Extracellular Signal-regulated Kinase Research Articles

Exogenous hydrogen sulfide improves non-alcoholic fatty liver disease by inhibiting endoplasmic reticulum stress/NLRP3 inflammasome pathway.

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease worldwide, and its exact pathogenesis has not been fully studied. Hydrogen sulfide (H2S) is the third gas signaling molecule discovered in mammals, following nitric oxide and carbon monoxide. It has the effects of anti-inflammation, anti-apoptosis, and so on, thereby playing an important role in many diseases. However, the role and mechanism of exogenous H2S in NAFLD are not fully understood. In this study, we constructed in vitro and in vivo NAFLD models by feeding mice a high-fat diet and stimulating hepatocytes with palmitic acid, respectively, to investigate the improvement effect and mechanism of exogenous H2S on NAFLD. The results showed that NaHS (a donor of H2S) treatment alleviated lipid accumulation, inflammation, apoptosis and pyroptosis, and downregulated endoplasmic reticulum (ER) stress and nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NRRP3) inflammasome in NAFLD. The activation of NLRP3 inflammasome weakened NaHS improvement of NAFLD, indicating that exogenous H2S ameliorated NAFLD by inhibiting NLRP3 inflammasome-mediated lipid synthesis, inflammation, apoptosis and pyroptosis. Similarly, the activation of ER stress weakened NaHS improvement of NAFLD and NaHS inhibition of NLRP3 inflammasome, indicating that exogenous H2S suppressed NLRP3 inflammasome by downregulating ER stress, thus improving NAFLD. Additionally, the protein expressions of NLRP3 and cleaved caspase-1 were downregulated after inhibiting the reactive oxygen species (ROS)/extracellular signal-regulated kinases (ERK) and ROS/thioredoxin-interacting protein (TXNIP) pathways, indicating that ER stress activated NLRP3 inflammasome through the ROS/ERK and ROS/TXNIP pathways. In conclusion, our results indicated that exogenous H2S inhibited NLRP3 inflammasome-mediated hepatocytes inflammation, lipid synthesis, apoptosis and pyroptosis by downregulating ER stress, thereby improving NAFLD; Furthermore, ER stress activated NLRP3 inflammasome through the ROS/ERK and ROS/TXNIP pathways in NAFLD. ER stress/NLRP3 inflammasome is expected to become a new target of H2S for treating NAFLD.

Network pharmacology and experimental verification to investigate the mechanism of isoliquiritigenin for the treatment of Alzheimer’s disease

Isoliquiritigenin (ISL), a flavone isolated from licorice, has been demonstrated to exhibit anti-inflammatory and antioxidant properties in the treatment of Alzheimer’s disease (AD). However, the molecular details of the contribution of ISL to AD remain largely elusive. The present study aimed to investigate the molecular mechanisms of ISL against AD. In this study, AD targets and ISL targets were collected via different databases. The overlapped targets between AD and ISL were generated with Venny. Then we performed Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analyses on these common targets. The protein-protein interaction (PPI) network was constructed and clusters were obtained using the Molecular Complex Detection (MCODE) and the Cytohubba plugins. Further, molecular docking study was performed for these core targets. Subsequently, the receiver operating characteristic (ROC) curve analysis and the assessment of hub gene expression levels between AD and healthy individuals were used to estimate a possible link between target genes in AD. Finally, experiments were conducted to verify the therapeutic mechanism of ISL in lipopolysaccharide (LPS)-induced BV2 microglial cells. GO and KEGG pathway analysis found that ISL was significantly enriched in regulation of mitogen-activated protein kinase (MAPK) signaling pathway. The PPI network manifested 7 key targets including albumin (ALB), epidermal growth factor receptor (EGFR), solute carrier family 2 member 1 (SLC2A1), insulin-like growth factor 1 (IGF1), mitogen-activated protein kinase 1 (MAPK1), peroxisome proliferator activated receptor alpha (PPARA) and peroxisome proliferator activated receptor gamma (PPAR-γ, PPARG). Molecular docking showed that ISL had high binding affinity with these key targets. The experimental results revealed that ISL decreased extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and increased the expression of PPAR-γ, and suppressed the production of proinflammatory mediators. Our work revealed that ISL might be an effective treatment strategy in the treatment of AD by its anti-inflammatory effect towards microglia through the ERK/PPAR-γ pathway.

