ABS 028: Defining the Role of Zfp800 in Liver Development and Function

Shreeya Moolamalla ¹, Amelia Cephas ¹, Kathleen DelGiorno ¹

¹ Vanderbilt University

The Van Wickle Journal (2026) Volume 2, ABS028

Introduction: Zinc finger proteins play a pivotal role in tissue development and differentiation. Zinc finger protein 800’s loss in human intestinal organoids results in increased serotonin-producing enterochromaffin cells. Up to 95% of circulating serotonin is derived from the intestines. Serotonin regulates metabolism, detoxification, and cell proliferation in the liver. It is also highly expressed there during embryonic liver development day 14-18 (E14–E18). Therefore, we hypothesize that the loss of Zinc Finger Protein 800 in mice would lead to increased serotonin signaling, leading to elevated cell proliferation, metabolism and detoxification. Further, Zinc Finger Protein 800 loss could impact the differentiation of cells in the liver as it does in other organs. Hepatocyte maturation relies on the transcription factor Hepatocyte Nuclear Factor Alpha, which transitions from its fetal (P2) to adult (P1) isoform, thereby possibly altering proper liver maturation and function. Perhaps the loss of Zinc Finger Protein 800 could prolong progenitor-like states and alter differentiation in other specialized cells like Kupffer cells, Sinusoidal cells, etc. To examine whether there are differences in function, maturation and differentiation in Zinc Finger Protein 800 -/- knockout compared to wild-type wildtype liver tissue, we conducted histological staining and qRT-PCR. This study seeks to characterize Zinc Finger Proteins’s role in coordinating cellular differentiation and function within the gut–liver axis.

Methods: Liver tissues were collected from postnatal day 19–20 Zfp800 wild-type and knockout mice to evaluate whether loss of Zfp800 altered liver morphology, cellular identity, or gene expression. Samples were fixed, sectioned, stained, and imaged using a slide scanner. Hematoxylin and eosin staining was used to assess overall tissue morphology, while immunofluorescence and Immunohistochemistry were used to visualize specific liver cell populations and protein markers. F4/80 and CK19 staining were quantified using QuPath analysis by segmenting tissue regions, excluding poor-quality areas, detecting nuclei, and calculating the percentage of positively stained cells relative to total cells. Quantitative real-time PCR was performed on dissected liver tissue to compare mRNA expression between wild-type and knockout samples. RNA was extracted, purified, quantified, and analyzed in triplicate using gene-specific primers, with RPLPO used as the housekeeping control for relative expression analysis.

Results: Loss of Zfp800 did not cause overt disruption of overall liver architecture at P20, as shown by H&E staining, HNF4α staining, and E-cadherin staining. However, Zfp800 knockout livers showed altered cellular composition, including changes in macrophage/Kupffer cell and ductal-associated populations marked by F4/80 and CK19. qRT-PCR further showed that Zfp800 loss altered expression of genes involved in metabolism, differentiation, proliferation, serotonin signaling, and liver cell identity. Together, these findings suggest that Zfp800 loss does not grossly disrupt liver morphology but may influence postnatal liver cell programs and metabolic signaling pathways.

Discussion: These findings suggest that Zfp800 may influence postnatal liver development through subtle changes in cellular composition, metabolic gene programs, and serotonin-associated signaling rather than gross disruption of liver morphology. The significant developmental enrichment of Zfp800 in fetal liver further supports a potential role in early organ maturation. Future work will increase sample size, analyze consistent liver lobes, quantify E-cadherin-based cell size, and expand staining for Kupffer cells, sinusoidal endothelial cells, stellate cells, and pancreatic hormone markers across E18, P1, P20, and adult stages to clarify how Zfp800 loss affects liver and pancreas development.