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The Journal of Endocrinology Jul 2024Irisin is a recently discovered myokine that facilitates the browning of white adipose tissue, increases glucose uptake in skeletal muscle, and influences metabolic...
Irisin is a recently discovered myokine that facilitates the browning of white adipose tissue, increases glucose uptake in skeletal muscle, and influences metabolic processes in the liver. However, its potential effects on amino acid absorption remained largely unexplored. This study aimed to elucidate the role of irisin in modulating amino acid uptake and delineate the underlying molecular mechanisms involved. To this end, juvenile tilapia were administered intraperitoneal irisin injections at 100 ng/g body weight over eight weeks. Evaluation of various physiological parameters revealed that irisin supplementation significantly improved the specific growth rate and feed conversion efficiency while reducing feed consumption. Muscle tissue analysis revealed that irisin significantly modified the proximate composition by increasing protein content and reducing lipid levels. It also significantly raised the levels of both essential and non-essential amino acids in the muscle. Histological analysis demonstrated that irisin stimulated muscle growth through hyperplasia rather than hypertrophy, corroborated by upregulated IGF-1 mRNA and downregulated myostatin mRNA expression. Mechanistic studies in cultured tilapia muscle cells elucidated that irisin activated integrin receptors on muscle cells, which subsequently engaged IGF-1/IGF-1R signaling. Downstream of IGF-1R activation, irisin simultaneously stimulates the ERK1/2 and PI3K/mTORC2/Akt pathways. The convergence of these pathways upregulates L-type amino acid transporter 1 expression, thereby augmenting amino acid uptake into muscle cells. In summary, irisin supplementation in tilapia leads to improved muscle growth, predominantly via hyperplasia and augmented amino acid assimilation, governed by intricate cellular signaling pathways. These findings provide valuable aquaculture applications and novel insights into muscle development.
PubMed: 38954845
DOI: 10.1530/JOE-24-0122 -
American Journal of Physiology.... Jul 2024Crohn's disease (CD) is an inflammatory bowel disease characterized by transmural inflammation and intestinal fibrosis. Mechanisms of fibrosis in CD are not well...
Crohn's disease (CD) is an inflammatory bowel disease characterized by transmural inflammation and intestinal fibrosis. Mechanisms of fibrosis in CD are not well understood. Transmural inflammation is associated with inflammatory cell infiltration, stenosis, and distention, which present mechanical stress (MS) to the bowel wall. We hypothesize that MS induces gene expression of pro-fibrotic mediators such as connective tissue growth factor (CTGF), which may contribute to fibrosis in CD. A rodent model of CD was induced by intracolonic instillation of TNBS to the distal colon. TNBS instillation induced a localized transmural inflammation (site I), with a distended colon segment (site P) proximal to site I. We detected significant fibrosis and collagen content not only in site I, but also in site P in CD rats by day 7. CTGF expression increased significantly in sites P and I, but not in the segment distal to the inflammation site. Increased CTGF expression was detected mainly in the smooth muscle cells (SMC). When rats were fed exclusively with clear liquid diet to prevent mechanical distention in colitis, expression of CTGF in sites P and I was blocked. Direct stretch led to robust expression of CTGF in colonic SMC. Treatment of CD rats with anti-CTGF antibody FG-3149 reduced fibrosis and collagen content in both sites P and I and exhibited consistent trends towards normalizing expression of collagen mRNAs. In conclusion, our studies suggest that mechanical stress, by up-regulating pro-fibrotic mediators i.e. CTGF, may play a critical role in fibrosis in CD.
PubMed: 38954823
DOI: 10.1152/ajpgi.00123.2024 -
Bioconjugate Chemistry Jul 2024Fibroblast activation protein (FAP) has recently gained significant attention as a promising tumor biomarker for both diagnosis and therapeutic applications. A series of...
