en Stem Cell Stem Cell Original Article Original Article <div style="text-align: justify;">The capacity of human umbilical cord mesenchymal stem cells (hUMSCs)&nbsp; for migration and homing is very important in regenerative medicine. A detoxified derivative of lipopolysaccharides (LPS) that lacks many of the endotoxic properties of LPS is monophosphoryl lipid A (MPLA).&nbsp; Effects of MPLA on the induction of MSCs migration, have not yet been studied. Also, studies have shown that supernatant of <em>Lactobacillus acidophilus</em> (SLA) culture medium, can stimulate the proliferation of macrophages and lymphocytes <em>in vitro</em> by affecting the properties of the chemotaxis and angiogenesis. Our present study aimed to understanding of the migration of hUMSCs during treatment with MPLA and LS, separately. HUMSCs were isolated from human umbilical cord and were characterized by investigating surface markers (CD105, CD90, anti-CD29, CD45, and CD34) and their differentiation into adipogenic and osteogenic lineages. HUMSCs were treated with MPLA (10^-3 &micro;g/ml) and SLA (3 &micro;l/ml). The morphological changes were not observed in both treated MSCs. <em>Expression </em><em>levels</em>&nbsp;of migration&nbsp;<em>markers were </em>determined by quantitative reverse transcription PCR analysis on 2, 4, 6 days after treatment. Results showed that <em>VEGF</em> and <em>MMP-2</em> but not <em>CXCR-4</em> was increased in the presence of both treatments. Also, SLA led to a decrease and increase of the expression of <em>VLA-4</em> and <em>VCAM-1</em>, respectively, while MPLA increased both <em>VLA-4</em> and <em>VCAM-1</em> expression.Therefore, it can be suggested that MPLA has more prominent results than SLA, but both treatments can probably be considered as an inducing factor in migration.</div> Human umbilical cord mesenchymal stem cells, monophosphoryl lipid A, Lactobacillus acidophilus, VCAM-1 154 161 http://ijmcmed.org/browse.php?a_code=A-10-1640-2&slc_lang=en&sid=1 Ali Shojaeian ali.shojaeian65@gmail.com 100319475328460015601 100319475328460015601 No Department of Molecular Medicine, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran. Ameneh Mehri-Ghahfarrokhi ameneh.mehri.96@gmail.com 100319475328460015602 100319475328460015602 No Department of Molecular Medicine, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran. Mehdi Banitalebi-Dehkordi mehdibanitalebi@gmail.com 100319475328460015603 100319475328460015603 Yes Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran