Functional implications of NHR-210 enrichment in C. elegans cephalic sheath glia: insights into metabolic and mitochondrial disruptions in Parkinson's disease models.

Glial cells constitute nearly half of the mammalian nervous system's cellular composition. The glia in C. elegans perform majority of tasks comparable to those conducted by their mammalian equivalents. The cephalic sheath (CEPsh) glia, which are known to be the counterparts of mammalian astrocytes, are enriched with two nuclear hormone receptors (NHRs)-NHR-210 and NHR-231. This unique enrichment makes the CEPsh glia and these NHRs intriguing subjects of study concerning neuronal health. We endeavored to assess the role of these NHRs in neurodegenerative diseases and related functional processes, using transgenic C. elegans expressing human alpha-synuclein. We employed RNAi-mediated silencing, followed by behavioural, functional, and metabolic profiling in relation to suppression of NHR-210 and 231. Our findings revealed that depleting nhr-210 changes dopamine-associated behaviour and mitochondrial function in human alpha synuclein-expressing strains NL5901 and UA44, through a putative target, pgp-9, a transmembrane transporter. Considering the alteration in mitochondrial function and the involvement of a transmembrane transporter, we performed metabolomics study via HR-MAS NMR spectroscopy. Remarkably, substantial modifications in ATP, betaine, lactate, and glycine levels were seen upon the absence of nhr-210. We also detected considerable changes in metabolic pathways such as phenylalanine, tyrosine, and tryptophan biosynthesis metabolism; glycine, serine, and threonine metabolism; as well as glyoxalate and dicarboxylate metabolism. In conclusion, the deficiency of the nuclear hormone receptor nhr-210 in alpha-synuclein expressing strain of C. elegans, results in altered mitochondrial function, coupled with alterations in vital metabolite levels. These findings underline the functional and physiological importance of nhr-210 enrichment in CEPsh glia.

Temperature Self-Limited Intelligent Thermo-chemotherapeutic Lipid Nanosystem for P-gp Reversal Time Window Matched Pulse Treatment of MDR Tumor.

Mild photothermal therapy (PTT) shows the potential for chemosensitization by tumor-localized P-glycoprotein (P-gp) modulation. However, conventional mild PTT struggles with real-time uniform temperature control, obscuring the temperature-performance relationship and resulting in thermal damage. Besides, the time-performance relationship and the underlying mechanism of mild PTT-mediated P-gp reversal remains elusive. Herein, we developed a temperature self-limiting lipid nanosystem (RFE@PD) that integrated a reversible organic heat generator (metal-phenolic complexes) and metal chelator (deferiprone, DFP) encapsulated phase change material. Upon NIR irradiation, RFE@PD released DFP for blocking ligand-metal charge transfer to self-limit temperature below 45 °C, and rapidly reduced P-gp within 3 h via Ubiquitin-proteasome degradation. Consequently, the DOX·HCl-loaded thermo-chemotherapeutic lipid nanosystem (RFE@PD-DOX) led to dramatically improved drug accumulation and 5-fold chemosensitization in MCF-7/ADR tumor models by synchronizing P-gp reversal and drug pulse liberation, achieving a tumor inhibition ratio of 82.42%. This lipid nanosystem integrated with "intrinsic temperature-control" and "temperature-responsive pulse release" casts new light on MDR tumor therapy.

Prebiotics counteract the morphological and functional changes secondary to chronic cisplatin exposition in the proximal colon of mice.

Cisplatin is an antimitotic drug able to cause acute and chronic gastrointestinal side effects. Acute side effects are attributable to mucositis while chronic ones are due to neuropathy. Cisplatin has also antibiotic properties inducing dysbiosis which enhances the inflammatory response, worsening local damage. Thus, a treatment aimed at protecting the microbiota could prevent or reduce the toxicity of chemotherapy. Furthermore, since a healthy microbiota enhances the effects of some chemotherapeutic drugs, prebiotics could also improve this drug effectiveness. We investigated whether chronic cisplatin administration determined morphological and functional alterations in mouse proximal colon and whether a diet enriched in prebiotics had protective effects. The results showed that cisplatin caused lack of weight gain, increase in kaolin intake, decrease in stool production and mucus secretion. Prebiotics prevented increases in kaolin intake, changes in stool production and mucus secretion, but had no effect on the lack of weight gain. Moreover, cisplatin determined a reduction in amplitude of spontaneous muscular contractions and of Connexin (Cx)43 expression in the interstitial cells of Cajal, changes that were partially prevented by prebiotics. In conclusion, the present study shows that daily administration of prebiotics, likely protecting the microbiota, prevents most of the colonic cisplatin-induced alterations.

