35 results on '"Wigley, W Christian"'
Search Results
2. Dynamic Association of Proteasomal Machinery with the Centrosome
- Author
-
Wigley, W. Christian, Fabunmi, Rosalind P., Lee, Min Goo, Marino, Christopher R., Muallem, Shmuel, DeMartino, George N., and Thomas, Philip J.
- Published
- 1999
3. A Screen to Identify Cellular Modulators of Soluble Levels of an Amyotrophic Lateral Sclerosis (ALS)–Causing Mutant SOD1
- Author
-
Somalinga, Balajee R., Miller, Gregory A., Malik, Hiba T., Wigley, W. Christian, and Thomas, Philip J.
- Published
- 2011
- Full Text
- View/download PDF
4. A novel series of cysteine-dependent, allosteric inverse agonists of the nuclear receptor RORγt
- Author
-
Jiang, Xin, Dulubova, Irina, Reisman, Scott A., Hotema, Martha, Lee, Chun-Yue I., Liu, Liping, McCauley, Lyndsey, Trevino, Isaac, Ferguson, Deborah A., Eken, Yigitcan, Wilson, Angela K., Wigley, W. Christian, and Visnick, Melean
- Published
- 2020
- Full Text
- View/download PDF
5. Transmembrane domain of cystic fibrosis transmembrane conductance regulator: design, characterization, and secondary structure of synthetic peptides m1-m6
- Author
-
Wigley, W. Christian, Vijayakumar, S., Jones, Jeffrey D., Slaughter, Clive, and Thomas, Philip J.
- Subjects
Cystic fibrosis -- Research ,Peptides -- Research ,Proteins -- Structure ,Biological sciences ,Chemistry - Abstract
A study was conducted on the biophysical characterization of six peptides (m1-m6) representing the predicted amino-terminal membrane-spanning domain of cystic fibrosis transmembrane conductance regulator. The results indicate that the peptides exhibit an increase in Beta-sheet in trifluoroethanol, an inducer of alpha-helices. The findings also show that the possible functional role of m6 is manifested through a shift in secondary structure.
- Published
- 1998
6. Restriction fragment length polymorphism (RFLP) analysis provides evidence for a high degree of homology of mitochondrial DNAs from rat hepatomasVersus normal rat livers
- Author
-
Nakashima, Richard A., Li, Xin, Bayouth, J. Mark, and Wigley, W. Christian
- Published
- 1992
- Full Text
- View/download PDF
7. Natural mutagenesis study of the human steroid 5 alpha-reductase 2 isozyme
- Author
-
Wigley, W. Christian, Prihoda, James S., Mowszowicz, I., Mendonca, Berenice B., New, Maria I., Wilson, Jean D., and Russell, David W.
- Subjects
Isoenzymes -- Research ,Ligand binding (Biochemistry) -- Analysis ,Biological sciences ,Chemistry - Abstract
Natural mutagenesis study of the human 5alpha-reductase 2 isozyme reveals that specific amino acid residues are crucial for substrate and cofactor binding. The mutations are expressed in DNA transfected mammalian cells, and 13 out of the 22 mutations result in enzyme inactivation. The remaining mutations alter the substrate or cofactor binding. All mutations reduce the protein half-life and optimal pH.
- Published
- 1994
8. Hook2 contributes to aggresome formation
- Author
-
Yu Michelle, Didier Aaron, Hall Branden, Wigley W Christian, Szebenyi Györgyi, Thomas Philip, and Krämer Helmut
- Subjects
Cytology ,QH573-671 - Abstract
Abstract Background Aggresomes are pericentrosomal accumulations of misfolded proteins, chaperones and proteasomes. Their positioning near the centrosome, like that of other organelles, requires active, microtubule-dependent transport. Linker proteins that can associate with the motor protein dynein, organelles, and microtubules are thought to contribute to the active maintenance of the juxtanuclear localization of many membrane bound organelles and aggresomes. Hook proteins have been proposed to serve as adaptors for the association of cargos with dynein for transport on microtubules. Hook2 was shown to localize to the centrosome, bind centriolin, and contribute to centrosomal function. Results Here we show that overexpression of hook2 promotes the accumulation of the cystic fibrosis transmembrane regulator in aggresomes without altering its biochemical properties or its steady state level. A dominant negatively acting form of hook2 that lacks the centriolin binding C-terminal inhibits aggresome formation. Conclusion We propose that hook2 contributes to the establishment and maintenance of the pericentrosomal localization of aggresomes by promoting the microtubule-based delivery of protein aggregates to pericentriolar aggresomes.
- Published
- 2007
- Full Text
- View/download PDF
9. Effects of Bardoxolone Methyl on Hepatic Enzymes in Patients with Type 2 Diabetes Mellitus and Stage 4 CKD.
- Author
-
Lewis, James H., Jadoul, Michel, Block, Geoffrey A., Chin, Melanie P., Ferguson, Deborah A., Goldsberry, Angie, Meyer, Colin J., O'Grady, Megan, Pergola, Pablo E., Reisman, Scott A., Wigley, W. Christian, and Chertow, Glenn M.
