Israel Medical Association Journal

Twenty years after being closed due to unfavorable results, a new lung transplant program was started at the Sheba Medical Center. The new team included an experienced lung transplant surgeon, an anesthesiologist, an intensive care specialist, and a pulmonologist with extensive experience in the field.

Background: Systemic CD11b+ cells have been associated with several cardiac diseases, such as chronic heart failure.

Objectives: To assess the levels of circulating CD11b+ cells and pro-inflammatory cytokines in cardiomyopathy induced by chronic adrenergic stimulation.

Methods: Male Lewis rats were injected with low doses of isoproterenol (isoprel) for 3 months. Cardiac parameters were tested by echocardiography. The percentage of CD11b+ cells was tested by flow cytometry. The levels of inflammatory cytokines in the sera were determined by an inflammation array, and the expression levels of cardiac interleukin-1 (IL-1) receptors were analyzed by real-time polymerase chain reactions. Cardiac fibrosis and inflammation were determined by histological analysis.

Results: Chronic isoprel administration resulted in increased heart rate, cardiac hypertrophy, elevated cardiac peri-vascular fibrosis, reduced fractional shortening, and increased heart weight per body weight ratio compared to control animals. This clinical presentation was associated with accumulation of CD11b+ cells in the spleen with no concomitant cardiac inflammation. Cardiac dysfunction was also associated with elevated sera levels of IL-1 alpha and over expression of cardiac IL-1 receptor type 2.

Conclusions: CD11b+ systemic levels and IL-1 signaling are associated with cardiomyopathy induced by chronic adrenergic stimulation. Further studies are needed to define the role of systemic immunomodulation in this cardiomyopathy.

 

Background: Chronic kidney disease (CKD) is often accompanied by impairment of cardiac function that may lead to major cardiac events. Erythropoietin (EPO), a kidney-produced protein, was shown to be beneficial to heart function. It was suggested that reduced EPO secretion in CKD may play a role in the initiation of heart damage. 

Objectives: To investigate molecular changes in the EPO/erythropoietin receptor (EPO-R) axis in rat cardiomyocytes using a rat model for CKD.

Methods: We established a rat model for CKD by kidney resection. Cardiac tissue sections were stained with Masson’s trichrome to assess interstitial fibrosis indicating cardiac damage. To evaluate changes in the EPO/EPO-R signaling cascade in the myocardium we measured cardiac EPO and EPO-R as well as the phosphorylation levels of STAT-5, a downstream element in this cascade.

Results: At 11 weeks after resection, animals presented severe renal failure reflected by reduced creatinine clearance, elevated blood urea nitrogen and presence of anemia. Histological analysis revealed enhanced fibrosis in cardiac sections of CKD animals compared to the sham controls. Parallel to these changes, we found that although cardiac EPO levels were similar in both groups, the expression of EPO-R and the activated form of its downstream protein STAT-5 were significantly lower in CKD animals.

Conclusions: CKD results in molecular changes in the EPO/EPO-R axis. These changes may play a role in early cardiac damage observed in the cardiorenal syndrome.