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Autophagy is a metabolic process in which cells decompose their own components through lysosomes (or vacuoles) to maintain normal physiological activities and homeostasis. Autophagy, as an evolutionarily conserved intracellular degradation pathway, is involved in many important physiological or pathological processes, such as cell homeostasis, organogenesis, neurodegeneration, tumorigenesis and migration. The research on the molecular mechanism and function of autophagy has become one of the hot biological issues.
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  • Reviews
    ZHANG Yun-Li, LI Chen, KONG Xiang-Hui
    Chinese Journal of Biochemistry and Molecular Biol. 2023, 39(6): 805-813. https://doi.org/10.13865/j.cnki.cjbmb.2022.09.1229
    Autophagy and inflammation are the important physiological reactions, especially in innate immunity. Autophagy, as a conservative metabolic process, can degrade its own disorder components through lysosomes to maintain cell homeostasis. Autophagy plays a pivotal role in degrading damaged organelles, resisting pathogenic infection and regulating inflammatory response. In the past decades, the study of autophagy in yeast and mammals has greatly increased our understanding for autophagy and its relationship with the diseases. In human, the regulation on autophagy levels can be used to prevent or treat neurodegenerative diseases, inflammatory diseases, tumors and various pathogenic microbial infections. However, in fish, the researches on autophagy and application are limited. Inflammation is a highly complex biological process, which is a natural defense response under the stimulation of ultraviolet, pathogen infection, oxidative stress and mechanical damage. Fish, as a lower vertebrate, has an incomplete acquired immune system. Innate immunity plays an important role in defensing against pathogen infection. Compared with higher vertebrate animals, although the researches on autophagy in fish cells were carried out lately, the great progress has been made in recent years on autophagy phenomenon, expression regulation of autophagy-related genes, and mechanism caused by pathogenic infection. As an important part of innate immunity, autophagy is involved in a variety of fish pathogenic infections, and fish diseases are usually accompanied by inflammatory reaction. In this review, we summarized the update findings in recent references on the autophagy and inflammatory response caused by pathogenic infection in fish, and the correlation between them, in order to deeply understand the correlation relationship between autophagy and inflammatory response in fish. This review could provide the guidance for understanding the immune mechanism of fish, and supply the foundation for developing new strategy to prevent and control fish disease.
  • Research Paper
    MENG Xiang-Fei, ZHOU Xin-Ru, HUANG Jing, CHEN Meng-Yuan, LIU Li-Juan, SHI Lu-Jia, CHEN Ci-Ai, QIAN Ling-Bo
    Chinese Journal of Biochemistry and Molecular Biol. 2023, 39(6): 840-847. https://doi.org/10.13865/j.cnki.cjbmb.2023.03.1549
    Betulinic acid (BA) exerts protective effects on organs in septic animals. However, whether BA can improve cardiac function in sepsis and the underlying mechanism remain unclear. Here, male Sprague-Dawley rats were pretreated with BA (25 mg/kg/d, i.g.) for 5 days and then intraperitoneally injected with lipopolysaccharide (LPS, 10 mg/kg). The rats were anesthetized to determine transthoracic echocardiography using a high-resolution imaging system for small animals after they were treated with LPS for 6 h. Histopathologic alterations were examined by HE staining.Myocardial injury markers (cTnI and CK-MB) and inflammatory factors (TNF-α, IL-1β and IL-6) in the serum were measured by the enzyme-linked immunosorbent assay. Autophagy-related proteins (p62 and LC3 Ⅱ) and AKT-modulated autophagy pathways in the myocardium were determined by Western blotting. Pretreatment with BA markedly improved left ventricular ejection fraction (EF) and fraction shortening (FS) (P<0.05), improved myocardial histomorphology, and significantly inhibited cTnI, CK-MB, TNF-α, IL-1β and IL-6 (P<0.05) in the septic rat serum. BA markedly decreased p62 (P<0.01), increased LC3 Ⅱ (P<0.001), and significantly down-regulated p-AKT (Thr308), p-AMPKα (Ser485/491), p-mTOR (Ser2448) and p-S6K (Thr389) (P<0.05), while markedly up-regulated p-AMPKα (Thr172) and p-ULK1 (Ser317) (P<0.01) in septic rat hearts. The findings indicate that BA can attenuate sepsis-induced myocardial dysfunctions associated with down-regulating autophagy inhibiting pathways mediated by AKT/mTOR and AKT/AMPK pathways.
