Abstract Macrophage‐stimulator of interferon genes (STING) signaling mediated sterile inflammation has been implicated in various age‐related diseases. However, whether and how macrophage mitochondrial DNA (mtDNA) regulates STING signaling in aged macrophages remains largely unknown. We found that hypoxia‐reoxygenation (HR) induced STING activation in macrophages by triggering the release of macrophage mtDNA into the cytosol. Aging promoted the cytosolic leakage of macrophage mtDNA and enhanced STING activation, which was abrogated upon mtDNA depletion or cyclic GMP‐AMP Synthase (cGAS) inhibition. Aged macrophages exhibited increased mitochondrial injury with impaired mitophagy. Mechanistically, a decline in the PTEN‐induced kinase 1 (PINK1)/Parkin‐mediated polyubiquitination of mitochondria was observed in aged macrophages. Pink1 overexpression reversed the inhibition of mitochondrial ubiquitination but failed to promote mitolysosome formation in the aged macrophages. Meanwhile, aging impaired lysosomal biogenesis and function in macrophages by modulating the mTOR/transcription factor EB (TFEB) signaling pathway, which could be reversed by Torin‐1 treatment. Consequently, Pink1 overexpression in combination with Torin‐1 treatment restored mitophagic flux and inhibited mtDNA/cGAS/STING activation in aged macrophages. Moreover, besides HR‐induced metabolic stress, other types of oxidative and hepatotoxic stresses inhibited mitophagy and promoted the cytosolic release of mtDNA to activate STING signaling in aged macrophages. STING deficiency protected aged mice against diverse types of sterile inflammatory liver injuries. Our findings suggest that aging impairs mitophagic flux to facilitate the leakage of macrophage mtDNA into the cytosol and promotes STING activation, and thereby provides a novel potential therapeutic target for sterile inflammatory liver injury in aged patients.
Coxiella burnetii , a global-distributed biological warfare agent, is the causative agent of Q fever. Correct diagnosis of Q fever is challenging and developing a fast, simple, and reliable detection method is necessary. In this study, recombinase polymerase amplification (RPA) assay combined with lateral flow (LF) test was developed targeting 23S rRNA gene of C. burnetii Xinqiao strain. Primers and probe were designed and synthesized, with one set with high amplification efficiency screened for establishment of the method. Reaction conditions were optimized. Sensitivity, specificity, and accuracy were evaluated. The established RPA-LF reaction could be completed in 30 minutes by combining RPA at 37°C with LF at room temperature, with visually judged results. The method showed good specificity without recognizing other bacteria evaluated. It detected positive plasmid and genomic DNA at levels of 10 copies/reaction and 7 copies/reaction, respectively, levels comparable to that of real-time quantitative PCR (RT-qPCR) targeting 23S rRNA gene established previously. Both RPA-LF and RT-qPCR were used to detect C. burnetii -infected mouse samples and the results were fully consistent. The method showed superior detection performance and will provide technical support against C. burnetii in resources-limited areas.
Objective
To study the effect of deferoxamine mesylate on occupied volume and 90 days prognosis in patients after intracerebral hemorrhage (ICH).
Methods
Forty-two ICH patients, admitted to our hospital from February 2013 to May 2014, were chosen in our study and divided into deferoxamine mesylate treatment group and control group (n=21); the occupied volumes and its changed trends of ICH in the two groups were compared; modified Rankin scale(mRS) was used to evaluate the 90 days prognosis.
Results
The difference of the relative occupying volume between the deferoxamine mesylate treatment group and control group on the 4th day was statistically significant (1.44±0.33 vs. 1.91±0.53, t=-3.459, P=0.001). The difference of the variation of the 1st to 4th day relative occupied volume and the 8th to 15th (or discharge) day relative occupied volume was statistically significant: the growth amount of the 1st to 4th day relative occupied volume of the control group was significantly higher than that of deferoxamine mesylate treatment group (P<0.05): the absorbed amount of 8th to 15th (or discharge) day relative occupied volume of the control group was statistically higher than that of deferoxamine mesylate treatment group (P<0.05). There was no significant difference in mRS scores between two groups on the 90th day (±7 days) (χ2=0.000, P=1.000).
Conclusion
Deferoxamine mesylate may reduce the growth amount of 1st to 4th day relative occupied volume and absorbed amount of 8th to 15th (or discharge) day relative occupied volume after ICH, but not influence the 90 days prognosis.
