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Aims: Type 2 diabetes mellitus (T2DM) is related to an increased risk of postoperative cognitive dysfunction (POCD), which may be caused by neuronal hyperexcitability. Astrocyte glutamate transporter 1 (GLT‐1) plays a crucial role in regulating neuron excitability. We investigated if T2DM would magnify the increased neuronal excitability induced by anesthesia/surgery (A/S) and lead to POCD in young adult mice, and if so, determined whether these effects were associated with GLT‐1 expression. Methods: T2DM model was induced by high fat diet (HFD) and injecting STZ. Then, we evaluated the spatial learning and memory of T2DM mice after A/S with the novel object recognition test (NORT) and object location test (OLT). Western blotting and immunofluorescence were used to analyze the expression levels of GLT‐1 and neuronal excitability. Oxidative stress reaction and neuronal apoptosis were detected with SOD2 expression, MMP level, and Tunel staining. Hippocampal functional synaptic plasticity was assessed with long‐term potentiation (LTP). In the intervention study, we overexpressed hippocampal astrocyte GLT‐1 in GFAP‐Cre mice. Besides, AAV‐Camkllα‐hM4Di‐mCherry was injected to inhibit neuronal hyperexcitability in CA1 region. Results: Our study found T2DM but not A/S reduced GLT‐1 expression in hippocampal astrocytes. Interestingly, GLT‐1 deficiency alone couldn't lead to cognitive decline, but the downregulation of GLT‐1 in T2DM mice obviously enhanced increased hippocampal glutamatergic neuron excitability induced by A/S. The hyperexcitability caused neuronal apoptosis and cognitive impairment. Overexpression of GLT‐1 rescued postoperative cognitive dysfunction, glutamatergic neuron hyperexcitability, oxidative stress reaction, and apoptosis in hippocampus. Moreover, chemogenetic inhibition of hippocampal glutamatergic neurons reduced oxidative stress and apoptosis and alleviated postoperative cognitive dysfunction. Conclusions: These findings suggest that the adult mice with type 2 diabetes are at an increased risk of developing POCD, perhaps due to the downregulation of GLT‐1 in hippocampal astrocytes, which enhances increased glutamatergic neuron excitability induced by A/S and leads to oxidative stress reaction, and neuronal apoptosis. [ABSTRACT FROM AUTHOR]

Atherosclerosis is an important underlying pathology of cardiovascular diseases. The aim of this study was to observe the expression of salusin-β, a new vasoactive peptide, in vascular tissues of low-density lipoprotein receptor deficient ([LDLR.sup.-/-]) mice, and to evaluate the effect of salusin-β on the development of atherosclerosis in [LDLR.sup.-/-] mice. Six-week-old, male [LDLR.sup.-/-] mice were subcutaneously injected with salusin-β or the vehicle, once a day for 12 weeks. The expressions of salusin-β in both mRNA and peptide levels were determined by reverse transcription--polymerase chain reaction, Western blot, and immunohistochemistry. Atherosclerotic lesions were analyzed by staining with hematoxylin and eosin or oil red O. Our results showed that expression of salusin-β in mRNA and salusin-β peptide levels were enhanced in [LDLR.sup.-/-] mice. Subcutaneous injection of salusin-β significantly aggravated the atherosclerotic lesions, and increased lipid deposits in the arteries of [LDLR.sup.-/-] mice. Moreover, salusin-β significantly increased the serum level of low-density lipoprotein cholesterol, but not total cholesterol, triglycerides, or high-density lipoprotein cholesterol. These results suggest that the enhanced expression of salusin-β contributes to progression of atherosclerosis in [LDLR.sup.-/-] mice by up-regulating the serum low-density lipoprotein cholesterol level. This study provides a potential therapeutic target for the prevention and treatment of atherosclerosis. Key words: atherosclerosis, salusin-β, peptide, mice. L'atherosclerose est une pathologie importante, sous-jacente aux maladies cardiovasculaires. Le but de cette etude etait d'observer l'expression de la salusine-β, un nouveau peptide vasoactif, dans les tissus vasculaires de souris depourvues de recepteur des lipoproteines de faible densite (LDLR -/-). Des souris males [LDLR.sup.-/-] de 6 semaines ont recu une injection sous-cutanee quotidienne de salusine-β ou de vehicule seul pendant 12 semaines. L'expression de la salusine-b et de son ARNm a ete determinee par buvardage, immunohistochimie et d'amplification en chaine par polymerase--transcriptase inverse. Les lesions atherosclereuses ont ete analysees par coloration a l'hematoxyline et eosine (H&E) et au oil red O. Nos resultats ont montre que l'expression de la salusine-b et de son ARNm etait augmentee chez les souris [LDLR.sup.-/-]. Une injection sous-cutanee de salusine-b aggravait significativement les lesions atherosclereuses et augmentait les depots lipidiques dans les arteres des souris [LDLR.sup.-/-]. De plus, la salusine-β augmentait significativement les niveaux seriques de lipoproteine a faible densite choleterol, mais pas ceux des cholesterol total, triglycerides et lipoproteine de haute densite cholesterol. Ces resultats suggerent que l'augmentation de l'expression de la salusine-β contribue a la progression de l'atherosclerose chez les souris [LDLR.sup.-/-] en regulant a la hausse le niveau serique de lipoproteine a faible densite choleterol. Cette etude identifie une cible therapeutique potentielle pour la prevention et le traitement de l'atherosclerose. Mots-cles : atherosclerose, salusine-β, peptide, souris. [Traduit par la Redaction], Introduction Salusins constitute a new class of vasoactive peptides originally identified by Shichiri et al. in 2003, consisting of 2 related peptides of 28 and 20 amino acids, designated salusin-α [...]

