miR-155 regulates pro- and anti-inflammatory cytokine expression in human monocytes during chronic hepatitis C virus infection

Chitosan nanoparticles-based in vivo delivery of miR-155 modulates the Viral haemorrhagic septicaemia virus-induced antiviral immune responses in zebrafish (Danio rerio)

Viral haemorrhagic septicaemia virus (VHSV) is one of the highly pathogenic virus, which causes viral haemorrhagic septicaemia disease in both marine and freshwater fish. Micro RNA-155 (miRNA-155) is a multifunctional small non-coding RNA and it involves regulation of immune responses during viral infection. In this study, dre-miR-155 mimics were encapsulated into chitosan nanoparticles (CNPs). Resulted encapsulated product (miR-155-CNPs) was investigated for its immunomodulation role in zebrafish during experimentally challenged VHSV infection. Successful encapsulation of dre-miR-155 mimics into CNPs was confirmed through average nanoparticle (NPs) size (341.45 ± 10.00 nm), increased encapsulation efficiency percentage (98.80%), bound dre-miR-155 with chitosan, sustained release in vitro (up to 40%), and the integrity of RNA. Overexpressed miR-155 was observed in gills, muscle, and kidney tissues (5.42, 19.62, and 140.72-folds, respectively) after intraperitoneal delivery of miR-155-CNPs into zebrafish upon VHSV infection (miR-155-CNPs + VHSV). The miR-155-CNPs + VHSV infected fish had the highest cumulative survival (85%), which was associated with low viral copy numbers. The miR-155-overexpressing fish showed significantly decreased expression of ifnγ, irf2bpl, irf9, socs1a, il10, and caspase3, compared to that of the miR-155 inhibitor + VHSV infected fish group. In contrast, il1β, tnfα, il6, cd8a, and p53 expressions were upregulated in miR-155-overexpressed zebrafish compared to that of the control. The overall findings indicate the successful delivery of dre-miR-155 through miR-155-CNPs that enabled restriction of VHSV infection in zebrafish presumably by modulating immune gene expression.

MicroRNA-155, a double-blade sword regulator of innate tuberculosis immunity

Tuberculosis (TB) is a chronic, life-threatening disease caused by unusual facultative intracellular bacteria, Mycobacterium tuberculosis. This bacterium has unique resistance to many antimicrobial agents and has become a major global health concern due to emerging multidrug-resistant strains. Additionally, it has developed multiple schemes to exploit host immune signaling and establish long-term survival within host tissues. Thus, understanding the pathways that govern the crosstalk between the bacterium and the immune system could provide a new avenue for therapeutic interventions. MicroRNAs (miRs) are short, noncoding, and regulator RNA molecules that control the expression of cellular genes by targeting their mRNAs post-transcriptionally. MiR-155 is one of the most crucial miR in shaping the host immune defenses against M. tuberculosis. MiR-155 is remarkably downregulated in patients with clear clinical TB symptoms in comparison with latently infected patients and/or healthy individuals, thereby implicating its role in controlling M. tuberculosis infection. However, functional probing of miR-155 suggests dual effects in regulating the host's innate defenses in response to mycobacterial infection. This review provides comprehensive knowledge and future perspectives regarding complex signaling pathways that mediated miR-155 expression during M. tuberculosis infections. Moreover, miR-155-targeting signaling orchestrates inflammatory mediators' production, apoptosis, and autophagy.

Novel Tryptanthrin Derivatives with Selectivity as c-Jun N-Terminal Kinase (JNK) 3 Inhibitors

The c-Jun N-terminal kinase (JNK) family includes three proteins (JNK1-3) that regulate many physiological processes, including cell proliferation and differentiation, cell survival, and inflammation. Because of emerging data suggesting that JNK3 may play an important role in neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease, as well as cancer pathogenesis, we sought to identify JNK inhibitors with increased selectivity for JNK3. A panel of 26 novel tryptanthrin-6-oxime analogs was synthesized and evaluated for JNK1-3 binding (K_d) and inhibition of cellular inflammatory responses. Compounds 4d (8-methoxyindolo[2,1-b]quinazolin-6,12-dione oxime) and 4e (8-phenylindolo[2,1-b]quinazolin-6,12-dione oxime) had high selectivity for JNK3 versus JNK1 and JNK2 and inhibited lipopolysaccharide (LPS)-induced nuclear factor-κB/activating protein 1 (NF-κB/AP-1) transcriptional activity in THP-1Blue cells and interleukin-6 (IL-6) production by MonoMac-6 monocytic cells in the low micromolar range. Likewise, compounds 4d, 4e, and pan-JNK inhibitor 4h (9-methylindolo[2,1-b]quinazolin-6,12-dione oxime) decreased LPS-induced c-Jun phosphorylation in MonoMac-6 cells, directly confirming JNK inhibition. Molecular modeling suggested modes of binding interaction of these compounds in the JNK3 catalytic site that were in agreement with the experimental data on JNK3 binding. Our results demonstrate the potential for developing anti-inflammatory drugs based on these nitrogen-containing heterocyclic systems with selectivity for JNK3.

