Expression Of P38 Mitogen-activated Protein Kinase Research Articles

Involvement of IGFBP5 in the Development of Goose Fatty Liver via p38 Mitogen-Activated Protein Kinase (MAPK)

Previous studies showed that insulin-like growth factor-binding protein 5 (IGFBP5) plays a role in non-alcoholic fatty liver disease; however, its expression and function in goose fatty liver remain unknown. To address this, we obtained a full-length mRNA sequence of the goose IGFBP5 gene using a 5′-rapid amplification of cDNA ends assay and nested polymerase chain reaction (PCR). Additionally, using the newly acquired sequence of 5’-untraslated region, we determined the missing sequence of the first intron. Bioinformatics analysis revealed three exons and three introns in the goose IGFBP5 gene. Quantitative PCR analysis indicated that the mRNA abundance of IGFBP5 was significantly lower in goose fatty liver than in the normal liver. Comparison of transcriptomes of goose primary hepatocytes transfected with IGFBP5 overexpression vector versus those transfected with empty vector identified 777 differentially expressed genes (DEGs). The enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways indicated the focal adhesion, ECM-receptor interaction, regulation of the actin cytoskeleton, mitogen-activated protein kinase (MAPK) signaling, and GnRH signaling pathways. Immunoblotting revealed the induction of the p38 MAPK pathway by IGFBP5 overexpression, which is in line with the suppressed expression of IGFBP5 and p38 MAPK in goose fatty liver than in normal liver. These findings suggest that IGFBP5 is involved in the development of goose fatty liver via the p38 MAPK pathway.

Protective role of activating PPARγ in advanced glycation end products-induced impairment of coronary artery vasodilation via inhibiting p38 phosphorylation and reactive oxygen species production

Advanced glycation end products (AGEs) can damage voltage-gated K+ (Kv) channels and attenuate coronary artery vasodilation, but the underlying mechanisms remain unclear. The aim of this study was to investigate the role and potential mechanism of PPARγ in AGEs-induced Kv 1 channels impairment. We used both primary rat coronary smooth muscle cells (CSMCs) in vitro and Zucker Diabetic Fatty (ZDF) rat model in vivo. Overexpression of the Pparg gene by lentivirus vector (LV-Pparg) was used to transfect CSMCs for upregulation PPARγ. Kv 1.2 and Kv 1.5 currents were measured by patch clamp. The vascular tone of coronary artery was evaluated by isometric force measurements. The proteins expression of Kv1.2 and Kv1.5 channel were detected by western blot. PPARγ was detected by immunofluorescence and western blot. Oxidative stress markers including superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) were detected by enzyme linked immunosorbent assay (ELISA). The phosphorylation of p38 mitogen-activated protein kinase (MAPK) and total p38 expression were detected by western blot. The intracellular ROS levels were measured by the fluorescent dye 2’,7’- dichlorofluorescein diacetate (DCFDA) and a cellular ROS assay kit. We found that activating PPARγ via LV-Pparg (100 MOI, 5 × 108 TU/mL) prevented AGEs (100 μg/mL) -mediated impairment of Kv 1.2 and Kv 1.5 channels activity and improved the reduction of Kv 1.2 and Kv 1.5 protein expression in CSMCs. Isometric force measurements showed that activating PPARγ by pioglitazone (10 mg/kg/d, intragastric administration) improved the impairment of coronary artery vasodilation, and western blot analysis showed that activating PPARγ increased the Kv 1.2 and Kv 1.5 protein expression, while inhibiting PPARγ by GW9662 (10 mg/kg/d, intraperitoneal injection) attenuated these effects in ZDF rats. Furthermore, LV-Pparg overexpression PPARγ attenuated NADPH oxidase activity, which was shown as the reduction of the NOX2 and p22phox expression by western blot analysis, decreased the MDA production and increased the SOD and GPx activities by ELISA, finally led to reduce AGEs-mediated ROS production. Moreover, activating PPARγ by LV-Pparg inhibited AGEs-induced phosphorylation of p38 MAPK, by which could reduce AGEs-mediated NOX2, p22phox expression and ROS production, while CSMCs treatment with SB203580 (10 μmol/L), a p38 MAPK inhibitor, attenuated these effects. Activating PPARγ plays a protective role in AGEs-induced impairment of coronary artery vasodilation by inhibiting p38 phosphorylation to attenuate NOX2 and p22phox expression and further decrease oxidative stress induced by ROS overproduction.

Er-Bai-Tang decoction improved the movement disorders and neuronal injury in the Parkinson's disease model rats via decreasing p38 MAPK pathway and improving the composition of intestinal flora.

