Extracellular Receptor Kinase Research Articles

Cornuside alleviates psoriasis-like skin lesions in mice by relieving inflammatory effects

Psoriasis is a chronic inflammatory skin disease substantially affecting the quality of life, with no complete cure owing to its complex pathogenesis. Cornuside, a major bioactive compound present in Cornus officinalis Sieb. et Zucc., which is a well-known traditional Chinese medicine with a variety of biological and pharmacological activities, such as anti-apoptotic, antioxidant, and anti-inflammatory properties. However, its effects on psoriasis remain unclear. Our preliminary analysis of network pharmacology showed that cornuside may be involved in psoriasis by regulating the inflammatory response and IL-17 signaling pathway. Thus, we investigated the protective role and mechanism of cornuside in the pathogenesis of psoriasis in an imiquimod (IMQ)-induced psoriasis mouse model. In-vivo experiments demonstrated that cornuside-treated mice had reduced skin erythema, scales, thickness, and inflammatory infiltration. The Psoriasis Area Severity Index score was significantly lower than that of the IMQ group. Flow cytometry analysis indicated that cornuside effectively inhibited Th1- and Th17-cell infiltration and promoted aggregation of Th2 cells in skin tissues. Cornuside also inhibited the infiltration of macrophages to the skin. Furthermore, in-vitro experiments indicated that cornuside also decreased the polarization of M1 macrophages and reduced the levels of associated cytokines. Western blotting demonstrated that cornuside suppressed the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular receptor kinase (ERK) in bone marrow-derived macrophages. Our findings indicate that cornuside has a protective effect against IMQ-induced psoriasis by inhibiting M1 macrophage polarization through the ERK and JNK signaling pathways and modulating the infiltration of immune cells as well as the expression of inflammatory factors.

Simultaneously targeting extracellular vesicle trafficking and TGF-β receptor kinase activity blocks signaling hyperactivation and metastasis

Metastasis is the leading cause of cancer-related deaths. Transforming growth factor beta (TGF-β) signaling drives metastasis and is strongly enhanced during cancer progression. Yet, the use of on-target TGF-β signaling inhibitors in the treatment of cancer patients remains unsuccessful, highlighting a gap in the understanding of TGF-β biology that limits the establishment of efficient anti-metastatic therapies. Here, we show that TGF-β signaling hyperactivation in breast cancer cells is required for metastasis and relies on increased small extracellular vesicle (sEV) secretion. Demonstrating sEV’s unique role, TGF-β signaling levels induced by sEVs exceed the activity of matching concentrations of soluble ligand TGF-β. Further, genetic disruption of sEV secretion in highly-metastatic breast cancer cells impairs cancer cell aggressiveness by reducing TGF-β signaling to nearly-normal levels. Otherwise, TGF-β signaling activity in non-invasive breast cancer cells is inherently low, but can be amplified by sEVs, enabling invasion and metastasis of poorly-metastatic breast cancer cells. Underscoring the translational potential of inhibiting sEV trafficking in advanced breast cancers, treatment with dimethyl amiloride (DMA) decreases sEV secretion, TGF-β signaling activity, and breast cancer progression in vivo. Targeting both the sEV trafficking and TGF-β signaling by combining DMA and SB431542 at suboptimal doses potentiated this effect, normalizing the TGF-β signaling in primary tumors to potently reduce circulating tumor cells, metastasis, and tumor self-seeding. Collectively, this study establishes sEVs as critical elements in TGF-β biology, demonstrating the feasibility of inhibiting sEV trafficking as a new therapeutic approach to impair metastasis by normalizing TGF-β signaling levels in breast cancer cells.

Cornuside improves murine autoimmune hepatitis through inhibition of inflammatory responses.

