Applied Biosystems 7900

Objective. The aim of this study is to confirm the hepatocellular protective functions of apigenin and the molecular mechanism on liver fibrosis in mice. Methods. Carbon tetrachloride (CCl4) and bile duct ligature (BDL) mouse fibrosis models were used to investigate the effects of apigenin on liver fibrosis. Sixty-six male C57 mice were randomly divided into eight groups, including the vehicle group, CCl4 group, CCl4+L-apigenin (20 mg/kg) group, CCl4+H-apigenin (40 mg/kg) group, sham group, BDL group, BDL+L-apigenin(20 mg/kg) group, and BDL+H-apigenin(40 mg/kg) group. Serum liver enzymes (ALT and AST), proteins associated with autophagy, and indicators linked with the TGF-β1/Smad3 and p38/PPARα pathways were detected using qRT-PCR, immunohistochemical staining, and western blotting. Results. Our findings confirmed that apigenin could decrease the levels of ALT and AST, suppress the generation of ECM, inhibit the activation of HSCs, regulate the balance of MMP2 and TIMP1, reduce the expression of autophagy-linked protein, and restrain the TGF-β1/Smad3 and p38/PPARα pathways. Conclusion. Apigenin could alleviate liver fibrosis by inhibiting hepatic stellate cell activation and autophagy via TGF-β1/Smad3 and p38/PPARα pathways.

Jie Ji, Qiang Yu, Weiqi Dai, Liwei Wu, Jiao Feng, Yuanyuan Zheng, Yan Li, Chuanyong Guo. PPAR Research, 2021, 1-15, 2021.

Background: Currently, more and more circular RNAs (circRNAs) have been identified to exert their functions in tumor progression, including colorectal cancer (CRC). However, the role of circSEC24A (circ_0003528) in CRC remains unknown.Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine the levels of circSEC24A, SEC24A and microRNA-488-3p (miR-488-3p). The characterization of circSEC24A was investigated by Actinomycin D and RNase R digestion assays. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to assess cell proliferation. Flow cytometry analysis was adopted for cell apoptosis and cell cycle process. Transwell assay was employed to evaluate cell migration and invasion. Western blot assay was performed to determine protein levels. Dual-luciferase reporter assay was utilized to explore the relationship between miR-488-3p and circSEC24A or transmembrane protein 106B (TMEM106B). Murine xenograft model was constructed to explore the effect of circSEC24A in vivo .Results: CircSEC24A level was increased in CRC tissues and cells. CircSEC24A deficiency impeded cell proliferation, cell cycle process, migration and invasion and induced apoptosis in CRC cells in vitro and blocked tumorigenesis in vivo . MiR-488-3p was a target of circSEC24A and miR-488-3p was downregulated in CRC tissues and cells. The inhibitory effect of circSEC24A silencing on CRC cell progression was restored by miR-488-3p inhibition. Moreover, TMEM106B could be negatively regulated by miR-488-3p via acting as a downstream gene of miR-488-3p. MiR-488-3p overexpression decelerated CRC cell progression by targeting TMEM106B.Conclusion: CircSEC24A facilitated CRC progression by regulating miR-488-3p/TMEM106B axis, which might provide a promising treatment approach for CRC.

Gaowu Hu, Wei Peng, Yongqing Cao. 2020.

Background: Glioma, the most common primary brain tumor, account Preparing figures s for 30% to 40% of all intracranial tumors. Herein, we aimed to study the effects of M2 macrophage-derived exosomal microRNAs (miRNAs) on glioma cells. Methods: First, we identified seven differentially expressed miRNAs in infiltrating macrophages and detected the expression of these seven miRNAs in M2 macrophages. We then selected hsa-miR-15a-5p (miR-15a) and hsa-miR-92a-3p (miR-92a) for follow-up studies, and confirmed that miR-15a and miR-92a were under-expressed in M2 macrophage exosomes. Subsequently, we demonstrated that M2 macrophage-derived exosomes promoted migration and invasion of glioma cells, while exosomal miR-15a and miR-92a had the opposite effects on glioma cells. Next, we performed the target gene prediction in four databases and conducted target gene validation by qRT-PCR, western blot and dual luciferase reporter gene assays. Results: The results revealed that miR-15a and miR-92a were bound to CCND1 and RAP1B, respectively. Western blot assays demonstrated that interference with the expression of CCND1 or RAP1B reduced the phosphorylation level of AKT and mTOR, indicating that both CCND1 and RAP1B can activate the PI3K/AKT/mTOR signaling pathway. Conclusion: Collectively, these findings indicate that M2 macrophage-derived exosomal miR-15a and miR-92a inhibit cell migration and invasion of glioma cells through PI3K/AKT/mTOR signaling pathway.