Background/Aims: Ketamine is a widely used anesthetic in obstetric and pediatric anesthesia. In the developing brain, the widespread neuron apoptosis triggered by ketamine has been demonstrated. However, little is known about its effect on neural stem cells (NSCs) function. This study aimed to investigate the effect of ketamine on proliferation of NSCs from neonatal rat hippocampus. Methods: Neural stem cells were isolated from the hippocampus of Sprague-Dawley rats on postnatal day 3. In dose-response experiments, cultured neural stem cells (NSCs) were exposed to different concentrations of ketamine (0-1000 µM) for 24 hrs. The proliferative activity of NSCs was evaluated by 5-Bromo-2′-deoxyuridine (BrdU) incorporation assay. Apoptosis of neural stem cells were assessed using caspase-3 by western blot. The intracellular Ca2+ concentration ([Ca2+]i) in NSCs was analyzed by flow cytometry. The activation of protein kinase C-α (PKCα) and the phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) were measured by western blot analysis. Results: Clinical relevant concentration of ketamine (10, 20 and 50 µM) did not markedly alter the proliferation of NSCs from neonatal rat hippocampus in vitro. However, ketamine (200, 500, 800 and 1000μM) significantly inhibited the proliferation of NSCs and did not affect the expression of caspase-3. Meanwhile, ketamine (200, 500, 800 and 1000μM) also markedly decreased [Ca2+]i as well as suppressed PKCα activation and ERK1/2 phosphorylation in NSCs. A combination of subthreshold concentrations of ketamine (100 μM) and Ca2+ channel blocker verapamil (2.5 μM), PKCα inhibitor chelerythrine (2.5 μM) or ERK1/2 kinase inhibitor PD98059 (5 μM) significantly produced suprathreshold effects on PKCα activation, ERK1/2 phosphorylation and NSC proliferation. Conclusion: Ketamine inhibited proliferation of NSCs from neonatal rat hippocampus in vitro. Suppressing Ca2+-PKCα-ERK1/2 signaling pathway may be involved in this inhibitory effect of ketamine on NSCs proliferation. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

