Novel Antiviral Activity of Ethyl 3-Hydroxyhexanoate Against Coxsackievirus B Infection

Coxsackievirus group B (CVB) is a member of the genus Enterovirus in the family Picornaviridae. CVB infection has been implicated as a major etiologic agent of viral myocarditis, dilated cardiomyopathy, meningitis, and pancreatitis among children and young adults. Until date, no antiviral agent has been licensed for the treatment of Coxsackievirus infection. In an effort to identify antiviral agents against diseases caused by the CVB, we found that ethyl 3-hydroxyhexanoate (EHX), a volatile compound present in fruits and food additives, is a potent antiviral compound. In this study, we demonstrated that EHX treatment significantly inhibits CVB replication both in vivo and in vitro. Furthermore, EHX possesses antiviral activity at 50% effective concentration (EC₅₀) of 1.2 μM and 50% cytotoxicity (CC₅₀) of 25.6 μM, yielding a selective index (SI) value as high as 20.8. Insights into the mechanism of antiviral activity of EHX showed that it acts at the step of viral RNA replication. Since EHX has received approval as food additives, treatment of CVB-related infections with EHX might be a safe therapeutic option and may be a promising strategy for the development of semi-synthetic antiviral drugs for viral diseases.

Functional Annotation of Hypothetical Proteins related to Antibiotic Resistance in Pseudomonas Aeruginosa PA01

BACKGROUND

Pseudomonas aeruginosa is a Gram-negative bacteria that causes a large range of human infections such as lung infection (cystic fibrosis) and urinary tract infection. Even worse, antibiotic resistant bacteria have become a serious health care problem throughout the last decade, and there is a need for a clear approach to regulate and prevent the spread of pseudomonas aeruginosa resistance.

METHODS

A complete analysis of Pseudomonas aeruginosa proteomics data showed that 25% of proteins are hypothetical proteins (HPs) whose function is not precisely defined. HP gene sequence analysis offers a framework for defining sequence-function relationships with a deeper understanding of organisms' molecular mechanisms at the system level. In the current research, we used the power of different bioinformatics tools to assign the potential roles for the HPs based on protein family association, amino acid function, motifs, and pathway analysis.

RESULTS

The current findings show that 30 HPs have well-defined functions and are classified as enzymes, DNA binding, periplasmic binding protein, transport, etc. Seven HPs showed virulence characteristics that is to be expected to be essential for Pseudomonas aeruginosa and pathogenesis survival.

CONCLUSIONS

This study's findings may encourage a better understanding of virulence mechanisms, drug resistance, pathogenesis, and drug discovery to treat Pseudomonas aeruginosa infections.

Irradiation resistance mechanism of the CoCrFeMnNi equiatomic high-entropy alloy

When face-centered cubic (FCC) metals and alloys with low stacking fault energy (SFE) are irradiated by high-energy particles or deformed at high speed, stacking fault tetrahedra (SFTs), which are a type of vacancy cluster defect, are often formed. Therefore, SFTs were expected to form in the CoCrFeMnNi equiatomic high-entropy alloy (HEA). However, no SFT was observed in the CoCrFeMnNi HEA with high-speed plastic deformation even after annealing at 873 K. To elucidate this mechanism, the binding energy of vacancy clusters in the CoCrFeMnNi HEA was calculated based on first principles. The binding energy of the di-vacancy cluster was positive (average of 0.25 eV), while that of the tri-vacancy cluster was negative (average of - 0.44 eV), suggesting that the possibility of formation of a tri-vacancy cluster was low. The inability to form a cluster containing three vacancies is attributed to the excellent irradiation resistance of the CoCrFeMnNi HEA. However, if an extra vacancy is added to a tri-vacancy cluster (with negative binding energy), the binding energy of the subsequent tetra-vacancy cluster may become positive. This suggests that it is possible to form vacancy clusters in the CoCrFeMnNi HEA when high-energy ion or neutron irradiation causes cascade damage.

Effects of the HIF-1α and NF-κB loop on epithelial-mesenchymal transition and chemoresistance induced by hypoxia in pancreatic cancer cells

