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Alzheimer's disease (AD), the most common contributor to dementia, is a growing global health problem. This study aimed to investigate the role of lemur tyrosine kinase 2 (LMTK2) in AD as well as its relevant mechanism. To establish an in vitro cell model, PC12 cells were challenged with 20 µmol/l Ab 25-35 for 24 h. RT-qPCR and western blot examined LMTK2 mRNA and protein expressions. With the application of CCK-8, TUNEL, iron colorimetric assay kit and DCFH-DA, the viability, apoptosis, Fe 2+ and ROS content in PC12 cells were assessed. Besides, the expressions of oxidative stress-, apoptosis-, ferroptosis- and Nrf2/ARE signalling-related proteins were evaluated with western blot. Moreover, commercial kits examined SOD, MDA and CAT contents. The results manifested that LMTK2 expression was noticeably downregulated in Ab 25-35 -treated PC12 cells. Notably, LMTK2 overexpression exhibited inhibitory effects on oxidative stress, apoptosis and ferroptosis in PC12 cells exposed to Ab 25-35 . The upregulated Nrf2, NQO1 and HO-1 expressions in LMTK2 overexpressed-PC12 cells with Ab 25-35 induction revealed that LMTK2 overexpression could activate the Nrf2/ARE signalling pathway. What is more, a series of cellular experiments further testified that ML385, a specific Nrf2 inhibitor, partly hindered the protective role of LMTK2 overexpression against Ab 25-35 -triggered oxidative stress, apoptosis and ferroptosis in PC12 cells. In conclusion, LMTK2 overexpression alleviated the ferroptosis, oxidant damage and apoptosis in PC12 cells exposed to Ab 25-35 through the activation of the Nrf2/ARE signalling pathway, indicating the potential target of LMTK2 in the treatment of AD.

Cuproptosis is a novel copper ion-dependent cell death type being regulated in cells, and this is quite different from the common cell death patterns such as apoptosis, pyroptosis, necroptosis, and ferroptosis. Interestingly, like with death patterns, cuproptosis-related genes have recently been reported to regulate the occurrence and progression of various tumors. However, in bladder cancer, the link between cuproptosis and clinical outcome, tumor microenvironment (TME) modification, and immunotherapy is unknown. To determine the role of cuprotosis in the tumor microenvironment, we systematically examined the characteristic patterns of 10 cuproptosis-related genes in bladder cancer (BLCA). By analyzing principal component data, we established a cuproptosis score to determine the degree of cuproptosis among patients. Finally, we evaluated the potential of these values in predicting BLCA prognosis and treatment responses. A comprehensive study of the mutations of cuproptosis-related genes in BLCA specimens was conducted at the genetic level, and their expression and survival patterns were evaluated using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Two cuproptosis patterns were constructed based on the transcription level of 10 cuproptosis-related genes, featuring differences in the prognosis and the infiltrating landscape of immune cells (especially T and dendritic cells) with interactions between cuproptosis and the TME. Our study further demonstrated that cuproptosis score may predict prognosis, immunophenotype sensitivity to chemotherapy, and immunotherapy response among bladder cancer patients. The development and progression of bladder cancer are likely to be influenced by cuproptosis, which may involve a diverse and complex TME. The cuproptosis pattern evaluated in our study may enhance understanding of immune infiltrations and guide more potent immunotherapy interventions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Song, Zhou, Shu and Fu.)

Background: Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors all over the world. In recent years, long non-coding RNAs (lncRNAs) have been proven to participate in the development of different cancers, including NSCLC. PCGEM1 prostate-specific transcript (PCGEM1) is the lncRNA which is associated with the progression of several cancers. Nevertheless, in NSCLC, the specific functions of PCGEM1 are not yet clear., Methods: The real-time quantitative polymerase chain reaction (qPCR) was utilized to test the expression of PCGEM1 in NSCLC cells. Functional experiments, including cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry analysis and transwell assays were utilized to estimate cell proliferation, migration, invasion and apoptosis. Meanwhile, RNA pull down assay and luciferase reporter assay were utilized to evaluate the correlation of miR-433-3p with PCGEM1 or WT1 associated protein (WTAP)., Result: PCGEM1 was highly expressed in NSCLC cells, while miR-433-3p was lowly expressed in NSCLC cells. PCGEM1 silencing or miR-433-3p overexpression inhibited cell proliferation, migration and invasion but accelerated cell apoptosis. MiR-433-3p was proven be sponged by PCGEM1. Besides, WTAP was the target of miR-433-3p and it accelerated the progression of NSCLC. In the end, rescue experiments indicated that overexpression of WTAP or knockdown of miR-433-3p reversed the inhibited roles of silencing PCGEM1 on cell behavior., Conclusions: PCGEM1 accelerates NSCLC progression via sponging miR-433-3p to upregulate WTAP.

