Upregulated microRNA-485 suppresses apoptosis of renal tubular epithelial cells in mice with lupus nephritis via regulating the TGF-ß-MAPK signaling pathway by inhibiting RhoA expression.

Lupus nephritis (LN) is a common and severe complication of systemic lupus erythematosus. Without intervention, LN may cause acute kidney injury and end-stage renal disease. This study aims to determine whether microRNA-485 (miR-485) affects renal tubular epithelial cells (RTECs) in LN mice via the TGF-ß-MAPK signaling pathway by targeting RhoA. Renal tissue samples were initially extracted from 15 LN and 15 normal mice. RTECs were cultivated in vitro and grouped after transfection of different mimics, inhibitors, or siRNA- RhoA. The target gene of miR-485 was confirmed by dual-luciferase reporter assay. Flow cytometry and MTT assay were applied to detect cell viability and apoptosis. It was determined that RhoA was a target gene of miR-485. We found that urine protein, creatinine, RhoA, interleukin 6 (IL-6), transforming growth factor-ß1 (TGF-ß1), and p38 mitogen-activated protein kinases (p38MAPK) were highly expressed in renal tissues of LN mice, while poor levels of miR-485 were recorded. The overexpression of miR-485 or siRNA- RhoA or the combination of miR-485 and siRNA- RhoA was demonstrated to lead to a reduction of levels of RhoA, IL-6, TGF-ß, and p38MAPK, as well as a promotion of RTECs proliferation and inhibition of RTECs apoptosis. Taken together, these findings indicated that overexpressed miR-485 downregulates RhoA which could promote cell viability and inhibit apoptosis of RTECs by regulating the RhoA-mediated TGF-ß-MAPK signaling pathway in LN mice.

2R,4R-APDC, a Metabotropic Glutamate Receptor Agonist, Reduced Neuronal Apoptosis by Upregulating MicroRNA-128 in a Rat Model After Seizures.

This study aimed to study the protective effect of (2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate (2R,4R-APDC), a selective metabotropic glutamate receptor agonist, against hippocampal neuronal apoptosis induced by seizures in a rat model of pilocarpine-induced epilepsy. The Morris water maze test was used to assess the spatial memory abilities of epileptic rats with or without 2R,4R-APDC treatment. TUNEL assay was performed to examine neuronal apoptosis in hippocampus. Western blot was conducted to evaluate changes in the levels of caspase-3 and caspase-9 in hippocampus. Real-time PCR was used to determine the levels of microRNA-128 (miR-128) in hippocampus. The results of the Morris water maze test showed that the 2R,4R-APDC treatment reduced the escape latencies and swimming lengths of rats after seizures. The TUNEL assay showed that 2R,4R-APDC significantly counteracted seizure-induced cell apoptosis. The western blot confirmed this finding, demonstrating that the levels of cleaved caspase-3 and cleaved caspase-9 were potently decreased by 2R,4R-APDC in rat hippocampus after seizures. In addition, 2R,4R-APDC upregulated miR-128 expression levels in the hippocampus. A miR-128 mimic or inhibitor decreased or increased the percentage of TUNEL-positive cells in rats after seizures and 2R,4R-APDC treatment, respectively. The levels of both cleaved caspase-3 and cleaved caspase-9 were decreased in hippocampus exposed to the miR-128 mimic, whereas they were markedly increased in miR-128 inhibitor-treated hippocampus. In conclusion, 2R,4R-APDC protected hippocampal cells from cell apoptosis after seizures, possibly by upregulating miR-128.

Sevoflurane anesthesia reduces the expression of inflammatory response genes and ß-site amyloid precursor protein-cleaving enzyme in hippocampi of diabetic mice.

