Inhibition of Proteasome Activity Induces Aggregation of IFIT2 in the Centrosome and Enhances IFIT2-Induced Cell Apoptosis

An engineered DNA aptamer-based PROTAC for precise therapy of p53-R175H hotspot mutant-driven cancer

Targeting oncogenic mutant p53 represents an attractive strategy for cancer treatment due to the high frequency of gain-of-function mutations and ectopic expression in various cancer types. Despite extensive efforts, the absence of a druggable active site for small molecules has rendered these mutants therapeutically non-actionable. Here we develop a selective and effective proteolysis-targeting chimera (PROTAC) for p53-R175H, a common hotspot mutant with dominant-negative and oncogenic activity. Using a novel iterative molecular docking-guided post-SELEX (systematic evolution of ligands by exponential enrichment) approach, we rationally engineer a high-performance DNA aptamer with improved affinity and specificity for p53-R175H. Leveraging this resulting aptamer as a binder for PROTACs, we successfully developed a selective p53-R175H degrader, named dp53m. dp53m induces the ubiquitin-proteasome-dependent degradation of p53-R175H while sparing wildtype p53. Importantly, dp53m demonstrates significant antitumor efficacy in p53-R175H-driven cancer cells both in vitro and in vivo, without toxicity. Moreover, dp53m significantly and synergistically improves the sensitivity of these cells to cisplatin, a commonly used chemotherapy drug. These findings provide evidence of the potential therapeutic value of dp53m in p53-R175H-driven cancers.

Paraptosis: a non-classical paradigm of cell death for cancer therapy

Due to the sustained proliferative potential of cancer cells, inducing cell death is a potential strategy for cancer therapy. Paraptosis is a mode of cell death characterized by endoplasmic reticulum (ER) and/or mitochondrial swelling and cytoplasmic vacuolization, which is less investigated. Considerable evidence shows that paraptosis can be triggered by various chemical compounds, particularly in cancer cells, thus highlighting the potential application of this non-classical mode of cell death in cancer therapy. Despite these findings, there remain significant gaps in our understanding of the role of paraptosis in cancer. In this review, we summarize the current knowledge on chemical compound-induced paraptosis. The ER and mitochondria are the two major responding organelles in chemical compound-induced paraptosis, which can be triggered by the reduction of protein degradation, disruption of sulfhydryl homeostasis, overload of mitochondrial Ca2+, and increased generation of reactive oxygen species. We also discuss the stumbling blocks to the development of this field and the direction for further research. The rational use of paraptosis might help us develop a new paradigm for cancer therapy.

The Impact of Innate Components on Viral Pathogenesis in the Neurotropic Coronavirus Encephalomyelitis Mouse Model

Recognition of viruses invading the central nervous system (CNS) by pattern recognition receptors (PRRs) is crucial to elicit early innate responses that stem dissemination. These innate responses comprise both type I interferon (IFN-I)-mediated defenses as well as signals recruiting leukocytes to control the infection. Focusing on insights from the neurotropic mouse CoV model, this review discusses how early IFN-I, fibroblast, and myeloid signals can influence protective anti-viral adaptive responses. Emphasis is placed on three main areas: the importance of coordinating the distinct capacities of resident CNS cells to induce and respond to IFN-I, the effects of select IFN-stimulated genes (ISGs) on host immune responses versus viral control, and the contribution of fibroblast activation and myeloid cells in aiding the access of T cells to the parenchyma. By unraveling how the dysregulation of early innate components influences adaptive immunity and viral control, this review illustrates the combined effort of resident CNS cells to achieve viral control.

