• Title/Summary/Keyword: Murine

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EXPRESSION PATTERN OF RUNX2 IN MURINE TOOTH DEVELOPMENT (Mouse의 치아 발육시 Runx2의 발현 양상)

  • Kim, Tae-Wan;Ryoo, Hyun-Mo;Nam, Soon-Hyeun;Kim, Young-Jin;Kim, Hyun-Jung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.4
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    • pp.651-658
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    • 2004
  • Runx2 is a transcription factor in homologous with Drosophila runt gene and it is essential for bone formation during embryogenesis and a critical gene for osteoblast differentiation and osteoblast function. Runx2-haploinsufficency causes cleidocranial dysplasia (CCD). CCD is an autosomal-dominant inherited disorder characterized by hypoplastic clevicle and delayed ossification in fontanelles and wormian bones. Dental defects are possibly shown to CCD patients : multiple supernumerary teeth, irregular and compressed permanent tooth crowns, hypoplastic and hypomineralized defects in enamel and dentin, an excess of epithelial root remnants, the absence of cellular cementum, and abnormally shaped roots. In addition, delayed eruption of the secondary dentition is a constant finding. The aim of this study is to evaluate the role of Runx2 in the tooth development and eruption through analyzing the expression pattern of Runx2 by in situ hybridization during crown (late bell stage) and root formation of tooth, using postnatal day 1, 4, 7, 14 and 21 mice mandibular molar teeth. mRNA of Runx2-full length is expressed in dental follicle and surrounding tissue at postnatal day1 and 4. At postnatal day 7, it is expressed in ameloblasts of occlusal surface of enamel and bone area surrounding the tooth. In comparison with previous stage, at postnatal day 14, it is expressed in ameloblasts of proximal surface of enamel. At postnatal day 21 it's expression is observed only in bone area. mRNA of Runx2-typeII is not expressed. At postnatal day 1 and 7. At postnatal day 14 and 21, it's expression is observed in the bone area. In this study, we suggest that Runx2 have a relation of ameloblasts differentiation and an important role to tooth eruption made by dental follicle during intraosseous eruption stage. Also we can confirm that Runx2 has a role to bone formation.

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Effect of High Purity β-1.3/1.6-Glucan on Macrophages, Natural Killer Cells, and T Cell-Mediated Factors (고순도 β-1.3/1.6-Glucan이 대식세포 및 자연살해세포와 T 세포면역계에 미치는 영향)

  • Kwon, Hanol;Lee, Minhee;Park, Soo-Jeung;Lee, Dasom;Kim, Hyesook;Lee, Jeongmin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.11
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    • pp.1564-1570
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    • 2016
  • The present study investigated the immunomodulatory effects of high-purity ${\beta}$-1.3/1.6-glucan on macrophages, natural killer (NK) cells, and T cell-mediated factors. Effect of high-purity ${\beta}$-1.3/1.6-glucan on cytotoxicity in macrophages was investigated. Using macrophages, cytotoxicity of high-purity ${\beta}$-1.3/1.6-glucan was evaluated by MTT assay. We treated high-purity ${\beta}$-1.3/1.6-glucan at concentrations of 10, 50, 100, 150, 200, and $250{\mu}g/mL$ in macrophages. High-purity ${\beta}$-1.3/1.6-glucan did not affect macrophage viability. Phagocytic activity was assessed using zymosan. Activity of high-purity ${\beta}$-1.3/1.6-glucan on macrophages significantly increased as compared with zymosan. We treated high-purity ${\beta}$-1.3/1.6-glucan to murine NK cells co-incubated with YAC-1 cells. High-purity ${\beta}$-1.3/1.6-glucan resulted in significantly increased activity of NK cells as compared with the control. In addition, treatment of macrophages with high-purity ${\beta}$-1.3/1.6-glucan resulted in significantly increased activity of T cell-mediated cytokine (IL-2, IL-12, $IFN-{\gamma}$, and $TNF-{\alpha}$) levels and CD4+/CD8+ T cells as compared with the control. In conclusion, high-purity ${\beta}$-1.3/1.6-glucan could enhance the immune response through activation of macrophages, NK cells, and T cell-mediated factors.

