Adiponectin and ischemia-reperfusion injury in ST segment elevation myocardial infarction.

BACKGROUND: Models of experimental ischemia-reperfusion (IR) in adiponectin knockout animals have shown that adiponectin mediates protection against the development of IR injury. However, the role of adiponectin in IR injury in humans is largely unknown. METHODS: In a total of 234 ST segment elevation myocardial infarction (STEMI) patients, baseline circulating total adiponectin concentration was correlated with IR injury after primary percutaneous coronary intervention (pPCI) and with major adverse cardiac events (MACE, death and cardiac hospitalization) during one year of follow up. IR injury was defined by serial electrocardiography (ECG) as >30% persistent ST segment elevation despite successful restoration of vessel patency and by angiography as thrombolysis in myocardial infarction (TIMI) blush grade<2. RESULTS: IR injury was present in 31% of patients according to ECG criteria and in 28% of patients according to angiographic criteria. The median adiponectin level was 6.8 µg/ml in patients with ECG signs of IR injury and 6.5 µg/ml in patients without ECG signs of IR (p=0.26). When the angiographic criteria of IR were used, the median adiponectin level was 6.9 µg/ml for patients with IR versus 6.3 µg/ml for patients without IR (p=0.06). MACE occurred in 27% of the patients. Median adiponectin levels were similar in patients with MACE and in those without MACE: 6.3 vs. 6.4 µg/ml (p=0.24). In a multivariate model, no significant relation between circulating adiponectin levels and IR injury or MACE was evident. CONCLUSION: In the current era of pPCI, IR injury still occurs in almost one third of STEMI patients. Our findings do not support a major protective role of adiponectin in the prevention or attenuation of IR injury in these patients.

Plasmid-based genetic modification of human bone marrow-derived stromal cells: analysis of cell survival and transgene expression after transplantation in rat spinal cord.

BACKGROUND: Bone marrow-derived stromal cells (MSC) are attractive targets for ex vivo cell and gene therapy. In this context, we investigated the feasibility of a plasmid-based strategy for genetic modification of human (h)MSC with enhanced green fluorescent protein (EGFP) and neurotrophin (NT)3. Three genetically modified hMSC lines (EGFP, NT3, NT3-EGFP) were established and used to study cell survival and transgene expression following transplantation in rat spinal cord. RESULTS: First, we demonstrate long-term survival of transplanted hMSC-EGFP cells in rat spinal cord under, but not without, appropriate immune suppression. Next, we examined the stability of EGFP or NT3 transgene expression following transplantation of hMSC-EGFP, hMSC-NT3 and hMSC-NT3-EGFP in rat spinal cord. While in vivo EGFP mRNA and protein expression by transplanted hMSC-EGFP cells was readily detectable at different time points post-transplantation, in vivo NT3 mRNA expression by hMSC-NT3 cells and in vivo EGFP protein expression by hMSC-NT3-EGFP cells was, respectively, undetectable or declined rapidly between day 1 and 7 post-transplantation. Further investigation revealed that the observed in vivo decline of EGFP protein expression by hMSC-NT3-EGFP cells: (i) was associated with a decrease in transgenic NT3-EGFP mRNA expression as suggested following laser capture micro-dissection analysis of hMSC-NT3-EGFP cell transplants at day 1 and day 7 post-transplantation, (ii) did not occur when hMSC-NT3-EGFP cells were transplanted subcutaneously, and (iii) was reversed upon re-establishment of hMSC-NT3-EGFP cell cultures at 2 weeks post-transplantation. Finally, because we observed a slowly progressing tumour growth following transplantation of all our hMSC cell transplants, we here demonstrate that omitting immune suppressive therapy is sufficient to prevent further tumour growth and to eradicate malignant xenogeneic cell transplants. CONCLUSION: In this study, we demonstrate that genetically modified hMSC lines can survive in healthy rat spinal cord over at least 3 weeks by using adequate immune suppression and can serve as vehicles for transgene expression. However, before genetically modified hMSC can potentially be used in a clinical setting to treat spinal cord injuries, more research on standardisation of hMSC culture and genetic modification needs to be done in order to prevent tumour formation and transgene silencing in vivo.