Ifit2 restricts murine coronavirus spread to the spinal cord white matter and its associated myelin pathology

Interferon-induced protein with tetratricopeptide repeats 2, Ifit2, is critical in restricting neurotropic murine-β-coronavirus, RSA59 infection. RSA59 intracranial injection of Ifit2-deficient (-/-) compared to wild-type (WT) mice results in impaired acute microglial activation, reduced CX3CR1 expression, limited migration of peripheral lymphocytes into the brain, and impaired virus control followed by severe morbidity and mortality. While the protective role of Ifit2 is established for acute viral encephalitis, less is known about its influence during the chronic demyelinating phase of RSA59 infection. To understand this, RSA59 infected Ifit2-/- and Ifit2+/+ (WT) were observed for neuropathological outcomes at day 5 (acute phase) and 30 post-infection (chronic phase). Our study demonstrates that Ifit2 deficiency causes extensive RSA59 spread throughout the spinal cord gray and white matter, associated with impaired CD4+ T and CD8+ T cell infiltration. Further, the cervical lymph nodes of RSA59 infected Ifit2-/- mice showed reduced activation of CD4+ T cells and impaired IFNγ expression during acute encephalomyelitis. Interestingly, BBB integrity was better preserved in Ifit2-/- mice, as evidenced by tight junction protein Claudin-5 and adapter protein ZO-1 expression surrounding the meninges and blood vessels and decreased Texas red dye uptake, which may be responsible for reduced leukocyte infiltration. In contrast to sparse myelin loss in WT mice, the chronic disease phase in Ifit2-/- mice was associated with severe demyelination and persistent viral load, even at low inoculation doses. Overall, our study highlights that Ifit2 provides antiviral functions by promoting acute neuroinflammation and thereby aiding virus control and limiting severe chronic demyelination. IMPORTANCE Interferons execute their function by inducing specific genes collectively termed as interferon-stimulated genes (ISGs), among which interferon-induced protein with tetratricopeptide repeats 2, Ifit2, is known for restricting neurotropic viral replication and spread. However, little is known about its role in viral spread to the spinal cord and its associated myelin pathology. Toward this, our study using a neurotropic murine β-coronavirus and Ifit2-deficient mice demonstrates that Ifit2 deficiency causes extensive viral spread throughout the gray and white matter of the spinal cord accompanied by impaired microglial activation and T cell infiltration. Furthermore, infected Ifit2-deficient mice showed impaired activation of T cells in the cervical lymph node and relatively intact blood-brain barrier integrity. Overall, Ifit2 plays a crucial role in mounting host immunity against neurotropic murine coronavirus in the acute phase while preventing mice from developing viral-induced severe chronic neuroinflammatory demyelination, the characteristic feature of human neurological disease multiple sclerosis (MS).

New gold (III) cyanide complex TGS 121 induces ER stress, proteasome inhibition and death of Ras-hyperactivated cells

Metal-based agents in cancer therapy, like cisplatin and its derivates, have established clinical applications but also can induce serious side effects. Thus, metallotherapeutic alternatives for platinum derivatives are developed and intensively studied. Platinum is replaced by several transition metals including gold. Especially gold (III) complexes can have the same square-planar structure and are isoelectric with platinum (II). Hence, they are developed as potential anti-cancer drugs. Thus, our group projected and developed a group of novel cyanide-based gold (III) complexes. Within this work, we aimed to characterize the safety and effectivity of one of them, TGS 121. TGS 121 in our preliminary work was selective for Ras-hyperactivated cells. Here we studied the effects of the novel complex in cancerous Ras-3 T3 and non-cancerous NIH-3 T3 cells. The complex TGS 121 turned out to be non-toxic for NIH-3 T3 cells and to induce death and alternations in Ras-hyperactivated cells. We found induction of ER stress, mitochondria swelling, proteasome inhibition, and cell cycle block. Moreover, TGS 121 inhibited cell migration and induced the accumulation of perinuclear organelles that was secondary to proteasome inhibition. Results presented in this report suggest that stable gold-cyanide TGS 121 complex is non-toxic, with a targeted mechanism of action and it is promising in anticancer drug discovery.

