Protein Expression Of Extracellular Signal-regulated Kinase Research Articles

Xiebai Zengye decoction improves respiratory function and attenuates inflammation in juvenile rats with postinfection cough via regulating ERK signaling pathway.

This study aimed to determine the effects of Xiebai Zengye decoction (XBZY)on airway inflammation and respiratory function in rats with postinfectious cough (PIC),and its regulatory effects on the extracellular signal-regulated kinase (ERK)signaling pathway. Compared with the normal group, the rats from thePIC group had significantly shortened expiratory time (TE)and enhanced pause (EEP),increased resistance (RT),and enhanced pause (Penh), along with increased levels of serum interleukin-4 (IL-4)and IL-6,and decreased levels of IL-10. The lung and colon tissues of rats from the PIC group showed histopathological changes, including inflammatory cell infiltration, damaged mucosal epithelium, and crypt structure, with significantly increased ERK mRNA and protein expression levels. Treatment with XBZY and montelukast sodium (MAS)improved the respiratory function and serum cytokine levels, reduced tissue inflammation, and decreased ERK mRNA and protein expression levels in the lung and colon tissues. In the lung tissues, XBZY treatment significantly decreased the expression of phosphorylated-ERK (p-ERK)protein, as well as p-MEK1/2, p-ERK1/2, and p-c-Fos proteins, while in the colon tissues, XBZY significantly decreased the expression of p-ERK1/2and p-c-Fos proteins. However, MAS treatment only showed significant improvement in the lung tissue inflammation score, and the expression level of p-ERK protein in the lung tissue was decreased. In conclusion, the present study suggests that XBZY has a potential therapeutic effect on PIC by improving respiratory function and attenuating inflammation, and this effect may be associated with the inhibition of the ERK signaling pathway. These findings could provide a new direction for the development of treatments for PIC. However, further research is needed to elucidate the underlying molecular mechanisms of XBZY and to confirm its safety and efficacy in clinical trials.

Silk fibroin-hydroxyapatite scaffolds promote the proliferation of adipose-derived mesenchymal stem cells by activating the ERK signal.

Adipose-derived mesenchymal stem cell (Ad-MSC) with capacities of releasing trophic factors and chondrogenic differentiation was a promising candidate for tracheal reconstruction. Silk fibroin (SF)- hydroxyapatite (HA) scaffolds were fabricated by the freeze-drying method. And Ad-MSCs were co-cultured on the scaffolds for 14days in vitro. The role of the SF-HA scaffold in regulating the adhesion, growth, and proliferation of Ad-MSCs, and its potential mechanisms were investigated. The identity of Ad-MSCs was confirmed by cell morphology, surface markers, and differentiation characteristics. Cell proliferation, viability, and morphology were observed via CCK-8, live/dead assay, and scanning electron microscopy (SEM). Gene mRNA and protein levels were examined using quantitative real-time polymerase chain reaction and western blotting, respectively. SF-HA scaffolds showed excellent properties of promoting Ad-MSCs adhesion, growth, and proliferation for at least 14days. In the CCK-8 assay, the relative OD value of Ad-MSCs cultured on SF-HA scaffolds increased (p < 0.001). Furthermore, live/dead staining showed that the fluorescent coverage increased with time (p < 0.05). SEM also showed that 3days after inoculation, the coverage of Ad-MSCs on the SF-HA scaffolds was 78.15%, increased to 92.91% on day 7, and reached a peak of 94.38% on day 14. Extracellular signal-regulated kinase (ERK) mRNA and phosphorylated ERK (pERK) protein expression increased at day 3 (p < 0.05), followed by a significant decline at day 7 (p < 0.05). And ERK mRNA expression was positively correlated with Ad-MSCs proliferation (p < 0.05). In summary, the SF-HA scaffold co-cultured with Ad-MSCs is a promising biomaterial for tracheal repair by activating the ERK signal pathway.

Expression of Tyrosine Kinase Receptor 2 in Oral Squamous Cell Carcinoma and the Effect on Cell Proliferation and Migration and Epithelial-Mesenchymal Transition Process

