RRV-induced biliary atresia in neonatal mice involves CD8 + T lymphocyte killer cells and the Notch signaling pathway

Si Xinmin,Chen Ji,Huang Lei 한국유전학회 2021 Genes & Genomics Vol.43 No.11

Background Persistent infammation induced by viral infection may contribute to the pathogenesis of biliary atresia (BA). Moreover, CD4+ helper cells and CD8+ killer cells are the main efector cells involved in BA and intrahepatic bile duct injuries. Objective Thus, we aimed to explore the dynamics of infammatory cell infltration and infammation-regulated pathways in liver-specifc infammatory responses. Methods Neonatal Balb/C mice were intraperitoneally infected with 1× 106 PFU rhesus rotavirus (RRV; BA+group), 1× 105 PFU RRV (BA- group), or DMEM (control group). Mice were sacrifced 7 or 14 days post-infection and their bile ducts, livers, and spleen-derived tissues were examined via H & E staining. The number of CD4+T lymphocytes helper cells (CD4+Th), CD8+T lymphocytes killer cells (CD8+Tc), natural killer (NK) cells, and macrophages (Mac) in the liver and spleen were quantifed by fow cytometry. The expression of infammatory genes was analyzed via a PCR-array. Western blotting was conducted to quantify the protein expression of Notch receptor active fragments (NICD). Finally, some mice were injected with DAPT (a γ-secretase inhibitor) 12 h post-infection followed by analysis of liver and bile duct tissues after 14 days. Results The numbers of CD4+Th cells were increased in the livers of BA- mice after 14 days (P<0.05). After RRV infection, the number of CD8+Tc, CD4+Th, NK, and Mac were increased in the livers of BA+mice after 7 and 14 days. Notably, NK cell numbers remained elevated in the BA+group, but the number of Mac frst increased and then decreased in both the treatment groups. PCR-array analyses indicated that the expression of many genes related to T cell proliferation and diferentiation signifcantly increased in the livers of BA. The most upregulated gene was Jagged2 (20.34-fold). Increased NICD (Notch receptor active fragments) protein expression was found in the BA +group. Finally, DAPT injection could reduce infammation, CD8+Tc infltration, NICD expression, and bile duct damage after RRV infection. We found that CD8+Tc played the most important role in damaging bile ducts and promoting BA. Conclusion The DAPT-based intervention could reduce expression of CD8+Tc and bile duct damage in BA mouse livers post-RRV infection. We believe that the Notch signaling pathway regulates CD8+Tc functions and infammatory dynamics in BA mouse livers.

Characterization and expression analysis of BcAMT1;4, an ammonium transporter gene in flowering Chinese cabbage

Lihua Zhong,Xinmin Huang,Yunna Zhu,Erfeng Kou,Houcheng Liu,Guangwen Sun,Riyuan Chen,Shiwei Song 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.4

Ammonium (NH 4+ ) is generated during many endogenous metabolic processes in the leaves of plants, and there is increasing evidence that ammonium transporters (AMTs) play important roles in NH 4 + transmembrane transport and distribution. However, the expression of diff erent AMT genes is tissue-type specifi c and their functions diff er. Information about AMT genes and their expression under diff erent environmental conditions in fl owering Chinese cabbage ( Brassica campestris L.) is currently limited. Here, we isolated and characterized an AMT gene, BcAMT1;4 , in fl owering Chinese cabbage. BcAMT1;4 was localized to the plasma membrane and complemented NH 4+ transport in NH 4+ uptake-defi cient yeast. The highest expression levels of BcAMT1;4 were detected in the fl owers and leaves of fl owering Chinese cabbage. The expression of BcAMT1;4 was induced by nitrogen defi ciency and signifi cantly inhibited by the reapplication of NH 4+ (NH 4 Cl or NH 4 NO 3 ). In contrast, when plants pre-cultured in nitrate were transferred to an NH 4+ nutrient solution, BcAMT1;4 expression was signifi cantly enhanced. BcAMT1;4 exhibited a diurnal expression pattern, with higher expression levels during the light period than during the dark period, and a peak expression at the later stage of the light period. Knowledge of AMT genes in fl owering Chinese cabbage will lay a foundation for enhancing our understanding of the functional roles of diff erent AMT members in the regulation of its growth by NH 4+ , as BcAMT1;4 seems to play an important role in leaf NH 4+ transport.

