Safety and effectiveness of empagliflozin and linagliptin fixed-dose combination therapy in Japanese patients with type 2 diabetes: final results of a one-year post-marketing surveillance study.

BACKGROUND: Fixed-dose combination (FDC) of the sodium-glucose co-transporter 2 inhibitor empagliflozin and the dipeptidyl peptidase-4 inhibitor linagliptin was approved for type 2 diabetes (T2D) treatment in Japan in 2018. We conducted a post-marketing surveillance study of empagliflozin/linagliptin FDC in routine clinical practice in Japan. RESEARCH DESIGN AND METHODS: This one-year, prospective, multicenter, observational study investigated the safety and effectiveness of empagliflozin/linagliptin FDC in Japanese patients with T2D. The primary outcome was incidence of adverse drug reactions (ADRs). RESULTS: Among 1146 patients, mean (SD) age was 63.8 (12.8) years and 22.08% were aged ≥75 years. Mean (SD) glycated hemoglobin (HbA1c) was 7.66% (1.21); fasting plasma glucose (FPG) was 142.90 mg/dl (43.75). ADRs were experienced by 32 (2.79%) patients (1 serious ADR); ADRs of important identified risk included urinary tract infection (7 patients [0.61%]), hypoglycemia (2 [0.17%]), ketoacidosis (0), genital infection (1 [0.09%]), and volume depletion (1 [0.09%]). Overall mean (SD) change from baseline in body weight, HbA1c, and FPG were -1.08 kg (3.21), -0.39% (1.11), and -7.90 mg/dl (39.12), respectively. CONCLUSIONS: Empagliflozin/linagliptin FDC was effective and generally well tolerated in Japanese patients with T2D; no new safety concerns were identified. TRIAL REGISTRATION: The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT03761797) [Figure: see text] [Figure: see text].

PE859, A Novel Curcumin Derivative, Inhibits Amyloid-ß and Tau Aggregation, and Ameliorates Cognitive Dysfunction in Senescence-Accelerated Mouse Prone 8.

Aggregation of amyloid-ß (Aß) and tau plays a crucial role in the onset and progression of Alzheimer's disease (AD). Therefore, the inhibition of Aß and tau aggregation may represent a potential therapeutic target for AD. Herein, we designed and synthesized both Aß and tau dual aggregation inhibitors based on the structure of curcumin and developed the novel curcumin derivative PE859. In this study, we investigated the inhibitory activity of PE859 on Aß aggregationin vitro and the therapeutic effects of PE859 on cognitive dysfunction via dual inhibition of Aß and tau aggregation in vivo. PE859 inhibited Aß aggregation in vitro and protected cultured cells from Aß-induced cytotoxicity. Furthermore, PE859 ameliorated cognitive dysfunction and reduced the amount of aggregated Aß and tau in brains of senescence-accelerated mouse prone 8 (SAMP8). These results warrant consideration of PE859 as a candidate drug for AD.

Both C1B domain and pseudosubstrate region are necessary for saturated fatty acid-induced translocation of εPKC to the plasma membrane: distinct role of intramolecular domains for different translocation.

It is well known that protein kinase C (PKC) shows different translocation depending on subtype and stimulation, contributing to the physiological importance of the enzyme. However, molecular mechanism causing the different translocation has been unknown. Therefore, using GFP-tagged mutant εPKC, we attempted to identify the intramolecular domains required for saturated fatty acid-induced translocation of εPKC to the plasma membrane, and compared with those necessary for unsaturated fatty acid-induced translocation to the Golgi complex. We found that, unlike in the case of unsaturated fatty-acid induced translocation, both C1B domain and pseudosubstrate region are necessary for the saturated fatty acid-induced translocation of εPKC to the plasma membrane. The results suggest that different domains of PKC mediate distinct translocation depending on different stimulations, contributing to their subtype- and stimulation-specific functions.

Regulation of GluA1 AMPA receptor through PKC phosphorylation induced by free fatty acid derivative HUHS2002.

