Role of Glucose Transporters in Drug Membrane Transport

BACKGROUND

Glucose is the main energy component of cellular activities. However, as a polar molecule, glucose cannot freely pass through the phospholipid bilayer structure of the cell membrane. Thus, glucose must rely on specific transporters in the membrane. Drugs with a similar chemical structure to glucose may also be transported through this pathway.

METHODS

This review describes the structure, distribution, action mechanism and influencing factors of glucose transporters and introduces the natural drugs mediated by these transporters and drug design strategies on the basis of this pathway.

RESULTS

The glucose transporters involved in glucose transport are of two major types, namely, Na+-dependent and Na+-independent transporters. Glucose transporters can help some glycoside drugs cross the biological membrane. The transmembrane potential is influenced by the chemical structure of drugs. Glucose can be used to modify drugs and improve their ability to cross biological barriers.

CONCLUSION

The membrane transport mechanism of some glycoside drugs may be related to glucose transporters. Glucose modification may improve the oral bioavailability of drugs or achieve targeted drug delivery.

Metabolism and Toxicity of Emodin: Genome-Wide Association Studies Reveal Hepatocyte Nuclear Factor 4α Regulates UGT2B7 and Emodin Glucuronidation

Emodin is the main toxic component in Chinese medicinal herbs such as rhubarb. Our previous studies demonstrated that genetic polymorphisms of UDP-glucuronosyltransferase 2B7 (UGT2B7) had an effect on the glucuronidation and detoxification of emodin. This study aimed to reveal the transcriptional regulation mechanism of UGT2B7 on emodin glucuronidation and its effect on toxicity. Emodin glucuronic activity and genome and transcriptome data were obtained from 36 clinical human kidney tissues. The genome-wide association studies (GWAS) identified that four single nucleotide polymorphisms (SNPs) (rs6093966, rs2868094, rs2071197, and rs6073433), which were located on the hepatocyte nuclear factor 4α (HNF4A) gene, were significantly associated with the emodin glucuronidation (p < 0.05). Notably, rs2071197 was significantly associated with the gene expression of HNF4A and UGT2B7 and the glucuronidation of emodin. The gene expression of HNF4A showed a high correlation with UGT2B7 (R² = 0.721, p = 5.83 × 10^-11). The luciferase activity was increased 7.68-fold in 293T cells and 2.03-fold in HepG2 cells, confirming a significant transcriptional activation of UGT2B7 promoter by HNF4A. The knockdown of HNF4A in HepG2 cells (36.6%) led to a significant decrease of UGT2B7 (19.8%) and higher cytotoxicity (p < 0.05). The overexpression of HNF4A in HepG2 cells (31.2%) led to a significant increase of UGT2B7 (24.4%) and improved cell viability (p < 0.05). Besides, HNF4A and UGT2B7 were both decreased in HepG2 cells and rats after treatment with emodin. In conclusion, emodin used long term or in high doses could inhibit the expression of HNF4A, thereby reducing the expression of UGT2B7 and causing hepatotoxicity.

The Impact of Physicians' Working Hours on Inappropriate Use of Outpatient Medicine in a Tertiary Hospital in China

BACKGROUND

Inappropriate prescribing is an important health system problem in China. Several studies have identified critical factors influencing prescription quality, but the impact of physicians' working hours remains unknown. In China, tertiary hospitals face ever-increasing outpatient volumes. Physicians are asked to work long hours and the impact of shift duration on prescription quality is unknown.

OBJECTIVE

We aimed to investigate the association between consecutive working hours and the quality of physicians' prescriptions in a Chinese tertiary hospital.

METHODS

We obtained all outpatient electronic health records from the hospital information system (HIS) of a tertiary hospital in Beijing, China from 1 July to 30 November 2015. Prescriptions made during two periods were analyzed: a morning shift from 7:30 to 12:30, and an afternoon shift from 13:30 to 18:30. The time when a physician issued the first prescription was considered the beginning of the work shift and prescriptions within the next 4 consecutive hours were included. Potentially inappropriate prescriptions were based on the Rational Drug Use (RDU) system that was developed and validated for this study. We used multivariable logistic regression to examine the impact of shift duration and other clinical and physician factors on potentially inappropriate prescribing.

RESULTS

Of the total 560,529 prescriptions, 15.3% were classified as inappropriate by the RDU system. Physicians' inappropriate prescribing increased in the last hour in each work shift (odds ratio (OR) for the fourth hour compared to the first = 1.12 (95% CI, 1.09-1.15)). We also found that physicians who worked all day had a higher rate of inappropriate prescribing than those who only worked half a day (OR = 1.05 (95% CI, 1.04-1.07)).

