Nerve Growth Factor Stimulation Research Articles

Heart Failure Post-Myocardial Infarction Promotes Mammary Tumor Growth Through the NGF-TRKA Pathway

BackgroundEpidemiological investigations suggest that patients with heart failure have a higher incidence of cancer; however, the causal role of cardiac disease on cancer progression remains unclear. ObjectivesThis study aimed to investigate the impact and underlying mechanisms of myocardial infarction (MI)–induced heart failure on tumor cell growth. MethodsWe generated a syngeneic mouse model by implanting mammary tumor–derived 4T1 cells into BALB/c mice with MI resulting from ligation of the left anterior descending artery. ResultsMice with MI exhibited increased tumor volume, tumor weight, and Ki67-positive proliferative cells in the tumor tissue compared with the sham-operated mice. Furthermore, RNA sequencing analysis in the tumor tissue revealed significant enrichment of pathways related to tumor progression, particularly the PI3K-AKT pathway in the MI mice. Upregulation of tropomyosin receptor kinase A (TRKA) phosphorylation, an upstream regulator of PI3K-AKT signaling, was observed in the tumor tissue of the MI mice. We also observed elevated levels of circulating nerve growth factor (NGF), a ligand of TRKA, and increased NGF expressions in the myocardium after MI. In in vitro experiments, NGF stimulation led to increased cell proliferation, as well as phosphorylation of TRKA and AKT. Notably, inhibition of TRKA by small interfering RNA or the chemical inhibitor GW441756 effectively blocked these effects. Administration of GW441756 resulted in the suppression of tumor volume and cell proliferation in the MI mice. ConclusionsOur study demonstrates that MI promotes mammary tumor growth through the NGF-TRKA pathway. Consequently, inhibiting TRKA could represent a therapeutic strategy for breast cancer patients concurrently experiencing heart failure after MI.

Neurotrophic and Neuroprotective Effects of Hericium erinaceus

Hericium erinaceus is a valuable mushroom known for its strong bioactive properties. It shows promising potential as an excellent neuroprotective agent, capable of stimulating nerve growth factor release, regulating inflammatory processes, reducing oxidative stress, and safeguarding nerve cells from apoptosis. The active compounds in the mushroom, such as erinacines and hericenones, have been the subject of research, providing evidence of their neuroprotective effects. Further research and standardization processes for dietary supplements focused on H. erinaceus are essential to ensuring effectiveness and safety in protecting the nervous system. Advancements in isolation and characterization techniques, along with improved access to pure analytical standards, will play a critical role in achieving standardized, high-quality dietary supplements based on H. erinaceus. The aim of this study is to analyze the protective and nourishing effects of H. erinaceus on the nervous system and present the most up-to-date research findings related to this topic.

Bioactive superparamagnetic iron oxide-gold nanoparticles regulated by a dynamic magnetic field induce neuronal Ca2+ influx and differentiation

Treating neurodegenerative diseases, e.g., Alzheimer's Disease, remains a significant challenge due to the limited neuroregeneration rate in the brain. The objective of this study is to evaluate the hypothesis that external magnetic field (MF) stimulation of nerve growth factor functionalized superparamagnetic iron oxide-gold (NGF-SPIO-Au) nanoparticles (NPs) can induce Ca2+ influx, membrane depolarization, and enhance neuron differentiation with dynamic MF (DMF) outperforming static MF (SMF) regulation. We showed the that total intracellular Ca2+ influx of PC-12cells was improved by 300% and 535% by the stimulation of DMF (1 Hz, 0.5 T, 30min) with NGF-SPIO-Au NPs compared to DMF alone and SMF with NGF-SPIO-Au NPs, respectively, which was attributed to successive membrane depolarization. Cellular uptake performed with the application of sodium azide proved that DMF enhanced cellular uptake of NGF-SPIO-Au NPs via endocytosis. In addition, DMF upregulated both the neural differentiation marker (β3-tubulin) and the cell adhesive molecule (integrin-β1) with the existence of NGF-SPIO-Au NPs, while SMF did not show these effects. The results imply that noninvasive DMF-stimulated NPs can regulate intracellular Ca2+ influx and enhance neuron differentiation and neuroregeneration rate.