  • Research Paper
    ZHANG Yuan-Yuan, ZHANG Meng, ZHU Yue, QIAN Shuai-Wei, KOU Xian-Juan
    Chinese Journal of Biochemistry and Molecular Biol. 2023, 39(4): 580-590. https://doi.org/10.13865/j.cnki.cjbmb.2023.02.1508
    Type 2 diabetes mellitus(T2DM) is a metabolic disease that causes cognitive dysfunction. The level of autophagy in the brain is associated with decreased cognitive function in T2DM. Exercise can improve T2DM cognition, but the exact mechanism remains unclear. The purpose of this study was to investigate the role of autophagy in improving cognitive dysfunction in T2DM mice with different forms of exercise intervention and its molecular mechanism. C57BL/6 male 4-week-old mice were randomly divided into control group (C), T2DM model group (DM), T2DM exercise group and T2DM autophagy inhibitor group. T2DM mice were fed with high fat diet combined with intraperitoneal injection of STZ. In the exercise group, treadmill exercise (T), climbing ladder (R) and treadmill exercise combined climbing ladder (M) were used for intervention. Chloroquine (CQ) (10mg/kg) was injected into the inhibitor group, which was divided into T2DM plus inhibitor group (DM+CQ) and DM+CQ+ treadmill intervention group (DM+T+CQ). Immunofluorescence staining showed that the three exercise interventions could decrease the number of Iba-1 positive cells and fluorescence intensity in hippocampal tissue of T2DM mice (P<0.05), and decrease NLRP3 fluorescence intensity in microglia cells (P<0.05). Western blot showed that the three exercise interventions could decrease the expression of iNOS, GFAP and Iba-1 proteins and increase the expression of Arg-1 protein in hippocampus of T2DM mice, and all the proteins show significant differences in M group (P<0.05). The three exercise interventions could reduce the expression of NLRP3 complex protein in the hippocampus of T2DM mice, and there were significant differences in M group (P<0.05) and in T group (P<0.05) except for NLRP3 protein. The three exercise interventions could decrease the protein levels of Bax and p62, and increase the protein levels of Bcl-2 and LC3 in hippocampus of T2DM mice, and there were significant differences in M group and T group (P<0.05). After addition of CQ, water maze results showed that inhibition of autophagy aggravated cognitive impairment in T2DM mice (P<0.05), and reduced the protective effect of exercise on cognition in T2DM mice. Immunofluorescence staining and Western blot showed that DM+T+CQ group had autophagy dysfunction compared with T group. Western blot results showed that compared with DM group, the expression levels of iNOS, GFAP, NLRP3, Cleaved caspase-1, Iba-1, Caspase-1 and Bax were significantly increased in DM+CQ group (P<0.05). Compared with T group, NLRP3, Cleaved caspase-1 and Bax proteins in DM+T+CQ group were significantly increased (P<0.05), and Bcl-2 protein was significantly decreased (P<0.05). In conclusion, different forms of exercise intervention can improve neuroinflammation and neuronal apoptosis in T2DM mice. Comprehensive comparison shows that treadmill exercise and treadmill combined with climbing ladder have better effects.The mechanism may be that exercise activates neuronal autophagy, reduces neuroinflammation and glial cell activation, and inhibits neuronal apoptosis.
  • Research Papers
    ZHANG Mei-Chao, MENG Yi-Ling, YING Ying-Xia, LI Dong
    Chinese Journal of Biochemistry and Molecular Biol. 2023, 39(1): 87-95. https://doi.org/10.13865/j.cnki.cjbmb.2022.11.1355
    All-trans retinoic acid (ATRA) is a targeted therapy drug for acute promyelocytic leukemia (APL) with the specific fusion gene promyelocytic leukemia (PML)-retinoic acid receptor α (RARα). In addition, ATRA also has a certain therapeutic effect in acute myeloid leukemia without PML-RARα and some other tumors. However, ATRA treatment can also cause some complications or recurrence after recovery. Therefore, it is very important to study the regulatory mechanism of ATRA-induced differentiation. Transglutaminase 2 (TGM2) is a multifunctional enzyme that regulates the mammalian target of rapamycin (mTOR) signaling pathway and autophagy. ATRA can up-regulate the expression of TGM2 in APL cells, and TGM2 knockdown inhibits ATRA-induced cell differentiation. However, its regulatory mechanism and the signaling pathways involved are still unclear. This study found that in HL60 and U937 cells, ATRA could up-regulate the expression of CD11b and TGM2 (P<0.05), inhibit the mTOR signaling pathway, and enhance autophagy. After knockdown of TGM2, the mTOR signaling pathway was enhanced and autophagy was inhibited, while ATRA-induced CD11b expression was inhibited (P<0.05). This indicates that ATRA induces myeloid differentiation in HL60 and U937 cells and induces increased expression of TGM2, and TGM2 regulates ATRA-induced myeloid differentiation through mTOR signaling pathway and autophagy. This study will help to better understand the process and mechanism of ATRA-induced leukemia cell differentiation, and deepen the understanding of the multifunctionality of TGM2, which will help to explore the drug-induced therapy for APL, other leukemias and other cancers.