Autoimmune hepatitis (AIH) poses an important public health concern worldwide, with few therapeutic options available. Cornuside, a primary cornel iridoid glycoside present in Cornus officinalis Sieb. et Zucc., is a well-known traditional Chinese medicine that possesses anti-inflammatory, antioxidant and anti-apoptotic properties. However, the effects of cornuside on autoimmune diseases including AIH is still not defined, neither is clear on the mechanisms of cornuside in the suppression of inflammatory responses. The study was aimed to investigate the therapeutic effects of cornuside on AIH using murine models. A murine model of AIH induced by concanavalin A (Con A) was used to examine the pharmacological activity of cornuside in suppressing the inflammatory responses in vivo. C57BL/6J mice were intravenously with different doses of cornuside and challenged with 18mg/kg Con A 3h later. Network pharmacological analysis was performed to identify the potential target genes and signaling pathways by cornuside in AIH. Next serum and liver tissues were collected 12h after Con A injection to analyze the levels of markers for hepatic injury, apoptosis, oxidative stress, immune responses, and inflammation. Network pharmacological analysis revealed that cornuside may modulate oxidative stress and apoptosis in AIH. Compared with the Con A group, cornuside pretreatment significantly reduced the serum levels of alanine aminotransferase and aspartate aminotransferase, improving histopathological damage and apoptosis in the livers. In addition, cornuside decreased the levels of malondialdehyde, myeloperoxidase, but increased superoxide dismutase levels, suggesting the relieving of oxidative stress. Furthermore, cornuside suppressed the activation of T and natural killer T cells, whereas the proportion of myeloid-derived suppressor cells was significantly increased. The production of proinflammatory cytokines, including interleukin (IL)-6, IL-12, IL-1β, and tumor necrosis factor-alpha (TNF-α), was also clearly decreased. Finally, western blot analysis displayed that cornuside inhibited the phosphorylation of extracellular receptor kinase (ERK) and c-Jun N-terminal kinase (JNK). We demonstrated that cornuside has protective effects for Con A-induced immune-mediated hepatitis by suppressing the oxidative stress, apoptosis, and the inflammatory responses through the ERK and JNK signaling pathways, as well as by modulating the activation and recruitment of immune cells.

Potential therapeutic targets and medications for arteriovenous malformations of the central nervous system

Arteriovenous malformations (AVMs) of the central nervous system are high-flow arteriovenous shunts that lead to considerable risks of hemorrhagic stroke and neurological deficits in young patients. Due to the complex angioarchitecture and their close anatomical relationship with the brain and spinal cord, the management of brain and spinal AVMs is challenging. Conventional invasive treatments, including microsurgery, endovascular embolization, and stereotactic radiosurgery, are associated with considerable risks and unsatisfactory efficacy. In addition, the lack of medications for AVMs represents an unmet clinical need. In recent years, the pathogenesis of AVMs has been progressively explored. The increased understanding of the mechanisms of the formation, progression, and rupture of AVMs has opened up several potential directions for AVM pharmacotherapy. In recent years, some promising drugs targeting angiogenesis, inflammation, vessel wall integrity, and the mitogen-activated protein kinase (MAPK)-extracellular receptor kinase (ERK) signaling pathway have been tested in a series of clinical investigations. In this review, we summarize the potential mechanisms, preliminary efficacy, and side effects of the candidate medications, including bevacizumab, minocycline or doxycycline, thalidomide, and trametinib, in the treatment of brain and spinal AVMs.

Abstract B069: Inhibiting pancreatic cancer growth by dual targeting of ERK and PI3K signaling

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with a dismal 5-year survival rate of only 11%. Due to its late-stage detection and metastasis, surgery is not an option in most cases, and chemotherapy has become the sought-after strategy to combat PDAC. Current treatment strategies involve combining chemotherapeutic agents; however, these drugs show limited response in some patients and frequently result in acquired drug resistance. There is a need for new treatment approaches to more specifically target molecules involved in PDAC growth. The KRAS gene is mutated in almost 95% of the pancreatic cancers resulting in hyperactivated K-ras protein, which activates downstream growth-promoting signaling pathways such as extracellular receptor kinase (ERK) and phosphatidylinositol 3 kinase (PI3K). Thus, we hypothesized that the combination of ERK and PI3K inhibitors would lead to enhanced PDAC growth inhibition compared to either drug alone. To test our hypothesis, we used SCH772984 (an ERK1/2 inhibitor) and pictilisib (a class I PI3K inhibitor) to perform a cell viability assay using human PDAC cell lines, MIA PaCa-2 and PANC-1, for both 2-D cells and 3-D spheroids. Our results indicated that the cancer cells treated with both drugs showed reduced cell proliferation compared to either of the drugs administered individually. Our next steps will involve evaluation of this combination in animal models as well as testing these drugs against clinical PDAC samples. This research may lead to a novel combination of pictilisib and SCH772984 to enhance treatment for PDAC patients. Citation Format: Gauthami G. Nair, Katie Reindl, Mohiuddin Quadir. Inhibiting pancreatic cancer growth by dual targeting of ERK and PI3K signaling [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B069.

Dexmedetomidine represses TGF-β1-induced extracellular matrix production and proliferation of airway smooth muscle cells by inhibiting MAPK signaling pathway.

