Mutations in the adenosine deaminase ADAR1 that prevent endogenous Z-RNA binding induce Aicardi-Goutières-syndrome-like encephalopathy.

Mutations in the adenosine-to-inosine RNA-editing enzyme ADAR1 p150, including point mutations in the Z-RNA recognition domain Zα, are associated with Aicardi-Goutières syndrome (AGS). Here, we examined the in vivo relevance of ADAR1 binding of Z-RNA. Mutation of W197 in Zα, which abolished Z-RNA binding, reduced RNA editing. Adar1W197A/W197A mice displayed severe growth retardation after birth, broad expression of interferon-stimulated genes (ISGs), and abnormal development of multiple organs. Notably, malformation of the brain was accompanied by white matter vacuolation and gliosis, reminiscent of AGS-associated encephalopathy. Concurrent deletion of the double-stranded RNA sensor MDA5 ameliorated these abnormalities. ADAR1 (W197A) expression increased in a feedback manner downstream of type I interferons, resulting in increased RNA editing at a subset of, but not all, ADAR1 target sites. This increased expression did not ameliorate inflammation in Adar1W197A/W197A mice. Thus, editing of select endogenous RNAs by ADAR1 is essential for preventing inappropriate MDA5-mediated inflammation, with relevance to the pathogenesis of AGS.

RNA editing of AZIN1 coding sites is catalyzed by ADAR1 p150 after splicing.

Adenosine-to-inosine RNA editing is catalyzed by nuclear adenosine deaminase acting on RNA 1 (ADAR1) p110 and ADAR2, and cytoplasmic ADAR1 p150 in mammals, all of which recognize dsRNAs as targets. RNA editing occurs in some coding regions, which alters protein functions by exchanging amino acid sequences, and is therefore physiologically significant. In general, such coding sites are edited by ADAR1 p110 and ADAR2 before splicing, given that the corresponding exon forms a dsRNA structure with an adjacent intron. We previously found that RNA editing at two coding sites of antizyme inhibitor 1 (AZIN1) is sustained in Adar1 p110/Aadr2 double KO mice. However, the molecular mechanisms underlying RNA editing of AZIN1 remain unknown. Here, we showed that Azin1 editing levels were increased upon type I interferon treatment, which activated Adar1 p150 transcription, in mouse Raw 264.7 cells. Azin1 RNA editing was observed in mature mRNA but not precursor mRNA. Furthermore, we revealed that the two coding sites were editable only by ADAR1 p150 in both mouse Raw 264.7 and human embryonic kidney 293T cells. This unique editing was achieved by forming a dsRNA structure with a downstream exon after splicing, and the intervening intron suppressed RNA editing. Therefore, deletion of a nuclear export signal from ADAR1 p150, shifting its localization to the nucleus, decreased Azin1 editing levels. Finally, we demonstrated that Azin1 RNA editing was completely absent in Adar1 p150 KO mice. Thus, these findings indicate that RNA editing of AZIN1 coding sites is exceptionally catalyzed by ADAR1 p150 after splicing.

RNA editing at a limited number of sites is sufficient to prevent MDA5 activation in the mouse brain.

Adenosine deaminase acting on RNA 1 (ADAR1), an enzyme responsible for adenosine-to-inosine RNA editing, is composed of two isoforms: nuclear p110 and cytoplasmic p150. Deletion of Adar1 or Adar1 p150 genes in mice results in embryonic lethality with overexpression of interferon-stimulating genes (ISGs), caused by the aberrant recognition of unedited endogenous transcripts by melanoma differentiation-associated protein 5 (MDA5). However, among numerous RNA editing sites, how many RNA sites require editing, especially by ADAR1 p150, to avoid MDA5 activation and whether ADAR1 p110 contributes to this function remains elusive. In particular, ADAR1 p110 is abundant in the mouse brain where a subtle amount of ADAR1 p150 is expressed, whereas ADAR1 mutations cause Aicardi-Goutières syndrome, in which the brain is one of the most affected organs accompanied by the elevated expression of ISGs. Therefore, understanding RNA editing-mediated prevention of MDA5 activation in the brain is especially important. Here, we established Adar1 p110-specific knockout mice, in which the upregulated expression of ISGs was not observed. This result suggests that ADAR1 p150-mediated RNA editing is enough to suppress MDA5 activation. Therefore, we further created Adar1 p110/Adar2 double knockout mice to identify ADAR1 p150-mediated editing sites. This analysis demonstrated that although the elevated expression of ISGs was not observed, only less than 2% of editing sites were preserved in the brains of Adar1 p110/Adar2 double knockout mice. Of note, we found that some sites were highly edited, which was comparable to those found in wild-type mice, indicating the presence of ADAR1 p150-specific sites. These data suggest that RNA editing at a very limited sites, which is mediated by a subtle amount of ADAR1 p150, is sufficient to prevents MDA5 activation, at least in the mouse brain.

