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Journal of Integrative Neuroscience Jun 2024The majority of neuromyelitis optica spectrum disorders (NMOSD) patients are seropositive for aquaporin-4 (AQP4)-specific antibodies [also named neuromyelitis optica...
OBJECTIVES
The majority of neuromyelitis optica spectrum disorders (NMOSD) patients are seropositive for aquaporin-4 (AQP4)-specific antibodies [also named neuromyelitis optica immunoglobulin G antibodies (NMO-IgG)]. Although NMO-IgG can induce pathological changes in the central nervous system (CNS), the immunological changes in the CNS and peripheral tissue remain largely unknown. We investigated whether NMO-IgG binds to tissue expressing AQP4 and induces immunological changes in the peripheral tissue and CNS.
METHODS
C57BL/6 female mice were assigned into an NMOSD or control group. Pathological and immunological changes in peripheral tissue and CNS were measured by immunostaining and flow cytometry, respectively. Motor impairment was measured by open-field test.
RESULTS
We found that NMO-IgG did bind to astrocyte- and AQP4-expressing peripheral tissue, but induced glial fibrillary acidic protein and AQP4 loss only in the CNS. NMO-IgG induced the activation of microglia and modulated microglia polarization toward the classical (M1) phenotype, but did not affect innate or adaptive immune cells in the peripheral immune system, such as macrophages, neutrophils, Th17/Th1, or IL-10-producing B cells. In addition, NMOSD mice showed significantly less total distance traveled and higher immobility time in the open field.
CONCLUSIONS
We found that injection of human NMO-IgG led to astrocytopathic lesions with microglial activation in the CNS. However, there were no significant pathological or immunological changes in the peripheral tissues.
Topics: Animals; Neuromyelitis Optica; Mice, Inbred C57BL; Immunoglobulin G; Aquaporin 4; Female; Humans; Mice; Disease Models, Animal; Microglia; Autoantibodies; Astrocytes; Glial Fibrillary Acidic Protein; Central Nervous System
PubMed: 38940087
DOI: 10.31083/j.jin2306119 -
Frontiers in Bioscience (Landmark... Jun 2024Nonalcoholic fatty liver disease (NAFLD) is a prevalent condition characterized by hepatic fat accumulation, often progressing to severe liver injury, for which approved...
BACKGROUND
Nonalcoholic fatty liver disease (NAFLD) is a prevalent condition characterized by hepatic fat accumulation, often progressing to severe liver injury, for which approved treatments are currently lacking. This study explores the potential therapeutic impact of alpha-lipoic acid (ALA), a natural compound crucial in lipid metabolism, on NAFLD using an model.
METHODS
HepG2 cells were treated with a palmitic acid:oleic acid (PA:OA) mixture, representing a cellular model of steatosis. Subsequent treatment with ALA at concentrations of 1 µM and 5 µM aimed to evaluate its effects on lipid content and metabolism. Real-time polymerase chain reaction (PCR), BODIPY staining, cytofluorimetric analysis, and lipidomics were used to assess gene expression, lipid droplet accumulation, and fatty acid profiles.
RESULTS
Our results showed that ALA significantly reduced lipid droplets in PA:OA-treated HepG2 cells, with a concentration-dependent effect. Analysis of fatty acid profiles demonstrated a decrease in palmitic acid levels with ALA treatment, while oleic acid reduction was observed only at the higher concentration. Moreover, ALA modulated the expression of genes involved in cholesterol biosynthesis and low-density lipoprotein (LDL) metabolism, indicating a potential role in lipid homeostasis. Further insights into molecular mechanisms revealed that ALA modulated peroxisome proliferator activated receptors (PPARs), specifically PPAR-alpha and PPAR-gamma, involved in fatty acid metabolism and insulin sensitivity. Finally, ALA counteracted the overexpression of thermogenic genes induced by exogenous fatty acids, suggesting a regulatory role in energy dissipation pathways.
CONCLUSION
In conclusion, this study highlights ALA as a therapeutic agent in mitigating lipid accumulation and dysregulation in NAFLD.
