P38 Mitogen-activated Protein Kinase Levels Research Articles

Myogenin Regulates DUSP13 to Inhibit Apoptosis Induced by Reactive Oxygen Species.

Myogenin is well known as a crucial transcription factor in skeletal muscle development, yet its other biological functions remain unexplored. Previous research showed that myogenin suppresses apoptosis induced by angiotensin II in human induced pluripotent stem cell-derived cardiomyocytes, and offered a new perspective on myogenin's role in cardioprotection. However, the detailed mechanism of this cardioprotection, especially under oxidative stress, is still unclear. In this study, hydrogen peroxide (H2O2) was used to generate reactive oxygen species in myogenin-overexpressing cardiomyocytes. The apoptosis was examined by flow cytometry. Transcriptome sequencing (RNA-seq) was performed to identify genes regulated by myogenin. Western blotting was used to detect the protein level of DUSP13 and the phosphorylation level of p38 mitogen-activated protein kinase (MAPK). The dual-luciferase reporter assay and ChIP assay were used to confirm the binding of myogenin to the promoter region of DUSP13. DUSP13 overexpression and knockdown assays were performed to study its anti-apoptotic role. Flow cytometry analysis of apoptosis showed that overexpressing myogenin for 24 and 48 hours decreased the apoptotic ratio by 47.9% and 63.5%, respectively, compared with untreated controls. Transcriptome sequencing performed on cardiomyocytes that expressed myogenin for different amounts of time (6, 12, 24, and 48 hours) identified DUSP13 as being up-regulated by myogenin. Western blotting showed that overexpression of myogenin increased the expression of DUSP13 and decreased the phosphorylation level of p38 MAPK. A dual-luciferase reporter assay proved that myogenin bound directly to the promoter region of DUSP13 and led to strong relative luciferase activity. Direct expression of DUSP13A and DUSP13B significantly reduced the rates of apoptosis and necrosis in cells treated with H2O2. Knockdown of DUSP13B significantly increased the rate of apoptosis in cells treated with H2O2. The present findings suggest that myogenin might attenuate apoptosis induced by reactive oxygen species by up-regulating DUSP13 and inactivating the p38 MAPK pathway.

Mesenchymal stem cells with p38 mitogen-activated protein kinase interference ameliorate mouse ischemic stroke.

Mesenchymal stem cells (MSCs) have been widely used in the treatment of ischemic stroke. However, factors such as high glucose, oxidative stress, and aging can lead to the reduced function of donor MSCs. The p38 mitogen-activated protein kinase (MAPK) signaling pathway is associated with various functions, such as cell proliferation, apoptosis, senescence, differentiation, and paracrine secretion. This study examined the hypothesis that the downregulation of p38 MAPK expression in MSCs improves the prognosis of mice with ischemic stroke. Lentiviral vector-mediated short hairpin RNA (shRNA) was constructed to downregulate the expression level of p38 MAPK in mouse bone marrow-derived MSCs. The growth cycle, apoptosis, and senescence of MSCs after infection were examined. A mouse model of ischemic stroke was constructed. After MSC transplantation, the recovery of neurological function in the mice was evaluated. Lentivirus-mediated shRNA significantly downregulated the mRNA and protein expression levels of p38 MAPK. The senescence of MSCs in the p38 MAPK downregulation group was significantly reduced, but the growth cycle and apoptosis did not significantly change. Compared with the control group, the infarct volume was reduced, and the neurological function and the axonal remodeling were improved in mice with ischemic stroke after transplantation of MSCs with downregulated p38 MAPK. Immunohistochemistry confirmed that in the p38 MAPK downregulation group, apoptotic cells were reduced, and the number of neuronal precursors and the formation of white matter myelin were increased. In conclusion, downregulation of p38 MAPK expression in MSCs improves the therapeutic effect in mice with ischemic stroke, an effect that may be related to a reduction in MSC senescence. This method is expected to improve the efficacy of MSCs in patients, especially in patients with underlying diseases such as diabetes, thus providing a basis for clinical individualized treatment for cerebral infarction.

Exploring the Potential of Thymoquinone-Stabilized Selenium Nanoparticles: In HEC1B Endometrial Cancer Cells Revealing Enhanced Anticancer Efficacy.

