Prenatal treatment with corticosterone via maternal injection induces learning and memory impairments via delaying postsynaptic development in hippocampal CA1 neurons of rats.

Previously, we reported that prenatal exposure to high corticosterone induced attention-deficit hyperactivity disorder (ADHD)-like behaviors with cognitive deficits after weaning. In the present study, cellular mechanisms underlying cortisol-induced cognitive dysfunction were investigated using rat pups (Corti.Pups) born from rat mothers that were repetitively injected with corticosterone during pregnancy. In results, Corti.Pups exhibited the failure of behavioral memory formation in the Morris water maze (MWM) test and the incomplete long-term potentiation (LTP) of hippocampal CA1 neurons. Additionally, glutamatergic excitatory postsynaptic currents (EPSCs) were remarkably suppressed in Corti.Pups compared to normal rat pups. Incomplete LTP and weaker EPSCs in Corti.Pups were attributed to the delayed postsynaptic development of CA1 neurons, showing a higher expression of NR2B subunits and lower expression of PSD-95 and BDNF. These results indicated that the prenatal treatment with corticosterone to elevate cortisol level might potently downregulate the BDNF-mediated signaling critical for the synaptic development of hippocampal CA1 neurons during brain development, and subsequently, induce learning and memory impairment. Our findings suggest a possibility that the prenatal dysregulation of cortisol triggers the epigenetic pathogenesis of neurodevelopmental psychiatric disorders, such as ADHD and autism.

Advancing Cardiovascular Drug Screening Using Human Pluripotent Stem Cell-Derived Cardiomyocytes.

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have emerged as a promising tool for studying cardiac physiology and drug responses. However, their use is largely limited by an immature phenotype and lack of high-throughput analytical methodology. In this study, we developed a high-throughput testing platform utilizing hPSC-CMs to assess the cardiotoxicity and effectiveness of drugs. Following an optimized differentiation and maturation protocol, hPSC-CMs exhibited mature CM morphology, phenotype, and functionality, making them suitable for drug testing applications. We monitored intracellular calcium dynamics using calcium imaging techniques to measure spontaneous calcium oscillations in hPSC-CMs in the presence or absence of test compounds. For the cardiotoxicity test, hPSC-CMs were treated with various compounds, and calcium flux was measured to evaluate their effects on calcium dynamics. We found that cardiotoxic drugs withdrawn due to adverse drug reactions, including encainide, mibefradil, and cetirizine, exhibited toxicity in hPSC-CMs but not in HEK293-hERG cells. Additionally, in the effectiveness test, hPSC-CMs were exposed to ATX-II, a sodium current inducer for mimicking long QT syndrome type 3, followed by exposure to test compounds. The observed changes in calcium dynamics following drug exposure demonstrated the utility of hPSC-CMs as a versatile model system for assessing both cardiotoxicity and drug efficacy. Overall, our findings highlight the potential of hPSC-CMs in advancing drug discovery and development, which offer a physiologically relevant platform for the preclinical screening of novel therapeutics.

Pattern Analysis of Laser Fiber Degradation According to the Laser Setting: In Vitro Study of the Double-Firing Phenomenon.

BACKGROUND: It is essential to understand the mechanism of the various causes of laser fiber damage and an ideal method of reducing endoscope damage induced by laser emission in multiple sites. This study classified the different patterns of laser fiber degradation according to laser settings and analyzed the role of cavitation bubbles to find a desirable way of minimizing endoscope damage. METHODS: A total of 118 laser fibers were analyzed after 1-,3-, and 5-min laser emission to artificial stones under the settings of 1 J-10 Hz, 1 J-20 Hz, 1 J-30 Hz, and 2 J-10 Hz. Every 3 cm from the fiber tip was marked and examined with a digital microscope and a high-speed camera. The images of the fibers and the movement of cavitation bubbles were taken with a distance of 1 to 5 mm from the gel. RESULTS: Seven types of fiber damage (charring, limited and extensive peeled-off, bumpy, whitish plaque, crack, and break-off) coincided during laser emission. Damages rapidly increased with emission time > 3 minutes regardless of the laser settings. The damaged lengths covered 5 mm on average, and the fibers at 5-min emission were significantly shorter than others. The fiber durability of 1J-10Hz setting was better than other settings after 3-min laser emission. Backward movement of the cavitation bubbles was found at the 1-mm distance from the gel, and the damaged lengths were longer than the diameters of the cavitation bubbles because of their proximal movement. CONCLUSION: The damage patterns of the laser fiber tips were classified into seven types. The heat damage around the surface of the laser fiber can be increased according to the high-energy or high-frequency laser setting, a short distance to the stone, a short distance from the tips of flexible ureteroscopes, no cutting laser fiber procedures, and the inappropriate use of irrigation fluid or laser fiber jacket.

