Biomedical subjects

H Kawachi

Publications and source records attributed to H Kawachi.

At least 55 records · Page 3Linked to original sources

PubMed1998

Immunohistochemical identification of type B intercalated cells in the rat kidney by a monoclonal antibody.

We recently produced monoclonal antibodies using macrophagic cells derived from cultured rat glomeruli as the antigen. One of the antibodies, named OS-3, was found to detect a cell population scattered in collecting ducts of the rat kidney as well as macrophages in various tissues. The present study deals with the cellular and subcellular localization of immunoreactivities with OS-3 in the kidney and other organs of rats. Double immunostaining using OS-3 and an anti-serum against either calbindin or epidermal cytokeratin showed that OS-3-immunoreactive cells exist exclusively in both the connecting segment and cortical collecting duct, and differ from calbindin- or cytokeratin-positive epithelial cells. Ultrastructurally, OS-3-immunoreactive cells appeared spherical in shape with few cytoplasmic microprojections on the narrow apical surface. Their relatively dark cytoplasm contained numerous mitochondria and a developed tubulo-vesicular system. The intense immunoreactivity was selectively localized in the basolateral membrane exhibiting shallow but complicated infoldings. Distribution and ultrastructural properties of the OS-3-immunoreactive cells showed that they were type B intercalated cells, which are engaged in the regulation of the acid-base balance mainly by secreting HCO3-. Another positive staining with OS-3 was found in the macula densa and some epithelial cells of Bowman's capsule, the former monitoring Cl- concentrations in the urine. Immunoblotting of extracts from the rat kidney demonstrated a protein band immunoreactive to OS-3 at a molecular weight of 43 kDa. Aside from the kidney, a specific and intense immunoreactivity with OS-3 was also found in the epithelial cells of the pancreatic excretory duct and in the secretory cells of the salivary, pyloric and duodenal glands, all of which are HCO3- -secreting cells. These immunohistochemical findings imply that OS-3 is useful for the detection of type B intercalated cells and recognizes a functional molecule involved in the production/secretion of HCO3- or transport of Cl-.

Animals↗

PubMed1998

[A CR case of amylase-producing tumor treated by hyperthermochemotherapy].

A 64-year-old female who was diagnosed with an amylase-producing tumor of unknown origin was treated by hyperthermochemotherapy. The patient was admitted with a complaint of abdominal fullness due to ascites. Laboratory examination showed high levels of serum amylase and tumor markers, including CA15-3, CA 125 and CA 72-4. Laparotomy showed peritoneal dissemination with histological findings of adenocarcinoma of unknown origin. After laparotomy, she was given hyperthermia combined with chemotherapy using carboplatin (CBDCA), mitomycin C (MMC) and doxifluridine (5'-DFUR). Hyperthermia (13.56 MHz radiofrequency for 40-50 min) was performed a total of six times within one and a half months. The total doses of CBDCA and MMC were 450 mg and 24 mg, respectively, and 600 mg of 5'-DFUR was orally administered every day. By these combined treatments, ascites disappeared and serum levels of amylase and all tumor markers were decreased and normalized. MRI and echo examination also showed complete disappearance of peritoneal metastasis. Two and a half years after the treatment, the patient is alive without any evidence of recurrence, which suggests that this combined therapy is one of the useful modalities for peritoneal dissemination as well as an inoperable tumor itself.

Adenocarcinoma↗

PubMed1997

Gene analysis of an NADP-linked isocitrate dehydrogenase localized in peroxisomes of the n-alkane-assimilating yeast Candida tropicalis.