The aim of this research is to examine the potential anticancer properties of thymoquinone (TQ)-encapsulated selenium nanoparticles (TQ-SeNPs) in HEC1B endometrial carcinoma cells. TQ-SeNPs were synthesized, and their size, morphology, and elemental analysis were characterized. Morphological changes were examined by using scanning electron microscopy (SEM). The cytotoxicity and viability of nanothymoquinone were assessed by the XTT (2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5 carboxanilide) assay. Gene expressions and protein levels of the mitogen-activated protein kinase (MAPK) signaling pathway were analyzed by real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The decrease in the viability of HEC1B endometrial carcinoma cells was observed in a time- and dose-dependent manner. HEC-1B cells were treated with TQ-SeNP at 40-640 μg/mL concentrations and time intervals, and their viability was assessed by XTT assay. IC50 doses of TQ-SeNP in HEC1B cells were detected as 526.45 μg/mL at 48th hour. ELISA indicated that TQ-SeNP treatment reduced the level of p38 MAPK. ERK2, MEK2, and NFKB (p65) mRNA expressions were decreased in the dose group administered TQ-SeNP at the 48th hour compared to that in the control group. However, it was not significant. The novel nanoparticle showed an antiproliferative effect in endometrial cancer cells. However, further studies are needed to increase the anticancer activity of the cell in the TQ-SeNP interaction.

Effect of Naoluoxintong formula and its split prescriptions on cerebral vascular regeneration in rats with the cerebral ischemia-reperfusion.

To observe regulatory effect of Naoluoxintong formula (, NLXT) and its split prescriptions on vascular regeneration of rats suffering from cerebral ischemia-reperfusion (IR) syndrome of Qi deficiency with blood stasis (QDBS). NLXT is the representative prescription of Yiqi Huoxue Tongluo decoction, and NLXT is divided into Yiqi herbs and Huoxue Tongluo herbs according to their efficacies. One hundred and eight specific-pathogen-free, clean-grade, Sprague-Dawley male rats were selected to prepare the classical rat model with QDBS due to middle artery ischemia-reperfusion using the multi-factor compound simulation approach. The animals were classified into sham operation (S), model (M), Nimodping (NMDP), NLXT, YQ and HXTL groups, each having 18 rats. Cerebral ischemia was reperfused after 2 h, and 24 h later, they were administered traditional Chinese medicine treatment for 14 d twice a day. Angiogenesis changes after NLXT administration to middle cerebral artery occlusion-reperfusion (MCAO/R) rats with QDBS were analyzed using the neurological deficit score and hematoxylin-eosin staining. Cerebral infarct area by 2,3,5-Triphenyltetrazolium chloride was detected, and the ultrastructure of the blood vessel in the ischemic frontoparietal cortex was observed by transmission electron microscopy. Angiopoietin 1 (Ang1), angiopoietin 2 (Ang2), vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), platelet endothelial cell adhesion molecule-1 (CD31), angiopoietin receptor 2 (Tie2), and P38 mitogen-activated protein kinase (MAPK) protein levels in the frontal and parietal cortex were quantified by immunofluorescence, reverse transcription-polymerase chain reaction, and Western blotting assays. Relative to the S group, VEGFA and VEGFR2 levels in the frontal and parietal cortex of group M were increased, and Ang1, Ang2, Tie2, CD31, and p38 MAPK levels remarkably increased (P < 0.05); cerebral infarct area was significant and pathological morphology and ultrastructure damage was obvious. Relative to the group M, VEGFA, VEGFR2, CD31, Ang1, Ang2, and Tie2 expression of group NLXT and NMDP remarkably elevated (P < 0.05) and infarct focus, pathological morphology and ultrastructure were significantly improved; VEGFA and VEGFR2 levels in the groups YQ and HXTL increased, and Ang1, Ang2, CD31, and Tie2 levels remarkably increased (P < 0.05); p38 MAPK levels in the three treatment groups decreased (P < 0.05). Relative to the group NLXT, the expression levels of p38 MAPK in group YQ and group HXTL were significantly increased, and the expression levels of other indicators were significantly decreased (P < 0.05). NLXT can promote the angiogenesis of the rat model of MCAO/R with QDBS by activating VEGFA and inhibiting P38 MAPK, and the effect is better than that of split prescription groups.

Klotho gene might antagonize ischemic injury in stroke rats by reducing the expression of AQP4 via P38MAPK pathway

ObjectivesThis study was aimed at exploring whether klotho improved neurologic function in rats with cerebral infarction by inhibiting P38 mitogen-activated protein kinase (MAPK) activation and thus down-regulating aquaporin 4 (AQP4). MethodsIn this study, we induced intracerebral Klotho overexpression in 6-week-old Sprague Dawley rats by injecting lentivirus carrying full-length rat Klotho cDNA into the lateral ventricle of the brain, followed by middle cerebral artery occlusion (MCAO) surgery after three days. Neurologic function was evaluated by neurological deficit scores. Infarct volume was assessed by 2,3,5-triphenyl tetrazolium chloride (TTC) staining. The expressions of Klotho, AQP4, and P38 MAPK were detected by Western blot and Immunofluorescence. Resultswhen rats were subjected to cerebral ischemia, their neurologic function was impaired, the protein expressions of klotho downregulated, the protein expressions of AQP4 and P38 MAPK increased, and the ratios of AQP4 and P-P38-positive area were significantly increased compared with the sham group rats. LV-KL-induced Klotho overexpression greatly improved neurobehavioral deficits and reduced infarct volume in MCAO rats. Klotho overexpression significantly reduced AQP4 and P38 MAPK pathway-related protein expression levels and the ratios of P-P38 and AQP4-positive area in MCAO rats. In addition, SB203580, a P38 MAPK signal pathway inhibitor, improved neurobehavioral deficits, reduced infarct volume, downregulated the expressions levels of AQP4 and P38 MAPK, and reduced the size of P-P38 and AQP4-positive area in MCAO rats. ConclusionKlotho could alleviate the infraction volume and neurological dysfunction in MCAO rats, and its mechanism may involve AQP4 expression downregulation by suppressing P38-MAPK activation.

