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Journal of Translational Medicine Dec 2023Magnetic resonance fingerprinting (MRF) enables fast myelin quantification via the myelin water fraction (MWF), offering a noninvasive method to assess brain development...
BACKGROUND
Magnetic resonance fingerprinting (MRF) enables fast myelin quantification via the myelin water fraction (MWF), offering a noninvasive method to assess brain development and disease. However, MRF-derived MWF lacks histological evaluation and remains unexamined in relation to leukodystrophy. This study aimed to access MRF-derived MWF through histology in mice and establish links between myelin, development, and leukodystrophy in mice and children, demonstrating its potential applicability in animal and human studies.
METHODS
3D MRF was performed on normal C57BL/6 mice with different ages, megalencephalic leukoencephalopathy with subcortical cyst 1 wild type (MLC1 WT, control) mice, and MLC 1 knock-out (MLC1 KO, leukodystrophy) mice using a 3 T MRI. MWF values were analyzed from 3D MRF data, and histological myelin quantification was carried out using immunohistochemistry to anti-proteolipid protein (PLP) in the corpus callosum and cortex. The associations between 'MWF and PLP' and 'MWF and age' were evaluated in C57BL/6 mice. MWF values were compared between MLC1 WT and MLC1 KO mice. MWF of normal developing children were retrospectively collected and the association between MWF and age was assessed.
RESULTS
In 35 C57BL/6 mice (age range; 3 weeks-48 weeks), MWF showed positive relations with PLP immunoreactivity in the corpus callosum (β = 0.0006, P = 0.04) and cortex (β = 0.0005, P = 0.006). In 12-week-old C57BL/6 mice MWF showed positive relations with PLP immunoreactivity (β = 0.0009, P = 0.003, R = 0.54). MWF in the corpus callosum (β = 0.0022, P < 0.001) and cortex (β = 0.0010, P < 0.001) showed positive relations with age. Seven MLC1 WT and 9 MLC1 KO mice showed different MWF values in the corpus callous (P < 0.001) and cortex (P < 0.001). A total of 81 children (median age, 126 months; range, 0-199 months) were evaluated and their MWF values according to age showed the best fit for the third-order regression model (adjusted R range, 0.44-0.94, P < 0.001).
CONCLUSION
MWF demonstrated associations with histologic myelin quantity, age, and the presence of leukodystrophy, underscoring the potential of 3D MRF-derived MWF as a rapid and noninvasive quantitative indicator of brain myelin content in both mice and humans.
Topics: Child; Humans; Mice; Animals; Myelin Sheath; Water; Retrospective Studies; Mice, Inbred C57BL; Magnetic Resonance Imaging; Brain; Neurodegenerative Diseases
PubMed: 38102606
DOI: 10.1186/s12967-023-04788-y -
International Journal of Molecular... Nov 2023Chlorogenic acid (CGA), a polyphenol found mainly in coffee and tea, exerts antioxidant, anti-inflammatory and anti-apoptotic effects at the gastrointestinal level....
Chlorogenic acid (CGA), a polyphenol found mainly in coffee and tea, exerts antioxidant, anti-inflammatory and anti-apoptotic effects at the gastrointestinal level. However, although CGA is known to cross the blood-brain barrier (BBB), its effects on the CNS are still unknown. Oligodendrocytes (OLs), the myelin-forming cells in the CNS, are the main target in demyelinating neuroinflammatory diseases such as multiple sclerosis (MS). We evaluated the antioxidant, anti-inflammatory and anti-apoptotic roles of CGA in M03-13, an immortalized human OL cell line. We found that CGA reduces intracellular superoxide ions, mitochondrial reactive oxygen species (ROS) and NADPH oxidases (NOXs) /dual oxidase 2 (DUOX2) protein levels. The stimulation of M03-13 cells with TNFα activates the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-kB) pathway, leading to an increase in superoxide ion, NOXs/DUOX2 and phosphorylated extracellular regulated protein kinase (pERK) levels. In addition, tumor necrosis factor alpha (TNF-α) stimulation induces caspase 8 activation and the cleavage of poly-ADP-ribose polymerase (PARP). All these TNFα-induced effects are reversed by CGA. Furthermore, CGA induces a blockade of proliferation, driving cells to differentiation, resulting in increased mRNA levels of myelin basic protein (MBP) and proteolipid protein (PLP), which are major markers of mature OLs. Overall, these data suggest that dietary supplementation with this polyphenol could play an important beneficial role in autoimmune neuroinflammatory diseases such as MS.
