bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quercetin protects against the Aβ‐induced amnesic injury through inhibiting RAGE‐mediated pathway and preserving the neurovascular unit
Authors: Liu Rui , Zhou Dan , Bai Xiaoyu , Du Guanhua 
Published: November 2023

Quercetin is one of the most common flavonoids existing widely in many edible plants. It has demonstrated protective effects against Aβ‐induced toxicity on both neurons and endothelial cells. However, whether or not quercetin has an effect on the neurovascular coupling is unclear. In the present study, we aim to investigate the anti‐amnesic effects of quercetin and to explore the underlying mechanisms. The aggregated Aβ25–35 was injected into the right lateral ventricle in mice. Quercetin was administrated orally for 8 days after injection. Learning and memory behaviors were evaluated by measuring spontaneous alternation in Morris Water Maze test and the step‐through positive avoidance test. The regional cerebral blood flow was monitored before the Aβ25–35 injection and on seven consecutive days after injection. Mice were sacrificed and cerebral cortices were isolated on the last day. The effects of quercetin on the neurovascular unit (NVU) integrity, microvascular function and cholinergic neuronal changes, and the modification of signaling pathways were tested. Our results demonstrate that quercetin treatment for Aβ25–35‐induced amnesic mice improved the learning and memory capabilities and conferred robust neurovascular coupling protection. In these effects, quercetin improved the spatial learning and memory effectively across the acquisition training period and the memory capability trials in behavioral tests. Furthermore, quercetin maintained the integrity of NVU major components, reduced the level of neurovascular oxidation, modulated the rCBF value of cerebral microvessels, improved the function of cholinergic system, and regulated the neurovascular RAGE signaling and ERK/CREB/BDNF pathways. In conclusion, in Aβ25–35‐induced amnesic mice, optimal doses of quercetin administration were beneficial. Quercetin protected the NVU through reduction of oxidative damage, inactivation of RAGE‐mediated pathway and preservation of cholinergic neurons, offering an alternative medication for Alzheimer's disease.Support or Funding InformationThis work was supported by National Natural Science Foundation of China (No. 81102830, 81073120), Beijing New‐star Plan of Science and Technology (xx2013065), and Beijing Organization Department Excellent Talents Project (2013D009008000007).
Identification of a new sesquiterpine component from Schisandra chinensis and its anti‐inflammatory effect
Authors: Park Soojin , Im Dongsoon 
Published: November 2023

BackgroundIn Oriental countries, extracts of Schisandra chinensis have been used as an anti‐fatigue and tonic agent. Because inflammatory and oxidative stress are related to chronic fatigue syndrome, it was hypothesized that Schisandra chinensis has anti‐inflammatory constituents. The effects of new compounds isolated from dry fruits of Schisandra chinensis were studied, to elucidate the anti‐fatigue effect of Schisandra chinesis.METHODSFrom an extract of Schisandra chinensis fruits, SC‐3162 was isolated. Inductions of inducible nitric oxide synthase and cyclooxygenase 2 by lipopolysaccharide were quantified by Western blotting in peritoneal macrophages isolated from thioglycol‐treated mice. A peritonitis animal model was used to test the in vivo efficacy of SC‐3162.RESULTSSC‐3162 inhibited the inductions of inducible nitric oxide synthase and cyclooxygenase 2 in peritoneal macrophages isolated from thioglycol‐treated mice at the mRNA and protein levels. lipopolysaccharide ‐induced productions of nitric oxide and prostaglandin E2 were inhibited by SC‐3162. Furthermore, SC‐3162 inhibited the lipopolysaccharide‐induced activations of p38 MAPK, but not that of ERK and JNK in mouse peritoneal macrophages. In addition, SC‐3162 strongly inhibited the accumulation of neutrophils, eosinophils, and basophils in the peritoneal cavity in the lipopolysaccharide‐induced peritonitis model,.CONCLUSIONSC‐3162 suppresses inflammatory responses in peritoneal macrophages and could be a potential therapeutic agent for treatment of inflammatory diseases.
Mechanistic Investigation into Signaling Specificity of Akt/mTOR Signaling
Authors: Zhou Xin , Zhang Jin 
Published: November 2023

