• Journal of Microbiology and Biotechnology
• /
• v.31 no.8
• /
• pp.1115-1122
• /
• 2021

Rotavirus (RV), as the main cause of diarrhea in children under 5 years, contributes to various childhood diseases. Valeriana jatamansi Jones is a traditional Chinese herb and possesses antiviral effects. In this study we investigated the potential mechanisms of V. jatamansi Jones in RV-induced diarrhea. MTT assay was performed to evaluate cell proliferation and the diarrhea mice model was constructed using SA11 infection. Mice were administered V. jatamansi Jones and ribavirin. Diarrhea score was used to evaluate the treatment effect. The enzyme-linked immunosorbent assay was performed to detect the level of cytokines. Western blot and quantitative reverse transcription-PCR were used to determine protein and mRNA levels, respectively. Hematoxylin-eosin staining was applied to detect the pathological change of the small intestine. TdT-mediated dUTP nick-end labeling was conducted to determine the apoptosis rate. The results showed V. jatamansi Jones promoted MA104 proliferation. V. jatamansi Jones downregulated phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT) in protein level, which was consistent with the immunohistochemistry results. Moreover, V. jatamansi Jones combined with ribavirin regulated interleukin-1β (IL-1β), interferon γ, IL-6, tumor necrosis factor α, and IL-10, and suppressed secretory immunoglobulin A secretion to remove viruses and inhibit dehydration. V. jatamansi Jones + ribavirin facilitated the apoptosis of small intestine cells. In conclusion, V. jatamansi Jones may inhibit RV-induced diarrhea through PI3K/AKT signaling pathway, and could therefore be a potential therapy for diarrhea.

• Nutrition Research and Practice
• /
• v.16 no.2
• /
• pp.147-160
• /
• 2022

BACKGROUND/OBJECTIVES: Patients with chronic kidney disease (CKD) have a high concentration of uremic toxins in their blood and often experience muscle atrophy. Indoxyl sulfate (IS) is a uremic toxin produced by tryptophan metabolism. Although an elevated IS level may induce muscle dysfunction, the effect of IS on physiological concentration has not been elucidated. Additionally, the effects of ursolic acid (UA) on muscle hypertrophy have been reported in healthy models; however, it is unclear whether UA ameliorates muscle dysfunction associated with chronic diseases, such as CKD. Thus, this study aimed to investigate whether UA can improve the IS-induced impairment of mitochondrial biogenesis. MATERIALS/METHODS: C2C12 cells were incubated with or without IS (0.1 mM) and UA (1 or 2 μM) to elucidate the physiological effect of UA on CKD-related mitochondrial dysfunction and its related mechanisms using real-time reverse transcription-polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay. RESULTS: IS suppressed the expression of differentiation marker genes without decreasing cell viability. IS decreased the mitochondrial DNA copy number and ATP levels by downregulating the genes pertaining to mitochondrial biogenesis (Ppargc1a, Nrf1, Tfam, Sirt1, and Mef2c), fusion (Mfn1 and Mfn2), oxidative phosphorylation (Cycs and Atp5b), and fatty acid oxidation (Pdk4, Acadm, Cpt1b, and Cd36). Furthermore, IS increased the intracellular mRNA and secretory protein levels of interleukin (IL)-6. Finally, UA ameliorated the IS-induced impairment in C2C12 cells. CONCLUSIONS: Our results indicated that UA improves the IS-induced impairment of mitochondrial biogenesis by affecting differentiation, ATP levels, and IL-6 secretion in C2C12 cells. Therefore, UA could be a novel therapeutic agent for CKD-induced muscle dysfunction.