Simultaneous measurements of acoustic emission and sonochemical luminescence for monitoring ultrasonic cavitation.

In the present study, a novel hybrid method was considered to identify and measure inertial cavitation activity using acoustic and optical emissions from violent bubble collapses. A photomultiplier (PMT) tube and a calibrated cylindrical needle hydrophone were used to simultaneously detect sonochemical luminescence (SCL) signals and acoustic emissions, respectively, during sonication. A cylindrical focusing ultrasound transducer operating at 398.4 kHz was employed to produce a dense cavitation bubble cloud at the focus. The results clearly showed that a similar trend between the PMT output (i.e., the SCL results) and the broad band acoustic emissions started to appear at the frequencies considered above the fourth harmonic of the sonication frequency. The experimental observation suggests that the occurrence of inertial cavitation can be monitored using the high pass spectral acoustic power and the cut-off frequency can be effectively chosen with the aid of sonochemical luminescence measurement. The hybrid method is expected to be useful for cavitation dosimetry in various medical and industrial applications.

Diethylstilbestrol, a Novel ANO1 Inhibitor, Exerts an Anticancer Effect on Non-Small Cell Lung Cancer via Inhibition of ANO1.

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer-related mortality; thus, therapeutic targets continue to be developed. Anoctamin1 (ANO1), a novel drug target considered for the treatment of NSCLC, is a Ca2+-activated chloride channel (CaCC) overexpressed in various carcinomas. It plays an important role in the development of cancer; however, the role of ANO1 in NSCLC is unclear. In this study, diethylstilbestrol (DES) was identified as a selective ANO1 inhibitor using high-throughput screening. We found that DES inhibited yellow fluorescent protein (YFP) fluorescence reduction caused by ANO1 activation but did not inhibit cystic fibrosis transmembrane conductance regulator channel activity or P2Y activation-related cytosolic Ca2+ levels. Additionally, electrophysiological analyses showed that DES significantly reduced ANO1 channel activity, but it more potently reduced ANO1 protein levels. DES also inhibited the viability and migration of PC9 cells via the reduction in ANO1, phospho-ERK1/2, and phospho-EGFR levels. Moreover, DES induced apoptosis by increasing caspase-3 activity and PARP-1 cleavage in PC9 cells, but it did not affect the viability of hepatocytes. These results suggest that ANO1 is a crucial target in the treatment of NSCLC, and DES may be developed as a potential anti-NSCLC therapeutic agent.

Calcium Channels as Novel Therapeutic Targets for Ovarian Cancer Stem Cells.

Drug resistance in epithelial ovarian cancer (EOC) is reportedly attributed to the existence of cancer stem cells (CSC), because in most cancers, CSCs still remain after chemotherapy. To overcome this limitation, novel therapeutic strategies are required to prevent cancer recurrence and chemotherapy-resistant cancers by targeting cancer stem cells (CSCs). We screened an FDA-approved compound library and found four voltage-gated calcium channel blockers (manidipine, lacidipine, benidipine, and lomerizine) that target ovarian CSCs. Four calcium channel blockers (CCBs) decreased sphere formation, viability, and proliferation, and induced apoptosis in ovarian CSCs. CCBs destroyed stemness and inhibited the AKT and ERK signaling pathway in ovarian CSCs. Among calcium channel subunit genes, three L- and T-type calcium channel genes were overexpressed in ovarian CSCs, and downregulation of calcium channel genes reduced the stem-cell-like properties of ovarian CSCs. Expressions of these three genes are negatively correlated with the survival rate of patient groups. In combination therapy with cisplatin, synergistic effect was shown in inhibiting the viability and proliferation of ovarian CSCs. Moreover, combinatorial usage of manidipine and paclitaxel showed enhanced effect in ovarian CSCs xenograft mouse models. Our results suggested that four CCBs may be potential therapeutic drugs for preventing ovarian cancer recurrence.

