The effects of Chinese medicines on cAMP/PKA signaling in central nervous system dysfunction

Serum exosomal microRNAs as potential biomarkers for centrally mediated abdominal pain syndrome

Centrally mediated abdominal pain syndrome (CAPS) has generated a heavy disease burden worldwide. This study aimed to explore the serum exosomal microRNAs as potential diagnostic biomarkers for CAPS. From September 2022 to October 2023, 97 patients with CAPS and 96 healthy subjects were enrolled. Differentially expressed serum exosomal miRNAs between patients with CAPS and healthy controls were identified by high-throughput sequencing and quantitative real-time polymerase chain reaction (qRT-PCR). The Receiver Operating Characteristic (ROC) curves and multivariate logistic regression analysis were used to evaluate the diagnostic value of the serum exosomal miRNAs. MiR-6850-5p, miR-194-5p, miR-199a-3p, miR-4525 which were significantly downregulated in serum exomes of CAPS patients compared to healthy controls which yielded the AUC values of 0.914 (95% CI, 0.873-0.954), 0.767 (95% CI, 0.695-0.839), 0.617 (95% CI, 0.527-0.708) and 0.561 (95% CI, 0.465-0.656), respectively to distinguish CAPS patients from healthy subjects. And AUC of the integration of the above 4 miRNAs was 0.931 (95% CI, 0.896-0.966). Multivariate logistic regression indicated that hsa-miR-6850-5p (OR=0.046; p<0.001), anxiety (OR=7.670; p=0.025) and depression (OR=22.967; p=0.008) were the independent predictors of CAPS. Serum exosomal miR-6850-5p is a promising diagnostic biomarker for CAPS. PERSPECTIVE: This study may be the first to explore serum exosomal miRNAs as a new diagnostic biomarker for CAPS, and the findings may help clinicians to access comprehensive understanding and accurate diagnosis of CAPS.

Transcriptomic and bioinformatics analysis of the mechanism by which erythropoietin promotes recovery from traumatic brain injury in mice

Recent studies have found that erythropoietin promotes the recovery of neurological function after traumatic brain injury. However, the precise mechanism of action remains unclear. In this study, we induced moderate traumatic brain injury in mice by intraperitoneal injection of erythropoietin for 3 consecutive days. RNA sequencing detected a total of 4065 differentially expressed RNAs, including 1059 mRNAs, 92 microRNAs, 799 long non-coding RNAs, and 2115 circular RNAs. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses revealed that the coding and non-coding RNAs that were differentially expressed after traumatic brain injury and treatment with erythropoietin play roles in the axon guidance pathway, Wnt pathway, and MAPK pathway. Constructing competing endogenous RNA networks showed that regulatory relationship between the differentially expressed non-coding RNAs and mRNAs. Because the axon guidance pathway was repeatedly enriched, the expression of Wnt5a and Ephb6, key factors in the axonal guidance pathway, was assessed. Ephb6 expression decreased and Wnt5a expression increased after traumatic brain injury, and these effects were reversed by treatment with erythropoietin. These findings suggest that erythropoietin can promote recovery of nerve function after traumatic brain injury through the axon guidance pathway.

Magnetic manipulation of Fe3O4@BaTiO3 nanochains to regulate extracellular topographical and electrical cues