Hypoxia is a microenvironmental factor which plays a critical role in tumor development and chemoresistance. Epithelial-to-mesenchymal transition (EMT) induced by hypoxia is one of the critical causes of treatment failure and chemoresistance in different types of human cancers. Stabilization of the hypoxia-inducible factor-1α (HIF-1α) transcription complex, caused by intratumoral hypoxia, promotes tumor progression and chemoresistance. Previous evidence suggests that hypoxia can also activate nuclear factor-κB (NF-κB), a known mediator of EMT, which is accompanied by reduced expression of epithelial marker E-cadherin and enhanced expression of the mesenchymal markers Vimentin and N-cadherin as well as overexpression of various transcription factors of EMT, such as Snail and Twist. Based on this evidence, the present study aimed to investigate whether downregulation of the p65 subunit of NF-κB or HIF-1α by small interfering RNA (siRNA) may reverse the EMT phenotype and inhibit the proliferation and induce the apoptosis of pancreatic cancer cell lines (PANC-1, BxPC3) under hypoxic conditions in vitro and enhance the efficacy of gemcitabine in the treatment of pancreatic cancer. These results provide molecular evidence showing that the activation of the HIF-1α and NF-κB loop is mechanistically linked with the chemoresistance phenotype (EMT phenotype) of pancreatic cancer cells under hypoxic conditions, suggesting that the inactivation of HIF-1α and NF-κB signaling by novel strategies may be a potential targeted therapeutic approach for overcoming EMT and chemoresistance induced by hypoxia.

Absence of SOCS3 in the cardiomyocyte increases mortality in a gp130-dependent manner accompanied by contractile dysfunction and ventricular arrhythmias

BACKGROUND

Suppressor of cytokine signaling-3 (SOCS3) is a key negative-feedback regulator of the gp130 receptor that provides crucial signaling for cardiac hypertrophy and survival; however, an in vivo role of SOCS3 regulation on cardiac gp130 signaling remains obscure.

METHODS AND RESULTS

We generated cardiac-specific SOCS3 knockout (SOCS3 cKO) mice. These mice showed increased activation of gp130 downstream signaling targets (STAT3, ERK1/2, AKT, and p38) from 15 weeks of age and developed cardiac dysfunction from approximately 25 weeks of age with signs of heart failure. Surprisingly, SOCS3 cKO failing hearts had minimal histological abnormalities with intact myofibril ultrastructure. In addition, Ca(2+) transients were significantly increased in SOCS3 cKO failing hearts compared with wild-type hearts. We also found that Ser23/24 residues of troponin I were hypophosphorylated in SOCS3 cKO hearts before the manifestation of cardiac dysfunction. These data suggested the presence of abnormalities in myofilament Ca(2+) sensitivity in SOCS3 cKO mice. In addition to the contractile dysfunction, we found various ventricular arrhythmias in SOCS3 cKO nonfailing hearts accompanied by a sarcoplasmic reticulum Ca(2+) overload. To determine the contribution of gp130 signaling to the cardiac phenotype that occurs with SOCS3 deficiency, we generated cardiac-specific gp130 and SOCS3 double KO mice. Double KO mice lived significantly longer and had different histological abnormalities when compared with SOCS3 cKO mice, thus demonstrating the importance of gp130 signaling in the SOCS3 cKO cardiac phenotype.

CONCLUSIONS

Our results demonstrate an important role of SOCS3 regulation on cardiac gp130 signaling in the pathogenesis of contractile dysfunction and ventricular arrhythmias.

Efficacy of c-erbB-2 antisense oligonucleotide transfection on uterine endometrial cancer HEC-1A cell lines

OBJECTIVE

Antigene therapy targeting only one oncogene has made much progress although it still has some limitations. To explore the potential for antigene therapy in uterine endometrial cancer, we examined the in vitro inhibitory effects of liposmal anti-sense phosphorothioate oligonucleotides targeting c-erbB-2 in the human uterine endometrial cancer HEC-1A cell line.

METHODS

1) To detect c-erbB-2 protein expression on HEC-1A cell membranes by immunohisto- chemistry. 2) To assay cellular growth inhibition by MTT after transfecting 0.1-0.6 microM ASODN. 3) To observe cellular and ultra-structural changes under transmission electron microscope and to assay the cellular apoptotic rate by flow cytometry and c-erbB-2 mRNA, and protein expression by RT-PCR and Western blot after transfecting 0.3 microM ASODN.

RESULTS

1) c-erbB-2 protein expression was positive on HEC-1A cell membranes. 2) With the increase of the transfecting ASODN concentration from 0.1-0.6 microM, HEC-1A cellular growth inhibition was also enhanced. The results of MTT showed that when the transfecting concentration of ASODN was 0.3 microM, the HEC-1A cellular growth inhibition rate was 50% while when the transfecting concentration of ASODN was 0.6 microM, the HEC-1A cell growth inhibition rate was 75%. 3) When the concentration of transfecting ASODNs was 0.3 microM, there were obvious vacuolar degenerations in the plasma of HEC-1A cells, disappearance of organelle and nuclear structure and obvious shrinkage of nuclei under transmission electron microscope. The cellular apoptotic rate was 62.80%, while c-erbB-2 mRNA and protein expression were 47.18% and 33.60%, respectively, compared with those of the normal control cells.

