The increasing use of nuclear energy sources inevitably raises the risk of accidental or deliberate radiation exposure and associated immune dysfunction. However, the extent to which radiation exposure impacts memory CD8 T cells, potent mediators of immunity to recurring intracellular infections and malignancies, remains understudied. Using P14 CD8 T cell chimeric mice (P14 chimeras) with an lymphocytic choriomeningitis virus (LCMV) infection model, we observed that sublethal (5Gy) whole-body irradiation (WBI) induced a rapid decline in the number of naive (T) and P14 circulating memory CD8 T cells (T), with the former being more susceptible to radiation-induced numeric loss.
View Article and Find Full Text PDFBy promoting anabolism, MTORC1 is critical for muscle growth and maintenance. However, genetic MTORC1 upregulation promotes muscle aging and produces age-associated myopathy. Whether MTORC1 activation is sufficient to produce myopathy or indirectly promotes it by accelerating tissue aging is elusive.
View Article and Find Full Text PDFSpatial barcoding technologies have the potential to reveal histological details of transcriptomic profiles; however, they are currently limited by their low resolution. Here, we report Seq-Scope, a spatial barcoding technology with a resolution comparable to an optical microscope. Seq-Scope is based on a solid-phase amplification of randomly barcoded single-molecule oligonucleotides using an Illumina sequencing platform.
View Article and Find Full Text PDFVernalization accelerates flowering after prolonged winter cold. Transcriptional and epigenetic changes are known to be involved in the regulation of the vernalization response. Despite intensive applications of next-generation sequencing in diverse aspects of plant research, genome-wide transcriptome and epigenome profiling during the vernalization response has not been conducted.
View Article and Find Full Text PDFmTORC1 is a protein kinase important for metabolism and is regulated by growth factor and nutrient signaling pathways, mediated by the Rheb and Rag GTPases, respectively. Here we provide the first animal model in which both pathways were upregulated through concurrent mutations in their GTPase-activating proteins, and . Unlike former models that induced limited mTORC1 upregulation, hepatic deletion of both and (DKO) produced strong, synergistic activation of the mTORC1 pathway and provoked pronounced and widespread hepatocyte damage, leading to externally visible liver failure phenotypes, such as jaundice and systemic growth defects.
View Article and Find Full Text PDFThough the G(1) checkpoint in mammalian cells has been known for decades, the molecular targets that prevent S-phase entry remain unknown. Mimosine is a rare plant amino acid that arrests the cell cycle in the G(1) phase before entry into S phase. Here, we show that mimosine interrupts the binding of Ctf4 to chromatin, which is essential for the initiation of DNA replication in HeLa cells, and this effect is mediated by the Hif-1α-dependent increase in the level of p27.
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