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Gap junctions are the main form of interaction between cardiomyocytes, through which the electrochemical activities between cardiomyocytes can be synchronized to maintain the normal function of the heart. Connexins are the basis of gap junctions. Changes in the expression, structural changes (e.g., phosphorylation and dephosphorylation), and distribution of connexins can affect the normal electrophysiological activities of the heart. Myocardial infarction (MI) and concurrent arrhythmia, shock, or heart failure can endanger life. The structural and functional damage of connexin (Cx) 43 in cardiomyocytes is a central part of the pathological progression of MI and is one of the main pathological mechanisms of arrhythmia after MI. Therefore, increasing Cx43 expression has become one of the main measures to prevent MI. Also, intervention in Cx43 expression can improve the structural and electrical remodeling of the myocardium to improve MI prognosis. Here, research progress of Cx43 in MI and its prevention and treatment using Traditional Chinese Medicine formulations is reviewed.

Aims This systematic review aimed to study the hippocampal and frontal changes of heart failure (HF) patients and HF animal models with cognitive impairment or depression. Methods A systematic review of the literature was conducted independently by reviewers using PubMed, Web of Science, Embase, and the Cochrane Library databases. Results and conclusions 30 studies were included, involving 17 pieces of clinical research on HF patients and 13 studies of HF animal models. In HF patients, the hippocampal injuries were shown in the reduction of volume, CBF, glucose metabolism, and gray matter, which were mainly observed in the right hippocampus. The frontal damages were only in reduced gray matter and have no difference between the right and left sides. The included HF animal model studies were generalized and demonstrated the changes in inflammation and apoptosis, synaptic reduction, and neurotransmitter disorders in the hippocampus and frontal lobes. The results of HF animal model studies complemented the clinical observations by providing potential mechanistic explanations of the changes in the hippocampus and frontal lobes.

Patients with heart failure (HF) are more susceptible to cognitive impairment, but the mechanism is still unclear. This study aimed to observe the dynamic changes in brain glucose metabolism and neuronal structure in different stages of HF. An HF rat model was established by ligating the anterior descending branch of the left coronary artery. To simulate acute heart failure (AHF) and chronic heart failure (CHF) in the clinic, relevant laboratory indexes were detected 10 and 60 days after ligation. The results showed that the model rats had systolic HF. Cognitive function was not obviously impaired in 10-day rats with HF, while the memory and learning functions were significantly impaired in 60-day rats with HF. The brain glucose metabolism in 10-day rats compensatorily increased in the prefrontal cortex (PFC), medial PFC (mPFC), cingulate gyrus, and basal ganglia (BG). In contrast, the metabolism of 60-day rats reduced in the PFC and BG. Meanwhile, the neuronal structure slightly changed in 10-day rats with HF, but neuronal karyopyknosis, reduced Nissl bodies, and swollen organelles were found in 60-day rats with HF. In conclusion, brain glucose metabolism and neuronal structure showed a dynamic evolution. Rats with AHF were in a compensatory state for increased glucose metabolism and slight neuronal damage. As a result, no significant cognitive impairment was observed. However, rats with CHF had significantly decreased cerebral glucose metabolism and neuronal degeneration, contributing to the cognitive function after HF.

Metabolic modulation is a promising therapy for ischemic heart disease and heart failure. This study aimed to clarify the regional modulatory effect of Qiliqiangxin capsules (QLQX), a traditional Chinese medicine, on cardiac metabolic phenotypes. Sprague–Dawley rats underwent left anterior descending coronary artery ligation and were treated with QLQX and enalapril. Striking global left ventricular dysfunction and left ventricular remodeling were significantly improved by QLQX. In addition to the posterior wall, QLQX also had a unique beneficial effect on the anterior wall subject to a severe oxygen deficit. Cardiac tissues in the border and remote areas were separated for detection. QLQX enhanced the cardiac 18F-fluorodeoxyglucose uptake and the levels and translocation of glucose transport 4 (GLUT4) in the border area. Meanwhile, it also suppressed glucose transport 1 (GLUT1) in both areas, indicating that QLQX encouraged border myocytes to use more glucose in a GLUT4-dependent manner. It was inferred that QLQX promoted a shift from glucose oxidation to anaerobic glycolysis in the border area by the augmentation of phosphorylated pyruvate dehydrogenase, pyruvate dehydrogenase kinases 4, and lactic dehydrogenase A. QLQX also upregulated the protein expression of fatty acid translocase and carnitine palmitoyl transferase-1 in the remote area to possibly normalize fatty acid (FA) uptake and oxidation similar to that in healthy hearts. QLQX protected global viable cardiomyocytes and promoted metabolic flexibility by modulating metabolic proteins regionally, indicating its potential for driving the border myocardium into an anaerobic glycolytic pathway against hypoxia injuries and urging the remote myocardium to oxidize FA to maximize energy production.

