A review of big data technology and its application in cancer care.

The development of modern medical devices and information technology has led to a rapid growth in the amount of data available for health protection information, with the concept of medical big data emerging globally, along with significant advances in cancer care relying on data-driven approaches. However, outstanding issues such as fragmented data governance, low-quality data specification, and data lock-in still make sharing challenging. Big data technology provides solutions for managing massive heterogeneous data while combining artificial intelligence (AI) techniques such as machine learning (ML) and deep learning (DL) to better mine the intrinsic connections between data. This paper surveys and organizes recent articles on big data technology and its applications in cancer, dividing them into three different types to outline their primary content and summarize their critical role in assisting cancer care. It then examines the latest research directions in big data technology in cancer and evaluates the current state of development of each type of application. Finally, current challenges and opportunities are discussed, and recommendations are made for the further integration of big data technology into the medical industry in the future.

A Review about C-TIRADS, ACR-TIRADS, and K-TIRADS Combined with Real-Time Tissue Elastography to Diagnose Thyroid Nodules.

PURPOSE: This study aimed to evaluate the diagnostic efficiency of the Chinese version of thyroid imaging reporting and data system (C-TIRADS), American College of Radiology (ACR)-TIRADS, and Korean (K)-TIRADS combined with real-time tissue elastography to diagnose thyroid nodules. METHODS: A total of 574 thyroid nodule ultrasonographic images were retrospectively analyzed and classified based on the three TIRADS methods. The MedCale statistical software was used to construct the receiver operating characteristic (ROC) curve based on the pathological results of surgery. The diagnostic efficiency before and after assessing elastographies from the three TIRADS was compared between C-TIRADS, ACR-TIRADS, and K-TIRADS groups and within before and after TIRADS combined with elastic imaging. Furthermore, the unnecessary biopsy rates were also compared. Comparing area under ROC curve (AUC) with MEDCALC software (20.0.15, MedCalc Software Ltd., Ostend, Belgium), Delong test was used. The sensitivity and specificity were compared by STATA software (15.1, StataCorp LP, College Station, TX, USA) and Chi-square test. The rate of unnecessary biopsy was compared by SPSS software (23.0, IBM, Armonk, NY, USA) and Chi-square test. RESULTS: C-TIRADS, ACR-TIRADS, K-TIRADS cut-off values, and real-time tissue elastography (RTE) were 4b, 5, 5, and 3, respectively, and the areas under the ROC curve were 0.932, 0.914, 0.904, and 0.883, respectively. C-TIRADS had the highest AUC (p < 0.05) and sensitivity (p < 0.001), while ACR-TIRADS had the highest specificity (p < 0.001). After conducting a combined elastography with the three TIRADS, AUC showed increases of different degrees. Comparing TIRADS with TIRADS+RTE, the difference of C-TIRADS had statistical significance (p < 0.001), but the difference of ACR-TIRADS and K-TIRADS had no statistical significance (p > 0.05). The unnecessary biopsy rate showed decreases of different degrees. Differences between C-TIRADS and K-TIRADS were significant (p < 0.05), but in the case of ACR-TIRADS were not significant (p > 0.05). CONCLUSIONS: C-TIRADS, ACR-TIRADS, K-TIRA and RTE showed high diagnostic efficiency, with C-TIRADS having the highest. Real-time tissue elastography can improve TIRADS diagnostic efficiency and reduce its unnecessary biopsy rate. In this case C-TIRADS showed again the highest efficiency.

AlphaFold accelerates artificial intelligence powered drug discovery: efficient discovery of a novel CDK20 small molecule inhibitor.

