Repetitive Sequences, Codon Usage Bias and Phylogenetic Analysis of the Plastome of Miliusa glochidioides.

Annonaceae is the largest family in Magnoliales, exhibiting the greatest diversity among and within genera. In this study, we conducted an analysis of repetitive sequences and codon usage bias in the previously acquired plastome of Miliusa glochidioides. Using a concatenated dataset of shared genes, we constructed the phylogenetic relationships among 27 Annonaceae species. The results showed that the size of the plastomes in the Annonaceae ranged from 159 to 202 kb, with the size of the inverted repeat region ranging from 40 to 65 kb. Within the plastome of M. glochidioides, we identified 42 SSRs, 36 tandem repeats, and 9 dispersed repeats. These SSRs consist of three nucleotide types and eight motif types, with a preference for A/T bases, primarily located in the large single-copy regions and intergenic spacers. Tandem and dispersed repeat sequences were predominantly detected in the IR region. Through codon usage bias analysis, we identified 30 high-frequency codons and 11 optimal codons. The plastome of M. glochidioides demonstrated relatively weak codon usage bias, favoring codons with A/T endings, primarily influenced by natural selection. Phylogenetic analysis revealed that all four subfamilies formed monophyletic groups, with Cananga odorata (Ambavioideae) and Anaxagorea javanica (Anaxagoreoideae) successively nested outside Annonoideae + Malmeoideae. These findings improve our understanding of the plastome of M. glochidioides and provide additional insights for studying plastome evolution in Annonaceae.

Electromyographic features and efficacy of orofacial myofunctional treatment for skeletal anterior open bite in adolescents: an exploratory study.

BACKGROUND: Due to the multifactorial aetiology and unpredictable long-term stability, skeletal anterior open bite (SAOB) is one of the most intractable conditions for orthodontists. The abnormal orofacial myofunctional status (OMS) may be a major risk factor contributing to the development and relapse of SAOB. This study is aimed at evaluating the OMS and the efficacy of orofacial myofunctional therapy (OMT) alone for SAOB subjects. METHODS: Eighteen adolescents with SAOB (4 males, 14 females; age: 12-18 years) and eighteen adolescents with normal occlusion (2 males, 16 females; age: 12-18 years) were selected. The electromyographic activity (EMGA) associated with mastication and closed mouth state was measured. Lateral cephalography was used to evaluate craniofacial morphology. Wilcoxon signed rank tests and t-tests were performed to evaluate myofunctional and morphological differences. Pearson or Spearman correlation analysis was used to investigate the correlations between EMGA and morphological characteristics. SAOB subjects were given OMT for 3 months, and the EMGA was compared between before and after OMT. RESULTS: During rest, anterior temporalis activity (TAA) and mentalis muscle activity (MEA) increased in SAOB subjects, but TAA and masseter muscle activity (MMA) decreased in the intercuspal position (ICP); and upper orbicularis activity (UOA) and MEA significantly increased during lip sealing and swallowing (P < 0.05). Morphological evaluation revealed increases in the FMA, GoGn-SN, ANS-Me, N-Me, L1-MP, U6-PP, and L6-MP and decreases in the angle of the axis of the upper and lower central incisors and OB in SAOB subjects (P < 0.05). TAA, MMA and anterior digastric activity (DAA) in the ICP were negatively correlated with vertical height and positively correlated to incisor protrusion. MEA was positively correlated with vertical height and negatively correlated with incisor protrusion; and the UOA showed a similar correlation in ICP, during sealing lip and swallowing. After SAOB subjects received OMT, MEA during rest and TAA, MMA and DAA in the ICP increased, while UOA and MEA decreased (P < 0.05). CONCLUSION: SAOB subjects showed abnormal OMS features including aberrant swallowing patterns and weak masticatory muscles, which were interrelated with the craniofacial dysmorphology features including a greater anterior facial height and incisor protrusion. Furthermore, OMT contributes to OMS harmonization, indicating its therapeutic prospect in SAOB.