In n-alkane-utilizing yeast, Candida tropicalis, two NADP-linked isocitrate dehydrogenase (NADP-IDH) isozymes are present, one in mitochondria (Mt-NADP-IDH) and the other in peroxisomes (Ps-NADP-IDH). Here we report the isolation, sequencing, and expression of the gene encoding Ps-NADP-IDH (CtIDP2), distinct from the Mt-NADP-IDH gene (CtIDP1). Based on the N-terminal amino acid sequence of purified Ps-NADP-IDH, a cDNA fragment specific for Ps-NADP-IDH was obtained by the 5'-RACE method. Using this fragment as a probe, the genomic CtIDP2 gene was isolated. Nucleotide sequence analysis of CtIDP2 disclosed that the region encoding CtIdp2p had a length of 1233 bp, corresponding to 411 amino acid residues. The deduced N-terminal amino acid sequence matched the results obtained from the purified protein. When this CtIDP2 was expressed in Saccharomyces cerevisiae using the C. tropicalis isocitrate lyase gene promoter (UPR-ICL), high intracellular NADP-IDH activity was observed. Comparison of amino acid sequences and phylogenetic tree analysis with NADP-IDH enzymes from all reported eukaryotic sources revealed that mammalian mitochondrial NADP-IDHs formed a cluster, as did plant NADP-IDHs. CtIdp2p and other yeast NADP-IDHs were not included in these clusters and seemed to diverge at an early stage from all other enzymes of higher eukaryotes. Ps-NADP-IDH had no typical C-terminal peroxisomal targeting signal and no processing was demonstrated at the N-terminus. However, we could find a region near the N-terminus of the protein with high similarity to both the putative N-terminal peroxisomal targeting signal sequence of Fox3p of S. cerevisiae and an internal region of Pox4p of C. tropicalis. The results of northern blot analysis indicated that the biosynthesis of CtIdp2p was induced in a medium containing alkanes as a carbon source, where profuse proliferation of peroxisomes is observed.

Alkanes↗

PubMed1997

Creation of an In vivo cytosensor using engineered mesangial cells. Automatic sensing of glomerular inflammation controls transgene activity.

Automatic control over exogenous gene expression in response to the activity of disease is a crucial hurdle for gene transfer-based therapies. Towards achieving this goal, we created a "cytosensor" that perceives local inflammatory states and subsequently regulates foreign gene expression. alpha-Smooth muscle actin is known to be expressed in glomerular mesangial cells exclusively in pathologic situations. CArG box element, the crucial regulatory sequence of the alpha-smooth muscle actin promoter, was used as a sensor for glomerular inflammation. Rat mesangial cells were stably transfected with an expression plasmid that introduces a beta-galactosidase gene under the control of CArG box elements. In vitro, the established cells expressed beta-galactosidase exclusively after stimulation with serum. To examine whether the cells are able to automatically control transgene activity in vivo, serum-stimulated or unstimulated cells were transferred into normal rat glomeruli or glomeruli subjected to anti-Thy 1 glomerulonephritis. When stimulated cells were transferred into the normal glomeruli, beta-galactosidase expression was switched off in vivo within 3 d. In contrast, when unstimulated cells were transferred into the nephritic glomeruli, transgene expression was substantially induced. These data indicate the feasibility of using the CArG box element as a molecular sensor for glomerular injury. In the context of advanced forms of gene therapy, this approach provides a novel concept for automatic regulation of local transgene expression where the transgene is required to be activated during inflammation and deactivated when the inflammation has subsided.

Actins↗

PubMed1997

Characterization of the intron-containing citrate synthase gene from the alkanotrophic yeast Candida tropicalis: cloning and expression in Saccharomyces cerevisiae.

Citrate synthase, an essential enzyme of the tricarboxylic acid cycle in mitochondria, was purified from acetate-grown Candida tropicalis. Results from SDS-PAGE and gel filtration showed that this enzyme was a dimer composed of 45-kDa subunits. A citrate synthase cDNA fragment was amplified by the 5'-RACE method. Nucleotide sequence analysis of this cDNA fragment revealed that the deduced amino acid sequence contained an extended leader sequence which is suggested to be a mitochondrial targeting signal, as judged from helical wheel analysis. Using this cDNA probe, one genomic citrate synthase clone was isolated from a yeast lambdaEMBL3 library. The nucleotide sequence of the gene encoding C. tropicalis citrate synthase, CtCIT, revealed the presence of a 79-bp intron in the N-terminal region. Sequences essential as yeast splicing motifs were present in this intron. When the CtCIT gene including its intron was introduced into Saccharomyces cerevisiae using the promoter UPR-ICL, citrate synthase activity was highly induced, which strongly indicated that this intron was correctly spliced in S. cerevisiae.

