Adenosine Monophosphate Response Element-binding Protein Research Articles

Amelioration of lipopolysaccharide-induced memory impairment in equilibrative nucleoside transporter-2 knockout mice is accompanied by the changes in glutamatergic pathways

Neuroinflammation has been implicated in cognitive deficits in neurological and neurodegenerative diseases. Lipopolysaccharide (LPS)-induced neuroinflammation and the breakdown of the blood–brain barrier can be attenuated in mice with equilibrative nucleoside transporter-2 (ENT2/Ent2) deletion. The present study was aimed to investigate the role of ENT2 in cognitive and neuronal functions under physiological and inflammatory conditions, in terms of behavioral performance and synaptic plasticity in saline- and LPS-treated Ent2 knockout (KO) mice and their wild-type (WT) littermate controls. Repeated administrations of LPS significantly impaired spatial memory formation in Morris water maze and hippocampal-dependent long-term potentiation (LTP) in WT mice. The LPS-treated WT mice exhibited significant synaptic and neuronal damage in the hippocampus. Notably, the LPS-induced impairment in spatial memory and LTP performance were attenuated in Ent2 KO mice, along with the preservation of neuronal survival. The beneficial effects were accompanied by the normalization of excessive extracellular glutamate and aberrant downstream signaling of glutamate receptor activation, including the upregulation of phosphorylated p38 mitogen-activated protein kinase and the downregulation of phosphorylated cyclic adenosine monophosphate-response element-binding protein. There was no significant difference in behavioral outcome and all tested parameters between these two genotypes under physiological condition. These results suggest that ENT2 plays an important role in regulating inflammation-associated cognitive decline and neuronal damage.

Tachypacing-induced CREB/CD44 signaling contributes to the suppression of L-type calcium channel expression and the development of atrial remodeling.

Atrial fibrillation (AF), a common arrhythmia in clinics, is characterized as downregulation of L-type calcium channel (LTCC) and shortening of atrial action potential duration (APD). Our prior studies have shown the association of CD44 with AF genesis. The purpose of this study was to explore the potential role of CD44 and its related signaling in tachypacing-induced downregulation of LTCC. Invitro, tachypacing in atrium-derived myocytes (HL-1 cell line) induced activation (phosphorylation) of cyclic adenosine monophosphate response element-binding protein (CREB). Furthermore, tachypacing promoted an association between CREB and CD44 in HL-1 myocytes, which was documented in atrial tissues from patients with AF. Deletion and mutational analysis of the LTCC promoter along with chromatin immunoprecipitation revealed that cyclic adenosine monophosphate response element is essential for tachypacing-inhibited LTCC transcription. Tachypacing also hindered the binding of p-CREB to the promoter of LTCC. Blockade of CREB/CD44 signaling in HL-1 cells attenuated tachypacing-triggered downregulation of LTCC and shortening of APD. Atrial myocytes isolated from CD44-/- mice exhibited higher LTCC current and longer APD than did those from wild-type mice. Exvivo, tachypacing caused less activation of CREB in CD44-/- mice than in wild-type mice. Invivo, burst atrial pacing stimulated less inducibility of AF in CREB inhibitor-treated mice than in controls. Tachypacing-induced CREB/CD44 signaling contributes to the suppression of LTCC, which provides valuable information about the pathogenesis of atrial modeling and AF.

Beta 2-adrenergic receptor mediates noradrenergic action to induce cyclic adenosine monophosphate response element-binding protein phosphorylation in satellite glial cells of dorsal root ganglia to regulate visceral hypersensitivity.