BRD9 promotes the malignant phenotype of thyroid cancer by activating the MAPK/ERK pathway

Thyroid cancer is one of the most common endocrine gland malignancies in China. During gene transcription, the bromodomain and extraterminal domain (BET) proteins perform epigenome interpretation tasks. Bromodomain-containing protein 9 (BRD9) is one of the BET family members. Increasing evidence has implicated that BRD9 plays significant roles in multiple malignancies. However, its role in thyroid cancer is still not fully understood. In this research, our results demonstrated that high expression of BRD9 can facilitate the malignant phenotype of thyroid cancer cell lines, while low expression of BRD9 can impede the malignant phenotype of thyroid cancer cell lines. Pharmacologically, I-BRD9 treatment inhibits the proliferation and promotes the rate of apoptosis in thyroid cancer cell lines. Moreover, our results also revealed that BRD9 promoted xenograft tumor growth. In addition, our study showed that the expression of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinase (ERK) pathway-related proteins was decreased in BRD9 knockdown thyroid cancer cells, such as Raf, ERK, p-ERK, c-Fos, and c-Myc, which could be significantly reversed by overexpressing the BRD9 in different thyroid cancer cells. After the specific inhibitor of ERK (SCH772984) was applied to thyroid cancer cells (BCPAP cells) overexpressing the BRD9 gene, the results suggested that SCH772984 reverses the high expression of MAPK/ERK pathway-associated protein in BCPAP cells (over-expression BRD9 cells). In conclusion, this study demonstrated that BRD9 was highly expressed in serum and malignant tumor tissues of thyroid cancer patients and further promoted the development of the malignant phenotype of thyroid cancer by activating the MAPK/ERK signaling pathway.

Clioquinol inhibits angiogenesis by promoting VEGFR2 degradation and synergizes with AKT inhibition to suppress triple-negative breast cancer vascularization

Inhibition of angiogenesis, either as monotherapy or in conjunction with other treatments, holds significant promise in cancer treatment. However, the limited efficacy of clinically approved anti-angiogenic agents underscores the urgent need for the development of novel drugs and therapeutic strategies. In this study, we demonstrate the highly selective inhibitory effects of clioquinol, a topical antifungal and antibiotic agent, on the angiogenic activity of endothelial cells (ECs) in a series of in vitro angiogenesis assays. Moreover, clioquinol effectively suppressed blood vessel formation in ex vivo aortic ring and in vivo Matrigel plug assays. Mechanistic studies revealed that clioquinol directly binds to the ATP-binding site of vascular endothelial growth factor receptor 2 (VEGFR2), promoting its degradation through both proteasome and lysosome pathways. This led to the down-regulation of the downstream extracellular signal-regulated kinase (ERK) pathway. In addition, the combination with the AKT inhibitor MK-2206 synergistically boosted the anti-angiogenic efficacy of clioquinol in vitro and in an in vivo dorsal skinfold chamber model of triple-negative breast cancer (TNBC), leading to the suppression of TNBC growth. Accordingly, clioquinol, either alone or in combination with AKT inhibitors, represents a promising therapeutic agent for future anti-angiogenic cancer treatment.

Repurposing bosentan as an anticancer agent: EGFR/ERK/c-Jun modulation inhibits NSCLC tumor growth.

Drug repurposing of well-established drugs to be targeted against lung cancer has been a promising strategy. Bosentan is an endothelin 1 (ET-1) blocker widely used in pulmonary hypertension. The current experiment intends to inspect the anticancer and antiangiogenic mechanism of bosentan targeting epidermal growth factor receptor (EGFR) /extra-cellular Signal Regulated Kinase (ERK) /c-Jun/vascular endothelial growth factor (VEGF) carcinogenic pathway. BALB/c mice were randomized into four groups, the first received the vehicle, the second received 100 mg/kg oral bosentan alone, the third has non-small cell lung cancer (NSCLC) induced by two doses of 1.5g/kg urethane i.p. and finally the fourth has NSCLC received bosentan. To determine the anti-proliferative impact of bosentan, cytokeratin 19 fragments (CYFRA 21-1) level was assessed, and Ki-67 positive cells were counted by immunohistochemical (IHC). Molecular expression of EGFR via IHC, relative expression of p-ERK1/2 and p-c-Jun via western blotting and caspase 3, Bcl-2 Associated X-protein (BAX)/B-cell lymphoma 2 (Bcl-2) ratio and VEGF via ELISA were quantified. Bosentan showed pronounced improvement in lung index and histopathological examinations. Bosentan exerted a noticeable arrest of lung cancer growth indicated by the attenuation of CYFRA 21-1 and Ki-67 positive cell counts besides the boost of BAX/Bcl-2 ratio and caspase 3. Bosentan induced a remarkable decline of EGFR, T-ERK1/2/p-ERK1/2, T-c-Jun/p-c-Jun, and VEGF. Bosentan induced cytotoxic and anti-angiogenic impact through regulation of EGFR/ERK/c-Jun/VEGF axis suggesting its potential therapeutic impact against lung cancer.

