SummaryReproducibility in molecular and cellular studies is fundamental to scientific discovery. To establish the reproducibility of a well-defined long-term neuronal differentiation protocol, we repeated the cellular and molecular comparison of the same two iPSC lines across five distinct laboratories. Despite uncovering acceptable variability within individual laboratories, we detect poor cross-site reproducibility of the differential gene expression signature between these two lines. Factor analysis identifies the laboratory as the largest source of variation along with several variation-inflating confounders such as passaging effects and progenitor storage. Single-cell transcriptomics shows substantial cellular heterogeneity underlying inter-laboratory variability and being responsible for biases in differential gene expression inference. Factor analysis-based normalization of the combined dataset can remove the nuisance technical effects, enabling the execution of robust hypothesis-generating studies. Our study shows that multi-center collaborations can expose systematic biases and identify critical factors to be standardized when publishing novel protocols, contributing to increased cross-site reproducibility.

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A broad spectrum of diseases is characterized by myelin abnormalities and/or oligodendrocyte pathology. In most, if not all, of these diseases, early activation of microglia occurs. Our knowledge regarding the factors triggering early microglia activation is, however, incomplete. In this study, we used the cuprizone model to investigate the temporal and causal relationship of oligodendrocyte apoptosis and early microglia activation. Genome-wide gene expression studies revealed the induction of distinct chemokines, among them Cxcl10, Ccl2, and Ccl3 in cuprizone-mediated oligodendrocyte apoptosis. Early microglia activation was unchanged in CCL2- and CCL3-deficient knockouts, but was significantly reduced in CXCL10-deficient mice, resulting in an amelioration of cuprizone toxicity at later time points. Subsequent in vitro experiments revealed that recombinant CXCL10 induced migration and a proinflammatory phenotype in cultured microglia, without affecting their phagocytic activity or proliferation. In situ hybridization analyses suggest that Cxcl10 mRNA is mainly expressed by astrocytes, but also oligodendrocytes, in short-term cuprizone-exposed mice. Our results show that CXCL10 actively participates in the initiation of microglial activation. These findings have implications for the role of CXCL10 as an important mediator during the initiation of neuroinflammatory processes associated with oligodendrocyte pathology.

A broad spectrum of diseases is characterized by myelin abnormalities, oligodendrocyte pathology, and concomitant glia activation, among multiple sclerosis (MS). Our knowledge regarding the factors triggering gliosis and demyelination is scanty. Chemokines are pivotal for microglia and astrocyte activation and orchestrate critical steps during the formation of central nervous system (CNS) demyelinating lesions. Redundant functions of chemokines complicate, however, the study of their functional relevance. We used the cuprizone model to study redundant functions of two chemokines, CCL2/MCP1 and CCL3/MIP1α, which are critically involved in the pathological process of cuprizone-induced demyelination. First, we generated a mutant mouse strain lacking functional genes of both chemokines and demonstrated that double-mutant animals are viable, fertile, and do not present with gross abnormalities. Astrocytes and peritoneal macrophages, cultured form tissues of these animals did neither express CCL2 nor CCL3. Exposure to cuprizone resulted in increased CCL2 and CCL3 brain levels in wild-type but not mutant animals. Cuprizone-induced demyelination, oligodendrocyte loss, and astrogliosis were significantly ameliorated in the cortex but not corpus callosum of chemokine-deficient animals. In summary, we provide a novel powerful model to study the redundant function of two important chemokines. Our study reveals that chemokine function in the CNS redounds to region-specific pathophysiological events.

