Glaucoma is an irreversible blinding eye disease characterized by apoptosis of mature neurons-retinal ganglion cells (RGCs), visual field defect and vision loss. Regeneration of RGCs and reconstruction of the neural connections between the retina and the brain is considered an effective strategy to promote visual restoration in patients with glaucoma. However, there are currently no effective methods for regenerating RGCs to restore vision in clinical practice. Microglia are a type of glial cells that regulate the immune response in the retina and central nervous system (CNS), whether they have pluripotency and be reversed into RGCs remains unclear and challenging. This study revealed that the ectopic expression of multiple genes (Brn3b, Sox2, Cbln1, and NP1, referred to as BSCN) in microglia can promote their conversion into RGC-like cells by microglia fate lineage tracing in vivo. The regenerated RGC-like cells project axons to the distant brain and reconstruct the visual neural circuit, restoring the impaired vision in adult mice with acute glaucoma induced by retinal ischemia-reperfusion (I/R) injury. Furthermore, the regenerated RGC-like cells could survive stably for up to one year, and the same regeneration strategy was performed in older mice with acute glaucoma, which confirmed the effectiveness of the BSCN reprogramming to regenerate RGC-like cells. In summary, we have identified the microglia as a new type of reprogramming seed cells, and four key genes were found to be involved in regenerating RGC-like cells to restore vision. These findings highlight a new strategy of RGC-like cell regeneration and provide a theoretical basis for treatment of glaucoma in the future.
TP53 mutations are ubiquitous with tumorigenesis in non-small cell lung cancers (NSCLC). By analyzing the TCGA database, we reported that TP53 missense mutations are correlated with chromosomal instability and tumor mutation burden in NSCLC. The inability of wild-type nor mutant p53 expression can't predict survival in lung cancer cohorts, however, an examination of primary NSCLC tissues found that acetylated p53 did yield an association with improved survival outcomes. Molecularly, we demonstrated that acetylation drove the ubiquitination and degradation of mutant p53 but enhanced stability of wild-type p53. Moreover, acetylation of a missense p53 mutation prevented the gain of oncogenic function observed in typical TP53 mutant-expressing cells and enhanced tumor suppressor functions. Consequently, acetylation inducer targeting of missense mutant p53 may be a viable therapeutic goal for NSCLC treatment and may improve the accuracy of current efforts to utilize p53 mutations in a prognostic manner.
Myocardial fibrosis is the characteristic pathology of diabetes-induced cardiomyopathy. Therefore, an in-depth study of cardiac heterogeneity and cell-to-cell interactions can help elucidate the pathogenesis of diabetic myocardial fibrosis and identify treatment targets for the treatment of this disease. In this study, we investigated intercellular communication drivers of myocardial fibrosis in mouse heart with high-fat-diet/streptozotocin-induced diabetes at single-cell resolution. Intercellular and protein–protein interaction networks of fibroblasts and macrophages, endothelial cells, as well as fibroblasts and epicardial cells revealed critical changes in ligand–receptor interactions such as Pdgf(s)–Pdgfra and Efemp1–Egfr, which promote the development of a profibrotic microenvironment during the progression of and confirmed that the specific inhibition of the Pdgfra axis could significantly improve diabetic myocardial fibrosis. We also identified phenotypically distinct Hrchi and Postnhi fibroblast subpopulations associated with pathological extracellular matrix remodeling, of which the Hrchi fibroblasts were found to be the most profibrogenic under diabetic conditions. Finally, we validated the role of the Itgb1 hub gene-mediated intercellular communication drivers of diabetic myocardial fibrosis in Hrchi fibroblasts, and confirmed the results through AAV9-mediated Itgb1 knockdown in the heart of diabetic mice. In summary, cardiac cell mapping provides novel insights into intercellular communication drivers involved in pathological extracellular matrix remodeling during diabetic myocardial fibrosis.
