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1.
Commun Biol ; 7(1): 539, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714886

RESUMO

Intervertebral disc degeneration (IDD) is a highly prevalent musculoskeletal disorder affecting millions of adults worldwide, but a poor understanding of its pathogenesis has limited the effectiveness of therapy. In the current study, we integrated untargeted LC/MS metabolomics and magnetic resonance spectroscopy data to investigate metabolic profile alterations during IDD. Combined with validation via a large-cohort analysis, we found excessive lipid droplet accumulation in the nucleus pulposus cells of advanced-stage IDD samples. We also found abnormal palmitic acid (PA) accumulation in IDD nucleus pulposus cells, and PA exposure resulted in lipid droplet accumulation and cell senescence in an endoplasmic reticulum stress-dependent manner. Complementary transcriptome and proteome profiles enabled us to identify solute carrier transporter (SLC) 43A3 involvement in the regulation of the intracellular PA level. SLC43A3 was expressed at low levels and negatively correlated with intracellular lipid content in IDD nucleus pulposus cells. Overexpression of SLC43A3 significantly alleviated PA-induced endoplasmic reticulum stress, lipid droplet accumulation and cell senescence by inhibiting PA uptake. This work provides novel integration analysis-based insight into the metabolic profile alterations in IDD and further reveals new therapeutic targets for IDD treatment.


Assuntos
Senescência Celular , Estresse do Retículo Endoplasmático , Degeneração do Disco Intervertebral , Gotículas Lipídicas , Núcleo Pulposo , Ácido Palmítico , Núcleo Pulposo/metabolismo , Núcleo Pulposo/efeitos dos fármacos , Núcleo Pulposo/patologia , Núcleo Pulposo/citologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ácido Palmítico/metabolismo , Ácido Palmítico/farmacologia , Senescência Celular/efeitos dos fármacos , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/patologia , Humanos , Gotículas Lipídicas/metabolismo , Masculino , Feminino , Adulto , Pessoa de Meia-Idade
2.
J Agric Food Chem ; 72(19): 11268-11277, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38695399

RESUMO

Buttermilk is a potential material for the production of a milk fat globule membrane (MFGM) and can be mainly classified into two types: whole cream buttermilk and cheese whey cream buttermilk (WCB). Due to the high casein micelle content of whole cream buttermilk, the removal of casein micelles to improve the purity of MFGM materials is always required. This study investigated the effects of rennet and acid coagulation on the lipid profile of buttermilk rennet-coagulated whey (BRW) and buttermilk acid-coagulated whey (BAW) and compared them with WCB. BRW has significantly higher phospholipids (PLs) and ganglioside contents than BAW and WCB. The abundance of arachidonic acid (ARA)- and eicosapentaenoic acid (EPA)-structured PLs was higher in WCB, while docosahexaenoic acid (DHA)-structured PLs were higher in BRW, indicating that BRW and WCB intake might have a greater effect on improving cardiovascular conditions and neurodevelopment. WCB and BRW had a higher abundance of plasmanyl PL and plasmalogen PL, respectively. Phosphatidylcholine (PC) (28:1), LPE (20:5), and PC (26:0) are characteristic lipids among BRW, BAW, and WCB, and they can be used to distinguish MFGM-enriched whey from different sources.


Assuntos
Leitelho , Queijo , Cabras , Lipidômica , Soro do Leite , Animais , Leitelho/análise , Queijo/análise , Soro do Leite/química , Fosfolipídeos/análise , Fosfolipídeos/química , Glicolipídeos/química , Leite/química , Gotículas Lipídicas/química , Glicoproteínas/química , Glicoproteínas/análise , Lipídeos/química , Lipídeos/análise
3.
Nat Commun ; 15(1): 2869, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38693144

