Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mixed lineage kinase 3 (MLK 3) (also called SPRK or PTK-1) is a recently described member of the family of the mixed lineage kinase subfamily of Ser/Thr protein kinases that interacts with mitogen-activated protein kinase pathways. In order to test the biological relevance and potential interaction of MLK 3 with protein kinase C-mediated signaling pathways, human MLK 3 was stably expressed in rat glomerular mesangial cells using a retroviral vector (LXSN) and the effects of phorbol myristoyl acetate (PMA) on DNA synthesis and osteopontin mRNA expression were examined. In control (vector-transfected) mesangial cells PMA increased [3H]-thymidine incorporation in a concentration-dependent manner. In mesangial cells stably expressing MLK 3, the PMA-induced increase in [3H]-thymidine incorporation was significantly reduced (> 50%). However, the PMA-induced increase in osteopontin mRNA was not affected by MLK 3 expression. To determine the mechanisms of these effects, activation of ERK2, JNK1 and p38 in response to PMA was examined in both vector and MLK 3 transfected cells. ERK2 activation was increased several fold by PMA in control cells but was attenuated significantly in MLK 3 expressing cells, suggesting that MLK 3 expression in mesangial cells can negatively regulate the ERK pathway. PMA had no significant effect on JNK and P38 activation, in either vector- or MLK 3-expressing cells. PD98059, a MEK inhibitor blocked PMA-induced DNA synthesis without affecting osteopontin expression. These results suggest that while protein kinase C activation increases cellular proliferation and osteopontin mRNA expression, over-expression of MLK 3 affects only the PKC-induced DNA synthesis, probably through inhibition of ERK. These results also indicate a novel mechanism of growth regulation by a member of the mixed-lineage kinase family that might have significant therapeutic implications in proliferative glomerulonephritis.
Mol Cell Biochem 2002 Dec
PMID:Mixed lineage kinase 3 inhibits phorbol myristoyl acetate-induced DNA synthesis but not osteopontin expression in rat mesangial cells. 1248 23

Macrophages are intimately involved in the development of immune-mediated inflammation, including glomerulonephritis. We have transduced primary cultures of macrophages to express IL-10 and tested the ability of these cells to control rat nephrotoxic nephritis (NTN), a model of human glomerulonephritis. Ad-IL-10-transduced bone-marrow-derived macrophages (BMDM) produced large amounts of IL-10 in culture, and their TNF-alpha production was decreased in response to interferon-gamma and LPS. Transduced macrophages were injected into the renal artery of rats, 6 h after the induction of NTN, where they localized efficiently to inflamed rat glomeruli. Delivery of IL-10-expressing macrophages to nephritic rats produced a marked reduction in albuminuria compared with unmodified NTN or injection of Ad-null-transduced BMDM. IL-10 treatment decreased the number of glomerular ED1- and ED3-positive cells, MHC class II expression, and the number of fibrinoid lesions. Interestingly, anti-inflammatory changes in the Ad-IL-10-injected kidney were mirrored by changes in the contralateral kidney. These results highlight that Ad-IL-10-transduced macrophages infiltrate inflamed glomeruli and reduce the severity of glomerular inflammation, emphasizing the value of local delivery of genetically modified macrophages in the manipulation of inflammatory disease.
Mol Ther 2002 Dec
PMID:Bone-marrow-derived macrophages genetically modified to produce IL-10 reduce injury in experimental glomerulonephritis. 1249 67

