• BMB Reports
• /
• v.51 no.10
• /
• pp.538-543
• /
• 2018

Pancreatic beta cell destruction and dysfunction induced by cytokines is a major cause of type 1 diabetes. Paraoxonase 1 (PON1), an arylesterase with antioxidant activity, has been shown to play an important role in preventing the development of diabetes in transgenic mice. However, no studies have examined the anti-diabetic effect of PON1 delivered to beta cells using protein transduction. In this study, we expressed the cell-permeable PON1 fused with PEP-1 protein transduction domain (PEP-1-PON1) to investigate whether transduced PEP-1-PON1 protects beta cells against cytokine-induced cytotoxicity. PEP-1-PON1 was effectively delivered to INS-1 cells and prevented cytokine-induced cell destruction in a dose-dependent manner. Transduced PEP-1-PON1 significantly reduced the levels of reactive oxygen species (ROS) and nitric oxide (NO), DNA fragmentation, and expression of inflammatory mediators, endoplasmic reticulum (ER) stress proteins, and apoptosis-related proteins in cytokine-treated cells. Moreover, transduced PEP-1-PON1 restored the decrease in basal and glucose-stimulated insulin secretion induced by cytokines. These data indicate that PEP-1-PON1 protects beta cells from cytokine-induced cytotoxicity by alleviating oxidative/nitrosative stress, ER stress, and inflammation. Thus, PEP-1-mediated PON1 transduction might be an effective method to reduce the extent of destruction and dysfunction of pancreatic beta cells in autoimmune diabetes.

• Archives of Pharmacal Research
• /
• v.26 no.7
• /
• pp.559-563
• /
• 2003

Cytokines produced by immune cells infiltrating pancreatic islets have been incriminated as important mediators of $\beta$-cell destruction in insulin-dependent diabetes mellitus. In non insulin-dependent diabetes, cytokines are also associated with impaired $\beta$-cell function in high glucose condition. By the screening of various natural products blocking $\beta$-cell destruction, we have recently found that epigallocatechin gallate (EGCG) can prevent the in vitro destruction of RINm5F cell, an insulinoma cell line, that is induced by cytokines. In that study we suggested that EGCG could prevent cytokine-induced $\beta$-cell destruction by down-regulation of nitric oxide synthase (NOS) through inhibition of NF-kB activation. Here, to verify the in vivo antidiabetogenic effect of EGCG, we examined the possibility that EGCG could also prevent the experimental autoimmune diabetes induced by the treatment of multiple low doses of streptozotocin (MLD-STZ), which is recognized as an inducer of type I autoimmune diabetes. Administration of EGCG (100 mg/day/kg for 10 days) during the MLD-STZ induction of diabetes reduced the increase of blood glucose levels caused by MLD-STZ. Ex vivo analysis of $\beta$-islets showed that EGCG downregulates the MLD-STZ-induced expression of inducible NOS (iNOS). In addition, morphological examination showed that EGCG treatment ameliorated the decrease of islet mass induced by MLD-STZ. In combination these results suggest that EGCG could prevent the onset of MLD-STZ-induced diabetes by protecting pancreatic islets. Our results therefore revealed the possible therapeutic value of EGCG for the prevention of diabetes mellitus progression.

• Archives of Pharmacal Research
• /
• v.22 no.5
• /
• pp.437-447
• /
• 1999

Type I diabetes, also known as insulin-dependent diabetes mellitus (IDDM) results from the destruction of insulin-producing pancreatic $\beta$ cells by a progressive $\beta$ cell-specific autoimmune process. The pathogenesis of autoimmune IDDM has been extensively studied for the past two decades using animal models such as the non-obese diabetic (NOD) mouse and the Bio-Breeding (BB) rat. However, the initial events that trigger the immune responses leading to the selective destruction of the $\beta$ cells are poorly understood. It is thought that $\beta$ cell auto-antigens are involved in the triggering of $\beta$ cell-specific autoimmunity. Among a dozen putative $\beta$ cell autoantigens, glutamic acid decarboxylase (GAD) has bee proposed as perhaps the strongest candidate in both humans and the NOD mouse. In the NOD mouse, GAD, as compared with other $\beta$ cell autoantigens, provokes the earliest T cell proliferative response. The suppression of GAD expression in the $\beta$ cells results in the prevention of autoimmune diabetes in NOD mice. In addition, the major populations of cells infiltrating the iselts during the early stage of insulitis in BB rats and NOD mice are macrophages and dendritic cells. The inactivation of macrophages in NOD mice results in the prevention of T cell mediated autoimmune diabetes. Macrophages are primary contributors to the creation of the immune environment conducive to the development and activation of $\beta$cell-specific Th1-type CD4+ T cells and CD8+ cytotoxic T cells that cause autoimmune diabetes in NOD mice. CD4+ and CD8+ T cells are both believed to be important for the destruction of $\beta$ cells. These cells, as final effectors, can kill the insulin-producing $\beta$ cells by the induction of apoptosis. In addition, CD8+ cytotoxic T cells release granzyme and cytolysin (perforin), which are also toxic to $\beta$ cells. In this way, macrophages, CD4+ T cells and CD8+ T cells act synergistically to kill the $\beta$ cells in conjunction with $\beta$ cell autoantigens and MHC class I and II antigens, resulting in the onset of autoimmune type I diabetes.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.16
• /
• pp.7277-7284
• /
• 2015

