• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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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.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.179-183
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• 2016

Even though klotho deficiency in mice exhibits multiple aging-like phenotypes, studies using large animal models such as pigs, which have many similarities to humans, have been limited due to the absence of cell lines or animal models. The objective of this study was to generate homozygous klotho knockout porcine cell lines and cloned embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and Cas9 RNPs were transfected into porcine fibroblasts. The transfected fibroblasts were then used for single cell colony formation and 9 single cell-derived colonies were established. In a T7 endonuclease I mutation assay, 5 colonies (#3, #4, #5, #7 and #9) were confirmed as mutated. These 5 colonies were subsequently analyzed by deep sequencing for determination of homozygous mutated colonies and 4 (#3, #4, #5 and #9) from 5 colonies contained homozygous modifications. Somatic cell nuclear transfer was performed to generate homozygous klotho knockout cloned embryos by using one homozygous mutation colony (#9); the cleavage and blastocyst formation rates were 72.0% and 8.3%, respectively. Two cloned embryos derived from a homozygous klotho knockout cell line (#9) were subjected to deep sequencing and they showed the same mutation pattern as the donor cell line. In conclusion, we produced homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts.

• Korean Journal of Veterinary Research
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• v.54 no.4
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• pp.225-231
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• 2014

Klotho deficiency is an early event in acute kidney injury (AKI) that exacerbates acute kidney damage. The present study explored the expression of Klotho and inflammation related factors in cisplatin-induced AKI. Rats (n = 18) were treated with cisplatin intraperitoneal injection (5 mg/kg) or left untreated as controls (n = 6), then sacrificed at 5 (n = 6) and 10 days (n = 6) treatment. Five days after cisplatin injection, the serum kidney enzymes and kidney cell apoptosis were significantly increased. Moreover, the expression of Klotho was decreased when compared to the control group, especially in the cortex and outer medulla regions. In contrast, inflammation related signals including nuclear factor kappa B, tumor necrosis factor-${\alpha}$, and tumor necrosis factor-like weak inducer of apoptosis were enhanced. However, 10 days after cisplatin injection, Klotho expression was enhanced upon both IHC and Western blot analysis, with slightly recovered renal function and decreased apoptosis. Furthermore, inflammation related signals expression was decreased relative to the 5 days group. Overall, this study confirmed the opposite expression patterns between Klotho and inflammation related signals and their localization in cisplatin-induced AKI kidney.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.2
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• pp.167-176
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• 2023

This study aims to explore the impact of Rehmannioside D (RD) on ovarian functions of rats with diminished ovarian reserve (DOR) and its underlying mechanisms of action. A single injection of cyclophosphamide was performed to establish a DOR rat model, and fourteen days after the injection, the rats were intragastrically administrated with RD for two weeks. Rat estrus cycles were tested using vaginal smears. Ovarian tissues were histologically evaluated, the number of primordial, mature, and atretic follicles was calculated, and the apoptotic rate of granulosa cells. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels were determined by ELISA assays. Protein levels of Forkhead Box O1 (FOXO1), KLOTHO, Bcl-2, and Bax were investigated in ovarian tissues of DOR rats. The binding between FOXO1 and KLOTHO was verified by ChIP assay. High-dose administration of RD into DOR rats improved their estrus cycles, increased ovarian index, enhanced the number of primordial and mature follicles, reduced the number of atretic follicle number, and ovarian granulosa cell apoptosis in addition to inhibiting FSH and LH levels and upregulating E₂ expression. FOXO1 and KLOTHO were significantly suppressed in DOR rats. FOXO1 knockdown partially suppressed the protective effects of RD on DOR rats, and KLOTHO overexpression could restore RD-induced blockade of DOR development despite knocking down FOXO1. FOXO1 antibody enriched KLOTHO promoter, and the binding between them was reduced in DOR group compared to that in sham group. RD improved ovarian functions in DOR rats and diminished granulosa cell apoptosis via the FOXO1/KLOTHO axis.

• Biomedical Science Letters
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• v.29 no.1
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• pp.1-10
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• 2023

Since its first identification in 1995, klotho (KL) has become the most promising gene to consider for suppressing aging and aging-related diseases. KL knockout mice exhibited similar phenotypes found in human with premature aging such as short lifespan, osteoporosis, arteriosclerosis and hearing loss. Genetically modified mice overexpressing KL prolonged lifespan more than 20%. Also, clinical reports have indicated decreased concentration of the circulating KL protein in blood, which is called soluble klotho (sKL), is closely related to development of senile diseases. The best way to discover significance of sKL on the development of the diseases might be comparison of sKL concentration between controls and patients. Here we analyzed published clinical reports identified sKL concentration in the cohorts. The sKL concentrations were displayed using heatmap for better comparison. In most of the senile diseases, disease progression was inversely related with sKL concentration. Hypertension was the only disease had no relationship, while schizophrenia was the only disease had direct proportion to the disease progression. Overall, sKL concentration in blood could be a marker to determine current severity of the senile diseases and even to estimate disease progression for the patients at the onset of their senile diseases.

