Ifit1 Protects Against Lipopolysaccharide and D-galactosamine-Induced Fatal Hepatitis by Inhibiting Activation of the JNK Pathway

Senescent cells promote breast cancer cells motility by secreting GM-CSF and bFGF that activate the JNK signaling pathway

BACKGROUND

Cellular senescence can be induced in mammalian tissues by multiple stimuli, including aging, oncogene activation and loss of tumor suppressor genes, and various types of stresses. While senescence is a tumor suppressing mechanism when induced within premalignant or malignant tumor cells, senescent cells can promote cancer development through increased secretion of growth factors, cytokines, chemokines, extracellular matrix, and degradative enzymes, collectively known as senescence-associated secretory phenotype (SASP). Previous studies indicated that senescent cells, through SASP factors, stimulate tumor cell invasion that is a critical step in cancer cell metastasis.

METHODS

In the current study, we investigated the effect of senescent cells on the motility of breast cancer cells, which is another key step in cancer cell metastasis. We analyzed the motility of breast cancer cells co-cultured with senescent cells in vitro and metastasis of the breast cancer cells co-injected with senescent cells in orthotopic xenograft models. We also delineated the signaling pathway mediating the effect of senescent cells on cancer cell motility.

RESULTS

Our results indicate that senescent cells stimulated the migration of breast cancer cells through secretion of GM-CSF and bFGF, which in turn induced activation of the JNK pathway in cancer cells. More importantly, senescent cells promoted breast cancer metastasis, with a minimum effect on the primary tumor growth, in orthotopic xenograft mouse models.

CONCLUSIONS

These results have revealed an additional mechanism by which senescent cells promote tumor cell metastasis and tumor progression, and will potentially lead to identification of novel targets for cancer therapies that suppress metastasis, the major cause of cancer mortality.

The Role of Interferon-Induced Proteins with Tetratricopeptide Repeats 1 and 2 in Sepsis-Induced Acute Liver Injury

Background

Sepsis refers to a life-threatening organ dysfunction which can be resulted from the infection-induced dysregulated host response. A large number of inflammatory cytokines are released to act on the liver, making the liver one of the common target organs for the development of multiple organ dysfunction syndrome (MODS) in patients with sepsis. Sepsis-induced acute liver injury (SALI) can aggravate systemic disease. As a result, it is of great clinical significance to comprehend the molecular biological mechanism of SALI and to identify the markers for evaluating SALI. Interferon-induced proteins with tetratricopeptide repeats 1 and 2 (IFIT1, IFIT2) have been recognized as the anti-inflammatory factors that are widely expressed in various organs. The present study was aimed at clarifying the roles of IFIT1 and IFIT2 in the development of SALI.

Methods

A two-sample Mendelian randomization (MR) analysis was employed. Summary statistics datas were obtained from GWAS for inflammatory factors [tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6)], IFIT2, and sepsis as well as liver injury. Independent SNPs were selected as instrumental variables (IVs). Inverse variance weighted (IVW) in the MR analysis was adopted as the primary method for estimating the causal associations of inflammatory factors and IFIT2 with two diseases, and the associations of inflammatory factors with IFIT2. Additionally, weighted median method, MR-Egger and sensitivity analyses were applied in assessing the robustness of the results and ensure the result reliability. Subsequently, 119 healthy volunteers, 116 patients with sepsis and 116 SALI patients were recruited. The ELISA method was employed to quantify the expression levels of TNF-α, IL-1β, and IL-6. Additionally, qRT-PCR was conducted to measure the expression of IFIT1 and IFIT2. Furthermore, the correlations of IFIT1 and IFIT2 with inflammatory factors, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were explored.

