• Title/Summary/Keyword: intact cells

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Utilizing Natural and Engineered Peroxiredoxins As Intracellular Peroxide Reporters

  • Laer, Koen Van;Dick, Tobias P.
    • Molecules and Cells
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    • v.39 no.1
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    • pp.46-52
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    • 2016
  • It is increasingly apparent that nature evolved peroxiredoxins not only as $H_2O_2$ scavengers but also as highly sensitive $H_2O_2$ sensors and signal transducers. Here we ask whether the $H_2O_2$ sensing role of Prx can be exploited to develop probes that allow to monitor intracellular $H_2O_2$ levels with unprecedented sensitivity. Indeed, simple gel shift assays visualizing the oxidation of endogenous 2-Cys peroxiredoxins have already been used to detect subtle changes in intracellular $H_2O_2$ concentration. The challenge however is to create a genetically encoded probe that offers real-time measurements of $H_2O_2$ levels in intact cells via the Prx oxidation state. We discuss potential design strategies for Prx-based probes based on either the redoxsensitive fluorophore roGFP or the conformation-sensitive fluorophore cpYFP. Furthermore, we outline the structural and chemical complexities which need to be addressed when using Prx as a sensing moiety for $H_2O_2$ probes. We suggest experimental strategies to investigate the influence of these complexities on probe behavior. In doing so, we hope to stimulate the development of Prx-based probes which may spearhead the further study of cellular $H_2O_2$ homeostasis and Prx signaling.

Bone Marrow Toxicity Caused by Estrogen Toxicity in a Yorkshire Terrier with Leydig Cell Tumor

  • Kim, Yoon-Hee;Ko, Kyu-Ryeon;No, Mi-Young;Kim, Jae-Hoon;Choi, Ul-Soo
    • Journal of Veterinary Clinics
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    • v.36 no.2
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    • pp.129-131
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    • 2019
  • A 15-year-old intact Yorkshire terrier was presented with anorexia, lethargy, and a pale mucous membrane. A physical examination one year ago revealed right testis mass and subcutaneous petechia. Blood work revealed severe thrombocytopenia and mild anemia, and no abnormalities were found in serum chemistry or ultrasonography. The preoperative serum estrogen concentration was moderately elevated. The enlarged testis was surgically removed. A well-encapsulated mass composed of polyhedral or round with abundant eosinophilic cytoplasm containing fine granular or vacuolation were found in a histological examination of the removed tissue. The nuclei of tumor cells were round, and mitotic figures were low but neoplastic cells showed a mild invasive tendency to adjacent tissues with contained neoplastic cell emboli in one lymphatic lumen. A diagnosis of a malignant Leydig cell tumor was made. The patient recovered from surgery uneventfully, but his condition worsened despite repeated transfusions and supportive therapy, and he was euthanized according to the owner's decision. Leydig cell tumor should be included in estrogen toxicity associated with testicular mass.

Antimelanogenesis Effects of Fungal Exopolysaccharides Prepared from Submerged Culture of Fomitopsis castanea Mycelia

  • Jin, Juhui;Nguyen, Thi Thanh Hanh;Kim, Changmu;Kim, Doman
    • Journal of Microbiology and Biotechnology
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    • v.29 no.8
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    • pp.1204-1211
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    • 2019
  • Fungal exopolysaccharides are important natural products having diverse biological functions. In this study, exopolysaccharides from Fomitopsis castanea mycelia (FEPS) were prepared, and the highest mushroom tyrosinase inhibitory activity was found. FEPS were prepared from cultivation broth by ethanol precipitation method. The extraction yield and protein concentration of FEPS were 213.1 mg/l and 0.03%, respectively. FEPS inhibited mushroom tyrosinase with the half maximal inhibitory concentration ($IC_{50}$) of 16.5 mg/ml and dose-dependently inhibited cellular tyrosinase activity (63.9% at $50{\mu}g/ml$, and 83.3% at $100{\mu}g/ml$) in the cell-free extract of SK-MEL-5 human melanoma cell and ${\alpha}$-melanocyte-stimulating hormone (${\alpha}-MSH$)-stimulated melanin formation in intact SK-MEL-5 human melanoma cell. The $IC_{50}$ of FEPS against NO production from RAW264.7 macrophage cells was $42.8{\pm}0.64{\mu}g/ml$. By in vivo study using a zebrafish model, exposure of FEPS at $400{\mu}g/ml$ to dechorionated zebrafish embryos for 18 h decreased the pigment density, compared to that without FEPS-treated control.

