In-depth exploration of the shared genetic signature and molecular mechanisms between end-stage renal disease and osteoporosis.

Background: Osteoporosis (OS) and fractures are common in patients with end-stage renal disease (ESRD) and maintenance dialysis patients. However, diagnosing osteoporosis in this population is challenging. The aim of this research is to explore the common genetic profile and potential molecular mechanisms of ESRD and OS. Methods and results: Download microarray data for ESRD and OS from the Gene Expression Omnibus (GEO) database. Weighted correlation network analysis (WGCNA) was used to identify co-expression modules associated with ESRD and OS. Random Forest (RF) and Lasso Regression were performed to identify candidate genes, and consensus clustering for hierarchical analysis. In addition, miRNAs shared in ESRD and OS were identified by differential analysis and their target genes were predicted by Tragetscan. Finally, we constructed a common miRNAs-mRNAs network with candidate genes and shared miRNAs. By WGCNA, two important modules of ESRD and one important module of OS were identified, and the functions of three major clusters were identified, including ribosome, RAS pathway, and MAPK pathway. Eight gene signatures obtained by using RF and Lasso machine learning methods with area under curve (AUC) values greater than 0.7 in ESRD and in OS confirmed their diagnostic performance. Consensus clustering successfully stratified ESRD patients, and C1 patients with more severe ESRD phenotype and OS phenotype were defined as "OS-prone group". Conclusion: Our work identifies biological processes and underlying mechanisms shared by ESRD and OS, and identifies new candidate genes that can be used as biomarkers or potential therapeutic targets, revealing molecular alterations in susceptibility to OS in ESRD patients.

Combined HASPIN and mTOR inhibition is synergistic against KRAS-driven carcinomas.

BACKGROUND: Oncogenic mutations in the KRAS gene are very common in human cancers, resulting in cells with well-characterized selective advantages. For more than three decades, the development of effective therapeutics to inhibit KRAS-driven tumorigenesis has proved a formidable challenge and KRAS was considered 'undruggable'. Therefore, multi-targeted therapy may provide a reasonable strategy for the effective treatment of KRAS-driven cancers. Here, we assess the efficacy and mechanistic rationale for combining HASPIN and mTOR inhibition as a potential therapy for cancers carrying KRAS mutations. METHODS: We investigated the synergistic effect of a combination of mTOR and HASPIN inhibitors on cell viability, cell cycle, cell apoptosis, DNA damage, and mitotic catastrophe using a panel of human KRAS-mutant and wild-type tumor cell lines. Subsequently, the human transplant models were used to test the therapeutic efficacy and pharmacodynamic effects of the dual therapy. RESULTS: We demonstrated that the combination of mTOR and HASPIN inhibitors induced potent synergistic cytotoxic effects in KRAS-mutant cell lines and delayed the growth of human tumor xenograft. Mechanistically, we showed that inhibiting of mTOR potentiates HASPIN inhibition by preventing the phosphorylation of H3 histones, exacerbating mitotic catastrophe and DNA damage in tumor cell lines with KRAS mutations, and this effect is due in part to a reduction in VRK1. CONCLUSIONS: These findings indicate that increased DNA damage and mitotic catastrophe are the basis for the effective synergistic effect observed with mTOR and HASPIN inhibition, and support the clinical evaluation of this dual therapy in patients with KRAS-mutant tumors.

Aberrant activation of m6A demethylase FTO renders HIF2αlow/- clear cell renal cell carcinoma sensitive to BRD9 inhibitors.

Hypoxia-inducible factor 2α (HIF2α) antagonists are effective against clear cell renal cell carcinomas (ccRCCs) that highly express HIF2α. To identify potential drug targets in HIF2αlow/− ccRCC, we constructed an epigenetic-focused single-guide RNA library and performed an in vivo CRISPR-Cas9 knockout screen in BALB/c nude mice transplanted with 786-O (HIF2αhigh) or Caki-2 (HIF2αlow/−) cells. We found that the m6A demethylase fat mass and obesity-associated (FTO) gene was indispensable to the growth of HIF2αlow/− but not HIF2αhigh ccRCC. Activation of FTO in HIF2αlow/− ccRCC was caused by an increased intracellular α-ketoglutarate­to-succinate ratio and stabilized bromodomain-containing protein 9 (BRD9) messenger RNA via m6A demethylation. RNA sequencing and chromatin immunoprecipitation sequencing profiling further revealed that SRY-box transcription factor 17 (SOX17) recruited BRD9 to de novo super enhancers associated with genes that feature prominently in ccRCC pathogenesis, including CCND1, VEGFR2, CDC20, SRC, and MAPK6. BRD9 knockdown or the BRD9-selective antagonist I-BRD9 suppressed the growth of HIF2αlow/− but not HIF2αhigh ccRCC cells in vitro. In BALB/c nude mice bearing HIF2αlow/− ccRCC cell line­derived xenografts and patient-derived tumor xenografts, I-BRD9 administration effectively inhibited tumor growth and prolonged the survival of tumor-bearing mice with greater efficacy than sunitinib. Together, these findings indicate that BRD9 is a druggable target for treating HIF2αlow/− ccRCC.

