Illuminating the pathogenic role of SARS-CoV-2: Insights into competing endogenous RNAs (ceRNAs) regulatory networks

The appearance of SARS-CoV-2 in 2019 triggered a significant economic and health crisis worldwide, with heterogeneous molecular mechanisms that contribute to its development are not yet fully understood. Although substantial progress has been made in elucidating the mechanisms behind SARS-CoV-2 infection and therapy, it continues to rank among the top three global causes of mortality due to infectious illnesses. Non-coding RNAs (ncRNAs), being integral components across nearly all biological processes, demonstrate effective importance in viral pathogenesis. Regarding viral infections, ncRNAs have demonstrated their ability to modulate host reactions, viral replication, and host-pathogen interactions. However, the complex interactions of different types of ncRNAs in the progression of COVID-19 remains understudied. In recent years, a novel mechanism of post-transcriptional gene regulation known as "competing endogenous RNA (ceRNA)" has been proposed. Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and viral ncRNAs function as ceRNAs, influencing the expression of associated genes by sequestering shared microRNAs. Recent research on SARS-CoV-2 has revealed that disruptions in specific ceRNA regulatory networks (ceRNETs) contribute to the abnormal expression of key infection-related genes and the establishment of distinctive infection characteristics. These findings present new opportunities to delve deeper into the underlying mechanisms of SARS-CoV-2 pathogenesis, offering potential biomarkers and therapeutic targets. This progress paves the way for a more comprehensive understanding of ceRNETs, shedding light on the intricate mechanisms involved. Further exploration of these mechanisms holds promise for enhancing our ability to prevent viral infections and develop effective antiviral treatments.

ABBV-744 alleviates LPS-induced neuroinflammation via regulation of BATF2-IRF4-STAT1/3/5 axis

Suppression of neuroinflammation using small molecule compounds targeting the key pathways in microglial inflammation has attracted great interest. Recently, increasing attention has been gained to the role of the second bromodomain (BD2) of the bromodomain and extra-terminal (BET) proteins, while its effect and molecular mechanism on microglial inflammation has not yet been explored. In this study, we evaluated the therapeutic effects of ABBV-744, a BD2 high selective BET inhibitor, on lipopolysaccharide (LPS)-induced microglial inflammation in vitro and in vivo, and explored the key pathways by which ABBV-744 regulated microglia-mediated neuroinflammation. We found that pretreatment of ABBV-744 concentration-dependently inhibited the expression of LPS-induced inflammatory mediators/enzymes including NO, TNF-α, IL-1β, IL-6, iNOS, and COX-2 in BV-2 microglial cells. These effects were validated in LPS-treated primary microglial cells. Furthermore, we observed that administration of ABBV-744 significantly alleviated LPS-induced activation of microglia and transcriptional levels of pro-inflammatory factors TNF-α and IL-1β in mouse hippocampus and cortex. RNA-Sequencing (RNA-seq) analysis revealed that ABBV-744 induced 508 differentially expressed genes (DEGs) in LPS-stimulated BV-2 cells, and gene enrichment and gene expression network analysis verified its regulation on activated microglial genes and inflammatory pathways. We demonstrated that pretreatment of ABBV-744 significantly reduced the expression levels of basic leucine zipper ATF-like transcription factor 2 (BATF2) and interferon regulatory factor 4 (IRF4), and suppressed JAK-STAT signaling pathway in LPS-stimulated BV-2 cells and mice, suggesting that the anti-neuroinflammatory effect of ABBV-744 might be associated with regulation of BATF2-IRF4-STAT1/3/5 pathway, which was confirmed by gene knockdown experiments. This study demonstrates the effect of a BD2 high selective BET inhibitor, ABBV-744, against microglial inflammation, and reveals a BATF2-IRF4-STAT1/3/5 pathway in regulation of microglial inflammation, which might provide new clues for discovery of effective therapeutic strategy against neuroinflammation.