Expression of GnT-III decreases chemoresistance via negatively regulating P-glycoprotein expression: Involvement of the TNFR2-NF-κB signaling pathway.

The phenomenon of multidrug resistance (MDR) is called chemoresistance with respect to the treatment of cancer, and it continues to be a major challenge. The role of N-glycosylation in chemoresistance, however, remains poorly understood. Here, we established a traditional model for adriamycin resistance in K562 cells, which are also known as K562/adriamycin-resistant (ADR) cells. Lectin blot, mass spectrometry, and RT-PCR analysis showed that the expression levels of N-acetylglucosaminyltransferase III (GnT-III) mRNA and its products, bisected N-glycans, are significantly decreased in K562/ADR cells, compared with the levels in parent K562 cells. By contrast, the expression levels of both P-glycoprotein (P-gp) and its intracellular key regulator, NF-κB signaling, are significantly increased in K562/ADR cells. These upregulations were sufficiently suppressed by the overexpression of GnT-III in K562/ADR cells. We found that the expression of GnT-III consistently decreased chemoresistance for doxorubicin and dasatinib, as well as activation of the NF-κB pathway by tumor necrosis factor (TNF) α, which binds to two structurally distinct glycoproteins, TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2), on the cell surface. Interestingly, our immunoprecipitation analysis revealed that only TNFR2, but not TNFR1, contains bisected N-glycans. The lack of GnT-III strongly induced TNFR2's autotrimerization without ligand stimulation, which was rescued by the overexpression of GnT-III in K562/ADR cells. Furthermore, the deficiency of TNFR2 suppressed P-gp expression while it increased GnT-III expression. Taken together, these results clearly show that GnT-III negatively regulates chemoresistance via the suppression of P-gp expression, which is regulated by the TNFR2-NF/κB signaling pathway.

Modulation of Multidrug Resistance Transporters by Food Components and Dietary Supplements: Implications for Cancer Therapy Efficacy and Safety.

The aim of this review is to explore how diet and dietary supplements influence the activity of key multidrug resistance (MDR) transporters-MRP2, BCRP, and P-gp. These transporters play a crucial role in drug efflux from cancer cells and significantly affect chemotherapy outcomes. This review focuses on how dietary phytochemicals, such as catechins and quercetin, impact the expression and function of these transporters. Both in vitro and in vivo experiments were examined to assess changes in drug bioavailability and intracellular drug accumulation. The findings show that certain dietary components-such as catechins, flavonoids, resveratrol, curcumin, terpenoids, sterols, and alkaloids-can either inhibit or induce MDR transporter activity, thus influencing the effectiveness of chemotherapy. These results highlight the importance of understanding diet-drug interactions in cancer therapy to improve treatment outcomes and reduce side effects. In conclusion, dietary modifications and supplements should be carefully considered in cancer treatment plans to optimize therapeutic efficacy.

Osmolyte-producing microbial biostimulants regulate the growth of Arachis hypogaea L. under drought stress.

Globally, drought stress poses a significant threat to crop productivity. Improving the drought tolerance of crops with microbial biostimulants is a sustainable strategy to meet a growing population's demands. This research aimed to elucidate microbial biostimulants' (Plant Growth Promoting Rhizobacteria) role in alleviating drought stress in oil-seed crops. In total, 15 bacterial isolates were selected for drought tolerance and screened for plant growth-promoting (PGP) attributes like phosphate solubilization and production of indole-3-acetic acid, siderophore, hydrogen cyanide, ammonia, and exopolysaccharide. This research describes two PGPR strains: Acinetobacter calcoaceticus AC06 and Bacillus amyloliquefaciens BA01. The present study demonstrated that these strains (AC06 and BA01) produced abundant osmolytes under osmotic stress, including proline (2.21 and 1.75 µg ml- 1), salicylic acid (18.59 and 14.21 µg ml- 1), trehalose (28.35 and 22.74 µg mg- 1 FW) and glycine betaine (11.35 and 7.74 mg g- 1) respectively. AC06 and BA01 strains were further evaluated for their multifunctional performance by inoculating in Arachis hypogaea L. (Groundnut) under mild and severe drought regimes (60 and 40% Field Capacity). Inoculation with microbial biostimulants displayed distinct osmotic-adjustment abilities of the groundnut, such as growth parameters, plant biomass, photosynthetic pigments, relative water content, proline, and soluble sugar in respective to control during drought. On the other hand, plant sensitivity indexes such as electrolyte leakage and malondialdehyde (MDA) contents were decreased as well as cooperatively conferred plant drought tolerance by induced alterations in stress indicators such as catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD). Thus, Acinetobacter sp. AC06 and Bacillus sp. BA01 can be considered as osmolyte producing microbial biostimulants to simultaneously induce osmotic tolerance and metabolic changes in groundnuts under drought stress.

