Terumi Mori

Serum neutrophil gelatinase-associated lipocalin as a predictor of organ recovery from delayed graft function after kidney transplantation from donors after cardiac death.

Because of a worldwide shortage of renal grafts, kidneys procured from donors after cardiac death (DCD) have recently become an important source of renal transplants. However, DCD kidneys often have complications with delayed graft function (DGF) and recipients require hemodialysis (HD) in the early period after kidney transplantation (KTx). This study evaluated serum NGAL as a potential specific parameter to predict early functional recovery of transplanted DCD kidneys. The average serum neutrophil gelatinase-associated lipocalin (NGAL) level in normal samples was 53 ± 30 ng/ml, while that in patients with chronic renal failure requiring HD was markedly raised at 963 ± 33 ng/ml. In patients undergoing a living-related KTx from a living donor (n = 11), serum NGAL level decreased rapidly after KTx, and only in two cases, with serum NGAL levels over 400 ng/ml on postoperative day 1 (POD1), was HD required due to DGF. In contrast, all patients undergoing a KTx from a DCD (n = 5) required HD due to DGF. Even in these cases, serum NGAL levels decreased rapidly several days after a KTx prior to the recovery of urine output and preceding the decrease in serum creatinine level. The pattern of decline in serum NGAL was biphasic, the decrease after the second peak indicating a functional recovery within the next several days. These data suggest that monitoring of serum NGAL levels may allow us to predict graft recovery and the need for HD after a KTx from a DCD.

Mutations of the SYCP3 Gene in Women with Recurrent Pregnancy Loss

Aneuploidy, a chromosomal numerical abnormality in the conceptus or fetus, occurs in at least 5% of all pregnancies and is the leading cause of early pregnancy loss in humans. Accumulating evidence now suggests that the correct segregation of chromosomes is affected by events occurring in prophase during meiosis I. These events include homologous chromosome pairing, sister-chromatid cohesion, and meiotic recombination. In our current study, we show that mutations in SYCP3, a gene encoding an essential component of the synaptonemal complex that is central to the interaction of homologous chromosomes, are associated with recurrent pregnancy loss. Two out of 26 women with recurrent pregnancy loss of unknown cause were found to carry independent heterozygous nucleotide alterations in this gene, neither of which was present among a group of 150 fertile women. Analysis of transcripts from minigenes harboring each of these two mutations revealed that both affected normal splicing, possibly resulting in the production of C-terminally mutated proteins. The mutant proteins were found to interact with their wild-type counterpart in vitro and inhibit the normal fiber formation of the SYCP3 protein when coexpressed in a heterologous system. These data suggest that these mutations are likely to generate an aberrant synaptonemal complex in a dominant-negative manner and contribute to abnormal chromosomal behavior that might lead to recurrent miscarriage. Combined with the fact that similar mutations have been previously identified in two males with azoospermia, our current data suggest that sexual dimorphism in response to meiotic disruption occurs even in humans.

Increased Urinary Neutrophil Gelatinase Associated Lipocalin Levels in a Rat Model of Upper Urinary Tract Infection

PURPOSE Recurrent upper urinary tract infection is a common complication of vesicoureteral reflux that often leads to irreversible renal scarring. In our previous study of a rat model of renal bacterial infection we performed global gene expression profiling of the kidney during the onset of renal scarring. We have further investigated the product of an up-regulated gene product, NGAL, in this animal model to evaluate its potential usefulness as a biomarker of renal scarring. MATERIALS AND METHODS Renal NGAL mRNA and protein levels were examined by real-time polymerase chain reaction, Western blot and immunohistochemistry. Urinary NGAL levels were monitored by direct enzyme-linked immunosorbent assay. RESULTS Rat renal NGAL mRNA and protein levels were found to be increased soon after bacterial injection. They then decreased rapidly but subsequently persisted at high levels until the 6-week time point after injection. On histological analysis we found that NGAL protein was overproduced in macrophages and renal tubular cells 2 weeks after injection. However, renal tubular cells continued to produce NGAL 6 weeks after injection, whereas this expression was lost in infiltrating cells. Rat urinary NGAL levels were also markedly increased at the early stages of infection and they persisted at high levels throughout the latter stages of the experiment. CONCLUSIONS Urinary NGAL may be a potential noninvasive diagnostic biomarker of renal scarring.