CONCLUSIONS

Longer working hours are a risk factor for inappropriate prescribing. Relevant interventions are urgently needed to establish working hour limits in China to reduce the likelihood of inappropriate prescribing by physicians.

PARE0026 WHICH PATIENT-REPORTED OUTCOMES DO RHEUMATOLOGY PATIENTS FIND IMPORTANT TO TRACK DIGITALLY? A REAL-WORLD LONGITUDINAL STUDY IN ARTHRITISPOWER

Background:

Development of a standardized approach to assess key elements of disease activity in rheumatology clinical trials has been the goal of Outcome Measures in Rheumatology Clinical Trials (OMERACT), American College of Rheumatology (ACR), and European League Against Rheumatism (EULAR).1,2,3The core sets of measures developed include assessments and composite indices incorporating use of patient-reported outcomes (PROs) and clinical measures and clinicians’ assessments to quantify disease activity over time.2PROs are important indicators of disease activity and variability, and they are increasingly used to evaluate treatment effectiveness. Little is known about PROs that patients with rheumatic conditions find most important to convey their experience with their condition and its treatment.

Objectives:

To examine PROs selected by patients with rheumatic conditions in the ArthritisPower registry to identify symptoms they found most important to track digitally.

Methods:

Adult US patients within the ArthritisPower registry with rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), osteoporosis (OP), osteoarthritis (OA), and fibromyalgia syndrome (FMS) were invited via email to participate in this study. Enrolled participants (pts) were prompted to select ≤10 PRO symptom measures they felt were important to track for their condition at baseline via the ArthritisPower app. At 3 subsequent time points (Month [m] 1, m2, m3), pts were given the option to continue tracking their previously selected PRO measures or to add, remove and/or select different measures. At m3, pts completed an exit survey to prioritize ≤5 measures from all measures selected during study participation and to specify other symptoms not available that they would have wanted to track. Measures were rank-ordered based on number of pts rating the item as their 1st, 2nd, 3rd, 4th or 5th choice and weighted by multiplying the rank number by its inverse for a single, weighted summary score for each measure. Values were summed across all pts to produce a summary score for each measure.

Results:

Among pts who completed initial selection of PRO assessments at baseline (N=253), 184 pts confirmed or changed PRO selections across m1-3. Mean (SD) age of pts was 55.7 (9.2) yrs, 89.3% female, 91.3% White, mean disease duration of 11.6 (10.6) yrs. The majority (64.8%) self-reported OA, followed by RA (48.6%), FMS (40.3%), PsA (26.1%), OP (21.0%), AS (15.8%) and SLE (5.9%), not mutually exclusive, and were similar to the overall ArthritisPower population. The average number of instruments (SD) selected for baseline completion was 7.0 (2.5), 7.1 (2.4) at m1, 7.2 (2.4) at m2, and 7.0 (2.5) at m3. The top 5 PROs ranked by pts overall as most important (weighted summary score) for tracking were Fatigue (71), Physical Function (58), Pain Intensity (50), Pain Interference (49), Duration of Morning Joint Stiffness (41) (Figure 1). Fatigue, Physical Function, and Pain were consistently in the top 5 across diseases while Depression was more frequent among pts with OA, AS and FMS. Pts’ PRO selections showed stability over time except for the RA Flare measure which decreased from 70.5% of RA pts at baseline to 13.6% at m3.

Conclusion:

The symptoms prioritized by pts included fatigue, physical function, pain, and joint stiffness. Pts‘ choices were consistent over time. These findings provide insights into symptoms rheumatology patients find most important and will be useful to inform design of future patient-centric clinical trials and real-world evidence generation.

References:

[1]Boers M, et al. J Rheumatol Suppl. 1994;41:86–89.

[2]Felson DT, et al. Arthritis Rheum. 1993;36:729–740.

[3]Tugwell P, et al. J Rheumatol. 1993;20:555–556.

Disclosure of Interests:

W. Benjamin Nowell: None declared, Carol L. Kannowski Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Kelly Gavigan: None declared, Zhihong Cai Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Anabela Cardoso Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Theresa Hunter Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Shilpa Venkatachalam: None declared, Julie Birt Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Jennifer Workman Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Jeffrey Curtis Grant/research support from: AbbVie, Amgen, Bristol-Myers Squibb, Corrona, Janssen, Lilly, Myriad, Pfizer, Regeneron, Roche, UCB, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Corrona, Janssen, Lilly, Myriad, Pfizer, Regeneron, Roche, UCB

Circulating tumor DNA (ctDNA) to evaluate stage III and stage IV metastatic breast cancer (MBC), describe tumor heterogeneity, and outcome

