Parabens promotes invasive properties of multiple human cells: A potential cancer-associated adverse outcome pathway

Parabens are esters of p-hydroxybenzoic acid, which have been used as preservatives and considered safe for nearly a century, until the last two decades when concerns began to be raised about their association with cancers. Knowledge of the mode of action of parabens on the metastatic properties of different cancer cells is still very limited. In the present study, we investigated the effects of methylparaben (MP) and propylparaben (PP) on cell invasion and/or migration in multiple human cancerous and noncancerous cells, including hepatocellular carcinoma cells (HepG2), cervical carcinoma cells (HeLa), breast carcinoma cells (MCF-7), and human placental trophoblasts (HTR-8/SVneo). MP and PP at concentrations in a range of 5-500 μg/L significantly promoted the invasion of four cell lines, with a minimum effective concentration of 5 μg/L. MP and PP up-regulated the expression levels and enzymatic activities of matrix metalloproteinase 2 and 9 (MMP2 and MMP9), as well as altered the expression of the tissue inhibitors of metalloproteinase 1 and 2 (TIMP1 and TIMP2) in four cell lines, suggesting MMPs/TIMPs as potential key events (KEs) for paraben-induced cell invasion. Activation of the p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal protein kinases 1/2 (JNK1/2) signaling pathways was required for MP- and PP-promoted invasion of four cell lines, suggesting MAPK signaling pathways as candidates for KEs in cancer or noncancerous cells response to paraben exposure. This study showed for the first time that the two widely used parabens, MP and PP, promoted invasive capacity of multiple human cells through a common mode of action. This study provides evidence for the establishment of a potential cancer-associated AOP for parabens based on pathway-specific mechanism(s), which contributes towards assessing the health risks of these environmental chemicals.

Overexpressing of the GIPC1 protects against pathological cardiac remodelling

OBJECTIVE

Pathological cardiac remodelling, including cardiac hypertrophy and fibrosis, is a key pathological process in the development of heart failure. However, effective therapeutic approaches are limited. The β-adrenergic receptors are pivotal signalling molecules in regulating cardiac function. G-alpha interacting protein (GAIP)-interacting protein, C-terminus 1 (GIPC1) is a multifunctional scaffold protein that directly binds to the C-terminus of β1-adrenergic receptor (β1-adrenergic receptor). However, little is known about its roles in heart function. Therefore, we investigated the role of GIPC1 in cardiac remodelling and its underlying molecular mechanisms.

METHODS

Pathological cardiac remodelling in mice was established via intraperitoneal injection of isoprenaline for 14 d or transverse aortic constriction surgery for 8 weeks. Myh6-driving cardiomyocyte-specific GIPC1 conditional knockout (GIPC1 cKO) mice and adeno-associated virus 9 (AAV9)-mediated GIPC1 overexpression mice were used. The effect of GIPC1 on cardiac remodelling was assessed using echocardiographic, histological, and biochemical analyses.

RESULTS

GIPC1 expression was consistently reduced in the cardiac remodelling model. GIPC1 cKO mice exhibited spontaneous abnormalities, including cardiac hypertrophy, fibrosis, and systolic dysfunction. In contrast, AAV9-mediated GIPC1 overexpression in the heart attenuated isoproterenol-induced pathological cardiac remodelling in mice. Mechanistically, GIPC1 interacted with the β1-adrenergic receptor and stabilised its expression by preventing its ubiquitination and degradation, maintaining the balance of β1-adrenergic receptor/β2-adrenergic receptor, and inhibiting hyperactivation of the mitogen-activated protein kinase signalling pathway.

CONCLUSIONS

These results suggested that GIPC1 plays a cardioprotective role and is a promising therapeutic target for the treatment of cardiac remodelling and heart failure.

Protective effect of oxytocin on vincristine-induced gastrointestinal dysmotility in mice

Aims: Vincristine (VCR), an antineoplastic drug, induces peripheral neuropathy characterized by nerve damage, limiting its use and reducing the quality of life of patients. VCR causes myenteric neuron damage, inhibits gastrointestinal motility, and results in constipation or paralytic ileus in patients. Oxytocin (OT) is an endogenous neuropeptide produced by the enteric nerve system, which regulates gastrointestinal motility and exerts neuroprotective effects. This study aimed to investigate whether OT can improve VCR-induced gastrointestinal dysmotility and evaluate the underlying mechanism. Methods: Mice were injected either with saline or VCR (0.1 mg/kg/d, i. p.) for 14 days, and OT (0.1 mg/kg/d, i.p.) was applied 1 h before each VCR injection. Gastrointestinal transit and the contractile activity of the isolated colonic segments were assessed. The concentration of OT in plasma was measured using ELISA. Immunofluorescence staining was performed to analyze myenteric neurons and reactive oxygen species (ROS) levels. Furthermore, the indicators of oxidative stress were detected. The protein expressions of Nrf2, ERK1/2, P-ERK1/2, p38, and P-p38 in the colon were tested using Western blot. Results: VCR reduced gastrointestinal transit and the responses of isolated colonic segments to electrical field stimulation and decreased the amount of neurons. Furthermore, VCR reduced neuronal nitric oxide synthase and choline acetyltransferase immunopositive neurons in the colonic myenteric nerve plexus. VCR increased the concentration of OT in plasma. Exogenous OT pretreatment ameliorated the inhibition of gastrointestinal motility and the injury of myenteric neurons caused by VCR. OT pretreatment also prevented the decrease of superoxide dismutase activity, glutathione content, total antioxidative capacity, and Nrf2 expression, the increase of ROS levels, and the phosphorylation of ERK1/2 and p38 MAPK following VCR treatment. Conclusion: Our results suggest that OT pretreatment can protect enteric neurons from VCR-induced injury by inhibiting oxidative stress and MAPK pathways (ERK1/2, p38). This may be the underlying mechanism by which it alleviates gastrointestinal dysmotility.

MAP3K4 kinase action and dual role in cancer

It is commonly known that the MAPK pathway is involved in translating environmental inputs, regulating downstream reactions, and maintaining the intrinsic dynamic balance. Numerous essential elements and regulatory processes are included in this pathway, which are essential to its functionality. Among these, MAP3K4, a member of the serine/threonine kinases family, plays vital roles throughout the organism's life cycle, including the regulation of apoptosis and autophagy. Moreover, MAP3K4 can interact with key partners like GADD45, which affects organism's growth and development. Notably, MAP3K4 functions as both a tumor promotor and suppressor, being activated by a variety of factors and triggering diverse downstream pathways that differently influence cancer progression. The aim of this study is to provide a brief overview of physiological functions of MAP3K4 and shed light on its contradictory roles in tumorigenesis.

Plumbagin alleviates temporomandibular joint osteoarthritis progression by inhibiting chondrocyte ferroptosis via the MAPK signaling pathways

AIMS

The acceleration of osteoarthritis (OA) development by chondrocytes undergoing ferroptosis has been observed. Plumbagin (PLB), known for its potent antioxidant and anti-inflammatory properties, has demonstrated promising potential in the treatment of OA. However, it remains unclear whether PLB can impede the progression of temporomandibular joint osteoarthritis (TMJOA) through the regulation of ferroptosis. The study aims to investigate the impact of ferroptosis on TMJOA and assess the ability of PLB to modulate the inhibitory effects of ferroptosis on TMJOA.

MATERIALS AND METHODS

The study utilized an in vivo rat model of unilateral anterior crossbite (UAC)-induced TMJOA and an in vitro study of chondrocytes exposed to H2O2 to create an OA microenvironment. Various experiments including cell viability assessment, quantitative RT-PCR, western blot analysis, histology, and immunofluorescence were conducted to examine the impact of ferroptosis on TMJOA and evaluate the potential of PLB to mitigate the inhibitory effects of ferroptosis on TMJOA. Additionally, RNA-seq and bioinformatics analysis were performed to investigate the underlying mechanism by which PLB regulates ferroptosis in TMJOA.

RESULTS

Fer-1 demonstrated its potential in mitigating the advancement of TMJOA through its inhibitory effects on ferroptosis and matrix degradation in chondrocytes, thereby substantiating the role of ferroptosis in the pathogenesis of TMJOA. Furthermore, the observed protective impact of PLB on cartilage implied that PLB can modulate the inhibition of ferroptosis in TMJOA by regulating the MAPK signaling pathways.

CONCLUSIONS

PLB alleviates TMJOA progression by suppressing chondrocyte ferroptosis via MAPK pathways, indicating PLB to be a potential therapeutic strategy for TMJOA.

Postnatal skeletal muscle myogenesis governed by signal transduction networks: MAPKs and PI3K-Akt control multiple steps

Skeletal muscle myogenesis represents one of the most intensively and extensively examined systems of cell differentiation, tissue formation, and regeneration. Muscle regeneration provides an in vivo model system of postnatal myogenesis. It comprises multiple steps including muscle stem cell (or satellite cell) quiescence, activation, migration, myogenic determination, myoblast proliferation, myocyte differentiation, myofiber maturation, and hypertrophy. A variety of extracellular signaling and subsequent intracellular signal transduction pathways or networks govern the individual steps of postnatal myogenesis. Among them, MAPK pathways (the ERK, JNK, p38 MAPK, and ERK5 pathways) and PI3K-Akt signaling regulate multiple steps of myogenesis. Ca2+, cytokine, and Wnt signaling also participate in several myogenesis steps. These signaling pathways often control cell cycle regulatory proteins or the muscle-specific MyoD family and the MEF2 family of transcription factors. This article comprehensively reviews molecular mechanisms of the individual steps of postnatal skeletal muscle myogenesis by focusing on signal transduction pathways or networks. Nevertheless, no or only a partial signaling molecules or pathways have been identified in some responses during myogenesis. The elucidation of these unidentified signaling molecules and pathways leads to an extensive understanding of the molecular mechanisms of myogenesis.

