Neural Cell Adhesion Molecule Levels Research Articles

CSIG-14. ACROLEIN INDUCES THE MIR-30A-5P/NCAM AXIS THROUGH THE AKT/GSK3Β/Β-CATENIN PATHWAY, PROMOTING GLIOMA PROGRESSION

Abstract Glioblastoma (GBM), the most aggressive brain tumor, exhibits resistance to treatment and thrives in low-oxygen (hypoxic) environments, leading to the accumulation of reactive oxygen species (ROS). Hypoxia activates the hypoxia-inducible factor (HIF)-1α pathway, enhancing tumor malignancy. Acrolein, a reactive aldehyde produced during lipid peroxidation in hypoxia, induces toxicity through DNA damage, inflammation, mitochondrial dysfunction, and oxidative stress. Our previous study found elevated acrolein levels in hypoxic glioma cells and linked acrolein-induced DNA damage (Acr-dG) with poor GBM prognosis. However, the role of acrolein in GBM progression remains unclear. This study aims to elucidate the impact of acrolein on GBM. In vitro experiments demonstrated acrolein production under hypoxia, which increased glioma cell migration and spheroid formation. RNA sequencing identified five affected pathways: cell adhesion molecules, PI3K-AKT signaling, ECM-receptor interaction, MAPK signaling, and neuroactive ligand-receptor interaction. Acrolein downregulated NCAM (neural cell adhesion molecule) via the miR-30a-5p-AKT-GSK3β/β-catenin axis in GBM cell lines and patient-derived cells. Overexpressing NCAM reduced cell migration and spheroid formation. Lower NCAM levels in GBM tissues correlated with poor patient survival. This study suggests the potential of NCAM as a therapeutic target for GBM and provides insights into early detection and treatment strategies for this malignancy.

CSIG-15. ACROLEIN INDUCES THE MIR-30A-5P/NCAM AXIS VIA THE AKT/GSK3Β/Β-CATENIN PATHWAY, PROMOTING GLIOMA PROGRESSION

Abstract Glioblastoma (GBM), the most aggressive brain tumor, exhibits resistance to treatment and thrives in low-oxygen (hypoxic) environments, leading to the accumulation of reactive oxygen species (ROS). Hypoxia activates the hypoxia-inducible factor (HIF)-1α pathway, enhancing tumor malignancy. Acrolein, a reactive aldehyde produced during lipid peroxidation in hypoxia, induces toxicity through DNA damage, inflammation, mitochondrial dysfunction, and oxidative stress. Our previous study found elevated acrolein levels in hypoxic glioma cells and linked acrolein-induced DNA damage (Acr-dG) with poor GBM prognosis. However, the role of acrolein in GBM progression remains unclear. This study aims to elucidate the impact of acrolein on GBM. In vitro experiments demonstrated acrolein production under hypoxia, which increased glioma cell migration and spheroid formation. RNA sequencing identified five affected pathways: cell adhesion molecules, PI3K-AKT signaling, ECM-receptor interaction, MAPK signaling, and neuroactive ligand-receptor interaction. Acrolein downregulated NCAM (neural cell adhesion molecule) via the miR-30a-5p-AKT-GSK3β/β-catenin axis in GBM cell lines and patient-derived cells. Overexpressing NCAM reduced cell migration and spheroid formation. Lower NCAM levels in GBM tissues correlated with poor patient survival. This study suggests the potential of NCAM as a therapeutic target for GBM and provides insights into early detection and treatment strategies for this malignancy.

Decreased Serum NCAM Levels Associated with Cognitive Impairment in Vascular Dementia.

