SGLT2 inhibition ameliorates nano plastics-induced premature endothelial senescence and dysfunction.

Nano plastics (NPs) have been a significant threat to human health and are known to cause premature endothelial senescence. Endothelial senescence is considered one of the primary risk factors contributing to numerous cardiovascular disorders. Recent studies have suggested that inhibition of sodium glucose co-transporter (SGLT2) ameliorates endothelial senescence and dysfunction. Therefore, our study intends to explore the role of SGLT2 in NPs-induced endothelial senescence and dysfunction. Porcine coronary artery and its endothelial cells were treated with NPs in the presence or absence of Enavogliflozin (ENA), a SGLT2 inhibitor and then SGLTs expression, senescence markers and vascular function were evaluated. NPs significantly up-regulated SGLT2 and ENA significantly decreased NPs-induced senescence-associated-ß-gal activity, cell-cycle arrest, and senescence markers p53 and p21 suggesting that inhibition of SGLT2 prevents NPs-induced endothelial senescence. In addition, ENA decreased the formation of reactive oxygen species with the downregulation of Nox2, and p22phox. Furthermore, SGLT2 inhibition also up regulated the endothelial nitric oxide synthase expression along with improving vascular function. In conclusion, premature endothelial senescence by NPs is, at least in part, associated with SGLT2 and it could be a potential therapeutic target for preventing and/or treating environmental pollutants-induced cardiovascular disorders mediated by endothelial senescence and dysfunction.

Pharmacokinetics and Tissue Distribution of Enavogliflozin in Mice and Rats.

This study investigated the pharmacokinetics and tissue distribution of enavogliflozin, a novel sodium-glucose cotransporter 2 inhibitor that is currently in phase three clinical trials. Enavogliflozin showed dose-proportional pharmacokinetics following intravenous and oral administration (doses of 0.3, 1, and 3 mg/kg) in both mice and rats. Oral bioavailability was 84.5-97.2% for mice and 56.3-62.1% for rats. Recovery of enavogliflozin as parent form from feces and urine was 39.3 ± 3.5% and 6.6 ± 0.7%, respectively, 72 h after its intravenous injection (1 mg/kg), suggesting higher biliary than urinary excretion in mice. Major biliary excretion was also suggested for rats, with 15.9 ± 5.9% in fecal recovery and 0.7 ± 0.2% in urinary recovery for 72 h, following intravenous injection (1 mg/kg). Enavogliflozin was highly distributed to the kidney, which was evidenced by the AUC ratio of kidney to plasma (i.e., 41.9 ± 7.7 in mice following its oral administration of 1 mg/kg) and showed slow elimination from the kidney (i.e., T1/2 of 29 h). It was also substantially distributed to the liver, stomach, and small and large intestine. In addition, the tissue distribution of enavogliflozin after single oral administration was not significantly altered by repeated oral administration for 7 days or 14 days. Overall, enavogliflozin displayed linear pharmacokinetics following intravenous and oral administration, significant kidney distribution, and favorable biliary excretion, but it was not accumulated in the plasma and major distributed tissues, following repeated oral administration for 2 weeks. These features may be beneficial for drug efficacy. However, species differences between rats and mice in metabolism and oral bioavailability should be considered as drug development continues.

In Vitro Metabolism of DWP16001, a Novel Sodium-Glucose Cotransporter 2 Inhibitor, in Human and Animal Hepatocytes.

DWP16001 is currently in a phase 2 clinical trial as a novel anti-diabetes drug for the treatment of type 2 diabetes by selective inhibition of sodium-glucose cotransporter 2. This in vitro study was performed to compare the metabolism of DWP16001 in human, dog, monkey, mouse, and rat hepatocytes, and the drug-metabolizing enzymes responsible for the metabolism of DWP16001 were characterized using recombinant human cytochrome 450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes expressed from cDNAs. The hepatic extraction ratio of DWP16001 in five species ranged from 0.15 to 0.56, suggesting that DWP16001 may be subject to species-dependent and weak-to-moderate hepatic metabolism. Five phase I metabolites (M1-M5) produced by oxidation as well as three DWP16001 glucuronides (U1-U3) and two hydroxy-DWP16001 (M1) glucuronides (U4, U5), were identified from hepatocytes incubated with DWP16001 by liquid chromatography-high resolution mass spectrometry. In human hepatocytes, M1, M2, M3, U1, and U2 were identified. Formation of M1 and M2 from DWP16001 was catalyzed by CYP3A4 and CYP2C19. M3 was produced by hydroxylation of M1, while M4 was produced by hydroxylation of M2; both hydroxylation reactions were catalyzed by CYP3A4. The formation of U1 was catalyzed by UGT2B7, but UGT1A4, UGT1A9, and UGT2B7 contributed to the formation of U2. In conclusion, DWP16001 is a substrate for CYP3A4, CYP2C19, UGT1A4, UGT1A9, and UGT2B7 enzymes. Overall, DWP16001 is weakly metabolized in human hepatocytes, but there is a potential for the pharmacokinetic modulation and drug-drug interactions, involved in the responsible metabolizing enzymes of DWP16001 in humans.

