Dapagliflozin and Ticagrelor Have Additive Effects on the Attenuation of the Activation of the NLRP3 Inflammasome and the Progression of Diabetic Cardiomyopathy: an AMPK-mTOR Interplay.

PURPOSE: Ticagrelor, a P2Y12 receptor antagonist, and dapagliflozin, a sodium-glucose-cotransporter-2 inhibitor, suppress the activation of the NLRP3 inflammasome. The anti-inflammatory effects of dapagliflozin depend on AMPK activation. Also, ticagrelor can activate AMPK. We assessed whether dapagliflozin and ticagrelor have additive effects in attenuating the progression of diabetic cardiomyopathy in T2DM mice. METHODS: Eight-week-old BTBR and wild-type mice received no drug, dapagliflozin (1.5 mg/kg/day), ticagrelor (100 mg/kg/day), or their combination for 12 weeks. Heart function was evaluated by echocardiography and heart tissue samples were assessed for fibrosis, apoptosis, qRT-PCR, and immunoblotting. RESULTS: Both drugs attenuated the progression of diabetic cardiomyopathy as evident by improvements in left ventricular end-systolic and end-diastolic volumes and left ventricular ejection fraction, which were further improved by the combination. Both drugs attenuated the activation of the NOD-like receptor 3 (NLRP3) inflammasome and fibrosis. The effect of the combination was significantly greater than each drug alone on myocardial tissue necrotic factorα (TNFα) and interleukin-6 (IL-6) levels, suggesting additive effects. The combination had also a greater effect on ASC, collagen-1, and collagen-3 mRNA levels than each drug alone. While both drugs activated adenosine mono-phosphate kinase (AMPK), only dapagliflozin activated mTOR and increased RICTOR levels. Moreover, only dapagliflozin decreased myocardial BNP and Caspase-1 mRNA levels, and the effects of dapagliflozin on NLRP3 and collagen-3 mRNA levels were significantly greater than those of ticagrelor. CONCLUSIONS: Both dapagliflozin and ticagrelor attenuated the progression of diabetic cardiomyopathy, the activation of the NLRP3 inflammasome, and fibrosis in BTBR mice with additive effects of the combination. While both dapagliflozin and ticagrelor activated AMPK, only dapagliflozin activated mTOR complex 2 (mTORC2) in hearts of BTBR mice.

Deriving functional human enteroendocrine cells from pluripotent stem cells.

Enteroendocrine cells (EECs) are a minor cell population in the intestine yet they play a major role in digestion, satiety and nutrient homeostasis. Recently developed human intestinal organoid models include EECs, but their rarity makes it difficult to study their formation and function. Here, we used the EEC-inducing property of the transcription factor NEUROG3 in human pluripotent stem cell-derived human intestinal organoids and colonic organoids to promote EEC development in vitro An 8-h pulse of NEUROG3 expression induced expression of known target transcription factors and after 7 days organoids contained up to 25% EECs in the epithelium. EECs expressed a broad array of human hormones at the mRNA and/or protein level, including motilin, somatostatin, neurotensin, secretin, substance P, serotonin, vasoactive intestinal peptide, oxyntomodulin, GLP-1 and INSL5. EECs secreted several hormones including gastric inhibitory polypeptide (GIP), ghrelin, GLP-1 and oxyntomodulin. Injection of glucose into the lumen of organoids caused an increase in both GIP secretion and K-cell number. Lastly, we observed formation of all known small intestinal EEC subtypes following transplantation and growth of human intestinal organoids in mice.

Combined SGLT2 and DPP4 Inhibition Reduces the Activation of the Nlrp3/ASC Inflammasome and Attenuates the Development of Diabetic Nephropathy in Mice with Type 2 Diabetes.

