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Toxicology Research Feb 2024Acrylamide is an alkene known to induce neurotoxicity in humans and experimental animals. However, the effects of acrylamide on the development of myelin sheath are...
Acrylamide is an alkene known to induce neurotoxicity in humans and experimental animals. However, the effects of acrylamide on the development of myelin sheath are unclear. The present study was to explore the effects of acrylamide exposure during pregnancy and lactation on the development of myelin sheath in offspring rats. Four groups of thirty-two pregnant Sprague-Dawley rats were exposed to 0, 4.5, 9 and 18 mg/kg BW acrylamide by gavage from gestational day 15 to postnatal day 13. The corpus callosum of nine offspring rats per group were dissected in postpartum day 14. Structural changes and lipid contents in myelin sheaths were examined by transmission electron microscopy(TEM) and Luxol Fast Blue staining(LFB). The expression of MBP and PLP was evaluated by immunohistochemistry and Western blotting. TEM showed that the myelin sheaths in the 18 mg/kg group were disordered compared with control group. Luxol Fast Blue staining gradually decreased with increasing acrylamide maternal exposure. The immunohistochemistry and Western Blotting results showed that maternal exposure to acrylamide caused a decreasing trend in MBP and PLP in the corpus callosum of rats at postnatal day 14. Furthermore, these reduced protein levels may be neurodevelopmental toxicity's mechanism in response to maternal exposure to acrylamide.
PubMed: 38314039
DOI: 10.1093/toxres/tfae014 -
Stem Cell Research Mar 2024Human brain organoids can serve as models to study myelination, a process orchestrated by oligodendrocytes. Real-time imaging provides new insights on the communication...
Human brain organoids can serve as models to study myelination, a process orchestrated by oligodendrocytes. Real-time imaging provides new insights on the communication of oligodendrocytes with neurons as well as demyelination processes in patient derived organoids. PLP1, a prominent myelin protein within the central nervous system, is associated with demyelinating diseases, such as Pelizaeus-Merzbacher. In this study, we generated a stable PLP1-Citrine reporter line (fPLP1) in human induced pluripotent stem cells (iPSCs) by CRISPR/Cas9 editing. fPLP1 facilitates visualization of PLP1 expression in living brain organoids, allowing time-lapse imaging of pre-myelinating and myelinating oligodendrocytes.
Topics: Humans; Myelin Proteolipid Protein; Induced Pluripotent Stem Cells; Pelizaeus-Merzbacher Disease; Myelin Sheath; Oligodendroglia
PubMed: 38219302
DOI: 10.1016/j.scr.2023.103295 -
Journal of Biomolecular Structure &... Mar 2024Enterotoxaemia (ET) is a severe disease that affects domestic ruminants, including sheep and goats, and is caused by type B and D strains. The disease is characterized...
Enterotoxaemia (ET) is a severe disease that affects domestic ruminants, including sheep and goats, and is caused by type B and D strains. The disease is characterized by the production of Epsilon toxin (ETX), which has a significant impact on the farming industry due to its high lethality. The binding of ETX to the host cell receptor is crucial, but still poorly understood. Therefore, the structural features of goat Myelin and lymphocytic (MAL) protein were investigated and defined in this study. We induced the mutations in aromatic amino acid residues of ETX and substituted them with aliphatic residues at domains I and II. Subsequently, protein-protein interactions (PPI) were performed between ETX (wild)-MAL and ETX (mutated)-MAL protein predicting the domain sites of ETX structure. Further, molecular dynamics (MD) simulation studies were performed for both complexes to investigate the dynamic behavior of the proteins. The binding efficiency between 'ETX (wild)-MAL protein' and 'ETX (mutated)-MAL protein complex' interactions were compared and showed that the former had stronger interactions and binding efficiency due to the higher stability of the complex. The MD analysis showed destabilization and higher fluctuations in the PPI of the mutated heterodimeric ETX-MAL complex which is otherwise essential for its functional conformation. Such kind of interactions with mutated functional domains of ligands provided much-needed clarity in understanding the pre-pore complex formation of epsilon toxin with the MAL protein receptor of goats. The findings from this study would provide an impetus for designing a novel vaccine for Enterotoxaemia in goats.Communicated by Ramaswamy H. Sarma.
Topics: Animals; Amino Acids; Clostridium perfringens; Enterotoxemia; Goats; Lymphocytes; Mutation; Myelin Proteins; Myelin Sheath; Myelin and Lymphocyte-Associated Proteolipid Proteins; Bacterial Toxins
PubMed: 37129165
DOI: 10.1080/07391102.2023.2204362 -
Internal Medicine (Tokyo, Japan) Sep 2023Mutations in the surfactant protein C gene (SFTPC) are responsible for hereditary interstitial lung disease (ILD), which is a rare disease. We herein report a patient...
