Publications by authors named "IKAWA M"

Background: Reproductive research is quintessential in understanding not only the cause of infertility, but also for creating family planning tools. The knockout (KO) system approach is conducive to discovering genes that are essential for fertility in mice. However, in vivo research has been limited due to its high cost and length of time needed to establish KO mice.

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Sperm entry in mammalian oocytes triggers intracellular Ca oscillations that initiate resumption of the meiotic cell cycle and subsequent activations. Here, we show that phospholipase C zeta 1 (PLCζ1) is the long-sought sperm-borne oocyte activation factor (SOAF). Plcz1 gene knockout (KO) mouse spermatozoa fail to induce Ca changes in intracytoplasmic sperm injection (ICSI).

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Mammalian fertilization is comprised of many steps including sperm survival in the uterus, sperm migration in the female reproductive tract, physiological and morphological changes to the spermatozoa, and sperm-egg interaction in the oviduct. In vitro studies have revealed essential factors for these fertilization steps for over half a century. However, the molecular mechanism of fertilization has recently been revised by the emergence of genetically modified animals.

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Brain-derived neurotrophic factor (BDNF) has been considered an essential mediator responsible for the beneficial effects of physical activity in preventing cognitive impairment. This study aimed at examining the effects of a single bout of neuromuscular electrical stimulation (NMES) on levels of BDNF in the plasma and on cognitive performance in healthy adult men. Thirteen healthy adult men participated in three experimental sessions.

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Cytochrome P450, family 3, subfamily A (CYP3A) enzymes metabolize approximately 50% of commercially available drugs. Recently, we developed fully humanized transchromosomic (Tc) CYP3A mice with the CYP3A cluster including CYP3A4, CYP3A5, CYP3A7, and CYP3A43. Our humanized CYP3A mice have the CYP3A5*3 (g.

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A recent genetic analysis of infertile globozoospermic patients identified causative mutations in three genes: a protein interacting with C kinase 1 (), dpy 19-like 2 (), and spermatogenesis associated 16 (). Although mouse models have clarified the physiological functions of and during spermatogenesis, remains to be determined. Globozoospermic patients carried a homozygous point mutation in at 848G→A/R283Q.

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Translocator protein (TSPO) is a biomarker for detecting neuroinflammation by PET. C-(R)-PK11195 has been used to image TSPO since the 1980s. Here, we compared the utility of four C-labeled ligands-(R)-PK11195, PBR28, DPA-713, and ER176-to quantify TSPO in healthy humans.

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Background: Although spermatozoa with normal morphology are assumed to have uniform fertilization ability, recent data show that even normal spermatozoa have considerable variation in their head shape which is associated with differences in fertilization ability. Appropriate quantitative indicators for good sperm morphology, however, remain unidentified.

Methods: Therefore, in an effort to identify such an indicator, we compared the nuclear contour of normal mouse spermatozoa by quantitative multivariate analysis using elliptic Fourier descriptors combined with principal component analysis.

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The placenta is an essential organ for embryo development in the uterus of eutherian mammals. Large contributions in unveiling molecular mechanisms and physiological functions underlying placental formation were made by analyzing mutant and transgenic animals. However, it had been difficult to elucidate whether the placental defects observed in such animals originate from the placenta itself or from the fetus, as both placental and fetal genomes are modified.

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Acrosin, the trypsin-like serine protease in the sperm acrosome, was long viewed as a key enzyme required for zona pellucida penetration to fertilize eggs. However, gene disruption experiments in mice surprisingly showed that acrosin-disrupted males were fertile. Thus, the acrosin was considered to be not an essential enzyme for fertilization in mice.

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Background: This study sought to precisely evaluate striatal oxidative stress and its relationship with the disease severity in Parkinson's disease (PD) using double brain imaging, 62Cu-diacetyl-bis (N4-methylthiosemicarbazone) (62Cu-ATSM) PET and 123I-FP-CIT SPECT.

Methods: Nine PD patients were studied with brain 62Cu-ATSM PET for oxidative stress and 123I-FP-CIT SPECT for the density of striatal dopamine transporter. Standardized uptake values (SUVs) were obtained from the delayed phase of dynamic 62Cu-ATSM PET, and striatum-to-cerebellum SUV ratio (SUVR) was calculated.

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Article Synopsis
  • Skeletal muscle consists of diverse myofiber types, primarily classified as slow-twitch and fast-twitch, influenced by various genes, including Vgll2.
  • Vgll2 null mice showed an increase in fast-twitch fibers and a decrease in slow-twitch MyHC gene expression, leading to difficulties in exercise.
  • The study found a connection between Vgll2 and TEAD transcription factors, suggesting Vgll2 plays a crucial role in regulating slow muscle fiber development.
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Complete removal of hepatitis B virus (HBV) DNA from nuclei is difficult by the current therapies. Recent reports have shown that a novel genome-editing tool using Cas9 with a single-guide RNA (sgRNA) system can cleave the HBV genome in vitro and in vivo. However, induction of a double-strand break (DSB) on the targeted genome by Cas9 risks undesirable off-target cleavage on the host genome.

