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The transcription factor nuclear factor-κB (NF-κB) is involved in inflammatory and immune responses through induction of various cytokines and growth factors. The aim of this study is to examine the correlation between NF-κB expression and severity of tissue injury in immunoglobulin A (IgA) nephropathy and the mechanism of such correlation.

CD80 and CD86, cell-surface molecules found only on antigen-presenting cells (APCs), are required for activation of CD4-postitve (CD4+) T cells by interaction with CD28/cytotoxic T-lymphocyte-associated antigen 4 on T cells. The roles of these molecules in human glomerulonephritis (GN) presently are unknown.

Background. Minimally invasive radioguided parathyroidectomy (MIRP) for primary hyperparathyroidism for one gland, located by scanning with technetium 99m-labelled sestamibi (MIBI), has been performed. Total parathyroidectomy with autotransplantation or percutaneous ethanol injection therapy (PEIT) for severe secondary hyperparathyroidism (2HPT) has also been performed.Methods. The present study examined the possibility of maintaining parathyroid function within a target range [intact parathyroid hormone (i-PTH) ≤300 pg/ml] in the long term after MIRP for 2HPT. Three patients resistant to calcitriol therapy gave their informed consent for MIRP. The principle of MIRP for chronic dialysis patients is to extract a hyper-functioning parathyroid gland resistant to medical therapy, including calcitriol pulse therapy, and then control the remaining glands with medical therapy. The follow-up period for this study was 2 years.Result. Two of the cases were controlled by MIRP followed by calcitriol pulse therapy. In all three cases, MIBI scintigraphy showed a solitary radioactive nodule; however, ultrasonography showed that in the two cases that were controlled by MIRP and calcitriol pulse therapy, there was one radioactive gland, but in the other case there were three, and this case required additional PEIT for control of hyperparathyroidism.

Background. Secondary hyperparathyroidism (2HPT) is one of the most important complications in chronic dialysis (CD) patients. Percutaneous ethanol injection therapy (PEIT) of the parathyroid glands was introduced initially as an alternative treatment to parathyroidectomy and, with the technical progress of parathyroid imaging, it has now become a useful adjunct to medical therapy. The present study examined the possiblity of maintaining parathyroid function in the long term (3 years) after PEIT.Method. PEIT, guided by power-Doppler flow mapping, was performed in 33 CD patients with severe 2HPT, and all glands >5.0 mm in diameter were destroyed.Results. All patients showed a decline in the serum intact parathyroid hormone (i-PTH) concentration, on average from 695.5 to 248.0 pg/ml, after 1 year. After 3 years, the i-PTH concentration was controlled at <300 pg/ml in 85% of patients. The mean serum alkaline phosphatase (ALP) concentration also decreased from 322.7 to 154.4 IU/l after 1 year. In 76% of patients, ALP was maintained within the normal range (between 76 and 260 IU/l) at 3 years. Patients were classified into four groups according to the number of parathyroid glands detected by ultrasonography: one gland in group 1, two in group 2, three in group 3, and four in group 4. At 3 years after PEIT, i-PTH was controlled at <300 pg/ml in 100, 79, 83 and 82% of the patients in groups 1-4, respectively.Conclusions. It was possible to maintain long-term parathyroid function after PEIT in patients with 2HPT by using medical therapy, such as oral calcitriol pulse therapy and additional PEIT.

Background:Pentosidine, an advanced glycation end product, accumulates in plasma proteins of uremic patients. Its fate is, however, yet to be fully understood. Methods:Three cell lines, JTC-12 (proximal tubular cells), MDCK (distal tubular cells), and BALB3T3 (nonrenal cells), were cultured in a double chamber system and were exposed to uremic serum, and the contents of protein-linked pentosidine derived from uremic sera were determined in each medium by HPLC assay. The presence of pentosidine in the cytoplasm of these cells was assessed by immunoperoxidase staining. Results:When the apical cell membrane was exposed to uremic serum (fortified in the upper chamber), the contents of protein-linked pentosidine in the upper medium decreased by up to 30% after 24- and 48-hour incubations of JTC-12 cells but not of other cells. On the other hand, the contents of protein-linked pentosidine in the lower medium did not change. By contrast, exposure of the basolateral cell membrane of the three cell lines to uremic serum (fortified in the lower chamber) did not change the contents of protein-linked pentosidine both in the upper and lower medium after a 24-hour incubation. Pentosidine was detected immunohistochemically in the cytoplasm of JTC-12 cells, but not of BALB3T3 and MDCK cells, the apical membranes of which were exposed to uremic sera for 8 h. The immunoreaction disappeared 48 h after exposure. Pentosidine was not detected in the cytoplasm of JTC-12 cells, the basolateral membranes of which were exposed to uremic sera. The relevance of the in vitro results to humans was demonstrated by immunohistochemical studies in normal human kidney tissues showing that pentosidine was identified in the proximal renal tubules. Conclusion:These results suggest that the proximal tubular cells play a role in the disposal of plasma pentosidine.