Alleviation of imiquimod-induced psoriasis-like symptoms in Rorα-deficient mouse skin

  • Koog Chan Park;Jiwon Kim;Aram Lee;Jong-Seok Lim;Keun Il Kim
    • BMB Reports
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    • v.56 no.5
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    • pp.296-301
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    • 2023
  • Retinoic acid receptor-related orphan receptor α (RORα) plays a vital role in various physiological processes, including metabolism, cancer, circadian rhythm, cerebellar development, and inflammation. Although RORα is expressed in the skin, its role in skin physiology remains poorly elucidated. Herein, Rorα was expressed in the basal and suprabasal layers of the epidermis; however, keratinocyte-specific Rorα deletion did not impact normal epidermal formation. Under pathophysiological conditions, Rorα-deficient mice exhibited alleviated psoriasis-like symptoms, including relatively intact epidermal stratification, reduced keratinocyte hyperproliferation, and low-level expression of inflammatory cytokines in keratinocytes. Unexpectedly, the splenic population of Th17 cells was significantly lower in keratinocyte-specific RORα deficient mice than in the control. Additionally, Rorα-deficiency reduced imiquimod-induced activation of nuclear factor-κB and STAT3 in keratinocytes. Therefore, we expect that RORα inhibitors act on immune cells and keratinocytes to suppress the onset and progression of psoriasis.

Insulin Resistance Reduces Sensitivity to Cis-Platinum and Promotes Adhesion, Migration and Invasion in HepG2 Cells

  • Li, Lin-Jing;Li, Guang-Di;Wei, Hu-Lai;Chen, Jing;Liu, Yu-Mei;Li, Fei;Xie, Bei;Wang, Bei;Li, Cai-Li
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.3123-3128
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    • 2014
  • The liver is normally the major site of glucose metabolism in intact organisms and the most important target organ for the action of insulin. It has been widely accepted that insulin resistance (IR) is closely associated with postoperative recurrence of hepatocellular carcinoma (HCC). However, the relationship between IR and drug resistance in liver cancer cells is unclear. In the present study, IR was induced in HepG2 cells via incubation with a high concentration of insulin. Once the insulin-resistant cell line was established, the stability of HepG2/IR cells was further tested via incubation in insulin-free medium for another 72h. Afterwards, the biological effects of insulin resistance on adhesion, migration, invasion and sensitivity to cis-platinum (DDP) of cells were determined. The results indicated that glucose consumption was reduced in insulin-resistant cells. In addition, the expression of the insulin receptor and glucose transportor-2 was downregulated. Furthermore, HepG2/IR cells displayed markedly enhanced adhesion, migration, and invasion. Most importantly, these cells exhibited a lower sensitivity to DDP. By contrast, HepG2/IR cells exhibited decreased adhesion and invasion after treatment with the insulin sensitizer pioglitazone hydrochloride. The results suggest that IR is closely related to drug resistance as well as adhesion, migration, and invasion in HepG2 cells. These findings may help explain the clinical observation of limited efficacy for chemotherapy on a background of IR, which promotes the invasion and migration of cancer cells.

