scholarly journals Influence of Selected Carbon Nanostructures on the CYP2C9 Enzyme of the P450 Cytochrome

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4149
Author(s):  
Justyna Sekretarska ◽  
Jarosław Szczepaniak ◽  
Malwina Sosnowska ◽  
Marta Grodzik ◽  
Marta Kutwin ◽  
...  

Carbon nanostructures have recently gained significant interest from scientists due to their unique physicochemical properties and low toxicity. They can accumulate in the liver, which is the main expression site of cytochrome P450 (CYP450) enzymes. These enzymes play an important role in the metabolism of exogenous compounds, such as drugs and xenobiotics. Altered activity or expression of CYP450 enzymes may lead to adverse drug effects and toxicity. The objective of this study was to evaluate the influence of three carbon nanostructures on the activity and expression at the mRNA and protein levels of CYP2C9 isoenzyme from the CYP2C subfamily: Diamond nanoparticles, graphite nanoparticles, and graphene oxide platelets. The experiments were conducted using two in vitro models. A microsome model was used to assess the influence of the three-carbon nanostructures on the activity of the CYP2C9 isoenzyme. The CYP2C9 gene expression at the mRNA and protein levels was determined using a hepatoma-derived cell line HepG2. The experiments have shown that all examined nanostructures inhibit the enzymatic activity of the studied isoenzymes. Moreover, a decrease in the expression at the mRNA and protein levels was also observed. This indicates that despite low toxicity, the nanostructures can alter the enzymatic function of CYP450 enzymes, and the molecular pathways involved in their expression.

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Ángel Cores ◽  
Noelia Carmona-Zafra ◽  
Olmo Martín-Cámara ◽  
Juan Domingo Sánchez ◽  
Pablo Duarte ◽  
...  

Curcumin shows a broad spectrum of activities of relevance in the treatment of Alzheimer’s disease (AD); however, it is poorly absorbed and is also chemically and metabolically unstable, leading to a very low oral bioavailability. A small library of hybrid compounds designed as curcumin analogues and incorporating the key structural fragment of piperlongumine, a natural neuroinflammation inhibitor, were synthesized by a two-step route that combines a three-component reaction between primary amines, β-ketoesters and α-haloesters and a base-promoted acylation with cinnamoyl chlorides. These compounds were predicted to have good oral absorption and CNS permeation, had good scavenging properties in the in vitro DPPH experiment and in a cellular assay based on the oxidation of dichlorofluorescin to a fluorescent species. The compounds showed low toxicity in two cellular models, were potent inductors of the Nrf2-ARE phase II antioxidant response, inhibited PHF6 peptide aggregation, closely related to Tau protein aggregation and were active against the LPS-induced inflammatory response. They also afforded neuroprotection against an oxidative insult induced by inhibition of the mitochondrial respiratory chain with the rotenone-oligomycin A combination and against Tau hyperphosphorylation induced by the phosphatase inhibitor okadaic acid. This multitarget pharmacological profile is highly promising in the development of treatments for AD and provides a good hit structure for future optimization efforts.


2008 ◽  
Vol 52 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Nicolas Venisse ◽  
Nicolas Grégoire ◽  
Manuella Marliat ◽  
William Couet

ABSTRACT Mechanism-based pharmacokinetic-pharmacodynamic (PK-PD) models describing the fungistatic activity of fluconazole and the fungicidal activity of caspofungin were developed using dynamic in vitro models. Antifungal-drug pharmacokinetics was simulated in vitro, assuming a one-compartment model with an elimination half-life of 3 h and using a wide (1 to 10,000) range of initial concentrations. The number of CFUs over time was determined for up to 31 h and used for PK-PD modeling. A model incorporating first-order natural growth and natural death, plus a maximum number of viable Candida cells, was used to characterize Candida growth in the absence of a drug. Fluconazole was considered to inhibit Candida growth and caspofungin to stimulate Candida death according to an E max pharmacodynamic model. The data were analyzed with Nonmem, using a population approach. A good fit of the data was obtained with satisfactory estimates of PK-PD parameters, especially with drug concentrations producing 50% of the maximal effect: 50% inhibitory concentrations for fluconazole growth inhibition and 50% effective concentrations for caspofungin death stimulation. In conclusion, mechanistic PK-PD models were successfully developed to describe, respectively, the fungistatic and fungicidal activities of fluconazole and caspofungin in vitro. These models provide much better information on the drug effects over time than the traditional PK-PD index based on MICs. However, they need to be further characterized.