Vitamin D Levels and Microvascular Complications in Type 2 Diabetes Mellitus Patients: A Study from North Keral

Introduction: Vitamin D plays an important role in glucose metabolism. Several pleiotropic effects of Vitamin D have been studied like regulation of cell proliferation, suppression of cell mediated immunity, Glial cell line-derived neurotrophic factor, stimulation of nerve growth factor, suppression of Renin-angiotensin-aldosterone system (RAAS), reduction of albuminuria, immunomodulatory effects, and anti-inflammatory effects.(1)Thus, vitamin D is implicated in the pathogenesis of retinopathy, neuropathy and nephropathy.
 Materials and Methods: A Cross-sectional case-control study of 206 patients (>30 years), who met the American Diabetes Association, 2011 criteria (2) for type 2 DM, was conducted. Subjects were evaluated for the presence of microvascular complications by clinical evaluation, urine examination, fundus examination, clinical neuropathy scoring, and various biochemical tests. 25-OH cholecalciferol levels were done and cut off level for vitamin D deficiency was 30 ng/ml. 72 Vitamin D sufficient and 134 Vitamin D deficient cases were studied.
 Results: A total of 134 T2DM cases with Vitamin D deficiency were studied. 72 age matched T2DM patients with sufficient Vitamin D levels served as controls. The mean age of cases under study was 47.58 ± 9.63 years compared to 51.24 ± 8.75 years of controls. 61.2% were females, whereas 38.8% were males in the case group while in the control group, 69.4% were males, and 30.5% were females. The mean duration of diabetes in the cases studied was 57.08 ± 18.13 months. It was 52.69 ± 17.98 months in the Vitamin D sufficient controls. Significant statistical associations were established using Chi square test between Vitamin D status and development of microvascular complications like Diabetic nephropathy, retinopathy and neuropathy in Type 2 Diabetes Mellitus at p < 0.05.
 Conclusion and Implication: Vitamin D is an important factor in modifying the risk of Type 2 DM and its microvascular complications, especially Diabetic retinopathy, neuropathy and nephropathy. Administration of vitamin D supplements may prove to be a beneficial adjuvant therapy in mitigating microvascular complications. Frequent Monitoring of Vitamin D status can decrease the burden of co-morbidities in T2DM and thus can decrease the mortality rate associated with T2DM. However; the exact role of vitamin D in these processes requires further investigations.
 Keywords:
 Diabetes, Nephropathy, Neuropathy, Retinopathy, Vitamin D

Amphiphilic Cyclodextrin Nanoparticles as Delivery System for Idebenone: A Preformulation Study.

Idebenone (IDE), a synthetic short-chain analogue of coenzyme Q10, is a potent antioxidant able to prevent lipid peroxidation and stimulate nerve growth factor. Due to these properties, IDE could potentially be active towards cerebral disorders, but its poor water solubility limits its clinical application. Octanoyl-β-cyclodextrin is an amphiphilic cyclodextrin (ACyD8) bearing, on average, ten octanoyl substituents able to self-assemble in aqueous solutions, forming various typologies of supramolecular nanoassemblies. Here, we developed nanoparticles based on ACyD8 (ACyD8-NPs) for the potential intranasal administration of IDE to treat neurological disorders, such as Alzheimer's Disease. Nanoparticles were prepared using the nanoprecipitation method and were characterized for their size, zeta potential and morphology. STEM images showed spherical particles, with smooth surfaces and sizes of about 100 nm, suitable for the proposed therapeutical aim. The ACyD8-NPs effectively loaded IDE, showing a high encapsulation efficiency and drug loading percentage. To evaluate the host/guest interaction, UV-vis titration, mono- and two-dimensional NMR analyses, and molecular modeling studies were performed. IDE showed a high affinity for the ACyD8 cavity, forming a 1:1 inclusion complex with a high association constant. A biphasic and sustained release of IDE was observed from the ACyD8-NPs, and, after a burst effect of about 40%, the release was prolonged over 10 days. In vitro studies confirmed the lack of toxicity of the IDE/ACyD8-NPs on neuronal SH-SY5Y cells, and they demonstrated their antioxidant effect upon H2O2 exposure, as a general source of ROS.

