Publications by authors named "Misun Kwak"

Antibiotic susceptibilities, hemolytic activities, and technological properties of 46 isolates from kimchi were evaluated to select starter candidates. All strains were susceptible to clindamycin and erythromycin, while some exhibited resistance to ampicillin, chloramphenicol, gentamicin, streptomycin, and tetracycline; all were resistant to kanamycin based on the EFSA breakpoint values for species. PCR analysis did not detect resistance genes for these six antibiotics in any strain.

View Article and Find Full Text PDF

Postbiotics, bioactive compounds from the fermentation process by probiotics, are gaining attention for their potential health benefits as safer alternatives to live probiotic microbes. is a well-studied probiotic species known for promoting gut health and immune modulation. However, the safety and effects of its postbiotic formulations on the gut microbiome structure remain less explored.

View Article and Find Full Text PDF

PKD1 regulates a number of cellular processes through the formation of complexes with the PKD2 ion channel or transient receptor potential classical (TRPC) 4 in the endothelial cells. Although Ca modulation by polycystins has been reported between PKD1 and TRPC4 channel or TRPC1 and PKD2, the function with TRPC subfamily regulated by PKD2 has remained elusive. We confirmed TRPC4 or TRPC5 channel activation via PKD1 by modulating G-protein signaling without change in TRPC4/C5 translocation.

View Article and Find Full Text PDF

Sarcopenia refers to an age-related decrease in muscle mass and strength. The gut-muscle axis has been proposed as a promising target to alleviate muscle atrophy. The effect of KL-Biome-a postbiotic preparation comprising heat-killed KM-2, its metabolites, and an excipient (soybean powder)-on muscle atrophy was evaluated using dexamethasone (DEX)-induced atrophic C2C12 myoblasts and C57BL/6J mice.

View Article and Find Full Text PDF

The effects of jogi (the fish Atlantic croaker, Micropogonias undulatus) on the production of physicochemical components, such as color, organic acids, and amino acids, in kimchi, a traditional fermented vegetable food of Korea, were determined. As fermentation progressed, the color change of jogi-added kimchi increased, but in comparison with that of the control group without jogi-added kimchi, was difficult to distinguish with the naked eye. Reducing sugar decreased in all experimental groups, and as fermentation progressed, kimchi with jogi showed a lower value.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers are focusing more on postbiotics for preventing metabolic diseases because they are more stable and safer than probiotics.
  • A study tested the cell-free culture supernatant of KMU01 (CFS-) on mice fed a high-fat diet and found that it positively impacted their gut microbiota and reduced obesity markers.
  • The results indicate that CFS- could serve as a new anti-obesity treatment by improving various obesity-related health metrics and regulating gut bacteria.
View Article and Find Full Text PDF
Article Synopsis
  • * Out of the isolates, 10 were confirmed as Salmonella spp. through genetic sequencing, and 8 showed resistance to at least one antibiotic, with 5 classified as multi-drug resistant.
  • * A lytic phage, vB_SalS_KFSSM, was isolated from cow manure and demonstrated effectiveness against various Salmonella strains, suggesting its potential as a treatment for antibiotic-resistant Salmonella.
View Article and Find Full Text PDF

Background/aim: Owing to the nearly three-year-long COVID-19 pandemic, small personal transportation devices that allow for greater freedom of movement within the cities have gained attention. Therefore, the number of people using kick or electric scooters has increased. This study aimed to compare the characteristics of kick and electric scooter-related dental and maxillofacial trauma and provide helpful information for preventing scooter accidents, appropriate treatment of patients with scooter-related trauma, and policy establishment.

View Article and Find Full Text PDF

The purpose of this study was to investigate the effect that hydrolyzed with enzymes from KMU01 has on dextran-sulfate-sodium (DSS)-induced colitis in mice. Hydrolysis improves functional health through the bioconversion of raw materials and increase in intestinal absorption rate and antioxidants. Therefore, was hydrolyzed in this study using a food-derived microorganism, and its anti-inflammatory effect was observed.

View Article and Find Full Text PDF

Transient receptor potential channels canonical 1 and 4 (TRPC1 and TRPC4) are proteins belonging to the same TRPC channel family, and the two are known to form a heterotetrameric channel. TRPC4 can form a homotetrameric, nonselective cation channel by itself, but the involvement of the TRPC1 subunit changes several major characteristics of the channel. In this study, we focused on the pore region (selectivity filter, pore helix, and S6 helix) of TRPC1 and TRPC4 as a determinant of the identity and characteristics of a heteromeric TRPC1/4 channel: decreased calcium permeability of the channel and outward-rectifying current-voltage (-) curve.

View Article and Find Full Text PDF

G-protein coupled receptors (GPCRs) and ion channels serve as key molecular switches through which extracellular stimuli are transformed into intracellular effects, and it has long been postulated that ion channels are direct effector molecules of the alpha subunit of G-proteins (Gα). However, no complete structural evidence supporting the direct interaction between Gα and ion channels is available. Here, we present the cryo-electron microscopy structures of the human transient receptor potential canonical 5 (TRPC5)-Gα complexes with a 4:4 stoichiometry in lipid nanodiscs.

View Article and Find Full Text PDF

Transient receptor potential canonical (TRPC) channels are non-selective calcium-permeable cation channels. It is suggested that TRPC4β is regulated by phospholipase C (PLC) signaling and is especially maintained by phosphatidylinositol 4,5-bisphosphate (PIP). In this study, we present the regulation mechanism of the TRPC4 channel with PIP hydrolysis which is mediated by a channel-bound PLCδ1 but not by the GPCR signaling pathway.

