As a basic amino acid, histidine has a pK_a close to the acidity of the tumor microenvironment, thus the charge and solubility of histidine are able to vary as the pH changes. Under a neutral environment, histidine is not charged and exhibits hydrophobic properties, while it can be protonated and becomes hydrophilic when exposed to mildly acidic pH, such as tumor microenvironment. Therefore, histidine is widely used in the design of drug delivery systems to target the mildly acidic pH of tumor microenvironment. This article reviews the recent progresses of histidine-based tumor-targeting drug delivery systems, and summarizes the principles on promoting internalization and tuning drug release by taking advantage of histidine. Finally, we point out the common issues on histidine application and illustrate its future prospects.

Organic anion transporting polypeptide 1B1 (OATP1B1) is an important liver-specific uptake transporter, which mediates transport of numerous endogenous substances and drugs from blood into hepatocytes. To identify and investigate potential modulators of OATP1B1 from natural products, the effect of 21 frequently used natural compounds and extracts on OATP1B1-mediated fluorescein methotrexate transport was studied by using Chinese hamster ovary cells stably expressing OATP1B1 (CHO-OATP1B1) in 96-well plates. This method could be used for the screening of large compound libraries. Our studies showed that some flavonoids (e.g., quercetin, quercitrin, rutin, chrysanthemum flavonoids and mulberrin) and triterpenoids (e.g., glycyrrhetinic acid and glycyrrhizic acid) were inhibitors of OATP1B1 with IC50 values less than 16 µmol · L(-1). The IC50 value of glycyrrhetinic acid on OATP1B1 was comparable to its blood concentration in clinics, indicating an OATPlB1-mediated drug-drug interaction could occur. Structure-activity relationship analysis showed that flavonoids had much higher inhibitory activity than their glycosides. Furthermore, the type and length of saccharides had a significant effect on their activity. In addition, we used OATP1B1 substrates fluvastatin and rosuvastatin as probe drugs to investigate the substrate-dependent effect of several natural compounds on the function of OATP1B1 in vitro. Our results demonstrated that the effect of these natural products on the function of OATPlB1 was substrate-dependent. In summary, this study would be conducive to predicting and avoiding potential OATP1B1-mediated drug-drug and drug-food interactions and thus provide the experimental basis and guidance for rational drug use.
Animals ; Biological Products ; CHO Cells ; Cricetulus ; Drug Interactions ; Fatty Acids, Monounsaturated ; pharmacology ; Flavonoids ; pharmacology ; Indoles ; pharmacology ; Inhibitory Concentration 50 ; Organic Anion Transporters ; genetics ; metabolism ; Rosuvastatin Calcium ; pharmacology ; Structure-Activity Relationship

AIM To investigate the effect of fenofibrate and simvastatin on the serum free fatty acids of alcoholic fatty liver in rats. METHODS The rat model of alcoholic fatty liver was reproduced by chronic ethanol ingestion plus olive oil diet. The model rats were divided into three groups as follows: finofibrate treatment group(finofibrate 80 mg?kg -1 po, once a day),simvastatin treatment group (simvastatin 4 mg?kg -1 po, once a day)and control group without either above-mentioned treatment. Experimental rats were treated for four weeks and then sacrificed for blood sampling. Serum free fatty acids were analyzed by gas chromatography. RESULTS Fenofibrate significantly ameliorated the decrease in polyunsaturated fatty acids induced by ethanol [oleic acid:(38.212?7.788) ?g?L -1 vs (31.620?6.142) ?g?L -1,linoleic acid:(37.269?8.065) ?g?L -1 vs (30.254?9.063) ?g?L -1,arachidonic acid:(11.646?2.601) ?g?L -1 vs (9.012?1.236) ?g?L -1] accompanied by the improvement of the fat infiltration of the liver, but demonstrated no effect on the increase in serum saturated fatty acids by ethanol. In the contrast, simvastatin can aggravate the decrease in polyunsatrurated fatty acids and significantly increase the levels of satrurated fatty acids in serum induced by ethanol along with the pathological aggravation of alcoholic fatty liver. CONCLUSION The results of present study revealed that fenofibrate and simvastatin exerted different effect on the serum free fatty acids of alcoholic fatty liver. Polyunsatrurated fatty acids in the serum play an important role in the pathogenesis and treatment response of alcoholic fatty liver.