Effect of the Mitogen-Activated Protein Kinase Pathway on the Erastin-Induced Ferroptosis of Molt-4 Cells.

The role of ferroptosis in human acute lymphoblastic leukemia and its possible molecular mechanisms of action are still unknown. In this study, harvested Molt-4 cells were exposed to different concentrations of erastin, and their proliferation capacity was tested by using the cell counting kit-8 assay. Lipid peroxidation levels were detected through flow cytometry. Mitochondrial alterations were observed through transmission electron microscopy. The expression levels of SLC7A11, glutathione peroxidase 4 (GPX4), and mitogen-activated protein kinase (MAPK) were detected by using quantitative real-time PCR and Western blot analysis. This study found that erastin inhibited the growth of Molt-4 cells. This inhibitory effect could be partially reversed by the ferroptosis inhibitor Ferrostatin-1 and the p38 MAPK inhibitor. The mitochondria of Molt-4 cells treated with erastin shortened and condensed. Compared with those in the control group, the levels of reactive oxygen species and malondialdehyde had increased, whereas the levels of glutathione had decreased in the treatment group. The treatment of Molt-4 cells with erastin decreased the levels of SLC7A11 and GPX4 mRNA and increased the expression levels of p38 MAPK, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase. These findings suggested that erastin caused the ferroptosis of Molt-4 cells. This process may be correlated with the inhibition of the cystine/glutamate antiporter system and GPX4 and the activation of p38 MAPK and ERK1/2.

Heat shock protein 40 of Streptococcus pneumoniae induces immune response of human dendritic cells via TLR4-dependent p38 MAPK and JNK signaling pathways.

Heat shock protein 40 (HSP40) is a vaccine adjuvant candidate for Streptococcus pneumoniae. The mechanism by which HSP40 activates the human dendritic cells (DCs) is unclear. DCs were isolated from human peripheral blood and their markers (HLA-DR, CD86, CD83, and CD80) were detected by flow cytometry. The messengerRNA (mRNA) and secretion levels of inflammary cytokines were measured after DCs were stimulated with recombinant HSP40 (rHSP40). Short hairpin RNAs were used to knock down toll-like receptor 2 (TLR2) and TLR4. The TLR2- or TLR4-deficient DCs were treated with lipopolysaccharides, rHSP40, or peptidoglycan, and then the secretion levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured. Moreover, the secretion levels of TNF-α and IL-6 were measured after DCs were treated with mitogen-activated protein kinase (MAPK) inhibitors including SB203580, SP600125, and U0126. In addition, the phosphorylation levels of p38 MAPK and Jun N-terminal kinase (JNK) in DC cells were determined using western blot analysis after treatment with rHSP40 for different times. DCs were successfully isolated and cultured. rHSP40 treatment significantly increased cytokine levels in a concentration-dependent manner. TLR4 deficiency, but not TLR2 deficiency, significantly suppressed the rHSP40-induced secretion of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). SB203580 and SP600125 significantly inhibited the rHSP40-induced secretion of TNF-α and IL-6. rHSP40 significantly enhanced the phosphorylation of p38 MAPK and JNK. HPS40 stimulates the immune response of DCs via the p38 MAPK and JNK signaling pathways, which depend on TLR4.

Anti-inflammatory mechanism of active ingredients in Jingfang Mixture based on network pharmacology and experimental verification