• The Korean Journal of Physiology and Pharmacology
• /
• v.28 no.5
• /
• pp.435-447
• /
• 2024

Secretory proteins, including plasma membrane proteins, are generally known to be transported to the plasma membrane through the endoplasmic reticulum-to-Golgi pathway. However, recent studies have revealed that several plasma membrane proteins and cytosolic proteins lacking a signal peptide are released via an unconventional protein secretion (UcPS) route, bypassing the Golgi during their journey to the cell surface. For instance, transmembrane proteins such as the misfolded cystic fibrosis transmembrane conductance regulator (CFTR) protein and the Spike protein of coronaviruses have been observed to reach the cell surface through a UcPS pathway under cell stress conditions. Nevertheless, the precise mechanisms of the UcPS pathway, particularly the molecular machineries involving cytosolic motor proteins, remain largely unknown. In this study, we identified specific kinesins, namely KIF1A and KIF5A, along with cytoplasmic dynein, as critical players in the unconventional trafficking of CFTR and the SARS-CoV-2 Spike protein. Gene silencing results demonstrated that knockdown of KIF1A, KIF5A, and the KIF-associated adaptor protein SKIP, FYCO1 significantly reduced the UcPS of △F508-CFTR. Moreover, gene silencing of these motor proteins impeded the UcPS of the SARS-CoV-2 Spike protein. However, the same gene silencing did not affect the conventional Golgi-mediated cell surface trafficking of wild-type CFTR and Spike protein. These findings suggest that specific motor proteins, distinct from those involved in conventional trafficking, are implicated in the stress-induced UcPS of transmembrane proteins.

• Korean Journal of Food Science and Technology
• /
• v.39 no.3
• /
• pp.348-352
• /
• 2007

Inflammation is a complex process resulting from a variety of mechanisms. Combined inhibition of the activities of enzymes involved in the process may therefore be considered more important in anti-inflammatory property of plant extracts than any single contribution. In this study, the inhibitory effects of the ethanol extracts of thirty plant foods on the activities of secretory phospholipase $A_{2}$ ($sPLA_{2}$), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and 12-lipoxygenase (12-LOX) were examined. Several legumes, mungbean sprout and some leaf vegetables inhibited the activity of $sPLA_2$, upstream enzyme of inflammation pathway. Only soybean sprout and mungbean sprout significantly inhibited 12-LOX activity. Although most of extracts inhibited the activities of both COX-1 and COX-2, water dropwort and amaranth showed selectivity for the inhibition of COX-2 over COX-1. Especially, mungbean showed anti-inflammatory property at both upstream and downstream of inflammation pathway with relatively low $IC_{50}$ values for $sPLA_{2}$ and COX-2 enzymes. Mungbean sprout exhibited inhibitory effects on all enzymes related to early and late inflammation and soybean sprout suppressed 12-LOX and COX-2 simultaneously, although the activities of these plants were showed at relatively high concentration. Therefore, mungbean, mungbean sprout, and soybean sprout appear to exhibit anti-inflammatory effects by combined inhibition of inflammatory enzymes.

• The Korean Journal of Zoology
• /
• v.16 no.1
• /
• pp.25-41
• /
• 1973

Ultrastructural changes in the cells of the corpora allata of the pine moth, Dendrolimus spectabilis Butler, were studied by electron microscope to know the structural correlates of hormone production by the gland during the larval-pupal-adult transformations. Mitochondria are in active phases from the overwintered to the last instar larvae and from the pupae just after pupation to the 20-day old pupae, while they are in inactive phases from the making cocoon stage to the prepupae just before pupation. The peripheral allatum cells have electron dense granules in the intracellular vacuoles of smooth-surfaced endoplasmic reticulum in the larval life, particularly in the overwintered larvae and in the early adults but the swollen smooth-surfaced intracytoplasmic vacuoles made by expansion of an end of the tubular rough endoplasmic reticulum, some of which contain fibrous proteins, are observed in addition to the vacuoles in the intercellular spaces in which the vacuoles grow by fusing each other from the mature larvae to the prepupae, both of them disappearing during just before pupation. After pupation the cytolasmic vacuoles develop again in the allatum cells so that they seem to begin the secretory activity. The fact that the neurosecretory granules stored within the axons terminated in the corpus allatum are visible only from the 20-day old pupa about two days before abult emergence to the 5-day old adult means that the secretion from the allatum cells is under the control of the brain from the late pupal stage, while the secretion during from the larval to the early pupal life has no relation with the brain, because such granules are not observed within the axons. It is, therefore, suggested that at least two kinds of hormone are released with the ages as far as concerned with the production and secretion mechanisms of the allatum hormone: juvenile hormone is released until the last instar larvae without any direct stimlation of the brain and gonadotropic hormone is secreted from the late pupa to the adult by getting brain's stimulation and that the secretory phases observed from the mature larvae to prepupae are presumably concerned with the biosynthesis of protein owing to the ecdysone and those from the early pupal stage in uncontrolled condition of the brain with the prothoracotropic activity.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.4
• /
• pp.587-596
• /
• 2006

