Biology subjects

Nagamatsu, T.

Publications and source records attributed to Nagamatsu, T..

3 recordsLinked to original sources

bioRxiv2026

Mouse suppressyn-like 1 is an endogenous retrovirus-derived inhibitor of membrane fusion through direct association with envelope glycoproteins

Cell-cell fusion is essential for placental development and is mediated by endogenous retrovirus (ERV)-derived fusogens known as syncytins. However, how ERV-derived proteins negatively regulate membrane fusion remains largely unknown. Here, we identify a previously uncharacterized murine ERV envelope-derived protein, mouse suppressyn-like 1 (mSUPYNL1), that suppresses syncytin-mediated membrane fusion through a mechanism distinct from that of placental human suppressyn (hSUPYN). Unlike hSUPYN, which acts through receptor interference, mSUPYNL1 inhibits both murine and human syncytin-mediated fusion independently of receptor usage by associating with the surface (SU) subunits of multiple syncytin envelope glycoproteins, revealing a receptor-independent mechanism of fusion suppression. This mechanism extends beyond endogenous fusogens. mSUPYNL1 also associates with the SU glycoprotein (gp46) of Human T-cell Leukemia Virus type 1 (HTLV-1) and suppresses Env-dependent syncytium formation, whereas hSUPYN showed no detectable antiviral activity in this assay. These findings identify mSUPYNL1 as a broad-spectrum inhibitor of envelope glycoprotein-mediated membrane fusion. Analysis of mSUPYNL1 knockout mice revealed that, in contrast to the placenta-restricted expression of hSUPYN, mSUPYNL1 was broadly expressed, with its most prominent localization in decidual stromal and vascular endothelial cells of the pregnant uterus, as well as in hematopoietic tissues such as the spleen and thymus. Together, our findings uncover an evolutionarily distinct class of ERV-derived fusion suppressors that function through envelope glycoprotein recognition instead of receptor interference. Our study expands current models of ERV domestication by demonstrating that retroviral envelope proteins have been independently co-opted not only to promote membrane fusion but also to restrain it, thereby linking placental biology, antiviral defense, and host evolution. HIGHLIGHTSO_LImSUPYNL1 is an endogenous retrovirus-derived membrane fusion inhibitor C_LIO_LImSUPYNL1 binds the SU domains of murine and human syncytins C_LIO_LImSUPYNL1 suppresses HTLV-1 Env-mediated syncytium formation C_LIO_LIDirect envelope recognition enables receptor-independent fusion inhibition C_LI

developmental biology↗

bioRxiv2024

5-Deazaflavin (TND1128) and its hybrid analogs are cytoprotective against hydrogen peroxide (H2O2)-induced oxidative stress.

Increased production of reactive oxygen species (ROS) and oxidative stress are implicated in mitochondrial dysfunction, contributing to the pathogenesis of many neurodegenerative diseases. Research is ongoing into a new treatment approach for neurodegeneration, focusing on reactivating dysfunctional mitochondria. Some 5-deazaflavins, such as 10-ethyl-3-methylpyrimido[4,5-b]quinoline-2,4(3H,10H)-dione (TND1128), and four analogs of 5-deazaflavin, including {beta}-nicotinamide mononucleotide ({beta}-NMN), demonstrate efficient self-redox abilities similar to {beta}-NMN, making them potential activators of mitochondrial energy synthesis. This study examines whether TND1128 and its analogs have protective effects against cellular impairment induced by oxidative stress. These compounds exhibit proliferative potential against normal cells. Moreover, TND1128 and its analogs significantly improved cell viability against hydrogen peroxide (H2O2)-induced oxidative stress injury. Our study confirms the cytoprotective effect of these 5-deazaflavins through mitochondrial activation. We anticipate TND1128 and its analogs will serve as mitochondria-stimulating drugs capable of rescuing deteriorating neurons in aging or diseases.

pharmacology and toxicology↗

bioRxiv2024

Impact of perinatal maternal docosahexaenoic acid-containing phospholipid synthesis on offspring growth and neurological symptoms

Mothers provide essential nutrients, including docosahexaenoic acid (DHA), an omega-3 fatty acid, during the perinatal period. DHA deficiency in perinatal mothers is linked to developmental abnormalities, especially in the central nervous system of the offspring; however, its specific impact on distinct events in fetal and neonatal brain development and prospective brain functions remains incompletely understood. We demonstrated using mice lacking Agpat3, a gene encoding the enzyme that synthesizes DHA-containing phospholipids (DHA-PLs), that maternal DHA-PL synthesis significantly contributes to the maternal- offspring DHA supply during the fetal period but not in infancy. Selective modulation of DHA-PL levels during fetal and postnatal periods in Agpat3-knockout mice showed that fetal stage-specific insufficiency in maternal DHA-PL supply potentially influences the neuropsychiatric phenotype in adult mice without affecting postnatal tissue DHA-PL levels, weight gain, and brain expansion. Collectively, enhancing maternal DHA-PL synthesis during pregnancy may help prevent prospective neuropsychiatric abnormalities in the offspring.

biochemistry↗