Magnesium lithospermate B enhances the potential of human-induced pluripotent stem cell-derived cardiomyocytes for myocardial repair

BACKGROUND

We previously reported that activation of the cell cycle in human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) enhances their remuscularization capacity after human cardiac muscle patch transplantation in infarcted mouse hearts. Herein, we sought to identify the effect of magnesium lithospermate B (MLB) on hiPSC-CMs during myocardial repair using a myocardial infarction (MI) mouse model.

METHODS

In C57BL/6 mice, MI was surgically induced by ligating the left anterior descending coronary artery. The mice were randomly divided into five groups (n = 10 per group); a MI group (treated with phosphate-buffered saline only), a hiPSC-CMs group, a MLB group, a hiPSC-CMs + MLB group, and a Sham operation group. Cardiac function and MLB therapeutic efficacy were evaluated by echocardiography and histochemical staining 4 weeks after surgery. To identify the associated mechanism, nuclear factor (NF)-κB p65 and intercellular cell adhesion molecule-1 (ICAM1) signals, cell adhesion ability, generation of reactive oxygen species, and rates of apoptosis were detected in human umbilical vein endothelial cells (HUVECs) and hiPSC-CMs.

RESULTS

After 4 weeks of transplantation, the number of cells that engrafted in the hiPSC-CMs + MLB group was about five times higher than those in the hiPSC-CMs group. Additionally, MLB treatment significantly reduced tohoku hospital pediatrics-1 (THP-1) cell adhesion, ICAM1 expression, NF-κB nuclear translocation, reactive oxygen species production, NF-κB p65 phosphorylation, and cell apoptosis in HUVECs cultured under hypoxia. Similarly, treatment with MLB significantly inhibited the apoptosis of hiPSC-CMs via enhancing signal transducer and activator of transcription 3 (STAT3) phosphorylation and B-cell lymphoma-2 (BCL2) expression, promoting STAT3 nuclear translocation, and downregulating BCL2-Associated X, dual specificity phosphatase 2 (DUSP2), and cleaved-caspase-3 expression under hypoxia. Furthermore, MLB significantly suppressed the production of malondialdehyde and lactate dehydrogenase and the reduction in glutathione content induced by hypoxia in both HUVECs and hiPSC-CMs in vitro.

CONCLUSIONS

MLB significantly enhanced the potential of hiPSC-CMs in repairing injured myocardium by improving endothelial cell function via the NF-κB/ICAM1 pathway and inhibiting hiPSC-CMs apoptosis via the DUSP2/STAT3 pathway.

DUSP2 affects bladder cancer prognosis by down-regulating MEK/ERK and P38 MAPK signaling pathways through PTPN7

BACKGROUND

As one of the leading causes of cancer death worldwide, bladder cancer (BCa) ranks 12th in incidence rate. Dual Specific Phosphatase 2 (DUSP2) is a member of the bispecific protein phosphatase subfamily. DUSP2 is closely related to the prognosis of cancer, but the role of DUSP2 in bladder cancer is still unclear. This study aims to explore how DUSP2 affects the prognosis of bladder cancer and clarify the important mechanism in bladder cancer.

METHODS

Bioinformatics and experiments have detected the anti-tumor effect of DUSP2. Construct a DUSP2 overexpression cell model, and then use protein blotting experiments to verify the efficiency of transfection. The effects of DUSP2 on proliferation, metastasis, apoptosis, epithelial mesenchymal transition (EMT) and immune invasion of bladder cancer cells were detected in vitro or in vivo. In addition, the mechanism of DUSP2 regulating MEK/ERK through PTPN7 pathway and P38 MAPK inhibiting the progression of bladder cancer was also discussed.

RESULTS

The expression of DUSP2 was down regulated in bladder cancer samples and cell lines. The overexpression of DUSP2 inhibits the proliferation, metastasis and immune microenvironment of bladder cancer cells. In addition, we confirmed that DUSP2 regulates MEK/ERK and P38 MAPK through PTPN7 pathway to inhibit the progression of bladder cancer.

