Asahikawa Medical College Hospital

Lactoferrin (LF) is present in tears, nasal secretions, saliva, and milk and maintains mucosal homeostasis. The palatine tonsils represent the first immune tissue to recognize pathogens invading the oral cavity via Toll-like receptors (TLRs). We aimed to investigate the effects of bovine LF on tonsillar immune cells stimulated with ligands of TLR7 or TLR9, which recognize viral single-stranded RNA or bacterial unmethylated CpG DNA. Mononuclear cells isolated from palatine tonsils of patients with recurrent tonsillitis or immunoglobulin A (IgA) nephropathy were cultured with LF, TLR7, or TLR9 ligands. Under TLR7 stimulation, LF enhanced the activation of plasmacytoid dendritic cells (pDCs), T-killer cells, and B cells without inducing inflammatory cytokines. In contrast, under TLR9 stimulation, LF suppressed the activation of pDCs, myeloid dendritic cells, T-helper cells, T-killer cells, B cells, and natural killer cells, as well as the production of TNF-α and IL-6. Moreover, LF decreased the production of the B-cell activation factor (BAFF), a proliferation-inducing ligand (APRIL), and galactose-deficient IgA1, all of which are risk factors of IgA nephropathy. Overall, LF may enhance the immune response against viruses and contribute to immune tolerance against commensal bacteria in the palatine tonsils, indicating potential benefits in managing cold-like symptoms, recurrent tonsillitis, and IgA nephropathy.

RNA dysregulation mediated by aberrant RNA-binding proteins (RBPs) is closely associated with tumorigenesis. However, the tumorigenic mechanisms of each RBP remained unclear. In this study, we demonstrate that downregulation of Splicing factor 3A1 (SF3A1) markedly suppressed the proliferation of colorectal cancer (CRC) cells, with minimal cytotoxicity observed in non-cancerous epithelial cells. The tumor-promoting function of SF3A1 was further validated in an HCT116 xenograft mouse model. Multiple apoptosis assays-including TdT-mediated dUTP nick end labeling (TUNEL) staining, poly-ADP-ribose polymerase (PARP) immunoblotting, and caspase-3/7 activity measurements-showed that SF3A1 inhibited apoptotic signaling in CRC cells. Transcriptome analysis, combined with RNA-immunoprecipitation (RIP), identified Syntaxin 12 (STX12) as a downstream effector of SF3A1. Knockdown of STX12 induced apoptosis in CRC cells but had no effect on the viability of non-cancerous HCEC-1CT epithelial cells. Furthermore, STX12 mRNA levels were significantly reduced following SF3A1 knockdown, indicating that SF3A1-mediated stabilization of STX12 contributes to apoptosis resistance in CRC cells. Collectively, our findings establish that SF3A1 promotes CRC progression by stabilizing STX12 mRNA and selectively inhibiting apoptosis in malignant cells, thereby identifying the SF3A1-STX12 regulatory axis as a novel and selective therapeutic target for CRC.

Recent advances in sequencing technologies have significantly contributed to the identification of disease-associated gene variants. However, a substantial number of patients, particularly those presenting with atypical neuromuscular phenotypes, remain genetically undiagnosed. Herein, we report a case of a Japanese patient with myasthenic symptoms in the eyelids and limbs rather than periodic paralysis having a novel heterozygous variant (c.611C>T) located at the 3′ end of exon 4 in SCN4A . The analysis of the proband’s SCN4A mRNA showed that this variant causes an alanine-to-valine missense change at the amino acid position of 204 (p.A204V, 39%) and a disruption of the splicing of exons 4 and 5 leading to the production of truncated Nav1.4 variant protein (p.A204Vfs*94, 4%). We anticipated that the p.A204V missense change would impair Nav1.4 function; however, the ion channel activity and membrane targeting of p.A204V Nav1.4 were found to be wild-type (WT)-like. We also examined the cytotoxicities of the p.A204V and p.A204Vfs*94 variants; however, the cell lines heterologously overexpressing these Nav1.4 variant proteins did not induce cell death any more than the WT control. Although the loss or gain of anomalous ion channel function that is commonly suspected in channelopathies was ruled out in the present case, the precise mechanism of the pathogenic role of c.611C>T SCN4A remains to be elucidated.