Magnetic fields play an essential role in material science and biomedical engineering. Magnetic-responsive materials can be arranged orderly in matrix to realize the construction of an aligned scaffold under magnetic induction. However, a single topological cue is insufficient to activate neural tissue regeneration, demanding more cues to promote regeneration synergistically, such as electrical stimulation and a biomimetic matrix. Herein, we propose one-dimensional (1D) magnetoelectric Fe3O4@BaTiO3 nanochains with controllable lengths under the regulation of a magnetic field. These nanochains can be oriented in the biomimetic hydrogel under magnetic guidance and induce the hydrogel microfiber to align along the direction of the nanochains, which is beneficial for cell-oriented outgrowth. This aligned hydrogel enabled wireless electrical stimulation mediated by magnetoelectric nanochains under magnetic stimulation, thereby activating the voltage-gated ion channel. Consequently, topological and electrical cues in this multifunctional biomimetic hydrogel synergistically enhanced the expression of neural functional proteins, facilitating synapse remodeling and neural regeneration. Predictably, the construction of multifunctional hydrogels based on low-cost and facile synthesis of magnetoelectric nanochains is an emerging patient-friendly and effective therapeutic strategy for neural or other tissue regeneration. STATEMENT OF SIGNIFICANCE: A facile and controllable magnetic strategy is established to manipulate 1D nanomaterial growth, matrix topography, and wireless electrical stimulation of cells. First, the magnetic-assisted interface co-assembly was used to control the length of Fe3O4@BaTiO3 nanochains with enhanced magnetoelectric effect. Then, the motion of the magnetic-induced nanochains guided the orientation of nanofibers in a 3D biomimetic hydrogel matrix. Finally, wireless electrical signals and topological cues in the biomimetic matrix synergistically promoted orderly aligned cell outgrowth and membrane depolarization by Ca2+ influx, thus enhancing nerve cell synaptic plasticity and functional expression. Consequently, this work provides a conceptual strategy from material design to extracellular matrix signal manipulation and synergistic induction of tissue regeneration.

Therapeutic Potential of Chinese Medicine for Endogenous Neurogenesis: A Promising Candidate for Stroke Treatment

Strokes are a leading cause of morbidity and mortality in adults worldwide. Extensive preclinical studies have shown that neural-stem-cell-based treatments have great therapeutic potential for stroke. Several studies have confirmed that the effective components of traditional Chinese medicine can protect and maintain the survival, proliferation, and differentiation of endogenous neural stem cells through different targets and mechanisms. Therefore, the use of Chinese medicines to activate and promote endogenous nerve regeneration and repair is a potential treatment option for stroke patients. Here, we summarize the current knowledge regarding neural stem cell strategies for ischemic strokes and the potential effects of these Chinese medicines on neuronal regeneration.

Pushen capsule treatment promotes functional recovery after ischemic stroke

BACKGROUND

As a leading cause of long-term disability, ischemic stroke urgently needs further research and drug development. Pushen capsule (Pushen) has been commonly applied in clinical treatment for relieving headaches, dizziness, and numbness. However, the effects of Pushen on ischemic stroke have not been revealed yet.

PURPOSE

To assess the efficiency of Pushen in ischemic stroke and identify its potential therapeutic targets and active ingredients for treating ischemic stroke.

STUDY DESIGN AND METHODS

Behavioural experiments, Triphenyltetrazolium chloride (TTC) staining, Magnetic resonance imaging (MRI), and immunofluorescence staining were performed to examine the efficiency of Pushen in stroke model mice. The potential mechanism and active ingredients of Pushen were assessed by transcriptome, 16S rDNA sequencing, metabonomics, and network pharmacology. Finally, the targets were validated by RT-PCR, chromatin immunoprecipitation (ChIP), ELISA, and molecular docking methods.

RESULTS

Pushen had several effects on stroke model mice, including reducing the infarct volume, improving the blood‒brain barrier (BBB), and promoting functional restoration. Furthermore, the network pharmacology, LC-MS/MS, and molecular docking results revealed that tricin, quercetin, luteolin, kaempferol, and physcion were identified as the key active ingredients in Pushen that treated ischemic stroke. Mechanistically, these key ingredients could bind with the transcription factor c-Myc and thereby regulate the expression of Adora2a, Drd2, and Ppp1r1b, which are enriched in the cAMP signaling pathway. Additionally, Pushen improved the gut microbiota dysbiosis and reduced inosine levels in feces and serum, thereby reducing Adora2a expression in the brain.

CONCLUSIONS

Our study confirmed that Pushen was effective for treating ischemic stroke and has promising clinical applications.

