glucose clearance in this muscle. However, upon systemic injection, which results in lower muscle Hsp72 overexpression, no beneficial effects on whole-body metabolism are observed.


Subject(s)
Energy Metabolism/drug effects , Glucose Intolerance/prevention & control , HSP72 Heat-Shock Proteins/metabolism , Hypoglycemic Agents/therapeutic use , Insulin Resistance , Insulin/therapeutic use , Muscle, Skeletal/drug effects , Absorption, Physiological/drug effects , Animals , Brain/drug effects , Brain/metabolism , Diet, High-Fat/adverse effects , Gene Transfer Techniques , Glucose/metabolism , Glucose Intolerance/blood , Glucose Intolerance/etiology , Glucose Intolerance/metabolism , HSP72 Heat-Shock Proteins/genetics , Male , Mice, Inbred C57BL , Mice, Transgenic , Muscle, Skeletal/metabolism , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Neurons/drug effects , Neurons/metabolism , Obesity/etiology , Obesity/metabolism , Obesity/physiopathology , Organ Specificity , Pilot Projects , Rats
11.
Clin Sci (Lond) ; 131(12): 1345-1360, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-28487469

ABSTRACT

Phosphoinositide 3-kinase [PI3K (p110α)] is able to negatively regulate the diabetes-induced increase in NADPH oxidase in the heart. Patients affected by diabetes exhibit significant cardiovascular morbidity and mortality, at least in part due to a cardiomyopathy characterized by oxidative stress and left ventricular (LV) dysfunction. Thus, PI3K (p110α) may represent a novel approach to protect the heart from diabetes-induced cardiac oxidative stress and dysfunction. In the present study, we investigated the therapeutic potential of a delayed intervention with cardiac-targeted PI3K gene therapy, administered to mice with established diabetes-induced LV diastolic dysfunction. Diabetes was induced in 6-week-old male mice by streptozotocin (STZ). After 8 weeks of untreated diabetes, LV diastolic dysfunction was confirmed by a reduction in echocardiography-derived transmitral E/A ratio. Diabetic and non-diabetic mice were randomly allocated to receive either recombinant adeno-associated viral vector-6 carrying a constitutively-active PI3K construct (recombinant adeno-associated-virus 6-constitutively active PI3K (p110α) (caPI3K) (rAAV6-caPI3K), single i.v. injection, 2 × 1011 vector genomes) or null vector, and were followed for a further 6 or 8 weeks. At study endpoint, diabetes-induced LV dysfunction was significantly attenuated by a single administration of rAAV6-caPI3K, administered 8 weeks after the induction of diabetes. Diabetes-induced impairments in each of LV NADPH oxidase, endoplasmic reticulum (ER) stress, apoptosis, cardiac fibrosis and cardiomyocyte hypertrophy, in addition to LV systolic dysfunction, were attenuated by delayed intervention with rAAV6-caPI3K. Hence, our demonstration that cardiac-targeted PI3K (p110α) gene therapy limits diabetes-induced up-regulation of NADPH oxidase and cardiac remodelling suggests new insights into promising approaches for the treatment of diabetic cardiomyopathy, at a clinically relevant time point (after diastolic dysfunction is manifested).


Subject(s)
Diabetic Cardiomyopathies/prevention & control , Genetic Therapy/methods , Myocardium/enzymology , NADPH Oxidases/metabolism , Phosphatidylinositol 3-Kinase/biosynthesis , Ventricular Dysfunction, Left/prevention & control , Ventricular Function, Left , Animals , Dependovirus/genetics , Diabetes Mellitus, Experimental/complications , Diabetic Cardiomyopathies/enzymology , Diabetic Cardiomyopathies/genetics , Diabetic Cardiomyopathies/physiopathology , Diastole , Genetic Vectors , Male , Mice , Myocardium/pathology , Phosphatidylinositol 3-Kinase/genetics , Signal Transduction , Time Factors , Transduction, Genetic , Ventricular Dysfunction, Left/enzymology , Ventricular Dysfunction, Left/genetics , Ventricular Dysfunction, Left/physiopathology , Ventricular Remodeling
12.
Mol Ther ; 23(3): 434-44, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25399825