The Morphologic Changes by Immunosuppression after Heterotopic Transplantation of the Murine Cryopreserved Trachea: An Animal Model for Obliterative Bronchiolitis (이소 이식된 쥐 기관의 면역억제 및 초냉동 보관에 의한 형태학적 변화: 폐색성 모세기관지염의 연구를 위한 동물 실험 모델)

  • 이창하;성숙환;오미혜
    • Journal of Chest Surgery
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    • v.32 no.3
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    • pp.215-223
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    • 1999
  • Background: The replacement of the narrowed long-segment trachea with various prosthetic materials or tissue grafts remains a difficult and unsolved surgical problem. Homologous cryopreserved tracheal transplantation has been considered to treat the irreversibly-damaged organs, such as in the lung or heart transplantation and also to overcome the limited supply of donor organs. We examined the morphological changes and the immunosuppressive effects of the cryopreserved trachea after the heterotopic transplantation in the rats. Material and Method: Sixty tracheal segments harvested from 30 donor Wistar rats were heterotopically implanted into the peritoneal cavity of 20 recipient Wistar rats and 40 Sprague Dawley rats. The 60 recipient rats were divided into 6 groups(10 rats/ group). In groups I, II, and III, 30 tracheal segments were implanted immediately after the harvesting and in groups IV, V, and VI, the segments were implanted 28 days after the cryopreservation. Groups I and IV were Wistar syngeneic controls. Groups II and V were Sprague Dawley recipients receiving no immunosuppression and Groups III and VI, were Sprague Dawley recipients receiving immunosuppressive agents. At 28 days all rats were sacrificed and the tracheal segments were evaluated grossly and histologically. Result: Immunosuppression of the tracheal segments had a significant influence on the changes of the tracheal lumen and tracheal epithelial cells, irrespective of the cryopreservation of the trachea(p<0.001). In groups III and VI receiving immunosuppressive agents, the tracheal lumen was patent and the normal epithelial cells were observed, however in the other groups not receiving the immunosuppressive agents, there were almost luminal obliteration by the proliferation of the fibrous tissues and a loss of the epithelial cells, the findings were similar to those in the case of obliterative bronchiolitis after a lung and a heart-lung transplantation. Conclusion: With the appropriate immunosuppressive agents, the lumen and the respiratory epithelium of the transplanted tracheal segment were well preserved, even after the cryopreservation of the tracheal segment, which shows the possibility of the long-term preservation and homologous transplantation of the trachea. But fibroproliferative obliteration of the tracheal lumen and the loss of the normal respiratory epithelial cells, characteristic findings of obliterative bronchiolitis, were observed in the groups without the immunosuppression. This experiment using the rat trachea may be useful in studying the pathogenesis, treatment, and prevention of obliterative bronchiolitis after a lung and a heart-lung transplantation.

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Intratumoral Administration of Dendritic Cells Combined with Hyperthermia Induces Both Local and Systemic Antitumor Effect in Murine Tumor Models (온열 요법 후 종양 내 주입한 수지상 세포의 국소 및 원격 항종양 효과)

  • Kwon Byung-Hyun;Kim Won-Taek;Kim Young-Kan;Kim Dong-Won
    • Radiation Oncology Journal
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    • v.24 no.1
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    • pp.51-57
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    • 2006
  • Puroose: We examined whether intratumoral (i.t.) administration of dendritic cells (DCs) into a treated tumor could induce local and systemic antitumor effects in a mouse tumor model. Methods and Materials: C57BL/6 mice were inoculated s.c. in the right and left thighs with MCA-102 fibrosarcoma cells on day 0 and on day 7, respectively. On day 7, the tumors (usually 6 mm in diameter) on the right thigh were heated by immersing the tumor-bearing leg in a circulating water bath at $43^{\circ}C$ for 30 min; thereafter, the immature DCs were i.t administered to the right thigh tumors. This immunization procedure was repeated on days 7, 14 and 21. The tumors in both the right and left thighs were measured every 7 days and the average sizes were determined by applying the following formula, tumor $size=0.5{\times}(length+width)$. Cytotoxicity assay was done to determine tumor-specific cytotoxic T-lymphocyte activity. Results: Hyperthermia induced apoptosis and heat shock proteins (HSPs) in tumor occurred maximally after 6 hr. For the local treated tumor, hyperthermia (HT) alone inhibited tumor growth compared with the untreated tumors (p<0.05), and furthermore, the i.t. administered DCs combined with hyperthermia (HT + DCs) additively inhibited tumor growth compared with HT alone (p<0.05). On the distant untreated tumor, HT alone significantly inhibited tumor growth (p<0.05), and also HT + DCs potently inhibited tumor growth (p<0.001); however, compared with HT alone, the difference was not statistically significant. In addition, HT + DCs induced strong cytotoxicity of the splenocytes against tumor cells compared to DCs or HT alone. Conclusion: HT + DCs induced apoptosis and increased the expression of HSPs, and so this induced a potent local and systemic antitumor response in tumor-bearing mice. This regimen may be beneficial for the treatment of human cancers.

