An inhibitor of Krüppel-like factor 5 suppresses peritoneal fibrosis in mice.

BACK GROUND: Krüppel-like transcription factor 5 (KLF5) is a transcription factor regulating cell proliferation, angiogenesis and differentiation. It has been recently reported that Am80, a synthetic retinoic acid receptor α-specific agonist, inhibits the expression of KLF5. In the present study, we have examined the expression of KLF5 in fibrotic peritoneum induced by chlorhexidine gluconate (CG) in mouse and evaluated that Am80, as an inhibitor of KLF5, can reduce peritoneal fibrosis. METHODS: Peritoneal fibrosis was induced by intraperitoneal injection of CG into peritoneal cavity of ICR mice. Am80 was administered orally for every day from the start of CG injection. Control mice received only a vehicle (0.5% carboxymethylcellulose solution). After 3 weeks of treatment, peritoneal equilibration test (PET) was performed and peritoneal tissues were examined by immunohistochemistry. RESULTS: The expression of KLF5 was less found in the peritoneal tissue of control mice, while KLF5 was expressed in the thickened submesothelial area of CG-injected mice receiving the vehicle. Am80 treatment reduced KLF5 expression and remarkably attenuated peritoneal thickening, accompanied with the reduction of type III collagen expression. The numbers of transforming growth factor ß-positive cells, α-smooth muscle actin-positive cells and infiltrating macrophages were significantly decreased in Am80-treated group. PET revealed the increased peritoneal permeability in CG mice, whereas Am80 administration significantly improved the peritoneal high permeability state. CONCLUSIONS: These results indicate the involvement of KLF5 in the progression of experimental peritoneal fibrosis and suggest that Am80 may be potentially useful for the prevention of peritoneal fibrosis through inhibition of KLF5 expression.

Renal outcomes of treatment with telmisartan in patients with stage 3-4 chronic kidney disease: A prospective, randomized, controlled trial (JINNAGA).

OBJECTIVES: Although angiotensin II receptor blockers are effective for patients with chronic kidney disease, dose-dependent renoprotective effects of angiotensin II receptor blockers in patients with moderate to severe chronic kidney disease with non-nephrotic proteinuria are not known. Our aim was to elucidate the dose-dependent renoprotective effects of angiotensin II receptor blockers on such patients. METHODS: A multicenter, prospective, randomized trial was conducted from 2009 to 2014. Patients with non-nephrotic stage 3-4 chronic kidney disease were randomized for treatment with either 40 or 80 mg telmisartan and were observed for up to 104 weeks. Overall, 32 and 29 patients were allocated to the 40 and 80 mg telmisartan groups, respectively. The composite primary outcome was renal death, doubling of serum creatinine level, transition to stage 5 chronic kidney disease, and death from any cause. Secondary outcomes included the level of urinary proteins and changes in the estimated glomerular filtration rate. RESULTS: There was no difference in the primary outcome (p = 0.78) and eGFR (p = 0.53) between the two groups; however, after 24 weeks, urinary protein level was significantly lower in the 80 mg group than in the 40 mg group (p < 0.05). No severe adverse events occurred in either group, and the occurrence of adverse events did not significantly differ between them (p = 0.56). CONCLUSION: Our findings do not demonstrate a direct dose-dependent renoprotective effect of telmisartan. The higher telmisartan dose resulted in a decrease in the amount of urinary protein. Even though high-dose angiotensin II receptor blockers may be preferable for patients with stage 3-4 chronic kidney disease, the clinical importance of the study results may be limited. The study was registered in the UMIN-CTR (https://www.umin.ac.jp/ctr) with the registration number UMIN000040875.

A case of membranoproliferative glomerulonephritis and AA amyloidosis complicated with pulmonary nontuberculous mycobacterial infection.

