• 한국수정란이식학회지
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• 제12권3호
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• pp.229-246
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• 1997

Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!

• 생명과학회지
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• 제17권9호통권89호
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• pp.1224-1231
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• 2007

사람의 섬유아세포인 GM10에서 glucose 농도에 따른 IGFBP-5의 존재와 발현에 미치는 영향을 살펴보고 당뇨병과 관련된 in vitro model system으로서의 활용 가능성을 검토하고자 하였다. 섬유아세포인 GM10 세포를 시용하여 glu-cose 배양 조건에 따른 IGFBP-5의 존재와 발현에 미치는 영향을 살펴보았다. 그 결과, IGFBP-5의 단백질 수준은 고농도 glucose 배양 조건에서 증가하였으나, IGFBP-5 mRNA 발현에는 아무런 영향을 나타내지 않았다. IGFBP-5 protease 활성은 고농도 glucose 배양 조건에서 높았다. IGF- I 과 인슐 린은 IGFBP-5 protease 활성에 관여하는 것으로 보여지며, GM10 세포에 있어서 IGFBP-5의 분해에는 serine protease 뿐만 아니라 metalloprotease가 관여하는 것으로 나타났다. 또한, gelatin zymography를 통한 protease 활성은 고농도 glucose 배양 조건에서 크게 나타났으며, 시간 의존적으로 증가하였다. 본 연구 결과를 바탕으로 IGFs와 같은 세포 성장인자에 대한 연구는 세포수준의 당뇨병과 관련된 in vitro model system이 가능하리라고 여겨지며 더 많은 연구가 진행되어야 할 것으로 보인다.

• 한국식품영양과학회지
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• 제26권2호
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• pp.285-290
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• 1997

이상의 결과를 요약하연, 혈당값은 정상대조군 78{\pm}6.20mg/dl, 인슐린 비의존형 당뇨병 환자 $184{\pm}18.94mg/dl$로 인슐린 비의존형 당뇨병 환자의 혈당값이 유의적으로 높았다. IGF-I의 수준은 정상대조군 $9.32{\pm}1.48{\mu}g/ml$, 인슐린 비의존형 당뇨병 환자 $4.19{\pm}0.84{\mu}g/ml$로 인슐린 비의존형 당뇨병 환자의 IGF-I 수준이 유의적으로 낮았다. 인슐린 비의존형 당뇨병 환자의 혈청 중 IGFBP-1, -2는 증가한 반면, IGFBP-3, -4, -5는 감소하였다. IGFBP-3의 분해에 관여하는 효소는 PMSF, aprotinin, EDTA에 의해 저해되어 metal-dependent serine proteases임을 확인하였고, 효소의 크기가 대략 97,66kDa 이었으며 효소활성이 인슐린 비의존형 당뇨병 환자에게서 큼을 확인하였다.

• 한국동물생명공학회지
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• 제37권3호
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• pp.155-161
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• 2022

Pregnancy-associated plasma protein-A (PAPP-A) is known as an important biomarker for fetal abnormality during first trimester and has a pivotal role in follicle development and corpus luteum formation. And also, it is being revealed that an expression of PAPP-A in various cells and tissues such as cancer and lesion area. PAPP-A is the major IGF binding protein-4 (IGFBP-4) protease. Cleavage of IGFBP-4 results in loss of binding affinity for IGF, causing increased IGF bioavailability for proliferation, survival, and migration. Additionally, PAPP-A can be used as a promising therapeutic target for healthy longevity. Despite growing interest, almost nothing is known about how PAPP-A expression is regulated in any tissue. This review will focus on what is currently known about the zinc metalloproteinase, PAPP-A, and its role in cells and tissues. PAPP-A is expressed in proliferating cells such as fetus in uterus, granulosa cells in follicle, dermis in wound, cancer cells, and Sertoli cells in testis. They have common characteristics of proliferation faster than normal cells with stimulating IGFs action and inhibiting IGFBPs. The PAPP-A functions and expression studies in livestock have not yet been conducted much. Further studies are needed to use PAPP-A as a marker for healthy longevity in animal science.