Cloning and Characterization of the Ammonium Transporter Genes BaAMT1;1 and BaAMT1;3 from Chinese Kale

Shiwei Song,Riyuan Chen,Zhenhua He,Xinmin Huang,Lihua Zhong,Houcheng Liu,Guangwen Sun 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.2

Chinese kale (Brassica alboglabra L.) is a popular vegetable rich in important nutrients. Fertilization withappropriate ammonium:nitrate ratios enhances biomass production and quality. AMT-type ammonium transporters havebeen shown to mediate ammonium uptake across the plasma membrane. However, very little is known about themolecular regulation of growth and development by ammonium in Chinese kale, including how ammonium regulatesthe expression of AMT1 genes. In this study, we identified and characterized two AMT1 genes from B. alboglabra,BaAMT1;1 and BaAMT1;3. The full-length open reading frames of BaAMT1;1 and BaAMT1;3 were 1512 bp and1515 bp, respectively. Transient expression of the fusion proteins pBE-EGFP-BaAMT1;1 and pBE-EGFP-BaAMT1;3 inonion epidermal cells indicated that these transporters are located on the plasma membrane. BaAMT1;1 and BaAMT1;3were functional in yeast and complemented a mutant defective in ammonium transport. BaAMT1;1 was expressed invegetative organs and at high levels in roots, while BaAMT1;3 expression was root specific. In addition, we observedopposite responses of BaAMT1;1 and BaAMT1;3 expression to nitrogen starvation and ammonium resupply in roots. These results provide new insights into the molecular mechanisms underlying ammonium absorption in Chinese kale.

A Derivative of Chrysin Suppresses Two-Stage Skin Carcinogenesis by Inhibiting Mitogen- and Stress-Activated Kinase 1

Liu, Haidan,Hwang, Joonsung,Li, Wei,Choi, Tae Woong,Liu, Kangdong,Huang, Zunnan,Jang, Jae-Hyuk,Thimmegowda, N.R.,Lee, Ki Won,Ryoo, In-Ja,Ahn, Jong-Seog,Bode, Ann M.,Zhou, Xinmin,Yang, Yifeng,Erikson, American Association for Cancer Research 2014 CANCER PREVENTION RESEARCH Vol.7 No.1

<P>Mitogen- and stress-activated kinase 1 (MSK1) is a nuclear serine/threonine protein kinase that acts downstream of both extracellular signal-regulated kinases and p38 mitogen-activated protein kinase in response to stress or mitogenic extracellular stimuli. Increasing evidence has shown that MSK1 is closely associated with malignant transformation and cancer development. MSK1 should be an effective target for cancer chemoprevention and chemotherapy. However, very few MSK1 inhibitors, especially natural compounds, have been reported. We used virtual screening of a natural products database and the active conformation of the C-terminal kinase domain of MSK1 (PDB id 3KN) as the receptor structure to identify chrysin and its derivative, compound 69407, as inhibitors of MSK1. Compared with chrysin, compound 69407 more strongly inhibited proliferation and 12-<I>O</I>-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic transformation of JB6 P+ cells with lower cytotoxicity. Western blot data demonstrated that compound 69407 suppressed phosphorylation of the MSK1 downstream effector histone H3 in intact cells. Knocking down the expression of MSK1 effectively reduced the sensitivity of JB6 P+ cells to compound 69407. Moreover, topical treatment with compound 69407 before TPA application significantly reduced papilloma development in terms of number and size in a two-stage mouse skin carcinogenesis model. The reduction in papilloma development was accompanied by the inhibition of histone H3 phosphorylation at Ser10 in tumors extracted from mouse skin. The results indicated that compound 69407 exerts inhibitory effects on skin tumorigenesis by directly binding with MSK1 and attenuates the MSK1/histone H3 signaling pathway, which makes it an ideal chemopreventive agent against skin cancer. <I>Cancer Prev Res; 7(1); 74–85. ©2013 AACR</I>.</P>