Publications by authors named "Na-Yeon Park"

Melanosomes play a pivotal role in skin color and photoprotection. In contrast to the well-elucidated pathway of melanosome biogenesis, the process of melanosome degradation, referred to as melanophagy, is largely unexplored. Previously, we discovered that 3,4,5-trimethoxycinnamate thymol ester (TCTE) effectively inhibits skin pigmentation by activating melanophagy.

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Migrasomes, the newly discovered cellular organelles that form large vesicle-like structures on the retraction fibers of migrating cells, are thought to be involved in communication between neighboring cells, cellular content transfer, unwanted material shedding, and information integration. Although their formation has been described previously, the molecular mechanisms of migrasome biogenesis are largely unknown. Here, we developed a cell line that overexpresses GFP-tetraspanin4, enabling observation of migrasomes.

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  • Primary cilia are essential for sensing external conditions and maintaining cellular balance; mutations in related genes can lead to hereditary diseases like nephronophthisis.
  • Our study shows that reducing the protein PDIA6 removes primary cilia, increases sensitivity to cell death from endoplasmic reticulum (ER) stress, and intensifies the stress response.
  • Targeting ER stress can counteract the negative effects of PDIA6 loss, restoring primary cilia and implicating PDIA6 as a potential therapeutic target for ciliopathies.
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  • Hypoxic responses are linked to various health issues like inflammation and cancer, sparking interest in natural remedies.
  • Recent findings show that Lactiplantibacillus plantarum K8 (K8) has anti-inflammatory effects, but its impact on hypoxia-related cellular responses was previously unknown.
  • This study reveals that K8 lysates can significantly suppress HIF1α accumulation and target gene expression under hypoxic conditions, suggesting a unique role in regulating cellular responses to low oxygen levels.
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Autophagy is a pivotal biological process responsible for maintaining the homeostasis of intracellular organelles. Yet the molecular intricacies of peroxisomal autophagy (pexophagy) remain largely elusive. From a ubiquitin-related chemical library for screening, we identified several inhibitors of the Von Hippel-Lindau (VHL) E3 ligase, including VH298, thereby serving as potent inducers of pexophagy.

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The primary cilium, an antenna-like structure on the cell surface, acts as a mechanical and chemical sensory organelle. Primary cilia play critical roles in sensing the extracellular environment to coordinate various developmental and homeostatic signaling pathways. Here, we showed that the depletion of heat shock protein family A member 9 (HSPA9)/mortalin stimulates primary ciliogenesis in SH-SY5Y cells.

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Selective autophagy controls cellular homeostasis by degrading unnecessary or damaged cellular components. Melanosomes are specialized organelles that regulate the biogenesis, storage, and transport of melanin in melanocytes. However, the mechanisms underlying melanosomal autophagy, known as the melanophagy pathway, are poorly understood.

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  • Researchers explored the regulatory mechanisms of pexophagy (peroxisomal autophagy) and found that BRD4 inhibitors can induce this process, specifically highlighting molibresib as a key compound.
  • Treatment with molibresib leads to the selective loss of peroxisomes in HeLa cells, without affecting other cellular structures like mitochondria or the Golgi apparatus.
  • The study indicates that molibresib increases reactive oxygen species (ROS) and activates ATM, which are crucial for promoting pexophagy through BRD4 inhibition.
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Primary cilia help to maintain cellular homeostasis by sensing conditions in the extracellular environment, including growth factors, nutrients, and hormones that are involved in various signaling pathways. Recently, we have shown that enhanced primary ciliogenesis in dopamine neurons promotes neuronal survival in a Parkinson's disease model. Moreover, we performed fecal metabolite screening in order to identify several candidates for improving primary ciliogenesis, including L-carnitine and acetyl-L-carnitine.

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In recent decades, dopant-free Si-based solar cells with a transition metal oxide layer have gained noticeable research interest as promising candidates for next-generation solar cells with both low manufacturing cost and high power conversion efficiency. Here, we report the effect of the substrate temperature for the deposition of vanadium oxide (VO, 0 ≤ X ≤ 5) thin films (TFs) for enhanced Si surface passivation. The effectiveness of SiO formation at the Si/VO interface for Si surface passivation was investigated by comparing the results of minority carrier lifetime measurements, X-ray photoelectron spectroscopy, and atomic force microscopy.

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  • * ATG4 proteins, particularly ATG4A-D, are crucial in regulating autophagy by assisting in the maturation of autophagosomes through interactions with ATG8 homologs like LC3.
  • * Recent studies focus on how various post-translational modifications of ATG4 impact its activity and the overall process of autophagy, highlighting its role as a key regulator in cellular health.
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In the last decades, the conductive polymer PEDOT:PSS has been introduced in Si-based hybrid solar cells, gaining noticeable research interest and being considered a promising candidate for next generation solar cells which can achieve both of low manufacturing cost and high power conversion efficiency. This study succeeded in improving the electrical conductivity of PEDOT:PSS to 937 S/cm through a simple process of adding hydroquinone (HQ) to the pristine PEDOT:PSS solution. The results also showed that the addition of HQ to PEDOT:PSS(HQ-PEDOT:PSS) could not only dramatically improve the conductivity but also well-sustain the work function characteristics of PEDOT:PSS by promoting the formation of more continuous conductive-PEDOT channels without removing the insulating PSS.

