Disposed earthworm has been used to treat various common ailments including burns, arthritis, itching, and inflammation for thousands of years in China. As their remarkable ability to fully regenerate in a scar-free manner, regenerated tissue homogenate of amputated Eisenia fetida (E. fetida) have been considered as an excellent wound repair therapy in our previous study. We have demonstrated that regenerated earthworm (G-90') can perform higher wound repair ability to non-regeneration tissue (G-90) through significant promotion of cutaneous wound repair in mice after their administration into wound beds. In the present study, we aimed to reveal the mechanism of G-90' and to explore a potential wound healing accelerated strategy. Two functional proteins- HSP70 and lysozyme in G-90' were confirmed by cross-identification of LC-MS/MS and transcriptome analyses. Followed with semi-quantitative PCR and western blot, their expression were validated to up-regulate in 3-day regenerated tissues (G-90'). This study implies the therapeutic potency of G-90' for wound recovery and provides a new strategy to assess other natural materials targeting wound healing with the tail-amputated E .fetida as a model organism.

The lack of adequate human in vitro models that recapitulate the cellular composition and response of the human liver to injury hampers the development of anti-fibrotic drugs. The goal of this study was to develop a human spheroid culture model to study liver fibrosis by using induced pluripotent stem cell (iPSC)-derived liver cells. iPSCs were independently differentiated towards hepatoblasts (iHepatoblasts), hepatic stellate cells (iHSCs), endothelial cells (iECs) and macrophages (iMΦ), before assembly into free floating spheroids by culturing cells in 96-well U-bottom plates and orbital shaking for up to 21 days to allow further maturation. Through transcriptome analysis, we show further maturation of iECs and iMΦ, the differentiation of the iHepatoblasts towards hepatocyte-like cells (iHeps) and the inactivation of the iHSCs by the end of the 3D culture. Moreover, these cultures display a similar expression of cell-specific marker genes (CYP3A4, PDGFRβ, CD31 and CD68) and sensitivity to hepatotoxicity as spheroids made using freshly isolated primary human liver cells. Furthermore, we show the functionality of the iHeps and the iHSCs by mimicking liver fibrosis through iHep-induced iHSC activation, using acetaminophen. In conclusion, we have established a reproducible human iPSC-derived liver culture model that can be used to mimic fibrosis in vitro as a replacement of primary human liver derived 3D models. The model can be used to investigate pathways involved in fibrosis development and to identify new targets for chronic liver disease therapy.

Hepatic stellate cells (HSCs) are central drivers of liver fibrosis, yet their heterogeneity is often overlooked in human liver organoid models. Here, we investigated how HSC-intrinsic variability influences fibrotic phenotypes in multicellular liver organoids using induced pluripotent stem cell-derived HSCs (iHSCs) and primary HSCs (pHSCs). iHSCs derived from two different iPSC lines exhibited distinct differentiation phenotypes towards iHSCs. Consistently, co-culture of the hepatocyte-like cell line HepaRG with these two iHSC populations generated organoids with distinct fibrotic and hepatic features. BJ1-iHSC/HepaRG organoids contained an approximately 2.9-fold higher proportion of CYP3A4-positive cells, whereas Sigma-iHSC/HepaRG organoids showed around a 4-fold higher percentage of Sirius red-positive area. Single-cell RNA analysis further showed that the two iHSC populations differed in cell cycle distribution, HSC-related signatures, extracellular matrix-associated pathways, and matrisome enrichment. Similarly, human pHSCs cultured as organoids with HepaRG showed marked donor-dependent differences at baseline and after single acetaminophen, repeated thioacetamide or transforming growth factor beta treatment. Together, our findings suggest that HSC heterogeneity, whether iPSC-derived or donor-derived, is an important factor in fibrotic output and response variability in human liver organoid models and should be considered in model design, interpretation and comparison between studies.