Communication between small cytosolic dsDNA and autophagy inhibits CGAS (cyclic GMP-AMP synthase) activation.

The CGAS (cyclic GMP-AMP synthase)-STING1 (stimulator of interferon response cGAMP interactor 1) pathway is an important innate immune pathway that induces proinflammatory cytokine production following stimulation with dsDNA > 45 bp. We recently identified a class of ~ 20-40 bp small cytosolic dsDNA (scDNA) that blocks CGAS-STING1 activation. In this punctum, we discuss the mechanism underlying the inhibition of CGAS-STING1 activation via scDNA. scDNA binds to CGAS but cannot activate its enzymatic activity. It competes with dsDNA > 45 bp for binding with CGAS to inhibit CGAS-STING1 activation. Moreover, scDNA activates macroautophagy/autophagy and induces the autophagic degradation of STING1 and long dsDNA. Autophagy then increases scDNA levels, driving a feedback loop that accelerates the degradation of STING1 and long cytosolic dsDNA. These findings reveal that mutual communication between scDNA and autophagy inhibits CGAS-STING1 activation following stimulation with dsDNA > 45 bp.

Small cytosolic double-stranded DNA represses cyclic GMP-AMP synthase activation and induces autophagy.

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is a major mediator of inflammation following stimulation with >45 bp double-stranded DNA (dsDNA). Herein, we identify a class of ∼20-40 bp small cytosolic dsDNA (scDNA) molecules that compete with long dsDNA (200-1,500 bp herring testis [HT]-DNA) for binding to cGAS, thus repressing HT-DNA-induced cGAS activation. The scDNA promotes cGAS and Beclin-1 interaction, releasing Rubicon, a negative regulator of phosphatidylinositol 3-kinase class III (PI3KC3), from the Beclin-1-PI3KC3 complex. This leads to PI3KC3 activation and induces autophagy, causing degradation of STING and long cytosolic dsDNA. Moreover, DNA damage decreases, and autophagy inducers increase scDNA levels. scDNA transfection and treatment with autophagy inducers attenuate DNA damage-induced cGAS activation. Thus, scDNA molecules serve as effective brakes for cGAS activation, preventing excessive inflammatory cytokine production following DNA damage. Our findings may have therapeutic implications for cytosolic DNA-associated inflammatory diseases.

A p53/lnc-Ip53 Negative Feedback Loop Regulates Tumor Growth and Chemoresistance.

Acetylation is a critical mechanism to modulate tumor-suppressive activity of p53, but the causative roles of long non-coding RNAs (lncRNAs) in p53 acetylation and their biological significance remain unexplored. Here, lncRNA LOC100294145 is discovered to be transactivated by p53 and is thus designated as lnc-Ip53 for lncRNA induced by p53. Furthermore, lnc-Ip53 impedes p53 acetylation by interacting with histone deacetylase 1 (HDAC1) and E1A binding protein p300 (p300) to prevent HDAC1 degradation and attenuate p300 activity, resulting in abrogation of p53 activity and subsequent cell proliferation and apoptosis resistance. Mouse xenograft models reveal that lnc-Ip53 promotes tumor growth and chemoresistance in vivo, which is attenuated by an HDAC inhibitor. Silencing lnc-Ip53 inhibits the growth of xenografts with wild-type p53, but not those expressing acetylation-resistant p53. Consistently, lnc-Ip53 is upregulated in multiple cancer types, including hepatocellular carcinoma (HCC). High levels of lnc-Ip53 is associated with low levels of acetylated p53 in human HCC and mouse xenografts, and is also correlated with poor survival of HCC patients. These findings identify a novel p53/lnc-Ip53 negative feedback loop in cells and indicate that abnormal upregulation of lnc-Ip53 represents an important mechanism to inhibit p53 acetylation/activity and thereby promote tumor growth and chemoresistance, which may be exploited for anticancer therapy.

Prophylactic and therapeutic effects of honey on radiochemotherapy-induced mucositis: a meta-analysis of randomized controlled trials.