Background/Aims: Qiliqiangxin (QL), a traditional Chinese medicine, has been demonstrated to be effective and safe for the treatment of chronic heart failure. Left ventricular (LV) remodeling causes depressed cardiac performance and is an independent determinant of morbidity and mortality after myocardial infarction (MI). Our previous studies have shown that QL exhibits cardiac protective effects against heart failure after MI. The objective of this study was to explore the effects of QL on myocardial fibrosis in rats with MI and to investigate the underlying mechanism of these effects. Methods: A rat model of acute myocardial infarction was induced by ligating the left anterior descending coronary artery. The rats were treated with QL (1.0 g/kg/day) for 4 weeks after surgery. Echocardiography and histology examination were performed to evaluate heart function and fibrosis, respectively. Protein levels of transforming growth factor-β1 (TGF-β1), phosphorylated Smad3 (p-Smad3), phosphorylated Smad7 (p-Smad7), collagen I (Col- I), alpha smooth muscle actin (a-SMA), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), nuclear factor κB (NF-κB), and phosphorylated inhibitor of kappa B alpha (p-IκBα) were measured by western blot analysis. Results: QL treatment ameliorated adverse cardiac remodeling 8 weeks after AMI, including better preservation of cardiac function, decreased inflammation, and reduced fibrosis. In addition, QL treatment reduced Col-I, a-SMA, TGF-β1, and p-Smad3 expression levels but increased p-Smad7 levels in postmyocardial infarct rat hearts. QL administration also reduced the elevated levels of cardiac inflammation mediators, such as TNF-α and IL-6, as well as NF-κB and p-IκBα expression. Conclusions: QL therapy exerted protective effects against cardiac remodeling potentially by inhibiting TGF-β1/Smad3 and NF-κB signaling pathways, thereby preserving cardiac function, as well as reducing myocardial inflammation and fibrosis.

Aim This study aimed to find a more sensitive and systematic behavioral evaluation protocol to evaluate the cognitive impairment in rats with heart failure (HF). Methods and results An HF rat model was built by ligating the left anterior descending coronary artery. The cardiac function and structure were detected using echocardiography. Myocardial histopathological changes were observed by nitro blue tetrazolium and hematoxylin–eosin staining. The cognitive functions were evaluated using the acquisition task, probe trial, reversal test, and matching‐to‐sample test of the Morris water maze. In the probe trial, the number of times the rats in the model group crossed the platform site significantly decreased compared with that in the sham group. In the reversal test, the average latency was significantly longer in the sham group compared with the model group in the first trial but was shorter in the second and third trials. In the matching‐to‐sample test, the average latency of Trial1 increased significantly in the model group compared with the sham group, while no obvious difference was observed in Trial2. Therefore, the difference in the average latency between Trial1 and Trial2 of the model group was significantly larger. Conclusions The cognitive impairment in rats with HF mainly reflected in the long‐term and working memory, spatial learning, and reversal learning ability. The probe trial and reversal test in the water maze may be more sensitive and preferred to evaluate cognitive function after HF. These findings would provide a brief evaluation protocol for further studies on the relationship between cognitive function and HF., This study aimed to find a more sensitive and systematic behavioral evaluation protocol to evaluate the cognitive impairment in rats with heart failure (HF).The cognitive impairment in rats with HF mainly reflected in the long‐term and working memory, spatial learning and reversal learning ability.

Qili qiangxin (QL) capsule is a traditional Chinese medicine that is widely used for the treatment of patients with chronic heart failure (CHF) of all etiologies, although the exact mechanisms of action remain unclear. CHF leads to pulmonary vascular remodelling and thickening of the alveolar-capillary barrier that may be important mechanisms in the poor clinical outcome in patients with end-stage heart failure. We examined whether QL could improve lung injury in ischemic CHF by reducing lung remodeling. Rats with myocardial infarct received QL (1.0 g/kg/day) for 4 weeks. Echocardiographic and morphometric measurements were obtained followed by echocardiography, histological staining, and immunohistochemical analysis of lung sections. CHF caused significant lung structural remodeling evidenced by collagen deposition and thickening of the alveolar septa after myocardial infarct that were greatly improved by QL. Lung weight increased after infarct with no evidence of pulmonary edema and was normalized by QL. QL also reduced lung transforming growth factor-β1 (TGF-β1), p-Smad3, tumor necrosis factor-α(TNF-α), and Toll-like receptor-4 (TLR4) expression. Thus, QL reduces lung remodeling associated with CHF, mainly by suppressing the TGF-β1/Smad3 signaling pathway. The mechanism may also involve inhibition of TLR4 intracellular signaling.