CONCLUSION

DUSP2 inhibits the progression of bladder cancer by regulating PTPN7. These results suggest that DUSP2/PTPN7/MEK/ERK pathway may become a new therapeutic target for bladder cancer.

Advances in the study of macrophage polarization in inflammatory immune skin diseases

When exposed to various microenvironmental stimuli, macrophages are highly plastic and primarily polarized into the pro-inflammatory M1-type and the anti-inflammatory M2-type, both of which perform almost entirely opposing functions. Due to this characteristic, macrophages perform different functions at different stages of immunity and inflammation. Inflammatory immune skin diseases usually show an imbalance in the M1/M2 macrophage ratio, and altering the macrophage polarization phenotype can either make the symptoms worse or better. Therefore, this review presents the mechanisms of macrophage polarization, inflammation-related signaling pathways (JAK/STAT, NF-κB, and PI3K/Akt), and the role of both in inflammatory immune skin diseases (psoriasis, AD, SLE, BD, etc.) to provide new directions for basic and clinical research of related diseases.

ASCT2-mediated glutamine uptake promotes Th1 differentiation via ROS-EGR1-PAC1 pathway in oral lichen planus

Oral lichen planus (OLP) is a T cell-mediated autoimmune disease of oral mucosa concerning with the redox imbalance. Although glutamine uptake mediated by alanine-serine-cysteine transporter 2 (ASCT2) is critical to T cell differentiation, the exact mechanism remains ambiguous. Here, we elucidate a novel regulatory mechanism of ASCT2-mediated uptake in the differentiation and proliferation of T cells through maintaining redox balance in OLP. The results of immunohistochemistry (IHC) showed that both ASCT2 and glutaminase (GLS) were obviously upregulated compared to controls in OLP. Moreover, correlation analyses indicated that ASCT2 expression was significantly related to GLS level. Interestingly, the upregulation of glutamine metabolism in epithelial layer was consistent with that in lamina propria. Functional assays in vitro revealed the positive association between glutamine metabolism and lymphocytes infiltration. Additionally, multiplex immunohistochemistry (mIHC) uncovered a stronger colocalization among ASCT2 and CD4 and IFN-γ, which was further demonstrated by human Th1 differentiation assay in vitro. Mechanistically, targeting glutamine uptake through interference with ASCT2 using L-γ-Glutamyl-p-nitroanilide (GPNA) decreased the glutamine uptake of T cells and leaded to the accumulation of intracellular reactive oxygen species (ROS), which promoted dual specificity phosphatase 2 (DUSP2/PAC1) expression through activation of early growth response 1 (EGR1) to induce dephosphorylation of signal transducer and activator of transcription 3 (STAT3) and inhibit Th1 differentiation in turn. These results demonstrated that glutamine uptake mediated by ASCT2 induced Th1 differentiation by ROS-EGR1-PAC1 pathway, and restoring the redox dynamic balance through targeting ASCT2 may be a potential treatment for T cell-mediated autoimmune diseases.

Genome-wide analysis of long noncoding RNA profiles in pseudorabies-virus-infected PK15 cells

Recently, an increasing number of studies have shown that long noncoding RNAs (lncRNAs) are involved in host metabolism after infection with pseudorabies virus (PRV). In our study, via RNA sequencing analysis, a total of 418 mRNAs, 137 annotated lncRNAs, and 312 new lncRNAs were found to be differentially expressed. These lncRNAs were closely associated with metabolic regulation and immunity-related signalling pathways, including the T-cell receptor signalling pathway, chemokine signalling pathway, mitogen-activated protein kinase (MAPK) signalling pathway, TNF signalling pathway, Ras signalling pathway, calcium signalling pathway, and phosphatidylinositol signalling system. Real-time PCR indicated that several mRNAs and lncRNAs involved in the regulation of the immune effector process, T-cell receptor signalling pathway, TNF signalling pathway, MAPK signalling pathway, and chemokine signalling pathways were significantly expressed. These mRNAs and lncRNAs might play a role in PRV infection.