Airway remodeling is implicated in the pathogenesis of asthma, and abnormal proliferation of airway smooth muscle cells (ASMCs) contribute to airway remodeling. Inflammatory mediator, transforming growth factor-β1 (TGF-β1), stimulates the proliferation of ASMCs, and is associated with airway remodeling in asthma. Dexmedetomidine (DEX) has been widely used in the adjuvant therapy of acute asthma. The potential effects of DEX on extracellular matrix (ECM) production and proliferation of ASMCs were investigated in this study. Human ASMCs were incubated with TGF-β1 for 48 hours, and then treated with different concentrations of DEX for another 24 hours. Cell proliferation was detected by MTT and BrdU (5'-bromo-2'-deoxyuridine) staining. Flow cytometry was used to assess cell apoptosis, and western blot was applied to identify the underlying mechanism. TGF-β1 induced increase in cell viability and bromodeoxyuridine (BrdU) positive cells in ASMCs while repressed cell apoptosis. Second, TGF-β1-induced ASMCs were then treated with different concentrations of DEX. Cell viability of TGF-β1-induced ASMCs was decreased by incubation of DEX. The number of BrdU positive cells in TGF-β1-induced ASMCs was reduced by incubation of DEX. Moreover, incubation of DEX promoted cell apoptosis of TGF-β1-induced ASMCs. Third, incubation of DEX attenuated TGF-β1-induced increase in fibronectin, collagen I, MMP9, and versican in ASMCs. Lastly, the up-regulation of phosphorylated extracellular receptor kinase (p-ERK), phosphorylated Jun N-terminal Kinase (p-JNK), and p-p38 in TGF-β1-induced ASMCs was reversed by incubation of DEX. DEX suppressed TGF-β1-induced ECM production and proliferation of ASMCs through inactivation of p38 mitogen-activated protein kinase (MAPK) pathway, providing a potential strategy for prevention of asthma.

Influence of pretreatment of insulin on the phosphorylation of extracellular receptor kinase by gonadotropin-releasing hormone and gonadotropins in cultured human granulosa cells

ObjectiveTo investigate the influence of pretreatment of insulin on the phosphorylation of ERK1/2 by gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) in cultured human granulosa cells. Study designHuman granulosa cells were collected from 20 women (age: 20–35 years) who underwent controlled ovarian hyperstimulation for in vitro fertilization and embryo transfer at Asan Medical Center (Seoul, South Korea). The presence of the receptors for insulin, GnRH, FSH, and LH in human granulosa cells was identified by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The granulosa cells were treated with 10 nM insulin or 10 nM GnRH for 5 min or 30 min and with 10 nM FSH or 10 nM LH for 24 h or 48 h. The cells were also pretreated with insulin for 30 min prior to treatment with GnRH, FSH, or LH. Western blot analysis was used to analyze ERK1/2 phosphorylation. ResultsRT-PCR showed that the receptors for insulin, GnRH, FSH, and LH were expressed in human granulosa cells. Insulin, GnRH, FSH, and LH could activate ERK1/2 phosphorylation. Pretreatment with insulin inhibited ERK1/2 phosphorylation induced by GnRH and FSH while augmenting ERK1/2 phosphorylation induced by LH. ConclusionsInsulin might have a negative effect on GnRH and FSH regulation by attenuating the action of GnRH and FSH in the phosphorylation of ERK1/2 in human granulosa cells. In contrast, insulin might have a positive effect on LH regulation by potentiating the action of LH in the phosphorylation of ERK1/2. Our results showed that insulin is clearly an important regulator of human reproductive function at the ovarian level.

Nanomicellar curcuminoids attenuates renal ischemia/reperfusion injury in rat through prevention of apoptosis and downregulation of MAPKs pathways

