Protein Expression Levels Of LC3-II Research Articles

Exogenous Beta-guanidinopropionic acid administration enhances electromyostimulation-induced mitochondrial biogenesis in rat skeletal muscle

Abstract Objectives Exercise training induces several skeletal muscle adaptations. Beta-guanidinopropionic acid (β-GPA) is a creatine analog that simulates the effect of exercise to induce mitochondrial biogenesis. However, the effects of β-GPA on resistance training adaptation, such as muscle hypertrophy and mitochondrial biogenesis, are unclear. Therefore, using a resistance exercise model in rats, the present study was designed to investigate the effects of β-GPA administration on resistance training adaptations. Methods This study was approved by the Ethics Committee for Animal Experiments at Ritsumeikan University (approval number: BKC2022-009). Male Sprague Dawley rats were randomly divided into placebo or β-GPA groups. β-GPA (1000 mg/kg) was orally administered once daily, starting seven days before the initiation of electromyostimulation as a model for resistance exercise, and continued throughout the training period. Electromyostimulation was applied to the right gastrocnemius muscle via electrical stimulation every other day for a total of 12 sessions Results Peroxisome proliferators-activated receptor-γ co-activator-1α, a regulator of mitochondrial biogenesis, was significantly increased by the combination of training and β-GPA compared to the training leg (p<0.05). Protein expression of Total OXPHOS, a marker of mitochondrial content, was significantly increased by the combination of training and β-GPA compared to the training leg (p<0.05). β-GPA intake reduced muscle mass (main effect of β-GPA, p<0.05) and was associated with muscle protein breakdown-related Fbx32 and LC3-II protein expression levels but did not counteract the increase in muscle mass caused by resistance training. Conclusions Administration of exogenous β-GPA enhanced resistance training-induced mitochondrial biogenesis. Moreover, β-GPA still permitted resistance electromyostimulation-induced muscle mass gains, but that effect was attenuated as compared to placebo.

Trehalose Alleviates D-Galactose-Induced Aging-Related Granulosa Cell Death in Ovaries.

Ovarian dysfunction caused by aging restricts female reproductive capacity and is accompanied by oxidative stress and impaired autophagy. Recent studies have shown that trehalose (Tre) can activate autophagy and have antioxidant effects. However, whether Tre can be used to attenuate ovarian aging remains unclear. Therefore, the anti-aging effects of Tre on the ovary were explored both in vivo and in vitro. D-galactose (D-gal) was administered i.p. daily (200 mg/kg body weight) for 8 weeks to establish the mouse ovarian aging model (n = 10). We found that Tre significantly reversed ovarian weight loss and reduced the number of TUNEL-positive granulosa cells caused by D-gal in mouse ovaries. Tre elevated the protein expression levels of LC3-II, Parkin, PINK1, Beclin1, and LAMP2 in ovaries. Mitochondrial-related proteins TOM20 and COX IV expression levels were increased by Tre administration. In vitro studies further supported these findings, showing that Tre treatment significantly reduced the number of SA-β-gal and PI-positive cells, and decreased ROS levels in cultured granulosa cells. Thus, Tre alleviates ovarian aging by activating mitophagy and reducing oxidative stress, suggesting its potential as an anti-aging agent for ovarian health.

LncRNA NEAT1 promotes MPP+ induced injury of PC12 cells and accelerates the progression of Parkinson's disease in mice through FUS mediated inhibition of PI3K/AKT/mTOR signalling pathway

Long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) is involved in the progression of Parkinson's disease (PD), but the specific regulatory role needs further exploration. This study showed that the expression of NEAT1 was upregulated in the cerebrospinal fluid (CSF) and peripheral blood of patients with different stages of PD. 1-Methyl-4-phenylpyridine (MPP)-treated PC 12 cells were transfected with si-NEAT1, and MPP treatment promoted cell apoptosis, oxidative stress and inflammatory factor secretion. Si-NEAT1 reversed the effects of MPP. NEAT1 silencing eliminated the effect of MPP on the protein expression levels of LC3-II and p62/SQSTM1. By using an online bioinformatics database, Fused in Sarcoma (FUS) was confirmed to be an RNA binding protein of NEAT1, and it was highly expressed in the CSF and peripheral blood of patients with PD. Si-FUS was transfected into MPP-treated PC 12 cells to detect cell apoptosis, oxidative stress, inflammatory factor secretion and autophagy, and the results were the same as those of transfection of si-NEAT1. Furthermore, MPP treatment reduced the phosphorylation levels of PI3K, Akt and mTOR, whereas si-FUS reversed the effects of MPP. In vivo, compared with the model group, the PD mice showed reduced NEAT1 and FUS expression levels and activated PI3K pathway after being injected with si-NEAT1. The brain tissue of NEAT1-silenced PD mice had decreased inflammatory infiltration and apoptosis and increased neurological scores. In conclusion, NEAT1 is involved in PD progression through FUS-mediated inhibition of the PI3K/AKT/mTOR signalling pathway.

