Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disorder in obese individuals. Adenine nucleotide translocase (ANT) exchanges ADP/ATP through the mitochondrial inner membrane, and ...Ant2 is the predominant isoform expressed in the liver. Here we demonstrate that targeted disruption of Ant2 in mouse liver enhances uncoupled respiration without damaging mitochondrial integrity and liver functions. Interestingly, liver specific Ant2 knockout mice are leaner and resistant to hepatic steatosis, obesity and insulin resistance under a lipogenic diet. Protection against fatty liver is partially recapitulated by the systemic administration of low-dose carboxyatractyloside, a specific inhibitor of ANT. Targeted manipulation of hepatic mitochondrial metabolism, particularly through inhibition of ANT, may represent an alternative approach in NAFLD and obesity treatment.
Malaria is a mosquito-borne infectious disease caused by the parasite Plasmodium spp. Malaria continues to have a devastating impact on human health. Sporozoites are the infective forms of the ...parasite inside mosquito salivary glands. Circumsporozoite protein (CSP) is a major and immunodominant protective antigen on the surface of Plasmodium sporozoites. Here, we report a generation of specific monoclonal antibodies that recognize the central repeat and C-terminal regions of P. falciparum CSP. The monoclonal antibodies 3C1, 3C2, and 3D3—specific for the central repeat region—have higher titers and protective efficacies against challenge with sporozoites compared with 2A10, a gold standard monoclonal antibody that was generated in early 1980s.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Transport of ADP and ATP across mitochondria is one of the primary points of regulation to maintain cellular energy homeostasis. This process is mainly mediated by adenine nucleotide translocase ...(ANT) located on the mitochondrial inner membrane. There are four human ANT isoforms, each having a unique tissue-specific expression pattern and biological function, highlighting their potential as drug targets for diverse clinical indications, including male contraception and cancer. In this study, we present a novel yeast-based high-throughput screening (HTS) strategy to identify compounds inhibiting the function of ANT. Yeast strains generated by deletion of endogenous proteins with ANT activity followed by insertion of individual human ANT isoforms are sensitive to cell-permeable ANT inhibitors, which reduce proliferation. Screening hits identified in the yeast proliferation assay were characterized in ADP/ATP exchange assays employing recombinant ANT isoforms expressed in isolated yeast mitochondria and Lactococcus lactis as well as by oxygen consumption rate in mammalian cells. Using this approach, closantel and CD437 were identified as broad-spectrum ANT inhibitors, whereas leelamine was found to be a modulator of ANT function. This yeast "knock-out/knock-in" screening strategy is applicable to a broad range of essential molecular targets that are required for yeast survival.
The genetic alteration of p53 is associated with neovascularization during progression of glioma to its more malignant form, glioblastoma. Hence, one or more of the genes transactivated by p53 is ...likely to function as an angiogenesis inhibitors. We isolated a novel p53-inducible gene that encodes a 1584-amino-acid product containing five thrombospondin type 1 (TSP-type 1) repeats and is specifically expressed in the brain. A recombinant protein corresponding to the TSP-type 1 repeats of this gene product inhibited in vivo neovascularization induced by bFGF in the rat cornea. The expression of this gene, designated BAI1 (brain-specific angiogenesis inhibitor 1) was absent or significantly reduced in eight of nine glioblastoma cell lines, suggesting BAI1 plays a significant role in angiogenesis inhibition, as a mediator of p53.
The prevalence of asthma continues to increase in westernized countries, and optimal treatment remains a significant therapeutic challenge. Recently, CD1d-restricted invariant NKT (iNKT) cells were ...found to play a critical role in the induction of airway hyperreactivity (AHR) in animal models and are associated with asthma in humans. To test whether iNKT cell-targeted therapy could be used to treat allergen-induced airway disease, mice were sensitized with OVA and treated with di-palmitoyl-phosphatidyl-ethanolamine polyethylene glycol (DPPE-PEG), a CD1d-binding lipid antagonist. A single dose of DPPE-PEG prevented the development of AHR and pulmonary infiltration of lymphocytes upon OVA challenge, but had no effect on the development of OVA-specific Th2 responses. In addition, DPPE-PEG completely prevented the development of AHR after administration of alpha-galactosylceramide (alpha-GalCer) intranasally. Furthermore, we demonstrate that DPPE-PEG acts as antagonist to alpha-GalCer and competes with alpha-GalCer for binding to CD1d. Finally, we show that DPPE-PEG completely inhibits the alpha-GalCer-induced phosphorylation of ERK tyrosine kinase in iNKT cells, suggesting that DPPE-PEG specifically blocks TCR signaling and thus activation of iNKT cells. Because iNKT cells play a critical role in the development of AHR, the inhibition of iNKT activation by DPPE-PEG suggests a novel approach to treat iNKT cell-mediated diseases such as asthma.
NK4 composed of the N-terminal hairpin and subsequent four-kringle domains of Hepatocyte growth factor (HGF) is bifunctional, acting as a competitive antagonist for HGF and an angiogenesis inhibitor. ...In this study, we determined whether or not four-kringle domains of HGF (K1–4) have anti-angiogenic activity. For this purpose, we prepared recombinant K1–4 and NK4, using the baculovirus expression system. Although NK4 antagonized HGF-induced DNA synthesis of rat hepatocytes, cell scattering of MDCK cells and the c-Met/HGF receptor tyrosine phosphorylation in endothelial cells, K1–4 failed to antagonize HGF-induced DNA synthesis, cell scattering and the c-Met/HGF receptor tyrosine phosphorylation in endothelial cells, thus, indicating that K1–4 lacks HGF-antagonist activity. However, endothelial proliferation and migration induced by HGF was inhibited by K1–4, similar to the case seen with NK4. Furthermore, K1–4 inhibited the proliferation and migration of human dermal microvascular endothelial cells induced by vascular endothelial growth factor or by basic fibroblast growth factor. We propose that kringle 1–4 of HGF inhibits angiogenic responses in endothelial cells, independently of HGF-c-Met signaling pathways.