CONCLUSION

Transfecting c-erbB-2 ASODNs can obviously suppress the mRNA and protein expression in HEC-1A cells, cause cellular apoptosis and inhibit cell growth. It may be a more useful gene therapy for endometrial cancer.

Association of human leukocyte antigen polymorphism with hepatitis B virus infection and genotypes

Associations were studied between the polymorphism of northern Han Chinese leukocyte antigen (HLA) alleles and the outcomes of hepatitis B virus (HBV) infection and HBV genotypes. HLA-A, B, and DRB1 alleles in peripheral blood mononuclear cells (PBMCs) were detected by polymerase chain reaction (PCR) with sequence-specific primers. The PBMCs were collected from 61 persons who tested positive for hepatitis B surface antigen (HBsAg) for more than 6 months (Persistent group), 32 persons who tested negative for both HBsAg and HBV DNA but positive for both anti-HBc and anti-HBs (Recovered group), and 40 persons who tested negative for all serologic markers of HBV infection (Uninfected group). HBV genotypes in serum specimens from 56 of 61 patients with persistent HBV infection were determined by nested PCR with 6 pairs of HBV genotype-specific primers (A to F). The frequency of HLA-DRB1*12 was significantly higher in the Persistent group than in the Recovered group (P=0.004). HLA-A*02 was significantly higher in the Recovered group than in the Persistent group (P=0.044). HLA-DRB1*15 was significantly higher in the HBV genotype B group than in the C group (P=0.013). These findings suggested that there were associations not only between HLA polymorphisms and outcomes of HBV infection but also between HLA polymorphisms and the infected HBV genotypes.

YMDD mutations and genotypes of hepatitis B virus in northern China

The objective of this research was to determine the relationship between YMDD mutations and the genotypes of hepatitis B virus (HBV) during lamivudine treatment. HBV genotypes were determined by nested PCR with 6 pairs of HBV genotype-specific primers (A to F) in serum specimens from 142 hepatitis B patients receiving lamivudine antiviral therapy. YMDD mutations were detected by fluorescent hybridization bioprobe PCR and melting curve assay (FH-PCR-MC). Among 142 serum specimens, 13 samples were genotype B (9.2%), 125 samples were genotype C (88%), 4 samples were genotype D (2.8%), and 80 YMDD mutations were found. The YMDD mutation rates were 69.2 and 54.4% in genotype B and genotype C, respectively. There was no significant difference in the YMDD mutation rate between genotypes B and C. Nine genotype B sera with YMDD mutations were found, including 2 YIDD mutations and 7 YVDD (M + V) mutations. Sixty-eight genotype C sera with YMDD mutations were found, including 34 mutations I (M + I) and 17 mutations V (M + V). There was a significant difference in the YMDD mutation types between genotypes B and C. Our results suggested that the YMDD mutation rate was 56.3% in patients treated with lamivudine for 2-4 years. YIDD was the main mutation type. The YMDD mutation rate showed no significant difference between HBV types B and C (P > 0.05), while the YMDD mutation types showed a significant difference between HBV types B and C in Northern China (chi2 test = 4.6, P < 0.05).

Epidemiology of HBV genotypes by nested PCR with multi-paired primers

AIM: To investigate the epidemiology of HBV genotypes among HBV-infected persons in northern China.

METHODS: The HBV DNA in 801 sera samples collected from hepatitis patients (594), healthy controls (154), and HCV-infected patients (53) were tested by nested PCR, the positive sera were then genotyped by nested PCR with six pairs of HBV genotype-specific primers (A to F).

RESULTS: 464 samples (57.9%) were HBV DNA positive among the 801 samples. Among 594 cases with various hepatitis B clinical manifestations, 74.4% (442/594) were HBV-DNA positive, while 8.4% (13/154) of healthy controls were HBV-DNA positive. There was significant difference between the hepatitis patients and healthy controls (P < 0.01). 17% (9/53) of HCV-infected patients were HBV-DNA positive, too. Among the 464 HBV-DNA positive samples, the persentage of genotype A was 5.2% (24/464), genotype B 7.1% (33/464), and type C 77.2% (358/464), type D 2.4% (11/464), while none of type E and F had been found in those samples. 14 samples (3%) were both type B and C positive. The 24 samples could not be genotyped in this study.

CONCLUSION: The HBV genotypes prevailed among HBV-infected persons in northern China are types A, B, C, and D, and the major genotype is type C (77.2%). Type C is also the major genotype among the clinical groups. There is no statistical difference between the groups.