Numerous studies have demonstrated the involvement of the transforming growth factor (TGF) isoform beta(1) in the pathogenesis of renal fibroproliferative diseases. Although in vitro studies suggest that TGF-beta(2) is equally potent to TGF-beta(1) in terms of its antimitogenic and fibrogenic effects, much less is known about the regulation of TGF-beta(2) in renal diseases associated with glomerular cell hyperplasia and matrix expansion. Here we investigated the glomerular expression patterns of TGF-beta(2) and of the TGF-beta receptors I, II, and III during the course of rat anti-Thy1.1 nephritis (days 2, 6, 12, and 56), a model characterized by transient mesangial hypercellularity and extracellular matrix accumulation. TGF-beta(2) exhibited dynamic changes in expression. Immunohistochemical double-staining of renal sections revealed that most TGF-beta(2)-positive cells in control glomeruli were podocytes with few TGF-beta(2)-positive mesangial cells. This staining pattern could also be observed in human kidney. On day 6 of anti-Thy1.1 nephritis both TGF-beta(2) positive podocytes and mesangial cells were more abundant. By western blot analysis of isolated glomeruli from nephritic rats, protein expression of TGF-beta(2) was upregulated tenfold over control glomeruli, peaking on day 6 of the disease. In cultured rat mesangial cells we found that the TGF-beta(2) and TGF-beta(1) isoforms were equally potent in terms of nuclear accumulation of phosphorylated Smad 2/3, inhibition of DNA synthesis, and induction of beta(1)-integrin and type I collagen protein synthesis. Protein expression of the TGF-beta receptor I was not detected by immunohistochemistry in control glomeruli but was markedly induced in the mesangium on day 6 of nephritis. Mesangial staining for TGF-beta receptors II and III was detected in normal kidneys. Expression of TGF-beta receptor II was strongly enhanced on days 6 and 12 of disease, while TGF-beta receptor III was upregulated only on day 6. In summary, we report marked yet transient upregulation of TGF-beta(2) protein and of TGF-beta receptors I, II, and III in glomerular cells during anti-Thy1.1 nephritis. These results are in keeping with the notion that TGF-beta(2) and its receptors participate in the pathogenesis and/or resolution of this transient form of glomerulonephritis.
J Mol Med (Berl) 2003 Jan
PMID:Dynamic expression patterns of transforming growth factor-beta(2) and transforming growth factor-beta receptors in experimental glomerulonephritis. 1260 60

Immunoglobulins undergoing cold-dependent precipitation are known as cryoglobulins. A type I cryoglobulin after Brouet et al. from serum of a patient with severe cutaneous vasculitis and membranoproliferative glomerulonephritis was purified by reversible temperature-dependent precipitation and analyzed using FPLC, Western blotting and peptide sequencing. The isolated cryoglobulin consisted of a single complex of a molecular weight of above 210kDa observed under non-reducing conditions in SDS-polyacrylamide gel electrophoresis (PAGE). Under reducing conditions, this complex resolved into three bands, two of which were reminiscent of Ig heavy (HC) chains and one of Ig-light chains (LC). The FPLC-purified type I cryoglobulin showed reversible precipitation analyzed by spectrophotometry. Delineation of the peptides involved in complex formation by immunoblot analysis and peptide sequencing revealed IgG3-V(H)4/Igkappa-VkappaIII/JkappaII and IgG1/V(H)3 molecules with evidence of somatic mutation. Coomassie blue-staining suggested that molar amounts of the IgG3-heavy chain were much higher than that of the IgG1-heavy chain. Treatment with SDS and boiling did not disrupt the unusually high molecular weight Ig complex. Pre-treatment of the cryoglobulin in 6M guadinium hydrochloride followed by gel filtration chromatography suggested covalent association of the IgG3, IgG1 and Igkappa molecules. Therefore, it might be that the cryoglobulin was produced by a single plasma B cell clone which passed immunological check-points in terms of B cell selection in the bone marrow in the absence of allelic exclusion, class switching and affinity maturation by somatic mutation.
Mol Immunol 2003 Jun
PMID:Human IgG1/IgG3 cryoglobulin suggesting lack of allelic exclusion. 1274 7