Proton magnetic resonance spectroscopy (1H-MRS) is a quantitative MR imaging technique often used to complement conventional MR imaging with specific metabolic information. A key metabolite is the amino acid derivative N-Acetylaspartate (NAA) which is an accepted marker to measure the extent of neurodegeneration in multiple sclerosis (MS) patients. NAA is catabolized by the enzyme aspartoacylase (ASPA) which is predominantly expressed in oligodendrocytes. Since the formation of MS lesions is paralleled by oligodendrocyte loss, NAA might accumulate in the brain, and therefore, the extent of neurodegeneration might be underestimated. In the present study, we used the well-characterized cuprizone model. There, the loss of oligodendrocytes is paralleled by a reduction in ASPA expression and activity as demonstrated by genome-wide gene expression analysis and enzymatic activity assays. Notably, brain levels of NAA were not increased as determined by gas chromatography-mass spectrometry and 1H-MRS. These important findings underpin the reliability of NAA quantification as a valid marker for the paraclinical determination of the extent of neurodegeneration, even under conditions of oligodendrocyte loss in which impaired metabolization of NAA is expected. Future studies have to reveal whether other enzymes are able to metabolize NAA or whether an excess of NAA is cleared by other mechanisms rather than enzymatic metabolism.

The maternal serum copeptin, MR-proANP and PCT levels are higher in EO-PE and LO-PE patients, but the difference is not significant. Thus, their levels in first trimester are not proven to be effective markers to screen for PE.

Background Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder that, if inadequately treated, often progresses to joint destruction. Currently, patients are initially treated with conventional disease- modifying anti-rheumatic drugs (DMARDs); in patients with an inadequate response (IR), biologic DMARDs are often combined with methotrexate (MTX) or other DMARDs to improve efficacy. Objectives To compare the relative efficacy and safety of abatacept versus all relevant biologic DMARDs in MTX-IR patients with RA. Methods A systematic literature review identified randomised controlled trials (RCTs) investigating the efficacy and safety of abatacept subcutaneous (sc) and intravenous (iv), adalimumab, certolizumab, etanercept, infliximab, golimumab, tocilizumab and tofacitinib, in combination with MTX. The efficacy endpoints were American College of Rheumatology (ACR) 20/50/70 response rates and disease activity score 28 joints (DAS28) remission rates (DAS28≤2.6). Safety endpoints were incidence of serious adverse events (AE), infections, and serious infections. Abatacept sc and iv were compared to tocilizumab and the combined group of anti-TNFs (adalimumab, certolizumab, etanercept, infliximab, golimumab). Results were analysed with Bayesian hierarchical network meta-analysis (NMA) models to estimate the relative efficacy and safety effects of the biologic DMARDs. Although tofacitinib RCTS were identified in the systematic literature search, they were not included in the NMA because the study population of the three tofacitinib RCTs was different than that of the other RCTs; the majority of the patients in the tofacitinib RCTs were previously exposed to biologic DMARDs, while the patients in the other RCTs were naive to biologic DMARDs. Results The search was performed in October 2013. A total of 21 RCTs were included. Results indicate that abatacept sc has similar ACR20/50/70 response rates and DAS28 remission rates compared to other biologic DMARDs after 24 weeks of treatment (Table 1). Similar efficacy results were found for abatacept iv (data not shown). Abatacept sc seems to have slightly better safety in comparison to tocilizumab and the combined anti-TNFs in terms of incidence of infections, serious infections, and serious AE (Table 1); however, none of these differences were statistically significant. Similar results were found when comparing abatacept iv with tocilizumab and the combined anti-TNFs (data not shown). Table 1. Odds ratios (OR) and 95% credible intervals Abatacept sc versus ACR 20 ACR 50 ACR 70 DAS28<2.6 No infection* No serious infection* No serious AE* Tocilizumab 1.12 (0.91; 1.49) 1.03 (0.86; 1.26) 0.98 (0.70; 1.22) 0.82 (0.28; 1.10) 0.96 (0.68; 1.20) 1.51 (0.76; 4.26) 1.11 (0.73; 1.83) Combined anti-TNFs 0.96 (0.78; 1.13) 1.01 (0.87; 1.17) 0.98 (0.79; 1.16) 0.94 (0.73; 1.13) 1.06 (0.88; 1.32) 1.54 (0.85; 3.79) 1.25 (0.89; 1.95) *Modelled as the odds of not having an infection, serious infection or serious AE. Conclusions Both abatacept sc and iv showed ...

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