Search Results (160)

Background: Progressive familial intrahepatic cholestasis (PFIC) describes a group of genetically heterogeneous disorders. Several mutations in the ATP-Binding Cassette Subfamily B Member 4 (ABCB4) gene have been confirmed to cause reduced phosphatidylcholine levels in bile, leading to a deficiency of biliary vesicles and instability of mixed in micelles. The disease spectrum ranges from PFIC type 3 (PFIC3) to milder conditions. Herein, we present a rare case of PFIC3 in a young woman, emphasizing the importance of early detection and management. Methods: The patient was diagnosed using next-generation sequencing, with genetic testing and analysis performed by the Chengdu Hua Chuang Testing Institute. Variant pathogenicity was evaluated according to the American College of Medical Genetics and Genomics guidelines and classified into five categories: pathogenic, likely pathogenic, uncertain significance, likely benign, and benign. Nomenclature was assigned following the Human Genome Variation Society standards. Results: Contrast-enhanced abdominal computed tomography demonstrated liver cirrhosis with marked splenomegaly. Histological examination of liver biopsy specimens using hematoxylin and eosin and Masson staining further confirmed cirrhotic changes. Genetic testing was subsequently performed and revealed a likely pathogenic variant, c.2757T > A (p. Tyr919Ter), in exon 22 of the ABCB4 gene, which was also detected in the patient’s mother but absent in her father. Finally, PFIC3 was diagnosed. Following initiation of ursodeoxycholic acid therapy, the patient showed moderate improvement in liver function tests, underscoring a clinical case with therapeutic implications. Conclusions: Molecular genetic analyses of ABCB4 are essential for the accurate diagnosis of PFIC3. Clinicians should consider cholestatic liver diseases, particularly PFIC, as a differential diagnosis in cases of liver cirrhosis with unknown etiology, especially in young patients who lack prior symptoms or a family history of liver disease. Full article

The research aimed to study the genome of Cryptococcus neoformans isolated from bird excreta. Thirteen isolates were cultured, colony stained, and underwent biochemical testing confirmation by nested polymerase chain reaction using ITS1-ITS4 and CN4-CN5 primers, respectively. Antifungal susceptibility testing and whole-genomic sequencing were analyzed. The results determined that all isolates were susceptible to amphotericin B (100%), fluconazole, and itraconazole (92.3%). One isolate (DOP3) showed resistance to fluconazole and itraconazole (MIC >64 and >8 µg/mL, respectively). A phylogenetic tree showed the identity of C. neoformans (serotype A). The genome of resistant (DOP3) and non-resistant isolates (DOP3.1) had 14 chromosomes. DOP3 consisted of 38 candidate antifungal resistance genes, which were the most active against azoles (14). The annotated genes in the azole group mostly were in the ATP-binding cassette transporter transmembrane superfamily. Resistance genes against FCZ were in the transcription factors (HAP2, HAP5), zinc finger (NRG1), cytochrome P450 (ERG11), and Myb-like DNA-binding domain (REB1). The most frequent resistance genes against ITZ were cytochrome P450 (ERG5 and ERG11) and a transcription factor (HAP5). DOP3.1 also consisted of 26 candidate resistance genes against azoles. Resistance genes against the azole group belong to the ABC transporter transmembrane superfamily. Resistance genes against FCZ belong to cytochrome P450 (ERG11), the zinc finger (NRG1), and the CCAAT binding transcription factor (HAP2). Resistance genes belonging to cytochrome P450 (ERG5) were found against ITZ. This research provides the first report of C. neoformans (serotype A) in zebra dove excreta, drug susceptibility to a resistant strain, and identification of resistance genes. Farm sanitation should be strictly applied, and immunocompetent people should avoid contact with zebra dove excreta. Full article

