Levels Of Autophagy-related Proteins Research Articles

Protective effects of CY-09 and astaxanthin on NaIO3-induced photoreceptor inflammation via the NLRP3/autophagy pathway.

To study the effect of the NLRP3/autophagy pathway on the photoreceptor inflammatory response and the protective mechanism of CY-09 and astaxanthin (AST). ICR mice were intraperitoneally injected NaIO3, CY-09, AST successively and divided into 5 groups, including the control, NaIO3, NaIO3+CY-09, NaIO3+AST, and NaIO3+CY-09+AST groups. Spectral domain optical coherence tomography and flash electroretinogram were examined and the retina tissues were harvested for immunohistochemistry, enzyme linked immunosorbent assay (ELISA), and Western blotting. Retinal pigment epithelium cell line (ARPE-19 cells) and mouse photoreceptor cells line (661W cells) were also treated with NaIO3, CY-09, and AST successively. Cell proliferation was assessed by cell counting kit-8 (CCK-8) assay. Apoptosis was analyzed by flow cytometry. Changes in autophagosome morphology were observed by transmission electron microscopy. Quantitative polymerase chain reaction (qPCR) was used to detect NLRP3 and caspase-1. NLRP3, caspase-1, cleaved caspase-1, p62, Beclin-1, and LC3 protein levels were measured by Western blotting. IL-1β and IL-18 were measured by ELISA. Compared with the control group, the activity of NaIO3-treated 661W cells decreased within 24 and 48h, apoptosis increased, NLRP3, caspase-1, IL-1β and IL-18 levels increased, and autophagy-related protein levels increased (P<0.05). Compared with NaIO3 group, CY-09 and AST inhibited apoptosis (P<0.05), reduced NLRP3, caspase-1, IL-1β and IL-18 expression (P<0.05), and inhibited autophagy. Compared with the other groups, CY-09 combined with AST significantly decreased NLRP3 expression and inhibited the expression of the autophagy-related proteins p62, Beclin-1, and LC3 in vitro and in vivo (P<0.05). CY-09 and AST inhibit NaIO3-induced inflammatory damage through the NLRP3/autophagy pathway in vitro and in vivo. CY-09 and AST may protect retina from inflammatory injury.

Melatonin alleviates autophagy in cortical neurons of neonatal rats with hypoxic- ischemic brain damage via the PI3K/AKT pathway

To observe the effects of melatonin on autophagy in cortical neurons of neonatal rats with hypoxic-ischemic brain damage (HIBD) and to explore its mechanisms via the PI3K/AKT signaling pathway, aiming to provide a basis for the clinical application of melatonin. Seven-day-old Sprague-Dawley neonatal rats were randomly divided into a sham operation group, an HIBD group, and a melatonin group (n=9 each). The neonatal rat HIBD model was established using the classic Rice-Vannucci method. Neuronal morphology in the neonatal rat cerebral cortex was observed with hematoxylin-eosin staining and Nissl staining. Autophagy-related protein levels of microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 were detected by immunofluorescence staining and Western blot analysis. Phosphorylated phosphoinositide 3-kinase (p-PI3K) and phosphorylated protein kinase B (p-AKT) protein expression levels were measured by immunohistochemistry and Western blot. The correlation between autophagy and the PI3K pathway in the melatonin group and the HIBD group was analyzed using Pearson correlation analysis. Twenty-four hours post-modeling, neurons in the sham operation group displayed normal size and orderly arrangement. In contrast, neurons in the HIBD group showed swelling and disorderly arrangement, while those in the melatonin group had relatively normal morphology and more orderly arrangement. Nissl bodies were normal in the sham operation group but distorted in the HIBD group; however, they remained relatively intact in the melatonin group. The average fluorescence intensity of LC3 and Beclin-1 was higher in the HIBD group compared to the sham operation group, but was reduced in the melatonin group compared to the HIBD group (P<0.05). The number of p-PI3K+ and p-AKT+ cells decreased in the HIBD group compared to the sham operation group but increased in the melatonin group compared to the HIBD group (P<0.05). LC3 and Beclin-1 protein expression levels were higher, and p-PI3K and p-AKT levels were lower in the HIBD group compared to the sham operation group (P<0.05); however, in the melatonin group, LC3 and Beclin-1 levels decreased, and p-PI3K and p-AKT increased compared to the HIBD group (P<0.05). The correlation analysis results showed that the difference of the mean fluorescence intensity of LC3 and Beclin-1 protein in the injured cerebral cortex between the melatonin and HIBD groups was negatively correlated with the difference of the number of p-PI3K+ and p-AKT+ cells between the two groups (P<0.05). Melatonin can inhibit excessive autophagy in cortical neurons of neonatal rats with HIBD, thereby alleviating HIBD. This mechanism is associated with the PI3K/AKT pathway.