To study the expression of tyrosine kinase receptor 2 (Tie2) in oral squamous cell carcinoma (OSCC) and its effect on cell proliferation and migration and the epithelial-mesenchymal transition (EMT) process. Immunohistochemistry (IHC) tests were conducted to examine the expression of Tie2 in OSCC tissues and normal oral mucosa tissues. Western blot was performed to examine the expression of Tie2 in dysplastic oral keratinocyte (DOK) cell line and OSCC cell lines, and the cell line with high Tie2 expression was selected as the experimental cell line. The Tie2-silenced lentiviral vector was successfully transfected onto the experimental cell line for subsequent experiments. Cell proliferation and cloning abilities were examined with CCK-8 and clone formation assays. Cell migration ability was examined with scratch and Transwell assays. The remodeling ability of cytoskeletal F-actin and the expressions of E-cadherin and N-cadherin were examined with confocal laser scanning microscope. Western blot was performed to examine the expression of EMT-related signature proteins, including E-cadherin, N-cadherin, and vimentin, and the expression of the protein kinase B (AKT) and extracellular signal-regulated kinase (ERK). IHC results showed that the Tie2-positive rate of the OSCC group (74.5%) was significantly higher than that of the control group (19.4%) ( P<0.0001). The expression of Tie2 was higher in HSC-4 and SCC-9 cell lines compared to that in DOK cells. The lentiviral shRNA-162 group showed the best silencing effect, which was used as the experimental group and applied in subsequent experiments. Compared with those of the control group, the proliferation, cloning and migration capacities of the cells of the experimental group were significantly reduced. Furthermore, the green fluorescence intensity of the cytoskeleton F-actin was reduced, the number of filamentous pseudopods at the leading edge of the cells decreased and their length was shortened, and the expression of E-cadherin was significantly increased, while the expression of N-cadherin and vimentin was significantly reduced in the experimental group in comparison with those of the control group. The expression of p-AKT and p-ERK proteins decreased, while AKT and ERK protein expression increased. Tie2 was highly expressed in most OSCC cells. Silencing Tie2 can inhibit the proliferation, cloning, and migration ability of OSCC cells, inhibit F-actin remodeling, and alter the expression of its EMT-related signature proteins by regulating AKT and ERK signaling pathway, which suggests that Tie2 may be involved in the growth, metastasis and EMT process of OSCC.

Effect of arsenic and lead on glucose level and expression of ERK in air-breathing catfish, Heteropneustes fossilis

Heavy metal contaminations may have devastating effects on the ecological balance of the environment and diversity of aquatic organisms. Furthermore, they cause great threat to the Indian aquatic ecosystem. In this study, we analyzed the effect of arsenic (As) and lead (Pb) on the blood glucose level and their possible involvement in the mitogen-activated protein kinase (MAPK) pathway in liver and muscle tissues of Heteropneustes fossilis. The catfish, H. fossilis, were exposed to an acute (35.09 ppm As2O3 and 66.20 ppm PbCl2 for ~96 h) and chronic (LC50/20th ppm of both As2O3 and PbCl2 for ~30 d) concentration of As and Pb. Thereafter, the blood glucose level and the extracellular signal-regulated protein kinase (ERK) expression level in liver and muscle tissues of the fish were analyzed. It was found that As and Pb caused hyperglycemia in H. fossilis. Both on acute and chronic treatment with As and Pb, no significant change in p-ERK1/2 expression level was found in the muscle tissue of H. fossilis, whereas, in the liver tissue, the p-ERK1/2 expression level showed a significant increase in both acute (96 h) and chronic treatment (10 d and 30 d) of As and Pb. Therefore, it can be concluded that As and Pb could be highly toxic to the aquatic fauna, which could be a potential threat to human health as well.

Calcium-sensing receptor promotes calcium oxalate crystal adhesion and renal injury in Wistar rats by promoting ROS production and subsequent regulation of PS ectropion, OPN, KIM-1, and ERK expression

Objectives To explore the mechanism of calcium-sensing receptors (CaSRs) during the development of nephrolithiasis. Materials and methods Wistar rats were treated with ethylene glycol to induce calcium oxalate crystallization, and gadolinium chloride (GdCl3, an agonist of CaSR) and NPS 2390 (an antagonist of CaSR) were added. Oxidative stress (OS) and calcium oxalate crystals in the kidney were observed. CaSR expression and the expression of extracellular signal-regulated protein kinase (ERK), OPN, and KIM-1 were determined by western blotting. In addition, renal tubular epithelial cells were isolated from the kidney to observe phosphatidylserine (PS) ectropion using flow cytometric analysis. Various biochemical parameters were assessed in serum and urine at the end of the experiment. Results Calcium oxalate increased OS, crystal adhesion, PS ectropion, and the expression of CaSR and ERK, OPN, and KIM-1 in vivo. In addition, lower levels of urine citrate as well as increased serum creatinine and urea levels were observed after treatment with calcium oxalate (p < .05). Compared with calcium oxalate treatment alone, the above deleterious changes were further significantly confirmed by GdCl3 but were reversed by NPS-2390. However, urine calcium excretion was decreased after ethylene glycol treatment but was significantly reduced by NPS 2390 and increased by GdCl3 (p < .05). Conclusions The results suggest that CaSR might play significant roles in the induction of nephrolithiasis in rats by regulating reactive oxygen species (ROS) and PS ectropion and the composition of urine, OPN, KIM-1, and ERK expression.