Results

As shown by the MR analysis, the genetically predisposed sepsis was significantly associated with the risk of IL-1β, with an odds ratio (OR) of 1.069 (95% confidence interval (CI), 1.015-1.127, p = 0.0119), and negatively associated with the risk of IL-6, with an OR of 0.880 (95% CI: 0.792-0.979, p= 0.0184). Meanwhile, there were positive causal effects of IL-6 (OR = 1.269, 95% CI: 1.032-1.561, p= 0.0238), IL-1β (OR = 1.106, 95% CI: 1.010-1.211, p = 0.0299) and IFIT2 (OR = 1.191, 95% CI: 1.045-1.359, p = 0.0090) on liver injury. Additionally, there was a positive causal effect of IFIT2 (OR = 1.164, 95% CI: 1.035-1.309, p= 0.0110) on IL-1β. Upon sensitivity analyses, there was weak evidence of such effects, indicating that the findings of this study were robust and reliable. Our results revealed the elevated levels of TNF-α, IL-1β, and IL-6 in the blood samples of sepsis and SALI patients (p < 0.0001). Conversely, IFIT1 and IFIT2 demonstrated the significantly decreased levels in peripheral blood mononuclear cells (PBMCs) of SALI patients (p < 0.0001). Furthermore, the expression levels of IFIT1 and IFIT2 were both negatively correlated with ALT activity (r = -0.3426, p = 0.0002; r = -0.3069, p = 0.0008) and AST activity (r = -0.2483, p = 0.0072; r = -0.3261, p = 0.0004), respectively. Moreover, the expression of IFIT1 and IFIT2 was both negatively related to the levels of TNF-α (r = -0.5027, p < 0.0001; r = -0.4218, p < 0.0001), IL-1β (r = -0.3349, p = 0.0002; r = -0.4070, p < 0.0001) and IL-6 (r = -0.2734, p = 0.0030; r = -0.3536, p < 0.0001), respectively.

Conclusion

IFIT1 and IFIT2 can serve as the diagnostic markers for sepsis-related liver injury, and IFIT1 and IFIT2 may participate in the pathological process of sepsis-related liver injury by regulating inflammation and liver function.

Superoxide dismutase ameliorates oxidative stress and regulates liver transcriptomics to provide therapeutic benefits in hepatic inflammation

Background

Oxidative stress refers to the imbalance between oxidants and antioxidants in organisms and often induces hepatic inflammation. Supplementing exogenous superoxide dismutase is an effective way to alleviate oxidative stress; however, the effects and mechanisms by which superoxide dismutase alleviates hepatic inflammation remain unclear.

Methods

This study established a Kunming mouse model to verify and investigate the oxidative stress and hepatic inflammation-alleviating effects of the superoxide dismutase oral supplement that was prepared by our research group in a previous study.

Results

The superoxide dismutase product significantly restored the body weight and liver alanine transaminase, aspartate aminotransferase, superoxide dismutase, catalase, glutathione, and glutathione peroxidase levels of oxidative stress induced mice. Moreover, exogenous superoxide dismutase significantly inhibited interleukin 1β and interleukin 6 mRNA expression in the livers of mice with hepatic inflammation. Transcriptomic analysis indicated that superoxide dismutase had a significant inhibitory effect on Endog expression, alleviating oxidative stress damage, and mediating liver cell apoptosis by regulating the expression of Rab5if, Hnrnpab, and Ifit1.

Conclusion

Our research verified the oxidative stress remediation effects of superoxide dismutase and its therapeutic role against hepatic inflammation. This study can lay a foundation for investigating the mechanism by which superoxide dismutase alleviates hepatic disease.

Whole exome sequencing reveals novel variants associated with diminished ovarian reserve in young women

Background: Diminished ovarian reserve is one of the most important causes of female infertility. In the etiology study of DOR, besides age, it is known that chromosomal abnormality, radiotherapy, chemotherapy and ovarian surgery can result in DOR. For young women without obvious risk factors, gene mutation should be considered as a possible cause. However, the specific molecular mechanism of DOR has not been fully elucidated.

Methods: In order to explore the pathogenic variants related to DOR, twenty young women under 35 years old affected by DOR without definite factors damaging ovarian reserve were recruited as the research subjects, and five women with normal ovarian reserve were recruited as the control group. Whole exome sequencing was applied as the genomics research tool.

