mTOR Research Articles

The role of SIRT1 in autophagy and drug resistance: unveiling new targets and potential biomarkers in cancer therapy.

Cancer, the world's second leading cause of death after cardiovascular diseases, is characterized by hallmarks such as uncontrolled cell growth, metastasis, angiogenesis, hypoxia, and resistance to therapy. Autophagy, a cellular process that can both support and inhibit cancer progression, plays a critical role in cancer development and progression. This process involves the formation of autophagosomes that ultimately fuse with lysosomes to degrade cellular components. A key regulator of this process is Sirtuin 1 (SIRT1), which significantly influences autophagy. This review delves into the role of SIRT1 in modulating autophagy and its broader impacts on carcinogenesis. SIRT1 regulates crucial autophagy mediators, such as AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR), effectively promoting or suppressing autophagy. Beyond its direct effects on autophagy, SIRT1's regulatory actions extend to other cell death processes, including apoptosis and ferroptosis, thereby influencing tumor cell proliferation, metastasis, and chemotherapy responses. These insights underscore the complex interplay between SIRT1 and autophagy, with significant implications for cancer therapy. Targeting SIRT1 and its associated pathways presents a promising strategy to manipulate autophagy in cancer treatment. This review underscores the potential of SIRT1 as a therapeutic target, opening new avenues for enhancing cancer treatment efficacy.

Apigenin Ameliorates H2O2-Induced Oxidative Damage in Melanocytes through Nuclear Factor-E2-Related Factor 2 (Nrf2) and Phosphatidylinositol 3-Kinase (PI3K)/Protein Kinase B (Akt)/Mammalian Target of Rapamycin (mTOR) Pathways and Reducing the Generation of Reactive Oxygen Species (ROS) in Zebrafish

Background: Apigenin is one of the natural flavonoids found mainly in natural plants, as well as some fruits and vegetables, with celery in particular being the most abundant. Apigenin has antioxidant, anti-tumor, anti-inflammatory, and anticancer effects. In this research, we attempted to further investigate the effects of apigenin on the mechanism of repairing oxidative cell damage. The present study hopes to provide a potential candidate for abnormal skin pigmentation disorders. Methods: We used 0.4 mM H2O2 to treat B16F10 cells for 12 h to establish a model of oxidative stress in melanocytes, and then we gave apigenin (0.1~5 μM) to B16F10 cells for 48 h, and detected the expression levels of melanin synthesis-related proteins, dendritic regulation-related proteins, antioxidant signaling pathway- and Nrf2 signaling pathway-related proteins, autophagy, and autophagy-regulated pathways by immunoblotting using Western blotting. The expression levels of PI3K/Akt/mTOR proteins were measured by β-galactosidase staining and Western blotting for cellular decay, JC-1 staining for mitochondrial membrane potential, and Western blotting for mitochondrial fusion- and mitochondrial autophagy-related proteins. Results: Apigenin exerts antioxidant effects by activating the Nrf2 pathway, and apigenin up-regulates the expression of melanin synthesis-related proteins Tyr, TRP1, TRP2, and gp100, which are reduced in melanocytes under oxidative stress. By inhibiting the expression of senescence-related proteins p53 and p21, and delaying cellular senescence, we detected the mitochondrial membrane potential using JC-1, and found that apigenin improved the reduction in mitochondrial membrane potential in melanocytes under oxidative stress, and maintained the normal function of mitochondria. In addition, we further detected the key regulatory proteins of mitochondrial fusion and division, MFF, p-DRP1 (S637), and p-DRP1 (S616), and found that apigenin inhibited the down-regulation of fusion-associated protein, p-DRP1 (S637), and the up-regulation of division-associated proteins, MFF and p-DRP1 (S616), due to oxidative stress in melanocytes, and promoted the mitochondrial fusion and ameliorated the imbalance between mitochondrial division and fusion. We further detected the expression of fusion-related proteins OPA1 and Mitofusion-1, and found that apigenin restored the expression of the above fusion proteins under oxidative stress, which further indicated that apigenin promoted mitochondrial fusion, improved the imbalance between mitochondrial division and fusion, and delayed the loss of mitochondrial membrane potential. Apigenin promotes the expression of melanocyte autophagy-related proteins and the key mitochondrial autophagy proteins BNIP3L/Nix under oxidative stress, and activates the PINK1/Parkin signaling pathway by up-regulating the expression of autophagy-related proteins, as well as the expression of PINK1 and Parkin proteins, to promote melanocyte autophagy and mitochondrial autophagy. Conclusions: Apigenin exerts anti-melanocyte premature aging and detachment effects by promoting melanin synthesis, autophagy, and mitochondrial autophagy in melanocytes, and inhibiting oxidative cell damage and senescence.