RESUMO

Only ~20% of heavy drinkers develop alcohol cirrhosis (AC). While differences in metabolism, inflammation, signaling, microbiome signatures and genetic variations have been tied to the pathogenesis of AC, the key underlying mechanisms for this interindividual variability, remain to be fully elucidated. Induced pluripotent stem cell-derived hepatocytes (iHLCs) from patients with AC and healthy controls differ transcriptomically, bioenergetically and histologically. They include a greater number of lipid droplets (LDs) and LD-associated mitochondria compared to control cells. These pre-pathologic indicators are effectively reversed by Aramchol, an inhibitor of stearoyl-CoA desaturase. Bioenergetically, AC iHLCs have lower spare capacity, slower ATP production and their mitochondrial fuel flexibility towards fatty acids and glutamate is weakened. MARC1 and PNPLA3, genes implicated by GWAS in alcohol cirrhosis, show to correlate with lipid droplet-associated and mitochondria-mediated oxidative damage in AC iHLCs. Knockdown of PNPLA3 expression exacerbates mitochondrial deficits and leads to lipid droplets alterations. These findings suggest that differences in mitochondrial bioenergetics and lipid droplet formation are intrinsic to AC hepatocytes and can play a role in its pathogenesis.


Assuntos
Aciltransferases , Metabolismo Energético , Hepatócitos , Células-Tronco Pluripotentes Induzidas , Lipase , Gotículas Lipídicas , Cirrose Hepática Alcoólica , Mitocôndrias , Fosfolipases A2 Independentes de Cálcio , Humanos , Hepatócitos/metabolismo , Hepatócitos/patologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Gotículas Lipídicas/metabolismo , Cirrose Hepática Alcoólica/metabolismo , Cirrose Hepática Alcoólica/patologia , Cirrose Hepática Alcoólica/genética , Lipase/metabolismo , Lipase/genética , Mitocôndrias/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Feminino , Pessoa de Meia-Idade , Adulto , Estresse Oxidativo
4.
Nat Commun ; 15(1): 3767, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38704407

RESUMO

Tools for accessing and studying organelles remain underdeveloped. Here, we present a method by which giant organelle vesicles (GOVs) are generated by submitting cells to a hypotonic medium followed by plasma membrane breakage. By this means, GOVs ranging from 3 to over 10 µm become available for micromanipulation. GOVs are made from organelles such as the endoplasmic reticulum, endosomes, lysosomes and mitochondria, or in contact with one another such as giant mitochondria-associated ER membrane vesicles. We measure the mechanical properties of each organelle-derived GOV and find that they have distinct properties. In GOVs procured from Cos7 cells, for example, bending rigidities tend to increase from the endoplasmic reticulum to the plasma membrane. We also found that the mechanical properties of giant endoplasmic reticulum vesicles (GERVs) vary depending on their interactions with other organelles or the metabolic state of the cell. Lastly, we demonstrate GERVs' biochemical activity through their capacity to synthesize triglycerides and assemble lipid droplets. These findings underscore the potential of GOVs as valuable tools for studying the biophysics and biology of organelles.


Assuntos
Retículo Endoplasmático , Membranas Intracelulares , Animais , Chlorocebus aethiops , Células COS , Retículo Endoplasmático/metabolismo , Membranas Intracelulares/metabolismo , Membrana Celular/metabolismo , Mitocôndrias/metabolismo , Organelas/metabolismo , Gotículas Lipídicas/metabolismo , Triglicerídeos/metabolismo , Humanos , Lisossomos/metabolismo
5.
Nutrients ; 16(9)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38732501

RESUMO

Obesity can lead to excessive lipid accumulation in non-adipose tissues, such as the liver and skeletal muscles, leading to ectopic lipid deposition and damaging target organ function through lipotoxicity. FGF-21 is a key factor in regulating lipid metabolism, so we aim to explore whether FGF-21 is involved in improving ectopic lipid deposition. We observed the characteristics of ectopic lipid deposition in the liver and skeletal muscles of obesity-resistant mice, detected the expression of FGF-21 and perilipin, and found that obesity-resistant mice showed a decrease in ectopic lipid deposition in the liver and skeletal muscles and increased expression of FGF-21. After inhibiting the expression of FGF-21, a more severe lipid deposition in liver cells and skeletal muscle cells was found. The results indicate that inhibiting FGF-21 can exacerbate ectopic lipid deposition via regulating lipid droplet synthesis and decomposition, as well as free fatty acid translocation and oxidation. In conclusion, FGF-21 is involved in improving ectopic lipid deposition caused by obesity in the liver and skeletal muscles.