Multiple Genes with Potential Tumor Suppressive Activity Are Present on Chromosome 10q Loss in Neuroblastoma and Are Associated with Poor Prognosis

Neuroblastoma (NB) is a tumor affecting the peripheral sympathetic nervous system that substantially contributes to childhood cancer mortality. Despite recent advances in understanding the complexity of NB, the mechanisms determining its progression are still largely unknown. Some recurrent segmental chromosome aberrations (SCA) have been associated with poor survival. However, the prognostic role of most SCA has not yet been investigated. We examined a cohort of 260 NB primary tumors at disease onset for the loss of chromosome 10q, by array-comparative genomic hybridization (a-CGH) and Single Nucleotide Polymorphism (SNP) array and we found that 26 showed 10q loss, while the others 234 displayed different SCA. We observed a lower event-free survival for NB patients displaying 10q loss compared to patients with tumors carrying other SCA. Furthermore, analyzing the region of 10q loss, we identified a cluster of 75 deleted genes associated with poorer outcome. Low expression of six of these genes, above all CCSER2, was significantly correlated to worse survival using in silico data from 786 NB patients. These potential tumor suppressor genes can be partly responsible for the poor prognosis of NB patients with 10q loss.

IFIT2 Depletion Promotes Cancer Stem Cell-like Phenotypes in Oral Cancer

(1) Background: Cancer stem cells (CSCs) are a small cell population associated with chemoresistance, metastasis and increased mortality rate in oral cancer. Interferon-induced proteins with tetratricopeptide repeats 2 (IFIT2) depletion results in epithelial to mesenchymal transition, invasion, metastasis, and chemoresistance in oral cancer. To date, no study has demonstrated the effect of IFIT2 depletion on the CSC-like phenotype in oral cancer cells. (2) Methods: Q-PCR, sphere formation, Hoechst 33,342 dye exclusion, immunofluorescence staining, and flow cytometry assays were performed to evaluate the expression of the CSC markers in IFIT2-depleted cells. A tumorigenicity assay was adopted to assess the tumor formation ability. Immunohistochemical staining was used to examine the protein levels of IFIT2 and CD24 in oral cancer patients. (3) Results: The cultured IFIT2 knockdown cells exhibited an overexpression of ABCG2 and CD44 and a downregulation of CD24 and gave rise to CSC-like phenotypes. Clinically, there was a positive correlation between IFIT2 and CD24 in the patients. IFIT2high/CD24high/CD44low expression profiles predicted a better prognosis in HNC, including oral cancer. The TNF-α blockade abolished the IFIT2 depletion-induced sphere formation, indicating that TNF-α may be involved in the CSC-like phenotypes in oral cancer. (4) Conclusions: The present study demonstrates that IFIT2 depletion promotes CSC-like phenotypes in oral cancer.

How Different Pathologies Are Affected by IFIT Expression

The type-I interferon (IFN) system represents the first line of defense against viral pathogens. Recognition of the virus initiates complex signaling pathways that result in the transcriptional induction of IFNs, which are then secreted. Secreted IFNs stimulate nearby cells and result in the production of numerous proinflammatory cytokines and antiviral factors. Of particular note, IFN-induced tetratricopeptide repeat (IFIT) proteins have been thoroughly studied because of their antiviral activity against different viral pathogens. Although classically studied as an antiviral protein, IFIT expression has recently been investigated in the context of nonviral pathologies, such as cancer and sepsis. In oral squamous cell carcinoma (OSCC), IFIT1 and IFIT3 promote metastasis, while IFIT2 exhibits the opposite effect. The role of IFIT proteins during bacterial/fungal sepsis is still under investigation, with studies showing conflicting roles for IFIT2 in disease severity. In the setting of viral sepsis, IFIT proteins play a key role in clearing viral infection. As a result, many viral pathogens, such as SARS-CoV-2, employ mechanisms to inhibit the type-I IFN system and promote viral replication. In cancers that are characterized by upregulated IFIT proteins, medications that decrease IFIT expression may reduce metastasis and improve survival rates. Likewise, in cases of viral sepsis, therapeutics that increase IFIT expression may improve viral clearance and reduce the risk of septic shock. By understanding the effect of IFIT proteins in different pathologies, novel therapeutics can be developed to halt disease progression.

