Kyungmoo Yea

The Scripps Research Institute | scripps · Department of Chemistry

Small extracellular vesicles (sEVs) secreted by most cells carry bioactive macromolecules including proteins, lipids, and nucleic acids for intercellular communication. Given that some immune cell-derived sEVs exhibit anti-cancer properties, these sEVs have received scientific attention for the development of novel anticancer immunotherapeutic agen...

Interferon-γ (IFNG) is one of the key cytokines that regulates both innate and adaptive immune responses in the body. However, the role of IFNG in the regulation of vascularization, especially in the context of Vascular endothelial growth factor A (VEGFa)-induced angiogenesis is not clarified. Here, we report that IFNG shows potent anti-angiogenic...

Estrogen therapy is used to treat patients with post-menopausal symptoms, such as hot flashes and dyspareunia. Estrogen therapy also decreases the risk of fractures from osteoporosis in post-menopausal women. However, estrogen increases the risk of venous thromboembolic events, such as pulmonary embolism, but the pathways through which estrogen inc...

Herein we present a concept in cancer where an immune response is detrimental rather than helpful. In the cancer setting, the immune system is generally considered to be helpful in curtailing the initiation and progression of tumors. In this work we show that a patient’s immune response to their tumor can, in fact, either enhance or inhibit tumor c...

Microchips are widely used to separate circulating tumor cells (CTCs) from whole blood by virtues of sophisticated manipulation for microparticles. Here, we present a chip with an 8 μm high and 27.9 mm wide slit to capture cancer cells bound to 3 μm beads. Apart from a higher purity and recovery rate, the slit design allows for simplified fabricati...

Pipetting techniques play a crucial role in obtaining reproducible and reliable results, especially when seeding cells on small target areas, such as on microarrays, biochips or microfabricated cell culture systems. For very rare cells, such as human primary skeletal muscle cells (skMCs), manual (freehand) cell seeding techniques invariably result...

Adiponectin (Ad) is a representative adipocytokine that regulates energy homeostasis including glucose transport and lipid oxidation through activation of AMP-activated protein kinase (AMPK) pathways. Plasma levels of Ad are reduced in obesity, which contributes to type 2 diabetes. Therefore, agents that activate the Ad signaling pathway could amel...

Previously, we reported an agonist antibody to a cytokine receptor, Thrombopoietin receptor (TPOR) that effectively induces cytotoxic killer cells from precursor tumor cells isolated from newly diagnosed AML patients. Here, we show that the TPOR agonist antibody can induce even relapsed AML cells into killer cells more potently than newly diagnosed...

[This corrects the article DOI: 10.18632/oncotarget.23401.].

Interleukin-5 (IL-5) is best known as key regulator in eosinophil-associated diseases such as asthma. While a connection to vascular changes in eosinophil-associated lung diseases is still elusive, recent evidence suggests that IL-5 may have an atheroprotective role. Here, we report an unexpected anti-angiogenic potential of IL-5 on vascular endoth...

Cytokines are protein mediators that are known to be involved in many biological processes, including cell growth, survival, inflammation, and development. To study their regulation, we generated a library of 209 different cytokines. This was used in a combinatorial format to study the effects of cytokines on each other, with particular reference t...

Background: Anti-angiogenic biologicals represent an important concept for the treatment of vasoproliferative diseases. However, the need for continued treatment, the presence of nonresponders, and the risk of long-term side effects limit the success of existing therapeutic agents. Although Tspan12 has been shown to regulate retinal vascular devel...

Intramuscular lipid accumulation is a common manifestation of chronic caloric excess and obesity that is strongly associated with insulin resistance. The mechanistic links between lipid accumulation in myocytes and insulin resistance are not completely understood. In this work, we used a high-throughput chemical biology screen to identify a small-m...

Animal venoms represent a rich source of pharmacologically active peptides that interact with ion channels. However, a challenge to discovering drugs remains because of the slow pace at which venom peptides are discovered and refined. An efficient autocrine-based high-throughput selection system was developed to discover and refine venom peptides t...

Animal venoms represent a rich source of pharmacologically active peptides that interact with ion channels. However, a challenge to discovering drugs remains because of the slow pace at which venom peptides are discovered and refined. An efficient autocrine-based high-throughput selection system was developed to discover and refine venom peptides t...

Animal venoms represent a rich source of pharmacologically active peptides that interact with ion channels. In their Communication (DOI: 10.1002/anie.201603052), R. A. Lerner, H. Zhang, and co-workers describe an autocrine-based method to select functional venom peptides from their vast repertoire in nature. This method allows about 100 million dif...

