Advances in histone epigenetic enzyme inhibitors based on proteomics / 药学学报

As an important component of nucleosomes on the chromatin of eukaryotic cells, histones play an important role in the development and progression of tumour diseases by regulating epigenetic post-translational modifications such as acetylation and methylation. In addition, development of inhibitors targeting methyltransferase and deacetylase provides novel therapeutic strategies for cancer treatment. Mass spectrometry-based proteomics can reveal the global changes of histone modifications under the action of drugs during disease progression, which in turn provides important support for revealing drug action mechanism, drug resistance mechanism, and investigating novel drug combination strategies. This article focuses on the progress and status of proteomic research on a variety of histone modifying enzyme inhibitors, including methyltransferase inhibitors and histone deacetylase inhibitors, which will help to understand the current and further utilization of proteomics in studying histone modifications.

Functional Investigation of a GRIN2A Variant Associated with Rolandic Epilepsy / 神经科学通报·英文版

N-methyl-D-aspartate receptors (NMDARs), a subtype of glutamate-gated ion channels, play a central role in epileptogenesis. Recent studies have identified an increasing number of GRIN2A (a gene encoding the NMDAR GluN2A subunit) mutations in patients with epilepsy. Phenotypes of GRIN2A mutations include epilepsy-aphasia disorders and other epileptic encephalopathies, which pose challenges in clinical treatment. Here we identified a heterozygous GRIN2A mutation (c.1341T>A, p.N447K) from a boy with Rolandic epilepsy by whole-exome sequencing. The patient became seizure-free with a combination of valproate and lamotrigine. Functional investigation was carried out using recombinant NMDARs containing a GluN2A-N447K mutant that is located in the ligand-binding domain of the GluN2A subunit. Whole-cell current recordings in HEK 293T cells revealed that the N447K mutation increased the NMDAR current density by ~1.2-fold, enhanced the glutamate potency by 2-fold, and reduced the sensitivity to Mg inhibition. These results indicated that N447K is a gain-of-function mutation. Interestingly, alternative substitutions by alanine and glutamic acid at the same residue (N447A and N447E) did not change NMDAR function, suggesting a residual dependence of this mutation in altering NMDAR function. Taken together, this study identified human GluN2A N447K as a novel mutation associated with epilepsy and validated its functional consequences in vitro. Identification of this mutation is also helpful for advancing our understanding of the role of NMDARs in epilepsy and provides new insights for precision therapeutics in epilepsy.

Influence of genetic polymorphisms in drug metabolism enzymes and transporters on pharmacokinetics of different fluvastatin formulations / 中国药理学与毒理学杂志

OBJECTIVE The purpose of the present study was to investigate the impact of fluvas-tatin formulation on the pharmacokinetics-genetic polymorphis relationship. METHODS We compared the difference between the pharmacokinetics of fluvastatin as an extended-release (ER) 80 mg tablet and an immediate-release(IR)40 mg capsule in terms of drug metabolism enzyme and transporter ge-netic polymorphisms. In this open-label, randomized, two-period, two-treatment, crossover study, ef-fects of BCRP, SLCO1B1, MDR1, CYP2C9, and CYP3A5 polymorphisms on the pharmacokinetics of fluvastatin were analyzed in 24 healthy individuals.Each treatment duration was 7 days with a washout period of 7 days between the crossover.Serum concentration of fluvastatin was evaluated using high-performance liquid chromatography-tandem mass spectrometry. RESULTS The SLCO1B1 T521C genotype had no statistically significant effect on IR 40 mg capsule of fluvastatinafter single or repeated doses.However,for the ER 80 mg tablet,the SLCO1B1 T521C genotype correlated with the AUC0-24of repeat doses (P=0.01). The CYP2C9*3 genotype correlated with the AUC0- 24after the first dose IR 40 mg capsule (P<0.05); however, the difference between CYP2C9*1/*1 and CYP2C9*1/*3 was not statistically significant after repeated doses. CONCLUSION The effect of SLCO1B1 T521C on fluvas-tatin exposure was observed and was more profound in ER and repeated dose administration than in IR and single dose administration.We recommend that formulation should be incorporated into future pharmacogenomics studies and clinical implication guidelines.

