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This study aimed to explore the effects of galangin on energy metabolism and autophagy in gastric cancer MGC803 cells and the underlying mechanism. Cell counting kit-8(CCK-8) was used to detect the effects of galangin at different concentrations on via-bility of MGC803 cells after 48 h intervention. Western blot was carried out to measure the effects of galangin on expression of proteins related to autophagy, nuclear factor-κB(NF-κB) pathway and energy metabolism, followed by the determination of its effects on mRNA expression of energy metabolism-related proteins by Real-time quantitative PCR(qPCR). The impact of galangin on autophagy was explored using AutophagyGreen dye reagent, with autophagosomes and lysosomes observed under the transmission electron microscope(TEM). Nude mice transplanted with gastric cancer MGC803 cells via subcutaneous injection were randomly divided into the following three groups: control(0.5% sodium carboxymethyl cellulose, once a day), 5-fluorouracil(5-FU, 50 mg·kg~(-1), twice a week), and galangin(120 mg·kg~(-1), once a day) groups. The body weight and tumor volume were measured once every three days with a vernier caliper at the same time point by the same person. After 21-d treatment, the tumor tissue was isolated and weighed for the calculation of the tumor-suppressing rate. The comparison with the control group revealed that galangin inhibited the viability of MGC803 cells, up-regulated the protein expression of microtuble-associated protein 1 light chain 3 B(LC3 B) Ⅱ, inhibited the phosphorylation of NF-κB pathway-related proteins, and promoted the formation of autophagosomes in MGC803 cells. However, it did not obviously affect the expression of energy metabolism-related proteins. Furthermore, galangin at 120 mg·kg~(-1) significantly reduced the tumor weight and volume in mice, enhanced LC3 BⅡ protein expression, and inhibited the phosphorylation of NF-κB pathway-related proteins. All these have suggested that galangin inhibited the growth of gastric cancer MGC803 cells both in vivo and in vitro, possibly by inhibiting the NF-κB pathway and enhancing autophagy.
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Animals , Mice , Autophagy , Flavonoids , Mice, Nude , NF-kappa B/genetics , Signal Transduction , Stomach Neoplasms/geneticsABSTRACT
Objective: To explore the underlying mechanism of Buyang Huanwu Decoction extracts on apoptosis and autophagy in PC12 cells model with oxidative stress injury. Methods: Different level oxidative stress injury models with H2O2 at various concentrations were established. The effective concentrations of Buyang Huanwu Decoction extracts were determined by MTT method in the initial stage and the intensifying period after oxidative stress injury. The apoptosis of PC12 cells were evaluated by FCM and TUNNEL, the autophagy situations were observed by TEM and mRFP-GFP-LC3. Furthermore, the proteins of Bax, Bcl-2, Beclin1, LC3A, and LC3B related to apoptosis were determined by Western blotting. Results: The initial stage and the intensifying period of oxidative stress injury cell models were established by H2O2 at the concentration of 1.5 and 2.0 mmol/L, respectively. Compared with the control group, model group appeared increasing apoptosis and autophagy levels, and model group had higher expressions of Bax/Bcl-2, Beclin1, LC3B and lower expression of LC3A (P < 0.05). Compared with the initial stage of oxidative stress injury cell models, Buyang Huanwu Decoction extracts could reduce the Bax/Bcl-2 and restrain apoptosis rates, while the autophagy was activated by up-regulation Beclin1 and LC3B/LC3A (P < 0.05). When the serious apoptosis and excessive autophagy were observed in the intensifying period of oxidative stress injury cells, the extracts could play the protective effect by apoptosis restraining and autophagy alleviating. Conclusion: Buyang Huanwu Decoction extracts can play the protective effects on oxidative stress injury cell models in different period by regulating apoptosis and autophagy.