Hydrodynamic tail vein (HTV) delivery is a simple and rapid tail vein injection method of a high volume of naked plasmid DNA resulting in high levels of foreign gene expression in organs, especially ...the liver. Compared to other organs, HTV delivery results in more than a 1000-fold higher transgene expression in liver. After being bitten by malaria-infected mosquitoes, malaria parasites transiently infect the host liver and form the liver stages. The liver stages are known to be the key target for CD8+ T cells that mediate protective anti-malaria immunity in an animal model. Therefore, in this study, we utilized the HTV delivery technique as a tool to determine the in vivo cytotoxic effect of malaria antigen-specific CD8+ T cells. Two weeks after mice were immunized with recombinant adenoviruses expressing malarial antigens, the immunized mice as well as naïve mice were challenged by HTV delivery of naked plasmid DNA co-encoding respective antigen together with luciferase using dual promoters. Three days after the HTV challenge, non-invasive whole-body bioluminescent imaging was performed. The images demonstrate in vivo activity of CD8+ T cells against malaria antigen-expressing cells in liver.
Although adenovirus (Ad) has been regarded as an excellent vaccine vector, there are 2 major drawbacks to using this platform: (a) Ad-based vaccines induce a relatively weak humoral response against ...encoded transgenes, and (b) preexisting immunity to Ad is highly prevalent among the general population. To overcome these obstacles, we constructed an Ad-based malaria vaccine by inserting a B cell epitope derived from a Plasmodium yoelii circumsporozoite (CS) protein (referred to as the PyCS-B epitope) into the capsid proteins of WT/CS-GFP, a recombinant Ad expressing P. yoelii CS protein and GFP as its transgene. Multiple vaccinations with the capsid-modified Ad induced a substantially increased level of protection against subsequent malaria challenge in mice when compared with that of unmodified WT/CS-GFP. Increased protection correlated with augmented antibody responses against the PyCS-B epitope expressed in the capsid. Furthermore, replacement of hypervariable region 1 (HVR1) of the Ad capsid proteins with the PyCS-B epitope circumvented neutralization of the modified Ad by preexisting Ad-specific antibody, both in vivo and in vitro. Importantly, the immunogenicity of the Ad-containing PyCS-B epitope in the HVR1 and a P. yoelii CS transgene was maintained. Overall, this study demonstrates that the HVR1-modifed Ad vastly improves upon Ad as a promising malaria vaccine platform candidate.
Adenovirus (Ad) is thought to be one of the most promising platforms for a malaria vaccine targeted against its liver stages, because of its ability to induce a strong T-cell response against a ...transgene. However, a further improvement of this platform is needed in order to elicit another arm of the immunity, i.e. humoral response, against malaria.
In order to augment immunogenicity and protective efficacy of Ad-based malaria vaccine, we inserted B-cell, as well as CD4+ T-cell, epitopes of Plasmodium falciparum circumsporozoite protein (PfCSP) into the capsid protein, Hexon, and the core protein, VII (pVII), of Ad, respectively, in addition to the PfCSP transgene. Insertion of PfCSP-derived B cell epitope to Hexon significantly enhanced the epitope-specific antibody response compared to AdPfCSP, an Ad vaccine expressing only PfCSP transgene. PfCSP-derived CD4+ T-cell epitope insertion into pVII augmented not only PfCSP-specific CD4+ T-cell response but also anti-PfCSP antibody response. Finally, mice immunized with AdPfCSP having both Hexon and pVII modifications were more protected than AdPfCSP or Hexon-modified AdPfCSP against challenge with transgenic rodent malaria parasites expressing the PfCSP.
Overall, this study has demonstrated that Hexon and pVII-modified AdPfCSP vaccine is a promising malaria vaccine which induces strong PfCSP-specific humoral, CD4+ T-cell, and CD8+ T-cell responses and protects against infection with transgenic malaria parasites expressing the PfCSP.
The β2-adrenergic receptor gene (ADRB2) is a target molecule of β2-agonists. Single nucleotide polymorphisms (SNPs) in the ADRB2 are related to the effectiveness of β2-agonists. However, there are ...some discrepancies in the results of pharmacogenetic studies of ADRB2 among different ethnic groups. The aims of this study were to determine the ADRB2 haplotypes and diplotypes in Japanese asthmatic and non-asthmatic subjects and to examine their relation to asthma and to compare these results with previous studies done in other ethnic groups.
Complete sequences for 3 kb promoter and 1.2 kb structural regions of ADRB2 were analyzed in 48 Japanese asthmatics and 100 controls, and haplotypes and diplotypes of SNPs were analyzed.
Fifteen SNPs including a novel one in −839 were observed. Allele frequencies for all SNPs were similar between asthmatics and controls. We also identified 42 haplotypes and 54 diplotypes of ADRB2 in a Japanese population. The frequencies were similar between the two groups. They were classified into 17 and 23 types, respectively, according to Drysdale’s haplotype-organization system, and a significant ethnic difference was observed between the Japanese and Caucasian populations.
The frequencies of SNPs and ADBR2 haplotypes in Japanese are different from those in Caucasians and African Americans. These divergences might imply the need for independent pharmacogenetic studies for ADBR2 in each ethnic group.
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