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Keywords = electron microscopy, cholesterol homeostasis

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18 pages, 3190 KB  
Article
Osteoprotective Effect of the Phytonutraceutical Ormona® on Ovariectomy-Induced Osteoporosis in Wistar Rats
by Aline Lopes do Nascimento, Gabriel da Costa Furtado, Vinicius Maciel Vilhena, Helison de Oliveira Carvalho, Priscila Faimann Sales, Alessandra Ohana Nery Barcellos, Kaio Coutinho de Maria, Francinaldo Sarges Braga, Heitor Ribeiro da Silva, Roberto Messias Bezerra and José Carlos Tavares Carvalho
Nutraceuticals 2024, 4(2), 147-164; https://doi.org/10.3390/nutraceuticals4020010 - 22 Mar 2024
Cited by 4 | Viewed by 5198
Abstract
The phytonutraceutical Ormona® is a product composed of purified oil of Bixa orellana Linné, dry extract of Myrciaria dubia McVaugh, dry extract of Trifolium pratense L., and dry extract of Euterpe oleracea Mart. obtained using Evolve® technology. This study evaluated the [...] Read more.
The phytonutraceutical Ormona® is a product composed of purified oil of Bixa orellana Linné, dry extract of Myrciaria dubia McVaugh, dry extract of Trifolium pratense L., and dry extract of Euterpe oleracea Mart. obtained using Evolve® technology. This study evaluated the effects of Ormona® on Wistar rats affected by ovariectomy-induced osteoporosis. Pre-treatment was conducted for 15 days before surgery and continued for a further 45 days after the surgical procedure. The experimental design consisted of five groups (n = 5): OVW: treated with distilled water (1 mL/kg, p.o); ADS: alendronate sodium (4 mg/kg p.o); EST: conjugated estrogen (2 µg/kg, p.o); ORM: Ormona® (20 mg/kg, p.o); ORM + EST: Ormona® (20 mg/kg, p.o) + conjugated estrogen (2 µg/kg, p.o). Biochemical and hormonal parameters of bone histopathology and trabecular and femoral diaphysis size were evaluated through scanning electron microscopy (SEM) and bone calcium quantification by atomic absorption spectrophotometry. The results show that ovariectomy caused bone alterations such as loss of femoral microarchitecture, decreased bone homeostasis parameters, and changes in the lipid profile. Estrogen supplementation reduced parameters such as cholesterol, LDL, and Ca2+ concentration. However, Ormona® showed higher serum estradiol levels (p < 0.01), effects on the lipid profile, including parameters that estrogen replacement and alendronate sodium did not affect, with an increase in HDL, and positive modulation of bone metabolism, increasing osteocytes and the presence of osteoblasts. Ormona®, therefore, produced better results than the groups treated with estrogen and alendronate sodium. Full article
(This article belongs to the Special Issue Nutraceuticals and Their Anti-inflammatory Effects)
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25 pages, 15126 KB  
Article
Abnormal Cholesterol Metabolism and Lysosomal Dysfunction Induce Age-Related Hearing Loss by Inhibiting mTORC1-TFEB-Dependent Autophagy
by Yun Yeong Lee, Jungho Ha, Young Sun Kim, Sivasubramanian Ramani, Siung Sung, Eun Sol Gil, Oak-Sung Choo, Jeong Hun Jang and Yun-Hoon Choung
Int. J. Mol. Sci. 2023, 24(24), 17513; https://doi.org/10.3390/ijms242417513 - 15 Dec 2023
Cited by 18 | Viewed by 5323
Abstract
Cholesterol is a risk factor for age-related hearing loss (ARHL). However, the effect of cholesterol on the organ of Corti during the onset of ARHL is unclear. We established a mouse model for the ARHL group (24 months, n = 12) and a [...] Read more.