The present study investigated the effect of 4-[4-(Z)-hept-1-enyl-phenoxy] butyric acid (HUHS2002), a newly synthesized free fatty acid derivative, on α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor responses. HUHS2002 potentiated currents through GluA1 AMPA receptors expressed in Xenopus oocytes in a bell-shaped concentration (1 nM-1 µM)-dependent manner, the maximum reaching nearly 140 % of original amplitude at 100 nM. The potentiation was significantly inhibited by GF109203X, an inhibitor of protein kinase C (PKC), but not KN-93, an inhibitor of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII). HUHS2002 had no potentiating effect on currents through mutant GluA1 AMPA receptors with replacement of Ser831, a PKC/CaMKII phosphorylation site, by Ala. In the in situ PKC assay using rat PC-12 cells, HUHS2002 significantly enhanced PKC activity, that is suppressed by GF109203X. Overall, the results of the present study show that HUHS2002 potentiates GluA1 AMPA receptor responses by activating PKC and phosphorylating the receptors at Ser831, regardless of CaMKII activation and phosphorylation.

Sphingosine induces apoptosis in MKN-28 human gastric cancer cells in an SDK-dependent manner.

BACKGROUND/AIMS: Evidence has pointed to the role of sphingosine in cellular differentiation, cell growth, and apoptosis. The present study investigated sphingosine-induced apoptosis in human gastric cancer cells. METHODS: Well differentiated MKN-28 and poorly differentiated MKN-45 human gastric cancer cells were cultured. MTT assay, TUNEL staining, Western blotting, and assay of caspase-3, -8, and -9 activities were carried out in cells transfected with and without the siRNA to silence the protein kinase C (PKC)-δ-targeted gene. RESULTS: Sphingosine induced apoptosis in MKN-28 cells, with the potential much greater than for MKN-45 cells. Transfection with the siRNA to silence the PKC-δ-targeted gene (PKC-δ siRNA) into MKN-28 cells significantly reduced presence of sphingosine-dependent protein kinase (SDK) in association with reduced PKC-δ expression. Sphingosine-induced apoptosis in MKN-28 cells was prevented by transfecting with the PKC-δ siRNA. Sphingosine promoted SDK production from PKC-δ and increased phosphorylated 14-3-3 protein for MKN-28 cells, but such effects were not found with MKN-45 cells. Moreover, sphingosine perturbed mitochondrial membrane potentials and activated caspase-3 and caspase-9 in MKN-28 cells, which were also inhibited by transfecting with the PKC-δ siRNA. CONCLUSION: The results of the present study indicate that sphingosine induces apoptosis in well differentiated MKN-28 human gastric cancer cells by increasing SDK production from PKC-δ, to phosphorylate 14-3- 3 protein, thereby causing disruption of mitochondrial membrane potentials and activating caspase-9 followed by the effector caspase-3.

Free fatty acid derivative HUHS2002 potentiates α7 ACh receptor responses through indirect activation of CaMKII.

The present study examined the effect of 4-[4-(Z)-hept-1-enyl-phenoxy] butyric acid (HUHS2002), a free fatty acid derivative, on α7 acetylcholine (ACh) receptor responses. HUHS2002 potentiated whole-cell membrane currents through α7 ACh receptors expressed in Xenopus oocytes in a concentration (1-100 nM)-dependent manner, reaching about 140 % of the original amplitude at 100 nM 50 min after a 10-min treatment. The HUHS2002 effect was prevented by KN-93, an inhibitor of Ca²âº/calmodulin-dependent protein kinase II (CaMKII), while it was not affected by GF109203X, an inhibitor of protein kinase C (PKC), or H-89, an inhibitor of protein kinase A (PKA). In the in situ CaMKII assay using cultured rat hippocampal neurons, HUHS2002 activated CaMKII and the activation was abolished by KN-93. In the cell-free assay of protein phosphatase 1 (PP1), HUHS2002 partially inhibited PP1 activity. Taken together, these results indicate that HUHS2002 potentiates α7 ACh receptor responses by indirectly activating CaMKII, possibly via inhibition of PP1.

Synaptotagmin1 synthesis induced by synaptic plasticity in mouse hippocampus through activation of nicotinic acetylcholine receptors.

