On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective.

Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10's of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation.

Republication: Targeting PI3KC2ß Impairs Proliferation and Survival in Acute Leukemia, Brain Tumours and Neuroendocrine Tumours.

BACKGROUND: Eight human catalytic phosphoinositide 3-kinase (PI3K) isoforms exist which are subdivided into three classes. While class I isoforms have been well-studied in cancer, little is known about the functions of class II PI3Ks. MATERIALS AND METHODS: The expression pattern and functions of the class II PI3KC2ß isoform were investigated in a panel of tumour samples and cell lines. RESULTS: Overexpression of PI3KC2ß was found in subsets of tumours and cell lines from acute myeloid leukemia (AML), glioblastoma multiforme (GBM), medulloblastoma (MB), neuroblastoma (NB), and small cell lung cancer (SCLC). Specific pharmacological inhibitors of PI3KC2ß or RNA interference impaired proliferation of a panel of human cancer cell lines and primary cultures. Inhibition of PI3KC2ß also induced apoptosis and sensitised the cancer cells to chemotherapeutic agents. CONCLUSION: Together, these data show that PI3KC2ß contributes to proliferation and survival in AML, brain tumours and neuroendocrine tumours, and may represent a novel target in these malignancies.

Spectrally blue hydrated parent body of asteroid (162173) Ryugu.

Ryugu is a carbonaceous rubble-pile asteroid visited by the Hayabusa2 spacecraft. Small rubble pile asteroids record the thermal evolution of their much larger parent bodies. However, recent space weathering and/or solar heating create ambiguities between the uppermost layer observable by remote-sensing and the pristine material from the parent body. Hayabusa2 remote-sensing observations find that on the asteroid (162173) Ryugu both north and south pole regions preserve the material least processed by space weathering, which is spectrally blue carbonaceous chondritic material with a 0-3% deep 0.7-µm band absorption, indicative of Fe-bearing phyllosilicates. Here we report that spectrally blue Ryugu's parent body experienced intensive aqueous alteration and subsequent thermal metamorphism at 570-670 K (300-400 °C), suggesting that Ryugu's parent body was heated by radioactive decay of short-lived radionuclides possibly because of its early formation 2-2.5 Ma. The samples being brought to Earth by Hayabusa2 will give us our first insights into this epoch in solar system history.

Synthesis and structure-activity relationship of fused-pyrimidine derivatives as a series of novel GPR119 agonists.

A series of fused-pyrimidine derivatives have been discovered as potent and orally active GPR119 agonists. A combination of the fused-pyrimidine structure and 4-chloro-2,5-difluorophenyl group provided the 5,7-dihydrothieno[3,4-d]pyrimidine 6,6-dioxide derivative 14a as a highly potent GPR119 agonist. Further optimization of the amino group at the 4-position in the pyrimidine ring led to the identification of 2-{1-[2-(4-chloro-2,5-difluorophenyl)-6,6-dioxido-5,7-dihydrothieno[3,4-d]pyrimidin-4-yl]piperidin-4-yl}acetamide (16b) as an advanced analog. Compound 16b was found to have extremely potent agonistic activity and improved glucose tolerance at 0.1 mg/kg po in mice. We consider compound 16b and its analogs to have clear utility in exploring the practicality of GPR119 agonists as potential therapeutic agents for the treatment of type 2 diabetes mellitus.

A chemically programmed antibody is a long-lasting and potent inhibitor of influenza neuraminidase.

Programming an anti-flu strategy: A new and potent neuraminidase inhibitor that maintains long-term systemic exposure of an antibody and the therapeutic activity of the neuraminadase inhibitor zanamivir has been created. This strategy could provide a promising new class of influenza A drugs for therapy and prophylaxis, and validates enzyme inhibitors as programming agents in synthetic immunology.

Targeting PI3KC2ß impairs proliferation and survival in acute leukemia, brain tumours and neuroendocrine tumours.

BACKGROUND: Eight human catalytic phosphoinositide 3-kinase (PI3K) isoforms exist which are subdivided into three classes. While class I isoforms have been well-studied in cancer, little is known about the functions of class II PI3Ks. MATERIALS AND METHODS: The expression pattern and functions of the class II PI3KC2ß isoform were investigated in a panel of tumour samples and cell lines. RESULTS: Overexpression of PI3KC2ß was found in subsets of tumours and cell lines from acute myeloid leukemia (AML), glioblastoma multiforme (GBM), medulloblastoma (MB), neuroblastoma (NB), and small cell lung cancer (SCLC). Specific pharmacological inhibitors of PI3KC2ß or RNA interference impaired proliferation of a panel of human cancer cell lines and primary cultures. Inhibition of PI3KC2ß also induced apoptosis and sensitised the cancer cells to chemotherapeutic agents. CONCLUSION: Together, these data show that PI3KC2ß contributes to proliferation and survival in AML, brain tumours and neuroendocrine tumours, and may represent a novel target in these malignancies.

