An endogenous retroviral element exerts an antiviral innate immune function via the derived lncRNA lnc-ALVE1-AS1.

Endogenous retroviruses (ERVs) constitute an important component of animal and human genomes and are usually silenced by epigenetic mechanisms in adult cells. Although ERVs were recently reported to be linked to early development, tumorigenesis and autoimmune disease, their impacts on antiviral innate immunity and the underlying mechanisms have not been elucidated. Here, we provide the first direct evidence of an endogenous retroviral element affecting antiviral innate immunity via its derived antisense long non-coding RNA (lncRNA). We found that an antisense lncRNA, which is called lnc-ALVE1-AS1 and is transcribed from the endogenous avian leukosis virus in chromosome 1 (ALVE1), distinctly inhibited the entry and replication of exogenous retroviruses in chicken embryonic fibroblasts (CEFs). This behaviour is at least in part attributed to the induction of an antiviral innate immune pathway by ALVE1 activation, suggesting that an activated endogenous retroviral element may induce antiviral defence responses via its derived antisense lncRNA. We also found that lnc-ALVE1-AS1 mediated these effects by activating the TLR3 signalling in the cytoplasm. Our results provide novel insights into the antiviral innate immune function of ERVs, suggesting that ERVs may play an important role in antiviral defences and provide new strategies for the development of new vaccines.

Acute (gangrenous) esophageal necrosis (black esophagus). A rare form of injury with specific histologic features and diverse clinical associations with a common pathogenesis.

Acute esophageal necrosis (AEN) also known as black esophagus is a rare form of injury to the esophageal mucosa that complicates a variety of clinical conditions. It is characterized by circumferential black discoloration of the mucosa. There is little information relating to the histopathologic features and pathogenesis of this condition. In this study we describe the histopathologic features of six cases of AEN (3 autopsy and 3 biopsy cases) and compared the finding to 26 cases of ulcerated esophagitis. Cases and controls were assessed for type of necrosis, inflammatory cells, vascular thrombi, pigment deposits, granulation tissue and presence of viable mucosa. Cases were evaluated with histochemical stains for iron and microorganisms and immunohistochemical stains to inflammatory cells (myeloperoxidase, CD20, CD3 and CD163), squamous cells (pancytokeratin and p40) and muscle (smooth muscle actin). Most patients were males (60%) with an average age of 58 years. All specimens show the characteristic black discoloration of the mucosa. Microscopic examination revealed a distinct band of basophilic necrosis, Prussian blue-negative pigment deposits and fibrin thrombi in vessels. Myeloperoxidase-positive neutrophils were seen beneath the area of necrosis and CD163-positive macrophages throughout the esophagus. Basophilic necrosis was never seen in control cases. Only one control case showed intravascular thrombi and pigment deposits. We conclude that the combination of basophilic necrosis, intravascular thrombi and pigment deposits are diagnostic of AEN. We theorize that microvascular occlusion is the unifying lesion that explains the diversity of conditions associated with this disorder.

Idiopathic Myointimal Hyperplasia of Mesenteric Veins: An Uncommon Cause of Ischemic Colitis With Distinct Mucosal Features.

Idiopathic myointimal hyperplasia of mesenteric veins causes chronic ischemic mucosal injury with segmental strictures that mimic inflammatory bowel disease and nonocclusive ischemic colitis. It is characterized by myointimal proliferative changes that narrow the lumina of veins combined with ischemic injury and ulcers. Most cases reported to date have been diagnosed following surgical resection. The aim of this study was to determine whether mucosal changes of idiopathic myointimal hyperplasia of mesenteric veins are sufficiently sensitive and specific to allow its recognition in biopsy material. The study group consisted of 10 patients with idiopathic myointimal hyperplasia of mesenteric veins who underwent surgical resection of the affected colon, 7 of whom had available prior endoscopic biopsies. The control group included 10 patients each with radiation, nonocclusive ischemia, Crohn disease, diverticulitis, and mucosal amyloidosis, and 5 cases of small vessel (leukocytoclastic) vasculitis. Study patients were mostly older men with distal colorectal disease. All resection specimens showed mucosal ischemia with numerous thick-walled (arteriolized) capillaries and glassy subendothelial fibrin deposits; numerous hyalinized, eosinophilic thrombi were detected in 90% of colectomy specimens. Biopsies showed arteriolized capillaries (100%), subendothelial fibrin deposits (86%), fibrin thrombi (43%), and perivascular hyalinization (43%). Fibrin thrombi were observed in only one case each of ischemic colitis and small vessel vasculitis, and none of the other abovementioned features were seen in any of the controls. We conclude that arteriolized capillaries, subendothelial fibrin deposits, and perivascular hyalinization are frequent and specific features that can facilitate recognition of idiopathic myointimal hyperplasia of mesenteric veins in biopsy samples.

Diphenhydramine as a Cause of Drug-Induced Liver Injury.

