Discovery of oridonin as a novel agonist for BRS-3.

BACKGROUND: Bombesin Receptor Subtype-3 (BRS-3, Bombesin-like receptor, BB3) is an orphan G-protein coupled receptor (GPCR). Recent studies have shown that BRS-3 played a vital role in glucose regulation, insulin secretion, and energy homeostasis. Therefore, discovering more novel exogenous ligands with diverse structures for BRS-3 will be of great importance for target validation and drug development. PURPOSE: In this study, we aim to discover new agonists of BRS-3 from our natural compound libraries, providing a new probe to study the function of BRS-3. STUDY DESIGN: Multiple cell-based assays and in vivo experiments were performed to identify the new ligand. METHODS: BRS-3 overexpression cells were coupled with FLIPR assay, homogeneous time-resolved fluorescence (HTRF) IP-ONE assay, dynamic mass redistribution (DMR) assay, ß-arrestin2 recruitment assay, and western blot to determine receptor activation and downstream signaling events. To further validate the target of BRS-3, a series of in vitro and in vivo experiences were conducted, including glucose uptake, glucose transporter type 4 (GLUT4) transportation in C2C12, and oral glucose tolerance test (OGTT) in mice. RESULTS: We discovered and identified oridonin as a novel small molecule agonist of BRS-3, with a moderate affinity (EC50 of 2.236 × 10-7 M in calcium mobilization assay), specificity, and subtype selectivity. Further in vitro and in vivo tests demonstrated that oridonin exerted beneficial effects in glucose homeostasis through activating BRS-3. CONCLUSIONS: Oridonin, as the discovered new ligand of BRS-3, provides a valuable tool compound to investigate BRS-3's function, especially for target validation in type 2 diabetes and obesity. Oridonin is promising as a lead compound in the treatment of metabolic disorders. Compared to the known agonists of BRS-3, we can take advantage of the multiple reported pharmacological activities of ODN as a natural product and assess whether these pharmacological activities are regulated by BRS-3. This may facilitate the discovery of novel functions of BRS-3.

Benzothiophene-2-carboxamide derivatives as SENPs inhibitors with selectivity within SENPs family.

The SUMO (small ubiquitin-related modifier)-specific proteases (SENPs) are responsible for the cleavage of SUMO from its target proteins, thus play important roles in the dynamic SUMOylation and deSUMOylation processes. SENPs are related to a variety of human diseases including cancer and represent a new class of potential therapeutic targets with mechanism of action that is likely to be different from that of current clinically used drugs. However, potent inhibitors that are selective within the SENPs family members still remain a challenge due to their high homology. In order to demonstrate the feasibility of developing selective inhibitors within the SENPs family, we chose SENP1/2/5 as representatives, aiming to identify inhibitors with selectivity among the members. Starting from a hit compound ZCL951 from virtual screening, a series of benzothiophene-2-carboxamide inhibitors were designed based on the protein structures of SENP1, 2, and 5. First, an unoccupied hydrophobic pocket was first identified which led to IC50 as low as 0.56 µM. Furthermore, the ethylacetate 77 gave both submicromolar inhibitory activity and 33-fold selectivity for SENP2 versus SENP5. They are the most potent and selective nonpeptidic inhibitor reported so far for the SENPs family, as far as we are aware. Their structure-activity relationship was also discussed.

Polydopamine Nanoparticles for Deep Brain Ablation via Near-Infrared Irradiation.

Local resection or ablation remains an important approach to treat drug-resistant central neurological disease. Conventional surgical approaches are designed to resect the diseased tissues. The emergence of photothermal therapy (PTT) offers a minimally invasive alternative. However, their poor penetration and potential off-target effect limit their clinical application. Here, polydopamine nanoparticles (PDA-NPs) were prepared and characterized. Studies were performed to evaluate whether PDA-NPs combined with near-infrared (NIR) light can be used to ablate deep brain structures in vitro and in vivo. PDA-NPs were prepared with a mean diameter of ∼150 nm. The particles show excellent photothermal conversion efficiency. PDA-NPs did not show remarkable cytotoxicity against neuronal-like SH-SY5Y cell lines. However, it can cause significant cell death when combined with NIR irradiation. Transcranial NIR irradiation after PDA-NPs administration induced enhanced local hyperthermia as compared with NIR alone. Local temperature exceeded 60 °C after 6 min of irradiation plus PDA while it can only reach 48 °C with NIR alone. PTT with PDA (10 mg/mL, 3 µL) and NIR (1.5 W/cm2) can ablate deep brain structures precisely with an ablation volume of ∼6.5 mm3. Histological analysis confirmed necrosis and apoptosis in the targeted area. These results demonstrate the potential of NP-assisted PTT for the treatment against nontumorous central neurological diseases.

Efficacy and safety of long-term treatment with statins for coronary heart disease: A Bayesian network meta-analysis.

