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.

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.

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 NFkappaB 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.

Analysis of gene-expression profiles by oligonucleotide microarray in children with influenza.

In order to clarify the mechanism of the host response to influenza virus, gene-expression profiles of peripheral blood obtained from paediatric patients with influenza were investigated by oligonucleotide microarray. In the acute phase of influenza, 200 genes were upregulated and 20 genes were downregulated compared with their expression in the convalescent phase. Interferon-regulated genes, such as interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) and vipirin, were strongly upregulated in the acute phase. Gene ontology analysis showed that immune response genes were highly overrepresented among the upregulated genes. Gene-expression profiles of influenza patients with and without febrile convulsion were also studied. In patients with febrile convulsion, 22 genes were upregulated and five were downregulated compared with their expression in patients without febrile convulsion. These results should help to clarify the pathogenesis of influenza and its neurological complications.

Genetic variation affects de novo translocation frequency.

Translocation is one of the most frequently occurring human chromosomal aberrations. The constitutional t(11;22)(q23;q11), which is the only known recurrent non-Robertsonian translocation, represents a good model for studying translocations in humans. Here we demonstrate polymorphisms of the palindromic sequence at the t(11;22) breakpoint that affect the frequency of de novo translocations in sperm from normal males. A typical allele consists of a perfect palindrome, producing ~10-5 de novo t(11;22) translocations. Alleles with an asymmetric center do not form the t(11;22). Our data show the importance of genome sequence on chromosomal rearrangements, a class of human mutation that is thought to be random.

A microarray-based method for detecting methylated loci.

CpG island DNA methylation plays an important role in regulating gene expression in development and carcinogenesis. We developed a new microarray-based method called methylation amplification DNA chip (MAD) for detecting differences in methylation. In this method, only methylated CpG islands from the two samples that we wanted to compare were amplified and used for hybridization. The resource material for the microarray was derived from the methylated DNA library of the sample in which we wanted to detect hypermethylation. Choosing the methylated DNA library as the resource material of the microarray increased the percentage of DNA fragments derived from hypermethylated loci on the microarray.