Molecular analysis of pathologic changes in glomeruli requires methods allowing rapid and exact detection of alterations in gene expression. Here, we analyzed endothelin-1 (ET-1) mRNA expression in mesangiolytic glomeruli during the course of a rat and murine model of mesangioproliferative glomerulonephritis (GN). A novel method combining laser capture microdissection (LCM), which permits the precise removal of selected mesangiolytic glomeruli, with a highly sensitive real-time RT-PCR technique was used. Anti-Thy 1.1. GN was introduced in male Sprague-Dawley rats (1.0 mg/kg body weight of OX-7 IV) and Habu Snake Venom GN was introduced in C57BL6 mice (habu snake venom toxin 6 mg/kg body weight IV). The degree of mesangiolysis during both GNs was analyzed using a semiquantitative scoring system. Mesangiolytic glomeruli were microdissected at different days of the diseases (day 2, 6, and 12 in anti-Thy 1.1 GN and days 1, 3, 7, and 14 in Habu Snake Venom GN) and from normal control animals. After RNA extraction and cDNA synthesis, ET-1 gene expression was measured by real-time RT-PCR. In parallel, in anti-Thy 1.1. GN ET-1 mRNA expression was analyzed using semiquantitative nonradioactive in situ hybridization; ET-1 protein expression was investigated by immunohistochemistry. Mesangiolysis peaked at day 6 in anti-Thy1.1 GN and at day 1 in Habu Snake Venom GN. Mesangiolytic glomeruli were easily microdissected on cryostat sections in both models; quantification of mRNA with RT-PCR was reliable and reproducible. Glomerular ET-1 mRNA expression increased during the course of anti-Thy 1.1 GN and Habu Snake Venom GN peaked when mesangiolysis was most pronounced. This was seen by RT-PCR after glomerular LCM and by in situ hybridization; in parallel, glomerular ET-1 protein expression was increased. Combination of LCM and RT-PCR is a reliable method for quantification of localized gene expression in isolated renal structures. The above data argue for an important role of ET-1 in pathogenesis and/or repair of mesangiolysis in experimental mesangioproliferative GN.
Diagn Mol Pathol 2003 Jun
PMID:Laser capture microdissection and real-time PCR for analysis of glomerular endothelin-1 gene expression in mesangiolysis of rat anti-Thy 1.1 and murine Habu Snake Venom glomerulonephritis. 1276 16

The inhibition of specific transcription regulatory proteins is a novel approach to regulate gene expression. The transcriptional activities of DNA binding proteins can be inhibited by the use of double-stranded oligonucleotides (ODNs) that compete for binding to their specific target sequences in promoters and enhancers. Transfection of this cis-element double-stranded ODN, referred to as decoy ODN, has been reported to be a powerful tool that provides a new class of anti-gene strategies to gene therapy and permits examination of specific gene regulation. We have demonstrated the usefulness of this decoy ODN strategy in animal models of restenosis, myocardial infarction, glomerulonephritis and rheumatoid arthritis. However, one of the major limitations of decoy ODN technology is the rapid degradation of phosphodiester ODNs by intracellular nucleases. To date, several different types of double-stranded decoy ODNs have been developed to overcome this issue. Circular dumb-bell (CD) double-stranded decoy ODNs that were developed to resolve this issue have attracted a high level of interest. In this review, the applications of decoy ODN strategy and the advantages of modified CD double-stranded decoy ODNs will be discussed.
Curr Opin Mol Ther 2003 Apr
PMID:Development of novel decoy oligonucleotides: advantages of circular dumb-bell decoy. 1277 98

Selectins are carbohydrate-binding molecules that bind to fucosylated and sialylated glycoprotein ligands, and are found on endothelial cells, leukocytes and platelets. They are involved in trafficking of cells of the innate immune system, T lymphocytes and platelets. An absence of selectins or selectin ligands has serious consequences in mice or humans, leading to recurrent bacterial infections and persistent disease. Selectins are involved in constitutive lymphocyte homing, and in chronic and acute inflammation processes, including post-ischemic inflammation in muscle, kidney and heart, skin inflammation, atherosclerosis, glomerulonephritis and lupus erythematosus. Selectin-neutralizing monoclonal antibodies, recombinant soluble P-selectin glycoprotein ligand 1 and small-molecule inhibitors of selectins have been tested in clinical trials on patients with multiple trauma, cardiac indications and pediatric asthma, respectively. Anti-selectin antibodies have also been successfully used in preclinical models to deliver imaging contrast agents and therapeutics to sites of inflammation. Further improvements in the efficiency, availability, specificity and pharmacokinetics of selectin inhibitors, and specialized application routes and schedules, hold promise for therapeutic indications.
Trends Mol Med 2003 Jun
PMID:The role of selectins in inflammation and disease. 1282 15