Results: As a result, we obtained a set of mutated genes that may be related to DOR, where the missense variant on GPR84 was selected for further study. It is found that GPR84Y370H variant promotes the expression of proinflammatory cytokines (TNF-α, IL12B, IL-1β) and chemokines (CCL2, CCL5), as well as the activation of NF-κB signaling pathway.

Conclusion: In conclusion, GPR84Y370H variant was identified though analysis for WES results of 20 DOR patients. The deleterious variant of GPR84 could be the potential molecular mechanism of non-age-related pathological DOR through its role in promoting inflammation. The findings of this study can be used as a preliminary research basis for the development of early molecular diagnosis and treatment target selection of DOR.

Overexpression of IFIT1 protects against LPS-induced acute lung injury via regulating CCL5-p65NF-κB signaling

Acute lung injury (ALI) is featured by intensive inflammatory responses causing significant morbidity and mortality. Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), induced by interferon (IFN), has been discovered to modulate viral infection and cell apoptosis and inhibit the production of pro-inflammatory cytokines. However, it's role and mechanism in ALI remain unclear and need to be explored furtherly. Here, we discovered that IFIT1 decreased the expression of TNF-α, IL-1β and IL-6 in mouse-derived macrophage cells (MH-S) and alleviated apoptosis of murine lung epithelial cells (MLE-12) induced by MH-S cell supernatant, contributing to anti-inflammatory and antiapoptotic effects in vitro and in vivo. Moreover, RNA sequencing analysis (RNA-seq) showed that inflammatory chemokine CC motif chemokine ligand 5 (CCL5) partially eliminated the protective effects of IFIT1 and promoted the expression of inflammatory cytokines TNF-α, IL-1β and IL-6 by CCL5-p65NF-κB signaling pathway. This study demonstrated that IFIT1 attenuated ALI-associated inflammation and cell apoptosis by regulating the CCL5-p65NF-κB signaling pathway. These findings are of great significance for the treatment of lung injury.

Genome-wide CRISPR knockout screening identified G protein pathway suppressor 2 as a novel tumor suppressor for uveal melanoma metastasis

PURPOSE

Uveal melanoma (UM) is the most common intraocular malignant tumor in adults. Due to the lack of effective treatments for metastatic UM, the survival of UM has not changed over the past 3 decades. Therefore, it is important to identify essential genes regulating the metastasis of UM.

METHODS

In this study, a genome-wide CRISPR knockout screen in an orthotopic mouse model of UM was performed to identify the regulatory genes conferring the metastatic phenotype. Loss-of-function analyses were performed to explore the function of G protein pathway suppressor 2 (GPS2) in UM metastasis in vitro and in vivo. RNA sequencing was performed to investigate the molecular mechanism underlying the function of GPS2 as a tumor suppressor in UM.

RESULTS

Among the highest-ranking genes, we found several validated tumor suppressors, such as SHPRH, GPS2, PRPH2, and hsa-mir-1229; GPS2 was chosen as the candidate gene for further studies. GPS2 was lower expressed in the tumor tissues of UM patients. Furthermore, knocking-down GPS2 promoted the proliferation and metastatic abilities of UM cells both in vivo and in vitro. Finally, analysis of the transcriptome data revealed that silencing GPS2 upregulates oncogenic signaling pathways MAPK and PI3K-Akt, and in the meantime downregulates tumor suppressor signaling pathway Slit/Robo in UM cells.

CONCLUSION

Altogether, our study proved that the GPS2 gene functions as a tumor suppressor and might be a novel potential therapeutic target for UM treatment.

A systematic CRISPR screen reveals an IL-20/IL20RA-mediated immune crosstalk to prevent the ovarian cancer metastasis

Transcoelomic spread of cancer cells across the peritoneal cavity occurs in most initially diagnosed ovarian cancer (OC) patients and accounts for most cancer-related death. However, how OC cells interact with peritoneal stromal cells to evade the immune surveillance remains largely unexplored. Here, through an in vivo genome-wide CRISPR/Cas9 screen, we identified IL20RA, which decreased dramatically in OC patients during peritoneal metastasis, as a key factor preventing the transcoelomic metastasis of OC. Reconstitution of IL20RA in highly metastatic OC cells greatly suppresses the transcoelomic metastasis. OC cells, when disseminate into the peritoneal cavity, greatly induce peritoneum mesothelial cells to express IL-20 and IL-24, which in turn activate the IL20RA downstream signaling in OC cells to produce mature IL-18, eventually resulting in the polarization of macrophages into the M1-like subtype to clear the cancer cells. Thus, we show an IL-20/IL20RA-mediated crosstalk between OC and mesothelial cells that supports a metastasis-repressing immune microenvironment.

