Protein Kinase C-Fyn Kinase Cascade Mediates the Oleic Acid-Induced Disassembly of Neonatal Rat Cardiomyocyte Adherens Junctions

Oleic acid (OA) affects assembly of gap junctions in neonatal cardiomyocytes. Adherens junction (AJ) regulates the stability of gap junction integrity; however, the effect of OA on AJ remains largely unexplored. The distribution of N-cadherin and catenins at cell-cell junction was decreased by OA. OA induced activation of protein kinase C( PKC)-alpha and -epsilon and Src family kinase, and all three kinases were involved in the oleic acid-induced disassembly of the adherens junction, since it was blocked by pretreatment with Go6976 (a PKC alpha inhibitor), epsilon VI-2 (a PKC epsilon inhibitor), or PP2 (a Src family kinase inhibitor). Src family kinase appeared to be the downstream of PKC-alpha and -epsilon, as blockade of either PKC-alpha or -epsilon activity prevented the OA-induced activation of Src family kinase. Immunoprecipitation analyses showed that CIA activated Fyn and Fer. OA promoted the association of p120 catenin/beta-catenin with Fyn and Ferand caused increased tyrosine phosphorylation of p120 catenin and beta P- catenin, resulting in decreased binding of the former to N-cadherin and of the latter to alpha-catenin. Pretreatment with PP2 abrogated this OA- induced tyrosine phosphorylation of p120 catenin and beta-catenin and restored the association of N- cadherin with p120 catenin and that of beta -catenin with alpha-catenin. In conclusion, these results show that CA activates the PKC-Fyn signaling pathway, leading to the disassembly of the AJ. Therefore. inhibitors of PKC-alpha/- epsilon and Src family kinase are potential candidates as cardioprotection agents against OA-induced heart injury during ischemia-reperfusion

Revision in Reference Ranges of Peripheral Total Leukocyte Count and Differential Leukocyte Percentages Based on a Normal Serum C-Reactive Protein Level

A higher total leukocyte count is a predictor of all-cause mortality and cardiovascular morbidity. The currently used reference range for peripheral total leukocyte count is wide (4.5–11.0 × 109/L) and is associated with a low sensitivity in identifying non-infectious chronic diseases. We attempt to revise it based on a normal serum C-reactive protein (CRP) level. Methods: Study subjects were participants in a health check program at our hospital between 2000 and 2002. Those whose leukocyte analysis had been checked with the Sysmex Cell Counter NE-9000 were enrolled. Results: Significantly positive relationships between CRP level and total leukocyte count, neutrophil percentage, and monocyte percentage were found in all subjects (n = 14,114; p< 0.0001). In contrast, CRP level had a significantly inverse correlation with lymphocyte percentage (p < 0.0001). A proposed new reference range for total leukocyte count was estimated based on the data in the normal CRP level group (CRP < 0.1 mg/dL; n = 4839). To rest on the essence of statistics that the range of [mean ± 2 standard deviations] contains approximately the middle 95% of observations in a sampled population, a new reference range for total leukocyte count was accordingly estimated to be 3.11–8.83 × 109/L. Conclusion: In view of the abundant evidence showing that a higher peripheral total leukocyte count is harmful to health, a down-correction of its upper reference range from the currently used 11.0 × 109/L to the proposed 8.83 × 109/L, based on a normal CRP level, should allow more abnormal health conditions to be identified and promote the usefulness of peripheral leukocyte analysis

Aminoguanidine prevents age-related deterioration in left ventricular–arterial coupling in Fisher 344 rats

1. In recent studies, aminoguanidine (AG), an inhibitor of advanced glycation endproducts, has been identified as a prominent agent that can prevent the age-related aortic stiffening and cardiac hypertrophy. The aim of this study was to determine whether AG had effects on the left ventricular (LV)–arterial coupling in aged Fisher 344 rats in terms of the ventricular and arterial chamber properties. 2. Normotensive rats were treated from 18 to 24 months with AG (1 g l(−1) in drinking water) and compared with a control group. LV pressure and ascending aortic flow signals were recorded to construct the ventricular and arterial end-systolic pressure–stroke volume relationships to calculate LV end-systolic elastance (E(es)) and effective arterial volume elastance (E(a)), respectively. The optimal afterload (Q(load)) determined by the ratio of E(a) to E(es) was used to measure the efficiency of mechanical energy transferred from the left ventricle to the arterial system. 3. In comparison with the 6-month-old rats, the 24-month-old animals had decreased E(es), at 567.4±26.7 vs 639.0±20.7 mmHg ml(−1), decreased E(a), at 411.5±18.6 vs 577.9±15.7 mmHg ml(−1), and decreased Q(load), at 0.9428±0.0024 vs 0.9962±0.0014. 4. Treatment with AG for 6 months did not significantly affect E(es); however, when normalized to LV weight (i.e., E(esn)=E(es)/LV weight), E(esn) showed a significant rise of 22.8%, suggesting that AG may retard the aging process on the intrinsic contractility of the left ventricle. On the other hand, the decrease in E(a) in aging rats was prevented by AG, as reflected in the increase of 19.7% in this variable (P<0.05). The 24-month-old treated rats also exhibited a significant rise of 21.6% in E(a)/E(es), causing an increase of 5.2% in Q(load) (P<0.05). 5. We conclude that in healthy older Fisher 344 rats without diabetes, long-term treatment with AG may improve both the arterial and ventricular function and optimize the matching condition for the left ventricular–arterial coupling

