Innate lymphoid cell characterization in the rat and their correlation to gut commensal microbes.

Innate lymphoid cells (ILCs) are important for tissue immune homeostasis, and are thoroughly characterized in mice and humans. Here, we have performed in-depth characterization of rat ILCs. Rat ILCs were identified based on differential expression of transcription factors and lack of lineage markers. ILC3s represented the major ILC population of the small intestine, while ILC2s were infrequent but most prominent in liver and adipose tissue. Two major subsets of group 1 ILCs were defined. Lineage- T-bet+ Eomes+ cells were identified as conventional NK cells, while lineage- T-bet+ Eomes- cells were identified as the probable rat counterpart of ILC1s based on their selective expression of the ILC marker CD200R. Rat ILC1s were particularly abundant in liver and intestinal tissues, and were functionally similar to NK cells. Single-cell transcriptomics of spleen and liver cells confirmed the main division of NK cells and ILC1-like cells, and demonstrated Granzyme A as an additional ILC1 marker. We further report differential distributions of NK cells and ILCs along the small and large intestines, and the association of certain bacterial taxa to frequencies of ILCs. In conclusion, we provide a framework for future studies of ILCs in diverse rat experimental models, and novel data on the potential interplay between commensals and intestinal ILCs

Absence of cardiovascular manifestations in a haploinsufficient Tgfbr1 mouse model

Loeys-Dietz syndrome (LDS) is an autosomal dominant arterial aneurysm disease belonging to the spectrum of transforming growth factor β (TGFβ)-associated vasculopathies. In its most typical form it is characterized by the presence of hypertelorism, bifid uvula/cleft palate and aortic aneurysm and/or arterial tortuosity. LDS is caused by heterozygous loss of function mutations in the genes encoding TGFβ receptor 1 and 2 (TGFBR1 and -2), which lead to a paradoxical increase in TGFβ signaling. To address this apparent paradox and to gain more insight into the pathophysiology of aneurysmal disease, we characterized a new Tgfbr1 mouse model carrying a p.Y378*nonsense mutation. Study of the natural history in this model showed that homozygous mutant mice die during embryonic development due to defective vascularization. Heterozygous mutant mice aged 6 and 12 months were morphologically and (immuno)histochemically indistinguishable from wild-type mice. We show that the mutant allele is degraded by nonsense mediated mRNA decay, expected to result in haploinsufficiency of the mutant allele. Since this haploinsufficiency model does not result in cardiovascular malformations, it does not allow further study of the process of aneurysm formation. In addition to providing a comprehensive method for cardiovascular phenotyping in mice, the results of this study confirm that haploinsuffciency is not the underlying genetic mechanism in human LDS

Neil3-dependent base excision repair regulates lipid metabolism and prevents atherosclerosis in Apoe-deficient mice

Increasing evidence suggests that oxidative DNA damage accumulates in atherosclerosis. Recently, we showed that a genetic variant in the human DNA repair enzyme NEIL3 was associated with increased risk of myocardial infarction. Here, we explored the role of Neil3/NEIL3 in atherogenesis by both clinical and experimental approaches. Human carotid plaques revealed increased NEIL3 mRNA expression which significantly correlated with mRNA levels of the macrophage marker CD68. Apoe−/−Neil3−/− mice on high-fat diet showed accelerated plaque formation as compared to Apoe−/− mice, reflecting an atherogenic lipid profile, increased hepatic triglyceride levels and attenuated macrophage cholesterol efflux capacity. Apoe−/−Neil3−/− mice showed marked alterations in several pathways affecting hepatic lipid metabolism, but no genotypic alterations in genome integrity or genome-wide accumulation of oxidative DNA damage. These results suggest a novel role for the DNA glycosylase Neil3 in atherogenesis in balancing lipid metabolism and macrophage function, potentially independently of genome-wide canonical base excision repair of oxidative DNA damage

DNA glycosylase Neil3 regulates vascular smooth muscle cell biology during atherosclerosis development.