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Objective@#To observe changes in expression of autophagy proteins in peripheral CD4+ T lymphocytes and the epidermis of skin lesions, as well as generation of autophagy vesicles in epidermal cells in skin lesions of patients with herpes zoster, and to explore the relationship between varicella-herpes zoster virus (VZV) infection and autophagy.@*Methods@#Totally, 35 patients with herpes zoster were enrolled from Department of Dermatology, General Hospital of Southern Theater Command of PLA between December 2017 and December 2018, including 20 males and 15 females. Their age ranged from 18 to 79 (59.23 ± 9.27) years, pain duration was 5.14 ± 2.28 days, and lesion duration (from the onset of the lesion to the clinic visit) was 3.45 ± 1.77 days. Flow cytometry was performed to determine the expression of autophagy proteins including microtubule-associated protein 1 light chain 3B (LC3B) , Beclin-1 and p62 in peripheral blood CD4+ T lymphocytes of these patients. Thirty healthy adults served as control group. Lesional skin tissues were obtained from 12 patients with herpes zoster, and perilesional normal skin tissues of the same patient served as the control. Immunohistochemical study was conducted to determine the expression of autophagy proteins LC3B, Beclin-1 and p62 in epidermal tissues, and transmission electron microscopy to observe the generation of autophagy vesicles in epidermal cells. Two independent-sample t-test was carried out for intergroup comparison.@*Results@#The expression rates of autophagy proteins LC3B and Beclin-1 in peripheral CD4+ T lymphocytes were significantly higher in the herpes zoster group (61.23% ± 7.61%, 35.84% ± 4.22%, respectively) than in the control group (36.56% ± 4.27%, 15.34% ± 1.89%, respectively; t = 15.75, 24.56 respectively, both P < 0.01) , while the expression rate of p62 (5.75% ± 0.67%) was significantly lower in the herpes zoster group than in the control group (10.03% ± 1.15%, t = 18.65, P < 0.01) . Among the 12 patients with herpes zoster, the expression levels of LC3B and Beclin-1 in the epidermis were significantly higher in the skin lesions than in the perilesional normal skin tissues (t = 2.86, 4.58, P < 0.05) , but the expression level of p62 was significantly lower in the skin lesions than in the perilesional normal skin tissues (t = 2.43, P < 0.05) . Transmission electron microscopy showed formation of autophagy vesicles containing virus particles in epidermal cells in the skin lesions of 12 patients with herpes zoster, and vesicle counts were significantly higher in the skin lesions than in perilesional normal skin tissues (t = 9.67, P < 0.01) .@*Conclusion@#The autophagy level was elevated in peripheral CD4+ T lymphocytes and epidermis of skin lesions of patients with herpes zoster.
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Objective To observe changes in expression of autophagy proteins in peripheral CD4+ T lymphocytes and the epidermis of skin lesions,as well as generation of autophagy vesicles in epidermal cells in skin lesions of patients with herpes zoster,and to explore the relationship between varicella-herpes zoster virus (VZV) infection and autophagy.Methods Totally,35 patients with herpes zoster were enrolled from Department of Dermatology,General Hospital of Southern Theater Command of PLA between December 2017 and December 2018,including 20 males and 15 females.Their age ranged from 18 to 79 (59.23 ± 9.27) years,pain duration was 5.14 ± 2.28 days,and lesion duration (from the onset of the lesion to the clinic visit) was 3.45 ± 1.77 days.Flow cytometry was performed to determine the expression of autophagy proteins including microtubule-associated protein 1 light chain 3B (LC3B),Beclin-1 and p62 in peripheral blood CD4 + T lymphocytes of these patients.Thirty healthy adults served as control group.Lesional skin tissues were obtained from 12 patients with herpes zoster,and perilesional normal skin tissues of the same patient served as the control.Immunohistochemical study was conducted to determine the expression of autophagy proteins LC3B,Beclin-1 and p62 in epidermal tissues,and transmission electron microscopy to observe the generation of autophagy vesicles in epidermal cells.Two independent-sample t-test was carried out for intergroup comparison.Results The expression rates of autophagy proteins LC3B and Beclin-1 in peripheral CD4 + T lymphocytes were significantly higher in the herpes zoster group (61.23％ ± 7.61％,35.84％ ± 4.22％,respectively) than in the control group (36.56％ ± 4.27％,15.34％ ± 1.89％,respectively;t =15.75,24.56 respectively,both P ＜ 0.01),while the expression rate of p62 (5.75％ ± 0.67％) was significantly lower in the herpes zoster group than in the control group (10.03％ ± 1.15％,t =18.65,P ＜ 0.01).Among the 12 patients with herpes zoster,the expression levels of LC3B and Beclin-1 in the epidermis were significantly higher in the skin lesions than in the perilesional normal skin tissues (t =2.86,4.58,P ＜ 0.05),but the expression level of p62 was significantly lower in the skin lesions than in the perilesional normal skin tissues (t =2.43,P ＜ 0.05).Transmission electron microscopy showed formation of autophagy vesicles containing virus particles in epidermal cells in the skin lesions of 12 patients with herpes zoster,and vesicle counts were significantly higher in the skin lesions than in perilesional normal skin tissues (t =9.67,P ＜ 0.01).Conclusion The autophagy level was elevated in peripheral CD4+ T lymphocytes and epidermis of skin lesions of patients with herpes zoster.
