• Molecules and Cells
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• 제22권2호
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• pp.210-219
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• 2006

Dynamin-related protein 2A (AtDRP2A, formally ADL6), a member of the dynamin family, is critical for protein trafficking from the TGN to the central vacuole. However, the mechanism controlling its activity is not well understood in plant cells. We isolated Arabidopsis sec13 homolog1 (AtSeh1) that interacts with AtDRP2A by a yeast two-hybrid screening. AtSeh1 has four WD40 motifs and amino acid sequence homology to Sec13, a component of COPII vesicles. Coimmunoprecipitation and protein pull-down experiments demonstrated specific interaction between AtSeh1 and AtDRP2A. AtSeh1 bound to the pleckstrin homology domain of AtDRP2A in competition with the C-terminal domain of the latter, and this resulted in inhibition of the interaction between AtDRP2A and PtdIns3P in vitro. AtSeh1 localized to multiple locations: the nucleus, the prevacuolar compartment and the Golgi complex. Based on these results we propose that AtSeh1 plays a role in regulating cycling of AtDRP2A between membrane-bound and soluble forms.

• 생명과학회지
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• 제33권11호
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• pp.851-858
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• 2023

Unique cartilage matrix-associated protein (UCMA)은 γ-카르복실화(Gla) 잔기가 풍부한 간외 비타민 K 의존 단백질이다. UCMA는 조골세포 분화를 촉진하고 뼈 형성을 강화한다고 보고되고 있지만 고혈당 스트레스 하에서 조골세포에 미치는 영향에 대해서는 아직 알려진 바가 없다. 본 연구에서는 고혈당 조건하에서의 MC3T3-E1 조골세포에서 UCMA 효과를 조사하기 위해 MC3T3-E1 조골세포를 높은 포도당에 노출한 후 재조합 UCMA 단백질을 처리하였다. MC3T3-E1 세포에서 활성 산소종(ROS)의 생성은 고혈당 조건하에서 증가했으나 UCMA 단백질 처리 후 감소했음을 CellROX 및 MitoSOX 염색으로 확인하였다. 또한 고혈당 조건에서 UCMA 단백질을 함께 처리한 MC3T3-E1 세포에서 정량적 중합효소 연쇄반응 결과, 항산화 유전자인 nuclear factor erythroid 2-related factor 2 와 superoxide dismutase 1 발현이 증가하였다. 동일 조건하에서 UCMA 단백질 처리에 의해 heme oxygenase-1 발현 감소와 함께 세포질에서 핵으로의 전위가 감소되었고, 미토콘드리아 분열에 관여하는 dynamin-related protein 1 발현이 증가하였으며, AKT 신호 활성은 억제되었다. 종합적으로 UCMA는 고혈당에 노출된 조골세포에서 ROS 생성을 완화하고, 항산화 유전자 발현을 증가시키고, 미토콘드리아 역학에 영향을 미치며, AKT 신호를 조절하는 것으로 보인다. 본 연구는 UCMA의 세포 메커니즘에 대한 이해를 돕고, 대사 장애 관련한 골 합병증에 대한 새로운 치료제로서의 잠재적 사용 가능성을 제시하고 있다.

• Biomolecules & Therapeutics
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• 제30권5호
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• pp.409-417
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• 2022

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide, and accumulating evidence indicates that mitochondrial dysfunction is associated with progressive deterioration in PD patients. Previous studies have shown that sinapic acid has a neuroprotective effect, but its mechanisms of action remain unclear. The neuroprotective effect of sinapic acid was assayed in a PD mouse model generated by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as well as in SH-SY5Y cells. Target protein expression was detected by western blotting. Sinapic acid treatment attenuated the behavioral defects and loss of dopaminergic neurons in the PD models. Sinapic acid also improved mitochondrial function in the PD models. MPTP treatment increased the abundance of mitochondrial fission proteins such as dynamin-related protein 1 (Drp1) and phospho-Drp1 Ser616. In addition, MPTP decreased the expression of the REV-ERB α protein. These changes were attenuated by sinapic acid treatment. We used the pharmacological REV-ERB α inhibitor SR8278 to confirmation of protective effect of sinapic acid. Treatment of SR8278 with sinapic acid reversed the protein expression of phospho-Drp1 Ser616 and REV-ERB α on MPTP-treated mice. Our findings demonstrated that sinapic acid protects against MPTP-induced PD and these effects might be related to the inhibiting abnormal mitochondrial fission through REV-ERB α.

