scholarly journals Salt Inducible Kinase Signaling Networks: Implications for Acute Kidney Injury and Therapeutic Potential

2019 ◽  
Vol 20 (13) ◽  
pp. 3219 ◽  
Author(s):  
Mary Taub
Keyword(s):  
Acute Kidney Injury ◽  
Histone Deacetylases ◽  
Drug Targets ◽  
Epithelial To Mesenchymal Transition ◽  
Therapeutic Potential ◽  
Regulatory Element ◽  
Kidney Injury ◽  
Mesenchymal Transition ◽  
Disease States ◽  
Element Binding Protein

A number of signal transduction pathways are activated during Acute Kidney Injury (AKI). Of particular interest is the Salt Inducible Kinase (SIK) signaling network, and its effects on the Renal Proximal Tubule (RPT), one of the primary targets of injury in AKI. The SIK1 network is activated in the RPT following an increase in intracellular Na+ (Na+in), resulting in an increase in Na,K-ATPase activity, in addition to the phosphorylation of Class IIa Histone Deacetylases (HDACs). In addition, activated SIKs repress transcriptional regulation mediated by the interaction between cAMP Regulatory Element Binding Protein (CREB) and CREB Regulated Transcriptional Coactivators (CRTCs). Through their transcriptional effects, members of the SIK family regulate a number of metabolic processes, including such cellular processes regulated during AKI as fatty acid metabolism and mitochondrial biogenesis. SIKs are involved in regulating a number of other cellular events which occur during AKI, including apoptosis, the Epithelial to Mesenchymal Transition (EMT), and cell division. Recently, the different SIK kinase isoforms have emerged as promising drug targets, more than 20 new SIK2 inhibitors and activators having been identified by MALDI-TOF screening assays. Their implementation in the future should prove to be important in such renal disease states as AKI.

scholarly journals Upregulation of PD-L1 expression promotes epithelial-to-mesenchymal transition in sorafenib-resistant hepatocellular carcinoma cells

2020 ◽  
Vol 8 (5) ◽  
pp. 390-398
Author(s):  
Gui-Li Xu ◽  
Cai-Fang Ni ◽  
Han-Si Liang ◽  
Yun-Hua Xu ◽  
Wan-Sheng Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Epithelial To Mesenchymal Transition ◽  
Regulatory Element ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Knock Down ◽  
Huh7 Cells ◽  
Element Binding Protein ◽  
Hcc Cells ◽  
E Cadherin

Abstract Background The epithelial-to-mesenchymal transition (EMT) status is associated with programmed death-1 ligand 1 (PD-L1) expression in various cancers. However, the role and molecular mechanism of PD-L1 in the EMT of sorafenib-resistant hepatocellular carcinoma (HCC) cells remain elusive. In this study, we aimed to investigate the regulation of PD-L1 on the EMT in sorafenib-resistant HCC cells. Methods Initially, the sorafenib-resistant HCC cell lines HepG2 SR and Huh7 SR were established. Western-blot assays were used to detect the expression of PD-L1, E-cadherin, and N-cadherin. The intervention and overexpression of PD-L1 were used to explore the role of PD-L1 in the regulation of EMT in HepG2 SR and Huh7 SR cells. Cell migration and invasion were assessed by transwell assays. PD-L1 or Sterol regulatory element-binding protein 1 (SREBP-1) overexpression and knock-down were performed in order to study the mechanism of PD-L1 in sorafenib-resistant HCC cells. Results PD-L1 expression was upregulated, whereas E-cadherin levels were downregulated and N-cadherin expression was increased in HepG2 SR and Huh7 SR cells. The cell viabilities of HepG2 and Huh7 cells were lower than those of HepG2 SR and Huh7 SR cells. PD-L1 overexpression reduced E-cadherin expression and increased N-cadherin levels, whereas PD-L1 knock-down increased E-cadherin expression and decreased N-cadherin expression. PD-L1 expression promoted EMT and the migratory and invasive abilities of HepG2 SR and Huh7 SR cells. PD-L1 promoted the EMT of sorafenib-resistant HCC cells via the PI3K/Akt pathway by activating SREBP-1 expression in HepG2 SR and Huh7 SR cells. Conclusions The findings reveal that PD-L1 expression promotes EMT of sorafenib-resistant HCC cells.