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Objective::To study the effect of Qiyu Sanlong decoction on the growth of subcutaneous tumor in lung cancer mice and the expressions of key autophagy molecule, yeast Atg6 homologous (Beclin1), autophagy related genes5 (Atg5), and microtubule-associated protein1 light chain3 (LC3B). Method::Lewis lung carcinoma cells (LLC) were used to reproduce the lung cancer mice transplanted model. After the modeling, the mice were randomly divided into model group, Qiyu Sanlong decoction group, chemotherapy group and combination group, with 18 transplanted mice in each group. In model group, mice were fed with 0.9% saline 20 mL·kg-1 daily. In Qiyu Sanlong decoction group, mice were fed with Qiyu Sanlong decoction 80.48 g·kg-1 daily. The chemotherapy group was intraperitoneally injected with 0.4 mL cisplatin solution (DDP) at the 1st, 3rd and 5th day. The combination group was orally given the drugs at the concentration of 80.48 g·kg-1, and 0.4 mL DDP solution was intraperitoneally injected at the 1st, 3rd and 5th day. After 21 days of continuous treatment, tumor tissue was exfoliated and weighed, and the tumor inhibition rate was calculated. Hematoxylin-eosin (HE) staining was used to observe the histological changes of tumor. The expressions and localizations of Beclin1 and LC3B in tumor tissues were detected by immunohistochemical staining. Protein expressions of Beclin1, Atg5, LC3B-Ⅰand LC3B-Ⅱ were determined by Western blot, and the ratio of LC3B-Ⅱ/LC3B-Ⅰ was calculated. The transcription levels of Beclin1, Atg5 mRNA in tumor tissues were detected by Real-time PCR. Result::Qiyu Sanlong decoction had a mild inhibitory effect on transplanted tumor, with an inhibitory rate of 31.2%. Under microscope, patchy necrotic tumor cells were observed in the tumor tissues of Qiyu Sanlong decoction group. Immunohistochemical staining and Western blot analysis showed that Qiyu Sanlong decoction could up-regulate the expressions of Beclin1, Atg5 and LC3B protein (P<0.01), and promote the conversion from LC3B-Ⅰ into LC3-Ⅱ compared with the model group. Real-time PCR results showed that Qiyu Sanlong decoction could promote the transcription of Beclin1 mRNA and Atg5 mRNA compared with the model group (P<0.01). Conclusion::Qiyu Sanlong decoction has a mild inhibitory effect on lung tumors, and its mechanism may be related to up-regulating the expressions of autophagy key proteins Beclin1, Atg5 and LC3B, and promoting the conversion from LC3B-Ⅰ to LC3B-Ⅱ.