Downregulation of miR-21 promotes tibial fracture healing in rabbits through activating ERK pathway.

The aim of this study was to investigate the effect of micro ribonucleic acid (miR)-21 on tibial fracture healing in rabbits by regulating the extracellular signal-regulated kinase (ERK) signaling pathway, and to explore its possible underlying mechanism. A total of 15 healthy male rabbits were randomly divided into three groups, including: model group A (fracture group, n=5), model group B (fracture treatment group, n=5), and model group C (miR-21 siRNA + treatment group, n=5). Fracture healing was observed by imaging. The content of the serum collagen I and collagen II in rabbits was detected via enzyme-linked immunosorbent assay (ELISA). The morphology of bone tissues was observed via staining. Moreover, the expressions of ERK, transforming growth factor-β1 (TGF-β1), and Smad in osteoblasts of tibia were observed via Western blotting and Reverse Transcription-Polymerase Chain Reaction (RT-PCR), respectively. There was bony callus formation in group B and C when compared with group A. Compared with group B, bony callus formation was significantly accelerated in group C, while healing cycle was shortened. Hematoxylin-eosin (HE) staining and Masson staining indicated that compared with group A, group C had more fibrous calluses, new capillaries, and fibroblasts in tissues. Meanwhile, group C exerted better maturity of collagen tissues and higher osteoid content at 20 d after modeling. Compared with group C, there were more osteoid tissues with poor maturity in group B. Meanwhile, intramembranous bone formation was deformed, and collagen content was remarkably lower in group B. The content of serum collagen I and collagen II remarkably increased in group B compared with group A (p<0.05). However, it was significantly upregulated in group C compared with group B, showing statistically significant differences (p<0.05). According to the results of Western blotting, the protein expressions of TGF-β1, Smad, and ERK in osteoblasts were significantly upregulated in group B when compared with those in group A (p<0.05). However, they increased remarkably in group C when compared with group B (p<0.05). Besides, RT-PCR results revealed that the messenger RNA (mRNA) expressions of TGF-β1, Smad, and ERK in osteoblasts were significantly higher in group B than those in group A (p<0.05). However, they were markedly raised in group C in comparison with group B (p<0.05). Down-regulation of miR-21 promotes tibial fracture healing in rabbits by activating the ERK signaling pathway.

Alteration in cardiac PI3K/Akt/mTOR and ERK signaling pathways with the use of growth hormone and swimming, and the roles of miR21 and miR133.

Athletes misuse recombinant human growth hormone (r-hGH) to enhance their performance. Although r-hGH is known to increase cardiac hypertrophy, the underlying molecular mechanism remains unclear. The aim of the present study was to investigate the role of r-hGH in cardiac intracellular signaling pathways and of miR-21 and miR-133 expression in rat hearts during exercise. A total of 36 adult male Sprague-Dawley rats were divided into sedentary control (SC, n=9), swimming exercise (SE, n=8), r-hGH (GH, n=10) and swimming exercise plus r-hGH (SE-GH, n=9) groups. The exercise groups completed a 1-h swimming exercise 5 times a week for 8 weeks. Subcutaneous r-hGH was administered as 0.3 mg/kg/day. Phosphoinositide-3-kinase (PI3K), serine/threonine protein kinase 1 (AKT1), extracellular signal-regulated kinase (ERK), microRNA (miR)-21 and miR-133 expression was evaluated in ventricular muscle by real-time quantitative polymerase chain reaction. Protein expression of PI3K, AKT1, ERK and mechanistic target of rapamycin (mTOR) was also assessed by immunohistochemistry. Statistical differences were analyzed by two-way ANOVA. PI3K and AKT1 expression and the gene and protein levels was notably increased in the SE-GH group compared with in SC ventricular tissues (P<0.05). mTOR protein expression was higher in the GH, SE and SE-GH groups compared with in the SC group (P<0.05, <0.05 and <0.001, respectively). ERK gene/protein expression was similar across all groups. miR-21 and miR-133 levels in ventricular muscle were higher in the SE and GH groups than those in the SC group. In summary, growth hormone application coupled with swimming exercise appeared to affect the PI3K/AKT/mTOR signaling pathway in the left ventricular tissue of rats; however, ERK signaling pathway appeared inactive in physiological left ventricular hypertrophy caused by swimming and GH administration over 8 weeks. Furthermore, GH treatment resulted in increased miR-21 and miR-133 expression. Future study by our group will aim to assess the effects of higher dose GH treatment.