VPS13D affects epileptic seizures by regulating mitochondrial fission and autophagy in epileptic rats

Abnormal mitochondrial dynamics can lead to seizures, and improved mitochondrial dynamics can alleviate seizures. Vacuolar protein sorting 13D (VPS13D) is closely associated with regulating mitochondrial homeostasis and autophagy. However, further investigation is required to determine whether VPS13D affects seizures by influencing mitochondrial dynamics and autophagy. We aimed to investigate the influence of VPS13D on behavior in a rat model of acute epileptic seizures. Hence, we established an acute epileptic seizure rat model and employed the CRISPR/CAS9 technology to construct a lentivirus to silence the Vps13d gene. Furthermore, we used the HT22 mouse hippocampal neuron cell line to establish a stable strain with suppressed expression of Vps13d in vitro. Then, we performed quantitative proteomic and bioinformatics analyses to confirm the mechanism by which VPS13D influences mitochondrial dynamics and autophagy, both in vitro and in vivo using the experimental acute epileptic seizure model. We found that knockdown of Vps13d resulted in reduced seizure latency and increased seizure frequency in the experimental rats. Immunofluorescence staining and western blot analysis revealed a significant increase in mitochondrial dynamin-related protein 1 expression following Vps13d knockdown. Moreover, we observed a significant reduction in LC3II protein expression levels and the LC3II/LC3I ratio (indicators for autophagy) accompanied by a significant increase in P62 expression (an autophagy adaptor protein). The proteomic analysis confirmed the up-regulation of P62 protein expression. Therefore, we propose that VPS13D plays a role in modulating seizures by influencing mitochondrial dynamics and autophagy.

Effects of Astragalus polysaccharide on the structure and function of skeletal muscle in D-galactose-induced C57BL/6J mice.

To investigate the effects of Astragalus polysaccharide (APS) on skeletal muscle structure and function in D-galactose (D-gal)-induced C57BL/6J mice. Eighteen male C57BL/6J mice of specific pathogen-free (SPF) grade, aged 8 weeks, were selected and divided into three groups: a control group (0.9% saline gavage for 16 weeks), a D-gal group (subcutaneous injection of 200 mg/kg D-galactose in the upper neck region, once daily for 8 weeks), and a D-gal + APS group (subcutaneous injection of 200 mg/kg D-galactose, once daily for 8 weeks, with concurrent administration of 100 mg/kg APS by gavage for 8 weeks). Body composition of the mice was assessed using the ImpediVET Laboratory Composition Measurement Analyzer. The pathological structure of the skeletal muscles was examined using hematoxylin and eosin (HE) staining, and the microstructure and mitochondrial alterations in skeletal muscle were observed under transmission electron microscopy. Protein expression levels of LC3II and PINK1 in skeletal muscle tissues were analyzed using Western blotting analysis. Compared to the control group, the D-gal-treated mice demonstrated substantial declines in grip strength, the cross-sectional area (CSA) of gastrocnemius muscle fibers, gastrocnemius weight, and the gastrocnemius weight-to-body weight ratio. APS administration markedly improved these parameters in the D-gal-treated mice. H&E staining showed muscle atrophy and senescence in the D-gal-treated mice, accompanied by deformed muscle cell morphology, which was mitigated by APS gavage. The D-gal-treated mice displayed swelling, cristae fracture, lysis, or complete loss, alongside reduced autophagy and increased lengths of bright bands, myofibrillar myonules, and H bands. However, administration of APS alleviated mitochondrial damage, promoted mitophagy, and reduced the lengths of these muscle tissue bands. Additionally, D-gal treatment significantly reduced LC3II and PINK1 protein expression in muscle tissues, while APS treatment notably elevated their expression levels. APS gavage ameliorates the structural and functional impairments in muscle tissues of the D-gal-treated mice by promoting mitochondrial autophagy.

Melatonin alleviates renal injury in diabetic rats by regulating autophagy.