  • Research Papers
    XU Wei-Dong, YANG Li, CHEN Chen, ZHOU Wei
    Chinese Journal of Biochemistry and Molecular Biol. 2022, 38(11): 1538-1546. https://doi.org/10.13865/j.cnki.cjbmb.2022.08.1107
    The biosafety of rare earth oxide nanomaterials has attracted more and more attention, and the autophagy response induced by such nanomaterials is also of great significance for cancer treatment. Autophagy plays a dual role in cell survival and death. Quercetin can promote autophagy, and rare earth oxides have been shown to induce different types of autophagy. Dextran-coated cerium oxide nanoparticles-loaded quercetin composite DCQ was synthesized, characterized, and studied for its effects on cell viability, oxidative damage, autophagy and apoptosis in human hepatoma cells HepG2. The results showed that the composite material was more toxic to HepG2 cells, and had no obvious toxic effect on normal cells, human umbilical vein endothelial cells (HUVEC). The composite material was found to induce production of reactive oxygen, block autophagy and promote apoptosis of HepG2 cells. This result shows that this nanocomposite can effectively kill human liver cancer cells, which may provide a new strategy for liver cancer treatment.
  • Reviews
    MI Hai-Chao, SHI Min, CUI Fang
    Chinese Journal of Biochemistry and Molecular Biol. 2022, 38(9): 1133-1140. https://doi.org/10.13865/j.cnki.cjbmb.2022.01.1497
    Iron, an important cofactor for heme, mitochondrial respiratory chain complexes, and various biologically important enzymes, participates in biological processes including oxygen transport, redox reactions, and metabolite synthesis. Ferritin is an iron storage protein that maintains iron homeostasis in the body by sequestering and releasing iron. Ferritinophagy is a selective type of autophagy that mediates ferritin degradation, releasing free iron when increased intracellular iron level is needed. Moderate rates of iron autophagy maintain intracellular iron content homeostasis. Excessive ferritinophagy will release a large amount of free iron, causing lipid peroxidation and cell damage via reactive oxygen species (ROS) produced by the Fenton reaction. Therefore, ferritinophagy plays a vital role in maintaining cellular iron homeostasis. Nuclear receptor co-activator 4 (NCOA4) acts as a key regulator of ferritinophagy by targeting ferritin binding and delivery to lysosomes for degradation, leading to release of free iron. Thus, NCOA4-mediated ferritinophagy is an important contributor to iron metabolism. Recent research reveals that NCOA4 is regulated by factors including iron content, autophagy, lysosomes, and hypoxia. NCOA4-mediated ferritin degradation is related to ferroptosis (an autophagic cell death process). Ferritinophagy acts as an upstream mechanism driving ferroptosis by regulating cellular iron homeostasis and ROS production, which are closely correlated with the occurrence and development of anemia, neurodegenerative diseases, cancer, ischemia/reperfusion injury, and other diseases. In this study, the functional characteristics of NCOA4-mediated ferritinophagy in ferroptosis and the role of NCOA4 in these diseases were reviewed, which may provide new avenues for the treatment of related diseases.
  • Reviews
    GUO Ling-Feng, ZHOU Chang-Lin, FAN Hong-Ye
    Chinese Journal of Biochemistry and Molecular Biol. 2022, 38(1): 8-14. https://doi.org/10.13865/j.cnki.cjbmb.2021.05.1694
    Autophagy is a lysosomal-dependent catabolic pathway that is widely present in eukaryote and involved in multiple biological functions, such as cytodifferentiation, starvation tolerance and immune defense. Specially, the autophagy process that recognizes and eliminates intracellular pathogens is defined as xenophagy, which is a vital way for immune cells to execute host defense. However, pathogens have evolved several strategies to cope with xenophagy via distinct types of virulence factors (effectors, surface proteins, etc.). Studies have shown that the autophagy regulatory signals are sophisticated, which are precisely directed by a variety of autophagy related proteins (ATG proteins). It has been proved that the key steps of autophagy undergo extensive protein post-translational modifications (PTMs), such as phosphorylation/dephosphorylation, and ubiquitination/deubiquitination, etc. These modifications endow the autophagy regulation with a high degree of dynamics and reversibility via affecting the structure, stability, activity and location of the proteins. Recently, some virulence factors were found to hijack PTMs of the ATG proteins and then affect host autophagy related pathways, thereby resisting xenophagy and promoting pathogens' survival in the host cell. This review summarizes the current knowledge of PTMs in xenophagy, especially the mechanisms that pathogens manipulate host xenophagy through PTMs, providing a guidance for exploring xenophagy intervention strategies and controlling infectious diseases.