• BMB Reports
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• 제40권3호
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• pp.302-314
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• 2007

N type calcium channels (CaV2.2) play a key role in the gating of transmitter release at presynaptic nerve terminals. These channels are generally regarded as parts of a multimolecular complex that can modulate their open probability and ensure their location near the vesicle docking and fusion sites. However, the proteins that comprise this component remain poorly characterized. We have carried out the first open screen of presynaptic CaV2.2 complex members by an antibody-mediated capture of the channel from purified rat brain synaptosome lysate followed by mass spectroscopy. 589 unique peptides resulted in a high confidence match of 104 total proteins and 40 synaptosome proteome proteins. This screen identified several known CaV2.2 interacting proteins including syntaxin 1, VAMP, protein phosphatase 2A, $G_{o\alpha}$, G$\beta$ and spectrin and also a number of novel proteins, including clathrin, adaptin, dynamin, dynein, NSF and actin. The unexpected proteins were classified within a number of functional classes that include exocytosis, endocytosis, cytoplasmic matrix, modulators, chaperones, and cell-signaling molecules and this list was contrasted to previous reports that catalogue the synaptosome proteome. The failure to detect any postsynaptic density proteins suggests that the channel itself does not exhibit stable trans-synaptic attachments. Our results suggest that the channel is anchored to a cytoplasmic matrix related to the previously described particle web.

• 한국발생생물학회지:발생과생식
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• 제26권2호
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• pp.71-77
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• 2022

In response to luteinizing hormone (LH), a higher concentration of progesterone (P4) is produced in luteal cells of corpus luteum (CL). Mitochondria are an essential cellular organelle in steroidogenesis. The specific engagement of the concept regarding mitochondrial shaping with early stages of steroidogenesis was suggested in reproductive endocrine cells. Although the specific involvement of GTPase dynamin-related protein 1 (Drp1) with steroidogenesis has been demonstrated in luteal cells of bovine CL in vitro, its actual relationship with ovarian steroidogenesis during the estrous cycle remains unknown. In this study, while Fis1 and Opa1 protein levels did not show significant changes during the estrous cycle, Drp1, Mfn1, and Mfn2 proteins exhibited relatively lower levels at proestrus than at estrus or diestrus. 3β-HSD showed higher levels at proestrus than at estrus or diestrus. In addition, Drp1 phosphorylation (s637) was higher in proestrus than in estrus or diestrus. Immune-positive cells for Drp1, pDrp1 (s637), and 3β-HSD were all localized in the cytoplasm of luteal cells in the CL. The immune-positive cells for 3β-HSD were more frequently seen in the CL at proestrus than at estrus or diestrus. Immunoreactivity for Drp1 in luteal cells at proestrus was weaker than that at estrus or diestrus. However, pDrp1 (s637) immune-positive cells were mostly detected in luteal cells at proestrus. These results imply that steroidogenesis (P4 production) in the CL is closely related to phosphorylation of Drp1 at serine 637. Taken together, this study presents evidence that Drp1 phosphorylation at serine 637 is an important step in steroidogenesis in the CL.