Cholesterol is a risk factor for age-related hearing loss (ARHL). However, the effect of cholesterol on the organ of Corti during the onset of ARHL is unclear. We established a mouse model for the ARHL group (24 months, n = 12) and a young group (6 months, n = 12). Auditory thresholds were measured in both groups using auditory brainstem response (ABR) at frequencies of 8, 16, and 32 kHz. Subsequently, mice were sacrificed and subjected to histological analyses, including transmission electron microscopy (TEM), H&E, Sudan Black B (SBB), and Filipin staining, as well as biochemical assays such as IHC, enzymatic analysis, and immunoblotting. Additionally, mRNA extracted from both young and aged cochlea underwent RNA sequencing. To identify the mechanism, in vitro studies utilizing HEI-OC1 cells were also performed. RNA sequencing showed a positive correlation with increased expression of genes related to metabolic diseases, cholesterol homeostasis, and target of rapamycin complex 1 (mTORC1) signaling in the ARHL group as compared to the younger group. In addition, ARHL tissues exhibited increased cholesterol and lipofuscin aggregates in the organ of Corti, lateral walls, and spiral ganglion neurons. Autophagic flux was inhibited by the accumulation of damaged lysosomes and autolysosomes. Subsequently, we observed a decrease in the level of transcription factor EB (TFEB) protein, which regulates lysosomal biosynthesis and autophagy, together with increased mTORC1 activity in ARHL tissues. These changes in TFEB and mTORC1 expression were observed in a cholesterol-dependent manner. Treatment of ARHL mice with atorvastatin, a cholesterol synthesis inhibitor, delayed hearing loss by reducing the cholesterol level and maintaining lysosomal function and autophagy by inhibiting mTORC1 and activating TFEB. The above findings were confirmed using stress-induced premature senescent House Ear Institute organ of Corti 1 (HEI-OC1) cells. The findings implicate cholesterol in the pathogenesis of ARHL. We propose that atorvastatin could prevent ARHL by maintaining lysosomal function and autophagy by inhibiting mTORC1 and activating TFEB during the aging process. Full article
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31 pages, 8191 KB  
Article
Multi-Omics Analysis of Circulating Exosomes in Adherent Long-Term Treated OSA Patients
by Abdelnaby Khalyfa, Jose M. Marin, David Sanz-Rubio, Zhen Lyu, Trupti Joshi and David Gozal
Int. J. Mol. Sci. 2023, 24(22), 16074; https://doi.org/10.3390/ijms242216074 - 8 Nov 2023
Cited by 18 | Viewed by 4944
Abstract
Obstructive sleep apnea (OSA) is a highly prevalent chronic disease affecting nearly a billion people globally and increasing the risk of multi-organ morbidity and overall mortality. However, the mechanisms underlying such adverse outcomes remain incompletely delineated. Extracellular vesicles (exosomes) are secreted by most [...] Read more.
Obstructive sleep apnea (OSA) is a highly prevalent chronic disease affecting nearly a billion people globally and increasing the risk of multi-organ morbidity and overall mortality. However, the mechanisms underlying such adverse outcomes remain incompletely delineated. Extracellular vesicles (exosomes) are secreted by most cells, are involved in both proximal and long-distance intercellular communication, and contribute toward homeostasis under physiological conditions. A multi-omics integrative assessment of plasma-derived exosomes from adult OSA patients prior to and after 1-year adherent CPAP treatment is lacking. We conducted multi-omic integrative assessments of plasma-derived exosomes from adult OSA patients prior to and following 1-year adherent CPAP treatment to identify potential specific disease candidates. Fasting morning plasma exosomes isolated from 12 adult patients with polysomnographically-diagnosed OSA were analyzed before and after 12 months of adherent CPAP therapy (mean ≥ 6 h/night) (OSAT). Exosomes were characterized by flow cytometry, transmission electron microscopy, and nanoparticle tracking analysis. Endothelial cell barrier integrity, wound healing, and tube formation were also performed. Multi-omics analysis for exosome cargos was integrated. Exosomes derived from OSAT improved endothelial permeability and dysfunction as well as significant improvement in tube formation compared with OSA. Multi-omic approaches for OSA circulating exosomes included lipidomic, proteomic, and small RNA (miRNAs) assessments. We found 30 differentially expressed proteins (DEPs), 72 lipids (DELs), and 13 miRNAs (DEMs). We found that the cholesterol metabolism (has04979) pathway is associated with lipid classes in OSA patients. Among the 12 subjects of OSA and OSAT, seven subjects had complete comprehensive exosome cargo information including lipids, proteins, and miRNAs. Multi-omic approaches identify potential signature biomarkers in plasma exosomes that are responsive to adherent OSA treatment. These differentially expressed molecules may also play a mechanistic role in OSA-induced morbidities and their reversibility. Our data suggest that a multi-omic integrative approach might be useful in understanding how exosomes function, their origin, and their potential clinical relevance, all of which merit future exploration in the context of relevant phenotypic variance. Developing an integrated molecular classification should lead to improved diagnostic classification, risk stratification, and patient management of OSA by assigning molecular disease-specific therapies. Full article
(This article belongs to the Special Issue Exosomes 2.0)
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22 pages, 6517 KB  
Article
The Interplay between Retinal Pathways of Cholesterol Output and Its Effects on Mouse Retina
by Alexey M. Petrov, Artem A. Astafev, Natalia Mast, Aicha Saadane, Nicole El-Darzi and Irina A. Pikuleva
Biomolecules 2019, 9(12), 867; https://doi.org/10.3390/biom9120867 - 12 Dec 2019
Cited by 13 | Viewed by 6087
Abstract
In mammalian retina, cholesterol excess is mainly metabolized to oxysterols by cytochromes P450 27A1 (CYP27A1) and 46A1 (CYP46A1) or removed on lipoprotein particles containing apolipoprotein E (APOE). In contrast, esterification by sterol-O-acyltransferase 1 (SOAT) plays only a minor role in this process. Accordingly, [...] Read more.
