scholarly journals Arabidopsis Sucrose Transporter 4 (AtSUC4) is Involved in Root Response of High Content Sucrose-Growth Via IAA- and ABA- Dependent Manner

Author(s):  
Si-Wen Liu ◽  
Li-Ding Zhang ◽  
Jia-Yu Gao ◽  
Tian-Tian Dong ◽  
Tong Zhang ◽  
...  

Abstract Source-to-sink transport of sucrose mediated by sucrose transporters (SUCs) is one of the major determinants of plant growth. However, the role of AtSUC4, the only member of Group IV sucrose transporter in Arabidopsis, was undervalued in sink organ during seedling period. In our study, the primary root length of the atsuc4 mutants was significantly longer than that of the wild-type (WT) under exogenous 4% and 6% sucrose treatment. But this phenotype could not be imitated by external application of glucose or mannitol. It means that the atsuc4 mutants were insensitive to high sucrose stress compared with WT. Meanwhile, HPLC-MS/MS results showed that the root of atsuc4 mutants accumulated less sucrose and ABA and more IAA content compared with WT on 4% and 6% sucrose supplementation. Transcriptome analysis showed that many key genes involved in IAA and ABA signals were respective stimulated and repressed in the atsuc4 mutants, respectively. Taken together, we concluded that the deficiency of AtSUC4, not only reducing the transported and uptaked of sucrose, but also as a signal, may be collaborated with IAA and ABA to regulate root growth under high sucrose stress. This study confirmed the new function of AtSUC4, and provided an promising candidate gene for improving tolerance to high sucrose stress.

2020 ◽  
Vol 117 (11) ◽  
pp. 6223-6230 ◽  
Author(s):  
Qiyu Xu ◽  
Shijiao Yin ◽  
Yue Ma ◽  
Min Song ◽  
Yingjie Song ◽  
...  

All multicellular organisms keep a balance between sink and source activities by controlling nutrient transport at strategic positions. In most plants, photosynthetically produced sucrose is the predominant carbon and energy source, whose transport from leaves to carbon sink organs depends on sucrose transporters. In the model plantArabidopsis thaliana, transport of sucrose into the phloem vascular tissue by SUCROSE TRANSPORTER 2 (SUC2) sets the rate of carbon export from source leaves, just like the SUC2 homologs of most crop plants. Despite their importance, little is known about the proteins that regulate these sucrose transporters. Here, identification and characterization of SUC2-interaction partners revealed that SUC2 activity is regulated via its protein turnover rate and phosphorylation state. UBIQUITIN-CONJUGATING ENZYME 34 (UBC34) was found to trigger turnover of SUC2 in a light-dependent manner. The E2 enzyme UBC34 could ubiquitinate SUC2 in vitro, a function generally associated with E3 ubiquitin ligases.ubc34mutants showed increased phloem loading, as well as increased biomass and yield. In contrast, mutants of another SUC2-interaction partner, WALL-ASSOCIATED KINASE LIKE 8 (WAKL8), showed decreased phloem loading and growth. An in vivo assay based on a fluorescent sucrose analog confirmed that SUC2 phosphorylation by WAKL8 can increase transport activity. Both proteins are required for the up-regulation of phloem loading in response to increased light intensity. The molecular mechanism of SUC2 regulation elucidated here provides promising targets for the biotechnological enhancement of source strength.


2019 ◽  
Vol 17 (4) ◽  
pp. 426-431
Author(s):  
Jin Xuezhu ◽  
Li Jitong ◽  
Nie Leigang ◽  
Xue Junlai

The main purpose of this study is to investigate the role of citrus leaf extract in carbon tetrachloride-induced hepatic injury and its potential molecular mechanism. Carbon tetrachloride was used to construct hepatic injury animal model. To this end, rats were randomly divided into 4 groups: control, carbon tetrachloride-treated, and two carbon tetrachloride + citrus leaf extract-treated groups. The results show that citrus leaf extract treatment significantly reversed the effects of carbon tetrachloride on the body weight changes and liver index. Besides, treatment with citrus leaf extract also reduced the levels of serum liver enzymes and oxidative stress in a dose-dependent manner. H&E staining and western blotting suggested that citrus leaf extract could repair liver histological damage by regulating AMPK and Nrf-2.


