CYP2J2 Modulates Diverse Transcriptional Programs in Adult Human Cardiomyocytes

Role of omega-3 and omega-6 endocannabinoids in cardiopulmonary pharmacology

Endocannabinoids are derived from dietary omega-3 and omega-6 fatty acids and play an important role in regulation of inflammation, development, neurodegenerative diseases, cancer, and cardiovascular diseases. They elicit this effect via interactions with cannabinoid receptors 1 and 2 which are also targeted by plant derived cannabinoid from cannabis. The evidence of the involvement of the endocannabinoid system in cardiopulmonary function comes from studies that show that cannabis consumption leads to cardiovascular effect such as arrythmia and is beneficial in lung cancer patients. Moreover, omega-3 and omega-6 endocannabinoids play several important roles in cardiopulmonary system such as causing airway relaxation, suppressing atherosclerosis and hypertension. These effects are mediated via the cannabinoids receptors that are abundant in the cardiopulmonary system. Overall, this chapter reviews the known role of phytocannabinoids and endocannabinoids in the cardiopulmonary context.

Differentially Expressed Genes and Molecular Susceptibility to Human Age-Related Diseases

Mainstream transcriptome profiling of susceptibility versus resistance to age-related diseases (ARDs) is focused on differentially expressed genes (DEGs) specific to gender, age, and pathogeneses. This approach fits in well with predictive, preventive, personalized, participatory medicine and helps understand how, why, when, and what ARDs one can develop depending on their genetic background. Within this mainstream paradigm, we wanted to find out whether the known ARD-linked DEGs available in PubMed can reveal a molecular marker that will serve the purpose in anyone's any tissue at any time. We sequenced the periaqueductal gray (PAG) transcriptome of tame versus aggressive rats, identified rat-behavior-related DEGs, and compared them with their known homologous animal ARD-linked DEGs. This analysis yielded statistically significant correlations between behavior-related and ARD-susceptibility-related fold changes (log₂ values) in the expression of these DEG homologs. We found principal components, PC1 and PC2, corresponding to the half-sum and the half-difference of these log₂ values, respectively. With the DEGs linked to ARD susceptibility and ARD resistance in humans used as controls, we verified these principal components. This yielded only one statistically significant common molecular marker for ARDs: an excess of Fcγ receptor IIb suppressing immune cell hyperactivation.

Identification of Biomarkers Associated with Heart Failure Caused by Idiopathic Dilated Cardiomyopathy Using WGCNA and Machine Learning Algorithms

Background

The genetic factors and pathogenesis of idiopathic dilated cardiomyopathy-induced heart failure (IDCM-HF) have not been understood thoroughly; there is a lack of specific diagnostic markers and treatment methods for the disease. Hence, we aimed to identify the mechanisms of action at the molecular level and potential molecular markers for this disease.

Methods

Gene expression profiles of IDCM-HF and non-heart failure (NF) specimens were acquired from the database of Gene Expression Omnibus (GEO). We then identified the differentially expressed genes (DEGs) and analyzed their functions and related pathways by using "Metascape". Weighted gene co-expression network analysis (WGCNA) was utilized to search for key module genes. Candidate genes were identified by intersecting the key module genes identified via WGCNA with DEGs and further screened via the support vector machine-recursive feature elimination (SVM-RFE) method and the least absolute shrinkage and selection operator (LASSO) algorithm. At last, the biomarkers were validated and evaluated the diagnostic efficacy by the area under curve (AUC) value and further confirmed the differential expression in the IDCM-HF and NF groups using an external database.

Results

We detected 490 genes exhibiting differential expression between IDCM-HF and NF specimens from the GSE57338 dataset, with most of them being concentrated in the extracellular matrix (ECM) of cells related to biological processes and pathways. After screening, 13 candidate genes were identified. Aquaporin 3 (AQP3) and cytochrome P450 2J2 (CYP2J2) showed high diagnostic efficacy in the GSE57338 and GSE6406 datasets, respectively. In comparison to the NF group, AQP3 was significantly down-regulated in the IDCM-HF group, while CYP2J2 was significantly up-regulated.