Effects of Pinacidil, a Potassium-Channel Opener, on Biodistribution of Thallium-201 in Tumor-Bearing Mice ($K^+$ 통로개방제 Pinacidil이 종양이식 생쥐에서 Tl-201의 체내분포에 미치는 영향)

  • Lee, Jae-Tae;Chun, Kyung-Ah;Lee, Sang-Woo;Kang, Do-Young;Ahn, Byeong-Cheol;Jun, Soo-Han;Lee, Kyu-Bo;Ha, Jeoung-Hee
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.4
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    • pp.303-311
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    • 2000
  • Purpose: Thallium behaves similarly to potassium in vivo. Potassium channel opener (K-opener) opens ATP-sensitive $K^+$-channel located at cell membrane, resulting in potassium efflux from cytosol. We have previously reported that K-opener can alter biokinetics of Tl-201 in cultured cells and in vivo. Malignant tumor cells have high Na-K ATPase activity due to increased metabolic activities and dedifferentiation, and differential delineation of malignant tumor can be possible with Tl-201 imaging. K-opener may affect tumoral uptake of Tl-201 in vivo. To investigate the effects of pinacidil (one of the potent K-openers) on the localization of the tumor with Tl-201 chloride, we evaluated the changes in biodistribution of Tl-201 with pinacidil treatment in tumor-bearing mice. Materials and Methods: Baltic mice received subcutaneous implantation of murine breast cancer cells in the thigh and were used for biodistribution study 3 weeks later. $100{\mu}g$ of pinacidil dissolved in $200{\mu}l$ DMSO/PBS solution was injected intravenously via tail vein at 10 min after 185 KBq ($5{\mu}Ci$) Tl-201 injection. Percentage organ uptake and whole body retention ratio of Tl-201 were measured at various periods after injection, and values were compared between control and pinacidil-treated mice. Results: Pinacidil treatment resulted in mild decrease in blood levels of Tl-201, but renal uptakes were markedly decreased at 30-min, 1- and 2-hour, compared to control group. Hepatic, intestinal and muscular uptake were not different. Absolute percentage uptake and tumor to blood ratios of Tl-201 were lower in pinacidil treated mice than in the control group at all time points measured. Whole body retention ratio of Tl-201 was lower in pinacidil treated mice ($58{\pm}4%$ ), than in the control group ($67{\pm}3%$) at 24 hours after with injection of $100{\mu}g$ pinacidil. Conclusion: K-opener did not enhance, but rather decreased absolute tumoral uptake and tumor-to-blood ratios of Tl-201. Decreased whole body retention ratio and renal uptake were observed with pinacidil treatment in tumor-bearing mice.

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Involvement of TLR4-JNK/NF-κB signaling pathway in RAW264.7 cell activation of Protaetia brevitarsis seulensis larvae extracts (흰점박이꽃무지 유충 추출물의 RAW264.7 세포 활성화에서 TLR4-JNK/NF-κB 신호전달 경로의 관여)

  • Ju-Hwi Park;Jongbeom Chae;Joon Ha Lee;Dongyup Hahn;Ju-Ock Nam
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.447-454
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    • 2023
  • In the environment in which humans live, there are various antigens that invade the human body and interfere with humans leading a healthy life, so the immune system recognizes the antigen then removes them through a complex mechanism. Macrophages are widely distributed immune cells involved in the innate immune system, and produce various immune modulators such as inducible nitric oxide synthase-induced nitric oxide, cyclooxygenase-2 induced prostaglandin E2 and proinflammatory cytokines such as tumor necrosis factor-alpha. On the other hand, Protaetia brevitarsis seulensis larvae are a type of edible insect that have emerged as an alternative to the future food supply problem. The immuno-modulatory effect through the activation of murine macrophage RAW264.7 cell via mitogen-activated protein kinases (MAPKs)/nuclear factor-kappa B (NF-κB) signaling pathways has been reported. Based on this report, in this study, we confirmed how the expression of immune modulators induced by Protaetia brevitarsis seulensis larvae extracts in RAW264.7 cells was changed by treatment with pharmacological inhibitors of toll-like receptor 4 (TLR4), MAPKs and NF-κB signaling pathways. As a result, reduction of immune modulators was confirmed in the c-Jun N-terminal kinase (JNK) inhibitor treatment group and NF-κB inhibitor treatment group among the Protaetia brevitarsis seulensis larvae-treated RAW264.7 cell. Furthermore, in the TLR4 inhibitor-treated group, decreases in phosphorylation of JNK and NF-κB factors were confirmed in Protaetia brevitarsis seulensis larvae-treated RAW264.7 cell, as well as decreases in immune modulators. This results suggest that Protaetia brevitarsis seulensis larvae activates RAW264.7 cells by the engagement of TLR4-JNK/NF-κB signaling pathway.