Objective Neural cell adhesion molecule (NCAM), a glycoprotein widely distributed in the brain, has recently been shown to regulate neuroplasticity. However, the role of NCAM in vascular dementia (VaD) is still unclear. The purpose of this study is to determine whether NCAM is involved in the course of VaD. Methods Continuous recruitment of VaD patients and control population to join this study. Doctors or nurses are responsible for collecting their clinical characteristics including age, gender, formal education, heart rate, supine systolic blood pressure, supine diastolic blood pressure, fasting glucose, high-density lipoprotein, and low-density lipoprotein. Each participant received the Montreal Cognitive Assessment (MoCA) scale after being enrolled in the group. At the same time, their peripheral blood was collected, and their serum NCAM levels were measured by enzyme-linked immunosorbent assay (ELISA). Results 98 VaD patients and 83 age- and sex-matched controls were enrolled. There was no significant statistical difference between the VaD group and the control group in terms of the comparison of clinical characteristics (p > 0.05). The MoCA score of VaD patients was significantly lower than that of the controls (27.9 ± 1.4 vs. 23.0 ± 2.1 points, p < 0.001). In addition, the circulating NCAM level of VaD patients was also significantly lower than that of controls (21.7 ± 3.8 vs. 17.6 ± 4.2 ng/mL, p < 0.001). The circulating NCAM level of VaD patients was significantly positively correlated with MoCA score (r = 0.285, p = 0.026). After adjusting for clinical characteristics, circulating NCAM levels are still an independent pathogenic factor of VaD (regression coefficient = 0.223, p = 0.034). Conclusions VaD patients have low circulating NCAM levels, which can be used as a potential predictor of VaD.

The Role of Forced and Voluntary Training on Accumulation of Neural Cell Adhesion Molecule and Polysialic Acid in Muscle of Mice with Experimental Autoimmune Encephalomyelitis.

It has been suggested that depletion of adhesion molecules is one of the factors associated with or possibly responsible for multiple sclerosis (MS) progression. The aim of this study was to investigate the effect of forced and voluntary training before and after induction of experimental autoimmune encephalomyelitis (EAE) on accumulation of neural cell adhesion molecule (NCAM) and polysialic acid (PSA) in neuromuscular junction denervation in plantaris and soleus muscles in C57BL/6 female mice. A total of 40 female C57BL/6 mice, 10-week-old, were randomly divided into four groups, including induced control groups without EAE induction, induced EAE without training, and forced and voluntary training groups. Myelin oligodendrocyte glycoprotein peptide 35–55 (300 μg in saline; MOG 35–55; KJ Ross-Petersen ApS, Denmark) was injected subcutaneously at the base of the tail of each mouse. Clinical assessment of EAE was performed daily using a 15-point scoring system following immunization. Training groups performed the swimming program for 30 min/day, 5 times/week, for 4 weeks. Mice had access to a treadmill for one hour per day, 5times/week, for 4 weeks in individual cage. The mice were scarified, and the plantaris and soleus muscles were then isolated for investigation of proteins expression using IHC. An analysis of the preventive exercise (before) and recovery exercise (after) of the EAE was performed. Images of the stained sections were taken using a fluorescent microscope. Quantitative image analysis was performed using ImageJ software package. The obtained data from the mean percentage expression of PSA and NCAM in pre- and post-soleus and plantaris muscles showed that the highest and lowest expression levels of PSA and NCAM belonged to control and swim EAE (SE) groups, respectively. The low expression levels of PSA and NCAM were detected in rat with MS without intervention. In conclusion, the relationship between increasing levels of NCAM and PSA protein expression and voluntary and compulsory activity were detectable both in pre and post-soleus and plantaris. However, voluntary activity resulted in more expression levels of NCAM and PSA than that of compulsory. In conclusion, since it has been suggested that depletion of NCAM is one of the factors associated with or possibly responsible for MS progression, these findings show exercise MS progression may be reduced by increasing expression of exercise-related adhesion molecule such as NCAM and PSA (a glycan modification of the NCAM).

Correlation of blood biomarkers with early-onset seizures after an acute stroke event