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Background: MBC is a challenging clinical condition treated with palliative intent due to tumor heterogeneity. We reported in 2019 ASCO that the correlation of HER2 and ESR1 mutations of ctDNA with CTCs results in worse prognosis in MBC. Here we reported that ctDNA mutations is a key point which is different between Stage III and Stage IV, and it would be helpful to evaluate the MBC metastasis and outcome. Methods: This study included 33 Stage III and 204 Stage IV MBC patients who received systemic treatments at NMH (2016-2019). Plasma ctDNA before treatment was isolated from patients and then was analyzed by Guardant 360 Health NGS-based assay for a 73 genes panel for genomic alterations including single nucleotide variants, insertions/deletions, gene fusions/rearrangements and copy number variations. Causal Inference with Ensembel Learning was used for statistical analyses. Results: Among stage III patients, 40% are luminal, 44% are HER2+ and 16% are TNBC, while in stage IV 50% patients are luminal, 20% are HER2+ and 30% are TNBC. The major differences in ctDNA between two stages lie in several genes including PIK3CA, ERBB2 and KRAS. On the top of the list is PIK3CA, which is detected in 2 out of 33 stage III patients (1 luminal, 1 HER2+) (6.06%) in baseline, each of them carries 1 mutation on PIK3CA (E542K, E545G). In 43 out of 204 stage IV patients (21.57%) who carry this gene, 15 show 1 amplification, 34 have 1 mutation (mainly H1047R, E542K, E545K and H1047L), 11 have 2 mutations (E542K/E726K, D454N/D1029N, E545K/D1017H, E545K/L287L, H1047R/E453K, H1047R/N426S and P539R/H1047R), and 1 has 3 mutations (E542Q/D454N/D1029N and E545K/E726K/R93Q). On treatment effects, PIK3CA is found to be very detrimental on prognosis and on its effects on the treatment outcome. Patients without any mutation in PIK3CA live 2.65 times longer than those with more than one mutations on PIK3CA ( p-value = 4.47e-06, CI = [1.731, 3.926]). PIK3CA, ESR1, TP53 and ARID1A are found to significantly affect liver metastasis when RET, FBXW7, ERBB2, CCND2, BRAF and MET are found to be associated with lung metastasis for both stages. EGFR, KIT and ARID1A are associated with CNS metastasis. Conclusions: We elucidated that ctDNA mutations on PIK3CA and other genes dramatically increased in Stage IV patients compared to Stage III patients which provides a new insight on the Stage III and Stage IV MBC determination. New set of genes especially PIK3CA are identified to correlate with metastasis and affect the outcome which may also be reliably used to monitor the response to therapy.

Causal data fusion methods using summary-level statistics for a continuous outcome

In many empirical studies, there exist rich individual studies to separately estimate causal effect of the treatment or exposure variable on the outcome variable, but incomplete confounders are adjusted in each study. Suppose we are interested in the causal effect of a treatment or exposure on an outcome variable, and we have available rich datasets that contain different confounders. How to integrate summary-level statistics from multiple individual datasets to improve causal inference has become a main challenge in data fusion. We propose a novel method in this article to identify the causal effect of a treatment or exposure on the continuous outcome. We show that the causal effect is identifiable and can be estimated by combining summary-level statistics from multiple datasets containing subsets of confounders and an external dataset only containing complete confounding information. Simulation studies indicate the unbiasedness of causal effect estimate by our method and we apply our method to a study about the effect of body mass index on fasting blood glucose.

Glucuronidation and its effect on the bioactivity of amentoflavone, a biflavonoid from Ginkgo biloba leaves

OBJECTIVES

Ginkgo biloba leaves contain amentoflavone (AMF), a dietary flavonoid that possesses antioxidant and anticancer activity. Flavonoids are extensively subjected to glucuronidation. This study aimed to determine the metabolic profile of AMF and the effect of glucuronidation on AMF bioactivity.

METHODS

A pharmacokinetic study was conducted to determine the plasma concentrations of AMF and its metabolites. The metabolic profile of AMF was elucidated using different species of microsomes. The antioxidant activity of AMF metabolites was determined using DPPH/ABTS radical and nitric oxide assays. The anticancer activity of AMF metabolites was evaluated in U87MG/U251 cells.

KEY FINDINGS

Pharmacokinetic studies indicated that the oral bioavailability of AMF was 0.06 ± 0.04%, and the area under the curve of the glucuronidated AMF metabolites (410.938 ± 62.219 ng/ml h) was significantly higher than that of AMF (194.509 ± 16.915 ng/ml h). UGT1A1 and UGT1A3 greatly metabolized AMF. No significant difference was observed in the antioxidant activity between AMF and its metabolites. The anticancer activity of AMF metabolites significantly decreased.

