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1.
Cell Biol Int ; 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39252385

RESUMO

Independent risk factors for sepsis-associated acute kidney injury (S-AKI) patients include elevated lactate levels, but the specific mechanism remains unclear. Recently, An et al. discovered that excessive acetylation and inactivation of PDHA1 lead to overproduction of lactate, resulting in mitochondrial fragmentation, ATP depletion, excessive mtROS production, and mitochondrial apoptosis, thereby exacerbating AKI in sepsis. Therefore, understanding the pathophysiological processes of mitochondrial function and lactate generation in SAKI is essential and can aid in the development of novel therapeutic strategies. This review elucidates the pathological mechanisms of mitochondrial autophagy and dynamics in AKI. We also discuss the sources of lactate in SAKI and some consequences of lactonization, which may provide new strategies for improving renal injury and delaying the progression of these diseases.

2.
Cell Death Discov ; 10(1): 395, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39237520

RESUMO

Abdominal aortic aneurysms (AAA) are a significant health concern in developed countries due to their considerable mortality rate. The crucial factor of the progression of AAA is the release of neutrophils and neutrophil extracellular traps (NETs). Magnetic particle imaging (MPI) is a new imaging technique that offers the capability to detect superparamagnetic iron oxide nanoparticles (SPION) with exceptional sensitivity. We aimed to investigate the functional imaging of MPI for the detection and monitoring of neutrophil infiltration within AAA. A novel multimodal imaging agent targeting neutrophils, PEG-Fe3O4-Ly6G-Cy7 nanoparticles (Ly6G NPs), were designed by coupling Fe3O4 nanoparticles with Ly6G antibodies and Cy7. The targeting and sensitivity of Ly6G NPs were assessed using MPI and fluorescence imaging (FLI) in the AAA mouse model. After the inhibition of NETosis, the degree of neutrophil infiltration and AAA severity were assessed using MPI with Ly6G NPs. Ly6G NPs accurately localized and quantitatively analyzed AAA lesion sites in mice using MPI/FLI/CT. Compared to the control group, elevated MPI and FLI signal intensities were detected at the abdominal aortic lesion site, and neutrophil infiltration and NETs accumulation were detected by histological analysis in the AAA models. After the inhibition of NETs accumulation in vivo, pathological damage in the abdominal aorta was significantly reduced, along with a decrease in the accumulation of Ly6G NPs and MPI signals. This multimodal MPI strategy revealed that nanoparticles targeting Ly6G can be used to detect neutrophil infiltration within AAA and monitor AAA severity.

4.
Int J Gen Med ; 17: 4127-4140, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39308965

RESUMO

Objective: To explore how non-surgical esophageal cancer patients can identify high-risk factors for radiation-induced pneumonitis after receiving radiotherapy. Methods: We retrospectively included 228 esophageal cancer patients who were unable to undergo surgical treatment but received radiotherapy for the first time. By retrospective analysis and identifying potential risk factors for symptomatic radiation-induced pneumonitis (ie ≥grade 2), as well as delineating the affected lung as an area of interest on localized CT and extracting radiomics features, along with extracting dosimetric parameters from the affected lung area. After feature screening, patients were randomly divided into training and testing sets in a 7-to-3 ratio, and a prediction model was established using machine learning algorithms. Finally, the receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to validate the predictive performance of the model. Results: A total of 54 cases of symptomatic radiation pneumonitis occurred in this study, with a total incidence rate of 23.68%. The results of multivariate analysis showed that the occurrence of symptomatic radiation pneumonitis was significantly correlated with the mean lung dose (MLD), esophageal PTVD90, esophageal PTVV50, V5, V10, V15, and V20 in patients. The machine learning prediction model constructed based on candidate prediction variables has a prediction performance interval between 0.751 (95% CI: 0.700-0.802) and 0.891 (95% CI: 0.840-0.942) in the training and validation sets, respectively. Among them, the RFM algorithm has the best prediction performance for radiation-induced pneumonitis, with 0.891 (95% CI: 0.840-0.942) and 0.887 (95% CI: 0.836-0.938) in the training and validation sets, respectively. Conclusion: The combination of localization CT radiomics features and diseased lung dosimetry parameters has good predictive value for radiation-induced pneumonitis in esophageal cancer patients after radiotherapy. Especially, the radiation-induced pneumonitis prediction model constructed using RF algorithm can be more effectively used to guide clinical decision-making in esophageal cancer patients.

