Mechanism research on microRNA-669f-5p/deoxycytidylate deaminase axis mediating sevoflurane-induced cognitive dysfunction in aged mice.

OBJECTIVE: To investigate the role of the microRNA (miRNA)-669f-5p/deoxycytidylate deaminase (Dctd) axis in sevoflurane inducing cognitive dysfunction in aged mice. METHODS: Sixty-six C57BL/6J mice were used in the experiment model and were randomly divided into the sevoflurane group and the control group. The mice in the sevoflurane group were anesthetised with 3.4% sevoflurane, whereas those in the control group were air-treated for the same period. The study was then performed using bioinformatics sequencing, as well as in vitro and in vivo validation. RESULTS: The mice in the sevoflurane group showed significant cognitive impairments in terms of a decrease in both spatial learning and memory abilities. Experimental doses of miR-669f-5p agonist exhibited no obvious effect on cognitive function following sevoflurane inhalation, but inhibiting the expression of miR-669f-5p could alleviate the impairments. Based on the results of the bioinformatics sequencing, miR-669f-5p/Dctd and the toll-like receptor (TLR) signalling pathway could be the key miRNA, gene and pathway leading to postoperative cognitive dysfunction following sevoflurane inhalation. The aged mice showed significantly increased expression of miR-669f-5p in the hippocampus following sevoflurane inhalation, and upregulating/inhibiting its expression could increase/decrease TLR expression in the hippocampus. Furthermore, miR-669f-5p could reduce the expression of the Dctd gene by binding to its 3'untranslated region. CONCLUSION: The miR-669f-5p/Dctd axis plays an important role in sevoflurane inducing cognitive dysfunction in aged mice, providing a new direction for further development of therapeutic strategies concerning the prevention and treatment of cognitive dysfunction associated with sevoflurane anaesthesia.

Peripheral inflammation as a potential mechanism and preventive strategy for perioperative neurocognitive disorder under general anesthesia and surgery.

General anesthesia, as a commonly used medical intervention, has been widely applied during surgical procedures to ensure rapid loss of consciousness and pain relief for patients. However, recent research suggests that general anesthesia may be associated with the occurrence of perioperative neurocognitive disorder (PND). PND is characterized by a decline in cognitive function after surgery, including impairments in attention, memory, learning, and executive functions. With the increasing trend of population aging, the burden of PND on patients and society's health and economy is becoming more evident. Currently, the clinical consensus tends to believe that peripheral inflammation is involved in the pathogenesis of PND, providing strong support for further investigating the mechanisms and prevention of PND.

Progress in the correlation of postoperative cognitive dysfunction and Alzheimer's disease and the potential therapeutic drug exploration.

Postoperative cognitive dysfunction (POCD) is a decrease in mental capacity that can occur days to weeks after a medical procedure and may become permanent and rarely lasts for a longer period of time. With the continuous development of research, various viewpoints in academic circles have undergone subtle changes, and the role of anesthesia depth and anesthesia type seems to be gradually weakened; Alzheimer's disease (AD) is a latent and progressive neurodegenerative disease in the elderly. The protein hypothesis and the synaptic hypothesis are well-known reasons. These changes will also lead to the occurrence of an inflammatory cascade. The exact etiology and pathogenesis need to be studied. The reasonable biological mechanism affecting brain protein deposition, neuroinflammation, and acetylcholine-like effect has a certain relationship between AD and POCD. Whereas there is still further uncertainty about the mechanism and treatment, and it is elusive whether POCD is a link in the continuous progress of AD or a separate entity, which has doubts about the diagnosis and treatment of the disease. Therefore, this review is based on the current common clinical characteristics of AD and POCD, and pathophysiological research, to search for their common points and explore the direction and new strategies for future treatment.

Molecular profiles and circulating tumor-DNA detected in Chinese early stage breast cancer.