γ-Mangosteen, an autophagy enhancer, prevents skin-aging via activating KEAP1/NRF2 signaling and downregulating MAPKs/AP-1/NF-κB-mediated MMPs

BackgroundMangosteens, a naturally occurring xanthones, found abundantly in mangosteen fruits. The anti-skin aging potential of γ-mangosteen (GM) remains unexplored; therefore, we investigated the UVB-induced anti-skin aging of GM via activation of autophagy. HypothesisWe hypothesized that GM exerts antioxidant and anti-aging capabilities both in vitro and in vivo through activation of autophagy as well as control of KEAP1/NRF2 signaling and MAPKs/AP-1/NF-κB-mediated MMPs pathways. MethodsThe anti-skin aging effects of GM were studied using HDF cells and a mice model. Various assays, such as DPPH, ABTS, CUPRAC, FRAP, and ROS generation, assessed antioxidant activities. Kits measured antioxidant enzymes, SA-β-gal staining, collagen, MDA content, si-RNA experiments, and promoter assays. Western blotting evaluated protein levels of c-Jun, c-Fos, p-IκBα/β, p-NF-κB, MAPK, MMPs, collagenase, elastin, KEAP1, NRF2, HO-1, and autophagy-related proteins. ResultsGM exhibited strong antioxidant, collagenase and elastase enzyme inhibition activity surpassing α- and β-mangosteen. GM competitively inhibited elastase with a Ki value of 29.04 µM. GM orchestrated the KEAP1-NRF2 pathway, enhancing HO-1 expression, and suppressed UVB-induced ROS in HDF cells. NRF2 knockdown compromised GM's antioxidant efficacy, leading to uncontrolled ROS post-UVB. GM bolstered endogenous antioxidants, curbing lipid peroxidation in UVB-exposed HDF cells and BALB/c mice. GM effectively halted UVB-induced cell senescence, and reduced MMP-1/-9, while elevated TIMP-1 levels, augmented COL1A1, ELN, and HAS-2 expression in vitro and in vivo. Additionally, it suppressed UVB-induced MAPKs, AP-1, NF-κB phosphorylation. Pharmacological inhibitors synergistically enhanced GM's anti-skin aging potential. Moreover, GM inhibited UVB-induced mTOR activation, upregulated LC3-II, Atg5, Beclin 1, and reduced p62 in both UVB induced HDF cells and BALB/c mice, while blocking of autophagy successfully halt the GM effects against the UVB-induced increase of cell senescence, degradation of collagen through upregulation of MMP-1, underscoring GM's substantial anti-skin aging impact via autophagy induction in vitro and in vivo. ConclusionTogether, GM has potent antioxidant and anti-skin aging ingredients that can be used to formulate skin care products for both the nutraceutical and cosmeceutical industries.

ANXA1sp modulates the protective effect of Sirt3-induced mitophagy against sepsis-induced myocardial injury in mice.

Sepsis-induced myocardial injury (SIMI) may be associated with insufficient mitophagy in cardiomyocytes, but the exact mechanism involved remains unknown. Sirtuin 3 (Sirt3) is mainly found in the mitochondrial matrix and is involved in repairing mitochondrial function through means such as the activation of autophagy. Previously, we demonstrated that the annexin-A1 small peptide (ANXA1sp) can promote Sirt3 expression in mitochondria. In this study, we hypothesized that the activation of Sirt3 by ANXA1sp induces mitophagy, thereby providing a protective effect against SIMI in mice. A mouse model of SIMI was established via cecal ligation and puncture. Intraperitoneal injections of ANXA1sp, 3TYP, and 3MA were administered prior to modeling. After successful modeling, IL-6, TNF-α, CK-MB, and CTn-I levels were measured; cardiac function was assessed using echocardiography; myocardial mitochondrial membrane potential, ROS, and ATP production were determined; myocardial mitochondrial ultrastructure was observed using transmission electron microscopy; and the expression levels of Sirt3 and autophagy-related proteins were detected using western blotting. ANXA1sp significantly reduced serum IL-6, TNF-α, CK-MB, and CTn-I levels; decreased myocardial ROS production; increased mitochondrial membrane potential and ATP synthesis; and improved myocardial mitochondrial ultrastructure in septic mice. Furthermore, ANXA1sp promoted Sirt3 expression and activated the AMPK-mTOR pathway to induce myocardial mitophagy. These protective effects of ANXA1sp were reversed upon treatment with the Sirt3 blocker, 3-TYP. ANXA1sp can reverse SIMI, and the underlying mechanism may be related to the activation of the AMPK-mTOR pathway following upregulation of Sirt3 by ANXA1sp, which, in turn, induces autophagy.