IntroductionBlood biomarkers have not been widely studied in stroke-related seizures. In this study, we aimed to describe clinical factors and biomarkers present during acute stroke and to analyze their association with early-onset seizures. MethodsWe retrospectively evaluated a panel of 14 blood biomarkers in 1115 patients with ischemic and hemorrhagic stroke. Biomarkers were normalized and standardized using Z scores. We also recorded stroke and epilepsy-related variables, including stroke severity (National Institute of Health Stroke Scale [NIHSS] scores), type, and causes, time from onset of stroke to occurrence of early seizures, and type of seizure. Adjusted logistic regression models were built to identify clinical variables and biomarkers independently associated with early seizures. ResultsMean ± standard deviation (SD) age was 72.3 ± 13.2 years, and 56.8% of the patients were men. Thirty-eight patients (3.9%) developed early seizures with a median time to onset of 1 day (interquartile range (IQR), 0–4). A higher NIHSS score (odds ratio [OR] = 1.046; 95% confidence interval (CI): 1.001–1.094; p = 0.044) and hemorrhagic stroke (OR = 2.133; 95% CI: 1.010–4.504; p = 0.047) were independently associated with a greater risk of early seizures. Independent blood biomarkers predictive of early seizures were lower levels of tumor necrosis factor receptor 1 (TNF-R1) (<0.013) (p = 0.006; OR = 3.334; 95% CI: 1.414–7.864) and higher levels of neural cell adhesion molecule (NCAM) (>0.326) (p = 0.009; OR = 2.625; 95% CI: 1.271–5.420). The predictive power of the regression model was greater when clinical variables were combined with blood biomarkers (73.5%; 95% CI: 65.1%–81.9%) than when used alone (64%; 95% CI: 55%–72.9%). ConclusionHigher NCAM and lower TNF-R1 levels may help predict the occurrence of early seizures. The combined use of these biomarkers and clinical variables could be useful for identifying patients at risk of seizures.This article is part of the Special Issue “Seizures & Stroke”

Lutein and zeaxanthin isomers may attenuate photo-oxidative retinal damage via modulation of G protein-coupled receptors and growth factors in rats

BackgroundRetina photoreceptor cells are specially adapted for functioning over comprehensive ambient light conditions. Lutein and Zeaxanthin isomers (L/Zi) can protect photoreceptor cells against excessive light degeneration. Efficacy of L/Zi has been assessed on some G protein-coupled receptors (GPCRs), transcription and neurotrophic factors in the retina of rats exposed to incremental intense light emitting diode (LED) illumination conditions. MethodsForty-two male rats (age: 8 weeks) were randomly assigned to six treatment groups, 7 rats each. The rats with a 3x2 factorial design were kept under 3 intense light conditions (12hL/12hD, 16hL/8hD, 24hL/0hD) and received two levels of L/Zi (0 or 100 mg/kg BW) for two months. Increased nuclear factor-kappa B (NF-κB), glial fibrillary acid protein (GFAP), and decreased Rhodopsin (Rho), Rod arrestin (Sag), G Protein Subunit Alpha Transducin1 (Gnat1), neural cell adhesion molecule (NCAM), growth-associated protein-43 (GAP43), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and heme oxygenase 1 (HO-1) were observed in 24 h light intensity adaptation followed by 16 h IL and 8 h D. ResultsL/Zi administration significantly improved antioxidant capacity and retinal Rho, Rod-arrestin (Sag), Gnat1, NCAM, GAP43, BDNF, NGF, IGF1, Nrf2, and HO-1 levels. However, the levels of NF-κB and GFAP levels were decreased by administration of L/Zi. ConclusionsAccording to these results, L/Zi may be assumed as an adjunct therapy to prevent early photoreceptor cell degeneration and neutralize free radicals derived from oxidative stress.

Acute stimulation of vagus nerve modulates brain neurotrophins, and stimulates neuronal plasticity in the hippocampus of adult male rats

The present study was aimed at evaluating whether single intermittent acute cervical vagus nerve stimulation (ACVS), pro-vided at a frequency which exhibits a clinical efficacy, may influence brain neurotrophins and hippocampal plasticity. With this purpose, the brain of adult male rats undergoing ACVS was used to analyze the expression of Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF) in brain areas known to synthetize these growth factors, and the expression the neural cell adhesion molecule (NCAM), the synaptophysin (SYP) and biosynthetic GABA (GAD67) in the hippocampus. The effects of ACVS on NGF and BDNF protein and mRNA in hippocampus, hypothalamus and cortex two hours after stimulation were shown to be dependent on the frequencies of ACVS stimulation. Prolonged (three days post stimulation) modifications of NGF and BDNF were also observed in the hippocampus of ACVS rats. An early enhancement of the plasticity markers NCAM, SYP and GAD67 was also found in ACVS hippocampus. Three days after stimulation, NCAM and GAD67 levels were still higher than controls. Immunohistochemistry confirms the stimulatory effects of ACVS on GABA showing an increase in GAD67-positive cells in the dentate gyrus and CA3 hippocampal areas. This study shows that ACVS affects brain NGF and BDNF synthesis in a frequency-dependent manner. Neurotrophins changes are associated with increased hippocampal plasticity, as demonstrated by the observed molecular and morphological modifications. These findings support the role of brain neurotrophins in the ACVS mechanism of action.

