[Effects of electroacupuncture on ROS-NLRP3 inflammatory pathway and autophagy related proteins in hippocampus of vascular dementia rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on learning-memory ability, ultrastructural changes of hippocampal CA1 neurons, reactive oxygen species (ROS) level, Nod-like receptor protein 3 (NLRP3) and auto-phagy-related proteins expression in the hippocampus of vascular dementia (VD) rats, so as to reveal its partial mechanisms in treating VD. METHODS: Male SD rats were randomly divided into sham operation, model, and EA groups (n=10 rats in each group). The VD model was established by permanent ligation of bilateral common carotid arteries. Rats of the EA group were treated with EA at "Baihui" (GV20), "Dazhui" (GV14) and bilateral "Shenshu" (BL23) for 30 min, once a day for 4 weeks. Morris water maze was used to evaluate the learning and memory ability of rats before modeling, 4 weeks after modeling and after intervention. Transmission electron microscopy (TEM) was used to observe the ultrastructural changes of hippocampal CA1 neurons. The level of ROS in hippocampus was detected by DCFH-DA fluorescence probe. The expressions of NLRP3, autophagy-related protein Beclin1 and microtubule-associated protein 1 light chain 3 (LC3) were measured by Western blot. RESULTS: In comparison with the sham operation group, the average escape latency of rats in the model group was prolonged (P<0.01), and the times of crossing the original platform were reduced (P<0.05), the level of ROS, the expression levels of LC3-Ⅱ/LC3-Ⅰ ratio, Beclin1 and NLRP3 proteins in hippocampus were increased (P<0.01, P<0.05) in the model group. After EA intervention, the average escape latency of rats was significantly shortened (P<0.01), and the times of crossing the original platform were increased (P<0.05), the level of ROS, the expression levels of LC3-Ⅱ/LC3-Ⅰ ratio, Beclin1 and NLRP3 proteins in hippocampus were decreased (P<0.01, P<0.05) in the EA group compared with those of the model group. Outcomes of TEM showed that CA1 neurons in the hippocampus were damaged, chromatin aggregation, mitochondria pyknosis, cristae structure disorder, rough endoplasmic reticulum expanded and degranulated, the number of free ribosomes decreased, and autophagy could be seen in the model group, which were milder in the EA group. CONCLUSION: EA at GV20, GV14 and BL23 can improve the learning and memory abilities of VD rats, alleviate the ultrastructural damage of neurons in hippocampal CA1 area, and repair the damaged neurons. The mechanism may be related to the reduction of ROS level, LC3-Ⅱ/LC3-Ⅰ ratio, NLRP3 and Beclin1 protein expression, the decrease of neuronal autophagy, inhibition of activation of NLRP3 inflammasome and alleviation of central inflammatory response.

Long Non-Coding RNA H19 Expression Correlates with Autophagy Process in Adrenocortical Carcinoma.

Adrenocortical carcinoma (ACC) is characterized by poor prognosis and high mortality. The suppression of the long-non-coding RNA H19, counterbalanced by IGF2 over-expression, leads to down-regulation of the autophagy markers, high proliferation rate and metastatic potential in patients affected by ACC. The administration of the deacetylase inhibitors (DACi) panobinostat, trichostatin A (TSA) and SAHA affected the cell viability of H295R monolayer and spheroids and induced the over-expression of H19 and autophagy transcripts. H19 knock down in H295R cells was not able to modulate the expression level of autophagy transcripts. Instead, H19 knock down was able to impede the ability of DACi to modulate the protein level of the autophagy markers. Furthermore, the administration of higher concentration of DACi was able to down-regulate the protein level of Beclin1 and p62 and to induce the conversion of LC3B-I into the active LC3B-II form, thus confirming an active autophagic process. Neither the active protein level nor the activity of caspases 8 and 3 was prompted by the DACi, thus excluding the involvement of the executioners of apoptosis in H295R decay. The DACi restore H19, the autophagy markers and trigger cell death in ACC cells. The re-activation of autophagy would represent a novel strategy for the treatment of patients affected by this severe malignancy.

