Age-related macular degeneration is one of the major causes of blindness in the elderly. As an important pathway of cell metabolism, autophagy maintains intracellular homeostasis through the degradation and recycle of damaged organelles and macromolecules. Understanding its mechanism may promote discoveries to delay aging process, reduce the incidence of age-related diseases. In mammals, silent information regulator protein 6 (SIRT6) plays its deacetylase and ribonucleotransferase activity in multiple signaling pathways, including inhibition of cellular senescence, tumorigenesis, metabolic diseases, regulating cellular lifespan. It has a significant impact on the structure and function of tissues and organs. SIRT6 regulates intracellular autophagy mainly through the insulin-like growth factor-protein kinase B-mammalian target of rapamycin, reducing the accumulation of toxic metabolites and cellular senescence. The function of SIRT6 in age-related macular degeneration need to be combined with the genetic background, pathogenesis, clinical manifestations and other aspects of the disease, and it is expected to be further studied in subsequent studies.
Objective To study the effect and mechanism of Xuebijing injection on sepsis-induced acute lung injury (ALI) in mice by regulating autophagy. Methods A total of 80 BALB/c male mice were randomly divided into control group, model group, Xuebijing group and Xuebijing+3-methyladenosine (3-MA) group, with 20 mice in each group. The control group received sham operation, while sepsis-induced ALI model was established in the later three groups by cecal ligation and puncture, on that basis, the Xuebijing group was given 10 mL/kg Xuebijing by intraperitoneal injection and the Xuebijing+3-MA group was given 10 mL/kg Xuebijing and 10 mg/kg autophagy inhibitor 3-mA by intraperitoneal injection. The cumulative survival rates of the four groups were observed 72 h after modeling, and the pathological changes of lung tissues, lung wet weight /dry weight ratios, inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin (IL)-1 β, and IL-18] contents, numbers of autophagosome, and the protein expression levels of autophagy genes [microtubule-associated protein light chain3 (LC3)-Ⅱ/LC3-Ⅰand Beclin-1] were detected. Results In the control group, the 72-hour cumulative survival rate was 100%, the lung wet weight /dry weight ratio was 3.89±0.85, the TNF-α, IL-1β, and IL-18 contents were (0.83±0.14) ng/mg, (0.74±0.15) ng/mg, and (84.51±13.25) pg/mg, respectively, the number of autophagosome was (0.41±0.09)/field, and the expression levels of LC3-Ⅱ/LC3-Ⅰ and Beclin-1 were 0.20±0.04 and 0.17±0.03, respectively. In the model group, the lung tissue showed typical ALI pathological changes, the 72-hour cumulative survival rate (50%) was lower than that in the control group, and the lung wet weight /dry weight ratio (6.77±0.94), contents of TNF-α, IL-1β, and IL-18 [(3.15±0.76) ng/mg, (2.88±0.62) ng/mg, (274.62±45.58) pg/mg], autophagosome number [(3.14±0.55)/field], and expression levels of LC3-Ⅱ/LC3-Ⅰ and Beclin-1 (0.69±0.09, 0.35±0.06) were higher than those in the control group (P<0.05). In the Xuebijing group, the ALI pathological changes alleviated, the 72-hour cumulative survival rate (75%), autophagosome number [(5.77±0.75)/field], and expression levels of LC3-Ⅱ/LC3-Ⅰ and Beclin-1 (0.98±0.13, 0.62±0.08) were higher than those in the model group (P<0.05), and the lung wet weight /dry weight ratio (4.23±0.76) and contents of TNF-α, IL-1β, and IL-18 [(1.52±0.32) ng/mg, (1.29±0.30) ng/mg, (121.36±26.51) pg/mg] were lower than those in the model group (P<0.05). In the Xuebijing+3MA group, the ALI pathological changes aggravated, the 72-hour cumulative survival rate (55%), autophagosome number [(0.78±0.16)/field], and expression levels of LC3-Ⅱ/LC3-Ⅰ and Beclin-1 (0.37±0.05, 0.32±0.05) were lower than those in the Xuebijing group (P<0.05), and the lung wet weight /dry weight ratio (6.31±0.91) and contents of TNF-α, IL-1β, and IL-18 [(2.88±0.56) ng/mg, (2.41±0.58) ng/mg, (252.35±37.65) pg/mg] were higher than those in the Xuebijing group (P<0.05). Conclusion Xuebijing injection can reduce ALI induced by sepsis in mice, and activation of autophagy is the molecular mechanism.
Objective To realize the research progress of regulating the endoplasmic reticulum stress response to inhibit autophagy in tumor cells. Method The literatures about regulating the endoplasmic reticulum stress response to inhibit autophagy in tumor cells were reviewed. Result In the endoplasmic reticulum stress response induced by the release of calcium and accumulation of unfolded proteins, autophagy can be activated by several pathways, and to regulate physiological and pathological processes. Conclusion Further research about the endoplasmic reticulum stress response in tumor cells need to be done to regulate the response factors to inhibit autophagy.
