Exosomal miR-19a derived from melanoma cell promotes the vemurafenib resistance of malignant melanoma through directly targeting LRIG1 to reactivate AKT and MAPK pathway.

Exosomes derived from neighboring v-raf murine sarcoma viral oncogene homolog B1 inhibitor (BRAFi)-resistant melanoma cells mediate the formation of resistance in melanoma cells sensitive to BRAFi. The function and molecular mechanisms of exosomal miRNA in BRAFi resistance of melanoma have not been studied. We found that the expression of miR-19a in BRAFi resistant melanoma cells was significantly higher than that in sensitive cells, and miR-19a contributes to the resistance of melanoma cells to BRAFi by targeting immunoglobulin-like domains protein 1 (LRIG1). miR-19a was highly enriched in exosomes secreted from BRAFi resistant melanoma cells, and these exosomal miR-19a promote the spread of BRAFi resistant. The reactivation of Protein kinase B (AKT) and mitogen-activated protein kinase (MAPK) pathways is the main reason for the BRAFi resistant of melanoma cells. We demonstrated that exosomal miR-19a derived from melanoma cell promotes the formation and spread of BRAFi resistant in melanoma through targeting LRIG1 to reactivate AKT and MAPK pathway. Therefore, miR-19a may serve as a potential therapeutic target in melanoma patients with acquired drug resistance.

E2F1 Mediates Traumatic Brain Injury and Regulates BDNF-AS to Promote the Progression of Alzheimer's Disease.

Traumatic brain injury (TBI) is one of the important risk factors for the development of Alzheimer's disease (AD). However, the molecular mechanism by which TBI promotes the progression of AD is not elucidated. In this study, we showed that the abnormal production of E2F1 is a major factor in promoting the neuropathological and cognitive deterioration of AD post-TBI. We found that repeated mild TBI can aggravate the neuropathology of AD in APP/PS1 mice. At the same time, the co-expression of E2F1 and beta-site APP cleaving enzyme 1 (BACE1) was upregulated when the mouse hippocampus was dissected. BACE1 is recognized as a rate-limiting enzyme for the production of Aß. Here, we speculate that E2F1 may play a role in promoting BACE1 expression in AD. Therefore, we collected peripheral blood from patients with AD. Interestingly, there is a positive correlation between E2F1 and brain-derived neurotrophic factor-antisense (BDNF-AS), whereas BDNF-AS in AD can promote the expression of BACE1 and exhibit a neurotoxic effect. We established a cell model and found a regulatory relationship between E2F1 and BDNF-AS. Therefore, based on our results, we concluded that E2F1 regulates BDNF-AS, promotes the expression of BACE1, and affects the progression of AD. Furthermore, E2F1 mediates the TBI-induced neurotoxicity of AD.

LncRNA BDNF-AS as ceRNA regulates the miR-9-5p/BACE1 pathway affecting neurotoxicity in Alzheimer's disease.

INTRODUCTION: The long non-coding RNA Brain-derived nutritional factor anti-sense RNA (BDNF-AS) is a type of anti-sense RNA that has been proven to play a crucial role in the occurrence and development of certain nervous system disorders. However, the role and molecular mechanism of BDNF-AS in Alzheimer's disease (AD) have not been elucidated yet. METHODS: Peripheral blood samples were collected from outpatients with AD as well as from normal elderly individuals in the community, and the expression of BDNF-AS was analysed using quantitative reverse transcription-polymerase chain reaction. An in vitro model was constructed, and the effect of BDNF-AS expression level on the cells was measured using the CCK8 method and flow cytometry. The molecular biological mechanism of BDNF-AS in AD was examined using the luciferase reporter, MS2-RIP, and RNA pulldown assays. RESULT: We found that the expression of BDNF-AS was elevated in the peripheral blood of patients with AD and that increased BDNF-AS expression may be associated with the cognitive status of such patients. The results confirmed that BDNF-AS could promote neurotoxicity in the in vitro model. Then, we uncovered that BDNF-AS promotes the expression of BACE1 through the competitive binding of miR-9-5p, thereby promoting amyloid deposition. Finally, through the Morris water maze, we found that the high expression of BDNF-AS promoted cognitive impairment in AD mice. CONCLUSION: The obtained results suggest that BDNF-AS plays a crucial role in the occurrence and development of AD. As a new pathogenic gene of AD, BDNF-AS may be used as a therapeutic target or as a prognostic marker in patients with AD.

Exercise combined with trimetazidine improves anti-fatal stress capacity through enhancing autophagy and heat shock protein 70 of myocardium in mice.

Background: Anti-stress capacity is important to resist the occurrence of adverse events. To observe the effects of exercise, trimetazidine alone or combined on the anti-stress capacity of mice, and further explore its potential mechanism. Methods: Forty-four C57BL/6 male mice aged 8 weeks were randomly divided into four groups (n=11 for each group): control group (group C), exercise group (group E), trimetazidine group (group T), exercise combined with trimetazidine group (group TE). After the intervention, each group was randomly subdivided into the exhaustive exercise (EE, n=6) and the non-EE (n=5) subgroups. The mice in the EE-subgroup underwent EE. Mice were sacrificed 12 hours later after EE. The myocardial ultrastructure and autophagosomes were observed under an electron microscope. The expression of autophagy-related proteins: BNIP3, LC3-II, and P62 were analyzed and the heat shock protein 70 mRNA transcription and protein expression were also investigated. Results: Exercise or trimetazidine increased the expression of BNIP3, LC3-II, and heat shock protein 70, decreased the expression of P62 pre- and post-EE while the combination has the synergistic effect. Conclusion: Exercise and trimetazidine, alone or combined enhanced the anti-stress capacity of mice significantly. The underlying mechanism may be associated with the promotion of autography and the expression of heat shock protein 70.

Long noncoding RNA MIR4435-2HG promotes hepatocellular carcinoma proliferation and metastasis through the miR-22-3p/YWHAZ axis.

Long noncoding RNAs (lncRNAs) play the critical biological role in many malignant tumours. MIR4435-2HG has been proven to be a novel oncogenic lncRNA. However, the exact role and mechanism of MIR4435-2HG in hepatocellular carcinoma (HCC) remain unclear. Here, we found that MIR4435-2HG is overexpressed in HCC tissue compared to normal controls and that high level of MIR4435-2HG indicates a poorer prognosis in HCC patients. MIR4435-2HG enhances the growth and metastasis ability of HCC cells. MIR4435-2HG promotes the expression of YWHAZ by sponging miR-22-3p to liberate YWHAZ mRNA transcripts. MIR4435-2HG facilitates the proliferation and metastasis of HCC by modulating the miR-22-3p/YWHAZ axis. These results demonstrated the role and mechanism of MIR4435-2HG in malignant progression of HCC. MIR4435-2HG may be used as the prognostic marker and treatment target for the patient with HCC.