Polystyrene nanoplastics induce apoptosis of human kidney proximal tubular epithelial cells via oxidative stress and MAPK signaling pathways

Polystyrene nanoplastics (PS-NPs) have recently been found to be present in human blood and kidney. However, the renal toxicity of PS-NPs and the underlying mechanisms have not been fully elucidated. Here, we found that exposure of PS-NPs induced apoptosis of human renal proximal tubular epithelial cells (HK-2) in a size- and dose-dependent manner as revealed by AnnexinV-FITC assay. In addition, PS-NPs promoted ROS production and caused structure changes of mitochondrial and endoplasmic reticulum. Mechanistically, transcriptional sequencing indicated the involvement of MAPK pathway in apoptosis, which was further confirmed by the upregulation of p-p38, p-ERK, CHOP, BAX, cytochrome C, and caspase 3 expression. This study clarified the molecular mechanism underlying PS-NP-induced apoptosis in HK-2 cells and contributed to our risk estimation of PS-NPs in human kidney.

The RasGEF MoCdc25 regulates vegetative growth, conidiation and appressorium-mediated infection in the rice blast fungus Magnaporthe oryzae

Ras guanine nucleotide exchange factors (RasGEFs) can trigger Ras GTPase activities and play important roles in controlling various cellular processes in eukaryotes. Recently, it has been exhibited that RasGEF Cdc25 regulates morphological differentiation and pathogenicity in several plant pathogenic fungi. However, the role of RasGEFs in Magnaporthe oryzae is largely unknown. In this study, we identified and functionally characterized a RasGEF gene MoCDC25 in M. oryzae, which is orthologous to Saccharomyces cerevisiae CDC25. Targeted gene deletion mutants (ΔMocdc25) were completely nonpathogenic and were severely impaired in hyphal growth, conidiation and appressorium formation. The mutants exhibited highly sensitive response to osmotic, cell wall integrity or oxidative stresses. MoCdc25 physically interacts with the MAPK scaffold Mst50 and the putative Cdc42GEF MoScd1 in yeast two-hybrid assays. Moreover, we found that MoCdc25 was involved in regulating the phosphorylation of the MAP kinases (Pmk1, Mps1, and Osm1). In addition, the intracellular cAMP content in hyphae of the ΔMocdc25 mutants was significantly reduced compared to the parent strain Ku80 and the defect of appressorium formation of the mutants could be partially restored by the supplement of exogenous cAMP. Taken together, we conclude that the RasGEF MoCdc25 regulates vegetative growth, conidiation, appressorium formation and pathogenicity via MAPK and cAMP response pathways in M. oryzae.

Puerarin improves busulfan-induced disruption of spermatogenesis by inhibiting MAPK pathways

Male infertility is a global concern, with a noticeable increase in the decline of spermatogenesis and sperm quality. However, there are limited clinically effective treatments available. This study aimed to investigate the potential effectiveness of puerarin in treating male infertility, which leads to gonadal changes. The results obtained from various analyses such as CASA, immunofluorescence, DIFF-Quick, hematoxylin and eosin (H&E), and periodic acid-Schiff (PAS) staining demonstrated that puerarin supplementation significantly alleviated the busulfan-induced reduction in spermatogenesis and sperm quality in both young and adult mice. Furthermore, puerarin exhibited a marked improvement in the damage caused by busulfan to the architecture of seminiferous tubules, causal epididymis, blood-testicular barrier (BTB), as well as spermatogonia and Sertoli cells. Similarly, puerarin significantly reduced the levels of total antioxidant capacity (T-AOC), malondialdehyde (MDA), and caspase-3 in the testes of busulfan-induced mice, as determined by microplate reader analysis. Additionally, RNA-seq data, RT-qPCR, and western blotting revealed that puerarin restored the abnormal gene expressions induced by busulfan to nearly healthy levels. Notably, puerarin significantly reversed the impact of busulfan on the expression of marker genes involved in spermatogenesis and oxidative stress. Moreover, puerarin suppressed the phosphorylation of p38, ERK1/2, and JNK in the testes, as observed through testicular analysis. Consequently, this study concludes that puerarin may serve as a potential alternative for treating busulfan-induced damage to male fertility by inactivating the testicular MAPK pathways. These findings may pave the way for the use of puerarin in addressing chemotherapy- or other factors-induced male infertility in humans.

Lobetyolin, a Q-marker isolated from Radix Platycodi, exerts protective effects on cisplatin-induced cytotoxicity in HEK293 cells

This study investigated the protective effect of lobetyolin (LBT), a Q-marker isolated from the roots of Platycodon grandiflorum (Radix Platycodi), against cisplatin-induced cytotoxicity in human embryonic kidney (HEK293) cells. Results showed that LBT at 20 μM significantly prevented cisplatin-induced cytotoxicity by improving the viability of HEK293 cells, decreasing levels of MDA, and decreasing GSH content triggered by cisplatin. It also suppressed reactive oxygen species (ROS) levels. Molecular docking analysis revealed a strong binding affinity between LBT and the NF-κB protein, with a docking fraction of - 6.5 kcal/mol. These results provide compelling evidence suggesting a potential link between the visualization analysis of LBT and its protective mechanism, specifically implicating the NF-κB signaling pathway. LBT also reduced the expression level of tumor necrosis factor-alpha (TNF-α), phosphorylation NF-κB and IκBα in HEK293 cells which were increased by cisplatin exposure, leading to inhibition of inflammation. Furthermore, western blotting showed that LBT antagonized the up-regulation of Bax, cleaved caspase 3, 8, and 9 expression and inhibited the MAPK signaling pathway by down-regulating phosphorylation JNK, ERK, and p38, partially ameliorating cisplatin-induced cytotoxicity in HEK293 cells. Therefore, these results indicate that LBT has potentially protected renal function by inhibiting inflammation and apoptosis.

Copine 7 promotes colorectal cancer proliferation through PKM2 interaction and MAPK signaling pathway

Introduction

Colorectal cancer (CRC) is currently the third most common cancer in the world, and its prevalence and mortality rate continue to increase.

Methods

Based on an analysis of The Cancer Genome Atlas database, Tumor Immune Estimation Resource and Gene Expression Profiling Interactive Analysis, we explored the expression of CPNE7 in tumors. Immunohistochemistry and quantitative polymerase chain reaction analysis the expression of CPNE7 in colorectal cancer. Our study explored how CPNE7 promotes CRC cell proliferation and migration in vitro and in vivo. Transcriptome sequencing and Co-IP assay explored the underlying mechinaism of CPNE7 founction.

Results

We found the CPNE7 was overexpressed in CRC by database and IHC. CPNE7 promoted CRC cells proliferstion and migration in vitro and in vivo. Comparing and analyzing transcriptome sequencing between exogenous up-/downregulated CPNE7 CRC cells and the controls, we found that CPNE7 activates mitogen-activated protein kinase (MAPK) signaling pathway stimulating cancer cell proliferation. Coimmunoprecipitation experiments revealed an interaction between CPNE7 and pyruvate kinase muscle protein (PKM2). We also found the activity of MAPK signaling is regulated by exogenous CPNE7 expression.

Discussion

These results imply that CPNE7 may promote the progression of CRC by interacting with PKM2 and initiating the MAPK signaling pathway.

Norbergenin prevents LPS-induced inflammatory responses in macrophages through inhibiting NFκB, MAPK and STAT3 activation and blocking metabolic reprogramming

Inflammation is thought to be a key cause of many chronic diseases and cancer. However, current therapeutic agents to control inflammation have limited long-term use potential due to various side-effects. This study aimed to examine the preventive effects of norbergenin, a constituent of traditional anti-inflammatory recipes, on LPS-induced proinflammatory signaling in macrophages and elucidate the underlying mechanisms by integrative metabolomics and shotgun label-free quantitative proteomics platforms. Using high-resolution mass spectrometry, we identified and quantified nearly 3000 proteins across all samples in each dataset. To interpret these datasets, we exploited the differentially expressed proteins and conducted statistical analyses. Accordingly, we found that LPS-induced production of NO, IL1β, TNFα, IL6 and iNOS in macrophages was alleviated by norbergenin via suppressed activation of TLR2 mediated NFκB, MAPKs and STAT3 signaling pathways. In addition, norbergenin was capable of overcoming LPS-triggered metabolic reprogramming in macrophages and restrained the facilitated glycolysis, promoted OXPHOS, and restored the aberrant metabolites within the TCA cycle. This is linked to its modulation of metabolic enzymes to support its anti-inflammatory activity. Thus, our results uncover that norbergenin regulates inflammatory signaling cascades and metabolic reprogramming in LPS stimulated macrophages to exert its anti-inflammatory potential.

