The tumor microenvironment (TME) is critical for tumor progression. However, the establishment and function of the TME remain obscure because of its complex cellular composition. Using a mouse genetic system called mosaic analysis with double markers (MADMs), we delineated TME evolution at single-cell resolution in sonic hedgehog (SHH)-activated medulloblastomas that originate from unipotent granule neuron progenitors in the brain. First, we found that astrocytes within the TME (TuAstrocytes) were trans-differentiated from tumor granule neuron precursors (GNPs), which normally never differentiate into astrocytes. Second, we identified that TME-derived IGF1 promotes tumor progression. Third, we uncovered that insulin-like growth factor 1 (IGF1) is produced by tumor-associated microglia in response to interleukin-4 (IL-4) stimulation. Finally, we found that IL-4 is secreted by TuAstrocytes. Collectively, our studies reveal an evolutionary process that produces a multi-lateral network within the TME of medulloblastoma: a fraction of tumor cells trans-differentiate into TuAstrocytes, which, in turn, produce IL-4 that stimulates microglia to produce IGF1 to promote tumor progression.

Background/Aims: This study aims to investigate the role of circular antisense non-coding RNA at the INK4 locus (cANRIL) in the inflammatory response of vascular endothelial cells (ECs) in a rat model of coronary atherosclerosis (AS). A rat model of AS was established with rats that were injected with a large dose of vitamin D₃ and fed a high-fat diet. Methods: Sixty Wistar rats were randomly assigned into control, model, empty vector, over-expressed cANRIL and low-expressed cANRIL groups (12 rats in each group). Sixteen weeks later, the ultrastructure of their coronary arteries was observed via transmission electron microscopy. Rat serum lipid levels were analyzed using an automatic biochemical analyzer, and their atherogenic index (AI) values were calculated. Hematoxylin and eosin staining was used to observe the endothelial morphology of rats. Additionally, rat EC apoptosis was tested via a TUNEL assay. Enzyme-linked immunosorbent assays (ELISAs) were applied to measure serum levels of interleukin-1 (IL-1), IL-6, matrix metalloproteinase-9 (MMP-9) and C-reactive protein (CRP). The cANRIL, Bax, bcl-2 and caspase-3 mRNA expression levels were measured with a quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression levels of Bax, bcl-2 and caspase-3 were detected using immunohistochemistry. Results: In the control group, ECs were closely arranged with normal structures, and there was no proliferation. In the model, empty vector and over-expressed cANRIL groups, some cells were not present, and atherosclerotic plaques and thrombi appeared. However, in the under-expressed cANRIL group, the cells had a normal structure. Compared with the model and empty vector groups, the levels of total cholesterol (CHOL), triglycerides (TGs), low density lipoprotein (LDL), IL-1, IL-6, MMP-9, CRP, cANRIL, Bax, and caspase-3, AI values, and rates of EC apoptosis decreased in the low-expressed cANRIL group, while HDL (high density lipoprotein) levels and mRNA and protein expression levels of bcl-2 were increased. The changes in expression levels in the over-expressed cANRIL group were the opposite of those in the low-expressed cANRIL group. Conclusions: Our study provides evidence that reduced cANRIL expression could prevent coronary AS by reducing vascular EC apoptosis and inflammatory factor expression.

Enterovirus 71 (EV71) is one of the causative pathogens of hand-foot-and-mouth disease and effective antiviral agents and vaccines against this virus have, to date, not been available. MicroRNAs (miRNAs) are a recently discovered class of RNAs with the function of post-transcriptional gene expression regulation. It has been demonstrated that miRNAs play important roles in the complicated interaction network between virus and host, while few studies have explored the role of miRNAs in EV71 infection. A recent study showed that hsa-miR-23b was downregulated significantly in cell-infected viruses. To address this issue, biological software miRanda was first used to predict possible target sites of miR-23b at EV71 gene sequence, then to confirm it by luciferase assay. miR-23b mimics were transfected to verify its effects on infection of EV71. These results suggest that miR-23b and upregulation of miR-23b inhibited the replication of EV71 by targeting at EV71 3′UTR conserved sequence. Taken together, miR-23b could inhibit EV71 replication through downregulation of EV71 VPl protein. These results may enhance our understanding on the prevention and treatment of hand-foot-and-mouth disease caused by EV71 infection.

Endothelial cell damage caused by oxidative stress is widely considered to be a triggering event in atherosclerosis (AS). However, the specific effect elicited by autophagy in endothelial cells undergoing oxidative stress remains controversial, especially during endstage autophagy. The inhibition of end-stage autophagy has been reported to increase cell pyroptosis and contribute to endothelial damage. Several studies have shown that microRNA-103 is involved in end-stage autophagy; however, its specific mechanism of action is not yet characterized. In this study, we addressed the regulatory role of miR-103 in autophagy during oxidative stress of endothelial cells. Hydrogen peroxide (H 2 O 2 ) treatment was used as an in vitro model of oxidative stress. MTS and ROS levels were measured to evaluate cell activity. qRT-PCR was used to detect the expression of miR-103. Autophagy was examined using western blot, immunofluorescence staining, and electron microscopy, while western blot analysis detected pyroptosis-related proteins. Results show that miR-103 expression decreased under oxidative stress. Further, miR-103 repressed transcription of Bcl-2/adenovirus E1B 19 kDa interacting protein (BNIP3). The oxidative stress caused by H 2 O 2 caused cell damage from 2 hours (P < 0:05) and increased the level of intracellular reactive oxygen species (P < 0:05); at the same time, the damage could be further aggravated by the stimulation of bafA1 (P < 0:05). Under the stimulation of H 2 O 2 , the expression of miR-103 decreased (P < 0:05). However, high expression of miR-103 could reduce the accumulation of LC3II and P62 (P < 0:05) by inhibiting the downstream target gene Bcl-2/adenovirus E1B 19 kDa interacting protein (BNIP3), thus reducing the occurrence of cell pyroptosis (P < 0:05). This process could be blocked by end-stage autophagy inhibitor bafA1 (P < 0:05), which further indicated that miR-103 affected cell injury by autophagy. On the contrary, the low expression of miR-103 promoted the accumulation of autophagy protein and increased the occurrence of pyroptosis (P < 0:05). In conclusion, inhibition of miR-103 restrained end-stage of autophagy by regulating BNIP3, thus changing the occurrence of cell pyroptosis.

Cardiovascular disease is the leading cause of mortality worldwide, and mitochondrial dysfunction is the primary contributor to these disorders. Recent studies have elaborated on selective autophagy-mitophagy, which eliminates damaged and dysfunctional mitochondria, stabilizes mitochondrial structure and function, and maintains cell survival and growth. Numerous recent studies have reported that mitophagy plays an important role in the pathogenesis of various cardiovascular diseases. This review summarizes the mechanisms underlying mitophagy and advancements in studies on the role of mitophagy in cardiovascular disease.