Neuroligin-1 controls synaptic abundance of NMDA-type glutamate receptors through extracellular coupling.

Despite the pivotal functions of the NMDA receptor (NMDAR) for neural circuit development and synaptic plasticity, the molecular mechanisms underlying the dynamics of NMDAR trafficking are poorly understood. The cell adhesion molecule neuroligin-1 (NL1) modifies NMDAR-dependent synaptic transmission and synaptic plasticity, but it is unclear whether NL1 controls synaptic accumulation or function of the receptors. Here, we provide evidence that NL1 regulates the abundance of NMDARs at postsynaptic sites. This function relies on extracellular, NL1 isoform-specific sequences that facilitate biochemical interactions between NL1 and the NMDAR GluN1 subunit. Our work uncovers NL1 isoform-specific cis-interactions with ionotropic glutamate receptors as a key mechanism for controlling synaptic properties.

Discovery of a novel natural compound, vitekwangin B, with ANO1 protein reduction properties and anticancer potential.

Background: Prostate cancer and non-small cell lung cancer (NSCLC) present significant challenges in the development of effective therapeutic strategies. Hormone therapies for prostate cancer target androgen receptors and prostate-specific antigen markers. However, treatment options for prostatic small-cell neuroendocrine carcinoma are limited. NSCLC, on the other hand, is primarily treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors but exhibits resistance. This study explored a novel therapeutic approach by investigating the potential anticancer properties of vitekwangin B, a natural compound derived from Vitex trifolia. Methods: Vitekwangin B was chromatographically isolated from the fruits of V. trifolia. ANO1 protein levels in prostate cancer and NSCLC cells were verified and evaluated again after vitekwangin B treatment. Results: Vitekwangin B did not inhibit anoctamin1 (ANO1) channel function but significantly reduced ANO1 protein levels. These results demonstrate that vitekwangin B effectively inhibited cancer cell viability and induced apoptosis in prostate cancer and NSCLC cells. Moreover, it exhibited minimal toxicity to liver cells and did not affect hERG channel activity, making it a promising candidate for further development as an anticancer drug. Conclusion: Vitekwangin B may offer a new direction for cancer therapy by targeting ANO1 protein, potentially improving treatment outcomes in patients with prostate cancer and NSCLC. Further research is needed to explore its full potential and overcome existing drug resistance challenges.

Effectiveness of lumbar motion style acupuncture treatment on inpatients with acute low back pain: A pragmatic, randomized controlled trial.

BACKGROUND AND PURPOSE: This parallel, single-center, pragmatic, randomized controlled study aimed to investigate the effectiveness and safety of motion style acupuncture treatment (MSAT; a combination of acupuncture and Doin therapy) to reduce pain and improve the functional disability of patients with acute low back pain (aLBP) due to road traffic accidents. MATERIALS AND METHODS: Ninety-six patients with aLBP admitted to the Haeundae Jaseng Hospital of Korean Medicine in South Korea due to traffic accidents were treated with integrative Korean medicine (IKM) with additional 3-day MSAT sessions during hospitalization (MSAT group, 48 patients) or without (control group, 48 patients), and followed up for 90 days. RESULTS: The mean numeric rating scale (NRS) scores of low back pain (LBP) of the MSAT and control groups were both 6.7 (95% confidence interval [CI]: 6.3, 7.1) at baseline. After completing the third round of all applicable treatment sessions (the primary endpoint in this study), the mean NRS scores of the MSAT and control groups were 3.76 (95% CI: 3.54, 3.99) and 5.32 (95% CI: 5.09, 5.55), respectively. The difference in the mean NRS score between the two groups was 1.56 (95% CI: 1.25, 1.87). CONCLUSION: IKM treatment combined with MSAT can reduce pain and improve the range of motion of patients with aLBP. TRIAL REGISTRATION: This trial is registered at ClinicalTrial.gov (NCT04956458).

The importance of the NRG-1/ErbB4 pathway for synaptic plasticity and behaviors associated with psychiatric disorders.

