Design Strategies of 40 nm Split-Gate NOR Flash Memory Device for Low-Power Compute-in-Memory Applications.

The existing von Neumann architecture for artificial intelligence (AI) computations suffers from excessive power consumption and memory bottlenecks. As an alternative, compute-in-memory (CIM) technology has been emerging. Among various CIM device candidates, split-gate NOR flash offers advantages such as a high density and low on-state current, enabling low-power operation, and benefiting from a high level of technological maturity. To achieve high energy efficiency and high accuracy in CIM inference chips, it is necessary to optimize device design by targeting low power consumption at the device level and surpassing baseline accuracy at the system level. In split-gate NOR flash, significant factors that can cause CIM inference accuracy drop are the device conductance variation, caused by floating gate charge variation, and a low on-off current ratio. Conductance variation generally has a trade-off relationship with the on-current, which greatly affects CIM dynamic power consumption. In this paper, we propose strategies for designing optimal devices by adjusting oxide thickness and other structural parameters. As a result of setting Tox,FG to 13.4 nm, TIPO to 4.6 nm and setting other parameters to optimal points, the design achieves erase on-current below 2 µA, program on-current below 10 pA, and off-current below 1 pA, while maintaining an inference accuracy of over 92%.

Is fasting beneficial for hospitalized patients with inflammatory bowel diseases?

BACKGROUND/AIMS: Patients with inflammatory bowel disease (IBD) are usually hospitalized because of aggravated gastrointestinal symptoms. Many clinicians empirically advise these patients to fast once they are admitted. However, there has been no evidence that maintaining a complete bowel rest improves the disease course. Therefore, we aimed to investigate the effects of fasting on disease course in admitted patients with IBD or intestinal Behçet's disease. METHODS: A total of 222 patients with IBD or intestinal Behçet's disease, who were admitted for disease-related symptoms, were retrospectively analyzed. We divided them into 2 groups: fasting group (allowed to take sips of water but no food at the time of admission) and dietary group (received liquid, soft, or general diet). RESULTS: On admission, 124 patients (55.9%) started fasting and 98 patients (44.1%) started diet immediately. Among patients hospitalized through the emergency room, a significantly higher proportion underwent fasting (63.7% vs. 21.4%, P<0.001); however, 96.0% of the patients experienced dietary changes. Corticosteroid use (P<0.001; hazard ratio, 2.445; 95% confidence interval, 1.506-3.969) was significantly associated with a reduction in the disease activity score, although there was no significant difference between the fasting group and the dietary group in disease activity reduction (P=0.111) on multivariate analysis. CONCLUSIONS: In terms of disease activity reduction, there was no significant difference between the fasting and dietary groups in admitted patients with IBD, suggesting that imprudent fasting is not helpful in improving the disease course. Therefore, peroral diet should not be avoided unless not tolerated by the patient.

Radix Sophorae Flavescentis inhibits proliferation and induces apoptosis of AGS human gastric cancer cells.

Traditional herbal medicines are being increasingly used worldwide to treat cancer. Radix Sophorae Flavescentis (RSF) is a Chinese herb, which has numerous pharmacological properties, including anti­tumour effects. In this study, we investigated the mechanisms underlying RSF­induced apoptosis in human gastric cancer cells (AGS cells). We found that RSF treatment (20­200 µg/ml) inhibited the proliferation of AGS cells and increased the sub­G1 phase ratio. RSF­induced cell death was associated with the downregulation of BCl­2 and upregulation of Bax. In addition to increasing the expression levels of apoptosis­mediating surface antigen FAS and Fas ligand, RSF also activated caspase­3; however, mitogen­activated protein kinase appeared to inhibit RSF­induced cell death. RSF also led to an increased production of reactive oxygen species. Based on these results, we propose that RSF could be a potential therapeutic agent for gastric cancer.

A Novel Monoclonal Antibody Targets Mucin1 and Attenuates Growth in Pancreatic Cancer Model.