Jie Yao, Ze-Fen Wang, Yong Cheng, Tian Lan, Chao Ma, Ya-Hua Zhong, Yi-Lei Xiao, Xu Gao, Zhi-Qiang Li. 2020.

Background: Recently, more and more treatment strategies for Hepatocellular carcinoma (HCC) have emerged, but the therapeutic effect is still not satisfactory. This study is aimed to explore the mechanism of Interleukin 35 (IL-35) in promoting the progression of liver cancer and to explore the application value of IL-35 in the treatment of HCC.Methods: We used clinical tissue microarray (TMA) immunohistochemistry (IHC) to explore the prognostic value of IL-35 expression in patients with HCC. The effect of IL-35 on the function of HCC was explored by functional experiments including wound-healing assay, transwell, cell counting kit-8, cell adhesion assay and endothelial tube formation assay in vitro and mouse xenografts in vivo. And flow cytometry was used to study the effect of IL-35 on infiltrating immune cells in tumor. The molecular mechanism of the function of IL-35 on the progression of HCC was explored by sequencing, ELISA, WB, PCR and other technical means. Finally, through in vivo tumor animal experiments to explore the value of anti-IL-35 antibody and combined with anti-PD-1 antibody in the treatment of liver cancer.Results: High expression of IL-35 in patients with HCC were identified to be associated with poor prognosis. And we have found that IL-35 facilitated tumor progression by affecting neutrophil infiltration, angiogenesis, and CD8+ T-cell infiltration in a mouse model. Additionally, on the one hand C-C motif chemokine ligand 3 (CCL3) has been found to be a key factor mediating the recruitment of neutrophils by IL-35, on the other hand fibroblast growth factor 2 (FGF2) secreting by neutrophil when stimulated by IL-35 was also found to be the core cytokine to promote intratumoral angiogenesis. And IL-35 was also discovered to facilitated the adhesion of tumor to endothelial cells, with neutrophils further enhancing this effect in vitro and vivo. More important, anti-IL-35 antibody was found to be a valid treatment for HCC in xenograft tumor model, and it could give full play to the curative effect of 1:1＞2 when combination therapy with PD-1 antibody.Conclusion: Our data show that the expression of IL-35 in patients with HCC is an important tumor promoting factor. The application of anti-IL-35 antibody and treatment combined anti-IL-35 antibody with anti-PD-1 antibody have potential therapeutic value in the treatment of liver cancer.

Wei Gan, Mei-Xia Zhang, Jin-Long Huang, Pei-Yun Zhou, Cheng Zhou, Gao Liu, Yi-Peng Fu, Bao-Ye Sun, Chu-Yu Jing, Ruo-Yu Guan, Zhu-Tao Wang, Jian Zhou, Jia Fan, Yong Yi, Shuang-Jian Qiu. 2020.

Background Deltex1 (DTX1) was found to play its role in the development of several kinds of cancer. The association between DTX1 and breast cancer was unclear. We aimed to investigate the association between DTX1 expression and clinical characteristics of breast cancer, further explore the possible mechanisms of DTX1 on the development of breast cancer. Methods We determined level of DTX1 expression by qRT-PCR, analyzed association between DTX1 and clinical characteristics of breast cancer by student’s test and ANOVA test. The possible mechanisms of DTX1 on the development of breast cancer were explored with breast cancer cell lines in vitro. Results Levels of DTX1 in breast cancer tissues were lower compared to FCD tissues and peri-neoplastic breast tissues (P<0.01). Lower expression of DTX1 was associated with advanced tumor grade (grade III, P=0.002), advanced clinical TNM stage (III-IV stage, P=0.017), positive lymph node metastasis (P=0.034) and high Ki-67 index (P=0.031). Multivariate Cox regression analysis revealed that DTX1 expression was recognized as an independent prognostic factor for MFS in breast cancer. Elevated levels of Notch1, Jagged1 and HES1 in NOTCH pathway and p-Akt/PKB in PI3K/AKT pathway were found in breast cancer cells with lower DTX1 expression. GSI treatment could inhibit breast cancer cell proliferation and migration through NOTCH/DTX1/PI3K/AKT pathways. Conclusion Lower DTX1 in breast tissues was associated with advanced condition, prognosis and metastasis of breast cancer. Lower DTX1 might promote breast cancer cell proliferation and migration via NOTCH/DTX1/PI3K/AKT pathways. DTX1 might be useful as a marker to select new therapy for breast cancer.

