Amlexanox Exhibits Cardioprotective Effects in 5/6 Nephrectomized Rats

Abstract Cardiorenal syndrome is a life-threatening condition. The aim of the current study was to determine the cardioprotective effects of amlexanox in 5/6 nephrectomized rats. Rats were randomly assigned to three groups: sham, 5/6 nephrectomized rats, and amlexanox-treated 5/6 nephrectomized group. Amlexanox (25 mg/kg/day, i.p.) administration was started just after surgery and continued for 10 weeks. After treatment, kidney function (serum creatinine and urea) and blood pressure (systolic and diastolic) were measured. Heart weight (normalized to tibial length) and fibrosis area percentage were measured. Serum brain natriuretic peptide (BNP, heart failure marker) and cardiac levels of ß1-adrenergic receptor (ß1AR), ß-arrestin-2, phosphatidylinositol-4,5-bisphosphate (PIP2), diacylglycerol (DAG), pS473 Akt (a survival marker), and caspase-3 activity (an apoptosis marker) were also measured. The 5/6 nephrectomy caused renal impairment, cardiac fibrosis, apoptosis, and heart failure indicated by down- regulation of cardiac ß1AR down-stream signals compared with those in the sham group. Interestingly, amlexanox significantly reduced all cardiopathological changes induced after 10 weeks of 5/6 nephrectomy. Amlexanox showed potent cardiac antifibrotic and antiapoptotic effects in 5/6 nephrectomized rats, which were associated with reduced heart failure. To our knowledge, this is the first study that addresses the potent in vivo cardioprotective effects of amlexanox

β-arrestin1 Promotes the Concentration of Mitochondrial Reactive Oxygen in T-ALL Cells via MiR-652-5p / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of β-arrestin1 on the concentration of reactive oxygen species (ROS) in the mitochondria of acute T-lymphocytic leukemia (T-ALL) cells and its possible mechanisms.@*METHODS@#The stable T-ALL cell line with knocked down β-arrestin1 (Jurkat Siβ1) was constructed. Flow cytometry and probe assays were used to detect ROS content in cell and mitochondrial, respectively. The relationship between β-arrestin1 and microRNA was detected, analyzed and Q-PCR confirmed by microRNA microarray. The target genes of microRNA were predicated by miRbase software, identified by Western blot, and validated by Dual luciferase reporter gene.@*RESULTS@#Jurkat Siβ1 stable cell line was successfully constructed and it was found that ROS content was slightly reduced in Jurkat Siβ1 at the whole cell level, and the ROS content was also significantly reduced in mitochondria. MicroRNA microarray analysis revealed that multiple T-ALL related microRNAs showed differentially expressed, in which the expression of miR-652-5p was significantly increased in Jurkat Siβ1 (P2.0), and Q-PCR showed that miR-652-5p was nearly 5-fold up-regulated in Jurkat Siβ1. miRbase predicted that the P62 gene was the target gene of miR-652-5p which could regulates mitochondrial function. P62 protein showed highly expressed in stably knocked down miR-652-5p in Jurkat cells. Dual luciferase reporter gene assay confirms that P62 was the target gene of miR-652-5p.@*CONCLUSION@#β-arrestin1 can decreases the expression of miR-652-5p and deregulates the translational inhibition of P62 mRNA, thus to increase ROS content in mitochondria of T-ALL cells.

β-arrestin1 overexpression suppresses progression of human T-cell acute lymphatic leukemia Molt-4 cell xenograft in mice / 南方医科大学学报

OBJECTIVE@#To investigate the effect of β-arrestin1 overexpression on tumor progression in a NCG mouse model bearing T-cell acute lymphocytic leukemia (T-ALL) Molt-4 cell xenograft.@*METHODS@#Molt-4 cells were tagged with firefly-luciferase (F-Luc) by lentiviral infection, and fluorescence intensity of the cells was detected using a luminescence detector. Molt-4 cell lines with β-arrestin1 overexpression or knockdown were constructed by lentivirus infection and injected the tail vein in sub-lethal irradiated NCG mice. Body weight changes and survival time of the xenografted mice were observed, and the progression of T-ALL in the mice was evaluated using an fluorescence imaging system. Sixteen days after xenografting, the mice were euthanatized and tumor cell infiltration was observed in the slices of the liver and spleen.@*RESULTS@#We successfully tagged Molt-4 cells with F-Luc and overexpressed or knocked down β-arrestin1 in the tagged cells. Bioluminescent imaging showed obvious luminescence catalyzed by F-Luc in Molt-4 cells. After injection of Molt-4-Luc cells into irradiated NCG mice, a gradual enhancement of luminescence in the xenografted mice was observed over time, while the body weight of the mice decreased. Compared with the control mice, the mice xenografted with β-arrestin1-overexpressing Molt-4 cells had significantly prolonged survival time ( < 0.001), while the survival time of the mice xenografted with Molt-4 cells with β- arrestin1 knockdown was significantly shortened ( < 0.001). Histological examination revealed fewer infiltrating tumor cells in the liver and spleen of the mice xenografted with β-arrestin1-overexpressing Molt-4 cells in comparison with the mice bearing parental Molt-4 cell xenografts.@*CONCLUSIONS@#β-arrestin1 overexpression suppresses tumor progression in mice bearing Molt-4 cell xenograft.

β-arrestin 1 Promotes Senescence of Acute Lymphoblastic Leukemia Jurkat Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of β-arrestin1 gene on senescence of T-ALL cells and its possible mechanism.@*METHODS@#The bone marrow specimens of T-ALL patients and controls were collected, the expression of β-arrestin1 and β-arrestin1 in the T-ALL patients was detected by RT-PCR and Western blot, respectively, and the relation of β-arrestin1 expression with the clinical pathologic characteristics and the prognosis of T-ALL patients was analyzed statistically. The stable Jurkat cell line with knocked down or overexpressed β-arrestin1 was constructed, the CCK method was used to detect the Jurkat cell number, the β-gal staining was used to analyze the effect of β-arrestin1 on senescence of Jurkat cells, the cross analysis of RNA-Seg data and KEGG data was performed for screening the possible signaling pathway, and Western blot was performed for varifying the key sites of signaling pathway.@*RESULTS@#The β-arrestin1 expression in specimens of T-ALL patients decreased (P＜0.01), moreover the β-arrestin1 expression negatively related with peripheral blood cell number (r=-0.601), the blasts in peripheral blood (r=-0.516) and extramedullary infiltration (r=-0.359), while positively related with the response to chemotherapy (r=0.393). The detection of stable Jurkat cell line with knocked-down and overexpressed β-arrestin1 found that the β-arrestin 1 could decrease the Jurkat cell number and accelarate the senescence of Jurkat cells (P＜0.05). The cross analysis of RNA-Seg data and KEGG data showed that the senescence of T-ALL cells may be regulated via RAS-P16-PRb-E2F1 by β-arrestin 1. Western bolt confirmed that β-arrestin1 promoted the expression of Ras and p16, and decreased the expression of pRB and E2F1 (P＜0.05).@*CONCLUSIONS@#β-arrestin1 accelerates the senescence of Jurkat cells via Ras-p16-pRb-E2F1, and delays the progression in T-ALL, which may provide a new hypothesis for the pathogenesis of T-ALL.