In fat grafting, macrophages and their polarization initiated changes in the levels of dominant secreted factors and influenced blood-derived stem cell infiltration, indicating that macrophages were crucial for tissue revascularization. The macrophage manipulation models described here show that graft macrophage number can profoundly influence graft survival.
Pevonedistat (MLN4924), a specific NEDD8‐activating enzyme inhibitor, has been considered as a promising treatment for glioblastoma, which is currently in Phase I/II clinical trials. On the other hand, inhibition of neddylation pathway substantially upregulates the expression of T cell negative regulator programmed death‐ligand 1 (PD‐L1), which might account for the potential resistance via evasion of immune surveillance checkpoints. Whether administration of anti‐PD‐L1 enhances the efficacy of pevonedistat through a cytotoxic T cell‐dependent mechanism in glioblastoma needs to be investigated. Here, we report that depletion of neddylation pathway key enzymes markedly elevates PD‐L1 expression in glioblastoma cancer cells. Consistently, neddylation inhibitor pevonedistat significantly enhances PD‐L1 expression in both glioblastoma cancer cell lines and animal models. Mechanistically, pevonedistat increases PD‐L1 mRNA levels mainly through inhibiting Cullin1‐F‐box and WD repeat domain‐containing 7 E3 ligase activity and accumulating c‐MYC proteins, a direct transcriptional activator of PD‐L1 gene expression. In addition, inhibition of Cullin3 activity by pevonedistat also blocks PD‐L1 protein degradation. Importantly, pevonedistat attenuates T cell killing through PD‐L1 induction, and blockade of PD‐L1 restores the sensitivity of pevonedistat‐treated glioblastoma cancer cells to T cell killing. The combination of pevonedistat and anti‐PD‐L1 therapy compared to each agent alone significantly increased the therapeutic efficacy in vivo. Our study demonstrates inhibition of neddylation pathway suppresses cancer‐associated immunity and provides solid evidence to support the combination of pevonedistat and PD‐L1/programmed cell death protein 1 immune checkpoint blockade as a potential therapeutic strategy to treat glioblastoma.
Ovarian folliculogenesis is always of great interest in reproductive biology. However, the molecular mechanisms that control follicle development, particularly the early phase of follicle activation or recruitment, still remain poorly understood. In an attempt to decipher the gene networks and signaling pathways involved in such transition, we conducted a transcriptomic analysis (RNA-seq) on zebrafish primary growth (PG, stage I; inactive) and previtellogenic (PV, stage II; activated) follicles. A total of 118 unique microRNAs (miRNAs) (11 downregulated and 83 upregulated during PG/PV transition) and 56711 unique messenger RNAs (mRNAs) (1839 downregulated and 7243 upregulated during PG/PV transition) were identified. Real-time quantitative polymerase chain reaction analysis confirmed differential expression of 46 miRNAs from 66 candidates (66.67%). Among which, we chose to focus on 13 miRNAs (let-7a, -7b, -7c-5p, -7d-5p, -7h, -7i; miR-21, -23a-3p, -27c-3p, -107a-3p, -125b-5p, -145-3p, and -202-5p) that exhibited significant differential expression between PG and PV follicles (P ≤ 0.045*). With this 13-miRNA expression signature alone, PG follicles can be well differentiated from PV follicles by hierarchical clustering, suggesting their functional relevance during PG-to-PV transition. By overlaying predicted target genes and the differentially expressed mRNAs revealed by the RNA-seq analysis, especially those showing reciprocal miRNA-mRNA expression patterns, we shortlisted a panel of miRNA downstream targets for luciferase reporter validation. The reporter assay confirmed the interactions of let-7i:: atg4a (P = 0.01*), miR-202-5p::c23h20orf24 (P = 0.0004***), and miR-144-5p::ybx1 (P = 0.003**), implicating these potential miRNA-mRNA gene pairs in follicle activation during folliculogenesis. Our transcriptomic data analyses suggest that miRNA-mediated post-transcriptional control may represent an important mechanism underlying follicle activation.
Platelets-rich plasma (PRP) can produce growth factors (GFs) to improve angiogenesis. However, direct injection of PRP does not lead to highly localized GFs. The current study employs a mussel-inspired polydopamine to immobilize PRP on gelatin microspheres (GMs) with the purpose of bridging adipose micro-tissues to help implanted fat survive (GM-pDA-PRP). Enhanced PRP adhesion leads to a prolonged and localized production of GFs, which is verified by platelet counting and by ELISA of vascular endothelial growth factors (VEGFs) and of platelet derived growth factors (PDGFs). The GM-pDA-PRP "hatches" a microenvironment for the proliferation of adipose-derived stem cells. After the adipose micro-tissue has bridged with GM-pDA-PRP after 16 weeks, triple-fluorescence staining reveals that the mature adipocytes, blood vessels, and capillaries are arranged like in normal adipose tissue. The survival fat increases significantly compared to that in control, PRP, and GM-PRP groups (84.8 ± 11.4% versus 47.8 ± 8.9%, 56.9 ± 9.7%, and 60.2 ± 10.5%, respectively). Both histological assessments and CD31 immunofluorescence indicate that the improvement of angiogenesis in GM-pDA-PRP is higher than in the fat graft group (6.4-fold in quantitative CD31 positive cells). The CD34 positive cells in the GM-pDA-PRP group are around 3.5-fold the amount in the fat graft group, which suggests that more stem cells migrate to the implant area. Cell proliferation staining shows that the number of Ki67 positive cells is around five times as high as that in the fat graft group.
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