5.
Pathol Res Pract ; 262: 155564, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39216322

RESUMO

Colorectal cancer (CRC) remains a significant global health challenge, marked by increasing incidence and mortality rates in recent years. The pathogenesis of CRC is complex, involving chronic inflammation of the intestinal mucosa, heightened immunoinflammatory responses, and resistance to apoptosis. The suppressor of cytokine signaling (SOCS) family, comprised of key negative regulators within cytokine signaling pathways, plays a crucial role in cell proliferation, growth, and metabolic regulation. Deficiencies in various SOCS proteins can trigger the activation of the Janus kinase (JAK) and signal transducers and activators of transcription (STAT) pathways, following the binding of cytokines and growth factors to their receptors. Mounting evidence indicates that SOCS proteins are integral to the development and progression of CRC, positioning them as promising targets for novel anticancer therapies. This review delves into the structure, function, and molecular mechanisms of SOCS family members, examining their roles in cell proliferation, apoptosis, migration, epithelial-mesenchymal transition (EMT), and immune modulation. Additionally, it explores their potential impact on the regulation of CRC immunotherapy, offering new insights and perspectives that may inform the development of innovative therapeutic strategies for CRC.


Assuntos
Neoplasias Colorretais , Transdução de Sinais , Proteínas Supressoras da Sinalização de Citocina , Humanos , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/imunologia , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Transdução de Sinais/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Proliferação de Células/fisiologia , Apoptose/fisiologia , Animais
9.
Virol J ; 21(1): 198, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39187884

RESUMO

Human enteroviruses are highly prevalent world-wide. Up to more than 100 subtypes of enteroviruses can cause several diseases, including encephalitis, meningitis, myocarditis, hand-foot-mouth disease, conjunctivitis, respiratory diseases, and gastrointestinal diseases, thus posing a great threat to human health. This study aimed to investigate the epidemiological characteristics of enterovirus in children in Hangzhou, China before and after the COVID-19 outbreak. Systematic monitoring of enterovirus infections was performed by collecting samples from the children admitted to the inpatient wards and outpatient departments in the Children's Hospital, Zhejiang University School of Medicine, between January 2019 and May 2023. A commercial real-time RT PCR kit was utilized to detect enteroviruses. Among the 34,152 samples collected, 1162 samples, accounting for 3.4% of the samples, were tested positive for enteroviruses. The annual positive rates of the enteroviruses were 5.46%, 1.15%, 4.43%, 1.62%, and 1.96% in 2019, 2020, 2021, 2022, and May 2023, respectively. The positivity rate of the enteroviruses was highest among children aged 3-5 years and 5-7 years. Moreover, the monthly positivity rate of enterovirus infection ranged from 0.32% to 10.38%, with a peak in June and July. Serotypes, especially EV71 and CA16, causing severe symptoms such as HFMD, were decreasing, while the proportion of unidentified serotypes was on the rise. The incidence of enteroviruses in Hangzhou was higher in children aged 1-3 years and 7-18 years.


Assuntos
Infecções por Enterovirus , Enterovirus , Humanos , China/epidemiologia , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Criança , Pré-Escolar , Lactente , Masculino , Enterovirus/classificação , Enterovirus/genética , Enterovirus/isolamento & purificação , Feminino , Adolescente , COVID-19/epidemiologia , COVID-19/virologia , Recém-Nascido , Estações do Ano , SARS-CoV-2/genética , SARS-CoV-2/classificação , SARS-CoV-2/isolamento & purificação , Prevalência
10.
BMC Genomics ; 25(1): 774, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39118048