Assuntos
Fatores de Crescimento de Fibroblastos , Metabolismo dos Lipídeos , Fígado , Músculo Esquelético , Obesidade , Animais , Fatores de Crescimento de Fibroblastos/metabolismo , Músculo Esquelético/metabolismo , Fígado/metabolismo , Camundongos , Obesidade/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Perilipina-1/metabolismo , Gotículas Lipídicas/metabolismo
6.
Int J Biol Macromol ; 267(Pt 2): 131240, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38583827

RESUMO

Lipids are intimately related to the unique flavor and nutritional values of goat milk. MicroRNAs (miRNA) participate in the regulation of various biological functions, including the synthesis and degradation of lipids. Several studies have shown that miR-103 is involved in the regulation of lipid metabolism, however, the molecular mechanism by which miR-103 regulates lipid metabolism in goat mammary gland is poorly understood. In this study, miR-103 was knocked out in goat mammary epithelial cells (GMECs) by CRISPR/Cas9, and the accumulation of lipid droplets, triglycerides, and cholesterol in the cells was suppressed subsequently. Overexpression or knockdown of miR-103-5p and miR-103-3p in GMECs revealed that it was miR-103-5p that promoted lipid accumulation but not miR-103-3p. In addition, Pantothenate Kinase 3 (PANK3), the host gene of miR-103, and Phospholipid Scramblase 4 (PLSCR4) were identified as the target genes of miR-103-5p by dual fluorescein and miRNA pulldown. Furthermore, we identified that cellular lipid levels were negatively regulated by PANK3 and PLSCR4. Lastly, in miR-103 knockout GMECs, the knockdown of PANK and PLSCR4 rescued the lipid accumulation. These findings suggest that miR-103-5p promotes lipid accumulation by targeting PLSCR4 and the host gene PANK3 in GMECs, providing new insights for the regulation of goat milk lipids via miRNAs.


Assuntos
Células Epiteliais , Cabras , Metabolismo dos Lipídeos , Glândulas Mamárias Animais , MicroRNAs , Fosfotransferases (Aceptor do Grupo Álcool) , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Cabras/genética , Metabolismo dos Lipídeos/genética , Células Epiteliais/metabolismo , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/citologia , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Feminino , Proteínas de Transferência de Fosfolipídeos/genética , Proteínas de Transferência de Fosfolipídeos/metabolismo , Proteínas de Transferência de Fosfolipídeos/deficiência , Regulação para Cima/genética , Gotículas Lipídicas/metabolismo , Regulação da Expressão Gênica , Triglicerídeos/metabolismo
7.
Nat Commun ; 15(1): 3213, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615060

RESUMO

Oxidative stress-induced lipid accumulation is mediated by lipid droplets (LDs) homeostasis, which sequester vulnerable unsaturated triglycerides into LDs to prevent further peroxidation. Here we identify the upregulation of lipopolysaccharide-binding protein (LBP) and its trafficking through LDs as a mechanism for modulating LD homeostasis in response to oxidative stress. Our results suggest that LBP induces lipid accumulation by controlling lipid-redox homeostasis through its lipid-capture activity, sorting unsaturated triglycerides into LDs. N-acetyl-L-cysteine treatment reduces LBP-mediated triglycerides accumulation by phospholipid/triglycerides competition and Peroxiredoxin 4, a redox state sensor of LBP that regulates the shuttle of LBP from LDs. Furthermore, chronic stress upregulates LBP expression, leading to insulin resistance and obesity. Our findings contribute to the understanding of the role of LBP in regulating LD homeostasis and against cellular peroxidative injury. These insights could inform the development of redox-based therapies for alleviating oxidative stress-induced metabolic dysfunction.


Assuntos
Proteínas de Fase Aguda , Gotículas Lipídicas , Glicoproteínas de Membrana , Proteínas de Fase Aguda/metabolismo , Proteínas de Transporte/metabolismo , Homeostase , Gotículas Lipídicas/metabolismo , Lipopolissacarídeos/metabolismo , Glicoproteínas de Membrana/metabolismo , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Triglicerídeos
8.
Cell Rep ; 43(4): 114093, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38602875