Taraxacum Mongolicum Polysaccharides Reverses Mice Obesity via Activation of AKT/mTOR Pathway

Background/Objectives: The global prevalence of obesity and its associated health complications represent significant public health concerns. Plant polysaccharides have been demonstrated to possess a range of beneficial pharmacological effects. This experiment was designed to elucidate the mechanisms of dietary Taraxacum mongolicum polysaccharides involved in the regulation of obesity and fat browning. Methods: Male C57BL/6J mice were randomly divided into three groups: a control group, a high-fat diet (HFD) group, and an HFD group supplemented with 0.3% TMPs. The mice were fed their respective diets for 10 weeks, after which their body weight, food consumption, and serum lipid levels were measured. Histological analysis was performed to assess lipid deposition in adipose tissue and liver. Western blot was used to assess the expression of proteins involved in the AKT/mTOR pathway. Results: The results show that compared with the HFD group, the TMP supplementation group’s body-weight gain (12.17 ± 1.77) significantly decreased. TMPs also reduced serum levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol. Histological analysis showed that TMPs reduced lipid deposition in both adipose tissue and the liver. Conclusions: In addition, TMPs increased the expression of phosphorylated AKT and the mechanistic target of rapamycin (mTOR), indicating that TMPs exert their beneficial effects on lipid metabolism via the AKT/mTOR pathway.

LncRNA TUG1 regulates mir-34a-5p / SIRT6 to participate in benzene-induced hematotoxicity through PI3K / AKT /mTOR signaling pathway

LncRNA TUG1 plays pivotal roles in various diseases. However, its exact roles in benzene - induced hematotoxicity remain unclear. Herein, we aimed to investigate the role and mechanism of TUG1 in hematoxic injuries caused by benzene. In the current study, TUG1 was found dramatically decreased in WBCs of benzene exposure workers and negatively correlated with benzene exposure duration and urine SPMA. In vitro assays demonstrated that TUG1 overexpression attenuated 1,4-BQ-caused suppression of cell viability and proliferation, and promotion of ROS generation and apoptosis via PI3K/AKT/mTOR pathway. Bioinformatic prediction and molecular assay validated miR-34a-5p was negatively regulated by TUG1. The miR-34a-5p was upregulated in 1,4-BQ treated cells and downregulated in TUG1 overexpression cells. Moreover, miR-34a-5p upregulation partially reversed the protective effects of TUG1 overexpression on 1,4-BQ - caused cytotoxicity. Furthermore, SIRT6 was a downstream target gene of miR-34a-5p, whose expression was reduced in miR-34a-5p upregulation cells and elevated in TUG1 overexpression cells. Upregulated SIRT6 could counteract accelerated cytotoxicity mediated by miR-34a-5p upregulation after 1,4-BQ treatment. Taken together, our study revealed that the critical role of the TUG1/miR-34a-5p/SIRT6 axis in benzene-caused hematotoxicity, and provided scientific basis for further understanding the epigenetic regulatory mechanisms underlying benzene hematotoxicity.

Autophagy-associated biomarkers ULK2, UVRAG, and miRNAs miR-21, miR-126, and miR-374: Prognostic significance in glioma patients.