Renal ischemia/reperfusion (I/R) injury is considered as a main problem in clinical practice. Curcuminoids, the active constituents of turmeric, seem to have potential renoprotective effects. However, the poor bioavailability of curcuminoids restricts their therapeutic effects. In the present study, the effect of nanomicellar curcuminoids (NC) treatment on renal function, histology, total antioxidant capacity (TAC), total oxidative stress (TOS), caspase-3 level as well as mitogen activated protein kinases (MAPKs: JNK, p38 and ERK) phosphorylation were evaluated following renal I/R. Adult male Sprague-Dawley rats were administered NC at the dose of 25mg/kg 1h before renal ischemia induction. The animals were subjected to bilateral renal ischemia for 60min and reperfusion for 24h. Subsequently, blood urea nitrogen (BUN), creatinine (Cr), renal histopathology, TAC, TOS, and oxidative stress index, cleaved caspase-3 level, Bax and MAPKs signaling were evaluated. The results indicated that NC pretreatment at the dose of 25mg/kg significantly improved renal function as well as histolopatholgical damages. Moreover, NC reduced the level of renal oxidative stress, cleaved caspase-3 and Bax (as the proapoptotic proteins) and suppressed the activated Jun N-terminal Kinase (JNK), p38 and extracellular receptor kinase (ERK) signaling induced by renal I/R. The findings of the current study indicate that NC might prevent the injury induced by renal I/R through suppression of oxidative stress, apoptosis and MAPKs pathways.

Inhibition of metastasis and suppression of pERK1/2 and pFAK expression by Solanum xanthocarpum crude extracts in human lung cancer cell line A549 in vitro

Solanum xanthocarpum is an important part of natural remedies for lung in Ayurveda. Lung cancer metastasis is a major challenge in the present time. Expressions and activation of focal adhesion kinase (FAK) and extracellular receptor kinases 1 and 2 (ERK1/2) are key checkpoints in cancer which lead to an invasion, epithelial-mesenchymal transition (EMT) and metastatic progression. In this study, the efficacy of the whole plant and root crude extracts prepared in ethyl acetate and chloroform on highly metastatic lung cancer cell line A549 was evaluated. The effect of crude extracts on cell migration was scrutinized using transwell migration assessment. The phosphorylated forms of proteins, pFAK and pERK1/2 levels, were estimated using ELISA. Zymography technique was utilized to evaluate the activities of MMP-2 and MMP-9 proteins. The EMT markers, vimentin and N-cadherin gene expressions were analyzed using semi-quantitative RT-PCR. The extracts significantly reduced single-cell migration. The expression levels of pFAK and pERK1/2 notably decreased and FAK and ERK1/2 remained unchanged. Moreover, gelatinase activity, vimentin and N-cadherin expression were also significantly reduced in treated cells compared to untreated cells. The crude extracts of S. xanthocarpum impaired the metastatic progression of A549 cells in vitro.

Long-Lasting Activity of ERK Kinase Depends on NFATc1 Induction and Is Involved in Cell Migration-Fusion in Murine Macrophages RAW264.7.

Macrophages are mononuclear cells that become osteoclasts (OCs) in the presence of two cytokines, macrophage colony-stimulating factor (M-CSF), and receptor activator of NF-κB ligand (RANKL). RANKL binding to its specific receptor RANK leads to OCs differentiation mainly by nuclear factor of activated T-cells cytoplasmic 1 (NFATc1). In our previous study, the analysis of the protein network in NFATc1-knockdown cells, using the Ingenuity Pathway Analysis (IPA), showed a link between NFATc1 and Mitogen-activated protein kinase kinase (MEK)-extracellular receptor kinase (ERK) signaling pathway. Therefore, this study aimed to extend our knowledge of the relationship between NFATc1 and the ERK. Here, we demonstrate that delayed ERK1/2 phosphorylation in pre-OC RANKL-induced depends on NFATc1. Indeed, the knockdown of NFATc1 reduced the phosphorylation of ERK1/2 (60%) and the pharmacological inhibition of the ERK1/2 kinase activity impairs the expression of NFATc1 without preventing its translocation into the nucleus. Furthermore, silencing of NFATc1 significantly reduced RANKL-induced migration (p < 0.01), and most pre-OCs are still mononuclear after 48 h (80 ± 5%), despite the presence of actin rings. On the other hand, the inhibitors FR180204 and PD98059 significantly reduced RANKL-induced cell migration (p < 0.01), leading to a reduction in the number of multinucleated cells. Finally, we suggest that long-lasting ERK activity depends on NFATc1 induction and is likely linked to cell migration, fusion, and OC differentiation.

