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Seiichi Matsuo

Publications and source records attributed to Seiichi Matsuo.

44 records · Page 3Linked to original sources
PubMed2002

Effects of human soluble thrombomodulin on experimental glomerulonephritis.

BACKGROUND: Coagulation and inflammation are both important processes that contribute to glomerular injury. The present study was performed to evaluate the effects of recombinant human soluble thrombomodulin (RHS-TM) in a lethal model of thrombotic glomerulonephritis and to investigate the possible mechanisms. METHODS: Thrombotic glomerulonephritis was induced in rats by administration of lipopolysaccharide and rabbit anti-rat glomerular basement membrane antibody. One hour later, RHS-TM or heparin was administered, and the histological findings, renal functions, and coagulation parameters were evaluated. To evaluate the contribution of carboxypeptidase R (CPR) to the results obtained in rats treated with RHS-TM, plasma CPR levels were measured. Then, carboxypeptidase inhibitor (CPI), which prevents the function of CPR, was administered. RESULTS: Massive glomerular thrombosis and lung hemorrhage developed within five hours of disease induction, and all rats died within 24 hours. RHS-TM (3 mg/kg) prevented the progression of the disease and all rats survived. Heparin (250 U/kg/h) showed similar anti-thrombotic effect, but induced massive hemorrhage in the lungs or stomach. RHS-TM attenuated leukocyte/neutrophil infiltration in the glomerulus but heparin did not, suggesting that RHS-TM has anti-inflammatory properties. CPR levels in plasma were about threefold higher in rats treated with RHS-TM compared to those in rats treated with heparin. Furthermore, the inhibitory effect of RHS-TM on leukocyte/neutrophil infiltration was significantly diminished by injection of CPI. CONCLUSION: RHS-TM effectively attenuates the injuries of thrombotic glomerulonephritis in rats. The results indicate that RHS-TM, in addition to its anti-thrombotic action, may exert its anti-inflammatory properties by converting proCPR to CPR, which then inactivates anaphylatoxins. RHS-TM is a potential novel therapeutic tool for thrombotic glomerular injury and related disorders.

Anaphylatoxins↗
PubMed2002

P-selectin-dependent macrophage migration into the tubulointerstitium in unilateral ureteral obstruction.

BACKGROUND: Interstitial infiltration of macrophages (Mø) is one of the main causal factors for the tubulointerstitial injury. However, precise mechanisms of Mø infiltration into tubulointerstitium have not been fully explored. The purposes of this study were to assess the role of selectins in the acute infiltration of Mø in rats with unilateral ureteral obstruction (UUO) and to evaluate the role of vasa recta, that is, whether they facilitate massive influx of Mø into the interstitium by functioning as specialized vessels. METHODS: To evaluate the role of selectins in Mø infiltration into tubulointerstitium, the expression of selectins and L-selectin ligands was examined by immunohistochemistry and immunoelectron microscopy. The functional role of P-selectin in vasa recta was studied by Stamper-Woodruff assay, in vivo p-Mø migration assay and in vivo blocking experiments with the monoclonal antibody (mAb) ARP2-4. RESULTS: Selective expression of P-selectin was detected in vasa recta as early as one hour after UUO, and the expression increased thereafter for 96 hours. In contrast, endothelial expression of L-selectin ligands and E-selectin were not detectable. In the Stamper-Woodruff assay on kidney sections of rats with UUO, the adhesion of isolated rat peritoneal Mø (p-Mø) to vasa recta was significantly inhibited by the mAb ARP2-4 (P-selectin blocker; P < 0.01), but not by mAb ARE-5 (E-selectin blocker) or rLECIg (rat L-selectin chimeric protein). In the in vivo transfer experiments with fluorescein-labeled p-Mø into rats 48 hours after UUO, labeled p-Mø had accumulated around vasa recta at three minutes and had infiltrated predominantly into the outer medulla at 180 minutes. The number of labeled p-Mø was reduced when the rats were pretreated with ARP2-4 (P < 0.01). Finally, ARP2-4 (10 mg/kg), injected 15 minutes before UUO, reduced the number of infiltrated Mø (P < 0.01). CONCLUSION: The results suggest that vasa recta, which express P-selectin, contribute to massive infiltration of Mø into the interstitium by functioning as specialized post-capillary venules.

Animals↗
PubMed2002

Midkine expression in the course of nephrogenesis and its role in ischaemic reperfusion injury.

Midkine (MK) is a multifunctional heparin-binding growth factor with migration-promoting activity for neutrophils, macrophages and neurones. Since enhanced expression of MK is observed in the tubular epithelial cells of the diseased kidney, it has been suggested that MK plays important roles in the pathogenesis of tubulointerstitial injury. The aim of this study was to determine the contribution of MK in nephrogenesis and in a murine model of ischaemic renal reperfusion injury (IRI). In the 11 day embryo, MK was expressed uniformly in both ureteric bud and metanephrogenic mesenchyme. The immature metanephros expressed both MK mRNA and MK protein more strongly than the mature metanephros. We studied the extent of tubulointerstitial injuries in MK wild-type [Mdk(+/+)] and knockout [Mdk(-/-)] mice 90 min after IRI. MK was expressed weakly in the proximal tubules in Mdk(+/+) mouse kidneys. After IRI, MK expression in proximal tubules increased and the new expression was observed in the distal tubules in Mdk(+/+) mice. Immediate induction of MK expression was observed when cultured tubular epithelial cells (TEpiCs) were exposed to 5 mM H(2)O(2). Recombinant mouse MK (10 ng/ml) induced the increased expression of macrophage inflammatory protein 2 (MIP-2) mRNA in TEpiCs. Shortly after IRI, there were significantly fewer inflammatory leukocytes such as neutrophils and macrophages in Mdk(-/-) mice than in Mdk(+/+) mice. Marked up-regulation of monocyte chemoattractant protein 1 (MCP-1) and MIP-2 expression was detected in Mdk(+/+) mouse kidneys. Tubulointerstitial damage observed after IRI was significantly more suppressed in Mdk(-/-) mice than in Mdk(+/+) mice. These results suggest an important role for MK in the molecular cascade that regulates nephrogenesis. The present work also indicates that MK induces the chemotaxis of inflammatory leukocytes into the tubulointerstitium at least partly through the induction of MCP-1 and MIP-2, and that MK contributes to the aggravation of ischaemia-induced tubulointerstitial damage.

