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Biomedical subjects

M Kaizuka

Publications and source records attributed to M Kaizuka.

At least 19 recordsLinked to original sources

Interleukin-1beta is an autocrine growth factor of rat glomerular epithelial cells in culture.

BACKGROUND: The proliferation of glomerular epithelial cells (GEC) is usually observed in crescentic glomerulonephritis. However, the regulation of GEC proliferation is not fully understood. Although it is known that interleukin-1beta (IL-1beta) has a mitogenic effect on mesangial cells and is produced by mesangial cells, the effect of this cytokine on GEC proliferation is not known. We investigated whether cultured rat GEC could produce IL-1beta, and the role of IL-1beta on GEC proliferation. METHODS: Cultured rat GEC from 24th to 36th passage were used. GEC proliferation was evaluated with a colorimetric assay using the tetrazolium salt. GEC were incubated in K1 medium for 72 h and IL-1beta in the culture supernatants was measured by specific enzyme-linked immunosorbent assay (ELISA). IL-1beta in GEC supernatants was examined by immunoblot analysis. IL-1beta mRNA expression in GEC was examined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: IL-1beta showed a mitogenic effect on GEC, while interferon-gamma (IFN-gamma) and heparin inhibited GEC proliferation. Moreover, GEC proliferation cultured with K1 medium was partially inhibited by anti-IL-1beta neutralizing antibody. Amounts of IL-1beta in the culture supernatants increased over time (24-72 h). K1 medium increased IL-1beta production by GEC, while IFN-gamma or heparin did not change IL-1beta production. Immunoblot analysis revealed 17 kD protein of IL-1beta in the concentrated GEC supernatants. RT-PCR also demonstrated mRNA expression of IL-1beta in GEC. CONCLUSIONS: Our data indicate that IL-1beta is an autocrine growth factor for GEC and may have an important role in the regulation of GEC proliferation.

3T3 Cells↗

Cultured rat glomerular epithelial cells show gene expression and production of transforming growth factor-beta: expression is enhanced by thrombin.

BACKGROUND: Glomerular crescents play an important role in progressive glomerular injury. The lesions consist of epithelial cells, macrophages, and deposits of fibrin and extracellular matrix. Transforming growth factor beta (TGF-beta) contributes to the modulation of cell growth and extracellular matrix synthesis. Thrombin is involved in fibrin formation in crescents. The purpose of this study was to examine whether glomerular epithelial cells (GEC) could produce TGF-beta, and if so, to clarify the role of TGF-beta in GEC proliferation. We also investigated whether thrombin could modulate the production of TGF-beta and extracellular matrix by GEC. METHODS: Bioassay using the TGF-beta-dependent mink pulmonary epithelial cell line (CCL-64), immunoblot analysis, and reverse transcriptase polymerase chain reaction (RT-PCR) were used to demonstrate TGF-beta production by rat GEC. TGF-beta gene expression was examined by RT-PCR in GEC incubated with thrombin, and type IV collagen and fibronectin were quantified by enzyme immunoassay in culture supernatants of GEC incubated with thrombin or TGF-beta. RESULTS: TGF-beta activity was demonstrated in GEC supernatants by bioassay. Immunoblot analysis of concentrated culture supernatants using anti-TGF-beta antibody revealed a 12.5-kDa protein, which was compatible with TGF-beta. Concentrated GEC supernatants inhibited GEC proliferation as well as porcine TGF-beta. RT-PCR demonstrated TGF-beta gene expression in GEC. Thrombin (0.5-5.0 U/ml) enhanced TGF-beta mRNA expression in a dose-dependent manner. Thrombin (5.0 U/ml) and porcine TGF-beta (5.0 ng/ml) stimulated the production of type IV collagen and fibronectin by GEC. CONCLUSIONS: Rat GEC produce TGF-beta in vitro. Thrombin may participate in the progression of glomerulosclerosis in crescentic glomerulonephritis through the stimulation of TGF-beta production by GEC.

Animals↗

Platelet-derived growth factor, basic fibroblast growth factor, and interferon gamma increase type IV collagen production in human fetal mesangial cells via a transforming growth factor-beta-dependent mechanism.