Immune response modulation in inflammatory bowel diseases by Helicobacter pylori infection

Many studies point to an association between Helicobacter pylori (H. pylori) infection and inflammatory bowel diseases (IBD). Although controversial, this association indicates that the presence of the bacterium somehow affects the course of IBD. It appears that H. pylori infection influences IBD through changes in the diversity of the gut microbiota, and hence in local chemical characteristics, and alteration in the pattern of gut immune response. The gut immune response appears to be modulated by H. pylori infection towards a less aggressive inflammatory response and the establishment of a targeted response to tissue repair. Therefore, a T helper 2 (Th2)/macrophage M2 response is stimulated, while the Th1/macrophage M1 response is suppressed. The immunomodulation appears to be associated with intrinsic factors of the bacteria, such as virulence factors - such oncogenic protein cytotoxin-associated antigen A, proteins such H. pylori neutrophil-activating protein, but also with microenvironmental changes that favor permanence of H. pylori in the stomach. These changes include the increase of gastric mucosal pH by urease activity, and suppression of the stomach immune response promoted by evasion mechanisms of the bacterium. Furthermore, there is a causal relationship between H. pylori infection and components of the innate immunity such as the NLR family pyrin domain containing 3 inflammasome that directs IBD toward a better prognosis.

BATF2 promotes HSC myeloid differentiation by amplifying IFN response mediators during chronic infection

Basic leucine zipper ATF-like transcription factor 2 (BATF2), an interferon-activated immune response regulator, is a key factor responsible for myeloid differentiation and depletion of HSC during chronic infection. To delineate the mechanism of BATF2 function in HSCs, we assessed Batf2 KO mice during chronic infection and found that they produced less pro-inflammatory cytokines, less immune cell recruitment to the spleen, and impaired myeloid differentiation with better preservation of HSC capacity compared to WT. Co-IP analysis revealed that BATF2 forms a complex with JUN to amplify pro-inflammatory signaling pathways including CCL5 during infection. Blockade of CCL5 receptors phenocopied Batf2 KO differentiation defects, whereas treatment with recombinant CCL5 was sufficient to rescue IFNγ-induced myeloid differentiation and recruit more immune cells to the spleen in Batf2 KO mice. By revealing the mechanism of BATF2-induced myeloid differentiation of HSCs, these studies elucidate potential therapeutic strategies to boost immunity while preserving HSC function during chronic infection.

Advances in the role of STAT3 in macrophage polarization

The physiological processes of cell growth, proliferation, differentiation, and apoptosis are closely related to STAT3, and it has been demonstrated that aberrant STAT3 expression has an impact on the onset and progression of a number of inflammatory immunological disorders, fibrotic diseases, and malignancies. In order to produce the necessary biological effects, macrophages (M0) can be polarized into pro-inflammatory (M1) and anti-inflammatory (M2) types in response to various microenvironmental stimuli. STAT3 signaling is involved in macrophage polarization, and the research of the effect of STAT3 on macrophage polarization has gained attention in recent years. In order to provide references for the treatment and investigation of disorders related to macrophage polarization, this review compiles the pertinent signaling pathways associated with STAT3 and macrophage polarization from many fundamental studies.