  • Research Papers
    ZHU Wen-Ge, SONG Ge, ZHOU Qi-Shu, LI Ya-Fei, YAN Yi
    Chinese Journal of Biochemistry and Molecular Biol. 2021, 37(12): 1658-1666. https://doi.org/10.13865/j.cnki.cjbmb.2021.11.1335
    Mammalian target of rapamycin (mTOR) is one of the main modulators of cellular metabolism and plays an important role in autophagy. It has been proved that different energy states and exercise interventions can participate in the regulation of autophagy in adipose tissue, but the specific mechanism is not completely clear. In this study, in order to clarify the possible mechanism of high-fat diet and aerobic exercise regulating autophagy in white adipose tissue, male SD rats were selected as the research subjects to explore the effects of 8 weeks of moderate aerobic exercise on the expression of mTOR pathway related proteins in white adipose tissue of rats fed with high fat-diet. Thirty-two SPF male SD rats aged 3 weeks were randomly divided into standard quiet group (CS), standard exercise group (CE), high-fat quiet group (HS) and high-fat exercise group (HE) after adaptive feeding for 3 days. The rats in the high-fat group were fed with high-fat feed, and the rats in the exercise group were treated with moderate-intensity aerobic exercise intervention for 8 weeks. After the 48 h intervention ends, the body weight and body composition of each group were measured. The results showed that the average body weight was the highest in the HS group and the lowest in the CE group. The percentage of trunk fat and total body fat in HS group were significantly higher than those in CS group (P<0.05) and HE group (P<0.05). The results of Western blot showed that after 8 weeks of aerobic exercise intervention, in the high-fat feeding group, the protein expression of ULK1, p-ULK1, LC3-I, and P62 in inguinal white adipose tissue was significantly reduced (P<0.05), the protein expression of Beclin1 and p-Beclin1 were significantly increased (P<0.01); In the epididymal white adipose tissue, the protein expression of mTOR, ULK1, p-Beclin1, and P62 were significantly decreased (P<0.01), and the interaction between exercise and high-fat diet was significant (P<0.05). The results of transmission electron microscopy analysis of animal tissues showed that autophagosomes were observed in inguinal white adipose tissue and epididymal white adipose tissue of rats in CS, CE and HE groups, but autophagosomes were only observed in inguinal white adipose tissue in HS group. And the volume of autophagosomes observed in the inguinal white adipose tissue of the CS group was the largest. In summary, the results of the study showed that the 8 weeks of moderate-intensity aerobic exercise intervention has location differences in the regulation of autophagy initiation in the white adipose tissue of high-fat-fed rats. It is shown to promote the initiation of autophagy and decrease autophagosomes in the inguinal white adipose tissue, while in the epididymal white adipose tissue, it exhibits inhibition of autophagy initiation.
  • Reviews
    . 0, (): 1305-1313.
    Autophagy is a common cellular catabolism process, which is characterized by the formation of double membrane structures named autophagosome to degrade intracellular components or invading foreign substances to maintain cellular homeostasis. Abnormality of autophagy is closely related to the occurrence and development of a variety of diseases, including tumors, neurodegenerative diseases, immune diseases and so on. The investigation of autophagy regulation is a hot issue in life science and medical research. TRIM (Tripartite motif-containing proteins) family is a set of proteins with E3 ubiquitin ligase activity and usually contains three conserved domains, RING zinc finger structure, B-box structure and coiled helix domain. Many TRIM family members have been found to play important roles in autophagy regulation. This review covers the involvement of TRIMs in the regulation of autophagy process.
