General physiology and biophysics最新文献

It was previously reported that the delta opioid receptor (DOR) agonist SNC80 and antagonist naltrindole modulate the excitability of hippocampal glutamate neurons in primary cultures. The present study aimed to investigate the acute effects of these ligands on the firing activity of hippocampal cornu ammonis 1/3 (CA1/3) glutamate, dorsal raphe nucleus (DRN) serotonin (5-HT), locus coeruleus (LC) noradrenaline, and ventral tegmental area (VTA) dopamine neurons in in vivo conditions. Adult Wistar male rats were used. SNC80 and naltrindole were administered intravenously. Neuronal firing activity was assessed using extracellular single-unit electrophysiology. SNC80, administered first at 1-3 mg/kg, dose-dependently inhibited CA1/3 glutamate, DRN 5-HT, and VTA dopamine neurons. Naltrindole, administered at 1-3 mg/kg after SNC80, did not have any additional effect. Naltrindole, administered first at 1-3 mg/kg, stimulated DRN 5-HT neurons in a dose-dependent manner; this stimulation was dose-dependently reversed by 1-3 mg/kg of SNC80. SNC80 and naltrindole inhibited LC noradrenaline neurons when only they were co-administered at 3 mg/kg, and only when SNC80 was administered first. In conclusion, DOR ligands alter the firing activity of hippocampal glutamate and brainstem monoamine neurons in in vivo conditions. The psychoactive effects of DOR ligands, reported in previous studies, might be explained, at least in part, by their ability to modulate the firing activity of hippocampal glutamate and brainstem monoamine neurons.

Fifty-four obese patients with non-alcoholic fatty liver disease (NAFLD) were selected for this study were randomly divided into an exercise group (16 men and 11 women, mean age 21.3 ± 1.0) and control group (16 men and 11 women, mean age 21.8 ± 0.8). The exercise group underwent a 12-week FATmax exercise intervention, while the control group did not engage in any type of systematic physical activity. The controlled diet was given to both groups. After the test, the microvascular reactivity of the exercise group was significantly higher than that of the control group (p < 0.05). After the experiment, the concentration of malondialdehyde (MDA), the activity of catalase (CAT) and the activity of exercise group were significantly lower than those of the control group (p < 0.05); and in contrast the activities of total superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) were significantly higher than those of the control group (p< 0.05). The change in microcirculation function caused by 12-week FATmax intensity exercise may have an interaction mechanism with oxidative stress and antioxidant system function, and may improve the microvascular reactivity of obese NAFLD patients. In addition, also may improve of oxidative stress and antioxidant system functions.

This study examined the effect of chloroquine on vasodilation induced by levcromakalim in isolated endothelium-denuded rat aortas and clarified the underlying mechanisms. We examined the effects of chloroquine, hydroxychloroquine, lipid emulsion, reactive oxygen species (ROS) scavenger N-acetyl-ʟ-cysteine (NAC), and KATP channel inhibitor glibenclamide on levcromakaliminduced vasodilation. The effects of chloroquine, hydroxychloroquine, NAC, and levcromakalim on membrane hyperpolarization and ROS production were examined in aortic vascular smooth muscle cells (VSMCs). Chloroquine inhibited levcromakalim-induced vasodilation more than hydroxychloroquine. NAC attenuated chloroquine-mediated inhibition of levcromakalim-induced vasodilation, while lipid emulsion had no effect. Glibenclamide eliminated levcromakalim-induced vasodilation in aortas pretreated with chloroquine. Chloroquine and hydroxychloroquine inhibited levcromakalim-induced membrane hyperpolarization in VSMCs. Chloroquine and hydroxychloroquine both produced ROS, but chloroquine produced more. NAC inhibited chloroquine-induced ROS production in VSMCs. Collectively, these results suggest that, partially through ROS production, chloroquine inhibits levcromakalim-induced vasodilation. In addition, chloroquine-induced KATP channel-induced vasodilation impairment was not restored by lipid emulsion.