Fibroblast activation protein (FAP) has recently gained significant attention as a promising tumor biomarker for both diagnosis and therapeutic applications. A series of radiopharmaceuticals based on fibroblast activation protein inhibitors (FAPIs) have been developed and translated into the clinic. Though some of them such as radiolabeled FAPI-04 probes have achieved favorable in vivo imaging performance, further improvement is still highly desired for obtaining radiopharmaceuticals with a high theranostics potential. In this study, we innovatively designed an FAPI ligand SMIC-3002 by changing the core quinoline motif of FAPI-04 to the quinolinium scaffold. The engineered molecule was further radiolabeled with Ga to generate a positron emission tomography (PET) probe, [Ga]Ga-SMIC-3002, which was then evaluated in vitro and in vivo. [Ga]Ga-SMIC-3002 demonstrated high in vitro stability, nanomolar affinity for FAP (8 nM for protein, 23 nM for U87MG cells), and specific uptake in FAP-expressing tumors, with a tumor/muscle ratio of 19.1 and a tumor uptake of 1.48 ± 0.03 ID/g% at 0.5 h in U87MG tumor-bearing mice. In summary, the quinolinium scaffold can be successfully used for the development of the FAP-targeted tracer. [Ga]Ga-SMIC-3002 not only shows high potential for clinical translation but also offers insights into designing a new generation of FAPI tracers.
PubMed: 38954733
DOI: 10.1021/acs.bioconjchem.4c00214 -
PloS One 2024Bicuspid aortic valves (BAV) are frequently associated with ascending aortic aneurysms. The etiology is incompletely understood, but genetic factors, in addition to flow...
BACKGROUND
Bicuspid aortic valves (BAV) are frequently associated with ascending aortic aneurysms. The etiology is incompletely understood, but genetic factors, in addition to flow perturbations, are likely involved. Since loss of contractility and elaboration of extracellular matrix in the vessel wall are features of BAV-associated aortopathy, phenotypic modulation of smooth muscle cells (SMCs) may play a role.
METHODS
Ascending aortic tissue was collected intra-operatively from 25 individuals with normal (i.e., tricuspid) aortic valves (TAV) and from 25 individuals with BAVs. For both TAV and BAV, 10 patients had non-dilated (ND) and 15 patients had dilated (D) aortas. SMCs were isolated and cultured from a subset of patients from each group. Aortic tissue and SMCs were fluorescently immunolabeled for SMC phenotypic markers (i.e., alpha-smooth muscle actin (ASMA, contractile), vimentin (synthetic) and p16INK4a and p21Cip1 (senescence). SMCs were also analyzed for replicative senescence in culture.
RESULTS
In normal-sized and dilated BAV aortas, SMCs switched from the contractile state to either synthetic or senescent phenotypes, as observed by loss of ASMA (ND: P = 0.001, D: P = 0.002) and associated increases in vimentin (ND: P = 0.03, D: P = 0.004) or p16/p21 (ND: P = 0.03, D: P<0.0001) compared to TAV. Dilatation of the aorta exacerbated SMC phenotypic switching in both BAV and TAV aortas (all P<0.05). In SMCs cultured from normal and dilated aortas, those isolated from BAV reached replicative senescence faster than those from TAV aortas (all P = 0.02). Furthermore, there was a stark inverse correlation between ASMA and cell passage number in BAV SMCs (ND: P = 0.0006, D: P = 0.01), but not in TAV SMCs (ND: P = 0.93, D: P = 0.20).
CONCLUSIONS
The findings of this study provide direct evidence from cell culture studies implying that SMCs switch from the contractile state to either synthetic or senescent phenotypes in the non-dilated BAV aorta. In cultured SMCs from both non-dilated and dilated aortas, we found that this process may precede dilatation and accompany aneurysm development in BAV. Our findings suggest that therapeutically targeting SMC phenotypic modulation in BAV patients may be a viable option to prevent or delay ascending aortic aneurysm formation.