Tan sheep outperform Dorper sheep in meat-quality traits, including muscle fiber characteristics and fatty acid composition, while Dorper sheep excel in carcass weight. However, the molecular mechanisms underlying these breed-specific traits, especially gut microbiota–bile acid (BA) interactions, remain poorly understood. As host–microbiota co-metabolites, BAs are converted by colonic microbiota via bile salt hydrolase (BSH) and dehydroxylases into secondary BAs, which activate BA receptors to regulate host lipid and glucose metabolism. This study analyzed colonic BA profiles in 8-month-old Tan and Dorper sheep, integrating microbiome and longissimus dorsi muscle transcriptome data to investigate the gut–muscle axis in meat-quality and carcass trait regulation. Results showed that Tan sheep had 1.6-fold higher secondary BA deoxycholic acid (DHCA) levels than Dorper sheep (p < 0.05), whereas Dorper sheep accumulated conjugated primary BAs glycocholic acid (GCA) and tauro-α-muricholic acid (p < 0.05). Tan sheep exhibited downregulated hepatic BA synthesis genes, including cholesterol 7α-hydroxylase (CYP7A1) and 27-hydroxylase (CYP27A1), alongside upregulated transport genes such as bile salt export pump (BSEP), sodium taurocholate cotransporting polypeptide (NTCP), and ATP-binding cassette subfamily B member 4 (ABCB4), with elevated gut BSH activity (p < 0.05). DHCA was strongly correlated with g_Ruminococcaceae_UCG-014, ENSOARG00000001393, and ENSOARG00000016726, muscle fiber density, diameter, and linoleic acid (C18:2n6t) (|r| > 0.5, p < 0.05). In contrast, GCA was significantly associated with g_Lachnoclostridium_10, g_Rikenellaceae_RC9_gut_group, ENSOARG0000001232, carcass weight, and net meat weight (|r| > 0.5, p < 0.05). In conclusion, breed-specific colonic BA profiles were shaped by host–microbiota interactions, with DHCA potentially promoting meat quality in Tan sheep via regulation of muscle fiber development and fatty acid deposition, and GCA influencing carcass traits in Dorper sheep. This study provides novel insights into the gut microbiota–bile acid axis in modulating ruminant phenotypic traits. Full article

The development of resistance to standard cytostatics, such as 5-fluorouracil (5-FU), significantly limits the efficacy of colon cancer therapy, prompting the search for novel anticancer agents, particularly among natural compounds. This study evaluated the anticancer effects of isorhamnetin, a plant-derived flavonol, and its ability to modulate the expression of drug-resistance-related biomarkers in SW-480 and HT-29 colon cancer cells, with a focus on ATP-binding cassette (ABC) transporters. Isorhamnetin demonstrated strong cytotoxic and proapoptotic activity on both cell lines, while showing lower toxicity toward normal HaCaT cells. In addition to suppressing the mRNA expression of drug-metabolizing enzymes (CYP1A1 and CYP1B1), isorhamnetin significantly reduced the mRNA levels of multidrug resistance-associated proteins 1 and 5 (MRP1 and MRP5), as well as the P-glycoprotein (P-gp) level in SW-480 and HT-29 cells. Molecular docking analysis revealed a high binding affinity of isorhamnetin to CYP1A1, CYP1B1, P-gp, MRP1, MRP5, and glutathione S-transferase (GST) proteins, with stronger interactions than those observed for 5-FU, suggesting potential interference with their function. These results provide a solid basis for future investigations to confirm the therapeutic potential of isorhamnetin as a modulator of drug resistance in colon cancer cells. Full article