EXTH-16. TREATMENT OF THREE DIFFERENT BRAF-V600E POSITIVE BRAIN TUMORS WITH VEMURAFENIB AND DABRAFENIB/TRAMETINIB: A CASE SERIES

Abstract BACKGROUND The BRAF-V600E gene is a protein kinase involved in regulation of the mitogen activated protein kinase pathway (MAPK/MEK) and downstream extracellular receptor kinase (ERK). The BRAF-V600E mutation has a significant role in the progression of pediatric brain tumors. 85% of pediatric CNS tumors express the BRAF mutation. Thus, BRAF targeted therapy in pediatric CNS malignancies has potential to become the standard of care for tumors expressing this mutation. OBJECTIVE Current pediatric CNS brain tumor treatment focuses on chemotherapy and radiation, causing significant toxic side effects for patients. The significance of this case series lies in relaying our experience using targeted therapy in BRAF-V600E positive CNS pediatric brain tumors. METHODS We followed the disease course, progression, and treatment of three pediatric patients with three different CNS tumors. Each of these individuals was treated with surgical resection, chemotherapy, and/or radiation as per standard protocol. When that modality failed to reduce tumor progression, we found that each of their different tumors was BRAF-V600E positive and they were all started on targeted therapy. DISCUSSION Vemurafenib, Dabrafenib, and Trametinib are BRAF-V600E/MEK inhibitors that were initially used to treat melanomas. However, more research has shown that various pediatric CNS tumors are BRAF-V600 positive. Therapy with these BRAF inhibitors has been shown to slow tumor progression, but toxicity can be severe. This case series shows one patient with successful tumor regression, one patient with prolonged disease stabilization, and one patient with initial response but subsequent progression and ultimate death. It has been shown that using BRAF inhibitors in lower grade CNS tumors are more effective than higher grade CNS tumors. CONCLUSION The success of Vemurafenib and Dabrafenib/Trametinib in causing pediatric CNS tumor regression is promising, but further studies are needed to solidify their role in pediatric CNS cancers.

Increased expression of CXCL2 in ACPA-positive rheumatoid arthritis and its role in osteoclastogenesis.

Anti-citrullinated protein/peptide antibodies (ACPA) play important roles in the pathogenesis of rheumatoid arthritis (RA). ACPA-positive (ACPA+ ) and ACPA-negative (ACPA- ) RA were suggested to be different disease subsets, with distinct differences in genetic variation and clinical outcomes. The aims of the present study were to compare gene expression profiles in ACPA+ and ACPA- RA, and to identify novel candidate gene signatures that might serve as therapeutic targets. Comprehensive transcriptome analysis of peripheral blood mononuclear cells (PBMCs) from ACPA+ and ACPA- RA patients and healthy controls was performed via RNA sequencing. A validation cohort was used to further investigate differentially expressed genes via polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Spearman's correlation test was used to evaluate the correlation of differentially expressed genes and the clinical and laboratory data of the patients. The role of differentially expressed genes in osteoclastogenesis was further investigated. Expression of C-X-C motif chemokine ligand 2 (CXCL2) was significantly increased in ACPA+ RA than in ACPA- RA, which was validated in PBMCs and serum. CXCL2 promoted the migration of CD14+ monocytes and increased osteoclastogenesis in RA patients. RAW264.7 macrophages were used to investigate specific mechanisms, and the results suggested that CXCL2 stimulated osteoclastogenesis via extracellular receptor kinase (ERK) mitogen-activated protein kinase (MAPK) and nuclear factor kappa B pathways. In conclusion, CXCL2 was highly expressed in ACPA+ RA than in ACPA- RA. CXCL2 promoted osteoclastogenesis and was related to bone erosion in RA, which suggests that the blockade of CXCL2 might be a novel strategy for the treatment of RA.

Loss of skeletal muscle area and fat-free mass during dabrafenib/trametinib and vemurafenib/cobimetinib treatments in patients with BRAF-mutant metastatic malignant melanoma.

This study aimed to assess whether dabrafenib/trametinib and vemurafenib/cobimetinib treatments are associated with a change in skeletal muscle area (SMA) and total fat-free mass (FFM) assessed by computed tomography (CT), and to compare the efficacy and safety profile of these treatments in patients with metastatic melanoma. Thirty-one patients treated with B-Raf proto-oncogene, serine/threonine kinase/MAPK extracellular receptor kinase inhibitors were included between 2016 and 2019. Eighteen patients received dabrafenib/trametinib and remaining patients received vemurafenib/cobimetinib. CT scans were performed at baseline and at 4-6 months of follow-up to measure cross-sectional areas of SMA. FFM and skeletal muscle index (SMI) values were calculated. Of the patients, including 18 treated with dabrafenib/trametinib (58.1%) and 13 with vemurafenib/cobimetinib (41.9%); 58.1% were male, 41.9% were female and median age was 52 years. A significant decrease in SMA was observed after dabrafenib/trametinib and vemurafenib/cobimetinib treatments (P = 0.003 and P = 0.002, respectively). A significant decrease in FFM values was observed after dabrafenib/trametinib and vemurafenib/cobimetinib treatments (P = 0.003 and P = 0.002, respectively). Dose-limiting toxicity (DLT) was observed in 35.9% of the patients with sarcopenia. No significant difference was seen between the dabrafenib/trametinib and vemurafenib/cobimetinib groups in median progression-free survival (PFS) (11.9 vs. 7.3 months, respectively, P = 0.28) and in median overall survival (OS) (25.46 vs. 13.7 months, respectively, P = 0.41). Baseline sarcopenia was not significantly associated with PFS or OS (P = 0.172 and P = 0.326, respectively). We found a significant decrease in SMI values determined at 4-6 months compared to the values before treatment both in dabrafenib/trametinib and vemurafenib/cobimetinib groups. DLT was similar with both treatments. Baseline sarcopenia was not significantly associated with PFS or OS.