Xiaoyi Liu, Jianxia Hu, Kui Che, Jingwei Chi, Zhengju Fu, Xiangping Liu, haibo wang. 2020.

The extent to which differentiated cells, while remaining in their native microenvironment, can be reprogrammed to assume a different identity will reveal fundamental insight into cellular plasticity and impact regenerative medicine. To investigate in vivo cell lineage potential, we leveraged the zebrafish as a practical vertebrate platform to determine factors and mechanisms necessary to induce differentiated cells of one germ layer to adopt the lineage of another. We discovered that ectopic co-expression of Sox32 and Oct4 in several non-endoderm lineages, including skeletal muscle, can specifically trigger an early endoderm genetic program in a cell-autonomous manner. Gene expression, live imaging, and functional studies reveal that the endoderm-induced muscle cells lose muscle gene expression and morphology, while specifically gaining endoderm organogenesis lineage markers, such as the pancreatic specification genes, hhex and ptf1a, via a mechanism resembling normal development. Endoderm induction by a pluripotent defective form of Oct4, endoderm markers appearing prior to loss of muscle cell morphology, and a lack of mesoderm, ectoderm, dedifferentiation, and pluripotency gene activation, together, suggests that reprogramming is endoderm specific and occurs via direct transdifferentiation. Our work demonstrates that within a living vertebrate animal, differentiated cells can be induced to directly adopt the identity of a completely unrelated cell lineage, while remaining in a distinct microenvironment, suggesting that differentiated cells in vivo may be more amenable to lineage conversion than previously appreciated. This discovery of extensive lineage potential of differentiated cells, in vivo, challenges our understanding of cell lineage restriction and may pave the way towards new in vivo sources of replacement cells for degenerative diseases such as diabetes.

P. Duc Dong, Joseph Lancman, Clyde Campbell, Raquel Espin-Palazon, Jonatan Matalonga, Jiaye He, Alyssa Graves, Rashmi Mishra, Jun Yin, Chengjian Zhao, Xin-Xin Zeng, Jan Huisken, David Traver. 2020.

miRNAs are small, non-coding RNAs that regulate gene expression post-transcriptionally. We used small RNA sequencing to identify tissue-specific miRNAs in the adult brain, thorax, gut, and fat body of Drosophila melanogaster. One of the most brain-specific miRNAs that we identified was miR-210, an evolutionarily highly conserved miRNA implicated in the regulation of hypoxia in mammals. In Drosophila, we show that miR-210 is specifically expressed in sensory organs, including photoreceptors. miR-210 knockout mutants are not sensitive toward hypoxia but show progressive degradation of photoreceptor cells, accompanied by decreased photoreceptor potential, demonstrating an important function of miR-210 in photoreceptor maintenance and survival.

Carina M Weigelt, Oliver Hahn, Katharina Arlt, Matthias Gruhn, Annika J Jahn, Jacqueline Eßer, Jennifer A Werner, Corinna Klein, Ansgar Büschges, Sebastian Grönke, Linda Partridge. Life Science Alliance, 2 (1), e201800149, 2019.