PURPOSE: Oral mucositis is a common side effect of radiochemotherapy and may adversely affect the patients' quality of life (QoL). Honey application may reduce the mucositis grade in patients. Here, we conducted a meta-analysis of randomized controlled trials (RCTs) to evaluate the prophylactic and therapeutic effects of honey on radiochemotherapy-induced oral mucositis. METHODS: Publications on RCTs were extracted from the PubMed, Embase, CINAHL, and Cochrane Library databases. The primary outcomes were mucositis grades and pain scores. Secondary outcomes were the recovery time and QoL. The study was registered with PROSPERO (number CRD42018108486). RESULTS: Nineteen RCTs, involving 1276 patients, were reviewed. Honey considerably mitigated oral mucositis in both prophylactic and therapeutic phases. In the prophylactic phase, intolerable mucositis development was significantly prevented in the honey-treated group (RR = 0.18, 95% confidence interval [CI] = 0.09 to 0.41). Patients treated with honey showed significant decrease in pain scores in the first month of treatment (weighted mean difference [WMD] = - 3.25, 95% CI = - 4.41 to - 2.09) and at the end of the treatment (WMD = - 2.32, 95% CI = - 4.47 to - 0.18). CONCLUSION: Honey, which is relatively cheap and easily available, prevented mucositis and effectively mitigate mucositis in patients after radiochemotherapy. Moreover, it significantly reduced the mucositis grade and engendered a fast and painless healing process. Therefore, honey use during and after radiochemotherapy is recommended for mucositis prevention and treatment.

Hepatoma cell-secreted exosomal microRNA-103 increases vascular permeability and promotes metastasis by targeting junction proteins.

Increased vascular permeability facilitates metastasis. Emerging evidence indicates that secreted microRNAs (miRNAs) may mediate the crosstalk between cancer and stromal cells. To date, whether and how secreted miRNAs affect vascular permeability remains unclear. Based on deep sequencing and quantitative PCR, we found that higher level of serum miR-103 was associated with higher metastasis potential of hepatocellular carcinoma (HCC). The in vitro endothelial permeability and transendothelial invasion assays revealed that the conditioned media or exosomes derived from high miR-103-expressing hepatoma cells increased the permeability of endothelial monolayers, but this effect was attenuated if exosome secretion of hepatoma cells was blocked by silencing ALIX and HRS or if miR-103 within hepatoma or endothelial cells was antagonized. Most importantly, pretreating endothelial monolayers with exosomes that were from stable miR-103-expressing hepatoma cells facilitated the transendothelial invasion of tumor cells, and this role of exosomes was abrogated by inhibiting miR-103 in endothelial cells. Further in vivo analyses disclosed that mice with xenografts of stable miR-103-expressing hepatoma cells exhibited higher vascular permeability in tumor, higher level of exosomal miR-103 and greater number of tumor cells in blood circulation, and increased rates of hepatic and pulmonary metastases, compared to control mice. Mechanism investigations revealed that hepatoma cell-secreted miR-103 could be delivered into endothelial cells via exosomes, and then attenuated the endothelial junction integrity by directly inhibiting the expression of VE-Cadherin (VE-Cad), p120-catenin (p120) and zonula occludens 1. Moreover, miR-103 could also promote tumor cell migration by repressing p120 expression in hepatoma cells. CONCLUSION: Hepatoma cell-secreted exosomal miR-103 increases vascular permeability and promotes tumor metastasis by targeting multiple endothelial junction proteins, which highlights secreted miR-103 as a potential therapeutic target and a predictive marker for HCC metastasis. (Hepatology 2018).

[Gaseous phenol removal in a bio-trickling filter].

The performance of a bio-trickling filter (BTF) for treatment of phenol, a model pollutant, was presented. Influences of factors on phenol removal efficiency were studied. The BTF exhibited a high removal efficiency for phenol. The experimental results showed that the phenol efficiency reached 99.5% and kept 98% in the long-term run. The optimal residence time, pH value and spray density were 20.6 s, 7.0 and 1.67 m(3) x (m(2) x h)(-1), respectively. The microbial community structures in the bio-trickling filter for phenol removal were assessed by PCR-DGGE. Based on the 16S rDNA sequence data,results showed that the predominant bacteria for degradation of phenol were Polaromonas sp., Acinetobacter sp., Acidovorax sp., Veillonella parvula and Corynebacterium sp., GC-MS was used to detect component of BTF's outlet gases and pyruvic acid (CH3COCOOH) was found as one kind of intermediates of phenol degradation. Then one possible biodegradation pathway of phenol was inferred.

