Rapid analysis of fatty acid-binding proteins with immunosensors and immunotests for early monitoring of tissue injury

Fatty acid-binding protein (FABP) holds promise for early detection of tissue injury. This small protein (15 kD) appears earlier in the blood than large proteins after cell damage. Combined its characteristics of high concentration tissue contents and low normal plasma values provide the possibility of a rapid rise above the respective reference values, and thus an early indication of the appearance of tissue injury. A general review was presented on the current status of different types of FABP for the detection of tissue injury in patients with myocardial injury, brain injury and also in athletes or horses with skeletal muscle injury.

To take full advantage of the characteristics of the early marker FABP, rapid analysis is a crucial parameter. In this review, an overview of the development of immunoassay for the quantification of FABP in buffer, plasma or whole blood was outlined. The characteristics of different FABP immunosensors and immunotests were described. The feasibility of these immunoassays to be used in routine clinical practice and in emergency case was also discussed.

Nowadays, the improved automated immunoassays (e.g. a microparticle-enhanced turbidimetric immunoassay), less time-consuming bedside immunosensors and immunotests (e.g. a one-step FABP lateral flow immunotest), are the main advance technology in point-of-care testing. With these point-of-care tests, the application of FABP as an early tissue injury marker has a great potential for many clinical purposes.     

Single nucleotide polymorphism in CPT1B and CPT2 genes and its association with blood carnitine levels in acute myocardial infarction patients

Ischemic and reperfusion injuries in acute myocardial infarction (AMI) lead to mitochondrial dysfunction in heart cells. Lipid metabolism takes place in mitochondria where carnitine palmitoyltransferase (CPT) enzyme system facilitates the transport of long-chain fatty acids into matrix to provide substrates for beta-oxidation. We sequenced the coding regions of CPT1B and CPT2 genes to identify the single nucleotide polymorphism (SNP) in 23 AMI patients and 23 normal subjects. We also determined blood carnitine levels in these samples to study the impact of these SNPs on carnitine homeostasis. The sequencing of coding regions revealed 4 novel variants in CPT1B gene (G320D, S427C, E531K, and A627E) and 2 variants in CPT2 gene (V368I and M647V). There were significant increases in total carnitine (54.18 ± 3.11 versus 21.49 ± 1.03 μmol/l) and free carnitine (37.78 ± 1.87 versus 10.06 ± 0.80 μmol/l) levels in AMI patients as compared to normal subjects. CPT1B heterozygous variants of G320D and S427C among control subjects showed significantly higher levels of total and free carnitine in the blood. The homozygous genotype (AA) of CPT2 variant V368I had significantly less blood carnitine in AMI patients. Serum troponin T was significantly less in GG genotype of CPT1B variant S427C whereas the genotype AA of CPT2 variant V368I showed significantly higher serum troponin T levels. Further studies on large number of patients are necessary to confirm the role of CPT1B and CPT2 polymorphism in AMI.     

Further evidence for the contribution of the vascular endothelial growth factor gene in coronary artery disease susceptibility

Coronary artery disease (CAD) receives intensive attentions in the research of cardiovascular diseases, due to its high incidence and severe impact on the quality of life vascular endothelial growth factor (VEGF), a potent angiogenic and vascular permeability factor, has been strongly implicated in the pathogenesis of CAD. Genetic markers in different regions of the VEGF gene have a plausible role in modulating the risk of CAD. To identify the markers contributing to the genetic susceptibility to CAD, we examined the potential association between CAD and 10 single nucleotide polymorphisms (SNPs, rs699947, rs1570360, rs2010963, rs833068, rs3024997, rs3025000, rs3025010, rs3025020, rs3025030, rs3025039) of the VEGF gene using the MassARRAY system. Participants included 242 CAD patients and 253 healthy controls from a Chinese Han Population (He'nan Province, China). The allelic or genotypic frequencies of the rs699947 (5′ untranslated regions, 5′UTR) and rs2010963 (5′UTR) polymorphisms in the CAD patients were significantly different from those in the healthy controls. The CAD patients had significantly higher frequency of the rs699947 A allele (χ² = 11.141, P = 0.001, OR = 1.665, 95% CI = 1.232–2.250) and rs2010963 C allele (χ² = 13.593, P = 0.0002, OR = 1.611, 95% CI = 1.249–2.077). Strong linkage disequilibrium was observed in the rs699947–rs1570360–rs2010963 haplotype block (D’ > 0.9). Significantly more C–G–C haplotypes (P = 0.040) and significantly fewer C–G–G haplotypes (P = 0.0004) were found in the CAD patients. The possible association of rs699947 and rs2010963 with CAD risks warrant confirmation in independent case–control studies and may be informative for future investigations on the pathogenesis of CAD.     