Key words:
Intracerebral hemorrhage; Deferoxamine; Occupied volume; Prognosis
Background and aims Macrophage innate immune response plays an important role in tumorigenesis. However, the role and mechanism of macrophage STING signaling in modulating tumor microenvironment to suppress tumor growth at secondary sites remains largely unclear. Methods STING expression was assessed in liver samples from patients with colorectal cancer (CRC) liver metastasis. Global or myeloid stimulator of interferon gene (STING)-deficient mice, myeloid NOD-like receptor protein 3 (NLRP3)-deficient mice, and wild-type (WT) mice were subjected to a mouse model of CRC liver metastasis by intrasplenic injection of murine colon carcinoma cells (MC38). Liver non-parenchymal cells including macrophages and natural killer (NK) cells were isolated for flow cytometry analysis. Bone marrow-derived macrophages pretreated with MC38 were co-cultured with splenic NK cells for in vitro studies. Results Significant activation of STING signaling were detected in adjacent and tumor tissues and intrahepatic macrophages. Global or myeloid STING-deficient mice had exacerbated CRC liver metastasis and shorten survival, with decreased intrahepatic infiltration and impaired antitumor function of NK cells. Depletion of NK cells in WT animals increased their metastatic burden, while no significant effects were observed in myeloid STING-deficient mice. STING activation contributed to the secretion of interleukin (IL)-18 and IL-1β by macrophages, which optimized antitumor activity of NK cells by promoting the expression of 4-1BBL in macrophages and 4-1BB in NK cells, respectively. Moreover, MC38 treatment activated macrophage NLRP3 signaling, which was inhibited by STING depletion. Myeloid NLRP3 deficiency increased tumor burden and suppressed activation of NK cells. NLRP3 activation by its agonist effectively suppressed CRC liver metastasis in myeloid SITNG-deficient mice. Conclusions We demonstrated that STING signaling promoted NLRP3-mediated IL-18 and IL-1β production of macrophages to optimize the antitumor function of NK cells via the co-stimulation signaling of 4-1BBL/4-1BB.
Acute liver injury can result from a number of different diseases. Inflammatory cytokines are known to be involved in the development of this condition; however, their precise roles and effects on liver function remain unclear. The goal of this study was to determine the relationship between serum cytokine levels and both the severity of liver damage and recovery in acute liver injury. We enrolled 100 patients with acute liver injury caused by drug application who were hospitalized from September 2012 to September 2017 and measured serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and the cytokines, interleukin (IL)-2 and IL-6, before and after clinical therapy. Our results indicate that IL-2 and IL-6 levels are altered significantly following clinical therapy. However, with the exception of an association between IL-2 and ALT, we found no correlation between the differences in cytokine levels pre- and post-therapy and recovery of liver function. In contrast, we observed that pre- vs post-treatment difference in the IL-2/IL-6 ratio negatively correlates with the pre- vs post-treatment difference in ALT and AST values, and positively correlates with ALT and AST at 1-month post-discharge. Thus, our data suggest that IL-2/IL-6 ratio may represent a novel predictor for the prognosis of liver injury.
Although estrogen and testosterone deficiency have often been associated with the development of cardiac diseases in postmenopausal women, the benefits of estrogen or testosterone therapy are controversial. Supplementation with high dose of estrogen or testosterone alone has been associated with many side effects, especially estrogen. This study was aimed to investigate whether supplementation of testosterone in combination with low-dose estrogen conferred stronger cardioprotective effects on ovariectomized rats subjected to ischemia/reperfusion injury. Female Sprague Dawley rats were subjected to sham operation (Sham) or bilateral ovariectomy (OVX). Two weeks after ovariectomy, OVX rats were treated with one of the following: (1) vehicle (OVX), (2) testosterone (100 μg·kg·d) (OVX+T), (3) estrogen (20 μg·kg·d) (OVX+E), (4) testosterone (100 μg·kg·d) + estrogen (20 μg·kg·d) (OVX+T+E) for 4 weeks. The hearts were mounted on the Langendorff apparatus and subjected to ischemia/reperfusion injury subsequent to the determination of hemodynamic parameters. We examined the release of lactate dehydrogenase, serum estrogen, and testosterone levels and the expression of pAkt/Akt and bax/bcl-2. Testosterone supplementation alone improved the heart function, increased p-Akt/Akt and bcl-2 expression, and decreased the release of lactate dehydrogenase. Accordingly, these effects of testosterone were more pronounced when low-dose estrogen was administered simultaneously, whereas estrogen alone at the dose of the experiment had no significant effects. These effects might be partially orchestrated by the Akt signaling pathway.