S100A8 promotes chemoresistance via augmenting autophagy in B­cell lymphoma cells.

B­cell lymphomas (BCLs) are malignant lymphoid tumours originating from the malignant proliferation and transformation of mature lymphocytes at various stages of differentiation and clonal expansion of the lymphatic and circulatory systems. Efforts to control or even eradicate BCLs are frequently hampered by the development of drug resistance. Autophagy is an evolutionarily conserved biological process of the energy metabolism. By degrading intracellular organelles and proteins, autophagy provides cells with biochemical reaction substrates for the maintenance of homeostasis under nutrient deprivation or other stressful conditions. Accumulating evidence indicates that autophagy plays an important role in chemotherapy resistance. S100A8 is an important member of the calcium­binding protein family that plays an important role in regulating tumour resistance to chemotherapy, while the specific molecular regulatory mechanisms remain unclear. In the present study, by employing three BCL cell lines (Daudi, SUDHL­4 and JeKo­1), it was demonstrated that BCL cells with a strong drug resistance also exhibited active autophagy. In addition, S100A8 was found to be crucial for regulating drug resistance and promoting autophagy in BCL cells. Interference of S100A8 significantly downregulated Bcl­2/adenovirus E1B 19­kDa protein­interacting protein 3 located in the mitochondria and endoplasmic reticulum to further inhibit autophagy. In addition, S100A8 interference markedly inhibited the formation of the BECN1­PI3KC3 complex and promoted B­cell lymphoma 2 expression, which collectively inhibited autophagy.

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

BACKGROUND: 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. OBJECTIVE: In this study, we explored the effect of BECLIN-1 overexpression on tumor growth in mice with esophageal carcinoma and its mechanism. METHODS: 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. RESULTS: 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. CONCLUSION: BECLIN-1 can induce autophagy in esophageal carcinoma Eca109 cells, and it can significantly inhibit the growth of esophageal carcinoma.

Involvement of phosphatase and tensin homolog-induced putative kinase 1-Parkin-mediated mitophagy in septic acute kidney injury.

BACKGROUND: Studies have reported mitophagy activation in renal tubular epithelial cells (RTECs) in acute kidney injury (AKI). Phosphatase and tensin homolog-induced putative kinase 1 (PINK1) and E3 ubiquitin-protein ligase Parkin are involved in mitophagy regulation; however, little is known about the role of PINK1-Parkin mitophagy in septic AKI. Here we investigated whether the PINK1-Parkin mitophagy pathway is involved in septic AKI and its effects on cell apoptosis in vitro and on renal functions in vivo. METHODS: Mitophagy-related gene expression was determined using Western blot assay in human RTEC cell line HK-2 stimulated with bacterial lipopolysaccharide (LPS) and in RTECs from septic AKI rats induced by cecal ligation and perforation (CLP). Autophagy-related ultrastructural features in rat RTECs were observed using electron microscopy. Gain- and loss-of-function approaches were performed to investigate the role of the PINK1-Parkin pathway in HK-2 cell mitophagy. Autophagy activators and inhibitors were used to assess the effects of mitophagy modulation on cell apoptosis in vitro and on renal functions in vivo. RESULTS: LPS stimulation could significantly induce LC3-II and BECN-1 protein expression (LC3-II: 1.72 ±â€Š0.05 vs. 1.00 ±â€Š0.05, P < 0.05; BECN-1: 5.33 ±â€Š0.57 vs. 1.00 ±â€Š0.14, P < 0.05) at 4 h in vitro. Similarly, LC3-II, and BECN-1 protein levels were significantly increased and peaked at 2 h after CLP (LC3-II: 3.33 ±â€Š0.12 vs. 1.03 ±â€Š0.15, P < 0.05; BECN-1: 1.57 ±â€Š0.26 vs. 1.02 ±â€Š0.11, P < 0.05) in vivo compared with those after sham operation. Mitochondrial deformation and mitolysosome-mediated mitochondria clearance were observed in RTECs from septic rats. PINK1 knockdown significantly attenuated LC3-II protein expression (1.35 ±â€Š0.21 vs. 2.38 ±â€Š0.22, P < 0.05), whereas PINK1 overexpression markedly enhanced LC3-II protein expression (2.07 ±â€Š0.21 vs. 1.29 ±â€Š0.19, P < 0.05) compared with LPS-stimulated HK-2 cells. LPS-induced proapoptotic protein expression remained unchanged in autophagy activator-treated HK-2 cells and was significantly attenuated in PINK1-overexpressing cells, but was remarkably upregulated in autophagy inhibitor-treated and in PINK1-depleted cells. Consistent results were observed in flow cytometric apoptosis assay and in renal function indicators in rats. CONCLUSION: PINK1-Parkin-mediated mitophagy might play a protective role in septic AKI, serving as a potential therapeutic target for septic AKI.