Impaired autophagy mechanisms associated with phospholamban-R14del disease

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Leducq Foundation Phospholamban (PLN) is a key modulator of sarcoplasmic reticulum Ca2+ homeostasis and cardiac contractility. The PLN variant c.40_42delAGA (p.R14del) leads to arrhythmogenic cardiomyopathy characterized by life-threatening ventricular arrhythmias and sudden cardiac death. A large number of PLN-R14del carriers have been identified worldwide, although the expanding use of genetic testing and increased awareness is unveiling a higher frequency. PLN-containing aggregates are emerging as a hallmark of this disease, and are increasingly believed to be associated with disease pathogenesis. However, the mechanism leading to the formation of aggregates is unknown. We performed an in depth molecular and cellular analysis utilizing in vitro systems to determine if these aggregates result from aberrations in autophagy, and the underlying mechanisms. Utilizing cell culture systems we studied the expression level and subcellular distribution of fundamental autophagy-related proteins and evaluated the impact of autophagy inducers and inhibitors. Expression of PLN-R14del in different cell culture systems (HEK293 and H9c2 cells) was found to result in PLN aggregate formation, which were determined to contain the autophagy marker proteins sequestosome-1 (p62) and microtubule-associated protein light chain 3 (LC3), indicating inefficient degradation by the autophagy pathway. In support of this, PLN-R14del expressing cells were shown to exhibit increased p62 and LC3-II protein levels. This was associated with significantly reduced autophagic flux, as demonstrated by examination of LC3-II protein levels after autophagy inhibition. Moreover, by detailed immunofluorescence analysis, we determined reduced co-localization of the autophagosomal protein LC3 and the lysosomal associated membrane protein 1 (LAMP1) in PLN-R14del cells, suggesting impaired autophagosome-lysosome fusion. We next examined the distribution of key proteins mediating autophagosome-lysosome membrane fusion including the Ras-related protein Rab7, the ultraviolet radiation resistance-associated gene (UVRAG) and membrane tether proteins. In PLN-R14del transfected cells, significant alterations in their co-localization with LC3 were observed, indicating their impaired recruitment to the autophagosomes. Importantly, in PLN-WT cells changes in cytosolic Ca2+ levels by thapsigargin treatment were found to recapitulate the autophagic defects of PLN-R14del, suggesting that Ca2+ alterations are a contributing factor of PLN-R14del mediated aberrant autophagy. In conclusion, our findings reveal a causal relationship between PLN-R14del and autophagy dysregulation, through inhibition of autophagosome-lysosome fusion and autophagic flux reduction. This ultimately leads to aggregate formation, an early pathological sign in human patients.

Chloramphenicol alleviates 5-fluorouracil-induced cellular senescence through activation of autophagy.

5-Fluorouracil (5-FU) is a first-line treatment for colorectal cancer, but side effects such as severe diarrhea are common in clinical use and have been linked to its induction of normal cell senescence. Chloramphenicol (CAP) is an antibiotic commonly used to treat typhoid or anaerobic infections, but its senescence-related aspects have not been thoroughly investigated. Here, we used 5-FU to induce senescence in human umbilical vein endothelial cells (HUVECs) and investigated the relationship between CAP and cellular senescence at the cellular level. In a model of cellular senescence induced by 5-FU treatment, we discovered that CAP treatment reversed the rise in the percentage of senescence-associated galactosidase (SA-β-gal)-positive cells and decreased the expression of senescence-associated proteins (p16), senescence-associated genes (p21), and senescence-associated secretory phenotypes (SASPs: IL-6, TNF-α). In addition, CAP subsequently restored the autophagic process inhibited by 5-FU and upregulated the levels of autophagy-related proteins. Mechanistically, we found that CAP restored autophagic flux by inhibiting the mTOR pathway, which in turn alleviated FU-induced cellular senescence. Our findings suggest that CAP may help prevent cellular senescence and restore autophagy, opening up new possibilities and approaches for the clinical management of colorectal cancer.

Curcumin affects autophagy of prolactinoma cells by upregulating miR-206 to exert antitumor effects.

We explored the effects of curcumin on the aberrant biological behaviors of prolactinoma cells and the downstream pathways through which curcumin exerts its antitumor effects. We used quantitative reverse transcription-polymerase chain reaction assays to measure miR-206 expression levels in peripheral blood samples from patients with prolactinoma before and after curcumin treatment. We also investigated the proliferation level, viability, and invasion ability of groups of cells treated with different concentrations of curcumin using 3-(4,5)-dimethylthiahiazo (-z-y1)-3-di-phenytetrazoliumromide (MTT) assays, cell cloning assays, and Transwell assays, respectively. Furthermore, we determined the levels of autophagy-related proteins and protein kinase B/mammalian target of the rapamycin (Akt/mTOR) signaling pathway-related proteins in each group of treated cells by western blot. Curcumin treatment upregulated miR-206 expression levels in the peripheral blood of patients with prolactinoma and in GH3 cells. Knockdown of miR-206 expression enhanced the proliferation and invasive ability of GH3 cells, while curcumin treatment effectively inhibited the aberrant biological behavior of GH3 cells enhanced by miR-206 knockdown. miR-206 knockdown also activated the Akt/mTOR signaling pathway and inhibited autophagy in GH3 cells, and these changes were effectively reversed by curcumin treatment. Thus, curcumin inhibited the Akt/mTOR signaling pathway and promoted cell autophagy by miR-206 upregulation, resulting in antitumor effects that inhibited prolactinoma cell proliferation and invasion.

The MnO2/GelMA Composite Hydrogels Improve the ROS Microenvironment of Annulus Fibrosus Cells by Promoting the Antioxidant and Autophagy through the SIRT1/NRF2 Pathway.