Bromodomain-containing protein 9 is a prognostic biomarker associated with immune infiltrates and promotes tumor malignancy through activating notch signaling pathway in negative HIF-2α clear cell renal cell carcinoma.

HIF-2α selective inhibitor showed successful efficacy in sensitive clear cell renal cell carcinoma (ccRCC) presenting higher levels of HIF-2α compared to resistant tumors with low level of HIF-2α (negative HIF-2α ccRCC). Currently, negative HIF-2α ccRCC lacks truly effective therapeutic agents to improve the outcomes. Bromodomain-containing protein 9 (BRD9) plays a critical role in human hepatocellular carcinoma, squamous cell lung cancer, acute myeloid leukemia, and so on. However, expression and biological role of BRD9 in negative HIF-2α ccRCC is poorly understood. Clinically, we demonstrated that expression of BRD9 in negative HIF-2α ccRCC tissues was higher than that in positive HIF-2α ccRCC. Moreover, high BRD9 expression was correlated with unfavorable clinicopathological features and predicted the poor overall survival of negative HIF-2α ccRCC patients. Functionally, BRD9 knockout resulted in reduced proliferation, migration and invasion of negative HIF-2α ccRCC cells (Caki-2). In addition, BRD9 was related to the TIIC infiltration level in negative HIF-2α ccRCC tissues. Mechanistically, Gene set enrichment analysis (GSEA) showed that BRD9 was closely related to Notch signaling pathway. BRD9 knockout resulted in reduced mRNA level of Hes1 and Notch1 in negative HIF-2α ccRCC in vitro. The overexpression of NICD (Notch intracellular domain) enhanced malignant behaviors of Caki-2 cells with BRD9 knockout. And Notch inhibition led to attenuation of cell growth and reduced migration and invasion in Caki-2 cells. Overall, our results identified that BRD9 promotes the proliferation, migration and invasion of negative HIF-2α ccRCC cells by targeting Notch signaling pathway and serve as a promising biomarker for negative HIF-2α ccRCC.

Cardioprotective effect of rosmarinic acid against myocardial ischaemia/reperfusion injury via suppression of the NF-κB inflammatory signalling pathway and ROS production in mice.

CONTEXT: Rosmarinic acid (RosA), a natural poly-phenolic compound isolated from a variety of Labiatae herbs, has been reported to have a range of biological effects. OBJECTIVE: To investigate the cardioprotective effects of RosA against myocardial ischaemia/reperfusion (I/R) injury. MATERIALS AND METHODS: Male C57BL/6J mice were given RosA (100 mg/kg) via intragastric administration. After 1 week of administration, the mice were subjected to 30 min/24 h myocardial I/R injury. The mice were randomly subdivided into 4 groups: Vehicle, RosA, Vehicle + I/R, and RosA + I/R. Infarct size (IS), cardiac function (including EF, FS), histopathology, serum enzyme activities, ROS changes, cis aconitase (ACO) activity, and specific mRNA and protein levels were assessed in vivo. HL-1 cells were pre-treated with or without RosA (50 µM), followed by stimulation with 9 h/6 h of oxygen and glucose deprivation/re-oxygenation (OGD/R). The cells were randomly subdivided into 4 groups: Vehicle, RosA, Vehicle + OGD/R, and RosA + OGD/R. Lactate dehydrogenase (LDH) levels, ACO activity, ROS changes and protein levels were measured in vitro. RESULTS: Treatment with RosA reduced the following indicators in vivo (p < 0.05): (1) IS (14.5%); (2) EF (-23.4%) and FS (-18.4%); (3) the myocardial injury enzymes CK-MB (20.8 ng/mL) and cTnI (7.7 ng/mL); (4) DHE-ROS: (94.1%); (5) ACO activity (-2.1 mU/mg protein); (6) ogdh mRNA level (122.9%); and (7) OGDH protein level (69.9%). Moreover, treatment with RosA attenuated the following indicators in vitro (p < 0.05): (1) LDH level (191 U/L); (2) DHE-ROS: (165.2%); (3) ACO activity (-3.2 mU/mg protein); (4) ogdh mRNA level (70.0%); and (5) OGDH (110.1%), p-IκB-a (56.8%), and p-NF-κB (57.7%) protein levels. CONCLUSIONS: RosA has the potential to treat myocardial I/R injury with potential application in the clinic.