Identification and characterization of endogenous biomarkers for hepatic vectorial transport (OATP1B3-P-gp) function using metabolomics with serum pharmacology.

The organic anion-transporting polypeptide 1B3 and P-glycoprotein (P-gp) provide efficient directional transport (OATP1B3-P-gp) from the blood to the bile that serves as a key determinant of hepatic disposition of the drug. Unfortunately, there is still a lack of effective means to evaluate the disposal ability mediated by transporters. The present study was designed to identify a suitable endogenous biomarker for the assessment of OATP1B3-P-gp function in the liver. We established stably transfected HEK293T-OATP1B3 and HEK293T-P-gp cell lines. Results showed that azelaic acid (AzA) was an endogenous substrate for OATP1B3 and P-gp using serum pharmacology combined with metabolomics. There is a good correlation between the serum concentration of AzA and probe drugs of rOATP1B3 and rP-gp when rats were treated with their inhibitors. Importantly, after 5-fluorouracil-induced rat liver injury, the relative mRNA level and expression of rOATP1B3 and rP-gp were markedly down-regulated in the liver, and the serum concentration of AzA was significantly increased. These observations suggest that AzA is an endogenous substrate of both OATP1B3 and P-gp, and may serve as a potential endogenous biomarker for the assessment of the function of OATP1B3-P-gp for the prediction of changes in the pharmacokinetics of drugs transported by OATP1B3-P-gp in liver disease states.

BI-2865, a pan-KRAS inhibitor, reverses the P-glycoprotein induced multidrug resistance in vitro and in vivo.

BACKGROUND: Multidrug resistance (MDR) limits successful cancer chemotherapy. P-glycoprotein (P-gp), BCRP and MRP1 are the key triggers of MDR. Unfortunately, no MDR modulator was approved by FDA to date. Here, we will investigate the effect of BI-2865, a pan-KRAS inhibitor, on reversing MDR induced by P-gp, BCRP and MRP1 in vitro and in vivo, and its reversal mechanisms will be explored. METHODS: The cytotoxicity of BI-2865 and its MDR removal effect in vitro were tested by MTT assays, and the corresponding reversal function in vivo was assessed through the P-gp mediated KBv200 xenografts in mice. BI-2865 induced alterations of drug discharge and reservation in cells were estimated by experiments of Flow cytometry with fluorescent doxorubicin, and the chemo-drug accumulation in xenografts' tumor were analyzed through LC-MS. Mechanisms of BI-2865 inhibiting P-gp substrate's efflux were analyzed through the vanadate-sensitive ATPase assay, [125I]-IAAP-photolabeling assay and computer molecular docking. The effects of BI-2865 on P-gp expression and KRAS-downstream signaling were detected via Western blotting, Flow cytometry and/or qRT-PCR. Subcellular localization of P-gp was visualized by Immunofluorescence. RESULTS: We found BI-2865 notably fortified response of P-gp-driven MDR cancer cells to the administration of chemo-drugs including paclitaxel, vincristine and doxorubicin, while such an effect was not observed in their parental sensitive cells and BCRP or MRP1-driven MDR cells. Importantly, the mice vivo combination study has verified that BI-2865 effectively improved the anti-tumor action of paclitaxel without toxic injury. In mechanism, BI-2865 prompted doxorubicin accumulating in carcinoma cells by directly blocking the efflux function of P-gp, which more specifically, was achieved by BI-2865 competitively binding to the drug-binding sites of P-gp. What's more, at the effective MDR reversal concentrations, BI-2865 neither varied the expression and location of P-gp nor reduced its downstream AKT or ERK1/2 signaling activity. CONCLUSIONS: This study uncovered a new application of BI-2865 as a MDR modulator, which might be used to effectively, safely and specifically improve chemotherapeutic efficacy in the clinical P-gp mediated MDR refractory cancers.