β-Elemene inhibits epithelial-mesenchymal transformation in non-small cell lung cancer by targeting ALDH3B2/RPSA axis.

The pharmacological mechanism of β-elemene in non-small cell lung cancer (NSCLC) remains poorly understood. In this study, we identified aldehyde dehydrogenase 3B2 (ALDH3B2) as a pivotal target for β-elemene's anti-tumor effects in NSCLC by bioinformatic analysis. The overexpression of ALDH3B2 is specifically associated with the malignancy of NSCLC and the poor prognosis in patients with lung adenocarcinoma. Furthermore, we observed a positive correlation between ALDH3B2 levels and the sensitivity of cells to β-elemene. Additionally, we confirmed that β-elemene suppresses ALDH3B2 expression in PC-9 and NCI-H1373 cell lines. Notably, ALDH3B2 overexpression in NCI-H1373 cells resulted in enhanced migration, invasion, and a prominent epithelial-mesenchymal transition (EMT), which could be attenuated by β-elemene via inhibition of ALDH3B2 expression. Subsequent investigations demonstrated that ALDH3B2 overexpression upregulated ribosomal protein SA (RPSA) expression. β-elemene counteracted the upregulation of RPSA by suppressing ALDH3B2. Furthermore, knocking down of ALDH3B2 and β-elemene treatment significantly reduced the activation of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) signaling pathways via suppression of RPSA. In summary, our research uncovers that in NSCLC, ALDH3B2 functions as an oncogenic protein, promoting tumor progression. Meanwhile, β-elemene inhibits EMT of NSCLC by inhibition of ALDH3B2/RPSA axis and subsequently downregulating AKT and ERK signaling pathways. Our study highlights the significant role of ALDH3B2 in the progression of NSCLC, signifying it as a potential pharmacodynamic biomarker for β-elemene. These findings enrich the understanding of anti-tumor pharmacological mechanism of β-elemene, and provides new theoretical and experimental foundations for its potential application in the treatment of NSCLC.

ERK phosphorylates ESRRB to regulate the self-renewal and differentiation of mouse embryonic stem cells.

MEK (mitogen-activated protein kinase) inhibitor is widely used for culturing pluripotent stem cells, while prolonged MEK inhibition compromises the developmental potential of mouse embryonic stem cells (ESCs), implying a dual role of MEK/ERK (extracellular signal-regulated kinase) signaling in pluripotency maintenance. To better understand the mechanism of MEK/ERK in pluripotency maintenance, we performed quantitative phosphoproteomic analysis and identified 169 ERK substrates, which are enriched for proteins involved in stem cell population maintenance, embryonic development, and mitotic cell cycle. Next, we demonstrated that ERK phosphorylates a well-known pluripotency factor ESRRB on Serine 42 and 43. Dephosphorylation of ESRRB facilitates its binding to pluripotency genes, thus enhancing its activity to maintain pluripotency. In contrast, phosphorylation of ESRRB increases its binding to extraembryonic endoderm (XEN) genes, consequently promoting XEN differentiation of ESCs. Altogether, our study reveals that ERK may regulate ESC self-renewal and differentiation by phosphorylating multiple substrates, including ESRRB, which affects both ESC self-renewal and XEN differentiation.

Signaling pathways of pro-IL-1β production induced by mechanical stress in gingival epithelial cells.