- Subjects
ASPARTATE aminotransferase ,ALANINE aminotransferase ,TYPE 2 diabetes ,LIVER enzymes ,ENZYMES ,GLOMERULAR filtration rate ,CHRONIC kidney failure - Abstract
In a multinational placebo‐controlled phase III clinical trial in 2,185 patients with type 2 diabetes mellitus and stage 4 chronic kidney disease, treatment with the Nrf2 activator bardoxolone methyl increased estimated glomerular filtration rate, a measure of kidney function, but also resulted in increases in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transferase. These increases in liver enzyme level(s) were maximal after 4 weeks of treatment and reversible, trending back toward baseline through week 48. Total bilirubin concentrations did not increase, and no cases met Hy's Law criteria, although two subjects had ALT concentrations that exceeded 10 × the upper limit of the population reference range leading to discontinuation of treatment. Animal and cell culture experiments suggested that the increases in ALT and AST induced by bardoxolone methyl may be related to its pharmacological activity. Bardoxolone methyl significantly induced the mRNA expression of ALT and AST isoforms in cultured cells. Expression of ALT and AST isoforms in liver and kidney also positively correlated with Nrf2 status in mice. Overall, these data suggest that the increases in ALT and AST observed clinically were, at least in part, related to the pharmacological induction of aminotransferases via Nrf2 activation, rather than to any intrinsic form of hepatotoxicity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
10. Bardoxolone methyl analog attenuates proteinuria-induced tubular damage by modulating mitochondrial function.
- Author
-
Hajime Nagasu, Yuji Sogawa, Kengo Kidokoro, Seiji Itano, Toshiya Yamamoto, Minoru Satoh, Tamaki Sasaki, Takafumi Suzuki, Masayuki Yamamoto, Wigley, W. Christian, Proksch, Joel W., Meyer, Colin J., and Naoki Kashihara
- Published
- 2019
- Full Text
- View/download PDF
11. Cancer Cell Growth Is Differentially Affected by Constitutive Activation of NRF2 by KEAP1 Deletion and Pharmacological Activation of NRF2 by the Synthetic Triterpenoid, RTA 405.
- Author
-
Probst, Brandon L., McCauley, Lyndsey, Trevino, Isaac, Wigley, W. Christian, and Ferguson, Deborah A.
- Subjects
CANCER cell growth ,TRANSCRIPTION factors ,DELETION mutation ,TRITERPENOIDS ,ANTINEOPLASTIC agents ,TUMOR growth - Abstract
Synthetic triterpenoids are antioxidant inflammation modulators (AIMs) that exhibit broad anticancer activity. AIMs bind to KEAP1 and inhibit its ability to promote NRF2 degradation. As a result, NRF2 increases transcription of genes that restore redox balance and reduce inflammation. AIMs inhibit tumor growth and metastasis by increasing NRF2 activity in the tumor microenvironment and by modulating the activity of oncogenic signaling pathways, including NF-κB, in tumor cells. Accumulating evidence suggests that KEAP1 loss or mutation—which results in high levels of sustained NRF2 activity—may promote cancer growth and increase chemoresistance. Loss of KEAP1 also increases the levels of other oncogenic proteins, including IKKβ and BCL2. The apparent survival advantage provided to some tumor cells by loss of functional KEAP1 raises the question of whether pharmacological inhibition of KEAP1 could promote tumor growth. To address this issue, we characterized the basal levels of KEAP1 and NRF2 in a panel of human tumor cell lines and profiled the activity of an AIM, RTA 405. We found that in tumor cell lines with low or mutant KEAP1, and in Keap1
-/- murine embryonic fibroblasts, multiple KEAP1 targets including NRF2, IKKβ, and BCL2 were elevated. Keap1-/- murine embryonic fibroblasts also had higher rates of proliferation and colony formation than their wild-type counterparts. In cells with functional KEAP1, RTA 405 increased NRF2 levels, but not IKKβ or BCL2 levels, and did not increase cell proliferation or survival. Moreover, RTA 405 inhibited growth at similar concentrations in cells with different basal NRF2 activity levels and in cells with wild-type or mutant KRAS. Finally, pre-treatment with RTA 405 did not protect tumor cells from doxorubicin- or cisplatin-mediated growth inhibition. Collectively, these data demonstrate that pharmacological activation of NRF2 by AIMs is distinct from genetic activation and does not provide a growth or survival advantage to tumor cells. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
12. RTA 408, A Novel Synthetic Triterpenoid with Broad Anticancer and Anti-Inflammatory Activity.
- Author
-
Probst, Brandon L., Trevino, Isaac, McCauley, Lyndsey, Bumeister, Ron, Dulubova, Irina, Wigley, W. Christian, and Ferguson, Deborah A.
- Subjects
TRITERPENOIDS ,ANTINEOPLASTIC agents ,ANTI-inflammatory agents ,ANTIOXIDANTS ,METASTASIS ,GENE expression - Abstract
Semi-synthetic triterpenoids are antioxidant inflammation modulator (AIM) compounds that inhibit tumor cell growth and metastasis. Compounds in the AIM class bind to Keap1 and attenuate Nrf2 degradation. In the nucleus, Nrf2 increases antioxidant gene expression and reduces pro-inflammatory gene expression. By increasing Nrf2 activity, AIMs reduce reactive oxygen species and inflammation in the tumor microenvironment, which reverses tumor-mediated immune evasion and inhibits tumor growth and metastasis. AIMs also directly inhibit tumor cell growth by modulating oncogenic signaling pathways, such as IKKβ/NF-κB. Here, we characterized the in vitro antioxidant, anti-inflammatory, and anticancer activities of RTA 408, a novel AIM that is currently being evaluated in patients with advanced malignancies. At low concentrations (≤ 25 nM), RTA 408 activated Nrf2 and suppressed nitric oxide and pro-inflammatory cytokine levels in interferon-γ-stimulated RAW 264.7 macrophage cells. At higher concentrations, RTA 408 inhibited tumor cell growth (GI
50 = 260 ± 74 nM) and increased caspase activity in tumor cell lines, but not in normal primary human cells. Consistent with the direct effect of AIMs on IKKβ, RTA 408 inhibited NF-κB signaling and decreased cyclin D1 levels at the same concentrations that inhibited cell growth and induced apoptosis. RTA 408 also increased CDKN1A (p21) levels and JNK phosphorylation. The in vitro activity profile of RTA 408 is similar to that of bardoxolone methyl, which was well-tolerated by patients at doses that demonstrated target engagement. Taken together, these data support clinical evaluation of RTA 408 for cancer treatment. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
13. Bardoxolone methyl analogs RTA 405 and dh404 are well tolerated and exhibit efficacy in rodent models of Type 2 diabetes and obesity.
