The Impact of MicroRNA-223-3p on IL-17 Receptor D Expression in Synovial Cells

Role of MicroRNAs in Inflammatory Joint Diseases: A Review

Inflammatory arthritis commonly initiates in the soft tissues lining the joint. This lining swells, as do the cells in it and inside the joint fluid, producing chemicals that induce inflammation signs such as heat, redness, and swelling. MicroRNA (miRNA), a subset of non-coding small RNA molecules, post-transcriptionally controls gene expression by targeting their messenger RNA. MiRNAs modulate approximately 1/3 of the human genome with their multiple targets. Recently, they have been extensively studied as key modulators of the innate and adaptive immune systems in diseases such as allergic disorders, types of cancer, and cardiovascular diseases. However, research on the different inflammatory joint diseases, such as rheumatoid arthritis, gout, Lyme disease, ankylosing spondylitis, and psoriatic arthritis, remains in its infancy. This review presents a deeper understanding of miRNA biogenesis and the functions of miRNAs in modulating the immune and inflammatory responses in the above-mentioned inflammatory joint diseases. According to the literature, it has been demonstrated that the development of inflammatory joint disorders is closely related to different miRNAs and their specific regulatory mechanisms. Furthermore, they may present as possible prognostic and diagnostic biomarkers for all diseases and may help in developing a therapeutic response. However, further studies are needed to determine whether manipulating miRNAs can influence the development and progression of inflammatory joint disorders.

TMIGD1: Emerging functions of a tumor supressor and adhesion receptor

The development of multicellular organisms depends on cell adhesion molecules (CAMs) that connect cells to build tissues. The immunoglobulin superfamily (IgSF) constitutes one of the largest families of CAMs. Members of this family regulate such diverse processes like synapse formation, spermatogenesis, leukocyte-endothelial interactions, or epithelial cell-cell adhesion. Through their extracellular domains, they undergo homophilic and heterophilic interactions in cis and trans. Their cytoplasmic domains frequently bind scaffolding proteins to assemble signaling complexes. Transmembrane and immunoglobulin domain-containing protein 1 (TMIGD1) is a IgSF member with two Ig-like domains and a short cytoplasmic tail that contains a PDZ domain-binding motif. Recent observations indicate that TMIGD1 has pleiotropic functions in epithelial cells and has a critical role in suppressing malignant cell behavior. Here, we review the molecular characteristics of TMIGD1, its interaction with cytoplasmic scaffolding proteins, the regulation of its expression, and its downregulation in colorectal and renal cancers.

Regulating of LncRNA2264/miR-20b-5p/IL17RD axis on hydrogen sulfide exposure-induced inflammation in broiler thymus by activating MYD88/NF-κB pathway

Hydrogen sulfide (H₂S) is an environmental pollutant. Chronic exposure to H₂S can damage the immune system of birds, but the detailed mechanisms of H₂S-induced thymus toxicity have not been determined. Competitive endogenous RNA (ceRNA) mechanism participates in many pathophysiological processes by regulating gene expression, including environmental pollutant-induced injury. Therefore, we investigate the specific mechanisms of ceRNA in the process of H₂S-induced thymic immune damage in broiler chickens. In the current study, 120 one-day-old male Ross 308 broilers were randomly divided into two groups (n = 60 chickens/group), raising in the control chamber (0.5 ± 0.5 ppm) or H₂S-exposed chamber (4.0 ± 0.5 ppm at 0-3 weeks of age and 20.0 ± 0.5 ppm at 4-6 weeks of age groups) to replicate the H₂S-exposed broilers. NaHS (3 mM or 6 mM) was used to treat chicken macrophages (HD11) to establish an in vitro. Histopathology and ultrastructural changes of thymus were assessed by hematoxylin and eosin (H&E) staining and transmission electron microscopy (TEM). Gene expression profiles were analyzed by using transcriptomics. The underlying mechanisms of thymic injury were further revealed by dual luciferase reporter gene assay, qRT-PCR and Western blotting. Research results showed that H₂S exposure induced an inflammatory response in thymus, with the expression of LncRNA2264 was significantly down-regulated. LncRNA2264 could competitively bind to miR-20b-5p and caused downregulation of the IL17RD. H₂S could activate inflammatory factors through the LncRNA2264/miR-20b-5p/IL17RD axis. In summary, this study suggested that LncRNA2264 acted as a miR-20b-5p molecular sponge to regulate the expression of IL17RD involved in H₂S exposure-induced thymic inflammation, which has positive implications for guiding the prevention and control of H₂S gas poisoning in livestock housing and ensuring animal welfare.