Mechanical stress on the teeth and alveolar bone caused by bruxism, orthodontics, and implants affects the periodontal tissues, causing gingival recession and alveolar bone resorption, and entire body, including the heart and vascular system. Although the same forces exerted on the alveolar bone and teeth are exerted on gingival epithelial cells, little is known about the effects of mechanical stress on these cells. This study investigated the effects of mechanical stress on gingival epithelial cells. Ca9-22 cells (human gingival epithelial cells) were used. They were seeded onto the silicone and stretched cyclically. Mechanical stress-stimulated Ca9-22 cells were evaluated for pro-inflammatory interleukin (pro-IL)-1β production using Western blotting and analyzed to assess the phosphorylation level of intracellular signaling molecules. Mechanical stress induced pro-IL-1β upregulation in Ca9-22 cells, which was significantly inhibited by ruthenium red. Ruthenium red significantly inhibited mechanical stress-induced phosphorylation of focal adhesion kinase (FAK), P130Cas, and extracellular signal-regulated kinase 1 and 2 (ERK1/2) induced by mechanical stress. Additionally, Y15 significantly inhibited the upregulation of pro-IL-1β expression and phosphorylation of FAK, P130Cas, and ERK1/2 stimulated by mechanical stress. In Ca9-22 cells, mechanical stress may increase pro-IL-1β production via mechanosensitive ion channels and FAK. These findings revealed the mechanisms of inflammation in mechanically-stressed Ca9-22 cells and may aid in the development of therapeutic approaches to prevent bone resorption.

Influence of the ERK/CHGB pathway in breast cancer progression under chronic stress.

Breast cancer is one of the most common malignancies among women, and its development involves a variety of complex molecular mechanisms. Extracellular signal-regulated kinase (ERK) and Chromogranin B (CHGB) are known to play key roles in various cancers. This study aims to explore the impact of the ERK/CHGB pathway in a chronic stress environment simulated by salbutamol on the development of breast cancer. This study utilized female BALB/c mice to establish a breast cancer model, dividing them into control, salbutamol-treated, and salbutamol-inhibitor-treated groups. Cell culture, immunohistochemistry, Western Blot, real-time fluorescent quantitative PCR, and Transwell migration assays were employed to assess the effects of salbutamol and the ERK/CHGB pathway. Salbutamol treatment significantly enhanced the proliferation, migration, and invasiveness of breast cancer cells, associated with the activation of the ERK pathway and the inhibition of CHGB. The salbutamol-inhibitor-treated group exhibited a marked suppression of these effects. Additionally, the interaction of the ERK/CHGB pathway in an extracellular stress environment provided advantages for the survival and proliferation of breast cancer cells. This study demonstrates that a chronic stress environment simulated by salbutamol can promote malignant behaviors in breast cancer cells through the ERK/CHGB pathway. These findings offer new molecular targets for breast cancer treatment and highlight the potential importance of managing chronic stress and blocking specific molecular pathways in cancer therapy.

Dab1 expression level controls Reelin-induced PI3K-Akt activation in early GABAergic neurons.

Disabled-1 (Dab1) is a key regulator of the Reelin signaling cascades and controls many neurodevelopmental processes, including pyramidal neuron migration, dendrite growth, and spine formation. Dab1 is phosphorylated upon the binding of Reelin to Very low density lipoprotein receptor (VLDLR) and Apolipoprotein E receptor 2 (ApoER2) receptors, resulting in activation of a series of downstream signaling pathways, including Phosphoinositide 3-kinase (PI3K)/Akt, Lissencephaly 1 (Lis1), Crks/C3G, and Extracellular signal-regulated kinase 1/2 (Erk1/2). Dab1 is then rapidly degraded via the proteasome pathway. In humans, REELIN and DAB1 are genetically associated with several psychiatric disorders, such as schizophrenia and autism spectrum disorder. Although a subset of GABAergic neurons express Reelin and are continuously exposed to Reelin from early developmental stages through adulthood, most studies have only investigated the role of Reelin in the development and function of pyramidal neurons; as such the role of Reelin in GABAergic neurons remains poorly understood. In this study, we isolated primary neurons from mouse medial ganglionic eminence (MGE) at embryonic day 14.5 that 98-99% were composed of GABAergic neurons. Using MGE-isolated GABAergic neurons, we studied the quantitative differences in Reelin signaling and expression of related genes in these neurons for the first time. Reelin supplementation did not activate PI3K-Akt signaling in most GABAergic neurons, but it did activate the signaling pathway in Somatostatin-positive GABAergic neurons. Dab1 was transcriptionally repressed in early GABAergic neurons, demonstrating the selective activation of Reelin signaling between subsets of neurons. This study provides quantitative evidence and contributes insights into the molecular mechanisms underlying the limited effects of Reelin on Dab1-related developmental activities in the majority of GABAergic neurons during brain development.

Role of 11β-hydroxysteroid dehydrogenase type 1 inhibition in the antiobesity effect of J2H-1702 on adipocytes and a high-fat diet-induced NASH model.