As the pioneering study from Pakistan, our research distinctly focuses on validating the roles of autophagy-associated genes and MicroRNAs (miRs) in the unique context of our population for glioma prognosis. The study delves into the nuanced interplay of autophagy within a miR-modulated environment, prompting an exploration of its potential impact on glioma development and survival. Employing real-time PCR (qPCR), we meticulously assessed the expression profiles of autophagy genes and miRs in glioma tissues, complemented by immunohistochemistry on Formalin-fixed paraffin-embedded tissues from the same patients. Our comprehensive statistical analyses, including the data normality hypothesis Shapiro-Wilk test, the Mann-Whitney U-test, Spearman correlation test, and Kaplan-Meier survival analysis, were tailored to unravel the intricate associations specific to low- and high-grade glioma within our population. Clinicopathological analysis revealed a predominance of male patients (66%) with a median age of 35 years. Glioblastoma (32%) and Astrocytoma (36%) were the most prevalent histopathological subtypes. Molecular analysis showed significant correlations between prognostic markers (Ki-67, IDH-1, p53) and clinicopathological factors, including age, histological type, radiotherapy, and chemotherapy. In high-grade glioma, increased expression of AKT and miR-21, coupled with reduced ULK2 and LC3 expression was distinctly observed. While correlation analysis identified a strong positive correlation between ULK2 and UVRAG, PTEN, miR-7, and miR-100 in low-grade glioma, unveiling distinctive molecular signatures unique to our study. Furthermore, a moderate positive correlation emerged between ULK2 and mTOR, miR-7, miR-30, miR-100, miR-204, and miR-374, also between miR-21 and miR-126. Similarly, a positive correlation appeared between ULK2 and AKT, LC3, PI3K, PTEN, ULK1, VPS34, mTOR, Beclin1, UVRAG, miR-7 and miR-374. AKT positively correlated with LC3, PI3K, PTEN, ULK1, VPS34, mTOR, Beclin1, UVRAG, miR-7, miR-30, miR-204, miR-374, miR-126 and miR-21 weakly correlated with AKT and miR-30 in high-grade glioma, providing further insights into the autophagy pathway within our population. The enrichment analysis for miR-21, miR-126, and miR-374 showed MAPK pathway as a common pathway along with Ras, PI3K, and mTOR pathway. The low ULK2, UVRAG, and miR-374 expression group exhibited significantly poor overall survival in glioma, while miR-21 over-expression indicated a poor prognosis in glioma patients, validating it in our population. This study provides comprehensive insights into the molecular landscape of gliomas, highlighting the dysregulation of autophagy genes ULK2, and UVRAG and the associated miR-21, miR-126 and miR-374 as potential prognostic biomarkers and emphasizing their unique significance in shaping survival outcomes in gliomas within the specific context of the Pakistani population.

Low protein diet protects the liver from Salmonella Typhimurium-mediated injury by modulating the mTOR/autophagy axis in macrophages

Western diets are the underlying cause of metabolic and liver diseases. Recent trend to limit the consumption of protein-rich animal products has become more prominent. This dietary change entails decreased protein consumption; however, it is still unknown how this affects innate immunity. Here, we studied the influence of a low protein diet (LPD) on the liver response to bacterial infection in mice. We found that LPD protects from Salmonella enterica serovar Typhimurium (S. Typhimurium)-induced liver damage. Bulk and single-cell RNA sequencing of murine liver cells showed reduced inflammation and upregulation of autophagy-related genes in myeloid cells in mice fed with LPD after S. Typhimurium infection. Mechanistically, we found reduced activation of the mammalian target of rapamycin (mTOR) pathway, whilst increased phagocytosis and activation of autophagy in LPD-programmed macrophages. We confirmed these observations in phagocytosis and mTOR activation in metabolically programmed human peripheral blood monocyte-derived macrophages. Together, our results support the causal role of dietary components on the fitness of the immune system.

Tumor Dormancy Within the Lymphovascular Embolus Is Regulated by Multiple Metabolism-signaling Pathways.

Recently, we demonstrated that cancer dormancy is initiated within the lymphovascular tumor embolus and consists of decreased proliferation and lower mammalian target of rapamycin (mTOR) activity. In the present study, we investigated other intersecting metabolism-signaling pathways that may ultimately determine whether the lymphovascular tumor embolus remains dormant or undergoes cell death. The present study exploited a singular patient-derived xenograft (PDX) of inflammatory breast cancer (Mary-X) that spontaneously forms high density spheroids, the in vitro equivalent of emboli. The AMPK metabolic checkpoint pathway, the mTOR nutrient-responsive cell growth pathway, the P13K/Akt intracellular quiescence regulating pathway, and the calpain-mediated E-cadherin proteolytic pathway responsible for spontaneous spheroid-genesis were also investigated, to determine their relative contributions to dormancy. The levels of phosphorylated AMPK proteins (AMPKα and β subunits) decreased gradually with the formation of MARY-X spheroids in vitro. Rapamycin down-regulated mTOR activity, yet dormancy persisted. LY294002, a PI3K/Akt inhibitor, completely abolished mTOR and induced spheroid disadherence and apoptosis. Compound C (AMPK inhibitor) up-regulated mTOR and induced spheroid disadherence and apoptosis. Increasing cellular metabolism led to cell death, even in enriched medium, whereas growing the spheroids in serum-free media (starvation) did not result in further mTOR inhibition, and dormancy was maintained. An increase in our understanding of dormancy from the standpoint of internal signaling pathways might ultimately provide clues to the external stimuli (starvation, hypoxia or other not yet understood phenomena) that act through these pathways to maintain or disrupt dormancy.

Antitumor Potential of Guttiferone E Combined With Carboplatin Against Osimertinib-resistant H1975 Lung Cancer Through Apoptosis.