Our previous study showed that Er-Bai-Tang decoction (EBT) could effectively improve Parkinson's disease (PD) patients' quality of life, sleep, mood, and cognitive disorders, but the mechanism of EBT to treat PD was unclear. So, our study aimed to explore the mechanism of EBT to treat PD via p38 mitogen-activated protein kinases (MAPK) pathway and intestinal flora. In our study, the PD rat model was established by subcutaneously injecting 2 mg/kg/d rotenone solution, and 23.43 g/kgEBT was used to treat PD model rats. Behavioral test showed that EBT could reverse the motor impairment in the PD model rats. Hematoxylin and eosin result showed that EBT could reduce the cell necrosis in the SNpc area of the PD model rats. Western blotting and real time-polymerase chain reaction showed that EBT could decrease the p38 MAPK expression in the SNpc area of the PD model rats. 16s rRNA sequencing analysis showed that EBT could improve the composition of intestinal flora in the PD model rats. Rikenellaceae at family level and Alistipes and Allobaculum at the genus level were the key species in the PD development and EBT treatment to PD. KEGG showed that EBT might change the iron uptake in PD rats. EBT could improve the motor symptoms and neuronal injury in the PD model rat, and its mechanism may be related to decreasing p38 MAPK pathway and improving the composition of intestinal flora.

Picropodophyllotoxin Induces G1 Cell Cycle Arrest and Apoptosis in Human Colorectal Cancer Cells via ROS Generation and Activation of p38 MAPK Signaling Pathway.

Picropodophyllotoxin (PPT), an epimer of podophyllotoxin, is derived from the roots of Podophyllum hexandrum and exerts various biological effects, including anti-proliferation activity. However, the effect of PPT on colorectal cancer cells and the associated cellular mechanisms have not been studied. In the present study, we explored the anticancer activity of PPT and its underlying mechanisms in HCT116 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to monitor cell viability. Flow cytometry was used to evaluate cell cycle distribution, the induction of apoptosis, the level of reactive oxygen species (ROS), assess the mitochondrial membrane potential (Δψm), and multi-caspase activity. Western blot assays were performed to detect the expression of cell cycle regulatory proteins, apoptosis-related proteins, and p38 MAPK (mitogen-activated protein kinase). We found that PPT induced apoptosis, cell cycle arrest at the G1 phase, and ROS in the HCT116 cell line. In addition, PPT enhanced the phosphorylation of p38 MAPK, which regulates apoptosis and PPT-induced apoptosis. The phosphorylation of p38 MAPK was inhibited by an antioxidant agent (N-acetyl-L-cysteine, NAC) and a p38 inhibitor (SB203580). PPT induced depolarization of the mitochondrial inner membrane and caspase-dependent apoptosis, which was attenuated by exposure to Z-VAD-FMK. Overall, these data indicate that PPT induced G1 arrest and apoptosis via ROS generation and activation of the p38 MAPK signaling pathway.

Discoidin domain receptor 2 activation of p38 mitogen-activated protein kinase as an important pathway for osteonectin-regulating osteoblast mineralization

ObjectiveThe present study aimed to determine the role of the discoidin domain receptor 2 (DDR2) in the osteonectin (ON) regulation of osteoblast mineralization through the activation of p38 mitogen-activated protein kinase (MAPK).MethodsFour groups were established: the ON group, the inhibitor group, the Ddr2-small interfering ribonucleic acid (siRNA) group, and the control group. Osteoblasts from the parietal bones of neonatal Sprague–Dawley rats were isolated and cultured. In the ON group, 1 µg/mL ON was added to the osteoblasts. The gene expressions of collagen 1 (Col 1) and Ddr2 were detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In the inhibitor group, the osteoblasts were added to WRG-28 (a specific DDR2 inhibitor), and in the Ddr2-siRNA group, the osteoblasts were transfected with Ddr2-siRNA. The gene and protein expressions of DDR2, bone sialoprotein, osteocalcin, osteopontin, and p38 MAPK were determined using RT-qPCR and western blot analysis. Alizarin red staining and transmission electron microscopy were used to detect mineralization.ResultsThe results showed that ON enhanced the osteoblast Col 1 and Ddr2 gene expressions, while the use of a Ddr2-siRNA/DDR2-blocker decreased the OPN, BSP, OCN, and P38 gene and protein expressions and reduced osteoblast cellular activity and mineralized nodules.ConclusionThe present study demonstrated that DDR2 activation of p38 MAPK is an important approach to ON-regulating osteoblast mineralization.

Lobeglitazone, A Peroxisome Proliferator-Activated Receptor-Gamma Agonist, Inhibits Papillary Thyroid Cancer Cell Migration and Invasion by Suppressing p38 MAPK Signaling Pathway.