Comparative Pharmacokinetics and Pharmacodynamics of a Novel Sodium-Glucose Cotransporter 2 Inhibitor, DWP16001, with Dapagliflozin and Ipragliflozin.

Since sodium-glucose cotransporter 2 (SGLT2) inhibitors reduced blood glucose level by inhibiting renal tubular glucose reabsorption mediated by SGLT2, we aimed to investigate the pharmacokinetics and kidney distribution of DWP16001, a novel SGLT2 inhibitor, and to compare these properties with those of dapagliflozin and ipragliflozin, representative SGLT2 inhibitors. The plasma exposure of DWP16001 was comparable with that of ipragliflozin but higher than that of dapagliflozin. DWP16001 showed the highest kidney distribution among three SGLT2 inhibitors when expressed as an area under curve (AUC) ratio of kidney to plasma (85.0 ± 16.1 for DWP16001, 64.6 ± 31.8 for dapagliflozin and 38.4 ± 5.3 for ipragliflozin). The organic anion transporter-mediated kidney uptake of DWP16001 could be partly attributed to the highest kidney uptake. Additionally, DWP16001 had the lowest half-maximal inhibitory concentration (IC50) to SGLT2, a target transporter (0.8 ± 0.3 nM for DWP16001, 1.6 ± 0.3 nM for dapagliflozin, and 8.9 ± 1.7 nM for ipragliflozin). The inhibition mode of DWP16001 on SGLT2 was reversible and competitive, but the recovery of the SGLT2 inhibition after the removal of SGLT2 inhibitors in CHO cells overexpressing SGLT2 was retained with DWP16001, which is not the case with dapagliflozin and ipragliflozin. In conclusion, selective and competitive SGLT2 inhibition of DWP16001 could potentiate the efficacy of DWP16001 in coordination with the higher kidney distribution and retained SGLT2 inhibition of DWP16001 relative to dapagliflozin and ipragliflozin.

Anticancer activity of undecapeptide analogues derived from antimicrobial peptide, brevinin-1EMa.

In spite of great advances in cancer therapy, cancer remains the major cause of death throughout the world. The increasing resistance of cancer cells towards current anticancer drugs requires development of anticancer agents with a new mode of action. Some antimicrobial peptides have become therapeutic candidates as new anticancer agents. As part of an effort to develop new antimicrobial and/or anticancer agents from natural peptides with low molecular weights, we have investigated the shortest bioactive analogues, which were derived from a 24-residue antimicrobial peptide, Brevinin-1EMa. Recently, we found four bioactive undecapeptides derived from a cationic, amphipathic α-helical, 11-residue peptide (named herein GA-W2: FLGWLFKWASK-NH(2)) (Won et al., 2011). In order to identify the potential of these peptides as anticancer agents, we investigated the anticancer activity of four undecapeptides against seven tumor cell lines such as A498 (kidney), A549 (lung), HCT116 (colon), MKN45 (stomach), PC-3 (prostate), SK-MEL-2 (skin) and SK-OV-3 (ovary). GA-K4 (FLKWLFKWAKK-NH(2)), which had the most potent antimicrobial activity of the four undecapeptides, also exhibited the most potent anticancer activity and synergistic effect in combination with doxorubicin. Therefore, GA-K4 peptide may be a potentially useful candidate as an anticancer peptide agent.

Identification of a novel ubiquitin binding site of STAM1 VHS domain by NMR spectroscopy.

Interaction between the signal-transducing adapter molecule 1 (STAM1) Vps27/Hrs/Stam (VHS) domain and ubiquitin was investigated by nuclear magnetic resonance (NMR) spectroscopy. NMR evidence showed that the structure of STAM1 VHS domain resembles that of other VHS domains, especially the homologous domain of STAM2. We found that the VHS domain binds to ubiquitin via its hydrophobic patch consisting of N-terminus of helix 2 and C-terminus of helix 4 in which Trp26 on helix 2 plays a pivotal role in the binding. The binding between VHS and ubiquitin seems to be very similar to that between ubiquitin associated domain (UBA) and ubiquitin, however, the direction of alpha-helices involved in the ubiquitin binding is opposite. Here, we propose a novel ubiquitin binding site and the manner of ubiquitin recognition of the STAM1 VHS domain.

Simultaneous determination of sildenafil and its active metabolite UK-103,320 in human plasma using liquid chromatography-tandem mass spectrometry.

A liquid chromatography-tandem mass spectrometric method for the simultaneous determination of sildenafil and its active N-demethylated metabolite, UK-103,320 in human plasma was developed. Sildenafil, UK-103,320 and the internal standard (DA-8159) were extracted from human plasma with dichloromethane at basic pH. A reverse-phase LC separation was performed on Luna phenylhexyl column with the mixture of acetonitrile-ammonium formate (10 mM, pH 6.0) (60:40, v/v) as mobile phase. The detection of analytes was performed using an electrospray ionization tandem mass spectrometry in the multiple reaction-monitoring mode. The lower limits of quantification for sildenafil and UK-103,320 were 2.0 ng/ml. The method showed a satisfactory sensitivity, precision, accuracy, recovery and selectivity.