Neuroprotective effect of lansoprazole against cisplatin-induced brain toxicity: Role of Nrf2/ARE and Akt/P53 signaling pathways.

Cisplatin is a chemotherapeutic agent usually used in treating different patterns of malignancies. One of the significant apparent complications of cisplatin chemotherapy is brain toxicity. The present study was conducted to evaluate the protective effects of lansoprazole on cisplatin-induced cortical intoxication. Thirty-two rats were allocated into four groups (8 rats/group); group I: received only a vehicle for 10 days, group II: lansoprazole was administered (50 mg/kg) via oral gavage for 10 days, group III: On 5th day of the experiment, rats were given cisplatin (10 mg/kg) i.p. once to induce cortical injury. Group IV: rats were given lansoprazole for 5 days before cisplatin and 5 days afterward. Lansoprazole administration significantly improved cisplatin-induced behavioral changes, as evidenced by decreasing the immobility time in forced swimming and open field tests. Besides, lansoprazole improved cortical histological changes, restored cortical redox balance, enhanced Nrf2/ARE expression, cisplatin-induced neuronal apoptosis, and dampened cisplatin inflammation. In addition, lansoprazole modulated cortical Akt/p53 signal. The present work was the first to show that lansoprazole co-administration reduced cortical toxicity in cisplatin-treated rats via multiple signaling pathways. The current findings provided crucial information for developing novel protective strategies to reduce cisplatin cortical toxicity.

Synthesis and Biological Evaluation of Indole-2-Carboxamides with Potent Apoptotic Antiproliferative Activity as EGFR/CDK2 Dual Inhibitors.

The apoptotic antiproliferative actions of our previously reported CB1 allosteric modulators 5-chlorobenzofuran-2-carboxamide derivatives VIIa-j prompted us to develop and synthesise a novel series of indole-2-carboxamide derivatives 5a-k, 6a-c, and 7. Different spectroscopic methods of analysis were used to validate the novel compounds. Using the MTT assay method, the novel compounds were examined for antiproliferative activity against four distinct cancer cell lines. Compounds 5a-k, 6a-c, and 7 demonstrated greater antiproliferative activity against the breast cancer cell line (MCF-7) than other tested cancer cell lines, and 5a-k (which contain the phenethyl moiety in their backbone structure) demonstrated greater potency than 6a-c and 7, indicating the importance of the phenethyl moiety for antiproliferative action. Compared to reference doxorubicin (GI50 = 1.10 µM), compounds 5d, 5e, 5h, 5i, 5j, and 5k were the most effective of the synthesised derivatives, with GI50 ranging from 0.95 µM to 1.50 µM. Compounds 5d, 5e, 5h, 5i, 5j, and 5k were tested for their inhibitory impact on EGFR and CDK2, and the results indicated that the compounds tested had strong antiproliferative activity and are effective at suppressing both CDK2 and EGFR. Moreover, the studied compounds induced apoptosis with high potency, as evidenced by their effects on apoptotic markers such as Caspases 3, 8, 9, Cytochrome C, Bax, Bcl2, and p53.

Targeting KEAP1/Nrf2, AKT, and PPAR-γ signals as a potential protective mechanism of diosmin against gentamicin-induced nephrotoxicity.

AIM: Gentamicin (GM) is an aminoglycoside antibiotic effectively used for severe/life-threatening infections. However, the clinical application of GM is limited by nephrotoxic side effects. Diosmin (DS) is a flavonoid with a wide range of bioactivities. However, its therapeutic potential in GM-induced nephrotoxicity remains unclear. METHODS: Rats received GM (100 mg/kg, i.p.) for 7 days either separately or in combination with oral DS (50 mg/kg). RESULTS: GM injection disrupted kidney function along with oxidant/antioxidant imbalance. Also, GM significantly decreased renal nuclear factor erythroid 2-related factor 2 (Nrf2), glutamyl cysteine synthetase (GCLC), heme oxygenase-1 (HO-1), superoxide dismutase3 (SOD-3), protein kinase B (AKT), and p-AKT expressions along with Kelch-like ECH-associated protein 1 (KEAP1) up-regulation. On the contrary, DS administration significantly attenuated GM-induced kidney dysfunction and restored kidney oxidant/antioxidant status. In addition, co-treatment with DS plus GM significantly enhanced Nrf2, GCLC, HO-1, SOD3, AKT, and p-AKT expressions along with KEAP1 down-regulation. Additionally, GM-treated rats exhibited a significant decrease in the expressions of renal peroxisome-proliferator activated receptor-gamma (PPAR-γ) and this reduction was alleviated by DS treatment. Furthermore, histopathological findings demonstrated that DS significantly reduced the GM-induced histological abrasions. Besides, an in-silico study was conducted to confirm our biochemical results. Interestingly, in-silico results strongly supported our biochemical investigation by studying the binding affinity of DS to KEAP1, AKT, and PPAR-γ proteins. SIGNIFICANCE: DS could be a promising protective agent against GM-induced nephrotoxicity through targeting of KEAP1/Nrf2/ARE, AKT, and PPAR-γ signaling pathways.