A novel isoform of ATOH8 promotes the metastasis of breast cancer by regulating RhoC

Metastases are the main cause of cancer-related mortality in breast cancer. Although significant progress has been made in the field of tumor metastasis, the exact molecular mechanisms involved in tumor metastasis are still unclear. Here, we report that ATOH8-V1, a novel isoform of ATOH8, is highly expressed in breast cancer and is a negative prognostic indicator of survival for patients. Forced expression of ATOH8-V1 dramatically enhances, while silencing of ATOH8-V1 decreases the metastasis of breast cancer cell lines. Moreover, ATOH8-V1 directly binds to the RhoC promoter and stimulates the expression of RhoC, which in turn enhances the metastasis of breast cancer. Altogether, our data demonstrate that ATOH8-V1 is a novel pro-metastatic factor that enhances cancer metastasis, suggesting that ATOH8-V1 is a potential therapeutic target for treatment of metastatic cancers.

MxA suppresses TAK1-IKKα/β-NF-κB mediated inflammatory cytokine production to facilitate Mycobacterium tuberculosis infection

OBJECTIVES

Interferons (IFNs) play multifunctional roles in host defense against infectious diseases by inducing IFN-stimulated genes (ISGs). However, little is known about how ISGs regulate host immune response to Mycobacterium tuberculosis (Mtb) infection, the major cause of tuberculosis (TB).

METHODS

We thus profiled the potential effects and mechanisms of eight Mtb-induced ISGs on Mtb infection by RNA interference in human macrophages (Mφs) derived from peripheral blood monocytes (hMDMs) and THP-1 cell line derived Mφs (THP-1-Mφs).

RESULTS

MxA silencing significantly decreased intracellular Mtb infection in Mφs. Mechanistically, MxA silencing promoted inflammatory cytokines IL-1β, IL-6 and TNF-α production, and induced NF-κB p65 activation. Pharmacological inhibition of NF-κB p65 activation or gene silencing of NF-κB p65 blocked the increased production of IL-1β, IL-6 and TNF-α and restored Mtb infection by MxA silencing. Furthermore, pharmacological inhibition of TAK1 and IKKα/β blocked NF-κB p65 activation and subsequent production of pro-inflammatory cytokines by MxA silencing. Isoniazid (INH) treatment and MxA silencing could promote TAK1-IKKα/β-NF-κB signaling pathway activation and combat Mtb infection independently.

CONCLUSIONS

Our results reveal a novel role of MxA in regulating TAK1-IKKα/β-NF-κB signaling activation and production of antimicrobial inflammatory cytokines upon Mtb infection, providing a potential target for clinical treatment of TB.

WIP1 promotes cancer stem cell properties by inhibiting p38 MAPK in NSCLC

Cancer stem cells (CSCs) are a small population of stem cell-like cancer cells that can initiate tumors in vivo, and are the major source of cancer initiation, relapse, and drug resistance. We previously reported that the p38 MAPK, through its downstream effectors MK2 and HSP27, suppressed CSC properties by downregulating the expression of transcription factors that mediate stemness in non-small-cell lung cancer (NSCLC) cells, and that despite unaltered total expression of total p38 proteins, the levels of activated p38 were reduced in NSCLC tissues. However, the mechanism underlying the reduced levels of activated p38 in NSCLC is unknown. In this study, we identified WIP1, a p38 phosphatase frequently overexpressed in cancer, as a suppressor of p38 in a pathway that regulates CSC properties in NSCLC. Increased WIP1 expression correlated with reduced levels of activated p38, and with increased levels of a CSC marker in NSCLC tissues. Further investigation revealed that WIP1 promoted stemness-related protein expression and CSC properties by inhibiting p38 activity in NSCLC cells. WIP1 inhibitors are currently under development as anticancer drugs based on their ability to reactivate p53. We found that a WIP1 inhibitor suppressed stemness-related protein expression and CSC properties by activating p38 in NSCLC cells in vitro and in vivo. These studies have identified the WIP1–p38–MK2–HSP27 cascade as a novel signaling pathway that, when altered, promotes CSC properties in NSCLC development, and have defined novel mechanisms underlying the oncogenic activity of WIP1 and the anticancer efficacy of WIP1 inhibitors.