Endoplasmic reticulum stress induced autophagy in 6-OHDA-induced Parkinsonian rats.

Both endoplasmic reticulum (ER) stress and autophagy involve in the pathological process of Parkinson's disease (PD). But the relationship between them is not clear in PD. A 6-OHDA-induced parkinsonian rat is recognized as a standard model for many years, and it can be used in experimental study. The glucose regulated protein 78 (GRP78) is a master regulator of ER stress, and the C/EBP homologous binding protein (CHOP) is an indicator of the UPR signaling. Besides, the Beclin-1 is also well known as a regulator of autophagy, and P62 is a specific marker to monitor autophagy. Therefore, we investigated the expressions of GRP78, CHOP, Beclin-1 and P62 in 6-OHDA-induced parkinsonian rat. Unilateral 6-OHDA injection into medial forebrain bundle was used except sham-operated rats. The rats were randomly divided into 6 groups: a sham-operated group; a model group; a 3-methyladenine (3-MA) group, administered 3-MA---autophagy inhibitor; a rapamycin group, administered rapamycin---autophagy inducer; a 4-phenylbutyric acids (4-PBA) group, administered 4-PBA---ER stress inhibitor; a tunicamycin (TM) group, administered TM---ER stress inducer. The results showed that the expressions of GRP78, CHOP and Beclin-1 increased, P62 decreased in model group; the expressions of GRP78 and CHOP were unchanged in 3-MA group and rapamycin group; but the expression of Beclin-1 decreased and P62 increased in 4-PBA group, while the expression of Beclin-1 increased and P62 decreased in TM group. These data suggest that ER stress and autophagy occurred in 6-OHDA-induced parkinsonian rat, and ER stress might induce autophagy. The result is important for the pathological mechanism of PD.

IL-17A inhibits autophagic activity of HCC cells by inhibiting the degradation of Bcl2.

Hepatocellular carcinoma (HCC) is associated with poor prognosis due to many unknowns about its inflammatory microenvironment. As a pivotal proinflammatory cytokine, IL-17A exerts a protective effect on the survival and function of HCC cells. It is widely accepted that IL-17A plays an important role in regulating autophagy. Bcl2, a key molecule promoting the survival of HCC cells, also plays an indispensable role as an autophagy regulator. The aim of this study was to investigate the role of Bcl2 in IL-17A-regulated autophagy of HCC cells. The results showed that IL-17A not only inhibited autophagic activity, but also increased Bcl2 levels in HCC cells under starvation. Besides, IL-17A could prevent the dissociation of autophagy protein Beclin1 from Bcl2-Beclin1 complex upon starvation. Overexpression of Beclin1 rescued the autophagy deficiency of HCC cells in presence of IL-17A. Moreover, RNAi-induced Bcl2 silencing impaired the function of IL-17A in inhibiting the activation of autophagy, subsequently reducing the viability and migration of HCC cells, while the inhibition of Beclin1 by spautin-1 could reduce autophagic activity to a certain degree, thus restoring the viability and migration of HCC cells. In summary, it was suggested that the inhibition of Bcl2 degradation may be an important mechanism by which IL-17A inhibits autophagy response, subsequently maintaining the survival in HCC cells.

A novel combined score of biomarkers in sputum may be an indicator for lung cancer: A pilot study.