Prediction and analysis of microRNAs involved in COVID-19 inflammatory processes associated with the NF-kB and JAK/STAT signaling pathways

COVID-19 is the cause of a pandemic associated with substantial morbidity and mortality. As yet, there is no available approved drug to eradicate the virus. In this review article, we present an alternative study area that may contribute to the development of therapeutic targets for COVID-19. Growing evidence is revealing further pathophysiological mechanisms of COVID-19 related to the disregulation of inflammation pathways that seem to play a critical role toward COVID-19 complications. The NF-kB and JAK/STAT signaling pathways are highly activated in acute inflammation, and the excessive activity of these pathways in COVID-19 patients likely exacerbates the inflammatory responses of the host. A group of non-coding RNAs (miRNAs) manage certain features of the inflammatory process. In this study, we discuss recent advances in our understanding of miRNAs and their connection to inflammatory responses. Additionally, we consider the link between perturbations in miRNA levels and the onset of COVID-19 disease. Furthermore, previous studies published in the online databases, namely web of science, MEDLINE (PubMed), and Scopus, were reviewed for the potential role of miRNAs in the inflammatory manifestations of COVID-19. Moreover, we disclosed the interactions of inflammatory genes using STRING DB and designed interactions between miRNAs and target genes using Cityscape software. Several miRNAs, particularly miR-9, miR-98, miR-223, and miR-214, play crucial roles in the regulation of NF-kB and JAK-STAT signaling pathways as inflammatory regulators. Therefore, this group of miRNAs that mitigate inflammatory pathways can be further regarded as potential targets for far-reaching-therapeutic strategies in COVID-19 diseases.

Functional Evaluation of Anti-TNF-α Affibody Molecules in Biochemical Detection and Inhibition to Signalling Pathways of a Synovial Cell

BACKGROUND

An affibody molecule obtained from a bioengineered staphylococcal protein was previously shown to act as an affinity binder for a wide range of targets and develop Tumour Necrosis Factor α (TNF-α)-binding clones.

METHODS

In this study, we demonstrated that affibody molecules against TNF-α could bind to recombinant TNF-α on the membrane for biochemical detection. In addition, we examined whether the affibody molecules could block binding between recombinant TNF-α and its receptor on MH7A synovial cells.

RESULTS

When a TNF-α-binding affibody was added, the production level of inflammatory mediators IL-6 and MMP-3 in MH7A were found to decrease up to 44%. Additionally, proliferation of synovial cells was also inhibited by the addition of TNF-α to cultivation media.

CONCLUSION

These results suggest that affibody molecules against TNF-α could be candidate molecules for the detection of TNF-α during biochemical analysis and pharmacotherapy for rheumatoid arthritis.

Regulation of stability and inhibitory activity of the tumor suppressor SEF through casein-kinase II-mediated phosphorylation