Neuregulin 1 (NRG-1) and its receptor ErbB4 have emerged as biologically plausible schizophrenia risk factors, modulators of GABAergic and dopaminergic neurotransmission, and as potent regulators of glutamatergic synaptic plasticity. NRG-1 acutely depotentiates LTP in hippocampal slices, and blocking ErbB kinase activity inhibits LTP reversal by theta-pulse stimuli (TPS), an activity-dependent reversal paradigm. NRG-1/ErbB4 signaling in parvalbumin (PV) interneurons has been implicated in inhibitory transmission onto pyramidal neurons. However, the role of ErbB4, in particular in PV interneurons, for LTP reversal has not been investigated. Here we show that ErbB4-null (ErbB4(-/-)) and PV interneuron-restricted mutant (PV-Cre;ErbB4) mice, as well as NRG-1 hypomorphic mice, exhibit increased hippocampal LTP. Moreover, both ErbB4(-/-) and PV-Cre;ErbB4 mice lack TPS-mediated LTP reversal. A comparative behavioral analysis of full and conditional ErbB4 mutant mice revealed that both exhibit hyperactivity in a novel environment and deficits in prepulse inhibition of the startle response. Strikingly, however, only ErbB4(-/-) mice exhibit reduced anxiety-like behaviors in the elevated plus maze task and deficits in cued and contextual fear conditioning. These results suggest that aberrant NRG-1/ErbB4 signaling in PV interneurons accounts for some but not all behavioral abnormalities observed in ErbB4(-/-) mice. Consistent with the observation that PV-Cre;ErbB4 mice exhibit normal fear conditioning, we find that ErbB4 is broadly expressed in the amygdala, largely by cells negative for PV. These findings are important to better understand ErbB4's role in complex behaviors and warrant further analysis of ErbB4 mutant mice lacking the receptor in distinct neuron types.

An activity-regulated microRNA, miR-188, controls dendritic plasticity and synaptic transmission by downregulating neuropilin-2.

MicroRNAs (miRNAs) have recently come to be viewed as critical players that modulate a number of cellular features in various biological systems including the mature CNS by exerting regulatory control over the stability and translation of mRNAs. Despite considerable evidence for the regulatory functions of miRNAs, the identities of the miRNA species that are involved in the regulation of synaptic transmission and plasticity and the mechanisms by which these miRNAs exert functional roles remain largely unknown. In the present study, the expression of microRNA-188 (miR-188) was found to be upregulated by the induction of long-term potentiation (LTP). The protein level of neuropilin-2 (Nrp-2), one of the possible molecular targets for miR-188, was decreased during LTP induction. We also confirmed that the luciferase activity of the 3'-UTR of Nrp-2 was diminished by treatment with a miR-188 oligonucleotide but not with a scrambled miRNA oligonucleotide. Nrp-2 serves as a receptor for semaphorin 3F, which is a negative regulator of spine development and synaptic structure. In addition, miR-188 specifically rescued the reduction in dendritic spine density induced by Nrp-2 expression in hippocampal neurons from rat primary culture. Furthermore, miR-188 counteracted the decrease in the miniature EPSC frequency induced by Nrp-2 expression in hippocampal neurons from rat primary culture. These findings suggest that miR-188 serves to fine-tune synaptic plasticity by regulating Nrp-2 expression.

Macrophages promote Fibrinogenesis during kidney injury.

Macrophages (Mø) are widely considered fundamental in the development of kidney fibrosis since Mø accumulation commonly aggravates kidney fibrosis, while Mø depletion mitigates it. Although many studies have aimed to elucidate Mø-dependent mechanisms linked to kidney fibrosis and have suggested various mechanisms, the proposed roles have been mostly passive, indirect, and non-unique to Mø. Therefore, the molecular mechanism of how Mø directly promote kidney fibrosis is not fully understood. Recent evidence suggests that Mø produce coagulation factors under diverse pathologic conditions. Notably, coagulation factors mediate fibrinogenesis and contribute to fibrosis. Thus, we hypothesized that kidney Mø express coagulation factors that contribute to the provisional matrix formation during acute kidney injury (AKI). To test our hypothesis, we probed for Mø-derived coagulation factors after kidney injury and uncovered that both infiltrating and kidney-resident Mø produce non-redundant coagulation factors in AKI and chronic kidney disease (CKD). We also identified F13a1, which catalyzes the final step of the coagulation cascade, as the most strongly upregulated coagulation factor in murine and human kidney Mø during AKI and CKD. Our in vitro experiments revealed that the upregulation of coagulation factors in Mø occurs in a Ca2 + -dependent manner. Taken together, our study demonstrates that kidney Mø populations express key coagulation factors following local injury, suggesting a novel effector mechanism of Mø contributing to kidney fibrosis.