RESUMO

BACKGROUND: Pseudomonas juntendi is a newly identified opportunistic pathogen, of which we have limited understanding. P. juntendi strains are often multidrug resistant, which complicates clinical management of infection. METHODS: A strain of Pseudomonas juntendi (strain L4326) isolated from feces was characterized by MALDI-TOF-MS and Average Nucleotide Identity BLAST. This strain was further subject to whole-genome sequencing and Maximum Likelihood phylogenetic analysis. The strain was phenotypically characterized by antimicrobial susceptibility testing and conjugation assays. RESULTS: We have isolated the novel P. juntendi strain L4236, which was multidrug resistant, but retained sensitivity to amikacin. L4236 harbored a megaplasmid that encoded blaOXA-1 and a novel blaIMP-1 resistance gene variant. P. juntendi strain L4236 was phylogenetically related to P. juntendi strain SAMN30525517. CONCLUSION: A rare P. juntendi strain was isolated from human feces in southern China with a megaplasmid coharboring blaIMP-1-like and blaOXA-1. Antimicrobial selection pressures may have driven acquisition of drug-resistance gene mutations and carriage of the megaplasmid.


Assuntos
Farmacorresistência Bacteriana Múltipla , Filogenia , Plasmídeos , Pseudomonas , beta-Lactamases , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Plasmídeos/genética , beta-Lactamases/genética , Farmacorresistência Bacteriana Múltipla/genética , China , Humanos , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Sequenciamento Completo do Genoma , Fezes/microbiologia , Cromossomos Bacterianos/genética , Genoma Bacteriano
12.
Front Endocrinol (Lausanne) ; 15: 1430720, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39076513

RESUMO

Background: Bile acids (BAs), products of gut microbiota metabolism, have long been implicated in atherosclerotic disease pathogenesis. Characterizing the serum bile acid profile and exploring its potential role in carotid atherosclerosis (CAS) development are crucial tasks. Methods: In this study, we recruited 73 patients with CAS as the disease group and 77 healthy individuals as the control group. We systematically measured the serum concentrations of 15 bile acids using ultrahigh-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Multivariate logistic regression and least absolute shrinkage and selection operator (LASSO) regression were applied to analyze the impact of bile acids on the disease and select the key BAs. The possible molecular mechanism was elucidated by network pharmacology. Results: (1) The BA profile of patients with CAS significantly differed. (2) Multifactorial logistic regression analysis identified elevated levels of GCDCA (OR: 1.01, P < 0.001), DCA (OR: 1.01, P = 0.005), and TDCA (OR: 1.05, P = 0.002) as independent risk factors for CAS development. Conversely, GCA (OR: 0.99, P = 0.020), LCA (OR: 0.83, P = 0.002), and GUDCA (OR: 0.99, P = 0.003) were associated with protective effects against the disease. GCA, DCA, LCA, and TDCA were identified as the four key BAs. (3) TNF, FXR, GPBAR1, ESR1 and ACE were predicted to be targets of BAs against AS. These four BAs potentially impact AS progression by triggering signaling pathways, including cAMP, PPAR, and PI3K-AKT pathways, via their targets. Conclusion: This study offers valuable insights into potential therapeutic strategies for atherosclerosis that target bile acids.


Assuntos
Ácidos e Sais Biliares , Doenças das Artérias Carótidas , Metabolômica , Farmacologia em Rede , Humanos , Ácidos e Sais Biliares/metabolismo , Ácidos e Sais Biliares/sangue , Masculino , Feminino , Doenças das Artérias Carótidas/metabolismo , Doenças das Artérias Carótidas/tratamento farmacológico , Doenças das Artérias Carótidas/sangue , Pessoa de Meia-Idade , Metabolômica/métodos , Idoso , Estudos de Casos e Controles , Biomarcadores/sangue , Receptores Acoplados a Proteínas G/metabolismo , Espectrometria de Massas em Tandem
13.
Pest Manag Sci ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39073206

