• IMMUNE NETWORK
• /
• v.20 no.6
• /
• pp.51.1-51.17
• /
• 2020

Respiratory syncytial virus (RSV) causes severe pulmonary disease in infants, young children, and the elderly. Formalin inactivated RSV (FI-RSV) vaccine trials failed due to vaccine enhanced respiratory disease, but the underlying immune mechanisms remain not fully understood. In this study, we have used wild type C57BL/6 and CD4 knockout (CD4KO) mouse models to better understand the roles of the CD4 T cells and cellular mechanisms responsible for enhanced respiratory disease after FI-RSV vaccination and RSV infection. Less eosinophil infiltration and lower pro-inflammatory cytokine production were observed in FI-RSV vaccinated CD4KO mice after RSV infection compared to FI-RSV vaccinated C57BL/6 mice. NK cells and cytokine-producing CD8 T cells were recruited at high levels in the airways of CD4KO mice, correlating with reduced respiratory disease. Depletion studies provided evidence that virus control was primarily mediated by NK cells whereas CD8 T cells contributed to IFN-γ production and less eosinophilic lung inflammation. This study demonstrated the differential roles of effector CD4 and CD8 T cells as well as NK cells, in networking with other inflammatory infiltrates in RSV disease in immune competent and CD4-deficient condition.

• Journal of Life Science
• /
• v.20 no.4
• /
• pp.555-560
• /
• 2010

The objective of this study was to investigate levels of serum creatinine, CuSOD and MnSOD protein expression in the kidney after renal ischemic reperfusion with pre-exercise using heat shock protein 70.1 in knock-out mice (KO). The C57/BL6 strain (Wild type: WT) and KO were divided into 4 groups as follows: Sham control group (Sham), pre-exercise group (Ex), pre-exercise +ischemia group (Ex+IR), and ischemia group (IR). CuSOD and MnSOD expression were significantly decreased (p<0.01, p<0.05) and blood creatinine concentration was significantly increased (p<0.01) in the IR group of KO. In contrast, CuSOD and MnSOD expression in the Ex+IR group of KO were higher than the IR group, while creatinine concentration was significantly lower. These results suggest that Hsp70 is directly correlated to renal ischemic reperfusion injury. Pre-exercise in renal ischemia might prevent or inhibit positive oxidative stress inhibitory effects by increasing anti-oxidative enzymes (CuSOD, MnSOD) within the kidney and improve to prevent renal function. Thus, pre-exercise may have a protective role against renal injury after renal ischemia.

• Journal of Life Science
• /
• v.18 no.8
• /
• pp.1173-1176
• /
• 2008

Individuals who regularly consume excessive quantities of alcohol are at a greater risk of developing various cancers such as esophageal, pharyngeal and lung cancers compared to normal populations if they are deficient in ALDH2 enzyme activity. We evaluated oxidative DNA damage in the liver, brain, and lung tissues of Aldh2 +/+ and Aldh2 -/- mice after they had been subjected to acute ethanol exposure. The 8-hydroxydeoxyguanosine (8-OHdG) level in each tissue was evaluated as a biomarker of oxidative DNA damage. The 8-OHdG level in the liver, brain, and lung tissues was significantly increased following ethanol treatment. In addition, the level of 8-OHdG in the liver and lung tissues was affected by ALDH2 enzyme activity. This result suggests that ALDH2-deficient individuals may be more susceptible than wild-type ALDH2 individuals to ethanol-mediated diseases, including cancer.

• Journal of Life Science
• /
• v.26 no.5
• /
• pp.531-536
• /
• 2016

We previously showed that NAD(P)H:quinone oxidoreductase 1 (NQO1) knockout (KO) mice exhibited spontaneous inflammation with markedly increased mucosal permeability in the gut, and that NQO1 is functionally associated with regulating tight junctions in the mucosal epithelial cells that govern the mucosal barrier. Here, we confirm the role of NQO1 in the formation of tight junctions by human colonic epithelial cells (HT29). We treated HT29 cells with a chemical inhibitor of NQO1 (dicumarol; 10 μM), and examined the effect on the transepithelial resistance of epithelial cells and the protein expression levels of ZO1 and occludin (two known regulators of tight junctions between gut epithelial cells). The dicumarol-induced inhibition of NQO1 markedly reduced transepithelial resistance (a measure of tight junctions) and decreased the levels of the tested tight junction proteins. In vivo, luminal injection of dicumarol significantly increased mucosal permeability and decreased ZO1 and occludin protein expression levels in mouse guts. However, in contrast to the previous report that the epithelial cells of NQO1 KO mice showed marked down-regulations of the transcripts encoding ZO1 and occludin, these transcript levels were not affected in dicumarol-treated HT29 cells. This result suggests that the NQO1-depedent regulation of tight junction molecules may involve multiple processes, including both transcriptional regulation and protein degradation processes such as those governed by the ubiquitination/proteasomal, and/or lysosomal systems.

