Parkinson's disease is the second most common neurodegenerative disorder characterized by the progressive degeneration of dopaminergic neurons and a biochemical reduction of striatal dopamine levels. Despite the lack of fully understanding of the etiology of Parkinson's disease, accumulating evidences suggest that Parkinson's disease may be caused by the insufficient support of neurotrophic factors, and by microglial activation, resident immune cells in the brain. Naringin, a major flavonone glycoside in grapefruits and citrus fruits, is considered as a protective agent against neurodegenerative diseases because it can induce not only anti-oxidant effects but also neuroprotective effects by the activation of anti-apoptotic pathways and the induction of neurotrophic factors such as brain-derived neurotrophic factor and vascular endothelial growth factor. We have recently reported that naringin has neuroprotective effects in a neurotoxin model of Parkinson's disease. Our observations show that intraperitoneal injection of naringin induces increases in glial cell line-derived neurotrophic factor expression and mammalian target of rapamycin complex 1 activity in dopaminergic neurons of rat brains with anti-inflammatory effects. Moreover, the production of glial cell line-derived neurotrophic factor by naringin treatment contributes to the protection of the nigrostriatal dopaminergic projection in a neurotoxin model of Parkinson's disease. Although the effects of naringin on the nigrostriatal dopaminergic system in human brains are largely unknown, these results suggest that naringin may be a beneficial natural product for the prevention of dopaminergic degeneration in the adult brain.
Adult ; Animals ; Antioxidants ; Brain ; Brain-Derived Neurotrophic Factor ; Citrus ; Citrus paradisi ; Dopamine ; Dopaminergic Neurons ; Glial Cell Line-Derived Neurotrophic Factor ; Humans ; Injections, Intraperitoneal ; Nerve Growth Factors ; Neurodegenerative Diseases ; Neuroprotective Agents ; Parkinson Disease ; Rats ; Sirolimus ; Vascular Endothelial Growth Factor A

Hypothermia is considered a useful intervention for limiting pathophysiological changes after brain injury. Local hypothermia is a relatively safe and convenient intervention that circumvents many of the complications associated with systemic hypothermia. However, successful hypothermia treatment requires careful consideration of several factors including its practicality, feasibility, and associated risks. Here, we review the protective effects-and the cellular mechanisms that underlie them-of delayed and prolonged local hypothermia in rodent and canine brain injury models. The data show that the protective effects of therapeutic hypothermia, which mainly result from the modulation of inflammatory glial dynamics, are limited. We argue that decompressive craniectomy can be used to overcome the limitations of local brain hypothermia without causing histological abnormalities or other detrimental effects to the cooled area. Therefore, delayed and prolonged local brain hypothermia at the site of craniectomy is a promising intervention that may prove effective in the clinical setting.
Astrocytes ; Brain Injuries ; Brain* ; Decompressive Craniectomy* ; Hypothermia* ; Microglia ; Rodentia ; Stroke

We correct a typo in the title.

It has been suggested that the hippocampus and the prefrontal cortex (PFC) play key roles in representing contextual memory and utilizing contextual information for flexible response selection. During response selection, a correct response should be facilitated and an incorrect response should be inhibited flexibly in association with a cueing stimulus. However, it is poorly understood how the hippocampal and PFC networks behave during such flexible control of facilitation and inhibition of behavioral responses. To find neural correlates of context-cued flexible response selection, the current study employed an object-place paired-associate (OPPA) task in which object A is only rewarded in place 1 and object B is associated with reward in place 2 while recording single units simultaneously from the hippocampus and PFC. During the task, response inhibition in front of a contextually wrong object is required for successful performance and such inhibitory responses were observed before the rat learned the task. A significant proportion of neurons that fired differentially depending on the existence of inhibitory behavior in the PFC was observed during the pre-learning stage. By contrast, the proportion of such neurons in the hippocampus was significantly greater than chance during post-learning stage. The results suggest that the development of inhibitory behavior is a critical behavioral marker that foretells an upcoming acquisition of the task and the hippocampus and PFC are involved in learning contextual response selection by learning how to control the inhibition of behavior as learning progresses.
Animals ; Cues ; Electrophysiology ; Fires ; Hippocampus* ; Learning ; Memory ; Neurons* ; Prefrontal Cortex* ; Rats ; Reward