scholarly journals Decreased PRC2 activity supports the survival of basal-like breast cancer cells to cytotoxic treatments

2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Iga K. Mieczkowska ◽  
Garyfallia Pantelaiou-Prokaki ◽  
Evangelos Prokakis ◽  
Geske E. Schmidt ◽  
Lukas C. Müller-Kirschbaum ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Targets ◽  
Epithelial To Mesenchymal Transition ◽  
Therapeutic Potential ◽  
Therapy Resistance ◽  
Epigenetic Switch ◽  
Mesenchymal Transition ◽  
Chip Sequencing ◽  
Development Of Resistance ◽  
Basal Like Breast Cancer

AbstractBreast cancer (BC) is the most common cancer occurring in women but also rarely develops in men. Recent advances in early diagnosis and development of targeted therapies have greatly improved the survival rate of BC patients. However, the basal-like BC subtype (BLBC), largely overlapping with the triple-negative BC subtype (TNBC), lacks such drug targets and conventional cytotoxic chemotherapies often remain the only treatment option. Thus, the development of resistance to cytotoxic therapies has fatal consequences. To assess the involvement of epigenetic mechanisms and their therapeutic potential increasing cytotoxic drug efficiency, we combined high-throughput RNA- and ChIP-sequencing analyses in BLBC cells. Tumor cells surviving chemotherapy upregulated transcriptional programs of epithelial-to-mesenchymal transition (EMT) and stemness. To our surprise, the same cells showed a pronounced reduction of polycomb repressive complex 2 (PRC2) activity via downregulation of its subunits Ezh2, Suz12, Rbbp7 and Mtf2. Mechanistically, loss of PRC2 activity leads to the de-repression of a set of genes through an epigenetic switch from repressive H3K27me3 to activating H3K27ac mark at regulatory regions. We identified Nfatc1 as an upregulated gene upon loss of PRC2 activity and directly implicated in the transcriptional changes happening upon survival to chemotherapy. Blocking NFATc1 activation reduced epithelial-to-mesenchymal transition, aggressiveness, and therapy resistance of BLBC cells. Our data demonstrate a previously unknown function of PRC2 maintaining low Nfatc1 expression levels and thereby repressing aggressiveness and therapy resistance in BLBC.

scholarly journals miRNA proxy approach reveals hidden functions of glycosylation

2015 ◽  
Vol 112 (23) ◽  
pp. 7327-7332 ◽  
Author(s):  
Tomasz Kurcon ◽  
Zhongyin Liu ◽  
Anika V. Paradkar ◽  
Christopher A. Vaiana ◽  
Sujeethraj Koppolu ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Epithelial To Mesenchymal Transition ◽  
Biological Function ◽  
Regulatory Elements ◽  
Rapid Identification ◽  
Mesenchymal Transition ◽  
Disease States ◽  
Mesenchymal To Epithelial Transition ◽  
Genes Encoding ◽  
Target Network

Glycosylation, the most abundant posttranslational modification, holds an unprecedented capacity for altering biological function. Our ability to harness glycosylation as a means to control biological systems is hampered by our inability to pinpoint the specific glycans and corresponding biosynthetic enzymes underlying a biological process. Herein we identify glycosylation enzymes acting as regulatory elements within a pathway using microRNA (miRNA) as a proxy. Leveraging the target network of the miRNA-200 family (miR-200f), regulators of epithelial-to-mesenchymal transition (EMT), we pinpoint genes encoding multiple promesenchymal glycosylation enzymes (glycogenes). We focus on three enzymes, beta-1,3-glucosyltransferase (B3GLCT), beta-galactoside alpha-2,3-sialyltransferase 5 (ST3GAL5), and (alpha-N-acetyl-neuraminyl-2,3-beta-galactosyl-1,3)-N-acetylgalactosaminide alpha-2,6-sialyltransferase 5 (ST6GALNAC5), encoding glycans that are difficult to analyze by traditional methods. Silencing these glycogenes phenocopied the effect of miR-200f, inducing mesenchymal-to-epithelial transition. In addition, all three are up-regulated in TGF-β–induced EMT, suggesting tight integration within the EMT-signaling network. Our work indicates that miRNA can act as a relatively simple proxy to decrypt which glycogenes, including those encoding difficult-to-analyze structures (e.g., proteoglycans, glycolipids), are functionally important in a biological pathway, setting the stage for the rapid identification of glycosylation enzymes driving disease states.

