• Journal of Korean Neurosurgical Society
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• v.42 no.6
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• pp.462-469
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• 2007

Objective : This study characterized the neurons in the lumbosacral cord that express phospho ERK (pERK) after distension or irritation of the bladder, and their relation to the vanilloid receptor 1 (VR1) positive primary afferents. Methods : Mechanical distension and chemical irritation of the bladder were induced by intravesical injection of the saline and mustard oil, respectively. Spinal neurons expressing pERK and the primary afferent fibers were characterized using multiple immunofluorescence for neurokinin 1 (NK1), neuronal nitric oxide synthetase (nNOS) and VR1. Results : Neurons in lamina I, medial dorsal horn (MDH), dorsal gray commissure (DGC) and sacral parasympathetic nucleus (SPN) were immunoreactive for pERK after either mechanical or chemical stimulation. The majority of pERK positive cells were positive for NK1 in lamina I and SPN, but not in the DGC. Most of pERK positive cells are not stained for nNOS except in a small population of the cells in the SPN and DGC. Contacts between perikarya and dendrites of pERK-positive cells and terminals of primary afferents expressing VR1 were identified in lamina I. lateral collateral path (LCP) and SPN. Conclusion : In this study, the lumbosacral neurons activated by mechanical and chemical stimulation of the urinary bladder were identified with expression of the pERK, and also provided the evidence that VR1-positive primary afferents may mediate the activation of these neurons.

• Journal of Life Science
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• v.16 no.6
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• pp.1066-1070
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• 2006

Smooth muscle cell (SMC) proliferation is important in the pathogenesis of vascular proliferative disorders. Understanding of the molecular mechanism underlying SMC growth after arterial injury would have therapeutic implications. Here we report that receptor activator of $NF-{\kappa}B$ ligand (RANKL), a member of tumor necrosis factor (TNF) family, promotes the proliferation of SMC, leading to decreased expression of p21 and enhancement of SMC growth. ERK and p38 phosphorylation was enhanced after RANKL treatment in SMC. Inhibition of ERK/p38 MAPK activity by PD98059/SB203580 completely abolished RANKL-induced proliferation of SMC, indicating ERK and p38 MAPK are essential for RANKL-induced SMC proliferation. Taken together, our findings demonstrate that RANK-RANKL-ERK/p38 pathway is important for proliferation of SMC and that these molecules may be the new therapeutic targets for the prevention of vascular diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2495-2499
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• 2015

Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3 (MEKK3) is an important serine/threonine protein kinase and a member of the MAPK family. MEKK3 can effectively activate the MEK/ERK signaling pathway and promote an autocrine growth loop critical for tumor genesis, cell proliferation, terminal differentiation, apoptosis and survival. To explore the relationship between MEKK3 and cell apoptosis, clinicopathology and prognosis, we characterize the expression of MEKK3, pERK and FoxP3 in the renal clear cell carcinoma (RCCC). Protein expression was detected by tissue microarray and immunochemistry in 46 cases of RCCC and 28 control cases. Expression levels of CD3+,CD3+CD4+,CD3+CD8+,CD4+CD25+, CD4+CD25+ FoxP3+ were assessed by flow cytometry and analyzed for their association with pathological factors, correlation and prognosis in RCCC. Expression of MEKK3, pERK and FoxP3 was significantly up-regulated in RCCC as compared to control levels (p<0.01), associated with pathological grade (p<0.05)and clinical stage (p<0.05). CD4+CD25+ Foxp3+ Treg cells were also significantly increased in RCCC patients (p<0.05). Cox multivariate regression analysis showed that MEKK3, pERK expression and patholigical stage were independent prognostic factors in patients with RCCC (p<0.05). MEKK3 can be used as an important marker of early diagnosis and prognostic evaluation in RCCC. It may be associated with imbalance of anti-tumor immunity and overexpression of pERK. Expression of MEKK3 and pERK are significantly increased in RCCC, with protein expression and clinical stage acting as independent prognostic factors.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.389-396
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• 2022

