Biology subjects

Kriz, J.

Publications and source records attributed to Kriz, J..

4 recordsLinked to original sources

bioRxiv2026

Heterogeneity in cell-cycle dynamics of synthetic mRNA-induced β-cell proliferation

Adult pancreatic {beta}-cells are mostly locked in quiescence, limiting large-scale analysis of their cell cycle. To overcome this limitation, we used synthetic in vitro transcribed mRNAs encoding Cyclin D1 and CDK4 to induce proliferation in up to 70% of primary rat {beta}-cells. Flow cytometry-based analysis of cell-cycle markers revealed substantial heterogeneity in {beta}-cell cell-cycle progression, identifying five distinct groups of proliferating {beta}-cells based on G1 entry timing. Total cell-cycle length ranged from approximately 26 to 34 hours and was primarily determined by variability in G1 duration (13-19 hours). In the fastest-dividing {beta}-cells, G1, S, and G2M lasted approximately 13, 6, and 7 hours, respectively, whereas later-entering {beta}-cells exhibited progressively longer G1 phase. Additionally, we identified a small {beta}-cell subpopulation that failed to complete division and may have exited the cell cycle. These findings reveal cell-cycle entry and G1 progression as a major source of heterogeneity in {beta}-cell proliferation and provide quantitative benchmark for developing strategies to enhance controlled {beta}-cell regeneration in diabetes.

cell biology↗

bioRxiv2026

Stimulation of rodent and human beta-cell proliferation using synthetic modified mRNAs encoding cell cycle regulators

Pancreatic beta cells exhibit marked resistance to proliferation, posing a barrier to therapeutic strategies aimed at restoring beta-cell mass in diabetes. Here, we present a transient, non-integrative approach to stimulate beta-cell proliferation using in vitro transcribed (IVT) mRNAs encoding cell cycle regulators. In rodent beta cells and human-beta cell derived EndoC-BH5 cells, chemically modified IVT mRNAs activated cell cycle entry and subsequent mitosis. A single dose of cyclin D1 and CDK4 IVT mRNAs nearly doubled the number of rat beta cells. However, achieving cell division in human beta cells required co-delivery of MYC IVT mRNA. The mitogenic response of beta cells peaked within 36-60 hours, and declined thereafter, reflecting the transient nature of IVT mRNA. Transcriptomic profiling revealed temporary activation of proliferative pathways and reversible downregulation of beta-cell maturation markers. Importantly, we detected no evidence of sustained proliferation. Our findings demonstrate that mRNA-based delivery of cell cycle regulators can overcome the intrinsic cell cycle block in beta cells and may provide a controllable approach for beta-cell regeneration.

bioengineering↗

bioRxiv2022

Therapeutic trial of anle138b in mouse models of genetic prion disease

Phenotypic screening has yielded small molecule inhibitors of prion replication that are effective in vivo against certain prion strains but not others. Here we sought to test the small molecule anle138b in multiple mouse models of prion disease. In mice inoculated with the RML strain of prions, anle138b doubled survival and durably suppressed astrogliosis measured by live animal bioluminescence imaging. In knock-in mouse models of the D178N and E200K mutations that cause genetic prion disease, however, we were unable to identify a clear, quantifiable disease endpoint against which to measure therapeutic efficacy. Among untreated animals, the mutations did not impact overall survival, and bioluminescence remained low out to >20 months of age. Vacuolization and PrP deposition were observed in some brain regions in a subset of mutant animals, but appeared unable to carry the weight of a primary endpoint in a therapeutic study. We conclude that not all animal models of prion disease are suited to well-powered therapeutic efficacy studies, and care should be taken in choosing the models that will support drug development programs.

neuroscience↗

bioRxiv2020

Prion protein lowering is a disease-modifying therapy across prion strains, disease stages, and endpoints

Lowering of prion protein (PrP) expression in the brain is a genetically validated therapeutic hypothesis in prion disease. We recently showed that antisense oligonucleotide (ASO)-mediated PrP suppression extends survival and delays disease onset in intracerebrally prion-infected mice in both prophylactic and delayed dosing paradigms. Here, we examine the efficacy of this therapeutic approach across diverse paradigms, varying the dose and dosing regimen, prion strain, treatment timepoint, and examining symptomatic, survival, and biomarker readouts. We recapitulate our previous findings with additional PrP-targeting ASOs, and demonstrate therapeutic benefit against four additional prion strains. We demonstrate that less than 25% PrP suppression is sufficient to extend survival and delay symptoms in a prophylactic paradigm. Rise in both neuroinflammation and neuronal injury markers can be reversed by a single dose of PrP-lowering ASO administered after the detection of pathological change. Chronic ASO-mediated suppression of PrP beginning at any time up to early signs of neuropathology confers benefit similar to constitutive heterozygous PrP knockout. Remarkably, even after emergence of frank symptoms including weight loss, a single treatment prolongs survival by months in a subset of animals. These results support ASO-mediated PrP lowering, and PrP-lowering therapeutics in general, as a promising path forward against prion disease.

neuroscience↗