High prevalence of hepatitis B virus pre-s mutant in countries where it is endemic and its relationship with genotype and chronicity

It has been reported that hepatitis B virus (HBV) mutants carrying mutations in the pre-S region can be found in infected patients. In this study, we investigated the prevalence of the HBV variant with the pre-S mutant in different geographic regions, including countries with low and high levels of endemic HBV infection, and analyzed the correlation with clinical findings. We examined 387 HBV DNA-positive serum samples from individuals among 12 countries, consisting of Vietnam, Myanmar, Thailand, China, Korea, Nepal, Japan, Russia, Spain, United States, Bolivia, and Ghana. HBV pre-S mutants were detected in 71 (18.3%) of 387 serum samples tested. This mutant was the most prevalent in Vietnam (36%), followed by Nepal (27.3%), Myanmar (23.3%), China (22.4%), Korea (14.3%), Thailand (10.5%), Japan (7.7%), and Ghana (4.3%). In contrast, no case with this mutation was found in Russia, Spain, United States, and Bolivia. Among the HBV deletion mutations, 15.5% (11 of 71) occurred in the pre-S1 and 46.5% (33 of 71) in the pre-S2 regions. Eight (11.3%) cases had a mutation in both the pre-S1 and pre-S2 regions. In addition, a point mutation at the pre-S2 starting codon was observed in 19 (26.7%) cases. The detection rate of the HBV mutant in patients with hepatocellular carcinoma was significantly higher than in other patients (P < 0.05). Furthermore, these mutants were found more frequently in genotype B (25%) and genotype C (24.5%) than in the other genotypes (P < 0.05). Our results indicated that there was a high prevalence of HBV pre-S mutation in regions of endemic HBV infection in Asia. Furthermore, the pre-S mutation appeared to be correlated with hepatocellular carcinoma and HBV genotypes.

[Expressions of TNF-alpha and IL-1beta in human ischemic brain tissues]

AIM

To detect the expression of TNF-alpha and IL-1beta in human cerebral ischemic tissues.

METHODS

13 cerebral specimens from patients died of cerebral infarction were divided into three groups, <2 d, 3-5 d, and >5d, according to the lasting time of infarctions. The expression of TNF-alpha and IL-1beta in the cerebral ischemic tissues were examined by immnohistochemical staining. The contralateral tissues were employed as controls.

RESULTS

The expression of TNF-alpha and IL-1beta in the cerebral ischemic tissues were significant higher than those in the contralateral tissues. The focal distribution of the TNF-alpha(+) and IL-1beta(+) cells was identical with the ischemic area. The expression of IL-1beta and TNF-alpha peaked at the 3rd to 5th and 2nd day after ichemia, respectively. There were no significant difference between the ischemic and contralateral brains at the 5th day after ischemia for the expression of TNF-alpha and IL-1beta.

CONCLUSION

Our results showed the expression of TNF-alpha and IL-1beta in human strok of infarction were similar to those in animal experiments. It is suggested that TNF-alpha and IL-1beta are involved in cerebral ischemic injury, which will be helpful for developing clinically a novel therapy aiming at cerebral ischemic injury.

Molecular epidemiology of hepatitis viruses and genotypic distribution of hepatitis B and C viruses in Harbin, China

We carried out a molecular-based epidemiological survey of hepatitis viruses, including hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis E virus (HEV), in Harbin, China. The study population of 358 subjects consisted of 132 healthy blood donors and 226 liver disease patients residing in Harbin City and surrounding suburbs. The infection rate of each virus among healthy subjects was 14.4% (19/132) for HBV and 2.3% (3/132) for HCV. In contrast, among liver disease patients, the infection rates were 72.6% (164/226) for HBV and 7.5% (17/226) for HCV, respectively (P < 0.01 and P < 0.05, respectively). In particular, nearly 64% of hepatocellular carcinoma patients in Harbin was found to be infected with HBV. The most common viral genotypes were HBV type C (80%) and HCV type 1b (31.3%). Interestingly, a high prevalence of the HBV pre-S1/S2 deletion mutant was found in 13 of 58 (22.4%) subjects. Moreover, testing for HEV among 202 subjects resulted in the detection of anti-HEV IgG in 53 cases (26.2%). The prevalence of anti-HEV IgG has already reached 20% in tested cases aged less than 10 years. These results suggest that HBV infection is widespread in Harbin, China and has led to a high incidence of acute and chronic liver disease in this region.

Insulin binding monitored by fluorescence correlation spectroscopy

AIM/HYPOTHESIS

The characteristics of insulin binding to its receptors have been extensively studied by the radioligand binding assay. We used fluorescence correlation spectroscopy to determine the distribution of diffusion times and further novel data on the kinetics of insulin's binding to its receptor.