Regulation of Epstein-Barr Virus Minor Capsid Protein BORF1 by TRIM5α

TRIM5α is a host anti-retroviral restriction factor that destroys human immunodeficiency virus (HIV) virions and triggers innate immune signaling. TRIM5α also mediates the autophagic degradation of target proteins via TRIMosome formation. We previously showed that TRIM5α promotes Epstein-Barr virus (EBV) Rta ubiquitination and attenuates EBV lytic progression. In this study, we sought to elucidate whether TRIM5α can interact with and induce the degradation of EBV capsid proteins. Glutathione S-transferase (GST) pulldown and immunoprecipitation assays were conducted to identify interacting proteins, and mutants were generated to investigate key binding domains and ubiquitination sites. Results showed that TRIM5α binds directly with BORF1, an EBV capsid protein with a nuclear localization signal (NLS) that enables the transport of EBV capsid proteins into the host nucleus to facilitate capsid assembly. TRIM5α promotes BORF1 ubiquitination, which requires the surface patch region in the TRIM5α PRY/SPRY domain. TRIM5α expression also decreases the stability of BORF1(6KR), a mutant with all lysine residues mutated to arginine. However, chloroquine treatment restores the stability of BORF1(6KR), suggesting that TRIM5α destabilizes BORF1 via direct recognition of its substrate for autophagic degradation. These results reveal novel insights into the antiviral impact of TRIM5α beyond retroviruses

Effect of Physical Activity on the Prevalence of Metabolic Syndrome and Left Ventricular Hypertrophy in Apparently Healthy Adults

Metabolic syndrome and left ventricular hypertrophy (LVH) carry high cardiovascular risks. We performed a cross-sectional study to evaluate the effect of different amounts of physical activity (PA) on the prevalence of metabolic syndrome and LVH in our study population. Methods: This study was a cross-sectional survey of 1494 apparently healthy subjects: 776 men with a mean age of 57.6 + 12.3 years, and 718 women with a mean age of 56.4+ 11.0 years. The metabolic syndrome was defined according to modified criteria of the National Cholesterol Education Program Adult Treatment Panel III. LVH was diagnosed by electrocardiography voltage criteria. The amount of PA was determined with a questionnaire and stratified into low, moderate or high levels. Results: The prevalence of metabolic syndrome and its components was as follows: metabolic syndrome, 15.5%; obesity, 29.7%; high triglyceride level, 21.7%; low high-density lipoprotein-cholesterol level, 35.9%; high blood pressure, 56.9%; and impaired fasting glucose, 13.1%. A high amount of PA (> 14km per week walking distance) was significantly associated with lower prevalence of metabolic syndrome [odds ratio (OR) = 0.53, p = 0.001], lower prevalence of obesity (OR = 0.56, p = 0.001), triglyceridemia (OR = 0.58, p = 0.007) and LVH (OR=0.37, p = 0.006). Conclusion: This study suggests that high amounts of PA are inversely correlated with the prevalence of metabolic syndrome and LVH in men and women

Human C-reactive Protein (CRP) Gene 1059 G > C Polymorphism is Associated with Plasma CRP Concentration in Patients Receiving Coronary Angiography

Elevation of C-reactive protein (CRP) level is associated with increased risk of cardiovascular events. The 1059 G > C polymorphism in exon 2 of the CRP gene has been shown to affect plasma concentration of CRP. We want to elucidate the effect of this polymorphism on the development of coronary artery disease (CAD) among the Chinese population in Taiwan. Methods: We scrutinized 536 patients undergoing coronary angiography (365 patients with CAD and 171 controls with patent coronaries) and evaluated the association of CRP gene 1059 G > C polymorphism with CAD. Genotyping of the polymorphism was performed by polymerase chain reaction and MaeIII restriction enzyme digestion. Results: The CC genotype was associated with lower plasma CRP concentration (GG, 6.5 ± 5.8; GC, 3.3 ± 4.4; CC, 2.3 ± 3.1 mg/L; p = 0.02). Subjects with CAD or myocardial infarction (MI) had significantly higher plasma CRP concentration than that in controls (CAD vs. controls, 8.9 ± 18.9 vs. 3.3 ± 7.2 mg/L; p < 0.001), while patients with MI showed higher CRP when compared to those with chronic stable angina (13.5 ± 22.9 vs. 5.2 ± 14.1 mg/L; p < 0.001). However, this polymorphism was not associated with CAD in our population. Conclusion: Our data suggest that human CRP gene 1059 G > C polymorphism is associated with plasma CRP concentration among Chinese in Taiwan receiving coronary angiography