Sympathoneuronal outflow into dorsal root ganglia (DRG) is suggested to be involved in sympathetically maintained chronic pain, which is mediated by norepinephrine (NE) action on DRG cells. This study combined in vitro and in vivo approaches to identify the cell types of DRG that received NE action and examined cell type-specific expression of adrenergic receptors (ARs) in DRG. Using DRG explants, we identified that NE acted on satellite glial cells (SGCs) to induce the phosphorylation of cAMP response element-binding protein (CREB). Using primarily cultured SGCs, we identified that beta (β)2-adrenergic receptor but not alpha (α)adrenergic receptor nor other βAR isoforms mediated NE-induced CREB phosphorylation and CRE-promoted luciferase transcriptional activity. Using fluorescence in situ hybridization and affinity purification of mRNA from specific cell types, we identified that β2AR was expressed by SGCs but not DRG neurons. We further examined β2AR expression and CREB phosphorylation in vivo in a model of colitis in which sympathetic nerve sprouting in DRG was observed. We found that β2AR expression and CREB phosphorylation were increased in SGCs of thoracolumbar DRG on day 7 after colitis induction. Inhibition but not augmentation of β2AR reduced colitis-induced calcitonin gene-related peptide release into the spinal cord dorsal horn and colonic pain responses to colorectal distention. Prolonged activation of β2AR in naive DRG increased calcitonin gene-related peptide expression in DRG neurons. These findings provide molecular basis of sympathetic modulation of sensory activity and chronic pain that involves β2AR-mediated signaling in SGCs of DRG.

LIFU Alleviates Neuropathic Pain by Improving the KCC2 Expression and Inhibiting the CaMKIV-KCC2 Pathway in the L4-L5 Section of the Spinal Cord.

Effective treatment remains lacking for neuropathic pain (NP), a type of intractable pain. Low-intensity focused ultrasound (LIFU), a noninvasive, cutting-edge neuromodulation technique, can effectively enhance inhibition of the central nervous system (CNS) and reduce neuronal excitability. We investigated the effect of LIFU on NP and on the expression of potassium chloride cotransporter 2 (KCC2) in the spinal cords of rats with peripheral nerve injury (PNI) in the lumbar 4–lumbar 5 (L4–L5) section. In this study, rats received PNI surgery on their right lower legs followed by LIFU stimulation of the L4–L5 section of the spinal cord for 4 weeks, starting 3 days after surgery. We used the 50% paw withdraw threshold (PWT50) to evaluate mechanical allodynia. Western blotting (WB) and immunofluorescence (IF) were used to calculate the expression of phosphorylated extracellular signal–regulated kinase 1/2 (p-ERK1/2), calcium/calmodulin-dependent protein kinase type IV (CaMKIV), phosphorylated cyclic adenosine monophosphate response element-binding protein (p-CREB), and KCC2 in the L4–L5 portion of the spinal cord after the last behavioral tests. We found that PWT50 decreased (P < 0.05) 3 days post-PNI surgery in the LIFU− and LIFU+ groups and increased (P < 0.05) after 4 weeks of LIFU stimulation. The expression of p-CREB and CaMKIV decreased (P < 0.05) and that of KCC2 increased (P < 0.05) after 4 weeks of LIFU stimulation, but that of p-ERK1/2 (P > 0.05) was unaffected. Our study showed that LIFU could effectively alleviate NP behavior in rats with PNI by increasing the expression of KCC2 on spinal dorsal corner neurons. A possible explanation is that LIFU could inhibit the activation of the CaMKIV–KCC2 pathway.

BAY 73-6691 Alters Neuron Plasticity and Phosphorylation of Tau Through Regulation of Cyclic Guanosine Monophosphate/Protein Kinase G/Cyclic Adenosine Monophosphate Response Element-Binding Protein Pathway

Alzheimer’s disease (AD) is one of neurodegenerative diseases characterized by cognitive and memory decline, accompanying with neurofibrillary tangles (NFTs) made of hyperphosphorylated tau protein and senile plaques (SP) accumulated by β-amyloid protein (Aβ). BAY 73-6691, an inhibitor of phosphodiesterase-9 (PDE-9), can improve learning and memory of elderly rats. However, the effects of BAY 73-6691 on neuroapoptotic and neuroinflammatory events, as well as synaptic plasticity of differentiated PC12 cells are remain unclear. In this work, we screened apoptotic cells induced by Aβ25-35 via flow cytometry. TNF-α, IL-1β, IL-6 secreted by PC12 cells were estimated by ELISA kits. The levels of cGMP, PKG and CREB mediated by BAY 73-6691 were assessed. Moreover, we conducted western blots analysis to evaluate the phosphorylation of tau and synaptic related proteins. Results showed that BAY 73-6691 could reduce Aβ25-35-triggered neuroapoptosis and neuroinflammation. Phosphorylation of tau was inhibited by BAY 73-6691, whereas sildenafil citrate (SC, an inhibitor of cGMP) partially weakened the effect of BAY 73-6691. Additionally, synaptic plasticity restored by BAY 73-6691 was also suppressed via SC. Taken together, BAY 73-6691 exhibited neuro protective effects, and altered tau phosphorylation as well as synaptic related proteins through cGMP/PKG/CREB pathway.