Background: With the development of gene-sequencing technology, genome biomarkers, including Erb-B2 receptor tyrosine kinase 2 (ERBB2), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (pIK3CA), BReast CAncer gene 1 (BRCA1), and BReast CAncer gene 2 (BRCA2), and immunomarkers, including the tumor mutational burden (TMB) and programmed death-ligand 1 (PD-L1), have become important in the selection of treatment. Methods: Twenty patients with early stage breast cancer who underwent surgery were enrolled in this study. Tissue samples and paired postoperative peripheral blood samples were collected and subjected to the targeted-capture sequencing of 1,021 cancer-associated genes. Results: The most frequently altered genes were tumor protein 53 (TP53; 70%), PIK3CA (40%), protooncogene MYC (35%), ERBB2 (30%), and cyclin-dependent kinase 12 (CDK12; 20%). Six (30%) patients presented with ERBB2 amplification of NGS and simultaneously were positive for human epidermal growth factor receptor 2 (HER2) of IHC. ERBB2 amplification and being HER2 positive were common in breast cancer patients without lymph node metastasis (5/6, 83.3%) and those in stages IA-IIA. Most of the somatic mutations clustered in the TP53 pathway, followed by the PI3K pathway. The TMB was lower than metastatic breast cancer in our cohort, and ranged from 0 to 9.6 mut/Mb (median: 1.92 mut/Mb). Interestingly, more patients had the ERBB2 mutation in the non-lymph node metastasis group than the lymph node metastasis group (55.6% vs. 9.1%; P=0.049). Similarly, more patients had the CDK12 mutation in the non-lymph node metastasis group than the lymph node metastasis group (44.4% vs. 0%; P=0.026). Circulating tumor deoxyribonucleic acid (ctDNA) was detected in 7 of the 20 patients (35%). Of these patients, 71.4% (5/7) were in stage I/II. In addition, no correlation was found between ctDNA detection and clinicopathological features or the driver gene mutations (e.g., PIK3CA and ERBB2). However, patients positive for ctDNA had a higher TMB than those negative for ctDNA when grouped according to the median TMB (1.92 mut/Mb; 85.7% vs. 38.5%; P=0.043). Conclusions: This study described that genomic characteristics of Chinese early stage breast cancer, and the results showed that TMB was related to the detection of ctDNA in postoperative blood.

Hispidin inhibits LPS-induced nitric oxide production in BV-2 microglial cells via ROS-dependent MAPK signaling.

Neuroinflammation is associated with many neurodegenerative diseases. Abnormal activation of microglial cells in the central nervous system (CNS) is a major characteristic of neuroinflammation. Nitric oxide (NO) free radicals are produced by activated microglia and prolonged presence of large quantities of NO in the CNS can lead to neuroinflammation and disease. Hispidin is a polyphenol derived from Phellinus linteus (a valuable medicinal mushroom) with strong antioxidant, anticancer and antidiabetic properties. A previous study demonstrated that hispidin significantly inhibited NO production via lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Therefore, the present study used MTT assay was used to detect the effect of hispdin on cell viability. Griess reagent analysis was used to measure NO production. Reverse transcription-semi quantitative PCR and western blotting were used to evaluate the effects of hispdin on iNOS mRNA and MAPK/ERK/JNK protein levels. Fluorescence microscopy and flow cytometry were used to detect the effects of hispdin on the production of ROS and phagocytosis of cells. The present results indicated that hispidin could significantly inhibit the increase of NO production and iNOS expression in BV-2 microglial cells stimulated by LPS. The inhibitory effect of hispidin on NO production was similar to that of S-methylisothiourea sulfate, an iNOS inhibitor. Signaling studies demonstrated that hispidin markedly suppresses LPS-induced mitogen activated protein kinases and JAK1/STAT3 activation, although not the NF-κB signaling pathway. The present observations in LPS-stimulated BV-2 microglial cells indicated that hispidin might serve as a therapeutic candidate for the treatment of NO-induced neuroinflammation and, potentially, as a novel iNOS inhibitor.

Curcumin Activates ROS Signaling to Promote Pyroptosis in Hepatocellular Carcinoma HepG2 Cells.

BACKGROUND/AIM: Curcumin is a polyphenol that exerts a variety of pharmacological activities and plays an anti-cancer role in many cancer cells. It was recently reported that gasdermin E (GSDME) is involved in the progression of pyroptosis. MATERIALS AND METHODS: HepG2 cells were treated with various concentrations of curcumin and cell viability was examined using MTT assay, apoptosis was analysed using flow cytometry, reactive oxygen species (ROS) levels using dihydroethidium, LDH release using an LDH cytotoxicity assay, and protein expression using western blot. RESULTS: Curcumin increased the expression of the GSDME N-terminus and proteins involved in pyrolysis, promoted HspG2 cell pyrolysis and increased intracellular ROS levels. Moreover, inhibition of the production of intracellular ROS with n-acetylcysteine (NAC) improved the degree of apoptosis and pyrolysis induced by curcumin. CONCLUSION: Curcumin induces HspG2 cell death by increasing apoptosis and pyroptosis, and ROS play a key role in this process. This study improves our understanding of the potential anti-cancer properties of curcumin in liver cancer.

New progress of isoflurane, sevoflurane and propofol in hypoxic-ischemic brain injury and related molecular mechanisms based on p75 neurotrophic factor receptor.

