• 생명과학회지
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• 제22권10호
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• pp.1428-1433
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• 2012

장수 또는 노화에 관한 연구는 여러 가지 유전적 요인과 생리학적 및 환경 요인들의 복잡한 조합에 의해 결정되므로, 이와 관련된 연구는 매우 흥미로운 분야이나 또한 어려운 주제이다. 지난 수십 년 동안 장수 또는 노화에 관여하는 분자 메커니즘을 찾기 위하여 동물 모델을 사용한 유전학적 접근법으로, 특이적 유전자를 결손 시키는 연구는 귀중한 도구임이 입증되었다. 장수에 관한 첫 번째 연구는 꼬마선충의 돌연변이체에서 발견되었으며, 이 선충의 인슐린/인슐린유사 성장인자-1 회로가 장수에 관여함이 밝혀졌다. 인슐린유사 성장인자-1은 인슐린과 유사한 아미노산 서열을 가진 폴리펩타이드로, 세포의 정상적인 성장과 발달에 관여한다. 이 발견 이후 인슐린/인슐린유사 성장인자-1 회로에 관여하는 많은 인자들이 선충과 초파리 연구에서 장수에 관여함이 밝혀졌다. 또한 특이적 유전자를 결손 시킨 생쥐 모델을 이용한 연구에서도 인슐린/인슐린유사 성장인자-1 회로뿐 아니라 성장호르몬/인슐린유사 성장인자 회로도 장수에 관여함이 지난 수십 년 동안의 연구결과로 밝혀졌다. 간 조직 특이적으로 인슐린유사 성장인자-1 유전자를 결손 시킨 생쥐모델을 이용한 최근의 연구 결과에 의하면 인슐린유사 성장인자-1 자체도 장수에 관여함이 최초로 밝혀졌으며, 이는 인슐린유사 성장인자-1 회로가 무척추동물뿐 아니라 척추동물에서도 장수에 관여함을 명백하게 보여주는 결과이다. 장수를 조절하는 분자 메커니즘은 아직 완전하게 설명되지 않지만, 감소되어진 인슐린유사 성장인자-1의 신호가 장수와 노화의 조절에 중요한 역할을 하며, 인슐린유사 성장인자-1 회로에 관여하는 여러 가지 유전자들의 장수에서의 역할을 유전자 조작된 생쥐모델을 이용하여 집중적으로 검토하려 한다.

• 한방안이비인후피부과학회지
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• 제20권1호통권32호
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• pp.27-37
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• 2007

Background and Objective : Psoriasis is a chronic skin disease characterized by angiogenesis. It has been reported that growth factor as vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF)-II are overexpressed in psoriatic epidermis. This stydy was carried out for whether SB extracts have an anti-angiogenic effect for angiogenic factor. Method : To investigate the inhibitory effect of VEGF expression by the SB extracts, we performed MTS assay, western blots using HaCaT cells. HaCaT cells were pretreated with SB extracts for 1 hour followed by treatment with IGF-II. Result : SB extracts significantly reduced IGF-II induced HIF-1 ${\alpha}$ protein level via p53 and MAPK pathway in HaCaT cells. Also, SB extracts inhibited IGF-II induced VEGF mRNA and protein expression levels in the HaCaT keratinocytes. Conclusion : These results suggest that inhibition of HIF-1 ${\alpha}$ and VEGF expressions by SB extracts contributes to the anti-angiogenic effects.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.613-619
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• 2016

Diabetic cardiomyopathy (DCM), a serious complication of diabetes mellitus, is associated with changes in myocardial structure and function. This study sought to explore the ability of insulin-like growth factor-1 (IGF-1) to modulate DCM and its related mechanisms. Twenty-four male Wistar rats were injected with streptozotocin (STZ, 60 mg/kg) to mimic diabetes mellitus. Myocardial fibrosis and apoptosis were evaluated by histopathologic analyses, and relevant proteins were analyzed by Western blotting. Inflammatory factors were assessed by ELISA. Markers of oxidative stress were tested by colorimetric analysis. Rats with DCM displayed decreased body weight, metabolic abnormalities, elevated apoptosis (as assessed by the bcl-2/bax ratio and TUNEL assays), increased fibrosis, increased markers of oxidative stress (MDA and SOD) and inflammatory factors (TNF-${\alpha}$ and IL-$1{\beta}$), and decreased phosphorylation of Akt and glycogen synthase kinase (GSK-$3{\beta}$). IGF-1 treatment, however, attenuated the metabolic abnormalities and myocardial apoptosis, interstitial fibrosis, oxidative stress and inflammation seen in diabetic rats, while also increasing the phosphorylation levels of Akt and GSK-$3{\beta}$. These findings suggest that IGF-1 ameliorates the pathophysiological progress of DCM along with an activation of the Akt/GSK-$3{\beta}$ signaling pathway. Our findings suggest that IGF-1 could be a potential therapeutic choice for controlling DCM.