Predicting a Potential Link to Antidepressant Effect: Neuroprotection of Zhi-zi-chi Decoction on Glutamate-induced Cytotoxicity in PC12 Cells.

Zhi-zi-chi Decoction (ZZCD), composed of Fructus Gardeniae (Zhizi in Chinese, ZZ in brief) and Semen sojae praeparatum (Dandouchi in Chinese, DDC in brief), has been used as a drug therapy for depression for thousands of years in China. However, the antidepressant mechanism of ZZCD still remains unknown. This study was aimed at exploring antidepressant effects of ZZCD from the aspect of neuroprotection based on herb compatibility. Glutamate-treated PC12 cells and chronic unpredictable mild stress (CUMS)-induced rats were established as models of depression in vitro and in vivo respectively. Cell viability, lactate dehydrogenase (LDH), apoptosis rate, reactive oxygen species (ROS), glutathione reductase (GR) and superoxide dismutase (SOD), and the expressions of Bax, Bcl-2 and cyclic adenosine monophosphate-response element binding protein (CREB) were measured to compare neuroprotection among single herbs and the formula in vitro. Behavior tests were conducted to validate antidepressant effects of ZZCD in vivo. Results showed that the compatibility of ZZ and DDC increased cell viability and activities of GR and SOD, and decreased the levels of LDH, apoptosis cells and ROS. Besides, the expressions of Bcl-2 and CREB were up-regulated while that of Bax was down-regulated by ZZCD. Furthermore, the compatibility of ZZ and DDC reversed abnormal behaviors in CUMS-induced rats and displayed higher efficacy than any of the single herbs. This study revealed that the antidepressant effects of ZZCD were closely associated with neuroprotection and elucidated synergistic effects of the compatibility of ZZ and DDC based on it.

Effects of Dexmedetomidine on Rats with Functional Chronic Visceral Pain Based on Protein Expressions in the Extracellular Signal-Regulated Kinase 1/Cyclic Adenosine Monophosphate Response Element-Binding Protein Signaling Pathway

To evaluate the protective effects of dexmedetomidine on the colon and spinal cord of rats with functional chronic visceral pain and its regulatory mechanism on extracellular signal-regulated kinase 1-cyclic adenosine monophosphate response element-binding protein signaling pathway. A rat model of irritable bowel syndrome was established by colorectal distention stimulation. Animals were categorized into normal group, model group, experimental group and control group. No treatment was given in normal group, while colorectal distention stimulation was utilized in model group, experimental group and control group. After successful modeling, the animals in experimental group were injected intraperitoneally with 5 μg/kg of dexmedetomidine hydrochloride injection daily, those in control group were injected intraperitoneally with 5 μg/kg pinaverium bromide daily and those in normal group and model group were injected intraperitoneally daily with the same volume of normal saline, for 14 consecutive days. Abdominal withdrawal reflex score and pain threshold of rats were measured. Cell apoptosis in the spinal cord of rats was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining. The messenger ribonucleic acid expressions of extracellular signal-regulated kinase 1 and cyclic adenosine monophosphate response element-binding protein in the spinal cord were detected by realtime quantitative polymerase chain reaction and phosphorylated-extracellular signal-regulated kinase 1 and phosphorylated-cyclic adenosine monophosphate response element-binding protein expressions in the spinal cord of rats were tested by Western blotting. Compared with normal group, abdominal withdrawal reflex score, cell apoptosis rate, messenger ribonucleic acid expressions of extracellular signal-regulated kinase 1 and cyclic adenosine monophosphate response element-binding protein, phosphorylatedextracellular signal-regulated kinase 1 and phosphorylated-cyclic adenosine monophosphate response element-binding protein expressions were significantly higher (p<0.05) and pain threshold value was significantly lower (p<0.05) in model group, experimental group and control group at 20 mmHg, 40 mmHg, 60 mmHg and 80 mmHg pressures. Abdominal withdrawal reflex score, cell apoptosis rate, messenger ribonucleic acid expressions of extracellular signal-regulated kinase 1 and cyclic adenosine monophosphate response element-binding protein, phosphorylated-extracellular signal-regulated kinase 1 and phosphorylated-cyclic adenosine monophosphate response element-binding protein expressions were significantly lower (p<0.05) and pain threshold value was significantly higher (p<0.05) in experimental group and control group than those in model group at 20 mmHg, 40 mmHg, 60 mmHg and 80 mmHg pressures. Dexmedetomidine can prominently ameliorate the clinical symptoms of rats with functional chronic visceral pain and may protect the colon and spinal cord by inhibiting the extracellular signalregulated kinase 1/cyclic adenosine monophosphate response element-binding protein signaling pathway.

