Measurement of Rhodamine 123 in Three-Dimensional Organoids: A Novel Model for P-Glycoprotein Inhibitor Screening

P-gp inhibition and enhanced oral bioavailability of amikacin Sulfate: A novel approach using Thiolated Chito-PEGylated Lipidic Hybrids

This study aimed to develop oral lipidic hybrids of amikacin sulfate (AMK), incorporating thiolated chitosan as a P-glycoprotein (P-gp) inhibitor to enhance intestinal absorptivity and bioavailability. Three formulations were designed: PEGylated Liposomes, Chitosan-functionalized PEGylated (Chito-PEGylated) Lipidic Hybrids, and Thiolated Chito-PEGylated Lipidic Hybrids. The physical characteristics of nanovesicles were assessed. Ex-vivo permeation and confocal laser scanning microscopy (CLSM) studies were conducted to evaluate the formulations' potential to enhance AMK intestinal permeability. In-vivo pharmacokinetic studies in rats and histological/biochemical investigations assessed the safety profile and oral bioavailability. The AMK-loaded Thiolated Chito-PEGylated Lipidic Hybrids exhibited favorable physical characteristics, higher ex-vivo permeation parameters, and verified P-gp inhibition via CLSM. They demonstrated heightened oral bioavailability (68.62% absolute bioavailability) and a sufficient safety profile. Relative bioavailability was significantly higher (1556.3% and 448.79%) compared to PEGylated Liposomes and Chito-PEGylated Lipidic Hybrids, respectively, indicating remarkable oral AMK delivery with fewer doses, reduced side effects, and enhanced patient compliance.

Jianpi Jiedu decoction reverses 5-fluorouracil resistance in colorectal cancer by suppressing the xCT/GSH/GPX4 axis to induce ferroptosis

Introduction

Innate and acquired chemoresistance in colorectal cancer (CRC) often results in 5-fluorouracil (5-FU) treatment failure. This study aimed to investigate the potential of Jianpi Jiedu (JPJD) decoction to reverse 5-FU resistance in CRC and clarify its potential mechanism of action.

Methods

The CCK-8 assay was employed to assess cell activity. Flow cytometry was employed to assess various parameters including cell apoptosis, cell cycle distribution, P-glycoprotein (P-gp) activity, reactive oxygen species levels, and lipid peroxidation. Metabolomics analysis was conducted to identify differentially expressed metabolites. Western blotting was utilized for protein expression analysis.

Results

In this study, we demonstrated that the combined JPJD and 5-FU treatment reversed 5-FU resistance in HCT8/5-FU cells, inducing cell apoptosis, causing G2/M-phase cell cycle arrest, and reducing P-gp protein expression and activity. Metabolomics analysis revealed ferroptosis as a key pathway in the development of 5-FU resistance. Furthermore, the combination treatment reversed drug resistance primarily by impacting ferroptosis and triggering critical ferroptosis events through the suppression of the cystine/glutamate transporter (xCT)/glutathione (GSH)/glutathione peroxidase (GPX4) axis.

Conclusion

JPJD decoction primarily suppressed the xCT/GSH/GPX4 axis to trigger ferroptosis, thereby effectively reversing 5-FU resistance in colorectal cancer (CRC).

Development of Scaffold-Free Three-Dimensional Cholangiocyte Organoids to Study the Progression of Primary Sclerosing Cholangitis

Organoids are novel in vitro models to study intercellular cross talk between the different types of cells in disease pathophysiology. To better understand the underlying mechanisms driving the progression of primary sclerosing cholangitis (PSC), scaffold-free multicellular three-dimensional cholangiocyte organoids (3D-CHOs) were developed using primary liver cells derived from normal subjects and patients with PSC. Human liver samples from healthy donors and patients with PSC were used to isolate primary cholangiocytes [epithelial cell adhesion molecule (EpCam)+/ cytokeratin-19+], liver endothelial cells (CD31+), and hepatic stellate cells (HSCs; CD31-/CD68-/desmin+/vitamin A+). 3D-CHOs were formed using cholangiocytes, HSCs, and liver endothelial cells, and kept viable for up to 1 month. Isolated primary cell lines and 3D-CHOs were further characterized by immunofluorescence, quantitative RT-PCR, and transmission electron microscopy. Transcription profiles for cholangiocytes (SOX9, CFTR, EpCAM, AE, SCT, and SCTR), fibrosis (ACTA2, COL1A1, DESMIN, and TGFβ1), angiogenesis (PECAM, VEGF, CDH5, and vWF), and inflammation (IL-6 and TNF-α) confirmed PSC phenotypes of 3D-CHOs. Because cholangiocytes develop a neuroendocrine phenotype and express neuromodulators, confocal immunofluorescence was used to demonstrate localization of the neurokinin-1 receptor within cytokeratin-19+ cholangiocytes and desmin+ HSCs. Moreover, 3D-CHOs from patients with PSC confirmed PSC phenotypes with up-regulated neurokinin-1 receptor, tachykinin precursor 1, and down-regulated membrane metalloendopeptidase. Scaffold-free multicellular 3D-CHOs showed superiority as an in vitro model in mimicking PSC in vivo phenotypes compared with two-dimensional cell culture, which can be used in PSC disease-related research.