Connexin43 (Cx43)-mediated gap junctions are vital in maintaining corneal endothelium homeostasis. Tumor necrosis factor-alpha (TNF-α) is among the most important inflammatory factors which cause corneal endothelial dysfunction in various eye diseases. However, the effect of TNF-α on Cx43-mediated gap junctions of the corneal endothelium remains undefined. In the current research, we determined the effect of TNF-α on gap junction intercellular communication (GJIC) in rabbit corneal endothelium. To evaluate alterations of GJIC, if any, we treated ex vivo cultured rabbit corneal endothelium with different concentrations of TNF-α (2-20 ng/ml). The localization of Cx43 was analyzed by immunostaining, while RT-qPCR and western blot were used to profile the expression of Cx43 and zonula occludens-1 (ZO-1). The association between ZO-1 and Cx43 was evaluated using immunoprecipitation and double staining. GJIC activity was determined by the scrap loading and dye transfer assay (SLDT). Our data demonstrated that a high concentration of TNF-α (10 ng/ml and 20 ng/ml) disrupts the Cx43 mediated gap junction distribution in rabbit corneal endothelium and suppresses the expression of Cx43 protein. Furthermore, rabbit corneal endothelial GJIC was inhibited due to the decreased association between the ZO-1 and Cx43 proteins. Current results demonstrate that TNF-α inhibits corneal endothelial GJIC via decreasing the association between ZO-1 and Cx43, disrupting the distribution of Cx43, and downregulating the expression of Cx43 protein. This study offers a new theoretical foundation for diagnosing and treating corneal endothelial cell decompensation induced by elevated TNF-α in various eye diseases.
Diabetes-induced cardiomyopathy is characterized by myocardial fibrosis as a main pathology. In-depth study of cardiac heterogeneity and cell-to-cell interactions will help to reveal the pathogenesis of diabetic myocardial fibrosis and provide potential targets for the treatment of this disease. Here, we insighted into the intercellular communication drivers underlying myocardial fibrosis in mouse heart with high-fat-diet (HFD)/streptozotocin (STZ)-induced diabetes at single-cell resolution. Intercellular and protein-protein interaction networks of fibroblasts and macrophages, endothelial cells, as well as fibroblasts and epicardial cells reveal critical changes in ligand-receptor interactions such as Pdgf(s)-Pdgfra and Efemp1-Egfr, which promote the development of a profibrotic microenvironment during diabetes progression and confirm that specific inhibition of Pdgfra axis can significantly improve diabetic myocardial fibrosis. We further identified the phenotypically distinct Hrc hi and Postn hi fibroblast subpopulations that are associated with pathological extracellular matrix remodeling, of which Hrc hi fibroblasts are the most profibrogenic under diabetic conditions. Finally, we validated the role of Itgb1 hub gene mediated intercellular communication drivers of diabetic myocardial fibrosis in Hrc hi fibroblasts, and confirmed the result by AAV9-mediated Itgb1 knockdown in the heart of diabetic mice. In summary, cardiac cell mapping provides novel insights into intercellular communication drivers underlying pathological extracellular matrix remodeling during diabetic myocardial fibrosis.
Previous studies have demonstrated that glucocorticoid receptor β (GRβ) functions as an oncoprotein, regulating the malignant phenotypes and stem-like cell maintaining in human glioblastoma (GBM). Of the glucocorticoid receptor (GR) isoforms, GRβ and GRα are highly homologous, though the mechanism underlying the distinct functions of these two isoforms in GBM has not been clarified. Here by establishing a carboxyl-terminal (COOH-terminal) deletion mutant, we determined that GRβ can be ubiquitinated. We also found that its COOH terminal is essential for this ubiquitination. The mutation of a lysine to arginine at residue 733 (K733R) blocked the ubiquitination of GRβ, indicating that K733 is a key site for ubiquitination. Using K733R to establish nonubiquitinated GRβ, we demonstrated that ubiquitination not only regulates the stability and nuclear translocation of GRβ, but is also a vital mechanism for its oncogenic functions in vitro and in vivo. Protein interaction assay further indicated that ubiquitin-specific protease 49 (USP49) is a GRβ-binding protein and the interaction depends on GRβ ubiquitination. USP49 knockdown resulted in a decrease of cell proliferation, invasion, and an increase of cell apoptosis. More importantly, USP49 knockdown increased ubiquitination and amplified the oncogenic effects of GRβ, confirming the decisive role of ubiquitination on GRβ carcinogenicity. Taken together, these findings established that ubiquitination is a vial process for GRβ the execution of oncogenic functions in GBM and that the K733 site is crucial for ubiquitination of GRβ. IMPLICATIONS: This work is the first identify of the activation GRβ by a single lysine point-mediated ubiquitination and proteasome degradation, which determines its oncogenic functions in GBM.