Melatonin (MLT) is a biologically active indoleamine involved in regulating various biological rhythms, which is deficient in individuals with Type 2 diabetes. The present study examined the effects of MLT on diabetic neuropathy (DN). Diabetic rats received MLT treatment for 12weeks, after which changes in kidney histology, oxidative damage, mitochondrial morphology and autophagy were measured. The glucose tolerance‑ and isoflurane tolerance‑area under the curve (AUC) values and the relative renal weight index (RI) in the diabetes mellitus (DM) group of rats were significantly higher compared with those in the control group. A significant increase in malondialdehyde (MDA) content, and decreases in the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH‑Px) and GSH were demonstrated in the kidneys of DM rats compared with those in the control rats. Histological staining of DM rat kidney tissue with hematoxylin and eosin, Masson's trichome and Periodic acid‑Schiff demonstrated glomerular and tubule lesions, and an increase in collagen compared with control rats. Protein expression levels of LC3II, P62, collagen IV (COL‑IV) and α‑SMA were increased in DM rats and HG‑induced NRK‑52E cells compared with those in the control groups. Phosphorylation of AMPK was reduced, whereas phosphorylation of PI3K, Akt and mTOR were increased invivo and invitro. Notably, MLT treatment significantly reduced glucose tolerance‑AUC and RI, decreased MDA content, and increased SOD, CAT, GSH‑Px and GSH activity. Glomerular and tubule lesions improved, collagen was decreased and mitochondrial damage was alleviated by MLT treatment. MLT treatment also decreased the protein expression levels of LC3II, P62 and COL‑IV, whereas the phosphorylation of AMPK was significantly increased, which inhibited the phosphorylation of PI3K, AKT and mTOR invivo and invitro. These results demonstrated that MLT protects against DN and NRK‑52E cell injury through inhibiting oxidative damage and regulating autophagy via the PI3K/AKT/mTOR signaling pathway.

Effects of true-to-life PET nanoplastics using primary human nasal epithelial cells

Since inhalation is a relevant exposure route, studies using appropriate micro/nanoplastic (MNPLs) models, representative targeted cells, and relevant biomarkers of effect are required. We have used lab-made polyethylene terephthalate (PET)NPLs obtained from PET plastic water bottles. Human primary nasal epithelial cells (HNEpCs) were used as a model of the first barrier of the respiratory system. Cell internalization and intracellular reactive oxygen species (iROS) induction, as well as the effects on mitochondria functionality and in the modulation of the autophagy pathway, were evaluated. The data indicated significant cellular uptake and increased levels of iROS. Furthermore, a loss of mitochondrial membrane potential was observed in the exposed cells. Regarding the effects on the autophagy pathway, PETNPLs exposure significantly increases LC3-II protein expression levels. PETNPLs exposure also induced significant increases in the expression of p62. This is the first study showing that true-to-life PETNPLs can alter the autophagy pathway in HNEpCs.

Emodin Ameliorates High Glucose-Induced Podocyte Apoptosis via Regulating AMPK/mTOR-Mediated Autophagy Signaling Pathway.

To investigate the effect of emodin on high glucose (HG)-induced podocyte apoptosis and whether the potential anti-apoptotic mechanism of emodin is related to induction of adenosine-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)-mediated autophagy in podocytes (MPC5 cells) in vitro. MPC5 cells were treated with different concentrations of HG (2.5, 5, 10, 20, 40, 80 and 160 mmol/L), emodin (2, 4, 8 µ mol/L), or HG (40 mmol/L) and emodin (4 µ mol/L) with or without rapamycin (Rap, 100 nmol/L) and compound C (10 µ mol/L). The viability and apoptosis of MPC5 cells were detected using cell counting kit-8 (CCK-8) assay and flow cytometry analysis, respectively. The expression levels of cleaved caspase-3, autophagy marker light chain 3 (LC3) I/II, and AMPK/mTOR signaling pathway-related proteins were determined by Western blot. The changes of morphology and RFP-LC3 fluorescence were observed under microscopy. HG at 20, 40, 80 and 160 mmol/L dose-dependently induced cell apoptosis in MPC5 cells, whereas emodin (4 µ mol/L) significantly ameliorated HG-induced cell apoptosis and caspase-3 cleavage (P<0.01). Emodin (4 µ mol/L) significantly increased LC3-II protein expression levels and induced RFP-LC3-containing punctate structures in MPC5 cells (P<0.01). Furthermore, the protective effects of emodin were mimicked by rapamycin (100 nmol/L). Moreover, emodin increased the phosphorylation of AMPK and suppressed the phosphorylation of mTOR. The AMPK inhibitor compound C (10 µ mol/L) reversed emodin-induced autophagy activation. Emodin ameliorated HG-induced apoptosis of MPC5 cells in vitro that involved induction of autophagy through the AMPK/mTOR signaling pathway, which might provide a potential therapeutic option for diabetic nephropathy.