ABSTRACT Our previous and other studies have confirmed that a selective M1 and M3 receptor antagonist, Penehyclidine hydrochloride (PHC), has neuroprotection activity in cerebral ischemia. However, the precise mechanisms of protection of PHC are still elusive. In this study we analyzed PHC-mediated neuroprotection on a model of brain ischemia (oxygen and glucose deprivation), named postischemic LTP (i-LTP). We found that the activation of NMDA receptor was required for the induction of i-LTP. Compared with scopolamine, PHC could prevent it due to selectively blocking M1 receptor, not M2 receptor, to decrease NMDAR activation. Our findings further showed that the inhibition of SK2 channels occluded the prevention of PHC on NMDAR activation. Furthermore, we confirmed that PHC exerted its roles through directly disinhibition of SK2 channels by blocking M1 receptor and subsequent restricting PKC activation. Moreover, our studies further revealed the critical roles of SK2 channels in i-LTP. Thus, the mechanisms of PHC in brain protection may be involved in suppression of NMDAR by regulation of SK2 channels. Our results obtained in effects of PHC on i-LTP further provided a better understanding of the therapy strategy during stroke and identified potential therapeutic targets to prevent development of ischemia. Synapse 67:865-874, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Crocetin is a natural carotenoid compound isolated from Gardenia jasminoids Ellis. Our previous study shows that crocetin inhibits angiotensin II (Ang II)-induced vascular smooth muscle cells (VSMCs) proliferation. To further explore the mechanism by which crocetin inhibits VSMCs proliferation, in the present study we examined the effect of crocetin on cell cycle progression and cell cycle regulatory proteins. Flow cytometry analysis showed that Ang II elicited significant increase in the percentage of VSMCs in the S phase, with a concomitant decline in the percentage of VSMCs in the G0/G1 phase. However, on pretreatment of VSMCs with crocetin, the percentage of VSMCs in the S phase decreased, while that in the G0/G1 phase increased significantly. In addition, Ang II-induced increase of cell proliferation index was also decreased by crocetin. Western blotting analysis indicated that crocetin markedly inhibited the protein expression of cyclin D1 but not cyclin E. Crocetin also increased the level of cyclin-dependent kinase inhibitor (CDKI) p27kip1 but not CDKI p21waf1/cip1. In conclusion, our present results suggest that the inhibition of cell cycle G1/S transition in VSMCs by crocetin can be attributed, at least in part, to its suppression of cyclin D1 and elevation of CDKI p27kip1. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Crocetin, a carotenoid compound, was isolated from Gardenia jasminoids Ellis. Our recent study shows that crocetin inhibits angiotensin II-induced extracellular signal-regulated kinases 1/2 (ERK1/2) activation and subsequent proliferation in vascular smooth muscle cells (VSMCs). To further explore the mechanism involved, in the present study, we investigated the effect of Ca2+ in the activation of ERK1/2 and whether Ca2+ is involved in the suppression by crocetin of angiotensin II-induced ERK1/2 activation. Our findings showed that crocetin pretreatment partially attenuated both the intracellular Ca2+ mobilization and the extracellular Ca2+ influx induced by angiotensin II. Moreover, angiotensin II-induced ERK1/2 activation was completely abolished by acetoxymethyl ester of 1,2-bis(2-aminophenoxy)ethane-N,N,N ′,N′-tetraacetic acid (BAPTA-AM), an intracellular Ca2+ chelator, and partially inhibited by EGTA, an extracellular Ca2+ chelator, or verapamil, an L-type Ca2+ channel blocker. These findings suggest that Ca2+ may play an important role in angiotensin II-induced ERK1/2 activation in VSMCs, and Ca2+-dependent pathway may be involved in the inhibitory effect by crocetin of angiotensin II-induced ERK1/2 activation. [Copyright &y& Elsevier]