Cerebrospinal Fluid Level of Phosphorylated Neurofilament Heavy Chain is Higher in Converting Clinically Isolated Syndrome and Correlates with CAMP Response Element-Binding Protein Concentration

Introduction: Prevision of conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS) is required to avoid unnecessary use of immunomodulating agents and to recognize patients with high disease activity. Our aim was to evaluate the value of phosphorylated neurofilament heavy chain (pNFH, a marker for neuroaxonal degeneration) and Cyclic adenosine monophosphate response element-binding protein (cAMP response element-binding protein [CREB], a marker for neuroregeneration) levels in the prediction of conversion from CIS to MS. Methods: Twenty-three consecutively recruited treatment-naïve CIS patients were followed for 36 months. pNFH and CREB levels were measured in the first episode cerebrospinal fluid (CSF) and the serum of 12 converting (CIS-MS) and 11 nonconverting CIS patients (CIS-CIS) by enzyme-linked immunosorbent assay. Results: Baseline CSF but not serum samples of CIS-CIS patients displayed significantly lower pNFH levels compared to patients with CIS-MS. The analysis of receiver operating characteristic curve presented a high specificity for the prediction of MS conversion for the CSF pNFH cut-off level of 730.9 pg/ml. CSF pNFH levels significantly correlated with serum and CSF CREB levels. Higher baseline CSF pNFH and CREB levels were associated with more rapid progression to MS or increased disability scores. Conclusion: CSF pNFH measurement may potentially determine MS patients with unfavorable clinical progression after the first attack. pNFH and CREB appear to be increased in parallel in CSF of CIS patients with higher disease activity. These results suggest that neurofilaments are not only indicators of axonal degeneration but also partly a marker of neuronal differentiation and new axon regeneration mediated by CREB signaling pathway.

Pentoxifylline Enhances Antioxidative Capability and Promotes Mitochondrial Biogenesis in D‐Galactose‐Induced Aging Mice by Increasing Nrf2 and PGC‐1α through the cAMP‐CREB Pathway

Aging is a complex phenomenon associated with oxidative stress and mitochondrial dysfunction. The objective of this study was to investigate the potential ameliorative effects of the phosphodiesterase inhibitor pentoxifylline (PTX) on the aging process and its underlying mechanisms. We treated D-galactose- (D-gal-) induced aging mice with PTX and measured the changes in behavior, degree of oxidative damage, and mitochondrial ultrastructure and content as well as the expression of nuclear factor erythroid 2-related factor 2- (Nrf2-) mediated antioxidant genes and peroxisome proliferator-activated receptor-gamma coactivator 1-alpha- (PGC-1α-) dependent mitochondrial biogenesis genes. The results demonstrated that PTX improved cognitive deficits, reduced oxidative damage, ameliorated abnormal mitochondrial ultrastructure, increased mitochondrial content and Nrf2 activation, and upregulated antioxidant and mitochondrial biogenesis gene expression in the hippocampus of wild-type aging mice. However, the above antiaging effects of PTX were obviously decreased in the brains of Nrf2-deficient D-gal-induced aging mice. Moreover, in hydrogen peroxide-treated SH-SY5Y cells, we found that cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) and Nrf2/PGC-1α act in a linear way by CREB siRNA transfection. Thus, PTX administration improved the aging-related decline in brain function by enhancing antioxidative capability and promoting mitochondrial biogenesis, which might depend on increasing Nrf2 and PGC-1α by activating the cAMP-CREB pathway.