Most of oral streptococci express the Antigen I/II (AgI/II) proteins, cell wall anchored adhesions. AgI/II protein binds to salivary agglutinin glycoprotein, a component of tooth pellicle and to ligands in other bacteria. These associations play important roles in bacterial colonization. Recently, it was reported that diverse host molecules also interact with AgI/II protein and that these interactions induce inflammatory responses from host cells. Among mutans streptococci containing -type hemolytic activity, Streptococcus mutans is a causative agent for dental caries. Compared with many other strains of S. mutans, GS-5 strain is unique in that this bacterium expresses truncated secretory AgI/II protein due to the nonsense mutation in the agI/II gene. This indicates that S. mutans GS-5 has a different clinical role and a recent report supported this idea based on the results from clinically isolated S. mutans strains. Previously, we had cloned agI/II gene from S. mutans GS-5 and generated recombinant N-terminal AgI/II protein. In this study, we further produced a hybridoma line expressing anti-AgI/II monoclonal antibodies named as 1C11A. This antibody showed high sensitivity to AgI/II protein in Western blot and ELISA. This new reagent will provide a basis for investigating the mechanisms of AgI/II-related diseases.

• Tuberculosis and Respiratory Diseases
• /
• v.54 no.5
• /
• pp.532-541
• /
• 2003

Background : Phospholipase $A_2$ ($PLA_2$) has been known to be involved in the pathogenesis of acute lung injury (ALI) including ARDS. Since doxycycline has the property of inhibiting secretory group II $PLA_2$, the therapeutic effect of doxycycline hyclate was investigated for gut ischemia/reperfusion (I/R)-induced ALI in Sprague-Dawley rats. Methods : ALI was induced in Sprague-Dawley rats by clamping of the superior mesenteric artery for 60 min, followed by 120 min of reperfusion. To confirm the pathogenetic mechanisms of this ALI associated with neutrophilic oxidative stress, we measured bronchoalveolar lavage (BAL) protein content and lung MPO, and performed cyto-chemical electron microscopy for detection of free radicals, assay of $PLA_2$ activity and cytochrome-c reduction assay. Results : In gut I/R-induced ALI rats, protein leakage, pulmonary neutrophil accumulation, free radical production and lung $PLA_2$ activity were all increased. These effects were reversed by doxycycline hyclate. Conclusion : Doxycycline appears to be effective in ameliorating the gut I/R-induced ALI by inhibiting $PLA_2$, thereby decreasing the production of free radicals from neutrophils.

• Journal of Food Hygiene and Safety
• /
• v.35 no.6
• /
• pp.535-543
• /
• 2020

In addition to the ubiquitous roles of cellular RNA in genetic regulations, gene expression and phenotypic variations in response to environmental cues and chemotactic signals, the regulatory roles of a new type of RNA called extracellular RNAs (exRNAs) are an up-and-coming area of research interest. exRNA is transported outside the cell through membrane blebs known as membrane vesicles or extracellular vesicles (EVs). EV formation is predominant and conserved among all microbial forms, including prokaryotes, eukaryotes, and archaea. This review will focus on the three major topics concerning bacterially derived exRNAs, i.e., 1) the discovery of exRNA and influence of extraneous RNA over bacterial gene regulations, 2) the known secretion mechanism for the release of exRNA, and 3) the possible applications that can be devised with these exRNA secreted by different gram-negative and gram-positive bacteria. Further, this review will also provide an opinion on exRNA- and EV-derived applications such as the species-specific exRNA markers for diagnostics and the possible roles of exRNA in probiotics and the epigenetic regulations of the gut microbiome.