DUSP2-mediated inhibition of tubular epithelial cell pyroptosis confers nephroprotection in acute kidney injury

Rationale: Acute kidney injury (AKI) is pathologically characterized by renal tubular epithelial cell (RTEC) death and interstitial inflammation, while their pathogenesis remains incompletely understood. Dual-specificity phosphatase 2 (DUSP2) recently emerges as a crucial regulator of cell death and inflammation in a wide range of diseases, but its roles in renal pathophysiology are largely unknown. Methods: The expression of DUSP2 in the kidney was characterized by histological analysis in renal tissues from patients and mice with AKI. The role and mechanism of DUSP2-mediated inhibition of tubular epithelial cell pyroptosis in AKI were evaluated both in vivo and in vitro, and confirmed in RTEC-specific deletion of DUSP2 mice. Results: Here, we show that DUSP2 is enriched in RTECs in the renal tissue of both human and mouse and mainly positions in the nucleus. Further, we reveal that loss-of-DUSP2 in RTECs not only is a common feature of human and murine AKI but also positively contributes to AKI pathogenesis. Especially, RTEC-specific deletion of DUSP2 sensitizes mice to AKI by promoting RTEC pyroptosis and the resultant interstitial inflammation. Mechanistic studies show that gasdermin D (GSDMD), which mediates RTEC pyroptosis, is identified as a transcriptional target of activated STAT1 during AKI, whereas DUSP2 as a nuclear phosphatase deactivates STAT1 to restrict GSDMD-mediated RTEC pyroptosis. Importantly, DUSP2 overexpression in RTECs via adeno-associated virus-mediated gene transfer significantly ameliorates AKI. Conclusion: Our findings demonstrate a hitherto unrecognized role of DUSP2-STAT1 axis in regulating RTEC pyroptosis in AKI, highlighting that DUSP2-STAT1 axis is an attractive therapeutic target for AKI.

Bone marrow mesenchymal stem cells-derived exosomes suppress miRNA-5189-3p to increase fibroblast-like synoviocyte apoptosis via the BATF2/JAK2/STAT3 signaling pathway

Ankylosing spondylitis (AS) is characterized by inflammation of the sacroiliac joint and the attachment point of the spine. Herein, we aimed to investigate the effect of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes on apoptosis of fibroblast-like synoviocytes (FLSs) and explored its molecular mechanism. Exosomes were isolated from BMSCs and verified by transmission electron microscope and nanoparticle tracking analysis. FLSs were isolated and co-incubated with BMSC exosomes. Cell apoptosis was assessed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling analysis and flow cytometry. The results showed that BMSC exosomes increased apoptosis of FLSs. MiR-5189-3p was downregulated, while basic leucine zipper transcription factor ATF-like 2 (BATF2) was upregulated in FLSs by treatment of BMSC exosomes. As a direct target of miR-5189-3p, BATF2 inactivates the JAK2/STAT3 pathway. MiR-5189-3p suppressed apoptosis of FLSs and BATF2 exerted an opposite effect. In conclusion, BMSCs-derived exosomes suppress miR-5189-3p to facilitate the apoptosis of FLSs via the BATF2/JAK2/STAT3 signaling pathway, which facilitates the understanding of the therapeutic effect of BMSCs on AS and the underlying molecular mechanism.

Phosphoproteomics of Mycobacterium-host interaction and inspirations for novel measures against tuberculosis

Tuberculosis caused by Mycobacterium tuberculosis (Mtb) remains a tremendous global public health concern. Deciphering the biology of the pathogen and its interaction with host can inspire new measures against tuberculosis. Phosphorylation plays versatile and important role in the pathogen and host physiology, such as virulence, signaling and immune response. Proteome-wide phosphorylation of Mtb and its infected host cells, namely phosphoproteome, can inform the post-translational modification of the interaction network between the pathogen and the host, key targets for novel antibiotics. We summarized the phosphoproteome of Mtb, as well as the host, focusing on potential application for new measures against tuberculosis.