Objective: Neonatal exposure to propofol has been reported to cause neurotoxicity and neurocognitive decline in adulthood; however, the underlying mechanism has not been established., Methods: SD rats were exposed to propofol on postnatal day 7 (PND-7). Double-immunofluorescence staining was used to assess neurogenesis in the hippocampal dentate gyrus (DG). The expression of p-Akt and p27 were measured by western blotting. The Morris water maze, novel object recognition test, and object location test were used to evaluate neurocognitive function 2-month-old rats., Results: Phosphorylation of Akt was inhibited, while p27 expression was enhanced after neonatal exposure to propofol. Propofol also inhibited proliferation of neural stem cells (NSCs) and decreased differentiation to neurons and astroglia. Moreover, the neurocognitive function in 2-month-old rats was weakened. Of significance, intra-hippocampal injection of the Akt activator, SC79, attenuated the inhibition of p-AKT and increase of p27 expression. SC79 also rescued the propofol-induced inhibition of NSC proliferation and differentiation. The propofol-induced neurocognition deficit was also partially reversed by SC79., Conclusion: Taken together, these results suggest that neurogenesis is hindered by neonatal propofol exposure. Specifically, neonatal propofol exposure was shown to suppress the proliferation and differentiation of NSCs by inhibiting Akt/p27 signaling pathway., (Copyright © 2022 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)

Neonatal exposure to propofol induces persistent behavioral abnormalities in adulthood. In addition to triggering the apoptosis of neurons in the developing brain, anesthetics may contribute to the development of cognitive deficits by interfering neurogenesis. Given the importance of neural stem cell (NSC) proliferation in neurogenesis, the effect of propofol on NSC proliferation and the mechanisms underlying this effect were investigated. Hippocampal NSC proliferation from neonatal rats was examined using 5-bromo-2'-deoxyuridine incorporation assays in vitro. The [Ca 2+ ]i was analyzed using flow cytometry. The activations of protein kinase C (PKC)-α and extracellular signal-regulated kinases 1/2 (ERK1/2) were measured by western blot. Our results showed that propofol significantly inhibited NSC proliferation in vitro. [Ca 2+ ]i and activations of PKCα and ERK1/2 in NSCs were markedly suppressed by propofol (5, 10, 20, 40 and 80 μM). Ca 2+ channel blocker verapamil, PKCα inhibitor chelerythrine and ERK1/2 kinase inhibitor PD98059 exerted their maximal effects on NSC function at concentrations of 20, 10 and 20 μM, respectively. Propofol (20 μM) could not produce further additional suppression effects when used in combination with verapamil (20 μM), chelerythrine (10 μM) or PD98059 (20 μM). In addition, phorbol-12-myristate-13-acetate (PMA, a activator of PKC) markedly attenuated the suppressive effects of propofol on ERK1/2 phosphorylation and NSC proliferation. The inhibition effects on PKCα activation, ERK1/2 phosphorylation and NSC proliferation induced by propofol were significantly improved by BayK8644 (a calcium channel agonist). These results indicate that propofol can inhibits hippocampal NSC proliferation by suppressing the Ca 2+ -PKCα-ERK1/2 signaling pathway., (Copyright © 2019. Published by Elsevier Inc.)

Our previous and other studies have confirmed that a selective M1 and M3 receptor antagonist, Penehyclidine hydrochloride (PHC), has neuroprotection activity in cerebral ischemia. However, the precise mechanisms of protection of PHC are still elusive. In this study we analyzed PHC-mediated neuroprotection on a model of brain ischemia (oxygen and glucose deprivation), named postischemic LTP (i-LTP). We found that the activation of NMDA receptor was required for the induction of i-LTP. Compared with scopolamine, PHC could prevent it due to selectively blocking M1 receptor, not M2 receptor, to decrease NMDAR activation. Our findings further showed that the inhibition of SK2 channels occluded the prevention of PHC on NMDAR activation. Furthermore, we confirmed that PHC exerted its roles through directly disinhibition of SK2 channels by blocking M1 receptor and subsequent restricting PKC activation. Moreover, our studies further revealed the critical roles of SK2 channels in i-LTP. Thus, the mechanisms of PHC in brain protection may be involved in suppression of NMDAR by regulation of SK2 channels. Our results obtained in effects of PHC on i-LTP further provided a better understanding of the therapy strategy during stroke and identified potential therapeutic targets to prevent development of ischemia., (Copyright © 2013 Wiley Periodicals, Inc.)

