The effect of IGFBP3 gene knockout by the CRISPR/Cas9 system on the IGF-1 pathway in murine cells.

BACKGROUND: The IGF-1 signaling pathway has been deeply involved in the aging mechanism. The insulin-like growth factor binding protein 3 (IGFBP-3) is a protein that binds to IGF-1 that regulates growth, survival, and aging. OBJECTIVE: The purpose of this study was to investigate the impact of the IGFBP3 gene knockout (KO) on the expressions of aging-related proteins and genes using the CRISPR/Cas9 system. METHODS: The IGFBP3 gene knockout (KO) was performed by the CRISPR/Cas9 system. Sanger DNA sequencing and Indel analyses were used to verify the induction of mutation. RESULTS: First, Sanger DNA sequencing was used to analyze the IGFBP3 gene knockout in murine cells (B16F1). The isolation of three colonies with the mutated DNA sequences in the IGFBP3 gene was validated. In addition, the expression levels of the IGFBP3 gene and protein in the edited B16F1 cells were lower than in those of normal B16F1 cells in western blot analysis as well as RT-PCR and qPCR. Moreover, IGFBP3 gene KO cells enhanced the level of SA-ß-gal staining and short telomere length compared to normal B16F1 cells. In particular, it was found that the expression levels of senescence-related proteins such as PI3K, AKT1, PDK1, and p53 were higher in IGFBP3 gene KO cells than in normal cells in both the absence and presence of IGF-1. CONCLUSIONS: Therefore, the above findings could provide a clue that IGFBP3 could play a key role in the aging mechanism.

Putrescine Upregulates Melanogenesis Through Modulation of MITF Transcription Factor in B16F1 Mouse Melanoma Cells.

Research background: Ageing is a biochemical, metabolic and genetic physiological phenomenon. The suppression of melanin biosynthesis, evident in the greying of the hair, is a hallmark of ageing resulting from translation failure, reduced enzyme activity and cellular senescence. Putrescine, the smallest member of the polyamine family and an organic chemical, is present in living mammalian cells and plays a crucial role in regulating skin melanogenesis. Therefore, the purpose of this study is to explore the effect of putrescine on the signalling pathways of melanogenesis in melanoma cells. Experimental approach: Melanin production capacity of putrescine was analysed using a tyrosinase activity assay. To assess the cell viability of B16F1 cells exposed to putrescine, a tetrazolium dye MTT assay was performed. The effect of putrescine on melanin synthesis in the presence of H2O2 was evaluated using various in vitro assays in B16F1 cells. The effect of putrescine on melanin production in B16F1 cells was determined using a specific melanin production assay. Gene expression was analysed using real-time polymerase chain reaction (RT-PCR). Furthermore, the effect of putrescine on the expression of proteins related to melanin production in the cells treated with H2O2 was analysed by immunofluorescence and Western blot analysis. Results and conclusions: Putrescine increased tyrosinase activity and showed no cytotoxicity in B16F1 cells. In addition, putrescine effectively scavenged H2O2, as shown by the reduction of intracellular H2O2 amounts in 2',7'-dichlorofluorescin diacetate analysis, and promoted melanin production in living cells. The stimulation of melanogenesis by putrescine was attributed to the increased expression of Mitf, Tyr, Trp-1 and Trp-2 genes. Immunofluorescence assays revealed that putrescine enhanced the expression of proteins associated with melanogenesis and upregulated TYR, TRP-1 and TRP-2 via the microphthalmia-associated transcription factor (MITF) and increased the expression of methionine sulfoxide reductases A (MSRA) and B (MSRB) in the cells treated with H2O2, effectively promoting melanogenesis. These results suggest that putrescine can be used to stimulate melanin synthesis. Novelty and scientific contribution: This is the first study to investigate the effect of putrescine on the signalling pathways of melanogenesis in B16F1 melanoma cells. The results confirm that putrescine can promote melanogenesis through the expression of TYR, TRP-1 and TRP-2 via the MITF in cells treated with H2O2. Putrescine can be used exclusively as a cosmetic product to prevent premature greying of hair.

Development of gold nanocluster complex for the detection of tumor necrosis factor-alpha based on immunoassay.