Calbindin-D28K has been implicated in the regulation of neuronal cell death. Previously, we demonstrated that calbindin-D28K prevents staurosporine (STS)-induced caspase activation and subsequent apoptosis in a neuronal cell line. However, the role of calbindin-D28K in STS-induced activation of calpain and necrotic cell death was not identified. Staurosporine induced the elevation of intracellular calcium after 1 hr of treatment. Overexpression of calbindin-D28K and presence of a calcium chelator, BAPTA, prevented the increase of calcium in STS-treated cells. Cleavage of Bax by calpain was prevented by the overexpressed calbindin-D28K. Permeabilization of the plasma membrane, a factor in necrosis, as well as apoptotic change of the nucleolus induced by STS, was prevented by calbindin-D28K. Thus, our study suggests that calbindin-D28K may exert its protective functions by preventing calpain activation in necrotic cell death, in addition to its effect on the caspase-apoptosis pathway.
Apoptosis ; Calbindin 1* ; Calcium ; Calpain ; Cell Death ; Cell Line ; Cell Membrane ; Membranes* ; Necrosis ; Neurons ; Staurosporine

Compared with biochemical information available about the diseases in the central nervous system, that for peripheral neuropathy is quite limited primarily due to the difficulties in obtaining samples. Characterization of the core pathology is a prerequisite to the development of personalized medicine for genetically heterogeneous diseases, such as hereditary motor and sensory neuropathy (HMSN). Here, we first documented the transcriptome profile of distal sural nerve obtained from HMSN patients. RNA-seq analysis revealed that over 12,000 genes are expressed in distal sural nerve. Among them 4,000 transcripts are novel and 10 fusion genes per sample were observed. Comparing dataset from whole exome sequencing revealed that over 1,500 transcriptional base modifications occur during transcription. These data implicate that dynamic alterations are generated when genetic information are transitioned in distal sural nerve. Although, we could not find significant alterations associated with HMSN, these data might provide crucial information about the pathophysiology of HMSN. Therefore, next step in the development of therapeutic strategy for HMSN might be unveiling biochemical and biophysical abnormalities derived from those potent variation.
Central Nervous System ; Dataset ; Exome ; Gene Expression Profiling* ; Hereditary Sensory and Motor Neuropathy ; Humans ; Pathology ; Peripheral Nervous System Diseases ; Sural Nerve* ; Transcriptome ; Precision Medicine

Isoliquiritigenin (ILTG) is a chalcone compound and shows various pharmacological properties, including antioxidant and anti-inflammatory activities. In recent study, we have reported a novel role of ILTG in sleep through a positive allosteric modulation of gamma-aminobutyric acid type A (GABA(A))-benzodiazepine (BZD) receptors. However, the effect of ILTG in GABA(A)R-mediated synaptic response in brain has not been tested yet. Here we report that ILTG significantly prolonged the decay of spontaneous inhibitory postsynaptic currents (sIPSCs) mediated by GABA(A)R in mouse hippocampal CA1 pyramidal neurons without affecting amplitude and frequency of sIPSCs. This enhancement was fully inhibited by flumazenil (FLU), a specific GABA(A)-BZD receptor antagonist. These results suggest a potential role of ILTG as a modulator of GABAergic synaptic transmission.
Animals ; Brain ; Chalcone* ; Flumazenil ; gamma-Aminobutyric Acid ; Inhibitory Postsynaptic Potentials ; Mice ; Neurons ; Synaptic Transmission

