New Possible Ways to Use Exosomes in Diagnostics and Therapy via JAK/STAT Pathways

Exosomes have the potential to be the future of personalized diagnostics and therapy. They are nano-sized particles between 30 and 100 nm flowing in the extracellular milieu, where they mediate cell-cell communication and participate in immune system regulation. Tumor-derived exosomes (TDEs) secreted from different types of cancer cells are the key regulators of the tumor microenvironment. With their immune suppressive cargo, TDEs prevent the antitumor immune response, leading to reduced effectiveness of cancer treatment by promoting a pro-tumorigenic microenvironment. Involved signaling pathways take part in the regulation of tumor proliferation, differentiation, apoptosis, and angiogenesis. Signal transducers and activators of transcription factors (STATs) and Janus kinase (JAK) signaling pathways are crucial in malignancies and autoimmune diseases alike, and their potential to be manipulated is currently the focus of interest. In this review, we aim to discuss exosomes, TDEs, and the JAK/STAT pathways, along with mediators like interleukins, tripartite motif proteins, and interferons.

LncRNA-135528 inhibits tumor progression by up-regulating CXCL10 through the JAK/STAT pathway

Spontaneous tumor regression can be observed in many tumors, however, studies related to the altered expression of lncRNA in spontaneous glioma regression are limited, and the potential contributions of lncRNAs to spontaneous glioma regression remain unknown. To investigate the biological roles of lncRNA-135528 in spontaneous glioma regression. The cDNA fragment of lncRNA-135528 was obtained by rapid-amplification of cDNA ends (RACE) technology and cloned into the plvx-mcmv-zsgreen-puro vector. Additionally, we stably silenced or overexpressed lncRNA-135528 in G422 cells by transfecting with siRNA against lncRNA-135528 or lncRNA-135528 overexpression plasmid. Then, we examined lncRNA-135528 overexpressing and lncRNA-135528 silencing on glioma cells and its effects on CXCL10 and JAK/STAT pathways. The main findings indicated that lncRNA-135528 promoted glioma cell apoptosis, inhibited cell proliferation and arrested cell cycle progression; the up-regulation of lncRNA135528 led to significantly increased CXCL10 levels and the differential expression of mRNA associated with JAK/STAT pathway in glioma cells. lncRNA-135528 can inhibit tumor progression by up-regulating CXCL10 through the JAK/STAT pathway.

Withasteroid B from D. metel L. regulates immune responses by modulating the JAK/STAT pathway and the IL-17+ RORγt+ /IL-10+ FoxP3+ ratio

Datura metel L. is a medicinal herb that contains withasteroids and has a wide range of biological activities. We isolated seven withasteroids from the flowers of D. metel L and examined their ability to inhibit immune responses in vitro and in vivo. Among the withasteroids, withasteroid B2 exhibited the strongest inhibitory effect on immune responses comparing B2 with other isolated compounds from D. metel L., including suppressing the differentiation of CD4⁺ T cells by inhibiting the expression and production of T cell lineage-specific master regulators and cytokines and directly suppressing the cytokine-induced Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathways. In the interleukin (IL)-23-induced mouse ear model of skin disease, B2 repressed disease development by inhibiting the expression of proinflammatory mediators in murine ear skin. Moreover, B2 affected the maturation of dendritic cells (DCs) in vitro which, in turn, induced T cell differentiation with an increased regulatory T cell (T_reg ) phenotype and decreased T helper type 17 (Th17) phenotype. This study provides new evidence that B2 might ameliorate chronic inflammatory skin diseases by suppressing pathogenic CD4⁺ T cell differentiation and the IL-17⁺ retinoic-acid-receptor-related orphan receptor gamma t (RORγt)⁺ /IL-10⁺ forkhead box protein 3 (FoxP3)⁺ ratio. These findings suggest that B2 might mediate the therapeutic effects observed in psoriasis patients following treatment with D. metel L.

Knockdown of ANRIL aggravates H2O2-induced injury in PC-12 cells by targeting microRNA-125a

Spinal cord injury (SCI) is a devastating and common neurological disorder which causes local oxidative damage. The study aimed to investigate the underlying role of ANRIL in H₂O₂-induced cell injury of rat PC-12 cells. Cell injury was evaluated on the basis of cell viability, migration, invasion and apoptosis. The effect of ANRIL on H₂O₂-induced cell injury was estimated after cell transfection. Then, the interaction between ANRIL and miR-125a was explored by qRT-PCR and estimation of cell injury. Predicted by TargetScan, the possible target gene of miR-125a was verified. After that, the effects of aberrantly expressed target gene on cell viability, migration, invasion and apoptosis as well as phosphorylation of key kinases involved in JAK/STAT and ERK/MAPK pathways were evaluated. Results revealed that H₂O₂-induced PC-12 cell injury could be aggravated by ANRIL suppression. ANRIL appeared to act as a sponge of miR-125a, and ANRIL suppression promoted H₂O₂-induced cell injury by up-regulation of miR-125a. MCL-1 was a target of miR-125a, and MCL-1 was negatively correlated with miR-125a. Subsequent experiments showed the effect of MCL-1 silence on H₂O₂-induced PC-12 cell injury was the same as ANIRL suppression. MCL-1 attenuated H₂O₂-induced PC-12 cell injury by activating JAK/STAT and ERK/MAPK pathways. These findings suggested that knockdown of ANRIL aggravates H₂O₂-induced injury in PC-12 cells by targeting miR-125a. This might provide novel insights in the role of ANRIL in pathogenesis of oxidative damage during SCI.

Protective effect of curcumin on TNBS-induced intestinal inflammation is mediated through the JAK/STAT pathway

Background

Curcumin displays a protective role in rat models of intestinal inflammation. However, the mechanism of how curcumin affects on intestinal inflammation is less known. The purpose of the current study is to explore the signal pathway in which the curcumin protecting rat from intestinal inflammation.

Methods

The intestinal inflammation rat models were made by TNBS treatment. Curcumin was added to their diet 5 days before the TNBS instillation. After that, body weight change, score of macroscopic assessment of disease activity and microscopic scoring were utilized to analyse the severity of the induced inflammation. In addition, the level of pro-inflammatory cytokines and anti-inflammatory were detected to determine the effect of curcumin on intestinal inflammation. The JAK/STAT pathway of pro-inflammation response was also evaluated. Finally, the impact of curcumin on apoptosis in intestinal inflammation was assessed by TUNEL staining.

Results

Rats pretreated with curcumin significantly reversed the decrease of body weight and increase of colon weight derived from TNBS-induced colitis. Histological improvement was observed in response to curcumin. In addition, curcumin attenuated TNBS-induced secretion of pro-inflammatory cytokines and M1/M2 ratio, while stimulated the secretion of anti-inflammatory cytokines. The inhibition of pro-inflammation response was mediated by SOCS-1, which could efficiently suppress JAK/STAT pathways. Furthermore, curcumin efficiently suppressed the TNBS-induced apoptosis, and reduced the accumulation of cytochrome C in cytosol.

Conclusion

The anti-inflammatory effect of curcumin is realized by enhancing SOCS-1 expression and inhibiting JAK/STAT pathways. Curcumin also plays an anti-apoptotic role in TNBS-induced intestinal inflammation. We propose that curcumin may have therapeutic implications for human intestinal inflammation.