NeuroLNC , a previously unknown long ncRNA, regulates neuronal activity by interacting with the neurodegeneration protein TDP-43.

Amyotrophic lateral sclerosis (ALS) is a debilitating motor neuron disease and lacks effective disease-modifying treatments. This study utilizes a comprehensive multiomic approach to investigate the early and sex-specific molecular mechanisms underlying ALS. By analyzing the prefrontal cortex of 51 patients with sporadic ALS and 50 control subjects, alongside four transgenic mouse models (C9orf72-, SOD1-, TDP-43-, and FUS-ALS), we have uncovered significant molecular alterations associated with the disease. Here, we show that males exhibit more pronounced changes in molecular pathways compared to females. Our integrated analysis of transcriptomes, (phospho)proteomes, and miRNAomes also identified distinct ALS subclusters in humans, characterized by variations in immune response, extracellular matrix composition, mitochondrial function, and RNA processing. The molecular signatures of human subclusters were reflected in specific mouse models. Our study highlighted the mitogen-activated protein kinase (MAPK) pathway as an early disease mechanism. We further demonstrate that trametinib, a MAPK inhibitor, has potential therapeutic benefits in vitro and in vivo, particularly in females, suggesting a direction for developing targeted ALS treatments.

Background: Parkinson's disease (PD) is the second most common neurodegenerative disorder whose prevalence is rapidly increasing worldwide. The molecular mechanisms underpinning the pathophysiology of sporadic PD remain incompletely understood. Therefore, causative therapies are still elusive. To obtain a more integrative view of disease‐mediated alterations, we investigated the molecular landscape of PD in human post‐mortem midbrains, a region that is highly affected during the disease process.Methods: Tissue from 19 PD patients and 12 controls were obtained from the Parkinson's UK Brain Bank and subjected to multi‐omic analyses: small and total RNA sequencing was performed on an Illumina's HiSeq4000, while proteomics experiments were performed in a hybrid triple quadrupole‐time of flight mass spectrometer (TripleTOF5600+) following quantitative sequential window acquisition of all theoretical mass spectra. Differential expression analyses were performed with customized frameworks based on DESeq2 (for RNA sequencing) and with Perseus v.1.5.6.0 (for proteomics). Custom pipelines in R were used for integrative studies.Results: Our analyses revealed multiple deregulated molecular targets linked to known disease mechanisms in PD as well as to novel processes. We have identified and experimentally validated (quantitative real‐time polymerase chain reaction/western blotting) several PD‐deregulated molecular candidates, including miR‐539‐3p, miR‐376a‐5p, miR‐218‐5p and miR‐369‐3p, the valid miRNA‐mRNA interacting pairs miR‐218‐5p/RAB6Cand miR‐369‐3p/GTF2H3, as well as multiple proteins, such as CHI3L1, HSPA1B, FNIP2 and TH. Vertical integration of multi‐omic analyses allowed validating disease‐mediated alterations across different molecular layers. Next to the identification of individual molecular targets in all explored omics layers, functional annotation of differentially expressed molecules showed an enrichment of pathways related to neuroinflammation, mitochondrial dysfunction and defects in synaptic function.Conclusions: This comprehensive assessment of PD‐affected and control human midbrains revealed multiple molecular targets and networks that are relevant to the disease mechanism of advanced PD. The integrative analyses of multiple omics layers underscore the importance of neuroinflammation, immune response activation, mitochondrial and synaptic dysfunction as putative therapeutic targets for advanced PD.