ABSTRACT

Soluble activin type II receptors (ActRIIA/ActRIIB), via binding to diverse TGF-ß proteins, can increase muscle and bone mass, correct anemia or protect against diet-induced obesity. While exciting, these multiple actions of soluble ActRIIA/IIB limit their therapeutic potential and highlight the need for new reagents that target specific ActRIIA/IIB ligands. Here, we modified the activin A and activin B prodomains, regions required for mature growth factor synthesis, to generate specific activin antagonists. Initially, the prodomains were fused to the Fc region of mouse IgG2A antibody and, subsequently, "fastener" residues (Lys(45), Tyr(96), His(97), and Ala(98); activin A numbering) that confer latency to other TGF-ß proteins were incorporated. For the activin A prodomain, these modifications generated a reagent that potently (IC(50) 5 nmol/l) and specifically inhibited activin A signaling in vitro, and activin A-induced muscle wasting in vivo. Interestingly, the modified activin B prodomain inhibited both activin A and B signaling in vitro (IC(50) ~2 nmol/l) and in vivo, suggesting it could serve as a general activin antagonist. Importantly, unlike soluble ActRIIA/IIB, the modified prodomains did not inhibit myostatin or GDF-11 activity. To underscore the therapeutic utility of specifically antagonising activin signaling, we demonstrate that the modified activin prodomains promote significant increases in muscle mass.


Subject(s)
Activins/metabolism , Genetic Engineering/methods , Muscle, Skeletal/metabolism , Recombinant Fusion Proteins/metabolism , Signal Transduction , Activins/antagonists & inhibitors , Activins/genetics , Animals , Bone Morphogenetic Proteins/genetics , Bone Morphogenetic Proteins/metabolism , Dependovirus/genetics , Gene Expression Regulation , Genetic Vectors/genetics , Growth Differentiation Factors/genetics , Growth Differentiation Factors/metabolism , HEK293 Cells , Humans , Immunoglobulin Fc Fragments/genetics , Immunoglobulin Fc Fragments/metabolism , Immunoglobulin G/genetics , Immunoglobulin G/metabolism , Male , Mice , Mice, Inbred C57BL , Muscle, Skeletal/pathology , Myostatin/genetics , Myostatin/metabolism , Plasmids/chemistry , Plasmids/metabolism , Protein Structure, Tertiary , Recombinant Fusion Proteins/genetics , Transfection , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/metabolism
13.
J Cell Sci ; 126(Pt 23): 5377-90, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24046455

ABSTRACT

The angiotensin type 1 receptor (AT1R) transactivates the epidermal growth factor receptor (EGFR) to mediate cellular growth, however, the molecular mechanisms involved have not yet been resolved. To address this, we performed a functional siRNA screen of the human kinome in human mammary epithelial cells that demonstrate a robust AT1R-EGFR transactivation. We identified a suite of genes encoding proteins that both positively and negatively regulate AT1R-EGFR transactivation. Many candidates are components of EGFR signalling networks, whereas others, including TRIO, BMX and CHKA, have not been previously linked to EGFR transactivation. Individual knockdown of TRIO, BMX or CHKA attenuated tyrosine phosphorylation of the EGFR by angiotensin II stimulation, but this did not occur following direct stimulation of the EGFR with EGF, indicating that these proteins function between the activated AT1R and the EGFR. Further investigation of TRIO and CHKA revealed that their activity is likely to be required for AT1R-EGFR transactivation. CHKA also mediated EGFR transactivation in response to another G protein-coupled receptor (GPCR) ligand, thrombin, indicating a pervasive role for CHKA in GPCR-EGFR crosstalk. Our study reveals the power of unbiased, functional genomic screens to identify new signalling mediators important for tissue remodelling in cardiovascular disease and cancer.