Topics: Humans; Thioctic Acid; Hep G2 Cells; Lipid Metabolism; Non-alcoholic Fatty Liver Disease; Oleic Acid; Palmitic Acid; Gene Expression Regulation; Fatty Acids; PPAR gamma; Lipid Droplets; PPAR alpha; Uncoupling Protein 2
PubMed: 38940024
DOI: 10.31083/j.fbl2906209 -
Sheng Li Xue Bao : [Acta Physiologica... Jun 2024Copper is a vital trace metal element necessary for the functioning of living organisms. It serves as a co-factor or structural component in numerous enzymes,... (Review)
Review
Copper is a vital trace metal element necessary for the functioning of living organisms. It serves as a co-factor or structural component in numerous enzymes, participating in crucial biological metabolic processes. Disruptions in copper homeostasis, whether inherited or acquired, such as copper overload, deficiency, or uneven distribution, can contribute to or exacerbate various diseases, including Menkes disease, Wilson's disease, neurodegenerative disorders, anemia, cardiovascular diseases, kidney diseases and cancer. Recent research has highlighted the close correlation between chronic kidney disease and intracellular copper overload. Therefore, renal cells must establish a well-organized and efficient copper regulation network to maintain intracellular copper homeostasis. This review summarizes the processes of copper uptake, intracellular trafficking, storage, and excretion in renal cells, and elucidates the underlying mechanisms involved, aiming to provide a theoretical foundation and potential therapeutic targets for the fundamental investigation and clinical management of kidney-related diseases.
Topics: Homeostasis; Humans; Copper; Kidney; Animals; Cation Transport Proteins; Kidney Diseases; Adenosine Triphosphatases; Copper-Transporting ATPases; Copper Transporter 1
PubMed: 38939942
DOI: No ID Found -
Journal of Extracellular Biology May 2024Microvesicles (MVs) are a subtype of extracellular vesicles that can transfer biological information from their producer cells to target cells. This communication can in...
Microvesicles (MVs) are a subtype of extracellular vesicles that can transfer biological information from their producer cells to target cells. This communication can in turn affect both normal and pathological processes. Mounting evidence has revealed that dermal wound myofibroblasts (Wmyo) produce MVs, which can transfer biomolecules impacting receptor cells such as human dermal microvascular endothelial cells (HDMECs). While the effects of MVs on HDMECs are generally well described in the literature, little is known about the transport of MVs across the HDMEC barrier, and their potential effect on the barrier integrity remains unknown. Here, we investigated these roles of Wmyo-derived MVs on two sub-populations of HDMECs, blood endothelial cells (BECs) and lymphatic endothelial cells (LECs). Using an in vitro model to mimic the endothelial barrier, we showed that MVs crossed the LEC barrier but not the BEC barrier. In addition, we demonstrated that MVs were able to influence the cell-cell junctions of HDMECs. Specifically, we observed that after internalization via the predominantly caveolin-dependent pathway, MVs induced the opening of junctions in BECs. Conversely, in LECs, MVs mainly use the macropinocytosis pathway and induce closure of these junctions. Moreover, proteins in the MV membrane were responsible for this effect, but not specifically those belonging to the VEGF family. Finally, we found that once the LEC barrier permeability was reduced by MV stimuli, MVs ceased to cross the barrier. Conversely, when the BEC barrier was rendered permeable following stimulation with MVs, they were subsequently able to cross the barrier via the paracellular pathway. Taken together, these results suggest that the study of Wmyo-derived MVs offers valuable insights into their interaction with the HDMEC barrier in the context of wound healing. They highlight the potential significance of these MVs in the overall process.