OR-034 The parvalbumin positive neuron involved the regulation of motor cortex excitability in the exercise-induced fatigue

Objective Objective:Cortical parvalbumin-expressing inhibitory neurons(PV) control the activity of excitatory neurons and regulate their spike output. The present experiment is to determine the role of PV neuron in the reglution of excitability of primary motor cortex (M1) during the exercise-induced fatigue and possible molecular mechanism.&#x0D; Methods Methods: Male Wistar rats randomly divided into control group(C),exhaustive exercise group(E) and repeated exhaustive exercise group(RE). The gradually increasing load treadmill exercise-induced fatigue model was employed in the Group E and RE.The in vivo multi-channel recording methods was used for recording the neuronal electrophysiological activities of primary motor cortex.To observe the neuron firing rate changes during the rest state,immediately after exhausted exercise and after repeated exhaustive exercise.We also detected the expression of PV positive neurons in the primary motor cortex by the immunofluorescence method. The western blot method was used to determine the expression of calmodulin-dependent protein kinase II (CaMKII)、phosphorylated calmodulin-dependent protein kinase II( pCaMKII) and extracellular signal regulated kinase (ERK) in the primary motor cortex.&#x0D; Results Results：The electrophysioligical results indicated that the neuron firing rate after repeated exhausted excise the neuron firing rate significantly decreased compared with the rest state (P&lt;0.05),but have no significantly changes as compared with exhausted excise;The expression of PV positive neurons in the group of E and RE significantly increased compared with the group C(P&lt;0.01);The western blot results indicated that the protein expression of ERK in group REsignificantly decreased compared with group C, the pCaMKII expression of group RE decreased,but have no statistical difference.&#x0D; Conclusions Conclusion: After exercise-indued fatigue ,the increase of PV positive neuron maybe one reason for the excitability changes in primary motor cortex.the alteraions in the electrical signal may be participate in the regluation of exercise-induced fatigue. pCaMKII and ERK signal pathway may invloved in the molecular mechanism of exercise-induced fatigue.

Shuyu capsules relieve liver-qi depression by regulating ERK-CREB-BDNF signal pathway in central nervous system of rat.

The purpose of this study was to investigate the possible therapeutic mechanism of Shuyu capsules in liver-qi depression. Liver-qi depression rats were prepared based on chronic unpredictable mild stress (CUMS) and delayed constraint. Rats were gavaged with Shuyu capsule, fluoxetine, Radix Bupleuri and Radix Paeoniae Alba to constrct rat models. Body weight test, sucrose preference test and open-field test were applied to test rat models. Western blot analysis and quantitative real-time PCR was applied to determine the relative expression of extracellular signal-regulated protein kinase (ERK), cyclic AMP response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in hippocampus and frontal lobe tissues. ELISA was used to detect the content of BDNF in serum. Body weight, sugar intake and total distance were significantly decreased in depression group compared with control. The four drugs significantly increased levels of these factors. Compared with control group, ERK, CREB and BDNF expression were significantly decreased in depression group in both hippocampus and frontal lobe tissues at both mRNA and protein level. Shuyu capsule and fluoxetine group showed a significant increase in the expression of ERK, CREB and BDNF at mRNA, p-ERK and p-BDNF at protein level. Compared with Radix Paeoniae Alba, Radix Bupleuri were better in the rescue of ERK, CREB and BDNF expression. In conclusion, the pathogenesis of liver-qi depression associated with lower expression of ERK, CREB and BDNF in hippocampus and frontal. Shuyu capsule and main constitution alleviated the depressive-like behaviors and reversed the disruptions of the p-ERK, p-CREB and BDNF in stressed rats.

Protective effect of glycyrrhizin on myocardial ischemia/reperfusion injury-induced oxidative stress, inducible nitric oxide synthase and inflammatory reactions through high-mobility group box 1 and mitogen-activated protein kinase expression.