Cytologic Aspect of Fibrous Osteodystrophy in a Juvenile Siberian Husky (어린 Siberian Husky 견의 섬유성 골형성장애의 세포학적 고찰 증례)

  • Jee, Hyang;Choi, Ul-Soo;Latouche, Jean-Sebastien;Bang, Dong-Ha;Kim, Dae-Yong;Hwang, Cheol-Yong;Youn, Hwa-Young
    • Journal of Veterinary Clinics
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    • v.26 no.1
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    • pp.54-57
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    • 2009
  • A 5-month-old intact female Siberian Husky dog was presented for evaluation of severely enlarged maxilla. Abnormalities in CBC, serum chemistry and urinalysis indicated purulent inflammation and renal failure. Cytologic examination of the swollen maxilla showed a mixed population of multinucleated giant cells and round to polygonal to spindle shaped cells either individualized or aggregated. Both type of cells showed moderate anisokaryosis, and anisocytosis, prominent nucleolus or multiple nucleoli, and coarse chromatin. On histopathology maxilla and turbinate were diffusely expanded and replaced by variably dense fibrous connective tissue, and the kidneys showed changes consistent with renal dysplasia. Based on these findings, the diagnosis of fibrous osteodystrophy due to renal dysplasia and fibrosis was made. Despite the supportive care, the dog continued to decline and was euthanized.

Effect of duration from lingual nerve injury to undergoing microneurosurgery on improving sensory and taste functions: retrospective study

  • Nakanishi, Takashi;Yamamoto, Yuta;Tanioka, Kensuke;Shintani, Yukari;Tojyo, Itaru;Fujita, Shigeyuki
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.41
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    • pp.61.1-61.8
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    • 2019
  • Background: The prognosis of recovery following microneurosurgery for injured lingual nerves varies among individual cases. This study aimed to investigate if recovery ratios of sensory and taste functions are improved by the microneurosurgery within 6 months after lingual nerve injury. Methods: We retrospectively assessed 70 patients who underwent microneurosurgery at the Wakayama Medical University Hospital for lingual nerve injuries between July 2004 and December 2016. Sensory and taste functions in lingual nerves were preoperatively evaluated using a static two-point discrimination test, an intact superficial pain/tactile sensation test, and a taste discrimination test. They were evaluated again at 12 and at 24 months postoperatively. The abundance ratio of Schwann cells in the excised traumatic neuromas was analyzed with ImageJ software following immunohistochemistry with anti S-100β antibody. Results: In early cases (microneurosurgery within 6 months after the injury), recovery ratios of sensory and taste functions were not significantly different at 24 months after microneurosurgery compared with later cases (microneurosurgery more than 6 months after the injury). Meanwhile, the ratio of patients with taste recovery within 12 months after microneurosurgery was significantly decreased in late cases compared with early cases. The abundance ratio of Schwann cells in traumatic neuroma was also significantly lower in later cases. Conclusion: Microneurosurgery more than 6 months after lingual nerve injury did not lead to decreased recovery ratio of sensory and taste functions, but it did lead to prolonged recovery of taste. This delay may be associated with a decrease in the abundance ratio of Schwann cells in traumatic neuromas.

Functional characterization of the distal long arm of laminin: Characterization of Cell- and heparin binding activities

  • Sung, Uhna;O′Rear, Julian J.;Yurchenco, Peter D.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.10a
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    • pp.107-113
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    • 1995
  • Basement membrane laminin is a multidomain glycoprotein that interacts with itself, heparin and cells. The distal long arm plays major cell and heparin interactive roles. The long arm consists of three subunits (A, B1, B2) joined in a coiled-coil rod attached to a terminal A chain globule (G). The globule is in turn subdivided into five subdomains (Gl-5). In order to analyze the functions of this region, recombinant G domains (rG, rAiG, rG5, rGΔ2980-3028) were expressed in Sf9 insect cells using a baculovirus expression vector. A hybrid molecule (B-rAiG), consisting of recombinant A chain(rAiG) and the authentic B chains (E8-B)was assembled in vitro. The intercalation of rAiG into E8-B chains suppressed a heparin binding activity identified in subdomain Gl-2. By the peptide napping and ligand blotting, the relative affinity of each subeomain to heparin was assigned as Gl> G2= G4> G5> G3, such that G1 bound strongly and G3 not at all. The active heparin binding site of G domain in intact laminin appears to be located in G4 and proximal G5. Cell binding was examined using fibrosarcoma Cells. Cells adhered to E8, B-rAiG, rAiG and rG, did not bind on denatured substrates, poorly bound to the mixture of E8-B and rG. Anti-${\alpha}$6 and anti-${\beta}$1 integrin subunit separately blocked cell adhesion on E8 and B-rAiG, but not on rAiG. Heparin inhibited cell adhesion on rAiG, partially on B-rAiG, and not on E8. In conclusion, 1) There are active and cryptic cell and heparin binding activities in G domain. 2) Triple-helix assembly inactivates cell and heparin binding activities and restores u6131 dependent cell binding activities.