目的 在CRISPR/Cas9敲除SRSF9基因的胶质母细胞瘤U87单克隆株中进行SRSF9基因回补并进行回补功能研究.方法 构建SRSF9-WT过表达载体并同义突变sgRNA1靶序列上的5个碱基构建SRSF9-sgMu过表达载体并包装成慢病毒,感染U87 SRSF9基因敲除单克隆细胞,构建SRSF9基因回补细胞株.利用Western blot和免疫荧光实验验证回补蛋白的定位,利用增殖和肿瘤干细胞成球实验验证回补基因的拯救功能.结果 成功构建SRSF9-WT和SRSF9-sgMu过表达载体并包装成慢病毒.Western blot和免疫荧光实验验证回补成功,且回补的SRSF9蛋白优势表达于细胞核.增殖和肿瘤干细胞成球实验证明回补的SRSF9可以拯救其功能(P<0.05).结论 SRSF9-sgMu成功在SRSF9基因敲除的U87单克隆细胞中回补SRSF9并拯救增殖和肿瘤干细胞成球功能.
Abstract Background: Glioblastoma is an aggressive primary tumour with the lowest survival time among brain tumours. Tumour-infiltrating immune cells (TIICs) are involved in tumour progression and determine the prognosis, while the association of immune cell infiltration with glioblastoma is rarely unknown. This study aimed to screen survival-related (SR) genes and major biological processes through bioinformatic analysis and to identify the relationship between SR genes and TIICs.Methods:SR genes were screened by comparing the long-term (>36 months) and short-term (<12 months) survivors in the database GSE53733. Gene set enrichment analysis (GSEA) was applied to compare the differences in biological processes between long-term survivors and short-term survivors. The SR genes were identified using the limma package of R. Gene Ontology (GO) analysis was conducted through Metascape. The protein-protein interaction (PPI) network of the SR genes was established through the Search Tool for the Retrieval of Interacting Genes (STRING) website and further analysed by the Molecular Complex Detection (MCODE) algorithm. UALCAN and GlioVis were employed to analyse the expression levels and prognostic value of hub genes. The correlation of hub genes with immune cell filtration was estimated by the Tumor Immune Estimation Resource (TIMER). The gene-drug interaction network was constructed using the Comparative Toxicogenomics Database (CTD).Results: The functions of the detected genes were mainly enriched in epithelial mesenchymal transition (EMT) and oxidative phosphorylation. Of the detected genes, a total of 220 SR genes were identified, including 78 upregulated genes and 142 downregulated genes in long-term survivors. The upregulated genes were mainly related to neuron projection morphogenesis, extracellular matrix, and cation channel activity. The downregulated genes were mainly related to extracellular matrix organization and angiogenesis. The PPI network for SR genes was constructed with 65 edges and 195 nodes, and two significant modules were selected. The results indicated that COL1A2, COL6A2, COL8A1, and COL8A2 were hub SR genes. In addition, they were correlated with immune cell infiltration, especially dendritic cell infiltration.Conclusions: These results revealed that collagens accounted for the progression and prognosis of glioblastoma. In addition, DC infiltration is a risk factor for glioblastoma patients. The expression of collagen protein COL6A2 was significantly correlated with the DC infiltration level and poor prognosis. Further, potential drugs that affect the function of COL6A2 could improve the outcomes of glioblastoma.