α2-Adrenoceptor agonist dexmedetomidine protects septic acute kidney injury through increasing BMP-7 and inhibiting HDAC2 and HDAC5

2012 ◽  
Vol 303 (10) ◽  
pp. F1443-F1453 ◽  
Author(s):  
Chung-Hsi Hsing ◽  
Chiou-Feng Lin ◽  
Edmund So ◽  
Ding-Ping Sun ◽  
Tai-Chi Chen ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Histone Deacetylases ◽  
Trichostatin A ◽  
Histone H3 ◽  
Cecal Ligation ◽  
Kidney Injury ◽  
Protective Effects ◽  
Tnf Α

Bone morphogenetic protein (BMP)-7 protects sepsis-induced acute kidney injury (AKI). Dexmedetomidine (DEX), an α2-adrenoceptor (α2-AR) agonist, has anti-inflammatory effects. We investigated the protective effects of DEX on sepsis-induced AKI and the expression of BMP-7 and histone deacetylases (HDACs). In vitro , the effects of DEX or trichostatin A (TSA, an HDAC inhibitor) on TNF-α, monocyte chemotactic protein (MCP-1), BMP-7, and HDAC mRNA expression in LPS-stimulated rat renal tubular epithelial NRK52E cells, was determined using real-time PCR. In vivo, mice were intraperitoneally injected with DEX (25 μg/kg) or saline immediately and 12 h after cecal ligation and puncture (CLP) surgery. Twenty-four hours after CLP, we examined kidney injury and renal TNF-α, MCP-1, BMP-7, and HDAC expression. Survival was monitored for 120 h. LPS increased HDAC2, HDAC5, TNF-α, and MCP-1 expression, but decreased BMP-7 expression in NRK52E cells. DEX treatment decreased the HDAC2, HDAC5, TNF-α, and MCP-1 expression, but increased BMP-7 and acetyl histone H3 expression, whose effects were blocked by yohimbine, an α2-AR antagonist. With DEX treatment, the LPS-induced TNF-α expression and cell death were attenuated in scRNAi-NRK52E but not BMP-7 RNAi-NRK52E cells. In CLP mice, DEX treatment increased survival and attenuated AKI. The expression of HDAC2, HDAC5, TNF-α, and MCP-1 mRNA in the kidneys of CLP mice was increased, but BMP-7 was decreased. However, DEX treatment reduced those changes. DEX reduces sepsis-induced AKI by decreasing TNF-α and MCP-1 and increasing BMP-7, which is associated with decreasing HDAC2 and HDAC5, as well as increasing acetyl histone H3.

scholarly journals miR-33a Mediates the Anti-Tumor Effect of Lovastatin in Osteosarcoma by Targeting CYR61

2018 ◽  
Vol 51 (2) ◽  
pp. 938-948 ◽  
Author(s):  
Yazeng Huang ◽  
Jun Zhang ◽  
Haiyu Shao ◽  
Jianwen Liu ◽  
Mengran Jin ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cell Invasion ◽  
Epithelial To Mesenchymal Transition ◽  
Regulatory Element ◽  
Luciferase Reporter Assay ◽  
Luciferase Reporter ◽  
Osteosarcoma Cell ◽  
Reporter Assay ◽  
Related Protein ◽  
Mesenchymal Transition

