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Fish & Shellfish Immunology Nov 2023NK-lysins are one of the most abundant antimicrobial peptides produced by cytotoxic T lymphocytes (CTLs) and natural killer cells (NKs), and identified as a new class of...
NK-lysins are one of the most abundant antimicrobial peptides produced by cytotoxic T lymphocytes (CTLs) and natural killer cells (NKs), and identified as a new class of intrinsically disordered proteins, playing critical roles in the cell-mediated cytotoxicity response, as well as immunomodulatory and antimicrobial activities upon a significant range of pathogens. In the present study, an NK-lysin was identified from Obscure puffer Takifugu obscurus (ToNK-lysin). The open reading frame of ToNK-lysin sequence spans 423 bp, encoding a peptide with 140 amino acids which shares a moderate residue identity (18%-60%) with NK-lysin of mammals and other teleost species. Phylogenetic analysis revealed that ToNK-lysin was most closely related to NK-lysins from the Pleuronectiformes (Bastard halibut Paralichthys olivaceus and Pacific halibut Hippoglossus stenolepis). Comprehensive computational analysis revealed that ToNK-lysin have substantial level of intrinsic disorder, which might be contribute to its multifunction. The transcripts of the ToNK-lysin were detected in multiple examined tissues and most abundant in gills. After bacterial and Poly I:C challenge, the transcriptional levels of ToNK-lysin were significantly up-regulated in the head kidney, liver and spleen at different time points. The recombinant ToNK-lysin showed significant antibacterial activity against Vibrio harveyi and Escherichia coli, and the ToNK-lysin treatment not only reduced the bacterial loads in liver and head kidney, but also alleviated the pathogen-mediated upregulation of immune-related genes. In addition, the co-incubation with rToNK-lysin protein remarkably degraded bacterial genomic DNA, suggesting the potential mechanism of ToNK-lysin against microbes. These results suggest that ToNK-lysin possess antibacterial and immunoregulatory function both in vivo and in vitro, which may allow it a potential applicability to the aquaculture industry.
Topics: Animals; Amino Acid Sequence; Phylogeny; Anti-Bacterial Agents; Adjuvants, Immunologic; Immunologic Factors; Tetraodontiformes; Proteolipids; Mammals
PubMed: 37748586
DOI: 10.1016/j.fsi.2023.109080 -
Clinical Case Reports Sep 2023This study aimed to characterize the clinical features, developmental milestones, and the natural history of Pelizaeus-Merzbacher disease (PMD) associated with gene...
This study aimed to characterize the clinical features, developmental milestones, and the natural history of Pelizaeus-Merzbacher disease (PMD) associated with gene duplications. The study examined 16 PMD Patients ranging in age from 7 to 48 years, who had a documented gene duplication. The study examined and analyzed the medical and developmental histories of the subjects utilizing a combination of resources that included medical history questionnaires, medical record reviews, and a 31-point functional disability scale that had been previously validated. The data extracted from the medical records and questionnaires for analysis included information related to medical and developmental histories, level of ambulation and cognition, and degree of functional disability. The summation of findings among the study population demonstrated that the presenting symptoms, developmental milestones achieved, and progression of symptoms reported are consistent with many previous studies of patients with duplications. All patients exhibited onset within the first year of life, with nystagmus predominating as the first symptom noticed. All patients exhibited delays in both motor and language development; however, many individuals were able to meet several developmental milestones. They exhibited some degree of continued motor impairment with none having the ability to walk independently. All patients were able to complete at least some of the cognition achievements and although not all were verbal, a number were able to use communication devices to complete these tasks. A critical tool of the study was the functional disability scale which provided a major advantage in helping quantify the clinical course of PMD, and for several, we were able to gather this information at more than one point in time. These reported findings in our cohort contribute important insight into the clinical heterogeneity and potential underlying mechanisms that define the molecular pathogenesis of the disease. This is one of only a small number of natural history studies examining the clinical course of a cohort of patients with duplications within the context of a validated functional disability scoring system. This study is unique in that it is limited to subjects with gene duplications. This study demonstrated many commonalities to other studies that have characterized the features of PMD and other PLP1-related disorders but also provide significant new insights into the evolving story that marks the natural history.