Author(s):  
Ranjit Singh ◽  
Upasana Priya ◽  
Mahesh Chand Purvya

In today’s busy and fast life more people are living with conditions that increase their susceptibility to traumatic wounds, due to one or the other cause; thereby taking a heavy toll of life. As per Ayurveda, these type of wounds, which are caused by extrinsic factors are known as Sadyovrana. The major aspect of the management of the traumatic wounds is prevention of the infection, speedy healing, reducing pain, discharge and less discoloration after healing. In Ayurveda, various formulations for debridement are mentioned such as Kwaatha, Kalka, Churna, Rasakriya, Varti, Taila and Ghrita depending on the Avastha of Vrana. In the present study use of Vajraka Taila for external application, has been chosen. Total 30 patients fulfilling the inclusion criteria were selected and the treatment was given for 15 days. The study showed that Vajraka Taila is very effective in Vrana.


1999 ◽  
Vol 73 (6) ◽  
pp. 4575-4581 ◽  
Author(s):  
Masahiko Makino ◽  
Satoshi Shimokubo ◽  
Shin-Ichi Wakamatsu ◽  
Shuji Izumo ◽  
Masanori Baba

ABSTRACT The development of human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is closely associated with the activation of T cells which are HTLV-1 specific but may cross-react with neural antigens (Ags). Immature dendritic cells (DCs), differentiated from normal donor monocytes by using recombinant granulocyte-macrophage colony-stimulating factor and recombinant interleukin-4, were pulsed with HTLV-1 in vitro. The pulsed DCs contained HTLV-1 proviral DNA and expressed HTLV-1 Gag Ag on their surface 6 days after infection. The DCs matured by lipopolysaccharides stimulated autologous CD4+ T cells and CD8+ T cells in a viral dose-dependent manner. However, the proliferation level of CD4+ T cells was five- to sixfold higher than that of CD8+ T cells. In contrast to virus-infected DCs, DCs pulsed with heat-inactivated virions activated only CD4+ T cells. To clarify the role of DCs in HAM/TSP development, monocytes from patients were cultured for 4 days in the presence of the cytokines. The expression of CD86 Ag on DCs was higher and that of CD1a Ag was more down-regulated than in DCs generated from normal monocytes. DCs from two of five patients expressed HTLV-1 Gag Ag. Furthermore, both CD4+ and CD8+ T cells from the patients were greatly stimulated by contact with autologous DCs pulsed with inactivated viral Ag as well as HTLV-1-infected DCs. These results suggest that DCs are susceptible to HTLV-1 infection and that their cognate interaction with T cells may contribute to the development of HAM/TSP.


Author(s):  
Tatsuro Saruga ◽  
Tadaatsu Imaizumi ◽  
Shogo Kawaguchi ◽  
Kazuhiko Seya ◽  
Tomoh Matsumiya ◽  
...  