Lion’s Mane (Hericium erinaceus): A Potential Treatment for Neurologic Disorders in Veterinary Medicine

The use of the culinary and medicinal mushroom Lion’s Mane (LM) (Hericium erinaceus) has been extensively researched. Much of the recent research has been fueled by interest in using LM to prevent and treat neurological diseases such as cognitive decline, dementia, Parkinson’s disease, and Alzheimer’s disease and to stimulate peripheral nerve regeneration. This mushroom is rich in physiologically important components. The main bioactive phytochemicals extracted from LM’s fruiting body and mycelia are hericenones, erinacines, polysaccharides, and dilinoleoyl-phosphatidylethanolamine (DLPE). β-glucan polysaccharides are immuno-active and responsible for LM’s anti-cancer, immunomodulating, hypo-lipidemic, antioxidant, and neuroprotective actions. The hericenones and erinacines can cross the blood-brain barrier and stimulate nerve growth factor (NGF). Since NGF keeps the brain and nervous system regenerating and repairing itself, research has been focused on the effect of these compounds on brain and nervous system conditions. In veterinary medicine, supplementation of LM has potential in the treatment of many conditions, including peripheral nerve damage, dementia, cognitive decline, anxiety, and spinal cord trauma and degeneration.

Tryptase activates enteric glial cells followed by affecting neuronal properties possibly via the stimuli-associated mediators

ObjectivesMast cell-derived tryptase causes neuronal elongation/sensitization leading to visceral hypersensitivity. However, effects of tryptase on enteric glial cells (EGCs) and subsequent interaction between EGCs and neurons remain unknown. MethodsWe evaluated proteins and mRNA expressions in EGC (CRL-2690, ATCC) after tryptase stimulation: nerve growth factor (NGF), netrin-1, and glial cell-derived neurotrophic factor (GDNF). We examined morphological changes in neurons (PC12 cells, CRL-1721.1) by co-incubation with the conditioned medium of EGCs after tryptase stimulation. ResultsEGC was activated by tryptase, and proliferated (by 1.8-fold) with cytoplasmic expansion and process elongation. Intercellular connections of EGC were more complexed. Tryptase induced mRNA expression (2.5-fold) and protein expression of NGF. Netrin-1 (3-fold) and GDNF (3-fold) mRNA expressions were increased at 30 min. Increase in netrin-1 continued until 6 h, whereas the latter decreased by 3 h. The conditioned medium of EGC after tryptase stimulation expanded neuronal cytoplasm (round or ramified shapes) and neurite outgrowth with elongation of cytoskeletal filaments in time-dependent and dose-dependent manners. These changes were similar to those after NGF stimulation. Growth cone proteins of neurons were also increased by the conditioned medium. ConclusionEGC activated by tryptase changes neuronal morphology (process elongation and cytoplasm expansion) possibly via the stimuli-associated mediators.

Abstract 10584: Nerve Growth Factor/Tropomyosin Receptor Kinase A Axis Plays a Pivotal Role in Breast Cancer Progression After Myocardial Infarction

Background: Several studies have shown that cancer incidence is increasing in patients with chronic heart failure. We have reported that nerve growth factor (NGF) plays a pivotal role in sympathetic nerve remodeling after myocardial infarction (MI). However, the impact of NGF on cancer progression in the setting of MI-induced heart failure remains to be elucidated. Methods and Results: NGF phosphorylated tropomyosin receptor kinase A (TrkA) in murine breast carcinoma 4T1 cells, and NGF increased the percentage of Ki-67 positive 4T1 cells. MI was induced by permanent ligation of the left anterior descending artery of female Balb/c mice. Then, 4T1 cells were injected into the right fourth mammary fat pad at two weeks after MI surgery. Serum levels of NGF were higher in the MI group than in the sham group at the time of 4T1 cell injection (279±107 pg/ml vs. 172±36 pg/ml, P=0.014). The size of breast cancer was significantly larger in the MI group than in the sham group at three weeks after 4T1 cell injection (451.8±137 mm 3 vs. 304.3±136 mm 3 , P=0.0014, figure). The percentage of Ki-67 positive cells in cancer tissue was higher in the MI group compared to the sham group (37.1±6.8% vs. 16.5±3.2%, P<0.001). Furthermore, membranous TrkA was more phosphorylated in the MI group than in the sham group (1.56±0.11 AU vs. 1.00±0.11 AU, P<0.001). Knockdown of TrkA with siRNA in 4T1 cells suppressed the increase of Ki-67 positive cells by NGF stimulation (51.9±1.2% vs. 24.9±3.7%, P=0.044). A TrkA inhibitor, GW441756, suppressed the NGF-induced phosphorylation of TrkA in 4T1 cells. Moreover, the percentage of Ki-67 positive cells in cancer tissue was lower in the MI mice treated with a TrkA inhibitor (10 mg/kg/week, I.P.) than in the MI mice without a TrkA inhibitor (26.3±3.6% vs. 45.6±3.7%, P<0.001). Conclusion: Increased NGF caused by MI is associated with breast cancer progression through NGF/TrkA axis.

