RESUMO
Hyperuricemia is a chronic metabolic disease caused by the accumulation of uric acid in the body caused by purine metabolism disorder. In recent years, the incidence of hyperuricemia has increased and the age of onset is showing a younger trend. Finding effective therapeutic targets and treatment methods is a hot spot of current research. The urate transporter ATP-binding cassette subfamily G member 2 (ABCG2) is mainly expressed in the kidney and promotes uric acid excretion. In this study, ABCG2 mRNA was synthesized in vitro and transfected into hyperuricemia model mice to observe its effect on mouse uric acid levels. Firstly, the DNA template of ABCG2 mRNA was chemically synthesized, and then transcribed into mRNA in vitro, followed by modification and transfection into mouse TCMK-1 renal tubular epithelial cells. Finally, the protein expression in the cells was detected by Western blot. The results showed that the amount of protein expression in TCMK-1 cells was positively correlated with the amount of transfected mRNA (P < 0. 01), indicating a successful transfection. In animal experiments, twenty-four SPF mice were randomly divided into four groups (n = 6): control group, hyperuricemia model group, benzbromarone group [20 mg/(kg•d)] and mRNA group [2 mg/(kg•3d)]. The mice have been modeled and treated for 28 days. During this period, the body weight and growth status of the mice were monitored daily. After the treatment, the levels of serum uric acid, urine uric acid, serum creatinine, blood urea nitrogen and liver xanthine oxidase were analyzed. The results showed that compared with the model group of mice, mRNA treatment can significantly reduce the levels of serum uric acid (100. 38 ± 10. 94), blood urea nitrogen (6. 30 ± 1. 10), and serum creatinine (30. 86 ± 5. 78, P<0. 05 or P<0. 01). It can also increase the level of urine uric acid (617. 48 ± 50. 34, P<0. 05) in mice and promote the excretion of uric acid. But it has no significant effect on the activity of xanthine oxidase (26. 19 ± 2. 58) in the liver. The pathological changes of mice kidney were observed by HE staining. The results showed that compared with mice in the model group, pathological damages such as renal tubular cell edema and inflammatory cell infiltration in the mRNA treatment group were significantly improved. The relative expression of mRNA in mice kidney was detected by qRT-PCR, and the protein expression of ABCG2 in mice kidney was detected by immunohistochemistry and Western blot. The results showed that the relative expression of ABCG2 mRNA and its protein were significantly up-regulated in the kidney tissues of mice in the mRNA group (P < 0. 01), indicating that the transfection was successful in vivo. In conclusion, ABCG2 mRNA synthetized and modified in vitro can be successfully expressed in hyperuricemia mice and promote excretion of uric acid and other organic ions, as well as improvement of renal injury in mice. These results provide experimental basis for the clinical application of ABCG2 as a target for the treatment of hyperuricemia related diseases.
RESUMO
In recent years, it has become increasingly clear that successful treatment of cancer is possible through the induction of anti-tumor immunity combined with killing of tumor cells. One approach to reach this is to apply cancer vaccines comprising tumor-specific antigens to elicit cellular immunity and chemotherapy to reduce the tumor mass. However, in some cases the dying tumor cell can itself become the vaccine, in particular when the antineoplastic treatment induces so called immunogenic cell death. Immunogenic cell death is characterized by the exposure of damage associated molecular patterns (DAMPs). DAMPs are recognized by innate immune cells which subsequently can prime effector T cell responses against tumor-specific antigens. Unfortunately, many tumors resist exogenous immunogenic cell death stimuli through acquired mutations in cell death signaling pathways. In our recent study (Nat Commun, 9(1):3417), we aimed to overcome these issues through the direct delivery in tumor cells of hypo-inflammatory messenger RNA (mRNA) that codes for mixed lineage kinase domain-like (MLKL) protein, an executioner of necroptosis. This mRNA-based treatment resulted in the potent induction of systemic cellular anti-tumor immune responses that were associated with the regression of the treated as well as distal non-treated tumor cells, as demonstrated in mouse models of transplantable tumors.