Diabetes and inhaled anesthesia are associated with an increased likelihood of developing postoperative cognitive dysfunction in humans and animal models, but the mechanisms are unclear. This study aimed to investigate the effect and mechanism of sevoflurane anesthesia on cognitive function in diabetic (DM) mice. Spontaneously diabetic db/db and control db/m mice were subject to sevoflurane anesthesia or allowed to breathe air, respectively. The Morris water maze test as spatial learning and novel object recognition test as recognition memory were performed. The expression of inflammatory cytokines and neurotoxicity-related genes in the hippocampus of four groups was measured using real-time PCR. The expression level of neurotoxicity and neuroprotection-related proteins in DM mice hippocampus were estimated using Western blot assay. It is found that DM mice developed cognitive impairment; however, the cognitive impairment was not exacerbated in sevoflurane-exposed mice. Sevoflurane anesthesia led to a decrease in mRNA levels of inflammatory cytokines in DM mice hippocampi, including interleukin 17 (IL-17), C-C motif chemokine (CCL20), CCL7 as well as high mobility group box 1 and beta-site amyloid-ß cleaving enzyme 1; and no effect was observed on the expression of neurotoxicity genes, including amyloid precursor protein, choline O-acetyltransferase, tumor necrosis factor, alpha-induced protein 1, B-cell lymphoma 2 and estrogen receptor 2. In addition, we observed elevated phosphorylation of cAMP response element-binding protein in DM mice exposed to sevoflurane anesthesia. In conclusion, sevoflurane did not exacerbate DM-associated cognitive impairment.

Deguelin-induced blockade of PI3K/protein kinase B/MAP kinase signaling in zebrafish and breast cancer cell lines is mediated by down-regulation of fibroblast growth factor receptor 4 activity.

Deguelin, a natural component derived from leguminous plants, has been used as pesticide in some regions. Accumulating evidence show that deguelin has promising chemopreventive and therapeutic activities against cancer cells. This study shows that low concentrations of deguelin can lead to significant delay in zebrafish embryonic development through growth inhibition and induction of apoptosis. Furthermore, we identified fibroblast growth factor receptor 4 (FGFR4) as the putative target of deguelin. The candidate was initially identified by a microarray approach and then validated through in vitro experiments using hormone-responsive (MCF-7) and nonresponsive (MDA-MB-231) human breast cancer cell lines. The results show that deguelin suppressed cell proliferation and induced apoptosis in both cancer cell lines, but not in Hs 578Bst cells, by blocking PI3K/AKT and mitogen-activated protein kinases (MAPK) signaling. The FGFR4 mRNA and protein level also diminished in a dose-dependent manner. Interestingly, we found that forced FGFR4 overexpression attenuated deguelin-induced proliferative suppression and apoptotic cell death in both zebrafish and MCF-7 cell lines, p-AKT and p-ERK levels were restored upon FGFR4 overexpression. Taken together, our results strongly suggest that deguelin inhibition of PI3K/AKT and MAPK signaling in zebrafish and breast cancer cell lines is partially mediated through down-regulation of FGFR4 activity.

Magnetic Nanoparticles of Fe3O4 Enhance Artesunate-inducing Apoptosis of SKM-1 Cells.

OBJECTIVE: To investigate the inhibitory effect of the copolymer of magnetic nanoparticles of Fe(3)O(4) (MNPs-Fe(3)O(4)) and artesunate (ART) on myelodysplastic syndromes (MDS) cell line SKM-1 cells and the potential mechanisms. METHODS: The protein expression levels of BCL-2, BAX, Caspase-3, and Survivin in SKM-1 cells treated with or without the co-polymer were measured by Western blot. The co-polymer-induced apoptosis rate of SKM-1 cells was measured by flow cytometry. RESULTS: The apoptosis rate of SKM-1 cells in the copolymer groups was higher than that in both MNPs-Fe(3)O(4) and artesunate groups alone. The MNPs-Fe(3)O(4) may enhance ART-induced cell apoptosis. Western blot assay showed that the expression of survivin and BCL-2 protein were down-regulated in the ART group, and this down-regulation was even more significant in the group of copolymer of ART with MNPs-Fe(3)O(4). The levels of BAX were increased both in ART group and the copolymer of ART with MNPs-Fe(3)O(4) group, as compared with control group and MNPs-Fe(3)O(4) group. The levels of active-caspase-3 were obviously up-regulated when the ART was combined with the MNPs-Fe(3)O(4). The copolymer of ART with MNPs-Fe(3)O(4) could trigger changes in the expression levels of apoptosis-related genes in SKM-1 cells, among which up-regulation of BAX and down-regulation of survivin and BCL-2 are the 2 major alterations. CONCLUSION: Artesunate can induce the apoptosis of SKM-1 cells, and MNPs-Fe(3)O(4) may enhance the cell apoptosis induced by ART.