Mucin1 (MUC1) is a highly glycosylated transmembrane protein that plays a crucial role in the lubrication and protection of normal epithelial cells. However, MUC1 has emerged as a potential target for cancer therapy because it is overexpressed and functions in several types of cancers. Recently, we produced a monoclonal antibody (the anti-hMUC1 antibody) specific to the extracellular region of the MUC1 subunit MUC1-C to evaluate the utility of using anti-MUC1 antibodies in pancreatic cancer models. The anti-hMUC1 antibody recognized the MUC1-C protein in pancreatic cancer cells. Based on immunostaining and confocal image analyses, the anti-hMUC1 antibody initially bound to the cell membrane then was internalized in cancer cells that express MUC1. The anti-hMUC1 antibody suppressed epidermal growth factor (EGF)-mediated extracellular signal⁻regulated kinase (ERK) phosphorylation and cyclin D1 expression. When the anti-hMUC1 antibody was injected into a xenograft mouse model and traced using an in vivo imaging system, we observed that the anti-hMUC1 antibody was localized to MUC1-expressing pancreatic tumors. Importantly, the anti-hMUC1 monoclonal antibody suppressed pancreatic tumor growth in mice. According to immunohistochemistry analysis using a pancreatic cancer tissue array and the anti-hMUC1 antibody, MUC1 was highly expressed in human pancreatic cancer tissues compared to normal tissues. Therefore, we conclude that the anti-hMUC1 antibody specifically targets MUC1 and suppresses its function in pancreatic cancer in vitro and in vivo and can be further developed as a promising targeted therapy to treat pancreatic cancer.

The Mechanism of Action of Zingerone in the Pacemaker Potentials of Interstitial Cells of Cajal Isolated from Murine Small Intestine.

BACKGROUND/AIMS: Zingerone, a major component found in ginger root, is clinically effective for the treatment of various diseases. Interstitial cells of Cajal (ICCs) are the pacemaker cells responsible for slow waves in the gastrointestinal (GI) tract. We investigated the effects of zingerone on the pacemaker potentials of ICCs to assess its mechanisms of action and its potential as a treatment for GI tract motility disorder. METHODS: We isolated ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record the pacemaker potentials in cultured ICCs. RESULTS: Under the current clamping mode, zingerone inhibited pacemaker potentials of ICCs concentration-dependently. These effects were blocked not by capsazepine, a transient receptor potential vanilloid 1 (TRPV1) channel blocker, but by glibenclamide, a specific ATP-sensitive K+ channel blocker. Pretreatment with SQ-22536 (an adenylate cyclase inhibitor), LY294002 (a phosphoinositide 3-kinase inhibitor), and calphostin C (a protein kinase C (PKC) inhibitor) did not block the effects of zingerone on the pacemaker potentials relative to treatment with zingerone alone. However, zingerone-induced pacemaker potential inhibition was blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ; a guanylate cyclase inhibitor), KT5823 (a protein kinase G (PKG) inhibitor), and L-NAME (a non-selective nitric oxide synthase (NOS) inhibitor). In addition, zingerone stimulated cyclic guanosine monophosphate (cGMP) production in ICCs. Finally, pretreatment with PD98059 (a p42/44 mitogen-activated protein kinase (MAPK) inhibitor), SB203580 (a p38 MAPK inhibitor), and SP600125 (c-Jun N-terminal kinases (JNK)-specific inhibitor) blocked the zingerone-induced pacemaker potential inhibition. CONCLUSION: These results suggest that zingerone concentration-dependently inhibits pacemaker potentials of ICCs via NO/cGMP-dependent ATP-sensitive K+ channels through MAPK-dependent pathways. Taken together, this study shows that zingerone may have the potential for development as a GI regulation agent.

Modulation of Pacemaker Potentials in Murine Small Intestinal Interstitial Cells of Cajal by Gamisoyo-San, a Traditional Chinese Herbal Medicine.