• Journal of Korean Medicine Rehabilitation
• /
• v.34 no.2
• /
• pp.15-28
• /
• 2024

Objectives We used the D-galactose (D-gal) induced C2C12 myoblast senescence model to investigate whether ethanol extract of Perilla. fructescens leaves (EEPF) could delay cellular senescence and regulate related mechanisms. Methods C2C12 myogenic cells were cultured in an incubator under 37 ℃ and 5% CO₂ conditions. EEPF, dried perilla leaves were pulverized and extracted at 1:10 (v/v) at 50 ℃ for 4 hours. Cell counting kit-8 and western blot analysis was performed. Annexin V-FITC apoptosis detection kit and DAPI staining was applied. Catalase (CAT), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and malondialdehyde analysis kits were used. To measure the level of reactive oxygen species generation, staining and flow cytometry was used. To analyze the mitochondrial activity, membrane potential changes were measured using JC-1. 𝛽-gal activity was analyzed using SA-𝛽-gal staining solution, and DNA damage was analyzed by using 𝛾-H2AX. Quantikine ELISA kit was used to analyze inflammatory cytokine production. Results According to the results of this study, EEPF significantly alleviated the decrease in cell viability in C2C12 cells treated with D-gal and suppressed the decrease in the expression of proliferating cell nuclear antigen. EEPF also markedly blocked D-gal-induced C2C12 cell apoptosis and restored reduced activity of CAT, GSH-Px, T-AOC, SOD. In addition, EEPF suppressed the decrease in 𝛽-galactosidase activity, the induction of DNA damage and the increase in expression of senescence-associated secretory phenotype proteins such as p16, p53 and p21 in D-gal-treated C2C12 cells. Furthermore, EEPF significantly attenuated D-gal-induced production and expression of inflammatory cytokines such as interleukin (IL)-6 and IL-18. Conclusions The results of this study indicate that EEPF can be used as a potential candidate for the prevention and treatment of muscle aging.

• Molecules and Cells
• /
• v.37 no.2
• /
• pp.178-186
• /
• 2014

Differential transcription of the clusterin (CLU) gene yields two CLU isoforms, a nuclear form (nCLU) and a secretory form (sCLU), which play crucial roles in prostate tumorigenesis. Pro-apoptotic nCLU and anti-apoptotic sCLU have opposite effects and are differentially expressed in normal and cancer cells; however, their regulatory mechanisms at the transcriptional level are not yet known. Here, we examined the transcriptional regulation of nCLU in response to hypoxia. We identified three putative hypoxia response elements (HREs) in the human CLU promoter between positions -806 and +51 bp. Using a luciferase reporter, electrophoretic gel mobility shift, and chromatin immunoprecipitation assays, we further showed that hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) bound directly to these sites and activated transcription. Exposure to the hypoxia-mimetic compound $CoCl_2$, incubation under 1% $O_2$ conditions, or overexpression of HIF-$1{\alpha}$ enhanced nCLU expression and induced apoptosis in human prostate cancer PC3M cells. However, LNCaP prostate cancer cells were resistant to hypoxia-induced cell death. Methylation-specific PCR analysis revealed that the CLU promoter in PC3M cells was not methylated; in contrast, the CLU promoter in LNCap cells was methylated. Co-treatment of LNCaP cells with $CoCl_2$ and a demethylating agent promoted apoptotic cell death through the induction of nCLU. We conclude that nCLU expression is regulated by direct binding of HIF-$1{\alpha}$ to HRE sites and is epigenetically controlled by methylation of its promoter region.