Tierische Gifte sind eine natürliche Quelle pharmakologisch aktiver Peptide, die mit Ionenkanälen wechselwirken. In ihrer Zuschrift (DOI: 10.1002/ange.201603052) beschrieben R. A. Lerner, H. Zhang et al. ein Autokrin-basiertes Auswahlverfahren für funktionelle Giftpeptide. Etwa 100 Million Giftstoffe wurden in einem einzigen Experiment untersucht,...

Glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists have emerged as treatment options for type 2 diabetes mellitus (T2DM). GLP-1R signals through G-protein-dependent, and G-protein-independent pathways by engaging the scaffold protein β-arrestin; preferential signalling of ligands through one or the other of these branches is known as 'ligan...

Supplementary Figures 1-7 and Supplementary Table 1-3.

An attractive, but as yet generally unrealized, approach to cancer therapy concerns discovering agents that change the state of differentiation of the cancer cells. Recently, we discovered a phenomenon that we call "receptor pleiotropism" in which agonist antibodies against known receptors induce cell fates that are very different from those induce...

To date, most antibodies from combinatorial libraries have been selected purely on the basis of binding. However, new methods now allow selection on the basis of function in animal cells. These selected agonist antibodies have given new insights into the important problem of signal transduction. Remarkably, when some antibodies bind to a given rece...

The main purpose of this perspective is to build on the unexpected outcomes of previous laboratory experiments using antibody agonists to raise questions concerning how activation of a given receptor can be involved in inducing differentiation of cells along different pathways some of which may even derive from different lineages. While not yet ans...

Apolipoprotein a1, which is a major lipoprotein component of high-density lipoprotein (HDL), was reported to decrease plasma glucose in type 2 diabetes. Although recent studies also have shown that apolipoprotein a1 is involved in triglyceride (TG) metabolism, the mechanisms by which apolipoprotein a1 modulates TG levels remain largely unexplored....

Obesity-induced inflammation is initiated by the recruitment of macrophages into adipose tissue. The recruited macrophages, called adipose tissue macrophages, secrete several proinflammatory cytokines that cause low-grade systemic inflammation and insulin resistance. The aim of this study was to find macrophage-recruiting factors that are thought t...

One of the most important phenotypes in biology is cell death. One way to probe the mechanism(s) of cell death is to select molecules that prevent it and learn how this was accomplished. Here, intracellular combinatorial antibody libraries were used to select antibodies that protected cells from killing by rhinovirus infection. These rare antibodie...

When combinatorial antibody libraries are rendered infectious for eukaryotic cells, the integrated antibody genotype and cellular phenotype become permanently linked and each cell becomes a selection system unto itself. These systems should be ideal for the identification of proteins and pathways that regulate differentiation so long as selection s...

We describe a system for direct selection of antibodies that are receptor agonists. Combinatorial antibody libraries in lentiviruses are used to infect eukaryotic cells that contain a fluorescent reporter system coupled to the receptor for which receptor agonist antibodies are sought. In this embodiment of the method, very large numbers of candidat...

Background: Afamin was recently identified as a novel osteoclast-derived coupling factor that can stimulate the in vitro and in vivo migration of preosteoblasts. Aim: In order to understand in more detail the biological roles of afamin in bone metabolism, we investigated its effects on osteoclastic differentiation and bone resorption. Methods:...

We report here the generation of antibody agonists from intracellular combinatorial libraries that transdifferentiate human stem cells. Antibodies that are agonists for the granulocyte colony stimulating factor receptor were selected from intracellular libraries on the basis of their ability to activate signaling pathways in reporter cells. We used...

Wedelolactone is an herbal medicine that is used to treat septic shock, hepatitis and venom poisoning. Although in differentiated and cancer cells, wedelolactone has been identified as anti-inflammatory, growth inhibitory, and pro-apoptotic, the effects of wedelolactone on stem cell differentiation remain largely unknown. Here, we report that wedel...

Although it is well known that osteoclastic bone resorption is followed by osteoblastic bone formation, questions remain as to when coupling factors are produced during bone resorption and which stages of bone formation are affected by these factors. To clarify these mechanisms, we established an in vitro system to investigate the coupling phenomen...

There is a strong possibility that skeletal muscle can respond to irregular metabolic states by secreting specific cytokines. Obesity-related chronic inflammation, mediated by pro-inflammatory cytokines, is believed to be one of the causes of insulin resistance that results in type 2 diabetes. Here, we attempted to identify and characterize the mem...

We previously demonstrated a cardiac mitochondrial biogenic response in insulin resistant mice that requires the nuclear receptor transcription factor PPARα. We hypothesized that the PPARα coactivator peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) is necessary for mitochondrial biogenesis in insulin resistant hearts a...