BACKGROUND: Lung cancer is a leading cause of morbidity and mortality worldwide and there is an urgent need for sensitive, specific, and reliable biomarkers. METHODS: The study population included 60 patients (31 with lung cancer and 29 with chronic obstructive pulmonary disease [COPD]) and thirty healthy individuals comprised the control group. Measurements of neutrophil, beclin-1, VEGF, ICAM, VCAM, and TNF-alpha levels in induced sputum were analyzed as possible biomarkers for lung cancer. RESULTS: Neutrophil, beclin-1, VEGF, ICAM and TNF-alpha levels of lung cancer patients differed significantly compared to those of COPD patients and healthy controls. A novel combined-score was created which was found to increase the likelihood to belong to the cancer group by 70% (odds-ratio 1.70 CI = 1.310-2.224,p < 0.001). CONCLUSION: Biomarkers of autophagy, angiogenesis and inflammation in lung-cancer patients are significantly different from controls, and combination of these markers may be an indicator for lung cancer.

Loss of Beclin1 Expression and Nrf2 Overexpression are Associated with Poor Survival of Patients with Non-Small Cell Lung Cancer.

BACKGROUND: Nrf2 pathway and autophagy are abnormally activated in response to cellular stress in various types of human cancers. In this study, we selected Beclin1 as an enter point to discuss the relationship between Nrf2 pathway and autophagy, and defined their associations with clinic pathological features and survival of the patients. METHOD: NSCLC specimens were processed for immunohistochemical and qRT-PCR to analyses the expression of Beclin1 and Nrf2. Kaplan-Meier method and log-rank test were used in the survival data. RESULTS: Beclin1 protein level was found to be significantly associated with more advanced TNM stage (P = 0.035), lymph node metastasis (P = 0.017) and distant metastasis (P = 0.005). The expression of Nrf2 protein was associated with larger tumor size (P = 0.032), more advanced TNM stage (P = 0.011), lymph node metastasis (P = 0.045) and distant metastasis (P = 0.013). Beside there was a strong inverse relationship between Beclin1 and Nrf2 expression in the NSCLC tissues. Distant metastasis, Beclin1, Nrf2, and Beclin1-/Nrf2+ expression was conformed to be independent prognostic factors of patients. CONCLUSION: Both Nrf2 overexpression and Beclin1 lower-expression are independent indicators of a poor prognosis in NSCLC patients.

Autophagy-related gene LC3 expression in tumor and liver microenvironments significantly predicts recurrence of hepatocellular carcinoma after surgical resection.

BACKGROUND: The role of autophagy-related markers as the prognostic factor of post-operative hepatocellular carcinoma (HCC) recurrence remained controversial. METHODS: Overall, 535 consecutive HCC patients undergoing curative resection from 2010 to 2014 were followed and classified with early (ER, <2 years) or late recurrence (LR). Autophagy-related markers, LC3, Beclin-1, and p62 expression was immunohistochemically assessed in HCC and adjacent non-tumor (ANT) tissues. RESULTS: HCC recurred in 245 patients: 116 with ER and 129 with LR. The cumulative incidence of recurrence at 1, 3, 5, and 7 years was 9.7%, 33.9%, 53.3%, and 66.3%, respectively. In multivariate analysis, HCC recurrence was significantly associated with low LC3 expression in tumor and ANT tissues, HCC tissues only and ANT tissues only (hazard ratio/95% confidence interval: 6.12/2.473-17.53, 4.18/1.285-13.61, and 1.89/1.299-2.757) and macrovascular invasion (1.63/1.043-2.492) and cirrhosis (1.59/1.088-2.326). ER was significantly associated with low LC3 expression in tumor and ANT tissues, HCC tissues only and ANT tissues only (6.54/2.934-15.81, 3.26/1.034-10.27, and 2.09/1.313-3.321) and macrovascular and microvascular invasion (2.65/1.306-5.343 and 2.55/1.177-5.504). LR was significantly associated with low LC3 expression in tumor and ANT tissues, HCC tissues only and ANT tissues only (5.02/1.372-18.83, 3.19/1.13-12.09, and 1.66/1.051-2.620) and cirrhosis (1.66/1.049-2.631). Patients with low and high LC3 expression in tumor and ANT tissues showed a 5-year cumulative recurrence of 94.3% and 41.7%, respectively (p < 0.001). CONCLUSIONS: The high LC3 expression in the tumor and liver microenvironments is significantly associated with lower HCC recurrence. Furthermore, tumor characteristics and liver microenvironment were also significantly associated with ER and LR, respectively. TRANSLATIONAL IMPACT: The analysis for LC3 expression in both the HCC and ANT tissues could identify patients at risk of HCC recurrence.