The placenta in fetal death: molecular evidence of dysregulation of inflammatory, proliferative, and fetal protective pathways.

BACKGROUND: It is estimated that over 2 million cases of fetal death occur worldwide every year, but, despite the high incidence, several basic and clinical characteristics of this disorder are still unclear. Placenta is suggested to play a central role in fetal death. Placenta produces hormones, cytokines and growth factors that modulate functions of the placental-maternal unit. Fetal death has been correlated with impaired secretion of some of these regulatory factors. OBJECTIVE: The aim of the present study was to evaluate, in placentas collected from fetal death, the gene expression of inflammatory, proliferative and protective factors. STUDY DESIGN: Cases of fetal death in singleton pregnancy were retrospectively selected, excluding pregnancies complicated by fetal anomalies, gestational diabetes, intrauterine growth restriction and moderate to severe maternal diseases. A group of placentas collected from healthy singleton term pregnancies were used as controls. Groups were compared regarding maternal and gestational age, fetal sex and birthweight. Placental messenger RNA expression of inflammatory (interleukin 6), proliferative (activin A, transforming growth factor ß1) and regulatory (vascular endothelial growth factor, vascular endothelial growth factor receptor 2, ATP-binding cassette transporters (ABC) ABCB1 and ABCG2, sphingosine 1-phosphate signaling pathway) markers was conducted using real-time polymerase chain reaction. Statistical analysis and graphical representation of the data were performed using the GraphPad Prism 5 software. For the statistical analysis, Student's t test was used, and P values<.05 were considered significant. RESULTS: Placental mRNA expression of interleukin 6 and vascular endothelial growth factor receptor 2 resulted significantly higher in the fetal death group compared to controls (P<.01), while activin A, ABCB1, and ABCG2 expression resulted significantly lower (P<.01). A significant alteration in the sphingosine 1-phosphate signaling pathway was found in the fetal death group, with an increased expression of the specific receptor isoforms sphingosine 1-phosphate receptor 1, 3, and 4 (sphingosine 1-phosphate1, sphingosine 1-phosphate3, sphingosine 1-phosphate4) and of sphingosine kinase 2, 1 of the enzyme isoforms responsible for sphingosine 1-phosphate synthesis (P<.01). CONCLUSION: The present study confirmed a significantly increased expression of placental interleukin 6 and vascular endothelial growth factor receptor 2 mRNA, and for the first time showed an increased expression of sphingosine 1-phosphate receptors and sphingosine kinase 2 as well as a decreased expression of activin A and of selected ATP-binding cassette transporters, suggesting that multiple inflammatory and protective factors are deranged in placenta of fetal death.

Immunohistochemical staining with CD117 and PGP9.5 of excised vestibular tissue from patients with neuroproliferative vestibulodynia.

