We identified the inv gene that encodes left and right asymmetry and regulates kidney development based on the information of the inv mutant mouse. However, functional properties and the modulator of gene expression of inv have been unclear. We used the tissue injury model for assessing the functional roles of inv in ischemia reperfusion injury (IRI). The kidney tissue taken from rats with IRI showed reciprocal changes in mRNA expression of inv: a 0.25-fold decrease at 6 hours and then a gradual increase to a maximum 1.8-fold rise at 10 days of reperfusion. Next, oxidative stress was induced by exposing mouse inner medullary collecting duct (mIMCD-3) cells to hydrogen peroxide (H₂O₂) in the medium. Real-time PCR showed that mRNA expression of inv decreased 0.52-fold at 3 hours with 0.2mM H₂O₂ in the medium, and then increased 3.1-fold at 24 hours with 0.1mM H₂O₂ in the medium.
RNA interference (RNAi) is a powerful tool to inhibit gene expression in experimental model systems. We knocked down inv gene expression in mIMCD-3 cells using RNAi to investigate the function of the inv gene. We designed a small interfering RNA (siRNA) to target the coding region of inv (inv-siRNA) and random-sequence scrambled siRNA (control siRNA). mIMCD-3 cells transfected with either the inv-siRNA or control siRNA were observed by microscopy. The cells transfected with inv-siRNA progressively lost cell-to-cell contact and the cell population significantly diminished approximately 48 hours post-transfection. The changes in gene expression profile were observed at time points (36 hours) using real-time PCR-based gene screening with categorized primer sets. Several genes related to structural protein of the matrix were downregulated. In contrast, repairing related genes were upregulated.
In conclusion, gene expression of inv was modulated under oxidative stress and the inv gene may play a role in repairing and regenerating renal epithelial cells.

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The role of androgens in the production of 20-hydroxyeicosatetraenoic acid (20-HETE) was determined in the kidney of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The renal production of 20-HETE and blood pressure were higher in males than in females at 9 weeks of age. The renal production of 20-HETE was significantly greater in male SHR than in male WKY, whereas it was significantly lower in female SHR than in female WKY. The differences in the renal production of 20-HETE were consistent with the cytochrome P-450 4A protein levels. Plasma free-testosterone levels in male SHR were twice as high as those in male WKY. Castration and treatment with the androgen receptor antagonist, flutamide, reduced blood pressure, the renal production of 20-HETE, and P-450 4A protein levels in both strains. The renal production of 20-HETE was significantly lower in castrated SHR than in castrated WKY. These results indicate that the renal production of 20-HETE and the expression of P-450 4A have gender and strain-differences, and high levels of plasma androgens induce the expression of P-450 4A and the production of 20-HETE in the kidney of male SHR. The androgen-induced production of 20-HETE may be associated with hypertension in male SHR.

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It is reported that urinary ATP concentration analysis is useful for determining urinary tract infection and renal damage caused by drugs. By means of the firefly luciferin-luciferase method, we determined the reference value of urinary free ATP and evaluated the effects of urine sediments and conditions of storage. The reference value was established as 1.77×10^-10-7.70×10^-9M using urine samples obtained from 63 outpatients who seemed to have no renal disease. There was no significant difference in ATP oncentration between 33 males and 30 females. No significant changes were observed in 11 healthy volunteers during a 1-year period. Within-run reproducibility of ATP was satisfying (8.28% and 11.4% of coefficient value in low and high concentration samples, respectively). ATP concentration was significantly decreased after centrifugation (p<0.05) and after filtration (p<0.01). The amounts of the red blood cells (RBC) and white blood cells (WBC) in samples whose ATP concentration was decreased after centrifugation or filtration were significantly higher than those in samples whose concentration did not decrease (p<0.05). Urine containing many RBCs and/or WBCs might show an artificially higher ATP concentration if no preparations has been performed. There were significant positive correlations between the ATP concentrations before and after refrigeration, but no correlations before and after freezing.
It is concluded that the reference value of urinary free ATP concentration was 1.77×10^-10-7.70×10^-9M and that care is required in the estimation of urinary ATP concentrations in samples containing many sediments, especially with WBC and RBC.