Background/Aims: Preventing cell metastasis is an effective therapeutic strategy to treat osteosarcoma and improve prognosis. Statins have been found to have anticancer effects in addition to their cholesterol-lowering action. As a new target of statins, cysteine-rich 61 (CYR61) was recently identified to promote cell migration and metastasis in osteosarcoma. However, the underlying mechanisms mediating the regulation of CYR61 expression by statins remain unknown. Methods: Human osteosarcoma cell lines MG63 and SaOS2 were used to clarify the effect of lovastatin on CYR61 expression. Real-time PCR was performed to detect mRNA or microRNA (miRNA) levels and western blot was performed to detect protein levels. Cell invasive ability was determined using Transwell assays. Lentivirus encoding CYR61 cDNA or sterol regulatory element-binding protein 2 (SREBP-2) shRNA was used to upregulate CYR61 expression or downregulate SREBP-2 expression. Binding of the CYR61 3’ untranslated region (UTR) and miR-33a was analyzed by luciferase reporter assay. Results: We found that lovastatin treatment decreased CYR61 expression, inhibited cell invasion and altered epithelial-to-mesenchymal-transition (EMT)-related protein expression, while CYR61 overexpression abolished the effect of lovastatin. Moreover, lovastatin increased the expression of SREBP-2 and miR-33a, which were then downregulated by SREBP-2 silencing. Bioinformatics analysis indicated that the CYR61 3′UTR harbored a potential miR-33a binding site and luciferase reporter assay demonstrated that CYR61 was a target of miR-33a in osteosarcoma cells. Furthermore, miR-33a could inhibit cell invasion and alter EMT-related protein expression. SREBP-2 silencing or miR-33a inhibitor upregulated CYR61 expression and reversed the effects of lovastatin on cell invasion and EMT-related proteins. Conclusion: Our findings suggest lovastatin suppresses osteosarcoma cell invasion through the SREBP-2/miR-33a/CYR61 pathway.

scholarly journals Disruption of Cancer Metabolic SREBP1/miR-142-5p Suppresses Epithelial–Mesenchymal Transition and Stemness in Esophageal Carcinoma

Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 7 ◽  
Author(s):  
Chih-Ming Huang ◽  
Chin-Sheng Huang ◽  
Tung-Nien Hsu ◽  
Mao-Suan Huang ◽  
Iat-Hang Fong ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Survival Rate ◽  
Tumor Suppressor ◽  
Poor Prognosis ◽  
Epithelial Mesenchymal Transition ◽  
Therapeutic Potential ◽  
Regulatory Element ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
E Cadherin

Elevated activity of sterol regulatory element-binding protein 1 (SREBP1) has been implicated in the tumorigenesis of different cancer types. However, the functional roles of SREBP1 in esophageal cancer are not well appreciated. Here, we aimed to investigate the therapeutic potential of SREBP1 and associated signaling in esophageal cancer. Our initial bioinformatics analyses showed that SREBP1 expression was overexpressed in esophageal tumors and correlated with a significantly lower overall survival rate in patients. Additionally, tumor suppressor miR-142-5p was predicted to target SREBP1/ZEB1 and a lower miR-142-5p was correlated with poor prognosis. We then performed in vitro experiments and showed that overexpressing SREBP1 in OE33 cell line led to increased abilities of colony formation, migration, and invasion; the opposite was observed in SREBP1-silenced OE21cells and SREBP1-silencing was accompanied by the reduced mesenchymal markers, including vimentin (Vim) and ZEB1, while E-cadherin and tumor suppressor miR-142-5p were increased. Subsequently, we first demonstrated that both SREBP1 and ZEB1 were potential targets of miR-142-5p, followed by the examination of the regulatory circuit of miR-142-5p and SREBP1/ZEB1. We observed that increased miR-142-5p level led to the reduced tumorigenic properties, such as migration and tumor sphere formation, and both observations were accompanied by the reduction of ZEB1 and SREBP1, and increase of E-cadherin. We then explored the potential therapeutic agent targeting SREBP1-associated signaling by testing fatostatin (4-hydroxytamoxifen, an active metabolite of tamoxifen). We found that fatostatin suppressed the cell viability of OE21 and OE33 cells and tumor spheres. Interestingly, fatostatin treatment reduced CD133+ population in both OE21 and OE33 cells in concert of increased miR-142-5p level. Finally, we evaluated the efficacy of fatostatin using a xenograft mouse model. Mice treated with fatostatin showed a significantly lower tumor burden and better survival rate as compared to their control counterparts. The treatment of fatostatin resulted in the reduced staining of SREBP1, ZEB1, and Vim, while E-cadherin and miR-142-5p were increased. In summary, we showed that increased SREBP1 and reduced miR-142-5p were associated with increased tumorigenic properties of esophageal cancer cells and poor prognosis. Preclinical tests showed that suppression of SREBP1 using fatostatin led to the reduced malignant phenotype of esophageal cancer via the reduction of EMT markers and increased tumor suppressor, miR-142-5p. Further investigation is warranted for the clinical use of fatostatin for the treatment of esophageal malignancy.