Tumor necrosis factor-alpha, TNF-α, a cytokine recognized as a key regulator of inflammatory responses, is primarily produced by activated monocytes and macrophages. Measuring TNF-α levels serves as a valuable indicator for tracking several diseases and pathological states. Gold nanotechnology has been identified as a highly effective catalyst with unique properties for measuring inflammatory cytokines. This study aimed to synthesize gold nanoclusters (AuNCs) and the AuNCs-streptavidin system, along with their characterizations and spherical morphology. The detection of TNF-α antigen with AuNCs was determined, and a new immunoassay-based AuNCs analytical platform was studied. In this study, it was demonstrated that the synthesized AuNCs and AuNCs-streptavidin showed a bright-yellow appearance with absorption peaks at A600 and A610 nm, respectively. The approximately spherical shape was observed by TEM analysis. The AuNCs demonstrated a sensitivity limit for the detection of the TNF-α antigen, with a linear dose-dependent detection range of less than 1.25 ng/mL. The products of the band sizes and band intensities were proportional to the amount of TNF-α in the range of ∼80 kDa, ∼55 kDa, and âˆ¼ 25 kDa in western blot analysis. The TNF-α in cell lysate was successfully detected using an immunoassay after the activation of RAW264.7 cells with lipopolysaccharide (LPS). This assay may serve as a viable alternative for TNF-α detection with high speed, sensitivity, and qualities, ensuring its broad applications.

Silibinin Inhibits Cell Invasion through the Inhibition of MMPs, p-p38, and IL-1ß in Human Fibrosarcoma Cells.

BACKGROUND AND AIMS: Normal cells become tumorigenic owing to mutations in oncogenes and tumor suppressor genes modulating cell division. Cancer cells break down extracellular matrix to metastasize other tissues. Therefore, the development of natural and synthetic substances that suppress metastatic enzymes such as matrix metalloproteinase (MMP)-2 and MMP-9 is useful to inhibit metastasis. Silibinin is the main ingredient of silymarin extracted from the seeds of milk thistle plants having lung cancer-suppressing effects and liver protection. The purpose of this study was to investigate the inhibitory effect of silibinin on the invasion of human fibrosarcoma cells. METHODS: The effect of silibinin on cell viability was measured in HT1080 cells using an MTT assay. The MMP-9 and MMP-2 activities were analyzed using a zymography assay. The expression of proteins in cytoplasm related to metastasis was examined by western blot analysis and immunofluorescence assay. RESULTS: In this study, silibinin above 20 µM showed growth inhibitory effects. Silibinin above 20 µM remarkably inhibited the levels of MMP-2 and MMP-9 activation under phorbol myristate acetate (PMA) treatment conditions. Furthermore, silibinin at 25 µM reduced the levels of MMP-2, IL-1ß, ERK-1/2, and p-p38 expression and silibinin above 10 µM inhibited cell invasion on HT1080 cells. CONCLUSIONS: These findings indicate that silibinin may have an inhibitory effect on the enzymes involved in invasion, hence it might influence the metastatic ability of tumor cells.

ß-Caryophyllene oxide inhibits metastasis by downregulating MMP-2, p-p38 and p-ERK in human fibrosarcoma cells.