A mechanism of cooling hot tumors: Lactate attenuates inflammation in dendritic cells

Turning non-inflamed (cold) tumors into inflamed (hot) tumors is important for maximizing the effect of immune checkpoint inhibitors (ICIs) against malignancies. We showed that lactate, a product of the Warburg effect, inhibited the efficacy of ICIs and suppressed IL-12 p40 expression in dendritic cells (DCs) through reducing NF-κB p65, p50, and c-Rel DNA-binding activity to the IL-12 p40 promoter. Additionally, lactate promoted the expression of early growth response protein 1 (EGR1), whose expression was increased in human invasive melanoma compared with non-invasive melanoma. We also found that EGR1 interacts with serum response factor (SRF) and represses the expression of CD80 in DCs. These findings suggest that lactate and its induced EGR1 are key factors that turn hot tumors into cold tumors and may represent targets in cancer treatment with ICIs.

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Lactate suppressed IL-12 p40 expression in dendritic cells

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Lactate promoted the expression of early growth response protein 1 (EGR1)

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EGR1 interacts with serum response factor (SRF) and represses the expression of CD80

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Lactate and EGR1 switch inflamed (hot) tumors to non-inflamed (cold) tumors

Promotion Effect of EGCG on the Raised Expression of IL-23 through the Signaling of STAT3-BATF2-c-JUN/ATF2

Tea polyphenol of epigallocatechin-3-gallate (EGCG) has been verified to possess multiple biological activities. Interleukin-23 (IL-23) is a heterodimeric cytokine consisting of two subunits of IL-23p19 and IL-12p40, with the functionality in regulating the production of cytokines under physiological or pathological conditions. By serendipity, the raised expression of IL-23 was observed after treating cells with EGCG, whereas the detailed mechanism remains poorly understood. This study was proposed to investigate the signaling related to EGCG-induced IL-23. The raised expression of IL-23 was confirmed primarily by intraperitoneally injecting with different concentrations of EGCG (0, 20, 50, 80 mg/kg) into BALB/c mice, and the raised expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Results from enzyme-linked immunosorbent assay (ELISA) revealed the increase of IL-23 in serum from 116.09 to 153.90 pg/mL after treating with EGCG. The same results were also observed in RAW264.7 and peritoneal macrophages after treating with EGCG (0, 1, 5, 10, 25 μM) with the increased tendency of IL-23 in cultural medium (7.98 to 25.38 pg/mL for RAW264.7; 3.64 to 260.93 pg/mL for peritoneal macrophages). After preliminary exploration of the signaling related to the increased IL-23, the classical signaling pathways and key transcription factors, such as nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase (MAPK) signaling pathways, and interferon regulatory factor 5 (IRF5), were demonstrated with no relevant contribution. A further study revealed the involvement of the key transcription factor of BATF2, which could antagonistically modulate the transcription and translation of IL-23. The signaling of STAT3-BATF2-c-JUN/ATF2-IL-23 has been further verified in RAW264.7 macrophages using the STAT3 inhibitor of AG490 and the activator of Colivelin TFA. The results indicated that EGCG inhibits the phosphorylation of STAT3 to facilitate the decreased level of BATF2, which contributed to the increased level of IL-23 by the enhancing heterodimerization of c-JUN and ATF2.

Comprehensive Transcriptomic Analysis Identifies Novel Antiviral Factors Against Influenza A Virus Infection

