Lithium induces mesenchymal-epithelial differentiation during human kidney development by activation of the Wnt signalling system

Lithium chloride promotes mesenchymal-epithelial transition in murine cutaneous wound healing via inhibiting CXCL9 and IGF2

Cutaneous wound healing is a challenge in plastic and reconstructive surgery. In theory, cells undergoing mesenchymal transition will achieve re-epithelialization through mesenchymal-epithelial transition at the end of wound healing. But in fact, some pathological stimuli will inhibit this biological process and result in scar formation. If mesenchymal-epithelial transition can be activated at the corresponding stage, the ideal wound healing may be accomplished. Two in vivo skin defect mouse models and dermal-derived mesenchymal cells were used to evaluate the effect of lithium chloride in wound healing. The mesenchymal-epithelial transition was detected by immunohistochemistry staining. In vivo, differentially expressed genes were analysed by transcriptome analyses and the subsequent testing was carried out. We found that lithium chloride could promote murine cutaneous wound healing and facilitate mesenchymal-epithelial transition in vivo and in vitro. In lithium chloride group, scar area was smaller and the collagen fibres are also orderly arranged. The genes related to mesenchyme were downregulated and epithelial mark genes were activated after intervention. Moreover, transcriptome analyses suggested that this effect might be related to the inhibition of CXCL9 and IGF2, subsequent assays demonstrated it. Lithium chloride can promote mesenchymal-epithelial transition via downregulating CXCL9 and IGF2 in murine cutaneous wound healing, the expression of IGF2 is regulated by β-catenin. It may be a potential promising therapeutic drug for alleviating postoperative scar and promoting re-epithelialization in future.

Tsc2 mutation induces renal tubular cell nonautonomous disease

TSC renal cystic disease is poorly understood and has no approved treatment. In a new principal cell-targeted murine model of Tsc cystic disease, the renal cystic epithelium is mostly composed of type A intercalated cells with an intact Tsc2 gene confirmed by sequencing, although these cells exhibit a Tsc-mutant disease phenotype. We used a newly derived targeted murine model in lineage tracing and extracellular vesicle (EV) characterization experiments and a cell culture model in EV characterization and cellular induction experiments to understand TSC cystogenesis. Using lineage tracing experiments, we found principal cells undergo clonal expansion but contribute very few cells to the cyst. We determined that cystic kidneys contain more interstitial EVs than noncystic kidneys, excrete fewer EVs in urine, and contain EVs in cyst fluid. Moreover, the loss of Tsc2 gene in EV-producing cells greatly changes the effect of EVs on renal tubular epithelium, such that the epithelium develops increased secretory and proliferative pathway activity. We demonstate that the mTORC1 pathway activity is independent form the EV production, and that the EV effects for a single cell line can vary significantly. TSC cystogenesis involves significant contribution from genetically intact cells conscripted to the mutant phenotype by mutant cell derived EVs.

Lithium preserves peritoneal membrane integrity by suppressing mesothelial cell αB-crystallin

Life-saving renal replacement therapy by peritoneal dialysis (PD) is limited in use and duration by progressive impairment of peritoneal membrane integrity and homeostasis. Preservation of peritoneal membrane integrity during chronic PD remains an urgent but long unmet medical need. PD therapy failure results from peritoneal fibrosis and angiogenesis caused by hypertonic PD fluid (PDF)-induced mesothelial cytotoxicity. However, the pathophysiological mechanisms involved are incompletely understood, limiting identification of therapeutic targets. We report that addition of lithium chloride (LiCl) to PDF is a translatable intervention to counteract PDF-induced mesothelial cell death, peritoneal membrane fibrosis, and angiogenesis. LiCl improved mesothelial cell survival in a dose-dependent manner. Combined transcriptomic and proteomic characterization of icodextrin-based PDF-induced mesothelial cell injury identified αB-crystallin as the mesothelial cell protein most consistently counter-regulated by LiCl. In vitro and in vivo overexpression of αB-crystallin triggered a fibrotic phenotype and PDF-like up-regulation of vascular endothelial growth factor (VEGF), CD31-positive cells, and TGF-β-independent activation of TGF-β-regulated targets. In contrast, αB-crystallin knockdown decreased VEGF expression and early mesothelial-to-mesenchymal transition. LiCl reduced VEGF release and counteracted fibrosis- and angiogenesis-associated processes. αB-crystallin in patient-derived mesothelial cells was specifically up-regulated in response to PDF and increased in peritoneal mesothelial cells from biopsies from pediatric patients undergoing PD, correlating with markers of angiogenesis and fibrosis. LiCl-supplemented PDF promoted morphological preservation of mesothelial cells and the submesothelial zone in a mouse model of chronic PD. Thus, repurposing LiCl as a cytoprotective PDF additive may offer a translatable therapeutic strategy to combat peritoneal membrane deterioration during PD therapy.

Generation of hepatobiliary organoids from human induced pluripotent stem cells

BACKGROUND & AIMS

Human induced pluripotent stem cell (hiPSC)-derived liver modeling systems have the potential to overcome the shortage of donors for clinical application and become a model for drug development. Although several strategies are available to generate hepatic micro-tissues, few have succeeded in generating a liver organoid with hepatobiliary structure from hiPSCs.

METHODS

At differentiation stages I and II (day 1-15), 25% of mTeSR™ culture medium was added to hepatic differentiation medium to induce endodermal and mesodermal commitment and thereafter hepatic and biliary co-differentiation. At stage III (day 15-45), 10% cholesterol⁺ MIX was added to the maturation medium to promote the formation and maturation of the hepatobiliary organoids. Phenotypes and functions of organoids were determined by specific markers and multiple functional assays both in vitro and in vivo.

