Protein O-Mannosylation in the Murine Brain: Occurrence of Mono-O-Mannosyl Glycans and Identification of New Substrates

Protein O-mannosylation is a post-translational modification essential for correct development of mammals. In humans, deficient O-mannosylation results in severe congenital muscular dystrophies often associated with impaired brain and eye development. Although various O-mannosylated proteins have been identified in the recent years, the distribution of O-mannosyl glycans in the mammalian brain and target proteins are still not well defined. In the present study, rabbit monoclonal antibodies directed against the O-mannosylated peptide YAT(α1-Man)AV were generated. Detailed characterization of clone RKU-1-3-5 revealed that this monoclonal antibody recognizes O-linked mannose also in different peptide and protein contexts. Using this tool, we observed that mono-O-mannosyl glycans occur ubiquitously throughout the murine brain but are especially enriched at inhibitory GABAergic neurons and at the perineural nets. Using a mass spectrometry-based approach, we further identified glycoproteins from the murine brain that bear single O-mannose residues. Among the candidates identified are members of the cadherin and plexin superfamilies and the perineural net protein neurocan. In addition, we identified neurexin 3, a cell adhesion protein involved in synaptic plasticity, and inter-alpha-trypsin inhibitor 5, a protease inhibitor important in stabilizing the extracellular matrix, as new O-mannosylated glycoproteins

Similar familial risk in multiple sclerosis subgroups Introduction

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Corroborating indicates nurses’ ethical values in a geriatric ward

The aim of the study was to identify nurses’ ethical values, which become apparent through their behaviour in the interactions with older patients in caring encounters at a geriatric clinic

A novel underuse model shows that inactivity but not ovariectomy determines the deteriorated material properties and geometry of cortical bone in the tibia of adult rats

Our goal in this study was to determine to what extent the physiologic consequences of ovariectomy (OVX) in bones are exacerbated by a lack of daily activity such as walking. We forced 14-week-old female rats to be inactive for 15 weeks with a unique experimental system that prevents standing and walking while allowing other movements. Tibiae, femora, and 4th lumbar vertebrae were analyzed by peripheral quantitative computed tomography (pQCT), microfocused X-ray computed tomography (micro-CT), histology, histomorphometry, Raman spectroscopy, and the three-point bending test. Contrary to our expectation, the exacerbation was very much limited to the cancellous bone parameters. Parameters of femur and tibia cortical bone were affected by the forced inactivity but not by OVX: (1) cross-sectional moment of inertia was significantly smaller in Sham-Inactive rat bones than that of their walking counterparts; (2) the number of sclerostin-positive osteocytes per unit cross-sectional area was larger in Sham-Inactive rat bones than in Sham-Walking rat bones; and (3) material properties such as ultimate stress of inactive rat tibia was lower than that of their walking counterparts. Of note, the additive effect of inactivity and OVX was seen only in a few parameters, such as the cancellous bone mineral density of the lumbar vertebrae and the structural parameters of cancellous bone in the lumbar vertebrae/tibiae. It is concluded that the lack of daily activity is detrimental to the strength and quality of cortical bone in the femur and tibia of rats, while lack of estrogen is not. Our inactive rat model, with the older rats, will aid the study of postmenopausal osteoporosis, the etiology of which may be both hormonal and mechanical

Multiomics analysis of rheumatoid arthritis yields sequence variants that have large effects on risk of the seropositive subset