The application of artificial intelligence (AI) has been considered a revolutionary change in drug discovery and development. In 2020, the AlphaFold computer program predicted protein structures for the whole human genome, which has been considered a remarkable breakthrough in both AI applications and structural biology. Despite the varying confidence levels, these predicted structures could still significantly contribute to structure-based drug design of novel targets, especially the ones with no or limited structural information. In this work, we successfully applied AlphaFold to our end-to-end AI-powered drug discovery engines, including a biocomputational platform PandaOmics and a generative chemistry platform Chemistry42. A novel hit molecule against a novel target without an experimental structure was identified, starting from target selection towards hit identification, in a cost- and time-efficient manner. PandaOmics provided the protein of interest for the treatment of hepatocellular carcinoma (HCC) and Chemistry42 generated the molecules based on the structure predicted by AlphaFold, and the selected molecules were synthesized and tested in biological assays. Through this approach, we identified a small molecule hit compound for cyclin-dependent kinase 20 (CDK20) with a binding constant Kd value of 9.2 ± 0.5 µM (n = 3) within 30 days from target selection and after only synthesizing 7 compounds. Based on the available data, a second round of AI-powered compound generation was conducted and through this, a more potent hit molecule, ISM042-2-048, was discovered with an average Kd value of 566.7 ± 256.2 nM (n = 3). Compound ISM042-2-048 also showed good CDK20 inhibitory activity with an IC50 value of 33.4 ± 22.6 nM (n = 3). In addition, ISM042-2-048 demonstrated selective anti-proliferation activity in an HCC cell line with CDK20 overexpression, Huh7, with an IC50 of 208.7 ± 3.3 nM, compared to a counter screen cell line HEK293 (IC50 = 1706.7 ± 670.0 nM). This work is the first demonstration of applying AlphaFold to the hit identification process in drug discovery.

Application of random forest based on semi-automatic parameter adjustment for optimization of anti-breast cancer drugs.

The optimization of drug properties in the process of cancer drug development is very important to save research and development time and cost. In order to make the anti-breast cancer drug candidates with good biological activity, this paper collected 1974 compounds, firstly, the top 20 molecular descriptors that have the most influence on biological activity were screened by using XGBoost-based data feature selection; secondly, on this basis, take pIC50 values as feature data and use a variety of machine learning algorithms to compare, soas to select a most suitable algorithm to predict the IC50 and pIC50 values. It is preliminarily found that the effects of Random Forest, XGBoost and Gradient-enhanced algorithms are good and have little difference, and the Support vector machine is the worst. Then, using the Semi-automatic parameter adjustment method to adjust the parameters of Random Forest, XGBoost and Gradient-enhanced algorithms to find the optimal parameters. It is found that the Random Forest algorithm has high accuracy and excellent anti over fitting, and the algorithm is stable. Its prediction accuracy is 0.745. Finally, the accuracy of the results is verified by training the model with the preliminarily selected data, which provides an innovative solution for the optimization of the properties of anti- breast cancer drugs, and can provide better support for the early research and development of anti-breast cancer drugs.

Plasma lncRNA LOC338963 and mRNA AP3B2 are upregulated in paraneoplastic Lambert-Eaton myasthenic syndrome.

INTRODUCTION/AIMS: Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune neuromuscular junction disorder. Long noncoding RNA (lncRNA) can regulate the expression of mRNA and is involved in the development of autoimmune diseases, but few genetic studies are available. In this study we aimed to explore the lncRNA and mRNA changes of LEMS. METHODS: Plasma lncRNA and mRNA expression profiles of three LEMS patients with small cell lung cancer (SCLC) and three matched healthy controls were analyzed by microarray. Differentially expressed lncRNAs and adjacent mRNAs were jointly analyzed, and candidates were verified by quantitative real-time polymerase chain reaction (qRT-PCR). The identified genes were subsequently evaluated in 9, 8, and 4 patients with paraneoplastic LEMS, nontumor LEMS, and SCLC, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to determine possible functions. RESULTS: A total of 320 lncRNA and 168 mRNAs were differentially expressed in the three LEMS with SCLC and compared with healthy controls. Among these, lncRNA LOC338963 and its neighboring mRNA AP3B2 were upregulated jointly, which was confirmed by qRT-PCR. qRT-PCR revealed significant upregulation of the two genes in patients with paraneoplastic LEMS compared with nontumor LEMS or SCLC. GO analysis of AP3B2 identified the enrichment terms anterograde synaptic vesicle transport and establishment of synaptic vesicle localization. KEEG analysis showed that AP3B2 was enriched in lysosomal pathways. DISCUSSION: LOC338963 and AP3B2 were upregulated in patients with paraneoplastic LEMS, suggesting their involvement in pathogenesis. These genes could be targets for exploring the pathomechanism of paraneoplastic LEMS.

The gut microbiome modulates nitroglycerin-induced migraine-related hyperalgesia in mice.

