scholarly journals Overexpression of P-glycoprotein, MRP2, and CYP3A4 impairs intestinal absorption of octreotide in rats with portal hypertension

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoyu Sun ◽  
Shunxiong Tang ◽  
Binbin Hou ◽  
Zhijun Duan ◽  
Zhen Liu ◽  
...  

Abstract Background Portal hypertension (PH) is the main cause of complications and death in liver cirrhosis. The effect of oral administration of octreotide (OCT), a drug that reduces PH by the constriction of mesenteric arteries, is limited by a remarkable intestinal first-pass elimination. Methods The bile duct ligation (BDL) was used in rats to induce liver cirrhosis with PH to examine the kinetics and molecular factors such as P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2) and cytochrome P450 3A4 (CYP3A4) influencing the intestinal OCT absorption via in situ and in vitro experiments on jejunal segments, transportation experiments on Caco-2 cells and experiments using intestinal microsomes and recombinant human CYP3A4. Moreover, RT-PCR, western blot, and immunohistochemistry were performed. Results Both in situ and in vitro experiments in jejunal segments showed that intestinal OCT absorption in both control and PH rats was largely controlled by P-gp and, to a lesser extent, by MRP2. OCT transport mediated by P-gp and MRP2 was demonstrated on Caco-2 cells. The results of RT-PCR, western blot, and immunohistochemistry suggested that impaired OCT absorption in PH was in part due to the jejunal upregulation of these two transporters. The use of intestinal microsomes and recombinant human CYP3A4 revealed that CYP3A4 metabolized OCT, and its upregulation in PH likely contributed to impaired drug absorption. Conclusions Inhibition of P-gp, MRP2, and CYP3A4 might represent a valid option for decreasing intestinal first-pass effects on orally administered OCT, thereby increasing its bioavailability to alleviate PH in patients with cirrhosis.

Parasitology ◽  
2011 ◽  
Vol 138 (14) ◽  
pp. 1832-1842 ◽  
Author(s):  
V. RISCO-CASTILLO ◽  
V. MARUGÁN-HERNÁNDEZ ◽  
A. FERNÁNDEZ-GARCÍA ◽  
A. AGUADO-MARTÍNEZ ◽  
E. JIMÉNEZ-RUIZ ◽  
...  

SUMMARYHere we present the detection of a gene cluster forNeospora caninumsurface genes, similar to theToxoplasma gondiiSRS9 locus, and the cloning and characterization of the NcSRS9gene. PCR genome walking, using NcBSR4gene as a framework, allows the identification, upstream NcBSR4, of 2 sequences homologous to theSRS5and the Ubiquinol-cytochrome C reductase genes and, downstream NcBSR4, of an ORF of 1191 bp coding for a 396-amino acid polypeptide with 59% similarity to the TgSRS9 antigen. A putative 39-residue signal peptide was found at the NH2-terminus followed by a hydrophilic region, and a potential site for a glycosylphosphatidylinositol anchor at the COOH-terminus. A recombinant NcSRS9 protein was produced and was recognized on a Western blot by a low proportion of sera from a panel of naturally infected cows and calves. In addition, Western blot analysis using polyclonal anti-rNcSRS9 revealed stage-specific expression of NcSRS9 in bradyzoites but not in tachyzoites, and immunohistochemistry on brain from a congenitally infected calf showed NcSRS9 recognition in bradyzoites contained in tissue cysts. However, bradyzoite-specific expression of NcSRS9 could not be proven by immunofluorescence on bradyzoites obtainedin vitroand RT-PCR analysis showed no significant variations of NcSRS9transcripts duringin vitrotachyzoite-bradyzoite switch, probably due to incomplete maturity ofin vitrobradyzoites. Initial characterization of NcSRS9 in this study may lead to further studies for a better understanding ofN. caninumpersistence.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Yan Xu ◽  
Yue Zhang