The exploration of drug toxicity and mechanisms is a vital component in ensuring the safe use of drugs in clinical practice, as this topic has attracted widespread concern. The intestinal flora holds great significance for drug metabolism, efficacy and mechanism, and is an instrumental metabolic organ that facilitates material information transfer and biotransformation. However, an increasing number of studies have shown that intestinal bacteria are closely related to the toxicity of specific drugs. On the one hand, drugs are transformed into toxic metabolites under the influence of intestinal bacteria, thus inducing direct drug toxicity. On the other hand, the composition and function of the intestinal flora are altered under drug influence, resulting in disruption of endogenous metabolic pathways. Consequently, this disruption compromises the intestinal barrier and affects other organs, leading to indirect drug toxicity. This review meticulously compiles recent examples of drug toxicity attributed to intestinal bacteria, explores in depth the contention that metabolic enzymes of gut microbiota may be of great influence on oral drug toxicity, and outlines prospective avenues for future research on gut microbiota and drug toxicity and mechanisms. This not only provides novel perspectives for the judicious clinical utilization of drugs but also offers insights for the safety assessment of innovative pharmaceuticals.

A gene that could be potentially involved in spermatogenesis was identified and characterized by using suppression subtractive hybridization (SSH) and rapid amplification of cDNA ends (RACE) with total RNA from type A spermatogonia and pachytene spermatocytes of rat. This gene consists of 3 433 base pairs (bp) with a complete open reading frame (ORF) of 3 171 bp and encodes a putative protein containing 1057 amino acids. The nucleotide sequence displays a 93% identity to mouse ubiquitin-activating enzyme E1, Chr Y 1 (Ube1y1) and an 82% identity to human ubiquitin-activating enzyme E1 (UBE1). The putative protein of this gene contains an ubiquitin-activating enzyme signature 1 and an ubiquitin-activating enzyme active site, which are also existed in mouse ubiquitin-activating enzyme E1, human ubiquitin-activating enzyme E1 et al. So we named this gene as Rattus norvegicus ubiquitin-activating enzyme E1 (Ube1). The sequence of Ube1 was submitted to GenBank and the accession number is EF690356. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that Ube1 was specifically expressed in testis, while its expression was not detected in heart, brain, spleen, lung, liver, muscle, kidney and ovary. Comparison of the expression of Ube1 in different developmental stages of testis and Sertoli cells (real-time PCR) indicated that Ube1 was expressed more highly in spermatogonia than in spermatocytes, spermatids and Sertoli cells. In conclusion, Ube1 is a gene encoding rat ubiquitin-activating enzyme E1 and specifically expressed in testis, which might play a key role in ubiquitin system and influence spermatogenesis.
Animals ; DNA, Complementary ; genetics ; Male ; Rats ; Real-Time Polymerase Chain Reaction ; Spermatids ; metabolism ; Spermatocytes ; metabolism ; Spermatogenesis ; genetics ; Spermatogonia ; metabolism ; Testis ; metabolism ; Ubiquitin-Activating Enzymes ; genetics ; metabolism