BACKGROUND: Glomerulosclerosis is characterized by glomerular accumulation of extracellular matrix following mesangial cell proliferation. The precise pathomechanism of glomerulosclerosis is still undetermined. Platelet-derived growth factor (PDGF) and basic fibroblast growth factor (b-FGF) are known to be mitogenic for mesangial cells, and interferon gamma (IFN-gamma) is known to have an inhibitory effect on mesangial cell proliferation. We attempted to clarify the role of these cytokines on mesangial matrix production using cultured human fetal mesangial cells (HMC). METHODS: HMC were incubated with these cytokines for 24-72 h and the levels of type IV collagen and TGF-beta in the cell supernatants were measured by enzyme immunoassay. RESULTS: PDGF, b-FGF, and IFN-gamma stimulated type IV collagen production by HMC in a dose- and time-dependent manner. The anti-TGF-beta neutralizing antibody clearly inhibited their stimulatory effect on type IV collagen production. PDGF and b-FGF also stimulated TGF-beta production by HMC in a dose-dependent manner, although IFN-gamma did not. CONCLUSION: PDGF, b-FGF, and IFN-gamma stimulate type IV collagen production in cultured HMC via a TGF-beta-dependent mechanism.

Antibodies↗

C-Type natriuretic peptide inhibits proliferation and monocyte chemoattractant protein-1 secretion in cultured human mesangial cells.

BACKGROUND: Mesangial cell proliferation and matrix accumulation are hallmarks of various progressive glomerular diseases. We examined whether C-type natriuretic peptide (CNP) that is known to regulate the proliferation of vascular smooth muscle cells could modulate these pathological processes using human glomerular mesangial cells (GMCs) in culture. METHODS: Proliferation of GMCs cultured with different concentrations of CNP-22 for 48 h was determined by a colorimetric assay using a tetrazolium salt. Monocyte chemoattractant protein-1 (MCP-1) and type IV collagen secretion into the culture media by GMCs in the presence or absence of CNP-22 were evaluated by ELISA. Expression of mRNA for natriuretic peptide receptor B (NPR-B), a specific receptor for CNP, was examined by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: CNP-22 (1-10 microM) inhibited serum-induced GMC growth in a dose-dependent manner. The amount of MCP-1 in the culture supernatant was increased approximately 2.4-fold by 5 microg/ml of lipopolysaccharide. This increase was inhibited by CNP-22 at 0.1-1 microM in a dose-dependent fashion. CNP-22 (10 microM) inhibited GMC type IV collagen secretion stimulated by 20 ng/ml of platelet-derived growth factor. Expression of NPR-B mRNA was confirmed in GMCs by RT-PCR. CONCLUSIONS: CNP suppresses GMC proliferation and MCP-1 and type IV collagen secretion by GMCs. It may have a therapeutic potential against human proliferative glomerular diseases, especially those with the involvement of monocytes.

Cell Division↗

Thrombin stimulates synthesis of type IV collagen and tissue inhibitor of metalloproteinases-1 by cultured human mesangial cells.

Glomerular accumulation of extracellular matrix (ECM) is the common pathologic feature following glomerular injury, and the alteration in the synthesis and degradation of ECM may be involved in the glomerular accumulation of ECM. Glomerular fibrin formation occurs in various forms of human and experimental glomerulonephritis, and it may play an important role in progressive glomerular injury. Thrombin, a multifunctional serine proteinase that is generated at the site of vascular injury, has central functions in hemostasis and it also shows various biologic effects. In this study, it is hypothesized that thrombin may alter the production and the degradation of type IV collagen, which is an important component of ECM in the glomeruli. Human mesangial cells (HMC) were cultured, and the levels of type IV collagen, tissue inhibitor of metalloproteinase-1 (TIMP-1), and matrix metalloproteinase-2 (MMP-2) in the culture supernatants were measured by enzyme immunoassay using specific antibodies. MMP-2 activity was also evaluated by zymography using polyacrylamide/ sodium dodecyl sulfate gel-containing gelatin. Thrombin increased the production of type IV collagen and TIMP-1 in a dose-and time-dependent manner, but it did not increase MMP-2. Thrombin also stimulated the gene expressions of the type IV collagen and TIMP-1 in HMC in a dose- and time-dependent manner. Thrombin treated with diisopropylfluorophosphate, a serine proteinase inhibitor, did not show any of these effects. Hirudin, a natural thrombin inhibitor, and anti-transforming growth factor-beta-neutralizing antibody inhibited the stimulating effect of thrombin. These findings suggest that thrombin may contribute to the excessive accumulation of ECM and progression of glomerulosclerosis through an increase of type IV collagen production and a decreased matrix degradation presumably via a transforming growth factor-beta-dependent mechanism.