Abstract Background and Aims Ischemia-reperfusion injury (IRI) is the outcome of an inflammatory process and tubular cell death that is triggered by undergoing a transient reduction or cessation of blood flow and following by reperfusion. Unresolved IRI can contribute to chronic kidney disease even death. Our aims is to investigate the protective effect of hyperin on ischemia-reperfusion renal injury (IRI) and its possible mechanism. Method ① The transcriptome chip data of multiple IRI models were selected from the NCBI GEO DateSets database and a number of key proteins that could participate in IRI were screened out (the fold increase was greater than 2 fold and was statistically significant). Network and transcript binding motif analysis was performed to determine the best binding protein. ② C57BL / 6J mice were selected and randomly divided into normal group, sham operation group, IRI group (bilateral renal pedicle clamping for 45min), hyperin + IRI group (50mg / kg.d per day, 7 days before surgery ), DMSO + IRI group (7 days before the operation, the same amount of DMSO was administered to the stomach every day, and the operation was the same as AKI), with 6 rats in each group. Renal tissue and blood were collected 24 hours after operation for testing. ③ In vitro experiments, human proximal tubule epithelial cells (HK-2) were selected and divided into hypoxia 3, 6, 9, 12, 24, 36, and 48h for reoxygenation of 1, 3, and 6h respectively. Relevant indicators for RT-PCR detection were determined Optimal hypoxia time. The drug safe concentration was selected according to 0, 5, 10, 25, 50, 100, 200, 400 μg / ml hyperin pre-treatment for 12 hours, and the CCK8 reagent was added for 2 hours to measure the absorbance at 450 nm. The cells were randomly divided into normal group, hypoxia group, hypoxia + DMSO group, hypoxia + hyperin group, and related indexes were detected by RT-PCR and Western Blot. ④ Obtain the tertiary structure of the protein and the three-dimensional structure of the hyperin molecule from the RCSB Protein Data Bank website and the PubChem compound database, and use molecular docking technology to determine the proteins that can bind to hyperin using autodock software and analyze their binding ability. Results Bioinformatics analysis suggested that STK40 protein is one of the key factors of IRI and may be a target for preventing and treating diseases. In vivo experiments showed that compared with the normal group and the sham operation group, the levels of serum creatinine, blood urea nitrogen, and kim-1 in rats were significantly increased after AKI, and HE staining of pathological sections showed an increase in renal tubular injury scores. Significantly decreased (P<0.05); RT-PCR results showed that kim-1, caspase-3, NF-κB, IL-6, TNF-α increased significantly after AKI, STK40, Bcl2 / BAX decreased, and the above after hyperin The indicators changed in opposite directions (P <0.05). In vitro experiments: The best time for hypoxia is 24h hypoxia + 1h reoxygenation; compared with the control group, the drug concentration is <100 μg / mL and the cell proliferation activity rate is> 90%, so the hyperin concentration was selected as 50 μg / mL (P < 0.05); RT-PCR results showed that Hif1-α, caspase-3, NF-κB, IL-6, TNF-α significantly increased, and STK40, Bcl2 / BAX decreased compared with the normal group. After administration of hyperin, the above indexes changed in opposite directions (P <0.05). Conclusion In this study, using molecular docking technology and constructing IRI mice model, it was confirmed that hyperin can reduce IRI and exert a protective effect on IRI by inhibiting STK40 expression.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Peng Zhou ◽  
Ruihui Weng ◽  
Zhaoyu Chen ◽  
Rui Wang ◽  
Jing Zou ◽  
...  

Aims.This work was conducted to establish anin vitroParkinson’s disease (PD) model by exposing BV-2 cells to 1-methyl-4-phenylpyridinium (MPP+) and exploring the roles of TLR2/TLR4/TLR9 in inflammatory responses to MPP+.Methods/Results.MTT assay showed that cell viability of BV-2 cells was 84.78 ± 0.86% and 81.18 ± 0.99% of the control after incubation with 0.1 mM MPP+for 12 hours and 24 hours, respectively. Viability was not significantly different from the control group. With immunofluorescence technique, we found that MPP+incubation at 0.1 mM for 12 hours was the best condition to activate BV-2 cells. In this condition, the levels of TNF-α, IL-1β, and iNOS protein were statistically increased compared to the control according to ELISA tests. Real time RT-PCR and western blot measurements showed thatTLR4was statistically increased after 0.1 mM MPP+incubation for 12 hours. Furthermore, after siRNA interference ofTLR4mRNA, NF-κB activation and the levels of TNF-α, IL-1β, and iNOS were all statistically decreased in this cell model.Conclusion.MPP+incubation at the concentration of 0.1 mM for 12 hours is the best condition to activate BV-2 cells for mimicking PD inflammation in BV-2 cells. TLR4 signalling plays a critical role in the activation of BV-2 cells and the induction of inflammation in this cell model.