Conclusion

As far as we know, this is the first study that combines WGCNA and machine learning algorithms to screen for potential biomarkers of IDCM-HF. Our findings suggest that AQP3 and CYP2J2 could be used as novel diagnostic markers and treatment targets of IDCM-HF.

Effect of inflammation on cytochrome P450-mediated arachidonic acid metabolism and the consequences on cardiac hypertrophy

The incidence of heart failure (HF) is generally preceded by cardiac hypertrophy (CH), which is the enlargement of cardiac myocytes in response to stress. During CH, the metabolism of arachidonic acid (AA), which is present in the cell membrane phospholipids, is modulated. Metabolism of AA gives rise to hydroxyeicosatetraenoic acids (HETEs) and epoxyeicosatrienoic acids (EETs) via cytochrome P450 (CYP) ω-hydroxylases and CYP epoxygenases, respectively. A plethora of studies demonstrated the involvement of CYP-mediated AA metabolites in the pathogenesis of CH. Also, inflammation is known to be a characteristic hallmark of CH. In this review, our aim is to highlight the impact of inflammation on CYP-derived AA metabolites and CH. Inflammation is shown to modulate the expression of various CYP ω-hydroxylases and CYP epoxygenases and their respective metabolites in the heart. In general, HETEs such as 20-HETE and mid-chain HETEs are pro-inflammatory, while EETs are characterized by their anti-inflammatory and cardioprotective properties. Several mechanisms are implicated in inflammation-induced CH, including the modulation of NF-κB and MAPK. This review demonstrated the inflammatory modulation of cardiac CYPs and their metabolites in the context of CH and the anti-inflammatory strategies that can be employed in the treatment of CH and HF.

Cardiomyocyte-specific CYP2J2 and its therapeutic implications

INTRODUCTION

Cytochrome P450s (CYPs) are a superfamily of monooxygenases with diverse biological roles. CYP2J2 is an isozyme highly expressed in the heart where it metabolizes endogenous substrates such as N-3/N-6 polyunsaturated fatty acids (PUFA) to produce lipid mediators involved in homeostasis and cardioprotective responses. Expanding our knowledge of the role CYP2J2 has within the heart is important for understanding its impact on cardiac health and disease.

AREAS COVERED

The objective of this review was to assess the state of knowledge regarding cardiac CYP2J2. A literature search was conducted using PubMed-MEDLINE (from 2022 and earlier) to evaluate relevant studies regarding CYP2J2 mediated cardioprotection, small molecule modulators, effects of CYP2J2 substrates toward biologically relevant effects and implications of CYP2J2 polymorphisms and sexual dimorphism in the heart.

EXPERT OPINION

Cardiac CYP2J2-mediated metabolism of endogenous and exogenous substrates have been shown to impact cardiac function. Identifying individual factors, like sex and age, that affect CYP2J2 require further elucidation to better understand CYP2J2's clinical relevance. Resolving the biological targets and activities of CYP2J2-derived PUFA metabolites will be necessary to safely target CYP2J2 and design novel analogues. Targeting CYP2J2 for therapeutic aims offers a potential novel approach to regulating cardiac homeostasis, drug metabolism and cardioprotection.

Changes in the Left Ventricular Eicosanoid Profile in Human Dilated Cardiomyopathy

Objective

Metabolites derived from N−3 and N−6 polyunsaturated fatty acids (PUFAs) have both beneficial and detrimental effects on the heart. However, contribution of these lipid mediators to dilated cardiomyopathy (DCM)-associated mitochondrial dysfunction remains unknown. This study aimed to characterize DCM-specific alterations in the PUFA metabolome in conjunction with cardiac mitochondrial quality in human explanted heart tissues.

Methods

Left ventricular tissues obtained from non-failing control (NFC) or DCM explanted hearts, were assessed for N−3 and N−6 PUFA metabolite levels using LC-MS/MS. mRNA and protein expression of CYP2J2, CYP2C8 and epoxide hydrolase enzymes involved in N−3 and N−6 PUFA metabolism were quantified. Cardiac mitochondrial quality was assessed by transmission electron microscopy, measurement of respiratory chain complex activities and oxygen consumption (respiratory control ratio, RCR) during ADP-stimulated ATP production.