Nephroprotective effect of umbelliferone against cisplatin-induced kidney damage is mediated by regulation of NRF2, cytoglobin, SIRT1/FOXO-3, and NF- kB-p65 signaling pathways.

Cisplatin (Cis) is one of the most potent and effective broad-spectrum antitumor drugs, but its use is limited due to nephrotoxicity. The current study investigated the renoprotective effect of umbelliferone (UMB) on Cis-induced nephrotoxicity in rats. Renal injury was induced by a single injection of Cis (7 mg/kg, ip). Our results exhibited that the injection of Cis significantly disrupted renal function biomarkers as well as KIM-1 expression. The expressions of TNF-α, IL-1ß, NF-kB-p65, and IKKß were elevated along with downregulation of IkBα expression. Also, Cis disrupted cellular oxidant/antioxidant balance through the reduction of glutathione (GSH), glutathione-S-transferase (GST), and superoxide dismutase (SOD) levels and elevation of malondialdehyde (MDA) content. On the contrary, the levels of renal function biomarkers, cytokines, NF-kB-p65, IkBα, IKKß, and oxidant/antioxidant status have been improved after UMB treatment. Mechanistically, rats administered Cis only exhibited a significant decrease in NRF2 and cytoglobin expressions as well as the CREB, SIRT1, FOXO-3, and PPAR-γ genes. Treatment with UMB significantly upregulated NRF2 and cytoglobin proteins, as well as effectively increased the expression of CREB, SIRT1, FOXO-3, PPAR-γ, and NRF2 genes. Histopathological findings strongly supported our biochemical results, as evidenced by attenuation of renal hemorrhage, cast diffusion, and inflammatory cell infiltration. Interestingly, UMB significantly enhanced Cis cytotoxicity in both HL-60 and HeLa cells in a dose-dependent manner. Together, our results demonstrated that UMB can protect against Cis-induced nephrotoxicity in normal rats along with the enhancement of its in vitro antitumor activity. These findings suggested that UMB could be used as a potential adjuvant therapy in Cis chemotherapeutic protocols.

Targeting PARP-1 with metronomic therapy modulates MDSC suppressive function and enhances anti-PD-1 immunotherapy in colon cancer.

BACKGROUND: Poly(ADP-ribose) polymerase (PARP) inhibitors (eg, olaparib) are effective against BRCA-mutated cancers at/near maximum tolerated doses by trapping PARP-1 on damaged chromatin, benefitting only small patient proportions. The benefits of targeting non-DNA repair aspects of PARP with metronomic doses remain unexplored. METHODS: Colon epithelial cells or mouse or human bone marrow (BM)-derived-myeloid-derived suppressor cells (MDSCs) were stimulated to assess the effect of partial PARP-1 inhibition on inflammatory gene expression or immune suppression. Mice treated with azoxymethane/four dextran-sulfate-sodium cycles or APCMin/+ mice bred into PARP-1+/- or treated with olaparib were used to examine the role of PARP-1 in colitis-induced or spontaneous colon cancer, respectively. Syngeneic MC-38 cell-based (microsatellite instability, MSIhigh) or CT-26 cell-based (microsatellite stable, MSS) tumor models were used to assess the effects of PARP inhibition on host responses and synergy with anti-Programmed cell Death protein (PD)-1 immunotherapy. RESULTS: Partial PARP-1 inhibition, via gene heterozygosity or a moderate dose of olaparib, protected against colitis-mediated/APCMin -mediated intestinal tumorigenesis and APCMin -associated cachexia, while extensive inhibition, via gene knockout or a high dose of olaparib, was ineffective or aggravating. A sub-IC50-olaparib dose or PARP-1 heterozygosity was sufficient to block tumorigenesis in a syngeneic colon cancer model by modulating the suppressive function, but not intratumoral migration or differentiation, of MDSCs, with concomitant increases in intratumoral T cell function and cytotoxicity, as assessed by granzyme-B/interferon-γ levels. Adoptive transfer of WT-BM-MDSCs abolished the protective effects of PARP-1 heterozygosity. The mechanism of MDSC modulation involved a reduction in arginase-1/inducible nitric oxide synthase/cyclo-oxygenase-2, but independent of PARP-1 trapping on chromatin. Although a high-concentration olaparib or the high-trapping PARP inhibitor, talazoparib, activated stimulator of interferon gene (STING) in BRCA-proficient cells and induced DNA damage, sub-IC50 concentrations of either drug failed to induce activation of the dsDNA break sensor. STING expression appeared dispensable for MDSC suppressive function and was not strictly required for olaparib-mediated effects. Ironically, STING activation blocked human and mouse MDSC function with no additive effects with olaparib. A metronomic dose of olaparib was highly synergistic with anti-PD-1-based immunotherapy, leading to eradication of MSIhigh or reduction of MSS tumors in mice. CONCLUSIONS: These results support a paradigm-shifting concept that expands the utility of PARP inhibitor and encourage testing metronomic dosing of PARP inhibitor to enhance the efficacy of checkpoint inhibitor-based immunotherapies in cancer.

