y Medical Centre. Animal e perimentation was approved by the local committee for care and use of laboratory animals and performed according to strict governmental and international guidelines. The investigation conformed to Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health. HL 1 murine cardiomyocytes were a kind gift of Dr. William C. Claycomb. Cells were main tained in fibronectin coated flasks in Claycomb e pansion medium supplemented with 10% FBS, 0. 1 mM norepin ephrine, 100 U mL penicil lin, 100 mg mL streptomycin and 2mM L glutamine and kept semi confluent at all times. E perimental culture conditions Prior to co cultures of ADSC and rat neonatal car diomyocytes the cells were labeled with the CFDA SE and CM DiI respectively according to the manufacturer s instructions.

Co cultures of ADSC and HL 1 cardiomyocytes were Dacomitinib done after lentivirus tagging with resp. lentiviruses encoding eGFP and dTomato. Briefly, on the day of transduction, cells were plated at 1�� 106 cells well in serum free growth medium containing 5 ug ml polybrene . Following overnight incubation, medium was replaced with normal growth medium containing 10% FBS. The medium of HL 1 cells was changed once per 24h while ADSC medium was replenished three times a week. At five days post transduction, cells were FACS sorted based on e pression of eGFP or dTOMATO to obtain pure cell population. To determine the influence of the ADSC density on cardiomyocyte proliferation, ADSC were treated with 10 ug ml mitomycin C for 3h, followed by e tensive washing with PBS prior the co culture with rnCM and HL 1 cells.

The ADSC cell ratios plated in co culture conditions varied from 1 1 to 1 3 for rnCM, while keeping the rnCM at 20,000 cells cm2. The ADSC ratios in co cultures with HL 1 cells varied from 1 1 to 1 4, while keeping the HL 1 cells at 6,000 cells cm2. Simultaneously, cells were labeled with 1 uM BrdUrd bromodeo yuridine for 6h at the end of the e periment. In order to study the effect of the post MI microenvironment on cardiomyocytes, rnCM and HL 1 cells and ADSC were cultured at ambient o ygen tension 21% O2 or at 2% O2. At these o ygen tensions inflamma tion was mimicked by continuous treatment with TNF or IL 1B or none as a control for 24 and 48h respectively. ADSC conditioned medium was collected after pre treatment according to the e perimental procedures for 24h.

Subse quently, followed by medium replacement without the stimuli and conditioning in 0% FBS Claycomb Medium for 24h. Gene transcript analysis ADSC were seeded in 12 well plates at 10,000 cells cm2 in DMEM and treated according to the e perimental procedures. HL 1 cardiomyocytes were seeded in 12 well plates at 10,000 cells cm2 in 5% FBS Claycomb medium, afterwards cells were incubated with 10% FBS and 0% FBS Claycomb medium or 0% FBS ADSC conditioned medium for 24h and treated according to the e perimental procedures. Cells were harvested at the pre determined time poi