Inflammation and cancer are intimately linked. A key mediator of inflammation is the transcription-factor NF-κB/RelA:p50. SEF (also known as IL-17RD) is a feedback antagonist of NF-κB/RelA:p50 that is emerging as an important link between inflammation and cancer. SEF acts as a buffer to prevent excessive NF-κB activity by sequestering NF-κB/RelA:p50 in the cytoplasm of unstimulated cells, and consequently attenuating the NF-κB response upon pro-inflammatory cytokine stimulation. SEF contributes to cancer progression also via modulating other signaling pathways, including those triggered by growth-factors. Despite its important role in human physiology and pathology, mechanisms that regulate SEF biochemical properties and inhibitory activity are unknown. Here we show that human SEF is an intrinsically labile protein that is stabilized via CK2-mediated phosphorylation, and identified the residues whom phosphorylation by CK2 stabilizes hSEF. Unlike endogenous SEF, ectopic SEF was rapidly degraded when overexpressed but was stabilized in the presence of excess CK2, suggesting a mechanism for limiting SEF levels depending upon CK2 processivity. Additionally, phosphorylation by CK2 potentiated hSef interaction with NF-κB in cell-free binding assays. Most importantly, we identified a CK2 phosphorylation site that was indispensable for SEF inhibition of pro-inflammatory cytokine signaling but was not required for SEF inhibition of growth-factor signaling. To our knowledge, this is the first demonstration of post-translational modifications that regulate SEF at multiple levels to optimize its inhibitory activity in a specific signaling context. These findings may facilitate the design of SEF variants for treating cytokine-dependent pathologies, including cancer and chronic inflammation.

Regulation of Osteoclastogenesis and Bone Resorption by miRNAs

Osteoclasts are specialized bone-resorbing cells that contribute to physiological bone development and remodeling in bone metabolism throughout life. Abnormal production and activation of osteoclasts lead to excessive bone resorption in pathological conditions, such as in osteoporosis and in arthritic diseases with bone destruction. Recent epigenetic studies have shed novel insight into the dogma of the regulation of gene expression. microRNAs belong to a category of epigenetic regulators, which post-transcriptionally regulate and silence target gene expression, and thereby control a variety of biological events. In this review, we discuss miRNA biogenesis, the mechanisms utilized by miRNAs, several miRNAs that play important roles in osteoclast differentiation, function, survival and osteoblast-to-osteoclast communication, and their translational potential and challenges in bone biology and skeletal diseases.

miR-223: An Effective Regulator of Immune Cell Differentiation and Inflammation

MicroRNAs (miRNAs) play a critical role in regulating various biological processes, such as cell differentiation and immune modulation by binding to their target genes. miR-223 is a miRNA with important functions and has been widely investigated in recent years. Under certain physiological conditions, miR-223 is regulated by different transcription factors, including sirtuin1 (Sirt1), PU.1 and Mef2c, and its biological functions are mediated through changes in its cellular or tissue expression. This review paper summarizes miR-223 biosynthesis and its regulatory role in the differentiation of granulocytes, dendritic cells (DCs) and lymphocytes, macrophage polarization, and endothelial and epithelial inflammation. In addition, it describes the molecular mechanisms of miR-223 in regulating lung inflammation, rheumatoid arthritis, enteritis, neuroinflammation and mastitis to provide insights into the existing molecular regulatory networks and therapies for inflammatory diseases in humans and animals.

Interleukin-17 receptor D (Sef) is a multi-functional regulator of cell signaling

Interleukin-17 receptor D (IL17RD or IL-17RD) also known as Sef (similar expression to fibroblast growth factor), is a single pass transmembrane protein that is reported to regulate several signaling pathways . IL17RD was initially described as a feedback inhibitor of fibroblast growth factor (FGF) signaling during zebrafish and frog development. It was subsequently determined to regulate other receptor tyrosine kinase signaling cascades as well as several proinflammatory signaling pathways including Interleukin-17A (IL17A), Toll-like receptors (TLR) and Interleukin-1α (IL1α) in several vertebrate species including humans. This review will provide an overview of IL17RD regulation of signaling pathways and functions with emphasis on regulation of development and pathobiological conditions. We will also discuss gaps in our knowledge about IL17RD function to provide insight into opportunities for future investigation.

Reduced Platelet miR-223 Induction in Kawasaki Disease Leads to Severe Coronary Artery Pathology Through a miR-223/PDGFRβ Vascular Smooth Muscle Cell Axis

RATIONALE

Kawasaki disease (KD) is an acute vasculitis of early childhood that can result in permanent coronary artery structural damage. The cause for this arterial vulnerability in up to 15% of patients with KD is unknown. Vascular smooth muscle cell dedifferentiation play a key role in the pathophysiology of medial damage and aneurysm formation, recognized arterial pathology in KD. Platelet hyperreactivity is also a hallmark of KD. We recently demonstrated that uptake of platelets and platelet-derived miRNAs influences vascular smooth muscle cell phenotype in vivo.