Topics: Humans; Antioxidants; Chlorogenic Acid; Tumor Necrosis Factor-alpha; Superoxides; Neuroinflammatory Diseases; Dual Oxidases; Anti-Inflammatory Agents; Polyphenols; Oligodendroglia
PubMed: 38069054
DOI: 10.3390/ijms242316731 -
Medicina (Kaunas, Lithuania) Nov 2023Diverticulosis is frequently accompanied by altered bowel habits. The biogenic amines within colonic mucosa control bowel motility, and in particular, alterations in...
Diverticulosis is frequently accompanied by altered bowel habits. The biogenic amines within colonic mucosa control bowel motility, and in particular, alterations in serotonin signaling may play a role in colon diverticulosis. The aim of the study was to assess the concentration of biogenic amines and serotonin receptor expression in the colonic mucosa in patients with diverticulosis and healthy controls. This prospective, comparative study included 59 individuals: 35 with sigmoid diverticulosis and 24 healthy controls. The study was held at the Department of Gastroenterology and Internal Medicine, Medical University of Warsaw, Poland. Mucosal samples were taken from the right and left colon during a colonoscopy in all patients. Concentrations of norepinephrine, 3-methoxy-4-hydroxyphenylglycol, dopamine, homovanillic acid, serotonin, and 5hydroxyindoleacetic acid were measured with high-performance liquid chromatography. Expressions of human 5-hydroxytryptamine receptor 3A, 5-hydroxytryptamine receptor 4, 5-hydroxytryptamine receptor 7, solute carrier family 6 member 4 (SERT) for serotonin, as well as the neuroglia activation markers glial fibrillary acidic protein, S100 calcium-binding protein B, and proteolipid protein 1, were assessed with polymerase chain reaction. The median age and sex distribution were comparable in both study groups (median 69 y vs. 52 y; < 0.455 and males/females in cases 11/17 vs. 18/19 in controls; < 0.309). In diverticulosis patients, there was a higher concentration of serotonin in the left affected colon compared to the right healthy part of the colon (median 8239 pg/mg vs. 6326 pg/mL; < 0.01). The expression was lower in the affected left segment compared to the right colon (median 0.88 vs. 1.36; < 0.01). There was a higher colonic mucosa concentration of serotonin (median 8239 pg/mg vs. 6000 pg/mL; < 0.02) and 5hydroxyindoleacetic acid/serotonin ratio (median 0.27 vs. 0.47; < 0.01) in diverticulosis patients compared to controls in the left side of the colon. The concentration of serotonin in the mucosa of the colon segment affected by diverticula is higher than in the healthy segment in the same individuals and higher than in healthy controls. These results underline serotonin signaling in colon diverticulosis pathophysiology.
Topics: Humans; Male; Female; Serotonin; Prospective Studies; Hydroxyindoleacetic Acid; Colon; Receptors, Serotonin; Diverticulum
PubMed: 38003994
DOI: 10.3390/medicina59111945 -
Protein Science : a Publication of the... Jan 2024Pulmonary surfactant (PS) is a lipid-protein complex that forms films reducing surface tension at the alveolar air-liquid interface. Surfactant protein C (SP-C) plays a...