Mechanisms Underlying the Suppression of IL-1β Expression by Magnesium Hydroxide Nanoparticles

In recent years, magnesium hydroxide has been widely studied due to its bioactivity and biocompatibility. The bactericidal effects of magnesium hydroxide nanoparticles on oral bacteria have also been reported. Therefore, in this study, we investigated the biological effects of magnesium hydroxide nanoparticles on inflammatory responses induced by periodontopathic bacteria. Macrophage-like cells, namely J774.1 cells, were treated with LPS derived from Aggregatibacter actinomycetemcomitans and two different sizes of magnesium hydroxide nanoparticles (NM80/NM300) to evaluate their effects on the inflammatory response. Statistical analysis was performed using an unresponsive Student's t-test or one-way ANOVA followed by Tukey's post hoc test. NM80 and NM300 inhibited the expression and secretion of IL-1β induced by LPS. Furthermore, IL-1β inhibition by NM80 was dependent on the downregulation of PI3K/Akt-mediated NF-κB activation and the phosphorylation of MAPK molecules such as JNK, ERK1/2, and p38 MAPK. By contrast, only the deactivation of the ERK1/2-mediated signaling cascade is involved in IL-1β suppression by NM300. Although the molecular mechanism involved varied with size, these results suggest that magnesium hydroxide nanoparticles have an anti-inflammatory effect against the etiologic factors of periodontopathic bacteria. These properties of magnesium hydroxide nanoparticles can be applied to dental materials.

Yupingfeng San exhibits anticancer effect in hepatocellular carcinoma cells via the MAPK pathway revealed by HTS2 technology

ETHNOPHARMACOLOGICAL RELEVANCE

Yupingfeng San (YPFS) is a classic rousing prescription in Chinese medicine, with widly clinical application and remarkably curative effect. It consists of three herbs named Astragalus mongholicus Bunge (Huangqi), Atractylodes rubra Dekker (Baizhu) and Saposhnikovia divaricata (Turcz.) Schischk. (Fangfeng), and has a variety of pharmacological activities including immune regulation, antioxidant, anti-tumor, regulation of cytokines, etc. AIM OF THE STUDY: It has been proved that YPFS exerts its anti-tumor effect through enhancing the systemic and local immune responses in tumor patients, moreover, it has the direct tumor-suppressing effect and can reduce the adverse reactions caused by radiotherapy and chemotherapy drugs. Therefore, in this study, we explored the potential anti-HCC mechanism of YPFS based on HTS² technology and systems pharmacology, aiming to provide a scientific basis for the clinical application of YPFS and a new strategy for Chinese medicine research.

MATERIALS AND METHODS

In this study, systems pharmacology plus high throughput sequencing-based high throughput screening (HTS²) technology, and experimental validation were used to investigate the therapeutic mechanisms and the chemical basis of YPFS in HCC treatment. Firstly, the potential therapeutic targets and signaling pathways of YPFS in the treatment of HCC were obtained through systems pharmacology. Subsequently, HTS² technology combined with PPI network analysis were used to reveal potential therapeutic targets. Finally, the anti-HCC effects and underlying mechanisms of YPFS were further verified in vitro in human hepatocellular carcinoma cell lines. Moreover, the possible chemical basis was explored by drug target verification and molecular docking technology.

RESULTS

In total, 183 active ingredients were predicted by YPFS screening and 49 anti-HCC targets were further identified. Most of these targets were enriched into the "MAPK pathway", and the expression of 37 genes was significantly changed after herb treatment. Among them, 5 key targets, including VEGFA, GRB2, JUN, PDGFRB and CDC42, were predicted by protein-protein interaction (PPI) network analysis. According to our results, YPFS inhibited the proliferation, induced the apoptosis and caused cell cycle arrest of HCC cells. In addition, YPFS significantly reduced P38 gene expression. Fangfeng, one of the three herbs in YPFS, significantly down-regulated the expression of more target genes than that of the other two herbs. Lastly, as revealed by molecular docking analysis, 4'-O-glucosyl-5-O-methylvisamminol, an active ingredient identified in Fangfeng, showed a high affinity for P38.

CONCLUSION

Taken together, this study shows that YPFS possesses the activities of anti-proliferation and pro-apoptosis in treating HCC, which are achieved by inhibiting the MAPK signaling pathway. P38 is one of the critical targets of YPFS in treating HCC, which may be directly bound and inhibited by 4'-O-glucosyl-5-O-methylvisamminol, a compound derived from YPFS.

BBOX1-AS1 mediates trophoblast cells dysfunction via regulating hnRNPK/GADD45A axis†

Recurrent pregnancy loss (RPL) is a common pathological problem during pregnancy, and its clinical etiology is complex and unclear. Dysfunction of trophoblasts may cause a series of pregnancy complications, including preeclampsia, fetal growth restriction, and RPL. Recently, lncRNAs have been found to be closely related to the occurrence and regulation of pregnancy-related diseases, but few studies have focused on their role in RPL. In this study, we identified a novel lncRNA BBOX1-AS1 that was significantly upregulated in villous tissues and serum of RPL patients. Functionally, BBOX1-AS1 inhibited proliferation, migration, invasion, tube formation and promoted apoptosis of trophoblast cells. Mechanistically, overexpression of BBOX1-AS1 activated the p38 and JNK MAPK signaling pathways by upregulating GADD45A expression. Further studies indicated that BBOX1-AS1 could increase the stability of GADD45A mRNA by binding hnRNPK and ultimately cause abnormal trophoblast function. Collectively, our study highlights that the BBOX1-AS1/hnRNPK/GADD45A axis plays an important role in trophoblast-induced RPL and that BBOX1-AS1 may serve as a potential target for the diagnosis of RPL.

Neferine alleviates ovalbumin-induced asthma via MAPK signaling pathways in mice

PURPOSE

To investigate the role of neferine in ovalbumin (OVA)-induced asthma, and to reveal the possible mechanism.

METHODS

In OVA-induced asthmatic mice, enzyme-linked-immunosorbent serologic assay was performed to evaluate the level of interleukin (IL)-4, IL-5, IL-13, immunoglobulin E (IgE) in serum and tumor necrosis factor-α (TNF-α), IL-6, IL-1β, and monocyte chemoattractant protein-1 (MCP-1) in bronchoalveolar lavage fluid (BALF). Eosinophil, neutrophil, and lymphocyte counts in BALF were calculated to assess inflammation. The pulmonary function was measured by airway resistance, peak expiratory flow (PEF) and forced expiratory volume/forced vital capacity (FEV_0.4/FVC) ratio, and respiratory rate. Hematoxylin and eosin staining and Masson staining were used to evaluate lung injury. Further, Western blot analysis was conducted to detect phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 of mitogen-activated protein kinase (MAPK) signaling pathways.

RESULTS

Neferine, 20 mg/kg or 40 mg/kg, could significantly decrease the levels of IL-4, IL-5, IL-13, and IgE in OVA-induced serum, and that of TNF-α, IL-6, IL-1β, and MCP-1 in OVA-induced BALF. Moreover, neferine could significantly decline eosinophil, neutrophil, and lymphocyte counts in BALF. Neferine contributed to improve OVA-induced airway resistance, promoted the value of PEF and FEV_0.4/FVC ratio, and recovered the respiratory rate. It also reduced mucus secretion, distribution of inflammatory and goblet cells around bronchi, and attenuated collagen deposition in lung tissues. Furthermore, neferine reduced the phosphorylation of p38, JNK, and ERK to inhibit MAPK signaling pathways.

CONCLUSION

Neferine relieves asthma-induced inflammatory reaction, airway resistance, and lung injury by inhibiting MAPK signaling pathways. This could serve neferine as a novel therapeutic candidate for treating asthma.

Nickel oxide nanoparticles exposure as a risk factor for male infertility: "In vitro" effects on porcine pre-pubertal Sertoli cells

Lately, nickel oxide nanoparticles (NiO NPs) have been employed in different industrial and biomedical fields. Several studies have reported that NiO NPs may affect the development of reproductive organs inducing oxidative stress and, resulting in male infertility. We investigated the in vitro effects of NiO NPs on porcine pre-pubertal Sertoli cells (SCs) which undergone acute (24 h) and chronic (from 1 up to 3 weeks) exposure at two subtoxic doses of NiO NPs of 1 μg/ml and 5 μg/ml. After NiO NPs exposure we performed the following analysis: (a) SCs morphological analysis (Light Microscopy); (b) ROS production and oxidative DNA damage, gene expression of antioxidant enzymes (c) SCs functionality (AMH, inhibin B Real-time PCR analysis and ELISA test); (d) apoptosis (WB analysis); (e) pro-inflammatory cytokines (Real-time PCR analysis), and (f) MAPK kinase signaling pathway (WB analysis). We found that the SCs exposed to both subtoxic doses of NiO NPs didn't sustain substantial morphological changes. NiO NPs exposure, at each concentration, reported a marked increase of intracellular ROS at the third week of treatment and DNA damage at all exposure times. We demonstrated, un up-regulation of SOD and HO-1 gene expression, at both concentrations tested. The both subtoxic doses of NiO NPs detected a down-regulation of AMH and inhibin B gene expression and secreted proteins. Only the 5 μg/ml dose induced the activation of caspase-3 at the third week. At the two subtoxic doses of NiO NPs a clear pro-inflammatory response was resulted in an up-regulation of TNF-α and IL-6 in terms of mRNA. Finally, an increased phosphorylation ratio of p-ERK1/2, p-38 and p-AKT was observed up to the third week, at both concentrations. Our results show the negative impact of subtoxic doses NiO NPs chronic exposure on porcine SCs functionality and viability.