Cyclic AMP response element-binding protein is required in excitatory neurons in the forebrain to sustain wakefulness

The molecular and intracellular signaling processes that control sleep and wake states remain largely unknown. A consistent observation is that the cyclic adenosine monophosphate (AMP) response element-binding protein (CREB), an activity-dependent transcription factor, is differentially activated during sleep and wakefulness. CREB is phosphorylated by the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway as well as other kinases, and phosphorylated CREB promotes the transcription of target genes. Genetic studies in flies and mice suggest that CREB signaling influences sleep/wake states by promoting and stabilizing wakefulness. However, it remains unclear where in the brain CREB is required to drive wakefulness. In rats, CREB phosphorylation increases in the cerebral cortex during wakefulness and decreases during sleep, but it is not known if this change is functionally relevant to the maintenance of wakefulness. Here, we used the Cre/lox system to conditionally delete CREB in the forebrain (FB) and in the locus coeruleus (LC), two regions known to be important for the production of arousal and wakefulness. We used polysomnography to measure sleep/wake levels and sleep architecture in conditional CREB mutant mice and control littermates. We found that FB-specific deletion of CREB decreased wakefulness and increased non-rapid eye movement sleep. Mice lacking CREB in the FB were unable to sustain normal periods of wakefulness. On the other hand, deletion of CREB from LC neurons did not change sleep/wake levels or sleep/wake architecture. Taken together, these results suggest that CREB is required in neurons within the FB but not in the LC to promote and stabilize wakefulness.

Metabotropic glutamate receptor 5 regulates synaptic plasticity in a chronic migraine rat model through the PKC/NR2B signal

BackgroundThe mechanism of chronic migraine (CM) is complex, central sensitization is considered as one of the pathological mechanism. Synaptic plasticity is the basis of central sensitization. Metabotropic glutamate receptor 5 (mGluR5) plays a vital role in the synaptic plasticity of the central nervous system. However, whether mGluR5 can promote the central sensitization by regulating synaptic plasticity in CM is unknown.MethodsMale Wistar rats were used to establish a CM rat model, and the expression of mGluR5 mRNA and protein were detected by qRT-PCR and western blot. The allodynia was assessed by mechanical and thermal thresholds, and central sensitization was assessed by expression of the phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) at Serine 133(pCREB-S133) and c-Fos. The synaptic-associated protein postsynaptic density protein 95 (PSD), synaptophysin (Syp), and synaptophysin-1(Syt-1), synaptic ultrastructure, and dendritic spines were detected to explore synaptic plasticity. The expression of PKC, total NR2B(tNR2B), and phosphorylation of NR2B at Tyr1472(pNR2B-Y1472) were detected by western blot.ResultsWe found that the expression of mGluR5 was upregulated in CM rats. Downregulated the mGluR5 with MPEP alleviated the allodynia and reduced the expression of CGRP, pCREB-S133, c-Fos, PSD, Syp and Syt-1 and synaptic transmission. Moreover, the administration of MPEP inhibited the upregulation of PKC and pNR2B-Y1472.ConclusionsThese results indicate that mGluR5 contributes to central sensitization by regulating synaptic plasticity in CM through the PKC/NR2B signal, which suggests that mGluR5 may be a potential therapeutic candidate for CM.