RESUMO

The storage of fat within lipid droplets (LDs) of adipocytes is critical for whole-body health. Acute fatty acid (FA) uptake by differentiating adipocytes leads to the formation of at least two LD classes marked by distinct perilipins (PLINs). How this LD heterogeneity arises is an important yet unresolved cell biological problem. Here, we show that an unconventional integral membrane segment (iMS) targets the adipocyte specific LD surface factor PLIN1 to the endoplasmic reticulum (ER) and facilitates high-affinity binding to the first LD class. The other PLINs remain largely excluded from these LDs until FA influx recruits them to a second LD population. Preventing ER targeting turns PLIN1 into a soluble, cytoplasmic LD protein, reduces its LD affinity, and switches its LD class specificity. Conversely, moving the iMS to PLIN2 leads to ER insertion and formation of a separate LD class. Our results shed light on how differences in organelle targeting and disparities in lipid affinity of LD surface factors contribute to formation of LD heterogeneity.


Assuntos
Adipócitos , Diferenciação Celular , Retículo Endoplasmático , Gotículas Lipídicas , Gotículas Lipídicas/metabolismo , Adipócitos/metabolismo , Animais , Camundongos , Retículo Endoplasmático/metabolismo , Perilipinas/metabolismo , Humanos , Células 3T3-L1 , Ácidos Graxos/metabolismo , Perilipina-1/metabolismo , Perilipina-2/metabolismo
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124356, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38678840

RESUMO

Microenvironmental viscosity is a crucial parameter for biological systems, and its abnormal fluctuations are closely associated with various functional disorders and diseases. However, it is still important and urgent to develop improved near-infrared fluorescent probes for micro-viscosity with dual-organelle targeting properties, low background noise, and high sensitivity. Herein, two BODIPY-based small-molecule fluorescent probes were designed and synthesized, which were explored for their viscosity- and polarity-responsive properties, and were further applied to imaging sub-cellular viscosity in living cells. Interestingly, BSZ-Ph and BSZ-R displayed near-infrared fluorescence (more than 650 nm) and were sensitive to environmental viscosity and polarity due to the introduction of a benzothiazole at the 2-position and electron-rich aniline groups at the 5-position of the BODIPY core, respectively. The fluorescence intensity increased exponentially with the viscosity changes. Furthermore, the probe BSZ-Ph could successfully target lipid droplets and image cellular viscosity changes by treating lipopolysaccharides (LPS) and nystatin. Comparatively, the probe BSZ-R could successfully target the dual organelles of lipid droplets and lysosomes and image cellular viscosity changes by treating LPS and monensin. Therefore, in this work, we reported two new BODIPY-based near-infrared fluorescent probes, BSZ-Ph and BSZ-R, for cellular viscosity imaging, which could target lipid droplets and the dual organelles of lysosomes and lipid droplets, respectively. The study could provide a reference for the future development of fluorescent probes for viscosity in lipid droplets and lysosomes.


Assuntos
Compostos de Boro , Corantes Fluorescentes , Gotículas Lipídicas , Lisossomos , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Viscosidade , Lisossomos/metabolismo , Lisossomos/química , Gotículas Lipídicas/química , Gotículas Lipídicas/metabolismo , Compostos de Boro/química , Compostos de Boro/síntese química , Humanos , Animais , Camundongos , Células HeLa , Imagem Óptica
10.
Ultrason Sonochem ; 105: 106873, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38608436

RESUMO

Starting from the consideration of the structure of human milk fat globule (MFG), this study aimed to investigate the effects of ultrasonic treatment on milk fat globule membrane (MFGM) and soy lecithin (SL) complexes and their role in mimicking human MFG emulsions. Ultrasonic power significantly affected the structure of the MFGM-SL complex, further promoting the unfolding of the molecular structure of the protein, and then increased solubility and surface hydrophobicity. Furthermore, the microstructure of mimicking MFG emulsions without sonication was unevenly distributed, and the average droplet diameter was large. After ultrasonic treatment, the droplets of the emulsion were more uniformly dispersed, the particle size was smaller, and the emulsification properties and stability were improved to varying degrees. Especially when the ultrasonic power was 300 W, the mimicking MFG emulsion had the highest encapsulation rate and emulsion activity index and emulsion stability index were increased by 60.88 % and 117.74 %, respectively. From the microstructure, it was observed that the spherical droplets of the mimicking MFG emulsion after appropriate ultrasonic treatment remain well separated without obvious flocculation. This study can provide a reference for the screening of milk fat globules mimicking membrane materials and the further utilization and development of ultrasound in infant formula.