BACKGROUND: Gut microbiota disturbance is increasingly suggested to be involved in the pathogenesis of migraine but this connection remains unsubstantiated. This study aimed to investigate whether the gut microbiome influences migraine-related hyperalgesia. METHODS: Nitroglycerin-induced hyperalgesia was evaluated in mice with different gut microbiota statuses as follows: Specific pathogen-free mice; germ-free mice; specific pathogen-free mice treated with antibiotics to deplete the gut microbiome (ABX mice); and germ-free mice transplanted with the gut microbial profile from specific pathogen-free mice (GFC mice). Moreover, nitroglycerin-induced hyperalgesia was compared between recipient mice transplanted with gut microbiota from a patient with migraine and those that received gut microbiota from a sex- and age-matched healthy control. RESULTS: In specific pathogen-free mice, a decreased mechanical threshold in the hind paw, increased grooming time, increased c-Fos expression level and decreased calcitonin gene-related peptide expression level as well as increased tumor necrosis factor-α concentration in the trigeminal nucleus caudalis were observed after nitroglycerin administration compared with saline treatment. However, increased basal sensitivity and higher basal concentrations of TNF-α in the trigeminal nucleus caudalis were observed in germ-free and ABX mice, while no significant difference in hyperalgesia was observed between the nitroglycerin group and saline group in germ-free and ABX mice. Moreover, significant hyperalgesia was induced by nitroglycerin administration in GFC mice. The mice transplanted with the gut microbial profile from a patient with migraine had more severe nitroglycerin-induced hyperalgesia than the mice receiving microbiota from a matched healthy control. CONCLUSION: Our findings highlight the involvement of the gut microbiome in normal mechanical pain sensation and pathogenesis of migraine.

Functional correlation of ATP1A2 mutations with phenotypic spectrum: from pure hemiplegic migraine to its variant forms.

BACKGROUND: Mutations in ATP1A2, the gene encoding the α2 subunit of Na+/K+-ATPase, are the main cause of familial hemiplegic migraine type 2 (FHM2). The clinical presentation of FHM2 with mutations in the same gene varies from pure FHM to severe forms with epilepsy and intellectual disability, but the correlation of these symptoms with different ATP1A2 mutations is still unclear. METHODS: Ten ATP1A2 missense mutations were selected according to different phenotypes of FHM patients. They caused pure FHM (FHM: R65W, R202Q, R593W, G762S), FHM with epilepsy (FHME: R548C, E825K, R938P), or FHM with epilepsy and intellectual disability (FHMEI: T378N, G615R, D718N). After ouabain resistance and fluorescence modification, plasmids carrying those mutations were transiently transfected into HEK293T and HeLa cells. The biochemical functions were studied including cell survival assays, membrane protein extraction, western blotting, and Na+/K+-ATPase activity tests. The electrophysiological functions of G762S, R938P, and G615R mutations were investigated in HEK293T cells using whole-cell patch-clamp. Homology modeling was performed to determine the locational distribution of ATP1A2 mutations. RESULTS: Compared with wild-type pumps, all mutations showed a similar level of protein expression and decreased cell viability in the presence of 1 µM ouabain, and there was no significant difference among the mutant groups. The changes in Na+/K+-ATPase activity were correlated with the severity of FHM phenotypes. In the presence of 100 µM ouabain, the Na+/K+-ATPase activity was FHM > FHME > FHMEI. The ouabain-sensitive Na+/K+-ATPase activity of each mutant was significantly lower than that of the wild-type protein, and there was no significant difference among all mutant groups. Whole-cell voltage-clamp recordings in HEK293T cells showed that the ouabain-sensitive pump currents of G615R were significantly reduced, while those of G762S and R938P were comparable to those of the wild-type strain. CONCLUSIONS: ATP1A2 mutations cause phenotypes ranging from pure FHM to FHM with epilepsy and intellectual disability due to varying degrees of deficits in biochemical and electrophysiological properties of Na+/K+-ATPase. Mutations associated with intellectual disability presented with severe impairment of Na+/K+-ATPase. Whether epilepsy is accompanied, or the type of epilepsy did not seem to affect the degree of impairment of pump function.

Aminophylline promotes mitochondrial biogenesis in human pulmonary bronchial epithelial cells.