Modulatory role of BV6 and chloroquine on the regulation of apoptosis and autophagy in non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) is one of the aggressive tumors mostly diagnosed in the advanced stage. Therapeutic failure and drug resistance pose a major problem in NSCLC treatment primarily due to alterations in autophagy and loss of apoptosis. Therefore, the present study aimed to investigate the importance of the second mitochondria-derived activator of caspase mimetic BV6 and autophagy inhibitor chloroquine (CQ) on the regulation of apoptosis and autophagy, respectively. Study was conducted on NCI-H23 and NCI-H522 cell lines to evaluate the effect of BV6 and CQ on the transcription and translation level of LC3-II, caspase-3, and caspase-9 genes by quantitative real-time-polymerase chain reaction and western blotting techniques. In NCI-H23 cell line, BV6 and CQ treatments showed increased mRNA and protein expression of caspase-3, and caspase-9 compared to its untreated counterpart. BV6 and CQ treatments also caused downregulation of LC3-II protein expression compared to its counterpart. In NCI-H522 cell line, BV6 treatment showed a significantly increased expression of caspase-3 and caspase-9 mRNA and protein expression levels whereas BV6 treatment downregulated the expression level of LC3-II protein. A similar pattern was also observed in CQ treatment when compared with the respective controls. Both BV6 and CQ modulated in vitro expression of caspases and LC3-II which have critical regulatory roles in apoptosis and autophagy, respectively. Our findings suggest that BV6 and CQ could be promising candidates in NSCLC treatment and there is a need to explore them in vivo and in clinical applications.

Effect of Combined Sorafenib/Cisplatinum Treatment on the Autophagy and Proliferation of Hepatocellular Carcinoma hepG2 Cells in Vitro.

Objective:To explore the effect of combined Sorafenib/ cisplatinum treatment on the autophagy and proliferation of hepatocellular carcinoma (HepG2) cells in vitro. Methods:HepG2 cells were cultured and treated with different concentrations of Sorafenib, cisplatinum, or a combination of both over a 24-hour period. Cell proliferation was evaluated using a CCK8 assay, and the mRNA expression of the autophagy-related proteins AKT, mTOR, and LC3 were detected using quantitative PCR (qPCR). AKT, pAKT (Ser473), mTOR, pmTOR (Ser2448), LC3I, and LC3II protein expression levels were evaluated by western blot. Results:We found that the survival rate of HepG2 cells was 47.42% when treated with Sorafenib (10 μmol/L) monotherapy, and 46.04% when treated with cisplatinum (10 mg/L) monotherapy. When Sorafenib(10 μmol/L) was combined with cisplatinum (10 mg/L), the cellular proliferation and survival rate was only 16.71% ( P <0.05). qPCR and western blot revealed that a combination of Sorafenib (10 μmol/L) and cisplatinum (10 mg/L) reduced the transcription and protein expression of autophagy-related AKT and mTOR but increased that of LC3 (P <0.05). Conclusion: Combining Sorafenib and cisplatinum can effectively induce cell autophagy and reduce cellular proliferation via the PI3K/AKT/mTOR signal pathway.

Low-intensity pulsed ultrasound activates autophagy in periodontal ligament cells in the presence or absence of lipopolysaccharide

ObjectiveThis study aims to determine if low-intensity pulsed ultrasound (LIPUS) activates autophagy in human periodontal ligament cells (PDLCs) irrespective of lipopolysaccharide. DesignSix groups were designed: control, LIPUS, lipopolysaccharide, LIPUS + lipopolysaccharide, LIPUS+3-Methyladenine, LIPUS + lipopolysaccharide+3-Methyl- adenine. LIPUS pretreated PDLCs for 2 h and lipopolysaccharide treated for different times. Real-time PCR and Western-blot were performed to evaluate mRNA and protein expression levels of autophagic genes Beclin-1 and LC3 respectively. A transmission electronic microscope was used to observe the autophagosome. ELISA was used to test interleukin-6 expression. ResultsCompared with the non-treatment, LIPUS pretreatment increased mRNA expression levels of LC3 (P < 0.05) and Beclin-1 (P < 0.05) at 4 h and 8 h, and enhanced the protein expression levels of LC3-Ⅱ at 8 h (P<0.05) and Beclin-1 at 4 h, 8 h and 16 h(P<0.05). After LIPUS pretreatment and lipopolysaccharide treatment for 8 h, LC3-Ⅱ and Beclin-1 protein expression levels were elevated (P < 0.05) compared with the control. Following further treatment by 3-Methyladenine, Beclin-1 protein expression was decreased (P < 0.05) compared with the LIPUS plus lipopolysaccharide group, but LC3-Ⅱ protein expression was not. Autophagosomes were not found in the LIPUS+3-Methyladenine and LIPUS+lipopolysaccharide+3-Methyladenine groups. After LIPUS pretreatment and lipopolysaccharide treatment for 36 h, intreleukin-6 expression was decreased (P<0.05) compared with the lipopolysaccharide group. However, after addition of 3-Methyladenine, intreleukin-6 expression was elevated (P < 0.05) compared with the LIPUS +lipopolysaccharide group. ConclusionsLIPUS can promote autophagy in PDLCs irrespective of lipopolysaccharide. Autophagy might be involved in LIPUS anti-inflammatory mechanism in PDLCS.

