Publications by authors named "Atsufumi Ozoe"

Insulin receptor (IR) pre-mRNA undergoes alternative splicing that produces two isoforms, IR-A and IR-B. The ratio of IR-A to IR-B varies among tissues, which strongly suggests that IR mRNA alternative splicing is regulated in a tissue-specific manner. However, the precise molecular mechanism for IR alternative splicing remains to be elucidated, especially in liver.

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Objective- IGF-1 (insulin-like growth factor 1) is a major autocrine/paracrine growth factor, which promotes cell proliferation, migration, and survival. We have shown previously that IGF-1 reduced atherosclerosis and promoted features of stable atherosclerotic plaque in Apoe mice-an animal model of atherosclerosis. The aim of this study was to assess effects of smooth muscle cell (SMC) IGF-1 signaling on the atherosclerotic plaque.

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Intramuscular adipose tissue and fibrous tissue are observed in some skeletal muscle pathologies such as Duchenne muscular dystrophy and sarcopenia, and affect muscle strength and myogenesis. They originate from common fibrogenic/adipogenic cells in the skeletal muscle. Thus, elucidating the regulatory mechanisms underlying fibrogenic/adipogenic cell differentiation is an important step toward the mediation of these disorders.

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Article Synopsis
  • * Researchers discovered that insulin receptor substrates (IRSs) form large complexes (called IRSomes) even without IGF/insulin stimulation, containing proteins that influence IRS function and stability.
  • * The presence of proteins and RNAs in IRSomes suggests they may help modulate insulin-like signaling, making them potential targets for treating age-related diseases, including cancer.
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Article Synopsis
  • Insulin receptor substrates (IRSs) are important for transmitting signals from insulin-like growth factors and insulin within cells, and IRS-1 has been found to form complexes that include specific RNAs.
  • We used UV cross-linking and immunoprecipitation methods on HEK293 cells to identify RNAs associated with IRS-1, revealing interactions with 25 messenger RNAs and 8 non-coding RNAs, highlighting IRS-1's specific relationship with the U96A snoRNA and Rack1 pre-mRNA.
  • The study suggests that IRS-1 plays an unexpected role in the biogenesis of snoRNAs, indicating that its RNA-associated complexes could lead to new insights into how IGFs and insulin regulate biological processes.
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Insulin receptor substrates (IRSs) are known to play important roles in mediating intracellular insulin-like growth factors (IGFs)/insulin signaling. In this study, we identified components of messenger ribonucleoprotein (mRNP) as IRS-1-associated proteins. IRS-1 complex formation analysis revealed that IRS-1 is incorporated into the complexes of molecular mass more than 1000 kDa, which were disrupted by treatment with RNase.

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Insulin receptor substrates (IRSs) are phosphorylated by activated insulin/insulin-like growth factor (IGF)-I receptor tyrosine kinases. Phosphotyrosyl IRSs are recognized by signaling molecules possessing src homology region 2 (SH2) domains, which mediate various insulin/IGF bioactivities. However, we have shown that IRSs are also associated with other proteins by a phosphotyrosine-independent mechanism.

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The aim of this study was to determine the types of Toll-like receptors (TLRs) expressed in the hen oviduct, and to confirm that vaginal tissue expressing TLR4 responds to lipopolysaccharide (LPS). Healthy laying hens were intravenously or intravaginally injected with LPS, PBS or untreated. The expression pattern of TLRs in the whole oviduct and the effects of LPS on TLR4 and IL-1beta in the vagina were examined by semi-quantitative RT-PCR.

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