Glycyrrhizin, which is a type of perennial leguminous caudex, has been used in various Asian countries, including P.R. China, India and Japan, for thousands of years. The present study was designed to investigate the protective effect of glycyrrhizin on myocardial ischemia/reperfusion (I/R) injury through oxidative stress, inducible nitric oxide synthase (iNOS), and inflammatory reactions via high-mobility group box 1 (HMGB1) and mitogen-activated protein kinase (MAPK) expression. Sprague-Dawley rats were divided into five groups: Sham; myocardial I/R injury + non-treated; myocardial I/R injury + 2 mg/kg glycyrrhizin; myocardial I/R injury + 4 mg/kg glycyrrhizin; and myocardial I/R injury + 10 mg/kg glycyrrhizin. Pre-treatment with glycyrrhizin significantly reduced infarct size and inhibited creatine kinase, creatine kinase-MB, lactate dehydrogenase and cardiac troponin T activities in rats with myocardial I/R injury. Furthermore, glycyrrhizin treatment significantly suppressed oxidative stress, iNOS protein expression and inflammatory reactions in rats with myocardial I/R injury. Additionally, treatment with glycyrrhizin significantly decreased the release of HMGB1 from the cerebral cortex into the serum in rats with myocardial I/R injury. Notably, glycyrrhizin significantly suppressed p-ERK, p-p38 MAPK and p-c-Jun N-terminal kinase protein expressions, and promoted extracellular signal-regulated kinase protein expression in rats with myocardial I/R injury. Collectively, the present study indicates that the protective effect of glycyrrhizin may reduce myocardial I/R injury through oxidative stress, iNOS and inflammatory reactions, via HMGB1 and MAPK expression.

Basic fibroblast growth factor increases IFT88 expression in chondrocytes.

Intraflagellar transport protein 88 (IFT88) is protein crucial for the assembly and maintenance of primary cilia in chondrocytes. Primary cilia regulate mechanical and chemical signals in chondrocytes; however, the effects of cytokines on IFT88 expression and cilia formation and maintenance remain to be elucidated. Therefore, the role of basic fibroblast growth factor (bFGF) on IFT88 expression were examined in the ATDC5 murine chondrocytic line, in order to investigate the signaling pathways involved in this process. bFGF treatment upregulated IFT88 expression in a dose- and time-dependent manner in ATDC5 cells. The effects of bFGF on IFT88 protein expression were suppressed in the presence of the extracellular signal-regulated protein kinase (ERK) inhibitor PD0325901 and the FGF receptor inhibitor BGJ398. In addition, treatment with IFT88-trageting small interfering (si)RNA downregulated the protein expression of IFT88 and ERK, thus suggesting that the ERK signaling pathway may be involved in the regulation of IFT88 expression in ATDC5 cells. bFGF treatment increased the number of ciliated ATDC5 cells and primary cultured chondrocytes. Downregulation of IFT88 expression by PD0325901, BGJ398, or IFT88-targeting siRNA was revealed to reduce the number of ciliated cells. bFGF also upregulated the mRNA and protein expression of IFT88 in primary cultured chondrocytes. In conclusion, the findings of the present study suggested that bFGF may enhance the expression of IFT88, and promote primary cilia development, through the mitogen-activated protein kinase/ERK-mediated pathway in chondrocytes.

Osthole, a Coumadin Analog from Cnidium monnieri (L.) Cusson, Ameliorates Nucleus Pulposus-Induced Radicular Inflammatory Pain by Inhibiting the Activation of Extracellular Signal-Regulated Kinase in Rats

Aim: This study was aimed at assessing the role of extracellular signal regulated kinase (ERK) in mechanical allodynia resulting from lumbar disc herniation (LDH) and exploring the osthole's anti-nociceptive effect on ERK activation. Methods: Radicular pain was generated by applying nucleus pulposus (NP) to the L₅ dorsal root ganglion (DRG). Allodynia was measured using Von Frey filaments to calculate the mechanical pain threshold. Phosphorylated ERK and total ERK protein in the lumbar spinal dorsal horn was detected by using the Western blot technique. Cyclooxygenase 2 (COX-2) mRNA was assessed by real-time reverse-transcription polymerase chain reaction. Results: The application of NP to L₅ DRG induced mechanical hypersensitivity which lasted for at least 28 days, and a significant increase of ERK phosphorylation in the ipsilateral spinal dorsal horn from postoperative day (POD) 1 to POD 21. ERK inhibitor attenuated NP-induced hyperalgesia compared to the dimethyl sulfoxide-(vehicle control) administered group (p < 0.05). Epidural treatment with osthole could ameliorate NP-evoked hyperalgesia by suppressing the activation of ERK rather than decreasing the expression of ERK protein. Osthole could also inhibit the increased expression of COX-2 mRNA in spinal dorsal horn, which was a known downstream effect of ERK signaling pathway. Conclusions: Our results suggest that ERK activation in the spinal dorsal horn plays a vital role in NP-evoked hyperalgesia. Osthole exerts analgesic effect on radicular inflammatory pain in LDH rat model, by down-regulating the mRNA expression of the target gene of COX-2 via inhibiting ERK activation in the spinal dorsal horn.

