Periostin, the distribution and expression of which were consistent with the extent of myocardial fibrosis, might be a potential biomarker of cardiac remodeling in heart failure patients.
Obstructive sleep apnea syndrome (OSAS) is associated with many cardiovascular disorders such as heart failure, hypertension, atherosclerosis, and arrhythmia and so on. Of the many associated factors, chronic intermittent hypoxia (CIH) in particular is the primary player in OSAS. To assess the effects of CIH on cardiac function secondary to OSAS, we established a model to study the effects of CIH on Wistar rats. Specifically, we examined the possible underlying cellular mechanisms of hypoxic tissue damage and the possible protective role of adiponectin against hypoxic insults. In the first treatment group, rats were exposed to CIH conditions (nadir O2, 5–6%) for 8 hours/day, for 5 weeks. Subsequent CIH-induced cardiac dysfunction was measured by echocardiograph. Compared with the normal control (NC) group, rats in the CIH-exposed group experienced elevated levels of left ventricular end-systolic dimension and left ventricular end-systolic volume and depressed levels of left ventricular ejection fraction and left ventricular fractional shortening (p<0.05). However, when adiponectin (Ad) was added in CIH + Ad group, we saw a rescue in the elevations of the aforementioned left ventricular function (p<0.05). To assess critical cardiac injury, we detected myocardial apoptosis by Terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling (TUNEL) analysis. It was showed that the apoptosis percentage in CIH group (2.948%) was significantly higher than that in NC group (0.4167%) and CIH + Ad group (1.219%) (p<0.05). Protein expressions of cleaved caspase-3, cleaved caspase-9, and cleaved-caspase-12 validated our TUNEL results (p<0.05). Mechanistically, our results demonstrated that the proteins expressed with endoplasmic reticulum stress and the expression of reactive oxygen species (ROS) were significantly elevated under CIH conditions, whereas Ad supplementation partially decreased them. Overall, our results suggested that Ad augmentation could improve CIH-induced left ventricular dysfunction and associated myocardial apoptosis by inhibition of ROS-dependent ER stress.
Chronic heart failure (CHF) is responsible for significant morbidity and mortality worldwide, mainly as a result of neurohumoral activation. Acupuncture has been used to treat a wide range of diseases and conditions. In this study, we investigated the effects of electroacupuncture (EA) on the sympathetic nerve activity, heart function, and remodeling in CHF rats after ligation of the left anterior descending coronary artery. CHF rats were randomly selected to EA and control groups for acute and chronic experiments. In the acute experiment, both the renal sympathetic nerve activity and cardiac sympathetic afferent reflex elicited by epicardial application of capsaicin were recorded. In the chronic experiment, we performed EA for 30 min once a day for 1 wk to test the long-term EA effects on heart function, remodeling, as well as infarct size in CHF rats. The results show EA significantly decreased the renal sympathetic nerve activity effectively, inhibited cardiac sympathetic afferent reflex, and lowered the blood pressure of CHF rats. Treating CHF rats with EA for 1 wk dramatically increased left ventricular ejection fraction and left ventricular fraction shortening, reversed the enlargement of left ventricular end-systolic dimension and left ventricular end-diastolic dimension, and shrunk the infarct size. In this experiment, we demonstrated EA attenuates sympathetic overactivity. Additionally, long-term EA improves cardiac function and remodeling and reduces infarct size in CHF rats. EA is a novel and potentially useful therapy for treating CHF.
Background
Chronic intermittent hypoxia (
CIH
) is a distinct pathological mechanism of obstructive sleep apnea (
OSA
), which is recognized as an independent risk factor for cardiovascular diseases. The aims of this study were to ascertain whether
CIH
induces atrial fibrillation (
AF
), to determine whether cardiac sympathetic denervation (
CSD
) can prevent it and suppress blood pressure, and to explore the potential molecular mechanisms involved.
Methods and Results
Sixty Sprague‐Dawley male rats were randomly divided into 4 groups: sham,
CSD
,
CIH
,
CIH
+
CSD
. The rats were exposed either to
CIH
8 hours daily or normoxia for 6 weeks. Cardiac pathology and structure were analyzed by hematoxylin and eosin staining and echocardiogram. ECG, blood pressure, body weight, and blood gas were recorded. Connexin 43 and tyrosine hydroxylase were detected by western blot, immunohistochemistry, and immunofluorescence.
CIH
induced atrial remodeling, and increased
AF
inducibility.
CSD
treatment reduced postapneic blood pressure rises and
AF
susceptibility, which could attenuate
CIH
‐associated structural atrial arrhythmogenic remodeling. In addition,
CIH
‐induced sympathetic nerve hyperinnervation and
CSD
treatment reduced sympathetic innervation, which may affect
CIH
‐induced
AF
‐associated sympathovagal imbalance. Connexin 43 was specifically downregulated in
CIH
, whereas
CSD
treatment increased its expression.
Conclusions
These results suggested
CIH
induces atrial remodeling, increases
AF
inducibility, results in sympathetic nerve hyperinnervation, and decreases connexin 43 expression, but
CSD
treatment reduces
AF
susceptibility, postapneic blood pressure increase, sympathetic innervation, and the alteration of Cx43, which may be a key point in the genesis of
CIH
‐induced
AF
.
Ribosomal protein L22 (RPL22), an RNA-binding protein, is a constituent of the 60S large ribosomal subunit. As reported, RPL22 is not required in protein synthesis, and mutations of RPL22 were the main cause of macrolide resistance in bacteria. In vertebrates, RPL22 mutation might increase the proliferation of cells and then increase cancer risk. However, to our knowledge, RPL22 has not been implicated in any lung diseases, especially in lung cancer. In this study, we compared the expression of RPL22 gene in non-small cell lung cancer (NSCLC) tissues, plasma as well as human lung cancer cell line LTEP-a-2 with that in normal lung tissues and cells, using real-time RT-qPCR, Western blot, quantitative immunohistochemistry analysis, and ELISA. Our studies showed that the expression of RPL22 was significantly down-regulated in mRNA and protein expression level in NSCLC; however, there was no significant difference of RPL22 levels in plasma between normal and NSCLC patients. Further analysis indicated that down-regulation of RPL22 might be involved in the carcinogenesis of NSCLC, yet not an effective biomarker in plasma for early diagnosis.
RVHD patients with OSA have an increased incidence of perioperative adverse events. OSA was independently associated with overall postoperative recovery, respiratory insufficiency, and higher rate of postoperative pacemaker use, while CSA was not associated with postoperative events.
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