When cancer cells transform into malignant tumors, they gain the ability to ignore growth-inhibiting signals, have endless reproduction potential, resist apoptosis, and induce angiogenesis and invade other tissues. Matrix metalloproteinases (MMPs) allow tumor cells to move into surrounding tissues in many malignancies, but metastasis is blocked by MMPs inhibitors. Therefore, the effect of ß-caryophyllene oxide (CPO) contained in Piper nigrum on Mitogen-activated protein kinase (MAPKs) related to MMPs signaling pathways in human fibrosarcoma was examined in HT1080 cells. The effect of CPO on cell viability was performed using the MTT assay. Cytotoxicity was observed in the presence of CPO above 16 µM. Next, gelatin zymography was performed in the cells activated with phorbol-12-myristate-13-acetate (PMA). It was found that CPO at 32 µM reduced MMP-9 activity by 28% and MMP-2 activity by 60%. To confirm the effect of CPO on MMPs, Western blot analyses for MMP-2, MAPKs were carried out in this study. The expression level of MMP-2 was reduced by 45% in the presence of CPO at 32 µM, but those of p-p38 and p-ERK were reduced by 50% and 40%, respectively. CPO decreased the expression levels of MMP-2 and MMP-9 in the immunofluorescence staining assay. Finally, an invasion assay was performed in PMA-treated human fibrosarcoma cells. It was demonstrated that CPO reduced cell invasion of HT1080 cells in a dose-dependent manner starting at a concentration of 2 µM. The above results suggest that CPO could be used as a potential candidate for the treatment of metastasis by inhibiting MMP-2, p-p38 and p-ERK. PRACTICAL APPLICATIONS: Cancer makes it easier for cells to spread to other tissue via blood and lymph systems. Tumor cells deplete nutrients and induce angiogenesis, which penetrates and spreads to other parts of the body. As a result, the effect of CPO against cell invasion was evaluated in this study. CPO reduced cancer cell invasion by inactivating p-ERK and p-p38, according to the findings. MMP-2 and MMP-9 activation and protein expression were also decreased by CPO. As a result, CPO might be used as an alternate treatment agent for preventing metastasis.

The effect of emodin on melanogenesis through the modulation of ERK and MITF signaling pathway.

The aim of this study was to investigate the effect of emodin derived from Polygonum multiflorum on melanin production in B16F1 cells. In this study, emodin did not show antioxidant activity in DPPH radical and reducing power assays. However, it was found that emodin scavenged intracellular H2O2. Emodin increased not only tyrosinase activity but also melanin synthesis in vitro. Moreover, emodin enhanced melanin synthesis by increasing the expression level of tyrosinase (TYR), tyrosine related protein (TRP)-1, TRP-2, MITF and SIRT1 proteins in live cells treated with H2O2 compared with H2O2 treatment group in the analyses of western blot and immunofluorescence. Moreover, emodin suppressed ERK activation by SIRT1 and FOXO1. Thus, emodin promoted melanin synthesis by increasing the expression of TRP-1, TRP-2, tyrosinase through the activation of MITF transcription factor. These findings suggest that emodin could promote melanin production related to anti-hair graying.

The down-regulation of melanogenesis via MITF and FOXO1 signaling pathways in SIRT1 knockout cells using CRISPR/Cas9 system.

Hair graying is processed by the inactivation of tyrosinase caused by the accumulation of oxidative stress and a decrease in the number of melanocytes. Therefore, the purpose of this study was to investigate the effect of SIRT1 gene knockout using the CRISPR/Cas9 system on the protein and gene expressions related to melanogenesis. In this study, the mutation in the SIRT1 knockout(KO) gene was verified by T7EI assay and Sanger DNA sequencing. Furthermore, the expression levels of SIRT1 protein and gene in KO cells were remarkably decreased compared with normal cells. Therefore, the SIRT1 gene KO cell line was successfully established for further study. The KO cells also increased SA-ß-galactosidase and decreased melanin production and the scavenging activity of hydrogen peroxide. In particular, the down-regulation of p38 and c-kit as well as the up-regulation of ERK resulted in the inactivation of MITF in the KO cells. Thus, KO cells reduced the expressions of Tyrosinase, Tyrosine hydroxylase, TRP-1 and TRP-2 through the negative modulation of MITF. Furthermore, SIRT1 gene KO cells negatively modulated antioxidant proteins such as Catalase, MnSOD, MsrA and MsrB3 through FOXO1 and Keap1. Therefore, it is suggested that SIRT1 could play a positive role in melanogenesis via MITF and FOXO1.

The relationship between melanin production and lipofuscin formation in Tyrosinase gene knockout melanocytes using CRISPR/Cas9 system.