BackgroundPeroxisome proliferator-activated receptor-gamma (PPAR-γ) ligands have been widely shown to correlate with epithelial-mesenchymal transition (EMT) and cancer progression. Lobeglitazone (LGZ) is a novel ligand of PPAR-γ; and its role in EMT and metastasis in papillary thyroid carcinoma (PTC) is poorly understood. We aimed to investigate the role of LGZ in metastatic behavior of PTC cells.MethodsHalf maximal inhibitory concentration (IC50) values of LGZ in BRAF-mutated PTC cell lines (BCPAP and K1) were determined using MTT assay. Rosiglitazone (RGZ), the PPAR-γ ligand was used as a positive control. The protein expression of PPAR-γ, cell-surface proteins (E-cadherin, N-cadherin), cytoskeletal protein (Vimentin), transcription factor (Snail), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) 1/2 pathway, and matrix metalloproteinase (MMP)-2 expression were measured using Western blotting. Changes in E-cadherin expression were also determined using immunocytochemistry. Cell migration and invasion were analyzed using wound healing and Matrigel invasion assays.ResultsTreatment with LGZ or RGZ significantly inhibited transforming growth factor-beta1 (TGF-β1)-induced EMT-associated processes such as fibroblast-like morphological changes, EMT-related protein expression, and increased cell migration and invasion in BCPAP and K1 cells. LGZ restored TGF-β1-induced loss of E-cadherin, as observed using immunocytochemistry. Furthermore, LGZ and RGZ suppressed TGF-β1-induced MMP-2 expression and phosphorylation of p38 MAPK, but not ERK1/2. Although there was no change in PPAR-γ expression after treatment with LGZ or RGZ, the effect of downstream processes mediated by LGZ was hampered by GW9662, a PPAR-γ antagonist.ConclusionLGZ inhibits TGF-β1-induced EMT, migration, and invasion through the p38 MAPK signaling pathway in a PPAR-γ-dependent manner in PTC cells.

Acanthus ilicifolius L. Treatment for Oral Candidiasis with Immunosuppressive Conditions Subjected to p38 MAPK Enhancement

Methanolic extract from the leaves of Acanthus ilicifolius L. (A. ilicifolius L.) is a potent inhibitor of Candida albicans (C. albicans) growth and anti-inflammatory. C. albicans causes oral candidiasis in immunosuppressive condition. Mitogen-activated protein kinase (MAPK) signalling via p38 appears to discriminate between yeast and hyphal cells of C. albicans. Activation of p38 MAPK by hyphae results in the upregulation of proinflammatory cytokines. The p38 MAPK activation is known to impair corticosteroid action. The research was conducted to investigate the effect of methanolic extract A. ilicifolius L. treatment of oral candidiasis with the immunosuppressive condition through enhancement of p38 MAPK expression in the epithelial cells. Immunosuppressed conditions were obtained when 16 healthy male Rattus norvergicus (Wistar) was given oral administration of dexamethasone and tetracycline for 14 days and induced with C. albicans (ATCC-10231) 1 McFarland. The subjects were divided into four groups (n = 4/group): immunosuppression (IS), immunosuppression with oral candidiasis without treatment (ISC), immunosuppression with oral candidiasis and nystatin treatment (ISC+N), and immunosuppression with oral candidiasis and A. ilicifolius L. treatment (ISC+AI), and were treated for 14 days. Later, the rats were euthanised, and their tongue were biopsied. The p38 MAPK expression was subjected to immunohistochemical examination, observed under a microscope (400× magnification) and statistically analysed (one-way ANOVA, LSD-test, p < 0.05). The p38 MAPK expression of ISC+AI (36.05 ± 1.54) was higher than IS (26 ± 2.32), ISC (26.4 ± 3.71), IS+N (34.2 ± 0.99). Significant differences existed between ISC+AI and ISC+N to IS and ISC (p < 0.05). No significant differences were present between IS and ISC; ISC+AI and ISC+N (p > 0.05). Therefore, this treatment could enhance p38 MAPK expression in oral candidiasis with the immunosuppressed condition.

A Retinoic Acid Receptor β 2 Agonist Improves Cardiac Function in a Heart Failure Model.