The present study aimed to explore the regulatory targets and anti-inflammatory mechanism of Jingfang Mixture based on network pharmacology and animal tests. The active ingredients of Jingfang Mixture and the corresponding targets were screened out by the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP). Inflammation-related targets were searched from GeneCards and DisGeNET, and the targets of active ingredients of Jingfang Mixture against inflammation were obtained. The protein-protein interaction(PPI) network was analyzed by STRING and plotted. Gene ontology(GO) function and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses were carried out based on DAVID. The results of network pharmacology showed 159 active ingredients and 276 targets of Jingfang Mixture and 664 inflammation-related targets were screened out, and 90 targets of active ingredients of Jingfang Mixture against inflammation were obtained. As revealed by the PPI network, protein kinase B1(AKT1), caspase-3(CASP3), interleukin-1β(IL1 B), prostaglandin-endoperoxide synthase 2(PTGS2), and tumor necrosis factor(TNF) might be the key proteins for the anti-inflammatory effect of Jingfang Mixture. KEGG enrichment analysis demonstrated the pathways involved TNF, nuclear factor-kappa B(NF-κB), and mitogen-activated protein kinase(MAPK). The anti-inflammatory effect of Jingfang Mixture was explored through the mouse model of urticaria. The results indicated that Jingfang Mixture could down-regulate the phosphorylation levels of p38 MAPK, extracellular regulated protein kinases(ERK1/2), and NF-κB. The present study revealed the anti-inflammatory effect of Jingfang Mixture with multi-component and multi-target characteristics, which is expected to provide a scientific basis and important support for further research, development, and application.

Dimethyl Fumarate Ameliorates Paclitaxel-Induced Neuropathic Pain in Rats.

BackgroundPaclitaxel (PTX)-induced peripheral neuropathy (PIPN) is nonresponsive to the currently available analgesics. Previous studies have shown the role of oxidative stress and central sensitization in the development of peripheral neuropathy. Dimethyl fumarate (DMF) acts as a nuclear factor erythroid-2-related factor 2 (Nrf2) activator with neuroprotective benefits and is approved for use in multiple sclerosis.Materials and methodsIn the current research, we evaluated the efficacy of DMF on paclitaxel-induced peripheral neuropathy in rats. Every alternate day for one week, paclitaxel 2 mg/kg dose was injected to establish a rat model of PIPN. Animals were treated with 25 mg/kg and 50 mg/kg of DMF. All the animals were assessed for thermal hyperalgesia, cold allodynia, and mechanical allodynia once a week. The gene expression of Nrf2 and the levels of pro-inflammatory mediators (interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and IL-1β) were quantified in the sciatic nerves of these rats. The levels of p38 mitogen-activated protein kinase (MAPK) and brain-derived neurotrophic factor (BDNF) were quantified in the dorsal horn of the spinal cord.ResultsDMF significantly attenuated paclitaxel-induced thermal hyperalgesia and cold/mechanical allodynia. A significant decrease in the levels of pro-inflammatory cytokines with the levels of p38 MAPK and BDNF was observed in the DMF-treated animals. DMF treatment significantly upregulated the gene expression of Nrf2 in the sciatic nerve.ConclusionThese findings suggest that DMF prevented the development of PIPN in rats through the activation of Nrf2 and the inhibition of p38 MAPK and BDNF.

Improved Sleep, Memory, and Cellular Pathological Features of Tauopathy, Including the NLRP3 Inflammasome, after Chronic Administration of Trazodone in rTg4510 Mice.

Several cellular pathways contribute to neurodegenerative tauopathy-related disorders. Microglial activation, a major component of neuroinflammation, is an early pathologic hallmark that correlates with cognitive decline, while the unfolded protein response (UPR) contributes to synaptic pathology. Sleep disturbances are prevalent in tauopathies and may also contribute to disease progression. Few studies have investigated whether manipulations of sleep influence cellular pathologic and behavioral features of tauopathy. We investigated whether trazodone, a licensed antidepressant with hypnotic efficacy in dementia, can reduce disease-related cellular pathways and improve memory and sleep in male rTg4510 mice with a tauopathy-like phenotype. In a 9 week dosing regimen, trazodone decreased microglial NLRP3 inflammasome expression and phosphorylated p38 mitogen-activated protein kinase levels, which correlated with the NLRP3 inflammasome, the UPR effector ATF4, and total tau levels. Trazodone reduced theta oscillations during rapid eye movement (REM) sleep and enhanced REM sleep duration. Olfactory memory transiently improved, and memory performance correlated with REM sleep duration and theta oscillations. These findings on the effects of trazodone on the NLRP3 inflammasome, the unfolded protein response and behavioral hallmarks of dementia warrant further studies on the therapeutic value of sleep-modulating compounds for tauopathies.SIGNIFICANCE STATEMENT Dementia and associated behavioral symptoms such as memory loss and sleep disturbance are debilitating. Identifying treatments that alleviate symptoms and concurrently target cellular pathways contributing to disease progression is paramount for the patients and their caregivers. Here we show that a chronic treatment with trazodone, an antidepressant with positive effects on sleep, has beneficial effects on several cellular pathways contributing to neuroinflammation and tau pathology, in tauopathy-like rTg4510 mice. Trazodone also improved rapid eye movement (REM) sleep, the slowing of brain oscillations, and olfactory memory disturbances, which are all early symptoms observed in Alzheimer's disease. Thus, trazodone and compounds with REM sleep-promoting properties may represent a promising treatment approach to reduce the early symptoms of tauopathy and slow down disease progression.

