104 research outputs found
Tumor Suppressor CYLD Acts as a Negative Regulator for Non-Typeable Haemophilus influenza-Induced Inflammation in the Middle Ear and Lung of Mice
Non-typeable Haemophilus influenza (NTHi) is an important human pathogen causing respiratory tract infections in both adults and children. NTHi infections are characterized by inflammation, which is mainly mediated by nuclear transcription factor kappaB (NF-κB)-dependent production of inflammatory mediators. The deubiquitinating enzyme cylindromatosis (CYLD), loss of which was originally reported to cause a benign human syndrome called cylindromatosis, has been identified as a key negative regulator for NF-κB in vitro. However, little is known about the role of CYLD in bacteria-induced inflammation in vivo. Here, we provided direct evidence for the negative role of CYLD in NTHi-induced inflammation of the mice in vivo. Our data demonstrated that CYLD is induced by NTHi in the middle ear and lung of mice. NTHi-induced CYLD, in turn, negatively regulates NTHi-induced NF-κB activation through deubiquitinating TRAF6 and 7 and down-regulates inflammation. Our data thus indicate that CYLD acts as a negative regulator for NF-κB-dependent inflammation in vivo, hence protecting the host against detrimental inflammatory response to NTHi infection
MEF/ELF4 transactivation by E2F1 is inhibited by p53
Myeloid elf-1-like factor (MEF) or Elf4 is an E-twenty-six (ETS)-related transcription factor with strong transcriptional activity that influences cellular senescence by affecting tumor suppressor p53. MEF downregulates p53 expression and inhibits p53-mediated cellular senescence by transcriptionally activating MDM2. However, whether p53 reciprocally opposes MEF remains unex-plored. Here, we show that MEF is modulated by p53 in human cells and mice tissues. MEF expression and promoter activity were suppressed by p53. While we found that MEF promoter does not contain p53 response elements, intriguingly, it contains E2F consensus sites. Subsequently, we determined that E2F1 specifically binds to MEF promoter and transactivates MEF. Nevertheless, E2F1 DNA binding and transactivation of MEF promoter was inhibited by p53 through the association between p53 and E2F1. Furthermore, we showed that activation of p53 in doxorubicin-induced senescent cells increased E2F1 and p53 interaction, diminished E2F1 recruitment to MEF promoter and reduced MEF expression. These observations suggest that p53 downregulates MEF by associating with and inhibiting the binding activity of E2F1, a novel transcriptional activator of MEF. Together with previous findings, our present results indicate that a negative regulatory mechanism exists between p53 and MEF
Posttranslational negative regulation of glycosylated and non-glycosylated BCRP expression by Derlin-1
Human breast cancer resistance protein (BCRP)/MXR/ABCG2 is a well-recognized ABC half-transporter that is highly expressed at the apical membrane of many normal tissues and cancer cells. BCRP facilitates disposition of endogenous and exogenous harmful xenobiotics to protect cells/tissues from xenobiotic-induced toxicity. Despite the enormous impact of BCRP in the physiological and pathophysiological regulation of the transport of a wide variety of substrates, little is known about the factors that regulate posttranslational expression of BCRP. Here, we identified Derlin-1, a member of a family of proteins that bears homology to yeast Der1p, as a posttranslational regulator of BCRP expression. Overexpression of Derlin-1 suppressed ER to Golgi transport of wild-type (WT) BCRP that is known to be efficiently trafficked to the plasma membrane. On the other hand, protein expression of N596Q variant of BCRP, N-linked glycosylation- deficient mutant that preferentially undergoes ubiquitin-mediated ER-associated degradation (ERAD), was strongly suppressed by the overexpression of Derlin-1, whereas knockdown of Derlin-1 stabilized N596Q protein, suggesting a negative regulatory role of Derlin-1 for N596Q protein expression. Notably, knockdown of Derlin-1 also stabilized the expression of tunicamycin-induced deglycosylated WT BCRP protein, implying the importance of glycosylation state for the recognition of BCRP by Derlin- 1. Thus, our data demonstrate that Derlin-1 is a negative regulator for both glycosylated and non-glycosylated BCRP expression and provide a novel posttranslational regulatory mechanism of BCRP by Derlin-1
Mild electrical stimulation with heat shock guides differentiation of embryonic stem cells into Pdx1-expressing cells within the definitive endoderm
Inhibition of NK cell activity by IL-17 allows vaccinia virus to induce severe skin lesions in a mouse model of eczema vaccinatum
Threats of bioterrorism have renewed efforts to better understand poxvirus pathogenesis and to develop a safer vaccine against smallpox. Individuals with atopic dermatitis are excluded from smallpox vaccination because of their propensity to develop eczema vaccinatum, a disseminated vaccinia virus (VACV) infection. To study the underlying mechanism of the vulnerability of atopic dermatitis patients to VACV infection, we developed a mouse model of eczema vaccinatum. Virus infection of eczematous skin induced severe primary erosive skin lesions, but not in the skin of healthy mice. Eczematous mice exhibited lower natural killer (NK) cell activity but similar cytotoxic T lymphocyte activity and humoral immune responses. The role of NK cells in controlling VACV-induced skin lesions was demonstrated by experiments depleting or transferring NK cells. The proinflammatory cytokine interleukin (IL)-17 reduced NK cell activity in mice with preexisting dermatitis. Given low NK cell activities and increased IL-17 expression in atopic dermatitis patients, these results can explain the increased susceptibility of atopic dermatitis patients to eczema vaccinatum