Cobra neurotoxin produces central analgesic and hyperalgesic actions via adenosine A1 and A2A receptors.

Cobra neurotoxin, a short-chain peptide isolated from snake venom of Naja naja atra, showed both a central analgesic effect and a hyperalgesic effect in mice tests. In order to explore mechanisms, a hypothesis is put forward that cobra neurotoxin takes effect through adenosine receptor pathway. The central effects of cobra neurotoxin were evaluated using the hot plate test (a model of acute pain) and the spinal cord injury (a model of central pain) in mice and using A1 receptor antagonist (DPCPX) and A2A receptor antagonist (ZM241385); behaviors were scored and signal molecules such as reactive oxygen species and adenosine triphosphate levels and mitogen-activated protein kinases/extracellular signal-regulated protein kinase expression were measured. Low dose of cobra neurotoxin (25 µg/kg) had analgesic effects which were inhibited by DPCPX, while high dose of cobra neurotoxin (100 µg/kg) had hyperalgesic effects which were blocked by ZM241385. Cobra neurotoxin reduced reactive oxygen species and increased adenosine triphosphate in brain tissues, and extracellular signal-regulated protein kinase expression was markedly inhibited by cobra neurotoxin. Cobra neurotoxin may take effect through mitogen-activated protein kinases/extracellular signal-regulated protein kinase pathway inhibition by activating adenosine A1Rs and cause changes of reactive oxygen species and adenosine triphosphate through feedback mechanisms. Overdose cobra neurotoxin further activates the adenosine A2ARs to generate pain sensitization. This research proposes a new central analgesic mechanism of cobra neurotoxin and discloses dual regulation of pain.

Calcium Oxalate Induces Renal Injury through Calcium-Sensing Receptor.

Objective. To investigate whether calcium-sensing receptor (CaSR) plays a role in calcium-oxalate-induced renal injury. Materials and Methods. HK-2 cells and rats were treated with calcium oxalate (CaOx) crystals with or without pretreatment with the CaSR-specific agonist gadolinium chloride (GdCl3) or the CaSR-specific antagonist NPS2390. Changes in oxidative stress (OS) in HK-2 cells and rat kidneys were assessed. In addition, CaSR, extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal protein kinase (JNK), and p38 expression was determined. Further, crystal adhesion assay was performed in vitro, and the serum urea and creatinine levels and crystal deposition in the kidneys were also examined. Results. CaOx increased CaSR, ERK, JNK, and p38 protein expression and OS in vitro and in vivo. These deleterious changes were further enhanced upon pretreatment with the CaSR agonist GdCl3 but were attenuated by the specific CaSR inhibitor NPS2390 compared with CaOx treatment alone. Pretreatment with GdCl3 further increased in vitro and in vivo crystal adhesion and renal hypofunction. In contrast, pretreatment with NPS2390 decreased in vitro and in vivo crystal adhesion and renal hypofunction. Conclusions. CaOx-induced renal injury is related to CaSR-mediated OS and increased mitogen-activated protein kinase (MAPK) signaling, which subsequently leads to CaOx crystal adhesion.

Aspirin Inhibits LPS-Induced Expression of PI3K/Akt, ERK, NF-κB, CX3CL1, and MMPs in Human Bronchial Epithelial Cells.

This study focused on the effects of aspirin on lipopolysaccharide (LPS)-induced expression of phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt), extracellular signal-regulated protein kinase (ERK), nuclear factor-κB (NF-κB), CX3CL1, and MMPs in human bronchial epithelial cells. Human bronchial epithelial cells were seeded in six-well plates. After 24h, the cells were classified into six groups: control blank (CK) group; LPS group; PD98059 (ERK inhibitor) (PD) group, treated with LPS + ERK inhibitor; LY294002(PI3K/Akt inhibitor) (LY) group, treated with LPS + PI3K/Akt inhibitor; Aspirin (Asp) group, treated with LPS + aspirin; and Pyrrolidinedithiocarbamic acid (PDTC) group, treated with LPS + NF-κB inhibitor. After 4-h treatment, the cells were harvested. Western blot analysis was performed to detect the expression of PI3K/Akt, ERK, NF-κB, and CX3CL1. Real-time quantitative PCR (RT-qPCR) was used to determine the gene expression of MMP-7, MMP-9, and MMP-12. Compared to the CK group, expression of PI3K/Akt, ERK, NF-κB, and CX3CL1 was significantly increased in the LPS group (P < 0.05). When compared to the LPS group, expression of PI3K/Akt, ERK, NF-κB, and CX3CL1 was significantly decreased in the PD group, PDTC group, and Asp group (P < 0.05). In addition, expression of NF-κB in the LY group was significantly reduced by comparison with the LPS group (P < 0.05). RT-qPCR: When compared to the LPS group, expression of MMP-7 and MMP-12 was significantly decreased in Asp group (P < 0.05). Expression of MMP-12 was significantly reduced in LY group (P < 0.05). LPS-ERK, NF-κB-PI3K/Akt, and CX3CL1 signal pathways exist in human bronchial epithelial cells. The PI3K/Akt inhibitor repressed expression of MMP-12. Aspirin inhibited LPS-induced expression of PI3K, Akt, ERK, NF-κB, CX3CL1, MMP-7, and MMP-12 in human bronchial epithelial cells.

