Kif11 dependent cell cycle progression in radial glial cells is required for proper neurogenesis in the zebrafish neural tube.

Radial glia serve as the resident neural stem cells in the embryonic vertebrate nervous system, and their proliferation must be tightly regulated to generate the correct number of neuronal and glial cell progeny in the neural tube. During a forward genetic screen, we recently identified a zebrafish mutant in the kif11 loci that displayed a significant increase in radial glial cell bodies at the ventricular zone of the spinal cord. Kif11, also known as Eg5, is a kinesin-related, plus-end directed motor protein responsible for stabilizing and separating the bipolar mitotic spindle. We show here that Gfap+ radial glial cells express kif11 in the ventricular zone and floor plate. Loss of Kif11 by mutation or pharmacological inhibition with S-trityl-L-cysteine (STLC) results in monoastral spindle formation in radial glial cells, which is characteristic of mitotic arrest. We show that M-phase radial glia accumulate over time at the ventricular zone in kif11 mutants and STLC treated embryos. Mathematical modeling of the radial glial accumulation in kif11 mutants not only confirmed an ~226× delay in mitotic exit (likely a mitotic arrest), but also predicted two modes of increased cell death. These modeling predictions were supported by an increase in the apoptosis marker, anti-activated Caspase-3, which was also found to be inversely proportional to a decrease in cell proliferation. In addition, treatment with STLC at different stages of neural development uncovered two critical periods that most significantly require Kif11 function for stem cell progression through mitosis. We also show that loss of Kif11 function causes specific reductions in oligodendroglia and secondary interneurons and motorneurons, suggesting these later born populations require proper radial glia division. Despite these alterations to cell cycle dynamics, survival, and neurogenesis, we document unchanged cell densities within the neural tube in kif11 mutants, suggesting that a mechanism of compensatory regulation may exist to maintain overall proportions in the neural tube. We propose a model in which Kif11 normally functions during mitotic spindle formation to facilitate the progression of radial glia through mitosis, which leads to the maturation of progeny into specific secondary neuronal and glial lineages in the developing neural tube.

Preference for Type 2 Diabetes Therapies in the United States: A Discrete Choice Experiment.

INTRODUCTION: Type 2 diabetes mellitus (T2DM) is a chronic condition associated with substantial clinical and economic burden. As multiple therapeutic options are available, patient preferences on treatment characteristics are key in T2DM therapeutic decision-making. This study aimed to determine the preferences of US patients with T2DM for therapies recommended for first pharmacologic intensification after metformin. METHODS: As part of a discrete choice experiment, an online survey was designed using literature review and qualitative interview findings. Eligibility was met by US patients with T2DM who were aged 18 years or older with an HbA1c ≥ 6.5%. Anonymized therapy profiles were created from six antidiabetic therapies including oral and injectable semaglutide, dulaglutide, empagliflozin, sitagliptin, and thiazolidinediones. RESULTS: Eligible patients (n = 500) had a mean HbA1c of 7.4%, and a mean BMI of 32.0 kg/m2, the majority of which (72.2%) were injectable-naïve. The treatment characteristic with greatest importance was mode and frequency of administration (35.5%), followed by body weight change (29.2%), cardiovascular event risk (19.1%), hypoglycemic event risk (9.9%), and HbA1c change (6.5%). An oral semaglutide-like profile was preferred by 91.9-70.1% of respondents depending on the comparator agent, and preference was significant in each comparison (p < 0.05); an injectable semaglutide-like profile was preferred by 89.3-55.7% of respondents in each comparison depending on the comparator agent. CONCLUSION: Patients with T2DM in the USA are significantly more likely to prefer oral or injectable semaglutide-like profiles over those of key comparators from the glucagon-like peptide 1 receptor agonist, sodium-glucose cotransporter 2 inhibitor, dipeptidyl peptidase 4 inhibitor, and thiazolidinedione classes.

Essential genes for astroglial development and axon pathfinding during zebrafish embryogenesis.

The formation of the central nervous system depends on the coordinated development of neural and glial cell types that arise from a common precursor. Using an existing group of zebrafish mutants generated by viral insertion, we performed a "shelf-screen" to identify genes necessary for astroglial development and axon scaffold formation. We screened 274 of 315 viral insertion lines using antibodies that label axons (anti-Acetylated Tubulin) and astroglia (anti-Gfap) and identified 25 mutants with defects in gliogenesis, glial patterning, neurogenesis, and axon guidance. We also identified a novel class of mutants affecting radial glial cell numbers. Defects in astroglial patterning were always associated with axon defects, supporting an important role for axon-glial interactions during axon scaffold development. The genes disrupted in these viral lines have all been identified, providing a powerful new resource for the study of axon guidance, glio- and neurogenesis, and neuron-glial interactions during development of the vertebrate CNS.