7-Chloro-4-(Phenylselanyl) Quinoline with Memory Enhancer Action in Aging Rats: Modulation of Neuroplasticity, Acetylcholinesterase Activity, and Cholesterol Levels.

This study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) to restore the cognitive impairment caused by aging in male Wistar rats. Moreover, modulation of neuroplasticity markers, acetylcholinesterase (AChE) activity, and cholesterol levels was performed. Aged rats were intragastrically treated with 4-PSQ (5mg/kg) for 7days. Animals were tested in behavioral tasks, and then plasma (to determine cholesterol levels), hippocampus, and cerebral cortex (to determine neural cell adhesion molecule (NCAM) and polysialyltransferase (PST) levels, and AChE activity) were removed. Our findings demonstrated that treatment of aged rats with 4-PSQ restored short-term and long-term memories in the object recognition tests. 4-PSQ treatment did not restore exploratory activity (rearings) but partially restored locomotor activity (crossings) reduced by aging in the open-field test. Moreover, the compound restored the reduction in the NCAM and PST levels, and AChE activity in cerebral structures, as well as the increase in the plasma cholesterol levels, caused by aging in rats. In conclusion, 4-PSQ restored cognitive impairment caused by aging in rats by modulating synaptic plasticity, cholinergic system, and cholesterol levels.

Myelinating Proteins in MS Are Linked to Volumetric Brain MRI Changes.

There is evidence of a relationship between promyelinating proteins and clinical multiple sclerosis (MS) activity during clinical relapse or recovery from clinical relapses. We examined the linkage between promyelinating biomarkers and volumetric changes in MS subjects during serial magnetic resonance imaging (MRI). We enrolled 13 MS subjects with active brain MRI scans not on disease modifying therapies. Subjects underwent baseline MRI, serum, and cerebrospinal fluid (CSF) sampling. Qualitative changes, new/resolving gadolinium, new/enlarging/diminishing T2 and T1 hypointense lesions, were compared to baseline in subsequent MRI scans, and volumetric analysis was calculated. Analysis of biomarkers on serial CSF samples was performed only in subjects with qualitative (and quantitative) changes on MRI. The study was performed at a MS Center of Excellence academic medical center. There was increased CSF neural cell adhesion molecule (N-CAM) during increased qualitative T1 activity. A positive correlation between CSF and serum N-CAM and T1 lesion volume was observed. A negative correlation between serum brain-derived neurotrophic factor (BDNF) and BPH (T1 vol/T2 vol + T1 vol) was observed. Increased N-CAM levels may be related to repair or remyelination following injury to the brain as shown by increased T1 volumes. Our data suggest an early kind of blood signaling that induces release of peripheral BDNF levels.

