Publications by authors named "Min-Kyung Choo"

Keratinocytes, the epithelial cells of the skin, reprogram their gene expression and produce immune effector molecules when exposed to environmental and endogenous triggers of inflammation. It remains unclear how keratinocytes process physiological signals generated during skin irritation and switch from a homeostatic to an inflammatory state. In this article, we show that the stress-activated protein kinase p38α is crucial for keratinocytes to prompt changes in their transcriptome upon cytokine stimulation and drive inflammation in allergen-exposed skin.

View Article and Find Full Text PDF
Article Synopsis
  • Hematopoietic-derived cells, including those from myeloid and lymphoid lineages, are important for tumor-host interactions and influence cancer development and response to treatment.
  • New evidence suggests that erythroid cells, which typically produce red blood cells, may also play a role in cancer dynamics, particularly through the action of erythropoietin, a hormone that stimulates red blood cell production.
  • Research shows that these tumor-induced erythroid cells have specific molecular features and that blocking erythropoietin can reduce both their induction and tumor growth, suggesting they could be potential targets for cancer therapies.
View Article and Find Full Text PDF

Cellular senescence is a major barricade on the path of cancer development, yet proteins secreted from senescent cells exert complex and often discordant effects on subsequent cancer evolution. Somatic genome alternations driving the formation of nevi and melanoma are efficient inducers of cellular senescence. Melanocyte and melanoma cell senescence is likely to come into play as a key factor affecting the course of tumorigenesis and responsiveness to therapy; little mechanistic information has been generated, however, that substantiates this idea and facilitates its clinical translation.

View Article and Find Full Text PDF

Background: Quiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown.

View Article and Find Full Text PDF

Dendritic cells (DCs) abundantly express diverse receptors to recognize mannans in the outer surface of Candida cell wall, and these interactions dictate the host immune responses that determine disease outcomes. C. krusei prevalence in candidiasis worldwide has increased since this pathogen has developed multidrug resistance.

View Article and Find Full Text PDF

The molecular circuitry directing tissue development and homeostasis is hardwired by genetic programs but may also be subject to fine-tuning or major modification by environmental conditions. It remains unclear whether such malleability is at work-particularly in tissues directly in contact with the environment-and contributes to their optimal maintenance and resilience. The protein kinase p38α is activated by physiological cues that signal tissue damage and neoplastic transformation.

View Article and Find Full Text PDF

The retinoic acid receptor-related orphan receptors RORα and RORγ are critical for the functions of specific subsets of T cells and innate lymphoid cells, which are key drivers of inflammatory disease in barrier tissues. Here, we investigate the anti-inflammatory potential of SR1001, a synthetic RORα/γ inverse agonist, in mouse models of atopic dermatitis and acute irritant dermatitis. Topical treatment with SR1001 reduces epidermal and dermal features of MC903-induced atopic dermatitis-like disease and suppresses the production of type 2 cytokines and other inflammatory mediators in lesional skin.

View Article and Find Full Text PDF

Post-translational redox modification of methionine residues often triggers a change in protein function. Emerging evidence points to this reversible protein modification being an important regulatory mechanism under various physiological conditions. Reduction of oxidized methionine residues is catalyzed by methionine sulfoxide reductases (Msrs).

View Article and Find Full Text PDF

The spores of pathogenic bacteria are involved in host entry and the initial encounter with the host immune system. How bacterial spores interact with host immunity, however, remains poorly understood. Here, we show that the spores of (BA), the etiologic agent of anthrax, possess an intrinsic ability to induce host immune responses.

View Article and Find Full Text PDF

The evolutionarily conserved protein kinase p38 mediates innate resistance to environmental stress and microbial infection. Four p38 isoforms exist in mammals and may have been co-opted for new roles in adaptive immunity. Murine T cells deficient in p38α, the ubiquitously expressed p38 isoform, showed no readily apparent cell-autonomous defects while expressing elevated amounts of another isoform, p38β.

View Article and Find Full Text PDF
Article Synopsis
  • Obesity and insulin resistance are linked to oxidative stress, and JNK1 has been identified as a potential drug target for obesity and type 2 diabetes treatment.
  • A study investigated the long-term effects of JNK1 inactivation in obese mice on glucose regulation and oxidative stress, revealing that JNK1(-/-) mice on a high-fat diet had decreased antioxidant gene expression and more oxidative damage in their skin.
  • Despite the skin damage, JNK1 ablation provided significant metabolic benefits, such as reduced obesity, inflammation, and insulin resistance, suggesting that targeting JNK1 in specific tissues could offer a safer treatment approach.
View Article and Find Full Text PDF

The protein kinase p38α mediates cellular responses to environmental and endogenous cues that direct tissue homeostasis and immune responses. Studies of mice lacking p38α in several different cell types have demonstrated that p38α signaling is essential to maintaining the proliferation-differentiation balance in developing and steady-state tissues. The mechanisms underlying these roles involve cell-autonomous control of signaling and gene expression by p38α.

View Article and Find Full Text PDF

An improved understanding of the molecular pathways that drive tooth morphogenesis and enamel secretion is needed to generate teeth from organ cultures for therapeutic implantation or to determine the pathogenesis of primary disorders of dentition (Abdollah, S., Macias-Silva, M., Tsukazaki, T.

View Article and Find Full Text PDF

The epithelium of mucosal and skin surfaces serves as a permeability barrier and affords mechanisms for local immune defense. Crucial to the development and maintenance of a properly functioning epithelium is the balance of cell proliferation, differentiation, and death. Here we show that this balance depends on cross-regulatory interactions among multiple protein kinase-mediated signals and their coordinated transmission.