  • Reviews
    LI Yu-Qin , HU Jia, WANG Lin
    Chinese Journal of Biochemistry and Molecular Biol. 2021, 37(10): 1305-1313. https://doi.org/10.13865/j.cnki.cjbmb.2021.03.1583
    Autophagy is a common cellular metabolic process, which is characterized by the formation of double membrane structures named autophagosomes to degrade intracellular components or invading foreign substances to maintain cellular homeostasis. Autophagy is crucial for maintaining cell homeostasis. The dysfunction of autophagy is closely related to the occurrence and development of various diseases, including tumors, neurodegenerative diseases, viral infection, immune diseases and so on. Autophagy may be a potential therapeutic target for these diseases. Therefore, the investigation of autophagy regulation is a hot issue in life science and medical research. The TRIM (tripartite motif-containing proteins) family is a set of proteins with E3 ubiquitin ligase activity and usually contains three conserved domains, a RING zinc finger structure, a B-box structure and a coiled helix domain. Many TRIM family members have been found to play important roles in autophagy regulation, the mechanism of which include modulating autophagy-related signaling pathways, regulating autophagy core molecules and acting as autophagy receptors, etc. TRIMs participate in many biological pathways through regulating autophagy, such as immunity, virus infection and tumors. This review covers the role of TRIM proteins in regulating autophagy, the molecular mechanism and the corresponding biological effects.
  • Research Papers
    MA Ke-Xue, GUO Fang-Ying, LI Rui, SONG Ge-Ge, WU Meng, CHEN Guang-Wen, LIU De-Zeng
    Chinese Journal of Biochemistry and Molecular Biol. 2021, 37(9): 1233-1240. https://doi.org/10.13865/j.cnki.cjbmb.2021.05.1138
    Autophagy-related gene 5 (Atg5) plays an essential role in autophagy, the loss of its function impairs neurogenesis and axon regeneration. However, the biological function of Atg5 has not been characterized in planarian. Planarian is an ideal model for the study of brain regeneration. It can regenerate a new brain de novo in 1 week following amputation. To explore the role of Atg5 in planarian brain regeneration, we dissected the molecular characteristics of Atg5 in planarian Dugesia japonica (DjAtg5) and examined its function by RNAi. The full-length cDNA of DjAtg5 is 1 014 bp encoding 284 amino acids. The deduced amino sequence of DjAtg5 contains the functional Pfam domain of ATG5 and highly conserved residues for ATG5-ATG12 interaction. After amputation, the transcrips of DjAtg5 are increased and mainly distributed in the newly regenerated brain on day 3-5 of regeneration. However, knockdown of DjAtg5 by RNAi does not impair the regeneration ability and brain structure reformation, nor affects the neoblasts proliferation. Our results suggest that DjAtg5 participates in re-formation of planarian brain structure following amputation, but it is not an important regulator for planarian regeneration. However, autophagy inhibitor 3-MA can block planarian regeneration, which suggests that autophagy is necessary for planarian regeneration.
  • Research Papers
    LIU Yu-Yuan, REN Lu, HE Hong-Yun, DENG Yi-Hao
    Chinese Journal of Biochemistry and Molecular Biol. 2021, 37(7): 967-973. https://doi.org/10.13865/j.cnki.cjbmb.2021.05.1698
    In order to explore the protective mechanism of stress-activated protein kinase JNK on neurons after ischemic stroke,the model of middle cerebral artery occlusion (MCAO) in male SD rats was established by suture methods. Anisomycin (AN), a JNK agonist, was added at the characteristic time point of autophagy, and then Western blotting and immunofluorescence were used to detect the protein expression of autophagy flow pathways in ischemic penumbra, and the effects of JNK on the stability of Bcl-2-Beclin1 complex and autophagy flow pathway were analyzed.The results showed that compared with the MCAO+Veh group, the expression levels of LC3 (**P<0.01), Beclin1 (**P<0.01) and Bcl-2 (*P<0.05) atHour 12 and theANgroup were significantly increased, while the expression level of cleaved caspase-3 was significantly decreased (**P<0.01), and the expression levels of cathepsin B (***P<0.001) and Lamp1 (***P<0.001) were significantly increased; On Day2, the expression levels of cathepsin B(**P<0.01)and recombinant lysosomal associated membrane protein1(LAMP1)(*P<0.05)were significantly increased.Meanwhile, the effects of JNK activation on neurological function damage and cerebral infarction volumes of MCAO rats were analyzed by neurological injury score and TTC staining,the results showed that: compared with the MCAO+Veh group, the MCAO+AN group significantly reduced the cerebral infarction volume (Hour 12:***P<0.001,Day 2:*P<0.05) and neurological function score (Hour 12:***P<0.001,Day 2:**P<0.01).These results suggest that: in the acute stage of ischemic stroke, JNK activation promotes the dissociation of the Bcl-2-Beclin1 complex, convertsneuronal apoptosis to autophagy, and improves the survival of neurons; in the subacute stage, JNK activation inducesautophagy product accumulation, leading to autophagy injury of neurons.