STAT1/IFIT2 signaling pathway is involved in PD-L1-mediated epithelial-to-mesenchymal transition in human esophageal cancer

Background

We have previously reported significant change of epithelial to mesenchymal transition (EMT) phenotype of Eca-109 cells upon PD-L1 operation, and the cytoplasmic domain of PD-L1 played an essential role in promoting EMT of esophageal cancer cells. However, the underlying mechanism of how PD-L1 regulated EMT in esophageal cancer remained unclear.

Methods

The overexpression and knockdown expression models of PD-L1 and IFIT2 were established by using lenti-virus transfection and RNAi method. Western blotting, qRT-PCR, CCK8 assay, transwell assay and wound healing assay were chosen to investigate their impact on the cells. The expression levels of IFIT2 and EMT markers in esophageal cancer tissues were examined by immunohistochemical staining. The rescue experiments were further applied to investigate the role of STAT1/IFIT2 signal pathway in the PD-L1-mediated EMT. Luciferase reporter assays were performed to examine the IFIT2 promoter activities upon knockdown expression of PD-L1 to identify the putative targeted region of IFIT2 promoter.

Results

The STAT1/IFIT2 signal pathway was activated when PD-L1 was knockdown in human esophageal cancer cells. Decreased IFIT2 expression significantly increased the cellular abilities of viability, invasion and migration by using RNAi method in human esophageal cancer cells. Decreased IFIT2 expression in esophageal cancer tissues significantly correlated with EMT status, and could be used as an independent prognostic predictor for the patients. Rescue experiments in PD-L1 knockdown cells further confirmed that STAT1/IFIT2 pathway was involved in the PD-L1 mediated EMT of esophageal cancer cells. Moreover, the luciferase reporter assay also confirmed that in esophageal cancer cells, the promoter region of IFIT2 (-3K~-1K) remains more active in PD-L1 knockdown expression cells compared with controls.

Conclusion

Our present work reveals a novel mechanism of how PD-L1 regulates EMT of cancer cells, namely STAT1/IFIT2 signal pathway is required in PD-L1 mediated EMT in human esophageal cancer.

Identified Three Interferon Induced Proteins as Novel Biomarkers of Human Ischemic Cardiomyopathy

Ischemic cardiomyopathy is the most frequent type of heart disease, and it is a major cause of myocardial infarction (MI) and heart failure (HF), both of which require expensive medical treatment. Precise biomarkers and therapy targets must be developed to enhance improve diagnosis and treatment. In this study, the transcriptional profiles of 313 patients' left ventricle biopsies were obtained from the PubMed database, and functional genes that were significantly related to ischemic cardiomyopathy were screened using the Weighted Gene Co-Expression Network Analysis and protein-protein interaction (PPI) networks enrichment analysis. The rat myocardial infarction model was developed to validate these findings. Finally, the putative signature genes were blasted through the common Cardiovascular Disease Knowledge Portal to explore if they were associated with cardiovascular disorder. Three interferon stimulated genes (IFIT2, IFIT3 and IFI44L), as well as key pathways, have been identified as potential biomarkers and therapeutic targets for ischemic cardiomyopathy, and their alternations or mutations have been proven to be strongly linked to cardiac disorders. These novel signature genes could be utilized as bio-markers or potential therapeutic objectives in precise clinical diagnosis and treatment of ischemic cardiomyopathy.

The impact of indole-3-lactic acid on immature intestinal innate immunity and development: a transcriptomic analysis