Synthesis and evaluation of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety as selective ß3-adrenergic receptor agonists.

In the search for potent and selective human ß3-adrenergic receptor (AR) agonists as potential drugs for use in treating obesity and non-insulin dependent (type 2) diabetes, a series of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety were prepared and their biological activities against human ß3-, ß2-, and ß1-ARs were evaluated. Among these compounds, N-phenyl-(2-phenylaminothiazol-4-yl)acetamide (4 g), N-phenyl-(2-benzylaminothiazol-4-yl)acetamide (4j), and N-phenyl-[2-(3-methoxyphenyl)aminothiazol-4-yl]acetamide (6g) derivatives showed potent agonistic activity against the ß3-AR with functional selectivity over the ß1- and ß2-ARs. In addition, these compounds exhibited significant hypoglycemic activity in a rodent model of diabetes.

Synthesis and evaluation of novel phenylethanolamine derivatives containing acetanilides as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential pharmacotherapies for the treatment of obesity and non-insulin dependent (type II) diabetes, we prepared a novel series of phenylethanolamine derivatives containing acetanilides and evaluated their biological activities at the human beta3-, beta2-, and beta1-ARs. Among these compounds, the 6-amino-2-pyridylacetanilide (36b), 2-amino-5-methylthiazol-4-ylacetanilide (36g), and 5-amino-1,2,4-thiadiazol-3-ylacetanilide (36h) derivatives showed potent agonistic activity at the beta3-AR with functional selectivity over the beta1- and beta2-ARs. In addition, these compounds exhibited significant hypoglycemic activity in a rodent diabetic model.

Antihyperglycemic effects of ASP8497 in streptozotocin-nicotinamide induced diabetic rats: comparison with other dipeptidyl peptidase-IV inhibitors.

(2S,4S)-4-Fluoro-1-({[4-methyl-1-(methylsulfonyl)piperidin-4-yl]amino}acetyl)pyrrolidine-2-carbonitrile monofumarate (ASP8497) is a novel dipeptidyl peptidase (DPP)-IV inhibitor. In this study, we investigated the antidiabetic potency, mechanism, and duration of action of ASP8497 both in vitro and in vivo, and compared it with the DPP-IV inhibitors vildagliptin, sitagliptin, and saxagliptin. ASP8497 inhibited rat plasma DPP-IV activity in vitro with an IC(50) value of 2.96 nmol/l, while those for vildagliptin, sitagliptin, and saxagliptin were 2.12, 8.98, and 2.00 nmol/l, respectively. In rats that had streptozotocin-nicotinamide-induced, mildly diabetes, oral administration of ASP8497 dose-dependently and sustainably inhibited plasma DPP-IV activity. In addition, ASP8497 dose-dependently and significantly improved glucose tolerance with a concomitant increase in plasma glucagon-like peptide 1 (GLP-1) and insulin levels at both 0.5 h and 8 h after dosing. The order of both potency and duration of action for plasma DPP-IV inhibition and glucose tolerance improvement was as follows: saxagliptin > ASP8497 = vildagliptin = sitagliptin. These results suggest that ASP8497 exerts a potent and long-acting DPP-IV inhibitory effect and improves glucose tolerance through glucose-dependent insulinotropic action via elevation of the GLP-1 level in streptozotocin-nicotinamide-induced mildly diabetic rats. This compound is expected to be useful as a therapeutic agent for impaired glucose tolerance and type 2 diabetes.

Discovery of novel thiourea derivatives as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, we prepared a novel series of phenoxypropanolamine derivatives containing the thiourea moiety and evaluated their biological activities at human beta3-, beta2-, and beta1-ARs. Among these compounds, 4-nitrophenylthiourea (18i) and 3-methoxyphenylthiourea (18k) derivatives were found to exhibit potent agonistic activity at the beta3-AR, with EC(50) values of 0.10 and 0.16 microM, respectively, and no agonistic activity for either the beta1- or beta2-AR. In addition, they showed significant hypoglycemic activity in a rodent diabetic model.