Mechanism exploration of ancient pharmaceutic processing (Paozhi) improving the gastroprotective efficacy of Aucklandiae Radix

Ethnopharmacological relevanceProcessing, also called Paozhi in Chinese, is an ancient Chinese pharmaceutic processing technique developed along with the Chinese herbal medicines (CHMs). The understanding of the mechanism of Paozhi has been investigated for several decades. Aucklandiae Radix (CAR) and its roasted processed products are all used in indigestion as a kind of CHMs. Processed Aucklandiae Radix (PAR) had a stronger effect to protect gastric mucosa than CAR, while the main compounds in CAR were reduced sharply after being processed. The underlying mechanism of this phenomenon is still unclear. Aim of the studyThis study was aimed to evaluate whether PAR have a stronger gastroprotective effect than CAR and the underlying mechanisms of such circumstance. Materials and methodsUltra-fast liquid chromatography coupled with quadrupole time of flight mass spectrometry (UFLC-QTOF-MS/MS) coupled with multivariate statistical analyses was employed to explore chemical compounds which had a relatively stable content in PAR. Based on the compounds selected as the research object, network pharmacology was applied to visualize the relationships between the selected components and the gastroprotective-related targets from disease database, at the same time the possible intervention path of CAR/PAR which might be responsible for the effect of CAR/PAR on gastritis-induced rats was also built. Then, the key proteins were detected by western blotting to verify and compare the pharmacological effects of CAR/PAR. ResultsThrough UFLC-QTOF-MS/MS and orthogonal partial least squares discriminant analysis (OPLS-DA), sixteen compounds stable in PAR were discovered, of which saussureamine C and saussureamine B were estimated as the core compounds to exert gastroprotective in PAR predicted by network pharmacology analysis. Under the guide of KEGG pathway enrichment analysis, PI3K/AKT, p38 MAPK (Mitogen-activated protein kinase) and nuclear factor-kappa B (NF-κB) signaling pathways were forecasted as the possible healing mechanisms of CAR/PAR, and that result was verified by the experiments in vivo. PAR performed a stronger ability to reduce the level of p38 MAPK and NF-κB p65 than CAR, which may partially explain the different ability of CAR/PAR against gastric mucosa damage. Conclusion: This study clarified that although Paozhi entailed a sharp decrease on the main compounds of CAR, there were some compounds which were not sensitive to high temperature and preserved in PAR and had a relative higher content in PAR than in CAR. PAR has stronger influence on MAPKs/NF-κB signaling pathway than CAR, which may reveal that the stronger gastroprotective effect of PAR perhaps rely on the constitutions with a higher relative abundance after Paozhi. The present research combined UFLC-QTOF-MS/MS and network pharmacology deeply investigated the impact of the roasted processing on the chemical constitutions and gastroprotective effect of CAR and offered reference for the clinical application of CAR/PAR.

Nano-Curcumin Prevents Cardiac Injury, Oxidative Stress and Inflammation, and Modulates TLR4/NF-κB and MAPK Signaling in Copper Sulfate-Intoxicated Rats.

Copper (Cu) is essential for a plethora of biological processes; however, its high redox reactivity renders it potentially toxic. This study investigated the protective effect of curcumin (CUR) and nano-CUR (N-CUR) against Cu cardiotoxicity, emphasizing the role of oxidative stress, TLR4/NF-κB and mitogen-activated protein kinase (MAPK) signaling and cell death in rats. Rats received 100 mg/kg copper sulfate (CuSO4), a pesticide used for repelling pests, and were concurrently treated with CUR or N-CUR for 7 days. Cu caused cardiac injury manifested by elevated serum cardiac troponin I (cTnI), creatine kinase (CK)-MB, and lactate dehydrogenase (LDH), as well as histopathological alterations. Cardiac malondialdehyde (MDA), NF-κB p65, TNF-α, and IL-6 were increased, and reduced glutathione (GSH), superoxide dismutase (SOD) and catalase were decreased in Cu-treated rats. CUR and N-CUR prevented cardiac tissue injury, decreased serum cTnI, CK-MB, and LDH, and cardiac MDA, NF-κB p65, TNF-α, and IL-6, and enhanced cellular antioxidants. CUR and N-CUR downregulated TLR4 and AP-1, and decreased the phosphorylation levels of p38 MAPK, JNK, and ERK1/2. In addition, CUR and N-CUR increased cardiac Bcl-2 and BAG-1, decreased Bax and caspase-3, and prevented DNA fragmentation. In conclusion, N-CUR prevents Cu cardiotoxicity by attenuating oxidative injury, inflammatory response, and apoptosis, and modulating TLR4/NF-κB and MAPK signaling. The cardioprotective effect of N-CUR was more potent than the native form.