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In mammalian cells, genome editing with the single guide RNA (sgRNA)/Cas9 complex allows for high targeting efficiency within a relatively short time frame with the added benefits of being low cost and easy to design. sgRNA/Cas9-mediated editing in mouse zygotes has accelerated the analysis of gene functions and the generation of mouse models of human diseases. Despite the benefits, this method still suffers from several problems, such as mosaicism in the founder generation which complicates genotyping and phenotypical analyses, and the low efficiency of more complicated genome editing.

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Article Synopsis
  • Flagella and cilia are essential for cell movement and environmental sensing, made up of a specialized structure called the axoneme.
  • Mutations or improper assembly of axonemal components can lead to ciliopathies, which are diseases that severely impact various organ functions and development in humans.
  • TCTE1 is a crucial protein for sperm motility, and its absence causes male sterility due to impaired flagellum function, even though the axoneme structure appears normal.
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Inappropriate IL-17 responses are implicated in chronic tissue inflammation. IL-23 contributes to -specific IL-17 production, but the molecular mechanisms underlying regulation of the IL-23-IL-17 axis during infection are poorly understood. Here, we demonstrate a novel function of BATF2 as a negative regulator of in innate immune cells.

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During mammalian fertilization, egg Ca 2+ oscillations are known to play pivotal roles in triggering downstream events such as resumption of the cell cycle and the establishment of blocks to polyspermy. However, viable offspring have not been obtained after monitoring Ca 2+ oscillations, and their spatiotemporal links to subsequent events are still to be examined. Therefore, the development of imaging methods to avoid phototoxic damage while labeling these events is required.

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Several types of autoantibodies have been reported in autoimmune limbic encephalitis (LE), such as antibodies against the voltage-gated potassium channel (VGKC) complex including leucine-rich glioma inactivated 1 (LGI1). We recently reported a patient with autoimmune LE and serum anti-NH2-terminal of α-enolase (NAE) antibodies, a specific diagnostic marker for Hashimoto encephalopathy (HE), who was diagnosed with HE based on the presence of antithyroid antibodies and responsiveness to immunotherapy. This case suggests that LE patients with antibodies to both the thyroid and NAE could be diagnosed with HE and respond to immunotherapy.

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In mammalian fertilization, a small spermatozoon interacts with an egg that is a few thousand times larger in volume. In spite of the big difference in size and mass, when spermatozoa are bound to eggs, they begin rotating the eggs in in vitro observation. This was dubbed the 'fertilization dance'.

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A 49-year-old woman presented with progressive muscle weakness of the limbs and dysphagia. Her past and family medical history were unremarkable and she did not take statins or any other medications. Laboratory tests showed that serum levels of creatine kinase were elevated (13,565 IU/l) and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies were detected in the serum.

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Animals choose reproductive partners based on their sexual preferences which are established at a certain time point before, during, or after sexual maturation. The preferences are often divergent within a species, which suppresses gene flow between populations and may promote speciation. There are two strains of medaka () that differ by a single transgene and mate assortatively depending on skin color.

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Jmjd3 and Utx are demethylases specific for lysine 27 of histone H3. Previous reports indicate that Jmjd3 is essential for differentiation of various cell types, such as macrophages and epidermal cells in mice, whereas Utx is involved in cancer and developmental diseases in humans and mice, as well as regulation in zebrafish and nematodes. Here, we report that Jmjd3, but not Utx, is involved in axial skeletal formation in mice.

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Preeclampsia is a severe complication of pregnancy. Antiangiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin are secreted in excess from the placenta, causing hypertension, endothelial dysfunction, and multiorgan injury. Oxidative stress and vascular inflammation exacerbate the endothelial injury.

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Article Synopsis
  • Cellular differentiation involves changes in chromatin that create unique epigenomic features for different cell types.
  • In mouse testes, the histone H3 variant H3t is crucial for the early stages of sperm development; without it, sperm cells can't mature properly, leading to azoospermia (lack of sperm).
  • H3t replaces standard H3 proteins in developing spermatogonia, resulting in more flexible nucleosomes that allow germ cells to successfully progress through meiosis.
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Article Synopsis
  • - The study investigates the role of branched-chain amino acids (BCAAs) in protein metabolism by creating mice with lower BCAA levels to observe effects on muscle function.
  • - Although these mice maintained health on a protein-rich diet, they showed increased mTORC1 sensitivity when BCAAs were ingested, indicating a response to nutrient availability.
  • - When placed on a low-protein diet, these mice experienced significant loss of myofibrillar proteins and reduced mTORC1 activity, highlighting that BCAAs are critical in maintaining muscle protein during periods of protein deficiency.
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