Role of spinal MCP-1-ERK-KIF17/NR2B signaling pathway in maintenance of type 2 diabetic neuropathic pain in rats

Objective To explore the role of spinal monocyte chemoattractant protein-1 (MCP-1) -extracellular signal-regulated protein kinase (ERK) -kinesin superfamily motor protein 17 (KIF17) /N-methyl-D-aspartate receptor subunit 2B (NR2B) signaling pathway in the maintenance of type 2 diabetic neuropathic pain (DNP) in rats. Methods Type 2 diabetes mellitus was induced by a high-fat and high-sucrose diet and intraperitoneal streptozotocin (STZ) 35 mg/kg, and confirmed by fasting blood glucose level≥16.7 mmol/L 3 days later in male Sprague-Dawley rats aged 6 weeks.Type 2 DNP was confirmed when the mechanical paw withdrawal threshold (MWT) and thermal paw withdrawl latency (TWL) measured on day 14 after STZ administration decreased to < 80% of the baseline value.The rats with type 2 DNP were randomly divided into 4 groups (n=36 each) using a random number table: type 2 DNP group (group DNP) , type 2 DNP + MCP-1 neutralizing antibody group (group DM) , type 2 DNP + ERK inhibitor group (group DE) and type 2 DNP + dimethyl sulfoxide group (group DD) . In DM, DE and DD groups, 0.1 ng/μl MCP-1 neutralizing antibody 10 μl, 0.5 μg/μl U0126 10 μl and 5 % dimethyl sulfoxide 10 μl were injected intrathecally, respectively, once a day for 14 consecutive days starting from 14 days after administration of STZ.Another 36 normal rats fed a common forage diet were adopted as control group (group C) . MWT and TWL were measured before STZ injection and at 1, 3, 7 and 14 days after STZ injection (T0-4) . Nine rats were sacrificed after measurement of pain thresholds at T1-4, and the lumbar segments (L4-6) of the spinal cord were removed for determination of the expression of phosphorylated ERK (p-ERK) , KIF17 and phosphorylated NR2B (p-NR2B) by Western blot. Results Compared with group C, the MWT was significantly decreased, the TWL was shortened, and the expression of p-ERK, KIF17 and p-NR2B was up-regulated at T1-4 in DNP, DM, DE and DD groups.Compared with group DNP, the MWT at T3-4 in group DM and at T2-4 in group DE was significantly increased, the TWL at T3-4 in group DM and at T2-4 in group DE was prolonged, and the expression of p-ERK, KIF17 and p-NR2B was down-regulated at T2-4 in DM and DE groups, and no significant changes were found in the parameters mentioned above in group DD. Conclusion Spinal MCP-1-ERK-KIF17/NR2B signaling pathway is involved in the maintenance of type 2 DNP in rats. Key words: Diabetes mellitus, type 2; Neuropathic pain; Chemokine CCL2; Extracellular Signal-Regulated MAP Kinases; Receptors, N-Methyl-D-Aspartate; Kinesin; Spinal cord

Taurine Supplementation Enhances Insulin Secretion Without Altering Islet Morphology in Non-obese Diabetic Mice.

Taurine (TAU) is a sulfated amino acid that improves pancreatic islet function and regulates β-cell mass in pre- and diabetic states. We herein analyzed glucose homeostasis and islet morphofunction in non-obese diabetic (NOD) mice supplemented with 2 % TAU in their drinking water from birth until 90-days of age. TAU-supplemented female NOD mice (TAU group) showed a better glucose tolerance without modification in insulinemia, when compared to non-supplemented NOD mice (CTL). Glucose-induced insulin secretion was higher in islets isolated from female and male TAU groups. In addition, a better insulin release was observed at 30 mM K+ in islets from female TAU mice. These effects were accompanied by a higher total intracellular Ca2+ concentration in islets from female and male TAU mice. TAU-treated mice did not show any alteration in β-cell and islet areas, compared with CTL mice. Islets from TAU female mice presented a higher ratio of phosphorylated Akt and ERK (extracellular signal-regulated kinase) related to Akt and ERK protein content, respectively, in comparison with CTL islets. Additional experiments using isolated islets from Swiss mice showed that 3 mM TAU prevented the reduction in insulin secretion induced by 12 h incubation with IL1-β or IL1-β + IFN-γ. In conclusion, TAU supplementation improved NOD islet function without altering endocrine pancreatic morphometry, an effect that may be associated with a protective TAU effect upon cytokine-induced islet dysfunction, together with an improved protein expression of Akt and ERK.