The Akt/mTOR signaling pathway regulates critical cellular processes including cell growth, metabolism, and survival. To achieve the signaling specificity for diverse cellular functions, spatial compartmentalization has been suggested to be an important mechanism. However, the spatial regulation of Akt/mTOR is not well defined and the underlying mechanisms remain poorly understood. We characterize the subcellular Akt/mTOR activity using the newly developed genetically encoded biosensors and further examine the underlying molecular mechanisms of the subcellular Akt/mTOR regulation. We also examine the isoform‐specific regulation of Akt using Akt1 and Akt2 activation reporters. We found conformational changes occur during the activation of Akt isoforms, which are dependent on the presence of the phosphorylatable threonine 308/309 in the activation loop. Mutants of Akt1 and Akt2 carrying phosphomimetic mutations at this residue behave differently in terms of membrane translocation. Take together, our data unveil the location‐specific Akt/mTOR signaling and suggest a model for isoform‐specific activation of Akt.Support or Funding InformationNIH grants R01 DK073368 and DP1 CA174423
The Role of VE‐PTP in Stabilizing VE‐cadherin Adhesion
Authors: Juettner Vanessa V , Dan Arkaprava , Leckband Deborah , Komarova Yulia , Malik Asrar 
Published: November 2023

Vascular Endothelial (VE)‐cadherin is the main adhesion molecule of adherens junctions (AJs) that regulate permeability of the endothelial barrier. It is crucial for maintaining tissue‐fluid homeostasis by restricting the transport of plasma proteins across the endothelium. VE‐cadherin bridges endothelial cells by forming trans interactions with opposing VE‐cadherin molecules at the AJs. VE‐cadherin steady‐state kinetics is described by the rate of VE‐cadherin exchange between junctional and cytosolic pools. In our studies, we determine the role of vascular endothelial protein tyrosine phosphatase (VE‐PTP) in regulating steady‐state kinetics of VE‐cadherin at AJs. Interestingly, overexpression of wild‐type and phosphatase dead VE‐PTP mutant decreased the rate of VE‐cadherin dissociation from AJs suggesting that VE‐PTP controls stability of VE‐cadherin adhesion in a phosphatase‐independent manner. VE‐PTP overexpression also led to activation of Rac1 at AJs thus relieving tension across VE‐cadherin adhesion. To complement these experiments, we measured distribution of intracellular forces at AJs of murine endothelial cells isolated form VE‐PTP knockout model using a biophysical approach. Consistent with the proposed role of VE‐PTP in regulating retraction forces, loss of VE‐PTP led to increased stress at AJs. These findings demonstrate that VE‐PTP stabilizes VE‐cadherin adhesion by regulating the intracellular tension at AJs independent of its phosphatase activity. Future studies will investigate the molecular and signaling mechanisms of VE‐PTP‐dependent regulation of VE‐cadherin dynamics at AJs.Support or Funding InformationFunding: National Institutes of Health grant R01 HL103922 to Y.A. Komarova, and T32 and RO1 HL45638 to A.B. Malik.
A Novel Parenteral Formulation For the Antiplatelet Agent Clopidogrel
Authors: Karim Zubair A , Venkatesan Natarajan , Ting Harold J , Betageri Guru , Khasawneh Fadi T 
Published: November 2023

