Upregulation Of Autophagy-related Proteins Research Articles

Autophagy Inhibition and Sensitization to Cisplatin in Esophageal Cancer Stem-Like Cells via All-trans Retinoic Acid-induced miR-30a.

Providing insights into the chemoresistance of esophageal squamous cell carcinoma (ESCC) and its dependence on chemotherapy-induced autophagy. Autophagy is induced during chemotherapy of cancer cells, promoting resistance to anti-cancer treatments. The objective of this study is to investigate the modulation of microRNA-30a (miR-30a), a known regulator of autophagy, in ESCC cells by all-trans retinoic acid (ATRA). Treatment involved ESCC cells KYSE-30 and TE8 with cis-dichloro-diamine platinum (CDDP), enriching CDDP-surviving cells (CDDP-SCs). qRT-PCR and dual luciferase reporter assay (DLRA) were employed to evaluate miR-30a expression and its interaction with Beclin-1 (BECN1) in both CDDP-SCs and those treated with ATRA. Chemotherapy using CDDP led to a significant decrease in miR-30a expression within ESCC cells. Increased autophagy levels were identified in cancer cells exhibiting stem cell-like properties, characterized by the overexpression of specific stem cell markers. These results suggest that the downregulation of miR-30a induced by CDDP treatment may represent a potential underlying mechanism for increased autophagic activity, as evidenced by the upregulation of autophagy-related proteins, such as BECN1 and an elevated LC3-II/LC3-I ratio. ATRA treatment elevated miR-30a expression and disrupted hallmark cancer stem cell (CSC) features in ESCC cells. Further investigations demonstrated that increased miR-30a expression led to a reduction in the expression of its target gene, BECN1, and attenuated BECN1-mediated autophagy. This resulted in an augmentation of CDDP-induced apoptosis in ESCC cells and a G2/M cell cycle arrest. CDDP chemotherapy reduced miR-30a, promoting ESCC cell resistance through autophagy and CSC-like features, a process that may be modulated by ATRA.

Cadmium induces apoptosis of mouse spermatocytes through JNK activation and disruption of autophagic flux

Cadmium has been reported to accumulate primarily in spermatogonia and spermatocytes. Exposure to cadmium results in male reproductive toxicity via germ-cell apoptosis and impaired autophagy. Apoptosis and autophagy are two physiologically conserved events that maintain cellular homeostasis. However, the precise role of autophagy in cadmium-induced apoptosis of male germ cells has yet to be addressed. The present study aimed to investigate the impact of cadmium exposure on the cytotoxicity of GC-2 spd cells, a mouse spermatocyte cell line. The results showed that cadmium exposure caused apoptotic cell death and the accumulation of autophagosomes, along with the up-regulation of ATG proteins in GC-2 spd cells. It was demonstrated that the cadmium-induced accumulation of autophagosomes contributes to the apoptosis of GC-2 spd cells. This notion is supported by the findings that the autophagy inhibitor 3-MA reduced accumulation of autophagosomes and apoptotic cell death. Conversely, the apoptosis inhibitor Z-VAD-FMK inhibited apoptosis but had little effect on the accumulation of autophagosomes. Cadmium may impede the fusion of autophagosomes with lysosomes, leading to the autophagosome buildup. Additionally, we found that the JNK pathway mediates transcriptional induction of several autophagy-related (ATG) genes involved in autophagosome formation. The cadmium-activated JNK pathway regulates apoptosis by mediating the autophagosome formation. Treatment of cells with the JNK inhibitor SP600125 attenuated the accumulation of autophagosomes, the upregulated expression of autophagosome-associated proteins and apoptotic cell death induced by cadmium. Overall, these findings suggest that cadmium enhances apoptosis of GC-2 spd cells by activating the JNK pathway and inhibiting autophagic flux.