Subject(s)
Epithelial Cells/metabolism , ErbB Receptors/metabolism , Mammary Glands, Human/metabolism , Receptor, Angiotensin, Type 1/metabolism , Transcriptional Activation , Angiotensin II/metabolism , Angiotensin II/pharmacology , Cell Line, Transformed , Choline Kinase/antagonists & inhibitors , Choline Kinase/genetics , Choline Kinase/metabolism , Epidermal Growth Factor/metabolism , Epidermal Growth Factor/pharmacology , Epithelial Cells/cytology , Epithelial Cells/drug effects , ErbB Receptors/genetics , Female , Guanine Nucleotide Exchange Factors/antagonists & inhibitors , Guanine Nucleotide Exchange Factors/genetics , Guanine Nucleotide Exchange Factors/metabolism , Humans , Mammary Glands, Human/cytology , Mammary Glands, Human/drug effects , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Receptor, Angiotensin, Type 1/genetics , Signal Transduction , Thrombin/metabolism , Thrombin/pharmacology
14.
FASEB J ; 28(4): 1711-23, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24378873

ABSTRACT

In models of cancer cachexia, inhibiting type IIB activin receptors (ActRIIBs) reverse muscle wasting and prolongs survival, even with continued tumor growth. ActRIIB mediates signaling of numerous TGF-ß proteins; of these, we demonstrate that activins are the most potent negative regulators of muscle mass. To determine whether activin signaling in the absence of tumor-derived factors induces cachexia, we used recombinant serotype 6 adeno-associated virus (rAAV6) vectors to increase circulating activin A levels in C57BL/6 mice. While mice injected with control vector gained ~10% of their starting body mass (3.8±0.4 g) over 10 wk, mice injected with increasing doses of rAAV6:activin A exhibited weight loss in a dose-dependent manner, to a maximum of -12.4% (-4.2±1.1 g). These reductions in body mass in rAAV6:activin-injected mice correlated inversely with elevated serum activin A levels (7- to 24-fold). Mechanistically, we show that activin A reduces muscle mass and function by stimulating the ActRIIB pathway, leading to deleterious consequences, including increased transcription of atrophy-related ubiquitin ligases, decreased Akt/mTOR-mediated protein synthesis, and a profibrotic response. Critically, we demonstrate that the muscle wasting and fibrosis that ensues in response to excessive activin levels is fully reversible. These findings highlight the therapeutic potential of targeting activins in cachexia.


Subject(s)
Activins/genetics , Cachexia/genetics , Gene Expression , Muscular Atrophy/genetics , Activin Receptors, Type II/genetics , Activin Receptors, Type II/metabolism , Activins/blood , Activins/metabolism , Animals , Blotting, Western , Cachexia/metabolism , Cell Line, Tumor , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Dependovirus/genetics , Genetic Vectors/genetics , Humans , MCF-7 Cells , Mice , Mice, Inbred C57BL , Mice, Knockout , Muscle Proteins/genetics , Muscle Proteins/metabolism , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Muscular Atrophy/metabolism , Myostatin/deficiency , Myostatin/genetics , Reverse Transcriptase Polymerase Chain Reaction , SKP Cullin F-Box Protein Ligases/genetics , SKP Cullin F-Box Protein Ligases/metabolism , Signal Transduction/genetics
15.
Med Ultrason ; 26(2): 138-146, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38537183

ABSTRACT

AIM: Prostate cancer (PCa) is one of the most common neoplasms in men. However, the value of ultrasound-based radiomics for diagnosing PCa remains uncertain. MATERIAL AND METHODS: We retrospectively analyzed ultrasonic and clinical data from 373 patients. Patients were divided into two groups according to the pathological results. Radiomics features wereextracted from TRUS, and we screened the optimal features to construct radiomics models. Relationships between clinical characteristics and prostate lesions were identified by univariate and multivariate logistic regression analysis. Finally, a clinical-radiomics model was developed, and then visualized in the form of a nomogram. RESULTS: Of the 373 patients, 178 had benign disease and 195 had malignant disease. The support vector machine (SVM) classification model showed the best performance, while the diagnostic performance of the clinical model was poorer than that of the radiomics model (p<0.05) or the combined (clinical-radiomics) model (p<0.05). In general, the combined model demonstrated the highest AUC and proved to be more advantageous. CONCLUSION: The prediction model we constructed based on TRUS predicted PCa preoperatively with high efficiency. In addition, combining radiomics with clinical factors improved diagnostic accuracy.