The increased expression of receptors for advanced glycation end-product (RAGE) is known as a key player in the progression of vascular remodeling. However, the precise signal pathways regulating RAGE expression in vascular smooth muscle cells (VSMCs) in the injured vasculatures are unclear. Given the importance of mitogen-activated protein kinase (MAPK) signaling in cell proliferation, we investigated the importance of MAPK signaling in high-mobility group box 1 (HMGB1)-induced RAGE expression in VSMCs. In HMGB1 (100 ng/ml)-stimulated human VSMCs, the expression of RAGE mRNA and protein was increased in association with an increase in AGE-induced VSMC proliferation. The HMGB1-induced RAGE expression was attenuated in cells pretreated with inhibitors for ERK (PD98059, 10 μM) and p38 MAPK (SB203580, 10 μM) as well as in cells deficient in ERK and p38 MAPK using siRNAs, but not in cells deficient of JNK signaling. In cells stimulated with HMGB1, the phosphorylation of ERK, JNK, and p38 MAPK was increased. This increase in ERK and p38 MAPK phosphorylation was inhibited by p38 MAPK and ERK inhibitors, respectively, but not by JNK inhibitor. Moreover, AGE-induced VSMC proliferation in HMGB1-stimulated cells was attenuated in cells treated with ERK and p38 MAPK inhibitors. Taken together, our results indicate that ERK and p38 MAPK signaling are involved in RAGE expression in HMGB1-stimulated VSMCs. Thus, the ERK/p38 MAPK-RAGE signaling axis in VSMCs was suggested as a potential therapeutic target for vascular remodeling in the injured vasculatures.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.4
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• pp.181-185
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• 2004

Extracellular regulated protein kinase1/2 (pERK1/2) is one of the major regulatory factors for transcription of the c-fos oncogene in neurons. The purpose of this study was to evaluate the expression of phosphorylated ERK1/2 within the vestibular nuclei (VN) of rats following acute arterial hypotension. Following the acute arterial hypotension induced by rapid hemorrhage, a significant number of pERK1/2-immunoreactive neurons appeared bilaterally in the caudal aspect of the medial and inferior VN. No labeling of pERK1/2 was observed in the lateral VN. The peak expression of pERK1/2 in these nuclei occurred within 5 min after hemorrhage. However, in bilaterally labyrinthectomized rats, the appearance of pERK1/2-immunoreactive neurons was eliminated in the VN. Western blot confirmed the effect of bilateral labyrinthectomy on pERK1/2 protein expression in the medial vestibular nucleus 5 min after hemorrhage. These results suggest that, following acute hypotension, afferent signals from the peripheral vestibular receptors are required for activation of ERK 1/2 in the VN.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.4
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• pp.353-358
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• 2014

Control of blood pressure is maintained by the interaction between the arterial baroreflex and vestibulosympathetic reflex during postural changes. In this study, the contributions of vestibular receptors and baroreceptors to the maintenance of blood pressure following acute hypotension were compared in terms of phosphorylated extracellular regulated protein kinase (pERK) expression in the nucleus tractus solitaries (NTS). Expression of pERK in the NTS was measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or sinoaortic denervation (SAD) 5, 10, 20, and 40 min following acute hypotension induced by sodium nitroprusside (SNP) infusion. Expression of pERK increased significantly in the NTS in the control group following SNP infusion, and the expression peaked at 10 min after SNP infusion. The number of pERK positive neurons increased following SNP infusion in BL, SAD, and BL+SAD groups, although the increase was smaller than in control group. The BL group showed a relatively higher reduction in pERK expression than the SAD group, and the pERK expression in the NTS was localized to the caudal portion of the nuclei in the BL and SAD groups. These results suggest that the vestibular receptors may play a key role in maintaining blood pressure following acute hypotension; thus, the vestibular system may contribute to compensate for orthostatic hypotension.

• Childhood Kidney Diseases
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• v.21 no.1
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• pp.1-7
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• 2017

Mitogen-activated protein kinases (MAPKs) play important roles in various cellular functions including proliferation, differentiation, and apoptosis. We showed that MAPKs are developmentally regulated in the rat kidney. p38 MAPK (p38) and extracellular signal-regulated kinase (ERK) were strongly expressed in the fetal kidney, whereas c-Jun N-terminal kinase (JNK) was detected predominantly in the adult kidney. The inhibition of p38 or ERK in organ culture resulted in reduced nephron formation with or without reduced kidney size. On the other hand, persistent fetal expression pattern of MAPKs, i.e., upregulation of p38 and ERK and downregulation of JNK, was observed in the cyst epithelium of human renal dysplasia, ovine fetal obstructive uropathy, and pcy mice, a model of polycystic kidney disease. Furthermore, activated p38 and ERK induced by cyclic stretch mediated proliferation and $TGF-{\beta}1$ expression in ureteric bud cells, probably leading to cyst formation and dysplastic changes. Inhibition of ERK slowed the disease progression in pcy mice. Finally, ERK and p38 were inactivated in the early embryonic kidney subjected to maternal nutrient restriction, characterized by reduced ureteric branching and nephron number. Thus, MAPKs mediate the development of normal and diseased kidney. Their modulation may result in novel therapeutic strategies against developmental abnormalities of the kidney.