RESUMO

BACKGROUND: Phytophthora spp. represent a pivotal genus of plant pathogens with a global distribution, exerting significant deleterious effects on food safety and forestry ecosystems. Numerous pathogenic and invasive Phytophthora species, introduced through imported fruits, have been frequently detected at Chinese ports. With the rise in global trade activities, the plant quarantine of imported fruits is becoming increasingly important but challenging. Fast, simple, and labor-saving techniques are necessary and anticipated. RESUITS: A polymerase chain reaction restriction fragment length polymorphism capillary electrophoresis (PCR-RFLP-CE) technology-based quarantine approach was developed for 16 Phytophthora species associated with the imported fruits in China. The Ypt1 gene, exhibiting abundant interspecific variations, was selected as the marker gene for PCR. The restriction endonuclease AluI was proven to be capable and compatible in simultaneously separating different Phytophthora species during CE. By combining with a fast and efficient DNA extraction kit, the developed PCR-RFLP-CE technique was successfully applied to identify Phytophthora species in artificially infested fruits. CONCLUSION: We provide a quick, practical, and high-throughput detection approach for hazardous and invasive Phytophthora species associated with imported fruits in China. This strategy can give good convenience and technological support for carrying out massive quarantine activities at Chinese ports. © 2024 Society of Chemical Industry.

14.
Aging (Albany NY) ; 16(14): 11339-11358, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-39029955

RESUMO

BACKGROUND: Ferroptosis is associated with cancer progression and has a promising application for treating hepatocellular carcinoma (HCC). Long non-coding RNA (lncRNA) participates widely in the regulation of ferroptosis, but the key lncRNA regulators implicated in ferroptosis and their molecular mechanisms remain to be identified. METHODS: Bioinformatic analysis was performed in R based on The Cancer Genome Atlas Program (TCGA) public database. The relative expression of genes was detected by real-time quantitative PCR. Cell viability was assessed by the CCK8 assay. The cell cycle and apoptosis were detected by flow cytometry. Migration and invasion of HCC cells were detected by Transwell assay and wound healing assay. Expression of relevant proteins was detected by Western blotting. A dual-luciferase reporter assay was used to detect interactions between PART1 (or SLC7A11) and miR-490-3p. RESULTS: The PART1/miR-490-3p/SLC7A11 axis was identified as a potential regulatory pathway of ferroptosis in HCC. PART1 silencing reduced HCC cell proliferation, migration, and metastasis and promoted apoptosis and erastin-reduced ferroptosis. Further investigation revealed that PART1 acted as a competitive endogenous RNA (ceRNA) for miR-490-3p to enhance SLC7A11 expression. Overexpression of miR-490-3p downregulated the expression of SLC7A11, inhibiting the proliferation, invasion, and metastasis of HCC cells while promoting apoptosis and erastin-induced ferroptosis. Knockdown of PART1 in HCC cells significantly improved the sensitivity of HCC cells to sorafenib. CONCLUSION: Our results revealed that the PART1/miR-490-3p/SLC7A11 axis enhances HCC cell malignancy and suppresses ferroptosis, which provides a new perspective for understanding of the function of long chain non-coding RNAs in HCC. The PART1/miR-490-3p/SLC7A11 axis may be target for improving sorafenib sensitivity in HCC.


Assuntos
Sistema y+ de Transporte de Aminoácidos , Carcinoma Hepatocelular , Ferroptose , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas , MicroRNAs , RNA Longo não Codificante , Ferroptose/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/metabolismo , Sistema y+ de Transporte de Aminoácidos/genética , Sistema y+ de Transporte de Aminoácidos/metabolismo , Linhagem Celular Tumoral , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proliferação de Células/genética , Carcinogênese/genética , Movimento Celular/genética , Apoptose/genética , Sorafenibe/farmacologia
15.
Risk Manag Healthc Policy ; 17: 1417-1426, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38835952