Subject(s)
Prostatic Neoplasms , Ultrasonography , Humans , Prostatic Neoplasms/diagnostic imaging , Male , Retrospective Studies , Ultrasonography/methods , Middle Aged , Aged , Prostate/diagnostic imaging , Support Vector Machine , Predictive Value of Tests , Reproducibility of Results , Nomograms , Radiomics
16.
Sci Rep ; 14(1): 11538, 2024 05 21.
Article in English | MEDLINE | ID: mdl-38773179

ABSTRACT

Predicting the biological characteristics of hepatocellular carcinoma (HCC) is essential for personalized treatment. This study explored the role of ultrasound-based radiomics of peritumoral tissues for predicting HCC features, focusing on differentiation, cytokeratin 7 (CK7) and Ki67 expression, and p53 mutation status. A cohort of 153 patients with HCC underwent ultrasound examinations and radiomics features were extracted from peritumoral tissues. Subgroups were formed based on HCC characteristics. Predictive modeling was carried out using the XGBOOST algorithm in the differentiation subgroup, logistic regression in the CK7 and Ki67 expression subgroups, and support vector machine learning in the p53 mutation status subgroups. The predictive models demonstrated robust performance, with areas under the curves of 0.815 (0.683-0.948) in the differentiation subgroup, 0.922 (0.785-1) in the CK7 subgroup, 0.762 (0.618-0.906) in the Ki67 subgroup, and 0.849 (0.667-1) in the p53 mutation status subgroup. Confusion matrices and waterfall plots highlighted the good performance of the models. Comprehensive evaluation was carried out using SHapley Additive exPlanations plots, which revealed notable contributions from wavelet filter features. This study highlights the potential of ultrasound-based radiomics, specifically the importance of peritumoral tissue analysis, for predicting HCC characteristics. The results warrant further validation of peritumoral tissue radiomics in larger, multicenter studies.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Ultrasonography , Humans , Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/pathology , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Male , Female , Ultrasonography/methods , Middle Aged , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Aged , Ki-67 Antigen/metabolism , Mutation , Adult , Radiomics
17.
Front Oncol ; 13: 1209111, 2023.
Article in English | MEDLINE | ID: mdl-37711208

ABSTRACT

Background: Hepatocellular cancer (HCC) is one of the most common tumors worldwide, and Ki-67 is highly important in the assessment of HCC. Our study aimed to evaluate the value of ultrasound radiomics based on intratumoral and peritumoral tissues in predicting Ki-67 expression levels in patients with HCC. Methods: We conducted a retrospective analysis of ultrasonic and clinical data from 118 patients diagnosed with HCC through histopathological examination of surgical specimens in our hospital between September 2019 and January 2023. Radiomics features were extracted from ultrasound images of both intratumoral and peritumoral regions. To select the optimal features, we utilized the t-test and the least absolute shrinkage and selection operator (LASSO). We compared the area under the curve (AUC) values to determine the most effective modeling method. Subsequently, we developed four models: the intratumoral model, the peritumoral model, combined model #1, and combined model #2. Results: Of the 118 patients, 64 were confirmed to have high Ki-67 expression while 54 were confirmed to have low Ki-67 expression. The AUC of the intratumoral model was 0.796 (0.649-0.942), and the AUC of the peritumoral model was 0.772 (0.619-0.926). Furthermore, combined model#1 yielded an AUC of 0.870 (0.751-0.989), and the AUC of combined model#2 was 0.762 (0.605-0.918). Among these models, combined model#1 showed the best performance in terms of AUC, accuracy, F1-score, and decision curve analysis (DCA). Conclusion: We presented an ultrasound radiomics model that utilizes both intratumoral and peritumoral tissue information to accurately predict Ki-67 expression in HCC patients. We believe that incorporating both regions in a proper manner can enhance the diagnostic performance of the prediction model. Nevertheless, it is not sufficient to include both regions in the region of interest (ROI) without careful consideration.