Regulation of autophagy by tea polyphenols in diabetic cardiomyopathy.

OBJECTIVE: To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyopathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy. METHODS: Sixty Sprague-Dawley (SD) rats were randomly divided into six groups: a normal control group (NC), an obesity group (OB), a diabetic cardiomyopathy group (DCM), a tea polyphenol group (TP), an obesity tea polyphenol treatment group (OB-TP), and a diabetic cardiomyopathy tea polyphenol treatment group (DCM-TP). After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ultrasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-II, SQSTM1/p62, and Beclin-1 were determined by Western blotting. RESULTS: Compared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-II/I and Beclin-1 increased obviously, whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups (P<0.05). CONCLUSIONS: Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.

Acute Response of Neurons: An Early Event of Neuronal Cell Death After Facial Nerve Injury.

OBJECTIVE: To research the early acute response events of facial nerve injury. METHODS: Sixty male Sprague-Dawley rats were randomly divided into 2 groups. Facial nerve anastomosis was performed for rats in study group. Rats in control group underwent the same surgical procedure, but without cutting off the facial nerve. Before nerve anastomosis and at days 1, 3, 7, 14, and 28 after nerve anastomosis, 5 rats of each group were selected and right side brainstem tissue samples containing the facial nerve nucleus were obtained. Hematoxylin and eosin (H&E) staining and TUNEL detection was performed to observe facial neurons changes. Facial neurons mortality and apoptosis were studied. Expression of caspase-3, LC3, and Beclin1 was detected with Western blot assay. RESULTS: In study group on day 7 day after nerve anastomosis, Nissl body dissolution and apoptotic facial neurons were significantly increased, the typical polygonal shape and swollen cells disappeared, the number of facial neurons was significantly lower, and the number of apoptotic facial neurons was significantly higher (P < 0.01). In addition, facial neuron mortality rate was significantly increased at day 7, reaching the peak at day 14. Expression of caspase-3, LC3, and Beclin1 was also significantly up-regulated after nerve anastomosis. CONCLUSION: Nissl body dissolution, typical polygonal shape disappearing, cell swelling, facial neuron mortality and apoptosis, and up-regulated expression of caspase-3, LC3, and Beclin1 are the early events of cell death after facial nerve injury, which are the important precursors to facial nerve injury.

Acquired inhibition of microRNA-124 protects against spinal cord ischemia-reperfusion injury partially through a mitophagy-dependent pathway.