Pulpitis is a frequent bacterially driven inflammation featured with the local accumulation of inflammatory products in human dental pulps. A GEO dataset GSE16134 comprising data of inflamed dental pulp tissues was used for bioinformatics analyses. A protein-protein interaction (PPI) analysis suggested that chemokine receptor 4 (CXCR4) owned a high correlation with platelet endothelial cell adhesion molecule-1 (PECAM1). A rat model with pulpitis was established, and lipopolysaccharide (LPS)-induced human dental pulp fibroblasts (HDPFs) were used for in vitro experiments. Then, high expression of PECAM1 and CXCR4 was validated in the inflamed dental pulp tissues in rats and in LPS-induced HDPFs. Either downregulation of PECAM1 or CXCR4 suppressed inflammatory cell infiltration in inflamed tissues as well as the inflammation and apoptosis of HDPFs. A transcription factor myocyte-enhancer factor 2 (MEF2C) was predicted and validated as a positive regulator of either PECAM1 or CXCR4, which activated the NF-κB signaling pathway and promoted pulpitis progression. To sum up, this study suggested that MEF2C transcriptionally activates PECAM1 and CXCR4 to activate the B-cell and NF-κB signaling pathways, leading to inflammatory cell infiltration and pulpitis progression.

Yonghong Liu, Zhiyong Zhang, Wenjing Li, Songbo Tian. Frontiers in Cell and Developmental Biology, 8, 2020.

Nuclear receptor SET domain protein (NSD2) plays a fundamental role in the pathogenesis of Wolf–Hirschhorn Syndrome (WHS) and is overexpressed in multiple human myelomas, but its protein–protein interaction (PPI) patterns, particularly at the isoform/exon levels, are poorly understood. We explored the subcellular localizations of four representative NSD2 transcripts with immunofluorescence microscopy. Next, we used label-free quantification to perform immunoprecipitation mass spectrometry (IP-MS) analyses of the transcripts. Using the interaction partners for each transcript detected in the IP-MS results, we identified 890 isoform-specific PPI partners (83% are novel). These PPI networks were further divided into four categories of the exon-specific interactome. In these exon-specific PPI partners, two genes, RPL10 and HSPA8, were successfully confirmed by co-immunoprecipitation and Western blotting. RPL10 primarily interacted with Isoforms 1, 3, and 5, and HSPA8 interacted with all four isoforms, respectively. Using our extended NSD2 protein interactions, we constructed an isoform-level PPI landscape for NSD2 to serve as reference interactome data for NSD2 spliceosome-level studies. Furthermore, the RNA splicing processes supported by these isoform partners shed light on the diverse roles NSD2 plays in WHS and myeloma development. We also validated the interactions using Western blotting, RPL10, and the three NSD2 (Isoform 1, 3, and 5). Our results expand gene-level NSD2 PPI networks and provide a basis for the treatment of NSD2-related developmental diseases.

Weidi Wang, Yucan Chen, Jingjing Zhao, Liang Chen, Weichen Song, Li Li, Guan Ning Lin. Frontiers in Cell and Developmental Biology, 9, 2021.

Aging-associated chronic inflammation is a key contributing factor to a cluster of chronic metabolic disorders, such as cardiovascular disease, obesity, and type 2 diabetes. Immune cells particularly T cells accumulate in adipose tissue with advancing age, and there exists a cross talk between T cell and preadipocyte, contributing to age-related adipose tissue remodeling. Here, we compared the difference in morphology and function of adipose tissue between young (3-month-old) and old (18-month-old) mice and showed the phenomenon of brown adipose tissue (BAT) “whitening” in old mice. Flow cytometry analysis suggested an increased proportion of T cells in BAT of old mice comparing with the young and exhibited senescent characteristics. We take advantage of coculture system to demonstrate directly that senescent T cells inhibited brown adipocyte differentiation of preadipocytes in adipose tissue. Mechanistically, both in vitro and in vivo studies suggested that senescent T cells produced and released a higher level of IFN-γ, which plays a critical role in inhibition of preadipocyte-to-brown adipocyte differentiation. Taken together, the data indicate that senescent T cell-derived IFN-γ is a key regulator in brown adipocyte differentiation.

Xiao-Xi Pan, Kang-Li Yao, Yong-Feng Yang, Qian Ge, Run Zhang, Ping-Jin Gao, Cheng-Chao Ruan, Fang Wu. Frontiers in Cell and Developmental Biology, 9, 2021.