Dopaminergic cell protection and alleviation of neuropsychiatric disease symptoms by VMAT2 expression through the class I HDAC inhibitor TC-H 106.

The importance of vesicular monoamine transporter 2 (VMAT2) in dopamine regulation, which is considered crucial for neuropsychiatric disorders, is currently being studied. Moreover, the development of disease treatments using histone deacetylase (HDAC) inhibitors (HDACi) is actively progressing in various fields. Recently, research on the possibility of regulating neuropsychiatric disorders has been conducted. In this study, we evaluated whether VMAT2 expression increased by an HDACi can fine-tune neuropsychotic behavior, such as attention deficit hyperactivity disorder (ADHD) and protect against the cell toxicity through oxidized dopamine. First, approximately 300 candidate HDACi compounds were added to the SH-SY5Y dopaminergic cell line to identify the possible changes in the VMAT2 expression levels, which were measured using quantitative polymerase chain reaction. The results demonstrated, that treatment with pimelic diphenylamide 106 (TC-H 106), a class I HDACi, increased VMAT2 expression in both the SH-SY5Y cells and mouse brain. The increased VMAT2 expression induced by TC-H 106 alleviated the cytotoxicity attributed to 6-hydroxydopamine (6-OHDA) or 1-methyl-4-phenylpyridinium (MPP+ ) and free dopamine treatment. Moreover, dopamine concentrations, both intracellularly and in the synaptosomes, were significantly elevated by increased VMAT2 expression. These results suggest that dopamine concentration regulation by VMAT2 expression induced by TC-H 106 could alter several related behavioral aspects that was confirmed by attenuation of hyperactivity and impulsivity, which were major characteristics of animal model showing ADHD-like behaviors. These results indicate that HDACi-increased VMAT2 expression offers sufficient protections against dopaminergic cell death induced by oxidative stress. Thus, the epigenetic approach could be considered as therapeutic candidate for neuropsychiatric disease regulation.

ANO1-downregulation induced by schisandrathera D: a novel therapeutic target for the treatment of prostate and oral cancers.

Anoctamin 1 (ANO1), a drug target for various cancers, including prostate and oral cancers, is an intracellular calcium-activated chloride ion channel that plays various physiopathological roles, especially in the induction of cancer growth and metastasis. In this study, we tested a novel compound isolated from Schisandra sphenanthera, known as schisandrathera D, for its inhibitory effect on ANO1. Schisandrathera D dose-dependently suppressed the ANO1 activation-mediated decrease in fluorescence of yellow fluorescent protein; however, it did not affect the adenosine triphosphate-induced increase in the intracellular calcium concentration or forskolin-induced cystic fibrosis transmembrane conductance regulator activity. Specifically, schisandrathera D gradually decreased the levels of ANO1 protein and significantly reduced the cell viability in ANO1-expressing cells when compared to those in ANO1-knockout cells. These effects could be attributed to the fact that schisandrathera D displayed better binding capacity to ANO1 protein than the previously known ANO1 inhibitor, Ani9. Finally, schisandrathera D increased the levels of caspase-3 and cleaved poly (ADP-ribose) polymerase 1, thereby indicating that its anticancer effect is mediated through apoptosis. Thus, this study highlights that schisandrathera D, which reduces ANO1 protein levels, has apoptosis-mediated anticancer effects in prostate and oral cancers, and thus, can be further developed into an anticancer agent.

Understanding cavitation-related mechanism of therapeutic ultrasound in the field of urology: Part I of therapeutic ultrasound in urology.