RESULTS

In this system, hiPSCs were induced to form 3D hepatobiliary organoids and to some extent recapitulated key aspects of early hepatogenesis in a parallel fashion. The organoids displayed a series of functional attributes. Specifically, the induced hepatocyte-like cells could take up indocyanine green, accumulate lipid and glycogen, and displayed appropriate secretion ability (albumin and urea) and drug metabolic ability (CYP3A4 activity and inducibility); the biliary structures in the system showed gamma glutamyltransferase activity and the ability to efflux rhodamine and store bile acids. Furthermore, after transplantation into the immune-deficient mice, the organoids survived for more than 8 weeks.

CONCLUSION

This is the first time that functional hepatobiliary organoids have been generated from hiPSCs. The organoid model will be useful for in vitro studies of the molecular mechanisms of liver development and has important potential in the therapy of liver diseases.

LAY SUMMARY

Herein, we established a system to generate human induced pluripotent stem cell-derived functional hepatobiliary organoids in vitro, without any exogenous cells or genetic manipulation. To some extent this model was able to recapitulate several key aspects of hepatobiliary organogenesis in a parallel fashion, holding great promise for drug development and liver transplantation.

Growing a new human kidney

There are 3 reasons to generate a new human kidney. The first is to learn more about the biology of the developing and mature organ. The second is to generate tissues with which to model congenital and acquired kidney diseases. In particular, growing human kidneys in this manner ultimately should help us understand the mechanisms of common chronic kidney diseases such as diabetic nephropathy and others featuring fibrosis, as well as nephrotoxicity. The third reason is to provide functional kidney tissues that can be used directly in regenerative medicine therapies. The second and third reasons to grow new human kidneys are especially compelling given the millions of persons worldwide whose lives depend on a functioning kidney transplant or long-term dialysis, as well as those with end-stage renal disease who die prematurely because they are unable to access these treatments. As shown in this review, the aim to create healthy human kidney tissues has been partially realized. Moreover, the technology shows promise in terms of modeling genetic disease. In contrast, barely the first steps have been taken toward modeling nongenetic chronic kidney diseases or using newly grown human kidney tissue for regenerative medicine therapies.

EYA1 promotes cell migration and tumor metastasis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) patients are at high risk for both local recurrence and distant metastasis and tightly associated with poor prognosis. Exploring the molecular mechanism will provide a new opportunity in developing personal treatment for advanced HCC patients. As a critical member of the Retinal Determination Gene Network (RDGN), EYA1 has been identified as a tumor promoter in various cancers; however, its role in HCC has never been investigated. The present study was aimed to explore the role of EYA1 in HCC development. By analyzing public microarray datasets, we found that the EYA1 mRNA level was enhanced in HCC, which was significantly correlated with an aggressive phenotype and poor prognosis. Besides, EYA1 was coordinated with the fibronectin type III domain containing 3B (FNDC3B) to promote the migration and invasion of HCC cells. Western blot assays indicated that EYA1 not only increased the abundance of FNDC3B but also contributed to Epithelial-Mesenchymal Transition (EMT)-like phenotype change, like increased N-cadherin and decreased E-cadherin expression. Collectively, this study suggested that EYA1 activated FNDC3B to promote the migration and invasion in HCC. The aberrant expressions of EYA1 and FNDC3B may become the poor predictors for HCC patients.

[Lithium chloride arrests HK-2 cell cycle in G2 phase through AKT/GSK-3β signal pathway]

OBJECTIVE

To investigate the effect of lithium chloride (LiCl) on cell cycle of HK-2 cells and explore the possible pathways involved.

METHODS

HK-2 cells were treated with LiCl at different concentrations (5, 12.5, 20, and 25 mmol/L) for 12, 24, 48, or 72 h, and the changes in cell cycle and viability were detected using flow cytometry and CCK-8 assay, respectively. Western blotting was used to analyze the changes in the expressions of cyclin B1 and CDK1 (the two G2 phase-related proteins) and those of AKT/GSK-3β signaling pathway-related proteins in the treated cells.

RESULTS

LiCl treatment time- and concentration-dependently increased HK-2 cell percentage in G2 phase and decreased the cell vitality. The expressions of cyclin B1, CDK1, p-GSK-3β, and β-catenin increased and the expression of p-AKT decreased significantly in the cells as LiCl treatment time and concentration increased.

CONCLUSION

LiCl may cause HK-2 cell cycle arrest in G2 phase through activation of the AKT/GSK-3β signaling pathway.

[Lithium chloride arrests HK-2 cell cycle in G2 phase through AKT/GSK-3β signal pathway]

OBJECTIVE

To investigate the effect of lithium chloride (LiCl) on cell cycle of HK-2 cells and explore the possible pathways involved.

METHODS

HK-2 cells were treated with LiCl at different concentrations (5, 12.5, 20, and 25 mmol/L) for 12, 24, 48, or 72 h, and the changes in cell cycle and viability were detected using flow cytometry and CCK-8 assay, respectively. Western blotting was used to analyze the changes in the expressions of cyclin B1 and CDK1 (the two G2 phase-related proteins) and those of AKT/GSK-3β signaling pathway-related proteins in the treated cells.

RESULTS

LiCl treatment time- and concentration-dependently increased HK-2 cell percentage in G2 phase and decreased the cell vitality. The expressions of cyclin B1, CDK1, p-GSK-3β, and β-catenin increased and the expression of p-AKT decreased significantly in the cells as LiCl treatment time and concentration increased.

CONCLUSION

LiCl may cause HK-2 cell cycle arrest in G2 phase through activation of the AKT/GSK-3β signaling pathway.