A 75-year-old man was diagnosed with pulmonary nontuberculous mycobacterial (NTM) infection in February 2005 and was treated with rifampicin, ethambutol, and clarithromycin. However, the infection was resistant to treatment, and his chest radiograph showed an abnormality that gradually seemed to aggravate. The patient's sputum was positive for Mycobacteria. Moreover, the patient had dyspnea and an underlying chronic inflammation in the lungs. He visited our hospital because of dyspnea and leg edema in June 2011. Laboratory evaluation on admission revealed proteinuria (6 g/day) and decreased serum total protein (5.8 g/dL) and albumin (1.6 g/dL) levels, indicating nephrotic syndrome. Percutaneous renal biopsy revealed membranoproliferative glomerulonephritis (MPGN) in the acute stage and AA amyloidosis of mild degree. AA amyloidosis was also diagnosed histologically on gastric and colonic biopsy, in addition to renal biopsy. His renal function decreased gradually, and therefore, he underwent hemodialysis therapy in January 2012. However, his gastrointestinal-related symptoms persisted, and his appetite diminished, because of which he had become severely malnourished; he died 8 months later. This is a rare case of a patient with two different renal lesions (MPGN and AA amyloidosis) complicated with NTM. Our case suggests that MPGN and amyloidosis should be considered in elderly patients with nephrotic syndrome onset and chronic inflammation.

A multicenter randomized controlled trial of tonsillectomy combined with steroid pulse therapy in patients with immunoglobulin A nephropathy.

BACKGROUND: The study aim was, for the first time, to conduct a multicenter randomized controlled trial to evaluate the effect of tonsillectomy in patients with IgA nephropathy (IgAN). METHODS: Patients with biopsy-proven IgAN, proteinuria and low serum creatinine were randomly allocated to receive tonsillectomy combined with steroid pulses (Group A; n = 33) or steroid pulses alone (Group B; n = 39). The primary end points were urinary protein excretion and the disappearance of proteinuria and/or hematuria. RESULTS: During 12 months from baseline, the percentage decrease in urinary protein excretion was significantly larger in Group A than that in Group B (P < 0.05). However, the frequency of the disappearance of proteinuria, hematuria, or both (clinical remission) at 12 months was not statistically different between the groups. Logistic regression analyses revealed the assigned treatment was a significant, independent factor contributing to the disappearance of proteinuria (odds ratio 2.98, 95% CI 1.01-8.83, P = 0.049), but did not identify an independent factor in achieving the disappearance of hematuria or clinical remission. CONCLUSIONS: The results indicate tonsillectomy combined with steroid pulse therapy has no beneficial effect over steroid pulses alone to attenuate hematuria and to increase the incidence of clinical remission. Although the antiproteinuric effect was significantly greater in combined therapy, the difference was marginal, and its impact on the renal functional outcome remains to be clarified.

Overestimation of the risk of progression to end-stage renal disease in the poor prognosis' group according to the 2002 Japanese histological classification for immunoglobulin A nephropathy.

BACKGROUND: The current (2012) histological classification of immunoglobulin A nephropathy was established using a case-control study of 287 patients. However, the risk of progression to end-stage renal disease (ESRD) has not been validated for the previous (2002) classification. This study aimed to determine whether the previous classification could identify the risk of long-term renal outcome through re-analysis of the 2012 cohort. METHODS: On the basis of the 2002 classification, namely 'good prognosis', 'relatively good prognosis', 'relatively poor prognosis', and 'poor prognosis', we examined the clinical data at the time of biopsy, the correlation between the 2002 classification and long-term renal outcomes, and a patient-by-patient correlation between the 2002 and 2012 classification systems. This was performed by analyzing samples from the 287 patients used to establish the 2012 classification. RESULTS: The rate of decline of estimated glomerular filtration rate was greater and the odds ratio of progression to ESRD was higher in the 'poor prognosis' group. In contrast, the odds ratio for renal death was comparable between the groups described as 'relatively poor prognosis' and 'relatively good prognosis' in the 2002 classification. Many patients in the 2002 classification were classified with a lower histological grade in the current classification, but none were classified with a higher grade. CONCLUSIONS: The 2002 classification could also identify the risk of progression to ESRD. However, it was overestimated for patients in the 'poor prognosis' group in the 2002 classification, as that group included patients with milder histological damage.