Pulmonary surfactant (PS) is a lipid-protein complex that forms films reducing surface tension at the alveolar air-liquid interface. Surfactant protein C (SP-C) plays a key role in rearranging the lipids at the PS surface layers during breathing. The N-terminal segment of SP-C, a lipopeptide of 35 amino acids, contains two palmitoylated cysteines, which affect the stability and structure of the molecule. The C-terminal region comprises a transmembrane α-helix that contains a ALLMG motif, supposedly analogous to a well-studied dimerization motif in glycophorin A. Previous studies have demonstrated the potential interaction between SP-C molecules using approaches such as Bimolecular Complementation assays or computational simulations. In this work, the oligomerization state of SP-C in membrane systems has been studied using fluorescence spectroscopy techniques. We have performed self-quenching and FRET assays to analyze dimerization of native palmitoylated SP-C and a non-palmitoylated recombinant version of SP-C (rSP-C) using fluorescently labeled versions of either protein reconstituted in different lipid systems mimicking pulmonary surfactant environments. Our results reveal that doubly palmitoylated native SP-C remains primarily monomeric. In contrast, non-palmitoylated recombinant SP-C exhibits dimerization, potentiated at high concentrations, especially in membranes with lipid phase separation. Therefore, palmitoylation could play a crucial role in stabilizing the monomeric α-helical conformation of SP-C. Depalmitoylation, high protein densities as a consequence of membrane compartmentalization, and other factors may all lead to the formation of protein dimers and higher-order oligomers, which could have functional implications under certain pathological conditions and contribute to membrane transformations associated with surfactant metabolism and alveolar homeostasis.
Topics: Pulmonary Surfactant-Associated Protein C; Pulmonary Surfactants; Fluorescence Resonance Energy Transfer; Lipids; Surface-Active Agents
PubMed: 37984447
DOI: 10.1002/pro.4835 -
Aging Nov 2023The abnormality of surfactant protein C (SFTPC) has been linked to the development of a number of interstitial lung diseases, according to mounting evidence....
The abnormality of surfactant protein C (SFTPC) has been linked to the development of a number of interstitial lung diseases, according to mounting evidence. Nonetheless, the function and mechanism of SFTPC in the biological progression of lung adenocarcinoma (LUAD) remain unclear. Analysis of public datasets and testing of clinical samples suggested that SFTPC expression was abnormally low in LUAD, which was associated with the onset and poor prognosis of LUAD. The SFTPC-related risk score was derived using least absolute shrinkage and selection operator Cox regression as well as multivariate Cox regression. The risk score was highly correlated with tumor purity and tumor mutation burden, and it could serve as an independent prognostic indicator for LUAD. Low-risk LUAD patients may benefit more from CTLA-4 or/and PD-1 inhibitors. Overall, the risk score is useful for LUAD patient prognostication and treatment guidance. Moreover, and experiments demonstrated that SFTPC inhibits the proliferation of LUAD by inhibiting PI3K/AKT/mTOR signaling transduction. These results reveal the molecular mechanism by which SFTPC inhibits the proliferation of LUAD and suggest that SFTPC could be a new therapeutic target for LUAD.
Topics: Humans; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; Lung Neoplasms; Cell Proliferation; Adenocarcinoma of Lung; TOR Serine-Threonine Kinases; Gene Expression Regulation, Neoplastic; Pulmonary Surfactant-Associated Protein C
PubMed: 37955668
DOI: 10.18632/aging.205191 -
Molecular & Cellular Proteomics : MCP Dec 2023α-Synuclein, a protein mostly present in presynaptic terminals, accumulates neuropathologically in Parkinson's disease in a 6-stage sequence and propagates in the...