To establish a new method for early evaluation and screening of heart failure model after myocardial infarction and provide basis for early random grouping on drug intervention study. SD Rats were randomly divided into model and sham group. The MI models were established by ligating left anterior

Qili qiangxin capsule (QL), a traditional Chinese herbal compound, has been proved to be effective and safe for the treatment of chronic heart failure (CHF). Upregulation of aquaporin-2 (AQP2) accounts for the water retention in CHF. The aim of the present study was to evaluate the effects of QL on the expression of AQP2 in rats with CHF induced by acute myocardial infarction and to investigate the underlying mechanisms. The urine output of all rats was quantified and collected every day at the first week and the 4th week after administration of QL or Valsartan. The expression of AQP2, vasopressin type 2 receptor (V2R), and angiotensin II type 1 receptor (AT1R) were examined after treatment for 4 weeks. Urinary output increased significantly after administration of QL. Importantly, the protein expression of AQP2 and AQP2 phosphorylated at serine 256 (pS256-AQP2) was downregulated after administration of QL and Valsartan to CHF rats. Furthermore, QL reduced plasma arginine vasopressin (AVP) and angiotensin II (AngII) level and downregulated V2R and AT1R protein expression. Thus, QL exerts its diuretic effect and improves cardiac function in CHF rats by reversing the increases in both AQP2 and pS256-AQP2 expression. The possible mechanisms may involve inhibition of V2R and AT1R.

Objective. To explore the mechanism of cardioprotective effects of Chinese medicine, Yiqi Huoxue recipe, in rats with myocardial infarction- (MI-) induced heart failure.Methods. Male Sprague-Dawley rats underwent left anterior descending artery (LAD) ligation or sham operation. The surviving MI rats were divided randomly into three groups: MI (5 mL/kg/d NS by gavage), MI + Metoprolol Tartrate (MT) (12 mg/kg/d MT by gavage), and MI + Yiqi Huoxue (5 mL/kg recipe by gavage). And the sham operation rats were given 5 mL/kg/d normal saline. Treatments were given on the day following surgery for 4 weeks. Then rats were detected for heart structure and function by transthoracic echocardiography. Apoptosis in heart tissues was detected by TUNEL staining. To determine whether the endoplasmic reticulum (ER) stress response pathway is included in the cardioprotective function of the recipe, ER stress related proteins such as GRP78 and caspase-12 were examined.Results. Yiqi Huoxue recipe attenuated heart function injury, reversed histopathological damage, alleviated myocardial apoptosis and inhibited ER stress in MI rats.Conclusion. All the results suggest that Yiqi Huoxue recipe improves the injured heart function maybe through inhibition of ER stress response pathway, which is a promising target in therapy for heart failure.

Objective. We investigated the effects of WXKL on the action potential (AP) and the L-type calcium current (ICa-L) in normal and hypertrophied myocytes.Methods. Forty male rats were randomly divided into two groups: the control group and the transverse aortic constriction- (TAC-) induced heart failure group. Cardiac hypertrophy was induced by TAC surgery, whereas the control group underwent a sham operation. Eight weeks after surgery, single cardiac ventricular myocytes were isolated from the hearts of the rats. The APs andICa-Lwere recorded using the whole-cell patch clamp technique.Results. The action potential duration (APD) of the TAC group was prolonged compared with the control group and was markedly shortened by WXKL treatment in a dose-dependent manner. The current densities of theICa-Lin the TAC group treated with 5 g/L WXKL were significantly decreased compared with the TAC group. We also determined the effect of WXKL on the gating mechanism of theICa-Lin the TAC group. We found that WXKL decreased theICa-Lby accelerating the inactivation of the channels and delaying the recovery time from inactivation.Conclusions. The results suggest that WXKL affects the AP and blocked theICa-L, which ultimately resulted in the treatment of arrhythmias.

Velvet antler of deer (VAD) is a commonly-used kidney-Yang supplementing traditional Chinese medication. According to the heart-kidney-related theory, heart Yang originates in kidney Yang and heart failure due to heart Yang deficiency can be treated by tonifying kidney Yang. In this study, we investigated therapeutic effects of VAD on cardiac functions in rats with heart failure following myocardial infarction. Forty-eight male Wistar rats were subjected either to left coronary artery ligation (N=36) or to sham operation (N=12). One week after the surgery, rats with heart failure received daily treatment of double-distilled water, captopril or VAD by gavage for consecutively four weeks, while sham-operated animals were given double-distilled water. Ultrasonic echocardiography was adopted to examine cardiac structural and functional parameters and serum brain natriuretic peptide (BNP) concentration was measured using radioimmunoassay. We found that VAD partially reversed changes in cardiac functional parameters and serum BNP levels in rats with heart failure. These results provide further evidence for the heart-kidney-related theory and suggest that VAD might be a potentially alternative and complementary medicine for the treatment of heart failure.