Genomewide expression profiles of rat model renal isografts from brain dead donors

Background. It has been well documented that two factors, brain death (BD) and ischemia/reperfusion (I/R) injury, have distinct but overlapping adverse influences on the clinical outcome of renal transplantation. Method. We previously established a rat model of renal isografting from brain dead donors. In the present study, we performed genomic expression profiling with a high-density oligonucleotide microarray to identify genes that were upregulated or downregulated by BD and/or I/R injury. Results. Among a total of 20,550 genes, most of those upregulated by BD were genes for adhesion molecules and cytokines or for chemokines such as Gro1 and IP-10. When overexpression of these genes was assessed by real-time reverse transcriptase–polymerase chain reaction, it was only observed one hr after the engraftment of kidneys from BD donors and returned to baseline thereafter, indicating the presence of an acute systemic inflammatory response to BD. Analysis of biologic networks demonstrated the activation of specific pathways that were clearly different for BD and I/R injury. The p53 and NF&kgr;B pathway was involved in the acute response to BD, whereas the Myc, Jun, and c-fos pathway was involved in I/R injury. Investigation of secretory protein genes identified LCN2 and SPP1 as candidate genes for biologic markers. Conclusion. Because our experimental system is a good model of renal transplantation from brain dead or living human donors, our data may be useful for elucidating the pathologic processes involved and for identification of novel markers for graft dysfunction of renal transplantation.

Urinary Neutrophil-Gelatinase Associated Lipocalin is a Potential Noninvasive Marker for Renal Scarring in Patients With Vesicoureteral Reflux

PURPOSE Renal scarring is a serious complication that often occurs with chronic pyelonephritis in the presence of vesicoureteral reflux. In a previous study we established a rat model of renal scarring in which we found the up-regulation of neutrophil-gelatinase associated lipocalin at the mRNA and protein levels. In this study we evaluated urinary neutrophil-gelatinase associated lipocalin as a potential biomarker for progression of renal scarring in patients with vesicoureteral reflux. MATERIALS AND METHODS A total of 34 patients diagnosed with vesicoureteral reflux without evidence of current urinary tract infection and 28 normal healthy children were enrolled in this study. Renal scars were evaluated by (99m)technetium dimercapto-succinic acid renal scan in 24 of the reflux cases. Urinary neutrophil-gelatinase associated lipocalin levels were monitored by ELISA. RESULTS In normal subjects urinary neutrophil-gelatinase associated lipocalin was high during infancy, decreased rapidly within the following year and reached a low stable level from age 3 years onward. Urinary neutrophil-gelatinase associated lipocalin levels, normalized to age matched standards, were significantly increased in patients with vesicoureteral reflux compared to controls. These levels did not correlate with reflux grade, but were significantly higher in patients with radiological evidence of renal scarring irrespective of reflux grade. CONCLUSIONS Estimation of urinary neutrophil-gelatinase associated lipocalin may be useful as a noninvasive diagnostic or prognostic biomarker for renal scarring.

Global expression profiles in 1-hour biopsy specimens of human kidney transplantation from donors after cardiac death.

Because of the worldwide shortage of renal grafts, kidney transplantation (KTx) from donors after cardiac death (DCD) is an alternative way to obtain KTx from brain-dead donors. Although the prognosis of DCD KTx is gradually improving, the graft often undergoes delayed graft function (DGF), rendering the control of DGF essential for post-KTx patient care. In an attempt to characterize etiology of DGF, genome-wide gene expression profiling was performed using renal biopsy samples performed at 1 h after KTx from DCD and the data were compared with those of KTx from living donors (LD). A total of 526 genes were differentially expressed between them. Genes involved in acute inflammation were activated, while metabolic pathways were consistently downregulated in DCD. These findings imply the inferior performance of the DCD grafts relative to LD grafts. Several genes were identified where the expression levels were correlated well with parameters indicating short- and long-term prognosis of the DCD patients. In addition, several genes encoding secretory proteins were identified that might reflect the performance of the graft and be potential noninvasive biomarkers. These data provide a good source for candidates of biomarkers that are potentially useful for the control of DGF.

A functional variation in the hypocretin neuropeptide precursor gene may be associated with obstructive sleep apnea syndrome in Japan

To evaluate the association of hypocretin neuropeptide precursor gene (HCRT) variations with obstructive sleep apnea syndrome (OSAS) in a cohort of Japanese patients and to further evaluate whether the significant HCRT variations have potential functional consequences on HCRT expression.