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Objective:To investigate the effect of Danggui Yinzi on allergic reaction in chronic urticaria (CU) mice model and the mechanism of autophagy intervention. Method:The SPF BALB/c mice were used to replicate the CU mice model by intraperitoneal injection of ovalbumin and aluminum hydroxide suspension. The animals were randomly allocated into six groups: a normal group (normal saline 20 mL·kg-1·d-1), a model group (normal saline 20 mL·kg-1·d-1), a loratadine group(0.001 3 g·kg-1·d-1), a Danggui Yinzi high，medium and low-dose group（39.3，19.6，9.8 g·kg-1·d-1）. The pathological changes of skin tissues were observed by hematoxylin-eosin (HE) staining. Morphological changes of autophagy in skin tissues epithelial cells were observed by transmission electron microscope. The mRNA levels of microtubule-associated protein 1 light chain 3B(LC3B) and ubiquitin-binding protein p62 mRNA in skin tissues were detected by real-time quantitative polymerase chain reaction (Real-time PCR). The expressions of LC3B and p62 in skin tissues were detected by immunohistochemistry (IHC). Result:Danggui Yinzi can significantly improve the pathological manifestations of dermal edema, collagen bundles separation, telangiectasia in CU mice， it can also improve autophagosomes formation and abnormal cell ultrastructure such as nuclear chromatin condensation, mitochondrial swelling, endoplasmic reticulum expansion, etc. Compared with the normal group, the protein expressions of LC3B in skin tissues of the model group was significantly increased (P<0.01), LC3B mRNA level was increased too, while p62 mRNA levels and its protein expressions were decreased-regulated (P<0.01). Compared with the model group, levels of LC3B mRNA and protein expressions of the Danggui Yinzi groups were significantly increased (P<0.05,P<0.01), while p62 mRNA levels and its protein expressions were significantly decreased-regulated (P<0.05,P<0.01). Conclusion:Danggui Yinzi can regulate the expression of LC3B, p62 mRNA and protein expressions, enhance the level of autophagy, and improve the pathological state of CU mice.
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@#Introduction: Autophagy is a mechanism that degrades large damaged organelles and misfolded proteins to maintain the homeostasis in all cells. It plays double-faceted roles in tumourigenesis and prevention of various cancers. In our side observation of investigating the prognostic value of autophagy in colorectal cancer (CRC), we found high expression of autophagy proteins (LC3A, LC3B, and p62/SQSTM1) in the colonic ganglion cells. To our best understanding, this is the first paper reporting such finding. Materials and Methods: Formalin-fixed paraffin-embedded (FFPE) CRC tissues blocks were retrieved and confirmed by haematoxylin & eosin (H&E) staining. Immunohistochemistry (IHC) targeting autophagy proteins (LC3A, LC3B, and p62/SQSTM1) was then performed followed by pathological examination. Results: All three autophagy proteins were present in both normal and tumour tissues of CRC patients. Interestingly, high expression of autophagy proteins in colonic ganglion cells was consistently seen regardless of tissue type (normal or cancer) or tumour site (caecum, ascending, transverse, descending, sigmoid colon and rectum). Conclusions: This work highlights the high autophagic activities in human colonic ganglion cells.
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Objective To investigate the role of autophagy in the development of diabetic cataract by detecting the expression of autophagy-related factors (BECN1,LC3B,P62) in diabetic mouse lens epithelial cells.Methods Eighty C57BL/6 male mice were selected.Fifty C57 mice were consecutively dosed with streptozotocin (STZ) 50 mg/ (kg · d) by intraperitoneal injection to induce type 1 diabetes mellitus model,and served as the model group;the remaining 30 mice were injected with appropriate dose of citrate buffer,and served as the control group.The fasting plasma glucose was tested by collecting the caudal vein blood in the model group.The morphological changes of autophagy of lens epithelial cells were observed by transmission electron microscopy.The expression and localization of LC3B and P62 protein were detected by immunohistochemistry.PCR was used to detect the expression of BECN1,LC3B and P62 mRNA in the anterior capsule.The relative expression of autophagy-related proteins in the anterior capsule was detected by Western blot.The use of animals complied with Regulations on the Management of Experimental Ainimals from Shandong Eye Institute.Results Compared with the control group,transmission electron microscopy revealed that the autophagosomes of lens epithelial cells in model group was large and contained more mitochondria.Immunohistochemical method showed that the expression of LC3B and P62 proteins in the anterior capsule tissue of experiment group was stronger than that of the control group.The relative expression level of BECN1,LC3B and P62 mRNA in the experiment group was 1.48±0.10,2.62±0.15 and 1.89±0.20,respectively,which was higher than 1.10±0.02,1.10±0.05 and 1.01±0.01 in the control group,with significant differences between the two groups (t =6.64,14.25,6.14;all at P ＜ 0.05).The relative expression of BECN1,LC3B and P62 protein in the experiment group was 1.50±0.10,1.24±0.09 and 3.19± 1.04,respectively,which was higher than 1.00±0.00,1.00±0.00 and 1.00±0.00 in the control group,with significant differences between the two groups (t =8.75,6.10,3.65;all at P＜0.05).Conclusions The phenomenon of autophagy in lens epithelial cells of diabetic mice is abnormal,and autophagy dysfunction may play an important role in the formation of diabetic cataract.