We previously demonstrated that the selective retinoic acid receptor (RAR) β 2 agonist AC261066 reduces oxidative stress in an ex vivo murine model of ischemia/reperfusion. We hypothesized that by decreasing oxidative stress and consequent fibrogenesis, AC261066 could attenuate the development of contractile dysfunction in post-ischemic heart failure (HF). We tested this hypothesis in vivo using an established murine model of myocardial infarction (MI), obtained by permanent occlusion of the left anterior descending coronary artery. Treating mice with AC261066 in drinking water significantly attenuated the post-MI deterioration of echocardiographic indices of cardiac function, diminished remodeling, and reduced oxidative stress, as evidenced by a decrease in malondialdehyde level and p38 mitogen-activated protein kinase expression in cardiomyocytes. The effects of AC261066 were also associated with a decrease in interstitial fibrosis, as shown by a marked reduction in collagen deposition and α-smooth muscle actin expression. In cardiac murine fibroblasts subjected to hypoxia, AC261066 reversed hypoxia-induced decreases in superoxide dismutase 2 and angiopoietin-like 4 transcriptional levels as well as the increase in NADPH oxidase 2 mRNA, demonstrating that the post-MI cardioprotective effects of AC261066 are associated with an action at the fibroblast level. Thus, AC261066 alleviates post-MI cardiac dysfunction by modulating a set of genes involved in the oxidant/antioxidant balance. These AC261066 responsive genes diminish interstitial fibrogenesis and remodeling. Since MI is a recognized major cause of HF, our data identify RARβ 2 as a potential pharmacological target in the treatment of HF. SIGNIFICANCE STATEMENT: A previous report showed that the selective retinoic acid receptor (RAR) β 2 agonist AC261066 reduces oxidative stress in an ex vivo murine model of ischemia/reperfusion. This study shows that AC261066 attenuates the development of contractile dysfunction and maladaptive remodeling in post-ischemic heart failure (HF) by modulating a set of genes involved in oxidant/antioxidant balance. Since myocardial infarction is a recognized major cause of HF, these data identify RARβ 2 as a potential pharmacological target in the treatment of HF.

Electroacupuncture alleviates the transition from acute to chronic pain through the p38 MAPK/TNF-α signalling pathway in the spinal dorsal horn.

Hyperalgesic priming (HP) is a model of the transition from acute to chronic pain. Electroacupuncture (EA) could inhibit pain development through the peripheral dorsal root ganglia; however, it is unclear whether it can mitigate the transition from acute to chronic pain by attenuating protein expression in the p38 MAPK (mitogen-activated protein kinase)/tumour necrosis factor alpha (TNF-α) pathway in the spinal dorsal horn. We aimed to determine whether EA could prevent the transition from acute to chronic pain by affecting the p38 MAPK/TNF-α pathway in the spinal dorsal horn in a rat model established using HP. We first randomly subdivided 30 male Sprague-Dawley (SD) rats into 5 groups (n = 6 per group): control (N), sham HP (Sham-HP), HP, HP + SB203580p38 MAPK (HP+SB203580), and HP + Lenalidomide (CC-5013) (HP+Lenalidomide). We then randomly subdivided a further 30 male SD rats into 5 groups (n = 6 per group): Sham-HP, HP, sham EA (Sham EA), EA (EA), and EA + U-46619 p38 MAPK agonist (EA+U-46619). We assessed the effects of EA on the mechanical paw withdrawal threshold and p38 MAPK/TNF-α expression in the spinal dorsal horn of rats subjected to chronic inflammatory pain. Rats in the EA group had reduced p38 MAPK and TNF-α expression and had significantly reduced mechanical hyperalgesia compared with rats in the other groups. Our findings indicate that EA could increase the mechanical pain threshold in rats and inhibit the transition from acute pain to chronic pain. This mechanism could involve reduced p38 MAPK/TNF-α expression in the spinal dorsal horn.

Modulation of proinflammatory mediators by viruses-bacteria synergism in human osteoblasts-an in vitro study

Viruses-bacteria synergistic interaction is associated with destructive periodontal diseases. However, the underlying mechanism for tissue destruction is not fully elucidated. In this study, lipopolysaccharide from Porphyromonas gingivalis (Pg-LPS) and polyinosinic-polycytidylic acid (poly I:C) were used to simulate bacteria and viruses, respectively. The possible combined effects of both molecular patterns on secretion of interleukin (IL)-6 and prostaglandin E2 (PGE2) from osteoblasts were determined. The effects of povidone-iodine (PVP-I) on the secretion of IL-6 and PGE2 were also examined. Viability of treated osteoblastic cells (MG63) was examined by detection the mitochondrial dehydrogenase activity. Secretion of IL-6 and PGE2 was detected using the enzyme-linked immunosorbent assay (ELISA). Mitogen-activated protein kinases (MAPKs) and cyclooxygenase-2 (COX-2) were determined using the Western blotting analysis. Pg-LPS or poly I:C significantly enhanced the production of IL-6 and PGE2 in MG63cells. The additive/synergistic effects of Pg-LPS/poly I:C on production of IL-6 and PGE2 were evident. The levels of phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) and expression of COX-2 protein were enhanced by Pg-LPS and/or poly I:C. On the other hand, the level of phosphorylation of extracellular signal-regulated kinase (ERK) was reduced by Pg-LPS and/or poly I:C. The stimulatory secretion of PGE2 by poly I:C was significantly reduced by PVP-I. Concomitant infection of viruses and bacteria may be potentially harmful to the tooth supporting tissues by production of proinflammatory mediators. The results suggest the potential anti-inflammatory effect of PVP-I on bacterial or viral infection.

