Delayed graft function (DGF), especially long-lasting DGF, complicates kidney transplant outcome. Neutrophil gelatinase-associated lipocalin (NGAL) is an acute kidney injury marker; therefore, we tested whether urine NGAL could predict DGF, prolonged DGF (lasting over 14 days), or the quality of kidney function in transplant recipients without DGF (non-DGF). We collected urine samples from 176 recipients transplanted with deceased donor kidneys before and various days after transplantation. A total of 70 transplantations had DGF, of which 26 were prolonged. Patients who developed DGF had a significantly slower decrease in urinary NGAL compared with those without DGF, such that day 1 NGAL predicted DGF (area under the curve (AUC) 0.75) and predicted DGF in 15 of 112 cases with day 1 urine output over 1 l (AUC 0.70) and in 19 of 86 cases with a day 1 decrease in creatinine over 50 μmol/l (AUC 0.74). The urinary NGAL level on day 1 predicted prolonged DGF (AUC 0.75), which had significantly worse 1-year graft survival (73%), compared with shorter DGF (100%). In non-DGF, high day 3 NGAL (greater than the mean) was associated with significantly worse kidney function at 3 weeks compared with low NGAL, but not at 3 months and 1 year. NGAL did not correlate with long-term function in DGF. Hence, day 1 urinary NGAL predicted DGF even when it was not clinically expected early on, and importantly, it predicted prolonged DGF that led to worse graft survival.

Connective tissue growth factor (CTGF) is a polypeptide implicated in the extracellular matrix synthesis.Previous studies have provided evidence that angiotensin II (Ang II) promotes collagen synthesis and regulates collagen degradation. We investigated whether or not CTGF mediates the profibrotic effects of Ang II in the heart and kidneys and the role of calcineurin-dependent pathways in CTGF gene regulation. In transgenic rats harboring human renin and angiotensinogen genes, Ang II induced an age-dependent increase in myocardial CTGF expression, which was 3.5-fold greater compared to normotensive Sprague Dawley (SD) rats. CTGF overexpression correlated closely with the Ang II-induced rise in blood pressure. CTGF mRNA and protein were located predominantly in areas with leukocyte infiltration, myocardial, and vascular lesions and co-localized with TGF␤ 1 , collagen I, and collagen III mRNA expressions. Ang II induced CTGF mRNA and protein to a lesser extent in the kidneys, predominantly in glomeruli, arterioles, and in the interstitium with ample inflammation. However, no expression was found in the right ventricle or pulmonary arteries. Blockade of calcineurin activity by cyclosporine A completely normalized Ang II-induced CTGF overexpression in heart and kidney, suppressed the inflammatory response, and mitigated Ang II-induced cell proliferation and apoptosis. In contrast, blockade of mTOR (target of rapamycin) pathway by everolimus, further increased the expression of CTGF even though everolimus ameliorated cell proliferation and T-cellmediated inflammation. Our findings provide evidence that CTGF mediates Ang II-induced fibrosis in the heart and kidneys via blood pressure and cal-

The restoration of functional connective tissue is a major goal of the wound healing process. The 72- and 92-kD gelatinases (MMP-2 and MMP-9) are extracellular matrix metalloproteinases (MMPs), which are known to degrade type IV and V collagens and gelatin, and have a potential role in wound healing. The spatial and temporal gelatinolytic activities of MMP-2 and MMP-9 were analyzed as a function of ulcer age, in homogenates of rat, indomethacin-induced, chronic gastric ulcers. The rats were sacrificed on 1, 3, 7, 12, 18, 24 and 28 days after subcutaneous indomethacin injections. Zymographic analyses revealed elevated activation of MMP-9 and latent and active MMP-2 in gastric ulcers, when compared to gastric tissue from non-indomethacin-treated rats. The intact tissue and tissue from ulcerous lesions contained MMP-2. The highest activity of MMP-2 was found in 3 day gastric ulcers and returned to the control level by day 24. MMP-9 was not present in the intact tissue and the highest gelatinolytic activity of MMP-9 was also observed on the 3rd day after administration of indomethacin. The activity thereafter decreased and returned to the control level by day 24. In situ hybridization was used to evaluate which cells synthesize MMP-2 and MMP-9. MMP-2 was seen mostly in fibroblast-like cells in the submucosa and MMP-9 in macrophage-like cells in the mucosa on the margins of the ulcers. Thus, we conclude that these two MMPs seem to have different functions during the gastric ulcer injury/healing process. MMP-2 may participate in the physiological turnover of the gastric extracellular matrix, whereas MMP-9 may be important in the early phase of gastric ulcer formation and also in the healing process.