Fabrication of Low-Molecular-Weight Hyaluronic Acid-Carboxymethyl Cellulose Hybrid to Promote Bone Growth in Guided Bone Regeneration Surgery: An Animal Study

Guided bone regeneration surgery is an important dental operation used to regenerate enough bone to successfully heal dental implants. When this technique is performed on maxilla sinuses, hyaluronic acid (HLA) can be used as an auxiliary material to improve the graft material handling properties. Recent studies have indicated that low-molecular hyaluronic acid (L-HLA) provides a better regeneration ability than high-molecular-weight (H-HLA) analogues. The aim of this study was to fabricate an L-HLA-carboxymethyl cellulose (CMC) hybrid to promote bone regeneration while maintaining viscosity. The proliferation effect of fabricated L-HLA was tested using dental pulp stem cells (DPSCs). The mitogen-activated protein kinase (MAPK) pathway was examined using cells cultured with L-HLA combined with extracellular-signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 inhibitors. The bone growth promotion of fabricated L-HLA/CMC hybrids was tested using an animal model. Micro-computer tomography (Micro-CT) and histological images were evaluated quantitatively to compare the differences in the osteogenesis between the H-HLA and L-HLA. Our results show that the fabricated L-HLA can bind to CD44 on the DPSC cell membranes and affect MAPK pathways, resulting in a prompt proliferation rate increase. Micro CT images show that new bone formation in rabbit calvaria defects treated with L-HLA/CMC was almost two times higher than in defects filled with H-HLA/CMC (p < 0.05) at 4 weeks, a trend that remained at 8 weeks and was confirmed by HE-stained images. According to these findings, it is reasonable to conclude that L-HLA provides better bone healing than H-HLA, and that the L-HLA/CMC fabricated in this study is a potential candidate for improving bone healing efficiency when a guided bone regeneration surgery was performed.

Targeting the EGFR-ERK axis using the compatible solute ectoine to stabilize CFTR mutant F508del

Mutations in the CFTR gene lead to cystic fibrosis, a genetic disease associated with chronic infection and inflammation and ultimately respiratory failure. The most common CF-causing mutation is F508del and CFTR modulators (correctors and potentiators) are being developed to rescue its trafficking and activity defects. However, there are currently no modulators that stabilize the rescued membrane F508del-CFTR which is endocytosed and quickly degraded resulting in a shorter half-life than wild-type (WT). We previously reported that the extracellular signal-regulated kinase (ERK) MAPK pathway is involved in CFTR degradation upon cigarette smoke exposure. Interestingly, we found that ERK phosphorylation was increased in CF human bronchial epithelial (HBE) cells (CF-HBE41o- and primary CF-HBE) compared to non-CF controls, and this was likely due to signaling by the epidermal growth factor receptor (EGFR). EGFR can be activated by several ligands, and we provide evidence that amphiregulin (AREG) is important for activating this signaling axis in CF. The natural osmolyte ectoine stabilizes membrane macromolecules. We show that ectoine decreases ERK phosphorylation, increases the half-life of rescued CFTR, and increases CFTR-mediated chloride transport in combination with the CFTR corrector VX-661. Additionally, ectoine reduces production of AREG and interleukin-8 by CF primary bronchial epithelial cells. In conclusion, EGFR-ERK signaling negatively regulates CFTR and is hyperactive in CF, and targeting this axis with ectoine may prove beneficial for CF patients.

Cepharanthine Suppresses Herpes Simplex Virus Type 1 Replication Through the Downregulation of the PI3K/Akt and p38 MAPK Signaling Pathways

Cepharanthine (CEP) is a naturally occurring isoquinoline alkaloid extracted from Stephania cepharantha Hayata. Although its underlying molecular mechanism is not fully understood, this compound is reported as a promising antiviral drug. In the present study, we explore the anti-HSV-1 effects and the underlying molecular mechanisms of CEP in vitro. Our results show that CEP could significantly inhibit the formation of plaque and the expression of viral proteins and exhibit a general suppression of replication-associated genes. Whereas HSV-1 infection increases the expressions of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and p38 mitogen-activated protein kinase (p38 MAPK) in host cells, CEP was effective indirectly inhibiting phosphorylation levels of the targets in PI3K/Akt and p38 MAPK signaling pathways. Moreover, CEP markedly decreased G₀/G₁ phase and increased G₂/M phase cells and decreased the expression of cyclin-dependent kinase1 (CDK1) and cyclinB1 in a dose-dependent manner. Additionally, CEP increased apoptosis in infected cells, reduced B cell lymphoma-2 (Bcl-2) protein levels, and increased the protein levels of Bcl-associated X protein (Bax), cleaved-caspase3, and nuclear IκB kinaseα (IκBα). Collectively, CEP could arrest the cell cycle in the G₂/M phase and induce apoptosis in infected cells by inhibiting the PI3K/Akt and p38 MAPK signaling pathways, hence further reducing HSV-1 infection and subsequent reproduction.

Riboflavin as a Mucosal Adjuvant for Nasal Influenza Vaccine

Intranasal immunization with whole inactivated virus (WIV) is an important strategy used for influenza prevention and control. However, a powerful mucosal adjuvant is required to improve nasal vaccine efficacy. Riboflavin, as a food additive with the advantages of being safe and low-cost, widely exists in living organisms. In this paper, the mucosal adjuvant function of riboflavin was studied. After intranasal immunization with H1N1 WIV plus riboflavin in mice, we found that the mucosal immunity based on the secretory IgA (sIgA) levels in the nasal cavity, trachea, and lung were strongly enhanced compared with H1N1 WIV alone. Meanwhile, the IgG, IgG1, and IgG2a levels in serum also showed a high upregulation and a decreased ratio of IgG1/IgG2a, which implied a bias in the cellular immune response. Moreover, riboflavin strongly improved the protection level of H1N1 inactivated vaccine from a lethal influenza challenge. Furthermore, riboflavin was found to possess the capacity to induce dendritic cell (DC) phenotypic (MHCII, CD40, CD80, and CD86) and functional maturation, including cytokine secretion (TNF-α, IL-1β, IL-12p70, and IL-10) and the proliferation of allogeneic T cells. Lastly, we found that the DC maturation induced by riboflavin was dependent on the activation of the mitogen-activated protein kinase (MAPK) signaling pathway, which plays an important role in immune regulation. Therefore, riboflavin is expected to be developed as an alternative mucosal adjuvant for influenza nasal vaccine application.

LncRNA LINC01088 inhibits the function of trophoblast cells, activates the MAPK-signaling pathway and associates with recurrent pregnancy loss

Long noncoding RNAs (lncRNAs) have been reported to be involved in various cellular processes and to participate in a variety of human diseases. Recently, increasing studies have reported that lncRNAs are related to many reproductive diseases, such as pathogenesis of recurrent pregnancy loss (RPL), preeclampsia (PE) and gestational diabetes mellitus (GDM). In this study, we aimed to investigate the effect of LINC01088 in trophoblast cells and its potential role in pathogenesis of RPL. LINC01088 was found to be upregulated in first-trimester chorionic villi tissues from RPL patients. Increased LINC01088 repressed proliferation, migration and invasion of trophoblast cells, and promoted apoptosis of trophoblast cells. Further exploration indicated that LINC01088 decreased the production of nitric oxide (NO) by binding and increasing Arginase-1 and decreasing eNOS protein levels. Importantly, JNK and p38 MAPK-signaling pathways were active after overexpression of LINC01088. In conclusion, our studies demonstrated that LINC01088 plays an important role in the pathogenesis of RPL, and is a potential therapeutic target for the treatment of RPL.

Bergenin Monohydrate Attenuates Inflammatory Response via MAPK and NF-κB Pathways Against Klebsiella pneumonia Infection

Background:Klebsiella pneumonia has emerged as a critical pathogen causing severe clinical problems, such as pneumonia and sepsis. Meanwhile, intensified drug resistance induced by antibiotic therapy necessitates discovering novel and active molecules from Traditional Chinese Medicine (TCM) for treatment.

Methods and results: In this study, the isolated Bergenin monohydrate showed an anti-inflammatory effect in Klebsiella-infected mice. We initially investigated the anti-inflammatory effects and cytoprotection against oxidative stress in vitro and in vivo. Interestingly, a specific dose of Bm can effectively ameliorate lung injury and suppress the expression of inflammatory cytokines such as TNF-α, IL-6, IL-1β and PEG2. Moreover, Bm was also shown to reduced the levels of MPO, MDA and increased SOD and GSH activities. Moreover, we assessed the intracellular signaling molecules including p38, ERK, JNK, IκB, NF-κB-p65 by western blotting and verified through MAPK and NF-κB pathways inhibition experiments. These results reveal that Bm executed its effects via the classical MAPK signaling pathway and NF-κB pathway.

Conclusion: Given its underlying anti-inflammatory effect, Bm may be used as a promising therapeutic against Klebsiella-induced infection, thus providing a benefit for the future clinical therapy of pneumonia and medicine design.

A systematic analysis of signaling reactivation and drug resistance

Increasing evidence suggests that the reactivation of initially inhibited signaling pathways causes drug resistance. Here, we analyze how network topologies affect signaling responses to drug treatment. Network-dependent drug resistance is commonly attributed to negative and positive feedback loops. However, feedback loops by themselves cannot completely reactivate steady-state signaling. Newly synthesized negative feedback regulators can induce a transient overshoot but cannot fully restore output signaling. Complete signaling reactivation can only occur when at least two routes, an activating and inhibitory, connect an inhibited upstream protein to a downstream output. Irrespective of the network topology, drug-induced overexpression or increase in target dimerization can restore or even paradoxically increase downstream pathway activity. Kinase dimerization cooperates with inhibitor-mediated alleviation of negative feedback. Our findings inform drug development by considering network context and optimizing the design drug combinations. As an example, we predict and experimentally confirm specific combinations of RAF inhibitors that block mutant NRAS signaling.