Obesity due to excessive body fat accumulation remains a global problem. Patients with obesity have high cortisol levels, and its dysregulation is caused by increased 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) levels. The effects and mechanism of J2H-1702, an 11β-HSD1 inhibitor, on nonalcoholic steatohepatitis (NASH) were explored. This study compared the antiadipogenic effects of J2H-1702, elafibranor (PPARα/δ agonist), and BVT14225 (selective 11β-HSD1 inhibitor) using mouse 3T3-L1 pre-adipocytes. J2H-1702, elafibranor, and BVT14225 inhibited adipocyte differentiation and intracellular lipid accumulation in 3T3-L1 cells by downregulating phospho-extracellular signal-regulated kinase, extracellular signal-regulated kinase, phospho-c-Jun-N-terminal Kinase, c-Jun-N-terminal Kinase, phospho-P38 (P-P38), P38, CCAAT/enhancer-binding proteins alpha and β, peroxisome proliferator-activated receptor γ, and glucocorticoid receptor. Additionally, J2H-1702, elafibranor, and BVT14225 treatments effectively inhibited 11β-HSD1 activity, as revealed by cortisol concentrations, and inhibited cortisone-induced adipocyte differentiation and intracellular lipid accumulation in 3T3-L1 cells. These effects were associated with 11β-HSD1 protein inhibition. Furthermore, J2H-1702 and BVT14225 increased the expression of Akt and phosphoinositide 3-kinase involved in insulin resistance in 3T3L-1 adipocytes. In the LX-2 human hepatic stellate cell line, the relative expression of N-cadherin, 11β-HSD1, collagen1α (COLA1), α-actin of smooth muscle (α-SMA) genes in LX-2 activated with TGF-β increased significantly, and after treatment with J2H-1702, it was significantly reduced. The expression of E-cadherin is decreased in TGF-β-treated LX-2 cells and increased after treatment with J2H-1702. We tested the potential of J2H-1702 as a therapeutic agent for NASH using a high-fat diet-induced NASH model, with obeticholic acid, an FXR agonist, and elafibranor as reference drugs. All drugs significantly decreased the elevated triglyceride levels in the livers of high-fat, high-carbohydrate (HFHC-fed mice. The results may add to the benefits of targeting 11β-HSD1 inhibitors with antiadipogenic activity in developing a therapeutic agent for obesity treatment.

RBM47 as a potential therapeutic target for thyroid-associated ophthalmopathy.

RNA-binding motif 47 (RBM47) is a recently identified RNA-binding protein involved in early vertebrate development, immune homeostasis, and cancer development. This study examined the biological functions of RBM47 in thyroid-associated ophthalmopathy (TAO). Orbital fibroblasts (OFs) were obtained from the control (n=6) and TAO groups (n=6). Protein and gene expression in the obtained samples were investigated using immunohistochemistry, western blotting (WB), and RT-PCR. OFs with RBM47 knockdown were established using small interfering RNA. Subsequently, Oil Red O staining, WB, and RT-PCR were performed to assess adipogenesis in the OFs. The IL-1β-induced expression of proinflammatory molecules and hyaluronan (HA) was determined using enzyme-linked immunosorbent assay and RT-PCR. Moreover, TGF-β-induced fibrosis was evaluated using scratch assays, RT-PCR, and WB. RBM47 expression was markedly increased in orbital tissues and OFs obtained from individuals with TAO. RBM47 knockdown decreased adipogenesis and fibrosis in OFs, and downregulated the levels of insulin-like growth factor 1 receptor (IGF-1R), proinflammatory molecules, and HA. Furthermore, low RBM47 expression downregulated IGF-1R, which subsequently inhibited adipocyte differentiation by decreasing extracellular signal-regulated kinase signalling. These findings indicate that RBM47 may be involved in the regulation of adipogenesis, inflammation, HA production, and fibrosis, highlighting its potential of RBM47 as a therapeutic target for TAO.