Lipocalin-2 (LCN2) is a key mediator of various cellular processes. Recent studies have indicated that LCN2 also plays an important role in central nervous system (CNS) injuries and neurological diseases, such as spinal cord injury, stroke, experimental autoimmune encephalomyelitis, and neurodegenerative diseases. Here, we investigated the role of LCN2 in a rodent model of lipopolysaccharide (LPS)-induced neuroinflammation. At 24 hours after intraperitoneal injection of LPS, LCN2 expression was strongly induced in the brain; LCN2 was mainly expressed in endothelial cells, astrocytes, and microglia. Next, we used LCN2-deficient mice to further investigate the role of LCN2 in neuroinflammation. LCN2 deficiency attenuated LPS-induced glial activation in the brain. In a mechanistic study employing glia/neuron co-cultures, LCN2 deficiency reduced glial neurotoxicity. Our results indicate that LCN2 plays a central role in the neuroinflammatory responses following LPS administration, and that LCN2 might contribute to the uncontrolled neurotoxic glial activation under excessive and chronic inflammatory conditions.
Animals ; Astrocytes ; Brain ; Central Nervous System ; Coculture Techniques ; Encephalomyelitis, Autoimmune, Experimental ; Endothelial Cells ; Injections, Intraperitoneal ; Mice* ; Microglia ; Neurodegenerative Diseases ; Neurons ; Rodentia ; Spinal Cord Injuries ; Stroke

Previously, we reported that DJ-1, encoded by a Parkinson's disease (PD)-associated gene, inhibits expression of proinflammatory mediators in interferon-gamma (IFN-gamma)-treated astrocytes and microglia through inhibition of STAT1 activation. Here, using microglia and astrocytes cultured from wild-type (WT) and DJ-1-knockout (KO) mouse brains, we examined how DJ-1 regulates suppressor of cytokine signaling 1 (SOCS1), a negative feedback regulator of STAT1 (signal transducer and activator of transcription) that is also induced by STAT1. We found that IFN-gamma significantly increased SOCS1 mRNA expression in WT microglia and astrocytes, but not in KO cells, although STAT1 was highly activated in these latter cells. We further found that SOCS mRNA stability was decreased in DJ-1-KO cells, an effect that appeared to be mediated by the microRNA, miR-155. IFN-gamma increased the levels of miR-155 in DJ-1-KO cells but not in WT cells. In addition, an miR-155 inhibitor rescued SOCS1 expression and decreased STAT1 activation in DJ-1-KO cells. Taken together, these results suggest that DJ-1 efficiently regulates inflammation by maintaining SOCS1 expression through regulation of miR-155 levels, even under conditions in which STAT1 activation is decreased.
Animals ; Astrocytes* ; Brain ; Inflammation ; Interferon-gamma ; Mice ; Microglia* ; MicroRNAs ; Parkinson Disease ; RNA Stability ; RNA, Messenger ; Transducers

Toll-like receptors (TLRs) belong to a class of pattern recognition receptors that play an important role in host defense against pathogens. TLRs on innate immune cells recognize a wide variety of pathogen-associated molecular patterns (PAMPs) and trigger innate immune responses. Later, it was revealed that the same receptors are also utilized to detect tissue damage to trigger inflammatory responses in the context of non-infectious inflammation. In the nervous system, different members of the TLR family are expressed on glial cells including astrocytes, microglia, oligodendrocytes, and Schwann cells, implicating their putative role in innate/inflammatory responses in the nervous system. In this regard, we have investigated the function of TLRs in neuroinflammation. We discovered that a specific member of the TLR family, namely TLR2, functions as a master sentry receptor to detect neuronal cell death and tissue damage in many different neurological conditions including nerve transection injury, intracerebral hemorrhage, traumatic brain injury, and hippocampal excitotoxicity. In this review, we have summarized our research for the last decade on the role of TLR2 in neuroinflammation in the above neurological disorders. Our data suggest that TLR2 can be an efficient target to regulate unwanted inflammatory response in these neurological conditions.
Astrocytes ; Brain Injuries ; Cell Death ; Cerebral Hemorrhage ; Cerebral Hemorrhage, Traumatic ; Humans ; Immunity, Innate ; Inflammation ; Microglia ; Nervous System ; Nervous System Diseases ; Neuralgia ; Neurodegenerative Diseases* ; Neuroglia ; Neurons ; Oligodendroglia ; Receptors, Pattern Recognition ; Schwann Cells ; Stroke ; Toll-Like Receptors