Age spots are a significant phenotypic marker of aging formed by lipofuscin. Melanin is another skin pigment molecule responsible for skin aging. The present study aims to investigate the relationship between melanin production and lipofuscin synthesis in normal mouse melanoma cell line B16F1 cells and Tyrosinase (TYR) gene knockout cells. TYR gene KO cells were successfully developed using CRISPR/Cas9 system and confirmed by Sanger DNA sequencing analysis. Furthermore, the melanin production and lipofuscin formation were validated through RT-PCR and Western blot analysis. The expression levels of gene microphthalmia-associated transcription factor (MITF), Tyrosinase, tyrosine-related protein-1 (TRP-1), tyrosine-related protein-2 (TRP-2), and antioxidant proteins such as methionine sulfoxide reductase A (MSRA), Catalase and Glutathione reductase (GR) related to melanogenesis was found to be decreased in TYR gene KO cells compared with normal cells. Moreover, lipofuscin formation was increased in TYR gene KO cells compared to normal cells. Therefore, the above findings suggest that melanin production and lipofuscin formation could be linked by the TYR gene in melanocytes.

The inhibitory effect of Agrimonia Pilosa methanolic extract on matrix metalloproteinases in HT1080 cells.

The risk of cancer increases with aging due to the accumulation of cellular deterioration that can spread to other organs through the blood and lymphatic vessels. Therefore, the inhibition of metastasis is a major concern for the treatment of cancer. Several synthetic drugs have been developed for the treatment of various cancers. However, these drugs are effective; nonspecific action and side effects on the normal human cells limit their wide acceptance, thus demanding some potential alternative. Hence, the present study emphasizes investigating the effect of a methanolic extract of Agrimonia Pilosa (APLME) on matrix metalloproteinases (MMPs) in human fibroblast sarcoma cells. The action of APLME on MMP-2 and MMP-9 was investigated using gelatin zymography. APLME suppressed the activities of MMP-2 and MMP-9 in PMA (phorbol myristate acetate)-treated HT1080 cells. In addition, western blot analysis and immunofluorescence were performed to investigate the effect of APLME on the expression of the proteins that are the major proteins involved in cell invasion and metastasis. APLME treatment inhibited the expression of MMP-2 and MMP-9 in addition to the activations of JNK, ERK, and AKT-1. Furthermore, APLME was observed to suppress cell invasion related to metastasis using cell invasion assay. Therefore, the above findings indicate that APLME inhibits the expression activity of MMP-2 and MMP-9 via inactivation of ERK and JNK in addition to AKT-1, leading to inhibiting cell invasion. Therefore, these results indicate that APLME may be used as a candidate substance for inhibiting cell invasion. PRACTICAL APPLICATIONS: Cancer increases the cell invasion to other organs through the blood and lymphatic vessels. Cancer cells deplete the nutrients and create new blood vessels that infiltrate and metastasize to other tissues. Therefore, this present study examined the effect of Agrimonia Pilosa on cell invasion. It was found that Agrimonia Pilosa methanolic extract inhibited the invasion of cancer cells through the inactivation of ERK and JNK. In addition, APLME reduced the activation and protein expression of MMP-2 and MMP-9 in addition to AKT-1. Thus, APLME can be utilized as a potential alternative therapeutic agent for inhibiting metastasis.

SIRT7 gene knockout using CRISPR/Cas9 system enhances melanin production in the melanoma cells.

Melanin is a prominent pigment of skin and hair, and its deficiency can cause various disorders such as hair graying and albinism. The improvement of melanin production at a genetic level could offer an effective and permanent solution. Recently, SIRT7 has evoked an interest in the study of hair follicle stem cells, but its role in melanin synthesis remains unclear. In the present study, we have first successfully developed SIRT7 gene KO melanoma cells using the CRISPR/Cas9 system. It was found that the SIRT7 gene KO enhanced melanin production in melanoma cells. To validate the role of SIRT7 in melanin production, RT-PCR, western blot, and immunofluorescence staining assays were performed. The expression levels of melanin-producing genes and proteins (MITF, TRP1, TRP-2, TYR, TH) were significantly increased in SIRT7 gene KO cells compared to normal cells. In addition, melanin production was increased in KO cells higher than in normal cells through the image analysis. All these results suggest that SIRT7 could play an essential role in regulating melanin production, providing an alternative drug target to treat pigmentary disorders.

Spermidine promotes melanin production through an MITF signalling pathway.