Kholodenko et al. uncover signaling network circuitries and molecular mechanisms necessary and sufficient for complete reactivation or overshoot of steady-state signaling after kinase inhibitor treatment. The two means to revive signaling output fully are through network topology or reactivation of the kinase activity of the primary drug target. Blocking RAF dimer activity by a combination of type I½ and type II RAF inhibitors efficiently blocks mutant NRAS-driven ERK signaling.

MAPK/iNOS pathway is involved in swine kidney necrosis caused by cadmium exposure

Cadmium (Cd) pollution in the environment could cause toxic damage to animals and humans. MAPK pathways could regulate their downstream inflammatory factors, and plays a crucial role in necrosis. Since the swine kidney tissue is an important accumulation site of Cd and target organ of its toxic damage, but the damage form of Cd to swine kidney and the role of MAPK pathways in it are still not clear, we selected six week old weaned piglets as the research object, and fed a diet supplemented CdCl₂ (20 mg/kg) to establish the model of liver injury induced by Cd. The expressions and phosphorylation of MAPK pathways (ERK, JNK, p38), expression levels of inflammatory factors (TNF-α, NF-κB, iNOS, COX-2 and PTGE) and necrosis related genes (MLKL, RIPK1, RIPK3 and FADD) and heat shock proteins (HSPs) were detected by RT-PCR and Western blot. H.E. staining was used to determine the damage of kidney caused by Cd exposure. The results showed that Cd exposure could activate p38 and JNK pathway phosphorylation, rather than ERK 1/2, up regulated the expressions of inflammatory factors, finally induced programmed necrosis (increasing the expressions of MLKL, RIPK1, RIPK3 and FADD) in swine kidney. Our study elucidated the mechanism of Cd-damage to swine kidney and the relationship among MAPK pathways, inflammatory factors and programmed necrosis in swine.

Poncirin suppresses lipopolysaccharide (LPS)-induced microglial inflammation and ameliorates brain ischemic injury in experimental stroke in mice

Background

Based on accumulating evidence, excessive activation of microglia-mediated inflammatory responses plays an essential role in ischemic stroke. Poncirin (Pon) exerts anti-hyperalgesic, anti-osteoporotic and anti-tumor effects on various diseases. However, the roles of Pon in microglial activation and the underlying mechanism have not been elucidated. This study aimed to explore whether Pon inhibits lipopolysaccharide (LPS)-induced microglial neuroinflammation and protects against brain ischemic injury in experimental stroke in mice.

Methods

Primary microglia cells were prepared from the cerebral cortices of 1- to 2-day-old C57BL/6J mice. Murine BV2 cells and primary microglia were stimulated with LPS and the effects of a non-cytotoxic concentration of Pon on LPS-stimulated pro-inflammatory factors were measured using real-time PCR and enzyme-linked immunosorbent assays (ELISAs). Western blot analyses were used for mechanistic studies. In an in vivo study, 8-week-old male C57BL/6J mice were subjected to focal cerebral ischemia through middle cerebral artery occlusion (MCAO). Pon (30 mg/kg, i.p.) or the same volume of saline was administered after the MCAO model was established, and the infarct volume was evaluated using 2,3,5-triphenyltetrazolium chloride (TTC) staining. We also evaluated animal behaviours, the expression of pro-inflammatory cytokines and microglial activation in the ischemic hemisphere.

Results

Pon prevented the release of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-1β, IL-6 and tumor necrosis factor-alpha (TNF-α) in both BV2 cells and primary microglia stimulated with LPS. The inhibitory effects of Pon were associated with the regulation of the ERK1/2, JNK and nuclear factor kappa B (NF-κB) signaling pathways. In mice that underwent MCAO, Pon administration decreased the lesion size and improved neurological deficits. Furthermore, Pon attenuated the production of inflammatory cytokines mainly by restraining microglial activation after ischemic stroke.

Conclusions

Based on the findings from the present study, Pon provides neuroprotection through its anti-inflammatory effects on microglia and it may be a useful treatment for ischemic stroke.

Nanocurcumin as a novel stimulator of megakaryopoiesis that ameliorates chemotherapy-induced thrombocytopenia in mice

AIMS

Platelet production improvement can resolve concerns about the limitations of external platelet supply and platelet transfusion in thrombocytopenia patients. To this end, scientists encourage to induce the generation of megakaryocyte and platelet. Curcumin is a safe ingredient of turmeric that affects various cellular pathways. The effect of this component on platelet production has not been yet reported.

MAIN METHODS

Our in vitro experiments include the investigation of the effects of nanocurcumin on megakaryocytes production from K562 cells and hematopoietic stem cells via megakaryocyte markers expression, DNA content, ROS, and morphologic analysis, and CFC assay. The regulatory functions of MAPKs pathways were also determined. In the in vivo study tissue distribution of nanocurcumin was determined and two treatment schedules were used to evaluate the capability of nanocurcumin to prevent the occurrence of Busulfan-induced thrombocytopenia in the mouse model.

KEY FINDING

In vitro evidences demonstrated that nanocurcumin can induce MK production from K562 cells and hematopoietic stem cells. Inhibition of ERK1/2 and JNK pathways arrested this activity. In vivo experiments showed the uptake of nanocurcumin by tissues in mice. Administration of nanocurcumin could preserve bone marrow integrity and increase of the number of circulating platelets in the Busulfan-treated mice models.

SIGNIFICANCE

Our results have demonstrated that nanocurcumin administration can be useful for the improvement of megakaryocytes and platelet generation in vitro. This component may be exerting these beneficial effects on megakaryopoiesis by modulating ERK1/2 and JNK pathways. As well as nanocurcumin has the potential to prevent thrombocytopenia in chemotherapy threated mice.

Clock-Bmal1 mediates MMP9 induction in acrolein-promoted atherosclerosis associated with gut microbiota regulation

Circadian rhythm is believed to play important roles in atherosclerosis. The gut microbiota is found to be closely related to atherogenesis, and shows compositional and functional circadian oscillation. However, it's still unclarified whether circadian clock and intestinal microbiota are involved in the progression of atherosclerosis induced by environmental pollutant acrolein. Herein, patients with atherosclerosis showed higher MMP9, a promising biomarker for atherosclerosis, and lower Bmal1 and Clock expression in the plasma. Interestingly, acrolein exposure contributed to the increased MMP9, decreased Clock and Bmal1, and activated MAPK pathways in human umbilical vein endothelial cells (HUVECs). We found that knockdown of Clock or Bmal1 lead to upregulation of MMP9 in HUVECs, and that Clock and Bmal1 expression was elevated while MAPK pathways were blocked. Atherosclerotic apolipoproteinE-deficient mice consumed a high-fat diet were used and treated with acrolein (3 mg/kg/day) in the drinking water for 12 weeks. Upregulation of MMP9, and downregulation of Clock and Bmal1 were also observed in plasma of the mice. Besides, acrolein feeding altered gut microbiota composition at a phylum level especially for an increased Firmicutes and a decreased Bacteroidetes. Additionally, gut microbiota showed correlation with atherosclerotic plaque, MMP9 and Bmal1 levels. Therefore, our findings indicated that acrolein increased the expression of MMP9 through MAPK regulating circadian clock, which was associated with gut microbiota regulation in atherosclerosis. Circadian rhythms and gut microbiota might be promising targets in the prevention of cardiovascular disease caused by environmental pollutants.

Nano-selenium attenuates nickel-induced testosterone synthesis disturbance through inhibition of MAPK pathways in Sprague-Dawley rats

The aim of this study was to investigate the protective effects of Nano-Se against Ni-induced testosterone synthesis disorder in rats and determine the underlying protective mechanism. Sprague-Dawley rats were co-treated with Ni (5.0 mg/kg, i.p.) and Nano-Se (0.5, 1.0, and 2.0 mg/kg, oral gavage) for 14 days after which various endpoints were evaluated. The Ni-induced abnormal pathological changes and elevated 8-OHdG levels in the testes were attenuated by Nano-Se administration. Importantly, decreased serum testosterone levels in the Ni-treated rats were significantly restored by Nano-Se treatment, particularly at 1.0 and 2.0 mg/kg. Furthermore, the mRNA and protein levels of testosterone synthetase were increased by Nano-Se compared to the Ni group, whereas phosphorylated protein expression levels of mitogen-activated protein kinase (MAPK) pathways were suppressed by Nano-Se administration in the Ni-treated rats. Overall, the results suggest that Nano-Se may ameliorate the Ni-induced testosterone synthesis disturbance via the inhibition of ERK1/2, p38, and JNK MAPK pathways.

iRoot BP Plus promotes osteo/odontogenic differentiation of bone marrow mesenchymal stem cells via MAPK pathways and autophagy

BACKGROUND

iRoot BP Plus is a novel bioceramic endodontic material. Recently, it has been considered as an alternative to MTA which is the most popular scaffold cover during regenerative endodontic therapy. This study aimed to evaluate the effects of iRoot BP Plus on the osteo/odontogenic capacity of bone marrow mesenchymal stem cells (BMMSCs), including the underlying mechanisms.

METHODS

BMMSCs were collected by a whole marrow method and treated with iRoot BP Plus-conditioned medium (BP-CM). The proliferation ability was evaluated by cell counting kit 8 and flow cytometry. Complete medium was used as a blank control, and 2 mg/ml MTA-conditioned medium was served as a positive control. Alkaline phosphatase (ALP) activity assay, ALP staining, western blot, real-time RT-PCR, Alizarin Red S staining, and immunofluorescence staining were performed to explore the osteo/odontogenic potential and the involvement of MAPK pathways. Besides, autophagy was investigated by western blot, immunofluorescence staining, and transmission electron microscopy.