Involvement of apoptosis inhibitor of macrophages in a rat hypertension model with nephrosclerosis: possible mechanisms of action of olmesartan and azelnidipine.

Stroke-prone spontaneously hypertensive (SHRsp) rats develop severe hypertension resulting in renal injury. We investigated apoptosis inhibitor of macrophages (AIM) expression in nephrosclerotic rats and the involvement of AIM in olmesartan (OLM)- and azelnidipine (AZN)-induced decreases in the number of macrophages infiltrating the kidney. We randomly assigned 20-week-old male SHRsp rats to receive one of the following substances every day for 12 weeks: water (vehicle), hydralazine (HYD), OLM, or AZN. Renal damage was assessed by Masson trichrome staining. Expressions of ED-1, AIM, and oxidized low-density lipoprotein (oxLDL) were immunohistochemically detected. Apoptosis was analyzed by terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) staining. All treatment groups showed significantly less renal interstitial fibrosis than the vehicle group. AZN and OLM groups had significantly fewer AIM-expressing cells than the HYD and vehicle groups. The ratios AIM-positive cells/ED-1-positive macrophages and TUNEL-positive cells/ED-1-positive macrophages in the AZN and OLM groups were lower and higher, respectively, than the the HYD and vehicle groups. oxLDL expression in the renal interstitium was significantly lower in treatment groups compared to vehicle group. OLM and AZN inhibited interstitial fibrosis progression in SHRsp rats by suppressing AIM expression in macrophages, followed by reducing the number of infiltrating macrophages.

Involvement of leptin in the progression of experimentally induced peritoneal fibrosis in mice.

Leptin is a hormone mainly produced by white adipose cells, and regulates body fat and food intake by acting on hypothalamus. Leptin receptor is expressed not only in the hypothalamus but in a variety of peripheral tissues, suggesting that leptin has pleiotropic functions. In this study, we investigated the effect of leptin on the progression of peritoneal fibrosis induced by intraperitoneal injection of chlorhexidine gluconate (CG) every other day for 2 or 3 weeks in mice. This study was conducted in male C57BL/6 mice and leptin-deficient ob/ob mice. Peritoneal fluid, blood, and peritoneal tissues were collected 15 or 22 days after CG injection. CG injection increased the level of leptin in serum and peritoneal fluid with thickening of submesothelial compact zone in wild type mice, but CG-injected ob/ob mice attenuate peritoneal fibrosis, and markedly reduced the number of myofibroblasts, infiltrating macrophages, and blood vessels in the thickened submesothelial area. The 2-week leptin administration induced a more thickened peritoneum in the CG-injected C57BL/6 mice than in the PBS group. Our results indicate that an upregulation of leptin appears to play a role in fibrosis and inflammation during peritoneal injury, and reducing leptin may be a therapeutically potential for peritoneal fibrosis.

Association between cystatin C and arteriosclerosis in the absence of chronic kidney disease.

AIM: Chronic kidney disease (CKD) is a known risk factor for cardiovascular disease (CVD). Cystatin C was recently reported to be an endogenous surrogate of kidney function, and a high level of cystatin C is reported to be a strong predictor of CVD; however, the association between cystatin C and arteriosclerosis in a non-CKD population is unclear. This study aimed to clarify the association between cystatin C and arteriosclerosis in a non-CKD population. METHODS: Of the 637 Japanese adults (264 men, 373 women) enrolled, we analyzed 446 participants with an estimated glomerular filtration rate (eGFR) >60 mL/min and no proteinuria (177 men, 269 women) without a history of CVD. Kidney function was evaluated according to serum cystatin C levels and eGFR. Arteriosclerosis was evaluated on the basis of the cardio-ankle vascular index (CAVI) and carotid intima-media thickness (CIMT). RESULTS: The mean age of our subjects was 67.0±10.0 years. No variables showed any significant differences according to gender. The results of multiple linear regression analysis showed a significant correlation between serum cystatin C and CAVI only in women, but not CIMT. CONCLUSION: We observed a significant correlation between cystatin C and CAVI, which is a marker of early-stage arteriosclerosis, in women in a non-CKD population with no proteinuria and eGFR>60 mL/min.