PubMed: 38939570
DOI: 10.1002/jex2.151 -
PeerJ 2024Pyrophosphatases (PPases) are enzymes that catalyze the hydrolysis of pyrophosphate (PPi), a byproduct of the synthesis and degradation of diverse biomolecules. The... (Review)
Review
Pyrophosphatases (PPases) are enzymes that catalyze the hydrolysis of pyrophosphate (PPi), a byproduct of the synthesis and degradation of diverse biomolecules. The accumulation of PPi in the cell can result in cell death. Although the substrate is the same, there are variations in the catalysis and features of these enzymes. Two enzyme forms have been identified in bacteria: cytoplasmic or soluble pyrophosphatases and membrane-bound pyrophosphatases, which play major roles in cell bioenergetics. In eukaryotic cells, cytoplasmic enzymes are the predominant form of PPases (c-PPases), while membrane enzymes (m-PPases) are found only in protists and plants. The study of bacterial cytoplasmic and membrane-bound pyrophosphatases has slowed in recent years. These enzymes are central to cell metabolism and physiology since phospholipid and nucleic acid synthesis release important amounts of PPi that must be removed to allow biosynthesis to continue. In this review, two aims were pursued: first, to provide insight into the structural features of PPases known to date and that are well characterized, and to provide examples of enzymes with novel features. Second, the scientific community should continue studying these enzymes because they have many biotechnological applications. Additionally, in this review, we provide evidence that there are m-PPases present in fungi; to date, no examples have been characterized. Therefore, the diversity of PPase enzymes is still a fruitful field of research. Additionally, we focused on the roles of H/Na pumps and m-PPases in cell bioenergetics. Finally, we provide some examples of the applications of these enzymes in molecular biology and biotechnology, especially in plants. This review is valuable for professionals in the biochemistry field of protein structure-function relationships and experts in other fields, such as chemistry, nanotechnology, and plant sciences.
Topics: Inorganic Pyrophosphatase; Bacteria; Fungi; Diphosphates
PubMed: 38938619
DOI: 10.7717/peerj.17496 -
Cell Biochemistry and Function Jul 2024Multidrug resistance (MDR) during clinical chemotherapy for cancer has been considered a major obstacle to treatment efficacy. The involvement of adenosine...
Multidrug resistance (MDR) during clinical chemotherapy for cancer has been considered a major obstacle to treatment efficacy. The involvement of adenosine triphosphate-binding cassette (ABC) transporters in the MDR mechanism significantly reduces the efficacy of chemotherapeutics. This study investigates the potential of morin, a dietary bioflavonoid, to overcome colchicine resistance in KBChR-8-5 MDR cells. The P-gp inhibitory activity by morin was measured by calcein-AM drug efflux assay. Western blot analysis was employed to evaluate P-gp messenger RNA and protein expressions following morin treatment. Flow cytometry analysis and acridine orange/ethidium bromide fluorescence staining were utilised to investigate the induction of apoptosis and cell cycle arrest upon treatment with morin and paclitaxel in combination. Additionally, polymerase chain reaction (PCR) array analysis was conducted to study the gene expression profiles related to MDR, apoptosis and cell cycle arrest during treatment with morin, paclitaxel or their combination. Morin exhibited a strong binding interaction with human P-gp. This was corroborated by drug efflux assays, which showed a reduction in P-gp efflux function with increasing morin concentration. Furthermore, morin and paclitaxel combination potentiated the induction of apoptosis and G2/M phase cell cycle arrest. Morin treatment significantly downregulated the gene expression of ABCB1 and P-gp membrane expressions in MDR cells. Additionally, PCR array gene expression analysis revealed that the combination treatment with morin and paclitaxel upregulated proapoptotic and cell cycle arrest genes while downregulating ABCB1 gene and antiapoptotic genes. Thus, morin effectively reversed paclitaxel resistance in KBChR-8-5 drug-resistant cancer cells and concluded that morin resensitized the paclitaxel resistance in KBChR8-5 drug-resistant cancer cells.
Topics: Humans; Flavonoids; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Apoptosis; Paclitaxel; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line, Tumor; Cell Cycle Checkpoints; ATP Binding Cassette Transporter, Subfamily B; Antineoplastic Agents; Flavones
PubMed: 38938150
DOI: 10.1002/cbf.4083 -
Military Medical Research Jun 2024Extracellular adenosine triphosphate (ATP) is an important signal molecule. In previous studies, intensive research had revealed the crucial roles of family with...