Amino Acid Sequence↗

PubMed1997

Immunochemically distinct NADP-linked isocitrate dehydrogenase isozymes in mitochondria and peroxisomes of Candida tropicalis.

Although peroxisomal localization of NADP-linked isocitrate dehydrogenase (Idp) was first demonstrated in Candida tropicalis, the mitochondrial isozyme has not been found in this yeast. Here we report that the presence of mitochondrial Idp in the yeast was demonstrated by screening for its gene with a DNA probe containing conserved sequences of Idps from various organisms. The nucleotide sequence of the gene (CtIDP1) revealed a 1,290-bp open reading frame corresponding to a 430-amino-acid protein with a high similarity to previously reported Idps. Overexpression of CtIDP1 in Saccharomyces cerevisiae gave a high intracellular Idp activity, and the purified recombinant Idp was shown to be a homodimer with a subunit molecular mass of approximately 44 kDa, different from that of peroxisomal Idp (45 kDa) previously purified from C. tropicalis. Western blot analysis of the subcellular fractions from acetate-grown C. tropicalis with polyclonal antibodies raised against the recombinant CtIdp1 showed that the CtIdp1 in C. tropicalis was localized in mitochondria but not in peroxisomes. Similar levels of CtIDP1 mRNA and its protein product were detected in cells grown on glucose, acetate, and n-alkane, although a slight decrease was observed in n-alkane-grown cells. From these results, CtIdp1 was demonstrated to be mitochondrial Idp. The properties of mitochondrial Idp and peroxisomal Idp isozymes were proven to be similar, but they were immunochemically distinct, suggesting the presence of another gene responsible for peroxisomal Idp in C. tropicalis.

Amino Acid Sequence↗

PubMed1997

Suppressive effects of sairei-to on monoclonal antibody 1-22-3-induced glomerulonephritis: analysis of effective components.

The effects of traditional Chinese medicine (Sairei-to) on experimental glomerulonephritis induced in rats by monoclonal antibody (mAb) 1-22-3 injection was examined. The level of proteinuria in the Sairei-to-treated group was significantly lower than that in the PBS treated group. This suppressive effect was caused by the major component of Sairei-to, Syo-saiko-to but not by another component, Gorel-san. The suppressive effect of Syo-saiko-to was identified in its components (Bupleuri radix, Pinelliae tuber and Zingiberis rhizoma), but not in the other combined components (Ginseng radix and Zizyphi fructus). Further study revealed that the suppressive effects of the combined components were mainly derived from Bupleuri radix. It was demonstrated that the actual active ingredient is probably Saikosaponin-d. Light microscopy revealed that Sairei-to and its effective components suppressed the proliferation of mesangial cells and mesangial matrix expansion. Semiquantitative morphological studies of glomerular lesions on the eighth day showed that Syo-saiko-to and its combined components (Bupleuri radix, Zingiberis rhizoma and Pinelliae tuber) suppressed mesangial matrix expansion significantly compared with phosphate-buffered saline control groups (matrix score: 28.0 +/- 19.1 vs 102.3 +/- 14.1; 30.9 +/- 30.1 vs 102.3 +/- 14.1, P < 0.005, respectively). It was concluded that Saikosaponin-d, as well as Bupleuri radix, Syo-saiko-to and Sairei-to can suppress proteinuria and morphological changes in the rat glomerulonephritis model induced by mAb 1-22-3.

Animals↗

PubMed1997

Slit diaphragm-reactive nephritogenic MAb 5-1-6 alters expression of ZO-1 in rat podocytes.