Melanin plays an important role in determining skin colour. Apoptosis of melanocytes and defect in melanin production cause vitiligo. Various studies have been conducted to treat the disease, but its treatment is still difficult. Therefore, this study aimed to investigate the effect of spermidine, which is known as an inhibitor of ageing-related oxidized proteins, on melanogenesis. Even though spermidine above 50 µM had no effect on antioxidant activity and DOPA oxidation, it displayed tyrosinase activity. However, spermidine at 2000 µM was cytotoxic in B16F1 cells using MTT assay. Spermidine above 125 µM decreased the amount of intracellular hydrogen peroxide in a concentration-dependent manner in DCFH-DA analysis. It was also found that spermidine above 2000 µM increased melanin synthesis in living cells. However, spermidine above 1000 µM increased melanin synthesis in a concentration-dependent manner in H2 O2 -treated B16F1 cells. Furthermore, spermidine enhanced the expression of tyrosine hydroxylase via MITF transcription factor involved in melanogenesis in H2 O2 -treated B16F1 cells. Therefore, these results suggest that spermidine could be applied as a potential stimulator of melanin synthesis for the prevention of hair greying.

Effect of Lapachol on the Inhibition of Matrix Metalloproteinase Related to the Invasion of Human Fibrosarcoma Cells.

BACKGROUND: Anti-cancer effect of lapachol contained in Tabebuia avellandae has been poorly understood until now. OBJECTIVE: The aim of this study was to investigate the inhibitory effect of lapachol on MMPs related to cell invasion. Its action mechanism was elucidated by analyzing the activity and the expression of MMPs and the proteins involved in the signaling pathway of cell invasion. METHODS: The cytotoxicity of lapachol was evaluated by MTT assay in HT1080 cells. The effects of lapachol on the expression and the activation of MMPs were analyzed by western blot, immunofluorescence staining, and gelatin zymography assays. Their gene expression was analyzed by RT-PCR, and metastasis was evaluated by cell invasion assay. RESULTS: Lapachol below 2 µM showed no cytotoxicity. It was observed that lapachol above 0.5 µM inhibited the activation of MMP-2 and MMP-9 stimulated by PMA. In particular, the protein and gene expression levels of MMP-2 stimulated by PMA were remarkably decreased in the presence of lapachol at 1 µM compared with the PMA treatment group. In addition, lapachol increased the expression level of TIMP-1 compared with the PMA treatment group. Moreover, lapachol decreased the expression level of p-p38 among MAPKs compared with the PMA treatment group. It was also found that the expression level of p65, a part of NF-kB, in nuclei was reduced in the presence of lapachol above 0.5 µM compared with the PMA treatment group. In addition, lapachol inhibited the invasion of human fibrosarcoma cells stimulated with VEGF. CONCLUSION: Above results suggest that lapachol could play an important role in the modulation of MMPs related to cell invasion via the increase in TIMP-1 expression as well as the inactivation of p38 through NF-kB transcription factor.

Rapid and sensitive detection of melanin using glutathione conjugated gold nanocluster based fluorescence quenching assay.

In the present study, a rapid, facile, and highly sensitive assay based on glutathione conjugated gold nanocluster (GSH-AuNCs) is developed for the detection of melanin. The analysis of melanin which is linked to several diseases is crucial. The current methods for melanin estimation are complex and long, thus demands an alternative technology. In general, melanin exhibits photoactive properties, thus, it might have fluorescence quenching properties through the phenomenon of fluorescence resonance energy transfer. To verify our assumption, we have developed the fluorescence quenching assay based on gold nanocluster and melanin interaction. As a result, under the optimized condition, the developed quenching assay demonstrated the high selectivity and sensitivity toward melanin with a limit of detection and correlation coefficient of 0.060 µg/mL and 0.993, respectively. Moreover, the whole process represented the rapid assay time of 30 min to complete. To validate the performance of our assay on real samples, B16F1 cells lysate, and hair samples were tested that provided satisfactory results. Therefore, we believe that our assay due to good sensitivity and short assay time could be beneficial for the clinical diagnosis of melanin in the future study.

Tomatidine inhibits cell invasion through the negative modulation of gelatinase and inactivation of p38 and ERK.

