• Journal of Plant Biology
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• v.34 no.3
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• pp.239-244
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• 1991

Ca2+ is implicated as a second messenger in coupling various stimuli such as hormone, gravity and light. The determine whether or not plant hormones mobilize calcium with different action, we investigated the cytosolic Ca2+ changes by IAA and zeatin in the protoplasts isolated from elongating mesocotyl of maize. IAA increased the influx of Ca2+ due to the calcium channel opening, which was confirmed by using verapamil, calcium channel blocker. On the other hand, zeatin increased the cytosolic Ca2+ by promoting the efflux of Ca2+ derived from cellular organelles. These results suggest that different calcium flux induced by IAA and zeatin plays a role in appropriate response resulting in increase of cell elongation or repression cell elongatoin.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.49-57
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• 1995

Protein kinase C (PK-C) represents a central element transducing signals generated by a broad range of pathways which produce the lipid second messenger sn-1,2-diacylglycerol (DAG) directly or indirectly. Many dominant oncogenes have proven to function, at least in part, through this pathway Likewise, this pathway is involved in expression of other aspects of the transformed phenotype, such as tumor invasion or multidrug resistance. As expected from its broad role in cell signaling, PK-C Is also important in a range of other physiological and pathophysiological processes, including inflammation, differentiation, and nerve function.

• Journal of applied mathematics & informatics
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• v.29 no.1_2
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• pp.427-442
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• 2011

Calcium is a vital second messenger for signal transduction in neurons. Calcium plays an important role in almost every part of the human body but in neuronal cytosol, it is of utmost importance. In order to understand the calcium signaling mechanism in a better way a finite element model has been developed to study the flow of calcium in two dimensions with time. This model assumes EBA (Excess Buffering Approximation), incorporating all the important parameters like time, association rate, influx, buffer concentration, diffusion constant etc. Finite element method is used to obtain calcium concentration in two dimensions and numerical integration is used to compute effect of time over 2-D Calcium profile. Comparative study of calcium signaling in two dimensions with time is done with other important physiological parameters. A MATLAB program has been developed for the entire problem and simulated on an x64 machine to compute the numerical results.

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.254-260
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• 1994

Magnaporthe grisea, a causal agent of blast, forms a specialized infection structure, an appressorium, to infect host. Hydrophobicity of contact surface and cAMP have been suggested as a primary environmental signal and a second messenger to trigger and mediate appressorium formation in this fungus, respectively. To generalize these factors in field isolates of M. girsea, twenty isolates originated from rice and other gramineous hosts were tested. Seventeen including rice and non-rice isolates formed appressoria on hydrophobic surface, but none of isolates formed appressoria on hydrophilic surface. Eighteen isolates formed appressoria on hydrophilic surface in the presence of IBMX, an inhibitor of phosphodiesterase, except two rice isolates. These results strongly support the hypothesis that appressorium formation by M. grisea is induced by hydrophobic hard surface and regulated by the endogenous level of cAMP in the cells. Understanding fungal development is not only of biological interest but provides new targets for novel disease control strategies.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.94-98
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• 1997

Ceramide. a product of sphingomyelin hydrolysis, has been proposed as a lipid second messenger mediating antiproliferative activation. In this study, we examined the role of the cell cycle-related proteins in the ceramide-mediated growth suppression. Treatment of U-937 cells with C$_2$-ceramide(N-acetylsphingosine) resulted in growth suppression in a time- and concentration dependent manner. Ceramide induced concentration dependent dephosphorylation of retinoblastoma gene product (Rb). Rb remains hypophosphorylated in synchronized cells even after serum stimulation in the presence of ceramide. Ceramide decreased the expression of cyclin D$_1$ and cyclin E levels. These results suggest that antiproliferative effect of ceramide is associated with hypophosphorylation of Rb and decreased expression of cyclin D1 and cyclin E.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.49-49
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• 2001

Sphingosine 1-phosphate is a metabolite of complex sphingolipids that acts as both a second messenger and as a high-affinity ligand for cell surface receptor. Since the possible involvement of sphingosine 1-phosphate has not been investigated in adipocyte, we examined the response of intracellular calcium ([Ca$^{2＋}$]$_{i}$) and intracellular cAMP ([cAMP]$_{i}$ and the effect of sphingosine 1-phosphate on adipocyte function using rat primary adipocyte.(omitted)ted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.216.2-216.2
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• 2003

Sphingolipids has been known to induce apoptosis, cell proliferation, differentiation and migration in a variety of cell types. Recently, its phosphate form was suggested that they may act both as an agonist ligand to SlPRs and a second messenger in intracellular action. Phytosphingosine(PHS) is not easily detected due to trace component of cellular lipids in mammalian and human tissues while this is a major sphingolipid in yeast and plants. We therefore developed highly sensitive and reproducible analytical method for PHS and its phosphate by oxalic acid bis(2,4,6-tri-chlorophenyl) ester(TCPO)-hydrogen peroxide(H$_2$O$_2$) chemiluminescence. (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.338.2-338.2
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• 2002

Ceramide is a lipid second messenger that is involved in apoptotic cell death. In this study, we show that p38 MAPK plays an important role in the regulation of ceramide-induced apoptosis. We found that SB203580, a p38 kinase inhibitor, blocked the effects of ceramide to induce Bax translocation to mitochondria, activation of caspase-3, and DNA fragmentation. Furthermore. expression of a dominant negative form of p38 MAPK suppressed ceramide-induced Bax translocation, suggesting that p38 kinase activity is essential for Bax translocation. (omitted)

• BMB Reports
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• v.54 no.3
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• pp.149-156
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• 2021

The well-known second messenger cyclic adenosine monophosphate (cAMP) regulates the morphology and physiology of neurons and thus higher cognitive brain functions. The discovery of exchange protein activated by cAMP (Epac) as a guanine nucleotide exchange factor for Rap GTPases has shed light on protein kinase A (PKA)-independent functions of cAMP signaling in neural tissues. Studies of cAMP-Epac-mediated signaling in neurons under normal and disease conditions also revealed its diverse contributions to neurodevelopment, synaptic remodeling, and neurotransmitter release, as well as learning, memory, and emotion. In this mini-review, the various roles of Epac isoforms, including Epac1 and Epac2, highly expressed in neural tissues are summarized, and controversies or issues are highlighted that need to be resolved to uncover the critical functions of Epac in neural tissues and the potential for a new therapeutic target of mental disorders.

• Archives of Plastic Surgery
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• v.49 no.3
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• pp.310-314
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• 2022

The emergence of vaccines for coronavirus disease 2019 (COVID-19) raises risk of possible adverse events from interaction between the vaccines and facial aesthetic care. A 47-year-old female with no medical comorbidities visited our emergency room due to midface painful swelling after 3 hours following receiving the second dose of the messenger RNA BNT162b2 COVID-19 vaccine. About 14 years ago, she underwent nonsurgical augmentation on the nasojugal groove with a calcium hydroxylapatite dermal filler. We performed incision and drainage under general anesthesia on the next day. During operation, yellowish pus-like materials bulged out. After an operation, we performed a combination therapy with antibiotics and methylprednisolone. Her symptoms improved day by day after surgery, and then a complete recovery was achieved at 3 weeks after the treatment. In conclusion, providers of aesthetic procedures are to be aware of the potential risks of such vaccines for patients who already had or seek to receive dermal filler injections.