α-Synuclein, a protein mostly present in presynaptic terminals, accumulates neuropathologically in Parkinson's disease in a 6-stage sequence and propagates in the nervous system in a prion-like manner through neurons and glia. In stage 3, the substantia nigra are affected, provoking motor symptoms and the amygdaloid complex, leading to different nonmotor symptoms; from here, synucleinopathy spreads to the temporal cortex and beyond. The expected increase in Parkinson's disease incidence accelerates the need for detection biomarkers; however, the heterogeneity of this disease, including pathological aggregates and pathophysiological pathways, poses a challenge in the search for new therapeutic targets and biomarkers. Proteomic analyses are lacking, and the literature regarding synucleinopathy, neural and glial involvement, and volume of the human amygdaloid complex is controversial. Therefore, the present study combines both proteomic and stereological probes. Data-independent acquisition-parallel accumulation of serial fragmentation proteomic analysis revealed a remarkable proteomic impact, especially at the synaptic level in the human amygdaloid complex in Parkinson's disease. Among the 199 differentially expressed proteins, guanine nucleotide-binding protein G(i) subunit alpha-1 (GNAI1), elongation factor 1-alpha 1 (EEF1A1), myelin proteolipid protein (PLP1), neuroplastin (NPTN), 14-3-3 protein eta (YWHAH), gene associated with retinoic and interferon-induced mortality 19 protein (GRIM19), and orosomucoid-2 (ORM2) stand out as potential biomarkers in Parkinson's disease. Stereological analysis, however, did not reveal alterations regarding synucleinopathy, neural or glial populations, or volume changes. To our knowledge, this is the first proteomic study of the human amygdaloid complex in Parkinson's disease, and it identified possible biomarkers of the disease. Lewy pathology could not be sufficient to cause neurodegeneration or alteration of microglial and astroglial populations in the human amygdaloid complex in Parkinson's disease. Nevertheless, damage at the proteomic level is manifest, showing up significant synaptic involvement.
Topics: Humans; Parkinson Disease; Synucleinopathies; Proteomics; alpha-Synuclein; Amygdala; Biomarkers
PubMed: 37947401
DOI: 10.1016/j.mcpro.2023.100673 -
BioRxiv : the Preprint Server For... Oct 2023Diverse developmental signals and pro-death stresses converge on regulation of the mitochondrial pathway of apoptosis. BAX, a pro-apoptotic BCL-2 effector, directly...
Diverse developmental signals and pro-death stresses converge on regulation of the mitochondrial pathway of apoptosis. BAX, a pro-apoptotic BCL-2 effector, directly forms proteolipid pores in the outer mitochondrial member to activate the mitochondrial pathway of apoptosis. BAX is a viable pharmacological target for various human diseases, and increasing efforts have been made to study the molecular regulation of BAX and identify small molecules selectively targeting BAX. However, generating large quantities of monomeric and functionally-competent BAX has been challenging due to its aggregation-prone nature. Additionally, there is a lack of detailed and instructional protocols available for investigators who are not already familiar with recombinant BAX production. Here, we present a comprehensive high-yield protocol for expressing, purifying, and storing functional recombinant BAX protein. We utilize an intein-tagged BAX construct and employ a two-step chromatography strategy to capture and purify BAX, and provide example standard assays to observe BAX activation. We also highlight best practices for handling and storing BAX to effectively preserve its quality, shelf-life, and function.
PubMed: 37905126
DOI: 10.1101/2023.10.16.562589 -
Nature Communications Oct 2023Axon degeneration and functional decline in myelin diseases are often attributed to loss of myelin but their relation is not fully understood. Perturbed myelinating glia...
Axon degeneration and functional decline in myelin diseases are often attributed to loss of myelin but their relation is not fully understood. Perturbed myelinating glia can instigate chronic neuroinflammation and contribute to demyelination and axonal damage. Here we study mice with distinct defects in the proteolipid protein 1 gene that develop axonal damage which is driven by cytotoxic T cells targeting myelinating oligodendrocytes. We show that persistent ensheathment with perturbed myelin poses a risk for axon degeneration, neuron loss, and behavioral decline. We demonstrate that CD8 T cell-driven axonal damage is less likely to progress towards degeneration when axons are efficiently demyelinated by activated microglia. Mechanistically, we show that cytotoxic T cell effector molecules induce cytoskeletal alterations within myelinating glia and aberrant actomyosin constriction of axons at paranodal domains. Our study identifies detrimental axon-glia-immune interactions which promote neurodegeneration and possible therapeutic targets for disorders associated with myelin defects and neuroinflammation.