Mutations in the surfactant protein C gene (SFTPC) are responsible for hereditary interstitial lung disease (ILD), which is a rare disease. We herein report a patient with a clinical history of endogenous lipoid pneumonia in infancy who developed diffuse progressive pulmonary fibrosis in adulthood associated with SFTPC mutations. A surgical lung biopsy and genetic sequencing revealed fibrotic interstitial pneumonia and two SFTPC mutations (c.215G>A and c.578C>A). Based on these findings, we diagnosed the series of lung diseases as sporadic ILD caused by SFTPC mutations. Physicians should suggest genetic sequencing in patients with early-onset ILD.
Topics: Humans; Infant; Lung Diseases, Interstitial; Mutation; Pneumonia, Lipid; Protein C; Pulmonary Fibrosis; Pulmonary Surfactant-Associated Protein C; Surface-Active Agents
PubMed: 36642519
DOI: 10.2169/internalmedicine.0980-22 -
Microbial Drug Resistance (Larchmont,... May 2024Invasive fungal infections in humans with compromised immune systems are the primary cause of morbidity and mortality, which is becoming more widely acknowledged....
Invasive fungal infections in humans with compromised immune systems are the primary cause of morbidity and mortality, which is becoming more widely acknowledged. Amphotericin B (AmB) is one of the antifungal drugs used to treat such infections. AmB binds with plasma membrane ergosterol, inducing cellular ions to leak and causing cell death. Reduction in ergosterol content and modification of cell walls have been described as AmB resistance mechanisms. In addition, when the sphingolipid level is decreased, the cell becomes more susceptible to AmB. Previously, , a gene that encodes phosphatidylinositol transfer protein in , was shown to enhance AmB resistance upon overexpression. However, the mechanism of -mediated AmB resistance is not clear. Here, in this study, it was discovered that a plasma membrane proteolipid 3 protein encoded by is essential for -mediated AmB resistance. -mediated AmB resistance does not depend on ergosterol, but a functional sphingolipid biosynthetic pathway is required. Additionally, mediated alteration in membrane integrity abolishes mediated AmB resistance, confirming the importance of in the mediated AmB resistance.
PubMed: 38727600
DOI: 10.1089/mdr.2024.0008 -
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 -
Translational Psychiatry Jan 2024Tuberous sclerosis complex (TSC) is a genetic disease that causes benign tumors and dysfunctions in many organs, including the brain. Aside from the brain malformations,...
Tuberous sclerosis complex (TSC) is a genetic disease that causes benign tumors and dysfunctions in many organs, including the brain. Aside from the brain malformations, many individuals with TSC exhibit neuropsychiatric symptoms. Among these symptoms, autism spectrum disorder (ASD) is one of the most common co-morbidities, affecting up to 60% of the population. Past neuroimaging studies strongly suggested that the impairments in brain connectivity contribute to ASD, whether or not TSC-related. Specifically, the tract-based diffusion tensor imaging (DTI) analysis provides information on the fiber integrity and has been used to study the neuropathological changes in the white matter of TSC patients with ASD symptoms. In our previous study, curcumin, a diet-derived mTOR inhibitor has been shown to effectively mitigate learning and memory deficits and anxiety-like behavior in Tsc2 mice via inhibiting astroglial proliferation. Recently, gut microbiota, which is greatly influenced by the diet, has been considered to play an important role in regulating several components of the central nervous system, including glial functions. In this study, we showed that the abnormal social behavior in the Tsc2 mice can be ameliorated by the dietary curcumin treatment. Second, using tract-based DTI analysis, we found that the Tsc2 mice exhibited altered fractional anisotropy, axial and radial diffusivities of axonal bundles connecting the prefrontal cortex, nucleus accumbens, hypothalamus, and amygdala, indicating a decreased brain network. Third, the dietary curcumin treatment improved the DTI metrics, in accordance with changes in the gut microbiota composition. At the bacterial phylum level, we showed that the abundances of Actinobacteria, Verrucomicrobia, and Tenericutes were significantly correlated with the DTI metrics FA, AD, and RD, respectively. Finally, we revealed that the expression of myelin-associated proteins, myelin bassic protein (MBP) and proteolipid protein (PLP) was increased after the treatment. Overall, we showed a strong correlation between structural connectivity alterations and social behavioral deficits, as well as the diet-dependent changes in gut microbiota composition.