BACKGROUND: Neuroproliferative vestibulodynia (NPV), a provoked genital pain characterized by severe allodynia and hyperalgesia, is confirmed in excised vestibular tissue by immunohistochemical staining (>8 CD117-positive immunostained cells/100× microscopic field) rather than by hematoxylin and eosin staining. AIM: In this study we sought to assess immunostaining of tissue samples obtained during vestibulectomy surgery and to correlate results with patient outcomes. METHODS: Patients (n = 65) meeting criteria for NPV who underwent vestibulectomy during the period from June 2019 through December 2022 formed the study cohort. We performed assessment of pathology of vestibular tissues by use of immunohistochemical staining, including quantitation of mast cells by CD117 (mast cell marker) and nerve fibers by protein gene product (PGP) 9.5 (neuronal marker). We analyzed 725 photomicrographs of immunostained tissue sections (100× and 200×) by manual counting and computer-assisted histometry and correlated these data to clinical assessments. OUTCOMES: Outcomes included density of CD117 and PGP9.5 immunostaining in the 1:00-11:00 o'clock and 12:00 o'clock vestibular regions, and patient-reported outcomes assessing sexual function, pain, distress, and symptom improvement. RESULTS: All 65 NPV patients (median age 26 years), 45 with lifelong and 20 with acquired NPV, had severe pain documented by PROs and vulvoscopy and had >8 CD117-immunopositive cells/100× microscopic field. Median cell count values were similar in the 1:00-11:00 o'clock and 12:00 vestibular regions (28.5 and 29.5/100× field, respectively). Likewise, the marker) and nerve fibers by protein gene product (PGP) 9.5 (neuronal marker). We analyzed 725 photomicrographs of immunostained tissue sections (100× and 200×) by manual counting and computer-assisted histometry and correlated these data to clinical assessments. OUTCOMES: Outcomes included density of CD117 and PGP9.5 immunostaining in the 1:00-11:00 o'clock and 12:00 o'clock vestibular regions, and patient-reported outcomes assessing sexual function, pain, distress, and symptom improvement. RESULTS: All 65 NPV patients (median age 26 years), 45 with lifelong and 20 with acquired NPV, had severe pain documented by PROs and vulvoscopy and had >8 CD117-immunopositive cells/100× microscopic field. Median cell count values were similar in the 1:00-11:00 o'clock and 12:00 vestibular regions (28.5 and 29.5/100× field, respectively). Likewise, the median area of CD117 immunostaining was similar in both regions (0.69% and 0.73%). The median area of PGP9.5 immunostaining was 0.47% and 0.31% in these same regions. Pain scores determined with cotton-tipped swab testing were nominally higher in lifelong vs acquired NPV patients, reaching statistical significance in the 1:00-11:00 o'clock region (P < .001). The median score for the McGill Pain Questionnaire affective subscale dimension was also significantly higher in lifelong vs acquired NPV patients (P = .011). No correlations were observed between hematoxylin and eosin results and density of mast cells or neuronal markers. Of note, 63% of the patient cohort reported having additional conditions associated with aberrant mast cell activity. CLINICAL IMPLICATIONS: The pathology of NPV is primarily localized to the vestibular epithelial basement membrane and subepithelial stroma with no visible vulvoscopic findings, making clinical diagnosis challenging. STRENGTHS AND LIMITATIONS: Strengths of this study include the large number of tissues examined with what is to our knowledge the first-ever assessment of the 12:00 vestibule. Major limitations are specimens from a single timepoint within the disease state and lack of control tissues. CONCLUSIONS: Performing immunohistochemical staining of excised vestibular tissue with CD117 and PGP9.5 led to histometric confirmation of NPV, indications that NPV is a field disease involving all vestibular regions, validation for patients whose pain had been ignored and who had experienced negative psychosocial impact, and appreciation that such staining can advance knowledge.

Effect of Apolipoprotein E isoforms on the Abundance and Function of P-glycoprotein in Human Brain Microvascular Endothelial Cells.

BACKGROUND: Individuals with Alzheimer's disease (AD) often require many medications; however, these medications are dosed using regimens recommended for individuals without AD. This is despite reduced abundance and function of P-glycoprotein (P-gp) at the blood-brain barrier (BBB) in AD, which can impact brain exposure of drugs. The fundamental mechanisms leading to reduced P-gp abundance in sporadic AD remain unknown; however, it is known that the apolipoprotein E (apoE) gene has the strongest genetic link to sporadic AD development, and apoE isoforms can differentially alter BBB function. The aim of this study was to assess if apoE affects P-gp abundance and function in an isoform-dependent manner using a human cerebral microvascular endothelial cell (hCMEC/D3) model. METHODS: This study assessed the impact of apoE isoforms on P-gp abundance (by western blot) and function (by rhodamine 123 (R123) uptake) in hCMEC/D3 cells. Cells were exposed to recombinant apoE3 and apoE4 at 2 - 10 µg/mL over 24 - 72 hours. hCMEC/D3 cells were also exposed for 72 hours to astrocyte-conditioned media (ACM) from astrocytes expressing humanised apoE isoforms. RESULTS: P-gp abundance in hCMEC/D3 cells was not altered by recombinant apoE4 relative to recombinant apoE3, nor did ACM containing human apoE isoforms alter P-gp abundance. R123 accumulation in hCMEC/D3 cells was also unchanged with recombinant apoE isoform treatments, suggesting no change to P-gp function, despite both abundance and function being altered by positive controls SR12813 (5 µM) and PSC 833 (5 µM), respectively. CONCLUSIONS: Different apoE isoforms have no direct influence on P-gp abundance or function within this model, and further in vivo studies would be required to address whether P-gp abundance or function are reduced in sporadic AD in an apoE isoform-specific manner.

Recent developments of P-glycoprotein inhibitors and its structure-activity relationship (SAR) studies.

