The roles of p62/SQSTM1 on regulation of matrix metalloproteinase-9 gene expression in response to oxLDL in atherosclerosis.

OBJECTIVE: Matrix metalloproteinase-9 (MMP-9) plays an important role in the remodeling of the extracellular matrix in atherosclerosis plaques. Autophagy protects macrophages against the processes of vascular disease. Our research explores how autophagy plays roles in macrophages to secret MMP-9. METHODS AND RESULTS: In response to increased doses of oxLDL or CQ we monitored the autophagic flux. Our results revealed that oxLDL was dynamically associated with autophagy and 100 µg/ml oxLDL blocked autophagic flux in THP-1 cells. Moreover p62/SQSTM1 knocking down and CQ respectively inhibited and increased MMP-9 transcriptional expression. These effects were mediated by inhibition of NF-κB. CONCLUSION: Abundant oxLDL blocked autophagic flux resulting in the aggregation of p62/SQSTM1. Then p62/SQSTM1 was involved in gene expression of MMP-9 via NF-κB-dependent signaling, and thus featuring novel plaque vulnerability properties of the atherosclerotic plaque. Understanding the mechanism that selectively modulates p62/SQSTM1 will provide a novel strategy for anti-atherogenesis.

Trends in HIV infection in the First Affiliated Hospital of Harbin, China.

BACKGROUND: Major hospitals in most Chinese cities have the capability to perform HIV testing. However, it is not a routine test for all patients and, as a result, many patients are not aware of their HIV status. To understand the rate of HIV infection and the factors associated with infection, we tested serum to determine HIV status and analyzed factors associated with HIV infection. METHODS: We collected blood samples from 348,151 patients who visited the First Affiliated Hospital of Harbin Medical University from 1 January 2007 to 31 December 2012. Serum was screened with an ELISA. If the test was positive, we conducted two additional ELISAs: a repeat with the initial kit and one with another kit. If there was a positive result with either of these two ELISA kits, western blotting was performed at Harbin Centers for Disease Control and Prevention. RESULTS: The HIV positivity rate of inpatients significantly increased during the course of this study. HIV infection in patients appeared to differ by sex, age, occupation, marital status, educational level, and route of infection. HIV was more prevalent in men than in women. More than 80% of HIV-positive patients had not received higher (>12 years) education. From 2007 to 2012, HIV-positive patients were mainly infected through sexual transmission. For sexually acquired infections, the rate of HIV infections through homosexual contact has increased rapidly in recent years, and ranged from 36.4% to 65.1%. CONCLUSIONS: The number of patients diagnosed as HIV positive has increased in recent years. Offering routine HIV testing in hospitals is feasible and can increase linkage to HIV care and treatment for many individuals.

Influenza virus infection and risk of acute myocardial infarction.

Increasing evidences have shown that pathogens might promote atherosclerosis and trigger acute myocardial infarction (AMI). But the conclusions from various studies on the correlation between previous influenza virus (IV) infection and AMI were inconsistent. We conducted a case-control study to assess the association of previous IV infection and AMI. Questionnaire survey was conducted to collect information about demographic characteristics and heart disease risk factors. Fasting blood sample was obtained to measure IgG antibodies to influenza virus A(IV-A), influenza virus B(IV-B), cytomegalovirus (CMV), herpes simplex virus type-1 (HSV-1) and type-2 (HSV-2), adenovirus (ADV), rubella virus (RV) and Chlamydia pneumoniae (CP) and measure the level of some biochemistry markers. Compared to controls, cases were more likely to have positive IgG antibodies to IV-A and IV-B (IV-A: OR, 3.3; 95%CI, 1.5 to 7.4; IV-B: OR, 17.2; 95%CI, 7.7 to 38.0). After adjustment for potential confounding variables, the risk of AMI was still associated with the presence of IgG antibodies to IV-A (adjusted OR, 7.5; 95%CI, 1.3 to 43.0) and IV-B (adjusted OR, 27.3; 95%CI, 6.6 to 113.8). The study supported the hypothesis that previous IV infection took part in the development of atherosclerosis and trigger the occurrence of AMI.

