• Title/Summary/Keyword: Membrane protrusion

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v-Crk Induces Rac-dependent Membrane Ruffling and Cell Migration in CAS-deficient Embryonic Fibroblasts

  • Sung, Bong Hwan;Yeo, Myoung Gu;Oh, Hye Jin;Song, Woo Keun
    • Molecules and Cells
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    • v.25 no.1
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    • pp.131-137
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    • 2008
  • Crk-associated substrate (CAS) is a focal adhesion protein that is involved in integrin signaling and cell migration. CAS deficiency reduces the migration and spreading of cells, both of which are processes mediated by Rac activation. We examined the functions of v-Crk, the oncogene product of the CT10 virus p47gag-crk, which affects cell migration and spreading, membrane ruffling, and Rac activation in CAS-deficient mouse embryonic fibroblasts (CAS-/- MEFs). CAS-/- MEFs showed less spreading than did CAS+/+ MEFs, but spreading was recovered in mutant cells that expressed v-Crk (CAS-/-v-Crk MEF). We observed that the reduction in spreading was linked to the formation of membrane ruffles, which were accompanied by Rac activation. In CAS-/- MEFs, Rac activity was significantly reduced, and Rac was not localized to the membrane. In contrast, Rac was active and localized to the membrane in CAS-/-v-Crk MEFs. Lamellipodia protrusion and ruffle retraction velocities were both reduced in CAS-/- MEFs, but not in CAS-/-v-Crk MEFs. We also found that microinjection of anti-gag antibodies inhibited the migration of CAS-/-v-Crk MEFs. These findings indicate that v-Crk controls cell migration and membrane dynamics by activating Rac in CAS-deficient MEFs.

PROM1-mediated cell signal transduction in cancer stem cells and hepatocytes

  • Myeong-Suk Bahn;Young-Gyu Ko
    • BMB Reports
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    • v.56 no.2
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    • pp.65-70
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    • 2023
  • Prominin-1 (PROM1), also called CD133, is a penta-span transmembrane protein that is localized in membrane protrusions, such as microvilli and filopodia. It is known to be expressed in cancer stem cells and various progenitor cells of bone marrow, liver, kidney, and intestine. Accumulating evidence has revealed that PROM1 has multiple functions in various organs, such as eye, tooth, peripheral nerve, and liver, associating with various molecular protein partners. PROM1 regulates PKA-induced gluconeogenesis, TGFβ-induced fibrosis, and IL-6-induced regeneration in the liver, associating with Radixin, SMAD7, and GP130, respectively. In addition, PROM1 is necessary to maintain cancer stem cell properties by activating PI3K and β-Catenin. PROM1-deficienct mice also show distinct phenotypes in eyes, brain, peripheral nerves, and tooth. Here, we discuss recent findings of PROM1-mediated signal transduction.

Numerical study of fluid behavior on protruding shapes within the inlet part of pressurized membrane module using computational fluid dynamics

  • Choi, Changkyoo;Lee, Chulmin;Park, No-Suk;Kim, In S.
    • Environmental Engineering Research
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    • v.25 no.4
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    • pp.498-505
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    • 2020
  • This study analyzes the velocity and pressure incurred by protruding shapes installed within the inlet part of a pressurized membrane module during operation to determine the fluid flow distribution. In this paper, to find the flow distribution within a module, it investigates the velocity and pressure values at cross-sectional and outlet planes, and 9 sections classified on outlet plane using computational fluid dynamics. From the Reynolds number (Re), the fluid flow was estimated to be turbulent when the Re exceeded 4,000. In the vertical cross-sectional plane, shape 4 and 6 (round-type protrusion) showed the relatively high velocity of 0.535 m/s and 0.558 m/s, respectively, indicating a uniform flow distribution. From the velocity and pressure at the outlet, shape 4 also displayed a relatively uniform fluid velocity and pressure, indicating that fluid from the inlet rapidly and uniformly reached the outlet, however, from detailed data of velocity, pressure and flowrate obtained from 9 sections at the outlet, shape 6 revealed the low standard deviations for each section. Therefore, shape 6 was deemed to induce the ideal flow, since it maintained a uniform pressure, velocity and flowrate distribution.