Recently, mitochondrial dysfunction has been linked to the development of common airway disorders, such as chronic obstructive pulmonary disease (COPD) and asthma. Phosphodiesterase inhibitors are therapeutic agents for various diseases. Aminophylline is a nonselective phosphodiesterase inhibitor used to treat common lung diseases. In this study, we show that aminophylline promotes mitochondrial biogenesis in cultured human pulmonary bronchial epithelial cells (HPBECs). Aminophylline treatment induces the expression of transcriptional coactivator PGC-1α and transcriptional factors NRF1 and TFAM. The effect of aminophylline on mitochondrial biogenesis can be revealed by its promotion of the ratio of mitochondrial DNA to nuclear DNA (mtDNA/nDNA), mitochondrial protein cytochrome B and mitochondrial mass. At the cellular level, aminophylline increases the mitochondrial respiration rate and ATP production but reduces oxygen content. Consistently, we show that aminophylline activates the CREB-PGC-1α signaling pathway to promote mitochondrial biogenesis. The inhibition of CREB activation by its specific inhibitor H89 obscures the induction of PGC-1α, NRF1, and TFAM by aminophylline, and also abolishes the action of aminophylline on the mtDNA/nDNA ratio and respiration rate, suggesting that the activation of CREB is required for the action of aminophylline. Collectively, our study supports that aminophylline is a potent metabolic inducer of mitochondrial biogenesis in epithelial cells. Aminophylline could have a therapeutic effect on epithelial mitochondrial function in lung diseases.

A Chinese family with familial hemiplegic migraine type 2 due to a novel missense mutation in ATP1A2.

BACKGROUND: ATP1A2 has been identified as the genetic cause of familial hemiplegic migraine type 2. Over 80 ATP1A2 mutations have been reported, but no data from Chinese family studies has been included. Here, we report the first familial hemiplegic migraine type 2 Chinese family with a novel missense mutation. METHODS: Clinical manifestations in the family were recorded. Blood samples from patients and the unaffected members were collected for whole-exome sequencing to identify the pathogenic mutation. Seven online softwares (SIFT, PolyPhen-2, PROVEAN, PANTHER, MutationTaster2, MutationAssessor and PMut) were used for predicting the pathogenic potential of the mutation. PredictProtein, Jpred 4 and PyMOL were used to analyze structural changes of the protein. The mutation function was further tested by Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. RESULTS: All patients in the family had typical hemiplegic migraine attacks. Co-segregation of the mutation with the migraine phenotype in four generations, with 10 patients, was completed. The identified novel mutation, G762S in ATP1A2, exhibited the disease-causing feature by all the predictive softwares. The mutation impaired the local structure of the protein and decreased cell viability. CONCLUSION: G762S in ATP1A2 is a novel pathogenic mutation identified in a Chinese family with familial hemiplegic migraine, which causes loss of function by changing the protein structure of the Na+/K+-ATPase α2 subunit.

Regulation of Intestinal Epithelial Cells Properties and Functions by Amino Acids.

Intestinal epithelial cells (IECs) line the surface of intestinal epithelium, where they play important roles in the digestion of food, absorption of nutrients, and protection of the human body from microbial infections, and others. Dysfunction of IECs can cause diseases. The development, maintenance, and functions of IECs are strongly influenced by external nutrition, such as amino acids. Amino acids play important roles in regulating the properties and functions of IECs. In this article, we briefly reviewed the current understanding of the roles of amino acids in the regulation of IECs' properties and functions in physiological state, including in IECs homeostasis (differentiation, proliferation, and renewal), in intestinal epithelial barrier structure and functions, and in immune responses. We also summarized some important findings on the effects of amino acids supplementation (e.g., glutamine and arginine) in restoring IECs' and intestine functions in some diseased states. These findings will further our understanding of the important roles of amino acids in the homeostasis of IECs and could potentially help identify novel targets and reagents for the therapeutic interventions of diseases associated with dysfunctional IECs.

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.

Deletion of ADP Ribosylation Factor-Like GTPase 13B Leads to Kidney Cysts.