In mammalian retina, cholesterol excess is mainly metabolized to oxysterols by cytochromes P450 27A1 (CYP27A1) and 46A1 (CYP46A1) or removed on lipoprotein particles containing apolipoprotein E (APOE). In contrast, esterification by sterol-O-acyltransferase 1 (SOAT) plays only a minor role in this process. Accordingly, retinal cholesterol levels are unchanged in Soat1−/− mice but are increased in Cyp27a1−/−Cyp46a1−/− and Apoe−/− mice. Herein, we characterized Cyp27a1−/−Cyp46a1−/−Soat1−/− and Cyp27a1−/−Cyp46a1−/−Apoe−/− mice. In the former, retinal cholesterol levels, anatomical gross structure, and vasculature were normal, yet the electroretinographic responses were impaired. Conversely, in Cyp27a1−/−Cyp46a1−/−Apoe−/− mice, retinal cholesterol levels were increased while anatomical structure and vasculature were unaffected with only male mice showing a decrease in electroretinographic responses. Sterol profiling, qRT-PCR, proteomics, and transmission electron microscopy mapped potential compensatory mechanisms in the Cyp27a1−/−Cyp46a1−/−Soat1−/− and Cyp27a1−/−Cyp46a1−/−Apoe−/− retina. These included decreased cholesterol biosynthesis along with enhanced formation of intra- and extracellular vesicles, possibly a reserve mechanism for lowering retinal cholesterol. In addition, there was altered abundance of proteins in Cyp27a1−/−Cyp46a1−/−Soat1−/− mice that can affect photoreceptor function, survival, and retinal energy homeostasis (glucose and fatty acid metabolism). Therefore, the levels of retinal cholesterol do not seem to predict retinal abnormalities, and it is rather the network of compensatory mechanisms that appears to determine retinal phenotype. Full article
(This article belongs to the Section Cellular Biochemistry)
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18 pages, 2724 KB  
Review
Current Challenges in Understanding the Cellular and Molecular Mechanisms in Niemann–Pick Disease Type C1
by Anja U. Bräuer, Angela Kuhla, Carsten Holzmann, Andreas Wree and Martin Witt
Int. J. Mol. Sci. 2019, 20(18), 4392; https://doi.org/10.3390/ijms20184392 - 6 Sep 2019
Cited by 37 | Viewed by 7095
Abstract
Rare diseases are a heterogeneous group of very different clinical syndromes. Their most common causes are defects in the hereditary material, and they can therefore be passed on to descendants. Rare diseases become manifest in almost all organs and often have a systemic [...] Read more.
Rare diseases are a heterogeneous group of very different clinical syndromes. Their most common causes are defects in the hereditary material, and they can therefore be passed on to descendants. Rare diseases become manifest in almost all organs and often have a systemic expressivity, i.e., they affect several organs simultaneously. An effective causal therapy is often not available and can only be developed when the underlying causes of the disease are understood. In this review, we focus on Niemann–Pick disease type C1 (NPC1), which is a rare lipid-storage disorder. Lipids, in particular phospholipids, are a major component of the cell membrane and play important roles in cellular functions, such as extracellular receptor signaling, intracellular second messengers and cellular pressure regulation. An excessive storage of fats, as seen in NPC1, can cause permanent damage to cells and tissues in the brain and peripheral nervous system, but also in other parts of the body. Here, we summarize the impact of NPC1 pathology on several organ systems, as revealed in experimental animal models and humans, and give an overview of current available treatment options. Full article
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