BACKGROUND
Extracellular adenosine triphosphate (ATP) is an important signal molecule. In previous studies, intensive research had revealed the crucial roles of family with sequence similarity 3 member A (FAM3A) in controlling hepatic glucolipid metabolism, islet β cell function, adipocyte differentiation, blood pressure, and other biological and pathophysiological processes. Although mitochondrial protein FAM3A plays crucial roles in the regulation of glucolipid metabolism via stimulating ATP release to activate P2 receptor pathways, its mechanism in promoting ATP release in hepatocytes remains unrevealed.
METHODS
db/db, high-fat diet (HFD)-fed, and global pannexin 1 (PANX1) knockout mice, as well as liver sections of individuals, were used in this study. Adenoviruses and adeno-associated viruses were utilized for in vivo gene overexpression or inhibition. To evaluate the metabolic status in mice, oral glucose tolerance test (OGTT), pyruvate tolerance test (PTT), insulin tolerance test (ITT), and magnetic resonance imaging (MRI) were conducted. Protein-protein interactions were determined by coimmunoprecipitation with mass spectrometry (MS) assays.
RESULTS
In livers of individuals and mice with steatosis, the expression of ATP-permeable channel PANX1 was increased (P < 0.01). Hepatic PANX1 overexpression ameliorated the dysregulated glucolipid metabolism in obese mice. Mice with hepatic PANX1 knockdown or global PANX1 knockout exhibited disturbed glucolipid metabolism. Restoration of hepatic PANX1 rescued the metabolic disorders of PANX1-deficient mice (P < 0.05). Mechanistically, ATP release is mediated by the PANX1-activated protein kinase B-forkhead box protein O1 (Akt-FOXO1) pathway to inhibit gluconeogenesis via P2Y receptors in hepatocytes. PANX1-mediated ATP release also activated calmodulin (CaM) (P < 0.01), which interacted with c-Jun N-terminal kinase (JNK) to inhibit its activity, thereby deactivating the transcription factor activator protein-1 (AP1) and repressing fatty acid synthase (FAS) expression and lipid synthesis (P < 0.05). FAM3A stimulated the expression of PANX1 via heat shock factor 1 (HSF1) in hepatocytes (P < 0.05). Notably, FAM3A overexpression failed to promote ATP release, inhibit the expression of gluconeogenic and lipogenic genes, and suppress gluconeogenesis and lipid deposition in PANX1-deficient hepatocytes and livers.
CONCLUSIONS
PANX1-mediated release of ATP plays a crucial role in maintaining hepatic glucolipid homeostasis, and it confers FAM3A's suppressive effects on hepatic gluconeogenesis and lipogenesis.
Topics: Animals; Connexins; Mice; Gluconeogenesis; Nerve Tissue Proteins; Adenosine Triphosphate; Lipogenesis; Liver; Mice, Knockout; Male; Humans; Diet, High-Fat; Cytokines
PubMed: 38937853
DOI: 10.1186/s40779-024-00543-6 -
World Journal of Microbiology &... Jun 2024In this study, the utilization mechanism of oligosaccharides by Bifidobacterium was investigated through the transcriptome sequencing and non-targeted metabolomics...
In this study, the utilization mechanism of oligosaccharides by Bifidobacterium was investigated through the transcriptome sequencing and non-targeted metabolomics technology of Bifidobacterium animalis cultured with fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS). The results showed that FOS affected the synthesis of adenosine triphosphate binding transporters (ABC transporters) by increasing the expression levels of msmE, msmG, and gluA. Similarly, GOS improved aminoacyl-tRNA synthases by upregulating the expression of tRNA-Ala, tRNA-Pro, and tRNA-Met. Bifidobacterium animalis cultured with FOS and GOS produced different metabolites, such as histamine, tartaric acid, and norepinephrine, with the functions of inhibiting inflammation, alleviating depression and diseases related to brain and nervous system and maintaining body health. Furthermore, the transcriptome and metabolome analysis results revealed that FOS and GOS promoted the growth and metabolism of Bifidobacterium animalis by regulating the related pathways of carbohydrate, energy, and amino acid metabolism. Overall, the experimental results provided significant insights into the prebiotic effects of FOS and GOS.