• BMB Reports
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• v.41 no.3
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• pp.242-247
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• 2008

MSS, a comprising mixture of maesil (Prunus mume Sieb. et Zucc) concentrate, disodium succinate and Span80 (3.6 : 4.6 : 1 ratio) showed a significant improvement of memory when daily administered (460 mg/kg day, p.o.) into the normal rats for 3 weeks. During the spatial learning of 4 days in Morris water maze test, both working memory and short-term working memory index were significantly increased when compared to untreated controls. We investigated a molecular signal transduction mechanism of MSS on the behaviors of spatial learning and memory. MSS treatment increased hippocampal mRNA levels of NR2B and TrkB without changes of NR1, NR2A, ERK1, ERK2 and CREB. However, the protein levels of pERK/ERK and pCREB/CREB were all significantly increased to $1.5{\pm}0.17$ times. These results suggest that the improving effect of spatial memory for MSS is linked to MAPK/ERK signaling pathway that ends up in the phosphorylation of CREB through TrkB and/or NR2B of NMDA receptor.

• Molecules and Cells
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• v.39 no.3
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• pp.266-279
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• 2016

The mechanism by which 12-O-tetradecanoylphorbol-13-acetate (TPA) bypasses cellular senescence was investigated using human diploid fibroblast (HDF) cell replicative senescence as a model. Upon TPA treatment, protein kinase C (PKC) ${\alpha}$ and $PKC{\beta}1$ exerted differential effects on the nuclear translocation of cytoplasmic pErk1/2, a protein which maintains senescence. $PKC{\alpha}$ accompanied pErk1/2 to the nucleus after freeing it from $PEA-15pS^{104}$ via $PKC{\beta}1$ and then was rapidly ubiquitinated and degraded within the nucleus. Mitogen-activated protein kinase docking motif and kinase activity of $PKC{\alpha}$ were both required for pErk1/2 transport to the nucleus. Repetitive exposure of mouse skin to TPA downregulated $PKC{\alpha}$ expression and increased epidermal and hair follicle cell proliferation. Thus, $PKC{\alpha}$ downregulation is accompanied by in vivo cell proliferation, as evidenced in 7, 12-dimethylbenz(a)anthracene (DMBA)-TPA-mediated carcinogenesis. The ability of TPA to reverse senescence was further demonstrated in old HDF cells using RNA-sequencing analyses in which TPA-induced nuclear $PKC{\alpha}$ degradation freed nuclear pErk1/2 to induce cell proliferation and facilitated the recovery of mitochondrial energy metabolism. Our data indicate that TPA-induced senescence reversal and carcinogenesis promotion share the same molecular pathway. Loss of $PKC{\alpha}$ expression following TPA treatment reduces pErk1/2-activated SP1 biding to the $p21^{WAF1}$ gene promoter, thus preventing senescence onset and overcoming G1/S cell cycle arrest in senescent cells.

• Journal of Pharmacopuncture
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• v.6 no.2
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• pp.77-90
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• 2003

The purpose of this study was to investigate the effect of Bee Venom on the lipopolysaccharide(LPS), sodium nitroprusside(SNP), hydrogen peroxide($H_2O_2$)-induced expressions of cyclooxygenase-2(COX-2), p38, jun N-terminal Kinase(JNK) and extra-signal response kinase(ERK) in RAW 264.7 cells, a murine macrophage cell line. Method : The expressions of COX-2, p38, JNK and ERK were determined by western blotting with corresponding antibodies. Results : 1. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited significantly LPS and SNP-induced expression of COX-2 compared with control, respectively. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited insignificantly $H_2O_2$-induced expression of COX-2 compared with control, respectively. 2. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited significantly LPS, SNP and $H_2O_2$-induced expression of p38 compared with control, respectively. 3. The 1 and $5\;{\mu}g/ml$ of bee venom inhibited significantly SNP-induced expression of JNK compared with control, respectively. All of bee venom inhibited insignificantly LPS and $H_2O_2$-induced expression of JNK compared with control, respectively. 4. The $5\;{\mu}g/ml$ of bee venom inhibited significantly SNP-induced expression of ERK, the $0.5\;{\mu}g/ml$ of bee venom increased significantly $H_2O_2$-induced expression of ERK compared with control. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited insignificantly LPS-induced expression of ERK compared with control, respectively.