2005 ◽  
Vol 289 (5) ◽  
pp. H1843-H1850 ◽  
Author(s):  
Ali Razmara ◽  
Diana N. Krause ◽  
Sue P. Duckles

Activation of inflammatory mechanisms contributes to cerebrovascular pathophysiology. Male gender is associated with increased stroke risk, yet little is known about the effects of testosterone in the cerebral circulation. Therefore, we explored the impact of testosterone treatment on cerebrovascular inflammation with both in vivo and in vitro models of inflammation. We hypothesized that testosterone would augment the expression of two vascular markers of cellular inflammation, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Using four groups of male rats [intact, orchiectomized (ORX), and ORX treated with either testosterone (ORXT) or the testosterone metabolite 17β-estradiol (ORXE)], we determined effects of the sex hormones on cerebrovascular inflammation after intraperitoneal LPS injection. Western blot analysis showed that induction of inflammatory markers was increased in cerebral blood vessels from ORXT rats compared with intact or ORX rats. In contrast, in cerebral blood vessels from ORXE rats, there was a significant decrease in endotoxin-induced COX-2 and iNOS protein levels. Confocal microscopy of cerebral blood vessels from ORXT rats showed increased COX-2 and iNOS immunoreactivity in both endothelial and smooth muscle cells after LPS treatment. In vitro incubation with LPS also induced COX-2 in pial vessels isolated from the four animal treatment groups, with the greatest induction observed in ORXT vessels compared with the ORX and ORXE groups. Production of PGE2, a principal COX-2-derived prostaglandin end product, was also greatest in cerebral vessels isolated from ORXT rats. In conclusion, testosterone increases cerebrovascular inflammation; this effect may contribute to stroke differences between men and women.


Author(s):  
Kalina Andrysiak ◽  
Jacek Stępniewski ◽  
Józef Dulak

AbstractDevelopment of new drugs is of high interest for the field of cardiac and cardiovascular diseases, which are a dominant cause of death worldwide. Before being allowed to be used and distributed, every new potentially therapeutic compound must be strictly validated during preclinical and clinical trials. The preclinical studies usually involve the in vitro and in vivo evaluation. Due to the increasing reporting of discrepancy in drug effects in animal and humans and the requirement to reduce the number of animals used in research, improvement of in vitro models based on human cells is indispensable. Primary cardiac cells are difficult to access and maintain in cell culture for extensive experiments; therefore, the human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) became an excellent alternative. This technology enables a production of high number of patient- and disease-specific cardiomyocytes and other cardiac cell types for a large-scale research. The drug effects can be extensively evaluated in the context of electrophysiological responses with a use of well-established tools, such as multielectrode array (MEA), patch clamp, or calcium ion oscillation measurements. Cardiotoxicity, which is a common reason for withdrawing drugs from marketing or rejection at final stages of clinical trials, can be easily verified with a use of hiPSC-CM model providing a prediction of human-specific responses and higher safety of clinical trials involving patient cohort. Abovementioned studies can be performed using two-dimensional cell culture providing a high-throughput and relatively lower costs. On the other hand, more complex structures, such as engineered heart tissue, organoids, or spheroids, frequently applied as co-culture systems, represent more physiological conditions and higher maturation rate of hiPSC-derived cells. Furthermore, heart-on-a-chip technology has recently become an increasingly popular tool, as it implements controllable culture conditions, application of various stimulations and continuous parameters read-out. This paper is an overview of possible use of cardiomyocytes and other cardiac cell types derived from hiPSC as in vitro models of heart in drug research area prepared on the basis of latest scientific reports and providing thorough discussion regarding their advantages and limitations.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 927
Author(s):  
Farid Ahmad Siddiqui ◽  
Hanna Parkkola ◽  
Vladimir Vukic ◽  
Christina Oetken-Lindholm ◽  
Alok Jaiswal ◽  
...  

The ATP-competitive inhibitors of Hsp90 have been tested predominantly in kinase addicted cancers; however, they have had limited success. A mechanistic connection between Hsp90 and oncogenic K-Ras is not known. Here, we show that K-Ras selectivity is enabled by the loss of the K-Ras membrane nanocluster modulator galectin-3 downstream of the Hsp90 client HIF-1α. This mechanism suggests a higher drug sensitivity in the context of KRAS mutant, HIF-1α-high and/or Gal3-high cancer cells, such as those found, in particular, in pancreatic adenocarcinoma. The low toxicity of conglobatin further indicates a beneficial on-target toxicity profile for Hsp90/Cdc37 interface inhibitors. We therefore computationally screened >7 M compounds, and identified four novel small molecules with activities of 4 μM–44 μM in vitro. All of the compounds were K-Ras selective, and potently decreased the Hsp90 client protein levels without inducing the heat shock response. Moreover, they all inhibited the 2D proliferation of breast, pancreatic, and lung cancer cell lines. The most active compounds from each scaffold, furthermore, significantly blocked 3D spheroids and the growth of K-Ras-dependent microtumors. We foresee new opportunities for improved Hsp90/Cdc37 interface inhibitors in cancer and other aging-associated diseases.


