Koei Shinzawa

Learn More
Calcium-independent group VIA phospholipase A2 (iPLA2beta) is considered to play a role in signal transduction and maintenance of homeostasis or remodeling of membrane phospholipids. A role of iPLA2beta has been suggested in various physiological and pathological processes, including immunity, chemotaxis, and cell death, but the details remain unclear.(More)
Infantile neuroaxonal dystrophy (INAD) is a fatal neurodegenerative disease characterized by the widespread presence of axonal swellings (spheroids) in the CNS and PNS and is caused by gene abnormality in PLA2G6 [calcium-independent phospholipase A(2)β (iPLA(2)β)], which is essential for remodeling of membrane phospholipids. To clarify the pathomechanism of(More)
Apoptosis is defined on the basis of morphological changes like nuclear fragmentation and chromatin condensation, which are dependent on caspases. Many forms of caspase-independent cell death have been reported, but the mechanisms are still poorly understood. We found that hypoxic cell death was independent of caspases and was associated with significant(More)
Extensive studies have unveiled the intracellular molecular signaling pathways of cell death. To better understand cell death in tissues, it is important to investigate the influence of neighboring cells on the response to death stimuli. By time-lapse microscopy, we found that cells in couplets (two hepatocytes attached to each other) died independently(More)
Mutations in PLA2G6 have been proposed to be the cause of neurodegeneration with brain iron accumulation type 2. The present study aimed to clarify the mechanism underlying brain iron accumulation during the deficiency of calcium-independent phospholipase A2 beta (iPLA2β), which is encoded by the PLA2G6 gene. Perl's staining with diaminobenzidine(More)
Olfactory stem cells are generated from olfactory mucosa. Various culture conditions generate olfactory stem cells that differ according to species and developmental stage and have different progenitor or stem cell characteristics. Olfactory spheres (OSs) are clusters of progenitor or stem cells generated from olfactory mucosa in suspension culture. In this(More)
Spinal cord injury is often followed by disuse muscle atrophy. The effect of disuse muscle atrophy on motor neurons below the level of spinal cord lesions is not fully understood. We produced spinal contusions in the mid-thoracic segment (Th7/8) of rats. To promote disuse muscle atrophy, their hind limbs were immobilized. Alpha-motor neurons in L4/5 at 3(More)
To clarify the role of α-synuclein (αSyn) in neuronal membrane remodeling, we analyzed the expression of αSyn in neurons with a dysfunction of PLA2G6, which is indispensable for membrane remodeling. αSyn/phosphorylated-αSyn (PαSyn) distribution and neurodegeneration were quantitatively estimated in PLA2G6-knockout (KO) mice, which demonstrate marked(More)
OBJECTIVE Diffuse astrocytomas (DAs) have a high recurrence rate due to diffuse infiltration into the brain and spinal cord. Micro RNAs (miRNAs) are small noncoding RNAs that regulate gene expression by binding to complementary sequences of target messenger RNA (mRNA). It has been reported that miRNA-22 (miR-22) is involved in the invasion of some cancer(More)
Calcium-independent phospholipase A2β (iPLA2β, PLA2G6) is essential for the remodeling of membrane glycerophospholipids. Mutations in this gene are responsible for autosomal recessive, young onset, L-dopa-responsive parkinsonism (PARK14), suggesting a neurodegenerative condition in the nigrostriatal dopaminergic system in patients with PLA2G6 mutations. We(More)