IntroductionExpanding the criteria for deceased organ donors increases the risk of delayed graft function (DGF) and complicates kidney transplant outcome. We studied whether donor neutrophil gelatinase-associated lipocalin (NGAL), a novel biomarker for acute kidney injury, could predict DGF after transplantation.MethodsWe included 99 consecutive, deceased donors and their 176 kidney recipients. For NGAL detection, donor serum and urine samples were collected before the donor operation. The samples were analyzed using a commercial enzyme-linked immunosorbent assay kit (serum) and the ARCHITECT method (urine).ResultsMean donor serum NGAL (S-NGAL) concentration was 218 ng/mL (range 27 to 658, standard deviation (SD) 145.1) and mean donor urine NGAL (U-NGAL) concentration was 18 ng/mL (range 0 to 177, SD 27.1). Donor S-NGAL and U-NGAL concentrations correlated directly with donor plasma creatinine levels and indirectly with estimated glomerular filtration rate (eGFR) calculated using the modification of diet in renal disease equation for glomerular filtration rate. In transplantations with high (greater than the mean) donor U-NGAL concentrations, prolonged DGF lasting longer than 14 days occurred more often than in transplantations with low (less than the mean) U-NGAL concentration (23% vs. 11%, P = 0.028), and 1-year graft survival was worse (90.3% vs. 97.4%, P = 0.048). High U-NGAL concentration was also associated with significantly more histological changes in the donor kidney biopsies than the low U-NGAL concentration. In a multivariate analysis, U-NGAL, expanded criteria donor status and eGFR emerged as independent risk factors for prolonged DGF. U-NGAL concentration failed to predict DGF on the basis of receiver operating characteristic curve analysis.ConclusionsThis first report on S-NGAL and U-NGAL levels in deceased donors shows that donor U-NGAL, but not donor S-NGAL, measurements give added value when evaluating the suitability of a potential deceased kidney donor.

The restoration of functional connective tissue is a major goal of the wound healing process which is probably affected by matrix-modifying enzymes. To evaluate the spatial and temporal expression of matrix metalloproteinases (MMP) MMP-2 and MMP-9 and to study the regulation of MMP-2 in wound healing, subcutaneously implanted viscose cellulose sponges in rats were used to induce granulation tissue formation for up to 3 months. MMP-2 mRNA expression was seen throughout the experiment and it was highest after 2 months. MMP-9 gene expression was low between days 8-21 and increased after 4 weeks of granulation tissue formation. Membrane-type 1 MMP (MT1-MMP) mRNA was upregulated early and tissue inhibitor 2 of MMP (TIMP-2) mRNA later during wound healing. In in situ hybridization the expression of MMP-2 mRNA was seen mostly in fibroblast-like cells and MMP-9 mRNA in macrophage-like cells. MMP-9 immunoreactivity was detected in the polymorphonuclear leukocytes and macrophage-like cells on days 3-8. MMP-9 proteolytic activity was observed only on days 3-8. The active form of the MMP-2 increased up to day 14, whereafter it remained at a constant level, whereas latent MMP-2 did not show any apparent changes during the experimental period. We conclude that MMP-2 is important during the prolonged remodelling phase, whereas the gelatinolytic activity of MMP-9 was demonstrated only in early wound healing, and the MMP-9 gene is upregulated when the granulation tissue matures.

Summary The temporal activity and gene expression of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinase (TIMP) were investigated in a rat model of chronic allograft nephropathy. Gelatinolytic activity of MMP‐2 and ‐9 were demonstrated by zymography, and MMP‐2,‐9 and TIMP‐3 mRNA by in situ hybridization. The generation of fibrosis was determined as total collagen content/DNA. Significantly more latent and active MMP‐2, as well as latent MMP‐9, were seen in allografts than in autografts. Intense MMP‐2 mRNA expression was demonstrated in the allografts during the first 20 days after transplantation, located mainly in the interstitium of the kidney. In addition, some tubular cells expressed MMP‐2 mRNA. After day 20, MMP‐2 gene expression was faint. MMP‐9 mRNA expression in allografts was located mainly in the glomerulus. TIMP‐3 mRNA expression was downregulated in allografts. MMP‐2, MMP‐9 and TIMP‐3 seem to play a critical role in the development of fibrosis in the renal allograft.

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CsA increases CTGF, collagen I, and collagen III mRNA expressions in the heart. The induction of CTGF gene is mediated, at least in part, by angiotensin II.