Unilateral ureteral obstruction induces DNA repair by APE1

2016 ◽  
Vol 310 (8) ◽  
pp. F763-F776 ◽  
Author(s):  
Maria D. Aamann ◽  
Rikke Nørregaard ◽  
Marie Louise Vindvad Kristensen ◽  
Tinna Stevnsner ◽  
Jørgen Frøkiær
Keyword(s):  
Dna Repair ◽  
Protein Level ◽  
Ureteral Obstruction ◽  
Smooth Muscle Actin ◽  
Tissue Growth ◽  
Dna Lesions ◽  
Unilateral Ureteral Obstruction ◽  
Heme Oxygenase 1 ◽  
Type I ◽  
Repair Activity

Ureteral obstruction is associated with oxidative stress and the development of fibrosis of the kidney parenchyma. Apurinic/apyrimidinic endonuclease (APE1) is an essential DNA repair enzyme for repair of oxidative DNA lesions and regulates several transcription factors. The aim of the present study was to investigate whether APE1 is regulated by acute (24 h) and chronic (7 days) unilateral ureteral obstruction (UUO). APE1 was expressed in essentially all kidney cells with the strongest expression in proximal tubuli. After 24 h of UUO, APE1 mRNA was induced in the cortex, inner stripe of the outer medulla (ISOM), and inner medulla (IM). In contrast, the APE1 protein level was not regulated in the IM and ISOM and only slightly increased in the cortex. APE1 DNA repair activity was not significantly changed. A different pattern of regulation was observed after 7 days of UUO, with an increase of the APE1 mRNA level in the cortex but not in the ISOM and IM. The APE1 protein level in the cortex, ISOM, and IM increased significantly. Importantly, we observed a significant increase in APE1 DNA repair activity in the cortex and IM. To confirm our model, we investigated heme oxygenase-1, collagen type I, fibronectin I, and α-smooth muscle actin levels. In vitro, we found the transcriptional regulatory activity of APE1 to be involved in the upregulation of the profibrotic factor connective tissue growth factor. In summary, APE1 is regulated at different levels after acute and chronic UUO. Thus, our results suggest that DNA repair activity is regulated in response to progressive (7 days) obstruction and that APE1 potentially could play a role in the development of fibrosis in kidney disease.

scholarly journals Bone Morphogenetic Protein-2 Antagonizes Renal Interstitial Fibrosis by Promoting Catabolism of Type I Transforming Growth Factor-β Receptors

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 727-740 ◽  
Author(s):  
Yu-Lin Yang ◽  
Yi-Shiuan Liu ◽  
Lea-Yea Chuang ◽  
Jinn-Yuh Guh ◽  
Tao-Chen Lee ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Ureteral Obstruction ◽  
Time Course ◽  
Transforming Growth Factor ◽  
Interstitial Fibrosis ◽  
Unilateral Ureteral Obstruction ◽  
Bone Morphogenetic Protein 2 ◽  
Type I ◽  
Morphogenetic Protein ◽  
Tgf Β1

TGF-β is a therapeutic target for renal fibrosis. Scientists have long sought ways to antagonize TGF-β to ameliorate diabetic nephropathy. Bone morphogenetic protein (BMP-2) is a member of the TGF-β superfamily and is highly regulated in the kidney. Thus, the role of BMP-2 was investigated in NRK-49F cells (rat fibroblasts). We showed that TGF-β1 induces an increase in fibronectin. Treatment with exogenous BMP-2 or pCMV-BMP-2 significantly reversed the TGF-β1-induced increase in fibronectin concomitant with a significant decrease in type I TGF-β receptors (TGF-β RI). Moreover, BMP-2 significantly shortened the half-life of TGF-β RI. These results are related to proteosomal activation because MG132, a proteasome inhibitor, abolished BMP-2-mediated degradation of TGF-β RI. This was confirmed because BMP-2 time course dependently enhanced the ubiquitination level of TGF-β RI. In addition, Smads would seem to be involved in the interaction of BMP-2 and TGF-β. We demonstrated that BMP-2 significantly reversed the TGF-β1-induced increase in pSmad2/3 and reversed the TGF-β1-induced decrease in inhibitory Smad7. Most importantly, Smad7 small interfering RNA abolished the BMP-2-induced decrease in TGF-β RI. We evaluated the clinical efficacy of BMP-2 using unilateral ureteral obstruction rats. BMP-2 was administered ip for 7 d. In the unilateral ureteral obstruction kidneys, interstitial fibrosis was prominent. However, treatment with BMP-2 dramatically reduced Masson’s trichrome staining (collagen) in the interstitial and tubular areas of the kidneys concomitantly with a reduction in TGF-β RI. These results suggest that BMP-2 acts as a novel fibrosis antagonizing cytokine partly by down-regulating TGF-β RI and Smads. Bone morphogenetic protein-2 can antagonize TGF-β-inducing cellular fibrosis by intervening post-receptors signaling, thus disclosing an application of therapeutical potential against fibrosis disorders.