Monoclonal antibody (MAb) 5-1-6 identifies a 51-kDa protein (p51) on rat podocyte foot processes and causes severe complement- and leukocyte-independent proteinuria when injected into rats. In the studies reported here, we used various immunohistological techniques to define the precise location of p51 and its relationship to ZO-1, a known component of the podocyte slit diaphragm in adult rat glomeruli. Our results demonstrate that p51 and ZO-1 lie close to each other on opposite sides of the podocyte plasma membrane at the point of insertion of the slit diaphragm: ZO-1 on the cytoplasmic face and p51 on the slit diaphragm and adjoining outer leaflet of the plasma membrane bordering the filtration slits. In addition to their geographic proximity, there appears to be a relationship between p51 and ZO-1. After MAb 5-1-6 injection, there was a progressive decline in stainable ZO-1 in the podocytes of heavily proteinuric rats. In addition, Western blot analysis of glomerular lysates showed that the decline in staining was due to a loss of immunoreactive ZO-1 rather than redistribution or diffusion of the protein. Simultaneously, the distribution of glomerular-bound MAb 5-1-6 became more clumped, apparently because of partial endocytosis into a lysosomal compartment, while the slit diaphragms remained morphologically intact. These findings suggest that MAb 5-1-6 alters the molecular composition of the slit diaphragm and thereby affects the glomerular permeability barrier.

Animals↗

PubMed1997

Roles of TGF-beta and latent TGF-beta-binding protein in glomerulosclerosis induced by two consecutive injections of monoclonal antibody 1-22-3 in rats.

The present study demonstrated the elevated synthesis and gene expressions of transforming growth factor beta (TGF-beta) or latent TGF-beta binding protein (LTBP) in an irreversible glomerulosclerosis rat model induced by two consecutive injections of monoclonal antibody (MoAb) 1-22-3. The rats were intravenously injected with 500 microg of MoAb 1-22-3 either once or twice at an interval of 2 weeks. The rats were sacrificed at 24 h, 1 week, 2 weeks or 16 weeks after the last injection. At 24 h, the mesangiolytic changes in the rats with two injections of MoAb 1-22-3 were similar to those in the rats with one injection. The glomerular matrix score in the rats with two injections was significantly higher than that in the rats with one injection at weeks 1, 2 or 16. An increased LTBP localization in the glomeruli of the rats at week 1 after either one or two injections was detected in the segmentally expanded mesangial matrix. Moreover, LTBP in the glomeruli of rats at week 1 after two injections appeared to be more strongly stained in the enlarged mesangial matrix than that in the rats after one injection. A TGF-beta bioassay using mink lung epithelial cells revealed that the total TGF-beta in the glomerular culture conditioned medium in the rats at week 1 after two injections was significantly larger than that in the rats after one injection. A Northern blotting analysis of the glomeruli showed that both the expressions of TGF-beta and LTBP mRNA in the rats after two injections were higher than those in the rats after one injection. These findings suggested that the elevated TGF-beta or LTBP may thus be related to the irreversible glomerulosclerosis that was induced by two injections of MoAb 1-22-3 into rats.

Animals↗

PubMed1997

Detailed analysis of phenotypes of macrophages infiltrating glomeruli in rat anti-Thy1 nephritis.

A phenotypic analysis of infiltrating macrophages in rat anti-Thy1 glomerulonephritis induced by monoclonal antibody (mAb) 1-22-3 was carried out using recently reported macrophage-specific mAbs. This was combined with a more detailed quantitative analysis, counting positive cells in isolated glomeruli, to obtain more information on the roles played by macrophages in glomerulonephritis. In normal glomeruli a small number of ED1- or OX-3(anti-Ia)-positive cells but almost no ED2-, TRPM-3- or Mar-3-positive cells were observed. ED1-positive cells increased from 2 h and peaked between days 3 and 7 after mAb injection. TRPM-3-positive cells increased from day 3 and peaked on day 7, later than ED1. The numbers of OX-3-positive cells changed in parallel with those of ED1-positive cells. Mar-3, which stained blood monocytes and ED2, which is an indicator oftissue-fixed resident macrophages, did not react with glomerular infiltrating macrophages. In a double staining study, about 40% of ED1- or OX-3-positive cells costained with TRPM-3 on day 3 and the percentage increased on day 7, but hardly any cells were positive for TRPM-3 alone. This results in two different phenotypes (ED1+,ED2-,OX-3+,Mar-3-, TRPM-3- and ED1+,ED2-,OX-3+,Mar-3-,TRPM-3+) of infiltrating macrophages. We conclude that in rat anti-Thy1 glomerulonephritis, monocytes/macrophages may infiltrate the mesangium, rapidly changing their phenotype (Mar-3+ to Mar-3-) and resulting in a gradual shift to TRPM-3-positive, activated macrophages.