Herbal Extracts Induce Dermal Papilla Cell Proliferation of Human Hair Follicles.

BackgroundThe number of people suffering from balding or hair thinning is increasing, despite the advances in various medical therapies. Therefore, it is highly important to develop new therapies to inhibit balding and increase hair proliferation.ObjectiveWe investigated the effects of herbal extracts commonly used for improving balding in traditional medicine to identify potential agents for hair proliferation.MethodsThe expression levels of 5α-reductase isoforms (type I and II) were analyzed using quantitative real-time reverse transcription polymerase chain reaction in the human follicular dermal papilla cells (DPCs). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylteterazolium bromide and bromodeoxyuridine tests were used to evaluate the cell proliferation effect of herbal extracts in DPCs. The expression levels of extracellular signal-regulated kinase (ERK), Akt, cyclin D1, cyclin-dependent kinase 4 (Cdk4), B-cell lymphoma (Bcl-2) and Bcl-2-associated X protein (Bax) were measured using western blot analysis.ResultsThe 5α-reductase isoform mRNAs and proteins were detected in the cultured DPCs, and the expression level of 5α-R2 in DPCs in the presence of the herbal extracts was gradually decreased. Herbal extracts were found to significantly increase the proliferation of human DPCs at concentrations ranging from 1.5% to 4.5%. These results show that the herbal extracts tested affected the protein expressions of ERK, Akt, cyclin D1, Cdk4, Bcl-2, and Bax in DPCs.ConclusionThese results suggest that herbal extracts exert positive effects on hair proliferation via ERK, Akt, cyclin D1, and Cdk4 signaling in DPCs; they also suggest that herbal extracts could be a great alternative therapy for increasing hair proliferation.

Effects of curcumin on learning and memory deficits, BDNF, and ERK protein expression in rats exposed to chronic unpredictable stress

Accumulating evidence suggests that cognitive processes, such as learning and memory, are affected in depression and antidepressant treatment may ameliorate cognitive impairments. Recent studies have shown that curcumin exhibits antidepressant-like effects. The aim of the present study was to determine whether curcumin administration influences chronic unpredictable stress (CUS)-induced cognitive deficits and explores underlying mechanisms. Male Wistar rats were subjected to CUS protocol for a period of 5 weeks to induce depression. The depressive-like behavior was tested using sucrose preference test, open field test and Morris water maze test. Effects of curcumin on brain-derived neurotrophic factor (BDNF) and extracellular signal-regulated kinase (ERK) levels in the hippocampus were also examined. Chronic treatment with curcumin significantly reversed the CUS-induced behavioral and cognitive parameters (reduced sucrose preference and impaired learning and memory function) in stressed rats. Additionally, CUS reduced hippocampal BDNF and ERK levels, while curcumin effectively reversed these alterations. Taken together, our results indicate that the antidepressant-like effects of curcumin in CUS rats are related to its aptitude to promote BDNF and ERK in the hippocampus.

Neuroprotective and anti-apoptotic effects of valproic acid on adult rat cerebral cortex through ERK and Akt signaling pathway at acute phase of traumatic brain injury

Mood stabilizer valproic acid (VPA), a widely used antiepileptic drug that has been demonstrated neuroprotective effect against various insults through multiple signaling pathways. The role of VPA in traumatic brain injury (TBI) remains unclear. In the present study, we investigated the neuroprotective potency of VPA for protection against TBI in adult rats, focusing on studying signaling mediators of two well characterized pro-survival molecules, extracellular signal-regulated protein kinase (ERK) and Akt. We found that treatment of VPA after TBI significantly attenuated brain edema, reduced contusion volume and the rate of neuronal apoptosis. The treatment also partly blocked an increase in capase-3 activity. VPA markedly up-regulated the activity of ERK and Akt expression. Moreover, treatment with either PD98059, an ERK inhibitor and/or LY294002, an Akt inhibitor, attenuated the neuroprotection of VPA against TBI to varying degrees. Taken together, these results demonstrated that treatment with VPA after TBI could be neuroprotective via activation of ERK and Akt signaling pathways