Lentiviral-Mediated Beclin-1 Overexpression Inhibits Cell Proliferation and Induces Autophagy of Human Esophageal Carcinoma Eca109 Cell Xenograft in Nude Mice.

Esophageal carcinoma is one of the common malignant tumors in digestive tract. BECLIN-1 is a key gene that regulates autophagy, and its abnormal expression may be related with many human tumors. However, the mechanism of BECLIN-1 in esophageal carcinoma remains unknown. In this study, we explored the effect of BECLIN-1 overexpression on tumor growth in mice with esophageal carcinoma and its mechanism. Recombined lentiviral vector containing BECLIN-1 was used to transfect human esophageal carcinoma Eca109 cells and establish stable cell line. qRT-PCR was used to detect BECLIN-1 mRNA level in the transfected Eca109 cells, CCK-8 assay was used to detect cell proliferation. Beclin-1, P62 and LC3-II protein expression levels in Eca109 cells were detected using Western blot analysis. Subcutaneous xenograft nude mice model of human esophageal carcinoma was established, and the tumor growths in Beclin-1 group, control group and empty vector group were monitored. Beclin-1 protein expression in vivo was detected by immunohistochemistry. Beclin-1 mRNA and protein were overexpressed in Eca109 cells. Compared with empty vector group, the growth rate of cells transfected with BECLIN-1 decreased significantly. Compared with the control group and empty vector group, the expression level of P62 protein in beclin-1 group was significantly decreased, while the expression level of LC3-II protein was significantly increased. The tumor growth rate in nude mice of Beclin-1 group was significantly lower than that of the control group and empty vector group, and Beclin-1 protein was mainly expressed in Beclin-1 group in vivo. BECLIN-1 can induce autophagy in esophageal carcinoma Eca109 cells, and it can significantly inhibit the growth of esophageal carcinoma.

Si-Wei-Qing-Gan-Tang Improves Non-Alcoholic Steatohepatitis by Modulating the Nuclear Factor-κB Signal Pathway and Autophagy in Methionine and Choline Deficient Diet-Fed Rats.

Si-Wei-Qing-Gan-Tang (SWQGT) is a Chinese medicine formula that is widely used as a folk remedy of herbal tea for the treatment of chronic hepatitis, like non-alcoholic steatohepatitis (NASH), around Ganzhou City (Jiangxi province, China). However, the underlying mechanisms of this formula against NASH are still unknown. This study aimed to explore the effect and mechanisms of SWQGT against NASH. A network pharmacology approach was used to predict the potential mechanisms of SWQGT against NASH. Then a rat model of NASH established by feeding the methionine and choline deficient (MCD) diet was used to verify the effect and mechanisms of SWQGT on NASH in vivo. SWQGT (1 g/kg/d and 3 g/kg/d) were given by intragastric administration. Body weight, liver weight, serum biochemical indicators, liver triglyceride and total cholesterol were all measured. Tumor necrosis factor-α (TNF-α), Interleukin (IL)-1β, IL-6 levels in the livers were evaluated using ELISA. Hematoxylin and eosin (HE) and Oil Red O staining were used to determine histology, while western blot was used to assess the relative expression levels of the nuclear factor-κB (NF-κB) pathway- and autophagy-related proteins. Functional and pathway enrichment analyses revealed that SWQGT obviously influenced inflammation-related signal pathways in NASH. Furthermore, in vivo experiment showed that SWQGT caused a reduction in liver weight and liver index of MCD diet-fed rats. The formula also helped to reduce hepatomegaly and improve pathological liver changes and hepatic steatosis. SWQGT likewise reduced liver TNF-α, IL-1β, and IL-6 levels and down-regulated p-NF-κB p65, p-p38 MAPK, p-MEK1/2, p-ERK1/2, p-mTOR, and p62, while up-regulating p-ULK1 and LC3II protein expression levels. SWQGT could improve NASH in MCD diet-fed rats, and this effect may be associated with its down-regulation of NF-κB and activation of autophagy.