• Tuberculosis and Respiratory Diseases
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• v.71 no.4
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• pp.254-258
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• 2011

Background: Although the aging process and features of chronic obstructive pulmonary disease (COPD) have several similarities, the relationship between aging and COPD pathogenesis remains incompletely understood. The klotho gene was found to be related to premature aging and emphysematous changes in an animal model. We investigated whether klotho gene polymorphisms are related to COPD susceptibility and emphysema severity. Methods: A total of 219 COPD subjects from the Korean Obstructive Lung Disease Cohort and 305 control subjects were genotyped for two single nucleotide polymorphisms (SNPs) of the klotho gene associated with coronary artery disease. Logistic regression was performed to determine the association of these SNPs with COPD susceptibility and linear regression was performed to investigate their association with emphysema severity in COPD subjects. Results: The mean age of the COPD subjects was 66 years and their mean FEV1 was 1.46 L. There were no associations between either SNP or COPD susceptibility (p=0.6 and 0.2, respectively) and there were no associations with emphysema severity. Conclusion: Genetic polymorphisms of the klotho gene were not associated with COPD in a Korean population.

• Korean Journal of Veterinary Research
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• v.56 no.1
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• pp.15-21
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• 2016

NAD(P)H-quinone oxidoreductase-1 (NQO1) is a down-stream target gene of nuclear factor erythroid 2-related factor 2 (Nrf2), and performs diverse biological functions. Recently, NQO1 is recognized as an effective gene for the cytotoxic inserts with its diverse biological functions, which is focused on antioxidant properties. The aim of present study was to assess the impact of NQO1 knockdown on cytoprotection-related protein expression in cisplatin cytotoxicity by using small interfering (si) RNA targeted on NQO1 gene. Cytotoxicity of cisplatin on ACHN cells was assessed in a dose- and time-dependent manner after siScramble or siNQO1 treatment. After cisplatin treatment, cells were subjected to cell viability assay, western-blot analysis, and immunofluorescence study. The cell viability was decreased in the siNQO1 cells (50%) than the siScramble cells (70%) after 24 h of cisplatin ($20{\mu}M$) treatment. Moreover, cytoprotection-related protein expressions were markedly suppressed in the siNQO1 cells after cisplatin treatment. The expression of Nrf2 and Klotho were decreased by 20% and 40%, respectively, of that in siScramble cells. Nrf2 and Klotho activation were also decreased in cisplatin treated siNQO1 cells, confirmed by cytoplasm-tonuclear translocation. Our findings demonstrate that the increased cisplatin-induced cytotoxicity was accompanied by suppressed Nrf2 activation and Klotho expression in siNQO1 cells.

• Journal of Embryo Transfer
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• v.29 no.4
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• pp.375-383
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• 2014

Klotho (KL) is a single transmembrane protein composed of KL1 and KL2 repeats possessing ${\beta}$-glucuronidase activity and maintains calcium homeostasis in physiological state. It has been implicated in pigs that calcium is important for the establishment and maintenance of pregnancy, and our previous study has shown that transient receptor potential vanilloid type 6 (TRPV6), a calcium ion transporter, is predominantly expressed in the uterine endometrium during pregnancy in pigs. However, expression and function of KL in the uterine endometrium has not been determined in pigs. Thus, the present study determined expression and regulation of KL in the uterine endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that levels of KL mRNA decreased between Days 12 to 15 of the estrous cycle, and its expression showed a biphasic manner during pregnancy. KL mRNA was expressed in conceptuses and in chorioallantoic tissues during pregnancy. Explant culture study showed that expression levels of KL were not affected by treatment of steroid hormones or interleukin-1beta during the implantation period. Furthermore, levels of KL mRNA in the uterine endometrium from gilts carrying somatic cell nuclear transfer (SCNT)-derived embryos were significantly lower than those from gilts carrying natural mating-derived embryos on Day 12 of pregnancy. These results exhibited that KL was expressed at the maternal-conceptus interface in a pregnancy status- and stage-specific manner, and its expression was affected by SCNT procedure, suggesting that KL may play an important role in the establishment and maintenance of pregnancy in pigs.

• Journal of Life Science
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• v.30 no.7
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• pp.640-650
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• 2020

Fibroblast growth factor 21 (FGF21) is an atypical member of the FGF protein family which is highly synthesized in the liver, pancreas, and adipose tissue. Depending on the expression tissue, FGF21 uses endo- or paracrine features to regulate several metabolic pathways including glucose metabolism and energy homeostasis. Different physiologically stressful conditions such as starvation, a ketogenic diet, extreme cold, and mitochondrial dysfunction are known to induce FGF21 synthesis in various tissues to exert either adaptive or defensive mechanisms. More specifically, peroxisome proliferator-activated receptor gamma and peroxisome proliferator-activated receptor alpha control FGF21 expression in adipose tissue and liver, respectively. In addition, the pharmacologic administration of FGF21 has been reported to decrease the body weight and improve the insulin sensitivity and lipoprotein profiles of obese mice and type 2 diabetes patients meaning that FGF21 has attracted huge interest as a therapeutic agent for type 2 diabetes, obesity, and non-alcoholic fatty liver disease. However, understanding FGF21 remains complicated due to the paradoxical condition of its tissue-dependent expression. For example, nutrient deprivation largely increases hepatic FGF21 levels whereas adipose tissue-derived FGF21 is increased under feeding condition. This review discusses the issues of interest that have arisen from existing publications, including the tissue-specific function of FGF21 and its action mechanism. We also summarize the current stage of a clinical trial using several FGF21 analogs.