Glutamine is proven to have potential therapeutic effects on decreasing hyperoxia-induced acute pulmonary injury. The aim of this study is to investigate the effects and mechanism of glutamine on bronchopulmonary dysplasia (BPD) induced by hyperoxia in rat alveolar type II epithelial cells (AECIIs) RLE-6TN. Following hyperoxia induction and glutamine treatment, ROS levels were detected by DCFH-DA assay and TUNEL staining was performed to detect cell apoptosis. The levels of inflammatory indicators and expression of apoptosis-related proteins were detected through ELISA and Western blot, respectively. Besides, the expression of related proteins in mitogen-activated protein kinase phosphatase-1 (MKP-1)/mitogen-activated protein kinases (MAPK)/cytoplasmic phospholipase A2 (cPLA2) signaling was also detected by Western blot. To further analyze the role of MKP-1/MAPK/cPLA2 signaling, MKP-1 was silenced and anisomycin was used to treat cells, respectively. It was shown that glutamine significantly decreased inflammation, oxidative stress and apoptosis in hyperoxia-induced cells while MKP-1 interference and anisomycin were able to reverse these effects, suggesting that the protective effects of glutamine on BPD induced by hypoxia were related to MKP-1/MAPK/cPLA2 signaling. To sum up, glutamine protected against BPD by decreasing inflammation, oxidative stress and apoptosis via MKP-1/MAPK/cPLA2 signaling.

In this study, we have screened genes involved in myocardial hypertrophy (MH) using a mice model for compensatory stress overload (transverse aortic constriction, TAC) and bioinformatics. Microarrays were downloaded, and according to the Venn diagram, three groups of data intersections were obtained. Gene function was analyzed by Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), whereas protein-protein interactions (PPI) were analyzed using the STRING database. A mouse aortic arch ligation model was established to verify and screen the expression of hub genes. A total of 53 (DEGs) and 32 PPI genes were screened out. GO analysis showed DEGs mainly involved in cytokine and peptide inhibitor activity. KEGG analysis focused on ECM receptor interaction and osteoclast differentiation. Expedia co-expression gene network analysis showed that Serpina3n, Cdkn1a, Fos, Col5a2, Fn1 and Timp1 participated in the occurrence and development of MH. RT-qPCR verified that all the other 9 hub genes except Lox were highly expressed in TAC mice. This study lays a foundation for further study on the molecular mechanism of MH and for screening of molecular markers.

The mechanisms orchestrating the balance between nitric oxide and endothelium-derived contracting factors, and genetic predisposition to endothelial dysfunction in hypertensive patients remain to be determined. One-hundred hypertensive patients participated in the case-control study to clarify the risk of endothelial dysfunction and carotid "intima media" thickness (IMT) changes depending on NOS3 (rs2070744) and GNB3 (rs5443) genes' polymorphisms. It is found that presence of NOS3 gene's С-allele significantly elevates the risk of atherosclerotic plaques on carotid arteries (OR95%CI: 1.24-11.20; р = 0.019) and the probability of low NOS3 gene expression (OR95%CI: 17.72-520.0; р < 0.001). Homozygous carriage of С-allele of GNB3 gene is protective and corresponds to the lowest chances of the carotid IMT increase, atherosclerotic plaques formation and sVCAM-1 elevation (OR = 0.10-0.34; OR95%CI: 0.03-0.95; р ≤ 0.035-0.001). Vice versa, Т-allele of GNB3 gene significantly augments the risk of the carotid IMT increase (OR95%CI: 1.09-7.74; р = 0.027) including development of atherosclerotic plaques, associating GNB3 (rs5443) with cardiovascular pathology.

Deep hypothermia with low flow perfusion (DHLF) is a common cardiopulmonary bypass (CPB) technique. The associated lung ischemia/reperfusion injury is a major cause of postoperative morbidity and mortality in patients undergoing DHLP; we aimed to investigate the effects of nuclear factor-κB (NF-κB) inhibitor pyrrolidine dithiocarbamate (PDTC) with continuous perfusion of pulmonary arteries (CPP) on DHLF-induced lung injury and the related molecular mechanisms. Twenty-four piglets were randomly divided into the DHLF (control), CPP (with DHLF), or CPP+PDTC (intravenous PDTC before CPP with DHLF) groups. Lung injury was evaluated by respiratory function measurement, lung immunohistochemistry, and serum levels of TNF, IL-8, IL-6, and NF-κB before CPB, at CPB completion, and at 1 h post-CPB. Western blot was used to detect NF-κB protein expression in lung tissues. After CPB, decreased parcial pressure of oxygen (PaO2) and increased parcial pressure of carbon dioxide (PaCO2) and serum levels of TNF, IL-8, IL-6, and NF-κB were observed in the DHLF group. Both CPP and CPP+PDTC groups showed better indices of lung function, decreased levels of TNF, IL-8, and IL-6, and less severe pulmonary edemas and injuries. PDTC with CPP further improved pulmonary function and mitigated pulmonary injury than did CPP alone. PDTC with CPP better attenuates DHLF-induced lung injury than does CPP alone.