- Author
-
Chin, Melanie, Chun-Yue Ivy Lee, Jen-Chieh Chuang, Bumeister, Ron, Wigley, W. Christian, Sonis, Stephen T., Ward, Keith W., and Meyer, Colin
- Subjects
PEOPLE with diabetes ,KIDNEY diseases ,OBESITY ,TRITERPENOIDS ,BLOOD sugar ,DRUG tolerance ,ANIMAL models in research ,STREPTOZOTOCIN ,PATIENTS - Abstract
Bardoxolone methyl and related triterpenoids are well tolerated and efficacious in numerous animal models potentially relevant to patients with Type 2 diabetes and chronic kidney disease. These agents enhance glucose control and regulate lipid accumulation in rodent models of diabetes and obesity, and improve renal function, reduce inflammation, and prevent structural injury in models of renal disease. However, a recent study in Zucker diabetic fatty (ZDF) rats noted poor tolerability with the bardoxolone methyl analog RTA 405 within 1 mo after treatment initiation, although this study was confounded in part by the use of an impure RTA 405 batch. To investigate these discordant observations, the present studies were conducted to further characterize triterpenoids in rodent models of diabetes and obesity. A follow-up study was conducted in ZDF rats with two related triterpenoids (RTA 405 and dh404) for 1.5 mo. Consistent with previous rodent experience, and in contrast to the more recent ZDF report, ZDF rats administered RTA 405 or dh404 exhibited no adverse clinical signs, had laboratory values similar to controls, and exhibited no evidence of adverse liver or kidney histopathology. Additionally, RTA 405 was well tolerated in streptozotocin-induced Type 1 diabetic rats and high-fat-diet-induced obese mice. The present results are consistent with the overall published body of data obtained with triterpenoids and provide further evidence that these molecules are well tolerated without adverse effects on hepatobiliary or renal function in rodent models of diabetes and obesity. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
14. Synthesis, Chemical Reactivityas Michael Acceptors, and Biological Potency of Monocyclic Cyanoenones,Novel and Highly Potent Anti-inflammatory and Cytoprotective Agents(1).
- Author
-
Zheng, Suqing, Santosh Laxmi, Y. R., David, Emilie, Dinkova-Kostova, Albena T., Shiavoni, Katherine H., Ren, Yanqing, Zheng, Ying, Trevino, Isaac, Bumeister, Ronald, Ojima, Iwao, Wigley, W. Christian, Bliska, James B., Mierke, Dale F., and Honda, Tadashi
- Published
- 2012
- Full Text
- View/download PDF
15. Bardoxolone methyl (BARD) ameliorates ischemic AKI and increases expression of protective genes Nrf2, PPARγ, and HO-1.
- Author
-
Qing Qing Wu, Yanxia Wang, Senitko, Martin, Meyer, Colin, Wigley, W. Christian, Ferguson, Deborah A., Grossman, Eric, Jianlin Chen, Zhou, Xin J., Hartono, John, Winterberg, Pamela, Bo Chen, Agarwal, Anapam, and Lu, Christopher Y.
- Subjects
ISCHEMIA ,KIDNEY injuries ,CISPLATIN ,MESSENGER RNA ,ANTINEOPLASTIC agents - Abstract
Ischemic acute kidney injury (AKI) triggers expression of adaptive (protective) and maladaptive genes. Agents that increase expression of protective genes should provide a therapeutic benefit. We now report that bardoxolone methyl (BARD) ameliorates ischemic murine AKI as assessed by both renal function and pathology. BARD may exert its beneficial effect by increasing expression of genes previously shown to protect against ischemic AKI, NF-E2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor-γ (PPARγ), and heme oxygenase 1 (HO-1). Although we found that BARD alone or ischemia-reperfusion alone increased expression of these genes, the greatest increase occurred after the combination of both ischemia-reperfusion and BARD. BARD had a different mode of action than other agents that regulate PPARγ and Nrf2. Thus we report that BARD regulates PPARγ, not by acting as a ligand but by increasing the amount of PPARγ mRNA and protein. This should increase ligand-independent effects of PPARγ. Similarly, BARD increased Nrf2 mRNA; this increased Nrf2 protein by mechanisms in addition to the prolongation of Nrf2 protein half-life previously reported. Finally, we localized expression of these protective genes after ischemia and BARD treatment. Using double-immunofluorescence staining for CD31 and Nrf2 or PPARγ, we found increased Nrf2 and PPARγ on glomerular endothelia in the cortex; Nrf2 was also present on cortical peritubular capillaries. In contrast, HO-1 was localized to different cells, i.e., tubules and interstitial leukocytes. Although Nrf2-dependent increases in HO-1 have been described, our data suggest that BARD's effects on tubular and leukocyte HO-1 during ischemic AKI may be Nrf2 independent. We also found that BARD ameliorated cisplatin nephrotoxicity. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