The Expression of TGF-b1, p38 MAPK, and ERK-1 Protein in Cleft Affected Tissue of the Lip: An Observational Study

Background: Cleft lip is a congenital birth defect caused by many proteins. Transforming growth factor (TGF)-β1, p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated protein kinase (ERK)-1 are proteins which regulate proliferation and apoptosis role during intrauterine period. This study aimed to observe the expression of these proteins in cleft affected tissue of the lip.Materials and Methods: A descriptive study by examining the TGF-β1, p38 MAPK, and ERK-1 immunohistochemical expression of cleft affected tissue of the lip was conducted. Subjects were patients that were participating for the social event held by Plastic Surgery Department, Faculty of Medicine, Univesitas Brawijaya, on December 3-12, 2012 in Nusa Tenggara Timur. Excess lip mucosa (waste tissue) during the operation were stored in 10% formalin then stained by immunohistochemistry for TGF-β1, p38 MAPK, and ERK-1. We counted the average protein expression under the light microscope with 1000x magnification for 20 different fields of view, randomly.Results: Paraffin blocks from 30 subjects were selected. The mean p38 MAPK expression was found to be highest, with the average of 8 per field of view; followed by the mean TGF-β1 expression, with the average of 5 per field of view; and the mean ERK-1 expression was found to be the lowest, with the average of 2 per field of view. Conclusion: Expression of p38 MAPK and TGF-β1 are higher than ERK-1, suggesting that p38 MAPK is in the same signalling pathway as TGF-β1, while ERK-1 is lower, as its role as anti-apoptotic. This is consistent with several previous studies showing that all proteins took part in the development of cleft lip or craniofacial development. Further study needs to be conducted to determine which protein plays the bigger role.Keywords: cleft lip, TGF-β1, p38 MAPK, ERK-1

Protective effect of (+)-catechin against lipopolysaccharide-induced inflammatory response in RAW 264.7 cells through downregulation of NF-κB and p38 MAPK.

Catechin, a flavonol belonging to the flavonoid group of polyphenols is present in many plant foods. The present study was done to evaluate the effect of catechin on various inflammatory mediators using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The effect of catechin on total cyclooxygenase (COX) activity, 5-lipoxygenase (5-LOX), myeloperoxidase, nitrite and inducible nitric oxide synthase (iNOS) level, secretion of tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were assessed in LPS-stimulated RAW 264.7 cells. The expression of COX-2, iNOS, TNF-α, nuclear factor-ĸB (NF-κB) and p38 mitogen-activated protein kinase (MAPK) genes were also investigated. The effect was further analyzed using human PBMCs by assessing the level of TNF-α and IL-10. The study demonstrated that the inflammatory mediators such as COX, 5-LOX, nitrite, iNOS, and TNF-α were significantly inhibited by catechin in a concentration-dependent manner whereas IL-10 production was up-regulated in RAW 264.7 cells. Moreover, catechin down-regulated the mRNA level expression of COX-2, iNOS, TNF-α, NF-κB and p38 MAPK. The current study ratifies the beneficial effect of catechin as a dietary component in plant foods to provide protection against inflammatory diseases.

Management of Acute Lung Injury: Palmitoylethanolamide as a New Approach.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common and devastating clinical disorders with high mortality and no specific therapy. Lipopolysaccharide (LPS) is usually used intratracheally to induce ALI in mice. The aim of this study was to examine the effects of an ultramicronized preparation of palmitoylethanolamide (um-PEA) in mice subjected to LPS-induced ALI. Histopathological analysis reveals that um-PEA reduced alteration in lung after LPS intratracheal administration. Besides, um-PEA decreased wet/dry weight ratio and myeloperoxidase, a marker of neutrophils infiltration, macrophages and total immune cells number and mast cells degranulation in lung. Moreover, um-PEA could also decrease cytokines release of interleukin (IL)-6, interleukin (IL)-1β, tumor necrosis factor (TNF)-α and interleukin (IL)-18. Furthermore, um-PEA significantly inhibited the phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation in ALI, and at the same time decreased extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38/MAPK) expression, that was increased after LPS administration. Our study suggested that um-PEA contrasted LPS-induced ALI, exerting its potential role as an adjuvant anti-inflammatory therapeutic for treating lung injury, maybe also by p38/NF-κB pathway.