We have reported that systemic application of nicotinic agonists expresses a long-term potentiation (LTP)-like facilitation, a model of synaptic plasticity, in vivo in the mouse hippocampus. The present study conducted to clarify the involvement of synaptotagmin1 in synaptic plasticity by investigating the time-dependent change of the mRNA and protein levels of synaptotagmin1 during LTP-like facilitation in the mouse hippocampus. The mRNA expression of synaptotagmin1 increased during 2- to 8-h period by intraperitoneal application of nicotine (3mg/kg), returning to the basal level in 12-h. Also, the protein level of synaptotagmin1, but not synaptophysin, in a total fraction from hippocampus increased during 4- to 12-h period by the same treatment, returning to the basal level in 24-h. The protein level of synaptotagmin1 in a membrane fraction from hippocampus also increased during 4- to 8-h period by nicotine, returning to the basal level in 12-h. This nicotine-enhanced synaptotagmin1 protein in a membrane fraction was inhibited by pretreatment of mecamylamine (0.3mg/kg, i.p.), a nonselective nicotinic acetylcholine receptors (nAChRs) antagonist. Furthermore, choline (30mg/kg, i.p.), a selective α7 nAChR agonist, or ABT-418 (10mg/kg, i.p.), a selective α4ß2 nAChR agonist, enhanced the level of synaptotagmin1 in a membrane fraction. Our findings demonstrate that synaptotagmin1 protein following mRNA which is enhanced without increasing the number of synapse gathers around pre-synaptic membrane during hippocampal LTP-like facilitation through activation of α7 and/or α4ß2 nAChRs in the brain. These results suggest that new-synthesized synaptotagmin1 following synaptic plasticity may contribute to long-lasting synaptic plasticity via positive, feedfoward mechanisms.

AMPA reduces surface expression of NR1 through regulation of GSK3beta.

Emerging evidence has suggested that alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) protects neurons from glutamate-induced neurotoxicity. In this study, we examined the effect of AMPA on the cell surface expression of the N-methyl-D-aspartate (NMDA) receptor, a central player in glutamate-induced neurotoxicity, using rat cortical neurons. AMPA (10 microM, 24 h) attenuated the expression of cell surface NR1, an NMDA receptor subunit, and also inhibited glutamate-induced increases in intracellular Ca2+. SB216763, an inhibitor of glycogen synthase kinase 3beta (GSK3beta), had effects similar to those of AMPA. We have earlier shown that AMPA treatment attenuated GSK3beta activity. Our data suggest that AMPA reduces the cell surface expression of NMDA receptors through the regulation of GSK3beta and, consequently, reduces the amount of intracellular Ca2+.

N-cadherin-based adhesion enhances Abeta release and decreases Abeta42/40 ratio.

In neurons, Presenilin 1(PS1)/gamma-secretase is located at the synapses, bound to N-cadherin. We have previously reported that N-cadherin-mediated cell-cell contact promotes cell-surface expression of PS1/gamma-secretase. We postulated that N-cadherin-mediated trafficking of PS1 might impact synaptic PS1-amyloid precursor protein interactions and Abeta generation. In the present report, we evaluate the effect of N-cadherin-based contacts on Abeta production. We demonstrate that stable expression of N-cadherin in Chinese hamster ovary cells, expressing the Swedish mutant of human amyloid precursor protein leads to enhanced secretion of Abeta in the medium. Moreover, N-cadherin expression decreased Abeta(42/40) ratio. The effect of N-cadherin expression on Abeta production was accompanied by the enhanced accessibility of PS1/gamma-secretase to amyloid precursor protein as well as a conformational change of PS1, as demonstrated by the fluorescence lifetime imaging technique. These results indicate that N-cadherin-mediated synaptic adhesion may modulate Abeta secretion as well as the Abeta(42/40) ratio via PS1/N-cadherin interactions.

alpha-Amino-3-hydroxy-5-methyl-4-isoxazole propionate attenuates glutamate-induced caspase-3 cleavage via regulation of glycogen synthase kinase 3beta.