Hypoxic ischemic brain injury (HIBI) is one of the most common clinical disorders, especially in neonates. The complex pathophysiology of HIBI is an important cause of disability and even death of patients, however, being without effective clinical treatments. Common anesthetics (such as isoflurane, propofol and sevoflurane) have an adverse impact on neuronal cells for HIBI via the regulation of p75 neurotrophic factor receptor (P75NTR). In order to protect the injured brains and study the effect of underlying treatments, it is particularly significant to understand and master the developmental mechanism of anesthetics for the occurrence of HIBI related molecular mechanisms. Therefore, this paper will mainly review the corresponding pathogenic and protective mechanisms about HIBI binding to the research progress of the role of P75NTR. In conclusion, the effects of neuroprotection and injured nerves are involved in the expression and activation of P75NTR, mainly increased P75NTR mRNA, protein levels and calpain-dependent for propofol, and inducing neuronal apoptosis for isoflurane and sevoflurane, and we look forward to that connection with P75NTR, common anaesthetic and HIBI may be a new direction of research and gain perfect outcomes in the future.

HDAC3-mediated silencing of miR-451 decreases chemosensitivity of patients with metastatic castration-resistant prostate cancer by targeting NEDD9.

BACKGROUND: Treatment of metastatic castration-resistant prostate cancer (mCRPC) with docetaxel often fails due to the emergence of chemoresistance. Thus, restoring chemosensitivity to docetaxel-based therapies remains a challenge in mCRPC treatment. METHODS: microRNA (miR)-451 expression was measured in docetaxel-treated prostate cancer cells and tumor tissues by quantitative reverse-transcription polymerase chain reaction . Cell-counting kit 8 assay was performed to determine docetaxel chemoresistance. Neural-precursor-cell-expressed developmentally downregulated protein 9 (NEDD9) was identified as a novel target of miR-451 by dual-luciferase reporter system. Chromatin immunoprecipitation and co-immunoprecipitation assay were performed to confirm that histone deacetylase 3 (HDAC3)/Sp1 (a highly evolutionarily conserved transcription factor) interacted with the Sp1 binding sites in miR-451 promoter. RESULTS: miR-451 was found to be silenced in docetaxel-treated prostate cancer cells and mCRPC tissues. Low miR-451 expression was closely associated with a high Gleason score, high Eastern Cooperative Oncology Group performance status score, visceral metastasis and poor prognosis. Low expression of miR-451 was significantly correlated with short progression-free survival (PFS) and overall survival (OS) according to Kaplan-Meier analysis, and miR-451 was determined to be an independent poor prognostic factor for PFS and OS in mCRPC patients by univariate and multivariate Cox regression analyses. NEDD9 was identified as a new and functional target of miR-451. Restoration of NEDD9 partially reversed the effects of miR-451 on enhancing chemosensitivity of prostate cancer cells. HDAC3 was confirmed to be involved in silencing of miR-451 expression in prostate cancer cells. CONCLUSIONS: The current data revealed a new HDAC3/Sp1/miR-451/NEDD9 signaling axis that regulates the chemosensitivity of prostate cancer cells and represents a novel therapeutic target for chemosensitizing mCRPC.

MicroRNA-451: epithelial-mesenchymal transition inhibitor and prognostic biomarker of hepatocelluar carcinoma.

Increasing evidence indicates that dysregulation of microRNAs (miRNAs) plays critical roles in malignant transformation and tumor progression. Previously, we have shown that microRNA-451 (miR-451) inhibits growth, increases chemo- or radiosensitivity and reverses epithelial to mesenchymal transition (EMT) in lung cancer. However, the roles of miR-451 in hepatocelluar carcinoma (HCC) progression and metastasis are still largely unknown. Reduced miR-451 in HCC tissues was observed to be significantly correlated with advanced clinical stage, metastasis and worse disease-free or overall survival. Through gain- and loss-of function experiments, we demonstrated that miR-451 inhibited cell growth, induced G0/G1 arrest and promoted apoptosis in HCC cells. Importantly, miR-451 could inhibit the migration and invasion in vitro, as well as in vivo metastasis of HCC cells through regulating EMT process. Moreover, the oncogene c-Myc was identified as a direct and functional target of miR-451 in HCC cells. Knockdown of c-Myc phenocopied the effects of miR-451 on EMT and metastasis of HCC cells, whereas overexpression of c-Myc partially attenuated the functions of miR-451 restoration. Furthermore, miR-451 downregulation-induced c-Myc overexpression leads to the activation of Erk1/2 signaling, which induces acquisition of EMT phenotype through regulation of GSK-3ß/snail/E-cadherin and the increased expression of MMPs family members in HCC cells. Collectively, these data demonstrated that miR-451 is a novel prognostic biomarker for HCC patients and that function as a potential metastasis inhibitor in HCC cells through activation of the Erk1/2 signaling, at least partially by targeting c-Myc. Thus, targeting miR-451/c-Myc/Erk1/2 axis may be a potential strategy for the treatment of metastatic HCC.