• Asian-Australasian Journal of Animal Sciences
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• 제21권12호
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• pp.1760-1765
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• 2008

A total of 60 one-day-old Yellow-feather broiler chickens were allotted into treatment and control groups. The treatment group was fed with the diet supplemented with 3% conjugated linoleic acid (CLA) for 48 d, while control group was fed with the diet supplemented with 3% rapeseed oil. Chickens were slaughtered in each group at the age of 49 d, and the blood and the abdominal adipose tissue were sampled. Serum cLeptin and serum cAdiponectin were measured by ELISA. The total RNA was extracted from adipose tissue to measure the abundance of the chicken growth hormone receptor (cGHR), insulin-like growth factor 1 (cIGF-1), insulin-like growth factor I receptor (cIGF-IR), peroxisome proliferator-activated receptor gamma ($cPPAR{\gamma}$), cAdiponectin and cAdipoIR mRNA by RT-PCR using ${\beta}$-actin as an internal standard. Results showed that the CLA decreased the abdominal fat index by 20.93% (p<0.05). The level of serum cLeptin but not serum cAdiponectin was significantly increased by CLA treatment (p<0.05). CLA down-regulated the relative abundance of cGH-R mRNA and $cPPAR{\gamma}$ mRNA in abdominal adipose tissue by 24.74% (p<0.05) and 66.52% (p<0.01) respectively. However, no differences were found between CLA treatment group and control group (p>0.05) in the relative abundance of cIGF-1, cIGF-IR, cAdiponectin, and cAdipoIR mRNA in abdominal adipose tissue. The data suggested that CLA inhibited abdominal fat deposition in broiler chicken may be determined by decreasing the GHR available for GH, and by inhibiting the differentiation of preadipocytes via down-regulation of $PPAR{\gamma}$, but independent of IGF and (or) GH-IGF pathway or adiponectin action.

• Molecules and Cells
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• 제37권1호
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• pp.51-57
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• 2014

NOG1 is a nucleolar GTPase that is critical for 60S ribosome biogenesis. Recently, NOG1 was identified as one of the downstream regulators of target of rapamycin (TOR) in yeast. It is reported that TOR is involved in regulating lifespan and fat storage in Caenorhabditis elegans. Here, we show that the nog1 ortholog (T07A9.9: nog-1) in C. elegans regulates growth, development, lifespan, and fat metabolism. A green fluorescence protein (GFP) promoter assay revealed ubiquitous expression of C. elegans nog-1 from the early embryonic to the adult stage. Furthermore, the GFP-tagged NOG-1 protein is localized to the nucleus, whereas the aberrant NOG-1 protein is concentrated in the nucleolus. Functional studies of NOG-1 in C. elegans further revealed that nog-1 knockdown resulted in smaller broodsize, slower growth, increased life span, and more fat storage. Moreover, nog-1 over-expression resulted in decreased life span. Taken together, our data suggest that nog-1 in C. elegans may be an important player in regulating life span and fat storage via the insulin/IGF pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제20권5호
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• pp.459-466
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• 2016

Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than $Lnk^{-/-}$ MSCs. An ex vivo adipogenic differentiation assay showed that $Lnk^{-/-}$ MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$) and its adipogenic target genes (LPL and FABP4) significantly decreased in $Lnk^{-/-}$ MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the $IGF-1/Akt/PPAR-{\gamma}$ pathway.

• Journal of Ginseng Research
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• 제46권4호
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• pp.526-535
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• 2022

Background: During the pathogenesis of tendinopathy, the chronic inflammation caused by the injury and apoptosis leads to the generation of scars. Ginsenoside Rg1 (Rg1) is extracted from ginseng and has anti-inflammatory effects. Rg1 is a unique phytoestrogen that can activate the estrogen response element. This research aimed to explore whether Rg1 can function in the process of tendon repair through the estrogen receptor. Methods: In this research, the effects of Rg1 were evaluated in tenocytes and in a rat model of Achilles tendinitis (AT). Protein levels were shown by western blotting. qRT-PCR was employed for evaluating mRNA levels. Cell proliferation was evaluated through EdU assay and cell migration was evaluated by transwell assay and scratch test assay. Results: Rg1 up-regulated the expression of matrix-related factors and function of tendon in AT rat model. Rg1 reduced early inflammatory response and apoptosis in the tendon tissue of AT rat model. Rg1 promoted tenocyte migration and proliferation. The effects of Rg1 on tenocytes were inhibited by ICI182780. Rg1 activates the insulin-like growth factor-I receptor (IGF1R) and MAPK signaling pathway. Conclusion: Rg1 promotes injured tendon healing in AT rat model through IGF1R and MAPK signaling pathway activation.

