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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 -
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 -
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 -
Biomolecules Mar 2024Phosphatase and tensin homolog (Pten) is a key regulator of cell proliferation and a potential target to stimulate postnatal enteric neuro- and/or gliogenesis. To...
Phosphatase and tensin homolog (Pten) is a key regulator of cell proliferation and a potential target to stimulate postnatal enteric neuro- and/or gliogenesis. To investigate this, we generated two tamoxifen-inducible Cre recombinase murine models in which was conditionally ablated, (1) in glia (-expressing cells) and (2) in neurons (-expressing cells). Tamoxifen-treated adult (7-12 weeks of age; = 4-15) mice were given DSS to induce colitis, EdU to monitor cell proliferation, and were evaluated at two timepoints: (1) early (3-4 days post-DSS) and (2) late (3-4 weeks post-DSS). We investigated gut motility and evaluated the enteric nervous system. inhibition in -expressing cells elicited gliogenesis at baseline and post-DSS (early and late) in the colon, and neurogenesis post-DSS late in the proximal colon. They also exhibited an increased frequency of colonic migrating motor complexes (CMMC) and slower whole gut transit times. inhibition in -expressing cells did not induce enteric neuro- or gliogenesis, and no alterations were detected in CMMC or whole gut transit times when compared to the control at baseline or post-DSS (early and late). Our results merit further research into modulation where increased glia and/or slower intestinal transit times are desired (e.g., short-bowel syndrome and rapid-transit disorders).
Topics: Animals; Mice; Enteric Nervous System; Neurogenesis; Proteolipids; Tamoxifen; Tensins
PubMed: 38540765
DOI: 10.3390/biom14030346 -
International Journal of Molecular... Feb 2024Aquaporins (AQPs), membrane proteins responsible for facilitating water transport, found in plant membrane vesicles (MV), have been related to the functionality and...
Aquaporins (AQPs), membrane proteins responsible for facilitating water transport, found in plant membrane vesicles (MV), have been related to the functionality and stability of MV. We focused on AQPs obtained from broccoli, as they show potential for biotechnological applications. To gain further insight into the role of AQPs in MV, we describe the heterologous overexpression of two broccoli AQPs ( and ) in , resulting in their purification with high yield (0.14 and 0.99 mg per gram cells for BoPIP1;2 and BoPIP2;2). We reconstituted AQPs in liposomes to study their functionality, and the size of proteoliposomes did not change concerning liposomes. BoPIP2;2 facilitated water transport, which was preserved for seven days at 4 °C and at room temperature but not at 37 °C. BoPIP2;2 was incorporated into liposomes to encapsulate a resveratrol extract, resulting in increased entrapment efficiency (EE) compared to conventional liposomes. Molecular docking was utilized to identify binding sites in PIP2s for resveratrol, highlighting the role of aquaporins in the improved EE. Moreover, interactions between plant AQP and human integrin were shown, which may increase internalization by the human target cells. Our results suggest AQP-based alternative encapsulation systems can be used in specifically targeted biotechnological applications.
Topics: Humans; Liposomes; Resveratrol; Molecular Docking Simulation; Aquaporins; Brassica; Water; Proteolipids
PubMed: 38396666
DOI: 10.3390/ijms25041987 -
Biomimetic proteolipid vesicles for reverting GPI deficiency in paroxysmal nocturnal hemoglobinuria.IScience Mar 2024Nano-vesicular carriers are promising tissue-specific drug delivery platforms. Here, biomimetic proteolipid vesicles (BPLVs) were used for delivery of...
Nano-vesicular carriers are promising tissue-specific drug delivery platforms. Here, biomimetic proteolipid vesicles (BPLVs) were used for delivery of glycosylphosphatidylinositol (GPI)-anchored proteins to GPI deficient paroxysmal nocturnal hemoglobinuria (PNH) cells. BPLVs were assembled as single unilamellar monodispersed (polydispersity index, 0.1) negatively charged (ζ-potential, -28.6 ± 5.6 mV) system using microfluidic technique equipped with Y-shaped chip. GPI-anchored and not-GPI proteins on BPLV surface were detected by flow cytometry. Peripheral blood mononuclear cells (PBMCs) from healthy and PNH subjects were treated with BPLVs (final concentration, 0.5 mg/mL), and cells displayed an excellent protein uptake, documented by flow cytometry immunophenotyping and confocal microscopy. BPLV-treated cells stressed with complement components showed an increased resistance to complement-mediated lysis, both healthy and PNH PBMCs. In conclusion, BPLVs could be effective nanocarriers for protein transfer to targeted cells to revert protein deficiency, like in PNH disease. However, further studies are required to validate our preclinical results.