An Aicardi-Goutières Syndrome-Causative Point Mutation in Adar1 Gene Invokes Multiorgan Inflammation and Late-Onset Encephalopathy in Mice.

Aicardi-Goutières syndrome (AGS) is a congenital inflammatory disorder accompanied by overactivated type I IFN signaling and encephalopathy with leukodystrophy and intracranial calcification. To date, none of the mouse models carrying an AGS-causative mutation has mimicked such brain pathology. Here, we established a mutant mouse model carrying a K948N point mutation, corresponding to an AGS-causative K999N mutation, located in a deaminase domain of the Adar1 gene that encodes an RNA editing enzyme. Adar1K948N/K948N mice displayed postnatal growth retardation. Hyperplasia of splenic white pulps with germinal centers and hepatic focal inflammation were observed from 2 mo of age. Inflammation developed in the lungs and heart with lymphocyte infiltration in an age-dependent manner. Furthermore, white matter abnormalities with astrocytosis and microgliosis were detected at 1 y of age. The increased expression of IFN-stimulated genes was detected in multiple organs, including the brain, from birth. In addition, single-nucleus RNA sequencing revealed that this elevated expression of IFN-stimulated genes was commonly observed in all neuronal subtypes, including neurons, oligodendrocytes, and astrocytes. We further showed that a K948N point mutation reduced the RNA editing activity of ADAR1 in vivo. The pathological abnormalities found in Adar1K948N/K948N mice were ameliorated by either the concurrent deletion of MDA5, a cytosolic sensor of unedited transcripts, or the sole expression of active ADAR1 p150, an isoform of ADAR1. Collectively, such data suggest that although the degree is mild, Adar1K948N/K948N mice mimic multiple AGS phenotypes, including encephalopathy, which is caused by reduced RNA editing activity of the ADAR1 p150 isoform.

Expansion of Group 2 Innate Lymphoid Cells in Patients with End-Stage Renal Disease and Their Clinical Significance.

Group 2 innate lymphoid cells (ILC2s) play an important role in the control of tissue inflammation and homeostasis. However, the role of ILC2s in patients with end-stage renal disease (ESRD) has never been illustrated. In this study, we investigated ILC2s in ESRD patients and their clinical significance. Results showed that the frequencies and absolute numbers of ILC2s, not group 1 innate lymphoid cells or innate lymphoid cell precursors, were significantly elevated in the peripheral blood of ESRD patients when compared with those from healthy donor controls. Moreover, ILC2s from ESRD patients displayed enhanced type 2 cytokine production and cell proliferation. Plasma from ESRD patients significantly increased ILC2 levels and enhanced their effector function after in vitro treatment. The expression of phosphorylation of STAT5 in ILC2s, as well as the amounts of IL-2 in plasma, were increased in ESRD patients when compared with those from healthy donors. Clinically, ESRD patients with higher ILC2 frequencies displayed lower incidence of infectious complications during a mean of 21 month follow-up study. The proportions of ILC2s were negatively correlated with the prognostic biomarkers of chronic kidney disease, including serum parathyroid hormone, creatinine, and phosphorus, whereas they were positively correlated with serum calcium. These observations indicate that ILC2s may play a protective role in ESRD.

Neutrophil-to-Apolipoprotein A1 Ratio Predicted Overall Survival in Hepatocellular Carcinoma Receiving Transarterial Chemoembolization.