RESULTS

[Mechanism of Danzhi Jiangtang Capsules on improving liver injury in hyperlipidemia rats based on MAPK pathway]

This study aimed to investigate the protective effect and preliminary mechanism of Danzhi Jiangtang Capsules( DJC) on liver of hyperlipidemic rats. The hyperlipidemia models were successfully made by high-fat diet for 12 weeks in male SD rats,and then divided into model control group and DJC treatment groups( 500 and 1 000 mg·kg~(-1)·d-1) via gavage administration for additional 8 weeks.The levels of serum lipid and liver metabolism indices were detected; HE and oil red O staining were used to observe the pathological changes of liver. Expression levels of extracellular regulated protein kinase 1/2( ERK1/2),c-Jun N-terminal kinase( JNK),and p38 mitogen-activated protein kinase( p38 MAPK) were detected by real-time polymerase chain reaction( RT-PCR). Expression of MCP-1,phosphorylated ERK( p-ERK),phosphorylated JNK( p-JNK),and phosphorylated p38 MAPK( p-p38) were analyzed by immunohistochemistry and Western blot. The results showed that DJC decreased body weight and serum levels of total cholesterol( TC),triglyceride( TG),alanine aminotransferase( ALT),aspartate aminotransferase( AST),increased serum high-density lipoprotein cholesterol( HDL-C) level,ameliorate injury and lipid deposition in the liver induced by the high-fat diet,decreased mRNA expression of ERK1/2,JNK and p-38 MAPK as well as protein expression of p-ERK,p-JNK,p-p38,and MCP-1,somewhat showing a dose-dependent effect. Therefore,DJC has an obvious protective effect on liver of hyperlipidemic rats with certain dose-dependent effect,and the mechanism may be related with inhibiting MAPK pathways and inflammation.

Active compound chrysophanol of Cassia tora seeds suppresses heat-induced lipogenesis via inactivation of JNK/p38 MAPK signaling in human sebocytes

Background

Heat induced by infrared (IR) radiation from sun exposure increases skin temperature and can lead to thermal and photo-aging. However, little is known about the relationship between heat induced by IR radiation and lipid biosynthesis in human sebocytes. This study investigated the expression of factors involved in lipid biosynthesis in human sebocytes exposed to heat. The effect of Cassia tora extract and chrysophanol, which is widely used as anti-inflammatory agent, on the heat shock effect in sebocytes was then examined.

Methods

For the treatment, cells were maintained in culture medium without FBS (i.e., serum starved) for 6 h and then moved for 30 min to incubators at 37 °C (control), 41 °C, or 44 °C (heat shock). Culture media were replaced with fresh media without FBS. To investigate expression of gene and signaling pathway, we performed western blotting. Lipid levels were assessed by Nile red staining. The cytokine levels were measured by cytokine array and ELISA kit.

Results

We found that peroxisome proliferator-activated receptor (PPAR)γ and fatty acid synthase (FAS) were upregulated and the c-Jun N-terminal kinase (JNK)/p38 signaling pathways were activated in human sebocytes following heat exposure. Treatment with Cassia tora seed extract and chrysophanol suppressed this up-regulation of PPARγ and FAS and also suppressed the increase in IL-1β levels.

Conclusion

These findings provide evidence that IR radiation can stimulate sebum production; Cassia tora seed extract and chrysophanol can reverse lipid stimulated inflammatory mediation, and may therefore be useful for treating skin disorders such as acne vulgaris.

Filamentation Regulatory Pathways Control Adhesion-Dependent Surface Responses in Yeast

Signaling pathways can regulate biological responses by the transcriptional regulation of target genes. In yeast, multiple signaling pathways control filamentous growth, a morphogenetic response that occurs in many species including fungal pathogens. Here, we examine the role of signaling pathways that control filamentous growth in regulating adhesion-dependent surface responses, including mat formation and colony patterning. Expression profiling and mutant phenotype analysis showed that the major pathways that regulate filamentous growth [filamentous growth MAPK (fMAPK), RAS, retrograde (RTG), RIM101, RPD3, ELP, SNF1, and PHO85] also regulated mat formation and colony patterning. The chromatin remodeling complex, SAGA, also regulated these responses. We also show that the RAS and RTG pathways coregulated a common set of target genes, and that SAGA regulated target genes known to be controlled by the fMAPK, RAS, and RTG pathways. Analysis of surface growth-specific targets identified genes that respond to low oxygen, high temperature, and desiccation stresses. We also explore the question of why cells make adhesive contacts in colonies. Cell adhesion contacts mediated by the coregulated target and adhesion molecule, Flo11p, deterred entry into colonies by macroscopic predators and impacted colony temperature regulation. The identification of new regulators (e.g., SAGA), and targets of surface growth in yeast may provide insights into fungal pathogenesis in settings where surface growth and adhesion contributes to virulence.

Cyclic tensile stress promotes osteogenic differentiation of adipose stem cells via ERK and p38 pathways

The present study aimed to elucidate whether extracellular signal-regulated kinases 1/2 (ERK1/2) and p38 mitogen-activated protein kinases pathways participate in the transduction of mechanical stretch exerted on adipose stem cells (ASCs) into intracellular osteogenic signals, and if so whether both pathways have time-dependent feature. Rat ASCs were cultured in osteogenic medium for 72 h and assigned into three sets, namely ERK1/2 inhibitor treated set, p38 inhibitor treated set, and the control set. After inhibitor treatment, all cells were subjected to cyclic stretch(2000 με, 1 Hz) on a four-point bending mechanical loading device. Protein and mRNA samples were acquired at six time points: 0, 15 min, 30 min, 1 h, 2 h and 6 h. Western blot showed phosphorylation level of ERK1/2 was elevated by cyclic tensile stress at all time points, while p38 at 15 min, 30 min and 1 h, and the elevation can be completely blocked by corresponding inhibitors. The treatment by ERK1/2 inhibitor was shown to antagonize the up-regulation of osteogenic genes bone morphogenetic protein 2 (BMP-2) and runt-related transcription factor 2 (Runx2) by mechanical stretch at 15 min and 6 h, whereas p38 inhibitor took effect at 15 min only. The results suggested both ERK and p38 could be positive mediators of stretch-induced osteogenic differentiation of ASCs, and ERK stimulate the stretch-induced osteogenic differentiation at both early and late stages while p38 responds to mechanical stretch in a more rapid fashion.

2,2',4,4'-tetrabromodiphenyl ether induces germ cell apoptosis through oxidative stress by a MAPK-mediated p53-independent pathway

2,2',4,4'-Tetrabromodiphenyl ether (BDE-47), a representative congener of polybrominated diphenyl ethers in the environment, is known to have reproductive toxicity. However, the underlying mechanisms remain to be clarified, especially in in vivo systems. In the present study, we employed Caenorhabditis elegans to study the effects of BDE-47 on reproduction. Our results showed that BDE-47 impaired worm fecundity and induced germ cell apoptosis. To elucidate the mechanisms, DNA damage and oxidative stress induction were investigated by determining the numbers of foci formation in transgenic worms expressing HUS-1::GFP and the levels of reactive oxygen species, respectively. We found that BDE-47 induced oxidative stress but not DNA damage, and treatment with the antioxidant, N-acetyl-L-cysteine, completely abrogated BDE-47-induced germ cell apoptosis. In addition, the apoptosis was blocked in mutants carrying mek-1, sek-1 or abl-1 loss-of-function alleles, but not in the p53/cep-1 deficient worms, suggesting that the mitogen-activated protein kinase (MAPK) signaling cascade was essential for BDE-47-induced germ cell apoptosis and p53/cep-1 was not required. Moreover, the apoptosis in the strains deficient for DNA damage response was not suppressed under BDE-47 treatment. Overall, we demonstrated that BDE-47 could induce oxidative stress and subsequent germ cell apoptosis in Caenorhabditis elegans through a MAPK-mediated p53-independent pathway.

Immunotoxicity of titanium dioxide nanoparticles via simultaneous induction of apoptosis and multiple toll-like receptors signaling through ROS-dependent SAPK/JNK and p38 MAPK activation

BACKGROUND

Titanium dioxide nanoparticles (TiO2 NPs) represent a scientific breakthrough in the areas of biological and medicinal applications. Interaction of TiO2 NPs with components of innate immune system remains elusive.

AIM

This study explored in vitro immunotoxicity of murine macrophage RAW 264.7 to TiO2 NPs (20 nm, negative charge) and its underlying molecular mechanism by way of immunoredox profiling.

MATERIALS AND METHODS

In this study, chemically synthesized BSA-functionalized TiO2 NPs (20 nm, negative charge) were characterized and immunotoxicity was investigated on RAW 264.7 cells.

RESULTS

We found that reactive oxygen species levels significantly increased with increasing nitric oxide production, whereas depleting endogenous antioxidant super oxide dismutase as well as nuclear factor erythroid 2-related factor 2 (Nrf2) protein levels. Furthermore, NPs exposure increased the expression of apoptotic factors such as BAX, BIM, and PUMA with disruption of mitochondrial membrane potential (Δψm) that lead to decrease in immunocytes. Molecular immune profiling revealed the activation of multiple toll-like receptors (TLRs) 4/9/12/13 simultaneously with the phosphorylation of p-p38MAPK and p-SAPK/c-Jun N-terminal kinase (JNK) compared to untreated control.