Topics: Animals; Mice; Axons; CD8-Positive T-Lymphocytes; Demyelinating Diseases; Microglia; Myelin Sheath; Neuroinflammatory Diseases
PubMed: 37903797
DOI: 10.1038/s41467-023-42570-2 -
Biomolecules Oct 2023The myelin sheath provides insulation to the brain's neuron cells, which aids in signal transmission and communication with the body. Degenerated myelin hampers the...
The myelin sheath provides insulation to the brain's neuron cells, which aids in signal transmission and communication with the body. Degenerated myelin hampers the connection between the glial cells, which are the front row responders during traumatic brain injury mitigation. Thus, the structural integrity of the myelin layer is critical for protecting the brain tissue from traumatic injury. At the molecular level, myelin consists of a lipid bilayer, myelin basic proteins (MBP), proteolipid proteins (PLP), water and ions. Structurally, the myelin sheath is formed by repeatedly wrapping forty or more myelin layers around an axon. Here, we have used molecular dynamic simulations to model and capture the tensile response of a single myelin layer. An openly available molecular dynamic solver, LAMMPS, was used to conduct the simulations. The interatomic potentials for the interacting atoms and molecules were defined using CHARMM force fields. Following a standard equilibration process, the molecular model was stretched uniaxially at a deformation rate of 5 Å/ps. We observed that, at around 10% applied strain, the myelin started to cohesively fail via flaw formation inside the bilayers. Further stretching led to a continued expansion of the defect inside the bilayer, both radially and transversely. This study provides the cellular-level mechanisms of myelin damage due to mechanical load.
Topics: Myelin Sheath; Neuroglia; Axons; Myelin Basic Protein; Lipid Bilayers
PubMed: 37892207
DOI: 10.3390/biom13101525 -
Scientific Reports Oct 2023The impact of high-intensity interval training (HIIT) on the central nervous system (CNS) in autoimmune neuroinflammation is not known. The aim of this study was to...
The impact of high-intensity interval training (HIIT) on the central nervous system (CNS) in autoimmune neuroinflammation is not known. The aim of this study was to determine the direct effects of HIIT on the CNS and development of experimental autoimmune encephalomyelitis (EAE). Healthy mice were subjected to HIIT by treadmill running and the proteolipid protein (PLP) transfer EAE model was utilized. To examine neuroprotection, PLP-reactive lymph-node cells (LNCs) were transferred to HIIT and sedentary (SED) mice. To examine immunomodulation, PLP-reactive LNCs from HIIT and SED donor mice were transferred to naïve recipients and analyzed in vitro. HIIT in recipient mice did not affect the development of EAE following exposure to PLP-reactive LNCs. HIIT mice exhibited enhanced migration of systemic autoimmune cells into the CNS and increased demyelination. In contrast, EAE severity in recipient mice injected with PLP-reactive LNCs from HIIT donor mice was significantly diminished. The latter positive effect was associated with decreased migration of autoimmune cells into the CNS and inhibition of very late antigen (VLA)-4 expression in LNCs. Thus, the beneficial effect of HIIT on EAE development is attributed solely to systemic immunomodulatory effects, likely because of systemic inhibition of autoreactive cell migration and reduced VLA-4 integrin expression.
Topics: Mice; Animals; Encephalomyelitis, Autoimmune, Experimental; High-Intensity Interval Training; Central Nervous System; Immunomodulation; Encephalomyelitis; Myelin Proteolipid Protein
PubMed: 37783693
DOI: 10.1038/s41598-023-43534-8