• Molecules and Cells
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• 제42권12호
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• pp.893-905
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• 2019

Mitochondria are highly dynamic organelles that constantly undergo fission and fusion processes that closely related to their function. Disruption of mitochondrial dynamics has been demonstrated in acute kidney injury (AKI), which could eventually result in cell injury and death. Previously, we reported that augmenter of liver regeneration (ALR) alleviates renal tubular epithelial cell injury. Here, we gained further insights into whether the renoprotective roles of ALR are associated with mitochondrial dynamics. Changes in mitochondrial dynamics were examined in experimental models of renal ischemia-reperfusion (IR). In a model of hypoxia-reoxygenation (HR) injury in vitro, dynamin-related protein 1 (Drp1) and mitochondrial fission process protein 1 (MTFP1), two key proteins of mitochondrial fission, were downregulated in the Lv-ALR + HR group. ALR overexpression additionally had an impact on phosphorylation of Drp1 Ser637 during AKI. The inner membrane fusion protein, Optic Atrophy 1 (OPA1), was significantly increased whereas levels of outer membrane fusion proteins Mitofusin-1 and -2 (Mfn1, Mfn2) were not affected in the Lv-ALR + HR group, compared with the control group. Furthermore, the mTOR/4E-BP1 signaling pathway was highly activated in the Lv-ALR + HR group. ALR overexpression led to suppression of HR-induced apoptosis. Our collective findings indicate that ALR gene transfection alleviates mitochondrial injury, possibly through inhibiting fission and promoting fusion of the mitochondrial inner membrane, both of which contribute to reduction of HK-2 cell apoptosis. Additionally, fission processes are potentially mediated by promoting tubular cell survival through activating the mTOR/4E-BP1 signaling pathway.

• Animal Bioscience
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• 제35권3호
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• pp.367-376
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• 2022

Objective: The highly pathogenic avian influenza virus (HPAIV) is a threat to the poultry industry as well as the economy and remains a potential source of pandemic infection in humans. Antiviral genes are considered a potential factor for HPAIV resistance. Therefore, in this study, we investigated gene expression related to cytokine-cytokine receptor interactions by comparing resistant and susceptible Ri chicken lines for avian influenza virus infection. Methods: Ri chickens of resistant (Mx/A; BF2/B21) and susceptible (Mx/G; BF2/B13) lines were selected by genotyping the Mx dynamin like GTPase (Mx) and major histocompatibility complex class I antigen BF2 genes. These chickens were then infected with influenza A virus subtype H5N1, and their lung tissues were collected for RNA sequencing. Results: In total, 972 differentially expressed genes (DEGs) were observed between resistant and susceptible Ri chickens, according to the gene ontology and Kyoto encyclopedia of genes and genomes pathways. In particular, DEGs associated with cytokine-cytokine receptor interactions were most abundant. The expression levels of cytokines (interleukin-1β [IL-1β], IL-6, IL-8, and IL-18), chemokines (C-C Motif chemokine ligand 4 [CCL4] and CCL17), interferons (IFN-γ), and IFN-stimulated genes (Mx1, CCL19, 2'-5'-oligoadenylate synthase-like, and protein kinase R) were higher in H5N1-resistant chickens than in H5N1-susceptible chickens. Conclusion: Resistant chickens show stronger immune responses and antiviral activity (cytokines, chemokines, and IFN-stimulated genes) than those of susceptible chickens against HPAIV infection.

• Journal of Nutrition and Health
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• 제57권1호
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• pp.53-64
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• 2024

본 연구는 근생성 효능을 가진 천연화합물을 발굴하고자 oxypeucedanin hydrate가 근생성과 미토콘드리아에 미치는 영향 및 항암제 유도 미토콘드리아 손상에 대한 완화효과를 C2C12 근원세포와 zebrafish 모델을 통해 각각 확인하였다. 그 결과, oxypeucedanin hydrate는 다핵의 근관세포의 수와 분화말기 표지자인 Myh4의 발현량을 증가시켰고 근육단백질 분해 인자인 MuRF1과 MAFbx의 발현량은 감소시켰다. 또한 미토콘드리아 생합성 조절인자인 Pgc1α, Tfam과 전자전달계 구성인자인 Sdha, Cox1의 발현은 증가시키고, 미토콘드리아 융합인자인 Opa1의 발현 또한 증가시킴과 동시에 미토콘드리아 분열을 표지하는 Drp1의 발현은 감소시켰다. 한편 zebrafish 모델을 통해 항암제 유도 미토콘드리아 손상에 대한 개선효과를 확인한 결과, oxypeucedanin hydrate는 항암제에 의해 유도된 미토콘드리아 손상을 완화시켰다. 이상의 결과들은 oxypeucedanin hydrate가 미토콘드리아 기능 증진을 매개로 근원세포 분화 촉진 및 근육 단백질 분해 저하 효과를 나타냄을 시사한다. 따라서 본 연구를 통해 oxypeucedanin hydrate가 근생성 효과를 나타낼 수 있는 잠재적인 유효소재로서의 가능성을 제시하였다.