OBJECTIVE

We set out to explore whether platelet/vascular smooth muscle cell (VSMC) interactions contribute to coronary pathology in KD.

METHODS AND RESULTS

We prospectively recruited and studied 242 patients with KD, 75 of whom had documented coronary artery pathology. Genome-wide miRNA sequencing and droplet digital PCR demonstrated that patient with KD platelets have significant induction of miR-223 compared with healthy controls (HCs). Platelet-derived miR-223 has recently been shown to promote vascular smooth muscle quiescence and resolution of wound healing after vessel injury. Paradoxically, patients with KD with the most severe coronary pathology (giant coronary artery aneurysms) exhibited a lack of miR-223 induction. Hyperactive platelets isolated from patients with KD are readily taken up by VSMCs, delivering functional miR-223 into the VSMCs promoting VSMC differentiation via downregulation of PDGFRβ (platelet-derived growth factor receptor β). The lack of miR-223 induction in patients with severe coronary pathology leads to persistent VSMC dedifferentiation. In a mouse model of KD (Lactobacillus casei cell wall extract injection), miR-223 knockout mice exhibited increased medial thickening, loss of contractile VSMCs in the media, and fragmentation of medial elastic fibers compared with WT mice, which demonstrated significant miR-223 induction upon Lactobacillus casei cell wall extract challenge. The excessive arterial damage in the miR-223 knockout could be rescued by adoptive transfer of platelet, administration of miR-223 mimics, or the PDGFRβ inhibitor imatinib mesylate. Interestingly, miR-223 levels progressively increase with age, with the lowest levels found in <5-year-old. This provides a basis for coronary pathology susceptibility in this very young cohort.

CONCLUSIONS

Platelet-derived miR-223 (through PDGFRβ inhibition) promotes VSMC differentiation and resolution of KD induced vascular injury. Lack of miR-223 induction leads to severe coronary pathology characterized by VSMC dedifferentiation and medial damage. Detection of platelet-derived miR-223 in patients with KD (at the time of diagnosis) may identify patients at greatest risk of coronary artery pathology. Moreover, targeting platelet miR-223 or VSMC PDGFRβ represents potential therapeutic strategies to alleviate coronary pathology in KD. Graphic Abstract: A graphic abstract is available for this article.

Aerobic Exercise Inhibits CUMS-Depressed Mice Hippocampal Inflammatory Response via Activating Hippocampal miR-223/TLR4/MyD88-NF-κB Pathway

Objective: To investigate the role of aerobic exercise in inhibiting chronic unpredictable mild stress (CUMS) depressed mice hippocampal inflammatory response and its potential mechanisms. Methods: Fifty-four male eight-week-old C57BL/6 mice were divided as control group (CG) (18 mice) and model group (36 mice). Model group mice were treated with 13 chronic stimulating factors for 28 days to set up the CUMS depression model. Neurobehavioral assessment was performed after modeling. The mice in the model group were randomly divided into the control model group (MG) and the aerobic exercise group (EG), with 18mice in each group. The EG group carried out the adaptive training of the running platform: 10 m/min, 0° slope, and increased by 10 minutes per day for 6 days. The formal training was carried for 8 weeks with 10 m/min speed, 0° slope, 60 min/d, 6 d/Week. After the training, a neurobehavioral assessment was performed, and hippocampus IL-1β and IL-10 protein levels were detected by ELISA. RT–PCR was used to detect the expression of miR-223 and TLR4, MyD88, and NF-κB in the hippocampus. Western blot was used to detect the expression of TLR4 and phosphorylated NF-κBp65 protein in the hippocampus. Results: The hippocampus function of CUMS depression model mice was impaired. The forced swimming and forced tail suspension time were significantly prolonged, and inflammatory factors IL-1β were significantly increased in the hippocampus. Aerobic exercise significantly improves CUMS-depressed mice hippocampal function, effectively reducing depressive behavior and IL-1β levels, and increasing IL-10 levels. Besides, aerobic exercise significantly upregulates the expression level of miR-223 and inhibits the high expression of TLR4, MyD88, and NF-κB. Conclusion: Aerobic exercise significantly increases the CUMS-depressed mice hippocampus expression of miR-223, and inhibits the downstream TLR4/MyD88-NF-κB signaling pathway and the hippocampal inflammatory response, which contributes to the improvement of the hippocampal function.