2002 ◽  
Vol 50 (10) ◽  
pp. 1351-1356 ◽  
Author(s):  
Konrad Meissner ◽  
Bernhard Sperker ◽  
Christiane Karsten ◽  
Henriette Meyer zu Schwabedissen ◽  
Ute Seeland ◽  
...  

ABC-type transport proteins, such as P-glycoprotein (P-gp), modify intracellular concentrations of many substrate compounds. They serve as functional barriers against entry of xenobiotics (e.g., in the gut or the blood-brain barrier) or contribute to drug excretion. Expression of transport proteins in the heart could be an important factor modifying cardiac concentrations of drugs known to be transported by P-gp (e.g., β-blockers, cardiac glycosides, doxorubicin). We therefore investigated the expression and localization of P-gp in human heart. Samples from 15 human hearts (left ventricle; five non-failing, five dilated cardiomyopathy, and five ischemic cardiomyopathy) were analyzed for expression of P-gp using real-time RT-PCR, immunohistochemistry, and in situ hybridization. Immunohistochemistry revealed expression of P-gp in endothelium of both arterioles and capillaries of all heart samples. Although P-gp mRNA was detected in all samples, its expression level was significantly reduced in patients with dilated cardiomyopathy. We describe variable expression of P-gp in human heart and its localization in the endothelial wall. Thus, intracardiac concentrations of various compounds may be modified, depending on the individual P-gp level.


2021 ◽  
Author(s):  
Shanshan Ou ◽  
Yinchao Fang ◽  
Tong Wu ◽  
Jie Xu ◽  
Kaihua Guo

Abstract Alzheimer’s disease (AD) is a neurodegenerative condition associated with oxidative stress and neuroinflammation. Lycopene has previously been shown to ameliorate neuroinflammation and exert protection against oxidative damage in neuroblastoma cells. The role of this compound in reversing cognitive dysfunction in AD has yet to be determined. The present study investigates the role of lycopene in AD with an in vitro Aβ1-42-induced cell cytotoxicity model as well as the in vivo APP/PS1 mouse model. The activation of Nrf2 signal pathway was assessed using western blot and RT-PCR. MDA, 8-OHdG, ROS, SOD, GHS and GSSG measurements were carried out using the specialized assay kits. The Morris water maze was used to examine qualitative assessment of memory and spatial learning. Immunofluorescence was used to visualize astrocytes and microglia activation as well as brain β-amyloid (Aβ) deposition. The NeuN positive cells were detected by immunofluorescence and western blot. Levels of cerebral cytokines were quantified using RT-PCR. Lycopene ameliorates oxidative damage in the Aβ1-42-triggered cell cytotoxicity model via Nrf2-ARE signal pathway activation, which is regulated by AKT-GSK3β pathway. In addition, lycopene improves the cognitive impairment and reduces the Aβ deposition. Mechanistically, lycopene attenuates neuron loss, decreases chronic inflammation and activates cerebral Nrf2-ARE signaling pathway in APP/PS1 mice. The results suggest that lycopene alleviates oxidative stress via AKT- Nrf2-ARE pathway. And early administration of lycopene improves cognitive deficits by reducing Aβ deposition, neuronal loss and decreasing the degree of chronic inflammation.


Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4384 ◽  
Author(s):  
Nannan Li ◽  
Wenxiao Men ◽  
Yibo Zheng ◽  
Hechen Wang ◽  
Xiansheng Meng