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.

3,5-dicaffeoyl‑epi-quinic acid from Atriplex gmelinii enhances the osteoblast differentiation of bone marrow-derived human mesenchymal stromal cells via WnT/BMP signaling and suppresses adipocyte differentiation via AMPK activation

BackgroundImpaired bone formation is one of the reasons behind osteoporosis. Alterations in the patterns of mesenchymal stromal cell differentiation towards adipocytes instead of osteoblasts contribute to osteoporosis progression. Natural anti-osteoporotic agents are effective and safe alternatives for osteoporosis treatment. PurposeIn this context, 3,5-dicaffeoyl‑epi-quinic acid (DCEQA) which is a derivative of chlorogenic acid with reported bioactivities was studied for its osteogenic differentiation enhancing potential in vitro. MethodsAnti-osteoporotic effects of DCEQA were investigated in human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) which were induced to differentiate into osteoblasts or adipocytes with or without DCEQA treatment. Changes in the osteogenic and adipogenic markers such as ALP activity and lipid accumulation, respectively, were observed along with differentiation-specific activation of mitogen activated protein kinase (MAPK) pathways. ResultsAt 10 μM concentration, DCEQA increased the proliferation of bone marrow-derived human mesenchymal stromal cells (hBM-MSCs) during osteoblast differentiation. The expression of osteogenic markers ALP, osteocalcin, Runx2, BMP2 and Wnt 10a was upregulated by DCEQA treatment. The ALP activity and extracellular mineralization were also increased. DCEQA elevated the phosphorylation levels of p38 and JNK MAPKs as well as the activation of β-catenin and Smad1/5. DCEQA suppressed the lipid accumulation and downregulated expression of adipogenic markers PPARγ, C/EBPα and SREBP1c in adipo-induced hBM-MSCs. DCEQA also decreased the phosphorylation of p38 and ERK MAPKs and stimulated the activation of AMPK in hBM-MSC adipocytes. ConclusionDCEQA was suggested to enhance osteoblast differentiation via stimulating Wnt/BMP signaling. The adipocyte differentiation inhibitory effect of DCEQA was suggested to arise from its ability to increase AMPK phosphorylation. Overall, DCEQA was shown to possess osteogenesis enhancing and adipogenesis inhibitory properties which might facilitate its use against osteoporotic conditions.

Molecular characterization of p38 MAPK and tissue-specific expression under cadmium stress in red swamp crayfish (Procambarus clarkii)

Keeping harmful pollutants out of some crucial tissues as much as possible is a key trait for the organism to survive in adverse conditions, such as in heavy-metal contaminated aquatic environments. In the current study, it was hypothesized that the p38 Mitogen-activated Protein Kinase (MAPK) controls the distribution of cadmium (Cd) in red swamp crayfish (Procambarus clarkii) by regulating the accumulation of Cd in different tissues under Cd-stressed conditions. To test this hypothesis, this study analyzed the p38 MAPK gene and compared the differential expression levels in the heart, antennal gland, gill, hepatopancreas, and muscles. Differences in expression levels of p38 MAPK gene between different tissues were conducted under controlled Cd exposure. This study found that the expression of p38 MAPK is tissue-specific in all tested samples under non-stressed condition. Under Cd-stressed condition and with the prolongation of Cd exposure time, the content of Cd in all examined tissues of P. clarkii has substantially increased compared to the control, although the Cd contents in the heart, antennal gland, and muscle remained relatively lower than those observed in the hepatopancreas. Consequently, the levels of p38 MAPK in the heart, antennal gland, and muscle were higher than the level in the hepatopancreas. These results indicate that p38 MAPK regulates the distribution and accumulation of Cd in different tissues of P. clarkii under Cd-stressed condition. Furthermore, the results suggested that the higher expression of p38 MAPK played a crucial role in keeping Cd out of the tissues in the Cd-rich aquatic environment to maintain the normal physiological function of the red swamp crayfish, a process necessary for survival and growth.

Effect of imatinib on DOCA-induced myocardial fibrosis in rats through P38 MAPK signaling pathway.