Studies have found that cardiomyocytes and cardiac fibroblasts (CFs) can communicate through exosomes, thereby affecting each other's biological functions, but there are few studies on the mechanism. miR-208a/b are specifically expressed in the heart and highly expressed in exosomes derived from various myocardial diseases. Hypoxia induced cardiomyocytes to secrete exosomes (H-Exo) with high expression of miR-208a/b. When H-Exo were added to CFs for co-culture, it was found that CFs took up exosomes, thereby upregulating the expression of miR-208a/b. H-Exo significantly promoted the viability and migration of CFs, enhanced the expression of α-SMA, collagen I and III, and promoted the secretion of collagen I and III. miR-208a or/and miR-208b inhibitors significantly attenuated the effects of H-Exo on CF biological functions. miR-208a/b inhibitors significantly enhanced the levels of apoptosis and caspase-3 activity in CFs, while H-Exo significantly attenuated the pro-apoptotic effects of miR-208a/b inhibitors. Further treatment of CFs with ferroptosis inducer Erastin found that H-Exo further enhanced the accumulation of ROS, MDA and Fe2+, the main indicators of ferroptosis, and inhibited the expression of GPX4, a key regulator of ferroptosis. miR-208a or/and miR-208b inhibitors significantly attenuated the effects of Erastin and H-Exo on ferroptosis. In conclusion, hypoxic cardiomyocyte-derived exosomes can regulate the biological functions of CFs through highly expressed miR-208a/b.

Major depressive disorder is a very common serious mental illness with increasing prevalence in the population. Its pathology includes biochemical, morphological, and electrophysiological changes in various brain areas. In spite of decades of extensive research pathophysiology of depression is still not sufficiently understood. When depression occurs just before or during pregnancy, it may have a detrimental effect on perinatal and/or postnatal brain development, affecting the offspring's behavior. An important role in the pathology of depression is the hippocampus as a center for cognition and memory. Here we review changes in morphology, biochemical, and electrical signaling caused by depression in first and second generation identified in various animal models.

Long non-coding RNAs (lncRNAs) are involved in the development of myocardial ischemia/reperfusion injury (MIRI). In this study, we aimed to explore the regulatory effect and mechanism of lncRNA SOX2-overlapping transcript (SOX2-OT) in MIRI. The viability of oxygen and glucose deprivation/reperfusion (OGD/R)-treated H9c2 cells was detected by MTT assay. The levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, malondialdehyde (MDA), and superoxide dismutase (SOD) were measured by ELISA. The target relationship between SOX2-OT and miR-146a-5p was predicted by LncBase, and subsequently confirmed by Dual luciferase reporter assay. The effects of SOX2-OT silencing on myocardial apoptosis and function were further validated in MIRI rats. The expression of SOX2-OT was increased in OGD/R-treated H9c2 cells and myocardial tissues of MIRI rats. Silencing of SOX2-OT increased the viability and inhibited the inflammation and oxidative stress of OGD/R-treated H9c2 cells. SOX2-OT negatively regulated its target miR-146a-5p. Silencing of miR-146a-5p reversed the effects of sh-SOX2-OT on OGD/R-treated H9c2 cells. In addition, silencing of SOX2-OT also alleviated myocardial apoptosis and improved myocardial function in MIRI rats. Silencing of SOX2-OT relieved the apoptosis, inflammation, and oxidative stress of myocardial cells via up-regulating miR-146a-5p, contributing to the remission of MIRI.