AbstractC-X-C motif chemokine 10 (CXCL10) is an inflammatory chemokine and a key molecule in the pathogenesis of rheumatoid arthritis (RA). Melanoma differentiation-associated gene 5 (MDA5) is an RNA helicase that plays a role in innate immune and inflammatory reactions. The details of the regulatory mechanisms of CXCL10 production and the precise role of MDA5 in RA synovitis have not been fully elucidated. The aim of this study was to examine the role of MDA5 in regulating CXCL10 expression in cultured human rheumatoid fibroblast-like synoviocytes (RFLS). RFLS was stimulated with Toll-like receptor 3 (TLR3) ligand polyinosinic:polycytidylic acid (poly I:C), a synthetic double-stranded RNA mimetic. Expression of interferon beta (IFN-β), MDA5, and CXCL10 was measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, and enzyme-linked immunosorbent assay. A neutralizing antibody of IFN-β and siRNA-mediated MDA5 knockdown were used to determine the role of these molecules in regulating CXCL10 expression downstream of TLR3 signaling in RFLS. Poly I:C induced IFN-β, MDA5, and CXCL10 expression in a concentration- and time-dependent manner. IFN-β neutralizing antibody suppressed the expression of MDA5 and CXCL10, and knockdown of MDA5 decreased a part of CXCL10 expression (p < 0.001). The TLR3/IFN-β/CXCL10 axis may play a crucial role in the inflammatory responses in RA synovium, and MDA5 may be partially involved in this axis.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Dasol Kim ◽  
Hui-Yun Hwang ◽  
Eun Sun Ji ◽  
Jin Young Kim ◽  
Jong Shin Yoo ◽  
...  

AbstractDisorders of autophagy, a key regulator of cellular homeostasis, cause a number of human diseases. Due to the role of autophagy in metabolic dysregulation, there is a need to identify autophagy regulators as therapeutic targets. To address this need, we conducted an autophagy phenotype-based screen and identified the natural compound kaempferide (Kaem) as an autophagy enhancer. Kaem promoted autophagy through translocation of transcription factor EB (TFEB) without MTOR perturbation, suggesting it is safe for administration. Moreover, Kaem accelerated lipid droplet degradation in a lysosomal activity-dependent manner in vitro and ameliorated metabolic dysregulation in a diet-induced obesity mouse model. To elucidate the mechanism underlying Kaem’s biological activity, the target protein was identified via combined drug affinity responsive target stability and LC–MS/MS analyses. Kaem directly interacted with the mitochondrial elongation factor TUFM, and TUFM absence reversed Kaem-induced autophagy and lipid degradation. Kaem also induced mitochondrial reactive oxygen species (mtROS) to sequentially promote lysosomal Ca2+ efflux, TFEB translocation and autophagy induction, suggesting a role of TUFM in mtROS regulation. Collectively, these results demonstrate that Kaem is a potential therapeutic candidate/chemical tool for treating metabolic dysregulation and reveal a role for TUFM in autophagy for metabolic regulation with lipid overload.


Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1802
Author(s):  
Nayoung Kim ◽  
Mi Yeon Kim ◽  
Woo Seon Choi ◽  
Eunbi Yi ◽  
Hyo Jung Lee ◽  
...  

Natural killer (NK) cells are innate cytotoxic lymphocytes that provide early protection against cancer. NK cell cytotoxicity against cancer cells is triggered by multiple activating receptors that recognize specific ligands expressed on target cells. We previously demonstrated that glycogen synthase kinase (GSK)-3β, but not GSK-3α, is a negative regulator of NK cell functions via diverse activating receptors, including NKG2D and NKp30. However, the role of GSK-3 isoforms in the regulation of specific ligands on target cells is poorly understood, which remains a challenge limiting GSK-3 targeting for NK cell-based therapy. Here, we demonstrate that GSK-3α rather than GSK-3β is the primary isoform restraining the expression of NKG2D ligands, particularly ULBP2/5/6, on tumor cells, thereby regulating their susceptibility to NK cells. GSK-3α also regulated the expression of the NKp30 ligand B7-H6, but not the DNAM-1 ligands PVR or nectin-2. This regulation occurred independently of BCR-ABL1 mutation that confers tyrosine kinase inhibitor (TKI) resistance. Mechanistically, an increase in PI3K/Akt signaling in concert with c-Myc was required for ligand upregulation in response to GSK-3α inhibition. Importantly, GSK-3α inhibition improved cancer surveillance by human NK cells in vivo. Collectively, our results highlight the distinct role of GSK-3 isoforms in the regulation of NK cell reactivity against target cells and suggest that GSK-3α modulation could be used to enhance tumor cell susceptibility to NK cells in an NKG2D- and NKp30-dependent manner.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Zhang ◽  
Guoyu Yin ◽  
Heping Zhao ◽  
Hanzhi Ling ◽  
Zhen Xie ◽  
...  