Protective effects of baicalin in a Caenorhabditis elegans model of Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disorder of the central nervous system. However, the pathogenetic mechanisms of PD are far from understood. The aim of this study was to determine the protective effect of baicalin in a Caenorhabditis elegans model of PD. C. elegans worms were stimulated for 24h with 6-hydroxydopamine (6-OHDA, 50mM) and treated with or without baicalin (1, 10, or 100μM). At all tested concentrations, baicalin improved the reversal and omega turn behavioral phenotypes, as well as the survival, of 6-OHDA-stimulated worms. It also inhibited 6-OHDA-induced oxidative stress by decreasing malondialdehyde levels, increasing superoxide dismutase, glutathione reductase, catalase, and glutathione levels and up-regulating mRNA expression of the antioxidant-related genes sod-1, sod-2, sod-3, daf-2, and daf-16. Additionally, it significantly decreased the expression of the apoptosis-related gene ced-3 and increased that of the anti-apoptosis-related gene ced-9. The expression levels of cleaved caspase-3 and B-cell lymphoma 2 in 6-OHDA-treated worms were reversed by baicalin. Apoptosis was suppressed by 6-OHDA in loss-of-function strains via the p38 mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, the apoptotic effects of 6-OHDA were blocked in sek-1 and pmk-1 mutants. Finally, the mRNA expression of sek-1 and pmk-1 and the protein expression of p38 MAPK and stress-activated protein kinase/extracellular signal-regulated kinase 1 were up-regulated by 6-OHDA and reversed by baicalin. Baicalin may protect against 6-OHDA injury by inhibiting apoptosis and decreasing oxidative stress through the p38 MAPK signaling pathway.

Propofol alleviates intestinal ischemia/reperfusion injury in rats through p38 MAPK/NF-κB signaling pathway.

The aim of this study was to investigate the influences of propofol on intestinal ischemia/reperfusion (I/R) injury in rats through the p38 mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB) signaling pathway. The models of intestinal I/R injury were first successfully established. All rats were randomly divided into 4 groups, namely, S group, I/R group, P group and P + S group. Pathological-morphological changes, injury score and wet-to-dry weight ratio of intestinal tissues as well as oxidative stress indexes in each group of rats were detected. Enzyme-linked immunosorbent assay (ELISA) was applied to measure the levels of inflammatory factors such as creatine kinase-MB (CK-MB), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in each group of rats. Furthermore, Western blotting (WB) assay was applied to determine the protein expression levels of p38 MAPK and NF-κB in different groups. Intestinal tissue injury was the severest in I/R group, with the infiltration of massive inflammatory cells and oozing of blood (Figure 1A, I/R). Compared with those in I/R group, the infiltration of inflammatory cells and damage to intestinal villi were notably relieved in P group and P + S group, revealing that the intestinal mucosal injury was remarkably repaired in P group and P + S group (Figure 1A, P). Moreover, the intestinal tissue injury score was evidently higher in I/R group, P group and P + S group than that in S group (p<0.05). However, it was markedly lower in P group and P + S group than that in I/R group (p<0.05). I/R group, P group and P + S group exhibited significantly increased wet-to-dry weight ratio of intestinal tissues in comparison with S group (p<0.05). However, P group and P + S group exhibited distinctly lower wet-to-dry weight ratio of intestinal tissues than I/R group (p<0.05). The content of malondialdehyde (MDA) was reduced prominently, while that of superoxide dismutase (SOD) was elevated significantly in P group and P + S group in contrast with those in I/R group (p<0.05). On the contrary, P + S group displayed remarkably lower MDA content and higher SOD content than P group (p<0.05). The levels of CK-MB, TNF-α and IL-6 in the blood rose markedly in I/R group compared with those in S group (p<0.05). However, they declined evidently in P group and P + S group in contrast with those in I/R group (p<0.05). Besides, the protein expression level of phosphorylated p38 MAPK was significantly higher in I/R group, P group and P + S group than that in S group (p<0.05). However, no significant difference was observed in the protein expression of total p38 MAPK among the four groups (p>0.05). However, the protein expression level of phosphorylated p38 MAPK was distinctly down-regulated in P group and P + S group in comparison with that in I/R group (p<0.05). Finally, I/R group, P group and P + S group had a prominently higher protein expression level of NF-κB than S group (p<0.05). However, P group and P + S group exerted a significantly lower protein expression level of NF-κB than I/R group (p<0.05). Propofol decreases the release of inflammatory factors and alleviates intestinal edema by inhibiting the p38 MAPK/NF-κB signaling pathway, thereby mitigating and treating the intestinal I/R injury in rats.

Hydroxychavicol, a polyphenol from Piper betle leaf extract, induces cell cycle arrest and apoptosis in TP53-resistant HT-29 colon cancer cells.