scholarly journals Roles of MicroRNA-34a in Epithelial to Mesenchymal Transition, Competing Endogenous RNA Sponging and Its Therapeutic Potential

2019 ◽  
Vol 20 (4) ◽  
pp. 861 ◽  
Author(s):  
Dongsong Nie ◽  
Jiewen Fu ◽  
Hanchun Chen ◽  
Jingliang Cheng ◽  
Junjiang Fu
Keyword(s):  
Cancer Therapy ◽  
Cancer Progression ◽  
Noncoding Rna ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Therapeutic Potential ◽  
Circular Rna ◽  
Signal Pathways ◽  
Competing Endogenous Rna ◽  
Mesenchymal Transition

MicroRNA-34a (miR-34a), a tumor suppressor, has been reported to be dysregulated in various human cancers. MiR-34a is involves in certain epithelial-mesenchymal transition (EMT)-associated signal pathways to repress tumorigenesis, cancer progression, and metastasis. Due to the particularity of miR-34 family in tumor-associated EMT, the significance of miR-34a is being increasingly recognized. Competing endogenous RNA (ceRNA) is a novel concept involving mRNA, circular RNA, pseudogene transcript, and long noncoding RNA regulating each other’s expressions using microRNA response elements to compete for the binding of microRNAs. Studies showed that miR-34a is efficient for cancer therapy. Here, we provide an overview of the function of miR-34a in tumor-associated EMT. ceRNA hypothesis plays an important role in miR-34a regulation in EMT, cancer progression, and metastasis. Its potential roles and challenges as a microRNA therapeutic candidate are discussed. As the negative effect on cancer progression, miR-34a should play crucial roles in clinical diagnosis and cancer therapy.

scholarly journals The p53 inhibitor pifithrin-α can stimulate fibrosis in a rat model of ischemic acute kidney injury

2012 ◽  
Vol 302 (2) ◽  
pp. F284-F291 ◽  
Author(s):  
Pierre C. Dagher ◽  
Erik M. Mai ◽  
Takashi Hato ◽  
So-Young Lee ◽  
Melissa D. Anderson ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Inflammatory Responses ◽  
Kidney Injury ◽  
Vehicle Control ◽  
Acute Administration ◽  
Protective Effects ◽  
Long Term Effects ◽  
Mesenchymal Transition ◽  
The Impact ◽  
Microvascular Rarefaction

Inhibition of the tumor suppressor p53 diminishes tubular cell apoptosis and protects renal function in animal models of acute kidney injury (AKI). Therefore, targeting p53 has become an attractive therapeutic strategy in the approach to AKI. Although the acute protective effects of p53 inhibition in AKI have been examined, there is still relatively little known regarding the impact of acute p53 inhibition on the chronic sequelae of AKI. Consequently, we utilized the p53 inhibitor pifithrin-α to examine the long-term effects of p53 inhibition in a rodent model of ischemic AKI. Male Sprague-Dawley rats were subjected to bilateral renal artery clamping for 30 min followed by reperfusion for up to 8 wk. Pifithrin-α or vehicle control was administered at the time of surgery and then daily for 2 days [brief acute administration (BA)] or 7 days [prolonged acute administration (PA)]. Despite the acute protective effect of pifithrin-α in models of ischemic AKI, we found no protection in the microvascular rarefaction at 4 wk or development fibrosis at 8 wk with pifithrin-α administered on the BA schedule compared with vehicle control-treated animals. Furthermore, pifithrin-α administered on a PA schedule actually produced worse fibrosis compared with vehicle control animals after ischemic injury [21%/area (SD4.4) vs.16%/area (SD3.6)] as well as under sham conditions [2.6%/area (SD1.8) vs. 4.7%/area (SD1.3)]. The development of fibrosis with PA administration was independent of microvascular rarefaction. We identified enhanced extracellular matrix production, epithelial-to-mesenchymal transition, and amplified inflammatory responses as potential contributors to the augmented fibrosis observed with PA administration of pifithrin-α.

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