BACKGROUND: Despite of the most effective surgical removal of malignant tumors, metastasis makes cancer treatment difficult. The studies on natural compounds to inhibit this metastasis have been actively performed until now. However, the effect of tomatidine on metastasis remains unclear. METHOD: The effect of tomatidine on antioxidative activity was measured with DPPH radical assay and reducing power assay. After treatment with tomatidine, the viability of human fibrosarcoma cells (HT1080 cells) was evaluated with MTT assay. The effect of tomatidine on the inhibition of matrix metalloproteinase-2 (MMP-2) and MMP-9, gelatinases related to metastasis, was analyzed using gelatin zymography, western blot and immunofluorescence staining. Cell invasion assay was used to investigate anti-metastasis activity of tomatidine. RESULT: Tomatidine showed no DPPH radical scavenging effect and showed 8% of reduction power at 8 µM. Furthermore, tomatidine below 8 µM showed more than 80% of cell viability in MTT assay. The inhibition of tomatidine on MMP-2 activity and its protein expression levels were observed by gelatin zymography, western blot and immunofluorescence. It was observed that tomatidine inhibited not only p38 and ERK but also cell invasion. CONCLUSION: Above results suggest that tomatidine could use as a potential candidate for cancer prevention and metastasis through the inhibitory effect on gelatinase.

TP53 Tumor-suppressor Gene Plays a Key Role in IGF1 Signaling Pathway Related to the Aging of Human Melanocytes.

BACKGROUND/AIM: The insulin-like growth factor 1 (IGF1) signaling pathway as an aging mechanism related to p53 in human melanogenesis remains unclear. The aim of this study was to investigate the relationship between p53 and IGF1 signaling pathway in young, senescent and H2O2-treated cells. MATERIALS AND METHODS: The protein and gene expression in young, senescent and H2O2-treated cells were analyzed using western blot and reverse transcription polymerase chain reaction (RT-PCR) assays, respectively. RESULTS: The expression levels of (phosphoinositide 3-kinases) PI3K, v-akt murine thymoma viral oncogene homolog 1 (AKT1), mammalian target of rapamycin, ß-catenin (CTNNB1), acetylated p53 (ac-p53), p53 and p-p21 proteins, related to IGF1 and p53 signaling pathways, were higher in senescent and H2O2-treated cells than those of young cells. Furthermore, AKT reduced melanogenesis through microphthalmia-associated transcription factor (MITF) inactivation by the inhibition of CTNNB1. The gene expression levels of PI3K, TP53 and catalase (CAT) in senescent and H2O2-treated cells were increased compared to young cells. CONCLUSION: p53 protein plays a key role in the aging of melanocytes via IGF1 signaling pathways.

H2O2 promotes the aging process of melanogenesis through modulation of MITF and Nrf2.

The purpose of this study is to investigate the effect of H2O2 on the aging of melanogenesis in human melanocytes. The staining of SA-ß-galactosidase, an aging marker, was remarkably increased in the cells aged with H2O2 at 62.5 µM or more compared with young cells. The intracellular H2O2 level and melanin synthesis were also reduced in both H2O2-treated cells and senescent cells compared with young cells in DCFH-DA assay. Both the senescent cells and the H2O2-treated cells showed higher expression level of Catalase than young cells in western blot and immunofluorescence staining. Furthermore, the expression levels of TRP-1, TRP-2 and p300 were reduced in both senescent cells and the H2O2-treated cells, but that of SIRT-1 was inverted compared with young cells. In addition, H2O2 reduced the expression level of MITF but increased that of Nrf2 in nucleus. Those results indicate that the expression levels of antioxidant enzymes in senescent cells and H2O2-treated cell are upregulated, but the expression levels of proteins involved in melanin synthesis are downregulated. Above findings suggest that H2O2 could play a key role in the aging process of melanogenesis through modulation of MITF and Nrf2.

Amentoflavone Induces Autophagy and Modulates p53.