Synthesis and evaluation of novel phenoxypropanolamine derivatives containing acetanilides as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, a novel series of phenoxypropanolamine derivatives containing acetanilides were prepared and their biological activities were evaluated at the human beta3-, beta2-, and beta1-ARs. Several of the analogues (21a, 21b, and 27a) exhibited potent agonistic activity at the beta3-AR. Among the compounds described herein, the N-methyl-1-benzylimidazol-2-ylacetanilide derivative (21b) was found to be the most potent and selective beta3-AR agonist, with an EC(50) value of 0.28 microM and no agonistic activity for either the beta1- or beta2-AR. In addition, 21b showed significant hypoglycemic activity in a rodent diabetic model.

Antidiabetic effects of dipeptidyl peptidase-IV inhibitors and sulfonylureas in streptozotocin-nicotinamide-induced mildly diabetic mice.

The present study investigated the antidiabetic effects of the dipeptidyl peptidase (DPP)-IV inhibitors ASP8497 and vildagliptin, and the sulfonylureas glibenclamide and gliclazide in streptozotocin-nicotinamide-induced mildly diabetic mice. A single administration of ASP8497 and vildagliptin significantly improved glucose tolerance by increasing plasma insulin and glucagon-like peptide-1 levels. In addition, a single administration of glibenclamide and gliclazide also caused significant improvement in glucose tolerance with an accompanying increase in the plasma insulin level. Subsequently, the effects of a 1-week chronic daily dosing of DPP-IV inhibitors and sulfonylureas were investigated. All drugs significantly improved glucose tolerance on day 1 of chronic daily dosing. After 1 week of chronic daily dosing, the DPP-IV inhibitors caused a significant improvement in glucose tolerance similar to those observed on day 1 by increasing the plasma insulin and glucagon-like peptide-1 levels. In contrast, the sulfonylureas had no significant improving or insulinotropic effect. Furthermore, ASP8497 also had an antihyperglycemic effect and improved pancreatic histopathologic lesions in a 4-week chronic daily dosing study. These results suggest that chronic daily dosing of sulfonylureas had virtually no antidiabetic effects because of marked attenuation of the insulinotropic action in streptozotocin-nicotinamide-induced mildly diabetic mice. In contrast, the antidiabetic efficacy of DPP-IV inhibitors, including ASP8497, did not change even after chronic daily dosing; therefore, DPP-IV inhibitors are useful as a therapeutic agent for impaired glucose tolerance and type 2 diabetes mellitus.

Discovery of novel acetanilide derivatives as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, a novel series of acetanilide-based analogues were prepared and their biological activities were evaluated at the human beta3-, beta2-, and beta1-ARs. Among these compounds, 2-pyridylacetanilide (2f), pyrimidin-2-ylacetanilide (2u), and pyrazin-2-ylacetanilide (2v) derivatives exhibited potent agonistic activity at the beta3-AR with functional selectivity over the beta1- and beta2-ARs. In particular, compound 2u was found to be the most potent and selective beta3-AR agonist with an EC(50) value of 0.11 microM and no agonistic activity for either the beta1- or beta2-AR. In addition, 2f, 2u, and 2v showed significant hypoglycemic activity in a rodent diabetic model.

Effects of the combination of dipeptidyl peptidase-IV inhibitor ASP8497 and antidiabetic drugs in streptozotocin-nicotinamide-induced mildly diabetic mice.

Several combination therapies have been investigated in an effort to achieve and maintain glycemic control in patients with type 2 diabetes. In this study, we combined the novel dipeptidyl peptidase (DPP)-IV inhibitor ASP8497 with the antidiabetic drugs metformin, glibenclamide, voglibose, rosiglitazone, and insulin to examine the effects of each combination on glucose tolerance in streptozotocin-nicotinamide-induced mildly diabetic mice. Single treatments with ASP8497 (1 mg/kg), metformin (300 mg/kg), glibenclamide (3 mg/kg), voglibose (0.3 mg/kg), rosiglitazone (10 mg/kg), or insulin (0.2 IU/kg) significantly improved glucose tolerance during the liquid meal tolerance test. In addition, combination treatment with ASP8497 and each antidiabetic drug additively improved glucose tolerance. Among these, the combination of ASP8497 and glibenclamide or insulin additively ameliorated glucose tolerance with an additive increase in the plasma insulin level; however, it did not affect the fasting blood glucose lowering effects of glibenclamide or insulin. These profiles indicate that the combination of ASP8497 with existing antidiabetic drugs could be useful for correcting the postprandial hyperglycemia seen with type 2 diabetes.