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Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun14 domain-containing protein 1 (FUNDC1) was reported to be a new receptor for hypoxia-induced mitophagy in mammalian cells and interact with microtubule-associated protein light chain 3 beta (LC3B) through its LC3 interaction region (LIR). Moreover, the phosphorylation modification of FUNDC1 affects its binding affinity for LC3B and regulates selective mitophagy. However, the structural basis of this regulation mechanism remains unclear. Here, we present the crystal structure of LC3B in complex with a FUNDC1 LIR peptide phosphorylated at Ser17 (pS), demonstrating the key residues of LC3B for the specific recognition of the phosphorylated or dephosphorylated FUNDC1. Intriguingly, the side chain of LC3B Lys49 shifts remarkably and forms a hydrogen bond and electrostatic interaction with the phosphate group of FUNDC1 pS. Alternatively, phosphorylated Tyr18 (pY) and Ser13 (pS) in FUNDC1 significantly obstruct their interaction with the hydrophobic pocket and Arg10 of LC3B, respectively. Structural observations are further validated by mutation and isothermal titration calorimetry (ITC) assays. Therefore, our structural and biochemical results reveal a working model for the specific recognition of FUNDC1 by LC3B and imply that the reversible phosphorylation modification of mitophagy receptors may be a switch for selective mitophagy.
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Crystallography, X-Ray , Membrane Proteins , Chemistry , Metabolism , Microtubule-Associated Proteins , Chemistry , Metabolism , Mitophagy , Mitochondrial Proteins , Chemistry , Metabolism , Peptides , Chemistry , Metabolism , Phosphorylation , Protein Structure, QuaternaryABSTRACT
Objective To investigate the effect and mechanism of high-dose sirolimus (rapamycin) upon protecting the hepatic ischemia-reperfusion injury (HIRI) in aged mice. Methods Twenty C57BL/6 aged mice were randomly and evenly divided into the ischemia-reperfusion injury group (IRI group), low-dose rapamycin pretreatment group (rpm group), high-dose rapamycin pretreatment group (RPM group) and control group (Sham group) using the random number table method (5 mice in each group). In the Sham group, abdominal cavity was incised and sutured alone. In the other three groups, aged mouse 70% HIRI models were established. The ischemia time was 60 min. At preoperative 1 h, rapamycin at a dose of 1 mg/kg and 5 mg/kg was administered via intraperitoneal injection in the rpm and RPM groups. At 12 h post-reperfusion, hematoxylin-eosin (HE) staining was performed to observe the histological changes in the mouse liver. Suzuki grading method was adopted to evaluate the pathological score. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), tumor necrosis factor (TNF)-α and interleukin (IL)-10 and the LC3B-Ⅱ protein level in the liver tissues were quantitatively measured and statistically compared among different groups. Results HE staining of the liver tissues revealed normal liver tissues in the Sham group, severe liver cellular injury accompanied with a large quantity of inflammatory cellular infiltration in the IRI and rpm groups. Mild sinusoidal congestion and slight inflammatory cellular infiltration were observed in the RPM group. The pathological score was 5 (4-6) in the RPM group, significantly lower than 7 (5-8) and 8 (7-10) in the rpm and IRI groups (Z=-2.554 and -2.731, both P<0.05). In terms of postoperative liver function parameters, the AST level was (691±207) U/L in the RPM group, significantly lower compared with (2032±575) U/L and (1817±777) U/L in the IRI and rpm groups (t=4.90 and 3.13, both P<0.05). In the RPM group, the ALT level was measured as (996±584) U/L, considerably lower than (2992±992) U/L and (2373±687) U/L in the IRI and rpm groups (t=3.86 and 3.41, both P<0.05). The AST and ALT levels did not significantly differ between the IRI and rpm groups (both P>0.05). No statistical significance was identified in the TNF-α and IL-10 levels among different groups (all P>0.05). Western blot analysis revealed that the relative expression level of LC3B-Ⅱ protein in the liver tissue of the RPM group was significantly higher than those in the Sham, IRI and rpm groups (all P<0.05). Conclusions Administration of high-dose rapamycin exerts a protective effect upon HIRI probably through promoting cellular autophagy in aged mice.