Shock waves are commonly used in the field of urology. They have two phases, positive and negative, and the bubble generation is roughly classified into acoustic cavitation (AC) and laser-induced cavitation (LIC). We evaluated the occurrence of cavitation, its duration, the area of interest, and the maximal diameter of the cavitation bubbles. Changes in AC occurred at 0.2 ms with the highest number of bubbles and disappeared at 0.6 ms. The bubble size was 2 mm in diameter. Changes in LIC bubbles were observed in three pulse modes. The short pulse showed an initial bubble starting at 0.005 ms, which reached its largest size at 0.4 to 0.6 ms. The long pulse showed an initial bubble starting at 0.005 ms, which reached its largest size at 0.4 ms with the formation of an additional lagena-shaped bubble at 0.6 ms. The distance mode of MOSES showed two signal peaks with the formation of two consecutive bubbles at 0.2 and 0.6 ms. The main difference in the laser beams between the long-pulse and the MOSES modes was the continuity and the peak power of the laser beam. The diameters parallel to the laser direction were 6.8, 8.6, and 9.7 mm at 1, 2, and 3 J, respectively, in the short pulse. While the cavitation bubbles rupture, ejectile force occurs in numerous directions, transmitting high enough energy to break the targets. Cavitation bubbles should be regarded as energy and the mediators of energy for stone fragmentation and tissue destruction.

Anticancer effect of verteporfin on non-small cell lung cancer via downregulation of ANO1.

Anoctamin 1 (ANO1) is a calcium-activated chloride channel found in various cell types and is overexpressed in non-small cell lung cancer (NSCLC), a major cause of cancer-related mortality. With the rising interest in development of druggable compounds for NSCLC, there has been a corresponding rise in interest in ANO1, a novel drug target for NSCLC. However, as ANO1 inhibitors that have been discovered simultaneously exhibit both the functions of an inhibition of ANO1 channel as well as a reduction of ANO1 protein levels, it is unclear which of the two functions directly causes the anticancer effect. In this study, verteporfin, a chemical compound that reduces ANO1 protein levels was identified through high-throughput screening. Verteporfin did not inhibit ANO1-induced chloride secretion but reduced ANO1 protein levels in a dose-dependent manner with an IC50 value of ~300 nM. Moreover, verteporfin inhibited neither P2Y receptor-induced intracellular Ca2+ mobilization nor cystic fibrosis transmembrane conductance regulator (CFTR) channel activity, and molecular docking studies revealed that verteporfin bound to specific sites of ANO1 protein. Confirming that verteporfin reduces ANO1 protein levels, we then investigated the molecular mechanisms involved in its effect on NSCLC cells. Interestingly, verteporfin decreased ANO1 protein levels, the EGFR-STAT3 pathway as well as ANO1 mRNA expression. Verteporfin reduced the viability of ANO1-expressing cells (PC9, and gefitinib-resistant PC9) and induced apoptosis by increasing caspase-3 activity and PARP-1 cleavage. However, it did not affect hERG channel activity. These results show that the anticancer mechanism of verteporfin is caused via the down-regulation of ANO1.

Temporal and spectral characteristics of the impulsive waves produced by a clinical ballistic shock wave therapy device.

This study characterizes the temporal and spectral property of the mechanical impulsive waves produced by a clinical ballistic shock wave therapy device. The impulsive waves were generated by a projectile impacting a metallic shock wave transmitter, and were measured using a laser vibrometer that detects vibrations on the front surface of the shock wave transmitter. The shock wave transmitter considered in the measurement has a circular flat surface tip with a diameter of 15 mm. The results showed that the measured impulsive wave was resonated at 93.4 kHz and modulated with a relatively low frequency of 3.7 kHz to form a heavily damped pulse wave lasting for longer than 2 ms. Multiple impulsive waves produced at high output settings, were observed for the first time, and their clinical implication needs to be elucidated in the future study. Despite measurements made on the cavitation free air born impulsive waves, the study was justified by the experimental clarification that their temporal and spectral properties were characteristically similar to those of the impulsive waves produced in water, more representative to clinical conditions. The present results are expected to deliver critical information for assessing the shock wave dose delivered from a clinical radial extracorporeal shock wave device to patients.

Repositioning Trimebutine Maleate as a Cancer Treatment Targeting Ovarian Cancer Stem Cells.