Novel role of CXCL14 in modulating STAR expression in luteinized granulosa cells: implication for progesterone synthesis in PCOS patients

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive-age women. Reduced progesterone levels are associated with luteal phase deficiency in women with PCOS. The levels of C-X-C motif chemokine ligand-14 (CXCL14) were previously reported to be decreased in human-luteinized granulosa (hGL) cells derived from PCOS patients. However, the function of CXCL14 in hGL cells and whether CXCL14 affects the synthesis of progesterone in hGL cells remain unclear. In the present study, the levels of CXCL14 were reduced in follicular fluid and hGL cells in PCOS patients, accompanied by decreased progesterone levels in follicular fluid and decreased steroidogenic acute regulatory (STAR) expression in hGL cells. CXCL14 administration partially reversed the low progesterone production and STAR expression in hGL cells obtained from PCOS patients. In primary hGL cells, CXCL14 upregulated STAR expression and progesterone production. CXCL14 activated the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB) and CREB inhibitor attenuated the modulation of StAR expression by CXCL14. P38 and Jun N-terminal kinase (JNK) pathways were also activated by CXCL14 and inhibition of p38 and JNK attenuated the increase of phosphorylation of CREB, STAR expression and progesterone production caused by CXCL14. Our findings revealed the novel role of CXCL14 in upregulation of STAR expression and progesterone synthesis through CREB phosphorylation via activation of p38 and JNK pathways in hGL cells. This is likely contributing to the dysfunction in steroidogenesis in granulosa cells from PCOS patients.

Cysteine Sulfoxides Enhance Steroid Hormone Production via Activation of the Protein Kinase A Pathway in Testis-Derived I-10 Tumor Cells

Testosterone plays an important role in male sexual characteristics and maturation, and decreased testosterone levels increase the risk of several diseases. Recently, onion extract rich in cysteine sulfoxides, which are amino acids unique to onions, has been reported to alleviate age-related symptoms resulting from decreased testosterone levels in males. However, the mechanism underlying the suppression of low testosterone levels by cysteine sulfoxides has not been elucidated. In this study, we found that onion extract containing cysteine sulfoxides enhanced progesterone, a precursor of testosterone, in mouse testis-derived I-10 tumor cells. Furthermore, cysteine sulfoxides activated protein kinase A (PKA) and cyclic adenosine monophosphate response element-binding protein, which are key factors in steroidogenesis. These results suggest that cysteine sulfoxides enhance steroid hormone production via activation of the PKA signaling pathway.

The Effects of Calcitonin Gene-Related Peptide on Bone Homeostasis and Regeneration.

The goals of this review are two folds: (1) to describe the recent understandings on the roles of calcitonin gene-related peptide-α (CGRP) in bone homeostasis and the underlying mechanisms of related neuronal regulation and (2) to propose innovative CGRP-modulated approaches for enhancing bone regeneration in challenging bone disorders. CGRP is predominantly produced by the densely distributed sensory neuronal fibers in bone, declining with age. Under mechanical and biochemical stimulations, CGRP releases and exerts either physiological or pathophysiological roles. CGRP at physiological level orchestrates the communications of bone cells with cells of other lineages, affecting not only osteogenesis, osteoclastogenesis, and adipogenesis but also angiogenesis, demonstrating with pronounced anabolic effect, thus is essential for maintaining bone homeostasis, with tuned nerve-vessel-bone network. In addition, its effects on immunity and cell recruitment are also crucial for bone fracture healing. Binding to the G protein-coupled receptor composited by calcitonin receptor-like receptor (CRLR) and receptor activity modifying protein 1 (RAMP1) on cellular surface, CGRP triggers various intracellular signaling cascades involving cyclic adenosine monophosphate (cAMP) and cAMP response element-binding protein (CREB). Peaking at early stage post-fracture, CGRP promotes bone formation, displaying with larger callus. Then CGRP gradually decreases over time, allowing normal or physiological bone remodeling. By elevating CGRP at early stage, low-intensity pulsed ultrasound (LIPUS), electrical stimulation, and magnesium-based bio-mineral products may promisingly accelerate bone regeneration experimentally in medical conditions like osteoporosis, osteoporotic fracture, and spine fusion. Excess CGRP expression is commonly observed in pathological conditions including cancer metastatic lesions in bone and fracture delayed- or non-healing, resulting in persistent chronic pain. To date, these discoveries have largely been limited to animal models. Clinical applications are highly desirable. Compelling evidence show the anabolic effects of CGRP on bone in animals. However, further validation on the role of CGRP and the underlying mechanisms in human skeletons is required. It remains unclear if it is type H vessel connecting neuronal CGRP to osteogenesis, and if there is only specific rather than all osteoprogenitors responsible to CGRP. Clear priority should be put to eliminate these knowledge gaps by integrating with high-resolution 3D imaging of transparent bulk bone and single-cell RNA-sequencing. Last but not the least, given that small molecule antagonists such as BIBN4096BS can block the beneficial effects of CGRP on bone, concerns on the potential side effects of humanized CGRP-neutralizing antibodies when systemically administrated to treat migraine in clinics are arising.

