Biology subjects

Graber, J.

Publications and source records attributed to Graber, J..

3 recordsLinked to original sources

bioRxiv2026

Injury-induced Cxcl11 and neutrophil signaling drive zebrafish kidney regeneration by generating a nephrogenic niche of Fgf and Wnt expression

Adult zebrafish regenerate their kidneys after injury by activating quiescent renal stem cells, however the injury signals that activate kidney stem cells are not known. We show here that an innate immune, cytokine response after tubule injury is required and sufficient to induce adult zebrafish kidney regeneration. An injury reporter zebrafish transgenic, Tg(kim1:mScarlet3), revealed that tubule injury occurred specifically in kidney proximal tubules and was associated with a rapid accumulation of neutrophils and macrophages. Injury also activated a Tg(NFkB:GFP) reporter transgene specifically in kidney tubules where RNA seq revealed NFkB target gene and cytokine expression. Inhibition of NFkB signaling with JSH-23 blocked Tg(NFkB:GFP) reporter activation and also inhibited induction of new nephrons. Systemic injection of the immune activators lipopolysaccharide or zymosan into uninjured fish rapidly induced cytokine expression followed by nephrogenic gene expression and the appearance of new, functional nephrons. Analysis of injury-induced cytokines revealed that several paralogs of cxcl11 were strongly expressed throughout the regeneration response and injection of recombinant Cxcl11 was sufficient to induce FGF-dependent kidney stem cell aggregation, but not Wnt-dependent epithelial differentiation. Kidney injury in zebrafish expressing a neutrophil dominant negative rac2D57N transgene activated Fgf signaling but failed to induce wnt9b or downstream Wnt target genes. Nephrogenic gene expression and epithelial tubule formation was rescued by treatment with the canonical Wnt agonist CHIR. Our findings demonstrate that an injury-induced, sterile immune response regulates kidney regeneration by establishing a nephrogenic niche of Fgf and Wnt signaling that supports tissue-resident kidney stem cell differentiation into functional nephrons.

developmental biology↗

bioRxiv2026

Sexually Dimorphic Response to Dietary Restriction-induced Longevity and Muscle Rejuvenation in Nothobranchius furzeri.

Age-related skeletal muscle decline (sarcopenia) is a major contributor to frailty and mortality during aging, yet the extent to which sex shapes muscle aging and its response to dietary interventions remains poorly understood. Here, we use the short-lived vertebrate Nothobranchius furzeri (African turquoise killifish; ATK) to investigate how sex and intermittent fasting (IF) interact to regulate lifespan and skeletal-muscle aging. We establish and optimize an IF regimen that significantly extends lifespan in both male and female killifish, albeit with classical trade-offs including reduced growth and reproductive output. Despite these costs, IF markedly improves swimming performance in aged animals of both sexes. Structural analyses of killifish on a normal diet reveal pronounced sexual dimorphism in muscle aging. Males exhibit age-associated myofiber hyperplasia, whereas females maintain fiber number but undergo hypertrophic remodeling. IF partially reverses both phenotypes, restoring a more youthful fiber size distribution in both males and females. Single-nucleus RNA sequencing uncovers sex-specific remodeling of muscle-fiber composition in killifish on a normal diet, with females displaying an age-associated shift toward oxidative slow-twitch fibers that is reversed by IF, while males show relatively stable fiber-type proportions under normal and IF feeding regimens. Cell-cell communication analyses further reveal a global decline in intercellular signaling with age, alongside sex-specific restoration of distinct pathways under IF, including axon guidance and IGF signaling in females and metabolic ANGPTL signaling in males. Finally, bulk transcriptomic profiling demonstrates that aging follows largely sexually dimorphic molecular trajectories, whereas IF induces both sex-specific and shared responses. Notably, under IF, both sexes exhibit upregulation of ribosome biogenesis and genes supporting myofibrillar organization and contraction, likely underlying preserved muscle function. Together, these findings demonstrate that IF promotes longevity and muscle health through conserved anabolic mechanisms alongside sex-specific cellular and molecular rejuvenation strategies. Our work highlights the importance of incorporating sex as a biological variable when designing dietary interventions to promote healthy aging.

physiology↗

bioRxiv2025

Cellular heterogeneity and therapeutic response profiling of human IDH+ glioma stem cell cultures

Summary/AbstractGlioblastoma stem cell (GSC) cultures are initiated from glioblastoma (GBM) surgical resection tissue. They can capture and propagate key GBM primary tumor molecular and cellular features. We have deeply characterized four isocitrate dehydrogenase (IDH)-expressing (or IDH+) GSC cultures from unrelated adults to serve as cellular models for the majority of adult primary GBM. We demonstrate that GSC cultures can be continuously propagated in defined, serum-free media and 5% oxygen without requiring specialized growth substrates; have well-defined genomic and mtDNA variants and gene/protein expression profiles; and highly reproducible dose-survival curves when treated with the GBM standard-of-care therapies of ionizing radiation (IR) and temozolomide (TMZ). We also illustrate how expressed lentiviral barcodes, mtDNA variants and single cell gene expression profiling can be used to define and track cellular heterogeneity over 40 days after IR treatment. These well-characterized IDH+ GSC cultures can support many high throughput in vitro assay formats, including xenograft, organoid and other GBM disease modeling protocols. They should prove a useful resource to better understand GBM biology, and to identify new and more effective GBM therapies and treatment regimens. HighlightsO_LIGlioblastoma (GBM)-derived IDH-expressing Glioma Stem Cell (GSC) cultures can capture and propagate GBM genomic variants, gene and protein expression programs. C_LIO_LIMitochondrial DNA (mtDNA) variants identified by high accuracy Duplex DNA sequencing are abundant and sub-clonally organized in GSC cultures. C_LIO_LIGSC cultures have highly reproducible dose-survival curves for ionizing radiation and temozolomide, the GBM standard-of-care therapies. C_LIO_LIGSC culture cellular heterogeneity can be captured, characterized and tracked by using expressed lentiviral barcodes, mtDNA variants and scRNA sequencing. C_LI eTOC blurbIDH-expressing glioma stem cell cultures (GSCs) are experimentally tractable and versatile glioblastoma (GBM) cellular disease models. Deeply characterized GSC cultures can enable new work to understand GBM biology, and help identify new and more effective GBM therapies and treatment regimens. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/667532v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@82aceeorg.highwire.dtl.DTLVardef@1277c18org.highwire.dtl.DTLVardef@144188eorg.highwire.dtl.DTLVardef@1a84bb3_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