Drug-induced liver injury (DILI) is the most common cause of acute liver failure in the Unites States and accounts for 10% of acute hepatitis cases. We report the only known case of diphenhydramine-induced acute liver injury in the absence of concomitant medications. A 28-year-old man with history of 13/14-chromosomal translocation presented with fevers, vomiting, and jaundice. Aspartate-aminotransferase and alanine-aminotransferase levels peaked above 20,000 IU/L and 5,000 IU/L, respectively. He developed coagulopathy but without altered mental status. Patient reported taking up to 400 mg diphenhydramine nightly, without concomitant acetaminophen, for insomnia. He denied taking other medications, supplements, antibiotics, and herbals. A thorough workup of liver injury ruled out viral hepatitis (including A, B, C, and E), autoimmune, toxic, ischemic, and metabolic etiologies including Wilson's disease. A liver biopsy was consistent with DILI without evidence of iron or copper deposition. Diphenhydramine was determined to be the likely culprit. This is the first reported case of diphenhydramine-induced liver injury without concomitant use of acetaminophen.

Biallelic insertion of a transcriptional terminator via the CRISPR/Cas9 system efficiently silences expression of protein-coding and non-coding RNA genes.

The type II bacterial CRISPR/Cas9 system is a simple, convenient, and powerful tool for targeted gene editing. Here, we describe a CRISPR/Cas9-based approach for inserting a poly(A) transcriptional terminator into both alleles of a targeted gene to silence protein-coding and non-protein-coding genes, which often play key roles in gene regulation but are difficult to silence via insertion or deletion of short DNA fragments. The integration of 225 bp of bovine growth hormone poly(A) signals into either the first intron or the first exon or behind the promoter of target genes caused efficient termination of expression of PPP1R12C, NSUN2 (protein-coding genes), and MALAT1 (non-protein-coding gene). Both NeoR and PuroR were used as markers in the selection of clonal cell lines with biallelic integration of a poly(A) signal. Genotyping analysis indicated that the cell lines displayed the desired biallelic silencing after a brief selection period. These combined results indicate that this CRISPR/Cas9-based approach offers an easy, convenient, and efficient novel technique for gene silencing in cell lines, especially for those in which gene integration is difficult because of a low efficiency of homology-directed repair.

IGF2-derived miR-483 mediated oncofunction by suppressing DLC-1 and associated with colorectal cancer.

Emerging evidence indicates that IGF2 plays an important role in various human malignancies, including colorectal cancer (CRC). Hsa-miR-483 is located within intron 7 of the IGF2 locus. However, the mechanism by which increased IGF2 induces carcinogenesis remains largely elusive. DLC-1 has been identified as a candidate tumor suppressor. In this study, we aimed at investigating whether miR-483 transcription is IGF2-dependent, identifying the functional target of miR-483, and evaluating whether tissue and serum miR-483-3p or miR-483-5p levels are associated with CRC. Our results showed that sequences upstream miR-483 had undetectable promoter activity and levels of IGF2, miR-483-3p, and miR-483-5p were synchronously increased in CRC tissues. Positive correlations between IGF2 and miR-483-3p (r=0.4984, ***p<0.0001), and between IGF2 and miR-483-5p (r=0.6659, ***p<0.0001) expression were found. In addition, patients with CRC had a significantly higher serum miR-483-5p level (*p<0.05) compared to normal controls. DLC-1 expression was decreased in colorectal cancer tissues and diminished through transient transfection with miR-483-3p. Our results suggest that IGF2 may exert its oncofunction, at least partly, through its parasitic miR-483 which suppressed DLC-1 in CRC cells. Thus, miR-483 might serve as a new target for therapy and a potential biomarker for the detection of colorectal cancer.

MicroRNA-132 promotes estradiol synthesis in ovarian granulosa cells via translational repression of Nurr1.

BACKGROUND: Estrogen synthesis is an important function of the mammalian ovary. Estrogen plays important roles in many biological processes, including follicular development, oocyte maturation and endometrial proliferation, and dysfunctions in estrogen synthesis contribute to the development of polycystic ovary syndrome and premature ovarian failure. Classical signaling cascades triggered by follicle-stimulating hormone induce estrogen synthesis via the upregulation of Cyp19a1 in granulosa cells (GCs). This study aimed to determine the effect of microRNA-132 (miR-132) on estradiol synthesis in GCs. METHODS: Primary mouse GCs were collected from ovaries of 21-day-old immature ICR mice through follicle puncture. GCs were cultured and treated with the stable cyclic adenosine monophosphate analog 8-Br-cAMP or transfected with miR-132 mimics, Nurr1-specific small interfering RNA oligonucleotides and Flag-Nurr1 plasmids. Concentrations of estradiol and progesterone in culture medium were determined by an automated chemiluminescence-based assay. Quantitative real time PCR and western blot were performed to identify the effect of miR-132 on Cyp19a1, Cyp11a1 and an orphan nuclear receptor-Nurr1 expression in GCs. Direct suppression of Nurr1 via its 3'-untranslated region by miR-132 were further verified using luciferase reporter assays. RESULTS: The expression level of miR-132 in cultured mouse GCs was significantly elevated during 48 h of treatment with 8-Br-cAMP. The synthesis of estradiol increased after the overexpression of miR-132 in mouse GCs. The real-time PCR results demonstrated that miR-132 induced the expression of Cyp19a1 significantly. Nurr1, an orphan nuclear receptor that suppresses Cyp19a1 expression, was found to be a direct target of miR-132. Nurr1 was suppressed by miR-132, as indicated by a luciferase assay and Western blotting. The knockdown of Nurr1 primarily elevated the synthesis of estradiol and partially attenuated the miR-132-induced estradiol elevation, and the ectopic expression of Flag-Nurr1 abrogated the stimulatory effect of miR-132 on estradiol synthesis in mouse GCs. CONCLUSIONS: Our findings suggest that miR-132 is involved in the cAMP signaling pathway and promotes estradiol synthesis via the translational repression of Nurr1 in ovarian GCs.