A histologic classification of IgA nephropathy for predicting long-term prognosis: emphasis on end-stage renal disease.

BACKGROUND: A multicenter case-control study on IgA nephropathy (IgAN) was conducted to develop an evidence-based clinicopathologic classification of IgAN for predicting long-term renal outcome. METHODS: Two hundred and eighty-seven patients including those with isolated hematuria or very mild proteinuria were enrolled. During a median follow-up of 9.3 years after biopsy, 49 patients (17%) progressed to end stage renal disease (ESRD). The associations between pathological variables and the need for chronic dialysis was examined by multivariate logistic regression analysis separately in patients who required dialysis earlier than 5 years (Early Progressors) and those who required dialysis within 5 to 10 years (Late Progressors) after biopsy. RESULTS: Independent pathological variables predicting progression to ESRD were global sclerosis, segmental sclerosis and fibrous crescents for Early Progressors, and global sclerosis and cellular/fibrocellular crescents for Late Progressors. Four histological grades, HG 1, HG 2, HG 3 and HG 4, were established corresponding to <25%, 25-49%, 50-74% and =75% of glomeruli exhibiting cellular or fibrocellular crescents, global sclerosis, segmental sclerosis or fibrous crescents. Eleven (7%) patients in HG 1, 12 (16%) in HG 2, 13 (31%) in HG 3 and 13 (68%) in HG 4 progressed to ESRD. Multivariate logistic analysis revealed that the risk of progression to ESRD was significantly higher in HG 2, 3 and 4 than in HG 1 (odds ratio, 2.4, 5.7 and 27.6 vs. 1.0). CONCLUSIONS: Our evidence-based histologic classification can identify the magnitude of the risk of progression to ESRD and is useful for predicting long-term renal outcome in IgAN.

Recombinant human erythropoietin attenuates renal tubulointerstitial injury in murine adriamycin-induced nephropathy.

BACKGROUND: Erythropoietin (EPO) has been found to provide cytoprotection against acute ischemic and toxic renal tubulointerstitial injury. This study aimed to elucidate the mechanism(s) underlying EPO protection while examining whether EPO provides tubulointerstitial protection in a mouse model with adriamycin (ADR)-induced tubulointerstitial injury. METHODS: Adriamycin nephropathy (AN) was induced by a single injection of ADR in the 2 experimental groups on day 0. The saline-control group and the AN-saline group were administered saline at days 7, 14, and 21, while the EPO-control group and the AN-EPO group were administered EPO at days 7, 14, and 21. Kidneys were harvested at days 14 and 28 after ADR injection to measure the expression levels of the EPO receptor (EPO-R), CD34, and phosphorylated Akt by immunohistochemistry; to determine the extent of apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) and active caspase-3 staining; and to map the hypoxic area by pimonidazole staining. RESULTS: EPO-R was detected in glomerular, tubular epithelial, and endothelial cells. EPO administration significantly improved tubulointerstitial injury, decreased the number of TUNEL-positive and active caspase-3-positive cells, and increased the phosphorylated-Akt-positive area in the tubulointerstitial area without increasing the hemoglobin or hematocrit levels. CONCLUSIONS: EPO provides renoprotection against AN by reducing apoptotic cell death and preserving peritubular capillaries, possibly by exerting pleiotropic effects independently of its hemopoietic effects.

Renal thrombotic microangiopathies/thrombotic thrombocytopenic purpura in a patient with primary Sjögren's syndrome complicated with IgM monoclonal gammopathy of undetermined significance.