• International Journal of Oral Biology
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• 제49권2호
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• pp.27-33
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• 2024

Diabetes, a chronic hyperglycemic condition, is caused by insufficient insulin secretion or functional impairment. Long-term inadequate regulation of blood glucose levels or hyperglycemia can lead to various complications, such as retinopathy, nephropathy, and cardiovascular disease. Recent studies have explored the molecular mechanisms linking diabetes to bone loss and an increased susceptibility to fractures. This study reviews the characteristics and molecular mechanisms of diabetes-induced bone disease. Depending on the type of diabetes, changes in bone tissue vary. The molecular mechanisms responsible for bone loss in diabetes include the accumulation of advanced glycation end products (AGEs), upregulation of inflammatory cytokines, induction of oxidative stress, and deficiencies in insulin/IGF-1. In diabetes, alveolar bone loss results from complex interactions involving oral bacterial infections, host responses, and hyperglycemic stress in periodontal tissues. Therapeutic strategies for diabetes-induced bone loss may include blocking the AGEs signaling pathway, decreasing inflammatory cytokine activity, inhibiting reactive oxygen species generation and activity, and controlling glucose levels; however, further research is warranted.

• The Korean Journal of Physiology and Pharmacology
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• 제20권3호
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• pp.297-304
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• 2016

Klotho functions as a tumor suppressor predominantly expressed in renal tubular cells, the origin of clear cell renal cell carcinoma (ccRCC). Altered expression and/or activity of growth factor receptor have been implicated in ccRCC development. Although Klotho suppresses a tumor progression through growth factor receptor signaling including insulin-like growth factor-1 receptor (IGF-1R), the role of Klotho acting on IGF-1R in ccRCC and its clinical relevance remains obscure. Here, we show that Klotho is favorable prognostic factor for ccRCC and exerts tumor suppressive role for ccRCC through inhibiting IGF-1R signaling. Our data shows the following key findings. First, in tumor tissues, the level of Klotho and IGF-1R expression are low or high, respectively, compared to that of adjacent non-neoplastic parenchyma. Second, the Klotho expression is clearly low in higher grade of ccRCC and is closely associated with clinical outcomes in tumor progression. Third, Klotho suppresses IGF-1-stimulated cell proliferation and migration by inhibiting PI3K/Akt pathway. These results provide compelling evidence supporting that Klotho acting on IGF-1R signaling functions as tumor suppressor in ccRCC and suggest that Klotho is a potential carcinostatis substance for ccRCC.

• Tuberculosis and Respiratory Diseases
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• 제67권1호
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• pp.8-13
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• 2009

Background: The insulin receptor substrate-1 (IRS-1) is the primary docking molecule for the insulin-like growth factor I receptor (IGF-IR), and is required for activation of the phosphatidylinositol 3'-kinase (PI3K) pathway. IRS-1 activation of the (PI3K) pathway regulates IGF-mediated survival, enhancement of cellular motility and apoptosis. Therefore, we attempted to ascertain whether IRS-1 genetic variations affect an individual's risk for non-small cell lung cancer (NSCLC). Methods: Two-hundred and eighteen subjects, either diagnosed with NSCLC or control subjects, were matched by age, gender and smoking status. Genomic DNA from each subject was amplified by PCR and analyzed according to the restriction fragment length polymorphism (RFLP) profile to detect the IRS-1 G972R polymorphism. Results: The frequencies of each polymorphic variation, in the control population, were as follows: GG=103 (94.5%) and GR=6 (5.5%); for the NSCLC subjects, the genotypic frequencies were as follows: GG=106 (97.2%) and GR=3 (2.8%). We could not demonstrate statistically significant differences in the genotypic distribution between the NSCLC and the control subjects (p=0.499, Fisher's Exact test). The relative risk of NSCLC, associated with the IRS-1 G972R polymorphic variation, was 1.028 (95% CI; 0.63~9.90). In addition, we found no differences between polymorphic variants with regard to the histological subtype of NSCLC. Conclusion: We did not observe any noteworthy differences in the frequency of the IRS-1 G972R polymorphism in NSCLC patients, compared to control subjects. These results suggest suggesting that, in our study population, the IRS-1 G972R polymorphism does may not appear to be associated with an increased risk of NSCLC.