PubMed: 37636890
DOI: 10.1002/ccr3.7814 -
Science Immunology Oct 2023Curated expression of proteolipid protein 1 (PLP1) is essential for multiple sclerosis-derived autoantibody recognition.
Curated expression of proteolipid protein 1 (PLP1) is essential for multiple sclerosis-derived autoantibody recognition.
Topics: Humans; Myelin Proteolipid Protein; Multiple Sclerosis
PubMed: 37801515
DOI: 10.1126/sciimmunol.adl0618 -
Frontiers in Bioscience (Landmark... Aug 2023Plasmolipin (PLLP) is a membrane protein located in lipid rafts that participates in the formation of myelin. It is also implicated in many pathologies, such as...
BACKGROUND
Plasmolipin (PLLP) is a membrane protein located in lipid rafts that participates in the formation of myelin. It is also implicated in many pathologies, such as neurological disorders, type 2 diabetes, and cancer metastasis. To better understand how PLLP interacts with raft components (gangliosides and cholesterol), we undertook a global study combining simulations and physicochemical measurements of molecular interactions in various PLLP-ganglioside systems.
METHODS
studies consisted of molecular dynamics simulations in reconstructed membrane environments. PLLP-ganglioside interaction measurements were performed by microtensiometry at the water-air interface on ganglioside monolayers.
RESULTS
We have elucidated the mode of interaction of PLLP with ganglioside GM1 and characterized this interaction at the molecular level. We showed that GM1 induces the structuring of the extracellular loops of PLLP and that this interaction propagates a conformational signal through the plasma membrane, involving a cholesterol molecule located between transmembrane domains. This conformational wave is finally transmitted to the intracellular domain of the protein, consistent with the role of PLLP in signal transduction.
CONCLUSIONS
This study is a typical example of the epigenetic dimension of protein structure, a concept developed by our team to describe the chaperone effect of gangliosides on disordered protein motifs which associate with lipid rafts. From a physiological point of view, these data shed light on the role of gangliosides in myelin formation. From a pathological point of view, this study will help to design innovative therapeutic strategies focused on ganglioside-PLLP interactions in various PLLP-associated diseases.
Topics: Humans; G(M1) Ganglioside; Gangliosides; Membrane Microdomains; Myelin Sheath; Proteolipids; Myelin and Lymphocyte-Associated Proteolipid Proteins
PubMed: 37664934
DOI: 10.31083/j.fbl2808157 -
Pediatric Pulmonology Feb 2024
Topics: Infant; Humans; Pulmonary Surfactant-Associated Protein C; Mutation
PubMed: 38038158
DOI: 10.1002/ppul.26722 -
Biochimica Et Biophysica Acta.... Mar 2024NK-2 is an antimicrobial peptide derived from helices 3 and 4 of the pore-forming protein of natural killer cells, NK-lysin. It has potent activities against... (Review)
Review
Structural analysis of the NK-lysin-derived peptide NK-2 upon interaction with bacterial membrane mimetics consisting of phosphatidylethanolamine and phosphatidylglycerol.
NK-2 is an antimicrobial peptide derived from helices 3 and 4 of the pore-forming protein of natural killer cells, NK-lysin. It has potent activities against Gram-negative and Gram-positive bacteria, fungi and protozoan parasites without being toxic to healthy human cells. In biophysical assays its membrane activities were found to require phosphatidylglycerol (PG) and phosphatidylethanolamine (PE), lipids which dominate the composition of bacterial membranes. Here the structure and activities of NK-2 in binary mixtures of different PE/PG composition were investigated. CD spectroscopy reveals that a threshold concentration of 50 % PG is needed for efficient membrane association of NK-2 concomitant with a random coil - helix transition. Association with PE occurs but is qualitatively different when compared to PG membranes. Oriented solid-state NMR spectroscopy of NK-2 specifically labelled with N indicates that the NK-2 helices are oriented parallel to the PG bilayer surface. Upon reduction of the PG content to 20 mol% interactions are weaker and/or an in average more tilted orientation is observed. Fluorescence spectroscopy of differently labelled lipids is in agreement of an interfacial localisation of both helices where the C-terminal end is in a less hydrophobic environment. By inserting into the membrane interface and interacting differently with PE and PG the peptides probably induce high curvature strain which result in membrane openings and rupture.