Study participants with rheumatoid arthritis (RA) have an elevated risk for nontuberculous mycobacterial pulmonary disease (NTM-PD), which limits the treatments for RA. Biomarkers for NTM-PD in study participants with RA are required. Patients with NTM-PD have been studied for small-molecule metabolites, although few have been performed for NTM-PD associated with RA. Therefore, we performed lipidomic profiling of NTM-PD in the urine specimens of study participants with RA to discover useful biomarkers. Urine specimens provided by 90 study participants with RA, with or without NTM-PD were subjected to lipidomic analysis. Univariate analysis found that the urinary concentrations of lysophosphatidic acid (LPA) 22:5 and phosphatidic acid (PA) 36:1 were altered in study participants with RA and NTM-PD (respective areas under the curves of receiver operating characteristic (AUROCs) were 0.977 and 0.811; P = 3.83 × 10−20 and 1.37 × 10−5), when compared with the levels in urine specimens of study participants with RA without NTM-PD. The partial least squares-discriminant analysis model created from these two phospholipids validated their ability to discriminate between the study participants with or without NTM-PD (AUROC: 0.988 [95% confidence interval 0.958–1.000]). Differences between the urinary levels of the phospholipids LPA and PA in study participants with RA and with or without NTM-PD were significant. Lipidomic profiling of urine samples should be effective in the process of evaluating biomarkers for NTM-PD associated with RA.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19452-2.

Recent advances in therapy have significantly improved long-term survival in pediatric B-cell acute lymphoblastic leukemia (B-ALL). However, relapse still occurs in 15-20 % of cases, and post-relapse survival rates remain suboptimal at 30-60 %. Therefore, novel therapeutic strategies effective against both primary and relapsed B-ALL are needed. In this study, we treated B-ALL cells with the cell-free culture supernatants (CFCS) of various probiotic strains and found that Aspergillus niger exerted the most potent inhibitory effect on B-ALL cell viability. Liquid chromatography-mass spectrometry analysis following fractionation of the CFCS identified glucose oxidase (GOx) as a key component enriched in the active antitumor fraction. GOx significantly reduced the viability of Reh cells and patient-derived B-ALL cells while exhibiting minimal cytotoxicity against peripheral blood mononuclear cells. Mechanistically, GOx reduced glucose levels and increased hydrogen peroxide levels in the culture medium. Encapsulation of GOx in calcium nanoparticles significantly prolonged survival in a patient-derived xenograft mouse model established from relapsed B-ALL. GOx induced both apoptotic and necrotic cell death in B-ALL cells and exhibited additive antitumor activity when combined with vincristine or doxorubicin. These findings suggest that GOx selectively induces cell death in B-ALL cells and may enhance therapeutic efficacy when used in combination with standard chemotherapeutics.

Multiple myeloma (MM) is a hematological malignancy characterized by a poor prognosis. While certain probiotics have been shown to produce antitumor molecules that inhibit solid tumor progression, it remains unclear whether probiotic-derived compounds can exert similar effects on hematological tumors, such as MM. In this study, we screened the cell-free culture supernatants (CFCS) of 24 probiotic strains for antitumor effects against multiple myeloma (MM) cells and identified that the CFCS from Clostridium butyricum (C. butyricum) demonstrated the most significant reduction in MM cell viability. Further fractionation of this CFCS through reverse-phase and gel filtration chromatography revealed a high enrichment of butyrate in the antitumor fraction, as confirmed by gas chromatography-mass spectrometry. Butyrate reduced MM cell viability in a concentration-dependent manner. Butyrate was significantly more cytotoxic to RPMI-8226 cells than peripheral blood mononuclear cells (PBMCs) isolated from two non-cancerous individuals. In the xenograft model of RPMI-8226 cells, butyrate showed significant inhibition of tumor formation. Cell cycle analysis showed that butyrate induced G1 phase arrest and increased sub-G1 phase, suggesting DNA fragmentation. Western blot analysis demonstrated that butyrate treatment led to cleaved poly ADP-ribose polymerase (PARP) accumulation. Additionally, flow cytometry showed an increase in annexin V positive MM cells, indicating apoptosis. Butyrate also exhibited synergistic antitumor activity when combined with bortezomib, a proteasome inhibitor. These findings suggest that probiotic-derived molecules, including butyrate, may enhance the therapeutic effect of hematological malignancy, such as MM.