Histone deacetylase 1/Sp1/microRNA-200b signaling accounts for maintenance of cancer stem-like cells in human lung adenocarcinoma.

The presence of cancer stem-like cells (CSCs) is one of the mechanisms responsible for chemoresistance that has been a major hindrance towards lung adenocarcinoma (LAD) treatment. Recently, we have identified microRNA (miR)-200b as a key regulator of chemoresistance in human docetaxel-resistant LAD cells. However, whether miR-200b has effects on regulating CSCs remains largely unclear and needs to be further elucidated. Here, we showed that miR-200b was significantly downregulated in CD133+/CD326+ cells that exhibited properties of CSCs derived from docetaxel-resistant LAD cells. Also, restoration of miR-200b could inhibit maintenance and reverse chemoresistance of CSCs. Furthermore, suppressor of zeste-12 (Suz-12) was identified as a direct and functional target of miR-200b, and silencing of Suz-12 phenocopied the effects of miR-200b on CSCs. Additionally, overexpression of histone deacetylase (HDAC) 1 was identified as a pivotal mechanism responsible for miR-200b repression in CSCs through a specificity protein (Sp) 1-dependent mechanism, and restoration of miR-200b by HDAC1 repression significantly suppressed CSCs formation and reversed chemoresistance of CSCs by regulating Suz-12-E-cadherin signaling. Also, downregulation of HDAC1 or upregulation of miR-200b reduced the in vivo tumorigenicity of CSCs. Finally, Suz-12 was inversely correlated with miR-200b, positively correlated with HDAC1 and up-regulated in docetaxel-resistant LAD tissues compared with docetaxel-sensitive tissues. Taken together, the HDAC1/miR-200b/Suz-12-E-cadherin signaling might account for maintenance of CSCs and formation of chemoresistant phenotype in docetaxel-resistant LAD cells.

Acquisition of radioresistance in docetaxel-resistant human lung adenocarcinoma cells is linked with dysregulation of miR-451/c-Myc-survivin/rad-51 signaling.

Chemoresistant tumors usually fail to respond to radiotherapy. However, the mechanisms involved in chemo- and radiotherapy cross resistance are not fully understood. Previously, we have identified microRNA (miR)-451 as a tumor suppressor in lung adenocarcinoma (LAD). However, whether miR-451 plays critical roles in chemo- and radiotherapy cross resistance in LAD is unclear. Here, we established two docetaxel-resistant LAD cell models (SPC-A1/DTX and H1299/DTX), and showed that miR-451 was significantly downregulated in docetaxel-resistant LAD cells. Gain - and loss - of - function assays indicated that re-expression of miR-451 could reverse radioresistance of docetaxel-resistant LAD cells both in vitro and in vivo through promoting apoptosis and DNA double-strand breaks (DSBs). The proto-oncogene c-Myc was identified as a direct target of miR-451, and re-expression of miR-451 inhibited survivin and rad-51 expression by reducing the amount of c-Myc protein binding to their promoters. Silencing of c-Myc could phenocopy the effects of miR-451 upregulation, and restoration of c-Myc could partially rescue the effect of miR-451 upregulation on radiosensitivity of docetaxel-resistant LAD cells. Therefore, dysregulation of miR-451/c-Myc-survivin/rad-51 signaling is responsible for radioresistance of docetaxel-resistant LAD cells, and targeting it will be a potential strategy for reversing chemo- and radiotherapy cross resistance of LAD patients.

HDAC 1/4-mediated silencing of microRNA-200b promotes chemoresistance in human lung adenocarcinoma cells.