18.
Front Surg ; 9: 922834, 2022.
Article in English | MEDLINE | ID: mdl-36034354

ABSTRACT

Background: Cholangiocarcinoma (CCA) is a type of malignant tumor that arises from the epithelium of the bile ducts. According to anatomical location, CCA can be classified as intrahepatic (ICC), perihilar (PCC), or extrahepatic (ECC). CCA can invade and metastasize to other tissues in various ways, but distal skeletal muscle metastasis (SMM) is extremely rare. There are several reports on SMM from ICC or PCC, but SMM from ECC has not yet been reported. Case presentation: A 71-year-old woman was diagnosed with ECC, for which she underwent pancreatoduodenectomy and partial hepatectomy. Nine months after surgery, she was re-admitted to the hospital complaining of a rapidly growing mass on her right thigh with progressive lower extremity edema. Magnetic resonance imaging of the right thigh showed two masses with iso-signal intensity on T1-weighted images and hyper-intensity on T2-weighted images compared with the surrounding muscles. Pathological examination of the fine-needle biopsy specimen revealed that it was similar to the previously detected ECC, and the diagnosis was metastasis of ECC. The patient was treated with opioid analgesics and died of systemic failure three months later. Conclusion: SMM should be considered during the follow-up period despite its low incidence, and perineural invasion may be an essential pathway of distant metastasis in CCA.

19.
Front Surg ; 9: 907234, 2022.
Article in English | MEDLINE | ID: mdl-36700008

ABSTRACT

Congenital pelvic arteriovenous malformation (AVM) is a rare vascular abnormality whereby arteries and veins are directly connected with malformed vascular plexus. Owing to its low incidence and nonspecific symptoms, the ultrasonographic characteristics of congenital pelvic AVM in males have been infrequently studied. A 30-year-old man visited our hospital complaining of progressive pain in the right lower abdomen and lumbar area since 2 months previously. Abdominal ultrasound (US) was performed at the initial examination and pelvic AVM was diagnosed, which was then confirmed by computed tomographic angiography. After right internal iliac artery embolization, the patient recovered uneventfully and remained asymptomatic during the 12-month follow-up period. Congenital pelvic AVM should thus be included in the differential diagnosis of pelvic cystic masses in males despite its low incidence, with US also being of great diagnostic value. We describe the ultrasonic features of AVM in detail and hope that this study may contribute to the ultrasonic diagnosis of congenital pelvic AVM in males.

20.
Article in English | MEDLINE | ID: mdl-36232241

ABSTRACT

OBJECTIVE: The implementation of online teaching in the context of epidemic prevention and control has had an impact on the learning engagement of college students to some extent. This study aims to investigate the mechanisms that influence perceived social support and health behaviors on learning engagement, so as to make college students more focused on their studies by improving their physical and mental health as well as their ability to perceive social support. METHODS: A total of 538 college students from Henan Province, China, were studied using the Perceived Social Support Scale, Health Behavior Scale and Learning Engagement Scale, and the data were analyzed by IBM SPSS Amos 26.0 software (IBM SPSS Inc., Chicago, IL, USA). RESULTS: (1) The level of health behavior among college students was positively correlated with perceived social support ability (ß = 0.289, p < 0.001); both perceived social support and health behaviors predicted college students' learning engagement significantly (ß = 0.200, p < 0.01; ß = 0.406, p < 0.001). (2) College students' perceived social support partially mediated the relationship between health behaviors and learning engagement. CONCLUSION: One of the main ways to improve college students' learning engagement is to improve their health behavior and perceived social support. This study contributes to a better understanding of the relationships between health behaviors and learning engagement, as well as to the development of interventions to improve learning engagement among college students.


Subject(s)
Social Support , Students , Health Behavior , Humans , Learning , Mental Health
SELECTION OF CITATIONS
SEARCH DETAIL