Introduction: Rare-earth nanoparticles in the environment and human body pose a potential threat to human health. Although toxic effects of rare-earth nanoparticles have been extensively studied, the effects on the early development are not well understood. In this study, we attempted to explain the toxic effects of neodymium oxide (Nd 2 O 3 ) nanoparticles on early development., Methods: We added the Nd 2 O 3 nanoparticles at different concentrations and recorded the mortality and malformation rate per 24 hrs under a microscope. The live embryos treated with Nd 2 O 3 nanoparticles were imaged as movies and Z step lapses with a confocal microscope, and heart rates were counted for 30 s to measure the cardiac function. The live Tg ( Flk1 :EGFP) transgenic embryos exposed to Nd 2 O 3 nanoparticles were observed under confocal microscope to measure the cerebrovascular development. Subsequently, we extracted the total protein for Western blot at 5 days post-fertilisation (dpf). Embryos were collected to undergo TUNEL staining for apoptosis detection., Results: Nd 2 O 3 nanoparticles disturbed embryo development at high concentrations (>200 μg/mL). The mortality and malformation rate gradually increased in a dose-dependent manner by morphological observation, while the Nd 2 O 3 median lethal concentration (LD50) was 203.4 μg/mL at 120 hrs post-fertilisation (hpf). Furthermore, the Nd 2 O 3 -treated embryos showed severe arrhythmia and reduced heart rate. We also observed the markedly cerebrovascular disappearance at middle concentration (100 and 200 μg/mL). The downregulated autophagy flux in brain blood vessels and increased apoptosis level in neurons might affect vessels sprouting and contribute to the vanished cerebrovascular., Conclusion: The results suggested that the embryos exposed to Nd 2 O 3 activated the apoptosis pathway and induced toxicity and abnormal cardiac/cerebrovascular development., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Chen et al.)

Background: Less apoptosis and excessive growth of fibroblasts contribute to the progression of hypertrophic scar formation. Cuprous oxide nanoparticles (CONPs) could have not only inhibited tumor by inducing apoptosis and inhibiting proliferation of tumor cells, but also promoted wound healing. The objective of this study was to further explore the therapeutic effects of CONPs on hypertrophic scar formation in vivo and in vitro., Methods: In vivo, a rabbit ear scar model was established on New Zealand albino rabbits. Six full-thickness and circular wounds (10 mm diameter) were made to each ear. Following complete re-epithelization observed on postoperative day 14, an intralesional injection of CONPs or 5% glucose solution was conducted to the wounds. The photo and ultrasonography of each wound were taken every week and scars were harvested on day 35 for further histomorphometric analysis. In vitro, the role of CONPs in human hypertrophic scar fibroblasts (HSFs) apoptosis and proliferation were evaluated by Tunnel assay, Annexin V/PI staining, cell cycle analysis, and EdU proliferation assay. The endocytosis of CONPs by fibroblasts were detected through transmission electron microscopy (TEM) and the mitochondrial membrane potential and ROS production were also detected., Results: In vivo, intralesional injections of CONPs could significantly improve the scar appearance and collagen arrangement, and decreased scar elevation index (SEI). In vitro, CONPs could prominently inhibit proliferation and induce apoptosis in HSFs in a concentration-dependent manner. In addition, CONPs could be endocytosed into mitochondria，damage the mitochondrial membrane potential and increase ROS production., Conclusion: CONPs possessed the therapeutic potential in the treatment of hypertrophic scar by inhibiting HSFs proliferation and inducing HSFs apoptosis., Competing Interests: The authors declare no conflicts of interest in this work.

Bacterial quorum-sensing autoinducers are small chemicals released to control microbial community behaviours. N-(3-oxo-dodecanoyl) homoserine lactone, the autoinducer of the Pseudomonas aeruginosa LasI-LasR circuitry, triggers significant cell death in lymphocytes. We found that this molecule is incorporated into the mammalian plasma membrane and induces dissolution of eukaryotic lipid domains. This event expels tumour necrosis factor receptor 1 into the disordered lipid phase for its spontaneous trimerization without its ligand and drives caspase 3-caspase 8-mediated apoptosis. In vivo, P. aeruginosa releases N-(3-oxo-dodecanoyl) homoserine lactone to suppress host immunity for its own better survival; conversely, blockage of caspases strongly reduces the severity of the infection. This work reveals an unknown communication method between microorganisms and the mammalian host and suggests interventions of bacterial infections by intercepting quorum-sensing signalling.

