Current Drug Metabolism - Volume 23, Issue 3, 2022

Cytochrome P450s are a widespread and vast superfamily of hemeprotein monooxygenases that metabolize physiologically essential chemicals necessary for most species' survival, ranging from protists to plants to humans. They catalyze the synthesis of steroid hormones, cholesterol, bile acids, and arachidonate metabolites and the degradation of endogenous compounds, such as steroids, fatty acids, and other catabolizing compounds as an energy source and detoxifying xenobiotics, such as drugs, procarcinogens, and carcinogens. The human CYP17A1 is one of the cytochrome P450 genes located at the 10q chromosome. The gene expression occurs in the adrenals and gonads, with minor amounts in the brain, placenta, and heart. This P450c17 cytochrome gene is a critical steroidogenesis regulator which performs two distinct activities: 17 alpha-hydroxylase activity (converting pregnenolone to 17- hydroxypregnenolone and progesterone to 17-hydroxyprogesterone; these precursors are further processed to provide glucocorticoids and sex hormones) and 17, 20-lyase activity (which converts 17-hydroxypregnenolone to DHEA). Dozens of mutations within CYP17A1 are found to cause 17-alpha-hydroxylase and 17, 20-lyase deficiency. This condition affects the function of certain hormone-producing glands, resulting in high blood pressure levels (hypertension), abnormal sexual development, and other deficiency diseases. This review highlights the changes in CYP17A1 associated with gene-gene interaction, drug-gene interaction, chemical-gene interaction, and its biochemical reactions; they have some insights to correlate with the fascinating functional characteristics of this human steroidogenic gene. The findings of our theoretical results will be helpful to further the design of specific inhibitors of CYP17A1.

Background: Loop diuretics help to manage the patients with edema associated with congestive heart failure, liver cirrhosis, and renal disease and hypertension. The patients taking loop diuretics may receive other medications to treat comorbidities leading to drug interactions. Methods: The literature was searched in databases such as Medline/PMC/PubMed, Google Scholar, Cochrane Library, Science Direct, EMBASE, Web of science, Ebsco, Directory of open access journals (DOAJ) and reference lists were used to spot relevant articles using keywords Drug interactions, Pharmacodynamic interactions, Loop diuretics, Bumetanide, Ethacrynic acid, Furosemide, and Torsemide. Results: Loop diuretics are associated with hypokalemia, ototoxicity and other adverse effects. The drugs affected by hypokalemia and having the potential of inducing ototoxicity could interact with loop diuretics pharmacodynamically. Loop diuretics can interact with drugs such as amphotericin B, digoxin, angiotensin-converting enzyme inhibitors (ACE inhibitors), antidiabetic drugs, antifungal agents, dobutamine, gossypoland sotalol due to diuretic associated hypokalemia. In addition, the risk of ototoxicity could be enhanced by the concomitant use of loop diuretics and cisplatin, aminoglycoside antibiotics or phosphodiesterase 5 (PDE 5) inhibitors. Loop diuretics may also interact pharmacodynamically with drugs like cephalosporins, ceritinib, levothyroxine, pixantrone, probenecid, lithium, nonsteroidal anti-inflammatory drugs (NSAIDs), sulfonylureas and herbal drugs. Conclusion: Clinicians, pharmacists and other health care providers should take responsibility for the safe use of medications. In addition, they are required to be aware of the drugs interacting with loop diuretics to prevent adverse drug interactions.

Amyotrophic Lateral Sclerosis (ALS) is a terminal neuro-degenerative disorder that is clinically recognized as a gradual degeneration of the upper and lower motor neurons, with an average duration of 3 to 5 years from initial of symptoms to death. The mechanisms underlying the pathogenesis and progression of the disease are multifactorial. Therefore, to find effective treatments, it is necessary to understand the heterogeneity underlying the progression of ALS. Recent developments in gene therapy have opened a new avenue to treat this condition, especially for the characterized genetic types. Gene therapy methods have been studied in various pre-clinical settings and clinical trials, and they may be a promising path for developing an effective and safe ALS cure. A growing body of evidence demonstrates abnormalities in metabolic energy at the cellular and whole-body level in animal models and people living with ALS. Using and incorporatig high-throughput "omics" methods have radically transformed our thoughts about ALS, strengthened our understanding of the disease's dynamic molecular architecture, differentiated distinct patient subtypes, and created a reasonable basis for identifying biomarkers and novel individualised treatments. Future clinical and laboratory trials would also focus on the diverse relationships between metabolism and ALS to address the issue of whether targeting poor metabolism in ALS is an effective way to change disease progression. In this review, we focus on the detailed pathogenesis of ALS and highlight principal genes, i.e., SOD1, TDP-43, C9orf72, and FUS, as well as targeted ALS therapies. An attempt is made to provide up-to-date clinical outcomes, including various biomarkers that are thought to be important players in early ALS detection.