Hypoxia improves self-renew and migration of urine-derived stem cells by upregulating autophagy and mitochondrial function through ERK signal pathway

Urine-derived stem cells (USCs) are autologous stem cells with self-renewal ability and multi-lineage differentiation potential. Our previous studies have shown that hypoxia preconditioning can improve self-renewal and migration abilities of USCs by up-regulating autophagy. The purpose of this study was to investigate the specific mechanism by which hypoxia treatment promotes the biological function of USCs. We found that hypoxia treatment upregulated the expression of phosphralated ERK protein without affecting the expression of total ERK protein. Inhibiting ERK signaling with the PD98059 inhibitor decreased cell proliferation, migration and colony formation during hypoxia treatment. Hypoxia increased ATP production, mitochondrial membrane potential and mt-DNA copy number, which were reversed by inhibiting the ERK signal. Additionally, the number of autophagosomes and autophagic lysosomes was significantly lower in PD98059 group than in the hypoxia group. PD98059 treatment inhibited the up-regulation of autophagy related proteins induced by hypoxia. Therefore, this study suggests that hypoxia improves the self-renewal and migration abilities of USCs by upregulating autophagy and mitochondrial function through ERK signaling pathway. This finding may provide a new therapeutic mechanism for hypoxia pretreated USCs as a source of stem cell transplantation.

MicroRNA-224-5p nanoparticles balance homeostasis via inhibiting cartilage degeneration and synovial inflammation for synergistic alleviation of osteoarthritis

MicroRNAs play a crucial role in regulating cartilage extracellular matrix (ECM) metabolism and are being explored as potential therapeutic targets for osteoarthritis (OA). The present study indicated that microRNA-224-5p (miR-224-5p) could balance the homeostasis of OA via regulating cartilage degradation and synovium inflammatory simultaneously. Multifunctional polyamidoamine dendrimer with amino acids used as efficient vector to deliver miR-224-5p. The vector could condense miR-224-5p into transfected nanoparticles, which showed higher cellular uptake and transfection efficiency compared to lipofectamine 3000, and also protected miR-224-5p from RNase degradation. After treatment with the nanoparticles, the chondrocytes showed an increase in autophagy rate and ECM anabolic components, as evidenced by the upregulation of autophagy-related proteins and OA-related anabolic mediators. This led to a corresponding inhibition of cell apoptosis and ECM catabolic proteases, ultimately resulting in the alleviation of ECM degradation. In addition, miR-224-5p also inhibited human umbilical vein endothelial cells angiogenesis and fibroblast-like synoviocytes inflammatory hyperplasia. Integrating the above synergistic effects of miR-224-5p in regulating homeostasis, intra-articular injection of nanoparticles performed outstanding therapeutic effect by reducing articular space width narrowing, osteophyte formation, subchondral bone sclerosis and inhibiting synovial hypertrophy and proliferation in the established mouse OA model. The present study provides a new therapy target and an efficient intra-articular delivery method for improving OA therapy. Statement of significanceOsteoarthritis (OA) is the most prevalent joint disease worldwide. Gene therapy, which involves delivering microRNAs, has the potential to treat OA. In this study, we demonstrated that miR-224-5p can simultaneously regulate cartilage degradation and synovium inflammation, thereby restoring homeostasis in OA gene therapy. Moreover, compared to traditional transfection reagents such as lipofectamine 3000, G5-AHP showed better efficacy in both microRNA transfection and protection against degradation due to its specific surface structure. In summary, G5-AHP/miR-224-5p was developed to meet the clinical needs of OA patients and the high requirement of gene transfection efficiency, providing a promising paradigm for the future application and development of gene therapy.

Non-cytopathic bovine viral diarrhoea virus 2 induces autophagy to enhance its replication.