16. Hsp90 Inhibition: A Promising Therapeutic Approach for ARSACS.
- Author
-
Nethisinghe, Suran, Abeti, Rosella, Kesavan, Maheswaran, Wigley, W. Christian, and Giunti, Paola
- Subjects
HEAT shock proteins ,THERAPEUTICS ,SCAFFOLD proteins ,CYTOPLASMIC filaments ,RESPONSE inhibition ,PROTEIN folding - Abstract
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurodegenerative disease caused by mutations in the SACS gene, encoding the 520 kDa modular protein sacsin, which comprises multiple functional sequence domains that suggest a role either as a scaffold in protein folding or in proteostasis. Cells from patients with ARSACS display a distinct phenotype including altered organisation of the intermediate filament cytoskeleton and a hyperfused mitochondrial network where mitochondrial respiration is compromised. Here, we used vimentin bundling as a biomarker of sacsin function to test the therapeutic potential of Hsp90 inhibition with the C-terminal-domain-targeted compound KU-32, which has demonstrated mitochondrial activity. This study shows that ARSACS patient cells have significantly increased vimentin bundling compared to control, and this was also present in ARSACS carriers despite them being asymptomatic. We found that KU-32 treatment significantly reduced vimentin bundling in carrier and patient cells. We also found that cells from patients with ARSACS were unable to maintain mitochondrial membrane potential upon challenge with mitotoxins, and that the electron transport chain function was restored upon KU-32 treatment. Our preliminary findings presented here suggest that targeting the heat-shock response by Hsp90 inhibition alleviates vimentin bundling and may represent a promising area for the development of therapeutics for ARSACS. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
17. A protein sequence that can encode native structure by disfavoring alternate conformations.
- Author
-
Wigley, W. Christian, Corboy, Michael J., Cutler, Todd D., Thibodeau, Patrick H., Oldan, Jorge, Lee, Min Goo, Rizo, Josep, Hunt, John F., and Thomas, Philip J.
- Subjects
- *
AMINO acid sequence , *MEMBRANE proteins - Abstract
The linear sequence of amino acids contains all the necessary information for a protein to fold into its unique three-dimensional structure. Native protein sequences are known to accomplish this by promoting the formation of stable, kinetically accessible structures. Here we describe a Pro residue in the center of the third transmembrane helix of the cystic fibrosis transmembrane conductance regulator that promotes folding by a distinct mechanism: disfavoring the formation of a misfolded structure. The generality of this mechanism is supported by genome-wide transmembrane sequence analyses. Furthermore, the results provide an explanation for the increased frequency of Pro residues in transmembrane α-helices. Incorporation by nature of such 'negative folding determinants', aimed at preventing the formation of off-pathway structures, represents an additional mechanism by which folding information is encoded within the evolved sequences of proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2002
18. Protein solubility and folding monitored in vivo by structural complementation of a genetic marker protein.
- Author
-
Wigley, W. Christian, Stidham, Rhesa D., Smith, Nathan M., Hunt, John F., and Thomas, Philip J.
- Subjects
- *
PROTEIN folding , *RECOMBINANT proteins , *GENETIC markers - Abstract
Protein misfolding is the basis of a number of human diseases and presents an obstacle to the production of soluble recombinant proteins. We present a general method to assess the solubility and folding of proteinsin vivo. The basis of this assay is structural complementation between the α- and ω-fragments of β-galactosidase (β-gal). Fusions of the α-fragment to the C terminus of target proteins with widely varying in vivo folding yield and/or solubility levels, including the Alzheimer's amyloid β (Aβ) peptide and a non-amyloidogenic mutant thereof, reveal an unambiguous correlation between β-gal activity and the solubility/folding of the target. Thus, structural complementation provides a means of monitoring protein solubility/misfolding in vivo, and should find utility in the screening for compounds that influence the pathological consequences of these processes. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
19. Natural mutagenesis study of the human steroid 5alpha-reductase 2 isozyme.
- Author
-
Wigley, W. Christian and Prihoda, James S.
- Subjects
- *
MUTAGENESIS , *ISOENZYMES - Abstract
Describes nine mutations in the 5alpha-reductase 2 gene in subjects with 5alpha-reductase deficiency. Biochemical consequences of the mutations; Information on the functional domains of the protein and pH characteristic of the isozyme.
- Published
- 1994
- Full Text
- View/download PDF
20. Detection of a progression-linked DNA restriction fragment in rat hepatoma cells probed with a hexokinase CDNA.
- Author
-
Wigley, W. Christian, Corson, Gary E., and Nakashima, Richard A.
- Published
- 1993
- Full Text
- View/download PDF
21. NRF2 as an Emerging Therapeutic Target.
- Author
-
Copple, Ian M., Dinkova-Kostova, Albena T., Kensler, Thomas W., Liby, Karen T., and Wigley, W. Christian
- Published
- 2017
- Full Text
- View/download PDF
22. ChemInform Abstract: Synthesis and Biological Evaluation of 1-[2-Cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]-4-ethynylimidazole. A Novel and Highly Potent Antiinflammatory and Cytoprotective Agent.
- Author
-
Honda, Tadashi, Dinkova-Kostava, Albena T., David, Emilie, Padegimas, Eric M., Sundararajan, Chitra, Visnick, Melean, Bumeister, Ron, and Wigley, W. Christian
- Published
- 2011
- Full Text
- View/download PDF
23. Characterization of novel small-molecule NRF2 activators: Structural and biochemical validation of stereospecific KEAP1 binding.