Evaluation of the antidiabetic effects of dipeptidyl peptidase-IV inhibitor ASP8497 in streptozotocin-nicotinamide-induced mildly diabetic mice.

Gastrointestinal hormone glucagon-like peptide-1 (GLP-1) has a potent glucose-dependent insulinotropic effect and is rapidly degraded by dipeptidyl peptidase (DPP)-IV. Therefore, the use of DPP-IV inhibitors is being actively explored as a novel approach to the treatment of type 2 diabetes. The present study investigated the antidiabetic effects of the DPP-IV inhibitor ASP8497 in streptozotocin-nicotinamide-induced mildly diabetic mice which possess aggravation of glucose tolerance due to loss of early-phase insulin secretion. ASP8497 exhibited good oral bioavailability with potent inhibition of plasma DPP-IV activity. This inhibitory activity lasted up to 24 h when administered at 5 mg/kg twice a day or 10 mg/kg once a day. A single oral administration of ASP8497 (0.3-3 mg/kg) significantly improved glucose tolerance by increasing plasma insulin and GLP-1 levels during the oral glucose or liquid meal tolerance tests. These effects were seen not only immediately, but also 8 h after administration. In contrast, ASP8497 (0.3-10 mg/kg) had no significant effect on blood glucose and plasma insulin levels under fasting conditions. Furthermore, repeated administration of ASP8497 (5 mg/kg twice a day or 10 mg/kg once a day) for 25 days significantly decreased nonfasting blood glucose and HbA(1c) levels. These results suggest that ASP8497 is a potent and long-acting DPP-IV inhibitor that improves glucose tolerance through glucose-dependent insulinotropic action via the elevation of the GLP-1 level in streptozotocin-nicotinamide-induced mildly diabetic mice. It is expected to be useful as a therapeutic agent for impaired glucose tolerance and type 2 diabetes.

Chronic inhibition of dipeptidyl peptidase-IV with ASP8497 improved the HbA(1c) level, glucose intolerance, and lipid parameter level in streptozotocin-nicotinamide-induced diabetic mice.

Dipeptidyl peptidase-IV (DPP-IV) is the primary inactivator of glucoregulatory incretin hormones, and DPP-IV inhibitors are expected to become a useful new class of anti-diabetic agent. The aim of the present study is to characterize the chronic in vivo profile of the DPP-IV inhibitor ASP8497. In streptozotocin-nicotinamide-induced diabetic mice, ASP8497 was administered orally for 3 weeks at 1, 3, or 10 mg/kg once daily, which improved the hemoglobin A(1c), non-fasting plasma insulin, fasting blood glucose levels, glucose intolerance, and lipid profiles (plasma triglyceride, non-esterified fatty acid and total cholesterol) with neutral effect on body weight. The pancreatic insulin content and hepatic phosphoenolpyruvate carboxykinase (PEPCK) activity recovered dose-dependently in ASP8497-treated groups. These results revealed that ASP8497 was successful in improving glycemic control and metabolic parameters in streptozotocin-nicotinamide-induced diabetic mice. It is therefore suggested that ASP8497 may be a potential agent for the treatment of type 2 diabetes.

ASP8497 is a novel selective and competitive dipeptidyl peptidase-IV inhibitor with antihyperglycemic activity.

Dipeptidyl peptidase (DPP)-IV inhibitors are expected to become a useful new class of antidiabetic agent. The aim of the present study is to characterize the in vitro and in vivo profile of ASP8497, (2S,4S)-4-fluoro-1-({[4-methyl-1-(methylsulfonyl)piperidin-4-yl]amino}acetyl)pyrrolidine-2-carbonitrile monofumarate, which is a novel DPP-IV inhibitor. ASP8497 inhibited DPP-IV in plasma from mice, rats, dogs and humans with IC(50) values of 3.86, 2.36, 5.53 and 5.30 nM, respectively. In contrast, ASP8497 did not potently inhibit DPP8 or DPP9 activity (IC(50)>200 nM). Kinetic analysis indicated that ASP8497 inhibits DPP-IV activity in a competitive manner. In streptozotocin-nicotinamide-induced diabetic mice, ASP8497 (3 mg/kg) significantly reduced glucose excursion during the oral glucose tolerance test conducted 0.5 and 8.5 h after administration, with increases in plasma insulin and active glucagon-like peptide-1 (GLP-1) levels. In contrast, ASP8497 (3 and 30 mg/kg) did not cause hypoglycemia in fasted normal mice. Furthermore, administration of exogenous GLP-1 induced significant inhibition of gastric emptying and small intestinal transit rates, but ASP8497 (30 mg/kg) had no significant effects in normal mice. These present preclinical studies indicate that ASP8497 is a novel selective DPP-IV inhibitor with long-acting antidiabetic effect that might be a potential agent for type 2 diabetes.