Bovine viral diarrhoea virus (BVDV) is an important viral pathogen that has an economic impact on the livestock industry worldwide. Autophagy is one of the earliest cell-autonomous defence mechanisms against microbial invasion, and many types of viruses can induce autophagy by infecting host cells. The aim of this study was to identify the role of autophagy in the pathogenesis of non-cytopathic (ncp) BVDV2 infection. Madin-Darby bovine kidney (MDBK) cells were treated with ncp BVDV2, rapamycin, or 3-methyladenine (MA) and ncp BVDV2 and then incubated at 37°C for 24h. Cells were harvested, and the effects of autophagy were determined by transmission electron microscopy (TEM), confocal laser microscopy, western blotting and qRT-PCR. Apoptotic analysis was also performed using western blotting and flow cytometry. In ncp BVDV2-infected MDBK cells, more autophagosomes were observed by TEM, and the number of microtubule-associated protein 1 light chain 3B (LC3B) with green fluorescent protein puncta was also increased. The ncp BVDV2-infected cells showed significantly enhanced conversion of LC3-I to LC3-II, as well as upregulation of autophagy-related proteins, including ATG5 and Beclin 1, and substantial degradation of p62/SQSTM1. These results are similar to those induced by rapamycin, an autophagy inducer. E2 protein expression, which is associated with viral replication, increased over time in ncp BVDV2-infected cells. Inhibition of autophagy by 3-MA in ncp BVDV2-infected MDBK cells downregulated the expressions of LC3-II, ATG5 and Beclin 1 and prevented the degradation of p62/SQSTM1. Moreover, the expressions of phosphorylated Akt and procaspase-3 were significantly increased in ncp BVDV2-infected cells. In addition, the mRNA level of protein kinase R (PKR) was significantly reduced in ncp BVDV2-infected cells. Our results demonstrate that ncp BVDV2 infection induced autophagy in MDBK cells via anti-apoptosis and PKR suppression. Therefore, autophagy may play a role in establishing persistent infection caused by ncp BVDV.

MRTF-A alleviates myocardial ischemia reperfusion injury by inhibiting the inflammatory response and inducing autophagy.

Myocardin-related transcription factor A (MRTF-A) has an inhibitory effect on myocardial infarction; however, the mechanism is not clear. This study reveals the mechanism by which MRTF-A regulates autophagy to alleviate myocardial infarct-mediated inflammation, and the effect of silent information regulator 1 (SIRT1) on the myocardial protective effect of MRTF-A was also verified. MRTF-A significantly decreased cardiac damage induced by myocardial ischemia. In addition, MRTF-A decreased NLRP3 inflammasome activity, and significantly increased the expression of autophagy protein in myocardial ischemia tissue. Lipopolysaccharide (LPS) and 3-methyladenine (3-MA) eliminated the protective effects of MRTF-A. Furthermore, simultaneous overexpression of MRTF-A and SIRT1 effectively reduced the injury caused by myocardial ischemia; this was associated with downregulation of inflammatory factor proteins and when upregulation of autophagy-related proteins. Inhibition of SIRT1 activity partially suppressed these MRTF-A-induced cardioprotective effects. SIRT1 has a synergistic effect with MRTF-A to inhibit myocardial ischemia injury through reducing the inflammation response and inducing autophagy.

Taxifolin blocks monosodium urate crystal-induced gouty inflammation by regulating phagocytosis and autophagy.

Gout is a chronic disease caused by monosodium urate (MSU) crystal deposition in the joints and surrounding tissues. We examined the effects of Taxifolin, a natural flavonoid mainly existing in vegetables and fruits, on MSU-induced gout. Pretreatment with Taxifolin significantly reduced IL-1β, Caspase-1 and HMGB1 levels, upregulation of autophagy-related protein, LC3, as well as improved phagocytosis of macrophages. This study indicated that Taxifolin-attenuated inflammatory response in MSU-induced acute gout model by decreasing pro-inflammatory cytokine production and promoting the autophagy and phagocytic capacity of macrophages. Dietary supplementation with Taxifolin induces the autophagy and attenuated inflammatory response, which in consequence modulates acute gout. A preventive strategy combining dietary interventions with Taxifolin may offer a potential therapeutic alternative to pharmacological treatment to reduce inflammatory response to gout.