Animals↗

PubMed1997

Quantification of apoptotic cells using isolated glomeruli.

In order to detect apoptotic cells in the kidney, the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method is used in tissue sections. But the number of apoptotic cells per glomerulus in several experimental models of nephritides is about 1 per single tissue section even at peak levels. In this study, we have reported that the TUNEL method and immunostaining of cell-specific markers to a whole isolated glomerulus in combination with laser scan microscopy are potentially useful methods for the analysis of cell turnover within glomeruli.

Animals↗

PubMed1997

[A case report of surgical treatment for aneurysm of the brachiocephalic artery associated with tracheal stenosis].

A 76-year-old woman, diagnosed with aneurysm of the brachiocephalic artery thirteen years ago, encountered tracheostenosis due to tracheal compression induced by an increase in size of the aneurysm. Complete aneurysmectomy with graft replacement under cardiopulmonary bypass failed to improve the bronchostenosis. This was attributed to tracheomalacia developed as a result of malatic tracheal cartilages. On day 14 post operation, external fixation of the trachea with an autografted costa relieved her condition markedly. Aneurysm of the brachiocephalic artery is rare and asymptomatical. As such, the present case report suggests that patients with such a aneurysm should be promptly operated to present both the risk of arterial rupture and unfavorable compression of adjacent organs.

Aged↗

PubMed1997

Candesartan prevents the progression of mesangioproliferative nephritis in rats.

We previously reported a new animal model of progressive glomerulonephritis induced by a single intravenous injection of the anti-Thy-1 monoclonal antibody MoAb 1-22-3 into uninephrectomized rats (Clin Exp Immunol 102: 181-185, 1995). We examined the effects of angiotensin II (Ang II) receptor antagonist (candesartan) on the clinical features and morphological lesions of this new model. By 10 weeks after induction of nephritis, untreated rats had developed hypertension, massive proteinuria, renal dysfunction, and severe glomerular injury, while uninephrectomized control rats had not. There was a significant increase in levels of glomerular protein and cortical mRNA for transforming growth factor-beta (TGF-beta) and type I and type III collagens in untreated nephritic rats. Ten week treatments with candesartan and hydralazine significantly reduced blood pressure (BP) to an equal extent. Candesartan, but not hydralazine, prevented proteinuria, normalized renal function, and ameliorated glomerular injury. Candesartan also reduced levels of glomerular protein and cortical mRNA for TGF-beta and type I and type III collagens, while hydralazine did not. These findings suggest that candesartan prevents progression to end-stage renal failure by modulating the effects of Ang II at least in part on the production of TGF-beta and type I and type III collagens, and not merely on systemic BP.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1996

Peroxisomal and mitochondrial carnitine acetyltransferases of the n-alkane-assimilating yeast Candida Tropicalis. Analysis of gene structure and translation products.