[BMMSC from blastic phase CML down-regulate leukemia cell apoptosis].

The purpose of this study was to investigate the effect of bone marrow mesenchymal stem cells (BMMSC) from patients with chronic myeloid leukemia (CML) in blastic phase (Bp) on K562 cells and the primary CML-Bp cells, and to explore its potential mechanisms. K562 cells and primary CML-Bp cells were co-cultured with BMMSC of different groups; the cell proliferation was detected by MTT method, the cell apoptosis rate and mitochondrial membrane potential were measured by flow cytometry, the expression levels of Caspase-8, Caspase-9, and activated Caspase-3 in cells were measured by Western blot. The results showed that the CML-Bp BMMSC could enhance the survival rate of K562 cells treated with adviamycin (ADM) and display protective effect on K562 cells and primary CML-Bp mononuctear cells, inhibited ADM-induced leukimia cell apoptosis (P < 0.05); as compared with CML-chronic phase (CML-Cp) BMMSC and normal BMMSC, the CML-Bp BMMSC showed the highest protective effect on leukemic cells, the mitochondrial membrane potential of co-cultured cells slightly droped (P < 0.05). In the CML-Bp BMMSC cultured with K562 cells, the expression level of caspase-3 was more down-regulated than that in K562 alone plus ADM group, while the expression of caspase-9 significantly increased (P < 0.05). It is concluded that the CML-Bp BMMSC down-regulates ADM-induced leukemia cell appoptosis, its mechanism may relate with the inhibition of mitochondrial membrane potential drop, the stabilization of unactive expression of caspase-9 and down-regulation of caspase-3 expression.

[Inhibitory effects of rapamycin on proliferation of chronic myelogenous leukemia cells and its mechanism].

OBJECTIVE: To explore the inhibitory effects of rapamycin on proliferation of chronic myelogenous leukemia (CML) cells and its possible mechanism. METHODS: The effects of rapamycin at various concentrations on cell proliferation of CML cell line K562 cells were analyzed by MTT. The expressions of mTOR, 4E-BP1 and p70S6K at protein and mRNA level in K562 cells with rapamycin treatment were detected by Western blot and RT-PCR. The protein expressions and phosphorylation of mTOR, 4E-BP1 and p70S6K in primary bone marrow cells from CML patients at chronic phase (CP) were also investigated by Western blot, bone marrow cells from healthy people were used as control. Data were analyzed by the χ(2) test, Fisher's exact test and one-way analysis of variance (ANOVA). RESULTS: The phosphorylation of mTOR, 4E-BP1 and p70S6K were significantly increased in CML bone marrow cells compared with that of normal control (70.6% vs 30.0%, 76.5% vs 40.0%, 73.5% vs 20.0%, respectively, P < 0.05). The proliferation of K562 cells was significantly inhibited with 20 nmol/L and more rapamycin treatment. The phosphorylation of mTOR was decreased after rapamycin treatment, as well as the expressions of 4E-BP1 and p70S6K at protein and mRNA level (P < 0.05). CONCLUSION: mTOR signaling played an important role in CML pathogenesis, and rapamycin could decrease CML cells proliferation by inhibiting the activity of mTOR signaling in vitro.