RESUMO

Purpose: This study aimed to investigate the cognitive evaluation level of ICU nurses in Guizhou Province, China, on the sensitivity indicators of nursing quality for ECMO patients. Patients and Methods: This was a cross-sectional observational study conducted in Guizhou Province, China, from May to July 2023, 259 ICU nurses were surveyed. Objective sampling method was used to select the participants from 10 hospitals in Guizhou Province that carried out ECMO. Data were collected through questionnaire survey. Two researchers checked and recorded Epidata 3.1. SPSS 25.0 was used for statistical analysis of the data, and frequency, mean and component ratio were used for descriptive statistical analysis. The importance rating was used to reflect the degree of nurses' agreement with the indicators. Results: The results of this study showed that 79.1% of the 253 ICU nurses in Guizhou Province, China, had not participated in training and courses related to indicators of quality of care evaluation for ECMO patients. The main way for ICU nurses to acquire knowledge related to indicators of quality of care sensitivity for ECMO patients was departmental training, which accounted for 87.4%. And the other ways, in descending order, were public, the matic lectures or academic conferences, journals and magazines; their evaluation scores of the importance of most of the quality of care sensitivity indicators for ECMO patients was moderate, with the scores ranging from 73 to 150. Among them, the range of importance evaluation scores for each indicator was 4.01 ~ 4.48. Conclusion: The overall cognitive evaluation of ICU nurses in Guizhou Province, China, on most sensitivity indicators of quality of care for ECMO patients was moderate, and there is a general lack of systematic courses and training on the knowledge related to ECMO care quality sensitive indicators.

16.
FASEB J ; 38(11): e23729, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38847786

RESUMO

Diabetic nephropathy (DN) is one of the common microvascular complications in diabetic patients. Marrow mesenchymal stem cells (MSCs) have attracted attention in DN therapy but the underlying mechanism remains unclear. Here, we show that MSC administration alleviates high glucose (HG)-induced human kidney tubular epithelial cell (HK-2 cell) injury and ameliorates renal injury in DN mice. We identify that Smad2/3 is responsible for MSCs-regulated DN progression. The activity of Smad2/3 was predominantly upregulated in HG-induced HK-2 cell and DN mice and suppressed with MSC administration. Activation of Smad2/3 via transforming growth factor-ß1 (TGF-ß1) administration abrogates the protective effect of MSCs on HG-induced HK-2 cell injury and renal injury of DN mice. Smad2/3 has been reported to interact with methyltransferase of N6-methyladenosine (m6A) complex and we found a methyltransferase, Wilms' tumor 1-associating protein (WTAP), is involved in MSCs-Smad2/3-regulated DN development. Moreover, WTAP overexpression abrogates the improvement of MSCs on HG-induced HK-2 cell injury and renal injury of DN mice. Subsequently, α-enolase (ENO1) is the downstream target of WTAP-mediated m6A modification and contributes to the MSCs-mediated regulation. Collectively, these findings reveal a molecular mechanism in DN progression and indicate that Smad2/3/WTAP/ENO1 may present a target for MSCs-mediated DN therapy.


Assuntos
Nefropatias Diabéticas , Células-Tronco Mesenquimais , Proteína Smad2 , Proteína Smad3 , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Animais , Células-Tronco Mesenquimais/metabolismo , Proteína Smad2/metabolismo , Camundongos , Humanos , Proteína Smad3/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Adenosina/metabolismo , Adenosina/análogos & derivados , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Transdução de Sinais , Metiltransferases/metabolismo , Metiltransferases/genética , Transplante de Células-Tronco Mesenquimais/métodos , Fator de Crescimento Transformador beta1/metabolismo , Linhagem Celular
17.
18.
Foodborne Pathog Dis ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38625018

RESUMO

Salmonella Typhimurium (STM) is an important zoonotic Gram-negative pathogen that can cause infection in a variety of livestock and poultry. Meanwhile, as an important foodborne pathogen, the bacterium can survive in various stressful environments and transmits through the fecal-oral route, posing a serious threat to global food safety. To investigate the roles of STM1863, a member of the DUFs protein family, involved in STM environmental adaptation, biofilm formation, and virulence. We analyzed the molecular characteristics of the protein encoded by STM1863 gene and examined intra- and extracellular expression levels of STM1863 gene in mouse macrophages. Furthermore, we constructed STM1863 gene deletion and complementation strains and determined its environmental adaptation under stressful conditions such as acid, alkali, high salt, bile salt, and oxidation. And the capacity of biofilm formation and pathogenicity of those strains were analyzed and compared. In addition, the interaction between the promoter of STM1863 gene and RcsB protein was analyzed using DNA gel electrophoresis migration assay (electrophoretic mobility shift assay [EMSA]). The experiments revealed that acid adaptability and biofilm formation ability of STM1863 gene deletion strain were significantly weakened compared with the parental and complementary strains. Moreover, the adhesion and invasion ability of STM1863 deletion strain to mouse macrophages was significantly decreased, while the median lethal dose (LD50) increased by 2.148-fold compared with the parental strain. In addition, EMSA confirmed that RcsB protein could bind to the promoter sequence of STM1863 gene, suggesting that the expression of STM1863 gene might be modulated by RcsB. The present study demonstrated for the first time that STM1863, a member of the DUFs protein family, is involved in the modulation of environmental adaptation, biofilm formation, and virulence.