While platelets play a vital role in preventing excessive bleeding after injury (hemostasis), they also contribute to the genesis of thrombotic disorders. On this basis, research efforts have focused on identifying new targets and/or designing agents against these targets for therapeutic purposes. The P2Y12 receptor (P2Y12R) remains one of the most attractive antiplatelet targets given that it plays a central role in platelet function. Furthermore, clopidogrel (Plavix®), which is a P2Y12R antagonist, is one of the most commonly prescribed drugs. However, one of the limitations facing antiplatelet therapeutic strategies is the lack of safe and/or suitable parenteral antiplatelet agents or formulations in order to complement oral agents. Based on these considerations, we designed and characterized the biological activity of a liposomal formulation (i.e., soya phosphatidylcholine, 50 mg; and cholesterol, 5 mg) of clopidogrel bisulfate under ex vivo and in vivo experimental settings. The liposomal clopidogrel was then administered by intravenous route (IV) to C57BL/6 mice through their tail vein, and our results revealed that one (1) hour post injection this formulation relative to vehicle control: 1. has the capacity to dose dependently (2 or 6 mg/kg) inhibit platelet aggregation induced by the agonist ADP; 2. this inhibitory effect was found to be selective given that it produced no detectable effects on aggregation mediated by a non‐ADP dependent pathway (i.e., the thromboxane receptor pathway stimulated by the agonist U46619); 3. prolong the tail bleeding time (modulate hemostasis), again in a dose‐dependent manner; and 4. confer protection (at 6 mg/kg) against the development of occlusive events using a carotid artery FeCl3 injury‐induced thrombosis model. Collectively, we have successfully prepared and characterized a novel IV formulation for clopidogrel; which exhibits pharmacological activity on mouse platelets, at least 1 hour post administration, and under in vivo conditions. This formulation is expected to have a wide‐therapeutic application, given the limitations of the only currently available IV antiplatelet therapeutic agents (i.e., the platelet glycoprotein IIb IIIa antagonists).Support or Funding InformationCollege of Pharmacy (to F.T.K), Western University of Health Sciences, Pomona, CA 91766
Studies on Pharmacokinetics/Pharmacodanymics of Enrofloxacin in Broiler chicken
Authors: Park Haechul , Kang JeongWoo , Jang Yangho , Song Jae‐Young , Lee Kwang‐Jick 
Published: November 2023

Enrofloxacin(ENR) is a synthetic and second generated fluoroquinolone antibiotics, and has been showed broad spectrum antimicrobial activity. The mechanism of action of ENR is known that inactivation of DNA gyrase by interfering DNA synthesis. It is widely used in veterinary medicine in cattle, dogs, poultry, fish, and cats to treat diseases caused by various bacteria. It is reported that ENR sales amount is the highest among all of antibiotics used in chicken in Korea several years.In this study, pharmacokinetic(PK) and pharmadynamic (PD) of ENR administered with PO and IV were carried out to understand pharmacology of ENR in chicken. To analyze PK parameters, sensitive detection method for ENR was developed and validated by liquid chromatography tandem mass spectrometry, and its metabolite ciprofloxacin in broiler chicken plasma, which was further analyzed to study the pharmacokinetics in broiler chicken. Animal study was carried out in chicken and ENR was administered with PO and IV routes with 10 mg/kg. Serum samples were taken for 20 times. The serum samples were treated for chromatography analysis. The LC‐MS/MS analysis was carried out mobile phase gradient consisting 0.1 % formic acid in D.W. (A) and 0.1 % formic acid in ACN (B) with C18 reverse phase column. Mass spectrometry was performed using the positive ion mode and the selected ion monitoring (MRM). The methods validation results showed that good linearity (R2>0.999) and the quantified average recovery of ENR was 99% at level of 10 ng g−1 ~100 ng g−1. The percent of coefficient of variation (CV) for the described method was less than 5.1 % over the range of concentrations. The limits of detection (LOD) and quantification (LOQ) were 5 and 15 ng g−1, respectively. Several PK parameters of ENR those are area under the curve (AUC), half‐life (T1/2), peak plasma concentration (C max) and so on were obtained from LC‐MS/MS analysis.PD analysis was carried using in vitro (MIC) and ex vivo (time‐kill assay). On MIC studies, ENR(0.004~32 ug/ml) was incubated sensitive bacteria and the MIC concentration was determined by visible turbidity in incubation tubes. The ex vivo study was carried using serum samples which containing ENR from chicken. Integrated PK/PD analysis was carried out based on each PK and PD data. Based on PK/PD analysis, the resistance of ENR on chicken is very high on target bacteria such Campylobacter jejuni, we suggest that newly establishment of administration of ENR in broiler chicken.Support or Funding InformationThis research was supported by a fund(B‐1543073‐2015‐17‐01) by Research of Animal and Plant Quarantine Agency, South Korea
Evaluating Pharmacokinetic Drug‐Drug Interactions Due to Time Dependent Inhibition
Authors: Yadav Jaydeep D , Pham Chuong , Korzekwa Kenneth , Nagar Swati 
Published: November 2023