The Healing of Exposed Implant Surfaces in A Maxillary Sinus Cavity (상악동 내 노출된 임플란트의 치유양상)

  • Lee, Seoung-Ho;Choi, Byung-Ho;Zhu, Shi-Jiang;Jung, Jae-Hyung;You, Tae-Min;Lee, Hyeon-Jung;Li, Jingxu;Huh, Jin-Young
    • Journal of Periodontal and Implant Science
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    • v.35 no.4
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    • pp.1073-1079
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    • 2005
  • 1. Objective. The aim of this study was to investigate whether dental implant exposure to the maxillary sinus cavity increases the risk of maxillary sinus complications. 2. Study design. An implant was placed bilaterally in the maxillary sinus of eight adult female mongrel dogs in a way that it penetrated the bone and mucous membrane of the maxillary sinus floor to the extent of 2 mm, 4 mm, or 8 mm. The implants were left in place for six months. 3. Results. Radiographic and histologic examinations did not show any signs of pathologic findings in the maxillary sinus of the eight dogs. 4. Conclusion. This study indicates that implant protrusion into the maxillary sinus cavity is not related to the development of sinus complications.

Fine Needle Aspiration Cytology of Peripheral T Cell Lymphoma, Lymphoepithelioid Cell Type - Report of A Case Mimicking Tuberculous Lymphadenitis - (림프유상피형 말초 T세포 림프종의 세침흡인 세포학적 소견 - 결핵성 림프절염과 감별이 어려웠던 1예 -)

  • Park, Ho-Sung;Hong, Jong-Myung;Chung, Myoung-Ja;Moon, Woo-Sung
    • The Korean Journal of Cytopathology
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    • v.10 no.2
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    • pp.185-189
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    • 1999
  • The diagnosis of peripheral T cell lymphoma is difficult due to the varying size and shape of the neoplastic lymphoid cells and the frequent admixture of nonneoplastic mature lymphyocytes, histiocytes, eosinophils, and plasma cells. We report a case of peripheral T cell lymphoma, lymphoepithelioid ceil type, which was difficult to differentiate from tuberculous lymphadenitis due to the aggregates of epithelioid histlocytes mimicking granuloma and the past history of pulmonary tuberculosis. Fine needle aspiration cytology of the inguinal lymph node in a 63-year-old male was characterized by hypercellular aspirates composed of a mixture of small and intermediate-size lymphoid cells and large lymphoid cells with background of confluent epithelioid histiocytes. The neoplastic lymphocytes demonstrated significant nuclear irregularity with protrusion and indentations of the nuclear membrane, prominent nucleoli, and frequent mitotic figures. The diagnosis of peripheral T cell lymphoma was confirmed by histological and immunohistochemical studios.

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Mechanisms of Weight Control by Primary Cilia

  • Lee, Chan Hee;Kang, Gil Myoung;Kim, Min-Seon
    • Molecules and Cells
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    • v.45 no.4
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    • pp.169-176
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    • 2022
  • A primary cilium, a hair-like protrusion of the plasma membrane, is a pivotal organelle for sensing external environmental signals and transducing intracellular signaling. An interesting linkage between cilia and obesity has been revealed by studies of the human genetic ciliopathies Bardet-Biedl syndrome and Alström syndrome, in which obesity is a principal manifestation. Mouse models of cell type-specific cilia dysgenesis have subsequently demonstrated that ciliary defects restricted to specific hypothalamic neurons are sufficient to induce obesity and hyperphagia. A potential mechanism underlying hypothalamic neuron cilia-related obesity is impaired ciliary localization of G protein-coupled receptors involved in the regulation of appetite and energy metabolism. A well-studied example of this is melanocortin 4 receptor (MC4R), mutations in which are the most common cause of human monogenic obesity. In the paraventricular hypothalamus neurons, a blockade of ciliary trafficking of MC4R as well as its downstream ciliary signaling leads to hyperphagia and weight gain. Another potential mechanism is reduced leptin signaling in hypothalamic neurons with defective cilia. Leptin receptors traffic to the periciliary area upon leptin stimulation. Moreover, defects in cilia formation hamper leptin signaling and actions in both developing and differentiated hypothalamic neurons. The list of obesity-linked ciliary proteins is expending and this supports a tight association between cilia and obesity. This article provides a brief review on the mechanism of how ciliary defects in hypothalamic neurons facilitate obesity.

Acupuncture Treatment in Feline Horner's Syndrome: Case Report (고양이 Horner's syndrome에 대한 침치료(針治療) 증예보고(症例報告))