OBJECTIVE: Amentoflavone is the main component of Selaginella tamariscina widely known as an oriental traditional medicinal stuff that has been known to have a variety of medicinal effects such as the induction of apoptosis, antimetastasis, and anti-inflammation. However, the effect of amentoflavone on autophagy has not been reported until now. The aim of this study was to investigate whether amentoflavone has a positive effect on the induction of autophagy related to cell aging. MATERIALS AND METHODS: In this experimental study, the aging of young cells was induced by the treatment with insulinlike growth factor-1 (IGF-1) at 50 ng/mL three times every two days. The effect of amentoflavone on the cell viability was evaluated in A549 and WI-38 cells using 3-(4,5-dimethyl-2-yl)-2,5- diphenyl tetrazolium bromide (MTT) assay. The induction of autophagy was detected using autophagy detection kit. The expression of proteins related to autophagy and IGF-1 signaling pathway was examined by western blot analysis and immunofluorescence assay. RESULTS: First of all, it was found that amentoflavone induces the formation of autophagosome. In addition, it enhanced the expression level of Atg7 and increased the expression levels of Beclin1, Atg3, and LC3 associated with the induction of autophagy in immunofluorescence staining and western blot analyses. Moreover, amentoflavone inhibited the cell aging induced by IGF-1 and hydrogen peroxide. In particular, the levels of p53 and p-p21 proteins were increased in the presence of amentoflavone. Furthermore, amentoflavone increased the level of SIRT1 deacetylating p53. CONCLUSION: Our results suggest that amentoflavone could play a positive role in the inhibition of various diseases associated with autophagy and the modulation of p53.

IGFBP-3 plays an important role in senescence as an aging marker.

Aging study requires aging markers to measure the degree of aging process. The aging markers such as senescence associated-ß-galactosidase (SA-ß-gal), lipofuscin, telomere, p53 and p16 have been known in aging study until now. Therefore, we investigated the role of genes and proteins related to aging in young, senescent and H2O2-induced old cells to develop a novel aging marker involved in aging mechanism. After cellular aging was compared in young, senescent and H2O2-induced old cells using SA-ß-galactosidase staining assay, the expression level of genes and proteins in senescent and H2O2-induced old cells were compared and analyzed with those of young cells using RT-PCR, western blot and immunofluorescence staining. First of all, the senescent cells and the cells aged by H2O2 showed higher level of SA-ß-galactosidase staining than young cells. In particular, the expression level of IGFBP-3 was decreased in senescent and H2O2-induced old cells compared with young cells. Moreover, the senescent and H2O2-induced old cells showed higher expression levels of p-PI3K, Akt-1, p-mTOR, p-FoxO1 and FoxO1 than young cells. Furthermore, the expression levels of p300, Ac-p53, p53, p-p21 and p16 were significantly increased in senescent and H2O2-induced cells compared to young cells. However, the expression level of SIRT-1 was decreased in senescent and H2O2-induced old cells compared to young cells. In conclusion, IGFBP-3 up-regulates PI3K/Akt/mTOR signaling pathway and down-regulates autophagy during cell aging. These results suggest that IGFBP-3 could play a key role in aging study as an important aging marker.

Pachymic acid promotes induction of autophagy related to IGF-1 signaling pathway in WI-38 cells.

BACKGROUND: The insulin-like growth factor 1 (IGF-1) signaling pathway has spotlighted as a mechanism to elucidate aging associated with autophagy in recent years. Therefore, we have tried to screen an effective compound capable of inducing autophagy to delay aging process. PURPOSE: The aim of this study is to investigate whether pachymic acid, a main compound in Poria cocos, induces autophagy in the aged cells. METHODS: The aging of young cells was induced by treatment with IGF-1 at 50 ng/ml three times every two days. The effect of pachymic acid on cell viability was evaluated in human lung fibroblasts, WI-38 cells, using MTT assay. The induction of autophagy was detected using autophagy detection kit. The expression of proteins related to autophagy and IGF-1 signaling pathway was examined by western blot analysis and immunofluorescence assay. RESULTS: In this study, pachymic acid showed cytotoxic effect in a dose dependent manner and remarkably induced autophagy at the same time. Moreover, pachymic acid increased the expression of proteins related to autophagy such as LC3-II and Beclin1 and decreased the levels of mTor phosphorylation and p70S6K in the aged cells. In particular, pachymic acid increased the expression of p-PI3K, p-FoxO and Catalase. In addition, pachymic acid remarkably increased the expression of IGFBP-3. CONCLUSION: Above results suggest that pachymic acid could induce autophagy related to IGF-1 signaling pathway in the aged cells.