CONCLUSION

Collectively, this study shows that the molecular nature of TiO2 SA20(-) NP-induced immunotoxicity in RAW 264.7 macrophage is simultaneous induction of immunocyte apoptosis and multiple TLRs signaling through oxidative stress-dependent SAPK/JNK and p38 mitogen-associated protein kinase activation. This is the first study to address newer molecular mechanism of TiO2 SA20(-) NP-induced immunotoxicity.

Taurine Have Neuroprotective Activity against Oxidative Damage-Induced HT22 Cell Death through Heme Oxygenase-1 Pathway

Glutamate-induced oxidative neurotoxicity plays a part role in neuronal degeneration on the disorders of central nervous system (CNS). The expression of heme oxygenase (HO)-1 mediated by Inducible nuclear factor-E2-related factor 2 (Nrf2) functions as an anti-oxidants that is able to play an important role in the pathogenesis of several neuronal disorders. In the present study, taurine showed the inhibitory effect against reactive oxygen species (ROS) induction and protective effects against neurotoxicity induced by glutamate- and H2O2 through induction of HO-1 expression in HT22 cells. Moreover, taurine promoted the Nrf2 nuclear translocation in HT22 cells. We also verified the oxidative stress-mediated cell death of HT22 cells was significantly repressed by taurine, using tin protoporphyrin (SnPP) as an HO activity inhibitor. In addition, we found that treatment of the cells with p38 inhibitor (SB203580) suppressed taurine-induced HO-1 expression and cytoprotection, but inhibitors of c-Jun NH2 terminal kinase (JNK) (SP600125) or extracellular signal regulated kinase (ERK) (PD98059) did not. These results suggest that taurine improves the resistance against oxidative damages induced by glutamate in HT22 cells via the p38/Nrf2-dependent HO-1 expression. Our results demonstrated the potential application of taurine as a therapeutic agent for neurodegenerative diseases.

Inhibitory effect of different Dendrobium species on LPS-induced inflammation in macrophages via suppression of MAPK pathways

Dendrobii Caulis (DC), named 'Shihu' in Chinese, is a precious herb in traditional Chinese medicine. It is widely used to nourish stomach, enhance body fluid production, tonify "Yin" and reduce heat. More than thirty Dendrobium species are used as folk medicine. Some compounds from DC exhibit inhibitory effects on macrophage inflammation. In the present study, we compared the anti-inflammatory effects among eight Dendrobium species. The results provided evidences to support Dendrobium as folk medicine, which exerted its medicinal function partially by its inhibitory effects on inflammation. To investigate the anti-inflammatory effect of Dendrobium species, mouse macrophage cell line RAW264.7 was activated by lipopolysaccharide. The nitric oxide (NO) level was measured using Griess reagent while the pro-inflammatory cytokines were tested by ELISA. The protein expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and mitogen-activated protein kinases (MAPKs) phosphorylation were evaluated by Western blotting analysis. Among the eight Dendrobium species, both water extracts of D. thyrsiflorum B.S.Williams (DTW) and D. chrysotoxum Lindl (DCHW) showed most significant inhibitory effects on NO production in a concentration-dependent manner. DTW also significantly reduced TNF-α, MCP-1, and IL-6 production. Further investigations showed that DTW suppressed iNOS and COX-2 expression as well as ERK and JNK phosphorylation, suggesting that the inhibitory effects of DTW on LPS-induced macrophage inflammation was through the suppression of MAPK pathways. In conclusion, D. thyrsiflorum B.S.Williams was demonstrated to have potential to be used as alternative or adjuvant therapy for inflammation.

Neuroprotective Effects of Radix Scrophulariae on Cerebral Ischemia and Reperfusion Injury via MAPK Pathways

Ischemic stroke is a clinically common cerebrovascular disease whose main risks include necrosis, apoptosis and cerebral infarction, all caused by cerebral ischemia and reperfusion (I/R). Ischemia and reperfusion-induced injury or apoptosis inhibition in human brain tissue may exert an irreplaceable protective effect on ischemic nerves. This process has particular significance for the treatment of stroke patients. However, the development of neuroprotective drugs remains challenging. Radix Scrophulariae, traditionally considered a valuable medicine, has been discovered to have neuroprotective effects. To explore the neuroprotective effects of an aqueous extract of Radix Scrophulariae (RSAE) on cerebral ischemia/reperfusion and their underlying mechanisms, oxygen-glucose deprivation and reperfusion (OGD/R)-induced PC12 cells were used, and a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was established. In vitro results showed that 12.5 μg/mL RSAE markedly improved cell viability; inhibited LDH leakage; increased SOD, GSH-Px and CAT enzyme activity; stabilized the mitochondrial membrane potential; and reduced OGD-induced cell injury and apoptosis. Additionally, in vivo results preliminarily suggested that in MCAO/R model mice, RSAE treatments attenuated infarct volume; reduced brain water content and nitric oxide (NO) and malondialdehyde (MDA) concentrations; inhibited I/R-induced neurological deficits; reduced the levels of lactate dehydrogenase (LDH) leakage release; improved antioxidant capacity by upregulating SOD, GSH-Px and CAT enzyme activity; and reduced neuronal apoptosis, necrosis and loss of neurons. Moreover, it was found that RSAE upregulated the expression of Bcl-2 and downregulated the expression of Bax. In addition, the phosphorylation levels of MAPK signal pathways were elucidated via western blot analysis and immunohistochemical evaluation. In summary, this study investigated the neuroprotective effects and potential mechanisms of RSAE on focal cerebral I/R injury in mice. Radix Scrophulariae has been previously identified as a potential neuroprotective natural plant. Hence, our results may offer insight into discovering new active compounds or drugs for the treatment of ischemic stroke. Many new natural active chemicals in this extract may be discovered by chemical separation and identification and may provide new insights into therapeutic targets in stroke patients.

Extrapolation of significant genes and transcriptional regulatory networks involved in Zea mays in response in UV-B stress

A wide range of plant species growth influenced when they exposed to solar UV-B radiation. Leaves of the plant are highly affected by UV-B radiation lead to the reduction in the growth of the plant. Current work demonstrates the comparative transcriptional changes and visible symptoms occurred in the maize leaf growth zone (GZ). Primary objective of this study was to identify differentially expressed genes (DEGs) responsible for leaf growth and their association in the transcriptional regulatory network under UV-B stress. Whole transcriptomic data was analysed and the quality check was tested for each sample and further genome-wide mapping and DEGs were performed. Gene Ontology (GO) based functional annotation, associated transcriptional networks and molecular pathways were annotated. Reduction in cell production due to UV-B stress causes a decrease in leaf's length and size was observed. Further, the specific role of the DEGs, in UV-B signalling pathways and other molecular functions responsible for leaf cell death was discovered. Results also infer that the major changes occurred in the cell cycle, transcriptional regulation, post-transcriptional modification, phytohormones, flavonoids biosynthesis, and chromatin remodeling. UV-B signalling pathways and the transcriptional regulatory networks infer the different molecular steps along with downstream transcriptional and post-transcriptional control of metabolic enzymes used in long-term memory adoption and attainment resistance to UV-B stress identified. Effects of UV-B radiation on leaf growth was noted in this study. UV-B stress response genes and associated transcriptional regulatory networks were identified, can be used in developing the marker assist UB-B stress tolerant genotypes of the maize.

Oxidative Signaling Response to Cadmium Exposure

Changes in the intracellular thiol-disulfide balance are considered major determinants in the redox status/signaling of the cell. Cellular signaling is very sensitive to both exogenous and intracellular redox status and respond to many exogenous pro-oxidative or oxidative stresses. Redox status has dual effects on upstream signaling systems and downstream transcription factors. Redox signaling pathways use reactive oxygen species (ROS) to transfer signals from different sources to the nucleus to regulate such functions as growth, differentiation, proliferation, and apoptosis. Mitogen-activated protein kinases are activated by numerous cellular stresses and ligand-receptor bindings. An imbalance in the oxidant/antioxidant system, either resulting from excessive ROS/reactive nitrogen species production and/or antioxidant system impairment, leads to oxidative stress. Glutathione (GSH) is known to play a critical role in the cellular defense against unregulated oxidative stress in mammalian cells and involvement of large molecular antioxidants include classical antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). Cadmium (Cd), a potent toxic heavy metal, is a widespread environmental contaminant. It is known to cause renal dysfunction, hepatic toxicity, genotoxicity, and apoptotic effects depending on the dose, route, and duration of exposure. This review examines the signaling pathways and mechanisms of activation of transcription factors by Cd-induced oxidative stress thus representing an important basis for understanding the mechanisms of Cd effect on the cells.

Cigarette smoke induced urocystic epithelial mesenchymal transition via MAPK pathways

Cigarette smoke has been shown to be a major risk factor for bladder cancer. Epithelial-mesenchymal transition (EMT) is a crucial process in cancer development. The role of MAPK pathways in regulating cigarette smoke-triggered urocystic EMT remains to be elucidated. Human normal urothelial cells and BALB/c mice were used as in vitro and in vivo cigarette smoke exposure models. Exposure of human normal urothelial cells to cigarette smoke induced morphological change, enhanced migratory and invasive capacities, reduced epithelial marker expression and increased mesenchymal marker expression, along with the activation of MAPK pathways. Moreover, we revealed that ERK1/2 and p38 inhibitors, but rather JNK inhibitor, effectively attenuated cigarette smoke-induced urocystic EMT. Importantly, the regulatory function of ERK1/2 and p38 pathways in cigarette smoke-triggered urocystic EMT was further confirmed in mice exposed to CS for 12 weeks. These findings could provide new insight into the molecular mechanisms of cigarette smoke-associated bladder cancer development as well as its potential intervention.