A comparison study of the effects of loratadine-pharmacopuncture and loratadine-oral administration based on traditional Korean medicine theory on anaphylactic reaction in mice

  • Kim, Hyun-Min;Kim, Hyun-Min;Lee, Min-Jung;Cho, Min-Gi;Kang, Deok;Kim, Yu-Kyung;Kim, Changmin;Kang, Do-Hyun;Jeong, Si-Hwa;Ahn, Ik-Gyun;Hwang, Jun-Hyeok;Kim, Jae-Hyun;Lee, Hyun-Jin;Jang, Jun-Yeong;Park, Ho-Jung;Kang, Sin woo;Youm, Jieun;Baek, Seung-won;Kim, Eu Jin;Shin, Moon-Kou;Park, Chan;Son, Chang-Bin;Yim, Tae-Bin;Lim, Jung Hyun;Hong, Sung-eun;Choi, Jun-Hyuk;Kim, Jun-Dong;Yoon, Dong-ju;Lee, Dong-Min;Yu, Soo-Min;Hong, Ye-Im;Lee, Yeong-Seok;Koo, Bon-Cheol;Park, Hyoung-Jun;Uem, Chae-Yoon;Kim, Min-Jeong;Oh, Jayoung;Park, NamGyeong;Kim, Eun-Jong;Cho, Whi-Sung;Lee, Ho-Sung;Kim, Tae-oh;Yoon, Cheol;Kwon, Sung-Keun;Jeong, Dong-Hyeon;Lee, Changwon;Yu, Sang-Yeol;Shon, Chae-won;Jeon, Gyu-Ri;Hong, Yang-Seok;Moon, Phil-Dong
    • CELLMED
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    • v.8 no.1
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    • pp.5.1-5.4
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    • 2018
  • Pharmacopuncture, or herbal acupuncture, is a new form of therapy derived from combinations of two traditional therapeutic methods, herbal medicine and acupuncture therapy. To compare the efficacy between loratadine-pharmacopuncture (LP) and loratadine-oral administration (LO), the effect of loratadine was investigated in murine models. Anti-anaphylactic effects of loratadine treatments were investigated in compound 48/80-induced systemic anaphylactic reaction and passive cutaneous anaphylaxis (PCA). LP treatment significantly inhibited the compound 48/80-induced systemic anaphylactic reaction and PCA. The effect between LP and LO were on a similar level. These results indicate that LP can be used as an alternative method for LO in case of emergency.

Effect of Retrovirus Mediated TNF-$\alpha$ Gene Transfer to Tumor Necrosis Factor(TNF) Sensitive Tumor Cell Lines on Sensitivity to TNF (Retroviral Vector를 이용한 TNF-$\alpha$ 유전자의 이입이 암세포의 종양괴사인자(TNF) 감수성에 미치는 효과)