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Dialysis patients are weak in immune host defense, which is associated with their high morbidity of infection. Polymorphonuclear leukocytes (PMNLs) and mononuclear cells play a key role in innate host defense. PMNLs and monocytes have bactericidal activity through the process of phagocytosis. Monocytes and lymphocytes contribute to the development of innate immunity by their cytokine actions. We studied the intracellular cytokine syntheses in response to ex-vivo stimuli, which may reflect the potential reactivity of immune cells in cytokine syntheses when pathogens invade humans. Furthermore, phagocytic activity was assessed in granulocytes and monocytes. Twenty HD, 15 CAPD, and 10 age-matched controls were enrolled in this study. One milliliter of whole blood from each subject was incubated with lipopolysaccharides (LPS) or mitogens for 4 hours at 3T°C. Monoclonal antibodies to CD14⁺ and CD4⁺ were used for identifying monocytes and helper T cells, respectively. Intracellular cytokines were stained using FASTIMMUNE^® staining kits. Interleukin-1β and TNF-α syntheses were examined in monocytes, which are the most important early-response cytokines in innate immunity. IFN-γ and IL-4 syntheses were examined in helper T cells to observe their polarization into Th1 and Th2 cells. IFN-γ is a key factor in establishing innate immunity. The percentage of cells that stained positive for each cytokine was analyzed using a flow cytometer.
The following results were obtained: 1) In CAPD patients, IL-1β and TNF-α response to LPS in monocytes were significantly reduced, as compared to other subjects. Polarization of helper T cells was reduced, resulting in a significant decrease in Th1 cells. 2) In HD patients, monokine responses were not altered, but polarization of helper T cells was skewed toward a Th1 type. Phagocytic activities were not impaired in both dialysis groups. In conclusion, mononuclear cells from CAPD patients have the potential to exhibit failure of a cytokine response to ex-vivo stimuli in terms of innate immunity.

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A 48-year-old woman with systemic sclerosis (SSc) and rheumatoid arthritis was admitted to ourhospital because of renal dysfunction. She had no hypertension at the time of admission and mild hypertension for only one and a half months until the time of admission. After admission, she received angiotensin-converting enzyme-inhibitor, but her renal dysfunction did not improve. She then had thrombotic microangiopathy with thrombocytopenia, and was treated with plasma exchange five times, but her renal dysfunction persisted. The renal biopsy specimens showed an arteriosclerotic lesion with intimal thickening and luminal narrowing and ischemic glomerular changes. These findings suggest that there is chronic vascular injury in a patient who has no hypertension with SSc and that once hypertension supervenes, whether severe or not, exacerbation of the vascular injury and renal dysfunction may occur.

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A 68-year-old woman was admitted to our hospital because of severe oliguria and macrohematuria. She was diagnosed as postrenal acute renal failure, because of bilateral dilatation of the renal pelvis on abdominal computed tomography (CT). Percutaneous nephrostomy was performed after hemodialysis was initiated. Next, urinary volume and serum creatinine level were normalized. Percutaneous biopsy towards the mass in the peritoneal cavity under abdominal CT revealed adenocarcinoma, although the primary site of the carcinoma could not be identified. Autopsy was permitted after her sudden death. It revealed that the primary carcinoma was a right pelvic and ureteral tumor. The right pelvic and ureteral tumor was composed of a mixture of transitional cell carcinoma and adenocarcinoma.

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Autosomal dominant polycystic kidney disease (ADPKD) is rarely observed in the neonatal period. We report 2 cases of ADPKD who showed bilateral enlarged, hyperechoic kidneys and severe hypertension. It is difficult to differentiate ADPKD from autosomal recessive polycystic kidney disease (ARPKD) based on the initial clinical presentations in this period. In both cases, bilateral enlarged kidneys and severe hypertension were detected without oligohydramnion and respiratory distress. The mother of case 1 has polycystic kidneys. The father of case 2 was diagnosed as ADPKD. Case 2 had heart failure due to hypertension. Angiotensin converting enzyme inhibitor (ACE-I) was administered to both patients and resulted in good control of blood pressure. ADPKD in the neonatal and very early infantile period has diverse clinical courses. In general, although severe cases are rare, some cases have renal failure and/or hypertension as we reported.
We emphasize that both the prompt diagnosis of ADPKD and the start of medication are of great importance in the neonatal and very early infantile period. We recommend that neonates and infants with a family history of ADPKD undergo screening including physical examinations, blood pressure measurements and urinalysis.

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