Thrombotic microangiopathy (TMA)/thrombotic thrombocytopenic purpura (TTP) is a rare but potentially lethal condition requiring rapid recognition, diagnosis, and initiation of therapy. We experienced a case of a 61-year-old woman with primary Sjögren's syndrome (pSS) complicated with severe renal TMA/TTP following IgM monoclonal gammopathy of undetermined significance (MGUS). She was admitted to our hospital for further evaluation of hypergammaglobulinema, acute renal failure, and severe thrombocytopenia. She had been diagnosed with pSS 13 years prior to admission. Histological examination of her kidney revealed fibrin thrombi in the glomeruli and arterioles, a finding that is consistent with TMA/TTP. The patient was subsequently treated with plasma exchange, which resulted in a successful outcome without any complications. This rare case suggests that it is important to make a therapeutic decision based on appropriate and prompt pathological diagnosis.

22-Oxacalcitriol prevents progression of peritoneal fibrosis in a mouse model.

OBJECTIVE: Vitamin D plays an important role in calcium homeostasis and is used to treat secondary hyperparathyroidism among dialysis patients. The biologic activity of vitamin D and its analogs is mediated by vitamin D receptor (VDR), which is distributed widely throughout the body. Recent papers have revealed that low vitamin D levels are correlated with severe fibrosis in chronic diseases, including cystic fibrosis and hepatitis. The aim of the present study was to evaluate the protective effects of vitamin D against the progression of peritoneal fibrosis. METHODS: Peritoneal fibrosis was induced by injection of chlorhexidine gluconate (CG) into the peritoneal cavity of mice every other day for 3 weeks. An analog of vitamin D, 22-oxacalcitriol (OCT), was administered subcutaneously daily from initiation of the CG injections. The peritoneal tissue was excised at 3 weeks. Changes in morphology were assessed by hematoxylin and eosin staining. Expression of VDR, alpha smooth muscle actin (as a marker of myofibroblasts), type III collagen, transforming growth factor ß(TGF-ß), phosphorylated Smad2/3, F4/80 (as a marker of macrophages), and monocyte chemoattractant protein-1 (MCP-1) was examined by immunohistochemistry. Southwestern histochemistry was used to detect activated nuclear factor κB (NF-κB). RESULTS: In the CG-injected mice, immunohistochemical analysis revealed expression of VDR in mesothelial cells, myofibroblasts, and macrophages in the thickened submesothelial zone. Treatment with OCT significantly prevented peritoneal fibrosis and reduced the accumulation of type III collagen in CG-treated mice. Among the markers of fibrosis, the numbers of myofibroblasts, cells positive for TGF-ß, and cells positive for phosphorylated Smad2/3 were significantly decreased in the OCT-treated group compared with the vehicle-treated group. Furthermore, OCT suppressed inflammatory mediators of fibrosis, as shown by the reduced numbers of activated NF-κB cells, macrophages, and MCP-1-expressing cells. CONCLUSIONS: Our results indicate that OCT attenuates peritoneal fibrosis, an effect accompanied by reduced numbers of myofibroblasts, infiltrating macrophages, and TGF-ß-positive cells, suggesting that vitamin D has potential as a novel therapeutic agent for preventing peritoneal sclerosis.

Production and degradation of extracellular matrix in reversible glomerular lesions in rat model of habu snake venom-induced glomerulonephritis.

