Pyridostigmine ameliorates cardiac remodeling induced by myocardial infarction via inhibition of the transforming growth factor-ß1/TGF-ß1-activated kinase pathway.

Autonomic imbalance characterized by sympathetic predominance coinciding with diminished vagal activity is an independent risk factor in cardiovascular diseases. Several studies show that vagus nerve stimulation exerted beneficial effects on cardiac function and survival. In this study, we investigated the vagomimetic effect of pyridostigmine on left ventricular (LV) remodeling in rats after myocardial infarction. After myocardial infarction, surviving rats were treated with or without pyridostigmine (31 mg·kg⁻¹·d⁻¹) for 2 weeks, and hemodynamic parameters were measured. LV tissue was used to assess infarct size and interstitial fibrosis by Masson's trichrome and 0.1% picrosirius red staining. Protein expression of heart tissues was used to assess the efficacy of the treatment. Pyridostigmine markedly reduced myocardial infarct size and improved cardiac diastolic function. These improvements were accompanied with a significant decrease in matrix metalloproteinase-2 expression and collagen deposition. Additionally, pyridostigmine inhibited both transforming growth factor-ß1 (TGF-ß1) and TGF-ß1-activated kinase expression in hearts postmyocardial infarction. Thus, pyridostigmine reduces collagen deposition, attenuates cardiac fibrosis, and improves LV diastolic function after myocardial infarction via TGF-ß1/TGF-ß1-activated kinase pathway inhibition.

Stop Ischemic Event to the Brain: Screening Risk Factors of Cerebrovascular Stenosis in Coronary Artery Disease Patients.

OBJECTIVES: In this study, we investigated the difference in risk factors between the 2 diseases, aiming to further clarify who needs to do ischemic cerebrovascular disease (ICVD)-related screening among coronary artery disease (CAD) patients. METHODS: Clinical data of 326 patients with first-episode CAD from June 1, 2017, to July 31, 2020, in the Chinese PLA General Hospital were retrospectively reviewed. Outcomes, including clinical features and laboratory examination, were taken. Features related to ICVD including the extension of intracranial arterial (internal carotid artery intracranial segment, middle cerebral artery M1 segment, anterior cerebral A1 segment, vertebrobasilar artery intracranial segment, posterior cerebral artery P1 segment) and carotid arterial (internal carotid artery extracranial segment, common carotid artery, subclavian artery) stenosis were detected. Risk factors for the occurrence of ICVD in patients with CAD were analyzed. RESULTS: Among patients with the onset of CAD, in comparison of the nonstenosis and stenosis of intracranial artery subgroups, there were statistical differences in the onset age, hypertension, and duration of hypertension as well as the biochemical indicators, including high-density lipoprotein and glycosylated hemoglobin. In addition, statistical differences were detected in the onset age as well as the biochemical indicators, including glycosylated hemoglobin and blood glucose serum protein, along with the difference in the degree of cardiovascular stenosis. CONCLUSIONS: The onset age of CAD was shown to serve as a vital risk factor for ICVD. The primary prevention of ICVD in patients with CAD should lay more emphasis on the management of hypertension and diabetes.

Protection against ischemia-induced oxidative stress conferred by vagal stimulation in the rat heart: involvement of the AMPK-PKC pathway.

Reactive oxygen species (ROS) production is an important mechanism in myocardial ischemia and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is one of major sources of ROS in the heart. Previous studies showed that vagus nerve stimulation (VNS) is beneficial in treating ischemic heart diseases. However, the effect of VNS on ROS production remains elusive. In this study, we investigated the role of VNS onischemia-induced ROS production. Our results demonstrated that VNS alleviated the myocardial injury, attenuated the cardiac dysfunction, reserved the antioxidant enzyme activity and inhibited the formation of ROS as evidenced by the decreased NADPH oxidase (Nox) activity and superoxide fluorescence intensity as well as the expression of p67phox, Rac1 and nitrotyrosine. Furthermore, VNS resulted in the phosphorylation and activation of adenosine monophosphate activated protein kinase (AMPK), which in turn led to an inactivation of Nox by protein kinase C (PKC); however, the phenomena were repressed by the administration of a muscarinic antagonist atropine. Taken together, these data indicate that VNS decreases ROS via AMPK-PKC-Nox pathway; this may have potential importance for the treatment of ischemic heart diseases.

Acetylcholine prevents angiotensin II-induced oxidative stress and apoptosis in H9c2 cells.