OBJECTIVE: Mitophagy results in selective clearance of damaged mitochondria. We investigated whether mitophagy was involved in the neuroprotection by inhibiting microRNA (miRNA)-124 on ischemic spinal cords. METHODS: Inhibition of miRNA-124 was conducted by intrathecal injection of lentivirus vectors containing antagomiR-124. Spinal cord ischemia was induced in rats by crossclamping the descending aorta just distal to the left subclavian artery for 14 minutes. Hind-limb motor function was assessed with the motor deficit index (MDI). Lumbar spinal cords were harvested for ultrastructural, histologic examinations, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling staining. Mitophagy was evaluated by expressions of beclin-1 and LC3-II in mitochondria. Expressions of inhibitory member of the apoptosis-stimulating proteins of p53 family, p53, beclin-1, LC3-II, and miRNA-124 were measured by Western blot and quantitative real-time polymerase chain reaction. Mitophagy was inhibited by the antagonist of 3-methyladenine. RESULTS: Compared with control animals, antagomiR-124 significantly inhibited expressions of miRNA-124 (P < .01) and p53 (P < .05) and enhanced expressions of inhibitory member of the apoptosis-stimulating proteins of p53 family, becline-1 and LC3-II (P < .01, respectively) in spinal cords. MDI at 6, 12, 24, and 48 hours after reperfusion were markedly lower in antagomiR-124 group (P < .01, vs control group, respectively). More motor neurons and less apoptotic cells were detected in lumbar spinal cords of antagomiR-124 group (P < .01 vs control group). Administration of 3-methyladenine completely abolished enhancements of mitochondrial becline-1 and LC3-II by antagomiR-124 (P < .01 vs antagomiR-124 group) and partially inhibited effects of antagomiR-124 on MDI, number of motor neurons, and apoptotic cells (P < .01 or < .05 vs control group and antagomiR-124 group, respectively). CONCLUSIONS: Inhibition of miRNA-124 exerts neuroprotection on spinal cords against ischemia-reperfusion injury, possibly by induction of mitophagy and antiapoptotic effects.

Ultrasensitive multiplexed immunoassay of autophagic biomarkers based on Au/rGO and Au nanocages amplifying electrochemcial signal.

A novel sandwich-assay electrochemical immunosensor for simultaneous determination of autophagic biomarkers was introduced for the first time, the gold-reduced grapheme oxide nanocomposite (Au/r-GO) set as a good conductive platform with super high specific area, and provided more binding sites for the both antibodies of Beclin-1 and LC3B-II. While Au nanocages (AuNCs) served as good conductive platform to encapsulate a large amount of redox probe and secondary antibodies for signal amplification, due to the abundant reactive oxygen functional groups on its surface. Through differential pulse voltammetry (DPV) measurements, two separate signals can be detected directly in a single run, which represent the existence of Belin-1 and LC3B-II. Under optimized conditions, the electrochemical immunosensor exhibited good sensitivity and selectivity for the simultaneous determination of Beclin-1 and LC3B-II with linear ranges of 0.1-100 ng/mL. The detection limit for Beclin-1 and LC3B-II is 0.02 and 0.03 ng/mL respectively. This method was also applied for the analysis of Beclin-1 and LC3B-II levels in experimental cellular protein lysates, and the results were in good agreement with those of enzyme linked immunosorbent assay. This approach gives a promising simple, sensitive and quantitative strategy for the detection of autophagy.

Methods to Study the BECN1 Interactome in the Course of Autophagic Responses.

Autophagy is an extremely dynamic process that mediates the rapid degradation of intracellular components in response to different stress conditions. The autophagic response is executed by specific protein complexes, whose function is regulated by posttranslational modifications and interactions with positive and negative regulators. A comprehensive analysis of how autophagy complexes are temporally modified upon stress stimuli is therefore particularly relevant to understand how this pathway is regulated. Here, we describe a method to define the protein-protein interaction network of a central complex involved in autophagy induction, the Beclin 1 complex. This method is based on the quantitative comparison of protein complexes immunopurified at different time points using a stable isotope labeling by amino acids in cell culture approach. Understanding how the Beclin 1 complex dynamically changes in response to different stress stimuli may provide useful insights to disclose novel molecular mechanisms responsible for the dysregulation of autophagy in pathological conditions, such as cancer, neurodegeneration, and infections.

Evidence for the recruitment of autophagic vesicles in human brain after stroke.

Autophagy is a homeostatic process for recycling proteins and organelles that is increasingly being proposed as a therapeutic target for acute and chronic neurodegenerative diseases, including stroke. Confirmation that autophagy is present in the human brain after stroke is imperative before prospective therapies can begin the translational process into clinical trials. Our current study using human post-mortem tissue observed an increase in staining in microtubule-associated protein 1 light chain 3 (LC3), sequestosome 1 (SQSTM1; also known as p62) and the increased appearance of autophagic vesicles after stroke. These data confirm that alterations in autophagy take place in the human brain after stroke and suggest that targeting autophagic processes after stroke may have clinical significance.