We investigated the mechanism of development and repair process of glomerular injury in a rat model of habu snake (Trimeresurus flavoviridis) venom (HSV)-induced glomerulonephritis. Glomerulonephritis was induced in rats by intravenously injecting HSV at 3 mg/kg. Renal tissue was isolated and subjected to immunohistochemical analysis for expression levels of type IV collagen, heat shock protein 47 (HSP47), transforming growth factor-ß (TGF-ß), and matrix metalloproteinase-3 (MMP-3), as well as its transcription factor Ets-1. Expression levels of HSP47, TGF-ß, and type IV collagen began to increase in the mesangial area starting from day 14 and peaked on day 21, followed by a gradual decrease. Expression levels of MMP-3 and Ets-1 started to increase coinciding with peak production of mesangial matrix on day 21, peaking on day 35, followed by gradual decrease. Expression of MMP-3 and Ets-1 persisted until day 63, whereas that of HSP47 and type IV collagen returned to baseline level at this time point. Time-course changes of extracellular matrix (ECM) accumulation in glomeruli in the HSV-induced glomerulonephritis model were correlated with those of factors involved in both ECM production and degradation systems. Continued expression of factors in the degradation system seems particularly important for the repair process. These findings might lead to new therapies that prevent and repair glomerular injury.

Identification of a novel mutation and prevalence study for fabry disease in Japanese dialysis patients.

Fabry disease--a genetic disorder characterized by the accumulation of globotriaosylceramide in cell lysosomes resulting from an X-linked deficiency of α-galactosidase A activity--presents with multiorgan manifestations, including progressive renal disease. Recently, its prevalence has been reported to be higher in hemodialysis (HD) patients than in the general population. We, therefore, examined patients on maintenance dialysis living in the Nagasaki Prefecture, Japan, to clarify the prevalence of Fabry disease. We screened 933 patients on maintenance dialysis, who were residents of Nagasaki Prefecture in Japan, for α-galactosidase A activity using a dried blood spot on filter paper. Patients with low α-galactosidase A activity were clinically assessed; subsequently, genetic analysis of the α-Galactosidase A gene (MIM:30064) was performed in these patients. Of the 933 patients, 55 had low α-galactosidase A activity; of these, one male and two females had α-Galactosidase A mutations. The prevalence of Fabry disease was thus 0.32%, which was similar to that reported previously. However, one mutation was newly identified, while the E66Q mutation observed in two patients was as previously identified. These two patients with the E66Q mutation were excluded because of the possibility of polymorphism; the prevalence of Fabry disease in the HD population was finally calculated to be 0.11%. The prevalence of Fabry disease in patients on maintenance dialysis living in Nagasaki Prefecture was 0.32%. Dried blood spot screening was considered as a simple and effective method for screening patients on maintenance dialysis for Fabry disease.

Involvement of lymphocyte infiltration in the progression of mouse peritoneal fibrosis model.

Peritoneal fibrosis is a serious complication in patients with severe chronic kidney disease who are undergoing peritoneal dialysis (PD). One of the pathological characteristics of peritoneal fibrosis is the infiltration of macrophages in the thickened submesothelial compact zone. In addition, infiltration of lymphocytes, including T and B lymphocytes, is observed in the fibrotic peritoneum. However, the relationship between lymphocyte infiltration and progression of peritoneal fibrosis remains unclear. In this study, we investigated the role of lymphocytes in the development of peritoneal fibrosis induced by chlorhexidine gluconate (CG) by comparing the histological changes observed in severe combined immunodeficient (SCID) mice (largely lacking functional T and B lymphocytes) with those observed in wild-type (WT) mice. As expected, CG-injected WT mice showed a thickening of the submesothelial compact zone together with massive collagen deposition accompanied by increased numbers of infiltrating macrophages and T and B lymphocytes. In the peritoneum of SCID mice, the submesothelial compact zone was thicker and the number of macrophages and B lymphocytes was significantly higher than that observed in control immunodeficient and WT mice. In contrast, the number of T lymphocytes in the peritoneum of SCID mice was significantly lower than that in the peritoneum of WT mice. These results suggest that T and B lymphocytes modulate the process of peritoneal fibrosis via macrophage infiltration.

Glomerular repair retardation via blocking of angiotensin II type 1a receptor pathway in a mouse glomerulonephritis model.

