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Mitochondria membrane protein-associated neurodegeneration (MPAN) neurodegenerative disorder is typically associated with biallelic C19orf12 variants. Here we describe a new and review candidate previous monoallelic de novo C19orf12 variants to define loss of function mutations located in the putative non-membrane spanning C19orf12 isoform as the potential basis of monoallelic MPAN.

While molecular studies commonly show lipid abnormalities in monogenic motor neurone diseases, there is no clarity regarding the key functional pathways involved. Rickman et al. review the evidence to propose ‘subcellular lipidome imbalance’ in specific lipid pathways as a common pathological mechanism in these disorders., Motor neuron diseases (MNDs) encompass an extensive and heterogeneous group of upper and/or lower motor neuron degenerative disorders, in which the particular clinical outcomes stem from the specific neuronal component involved in each condition. While mutations in a large number of molecules associated with lipid metabolism are known to be implicated in MNDs, there remains a lack of clarity regarding the key functional pathways involved, and their inter-relationships. This review highlights evidence that defines defects within two specific lipid (cholesterol/oxysterol and phosphatidylethanolamine) biosynthetic cascades as being centrally involved in MND, particularly hereditary spastic paraplegia. We also identify how other MND-associated molecules may impact these cascades, in particular through impaired organellar interfacing, to propose ‘subcellular lipidome imbalance’ as a likely common pathomolecular theme in MND. Further exploration of this mechanism has the potential to identify new therapeutic targets and management strategies for modulation of disease progression in hereditary spastic paraplegias and other MNDs.

The raw datasets of oxysterol quantifications from whole cell and mitochondrial fractions of THP-1 monocytes and macrophages, neuronal-like SH-SH5Y cells and human peripheral blood mononuclear cells are presented. Oxysterols were quantified using a new liquid chromatography-mass spectrometry (LC-MS) and multiple reaction monitoring analysis published in the article "A quantitative LC-MS/MS method for analysis of mitochondrial-specific oxysterol metabolism" in Redox Biology [1]. This method showed improved extraction efficiency and recovery of mono and dihydroxycholesterols from cellular matrix. The datasets derived from the three cell lines are included in the appendix. These datasets provide new information about the oxysterol distribution in THP-1 monocytes and macrophages, SH-SY5Y cells and peripheral blood mononuclear cells. These datasets can be used as a guide for oxysterol distribution in the three cell lines for future studies, and can used for future method optimization, and for comparison of oxysterol recovery with other analytical techniques.

Oxysterols are critical regulators of inflammation and cholesterol metabolism in cells. They are oxidation products of cholesterol and may be differentially metabolised in subcellular compartments and in biological fluids. New analytical methods are needed to improve our understanding of oxysterol trafficking and the molecular interplay between the cellular compartments required to maintain cholesterol/oxysterol homeostasis. Here we describe a method for isolation of oxysterols using solid phase extraction and quantification by liquid chromatography-mass spectrometry, applied to tissue, cells and mitochondria. We analysed five monohydroxysterols; 24(S)-hydroxycholesterol, 25-hydroxycholesterol, 27-hydroxycholesterol, 7α-hydroxycholesterol, 7 ketocholesterol and three dihydroxysterols 7α-24(S)dihydroxycholesterol, 7α-25dihydroxycholesterol, 7α-27dihydroxycholesterol by LC-MS/MS following reverse phase chromatography. Our new method, using Triton and DMSO extraction, shows improved extraction efficiency and recovery of oxysterols from cellular matrix. We validated our method by reproducibly measuring oxysterols in mouse brain tissue and showed that mice fed a high fat diet had significantly lower levels of 24S/25diOHC, 27diOHC and 7ketoOHC. We measured oxysterols in mitochondria from peripheral blood mononuclear cells and highlight the importance of rapid cell isolation to minimise effects of handling and storage conditions on oxysterol composition in clinical samples. In addition, in vitro cell culture systems, of THP-1 monocytes and neuronal-like SH-SH5Y cells, showed mitochondrial-specific oxysterol metabolism and profiles were lineage specific. In summary, we describe a robust and reproducible method validated for improved recovery, quantitative linearity and detection, reproducibility and selectivity for cellular oxysterol analysis. This method enables subcellular oxysterol metabolism to be monitored and is versatile in its application to various biological and clinical samples., Highlights • New method for extraction and quantification of mono and dihydroxysterols from mitochondria. • Method offers high sensitivity and selectivity allowing quantification of oxysterols at ≥5pg.μl−1. • Successful application to tissue, primary cells and cell lines. • Common oxysterol metabolites are present in blood and brain cell mitochondria.

Nine xylanolytic bacterial strains were isolated from fen and heath soils in northern Iceland. They were found by 16S rRNA gene sequencing to belong to the genera Paenibacillus, Bacillus, Pseudomonas, and Stenotrophomonas. Using a simple, plate-based semiquantitative assay with azo-crosslinked xylan as the substrate, it was determined that although isolated from cold environments, most of the strains displayed greater xylanolytic activity under mesophilic conditions, with only the paenibacilli displaying markedly cold-active xylanolytic activity. Indeed, for one isolate, Paenibacillus castaneae OV2122, xylanolytic activity was only detected at 15°C and below under the conditions tested. Of the nine strains, Paenibacillus amylolyticus OV2121 displayed the greatest activity at 5°C. Glycohydrolase family-specific PCR indicated that the paenibacilli produced multiple xylanases of families 10 and 11, whereas a family 8 xylanase was detected in Pseudomonas kilonensis AL1515, and a family 11 xylanase in Stenotrophomonas rhizophila AL1610., This work was in part conducted under an ERASMUS internship exchange programme and was funded by the University of Akureyri Research Fund.

Nine xylanolytic bacterial strains were isolated from fen and heath soils in northern Iceland. They were found by 16S rRNA gene sequencing to belong to the generaPaenibacillus,Bacillus,Pseudomonas, andStenotrophomonas. Using a simple, plate-based semiquantitative assay with azo-crosslinked xylan as the substrate, it was determined that although isolated from cold environments, most of the strains displayed greater xylanolytic activity under mesophilic conditions, with only the paenibacilli displaying markedly cold-active xylanolytic activity. Indeed, for one isolate,Paenibacillus castaneaeOV2122, xylanolytic activity was only detected at 15°C and below under the conditions tested. Of the nine strains,Paenibacillus amylolyticusOV2121 displayed the greatest activity at 5°C. Glycohydrolase family-specific PCR indicated that the paenibacilli produced multiple xylanases of families 10 and 11, whereas a family 8 xylanase was detected inPseudomonas kilonensisAL1515, and a family 11 xylanase inStenotrophomonas rhizophilaAL1610.