title: Overexpression of dnIKK in mesenchymal stem cells leads to increased migration and decreased invasion upon TNFα stimulation.
abstract: 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.
authors.affiliation: Experimental Surgery and Regenerative Medicine, Department of Surgery, Ludwig-Maximilians-University Munich, Nussbaumstr. 20, D-80336 Munich, Germany. Florian.Haasters@med.uni-muenchen.de
authors.forename: Florian
authors.initials: F
authors.lastname: Haasters
authors.forename: Wolf Christian
authors.initials: WC
authors.lastname: Prall
authors.forename: Ines
authors.initials: I
authors.lastname: Westphal
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Böcker
authors.forename: Daniela
authors.initials: D
authors.lastname: Padula
authors.forename: Wolf
authors.initials: W
authors.lastname: Mutschler
authors.forename: Denitsa
authors.initials: D
authors.lastname: Docheva
authors.forename: Matthias
authors.initials: M
authors.lastname: Schieker
mesh_terms: D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D002633:Chemotaxis / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D016086:Lentivirus / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051996:Transcription Factor RelA / Q000378:metabolism; D014161:Transduction, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D018124:Receptors, Tumor Necrosis Factor; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D051550:I-kappa B Kinase