Combination therapy of siRNAs mediates greater suppression on hepatitis B virus cccDNA in HepG2.2.15 cell.

BACKGROUND/AIMS: Hepatitis B virus (HBV) infection is a world-wide health problem. The major obstacles for current anti-HBV therapy are the low efficacy and the occurrence of drug resistant HBV mutations. Recent studies have demonstrated that combination therapy can enhance antiviral efficacy and overcome the shortcomings. Here, the inhibitory effect mediated by combination of small interfering RNAs (siRNAs) targeting different sites of HBV nuclear localization signal (NLS) was monitored in HepG2.2.15 cells. METHODOLOGY: Recombinant plasmid psil-HBV was constructed and transfected into HepG2.2.15 cells. At 48, 72 and 96 h after transfection, culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay. Intracellular viral DNA and covalently closed circular DNA (cccDNA) was quantified by real-time PCR. HBV viral mRNA was reverse transcribed and quantified by reverse-transcript PCR. RESULTS: Our data demonstrated that three used siRNAs showed marked anti-HBV effects. The expression of HBsAg and the replication of HBV DNA could be specifically inhibited in a dose-dependent manner by siRNAs. Furthermore, combination of siRNAs, compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication, even though the final concentration of siRNA in the therapy was the same. More importantly, we showed that combination therapy significantly suppressed HBV cccDNA amplification. CONCLUSION: Our results revealed that combination of siRNAs mediated a stronger inhibition on viral replication and antigen expression in HepG2.2.15 cells, especially, the amplification of cccDNA.

[Relationship between plasma brain natriuretic peptide concentration and clinical prognosis in patients of acute myocardial infarction].

OBJECTIVE: To evaluate the value of brain natriuretic peptide (BNP) in estimating risk stratification in patients with acute myocardial infarction (AMI) and to determine the relationship between BNP and adverse cardiac events after AMI. METHODS: The 135 subjects were selected into the study, including 25 healthy subjects and 110 patients with a first AMI. The plasma concentrations of BNP were measured at two to four days after infarction in patients and healthy controls. Left ventricular function was evaluated by echocardiography with the parameters of left ventricular ejection function (LVEF) after 3 months. Patients were followed up at 12 months. The main outcome measures were heart failure, left remodeling, mortality and other adverse cardiac events at one year. RESULTS: Plasma BNP concentrations in patients with AMI were much higher than those in the health control people (416.7 +/- 208.0 ng/L versus 61.8 +/- 34.1 ng/L, P < 0.01). The BNP count ranged from 5 to 2500 ng/L in AMI patients. There was no association between the BNP count and mortality rate. The development of new congestive heart failure (CHF) was associated with a higher BNP count (P = 0.02). The development of any of the clinical end points (death/CHF/shock) occurred more frequently in patients with a higher BNP count (13.8% for BNP count of < 100 ng/L, 39.1% for BNP count of 100 - 200 ng/L, 43.3% for BNP count of 200 - 400 ng/L, 46.4% for BNP count of > 400 ng/L; P = 0.019). Plasma BNP concentrations remained independently associated with the development of clinical end points in multivariable model that adjusted for potential confounding variables. CONCLUSION: The results of the present study confirm that the elevated BNP count related to the risk stratification and prognosis in patients with AMI. Elevations in BNP count are associated with a higher incidence of new CHF and adverse clinical outcomes after AMI. It could serve as a strong predictor for the subsequent development of poor outcomes in AMI patients.

Position 22 of the V3 loop is associated with co-receptor usage and disease progression in HIV-1 subtype B isolates.

