scholarly journals JTZ-951, an HIF prolyl hydroxylase inhibitor, suppresses renal interstitial fibroblast transformation and expression of fibrosis-related factors

2020 ◽  
Vol 318 (1) ◽  
pp. F14-F24 ◽  
Author(s):  
Takeshi Wakashima ◽  
Tetsuhiro Tanaka ◽  
Kenji Fukui ◽  
Yasumasa Komoda ◽  
Yuichi Shinozaki ◽  
...  

Some preceding studies have provided evidence that hypoxia-inducible factor (HIF)-prolyl hydroxylase (PH) inhibitors have therapeutic potential against tubular interstitial fibrosis (TIF). Recently, transformation of renal interstitial fibroblasts (RIFs) into α-smooth muscle actin-positive myofibroblasts with loss of their hypoxia-inducible erythropoietin (EPO) expression has been hypothesized as the central mechanism responsible for TIF with renal anemia (the RIF hypothesis). These reports have suggested that HIF-PH inhibitors may suppress TIF via suppressing transformation of RIFs. However, the direct effect of HIF-PH inhibitors on transformation of RIFs has not been demonstrated because there has been no appropriate assay system. Here, we established a novel in vitro model of the transformation of RIFs. This model expresses key phenotypic changes such as transformation of RIFs accompanied by loss of their hypoxia-inducible EPO expression, as proposed by the RIF hypothesis. Using this model, we demonstrated that JTZ-951, a newly developed HIF-PH inhibitor, stabilized HIF protein in RIFs, suppressed transformation of RIFs, and maintained their hypoxia-inducible EPO expression. JTZ-951 also suppressed the expression of FGF2, FGF7, and FGF18, which are upregulated during transformation of RIFs. Furthermore, expression of Fgf2, Fgf7, and Fgf18 was correlated with TIF in an animal model of TIF. We also demonstrated that not only FGF2, which is a well-known growth-promoting factor, but also FGF18 promoted proliferation of RIFs. These data suggest that JTZ-951 has therapeutic potential against TIF with renal anemia. Furthermore, FGF2, FGF7, and FGF18, which faithfully reflect the anti-TIF effects of JTZ-951, have potential as TIF biomarkers.

2021 ◽  
Author(s):  
Moses Philip ◽  
Abdul Khader Karakka Kal ◽  
Michael Benedict Subhahar ◽  
Tajudheen K. Karatt ◽  
Binoy Mathew ◽  
...  

2018 ◽  
Author(s):  
Nina Kozlova ◽  
Daniela Mennerich ◽  
Anatoly Samoylenko ◽  
Elitsa Y. Dimova ◽  
Peppi Koivunen ◽  
...  

SummaryThe EGFR-adaptor protein CIN85 has been shown to promote breast cancer malignancy and hypoxia-inducible factor (HIF) stability. However, the mechanisms underlying cancer promotion remain ill-defined. Here, we show that CIN85 is a novel binding partner of the main HIF-prolyl hydroxylase PHD2, but not of PHD1 or PHD3. Mechanistically, the N-terminal SH3 domains of CIN85 interact with the proline-arginine rich region within the N-terminus of PHD2, thereby inhibiting PHD2 activity and HIF-degradation. This activity is essential in vivo, as specific loss of the CIN85-PHD2 interaction in CRISPR/Cas9 edited cells affected growth and migration properties as well as tumor growth in mice. Overall, we discovered a previously unrecognized tumor growth checkpoint that is regulated by CIN85-PHD2, and uncovered an essential survival function in tumor cells linking growth factor adaptors with hypoxia signaling.