Objective To assess the quantitative relationship between the distribution of Himalayan marmot and its ecological environment,the terrain,the temperature and the precipitation,using remote sensing and geographic information system in Qinghai province.Methods The distribution of Himalayan marmot was located by Google Earth and ArcGIS software and by using field survey data provided by Chinese Center for Disease Control and Prevention.The corresponding ecological environment of marmot including terrain,temperature and precipitation were derived from the spatial information datasets.All results were processed according to the overlay and statistics analysis using ArcGIS software.Results Seventy-seven point twenty-seven percent(153/198) of Himalayan marmot were distributed in the area of elevation between 3000 and 4000 meters.The number of marmot reached the highest when the slope was between 0 and 17 degrees,and aspect range was between 91 and 270 degrees,180 degree was as south direction.During the period with the maximum temperature of the warmest month of 14.3-17.5 ℃,17.6-20.8 ℃ and 20.9-24.0 ℃,the distribution of marmot reached 95％(186/198) of the total area.Meanwhile,most of the marmot were presented in the area with average precipitation of 46-108 mm.Conclusions A quantitative analysis of appropriate ecological environment of Himalayan marmot in a large scope is carried uul successfully using remote sensing and geographic information system.The study indicates that spatial information technology has important applications in plague prevention and control.

Leukemia is a type of malignant tumors of hematopoietic system with the abnormal increased immature leukemia cells showing metastasis and invasion ability. Liver is one of the main targets of the leukemia cells spread to, where they may continue to proliferate and differentiate and cause liver function damage, even liver failure. Our previous studies showed that Angelica polysscharides (APS), the main effective components in Angelica sinensis of Chinese traditional medicine, was able to inhibit the proliferation and induced differentiation of the leukemia cells, however, its effect on the liver during the treatment remains elucidated. In the present study, the human leukemia NOD/SCID mouse model were established by implantation human leukemia K562 cells line, then the leukemia mouse were treated with APS, Ara-c or APS + Ara-c respectively by peritoneal injection for 14 days, to explore the effect and mechanism of the chemicals on the mouse liver. Compared to the human leukemia NOD/SCID mouse model group with the treatments of APS, Ara-c and APS + Ara-c, We found that severe liver damage and pathological changes of the liver were able to alleviate: First, the number of white blood cells in the peripheral blood was significantly lower and with less transplanted K562 leukemia cells; Second, liver function damage was alleviated as liver function tests showed that alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBiL) were significantly reduced, while the albumin (Alb) was notably increased; Third, liver antioxidant ability was improved as the activities of the antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were significantly increased, and the contents of GSH and malonaldehyde (MDA) were decreased significantly in the liver; Fourth, the inflammation of the liver was relieved as the level of IL-1beta and IL-6, the inflammatory cytokines, were decreased significantly in the liver. Fifth, liver index was increased as the pathological observation showed that leukemia cells with diffused infiltration into the liver lobules were significantly reduced and with a remarkable increase of apoptotic positive cell rate by TUNEL test. Furthermore, the APS + Ara-c combined administration showed an even more significant positive effect. In conclusion, the APS, Ara-c therapy reduced the accumulation of leukemia cells within the liver, reduced the liver function damage and levels of inflammatory factors, improved antioxidant capacity of the liver tissue and thus alleviate the pathological changes of the liver. Moreover, the APS + Ara-c combination therapy may have an additive effect.
Angelica ; chemistry ; Animals ; Antineoplastic Combined Chemotherapy Protocols ; pharmacology ; Cell Line, Tumor ; Cytarabine ; administration & dosage ; Humans ; K562 Cells ; Leukemia ; drug therapy ; Liver ; drug effects ; Male ; Mice ; Mice, SCID ; Polysaccharides ; administration & dosage

To screen differentially expressed genes involved in osteogenic differentiation of human bone marrow stromal cells (BMSCs) at defined stages, subtractive cDNA library was established by means of suppression subtractive hybridization. The BMSCs cultured for 12 and 21 d were used as driver and tester, respectively. A subtract library was successfully constructed and five positive clones were selected from the library. Sequencing analysis and homology comparison showed that the five clones differentially expressed in BMSCs cultured for 21 d were at least 90% homologous with the known genes in human GenBank. It was interestingly found that the osteogenic BMSCs cultured for 21 d differentially expressed decorin and Bax inhibitor 1. RT-PCR was performed to confirm the differentially expressed genes. The results showed that the expression of Bax inhibitor 1 was significantly higher in the cells of 21-day than that of 12-day, while the expression of decorin was only detected in the cells of 21-day.
Apoptosis Regulatory Proteins ; genetics ; metabolism ; Cell Differentiation ; genetics ; Cells, Cultured ; Decorin ; genetics ; metabolism ; Gene Expression Profiling ; Gene Expression Regulation ; Gene Library ; Humans ; Membrane Proteins ; genetics ; metabolism ; Mesenchymal Stromal Cells ; cytology ; Osteoblasts ; cytology