Functional Regulation of Macrophage Phenotypes by MicroRNAs in Inflammatory Arthritis

Inflammatory arthritis including rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA) exhibit the shared feature of changes in activation and polarization of circulating monocytes and tissue macrophages. Numerous microRNAs (miRs) have been found to have key functions in regulating inflammation and macrophage polarization. Although there is increasing interest in the roles of miRs in both RA and JIA, less is known regarding how miRs relate to functional properties of immune cells, including monocytes and macrophages. Interestingly, miRs can function both to promote inflammatory phenotypes and pro-inflammatory polarization, as well as through negative-feedback loops to limit inflammation. Here, we review the functional roles of several miRs in macrophages in inflammatory arthritis, with a particular focus on vivo effects of miR alteration in experimental arthritis. We also consider how current efforts to target miRs clinically could modify functional monocyte and macrophage polarization in vivo, and serve as novel therapies for diseases such as RA and JIA.

MicroRNAs in rheumatoid arthritis: From pathogenesis to clinical impact

Over the last decade, many epigenetic mechanisms that contribute in the pathogenesis of autoimmune disorders have been revealed. MicroRNAs (miRNAs) are small, non-coding, RNA molecules that bind to messenger RNAs and disrupt the transcription of target genes. Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease in which a plethora of epigenetic changes take place. Current research on RA epigenetics has focused mainly on miRNAs. Genetic variance of some miRNA genes, especially miR-499, might predispose an individual to RA development. Additionally, altered expression of many miRNAs has been discovered in several cells, tissues and body fluids in patients with RA. MiRNAs expression also differs depending on disease's stage and activity. Serum miR-22 and miR-103a might predict RA development in susceptible individuals (pre-RA), while serum miR-16, miR-24, miR-125a and miR-223 levels are altered in early RA (disease duration <12 months) patients compared to established RA or healthy individuals. Moreover, serum miR-223 levels have been associated with RA activity and disease relapse. What is more, serum levels of several miRNAs, including miR-125b and miR-223, could be used to predict response to RA treatment. Finally, miRNA analogs or antagonists have been used as therapeutic regimens in experimental arthritis models and have demonstrated promising results. In conclusion, the research on the miRNA alterations in RA sheds light to several aspects of RA pathogenesis, introduces new biomarkers for RA diagnosis and treatment response prediction and offers the opportunity to discover new, targeted drugs for patients with RA.

Expression of microRNAs in the plasma of patients with acute gouty arthritis and the effects of colchicine and etoricoxib on the differential expression of microRNAs

INTRODUCTION

To determine the microRNA (miRNA) expression profiles in the plasma of acute gouty arthritis (AGA) patients and investigate the effects of colchicine and etoricoxib treatment on the differential expression of miRNAs.

MATERIAL AND METHODS

Exiqon miRCURYLNA microRNA Array was used for miRNA expression profiling in AGA. Two of the 21 differentially expressed miRNAs were confirmed using quantitative real-time polymerase chain reaction (qRT-PCR). A randomized, double-blind, parallel-controlled design was used to divide 160 AGA patients into colchicine and etoricoxib groups. Changes in 2 differentially expressed miRNAs, interleukin-1 (IL-1) β, cyclooxygenase-2 (COX-2) and joint pain scores were detected.