Acacetin-induced cell apoptosis in head and neck squamous cell carcinoma cells: Evidence for the role of muscarinic M3 receptor.

Aacacetin, a plant flavone has shown antitumor efficacy recently. However, its associated mechanisms are poorly known. We hypothesized that the muscarinic M3 receptor (M3 R), which is highly expressed in some cancer tissue, is related to the antitumor effect of acacetin in head and neck squamous cell carcinoma (HNSCC) cells. Our results showed that 12.5- to 200-µM acacetin inhibited cell viability in dose- and time-dependent manners in HNSCC cells, but a relative higher concentration was needed for oral adenoid cystic carcinoma cells. M3 R expression level was higher in HNSCC cells than that in adenoid cystic carcinoma cells. Flow cytometry and electron microscopy confirmed acacetin-induced cell apoptosis in 22B cells, a HNSCC cell line. Acacetin promoted mitochondrial cytochrome c release and caspase 9, 3 processing. Knocking down of M3 R expression by specific siRNA significantly prevented the acacetin-induced cell viability damage, cell apoptosis, and caspase 3 activation. Besides, M3 R was also involved in acacetin-induced elevation of reactive oxygen species and intracellular calcium ([Ca2+ ]i ). These data indicate that acacetin-induced cell apoptosis in HNSCC cells may through M3 R related calcium signaling and caspase 3 activation. Acacetin is a potent natural antitumor reagent especially for the tumor cells, which highly expressed M3 R.

Effects of amiloride on physiological activity of stem cells of human lung cancer and possible mechanism.

Lung cancer is a common malignant tumor, the cancer stem cells (CSCs) were regarded responsible for the development of cancer tissue. The effects of amiloride on lung cancer stem cells and the possible mechanism were not much investigated. In this study, human NCI-H1975 lung CSCs were selected by flow cytometry, and the effects of amiloride at different concentrations (0, 12.5, 25, 50, and 100 µmol/L) were evaluated on proliferation, migration, invasion and apoptosis of CSCs using cell counting kit-8 and Transwell migration assays as well as flow cytometry. Wstern blot analysis was performed to investigate the effect of amiloride on the level of proteins in uPA system, NF-kB pathway, and PI3K-AKT-mTOR pathway in CSCs. As a result, we found that amiloride inhibited proliferation, migration and invasion of lung CSCs, and promoted apoptosis. Further, we found that amiloride decreased levels of target proteins in the uPA system, as well as the NF-kB and PI3K-AKT-mTOR pathways. These results indicated that amiloride could inhibit proliferation, migration and invasion of lung CSCs, and promotes apoptosis, these effects may be related to decreased levels of proteins in the uPA system, the NF-kB pathway, and the PI3K-AKT-mTOR pathway.

Silencing PP2A inhibitor by lenti-shRNA interference ameliorates neuropathologies and memory deficits in tg2576 mice.

Deficits of protein phosphatase-2A (PP2A) play a crucial role in tau hyperphosphorylation, amyloid overproduction, and synaptic suppression of Alzheimer's disease (AD), in which PP2A is inactivated by the endogenously increased inhibitory protein, namely inhibitor-2 of PP2A (I2(PP2A)). Therefore, in vivo silencing I2(PP2A) may rescue PP2A and mitigate AD neurodegeneration. By infusion of lentivirus-shRNA targeting I2(PP2A) (LV-siI2(PP2A)) into hippocampus and frontal cortex of 11-month-old tg2576 mice, we demonstrated that expression of LV-siI2(PP2A) decreased remarkably the elevated I2(PP2A) in both mRNA and protein levels. Simultaneously, the PP2A activity was restored with the mechanisms involving reduction of the inhibitory binding of I2(PP2A) to PP2A catalytic subunit (PP2AC), repression of the inhibitory Leu309-demethylation and elevation of PP2AC. Silencing I2(PP2A) induced a long-lasting attenuation of amyloidogenesis in tg2576 mice with inhibition of amyloid precursor protein hyperphosphorylation and ß-secretase activity, whereas simultaneous inhibition of PP2A abolished the antiamyloidogenic effects of I2(PP2A) silencing. Finally, silencing I2(PP2A) could improve learning and memory of tg2576 mice with preservation of several memory-associated components. Our data reveal that targeting I2(PP2A) can efficiently rescue Aß toxicities and improve the memory deficits in tg2576 mice, suggesting that I2(PP2A) could be a promising target for potential AD therapies.