Intervertebral disc degeneration (IVDD) is a worldwide disease that causes low back pain and reduces quality of life. Biotherapeutic strategies based on tissue engineering alternatives, such as intervertebral disc scaffolds, supplemented by drug-targeted therapy have brought new hope for IVDD. In this study, to explore the role and mechanism of MnO2/GelMA composite hydrogels in alleviating IVDD, we prepared composite hydrogels with MnO2 and methacrylate gelatin (GelMA) and characterized them using compression testing and transmission electron microscopy (TEM). Annulus fibrosus cells (AFCs) were cultured in the composite hydrogels to verify biocompatibility by live/dead and cytoskeleton staining. Cell viability assays and a reactive oxygen species (ROS) probe were used to analyze the protective effect of the composite hydrogels under oxidative damage. To explore the mechanism of improving the microenvironment, we detected the expression levels of antioxidant and autophagy-related genes and proteins by qPCR and Western blotting. We found that the MnO2/GelMA composite hydrogels exhibited excellent biocompatibility and a porous structure, which promoted cell proliferation. The addition of MnO2 nanoparticles to GelMA cleared ROS in AFCs and induced the expression of antioxidant and cellular autophagy through the common SIRT1/NRF2 pathway. Therefore, the MnO2/GelMA composite hydrogels, which can improve the disc microenvironment through scavenging intracellular ROS and resisting oxidative damage, have great application prospects in the treatment of IVDD.

β-Elemene Reverses Gefitinib Resistance in NSCLC Cells by Inhibiting lncRNA H19-Mediated Autophagy.

Lung cancer is a leading cause of mortality worldwide, especially among Asian patients with non-small cell lung cancer (NSCLC) who have epidermal growth factor receptor (EGFR) mutations. Initially, first-generation EGFR tyrosine kinase inhibitors (TKIs) are commonly administered as the primary treatment option; however, encountering resistance to these medications poses a significant obstacle. Hence, it has become crucial to address initial resistance and ensure continued effectiveness. Recent research has focused on the role of long noncoding RNAs (lncRNAs) in tumor drug resistance, especially lncRNA H19. β-elemene, derived from Curcuma aromatic Salisb., has shown strong anti-tumor effects. However, the relationship between β-elemene, lncRNA H19, and gefitinib resistance in NSCLC is unclear. This study aims to investigate whether β-elemene can enhance the sensitivity of gefitinib-resistant NSCLC cells to gefitinib and to elucidate its mechanism of action. The impact of gefitinib and β-elemene on cell viability was evaluated using the cell counting kit-8 (CCK8) assay. Furthermore, western blotting and qRT-PCR analysis were employed to determine the expression levels of autophagy-related proteins and genes, respectively. The influence on cellular proliferation was gauged through a colony-formation assay, and apoptosis induction was quantified via flow cytometry. Additionally, the tumorigenic potential in vivo was assessed using a xenograft model in nude mice. The expression levels of LC3B, EGFR, and Rab7 proteins were examined through immunofluorescence. Our findings elucidate that the resistance to gefitinib is intricately linked with the dysregulation of autophagy and the overexpression of lncRNA H19. The synergistic administration of β-elemene and gefitinib markedly attenuated the proliferative capacity of resistant cells, expedited apoptotic processes, and inhibited the in vivo proliferation of lung cancer. Notably, β-elemene profoundly diminished the expression of lncRNA H19 and curtailed autophagic activity in resistant cells, thereby bolstering their responsiveness to gefitinib. Moreover, β-elemene disrupted the Rab7-facilitated degradation pathway of EGFR, facilitating its repositioning to the plasma membrane. β-elemene emerges as a promising auxiliary therapeutic for circumventing gefitinib resistance in NSCLC, potentially through the regulation of lncRNA H19-mediated autophagy. The participation of Rab7 in this dynamic unveils novel insights into the resistance mechanisms operative in lung cancer, paving the way for future therapeutic innovations.

Abstract PO2-28-03: E-Cigarette Aerosol Exposure: Unraveling the Nexus of Autophagy, Cancer Stem Cells, and EMT in Breast Cancer Metastasis

Abstract Electronic cigarettes (E-cigs) have emerged as a significant public health concern due to their increasing popularity. These products have been associated with various harmful effects on human health. In the United States, breast cancer is the most diagnosed cancer among women, and its recurrence and metastasis are primary contributors to morbidity and mortality. Two critical factors in cancer progression are Epithelial-mesenchymal transition (EMT) and Cancer stem-like cells (CSCs), both of which play pivotal roles in metastasis. As a result, targeting the signaling pathways involved in these processes has become a promising avenue for cancer therapy. Autophagy, a cellular process, has dual roles in cancer development depending on the cancer type and stage. Given these considerations, our hypothesis centers on disrupting the EMT-mediated metastatic cascade in breast cancer by targeting autophagy in Cancer Stem Cells (CSCs). To investigate this hypothesis, we conducted experiments using mouse breast epithelial cells (HC11) and Triple-negative mouse breast cancer cells (4T1) exposed to E-cig aerosol at the air-liquid interphase (ALI) for 1 hr followed by a 24 hr recovery period. Our findings indicate that exposure to E-cig aerosols led to a decrease in epithelial markers (E-Cadherin and β-catenin) and an increase in mesenchymal markers (N-Cadherin and Vimentin) in HC11 cells. This suggests that normal cells may acquire characteristics associated with solitary migration. Furthermore, we observed significant changes in the levels of autophagy-related proteins (LC3B, Beclin-1, ATG12, and ATG16) and upregulation of stem cell markers (OCT4, SOX2, NANOG, KLF4, and c-MYC) in response to E-cig aerosol exposure, both in HC11 and 4T1 cells. Additionally, these alterations extended to changes in the expression of genes associated with the Transforming Growth Factor-beta (TGF-β) signaling pathway, known to play a potential role in promoting EMT. Our results provide a deeper understanding of the interplay between EMT, CSCs, and the autophagy process in the context of ALI exposure in normal and cancer cells. This underscores the need for further research into the shared molecular mechanisms of these three processes to identify common therapeutic targets that can simultaneously affect them. Citation Format: Shilpa Thota, Rizwana Begum, Naveen Chintalaramulu, Biplov Sapkota, Abhishek Pandit. E-Cigarette Aerosol Exposure: Unraveling the Nexus of Autophagy, Cancer Stem Cells, and EMT in Breast Cancer Metastasis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-28-03.