RESULTS

Compared with normal subjects and asymptomatic hyperuricemia (HUA) patients, plasma of AGA contained 21 differentially expressed miRNAs. qRT-PCR indicated specific downregulation of miR-223-3p and miR-451a in AGA. There were no statistically significant differences in the baseline characteristics between colchicine and etoricoxib groups. Furthermore, no significant difference in joint pain scores after 5- and 10-day treatment were found between groups (p > 0.05). Comparison of differences between pre- and 5-day post-treatment values confirmed that the upregulation of miR-223-3p and downregulation of IL-1β induced by colchicine were more significant than etoricoxib (p < 0.05). However, the latter outperformed the former in the upregulation of miR-451a and downregulation of COX-2 (p < 0.05). After 10-day treatment, the magnitude of miR-223-3p upregulation and IL-1β downregulation in the colchicine group was significantly higher than in the etoricoxib group, while the etoricoxib group had higher expression of miR-451a and lower expression of COX-2 than the colchicine group (p < 0.05).

CONCLUSIONS

In AGA patients, 21 differentially expressed miRNAs were detected in the plasma. Colchicine could upregulate miR-223-3p and downregulate IL-1β in the plasma, while etoricoxib may treat AGA by upregulating miR-451a and downregulating COX-2.

Impact of miR-223-3p and miR-2909 on inflammatory factors IL-6, IL-1ß, and TNF-α, and the TLR4/TLR2/NF-κB/STAT3 signaling pathway induced by lipopolysaccharide in human adipose stem cells

MicroRNAs (miRNAs) are small non-coding RNA molecules that play an important role in the regulation of gene expression related to inflammatory responses. Human adipose stem cells are characterized by pluripotent differentiation potential and isolated from adipose tissues. These cells regulate inflammation mainly by interacting with immune cells and affecting the secretion of immune factors; details of this interaction are currently unknown. In the current study, we successfully established an acute inflammation model and a chronic inflammation model involving adipose stem cells. We used high-throughput miRNA microarray analysis to identify miRNAs that were significantly (p < 0.05) differentially expressed during both acute and chronic inflammation. Lipopolysaccharide (LPS) significantly (p < 0.05) reduced the expression of miR-223-3P and miR-2909, while promoting the production of pro-inflammatory cytokines, interleukin (IL) 6, IL-1β, and tumor necrosis factor (TNF)-α via the Toll-like receptor (TLR) 4/TLR2/nuclear factor (NF)-κB/signal transducer and activator of transcription (STAT) 3 signaling pathway in human adipose stem cells. Further, miR-223-3P expression was significantly (p < 0.05) reduced in human adipose stem cells during activation by IL-6 stimulation. The inducible down-regulation of miR-223-3P resulted in the activation of STAT3, which was directly targeted by miR-223-3P. STAT3 directly targeted TLR4 and TLR2, promoting the production of the pro-inflammatory cytokine, IL-6, and formed a positive feedback loop to regulate IL-6 levels. Similarly, TNF-α significantly (p < 0.05) increased the expression of miR-223-3p, with LPS and TLR4/TLR2/NF-κB/STAT3 forming a negative feedback loop to regulate TNF-α levels. In addition, miR-2909, which depends on NF-κB, targeted Krueppel-like factor (KLF) 4 to regulate the levels of pro-inflammatory cytokines, IL-6, IL-1β, and TNF-α. We conclude that miR-223-3p and miR-2909 form a complex regulatory network with pro-inflammatory factors and signaling pathways in adipose stem cells stimulated by LPS. These findings will inform the development of therapies against autoimmune and inflammatory diseases.