CONCLUSIONS

A low AMF bioavailability was due to extensive glucuronidation, which was mediated by UGT1A1 and UGT1A3. Glucuronidated AMF metabolites had the same antioxidant but had a lower anticancer activity than that of AMF.

Advanced glycation end products inhibit neural stem cell differentiation via upregualtion of HDAC3 expression

Diabetes mellitus (DM) is a highly prevalent chronic systemic disease, which may cause cognitive decline and degenerative change of the brain. Neuronal differentiation defects of neural stem cells (NSCs) played an important role in the development and progression of diabetes-associated cognitive decline (DACD), but the intrinsic pathological mechanism remains largely unclear. In the present study, we demonstrated that expression level of HDAC3 was upregulated in diabetic mice with reduced learning and memory abilities and in cultured NSCs after advanced glycation end products (AGEs) induction. In addition, AGEs interfered with normal differentiation of the cultured NSCs, and knocking down the expression of HDAC3 could partially attenuate the inhibitory effect of AGEs on NSCs differentiation. Findings in this study demonstrate that HDAC3 may serve as an experimental clue for revealing the pathogenesis of DACD.

Next-generation sequencing of cerebrospinal fluid for the diagnosis of neurocysticercosis

OBJECTIVE

Neurocysticercosis (NCC) is the most common parasitic disease of the human central nervous system (CNS). However, a diagnosis of NCC may be hard to make if the specific clinical and routine neuroimaging manifestations are lacking, which hinders physicians from considering further immunodiagnostic tests.

PATIENTS AND METHODS

Seven patients presented with fever, headache, nausea, cognitive decline, confusion, or progressive leg weakness. There were no pathogens found in the cerebrospinal fluid (CSF); patients were clinically suspected of meningoencephalitis or cerebrovascular disease. To clearly determine the etiology, next generation sequencing (NGS) of the CSF was used to detect pathogens in these seven patients.

RESULTS

Taenia solium DNA sequences were detected in the seven patients, but not in the non-template controls (NTCs) or the other patients with clinically suspected CNS infections. Based on the patients' medical data and the diagnostic criteria for NCC, seven patients were diagnosed with probable NCC. The unique reads aligning to Taenia solium ranged from 6 to 261064, with genomic coverage ranging from 0.0003% to 14.8079%. The number of unique reads and genomic coverage dropped in three of the seven patients after antiparasitic treatment, consistent with the relief of symptoms.

CONCLUSION

This study showed that NGS of the CSF might be an auxiliary diagnostic method for NCC patients. Larger studies are required.

Molecular cloning and characterization of Y-box gene (Rpybx) from Manila clam and its expression analysis in different strains under low-temperature stress

Manila clam, Ruditapes philippinarum, is an economically important marine bivalve species. Y-box proteins are members of the cold shock proteins family and highly conserved from bacteria to humans. In this study, a novel Y-box gene (Rpybx) was cloned from the Manila clam and gene expression profiling was performed on three shell color strains (white, zebra and white zebra) and two wild populations (Southern and Northern) of R. philippinarum. The complete ORF length of Rpybx is 1367 bp, encoding 253 amino acids residues. Based on the amino acid sequence analysis and phylogenetic analysis, the Rpybx gene was identified as a member of the invertebrate Y-box proteins family. Rpybx has a similar tertiary structure to human Y-box protein YB-1. The Rpybx mRNA levels were analyzed by qPCR under acute and gradually varied cold stress. Under acute low-temperature stress, the expression of Rpybx mRNA in gills and hepatopancreas was significantly increased in all selected strains and populations (P < 0.05). The Northern population showed the lowest relative expression level of Rpybx. The expressions of Rpybx were greatly upregulated in gills and hepatopancreas of different stains and populations at 5 or -2°C under gradually varied temperature stress (P < 0.05). The results shed light on the biological function of the Rpybx gene in defending against low-temperature challenge and further exploring the molecular mechanism of cold tolerance and resistance in R. philippinarum.