Research progress of mitophagy in ophthalmic related diseases / 国际眼科杂志(Guoji Yanke Zazhi)

·Mitophagy is a selective autophagy refers to the autophagy process by which cells selectively remove mitochondria. Mitophagy plays important roles in clearing up dysfunctional mitochondria, reducing mitochondrial numbers and maintaining cell homeostasis. Its molecular mechanisms involve several proteins such as PINK1/Parkin, BNIP3, NIX, and FUNDC1. Mitochondrial dysfunction or damage may cause serious consequences, and may even lead to cell death. Studies have shown that disfunction of mitophagy is related to many eye diseases, for instance, cataract, glaucoma, age-related macular degeneration,diabetic retinopathy,etc. This review deals with the mechanisms of mitophagy and its research on ocular diseases.

A review on the current neuroligin mouse models / 生理学报

Neuroligins (NLs) are postsynaptic membrane proteins expressed in the brain and mediate synaptogenesis. Neuroligin family proteins can specifically induce either excitatory or inhibitory synapses. Deletions or point mutations in neuroligin genes are found in patients with autism spectrum disorders (ASD) or mental retardations. The dysfunctions of these mutations have been tested in multiple neuroligin mouse models. In most of the models, including the human autism-linked NL3 and NL4 mutation mice, there are social interaction defects, memory impairment and repetitive behaviors. Researchers also found the excitatory/inhibitory synapse ratio altered in those mice, as well as receptor subunit composition. However, inconsistencies and debates also exist between different research approaches. In this review, we summarize the neuroligin mouse models currently available, examine the detailed alterations detected in those mice and compare the differences within different mouse models or different investigation methods, to obtain an overall picture of the current progress on neuroligin mouse models.

Studies on solid phase extraction method of aristolochic acids and aristololactams in rat urine / 中国中药杂志

<p><b>OBJECTIVE</b>To develop a urine pretreatment method of Solid Phase Extraction (SPE) for the quantitative determination of a number of aristolochic acids (AAs) and aristololactams (ALs) in rat urine.</p><p><b>METHOD</b>The HPLC peak area of AA-I , AA-II, AL-I and AL-II, and other sixteen AAs and ALs was chosen as evaluating index to study the extract results of five Solid Phase Extraction columns (Agilent C18/100 mg, Alltech HG18/100 mg, Alltech C18/100 mg, Alltech C18/300 mg and Agilent Phenyl/200 mg) comparatively. The influences of two washing solvents (water and 1% acetic acid-0.02% triethylamine solution) and seven eluting solvents (ether, acetone, chloroform, ethyl acetate, dichloromethane, methanol and acetonitrile) on extract results of AAs and ALs are comparatively studied with the extracting recoveries of AA-I , AA-II, AL-I and AL-II as indicators. The HPLC peak area of AA-I , AA-II, AL-I and AL-II, and other seven AAs and ALs with good separation being targets, several factors which affect extracting efficiency of analytes, including activating volume, cleansing volume, washing volume and eluting volume, are optimized by orthogonal design experiments with four factors at three levels.</p><p><b>RESULT</b>The established method of SPE is as follows: Agilent Phenyl SPE column of 200 mg, activating with 1.0 mL methanol, cleansing with 1 mL water, adding 1.0 mL rat urine sample, washing with 0.8 mL 1% acetic acid 0.02% triethylamine solution, and eluting with 3.0 mL methanol.</p><p><b>CONCLUSION</b>The established method of SPE is efficient, selective, simple and fast, and can be used as urine pretreatment method to analyze a variety of aristolochic acids and aristololactams in rat urine.</p>

Affection of different preparations on the content of toxic constituents in traditional Chinese medicines, examplified with Caulis Aristolochiae Manshuriensis / 中国中药杂志

<p><b>OBJECTIVE</b>Taking Caulis Aristolochiae Manshuriensis (Guanmutong in Chinese, derived from the stem of Aristolochia manshuriensis) as an example, to study the affection of different preparations on the content of toxic constituents in traditional Chinese medicines.</p><p><b>METHOD</b>The separation was performed on a zorbax SB-C18 column with mobile phase of acetonitrile-3.7 mmol x L(-1) phosphoric acid buffer, detected at 260 nm.</p><p><b>RESULT</b>The extraction percentage of aristolochic acids I, II and IV a in water extraction (1 h x 2) of Guanmutong were 53.4%, 75.5% and 61.9%, respectively; the remaining quantity of aristolochic acids I, II and IVa in the dregs of the decoction were 22.3%, 15.7% and 30.3%, respectively; Aristolochic acid I was still main substance among these aristolohic acids in the decoction of Guanmutong.</p><p><b>CONCLUSION</b>The content of toxic constituents of the traditional Chinese medicines varies evidently with different preparations of Guanmutong. So the preparation methods of traditional Chinese medicines should be suitably selected according to characteristics of the toxic constituents so as to lessen the body damages of human.</p>