• Journal of Life Science
• /
• v.19 no.9
• /
• pp.1232-1238
• /
• 2009

Neurotransmitter release is regulated by various proteins of the active zone in the presynaptic nerve terminals. Dopamine (DA) is an essential neurotransmitter associated with the pathophysiology of diverse behavioral and mental illness such as schizophrenia and drug addiction. We measured synaptosomal DA release of knockout (KO) mice which lacked major genes related to neurotransmitter release. Synaptosomal DA uptake and release were performed and measured using [$^3H$]-DA and superfusion experiments. 3 of the 17 KO mice exhibited altered DA release compared to their littermate controls. In $Rim1{\alpha}$ KO, [$^3H$]-DA release evoked by membrane depolarization significantly decreased. Both basal (physiological buffer-evoked) and membrane depolarization-evoked DA release significantly decreased in dopaminergic conditional KO of $Rim1{\alpha}{\beta}$. Dopaminergic conditional KO of neurexin3 demonstrated a significant increase of membrane depolarization-evoked DA release. These data explain the similarities and distinctions between DA and other classical neurotransmitters such as glutamate and GABA ($\gamma$-aminobutyric acid) release. In conclusion, $Rim1{\alpha}$ and neurexin3 may be important regulators of presynaptic DA release and related to disorders of the nervous system.

• Molecules and Cells
• /
• v.40 no.2
• /
• pp.123-132
• /
• 2017

Insulin signaling is coordinated by insulin receptor substrates (IRSs). Many insulin responses, especially for blood glucose metabolism, are mediated primarily through Irs-1 and Irs-2. Irs-1 knockout mice show growth retardation and insulin signaling defects, which can be compensated by other IRSs in vivo; however, the underlying mechanism is not clear. Here, we presented an Irs-1 truncated mutated mouse ($Irs-1^{-/-}$) with growth retardation and subcutaneous adipocyte atrophy. $Irs-1^{-/-}$ mice exhibited mild insulin resistance, as demonstrated by the insulin tolerance test. Phosphatidylinositol 3-kinase (PI3K) activity and phosphorylated Protein Kinase B (PKB/AKT) expression were elevated in liver, skeletal muscle, and subcutaneous adipocytes in Irs-1 deficiency. In addition, the expression of IRS-2 and its phosphorylated version were clearly elevated in liver and skeletal muscle. With miRNA microarray analysis, we found miR-33 was down-regulated in bone marrow stromal cells (BMSCs) of $Irs-1^{-/-}$ mice, while its target gene Irs-2 was up-regulated in vitro studies. In addition, miR-33 was down-regulated in the presence of Irs-1 and which was up-regulated in fasting status. What's more, miR-33 restored its expression in re-feeding status. Meanwhile, miR-33 levels decreased and Irs-2 levels increased in liver, skeletal muscle, and subcutaneous adipocytes of $Irs-1^{-/-}$ mice. In primary cultured liver cells transfected with an miR-33 inhibitor, the expression of IRS-2, PI3K, and phosphorylated-AKT (p-AKT) increased while the opposite results were observed in the presence of an miR-33 mimic. Therefore, decreased miR-33 levels can up-regulate IRS-2 expression, which appears to compensate for the defects of the insulin signaling pathway in Irs-1 deficient mice.

• Journal of Ginseng Research
• /
• v.46 no.4
• /
• pp.561-571
• /
• 2022

Background: Ginsenoside Rb1 (GRb1) is capable of regulating lipid and glucose metabolism through its action on adipocytes. However, the beneficial role of GRb1-induced up-regulation of adiponectin in liver steatosis remains unelucidated. Thus, we tested whether GRb1 ameliorates liver steatosis and insulin resistance by promoting the expression of adiponectin. Methods: 3T3-L1 adipocytes and hepatocytes were used to investigate GRb1's action on adiponectin expression and triglyceride (TG) accumulation. Wild type (WT) mice and adiponectin knockout (KO) mice fed high fat diet were treated with GRb1 for 2 weeks. Hepatic fat accumulation and function as well as insulin sensitivity was measured. The activation of AMPK was also detected in the liver and hepatocytes. Results: GRb1 reversed the reduction of adiponectin secretion in adipocytes. The conditioned medium (CM) from adipocytes treated with GRb1 reduced TG accumulation in hepatocytes, which was partly attenuated by the adiponectin antibody. In the KO mice, the GRb1-induced significant decrease of TG content, ALT and AST was blocked by the deletion of adiponectin. The elevations of GRb1-induced insulin sensitivity indicated by OGTT, ITT and HOMA-IR were also weakened in the KO mice. The CM treatment significantly enhanced the phosphorylation of AMPK in hepatocytes, but not GRb1 treatment. Likewise, the phosphorylation of AMPK in liver of the WT mice was increased by GRb1, but not in the KO mice. Conclusions: The up-regulation of adiponectin by GRb1 contributes to the amelioration of liver steatosis and insulin resistance, which further elucidates a new mechanism underlying the beneficial effects of GRb1 on obesity.