PSXI-7 Effects of Hericium Erinaceus on Health of Aged Dogs

Abstract Hericium erinaceus is a medicinal mushroom that has beneficial effects in human anti-oxidation, immune enhancement, and nerve growth factor stimulation. Aging-related benefits have also been described. The present study investigated the effect of H. erinaceus on aged dogs, with adult (5 years old) and aged (11 years old) animals untreated as controls (C1 and C2, respectively). Aged dogs were additionally treated with 0.4 g (T1) and 0.8 g (T2) H. erinaceus per metabolic body weight. In a two-choice preference test, the experimental diet with H. erinaceus was completely consumed more rapidly. No significant change in body weight, body condition score, and feces score were evident for 16 weeks. Complete blood counts and blood chemistry analyses were in normal ranges. These findings indicated that H. erinaceus was not detrimental to the general health of dogs. Metabolome profiles in sera were determined by nuclear magnetic resonance (NMR) imaging to investigate the metabolic change in dogs fed H. erinaceus. After 8 weeks, formate, ascorbate (vitamin C), acetone and choline concentrations were significantly increased. These compounds were also significantly increased after 16 weeks in the T2 group. Formate is influential in cell proliferation, acetone and choline are involved in lipid membrane formation, and ascorbate is essential for tissue repair. Additionally, choline and ascorbate are involved in antioxidant system. Collectively, the findings indicate the benefit of H. erinaceus to increase cell proliferation and tissue repair activity that might be related to enhancing an antioxidant activity in aged dogs.

Receptor Tyrosine Kinases Mediated Cell Signalling Pathways

A small number of signalling pathways, including receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs), are activated by plasma membrane receptors in order for cells to respond to external cues. In addition to transmitting, these pathways also process, encode, and integrate both internal and external signals. In recent years, it has become clear that different spatio-temporal activation profiles of the same set of signalling proteins lead to different gene-expression patterns and various physiological responses. These findings suggest that the precise temporal control and relative spatial distribution of activated signal transducers are necessary for important cellular decisions such as cytoskeletal reorganisation, cell-cycle checkpoints, and cell death (apoptosis). Due to their crucial function in the control of embryogenesis, cell survival, motility, proliferation, differentiation, glucose metabolism, and apoptosis, RTK-mediated signalling pathways have drawn a lot of attention from scientists. A significant number of serious human diseases, including diabetes, cancer, chronic inflammatory syndromes, and developmental defects, are caused by RTK signalling dysfunction. RTKs undergo allosteric transitions (the insulin receptor, for instance) or dimerization in response to stimulation, which activates the intrinsic tyrosine-kinase activity. Numerous cytoplasmic proteins receive a biochemical signal from subsequent phosphorylation of numerous tyrosine residues on the receptor, which causes them to move to the cell surface. Through intricate biochemical circuits of protein-protein interactions and covalent modification cascades, the resulting cellular reactions take place. The earlier theories of discrete linear pathways, which connected extracellular signals to the expression of particular genes, have been replaced by an emerging picture of interconnected signalling networks, raising concerns about the specificity of signal-response events. In actuality, all RTK-mediated pathways share a common protein complement that mediates signal transduction downstream of RTKs. The expression of nuclear transcription factors is induced by the activation of kinase and phosphatase cascades, such as the mitogen-activated protein kinase (MAPK) cascades, which are both activated by GPCRs and RTKs. There is no single protein or gene that determines the specificity of a signal for any given receptor pathway. Instead, the temporal and spatial dynamics of the components of downstream signalling control specificity. A classic example is the distinctive biological response to EGF and nerve growth factor stimulation of PC12 cell lines (NGF). Cell proliferation is temporarily induced by EGF, whereas cell differentiation is temporarily triggered by sustained MAPK activation by NGF. However, there are many variables that affect how MAPK cascades behave. Depending heavily on their subcellular localization and their recruitment to scaffold proteins, MAPK cascades can produce oscillations, abrupt switches, bistable dynamics.