PURPOSE: The purpose of this study was to investigate the predictive capability of neutrophil-to-apolipoprotein A1 ratio (NAR) for predicting overall survival (OS) among patients with hepatocellular carcinoma (HCC) receiving transarterial chemoembolization (TACE). PATIENTS AND METHODS: We investigated the clinical features of 554 patients with HCC receiving TACE and assessed NAR's predictive value for OS with 222 patients (the discovery cohort) and 332 patients (the validation cohort). The association of NAR with circulation lectin-type oxidized low-density lipoprotein receptor-1-positive (LOX-1+ ) polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) was illustrated. RESULTS: Multivariate Cox regression revealed that lymphocyte count; Tumor, Node, Metastasis (TNM) stage; and NAR were independent prognostic factors in the discovery cohort. The validation cohort confirmed the independent prognostic value of TNM stage and NAR. Patients with low NAR (<2.7) displayed significantly increased OS in the discovery cohort (59.8 months vs. 21 months), the validation group (38.0 months vs. 23.6 months), and the total cohort (44.1 months vs. 22.0 months). A Cox proportional hazards model was used to combine Cancer of the Liver Italian Program (CLIP) score with discretized NAR. C-index illustrated that NAR-integrated CLIP score was the best model compared with NAR and CLIP score. Furthermore, NAR-CLIP presented superior predictive capacity for 10-, 20-, 30-, 40-, 50-, and 60-month survival compared with CLIP score by survival receiver-operator characteristic analysis in the discovery cohort, validation cohort, and total cohort. NAR was significantly associated with LOX-1+ PMN-MDSCs by linear regression. CONCLUSION: This study identified NAR as an independent predictor for OS among patients with HCC receiving TACE. NAR reflected circulation LOX-1+ PMN-MDSC level. IMPLICATIONS FOR PRACTICE: The present study identified neutrophil-to-apolipoprotein A1 ratio (NAR) as an independent predictor for overall survival among patients with hepatocellular carcinoma receiving transarterial chemoembolization. NAR reflected circulation level of lectin-type oxidized low-density lipoprotein receptor-1-positive polymorphonuclear myeloid-derived suppressor cells.

Endoplasmic reticulum stress induced LOX-1+ CD15+ polymorphonuclear myeloid-derived suppressor cells in hepatocellular carcinoma.

A recent study indicated that Lectin-type oxidized LDL receptor-1 (LOX-1) was a distinct surface marker for human polymorphisms myeloid-derived suppressor cells (PMN-MDSC). The present study was aimed to investigate the existence LOX-1 PMN-MDSC in hepatocellular carcinoma (HCC) patients. One hundred and twenty-seven HCC patients, 10 patients with mild active chronic hepatitis B, 10 liver cirrhosis due to hepatitis B, 10 liver dysplastic node with hepatitis B and 50 health control were included. LOX-1+  CD15+ PMN-MDSC were significantly elevated in HCC patients compared with healthy control and patients with benign diseases. LOX-1+  CD15+ PMN-MDSC in circulation were positively associated with those in HCC tissues. LOX-1+  CD15+ PMN-MDSCs significantly reduced proliferation and IFN-γ production of T cells with a dosage dependent manner with LOX-1-  CD15+ PMNs reached negative results. The suppression on T cell proliferation and IFN-γ production was reversed by ROS inhibitor and Arginase inhibitor. ROS level and activity of arginase of LOX-1 + CD15+ PMN were higher in LOX-1+  CD15+ PMN-MDSCs than LOX-1-  CD15+ PMNs, as well as the expression of the NADPH oxidase NOX2 and arginase I. RNA sequence revealed that LOX-1+ CD15+ PMN-MDSCs displayed significantly higher expression of spliced X-box -binding protein 1 (sXBP1), an endoplasmic reticulum (ER) stress marker. ER stress inducer induced LOX-1 expression and suppressive function for CD15+ PMN from health donor. For HCC patients, LOX-1+  CD15+ PMN-MDSCs were positively related to overall survival. Above all, LOX-1+  CD15+ PMN-MDSC were elevated in HCC patients and suppressed T cell proliferation through ROS/Arg I pathway induced by ER stress. They presented positive association with the prognosis of HCC patients.

Expansion of polymorphonuclear myeloid-derived suppressor cells in patients with end-stage renal disease may lead to infectious complications.