Funding Information: Funding The study was funded by NORDFORSK (grant agreement no. 90825, project NORA), the Swedish Research Council (2018-02803), the Swedish innovation Agency (Vinnova), Innovationsfonden and The Research Council of Norway, Region Stockholm-Karolinska Institutet and Region Västerbotten (ALF), the Danish Rheumatism Association (R194-A6956), the Swedish Brain Foundation, Nils and Bibbi Jensens Foundation, the Knut and Alice Wallenberg Foundation, Margaretha af Ugglas Foundation, the South-Eastern Heath Region of Norway, the Health Research Fund of Central Denmark Region, Region of Southern Denmark, the A.P. Moller Foundation for the Advancement of Medical Science, the Colitis-Crohn Foreningen, the Novo Nordisk Foundation (NNF15OC0016932), Aase og Ejnar Danielsens Fond, Beckett-Fonden, Augustinus Fonden, Knud and Edith Eriksens Mindefond, Laege Sofus Carl Emil Friis and Hustru Olga Doris Friis’ Legat, the Psoriasis Forskningsfonden, the University of Aarhus, the Danish Rheumatism Association (R194-A6956, A1923, A3037 and A3570 – www. gigtforeningen.dk), Region of Southern Denmark’s PhD Fund, 12/7725 (www.regionsyddanmark.dk) and the Department of Rheumatology, Frederiksberg Hospital (www.frederiksberghospital. dk). MoBa Genetics has been funded by the Research Council of Norway (#229624, #223273), South East and Western Norway Health Authorities, ERC AdG project SELECTionPREDISPOSED, Stiftelsen Kristian Gerhard Jebsen, Trond Mohn Foundation, the Novo Nordisk Foundation and the University of Bergen. KB and SB acknowledge the Novo Nordisk Foundation (grant NNF14CC0001). Funding Information: competing financial interests as employees. OAA is a consultant to HealthLytix. The following coauthors report the following but unrelated to the current report: Karolinska Institutet, with JA as principal investigator, has entered into agreements with the following entities, mainly but not exclusively for safety monitoring of rheumatology immunomodulators: Abbvie, BMS, Eli Lilly, Janssen, MSD, Pfizer, Roche, Samsung Bioepis and Sanofi, unrelated to the present study. SB has ownerships in Intomics A/S, Hoba Therapeutics Aps, Novo Nordisk A/S, Lundbeck A/S and managing board memberships in Proscion A/S and Intomics A/S. BG has received research grants from AbbVie, Bristol Myers-Squibb and Pfizer; OH has received research grants from AbbVie, Novartis and Pfizer, DVJ has received speaker and consultation fees from AbbVie, Janssen, Lilly, MSD, Novartis, Pfizer, Roche and UCB, AGL has received speaking and/or consulting fees from AbbVie, Janssen, Lilly, MSD, Novartis, Pfizer, Roche and UCB; and CT has received consulting fees from Roche, speaker fees from Abbvie, Bristol Myers-Squibb, Nordic Drugs, Pfizer and Roche, and an unrestricted grant from Bristol Myers-Squibb. Publisher Copyright: © Funding Information: Funding The study was funded by NORDFORSK (grant agreement no. 90825, project NORA), the Swedish Research Council (2018-02803), the Swedish innovation Agency (Vinnova), Innovationsfonden and The Research Council of Norway, Region Stockholm-Karolinska Institutet and Region Västerbotten (ALF), the Danish Rheumatism Association (R194-A6956), the Swedish Brain Foundation, Nils and Bibbi Jensens Foundation, the Knut and Alice Wallenberg Foundation, Margaretha af Ugglas Foundation, the South-Eastern Heath Region of Norway, the Health Research Fund of Central Denmark Region, Region of Southern Denmark, the A.P. Moller Foundation for the Advancement of Medical Science, the Colitis-Crohn Foreningen, the Novo Nordisk Foundation (NNF15OC0016932), Aase og Ejnar Danielsens Fond, Beckett-Fonden, Augustinus Fonden, Knud and Edith Eriksens Mindefond, Laege Sofus Carl Emil Friis and Hustru Olga Doris Friis’ Legat, the Psoriasis Forskningsfonden, the University of Aarhus, the Danish Rheumatism Association (R194-A6956, A1923, A3037 and A3570 – www. gigtforeningen.dk), Region of Southern Denmark’s PhD Fund, 12/7725 (www.regionsyddanmark.dk) and the Department of Rheumatology, Frederiksberg Hospital (www.frederiksberghospital. dk). MoBa Genetics has been funded by the Research Council of Norway (#229624, #223273), South East and Western Norway Health Authorities, ERC AdG project SELECTionPREDISPOSED, Stiftelsen Kristian Gerhard Jebsen, Trond Mohn Foundation, the Novo Nordisk Foundation and the University of Bergen. KB and SB acknowledge the Novo Nordisk Foundation (grant NNF14CC0001). Funding Information: competing financial interests as employees. OAA is a consultant to HealthLytix. The following coauthors report the following but unrelated to the current report: Karolinska Institutet, with JA as principal investigator, has entered into agreements with the following entities, mainly but not exclusively for safety monitoring of rheumatology immunomodulators: Abbvie, BMS, Eli Lilly, Janssen, MSD, Pfizer, Roche, Samsung Bioepis and Sanofi, unrelated to the present study. SB has ownerships in Intomics A/S, Hoba Therapeutics Aps, Novo Nordisk A/S, Lundbeck A/S and managing board memberships in Proscion A/S and Intomics A/S. BG has received research grants from AbbVie, Bristol Myers-Squibb and Pfizer; OH has received research grants from AbbVie, Novartis and Pfizer, DVJ has received speaker and consultation fees from AbbVie, Janssen, Lilly, MSD, Novartis, Pfizer, Roche and UCB, AGL has received speaking and/or consulting fees from AbbVie, Janssen, Lilly, MSD, Novartis, Pfizer, Roche and UCB; and CT has received consulting fees from Roche, speaker fees from Abbvie, Bristol Myers-Squibb, Nordic Drugs, Pfizer and Roche, and an unrestricted grant from Bristol Myers-Squibb. Publisher Copyright: ©Objectives To find causal genes for rheumatoid arthritis (RA) and its seropositive (RF and/or ACPA positive) and seronegative subsets. Methods We performed a genome-wide association study (GWAS) of 31 313 RA cases (68% seropositive) and ∼1 million controls from Northwestern Europe. We searched for causal genes outside the HLA-locus through effect on coding, mRNA expression in several tissues and/or levels of plasma proteins (SomaScan) and did network analysis (Qiagen). Results We found 25 sequence variants for RA overall, 33 for seropositive and 2 for seronegative RA, altogether 37 sequence variants at 34 non-HLA loci, of which 15 are novel. Genomic, transcriptomic and proteomic analysis of these yielded 25 causal genes in seropositive RA and additional two overall. Most encode proteins in the network of interferon-Alpha/beta and IL-12/23 that signal through the JAK/STAT-pathway. Highlighting those with largest effect on seropositive RA, a rare missense variant in STAT4 (rs140675301-A) that is independent of reported non-coding STAT4-variants, increases the risk of seropositive RA 2.27-fold (p=2.1×10-9), more than the rs2476601-A missense variant in PTPN22 (OR=1.59, p=1.3×10-160). STAT4 rs140675301-A replaces hydrophilic glutamic acid with hydrophobic valine (Glu128Val) in a conserved, surface-exposed loop. A stop-mutation (rs76428106-C) in FLT3 increases seropositive RA risk (OR=1.35, p=6.6×10-11). Independent missense variants in TYK2 (rs34536443-C, rs12720356-C, rs35018800-A, latter two novel) associate with decreased risk of seropositive RA (ORs=0.63-0.87, p=10-9-10-27) and decreased plasma levels of interferon-Alpha/beta receptor 1 that signals through TYK2/JAK1/STAT4. Conclusion Sequence variants pointing to causal genes in the JAK/STAT pathway have largest effect on seropositive RA, while associations with seronegative RA remain scarce.Peer reviewe