Alien species can influence populations of native species through individual-level effects such as predation, competition, and poisoning. For alien species that possess strong defensive chemicals, poisoning is one of the most powerful mechanisms of individual-level effects on native biota. Although toxic alien species could potentially negatively affect survival (lethal effects) or life history traits (sub-lethal effects) of native predators via poisoning, previous studies have mainly focused on acute lethal effects. Thus, delayed effects on predator life history traits have been largely overlooked. To fill this knowledge gap, we conducted laboratory and field experiments to investigate whether toxic alien prey (hatchlings and tadpoles of an invasive toad, Bufo formosus) affect the survival and/or growth and development of a native predatory salamander (larvae of Hynobius retardatus) on Hokkaido, Japan. The laboratory experiment revealed that consumption of a single toad hatchling exerted non-lethal effects on salamanders, but suppressed both salamander growth and development of an ecological phenotype (broad-gape) normally induced by environmental conditions. Furthermore, the field experiment in a natural pond showed that the presence of toad hatchlings and tadpoles resulted in reduced salamander growth (smaller body size) and lower survival of salamanders in the later larval period. The results of the laboratory and field experiments are complementary evidence of the life history impacts of the toxic alien toad on native salamanders. Thus, the poisoning effects of toxic alien species can affect the life history of native predators even if they do not exert acute lethality.

To determine the impacts of global warming on pollinator-plant interactions, we recorded phenological variations in alpine flowers and bumble bees during 10–12 years in northern Japan, and analyzed the effects of weather conditions and phenological shift on worker population dynamics of four Bombus species. Flowering patterns of alpine plants were formed by the combination of early-flowering fellfield and late-flowering snowbed communities, where snowbed flowers were important resources for worker bees. The flowering phenology of the fellfield communities was correlated with early season air temperature, whereas that of the snowbed communities was clearly predicted by snowmelt time. It was predicted that 1 °C warming with 10 days earlier snowmelt would advance the peak flowering time of the fellfield and snowbed communities by 3.6 and 9.5 days, respectively, resulting in a 9.2 day shorter flowering period. In contrast, the peak time of worker abundance was consistent between years, independent of temperature and snowmelt time. As a result, the time lag between the peak flowering of snowbed plants and the peak abundance of worker bees, i.e., the phenological mismatch, increased with earlier snowmelt. Mid-summer temperature was negatively correlated with worker abundance for three Bombus species, and the effect of phenological mismatch varied between Bombus species. The abundance of B. hypocrita decreased with increasing phenological mismatch in the previous year, the abundance of B. beaticola and B. yezoensis increased, and B. hypnorum showed no clear response. Therefore, changes in the phenology of alpine plants due to global warming affect pollinators in highly species-specific ways.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00442-025-05775-4.

Glucose transporter 1 deficiency syndrome (GLUT1DS), caused by impaired glucose transport at the blood–brain barriers, leads to various central nervous system dysfunctions. A comprehensive understanding of the underlying disease pathogenesis is still lacking. In this study, we have generated GLUT1DS-specific human induced pluripotent stem cells (hiPSCs) derived from two patients. These established GLUT1DS-specific hiPSC lines showed self-renewal and pluripotency and carried heterozygous frameshift or missense mutations in the responsible SLC2A1 gene. These novel cell resources provide new avenues for understanding disease mechanisms and developing new therapies for GLUT1DS.