The MicroRNA-199a/214 Cluster Targets E-Cadherin and Claudin-2 and Promotes High Glucose-Induced Peritoneal Fibrosis.

Serum response factor (SRF) was found to be involved in the phenotypic transition and fibrosis of the peritoneal membrane during treatment with peritoneal dialysis (PD), but the exact mechanism remains unclear. SRF regulates microRNAs (miRNAs) that contain the SRF-binding consensus (CArG) element in the promoter region. Therefore, we investigated whether the miR-199a/214 gene cluster, which contains a CArG element in its promoter, is directly regulated by SRF. High-glucose (HG) treatment significantly unregulated the expression of the miR-199a-5p/214-3p gene cluster in human peritoneal mesothelial cells (HPMCs). By chromatin immunoprecipitation and reporter assays, we found that SRF binds to the miR-199a-5p/214-3p gene cluster promoter after HG stimulation. In vitro, in HPMCs, silencing of miR-199a-5p or miR-214-3p inhibited the HG-induced phenotypic transition and cell migration but enhanced cell adhesion, whereas ectopic expression of mimic oligonucleotides had the opposite effects. Both miR-199a-5p and miR-214-3p targeted claudin-2 and E-cadherin mRNAs. In a PD rat model, treatment with an SRF inhibitor silenced miR-199a-5p and miR-214-3p and alleviated HG-PD fluid-induced damage and fibrosis. Overall, this study reveals a novel SRF-miR-199a/miR-214-E-cadherin/claudin-2 axis that mediates damage and fibrosis in PD.

Cardioprotective effect of breviscapine: inhibition of apoptosis in H9c2 cardiomyocytes via the PI3K/Akt/eNOS pathway following simulated ischemia/reperfusion injury.

Breviscapine (BE) is a standardized Chinese herbal medicine extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. It has been widely used to treat cardiovascular and cerebrovascular diseases. However, there are no reports on the protective effects and underlying molecular mechanisms of BE action on myocardial ischemia/reperfusion (MI/R)-induced cardiomyocyte apoptosis. In the present study, we aimed to confirm the cardioprotective effect of BE from MI/R injury in vivo, and investigate the potential molecular mechanisms against simulated ischemia/reperfusion (SI/R)-induced cardiomyocyte apoptosis in vitro. The rat model of MI/R injury was induced by 30 min of transient vessel occlusion followed by 3 h of reperfusion. BE significantly reduced the myocardium infarct size and production of cardiac troponin (cTnl) in serum. In an in vitro experiment, H9c2 cardiomyocytes were incubated with vehicle or ischemic buffer during hypoxia; then, they were reoxygenated with or without BE. BE markedly improved the cell viability and decreased lactate dehydrogenase (LDH) release. We confirmed the anti-apoptotic effect of BE with the Hoechst 33258 staining assay, and this effect was associated with an increase in Bcl-2 and a decrease in active caspase-3 expression. Western blot analysis also showed that BE increased the phosphorylation of Akt and eNOS in H9c2 cells, and the protective effects of BE were partially inhibited by the phosphatidylinositol 3'-kinase (PI3K) specific inhibitor LY294002. Our results suggested that BE could provide significant cardioprotection against MI/R injury, and the potential mechanisms might involve suppression of cardiomyocyte apoptosis through activating the PI3K/Akt/eNOS signaling pathway.

Twist contributes to proliferation and epithelial-to-mesenchymal transition-induced fibrosis by regulating YB-1 in human peritoneal mesothelial cells.

Twist is overexpressed in high glucose (HG) damage of human peritoneal mesothelial cells (HPMCs) in vitro. Herein, we further identified its precise function related to fibrosis of peritoneal membranes (PMs). The overexpression and activation of Twist and YB-1 (official name, YBX1) and a transformed fibroblastic phenotype of HPMCs were found to be positively related to epithelial-mesenchymal transition progress and PM fibrosis ex vivo in 93 patients who underwent continuous ambulatory peritoneal dialysis (PD), and also in HG-induced immortal HPMCs and an animal model of PD. Evidence from chromatin immunoprecipitation and luciferase reporter assays supported that YBX1 is transcriptionally regulated by the direct binding of Twist to E-box. Overexpression of Twist and YB-1 led to an increase in epithelial-mesenchymal transition, proliferation, and cell cycle progress of HPMCs, which might contribute to PM fibrosis. In contrast, the silencing of Twist or YB-1 inhibited HG-induced growth and cell cycle progression of HPMCs; this led to a down-regulation in the expression of cyclin Ds and cyclin-dependent kinases, finally inhibiting PM fibrosis. Twist contributes to PM fibrosis during PD treatment, mainly through regulation of YB-1.