scholarly journals Deletion of Akt1 Promotes Kidney Fibrosis in a Murine Model of Unilateral Ureteral Obstruction

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Il Young Kim ◽  
Min Young Lee ◽  
Mi Wha Park ◽  
Eun Young Seong ◽  
Dong Won Lee ◽  
...  
Keyword(s):  
Murine Model ◽  
Ureteral Obstruction ◽  
Renal Fibrosis ◽  
Unilateral Ureteral Obstruction ◽  
Type I ◽  
Wild Type ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Hk2 Cells

We investigated the role of Akt1, one of the three isoforms of Akt, in renal fibrosis using the murine model of unilateral ureteral obstruction (UUO). We subjected wild type and Akt1−/− mice to UUO. The Akt1 gene was silenced in vitro using short hairpin RNA delivered via a lentiviral vector in human proximal tubular cells (HK2 cells) and kidney fibroblasts (NRK-49F cells). The obstructive kidneys of Akt1−/− mice showed more severe tubulointerstitial fibrosis than those of wild type mice. The expression of fibronectin and type I collagen was significantly increased in obstructed kidneys of Akt1−/− mice compared to those of wild type mice. The important finding was that the expression of transforming growth factor β1 (TGFβ1) was significantly increased in the Akt1−/− mice compared to the wild type mice. The knockdown of Akt1 enhanced the expression of TGFβ1 in HK2 cells. Interestingly, the upregulation of TGFβ1 due to genetic knockdown of Akt1 was associated with activation of signal transducer and activator of transcript 3 (STAT3) independently of the Smad pathway in NRK-49F and HK2 cells. Immunohistochemical staining also showed that expression of phosphorylated STAT3 was more increased in Akt1−/− mice than in wild type mice after UUO. Additionally, the deletion of Akt1 led to apoptosis of the renal tubular cells in both in vivo and in vitro studies. Conclusively, these results suggest that the deletion of Akt1 may contribute to renal fibrosis via induction of the TGFβ1/STAT3 pathway in a murine model of UUO.

scholarly journals A novel cell-permeable antioxidant peptide decreases renal tubular apoptosis and damage in unilateral ureteral obstruction

2008 ◽  
Vol 295 (5) ◽  
pp. F1545-F1553 ◽  
Author(s):  
Yasunori Mizuguchi ◽  
Jie Chen ◽  
Surya V. Seshan ◽  
Dix P. Poppas ◽  
Hazel H. Szeto ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
P38 Mapk ◽  
Ureteral Obstruction ◽  
Renal Damage ◽  
Transforming Growth Factor ◽  
Unilateral Ureteral Obstruction ◽  
Heme Oxygenase 1 ◽  
Myocardial Infraction

Unilateral ureteral obstruction (UUO) is characterized by decreases in renal function, increased interstitial fibrosis, tubular apoptosis, and cellular infiltration. It has been suggested that inhibition of tubular apoptosis may protect against renal damage in obstruction. We have recently developed a series of peptides which are concentrated in the inner mitochondrial membrane and prevent cell death. These peptides are also active in vivo, in myocardial infraction, ischemic brain injury, and amyotrophic lateral sclerosis models. We therefore used SS-31, a prototype of these peptides, and assessed its effects on renal damage and oxidative stress in a 14-day obstruction model. SS-31 (1 or 3 mg/kg) or saline was given 1 day before and throughout the 14 days of obstruction. Kidneys were harvested and assessed for apoptosis (terminal transferase-dUTP-nick-end labeling, caspase 3 expression), fibrosis (trichrome staining), macrophage infiltration, fibroblast expression (immunoperoxidase), and oxidative damage (8-OH deoxyguanosine and heme oxygenase-1 expression), cytokines, and signaling pathways (transforming growth factor-β, CCR-1, p38-MAPK, NF-κB). SS-31 significantly attenuated the effects of obstruction on all aspects of renal damage which were examined, with both the 1 and 3 mg/kg doses showing efficacy. We noted increased oxidative stress in obstruction, which was also attenuated by SS-31 treatment. Signaling via NF-κB and p38 MAPK pathways were both affected by SS-31 treatment. This study provides a proof of concept that peptides which protect mitochondria in vitro can provide protection from renal damage in a UUO model. The mechanism by which protection is afforded requires further studies both in vitro and in vivo.