Our goal in this study was to analyze position 22 of the V3 loop associated with co-receptor usage and disease progression in human immunodeficiency virus type 1 (HIV-1) subtype B infection. Bioinformatics approaches were used to compare the amino acid sequence and secondary structure of the V3 loop of the CCR5-tropic virus and CXCR4-tropic virus in HIV-1 subtype B. HIV-1 subtype B V3 amino acid sequence files in the FASTA format were collected from the HIV Sequence Database. The amino acid sequences of different tropism were multiple-aligned with CLUSTAL W program, and the frequencies of the amino acids at each position of the V3 loop sequences of two groups were calculated and sorted in descending order. The secondary structure of the consensus V3 amino acid sequences from CCR5-tropic and CXCR4-tropic viruses were predicted with the APSSP2 method. The amino acids at positions 11, 22, and 25 of V3 were different between the CCR5-tropic virus and CXCR4-tropic virus. The consensus amino acid frequencies were found to be 71.9% S, 66.7% A, and 56.0% D for the CCR5-tropic virus and 50.0% R, 57.1% T, and 26.2% Q for the CXCR4- tropic virus at positions 11, 22, and 25, respectively. There was a strong association between the identity of the residues at position 11, 22, and 25 of the V3 loop amino acid sequence and CD4+ T cell counts of different patients. The change of the residue at position 22 in the R5-tropic or X4-tropic viruses is expected to likely change the secondary structure to be similar to the X4-tropic or R5-tropic viruses. Our study indicates that position 22 of the V3 loop amino acid sequence is significantly associated with viral tropism and disease progression in HIV-1 subtype B.

Respiratory syncytial virus infection and risk of acute myocardial infarction.

INTRODUCTION: Increasing evidences have shown that pathogens may promote atherosclerosis and trigger acute myocardial infarction (AMI). There is no report on the association between respiratory syncytial virus (RSV) infection and AMI. The case-control study was used to assess the association of previous RSV infection and acute myocardial infarction. METHODS: AMI cases and non-AMI controls were recruited from patients at a large teaching hospital in Harbin, China, during October 1, 2005, to March 31, 2006, and October 1, 2006, to March 31, 2007. Questionnaire survey was conducted to collect information on demographic characteristics and heart disease risk factors. Fasting blood sample was obtained to measure immunoglobulin G antibodies to RSV, Cytomegalovirus, herpes simplex virus type-1 and type-2, adenovirus, Rubella virus, Chlamydia pneumoniae and Helicobacter pylori and to measure the level of cholesterol, fasting serum glucose, triglycerides and high-sensitivity C-reactive protein. RESULTS: AMI group had more smokers than controls (56.9% versus 18.0%) and were more likely to have positive immunoglobulin G antibodies to RSV (OR, 6.2; 95% CI, 3.5-10.7; P < 0.001). After adjustment for potential confounding variables, the association between RSV and AMI remained (adjusted odds ratio, 11.1; 95% confidence interval, 3.3-29.5). CONCLUSIONS: Our study supported the hypothesis that the previous RSV infection was associated with AMI. This indicates that prevention and proper treatment of RSV infection are of great clinical importance for the reduction of AMI risk.

[Expression of co-stimulatory molecules and role of interleukin 18 in peripheral lymphocytes of patients with idiopathic thrombocytopenic purpura].

The objective of study was to investigate the expressions of CD80, CD86 and its ligand CD28 on peripheral lymphocytes in patients with idiopathic thrombocytopenic purpura (ITP), to explore the effect of interleukin 18 (IL-18) and its clinical significance in ITP. The expressions of co-stimulatory molecules (CD80, CD86 and its ligand CD28) on peripheral lymphocytes from 34 ITP patients and 34 normal humans were detected by immunofluorescence and flow cytometry. The IL-18 in the plasma was detected by using enzyme linked immunosorbent assay (ELISA). The results showed that the expressions of CD80 and CD86 on peripheral lymphocytes from ITP patients were higher than that of the normal control (4.21 +/- 2.27%, 7.19 +/- 5.16% vs 2.34 +/- 0.87%, 4.08 +/- 1.96%) (P < 0.01); the concentration of IL-18 in plasma of ITP patients was (538.31 +/- 111.33) pg/ml, but the concentration of IL-18 in plasma of controls was (489.44 +/- 49.07) pg/ml. The level of IL-18 negatively correlated with the platelet counts in peripheral blood (r = -0.395, P < 0.05). It is concluded that the CD28/CD80 and CD28/CD86 costimulatory molecules are overexpressed, when the IL-18 level in ITP patients is obviously higher than that in normal controls. When ITP occurred, and the co-stimulatory molecules CD80 and CD86 are closely associated with ITP, it seems that IL-18 may play an important role in ITP pathogenesis.