Multidrug resistance (MDR) poses a significant challenge in cancer therapy, often leading to treatment failure and relapse. ATP-binding cassette (ABC) transporters, particularly ABCG2, play a pivotal role in MDR development by actively expelling chemotherapeutic agents from cancer cells. This study investigates the effects of two groups of primaquine derivatives—fumardiamides (1a–d) and bis-ureas (2a, b), both bearing halogenated benzene rings—on the activity of P-glycoprotein (P-gp) and ABCG2. Their potential to reverse MDR was evaluated through a series of functional assays aimed at comparing transporter–compound interactions. The results indicated that fumardiamide derivatives, specifically 1a, 1b, and 1d, exhibited potent inhibition of ABCG2 while having no effect on P-gp, demonstrating a selective mode of action. The tested derivatives displayed low to moderate cytotoxicity and did not affect ABCG2 expression or localization. Moreover, these compounds enhanced the sensitivity of drug-resistant cancer cell lines to mitoxantrone, underscoring their potential to overcome ABCG2-mediated MDR. These findings suggest that chemical modifications of primaquine, particularly the incorporation of fumardiamide moieties, confer novel biological properties, providing promising leads for the development of selective ABCG2 inhibitors. Full article

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a severe hepatocellular cholestasis due to biallelic variations in the ABCB11 (ATP-binding cassette B11) gene encoding the canalicular bile salt export pump (BSEP). Some missense variants identified in patients with PFIC2 do not traffic properly to the canalicular membrane. However, 4-phenybutyrate (4-PB) has been shown in vitro to partially correct the mis-trafficking of selected variants, resulting in an improvement of the medical conditions of corresponding PFIC2 patients. Herein, we report the ability of 4-PB analogous or homologous drugs and of non-4-PB related chemical correctors to rescue the canalicular expression and the activity of the folding-defective Abcb11^R1128C variant. New compounds, either identified by screening a chemical library or designed by structural homology with 4-PB (or its metabolites) and synthesized, were evaluated in vitro for their ability to (i) correct the canalicular localization of Abcb11^R1128C after transfection in hepatocellular polarized cell lines; (ii) restore the ³H-taurocholate transport of the Abcb11^R1128C protein in Madin–Darby canine kidney (MDCK) cells stably co-expressing Abcb11 and the sodium taurocholate co-transporting polypeptide (Ntcp/Slc10A1). Glycerol phenylbutyrate (GPB), phenylacetate (PA, the active metabolite of 4-PB), 3-hydroxy-2-methyl-4-phenylbutyrate (HMPB, a 4-PB metabolite analog chemically synthesized in our laboratory) and 4-oxo-1,2,3,4-tetrahydro-naphthalene-carboxylate (OTNC, from the chemical library screening) significantly increased the proportion of canalicular Abcb11^R1128C protein. GPB, PA, ursodeoxycholic acid (UDCA), alone or in combination with 4-PB, suberoylanilide hydroxamic acid (SAHA), C18, VX-445, and/or VX-661, significantly corrected both the traffic and the activity of Abcb11^R1128C. Such correctors could represent new pharmacological insights for improving the condition of patients with ABCB11 deficiency due to missense variations affecting the transporter’s traffic. Full article

To investigate the effects and underlying mechanisms of the Chinese herbal medicine berberine hydrochloride (BBH) on the pharmacokinetics of the antibiotic ciprofloxacin hydrochloride (CIP) in yellow catfish (Pelteobagrus fulvidraco), this study established two experimental groups: CIP alone and CIP combined with BBH. After administering the two treatment groups, we analyzed the pharmacokinetic characteristics and tissue distribution of CIP in yellow catfish, as well as the differences in the expression levels of two key genes involved in drug disposition—ABCB4 (ATP-binding cassette subfamily B member 4, related to drug transport) and CYP3A40 (cytochrome P450 3A40, related to drug metabolism)—in the intestinal tract. The results demonstrated that co-administration of CIP and BBH increased the maximum concentration (C_max) and area under the concentration–time curve (AUC) of CIP while reducing its total body clearance (CL/F). Regarding gene expression, the combined treatment significantly downregulated ABCB4 expression in the intestine at certain time points compared to CIP alone, whereas CYP3A40 expression showed a non-significant decreasing trend. These findings suggest that BBH may enhance the absorption of CIP in yellow catfish by suppressing ABCB4 expression, thereby improving therapeutic efficacy at the same dosage. Full article