- Author
-
Huerta, Carlos, Jiang, Xin, Trevino, Isaac, Bender, Christopher F., Ferguson, Deborah A., Probst, Brandon, Swinger, Kerren K., Stoll, Vincent S., Thomas, Philip J., Dulubova, Irina, Visnick, Melean, and Wigley, W. Christian
- Subjects
- *
TRITERPENOIDS , *ANTIOXIDANTS , *DRUG development , *NF-kappa B , *STEREOSPECIFICITY , *CYSTEINE , *INFLAMMATION - Abstract
Background Semi-synthetic oleanane triterpenoid antioxidant inflammation modulators (tpAIMs) are small molecules that interact with KEAP1 cysteine residue 151 (C151) and activate NRF2. Exploration of the structure-activity relationship between the tpAIMs and KEAP1 is limited by the predominantly hydrocarbon nature of the oleanane triterpenoid pentacyclic ring structure. Therefore, we used novel, chemically-tractable, synthetic antioxidant inflammation modulators (sAIMs) to probe the stereoselectivity of the ligand-protein interaction. Methods We measured several parameters of NRF2 activation to assess the potency of sAIM enantiomers with natural (tpAIM-like) 4( S ),5( S ),10( R ) or unnatural 4( R ),5( R ),10( S ) configurations. Additionally, we determined the crystal structure of the KEAP1 BTB domain in complex with two different sAIMs. Results We found that the potencies of sAIM enantiomers in the natural configuration were similar to those of the tpAIM, RTA 405. Strikingly, sAIM enantiomers in the unnatural configuration were 10- to 40-fold less potent than their natural counterparts. Crystallographic studies of sAIMs in complex with the KEAP1 BTB domain demonstrated that these ligands form a covalent bond with C151 and revealed the presence of additional hydrogen bonds, Van der Waals interactions, and pi-stacking interactions. Conclusions Although KEAP1 C151 is required for NRF2 activation by tpAIMs and sAIMs, interactions with other KEAP1 residues are critical for the stereospecific recognition and potency of these ligands. General significance This work demonstrates that reversible cyanoenone Michael acceptors, such as the tpAIMs and sAIMs, can be specifically tuned to regulate redox sensitive cysteine residues on key signaling molecules, an approach with significant promise for innovative drug development. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
24. The synthetic triterpenoid, RTA 405, increases the glomerular filtration rate and reduces angiotensin II-induced contraction of glomerular mesangial cells.
- Author
-
Ding, Yanfeng, Stidham, Rhesa D, Bumeister, Ron, Trevino, Isaac, Winters, Ali, Sprouse, Marc, Ding, Min, Ferguson, Deborah A, Meyer, Colin J, Wigley, W Christian, and Ma, Rong
- Subjects
- *
TRITERPENOIDS , *GLOMERULAR filtration rate , *CHRONIC kidney failure , *TYPE 2 diabetes , *LABORATORY rats , *PLASMA flow - Abstract
Bardoxolone methyl, a synthetic triterpenoid, improves the estimated glomerular filtration rate (GFR) in patients with chronic kidney disease and type 2 diabetes. Since the contractile activity of mesangial cells may influence glomerular filtration, we evaluated the effect of the synthetic triterpenoid RTA 405, with structural similarity to bardoxolone methyl, on GFR in rats and on mesangial cell contractility in freshly isolated glomeruli. In rats, RTA 405 increased basal GFR, assessed by inulin clearance, and attenuated the angiotensin II-induced decline in GFR. RTA 405 increased the filtration fraction, but did not affect arterial blood pressure or renal plasma flow. Glomeruli from RTA 405-treated rats were resistant to angiotensin II-induced volume reduction ex vivo. In cultured mesangial cells, angiotensin II-stimulated contraction was attenuated by RTA 405, in a dose- and time-dependent fashion. Further, Nrf2-targeted gene transcription (regulates antioxidant, anti-inflammatory, and cytoprotective responses) in mesangial cells was associated with decreased basal and reduced angiotensin II-stimulated hydrogen peroxide and calcium ion levels. These mechanisms contribute to the GFR increase that occurs following treatment with RTA 405 in rats and may underlie the effect of bardoxolone methyl on the estimated GFR in patients. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
25. A Conserved GXXXG Motif in APH-1 Is Critical for Assembly and Activity of the γ-Secretase Complex.
- Author
-
Sheu-Fen Lee, Shah, Sanjiv, Cong Yu, Wigley, W. Christian, Harry Li, W. Christian, Myungsil Lim, W. Christian, Pedersen, Kia, Weiping Han, Kia, Thomas, Philip, Lundkvist, Johan, Yi-Heng Hao, Johan, and Gang Yu
- Subjects
- *
MEMBRANE proteins , *PRESENILINS , *CAENORHABDITIS elegans , *BIOCHEMISTRY , *BIOLOGY , *CHEMISTRY - Abstract
The multipass membrane protein APH-1, found in the γ-secretase complex together with presenilin, nicastrin, and PEN-2, is essential for Notch signaling in Caenorhabditis elegans embryos and is required for intramembrane proteolysis of Notch and β-amyloid precursor protein in mammalian and Drosophila cells. In C. elegans, a mutation of the conserved transmembrane Gly123 in APH-1 (mutant or28) leads to a notch/glp-1 loss-of-function phenotype. In this study, we show that the corresponding mutation in mammalian APH-1aL (G122D) disrupts the physical interaction of APH-1aL with hypoglycosylated immature nicastrin and the presenilin holoprotein as well as with mature nicastrin, presenilin, and PEN-2. The G122D mutation also reduced γ-secretase activity in intramembrane proteolysis of membrane-tethered Notch. Moreover, we found that the conserved transmembrane Gly122, Gly126, and Gly130 in the fourth transmembrane region of mammalian APH-1aL are part of the membrane helix-helix interaction GXXXG motif and are essential for the stable association of APH1aL with presenilin, nicastrin, and PEN-2. These findings suggest that APH-1 plays a GXX G-dependent scaffolding role in both the initial assembly and subsequent maturation and maintenance of the active γ-secretase complex. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