Dietary fish oil supplementation alters liver gene expressions to protect against LPS-induced liver injury in weanling piglets

Here, the potential mechanisms of the protective effects of fish oil against LPS-induced liver injury in a piglet model were investigated by using RNA sequencing. Twenty-four piglets were used in a 2 × 2 factorial design, and the main factors included diet (5% corn oil or 5% fish oil) and immunological challenge (LPS or saline, on d 19). All piglets were slaughtered at 4 h after challenge, and liver samples were collected. Fish oil improved liver morphology and reduced TNF-α, IL-1β and IL-6 productions after LPS challenge. RNA sequencing analysis showed fish oil had significant effect on the expressions of genes involved in immune response during LPS-induced inflammation. Selected gene expression changes were validated using quantitative RT-PCR. Fish oil reduced the expressions of pro-inflammatory genes IL1R1, IL1RAP, CEBPB and CRP, and increased that of anti-inflammatory genes IL-18BP, NFKBIA, IFIT1, IFIT2 and ATF3. Moreover, fish oil restored the expressions of some lipid metabolism-related genes, such as ACAA1, ACACA, ACADS and ACADM, which were only decreased in pigs fed a corn oil diet after LPS challenge. Our RNA sequencing reveals novel gene-nutrient interactions following fish oil supplementation and evoked inflammation, which add to the current understanding of the benefits of n-3 polyunsaturated fatty acids against liver injury.

E6-induced selective translation of WNT4 and JIP2 promotes the progression of cervical cancer via a noncanonical WNT signaling pathway

mRNA translation reprogramming occurs frequently in many pathologies, including cancer and viral infection. It remains largely unknown whether viral-induced alterations in mRNA translation contribute to carcinogenesis. Most cervical cancer is caused by high-risk human papillomavirus infection, resulting in the malignant transformation of normal epithelial cells mainly via viral E6 and E7 oncoproteins. Here, we utilized polysome profiling and deep RNA sequencing to systematically evaluate E6-regulated mRNA translation in HPV18-infected cervical cancer cells. We found that silencing E6 can cause over a two-fold change in the translation efficiency of ~653 mRNAs, most likely in an eIF4E- and eIF2α-independent manner. In addition, we identified that E6 can selectively upregulate the translation of WNT4, JIP1, and JIP2, resulting in the activation of the noncanonical WNT/PCP/JNK pathway to promote cell proliferation in vitro and tumor growth in vivo. Ectopic expression of WNT4/JIP2 can effectively rescue the decreased cell proliferation caused by E6 silencing, strongly suggesting that the WNT4/JIP2 pathway mediates the role of E6 in promoting cell proliferation. Thus, our results revealed a novel oncogenic mechanism of E6 via regulating the translation of mRNAs.

Interferon regulatory factors 3 and 7 have distinct roles in the pathogenesis of alphavirus encephalomyelitis