Association of Vegetables-Fruits Dietary Patterns with Gestational Diabetes Mellitus: Mediating Effects of Gut Microbiota.

(1) Introduction: Previous studies have found that diet can change gut microbiota, thereby affecting metabolic health. However, research on gestational diabetes mellitus (GDM) is still limited. Our study aimed to explore the mediating role of gut microbiota in the relationship between dietary patterns and GDM. (2) Methods: In this case-control study, 107 women with GDM at 24-28 weeks of gestation and 78 healthy pregnant women were enrolled. A semi-quantitative food frequency questionnaire (FFQ) was used to assess dietary intake over the previous month. Mediation analysis was performed to explore the link between dietary patterns, gut microbiota, and GDM. (3) Results: Among the five dietary patterns extracted, the high group (factor scores ≥ -0.07) of the vegetables-fruits dietary pattern had a 67% lower risk of developing GDM compared to the low group (factor scores < -0.07) (OR: 0.33; 95% CI: 0.15-0.74). In addition, a significant alteration was observed in gut microbiota composition among GDM pregnant women. Mediation analysis showed that the Lachnospiraceae family, Blautia, and Ruminococcus genus partially mediated the effect of vegetables-fruits dietary pattern on GDM, explaining 45.81%, 44.33%, and 31.53% of the association, respectively. (4) Conclusions: Adherence to vegetables-fruits dietary patterns during pregnancy may reduce the risk of GDM by altering gut microbiota composition.

Low-density lipoprotein receptor-related protein 1 mediates α-synuclein transmission from the striatum to the substantia nigra in animal models of Parkinson's disease.

α-Synuclein accumulation and transmission are vital to the pathogenesis of Parkinson's disease, although the mechanisms underlying misfolded α-synuclein accumulation and propagation have not been conclusively determined. The expression of low-density lipoprotein receptor-related protein 1, which is abundantly expressed in neurons and considered to be a multifunctional endocytic receptor, is elevated in the neurons of patients with Parkinson's disease. However, whether there is a direct link between low-density lipoprotein receptor- related protein 1 and α-synuclein aggregation and propagation in Parkinson's disease remains unclear. Here, we established animal models of Parkinson's disease by inoculating monkeys and mice with α-synuclein pre-formed fibrils and observed elevated low-density lipoprotein receptor-related protein 1 levels in the striatum and substantia nigra, accompanied by dopaminergic neuron loss and increased α-synuclein levels. However, low-density lipoprotein receptor-related protein 1 knockdown efficiently rescued dopaminergic neurodegeneration and inhibited the increase in α-synuclein levels in the nigrostriatal system. In HEK293A cells overexpressing α-synuclein fragments, low-density lipoprotein receptor-related protein 1 levels were upregulated only when the N-terminus of α-synuclein was present, whereas an α-synuclein fragment lacking the N-terminus did not lead to low-density lipoprotein receptor-related protein 1 upregulation. Furthermore, the N-terminus of α-synuclein was found to be rich in lysine residues, and blocking lysine residues in PC12 cells treated with α-synuclein pre-formed fibrils effectively reduced the elevated low-density lipoprotein receptor-related protein 1 and α-synuclein levels. These findings indicate that low-density lipoprotein receptor-related protein 1 regulates pathological transmission of α-synuclein from the striatum to the substantia nigra in the nigrostriatal system via lysine residues in the α-synuclein N-terminus.

Gallic Acid Alleviates Cognitive Impairment by Promoting Neurogenesis via the GSK3ß-Nrf2 Signaling Pathway in an APP/PS1 Mouse Model.