Myeloid-derived suppressor cells (MDSCs) are recently identified immune suppressive cells in multiple chronic inflammations. Here, we investigated MDSCs in patients with end-stage renal disease (ESRD) and their clinical significance in these patients and healthy individuals (49 each). Polymorphonuclear and mononuclear MDSCs were investigated by flow cytometry. Patients with ESRD before hemodialysis presented a significantly higher level of polymorphonuclear MDSCs. Depletion of polymorphonuclear-MDSCs resolved T cell IFN-γ responses. By co-culture, T cell proliferation and the production of IFN-γ were abrogated by the addition of polymorphonuclear MDSCs in a dose-dependent manner. Both of these effects were reversed by a reactive oxygen species inhibitor. The levels of reactive oxygen species were higher in polymorphonuclear MDSCs derived from patients with ESRD than from normal individuals. The mRNA level of NOX2, the key protein complex responsible for reactive oxygen species production, was higher in ESRD-related polymorphonuclear MDSCs. The phospho-STAT3 level, a key activator of MDSCs, was higher in ESRD-related polymorphonuclear MDSCs. Finally, the polymorphonuclear MDSC level before and after hemodialysis was positively related to infectious diseases. Patients with ESRD were dichotomized into 2 groups by the amount of polymorphonuclear MDSCs. Patients with high levels of polymorphonuclear MDSCs presented with a higher incidence of infectious events. Thus, polymorphonuclear MDSCs were elevated in ESRD patients with strong immune-suppressive capability through a phospho-STAT3/reactive oxygen species pathway. Hence, polymorphonuclear MDSCs might increase the risk of infectious complications.

Alanine aminotransferase to hemoglobin ratio is an indicator for disease progression for hepatocellular carcinoma patients receiving transcatheter arterial chemoembolization.

The prognosis of hepatocellular carcinoma (HCC) patients receiving transcatheter arterial chemoembolization (TACE) is far from being identified. The present study aimed to assess the role of blood cell counts, routine liver function tests, and alanine aminotransferase to hemoglobin ratio (AHR) in predicting the progression-free survival (PFS) of these patients. A total of 243 HCC patients receiving TACE were analyzed retrospectively. Cancer of the Liver Italian Program (CLIP) score system was indentified to be the best score system for this patient subgroup according to the Akaike information criterion (AIC) index and linear trend χ (2). Then, prognostic value of parameters was determined by integration into the CLIP score system. As a result, AHR was confirmed to be an independent predictor for the PFS of HCC patients receiving TACE (p = 0.001) with the other parameters failing to reach statistical significance. Moreover, AHR improved the performance of CLIP by adjusting into it, thus improving its discriminatory ability. AHR defined ≤0.4583 as low level and >0.4583 as high level. And, patients were also dichotomized into two groups accordingly. HCC patients receiving TACE with low AHR presented higher 1 year DCR (41.9 vs 18.1 %) compared with patients with high AHR levels. Furthermore, AHR level was associated with prognostic factors such as lower ALP, total bilirubin, and portal vein thrombosis. In summary, the present study firstly indentified AHR as an independent prognostic factor in HCC patients receiving TACE. The subgroup of HCC patients with lower AHR presented preferable disease control and were the idealistic candidates for TACE.

Platelet-to-lymphocyte ratio acts as a prognostic factor for patients with advanced hepatocellular carcinoma.

The platelet count, as an inflammation marker, is involved in the progress of tumor invasion. However, the prognostic value of platelet counts and the platelet-to-lymphocyte ratio (PLR) has not been investigated in patients with advanced hepatocellular carcinoma (HCC). This study aimed to determine the prognostic value of platelet counts and PLR in HCC patients. A total of 243 ethnic Chinese advanced HCC patients from two major hospitals, not receiving systemic sorafenib, were analyzed retrospectively. The prognostic value of differential blood cell counts and PLR for overall survival (OS) was determined by integrating the Cancer of the Liver Italian Program (CLIP) score system and model for end-stage liver disease by using a stepwise model of multivariate Cox regression. The Kaplan-Meier method and receiver operating characteristic (ROC) curves were utilized accordingly. PLR was confirmed to be an independent predictor for OS (p < 0.01), while the remaining parameters had no predictive value. Then, advanced HCC patients were dichotomized into two groups based on the PLR value (≤111.23 or >111.23), according to ROC analysis. Patients with a high PLR had a lower 3-month survival rate (37.6 vs. 57.6%) compared with patients with a low PLR. PLR was associated with aggressive malignant behavior, characterized by distant metastasis and portal vein thrombosis. Additionally, PLR was not associated with the CLIP score and Child-Pugh grade. PLR was identified as an independent prognostic factor for advanced HCC patients not receiving systemic sorafenib; the predictive ability of PLR partially relies on its association with the aggressive nature of HCC.