Low selectivity and high frequency of side-effects are the major problems of currently used chemotherapeutics. Among natural compounds, the polyprenylated acylphloroglucinol, guttiferone E, isolated from Brazilian red propolis, has attracted attention due to its marked anticancer properties and was evaluated here for its role against osimertinib-resistant H1975 cells (with double mutations of epidermal growth factor receptor: EGFR L858R/T790M). Guttiferone E was obtained from red propolis using established extraction procedures. Guttiferone E was tested using the H1975 cell line in in vitro (2D and 3D) cell cultures and in vivo in BALB/c athymic nude mice. Live/dead assay was also performed to support the results. Tumor tissues obtained from in vivo studies were used for western blotting. Guttiferone E reduced H1975 cell viability in a concentration-dependent manner. The IC50 values in 2D and 3D cell lines were 2.56±0.12 μM and 11.25±0.34 μM. Furthermore, at 10 mg/kg intraperitoneally, guttiferone E significantly reduced the tumor volume in tumor xenografts when used alone and in combination with carboplatin. Guttiferone E and carboplatin displayed synergistic inhibition of H1975 cells and animal tumors. Co-treatment of guttiferone E with carboplatin induced more prominent apoptosis than treatment with either drug alone. Guttiferone E treatment induced cleavage of poly-ADP ribose polymerase and induced apoptosis by significantly reducing levels of mammalian target of rapamycin, sirtuin 1, sirtuin 7, superoxide dismutase, programmed death-ligand 1, and programmed cell death 1 in tumor tissues. Our results show guttiferone E to be a promising, novel and potent antitumor drug candidate for osimertinib-resistant lung cancer with EGFR L858R/T790M mutations.

Tuberous sclerosis complex: a case report

Background. Tuberous sclerosis complex (TSC) is a rare genetic disorder diagnosed in 6000-10000 children annually, marked by hamartomas in various organs due to hyperactivity of the mTOR pathway. Case report. A 9-year-old male with TSC exhibited developmental delays, skin lesions, vision and hearing impairments, and neurological symptoms. Extensive evaluations confirmed the diagnosis, and treatment included mTOR inhibitors, symptomatic management, and psychotherapy, resulting in condition improvement. Conclusions. TSC, caused by mutations in TSC1 and TSC2, significantly impacts organ function and quality of life, requiring comprehensive, multidisciplinary care.

Biology of Healthy Aging: Biological Hallmarks of Stress Resistance Related and Unrelated to Longevity in Humans

Stress resistance is highly associated with longer and healthier lifespans in various model organisms, including nematodes, fruit flies, and mice. However, we lack a complete understanding of stress resistance in humans; therefore, we investigated how stress resistance and longevity are interlinked in humans. Using more than 180 databases, we identified 541 human genes associated with stress resistance. The curated gene set is highly enriched with genes involved in the cellular response to stress. The Reactome analysis identified 398 biological pathways, narrowed down to 172 pathways using a medium threshold (p-value < 1 × 10−4). We further summarized these pathways into 14 pathway categories, e.g., cellular response to stimuli/stress, DNA repair, gene expression, and immune system. There were overlapping categories between stress resistance and longevity, including gene expression, signal transduction, immune system, and cellular responses to stimuli/stress. The categories include the PIP3-AKT-FOXO and mTOR pathways, known to specify lifespans in the model systems. They also include the accelerated aging syndrome genes (WRN and HGPS/LMNA), while the genes were also involved in non-overlapped categories. Notably, nuclear pore proteins are enriched among the stress-resistance pathways and overlap with diverse metabolic pathways. This study fills the knowledge gap in humans, suggesting that stress resistance is closely linked to longevity pathways but not entirely identical. While most longevity categories intersect with stress-resistance categories, some do not, particularly those related to cell proliferation and beta-cell development. We also note inconsistencies in pathway terminologies with aging hallmarks reported previously, and propose them to be more unified and integral.

Trained immunity of synovial macrophages is associated with exacerbated joint inflammation and damage after Staphylococcus aureus infection.

