Myelin sheath and cyanobacterial thylakoids as concentric multilamellar structures with similar bioenergetic properties

There is a surprisingly high morphological similarity between multilamellar concentric thylakoids in cyanobacteria and the myelin sheath that wraps the nerve axons. Thylakoids are multilamellar structures, which express photosystems I and II, cytochromes and ATP synthase necessary for the light-dependent reaction of photosynthesis. Myelin is a multilamellar structure that surrounds many axons in the nervous system and has long been believed to act simply as an insulator. However, it has been shown that myelin has a trophic role, conveying nutrients to the axons and producing ATP through oxidative phosphorylation. Therefore, it is tempting to presume that both membranous structures, although distant in the evolution tree, share not only a morphological but also a functional similarity, acting in feeding ATP synthesized by the ATP synthase to the centre of the multilamellar structure. Therefore, both molecular structures may represent a convergent evolution of life on Earth to fulfill fundamentally similar functions.

Comparative Phosphoproteomic Profiling in Prefrontal Cortex of Prenatal Stressed Offspring Rats

Background: Many investigations indicate that prenatal stress caused depressive-like disturbances in offspring rats. The underlying pathogenic mechanisms have not yet been fully unravelled. The PFC has been shown to play a role in susceptibility to stress during fetal, thus we focus our attention on differential protein phosphorylation in this region of PS-S(Susceptibility to PS) offspring rats.Method: SPT was used to screen for susceptibility to PS. The validity of prenatally stressed model was verified by other common depression-like behaviors. We used MS-based TMT quantitative proteomics in combination with phosphopeptide enrichment method to compare phosphoproteomic profiling in prefrontal cortex of of PS-S and CON offspring rats. Results: Totally, 3418 phosphoproteins, 8404 phosphopeptides and 12175 phosphosites were identified in this analysis. According to the screening criteria, 902 phosphopeptides increased and 609 decreased in the PFC of PS-S group compared to the control rats. GO enrichment analysis indicated that the main enriched terms in CC category were ‘synapse part’, ‘myelin sheath’, ‘synapse’, ‘neuron part’ and ‘axon’. The phosphorproteins enriched in MF and BP category were mainly related to cytoskeleton and projection morphogenesis associated proteins. KEGG pathway enrichment analyses identified 30 significant KEGG pathways, the top five pathways included salivary secretion, Endocrine and other factor-regulated calcium reabsorption, Pancreatic secretion and Insulin secretion. Motifs such as......_S_P...RR, ......_S_PE...., ......_S_PV...., ......_S_P.H...and ..S..._S_PT....were the top five motifs enriched in phosphorylated sites.Conclusion: PS may induce depressive-like behaviors in offspring rats through regulating the phosphorylation of protein mainly related to synapse, myelin sheath, neuron and cytoskeleton. And the phosphorylation of related proteins may act as key pathogenic hits. Data are available via ProteomeXchange with identifier PXD026563.

Recurrent Bilateral Optic Neuritis Associated with Myelin Oligodendrocyte Glycoprotein Antibody: A Case Report from Nepal

Neuromyelitis optica spectrum disorder (NMOSD) is an immune-mediated inflammatory condition involving spinal cord and optic nerves. Diagnosis of NMOSD is done by aquaporin-4 antibody (AQP4) in patients with optic neuritis. Myelin oligodendrocyte glycoprotein (MOG) expressed on the oligodendrocyte cell surface and on the outermost cell surface of the myelin sheath may also be present in patients with NMOSD bilateral optic neuritis. Here, we describe a case of a thirty-nine-year-old-female with recurrent bilateral optic neuritis with positive anti-MOG antibody, and anti-MOG syndrome has not previously been reported from Nepal.

Intranasal delivery of human oligodendrocyte precursor cells enhances regenerative effects in premature rat brain following hypoxic–ischemic injury

Background White matter injury is a common ischemic brain injury in premature infants and for which there is no effective treatment. Stem cell transplantation has emerged as a novel approach for replacing damaged brain tissues and promoting regenerative processes. Since intracerebral transplantation is not clinically feasible for premature infants, intranasal delivery of cells to the brain is a promising, noninvasive therapeutic approach for restoring the damaged brain. This study was conducted to investigate whether transplanted human oligodendrocyte progenitor cells exhibit neuroprotective effects in a rat model of WMI in premature infants. Methods SD rats aged 3 days were randomly divided into sham group, preterm white matter injury group and nasal transplantation group. Hypoxia–ischemia was induced in 3-day-old rat pups by right carotid artery ligation, followed by exposure to 6% oxygen for 90 min. Rats were intranasally administered the cell suspension (250,000 cells in 6 µL) twice in each nostril (1 × 106 cells total), and myelin basic protein immunofluorescence staining and transmission electron microscopy were performed to assess endogenous myelin growth in the right hemispheres. Behavioral tests, including the Morris water maze, adhesive-removal test, and cylinder rearing test, as well as a gait test, were performed to evaluate the therapeutic effects at 12 weeks after transplantation. Results The cells transplanted from the nose can enter brain tissue of rats 3 days after transplantation. The myelin sheath structure was more compact and the myelin sheath thickness was increased. The nerve function defect was improved 12 weeks after transplantation. Conclusions The intranasal administration of human oligodendrocyte progenitor cells had beneficial therapeutic effects on rehabilitation of the rat hypoxia-ischemia model. This technique is a potential strategy for applying oligodendrocyte progenitor cells in transplantation therapy against white matter injury.