Familial Mediterranean fever (FMF) is an autoinflammatory genetic disorder characterized by recurrent fevers and inflammation of the serous membranes in the abdomen, lungs, and joints. Currently, the standard treatment of FMF includes colchicine, which is an alkaloid, derived from Colchicum autumnale. Colchicine’s efficacy in FMF is well-established as it is used both to prevent acute attacks and reduce the risk of long-term complications. However, despite these available treatments, 5–10% of patients exhibit resistance to the drug. It has been demonstrated that polymorphisms in several genes involved in inflammation can influence treatment outcomes and the risk of FMF complications like amyloidosis. Among them, some research focused on polymorphism affecting adenosine triphosphate (ATP)-binding cassette sub-family B member 1 (ABCB1) gene encoding for P-glycoprotein. P-glycoprotein is considered a key transporter protein as it regulates the absorption, distribution, and excretion of several drugs, including colchicine. In diseases like FMF, ABCB1 polymorphisms have been shown to affect the response to colchicine, potentially leading to treatment resistance or altered toxicity. Based on this evidence, this systematic review aims to analyze available evidence on ABCB1-mediated colchicine transport and its clinical implications in FMF, showing how relevant ABCB1 variants are in response to therapy. Full article

Mesenchymal stem cells (MSCs) are a family of multipotent stem cells that show self-renewal under proliferation, multilineage differentiation, immunomodulation, and trophic function. Thus, these cells, such as adipose tissue-derived mesenchymal stem cells (ADSCs), bone marrow-derived MSCs (BM-MSCs), and umbilical cord-derived mesenchymal stem cells (UC-MSCs), carry great promise for novel clinical treatment options. However, the challenges associated with the isolation of MSCs and the instability of their in vitro expansion remain significant barriers to their clinical application. The plasma membrane-spanning P-glycoprotein ATP-binding cassette subfamily B member 5 positive MSCs (ABCB5⁺ MSCs) derived from human skin specimens offer a distinctive advantage over other MSCs. They can be easily extracted from the dermis and expanded. In culture, ABCB5⁺ MSCs demonstrate robust innate homeostasis and a classic trilineage differentiation. Additionally, their ability to modulate the recipients’ immune system highlights their potential for allogeneic applications in regenerative medicine. In this review, we primarily discuss the differentiation potential of ABCB5⁺ MSCs and their perspectives in regenerative medicine. Full article

Analyzing the genetic architecture of hereditary forms of diabetes in different populations is a critical step toward optimizing diagnostic and preventive algorithms. This requires consideration of regional and population-specific characteristics, including the spectrum and frequency of pathogenic variants in targeted genes. As part of this study, we used a custom-designed NGS panel to screen for mutations in 28 genes associated with the pathogenesis of hereditary diabetes mellitus in 506 unrelated patients from Russia. The study identified 180 pathogenic or likely pathogenic variants across 13 genes (GCK, HNF1A, HNF1B, HNF4A, ABCC8, INS, INSR, KCNJ11, PAX4, PDX1, ZFP57, BLK, WFS1), representing 46.44% of the analyzed cohort (235 individuals). The glucokinase gene (GCK) had the highest number of identified variants, with 111 variants detected in 161 patients, 20 of which were identified for the first time. In the tissue-specific transcription factor genes HNF1A, HNF4A, and HNF1B, 34 variants were found in 38 patients, including 13 that were previously unreported. Seventeen variants were identified in the ABCC8 gene, which encodes the ATP-binding cassette transporter 8 of subfamily C, each found in a different patient; four of these were novel discoveries. Nine pathogenic or likely pathogenic variants were identified in the insulin gene (INS) and its receptor gene (INSR), including four previously unreported variants. Additionally, we identified 10 previously unreported variants in six other genes among 11 patients. Variants in the genes GCK, HNF1A, HNF1B, HNF4A, ABCC8, INS, and INSR were the main contributors to the genetic pathogenesis of hereditary diabetes mellitus in the Russian cohort. These findings enhance our understanding of the molecular mechanisms underlying the disease and provide a solid basis for future studies aimed at improving diagnostic accuracy and advancing personalized therapeutic strategies. This knowledge provides a foundation for developing region-specific genetic testing algorithms and personalized therapeutic strategies, which are critical for future initiatives in precision medicine. Full article