Investigate whether and which synoviocytes would acquire trained immunity characteristics that could exacerbate joint inflammation following a secondary Staphylococcus aureus infection. Lipopolysaccharide (LPS) and S. aureus were separately or double injected (21 days of interval) into the tibiofemoral joint cavity of male C57BL/6 mice. At different time points after these stimulations, mechanical nociception was analyzed followed by the analysis of signs of inflammation and damage in the affected joints. The trained immunity markers, including the glycolytic and mTOR pathway, were analyzed in whole tissue or isolated synoviocytes. A group of mice was treated with Rapamycin, an mTOR inhibitor before LPS or S. aureus stimulation. The double LPS - S. aureus hit promoted intense joint inflammation and damage compared to single joint stimulation, including markers in synoviocyte activation, production of proinflammatory cytokines, persistent nociception, and bone damage, despite not reducing the bacterial clearance. The double LPS - S. aureus hit joints increased the synovial macrophage population expressing CX3CR1 alongside triggering established epigenetic modifications associated with trained immunity events in these cells, such as the upregulation of the mTOR signaling pathway (p-mTOR and HIF1α) and the trimethylation of histone H3. Mice treated with Rapamycin presented reduced CX3CR1+ macrophage activation, joint inflammation, and bone damage. There is a trained immunity phenotype in CX3CR1+ synovial macrophages that contributes to the exacerbation of joint inflammation and damage during septic arthritis caused by S. aureus.

Molecular docking and dynamics simulation of farnesol as a potential anticancer agent targeting mTOR pathway.

Farnesol is a natural acyclic sesquiterpene alcohol, found in various essential oils such as, lemon grass, citronella, tuberose, neroli, and musk. It has a molecular mass of 222.372g/mol and chemical formula of C₁₅H₂₆O. The main objective of this study was to assess the effect of farnesol on mTOR and its two downstream effectors, p70S6K and eIF4E, which are implicated in the development of cancer, via molecular dynamic simulation, and docking analysis in an in silico study. A multilayer, primarily computer-based analysis was conducted to assess farnesol's anticancer potential, with a focus on primary cancer targets. From the calculations performed, farnesol showed a binding affinity of - 9.66kcal/mol, followed by binding affinity of - 7.4kcal/mol and - 7.8kcal/mol for mTOR, p70S6K and eIF4E respectively. Rapamycin showed the binding affinity of - 10.45kcal/mol for mTOR, for p70S6K and eIF4E the calculated binding affinity was - 10.65kcal/mol and 8.16kcal/mol respectively. The binding affinity of farnesol was comparable to the standard drug rapamycin indicating its potential as an mTOR inhibitor. Molecular dynamics simulations suggest that the ligands (farnesol and rapamycin) were well trapped within the active site of the protein over a time gap of 50 ns. It is clear that farnesol showed relatively stable MD simulation results, with minor fluctuations and maintains a consistent binding orientation, suggesting a strong and stable interaction with the target proteins when compared to simulation data of standard drug. This study explores the potential of farnesol as an anticancer agent through an in-silico approach, focusing on its interaction with mTOR and its downstream effectors. Inhibition of mTOR signaling pathway may be responsible for the anticancer effect of farnesol. As this pathway plays a crucial role in cell proliferation and survival, making it a significant target in cancer research.

Network Pharmacology and in vitro Experimental Verification on Intervention of Oridonin on Non-Small Cell Lung Cancer.

To explore the key target molecules and potential mechanisms of oridonin against non-small cell lung cancer (NSCLC). The target molecules of oridonin were retrieved from SEA, STITCH, SuperPred and TargetPred databases; target genes associated with the treatment of NSCLC were retrieved from GeneCards, DisGeNET and TTD databases. Then, the overlapping target molecules between the drug and the disease were identified. The protein-protein interaction (PPI) was constructed using the STRING database according to overlapping targets, and Cytoscape was used to screen for key targets. Molecular docking verification were performed using AutoDockTools and PyMOL software. Using the DAVID database, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted. The impact of oridonin on the proliferation and apoptosis of NSCLC cells was assessed using cell counting kit-8, cell proliferation EdU image kit, and Annexin V-FITC/PI apoptosis kit respectively. Moreover, real-time quantitative PCR and Western blot were used to verify the potential mechanisms. Fifty-six target molecules and 12 key target molecules of oridonin involved in NSCLC treatment were identified, including tumor protein 53 (TP53), Caspase-3, signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase kinase 8 (MAPK8), and mammalian target of rapamycin (mTOR). Molecular docking showed that oridonin and its key target molecules bind spontaneously. GO and KEGG enrichment analyses revealed cancer, apoptosis, phosphoinositide-3 kinase/protein kinase B (PI3K/Akt), and other signaling pathways. In vitro experiments showed that oridonin inhibited the proliferation, induced apoptosis, downregulated the expression of Bcl-2 and Akt, and upregulated the expression of Caspase-3. Oridonin can act on multiple targets and pathways to exert its inhibitory effects on NSCLC, and its mechanism may be related to upregulating the expression of Caspase-3 and downregulating the expressions of Akt and Bcl-2.