Topics: Humans; Aortic Valve; Bicuspid Aortic Valve Disease; Myocytes, Smooth Muscle; Heart Valve Diseases; Aorta; Male; Middle Aged; Phenotype; Female; Dilatation, Pathologic; Adult; Cellular Senescence; Cells, Cultured; Aged; Actins; Aortic Aneurysm; Vimentin
PubMed: 38954721
DOI: 10.1371/journal.pone.0306515 -
JCI Insight Jul 2024Pulmonary disorders impact 40% to 80% of individuals with obesity. Respiratory muscle dysfunction is linked to these conditions; however, its pathophysiology remains...
Pulmonary disorders impact 40% to 80% of individuals with obesity. Respiratory muscle dysfunction is linked to these conditions; however, its pathophysiology remains largely undefined. Mice subjected to diet-induced obesity (DIO) develop diaphragmatic weakness. Increased intra-diaphragmatic adiposity and extracellular matrix (ECM) content correlate with reductions in contractile force. Thrombospondin-1 (THBS1) is an obesity-associated matricellular protein linked with muscular damage in genetic myopathies. THBS1 induces proliferation of fibro-adipogenic progenitors (FAPs) - mesenchymal cells that differentiate into adipocytes and fibroblasts. We hypothesized that THBS1 drives FAP-mediated diaphragm remodeling and contractile dysfunction in DIO. We tested this by comparing the effects of dietary challenge on diaphragms of wild-type (WT) and Thbs1 knockout (Thbs1-/-) mice. Bulk and single-cell transcriptomics demonstrated DIO-induced stromal expansion in WT diaphragms. Diaphragm FAPs displayed upregulation of ECM and TGF β-related expression signatures and augmentation of a Thy1-expressing sub-population previously linked to type 2 diabetes. Despite similar weight gain, Thbs1-/- mice were protected from these transcriptomic changes and from obesity-induced increases in diaphragm adiposity and ECM deposition. Unlike WT controls, Thbs1-/- diaphragms maintained normal contractile force and motion after DIO challenge. These findings establish THBS1 as a necessary mediator of diaphragm stromal remodeling and contractile dysfunction in overnutrition and a potential therapeutic target in obesity-associated respiratory dysfunction.
PubMed: 38954467
DOI: 10.1172/jci.insight.175047 -
Annals of Surgical Oncology Jul 2024Because of to the removal of subclassification of papillary renal cell carcinoma (pRCC), the survival prognostification of localized pRCC after surgical treatment became...
BACKGROUND
Because of to the removal of subclassification of papillary renal cell carcinoma (pRCC), the survival prognostification of localized pRCC after surgical treatment became inadequate. Sarcopenia was widely evaluated and proved to be a predictive factor for prognosis in RCC patients. Therefore, we comprehensively investigated the survival prediction of the body composition parameters for localized pRCC.
METHODS
Patients pathologically diagnosed with pRCC between February 2012 and February 2022 in our center were enrolled. The body composition parameters, including skeletal muscle index (SMI), subcutaneous adipose tissue (SAT), and perirenal adipose tissue (PRAT), were measured by the images of preoperative computed tomography (CT). The primary outcome was set as progression-free survival (PFS), and the cutoff values of body composition parameters were calculated by using the Youden from receiver operating characteristic curve (ROC) curves. Univariate and multivariate Cox proportional regression analyses were performed to explore independent risk factors for survival prediction. Then, significant factors were used to construct a prognostic nomogram. The performance of the nomogram was evaluated by Harrell's C-index, calibration curves and time-dependent ROC curves.
RESULTS
A total of 105 patients were enrolled for analysis. With a median follow-up time of 30.48 months, 25 (23.81%) patients experienced cancer progression. The percentage of sarcopenia was 74.29%. Univariate Cox analysis identified that gender, PRAT, SAT, skeletal muscle (SM), sarcopenia, surgical technique, and tumor diameter were associated with progression. Further multivariate analysis showed that sarcopenia (hazard ratio [HR] 0.15, 95% confidence interval [CI] 0.03-0.66), SAT (HR 6.36, 95% CI 2.39-16.93), PRAT (HR 4.66, 95% CI 1.77-12.27), tumor diameter (HR 0.35, 95% CI 0.14-0.86), and surgical technique (HR 2.85, 95% CI 1.06-7.64) were independent risk factors for cancer progression. Then, a prognostic nomogram based on independent risk factors was constructed and the C-index for progression prediction was 0.831 (95% CI 0.761-0.901), representing a reasonable discrimination, the calibration curves, and the time-dependent ROC curves verified the good performance of the nomogram.