Ferroptosis- and stemness inhibition-mediated therapeutic potency of ferrous oxide nanoparticles-diethyldithiocarbamate using a co-spheroid 3D model of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high mortality rate and exhibits a limited response to apoptosis-dependent chemotherapeutic drugs (e.g., gemcitabine, Gem). This is mainly attributed to the antioxidant defense system (glutathione and aldehyde dehydrogenase (ALDH) 1A1), which sustains stemness features of cancer stem cells (CSCs) and activated pancreatic stellate cells (PSCs)-generated excess stromal proteins. This dense stroma retards drug delivery. This study established co-spheroid model consisting of mouse PDAC cell line (KPC) and PSCs (1:5) to accurately investigate the anti-PDAC activity of nanocomplex of ferrous oxide nanoparticles-diethyldithiocarbamate (FeO NPs-DE), compared to Gem, using in vitro and in vivo 3D models. In vitro and in vivo co-spheroid models demonstrated higher therapeutic efficacy of FeO NPs-DE than Gem. FeO NPs-DE induced selective accumulation of iron-dependent ferroptosis (non-apoptosis)-generated a lethal lipid peroxidation that was potentiated by DE-mediated glutathione and ALDH1A1 suppression. This led to collapse of stemness, as evidenced by down-regulating CSC genes and p-AKT protein expression. Subsequently, gene and/or protein levels of PSC activators (transforming growth factor (TGF)-β, plasminogen activator inhibitor-1, ZEB1, and phosphorylated extracellular signal-regulated kinase) and stromal proteins (collagen 1A2, smooth muscle actin, fibronectin, and matrix metalloproteinase-9) were suppressed. Moreover, DE of nanocomplex enhanced caspase 3-dependent apoptosis with diminishing the main oncogene, BCL-2. FeO NPs-DE had a stronger eradicating effect than Gem on primary and metastatic peritoneal PDAC tumors. This nanocomplex-mediated ferroptosis and stemness inhibition provides an effective therapeutic approach for PDAC.

Dihydrotanshinone I enhanced BRAF mutant melanoma treatment efficacy by inhibiting the STAT3/SOX2 signaling pathway

BackgroundThe Food and Drug Administration has approved the Serine/threonine-protein kinase B-raf (BRAF) inhibitor and Mitogen-activated extracellular signal-regulated kinase (MEK) inhibitor combo as the first-line treatment for individuals with metastatic melanoma, although the majority of these patients exhibit primary or secondary drug resistance in the clinic. Dihydrotanshinone I (DHT) is a lipophilic compound extracted from the root of Salvia miltiorrhiza that has been linked to multiple antitumor activities. In this study, we investigated the effect of dihydrotanshinone I on the MAPK pathway inhibitor resistance of BRAF mutant malignant melanoma.MethodAfter treating A375, A375R, and A2058 cells with DHT or a combination of DHT and BRAF/MEK inhibitors, WB and Real-Time RT-qPCR were used to confirm the activation of the MAPK and STAT3/SOX2 pathways. CCK-8 was used to assess cell viability, while flow cytometry was used to identify apoptosis. In addition, mice were inoculated with A375 cells to establish a model of tumour formation, and various drug groups and treatment models were utilized. The diameter and weight of tumours in each group were then measured, and IHC and HE staining were used to assess the expression of two pathways and cytotoxicity, respectively.ResultsThis study found that DHT directly interacts with STAT3 protein and it can stop the feedback activation of the STAT3/SOX2 pathway caused by the use of MAPK pathway inhibitors. In addition, the combination of DHT and BRAF/MEK inhibitors can inhibit the proliferation and growth of BRAF mutant melanoma cells and primary and secondary drug-resistant cells. Finally, we proved that the combined therapy of DHT and BRAF/MEK inhibitors is reliable and effective at animal and cell levels.ConclusionIn BRAF mutant melanoma cells, DHT suppresses the STAT3/SOX2 signaling pathway. Combining DHT, BRAF inhibitors, and MEK inhibitors can help treat treatment-resistant BRAF mutant melanoma cells. Experimental results both in vitro and in vivo have shown that the combination of DHT and an inhibitor of the MAPK pathway is safer and more successful than using an inhibitor of the MAPK pathway alone when treating BRAF mutant melanoma.

Characterization of multiple binding sites on microtubule associated protein 2c recognized by dimeric and monomeric 14-3-3ζ.

Microtubule associated protein 2 (MAP2) interacts with the regulatory protein 14-3-3ζ in a cAMP-dependent protein kinase (PKA) phosphorylation dependent manner. Using selective phosphorylation, calorimetry, nuclear magnetic resonance, chemical crosslinking, and X-ray crystallography, we characterized interactions of 14-3-3ζ with various binding regions of MAP2c. Although PKA phosphorylation increases the affinity of MAP2c for 14-3-3ζ in the proline rich region and C-terminal domain, unphosphorylated MAP2c also binds the dimeric 14-3-3ζ via its microtubule binding domain and variable central domain. Monomerization of 14-3-3ζ leads to the loss of affinity for the unphosphorylated residues. In neuroblastoma cell extract, MAP2c is heavily phosphorylated by PKA and the proline kinase ERK2. Although 14-3-3ζ dimer or monomer do not interact with the residues phosphorylated by ERK2, ERK2 phosphorylation of MAP2c in the C-terminal domain reduces the binding of MAP2c to both oligomeric variants of 14-3-3ζ.