Background: Neuronal loss occurs early and is recognized as a hallmark of Alzheimer's disease (AD). Promoting neurogenesis is an effective treatment strategy for neurodegenerative diseases. Traditional Chinese herbal medicines serve as a rich pharmaceutical source for modulating hippocampal neurogenesis. Objective: Gallic acid (GA), a phenolic acid extracted from herbs, possesses anti-inflammatory and antioxidant properties. Therefore, we aimed to explore whether GA can promote neurogenesis and alleviate AD symptoms. Methods: Memory in mice was assessed using the Morris water maze, and protein levels were examined via western blotting and immunohistochemistry. GA's binding site in the promoter region of transcription regulator nuclear factor erythroid 2-related factor 2 (Nrf2) was calculated using AutoDock Vina and confirmed by a dual luciferase reporter assay. Results: We found that GA improved spatial memory by promoting neurogenesis in the hippocampal dentate gyrus zone. It also improved synaptic plasticity, reduced tau phosphorylation and amyloid-ß concentration, and increased levels of synaptic proteins in APP/PS1 mice. Furthermore, GA inhibited the activity of glycogen synthase kinase-3ß (GSK-3ß). Bioinformatics tools revealed that GA interacts with several amino acid sites on GSK-3ß. Overexpression of GSK-3ß was observed to block the protective effects of GA against AD-like symptoms, while GA promoted neurogenesis via the GSK-3ß-Nrf2 signaling pathway in APP/PS1 mice. Conclusions: Based on our collective findings, we hypothesize that GA is a potential pharmaceutical agent for alleviating the pathological symptoms of AD.

Effects of chronotherapy of benazepril on the diurnal profile of RAAS and clock genes in the kidney of 5/6 nephrectomy rats.

This study investigated the effects of benazepril administered in the morning or evening on the diurnal variation of renin-angiotensin-aldosterone system (RAAS) and clock genes in the kidney. The male Wistar rat models of 5/6 subtotal nephrectomy (STNx) were established. Animals were randomly divided into 4 groups: sham STNx group (control), STNx group, morning benazepril group (MB) and evening benazepril group (EB). Benazepril was intragastrically administered at a dose of 10 mg/kg/day at 07:00 and 19:00 in the MB group and EB group respectively for 12 weeks. All the animals were synchronized to the light:dark cycle of 12:12 for 12 weeks. Systolic blood pressure (SBP), 24-h urinary protein excretion and renal function were measured at 11 weeks. Blood samples and kidneys were collected every 4 h throughout a day to detect the expression pattern of renin activity (RA), angiotensin II (AngII) and aldosterone (Ald) by radioimmunoassay (RIA) and the mRNA expression profile of clock genes (bmal1, dbp and per2) by real-time PCR at 12 weeks. Our results showed that no significant differences were noted in the SBP, 24-h urine protein excretion and renal function between the MB and EB groups. There were no significant differences in average Ald and RA content of a day between the MB group and EB group. The expression peak of bmal1 mRNA was phase-delayed by 4 to 8 h, and the diurnal variation of per2 and dbp mRNA diminished in the MB and EB groups compared with the control and STNx groups. It was concluded when the similar SBP reduction, RAAS inhibition and clock gene profile were achieved with optimal dose of benazepril, morning versus evening dosing of benazepril has the same renoprotection effects.

The Protective Effects of Mogroside V Against Neuronal Damages by Attenuating Mitochondrial Dysfunction via Upregulating Sirtuin3.