P-glycoprotein (P-gp) over-expression is a key factor in multi-drug resistance (MDR), which is a major factor in the failure of cancer treatment. P-gp inhibitors have been demonstrated to have powerful pharmacological properties and may be used as a therapeutic approach to overcome the MDR in cancer cells. Combining clinical investigations with biochemical and computational research may potentially lead to a clearer understanding of the pharmacological properties and the mechanisms of action of these P-gp inhibitors. The task of turning these discoveries into effective therapeutic candidates for a variety of malignancies, including resistant and metastatic kinds, falls on medicinal chemists. A variety of P-gp inhibitors with great potency, high selectivity, and minimal toxicity have been identified in recent years. The latest advances in drug design, characterization, structure-activity relationship (SAR) research, and modes of action of newly synthesized, powerful small molecules P-gp inhibitors over the previous ten years are highlighted in this review. P-gp transporter over-expression has been linked to MDR, therefore the development of P-gp inhibitors will expand our understanding of the processes and functions of P-gp-mediated drug efflux, which will be helpful for drug discovery and clinical cancer therapies.

Design, synthesis, and ex vivo anti-drug resistant cervical cancer activity of novel molecularly targeted chalcone derivatives.

Chemotherapy toxicity and tumor multidrug resistance remain the main reasons for clinical treatment failure in cervical cancer. In this study, 79 novel chalcone derivatives were designed and synthesized using the principle of active substructure splicing with the parent nucleus of licorice chalcone as the lead compound and VEGFR-2 and P-gp as the target of action and their potentials for anticervical cancer activity were preliminarily evaluated. The results showed that the IC50 values of candidate compound B20 against HeLa and HeLa/DDP cells were 3.66 ± 0.10 and 4.35 ± 0.21 µΜ, respectively, with a resistance index (RI) of 1.18, which was significantly higher than that of the positive drug cisplatin (IC50:13.60 ± 1.63, 100.03 ± 7.94 µΜ, RI:7.36). In addition, B20 showed significant inhibitory activity against VEGFR-2 kinase and P-gp-mediated rhodamine 123 efflux, as well as the ability to inhibit the phosphorylation of VEGFR-2 and downstream PI3K/AKT signaling pathway proteins, inducing apoptosis, blocking cells in the S-phase, and inhibiting invasive migration and tubule generation by HUVEC cells. Acceptable safety was demonstrated in acute toxicity tests when B20 was at 200 mg/kg. In the nude mouse HeLa/DDP cell xenograft tumor model, the inhibition rate of transplanted tumors was 39.2 % and 79.2 % when B20 was at 10 and 20 mg/kg, respectively. These results suggest that B20 is a potent VEGFR-2 and P-gp inhibitor with active potential for treating cisplatin-resistant cervical cancer.

A novel FAK-degrading PROTAC molecule exhibited both anti-tumor activities and efficient MDR reversal effects.

FAK (focal adhesion kinase) is widely involved in cancer growth and drug resistance development. Thus, FAK inhibition has emerged as an effective strategy for tumor treatment both as a monotherapy or in combination with other treatments. But the current FAK inhibitors mainly concentrate on its kinase activity, overlooking the potential significance of FAK scaffold proteins. In this study we employed the PROTAC technology, and designed a novel PROTAC molecule F2 targeting FAK based on the FAK inhibitor IN10018. F2 exhibited potent inhibitory activities against 4T1, MDA-MB-231, MDA-MB-468 and MDA-MB-435 cells with IC50 values of 0.73, 1.09, 5.84 and 3.05 µM, respectively. On the other hand, F2 also remarkably reversed the multidrug resistance (MDR) in HCT8/T, A549/T and MCF-7/ADR cells. Both the effects of F2 were stronger than the FAK inhibitor IN10018. To our knowledge, F2 was the first reported FAK-targeted PROTAC molecule exhibiting reversing effects on chemotherapeutic drug resistance, and its highest reversal fold could reach 158 times. The anti-tumor and MDR-reversing effects of F2 might be based on its inhibition on AKT (protein kinase B, PKB) and ERK (extracellular signal-regulated kinase) signaling pathways, as well as its impact on EMT (epithelial-mesenchymal transition). Furthermore, we found that F2 could reduce the protein level of P-gp in HCT8/T cells, thereby contributing to reverse drug resistance from another perspective. Our results will boost confidence in future research focusing on targeting FAK and encourage further investigation of PROTAC with potent in vivo effects.

Lack of CYP3A4 protein induction despite mRNA induction in primary hepatocytes exposed to rifabutin as a possible explanation for its low interaction risk in vivo.