PubMed: 38361629
DOI: 10.1016/j.isci.2024.109021 -
Frontiers in Neuroanatomy 2024Brain banks provide small tissue samples to researchers, while gross anatomy laboratories could provide larger samples, including complete brains to neuroscientists....
BACKGROUND
Brain banks provide small tissue samples to researchers, while gross anatomy laboratories could provide larger samples, including complete brains to neuroscientists. However, they are preserved with solutions appropriate for gross-dissection, different from the classic neutral-buffered formalin (NBF) used in brain banks. Our previous work in mice showed that two gross-anatomy laboratory solutions, a saturated-salt-solution (SSS) and an alcohol-formaldehyde-solution (AFS), preserve antigenicity of the main cellular markers (neurons, astrocytes, microglia, and myelin). Our goal is now to compare the quality of histology and antigenicity preservation of human brains fixed with NBF by immersion (practice of brain banks) vs. those fixed with a SSS and an AFS by whole body perfusion, practice of gross-anatomy laboratories.
METHODS
We used a convenience sample of 42 brains (31 males, 11 females; 25-90 years old) fixed with NBF (N = 12), SSS (N = 13), and AFS (N = 17). One cm tissue blocks were cut, cryoprotected, frozen and sliced into 40 μm sections. The four cell populations were labeled using immunohistochemistry (Neurons = neuronal-nuclei = NeuN, astrocytes = glial-fibrillary-acidic-protein = GFAP, microglia = ionized-calcium-binding-adaptor-molecule1 = Iba1 and oligodendrocytes = myelin-proteolipid-protein = PLP). We qualitatively assessed antigenicity and cell distribution, and compared the ease of manipulation of the sections, the microscopic tissue quality, and the quality of common histochemical stains (e.g., Cresyl violet, Luxol fast blue, etc.) across solutions.
RESULTS
Sections of SSS-fixed brains were more difficult to manipulate and showed poorer tissue quality than those from brains fixed with the other solutions. The four antigens were preserved, and cell labeling was more often homogeneous in AFS-fixed specimens. NeuN and GFAP were not always present in NBF and SSS samples. Some antigens were heterogeneously distributed in some specimens, independently of the fixative, but an antigen retrieval protocol successfully recovered them. Finally, the histochemical stains were of sufficient quality regardless of the fixative, although neurons were more often paler in SSS-fixed specimens.
CONCLUSION
Antigenicity was preserved in human brains fixed with solutions used in human gross-anatomy (albeit the poorer quality of SSS-fixed specimens). For some specific variables, histology quality was superior in AFS-fixed brains. Furthermore, we show the feasibility of frequently used histochemical stains. These results are promising for neuroscientists interested in using brain specimens from anatomy laboratories.
PubMed: 38659652
DOI: 10.3389/fnana.2024.1372953 -
Journal of Autoimmunity Nov 2023Sensitization to self-peptides induces various immunological responses, from autoimmunity to tumor immunity, depending on the peptide sequence; however, the underlying...
Harnessing autoimmunity with dominant self-peptide: Modulating the sustainability of tissue-preferential antigen-specific Tregs by governing the binding stability via peptide flanking residues.
Sensitization to self-peptides induces various immunological responses, from autoimmunity to tumor immunity, depending on the peptide sequence; however, the underlying mechanisms remain unclear, and thus, curative therapeutic options considering immunity balance are limited. Herein, two overlapping dominant peptides of myelin proteolipid protein, PLP136-150 and PLP139-151, which induce different forms of experimental autoimmune encephalomyelitis (EAE), monophasic and relapsing EAE, respectively, were investigated. Mice with monophasic EAE exhibited highly resistant to EAE re-induction with any encephalitogenic peptides, whereas mice with relapsing EAE were susceptible, and progressed, to EAE re-induction. This resistance to relapse and re-induction in monophasic EAE mice was associated with the maintenance of potent CD69CD103CD4CD25 regulatory T-cells (Tregs) enriched with antigen specificity, which expanded preferentially in the central nervous system with sustained suppressive activity. This tissue-preferential sustainability of potent antigen-specific Tregs was correlated with the antigenicity of PLP136-150, depending on its flanking residues. That is, the flanking residues of PLP136-150 enable to form pivotally arranged strong hydrogen bonds that secured its binding stability to MHC-class II. These potent Tregs acting tissue-preferentially were induced only by sensitization of PLP136-150, not by its tolerance induction, independent of EAE development. These findings suggest that, for optimal therapy, "benign autoimmunity" can be critically achieved through inverse vaccination with self-peptides by manipulating their flanking residues.