Vitamin D receptor deficiency increases systolic blood pressure by upregulating the renin-angiotensin system and autophagy.

The vitamin D receptor (VDR) may regulate blood pressure via multiple pathways. The present study investigated the underlying mechanism by which VDR deficiency increases blood pressure. A total of 16 8-week-old male littermate mice were randomly divided into the VDR knockout and wild-type groups (VDR-/- and VDR+/+, respectively). Blood pressure was measured using a four-channel PowerLab data acquisition and ADI software analysis system. After euthanasia, vascular smooth muscle cells (VSMCs) were isolated from the VDR-/- and VDR+/+ mice. Oxidative stress, renin-angiotensin system (RAS) activation and autophagy markers were measured in the isolated VSMCs using reverse transcription-quantitative PCR (RT-qPCR), western blotting and transmission electron microscopy (TEM) assays. Mean systolic pressure was significantly higher in the VDR-/- mice compared with the VDR+/+ mice. RT-qPCR and western blotting analyses indicated that RAS markers (angiotensin II and II type 1 receptor) were significantly upregulated, oxidative stress was increased (evidenced by reduced superoxide dismutase and peroxiredoxin-4) and autophagy was activated (upregulation of autophagy related protein 7, Beclin 1 and microtubule-associated proteins 1A/1B light chain 3A) in the VDR-/- VSMCs compared with the VDR+/+ VSMCs. TEM demonstrated that there were more autophagy bodies in the VDR-/- VSMCs compared with the VDR+/+ VSMCs. In conclusion, VDR deficiency was associated with high blood pressure. The mechanism underlying the increase in blood pressure caused by VDR deficiency may involve activation of the RAS, as well as increased oxidative stress and autophagy of VSMCs.

The effects of autophagy in rat tracheal epithelial cells induced by silver nanoparticles.

The massive use of silver nanoparticles (AgNPs) is potentially harmful to exposed humans. Although previous studies have found that AgNPs can induce cell autophagy, few studies have focused on the toxic pathways and mechanisms of autophagy induced by AgNPs in rat respiratory epithelial (RTE) cells. In this study, RTE cells were exposed to two kinds of AgNPs in vitro to ascertain the influence of mTOR-autophagy pathway-associated protein expression, including Beclin1, LC3B, Atg5, and Atg7. After exposure to different sizes and concentrations of AgNPs for 12 h, the uptake of silver in RTE cells reached 0.45 μg/L to 1.11 μg/L, indicating that AgNPs can enter RTE cells, leading to toxic effects. Our study found that this toxic effect was related to autophagy caused by ROS accumulation that was mediated by the mTOR pathway. With increasing AgNP exposure concentrations, the expression of p-mTOR was significantly downregulated, and expression of the autophagy-related proteins Beclin1, LC3B, Atg5, and Atg7 was significantly increased in RTE cells in all exposed groups. At a concentration of 1000 μg/L, the expression of LC3BII/LC3BI in all exposed groups was 24.49 times and 12.71 times that of the control, and the expression of Atg7 in all exposed groups was 23.21 times and 13.21 times that of the control. The upregulation of autophagy-related proteins in the AgNP-10 nm exposure groups was greater than that of the AgNP-100 nm exposure group. In summary, the mTOR pathway mediates AgNP-induced autophagy in RTE cells, which leads to damage to the respiratory system barrier and human health risks. This study can facilitate the development of prevention and intervention policies against adverse consequences induced by AgNPs.