Icariin ameliorates the cognitive function in an epilepsy neonatal rat model by blocking the GluR2/ERK I/II pathway.

The present study was performed to evaluate the protective effects of icariin on cognitive function in ahypoxia-induced neonatal epilepsy rat model. Neonatal epilepsy was induced in rat pups on postnatal day (PD) 20 by induction of hypoxia for 15 minutes. Rats were treated intraperitoneally with icariin at 75 mg/kg 1 hour before the induction of hypoxia. The effects of icariin were examined by estimating seizure stage, cognitive function and parameters of electroencephalography (EEG) in this neonatal epilepsy rat model. Parameters of oxidative stress and expression of proteins were examined in the brain tissue of the neonatal epilepsy rat model by histopathological study and Western blotting analysis, respectively. The results of this study suggest that treatment with icariin ameliorates the changes in seizure stage, number of seizures and parameters of EEG in hypoxia-induced neonatal epilepsy rats. Oxidative stress and apoptosis were decreased in the brain tissue of the icariin treatment group compared to the hypoxia group. Moreover, treatment with icariin ameliorated the altered expression of glutamate ionotropic receptor AMPA type subunit 2 (GluR2) and extracellular receptor kinase (ERK I/II) proteins in the brain tissue of hypoxia-induced epilepsy rats. Histopathological study also showed that icariin treatment improved the histopathology of brain tissue of hypoxia-induced epilepsy rats. In conclusion, the results of the present study suggest that icariin protects against neuronal injury and improves cognitive function in hypoxia-induced neonatal epilepsy rats by modulating the GluR2/ERK I/II pathway.

Nobiletin Inhibits Helicobacterium pylori Infection-Induced Gastric Carcinogenic Signaling by Blocking Inflammation, Apoptosis, and Mitogen-Activated Protein Kinase Events in Gastric Epithelial-1 Cells.

Helicobacter pylori causes a Gram-negative bacterial infection that can increase the risk of gastric cancer. Consequently, meticulous prevention of an H. pylori infection is significant for averting gastric cancer in humans. Nobiletin, an important dietary polymethoxylated flavonoid in citrus fruits, possesses multidimensional pharmaceutical properties, including its ability to act as an anticancer, anti-inflammatory, antioxidative, cardiovascularly defensive, neuroprotective, and antimetabolic agent. Our study evaluates the role of nobiletin in inflammation-mediated gastric carcinogenic signaling of H. pylori-arbitrated coculture in the human gastric epithelial (GES)-1 cell line. Our results show that the culture system of H. pylori-tainted GES-1 cells demonstrates maximum fabrication of reactive oxygen species (ROS), mediating DNA injury and augmenting nuclear fragmentations. Treatment with nobiletin reduces ROS levels and apoptotic morphological changes by dual staining and decreases levels of lipid peroxides and glutathione content in H. pylori-infected GES-1 cells. Phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT)/phosphatase and tensin homolog signaling have been implicated to affect cell endurance, inflammation, proliferation, and carcinogenic activity in gastric GES-1 cells. We find that nobiletin strongly impedes tumor necrosis factor-α, interleukin-6, cyclooxygenase-2, PI3K, AKT, and mitogen-activated protein kinase molecules, including p38, extracellular receptor kinase 1, and c-Jun amino-terminal expression in H. pylori-infected GES-1 cells. We conclude that nobiletin potentially impedes H. pylori infection and its related activation, likely preventing H. pylori infection-mediated gastric cancer.