Metastatic osteosarcoma usually has an unsatisfactory response to the current standard chemotherapy and causes poor prognosis. Currently, epithelial-mesenchymal transition (EMT) is reported as a critical event in osteosarcoma metastasis. Glaucocalyxin A, a bioactive ent-kauranoid diterpenoid, exerts anti-cancer effect on osteosarcoma by inducing apoptosis in previous study. However, the effect of Glaucocalyxin A on EMT and metastasis of osteosarcoma is unclear. In this study, we investigated the potential mechanisms of Glaucocalyxin A on EMT and metastasis of osteosarcoma. We found that Glaucocalyxin A inhibited migration and invasion of MG-63 and 143B cells. Moreover, Glaucocalyxin A increased the protein and mRNA levels of E-cadherin and decreased the protein and transcription expression of N-cadherin, Vimentin. Glaucocalyxin A also inhibited the protein and mRNA levels of EMT-associated transcription factor including Snail and Slug. Furthermore, Glaucocalyxin A inhibited transforming growth factor-β1 (TGF-β1)-induced migration, invasion and EMT of low-metastatic osteosarcoma U2OS cells. Glaucocalyxin A inhibited TGF-β-induced phosphorylation of Smad 2/3 in osteosarcoma U2OS cells. Finally, we established transplanted metastatic models of highly metastatic osteosarcoma 143B cells. Glaucocalyxin A inhibited lung metastasis in vivo. Interestingly, Glaucocalyxin A increased the protein expression of E-cadherin and reduced the protein expression of N-cadherin and Vimentin. Glaucocalyxin A inhibited the protein expression of Snail and Slug in vivo. In summary, this study demonstrated that Glaucocalyxin A inhibited EMT and TGF-β1-induced EMT by inhibiting TGF-β1/Smad2/3 signaling pathway in osteosarcoma. Therefore, Glaucocalyxin A might be a promising candidate against the metastasis of human osteosarcoma.
目的 人胶质母细胞瘤细胞细胞系U87被作为胶质母细胞瘤(GBM)异质性研究的模型,但从基因水平探讨其异质性来源的研究较少.文章旨在构建人胶质母细胞瘤细胞系U87单克隆细胞株,检测不同单克隆细胞株的表型和遗传背景差异,并探讨产生表型差异的分子机制.方法 利用小分子荧光染料羟基荧光素二醋酸盐琥珀酰亚胺脂(CFSE)作为筛选标记,有限稀释法构建U87单克隆细胞株,并挑选具有典型形态特征的2株单克隆化细胞,经短串联重复序列(STR)鉴定后进行后续研究.采用CCK-8、EdU掺入法增殖实验和和平板克隆形成实验检测细胞增殖能力;肿瘤干细胞成球实验检测细胞成球能力;免疫荧光和CCK-8法黏附实验检测细胞黏附能力;3D侵袭实验检测细胞侵袭能力;Annexin V/PI双染流式细胞术检测细胞对化疗药物的敏感性;转录组测序(RNA-seq)对细胞进行测序及生物信息学分析;qRT-PCR验证富集通路中代表性差异基因mRNA表达量.结果 构建了形态较为均一U87单克隆细胞株CF5和G11.其中CF5小而短粗,G11大而细长.CCK-8增殖实验结果显示,CF5细胞增殖能力较U87、G11明显增强,U87较G11明显增强(P<0.001).EdU掺入法增殖实验结果显示,CF5 EdU阳性细胞比例(0.54±0.05)较G11细胞(0.35±0.03)、U87(0.44±0.03)明显增加,U87较G11明显增强(P<0.01).肿瘤干细胞成球实验显示,CF5干细胞成球能力较U87、G11明显增强,U87较G11明显增强(P<0.01).免疫荧光法黏附实验显示,黏附1 h后G11黏附面积较U87、CF5明显增强,U87较CF5明显增强(P<0.001).3D培养侵袭实验结果显示,G11细胞侵袭能力较U87、CF5明显增强,U87较CF5明显增强(P<0.05).交互分析发现CF5相对G11和U87均下调的基因159个,均上调的基因303个;G11相对CF5和U87均下调的基因有281个,上调的基因则有116个;通路富集分析显示CF5和G11在细胞外基质相关的通路有最高的富集度,细胞外基质相关通路与肿瘤侵袭、耐药等功能表型密切相关.结论 成功构建从形态、功能表型到基因背景具有显著差异的U87单克隆细胞株CF5、G11,为研究GBM异质性和基因功能奠定了基础.