• Journal of Nutrition and Health
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• 제56권6호
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• pp.602-614
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• 2023

본 연구는 근생성 및 근위축 완화효능을 가진 유효소재 발굴의 필요성에 의해 polygalacin D가 근원세포 분화 및 미토콘드리아에 미치는 영향과 항암제 유도 근위축에 대한 완화효과를 각각 세포 및 동물실험을 통해 확인하고자 하였다. 그 결과, polygalacin D는 다핵을 지닌 근관세포의 수와 분화 종결인자인 MHC isoforms의 발현량을 증가시켰고 근육 내 단백질 분해 인자인 MuRF1, Smad2/3의 발현량은 유의적으로 감소시켰다. 또한 미토콘드리아 생합성 조절인자인 Pgc1α의 발현은 증가시키고 미토콘드리아 분열인자인 Drp1과 Fis1의 발현은 감소시켰다. 한편 zebrafish 동물모델을 통해 항암제 유도 근위축에 대한 개선효과를 확인한 결과, polygalacin D는 항암제에 의해 유도된 근위축과 미토콘드리아 손상을 완화시켰다. 이상의 결과들은 polygalacin D가 미토콘드리아 기능 증진을 매개로 근원세포 분화 촉진 및 근육 단백질 분해 저하 효과를 지닐 뿐만 아니라, 미토콘드리아 손상을 개선하여 항암제로 유도된 근위축에 대한 완화 효과를 나타냄을 시사한다. 따라서 본 연구를 통해 polygalacin D가 근생성 및 근위축 예방과 치료를 위한 잠재적인 유효소재로서의 가능성을 제시하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제22권2호
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• pp.203-213
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• 2018

Tumor undergo uncontrolled, excessive proliferation leads to hypoxic microenvironment. To fulfill their demand for nutrient, and oxygen, tumor angiogenesis is required. Endothelial progenitor cells (EPCs) have been known to the main source of angiogenesis because of their potential to differentiation into endothelial cells. Therefore, understanding the mechanism of EPC-mediated angiogenesis in hypoxia is critical for development of cancer therapy. Recently, mitochondrial dynamics has emerged as a critical mechanism for cellular function and differentiation under hypoxic conditions. However, the role of mitochondrial dynamics in hypoxia-induced angiogenesis remains to be elucidated. In this study, we demonstrated that hypoxia-induced mitochondrial fission accelerates EPCs bioactivities. We first investigated the effect of hypoxia on EPC-mediated angiogenesis. Cell migration, invasion, and tube formation was significantly increased under hypoxic conditions; expression of EPC surface markers was unchanged. And mitochondrial fission was induced by hypoxia time-dependent manner. We found that hypoxia-induced mitochondrial fission was triggered by dynamin-related protein Drp1, specifically, phosphorylated DRP1 at Ser637, a suppression marker for mitochondrial fission, was impaired in hypoxia time-dependent manner. To confirm the role of DRP1 in EPC-mediated angiogenesis, we analyzed cell bioactivities using Mdivi-1, a selective DRP1 inhibitor, and DRP1 siRNA. DRP1 silencing or Mdivi-1 treatment dramatically reduced cell migration, invasion, and tube formation in EPCs, but the expression of EPC surface markers was unchanged. In conclusion, we uncovered a novel role of mitochondrial fission in hypoxia-induced angiogenesis. Therefore, we suggest that specific modulation of DRP1-mediated mitochondrial dynamics may be a potential therapeutic strategy in EPC-mediated tumor angiogenesis.