Diosmin enhances the anti-angiogenic activity of sildenafil and pentoxifylline against hepatopulmonary syndrome via regulation of TNF-α/VEGF, IGF-1/PI3K/AKT, and FGF-1/ANG-2 signaling pathways.

Hepatopulmonary syndrome (HPS) is a severe complication of hepatic cirrhosis, which is characterized by hypoxia, intrapulmonary vasodilation, inflammation, and angiogenesis. In this study, we aimed to investigate the regulatory effects of diosmin (DS) on selected phosphodiesterase inhibitors against chronic bile duct ligation (CBDL)-induced HPS. Experimentally, Wistar Albino rats were used and HPS was induced by CBDL for 28 days. DS (100 mg/kg, daily, P.O.), sildenafil (Sild; 10 mg/kg, twice daily, P.O.), and pentoxifylline (PTX; 50 mg/kg, daily, P.O.) were evaluated either alone or in combinations for their anti-angiogenic activity. CBDL significantly altered oxidative stress biomarkers and up-regulated pulmonary mRNA expressions of VEGF, IGF-1, ET-1, iNOS, eNOS, and ANG-2 as well as the protein expressions of vWF, FGF-1, PI3K, AKT, p-AKT, TGF-ß, HYP, MPO activity and circulating TNF-α. Treatment with DS, Sild, PTX, and their combinations significantly attenuated molecular and cellular changes due to CBDL. Improvement of histopathological changes was also observed after drug treatment which further supported our results. Furthermore, DS combination with Sild or PTX exhibited an improvement in HPS in comparison to each drug alone. Collectively, DS can augment the anti-angiogenic activity of Sild and PTX during HPS through regulation of TNF-α/VEGF, IGF-1/PI3K/AKT, and FGF-1/ANG-2 signaling pathways.

PARP inhibition by olaparib or gene knockout blocks asthma-like manifestation in mice by modulating CD4(+) T cell function.

BACKGROUND: An important portion of asthmatics do not respond to current therapies. Thus, the need for new therapeutic drugs is urgent. We have demonstrated a critical role for PARP in experimental asthma. Olaparib, a PARP inhibitor, was recently introduced in clinical trials against cancer. The objective of the present study was to examine the efficacy of olaparib in blocking established allergic airway inflammation and hyperresponsiveness similar to those observed in human asthma in animal models of the disease. METHODS: We used ovalbumin (OVA)-based mouse models of asthma and primary CD4(+) T cells. C57BL/6J WT or PARP-1(-/-) mice were subjected to OVA sensitization followed by a single or multiple challenges to aerosolized OVA or left unchallenged. WT mice were administered, i.p., 1 mg/kg, 5 or 10 mg/kg of olaparib or saline 30 min after each OVA challenge. RESULTS: Administration of olaparib in mice 30 min post-challenge promoted a robust reduction in airway eosinophilia, mucus production and hyperresponsiveness even after repeated challenges with ovalbumin. The protective effects of olaparib were linked to a suppression of Th2 cytokines eotaxin, IL-4, IL-5, IL-6, IL-13, and M-CSF, and ovalbumin-specific IgE with an increase in the Th1 cytokine IFN-γ. These traits were associated with a decrease in splenic CD4(+) T cells and concomitant increase in T-regulatory cells. The aforementioned traits conferred by olaparib administration were consistent with those observed in OVA-challenged PARP-1(-/-) mice. Adoptive transfer of Th2-skewed OT-II-WT CD4(+) T cells reversed the Th2 cytokines IL-4, IL-5, and IL-10, the chemokine GM-CSF, the Th1 cytokines IL-2 and IFN-γ, and ovalbumin-specific IgE production in ovalbumin-challenged PARP-1(-/-)mice suggesting a role for PARP-1 in CD4(+) T but not B cells. In ex vivo studies, PARP inhibition by olaparib or PARP-1 gene knockout markedly reduced CD3/CD28-stimulated gata-3 and il4 expression in Th2-skewed CD4(+) T cells while causing a moderate elevation in t-bet and ifn-γ expression in Th1-skewed CD4(+) T cells. CONCLUSIONS: Our findings show the potential of PARP inhibition as a viable therapeutic strategy and olaparib as a likely candidate to be tested in human asthma clinical trials.