BEYOND BIOMARKERS: MINING CLINICAL LAB DATA FROM THE EHR FOR USE IN PSYCHIATRIC GENOMIC ANALYSIS

Neural cell adhesion molecule (NCAM) plays an important role in neural plasticity, and its altered function has been implicated in psychiatric disorders. However, previous studies have yielded inconsistent results on cerebrospinal fluid (CSF) NCAM levels in psychiatric disorders. The aim of our study was to examine CSF NCAM levels in patients with schizophrenia, bipolar disorder (BD), and major depressive disorder (MDD), and their possible relationship with clinical variables.The participants comprised 85 patients with schizophrenia, 57 patients with BD, 83 patients with MDD and 111 healthy controls, all matched for age, sex, and Japanese ethnicity. The CSF samples were drawn using a lumbar puncture and NCAM levels were quantified by an enzyme-linked immunosorbent assay.Analysis of covariance controlling for age and sex revealed that CSF NCAM levels were lower in all patients (p = 0.033), and in those with BD (p = 0.039), than in the controls. NCAM levels positively correlated with age in patients with BD (p < 0.01), MDD (p < 0.01), and the controls (p < 0.01). NCAM levels negatively correlated with depressive symptom scores in patients with BD (p = 0.040). In patients with schizophrenia, NCAM levels correlated negatively with negative symptom scores (p = 0.029), and correlated positively with scores for cognitive functions such as category fluency (p = 0.011) and letter fluency (p = 0.023) scores.We showed that CSF NCAM levels were lower in psychiatric patients, particularly bipolar patients than in the controls. Furthermore, we found correlations of NCAM levels with clinical symptoms in patients with BD and in those with schizophrenia, suggesting the involvement of central NCAM in the symptom formation of severe psychiatric disorders.

Allyl isothiocyanate attenuates oxidative stress and inflammation by modulating Nrf2/HO-1 and NF-κB pathways in traumatic brain injury in mice.

Traumatic brain injury (TBI) is the leading cause of mortality and morbidity in young adults and children in the industrialized countries; however, there are presently no FDA approved therapies. TBI results in oxidative stress due to the overproduction of reactive oxygen species and overwhelming of the endogenous antioxidant mechanisms. Recently, it has been reported that antioxidants including phytochemicals have a protective role against oxidative damage and inflammation after TBI. To analyze the effects of a naturally occurring antioxidant molecule, allyl isothiocyanate (AITC), on the nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB) signaling pathways in TBI, a cryogenic injury model was induced in mice. Here, we showed that AITC administered immediately after the injury significantly decreased infarct volume and blood-brain barrier (BBB) permeability. Protein levels of proinflammatory cytokines interleukin-1β (IL1β) and interleukin-6 (IL6), glial fibrillary acidic protein (GFAP) and NF-κB were decreased, while Nrf2, growth-associated protein 43 (GAP43) and neural cell adhesion molecule levels were increased with AITC when compared with vehicle control. Our results demonstrated that the antioxidant molecule AITC, when applied immediately after TBI, provided beneficial effects on inflammatory processes while improving infarct volume and BBB permeability. Increased levels of plasticity markers, as well as an antioxidant gene regulator, Nrf2, by AITC, suggest that future studies are warranted to assess the protective activities of dietary or medicinal AITC in clinical studies.

Plasma levels of soluble NCAM in multiple sclerosis

In multiple sclerosis (MS), several adhesion molecules are involved within the central nervous system in inflammatory and neurodegenerative processes that are associated to progressive disability and increasing brain atrophy. The neural cell adhesion molecule (NCAM) has been suggested to participate in the reparative mechanisms and in the remyelination processes, key issues in MS pathology. We aimed at investigating plasma levels of the seldom investigated soluble (s)NCAM, and as comparison those of intercellular adhesion molecule-1 (sICAM-1) and vascular adhesion molecule-1 (sVCAM-1), and their association with clinical and MRI measures of lesion volumes and of global and regional atrophy. The cross-sectional study was conducted in 85 relapsing-remitting (RR)-MS, 53 progressive (P)-MS patients, and 42 healthy individuals (HI).Correlation of MRI measures with plasma levels of these adhesion molecules were not observed.In the MS and HI groups, sNCAM levels were significantly and positively associated with sVCAM-1 levels. Differently, the correlation between sICAM-1 and sVCAM-1 was observed only in MS patients. sNCAM and sVCAM-1 levels were higher in P-MS compared to HI (P = 0.05 and P = 0.028 respectively). The sVCAM-1 levels differed (P < 0.001) among DMTs groups and HI.The association of sNCAM plasma levels with MS disease, as well as differences in sVCAM-1 levels in patients receiving different DMTs, deserve further investigation.

