Overexpression of dnIKK in mesenchymal stem cells leads to increased migration and decreased invasion upon TNFα stimulation

• Published in: Biochemical and biophysical research communications Vol. 436; no. 2; pp. 265 - 270
• Main Authors: Haasters, Florian, Prall, Wolf Christian, Westphal, Ines, Böcker, Wolfgang, Padula, Daniela, Mutschler, Wolf, Docheva, Denitsa, Schieker, Matthias
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 28.06.2013
• Subjects: Cell Line; Cell Movement - drug effects; Chemotaxis - drug effects; Gene Expression - drug effects; Humans; I-kappa B Kinase - genetics; I-kappa B Kinase - metabolism; IKK-2; Immunohistochemistry; Invasion; Lentivirus - genetics; Mesenchymal stem cells (MSC); Mesenchymal Stromal Cells - cytology; Mesenchymal Stromal Cells - drug effects; Mesenchymal Stromal Cells - metabolism; Migration; NF kappa B (NFκB); Receptors, Tumor Necrosis Factor - genetics; Reverse Transcriptase Polymerase Chain Reaction; TNF alpha; Transcription Factor RelA - metabolism; Transduction, Genetic; Tumor Necrosis Factor-alpha - pharmacology; IKK-2; TNF alpha; Mesenchymal stem cells (MSC); Migration; Invasion; NF kappa B (NFκB)
• DOI: 10.1016/j.bbrc.2013.05.091
• ISSN: 0006-291X

•HMSC were successfully transduced with a dominant-negative mutant of IκB kinase 2.•Characterization of dnIkk MSC showed unaltered expression of TNFα receptors.•3-D invasion towards the TNFα was significantly reduced after blocking IKK-2.•2-D migration assay revealed a strong migratory response of hMSC towards TNFα.•Blocking of IKK-2 resulted in a significantly increased 2-D migration of hMSC. IκB kinase 2 (IKK-2) mediates tumor necrosis-factor α (TNFα) induced invasion of human mesenchymal stem cell (hMSC) to sites of tissue injury. Suppressing IKK-2 activity leads to reduced expression of proteolytic enzymes and impaired invasive capacity. In order to further reveal mechanisms of hMSC recruitment, we here aimed to analyse the impact of IKK-2 on two-dimensional migration upon TNFα stimulation in contrast to three-dimensional invasion. An immortalized hMSC line (SCP-1) was transduced with a dominant-negative mutant of IκB kinase 2 (SCP-1 dnIKK). Migration was assessed using a linear-gradient chemotaxis chambers by time-lapse analysis. Invasive capacity through human extracellular matrix was analysed using transwell invasion assays. RT-PCR confirmed increased IKK-2 expression levels in SCP-1 dnIKK cells, while TNFα receptor I and II expression was not altered. Invasion upon TNFα stimulation was significantly reduced by 78% in SCP-1 dnIKK. In contrast, migration was significantly increased, represented by a 60% elevated forward migration index and a 2.1-fold higher mean dislocation of the center of mass towards TNFα. In conclusion, our data confirms the impact of IKK-2 in TNFα dependent hMSC recruitment. Interestingly, reducing IKK-2 function increases two-dimensional migration towards TNFα, while invasive capacity is impaired. These findings contribute to a deeper understanding of MSC’s biological properties orchestrating the complex processes of stem cell recruitment and homing.