Background: The multiple drug-resistant phenomenon has long since plagued the effectiveness of various chemotherapies used in the treatment of patients with glioblastoma (GBM), which is still incurable to this day. ATP-binding cassette (ABC) transporters function as drug transporters and have been touted to be the main culprits in developing resistance to xenobiotic drugs in GBM. Methods: This review systematically analyzed the efficacy of ABC transporters against various anticancer drugs from 16 studies identified from five databases (PubMed, Medline, Embase, Scopus, and ScienceDirect). Results: Inhibition of ABC transporters, especially ABCB1, improved drug efficacies. Staple GBM phenotypes, such as GBM stem cells and increased activation of the PI3K/Akt/NF-κB pathway, have been implicated in the expression of several ABC transporters. Using the datasets in The Cancer Genome Atlas and Gene Expression Omnibus, we found upregulated ABC transporters that either negatively impacted survival in univariate analyses (ABCA1, ABCA13, ABCB9, ABCD4) or were independent negative prognosis factors for patients with GBM (ABCA13, ABCB9). Our multivariate analysis further demonstrated three ABC transporters, ABCA13 (Hazard Ratio (HR) = 1.31, p = 0.017), ABCB9 (HR = 1.26, p = 0.03), and ABCB5 (HR = 0.77, p = 0.016), with the administration of alkylating agents (HR = 0.41, p < 0.001), were independent negative prognosis factors for patients with GBM. Conclusions: These findings reinforce the important role played by ABC transporters, particularly by ABCA13, ABCB9, and ABCB1, which could be potential targets that warrant further evaluations for alternate strategies to augment the effects of existing alkylating agents and xenobiotic drugs. Full article

Aging and apolipoprotein E4 (APOE4) are the two most significant risk factors for late-onset Alzheimer’s disease (LOAD). Compared to APOE3, APOE4 disrupts cholesterol homeostasis, increases cholesteryl esters (CEs), and exacerbates neuroinflammation in brain cells, including microglia. Targeting CEs and neuroinflammation could be a novel strategy to ameliorate APOE4-dependent phenotypes. Toll-like receptor 4 (TLR4) is a key macromolecule in inflammation, and its regulation is associated with the cholesterol content of lipid rafts in cell membranes. We previously demonstrated that in normal microglia expressing APOE3, inhibiting the cholesterol storage enzyme acyl-CoA:cholesterol acyltransferase 1 (ACAT1/SOAT1) reduces CEs, dampened neuroinflammation via modulating the fate of TLR4. We also showed that treating myelin debris-loaded normal microglia with ACAT inhibitor F12511 reduced cellular CEs and activated ABC transporter 1 (ABCA1) for cholesterol efflux. This study found that treating primary microglia expressing APOE4 with F12511 also reduces CEs, activates ABCA1, and dampens LPS-dependent NFκB activation. In vivo, two-week injections of nanoparticle F12511, which consists of DSPE-PEG₂₀₀₀, phosphatidylcholine, and F12511, to aged female APOE4 mice reduced TLR4 protein content and decreased proinflammatory cytokines, including IL-1β in mice brains. Overall, our work suggests nanoparticle F12511 is a novel agent to ameliorate LOAD. Full article