Mitochondrial dysfunction and oxidative stress are thought to play a dominant role in the pathogenesis of Parkinson's disease (PD). Mogroside V (MV), extracted from Siraitia grosvenorii, exhibits antioxidant-like activities. The aim of this study was to investigate the function of MV in neuroprotection in PD and to reveal its mechanism of action. To that end, we firstly set up mice models of PD with unilateral striatum injection of 0.25 mg/kg rotenone (Rot) and co-treated with 2.5 mg/kg, 5 mg/kg, and 10 mg/kg MV by gavage. Results showed that Rot-induced motor impairments and dopaminergic neuronal damage were reversed by treatment of 10 mg/kg MV. Then, we established cellular models of PD using Rot-treated SH-SY5Y cells, which were divided into six groups, including control, Rot, and co-enzyme Q10 (CQ10), as well as MV groups, MV25, MV50, and MV100 treated with 25 µM, 50 µM, and 100 µM MV doses, respectively. Results demonstrated that MV effectively attenuates Rot neurotoxicity through a ROS-related intrinsic mitochondrial pathway. MV reduced overproduction of reactive oxygen species (ROS), recovered the mitochondrial membrane potential (MMP), and increased the oxygen consumption rate and adenosine triphosphate (ATP) production in a dose-dependent manner. Hence, treatment with MV led to a reduction in the number of apoptotic cells, as reflected by Annexin-V/propidium iodide co-staining using flow cytometry and TdT-mediated dUTP Nick-End Labeling (TUNEL) assay. In addition, the Sirtuin3 (SIRT3) protein level and activity were decreased upon exposure to Rot both in substantia nigra (SN) of mice and SH-SY5Y cells. SIRT3 impairment hyperacetylated a key mitochondrial antioxidant enzyme, superoxide dismutase 2 (SOD2). MV alleviates SIRT3 and SOD2 molecular changes. However, after successfully inhibiting SIRT3 by its specific inhibitor 3-1H-1, 2, 3-triazol-4-yl pyridine (3TYP), MV was not able to reduce ROS levels, reverse abnormal MMP, or decrease apoptotic cells. Motor impairments and dopaminergic neuronal injury in the SN were alleviated with the oral administration of MV in Rot-treated PD mice, indicating a relationship between protection against defective motility and preservation of dopaminergic neurons. Therefore, we conclude that MV can alleviate Rot-induced neurotoxicity in a PD model, and that SIRT3 may be an important regulator in the protection of MV.

Harmine suppresses breast cancer cell migration and invasion by regulating TAZ-mediated epithelial-mesenchymal transition.

Breast cancer is a highly lethal disease due to cancer metastasis. Harmine (HM), a ß-carboline alkaloid, is present in various medicinal plants. Our previous study demonstrated that HM suppresses cell proliferation and migration by regulating TAZ in breast cancer cells and accelerates apoptosis. Epithelial-mesenchymal transition (EMT) plays an important role in the development of breast cancer by inducing the characteristics of cancer stem cells, cancer metastasis and recurrence. Overexpression of TAZ was shown to mediate EMT in breast cancer cells. We aimed to investigate whether HM inhibits EMT and metastasis of breast cancer cells by targeting TAZ. In this study, the cells treated with HM or with downregulated expression of TAZ showed an increase in epithelial markers and decrease in mesenchymal markers in breast cancer cells. Consistently, the breast cancer cells treated with HM or with downregulated expression of TAZ showed suppressed migration and proliferation. Moreover, TAZ overexpression reversed EMT and metastasis induced by HM in breast cancer cells. Thus, HM suppresses EMT and metastasis and invasion by targeting TAZ in breast cancer cells. HM can be used as an anticancer drug for breast cancer treatment and chemoprevention.

Protein phosphatase 2A facilitates axonogenesis by dephosphorylating CRMP2.

Protein phosphatase 2A (PP2A) is indispensable in development, and deficits of PP2A and deterioration of neuronal axons have been observed in several neurodegenerative disorders, but the direct link between PP2A and the neuronal axon development is still missing. Here, we show that PP2A is essential for axon development in transfected rat brain and the dissociated hippocampal neurons. Upregulation of PP2A catalytic subunit (PP2Ac) not only promotes formation and elongation of the functional axons but also rescues axon retardation induced by PP2A inhibition. PP2A can dephosphorylate collapsin response mediator protein-2 (CRMP2) that implements the axon polarization, whereas constitutive expression of phosphomimic-CRMP2 abrogates the effect of PP2A upregulation. We also demonstrate that PP2Ac is enriched in the distal axon of the hippocampal neurons. Our results reveal a mechanistic link between PP2A and axonogenesis/axonopathy, suggesting that upregulation of PP2A may be a promising therapeutic for some neurodegenerative disorders.