An excessive intestinal inflammatory response may have a role in the pathogenesis of necrotizing enterocolitis (NEC) in very preterm infants. Indole-3-lactic acid (ILA) of breastmilk tryptophan was identified as the anti-inflammatory metabolite involved in probiotic conditioned media from Bifidobacteria longum subsp infantis. This study aimed to explore the molecular endocytic pathways involved in the protective ILA effect against inflammation. H4 cells, Caco-2 cells, C57BL/6 pup and adult mice were used to compare the anti-inflammatory mechanisms between immature and mature enterocytes in vitro and in vivo. The results show that ILA has pleiotropic protective effects on immature enterocytes including anti-inflammatory, anti-viral, and developmental regulatory potentials in a region-dependent and an age-dependent manner. Quantitative transcriptomic analysis revealed a new mechanistic model in which STAT1 pathways play an important role in IL-1β-induced inflammation and ILA has a regulatory effect on STAT1 pathways. These studies were validated by real-time RT-qPCR and STAT1 inhibitor experiments. Different protective reactions of ILA between immature and mature enterocytes indicated that ILA's effects are developmentally regulated. These findings may be helpful in preventing NEC for premature infants.

Identification of Chemoresistance-Associated Key Genes and Pathways in High-Grade Serous Ovarian Cancer by Bioinformatics Analyses

Purpose

High-grade serous ovarian cancer (HGSOC) is the leading cause of death among gynecological malignancies. This is mainly attributed to its high rates of chemoresistance. To date, few studies have investigated the molecular mechanisms underlying this resistance to treatment in ovarian cancer patients. In this study, we aimed to explore these molecular mechanisms using bioinformatics analysis.

Methods

We analyzed microarray data set GSE51373, which included 16 platinum-sensitive HGSOC samples and 12 platinum-resistant control samples. Differentially expressed genes (DEGs) were identified using RStudio. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using DAVID, and a DEG-associated protein–protein interaction (PPI) network was constructed using STRING. Hub genes in the PPI network were identified, and the prognostic value of the top ten hub genes was evaluated. MGP, one of the hub genes, was verified by immunohistochemistry.

Results

All samples were confirmed to be of high quality. A total of 109 DEGs were identified, and the top ten enriched GO terms and four KEGG pathways were obtained. Specifically, the PI3K-AKT signaling pathway and the Rap1 signaling pathway were identified as having significant roles in chemoresistance in HGSOC. Furthermore, based on the PPI network, KIT, FOXM1, FGF2, HIST1H4D, ZFPM2, IFIT2, CCNO, MGP, RHOBTB3, and CDC7 were identified as hub genes. Five of these hub genes could predict the prognosis of HGSOC patients. Positive immunostaining signals for MGP were observed in the chemoresistant samples.

Conclusion

Taken together, the findings of this study may provide novel insights into HGSOC chemoresistance and identify important therapeutic targets.

Exome sequencing of familial high-grade serous ovarian carcinoma reveals heterogeneity for rare candidate susceptibility genes

High-grade serous ovarian carcinoma (HGSOC) has a significant hereditary component, approximately half of which cannot be explained by known genes. To discover genes, we analyse germline exome sequencing data from 516 BRCA1/2-negative women with HGSOC, focusing on genes enriched with rare, protein-coding loss-of-function (LoF) variants. Overall, there is a significant enrichment of rare protein-coding LoF variants in the cases (p < 0.0001, chi-squared test). Only thirty-four (6.6%) have a pathogenic variant in a known or proposed predisposition gene. Few genes have LoF mutations in more than four individuals and the majority are detected in one individual only. Forty-three highly-ranked genes are identified with three or more LoF variants that are enriched by three-fold or more compared to GnomAD. These genes represent diverse functional pathways with relatively few involved in DNA repair, suggesting that much of the remaining heritability is explained by previously under-explored genes and pathways.

Overexpression of IFIT2 inhibits the proliferation of chronic myeloid leukemia cells by regulating the BCR‑ABL/AKT/mTOR pathway

Chronic myeloid leukemia (CML) is a myeloproliferative disorder that accounts for ~10% of all newly diagnosed leukemia cases. Early diagnosis is essential for long‑term beneficial outcomes. The present study observed that interferon‑induced protein with tetratricopeptde repeats 2 (IFIT2) expression levels were reduced in bone marrow samples from CML patients compared with control samples using RNA sequencing and reverse transcription‑PCR. IFIT2 expression levels were restored in patients treated with tyrosine kinase inhibitors. To investigate the effect of IFIT2 on CML patients, a stable IFIT2 expressing K562 cell line was established. It was demonstrated that IFIT2 overexpression in K562 cells inhibits cell proliferation and arrests the cell cycle at the G1 phase. In addition, it was demonstrated by western blotting that IFIT2 inhibits the BCR‑ABL oncoprotein and regulates its downstream AKT/mTOR signaling pathway. IFIT2 could induce cell cycle arrest‑associated gene p27kip1 by degrading cullin1‑mediated E3 ligases. In summary, the present study demonstrated that IFIT2 was efficacious in inhibiting CML and is a potential therapeutic target.