Background and Objective: ATP-binding cassette (ABC) transporters are prominent drug targets due to their highly efficient trafficking capabilities and their significant physiological and clinical roles. Gaining insight into their biophysical and biomechanistic properties is crucial to maximize their pharmacological potential. Materials and Methods: In this study, we present the biochemical and biophysical characterization, and phylogenetic analysis of the domains of Mycobacterium tuberculosis (M. tuberculosis) ABC transporters: the exporter Rv1348 (IrtA) and the importer system Rv1349-Rv2895c (IrtB-Rv2895c), both involved in siderophore-mediated iron uptake. Results: Our findings reveal that the substrate-binding domain (SBD) of IrtA functions as an active monomer, while Rv2895c, which facilitates the uptake of siderophore-bound iron, exists in a dynamic equilibrium between dimeric and monomeric forms. Furthermore, ATP binding induces the dimerization of the ATPase domains in both IrtA (ATPase I) and IrtB (ATPaseII), but only the ATPase domain of IrtA (ATPase I) is active independently. We also analyzed the stability of substrate binding to the domains of the two transporters across varying temperature and pH ranges, revealing significant shifts in their activity under different conditions. Our study highlights the conformational changes that accompany substrate interaction with the transporter domains, providing insights into the fundamental mechanism required for the translocation of siderophore to the extracytoplasmic milieu by IrtB and, subsequently, import of their ferrated forms by the IrtB-Rv2895c complex. Phylogenetic analyses based on ATPase domains reveal that IrtA shares features with both archaeal and eukaryotic transporters, while IrtB is unique to mycobacterial species. Conclusions: Together, these findings provide valuable insights, which could accelerate the development of intervention strategies for this critical pathway pivotal in the progression of M. tuberculosis infection. Full article

ATP-binding cassette (ABC) transporters, particularly those of subfamily B, are involved in cell detoxification, multidrug resistance, drug treatment pharmacodynamics, and also ecological adaptation. In this regard, ABCB transporters may play a decisive role in the co-evolution between plants and herbivores. Cardenolides, toxic steroid glycosides, are secondary plant metabolites that defend plants against herbivores by targeting their sodium–potassium ATPase. Despite their toxicity, several herbivorous insects such as the large milkweed bug (Oncopeltus fasciatus) have evolved adaptations to tolerate cardenolides and sequester them for their own defense. We investigate the role of two ABCB transporters of O. fasciatus for the paracellular transport of cardenolides by docking simulations and ATPase assays. Cardenolide binding of OfABCB1 and OfABCB2 is predicted by docking simulations and calculated binding energies are compared with substrate specificities determined in ATPase assays. Both tested ABCB transporters showed activity upon exposure to cardenolides and Km values that agreed well with the predictions of our docking simulations. We conclude that docking simulations can help identify transporter binding regions and predict substrate specificity, as well as provide deeper insights into the structural basis of ABC transporter function. Full article

For the first time, we used an in vitro vs. in vivo experimental design to reveal core pathways under nitrogen deficiency (ND) in an evergreen tree crop. These pathways were related to lignin biosynthesis, cell redox homeostasis, the defense response to fungus, the response to Karrikin, amino acid transmembrane transport, the extracellular region, the cellular protein catabolic process, and aspartic-type endopeptidase activity. In addition, the mitogen-activated protein kinase pathway and ATP synthase (ATP)-binding cassette transporters were significantly upregulated under nitrogen deficiency in vitro and in vivo. Most of the MAPK downstream genes were related to calcium signaling (818 genes) rather than hormone signaling (157 genes). Moreover, the hormone signaling pathway predominantly contained auxin- and abscisic acid-related genes, indicating the crucial role of these hormones in ND response. Overall, 45 transcription factors were upregulated in both experiments, 5 WRKYs, 3 NACs, 2 MYBs, 2 ERFs, HD-Zip, RLP12, bHLH25, RADIALIS-like, and others, suggesting their ND regulation is independent from the presence of a root system. Gene network reconstruction displayed that these transcription factors participate in response to fungus/chitin, suggesting that nitrogen response and pathogen response have common regulation. The upregulation of lignin biosynthesis genes, cytochrome genes, and strigalactone response genes was much more pronounced under in vitro ND as compared to in vivo ND. Several cell wall-related genes were closely associated with cytochromes, indicating their important role in flavanols biosynthesis in tea plant. These results clarify the signaling mechanisms and regulation of the response to nitrogen deficiency in evergreen tree crops. Full article