Time dependent inhibition (TDI) represents a more severe form of inhibition for cytochrome P450 (CYP) enzymes relative to reversible inhibition because inactivated enzymes have to be regenerated to restore their function by de novo synthesis. Moreover, it has been observed that many in vitro TDI exhibiting drugs do not exhibit significant TDI in vivo. The overall goal of this project is to improve TDI predictions with in vitro data. To this end, in vivo TDI data were generated in rats for future in vitro‐in vivo correlation analysis.Drugs exhibiting TDI in vitro (podophyllotoxin (PPT), verapamil, paroxetine) and probe substrate for specific rat cyps (midazolam for cyp3a and desipramine for cyp2d1) were selected for pharmacokinetic (PK) studies. PK studies were conducted in singular jugular cannulated Sprague Dawley (SD) rats with selected CYP substrates. Rats were divided in two groups, control and inactivator treated group. Treated group was initially administered the inactivator and subsequently administered the probe substrate. Blood samples were withdrawn and analyzed for substrate concentration by LC‐MS/MS. Area under the curve (AUC(0‐∞)) ratios were compared between the two groups. Equilibrium dialysis was conducted to find the fraction unbound in plasma (fu) of substrate and the inactivator in five different matrices. PK studies were additionally conducted in SD rats for inactivator alone.The AUC(0‐∞) ratios of two groups were calculated by both non‐compartmental analysis and compartmental analysis. The midazolam AUC ratio for PPT treated vs control groups was found to be 1.18 ± 0.24. The midazolam AUC ratio for verapamil treated vs control groups was 1.26 ± 0.43. The fu for midazolam was 0.04, 0.016, 0.78, 0.43, 0.76 in rat plasma, human plasma, human liver microsome (HLM), rat liver microsome (RLM) and rat hepatocytes respectively.The AUC ratios indicate that the inactivators might not have a significant effect in vivo in rats. However an AUC ratio higher than 1 indicates some enzyme inactivation. In vitro studies are currently underway to conduct in vitro‐in vivo correlation of TDI.Support or Funding InformationThis work was supported by NIH grant GM1R01GM114369 to Ken Korzekwa and Swati Nagar.
Drug Interaction of Pirfenidone with Commonly Prescribed Pharmaceutical Drugs
Authors: Kale Vijay , Manoi Tharit , Porter Caleb , Atkinson Sabrina 
Published: November 2023

PurposePirfenidone was initially developed as an antihelminthic, antipyretic agent now approved by US FDA as antifibrotic drug for the treatment of idiopathic pulmonary fibrosis. In vitro experiments with cell fractions from human liver and recombinant cytochrome P450 enzymes indicate that pirfenidone is primarily metabolized by CYP1A2, although multiple other CYP isoforms contribute to metabolism. Numbers of clinical drugs are substrates to these isoforms and thus it will have significant effects on pirfenidone metabolism. Thus in the present study, we sought to investigate effects of ethynyl estradiol, zileuton, itraconazole, diazepam, omeprazole and naproxen on pirfenidone metabolism using human liver microsomes.MethodsWe ordered human liver microsomes from Life Technologies, Grand Island, NY (Pooled human liver chromosome from 50 donors, CYP450 levels 0.286 nmol/mg; CYP1A2 activity Vmax 0.73 nmol/min/mg of protein, Km 78μM). Pirfenidone, ethynyl estradiol, itraconazole, zileuton, diazepam, omeprazole, naproxen, and DMSO were from Sigma Aldrich, St. Louis MO. Ethyl acetate and 100mM phosphate buffer were from VWR, Randor, PA, C18 (5μm × 4.6mm × 150mm) and guard column were from Waters, Milford, MA. Waters HPLC equipped with photodiode array detector was used for separation and quantification. All other reagents were of analytical and HPLC grade. Briefly the microsomes were incubated with or without drugs (DMSO) at 37°C for 1h in phosphate buffer (total reaction volume was 200uL). Reaction was initiated by adding 20mM NADPH and terminated with equal volume of ethyl acetate. The reaction tubes were vortexed for few seconds to mix all contents and then centrifuged at 7,000g for 10 minutes at 4°C. Supernatant was isolated and stored until further processing at −80°C. 20uL of samples were eluted on HPLC using acetonitrile:water (65:35) as mobile phase at the rate of 0.7 mL/min. Detection wavelength was 317nm. Standard curve was run with same condition using denatured human liver microsomes.ResultsOur microsomal incubation studies show that pirfenidone concentration was significantly increased (126%) when used together with omeprazole as compared to pirfenidone alone. No significant increase in pirfenidone concentration was noted with other drugs (estradiol, itraconazole, zileuton, or naproxen) when used together with pirfenidone.ConclusionOur study suggests that there is a potential drug interaction of pirfenidone with omeprazole when used simultaneously.Support or Funding InformationRoseman University of Health Sciences
Mechanism‐based Inhibition of CYP3A4 by Podophyllotoxin: Integrating Biophysical Measurements into Predictive Analysis
Authors: Barnaba Carlo , Nagar Swati , Korzekwa Ken R , Jones Jeffrey P 
Published: November 2023

