PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.
Agmatine* ; Biogenic Amines ; Cell Differentiation ; Cell Proliferation ; Central Nervous System ; MicroRNAs* ; Neural Stem Cells* ; Neurogenesis ; Neurons

PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.
Agmatine* ; Biogenic Amines ; Cell Differentiation ; Cell Proliferation ; Central Nervous System ; MicroRNAs* ; Neural Stem Cells* ; Neurogenesis ; Neurons

Agmatine, a widely distributed molecule in mammalian tissues, shows neuroprotective effects in brain ischemia. We describe the neuroprotective effects of agmatine in the mouse MCAO model and the quantitative change of agmatine in ischemic injury. Brain ischemic injured mice were injected with agmatine (100 mg/kg of mouse, IP). Agmatine significantly reduced the infarct area after MCAO. Despite the similar patterns of agmatine change observed in control or agmatine injected animals, the agmatine levels of the penumbra were significantly higher than those of the striatum and the cerebral cortex during the early period (<1 hour after 2 hours of MCA occlusion). This suggests that the early period, during which agmatine levels increase in the brain, is the crucial period in terms of neuroprotective effect during ischemia.
Agmatine* ; Animals ; Brain Ischemia ; Brain* ; Cerebral Cortex ; Chromatography, High Pressure Liquid* ; Ischemia ; Mice ; Neuroprotective Agents ; Reperfusion

This study was conducted to investigate whether agmatine (AGM) provides protection against oxidative stress induced by treatment with chlorpromazine (CPZ) in Wistar rats. In addition, the role of reactive oxygen species and efficiency of antioxidant protection in the brain homogenates of forebrain cortexes prepared 48 h after treatment were investigated. Chlorpromazine was applied intraperitoneally (i.p.) in single dose of 38.7 mg/kg body weight (BW) The second group was treated with both CPZ and AGM (75 mg/kg BW). The control group was treated with 0.9% saline solution in the same manner. All tested compounds were administered i.p. in a single dose. Rats were sacrificed by decapitation 48 h after treatment Treatment with AGM significantly attenuated the oxidative stress parameters and restored antioxidant capacity in the forebrain cortex. The data indicated that i.p. administered AGM exerted antioxidant action in CPZ-treated animals. Moreover, reactive astrocytes and microglia may contribute to secondary nerve-cell damage and participate in the balance of destructive vs. protective actions involved in the pathogenesis after poisoning.
Agmatine/*pharmacology ; Animals ; Antioxidants/pharmacology ; Chlorpromazine/toxicity ; Oxidative Stress/*drug effects ; Prosencephalon/*drug effects ; Rats ; Rats, Wistar

Agmatine ; administration & dosage ; pharmacology ; Analgesia ; methods ; Animals ; Injections, Spinal ; Male ; Morphine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; drug effects

BACKGROUND: Previous studies suggest that systemic administration of agmatine, endogenous ligand for imidazoline receptors has anti-hypernociceptive effects in experimental animal. However the peripheral effects of agmatine on inflammatory pain have not yet been elucidated. Here we examined the effects of intra-articular injection of agmatine in the induction and maintenance phase of arthritic pain. In addition, we sought to determine the potential contribution of imidazoline and alpha(2)-adrenergic receptors to the antinociceptive effects using clonidine which is mixed alpha(2)-adrenoceptor and imidazoline receptor agonist. METHODS: To induce arthritis in rats, 2% lambda-carrageenan (50microliter, in saline) was injected into the joint of the right hind limb under enflurane anesthesia. Either agmatine (10, 50, 100microgram/40microliter) or clonidine (10, 50, 100microgram/40microliter) was injected into the knee joint cavity immediately before or 4 hr after carrageenan injection. Weight load tests were performed to measure pain-related behavior in freely walking rats. RESULTS: The intraarticular injection of agmatine into the knee joint had no effects in the both phase of induction and maintenance of arthritic pain at any dose tested. However, injection of clonidine reversed arthritic pain, when injected 4 h after carrageenan injection. CONCLUSIONS: In rats, agmatine has no peripheral effect on inflammatory pain and imidazoline receptors in the periphery may not contribute to the anti-inflammatory pain.
Agmatine ; Anesthesia ; Animals ; Arthritis ; Carrageenan ; Clonidine ; Enflurane ; Extremities ; Imidazoline Receptors ; Inflammation ; Injections, Intra-Articular ; Joints ; Knee ; Knee Joint ; Rats ; Walking

Differentiation of neural progenitor cells (NPCs) is important for protecting neural cells and brain tissue during inflammation. Interleukin-1 beta (IL-1beta) is the most common pro- inflammatory cytokine in brain inflammation, and increased IL-1beta levels can decrease the proliferation of NPCs. We aimed to investigate whether agmatine (Agm), a primary polyamine that protects neural cells, could trigger differentiation of NPCs by activating IL-1beta in vitro. The cortex of ICR mouse embryos (E14) was dissociated to culture NPCs. NPCs were stimulated by lipopolysaccharide (LPS). After 6 days, protein expression of stem cell markers and differentiation signal factors was confirmed by using western blot analysis. Also, immunocytochemistry was used to confirm the cell fate. Agm treatment activated NPC differentiation significantly more than in the control group, which was evident by the increased expression of a neuronal marker, MAP2, in the LPS-induced, Agm-treated group. Differentiation of LPS-induced, Agm-treated NPCs was regulated by the MAPK pathway and is thought to be related to IL-1beta activation and decreased expression of TLX, a transcription factor that regulates NPC differentiation. Our results reveal that Agm can promote NPC differentiation to neural stem cells by modulating IL-1beta expression under inflammatory condition, and they suggest that Agm may be a novel therapeutic strategy for neuroinflammatory diseases.
Agmatine* ; Animals ; Blotting, Western ; Brain ; Embryonic Structures ; Encephalitis ; Immunohistochemistry ; Inflammation ; Interleukin-1beta ; Mice ; Mice, Inbred ICR ; Neural Stem Cells ; Neurons* ; Stem Cells ; Transcription Factors