The overall five-year survival rate for late-stage patients of ovarian cancer is below 29% due to disease recurrence and drug resistance. Cancer stem cells (CSCs) are known as a major contributor to drug resistance and recurrence. Accordingly, therapies targeting ovarian CSCs are needed to overcome the limitations of present treatments. This study evaluated the effect of trimebutine maleate (TM) targeting ovarian CSCs, using A2780-SP cells acquired by a sphere culture of A2780 epithelial ovarian cancer cells. TM is indicated as a gastrointestinal motility modulator and is known to as a peripheral opioid receptor agonist and a blocker for various channels. The GI50 of TM was approximately 0.4 µM in A2780-SP cells but over 100 µM in A2780 cells, demonstrating CSCs specific growth inhibition. TM induced G0/G1 arrest and increased the AV+/PI+ dead cell population in the A2780-SP samples. Furthermore, TM treatment significantly reduced tumor growth in A2780-SP xenograft mice. Voltage gated calcium channels (VGCC) and calcium-activated potassium channels (BKCa) were overexpressed on ovarian CSCs and targeted by TM; inhibition of both channels reduced A2780-SP cells viability. TM reduced stemness-related protein expression; this tendency was reproduced by the simultaneous inhibition of VGCC and BKCa compared to single channel inhibition. In addition, TM suppressed the Wnt/ß-catenin, Notch, and Hedgehog pathways which contribute to many CSCs characteristics. Specifically, further suppression of the Wnt/ß-catenin pathway by simultaneous inhibition of BKCa and VGCC is necessary for the effective and selective action of TM. Taken together, TM is a potential therapeutic drug for preventing ovarian cancer recurrence and drug resistance.

Neuregulins and neuronal plasticity: possible relevance in schizophrenia.

Polymorphisms in the Neuregulin 1 (NRG1) and ErbB4 receptor genes have been associated with schizophrenia in numerous cohort and family studies, and biochemical measurements from postmortem prefrontal cortex homogenates suggest that NRG/ErbB signalling is altered in schizophrenia. Moreover, recent work from our group, and from others, indicates that NRG/ErbB signalling has a role in regulating glutamatergic transmission--an intriguing finding given that glutamatergic hypofunction has been proposed to be involved in the pathogenesis underlying schizophrenia. Here we will provide a brief background of the complexity of the NRG/ErbB signalling system. We will then focus on how NRG1 reverses (depotentiates) long-term potentiation (LTP) at hippocampal Schaeffer collateral--CA1 glutamatergic synapses in the adult brain. Specifically, we found that NRG1 depotentiates LTP in an activity- and time-dependent manner. A role of endogenous NRG for regulating plasticity at hippocampal synapses is supported by experiments demonstrating that ErbB receptor antagonists completely block LTP depotentiation by brief theta-pulse stimuli, a subthreshold stimulus paradigm that reverses LTP in live animals. Preliminary results indicate that NRG1-mediated LTP depotentiation is NMDA receptor independent, and manifests as an internalization of GluR1-containing AMPA receptors. The importance of the NRG/ ErbB signalling pathway in regulating homeostasis at glutamatergic synapses, and its possible implications for schizophrenia, will be discussed.

Neuregulin-1 reverses long-term potentiation at CA1 hippocampal synapses.

Neuregulin-1 (NRG-1) has been identified genetically as a schizophrenia susceptibility gene, but its function in the adult brain is unknown. Here, we show that NRG-1beta does not affect basal synaptic transmission but reverses long-term potentiation (LTP) at hippocampal Schaffer collateral-->CA1 synapses in an activity- and time-dependent manner. Depotentiation by NRG-1beta is blocked by two structurally distinct and selective ErbB receptor tyrosine kinase inhibitors. Moreover, ErbB receptor inhibition increases LTP at potentiated synapses and blocks LTP reversal by theta-pulse stimuli. NRG-1beta selectively reduces AMPA, not NMDA, receptor EPSCs and has no effect on paired-pulse facilitation ratios. Live imaging of hippocampal neurons transfected with receptors fused to superecliptic green fluorescent protein, as well as quantitative analysis of native receptors, show that NRG-1beta stimulates the internalization of surface glutamate receptor 1-containing AMPA receptors. This novel regulation of LTP by NRG-1 has important implications for the modulation of synaptic homeostasis and schizophrenia.