Versatile cationic liposomes for RIP3 overexpression in colon cancer therapy and RIP3 downregulation in acute pancreatitis therapy

Because the induction of strong host antitumor responses plays a very important role in antitumor therapy, identifying effective approaches to elicit immunogenic cell death could have important implications. RIP3-dependent necroptotic cancer cells have been reported to release damage-associated molecular patterns and enhance antitumor immunity. In this study, hyaluronic acid-conjugated cationic liposomes (DOTAP/DOPE/PEG-DSPE/CHOL) (HA-P-LP) were prepared as a vector for mRIP3-pDNA overexpression in tumours. Compared with standard cationic liposomes, this vector markedly increased cellular gene internalisation in vitro, enhanced the tumour-targeting effect in vivo and exhibited a significant antitumor effect in combination with adjuvant chloroquine. Considering the dramatic increase in RIP3 under the pathological condition of pancreatitis and the correlation between pancreatitis and necroptosis, non-HA-conjugated liposomes with the same formulation loaded with shRNA mRIP3-pDNA effectively controlled the disease by decreasing the serum amylase concentration and inflammatory cell infiltration. The versatile cationic liposomes loaded with plasmids with opposing functions in this study provide a new concept and method for both tumour therapy and pancreatitis therapy.

pH-sensitive CAP/SiO2 composite for efficient co-delivery of doxorubicin and siRNA to overcome multiple drug resistance

CAP/SiO₂ composite with good biocompatibility and acid biodegradability has been prepared. The proposed drug and gene codelivery system based on it demonstrated enhanced therapeutic efficacy for multiple drug resistance cells.

Local Learning Approaches for Finding Effects of a Specified Cause and Their Causal Paths

Causal networks are used to describe and to discover causal relationships among variables and data generating mechanisms. There have been many approaches for learning a global causal network of all observed variables. In many applications, we may be interested in finding what are the effects of a specified cause variable and what are the causal paths from the cause variable to its effects. Instead of learning a global causal network, we propose several local learning approaches for finding all effects (or descendants) of the specified cause variable and the causal paths from the cause variable to some effect variable of interest. We discuss the identifiability of the effects and the causal paths from observed data and prior knowledge. For the case that the causal paths are not identifiable, our approaches try to find a path set that contains the causal paths of interest.

An Antioxidant Role by Minocycline Via Enhancing the Activation of LKB1/AMPK Signaling in the Process of Cerebral Ischemia Injury

BACKGROUND

LKB1/AMPK signaling pathway, as a metabolic checkpoint, is involved in the pathogenesis of cerebral ischemia injury. Minocycline, a tetracycline derivative, protects against cerebral ischemia via reducing inflammation, oxidative stress, and apoptosis. The aim of the study was to evaluate the influence of minocycline on oxidative biomarkers and LKB1/AMPK signaling pathway in Wistar rats with focal cerebral ischemia injury and to clarify the neuroprotective mechanism of minocycline against focal cerebral ischemia injury.

METHODS

The focal cerebral ischemia injury of Wistar rats was established by inserting a thread into the left middle cerebral artery. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to label infarct volume. The levels of MDA and LPO were measured with a biochemical assay. All other items were determined by Western blotting.

RESULTS

Minocycline decreased cerebral infarct volume, but had no effects on neurological scores. Minocycline improved the biological activity of GPx-1/2, GSS and GR, while limited the GGT1 activity in the hippocampus of cerebral ischemia-reperfusion rats. Minocycline also elevated the biological activity of SOD and counteracted lipid peroxidation. Minocycline enhanced the activity of both LKB1 and the levels of the three AMPK subunits in the hippocampus of cerebral ischemia-reperfusion rats.

CONCLUSION

Minocycline effectively inhibits oxidative stress via modulating antioxidative enzymes and activating the LKB1/AMPK signaling pathway in the process of acute cerebral infarct.

T Cell Receptor Immune Repertoires Are Promptly Reconstituted After Methicillin-Resistant Staphylococcus aureus Infection

T cells represent a subset of lymphocytes characterized by immunosurveillance and immunoregulation function. Peripheral blood mononuclear cells (PBMCs) are enriched in T cells, which exert critical antimicrobial roles in infectious diseases. High-throughput sequencing of the T cell receptor (TCR) provides deep insight into monitoring the immune microenvironment. Flow cytometry was used to analyse the distribution of αβ/γδ T cells and their CD69, IFN-γ/IL-17 expression from PBMCs. Here, we utilized next-generation sequencing (NGS) to detect the complementarity determining region 3 (CDR3) of TCRβ (TRB) and TCRδ (TRD) chain after methicillin-resistant Staphylococcus aureus (MRSA) infection. Our data demonstrated a significant increase in the activation of αβ and γδ T cells after MRSA infection. Simultaneously, significantly high CDR3 amino acid (AA) diversity and markedly reconstituted TCR immune repertoires were observed after MRSA infection. Finally, we identified several MRSA-specific initial CDR3 AA motifs after MRSA infection. Our work reveals the profiles of TRB and TRD immune repertoires in response to MRSA and demonstrates a reconstitution of the TCR immune repertoire after MRSA infection.