Direct interaction of TrkA/CD44v3 is essential for NGF-promoted aggressiveness of breast cancer cells

BackgroundCD44 is a multifunctional membrane glycoprotein. Through its heparan sulfate chain, CD44 presents growth factors to their receptors. We have shown that CD44 and Tropomyosin kinase A (TrkA) form a complex following nerve growth factor (NGF) induction. Our study aimed to understand how CD44 and TrkA interact and the consequences of inhibiting this interaction regarding the pro-tumoral effect of NGF in breast cancer.MethodsAfter determining which CD44 isoforms (variants) are involved in forming the TrkA/CD44 complex using proximity ligation assays, we investigated the molecular determinants of this interaction. By molecular modeling, we isolated the amino acids involved and confirmed their involvement using mutations. A CD44v3 mimetic peptide was then synthesized to block the TrkA/CD44v3 interaction. The effects of this peptide on the growth, migration and invasion of xenografted triple-negative breast cancer cells were assessed. Finally, we investigated the correlations between the expression of the TrkA/CD44v3 complex in tumors and histo-pronostic parameters.ResultsWe demonstrated that isoform v3 (CD44v3), but not v6, binds to TrkA in response to NGF stimulation. The final 10 amino acids of exon v3 and the TrkA H112 residue are necessary for the association of CD44v3 with TrkA. Functionally, the CD44v3 mimetic peptide impairs not only NGF-induced RhoA activation, clonogenicity, and migration/invasion of breast cancer cells in vitro but also tumor growth and metastasis in a xenograft mouse model. We also detected TrkA/CD44v3 only in cancerous cells, not in normal adjacent tissues.ConclusionCollectively, our results suggest that blocking the CD44v3/TrkA interaction can be a new therapeutic option for triple-negative breast cancers.

NGF activates NFAT via the MEK1/2 pathway in PC12 cells

Nerve growth factor (NGF) plays a key role in controlling growth, maintenance and survival of neurons as well as nociceptor development. Many of its critical actions are believed to be mediated by activation of corresponding transcription factors. Here I attempt to reveal signaling cascades that relay NGF stimulation to NFAT, a family of Ca2+/calcineurin-dependent transcription factors that are implicated in playing a pivotal role in neuronal development and survival, and pain sensation. With a luciferase gene reporter assay, it was confirmed that NGF can trigger NFAT-dependent gene expression in PC12 cells. Subsequent research with pharmacological tools uncovers that this effect was mediated by the TrkA-MEK1/2 pathway. Furthermore, it was determined that NFATc3 is the predominant isoform by calculating an absolute copy number of each NFAT isoform with quantitative PCR. Taken together, it is proposed that elucidating cellular connections linking NGF and NFAT may help reveal novel therapeutic targets, which can be exploited to devise innovative remedies for the treatment of NGF and NFAT-associated clinical disorders such as anomalous neuronal development and hyperalgesia.

Role of Mitochondria in Interplay between NGF/TRKA, miR-145 and Possible Therapeutic Strategies for Epithelial Ovarian Cancer.

Ovarian cancer is the most lethal gynecological neoplasm, and epithelial ovarian cancer (EOC) accounts for 90% of ovarian malignancies. The 5-year survival is less than 45%, and, unlike other types of cancer, the proportion of women who die from this disease has not improved in recent decades. Nerve growth factor (NGF) and tropomyosin kinase A (TRKA), its high-affinity receptor, play a crucial role in pathogenesis through cell proliferation, angiogenesis, invasion, and migration. NGF/TRKA increase their expression during the progression of EOC by upregulation of oncogenic proteins as vascular endothelial growth factor (VEGF) and c-Myc. Otherwise, the expression of most oncoproteins is regulated by microRNAs (miRs). Our laboratory group reported that the tumoral effect of NGF/TRKA depends on the regulation of miR-145 levels in EOC. Currently, mitochondria have been proposed as new therapeutic targets to activate the apoptotic pathway in the cancer cell. The mitochondria are involved in a myriad of functions as energy production, redox control, homeostasis of Ca+2, and cell death. We demonstrated that NGF stimulation produces an augment in the Bcl-2/BAX ratio, which supports the anti-apoptotic effects of NGF in EOC cells. The review aimed to discuss the role of mitochondria in the interplay between NGF/TRKA and miR-145 and possible therapeutic strategies that may decrease mortality due to EOC.