The Effects of Crinum asiaticum var. japonicum Baker Seeds on Neuroprotection and Antineuroinflammation in Neuronal Cell Lines

Crinum asiaticum var. japonicum Baker is a Korean herbal medicine that is traditionally prescribed for reducing fever and inflammation. In the present study, we investigated if the ethanol extract of C. asiaticum seeds (ECAS) influences the hallmarks of Alzheimer’s disease (AD) pathogenesis. ECAS markedly inhibited the activity of acetylcholinesterase (AChE). Concurrent treatment with hydrogen peroxide (H2O2) and ECAS significantly prevented the neuronal cell death by regulating phosphorylation of cyclic adenosine monophosphate response element-binding protein and p38 mitogen-activated protein kinase. ECAS revealed antineuroinflammatory effects by inhibiting nitric oxide production and suppressing inducible nitric oxide expression in lipopolysaccharide-stimulated BV-2 microglia. Furthermore, the high-performance liquid chromatographic analysis determined lycorine as a standard compound of ECAS. Our data suggest that ECAS has inhibitory effects on AD pathogenesis such as AChE activation, neuronal damage, and neuroinflammation.

Positive regulation of the CREB phosphorylation via JNK-dependent pathway prevents antimony-induced neuronal apoptosis in PC12 cell and mice brain

Antimony (Sb) is a potentially toxic chemical element abundantly found in the environment. We previously reported that Sb promoted neuronal deathvia reactive oxygen species-dependent autophagy. Here, we assessed the role of cyclic adenosine monophosphate response element-binding protein (CREB) in Sb-induced neuronal damage. We found that Sb treatment induced CREB phosphorylation and neuronal apoptosis both in vitro and in vivo. Interestingly, inhibition of CREB’s transcriptional activity with 666−15 dramatically enhanced apoptosis in PC12 cells by downregulating B-cell lymphoma 2 (Bcl-2). Additionally, Sb activated ERK, JNK, and p38 signaling ; however, only JNK promoted CREB phosphorylation. In conclusion, our findings suggest that CREB phosphorylation by JNK attenuates Sb-induced neuronal apoptosis via Bcl-2 upregulation. These data suggest that JNK-dependent CREB activation prevents neurons from Sb-induced apoptosis and guides the development of novel strategies to prevent Sb-induced neurotoxicity.

Antitumor activity of the dual BET and CBP/EP300 inhibitor NEO2734

AbstractBromodomain and extra-terminal domain (BET) proteins, cyclic adenosine monophosphate response element-binding protein (CBP), and the E1A-binding protein of p300 (EP300) are important players in histone acetylation. Preclinical evidence supports the notion that small molecules targeting these proteins individually or in combination can elicit antitumor activity. Here, we characterize the antitumor activity of the pan BET/CBP/EP300 inhibitor NEO2734 and provide insights into its mechanism of action through bromodomain-binding assays, in vitro and in vivo treatments of cancer cell lines, immunoblotting, and transcriptome analyses. In a panel of 60 models derived from different tumor types, NEO2734 exhibited antiproliferative activity in multiple cell lines, with the most potent activity observed in hematologic and prostate cancers. Focusing on lymphoma cell lines, NEO2374 exhibited a pattern of response and transcriptional changes similar to lymphoma cells exposed to either BET or CBP/EP300 inhibitors alone. However, NEO2734 was more potent than single-agent BET or CBP/EP300 inhibitors alone. In conclusion, NEO2734 is a novel antitumor compound that shows preferential activity in lymphomas, leukemias, and prostate cancers.

Effect of Obesity on Cognitive Impairment in Vascular Dementia Rat Model via BDNF-ERK-CREB Pathway.