Combining large-spot low-fluence 1064-nm and fractional 1064-nm picosecond lasers for promoting protective melanosome autophagy via the PI3K/Akt/mTOR signalling pathway for the treatment of melasma.

Melasma is a common condition of hyperpigmented facial skin. Picosecond lasers are reported to be effective for the treatment of melasma. We aimed to identify the most effective therapeutic mode and elucidate the potential molecular mechanisms of picosecond lasers for the treatment of melasma. Female Kunming mice with melasma-like conditions were treated using four different picosecond laser modes. Concurrently, invitro experiments were conducted to assess changes in melanin and autophagy in mouse melanoma B16-F10 cells treated with these laser modes. Changes in melanin in mouse skin were detected via Fontana-Masson staining, and melanin particles were evaluated in B16-F10 cells. Real-time polymerase chain reaction and western blotting were used to analyse the expression levels of melanosome and autophagy-related messenger ribonucleic acid (mRNA) and proteins. A combination of large-spot low-fluence 1064-nm and fractional 1064-nm picosecond lasers resulted insignificant decreases in melanin as well as in mRNA and protein expression of melanin-synthesizing enzymes (TYR, TRP-1 and MITF). This combination also led to increased expression of the autophagy-related proteins, Beclin1 and ATG5, with a marked decrease in p62 expression. Intervention with the PI3K activator, 740 Y-P, increased TYR, TRP-1, MITF, p-PI3K, p-AKT, p-mTOR and p62 expression but decreased the expression of LC3, ATG5 and Beclin1. A combination of large-spot low-fluence 1064-nm and fractional 1064-nm picosecond lasers proved more effective and safer. It inhibits melanin production, downregulates the PI3K/AKT/mTOR pathway, enhances melanocyte autophagy and accelerates melanin metabolism, thereby reducing melanin content.

Study on mechanism of inhibiting proliferation of head and neck cancer cells by citral, active ingredient of lemon essential oil

To explore the active substances exerting anti-tumour effect in lemon essential oil and the molecular mechanism inhibiting the proliferation of head and neck cancer cells SCC15 and CAL33, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay(MTT) was utilized to identify the active component inhibiting the proliferation of head and neck cancer cells, namely citral. The IC_(50) of citral inhibiting the proliferation of head and neck cancer cells and normal cells were also determined. In addition, a 5-ethynyl-2'-deoxyuridine(EdU) staining assay was used to detect the effect of citral on the proliferation rate of head and neck cancer cells, and a colony formation assay was used to detect the effect of citral on tumor sphere formation of head and neck cancer cells in vitro. The cell cycle arrest and apoptosis induction of head and neck cancer cells by citral were evaluated by flow cytometry, and Western blot was used to detect the effect of citral on the expression levels of cell cycle-and apoptosis-related proteins in head and neck cancer cells. The findings indicated that citral could effectively inhibit the proliferation and growth of head and neck cancer cells, with anti-tumor activity, and its half inhibitory concentrations for CAL33 and SCC15 were 54.78 and 25.23 μg·mL~(-1), respectively. Furthermore, citral arrested cell cycle at G_2/M phase by down-regulating cell cycle-related proteins such as S-phase kinase associated protein 2(SKP2), C-MYC, cyclin dependent kinase 1(CDK1), and cyclin B. Moreover, citral increased the cysteinyl aspartate-specific proteinase-3(caspase-3), cysteinyl aspartate-specific proteinase-9(caspase-9), and cleaved poly ADP-ribose polymerase(PARP). It up-regulated the level of autophagy-related proteins including microtubule associated protein 1 light chain 3B(LC3B), sequestosome 1(P62/SQSTM1), autophagy effector protein Beclin1(Beclin1), and lysosome-associate membrane protein 1(LAMP1), suggesting that citral could effectively trigger cell apoptosis and cell autophagy in head and neck cancer cells. Furthermore, the dual-tagged plasmid system mCherry-GFP-LC3 was used, and it was found that citral impeded the fusion of autophagosomes and lysosomes, leading to autophagic flux blockage. Collectively, our findings reveal that the main active anti-proliferation component of lemon essential oil is citral, and this component has a significant inhibitory effect on head and neck cancer cells. Its underlying molecular mechanism is that citral induces apoptosis and autophagy by cell cycle arrest and ultimately inhibits cell proliferation.