A potential mechanism associated with lead-induced spermatogonia and Leydig cell toxicity and mitigative effect of selenium in chicken

Lead (Pb) is a toxic heavy metal pollutants and can damage male reproductive function. Selenium (Se) possesses an ability of antagonizing Pb toxicity. However, biological events in the process of Pb toxicity and mitigative effect of Se are not well understood. The aim of present research was to investigate potential mechanism of Se against Pb toxicity from the perspective of oxidative stress, heat shock response and autophagy in the spermatogonia and Leydig cell of chicken. The cells from one-day-old male Hyline chickens were treated with Se (0.5 μmol/L) and/or Pb (20 μmol/L) for 24 h, respectively. Cell viability, cell ultrastucture, Pb and Se concentrations, testosterone level, oxidative stress indicators and relative expression of heat shock proteins (HSPs) and autophagy-related genes were measured. The results showed that spermatogonia was more tolerant to Pb than Leydig cell; cell injury was confirmed via histological assessment, cell viability and testosterone level; oxidative stress was further indicated by the decrease of catalase, glutathione peroxidase, glutathione-s-transferase and superoxide dismutase activities and the increase of malondialdehyde and reactive oxygen species contents. Pb increased expression of HSPs (27, 40, 60, 70 and 90). Meanwhile Pb induced autophagy through up-regulation of autophagy-related proteins 5, Beclin 1, Dynein, light chain 3 (LC3)-I and LC3-II and down-regulation of mammalian target of rapamycin in two type cells of chicken. However, Se intervention mitigated the aforementioned alterations caused by Pb. In conclusion, Pb led to oxidative stress, which triggered heat shock response and autophagy; Se administration mitigated reproductive toxicity of Pb through strengthening antioxidant defense in the spermatogonia and Leydig cell of chicken.

Bisphenol A increases TLR4-mediated inflammatory response by up-regulation of autophagy-related protein in lung of adolescent mice

In previous studies we found that bisphenol A (BPA) aggravated OVA-induced lung inflammation. The aim of this research was to determine whether BPA exposure alone also induced inflammatory response in the lungs, which mechanism was associated with TLR4/NF-κB signaling pathway and the activation of mTOR-mediated autophagy. Female C57BL/6 mice aged 4 weeks were randomly divided into three groups (10/group): control group, 0.1 and 0.2 μg mL−1 BPA groups. BPA induced the pathological changes in the lung and increased the levels of cytokines and inflammatory cells, as well as affected autophagy related proteins expression. In addition, the RAW264.7 cell culture experiment was conducted in order to confirm the role of autophagy. We found that BPA can enhance autophagy flux by enhancing autophagosome formation. It was further confirmed the details of the mechanism of action with chloroquine (CQ, a compound that inhibits the fusion of autophagosomes and lysosomes) intervention. The inhibition of autophagy led to down-regulation of expression levels associated with inflammation. This research results indicated that BPA induced inflammatory response in vitro and in vivo, and its mechanism may be related to TLR4/NF-κB signaling pathway and the activation of mTOR-mediated autophagy. After autophagy was suppressed, the inflammatory response also weakened. Our findings provide a new perspective into the mechanisms underlying inflammatory responses induced by the environmental exposure. These findings indicate that therapeutic strategies targeting autophagy may provide a new method for the treatment of inflammatory diseases.

The role of TLR4 in up-regulation of autophagy-related protein and MMP9, MMP14 expression via EMMPRIN stimulated THP-1 macrophages

This study investigated the mechanism of toll-like receptor 4(TLR4) in up-regulating autophagy-related protein and matrix metalloproteinase 9(MMP9), MMP14 expression in THP-1 macrophages which were stimulated by Extracellular Matrix Metalloproteinase Inducer (EMMPRIN).

MicroRNA-30a Targets ATG5 and Attenuates Airway Fibrosis in Asthma by Suppressing Autophagy.