26. Effects of Bardoxolone Methyl on Hepatic Enzymes in Patients with Type 2 Diabetes Mellitus and Stage 4 CKD.
- Author
-
Lewis JH, Jadoul M, Block GA, Chin MP, Ferguson DA, Goldsberry A, Meyer CJ, O'Grady M, Pergola PE, Reisman SA, Wigley WC, and Chertow GM
- Subjects
- Aged, Alanine Transaminase genetics, Alanine Transaminase metabolism, Aspartate Aminotransferases genetics, Aspartate Aminotransferases metabolism, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 physiopathology, Female, Gene Expression Regulation, Enzymologic drug effects, Glomerular Filtration Rate drug effects, Glomerular Filtration Rate physiology, Humans, Kidney drug effects, Kidney physiopathology, Kidney Failure, Chronic blood, Kidney Failure, Chronic etiology, Kidney Failure, Chronic physiopathology, Liver drug effects, Liver enzymology, Male, Middle Aged, NF-E2-Related Factor 2 metabolism, Oleanolic Acid pharmacology, Oleanolic Acid therapeutic use, Alanine Transaminase blood, Aspartate Aminotransferases blood, Diabetes Mellitus, Type 2 complications, Kidney Failure, Chronic drug therapy, Oleanolic Acid analogs & derivatives
- Abstract
In a multinational placebo-controlled phase III clinical trial in 2,185 patients with type 2 diabetes mellitus and stage 4 chronic kidney disease, treatment with the Nrf2 activator bardoxolone methyl increased estimated glomerular filtration rate, a measure of kidney function, but also resulted in increases in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transferase. These increases in liver enzyme level(s) were maximal after 4 weeks of treatment and reversible, trending back toward baseline through week 48. Total bilirubin concentrations did not increase, and no cases met Hy's Law criteria, although two subjects had ALT concentrations that exceeded 10 × the upper limit of the population reference range leading to discontinuation of treatment. Animal and cell culture experiments suggested that the increases in ALT and AST induced by bardoxolone methyl may be related to its pharmacological activity. Bardoxolone methyl significantly induced the mRNA expression of ALT and AST isoforms in cultured cells. Expression of ALT and AST isoforms in liver and kidney also positively correlated with Nrf2 status in mice. Overall, these data suggest that the increases in ALT and AST observed clinically were, at least in part, related to the pharmacological induction of aminotransferases via Nrf2 activation, rather than to any intrinsic form of hepatotoxicity., (© 2020 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)
- Published
- 2021
- Full Text
- View/download PDF
27. Bardoxolone methyl analog attenuates proteinuria-induced tubular damage by modulating mitochondrial function.
- Author
-
Nagasu H, Sogawa Y, Kidokoro K, Itano S, Yamamoto T, Satoh M, Sasaki T, Suzuki T, Yamamoto M, Wigley WC, Proksch JW, Meyer CJ, and Kashihara N
- Subjects
- Animals, Cells, Cultured, Humans, Kidney Tubules, Proximal pathology, Male, Mice, Mice, Inbred ICR, Mitochondria physiology, NF-E2-Related Factor 2 physiology, Oleanolic Acid pharmacology, Reactive Oxygen Species metabolism, Kidney Tubules, Proximal drug effects, Mitochondria drug effects, Oleanolic Acid analogs & derivatives, Proteinuria complications
- Abstract
Multiple clinical studies have shown that bardoxolone methyl, a potent activator of nuclear factor erythroid 2-related factor 2 (Nrf2), is effective in increasing glomerular filtration rate in patients with chronic kidney disease. However, whether an Nrf2 activator can protect tubules from proteinuria-induced tubular damage via anti-inflammatory and antioxidative stress mechanisms is unknown. Using an Institute of Cancer Research-derived glomerulonephritis (ICGN) mouse model of nephrosis, we examined the effects of dihydro-CDDO-trifluoroethyl amide (dh404), a rodent-tolerable bardoxolone methyl analog, in protecting the tubulointerstitium; dh404 markedly suppressed tubular epithelial cell damage in the renal interstitium of ICGN mice. The tubular epithelial cells of ICGN mice showed a decrease in the size and number of mitochondria, as well as the breakdown of the crista structure, whereas the number and ultrastructure of mitochondria were maintained by the dh404 treatment. To further determine the effect of dh404 on mitochondrial function, we used human proximal tubular cells in vitro . Stimulation with albumin and free fatty acid increased mitochondrial reactive oxygen species (ROS). However, dh404 administration diminished mitochondrial ROS. Our data show that dh404 significantly reduced proteinuria-induced tubular cell mitochondrial damage, suggesting that improved redox balance and mitochondrial function and suppression of inflammation underlie the cytoprotective mechanism of Nrf2 activators, including bardoxolone methyl, in diabetic kidney disease.-Nagasu, H., Sogawa, Y., Kidokoro, K., Itano, S., Yamamoto, T., Satoh, M., Sasaki, T., Suzuki, T., Yamamoto, M., Wigley, W. C., Proksch, J. W., Meyer, C. J., Kashihara, N. Bardoxolone methyl analog attenuates proteinuria-induced tubular damage by modulating mitochondrial function.
- Published
- 2019
- Full Text
- View/download PDF
28. Synthesis, chemical reactivity as Michael acceptors, and biological potency of monocyclic cyanoenones, novel and highly potent anti-inflammatory and cytoprotective agents.
- Author
-
Zheng S, Santosh Laxmi YR, David E, Dinkova-Kostova AT, Shiavoni KH, Ren Y, Zheng Y, Trevino I, Bumeister R, Ojima I, Wigley WC, Bliska JB, Mierke DF, and Honda T
- Subjects
- Alkynes chemistry, Alkynes pharmacology, Amides chemistry, Amides pharmacology, Animals, Anti-Inflammatory Agents, Non-Steroidal chemistry, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Anticarcinogenic Agents chemistry, Anticarcinogenic Agents pharmacology, Apoptosis drug effects, Cell Line, Cell Line, Tumor, Cytoprotection, I-kappa B Kinase antagonists & inhibitors, Interleukin-1beta metabolism, Lipopolysaccharides pharmacology, Macrophages cytology, Macrophages drug effects, Macrophages metabolism, Mice, NAD(P)H Dehydrogenase (Quinone) biosynthesis, Nitric Oxide antagonists & inhibitors, Nitric Oxide biosynthesis, Nitriles chemistry, Nitriles pharmacology, Oleanolic Acid analogs & derivatives, Oleanolic Acid chemistry, Oleanolic Acid pharmacology, Phenanthrenes chemistry, Phenanthrenes pharmacology, Thiophenes chemistry, Thiophenes pharmacology, Tumor Necrosis Factor-alpha metabolism, Alkynes chemical synthesis, Anti-Inflammatory Agents, Non-Steroidal chemical synthesis, Anticarcinogenic Agents chemical synthesis, Nitriles chemical synthesis
- Abstract
Novel monocyclic cyanoenones examined to date display unique features regarding chemical reactivity as Michael acceptors and biological potency. Remarkably, in some biological assays, the simple structure is more potent than pentacyclic triterpenoids (e.g., CDDO and bardoxolone methyl) and tricycles (e.g., TBE-31). Among monocyclic cyanoenones, 1 is a highly reactive Michael acceptor with thiol nucleophiles. Furthermore, an important feature of 1 is that its Michael addition is reversible. For the inhibition of NO production, 1 shows the highest potency. Notably, its potency is about three times higher than CDDO, whose methyl ester (bardoxolone methyl) is presently in phase III clinical trials. For the induction of NQO1, 1 also demonstrated the highest potency. These results suggest that the reactivity of these Michael acceptors is closely related to their biological potency. Interestingly, in LPS-stimulated macrophages, 1 causes apoptosis and inhibits secretion of TNF-α and IL-1β with potencies that are higher than those of bardoxolone methyl and TBE-31.