Interferon (IFN) regulatory factors (IRFs) are important determinants of the innate response to infection. We evaluated the role(s) of combined and individual IRF deficiencies in the outcome of infection of C57BL/6 mice with Sindbis virus, an alphavirus that infects neurons and causes encephalomyelitis. The brain and spinal cord levels of Irf7, but not Irf3 mRNAs, were increased after infection. IRF3/5/7-/- and IRF3/7-/- mice died within 3-4 days with uncontrolled virus replication, similar to IFNα receptor-deficient mice, while all wild-type (WT) mice recovered. IRF3-/- and IRF7-/- mice had brain levels of IFNα that were lower, but brain and spinal cord levels of IFNβ and IFN-stimulated gene mRNAs that were similar to or higher than WT mice without detectable serum IFN or increases in Ifna or Ifnb mRNAs in the lymph nodes, indicating that the differences in outcome were not due to deficiencies in the central nervous system (CNS) type I IFN response. IRF3-/- mice developed persistent neurological deficits and had more spinal cord inflammation and higher CNS levels of Il1b and Ifnγ mRNAs than WT mice, but all mice survived. IRF7-/- mice died 5-8 days after infection with rapidly progressive paralysis and differed from both WT and IRF3-/- mice in the induction of higher CNS levels of IFNβ, tumour necrosis factor (TNF) α and Cxcl13 mRNA, delayed virus clearance and more extensive cell death. Therefore, fatal disease in IRF7-/- mice is likely due to immune-mediated neurotoxicity associated with failure to regulate the production of inflammatory cytokines such as TNFα in the CNS.

Inactivation of p38 MAPK contributes to stem cell-like properties of non-small cell lung cancer

Cancer stem cells (CSCs) are recognized as the major source for cancer initiation and recurrence. Yet, the mechanism by which the cancer stem cell properties are acquired and maintained in a cancer cell population is not well understood. In the current study, we observed that the level of active p38 MAPK is downregulated, while the level of the stemness marker SOX2 is upregulated in lung cancer tissues as compared to normal tissues. We further demonstrated that inactivation of p38 is a potential mechanism contributing to acquisition and maintenance of cancer stem cell properties in non-small cell lung cancer (NSCLC) cells. p38, in particular the p38γ and p38δ isoforms, suppresses the cancer stem cell properties and tumor initiating ability of NSCLC cells by promoting the ubiquitylation and degradation of stemness proteins such as SOX2, Oct4, Nanog, Klf4 and c-Myc, through MK2-mediated phosphorylation of Hsp27 that is an essential component of the proteasomal degradation machinery. In contrast, inactivation of p38 in lung cancer cells leads to upregulation of the stemness proteins, thus promoting the cancer stem cell properties of these cells. These findings have demonstrated a novel mechanism by which cancer stem cell properties are acquired and maintained in a cancer cell population, and have revealed a new function of the p38 pathway in suppressing cancer development. These studies have also identified a new pathway that can potentially serve as a target for cancer therapies aimed at eliminating CSCs.

Ulinastatin attenuates LPS-induced human endothelial cells oxidative damage through suppressing JNK/c-Jun signaling pathway

Lipopolysaccharide (LPS)-induced oxidative stress is a main feature observed in the sepsis by increasing endothelial oxidative damage. Many studies have demonstrated that Ulinastatin (UTI) can inhibit pro-inflammatory proteases, decrease inflammatory cytokine levels and suppress oxidative stress. However, the potential molecular mechanism underlying UTI which exerts its antioxidant effect is not well understood. In this study, we aimed to investigate the effects of UTI on the LPS-induced oxidative stress and the underlying mechanisms using human umbilical vein endothelial cells (HUVECs). After oxidative stress induced By LPS in HUVECs, the cell viability and reactive oxygen species (ROS) in cytoplasm were measured. In addition, superoxide dismutase (SOD) and malondialdehyde (MDA) were examined. We found that LPS resulted in a profound elevation of ROS production and MDA levels. The decrease in Cu/Zn-SOD protein and increased in Mn-SOD protein were observed in a time- and dose-dependent manner. These responses were suppressed by an addition of UTI. The increase in c-Jun N-terminal kinases (JNK) phosphorylation by LPS in HUVECs was markedly blocked by UTI or JNK inhibitor SP600125. Our results suggest that UTI exerts its anti-oxidant effects by decreasing overproduction of ROS induced by LPS via suppressing JNK/c-Jun phosphorylation. Therefore UTI may play a protective role in vascular endothelial injury induced by oxidative stress such as sepsis. This study may provide insight into a possible molecular mechanism by which Ulinastatin inhibits LPS-induced oxidative stress.