19.
Heliyon ; 10(7): e29094, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38623207

RESUMO

Purpose: Leptin resistance represents a primary pathological manifestation in obesity. Investigating potential treatments and associated mechanisms to restore leptin sensitivity is crucial for effective obesity management. This study aimed to explore the therapeutic potential of acupoints catgut embedding (ACE) in addressing obesity and its associated leptin resistance. Methods: A simple obesity model was established by subjecting C57 male mice to a high-fat diet (HFD) for 12 weeks, followed by ACE treatment administered to half of the obese mice for a duration of 4 weeks. The levels of leptin and its receptor-lepRb, were assessed using enzyme-linked immunosorbent assay (ELISA) and Western blot analysis, respectively. Autophagy progression markers were evaluated through quantitative polymerase chain reaction (qPCR) and Western blot analysis. Also, the liver autophagosomes were photographed using electron microscopy. The role of autophagy in regulating leptin resistance was elucidated using an autophagy suppression model. Results: Comparative analyses demonstrated that ACE treatment resulted in a significant reduction in body weight and blood lipid levels compared to the HFD group. Furthermore, serum leptin levels decreased, while liver lepRb expression increased following ACE treatment. The mRNA and protein expression levels of autophagy in liver were adjusted by ACE treatment. Interestingly, the beneficial effects of ACE were attenuated upon the administration of an autophagy inhibitor. Additionally, ACE treatment led to the activation of the AMPK-mTOR signaling pathway, a crucial regulator of autophagy. Conclusion: These findings suggest that ACE therapy holds promise for recovering leptin resistance by enhancing autophagy progression, mediated via the AMPK-mTOR signaling pathway in liver.

20.
Front Mol Biosci ; 11: 1364494, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38560519

RESUMO

The human multidrug transporter P-glycoprotein (P-gp) is physiologically essential and of key relevance to biomedicine. Recent structural studies have shed light on the mode of inhibition of the third-generation inhibitors for human P-gp, but the molecular mechanism by which these inhibitors enter the transmembrane sites remains poorly understood. In this study, we utilized all-atom molecular dynamics (MD) simulations to characterize human P-gp dynamics under a potent inhibitor, tariquidar, bound condition, as well as the atomic-level binding pathways in an explicit membrane/water environment. Extensive unbiased simulations show that human P-gp remains relatively stable in tariquidar-free and bound states, while exhibiting a high dynamic binding mode at either the drug-binding pocket or the regulatory site. Free energy estimations by partial nudged elastic band (PNEB) simulations and Molecular Mechanics Generalized Born Surface Area (MM/GBSA) method identify two energetically favorable binding pathways originating from the cytoplasmic gate with an extended tariquidar conformation. Interestingly, free tariquidar in the lipid membrane predominantly adopts extended conformations similar to those observed at the regulatory site. These results suggest that membrane lipids may preconfigure tariquidar into an active ligand conformation for efficient binding to the regulatory site. However, due to its conformational plasticity, tariquidar ultimately moves toward the drug-binding pocket in both pathways, explaining how it acts as a substrate at low concentrations. Our molecular findings propose a membrane-assisted mechanism for the access and binding of the third-generation inhibitors to the binding sites of human P-gp, and offer deeper insights into the molecule design of more potent inhibitors against P-gp-mediated drug resistance.

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