• Journal of Life Science
• /
• v.29 no.11
• /
• pp.1281-1293
• /
• 2019

The rhizosphere is the active zone where plant roots communicate with the soil microbiome, each responding to the other's signals. The soil microbiome within the rhizosphere that is beneficial to plant growth and productivity is known as plant growth-promoting rhizobacteria (PGPR). PGPR take part in many pivotal plant processes, including plant growth, development, immunity, and productivity, by influencing acquisition and utilization of nutrient molecules, regulation of phytohormone biosynthesis, signaling, and response, and resistance to biotic- and abiotic-stresses. PGPR also produce secondary compounds and volatile organic compounds (VOCs) that elicit plant growth. Moreover, plant roots exude attractants that cause PGPR to aggregate in the rhizosphere zone for colonization, improving soil properties and protecting plants against pathogenic factors. The interactions between PGPR and plant roots in rhizosphere are essential and interdependent. Many studies have reported that PGPR function in multiple ways under the same or diverse conditions, directly and indirectly. This review focuses on the roles and strategies of PGPR in enhancing nutrient acquisition by nutrient fixation/solubilization/mineralization, inducing plant growth regulators/phytohormones, and promoting growth and development of root and shoot by affecting cell division, elongation, and differentiation. We also summarize the current knowledge of the effects of PGPR and the soil microbiota on plants.

• Molecules and Cells
• /
• v.44 no.1
• /
• pp.38-49
• /
• 2021

Airway mucus secretion is an essential innate immune response for host protection. However, overproduction and hypersecretion of mucus, mainly composed of the gel-forming MUC5AC protein, are significant risk factors for patients with asthma and chronic obstructive pulmonary disease (COPD). The transforming growth factor β (TGFβ) signaling pathway negatively regulates MUC5AC expression; however, the underlying molecular mechanism is not fully understood. Here, we showed that TGFβ significantly reduces the expression of MUC5AC mRNA and its protein in NCI-H292 cells, a human mucoepidermoid carcinoma cell line. This reduced MUC5AC expression was restored by a TGFβ receptor inhibitor (SB431542), but not by the inhibition of NF-κB (BAY11-7082 or Triptolide) or PI3K (LY294002) activities. TGFβ-activated Smad3 dose-dependently bound to MUC5AC promoter. Notably, TGFβ-activated Smad3 recruited HDAC2 and facilitated nuclear translocation of HDAC2, thereby inducing the deacetylation of NF-κB at K310, which is essential for a reduction in NF-κB transcriptional activity. Both TGFβ-induced nuclear translocation of Smad3/HDAC2 and deacetylation of NF-κB at K310 were suppressed by a Smad3 inhibitor (SIS3). These results suggest that the TGFβ-activated Smad3/HDAC2 complex is an essential negative regulator for MUC5AC expression and an epigenetic regulator for NF-κB acetylation. Therefore, these results collectively suggest that modulation of the TGFβ1/Smad3/HDAC2/NF-κB pathway axis can be a promising way to improve lung function as a treatment strategy for asthma and COPD.

• Journal of Life Science
• /
• v.32 no.1
• /
• pp.51-55
• /
• 2022

Matrix metalloproteinase (MMP) enzymes are responsible for the degradation and formation of the extracellular matrix (ECM), and overproduction of MMPs is observed in several diseases, such as cancer and asthma, that progress with metastatic characteristics. Natural products, especially phytochemicals, have been an important source of MMP inhibitors with reduced side effects. Although the majority of phytochemicals inhibit the enzymatic activity of MMPs, some suppress MMP production. In this context, the current study evaluated the potential of Corydalis heterocarpa, a halophyte with reported bioactivities, to inhibit MMP expression in PMA-stimulated HT-1080 cells. A crude C. heterocarpa extract was shown to decrease the mRNA and protein expression of MMP-2 and MMP-9 while increasing the endogenous MMP inhibitors TIMP-1 and TIMP-2 which regulate MMP expression in healthy tissues. In addition, our results show that the inhibitory effects of C. heterocarpa might occur through suppression of the phosphorylation of MAPK signaling, the upstream activator of MMP overexpression. In conclusion, C. heterocarpa is a potential source of antimetastatic compounds that might serve as lead molecules to develop novel MMP inhibitors.

