Membrane transporters interact not only with endogenous substrates but are also engaged in the transport of xenobiotics, including drugs. While the coordinated function of uptake (solute carrier family—SLC and SLCO) and efflux (ATP-binding cassette family—ABC, multidrug and toxic compound extrusion family—MATE) transporter system allows vectorial drug transport, efflux carriers alone achieve barrier functions. The modulation of transport functions was proved to be effective in the treatment strategies of various pathological states. Sodium–glucose cotransporter-2 (SGLT2) inhibitors are the drugs most widely applied in clinical practice, especially in the treatment of diabetes mellitus and heart failure. Sodium taurocholate co-transporting polypeptide (NTCP) serves as virus particles (HBV/HDV) carrier, and inhibition of its function is applied in the treatment of hepatitis B and hepatitis D by myrcludex B. Inherited cholestatic diseases, such as Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC) can be treated by odevixibat and maralixibat, which inhibit activity of apical sodium-dependent bile salt transporter (ASBT). Probenecid can be considered to increase uric acid excretion in the urine mainly via the inhibition of urate transporter 1 (URAT1), and due to pharmacokinetic interactions involving organic anion transporters 1 and 3 (OAT1 and OAT3), it modifies renal excretion of penicillins or ciprofloxacin as well as nephrotoxicity of cidofovir. This review discusses clinically approved drugs that affect membrane/drug transporter function.

Given the substantial correlation between early diagnosis and prolonged patient survival in HCV patients, it is vital to identify a reliable and accessible biomarker. The purpose of this research was to identify accurate miRNA biomarkers to aid in the early diagnosis of HCV and to identify key target genes for anti-hepatic fibrosis therapeutics. The expression of 188 miRNAs in 42 HCV liver patients with different functional states and 23 normal livers were determined using RT-qPCR. After screening out differentially expressed miRNA (DEmiRNAs), the target genes were predicted. To validate target genes, an HCV microarray dataset was subjected to five machine learning algorithms (Random Forest, Adaboost, Bagging, Boosting, XGBoost) and then, based on the best model, importance features were selected. After identification of hub target genes, to evaluate the potency of compounds that might hit key hub target genes, molecular docking was performed. According to our data, eight DEmiRNAs are associated with early stage and eight DEmiRNAs are linked to a deterioration in liver function and an increase in HCV severity. In the validation phase of target genes, model evaluation revealed that XGBoost (AUC = 0.978) outperformed the other machine learning algorithms. The results of the maximal clique centrality algorithm determined that CDK1 is a hub target gene, which can be hinted at by hsa-miR-335, hsa-miR-140, hsa-miR-152, and hsa-miR-195. Because viral proteins boost CDK1 activation for cell mitosis, pharmacological inhibition may have anti-HCV therapeutic promise. The strong affinity binding of paeoniflorin (−6.32 kcal/mol) and diosmin (−6.01 kcal/mol) with CDK1 was demonstrated by molecular docking, which may result in attractive anti-HCV compounds. The findings of this study may provide significant evidence, in the context of the miRNA biomarkers, for early-stage HCV diagnosis. In addition, recognized hub target genes and small molecules with high binding affinity may constitute a novel set of therapeutic targets for HCV.

Parkinson’s disease (PD) is a common neurodegenerative disease characterized by motor and non-motor symptoms including cognitive impairment and dementia. The etiopathogenesis of PD, as well as its protective and susceptibility factors, are still elusive. 3-Hydroxy-3-methyglutaryl coenzyme A reductase (HMGCR) is an enzyme regulating cholesterol synthesis. Single-nucleotide polymorphisms (SNPs) in the gene coding HMGCR have recently been correlated with the risk of Alzheimer’s disease. Alternative splicing of exon 13 of the HMGCR transcript and its strongly associated HMGCR haplotype 7 (H7: rs17244841, rs3846662, rs17238540) may downregulate protein activity and cholesterol synthesis, with lower low-density lipoprotein cholesterol (LDL) levels associated with PD that may affect cognitive abilities. We genotyped three SNPs in the H7 HMGCR gene in 306 PD patients divided into three groups—without cognitive decline, with mild cognitive impairment (MCI), and with PD dementia—and in 242 healthy participants. A correlation between the rs17238540 genotype and PD susceptibility as well as a minor association between rs3846662 and cognitive status in PD patients was observed; however, the two-sided analysis of these groups did not reveal any significance. We observed a statistically significant elevated high-density lipoprotein cholesterol (HDL) plasma level in the minor allele carriers of rs17238540 and rs17244841 among PD patients. This study should be replicated in a larger population.