Mage-D1 binding to activated p75NTR positively regulates mineralization of rat ectomesenchymal stem cells in vitro

To detect the binding of Mage-D1 with activated p75NTR and explore their role in regulating mineralization of ectomesenchymal stem cells (EMSCs). EMSCs were isolated from the tooth germs of embryonic SD rats (19.5 days of gestation) by tissue explant culture and were identified for surface markers using flow cytometry. The cultured cells were divided into blank control group, 100 ng/mL nerve growth factor (NGF) stimulation group, and lentivirus-mediated Mage-D1 interference (SH-Mage-D1) group. Proximity ligation assay was used to detect the binding of Mage-D1 with activated p75NTR in the EMSCs, and the binding strength was compared among the 3 groups. Alizarin red staining and ALP staining were used to observe mineralization of the induced cells. The expressions of ALP, Runx2, OCN, BSP, OPN, Msx1 and Dlx1 at both the mRNA and protein levels were detected using RT-PCR and Western blotting. The isolated EMSCs expressed high levels of cell surface markers CD44, CD90, CD29, CD146, and CD105 with a low expression of CD45. The results of proximity ligation assay showed that the binding of Mage-D1 with activated p75NTR in the cells increased over time, and the binding strength was significantly greater in NFG-treated cells than in the cells in the other two groups (P < 0.05). Alizarin red staining and ALP staining of the induced cells showed that the changes in the mineralization nodules were consistent with those of ALP activity. The cells treated with 100 ng/mL NGF exhibited significantly increased expressions of ALP, Runx2, OCN, BSP, OPN, Col1, Msx1 and Dlx1 as compared with the cells in the other two groups (P < 0.05). Mage-D1 directly binds to activated p75NTR in embryonic rat EMSCs to positively regulate the mineralization of the EMSCs.

NGF Signaling Interacts With the Hippo/YAP Pathway to Regulate Cervical Cancer Progression.

Nerve growth factor (NGF) is increasingly implicated in cervical cancer progression, but its mechanism in cervical cancer is unclear. Here, studies demonstrate that NGF inhibits the Hippo signaling pathway and activates Yes-associated protein (YAP) to induce cervical cancer cell proliferation and migration. Our results suggested that stimulation of NGF promoted cell growth and migration and activated YAP in HeLa and C-33A cell lines. The expression of YAP target genes (CTGF and ANKRD1) was upregulated after NGF treatment. The NGF inhibitor Ro 08-2750 and siRNA-mediated NGF receptor gene silencing suppressed HeLa and C-33A cells proliferation and migration, activated large suppressor kinase 1 (LATS1) kinase activity, and suppressed YAP function. In addition, the expression of YAP target genes (CTGF and ANKRD1) was suppressed by Ro 08-2750 treatment in HeLa and C-33A cells. Interestingly, proliferation was significantly higher in NGF-treated cells than in control cells, and this effect was completely reversed by the YAP small molecule inhibitor-verteporfin. Furthermore, the mouse xenograft model shows that NGF regulates YAP oncogenic activity in vivo. Mechanistically, NGF stimulation inactivates LATS1 and activates YAP, and NGF inhibition was found to induce large suppressor kinase 1 (LATS1) phosphorylation. Taken together, these data provide the first direct evidence of crosstalk between the NGF signaling and Hippo cancer pathways, an interaction that affects cervical cancer progression. Our study indicates that combined targeting of the NGF signaling and the Hippo pathway represents a novel therapeutic strategy for treatment of cervical cancer.

MicroRNA-146a inhibition promotes total neurite outgrowth and suppresses cell apoptosis, inflammation, and STAT1/MYC pathway in PC12 and cortical neuron cellular Alzheimer's disease models.

This study aimed to explore the effect of microRNA (miR)-146a inhibition on regulating cell apoptosis, total neurite outgrowth, inflammation, and STAT1/MYC pathway in Alzheimer's disease (AD). PC12 and cortical neuron cellular AD models were constructed by Aβ1-42 insult. For the former model, nerve growth factor (NGF) stimulation was previously conducted. miR-146a inhibitor and negative-control (NC) inhibitor were transfected into the two cellular AD models, and then cells were named miR-inhibitor group and NC-inhibitor group, respectively. After transfection, cell apoptosis, total neurite outgrowth, supernatant inflammation cytokines, and STAT1/MYC pathway were detected. miR-146a expression was similar between PC12 cellular AD model and control cells (NGF-stimulated PC12 cells), while miR-146a expression was increased in cortical neuron cellular AD model compared with control cells (rat embryo primary cortical neurons). In both PC12 and cortical neuron cellular AD models, miR-146a expression was reduced in miR-inhibitor group compared with NC-inhibitor group after transfection. Furthermore, cell apoptosis was attenuated, while total neurite outgrowth was elevated in miR-inhibitor group compared with NC-inhibitor group. As for supernatant inflammatory cytokines, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-17 levels were lower in miR-inhibitor group than in NC-inhibitor group. Additionally, STAT1 and c-Myc mRNA and protein expressions were attenuated in miR-inhibitor group compared with NC-inhibitor group. In conclusion, miR-146a potentially represented a viable therapeutic target for AD.

