Evaluation of CXCL9 and CXCL10 as circulating biomarkers of human cardiac allograft rejection

BACKGROUND: Cardiac allograft rejection remains a significant clinical problem in the early phase after heart transplantation and requires frequent surveillance with endomyocardial biopsy. However, this is an invasive procedure, which is unpleasant for the patient and carries a certain risk. Therefore, a sensitive non-invasive biomarker of acute rejection would be desirable. METHODS: Endomyocardial tissue samples and serum were obtained in connection with clinical biopsies from twenty consecutive heart transplant patients followed for six months. A rejection episode was observed in 14 patients (11 men and 3 women) and biopsies obtained before, during and after the episode were identified. Endomyocardial RNA, from three patients, matching these three points in time were analysed with DNA microarray. Genes showing up-regulation during rejection followed by normalization after the rejection episode were evaluated further with real-time RT-PCR. Finally, ELISA was performed to investigate whether change in gene-regulation during graft rejection was reflected in altered concentrations of the encoded protein in serum. RESULTS: Three potential cardiac allograft rejection biomarker genes, chemokine (C-X-C motif) ligand 9 (CXCL9), chemokine (C-X-C motif) ligand 10 (CXCL10) and Natriuretic peptide precursor A (NPPA), from the DNA microarray analysis were selected for further evaluation. CXCL9 was significantly upregulated during rejection (p < 0.05) and CXCL10 displayed a similar pattern without reaching statistical significance. Serum levels of CXCL9 and CXCL10 were measured by ELISA in samples from 10 patients before, during and after cardiac rejection. There were no changes in CXCL9 and CXCL10 serum concentrations during cardiac rejection. Both chemokines displayed large individual variations in the selected samples, but the serum levels between the two chemokines correlated (p < 0.001). CONCLUSION: We conclude, that despite a distinct up-regulation of CXCL9 mRNA in human hearts during cardiac allograft rejection, this was not reflected in the serum levels of the encoded protein. Thus, in contrast to previous suggestions, serum CXCL9 does not appear to be a promising serum biomarker for cardiac allograft rejection

Hypoxia-Induced Mitogenic Factor (HIMF/FIZZ1/RELMα) Recruits Bone Marrow-Derived Cells to the Murine Pulmonary Vasculature

. and localized to the media layer of the vessels. This finding suggests that these cells are of mesenchymal origin and differentiate toward myofibroblast and vascular smooth muscle. Structural location in the media of small vessels suggests a functional role in the lung vasculature. To examine a potential mechanism for HIMF-dependent recruitment of mesenchymal stem cells to the pulmonary vasculature, we performed a cell migration assay using cultured human mesenchymal stem cells (HMSCs). The addition of recombinant HIMF induced migration of HMSCs in a phosphoinosotide-3-kinase-dependent manner.These results demonstrate HIMF-dependent recruitment of BMD mesenchymal-like cells to the remodeling pulmonary vasculature

STAT-1 decoy oligodeoxynucleotide inhibition of acute rejection in mouse heart transplants

During acute rejection of cardiac transplants endothelial cell–leukocyte interaction fuelled by co-stimulatory molecules like CD40/CD154 may ultimately lead to graft loss. One key player in up-regulating the expression of such pro-inflammatory gene products is the interferon-γ-dependent transcription factor STAT-1. Hence down-regulating interferon-γ-stimulated pro-inflammatory gene expression in the graft endothelial cells by employing a decoy oligodeoxynucleotide (dODN) neutralising STAT-1 may protect the graft. To verify this hypothesis, heterotopic mouse heart transplantation was performed in the allogeneic B10.A(2R) to C57BL/6 and syngeneic C57BL/6 to C57BL/6 strain combination without immunosuppression. Graft vessels were pre-treated with STAT-1 dODN, mutant control ODN (10 μM each) or vehicle (Ringer solution). Cellular rejection (vascular and interstitial component) was graded histologically and CD40, ICAM-1, VCAM-1, MCP-1, E-selectin and RANTES expression in the graft monitored by real time PCR 24 h and 9 days post-transplantation. Nine days after transplantation both rejection scores were significantly diminished by 85 and 70%, respectively, in STAT-1 dODN-treated allografts as compared to mutant control ODN-treated allografts. According to immunohistochemistry analysis, this was accompanied by a reduced infiltration of monocyte/macrophages and T cells into the graft myocardium. In addition, pro-inflammatory gene expression was strongly impaired by more than 80% in STAT-1 dODN-treated allografts 24 h post-transplantation but not in mutant control ODN or vehicle-treated allografts. This inhibitory effect on pro-inflammatory gene expression was no longer detectable 9 days post-transplantation. Single periprocedural treatment with a STAT-1 dODN thus effectively reduces cellular rejection in mouse heart allografts. This effect is associated both with an early decline in pro-inflammatory gene expression and a later drop in mononuclear cell infiltration

Heart Valve Tissue Engineering: Concepts, Approaches, Progress, and Challenges

Potential applications of tissue engineering in regenerative medicine range from structural tissues to organs with complex function. This review focuses on the engineering of heart valve tissue, a goal which involves a unique combination of biological, engineering, and technological hurdles. We emphasize basic concepts, approaches and methods, progress made, and remaining challenges. To provide a framework for understanding the enabling scientific principles, we first examine the elements and features of normal heart valve functional structure, biomechanics, development, maturation, remodeling, and response to injury. Following a discussion of the fundamental principles of tissue engineering applicable to heart valves, we examine three approaches to achieving the goal of an engineered tissue heart valve: (1) cell seeding of biodegradable synthetic scaffolds, (2) cell seeding of processed tissue scaffolds, and (3) in-vivo repopulation by circulating endogenous cells of implanted substrates without prior in-vitro cell seeding. Lastly, we analyze challenges to the field and suggest future directions for both preclinical and translational (clinical) studies that will be needed to address key regulatory issues for safety and efficacy of the application of tissue engineering and regenerative approaches to heart valves. Although modest progress has been made toward the goal of a clinically useful tissue engineered heart valve, further success and ultimate human benefit will be dependent upon advances in biodegradable polymers and other scaffolds, cellular manipulation, strategies for rebuilding the extracellular matrix, and techniques to characterize and potentially non-invasively assess the speed and quality of tissue healing and remodeling

Liver transection using the LigaSure sealing system

Background. The aim of the present study was to evaluate the feasibility and efficacy of the LigaSure vessel sealing system on a large scale when used for liver resection. Methods. We retrospectively analyzed the short-term outcomes of 277 patients undergoing hepatectomies with the use of the LigaSureR system. Results. There were two hospital deaths (0.7%), and the morbidity rate was 25.3%. Mean blood loss during liver transection was 352±422 ml, and the liver transection speed was 1.9±0.86 cm2/min. The number of ties required during liver transection was 13.2±13. The morbidity and mortality rate was similar when comparing patients with injured livers (chronic hepatitis or cirrhosis) and those with normal livers, but liver transection speed was faster in those with normal livers when compared with those with injured livers (2.00±0.88 vs. 1.57±0.63 cm2/min, p=0.001). Conclusions. The LigaSure system can be applied safely in patients undergoing liver resection, regardless of whether cirrhosis is present or not