  • Oh, Yeon-Mok;Park, Kyeo-Yeong;Jung, Man-Pyo;Yoo, Chul-Gyu;Kim, Young-Whan;Han, Sung-Goo;Sim, Young-Soo;Han, Yong-Chol
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.2
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    • pp.87-96
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    • 1994
  • Background : Since tumor necrosis factor was discovered in 1975, TNF has been well known about its cytotoxic effect on tumor cells in vivo and in vitro. According to the recent improvement of molecular biological techinques, it is possible that exogenous TNF gene is transferred to tumor cells and is expressed in theirs. By virtue of TNF gene transfer, we have expected that TNF expressed in TNF-gene-transferred tumor cells would kill tumor cells in vivo without systemic side effect. The expected mechanisms in which antitumor effects of TNF expressed in TNF-gene-transferred tumor cells are working would be as followings. In the first mechanism, TNF expressed in TNF-gene-transferred tumor cells would kill tumor cells around(like homicide). In the second mechanism, TNF expressed in TNF-gene-transferred tumor cells would kill themselves(like suicide). In the third mechanism, TNF expressed in TNF-gene-transferred tumor cells would recruit immune effector cells and kill tumor cells indirectly. In the last mechanism, TNF expressed in TNF-gene-transferred tumor cells would augment cytokine such as interferon-$\gamma$ to kill tumor cells. Among these four mechanisms of antitumor effect, only the second mechanism has not been established yet. Therefore, to elucidate the second mechanism, We performed this study. Method : We transferred TNF-$\alpha$ gene to NCI-H2058, a human mesothelioma cell line and WEHI164, a murine fibrosarcoma cell line by using retroviral vector(pLT12SNTNF). And, We determined by using MTT assay whether TNF expressed in TNF-gene-transferred tumor cell lines would kill themselves like suicide or not. Then, if TNF-gene-transferred tumor cell lines would not suicide themselves, I would know more about the TNF sensitivity of TNF-gene-transferred tumor cell lines to exogenous TNF also by MTT assay. Result : NCI-H2058 and WEHI164 which were sensitive to TNF, became far less sensitive to endogenous and exogenous TNF after being transferred TNF-$\alpha$ gene to. Conclusion : TNF-gene-transfer to NCI-H2058 and WEHI164 gave them resistance to TNF.

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Evaluation of the Radioimmunotherapy Using I-131 labeled Vascular Endothelial Growth Factor Receptor2 Antibody in Melanoma Xenograft Murine Model (흑색종에서의 I-131표지 혈관내피세포성장인자 수용체2항체를 이용한 방사면역치료 평가)

  • Kim, Eun-Mi;Jeong, Hwan-Jeong;Park, Eun-Hye;Cheong, Su-Jin;Lee, Chang-Moon;Jang, Kyu-Yun;Kim, Dong-Wook;Lim, Seok-Tae;Sohn, Myung-Hee
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.4
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    • pp.307-313
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    • 2008
  • Purpose: Vascular endothelial growth factor (VEGF) and its receptor, fetal liver kinase 1 (Flk-1), play an important role in vascular permeability and tumor angiogenesis. The aim of this study is to evaluate the therapeutic efficacy of $^{131}I$ labeled anti-Flk-1 monoclonal antibody (DC101) on the growth of melanoma tumor, which is known to be very aggressive in vivo. Materials and Methods: Balb/c nude mice were injected subcutaneously with melanoma cells in the right flank. Tumors were allowed to grow up to $200-250\;mm^3$ in volume. Gamma camera imaging and biodistribution studies were performed to identify an uptake of $^{131}I$-DC101 in various organs. Mice with tumor were randomly divided into five groups (10 mice per group) and injected intravenously; control PBS (group 1), $^{131}I$-DC101 $50\;{\mu}g/mouse$ (group 2), non-labeled DC101 $50\;{\mu}g/mouse$ (group 3), $^{131}I$-DC101 $30\;{\mu}g/mouse$ (group 4) and $15\;{\mu}g/mouse$ (group 5) every 3 or 4 days for 20 days. Tumor volume was measured with caliper twice a week. Results: In gamma camera images, the uptake of $^{131}I$-DC101 into tumor and thyroid was increased with time. Biodistribution results showed that the radioactivity of blood and other major organ was gradually decreased with time whereas tumor uptake was increased up to 48 hr and then decreased. After 4th injection of $^{131}I$-DC101, tumor volume of group 2 and 4 was significantly smaller than that group 1. After 5th injection, the tumor volume of group 5 also significantly reduced. Conclusion: These results indicated that delivery of $^{131}I$ to tumor using FlK-1 antibody, DC101, effectively blocks tumor growth in aggressive melanoma xenograft model.