Microenvironment-sensing, nanocarrier-mediated delivery of combination chemotherapy for pancreatic cancer.

Limited effectiveness of Raf and MEK inhibitors has impelled the interest to use the inhibitors of Extra-cellular Receptor Kinase (ERK) pathway in combination with Gemcitabine (GEM) in pancreatic cancer. However, off-target abundance of ERK receptors, challenging physico-chemical properties, and dose-limiting toxicity of the inhibitor has presented critical challenges towards fabricating this combination amenable for clinical translation. Herein we report a pharmaceutical nanoformulation of GEM and an ERK inhibitor (SCH 772984) co-stabilized within a pH-sensing nanocarrier (NC, with a hydrodynamic diameter of 161 ± 5.0nm). The NCs were modularly derived from a triblock, self-assembling copolymer, and were chemically conjugated with GEM and encapsulated with SCH772984 at a loading content of 20.2% and 18.3%, respectively. Through pH-mediated unfolding of the individual blocks of the copolymer, the NCs were able to control the release of encapsulated drugs, traffic through cellular membranes, engage target receptors, suppress proliferation of pancreatic cancer cells, and accumulate at disease sites. Collectively our studies showed the feasibility of co-delivery of a combination chemotherapy consisting of GEM and an ERK inhibitor from a NC platform, which can sense and respond to tumor microenvironment of pancreatic cancer setting.

Sphingosine-1-Phosphate Receptor Agonist Fingolimod Reduces Myocardial Ischemia-Reperfusion Injury and Apoptosis Increasing Long-Term Left Ventricular Function after Heart Transplantation

Purpose Fingolimod, a sphingosine-1-phosphate receptor agonist, is approved for the treatment of multiple sclerosis and exerts antiapoptotic properties. We hypothesized that sphingosine-1-phosphate receptor activation with fingolimod in the donor hearts could protect against ischemia/reperfusion injury and preserve myocardial function in a heterotopic rat heart transplantation model. Methods Before explantation, donor Wistar rats received finfolimod (1 mg/kg iv, n= 40) or saline (control, n=40). The hearts were excised, stored in cold preservation solution for 1 hour and heterotopically transplanted. Left ventricular function of the graft and myocardial markers of apoptosis, nitro-oxidative stress, inflammation and fibrosis have been assessed after 24 hour (early phase) and 1 month (late phase) from transplantation. Results Fingolimod treatment activated the cardioprotective reperfusion injury salvage kinase Akt and extracellular receptor kinase 1/2 in the early phase after transplantation, leading to decreased cardiomyocyte apoptosis (TUNEL) and reduced myocardial nitro-oxidative stress (malondialdehyde, nitrotyrosine) and inflammation (CCL5/RANTES). In the late phase fingolimod decreased interstitial fibrosis and improved LV systolic and diastolic functions (pressure-volume analysis). Conclusion Sphingosine-1-phosphate receptor activation with fingolimod before heart transplantation activates anti-apoptotic and anti-inflammatory pathway reducing graft ischemia-reperfusion injury. This produces a reduced myocardial fibrosis and improved left ventricular function in a chronic phase. Fingolimod might represent a useful tool for cardioprotection in the clinical setting of heart transplantation surgery soon. Fingolimod, a sphingosine-1-phosphate receptor agonist, is approved for the treatment of multiple sclerosis and exerts antiapoptotic properties. We hypothesized that sphingosine-1-phosphate receptor activation with fingolimod in the donor hearts could protect against ischemia/reperfusion injury and preserve myocardial function in a heterotopic rat heart transplantation model. Before explantation, donor Wistar rats received finfolimod (1 mg/kg iv, n= 40) or saline (control, n=40). The hearts were excised, stored in cold preservation solution for 1 hour and heterotopically transplanted. Left ventricular function of the graft and myocardial markers of apoptosis, nitro-oxidative stress, inflammation and fibrosis have been assessed after 24 hour (early phase) and 1 month (late phase) from transplantation. Fingolimod treatment activated the cardioprotective reperfusion injury salvage kinase Akt and extracellular receptor kinase 1/2 in the early phase after transplantation, leading to decreased cardiomyocyte apoptosis (TUNEL) and reduced myocardial nitro-oxidative stress (malondialdehyde, nitrotyrosine) and inflammation (CCL5/RANTES). In the late phase fingolimod decreased interstitial fibrosis and improved LV systolic and diastolic functions (pressure-volume analysis). Sphingosine-1-phosphate receptor activation with fingolimod before heart transplantation activates anti-apoptotic and anti-inflammatory pathway reducing graft ischemia-reperfusion injury. This produces a reduced myocardial fibrosis and improved left ventricular function in a chronic phase. Fingolimod might represent a useful tool for cardioprotection in the clinical setting of heart transplantation surgery soon.