Gelidium elegans Extract Ameliorates Type 2 Diabetes via Regulation of MAPK and PI3K/Akt Signaling

Gelidium elegans, a red alga native to the Asia Pacific region, contains biologically active polyphenols. We conducted a molecular biological study of the anti-diabetic effect of Gelidium elegans extract (GEE) in C57BL/KsJ-db/db mice. Mice that had been administered GEE had significantly lower body mass, water consumption, and fasting blood glucose than db/db controls. Moreover, hemoglobin A1c (HbA1c), an indicator of the glycemic status of people with diabetes, was significantly lower in mice that had been administered GEE. We also found that 200 mg/kg/day GEE upregulates the insulin signaling pathway by activating insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K), and increasing the expression of glucose transporter type 4 (GLUT4). In parallel, mitogen-activated protein kinase (MAPK) activity was lower in GEE-treated groups. In summary, these findings indicate that GEE regulates glucose metabolism by activating the insulin signaling pathway and downregulating the MAPK signaling pathway.

A novel multi-CDK inhibitor P1446A-05 restricts melanoma growth and produces synergistic effects in combination with MAPK pathway inhibitors

Nearly 100% of melanomas have a defect in the p16(INK4A):cyclin D-CDK4/6:RB pathway, leading to abnormal cell cycle control and unregulated cellular proliferation. Here, we report that P1446A-05, a novel multi-CDK inhibitor has significant inhibitory activity against cutaneous and uveal melanoma. Mechanistic studies revealed that P1446A-05 inhibits phosphorylation targets of CDK members, and induces cell cycle arrest and apoptosis irrespective of melanoma genotype or phenotype. Additionally, we show preclinical evidence that P1446A-05 can synergize with other small molecule inhibitors previously studied in melanoma. Collectively, these data demonstrate that targeting cell cycle and transcriptional CDKs with a small molecule multi-CDK inhibitor is a viable approach for developing novel anti-melanoma therapeutics.

The therapeutic effects of Longikaurin A, a natural ent-kauranoid, in esophageal squamous cell carcinoma depend on ROS accumulation and JNK/p38 MAPK activation

Effective treatments for esophageal squamous cell carcinoma (ESCC), one of the most common cancers in China, are lacking. Longikaurin A (LK-A), an ent-kauranoid diterpenoid isolated from Isodon ternifolius, has been shown to have potent cytotoxic effects on ESCC cells both in vivo and in vitro, mainly by inducing apoptosis. In this study, LK-A inhibited ESCC cells viability and induced G2/M cell cycle arrest. Moreover, LK-A was also highly effective in a KYSE-30 xenograft nude mouse model. Treatment with Z-VAD(OMe)-FMK partially attenuated LK-A-induced apoptosis. LK-A significantly induced reactive oxygen species (ROS) production in ESCC cells, and LK-A-induced apoptosis was attenuated by the ROS scavenger N-acetyl cysteine (NAC). Furthermore, we found that treatment with LK-A activated both the JNK and p38 MAPK signaling pathways, resulting in increases in ROS levels and apoptosis induction. Taken together, these findings indicate that LK-A exerts novel anti-tumor effects in ESCC cells by activating the JNK and p38 MAPK pathways and inducing increases in ROS production, which suggest that the compound may have potential as a clinical therapeutic agent.

Potential protective effects of alpha-pinene against cytotoxicity caused by aspirin in the IEC-6 cells

Alpha-pinene is a key compound of the essential oils extracted from many species of coniferous trees. It is known for its biological activities. The aim of the present study was to determine the preventive effect of alpha-pinene on aspirin-induced toxicity in vitro, using IEC-6 cells, and to investigate its antioxidant activities. The antioxidant activities were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The cytotoxicity and oxidative stress were detected by cell viability, antioxidant enzyme activity, malondialdehyde (MDA) and GSH production, and the activation of MAPK pathways. The results indicated that alpha-pinene revealed an important antioxidant activity. It was evaluated by DPPH test (EC₅₀=310±10μg/mL) and FRAP test (EC₅₀=238±18.92μg/mL). The co-exposure of alpha-pinene with aspirin on cells significantly increased the survival of cells and the level of GSH, and decreased the levels of MDA and total SOD and the activity of Mn-SOD. In addition, the activation of p38 and JNK was blocked by alpha-pinene. Therefore, these findings suggest that alpha-pinene can protect IEC-6 cells against aspirin-induced oxidative stress.

Oleuropein protects intracerebral hemorrhage-induced disruption of blood-brain barrier through alleviation of oxidative stress

BACKGROUND

Intracerebral haemorrhage (ICH) as a devastating form of stroke has remained a public health threat due to lack of FDA-approved therapy. Oxidative stress originated from blood cell degradation products plays a crucial role in the ICH pathogenesis. In this study we evaluated oleuropein, a potent natural antioxidant from olive, in a well-established rat ICH model from overall symptoms to detailed molecular mechanism.

METHODS

ICH model was established by collagenase injection to the brain of rats, which were randomly divided into groups with vehicle mock treatment, followed by treatment with different doses of oleuropein via daily intraperitoneal injection post-ICH for 3days. The overall neurological deficit, brain edema level and blood-brain barrier (BBB) integrity were then measured in different treatment groups. To understand the protection mechanism of oleuropein in ICH, BBB structural components ZO-1 and occludin, oxidative stress and MAPK signalling pathways were also examined.

RESULTS

Oleuropein treatment showed overall alleviation of ICH-associated neurological deficit and brain edema in a dose dependent manner. Consistently, it could preserve the BBB structure and attenuate oxidative stress as well as ICH-induced MAPK activation in brain tissue.

CONCLUSION

Our study suggests oleuropein could be used as a promising therapeutic agent for ICH.

Methyl Protodioscin Induces Apoptosis in Human Osteosarcoma Cells by Caspase-Dependent and MAPK Signaling Pathways

Methyl protodioscin (MPD), a furostanol saponin derived from the rhizomes of Dioscorea collettii var. hypoglauca (Dioscoreaceae), has been shown to exhibit broad bioactivities such as anti-inflammation and antitumor activities. Here, we explored the molecular mechanisms by which MPD induced apoptosis in MG-63 cells. The data showed that MPD significantly suppressed cell growth (cell viabilities: 22.5 ± 1.9% for 8 μM MPD versus 100 ± 1.4% for control, P < 0.01) and enhanced cell apoptosis. The exposure to MPD resulted in a significant induction of reactive oxygen species, loss of mitochondrial membrane potential, and activation of caspase-9 and caspase-3 (P < 0.01, all cases). Furthermore, treatment with MPD increased the levels of phosphorylated JNK and p38 MAPK and markedly decreased the levels of phosphorylated ERK in MG-63 cells. Co-administration of the JNK-specific antagonist, the p38-specific antagonist, or the caspase antagonist (P < 0.05, all cases) has reversed the apoptotic effects in MPD treatment. We also found that exposure to MPD resulted in a significant reduction in the protein level of anti-apoptotic proteins Bcl-2, survivin, and XIAP (P < 0.05, all cases). In conclusion, our results indicate that MPD induces apoptosis of human osteosarcoma MG-63 cells, at least in part, by caspase-dependent and MAPK signaling pathways.

RACK1 cooperates with NRASQ61K to promote melanoma in vivo

Melanoma is the deadliest skin cancer. RACK1 (Receptor for activated protein kinase C) protein was proposed as a biological marker of melanoma in human and domestic animal species harboring spontaneous melanomas. As a scaffold protein, RACK1 is able to coordinate the interaction of key signaling molecules implicated in both physiological cellular functions and tumorigenesis. A role for RACK1 in rewiring ERK and JNK signaling pathways in melanoma cell lines had been proposed. Here, we used a genetic approach to test this hypothesis in vivo in the mouse. We show that Rack1 knock-down in the mouse melanoma cell line B16 reduces invasiveness and induces cell differentiation. We have developed the first mouse model for RACK1 gain of function, Tyr::Rack1-HA transgenic mice, targeting RACK1 to melanocytes in vivo. RACK1 overexpression was not sufficient to initiate melanomas despite activated ERK and AKT. However, in a context of melanoma predisposition, RACK1 overexpression reduced latency and increased incidence and metastatic rate. In primary melanoma cells from Tyr::Rack1-HA, Tyr::NRas^Q61K mice, activated JNK (c-Jun N-terminal kinase) and activated STAT3 (signal transducer and activator of transcription 3) acted as RACK1 oncogenic partners in tumoral progression. A sequential and coordinated activation of ERK, JNK and STAT3 with RACK1 is shown to accelerate aggressive melanoma development in vivo.

Mineralocorticoid regulation of cell function: the role of rapid signalling and gene transcription pathways

The mineralocorticoid receptor (MR) and mineralocorticoids regulate epithelial handling of electrolytes, and induces diverse effects on other tissues. Traditionally, the effects of MR were ascribed to ligand-receptor binding and activation of gene transcription. However, the MR also utilises a number of intracellular signalling cascades, often by transactivating unrelated receptors, to change cell function more rapidly. Although aldosterone is the physiological mineralocorticoid, it is not the sole ligand for MR. Tissue-selective and mineralocorticoid-specific effects are conferred through the enzyme 11β-hydroxysteroid dehydrogenase 2, cellular redox status and properties of the MR itself. Furthermore, not all aldosterone effects are mediated via MR, with implication of the involvement of other membrane-bound receptors such as GPER. This review will describe the ligands, receptors and intracellular mechanisms available for mineralocorticoid hormone and receptor signalling and illustrate their complex interactions in physiology and disease.