Background: The Wnt/${\beta}$-catenin signaling pathway is an important regulator of cellular functions such as proliferation, survival and cell adhesion. Wnt/${\beta}$-catenin signaling is associated with tumor initiation and progression; ${\beta}$-catenin mutations explain only 30% of aberrant signaling found in breast cancer, indicating that other components and/or regulation of the Wnt/${\beta}$-catenin pathway may be involved. Objective: We evaluated AXIN2 rs2240308 and rs151279728 polymorphisms, and expression profiles of ${\beta}$-catenin destruction complex genes in breast cancer patients. Materials and Methods: We collected peripheral blood samples from 102 breast cancer and 102 healthy subjects. The identification of the genetic variation was performed using PCR-RFLPs and DNA sequencing. RT-qPCR was used to determine expression profiles. Results: We found significant association of AXIN2 rs151279728 and rs2240308 polymorphisms with breast cancer risk. Significant increase was observed in AXIN2 level expression in breast cancer patients. Further analyses showed APC, ${\beta}$-catenin, CK1${\alpha}$, GSK3${\beta}$ and PP2A gene expression to be associated to clinic-pathological characteristics. Conclusions: The present study demonstrated, for the first time, that AXIN2 genetic defects and disturbance of ${\beta}$-catenin destruction complex expression may be found in breast cancer patients, providing additional support for roles of Wnt/${\beta}$-catenin pathway dysfunction in breast cancer tumorigenesis. However, the functional consequences of the genetic alterations remain to be determined.

• Proceedings of the PSK Conference
• /
• 2000.10a
• /
• pp.108-108
• /
• 2000

• YAKHAK HOEJI
• /
• v.41 no.2
• /
• pp.260-267
• /
• 1997

To establish prediabetes in vitro model concerning the etiology of IDDM(Insulin Dependent Diabetes Mellitus) in cellular level we have designed prediabetes in vitro models in pa ncreatic beta cells. HIT-T15, RINm5F and isolated rat islets were chosen as pancreatic beta cells, and streptozotocin (STZ) used as diabetogenic agent. Degree of beta cell destruction to establish prediabetic in vitro model was determined by cell proliferation and insulin release using thymidine uptake and radio immuno assay. When HIT-T15 and RINm5F cells were treated with STZ, the degree of cell deterioration was dependent upon the origin and passage number of beta cells, and in the case of isolated islets STZ showed the more sensitivity than above two beta cell lines. The concentration and exposure time of STZ treatment to establish prediabetes in vitro model in beta cell lines and isolated rat islets were 2 ~ 10mM, 30 min. and 1 ~ 5mM, 30 min., respectively.

• Advances in Traditional Medicine
• /
• v.5 no.4
• /
• pp.251-261
• /
• 2005

Rheumatoid arthritis (RA) is an autoimmune/inflammatory disorder with a complex genetic component. RA is characterized by chronic inflammation of the synovial membrane in the joint, which leads to the progressive destruction of articular cartilage, ligament and bone. Several cytokines such as tumor necrosis $factor-{\alpha}\;TNF-{\alpha}\;and\;interleukin-1{\beta}\;(IL-1{\beta})$ and interleukin-6 (IL-6) have been implicated in the pathological mechanisms of synovial tissue proliferation, joint destruction and programmed cell death in rheumatoid joint. Genome wide screening of subjects suffering from autoimmune diseases especially arthritis revealed linkage to inflammatory molecules like $TNF-{\alpha},\;IL-1{\beta}$ and IL-6, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-kappaB $(NF-{\kappa}B)$ and human leucocyte antigen/major histocompatibility complex (HLA/MHC) locus. The status of the pharmacological mechanism of herbal drugs in the light of genome wide screening results has been discussed to reinforce the therapeutic potential and the pharmacological basis of the herbal drugs.

