Increased leukocyte Rho-kinase activity in a population with acute coronary syndrome

Interventional Transcatheter Closure Ameliorates the Leukocyte Rho Kinase Activities among Patients with Patent Ductus Arteriosus

BACKGROUND

Patent ductus arteriosus (PDA) causes increased pulmonary blood flow, which can lead to pulmonary arterial hypertension (PAH). Rho-associated coiled-coil containing protein kinase (ROCK) may play an important pathophysiological role in PAH. We hypothesized that the increased pulmonary artery (PA) flow from PDA could activate ROCK.

METHODS

Patients who received a PDA transcatheter closure in our hospital were consecutively enrolled in this study. Basic demographics and clinical hemodynamic data of the study participants were recorded. Then, ROCK activity was measured before and after the PDA occlusion procedure. ROCK activity was defined as the phosphorylation ratio of myosin-binding subunit by Western blot measurement. We also sub-divided patients into the coil group and occluder group based on the occlusion device used in each patient's procedure.

RESULTS

From January 2009 to December 2011, 25 patients with a median age of 2.3 years, ranging from 10 months to 72 years were enrolled. The mean PDA size was 0.31 ± 0.14 cm, the mean Qp/Qs shunt was 1.54 ± 0.41, and the mean systolic pulmonary artery pressure was 26.9 ± 10.3 mmHg. There were 10 patients (one boy and nine girls) in the coil group and 15 patients (four boys and eleven girls) in the occluder group. Following the closure of the PDA, ROCK activity significantly decreased (1.78 ± 2.25 vs. 0.77 ± 0.69, p < 0.01). There was a strong correlation between the leukocyte ROCK activity with the systolic PA pressure (y = 5.4608x + 22.54, R2 = 0.5539, p < 0.05), but not the Qp/Qs value. Both subgroups showed significant changes of ROCK activity after the procedure. Interestingly, when comparing the coil group with the occluder group, the decrease in ROCK activity was more apparent in the occluder group.

CONCLUSIONS

The findings of this study indicated that ROCK activity is higher in patients with PDA and correlates with PA pressure. The decrease in ROCK activity following the device closure suggests that ROCK may be an important biomarker for PDA patency.

KEY WORDS

Patent ductus arteriosus (PDA); Pulmonary arterial pressure; Rho kinase; Transcatheter closure.

Clinical implications of tenascin-C and OX40 ligand in patients with acute coronary syndrome

Acute coronary syndrome (ACS) typically occurs when coronary artery disease results in the obstruction of the coronary arteries. Tenascin-C (TNC) and OX40 ligand (OX40L) were shown to be involved in the pathogenesis of atherosclerosis. In this study, 50 healthy controls and 170 patients, including 50 patients with stable angina (SA), 70 with unstable angina and 50 with acute myocardial infarction, were evaluated to assess serum TNC and plasma OX40L levels. The serum TNC levels were measured by a quantitative automated particle-enhanced immunonephelometric assay. ELISA was used to determine the expression levels of OX40L. All the coronary stenoses with a ≥30% diameter reduction were assessed by angiographic coronary stenosis morphology. The patients with ACS exhibited a significant increase in TNC expression levels (39.39±19.80 ng/ml) compared to the levels in the control and SA groups (28.65±12.32 ng/ml, P<0.01 and 31.22±18.92 ng/ml, P<0.05, respectively). The levels of OX40L were also found to be higher in patients with ACS (38.59±15.76 ng/ml) compared to those in the control and SA groups (19.42±11.19 ng/ml, P<0.001 and 21.52±10.30 ng/ml, P<0.001, respectively). The TNC and OX40L levels were positively correlated with each other (r₁=0.68; P<0.001) and with fibrinogen levels (r₃=0.76 and r₄=0.45, respectively; P<0.001). A positive correlation was also observed between the expression of TNC and OX40L and complex coronary stenosis (r₅=0.69 and r₆=0.55, respectively; P<0.001). We concluded that TNC and OX40L may act synergistically in coronary plaque formation and may be also be involved in the pathogenesis of coronary lesions. Patients with ACS exhibited increased TNC and OX40L expression levels, which may have created a prothrombotic milieu, aggravating the development of atherosclerosis and the instability of atherosclerotic plaques. Therefore, the expression of TNC and OX40L may be a valuable marker for predicting the severity of ACS.