BACGROUND: Sodium-glucose cotransporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 inhibitors (DPP4I) are used to treat type 2 diabetes (T2DM). DPP4 inhibitors (DPP4) attenuate Nlrp3 inflammasome activation in the kidney. SGLT2 inhibition reduces inflammation and attenuates the progression of diabetic nephropathy (DN). The effects of dapagliflozin (Dapa) on the activation of the Nlrp3 inflammasome and the combined effect of SGLT2 and DPP4 on T2DM-induced inflammasome activation and progression of DN have not been previously studied. We assessed whether Dapa attenuates the inflammasome activation and progression of DN in T2DM mice and whether these effects can be augmented by adding DPP4I saxagliptin (Saxa). METHODS AND RESULTS: Male BTBR ob/ob and wild-type (WT) mice received vehicle, Dapa, or Dapa+Saxa for 8 weeks. Serum BUN in the WT mice was 16.9 ± 0.8 mg/dl. It increased to 55.7 ± 2.8 mg/dl in the BTBR mice. Dapa alone reduced BUN to 31.4 ± 1.2 mg/dl. A greater effect was seen in the Dapa+Saxa combination (24.8 ± 0.8 mg/dl). Serum creatinine was 0.16 ± 0.02 and 1.01 ± 0.04 mg/dl in the WT and BTBR mice, respectively. Dapa and Dapa+Saxa attenuated the increase of creatinine to 0.65 ± 0.02 and 0.40 ± 0.03 mg/dl, respectively. Serum cystatin C was elevated in the BTBR mice (3.9 ± 0.1 vs. 0.6 ± 0.2 ng/ml) as compared to WT mice. Dapa (2.4 ± 0.1) and Dapa+Saxa (1.4 ± 0.1) attenuated this increase. Kidney weight was higher in the BTBR than that of WT mice. Dapa reduced the kidney/body weight ratio in the BTBR mice. Dapa+Saxa tended to have greater effect, but the difference was not significant. mRNA levels of NALP3, ASC, IL-1ß, IL-6, caspase-1, TNF-α, collagen-1, and collagen-3 significantly increased in the kidneys of the BTBR compared to the WT mice. Dapa alone and to a greater extent, Dapa+Saxa, attenuated the activation of the inflammasome. Yet, the combination did not result in greater attenuation of the collagen-1 and collagen-3 mRNA levels. The P-AMPK/total AMPK ratio was lower in the BTBR mice than in the WT mice. Dapa and Dapa+ Saxa equally increased the ratio. CONCLUSIONS: Dapa attenuates T2DM-induced activation of the inflammasome and progression of DN in BTBR ob/ob mice. Adding Saxa to Dapa augmented attenuation of the inflammasome, but had no significant effect on kidney weight or collagen-1 and collagen-3 mRNA levels. Future clinical trials are necessary to study the effect of combined SGLT2 inhibitor and incretin therapy on renal outcomes in patients with T2DM.

Optimization of Hydroxyethylamine Transition State Isosteres as Aspartic Protease Inhibitors by Exploiting Conformational Preferences.

NMR conformational analysis of a hydroxyethylamine peptide isostere developed as an aspartic protease inhibitor shows that it is a flexible architecture. Cyclization to form pyrrolidines, piperidines, or morpholines results in a preorganization of the whole system in solution. The resulting conformation is similar to the conformation of the inhibitor in the active site of BACE-1. This entropic gain results in increased affinity for the enzyme when compared with the acyclic system. For morpholines 27 and 29, the combination of steric and electronic factors is exploited to orient substituents toward S1, S1', and S2' pockets both in the solution and in the bound states. These highly preorganized molecules proved to be the most potent compounds of the series. Additionally, the morpholines, unlike the pyrrolidine and piperidine analogues, have been found to be brain penetrant BACE-1 inhibitors.

SGLT-2 Inhibition with Dapagliflozin Reduces the Activation of the Nlrp3/ASC Inflammasome and Attenuates the Development of Diabetic Cardiomyopathy in Mice with Type 2 Diabetes. Further Augmentation of the Effects with Saxagliptin, a DPP4 Inhibitor.

PURPOSE: We assessed whether (1) dapagliflozin (Dapa, an SGLT2-inhibitor) attenuates the deterioration of heart function Nlrp3 and inflammasome activation in diabetic mice. (2) The effects can be augmented with saxagliptin (Saxa), a DDP4-inhibitor. (3) Dapa effect is possibly SGLT2-independent on cardiofibroblasts in vitro. METHODS: Type 2 diabetic (BTBR ob/ob) and wild-type (WT) mice received vehicle, Dapa, or Dapa+Saxa for 8 weeks. Glucose tolerance test and echocardiogram were performed. Cardiofibroblasts from WT and BTBR hearts were incubated with Dapa and exposed to LPS. RESULTS: Left ventricular ejection fraction (LVEF) was 81 ± 1% in the WT and 53 ± 1% in the T2D-cont mice. Dapa and Dapa+Saxa improved LVEF to 68 ± 1 and 74.6 ± 1% in the BTBR mice (p < 0.001). The mRNA levels of NALP3, ASC, IL-1ß, IL-6, caspase-1, and TNFα were significantly higher in the BTBR compared to the WT hearts; and Dapa and Dapa+Saxa significantly attenuated these levels. Likewise, protein levels of NLRP3, TNFα, and caspase-1 were higher in the BTBR compared to the WT hearts and Dapa, and to a greater extent Dapa+Saxa, attenuated the increase in the BTBR mice. Collagen-1 and collagen-3 mRNA levels significantly increased in the BTBR mice and these increases were attenuated by Dapa and Dapa+Saxa. P-AMPK/total-AMPK ratio was significantly lower in the BTBR mice than in the WT mice. Dapa and Dapa+Saxa equally increased the ratio in the BTBR mice. This in vitro study showed that NALP3, ASC, IL-1ß, and caspase-1 mRNA levels were higher in the BTBR cardiofibroblasts and attenuated with Dapa. The effect was AMPK-dependent and SGLT1-independent. CONCLUSIONS: Dapa attenuated the activation of the inflammasome, fibrosis, and deterioration of LVEF in BTBR mice. The anti-inflammatory, anti-fibrotic effects are likely SGLT2- and glucose-lowering-independent, as they were replicated in the in vitro model. The effects on remodeling were augmented when Saxa was added to Dapa. Yet, adding Saxa to Dapa did not result in a greater effect on myocardial fibrosis and collagen levels.