Asthma is the most common chronic disease of childhood, chronic airway inflammation; bronchial tissue fibrosis, is a pathological feature common to children asthma, and an emerging data has indicted that autophagy plays critical roles in airway inflammation and fibrosis-mediated airway remodeling. The aim of this study was to examine whether the antifibrotic effect of epithelial microRNAs (miRNAs) relies on regulating autophagy-mediated airway remodeling and to identify the factors involved and the underlying mechanisms. Our results showed miR-30a were downregulated in children with asthma and ovalbumin (OVA) mouse model in parallel with the upregulation of autophagy-related proteins; moreover, we observed miR-30a inhibited the autophagy by downregulated autophagy-related 5 (ATG5). Then, we observed that overexpression of miR-30a suppressed the fibrogenesis and autophagic flux which was stimulated by interleukin-33 (IL-33) in bronchial epithelial cells. In vivo experiments showed that miR-30a overexpression decreased airway remodeling by decreased autophagy. This study uncovered a previously unrecognized antifibrotic role of miR-30a in asthma, in IL-33-induced lung epithelial cells in vitro, and in a murine model of OVA-induced airway inflammation in vivo and explored the underlying mechanisms.

Investigating and re-evaluating the role of glycogen synthase kinase 3 beta kinase as a molecular target for cardioprotection by using novel pharmacological inhibitors.

Glycogen synthase kinase 3 beta (GSK3β) link with the mitochondrial Permeability Transition Pore (mPTP) in cardioprotection is debated. We investigated the role of GSK3β in ischaemia (I)/reperfusion (R) injury using pharmacological tools. Infarct size using the GSK3β inhibitor BIO (6-bromoindirubin-3'-oxime) and several novel analogues (MLS2776-MLS2779) was determined in anaesthetized rabbits and mice. In myocardial tissue GSK3β inhibition and the specificity of the compounds was tested. The mechanism of protection focused on autophagy-related proteins. GSK3β localization was determined in subsarcolemmal (SSM) and interfibrillar mitochondria (IFM) isolated from Langendorff-perfused murine hearts (30'I/10'R or normoxic conditions). Calcium retention capacity (CRC) was determined in mitochondria after administration of the inhibitors in mice and in vitro. The effects of the inhibitors on mitochondrial respiration, reactive oxygen species (ROS) formation, ATP production, or hydrolysis were measured in SSM at baseline. Cyclosporine A (CsA) was co-administered with the inhibitors to address putative additive cardioprotective effects. Rabbits and mice treated with MLS compounds had smaller infarct size compared with control. In rabbits, MLS2776 and MLS2778 possessed greater infarct-sparing effects than BIO. GSK3β inhibition was confirmed at the 10th min and 2 h of reperfusion, while up-regulation of autophagy-related proteins was evident at late reperfusion. The mitochondrial amount of GSK3β was similar in normoxic SSM and IFM and was not altered by I/R. The inhibitors did not affect CRC or respiration, ROS and ATP production/hydrolysis at baseline. The co-administration of CsA ensured that cardioprotection was CypD-independent. Pharmacological inhibition of GSK3β attenuates infarct size beyond mPTP inhibition.

Inhibiting Receptor of Advanced Glycation End Products Attenuates Pressure Overload-Induced Cardiac Dysfunction by Preventing Excessive Autophagy.

The receptor for advanced glycation end products (RAGE) is involved in heart failure (HF) by mediating diverse pathologic processes, including the promotion of inflammation and autophagy. However, the role of RAGE in pressure overload-induced HF is not well understood. We found that stimulation of RAGE triggered the death of neonatal rat ventricular myocytes (NRVMs), while cell death was alleviated by ATG5 knockdown. Using transverse aortic constriction (TAC) in mice as a model of pressure overload-induced HF, we demonstrated that RAGE knockout or RAGE blockade attenuated cardiac hypertrophy and fibrosis as well as cardiac dysfunction at 8 weeks after TAC. Importantly, RAGE knockout reversed upregulation of autophagy related proteins (LC3BII/I and Beclin 1) and reduced cardiomyocyte death, indicating that excessive autophagy after TAC was inhibited. Moreover, RAGE knockout or blockade reduced the upregulation of pp65-NFκB and BNIP3, which mediate autophagy. Taken together, these results suggest that RAGE plays an important role in the progression of HF by regulating autophagy. Therefore, inhibition of the RAGE-autophagy axis could be a promising new strategy for treatment of heart failure.