BACKGROUND: The Gamisoyo-san (GSS) has been used for -improving the gastrointestinal (GI) symptoms. The purpose of this study was to investigate the effects of GSS, a traditional Chinese herbal medicine, on the pacemaker potentials of mouse small intestinal interstitial cells of Cajal (ICCs). METHODS: ICCs from the small intestines were dissociated and cultured. Whole-cell patch-clamp configuration was used to record pacemaker potentials and membrane currents. RESULTS: GSS depolarized ICC pacemaker potentials in a dose-dependent manner. Pretreatment with 4-diphenylacetoxypiperidinium iodide completely inhibited GSS-induced pacemaker potential depolarizations. Intracellular GDP-ß-S inhibited GSS-induced effects, and in the presence of U-73122, GSS-induced effects were inhibited. Also, GSS in the presence of a Ca2+-free solution or thapsigargin did not depolarize pacemaker potentials. However, in the presence of calphostin C, GSS slightly depolarized pacemaker potentials. Furthermore, GSS inhibited both transient receptor potential melastatin7 and Ca2+-activated Cl- channel (anoctamin1) currents. CONCLUSION: GSS depolarized pacemaker potentials of ICCs via G protein and muscarinic M3 receptor signaling pathways and through internal or external Ca2+-, phospholipase C-, and protein kinase C-dependent and transient receptor potential melastatin 7-, and anoctamin 1-independent pathways. The study shows that GSS may regulate GI tract motility, suggesting that GSS could be a basis for developing novel prokinetic agents for treating GI motility dysfunctions.

A Mucin1 C-terminal Subunit-directed Monoclonal Antibody Targets Overexpressed Mucin1 in Breast Cancer.

Background: Mucin1 (MUC1) is a highly glycosylated transmembrane protein that has gained attention because of its overexpression in various cancers. However, MUC1-targeted therapeutic antibodies have not yet been approved for cancer therapy. MUC1 is cleaved to two subunits, MUC1-N and MCU1-C. MUC1-N is released from the cell surface, making MUC1-C a more reasonable target for cancer therapy. Therefore, we produced a monoclonal antibody (anti-hMUC1) specific to the extracellular region of MUC1-C and evaluated its effects in vitro and in vivo. Methods: We produced a monoclonal antibody (anti-hMUC1) using a purified recombinant human MUC1 polypeptide and our novel immunization protocol. The reactivity of anti-hMUC1 was characterized by ELISA, western blotting and immunoprecipitation analyses. The localization of the antibody in the breast cancer cells after binding was determined by confocal image analysis. The effects of the antibody on the growth of cells were also investigated. We injected anti-hMUC1 and performed in vivo tracing analysis in xenograft mouse models. In addition, expression of MUC1 in tissue sections from patients with breast cancer was assessed by immunohistochemistry with anti-hMUC1. Results: The anti-hMUC1 antibody recognized recombinant MUC1 as well as native MUC1-C protein in breast cancer cells. Anti-hMUC1 binds to the membrane surface of cells that express MUC1 and is internalized in some cancer cell lines. Treatment with anti-hMUC1 significantly reduced proliferation of cells in which anti-hMUC1 antibody is internalized. Furthermore, the anti-hMUC1 antibody was specifically localized in the MUC1-expressing breast cancer cell-derived tumors in xenograft mouse models. Based on immunohistochemistry analysis, we detected significantly higher expression of MUC1 in cancer tissues than in normal control tissues. Conclusion: Our results reveal that the anti-hMUC1 antibody targets the extracellular region of MUC1-C subunit and may have utility in future applications as an anti-breast cancer agent.

Anti-metastatic effect of the TM4SF5-specific peptide vaccine and humanized monoclonal antibody on colon cancer in a mouse lung metastasis model.

Transmembrane 4 superfamily member 5 protein (TM4SF5) is a potential therapeutic target for hepatocellular carcinoma (HCC) and colon cancer. In a previous study, we demonstrated the prophylactic and therapeutic effects of a TM4SF5-specific peptide vaccine and monoclonal antibody in HCC and colon cancer in a mouse model. Here, we designed a cyclic peptide targeting TM4SF5. Cyclic peptide-specific antibodies were produced in mice after immunization with a complex of the peptide, CpG-DNA, and liposomes. Intravenous injection of the CT-26 mouse colon cancer cell line into mice induced tumors in the lung. Immunization with the peptide vaccine improved the survival rate and reduced the growth of lung tumors. We established a monoclonal antibody specific to the cyclic TM4SF5-based peptide and humanized the antibody sequence by complementarity determining region-grafting. The humanized antibody was reactive to the cyclic peptide and TM4SF5 protein. Treatment of CT-26 cells with the humanized antibody reduced cell motility in vitro. Furthermore, direct injection of the humanized anti-TM4SF5 antibody in vivo reduced growth of lung tumors in mouse metastasis model. Therefore, we conclude that the immunization with the cyclic peptide vaccine and injection of the TM4SF5-specifc humanized antibody have an anti-metastatic effect against colon cancer in mice. Importantly, the humanized antibody may serve as a starting platf.