Terconazole, an Azole Antifungal Drug, Increases Cytotoxicity in Antimitotic Drug-Treated Resistant Cancer Cells with Substrate-Specific P-gp Inhibitory Activity

Azole antifungal drugs have been shown to enhance the cytotoxicity of antimitotic drugs in P-glycoprotein (P-gp)-overexpressing-resistant cancer cells. Herein, we examined two azole antifungal drugs, terconazole (TCZ) and butoconazole (BTZ), previously unexplored in resistant cancers. We found that both TCZ and BTZ increased cytotoxicity in vincristine (VIC)-treated P-gp-overexpressing drug-resistant KBV20C cancer cells. Following detailed analysis, low-dose VIC + TCZ exerted higher cytotoxicity than co-treatment with VIC + BTZ. Furthermore, we found that VIC + TCZ could increase apoptosis and induce G2 arrest. Additionally, low-dose TCZ could be combined with various antimitotic drugs to increase their cytotoxicity in P-gp-overexpressing antimitotic drug-resistant cancer cells. Moreover, TCZ exhibited P-gp inhibitory activity, suggesting that the inhibitory activity of P-gp plays a role in sensitization afforded by VIC + TCZ co-treatment. We also evaluated the cytotoxicity of 12 azole antifungal drugs at low doses in drug-resistant cancer cells. VIC + TCZ, VIC + itraconazole, and VIC + posaconazole exhibited the strongest cytotoxicity in P-gp-overexpressing KBV20C and MCF-7/ADR-resistant cancer cells. These drugs exerted robust P-gp inhibitory activity, accompanied by calcein-AM substrate efflux. Given that azole antifungal drugs have long been used in clinics, our results, which reposition azole antifungal drugs for treating P-gp-overexpressing-resistant cancer, could be employed to treat patients with drug-resistant cancer rapidly.

Saponins from Panax notoginseng ameliorate steroid resistance in lupus nephritis through regulating lymphocyte-derived exosomes in mice

Lupus nephritis (LN) is the most common and severe type of organ damage and an important primary disease in end-stage renal failure in patients with systemic lupus erythematosus (SLE). Clinical guidelines recommend steroid treatment, but steroid resistance has become a major factor leading to treatment failure and affecting prognosis. Our previous study demonstrated that Saponins from Panax Notoginseng (Panax ginseng saponins, PNS) could reverse steroid resistance of lymphocytes by downregulating P-glycoprotein (P-gp) expression and provide renal protection in LN mice, but the mechanism by which lymphocytes transmit these related messages to renal lamina propria cells is not clear. Therefore, we further elucidated this mechanism through holistic experiments. In this study, low-dose methylprednisolone (0.8 mg/kg/day, MP) was used to induce a steroid-resistant lupus nephritis (SR-LN) mouse model in weeks one to four, and a therapeutic steroid dosage (MP 12 mg/kg/day) or a combined PNS (PNS 100 mg/kg/day) treatment was administered from week five to eight. Lymphocyte-derived exosomes (Lyme-Exos) were isolated from the spleens of mice and injected into untreated homozygous LN mice for 14 days via the tail vein. At the end of the experiment, the efficacy and mechanism of action of different groups of Lyme-Exos on LN mice were observed. The results revealed that exogenously injected Lyme-Exos were effectively taken up by the kidney and affected the progression of kidney disease. Steroid-resistant lymphocyte-derived exosomes intervented with PNS significantly downregulated the levels of silent information regulator-related enzyme 1 (Sirt1), multidrug resistance gene 1 (MDR1), and P-gp in the renal cortex and glomerular endothelial cells (GECs); reduced serum autoantibody [antinuclear antibody (ANA) and anti-double-stranded DNA (dsDNA)] levels and inflammatory markers (WBC, PCR, and PCT); improved renal function; and attenuated urinary microalbumin excretion. Additionally, renal histopathological damage (HE staining) and fibrosis (Masson staining) were improved, and immune complex (IgG) deposition and membrane attack complex (C5b-9) production were significantly reduced; the gene levels of inflammatory factors (INF-γ, MCP-1, IL-8, IL-17, vWF, VCAM-1, IL-1β, IL-6, PTX3) in the renal cortex were downregulated. Taken together, this study showed that PNS may alleviate steroid resistance in GEC by interfering with steroid-resistant Lyme-Exos to ameliorate LN progression, which will likely provide insights into developing a new LN treatment.