Cells, Cultured↗

A case of Sjögren's syndrome associated with Sweet's syndrome.

We report a case of Sjögren's syndrome whose clinical course had been indolent until the patient presented with Sweet's syndrome (acute febrile neutrophilic dermatosis). This patient showed renal failure and renal tubular acidosis. Sweet's syndrome resolved within 3 weeks without corticosteroid therapy. Renal biopsy findings were consistent with interstitial nephritis. His renal manifestations responded to corticosteroid therapy and the renal function remained stable during 6 years follow-up without recurrence of Sweet's syndrome. Although close association of both syndromes is already known, in our case Sjögren's syndrome may have been exacerbated by occurrence of Sweet's syndrome.

Acute Kidney Injury↗

Thrombin stimulates production of transforming growth factor-beta by cultured human mesangial cells.

Fibrin formation within the glomeruli occurs in various forms of human and experimental glomerulonephritis and it may play an important role in progressive glomerular injury. Transforming growth factor-beta (TGF-beta) has been shown to participate in the glomerular accumulation of extracellular matrix in glomerulonephritis. We investigated whether thrombin, an important coagulation factor, could modulate the production of TGF-beta by cultured human mesangial cells (HMC). TGF-beta levels in the culture supernatants were measured by ELISA using a specific antibody. The TGF-beta concentration was significantly increased by incubation of HMC with thrombin in a time-dependent manner. The stimulating effect of thrombin on TGF-beta was inhibited by addition of hirudin (a natural thrombin inhibitor) and argatroban (a synthetic thrombin inhibitor). In addition DFP-inactivated thrombin, which has no enzymatic activity, did not stimulate TGF-beta production. A protein kinase C inhibitor (H7) and a tyrosine kinase inhibitor (herbimycin A) also inhibited thrombin induced TGF-beta production. These findings suggested that thrombin may modulate the synthesis of TGF-beta via protein kinase C- and tyrosine kinase-dependent mechanisms in cultured HMC. Thus thrombin may participate in the accumulation of extracellular matrix in glomeruli through the augmentation of TGF-beta production.

Cells, Cultured↗

Systemic lupus erythematosus associated with transverse myelitis and parkinsonian symptoms.

A 31-year old woman developed transverse myelitis after 10 years remission since she was first diagnosed as systemic lupus erythematosus. Although pulse methyl prednisolone resolved her myelitis, Parkinson-like symptoms developed subsequently after reduction of steroid. Treatments including apheresis did not improve her Parkinson-like symptoms such as rigidity, akinesia, impairment of speech and mask-like facial expression. Levodopa was effective as a symptomatic therapy. Orally administered cyclophosphamide eventually led her to remission and withdrawal from levodopa. Her clinical course and the absence of other possible causes prompted us to conclude that Parkinsonian symptoms as well as transverse myelitis may have developed as manifestations of central nervous system lupus.

Adult↗

Tissue factor pathway inhibitor production by human mesangial cells in culture.

Fibrin formation within the glomeruli has been observed in various forms of human and experimental glomerulonephritis and it may play an important role in progressive glomerular injury. Furthermore it has been hypothesized that glomerular fibrin deposition may occur through activation of either the intrinsic or extrinsic coagulation pathway. It has been demonstrated that a procoagulant activity (PCA) which is compatible with tissue factor is present in the glomeruli and becomes increased in human proliferative glomerulonephritis and in animal models of nephritis. Tissue factor pathway inhibitor (TFPI) regulates the extrinsic pathway of blood coagulation through its ability to inhibit tissue factor activity. TFPI is present in plasma and in platelets, and it is now thought to be produced mainly by endothelial cells. We examined whether human mesangial cells (HMC) could produce TFPI and attempted to clarify regulatory factors which affect TFPI production. Cultured HMC were used and TFPI in the cell supernatants was measured by ELISA using a specific antibody. Cultured HMC showed the production of TFPI. Immunoblot analysis revealed 40 kD protein of TFPI. The concentration of TFPI was significantly increased following the incubation with thrombin and heparin, including low molecular weight heparin, in a dose- and time-dependent manner. However, fetal calf serum, phorbol myristate acetate, lipopolysaccharide, IL-1 beta and tissue factor did not stimulate TFPI synthesis. Our data show that cultured HMC have the ability to produce TFPI which inhibits fibrin formation. It is possible that thrombin-induced enhancement of TFPI synthesis may be caused by the autoregulatory system of blood coagulation and that with heparin it may represent another anticoagulatory effect of heparin.