BACKGROUND/AIMS: To examine the role of the angiotensin II (ATII) type 1a receptor (AT1-R) pathway in renal tissue damage and repair, we investigated reversible glomerular injury in a mouse model of habu snake venom (HSV)-induced glomerulonephritis using AT1-R-deficient (AT1a-/-) mice and AT1-R antagonist-treated mice. METHODS: Experimental glomerulonephritis was induced by single administration of HSV to AT1a(+/+) mice (HSV group) and AT1a(-/-) mice (KO-HSV group) and AT1-R antagonist-treated BL6 mice (HSV-ARB group). Morphological change and expression levels of type IV collagen, CD31, and vascular endothelial growth factor (VEGF) were analyzed. RESULTS: The HSV group showed increased mesangial matrix expansion on day 7, which returned to preinjection levels by day 56, while mes-angial matrix expansion and increased type IV collagen expression were seen throughout days 7 to 56 in the KO-HSV group. The KO-HSV group showed fewer CD31-positive capillary loops and a marked decrease in the number of VEGF-positive cells in the glomeruli than the HSV group. VEGF administration to the KO-HSV group facilitated glomerular capillary repair and reconstruction. The HSV-ARB group showed the same delay in glomerular repair as that seen in the KO-HSV group. CONCLUSION: Our results indicate that blocking of the ATII-AT1R pathway delays glomerular repair via angiogenesis inhibition, followed by reduced induction of VEGF.

Epigallocatechin gallate suppresses peritoneal fibrosis in mice.

Long-term peritoneal dialysis (PD) leads to histological changes in the peritoneal membrane. Angiogenesis and inflammation caused by glucose degradation products (GDPs) play crucial roles in peritoneal fibrosis. One such GDP is methylglyoxal (MGO), which enhances the formation of advanced glycation end products (AGEs). AGEs bind to their receptor (RAGE) and activate nuclear factor-κB (NF-κB), which is a key regulator of angiogenesis and inflammation. Recent studies have indicated that (-)-epigallocatechin gallate (EGCG), a tea polyphenol, inhibits angiogenesis and inflammation. Here, we examined whether EGCG suppresses peritoneal fibrosis in mice. Based on preliminary examination, 2mL of 40mM MGO or PD fluid was injected intraperitoneally and EGCG (50mg/kg) or saline was injected subcutaneously for 3weeks. In comparison to PD fluid+saline-treated mice, the peritoneal tissues of MGO+saline-treated mice showed marked thickening of the submesothelial compact zone. In the submesothelial compact zone of the MGO+saline-treated mice, CD31-positive vessels and vascular endothelial growth factor-positive cells were significantly increased, as were inflammation, F4/80-positive macrophages, and monocyte chemotactic protein-1. Moreover, 8-hydroxydeoxyguanosine, a marker of reactive oxygen species, and NF-κB, determined by Southwestern histochemistry, in the submesothelial compact zone were also increased in MGO+saline-treated mice. These changes were attenuated in MGO+EGCG-treated mice. We demonstrated that EGCG treatment suppresses peritoneal fibrosis via inhibition of NF-κB. Furthermore, EGCG inhibits reactive oxygen species production. The results of this study indicate that EGCG is a potentially novel candidate for the treatment of peritoneal fibrosis.

Imaging mass spectrometry analysis reveals an altered lipid distribution pattern in the tubular areas of hyper-IgA murine kidneys.