The gene for ADP ribosylation factor-like GTPase 13B (Arl13b) encodes a small GTPase essential for cilia biogenesis in multiple model organisms. Inactivation of arl13b in zebrafish leads to a number of phenotypes indicative of defective cilia, including cystic kidneys. In mouse, null mutation in Arl13b results in severe patterning defects in the neural tube and defective Hedgehog signaling. Human mutations of ARL13B lead to Joubert syndrome, a ciliopathy. However, patients with mutated ARL13B do not develop kidney cysts. To investigate whether Arl13b has a role in ciliogenesis in mammalian kidney and whether loss of function of Arl13b leads to cystic kidneys in mammals, we generated a mouse model with kidney-specific conditional knockout of Arl13b Deletion of Arl13b in the distal nephron at the perinatal stage led to a cilia biogenesis defect and rapid kidney cyst formation. Additionally, we detected misregulation of multiple pathways in the cystic kidneys of this model. Moreover, valproic acid, a histone deacetylase inhibitor that we previously showed slows cyst progression in a mouse cystic kidney model with neonatal inactivation of Pkd1, inhibited the early rise of Wnt7a expression, ameliorated fibrosis, slowed cyst progression, and improved kidney function in the Arl13b mutant mouse. Finally, in rescue experiments in zebrafish, all ARL13B allele combinations identified in patients with Joubert syndrome provided residual Arl13b function, supporting the idea that the lack of cystic kidney phenotype in human patients with ARL13B mutations is explained by the hypomorphic nature of the mutations.

Mst1 and mst2 are essential regulators of trophoblast differentiation and placenta morphogenesis.

The placenta is essential for survival and growth of the fetus because it promotes the delivery of nutrients and oxygen from the maternal circulation as well as fetal waste disposal. Mst1 and Mst2 (Mst1/2), key components of the mammalian hpo/Mst signaling pathway, encode two highly conserved Ser/Thr kinases and play important roles in the prevention of tumorigenesis and autoimmunity, control of T cell development and trafficking, and embryonic development. However, their functions in placental development are not fully understood, and the underlying cellular and molecular mechanisms remain elusive. Here, we investigated the functions of Mst1/2 in mouse placental development using both conventional and conditional (endothelial) Mst1/2 double knockout mice. We found that the number of trophoblast giant cells dramatically increased while spongiotrophoblast cells almost completely disappeared in Mst1/2 deficient placentas. We showed that Mst1/2 deficiency down regulated the expression of Mash2, which is required for suppressing the differentiation of trophoblast giant cells. Furthermore, we demonstrated that endothelial-specific deletion of Mst1/2 led to impaired placental labyrinthine vasculature and embryonic lethality at E11.5, but neither affected vasculature in yolk sac and embryo proper nor endocardium development. Collectively, our findings suggest that Mst1/2 regulate placental development by control of trophoblast cell differentiation and labyrinthine vasculature at midgestation and Mst1/2 control labyrinth morphogenesis in trophoblast- and fetal endothelial-dependent manners. Thus, our studies have defined novel roles of Mst1/2 in mouse placental development.

Mst1/Mst2 regulate development and function of regulatory T cells through modulation of Foxo1/Foxo3 stability in autoimmune disease.

Foxp3 expression and regulatory T cell (Treg) development are critical for maintaining dominant tolerance and preventing autoimmune diseases. Human MST1 deficiency causes a novel primary immunodeficiency syndrome accompanied by autoimmune manifestations. However, the mechanism by which Mst1 controls immune regulation is unknown. In this article, we report that Mst1 regulates Foxp3 expression and Treg development/function and inhibits autoimmunity through modulating Foxo1 and Foxo3 (Foxo1/3) stability. We have found that Mst1 deficiency impairs Foxp3 expression and Treg development and function in mice. Mechanistic studies reveal that Mst1 enhances Foxo1/3 stability directly by phosphorylating Foxo1/3 and indirectly by attenuating TCR-induced Akt activation in peripheral T cells. Our studies have also shown that Mst1 deficiency does not affect Foxo1/3 cellular localization in CD4 T cells. In addition, we show that Mst1(-/-) mice are prone to autoimmune disease, and mutant phenotypes, such as overactivation of naive T cells, splenomegaly, and autoimmune pathological changes, are suppressed in Mst1(-/-) bone marrow chimera by cotransplanted wt Tregs. Finally, we demonstrate that Mst1 and Mst2 play a partially redundant role in Treg development and autoimmunity. Our findings not only identify Mst kinases as the long-searched-for factors that simultaneously activate Foxo1/3 and inhibit TCR-stimulated Akt downstream of TCR signaling to promote Foxp3 expression and Treg development, but also shed new light on understanding and designing better therapeutic strategies for MST1 deficiency-mediated human immunodeficiency syndrome.

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.

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.

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.

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.

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.