MicroRNA regulation in blood cells of renal transplanted patients with interstitial fibrosis/tubular atrophy and antibody-mediated rejection

Interstitial fibrosis/tubular atrophy (IFTA) is associated with reduced allograft survival, whereas antibody-mediated rejection (ABMR) is the major cause for renal allograft failure. To identify specific microRNAs and their regulation involved in these processes, total RNA from blood cells of 16 kidney transplanted (KTx) patients with ABMR, stable graft function (SGF) and with T-cell mediated rejection (TCMR) was isolated. MicroRNA expression was determined by high-throughput sequencing. Differentially expressed candidate microRNAs were analyzed with RT-PCR in patients with SGF (n = 53), urinary tract infection (UTI) (n = 17), borderline rejection (BL) (n = 19), TCMR (n = 40), ABMR (n = 22) and IFTA (n = 30). From the 301 detected microRNAs, 64 were significantly regulated between the three cohorts. Selected candidate microRNAs miR-223-3p, miR-424-3p and miR-145-5p distinguished TCMR and ABMR from SGF, but not from other pathologies. Most importantly, miR-145-5p expression in IFTA patients was significantly downregulated and displayed a high diagnostic accuracy compared to SGF alone (AUC = 0.891) and compared to SGF, UTI, BL, TCMR and ABMR patients combined (AUC = 0.835), which was verified by cross-validation. The identification of miR-145-5p as IFTA specific marker in blood constitutes the basis for evaluating this potentially diagnostic microRNA as biomarker in studies including high numbers of patients and different pathologies and also the further analysis of fibrosis causing etiologies after kidney transplantation.

Necroptosis in 3-chloro-1, 2-propanediol (3-MCPD)-dipalmitate-induced acute kidney injury in vivo and its repression by miR-223-3p

Fatty acid esters of 3-chloro-1, 2-propanediol (3-MCPD) are a group of processing-induced food contaminants with nephrotoxicity. This study investigated whether and how necroptosis played a role in the nephrotoxic effect of 3-MCPD-dipalmitate (2.5 g/kg BW) in C57 BL/6 mice. The results showed that the principal components in necroptosis pathway including receptor-interacting protein 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like protein (MLKL) were up-regulated in 3-MCPD-dipalmitate-induced acute kidney injury (AKI). Deletion of RIPK3 or MLKL, and inhibition of RIPK1 suppressed AKI. The up-regulation of inflammatory cytokines in the kidney of 3-MCPD-dipalmitate treated mice were attenuated in RIPK3- or MLKL- deficient mice, suggesting a positive feedback loop involving necroptosis and inflammation. The microRNA analysis revealed that 38 known miRNAs and 40 novel miRNAs were differentially expressed (DE) in the kidney treated with 3-MCPD-dipalmitate. Of these miRNAs, miR-223-3p was significantly up-regulated during 3-MCPD-dipalmitate-induced AKI. In cultured mouse proximal tubular cells, a miR-223-3p mimic suppressed RIPK3 expression, which was blocked by miR-223-3p inhibitor. The luciferase reporter assay confirmed that miR-223-3p was able to inhibit RIPK3 expression by targeting the 3' un-translated region of RIPK3. These results suggest that necroptosis contributes to 3-MCPD-dipalmitate-induced acute kidney injury, and that may be attenuated by miR-223-3p.

Common microRNA⁻mRNA Interactions in Different Newcastle Disease Virus-Infected Chicken Embryonic Visceral Tissues

To investigate the roles and explore the altered expression of microRNAs (miRNAs) and mRNAs in chicken embryos in response to Newcastle disease virus (NDV) infection, deep sequencing was performed. Then, a conjoint analysis of small RNA-seq and mRNA-seq was performed to screen interactional miRNA⁻mRNA pairs during NDV infection. In total, 15 and 17 up- and downregulated miRNAs were identified that potentially targeted 4279 and 6080 mRNAs in NDV-infected chicken embryonic tissues, respectively; in addition, 595 upregulated and 480 downregulated mRNAs were identified. The conjoint analysis of the obtained data identified 1069 miRNA⁻mRNA pairs. Among these pairs, 130 pairs were related to immune or inflammatory responses. The relationship between gga-miR-203a and its target transglutaminase 2 (TGM2) was confirmed using a dual-luciferase reporter system and a real time quantitative polymerase chain reaction (RT-qPCR) assay. Overall, the discovery of miRNAs, mRNAs, and their potential pairing relationships, which may be involved in the regulation of NDV infection, will facilitate our understanding of the complex regulatory relationship between the host and the virus.