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Objective To investigate the effect of autophagy on the proliferation and migration of cervi-cal cancer cells ,as well as the underlining mechanisms .Methods Rapamycin was used to induce the autophagy in HeLa cells,formation of autophagosomes was observed by staining with acridine orange under fluorescence mi -croscope.Western blot was used to detect the expression of LC 3 and PI3K/Akt/mTOR in HeLa cells.The LC3 plasmid was transfected into HeLa cells .The distribution of LC3 in cells and the expression of LC3 was identified by fluorescence microscope and Western blot ,respectively.The autophagy was inhibited with 3-methyladenine(3-MA )in HeLa cells.The cell proliferation was monitored by RTCA real -time instrument.Transwell chamber was carried out to assess cell migration .Results After 6h of rapamycin treatment ,the expression of LC3B was in-creased in HeLa cells ( P<0 .05 ) .The proliferative and migration ability were weakened compared to wild type HeLa cells(P<0.05).The same results in the presence of 3-MA.The expression of PI3K/AKT/mTOR path-way proteins were activated by rapamycin treatment and LC 3 overexpression(P<0.05).Conclusion Autophagy can suppress the proliferation and migration in cervical cancer cells ,which may relate to PI3K/Akt/mTOR path-way.
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Objective To construct the prokaryotic expression vector of human autophagy-related LC3B gene,obtain the GST-LC3B recombinant plasmid , purify the GST-LC3B fusion protein and identify its activity in vitro.Methods Human LC3B coding region was amplified from the human mammary gland cDNA by PCR and inserted into the prokaryotic expres -sion vector pGEX-KG.The recombinant plasmid pGEX-KG-LC3B was transformed into E.coli Rossate.The expressed product was purified by GST-Sepharose 4B beads and identified by SDS-PAGE and Western blot analysis .The function of the purified protein GST-LC3B was detected by GST pull-down assay.Results About 400 bp of the LC3B coding region was successfully amplified from the mammary gland library by PCR and inserted into pGEX -KG.The result of double diges-tion and sequencing showed that the GST-LC3B recombinant plasmid was successfully obtained .The GST-LC3B fusion pro-tein of about 40 000 (Mr) was successfully purified and identified by SDS-PAGE and Western blotting analysis.GST pull-down assay showed that GST-LC3B could interact with Atg4B, which identified its known function .Conclusion The pro-karyotic expression vector of GST-LC3B is constructed successfully , which will facilitate further research on the function of LC3B in autophagy.
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Purpose To investigate the expression of autophagy-related protein LC3B in cervical squamous carcinoma and its relation-ship with Ki-67 expression. Methods To detect the expression of LC3B in 16 cases of normal cervical tissues and 126 cases of squa-mous cell carcinoma by immunohistochemical staining. In addition, Ki-67 protein was also detected in 126 cases of squamous cell car-cinoma in the same assay. The relationship between LC3B expression and Ki-67 in cervical squamous cell cancer was statistical analy-sis. Results Expression level of LC3B were significantly lower in cervical squamous carcinoma than normal squamous epithelial cells (P<0. 05), and the expression of LC3B was negatively correlated with Ki-67(rs = -0. 248, P<0. 05). Conclusion It appears that decreased levels of autophagy which indicated by low expression of LC3B may promote cancer cell proliferation in the early stages of cervical squamous cell carcinoma, which provides a clinical referential evidence for further explore the mechanism of autophagy in cer-vical cancer development.