This study aims to investigate the anticancer effect of Oroxin B (OB) both in vitro and in vivo, and the molecular mechanism involved in microRNA-221 and the PI3K/Akt/PTEN pathway through modulation of apoptosis in Hepatocellular carcinoma (HCC). DEN-induced rats and HepG2 cells based on the microfluidic chip were employed, while the mRNA and protein expression of microRNA-221, PI3K, p-Akt and PTEN were evaluated by RT-PCR and Western blot analysis. Based on Microfluidic Chip and DENinduced rat model, OB effectively exerts anti-liver cancer effect both in vitro and in vivo, and the expression of miR-221 in OB treated groups was significantly lower than that in the control group (** p < 0.01). The RT-PCR and Western blot results suggested the PI3K mRNA and protein in OB treated groups were both lower than those in control group and indicated the overexpression of PTEN. Therefore, OB effectively exerts anticancer effects by positively regulating the PTEN gene and then inactivating the PI3K/Akt signaling pathway through down-regulating the expression of the microRNA-221, thereby inducing apoptosis of liver cancer cells. This study offers a theoretical evidence for further development and clinical guidance of OB as an anti-tumor agent.


Planta Medica ◽  
2014 ◽  
Vol 80 (04) ◽  
pp. 290-296 ◽  
Author(s):  
Na Li ◽  
Dandan Wang ◽  
Guangbo Ge ◽  
Xiuli Wang ◽  
Yong Liu ◽  
...  

2016 ◽  
Vol 19 (3) ◽  
pp. 485-494 ◽  
Author(s):  
R. Lin ◽  
Q. Wang ◽  
B. Qi ◽  
Y. Huang ◽  
G. Yang

Abstract Neuromedin S (NMS), a 36-amino acid neuropeptide, has been found to be involved in the regulation of the endocrine activity. It has been also detected in immune tissues in mammals, what suggests that NMS may play an important role in the regulation of immune response. The aim of this study was to demonstrate the presence of NMS receptor 1 (NMU1R) and effect of NMS in pig splenic lymphocytes (SPLs) and pulmonary alveolar macrophages (PAMs). The presence of NMU1R in pig SPLs and PAMs was respectively confirmed by reverse transcription-polymerase chain reaction (RT-PCR), western blot analysis and immunocytochemical methods. Furthermore, SPL proliferation was analyzed using the 3-(4,5)-dimethyl-thiahiazo-(-2-yl)-3,5-di-phenytetrazoliumromide (MTT) method. Additionally, the secretion of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in PAMs was all measured by enzyme-linked immunosorbent assay (ELISA) kits. In the present study, the results of RT-PCR and western blot analysis revealed that NMU1R mRNA and protein were both expressed in pig SPLs and PAMs, and the immunocytochemical investigations further revealed that the positive signal of NMU1R immunoreactivity was observed in plasma membranes of both SPLs and PAMs. In the in vitro study, we found that at concentrations of 0.001-1000 nM NMS alone or combined with lipopolysaccharide or phytohemagglutinin significantly increased SPL proliferation. Application of ELISA method showed that NMS could induce the secretion of the pro-inflammatory cytokines IL-1β, IL-6 and TNF-α in PAMs. These results suggest that NMS can act as a potently positive pro-inflammatory factor and immunomodulatory agent that affects the immune response of immune cells by combining with its receptor NMU1R.


2004 ◽  
Vol 70 (9) ◽  
pp. 5222-5228 ◽  
Author(s):  
Usanee Anukool ◽  
William H. Gaze ◽  
Elizabeth M. H. Wellington

ABSTRACT The onset of streptothricin (ST) biosynthesis in Streptomyces rochei F20 was studied by using reverse transcription-PCR (RT-PCR) to detect transcripts of ST genes during growth in liquid medium, soil, and the rhizosphere. In situ results correlated with those obtained in vitro, illustrating the growth phase-dependent manner of ST production by F20. Maximal transcription of ST resistance (sttR) and biosynthesis (sttA) genes occurred during the transition between the exponential and stationary phases of growth, when the specific growth rate (μ) started to decline. A higher level of gene expression of sttR versus sttA was observed in all experiments. In liquid culture, maximal transcript accumulation of the sttA gene was only ca. 40% that of the sttR gene. sttA and sttR mRNAs were detected in soil containing approximately 106 CFU of growing cells g of soil−1. sttR mRNA was detected in sterile and nonsterile rhizosphere colonized with growing mycelium of F20 at 1.2 × 106 and 4.0 × 105 CFU g of soil−1, respectively. However, neither sttR nor sttA transcripts were detected by RT-PCR in the rhizoplane, which supported a lower population density of F20 than the rhizosphere.


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