Rapamycin Treatment Reduces Brain Pericyte Constriction in Ischemic Stroke.

The contraction and subsequent death of brain pericytes may play a role in microvascular no-reflow following the reopening of an occluded artery during ischemic stroke. Mammalian target of rapamycin (mTOR) inhibition has been shown to reduce motility/contractility of various cancer cell lines and reduce neuronal cell death in stroke. However, the effects of mTOR inhibition on brain pericyte contraction and death during ischemia have not yet been investigated. Cultured pericytes exposed to simulated ischemia for 12 h in vitro contracted after less than 1 h, which was about 7 h prior to cell death. Rapamycin significantly reduced the rate of pericyte contraction during ischemia; however, it did not have a significant effect on pericyte viability at any time point. Rapamycin appeared to reduce pericyte contraction through a mechanism that is independent of changes in intracellular calcium. Using a mouse model of middle cerebral artery occlusion, we showed that rapamycin significantly increased the diameter of capillaries underneath pericytes and increased the number of open capillaries 30 min following recanalisation. Our findings suggest that rapamycin may be a useful adjuvant therapeutic to reduce pericyte contraction and improve cerebral reperfusion post-stroke.

Precision molecular insights for prostate cancer prognosis: tumor immune microenvironment and cell death analysis of senescence-related genes by machine learning and single-cell analysis

BackgroundProstate cancer (PCa) is a prevalent malignancy among men, primarily originating from the prostate epithelium. It ranks first in global cancer incidence and second in mortality rates, with a rising trend in China. PCa's subtle initial symptoms, such as urinary issues, necessitate diagnostic measures like digital rectal examination, prostate-specific antigen (PSA) testing, and tissue biopsy. Advanced PCa management typically involves a multifaceted approach encompassing surgery, radiation, chemotherapy, and hormonal therapy. The involvement of aging genes in PCa development and progression, particularly through the mTOR pathway, has garnered increasing attention.MethodsThis study aimed to explore the association between aging genes and biochemical PCa recurrence and construct predictive models. Utilizing public gene expression datasets (GSE70768, GSE116918, and TCGA), we conducted extensive analyses, including Cox regression, functional enrichment, immune cell infiltration estimation, and drug sensitivity assessments. The constructed risk score model, based on aging-related genes (ARGs), demonstrated superior predictive capability for PCa prognosis compared to conventional clinical features. High-risk genes positively correlated with risk, while low-risk genes displayed a negative correlation.ResultsAn ARGs-based risk score model was developed and validated for predicting prognosis in prostate adenocarcinoma (PRAD) patients. LASSO regression analysis and cross-validation plots were employed to select ARGs with prognostic significance. The risk score outperformed traditional clinicopathological features in predicting PRAD prognosis, as evidenced by its high AUC (0.787). The model demonstrated good sensitivity and specificity, with AUC values of 0.67, 0.675, 0.696, and 0.696 at 1, 3, 5, and 8 years, respectively, in the GEO cohort. Similar AUC values were observed in the TCGA cohort at 1, 3, and 5 years (0.67, 0.659, 0.667, and 0.743). The model included 12 genes, with high-risk genes positively correlated with risk and low-risk genes negatively correlated.ConclusionsThis study presents a robust ARGs-based risk score model for predicting biochemical recurrence in PCa patients, highlighting the potential significance of aging genes in PCa prognosis and offering enhanced predictive accuracy compared to traditional clinical parameters. These findings open new avenues for research on PCa recurrence prediction and therapeutic strategies.

Prenatal diagnosis in fetal right aortic arch using chromosomal microarray analysis and whole exome sequencing: a Chinese single-center retrospective study