Assuntos
Emulsões , Glicolipídeos , Glicoproteínas , Lecitinas , Gotículas Lipídicas , Lecitinas/química , Glicolipídeos/química , Gotículas Lipídicas/química , Glicoproteínas/química , Glicoproteínas/análise , Humanos , Glycine max/química , Leite Humano/química , Fenômenos Químicos , Tamanho da Partícula , Ondas Ultrassônicas , Sonicação
11.
Nutrients ; 16(7)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38612988

RESUMO

The goblet cells of the gastrointestinal tract (GIT) produce glycoproteins called mucins that form a protective barrier from digestive contents and external stimuli. Recent evidence suggests that the milk fat globule membrane (MFGM) and its milk phospholipid component (MPL) can benefit the GIT through improving barrier function. Our objective was to compare the effects of two digested MFGM ingredients with or without dextran sodium sulfate (DSS)-induced barrier stress on mucin proteins. Co-cultured Caco-2/HT29-MTX intestinal cells were treated with in vitro digests of 2%, 5%, and 10% (w/v) MFGM or MPL alone for 6 h or followed by challenge with 2.5% DSS (6 h). Transepithelial electrical resistance and fluorescein isothiocyanate (FITC)-dextran (FD4) permeability measurements were used to measure changes in barrier integrity. Mucin characterization was performed using a combination of slot blotting techniques for secreted (MUC5AC, MUC2) and transmembrane (MUC3A, MUC1) mucins, scanning electron microscopy (SEM), and periodic acid Schiff (PAS)/Alcian blue staining. Digested MFGM and MPL prevented a DSS-induced reduction in secreted mucins, which corresponded to the prevention of DSS-induced increases in FD4 permeability. SEM and PAS/Alcian blue staining showed similar visual trends for secreted mucin production. A predictive bioinformatic approach was also used to identify potential KEGG pathways involved in MFGM-mediated mucosal maintenance under colitis conditions. This preliminary in silico evidence, combined with our in vitro findings, suggests the role of MFGM in inducing repair and maintenance of the mucosal barrier.


Assuntos
Dextranos , Fluoresceína-5-Isotiocianato/análogos & derivados , Glicolipídeos , Glicoproteínas , Gotículas Lipídicas , Humanos , Células CACO-2 , Azul Alciano , Glicoproteínas/farmacologia , Células Epiteliais , Mucinas
12.
Commun Biol ; 7(1): 458, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622242

RESUMO

Differentiation of adipose progenitor cells into mature adipocytes entails a dramatic reorganization of the cellular architecture to accommodate lipid storage into cytoplasmic lipid droplets. Lipid droplets occupy most of the adipocyte volume, compressing the nucleus beneath the plasma membrane. How this cellular remodeling affects sub-nuclear structure, including size and number of nucleoli, remains unclear. We describe the morphological remodeling of the nucleus and the nucleolus during in vitro adipogenic differentiation of primary human adipose stem cells. We find that cell cycle arrest elicits a remodeling of nucleolar structure which correlates with a decrease in protein synthesis. Strikingly, triggering cytoskeletal rearrangements mimics the nucleolar remodeling observed during adipogenesis. Our results point to nucleolar remodeling as an active, mechano-regulated mechanism during adipogenic differentiation and demonstrate a key role of the actin cytoskeleton in defining nuclear and nucleolar architecture in differentiating human adipose stem cells.


Assuntos
Adipogenia , Citoesqueleto , Humanos , Células Cultivadas , Citoesqueleto/metabolismo , Adipócitos/metabolismo , Gotículas Lipídicas/metabolismo
13.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(2): 475-481, 2024 Mar 20.
Artigo em Chinês | MEDLINE | ID: mdl-38645850