Cerebrospinal fluid neural cell adhesion molecule levels and their correlation with clinical variables in patients with schizophrenia, bipolar disorder, and major depressive disorder

PurposeNeural cell adhesion molecule (NCAM) plays an important role in neural plasticity, and its altered function has been implicated in psychiatric disorders. However, previous studies have yielded inconsistent results on cerebrospinal fluid (CSF) NCAM levels in psychiatric disorders. The aim of our study was to examine CSF NCAM levels in patients with schizophrenia, bipolar disorder (BD), and major depressive disorder (MDD), and their possible relationship with clinical variables. MethodsThe participants comprised 85 patients with schizophrenia, 57 patients with BD, 83 patients with MDD and 111 healthy controls, all matched for age, sex, and Japanese ethnicity. The CSF samples were drawn using a lumbar puncture and NCAM levels were quantified by an enzyme-linked immunosorbent assay. ResultsAnalysis of covariance controlling for age and sex revealed that CSF NCAM levels were lower in all patients (p=0.033), and in those with BD (p=0.039), than in the controls. NCAM levels positively correlated with age in patients with BD (p<0.01), MDD (p<0.01), and the controls (p<0.01). NCAM levels negatively correlated with depressive symptom scores in patients with BD (p=0.040). In patients with schizophrenia, NCAM levels correlated negatively with negative symptom scores (p=0.029), and correlated positively with scores for cognitive functions such as category fluency (p=0.011) and letter fluency (p=0.023) scores. ConclusionWe showed that CSF NCAM levels were lower in psychiatric patients, particularly bipolar patients than in the controls. Furthermore, we found correlations of NCAM levels with clinical symptoms in patients with BD and in those with schizophrenia, suggesting the involvement of central NCAM in the symptom formation of severe psychiatric disorders.

Targeting NCAM-expressing neuroblastoma with polymeric precision nanomedicine

Neural cell adhesion molecule (NCAM) expression is known to be associated with an aggressive biological behavior, increased metastatic capacity and expression of stem-cell markers in several tumor types. NCAM was also found to be expressed on tumor endothelial cells while forming new capillary-like tubes, but not on normal endothelial cells. An NCAM-targeted polymer-drug conjugate can be used both to target tumors expressing high levels of NCAM as well as the angiogenic vessels and cancer stem cells populations characterized by NCAM expression within tumors. Here, we describe the design, synthesis, physico-chemical characterization and the biological evaluation of an NCAM-targeted conjugate of polyglutamic acid with paclitaxel that was developed and evaluated on neuroblastoma, a high NCAM-expressing tumor. This conjugate inhibited tumor growth to a higher extent compared to the control conjugates and was less toxic than free paclitaxel. The dose of the conjugate could be increased at least twice than the maximum tolerated dose of paclitaxel to achieve better activity without aggravating toxicity. This work presents evidence that NCAM targeting can highly increase the efficacy of nanomedicines in the appropriate tumor models.

Activation of GABAB2 subunits alleviates chronic cerebral hypoperfusion-induced anxiety-like behaviours: A role for BDNF signalling and Kir3 channels

Anxiety is an affective disorder that is commonly observed after irreversible brain damage induced by cerebral ischemia and can delay the physical and cognitive recovery, which affects the quality of life of both the patient and family members. However, anxiety after ischemia has received less attention, and mechanisms underlying anxiety-like behaviours induced by chronic cerebral ischemia are under-investigated. In the present study, the chronic cerebral hypoperfusion model was established by the permanent occlusion of the bilateral common carotid arteries (two-vessel occlusion, 2VO) in rats, and anxiety-related behaviours were evaluated. Results indicated that 2VO induced obvious anxiety-like behaviours; the surface expressions of GABAB2 subunits were down-regulated; Brain derived neurotrophic factor (BDNF), tyrosine kinase B (TrkB) and neural cell adhesion molecule (NCAM) were reduced; Meanwhile, the surface expressions of G protein-activated inwardly rectifying potassium (GIRK, Kir3) channels were up-regulated in hippocampal CA1 in 2VO rats. Baclofen, a GABAB receptor agonist, significantly ameliorated the anxiety-like behaviours. It also improved the down-regulation of GABAB2 surface expressions, restored the levels of BDNF, TrkB and NCAM, and reversed the increased surface expressions of Kir3 in hippocampal CA1 in 2VO rats. However, the effects of baclofen were absent in shRNA-GABAB2 infected 2VO rats. These results suggested that activation of GABAB2 subunits could improve BDNF signalling and reverse Kir3 channel surface expressions in hippocampal CA1, which may alleviate the anxiety-like behaviours in rats with chronic cerebral hypoperfusion.