Influenza A virus (IAV) has a higher genetic variation, leading to the poor efficiency of traditional vaccine and antiviral strategies targeting viral proteins. Therefore, developing broad-spectrum antiviral treatments is particularly important. Host responses to IAV infection provide a promising approach to identify antiviral factors involved in virus infection as potential molecular drug targets. In this study, in order to better illustrate the molecular mechanism of host responses to IAV and develop broad-spectrum antiviral drugs, we systematically analyzed mRNA expression profiles of host genes in a variety of human cells, including transformed and primary epithelial cells infected with different subtypes of IAV by mining 35 microarray datasets from the GEO database. The transcriptomic results showed that IAV infection resulted in the difference in expression of amounts of host genes in all cell types, especially those genes participating in immune defense and antiviral response. In addition, following the criteria of P<0.05 and |logFC|≥1.5, we found that some difference expression genes were overlapped in different cell types under IAV infection via integrative gene network analysis. IFI6, IFIT2, ISG15, HERC5, RSAD2, GBP1, IFIT3, IFITM1, LAMP3, USP18, and CXCL10 might act as key antiviral factors in alveolar basal epithelial cells against IAV infection, while BATF2, CXCL10, IFI44L, IL6, and OAS2 played important roles in airway epithelial cells in response to different subtypes of IAV infection. Additionally, we also revealed that some overlaps (BATF2, IFI44L, IFI44, HERC5, CXCL10, OAS2, IFIT3, USP18, OAS1, IFIT2) were commonly upregulated in human primary epithelial cells infected with high or low pathogenicity IAV. Moreover, there were similar defense responses activated by IAV infection, including the interferon-regulated signaling pathway in different phagocyte types, although the differentially expressed genes in different phagocyte types showed a great difference. Taken together, our findings will help better understand the fundamental patterns of molecular responses induced by highly or lowly pathogenic IAV, and the overlapped genes upregulated by IAV in different cell types may act as early detection markers or broad-spectrum antiviral targets.

EIF2AK2 selectively regulates the gene transcription in immune response and histones associated with systemic lupus erythematosus

PKR, also known as EIF2AK2, is an IFN-stimulated gene (ISG) and shows a higher expression in probands with systemic lupus erythematosus (SLE), which is likely responsible for the impaired translational and proliferative responses to mitogens in T cells from SLE patients. In this study, we overexpressed EIF2AK2 in HeLa cells to study EIF2AK2-regulated genes using RNA-seq technology, followed by bioinformatic analysis of target genes of EIF2AK2-regulated transcriptional factors (TFs). Overexpression of EIF2AK2 promotes HeLa cell apoptosis. EIF2AK2 selectively represses the transcription of histone protein genes associated with SLE, immune response genes and TF genes, which was validated by RT-qPCR experiments. Analysis of motifs overrepresented in the promoter regions of EIF2AK2-regulated genes revealed eighteen EIF2AK2-regulated TFs involved in establishing the EIF2AK2 network. Eight out of these predicted EIF2AK2-regulated TFs were further verified by RT-qPCR selectively in both HeLa and Jurkat cells, and most such as HEY2, TFEC, BATF2, GATA3 and ATF3 and FOXO6 are known to regulate immune response. Our results suggest that the dsRNA-dependent kinase EIF2AK2 selectively regulates the transcription of immune response and SLE-associated histone protein genes, and such a selectivity is likely to be operated by EIF2AK2-targeted TFs. The EIF2AK2-TFs axis potentially offers new therapeutic targets for counteracting immunological disease in the future.

Dual-Specificity Phosphatases in Immunity and Infection: An Update

Kinase activation and phosphorylation cascades are key to initiate immune cell activation in response to recognition of antigen and sensing of microbial danger. However, for balanced and controlled immune responses, the intensity and duration of phospho-signaling has to be regulated. The dual-specificity phosphatase (DUSP) gene family has many members that are differentially expressed in resting and activated immune cells. Here, we review the progress made in the field of DUSP gene function in regulation of the immune system during the last decade. Studies in knockout mice have confirmed the essential functions of several DUSP-MAPK phosphatases (DUSP-MKP) in controlling inflammatory and anti-microbial immune responses and support the concept that individual DUSP-MKP shape and determine the outcome of innate immune responses due to context-dependent expression and selective inhibition of different mitogen-activated protein kinases (MAPK). In addition to the canonical DUSP-MKP, several small-size atypical DUSP proteins regulate immune cells and are therefore also reviewed here. Unexpected and complex findings in DUSP knockout mice pose new questions regarding cell type-specific and redundant functions. Another emerging question concerns the interaction of DUSP-MKP with non-MAPK binding partners and substrate proteins. Finally, the pharmacological targeting of DUSPs is desirable to modulate immune and inflammatory responses.