• The Korean Journal of Physiology and Pharmacology
• /
• v.7 no.3
• /
• pp.163-168
• /
• 2003

The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic ${\beta}$ cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu,Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ)-induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic ${\beta}$ cell destruction in ROS-mediated diabetes.

• Journal of Acupuncture Research
• /
• v.19 no.5
• /
• pp.136-148
• /
• 2002

본 연구는 osteoblastic cells에서 estogen 의 생합성을 유도하는 aromatase의 activity에 대한 봉독(蜂毒)작용을 측정하여, 봉독치료시 Arthritis의 진행 억제 및 estogen의 의한 bone formation의 효과여부를 검증하기 위해 실행하였다. 사용된 세포주로는 Osteoblastic phenotype으로 분화가 유도되는 Human leukaemic cell line FLG 29.1 및 the primary first-passage osteoblastic cells (hOB cells)이며, 이들을 각각 배양하고 각각의 RNA를 isolation한 뒤 PCR 증폭을 하였다. Aromatase에 대한 활성인자인 TPA와 TGF-${\beta}1$ 및 봉독을 이용하여 aromatase의 expression 및 activity에 대해 미치는 영향을 측정한 바, aromatase expression은 FLG 29.1 cell와 hoB cells에서, 50nM TPA 24시간 처리, 봉독 2 ~ 4시간 처리와 TGF-${\beta}1$ 3시간 처리로 유도한 결과 TPA와 TGF-${\beta}1$의 경우는 서로 유사하였고, 봉독에서 상대적으로 높게 나타났다. Aromatase activity는 FLG 29.1 cell, hoB cells에서 24시간 incubation한 결과, 모든 실험에서 일정하게 선상증가를 보였다. $5{\mu}{\ell}/m{\ell}$ BV에서 TPA와 TGF-${\beta}1$보다 뚜렷하게 증가하였으며, 0.5mM Bt2-cAMP, 50nM dexametasone처리에서는 유의성이 없었다. Estrogen 생합성을 촉매하는 aromatase activity BV가 처리에서 현저하게 증가하였기에, Rheumatis arthritis의 bone destruction에 대해 BV가 효과적인 역할을 할 것으로 보여진다.

• Journal of Periodontal and Implant Science
• /
• v.35 no.1
• /
• pp.99-109
• /
• 2005

It has been focused on the importance of the host inflammatory response in periodontal pathogenesis and progression, treatment has been introduced to control the host response and the method, which diminishes production and activity of MMP by doxycycline, has been used in periodontal field. MMP is a proteolytic enzyme which plays a major role in tissue destruction and MMP-1 is secreted in the periodontally healthy tissue, while MMP-8, 9, 13, etc in the inflammatory state. Among these, MMP-13 has been discovered lately and reported to degrade primarily type II collagen. Periodontal ligament (PDL) cell plays a role in destruction of periodontal tissue. This study was to evaluate the effect of doxycycline and mefenamic acid, non-steroidal antiinflammatory drug on MMP-13 mRNA expression in the rat PDL cell. Doxycycline concentration of $1{\sim}100\;{\mu}g/ml$ was added rat PDL cell and cell activity was measured by MIT assay at day 1 and 3. MMP-13 gene expression was evaluated by RT-PCR after PDL cells were pre-treated for 1hour with doxycycline (50 ${\mu}g/ml$) alone or with mefenamic acid ($10^{-6}M$), then added $IL-1{\beta}$(1.0 ng/ml) and incubated for 16-18 hours. The results are as follows: 1. Cell activity decreased Significantly at 24 and 72 hours in 100 ${\mu}g/ml$ (p<0.05). 2. Level of MMP-13 mRNA was in 20.2% increase by $IL-1{\beta}$ and in pre-treating doxycycline group, expression of $IL-1{\beta}$ induced MMP-13 mRNA was inhibited by 31% than $IL-1{\beta}$ treated only. 3. Mefenamic acid did not inhibit on the expression of $IL-1{\beta}$ induced MMP-13 mRNA, while mefenamic acid in combination with doxycycline inhibited the expression by 41% compared to only $IL-1{\beta}$ stimulation. These results suggest that doxycycline synergistically inhibit the expression of $IL-1{\beta}$ induced MMP-13 mRNA in combination with mefenamic acid.