Anticoagulants↗

Deterioration of urinary findings after tonsil stimulation in patients with IgA nephropathy.

We studied whether urinary findings are affected by stimulation of tonsils in patients with IgA nephropathy. In 62 patients with IgA nephropathy and 20 patients with other renal diseases tonsils were stimulated by an ultra short wave for 10 min. Changes in amount of urinary protein, urinary sediment, blood leucocyte count, concentrations of serum IgA and serum secretory IgA were evaluated after tonsil stimulation. Forty of 62 patients with IgA nephropathy (65%) showed deterioration of urinary findings after the stimulation compared with 6 of 20 patients with other renal diseases (30%). The deterioration was significantly more frequent in IgA nephropathy than in other renal diseases (p <0.005). Previous episodes of gross hematuria following upper respiratory tract infections had occurred in 17 of 40 patients who showed deterioration of urinary findings after tonsil stimulation (43%) as against in 4 of 22 without deterioration (18%). The level of serum secretory IgA was higher in patients who showed deterioration of urinary findings after tonsil stimulation than in those who did not show it. Though tonsil stimulation increased blood leucocyte count it did not affect the concentrations of serum IgA or secretory IgA. It is concluded that tonsil stimulation often deteriorates urinary findings in patients with IgA nephropathy; therefore chronic tonsillitis may play a part in the pathogenesis of IgA nephropathy.

Adolescent↗

Membranoproliferative glomerulonephritis associated with hepatitis C virus infection responsive to interferon-alpha.

A 42-year-old man with hepatitis C virus infection, cryoglobulinemia, hypocomplementemia, and nephrotic syndrome is reported. The kidney biopsy showed membranoproliferative glomerulonephritis. The patient was treated with interferon-alpha for 2 months. After the treatment, serum hepatitis C virus RNA became negative and nephrotic syndrome remitted. Repeat biopsy of the kidney revealed an improvement in renal histology. This case confirms an association between hepatitis C virus infection and membranoproliferative glomerulonephritis and the usefulness of interferon-alpha for treatment.

Adult↗

Rapid detection of mycoplasma contamination in cell cultures by enzymatic detection of polymerase chain reaction (PCR) products.

Enzymatic detection of polymerase chain reaction (ED-PCR) was applied for rapid and easy identification of mycoplasmas from contaminated cell culture. This method was based on the capture of amplified products via biotin-streptavidine affinity and the detection of an incorporated hapten in amplified products with enzyme-linked antibody. Primers corresponding to common sequence of Mollicutes in 16S ribosomal RNA dominated gene was used. Nineteen of twenty Mollicutes so far reported as cell contaminants appeared positive by ED-PCR, whereas remaining one, Acholeplasma axanthum, appeared negative. Samples from sixty-two cell culture were tested for contamination of mycoplasmas by means of ED-PCR, cultivation, and electronmicroscopy. The results of ED-PCR were the same as those of cultivating method. The time required for all the detection process in ED-PCR was about 5 hr for 20 samples. We suggest that ED-PCR can be used in the rapid detection of mycoplasms from cell culture.

Animals↗

Hepatitis C virus infection and membranoproliferative glomerulonephritis in Japan.