Axonal degeneration is a key and early pathological feature in traumatic and neurodegenerative disorders of the CNS. Following a focal lesion to axons, extended axonal disintegration by acute axonal degeneration (AAD) occurs within several hours. During AAD, the accumulation of autophagic proteins including Unc-51 like autophagy activating kinase 1 (ULK1) has been demonstrated, but its role is incompletely understood. Here, we study the effect of ULK1 inhibition in different models of lesion-induced axonal degeneration in vitro and in vivo. Overexpression of a dominant negative of ULK1 (ULK1.DN) in primary rat cortical neurons attenuates axotomy-induced AAD in vitro. Both ULK1.DN and the ULK1 inhibitor SBI-0206965 protect against AAD after rat optic nerve crush in vivo. ULK1.DN additionally attenuates long-term axonal degeneration after rat spinal cord injury in vivo. Mechanistically, ULK1.DN decreases autophagy and leads to an mTOR-mediated increase in translational proteins. Consistently, treatment with SBI-0206965 results in enhanced mTOR activation. ULK1.DN additionally modulates the differential splicing of the degeneration-associated genesKif1bandDdit3. These findings uncover ULK1 as an important mediator of axonal degeneration in vitro and in vivo, and elucidate its function in splicing, defining it as a putative therapeutic target.

Regional iron accumulation and α-synuclein (α-syn) spreading pathology within the central nervous system are common pathological findings in Parkinson’s disease (PD). Whereas iron is known to bind to α-syn, facilitating its aggregation and regulating α-syn expression, it is unclear if and how iron also modulates α-syn spreading. To elucidate the influence of iron on the propagation of α-syn pathology, we investigated α-syn spreading after stereotactic injection of α-syn preformed fibrils (PFFs) into the striatum of mouse brains after neonatal brain iron enrichment. C57Bl/6J mouse pups received oral gavage with 60, 120 or 240 mg/kg carbonyl-iron or vehicle between postnatal day 10 and 17. At 12 weeks of age, intrastriatal injections of 5 µg PFFs were performed to induce seeding of α-syn aggregates. At 90 days post-injection, PFFs injected mice displayed long-term memory deficits, without affection of motor behavior. Interestingly, quantification of α-syn phosphorylated at S129 showed reduced α-syn pathology and attenuated spreading to connectome-specific brain regions after brain iron enrichment. Furthermore, PFFs injection caused intrastriatal microglia accumulation, which was alleviated by iron in a dose-dependent way. In primary cortical neurons in a microfluidic chamber model in vitro, iron application did not alter transsynaptic α-syn propagation, possibly indicating an involvement of non-neuronal cells in this process. Our study suggests that α-syn PFFs may induce cognitive deficits in mice independent of iron. However, a redistribution of α-syn aggregate pathology and reduction of striatal microglia accumulation in the mouse brain may be mediated via iron-induced alterations of the brain connectome.

Abnormal metal distribution in vulnerable brain regions is involved in the pathogenesis of most neurodegenerative diseases, suggesting common molecular mechanisms of metal dyshomeostasis. This study aimed to compare the intra‐ and extra‐neuronal metal content and the expression of proteins related to metal homeostasis in the substantia nigra (SN) from patients with Parkinson's disease (PD), multiple sclerosis (MS), and control subjects. Metal quantification was performed via ion‐beam micro‐analysis in neuromelanin‐positive neurons and the surrounding tissue. For proteomic analysis, SN tissue lysates were analyzed on a nanoflow chromatography system hyphenated to a hybrid triple‐quadrupole time‐of‐flight mass spectrometer. We found increased amounts of iron in neuromelanin‐positive neurons and surrounding tissue in patients with PD and MS compared to controls (4‐ to 5‐fold higher) that, however, also showed large inter‐individual variations. Copper content was systematically lower (−2.4‐fold) in neuromelanin‐positive neurons of PD patients compared with controls, whereas it remained unchanged in MS. Protein–protein interaction (PPI) network analyses revealed clusters related to Fe and Cu homeostasis among PD‐deregulated proteins. An enrichment for the term “metal homeostasis” was observed for MS‐deregulated proteins. Important deregulated hub proteins included hemopexin and transferrin in PD, and calreticulin and ferredoxin reductase in MS. Our findings show that PD and MS share commonalities in terms of iron accumulation in the SN. Concomitant proteomics experiments revealed PPI networks related to metal homeostasis, substantiating the results of metal quantification.