Urotensin II (UII), originally identified from fish urophysis, is a potent vasoactive peptide and an endogenous ligand for an orphan G protein-coupled receptor GPR14, now named as urotensin II receptor (UT-R). In this study, we investigated the mRNA and protein expressions of UII and its receptor (UT-R) in human lung adenocarcinoma A549 cells, and the effect of exogenous UII on the proliferation of A549 cells in vitro and in vivo. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis showed that both mRNAs and proteins of UII and UT-R were obviously expressed in human lung adenocarcinoma A549 cells. Immunohistochemical analysis showed that UII peptide was mainly expressed in the cyto-plasm, and UT-R protein was expressed on the cytomembrane and also in the cytoplasm. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) analysis demonstrated that treatment with different concentrations of human UII (10(-9), 10(-8), 10(-7) and 10(-6) M) for 48 h significantly increased the number of A549 cells. The effect of UII at the concentration of 10(-7) M on the proliferation of A549 cells is most pronounced. Nude mice bearing human lung adenocarcinoma A549 cells treated with UII showed a significant increase in tumor volume and tumor weight compared with control group. These findings suggest that UII may contribute to the pathogenesis of human lung adenocarcinoma as an autocrine/paracrine growth stimulating factor.

Aim: To investigate the effect of emodin on small intestinal peristalsis of mice and to explore its relevant mechanisms., Methods: The effect of emodin on small intestinal peristalsis of mice was observed by charcoal powder propelling test of small intestine. The contents of motilin and somatostatin in small intestine of mice were determined by radioimmunoassay. The electrical potential difference (PD) related to Na+ and glucose transport was measured across the wall of reverted intestinal sacs. Na+-K+-ATPase activity of small intestinal mucosa was measured by spectroscopic analysis., Results: Different dosages of emodin can improve small intestinal peristalsis of mice. Emodin increased the content of motilin, while reduced the content of somatostatin in small intestine of mice significantly. Emodin 0.2, 0.4, 0.8, and 1.6 g/L decreased PD when there was glucose. However, emodin had little effect when glucose was free. The Na+-K+-ATPase activity of small intestinal mucosa of mice in emodin groups was inhibited obviously., Conclusion: Emodin can enhance the function of small intestinal peristalsis of mice by mechanisms of promoting secretion of motilin, lowering the content of somatostatin and inhibiting Na+-K+-ATPase activity of small intestinal mucosa.

Aim: To study the effect of montelukast on apoptosis and Fas mRNA expression of eosinophils in airway of asthmatic guinea pigs., Methods: Experimental asthma model of guinea pigs was induced by ovalbumin. The eosinophils in broncho-alveolar lavage fluid (BALF) were separated by density gradient centrifugation. The apoptosis of eosinophils was labeled by TdT-mediated dUTP nick end labeling (TUNEL) technique. Fas mRNA expression of eosinophils was detected by reverse transcription-polymerase chain reaction (RT-PCR)., Results: After treatment with montelukast, the number of eosinophils in BALF of asthmatic guinea pigs decreased significantly. The apoptosis index as well as Fas mRNA expression of eosinophils were elevated significantly. There were statistical differences between the therapeutic group and the model group., Conclusion: Apoptosis of eosinophils is highly correlated with the increased expression of Fas mRNA. Enhancing expression of Fas mRNA and promoting apoptosis of eosinophils subsequentely may be an important mechanism for montelukast to antagonize airway inflammation of asthma.

Objective: To investigate the effect of Compound Rhubarb Mixture on contraction of isolated small intestinal smooth muscle of rabbit., Methods: Serum containing Compound Rhubarb Mixture was prepared. The contraction curves of isolated small intestinal smooth muscle before and after administration of the serum were recorded by Medlab biological information collecting system., Results: The serum containing Compound Rhubarb Mixture amplified the contraction amplitude of isolated small intestinal smooth muscle of rabbit. The rate of change of contraction amplitude was elevated significantly after administration, while the frequency of contraction did not change obviously., Conclusion: The serum containing Compound Rhubarb Mixture can enhance the contractive function of isolated small intestinal smooth muscle of rabbit.