Role of protein phosphorylation in cell signaling, disease, and the intervention therapy

Protein phosphorylation is an important post-transcriptional modification involving an extremely wide range of intracellular signaling transduction pathways, making it an important therapeutic target for disease intervention. At present, numerous drugs targeting protein phosphorylation have been developed for the treatment of various diseases including malignant tumors, neurological diseases, infectious diseases, and immune diseases. In this review article, we analyzed 303 small-molecule protein phosphorylation kinase inhibitors (PKIs) registered and participated in clinical research obtained in a database named Protein Kinase Inhibitor Database (PKIDB), including 68 drugs approved by the Food and Drug Administration of the United States. Based on previous classifications of kinases, we divided these human protein phosphorylation kinases into eight groups and nearly 50 families, and delineated their main regulatory pathways, upstream and downstream targets. These groups include: protein kinase A, G, and C (AGC) and receptor guanylate cyclase (RGC) group, calmodulin-dependent protein kinase (CaMK) group, CMGC [Cyclin-dependent kinases (CDKs), Mitogen-activated protein kinases (MAPKs), Glycogen synthase kinases (GSKs), and Cdc2-like kinases (CLKs)] group, sterile (STE)-MAPKs group, tyrosine kinases (TK) group, tyrosine kinase-like (TKL) group, atypical group, and other groups. Different groups and families of inhibitors stimulate or inhibit others, forming an intricate molecular signaling regulatory network. This review takes newly developed new PKIs as breakthrough point, aiming to clarify the regulatory network and relationship of each pathway, as well as their roles in disease intervention, and provide a direction for future drug development.

Storax Protected Primary Cortical Neurons from Oxygen-Glucose Deprivation/Reoxygenation Injury via Inhibiting the TLR4/TRAF6/NF-κB Signaling Pathway

Storax is a traditional Chinese herb that is widely applied in stroke treatment. However, its neuroprotective effects and mechanisms are yet to be fully elucidated. This study aimed to elucidate the neuroprotective effects and underlying mechanisms of storax on oxygen-glucose deprivation/reoxygenation (OGD/R) in injured cortical neurons. The cortical neurons of Wistar rats were primarily cultured in vitro. TheTUNELmethod and CM-H2DCFDA probe were used to detect cell apoptosis and reactive oxygen species (ROS) expression. Enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, and Western blot were used to detect the expression of inflammatory cytokines and proteins of the TLR4/TRAF6/NF-κB signaling pathway. Immunofluorescence was used to measure NF-κB nuclear translocation. Transfection of TLR4 siRNA was used to detect the potential anti-inflammatory mechanisms of storax. The present results have shown that storax protected primary cortical neurons from OGD/R-induced injury by suppressing ROS generation and cell apoptosis; alleviating HMGB-1, TNF-α, IL-1β, and ICAM-1 expression; and promoting IL-10 expression. In addition, storax inhibited the activation of TLR4, TRAF6, IκBα, IKKβ, and NF-κBp65 caused by OGD/R. It is suggested that storax prevents OGD/R-induced primary cortical neuron injury by inhibiting the TLR4/TRAF6/NF-κB signaling pathway.

Neurobehavioral and Biochemical Evidences in Support of Protective Effect of Marrubiin (Furan Labdane Diterpene) from Marrubium vulgare Linn. and Its Extracts after Traumatic Brain Injury in Experimental Mice

Traumatic brain injuries due to sudden accidents cause major physical and mental health problems and are one of the main reasons behind the mortality and disability of patients. Research on alternate natural sources could be a boon for the rehabilitation of poor TBI patients. The literature indicates the Marrubium vulgare Linn. and its secondary metabolite marrubiin (furan labdane diterpene) possess various pharmacological properties such as vasorelaxant, calcium channel blocker, antioxidant, and antiedematogenic activities. Hence, in the present research, both marrubiin and hydroalcoholic extracts of the plant were evaluated for their neuroprotective effect after TBI. The neurological severity score and oxidative stress parameters are significantly altered by the test samples. Moreover, the neurotransmitter analysis indicated a significant change in GABA and glutamate. The histopathological study also supported the observed results. The improved neuroprotective potential of the extract could be attributed to the presence of a large number of secondary metabolites including marrubiin.