Background/Aim:Progressive expansion of mesangial matrix and glomerular basement membrane thickening represent alterations in the balance between synthesis and degradation of glomerular extracellular matrix (ECM) protein and are hallmarks of diabetic nephropathy. In order to elucidate the basis for this imbalance between the synthesis and the degradation of ECM in renal tissues from patients of type 1 diabetes mellitus (type 1D) with diabetic nephropathy (DN), we examined the expression of α1 chain of type IV collagen (IV-C), matrix metalloproteinase-2 and -3 (MMP-2, MMP-3), tissue inhibitor of metalloproteinase-1 (TIMP-1) and β-actin mRNA using a high-resolution in situ hybridization with digoxigenin-labeled oligonucleotide. Methods:Patients were divided into two groups based on both of degree of mesangial expansion using electron microscopic point counting morphometric methods and duration of type 1D: 7 ‘fast-track’ patients were selected for their very rapid development of DN structural changes and 8 ‘slow-track’ patients for their very slow development of DN structural changes. Seven normal human kidney (NHK) tissues were used as controls. Results:Positive cells for each mRNA were observed in glomerular resident cells, including glomerular mesangial, epithelial and endothelial cells and cells of Bowman’s capsule. The percentage of glomerular cells positive for IV-C, MMP-2 and MMP-3 mRNA was significantly greater in the ‘slow-track’ vs. ‘fast-track’ patients. No significant differences in percentage positive cells was seen for β-actin mRNA. Furthermore, to elucidate the total number of positive cells per glomerulus for each mRNA, we estimated total cell number of glomerulus using morphometric techniques on light microscopy tissues. The total cell number per glomerulus was significantly greater in ‘fast-track’ than that in ‘slow-track’ patients and NHK. The total number of positive cells per glomerulus for MMP-2 in NHK was significantly greater than that in ‘slow-track’ and ‘fast-track’ patients. Conclusion:Thus, IV-C, MMP-2, MMP-3 and TIMP-1 mRNA are expressed in resident glomerular cells in renal tissues from NHK and type 1D. Glomerular alterations in these in situ mRNA expressions sufficient to explain ECM accumulation and DN risk were not uncovered. These largely negative results could be due to methodologic quantitative imprecision or could indicate that post-translational differences account for ECM imbalance in DN. However, these studies make it clear that unraveling the nature of the ECM production/removal imbalance in DN will require careful consideration of alterations in glomerular cell number.

There is much debate over the origins of fibroblast-type cells that accumulate in interstitial fibrosis. A controversial hypothesis, supported by data from animal and cell-culture studies, is that fibroblast-type cells can derive from tubular epithelial cells by a process of epithelial-mesenchymal transdifferentiation. However, to date, no evidence supports this postulate in human glomerulonephritis. This study sought to provide evidence that tubular epithelial cells can undergo phenotypic change toward a fibroblast-like cell in human glomerulonephritis. One hundred twenty-seven open renal biopsy specimens from patients with minimal change disease (MCD), immunoglobulin A (IgA) nephropathy, and rapidly progressive glomerulonephritis (RPGN) were examined for tubular phenotypic change by two-color immunohistochemistry using the criteria of de novo expression of α-smooth muscle actin (α-SMA), a myofibroblast marker; loss of the epithelial marker cytokeratin; and collagen production. In normal human kidney and MCD, tubular epithelial cells expressed cytokeratin with no evidence of α-SMA staining. However, in 36 of 90 cases of IgA nephropathy and 9 of 18 cases of RPGN, small numbers of tubular epithelial cells in areas of fibrosis showed de novo α-SMA expression, accounting for 0.4% ± 0.2% (IgA nephropathy) and 3.8% ± 1.5% (RPGN) of cortical tubules. An intermediate stage of phenotypic change was observed in some cuboidal epithelial cells that expressed both cytokeratin and α-SMA. Tubules containing α-SMA-positive (α-SMA+) cells also stained for collagen types I and III, suggesting that tubular cells undergoing phenotypic change have an active role in the fibrotic process. There also was a marked increase in transforming growth factor-β1 (TGF-β1) tubular expression in areas with interstitial fibrosis, including tubules with phenotypic change. There was a highly significant correlation between tubular α-SMA expression and interstitial fibrosis, interstitial α-SMA+myofibroblast accumulation, deposition of collagen types I and III, tubular TGF-β1 expression, and renal dysfunction. In conclusion, this study provides evidence that tubular epithelial cells can undergo phenotypic change toward a myofibroblast-like phenotype on the basis of de novo α-SMA expression, loss of cytokeratin, and de novo collagen staining. These data, although not conclusive, provide the first support for the hypothesis that transdifferentiation of tubular epithelial cells has a role in progressive renal fibrosis in human glomerulonephritis. © 2001 by the National Kidney Foundation, Inc.