BACKGROUND: The intrathecal (IT) GABAA receptor antagonist, bicuculline (BIC), results in tactile allodynia (TA) through disinhibition in the spinal cord. Such disinhibition is considered to be an important mechanism for neuropathic pain. Agmatine, an endogenous polyamine, has a neuro-protective effect in the central nervous system. We investigated the analgesic effects and mechanisms of agmatine action on BIC-induced TA. METHODS: Male Sprague-Dawley rats, weighting 250-300 g, were subjected to implantations of PE-10 into the lumbar subarachnoid space for IT drug injection. Five days after surgery, either 10 microliter of normal saline (NS) or agmatine (30 microgram or 10 microgram) in 10 microliter NS were injected 10 min prior to BIC (10 microgram) or NMDA (5 microgram). We assessed the degree of TA (graded 0: no response, 1: mild response, 2: moderate response, 3: strong response) every 5 min for 30 min. Areas under curves and degree of TA were expressed as mean +/- SEM. Results were analyzed using one-way ANOVA followed by a Tukey test for multiple comparisons. P < 0.05 was considered significant. RESULTS: IT BIC-induced strong TA reached its peak and plateaued between 10 to 15 min. IT NS-NMDA induced mild transient TA for up to 15 min. Preemptive IT AG attenuated IT BIC-induced TA dose dependently and preemptive IT AG10 completely abolished the IT NMDA-induced TA. CONCLUSIONS: Preemptive IT AG attenuated the IT BIC-induced TA through inhibitory actions on postsynaptic NMDA receptor activation. AG might be a viable therapeutic option in the treatment of neuropathic pain.
Agmatine ; Bicuculline ; Central Nervous System ; Humans ; Hyperalgesia ; Male ; N-Methylaspartate ; Neuralgia ; Nitrogen Mustard Compounds ; Rats, Sprague-Dawley ; Spinal Cord ; Subarachnoid Space

Agmatine is a decarboxylated arginine by arginine decarboxylase. Agmatine is known to be a neuroprotective agent. It has been reported that agmatine works as a NMDA receptor blocker or a competitive nitric oxide synthase inhibitor in CNS injuries. In spinal cord injury, agmatine showed reduction of neuropathic pain, improvement of locomotor function, and neuroprotection. Macrophage is a key cellular component in neuroinflammation, a major cause of impairment after spinal cord injury. Macrophage has subtypes, M1 and M2 macrophages. M1 macrophage induces a pro-inflammatory response, but M2 inspires an anti-inflammatory response. In this study, it was clarified whether the neuroprotective effect of agmatine is related with the modulation of macrophage subdivision after spinal cord injury. Spinal cord injury was induced in rats with contusion using MASCIS. Animals received agmatine (100 mg/kg, IP) daily for 6 days beginning the day after spinal cord injury. The proportion of M1 and M2 macrophages are confirmed with immunohistochemistry and FACS. CD206+ & ED1+ cells were counted as M2 macrophages. The systemic treatment of agmatine increased M2 macrophages caudal side to epicenter 1 week after spinal cord injury in immunohistochemistry. M2 macrophage related markers, Arginase-1 and CD206 mRNA, were increased in the agmatine treatment group and M2 macrophage expressing and stimulated cytokine, IL-10 mRNA, also was significantly overexpressed by agmatine injection. Among BMPs, BMP2/4/7, agmatine significantly increased only the expression of BMP2 known to reduce M1 macrophage under inflammatory status. These results suggest that agmatine reduces impairment after spinal cord injury through modulating the macrophage phenotype.
Agmatine* ; Animals ; Arginine ; Contusions ; Immunohistochemistry ; Interleukin-10 ; Macrophages* ; N-Methylaspartate ; Neuralgia ; Neuroprotection ; Neuroprotective Agents ; Nitric Oxide Synthase ; Phenotype* ; Rats* ; RNA, Messenger ; Spinal Cord Injuries* ; Spinal Cord*

This study is to explore a behavioral and pathological model for depression in mice, and evaluate the anti-depressant-like effect of agmatine. Neonatal Kunming mice were treated with fluoxetine (10 mg x kg(-1), ip, qd) for 17 d (between day 4 and 21 after birth), and then the mice were normally housed till being adult (about 10 weeks after birth). The behaviors of the mice were measured by using open-field test, novelty suppressed feeding test and tail-suspension test. Hippocampal adenylate cyclase (AC) activity was measured by radioimmunoassay. Neonatal exposure to fluoxetine induced a "depression-like" behaviors in the adult mice, shown as the decreased locomotor activity, increased feeding latency and immobility time in the open-field test, novelty suppressed feeding test, and tail-suspension test, respectively. Chronic agmatine treatment (10 mg x kg(-1), ig, bid) for 3 weeks significantly increased the locomotor activity, and decreased the feeding latency in the neonatal fluoxetine exposed mice. Furthermore, single treatment with agmatine (40 mg x kg(-1), ig) also decreased the immobility time in the tail-suspension test, and increased the hippocampal AC activity in the mice. These results indicate that neonatal exposure to fluoxetine induces depressive-like behaviors in the adult mice. Agmatine reverses these behaviors, which may be closely related to the enhancement of the hippocampal AC activity.
Agmatine ; pharmacology ; Animals ; Antidepressive Agents ; pharmacology ; Depressive Disorder ; chemically induced ; Disease Models, Animal ; Female ; Fluoxetine ; administration & dosage ; adverse effects ; Male ; Mice ; Mice, Inbred Strains