异常黑胆质成熟剂黄酮类化合物诱导HepG2细胞凋亡机制的研究

目的：观察异常黑胆质成熟剂中黄酮类化合物对人肝癌细胞株(HepG2)体外生长、凋亡及相关基因表达的调控作用,探讨异常黑胆质成熟剂黄酮类化合物诱导癌细胞凋亡及抗癌活性的物质基础及其作用机制。方法：采用四氮甲基唑蓝法(MTT)、琼脂糖凝胶电泳技术、流式细胞术及逆转录-多聚酶链式反应技术(RT-PCR)等,观察异常黑胆质成熟剂黄酮类化合物对HepG2生长、凋亡及凋亡基因调控的影响。结果：异常黑胆质成熟剂黄酮类化合物明显抑制HepG2细胞体外生长,HepG2细胞在sub-G₁期受到阻滞,并能诱导细胞发生凋亡,明显下调Bcl-2 mRNA表达水平,同时可上调p53,p21,Bax基因mRNA表达水平。结论：异常黑胆质成熟剂黄酮类化合物对癌细胞体外生长、凋亡及凋亡基因表达具有明显的调控作用。黄酮类化合物可能是异常黑胆质成熟剂发挥抗癌作用的主要活性成分,而抑制细胞生长、诱导细胞凋亡及调控凋亡基因表达等可能是其发挥抗癌活性的重要途径。     

Biting Innovations of Mosquito-Based Biomaterials and Medical Devices

Mosquitoes are commonly viewed as pests and deadly predators by humans. Despite this perception, investigations of their survival-based behaviors, select anatomical features, and biological composition have led to the creation of several beneficial technologies for medical applications. In this review, we briefly explore these mosquito-based innovations by discussing how unique characteristics and behaviors of mosquitoes drive the development of select biomaterials and medical devices. Mosquito-inspired microneedles have been fabricated from a variety of materials, including biocompatible metals and polymers, to mimic of the mouthparts that some mosquitoes use to bite a host with minimal injury during blood collection. The salivary components that these mosquitoes use to reduce the clotting of blood extracted during the biting process provide a rich source of anticoagulants that could potentially be integrated into blood-contacting biomaterials or administered in therapeutics to reduce the risk of thrombosis. Mosquito movement, vision, and olfaction are other behaviors that also have the potential for inspiring the development of medically relevant technologies. For instance, viscoelastic proteins that facilitate mosquito movement are being investigated for use in tissue engineering and drug delivery applications. Even the non-wetting nanostructure of a mosquito eye has inspired the creation of a robust superhydrophobic surface coating that shows promise for biomaterial and drug delivery applications. Additionally, biosensors incorporating mosquito olfactory receptors have been built to detect disease-specific volatile organic compounds. Advanced technologies derived from mosquitoes, and insects in general, form a research area that is ripe for exploration and can uncover potential in further dissecting mosquito features for the continued development of novel medical innovations.     

Effects of di(2‐ethylhexyl)phthalate on testicular oxidant/antioxidant status in selenium‐deficient and selenium‐supplemented rats

Di(ethylhexyl)phthalate (DEHP), the most widely used plasticizer, was investigated to determine whether an oxidative stress process was one of the underlying mechanisms for its testicular toxicity potential. To evaluate the effects of selenium (Se), status on the toxicity of DEHP was further objective of this study, as Se is known to play a critical role in testis and in the modulation of intracellular redox equilibrium. Se deficiency was produced in 3‐weeks‐old Sprague–Dawley rats feeding them ≤0.05 mg Se /kg diet for 5 weeks, and Se‐supplementation group was on 1 mg Se/kg diet. DEHP‐treated groups received 1000 mg/kg dose by gavage during the last 10 days of the feeding period. Activities of antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), glutathione peroxidase 4 (GPx4), thioredoxin reductase (TrxR)], catalase (CAT), superoxide dismutase (SOD), and glutathione S‐transferase (GST); concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), and thus the GSH/GSSG redox ratio; and thiobarbituric acid reactive substance (TBARS) levels were measured. DEHP was found to induce oxidative stress in rat testis, as evidenced by significant decrease in GSH/GSSG redox ratio (>10‐fold) and marked increase in TBARS levels, and its effects were more pronounced in Se‐deficient rats with ～18.5‐fold decrease in GSH/GSSG redox ratio and a significant decrease in GPx4 activity, whereas Se supplementation was protective by providing substantial elevation of redox ratio and reducing the lipid peroxidation. These findings emphasized the critical role of Se as an effective redox regulator and the importance of Se status in protecting testicular tissue from the oxidant stressor activity of DEHP. © 2011 Wiley Periodicals, Inc. Environ Toxicol 29: 98–107, 2014.     

An association study of ABCG2 rs2231142 on the concentrations of allopurinol and its metabolites

ABCG2 is a gene that codes for the human breast cancer resistance protein (BCRP). It is established that rs2231142 G>T, a single nucleotide polymorphism of the ABCG2 gene, is associated with gout and poor response to allopurinol, a uric acid‐lowering agent used to treat this condition. It has also been suggested that oxypurinol, the primary active metabolite of allopurinol, is a substrate of the BCRP. We thus hypothesized that carrying the rs2231142 variant would be associated with decreased oxypurinol concentrations, which would explain the lower reduction in uric acid. We performed a cross‐sectional study to investigate the association between the ABCG2 rs2231142 variant and oxypurinol, allopurinol, and allopurinol riboside concentrations in 459 participants from the Montreal Heart Institute Hospital Cohort. Age, sex, weight, use of diuretics, and estimated glomerular filtration rate were all significantly associated with oxypurinol plasma concentration. No association was found between rs2231142 and oxypurinol, allopurinol and allopurinol riboside plasma concentrations. Rs2231142 was not significantly associated with daily allopurinol dose in the overall population, but an association was observed in men, with T carriers receiving higher doses. Our results do not support a major role of ABCG2 in the pharmacokinetics of allopurinol or its metabolites. The underlying mechanism of the association between rs2231142 and allopurinol efficacy requires further investigation.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

ABCG2 is a gene that codes for the human BCRP. It is established that rs2231142 G>T, a single nucleotide polymorphism of the ABCG2 gene, is associated with gout and poor response to allopurinol, a uric acid‐lowering agent used to treat this condition. It is not clear if pharmacokinetic changes are involved in the underlying mechanism of those observations.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This study addressed whether the rs2231142 loss‐of‐function variant is associated with decreased oxypurinol concentrations.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Our results do not support a major role of ABCG2 in the pharmacokinetics of allopurinol or its metabolites.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Further investigations of the links between ABCG2 rs2231142 and the pharmacodynamics of allopurinol are needed.     

Preliminary study on the role of the human IZUMO gene in oocyte-spermatozoa fusion failure

We studied the IZUMO gene 9 coding exons sequence in four groups of patients including those with fertilization failure by conventional IVF. We observed in our populations two combinations of four polymorphisms that appeared to be preferentially linked (CGG-CG and TAA-TT) without any significant difference between different genotype repartitions.