Antioxidant activity contributes to flavonol cardioprotection during reperfusion of rat hearts

The mechanism of flavonol-induced cardioprotection is unclear. We compared the protective actions of a flavonol that inhibits calcium utilization and has antioxidant activity, 3′,4′-dihydroxyflavonol (DiOHF); a flavonol that affects only calcium activity, 4′-OH-3′-OCH₃-flavonol (4′-OH-3′-OCH₃F); and a water-soluble flavonol with selective antioxidant activity, DiOHF-6-succinamic acid (DiOHF-6-SA), in isolated, perfused rat hearts. Hearts were subjected to global ischemia for 20 min followed by 30 min reperfusion and were treated with vehicle (0.05% DMSO), DiOHF, 4′-OH-3′-OCH₃F, or DiOHF-6-SA (all 10 μM, n = 5-8 per group). Flavonols were infused for 10 min before ischemia and during reperfusion. In vehicle-treated hearts, left-ventricular (LV) + dP/dt was reduced by 60% at the end of reperfusion compared to the preischemic level. Lactate dehydrogenase (LDH) release was elevated and endothelial NO synthase (eNOS) expression was lower in vehicle-treated hearts compared to shams. In comparison, DiOHF treatment improved LV function upon reperfusion, decreased LDH, and preserved eNOS expression. The antioxidant DiOHF-6-SA also preserved contractility, reduced LDH, and preserved eNOS expression. In contrast, hearts treated with 4′-OH-3′-OCH₃F showed a degree of contractile impairment similar to that of the vehicle group. DiOHF and DiOHF-6-SA also exerted cardioprotection when given only during reperfusion and not when administered only before ischemia. Flavonol-induced cardioprotection relies on antioxidant activity and is mainly exerted during reperfusion.     

不同性别急性心肌梗死合并心衰患者院内治疗及一年随访情况的比较

目的:比较不同性别急性心肌梗死(Acute Myocardial Infarction,AMI)合并心衰患者住院期间院内治疗方式、一年随访用药依从性及心血管不良事件发生情况。方法:收集我院2014年10月至2015年6月收治的136例急性心肌梗死合并心衰患者,分析和比较不同性别患者入院时的临床特征、住院期间治疗方式、一年随访过程中用药依从性以及心血管不良事件发生率的差异。结果:本研究共入组136例急性心肌梗死合并心衰患者,其中男性患者70(51.47%)例,女性66(48.53%)例。男性患者具有吸烟史、饮酒史的比例显著高于女性患者(62.86%vs 28.79%,P=0.001;35.71%vs 10.61%,P=0.001),但具有糖尿病史的比例明显低于女性(35.71%vs 53.03%,P=0.042);男性患者住院期间接受溶栓或经皮冠状动脉介入(Percutaneous Coronary Intervention,PCI)治疗的比例明显高于女性(62.86%vs 45.45%,P=0.042);男性患者一年随访期间出现胸痛、卒中的比例低于女性(11.43%vs 24.24%,P=0.050;2.86%vs 12.12%,P=0.050);但出血事件的发生率高于女性(10.00%vs 0%,P=0.014)。结论:男性急性心肌梗死合并心衰患者住院期间接受溶栓或PCI治疗的比例明显高于女性;一年随访过程中出现胸痛、卒中事件率低于女性,但出血事件的发生率高于女性。     

