Discovery of a doublecortin-like kinase 1 inhibitor to prevent inflammatory responses in acute lung injury.

Doublecortin-like kinase 1 (DCLK1) is a microtubule-associated protein kinase involved in neurogenesis and human cancer. Recent studies have revealed a novel functional role for DCLK1 in inflammatory signaling, thus positioning it as a novel target kinase for respiratory inflammatory disease treatment. In this study, we designed and synthesized a series of NVP-TAE684-based derivatives as novel anti-inflammatory agents targeting DCLK1. Bio-layer interferometry binding screening and kinase assays of the NVP-TAE684 derivatives led to the discovery of an effective DCLK1 inhibitor (a24), with an IC50 of 179.7 nM. Compound a24 effectively inhibited lipopolysaccharide (LPS)-induced inflammation in macrophages with higher potency than the lead compound. Mechanistically, compound a24 inhibited LPS-induced inflammation by inhibiting DCLK1-mediated IKKß phosphorylation. Furthermore, compound a24 showed in vivo anti-inflammatory activity in an LPS-challenged acute lung injury model. These findings suggest that compound a24 may serve as a novel candidate for the development of DCLK1 inhibitors and a potential therapeutic agent for the treatment of inflammatory diseases.

Isodeoxyelephantopin Inactivates Thioredoxin Reductase 1 and Activates ROS-Mediated JNK Signaling Pathway to Exacerbate Cisplatin Effectiveness in Human Colon Cancer Cells.

Colon cancer is one of the leading causes of cancer-related death in the world. The development of new drugs and therapeutic strategies for patients with colon cancer are urgently needed. Isodeoxyelephantopin (ESI), a sesquiterpene lactone isolated from the medicinal plant Elephantopus scaber L., has been reported to exert antitumor effects on several cancer cells. However, the molecular mechanisms underlying the action of ESI is still elusive. In the present study, we found that ESI potently suppressed cell proliferation in human colon cancer cells. Furthermore, our results showed that ESI treatment markedly increased cellular reactive oxygen species (ROS) levels by inhibiting thioredoxin reductase 1 (TrxR1) activity, which leads to activation of the JNK signaling pathway and eventually cell death in HCT116 and RKO cells. Importantly, we found that ESI markedly enhanced cisplatin-induced cytotoxicity in HCT116 and RKO cells. Combination of ESI and cisplatin significantly increased the production of ROS, resulting in activation of the JNK signaling pathway in HCT116 and RKO cells. In vivo, we found that ESI combined with cisplatin significantly suppressed tumor growth in HCT116 xenograft models. Together, our study provide a preclinical proof-of-concept for ESI as a potential strategy for colon cancer treatment.

Inhibition of high glucose-induced inflammation and fibrosis by a novel curcumin derivative prevents renal and heart injury in diabetic mice.

Hyperglycemia-induced inflammation and fibrosis have important roles in the pathogenesis of diabetic nephropathy and cardiomyopathy. With inflammatory cytokines and signaling pathways as important mediators, targeting inflammation may be an effective approach to new avenue for treating diabetic complications. J17, a molecule with structural similarities to curcumin, exhibited good anti-inflammatory activities by inhibiting LPS-induced inflammatory response in macrophages. However, its ability to alleviate hyperglycemia-induced injury via its anti-inflammatory actions remained unclear. Thus, we reported that J17 exerts significant inhibitory effects on hyperglycemia-induced inflammation and fibrosis in NRK-52E cells, H9C2 cells and a streptozotocin-induced diabetic mouse model. We also found that the anti-inflammatory and anti-fibrosis activities of J17 are associated with the inhibition of the P38 and AKT signal pathway, respectively. In vivo oral administration of J17 suppressed hyperglycemia-induced inflammation, hypertrophy and fibrosis, thereby reducing key markers for renal and cardiac dysfunction and improving in fibrosis and pathological changes in both renal and cardiac tissues of diabetic mice. The results of this study indicated that J17 can be potentially used as a cardio- and reno-protective agent and that targeting the P38 and AKT pathways may be an effective therapeutic strategy for diabetic complications.

A novel STAT3 inhibitor HO-3867 induces cell apoptosis by reactive oxygen species-dependent endoplasmic reticulum stress in human pancreatic cancer cells.

Pancreatic cancer is the most commonly diagnosed malignancy among solid tumors and has shown an increasing trend year by year. Thus, there is an urgent need for the discovery of new anticancer drugs for the treatment of pancreatic cancer. In recent years, it has been reported that the compound HO-3867, a novel analog of the natural product curcumin, showed antitumor activity with low toxicity. However, the underlying mechanism of this compound's attack on cancer cells is not very clear. In the present study, it was found that HO-3867 showed good antitumor activity at the concentration of 2 µmol/l in PANC-1 and BXPC-3 cells. Importantly, it was also found that HO-3867 treatment significantly induced reactive oxygen species (ROS) production in human pancreatic cancer cell lines, inducing PANC-1 and BXPC-3 cells. Co-treatment with the ROS scavenger, N-acetyl cysteine, partially abrogated HO-3867-induced cell apoptosis. The activation of mitogen-activated protein kinase and endoplasmic reticulum stress indicated a downstream event of ROS generation in mediating the anticancer effect of the HO-3867. In addition, independent of the ROS pathway, direct STAT3 inhibition was observed in HO-3867-induced cell apoptosis. Taken together, the results of this work suggest that both the ROS-dependent ER stress and STAT3 pathways were implicated in the cell apoptosis induced by the novel compound HO-3867.

Inhibition of inflammation and oxidative stress by an imidazopyridine derivative X22 prevents heart injury from obesity.

Inflammation and oxidative stress plays an important role in the development of obesity-related complications and cardiovascular disease. Benzimidazole and imidazopyridine compounds are a class of compounds with a variety of activities, including anti-inflammatory, antioxidant and anti-cancer. X22 is an imidazopyridine derivative we synthesized and evaluated previously for anti-inflammatory activity in lipopolysaccharide-stimulated macrophages. However, its ability to alleviate obesity-induced heart injury via its anti-inflammatory actions was unclear. This study was designed to evaluate the cardioprotective effects of X22 using cell culture studies and a high-fat diet rat model. We observed that palmitic acid treatment in cardiac-derived H9c2 cells induced a significant increase in reactive oxygen species, inflammation, apoptosis, fibrosis and hypertrophy. All of these changes were inhibited by treatment with X22. Furthermore, oral administration of X22 suppressed high-fat diet-induced oxidative stress, inflammation, apoptosis, hypertrophy and fibrosis in rat heart tissues and decreased serum lipid concentration. We also found that the anti-inflammatory and anti-oxidative actions of X22 were associated with Nrf2 activation and nuclear factor-kappaB (NF-κB) inhibition, respectively, both in vitro and in vivo. The results of this study indicate that X22 may be a promising cardioprotective agent and that Nrf2 and NF-κB may be important therapeutic targets for obesity-related complications.

Synthesis of novel thiazolyl-pyrimidines and their anticancer activity in vitro.

A series of novel compounds 7-43 were prepared via the condensation of enaminones 4a-h and the guanidines carbonate 6a-f. The structures of these newly synthesized compounds were confirmed by (1) H-NMR, MS, EA and IR. All the compounds were tested for their cytotoxic activity in vitro against human cancer cell lines including Ishikawa, A549, BEL-7404, SPC-A-01 and SGC-7901. Most of them showed moderate cytotoxic against the tested cell lines. Among them, the most potent compounds 9 and 30 exhibited more efficient activity against Ishikawa, A549.