AbstractIn inflamed joints, enhanced hyaluronic acid (HA) degradation is closely related to the pathogenesis of rheumatoid arthritis (RA). KIAA1199 has been identified as a hyaladherin that mediates the intracellular degradation of HA, but its extracellular function remains unclear. In this study, we found that the serum and synovial levels of secreted KIAA1199 (sKIAA1199) and low-molecular-weight HA (LMW-HA, MW < 100 kDa) in RA patients were significantly increased, and the positive correlation between them was shown for the first time. Of note, treatment with anti-KIAA1199 mAb effectively alleviated the severity of arthritis and reduced serum LMW-HA levels and cytokine secretion in collagen-induced arthritis (CIA) mice. In vitro, sKIAA1199 was shown to mediate exogenous HA degradation by attaching to the cell membrane of RA fibroblast-like synoviosytes (RA FLS). Furthermore, the HA-degrading activity of sKIAA1199 depended largely on its adhesion to the membrane, which was achieved by its G8 domain binding to ANXA1. In vivo, kiaa1199-KO mice exhibited greater resistance to collagen-induced arthritis. Interestingly, this resistance could be partially reversed by intra-articular injection of vectors encoding full-length KIAA1199 instead of G8-deleted KIAA119 mutant, which further confirmed the indispensable role of G8 domain in KIAA1199 involvement in RA pathological processes. Mechanically, the activation of NF-κB by interleukin-6 (IL-6) through PI3K/Akt signaling is suggested to be the main pathway to induce KIAA1199 expression in RA FLS. In conclusion, our study supported the contribution of sKIAA1199 to RA pathogenesis, providing a new therapeutic target for RA by blocking sKIAA1199-mediated HA degradation.


Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 420
Author(s):  
Su-Jung Hwang ◽  
Ye-Seul Song ◽  
Hyo-Jong Lee

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.


2021 ◽  
Vol 20 ◽  
pp. 153473542110316
Author(s):  
Liang Wang ◽  
Lei Xu ◽  
Yu Wang

Cutaneous squamous cell carcinoma (CSCC) is a malignant tumor that originates from keratinocytes in the epidermis or appendage. Traditional Chinese medicine Huaier has anti-tumor activity in various malignancies. Little is known about the role of Huaier in CSCC. Here, we investigated the function of Huaier in CSCC. We treated CSCC cell line (SCL-1 and A431) with a series of concentration gradients of Huaier to examine the half maximal inhibitory concentration (IC50) of Huaier on SCL-1 and A431 cells. The IC50 of Huaier on growth of SCL-1 and A431 cells were 6.96 and 7.57 mg/mL, respectively. Moreover, Huaier reduced the methylation levels of CDKN2A and TP53, and enhanced the expression of CDKN2A and TP53 in SCL-1 and A431 cells in a dosage-dependent manner. The expression of DNA methyltransferase DNMT1 was severely repressed by Huaier treatment in SCL-1 and A431 cells. DNMT1 overexpression enhanced the methylation levels of CDKN2A and TP53, and suppressed the expression of CDKN2A and TP53 in Huaier-treated SCL-1 and A431 cells. Huaier treatment inhibited proliferation, migration, and invasion of SCL-1 and A431 cells. However, inhibition of CDKN2A or TP53 reversed the influence of Huaier treatment on proliferation, migration, and invasion of CSCC cells. In conclusion, our data demonstrate that Huaier inhibits proliferation, migration, and invasion of CSCC cells by regulating DNA methylation of CDKN2A and TP53, thereby attenuating the progression of CSCC. Thus, Huaier extract may act as a drug for treating CSCC.


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