Topics: Humans; Lipid Bilayers; Phosphatidylethanolamines; Phosphatidylglycerols; Peptides; Proteolipids; 2,4-Dichlorophenoxyacetic Acid
PubMed: 38159877
DOI: 10.1016/j.bbamem.2023.184267 -
Journal of Immunology (Baltimore, Md. :... Sep 2023The pathogenic role B cells play in multiple sclerosis is underscored by the success of B cell depletion therapies. Yet, it remains unclear how B cells contribute to...
The pathogenic role B cells play in multiple sclerosis is underscored by the success of B cell depletion therapies. Yet, it remains unclear how B cells contribute to disease, although it is increasingly accepted that mechanisms beyond Ab production are involved. Better understanding of pathogenic interactions between B cells and autoreactive CD4 T cells will be critical for novel therapeutics. To focus the investigation on B cell:CD4 T cell interactions in vivo and in vitro, we previously developed a B cell-dependent, Ab-independent experimental autoimmune encephalomyelitis (EAE) mouse model driven by a peptide encompassing the extracellular domains of myelin proteolipid protein (PLPECD). In this study, we demonstrate that B cell depletion significantly inhibited PLPECD-induced EAE disease, blunted PLPECD-elicited delayed-type hypersensitivity reactions in vivo, and reduced CD4 T cell activation, proliferation, and proinflammatory cytokine production. Further, PLPECD-reactive CD4 T cells sourced from B cell-depleted donor mice failed to transfer EAE to naive recipients. Importantly, we identified B cell-mediated Ag presentation as the critical mechanism explaining B cell dependence in PLPECD-induced EAE, where bone marrow chimeric mice harboring a B cell-restricted MHC class II deficiency failed to develop EAE. B cells were ultimately observed to restimulate significantly higher Ag-specific proliferation from PLP178-191-reactive CD4 T cells compared with dendritic cells when provided PLPECD peptide in head-to-head cultures. We therefore conclude that PLPECD-induced EAE features a required pathogenic B cell-mediated Ag presentation function, providing for investigable B cell:CD4 T cell interactions in the context of autoimmune demyelinating disease.
Topics: Mice; Animals; Multiple Sclerosis; Antigen Presentation; Myelin-Oligodendrocyte Glycoprotein; Encephalomyelitis, Autoimmune, Experimental; CD4-Positive T-Lymphocytes; Myelin Proteolipid Protein; Antibodies
PubMed: 37548478
DOI: 10.4049/jimmunol.2200721 -
Molecular Biology Reports Dec 2023The Proteolipid Protein 2 (PLP2), a protein in the Endoplasmic Reticulum (ER) membrane, has been reported to be highly expressed in various tumors. Previous studies have...
BACKGROUND
The Proteolipid Protein 2 (PLP2), a protein in the Endoplasmic Reticulum (ER) membrane, has been reported to be highly expressed in various tumors. Previous studies have demonstrated that the reduced PLP2 can induce apoptosis and autophagy through ER stress-related pathways, leading to a decreased proliferation and aggressiveness. However, there is no research literature on the role of PLP2 in Acute Myeloid Leukemia (AML).
METHODS
PLP2 expression, clinical data, genetic mutations, and karyotype changes from GEO, TCGA, and timer2.0 databases were analyzed through the R packages. The possible functions and pathways of cells were explored through GO, KEGG, and GSEA enrichment analysis using the clusterProfiler R package. Immuno-infiltration analysis was conducted using the Cibersort algorithm and the Xcell R package. RT-PCR and western blot techniques were employed to identify the PLP2 expression, examine the knockdown effects in THP-1 cells, and assess the expression of genes associated with endoplasmic reticulum stress and apoptosis. Flow cytometry was utilized to determine the apoptosis and survival rates of different groups.