To explore the role of imatinib in desoxycorticosterone acetate (DOCA)-induced myocardial fibrosis in rats by the p38 mitogen-activated protein kinase (MAPK) signaling pathway. Normal group (n=20), DOCA induction group (n=20), and imatinib treatment group (treatment group, n=20) were set up. Then, the cardiac function was examined via magnetic resonance imaging (MRI) and echocardiography (ECG) on the 21st d after modeling. Alkaline phosphatase (ALP) and myocardial function index creatine kinase-MB (CK-MB) were detected. The enzyme-linked immunosorbent assay (ELISA) was performed to measure tumor necrosis factor-gamma (TNF-γ) and interleukin-6 (IL-6). Hematoxylin-eosin (HE) staining assay was carried out to observe the pathological changes in myocardial tissues. Quantitative Polymerase Chain Reaction (qPCR) and Western blotting were employed to measure the expression levels of important myocardial fibrosis-related genes [checkpoint kinase 1 (Chek1) and alpha-smooth muscle actin (α-SMA)], as well as genes and proteins of the p38 MAPK signaling pathway. In comparison with the normal group, DOCA induction group had significantly lowered fractional shortening (FS, %) and ejection fraction (EF, %), but overtly increased left ventricular end-diastolic dimension (LVEDd) and left ventricular end-systolic dimension (LVESd), as well as levels of serum ALP, alanine aminotransferase (ALT), and CK-MB. Besides, the levels of TNF-γ, IL-6, and IL-1β were notably raised in the DOCA induction group. HE staining results showed that myocardial injury was more severe in DOCA induction group. The results of the gene detection revealed that the expression levels of Chek1, α-SMA, p38 MAPK, and JNK were evidently higher in DOCA induction group than those in the imatinib treatment group (p<0.05), and the expression of p38 MAPK protein in the rat myocardial tissues was remarkably lower in the treatment group than that in the DOCA induction group (p<0.05). Imatinib can regulate the repair of myocardial injury caused by DOCA-induced myocardial fibrosis in rats by repressing the p38 MAPK signaling pathway.

Resveratrol Modulates miR-34a in Cardiotoxicity Induced by Isoproterenol.

Acute myocardial infarction is a major cause of death and disability worldwide. This study was designed to elucidate the effect of resveratrol (RES) in isoproterenol (ISO)-challenged myocardial injury in rats. Male Sprague-Dawley rats were randomly allocated to four groups (10 rats/group): negative, control positive ISO (85 mg/kg), Propranolol/ISO, and RES/ISO. RES (50 mg/kg) improved plasma lactate dehydrogenase, creatine kinase, and cardiac troponin T; brain natriuretic peptide, interleukin-10, vascular endothelial growth factor, and transforming growth factor-β1; as well as cardiac superoxide dismutase, malondialdehyde, and total protein kinase-1 (Akt-1) levels. In addition, RES reduced the expression of cardiac inducible nitric oxide synthase and microRNA-34a, as well as p38 mitogen-activated protein kinase levels compared with positive control group. In conclusion, RES could reduce the degree of MI induced by ISO by improving the antioxidant, antiapoptotic, and anti-inflammatory capacities of the body.

Erythromycin reverses cigarette smoke extract-induced corticosteroid insensitivity by inhibition of the JNK/c-Jun pathway

Corticosteroid insensitivity is a feature of airway inflammation in chronic obstructive pulmonary disease (COPD). Erythromycin exhibits anti-inflammatory activity in COPD, but the concrete mechanism is still unclear. This study aimed to investigate the effects of erythromycin on corticosteroid sensitivity in peripheral blood mononuclear cells (PBMCs) and U937 cells (a human monocytic cell line). PBMCs were collected from non-smokers, healthy smoker volunteers, and COPD subjects. U937 cells were incubated with or without erythromycin and stimulated with TNF-α in the presence or absence of cigarette smoke extract (CSE). The dexamethasone (Dex) concentration required to achieve 50% inhibition of TNF-α-induced interleukin (IL)-8 production was determined and the mitogen-activated protein kinase (MAPK)/Activator protein-1 (AP-1) pathway was also evaluated. Erythromycin improved corticosteroid sensitivity in PBMCs obtained from COPD patients and CSE-treated U937 cells. This improvement in corticosteroid sensitivity was associated with reduced c-Jun expression, which resulted from the inhibition of P38 Mitogen-activated protein kinase (P38MAPK), extracellular signal-regulated protein kinase (ERK)1/2, and c-Jun N-terminal kinase (JNK) phosphorylation. Erythromycin had no effects on the phosphorylated and total protein expression levels of P38MAPK and ERK; however, it induced inhibition of the phosphorylated and total protein expression levels of JNK. This study provides evidence that erythromycin restores corticosteroid sensitivity in PBMCs and U937 cells. JNK inhibition by erythromycin restores corticosteroid sensitivity via the inhibition of c-Jun expression. Thus, JNK/c-Jun is a potential novel therapeutic target for COPD.

Effect of ulinastatin on myocardial ischemia-reperfusion injury through JNK and P38 MAPK signaling pathways.