[Mechanism and performance of styrene oxidation by O3/H2O2].

It can produce a large number of free radicals in O3/H2O2, system, ozone and free radical coupling oxidation can improve the styrene removal efficiency. Styrene oxidation by O3/H2O2 was investigated. Ozone dosage, residence time, H2o2 volume fraction, spray density and molar ratio of O3/C8H8 on styrene removal were evaluated. The experimental results showed that styrene removal efficiency achieved 85.7%. The optimal residence time, H2O2, volume fraction, spray density and O3/C8H8 molar ratio were 20. 6 s, 10% , 1.72 m3.(m2.h)-1 and 0.46, respectively. The gas-phase degradation intermediate products were benzaldehyde(C6H5CHO) and benzoic acid (C6H5 COOH) , which were identified by means of gas chromatography-mass spectrometry(GC-MS). The degradation mechanism of styrene is presented.

[Impact of transfusion of apoptotic and necrotic thymocytes on the survival of mice with sepsis].

OBJECTIVE: To investigate the effect of transfusion of apoptotic and necrotic thymocytes prior to sepsis on the survival rate of mice. METHODS: BALB/c mice are divided into 3 groups and received intravenous injection of PBS (control), apoptotic thymocytes, or necrotic thymocytes. Three days later, cecal ligation and puncture (CLP) were performed to induce sepsis in these mice, and their survival and organ damage were observed. RESULTS: The survival rates of mice in PBS group was 44.6% at the end of first week after CLP, and obvious lung and kidney damages were observed. A significant increase in the survival rate was found in apoptotic cell transfusion group (69.6%, P=0.012), with also lessened lung and kidney damages. The survival rate of mice in necrotic cell transfusion group was only 31.6% at 2 weeks, significantly lower than that in PBS group (P=0.035), and the lung and kidney damage was even more obvious. CONCLUSION: Transfusion of apoptotic thymocytes 3 days before induction of sepsis can reduce organ damage and improve the survival rate of mice, while necrotic cell transfusion produces the opposite effect.

[Differences in the response to sepsis between C57BL/6 and BALB/c mice].

OBJECTIVE: To compare the responses to sepsis between C57BL/6 and BALB/c mice. METHODS: Thirty C57BL/6 mice and 30 BALB/c mice were randomized into sham-operated group and sepsis group (n=15). Sepsis model was established by cecal ligation puncture (CLP) in the mice, and 6 h after the operation, 5 mice from each group were selected randomly for cytokine detection including IL-1beta, IL-2, IL-4, IL-5, IL-10, GM-CSF, IFN-gamma and TNF-alpha by Bio-plex. The other 10 mice in each group were used for survival analysis. RESULTS: The survival rates of BALB/c and C57BL/6 mice were both 100% in one week after the sham operation, but lowered to 10% and 50% in one week after CLP, respectively. The survival rate of C57BL/6 mice was significantly lower than that of BALB/c mice (P<0.05). After CLP, C57BL/6 mice showed significantly greater IL-4, TNF-alpha and IL-10 production than the sham-operated mice, but the concentrations of the 8 cytokines in BALB/c mice after CLP showed no significant increment. CONCLUSION: Compared with BALB/c mice, C57BL/6 strain mouse is more sensitive to sepsis.

[Effect of FK506 on cytokine secretion in whole blood].

OBJECTIVE: To investigate the effect of FK506 on cytokine secretions in whole blood from healthy individuals. METHODS: Blood samples collected from healthy volunteers were co-cultured with different concentrations of FK506 and stimulated with PMA and IONO. The concentrations of 8 cytokines including IL-2, IL-6, IL-12, IL-17, IFN-gamma, TNF-alpha, GM-CSF and G-CSF were detected by Bio-Plex suspension system. RESULTS: Compared with the control group, high-concentration FK506 (20 ng/ml) significantly inhibited the secretions of IL-2, IL-6, IL-12, IL-17, IFN-gamma, TNF-alpha, GM-CSF and G-CSF. At a moderate concentration (5 ng/ml), FK506 inhibited the secretion of GM-CSF significantly. CONCLUSION: FK506 effectively inhibits the secretion of proinflammatory cytokines including IL-6, IFN-gamma and TNF-alpha and also the secretion of IL-2, IL-12, IL-17, GM-CSF and G-CSF. FK506 might play the role of immunosuppression by inhibiting the production of these cytokines by the immune cells. Monitoring the levels of these cytokines might be a potential method for evaluating the adequacy of FK506 doses administered.