RESUMO

Lipid droplets are dynamic multifunctional organelles composed of a neutral lipid core and a phospholipid monolayer membrane modified by a specific set of proteins. PAT family proteins are the most characteristic lipid droplet proteins, playing an important role in regulating lipid droplet structure, function, and metabolism. The biogenesis of lipid droplets involves neutral lipid synthesis and the nucleation, budding, and growth of the lipid droplets. Lipid droplets not only serve as the energy metabolism reserve of cells but also participate in intracellular signal transduction and the development of inflammation and tumor. Lipid droplets are closely connected to and interact with various organelles, regulating the division, the transportation, and the genetics of organelles. The complexity of lipid droplets biogenesis and the diversity of their functions may have provided a physiological basis for the pathogenesis and development of diseases, but further research is needed in order to better understand the relevant processes. Published findings have helped elucidate the association between lipid droplets and diseases, such as obesity, non-alcoholic fatty liver disease, neurodegenerative disease, cancer, and cardiovascular disease, but the relationship between lipid droplets and oral diseases has not been fully studied. Topics that warrant further research include the role and mechanisms of lipid droplets in the pathogenesis and development of oral diseases, the relationship between oral diseases and systemic diseases, and translation of the effect of lipid droplets on oral diseases into valuable clinical diagnostic and treatment methods. Herein, we reviewed the biogenesis and functions of lipid droplets and the progress in research concerning lipid droplets in oral diseases, including mouth neoplasms, periodontitis, and dental caries.


Assuntos
Gotículas Lipídicas , Humanos , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Doenças da Boca/metabolismo , Obesidade/metabolismo
14.
Luminescence ; 39(4): e4749, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38658767

RESUMO

Lipid droplet, an intracellular lipid reservoir, is vital for energy metabolism and signal transmission in cells. The viscosity directly affects the metabolism of lipid droplets, and the abnormal viscosity is associated with the occurrence and development of various diseases. Therefore, it is indispensable to develop techniques that can detect viscosity changes in intracellular lipid droplets. Based on twisted intramolecular charge transfer (TICT) mechanism, a novel small-molecule lipid droplet-targeted viscosity fluorescence probe PPF-1 was designed. The probe was easy to synthesize, it had a large Stokes shift, stable optical properties, and low bio-toxicity. Compared to being in methanol solution, the fluorescence intensity of PPF-1 in glycerol solution was increased 26.7-fold, and PPF-1 showed excellent ability to target lipid droplets. Thus, the probe PPF-1 could provide an effective means of detecting viscosity changes of lipid droplets and was of great value for physiological diagnosis of related diseases, pathological analysis, and medical research.


Assuntos
Corantes Fluorescentes , Gotículas Lipídicas , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Viscosidade , Gotículas Lipídicas/química , Humanos , Estrutura Molecular , Imagem Óptica , Espectrometria de Fluorescência
15.
Opt Express ; 32(7): 12462-12475, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571068

RESUMO

Quantitative phase contrast microscopy (QPCM) can realize high-quality imaging of sub-organelles inside live cells without fluorescence labeling, yet it requires at least three phase-shifted intensity images. Herein, we combine a novel convolutional neural network with QPCM to quantitatively obtain the phase distribution of a sample by only using two phase-shifted intensity images. Furthermore, we upgraded the QPCM setup by using a phase-type spatial light modulator (SLM) to record two phase-shifted intensity images in one shot, allowing for real-time quantitative phase imaging of moving samples or dynamic processes. The proposed technique was demonstrated by imaging the fine structures and fast dynamic behaviors of sub-organelles inside live COS7 cells and 3T3 cells, including mitochondria and lipid droplets, with a lateral spatial resolution of 245 nm and an imaging speed of 250 frames per second (FPS). We imagine that the proposed technique can provide an effective way for the high spatiotemporal resolution, high contrast, and label-free dynamic imaging of living cells.


Assuntos
Aprendizado Profundo , Imageamento Quantitativo de Fase , Animais , Camundongos , Mitocôndrias , Gotículas Lipídicas
16.
Cell Death Dis ; 15(4): 240, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561354