BackgroundRight aortic arch (RAA) is a common congenital aortic arch abnormality. Fetuses with RAA frequently have good outcomes after birth. However, chromosomal abnormalities and genetic syndromes suggest poor prognosis for these patients. So far the underlying genetic etiology is still not identified in most RAA patients based on traditional genetic techniques and a problem is still debated whether fetuses with isolated RAA should be referred for CMA. Our study aims to investigate the genetic etiology of fetuses with right aortic arch (RAA) by chromosomal microarray analysis (CMA) and whole exome sequencing (WES) and evaluate the efficacy of CMA in fetal isolated RAA.ResultsAmong these 153 fetuses, 99 (64.7%) with isolated RAA and 54 (35.3%) with non-isolated RAA; 25.5% (39/153) with additional intracardiac anomalies (ICA), and 19.0% (29/153) with extracardiac anomalies (ECA). Tetralogy of Fallot (n = 10) and persistent left superior vena cava (n = 11) are the most common ICA and ECA, respectively. CMA detected 15 clinically significant copy number variations (CNVs) in 14 cases (9.2%); microdeletion of 22q11.21 was the most common pathogenic CNVs (7.8%). The chromosomal abnormalities rate was higher in non-isolated RAA and RAA with ICA groups than in isolated RAA group (16.7% vs. 5.1%; 20% vs. 5.1%, both p < 0.05). From five cases further undergoing WES, a diagnostic variant in MTOR gene (c.7255G > A, de novo) was first reported in prenatal, extending the prenatal manifestation of Smith–Kingsmore syndrome (OMIM: 616638); a clinically relevant variant c.3407A > T in STAG2 was identified, being inherited from the healthy mother. Moreover, the premature birth and termination rates were higher in non-isolated RAA group than in isolated RAA group (11.1% vs. 1.0%; 37.0% vs. 2.0%, both p < 0.01).ConclusionsWe demonstrate that CMA and WES are useful diagnostic tools for fetal RAA, particularly non-isolated RAA, and all fetuses with RAA should be referred for CMA. The data probably aids in prenatal diagnosis and prenatal counseling of fetal RAA.

Homocysteine metabolites impair the PHF8/H4K20me1/mTOR/autophagy pathway by upregulating the expression of histone demethylase PHF8-targeting microRNAs in human vascular endothelial cells and mice.

The inability to efficiently metabolize homocysteine (Hcy) due to nutritional and genetic deficiencies, leads to hyperhomocysteinemia (HHcy) and endothelial dysfunction, a hallmark of atherosclerosis which underpins cardiovascular disease (CVD). PHF8 is a histone demethylase that demethylates H4K20me1, which affects the mammalian target of rapamycin (mTOR) signaling and autophagy, processes that play important roles in CVD. PHF8 is regulated by microRNA (miR) such as miR-22-3p and miR-1229-3p. Biochemically, HHcy is characterized by elevated levels of Hcy, Hcy-thiolactone and N-Hcy-protein. Here, we examined the effects of these metabolites on miR-22-3p, miR-1229-3p, and their target PHF8, as well as on the downstream consequences of these effects on H4K20me1, mTOR-, and autophagy-related proteins and mRNAs expression in human umbilical vein endothelial cells (HUVEC). We found that treatments with N-Hcy-protein, Hcy-thiolactone, or Hcy upregulated miR-22-3p and miR-1229-3p, attenuated PHF8 expression, upregulated H4K20me1, mTOR, and phospho-mTOR. Autophagy-related proteins (BECN1, ATG5, ATG7, lipidated LC3-II, and LC3-II/LC3-I ratio) were significantly downregulated by at least one of these metabolites. We also found similar changes in the expression of miR-22-3p, Phf8, mTOR- and autophagy-related proteins/mRNAs invivo in hearts of Cbs-/- mice, which show severe HHcy and endothelial dysfunction. Treatments with inhibitors of miR-22-3p or miR-1229-3p abrogated the effects of Hcy-thiolactone, N-Hcy-protein, and Hcy on miR expression and on PHF8, H4K20me1, mTOR-, and autophagy-related proteins/mRNAs in HUVEC. Taken together, these findings show that Hcy metabolites upregulate miR-22-3p and miR-1229-3p expression, which then dysregulate the PHF8/H4K20me1/mTOR/autophagy pathway, important for vascular homeostasis.

Neuroprotective Effect of Melatonin in a Neonatal Hypoxia-Ischemia Rat Model Is Regulated by the AMPK/mTOR Pathway.

Melatonin has been shown to be neuroprotective in different animal models of neonatal hypoxic-ischemic brain injury. However, its exact molecular mechanism of action remains unknown. Our aim was to prove melatonin's short- and long-term neuroprotection and investigate its role on the AMPK (AMP-activated protein kinase)/mTOR (mammalian target of rapamycin) pathway following neonatal hypoxic-ischemic brain injury. Seven-day-old Wistar rat pups were exposed to hypoxia-ischemia, followed by melatonin or vehicle treatment. Detailed analysis of the AMPK/mTOR/autophagy pathway, short- and long-term neuroprotection, myelination, and oligodendrogenesis was performed at different time points. At 7 days after hypoxia-ischemia, melatonin-treated animals showed a significant decrease in tissue loss, increased oligodendrogenesis, and myelination. Long-term neurobehavioral results showed significant motor improvement following melatonin treatment. Molecular pathway analysis showed a decrease in the AMPK expression, with a significant increase at mTOR's downstream substrates, and a significant decrease at the autophagy marker levels in the melatonin group compared with the vehicle group. Melatonin treatment reduced brain area loss and promoted oligodendrogenesis with a clear improvement of motor function. We found that melatonin associated neuroprotection is regulated via the AMPK/mTOR/autophagy pathway. Considering the beneficial effects of melatonin and the results of our study, melatonin seems to be an optimal candidate for the treatment of newborns with hypoxic-ischemic brain injury in high- as well as in low- and middle-income countries.