Exenatide Alters Gene Expression of NCAM, ICAM, and VCAM in the Hippocampus of Type 2 Diabetic Model Mice.

BackgroundGlucagon-like peptide-1 (GLP-1), a potent and selective agonist for the GLP-1 receptor, ameliorates the symptoms of diabetes through stimulation of insulin secretion. Exenatide is a potent and selective agonist for the GLP-1 receptor. Cell adhesion molecules are members of the immunoglobulin superfamily and are involved in synaptic rearrangements in the mature brain.Material/MethodsThe present study demonstrated the effects of exenatide treatment (0.1 μg/kg, subcutaneously, twice daily for 2 weeks) on the gene expression levels of cell adhesion molecules, neural cell adhesion molecule (NCAM), intercellular cell adhesion molecule (ICAM), and vascular cell adhesion molecule (VCAM) in the brain tissue of diabetic BALB/c male mice by real-time quantitative polymerase chain reaction (PCR). Diabetes was induced by streptozotocin/nicotinamide (STZ-NA) injection to male mice.ResultsThe results of this study revealed that hippocampal gene expression of NCAM, ICAM, and VCAM were found to be up-regulated in STZ-NA-induced diabetic mice compared to those of controls. A significant decrease in the gene expression levels of NCAM, ICAM, and VCAM were determined after 2 weeks of exenatide administration.ConclusionsCell adhesion molecules may be involved in the molecular mechanism of diabetes. Exenatide has a strong beneficial action in managing diabetes induced by STZ/NA by altering gene expression of NCAM, ICAM, and VCAM.

Prolyl endopeptidase is involved in the degradation of neural cell adhesion molecules in vitro.

Membrane-associated glycoprotein neural cell adhesion molecule (NCAM) and its polysialylated form (PSA-NCAM) play an important role in brain plasticity by regulating cell-cell interactions. Here, we demonstrate that the cytosolic serine protease prolyl endopeptidase (PREP) is able to regulate NCAM and PSA-NCAM. Using a SH-SY5Y neuroblastoma cell line with stable overexpression of PREP, we found a remarkable loss of PSA-NCAM, reduced levels of NCAM180 and NCAM140 protein species, and a significant increase in the NCAM immunoreactive band migrating at an apparent molecular weight of 120 kDa in PREP-overexpressing cells. Moreover, increased levels of NCAM fragments were found in the concentrated medium derived from PREP-overexpressing cells. PREP overexpression selectively induced an activation of matrix metalloproteinase-9 (MMP-9), which could be involved in the observed degradation of NCAM, as MMP-9 neutralization reduced the levels of NCAM fragments in cell culture medium. We propose that increased PREP levels promote epidermal growth factor receptor (EGFR) signaling, which in turn activates MMP-9. In conclusion, our findings provide evidence for newly-discovered roles for PREP in mechanisms regulating cellular plasticity through NCAM and PSA-NCAM.

Brain structure, cognition and negative symptoms in schizophrenia are associated with serum levels of polysialic acid-modified NCAM.

The neural cell adhesion molecule (NCAM) is a glycoprotein implicated in cell–cell adhesion, neurite outgrowth and synaptic plasticity. Polysialic acid (polySia) is mainly attached to NCAM (polySia-NCAM) and has an essential role in regulating NCAM-dependent developmental processes that require plasticity, that is, cell migration, axon guidance and synapse formation. Post-mortem and genetic evidence suggests that dysregulation of polySia-NCAM is involved in schizophrenia (SZ). We enrolled 45 patients diagnosed with SZ and 45 healthy individuals who were submitted to polySia-NCAM peripheral quantification, cognitive and psychopathological assessment and structural neuroimaging (brain volumes and diffusion tensor imaging). PolySia-NCAM serum levels were increased in SZ patients, independently of antipsychotic treatment, and were associated with negative symptoms, blunted affect and declarative memory impairment. The increased polySia-NCAM levels were associated with decreased volume in the left prefrontal cortex, namely Brodmann area 46, in patients and increased volume in the same brain area of healthy individuals. As this brain region is involved in the pathophysiology of SZ and its associated phenomenology, the data indicate that polySia-NCAM deserves further scrutiny because of its possible role in early neurodevelopmental mechanisms of the disorder.