RESUMO

Abnormal lipid metabolism and lipid accumulation are characteristic hallmarks of renal cell carcinoma (RCC). While there is prior evidence closely linking such lipid accumulation within RCC cells and consequent tumorigenesis, the mechanisms underlying this process remain incompletely understood. In this study, a series of bioinformatics analyses were initially performed by screening RCC databases and gene sets, ultimately leading to the identification of TRIB3 as an oncogene that functions as a central regulator of lipid metabolism. TRIB3 overexpression was observed in both RCC patient tumor tissues and cell lines, and this upregulation was correlated with a worse RCC patient prognosis. When TRIB3 was knocked down, this resulted in a reduction in lipid accumulation and the consequent induction of endoplasmic reticulum (ER) stress-related apoptotic cell death. At the molecular level, interactions between TRIB3 and PLIN2 were found to abrogate TEB4-mediated PLIN2 ubiquitination and consequent degradation, thus maintaining higher PLIN2 expression levels. This simultaneously helps facilitate the accumulation of lipids while preserving ER homeostasis, thus driving accelerated RCC tumor progression. This TRIB3-PLIN2 axis thus represents a promising new target for efforts to treat RCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Humanos , Carcinoma de Células Renais/metabolismo , Gotículas Lipídicas/metabolismo , Estresse do Retículo Endoplasmático/genética , Neoplasias Renais/metabolismo , Lipídeos , Proteínas Repressoras/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Perilipina-2/genética , Perilipina-2/metabolismo
17.
Nat Commun ; 15(1): 3547, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38670976

RESUMO

Typical plant membranes and storage lipids are comprised of five common fatty acids yet over 450 unusual fatty acids accumulate in seed oils of various plant species. Plant oils are important human and animal nutrients, while some unusual fatty acids such as hydroxylated fatty acids (HFA) are used in the chemical industry (lubricants, paints, polymers, cosmetics, etc.). Most unusual fatty acids are extracted from non-agronomic crops leading to high production costs. Attempts to engineer HFA into crops are unsuccessful due to bottlenecks in the overlapping pathways of oil and membrane lipid synthesis where HFA are not compatible. Physaria fendleri naturally overcomes these bottlenecks through a triacylglycerol (TAG) remodeling mechanism where HFA are incorporated into TAG after initial synthesis. TAG remodeling involves a unique TAG lipase and two diacylglycerol acyltransferases (DGAT) that are selective for different stereochemical and acyl-containing species of diacylglycerol within a synthesis, partial degradation, and resynthesis cycle. The TAG lipase interacts with DGAT1, localizes to the endoplasmic reticulum (with the DGATs) and to puncta around the lipid droplet, likely forming a TAG remodeling metabolon near the lipid droplet-ER junction. Each characterized DGAT and TAG lipase can increase HFA accumulation in engineered seed oils.


Assuntos
Diacilglicerol O-Aciltransferase , Ácidos Graxos , Óleos de Plantas , Triglicerídeos , Triglicerídeos/metabolismo , Triglicerídeos/biossíntese , Óleos de Plantas/metabolismo , Óleos de Plantas/química , Diacilglicerol O-Aciltransferase/metabolismo , Diacilglicerol O-Aciltransferase/genética , Ácidos Graxos/metabolismo , Lipase/metabolismo , Sementes/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Gotículas Lipídicas/metabolismo , Plantas Geneticamente Modificadas
18.
Int J Mol Sci ; 25(8)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38674093

RESUMO

Altered metabolism of lipids is a key factor in many diseases including cancer. Therefore, investigations into the impact of unsaturated and saturated fatty acids (FAs) on human body homeostasis are crucial for understanding the development of lifestyle diseases. In this paper, we focus on the impact of palmitic (PA), linoleic (LA), and eicosapentaenoic (EPA) acids on human colon normal (CCD-18 Co) and cancer (Caco-2) single cells using Raman imaging and spectroscopy. The label-free nature of Raman imaging allowed us to evaluate FAs dynamics without modifying endogenous cellular metabolism. Thanks to the ability of Raman imaging to visualize single-cell substructures, we have analyzed the changes in chemical composition of endoplasmic reticulum (ER), mitochondria, lipid droplets (LDs), and nucleus upon FA supplementation. Analysis of Raman band intensity ratios typical for lipids, proteins, and nucleic acids (I1656/I1444, I1444/I1256, I1444/I750, I1304/I1256) proved that, using Raman mapping, we can observe the metabolic pathways of FAs in ER, which is responsible for the uptake of exogenous FAs, de novo synthesis, elongation, and desaturation of FAs, in mitochondria responsible for energy production via FA oxidation, in LDs specialized in cellular fat storage, and in the nucleus, where FAs are transported via fatty-acid-binding proteins, biomarkers of human colon cancerogenesis. Analysis for membranes showed that the uptake of FAs effectively changed the chemical composition of this organelle, and the strongest effect was noticed for LA. The spectroscopy studies have been completed using XTT tests, which showed that the addition of LA or EPA for Caco-2 cells decreases their viability with a stronger effect observed for LA and the opposite effect observed for PA. For normal cells, CCD-18 Co supplementation using LA or EPA stimulated cells for growing, while PA had the opposite impact.