Rifampicin is a strong inducer of cytochrome P450 (CYP3A4) and P-glycoprotein (P-gp/ABCB1), leading to profound drug-drug interactions. In contrast, the chemically related rifabutin does not show such pronounced induction properties in vivo. The aim of our study was to conduct a comprehensive analysis of the different induction potentials of rifampicin and rifabutin in primary human hepatocytes and to analyze the mechanism of potential differences. Therefore, we evaluated CYP3A4/ABCB1 mRNA expression (polymerase chain reaction), CYP3A4/P-gp protein expression (immunoaffinity-liquid chromatography-mass spectrometry, IA-LC-MS/MS), CYP3A4 activity (testosterone hydroxylation), and considered intracellular drug uptake after treatment with increasing rifamycin concentrations (0.01-10 µM). Furthermore, rifamycin effects on the protein levels of CYP2C8, CYP2C9, and CYP2C19 were analyzed (IA-LC-MS/MS). Mechanistic analysis included the evaluation of possible suicide CYP3A4 inhibition (IC50 shift assay) and drug impact on translational efficiency (cell-free luminescence assays). Rifabutin accumulated 6- to 15-fold higher in hepatocytes than rifampicin, but induced CYP3A4 mRNA comparably to rifampicin (e. g. rifampicin 61-fold vs. rifabutin 44-fold, 72 h). While rifampicin for example enhanced protein (10 µM: 21-fold) and activity levels considerably (53-fold), rifabutin only slightly increased CYP3A4 protein expression (10 µM: 3.3-fold) or activity (11-fold) compared to rifampicin after 72 h. Both rifamycins similarly influenced expression of other eliminating proteins. A potential CYP3A4 suicide inhibition by a specific rifabutin metabolite or disruption of ribosome function were excluded experimentally. In conclusion, the lack of protein enhancement, could explain rifabutin's weaker induction-related drug-drug interaction risk in vivo.

Assessment of drug-drug interaction of dapagliflozin with LCZ696 based on an LC-MS/MS method.

The co-administration of dapagliflozin (DPF) and sacubitril/valsartan (LCZ696) has emerged as a promising therapeutic approach for managing heart failure. Given that DPF and LCZ696 are substrates for P-glycoprotein, there is a plausible potential for drug-drug interactions when administered concomitantly. To investigate the pharmacokinetic changes when these drugs are co-administered, we have established and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method capable of simultaneously detecting DPF, LBQ657 (the active metabolite of sacubitril) and valsartan in rat plasma. This method has demonstrated selectivity, sensitivity, and accuracy. Drug-drug interactions were examined by the LC-MS/MS method. The mechanisms were investigated using everted intestinal sac models and Caco-2 cells. The results showed that DPF significantly increased the area under the curve (AUC(0-t)) (3,563.3 ± 651.7 vs. 7,146.5 ± 1,714.9 h µg/L) of LBQ657 (the active metabolite of sacubitril) and the AUC(0-t) (24,022.4 ± 6,774.3 vs. 55,728.3 ± 32,446.3 h µg/L) of valsartan after oral co-administration. Dapagliflozin significantly increased the amount of LBQ657 and valsartan in intestinal sacs by 1- and 1.25-fold at 2.25 h. Caco-2 cell uptake studies confirmed that P-glycoprotein is the transporter involved in this interaction. This finding enhances the understanding of drug-drug interactions in the treatment of heart failure and provides a guidence for clinical therapy.

Analysis of OCT4 and PGP9.5 gene expression in prenatal and postnatal buffalo (Bubalus bubalis) testes.

This study aimed to investigate and characterize the spermatogonial stem cells (SSCs) in buffaloes at different stages of development, including prenatal, neonatal, prepubertal, and adult testes. We sought a comprehensive understanding of these cells through a combination of histological, immunohistochemical, and ultrastructural analyses. Specifically, we examined changes in the expression of two potential SSC markers, OCT4 and PGP9.5, using immunohistochemistry. Additionally, we conducted a real-time quantitative polymerase chain reaction (RT-qPCR) to assess the relative gene expression of OCT4 and PGP9.5. The relative expression of the OCT4 gene was down-regulated in the adult testes compared to its expression during prepubertal and neonatal life. The relative expression of the PGP9.5 gene was up-regulated in the neonatal testes and down-regulated in the prepubertal and adult testes. The spermatogonia were round, oval-to-ellipsoidal cells lying over the basement membrane (BM) with a round-to-oval nucleus. Based on the immunoexpression of the putative SSC markers, OCT4 and PGP9.5, we concluded that the proportion of stem cells was highest during the neonatal stage, followed by the prepubertal and prenatal stages. This finding sheds light on the dynamics of spermatogonial stem cells in buffalo testes at different developmental stages, providing valuable insights into these cells' regulation and potential applications.