Ginkgolide K promotes astrocyte proliferation and migration after oxygen-glucose deprivation via inducing protective autophagy through the AMPK/mTOR/ULK1 signaling pathway

Ischemic stroke is the leading cause of death around the world. Ginkgolide K (GK) has been used to treat ischemic stroke due to its neuroprotective potential. However, the molecular mechanism underlying the neuroprotective effect of GK in ischemic stroke is still almost blank. In this study, astrocytes were divided into four groups: control group, oxygen-glucose deprivation (OGD) group, OGD + GK group and OGD + GK + Compound C (CC) group. The viability and proliferation of astrocytes were examined by Cell Counting Kit-8 assay and 5-ethynyl-20-deoxyuridine (EdU) assay, respectively. Transwell migration and wound scratch assays were conducted to evaluate astrocyte migration. The protein expression in astrocytes were determined by western blot assay. We found that GK pretreatment promoted astrocyte proliferation and migration after OGD as shown by the increase in the viability of astrocytes, glial fibrillary acidic protein level, the number of EdU positive cells and migrated cells, and the migration distance. GK pretreatment induced autophagy after OGD, as indicated by upregulation of autophagy-related protein 7, Beclin-1 protein and increase of microtubule-associated protein 1 light chain 3 (LC3)-II/LC3-I, and downregulation of p62 protein. Moreover, GK pretreatment activated the AMP activated protein kinase (AMPK)/mammalian target of rapamycin (m-TOR)/ULK1 pathway in astrocytes following OGD. Notably, CC treatment blocked the promotory effect of GK on astrocyte proliferation and migration after OGD. Collectively, GK promoted astrocyte proliferation and migration after OGD via inducing protective autophagy through the AMPK/mTOR/ULK1 signaling pathway. Our findings suggested that GK might be a potential agent for cerebral ischemia/reperfusion injury.

Protective effects of heme oxygenase-1-transduced bone marrow-derived mesenchymal stem cells on reduced-size liver transplantation: Role of autophagy regulated by the ERK/mTOR signaling pathway

Autophagy is a critical lysosomal pathway that degrades cytoplasmic components to maintain cell homeostasis and provide substrates for energy metabolism. A study revealed that heme oxygenase-1 (HO-1)-transduced bone marrow-derived mesenchymal stem cells (BM-MSCs) could protect 50% reduced-size liver transplantation (RSLT) in a rat model. However, the mechanisms remain mostly unknown. The aim of the present study was to explore the effects and related mechanism of autophagy on the protection conferred by HO-1-transduced BM-MSCs (HO-1/BM-MSCs) on 50% RSLT in a rat model. The authors established an acute rejection model following 50% RSLT in rats, with recipients divided into three groups receiving treatment with BM-MSCs, HO-1/BM-MSCs or normal saline (NS) injected through the dorsal penile vein. Transplanted liver tissues at 0, 1, 3, 5, 7, 10 and 14 days following transplantation were acquired for further analysis. The results indicated that the expression of autophagy-related proteins LC3 and Beclin-1 increased, the levels of ERK and p-ERK increased, and the levels of mammalian target of rapamycin (mTOR) and p-mTOR decreased in the HO-1/BM-MSCs. These observations indicated that autophagy is involved in the protective effects of HO-1/BM-MSCs on liver grafts following RSLT, possibly via upregulation of autophagy-related proteins through the ERK/mTOR signaling pathway.