scholarly journals Dianhydrogalactitol synergizes with topoisomerase poisons to overcome DNA repair activity in tumor cells

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Beibei Zhai ◽  
Yue Li ◽  
Sudha Sravanti Kotapalli ◽  
Jeffrey Bacha ◽  
Dennis Brown ◽  
...  
Keyword(s):  
Dna Repair ◽  
Topoisomerase I ◽  
Topoisomerase Ii ◽  
Dna Lesions ◽  
Γh2ax Foci ◽  
Topoisomerase Poisons ◽  
Repair Activity ◽  
Functional Dna ◽  
Combination Regimens ◽  
The Impact

Abstract 1,2:5,6-Dianhydrogalactitol (DAG) is a bi-functional DNA-targeting agent currently in phase II clinical trial for treatment of temozolomide-resistant glioblastoma (GBM). In the present study, we investigated the cytotoxic activity of DAG alone or in combination with common chemotherapy agents in GBM and prostate cancer (PCa) cells, and determined the impact of DNA repair pathways on DAG-induced cytotoxicity. We found that DAG produced replication-dependent DNA lesions decorated with RPA32, RAD51, and γH2AX foci. DAG-induced cytotoxicity was unaffected by MLH1, MSH2, and DNA-PK expression, but was enhanced by knockdown of BRCA1. Acting in S phase, DAG displayed selective synergy with topoisomerase I (camptothecin and irinotecan) and topoisomerase II (etoposide) poisons in GBM, PCa, and lung cancer cells with no synergy observed for docetaxel. Importantly, DAG combined with irinotecan treatment enhanced tumor responses and prolonged survival of tumor-bearing mice. This work provides mechanistic insight into DAG cytotoxicity in GBM and PCa cells and offers a rational for exploring combination regimens with topoisomerase I/II poisons in future clinical trials.

scholarly journals Role of the cytoskeleton in the development of a hypofibrotic cardiac fibroblast phenotype in volume overload heart failure

2019 ◽  
Vol 316 (3) ◽  
pp. H596-H608 ◽  
Author(s):  
Rachel C. Childers ◽  
Ian Sunyecz ◽  
T. Aaron West ◽  
Mary J. Cismowski ◽  
Pamela A. Lucchesi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Pressure Overload ◽  
Volume Overload ◽  
Transforming Growth Factor Β ◽  
Collagen Type I ◽  
Tissue Growth ◽  
Type I

Hemodynamic load regulates cardiac remodeling. In contrast to pressure overload (increased afterload), hearts subjected to volume overload (VO; preload) undergo a distinct pattern of eccentric remodeling, chamber dilation, and decreased extracellular matrix content. Critical profibrotic roles of cardiac fibroblasts (CFs) in postinfarct remodeling and in response to pressure overload have been well established. Little is known about the CF phenotype in response to VO. The present study characterized the phenotype of primary cultures of CFs isolated from hearts subjected to 4 wk of VO induced by an aortocaval fistula. Compared with CFs isolated from sham hearts, VO CFs displayed a “hypofibrotic” phenotype, characterized by a ~50% decrease in the profibrotic phenotypic markers α-smooth muscle actin, connective tissue growth factor, and collagen type I, despite increased levels of profibrotic transforming growth factor-β1 and an intact canonical transforming growth factor-β signaling pathway. Actin filament dynamics were characterized, which regulate the CF phenotype in response to biomechanical signals. Actin polymerization was determined by the relative amounts of G-actin monomers versus F-actin. Compared with sham CFs, VO CFs displayed ~78% less F-actin and an increased G-actin-to-F-actin ratio (G/F ratio). In sham CFs, treatment with the Rho kinase inhibitor Y-27632 to increase the G/F ratio resulted in recapitulation of the hypofibrotic CF phenotype observed in VO CFs. Conversely, treatment of VO CFs with jasplakinolide to decrease the G/F ratio restored a more profibrotic response (>2.5-fold increase in α-smooth muscle actin, connective tissue growth factor, and collagen type I). NEW & NOTEWORTHY The present study is the first to describe a “hypofibrotic” phenotype of cardiac fibroblasts isolated from a volume overload model. Our results suggest that biomechanical regulation of actin microfilament stability and assembly is a critical mediator of cardiac fibroblast phenotypic modulation.

scholarly journals HuangQi Decoction Ameliorates Renal Fibrosis via TGF-β/Smad Signaling Pathway In Vivo and In Vitro

