Identification of a Novel Marine Fish Virus, Singapore Grouper Iridovirus-Encoded MicroRNAs Expressed in Grouper Cells by Solexa Sequencing

BACKGROUND: MicroRNAs (miRNAs) are ubiquitous non-coding RNAs that regulate gene expression at the post-transcriptional level. An increasing number of studies has revealed that viruses can also encode miRNAs, which are proposed to be involved in viral replication and persistence, cell-mediated antiviral immune response, angiogenesis, and cell cycle regulation. Singapore grouper iridovirus (SGIV) is a pathogenic iridovirus that has severely affected grouper aquaculture in China and Southeast Asia. Comprehensive knowledge about the related miRNAs during SGIV infection is helpful for understanding the infection and the pathogenic mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: To determine whether SGIV encoded miRNAs during infection, a small RNA library derived from SGIV-infected grouper (GP) cells was constructed and sequenced by Illumina/Solexa deep-sequencing technology. We recovered 6,802,977 usable reads, of which 34,400 represented small RNA sequences encoded by SGIV. Sixteen novel SGIV-encoded miRNAs were identified by a computational pipeline, including a miRNA that shared a similar sequence to herpesvirus miRNA HSV2-miR-H4-5p, which suggests miRNAs are conserved in far related viruses. Generally, these 16 miRNAs are dispersed throughout the SGIV genome, whereas three are located within the ORF057L region. Some SGIV-encoded miRNAs showed marked sequence and length heterogeneity at their 3' and/or 5' end that could modulate their functions. Expression levels and potential biological activities of these viral miRNAs were examined by stem-loop quantitative RT-PCR and luciferase reporter assay, respectively, and 11 of these viral miRNAs were present and functional in SGIV-infected GP cells. CONCLUSIONS: Our study provided a genome-wide view of miRNA production for iridoviruses and identified 16 novel viral miRNAs. To the best of our knowledge, this is the first experimental demonstration of miRNAs encoded by aquatic animal viruses. The results provide a useful resource for further in-depth studies on SGIV infection and iridovirus pathogenesis

Roles of telocytes dominated cell–cell communication in fibroproliferative acute respiratory distress syndrome

Abstract Telocytes (TCs) are a new type of interstitial cell identified in multiple tissues of mammals, including the human lung, and mediate homocellular or heterocellular cell‐cell communication. Acute respiratory distress syndrome (ARDS) is characterized by acute hypoxemia respiratory failure and combined with direct and indirect lung injury, which is induced by pneumonia, sepsis, burns, etc. Pulmonary fibrosis is a progressive lung disease that occurs due to increased fibrosis of lung tissue in response to chronic injury of the epithelium and gets more and more attention as a well‐recognized sequela of ARDS or mechanical ventilation. However, the existing intervention measures could not prevent the progression of pulmonary fibrosis. Although the protective effect of TCs in acute lung injury had been demonstrated in both cellular and animal models in previous studies by our or other researchers, the roles of TCs mediated cell‐cell communication in fibroproliferative ARDS is unclear. This review is aimed at integrating our understanding of TC‐mediated cell–cell communication in lung diseases with pulmonary fibrosis after ARDS

Single‐cell RNA sequencing reveals telocytes subsets of human lung

Abstract Background Telocyte (TC) is a recently defined renewed cell and its dominant intercommunication with other cells displays multiple functions in tissue homeostasis and diseases. Alveolar epithelial cells and immune cells were in the lung cancer heterogeneity, progression, and metastasis, and further associated with antitumor therapeutic strategies. However, few studies focus on the roles of TCs in lung cancer. Methods In this article, we used the public scRNA‐Seq data (including healthy control, chronic obstructive pulmonary disease, non–small cell lung cancer, lymph node metastases from non–small cell lung cancer, and systemic sclerosis–associated interstitial lung disease patients) to analyze the cellular dynamics in human lung and distinct types of TCs and their communication networks with the variety of cell types. Results Six subclusters of TCs were identified by expression of specific biological function markers, which demonstrated the diversity of TCs subsets in lung tissue. Further results showed TCs had communication with epithelial cells or immune cells subsets by the ligand–receptor interaction, including TIMP metallopeptidase inhibitor 1CD63, fibulin 1integrin subunit beta 1, vimentinCD44, macrophage migration inhibitory factorCD74, and amyloid beta precursor proteinCD74. Ligand–receptor interaction heterogeneity was revealed in lung tissue of healthy or diseases. Enhanced specific signals in ligandreceptor interaction were revealed, including integrin beta 1 and CD44 were appraised in the communication of TCs with epithelial cells, NK cells, NKT cells, CD4+ exhausted T cells, CD4+ memory/effector T cells, CD4+ naïve T cells, CD8+ exhausted T cells, CD8+ memory/effector T cells, and CD8+ naïve T cells. CD63, a marker identified in TCs exosomes was emphasized in our current analysis which is closely related to communication of TCs with other cell types. Conclusion These results will provide us with new insight into the mechanisms of TCs‐dominated communication and promise therapy of TC exosomes in lung diseases

miR-200c Accelerates Hepatic Stellate Cell-Induced Liver Fibrosis via Targeting the FOG2/PI3K Pathway

Background. Although expression of miR-200s is aberrant in liver fibrosis, its role in liver fibrogenesis still remains unknown. Here, we investigated the role of miR-200c in the activation of human hepatic stellate cells (HSCs) and induction of liver fibrosis. Methods. We engineered human HSCs (LX2 cell line) to stably express miR-200c (LX2-200c) or empty vector control (LX2-nc). Results. miR-200c expression upregulated α-smooth muscle actin (SMA) and vimentin, enhanced HSCs growth and migration, increased expression of collagen type I (a main component of ECM) gene and secretion of epidermal growth factor (EGF), and upregulated the phosphorylation of Akt, a downstream effector of the PI3K pathway. As a target of miR-200s and inhibitor of PI3K pathway, FOG2 protein expression was significantly suppressed in LX2-200c cells. Moreover, LY294002, a highly selective inhibitor of PI3K, blocked phosphorylation of Akt and the effects of miR-200c. Conclusions. These data suggest that miR-200c activates HSCs in liver fibrosis possibly by downregulating FOG2 protein expression and upregulating PI3K/Akt signaling. Autocrine activation of EGF signaling may also be a mechanism of miR-200c-mediated HSCs activation. So miR-200c can be a potential marker for HSCs activation and liver fibrosis progression, as well as a potential target to attenuate liver fibrosis