BACKGROUND AND AIMS: Atherogenesis involves a complex interaction between immune cells and lipids, processes greatly influenced by the vascular smooth muscle cell (VSMC) phenotype. The DNA glycosylase NEIL3 has previously been shown to have a role in atherogenesis, though whether this is due to its ability to repair DNA damage or to other non-canonical functions is not yet clear. Hereby, we investigate the role of NEIL3 in atherogenesis, specifically in VSMC phenotypic modulation, which is critical in plaque formation and stability. METHODS: Chow diet-fed atherosclerosis-prone Apoe-/- mice deficient in Neil3, and NEIL3-abrogated human primary aortic VSMCs were characterized by qPCR, and immunohistochemical and enzymatic-based assays; moreover, single-cell RNA sequencing, mRNA sequencing, and proteomics were used to map the molecular effects of Neil3/NEIL3 deficiency in the aortic VSMC phenotype. Furthermore, BrdU-based proliferation assays and Western blot were performed to elucidate the involvement of the Akt signaling pathway in the transdifferentiation of aortic VSMCs lacking Neil3/NEIL3. RESULTS: We show that Neil3 deficiency increases atherosclerotic plaque development without affecting systemic lipids. This observation was associated with a shift in VSMC phenotype towards a proliferating, lipid-accumulating and secretory macrophage-like cell phenotype, without changes in DNA damage. VSMC transdifferentiation in Neil3-deficient mice encompassed increased activity of the Akt signaling pathway, supported by cell experiments showing Akt-dependent proliferation in NEIL3-abrogated human primary aortic VSMCs. CONCLUSIONS: Our findings show that Neil3 deficiency promotes atherosclerosis development through non-canonical mechanisms affecting VSMC phenotype involving activation of the Akt signaling pathway

Assessment practices and students' knowledge profiles in a problem-based curriculum

Since the mid-1980s, many new terms have enriched the assessment literature, such as performance assessment, authentic assessment, direct assessment and curriculum-embedded assessment. This boom is a result of changes in instructional as well as in assessment approaches. Criteria for good instruction as well as good assessment practices are suggested, derived from research-based models in the field of cognitive psychology and expert-novice studies. This article first reports on the translation of these criteria into a set of the characteristics of the assessment system of a problem-based curriculum in the field of Economics and Business Administration. Secondly, the article reports a study on improving assessment practices. Is it important to map students' knowledge profiles when attempting to remediate problem-solving performances? The answer to this question depends on the extent to which a student's problem-solving performance is influenced by the quality of his/her knowledge profile. Students' knowledge profile is measured by a Knowledge Test and a Sorting Task. Students' problem-solving skills are assessed by an Overall Test. The results indicate that students with an organised knowledge base perform better in problem-solving situations than students whose conceptual models are loosely structured. The implications of these findings for instruction as well as for assessment are discussed.status: publishe

The contribution of assessment experiences to student teachers' self-efficacy in competence-based education

Earlier research argues that educational programmes based on social cognitive theory are successful in improving students' self-efficacy. Focussing on some formative assessment characteristics, this qualitative research intends to study in-depth how student teachers' assessment experiences contribute to their self-efficacy. We interviewed 15 s year student teachers enrolled in a competence based teacher educational programme. Thematic content analysis results reveal that the assessment characteristics 'authenticity' and 'feedback' exert a positive influence on student teachers self-efficacy during all phases of the portfolio competence assessment. The results provide a fine-grained view of several types of self-efficacy information connected with these assessment phases

The assessment of quantitative problemsolving skills with "none of the above" items (NOTA items)

In this contribution we concentrate on the features of a particular item format: items having as the last option "none of the above" (NOTA items). There is consider-able dispute on the advisability of the usage of NOTA items in testing. Some authors come to the conclusion that NOTA items should be avoided, some come to neutral conclusions while others argue that NOTA items are optimal test items. In this article, we provide evidence to this discussion by conducting protocol analysis on written statements of examinees while answering NOTA items. In our investigation, a test containing 30 multiple-choice items was administered from 169 university students. The results show that NOTA options appear to be more attractive than options with specified solutions in those cases where a problemsolver fails. Also, a relationship is found between the quality of (incorrect) problemsolving and the choice of NOTA items: the more qualitative the incorrect problemsolving process is, the more likely the student is to choose for NOTA items. Overall, our research supports the statement that 'the more confidence an examinee has in his worked solution, which is inconsistent with one of the specified solutions, the more eager he seems to choose "none of the above".Afdeling Didactiek. Centrum voor Opleidingsdidactiek. Centrum voor Instructiepsychologie en -technologie. Leuvens Instituut voor onderwijsonderzoek (LIVO)status: publishe

Assessment as learning: De volgende stap in de toetsrevolutie

De toetsrevolutie is al enige jaren aan de gang. Sinds de boeken Alternatives in Assessment of Achievements, Learning Processes and Prior Knowledge (Birenbaum & Dochy, 1996) en Optimising New Modes of Assessment: In Search of Qualities and Standards (Segers, Dochy & Cascallar, 2003) is in het onderwijs en in opleidingen een balletje aan het rollen gebracht. Langzaamaan kwamen onderzoekers en practici tot de conclusie dat nieuwe vormen van assessment nuttig zijn om te beoordelen, om een diversiteit van toetsen te stimuleren en om een assessment te richten op wat wenselijk is