CONCLUSIONS
A prognostic nomogram, including sarcopenia, SAT, PRAT, tumor diameter, and surgical technique, was constructed to calculate the probability of progression for localized pRCC patients and needs further external validation for clinical use in the future.
PubMed: 38954088
DOI: 10.1245/s10434-024-15666-2 -
Wiener Klinische Wochenschrift Jul 2024Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematologic disorder characterized by a loss of glycosyl-phosphatidyl-inositol-linked (GPI) proteins on various...
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematologic disorder characterized by a loss of glycosyl-phosphatidyl-inositol-linked (GPI) proteins on various hematopoietic cells. Some GPI proteins are involved in the regulation of the complement system, and their absence renders erythrocytes susceptible to complement-mediated lysis. Current standard of care in PNH is to block the complement system at the level of C5 using ravulizumab or eculizumab; however, some patients with PNH may develop extravascular hemolysis (EVH) during treatment with C5 inhibitors. The proximal complement inhibitor iptacopan has recently been shown to be efficacious in patients with PNH. This article reports on a 43-year-old female patient with PNH who was successfully treated with iptacopan. The patient had received ravulizumab for several years and developed a clinically relevant EVH. After obtaining informed consent, the patient received oral iptacopan 200 mg twice daily and ravulizumab was discontinued. Over the next few weeks hemoglobin levels and reticulocyte counts normalized. The patient reported mild flushes with erythema, chills, and mild muscle pain, all of which resolved during follow-up. No breakthrough hemolysis occurred, and no severe adverse events were recorded.
PubMed: 38954058
DOI: 10.1007/s00508-024-02390-w -
Epilepsia Jul 2024DYNC1H1 variants are involved on a disease spectrum from neuromuscular disorders to neurodevelopmental disorders. DYNC1H1-related epilepsy has been reported in small...
OBJECTIVE
DYNC1H1 variants are involved on a disease spectrum from neuromuscular disorders to neurodevelopmental disorders. DYNC1H1-related epilepsy has been reported in small cohorts. We dissect the electroclinical features of 34 patients harboring de novo DYNC1H1 pathogenic variants, identify subphenotypes on the DYNC1H1-related epilepsy spectrum, and compare the genotype-phenotype correlations observed in our cohort with the literature.
METHODS
Patients harboring de novo DYNC1H1 pathogenic variants were recruited through international collaborations. Clinical data were retrospectively collected. Latent class analysis was performed to identify subphenotypes. Multivariable binary logistic regression analysis was applied to investigate the association with DYNC1H1 protein domains.
RESULTS
DYNC1H1-related epilepsy presented with infantile epileptic spasms syndrome (IESS) in 17 subjects (50%), and in 25% of these individuals the epileptic phenotype evolved into Lennox-Gastaut syndrome (LGS). In 12 patients (35%), focal onset epilepsy was defined. In two patients, the epileptic phenotype consisted of generalized myoclonic epilepsy, with a progressive phenotype in one individual harboring a frameshift variant. In approximately 60% of our cohort, seizures were drug-resistant. Malformations of cortical development were noticed in 79% of our patients, mostly on the lissencephaly-pachygyria spectrum, particularly with posterior predominance in a half of them. Midline and infratentorial abnormalities were additionally reported in 45% and 27% of subjects. We have identified three main classes of subphenotypes on the DYNC1H1-related epilepsy spectrum.
SIGNIFICANCE
We propose a classification in which pathogenic de novo DYNC1H1 variants feature drug-resistant IESS in half of cases with potential evolution to LGS (Class 1), developmental and epileptic encephalopathy other than IESS and LGS (Class 2), or less severe focal or genetic generalized epilepsy including a progressive phenotype (Class 3). We observed an association between stalk domain variants and Class 1 phenotypes. The variants p.Arg309His and p.Arg1962His were common and associated with Class 1 subphenotype in our cohort. These findings may aid genetic counseling of patients with DYNC1H1-related epilepsy.
