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Biology subjects

Zion, E.

Publications and source records attributed to Zion, E..

2 recordsLinked to original sources

A kidney specific mouse model to study the effects of in vivo induction of Yamanaka factors

IntroductionMaladaptive repair after acute kidney injury (AKI) leads to fibrosis and chronic kidney disease (CKD). Improving the resilience and stimulating tissue repair after injury is crucial to prevent AKI-to-CKD transition. Using a combination of transcription factors (Yamanaka factors Oct4, Klf4 and Sox2, "OKS") to partially reprogram tissues and enhance regeneration in vivo, could be a promising approach as shown by amelioration after various organ injury, yet not investigated for AKI to date. MethodsWe used a ubiquitously and kidney-specific transgenic mouse model to investigate OKS expression in kidney. In a kidney-specific model using Pax8-Cre, we then induced AKI via aristolochic acid (AA), simultaneously expressing OKS to determine potential protective effects after kidney injury. ResultsWe show that a ubiquitously expressing OKS-mouse model was not suitable due to toxic effects and limited kidney expression. In the Pax8-Cre mouse model, we observed expression almost exclusively to proximal tubules. While induction for more than 3 days caused dysplastic tumor formation, an induction regimen limited to 3 days was not able to improve phenotypic outcome after AA-injury. ConclusionPartial reprogramming of the kidney using OKS is feasible; however, it requires a delicate balance to the risk of oncogenic transformation. Determine a dose that effectively promotes repair without crossing the threshold into harmful effects remains a major challenge, posing significant safety concerns for translating the approach to humans in the near future.

developmental biology↗

Asymmetric histone inheritance regulates stem cell fate in Drosophila midgut

A fundamental question in developmental biology is how distinct cell fates are established and maintained through epigenetic mechanisms in multicellular organisms. Here, we report that preexisting (old) and newly synthesized (new) histones H3 and H4 are asymmetrically inherited by the distinct daughter cells during asymmetric division of Drosophila intestinal stem cells (ISCs). By contrast, in symmetrically dividing ISCs that produce two self-renewed stem cells, old and new H3 and H4 show symmetric inheritance patterns. These results indicate that asymmetric histone inheritance is tightly associated with the distinct daughter cell fates. To further understand the biological significance of this asymmetry, we express a mutant histone that compromises asymmetric histone inheritance pattern. We find increased symmetric ISC division and ISC tumors during aging under this condition. Together, our results demonstrate that asymmetric histone inheritance is important for establishing distinct cell identities in a somatic stem cell lineage, consistent with previous findings in asymmetrically dividing male germline stem cells in Drosophila. Therefore, this work sheds light on the principles of histone inheritance in regulating stem cell fate in vivo.

developmental biology↗