  • Research Papers
    HE Li, TONG Jin
    Chinese Journal of Biochemistry and Molecular Biol. 2021, 37(6): 782-789. https://doi.org/10.13865/j.cnki.cjbmb.2021.04.1014
    Cigarette smoking is a major risk factor for chronic respiratory inflammatory diseases. Nicotine is the most important ingredient in tobacco smoke. The incidence rate of chronic respiratory diseases associated with nicotine is increasing rapidly. Therefore, it is urgent to find potential targets for nicotine-related chronic respiratory inflammatory diseases. This article hereby aims to investigate the effect of nicotine on apoptosis of BEAS-2B cells and its potential mechanism. The expressions of apoptosis, autophagy and PI3K/Akt/mTOR pathway-related proteins were detected by Western blotting. Flow cytometry and CCK-8 were used to detect cell apoptosis rate and cell viability. The results showed that nicotine induced apoptosis of BEAS-2B cells at 1, 2 and 4 mmol/L, and the cell viability decreased with the increase of concentration. Compared with the control group, the expression of autophagy-related protein LC3Ⅱ and P62 increased significantly after nicotine treatment (P<0.05). In addition, compared with the baflomycin A1 group, LC3Ⅱ of baflomycin A1 pretreatment group was not significantly altered (P>0.05). Compared with the nicotine group, rapamycin pretreatment significantly decreased cell apoptosis and increased cell activity (P<0.05). Compared with the nicotine group, the expression of p-Akt and p-mTOR decreased significantly and apoptosis decreased significantly after LY294002 pretreatment (P<0.05). Furthermore, nicotine induces apoptosis of BEAS-2B cells by inhibiting autophagy may be via PI3K/Akt/mTOR pathway, which may be a potential target for the prevention and treatment of chronic respiratory inflammatory diseases.
  • Research Papers
    HU Shi-Xiong, JIA Qiong, YANG Wan-Yun, JIAO Ding-Xing, FAN Rui-Wen
    Chinese Journal of Biochemistry and Molecular Biol. 2021, 37(5): 681-690. https://doi.org/10.13865/j.cnki.cjbmb.2021.04.1637
    Melanoma is an aggressive cancer with a poor prognosis. Understanding the molecular mechanism and diagnostic markers of melanoma is extremely important for the prevention and treatment of melanoma. LncRNAs play an important role in the genesis and progression of tumors. LncRNA-177922 was highly expressed in B16-F10 melanoma, compared with normal melanocytes. The loss of mitogen-activated protein kinase 15 (MAPK15) affects tumor initiation and progression. Here, LncRNA-177922 was overexpressed in B16-F10 cells, and the results showed that the mRNA and protein of related-genes to melanogenesis, proliferation, and migration were significantly up-regulated (P<0.05), the mRNA levels and protein abundance of autophagy-related genes were down-regulated (P<0.05), and the PI3K/AKT/mTOR pathway was activated. Also, the phenotypes of cell proliferation, migration, and autophagy were further verified. The results suggested that LncRNA-177922 targeted MAPK15 in regulating the biological processes of B16-F10 cells such as melanogenesis, proliferation, migration, and autophagy through the cross-point extracellular regulated protein kinases (ERK), which might provide potential new therapeutic targets and diagnostic markers.
  • Reviews
    ZHENG Pei-Pei, XIAO Jian WU Yan-Qing
    Chinese Journal of Biochemistry and Molecular Biol. 2021, 37(5): 588-594. https://doi.org/10.13865/j.cnki.cjbmb.2020.11.1395
    Diabetes, a metabolic disease characterized by hyperglycemia, can cause central nerve system damage, lead to alteration of the neuronal structure and function, and consequently induce cognitive dysfunction. Recently, diabetes-associated cognitive dysfunction (DACD) and its molecular mechanism have become a research frontier. The phospoinositide 3 kinase/protein kinase B/Forkhead box O (PI3K/PKB/FOXO) signaling pathway is an important upstream regulatory mechanism for autophagy. Here we review the role of the PI3K/AKT/FOXO signaling pathway in the regulation of Gs, Bnip3 and Spk2 gene expressions. GS regulates the Gln-mTORC1 pathway and thus activates autophagy; BNIP3 enhances LC3 expression and promotes autophagy. Moreover, the AMPK-FOXO3a-mTORC1 signaling pathway is also an important pathway that involved in the regulation of autophagy. These studies suggest that FOXO3a may be a key target for the treatment of DACD. This review aims to provide a theoretical basis and molecular target for the clinical treatment of DACD and it related drug development.