Preconditioning of sublethal ischemia exhibits neuroprotection against subsequent ischemia-induced neuronal death. It has been indicated that glutamate, an excitatory amino acid, is involved in the pathogenesis of ischemia-induced neuronal death or neurodegeneration. To elucidate whether prestimulation of glutamate receptor could counter ischemia-induced neuronal death or neurodegeneration, we examined the effect of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA), an ionotropic subtype of glutamate receptor, on excess glutamate-induced excitotoxicity using primary cortical neuronal cultures. We found that AMPA exerted a neuroprotective effect in a time- and concentration-dependent manner. A blocker of phosphatidylinositol-3 kinase (PI3K), LY294002 (10 microM), significantly attenuated AMPA-induced protection. In addition, Ser473 of Akt/PKB, a downstream target of PI3K, was phosphorylated by AMPA administration (10 microM). Glycogen synthase kinase 3beta (GSK3beta), which has been reported to be inactivated by Akt, was phosphorylated at Ser9 by AMPA. Ser9-phosphorylated GSK3beta or inactivated form would be a key molecule for neuroprotection, insofar as lithium chloride (100 microM) and SB216763 (10 microM), inhibitors of GSK3beta, also induced phosphorylation of GSK3beta at Ser9 and exerted neuroprotection, respectively. Glutamate (100 microM) increased cleaved caspase-3, an apoptosis-related cysteine protease, and caspase-3 inhibitor (Ac-DEVD-CHO; 1 microM) blocked glutamate-induced excitotoxicity in our culture. AMPA (10 microM, 24 hr) and SB216763 (10 microM) prominently decreased glutamate-induced caspase-3 cleavage. These findings suggest that AMPA activates PI3K-Akt and subsequently inhibits GSK3beta and that inactivated GSK3beta attenuates glutamate-induced caspase-3 cleavage and neurotoxicity.

Characterization of sequential N-cadherin cleavage by ADAM10 and PS1.

N-cadherin is essential for excitatory synaptic contact in the hippocampus. At the sites of synaptic contact, it forms a complex with Presenilin 1(PS1) and beta-catenin. N-cadherin is cleaved by ADAM10 in response to NMDA receptor stimulation, producing a membrane fragment Ncad/CTF1 in neurons. NMDA receptor stimulation also enhances PS1/gamma-secretase-mediated cleavage of N-cadherin. To characterize the regulatory mechanisms of the ADAM10 and PS1-mediated cleavages, we first identified the precise cleavage sites of N-cadherin by ADAM10 and PS1/gamma-secretase by producing cleavage-deficient N-cadherin mutants. Next, we found that ectodomain shedding of N-cadherin by ADAM10 is a primary regulatory step in response to calcium influx, and that it is required for the subsequent PS1/gamma-secretase-mediated epsilon-cleavage of N-cadherin, which is a constitutive process to yield a cytoplasmic fragment, Ncad/CTF2. Since N-cadherin is essential for the structure and function of synapses including the long-term potentiation, those proteolytic events of N-cadherin should affect the adhesive behavior of the synapses, thereby taking part in learning and memory.

Activity-dependent regulation of beta-catenin via epsilon-cleavage of N-cadherin.

N-cadherin is essential for excitatory synaptic contact in the hippocampus. Presenilin 1 (PS1) is located at sites of synaptic contact, forming a complex with N-cadherin and beta-catenin. Here, we report that human N-cadherin is cleaved by PS1/gamma-secretase in response to physiological concentration of glutamate (Glu) stimulation, yielding a fragment Ncad/CTF2. The expression of Ncad/CTF2 in neuronal cells led to its translocation to the nucleus, and caused a prominent enhancement of cytoplasmic and nuclear beta-catenin levels in a cell-cell contact dependent manner, via following mechanisms: 1, inhibition of beta-catenin phosphorylation; 2, transactivation of beta-catenin; and 3, inhibition of N-cadherin transcription, and finally enhanced beta-catenin nuclear signaling. Since the regulation of cellular beta-catenin level is essential for synaptic function, disruption in the cleavage of N-cadherin may be causally linked to the synaptic dysfunction associated with Alzheimer's disease (AD).