• Title/Summary/Keyword: endogenous

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Endogenous Stem Cells in the Ear (귀에 존재하는 내인성 성체줄기세포)

  • Park, Kyoung Ho
    • Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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    • v.56 no.12
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    • pp.749-753
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    • 2013
  • Basically stem cells have characteristics of multi-potency, differentiation into multiple tissue types, and self-renew through proliferation. Recent advances in stem cell biology can make identifying the stem-cell like cells in various mammalian tissues. Stem cells in various tissues can restore damaged tissue. Stem cells from the adult nervous system proliferate to form clonal floating colonies called spheres in vitro, and recent studies have demonstrated sphere formation by cells in the tympanic membrane, vestibular system, spiral ganglion, and partly in the organ of Corti. The presence of stem cells in the ear raises the possibilities for the regeneration of the tympanic membrane & inner ear hair cells & neurons. But the gradual loss of stem cells postnatally in the organ of Corti may correlate with the loss of regenerative capacity and limited hearing restoration. Future strategies using endogenous stem cells in the ear can be the another treatment modality for the patients with intractable inner ear diseases.

Crosstalk between RNA silencing and RNA quality control in plants

  • Yun Ju Kim
    • BMB Reports
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    • v.56 no.6
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    • pp.321-325
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    • 2023
  • RNAs are pivotal molecules acting as messengers of genetic information and regulatory molecules for cellular development and survival. From birth to death, RNAs face constant cellular decision for the precise control of cellular function and activity. Most eukaryotic cells employ conserved machineries for RNA decay including RNA silencing and RNA quality control (RQC). In plants, RQC monitors endogenous RNAs and degrades aberrant and dysfunctional species, whereas RNA silencing promotes RNA degradation to repress the expression of selected endogenous RNAs or exogenous RNA derived from transgenes and virus. Interestingly, emerging evidences have indicated that RQC and RNA silencing interact with each by sharing target RNAs and regulatory components. Such interaction should be tightly organized for proper cellular survival. However, it is still elusive that how each machinery specifically recognizes target RNAs. In this review, we summarize recent advances on RNA silencing and RQC pathway and discuss potential mechanisms underlying the interaction between the two machineries.

The Boundaries of MM2: An Exploration of Equity Value Indeterminacy

  • Hyoung-Goo Kang
    • 한국벤처창업학회:학술대회논문집
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    • 2023.11a
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    • pp.69-71
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    • 2023
  • The Modigliani-Miller Proposition II (MM2) is a cornerstone in the field of corporate finance, positing that in a frictionless environment with perfect capital markets, the cost of equity capital is linearly related to a firm's leverage. This paper critically re-evaluates this proposition, particularly examining the determination of the cost and value of equity. We find that under specific circum-stances, especially when the value of a tax shield is influenced by endogenous variables, the cost and value of equity may be ambiguous. This calls into question the universal applicability of MM2. Our research offers new perspectives on the theoretical underpinnings of financial management and underscores the significance of situational factors in the practical application of these theories.

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ErbB3 binding protein 1 contributes to adult hippocampal neurogenesis by modulating Bmp4 and Ascl1 signaling

  • Youngkwan Kim;Hyo Rim Ko;Inwoo Hwang;Jee-Yin Ahn
    • BMB Reports
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    • v.57 no.4
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    • pp.182-187
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    • 2024
  • Neural stem cells (NSCs) in the adult hippocampus divide infrequently; the endogenous molecules modulating adult hippocampal neurogenesis (AHN) remain largely unknown. Here, we show that ErbB3 binding protein 1 (Ebp1), which plays important roles in embryonic neurodevelopment, acts as an essential modulator of adult neurogenic factors. In vivo analysis of Ebp1 neuron depletion mice showed impaired AHN with a low number of hippocampal NSCs and neuroblasts. Ebp1 leads to transcriptional repression of Bmp4 and suppression of Ascl1 promoter methylation in the dentate gyrus of the adult hippocampus reflecting an unusually high level of Bmp4 and low Ascl1 level in neurons of Ebp1-deficient mice. Therefore, our findings suggests that Ebp1 could act as an endogenous modulator of the interplay between Bmp4 and Ascl1/Notch signaling, contributing to AHN.