View Article and Find Full Text PDF

The cytokine interleukin-4 (IL-4) exerts pleiotropic effects on macrophages as it plays a key role in the immune response to infectious agents, allergens, and vaccines. Macrophages exposed to IL-4 drastically change their gene expression and metabolic state to adjust to new functional requirements. IL-4 also induces macrophages to fuse together and form multinucleated giant cells (MGCs).

View Article and Find Full Text PDF

Unlabelled: The transcription factor NF-κB promotes survival of cancer cells exposed to doxorubicin and other chemotherapeutic agents. IκB kinase is essential for chemotherapy-induced NF-κB activation and considered a prime target for anticancer treatment. An IκB kinase inhibitor sensitized human melanoma xenografts in mice to killing by doxorubicin, yet also exacerbated treatment toxicity in the host animals.

View Article and Find Full Text PDF

We previously reported that the in vivo and in vitro suppression of Nuclear Factor of Activated T Cells (NFAT) signaling increases osteoblast differentiation and bone formation. To investigate the mechanism by which NFATc1 regulates osteoblast differentiation, we established an osteoblast cell line that overexpresses a constitutively active NFATc1 (ca-NFATc1). The activation of NFATc1 significantly inhibits osteoblast differentiation and function, demonstrated by inhibition of alkaline phosphatase activity and mineralization as well as a decrease in gene expression of early and late markers of osteoblast differentiation such as osterix and osteocalcin, respectively.

View Article and Find Full Text PDF

ErbB3 receptor tyrosine kinase has been shown to induce tumor progression in several types of cancer through heterodimerization with ErbB2. However, the role of ErbB3 and its ligand heregulin (HRG) in tumor metastasis remains poorly understood. In the present study, we tried to clarify their contributions to the metastasis of ErbB3-overexpressing B16-BL6 melanoma cells.

View Article and Find Full Text PDF

SC-514, an inhibitor of IkappaB kinase beta (IKKbeta), blocked the TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) as well as the TNF-alpha-promoted metastasis of murine colon adenocarcinoma cells. We investigated the effect of 20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol (M1), a main intestinal bacterial metabolite of ginseng, on the NF-kappaB-dependent metastasis. M1 was effective in suppressing the TNF-alpha-induced activation of NF-kappaB, expression of matrix metalloprotease-9 (MMP-9), migration and invasion.

View Article and Find Full Text PDF

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/Apo2L) is a member of the TNF-alpha ligand family that selectively induces apoptosis in a variety of tumor cells. To clarify the molecular mechanism of TRAIL-induced apoptosis, we focused on transforming growth factor-beta-activated kinase 1 (TAK1) mitogen-activated protein kinase (MAPK) kinase kinase, a key regulator of the TNF-alpha-induced activation of p65/RelA and c-Jun NH2-terminal kinase/p38 MAPKs. In human cervical carcinoma HeLa cells, TRAIL induced the delayed phosphorylation of endogenous TAK1 and its activator protein TAB1 and TAB2, which contrasted to the rapid response to TNF-alpha.

View Article and Find Full Text PDF

Although obesity is known as a risk factor for several human cancers, the association of obesity with cancer recurrence and metastasis remains to be characterized. Here, B16-BL6 melanoma and Lewis lung carcinoma cells were intravenously injected into diabetic (db/db) and obese (ob/ob) mice. The number of experimental lung colonies was markedly promoted in these mice when compared with C57BL/6 mice.

View Article and Find Full Text PDF

Most herbal medicines that are orally administrated have been known to be metabolized before they are absorbed from the gastrointestinal tract. We, therefore, examined the effects of 20(S)-ginsenosides Rb1, Rg1 and Rg3, the three most commonly studied ginsenosides in the central nervous system, and their main metabolites on NMDA receptors using fura-2-based digital imaging and perforated whole-cell patch-clamp techniques. Among the nine ginsenosides tested, 20(S)-ginsenoside Rh2 (20(S)-Rh2) along with 20(S)-ginsenoside Rg3 (20(S)-Rg3) produced the highest inhibitory effect in cultured hippocampal neurons.

View Article and Find Full Text PDF

Purpose: To investigate the clinical significance of bilateral temporal hypometabolism (BTH) for patients with mesial temporal lobe epilepsy (MTLE) by using statistical parametric mapping (SPM).

Methods: Interictal 18F-FDG PET scans were performed for 29 patients with surgically treated MTLE. Clinical data, interictal epileptiform discharges (IEDs), ictal scalp EEG and intracarotid amobarbital test (IAT) were analyzed.

View Article and Find Full Text PDF

We have recently established a TNF-alpha-promoted metastasis model, in which the ability to metastasize to the lung was enhanced by stimulation of cultured colon 26 cells with TNF-alpha before intravenous inoculation. To investigate intracellular events in metastatic cascades of TNF-alpha-treated cancer cells, we have focused on the stress signaling pathways to c-Jun N-terminal kinase (JNK) and p38. Treatment with a specific inhibitor, SP600125 or SB203580, in vitro suppressed TNF-alpha-induced migration and pulmonary metastasis.

View Article and Find Full Text PDF

We investigated the influence of TNF-alpha on the metastasis of cancer cells. Treatment of cultured colon 26 cells with TNF-alpha enhanced metastatic properties including production of MMP-9, adhesion, migration and invasion. Cells treated with TNF-alpha in vitro showed marked potential to metastasize to the lung and liver in vivo.

View Article and Find Full Text PDF