2020 ◽  
pp. 153537022095959
Author(s):  
Keri Dame ◽  
Alexandre JS Ribeiro

Hepatic and cardiac drug adverse effects are among the leading causes of attrition in drug development programs, in part due to predictive failures of current animal or in vitro models. Hepatocytes and cardiomyocytes differentiated from human induced pluripotent stem cells (iPSCs) hold promise for predicting clinical drug effects, given their human-specific properties and their ability to harbor genetically determined characteristics that underlie inter-individual variations in drug response. Currently, the fetal-like properties and heterogeneity of hepatocytes and cardiomyocytes differentiated from iPSCs make them physiologically different from their counterparts isolated from primary tissues and limit their use for predicting clinical drug effects. To address this hurdle, there have been ongoing advances in differentiation and maturation protocols to improve the quality and use of iPSC-differentiated lineages. Among these are in vitro hepatic and cardiac cellular microsystems that can further enhance the physiology of cultured cells, can be used to better predict drug adverse effects, and investigate drug metabolism, pharmacokinetics, and pharmacodynamics to facilitate successful drug development. In this article, we discuss how cellular microsystems can establish microenvironments for these applications and propose how they could be used for potentially controlling the differentiation of hepatocytes or cardiomyocytes. The physiological relevance of cells is enhanced in cellular microsystems by simulating properties of tissue microenvironments, such as structural dimensionality, media flow, microfluidic control of media composition, and co-cultures with interacting cell types. Recent studies demonstrated that these properties also affect iPSC differentiations and we further elaborate on how they could control differentiation efficiency in microengineered devices. In summary, we describe recent advances in the field of cellular microsystems that can control the differentiation and maturation of hepatocytes and cardiomyocytes for drug evaluation. We also propose how future research with iPSCs within engineered microenvironments could enable their differentiation for scalable evaluations of drug effects. Impact statement Cardiac and hepatic adverse drug effects are among the leading causes of attrition in preclinical and clinical drug development programs as well as marketing withdrawals. The insufficiency of animal testing models has led to considerable interest in the employment of cardiac and hepatic models using human-induced pluripotent stem cells (iPSCs) for drug toxicity testing. However, current batches of iPSC-derived cardiomyocytes and hepatocytes are variable and not matured as adult primary tissues, which limit their prediction of drug effects. This article discusses how the use of microfluidics can create microenvironments to better control differentiation protocols and increase the physiological relevance of iPSC-derived cardiomyocytes and hepatocytes. Development and standardization of technologies will enable evaluation of the potential value of cellular microsystems to improve the in vitro models used in drug development programs. Future steps in this field include controlled connections of organ systems to better recreate clinical metabolism and pharmacokinetics.


Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 670
Author(s):  
Wang ◽  
Zhang ◽  
Wang ◽  
Yang ◽  
Wu ◽  
...  

Trefoil factors (TFFs) are regulatory peptides playing critical roles in mucosal repair and protection against a variety of insults within the gastrointestinal tract. This work aimed to explore the effects of deoxynivalenol (DON) on intestinal TFFs expression using in vivo and in vitro models. In an animal trial, twenty-four 28-d-old barrows (Duroc × Landrace × Large White; initial body weight = 7.6 ± 0.7 kg) were randomly divided into three treatments for 28 days, including a control diet (0.61 mg DON/kg feed), and two levels of DON-contaminated diets containing 1.28 and 2.89 mg DON/kg feed, respectively. Piglets exposed to DON had lower mRNA expression of TFF1, TFF2, TFF3, as well as Claudin-4 in the intestine (P < 0.05). Dietary DON exposure decreased the protein levels of TFF2 and TFF3 in the jejunum as demonstrated by western blot and immunohistochemistry. In intestinal porcine epithelial cells (IPEC-J2), DON depressed the mRNA expression of TFF2, TFF3, and Claudin-4. Overexpression of sterile alpha motif (SAM) pointed domain E26 transformation‐specific (ETS) factor (SPDEF) was found to attenuate DON-induced suppression of TFFs in IPEC-J2 cells. Altogether, our work shows, for the first time, that dietary DON exposure depresses the expression of intestinal TFFs in piglets. Given the fundamental role of TFFs in intestinal mucosal homeostasis, our observations indicate that the DON content in animal feed should be strictly controlled based on the existing regulation for DON.


2006 ◽  
Vol 34 (2) ◽  
pp. 247-250 ◽  
Author(s):  
G.A. Rutter ◽  
A. Varadi ◽  
T. Tsuboi ◽  
L. Parton ◽  
M. Ravier

Defective insulin secretion from pancreatic islet β-cells is a sine qua non of Type II (non-insulin-dependent) diabetes. Digital imaging analysis of the nanomechanics of individual exocytotic events, achieved using total internal reflection fluorescence microscopy, has allowed us to demonstrate that insulin is released via transient or ‘cavicapture’ events whereby the vesicle and plasma membranes fuse transiently and reversibly. Such studies reveal that an increase in the number of abortive fusion events contributes to defective insulin secretion in in vitro models of Type II diabetes. Complementary analyses of genome-wide changes in β-cell gene expression, at both the mRNA and protein levels, are now facilitating the identification of key molecular players whose altered expression may contribute to the secretory defects in the diabetic β-cell.


2014 ◽  
Vol 226 (06) ◽  
Author(s):  
D William ◽  
M Linnebacher ◽  
CF Classen

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