There is a growing body of evidence which suggests that intestinal microbiota, especially Fusobacterium nucleatum (F. nucleatum), are associated with intestinal immune disease such as ulcerative colitis (UC). The mechanism by which F. nucleatum promotes intestinal epithelial cell (IEC) death remained undefined. Here, we investigated the potential mechanisms about how F. nucleatum aggravates IEC death in UC. We first detected the abundance of F. nucleatum in UC tissues and analyzed its relationship with the clinical characteristics of UC. Next, we explored whether F. nucleatum promotes intestinal epithelial cell death in vitro and in vivo. Furthermore, we extracted lipopolysaccharide (LPS) of the F. nucleatum and examined whether F. nucleatum exacerbates UC via LPS. Our results indicated that F. nucleatum was abundant in UC tissues and was correlated with clinical characteristics. In addition, we demonstrated that F. nucleatum and its LPS aggravated IEC death by promoted IEC autophagy. Furthermore, autophagy inhibitors, chloroquine (CQ), 3-methyladenine (3-MA) or Atg5 silencing prevented IEC death mediated by F. nucleatum, which suggests F. nucleatum may contribute to UC by activating autophagic cell death. All our results uncover a vital role of F. nucleatum in autophagic cell death and UC, giving rise to a new sight for UC therapy by inhibiting excessive IEC autophagy and autophagic cell death.

Wenhao Su, Yongyu Chen, Pan Cao, Yan Chen, Yuanmei Guo, Siwei Wang, Weiguo Dong. Frontiers in Cellular and Infection Microbiology, 10, 2020.

Cardiac remodeling consisted of ventricular hypertrophy and interstitial fibrosis is the pathological process of many heart diseases. Fibroblasts as one of the major cells in the myocardium regulate the balance of the generation and degeneration of collagen, and these cells transform toward myofibroblasts in pathological state, contributing to the remodeling of the heart. Peroxisome proliferator-activated receptor-γ (PPAR-γ) coactivator-1α (PGC-1α) is vital to the function of mitochondria, which contributes to the energy production and reactive oxidative species (ROS)-scavenging activity in the heart. In this study, we found that fibroblast-specific PGC-1α KO induced cardiac remodeling especially fibrosis, and Angiotensin II (AngII) aggravated cardiac fibrosis, accompanied with a high level of oxidative stress response and inflammation.

Hong-jin Chen, Xiao-xi Pan, Li-li-qiang Ding, Cheng-chao Ruan, Ping-jin Gao. Frontiers in Cardiovascular Medicine, 8, 2021.

To examine the effect and mechanism of thyroid hormone on gonadal sex differentiation, Takifugu rubripes larvae were treated with goitrogen (methimazole, MET, 1000 μg/g), and thyroxine (T4, 2nM) from 25 to 80 days after hatching (dah). Gonadal histology and sex ratios of fish were then determined at 80 dah. MET treatment induced masculinization, but T4 treatment did not induce feminization in T. rubripes larvae. Transcriptomic analysis of gonads at 80 dah was then conducted. Among the large number of differentially expressed genes between the groups, the expression of foxl2, cyp19a1a, and dmrt1 was altered. The expression of foxl2, cyp19a1a, dmrt1 and gsdf at 25, 40, 55 days after treatment (dat) was further analyzed by qPCR. MET treatment suppressed the expression of foxl2 and cyp19a1a, and induced the expression of dmrt1 in genetic females (p &lt; 0.05). Additionally, T4 treatment induced an increase in the expression of cyp19a1a in genetic XY gonads only at 25 dat. However, the increase in cyp19a1a expression did not continue to 40 and 55 dat. This may explain why feminization of larvae was not found in the T4-treated group. Thus, the present study provides the first evidence that MET treatment causes masculinization in teleost fish. The effects of MET-induced masculinization in T. rubripes may act primarily via suppression of the expression of foxl2 and cyp19a1a, and stimulation of the expression of dmrt1. Moreover, the effects of higher concentrations of T4 or different concentrations of T3, on sex differentiation require further testing.

Zhen Yuan, Xufang Shen, Hongwei Yan, Jieming Jiang, Binwei Liu, Lei Zhang, Yumeng Wu, Ying Liu, Qi Liu. Frontiers in Endocrinology, 12, 2021.