LINC00313 suppresses autophagy and promotes stemness of nasopharyngeal carcinoma cells through PTBP1/STIM1 axis

BackgroundNasopharyngeal carcinoma (NPC) is a kind of malignant head and neck tumor with high mortality. lncRNAs are valuable diagnostic biomarkers and therapeutic targets for various tumors. This study investigated the effects and mechanism of LINC00313 in nasopharyngeal carcinoma. MethodsCell Counting Kit-8 (CCK-8) and immunohistochemistry were used for assessing cell proliferation. The levels of autophagy-related proteins, and stem cell markers were detected. Immunofluorescence assay was used for LC3 detection. Methylated RNA Immunoprecipitation (meRIP) of LINC00313 in NPC cells was assessed. The localization of LINC00313 was verified by luorescence in situ hybridization (FIHS). The interaction between LINC00313 and the downstream targets were analyzed and confirmed by immunoprecipitation (RIP). Besides, the tumorigenesis roles of LINC00313 were confirmed in tumor growth mice model. ResultsLINC00313 was increased in NPC tissues and cells. LINC00313 knockdown enhanced autophagy, and decreased stemness and cell viability of NPC cells through regulating STIM1. METTL3/IGF2BP1-mediated m6A modification promoted the stabilization and up-regulation of LINC00313. LINC00313 activated AKT/mTOR pathway in NPC cells through PTBP1/STIM1 axis. Moreover, LINC00313 promoted tumor growth and metastasis in xenograft model. ConclusionUpregulation of LINC00313 suppressed autophagy and promoted stemness of NPC cells through PTBP1/STIM1 axis.

Investigating the Effects of Perampanel on Autophagy-mediated Regulation of GluA2 and PSD95 in Epilepsy.

Epilepsy is a chronic neurological disorder characterized by recurrent seizures. Despite various treatment approaches, a significant number of patients continue to experience uncontrolled seizures, leading to refractory epilepsy. The emergence of novel anti-epileptic drugs, such as perampanel (PER), has provided promising options for effective epilepsy treatment. However, the specific mechanisms underlying the therapeutic effects of PER remain unclear. This study aimed to investigate the intrinsic molecular regulatory mechanisms involved in the downregulation of GluA2, a key subunit of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, following epileptic seizures. Primary mouse hippocampal neurons were cultured and subjected to an epilepsy cell model. The expression levels of GluA2 and autophagy-related proteins were assessed using Western blotting and real-time fluorescent quantitative PCR. Immunofluorescence and immunohistochemistry techniques were employed to investigate the nuclear translocation of CREB-regulated transcriptional coactivator 1 (CRTC1). Additionally, status epilepticus animal models were established to further validate the findings. The epilepsy cell model exhibited a significant decrease in GluA2 expression, accompanied by elevated levels of autophagy-related proteins. Immunofluorescence analysis revealed the nuclear translocation of CRTC1, which correlated with the expression of autophagy-related genes. Treatment with an autophagy inhibitor reversed the decreased expression of GluA2 in the epilepsy cell model. Furthermore, the calcium/calmodulin-dependent protein phosphatase inhibitor FK506 and CaN overexpression affected the dephosphorylation and nuclear translocation of CRTC1, consequently influencing GluA2 expression. Animal model results further supported the involvement of these molecular mechanisms in epilepsy. Our findings suggest that the downregulation of GluA2 following epileptic seizures involves the activation of autophagy and the regulation of CRTC1 nuclear translocation. These intrinsic molecular regulatory mechanisms provide potential targets for developing novel therapeutic strategies to alleviate refractory epilepsy and preserve cognitive functions in patients.

Dysregulation of Autophagy Occurs During Congenital Cataract Development in βA3ΔG91 Mice.

To examine lens phenotypic characteristics in βA3ΔG91 mice and determine if βA3ΔG91 affects autophagy in the lens. We generated a βA3ΔG91 mouse model using CRISPR/Cas9 methodology. Comparative phenotypic and biochemical characterizations of lenses from postnatal day 0 (P0), P15, and 1-month-old βA3ΔG91 and wild-type (WT) mice were performed. The methodologies used included non-invasive slit-lamp examination, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot, and immunohistochemical (IHC) analyses to determine the levels of autophagy-related genes and proteins. Transmission electron microscopy (TEM) analysis of lenses was performed to assess organelle degradation and the presence of autophagic vesicles. TUNEL staining was used to determine apoptosis in the lens. Relative to WT lenses, 1-month-old βA3ΔG91 mice developed congenital nuclear cataract and microphthalmia and showed an early loss of endoplasmic reticulum (ER) in the cortex and attenuation of nuclei degradation. This observation was confirmed by TEM analysis, as was the presence of autophagic vesicles in βA3ΔG91 lenses. Comparative IHC and RT-qPCR analyses showed relatively higher levels of autophagy markers (ubiquitinated proteins and p62, LC3, and LAMP2 proteins) in βA3ΔG91 lenses compared to WT lenses. Additionally, βA3ΔG91 lenses showed relatively greater numbers of apoptotic cells and higher levels of cleaved caspase-3 and caspase-9. The deletion of G91 in βA3ΔG91 mice leads to higher levels of expression of autophagy-related proteins and their transcripts relative to WT lenses. Taken together, G91 deletion in βA3/A1-crystallin is associated with autophagy disruption, attenuation of nuclei degradation, and cellular apoptosis in the lens, which might be congenital cataract causative factors.