Application of transcriptome analysis to understand the adverse effects of hydrogen peroxide exposure on brain function in common carp (Cyprinus carpio)

Hydrogen peroxide (H₂O₂), as a common disinfectant, has been extensively used in aquaculture. The toxicity of high ambient H₂O₂ for gills and liver of fish has received attention from many researchers. However, whether H₂O₂ exposure induced brain injury and neurotoxicity has not been reported in fish. Therefore, this study aimed to explore the potential mechanism of H₂O₂ toxicity in brain of common carp via transcriptome analysis and biochemical parameter detection. The fish were exposed to 0 (control) and 1 mM of H₂O₂ for 1 h per day lasting 14 days. The results showed that H₂O₂ exposure caused oxidative damage in brain evidenced by decreased glutathione (GSH), total antioxidant capacity (T-AOC) and nicotinamide adenine dinucleotide (NAD⁺) levels, and increased formation of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Meanwhile, H₂O₂ exposure reduced 5-hydroxytryptamine (5-HT) level, and down-regulated tryptophan hydroxylase 1 (tph1a), tph2, 5-hydroxytryptamine receptor 1A-beta (htr1ab) and htr2b expression in brain. Transcriptome analysis showed that H₂O₂ exposure up-regulated 604 genes and down-regulated 1209 genes in brain. Go enrichment displayed that the differently expressed genes (DEGs) were enriched mainly in cellular process, single-organism process, metabolic process, and biological regulation in the biological process category. Further, KEGG enrichment indicated that H₂O₂ exposure led to dysregulation of neurotransmitter signals including depression of glutamatergic synapse, GABAergic synapse and endocannabinoid signaling. Also, we found the alteration of three key pathways including calcium, cAMP and HIF-1 in brain after H₂O₂ exposure. In conclusion, our data indicated that H₂O₂ exposure induced oxidative damage and neurotoxicity, possibly related to dysregulation of neurotransmitters and calcium, cAMP and HIF-1 signaling pathways, which may adversely affect learning, memory and social responses of common carp. This study provided novel insight into biological effects and underlying mechanism of H₂O₂ toxicity in aquatic animal, and contributed to proper application of H₂O₂ in aquaculture.

Virtual Screening of the Multi-pathway and Multi-gene Regulatory Molecular Mechanism of Dachengqi Decoction in the Treatment of Stroke Based on Network Pharmacology

BACKGROUND

Stroke is ranked second among diseases that cause mortality worldwide. Owing to its complicated pathogenesis, no satisfactory treatment strategies for stroke are available. Dachengqi decoction (DCQD), a traditional Chinese herbal medicine, has been widely used in China for a long time, as it has a good effect on stroke. However, the molecular mechanism underlying this effect of DCQD is unclear.

OBJECTIVE

In the present study, we aimed to reveal and explore the multi-pathway and multi-gene regulatory molecular mechanism of Dachengqi decoction in the treatment of stroke.

METHODS

In this study, a network pharmacology method, in combination with oral bioavailability prediction and drug-likeness evaluation, was employed to predict the active ingredients of DCQD. The target genes of the active components and the traced pathways related to these target genes were predicted. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using clusterProfiler software package on the R platform and ClueGo+CluePedia plug-ins. Finally, the key DCQD targets were verified using the Gene Expression Omnibus (GEO) dataset.

RESULTS AND DISCUSSION

According to the ADME model, 52 active components were screened from 296 active components of DCQD. After prediction and screening, 215 stroke-related targets were obtained and analyzed via GO and KEGG analyses. GO analysis showed that DCQD targets were mainly involved in the regulation of oxidative stress, lipid metabolism, inflammation, and other biological processes. KEGG pathway analysis further revealed pathways involved in stroke, such as arachidonic acid metabolic, HIF-1 signaling pathway, estrogen signaling pathway, MAPK signaling pathway, PI3K-Akt signaling pathway, platelet activation pathway, VEGF signaling pathway, and cAMP signaling pathway. Network analysis revealed that DCQD might be involved in the regulation of lipid metabolism, blood pressure, inflammation, angiogenesis, neuroprotection, platelet aggregation, apoptosis, and oxidation in stroke treatment. GEO dataset analysis showed that DCQD's therapeutic effects might be exerted via the bidirectional regulation principle.

CONCLUSION

Based on the methods of network pharmacology and GEO analysis, it was found that, during stroke treatment, DCQD regulates and controls multiple genes and multiple pathways in a synergistic manner, providing a new strategy for stroke treatment.