CK-MB特异性单抗的制备方法及其应用

本研究拟建立肌酸激酶同工酶MB(CK-MB)特异性单克隆抗体(m Ab)的研制方法,对抗CK-MB单抗进行评价分类及性质鉴定,并初步建立CK-MB定量检测试剂。以CK-MB抗原免疫BALB/c小鼠,利用常规单抗制备技术,使用间接和捕获ELISA差异筛选法筛选单抗。利用肌酸激酶同工酶(CK-MM/BB/MB)抗原对所制备单抗的抗原识别表位进行鉴定,另通过免疫印迹法及合成CK-MM、CK-BB差异性的线性表位肽鉴定对所制备的单抗进行评价分类。使用双抗体夹心ELISA方法筛选检测CK-MB抗原的配对m Ab,并初步建立CK-MB定量检测试剂。使用74例临床标本初步评价该试剂与罗氏试剂的检测一致性。最终,我们成功筛选到22株稳定分泌抗CK-MB抗体的杂交瘤细胞株,这些单抗可以分为线性、偏构象的CK-MB和CK-MM或者CK-BB交叉的单抗以及与CK-MB特异反应的偏构象型单抗,并使用偏构象型单抗研制出CK-MB定量检测试剂,该试剂与罗氏试剂相关系数r达到0.930 9。综上所述,本研究建立了研制CK-MB偏构象型特异性单抗的筛选方法,通过对所筛选的单抗进行分析鉴定并建立了CK-MB定量检测试剂,与罗氏试剂检测结果符合率高。     

Tricyclic antidepressants exhibit variable pharmacological profiles at the α2A adrenergic receptor

Antidepressant mechanisms of action remain shrouded in mystery, greatly hindering our ability to develop therapeutics which can fully treat patients suffering from depressive disorders. In an attempt to shed new light on this topic, we have undertaken a series of studies investigating actions of tricyclic antidepressant drugs (TCAs) at the α_2A adrenergic receptor (AR), a centrally important receptor, dysregulation of which has been linked to depression. Our previous work established a particular TCA, desipramine, as an arrestin-biased α_2AAR ligand driving receptor endocytosis and downregulation but not canonical heterotrimeric G protein-mediated signaling. The present work is aimed at broadening our understanding of how members of the TCA drug class act at the α_2AAR, as we have selected the closely related but subtly different TCAs imipramine and amitriptyline for evaluation. Our data demonstrate that these drugs do also function as direct arrestin-biased α_2AAR ligands. However, these data reveal differences in receptor affinity and in the extent/nature of arrestin recruitment to and endocytosis of α_2AARs. Specifically, amitriptyline exhibits an approximately 14-fold stronger interaction with the receptor, is a weaker driver of arrestin recruitment, and preferentially recruits a different arrestin subtype. Extent of endocytosis is similar for all TCAs studied so far, and occurs in an arrestin-dependent manner, although imipramine uniquely retains a slight ability to drive α_2AAR endocytosis in arrestin-null cells. These findings signify an important expansion of our mechanistic understanding of antidepressant pharmacology, and provide useful insights for future medicinal chemistry efforts.     

Synergistic effect of anti and pro-inflammatory cytokine genes and their promoter polymorphism with ST-elevation of myocardial infarction

Background

The single-gene approach in association studies of polygenic diseases such as acute myocardial infarction (AMI) is likely to provide limited value. Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) plasma levels may be genetically influenced.

Aim

We evaluate the impact of single nucleotide polymorphism of the promoter region of these genes, as well as reciprocal interaction of these genes with ST-elevation of myocardial infarction (STEMI).

Methods

In a case–control study 500 STEMI patients and 500 age- and sex-matched controls were studied. Three single-nucleotide polymorphism genotypes were evaluated by polymerase chain reaction and restriction enzyme analysis and assessed their association with STEMI. The synergistic effects of IL-6, TNF-α and IL-10 gene polymorphisms were evaluated by using logistic regression analysis.

Results

We found that IL-6 and TNF-α concentrations of studied population were significantly different (p < 0.0001) in each genotype of IL-6 − 174G>C and TNF-α − 308G>A gene polymorphisms respectively. A significant association was found in multivariate analysis for the IL-6 − 174G>C [odds ratio (OR): 0.390; 95% confidence interval (CI): 0.176–0.865, p = 0.020] and TNF-α − 308G>A [OR: 0.372; 95% CI: 0.171–808, p = 0.012] gene polymorphisms with STEMI. In contrast, IL-10 − 592C>A gene polymorphism was no longer significant in the multivariate model (OR: 0.678; 95% CI: 0.288 to 1.594, p = 0.373) whereas significant in univariate analysis (OR: 0.697; 95% CI: 0.523–0.929, p = 0.014).

Conclusions

Our findings suggest that IL-6, TNF-α and IL-10 gene polymorphisms all contribute in the association with STEMI whereas the association persisted only for IL-6 and TNF-α but not for IL-10 gene polymorphism with this disease in the multivariate analysis.