Differential effects of cholecalciferol and calcitriol on muscle proteolysis and oxidative stress in angiotensin II-induced C2C12 myotube atrophy.

Renin-angiotensin system activation contributes to skeletal muscle atrophy in aging individuals with chronic diseases. We aimed to explore the effects of cholecalciferol (VD3) and calcitriol (1,25VD3) on signaling of muscle proteolysis and oxidative stress in myotubes challenged with angiotensin II (AII). The mouse C2C12 myotubes were assigned to vehicle, AII, AII + VD3, AII + 1,25VD3, and AII + losartan groups. The expression levels of muscle-specific E3 ubiquitin ligase proteins, autophagy-related proteins, and oxidative stress markers were investigated. We demonstrated the diverse effects of VD3 and 1,25VD3 on AII-induced myotube atrophy. The myotube diameter was preserved by treatment with 100 nM VD3 and losartan, while 1 and 10 nM 1,25VD3 increased levels of FoxO3a, MuRF1, and atrogin-1 protein expression in myotubes exposed to AII. Treatment with AII + 10 nM 1,25VD3 resulted in the upregulation of LC3B-II, LC3B-II/LC3B-I, and mature cathepsin L, which are autophagic marker proteins. The p62/SQSTM1 protein was downregulated and vitamin D receptor was upregulated after treatment with AII + 10 nM 1,25VD3. A cellular redox imbalance was observed as AII + 10 nM 1,25VD3-induced reactive oxygen species and NADPH oxidase-2 overproduction, and these changes were associated with an inadequate response of antioxidant superoxide dismutase-1 and catalase proteins. Collectively, these findings provide a translational perspective on the role of vitamin D3 in alleviating muscle atrophy related to high levels of AII.

Abstract 5866: TESC mediates resistance to lenvatinib in hepatocellular carcinoma by regulating cell autophagy

Abstract Objective: To investigate the mechanism by which TESC (Tescalcin) induces lenvatinib resistance in hepatocellular carcinoma (HCC) through autophagy mediation. Methods:1) Utilized established liver cancer organoids from over 70 patients for lenvatinib drug sensitivity screening and transcriptome sequencing to identify lenvatinib-resistant genes. 2) Constructed stable TESC overexpression and downregulation liver cancer cell lines. Employed CCK8 assays to plot IC50 drug sensitivity curves, elucidating changes in lenvatinib sensitivity in liver cancer cells after TESC overexpression or downregulation. 3) Used TESC-stable cells to establish subcutaneous tumor models and intrahepatic tumor models in nude mice. After tumor formation, administered lenvatinib orally to observe whether TESC affects liver cancer sensitivity to lenvatinib in vivo. 4) Conducted Western blot (WB) analysis to assess the expression of autophagy-related molecules (LC3B II/I, P62, and Beclin1 proteins) in TESC downregulated or overexpressed stable cell lines and their control cell lines. Utilized the LC3-GFP-mRFP fluorescence dual-labeling lentivirus system and laser confocal microscopy to examine autophagic flux. 5)Treated TESC downregulated cells with the autophagy inhibitor 3-MA. Conducted WB to assess the expression levels of autophagy-related proteins and plotted drug sensitivity curves using IC50 experiments to evaluate the impact of 3-MA on reversing liver cancer cell sensitivity to lenvatinib. Results: Compared to the control group, HCC cells overexpressing TESC showed an increased IC50 value and reduced sensitivity to lenvatinib, while TESC downregulation resulted in a decreased IC50 value and decreased sensitivity to lenvatinib. Subcutaneous tumor experiments in nude mice indicated that, compared to the control group, tumors with reduced TESC expression were more sensitive to lenvatinib. Additionally, in HCC cells overexpressing TESC, protein expression levels of LC3B II/I and Beclin1 significantly decreased, while P62 expression increased. Conversely, TESC downregulation significantly increased protein expression levels of LC3B II/I and Beclin1, while P62 expression decreased. Furthermore, results from the LC3-GFP-mRFP autophagy dual-labeling lentivirus system showed a significant reduction in fluorescence spots in the TESC overexpression group compared to the control group, indicating weakened autophagic flux. Treatment of TESC downregulated liver cancer cells with 3-MA resulted in an increased IC50 value compared to the control group. Conclusion: TESC expression levels are associated with the sensitivity of liver cancer cells to lenvatinib, possibly by inhibiting autophagy and affecting the sensitivity of liver cancer cells to lenvatinib. Citation Format: Hao Zhuang, Tingting Zhang, Jiaqi Chen. TESC mediates resistance to lenvatinib in hepatocellular carcinoma by regulating cell autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5866.

GW9508 ameliorates cognitive dysfunction via autophagy pathway in streptozotocin-induced mouse model of Alzheimer's disease.