Apigenin exhibits memory enhancing activity through the restoration of oxido-endocrine balance and upregulation of BDNF/ERK/CREB signalling pathways in stressed mice.

Stress is linked to oxidative imbalance, neuroendocrine system malfunction, and cognitive dysfunction. It is a recognized cause of neuropsychiatric diseases. Natural flavonoid apigenin (API) has neuroprotective and antidepressant properties, but little is known about its potential in restoring memory function under stress-related circumstances. This study investigated the potentials of API administration in abrogating chronic unpredictable mild stress (CUMS)-induced cognitive impairment, including exploring its probable underlying mechanisms in mice. Male mice (n = 10) were treated with API (12.5-25mg/kg, intraperitoneally) 30min before exposure to CUMS daily for 14days. Memory function (Y-maze and novel object recognition test (NOR)) was assessed. Concentrations of malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), were estimated using a spectrophotometer. Corticosterone levels were assessed using an enzyme-linked immunosorbent assay (ELISA). Expressions of brain derived neurotrophic factor (BDNF), phosphorylated extracellular signal-regulated kinase (ERK), and cAMP response element-binding protein (CREB) were assessed using immunohistochemistry. In addition to elevating serum corticosterone and MDA levels, CUMS caused cognitive impairment in mice and decreased GSH, SOD, BDNF, ERK and CREB levels in the prefrontal cortex (PFC) and hippocampus. Administering API restored cognitive function, decreased serum corticosterone and MDA levels, as well as elevated GSH, SOD, BDNF, ERK and CREB levels in the mice brain. The restoration of oxidative, neuroendocrine balance, including upregulating BDNF, CREB, and pERK levels in the brain, all contributed to the neuroprotective effects of API. This suggests that, as shown by the stress paradigm, API may be a promising therapeutic agent for cognitive deficits.

Pinocembrin alleviates renal ischemia-reperfusion injury/unilateral ureteral obstruction (UUO)-generated renal fibrosis by targeting the CYP1B1/ROS/MAPK axis.

In our research, we constructed models of renal ischemia-reperfusion (I/R)-exposed acute kidney injury (AKI) and unilateral ureteral obstruction (UUO)-stimulated renal fibrosis (RF) in C57BL/6 mice and HK-2 cells. We firstly authenticated that oral pinocembrin (PIN) administration obviously mitigated tissue damage and renal dysfunction induced by I/R injury, and PIN attenuated UUO-caused RF, as confirmed by the reduced expression of fibrotic markers as well as hematoxylin-eosin (H&E), Sirius red, immunohistochemistry, and Masson staining. Meanwhile, the beneficial role of PIN was again demonstrated in HK-2 cells with hypoxia-reoxygenation (H/R) or transforming growth factor beta-1 (TGF-β1) treatment. Importantly, the "ingredient-target-pathway-disease" network was established through bioinformatics analysis and molecular docking, which showed that PIN may target cytochrome P450 1B1 (CYP1B1) and modulate the mitogen-activated protein kinase (MAPK) pathway to exert its impact during injury. Furthermore, experiments confirmed that PIN usage remarkably constrained CYP1B1 expression, reactive oxygen species (ROS) production, MAPK-pathway-associated inflammation, or apoptosis during I/R injury or UUO exposure. PIN also ameliorated the elevated protein phosphorylation of MAPK pathway components [p38, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase 1 (JNK ERK and JNK)], which validated the PIN-induced inhibition of the MAPK signaling pathway in renal I/R or UUO injury. Moreover, the AAV9 (adeno-associated virus 9)-packed CYP1B1 or pcDNA-CYP1B1 overexpression plasmid was utilized to treat C57BL/6 mice or HK-2 cells to overexpress CYP1B1, respectively. Notably, CYP1B1 overexpression considerably abolished PIN's restriction impact on ROS generation and MAPK pathway activation. In conclusion, via bioinformatics analysis, molecular docking, animal model, and cellular experiments, we proved that PIN alleviates renal I/R injury/UUO-generated renal fibrosis through regulating the CYP1B1/ROS/MAPK axis.