Immunoglobulin A (IgA) nephropathy is the most common glomerular disease worldwide. To investigate the pathogenesis of this renal disease, we used animal models that spontaneously develop mesangioproliferative lesions with IgA deposition, which closely resemble the disease in humans. We analyzed the molecular distribution of lipids in hyper-IgA (HIGA) murine kidneys using matrix-assisted laser desorption/ionization-quadrupole ion trap-time of flight (MALDI-QIT-TOF)-based imaging mass spectrometry (IMS), which supplies both spatial distribution of the detected molecules and allows identification of their structures by their molecular mass signature. For both HIGA and control (Balb/c) mice, we found two phosphatidylcholines, PC(16:0/22:6) and PC(18:2/22:6), primarily located in the cortex area and two triacylglycerols, TAG(16:0/18:2/18:1) and TAG(18:1/18:2/18:1), primarily located in the hilum area. However, several other molecules were specifically seen in the HIGA kidneys, particularly in the tubular areas. Two HIGA-specific molecules were O-phosphatidylcholines, PC(O-16:0/22:6) and PC(O-18:1/22:6). Interestingly, common phosphatidylcholines and these HIGA-specific ones possess 22:6 lipid side chains, suggesting that these molecules have a novel, unidentified renal function. Although the primary structure of the HIGA-specific molecules corresponding to m/z 854.6, 856.6, 880.6, and 882.6 remained undetermined, they shared similar fragmentation patterns, indicating their relatedness. We also showed that all the HIGA-specific molecules were derived from urine, and that artificial urinary stagnation-due to unilateral urethral obstruction-caused HIGA-specific distribution of lipids in the tubular area.

Thalidomide prevents the progression of peritoneal fibrosis in mice.

Thalidomide is clinically recognized as a therapeutic agent for multiple myeloma and has been known to exert anti-angiogenic actions. Recent studies have suggested the involvement of angiogenesis in the progression of peritoneal fibrosis. The present study investigated the effects of thalidomide on the development of peritoneal fibrosis induced by injection of chlorhexidine gluconate (CG) into the mouse peritoneal cavity every other day for 3 weeks. Thalidomide was given orally every day. Peritoneal tissues were dissected out 21 days after CG injection. Expression of CD31 (as a marker of endothelial cells), proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), α-smooth muscle actin (as a marker of myofibroblasts), type III collagen and transforming growth factor (TGF)-ß was examined using immunohistochemistry. CG group showed thickening of the submesothelial zone and increased numbers of vessels and myofibroblasts. Large numbers of VEGF-, PCNA-, and TGF-ß-positive cells were observed in the submesothelial area. Thalidomide treatment significantly ameliorated submesothelial thickening and angiogenesis, and decreased numbers of PCNA- and VEGF-expressing cells, myofibroblasts, and TGF-ß-positive cells. Moreover, thalidomide attenuated peritoneal permeability for creatinine, compared to the CG group. Our results indicate the potential utility of thalidomide for preventing peritoneal fibrosis.

[Case in which renal function improved following stent-graft placement in the aorta two months after the onset of stanford type B acute aortic dissection].

A 48-year-old man was admitted to the Department of Cardiovascular Surgery in our hospital after developing Stanford type B acute aortic dissection with a patent false lumen in July 2008. Conservative treatment involving rest and antihypertensive therapy was provided following admission. Urine volume decreased from day 9, and serum creatinine increased to 7.7 mg/dL. As it was suspected that the reduced renal blood flow was caused by progression of aortic dissection, contrast-enhanced computed tomography (CT)was performed. The left kidney showed reduced enhancement and the right kidney was heterogeneously enhanced. The dissection had extended to the left renal artery, and the reduced renal blood flow caused by narrowing of the left renal artery was thought to have caused the renal dysfunction. As elevated urea nitrogen and serum creatinine levels and hyperkalemia persisted, hemodialysis was performed a total of four times. Although the patient was subsequently withdrawn from dialysis, he continued to display severe renal dysfunction and was transferred to our department on day 28 for the treatment of renal failure. Conservative treatment was continued, but the maximum diameter of the thoracic aorta gradually increased, and stent placement at the entry of aortic dissection was indicated. On day 86, two stent-grafts were placed for entries at the distal site of the descending aorta and the distal site of the aortic arch. Postoperative abdominal contrast-enhanced CT showed expansion of the true lumen, and blood flow and contrast enhancement improved in both kidneys. Postoperatively, serum creatinine gradually decreased, improving to 1.16 mg/dL on day 96. Renography in the third month after stent-graft placement showed improved renal function in both kidneys. These findings suggest that even at approximately 2 months after the onset of acute renal failure associated with aortic dissection, renal function can be improved by restoring blood flow in the renal arteries.