Apoptosis of cardiomyocytes plays an important role in the development of cardiovascular diseases (CVD). Numerous studies have shown that generation of reactive oxygen species (ROS) induced by the renin-angiotensin system (RAS) is involved in this pathological process. Recent studies also suggested that acetylcholine (ACh) prevented the hypoxia-induced apoptosis of mouse ES cells by inhibiting the ROS production. However, whether ACh can inhibit the action of angiotensin II (Ang II) and subsequently prevent CVD development remains unclear. In this study, H9c2 cells were stimulated by 10(-6) M Ang II for 24 h with or without 10(-5) M ACh, 10(-5) M ACh + 10(-4) M atropine respectively. The results demonstrated that Ang II increased apoptosis index by fourfold (vs. the control group, P < 0.01), which were significantly diminished by ACh. However, the atropine (ACh receptor [AChR] inhibitor) treatment blocked the protective effect of ACh. Subsequently, Ang II significantly increases the expression and activity of NADPH oxidase so that ROS production is increased by sevenfold (vs. control group, P < 0.01). The activity and expression of caspase-3 along with the Bax/Bcl2 ratio and the levels of p38 mitogen activated protein kinase (MAPK) phosphorylation also appeared to follow a similar trend. Furthermore, we observed that ACh could reduce up-regulation of AT1 receptor expression induced by Ang II. However, all these effects of ACh were inhibited by atropine. In conclusion, ACh prevents Ang II-induced H9c2 cells apoptosis through down-regulation of the AT1 receptor and inhibition of ROS-mediated p38 MAPK activation as well as regulation of Bcl-2, Bax and caspase-3.

Tumour necrosis factor-α and its receptors in the beneficial effects of vagal stimulation after myocardial infarction in rats.

1. Acute myocardial infarction (AMI) often activates the sympathetic system and inhibits the vagal system. Long-term vagal nerve stimulation (VNS) exerts several beneficial effects on the ischaemic heart, including an anti-inflammatory effect. The aim of the present study was to investigate whether short-term VNS during AMI could inhibit tumour necrosis factor (TNF)-α expression and the effect of TNF receptor (TNFR), key components in inflammatory responses to AMI, in a rodent model. 2. Adult male Sprague-Dawley rats were divided into four groups, namely a control (C), VNS (S), AMI (M) and an AMI group subjected to prior VNS (MS). In the S and MS groups, the right vagus nerve was stimulated electrically for 4 h; in the M and MS groups, AMI was induced by occlusion of the left anterior descending coronary artery. Haemodynamic data were monitored continuously using a multichannel physiological recorder. Lactate dehydrogenase (LDH) leakage, creatine kinase (CK) leakage and infarct size were determined. The expression of TNF-α and its receptors were analysed by reverse transcription-polymerase chain reaction, western blotting and ELISA. 3. Compared with the control group, rats in the M group had low blood pressure, high left ventricular (LV) end-diastolic pressure, a depressed maximum dP/dt of LV pressure, higher LDH and CK leakage, a larger infarct size, increased TNF-α levels and an increased TNFR1/TNFR2 ratio. However, these presumably harmful effects of AMI were all significantly ameliorated by VNS during AMI (MS group). 4. In conclusion, VNS can rectify ischaemia-induced cardiac dysfunction partly via inhibition of a TNF-α-mediated signalling pathway.

Vasorelaxant effect of isopropyl 3-(3, 4-dihydroxyphenyl)-2-hydroxypropanoate, a novel metabolite from Salvia miltiorrhiza, on isolated rat mesenteric artery.

The present study was designed to investigate the relaxant effect of isopropyl 3-(3, 4-dihydroxyphenyl)-2-hydroxypropanoate (IDHP), a new metabolite from Salvia miltiorrhiza, on rat mesenteric artery. Isolated mesenteric arterial rings were mounted in organ baths and the isometric tension changes were measured continuously by a sensitive myograph system. The results showed that IDHP at concentrations greater than 0.1 nM produced a concentration-dependent relaxation of artery contracted by norepinephrine with pEC(50) of 7.41+/-0.08. Removal of the endothelium did not affect this relaxation, suggesting that IDHP exerted a direct effect on vascular smooth muscle cells. Meanwhile, the vasorelaxant effect of IDHP was unaffected by pre-treatment with ATP-sensitive K(+) channel inhibitor glibenclamide, delayed rectifier K(+) channel inhibitor 4-aminopyridine, inwardly rectifying K(+) channel inhibitor barium chloride and beta-adrenoceptor antagonist propranolol. However, the non-specific K(+) channel inhibitor tetraethylammonium (TEA, 3 mM) produced a rightward shift of 1.8 fold on the concentration-response curve of IDHP. Moreover, IDHP shifted the concentration-response curve of CaCl(2) as well as two receptor-mediated constrictors, phenylephrine and 5-hydroxytryptamine, to the right in a non-parallel manner. In the absence of extracellular Ca(2+), IDHP depressed the contractions induced by norepinephrine and CaCl(2), and the maximal inhibitions were 48.3+/-18.9% and 58.4+/-10.9%, respectively. These results suggest that IDHP exerts a vasorelaxant effect by inhibiting both Ca(2+) release from intracellular stores and Ca(2+) influx through voltage-dependent calcium channels, and receptor-operated calcium channels in vascular smooth muscle cells. In addition, activation of vascular TEA-sensitive K(+) channels may be partially involved in the relaxant effect of IDHP.

