Evaluation of 3D re-cellularized tissue engineering: a drug-induced hepatotoxicity model for hepatoprotectant research

Kuhuang injection exerts a protective effect by activating PPAR-γ in an in vitro model of chlorpromazine-induced cholestatic liver injury constructed by tissue engineering

CONTEXT

Kuhuang (KH) injection is a widely used anticholestatic drug in the clinic and the mechanisms are still unclear.

OBJECTIVE

This study uses a new 3D tissue-engineered (TE) liver platform to study the ability of kuhuang to ameliorate liver injury induced by chlorpromazine (CPZ) and the possible mechanisms involved.

MATERIALS AND METHODS

The TE livers (n = 25) were divided into 5 groups (n = 5 livers/group) as 3D, 3D + CPZ, 3D + CPZ + KH, 3D + CPZ + GW9662 (a PPARγ inhibitor) and 3D + CPZ + KH + GW9662. The treatments with kuhuang (1 mg/mL) and GW9662 (10 μmol/L) were given to the desired groups on the 7th day of the experimental process. 20 μmol/L CPZ was added on the 8th day.

RESULTS

According to the 2D experimental results, the minimum effective concentration of kuhuang is 10 μg/mL and the optimal effective concentration is 1 mg/mL. Kuhuang ameliorated tissue damage in the TE livers both in terms of tissue structure and culture supernatant. Kuhuang significantly reduced TBA accumulation (38%) and downregulated CYP7A1 (38%) and CYP8B1 (79%). It reduced hepatic levels of ROS (14%), MDA (27%) but increased the levels of GSH (41%), SOD (12%), BSEP (4.4-fold), and MRP2 (74%). Moreover, kuhuang downregulated DR5 (99%) but increased the mRNA expression of PPARγ (4-fold). Molecular docking analyses determined the bioactivity of the active compounds of kuhuang through their specific bindings to PPARγ.

CONCLUSIONS

Kuhuang could alleviate CPZ-induced cholestatic liver injury by activating PPARγ to reduce oxidative stress. Applying kuhuang for the treatment of CPZ-induced liver injury could be suggested.

Triptolide regulates oxidative stress and inflammation leading to hepatotoxicity via inducing CYP2E1

Triptolide (TP), the main active compound extracted from medicine-tripterygium wilfordii Hook f. (TWHF). It has anti-tumor and immunomodulatory properties. Our study aimed to investigate the mechanisms of hepatotoxicity treated with TP in vivo and in vitro, as well as their relationship with the NF-κB (p65) signal pathway; and to assess TP-induced hepatotoxicity after CYP2E1 modulation by the known inhibitor, clomethiazole, and the known inducer, pyrazole. Mice were given TP to cause liver injury and IHHA-1 cells were given TP to cause hepatocyte injury. The enzyme activity and hepatotoxicity changed dramatically when the CYP2E1 inhibitor and inducer were added. In comparison to the control group, the enzyme inducer increased the activity of CYP2E1, whereas the enzyme inhibitor had the opposite effect. Our findings suggest that TP is an inducer of CYP2E1 via a time-dependent activation mechanism. In addition, TP can promote oxidative stress, inflammatory and involving the NF-κB (p65) signal pathway. Therefore, we used triptolide to stimulate C57 mice and IHHA-1 cells to determine whether TP can promote oxidative stress and inflammation by activating CYP2E1 in response to exacerbated liver damage and participate in NF-κB (p65) signaling pathway.

Ready to go 3D? A semi-automated protocol for microwell spheroid arrays to increase scalability and throughput of 3D cell culture testing

3-dimensional (3D) cell cultures are being increasingly recognized as physiologically more relevant in vitro models than traditional monolayer cultures, because they better mimic in vivo-like microenvironment, cell-cell and cell-extracellular matrix interactions. Nevertheless, the broader use of 3D models might be limited by requirements for special consumables, equipment, or skills for 3D cell cultures, and by their limited throughput and scalability. In this study, we optimized and adapted a commercially available agarose-micromolding technique to produce scaffold-free spheroid cultures. Brightfield microscopy was used for routine nondestructive and noninvasive evaluation of spheroid formation and growth. The workflow is compatible with manual, as well as high speed automated microscopic image acquisition, and it is supplemented with an in-house developed macro 'Spheroid_Finder' for open source software Fiji to facilitate rapid automated image analysis. This protocol was used to characterize and quantify spheroid formation and growth of two different hepatic cell lines, hTERT immortalized, but non-cancerous, adult human liver stem cell line HL1-hT1, and human hepatocellular carcinoma cell line HepG2, as well as their responses to a model antiproliferative and cytotoxic agent, 5-fluorouracil. The complete protocol provides a simple and ready-to-use solution to initiate scaffold-free spheroid cultures in any laboratory with standard equipment for mammalian in vitro cell culture work. Thus, it allows to increase throughput and scale of spheroid culture experiments, which can be greatly utilized in different areas of biomedical, pharmaceutical and toxicological research.

2'-Hydroxychalcone Induced Cytotoxicity via Oxidative Stress in the Lipid-Loaded Hepg2 Cells

Licorice is a common herb used in traditional Chinese medicine, and has been widely used clinically. Physiologically, although it is relatively safe, licorice-induced hepatotoxicity in the presence of other diseases needs to be evaluated. The present study was conducted to investigate the toxicological effects of the bioactive components of licorice in HepG2 cells cultured with or without free fatty acid (FFA). The compounds, isoliquiritigenin, licorice chalcone A, bavachalcone, and 2′-hydroxy chalcone (2′-HC) inhibited cell proliferation at certain concentrations in lipid loaded cells with limited effects on the normal cells. The representative compound 2′-HC (at a concentration of ≥ 20µM) increased the oxygen consumption rate, ATP production, mitochondrial membrane potential, generation of total and mitochondrial reactive oxygen species (ROS) production, and expression of inflammatory cytokines (TNF-α, IL-6, and IL-8) and Caspase-9 protein; and reduced the expression of SOD1. In addition, we found exaggerated lipid accumulation in HepG2 cells treated with FFA. Our results suggest that 2′-HC at a concentration of ≥ 20µM might cause damage to the hepatocytes. The toxicity may be related to excess ROS production and inadequate SOD1 expression, leading to apoptosis, inflammation, and cellular dysfunctions.