Results

Formation of cardioprotective CYP-derived lipid mediators, epoxy fatty acids (EpFAs), and their corresponding diols were enhanced in DCM hearts. These findings were corroborated by increased expression of CYP2J2 and CYP2C8 enzymes, as well as microsomal and soluble epoxide hydrolase enzymes, suggesting enhanced metabolic flux and EpFA substrate turnover. DCM hearts demonstrated marked damage to mitochondrial ultrastructure and attenuated mitochondrial function. Incubation of fresh DCM cardiac fibers with the protective EpFA, 19,20-EDP, significantly improved mitochondrial function.

Conclusions

The current study demonstrates that increased expressions of CYP-epoxygenase enzymes and epoxide hydrolases in the DCM heart correspond with enhanced PUFA-derived EpFA turnover. This is accompanied by severe mitochondrial functional impairment which can be rescued by the administration of exogenous EpFAs.

Site-directed deuteration of dronedarone preserves cytochrome P4502J2 activity and mitigates its cardiac adverse effects in canine arrhythmic hearts

Cytochrome P4502J2 (CYP2J2) metabolizes arachidonic acid (AA) to cardioprotective epoxyeicosatrienoic acids (EETs). Dronedarone, an antiarrhythmic drug prescribed for treatment of atrial fibrillation (AF) induces cardiac adverse effects (AEs) with poorly understood mechanisms. We previously demonstrated that dronedarone inactivates CYP2J2 potently and irreversibly, disrupts AA-EET pathway leading to cardiac mitochondrial toxicity rescuable via EET enrichment. In this study, we investigated if mitigation of CYP2J2 inhibition prevents dronedarone-induced cardiac AEs. We first synthesized a deuterated analogue of dronedarone (termed poyendarone) and demonstrated that it neither inactivates CYP2J2, disrupts AA-EETs metabolism nor causes cardiac mitochondrial toxicity in vitro. Our patch-clamp experiments demonstrated that pharmacoelectrophysiology of dronedarone is unaffected by deuteration. Next, we show that dronedarone treatment or CYP2J2 knockdown in spontaneously beating cardiomyocytes indicative of depleted CYP2J2 activity exacerbates beat-to-beat (BTB) variability reflective of proarrhythmic phenotype. In contrast, poyendarone treatment yields significantly lower BTB variability compared to dronedarone in cardiomyocytes indicative of preserved CYP2J2 activity. Importantly, poyendarone and dronedarone display similar antiarrhythmic properties in the canine model of persistent AF, while poyendarone substantially reduces beat-to-beat variability of repolarization duration suggestive of diminished proarrhythmic risk. Our findings prove that deuteration of dronedarone prevents CYP2J2 inactivation and mitigates dronedarone-induced cardiac AEs.

Comprehensive transcriptome-wide analysis of spliceopathy correction of myotonic dystrophy using CRISPR-Cas9 in iPSCs-derived cardiomyocytes