Role of piwi-interacting RNA-651 in the carcinogenesis of non-small cell lung cancer.

Piwi-interacting RNAs (piRNAs/piRs) are small non-coding RNAs that can serve important roles in genome stability by silencing transposable genetic elements. piR651, one of these novel piRNAs, regulates a number of biological functions, as well as carcinogenesis. Previous studies have reported that piR651 is overexpressed in human gastric cancer tissues and in several cancer cell lines, including non-small cell lung cancer (NSCLC) cell lines. However, the role of piRNAs in carcinogenesis has not been clearly defined. In the present study, a small interfering RNA inhibitor of piR651 was transfected into the NSCLC A549 and HCC827 cell lines to evaluate the effect of piR651 on cell growth. The association between piR651 expression and apoptosis was evaluated by flow cytometry and western blot analysis. Wound-healing and Transwell migration and invasion assays were used to determine the effect of piR651 on the migration and invasion of NSCLC cell lines. The results revealed that inhibition of piR651 inhibited cell proliferation and significantly increased the apoptotic rate compared with the negative control (NC), as well as altering the expression of apoptosis-associated proteins. There were fewer migrating and invading cells in the piR651-inhibited group than in the NC group in the Transwell assays. Furthermore, in the wound-healing assay, the wound remained wider in the piR651 inhibitor group, suggesting decreased cell migration compared with that in the NC group. The results of the present study demonstrate that piR651 potentially regulates NSCLC tumorigenic behavior by inhibiting cell proliferation, migration and invasion and by inducing apoptosis. Therefore, piR651 is a potential cancer diagnosis marker.

Optimizing the parameters of vagus nerve stimulation by uniform design in rats with acute myocardial infarction.

Vagus nerve stimulation (VNS) has been shown to improve left ventricular function and survival in rats with acute myocardial infarction (AMI), and this maneuver has also been adopted clinically for the treatment of patients with chronic heart failure (CHF). Recent in vitro and in vivo studies have suggested that VNS can modulate the level of pro-inflammatory factors. Despite the beneficial effects of VNS, the stimulation parameters for obtaining favorable outcomes appear highly variable. To optimize VNS parameters, we set up different stimulation protocols with different pulse width (1-2 ms), frequency (1-6 Hz), voltage (1-6 V) and duration (40-240 min) of VNS by uniform design (UD). Rats were divided into seven groups with (Group1-Group6) or without VNS (MI group). Our results demonstrate that (1) the parameter sets in Group1, Group2 and Group3 yield the best post-MI protection by VNS, while the protective role were not observed in Group4, Group5 and Group6; (2) baroreflex sensitivity and the α7 nicotinic acetylcholine receptor level were also increased in Group1, Group2 and Group3. (3) the parameter set in Group1 (G1:1 ms, 2 Hz, 3 V, 240 min) is judged the most optimal parameter in this study as rats in this group not only showed a reduced myocardial injury with better-preserved cardiac function compared with other groups, more important, but also exhibited minimal heart rate (HR) reduction. (4) the duration of VNS plays an important role in determining the protection effect of VNS. In conclusion, VNS displays a beneficial role in Group1, Group2 and Group3. Of note, the parameter set in Group1 provides the most optimal cardioprotective effect. These results may provide insight into development of novel treatment for ischemic heart diseases.

Protective mechanism of adenosine to the rat arterial endothelial dysfunction induced by hydrogen peroxide.

This study was designed to examine the in vitro effects of adenosine (Ado) on hydrogen peroxide-induced endothelial dysfunction in rats. Endothelial dysfunction was induced by exposing isolated rat mesenteric arteries to hydrogen peroxide (0.5 mM) for 12 h using an organ culture system. The protective effects of adenosine were tested by exposing isolated mesenteric arteries to adenosine (3 x 10(-7) mol/l, 10(-6) mol/l, 3 x 10(-6) mol/l)+hydrogen peroxide (0.5 mM) for 12 h. This exposure to hydrogen peroxide induced a significant concentration-dependent inhibition of endothelium-dependent relaxation (EDR). Coculture of segments of mesenteric artery with adenosine (3 x 10(-7), 10(-6), and 3 x 10(-6) mol/l) attenuated the hydrogen peroxide-induced impairment of vasorelaxation. This impairment was accompanied by a reduction in nitrite/nitrate, nitric oxide (NO) synthase (NOS), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and an increasing in malondislehyde (MDA) and lactate dehydrogenase (LDH) activities in the aorta. These results indicate that adenosine can be used to attenuate hydrogen peroxide-induced endothelial dysfunction, an effect that may be related to antioxidation, thus enhancing NO production by preventing the decrease in NOS.