• IMMUNE NETWORK
• /
• v.20 no.5
• /
• pp.40.1-40.15
• /
• 2020

The protein encoded by the Gene Associated with Retinoid-Interferon-Induced Mortality-19 (GRIM-19) is located in the mitochondrial inner membrane and is homologous to the NADH dehydrogenase 1-alpha subcomplex subunit 13 of the electron transport chain. Multiple sclerosis (MS) is a demyelinating disease that damages the brain and spinal cord. Although both the cause and mechanism of MS progression remain unclear, it is accepted that an immune disorder is involved. We explored whether GRIM-19 ameliorated MS by increasing the levels of inflammatory cytokines and immune cells; we used a mouse model of experimental autoimmune encephalomyelitis (EAE) to this end. Six-to-eight-week-old male C57BL/6, IFNγ-knockout (KO), and GRIM-19 transgenic mice were used; EAE was induced in all strains. A GRIM-19 overexpression vector (GRIM19 OVN) was electrophoretically injected intravenously. The levels of Th1 and Th17 cells were measured via flow cytometry, immunofluorescence, and immunohistochemical analysis. IL-17A and IFNγ expression levels were assessed via ELISA and quantitative PCR. IL-17A expression decreased and IFNγ expression increased in EAE mice that received injections of the GRIM-19 OVN. GRIM19 transgenic mice expressed more IFNγ than did wild-type mice; this inhibited EAE development. However, the effect of GRIM-19 overexpression on the EAE of IFNγ-KO mice did not differ from that of the empty vector. GRIM-19 expression was therapeutic for EAE mice, elevating the IFNγ level. GRIM-19 regulated the Th17/Treg cell balance.

• Journal of Life Science
• /
• v.30 no.6
• /
• pp.513-521
• /
• 2020

B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi1) is a polycomb group protein and a core component of polycomb repressive complex 1. Initial research into Bmi1 has focused on its role in tumorigenesis, and it is generally accepted that it is important for the proliferation and survival of cancer cells. However, more recent studies have revealed that Bmi1 is downregulated in brains with neurodegenerative disease and that it regulates the function of mitochondria and reactive oxygen species levels. In this study, we tested the therapeutic potential of Bmi1 in pilocarpine-induced seizures in Bmi1-knockout mice. Bmi1 expression transiently increased in the hippocampal CA1 and CA3 and the dentate gyrus following pilocarpine-induced status epilepticus (SE). In terms of seizure behavior, SE induction was 43.14% and 53.57% for Bmi1^+/+ and Bmi1^+/- mice, respectively. However, there was no significant difference in mortality or hippocampal damage between the two groups. Two months after SE induction, the frequency of epileptic seizures in the Bmi1^+/- mice was 50% lower than in the control group, although the difference was not statistically significant. In addition, mossy fiber outgrowth in the Bmi1^+/- mice was significantly higher than in their wild-type littermates. Taken together, these data indicate that reduced Bmi1 activity increases pilocarpine-induced seizure probability and mossy fiber outgrowth.

• Pediatric Infection and Vaccine
• /
• v.20 no.3
• /
• pp.123-130
• /
• 2013

Purpose: Subacute sclerosing panencephalitis (SSPE) is a neurodegerative disease due to persistent measles virus infection. We investigated the role of programmed death-1 (PD-1) molecule which is related with chronic viral infection in developing SSPE in mouse. Methods: We adopt the $PD-1^{-/-}$, $PD-1^{-/+}$, and wild type BALB/c 3 week old mice to make an animal model of SSPE by injecting measles virus (SSPE strain) intraventricularly. Three months after infusion of virus, the mice were sacrificed and examined if the typical pathologic lesions had been progressed. The sera were collected from each group of mice and the serum level of IL-21 was measured with ELISA kit. Results: The necrotic lesions on white matter and gliosis were found in focal areas in wild type BALB/c. The extent of lesion was smaller in heterotype BALB/c. Scanty lesions were found in $PD-1^{-/-}$ mice. The sera level of IL-21 was not elevated in all three groups. Conclusion: Our data suggest that the PD-1 molecule may play a role in persistent viral infection.