2021 ◽  
Author(s):  
Yan Lin ◽  
Mingjing Wang ◽  
Zhen Xiao ◽  
Zhiyan Jiang

Abstract Adenoid hypertrophy (AH) can cause harmful effects on untreated children, which include mouth breathing, chronic intermittent hypoxia, sleep disordered breathing (SDB), and even some behavioral problems. However, the molecular mechanisms underlying this pathophysiological process have remained poorly understood. In this study, with use of a variety of biochemical approaches including gene silencing and transiently ectopic protein expression, we examined the molecular effectors involved in this process in an in vitro model of human tonsil epithelial cells (HTECs). We found that a hypoxic condition caused a dramatic upregulation of SUMO-1 expression, a member of the ubiquitin-like protein family, which in turn stabilized hypoxia-inducible factor (HIF)-1α by sumoylating this HIF subunit and thus preventing its ubiquitination and degradation in HTECs. We also found that activating HIF-1α promoted permeability of HTEC cells as well as production and secretion of a variety of proinflammatory cytokines including IL-6, IL-8, and TNF-α, and pro-angiogenic growth factor VEGF. Furthermore, our data showed that hypoxia-induced inflammation was markedly inhibited by M2 macrophages that possess potent anti-inflammatory function. Our results suggest that selectively inhibiting the SUMO-1-HIF-1α signaling pathway leads to inflammatory responses in human tonsil epithelial cells, which might be a novel therapeutic approach for managing hypoxia-induced SDB resulting from AH.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Toshihiro Ichiki

Background: Prolyl hydroxylase domain-containing protein (PHD) mediates hydroxylation of hypoxia-inducible factor (HIF)-1α and thereby induces proteasomal degradation of HIF-1α. Inhibition of PHD by hypoxia or hypoxia mimetics such as cobalt chloride (CoCl2) stabilizes HIF-1 and increases the expression of target genes such as vascular endothelial growth factor (VEGF). Although hypoxia activates the systemic renin angiotensin system (RAS), the role of PHD in regulating RAS remains unknown. We examined the effect of PHD inhibition on the expression of angiotensin (Ang) II type 1 receptor (AT1R) and its signaling. Methods and Results: Hypoxia (1% O2), CoCl2 (100-300 μmol/L), and dimethyloxalylglycine (0.25-1.0 mmol/L), all known to inhibit PHD, reduced AT1R expression by 37.7±7.6, 39.6±8.4-69.7±9.9, and 13.4±6.1-25.2±7.0%, respectively (p<0.01) in cultured vascular smooth muscle cell. The same stimuli increased the expression of nuclear HIF-1α and VEGF (p<0.05), suggesting that PHD activity is inhibited. Knockdown of PHD2, a major isoform of PHDs, by RNA interference also reduced AT1R expression by 55.3±6.0% (p<0.01). CoCl2 decreased AT1R mRNA through transcriptional and posttranscriptional mechanisms (p<0.01 and <0.05, respectively). CoCl2 and PHD2 knockdown diminished Ang II-induced ERK phosphorylation (P<0.01). Over-expression of the constitutively active HIF-1α did not impact the AT1R gene promoter activity. Oral administration of CoCl2 (14 mg/kg/day) to C57BL/6J mice receiving Ang II infusion (490 ng/kg/min) for 4 weeks significantly reduced the expression of AT1R in the aorta by 60.9±11.3% (p<0.05) and attenuated coronary perivascular fibrosis by 85% (p<0.01) without affecting blood pressure. However, CoCl2 did not affect Ang II-induced renal interstitial fibrosis. Conclusion: PHD inhibition downregulates AT1R expression independently of HIF-1α, reduces the cellular response to Ang II, and attenuates profibrotic effect of Ang II on the coronary arteries. PHD inhibition may be beneficial for the treatment of cardiovascular diseases, in which activation of RAS plays a critical role.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Joshua G Travers ◽  
Fadia A Kamal ◽  
Michael S Burhans ◽  
Burns C Blaxall