Correlation between PDZK1, Cdc37, Akt and breast cancer malignancy: the role of PDZK1 in cell growth through Akt stabilization by increasing and interacting with Cdc37.

PDZ domain containing 1 (PDZK1) is a scaffold protein that plays a role in the fate of several proteins. Estrogen can induce PDZK1 gene expression; however, our recent report showed that PDZK1 expression in the breast cancer cell line MCF-7 is indirect and involves insulin-like growth factor (IGF)-1 receptor function. Such a relationship was established in cell culture systems and human breast cancer tissues. Here we show that overexpression of PDZK1 promoted an increase in cyclin D1 and enhanced anchorage-independent growth of MCF-7 cells in the absence of 17ß-estradiol, suggesting that PDZK1 harbors oncogenic activity. Indeed, PDKZ1 overexpression enhanced epidermal growth factor receptor (EGFR)-stimulated MEK/ERK1/2 signaling and IGF-induced Akt phosphorylation. PDZK1 appeared to play this role, in part, by stabilizing the integrity of the growth promoting factors Akt, human epidermal growth factor receptor 2 (Her2/Neu) and EGFR. Increased Akt levels occurred via a decrease in the ubiquitination of the kinase. PDZK1 overexpression was associated with resistance to paclitaxel/5-fluorouracil/etoposide only at low concentrations. Although the increased stability of Akt was sensitive to heat shock protein 90 (HSP90) inhibition, increased levels of the cochaperone cell division cycle 37 (Cdc37), as well as its ability to bind PDZK1, appear to play a larger role in kinase stability. Using human tissue microarrays, we show strong positive correlation between PDZK1, Akt and Cdc37 protein levels, and all correlated with human breast malignancy. There were no positive correlations between PDZK1 and Cdc37 at the mRNA levels, confirming our in vitro studies. These results demonstrate a relationship between PDZK1, Akt and Cdc37, and potentially Her2/Neu and EGFR, in breast cancer, representing a new axis that can be targeted therapeutically to reduce the burden of human breast cancer.

Apoptotic DNA fragmentation may be a cooperative activity between caspase-activated deoxyribonuclease and the poly(ADP-ribose) polymerase-regulated DNAS1L3, an endoplasmic reticulum-localized endonuclease that translocates to the nucleus during apoptosis.

Caspase-activated DNase (CAD) is the most favorable candidate for chromatin degradation during apoptosis. Ca(2+)-dependent endonucleases are equally important in internucleosomal DNA fragmentation (INDF), including the PARP-1-regulated DNAS1L3. Despite the elaborate work on these endonucleases, the question of whether these enzymes cooperate during INDF was not addressed. Here, we show a lack of correlation between INDF and CAD expression levels and inactivation by cleavage of its inhibitor (ICAD) during apoptosis. The cells that failed to induce INDF accumulated large amounts of 50-kb breaks, which is suggestive of incomplete chromatin processing. Similarly, INDF was blocked by Ca(2+) chelation without a block in ICAD cleavage or caspase-3 activation, which is consistent with the involvement of CAD in 50-kb DNA fragmentation and its Ca(2+) independence. However, DNAS1L3 expression in INDF-deficient cells promoted INDF during apoptosis and was blocked by Ca(2+) chelation. Interestingly, expression of DNAS1L3 in ICAD-deficient cells failed to promote tumor necrosis factor α-induced INDF but required the coexpression of ICAD. These results suggest a cooperative activity between CAD and DNAS1L3 to accomplish INDF. In HT-29 cells, endogenous DNAS1L3 localized to the endoplasmic reticulum (ER) and translocated to the nucleus upon apoptosis induction but prior to INDF manifestation, making it the first reported Ca(2+)-dependent endonuclease to migrate from the ER to the nucleus. The nuclear accumulation of DNAS1L3, but not its exit out of the ER, required the activity of cysteine and serine proteases. Interestingly, the endonuclease accumulated in the cytosol upon inhibition of serine, but not cysteine, proteases. These results exemplify the complexity of chromatin degradation during apoptosis.