The prevalence of hepatitis C virus (HCV) infection was determined in 146 adult patients with various types of glomerulonephritis and renal diseases monitored between 1990 and 1993. Serum HCV antibody (HCV Ab) was evaluated, and positive cases were tested for HCV RNA by polymerase chain reaction. HCV infection was present in 1 (1.7%) of 58 cases of immunoglobulin A nephropathy, 0 (0%) of 14 cases of lupus nephritis, 0 (0%) of 12 cases of minimal change nephrosis, and 0 (0%) of 28 cases of other renal diseases, which is similar to the 2% prevalence observed in healthy blood donors in Japan. In contrast, HCV Ab was observed in 2 (8.3%) of 24 cases of membranous nephropathy and 6 (60%) of 10 cases of membranoproliferative glomerulonephritis (MPGN) Type I. The prevalence of HCV infection in MPGN patients was significantly higher than the frequency of HCV infection observed in the other patients with renal diseases (P < 0.001). HCV RNA was present in all cases in which HCV Ab was present. The six patients with HCV-MPGN were similar to the four patients with idiopathic MPGN with respect to age, presence of nephrotic syndrome, and renal dysfunction, but had a higher incidence of liver dysfunction, cryoglobulinemia, rheumatoid factor, and hypocomplementemia (low C3). HCV infection is present in a large percentage of patients with MPGN in Japan and clinically may differ slightly from other cases of MPGN.

Adolescent↗

TGF-beta upregulates interleukin 6 production by rat glomerular epithelial cells in vitro.

BACKGROUND: Glomerular epithelial cells (GECs) play an important role in maintaining normal glomerular permselectivity in vivo. Recent in-vitro studies have suggested that GECs are able to secrete substances which may modulate glomerular injury. Interleukin 6 (IL-6) has been shown to be a potent mediator of glomerular injury. It is also known that IL-6 could be produced by various cells. METHODS: IL-6 production by rat GECs in culture was examined in this study. IL-6 bioactivity in conditioned medium collected from cultured GECs (GEC-CM) was measured using IL-6 dependent murine hybridoma cell line, namely B9 cells. IL-6 gene expression by GECs was analysed by reverse transcriptase polymerase chain reaction (RT-PCR). Effects of recombinant IL-6 on the proliferation of GECs and type IV collagen secretion by GECs were evaluated to examine the possible role of GECs derived IL-6. RESULTS: GEC-CM stimulated B9 cells growth in a dose dependent fashion. The mitogenic activity was inhibitable by anti-murine IL-6 antibody. De-novo synthesis of IL-6 was suggested by the demonstration of IL-6 mRNA by GECs using the RT-PCR. Secretion of IL-6 by GECs was increased by transforming growth factor beta but not by IL-1 beta. Recombinant murine IL-6 stimulated GECs growth and their type IV collagen secretion. CONCLUSIONS: These results indicate that rat GECs could produce IL-6 which may modulate glomerular inflammation and that IL-6 may function as an autocrine factor for GECs.

Animals↗

A case of anti-nuclear antibody negative systemic lupus erythematosus associated with penile ulcer.

We report here an old male patient with anti-nuclear antibody (ANA) negative systemic lupus erythematosus (SLE) with active renal disease and penile ulcer. He revealed nephrotic syndrome, malar rash and oral ulcer. SLE was discussed, however both ANA and anti-DNA antibody were persistently negative. A penile ulcer was also observed. He died of acute respiratory distress. Autopsy findings including onion skin lesion in the spleen and haematoxylin body in the kidney resulted in the final diagnosis of SLE. To our knowledge, association of penile ulcer with SLE has not yet been reported. Therefore, the present case is thought to be extremely unusual.

Antibodies, Antinuclear↗

Tissue factor production by cultured rat glomerular epithelial cells.

It is well known that fibrin deposition in Bowman's space in association with crescent formation may play an important role in progressive glomerular injury in crescentic glomerulonephritis. Recent reports describe the presence of a procoagulant activity (PCA) in the glomeruli and its increased expression in human and experimental nephritis. The cells that synthesize PCA have not yet been identified. We attempted to determine if glomerular epithelial cells (GEC), one of the prominent cell populations in the crescent, can produce PCA. The PCA of cultured rat GEC was measured by clotting and amidolytic assays. The cultured GEC yielded PCA with the characteristics of a tissue factor, and this PCA was stimulated by interleukin 1, tumour necrosis factor-alpha, and lipopolysaccharide. We concluded that GEC produce tissue-factor-like PCA and thereby may contribute to fibrin deposition, which, along with macrophage or monocyte infiltration, leads to crescent formation in crescentic glomerulonephritis.

Animals↗