A genomic DNA clone encoding carnitine acetyltransferases (EC 2.3.1.7), localized in two subcellular organelles, peroxisomes and mitochondria of an n-alkane-assimilating yeast Candida tropicalis, was isolated from the yeast lambda EMBL library using a carnitine acetyltransferase CDNA probe. Nucleotide sequence analysis disclosed that the open reading frame was 1881 bp, corresponding to 627 amino acids with a molecular mass of 70760 Da. Comparison of the predicted amino acid sequence of the C. tropicalis enzyme with that of Saccharomyces cerevisiae mitochondrial matrix carnitine acetyltransferase revealed 46.3% identity. It was noticeable that the C. tropicalis enzymes had amino acid sequences similar to both proposed mitochondrial and peroxisomal targeting signals. When the C. tropicalis gene was expressed in S. cerevisiae using its own 5'-upstream region, a 12-fold increase in activity was observed. Western blot analysis revealed the presence of two major proteins whose sizes corresponded to the peroxisomal and mitochondrial proteins detected in C. tropicalis. This suggested that peroxisomal and mitochondrial carnitine acetyltransferases were encoded by one gene, as suggested for the S. cerevisiae enzyme. Furthermore, we have separated and purified these enzymes from peroxisomes and mitochondria of C. tropicalis, and analyzed the amino-terminal amino acid sequences of each. The amino-terminal sequence of the mitochondrial enzyme suggested that a signal sequence had been cleaved during translocation into mitochondria. Concerning the peroxisomal enzyme, the evidence obtained indicated that in vivo the translation was initiated at the second methionine of the open reading frame.

Alkanes↗

PubMed1996

Structural continuity of filtration slit (slit diaphragm) to plasma membrane of podocyte.

Murine monoclonal antibody 5-1-6 was reported to bind to the slit membrane and closely related structures in rat renal glomeruli; it induced heavy, reversible proteinuria and appeared to redistribute onto the plasma membrane of epithelial cells after binding at the original target sites. This phenomenon of antigenic movement has not been analyzed in detail to date. In addition to normal kidneys we also studied localization of the antigen recognized by monoclonal antibody 5-1-6 in protamine sulfate-perfused rat kidneys, in which slit diaphragms are known to be functionally modified. Isolated glomeruli as well as ultrathin kidney cryosections were labeled by the immunogold technique to clarify the relation between this antigen and the slit diaphragm. Sequential localization of injected monoclonal antibody was visualized using a post-embedding immunogold method in rats 2 hours to 12 days after injection of antibody. Ultrastructural immunogold labeling demonstrated that under normal conditions antigenic molecules were expressed mainly in the area beneath the slit diaphragms. Occasionally labeling was found at the base of the foot process, facing the glomerular basement membrane. After protamine sulfate treatment antigenic sites were dislocated due to the lifting and disruption of slit diaphragms, indicating that this antigen is associated with slit diaphragms. Injected antibody was localized at the filtration slits at 2 hours, and by 12 hours it had moved onto the apical plasma cell membrane of foot process. In addition, from 3 days onwards patch or cap-like formation on the plasma cell membrane of podocytes was seen. Possible shedding of antibody from podocyte cell surface membrane was occasionally encountered, but internalization of antibody was a minor event. Elution experiments in isolated glomeruli at day 3 indicated that antigen and antibody were both localized on the podocyte cell surface membrane, suggesting redistribution of immune complexes. In conclusion, filtration slits (slit diaphragms) and the apical membrane of foot process of podocytes demonstrate structural continuity, as revealed by the movement of the antigen recognized by monoclonal antibody 5-1-6 as antigen-antibody complexes.

Animals↗

PubMed1996

Individual expression of Candida tropicalis peroxisomal and mitochondrial carnitine acetyltransferase-encoding genes and subcellular localization of the products in Saccharomyces cerevisiae.