BACKGROUND AND AIMS: Our study aims to evaluate the efficacy and safety of long-term treatment of statins for coronary heart disease (CHD). METHODS: Efficacy outcomes included changes in blood lipids, risk of CHD mortality and all-cause mortality. Safety outcomes were evaluated by the risk of adverse events (AE). Bayesian network meta-analysis was used to compare the direct and indirect effects between different statins. RESULTS: The systematic review showed that levels of blood lipids decreased during statin treatment. High dose of atorvastatin was the most obvious treatment for the reduction of blood lipids. Network meta-analysis showed that statins were significantly more effective than the control in reducing the risk of CHD mortality (Odds Ratio (OR) 0.69, 95% CI 0.61-0.77) and all-cause mortality (OR 0.84, 95% CI 0.80-0.87). In terms of reducing the risk of CHD morality, fluvastatin (77.3%), atorvastatin (72.3%) and lovastatin (68.4%) had higher cumulative probability than other statins, which were more effective treatments for the reduction of CHD morality. In terms of reducing all-cause mortality, atorvastatin (78.6%), fluvastatin (77.1%) and pitavastatin (74.1%) had higher cumulative probability than other statins, which were more effective treatment for reducing the all-cause mortality. Compared with placebo, statins increased the incidence risk of muscle disease (OR 1.05, 95% CI 1.00-1.10) and kidney disease (OR 1.11, 95% CI 1.05-1.72). CONCLUSIONS: Statins significantly reduced levels of blood lipids, with a high dose of atorvastatin being the most effective in blood-lipid level modification. Statins reduced the risk of CHD mortality and all-cause mortality, with atorvastatin and fluvastatin being the most effective in reducing the risk of CHD mortality and all-cause mortality. Statins increased the risk of muscle disease and kidney damage.

Identification of SENP1 inhibitors through in silico screening and rational drug design.

The small ubiquitin-related modifier (SUMO)-specific proteases (SENPs) catalyze the deconjugation of SUMO from their substrate proteins. SENP1 which is the most studied isoform is closely related to many cancers such as prostate cancer and colon cancer, thus representing a potential therapeutic target for cancer treatment. In the present study, we identified eleven SENP1 inhibitors representing a variety of scaffolds through in silico screening. Based on these scaffolds, a series of new compounds were designed and synthesized in order to improve their SENP1 inhibitory potency. As a result, compounds with IC50 as low as 3.5 µM (compound 13m) were obtained and a preliminary structure-activity relationship was discussed.

Effects of Tongxinluo on myocardial fibrosis in diabetic rats.

BACKGROUND: The aim of this study was to explore the effect of Tongxinluo on myocardial fibrosis in diabetic rats and its possible mechanism of action. METHODS: Diabetic rat models were established and then divided into three groups: control, diabetes, and Tongxinluo groups. Heart function and myocardial interstitial collagen volume fraction were investigated, and the protein and mRNA expression levels of transforming growth factor beta 1 (TGF-ß1), Smad3, and Smad7 were measured. RESULTS: Heart function was clearly abnormal in the diabetes group compared with that in the control group, and the collagen volume fraction and mRNA expression levels of TGF-ß1 and Smad3 were higher. However, the protein and mRNA expression levels of Smad7 were lower. In the Tongxinluo group, it was observed that these indicators were improved. CONCLUSION: Tongxinluo was effective for the prevention and treatment of myocardial fibrosis in diabetic rats. It probably mediates the expressions of TGF-ß1, Smad3, and Smad7 in rat cardiomyocytes to reduce the occurrence of myocardial fibrosis in diabetic rats.

Small molecule targeting Cdc42-intersectin interaction disrupts Golgi organization and suppresses cell motility.

Signaling through the Rho family of small GTPases has been intensely investigated for its crucial roles in a wide variety of human diseases. Although RhoA and Rac1 signaling pathways are frequently exploited with the aid of effective small molecule modulators, studies of the Cdc42 subclass have lagged because of a lack of such means. We have applied high-throughput in silico screening and identified compounds that are able to fit into the surface groove of Cdc42, which is critical for guanine nucleotide exchange factor binding. Based on the interaction between Cdc42 and intersectin (ITSN), a specific Cdc42 guanine nucleotide exchange factor, we discovered compounds that rendered ITSN-like interactions in the binding pocket. By using in vitro binding and imaging as well as biochemical and cell-based assays, we demonstrated that ZCL278 has emerged as a selective Cdc42 small molecule modulator that directly binds to Cdc42 and inhibits its functions. In Swiss 3T3 fibroblast cultures, ZCL278 abolished microspike formation and disrupted GM130-docked Golgi structures, two of the most prominent Cdc42-mediated subcellular events. ZCL278 reduces the perinuclear accumulation of active Cdc42 in contrast to NSC23766, a selective Rac inhibitor. ZCL278 suppresses Cdc42-mediated neuronal branching and growth cone dynamics as well as actin-based motility and migration in a metastatic prostate cancer cell line (i.e., PC-3) without disrupting cell viability. Thus, ZCL278 is a small molecule that specifically targets Cdc42-ITSN interaction and inhibits Cdc42-mediated cellular processes, thus providing a powerful tool for research of Cdc42 subclass of Rho GTPases in human pathogenesis, such as those of cancer and neurological disorders.

Design, synthesis, and biological evaluation of benzodiazepine-based SUMO-specific protease 1 inhibitors.

As the best-characterized ubiquitin-like protein (UBL), small ubiquitin-related modifier (SUMO) was found to conjugate with a number of proteins to regulate cellular functions including transcription, signal transduction, and cell cycle. While E1, E2 and E3 ligases are responsible for the forward SUMOylation reaction, SUMO-specific proteases (SENPs) reversibly remove SUMO from the SUMOylated proteins. Recently, SENP1 was found to be a potential therapeutic target for the treatment of prostate cancers, but the design and synthesis of its inhibitors have not been reported. We designed and synthesized a series of benzodiazepine-based SENP1 inhibitors, and they showed inhibitory activity as good as IC(50)=9.2µM (compound 38). The structure-activity relationship was also discussed.