Heart failure (HF) is a devastating disease characterized by chamber remodeling, interstitial fibrosis and reduced ventricular compliance. Prolonged sympathetic overstimulation promotes excess signaling through G-protein Gβγ subunits and ultimately results in pathologic GRK2-mediated β-adrenergic receptor (β-AR) downregulation. We have recently demonstrated the therapeutic potential of the small molecule Gβγ-GRK2 inhibitor Gallein in limiting HF progression. Pathologic activation of the cardiac fibroblast (CF) induces the transition to a myofibroblast phenotype, which plays a fundamental role in myocardial fibrosis and remodeling. We hypothesized that Gβγ-GRK2 inhibition plays an important functional role in the CF to attenuate pathologic CF activation, inflammation and interstitial fibrosis. To explore the effect of Gβγ-GRK2 inhibition on inflammation and pro-fibrotic signaling, mice were subjected to 7 days of transverse aortic constriction, a pressure-overload model of HF. In addition to the attenuation in overall cardiac hypertrophy, animals treated with Gallein displayed reduced expression of pro-inflammatory cytokines, including macrophage inflammatory protein 1 alpha (MIP-1α) and MIP-1β, along with Interleukin-6, as assessed by qPCR. Gallein-treated animals also exhibited diminished pro-fibrotic signaling, as evidenced by a reduction in the expression of TGFβ, a major driver of myocardial fibrosis, and decreased expression of collagen. To recapitulate these findings in vitro, primary adult mouse ventricular fibroblasts were pathologically stimulated using Isoproterenol (ISO, β-AR agonist) or Angiotensin II and treated +/- Gallein for 24 hours. CFs treated with Gallein displayed an analogous reduction in the expression of these pro-inflammatory cytokines and collagen. In summary, these data suggest a potential therapeutic role for small molecule Gβγ-GRK2 inhibition in limiting pathologic myofibroblast activation, inflammation and interstitial fibrosis. We believe this fibroblast-targeted approach will lead to the refinement of existing targets and compounds, and possibly the generation of novel therapeutics for the treatment of HF.


Biomedicines ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 164 ◽  
Author(s):  
Giacomo Picciolo ◽  
Giovanni Pallio ◽  
Domenica Altavilla ◽  
Mario Vaccaro ◽  
Giacomo Oteri ◽  
...  

Human gingival fibroblasts (GF) and human oral mucosa epithelial cells (EC) with an inflammatory phenotype represent a valuable experimental paradigm to explore the curative activity of agents to be used in oral mucositis. The role of cannabinoid receptor 2 (CB2) has not yet been investigated in oral mucositis. The aim of this study was to evaluate the therapeutic potential of β-Caryophyllene (BCP), a CB2 agonist, in an in vitro model of oral mucositis. GF and EC were stimulated with LPS (2 µg/mL) alone or in combination with BCP; a group of LPS challenged GF and EC were treated with BCP and AM630, a CB2 antagonist. LPS increased the inflammatory cytokines TNF-α, IL-1β, IL-6 and IL-17A whereas it decreased the anti-inflammatory cytokine IL-13. The upstream signals were identified in an augmented expression of NF-κB and STAT-3 and in reduced mRNA levels of PPARγ and PGC-1α. BCP blunted the LPS-induced inflammatory phenotype and this effect was reverted by the CB2 antagonist AM630. These results suggest that CB2 receptors are an interesting target to develop innovative strategies for oral mucositis and point out that BCP exerts a marked curative effect in a preclinical model of oral mucositis which deserves to be confirmed in a clinical setting.


2020 ◽  
Vol 21 (24) ◽  
pp. 9513
Author(s):  
Patricia Garrido-Pascual ◽  
Ana Alonso-Varona ◽  
Begoña Castro ◽  
María Burón ◽  
Teodoro Palomares

Oxidative stress associated with neuroinflammation is a key process involved in the pathophysiology of neurodegenerative diseases, and therefore, has been proposed as a crucial target for new therapies. Recently, the therapeutic potential of human adipose-derived stem cells (hASCs) has been investigated as a novel strategy for neuroprotection. These cells can be preconditioned by exposing them to mild stress in order to improve their response to oxidative stress. In this study, we evaluate the therapeutic potential of hASCs preconditioned with low doses of H2O2 (called HC016 cells) to overcome the deleterious effect of oxidative stress in an in vitro model of oligodendrocyte-like cells (HOGd), through two strategies: i, the culture of oxidized HOGd with HC016 cell-conditioned medium (CM), and ii, the indirect co-culture of oxidized HOGd with HC016 cells, which had or had not been exposed to oxidative stress. The results demonstrated that both strategies had reparative effects, oxidized HC016 cell co-culture being the one associated with the greatest recovery of the damaged HOGd, increasing their viability, reducing their intracellular reactive oxygen species levels and promoting their antioxidant capacity. Taken together, these findings support the view that HC016 cells, given their reparative capacity, might be considered an important breakthrough in cell-based therapies.


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