- Published
- 2012
- Full Text
- View/download PDF
29. Bardoxolone methyl (BARD) ameliorates ischemic AKI and increases expression of protective genes Nrf2, PPARγ, and HO-1.
- Author
-
Wu QQ, Wang Y, Senitko M, Meyer C, Wigley WC, Ferguson DA, Grossman E, Chen J, Zhou XJ, Hartono J, Winterberg P, Chen B, Agarwal A, and Lu CY
- Subjects
- Acute Kidney Injury enzymology, Acute Kidney Injury etiology, Acute Kidney Injury genetics, Acute Kidney Injury pathology, Analysis of Variance, Animals, Capillaries drug effects, Capillaries enzymology, Cisplatin, Disease Models, Animal, Fluorescent Antibody Technique, Heme Oxygenase-1 genetics, Ischemia complications, Ischemia enzymology, Ischemia genetics, Ischemia pathology, Kidney blood supply, Kidney enzymology, Kidney pathology, Male, Membrane Proteins genetics, Mice, Mice, Inbred C57BL, NF-E2-Related Factor 2 genetics, Oleanolic Acid pharmacology, PPAR gamma genetics, RNA, Messenger metabolism, Time Factors, Up-Regulation, Acute Kidney Injury prevention & control, Heme Oxygenase-1 metabolism, Ischemia drug therapy, Kidney drug effects, Membrane Proteins metabolism, NF-E2-Related Factor 2 metabolism, Oleanolic Acid analogs & derivatives, PPAR gamma metabolism
- Abstract
Ischemic acute kidney injury (AKI) triggers expression of adaptive (protective) and maladaptive genes. Agents that increase expression of protective genes should provide a therapeutic benefit. We now report that bardoxolone methyl (BARD) ameliorates ischemic murine AKI as assessed by both renal function and pathology. BARD may exert its beneficial effect by increasing expression of genes previously shown to protect against ischemic AKI, NF-E2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor-γ (PPARγ), and heme oxygenase 1 (HO-1). Although we found that BARD alone or ischemia-reperfusion alone increased expression of these genes, the greatest increase occurred after the combination of both ischemia-reperfusion and BARD. BARD had a different mode of action than other agents that regulate PPARγ and Nrf2. Thus we report that BARD regulates PPARγ, not by acting as a ligand but by increasing the amount of PPARγ mRNA and protein. This should increase ligand-independent effects of PPARγ. Similarly, BARD increased Nrf2 mRNA; this increased Nrf2 protein by mechanisms in addition to the prolongation of Nrf2 protein half-life previously reported. Finally, we localized expression of these protective genes after ischemia and BARD treatment. Using double-immunofluorescence staining for CD31 and Nrf2 or PPARγ, we found increased Nrf2 and PPARγ on glomerular endothelia in the cortex; Nrf2 was also present on cortical peritubular capillaries. In contrast, HO-1 was localized to different cells, i.e., tubules and interstitial leukocytes. Although Nrf2-dependent increases in HO-1 have been described, our data suggest that BARD's effects on tubular and leukocyte HO-1 during ischemic AKI may be Nrf2 independent. We also found that BARD ameliorated cisplatin nephrotoxicity.
- Published
- 2011
- Full Text
- View/download PDF
30. Hook2 contributes to aggresome formation.
- Author
-
Szebenyi G, Wigley WC, Hall B, Didier A, Yu M, Thomas P, and Krämer H
- Subjects
- Animals, Cells, Cultured, Centrosome metabolism, Chlorocebus aethiops, Cystic Fibrosis Transmembrane Conductance Regulator genetics, Cystic Fibrosis Transmembrane Conductance Regulator metabolism, Humans, Inclusion Bodies chemistry, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins metabolism, Protein Folding, Protein Transport, Tissue Distribution, Transfection, Vero Cells, Inclusion Bodies metabolism, Microtubule-Associated Proteins physiology
- Abstract
Background: Aggresomes are pericentrosomal accumulations of misfolded proteins, chaperones and proteasomes. Their positioning near the centrosome, like that of other organelles, requires active, microtubule-dependent transport. Linker proteins that can associate with the motor protein dynein, organelles, and microtubules are thought to contribute to the active maintenance of the juxtanuclear localization of many membrane bound organelles and aggresomes. Hook proteins have been proposed to serve as adaptors for the association of cargos with dynein for transport on microtubules. Hook2 was shown to localize to the centrosome, bind centriolin, and contribute to centrosomal function., Results: Here we show that overexpression of hook2 promotes the accumulation of the cystic fibrosis transmembrane regulator in aggresomes without altering its biochemical properties or its steady state level. A dominant negatively acting form of hook2 that lacks the centriolin binding C-terminal inhibits aggresome formation., Conclusion: We propose that hook2 contributes to the establishment and maintenance of the pericentrosomal localization of aggresomes by promoting the microtubule-based delivery of protein aggregates to pericentriolar aggresomes.