Emerging Functions of Human IFIT Proteins in Cancer

Interferon-induced protein with tetratricopeptide repeats (IFIT) genes are prominent interferon-stimulated genes (ISGs). The human IFIT gene family consists of four genes named IFIT1, IFIT2, IFIT3, and IFIT5. The expression of IFIT genes is very low in most cell types, whereas their expression is greatly enhanced by interferon treatment, viral infection, and pathogen-associated molecular patterns (PAMPs). The proteins encoded by IFIT genes have multiple tetratricopeptide repeat (TPR) motifs. IFIT proteins do not have any known enzymatic roles. However, they execute a variety of cellular functions by mediating protein-protein interactions and forming multiprotein complexes with cellular and viral proteins through their multiple TPR motifs. The versatile tertiary structure of TPR motifs in IFIT proteins enables them to be involved in distinct biological functions, including host innate immunity, antiviral immune response, virus-induced translation initiation, replication, double-stranded RNA signaling, and PAMP recognition. The current understanding of the IFIT proteins and their role in cellular signaling mechanisms is limited to the antiviral immune response and innate immunity. However, recent studies on IFIT protein functions and their involvement in various molecular signaling mechanisms have implicated them in cancer progression and metastasis. In this article, we focused on critical molecular, biological and oncogenic functions of human IFIT proteins by reviewing their prognostic significance in health and cancer. Research suggests that IFIT proteins could be novel therapeutic targets for cancer therapy.

Decreased IFIT2 Expression In Human Non-Small-Cell Lung Cancer Tissues Is Associated With Cancer Progression And Poor Survival Of The Patients

Background

IFIT2 (interferon-induced proteins with tetratricopeptide repeats 2), also known as ISG54, is an important interferon-stimulated gene family protein, which has been confirmed to play a crucial role in anti-cancer as well as anti-virus process. In the present study, we aimed to investigate the IFIT2 expression in human non-small-cell cancer (NSCLC) tissues and its clinical implications.

Methods

The immunohistochemistry assay was used to identify the clinical significance and prognostic value of IFIT2 expression in NSCLC tissues. The depletion of IFIT2 was achieved using RNAi approach to assess the role of IFIT2 in the regulation of biological behaviors in human lung cancer cell lines.

Results

Decreased IFIT2 expression was found in human NSCLC tissues (both in lung adenocarcinoma and lung squamous cell carcinoma) in contrast to the adjacent normal tissues (both P<0.0001, respectively). We did not find any significant correlations between the IFIT2 expression and patient’s clinicopathological features. The survival analysis showed that the overall survival (OS) of patients in IFIT2 low expression group was significantly poorer than that in IFIT2 high expression group (in lung adenocarcinoma: P=0.027; and in lung squamous cell carcinoma: P=0.029). The Cox model analysis also indicated that the distant metastasis (P=0.043) could be used as an independent prognostic factor for lung adenocarcinoma patients, and the lymph node metastasis (P=0.045) and IFIT2 low expression (P=0.020) could be used as independent prognostic factors for lung squamous cell carcinoma patients. Moreover, the depletion of IFIT2 in human lung cancer cell lines A549, H1975 and SK-MES-1 significantly increased the cellular abilities, such as viability, migration and invasion.

Conclusion

Decreased IFIT2 was involved in the initiation and the progression of human NSCLC, and its underlying mechanisms still needs further investigation.