View Article and Find Full Text PDF

Recent studies have revealed that probiotics and their metabolites are present under various conditions; however, the role of probiotic metabolites (, postbiotics in pathological states) is controversial. Natural killer (NK) cells play a key role in innate and adaptive immunity. In this study, we examined NK cell activation influenced by a postbiotics mixture in response to gut microbiome modulation in stress-induced mice.

View Article and Find Full Text PDF

In this study, the bacterial community of galchi-baechu kimchi was determined using culture-based and culture-independent techniques (next generation sequencing:NGS), and showed discrepancies between results. and were the dominant species according to the NGS results, while species and were dominant in the culture-dependent analysis. To identify safe starter candidates, sixty-five strains isolated from galchi-baechu kimchi using culture-dependent methods were evaluated for their antibiotic resistance, presence of toxin genes, and hemolytic activity.

View Article and Find Full Text PDF

strain B28 was previously isolated from traditional Korean fermented and inhibited expression of the microphthalmia-associated transcription factor and β-catenin in human embryonic kidney 293 cells. Here, we determined the complete genome sequence of strain B28 and compared it with other strains to elucidate its potential probiotic properties. Strain B28 does not contain antibiotic resistance-, hemolysin- or enterotoxin-encoding genes.

View Article and Find Full Text PDF

strain KMU01 showing γ-glutamyltransferase activity as a probiotic candidate was isolated from kimchi. However, the genetic information on strain KMU01 was not clear. Therefore, the current investigation was undertaken to prove the probiotic traits of strain KMU01 through genomic analysis.

View Article and Find Full Text PDF

Protein S-palmitoylation, the covalent lipid modification of the side chain of Cys residues with the 16‑carbon fatty acid palmitate, is the most common acylation, and it enhances the membrane stability of ion channels. This post-translational modification (PTM) determines a functional mechanism of ion channel life cycle from maturation and membrane trafficking to localization. Especially, neurodevelopment is regulated by balancing the level of synaptic protein palmitoylation/depalmitoylation.

View Article and Find Full Text PDF

Gα-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate (PI(4,5)P) depletion. When PI(4,5)P depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p.

View Article and Find Full Text PDF

Poly-γ-glutamate (γ-PGA) has various applications due to its desirable characteristics in terms of safety and biodegradability. Previous studies have been conducted on γ-PGA hydrogels produced by γ-ray irradiation, but these hydrogels have proved unstable in solutions. This study was conducted to enable the γ-PGA hydrogel to maintain a stable form in solutions.

View Article and Find Full Text PDF

Transient receptor potential canonical (TRPC) channels are calcium permeable, non-selective cation channels with wide tissue-specific distribution. Among 7 TRPC channels, TRPC 1/4/5 and TRPC3/6/7 are subdivided based on amino acid sequence homology. TRPC4 and TRPC5 channels exhibit cationic current with homotetrameric form, but they also form heterotetrameric channel such as TRPC1/4 or TRPC1/5 once TRPC1 is incorporated.

View Article and Find Full Text PDF

Polycystic kidney disease 2-like-1 (PKD2L1), polycystin-L or transient receptor potential polycystin 3 (TRPP3) is a TRP superfamily member. It is a calcium-permeable non-selective cation channel that regulates intracellular calcium concentration and thereby calcium signaling. Although the calmodulin (CaM) inhibitor, calmidazolium, is an activator of the PKD2L1 channel, the activating mechanism remains unclear.

View Article and Find Full Text PDF

The transient receptor potential canonical (TRPC) 1 channel is widely distributed in mammalian cells and is involved in many physiological processes. TRPC1 is primarily considered a regulatory subunit that forms heterotetrameric channels with either TRPC4 or TRPC5 subunits. Here, we suggest that the regulation of TRPC1/4 and TRPC1/5 heterotetrameric channels by the Gα-PLCβ pathway is self-limited and dynamically mediated by Gα and PI(4,5)P.

View Article and Find Full Text PDF

Hypertension and aneurysm are frequently associated with autosomal dominant polycystic kidney disease (ADPKD) caused by polycystin-1 (PC1) mutations, which is closely related to endothelial dysfunction. PC1 is an atypical G-protein-coupled receptor that activates G-proteins by self-cleavage; currently, however, the molecular and cellular mechanisms of the associated intracellular signaling and ion channel activation remain poorly elucidated. Here, we report an activation mechanism of a calcium-permeable canonical transient receptor potential 4 (TRPC4) channel by PC1 and its endothelial function.

View Article and Find Full Text PDF

This study compared the radioprotective effects of high-molecular-weight poly-gamma-glutamate (γ-PGA, average molecular mass 3,000 kDa) and a reduced form of glutathione (GSH, a known radioprotector) on calf thymus DNA damage. The radiation-induced DNA damage was measured on the basis of the decreased fluorescence intensity after binding the DNA with ethidium bromide. All the experiments used ⁶⁰Co gamma radiation at 1,252 Gy, representing 50% DNA damage.

View Article and Find Full Text PDF

Polycystic kidney disease 2-like-1 (PKD2L1), or polycystin-L or TRPP2, formerly TRPP3, is a transient receptor potential (TRP) superfamily member. It is a calcium-permeable non-selective cation channel that regulates intracellular calcium concentration and thereby calcium signaling. PKD2L1 has been reported to take part in hedgehog signaling in renal primary cilia and sour tasting coupling with PKD1L3.

View Article and Find Full Text PDF