Proteinase 3 Induces Neuronal Cell Death Through Microglial Activation.

Proteinase 3 (PR3) is released from neutrophil granules and is involved in the inflammatory process. PR3 is implicated in antimicrobial defense and cell death, but the exact role of PR3 in the brain is less defined. Microglia is the major immune effector cells in the CNS and is activated by brain injury. In the present study, the effect of PR3 on glial activation was investigated. Microglial activation was assessed by the intracellular level of reactive oxygen species and expression of inflammatory cytokines. The conditioned media from activated microglia by PR3 was used for measuring the neurotoxic effects of PR3-stimulated microglia. The effects of PR3 in vivo were measured by microinjecting PR3 into the rat brain. Herein we show that PR3 increased the inflammatory responses including the intracellular ROS and pro-inflammatory cytokine production in rat primary microglia. Conditioned media from PR3-treated microglia induced neuronal cell death in a concentration dependent manner. Furthermore, microinjected PR3 into the striatum of the rat brain induced microglial activation and neuronal cell death. Interestingly treatment with anti-PR3 monoclonal antibody and protease inhibitors ameliorated microglial activation induced by PR3 in primary microglia and striatum, which also prevented neuronal cell death in both conditions. The data presented here suggest that PR3 is a direct modulator of microglial activation and causes neuronal death through the augmentation of inflammatory responses. We suggest that PR3 could be a new modulator of neuroinflammation, and blocking PR3 would be a promising novel therapeutic target for neuroinflammatory disease such as stroke and Alzheimer's disease.

Diabetes augments cognitive dysfunction in chronic cerebral hypoperfusion by increasing neuronal cell death: implication of cilostazol for diabetes mellitus-induced dementia.

Many patients with diabetes are at increased risk of cognitive dysfunction and dementia. Diabetes mellitus is a vascular risk factor that may increase the risk of dementia through its associations with vascular dementia. We tested whether cognitive impairment could be exacerbated in combined injury using a rat model of chronic cerebral hypoperfusion with diabetes. We also determined whether a potent inhibitor of type III phosphodiesterase could prevent the cognitive decline caused by this combined injury. We used Otsuka Long-Evans Tokushima Fatty (OLETF) rats as a model of type II diabetes (T2DM) and Long-Evans Tokushima Otsuka (LETO) rats as a control. Chronic cerebral hypoperfusion was modeled by permanent bilateral common carotid artery occlusion (BCCAO). At 24weeks, the non-diabetic and T2DM rats were randomly assigned into groups for the following experiments: analysis I (1) sham non-diabetic rats (n=8); (2) hypoperfused non-diabetic rats (n=9); (3) sham T2DM rats (n=8); (4) hypoperfused T2DM rats (n=9); analysis II- (1) sham T2DM rats without treatment (n=8); (2) cilostazol-treated T2DM rats (n=8); (3) hypoperfused T2DM rats (n=9); and (4) hypoperfused T2DM rats and cilostazol treatment (n=9). The rats were orally administered cilostazol (50mg/kg) or vehicle once a day for 2weeks after 24weeks. Rats performed Morris water maze tasks, and neuronal cell death and neuroinflammation were investigated via Western blots and histological investigation. Spatial memory impairment was exacerbated synergistically in the hypoperfused T2DM group compared with the hypoperfused non-diabetic group and sham T2DBM group (P<0.05). Compared with the control group, neuronal cell death was increased in the hippocampus of the hypoperfused T2DM group. Cilostazol, a PDE-3 inhibitor, improved the memory impairments through inhibition of neuronal cell death, activation of CREB phosphorylation and BDNF expression in the hypoperfused T2DM group. Our experimental results support the hypothesis that there are deleterious interactions between chronic cerebral hypoperfusion and T2DM. That is, metabolic diseases such as diabetes may exacerbate cognitive impairment in a rat model of vascular dementia. We also suggest that surprisingly, the phosphodiesterase III inhibitor, cilostazol may be useful for the treatment of cognitive impairment in diabetes mellitus-induced dementia. In conclusion, diabetes can aggravate cognitive dysfunction in vascular dementia, and PDE-3 inhibitors, such as cilostazol, may form the basis of a novel therapeutic strategy for diabetes-associated cognitive impairment or vascular dementia.