Topics: Animals; T-Lymphocytes, Regulatory; Encephalomyelitis, Autoimmune, Experimental; Mice; Myelin Proteolipid Protein; Autoimmunity; Autoantigens; Female; Peptide Fragments; Protein Binding; Peptides; Disease Models, Animal; Mice, Inbred C57BL
PubMed: 37716077
DOI: 10.1016/j.jaut.2023.103094 -
Lung Jun 2024Acute respiratory distress syndrome (ARDS) is a major cause of hypoxemic respiratory failure in adults. In ARDS extensive inflammation and leakage of fluid into the...
PURPOSE
Acute respiratory distress syndrome (ARDS) is a major cause of hypoxemic respiratory failure in adults. In ARDS extensive inflammation and leakage of fluid into the alveoli lead to dysregulation of pulmonary surfactant metabolism and function. Altered surfactant synthesis, secretion, and breakdown contribute to the clinical features of decreased lung compliance and alveolar collapse. Lung function in ARDS could potentially be restored with surfactant replacement therapy, and synthetic surfactants with modified peptide analogues may better withstand inactivation in ARDS alveoli than natural surfactants.
METHODS
This study aimed to investigate the activity in vitro and the bolus effect (200 mg phospholipids/kg) of synthetic surfactant CHF5633 with analogues of SP-B and SP-C, or natural surfactant Poractant alfa (Curosurf, both preparations Chiesi Farmaceutici S.p.A.) in a severe ARDS model (the ratio of partial pressure arterial oxygen and fraction of inspired oxygen, P/F ratio ≤ 13.3 kPa) induced by hydrochloric acid instillation followed by injurious ventilation in adult New Zealand rabbits. The animals were ventilated for 4 h after surfactant treatment and the respiratory parameters, histological appearance of lung parenchyma and levels of inflammation, oxidative stress, surfactant dysfunction, and endothelial damage were evaluated.
RESULTS
Both surfactant preparations yielded comparable improvements in lung function parameters, reductions in lung injury score, pro-inflammatory cytokines levels, and lung edema formation compared to untreated controls.
CONCLUSIONS
This study indicates that surfactant replacement therapy with CHF5633 improves lung function and lung architecture, and attenuates inflammation in severe ARDS in adult rabbits similarly to Poractant alfa. Clinical trials have so far not yielded conclusive results, but exogenous surfactant may be a valid supportive treatment for patients with ARDS given its anti-inflammatory and lung-protective effects.
Topics: Animals; Rabbits; Respiratory Distress Syndrome; Pulmonary Surfactants; Lung; Phospholipids; Disease Models, Animal; Biological Products; Pulmonary Surfactant-Associated Protein B; Oxidative Stress; Pulmonary Surfactant-Associated Protein C; Male; Bronchoalveolar Lavage Fluid; Peptide Fragments; Phosphatidylcholines
PubMed: 38684519
DOI: 10.1007/s00408-024-00689-z -
Nutrients Aug 2023Human genetic studies have associated Neuronatin gene variants with anorexia nervosa (AN) and obesity. Studies on the expression of the Neuronatin gene product, a...
Human genetic studies have associated Neuronatin gene variants with anorexia nervosa (AN) and obesity. Studies on the expression of the Neuronatin gene product, a proteolipid, are lacking. We investigated the relationship between circulating Neuronatin, body mass index (BMI), body composition (BC), physical activity (PA), and psychometric outcomes in patients with AN, normal weight, and obesity. Plasma Neuronatin was measured by ELISA in (1) 79 subjects of five BMI categories (AN/BMI < 17.5 kg/m; normal weight/BMI 18.5-25 kg/m; obesity/BMI 30-40 kg/m; obesity/BMI 40-50 kg/m; obesity/BMI > 50 kg/m) with assessment of BC (bioimpedance analysis; BIA); (2) 49 women with AN (BMI 14.5 ± 1.8 kg/m) with measurements of BC (BIA) and PA (accelerometry); (3) 79 women with obesity (BMI 48.8 ± 7.8 kg/m) with measurements of anxiety (GAD-7), stress (PSQ-20), depression (PHQ-9) and eating behavior (EDI-2). Overall, a positive correlation was found between Neuronatin and BMI ( = 0.006) as well as total fat mass (FM; = 0.036). In AN, Neuronatin did not correlate with BMI, FM, or PA ( > 0.05); no correlations were found between Neuronatin and psychometric outcomes in obesity ( > 0.05). The findings suggest an FM-dependent peripheral Neuronatin expression. The decreased Neuronatin expression in AN provides evidence that Neuronatin is implicated in the pathogenesis of eating disorders.
Topics: Humans; Female; Body Mass Index; Accelerometry; Anorexia Nervosa; Obesity; Adipose Tissue
PubMed: 37630847
DOI: 10.3390/nu15163657