Topics: Prebiotics; Bifidobacterium animalis; Oligosaccharides; Metabolomics; Transcriptome; Metabolome; Gene Expression Regulation, Bacterial; Gene Expression Profiling; Bacterial Proteins; ATP-Binding Cassette Transporters; Amino Acids
PubMed: 38937374
DOI: 10.1007/s11274-024-04061-4 -
Journal of Molecular Modeling Jun 2024Existing researches confirmed that β amyloid (Aβ) has a high affinity for the α7 nicotinic acetylcholine receptor (α7nAChR), associating closely to Alzheimer's...
CONTEXT
Existing researches confirmed that β amyloid (Aβ) has a high affinity for the α7 nicotinic acetylcholine receptor (α7nAChR), associating closely to Alzheimer's disease. The majority of related studies focused on the experimental reports on the neuroprotective role of Aβ fragment (Aβ), however, with a lack of investigation into the most suitable binding region and mechanism of action between Aβ fragment and α7nAChR. In the study, we employed four Aβ fragments Aβ, Aβ, Aβ, Aβ, and Aβ, of which the first three were confirmed to play neuroprotective roles upon directly binding, to interact with α7nAChR.
METHODS
The protein-ligand docking server of CABS-DOCK was employed to obtain the α7nAChR-Aβ complexes. Only the top α7nAChR-Aβ complexes were used to perform all-atom GROMACS dynamics simulation in combination with Charmm36 force field, by which α7nAChR-Aβ interactions' dynamic behavior and specific locations of these different Aβ fragments were identified. MM-PBSA calculations were also done to estimate the binding free energies and the different contributions from the residues in the Aβ. Two distinct results for the first three and fourth Aβ fragments in binding site, strength, key residue, and orientation, account for why the fourth fails to play a neuroprotective role at the molecular level.
Topics: Amyloid beta-Peptides; alpha7 Nicotinic Acetylcholine Receptor; Molecular Dynamics Simulation; Peptide Fragments; Protein Binding; Humans; Molecular Docking Simulation; Binding Sites; Ligands
PubMed: 38937296
DOI: 10.1007/s00894-024-06032-w -
Journal of Molecular Biology Jun 2024Assessing membrane protein stability is among the major challenges in protein science due to their inherent complexity, which complicates the application of conventional...
The structural stability of membrane proteins revisited: Combined thermodynamic and spectral phasor analysis of SDS-induced denaturation of a thermophilic Cu(I)-transport ATPase.
Assessing membrane protein stability is among the major challenges in protein science due to their inherent complexity, which complicates the application of conventional biophysical tools. In this work, sodium dodecyl sulfate-induced denaturation of AfCopA, a Cu(I)-transport ATPase from Archaeoglobus fulgidus, was explored using a combined model-free spectral phasor analysis and a model-dependent thermodynamic analysis. Decrease in tryptophan and 1-anilino-naphthalene-8-sulfonate fluorescence intensity, displacements in the spectral phasor space, and the loss of ATPase activity were reversibly induced by this detergent. Refolding from the SDS-induced denatured state yields an active enzyme that is functionally and spectroscopically indistinguishable from the native state of the protein. Phasor analysis of Trp spectra allowed us to identify two intermediate states in the SDS-induced denaturation of AfCopA, a result further supported by principal component analysis. In contrast, traditional thermodynamic analysis detected only one intermediate state, and including the second one led to overparameterization. Additionally, ANS fluorescence spectral analysis detected one more intermediate and a gradual change at the level of the hydrophobic transmembrane surface of the protein. Based on this evidence, a model for acquiring the native structure of AfCopA in a membrane-like environment is proposed.
PubMed: 38936696
DOI: 10.1016/j.jmb.2024.168689