MicroRNA-34/449 targets IGFBP-3 and attenuates airway remodeling by suppressing Nur77-mediated autophagy

Autophagy plays critical roles in airway inflammation and fibrosis-mediated airway remodeling and many factors including proinflammatory cytokines and inflammation related pathways are involved in the process. The aim of the present study was to examine the role of epithelial microRNAs (miRNAs) in autophagy-mediated airway remodeling and to identify the factors involved and the underlying mechanisms. Serum miR-34/449, inflammatory factors, and autophagy and fibrosis-related proteins were determined by real-time PCR, enzyme-linked immunosorbent assay and western blotting in 46 subjects with asthma and 10 controls and in the lung epithelial cell line BEAS-2B induced with IL-13 and treated with miRNA mimics. Luciferase assays were used to verify IGFBP-3 as a target of miR-34/449, and immunohistochemistry, immunofluorescence and co-immunoprecipitation were used in vitro and in vivo study. miR-34/449 were downregulated in patients with asthma in parallel with the upregulation of autophagy-related proteins. Proinflammatory factors and fibrosis-related proteins were significantly higher in asthma patients than in healthy controls. IL-13 induction promoted autophagy and upregulated miR-34/449 in BEAS-2B cells, and these effects were restored by IGFBP-3 silencing. miR-34/449 overexpression suppressed autophagy, decreased fibrosis, activated Akt, downregulated fibrosis-related factors, and downregulated proinflammatory cytokines and nuclear factor κB by targeting IGFBP-3. In vivo experiments showed that miR-34/449 overexpression was associated with Nur77 nuclear translocation and IGFBP-3 downregulation in parallel with decreased airway remodeling by decreased autophagy. miR-34/449 are potential biomarkers and therapeutic targets in asthma. miR-34/449 may contribute to airway inflammation and fibrosis by modulating IGFBP-3 mediated autophagy activation.

The Role of Lipid Droplets in Mortierella alpina Aging Revealed by Integrative Subcellular and Whole-Cell Proteome Analysis

Lipid droplets (LDs) participate in many cellular processes in oleaginous microorganisms. However, the exact function of LDs in the Mortierella alpina aging process remains elusive. Herein, subcellular proteomics was employed to unveil the composition and dynamics of the LD proteome in the aging M. alpina for the first time. More than 400 proteins were detected in LDs and 62 of them changed expression significantly during aging. By combining the LD proteomic data with whole-cell data, we found that the carbohydrate metabolism and de novo lipid biosynthesis were all inhibited during aging of M. alpina mycelia. The up-regulation of fructose metabolism-related enzymes in LDs might imply that LDs facilitated the fructose metabolism, which in turn might cause pyruvate to accumulate and enter malate-pyruvate cycle, and ultimately, provide additional NADPH for the synthesis of arachidonic acid (ARA). Lysophospholipase and lecithinase were up-regulated in LDs during the aging process, suggesting that the phospholipids and lecithin were starting to be hydrolyzed, in order to release fatty acids for the cells. The impairment of the anti-oxidant system might lead to the accumulation of ROS and consequently cause the up-regulation of autophagy-related proteins in LDs, which further induces the M. alpina mycelia to activate the autophagy process.

Preservation of Cognitive Function by Lepidium meyenii (Maca) Is Associated with Improvement of Mitochondrial Activity and Upregulation of Autophagy-Related Proteins in Middle-Aged Mouse Cortex.

Maca has been used as a foodstuff and a traditional medicine in the Andean region for over 2,000 years. Recently the neuroprotective effects of maca also arouse interest of researchers. Decrease in mitochondrial function and decline in autophagy signaling may participate in the process of age-related cognitive decline. This study aimed to investigate if maca could improve cognitive function of middle-aged mice and if this effect was associated with improvement of mitochondrial activity and modulation of autophagy signaling in mouse cortex. Fourteen-month-old male ICR mice received maca powder administered by gavage for five weeks. Maca improved cognitive function, motor coordination, and endurance capacity in middle-aged mice, accompanied by increased mitochondrial respiratory function and upregulation of autophagy-related proteins in cortex. Our findings suggest that maca is a newly defined nutritional plant which can improve mitochondrial function and upregulate autophagy-related proteins and may be an effective functional food for slowing down age-related cognitive decline.