2016 ◽  
Vol 38 (5) ◽  
pp. 1761-1774 ◽  
Author(s):  
Jie Zhao ◽  
Li Wang ◽  
Ai-li Cao ◽  
Ming-Qian Jiang ◽  
Xia Chen ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Ureteral Obstruction ◽  
Interstitial Fibrosis ◽  
Unilateral Ureteral Obstruction ◽  
Type I ◽  
Renal Interstitial Fibrosis ◽  
Smad Signaling ◽  
Smad Signaling Pathway ◽  
Tgf Β1

Objective: Traditional Chinese Medicine compound HuangQi decoction is widely used in clinical treatment of chronic kidney disease, but its role on renal interstitial fibrosis and the underlying mechanism remains unclear. The aim of this study is to investigate the effect of HuangQi decoction on renal interstitial fibrosis and its association with the TGF-β/Smad signaling pathway Methods: A total of 120 C57/BL mice were randomly divided into six groups: sham group, sham plus high-dose HuangQi decoction (1.08g/kg) group, unilateral ureteral obstruction (UUO) model group, and UUO model plus low to high doses of HuangQi decoction (0.12g/kg, 0.36g/kg and 1.08g/kg respectively) groups. Animals were sacrificed 14 days after the administration and ipsilateral kidney tissue was sampled for pathologic examinations. Immunohistochemistry, PCR and western blot were used to detect the expressions of related molecules in the TGF-β/Smad signaling pathway. TGF-β1 was used in in vitro experiments to induce human kidney proximal tubule epithelial cells (HK2). Results: HuangQi decoction improved ipsilateral kidney fibrosis in UUO mice and downregulated the expressions of TGF-β1, TβRI, TβRII, Smad4, Smad2/3, P-Smad2/3, α-SMA, collagen type I, III and IV in a dose-dependent manner while upregulated the expression of Smad7 in the same fashion. Similar results were found in in vitro studies. Conclusion: The protective effect of HuangQi decoction for unilateral ureteral obstruction kidney damage in mice was mediated by downregulating the TGF-β/Smad signaling pathway.

scholarly journals Danggui Buxue Tang Attenuates Tubulointerstitial Fibrosis via Suppressing NLRP3 Inflammasome in a Rat Model of Unilateral Ureteral Obstruction

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Linna Wang ◽  
Jiwei Ma ◽  
Cunxia Guo ◽  
Changyong Chen ◽  
Zhong Yin ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Ureteral Obstruction ◽  
Smooth Muscle Actin ◽  
Renal Tissue ◽  
Unilateral Ureteral Obstruction ◽  
Collagen Deposition ◽  
Sprague Dawley ◽  
Tubulointerstitial Injury ◽  
Danggui Buxue Tang ◽  
Caspase 1

Inflammation significantly contributes to the progression of chronic kidney disease (CKD). This study aimed to characterize Danggui Buxue Tang (DBT) renoprotection and relationship with NOD-like receptors family pyrin domain-containing 3 (NLRP3) inflammasome expression in rats with unilateral ureteral obstruction (UUO). Sprague-Dawley rats were subjected to UUO and randomly assigned to untreated UUO, enalapril-treated (10 mg/kg/day), and DBT-treated (9 g/kg/day) groups. Sham-operated rats served as controls, with 8 rats in each group. All rats were sacrificed for blood and renal specimen collection at 14 days after UUO. Untreated UUO rats exhibited azotemia, intense tubulointerstitial collagen deposition, upregulations of tubulointerstitial injury index, augmentation levels of collagen I (Col I), α-smooth muscle actin (α-SMA), NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), pro-caspase-1, caspase-1, IL-1β, and pro-IL-1β. DBT treatment significantly attenuated interstitial collagen deposition and tubulointerstitial injury, lowering Col I and α-SMA levels. Synchronous expressions of NLRP3, ASC, pro-caspase-1, caspase-1, pro-IL-1β, and IL-1β decreased in renal tissue. In comparison to enalapril, DBT significantly reduced tubulointerstitial injury, interstitial collagen deposition, and expressions of Col I and IL-1β. Thus, DBT offers renoprotection in UUO rats, which was associated with suppressing NLRP3 inflammasome expression and following reduction of the secretion of cytokine IL-1β. The mechanisms of multitargets of traditional Chinese medicine can be better used for antifibrotic treatment.

scholarly journals Role of the high-affinity leukotriene B4 receptor signaling in fibrosis after unilateral ureteral obstruction in mice