Ochratoxin A (OTA) is a ubiquitous fungal metabolite with nephrotoxic, carcinogenic, and apoptotic potential. Although the toxic effects of OTA in various cell types are well characterized, it is not known whether OTA has an effect on stem cell differentiation. In this study, we demonstrate that OTA inhibits adipogenesis in human adipose tissue-der...

Interleukin 6 (IL6) is a pleiotropic cytokine that not only affects the immune system, but also plays an active role in many physiological events in various organs. Notably, 35% of systemic IL6 originates from adipose tissues under noninflammatory conditions. Here, we describe a previously unknown function of melanocortins in regulating Il6 gene ex...

Background: Glucose homeostasis is maintained by a balance between hepatic glucose production and peripheral glucose utilization. In skeletal muscle cells, glucose utilization is primarily regulated by glucose uptake. Deprivation of cellular energy induces the activation of regulatory proteins and thus glucose uptake. AMP-activated protein kinase...

Adipocytes are well known to release regulation factors associated with metabolic disorders. In particular, increased oxidative stress in adipocytes contributes to dysregulation of adipokine production. In this study, we applied relative quantitative proteomic analysis based on label-free multiple reaction monitoring (MRM) to discover biological ch...

Adipogenesis is a complex process that is accompanied by a number of molecular events. In this study, a proteomic approach was adopted to identify secretory factors associated with adipogenesis. A label-free shotgun proteomic strategy was implemented to analyze proteins secreted by human adipose stromal vascular fraction cells and differentiated ad...

To investigate whether sulforaphane (SFN), an isothiocyanate derived from cruciferous vegetables such as broccoli, regulates synoviocyte hyperplasia and T cell activation in rheumatoid arthritis (RA). Synoviocyte survival was assessed by MTT assay. The levels of Bcl-2, Bax, p53, and pAkt were determined by Western blot analysis. Cytokine concentrat...

Glucose homeostasis is maintained by the orchestration of peripheral glucose utilization and hepatic glucose production, mainly by insulin. In this study, we found by utilizing a combined parallel chromatography mass profiling approach that lysophosphatidylcholine (LPC) regulates glucose levels. LPC was found to stimulate glucose uptake in 3T3-L1 a...

Hypoxia during the expansion of adipocytes is known to contribute both to the secretion of multiple inflammation-related adipokines as well as to obesity. We therefore investigated the nature of protein changes occurring in adipocytes during hypoxia by observation of the intracellular proteins that are expressed in 3T3-L1 adipocytes. Lysates were u...

Lysophosphatidylserine (LPS) is known to have diverse cellular effects, but although LPS is present in many biological fluids, its in vivo effects have not been elucidated. In the present study, we investigated the effects of LPS on glucose metabolism in vivo, and how skeletal muscle cells respond to LPS stimulation. LPS enhanced glucose uptake in...

Emerging evidence has revealed an endocrine function for skeletal muscle; in fact, certain anti-inflammatory cytokines are secreted only from contractile skeletal muscle. However, the skeletal muscle secretome as a whole is poorly characterized, as is how it changes in response to extracellular stimuli. Herein, we sought to identify and characteriz...

Epidermal growth factor (EGF) is synthesized in the pancreas and diabetic animals have low levels of EGF. However, the role of EGF in regulating the major function of the pancreas, insulin secretion, has not been studied. Here, we show that EGF rapidly increased insulin secretion in mouse pancreatic islets, as well as in a pancreatic beta-cell line...

Mast cells play a central role in allergic disease and host defense against several pathogens through the release of various bioactive compounds via degranulation. In this study, we found that a myristoylated pseudosubstrate of PKC-zeta (zeta-PS; myristoyl-SIYRRGARRWRKL, a PKC-zeta inhibitor) regulates mast cell degranulation. zeta-PS increased [Ca...

Lysophosphatidic acid (LPA) is known to have diverse cellular effects, but although LPA is present in many biological fluids, including blood, its effects on glucose metabolism have not been elucidated. In this study, we investigated whether LPA stimulation is related to glucose regulation. LPA was found to enhance glucose uptake in a dose-dependen...

We introduce a new methodology named ligand profiling and identification for effective discovery of bioactive ligands such as peptide hormones. This technology was developed from a new concept of parallel column chromatography and active fraction profiling by nano-LC MS. Traditional methods use sequential column chromatography, and thus are inevita...

The gastrointestinal functions of secretin have been fairly well established. However, its function and mode of action within the nervous system remain largely unclear. To gain insight into this area, we have attempted to determine the effects of secretin on neuronal differentiation. Here, we report that secretin induces the generation of neurite o...