Docosahexaenoic acid modulates brain-derived neurotrophic factor via GPR40 in the brain and alleviates diabesity-associated learning and memory deficits in mice

GPR40 (Free fatty acid receptor 1) has emerged as an important therapeutic target for diabetes. Several studies have demonstrated the association of comorbid psychiatric conditions with decreased n-3 polyunsaturated fatty acids, which may act as an agonist for GPR40. In this study, we for the first time provide evidence of reduced GPR40 signaling in the hippocampus and cortex which may be a critical underlying mechanism mediating cognitive deficits in diabesity (diabetes and obesity together). Specifically, we showed decreased GPR40 and brain-derived neurotrophic factor (BDNF) expression in the brain regions of high-fat-diet-induced obese and db/db mice. Next, we demonstrated that chronic treatment with docosahexaenoic acid (DHA) or the synthetic GPR40 agonist, GW9508, significantly alleviates cognitive functions in mice, which correlates with increased BDNF expression in the hippocampus. This supports the hypothesis that DHA improves cognitive function in diabesity via GPR40 agonism. We also showed that DHA specifically activates GPR40 and modulates BDNF expression in primary cortical neurons mediated by the extracellular receptor kinase (ERK) and P38-mitogen-activated protein kinase (MAPK) pathways. Finally, the central nervous system (CNS)-specific blockade of GPR40 signaling abrogated the memory potentiating effects of DHA, and induction of BDNF expression in the hippocampus. Thus, we provided evidence that DHA stimulation of GPR40 mediate some of DHA's beneficial effects in metabolic syndrome and identify GPR40 as a viable therapeutic target for the treatment of CNS-related comorbidities associated with diabesity.

The role of mitogen-activated protein kinase-extracellular receptor kinase pathway in female fertility outcomes: a focus on pituitary gonadotropins regulation.

Mammalian reproduction systems are largely regulated by the secretion of two gonadotropins, that is, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The main action of LH and FSH on the ovary is to stimulate secretion of estradiol and progesterone, which play an important role in the ovarian function and reproductive cycle control. FSH and LH secretions are strictly controlled by the gonadotropin-releasing hormone (GnRH), which is secreted from the hypothalamus into the pituitary vascular system. Maintaining normal secretion of LH and FSH is dependent on pulsatile secretion of GnRH. Extracellular signal-regulated kinase (ERK) proteins, as the main components of mitogen-activated protein kinase (MAPK) signaling pathways, are involved in the primary regulation of GnRH-stimulated transcription of the gonadotropins' α subunit in the pituitary cells. However, GnRH-stimulated expression of the β subunit has not yet been reported. Furthermore, GnRH-mediated stimulation of ERK1 and ERK2 leads to several important events such as cell proliferation and differentiation. In this review, we briefly introduce the relationship between ERK signaling and gonadotropin secretion, and its importance in female infertility.

Influence of pretreatment of insulin on phosphorylation of extracellular receptor kinase by gonadotropin releasing hormone in cultured mouse granulosa gells

Background: To investigate the influence of pretreatment of insulin on the phosphorylation of extracellular receptor kinase (ERK) by gonadotropin releasing hormone (GnRH) in cultured mouse granulosa cells. Materials and Methods: The granulosa cells from the mouse were collected simultaneously from the ovaries of gonadotropin-primed ICR female mice. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the expression of the receptors of GnRH and insulin. The granulosa cells were cultured with ten nM of insulin, ten nM of GnRH, and ten nM of insulin pretreatment before ten nM of GnRH. Western blotting was used for analysis of phosphorylation of ERK. Student t-test and Dunnett’s comparison test were used for statistical analysis and statistical significance was defined as p Results: The authors confirmed the presence of receptors of GnRH and insulin in the mouse granulosa cells by RTPCR. Both insulin and GnRH could activate ERK phosphorylation. Pretreatment of insulin for 30 minutes before GnRH treatment inhibited ERK phosphorylation by GnRH. Conclusion: Insulin might have a negative effect of GnRH regulation of mouse ovarian physiology by inhibition of GnRH activation of ERK. Based on these study results, the authors demonstrated the role of insulin as a delicate modulator of reproductive function.