This study aims to elucidate the antiproliferative mechanism of hydroxychavicol (HC). Its effects on cell cycle, apoptosis, and the expression of c-Jun N-terminal kinase (JNK) and P38 mitogen-activated protein kinase (MAPK) in HT-29 colon cancer cells were investigated. HC was isolated from Piper betle leaf (PBL) and verified by high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and gas chromatography-mass spectrometry (GC-MS). The cytotoxic effects of the standard drug 5-fluorouracil (5-FU), PBL water extract, and HC on HT-29 cells were measured after 24, 48, and 72 h of treatment. Cell cycle and apoptosis modulation by 5-FU and HC treatments were investigated up to 30 h. Changes in phosphorylated JNK (pJNK) and P38 (pP38) MAPK expression were observed up to 18 h. The half maximal inhibitory concentration (IC50) values of HC (30 μg/mL) and PBL water extract (380 μg/mL) were achieved at 24 h, whereas the IC50 of 5-FU (50 μmol/L) was obtained at 72 h. Cell cycle arrest at the G0/G1 phase in HC-treated cells was observed from 12 h onwards. Higher apoptotic cell death in HC-treated cells compared to 5-FU-treated cells (P<0.05) was observed. High expression of pJNK and pP38 MAPK was observed at 12 h in HC-treated cells, but not in 5-FU-treated HT-29 cells (P<0.05). It is concluded that HC induces cell cycle arrest and apoptosis of HT-29 cells, with these actions possibly mediated by JNK and P38 MAPK.

Development and Validation of Nomograms Based on Gamma-Glutamyl Transpeptidase to Platelet Ratio for Hepatocellular Carcinoma Patients Reveal Novel Prognostic Value and the Ratio Is Negatively Correlated With P38MAPK Expression.

BackgroundEarly prediction of recurrence and death risks is significant to the treatment of hepatocellular carcinoma (HCC) patients. We aimed to develop and validate prognosis nomogram models based on the gamma-glutamyl transpeptidase (GGT)-to-platelet (PLT) ratio (GPR) for HCC and to explore the relationship between the GPR and inflammation-related signaling pathways.MethodsAll data were obtained from 2000 to 2012 in the Affiliated Hospital of Qingdao University. In the training cohort, factors included in the nomograms were determined by univariate and multivariate analyses. In the training and validation cohorts, the concordance index (C-index) and calibration curves were used to assess predictive accuracy, and receiver operating characteristic curves were used to assess discriminative ability. Clinical utility was evaluated using decision curve analysis. Moreover, improvement of the predictive accuracy of the nomograms was evaluated by calculating the decision curve analysis, the integrated discrimination improvement, and the net reclassification improvement. Finally, the relationship between the GPR and inflammation-related signaling pathways was evaluated using the independent-samples t-test.ResultsA larger tumor size and higher GPR were common independent risk factors for both disease-free survival (DFS) and overall survival (OS) in HCC (P < 0.05). Good agreement between our nomogram models’ predictions and actual observations was detected by the C-index and calibration curves. Our nomogram models showed significantly better performance in predicting the HCC prognosis compared to other models (P < 0.05). Online webserver and scoring system tables were built based on the proposed nomogram for convenient clinical use. Notably, including the GPR greatly improved the predictive ability of our nomogram models (P < 0.05). In the validation cohort, p38 mitogen-activated protein kinase (P38MAPK) expression was significantly negatively correlated with the GPR (P < 0.01) and GGT (P = 0.039), but was not correlated with PLT levels (P = 0.063). And we found that P38MAPK can regulate the expression of GGT by quantitative real-time PCR and Western blotting experiments.ConclusionsThe dynamic nomogram based on the GPR provides accurate and effective prognostic predictions for HCC, and P38MAPK-GGT may be a suitable therapeutic target to improve the prognosis of HCC patients.

Low-dose cannabinoid receptor 2 agonist induces microglial activation in a cancer pain-morphine tolerance rat model

AimsCancer pain seriously affects the life quality of patients. Morphine is commonly used for cancer pain, but tolerance development limits its clinical administration. Central immune signaling is important in the development of cancer pain and morphine tolerance. Cannabinoid receptor 2 (CB2) inhibits cancer pain and morphine tolerance by regulating central immune signaling. In the present study, we investigated the mechanisms of central immune signaling involved in morphine tolerance inhibition by the CB2 agonist AM1241 in cancer pain treatment. Main methodsRats were implanted with tumor cells and divided into 4 groups: Vehicle (PBS), 0.07 μg AM1241, 0.03 μg AM1241, and AM630 (10 μg) + AM1241 (0.07 μg). All groups received morphine (20 μg/day, i.t.) for 8 days. AM630 (CB2 antagonist) was intrathecally injected 30 min before AM1241, and AM1241 was intrathecally injected 30 min before morphine. The spinal cord (SC) and dorsal root ganglion (DRG) were collected to determine the expression of Toll-like receptor 4 (TLR4), the p38 mitogen-activated protein kinase (MAPK), microglial markers, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α. Key findingsThe expression of TLR4, p38 MAPK, microglial markers, IL-1β, and TNF-α was significantly higher in AM1241-pretreated groups than in the vehicle group (P < 0.05). No difference in microglial markers, IL-1β, and TNF-α expression was detected in the AM630 + AM1241 group compared with the vehicle group. SignificanceOur results suggest that in a cancer pain-morphine tolerance model, an i.t. non-analgesic dose of AM1241 induces microglial activation and IL-1β TNF-α upregulation in SC and DRG via the CB2 receptor pathway.