  • Reviews
    XIE Fo-Tian, WANG Dong-Mei, LV Yi
    Chinese Journal of Biochemistry and Molecular Biol. 2020, 36(10): 1151-1158. https://doi.org/10.13865/j.cnki.cjbmb.2020.08.1173

    Alcoholic liver disease (ALD) is a chronic liver injury caused by long-term heavy drinking and its pathogenesis is extremely complex. It is believed that ethanol metabolism and the production of some related metabolites, such as acetaldehyde and reactive oxygen species, are the important causes of hepatotoxicity. Oxidative stress, inflammation, mitochondrial damage and lipid metabolism disorders caused by these substances are crucial factors that cause ALD. Oxidative stress, inflammatory response, mitochondrial injury and lipid metabolism disorder caused by these substances are important factors causing liver injury. So far, there is still a lack of effective therapeutic drugs for ALD. Therefore, it is an urgent problem to further understand the mechanism of the occurrence and development of ALD and to develop effective targeted drugs for related molecules. Autophagy is a lysosomal degradation process that is conservatively evolved in eukaryotes. It promotes cellular metabolism and maintains the homeostasis of the environment by removing detrimental organelles and macromolecular substances. Numerous researches have disclosed that ethanol can disturb the process of autophagy in a variety of ways to exacerbate alcoholic liver injury. However, autophagy plays a vital regulatory role in the development and progress of ALD, including removing excessive lipid droplets, damaged mitochondria and accumulated protein polymers from hepatocytes. Therefore, activation of autophagy may alleviate ALD to a certain extent. Although there have been many investigations on autophagy and its relationship with ALD, many key issues remain to be resolved. This article reviewed the research progress on autophagy and its participation in ALD regulation. At the same time, it also compared and analyzed the effects and potential causes of different ALD modeling methods on autophagy. Finally, we preliminarily discussed the prevention and treatment strategies of ALD based on autophagic regulation, which may provide new ideas for the treatment of this disease.

  • Reviews
    XIA Jie, XU Bo
    Chinese Journal of Biochemistry and Molecular Biol. 2020, 36(7): 748-755. https://doi.org/10.13865/j.cnki.cjbmb.2020.02.1502

    Autophagy is an essential degradation pathway in clearing abnormal protein aggregates from mammalian cells and is responsible for protein homeostasis and neuronal health. Several studies have shown that autophagy deficits occurred in the brain of Alzheimer’s disease (AD). Defects in autophagy affect the metabolism of β-amyloid (Aβ), assembling of Tau, and synaptic plasticity, contributing to the progress of AD. Recently, increasing evidence suggests that aerobic exercise could regulate autophagy, and ameliorate the pathological features of AD animals, but the molecular mechanisms are still unknown. In this review, we summarized the latest progress supporting the role of exercise regulated autophagy in the prevention and treatment of Alzheimer’s disease. Firstly, exercise induces autophagy by activating AMPK and inhibiting mTOR signaling. Exercise enhances autophagy flux and autolysosome degradation, which accelerates the removal of Aβ and phosphorylated Tau. Secondly, Exercise increases the amount of BDNF in the brain, which suppresses autophagy flux via the BDNF/TrkB signaling and the PI3K/Akt pathway, thereby promoting synaptic plasticity and memory through a BDNF-regulated mechanism. In addition, exercise may also maintain neurotransmitter homeostasis by regulating autophagy.

  • LIU Gui-Hong,ZHANG Zhi-Hui
    Chinese Journal of Biochemistry and Molecular Biol. 2020, 36(5): 552-558. https://doi.org/10.13865/j.cnki.cjbmb.2020.02.1389
    Resveratrol inhibits the proliferation and induces apoptosis of human renal carcinoma 786-O cells. However, the effect and mechanism of resveratrol on autophagy in 786-O cells remain unclear. To explore its mechanism, 786-O cells were cultured in vitro. First, CCK-8 assay results showed that resveratrol inhibited cell viability in a dose- and time-dependent manner. Secondly, TUNEL staining revealed that resveratrol treatment induces apoptosis. Thirdly, we measured autophagy levels using a combination of transmission electron microscopy, acridine orange staining as well as GFP-LC3 plasmid transfection analysis. And the autophagy levels in the resveratrol group increased significantly compared with the control group. Lastly, we directly measured the expressions of LC3, Beclin1, PI3K, p-PI3K, Akt, p-Akt, mTOR and p-mTOR by Western blotting, and found that LC3-II/LC3-I and Beclin-1 in the resveratrol group were significantly higher than those in the control group (P<0.01), while p-PI3K/PI3K, p-Akt/Akt and p-mTOR/mTOR were reduced (P<0.01). indicating that resveratrol caused accumulation of autophagosomes in 786-O cells. In conclusion,we propose that resveratrol induces autophagy in 786-O cells by inactivating the PI3K/Akt/mTOR signaling pathway.