Objective To investigate the effects and mechanism of 3-methyladenine （3-MA， an autophagy inhib-itor） on the apoptosis of hepatocellular carcinoma cell line SMMC7721 induced by 5-fluorouracil （5-FU）. Methods The autophagy was observed using fluorescent microscope by monodansyicadaverin （MDC） staining. The viability of SMMC-7721 cell induced by 5-FU was measured using CCK8 assay before and after autophagy inhibited by 3-MA， meanwhile the apoptosis of SMMC7721 cell was determined via AnnexinⅤ/PI assay. The light chain 3 protein （LC3， the autophagy specific protein） and caspase-3， PARP protein were detected by Western blot. Results The autophagy of SMMC7721 cell could be induced by 5-FU after treatment for 48 h， the cell survival rate was （60.73±2.65）%， and the apoptosis rate was （40.42±2.34）%. Compared with the group of 5-FU treatment， the survival rate of SMMC7721 cell in the combination of 5-FU and 3-MA after treatment for 48 h decreased to （42.31±1.32）% （P＜0.01）， and the apoptosis rate increased to （60.92±2.99）% （P＜0.01）， meanwhile the expressions of LC3-Ⅱ， activation fragment of caspase-3， and cleavage frag-ment of PARP significantly increased （P＜0.01）. Conclusions Autophagy is a protective phenomenon during the SMMC7721 cell line apoptosis induced by 5-FU， and autophagy inhibition may enhance the sensitivity of SMMC7721 cell line to 5-FU treatment， which is probably associated with the activation of caspase-3 and cleavage of PARP. Therefore， autophagy inhibition could be a promising strategy for adjuvant chemotherapy in hepatocellular carcinoma.
Autophagy is a programmed cell degradation process that is involved in a variety of physiological and pathological processes including malignant tumors. Abnormal induction of autophagy plays a key role in the development of hepatocellular carcinoma (HCC). We established a prognosis prediction model for hepatocellular carcinoma based on autophagy related genes. Two hundred and four differentially expressed autophagy related genes and basic information and clinical characteristics of 377 registered hepatocellular carcinoma patients were retrieved from the cancer genome atlas database. Cox risk regression analysis was used to identify autophagy-related genes associated with survival, and a prognostic model was constructed based on this. A total of 64 differentially expressed autophagy related genes were identified in hepatocellular carcinoma patients. Five risk factors related to the prognosis of hepatocellular carcinoma patients were determined by univariate and multivariate Cox regression analysis, including TMEM74, BIRC5, SQSTM1, CAPN10 and HSPB8. Age, gender, tumor grade and stage, and risk score were included as variables in multivariate Cox regression analysis. The results showed that risk score was an independent prognostic risk factor for patients with hepatocellular carcinoma (HR = 1.475, 95% CI = 1.280–1.699, P < 0.001). In addition, the area under the curve of the prognostic risk model was 0.739, indicating that the model had a high accuracy in predicting the prognosis of hepatocellular carcinoma. The results suggest that the new prognostic risk model for hepatocellular carcinoma, established by combining the molecular characteristics and clinical parameters of patients, can effectively predict the prognosis of patients.
ObjectiveTo investigate the role of autophagy-lysosomal system in skeletal muscle atrophy in rats with chronic obstructive pulmonary disease (COPD). MethodsPassive cigarette smoking was used to establish COPD model. The mRNA and protein expression of FOXO transcription factor and autophagy-related genes Bnip3, Beclin1, p62, MAP-LC3Ⅱ/Ⅰ, Atg5 in extensor digitorum longus of rats were measured by real time PCR and Western blot. The changes of extensor digitorum longus tissue sections and lung tissue sections in the experimental group rats were observed under transmission electron microscopy. ResultsCompared with the control group, the mRNA expression of FOXO transcription factor and autophagy-related genes Bnip3, Beclin1, p62, Atg5 in extensor digitorum longus of the experimental group group rats was significantly increased (all P<0.05, as for Bnip3, the P value between two groups <0.01); The mRNA expression of MAP-LC3Ⅱ/Ⅰwas not significantly different between two groups (P>0.05). The protein expression of FOXO, Bnip3, Beclin1, p62, MAP-LC3Ⅱ/Ⅰ, Atg5 significantly increased in the COPD group (all P<0.05, as for Bnip3, MAP-LC3Ⅱ/Ⅰ, Beclin1, the P values between two groups <0.01). Compared with the control group, autolysosome in extensor digitorum longus tissue sections of the experimental group rats increased and lung tissue fibrosis and more inflammatory cells were observed in lung tissue sections of the experimental group rats under transmission electron microscopy. ConclusionThe mRNA and protein expressions of FOXO transcription factor and autophagy-related genes in extensor digitorum longus increase significantly in the experimental group rats, suggesting that the activity of autophagy-lysosomal system, which may be one mechanism of skeletal muscle atrophy in COPD.