Glomerular mesangial cell (MC) apoptosis is one of the important mechanisms of glomerulosclerosis, which induces an increased severity of albuminuria and promotes the development of diabetic nephropathy (DN). However, the mechanism by which high glucose (HG) induces MCs apoptosis is not fully understood. In the present study, we investigated the effects of mTOR signalling on apoptosis in cultured MCs exposed to HG and in type I diabetes, and tried to clarify the specific mechanisms underlying these effects. In vitro, exposure of MCs to HG stimulated ROS production, decreased the antioxidant enzyme superoxide dismutase (SOD) activity and glutathione (GSH) level, increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, upregulated P53 expression and Bax/Bcl-2 ratio and enhanced cleavage of caspase 3, resulting in an increase in programmed cell death. Pretreatment of the cells with rapamycin ameliorated oxidative stress, reduced the number of apoptotic cells induced by HG and caused the downstream effects of mTOR activation. In vivo, compared with control rats, diabetic rats had more apoptotic cells in glomeruli. Induction of diabetes increased the level of MDA and NADPH oxidase activity, decreased the SOD activity and GSH level, elevated the Bax/Bcl ratio and P53 expression and activated caspase 3. mTOR inhibitor rapamycin treatment prevented these changes further alleviated albuminuria and improved renal function. Taken together, our data suggest that mTOR plays a key role in mediating ROS-induced MC apoptosis in diabetic nephropathy, and these effects have been associated with the promotion of ROS production by upregulating the antioxidant enzyme and downregulating the NADPH oxidase activity., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Expression of the RNA-binding protein HnRNP-L was previously shown to associate with tumorigenesis in liver and lung cancer. In this study, we examined the role of HnRNP-L in prostate cancer (Pca). We found that HnRNP-L is overexpressed in prostate tissue samples from 160 PC patients compared with tissue samples from 32 donors with cancers other than Pca. Moreover, HnRNP-L positively correlated with aggressive tumor characteristics. HnRNP-L knockdown inhibited cell proliferation and promoted cell apoptosis of Pca cell lines in vitro, and suppressed tumor growth when the cells were subcutaneously implanted in an athymic mouse model. Conversely, overexpression of HnRNP-L promoted cell proliferation and tumor growth while prohibiting cell apoptosis. HnRNP-L promoted cell proliferation and tumor growth in Pca in part by interacting with endogenous p53 mRNA, which was closely associated with cyclin p21. In addition, HnRNP-L affected cell apoptosis by directly binding the classical apoptosis protein BCL-2. These observations suggest HnRNP-L is an important regulatory factor that exerts pro-proliferation and anti-apoptosis effects in Pca through actions affecting the cell cycle and intrinsic apoptotic signaling. Thus HnRNP-L could potentially serve as a valuable molecular biomarker or therapeutic target in the treatment of Pca.

Recent studies have reported that caspase 7 has an apoptotic and nonapoptotic function. However, the relationship between caspase 7 and spermatogenesis remains unknown. This study aimed to investigate the possible function of caspase 7 during normal and abnormal spermatogenesis. The cleaved form of caspase 7 was detected in testis tissues at different postpartum times (5-14 weeks) by qRT-PCR, Western blot and immunohistochemistry (IHC). Then, the mice models of spermatogenic dysfunction were obtained by busulfan (30 mg kg-1 to further evaluate the potential function and mechanism of caspase 7. qRT-PCR and Western blot results showed that caspase 7 expression was gradually elevated from 5 to 14 weeks, which was not connected with apoptosis. IHC results revealed that caspase 7 was mainly located in spermatogenic cells and Leydig cells. In addition, spermatogenic dysfunction induced by busulfan gradually enhanced the apoptosis and elevated the expression of caspase 3, caspase 6, and caspase 9, but decreased the expression of caspase 7 in spermatogenic cells. However, when spermatogenic cells were mostly disappeared at the fourth week after busulfan treatment, caspase 7 expression in Leydig cells was significantly increased and positively correlated with the expression of caspase 3, caspase 6, and caspase 9. Therefore, these results indicate that caspase 7 has a nonapoptic function that participates in normal spermatogenesis, but also displays apoptotic function in spermatogenic dysfunction.