An unusual presentation of a rare benign tumor in the head and neck: A review of hibernomas.

Hibernomas are rare benign tumors that may present in the head and neck in an unusual manner similar to more common malignant tumors such as lymphoma. Our case report describes several characteristics of a patient and benign tumor presentation that is atypical for the usual presentation of hibernomas as reviewed in the literature. Although hibernomas are rare, our report and review of the literature highlights a particular patient population and important key findings that should make one consider these benign tumors in the differential diagnosis of a young patient presenting with a neck mass.

Addition of vandetanib to chemotherapy in advanced solid cancers: a meta-analysis.

The addition of vandetanib to chemotherapy has been shown to have a marked effect on patients with advanced cancers who had failed previous chemotherapy. We carried out a meta-analysis to determine the efficacy and safety of vandetanib compared with chemotherapy in patients with advanced cancers. For this meta-analysis, we selected randomized clinical trials that compared vandetanib-based therapy (VBT) with the matched chemotherapy or placebo alone in patients with advanced cancers. The outcomes included overall survival (OS), progression-free survival (PFS), the objective response rate, and toxicities. Hazard ratios (HRs) and odds ratios were reported with 95% confidence intervals (CIs). A total of 14 eligible trials were included for the meta-analysis, with 2995 patients in the VBT group and 2479 patients in the control group. A significant improvement was observed in PFS (HR 0.76, 95% CI 0.68-0.86 in all cancers, HR 0.80, 95% CI 0.70-0.90 in lung cancer, HR 0.54, 95% CI 0.40-0.74 in thyroid cancer) and in objective response rate (odds ratio 2.09, 95% CI 1.42-3.07) in the VBT group. However, no significant difference was found in OS (HR 0.96, 95% CI 0.90-1.03). The subgroups of patients with non-small-cell lung cancer who benefited from vandetanib therapy were identified as those with a history of smoking (HR 0.87, 95% CI 0.80-0.95) and an adenocarcinoma histology (HR 0.85, 95% CI 0.77-0.94). In addition, patients who received VBT had an increased incidence of adverse events such as rash, diarrhea, and neutropenia. The addition of vandetanib to chemotherapy significantly improves PFS in patients with locally advanced or metastatic cancers, especially lung and thyroid cancer.

Antisense RNAs and epigenetic regulation.

Antisense RNA is the first noncoding RNA found to have a regulatory function. With the advances of biological science, it has been recognized that the function of antisense RNAs is not only limited to post-transcriptional regulation, but extends to transcriptional regulation of various important genes leading to epigenetic changes in DNA methylation and histone modifications. Gene regulation by antisense RNA is a general phenomenon observed in eukaryotic cells while genome-wide natural antisense transcripts have been identified in many animals and plants. Antisense RNAs are not only involved in X-chromosome inactivation and imprinted silencing in normal cells, but aberrantly expressed antisense RNAs can also induce epigenetic silencing of tumor suppressor genes in cancer cells and deletion-induced aberrant antisense RNAs lead to epigenetic silencing and diseases. While a general picture of the pathways involved in antisense RNA-mediated gene regulation has emerged, many questions remain. The mechanisms by which genes are regulated by antisense RNAs, antisense transcript itself is produced and aberrant antisense RNAs induce human diseases are all research focuses of the future.

Transcriptional adaptation to Clcn5 knockout in proximal tubules of mouse kidney.

Dent disease has multiple defects attributed to proximal tubule malfunction including low-molecular-weight proteinuria, aminoaciduria, phosphaturia, and glycosuria. To understand the changes in kidney function of the Clc5 chloride/proton exchanger gene knockout mouse model of Dent disease, we examined gene expression profiles from proximal S1 and S2 tubules of mouse kidneys. We found many changes in gene expression not known previously to be altered in this disease. Genes involved in lipid metabolism, organ development, and organismal physiological processes had the greatest number of significantly changed transcripts. In addition, genes of catalytic activity and transporter activity also had a great number of changed transcripts. Overall, 720 genes are expressed differentially in the proximal tubules of the Dent Clcn5 knockout mouse model compared with those of control wild-type mice. The fingerprint of these gene changes may help us to understand the phenotype of Dent disease.