The prevalence of vascular dementia continues to increase with no cure. Thus, it is important identify the aggravating factors of vascular dementia to delay disease progression in patients. Obesity is a well-known risk factor for vascular dementia and causes mild cognitive impairment. In the present study, we evaluated whether obesity exacerbates cognitive impairment in vascular dementia rats and how it affects synaptic plasticity through the BDNF pathway. We randomly assigned 30 Wistar male rats to three groups: sham surgery (Sham), vascular dementia (VaD), and vascular dementia with obesity (OB + VaD). We fed rats a 60% high-fat diet to establish obesity; we then induced vascular dementia using bilateral common carotid artery occlusion. After 6 weeks, we evaluated cognitive function using the Morris water maze and radial arm maze tests. We analyzed post-synaptic density-95 (PSD95) and growth-associated protein-43 (GAP43) to confirm synaptic plasticity. We also evaluated brain-derived neurotrophic factor (BDNF), phosphorylated extracellular signal-regulated kinase (pERK), and phosphorylated cyclic adenosine monophosphate response element-binding protein (pCREB) in the hippocampus. The OB + VaD group showed the most impaired cognitive function on behavioral tests, with decreases in PSD95. The VaD group showed increased levels of BDNF, pERK, and pCREB, while the OB + VaD group displayed decreased levels. We suggest that obesity exacerbates cognitive impairment in vascular dementia by inhibiting the compensatory increases of BDNF-ERK-CREB pathway.

Dietary γ-Glutamyl Valine Ameliorates TNF-α-Induced Vascular Inflammation via Endothelial Calcium-Sensing Receptors.

γ-Glutamyl valine (γ-EV), commonly found in edible beans, was shown to reduce gastrointestinal inflammation via activation of calcium-sensing receptors (CaSRs). The present study aimed to evaluate the efficacy of γ-EV in modulating the tumor necrosis factor-α-induced inflammatory responses in endothelial cells (ECs) via CaSR-mediated pathways. Human aortic ECs (HAoECs) were pretreated (2 h) with γ-EV (0.01, 0.1, and 1 mM). 1 mM pretreatment of γ-EV significantly reduced the upregulation of inflammatory adhesion molecules, VCAM-1 and E-selectin, by 44.56 and 57.41%, respectively. The production of cytokines IL-8 and IL-6 was significantly reduced by 40 and 51%, respectively, with 1 mM pretreatment of γ-EV. Similarly, there was a significant reduction in chemokine MCP-1 from a positive control of 9.70 ± 0.52 to 6.6 ± 0.43 ng/mL, after γ-EV treatment. The anti-inflammatory effect of γ-EV was attenuated by the treatment of the CaSR-specific inhibitor, NPS-2143, suggesting the involvement of CaSR-mediated pathways. Further studies identified the critical role of key modulators, such as β-arrestin2 and cyclic adenosine monophosphate response element-binding protein, in mediating the CaSR-dependent anti-inflammatory effect of γ-EV. Finally, the transport efficiency of γ-EV was evaluated through a monolayer of intestinal epithelial cells (Caco-2), and the apparent permeability (Papp) of the peptide was found to be 1.56 × 10-6 cm/s.

Neurophysiologic implications of neuronal nitric oxide synthase.

The molecular and chemical properties of neuronal nitric oxide synthase (nNOS) have made it a key mediator in many physiological functions and signaling transduction. The NOS monomer is inactive, but the dimer form is active. There are three forms of NOS, which are neuronal (nNOS), inducible (iNOS), and endothelial (eNOS) nitric oxide synthase. nNOS regulates nitric oxide (NO) synthesis which is the mechanism used mostly by neurons to produce NO. nNOS expression and activation is regulated by some important signaling proteins, such as cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB), calmodulin (CaM), heat shock protein 90 (HSP90)/HSP70. nNOS-derived NO has been implicated in modulating many physiological functions, such as synaptic plasticity, learning, memory, neurogenesis, etc. In this review, we have summarized recent studies that have characterized structural features, subcellular localization, and factors that regulate nNOS function. Finally, we have discussed the role of nNOS in the developing brain under a wide range of physiological conditions, especially long-term potentiation and depression.