Topics: Humans; Mice; Animals; Diffusion Tensor Imaging; Autism Spectrum Disorder; Tuberous Sclerosis; Gastrointestinal Microbiome; Curcumin; Brain
PubMed: 38296969
DOI: 10.1038/s41398-024-02752-y -
Cellular Signalling Jun 2024Diabetes-associated periodontitis (DP) presents severe inflammation and resistance to periodontal conventional treatment, presenting a significant challenge in clinical...
Diabetes-associated periodontitis (DP) presents severe inflammation and resistance to periodontal conventional treatment, presenting a significant challenge in clinical management. In this study, we investigated the underlying mechanism driving the hyperinflammatory response in gingival epithelial cells (GECs) of DP patients. Our findings indicate that lysosomal dysfunction under high glucose conditions leads to the blockage of autophagy flux, exacerbating inflammatory response in GECs. Single-cell RNA sequencing and immunohistochemistry analyses of clinical gingival epithelia revealed dysregulation in the lysosome pathway characterized by reduced levels of lysosome-associated membrane glycoprotein 2 (LAMP2) and V-type proton ATPase 16 kDa proteolipid subunit c (ATP6V0C) in subjects with DP. In vitro stimulation of human gingival epithelial cells (HGECs) with a hyperglycemic microenvironment showed elevated release of proinflammatory cytokines, compromised lysosomal acidity and blocked autophagy. Moreover, HGECs with deficiency in ATP6V0C demonstrated impaired autophagy and heightened inflammatory response, mirroring the effects of high glucose stimulation. Proteomic analysis of acetylation modifications identified altered acetylation levels in 28 autophagy-lysosome pathway-related proteins and 37 sites in HGECs subjected to high glucose stimulation or siATP6V0C. Overall, our finding highlights the pivotal role of lysosome impairment in autophagy obstruction in DP and suggests a potential impact of altered acetylation of relevant proteins on the interplay between lysosome dysfunction and autophagy blockage. These insights may pave the way for the development of effective therapeutic strategies against DP.
PubMed: 38950874
DOI: 10.1016/j.cellsig.2024.111273 -
Stem Cell Research Feb 2024Genetic alterations in the PLP1 gene, i.e. point mutations and duplications, are associated with demyelinating disease Pelizaeus-Merzbacher. Here, we describe the...
Genetic alterations in the PLP1 gene, i.e. point mutations and duplications, are associated with demyelinating disease Pelizaeus-Merzbacher. Here, we describe the generation of a human iPSC line harboring a PLP1 variant in codon 33 which leads to an amino acid change from cysteine to tyrosine. The established PLP1 iPSC line enables the study of PMD pathophysiology by investigating various cell types and -characteristics in our developed protocol for bioengineered neuronal organoids (BENOs).
Topics: Humans; Pelizaeus-Merzbacher Disease; Myelin Proteolipid Protein; Induced Pluripotent Stem Cells; Gene Editing; CRISPR-Cas Systems; Mutation
PubMed: 38104430
DOI: 10.1016/j.scr.2023.103276 -
Frontiers in Genetics 2024Hereditary neurodevelopmental disorders (NDDs) are prevalent in poorly prognostic pediatric diseases, but the pathogenesis of NDDs is still unclear. Irregular...
BACKGROUND
Hereditary neurodevelopmental disorders (NDDs) are prevalent in poorly prognostic pediatric diseases, but the pathogenesis of NDDs is still unclear. Irregular myelination could be one of the possible causes of NDDs.
CASE PRESENTATION
Here, whole exome sequencing was carried out for a consanguineous Pakistani family with NDDs to identify disease-associated variants. The co-segregation of candidate variants in the family was validated using Sanger sequencing. The potential impact of the gene on NDDs has been supported by conservation analysis, protein prediction, and expression analysis. A novel homozygous variant was identified. It was concluded that the missense variant might affect the protein-protein binding sites of the critical MEC interaction region of DOP1A, and DOP1A-MON2 may cause stability deficits in Golgi-endosome protein traffic. Proteolipid protein (PLP) and myelin-associate glycoprotein (MAG) could be targets of the DOP1A-MON2 Golgi-endosome traffic complex, especially during the fetal stage and the early developmental stages. This further supports the perspective that disorganized myelinogenesis due to congenital deficiency might cause neurodevelopmental disorders (NDDs).
CONCLUSION
Our case study revealed the potential pathway of myelinogenesis-relevant NDDs and identified as a potential NDDs-relevant gene in humans.
PubMed: 38818041
DOI: 10.3389/fgene.2024.1351710