Neuroprotective effects of Hericium erinaceus (Bull.: Fr.) Pers. against high-dose corticosterone-induced oxidative stress in PC-12 cells

BackgroundHericium erinaceus is a culinary and medicinal mushroom in Traditional Chinese Medicines. It has numerous pharmacological effects including immunomodulatory, anti-tumour, anti-microbial, anti-aging and stimulation of nerve growth factor (NGF) synthesis, but little is known about its potential role in negating the detrimental effects of oxidative stress in depression. The present study investigated the neuroprotective effects of H. erinaceus standardised aqueous extract (HESAE) against high-dose corticosterone-induced oxidative stress in rat pheochromocytoma (PC-12) cells, a cellular model mimicking depression.MethodsPC-12 cells was pre-treated with HESAE for 48 h followed by 400 μM corticosterone for 24 h to induce oxidative stress. Cells in complete medium without any treatment or pre-treated with 3.125 μg/mL desipramine served as the negative and positive controls, respectively. The cell viability, lactate dehydrogenase (LDH) release, endogenous antioxidant enzyme activities, aconitase activity, mitochondrial membrane potentials (MMPs), intracellular reactive oxygen species (ROS) levels and number of apoptotic nuclei were quantified. In addition, HESAE ethanol extract was separated into fractions by chromatographic methods prior to spectroscopic analysis.ResultsWe observed that PC-12 cells treated with high-dose corticosterone at 400 μM had decreased cell viability, reduced endogenous antioxidant enzyme activities, disrupted mitochondrial function, and increased oxidative stress and apoptosis. However, pre-treatment with HESAE ranging from 0.25 to 1 mg/mL had increased cell viability, decreased LDH release, enhanced endogenous antioxidant enzyme activities, restored MMP, attenuated intracellular ROS and protected from ROS-mediated apoptosis. The neuroprotective effects could be attributed to significant amounts of adenosine and herierin III isolated from HESAE.ConclusionsHESAE demonstrated neuroprotective effects against high-dose corticosterone-induced oxidative stress in an in vitro model mimicking depression. HESAE could be a potential dietary supplement to treat depression.

Pharmacologic therapy of olfaction disroders induced by COVID-19 upper respiratory infection

Postviral olfactory disorder refers to the sensorineural olfactory loss caused by upper respiratory tract infections. With the increasing awareness of olfactory or gustatory dysfunction as a potential early symptom of coronavirus disease 2019, postviral olfactory disorder has been attracting much attention. Postviral olfactory disorder is the most common type of olfactory disorder, especially among women aged over 50 years. Systemic or topical corticosteroids have commonly been used for treating this disorder, but the mechanism of corticosteroid action is unclear. Other medical treatment options such as alpha-lipoic acids and caroverine that stimulate nerve growth factor expression or prevent glutamatergic neurotoxicity have also been used. Although these drugs have been found to be useful in the treatment of postviral olfactory disorder in previous studies, the efficacy has not been statistically proven through a meta-analysis. Recently, olfactory training has been introduced in the treatment strategy for postviral olfactory disorder. It is a safe option without side effects that can be used for treating olfactory disorders caused by upper respiratory tract infections. Further rigorous studies are needed to determine the efficacy of the combination of drug treatment and olfactory training.