Serum response factor accelerates the high glucose-induced Epithelial-to-Mesenchymal Transition (EMT) via snail signaling in human peritoneal mesothelial cells.

BACKGROUND: Epithelial-to-Mesenchymal Transition (EMT) induced by glucose in human peritoneal mesothelial cells (HPMCs) is a major cause of peritoneal membrane (PM) fibrosis and dysfunction. METHODS: To investigate serum response factor (SRF) impacts on EMT-derived fibrosis in PM, we isolated HPMCs from the effluents of patients with end-stage renal disease (ESRD) to analyze alterations during peritoneal dialysis (PD) and observe the response of PM to SRF in a rat model. RESULTS: Our results demonstrated the activation and translocation of SRF into the nuclei of HPMCs under extensive periods of PD. Accordingly, HPMCs lost their epithelial morphology with a decrease in E-cadherin expression and an increase in α-smooth muscle actin (α-SMA) expression, implying a transition in phenotype. PD with 4.25% glucose solution significantly induced SRF up-regulation and increased peritoneal thickness. In immortal HPMCs, high glucose (HG, 60 mmol/L) stimulated SRF overexpression in transformed fibroblastic HPMCs. SRF-siRNA preserved HPMC morphology, while transfection of SRF plasmid into HPMCs caused the opposite effects. Evidence from electrophoretic mobility shift, chromatin immunoprecipitation and reporter assays further supported that SRF transcriptionally regulated Snail, a potent inducer of EMT, by directly binding to its promoter. CONCLUSIONS: Our data suggested that activation of SRF/Snail pathway might contribute to the progressive PM fibrosis during PD.

Twist overexpression promoted epithelial-to-mesenchymal transition of human peritoneal mesothelial cells under high glucose.

BACKGROUND: Long-term peritoneal dialysis (PD) results in functional and structural alterations of the peritoneal membrane. Previous studies have suggested that high glucose (HG) could induce transdifferentiation of peritoneal mesothelial cells into myofibroblasts, but the molecular mechanisms of HG-induced epithelial-to-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs) are unclear. This study was undertaken to elucidate the effects and mechanisms of Twist on HG-induced EMT of HPMCs. METHODS: HPMCs were exposed to 5.6 mM glucose [normal glucose (NG)], 50 mM glucose (HG) or 50 mM glucose with Si-Twist or pcDNA3.1-Twist. Western blot and immuocytochemistry were performed to determine Twist, E-cadherin and α-smooth muscle actin (α-SMA) protein expression. MMP2 and MMP9 were detected by zymography. Rats were daily instilled with PD fluid and lipopolysaccharide (LPS) or sodium chloride during 6 weeks. Histological analyses were carried out in parietal peritoneum. Twist was detected by western blotting. RESULTS: Twist and α-SMA protein and immuocytochemistry were significantly increased in HG-conditioned media compared to NG media. E-cadherin protein was lower in pcDNA3.1-Twist-transfected HPMCs compared to pcDNA3.1 cells. Twist protein was upregulated 12 h after HG stimulation. MMP9 was increased in pcDNA3.1-Twist-transfected HPMCs compared to pcDNA3.1 cells. Exposure of rat peritoneum to PD fluid and LPS resulted in an increase of extracellular matrix deposition. Twist and α-SMA were stained in the PD fluid group and compared to the control group. Twist protein was significantly increased in the PD group. CONCLUSIONS: In conclusion, HG-induced Twist expression might contribute to EMT of HPMCs. Twist may control EMT of HPMCs by regulating MMP9.

RUNX3 mediates suppression of tumor growth and metastasis of human CCRCC by regulating cyclin related proteins and TIMP-1.

Here we presented that the expression of RUNX3 was significantly decreased in 75 cases of clear cell renal cell carcinoma (CCRCC) tissues (p<0.05). Enforced RUNX3 expression mediated 786-O cells to exhibit inhibition of growth, G1 cell-cycle arrest and metastasis in vitro, and to lost tumorigenicity in nude mouse model in vivo. RUNX3-induced growth suppression was found partially to regulate various proteins, including inhibition of cyclinD1, cyclinE, cdk2, cdk4 and p-Rb, but increase of p27(Kip1), Rb and TIMP-1. Therefore, RUNX3 had the function of inhibiting the proliferative and metastatic abilities of CCRCC cells by regulating cyclins and TIMP1.