PubMed: 38953796
DOI: 10.1111/epi.18054 -
General Physiology and Biophysics Jul 2024Vitiligo is featured by manifestation of white maculae and primarily results from oxidative stress. Sphingosine kinase-1 (SPHK1) participates in oxidative stress. This...
Vitiligo is featured by manifestation of white maculae and primarily results from oxidative stress. Sphingosine kinase-1 (SPHK1) participates in oxidative stress. This paper was devised to explore the role of SPHK1 in vitiligo and to disclose the mechanism. PIG1 cell viability was appraised utilizing cell counting kit-8 assay while Western blot detected SPHK1 and four and a half LIM domains 2 (FHL2). The transduction efficacy of small interfering RNA (siRNA)-SPHK1, siRNA-FHL2 and pcDNA3.1 plasmid overexpressing FHL2 (Ov-FHL2) was checked using Western blot. Flow cytometry detected cell apoptotisis. Western blot detected mitochondrial cytochrome c (Mit-Cyt-c) and cytosolic cytochrome c (Cyto-Cyt-c). Dichloro-dihydro-fluorescein diacetate (DCFH-DA) detected reactive oxygen species (ROS) activity while oxidative stress markers were evaluated using corresponding assay kits. SPHK1 expression was discovered to be increased in hydrogen peroxide (H2O2)-challenged PIG1 cells and SPHK1 interference alleviated H2O2-challenged viability damage, apoptosis, oxidative stress and FHL2 expression in PIG1 cells. FHL2 depletion could suppress viability damage, apoptosis and oxidative stress in H2O2-challenged PIG1 cells. Rescue experiments demonstrated that the suppressive impacts of SPHK1 deficiency on PIG1 cell viability, apoptosis and oxidative stress induced by H2O2 were offset by FHL2 overexpression. Collectively, SPHK1 knockdown protected against vitiligo via the regulation of FHL2.
Topics: Oxidative Stress; Phosphotransferases (Alcohol Group Acceptor); Hydrogen Peroxide; LIM-Homeodomain Proteins; Humans; Melanocytes; Cell Survival; Apoptosis; Transcription Factors; Muscle Proteins; Cell Line
PubMed: 38953574
DOI: 10.4149/gpb_2024011 -
Small (Weinheim An Der Bergstrasse,... Jul 2024Abdominal aortic aneurysm (AAA) represents a critical cardiovascular condition characterized by localized dilation of the abdominal aorta, carrying a significant risk of...
Abdominal aortic aneurysm (AAA) represents a critical cardiovascular condition characterized by localized dilation of the abdominal aorta, carrying a significant risk of rupture and mortality. Current treatment options are limited, necessitating novel therapeutic approaches. This study investigates the potential of a pioneering nanodrug delivery system, RAP@PFB, in mitigating AAA progression. RAP@PFB integrates pentagalloyl glucose (PGG) and rapamycin (RAP) within a metal-organic-framework (MOF) structure through a facile assembly process, ensuring remarkable drug loading capacity and colloidal stability. The synergistic effects of PGG, a polyphenolic antioxidant, and RAP, an mTOR inhibitor, collectively regulate key players in AAA pathogenesis, such as macrophages and smooth muscle cells (SMCs). In macrophages, RAP@PFB efficiently scavenges various free radicals, suppresses inflammation, and promotes M1-to-M2 phenotype repolarization. In SMCs, it inhibits apoptosis and calcification, thereby stabilizing the extracellular matrix and reducing the risk of AAA rupture. Administered intravenously, RAP@PFB exhibits effective accumulation at the AAA site, demonstrating robust efficacy in reducing AAA progression through multiple mechanisms. Moreover, RAP@PFB demonstrates favorable biosafety profiles, supporting its potential translation into clinical applications for AAA therapy.
PubMed: 38953313
DOI: 10.1002/smll.202402141