Overexpressed HspB6 Underlines a Novel Inhibitory Role in Kainic Acid-Induced Epileptic Seizure in Rats by Activating the cAMP-PKA Pathway

Epilepsy is a commonly occurring neurological disease that has a large impact on the patient's daily life. Phosphorylation of heat shock protein B6 (HspB6) has been reported to protect the central nervous system. In this investigation, we explored whether HspB6 played a positive effect on epilepsy with the involvement of the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway. The epileptic seizure was induced in rats by intraperitoneal injection of kainic acid (KA). The extent of HspB6 phosphorylation and expressions of HspB6, PKA, and inflammatory factors TNF-α, IL-1β, and IL-6 were quantified along with neuronal apoptosis. To further understand the regulatory mechanism of the HspB6 in the hippocampus, we altered the expression and the extent of HspB6 phosphorylation to see whether the cAMP-PKA pathway was inactivated or not in hippocampal neurons of rats post KA. Results showed that HspB6 was poorly expressed, resulting in the inactivation of the cAMP-PKA pathway in rats post KA, as well as an aggravated inflammatory response and hippocampal neuronal apoptosis. HspB6 overexpression and the cAMP-PKA pathway activation decreased the expression of inflammatory factors and inhibited hippocampal neuronal apoptosis. Additionally, HspB6 phosphorylation further augments the inhibitory effects of HspB6 on the inflammatory response and hippocampal neuronal apoptosis. The cAMP-PKA pathway activation was found to result in increased HspB6 phosphorylation. HspB6 decreased apoptosis signal-regulating kinase 1 (ASK1) expression to inhibit inflammatory response and hippocampal neuronal apoptosis. Collectively, our findings demonstrate that activation of the cAMP-PKA pathway induces overexpression and partial phosphorylation of HspB6 lead to the inhibition of ASK1 expression. This in turn protects rats against epilepsy and provides a potential approach to prevent the onset of epileptic seizure in a clinical setting.

Signaling transduction regulated by 5-hydroxytryptamine 1A receptor and orexin receptor 2 heterodimers

As G-protein-coupled receptors (GPCRs), 5-hydroxytryptamine 1A receptor (5-HT1AR) and orexin receptor 2 (OX2R) regulate the levels of the cellular downstream molecules. The heterodimers of different GPCRs play important roles in various of neurological diseases. Moreover, 5-HT1AR and OX2R are involved in the pathogenesis of neurological diseases such as depression with deficiency of hippocampus plasticity. However, the direct interaction of the two receptors remains elusive. In the present study, we firstly demonstrated the heterodimer formation of 5-HT1AR and OX2R. Exchange protein directly activated by cAMP (Epac) cAMP bioluminescence resonance energy transfer (BRET) biosensor analysis revealed that the expression levels of cellular cAMP significantly increased in HEK293T cells transfected with the two receptors compared with the 5-HT1AR group. Additionally, the cellular level of calcium was upregulated robustly in HEK293T cells co-transfected with 5-HT1AR and OX2R group after agonist treatment. Furthermore, western blotting data showed that 5-HT1AR and OX2R heterodimer decreased the levels of phosphorylation of extracellular signal-regulated kinase (ERK) and cAMP-response element-binding protein (CREB). These results not only unraveled the formation of 5-HT1AR and OX2R heterodimer but also suggested that the heterodimer affected the downstream signaling pathway, which will provide new insights into the function of the two receptors in the brain.

Post-translational modifications in MeHg-induced neurotoxicity

Mercury (Hg) exposure remains a major public health concern due to its widespread distribution in the environment. Organic mercurials, such as MeHg, have been extensively investigated especially because of their congenital effects. In this context, studies on the molecular mechanism of MeHg-induced neurotoxicity are pivotal to the understanding of its toxic effects and the development of preventive measures. Post-translational modifications (PTMs) of proteins, such as phosphorylation, ubiquitination, and acetylation are essential for the proper function of proteins and play important roles in the regulation of cellular homeostasis. The rapid and transient nature of many PTMs allows efficient signal transduction in response to stress. This review summarizes the current knowledge of PTMs in MeHg-induced neurotoxicity, including the most commonly PTMs, as well as PTMs induced by oxidative stress and PTMs of antioxidant proteins. Though PTMs represent an important molecular mechanism for maintaining cellular homeostasis and are involved in the neurotoxic effects of MeHg, we are far from understanding the complete picture on their role, and further research is warranted to increase our knowledge of PTMs in MeHg-induced neurotoxicity.