Evaluation of developmental toxicity of chlorpyrifos through new approach methodologies: a systematic review.

Chlorpyrifos (CPF) is an organophosphorus pesticide of concern because many in vivo animal studies have demonstrated developmental toxicity exerted by this substance; however, despite its widespread use, evidence from epidemiological studies is still limited. In this study, we have collected all the information generated in the twenty-first century on the developmental toxicity of CPF using new approach methodologies. We have critically evaluated and integrated information coming from 70 papers considering human, rodent, avian and fish models. The comparison of the collected evidence with available adverse outcome pathways allows us to conclude that adverse outcomes observed in animals, such as memory and learning impairments as well as reduction in cognitive function, could involve several mechanisms of action including inhibition of acetylcholinesterase, overactivation of glutamate receptors and activation of mitogen-activated protein kinase, extracellular signal-regulated kinase 1/2, followed by both disruption of neurotransmitter release and increase in oxidative stress and apoptosis.

Latest Advancements in the Management of H3K27M-Mutant Diffuse Intrinsic Pontine Glioma: A Narrative Review

Despite recent advancements in radiotherapy for Diffuse Intrinsic Pontine Glioma (DIPG), the prognosis of this disease remains poor, highlighting the need for new treatment strategies to improve outcomes. Adding stereotactic biopsy to the diagnostic process for children with DIPG has been crucial in improving the management of this disease. Indeed, the discovery of the H3K27M mutation as a key driver of DIPG has led to the development of new drugs that are more effective than traditional ones. These include nimotuzumab (an anti-EGFR drug) and vinorelbine (a semisynthetic vinca alkaloid) in combination, Panobinostat (a histone deacetylase inhibitor), ONC201 (a drug that blocks the dopamine receptor D2 and inactivates Akt and ERK kinases), and chimeric antigen receptor (CAR) T cells. In terms of local therapy, identifying the H3K27M mutation can help us explore how genetic changes affect treatment response, recurrence patterns, and survival. Beyond the time to first recurrence, specific patterns of tumor recurrence, like leptomeningeal spread, can influence treatment plans. For example, radiotherapy can be adjusted in terms of doses and volumes, based on tumor aggressiveness. Because the H3K27M mutation is linked to higher malignancy, a slightly higher dose could be used for the second round of local irradiation. Additionally, irradiating the entire craniospinal axis could help control both local and leptomeningeal disease.

Memory Decline and Aberration of Synaptic Proteins in X-Linked Moesin Knockout Male Mice.

This study aims to investigate may moesin deficiency resulted in neurodevelopmental abnormalities caused by negative impact on synaptic signaling ultimately leading to synaptic structure and plasticity. Behavioral assessments measured neurodevelopment (surface righting, negative geotaxis, cliff avoidance), anxiety (open field test, elevated plus maze test), and memory (passive avoidance test, Y-maze test) in moesin-knockout mice (KO) compared to wild-type mice (WT). Whole exome sequencing (WES) of brain (KO vs. WT) and analysis of synaptic proteins were performed to determine the disruption of signal pathways downstream of moesin. Risperidone, a therapeutic agent, was utilized to reverse the neurodevelopmental aberrance in moesin KO. Moesin-KO pups exhibited decrease in the surface righting ability on postnatal day 7 (p<0.05) and increase in time spent in the closed arms (p<0.01), showing increased anxiety-like behavior. WES revealed mutations in pathway aberration in neuron projection, actin filament-based processes, and neuronal migration in KO. Decreased cell viability (p<0.001) and expression of soluble NSF adapter protein 25 (SNAP25) (p<0.001) and postsynaptic density protein 95 (PSD95) (p<0.01) was observed in days in vitro 7 neurons. Downregulation of synaptic proteins, and altered phosphorylation levels of Synapsin I, mammalian uncoordinated 18 (MUNC18), extracellular signal-regulated kinase (ERK), and cAMP response element-binding protein (CREB) was observed in KO cortex and hippocampus. Risperidone reversed the memory impairment in the passive avoidance test and the spontaneous alternation percentage in the Y maze test. Risperidone also restored the reduced expression of PSD95 (p<0.01) and the phosphorylation of Synapsin at Ser605 (p<0.05) and Ser549 (p<0.001) in the cortex of moesin-KO. Moesin deficiency leads to neurodevelopmental delay and memory decline, which may be caused through altered regulation in synaptic proteins and function.