Avoiding drug‐drug interactions (DDIs) is a critical effort during drug discovery and development. One of the most difficult DDIs to predict with preclinical data is the time‐dependent inhibition (TDI) of the cytochrome P450 enzymes. Since TDIs result in a loss of enzyme over time, the in vivo impact of TDI is more difficult to assess than competitive inhibitors. Current methods to determine TDI parameters have provided limited success in predicting clinical outcomes. A probably more significant complexity in TDI kinetics is the mechanism of metabolic intermediate complex (MIC) formation. Podophyllotoxin is a methylenedioxyphenyl (MDP) compounds known to cause time‐dependent inhibition of CYP3A4, through a carbene intermediate that can form a pseudo‐irreversible complex with the heme of P450. The goal of the present study is to characterize the time‐course of MIC formation using biophysical techniques and relate these rate constants to observed time‐dependent inactivation kinetics. Here we report novel evidence for the existence of a reversible intermediate that plays a key role in the kinetics of MIC formation. This finding is then used with in vitro TDI kinetics, to greatly increase the accuracy of in vivo DDI predictions relative to existing methodologies.Support or Funding InformationNIH
INTRINSIC INCREASED ACE2 EXPRESSION PROTECTS SPINY MOUSE ACOMYS CAHIRINUS AGAINST ISCHEMIC‐INDUCED CARDIAC DYSFUNCTION
Authors: Qi Yanfei , Zhang Juan , Wang Lei , Kumar Ashok , Vohra Ravneet , Walter Glenn A , Maden Malcolm , Katovich Michael J , Raizada Mohan , Pepine Carl J 
Published: November 2023

Angiotensin converting enzyme 2 (ACE2), a key component of the renin angiotensin system (RAS), is a potential therapeutic target for ischemic heart disease as it protects cardiovascular function. Recently, extensive evidence points to a significant role of ACE2 in regulation of hematopoiesis and vasculogenesis via correction of endothelial progenitor cell dysfunction and increases in the number of cardiac and endothelial progenitor cells after ischemic injury. Spiny mice (Acomys cahirinus, SM) possess lizard‐like abilities when a large portion of skin is “torn away” the deep tissue injury heals rapidly by regenerating complete hair follicles, dermis, epidermis, sebaceous glands, adipose tissue, microvessels, smooth muscle and skeletal muscle of the panniculus carnosus without scaring (Nature 2013). This skin auto to my provides an effective defense against predators. We tested the cardiac regenerative capacity of SM using a myocardial infarction (MI) model. Following ligation of left anterior descending coronary artery, the SM exhibited smaller infarct size (SM‐MI 20% of left ventricular free wall vs CD1‐MI 50%, p<0.05) with preserved ejection fraction vs CD1 mice (SM‐MI 62 ± 2% vs CD1‐MI 32± 7%, p<0.05). At baseline ACE2 activity in SM sham was elevated 12% in myocardial tissue and 23% in plasma vs CDl sham (both, p<0.05). MI resulted in a 37% decrease in ACE2 activity in CD1 mice (p<0.05 vs baseline and vs SM‐MI). Interestingly, SM exhibited further elevation of ACE2 activity (7%) in myocardial tissue following MI, while plasma ACE2 activity remained unchanged after MI. Collectively, our findings suggest that ACE2 is likely to be modulating, at least in part, the myocardial preservation/regeneration process in the SM.Support or Funding Information2 UM1 HL087366‐06, R01 HL056921, HL033610, and UL1 TR000064 from the National Institutes of Health