Enhancement of cognitive function in mice with Alzheimer's disease through hyperbaric oxygen-induced activation of cellular autophagy.

In this study, we examined the effectiveness of hyperbaric oxygen (HBO) therapy in ameliorating cognitive deficits in mice with Alzheimer's disease (AD), while also assessing its impact on the autophagic pathway within the context of AD. 20 double-transgenic mice expressing the amyloid precursor protein and presenilin 1 (APP/PS1) were purposefully selected and randomly assigned to groups A and B. Concurrently, 20 C57BL/6 mice were chosen and randomly categorized into groups C and D, each consisting of 10 mice. Mice in groups B and D received HBO treatment. The Morris water maze assay was used to assess changes in mouse behavior. Immunohistochemistry techniques were used to quantify the expression levels of amyloid-beta 42 (Aβ42) and microtubule-associated protein 1A/1B-light chain 3 (LC3) in hippocampal tissues, while western blot analysis was used to investigate the levels of LC3-II, p62, phosphoinositide 3-kinase (PI3K), and mammalian target of rapamycin (mTOR) proteins within hippocampal tissues. Mice allocated to group B exhibited reduced escape latency and prolonged dwell time in the target quadrant compared to other groups. Histological examination revealed conspicuous plaque-like deposits of Aβ42 in the hippocampal tissues of mice in groups A and B. Group B displayed diminished Aβ42-positive reactants and augmented microtubule-associated protein 1A/1B-LC3-positive reactants compared to group A. LC3-positive reactants were also detected in the hippocampal tissues of mice in groups C and D, surpassing the levels observed in groups A and B. Furthermore, group B demonstrated significantly lower expression of mTOR protein and markedly higher expression of LC3-II protein in mouse hippocampal tissues when compared to group A (P < 0.05). Conversely, there were no significant disparities noted in PI3K and p62 protein expression between groups B and A. Notably, no discernible discrepancies were observed in the expression levels of mTOR, PI3K, LC3-II, and p62 proteins between groups C and D within mouse hippocampal tissues. HBO treatment demonstrates efficacy in enhancing cognitive function in mice with AD and holds promise as a potential therapeutic intervention for AD by facilitating the activation of the mTOR pathway-mediated autophagy.

Dysregulated mTOR networks in experimental sporadic Alzheimer's disease.

Beyond the signature amyloid-beta plaques and neurofibrillary tangles, Alzheimer's disease (AD) has been shown to exhibit dysregulated metabolic signaling through insulin and insulin-like growth factor (IGF) networks that crosstalk with the mechanistic target of rapamycin (mTOR). Its broad impact on brain structure and function suggests that mTOR is likely an important therapeutic target for AD. This study characterizes temporal lobe (TL) mTOR signaling abnormalities in a rat model of sporadic AD neurodegeneration. Long Evans rats were given intracerebroventricular injections of streptozotocin (ic-STZ) or saline (control), and 4 weeks later, they were administered neurobehavioral tests followed by terminal harvesting of the TLs for histopathological study and measurement of AD biomarkers, neuroinflammatory/oxidative stress markers, and total and phosphorylated insulin/IGF-1-Akt-mTOR pathway signaling molecules. Rats treated with ic-STZ exhibited significantly impaired performance on Rotarod (RR) and Morris Water Maze (MWM) tests, brain atrophy, TL and hippocampal neuronal and white matter degeneration, and elevated TL pTau, AβPP, Aβ, AChE, 4-HNE, and GAPDH and reduced ubiquitin, IL-2, IL-6, and IFN-γ immunoreactivities. In addition, ic-STZ reduced TL pY1135/1136-IGF-1R, Akt, PTEN, pS380-PTEN, pS2448-mTOR, p70S6K, pT412-p70S6K, p/T-pT412-p70S6K, p/T-Rictor, and p/T-Raptor. Experimental ic-STZ-induced sporadic AD-type neurodegeneration with neurobehavioral dysfunctions associated with inhibition of mTOR signaling networks linked to energy metabolism, plasticity, and white matter integrity.