CTG repeat expansion (CTG_exp) is associated with aberrant alternate splicing that contributes to cardiac dysfunction in myotonic dystrophy type 1 (DM1). Excision of this CTG_exp repeat using CRISPR-Cas resulted in the disappearance of punctate ribonuclear foci in cardiomyocyte-like cells derived from DM1-induced pluripotent stem cells (iPSCs). This was associated with correction of the underlying spliceopathy as determined by RNA sequencing and alternate splicing analysis. Certain genes were of particular interest due to their role in cardiac development, maturation, and function (TPM4, CYP2J2, DMD, MBNL3, CACNA1H, ROCK2, ACTB) or their association with splicing (SMN2, GCFC2, MBNL3). Moreover, while comparing isogenic CRISPR-Cas9-corrected versus non-corrected DM1 cardiomyocytes, a prominent difference in the splicing pattern for a number of candidate genes was apparent pertaining to genes that are associated with cardiac function (TNNT, TNNT2, TTN, TPM1, SYNE1, CACNA1A, MTMR1, NEBL, TPM1), cellular signaling (NCOR2, CLIP1, LRRFIP2, CLASP1, CAMK2G), and other DM1-related genes (i.e., NUMA1, MBNL2, LDB3) in addition to the disease-causing DMPK gene itself. Subsequent validation using a selected gene subset, including MBNL1, MBNL2, INSR, ADD3, and CRTC2, further confirmed correction of the spliceopathy following CTG_exp repeat excision. To our knowledge, the present study provides the first comprehensive unbiased transcriptome-wide analysis of the differential splicing landscape in DM1 patient-derived cardiac cells after excision of the CTG_exp repeat using CRISPR-Cas9, showing reversal of the abnormal cardiac spliceopathy in DM1.

Mass spectrometry-based targeted proteomics method for the quantification of clinically relevant drug metabolizing enzymes in human specimens

Biotransformation by phase I and II metabolizing enzymes represents the major determinant for the oral bioavailability of many drugs. To estimate the pharmacokinetics, data on protein abundance of hepatic and extrahepatic tissues, such as the small intestine, are required. Targeted proteomics assays are nowadays state-of-the-art for absolute protein quantification and several methods for quantification of drug metabolizing enzymes have been published. However, some enzymes remain still uncovered by the analytical spectra of those methods. Therefore, we developed and validated a quantification assay for two carboxylesterases (CES-1, CES-2), 17 cytochrome P450 enzymes (CYP) (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP2J2, CYP3A4, CYP3A5, CYP3A7, CYP4F2, CYP4F12, CYP4A11) and five UDP-glucuronosyltransferases (UGTs) (UGT1A1, UGT1A3, UGT2B7, UGT2B15, UGT2B17). Protein quantification was performed by analyzing proteospecific surrogate peptides after tryptic digestion with stable isotope-labelled standards. Chromatographic separation was performed on a Kinetex® 2.6 µm C18 100 Å core-shell column (100 × 2.1 mm) with a gradient elution using 0.1% formic acid and acetonitrile containing 0.1% formic acid with a flow rate of 200 µl/min. Three mass transitions were simultaneously monitored with a scheduled multiple reaction monitoring (sMRM) method for each analyte and standard. The method was partly validated according to current bioanalytical guidelines and met the criteria regarding linearity (0.1-25 nmol/L), within-day and between-day accuracy and precision as well as multiple stability criteria. Finally, the developed method was successfully applied to determine the abundance of the aforementioned enzymes in human intestinal und liver microsomes. Our work offers a new fit for purpose method for the absolute quantification of CES, CYPs and UGTs in various human tissues and can be used for the acquisition of data for physiologically based pharmacokinetic modelling.

The Role of Epoxyeicosatrienoic Acids in Cardiac Remodeling

Epoxyeicosatrienoic acids (EETs) are metabolites of arachidonic acid by cytochrome P450 (CYP) epoxygenases, which include four regioisomers: 5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET. Each of them possesses beneficial effects against inflammation, fibrosis, and apoptosis, which could combat cardiovascular diseases. Numerous studies have demonstrated that elevation of EETs by overexpression of CYP2J2, inhibition of sEH, or treatment with EET analogs showed protective effects in various cardiovascular diseases, including hypertension, myocardial infarction, and heart failure. As is known to all, cardiac remodeling is the major pathogenesis of cardiovascular diseases. This review will begin with the introduction of EETs and their protective effects in cardiovascular diseases. In the following, the roles of EETs in cardiac remodeling, with a particular emphasis on myocardial hypertrophy, apoptosis, fibrosis, inflammation, and angiogenesis, will be summarized. Finally, it is suggested that upregulation of EETs is a potential therapeutic strategy for cardiovascular diseases. The EET-related drug development against cardiac remodeling is also discussed, including the overexpression of CYP2J2, inhibition of sEH, and the analogs of EET.