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Pectic-Oligoshaccharides from Apples Induce Apoptosis and Cell Cycle Arrest in MDA-MB-231 Cells, a Model of Human Breast Cancer

  • Delphi, Ladan;Sepehri, Houri;Khorramizadeh, Mohammad Reza;Mansoori, Fatemeh
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.13
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    • pp.5265-5271
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    • 2015
  • Background: The effects of plant products on cancer cells has become a field of major importance. Many substancesmay induce apoptosis in anti-cancer treatment. Pectins, a family of complex polysaccharides, and their degradation products may for exasmple exert apoptotic effects in cancer cells. Apples and citrus fruits are the main sources of pectin which can be applied for anti-cancer research. The present study concerned an intact form of pectic-oligoshaccharide named pectic acid (poly galactronic acid). Materials and Methods: Inhibition of cell proliferation assays (MTT), light microscopy, fluorescence microscopy (acridin orange/ethidium bromide), DNA fragmentation tests, cell cycle analysis, annexin PI and Western blotting methods were applied to evaluate apoptosis. Results: The results indicated that pectic acid inhibited cell growth and reduced cell attachment after 24h incubation. This did not appear to be due to necrosis, since morphological features of apoptosis were detected with AO/EB staining and cell cycling was blocked in the sub-G1 phase. Annexin/PI and DNA fragmentation findings indicated that apoptosis frequency increased after 24h incubation with pectic acid. In addition, the data showed pectic acid induced caspase-dependent apoptosis. Conclusions: These data indicate that apple pectic acid without any modification could trigger apoptosis in MDA-MB-231 human breast cancer cells and has potential to improve cancer treatment as a natural product.

Initial Subcellular Responses of Susceptible and Resistant Soybeans Infected with the Soybean Cyst Nematode

  • Kim, Young Ho;Kim, Kyung Soo;Riggs, Robert D.
    • The Plant Pathology Journal
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    • v.28 no.4
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    • pp.401-408
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    • 2012
  • Initial subcellular responses in susceptible (PI 274420) and resistant (cv. Hartwig) soybeans infected with the soybean cyst nematode (SCN) were examined 2 and 4 days after inoculation (DAI). Subcellular features common to both soybeans at 2 DAI included hypertrophied initial syncytial cells (ISCs) and syncytium-component cells (SCs) with a dense cytoplasm containing proliferated rough and smooth endoplasmic reticulum (RER and SER), a hypertrophied nucleolus, and reduced vacuoles, suggesting that the nematode-infected cells were dedifferentiated. In the resistant soybean, a striking initial subcellular difference from the susceptible soybean was the dilation of the RER, indicating ER dysfunction and leading to cell death. This disturbed nematode feeding, as evidenced by disrupted feeding tubes. In PI 274420, the ISC cytoplasm was depleted, with the exception of ER membranes, at 4 DAI, while the SC cytoplasm was dense with proliferation of starch-containing plastids around multiple nuclei that might be derived from the congregation of nuclei in the neighboring SCs and in part by nuclear division without cytokinesis. In cv. Hartwig, syncytia were necrotized with secondary cell wall thickening outside the plasma membrane and an extremely dense cytoplasm containing a nucleus with an electron-lucent nucleolus, accompanied by the proliferation of closely stacked parallel RER and ribosomes. These results suggest that syncytia develop continuously in PI 274420 to produce and store nutritional substances in SCs, providing for the nematode through ISC until maturation, but in cv. Hartwig, syncytia degenerate early due to excessive metabolism, blocking nematode feeding and cytoplasmic connections with adjacent intact cells.