  • ZANG Rui, YANG Ji-Ping, GUO Tao, CHU Xin, ZHANG Xue-Yu, WU Yu-Ming, DENG Yi-Hao
    Chinese Journal of Biochemistry and Molecular Biol. 2020, 36(5): 544-551. https://doi.org/10.13865/j.cnki.cjbmb.2020.03.1473

    Schisandra A (Sch A) is a bioactive lignan compound in Schisandra, whose neuroprotective effect has been demonstrated in animal models of various neurological diseases. However, there is still no systematic study showing whether Sch A produces neuroprotective effects on the cerebral ischemia reperfusion rat model by affecting neuronal autophagy activity in the ischemic penumbra of the rat brain. Therefore we investigated the efficacy of schisandra A (Sch A) on neural injury and autophagic activity of neurons in ischemic penumbra of rats with cerebral stroke. 90 Male Sprague-Dawley rates were randomly divided into five groups: the Sham group, the middle cerebral artery occlusion (MCAO) model group, the Sch A low-dose group (40 μg/kg), the Sch A medium-dose group (80 μg/kg) and the Sch A high-dose group (160 μg/kg). The rat model (MCAO) was prepared according to the modified ZeaLonga method. The cerebral ischemia was persistent for 90 min and then prepared for reperfusion. The Sch A was administrated by lateral ventricle immediately after onset of reperfusion once daily for seven days. Six rats in each group were randomly selected to perform neurological score, the infarction volume was then measured by TTC staining assays. The brain tissues in the penumbra from six rats in each group were gained to detect the expressions of autophagy-related protein of Beclin1 and LC3-Ⅱ by western blotting in ischemic penumbra. The brain tissues from the rest six rats were collected to detect the LC3 expression and its cellular localization by immunofluorescence, and the result was represented by percentage of LC3-NeuN-positive cells. The results showed that the infarct volume and neurological score in the MCAO group were significantly higher than those in the sham group. Meanwhile, the expression levels of LC3-Ⅱ and Beclin1 were markedly promoted. The infarct volume in each Sch A administration group was dramatically attenuated, compared with that in the non-administration group. Furthermore, the neurofunctional deficit was significantly alleviated, with the expression levels of LC3 and Beclin1 in the Sch A administration group prominently promoted. Moreover, the double immunofluorescence assays demonstrated that Sch A changed autophagic activity mainly in neurons. The results above indicate that Sch A is able to significantly attenuate cerebral ischemia/reperfusion injury in rats, and this neuroprotective efficacy is closely associated with promotion of autophagic activity at the ischemic penumbra.

  • Research Papers
    LIU Jia, QU Chao, HAN Chao, LI Hong-Yan, ZHANG Ye-Jun, AN Li-Jia, ZOU Wei
    Chinese Journal of Biochemistry and Molecular Biol. 2020, 36(4): 448-456. https://doi.org/10.13865/j.cnki.cjbmb.2020.02.1374
    Glioma is a primary intracranial malignant tumor with a 5-year survival rate of less than 1%. At present, there is no effective treatment except for surgical resection. In recent years, it has been found that glioma may be related to the abnormal expression of various potassium ion channels. Autophagy is a physiological process that membranes encapsulate part of the cytoplasm, proteins and organelles which need to be degraded. Inducing autophagy and promoting apoptosis of glioma cell is a new strategy for tumor therapy. Our previous studies found that Kv1.5 is involved in Cav-1-mediated proliferation and apoptosis of multiple tumor cells. But it is not clear that whether Kv1.5 is involved in autophagy of glioma cells. In this paper, we first used different blockers (TEA, 4-AP and DPO-1) to observe the effect on cell survival in human glioma cell line U251. And found that DPO-1 has two-way effect on cell survival rate: low concentration of DPO-1 promotes but high concentration inhibits survival of U251 glioma cells. Treatment of 1 mmol/L DPO-1 for 6 h can promote the expression of LC3 and inhibit the phosphorylation of mTOR, suggesting that Kv1.5 channel may be in autophagy of glioma cells. Secondly, we knocked down and overexpressed the protein of Kv1.5 channel using transient transfection, respectively. It is found that knock down of Kv1.5 channel protein promoted autophagy, activated ERK pathway while overexpression of Kv1.5 inhibited autophagy. Furthermore, flow cytometry was used to detect apoptosis rates, and data found that changing the expression level of Kv1.5 channel protein can induce early apoptosis. These results suggested that the Kv1.5 channel is involved in the autophagy of human glioma cells. This study provides theoretical and experimental evidence for targeted therapy of glioma with specific Kv channel blockers.