Purpose: Sertoli-cell only syndrome is one of the reasons for male infertility but its pathogenesis remains unclear. PRPS2, a subset of PRS, is reported to be a potential protein associated with Sertoli-cell only syndrome. In this study we further investigated the correlation between PRPS2 and Sertoli-cell only syndrome, and evaluated the effect of PRPS2 expression on apoptosis of TM4 Sertoli cells., Materials and Methods: PRPS2 expression was detected in patients with Sertoli-cell only syndrome and normal spermatogenesis, and in Sertoli-cell only syndrome mouse models by immunohistochemistry, quantitative reverse transcription-polymerase chain reaction and Western blot. PRPS2 expression in TM4 Sertoli cells was then down-regulated and up-regulated by lentivirus vectors. The effect of PRPS2 expression on cell apoptosis and cell cycle transition was evaluated by flow cytometry., Results: PRPS2 expression in patients with Sertoli-cell only syndrome was significantly greater than in those with normal spermatogenesis. A significant increase in PRPS2 expression was observed in Sertoli-cell only syndrome mouse models. PRPS2 over expression significantly inhibited cell apoptosis and promoted cell cycle transition in TM4 Sertoli cells. However, PRPS2 down-regulation showed a reverse effect. Moreover, results revealed that PRPS2 over expression inhibited cell apoptosis via the p53/Bcl-2/caspase-9/caspase-3/caspase-6/caspase-7 signaling pathway., Conclusions: PRPS2 expression correlates with Sertoli-cell only syndrome and inhibits the apoptosis of TM4 Sertoli cells via the p53/Bcl-2/caspases signaling pathway., (Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Our previous study has shown that ampelopsin (AMP), a flavonol mainly found in Ampelopsis grossedentata, could induce cell death in human breast cancer cells via reactive oxygen species generation and endoplasmic reticulum (ER) stress pathway. Here, we examined whether autophagy is activated in AMP-treated breast cancer cells and, if so, sought to find the exact role and underlying molecular profile of autophagy in AMP-induced cell death. Our results showed that AMP treatment activated autophagy in MDA-MB-231 and MCF-7 breast cancer cells, as evidenced by the accumulation of autophagosomes, an increase of microtubule-associated protein 1 light chain 3 beta-2 (LC3B-II) and the conversion of LC3B-I to LC3B-II, the degradation of the selective autophagic target p62/SQSTM1, and the formation of green fluorescent protein (GFP)-LC3 puncta. Blockage of autophagy augmented AMP-induced cell death, suggesting that autophagy has cytoprotective effects. Meanwhile, AMP treatment suppressed Akt-mammalian target of rapamycin (mTOR) pathway as evidenced by dose- and time-dependent decrease of the phosphorylation of Akt, mTOR and ribosomal protein S6 kinase (p70S6K), whereas Akt activator insulin-like growth factor-1 (IGF-1) pretreatment partially restored Akt-mTOR pathway inhibited by AMP and decreased AMP-inuduced autophagy, signifying that AMP activated autophagy via inhibition of the Akt-mTOR pathway. Additionally, blocking ER stress not only reduced autophagy induction, but also alleviated inhibition of the Akt-mTOR pathway induced by AMP, suggesting that activation of ER stress was involved in induction of autophagy and inhibition of the Akt-mTOR pathway. Taken together, these findings indicate that AMP induces protective autophagy in human breast cancer cells through Akt-mTOR pathway via ER stress., (© 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.)

Methylating drugs such as temozolomide (TMZ) are widely used in the treatment of brain tumors including malignant glioblastoma. The mechanism of TMZ-induced glioblastoma cell death and apoptosis, however, is not fully understood. Here, we tested the potential involvement of AMP-activated protein kinase (AMPK) in this process. We found that methylating agents TMZ and N-methyl-N'-nitro-N-nitrosoguanidine induce AMPK activation in primary cultured human glioblastoma and glioblastoma cell lines. TMZ-induced O(6)-methylguanine production is involved in AMPK activation. O(6)-benzylguanine, an O(6)-methylguanine-DNA methyltransferase inhibitor, enhances TMZ-induced O(6)-methylguanine production, leading to enhanced reactive oxygen species production, which serves as an upstream signal for AMPK activation. Activation of AMPK is involved in TMZ-induced glioblastoma cell death and apoptosis. AMPK inhibitor (Compound C) or AMPKα siRNA knockdown inhibits TMZ-induced glioblastoma cell death and apoptosis, whereas AMPK activator 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside enhances it. In further studies, we found that activation of AMPK is involved in TMZ-induced p53 activation and subsequent p21, Noxa, and Bax up-regulation. Activation of AMPK by TMZ also inhibits mTOR complex 1 (mTORC1) signaling and promotes anti-apoptosis protein Bcl-2 down-regulation, which together mediate TMZ-induced pro-cell apoptosis effects. Our study suggests that activation of AMPK by TMZ contributes to glioblastoma cell apoptosis, probably by promoting p53 activation and inhibiting mTORC1 signaling.