Effects of donepezil, an acetylcholinesterase inhibitor, on neurogenesis in a rat model of vascular dementia.

Vascular dementia (VaD) is the second most common form of dementia caused by cerebrovascular disease. Several recent reports demonstrated that cholinergic deficits are implicated in the pathogenesis of VaD and that cholinergic therapies have shown improvement of cognitive function in patients with VaD. However, the precise mechanisms by which donepezil achieves its effects on VaD are not fully understood. Donepezil hydrochloride is an acetylcholinesterase inhibitor (AChEI) currently used for the symptomatic treatment of Alzheimer's disease (AD). Several lines of evidence have demonstrated that AChEIs such as donepezil promote neurogenesis in the central nervous system. We investigated whether donepezil regulated hippocampal neurogenesis after bilateral common carotid artery occlusion (BCCAO) in rats, a commonly used animal model of VaD. To evaluate the effect of donepezil on neurogenesis, we orally treated rats with donepezil (10mg/kg) once a day for 3weeks, and injected BrdU over the same 3-week period to label newborn cells. The doses of donepezil that we used have been reported to activate cholinergic activity in rats. After 3weeks, a water maze task was performed on these rats to test spatial learning, and a subsequent histopathological evaluation was conducted. Donepezil improved memory impairment and increased the number of BrdU-positive cells in the dentate gyrus (DG) of BCCAO animals. These results indicated that donepezil improves cognitive function and enhances the survival of newborn neurons in the DG in our animal model of VaD, possibly by enhancing the expression of choline acetyltransferase and brain-derived neurotropic factor.

Valproic Acid Regulates α-Synuclein Expression through JNK Pathway in Rat Primary Astrocytes.

Although the role of α-synuclein aggregation on Parkinson's disease is relatively well known, the physiological role and the regulatory mechanism governing the expression of α-synuclein are unclear yet. We recently reported that α-synuclein is expressed and secreted from cultured astrocytes. In this study, we investigated the effect of valproic acid (VPA), which has been suggested to provide neuroprotection by increasing α-synuclein in neuron, on α-synuclein expression in rat primary astrocytes. VPA concentrationdependently increased the protein expression level of α-synuclein in cultured rat primary astrocytes with concomitant increase in mRNA expression level. Likewise, the level of secreted α-synuclein was also increased by VPA. VPA increased the phosphorylation of Erk1/2 and JNK and pretreatment of a JNK inhibitor SP600125 prevented the VPA-induced increase in α-synuclein. Whether the increased α-synuclein in astrocytes is involved in the reported neuroprotective effects of VPA awaits further investigation.

Proteinase 3 induces oxidative stress-mediated neuronal death in rat primary cortical neuron.

The recruitment of neutrophils into the cerebral microcirculation occurs, especially, in acute brain diseases like a focal cerebral ischemia and plays important role in pathological processes. Proteinase 3 is one of the three major proteinases expressed in neutrophils but no reports are available whether proteinase 3 can modulate neuronal survival. In this study, treatment of cultured rat primary cortical neuron with proteinase 3 induced overt reactive oxygen species production and decreased total glutathione contents as well as disruption of mitochondrial transmembrane potential. Proteinase 3 induced neuronal cell death as evidenced by MTT analysis as well as propidium iodide staining, which was prevented by pretreatment with an antioxidant, N-acetyl cysteine. Proteinase 3 increased activation of procaspase-3 and altered expression level of apoptotic regulator proteins, such as Bcl-2, Bax, and Bcl-xL. Similar to in vitro data, a direct microinjection of proteinase 3 into striatum of rat brain induced neuronal death, which was mediated by reactive oxygen species. These results suggest that proteinase 3 is new essential regulator of neuronal cell death pathway in a condition of excess neutrophil encounter in neuroinflammatory conditions.