Autophagic LC3B overexpression correlates with malignant progression and predicts a poor prognosis in hepatocellular carcinoma.

Autophagy is a process that involves lysosomal degradations of cellular organelles and closely related to tumor occurrence and progression. However, its importance in hepatocellular carcinoma (HCC) was still controversial. Therefore, this study is aimed to address the clinicopathologic effect of microtubule-associated protein 1 light chain 3B (LC3B) and Beclin-1, as autophagic markers, in HCC patients. Tissue microarray-based immunohistochemistry was used to examine the expression of LC3B and another autophagy key regulator (Beclin-1) in 156 operable HCC patients. Kaplan-Meier analysis, chi-square test, and Spearman's correlation analysis were used to analyze correlation of LC3B and Beclin-1 and their influence on clinical characteristics and prognosis. We found that the expression level of LC3B was significantly associated with vascular invasion (P = 0.008), lymph node metastasis (P < 0.001), and Beclin-1 expression level (P < 0.001). However, LC3B was not related to other clinicopathological features, including hepatitis B virus infection, liver cirrhosis, tumor number, tumor size, pathology grade, and tumor-node-metastasis (TNM) stage. Besides, correlation between the expression of Beclin-1 and clinicopathological features were not identified. Survival analysis showed that patients with high LC3B expression had a poorer 5-year overall survival (OS) rate than those with low LC3B expression (high vs. low: 79.5 % vs. 20.5 %, P = 0.026). And high LC3B expression tended to be related with shorter progression-free survival (PFS) (P = 0.074), whereas the expression level of Beclin-1 did not show statistically significant association with OS or PFS. Further multivariate analysis revealed that lymph node metastasis (P = 0.047) and LC3B expression level (P = 0.047) were independent factors to predict the prognosis of OS in all patients. Our study demonstrated that high expression of LC3B, correlated with vascular invasion and lymph node metastasis, might be a novel prognostic biomarker and would be a potential therapy target for HCC, especially in operable patients.

Neutrophil-to-lymphocyte ratio acts as a prognostic factor for patients with advanced hepatocellular carcinoma.

Few studies investigated the prognosis of patients with advanced hepatocellular carcinoma (aHCC). This study was aimed to determine the prognostic value of differential blood cell counts including blood white cells, neutrophil, lymphocyte, neutrophil-lymphocyte ratio (NLR), and platelet in patients with aHCC. A total of 205 ethnic Chinese aHCC patients receiving non-systematic sorafenib were analyzed retrospectively. The prognostic value of differential blood cell counts and NLR for overall survival (OS) was determined by integration into Cancer of the Liver Italian Program (CLIP) score system using backward elimination model of multivariate Cox regression. As a result, NLR was confirmed to be an independent predictor for OS (p = 0.001) with the rest parameters presented negative results. Then, aHCC patients were dichotomized into two groups according to NLR values ≤ 2.43 or >2.43. Patients with low NLR presented lower CLIP score and higher 6-month survival rate (56.1 vs 25.9%) compared with patients with high NLR level. Besides, low NLR level was associated with favorable prognostic factors such as lower α-fetoprotein, alkaline phosphatase, and total bilirubin, as well as decreased incidence of ascites, portal vein thrombosis, and metastasis. Besides, low NLR level was associated less white cells and neutrophil granulocytes, as well as more lymphocyte. In summary, the present study firstly indentified NLR as an independent prognostic factor in aHCC patients receiving no systematic sorafenib.

Prognosis value of mitotic kinase Aurora-A for primary duodenal adenocarcinoma.

