Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 14, 2018; 24(30): 3398-3413
Published online Aug 14, 2018. doi: 10.3748/wjg.v24.i30.3398
Novel sericin-based hepatocyte serum-free medium and sericin’s effect on hepatocyte transcriptome
Yun Huang, Qing Peng, Hai-Yan Li, Zhi-Dong Jia, Yang Li, Yi Gao
Yun Huang, Qing Peng, Hai-Yan Li, Zhi-Dong Jia, Yang Li, Yi Gao, Department of Hepatobiliary Surgery II, Guangdong Provincial Research Center for Artificial Organ and Tissue Engineering, Guangzhou Clinical Research and Transformation Center for Artificial Liver, Institute of Regenerative Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, Guangdong Province, China
Yi Gao, State Key Laboratory of Organ Failure Research, Southern Medical University, Guangzhou 510515, Guangdong Province, China
Author contributions: Huang Y performed the whole process of this study, including the concept, study design, operation of the experiments, data analysis, statistics and article drafting; Peng Q assisted with study design and critical revision of the article; Li HY, Jia ZD and Li Y assisted with the operation of the experiments; Gao Y laid out the concept and performed the critical revision and final approval of the article.
Supported by the National Natural Science Foundation of China, No. 81470875; the Natural Science Foundation of Guangdong Province, No. 2014A030312013; Science and Technology Planning Project of Guangdong Province, No. 2014B020227002, No. 2015B090903069, and No. 2015B020229002; and Science and Technology Program of Guangzhou, No. 201604020002.
Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Yi Gao, MD, PhD, Chief Doctor, Professor, Surgeon, Department of Hepatobiliary Surgery II, Guangdong Provincial Research Center for Artificial Organ and Tissue Engineering, Guangzhou Clinical Research and Transformation Center for Artificial Liver, Institute of Regenerative Medicine, Zhujiang Hospital of Southern Medical University, 253 Middle Industrial Avenue, Guangzhou 510515, Guangdong Province, China. gaoyi6146@163.com
Telephone: +86-18922345399 Fax: +86-20-61643207
Received: May 11, 2018
Peer-review started: May 11, 2018
First decision: June 11, 2018
Revised: June 17, 2018
Accepted: June 28, 2018
Article in press: June 28, 2018
Published online: August 14, 2018
Processing time: 94 Days and 20.1 Hours
ARTICLE HIGHLIGHTS
Research background

A serum-free medium suitable for hepatocyte culture in the bioartificial liver support system (BALSS) has been needed within recent decades, but few studies have focused on the development of hepatocyte serum-free medium. Sericin was proven to promote cell attachment and proliferation, but the mechanism is not clarified.

Research motivation

Poor adherence and proliferation were often observed in the serum-free culture. Sericin has the ability to promote the attachment and proliferation of several mammalian cells, so it was selected as a key supplement in our serum-free medium. The mechanism how sericin promotes the attachment and proliferation of hepatocytes was not clarified. So, the effect of sericin on the hepatocyte transcriptome was explored in this study.

Research objectives

To develop a novel serum-free hepatocyte medium and to clarify the effect of sericin on the hepatocyte transcriptome.

Research methods

Part 1 is a controlled trial comparing the novel serum-free medium and other media: C3A cells were cultured in our novel serum-free medium, HepatoZYME, complete medium (DMEM/F12 with 100 mL/L FBS), and DMEM/F12, then cell attachment, proliferation, and function as well as the biocompatibility of the media were assessed. Part 2 is a comparative study of serum-free media with or without 2 mg/mL sericin: The effect of sericin on C3A growth was assessed by cell viability and proliferation, the effect of sericin on C3A cell cycle distribution was determined by flow cytometry, and the effect of sericin on the C3A transcriptome was assessed by gene-chip array and RT-qPCR.

Research results

More C3A cells attached to the plate containing our serum-free medium than to those containing HepatoZYME and DMEM/F12 at 24 h post-seeding. Both the viability and proliferation rate of C3A cells in sericin-based serum-free medium were superior to those of cells in HepatoZYME and DMEM/F12. The content of albumin and urea in our serum-free medium was significantly higher than that in HepatoZYME and DMEM/F12 throughout the whole culture period, and was similar to that in complete medium at day 3, 4, and 5. In part 2, cell viability and proliferation were greater in the presence of 2 mg/mL sericin, as was the proportion of cells in S phase. Gene-chip array analysis indicated that the expression of CCR6, EGFR, and FOS were up-regulated by 2 mg/mL sericin, and RT-qPCR revealed that the expression of CCR6, EGFR, FOS, AKT1, JNK1, NFkB1, MMP-9, MEK2, ERK1/2 and C-MYC was up-regulated by 2 mg/mL sericin.

Research conclusions

We developed a novel serum-free hepatocyte medium in this research and demonstrated that sericin probably enhances cell attachment through the CCR6-Akt-JNK-NF-kB pathway and promotes cell proliferation through CCR6-mediated activation of the ERK1/2-MAPK pathway.

Research perspectives

In future studies, we will use the novel serum-free hepatocyte medium in large scale hepatocyte culture in the BALSS and assess the biocompatibility, immunogenicity and allergenicity in animal and clinical experiments. To clarify the mechanism of promotion of sericin on cell attachment and proliferation, we are going to study the protein level expression of CCR6-Akt-JNK-NF-kB pathway and ERK1/2-MAPK pathway components.