Development of Kupffer cell targeting type-I interferon for the treatment of hepatitis via inducing anti-inflammatory and immunomodulatory actions
Because of its multifaceted anti-inflammatory and immunomodulatory effects, delivering type-I interferon to Kupffer cells has the potential to function as a novel type of therapy for the treatment of various types of hepatitis. We report herein on the preparation of a Kupffer cell targeting type-I interferon, an albumin-IFNα2b fusion protein that contains highly mannosylated N-linked oligosaccharide chains, Man-HSA(D494N)-IFNα2b, attached by combining albumin fusion technology and site-directed mutagenesis. The presence of this unique oligosaccharide permits the protein to be efficiently, rapidly and preferentially distributed to Kupffer cells. Likewise IFNα2b, Man-HSA(D494N)-IFNα2b caused a significant induction in the mRNA levels of IL-10, IL-1Ra, PD-L1 in RAW264.7 cells and mouse isolated Kupffer cells, and these inductions were largely inhibited by blocking the interferon receptor. These data indicate that Man-HSA(D494N)-IFNα2b retained the biological activities of type-I interferon. Man-HSA(D494N)-IFNα2b significantly inhibited liver injury in Concanavalin A (Con-A)-induced hepatitis model mice, and consequently improved their survival rate. Moreover, the post-administration of Man-HSA(D494N)-IFNα2b at 2 h after the Con-A challenge also exerted hepato-protective effects. In conclusion, this proof-of-concept study demonstrates the therapeutic effectiveness and utility of Kupffer cell targeting type-I interferon against hepatitis via its anti-inflammatory and immunomodulatory actions
健康への配慮とメタボリックシンドローム対策状況について -佐世保市民の健康に関する実態調査報告-
本研究では、健康への意識の有無とメタボリックシンドローム(以下、MetS)予防および改善行動の実践の有無から分析を行い、意識や行動の違いが健康に関する項目にどのような影響を与えるのか検討を行った。その結果、健康への意識を持つことにより日常的に健康の維持増進に向けた生活習慣を送り、健康診断やがん検診の受診など健康に向けた望ましい行動や、共食日数の増加や余暇活動の増加など QOL の向上にもつながることが示唆された。また、健康を意識することに加えて MetS 予防を行っているものでは、さらに望ましい生活習慣状況となっており、MetS 予防といった明確な目的およびその対策を実践しているという自覚によってより一層健康的な日常生活の実践に結びついていることが考えられた。In the present study, we analyzed the data from the presence or absence of the awareness of health and from the presence or absence of the practice for prevention of metabolic syndrome(hereinafter called“MetS”)and the behavior for improvement, and examined what effect the differences in the awareness and behavior might influence on the items on health. As a result, it was suggested that, by having an awareness of health, it would be possible to establish a life-style enabling the maintenance and promotion of health, and to be linked to the desirable behavior for health such as having regularly a health check-up and a cancer examination, and to go far towards the advancement of QOL such as the increased number of days of‘eating in company\u27and the increased level of activity for leisure. In addition to having an awareness of health, those who were conducting the preventive measure against MetS were found to lead a more, desirable life-style, and to be related to the practice of a healthier daily life by becoming self-conscious of having a definite objective of preventing MetS and practicing its measure
休養状況から見た健康に向けた実践状況 -佐世保市民の健康に関する実態調査報告-
健康づくりの要素として「栄養・食生活」「身体活動・運動」「休養・こころの健康づくり」の3本柱があげられるが、本報告では佐世保市において平成24年1月~2月に行われた「佐世保市民の健康に関する実態調査」の調査結果のうち、休養状況を示す「休養・こころの健康づくり」に着目をし、休養と健康についての分析を行った。その結果、日常的に健康に配慮しているもの及び配慮している生活習慣として「栄養・食生活」を挙げた者が最も多く、「休養」をあげた者の割合は、「栄養・食生活」「運動」に対して少なかった。「運動」を挙げた者は休養がとれている者ととれていない者との差が大きく、また、休養がとれている者は、積極的に身体を動かしていたことを示した。休養を適切にとることは、日常生活が健康的な生活につながることを示唆した。しかし、休養が健康の3本柱でありながら、健康のために配慮することとして休養は考えられにくい状況であったことから、休養と健康とのつながりについて周知していくことが必要となると考える。It is thought that“nutrition and dietary life”,“physical activity and exercise”and“rest and mental health promotion”are the most important factors for health promotion. Previously, we made a survey on actual conditions of health for people living in Sasebo in a period from January to February of 2012. Based on results of the survey, an analysis was made on a rest and health paying attention to the results of“rest and mental health promotion”, which indicates the situation of people\u27s rest. The number of people usually paying attention to own health and those who chose the item“nutrition and dietary life”as their important life habit was the most. Whereas the number of subjects who chose the item“rest”was less than the number of subjects who chose the item“nutrition and dietary life”or“exercise”. Regarding the subjects who chose the item of exercise, there was a large difference between the numbers of subjects taking a rest enough and those who were not. Moreover, the present findings suggested that physical activity of people taking a rest enough is mostly high. These results suggest that to take an appropriate rest would lead to healthy life. “Rest”is one of three indispensable factors to keep health and so it is important to be concerned about“rest”for health maintenance. However, such idea was not so widely received until recently and“rest”was apt to be disregarded. Therefore, it is thought necessary to widely spread the idea about close correlation between rest and health
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