👤 Isabelle Meunier

Lecanemab binds "protofibrils," which are poorly characterized in human brain. It is unknown why lecanemab caused fewer amyloid-related imaging abnormalities (ARIAs) than other antibodies in trials. The apolipoprotein E (APOE) ε4 allele increases ARIA risk through unknown mechanisms. Equilibrium binding constants (K Lecanemab and aducanumab had indistinguishable preference for "protofibrils." Antibody preference for plaque-enriched versus CAA-enriched Aβ did not differ in soluble extracts or by IF staining but differed slightly in insoluble extracts. The APOE ε4 allele was associated with more soluble antibody-accessible Aβ. Lecanemab's binding target is similar to other antibodies'. Differences in antibody preference for plaque versus CAA Aβ may not explain differences in ARIA with edema rates. Show less

Vascular endothelial growth factor receptors (VEGFRs) have emerged as the most promising anti-angiogenic therapeutic targets for the treatment of recurrent glioblastomas (GBM). However, anti-VEGF treatments led to the high proportion of non-responder patients or non lasting clinical response and the tumor progression to the greater malignant stage. To overcome these problems, there is an utmost need to develop innovative anti-angiogenic therapies. In this study, we report the development of a series of new FGFR1 inhibitors. Among them, compound 4i was able to potently inhibit FGFR1 kinase activities both in vitro and in vivo. This compound displayed strong anti-angiogenic activity in HUVECs and anti-tumor growth and anti-invasion effects in U-87MG cell line. These results emphasize the importance of FGFR1-mediated signaling pathways in GBM and reveal that pharmacological inhibition of FGFR1 can enhance the anti-tumoral, anti-angiogenic and anti-metastatic efficiency against GBM. These data support targeting of FGFR1 as a novel anti-angiogenic strategy and highlight the potential of compound 4i as a promising anti-angiogenic and anti-metastatic candidate for GBM therapy. Show less

Biallelic variants in CLN3 lead to a spectrum of diseases, ranging from severe neurodegeneration with retinal involvement (juvenile neuronal ceroid lipofuscinosis) to retina-restricted conditions. To provide a detailed description of the retinal phenotype of patients with isolated retinal degeneration harboring biallelic CLN3 pathogenic variants and to attempt a phenotype-genotype correlation associated with this gene defect. This retrospective cohort study included patients carrying biallelic CLN3 variants extracted from a cohort of patients with inherited retinal disorders (IRDs) investigated at the National Reference Center for Rare Ocular Diseases of the Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts from December 2007 to August 2020. Data were analyzed from October 2019 to August 2020. Functional (best-corrected visual acuity, visual field, color vision, and full-field electroretinogram), morphological (multimodal retinal imaging), and clinical data from patients were collected and analyzed. Gene defect was identified by either next-generation sequencing or whole-exome sequencing and confirmed by Sanger sequencing, quantitative polymerase chain reaction, and cosegregation analysis. Of 1533 included patients, 843 (55.0%) were women and 690 (45.0%) were men. A total of 15 cases from 11 unrelated families harboring biallelic CLN3 variants were identified. All patients presented with nonsyndromic IRD. Two distinct patterns of retinal disease could be identified: a mild rod-cone degeneration of middle-age onset (n = 6; legal blindness threshold reached by 70s) and a severe retinal degeneration with early macular atrophic changes (n = 9; legal blindness threshold reached by 40s). Eleven distinct pathogenic variants were detected, of which 4 were novel. All but 1, p.(Arg405Trp), CLN3 point variants and their genotypic associations were clearly distinct between juvenile neuronal ceroid lipofuscinosis and retina-restricted disease. Mild and severe forms of retina-restricted CLN3-linked IRDs also had different genetic background. These findings suggest CLN3 should be included in next-generation sequencing panels when investigating patients with nonsyndromic rod-cone dystrophy. These results document phenotype-genotype correlations associated with specific variants in CLN3. However, caution seems warranted regarding the potential neurological outcome if a pathogenic variant in CLN3 is detected in a case of presumed isolated IRD for the onset of neurological symptoms could be delayed. Show less

Mice lacking the bHLH transcription factor (TF) Neurog3 do not form pancreatic islet cells, including insulin-secreting beta cells, the absence of which leads to diabetes. In humans, homozygous mutations of NEUROG3 manifest with neonatal or childhood diabetes. Despite this critical role in islet cell development, the precise function of and downstream genetic programs regulated directly by NEUROG3 remain elusive. Therefore, we mapped genome-wide NEUROG3 occupancy in human induced pluripotent stem cell (hiPSC)-derived endocrine progenitors and determined NEUROG3 dependency of associated genes to uncover direct targets. We generated a novel hiPSC line (NEUROG3-HA-P2A-Venus) where NEUROG3 is HA-tagged and fused to a self-cleaving fluorescent VENUS reporter. We used the CUT&RUN technique to map NEUROG3 occupancy and epigenetic marks in pancreatic endocrine progenitors (PEP) that were differentiated from this hiPSC line. We integrated NEUROG3 occupancy data with chromatin status and gene expression in PEPs as well as their NEUROG3-dependence. In addition, we investigated whether NEUROG3 binds type 2 diabetes mellitus (T2DM)-associated variants at the PEP stage. CUT&RUN revealed a total of 863 NEUROG3 binding sites assigned to 1263 unique genes. NEUROG3 occupancy was found at promoters as well as at distant cis-regulatory elements that frequently overlapped within PEP active enhancers. De novo motif analyses defined a NEUROG3 consensus binding motif and suggested potential co-regulation of NEUROG3 target genes by FOXA or RFX transcription factors. We found that 22% of the genes downregulated in NEUROG3 Mapping NEUROG3 genome occupancy in PEPs uncovered unexpectedly broad, direct control of the endocrine genes, raising novel hypotheses on how this master regulator controls islet and beta cell differentiation. Show less

The evolutionary conserved NSL complex is a prominent epigenetic regulator controlling expression of thousands of genes. Here we uncover a novel function of the NSL complex members in mitosis. As the cell enters mitosis, KANSL1 and KANSL3 undergo a marked relocalisation from the chromatin to the mitotic spindle. By stabilizing microtubule minus ends in a RanGTP-dependent manner, they are essential for spindle assembly and chromosome segregation. Moreover, we identify KANSL3 as a microtubule minus-end-binding protein, revealing a new class of mitosis-specific microtubule minus-end regulators. By adopting distinct functions in interphase and mitosis, KANSL proteins provide a link to coordinate the tasks of faithful expression and inheritance of the genome during different phases of the cell cycle. Show less