Mechanisms of IFNalpha-1a-Induced Apoptosis in a Laryngeal Cancer Cell Line

Background

Interferon alpha (IFNalpha) exerts its anti-proliferative effect on many human cancers. Among the 13 subtypes of human IFNalpha, IFNalpha-1 subtype has 2 variants, named IFNalpha-1a and IFNalpha-1b, that differ from each other in only 1 amino acid, at residue 114. However, the mechanism by which IFNalpha-1a mediates growth inhibition is still unclear.

Material/Methods

Human laryngeal carcinoma HEp2 cells were treated with IFNalpha-1a by either transient transfection or exogenous delivery. Western blot and RT-PCR analysis were carried out to assess apoptotic pathways active in IFNalpha-1a-treated HEp2 cells. Microarray analysis was conducted to uncover the differential gene expressions after IFNalpha-1a treatment. KEGG pathway enrichment analysis was also performed.

Results

IFNalpha-1a markedly inhibited the proliferation and significantly promoted the apoptosis of HEp-2 cells. Mechanistic studies indicate that IFNalpha-1a-mediated cell apoptosis is directly linked to intrinsic and endoplasmic reticulum (ER) stress-related apoptosis, but is independent of extrinsic apoptosis. The top 40 differentially expressed genes discovered by microarray analysis included 20 upregulated genes (e.g., IFI6, IFI27, IFI44L, and MIR548X) and 20 downregulated genes (e.g., PRKDC, HIST1H3B, DYNC1H1, and HIST1H2AM). KEGG pathway enrichment analysis revealed that 4 out of 6 pathways are TP53-related.

Conclusions

We demonstrated a detailed mechanism involved in IFNalpha-1a-mediated anti-proliferation activity in human laryngeal carcinoma cells.

Integrated miRNA and mRNA transcriptomes of spleen profiles between Yorkshire and Queshan black pigs

Disease causes large economic losses to the pig industry worldwidely, immunity plays an important role in the process of resistance to disease. In the present study, to elucidate the molecular mechanisms underlying different levels of disease resistance, we obtained the miRNA and mRNA expression profiles from the spleens of three groups of sows, including 180-day-old Queshan Black (Q-F), 3-day-old Yorkshire (Y-N) and 180-day-old Yorkshire (Y-F) pigs. The results showed that 85 miRNAs and 5093 genes were differentially expressed in Y-F vs Y-N, and 20 miRNAs and 1283 genes were differentially expressed in Q-F vs Y-F. Gene ontology analysis of these differentially expressed genes revealed their critical roles in response to immune response-related signaling pathways. To investigate the molecular mechanisms underlying immune diversity based on differentially expressed miRNAs and genes, the regulatory network between the node miRNAs and genes were established using Cytoscape. The results showed that the identified candidate miRNAs and genes were associated with immune response, and also indicated their potential roles in disease resistance variance between different pig breeds and stages. From the above, this research detected the key factors that were involved in disease resistance, and provide useful information for disease resistance breeding.

Better together: the role of IFIT protein-protein interactions in the antiviral response

The interferon-induced proteins with tetratricopeptide repeats (IFITs) are a family of antiviral proteins conserved throughout all vertebrates. IFIT1 binds tightly to non-self RNA, particularly capped transcripts lacking methylation on the first cap-proximal nucleotide, and inhibits their translation by out-competing the cellular translation initiation apparatus. This exerts immense selection pressure on cytoplasmic RNA viruses to maintain mechanisms that protect their messenger RNA from IFIT1 recognition. However, it is becoming increasingly clear that protein-protein interactions are necessary for optimal IFIT function. Recently, IFIT1, IFIT2 and IFIT3 have been shown to form a functional complex in which IFIT3 serves as a central scaffold to regulate and/or enhance the antiviral functions of the other two components. Moreover, IFITs interact with other cellular proteins to expand their contribution to regulation of the host antiviral response by modulating innate immune signalling and apoptosis. Here, we summarize recent advances in our understanding of the IFIT complex and review how this impacts on the greater role of IFIT proteins in the innate antiviral response.