Epigenetic dysregulation is increasingly recognized as an important contributor to ovarian carcinogenesis, and may provide novel diagnostic and prognostic biomarkers. This study evaluated DNA methylation and mRNA expression of SEPT9 and AKR1B1 in ovarian cancer and benign ovarian lesions and assessed their clinical significance. Tissue samples were obtained from 27 patients with ovarian cancer and 29 patients with benign ovarian lesions. DNA methylation was analyzed by pyrosequencing and mRNA expression by real-time PCR. Associations with clinicopathological variables, serum CA125 and HE4 concentrations, diagnostic performance, and survival outcomes were evaluated. Receiver operating characteristic (ROC) analysis, multivariable logistic regression, Kaplan–Meier analysis, and Cox regression models were performed. Multiple testing was controlled using the Benjamini–Hochberg false discovery rate procedure. Ovarian cancer tissues demonstrated significantly lower SEPT9 methylation (q = 0.008), higher AKR1B1 methylation (q = 0.0008), and lower AKR1B1 mRNA expression (q = 0.035) compared with benign ovarian lesions. SEPT9 methylation showed the highest diagnostic accuracy (AUC = 0.741). Both SEPT9 methylation (OR = 0.92, p = 0.014) and AKR1B1 methylation (OR = 9.69, p = 0.008) remained independently associated with ovarian cancer after adjustment for age and menopausal status. Low AKR1B1 mRNA expression was associated with shorter progression-free survival (p = 0.0007). These findings indicate that SEPT9 methylation and AKR1B1 dysregulation are associated with ovarian cancer. SEPT9 methylation demonstrated the best discriminative ability among the evaluated biomarkers. Further validation in larger independent cohorts is warranted.

Background/Objectives: DNA methylation is a critical epigenetic mechanism involved in gene expression regulation. This study examines promoter methylation of CYP2E1 in healthy liver, intestinal mucosa, as well as pathological liver samples, alongside in in vitro cell models. Methods: First, in tissue samples from the liver, duodenum, jejunum, and colon of healthy organ donors, CYP2E1 promoter methylation was quantified using the EpiTect Methyl II PCR System, while gene expression was determined by quantitative real-time PCR. Then, in vitro experiments were performed using HepG2 and Caco-2 cell lines. Cells were treated with 5-Aza-2′-deoxycytidine to induce demethylation, with subsequent analysis of CYP2E1 mRNA levels. Subsequently, promoter methylation was assessed via pyrosequencing, while gene expression was quantified using quantitative real-time PCR. Results: The analysis revealed statistically significant differences in the methylation patterns of the CYP2E1 promoter between healthy liver and gastrointestinal tissues. In cell lines, treatment with 5-Aza-2′-deoxycytidine resulted in increased CYP2E1 mRNA levels and demonstrated a strong negative correlation between promoter methylation and gene expression. However, in liver disease samples, differential methylation did not consistently translate into decreased CYP2E1 expression. Conclusions: Although in vitro experiments support a regulatory role of promoter methylation in controlling CYP2E1 expression, the clinical data indicate that additional factors may contribute to gene regulation in liver pathology.

The aim of the study was to evaluate the expression and exploratory diagnostic potential of selected microRNAs (miRNAs) in ovarian cancer tissue compared with benign ovarian lesions. Tissue samples from 24 patients with epithelial ovarian cancer and 22 patients with benign ovarian lesions were analyzed by quantitative real-time polymerase chain reaction. Ten candidate miRNAs were assessed; six met the predefined detection criteria and were retained for analysis. Group differences were tested with non-parametric methods and false discovery rate (FDR) correction. Diagnostic performance was evaluated by receiver operating characteristic (ROC) analysis, and multivariable logistic regression adjusted for age and menopausal status. Survival analyses were exploratory. miR-381-3p was downregulated, whereas miR-582-5p and miR-425-5p were upregulated in ovarian cancer compared with benign ovarian lesions; all three differences remained significant after FDR correction. miR-425-5p showed the highest individual diagnostic accuracy (AUC = 0.854) and remained associated with ovarian cancer after adjustment for age and menopausal status (OR = 7.84; 95% CI = 2.05–29.97; p = 0.003). This association was also retained in Firth penalized logistic regression. An exploratory three-miRNA panel achieved an apparent AUC of 0.858 but did not significantly outperform miR-425-5p alone (DeLong p = 0.596); its optimism-corrected bootstrap AUC was 0.822. No significant associations with survival were identified. miR-425-5p was the strongest candidate biomarker in this exploratory tissue-based study. Independent validation is required before clinical application.