  • Hsu, Chin-Yuan;Hsu, Chin-ling;Hsu, Chin-Hwang;Liao, Jim-Cai;Chueh, Hao-Jen;Cheng, Han-Wen;Jun, Hyeong-Kyou;Kim, Duck-Hwan
    • Journal of Veterinary Clinics
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    • v.24 no.2
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    • pp.214-217
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    • 2007
  • A about 2-month- old, mixed female cat was referred to Yeon Chang Veterinaly Clinic in Taiwan. Because this patient was wandering cat, precise history was not blown. At first admission, miosis, ptosis and protrusion of the nictitating membrane was observed in the right sided eye, and also slight miosis was found in the left sided eye. The patient was diagnosed into feline HS. Oculo-AP and injection-AP with dexamethasone were applied to this patient. Oculo-AP at Shang Jiao regions of both eyes was done for 10 minutes. In addition, injection-AP with dexamethasone (0.2 ml/acupoint) at BL01-Jing Ming, BL02-Zan Zhu and ST01-Cheng Qi. After AP treatment, prolapse of the nictitating membrane was amazingly disappeared and pupil was dilatated at session 1. Ocular findings at session 2 (one day after session 1) were maintained with nearly normal state. Accordingly, the present patient was a case with feline HS that showed favorable therapeutic effect by AP treatment.

Effects of PLCE1 Gene Silencing by RNA Interference on Cell Cycling and Apoptosis in Esophageal Carcinoma Cells

  • Zhao, Li;Wei, Zi-Bai;Yang, Chang-Qing;Chen, Jing-Jing;Li, Dan;Ji, Ai-Fang;Ma, Liang
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5437-5442
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    • 2014
  • Esophageal squamous cell carcinoma (ESCC) is one of the most malignancies with a poor prognosis. The phospholipase $C{\varepsilon}$ gene (PLCE1) encodes a novel ras-related protein effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion. However, molecular mechanisms pertinent to ESCC are unclear. We therefore designed PLCE1-special small interfering RNA and transfected to esophageal squamous cell (EC) 9706 cells to investigat the effects of PLCE1 gene silencing on the cell cycle and apoptosis of ESCC and indicate its important role in the development of ESCC. Esophageal cancer tissue specimens and normal esophageal mucosa were obtained and assayed by immunohistochemical staining to confirm overexpression of PLCE1 in neoplasias. Fluorescence microscopy was used to examine transfection efficiency, while the result of PLCE1 silencing was examined by reverse transcription (RT-PCR). Flow cytometry and annexin V apoptosis assays were used to assess the cell cycle and apoptosis, respectively. Expression of cyclin D1 and caspase-3 was detected by Western-blotting. The level of PLCE1 protein in esophageal cancer tissue was significantly higher than that in normal tissue. After transfection, the expression of PLCE1 mRNA in EC 9706 was significantly reduced, compared with the control group. Furthermore, flow cytometry results suggested that the PLCE1 gene silencing arrested the cell cycle in the G0/G1 phase; apoptosis was significantly higher than in the negative control group and mock group. PLCE1 gene silencing by RNAi resulted in decreased expression of cyclin D1 and increased expression of caspase-3. Our study suggests that PLCE1 may be an oncogene and play an important role in esophageal carcinogenesis through regulating proteins which control cell cycling and apoptosis.

Independent Prognostic Value of the Fascin Expression in Patients with Esophageal Cancer (식도암에 있어서 Fascin의 발현과 예후와의 상관관계에 대한 연구)

  • Choi, Pill-Jo;Jeong, Sang-Seok;Bang, Jung-Heui;Cho, Kwang-Jo;Woo, Jong-Soo;Roh, Mee-Sook
    • Journal of Chest Surgery
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    • v.41 no.1
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    • pp.74-81
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    • 2008
  • Background: Fascin is an actin-bundling protein that induces membrane protrusions and it increases cell motility in various transformed cells. Esophageal cancer is one of the most lethal malignancies, and it exhibits extensive local invasion or frequent regional lymph node metastasis even after curative surgery. We investigate the expression of fascin by performing immunohistochemistry to evaluate the clinical characteristics and prognostic significance of its expression in esophageal cancer patients. Material and Method: Immunochemistry for fascin was performed on 76 tumor samples from 76 patients who underwent esophageal cancer operations. The expression levels of fascin in the 76 esophageal cancer tissues were compared with those in the corresponding normal esophageal epithelium. The fascin-positive samples were defined as those showing more than 75% of fascin-positive cells. Result: Overall, a fascin positive expression was detected in 39 (51.3%) out of the total 76 cases. The tumors with positive fascin expression tended to more frequently show a higher stage (p=0.030), and a higher T-factor (p=0.031). The prognosis of the fascin negative group was significantly better than that of the fascin positive group (p=0.004). Multivariate analysis revealed that lymphovascular invasion and the fascin expression were independent prognostic factors. Conclusion: Fascin was expressed in 513% of the esophageal cancer tissues and a positive expression of fascin was associated with more advanced tumor progression and recurrence. Our study suggests that the fascin expression may be an independent prognostic factor for an unfavorable clinical course few those patients suffering with esophageal cancer.