Others and we have demonstrated that hypoxia-inducible factor 1α (HIF-1α) and transcriptionally upregulated Aurora-A are required for disease progression in several tumors. We investigated the clinicopathological value of HIF-1α and Aurora-A in primary duodenal adenocarcinoma (PDA). Using immunohistochemistry, we evaluated Aurora-A and HIF-1α expression semiquantitatively in 140 PDA cases. There were 76 cases from one institute that formed the training set; 64 cases from another two institutes were used as the testing set to validate the prognostic value of Aurora-A and HIF-1α expression. Aurora-A expression was high or sufficient in the tumor zone, whereas expression was low in the adjacent normal epithelia. High Aurora-A expression, identified using the training set receiver operator characteristic (ROC) analysis-generated cutoff score, predicted poorer overall survival both in the testing set (18.0 vs. 45.1 %, P = 0.001) and training set (23.1 vs. 53.9 %, P = 0.011). Multivariate Cox regression confirmed that Aurora-A was an independent prognostic factor. Contrary to previous studies, we did not detect any correlation between Aurora-A and HIF-1α. Survival analysis showed that HIF-1α level was not correlated with patient outcome (P = 0.466). Activation of Aurora-A, an independent negative prognostic biomarker, might be used to identify particular PDA patients for more selective therapy.

An optimized antiviral modification strategy for prevention of hepatitis B reactivation in patients undergoing prophylactic lamivudine and chemotherapy: a pilot study.

In patients receiving prophylactic lamivudine (LAM) and chemotherapy, hepatitis B virus (HBV) reactivation cannot be eliminated without knowing the latent causes and optimal management. In our previous study, virus breakthrough and relapse were highly suspected as potential virologic causes for HBV reactivation. Therefore, we reviewed 24 previous studies and 447 patients who underwent chemotherapy and prophylactic LAM, with an incidence of 7.2 % HBV reactivation. Virus breakthrough and relapse were seldom investigated in these studies. In addition, 72 patients that underwent prophylactic LAM and chemotherapy at our centers were also analyzed. Among them, eight patients developed virus breakthrough, with another nine developing virus relapse after discontinuation of LAM. Eight patients received antiviral modification, which included administration of adefovir for patients with virus breakthrough or resumption of LAM for patients with virus relapse and none of them developed HBV reactivation. In contrast, of the nine patients who did not receive antiviral modification, six developed HBV reactivation and two died. In conclusion, this study demonstrated that virus breakthrough and relapse were the critical causative factors of HBV reactivation in patients receiving chemotherapy and prophylactic LAM. An optimized antiviral modification strategy could effectively prevent HBV reactivation in patients with virus breakthrough or relapse.

Soil Aggregates and Fertilizer Treatments Drive Bacterial Interactions via Interspecies Niche Overlap.

Bacterial interactions play significant roles in ecological functions in responding to anthropogenic interference and soil structure changes. However, it remains largely unknown how fertilizer regimes and soil particle sizes drive bacterial interactions. To evaluate bacterial interaction patterns in soil aggregates under long-term fertilizer treatments, we sampled nine bacterial co-occurrence communities and compared the difference between interspecies resource consumption patterns and network structure. Despite the differences between fertilizer treatments, the negative correlation ratios of interaction networks in soil aggregates were macroaggregates > microaggregates > silt + clays. Likewise, NPK-supplement (chemical fertilizer) had also decreased the number of positive correlations of the interaction network than M-supplement (organic fertilizer), regardless of the size of soil aggregates. Linear model analysis revealed that interspecies trophic patterns, including niche overlap and nestedness, drove bacterial competition in the interaction networks. Most importantly, interspecies niche overlap may be the intrinsic factor in the effects of fertilizer treatments and soil aggregates on bacterial interactions. This study enhances our understanding of the potential for changes in species trophic patterns and might guide the promotion of land management. IMPORTANCE Despite that the influence of soil structure and fertilizer treatments on the bacterial community has been widely studied, how they drive interspecies interactions has not been largely explored. Connectance and nestedness were significantly correlated with bacterial interactions, but no differences were found in different soil aggregates and fertilizer treatments. However, interspecies niche overlap could respond to soil aggregates and fertilizer treatments and ultimately drive the bacterial interactions. This study enhances our understanding of the mechanism of microbial interactions and highlights the importance of trophic patterns in the bacterial community. Our findings extend knowledge for nutrient availability on interspecific interactions.