Effects of Lizhong Tang on cultured mouse small intestine interstitial cells of Cajal.

AIM: To investigate the effects of Lizhong Tang, an herbal product used in traditional Chinese medicine, on mouse small intestine interstitial cells of Cajal (ICCs). METHODS: Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues. The ICCs were morphologically distinct from other cell types in culture and were identified using phase contrast microscopy after verification with anti c-kit antibody. A whole-cell patch-clamp configuration was used to record potentials (current clamp) from cultured ICCs. All of the experiments were performed at 30-32 °C. RESULTS: ICCs generated pacemaker potentials, and Lizhong Tang produced membrane depolarization in current-clamp mode. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by Lizhong Tang. Pretreatment with thapsigargin (a Ca²âº-ATPase inhibitor in the endoplasmic reticulum) also abolished the generation of pacemaker potentials by Lizhong Tang. However, pacemaker potentials were completely abolished in the presence of an external Ca²âº-free solution, and under this condition, Lizhong Tang induced membrane depolarizations. Furthermore, When GDP-ß-S (1 mmol/L) was in the pipette solution, Lizhong Tang still induced membrane depolarizations. In addition, membrane depolarizations were not inhibited by chelerythrine or calphostin C, which are protein kinase C inhibitors, but were inhibited by U-73122, an active phospholipase C inhibitors. CONCLUSION: These results suggest that Lizhong Tang might affect gastrointestinal motility by modulating pacemaker activity in interstitial cells of Cajal.

Neuroprotective effects of valproic acid against hemin toxicity: possible involvement of the down-regulation of heme oxygenase-1 by regulating ubiquitin-proteasomal pathway.

During hemorrhagic stroke induced by intracerebral hemorrhage (ICH), brain injury occurs from the deleterious actions of hemoglobin byproducts; induction of heme oxygenase-1 (HO-1) also plays a critical role in the neurotoxicity in ICH. Valproic acid (VPA), which is a commonly used drug in the treatment of epilepsy, has been reported to have neuroprotective effects against various neuronal insults including ischemic stroke. We investigated the effect of VPA on HO-1-mediated neurotoxicity in an experimental model of ICH. We investigated the effects of VPA on HO-1 protein in primary cortical neurons: (1) the expression levels of HO-1 mRNA and protein measured by RT-PCR and Western blotting; (2) the cell viability and ROS generation by MTT reduction assay and ROS measurement; (3) the signal pathway regulated by VPA using IP-Western blotting; (4) the effects of VPA on hemin-induced cell death by hemin microinjection and immunohistochemistry in vivo. VPA treatment partially blocked cell death induced by hemin, which is released from hemoglobin during ICH, both in rat primary cortical neurons and rat brain. Treatment of VPA significantly decreased the expression of HO-1 protein both in vitro and in vivo. Hemin treatment induced HO-1 protein expression and this was partially blocked by pretreatment with VPA, which might be mediated by increased ubiquitination and degradation of HO-1 via ERK1/2 and JNK activation in primary cortical neurons. Our results indicate that VPA inhibits hemin toxicity by downregulating HO-1 protein expression, and provide a therapeutic strategy to attenuate intracerebral hemorrhagic injury.

Modulation of pacemaker potentials by pyungwi-san in interstitial cells of cajal from murine small intestine: pyungwi-san and interstitial cells of cajal.

OBJECTIVE: Pyungwi-san (PWS) plays a role in a number of physiologic and pharmacologic functions in many organs. Interstitial cells of Cajal (ICCs) are pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. We aimed to investigate the beneficial effects of PWS in mouse small-intestinal ICCs. METHODS: Enzymatic digestion was used to dissociate ICCs from the small intestine of a mouse. The wholecell patch-clamp configuration was used to record membrane potentials from the cultured ICCs. RESULTS: ICCs generated pacemaker potentials in the GI tract. PWS produced membrane depolarization in the current clamp mode. Pretreatment with a Ca(2+) -free solution and a thapsigargin, a Ca(2+) -ATPase, inhibitor in the endoplasmic reticulum, eliminated the generation of pacemaker potentials. However, only when the thapsigargin was applied in a bath solution, the membrane depolarization was not produced by PWS. Furthermore, the membrane depolarizations due to PWS were inhibited not by U-73122, an active phospholipase C inhibitor, but by chelerythrine and calphostin C, protein kinase C inhibitors. CONCLUSIONS: These results suggest that PWS might affect GI motility by modulating the pacemaker activity in the ICCs.