Pentoxifylline (PTX) is a potent inhibitor of mesangial cell proliferation, but its underlying mechanism is poorly understood. Here, we demonstrate that in platelet-derived growth factor (PDGF)-stimulated mesangial cells, PTX causes G1 arrest by down-regulation of cyclin D1 expression, which subsequently attenuates Cdk4 activity. In vivo, PTX similarly reduces cyclin D1 expression in mesangial cells of rats with acute Thy1 glomerulonephritis. The mechanism by which PTX reduces cyclin D1 is also investigated. PTX blocks Akt but not phosphatidylinositol 3-kinase (PI3K) activation in response to PDGF and abrogates cyclin D1 induction by PI3K, suggesting an effect of PTX on Akt itself. Indeed, PTX is capable of blocking the membrane translocation of Akt, and enforced targeting of Akt to cell membrane prevents the inhibition of Akt and cyclin D1 by PTX. Because PTX is known to increase intracellular cAMP levels by inhibiting phosphodiesterase, the role of protein kinase A (PKA) in these events is investigated. The PKA antagonist N-[2-(4-bromocinnamylamino)ethyl]-5-isoquinoline (H89) abolishes cell proliferation effects of PTX and restores cyclin D1 expression as well as Akt membrane translocation and activation by PDGF, whereas dibutyryl cAMP and forskolin recapitulate the functions of PTX in mesangial cells. In conclusion, our results indicate that PTX, acting through PKA, interferes with PDGF signaling to Akt activation by blocking Akt membrane translocation, thereby inhibiting cyclin D1 expression and mesangial cell proliferation.
Mol Pharmacol 2003 Oct
PMID:Pentoxifylline inhibits platelet-derived growth factor-stimulated cyclin D1 expression in mesangial cells by blocking Akt membrane translocation. 1450 Jul 37

Retinoids, derivatives of vitamin A, inhibit mesangial cell proliferation, glomerular inflammation, and extracellular matrix deposition in acute anti-Thy1.1 glomerulonephritis (Thy-GN) of the rat. We examined a model, chronic mesangioproliferative Thy-GN (MoAb 1-22-3), which is more akin to human disease. Treatment started on day 23 when Thy-GN had already been established. Nonnephritic control and Thy-GN rats were treated orally for 67 days with vehicle or with two doses of either the retinoic acid receptor alpha-specific agonist AGN 195183 (RARalpha agonist) or the retinoid X receptor specific agonist AGN 194204 (RXR agonist). Doses of either the RARalpha or the RXR agonist significantly reduced albuminuria and normalized blood pressure during the course of treatment. The glomerulosclerosis index, glomerular cell and interstitial cell counts, and area of the interstitial space were significantly lower in nephritic rats treated with the RARalpha agonist or RXR agonist than with vehicle. The RARalpha and RXR agonist significantly reduced the infiltration of the glomerulus by macrophages. The increase in glomerular TGFbeta1 and prepro-ET(1) gene expression in vehicle-treated nephritic rats was significantly attenuated by RARalpha or RXR agonists. Glomerular expression of RXRalpha and RARalpha receptor mRNA was significantly greater in vehicle-treated nephritic rats than in nonnephritic controls. Treatment with RARalpha or RXR agonists tended to normalize retinoid-receptor gene expression. Our data indicate that both RARalpha agonists and RXR agonists reduce renal damage in rats with established chronic glomerulonephritis. Receptor-specific retinoids may provide a novel therapeutic approach for the treatment of chronic glomerulonephritis.
J Mol Med (Berl) 2004 Feb
PMID:Retinoic acid receptor alpha and retinoid X receptor specific agonists reduce renal injury in established chronic glomerulonephritis of the rat. 1471 50

Glomerular inflammation is associated with urinary mononuclear cells (UMC) in a number of diseases including IgA nephropathy and glomerulonephritis. We examined UMC from children with lupus nephritis for a number of years to characterize the types of mononuclear cells found in urine and to determine if they were associated with active lupus nephritis. Detailed analysis of UMC by cell counts and by flow cytometry showed that monocytes were the clearly dominant cell type. Evaluation of the smaller number of lymphocytes found in the urine of patients with active lupus nephritis demonstrated a strong predominance of CD8+ lymphocytes, in contrast to the normal CD4+/CD8+ ratio that is found in peripheral blood. The degree of proteinuria strongly correlated with the presence of UMC. The UMC counts decreased as their clinical condition improved as indicated by lower indices of flare. These observations suggest that UMC may be a valuable tool in detecting and monitoring disease activity in patients with severe lupus nephritis. More importantly, this study indicated that both monocytes and cytotoxic CD8+ T cells may play a role in pathogenesis of lupus nephritis.
Cell Mol Biol (Noisy-le-grand) 2003 Dec
PMID:Do urinary mononuclear cells reflect disease activity in lupus nephritis? 1498 6


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