Old livers are more damaged by hepatic ischemia and reperfusion (IR) injury than young livers. The aim of this study was to investigate the effects of ischemic and rapamycin preconditioning on IR injury in old livers. Young (8-week-old) and aged (60-week-old) mice were subjected to IR or a sham control procedure. The aged mice were randomly divided into six groups: IR (CON), IR with ischemic preconditioning (IPC), IR with rapamycin preconditioning (RAPA), IR with combined ischemic and rapamycin preconditioning (IPC + RAPA), IR with 3-methyladenine (3-MA), IR with combined ischemic and rapamycin preconditioning with 3-MA pretreatment (IPC + RAPA+3-MA). Liver injury was evaluated 6 h after reperfusion. Hepatocellular autophagy induction was also analyzed by western blotting. The results revealed that aged mice had aggravated liver IR injury as compared to young mice. In aged mice following IR, IPC + RAPA but not IPC or RAPA alleviated liver injury, as evidenced by lower levels of serum ALT, improved preservation of liver architecture with lower Suzuki scores, and decreased caspase-3 activity compared with CON. In addition, western blot analysis revealed increased LC3B II but decreased p62 protein expression levels in the IPC + RAPA group, indicating that autophagic flux was restored by combined ischemic and rapamycin preconditioning. Furthermore, autophagy inhibition by the inhibitor 3-MA abrogated the protective role in the IPC + RAPA group, while no significant effects were observed in the CON group. In conclusions, our results demonstrated that combined ischemic and rapamycin preconditioning protected old livers against IR injury, which was likely attributed to restored autophagy activation.
Background/Aims: SKP2 overexpression has been associated with poor prognosis in numerous cancers. The mechanisms of autophagy in the tumor pathogenesis have been a research focus recently. How the SKP2 involved in autophagy expresses oncogenic characteristics, especially in HCC, are largely unclear. Methods: The expression of SKP2 was detected by qPCR, Western blot, Immunohistochemical (IHC) and Immunofluorescence (IF) techniques. SKP2 was knocked down or overexpressed by lentivirus transfection in HCC cells. Functional assays such as CCK8 assays, transwell migration and invasion assays, and colony formation assays were performed to determine the role of SKP2 in HCC. Furthermore, autophagy was induced by glucose deprivation in HCC cells followed by monitoring of the levels and distributions of SKP2, CARM1 and AMPK. Results: Our data showed that SKP2 levels were significantly increased in HCC cell lines and HCC tissues rather than corresponding normal liver tissues, and augmented SKP2 levels were statistically correlated with tumor grade, size and metastases. By up-regulation or down-regulation of SKP2 in HCC cells, we confirmed that SKP2 encourages proliferation, migration, invasion, and colony formation. We then found that SKP2 was inhibited, CARM1 increased and AMPKα2 became activated in the nucleus under glucose deprivation induced autophagy. Moreover, we discovered that SKP2 was repressing CARM1 in the nucleus under nutrient-sufficient conditions in HCC. Conclusions: We show that SKP2 promotes HCC progression and its nuclear functions of autophagy induction with CARM1 and AMPK, which may provide a potential target for HCC therapy.
This study aimed to investigate the mechanism of galectin (Gal)-1 of regulating Treg/Th17 in pathogenesis of acute rejection after liver transplantation in rat.Mononuclear cells were induced to immature dendritic cells (imDCs), which were transfected with or without NF-κB/RelB. Western Blot was performed to detect the expression of NF-κB/RelB. the expression of CD11c, CD45RB, CD80 and MHC II were detected by flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was employed to detect cytokines IL-27 and TGF-β. Lewis and dark agouti (DA) rats were generally anaesthetized by isoflurane inhalation to establish liver transplant models.We demonstrate that Gal-1 disturbs maturation of imDCs by downregulating NF-κB/RelB expression, and Gal-1 negatively controls CD4+ proliferation though IL-27 pathway.In aggregate, Gal-1 promotes Treg differentiation in CD4+ T cells though NF-κB/RelB-IL-27 pathway. These findings suggest a new therapeutic target to mediate Treg population.
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