Background: Urinary tissue inhibitor of metalloproteinase-2 (TIMP2) and insulin-like growth factor binding protein-7 (IGFBP7) predict severe acute kidney injury (AKI) in critical illness. Earlier but subtle elevation of either biomarker from nephrotoxicity may predict drug-induced AKI. Methods: A prospective study involving serial urine collection in patients treated with vancomycin, aminoglycosides, amphotericin, foscarnet, or calcineurin inhibitors was performed. Urinary TIMP2 and IGFBP7, both absolute levels and those normalized with urine creatinine, were examined in days leading to AKI onset by KDIGO criteria in cases or at final day of nephrotoxic therapy in non-AKI controls, who were matched for age, baseline kidney function, and nephrotoxic exposure. Results: Urinary biomarker analyses were performed in 21 AKI patients and 28 non-AKI matched-controls; both groups had comparable baseline kidney function and duration of nephrotoxic drug therapy. Significantly higher absolute, normalized, and composite levels of TIMP2 and IGFBP7 were observed in AKI cases versus controls as early as 2-3 days before AKI onset (all P<0.05); >70% of patients with corresponding levels above 75th percentile developed AKI. Normalized TIMP2 at 2-3 days pre-AKI predicted AKI with the highest average AUROC of 0.81, followed by that of composite [TIMP2]x[IGFBP7] (0.78) after cross-validation. [TIMP2]x[IGFBP7] >0.01 (ng/mL)²/1000 predicted AKI with a sensitivity of 79% and specificity of 60%. Conclusion: Elevated urinary TIMP2 or IGFBP7 predicts drug-induced AKI with a lead-time of 2-3 days; an opportune time for interventions to reduce nephrotoxicity.

Background: The introduction of tacrolimus (TAC) to clinical practice was essential to the establishment of transplantation as a therapy for patients with chronic renal disease. However, the higher interindividual variation of TAC metabolism has been an important limiting factor for its clinical use. Although the relationship between CYP3A5 polymorphisms and TAC pharmacokinetics (PK) is well established, the effects of other genetic variants on TAC metabolism, such as POR**28, still remain uncertain. Objective: The study aimed to evaluate the impact of POR variants on TAC PK in renal transplant patients with different CYP3A5 genotypes (expressers and non-expressers). Methods: A total of 115 patients were included in this study. Genomic DNA was isolated from peripheral blood, and the real-time PCR technique was used to analyze the polymorphism POR rs1057868; C>T. Results: During the initial post-transplant period, variant allele carriers (*1/*28 and *28/*28) showed a lower TAC dose requirement than POR wild homozygotes (*1/*1). Regarding the influence of the different polymorphisms of POR within the CYP3A5 expresser and non-expresser groups, no differences were observed in any of the PK parameters analyzed during 12 months after transplantation. Conclusion: In the studied population, the variant allelic POR*28 was significantly associated with lower TAC dose requirements and higher Co/D ratio in the first-month post-transplant. However, the effects of this polymorphism on the CYP3A5 enzyme activity were not observed.

Background: Little is known about cytochrome P450 3A4 (CYP3A4) DNA methylation and transcription alterations in gastric cancer. Objective: In this paper, we initially aimed to address the effect of diazinon pesticide on DNA methylation and transcription changes of the CYP3A4 gene in a human gastric cell line. In the next step, we studied the methylation differences of CpG sites within the upstream regulatory regions of the CYP3A4 gene among human gastric cancerous and healthy tissues. Methods: For the in vitro assay, the methylation changes of the C/EBP response element and transcript level of the CYP3A4 gene were studied following treatment of the AGS cell line with various concentrations of diazinon pesticide. In the next phase, the methylation percentages of 24 CpG sites within or around the upstream regulatory elements, including near promoter, C/EBP binding site, XREM, and CLEM4, in 11 specimens of human gastric cancer tissue were compared to their adjacent healthy tissues. Results: Treatment with 10 μM Diazinon significantly increased the CYP3A4 gene transcription by approximately 27-fold, which was correlated with the hypermethylation of 3 CpGs in C/EBP binding sites, including -5998, -5731 and -5725 (p<0.001 for all comparisons). Results of bisulfite sequencing revealed that the CpG sites which are located in -1521 (p=0.003), -1569 (p=0.027), -10813 (p=0.003), -10851 (p=0.001) and -10895 (p=0.0) bp from transcription start site, were significantly hypermethylated in cancerous tissues comparing to their healthy cohort. Conclusion: Hypermethylation of CLEM4 and a region near the core promoter may have a significant association with gastric cancer incidence.