RESULTS
PLP2 expression was observed in different subsets of AML and other cancers. Enrichment analyses revealed that PLP2 was involved in various tumor-related biological processes, primarily apoptosis and lysosomal functions. Additionally, PLP2 expression showed a strong association with immune cell infiltration, particularly monocytes. In vitro, the knockdown of PLP2 enhanced endoplasmic reticulum stress-related apoptosis and increased drug sensitivity in THP-1 cells.
CONCLUSIONS
PLP2 could be a novel therapeutic target in AML, in addition, PLP2 is a potential endoplasmic reticulum stress regulatory gene in AML.
Topics: Humans; Apoptosis; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Leukemia, Myeloid, Acute; Proteolipids
PubMed: 38085372
DOI: 10.1007/s11033-023-08994-1 -
Journal of Cell Science Mar 2024Tricellular junctions (TCJs) seal epithelial cell vertices and are essential for tissue integrity and physiology, but how TCJs are assembled and maintained is poorly...
Tricellular junctions (TCJs) seal epithelial cell vertices and are essential for tissue integrity and physiology, but how TCJs are assembled and maintained is poorly understood. In Drosophila, the transmembrane proteins Anakonda (Aka, also known as Bark), Gliotactin (Gli) and M6 organize occluding TCJs. Aka and M6 localize in an interdependent manner to vertices and act jointly to localize Gli, but how these proteins interact to assemble TCJs was not previously known. Here, we show that the proteolipid protein M6 physically interacts with Aka and with itself, and that M6 is palmitoylated on conserved juxta-membrane cysteine residues. This modification promotes vertex localization of M6 and binding to Aka, but not to itself, and becomes essential when TCJ protein levels are reduced. Abolishing M6 palmitoylation leads to delayed localization of M6 and Aka but does not affect the rate of TCJ growth or mobility of M6 or Aka. Our findings suggest that palmitoylation-dependent recruitment of Aka by M6 promotes initiation of TCJ assembly, whereas subsequent TCJ growth relies on different mechanisms that are independent of M6 palmitoylation.
Topics: Animals; Drosophila; Drosophila melanogaster; Drosophila Proteins; Intercellular Junctions; Lipoylation; Proteolipids
PubMed: 38345097
DOI: 10.1242/jcs.261916 -
Blood Research Sep 2023Epigenetic studies, particularly research on microRNA (miRNA), have flourished. The abnormal expression of miRNA contributes to the development of hematologic...
BACKGROUND
Epigenetic studies, particularly research on microRNA (miRNA), have flourished. The abnormal expression of miRNA contributes to the development of hematologic malignancies. miR-765 has been reported to inhibit cell proliferation by downregulating proteolipid protein 2 (PLP2), which causes apoptosis. We investigated miR-765 dysregulation in myelodysplastic syndromes (MDS).
METHODS
We compared the expression profiles of miR-765 in 65 patients with MDS and 11 controls. Cell proliferation and apoptosis assays were performed to determine the effects of miR-765 on leukemia cells transfected with the miR-765 mimic. Reverse transcription quantitative PCR (RT-qPCR) and western blotting were performed to examine the targets of miR-765.
RESULTS
We found that miR-765 levels were upregulated 10.2-fold in patients with MDS compared to controls. In refractory cytopenia with multilineage dysplasia, the percentage of patients with elevated miR-765 levels was significantly higher than in other forms of MDS. Experiments with leukemia cells revealed that transfection with a miR-765 mimic inhibited cell proliferation and induced apoptosis. RT-qPCR and western blotting demonstrated that the target of miR-765 was PLP2.
CONCLUSION
These findings imply that upregulation of miR-765 induces apoptosis via downregulation of PLP2 and may have a role in MDS pathogenesis.
PubMed: 37495419
DOI: 10.5045/br.2023.2023097