Relationship of adult neurogenesis with tau phosphorylation and GSK-3ß activity in subventricular zone.

Altered neurogenesis has been reported in Alzheimer disease (AD), the most common neurodegenerative disorder characterized with hyperphosphorylated tau and accumulation of ß-amyloid (Aß). Recent studies suggest that tau phosphorylation is essential for hippocampal neurogenesis, however, it is not known whether tau phosphorylation also play a role in neurogenesis of subventricular zone (SVZ), another main progenitor niche in the brain. Here, we examined the expression of phosphorylated tau (p-tau) in SVZ and analyzed the role of p-tau in adult SVZ neurogenesis. We found that the expression of p-tau increased during postnatal development and remains at a high level until adulthood, and the p-tau was colocalized with some SVZ neural precursors. However, up-regulating glycogen synthase kinase-3 (GSK-3), a crucial tau kinase, had no effect on SVZ neurogenesis in adult rat brain. The SVZ neurogenesis was also unaffected in tau knockout and human tau transgenic mice. These results suggest that tau phosphorylation and GSK-3 activation may not be essential for adult SVZ neurogenesis.

Silencing of LINC00284 inhibits cell proliferation and migration in oral squamous cell carcinoma by the miR-211-3p/MAFG axis and FUS/KAZN axis.

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide. Emerging evidence has suggested that long noncoding RNAs (lncRNAs) play vital roles in various biological processes of cancers, such as cell proliferation, migration, invasion, and apoptosis. As reported previously, long intergenic non-protein coding RNA 284 (LINC00284) is an important regulator in multiple cancers. However, the biological role, as well as regulatory mechanism of LINC00284 in OSCC, has not been investigated. In our study, RT-qPCR results indicated that LINC00284 was significantly upregulated in OSCC tissues and cells. Moreover, loss-of-function experiments demonstrated that LINC00284 downregulation suppressed cell proliferation and migration and facilitated cell apoptosis. Mechanistically, we found that LINC00284 sponged microRNA 211-3p (miR-211-3p) to upregulate MAF bZIP transcription factor G (MAFG) expression in OSCC cells. Additionally, LINC00284 interacted with FUS protein to increase KAZN mRNA stability. Functional assays showed that either MAFG or KAZN overexpression promoted the malignant behaviors of OSCC cells. Through a series of rescue assays, we found that the inhibitory effect of silencing LINC00284 on OSCC cells can be reversed by upregulated MAFG and KAZN. Overall, silencing LINC00284 inhibits the malignant characteristics of OSCC cells by downregulating MAFG and inhibiting the binding of FUS to KAZN mRNA.

Enhanced Inflammatory Reaction and Thrombosis in High-Fat Diet-Fed ApoE-/- Mice are Attenuated by Celastrol.

OBJECTIVE: High-fat diet (HFD) increases the risk of inflammatory reaction and acute arterial thrombosis. Celastrol has been confirmed to regulate inflammatory cytokine levels in atherosclerotic animal models. However, the anti-thrombotic effects of celastrol have remained to be fully demonstrated. The present study was performed to investigate the beneficial effect of celastrol in HFD-induced inflammatory reaction and thrombosis in apolipoprotein (apo)E-/- mice. MATERIALS AND METHODS: Thrombogenic mice model was established using HFD-fed apoE-/- mice. The levels of mRNA and protein were assayed by RT-qPCR and western blotting, respectively. Immunohistochemistry (IHC) staining was performed to measure the protein expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in the aortic endothelium of HFD-fed apoE-/- mice. RESULTS: The results demonstrated that the effect of HFD on inflammatory cytokines in mice with apoE-/- background was reversed by celastrol administration, and celastrol treatment inhibited the NOD-like receptor family, pyrin domain containing 3 (NLRP3)/caspase-1/interleukin-1ß signaling cascades in peripheral blood mononuclear cells from HFD-fed apoE-/- mice. In addition, HFD enhanced adenosine diphosphate-induced platelet aggregation in normal C57BL/6 and apoE-/- mice, while celastrol administration reversed this. Furthermore, celastrol inhibited the pro-thrombotic effects of HFD in apoE-/- mice, and the underlying mechanism was mediated, at least partially, through the suppression of matrix metalloproteinase-2 and -9 expression. CONCLUSIONS: Celastrol administration significantly attenuated HFD-induced inflammatory reaction, platelet aggregation and thrombosis in apoE-/- mice, and celastrol may be used as a drug for the prevention of HFD-induced inflammatory reaction and thrombus.