Roles of the Insulin-like Growth Factor System in the Reproductive Function;Uterine Connection (Insulin-like Growth Factor Systems의 생식기능에서의 역할;자궁편)

  • Lee, Chul-Young
    • Clinical and Experimental Reproductive Medicine
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    • v.23 no.3
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    • pp.247-268
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    • 1996
  • It has been known for a long time that gonadotropins and steroid hormones play a pivotal role in a series of reproductive biological phenomena including the maturation of ovarian follicles and oocytes, ovulation and implantation, maintenance of pregnancy and fetal growth & development, parturition and mammary development and lactation. Recent investigations, however, have elucidated that in addition to these classic hormones, multiple growth factors also are involved in these phenomena. Most growth factors in reproductive organs mediate the actions of gonadotropins and steroid hormones or synergize with them in an autocrine/paracrine manner. The insulin-like growth factor(IGF) system, which is one of the most actively investigated areas lately in the reproductive organs, has been found to have important roles in a wide gamut of reproductive phenomena. In the present communication, published literature pertaining to the intrauterine IGF system will be reviewed preceded by general information of the IGF system. The IGF family comprises of IGF-I & IGF-II ligands, two types of IGF receptors and six classes of IGF-binding proteins(IGFBPs) that are known to date. IGF-I and IGF-II peptides, which are structurally homologous to proinsulin, possess the insulin-like activity including the stimulatory effect of glucose and amino acid transport. Besides, IGFs as mitogens stimulate cell division, and also play a role in cellular differentiation and functions in a variety of cell lines. IGFs are expressed mainly in the liver and messenchymal cells, and act on almost all types of tissues in an autocrine/paracrine as well as endocrine mode. There are two types of IGF receptors. Type I IGF receptors, which are tyrosine kinase receptors having high-affinity for IGF-I and IGF-II, mediate almost all the IGF actions that are described above. Type II IGF receptors or IGF-II/mannose-6-phosphate receptors have two distinct binding sites; the IGF-II binding site exhibits a high affinity only for IGF-II. The principal role of the type II IGF receptor is to destroy IGF-II by targeting the ligand to the lysosome. IGFs in biological fluids are mostly bound to IGFBP. IGFBPs, in general, are IGF storage/carrier proteins or modulators of IGF actions; however, as for distinct roles for individual IGFBPs, only limited information is available. IGFBPs inhibit IGF actions under most in vitro situations, seemingly because affinities of IGFBPs for IGFs are greater than those of IGF receptors. How IGF is released from IGFBP to reach IGF receptors is not known; however, various IGFBP protease activities that are present in blood and interstitial fluids are believed to play an important role in the process of IGF release from the IGFBP. According to latest reports, there is evidence that under certain in vitro circumstances, IGFBP-1, -3, -5 have their own biological activities independent of the IGF. This may add another dimension of complexity of the already complicated IGF system. Messenger ribonucleic acids and proteins of the IGF family members are expressed in the uterine tissue and conceptus of the primates, rodents and farm animals to play important roles in growth and development of the uterus and fetus. Expression of the uterine IGF system is regulated by gonadal hormones and local regulatory substances with temporal and spatial specificities. Locally expressed IGFs and IGFBPs act on the uterine tissue in an autocrine/paracrine manner, or are secreted into the uterine lumen to participate in conceptus growth and development. Conceptus also expresses the IGF system beginning from the peri-implantation period. When an IGF family member is expressed in the conceptus, however, is determined by the presence or absence of maternally inherited mRNAs, genetic programming of the conceptus itself and an interaction with the maternal tissue. The site of IGF action also follows temporal (physiological status) and spatial specificities. These facts that expression of the IGF system is temporally and spatially regulated support indirectly a hypothesis that IGFs play a role in conceptus growth and development. Uterine and conceptus-derived IGFs stimulate cell division and differentiation, glucose and amino acid transport, general protein synthesis and the biosynthesis of mammotropic hormones including placental lactogen and prolactin, and also play a role in steroidogenesis. The suggested role for IGFs in conceptus growth and development has been proven by the result of IGF-I, IGF-II or IGF receptor gene disruption(targeting) of murine embryos by the homologous recombination technique. Mice carrying a null mutation for IGF-I and/or IGF-II or type I IGF receptor undergo delayed prenatal and postnatal growth and development with 30-60% normal weights at birth. Moreover, mice lacking the type I IGF receptor or IGF-I plus IGF-II die soon after birth. Intrauterine IGFBPs generally are believed to sequester IGF ligands within the uterus or to play a role of negative regulators of IGF actions by inhibiting IGF binding to cognate receptors. However, when it is taken into account that IGFBP-1 is expressed and secreted in primate uteri in amounts assessedly far exceeding those of local IGFs and that IGFBP-1 is one of the major secretory proteins of the primate decidua, the possibility that this IGFBP may have its own biological activity independent of IGF cannot be excluded. Evidently, elucidating the exact role of each IGFBP is an essential step into understanding the whole IGF system. As such, further research in this area is awaited with a lot of anticipation and attention.

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