Enhancing mitochondrial activity in neurons protects against neurodegeneration in a mouse model of multiple sclerosis
Abstract
While transcripts of neuronal mitochondrial genes are strongly suppressed in central nervous system inflammation, it is unknown whether this results in mitochondrial dysfunction and whether an increase of mitochondrial function can rescue neurodegeneration. Here we show that predominantly genes of the electron transport chain are suppressed in inflamed mouse neurons resulting in impaired mitochondrial complex IV activity. This was associated with posttranslational inactivation of the transcriptional co-regulator PGC-1α. In mice, neuronal overexpression of Ppargc1a, which encodes for PGC-1α, led to increased numbers of mitochondria, complex IV activity and maximum respiratory capacity. Moreover, Ppargc1a overexpressing neurons showed a higher mitochondrial membrane potential that related to an improved calcium buffering capacity. Accordingly, neuronal deletion of Ppargc1a aggravated neurodegeneration during experimental autoimmune encephalomyelitis (EAE), while neuronal overexpression of Ppargc1a ameliorated it. Our study provides systemic insights into mitochondrial dysfunction in neurons during inflammation and commends elevation of mitochondrial activity as a promising neuroprotective strategy.
Data availability
All current data have been provided. Supplemental figures are included in the article file. All individual data are reported within the figure graphs as scatter plots. Numerical data for Figure 3E, 5A and 5C can be found as Source Data.Enrichment analysis was performed using the function 'gseGO' of the R package clusterProfiler; plotting was performed with the R packages ggplot2, clusterProfiler and tidyheatmap.Normalization, calcium spikes, base line detection, and analysis of the calcium clearance rate were performed with the custom-made script written on Python 3.6 (https://github.com/scriptcalcium/PGC1alpha).
-
Bassoon proteinopathy drives neurodegeneration in multiple sclerosisGene Expression Omnibus: Accession number GSE104899.
Article and author information
Author details
Funding
Stifterverband (Clinician-Scientist Fellowship)
- Sina C Rosenkranz
Gemeinnützige Hertie-Stiftung (Hertie Network of Excellence in Clinical Neuroscience)
- Sina C Rosenkranz
Deutsche Forschungsgemeinschaft (FR1720/9-1,FR1720/9-2)
- Manuel A Friese
Deutsche Forschungsgemeinschaft (FR1638/3-1,FR1638/3-2)
- Marc Freichel
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All animal care and experimental procedures were performed according to institutional guidelines and conformed to requirements of the German Animal Welfare Act. All animal experiments were approved by the local ethics committee (Behörde für Soziales, Familie, Gesundheit und Verbraucherschutz in Hamburg; G22/13 and 122/17). We conducted all procedures in accordance with the ARRIVE guidelines (Kilkenny et al., 2010).
Copyright
© 2021, Rosenkranz et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 4,721
- views
-
- 597
- downloads
-
- 51
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Immunology and Inflammation
The incidence of metabolic dysfunction-associated steatotic liver disease (MASLD) has been increasing worldwide. Since gut-derived bacterial lipopolysaccharides (LPS) can travel via the portal vein to the liver and play an important role in producing hepatic pathology, it seemed possible that (1) LPS stimulates hepatic cells to accumulate lipid, and (2) inactivating LPS can be preventive. Acyloxyacyl hydrolase (AOAH), the eukaryotic lipase that inactivates LPS and oxidized phospholipids, is produced in the intestine, liver, and other organs. We fed mice either normal chow or a high-fat diet for 28 weeks and found that Aoah-/- mice accumulated more hepatic lipid than did Aoah+/+ mice. In young mice, before increased hepatic fat accumulation was observed, Aoah-/- mouse livers increased their abundance of sterol regulatory element-binding protein 1, and the expression of its target genes that promote fatty acid synthesis. Aoah-/- mice also increased hepatic expression of Cd36 and Fabp3, which mediate fatty acid uptake, and decreased expression of fatty acid-oxidation-related genes Acot2 and Ppara. Our results provide evidence that increasing AOAH abundance in the gut, bloodstream, and/or liver may be an effective strategy for preventing or treating MASLD.
-
- Immunology and Inflammation
- Microbiology and Infectious Disease
Pseudomonas aeruginosa (PA) is an opportunistic, frequently multidrug-resistant pathogen that can cause severe infections in hospitalized patients. Antibodies against the PA virulence factor, PcrV, protect from death and disease in a variety of animal models. However, clinical trials of PcrV-binding antibody-based products have thus far failed to demonstrate benefit. Prior candidates were derivations of antibodies identified using protein-immunized animal systems and required extensive engineering to optimize binding and/or reduce immunogenicity. Of note, PA infections are common in people with cystic fibrosis (pwCF), who are generally believed to mount normal adaptive immune responses. Here, we utilized a tetramer reagent to detect and isolate PcrV-specific B cells in pwCF and, via single-cell sorting and paired-chain sequencing, identified the B cell receptor (BCR) variable region sequences that confer PcrV-specificity. We derived multiple high affinity anti-PcrV monoclonal antibodies (mAbs) from PcrV-specific B cells across three donors, including mAbs that exhibit potent anti-PA activity in a murine pneumonia model. This robust strategy for mAb discovery expands what is known about PA-specific B cells in pwCF and yields novel mAbs with potential for future clinical use.