Low-Dose Rifabutin Increases Cytotoxicity in Antimitotic-Drug-Treated Resistant Cancer Cells by Exhibiting Strong P-gp-Inhibitory Activity

The cytotoxicity of various antibiotics at low doses in drug-resistant cancer cells was evaluated. Low doses of rifabutin were found to markedly increase the cytotoxicity of various antimitotic drugs, such as vincristine (VIC), to P-glycoprotein (P-gp)-overexpressing antimitotic-drug-resistant KBV20C cells. Rifabutin was also found to exert high levels of P-gp-inhibitory activity at 4 and 24 h posttreatment, suggesting that the cytotoxicity of VIC + rifabutin was mainly due to the direct binding of rifabutin to P-gp and the reduction of VIC efflux by P-gp. The combination of VIC + rifabutin also increased early apoptosis, G2 arrest, and the DNA damaging marker, pH2AX protein. Interestingly, only the combination of VIC + rifabutin induced remarkable levels of cytotoxicity in resistant KBV20C cells, whereas other combinations (VIC + rifampin, VIC + rifapentine, and VIC + rifaximin) induced less cytotoxicity. Such finding suggests that rifabutin specifically increases the cytotoxicity of VIC in KBV20C cells, independent of the toxic effect of the ansamycin antibiotic. Only rifabutin had high P-gp-inhibitory activity, which suggests that its high P-gp-inhibitory activity led to the increased cytotoxicity of VIC + rifabutin. As rifabutin has long been used in the clinic, repositioning this drug for P-gp-overexpressing resistant cancer could increase the availability of treatments for patients with drug-resistant cancer.

Current Trends and Research Topics Regarding Intestinal Organoids: An Overview Based on Bibliometrics

Currently, research on intestinal diseases is mainly based on animal models and cell lines in monolayers. However, these models have drawbacks that limit scientific advances in this field. Three-dimensional (3D) culture systems named organoids are emerging as a reliable research tool for recapitulating the human intestinal epithelium and represent a unique platform for patient-specific drug testing. Intestinal organoids (IOs) are crypt–villus structures that can be derived from adult intestinal stem cells (ISCs), embryonic stem cells (ESCs), or induced pluripotent stem cells (iPSCs) and have the potential to serve as a platform for individualized medicine and research. However, this emerging field has not been bibliometric summarized to date. Here, we performed a bibliometric analysis of the Web of Science Core Collection (WoSCC) database to evaluate 5,379 publications concerning the use of organoids; the studies were divided into four clusters associated with the current situation and future directions for the application of IOs. Based on the results of our bibliometric analysis of IO applications, we systematically summarized the latest advances and analyzed the limitations and prospects.

3D organoids derived from the small intestine: An emerging tool for drug transport research

Small intestine in vitro models play a crucial role in drug transport research. Although conventional 2D cell culture models, such as Caco-2 monolayer, possess many advantages, they should be interpreted with caution because they have relatively poor physiologically reproducible phenotypes and functions. With the development of 3D culture technology, pluripotent stem cells (PSCs) and adult somatic stem cells (ASCs) show remarkable self-organization characteristics, which leads to the development of intestinal organoids. Based on previous studies, this paper reviews the application of intestinal 3D organoids in drug transport mediated by P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance protein 2 (MRP2). The advantages and limitations of this model are also discussed. Although there are still many challenges, intestinal 3D organoid model has the potential to be an excellent tool for drug transport research.

Generation of Intestinal Organoids Suitable for Pharmacokinetic Studies from Human Induced Pluripotent Stem Cells

Intestinal organoids morphologically resemble intestinal tissues and are expected to be used in both regenerative medicine and drug development studies, including pharmacokinetic studies. However, the pharmacokinetic properties of these organoids remain poorly characterized. In this study, we aimed to generate pharmacokinetically functional intestinal organoids from human induced pluripotent stem (iPS) cells. Human iPS cells were induced to differentiate into the midgut and then seeded on EZSPHERE plates (AGC Techno Glass Inc., Shizuoka, Japan) to generate uniform spheroids, and the floating spheroids were subsequently differentiated into intestinal organoids using small-molecule compounds. Exposure to the small-molecule compounds potently increased the expression of intestinal markers and pharmacokinetic-related genes in the organoids, and the organoids also included various intestinal cells such as enterocytes, intestinal stem cells, goblet cells, enteroendocrine cells, Paneth cells, smooth muscle cells, and fibroblasts. Moreover, microvilli and tight junctions were observed in the organoids. Furthermore, we detected not only the expression of drug transporters but also efflux transport activity through ABCB1/MDR1 and the induction of the drug-metabolizing enzyme CYP3A4 by ligands of nuclear receptors. Our results demonstrated the successful generation of pharmacokinetically functional intestinal organoids from human iPS cells. Thus, these intestinal organoids could be used as a pharmacokinetic evaluation system in drug development studies.