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Ir is one of the most efficient oxygen evolution reaction (OER) catalysts; however, it is also one of the rarest and most expensive elements. Therefore, it is highly desirable to develop Ir catalysts with nanostructures that reduce Ir consumption by maximizing the surface-to-volume ratio without limiting the mass transport of reactants and products of reactions. Ir OER catalysts on a template that consisted of porous nanotubes (PNTs) based on Ni are fabricated.

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Particulate matters (PMs) increase oxidative stress and inflammatory response in different tissues. PMs disrupt the formation of primary cilia in various skin cells, including keratinocytes and melanocytes. In this study, we found that 2-isopropylmalic acid (2-IPMA) promoted primary ciliogenesis and restored the PM2.

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Primary cilia mediate the interactions between cells and external stresses. Thus, dysregulation of primary cilia is implicated in various ciliopathies, e.g.

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The maintenance of lysosomal integrity is essential for lysosome function and cell fate. Damaged lysosomes are degraded by lysosomal autophagy, lysophagy. The mechanism underlying lysophagy remains largely unknown; this study aimed to contribute to the understanding of this topic.

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Arsenic is reportedly a biphasic inorganic compound for its toxicity and anticancer effects in humans. Recent studies have shown that certain arsenic compounds including arsenic hexoxide (ASO; hereafter, AS6) induce programmed cell death and cell cycle arrest in human cancer cells and murine cancer models. However, the mechanisms by which AS6 suppresses cancer cells are incompletely understood.

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Peroxisomes play an essential role in cellular homeostasis by regulating lipid metabolism and the conversion of reactive oxygen species (ROS). Several peroxisomal proteins, known as peroxins (PEXs), control peroxisome biogenesis and degradation. Various mutations in the PEX genes are genetic causes for the development of inheritable peroxisomal-biogenesis disorders, such as Zellweger syndrome.

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In this report, we present a process for the fabrication and tapering of a silicon (Si) nanopillar (NP) array on a large Si surface area wafer (2-inch diameter) to provide enhanced light harvesting for Si solar cell application. From our ,-dimethyl-formamide (DMF) solvent-controlled spin-coating method, silica nanosphere (SNS in 310 nm diameter) coating on the Si surface was demonstrated successfully with improved monolayer coverage (>95%) and uniformity. After combining this method with a reactive ion etching (RIE) technique, a high-density Si NP array was produced, and we revealed that controlled tapering of Si NPs could be achieved after introducing a two-step RIE process using (1) CHF/Ar gases for SNS selective etching over Si and (2) Cl gas for Si vertical etching.

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As a dynamic organelle, mitochondria continuously fuse and divide with adjacent mitochondria. Imbalance in mitochondria dynamics leads to their dysfunction, which implicated in neurodegenerative diseases. However, how mitochondria alteration and glucose defect contribute to pathogenesis of Alzheimer's disease (AD) is still largely unknown.

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The melanosome is a specialized membrane-bound organelle that is involved in melanin synthesis, storage, and transportation. In contrast to melanosome biogenesis, the processes underlying melanosome degradation remain largely unknown. Autophagy is a process that promotes degradation of intracellular components' cooperative process between autophagosomes and lysosomes, and its role for process of melanosome degradation remains unclear.

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In recent decades, the role of the peroxisome in physiology and disease conditions has become increasingly important. Together with the mitochondria and other cellular organelles, peroxisomes support key metabolic platforms for the oxidation of various fatty acids and regulate redox conditions. In addition, peroxisomes contribute to the biosynthesis of essential lipid molecules, such as bile acid, cholesterol, docosahexaenoic acid, and plasmalogen.

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Melanosomes are specialized membrane-bound organelles that are involved in melanin synthesis. Unlike melanosome biogenesis, the melanosome degradation pathway is poorly understood. Among the cellular processes, autophagy controls degradation of intracellular components by cooperating with lysosomes.

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Article Synopsis
  • Quality control of peroxisomes is crucial for maintaining cellular balance, but the specific process of pexophagy (the degradation of peroxisomes) is not well understood.
  • This study discovered HSPA9 as a key regulator of pexophagy; reducing its levels led to more general autophagy but fewer peroxisomes.
  • Elevated levels of reactive oxygen species (ROS) were observed in cells lacking HSPA9, and blocking ROS was found to inhibit pexophagy, indicating that HSPA9 plays a significant role in controlling peroxisome degradation.
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Mitochondria are essential for providing the energy necessary for neuronal function. Dysregulation of mitochondrial dynamics has been linked with the pathogenesis of many neurodegenerative diseases. Dynamin related protein 1 (Drp1) participates in fission activity in the mitochondria, and post-translational modifications to Drp1 modulate complex mitochondrial dynamics.

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