ObjectiveThe abnormal autophagy fluxis involved in the pathophysiological process of drug-resistance temporal lobe epilepsy (TLE).Hippocampal sclerosis (HS) is the main pathological type of drug-resistance TLE.Different subtypes of HS have various prognosis, etiology and pathophysiology.However, whether theabnormal block ofautophagy flux involved in this process has not been reported.This study proposed a preliminary comparison of autophagy fluxin typical and atypical HS to investigate the potential pathogenesis and drug-resistance mechanism of atypical HS. MethodsSurgical excision of hippocampal and temporal lobe epilepsy foci were performed in 17 patients with drug-resistance TLE.Patients were grouped according to the HS classification issued by International League Against Epilepsy in 2013.The distribution and expression of LC3B, beclin-1 and P62 were detected by immunohistochemistry and Western blot in each group. ResultsLC3B, beclin-1 and P62 are mainly expressed in neuronal cytoplasm, which is consistent with previous reports.Taking β-actin as internal reference, we found that LC3B and Beclin-1, the downstream products of autophagy flux, have increased significantly (P < 0.01) in the atypical HS group compared to typical HS group.However, the autophagy flux substrate P62 has no difference between the groups.This result suggested that compared with the typical HS group, atypical HS group had autophagy substrate accumulation and autophagy flux abnormal block.Besides, we found that glyceraldehycle-3-phosphate dehydrogenase(GAPDH) was significantly different between the two groups (P=0.003). ConclusionThere is abnormal phenomenon of autophagy flux in atypical HS, and GAPDH elevation may be involved in its mechanism, which might provide new targets and ideas for future treatment of atypical HS.
ObjectiveTo summarize the autophagy and its research progress in gastric cancer. MethodsIn combination with available literatures published in recent years involving the relationship between autophagy and gastric cancer, the characteristics of autophagy, molecular marker, control factors, and the significance and role in gastric cancer were reviewed. ResultsAutophagy not only promotes cell death, but also can prolong the survival of cancer cells during the tumor formation. Reagents (including traditional Chinese medicine) regulating autophagy have broad prospect of application in cancer therapy, but anti-tumor therapeutic effect based on the regulation of autophagy depends on the actual level of intracellular autophagy. ConclusionThe autophagy in the gastric cancer is still poorly understood, and to clarify the molecular mechanism of autophagy and kill cancer cells by reasonable regulation of autophagy still needs more further in-depth studies.
ObjectiveTo explore the effect of fingolimod (FTY720) on secondary nerve injury after thalamic-ventricle hemorrhage (TH-IVH) in rats.MethodsAdult male Sprague Dawley rats (clean animal) were randomly divided into 3 groups: sham group, TH-IVH group, and intervention group (FTY720 group), with 6 rats in each group. TH-IVH model was established in both TH-IVH group and FTY720 group, but only the rats in FTY720 group were treated with FTY720. The observation was conducted at the 1st, 3rd and 7th day after modeling. The main observation index included scores of neurological function, change of body weight, water content of brain tissue, the activation of inflammatory cells, the degree of neuronal degeneration and apoptosis, and the level of cell autophagy.ResultsAt the 1st, 3rd and 7th day after modeling, the change of body weight, the neurological score, brain edema and microglia activation in TH-IVH group were statistically different from those in sham group and FTY720 group (P<0.05). The number of degenerated neurons and the number of apoptotic cells in TH-IVH group were statistically different from those in sham group and FTY720 group at the 1st and 3rd day after modeling (P<0.05). The differences in the ratio of LC3Ⅱ/LC3Ⅰ protein expression andBcl-2/Bax expression were statistically significant between FTY720 group and TH-IVH group at the 1st and 3rd day after modeling (P<0.05).ConclusionsFTY720 can improve neurological function of the TH-IVH model in the acute phase, and has certain neuroprotective effect. The neuroprotective effect of FTY720 may be associated with neuronal autophagy and apoptosis regulation and immunosuppression.
Autophagy is a lysosome dependent, conservative material degradation process, which exists in all eukaryotic cells and plays import roles in many pathophysiology process. Erectile dysfunction (ED) is a common male disease with multiple etiology. In recent years, more and more evidences have demonstrated that autophagy has a close relation to ED, therefore, we combine previous study to classify ED by hypoxia, aging, diabetes and other causes, and review the advances of autophagy in ED.