Regulation of tissue plasminogen activator/plasminogen activator inhibitor-1 by hydrocortisone in rat primary astrocytes.

Although originally known as a plasma serine protease involved in clot dissolution, tPA and its primary inhibitor, PAI-1, play crucial roles in synaptic reorganization and plasticity in the central nervous system. In contrast to the wide array of work conducted in neural cells, relatively little is known about the regulatory mechanism governing tPA/PAI-1 expression in astrocytes. Glucocorticoids (GCs) such as hydrocortisone regulate the expression of tPA/PAI-1 in various biological systems in a tissue-specific manner. However, little is known about GC-mediated regulation of tPA/PAI-1 system in CNS. The aims of the present study were to investigate whether tPA/PAI-1 expression is regulated by hydrocortisone in rat primary astrocytes. Enzyme activity of tPA was decreased in a concentration-dependent manner by hydrocortisone treatment, and the activity of PAI-1 was increased by hydrocortisone. Hydrocortisone did not affect the level of tPA mRNA, which suggests that transcriptional down-regulation of tPA mRNA is not involved in the down-regulation of tPA enzyme activity in astrocytes. However, the level of PAI-1 mRNA and protein was increased. Both hydrocortisone and a tPA-Stop treatment prevented glutamate-induced neurotoxicity in rat cortical primary mixed astrocyte-neuron culture, which suggests a neurotoxic role for tPA in our culture system. Interestingly, hydrocortisone further increased LPS-induced up-regulation of PAI-1 while inhibiting the up-regulation of iNOS and COX-2 expression. Our data show that hydrocortisone up-regulated PAI-1 expression along with down-regulation of tPA activity in both normal and inflammatory conditions.

Melatonin synergistically increases resveratrol-induced heme oxygenase-1 expression through the inhibition of ubiquitin-dependent proteasome pathway: a possible role in neuroprotection.

Melatonin is an indoleamine secreted by the pineal gland as well as a plant-derived product, and resveratrol (RSV) is a naturally occurring polyphenol synthesized by a variety of plant species; both molecules act as a neuroprotector and antioxidant. Recent studies have demonstrated that RSV reduced the incidence of Alzheimer's disease and stroke, while melatonin supplementation was found to reduce the progression of the cognitive impairment in AD. The heme oxygenase-1 (HO-1) is an inducible and redox-regulated enzyme that provides tissue-specific antioxidant effects. We assessed whether the co-administration of melatonin and RSV shows synergistic effects in terms of their neuroprotective properties through HO-1. RSV significantly increased the expression levels of HO-1 protein in a concentration-dependent manner both in primary cortical neurons and in astrocytes, while melatonin per se did not. Melatonin + RSV showed a synergistic increase in the expression levels of HO-1 protein but not in the HO-1 mRNA level compared to either melatonin or RSV alone, which is mediated by the activation of PI3K-Akt pathway. Treatment of melatonin + RSV significantly attenuated the neurotoxicity induced by H(2) O(2) in primary cortical neurons and also in organotypic hippocampal slice culture. The blockade of HO-1 induction by shRNA attenuated HO-1 induction by melatonin + RSV and hindered the neuroprotective effects against oxidative stress induced by H(2) O(2) . The treatment of MG132 + RSV mimicked the effects of melatonin + RSV, and melatonin + RSV inhibited ubiquitination of HO-1. These data suggest that melatonin potentiates the neuroprotective effect of RSV against oxidative injury, by enhancing HO-1 induction through inhibiting ubiquitination-dependent proteasome pathway, which may provide an effective means to treat neurodegenerative disorders.