Animals↗
PubMed2002

Risk factors for IgA nephropathy: a case-control study with incident cases in Japan.

BACKGROUND/AIM: Our previous study with prevalent cases suggested that some genetic, immunological and lifestyle-related factors increased the risk of immunoglobulin A nephropathy (IgAN). To confirm this hypothesis, we conducted another case-control study. METHODS: The study included 116 incident cases and 276 sex-, age- and residence-matched controls in central Japan. Information on family and individual history and on lifestyle was collected using a self-administered questionnaire. The strength of association between IgAN and a potential risk factor was assessed by calculating an odds ratio. RESULTS: A family history of chronic glomerulonephritis, susceptibility to the common cold, episodes of tonsillitis in the preceding year, preference for salty foods and a high intake of rice and n-6 polyunsaturated fatty acids (PUFA) were associated with an increased risk of IgAN. Coffee consumption and dietary calcium intake were somewhat negatively related to the risk. A significance of alcohol drinking, use of vitamin supplements, consumption of raw eggs and intake of nutrients other than n-6 PUFA and calcium, though previously suggested, was not shown in the present study. CONCLUSION: Our findings imply that some genetic factors, immune response to infections in the upper respiratory tract and nutritional imbalance would promote the development of IgAN.

Adult↗
PubMed2002

Soluble complement receptor type 1 protects rats from lethal shock induced by anti-Crry antibody following lipopolysaccharide priming.

BACKGROUND: In rats primed with a trace amount of lipopolysaccharide (LPS), acute lethal shock is induced following the injection of monoclonal antibody against a membrane inhibitor of complement (anti-Crry). Administration of cobra venom factor to exhaust complement before the LPS priming can prevent the lethal reaction. Therefore, we evaluated whether soluble complement receptor type 1 (sCR1), which inhibits complement reaction, can interfere with lethal shock when administered after LPS priming or even after anti-Crry injection. METHODS: sCR1 was administered intravenously before or after the administration of anti-Crry, and the effects on blood pressure and acute lethality were determined. RESULTS: Administration of sCR1 could rescue rats from lethal shock even when it was administered after anti-Crry injection, which immediately causes a blood pressure decrease leading to lethal shock. CONCLUSION: sCR1 may be an effective treatment for acute shock involving complement activation.

Animals↗
PubMed2002

[A case of mesangial proliferative glomerulonephritis with endothelial damage].

We describe a 71-year-old man, who had been treated for hypertension, myocardial infarction and abdominal aortic aneurysm, and was admitted to our hospital because of proteinuria(3.9 g/day at the outpatient clinic and 1.5 g/day at the time of admission) and edema in the extremities. Light microscopic study of the kidney biopsy specimen revealed mesangial proliferative glomerulonephritis and glomerular paralysis. Electron microscopic findings showed endothelial damage, including widening of the subendothelial space and detachment of endothelial cells from the glomerular basement membrane. Deposition of immunoglobulins and complement was not detected by immunofluorescence studies. These pathological findings resemble the findings of thrombotic microangiopathy, but there were no clinical pictures of HUS/TTP. These findings suggest that hypertension, atherosclerosis and circulating turbulence caused by an aortic aneurysm induced severe glomerular endothelial damage leading to mesangial proliferative glomerulonephritis without an immune response.

Aged↗
PubMed2000

Complement activation products in the urine from proteinuric patients.

The presence of plasma proteins in the tubular lumen has variety of adverse effects on the tubular cells. Among various plasma proteins filtered through glomerular barrier, complement has been proven as the possible candidate inducing tubulointerstitial injury. To study the role of intratubular complement activation in proteinuric patients, complement activation products (CAP) at C3 level (iC3b and Bb) and C9 level (membrane attack complex) were measured in both plasma and urine of patients with minimal change nephrotic syndrome (MCNS), focal glomerular sclerosis, IgA nephropathy, membranous nephropathy, and diabetic nephropathy. For evaluation of the effect of metabolic acidosis on the intratubular complement activation, urinary CAP were measured before and after sodium bicarbonate administration in patients with renal insufficiency. The following results were obtained: (1) Patients with focal glomerular sclerosis and diabetic nephropathy showed the highest level of urinary CAP excretion rate (unit/creatinine), while MCNS revealed no increase. (2) Patients with membranous nephropathy showed a unique finding, i.e., isolated increase of membrane attack complex excretion. (3) There was no significant correlation between urine and plasma levels of CAP. (4) Except for MCNS patients, the urinary excretion rate of CAP significantly increased when the level of proteinuria exceeded the nephrotic range, and it was significantly correlated with the serum creatinine level. (5) Urinary CAP excretion rate significantly decreased 2 wk after sodium bicarbonate administration without affecting the level of proteinuria or plasma CAP. These results suggest that the degree of intratubular complement activation correlates with the level of proteinuria, type of glomerular disease, impairment of renal function, and metabolic acidosis.

Adolescent↗