The aim of this study was to investigate the effect of ulinastatin (UTI) on myocardial ischemia-reperfusion injury (MIRI) through the c-Jun N-terminal kinase (JNK) signaling pathway and p38 mitogen-activated protein kinase (MAPK) signaling pathway. Healthy adult male Sprague-Dawley (SD) rats were randomly divided into 5 groups, including the sham group (n=10), MIRI group (model group, n=10), UTI group (n=10), UTI + JNK inhibitor SP600125 (UTI+SP600125 group, n=10) and UTI + p38 MAPK inhibitor SB203580 (UTI+SB203580 group, n=10). Hemodynamics, myocardial infarction and the messenger ribonucleic acid (mRNA) expressions of p38 MAPK, JNK, superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP) were compared among groups. The protein levels of p38 MAPK and JNK in serum were detected via Western blotting. Furthermore, the correlations of serum p38 MAPK and JNK with TNF-α were analyzed. In the UTI group, the left ventricular systolic pressure (LVSP), the left ventricular end-diastolic pressure (LVEDP) and maximal rate of increase of the left ventricular pressure (+dp/dtmax) were significantly higher than those of the model group. However, the maximal rate of the decrease of the left ventricular pressure (-dp/dtmax), infarction area and ischemia area were significantly smaller than those of the model group. LVSP, LVEDP and +dp/dtmax in UTI+SP600125 group and UTI+SB203580 group were markedly higher than those of the UTI group. Meanwhile, the mRNA expressions of p38 MAPK and JNK in the UTI group were significantly lower than those of the model group. However, the mRNA expression levels of p38 MAPK and JNK in UTI+SP600125 group and UTI+SB203580 group were remarkably higher than the UTI group. Besides, the UTI group showed a markedly higher level of SOD and significantly lower levels of MDA, NO, TNF-α, IL-6 and hs-CRP than the model group. Furthermore, UTI+SP600125 group and UTI+SB203580 group showed significantly higher levels of MDA, NO, TNF-α, IL-6 and hs-CRP than the UTI group. The protein levels p38 MAPK and JNK were remarkably lower in the UTI group than those of the model group. However, they were remarkably higher in UTI+SP600125 group and UTI+SB203580 group than the UTI group. In addition, both p38 MAPK and JNK proteins were positively correlated with TNF-α (r=0.983 and 0.892, p=0.043 and p=0.033). UTI may inhibit MIRI caused by p38 MAPK signaling pathway and JNK signaling pathway by down-regulating TNF-α expression, thereby protecting and improving MIR.

Melatonin inhibits the inflammation and apoptosis in rats with diabetic retinopathy via MAPK pathway.

To investigate the effect of melatonin on diabetic retinopathy rats through the mitogen-activated protein kinase (MAPK) pathway. A total of 48 Sprague Dawley (SD) rats were randomly divided into normal group (n=12), model group (n=12), melatonin group (n=12), and inhibitor group (n=12). The rats in normal group received no treatment. Those in model group, melatonin group, and inhibitor group were prepared into models of diabetic retinopathy and intraperitoneally injected with normal saline, melatonin, and SB 203580, respectively. After 7 days of intervention, the materials were taken. The expressions of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected through immunohistochemistry. Western blotting was employed to determine the protein expression levels of p38 MAPK, phosphorylated (p)-p38 MAPK, and cysteinyl aspartate specific proteinase-3 (Caspase-3). The messenger ribonucleic acid (mRNA) expression levels of Bax and Bcl-2 were measured via quantitative Polymerase Chain Reaction (qPCR). Enzyme-linked immunosorbent assay (ELISA) was performed to detect the levels of serum interleukin-1β (IL-1β) and IL-18. The apoptosis was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL). Based on immunohistochemistry, model group, melatonin group, and inhibitor group exhibited significantly increased positive expression of Bax but notably decreased positive expression of Bcl-2 in comparison with normal group (p<0.05). Compared with those in model group, the positive expression of Bax was clearly reduced, while the positive expression of Bcl-2 was overtly raised in melatonin group and inhibitor group (p<0.05). The results of Western blotting showed that there was no difference in the protein expression of p38 MAPK among all groups (p>0.05). Compared with normal group, the other three groups had remarkably elevated protein expressions of p-p38 MAPK and Caspase-3 (p<0.05). The protein expressions of p-p38 MAPK and Caspase-3 in melatonin group and inhibitor group were significantly lower than those in model group decreased (p<0.05). QPCR assay revealed that the mRNA expression of Bax was markedly lower in normal group than that in the other three groups, while the mRNA expression of Bcl-2 was significantly higher in normal group than that in the other three groups (p<0.05). Compared with model group, melatonin group, and inhibitory group showed clearly declined mRNA expression level of Bax and notably increased mRNA expression level of Bcl-2 (p<0.05). TUNEL results revealed that the apoptosis rate was remarkably elevated in the other three groups compared with that in normal group (p<0.05). In comparison with model group, melatonin group and inhibitor group exhibited significantly reduced apoptosis rate (p<0.05). Melatonin inhibits the inflammation and apoptosis in rats with diabetic retinopathy by repressing the MAPK pathway.