Multifunctional N-P-doped carbon dots for regulation of apoptosis and autophagy in B16F10 melanoma cancer cells and in vitro imaging applications

Rationale: The present study reports the multifunctional anticancer activity against B16F10 melanoma cancer cells and the bioimaging ability of fluorescent nitrogen-phosphorous-doped carbon dots (NPCDs).Methods: The NPCDs were synthesized using a single-step, thermal treatment and were characterized by TEM, XPS, fluorescence and UV-Vis spectroscopy, and FTIR analysis. The anticancer efficacy of NPCDs was confirmed by using cell viability assay, morphological evaluation, fluorescent live-dead cell assay, mitochondrial potential assay, ROS production, RT-PCR, western-blot analysis, siRNA transfection, and cellular bioimaging ability.Results: The NPCDs inhibited the proliferation of B16F10 melanoma cancer cells after 24 h of treatment and induced apoptosis, as confirmed by the presence of fragmented nuclei, reduced mitochondrial membrane potential, and elevated levels of reactive oxygen species. The NPCDs treatment further elevated the levels of pro-apoptotic factors and down-regulated the level of Bcl2 (B-cell lymphoma 2) that weakened the mitochondrial membrane, and activated proteases such as caspases. Treatment with NPCDs also resulted in dose-dependent cell cycle arrest, as indicated by reduced cyclin-dependent kinase (CDK)-2, -4, and -6 protein levels and an enhanced level of p21. More importantly, the NPCDs induced the activation of autophagy by upregulating the protein expression levels of LC3-II and ATG-5 (autophagy-related-5) and by downregulating p62 level, validated by knockdown of ATG-5. Additionally, owing to their excellent luminescence property, these NPCDs were also applicable in cellular bioimaging, as evidenced by the microscopic fluorescence imaging of B16F10 melanoma cells.Conclusion: Based on these findings, we conclude that our newly synthesized NPCDs induced cell cycle arrest, autophagy, and apoptosis in B16F10 melanoma cells and presented good cellular bioimaging capability.

Electroacupuncture and moxibustion pretreatments reduce cardiomyocyte apoptosis and autophagy in rats with myocardial ischemia/reperfusion injury

To observe the effect of "Neiguan" (PC6)-electroacupuncture (EA) or moxibustion (Moxi) pretreatment on myocardial apoptosis and expression of autophagy related proteins light chain (LC) 3-Ⅰ and LC3-Ⅱ in rats with myocardial ischemia/reperfusion injury (MIRI), so as to explore their mechanisms underlying improvement of MIRI. Forty SD rats (half male and half female) were randomly divided into sham operation, model, ischemic preconditioning (IP), EA and Moxi groups (n＝8 in each group). EA (10 Hz/50 Hz, 1 mA) or Moxi (ignited moxa stick) was respectively applied to bilateral "Neiguan" (PC6) for 20 min, once daily for 7 days. The MIRI model was established by occlusion of the anterior descending branch of the left coronary artery for 40 min, followed by reperfusion for 60 min. The ultrastructural changes and autophagy of myocardial cells were observed by electron microscopy (EM), and the myocardial cellular apoptosis [apoptotic index ＝ (number of apoptotic cells/total number of cardiomyocytes)×100%] was detected by the terminal deoxyribonucleotidyl transferase mediated dUTP nick end labelling (TUNEL) method. The expressions of LC3-Ⅰ and LC3-Ⅱ proteins (markers for autophagy) in myocardial tissue were detected by Western blot. Following MI, EM observation revealed a vague structure of cardiomyocytes and muscular horizontal grain, dissolution of myofibers, mitochondrial swelling, some autophagic vacuoles and autophagic lysosomes at different degrees and surrounded by a double membrane in the model group, these situations were apparently milder in the EA and Moxi groups. The apoptosis index, myocardial LC3-Ⅰ and LC3-Ⅱ protein expression levels, and the ratio of LC3-Ⅱ/Ⅰ were significantly increased in the model group relevant to the sham operation group (P<0.05). After the treatment, the apoptosis index, the expression level of myocardial LC3-Ⅱ protein and the ratio of LC3-Ⅱ/Ⅰ were considerably down-regulated in the IP, EA and Moxi groups in comparison with those in the model group (P<0.05). The effect of EA was obviously superior to those of IP and Moxi in down-regulating the apoptosis index (P<0.05), but obviously inferior to those of IP and Moxi in down-regulating the levels of LC3-Ⅱ and LC3-Ⅱ/Ⅰ (P<0.05). No significant changes were found in the expression of LC3-Ⅰ after IP, EA and Moxi interventions in comparison with the model group (P>0.05), and no significant differences were observed in the apoptosis index and levels of LC3-Ⅱ and LC3-Ⅱ/Ⅰ between the IP and Moxi groups (P>0.05)．. Both EA and moxibustion pretreatments, similar to IP, have a positive role in reducing myocardiocyte apoptosis and regulating autophagy-related protein expression in MIRI rats, which maybe contribute to their protective effects on ischemic myocardium.