A novel biosensor based on intestinal 3D organoids for detecting the function of BCRP

Breast cancer resistance protein (BCRP), a key drug efflux transporter, significantly affects the therapeutic efficacy of many drugs. Thus, screening specific BCRP inhibitors and distinguishing between substrates and non-substrates of BCRP are valuable in drug discovery and development. This study presents a novel BCRP biosensor based on intestinal 3D organoids for rapid and sensitive detection of BCRP function. First, the crypts were isolated from mouse small intestine, and cultured in advanced DMEM/F12 medium to develop intestinal 3D organoids. Second, immunohistochemical studies demonstrated that BCRP protein in the organoids presented a similar expression and physiologic position to the small intestinal epithelium. Finally, the cultured organoids were treated in BCRP fluorogenic probe substrate Hoechst 33342 with or without BCRP inhibitor Ko143 and YHO-13177. The fluorescence intensity of Hoechst 33342 released from inner of the organoids was detected by microplate reader and the concentrations were calculated. Ko143 and YHO-13177 significantly inhibited the BCRP-mediated Hoechst 33342 transport in the 3D organoids. Consequently, a rapid and efficient biosensor has been successfully established to study BCRP, especially screening BCRP inhibitors in a high-throughput way.

Comprehensive assessment of Cucurbitacin E related hepatotoxicity and drug-drug interactions involving CYP3A and P-glycoprotein

BACKGROUND

Cucurbitacin E (CuE), a tetracyclic triterpenoid isolated from Cucurbitaceae, possesses many pharmacological activities especially anti-cancer.

PURPOSE

The aim of this investigation was to comprehensively assess CuE related hepatotoxicity and potential drug-drug interactions involving CYP3A and P-glycoprotein (P-gp).

STUDY DESIGN AND METHODS

Four common cytotoxicity assays (MTS, SRB, NRU and apoptosis assays) were used to evaluate the hepatotoxicity of CuE in human hepatocellular carcinoma HepG2 cells. Human and rat liver microsomes incubation system, Caco-2 transport model and 3D organoids model were used to investigate the effects of CuE on CYP3A and P-gp in vitro. The oral pharmacokinetics of indinavir was employed to evaluate the effects of CuE on CYP3A and P-gp in vivo.

RESULTS

CuE induced the HepG2 apoptosis and exhibited acute cytotoxicity in MTS, SRB, and NRU assays with IC₅₀ value at 15.98µM, 0.31µM, and 1.11µM, respectively. Moreover, CuE not only presented mechanism-based inhibition on human CYP3A4, but also decreased the efflux ratio of digoxin (P-gp substrate) across Caco-2 cell monolayers in vitro. Furthermore, CuE significantly inhibited the transport of Rh123 into 3D organoids, which was caused by the inhibition on P-gp. In Sprague-Dawley rat studies in vivo, acute administration of CuE significantly increased the maximum serum concentration (C_max) and area under the concentration-time curve (AUC) of indinavir. In contrast, CuE treatment for three consecutive days significantly decreased indinavir C_max and AUC in rats.

CONCLUSION

These studies demonstrated that CuE has strong hepatotoxicity, and CuE presents potent inhibition on both CYP3A and P-gp activities in vitro. In animal in vivo studies, CuE induces CYP3A and P-gp after a long-term treatment but inhibits the activities of CYP3A and P-gp after an acute dosing. Therefore, CuE as a dual functional regulator of both CYP3A and P-gp may cause complex drug-drug interactions.

A Novel Model of P-Glycoprotein Inhibitor Screening Using Human Small Intestinal Organoids

P-glycoprotein (P-gp), an important efflux transporter in intestine, regulates the bioavailability of orally taken drugs. To develop an in vitro model that preferably mimics the physiological microenvironment of human intestine, we employed the three-dimensionally (3D) cultured organoids from human normal small intestinal epithelium. It was observed that the intestinal crypts could efficiently form cystic organoid structure with the extension of culture time. Furthermore, the physiological expression of ABCB1 was detected at both mRNA and protein levels in cultured organoids. Rhodamine 123 (Rh123), a typical substrate of P-gp, was actively transported across 3D organoids and accumulated in the luminal space. This transport process was also inhibited by verapamil and mitotane. In summary, the above-mentioned model based on human small intestinal 3D organoids is suitable to imitate the small intestinal epithelium and could be used as a novel in vitro model especially for P-gp inhibitor screening.