Chemoresistance is one of the most significant obstacles in lung adenocarcinoma (LAD) treatment, and this process involves genetic and epigenetic dysregulation of chemoresistance-related genes. Previously, we have shown that restoration of microRNA (miR)-200b significantly reverses chemoresistance of human LAD cells by targeting E2F3. However, the molecular mechanisms involved in the silencing of miR-200b are still unclear. Here we showed that histone deacetylase (HDAC) inhibitors could restore the expression of miR-200b and reverse chemoresistant phenotypes of docetaxel-resistant LAD cells. HDAC1/4 repression significantly increased miR-200b expression by upregulating histone-H3 acetylation level at the two miR-200b promoters partially via a Sp1-dependent pathway. Furthermore, silencing of HDAC1/4 suppressed cell proliferation, promoted cell apoptosis, induced G2/M cell cycle arrest and ultimately reversed in vitro and in vivo chemoresistance of docetaxel-resistant LAD cells, at least partially in a miR-200b-dependent manner. HDAC1/4 suppression-induced rescue of miR-200b contributed to downregulation of E2F3, survivin and Aurora-A, and upregulation of cleaved-caspase-3. HDAC1/4 levels in docetaxel-insensitive human LAD tissues, inversely correlated with miR-200b, were upregulated compared with docetaxel-sensitive tissues. Taken together, our findings suggest that the HDAC1/4/Sp1/miR-200b/E2F3 pathway is responsible for chemoresistance of docetaxel-resistant LAD cells.

Ca2+/calmodulin-dependent protein kinase IIdelta orchestrates G-protein-coupled receptor and electric field stimulation-induced cardiomyocyte hypertrophy.

1. G-Protein-coupled receptors (GPCR) and electrical field stimulation (EFS) regulate cardiac function and pathological remodelling, including cardiac hypertrophy. Cardiac Ca(2+)/calmodulin-dependent protein kinase (CaMK) IIdelta expression and activity are altered in cardiac hypertrophy and heart failure. The aim of the present study was to determine the effects of CaMKIIdelta isoforms on neonatal rat cardiomyocyte hypertrophy induced by GPCR and EFS. 2. Cardiac hypertrophy was induced by angiotensin II, phenylephrine or EFS and was confirmed by increases in cell volume, [(3)H]-leucine incorporation, sarcomere assembly and mRNA expression of atrial natriuretic factor and beta-myosin heavy chain. The effects of the CaMKII inhibitors KN93 and autocamtide 2-related inhibitory peptide (AIP) on cardiomyocyte hypertrophy were investigated, as was the effect of overexpression of dominate negative CaMKIIdelta. 3. Cardiomyocyte hypertrophy was inhibited by the CaMKII inhibitors KN93 and AIP and by overexpression of dominate negative CaMKIIdelta, but was potentiated by overexpression of wild-type CaMKIIdeltaB or CaMKIIdeltaC. Activation of CaMKII by GPCR agonists or EFS was inhibited by the CaMKII inhibitors. 4. The GPCR agonists and EFS synergistically activated CaMKII and upregulated CaMKIIdeltaB and CaMKIIdeltaC mRNA expression and protein synthesis. All these effects were abolished by the CaMKII inhibitors. 5. The findings of the present study indicate that CaMKII orchestrates additive prohypertrophic factors between GPCR agonists and EFS. Thus, CaMKII may be a useful target in the clinical treatment of hypertrophy and cardiac remodelling.

Inhibition of calcium-calmodulin-dependent kinase II suppresses cardiac fibroblast proliferation and extracellular matrix secretion.

Calcium-calmodulin-dependent protein kinase II (CaMKII) is one of the main protein kinases mediating intracellular Ca changes. It is also involved in the process of cardiac diseases, such as cardiac hypertrophy, but its effects on myocardial fibrosis remain unclear. The present study investigates whether CaMKII is involved in cardiac fibroblast proliferation and extracellular matrix (ECM) secretion induced by angiotensin II (AngII) or electrical field stimulation (EFS) in cultured neonatal rat cardiac fibroblasts. Cardiac fibroblast proliferation was assessed by a cell survival assay (MTT) and manual cell enumeration. Cellular matrix production was demonstrated by matrix metalloproteinases (MMP) 1, 2, 9, and collagen I/III messenger RNA expression, MMP-2, 9 protein expression, and secretion of transforming growth factor beta1 and tumor necrosis factor alpha. Either AngII or EFS promoted cardiac fibroblast proliferation and ECM secretion, while also up-regulating expression of CaMKII deltaB and deltaC. More importantly, CaMKII inhibitors, autocamtide-2-related inhibitory peptide (AIP 5 microM) or KN93 (0.5 microM), suppressed cardiac fibroblast proliferation, inhibited the excretion of transforming growth factor beta1 and tumor necrosis factor alpha, decreased the messenger RNA expression of MMP-1, 2, 9 and collagen I/III, and decreased the protein expression of MMP-2, 9. These results suggest that CaMKII mediates cardiac fibroblast proliferation and ECM secretion induced by either AngII or EFS.