Pyrethrum-extract induced autophagy in insect cells: A new target?

Pyrethrum extract (PY) is a natural insecticide that is extensively used across the world, and its insecticidal activity is attributed to the presence of six active esters known as pyrethrins. PY targets the nervous systems of insects by delaying the closure of voltage-gated sodium ion channels in the nerve cells. However, limited information is available regarding the toxicity and detailed mechanisms of PY activity. This study is aimed at understanding the toxicity effect and the underlying mechanisms of PY in cellular level, which have not yet been investigated on the non-nervous system of insects. Results of the MTT assay showed that the viability of Sf9 cells was inhibited by PY in a time- and concentration-dependent manner, and observation under a microscope revealed accumulation of intracellular vacuoles. Monodansylcadaverine staining analysis and transmission electron microscope images revealed typical autophagic morphological changes in PY-treated Sf9 cells. Autophagy-related proteins such as LC3, p62, and beclin-1 were detected using by Western blotting. Protein expression levels of LC3-II and beclin-1 were upregulated while that of p62 was markedly downregulated in a dose-dependent manner upon the PY treatment in Sf9 cells. In conclusion, these results indicate that PY could induce autophagy in the non-nervous system of insects which may contribute to its insecticidal mechanism.

MP36-12 CLONALITY OF BLADDER TUMORS FOLLOWING RADICAL NEPHROURETERECTOMY – AGAINST THE FIELD DEFECT HYPOTHESIS

INTRODUCTION AND OBJECTIVES: Macroautophagy, also known as type II programmed cell death, is a regulated catabolic pathway to degrade cellular organelles and macromolecules. The role of autophagy in cancer is complex and may differ depending on tumor type or context. Here, we investigated the activated basal autophagy in bladder cancer cells and its roles in maintaining cancer cell growth. METHODS: Human immortalized uroepithelium (SV-Huc-1) and bladder cancer cells including RT-4 (grade I), 5637 (grade II), HT1376 and T24 (grade III) were used. We also included human prostate cancer cells (Rv1 and PC3), breast cancer cell (MCF-7) and embryonic kidney cancer cell (293T) as reference cells. The cell viability was accessed by WST-8. Autophagy was detected by the expression level of LC3-II protein. Human bladder tumor tissue array (TMA; 12 cases, paired with normal tissue) was used to detect the LC3 expression level. Detection of apoptosis level was measured by caspase 3/7 activation, caspase 3 cleavage and TUNEL assays. The ROS generation, mitochondria membrane potential in cells treated with autophagy inhibitors was assayed by staining with H2DCFCA and JC-1 dyes, respectively, and subsequently subjected to flow cytometry analysis. Disruption of lysomome membrane (LMP) by was detected by immunofluorescent of cathepsin-D in cells treated with CQ. RESULTS: We found bladder cancer cells exhibited high basal level of autophagy compared to prostate, breast or embryonic kidney cancer cells. Immunohistochemistry (IHC) detection of LC3 in human bladder TMA showed increased level of LC3 in bladder tumor tissues compared to their paired normal tissues. In the cell-based experiment, we found that autophagy inhibitors alone inhibited bladder cancer cell growth and increased apoptosis. The ROS generation and MMP disruption were not detected in cells treated with CQ or HCQ. Immunofluorescent detection of cathepsin-D in cells treated with CQ showed dispread pattern in the cytosol, suggesting the disruption of LMP in CQ-treated bladder cancer cells. CONCLUSIONS: Our results showed that human bladder cancer exhibits high basal level of autophagy. Autophagy inhibitors showed significant effects on the growth of bladder cancer cells by disruption of lysosome function and elevation of apoptotic cell death.