Microparticles derived from human erythropoietin mRNA-transfected mesenchymal stem cells inhibit epithelial-to-mesenchymal transition and ameliorate renal interstitial fibrosis

BackgroundRenal tubulointerstitial fibrosis (TIF) plays an important role in the progression of chronic kidney disease (CKD) and its pathogenesis involves epithelial-to-mesenchymal transition (EMT) upon renal injury. Recombinant human erythropoietin (rhEPO) has been shown to display novel cytoprotective effects, in part by inhibiting transforming growth factor (TGF)-β1-induced EMT. Here, we evaluated the inhibitory effects of microparticles (MPs) derived from human EPO gene-transfected kidney mesenchymal stem cells (hEPO-KMSCs) against TGF-β1-induced EMT in Madin-Darby canine kidney (MDCK) cells and against TIF in mouse kidneys with unilateral ureteral obstruction (UUO).MethodsEMT was induced in MDCK cells by treatment with TGF-β1 (5 ng/mL) for 48 h and then inhibited by co-treatment with rhEPO (100 IU/mL), mock gene-transfected KMSC-derived MPs (MOCK-MPs), or hEPO-KMSC-derived MPs (hEPO-MPs) for a further 48 h. UUO was induced in FVB/N mice, which were then treated with rhEPO (1000 IU/kg, intraperitoneally, every other day for 1 week), MOCK-MPs, or hEPO-MPs (80 μg, intravenously). Alpha-smooth muscle actin (α-SMA), fibronectin, and E-cadherin expression were evaluated in MDCK cells and kidney tissues, and the extent of TIF in UUO kidneys was assessed by immunohistochemical staining.ResultsTGF-β1 treatment significantly increased α-SMA and fibronectin expression in MDCK cells and decreased that of E-cadherin, while co-treatment with rhEPO, MOCK-MPs, or hEPO-MPs markedly attenuated these changes. In addition, rhEPO and hEPO-MP treatment effectively decreased phosphorylated Smad2 and Smad3, as well as phosphorylated p38 mitogen-activated protein kinase (MAPK) expression, suggesting that rhEPO and rhEPO-MPs can inhibit TGF-β1-induced EMT via both Smad and non-Smad pathways. rhEPO and hEPO-MP treatment also significantly attenuated the extent of renal TIF after 1 week of UUO compared to MOCK-MPs, with hEPO-MPs significantly reducing myofibroblast and F4/80+ macrophage infiltration as well as EMT marker expression in UUO renal tissues in a similar manner to rhEPO.ConclusionsOur results demonstrate that hEPO-MPs modulate TGF-β1-induced EMT in MDCK cells via the Smad2, Smad3, and p38 MAPK pathways and significantly attenuated renal TIF in UUO kidneys.

P38 Mitogen-activated protein kinase regulates chamber-specific perinatal growth in heart.

In the mammalian heart, the left ventricle (LV) rapidly becomes more dominant in size and function over the right ventricle (RV) after birth. The molecular regulators responsible for this chamber-specific differential growth are largely unknown. We found that cardiomyocytes in the neonatal mouse RV had lower proliferation, more apoptosis, and a smaller average size compared with the LV. This chamber-specific growth pattern was associated with a selective activation of p38 mitogen-activated protein kinase (MAPK) activity in the RV and simultaneous inactivation in the LV. Cardiomyocyte-specific deletion of both the Mapk14 and Mapk11 genes in mice resulted in loss of p38 MAPK expression and activity in the neonatal heart. Inactivation of p38 activity led to a marked increase in cardiomyocyte proliferation and hypertrophy but diminished cardiomyocyte apoptosis, specifically in the RV. Consequently, the p38-inactivated hearts showed RV-specific enlargement postnatally, progressing to pulmonary hypertension and right heart failure at the adult stage. Chamber-specific p38 activity was associated with differential expression of dual-specific phosphatases (DUSPs) in neonatal hearts, including DUSP26. Unbiased transcriptome analysis revealed that IRE1α/XBP1-mediated gene regulation contributed to p38 MAPK-dependent regulation of neonatal cardiomyocyte proliferation and binucleation. These findings establish an obligatory role of DUSP/p38/IRE1α signaling in cardiomyocytes for chamber-specific growth in the postnatal heart.