P-glycoprotein-mediated herb-drug interaction evaluation between Tenacissoside G and paclitaxel.

P-glycoprotein (P-gp)-mediated herb-drug interactions (HDIs) may impact drug efficacy and safety. Tenacissoside G (Tsd-G), a major active component of Marsdenia tenacissima, exhibits anticancer activity. To analyze the effect of Tsd-G on the pharmacokinetics of paclitaxel (PTX), researchers selected 30 Sprague-Dawley (SD) rats, randomized into a solvent control group, a verapamil positive control group, and 20, 40, and 60 mg/kg Tsd-G groups. After seven consecutive days of intraperitoneal injection of verapamil or Tsd-G, a single dose of 6 mg/kg PTX was injected intravenously. Plasma samples were collected at different time points, and proteins were precipitated using a methanol-acetonitrile solution. An ultrahigh-performance liquid chromatography-tandem mass spectrometry method was developed, with docetaxel as an internal standard, and quantified using positive ion multiple reaction monitoring (MRM) mode. This analytical method's specificity, accuracy, precision, recovery, matrix effect, and sample stability meet the requirements for biological sample determination. After Tsd-G administration in rats, the mean residence time of PTX was significantly prolonged. And Tsd-G can stably bind to P-gp by forming hydrogen bonds and inhibiting the expression of P-gp in rat liver. Although the metabolites of PTX were not detected in this study, the above results still indicate the existence of HDIs between Tsd-G and PTX, and P-gp may be the main target to mediate HDIs.

Characterization of the Synergistic Effect of Fungal Isolates in Suppressing Ganoderma boninense and Enhancing Oil Palm Growth.

The globally vital oil palm, a major oil producer, confronts productivity challenges due to Ganoderma boninense (Gb), causing output decline. Chemical control efforts have proven ineffective, prompting exploration of microbial-based biocontrol. While single fungal biocontrol research exists, the impact of employing multiple biocontrols concurrently to combat Ganoderma and enhance oil palm growth remains uncharted. This study examined four soil-derived fungal isolates for their ability to antagonize Gb PER71 in vitro. Molecular identification categorized them as Talaromyces spp. and Penicillium sp. Moreover, all isolates were revealed to have at least three plant growth-promoting (PGP) traits and were shown to have phosphoric hydrolase, ester hydrolase, peptide hydrolase, and glycosidase activities which are essential for plant growth. Furthermore, the synergistic evaluation of fungal isolates was tested against Gb PER71. One out of six combinations of fungal isolates showed a synergistic effect in vitro, and two showed a synergistic effect in planta. The application of single and combined fungal isolates tested in planta also suppressed Gb PER71 and enhanced oil palm growth compared to control groups. The findings indicate the promising potential of these isolates as biocontrol agents (BCAs) and bioformulations against Gb in oil palm cultivation.

Dual Inhibitors of P-gp and Carbonic Anhydrase XII (hCA XII) against Tumor Multidrug Resistance with Piperazine Scaffold.

A new series of piperazine derivatives were synthesized and studied with the aim of obtaining dual inhibitors of P-glycoprotein (P-gp) and carbonic anhydrase XII (hCA XII) to synergistically overcome the P-gp-mediated multidrug resistance (MDR) in cancer cells expressing the two proteins, P-gp and hCA XII. Indeed, these hybrid compounds contain both P-gp and hCA XII binding groups on the two nitrogen atoms of the heterocyclic ring. All compounds showed good inhibitory activity on each protein (P-gp and hCA XII) studied individually, and many of them showed a synergistic effect in the resistant HT29/DOX and A549/DOX cell lines which overexpress both the target proteins. In particular, compound 33 displayed the best activity by enhancing the cytotoxicity and intracellular accumulation of doxorubicin in HT29/DOX and A549/DOX cells, thus resulting as promising P-gp-mediated MDR reverser with a synergistic mechanism. Furthermore, compounds 13, 27 and 32 induced collateral sensitivity (CS) in MDR cells, as they were more cytotoxic in resistant cells than in the sensitive ones; their CS mechanisms were extensively investigated.