MP36-11 AUTOPHAGY IS ACTIVATED IN HUMAN BLADDER CANCER AND REQUIRED FOR CANCER CELL GROWTH

INTRODUCTION AND OBJECTIVES: Macroautophagy, also known as type II programmed cell death, is a regulated catabolic pathway to degrade cellular organelles and macromolecules. The role of autophagy in cancer is complex and may differ depending on tumor type or context. Here, we investigated the activated basal autophagy in bladder cancer cells and its roles in maintaining cancer cell growth. METHODS: Human immortalized uroepithelium (SV-Huc-1) and bladder cancer cells including RT-4 (grade I), 5637 (grade II), HT1376 and T24 (grade III) were used. We also included human prostate cancer cells (Rv1 and PC3), breast cancer cell (MCF-7) and embryonic kidney cancer cell (293T) as reference cells. The cell viability was accessed by WST-8. Autophagy was detected by the expression level of LC3-II protein. Human bladder tumor tissue array (TMA; 12 cases, paired with normal tissue) was used to detect the LC3 expression level. Detection of apoptosis level was measured by caspase 3/7 activation, caspase 3 cleavage and TUNEL assays. The ROS generation, mitochondria membrane potential in cells treated with autophagy inhibitors was assayed by staining with H2DCFCA and JC-1 dyes, respectively, and subsequently subjected to flow cytometry analysis. Disruption of lysomome membrane (LMP) by was detected by immunofluorescent of cathepsin-D in cells treated with CQ. RESULTS: We found bladder cancer cells exhibited high basal level of autophagy compared to prostate, breast or embryonic kidney cancer cells. Immunohistochemistry (IHC) detection of LC3 in human bladder TMA showed increased level of LC3 in bladder tumor tissues compared to their paired normal tissues. In the cell-based experiment, we found that autophagy inhibitors alone inhibited bladder cancer cell growth and increased apoptosis. The ROS generation and MMP disruption were not detected in cells treated with CQ or HCQ. Immunofluorescent detection of cathepsin-D in cells treated with CQ showed dispread pattern in the cytosol, suggesting the disruption of LMP in CQ-treated bladder cancer cells. CONCLUSIONS: Our results showed that human bladder cancer exhibits high basal level of autophagy. Autophagy inhibitors showed significant effects on the growth of bladder cancer cells by disruption of lysosome function and elevation of apoptotic cell death.

Study of autophagy-related protein light chain 3 (LC3)-II expression levels in thyroid diseases

Thyroid cancers are the most common malignant tumors of the endocrine system. The survival-promoting role of autophagy in tumor cells has been received universally. This study aimed to explore autophagy-related protein light chain 3 (LC3)-II expression levels in thyroid diseases including papillary thyroid cancer. A total of 45 thyroid samples, including 19 samples of papillary thyroid cancer, 7 samples of nodular goiter, 8 samples of Hashimoto thyroiditis and 11 samples of normal thyroid tissue resected during surgery, were selected and divided into pathological groups using light microscope. Levels of autophagy-related protein LC3-II in four different types of thyroid tissue were tested through Western blot. SPSS19 software was utilized to analyze the research data statistically. LC3-II protein levels in papillary thyroid cancer tissues were lower than that in normal thyroid tissues significantly (P<0.05). Compared with normal thyroid tissue, expression levels of LC3-II protein were higher in samples of Hashimoto thyroiditis and nodular goiter (P<0.05). Multi-factor analysis of variance showed that there was no significant correlation between LC3-II protein levels and patients’ gender of thyroid cancer, while there was significant variation between patients with and without lymph node metastasis. Compared with patients of thyroid cancer without lymph node metastasis, the level of LC3-II protein was lower in patients of thyroid cancer with lymph node metastasis (P<0.05). Detection of LC3-II protein expression levels in thyroid diseases may contribute to the clinical diagnosis and provide theoretic basis for the therapy.

Restoration of klotho expression induces apoptosis and autophagy in hepatocellular carcinoma cells

Klotho has been identified as a tumor suppressor in several human malignancies including hepatocellular carcinoma (HCC). However, the signaling pathways involved in the tumor suppressive role of klotho in HCC have not been reported. Here, we investigated the role of klotho in HCC cell proliferation, apoptosis, autophagy, and invasion, as well as its associated signal transduction pathways. Restoration of klotho gene expression was established by delivering a klotho gene expression vector into the human HCC cell lines HepG2 and MHCC-97-H. Cell viability was measured using a cell counting (CCK-8) assay and apoptosis was analyzed through flow cytometry. Autophagy was measured via LC3-I and LC3-II protein expression levels and tumor cell invasion was assessed using a Matrigel invasion chamber assay. Expression and phosphorylation of several apoptosis and survival related proteins were assessed using Western blot assays. Exogenous klotho gene expression significantly inhibited HCC cell proliferation, induced HCC cell apoptosis, increased LC3-I and LC3-II protein expression in HCC cells, and decreased migration of HCC cells in a Matrigel invasion chamber assay. Exogenous klotho gene expression also down-regulated the phosphorylation levels of the IGF-1 receptor, and the downstream Akt, ERK, and p70S6K proteins. Both apoptosis and autophagy inhibitors decreased klotho-induced apoptosis and autophagy. Klotho is a tumor suppressor that, through the regulation of IGF-1R phosphorylation and subsequent activation of downstream Akt-p70S6K and ERK signaling, regulates HCC tumor cell proliferation, apoptosis, autophagy and invasion.