• Journal of Life Science
• /
• v.31 no.11
• /
• pp.980-986
• /
• 2021

Natural products have always been an attractive source in terms of novel anti-metastatic compounds which can hinder MMP expression and activity. Corydalis heterocarpa is a salt marsh plant found in the seashores throughout Korea. Its yellow flowers and spikes have been an ingredient in folk medicine to treat spasm and contractions. The present study assessed the potential of different solvent-based fractions from the crude extract of Corydalis heterocarpa (CHE), a halophyte with reported bioactivities, to suppress the PMA-induced MMP expression in human fibrosarcoma HT-1080 cells. The solvent fractions which were named after the solvent used for fractionation (n-hexane, 85% aqueous (aq.) methanol (MeOH), n-butanol (BuOH), and H₂O were shown to inhibit the both elevated mRNA and protein expression levels of MMP-2 and MMP-9 and simultaneously relieved the suppression on the expression of the endogenous MMP inhibitors TIMP-1 and TIMP-2. Results indicated that the CHE fractions might intervene with the PMA-induced activation of the MAPK signaling which is the upstream activator of MMP overexpression. Among tested samples, 85% aq. MeOH and n-hexane fractions of CHE was determined to be the most active and future studies to isolate the bioactive substances responsible for the regulation of the MMP expression are, therefore, urged. In conclusion, C. heterocarpa was shown to be a potential source of anti-metastatic compounds and n-Hexane and MeOH fractions might yield lead molecules to develop novel MMP inhibitors.

• Research in Plant Disease
• /
• v.28 no.1
• /
• pp.1-18
• /
• 2022

Volatiles exist ubiquitously in nature. Volatile compounds produced by plants and microorganisms confer inter-kingdom and intra-kingdom communications. Autoinducer signaling molecules from contact-based chemical communication, such as bacterial quorum sensing, are relayed through short distances. By contrast, biogenic volatiles derived from plant-microbe interactions generate long-distance (>20 cm) alarm signals for sensing harmful microorganisms. In this review, we discuss prior work on volatile compound-mediated diagnosis of plant diseases, and the use of volatile packaging and dispensing approaches for the biological control of fungi, bacteria, and viruses. In this regard, recent developments on technologies to analyze and detect microbial volatile compounds are introduced. Furthermore, we survey the chemical encapsulation, slow-release, and bio-nano techniques for volatile formulation and delivery that are expected to overcome limitations in the application of biogenic volatiles to modern agriculture. Collectively, technological advances in volatile compound detection, packaging, and delivery provide great potential for the implementation of ecologically-sound plant disease management strategies. We hope that this review will help farmers and young scientists understand the nature of microbial volatile compounds, and shift paradigms on disease diagnosis and management to aromatic (volatile-based) agriculture.

• Journal of Life Science
• /
• v.33 no.1
• /
• pp.73-81
• /
• 2023

In the present study, we prepared hot water extracts and the subsequent organic solvent fractions of methanol extracts of Houttuynia cordata (HC) and Lespedeza cuneata (LC), and investigated their anti-inflammatory effects on lipopolysaccharide-stimulated RAW264.7 cells. Among the treated samples, hexane, chloroform, and ethyl-acetate fractions of HC and LC inhibited nitric oxide (NO) production in a dose-dependent manner, and decreased inducible nitric oxide synthase (iNOS) protein expression. And, we analyzed the flavonoid contents of the ethyl-acetate fraction of HC and LC, and chose apigenin for the further experiments because apigenin was one of flavonoids commonly found in HC and LC. Apigenin dramatically inhibited NO production in a dose-dependent manner without affecting cell viability and decreased iNOS and cyclooxygenase-2 (COX-2) expression. In addition, apigenin suppressed the phosphorylation of p38 and Jun N-terminal kinase (JNK) indicating that apigenin exerts anti-inflammatory activity via the mitogen-activated protein kinase (MAPK) signaling pathway. Subsequently, we conducted RNA-sequencing analysis to detect differentially expressed genes upon apigenin treatment. Among the down-regulated genes, four cytokine genes (interleukin (IL)-1α, IL-1β, IL-6, and colony stimulating factor 2 (CSF2)) were selected for the further analysis, and the reduction of their expression by apigenin was confirmed with quantitative real-time polymerase chain reaction. Overall, our results suggest that Houttuynia cordata and Lespedeza cuneata have the anti-inflammatory effects and apigenin can be the one of key molecules responsible for their anti-inflammatory activities.

• Journal of Life Science
• /
• v.32 no.3
• /
• pp.241-248
• /
• 2022

NF-κB acts as a critical transcription factor in inflammation and innate immunity, and it is also closely involved in cell survival and tumorigenesis via induction of anti-apoptotic genes. In these processes, NF-κB cooperates with multiple other signaling molecules and pathways, and although many studies have demonstrated that Hsp90 regulates NF-κB activity, the exact mechanism is unclear. In this study, we investigated the relationship between Hsp90 and IKKγ in the regulation of NF-κB using expression plasmids of IKK complex components. Wild-type and deletion mutants of IKKγ were expressed together with Hsp90, and the combined regulatory effect of Hsp90 and IKKγ on NF-κB activation was assayed. The results show that Hsp90 activates NF-κB by promoting the phosphorylation and degradation of IκBα and that activation of NF-κB by NIK and LPS was increased by Hsp90. IKKγ elevated the effect of Hsp90 on NF-κB activation by increasing phosphorylation and degradation of IκBα. The positive regulation on NF-κB by Hsp90 and IKKγ was also proved in analysis with IKKβ-EE, the constitutively active form of IKKβ. In experiments with the deletion mutants of IKKγ, the N-terminal IKKβ binding domain, C-terminal leucine zipper, and zinc finger domains of IKKγ were found not necessary for the positive regulation of NF-κB activity. Additionally, the expression of pro-inflammatory cytokines was synergistically elevated by Hsp90 and IKKγ. These results indicate that inhibiting the interaction between Hsp90 and IKKγ is a possible strategic method for controlling NF-κB and related diseases.