G protein-coupled receptor 40 (GPR40) is a potential drug target for Alzheimer's disease (AD), and its agonist GW9508 ameliorates cognitive impairment by intravenous administration. The present study was conducted to investigate the efficacy of GW9508 administered peripherally on cognitive dysfunction in streptozotocin (STZ)-induced AD mice. Seventy male ICR mice were randomly divided into seven groups: vehicle sham group, model, Donepezil, GW9508-L, GW9508-M, GW9508-H, and GW1100 + GW9508-H groups, and administered either vehicle (artificial cerebrospinal fluid [aCSF]) or STZ (3mg/kg in the vehicle) once a day (9:00 a.m.) by intracerebroventricular injection bilaterally on day 1 and day 3, respectively. After 2weeks of recovery, all mice were given drug treatment. Behavioral experiments were applied to test the recognition and spatial memory of mice, while molecular biology experiments such as Western blot, ELISA, and Nissl staining were used to detect the corresponding changes of signaling pathways. Intraperitoneal administration of GW9508 prevented STZ-induced cognitive impairment as well as decreased the level of p-tau and Aβ1-42 in plasma and brain. GW9508 upregulated the expression of gut-brain peptides like PYY, CCK, IGF-1, and GLP-1 both in blood circulation and brain and downregulated the expression level of autophagy-related proteins through activating Akt/mTOR signaling pathway. Meanwhile, the treatment effect of GW9508 was reversed by GPR40 antagonist GW1100 significantly. Peripheral administration of GW9508 exhibits neuroprotective effects, and it could be a promising therapy for AD. The neuroprotective mechanism of GW9508 was based on promoting gut-brain peptide secretion, activating Akt/mTOR signal pathway, and regulating neuronal autophagy.

Impaired autophagic flux in the human brain after traumatic brain injury.

Emerging evidence indicates that dysfunctional autophagic flux significantly contributes to the pathology of experimental traumatic brain injury (TBI). The current study aims to clarify its role post-TBI using brain tissues from TBI patients. Histological examinations, including hematoxylin and eosin, Nissl staining, and brain water content analysis, were employed to monitor brain damage progression. Electron microscopy was used to visualize autophagic vesicles. Western blotting and immunohistochemistry were performed to analyze the levels of important autophagic flux-related proteins such as Beclin1, autophagy-related protein 5, lipidated microtubule-associated protein light-chain 3 (LC3-II), autophagic substrate sequestosome 1 (SQSTM1/p62), and cathepsin D (CTSD), a lysosomal enzyme. Immunofluorescence assays evaluated LC3 colocalization with NeuN, P62, or CTSD, and correlation analysis linked autophagy-related protein levels with brain water content and Nissl bodies. Early-stage TBI results showed increased autophagic vesicles and LC3-positive neurons, suggesting autophagosome accumulation due to enhanced initiation and reduced clearance. As TBI progressed, LC3-II and P62 levels increased, while CTSD levels decreased. This indicates autophagosome overload from impaired degradation rather than increased initiation. The study reveals a potential association between worsening brain damage and impaired autophagic flux post-TBI, positioning improved autophagic flux as a viable therapeutic target for TBI.

The novel miR-873-5p-YWHAE-PI3K/AKT axis is involved in non-small cell lung cancer progression and chemoresistance by mediating autophagy.

Non-small cell lung cancer (NSCLC) encompasses approximately 85% of all lung cancer cases and is the foremost cancer type worldwide; it is prevalent in both sexes and known for its high fatality rate. Expanding scientific inquiry underscores the indispensability of microRNAs in NSCLC. Here, we probed the impact of miR-873-5p on NSCLC development and chemoresistance. qRT‒PCR was used to measure the miR-873-5p level in NSCLC cells with or without chemoresistance. A model of miR-873-5p overexpression was constructed. The proliferation and viability of NSCLC cells were evaluated through CCK8 and colony formation experiments. Cell migration and invasion were monitored via Transwell assays. Western blotting was used to determine the levels of YWHAE, PI3K, AKT, EMT, apoptosis, and autophagy-related proteins. The sensitivity of NSCLC cells to the chemotherapeutic agent gefitinib was assessed. Additionally, the correlation of YWHAE with miR-873-5p was validated via a dual-luciferase reporter assay and RNA immunoprecipitation (RIP). Overexpressed miR-873-5p suppressed migration, proliferation, invasion, and EMT while concurrently stimulating apoptotic processes. miR-873-5p was downregulated in NSCLC cells resistant to gefitinib. Upregulating miR-873-5p reversed gefitinib resistance by inducing autophagy. YWHAE was confirmed to be a downstream target of miR-873-5p. YWHAE overexpression promoted the malignant behaviors of NSCLC cells and boosted tumor growth, while these effects were reversed following miR-873-5p overexpression. Subsequent investigations revealed that overexpressing YWHAE promoted PI3K/AKT pathway activation, with miR-873-5p displaying inhibitory effects on the YWHAE-mediated PI3K/AKT signaling cascade. miR-873-5p affects proliferation, invasion, migration, EMT, autophagy, and chemoresistance in NSCLC by controlling the YWHAE/PI3K/AKT axis.