Application of Machine Learning and Weighted Gene Co-expression Network Algorithm to Explore the Hub Genes in the Aging Brain.

Aging is a major risk factor contributing to neurodegeneration and dementia. However, it remains unclarified how aging promotes these diseases. Here, we use machine learning and weighted gene co-expression network (WGCNA) to explore the relationship between aging and gene expression in the human frontal cortex and reveal potential biomarkers and therapeutic targets of neurodegeneration and dementia related to aging. The transcriptional profiling data of the human frontal cortex from individuals ranging from 26 to 106 years old was obtained from the GEO database in NCBI. Self-Organizing Feature Map (SOM) was conducted to find the clusters in which gene expressions downregulate with aging. For WGCNA analysis, first, co-expressed genes were clustered into different modules, and modules of interest were identified through calculating the correlation coefficient between the module and phenotypic trait (age). Next, the overlapping genes between differentially expressed genes (DEG, between young and aged group) and genes in the module of interest were discovered. Random Forest classifier was performed to obtain the most significant genes in the overlapping genes. The disclosed significant genes were further identified through network analysis. Through WGCNA analysis, the greenyellow module is found to be highly negatively correlated with age, and functions mainly in long-term potentiation and calcium signaling pathways. Through step-by-step filtering of the module genes by overlapping with downregulated DEGs in aged group and Random Forest classifier analysis, we found that MAPT, KLHDC3, RAP2A, RAP2B, ELAVL2, and SYN1 were co-expressed and highly correlated with aging.

Essential role of tau phosphorylation in adult hippocampal neurogenesis.

An increased hippocampal neurogenesis has been observed in Alzheimer disease (AD), the most common neurodegenerative disorder characterized with accumulation of ß-amyloid (Aß) and hyperphosphorylated tau (p-tau). Studies in transgenic mouse models suggest that the amyloidosis suppresses adult neurogenesis. Although emerging evidence links tau to neurodevelopment, the direct data regarding tau phosphorylation in adult neurogenesis is missing. Here, we found that the immature neurons, identified by doublecortin (DCX) and neurogenic differentiation factor (neuroD), were only immunoreactive to p-tau but not to the non-p-tau in adult rat brain and human patients with AD, and the p-tau was coexpressed temporally and spatially with DCX and neuroD in the hippocampal dentate gyrus (DG) of the rat brains during postnatal development. A correlative increase of immature neuron markers and tau phosphorylation was induced in rat hippocampal DG by upregulating glycogen synthase kinase-3 (GSK-3), a crucial tau kinase, and the increased neurogenesis was due to an enhanced proliferation but not survival or differentiation of the newborn neurons. The hippocampal neurogenesis was severely impaired in tau knockout mice and activation of GSK-3 in these mice did not rescue the deficits. These results reveal an essential role of tau phosphorylation in adult hippocampal neurogenesis. It suggests that spatial/temporal manipulation of tau phosphorylation may be compensatory for the neuron loss in neurological disorders, including AD.

Knockdown of long non-coding RNA PVT1 protects human AC16 cardiomyocytes from hypoxia/reoxygenation-induced apoptosis and autophagy by regulating miR-186/Beclin-1 axis.