• Molecules and Cells
• /
• v.45 no.3
• /
• pp.134-147
• /
• 2022

The anti-oxidant enzyme heme oxygenase-1 (HO-1) is known to exert anti-inflammatory effects. From a library of pyrazolo[3,4-d]pyrimidines, we identified a novel compound KKC080096 that upregulated HO-1 at the mRNA and protein levels in microglial BV-2 cells. KKC080096 exhibited anti-inflammatory effects via suppressing nitric oxide, interleukin1β (IL-1β), and iNOS production in lipopolysaccharide (LPS)-challenged cells. It inhibited the phosphorylation of IKK and MAP kinases (p38, JNK, ERK), which trigger inflammatory signaling, and whose activities are inhibited by HO-1. Further, KKC080096 upregulated anti-inflammatory marker (Arg1, YM1, CD206, IL-10, transforming growth factor-β [TGF-β]) expression. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinetreated mice, KKC080096 lowered microglial activation, protected the nigral dopaminergic neurons, and nigral damage-associated motor deficits. Next, we elucidated the mechanisms by which KKC080096 upregulated HO-1. KKC080096 induced the phosphorylation of AMPK and its known upstream kinases LKB1 and CaMKKbeta, and pharmacological inhibition of AMPK activity reduced the effects of KKC080096 on HO-1 expression and LPS-induced NO generation, suggesting that KKC080096-induced HO-1 upregulation involves LKB1/AMPK and CaMKKbeta/AMPK pathway activation. Further, KKC080096 caused an increase in cellular Nrf2 level, bound to Keap1 (Nrf2 inhibitor protein) with high affinity, and blocked Keap1-Nrf2 interaction. This Nrf2 activation resulted in concurrent induction of HO-1 and other Nrf2-targeted antioxidant enzymes in BV-2 and in dopaminergic CATH.a cells. These results indicate that KKC080096 is a potential therapeutic for oxidative stress-and inflammation-related neurodegenerative disorders such as Parkinson's disease.

• Implantology
• /
• v.18 no.2
• /
• pp.120-138
• /
• 2014

Purpose: The purpose of this study was to review the outcomes of a series of studies on tissue regeneration conducted in multiple institutions including the Department of Periodontology, College of Dentistry, Yonsei University. Materials and Methods: Studies were performed divided into the following three subjects; 1) Development of three-dimensional nano-hydroxyapatite (n-HA) scaffold for facilitating drug release and cell adhesion. 2) Synergistic effects of bone marrow-derived mesenchymal stem cells (BMMSC) application simultaneously with platelet-rich plasma (PRP) on HA scaffolds. 3) The efficacy of silk scaffolds coated with n-HA. Also, all results were analyzed by subjects. Results: Hollow hydroxyapatite spherical granules were found to be a useful tool for the drug release and avidin-biotin binding system for cell attachment. Also, BMMSC simultaneously with PRP applied in an animal bone defect model was seen to be more synergistic than in the control group. But, the efficacy of periodontal ligament cells and dental pulp cells with silk scaffolds could not be confirmed in the initial phase of bone healing. Conclusion: The ideal combination of three elements of tissue engineering-scaffolds, cells and signaling molecules could be substantiated due to further investigations with the potentials and limitations of the suggested list of studies.

• Molecules and Cells
• /
• v.46 no.10
• /
• pp.592-610
• /
• 2023

The Hippo kinase cascade functions as a central hub that relays input from the "outside world" of the cell and translates it into specific cellular responses by regulating the activity of Yes-associated protein 1 (YAP1). How Hippo translates input from the extracellular signals into specific intracellular responses remains unclear. Here, we show that transforming growth factor β (TGFβ)-activated TAK1 activates LATS1/2, which then phosphorylates YAP1. Phosphorylated YAP1 (p-YAP1) associates with RUNX3, but not with TEAD4, to form a TGFβ-stimulated restriction (R)-point-associated complex which activates target chromatin loci in the nucleus. Soon after, p-YAP1 is exported to the cytoplasm. Attenuation of TGFβ signaling results in re-localization of unphosphorylated YAP1 to the nucleus, where it forms a YAP1/TEAD4/SMAD3/AP1/p300 complex. The TGFβ-stimulated spatiotemporal dynamics of YAP1 are abrogated in many cancer cells. These results identify a new pathway that integrates TGFβ signals and the Hippo pathway (TGFβ→TAK1→LATS1/2→YAP1 cascade) with a novel dynamic nuclear role for p-YAP1.