Short-term effect of adrenalin on S-100b and N-CAM level in the different rat brain areas

The level of adrenalin grows under stress conditions, sense of danger, anxiety, fear, trauma, burns and shock. In high concentrations adrenaline increases the speed of protein catabolism. Working through the circulatory system, adrenaline affects almost all the functions of organs, causing the body mobilization to counter stressful situations. Due to ELISA the astrocytes-specific protein (S-100b) and neural cell adhesion molecule (N-CAM) were studied. S-100b is produced mainly by astrocytes іn the brain and depending on the concentration it causes trophic or toxic effect on the neurons and glial cells.Strong stress and ischemia induce re-distribution of calcium-binding protein S-100b and elevation of its level. Quantitative changes of S-100b under the influence of various factors on the body which lead to the metabolic disorder in the brain are considered today as a sign of brain damage (cortical, ischemic one, etc.). Fluctuations in the concentration of S-100b in the brain are not always accompanied by marked deterioration of the physical condition of animals, but they can also lead to a number of violations of integrative functions of the brain depending on over-production of this protein. Most N-CAM are transmembrane proteins that cross the plasma membraneonce; intracellular domains have different size and it is thought they are involved in binding to cytoskeleton or cell signaling. Violation of N-CAM functions leads to disruption of nerve sprouts. Data obtained in our study showed no serious re-distribution of S-100b and N-CAM level in the different areas of rat brain (cerebral cortex, hippocampus and thalamus) under effect of adrenalin administered to the animals (under skin) in dosage of 0.45–0.60 mg per rat, 1 time per day during 10 days, probably because of the type of injection and/or short time of adrenalin action. Increased dosage of adrenaline 1 hour before decapitation leads to the decrease of level of total protein in membrane fraction extracted from brain tissue without changing the level of S-100b and N-CAM.

Increased prolyl endopeptidase induces alterations in the expression of neural cell adhesion molecule and its polysialylation in SH-SY5Y neuroblastoma cells in vitro

Development of the nervous system and its structural remodelling in the adult relies on molecules mediating the structural plasticity of neurons, e specially those involved in cell adhesion, cytoskeletal dynamics or synapse formation. Neural cell adhesion molecule (NCAM) is a membrane-associated glycoprotein that can be modified by glycosylation with polysialic acid (PSA), attenuating NCAM-mediated cell interactions, thereby promoting structural plasticity [1]. It has been demonstrated that in conditions of neuroinflammation, NCAM can be cleaved extracellularly by metalloproteinases and other proteolytical enzymes. Prolyl endopeptidase (PREP) is a cytosolic serine protease, and alterations in PREP expression and activity have been associated with neuronal death and neuroinflammation [2]. Since the precise mechanisms and possible partners of PREP in neuroinflammation remain unclear, the aim of this study was to determine whether increased secretion and activation of PREP could impair NCAM expression and its polysialylation. SH-SY5H cell line overexpressing (o/e) PREP was used as an in vitro model for increased PREP expression and extracellular release. When measuring expression levels of NCAM and PSA-NCAM we found remarkable loss in PSA-NCAM and disrupted expression patterns of NCAM compared to wild-type cells. As matrix metalloproteinase 9 (MMP-9) has been indicated in processes regulating shedding of PSA-NCAM, MMP-9 expression level was measured. An increase in the level of the active form of MMP-9 was found, which was counteracted by a specific inhibitor of PREP, KYP-2047. As demonstrated, PREP might have an important role in processes involved in NCAM degradation and polysialylation, thereby inducing progression of pathologies associated with altered neuroplasticity.