Myocardial ischemia/reperfusion (I/R) injury is a common consequence of restored blood supply after acute myocardial infarction (AMI), but its underlying mechanisms remain largely elusive. In this study, we aimed to investigate the functional role of long non-coding RNA PVT1 in hypoxia/reoxygenation (H/R)-treated AC16 cardiomyocytes. Our experimental results demonstrated that H/R treatment impaired the viability and increased the apoptosis of AC16 cells, and knockdown of PVT1 blocked the H/R injury. Besides, PVT1 knockdown also reduced excessive autophagy in H/R-treated AC16 cells. Furthermore, we confirmed that PVT1 might serve as a ceRNA for miR-186 in AC16 cells, and rescue experiments showed that miR-186 inhibition blocked the effects of PVT1 knockdown in H/R-treated AC16 cells. In summary, this study implied that PVT1 might be a promising therapeutic target for treating myocardial I/R injury.

Inhibition of autophagy causes tau proteolysis by activating calpain in rat brain.

The autophagic lysosomal system contributes to the removal of cytosolic components, and abnormality of lysosomal proteases has been reported in the brain of patients with Alzheimer's disease (AD). However, the role of lysosome in tau degradation is still elusive. Here, we infused chloroquine, 3-methyladenine or rapamycin into rat hippocampus or the lateral ventricle to manipulate the autophagic activity and measured the levels of tau protein by Western blotting. We unexpectedly observed that the level of different tau species decreased upon inhibition of lysosomal proteases or macroautophagy by chloroquine or 3-methyladenine. Furthermore, induction of autophagic activity by rapamycin did not induce degradation of tau proteins. To explore the underlying mechanisms for the increased tau degradation induced by autophagic inhibition, we used MG-132, an inhibitor of proteasome and calpain. We found that simultaneous inhibition of proteasome and calpain by MG-132 prevented the chloroquine-induced tau degradation. Further studies demonstrated that the activity of calpain was elevated whereas the activity of proteasome was suppressed in response to inhibition of autophagy by 3-methyladenine or chloroquine. Our data suggest that the lysosomal autophagic system may not degrade tau in the normal adult rat brain and inhibition of autophagy may induce tau proteolysis through activating calpain.

Comparison of long non­coding RNA expression profiles in human dental follicle cells and human periodontal ligament cells.

The dental follicle develops into the periodontal ligament, cementum and alveolar bone. Human dental follicle cells (hDFCs) are the precursor cells of periodontal development. Long non­coding RNAs (lncRNAs) have been revealed to be crucial factors that regulate a variety of biological processes; however, whether lncRNAs serve a role in human periodontal development remains unknown. Therefore, the present study used microarrays to detect the differentially expressed lncRNAs and mRNAs between hDFCs and human periodontal ligament cells (hPDLCs). A total of 845 lncRNAs and 1,012 mRNAs were identified to be differentially expressed in hDFCs and hPDLCs (fold change >2.0 or <­2.0; P<0.05). Microarray data were validated by reverse transcription­quantitative polymerase chain reaction. Bioinformatics analyses, including gene ontology, pathway analysis and coding­non­coding gene co­expression network analysis, were performed to determine the functions of the differentially expressed lncRNAs and mRNAs. Bioinformatics analysis identified that a number of pathways may be associated with periodontal development, including the p53 and calcium signaling pathways. This analysis also revealed a number of lncRNAs, including NR_033932, T152410, ENST00000512129, ENST00000540293, uc021sxs.1 and ENST00000609146, which may serve important roles in the biological process of hDFCs. In addition, the lncRNA termed maternally expressed 3 (MEG3) was identified to be differentially expressed in hDFCs by reverse transcription­quantitative polymerase chain reaction. The knockdown of MEG3 was associated with a reduction of pluripotency makers in hDFCs. In conclusion, for the first time, to the best of our knowledge, the current study determined the different expression profiles of lncRNAs and mRNAs between hDFCs and hPDLCs. The observations made may provide a solid foundation for further research into the molecular mechanisms of lncRNAs in human periodontal development.