- Published
- 2007
- Full Text
- View/download PDF
31. Aggresome formation.
- Author
-
Corboy MJ, Thomas PJ, and Wigley WC
- Subjects
- Cell Line, Humans, Centrosome enzymology, Nuclear Envelope enzymology, Proteasome Endopeptidase Complex metabolism, Protein Folding, Ubiquitin metabolism
- Abstract
Bulk protein degradation in the cell is catalyzed by the ubiquitin-proteasome system (UPS). At the heart of the UPS is the proteasome, a large multisubunit tightly-regulated protease. The UPS performs key functions in protein quality control by monitoring and eliminating potentially toxic misfolded or damaged proteins. When the capacity of this protease system is exceeded, misfolded protein substrates aggregate and are assembled through an active and regulated process to form an aggresome. Aggresomes are dynamic structures, formed as a general response to an overload of improperly folded proteins. Assembly of aggresomes occurs at the centrosome, a perinuclear structure that also serves as a site for the recruitment and concentration of components of the UPS, including the proteasome, its regulators, and other proteins typically involved in protein quality control. Thus, in addition to other cellular activities, the centrosome may play a central role in protein quality control, sitting at the crossroads of protein folding, degradation, and aggregation.
- Published
- 2005
- Full Text
- View/download PDF
32. A conserved GXXXG motif in APH-1 is critical for assembly and activity of the gamma-secretase complex.
- Author
-
Lee SF, Shah S, Yu C, Wigley WC, Li H, Lim M, Pedersen K, Han W, Thomas P, Lundkvist J, Hao YH, and Yu G
- Subjects
- Amino Acid Motifs, Amino Acid Sequence, Amyloid Precursor Protein Secretases, Animals, Aspartic Acid Endopeptidases, Cell Line, Endopeptidases genetics, Humans, Macromolecular Substances, Membrane Glycoproteins metabolism, Membrane Proteins genetics, Models, Biological, Molecular Sequence Data, Mutagenesis, Site-Directed, Peptide Hydrolases, Presenilin-1, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins metabolism, Sequence Homology, Amino Acid, Endopeptidases chemistry, Endopeptidases metabolism, Membrane Proteins chemistry, Membrane Proteins metabolism
- Abstract
The multipass membrane protein APH-1, found in the gamma-secretase complex together with presenilin, nicastrin, and PEN-2, is essential for Notch signaling in Caenorhabditis elegans embryos and is required for intramembrane proteolysis of Notch and beta-amyloid precursor protein in mammalian and Drosophila cells. In C. elegans, a mutation of the conserved transmembrane Gly123 in APH-1 (mutant or28) leads to a notch/glp-1 loss-of-function phenotype. In this study, we show that the corresponding mutation in mammalian APH-1aL (G122D) disrupts the physical interaction of APH-1aL with hypoglycosylated immature nicastrin and the presenilin holoprotein as well as with mature nicastrin, presenilin, and PEN-2. The G122D mutation also reduced gamma-secretase activity in intramembrane proteolysis of membrane-tethered Notch. Moreover, we found that the conserved transmembrane Gly122, Gly126, and Gly130 in the fourth transmembrane region of mammalian APH-1aL are part of the membrane helix-helix interaction GXXXG motif and are essential for the stable association of APH-1aL with presenilin, nicastrin, and PEN-2. These findings suggest that APH-1 plays a GXXXG-dependent scaffolding role in both the initial assembly and subsequent maturation and maintenance of the active gamma-secretase complex.
- Published
- 2004
- Full Text
- View/download PDF
33. Assessment of protein folding/solubility in live cells.
- Author
-
Stidham RD, Wigley WC, Hunt JF, and Thomas PJ
- Subjects
- Bacteriological Techniques, Carrier Proteins chemistry, Carrier Proteins genetics, Carrier Proteins isolation & purification, Escherichia coli enzymology, Escherichia coli genetics, Genetic Complementation Test, Humans, Maltose-Binding Proteins, Protein Folding, Recombinant Fusion Proteins genetics, Solubility, beta-Galactosidase chemistry, beta-Galactosidase genetics, beta-Galactosidase isolation & purification, Recombinant Fusion Proteins chemistry, Recombinant Fusion Proteins isolation & purification
- Published
- 2003
- Full Text
- View/download PDF
34. CFTR degradation and aggregation.
- Author
-
Corboy MJ, Thomas PJ, and Wigley WC
- Subjects
- Binding Sites, Cell Line, Centrosome metabolism, Cystic Fibrosis Transmembrane Conductance Regulator genetics, HeLa Cells, Humans, Immunoblotting, Immunohistochemistry methods, Models, Biological, Mutation, Plasmids metabolism, Protein Binding, Protein Folding, Protein Structure, Tertiary, Time Factors, Transfection, Tubulin metabolism, Cystic Fibrosis Transmembrane Conductance Regulator chemistry, Cystic Fibrosis Transmembrane Conductance Regulator metabolism, Microscopy, Fluorescence methods
- Published
- 2002
- Full Text
- View/download PDF
35. In vitro CFTR folding assays.
- Author
-
Stidham RD, Wigley WC, and Thomas PJ
- Subjects
- Cystic Fibrosis Transmembrane Conductance Regulator genetics, Humans, Kinetics, Protein Folding, Protein Structure, Tertiary, Temperature, Time Factors, Biochemistry methods, Cystic Fibrosis genetics, Cystic Fibrosis metabolism, Cystic Fibrosis Transmembrane Conductance Regulator chemistry
- Published
- 2002
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.