Transcriptional repression of PTEN in neural cells using CRISPR/dCas9 epigenetic editing

After damage to the adult mammalian central nervous system (CNS), surviving neurons have limited capacity to regenerate and restore functional connectivity. Conditional genetic deletion of PTEN results in robust CNS axon regrowth, while PTEN repression with short hairpin RNA (shRNA) improves regeneration but to a lesser extent, likely due to suboptimal PTEN mRNA knockdown using this approach. Here we employed the CRISPR/dCas9 system to repress PTEN transcription in neural cells. We targeted the PTEN proximal promoter and 5′ untranslated region with dCas9 fused to the repressor protein Krüppel-associated box (KRAB). dCas9-KRAB delivered in a lentiviral vector with one CRISPR guide RNA (gRNA) achieved potent and specific PTEN repression in human cell line models and neural cells derived from human iPSCs, and induced histone (H)3 methylation and deacetylation at the PTEN promoter. The dCas9-KRAB system outperformed a combination of four shRNAs targeting the PTEN transcript, a construct previously used in CNS injury models. The CRISPR system also worked more effectively than shRNAs for Pten repression in rat neural crest-derived PC-12 cells, and enhanced neurite outgrowth after nerve growth factor stimulation. PTEN silencing with CRISPR/dCas9 epigenetic editing may provide a new option for promoting axon regeneration and functional recovery after CNS trauma.

Role of interleukin-1β in nerve growth factor expression, neurogenesis and deep dyspareunia in endometriosis.

Does interleukin-1β (IL-1β) play a role in promoting nerve growth factor expression, neurogenesis and deep dyspareunia in endometriosis? IL-1β directly stimulates nerve growth factor (NGF) expression in endometriosis and is associated with local neurogenesis around endometriosis and more severe deep dyspareunia. Local nerve density around endometriosis (using the pan-neuronal marker PGP9.5) is associated with deep dyspareunia in endometriosis, mediated in part by NGF expression. This in vitro study included endometriotic tissue samples from 45 patients. This study was conducted in a university hospital affiliated research institute and included 45 women with surgically excised deep uterosacral/rectovaginal endometriosis (DIE, n = 12), ovarian endometriomas (OMA, n = 14) or superficial peritoneal uterosacral/cul-de-sac endometriosis (SUP, n = 19). Immunolocalisation of IL-1β, IL-1 receptor type 1 (IL-1R1), NGF and PGP9.5 in endometriotic tissues was examined by immunohistochemistry (IHC), and the intensity of IHC staining in the endometriotic epithelium and stroma was semi-quantitatively evaluated using the Histoscore method (H-score). For each case, deep dyspareunia was pre-operatively rated by the patient on an 11-point numeric rating scale (0-10). In addition, primary endometriosis stromal cells were isolated and cultured from surgically excised endometriosis. These cells were treated with IL-1β alone or in combination of Anakinra (an inhibitor of IL-1R1), small inference RNA (siRNA) against IL-1R1, siRNA against c-FOS or NGF neutralising antibody. The mRNA and protein levels of target genes (NGF and c-FOS) were assessed by reverse-transcription qPCR and western blot/ELISA, respectively. Furthermore, immunofluorescent microscopy was used to examine the neurite growth of rat pheochromocytoma PC-12 cells, as an in vitro model of neurogenesis. For IHC, IL-1β expression in the endometriosis epithelium was significantly associated with more severe deep dyspareunia (r = 0.37, P = 0.02), higher nerve fibre bundle density around endometriosis (r = 0.42, P = 0.01) and greater NGF expression by the endometriosis epithelium (r = 0.42, P = 0.01) and stroma (r = 0.45, P = 0.01). In primary endometriosis stromal cells, treatment with exogenous IL-1β significantly increased the mRNA and protein levels of NGF and c-FOS. Pre-treatment with Anakinra, siRNA against IL-1R1, or siRNA against c-FOS, each attenuated IL-1 β-induced increases of NGF expression. In addition, supernatants from IL-1β treated endometriosis stromal cells significantly stimulated PC-12 neurite growth compared to controls, and these effects could be attenuated by pre-treatment with NGF neutralising antibody or Anakinra. N/A. We did not have data from cultures of endometriosis glandular epithelium, due to the known difficulties with primary cultures of this cell type. Our study revealed a mechanism for deep dyspareunia in endometriosis, whereby IL-1β stimulates NGF expression, promoting local neurogenesis around endometriosis, which in turn leads to tender pelvic anatomic sites and thus deep-hitting dyspareunia. There may also be potential for drug targeting of IL-1β and/or NGF in the management of endometriosis-associated pain. This study was funded by grants from the Canadian Institutes of Health Research (MOP-142273 and PJT-156084). P.Y. is also supported by a Health Professional Investigator Award from the Michael Smith Foundation for Health Research. MB has financial affiliations with Abbvie and Allergan. Otherwise, there are no conflicts of interest to declare.