Mesangial cells play critical roles in maintaining a structure and function of the glomerulus. We previously cloned a novel mesangium-predominant gene, megsin, a new serine protease inhibitor. To clarify localization and roles of megsin protein, we raised polyclonal antibodies to megsin. By immunohistochemistry, megsin protein was specifically identified in the mesangial area. The amount of megsin protein was increased in glomeruli of patients with IgA nephropathy than in those of normal individuals and of patients with minimal change nephrotic syndrome or membranous nephropathy, suggesting a pathophysiological role of megsin as a functional modulator of mesangial functions in situ.

Background:Complement activation is thought to be pathologically important in IgA nephropathy (IgAN). Although C3 deposition in the mesangium is found in IgAN, the origin of C3 is not clear. We recently demonstrated intraglomerular C3 synthesis in the human kidney; however, the activation and pathological role of locally synthesized C3 remains unclear. Here we performed nonradioactive in situ hybridization for C3 mRNA and immunohistochemistry for C3 and its activation products, such as C3d and membrane attack complex (MAC), to determine whether locally produced C3 in glomeruli was activated in IgA nephropathy. Methods:Renal samples from 14 patients with IgAN and 5 with minimal change nephrotic syndrome (MCNS) were examined. Uninvolved portions of surgically removed kidneys with tumors served as normal controls. Results:C3 mRNA was not detected in glomeruli in control tissue and MCNS, but was strongly expressed in resident glomerular cells of IgAN, including mesangial cells, glomerular epithelial cells and the cells of Bowman’s capsule. Examination of serial sections disclosed that more than 70% of cells positive for C3 mRNA were also stained for C3 protein, C3d, and MAC. Double staining for in situ hybridization and immunohistochemistry also revealed that those C3 mRNA signals were present in intraglomerular cells positive for C3. The expression of C3 mRNA and MAC in glomeruli correlated significantly with the degree of mesangial matrix expansion. Conclusions:Our results demonstrated that locally synthesized C3 is activated in the glomeruli of IgAN and that its expression correlated with the severity of mesangial matrix expansion. These findings suggest that activation of C3 may be involved in tissue injury in IgAN through the formation of membrane attack complex.

We studied clinical and histologic parameters at the time of renal biopsy of 19 patients with idiopathic membranous nephropathy (IMN) to investigate the predictors for prognosis of IMN. Nineteen patients diagnosed by open renal biopsy between 1988 and 1993 and followed for at least 5 years were divided into two groups according to the latest follow-up renal function. Group I included 16 patients with normal renal function at the last follow-up point. Group II included three patients with end-stage renal failure at the last follow-up point. Antibodies to CD68, CD45RO, α-SMA, collagen IV, and collagen VI were used to investigate glomerular and interstitial changes in biopsy specimens by the indirect enzyme-labeled antibody method. Degree of global glomerulosclerosis, segmental glomerulosclerosis, adhesion to Bowman's capsule, and crescent formation were evaluated by light microscopy (periodic acid–Schiff, periodic acid-metheramine [PAM] staining). The difference between the two groups was analyzed by Mann-Whitney Utest. The number of interstitial cells, the number of interstitial CD45RO-positive cells, and increases of interstitial collagen IV and VI were found to be the most important factors for prognosis of IMN. These findings suggest that the extent of tubulointerstitial changes (cellular infiltration and fibrosis) determines the prognosis of renal function in IMN.

