Effects of Serial Passage on the Characteristics and Cardiac and Neural Differentiation of Human Umbilical Cord Wharton’s Jelly-Derived Mesenchymal Stem Cells
Effects of Serial Passage on the Characteristics and Cardiac and Neural Differentiation of Human Umbilical Cord Wharton’s Jelly-Derived Mesenchymal Stem Cells
Jianchun Lian,1,2 Shijie Lv,3 Chang Liu,1,4 Yang Liu,1 Shujun Wang,1 Xin Guo,1 Feng Nan,5 Hua Yu,3 Xin He,2 Guangwei Sun,1 and Xiaojun Ma1
1Laboratory of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
2The Laboratory Medical College, Dalian Medical University, Dalian 116044, China
3Dalian Maternity & Child Healthcare Hospital, Dalian 116033, China
4University of Chinese Academy of Sciences, Beijing 100049, China
5Department of Orthopedics, The Second Hospital of Dalian Medical University, Dalian 116023, China
Received 16 June 2015; Accepted 31 August 2015
Academic Editor: Franca Fagioli
Copyright © 2016 Jianchun Lian et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background and Objective. It is important to guarantee the quality of stem cells. Serial passage is the main approach to expand stem cells. This study evaluated effects of serial passage on the biological characteristics of human umbilical cord Wharton’s jelly-derived MSCs (WJ MSCs). Methods. Biological properties of WJ MSCs in the early (less than 10 passages, P10), middle (P11–20), and late (more than P20) phases including cell proliferation, cell cycle, phenotype, senescence, oncogene expression, stemness marker expression, and differentiation capacity were evaluated using flow cytometry, real-time PCR, immunocytofluorescence, and western blot. Results. It was found that there were no significant differences in cell proliferation, cell cycle, phenotype, and stemness marker expression in different phases. However, the expression of senescence-related gene, p21, and oncogene, c-Myc, was significantly upregulated in the late phase, which had close relations with the obviously increased cell senescence. Moreover, cardiac differentiation capability of WJ MSCs decreased whereas the propensity for neural differentiation increased significantly in the middle phase. Conclusions. This study reveals that WJ MSCs in the early and middle phases are relatively stable, and effect of serial passage on the lineage-specific differentiation should be considered carefully.
1. Introduction
Human mesenchymal stem cells (MSCs) have great potential in regenerative medicine, because they can self-renew and differentiate into cellular derivations of three primary germ layers, such as neural cells [1], cardiomyocytes [2], and hepatocytes [3]. MSCs reside in many adult organs or tissues, for example, bone marrow (BM) and adipose, and they also exist in birth-associated tissues, such as umbilical cord (UC), placenta, and amniotic fluid [4]. MSCs were isolated initially from BM, but BM aspiration is a highly invasive procedure, which is detrimental for patients [5]. Adipose tissue is thought to be a better source than BM because it can be obtained by a less invasive procedure [6]. However, it is reported that the quality of MSCs derived from BM or adipose tissue may decline with progressive age [7, 8]. Birth-associated tissues were discarded as medical waste before. However, at present, they are gaining popularity as alternative sources of MSCs [9, 10]. In birth-associated tissues accessed, UC Wharton’s jelly-derived MSCs (WJ MSCs) offer the best clinical utility, partly due to their high purity and unique properties [11]. It is reported that WJ MSCs have higher expression of undifferentiated human embryonic stem cell (ESC) markers than BM MSCs, and they also can be induced to be neural progenitors with higher efficiency compared to BM MSCs and adipose-derived MSCs (AD MSCs) [12, 13]. In addition, more and more WJ MSCs are preserved in stem cell banks, which indicates that WJ MSCs have the potential for large-scale applications. Therefore, it appears that WJ MSCs may be an ideal MSC source instead of BM and AD MSCs.
To ensure the accuracy and stability of stem cell research, it is very important to guarantee the quality of cultured stem cells due to the possibility of lost phenotype, malignant transformation, altered lineage-specific differentiation capacity, and so forth during MSC culture in vitro. Serial passage is the main approach to culture MSCs in vitro at present. It has been found that serial passage has different effects on the cellular characteristics of human BM MSCs and AD MSCs [14–16]. However, how serial passage affects the biological characteristics of WJ MSCs is still unclear at present.
Therefore, in this study we investigated effects of serial passage on the specific characteristics of WJ MSCs in the early phase (less than 10 passages, representative passage 7, P7), middle phase (between 10 and 20 passages, P14), and late phase (more than 20 passages, P21) (...truncated)