Effects of phytase, cellulase, and dehulling treatments on iron and zinc in vitro solubility in faba bean (Vicia faba L.) Flour and Legume Fractions.

Simulations of gastrointestinal digestion were used to try to identify the nature of the complexes between antinutritional factors and iron and zinc in faba bean and legume fractions. In digestible residue of raw faba bean flour, simultaneous action of cellulase and phytases made it possible to release about 28% units more iron than that released with the treatment without enzymes. About 49.8% of iron in raw faba bean flour was solubilized after in vitro digestion and simultaneous action of cellulase and phytase. In the hull fraction, the action of phytases and the simultaneous action of cellulase and phytase allowed about 7 and 35% units of additional zinc to be solubilized, respectively. Single enzymatic degradation of phytates from dehulled faba bean allowed solubilization from 65 to 93% of zinc, depending upon the treatment. In dehulled faba bean, iron was chelated by phytates and by fibers, whereas zinc was almost exclusively chelated by phytates. In the hull of faba bean, a high proportion of iron was chelated by iron-tannins, while the rest of iron as well as the majority of zinc were chelated in complexes between phytates and fibers.

[Effects of apoptotic lymphocytes on proinflammatory cytokine secretion by hepatic sinusoidal endothelial cells].

OBJECTIVE: To investigate the effects of apoptotic lymphocytes on the secretion of cytokines by hepatic sinusoidal endothelial cells (HSEC). METHODS: Human HSEC cells were co-cultured for 16 h with allogenetic apoptotic lymphocytes induced by UVB irradiation. The supernatants were collected and the levels of interleukin-2, interferon-gamma, and tumor necrosis factor-alpha were detected by Luminex technique. RESULTS: All the cytokines were down-regulated by about 50% in HSECs after co-culture with the apoptotic lymphocytes as compared with those in the control group (P<0.05). CONCLUSIONS: Co-culture with apoptotic lymphocytes can down-regulate the secretion of pro-inflammatory cytokines in HSECs, which may contribute to tolerogenic microenvironment in the liver.

[Necrotic cells induce and promote inflammatory responses in vitro].

OBJECTIVE: To investigate the effect of necrotic cells on the secretion of inflammatory cytokines. METHODS: RAW264.7 macrophages and necrotic mouse thymocytes induced by heating were incubated for 18 h at a ratio of 5:1 in the absence or presence of lipopolysaccharide (LPS, 100 ng/ml). The supernatant of the cell culture was collected and the expression and secretion of the pro-inflammatory cytokines were measured using Bio-Plex suspension system. RESULTS: The secretions of tumor necrosis factor-alpha (TNF-alpha) and interlukine-6 (IL-6) by macrophages co-cultured with the necrotic cells were significantly enhanced as compared with the control cells. The necrotic cells also significantly augmented the secretion of the pro-inflammatory cytokines induced by LPS. CONCLUSION: Necrotic cells not only induces pro-inflammatory cytokine expression by themselves but also work synergistically with LPS to enhance the cytokine production, suggesting the important roles of necrotic cells to initiate and maintain the inflammatory responses.

[Determination of p-tert-butylcatechol in styrene monomer by gas chromatography/mass spectrometry].

An efficient method for the determination of p-tert-butylcatechol (TBC) in styrene monomer by gas chromatography/mass spectrometry (GC/MS) has been established. The sample was injected directly, and separated by gas chromatography with capillary column (HP-1, 30 m x 0.32 mm i.d. x 0.25 micron), then determined by a mass-spectrometer with electron impact (EI) at selected ion monitoring (SIM) mode. There was a good linear relationship within the range of 5 mg/kg-50 mg/kg (r2 = 0.9987). Compared with the colorimetric determination by a spectrophotometer (ASTM D4590), the method was proved to be fast and accurate.