In an n-alkane assimilating yeast, Candida tropicalis, carnitine acetyltransferase (CAT; EC 2.3.1.7) was localized in both peroxisomes and mitochondria. Both CATs were encoded by one gene, CT-CAT, although the initiation sites of translation were suggested to be different. In the present study, the genes corresponding to the supposed C. tropicalis peroxisomal and mitochondrial CATs, which were truncated from the CT-CAT gene, were individually expressed in Saccharomyces cerevisiae, using the C. tropicalis isocitrate lyase promoter (UPR-ICL), which is inducible by oleic acid in concert with proliferation of peroxisomes in S. cerevisiae [Umemura, K., Atomi, H., Kanai, T., Teranishi, Y., Ueda, M., and Tanaka, A. (1995) Appl. Microbiol. Biotechnol. 43, 489-492]. The 71 kDa precursor of mitochondrial CAT, initiating at the first Met, was found to be processed to the mature size (66 kDa) in S. cerevisiae and immunoelectronmicroscopical observation revealed that this enzyme was localized in mitochondria. On the other hand, 68 kDa CAT, initiating at the second Met (residue No. 19), had no cleavable signal and was translocated into peroxisomes and cytosol, but not into mitochondria. The amino-terminal amino acid sequences of individually expressed CATs were identical to those of CATs isolated from alkane-grown C. tropicalis cells, respectively. These results demonstrated that only the 71 kDa protein yielded the 66 kDa protein and that peroxisomal and mitochondrial CATs arose from the difference in the initiation sites of translation.

Amino Acid Sequence↗

PubMed1995

Transfer of a mutated gene encoding active transforming growth factor-beta 1 suppresses mitogenesis and IL-1 response in the glomerulus.

Using in vivo gene transfer, we examined the anti-inflammatory potential of transforming growth factor-beta 1 (TGF-beta 1) in the renal glomerulus. TGF-beta 1 cDNA, modified to allow for secretion of the active form of TGF-beta 1, was introduced into cultured rat mesangial cells. The responses of the established transfectants were examined in culture. In vitro, the transduced mesangial cells showed a reduced mitogenic response to fetal calf serum and were insensitive to induction of matrix metalloproteinase-9 (MMP-9) by the proinflammatory cytokine IL-1 beta. To examine whether glomeruli which express active TGF-beta 1 in vivo are insensitive to these same stimuli, TGF-beta transfectants were transferred into normal rat glomeruli via renal artery injection. After 24 hours, isolated glomeruli containing transfectants exhibited TGF-beta bioactivity, a reduced mitogenic response, and repressed expression of MMP-9 in response to IL-1 beta. We further examined the responses of these chimeric glomeruli to an in vivo mitogenic stimulus by transferring TGF-beta transfectants into glomeruli of kidneys one day after the induction of anti-Thy-1 nephritis. The mitogenic activity of isolated glomeruli was examined four days after the cell injection. Compared to unmodified or mock cell-containing glomeruli, the in vivo mitogenic activity of glomeruli containing TGF-beta transfectants was significantly repressed. Furthermore, cellular outgrowth from nephritic glomeruli expressing active TGF-beta 1 was also suppressed ex vivo compared to controls. These data indicate that TGF-beta 1 inhibits mitogenesis and IL-1 response of the glomerulus and may, in part, act as a potential early suppressor of glomerular inflammation.

Animals↗

PubMed1995

Progressive renal lesions induced by administration of monoclonal antibody 1-22-3 to unilaterally nephrectomized rats.

A new animal model of progressive glomerulosclerosis was developed by administering a single i.v., injection of MoAb 1-22-3 to unilaterally nephrectomized rats. Renal morphological analysis revealed that glomerular lesions characterized by mesangial cell proliferation and mesangial matrix expansion were induced in about 95% of the glomeruli. Approximately 20% of the glomeruli of the unilaterally nephrectomized rats showed sclerosis or segmental sclerosis by week 6 after MoAb injection and crescent formation was observed in some glomeruli (ca 4%). Cellular infiltration was also noted in some parts of the interstitium. Increased expression of transforming growth factor-beta (TGF-beta) was observed in the unilaterally nephrectomized rats treated with MoAb 1-22-3, but we could not demonstrate pathological involvement of platelet-derived growth factor (PDGF), even though early-stage mesangial cell proliferation was observed. The mechanism of mesangial cell proliferation in this model remains to be elucidated. The relatively short period of time needed to induce the sclerotic changes in considered to be a great advantage of this model for clarifying the mechanisms involved in the chronic progression of mesangial proliferative glomerulonephritis.

Animals↗