It has been known that the glutamate transmission system and N-methyl-D-aspartate receptor (NMDA-R) were possibly related to anxiety processes. Although anxiety symptom can be relieved by NMDA-R antagonists and partial agonists treatment, the functions of NMDA-R and its subunits in anxiety behaviors remain unclear. We used forebrain specific NR2B over-expression mice to examine whether the increase of NR2B subunit level would induce anxiety behaviors. The results indicated that the juvenile (3-5 months old), middle-aged (8-10 months old) and old (19-22 months old ) NR2B transgenic mice showed no significant difference in open field test and elevated plus maze test as compared with the control mice. Capillary electrophoresis of monoamine neurotransmitter in subregions of forebrain revealed no significant difference between transgenic and control mice of 16-18 months age. These results suggest that the increase of NR2B expression and followed NR1 and NR2A expression augmentations in the forebrain have no significant effect on anxiety-related behaviors in mice.
Animals ; Anxiety ; metabolism ; Mice ; Mice, Transgenic ; Prosencephalon ; metabolism ; Receptors, N-Methyl-D-Aspartate ; metabolism

OBJECTIVETo explore the biological mechanisms underlying Angelica sindsis polysaccharide (ASP) -induced aging of human-derived leukemia stem cells (LSCs) in vitro.

METHODAcute myelogenous leukemia stem cells were isolated by magnetic activated cell sorting (MACS). The ability of LSC proliferation treated by various concentration of ASP(20-80 mg · L(-1)) in vitro for 48 hours were tested using cell counting Kit-8 ( CCK8) , colony forming were evaluated by methylcellulose CFU assay. The ultra structure changes of AML CD34+ CD38- cells were analyzed by transmission electron microscopy. The aging cells were detected with senescence-β-galactosidase Kit staining. Expression of aging-related p53, p21, p16, Rb mRNA and P16, Rb, CDK4 and Cyclin E protein were detected by quantitative reverse transcription polymerase chain reaction( qRT-PCR) and Western blotting, respectively.

RESULTThe purity of the CD34 + CD38 - cells is (91.15 ± 2.41)% after sorted and showed good morphology. The proliferation of LSC was exhibited significantly concentration-dependent inhibited after exposure to various concentration of ASP. Treated by 40 mg · L(-1) ASP for 48 hours, the percentage of positive cells stained by SA-β-Gal was dramatically increased (P < 0.01) and the colony-formed ability has been weakened (P < 0.01). The observation of ultrastructure showed that cell heterochromatin condensation and fragmentation, mitochondrial swelling, lysosomes increased in number. Aging-related p53, p21, p16, Rb and P16, Rb were up-regulated, protein regulatory cell-cycle CDK4 and Cyclin E were down-regulated. ASP may induce the senescence of LSCs effectively in vitro, P16-Rb cell signaling pathway play a significant role in this process.

CONCLUSIONASP can induce human leukemia stem cell senescence in vitro, the mechanism involved may be related to ASP regulation P16-Rb signaling pathways.

Angelica sinensis ; chemistry ; Cell Cycle ; drug effects ; Cell Cycle Proteins ; genetics ; metabolism ; Cells, Cultured ; Cellular Senescence ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Leukemic ; drug effects ; Humans ; Leukemia ; drug therapy ; genetics ; metabolism ; physiopathology ; Neoplastic Stem Cells ; cytology ; drug effects ; Polysaccharides ; pharmacology ; Signal Transduction ; drug effects