Assuntos
Neoplasias do Colo , Ácidos Graxos , Análise de Célula Única , Análise Espectral Raman , Humanos , Análise Espectral Raman/métodos , Análise de Célula Única/métodos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Ácidos Graxos/metabolismo , Células CACO-2 , Metabolismo dos Lipídeos , Colo/metabolismo , Colo/patologia , Gotículas Lipídicas/metabolismo , Mitocôndrias/metabolismo , Retículo Endoplasmático/metabolismo
19.
Cell Mol Life Sci ; 81(1): 190, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649521

RESUMO

The high-protein diet (HPD) has emerged as a potent dietary approach to curb obesity. Peroxisome, a highly malleable organelle, adapts to nutritional changes to maintain homeostasis by remodeling its structure, composition, and quantity. However, the impact of HPD on peroxisomes and the underlying mechanism remains elusive. Using Drosophila melanogaster as a model system, we discovered that HPD specifically increases peroxisome levels within the adipose tissues. This HPD-induced peroxisome elevation is attributed to cysteine and methionine by triggering the expression of CG33474, a fly homolog of mammalian PEX11G. Both the overexpression of Drosophila CG33474 and human PEX11G result in increased peroxisome size. In addition, cysteine and methionine diets both reduce lipid contents, a process that depends on the presence of CG33474. Furthermore, CG33474 stimulates the breakdown of neutral lipids in a cell-autonomous manner. Moreover, the expression of CG33474 triggered by cysteine and methionine requires TOR signaling. Finally, we found that CG33474 promotes inter-organelle contacts between peroxisomes and lipid droplets (LDs), which might be a potential mechanism for CG33474-induced fat loss. In summary, our findings demonstrate that CG33474/PEX11G may serve as an essential molecular bridge linking HPD to peroxisome dynamics and lipid metabolism.


Assuntos
Tecido Adiposo , Cisteína , Proteínas de Drosophila , Drosophila melanogaster , Metionina , Peroxissomos , Animais , Metionina/metabolismo , Peroxissomos/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/metabolismo , Drosophila melanogaster/genética , Cisteína/metabolismo , Tecido Adiposo/metabolismo , Humanos , Metabolismo dos Lipídeos , Gotículas Lipídicas/metabolismo , Transdução de Sinais , Dieta
20.
Anal Methods ; 16(18): 2850-2856, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38644726

RESUMO

Early diagnostics and therapies for diseases such as cancer are limited by the fact that the inducing factors for the development of cytopathies are not clear. The stable polarity of lipid droplets is a potential biomarker for tumor cells; however, the complex intracellular biological environment poses great difficulties for specific detection of the polarity. Therefore, to meet this pressing challenge, we designed a highly selective fluorescent probe, DCI-Cou-polar, which used the ICT mechanism to differentiate normal cells and tumor cells in tissue sections by detecting changes in the polarities of intracellular lipid droplets. The introduction of a cyclic amine at the 7-position of coumarin (benzoquinolizine coumarin) reduced its ability to donate electrons compared with the diethylamino group, which increased the probe selectivity while retaining the sensitivity to polarity. With NIR emission and large Stokes shifts, DCI-Cou-polar has high sensitivity to polarity, excellent photostability, and biocompatibility, and it tracks lipid droplets with high fidelity. Therefore, we believe that this polarity-sensitive probe provides information on the connection between the polarity of lipid droplets and tumors while improving the development of highly selective polarity probes.


Assuntos
Cumarínicos , Corantes Fluorescentes , Corantes Fluorescentes/química , Humanos , Cumarínicos/química , Animais , Gotículas Lipídicas/química , Neoplasias/patologia , Camundongos , Polaridade Celular , Linhagem Celular Tumoral
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