Roles of microRNAs in Hepatitis C Virus Replication and Pathogenesis

Hepatitis C virus (HCV) infection is associated with the development of chronic liver diseases, e.g., fibrosis, cirrhosis, even hepatocellular carcinoma, and/or extra-hepatic diseases such as diabetes. As an obligatory intracellular pathogen, HCV absolutely relies on host cells to propagate and is able to modulate host cellular factors in favor of its replication. Indeed, lots of cellular factors, including microRNAs (miRNAs), have been identified to be dysregulated during HCV infection. MiRNAs are small noncoding RNAs that regulate protein synthesis of their targeting mRNAs at the post-transcriptional level, usually by suppressing their target gene expression. The miRNAs dysregulated during HCV infection could directly or indirectly modulate HCV replication and/or induce liver diseases. Regulatory mechanisms of various miRNAs in HCV replication and pathogenesis have been characterized. Some dysregulated miRNAs have been considered as the biomarkers for the detection of HCV infection and/or HCV-related diseases. In this review, we intend to briefly summarize the identified miRNAs functioning at HCV replication and pathogenesis, focusing on the recent developments.

Association between genetic variants of microRNA-21 and microRNA-155 and systemic lupus erythematosus: A case-control study from a Chinese population

Background

Systemic lupus erythematosus (SLE) is a common autoimmune disease, and its pathogenesis remains unclear. The alteration of genetic materials is believed to play a role in SLE development. This study evaluated the association between the genetic variants of microRNA‐21 (miR‐21) and microRNA‐155 (miR‐155) and SLE.

Methods

The SNaPshot genotyping method was used to detect the genotypes of selected SNPs in patients and controls. The expression of miR‐21 and miR‐155 was analyzed using reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR). The functional annotation and the biological effects of SNPs were assessed by HaploReg V4.1 and Regulome DB V2.0 software. The Hardy–Weinberg equilibrium test was used to gather statistics, and odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated by logistic regression.

Results

The distribution difference of TA genotype in rs767649 was observed (TA vs. T/T: OR = 0.68, 95%CI, 0.48–0.95, p = 0.026). There was a significant difference in the T/A + A/A (T/A + A/A vs. T/T: OR = 0.68, 95%CI, 0.49–0.94, p = 0.020). A significant difference in T allele distribution was found in the depressed complement of SLE (T vs. A: OR = 0.67, 95%CI, 0.47–0.95, p = 0.026). There were significant differences in genetic variants of rs13137 between the positive and the negative SSB antibodies (Anti‐SSB) (T vs. A: OR = 0.67, 95%CI, 0.47–0.95, p = 0.026; T/A + T/T vs. AA: OR = 2.23, 1.18–4.49, p = 0.013). The expression levels of miR‐21 and miR‐155 were significantly higher in patients than in controls (p < 0.001).

Conclusions

This study provides novel insight that genetic variants of rs767649 and rs13137 are associated with susceptibility to SLE.

MicroRNA-155 expression with Brucella infection in vitro and in vivo and decreased serum levels of MicroRNA-155 in patients with brucellosis

Infection with Brucella is characterized by the inhibition of host immune responses. MicroRNA-155 (miR-155) has been implicated in the immune response to many diseases. In this study, its expression during Brucella 16M infection of macrophages and mice was analyzed. Expression of miR-155 was significantly induced in macrophages at 24 h post infection. Further, an analysis of infected mice showed that miR-155 was inhibited at 7 and 14 days but induced at 28 days. Interestingly, this trend in induction or inhibition was reversed at 7 and 14 days in 16M△virB-infected mice. This suggested that decreased expression of miR-155 at an early stage of infection was dependent on intracellular replication. In humans with brucellosis, serum levels of miR-155 were significantly decreased compared to those in individuals without brucellosis and healthy volunteers. Significant correlations were observed between serum level of miR-155 and serum anti-Brucella antibody titers and the sweating symptom. This effect suggests that Brucella interferes with miR-155-regulated immune responses via a unique mechanism. Taken together, data from this study indicate that Brucella infection affects miR-155 expression and that human brucellosis patients show decreased serum levels of miR-155.

Inhibition of miR-155 Attenuates CD14+ Monocyte-Mediated Inflammatory Response and Oxidative Stress in Psoriasis Through TLR4/MyD88/NF-κB Signaling Pathway

Purpose

Previous studies showed the link of CD14⁺ monocytes to inflammation and oxidation in psoriasis. In the present study, we investigated the regulatory role of miR-155 in CD14⁺ monocyte function in psoriasis.

Materials and Methods

CD14⁺ monocytes were isolated from peripheral blood by magnetic bead separation method and its function was assessed following silence of miR-155 by lentivirus transfection with or without inhibition of TLR4 pathway. CCK8 and EdU were used to assess the proliferation of CD14⁺ monocytes. Expression levels of SOCS1, TLR4 and MyD88 proteins were determined by Western blotting, while expression levels of IL-6, TNF-α, ROS, MDA and T-AOC were measured by ELISA kit. The expression levels of mRNA for miR-155, NF-κB and its subunit NF-κB-p65 were assessed by q-PCR.

Results

The results showed that compared with normal control CD14⁺ monocytes, the expression levels of miR-155, NF-κB and NF-κB-p65, TLR4, MyD88 and IL-6, TNF-α were increased, while expression levels of SOCS1 were decreased in CD14⁺ monocytes from psoriatic patients. Enhanced cell proliferation and oxidation were also observed in CD14⁺ monocytes from psoriatic patients. Inhibition of miR-155 partially corrected the abnormalities of cell proliferation and expression levels of biomarkers mentioned above in CD14⁺ monocytes from psoriatic patients. Inhibitions of both TLR4 pathway and miR-155 further corrected abnormalities of proliferation and the above biomarkers in CD14⁺ monocytes from psoriatic patients.

Conclusion

These results suggest that increased expression levels of miR-155 contribute to CD14⁺ monocyte-mediated inflammation and oxidation in psoriasis via TLR4 pathway.