Pharmacological profile of ASP8497, a novel, selective, and competitive dipeptidyl peptidase-IV inhibitor, in vitro and in vivo.

Dipeptidyl peptidase (DPP)-IV is involved in the inactivation of glucagon-like peptide-1 (GLP-1), a potent insulinotropic peptide. Thus, DPP-IV inhibitors are expected to become a useful new class of antidiabetic agent. This report describes the pharmacological profile of the novel DPP-IV inhibitor, ASP8497 [(2S,4S)-4-fluoro-1-({[4-methyl-1-(methylsulfonyl)piperidin-4-yl]amino}acetyl)pyrrolidine-2-carbonitrile monofumarate], both in vitro and in vivo. ASP8497 inhibited DPP-IV in plasma from mice, dogs, and humans with median inhibition concentration (IC(50)) values of 2.6 nM, 7.3 nM, and 6.2 nM, respectively. In contrast, ASP8497 did not potently inhibit human DPP8 or DPP9 activity (IC(50)=1,700 nM and 100 nM, respectively) and exhibited selectivity against several proteases, including proline-specific proteases (IC(50)>10 microM). Kinetic analysis indicated that ASP8497 is a competitive DPP-IV inhibitor. In normal mice, ASP8497 inhibited plasma DPP-IV activity even 12 h after administration. ASP8497 significantly inhibited increases in the blood glucose level during the oral glucose tolerance test (OGTT) conducted 0.5 h after administration. This was accompanied by increases in the plasma active GLP-1 and insulin levels. In addition, ASP8497 significantly inhibited increases in the blood glucose level during the OGTT conducted 8 h after administration. Furthermore, in Zucker fatty rats, ASP8497 dose dependently improved glucose tolerance with significance at doses of 1 mg/kg or higher. In contrast, ASP8497 did not cause hypoglycemia in fasted normal mice. These results indicate that ASP8497 is a potent, competitive, and selective DPP-IV inhibitor with antihyperglycemic activity.

A selective PIKfyve inhibitor blocks PtdIns(3,5)P(2) production and disrupts endomembrane transport and retroviral budding.

Phosphoinositides have crucial roles in cellular controls, many of which have been established through the use of small-molecule inhibitors. Here, we describe YM201636, a potent inhibitor of the mammalian class III phosphatidylinositol phosphate kinase PIKfyve, which synthesizes phosphatidylinositol 3,5-bisphosphate. Acute treatment of cells with YM201636 shows that the PIKfyve pathway is involved in the sorting of endosomal transport, with inhibition leading to the accumulation of a late endosomal compartment and blockade of retroviral exit. Inhibitor specificity is shown by the use of short interfering RNA against the target, as well as by rescue with the drug-resistant yeast orthologue Fab1. We concluded that the phosphatidylinositol 3,5-bisphosphate pathway is integral to endosome formation, determining morphology and cargo flux.

PIKfyve negatively regulates exocytosis in neurosecretory cells.

Regulated secretion depends upon a highly coordinated series of protein-protein and protein-lipid interactions. Two phosphoinositides, phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 3-phosphate, are important for the ATP-dependent priming of the secretory apparatus prior to Ca(2+)-dependent exocytosis. Mechanisms that control phosphoinositide levels are likely to play an important role in priming fine tuning. Here we have investigated the involvement of PIKfyve, a phosphoinositide 5-kinase that can phosphorylate phosphatidylinositol 3-phosphate to produce phosphatidylinositol 3,5-bisphosphate on large dense core vesicle exocytosis from neuroendocrine cells. PIKfyve localizes to a subpopulation of secretory granules in chromaffin and PC12 cells. Nicotine stimulation promoted recruitment of PIKfyve-EGFP onto secretory vesicles in PC12 cells. YM-201636, a selective inhibitor of PIKfyve activity, and PIKfyve knockdown by small interfering RNA potentiated secretory granule exocytosis. Overexpression of PIKfyve or its yeast orthologue Fab1p inhibited regulated secretion in PC12 cells, whereas a catalytically inactive PIKfyve mutant had no effect. These results demonstrate a novel inhibitory role for PIKfyve catalytic activity in regulated secretion and provide further evidence for a fine tuning of exocytosis by 3-phosphorylated phosphoinositides.