2018 ◽  
Author(s):  
Mariko Kamata ◽  
Hideki Amano ◽  
Yoshiya Ito ◽  
Tomoe Fujita ◽  
Kanako Hosono ◽  
...  
Keyword(s):  
Growth Factor ◽  
Ureteral Obstruction ◽  
Type I Collagen ◽  
Critical Role ◽  
Unilateral Ureteral Obstruction ◽  
Type I ◽  
Renal Tubules ◽  
Kidney Fibrosis ◽  
High Affinity

AbstractLeukotriene B4 (LTB4) is a lipid mediator that acts as a potent chemoattractant for inflammatory leukocytes. Kidney fibrosis is caused by migrating inflammatory cells and kidney-resident cells. Here, we examined the role of the high-affinity LTB4 receptor BLT1 during development of kidney fibrosis in wild-type (WT) mice and BLT1 knockout (BLT1-/-) mice with unilateral ureteral obstruction (UUO). We found elevated expression of 5-lipoxygenase (5-LOX), which generates LTB4, in the renal tubules of WT and BLT1-/- UUO mice. Accumulation of immunoreactive type I collagen in UUO kidneys of WT mice increased over time; however, the increase was less prominent in BLT1-/- mice. Accumulation of S100A4-positive fibroblasts also increased temporally in WT UUO kidneys, but was again less pronounced in those of BLT1-/- mice. The same was true of mRNA encoding transforming growth factor-β (TGF)-β and fibroblast growth factor (FGF)-2. Finally, accumulation of F4/80-positive macrophages, which secrete TGF-β, also increased temporally in WT UUO and BLT1-/- kidneys, but to a lesser extent in the latter. Following LTB4 stimulation in vitro, macrophages showed increased expression of mRNA encoding TGF-β/FGF-2 and Col1a1, whereas L929 fibroblasts showed increased expression of mRNA encoding α smooth muscle actin (SMA). Bone marrow (BM) transplantation studies revealed that the area positive for type I collagen was significantly smaller in BLT1-/--BM→WT UUO kidneys than in WT-BM→WT kidneys. Thus, LTB4-BLT1 signaling plays a critical role in fibrosis in UUO kidneys by increasing accumulation of macrophages and fibroblasts. Therefore, blocking BLT1 may prevent renal fibrosis.

scholarly journals Glucocorticoid-induced cell-derived matrix modulates transforming growth factor β2 signaling in human trabecular meshwork cells

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Felix Yemanyi ◽  
Janice Vranka ◽  
Vijay Krishna Raghunathan
Keyword(s):  
Growth Factor ◽  
Trabecular Meshwork ◽  
Transforming Growth Factor ◽  
Lysyl Oxidase ◽  
Tissue Transglutaminase ◽  
Smooth Muscle Actin ◽  
Plasminogen Activator Inhibitor ◽  
Transglutaminase 2 ◽  
Tissue Growth ◽  
Type I

Abstract Aberrant remodeling of trabecular meshwork (TM) extracellular matrix (ECM) may induce ocular hypertensive phenotypes in human TM (hTM) cells to cause ocular hypertension, via a yet unknown mechanism. Here, we show that, in the absence of exogenous transforming growth factor-beta2 (TGFβ2), compared with control matrices (VehMs), glucocorticoid-induced cell-derived matrices (GIMs) trigger non-Smad TGFβ2 signaling in hTM cells, correlated with overexpression/activity of structural ECM genes (fibronectin, collagen IV, collagen VI, myocilin), matricellular genes (connective tissue growth factor [CTGF], secreted protein, acidic and rich in cysteine), crosslinking genes/enzymes (lysyl oxidase, lysyl oxidase-like 2–4, tissue transglutaminase-2), and ECM turnover genes/enzymes (matrix metalloproteinases-MMP2,14 and their inhibitors-TIMP2). However, in the presence of exogenous TGFβ2, VehMs and GIMs activate Smad and non-Smad TGFβ2 signaling in hTM cells, associated with overexpression of α-smooth muscle actin (α-SMA), and differential upregulation of aforementioned ECM genes/proteins with new ones emerging (collagen-I, thrombospondin-I, plasminogen activator inhibitor, MMP1, 9, ADAMTS4, TIMP1); with GIM-TGFβ2-induced changes being mostly more pronounced. This suggests dual glaucomatous insults potentiate profibrotic signaling/phenotypes. Lastly, we demonstrate type I TGFβ receptor kinase inhibition abrogates VehM-/GIM- and/or TGFβ2-induced upregulation of α-SMA and CTGF. Collectively, pathological TM microenvironments are sufficient to elicit adverse cellular responses that may be ameliorated by targeting TGFβ2 pathway.

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