METHODS

Cultured human renal tubular cells (HRTC) were incubated with tetramethyl rhodamine labelled insulin (Rh-Ins) for 60 min. Fluorescence intensity fluctuations and autocorrelation functions for Rh-Ins, free in the incubation medium and bound to the cell membrane, were studied at single-molecule detection sensitivity in a 0.2 fL confocal volume.

RESULTS

Measurements at the cell membrane revealed Rh-Ins binding with at least two diffusion components (diffusion times tauD1 = 0.8 ms, tauD2 = 20 ms) and corresponding weight fractions of y1 = 0.43 and y2 = 0.42. Specificity of the binding was shown by the dislocation of bound Rh-Ins when excess unlabelled insulin was added. Scatchard analysis showed a nonlinear plot, revealing two binding processes with different affinities (Kass approximately 2 x 10(10) M(-1) and approximately 1 x 10(9) M(-1), respectively).

CONCLUSION/INTERPRETATION

The fluorescence correlation spectroscopy results show two classes of binding sites with different affinities for insulin, or interactions between receptor sites consistent with negative cooperativity. This conclusion is in agreement with studies of insulin binding using radioligand binding assays. Because of its high sensitivity (single molecule detection), FCS, provides additional data allowing a more precise evaluation of the kinetics of ligand-receptor interactions at low expression levels in living cells.

Detection and differentiation of CAV-1 and CAV-2 by polymerase chain reaction

Canine adenovirus type 1 (CAV-1) and type 2 (CAV-2) can be categorized in the laboratory by haemagglutination and neutralization tests, but they are difficult to differentiate from each other in specimens, especially when infection occurs in the digestive tract. The object of this study was to develop a simple method of detecting and differentiating them. One pair of common primers was designed and synthesized according to the sequences of the E3 and flanking regions and a polymerase chain reaction (PCR) assay was established using these two primers to amplify the virus-specific DNA fragment from clinical specimens as well as from cell cultures. After elecctrophoresis, under the same amplification conditions, 508 bp and 1030 bp PCR products were observed for CAV-1 and CAV-2, respectively. These were further shown to be adenovirus specific by dot hybridization and sequencing. As only one pair of primers was involved in the PCR procedure, it was faster and easier to perform than any of the other assays used for detecting canine adenovirus, making it applicable in the rapid confirmation of diagnosis and differentiation of the two types of canine adenoviruses.

Pharmacokinetics of nortriptyline and its 10-hydroxy metabolite in Chinese subjects of different CYP2D6 genotypes

OBJECTIVES

To study the impact of the CYP2D6*10 allele on the disposition of nortriptyline in Chinese subjects.

METHODS

A single dose of 25 mg nortriptyline was given orally to 15 healthy Chinese volunteers who were classified as extensive metabolizers after phenotyping with debrisoquin (INN, debrisoquine) and who were genotyped by allele-specific polymerase chain reaction. Five subjects were homozygous for CYP2D6*1, 5 subjects were homozygous for CYP2D6*10, and 5 subjects were heterozygous for these 2 alleles. Plasma concentrations of nortriptyline and its main metabolite 10-hydroxynortriptyline were measured by liquid chromatography-mass spectrometry, and the pharmacokinetics were studied during 168 hours after the dose.

RESULTS

Subjects who were homozygous for CYP2D6*10 had significantly higher total areas under the plasma concentration-time curve (AUC), lower apparent oral clearances, and longer mean plasma half-life of nortriptyline than subjects in the CYP2D6*1/*1 and the heterozygous groups. For 10-hydroxynortriptyline, the AUC was lower and the plasma half-life was longer in subjects who were homozygous for CYP2D6*10 than in subjects in the other 2 groups.

CONCLUSION

The CYP2D6*10 allele in Chinese subjects was associated with significantly higher plasma levels of nortriptyline compared with the CYP2D6*1 allele because of an impaired metabolism of nortriptyline to 10-hydroxynortriptyline, particularly in the subjects with the CYP2D6*10/*10 genotype. The results suggest that genotyping of CYP2D6 may be a useful tool in predicting the pharmacokinetics of nortriptyline.

[Effect of liuwei dihuang granules, pills and decoction on contents of cAMP, E2, T, Zn and Cu in plasma of renal yin deficient patients]

Experiments showed that in patients of renal yin deficiency who took orally Liuwei Dihuang granules for 4 weeks, the contents of cAMP, E2, Zn and Cu were found mankedly lower, but the contents of T mankedly higher than before using the drugs. This indicates that the granules are equally effective as pills and decoction.