E-cadherin, the major intercellular adhesion molecule of epithelial cells, is important in determining the architecture of sarcomas, especially those showing epithelioid features. In addition to its role in cell adhesion, -catenin, a cadherin undercoat protein, has been shown to function as a downstream transcriptional activator of the Wnt/Wingless signaling pathway. In order to evaluate the significance of the cadherin cell adhesion system and the Wnt/Wingless signaling pathway in the morphogenesis and/or tumorigenesis of synovial sarcoma (a major type of sarcoma with epithelioid features), immunoreactivity for pan-cadherin, E-cadherin, and their undercoat proteins (-, - ,and -catenins and p120) was evaluated in 15 synovial sarcomas. Immunoreactivity for pan-cadherin, E-cadherin, -catenin, -catenin, and p120 was observed in all 15 specimens. Immunoreactivity for pan-cadherin was stronger than that for E-cadherin. Expression of -catenin was detected in ten specimens. Although -catenin was observed only at the cell-cell boundaries in four specimens, it was present in the nucleus and cytoplasm and at the cell-cell boundaries in the other 11, suggesting constitutional activation of the Wnt/Wingless signaling pathway in synovial sarcoma. Direct sequencing for exon 3 of the -catenin gene, however, revealed no mutations in any of the 15 specimens. In conclusion, other types of cadherin besides E-cadherin, together with cadherin undercoat proteins, may play a role in cell adhesion in synovial sarcoma. Furthermore, mechanisms other than mutation of exon 3 of the -catenin gene may activate the Wnt/Wingless signaling pathway in this type of tumor.

To clarify the incidence and characteristics of hematopoietic cell transplantation (HCT)-related nephropathy (HCT-N) in Japan, we sent questionnaire letters to 188 hematologic divisions of 91 hospitals and analyzed the responses. Of 2,136 Japanese hematopoietic cell transplant recipients, 51 patients (2.4%) had HCT-N. The early-onset (≤30 days after HCT), middle-onset (31 to 120 days after HCT), and late-onset (180 days after HCT) groups included 20, 16, and 15 patients, respectively. The early-onset group mainly consisted of patients with acute renal failure (ARF) and hemolytic uremic syndrome and/or thrombotic thrombocytopenic purpura. ARF was the dominant type in the middle-onset group. The main phenotype of the late-onset group was nephrotic syndrome, which correlated with chronic graft-versus-host disease (P= 0.008). The total amounts of irradiation for patients with chronic renal failure and urinary abnormality were significantly greater than those for patients with ARF (P= 0.004). The survival rate of the early-onset and middle-onset groups was 47.2%, whereas 87% of patients in the late-onset group survived (P= 0.002). HCT-N is expected to become a serious and important problem in Japan because of the increasing number of HCTs from unrelated donors.

Selective percutaneous ethanol injection therapy (PEIT) of the parathyroid glands has been shown to be effective in chronic dialysis patients with severe secondary hyperparathyroidism. In this study, we examined whether it was possible to maintain parathyroid function within target range (intact parathyroid hormone [iPTH], 160 to 360 pg/mL) in the long term after successful destruction of hyperplastic tissue. PEIT was performed in 46 patients resistant to calcitriol pulse therapy, and all glands larger than 5 mm in diameter were destroyed by ethanol, guided by power Doppler flow mapping. Serum iPTH levels decreased from 633.3 ± 359.9 to 226.3 ± 204.7 pg/mL at 3 weeks and were maintained at 289.9 ± 222.4 pg/mL at 1 year after PEIT. Total alkaline phosphatase activity decreased from 384.9 ± 160.1 to 234.0 ± 110.5 IU/L at 1 year after PEIT. In 19 patients, iPTH levels decreased into relative hypoparathyroidism (iPTH < 160 pg/mL) at 3 weeks after PEIT; however, they recovered at 1 year after PEIT (191.1 ± 29.6 pg/mL). Parathyroid function was maintained within target range in 80.4% of the patients at 1 year after PEIT with appropriate medical therapy. Surgical parathyroidectomy was not required in any patient. Conversely, in eight other patients with recurrent hyperparathyroidism after subtotal parathyroidectomy, iPTH levels recovered in only 50% of the patients at 1 year after PEIT. Thus, destruction of hyperplastic tissue should be optimized in such patients. Recurrent nerve palsy was observed in only one patient, but was reversible. In conclusion, selective PEIT guided by color Doppler flow mapping is an effective and safe adjunct to medical therapy with a low risk for hypoparathyroidism.