Objective
To explore the relationship between Beclin-1 and the development of pancreatic ductal adenocarcinoma (PDAC).
Methods
① Twenty-five PDAC specimens and 20 matched adjacent normal pancreatic tissues were obtained after radical surgery between April 2009 and November 2009 in West China Hospital of Sichuan University. Beclin-1 mRNA and protein expressions were examined by using real-time PCR and immunohistochemistry, respectively. Correlations between expressions of Beclin-1 protein with clinical data of PDAC patients were evaluated. ② PDAC cells were divided into 2 groups, cells of transfection group were transfected with PLenO-WPI-Beclin-1 vector, and cells of non-transfection group didn’t transfected with PLenO-WPI-Beclin-1 vector. Expressions levels of Beclin-1 mRNA in the 2 groups were detected by real-time PCR at 24 hours and 48 hours after transfection. ③ PDAC cells were divided into 3 groups, cells of transfection group were transfected with PLenO-WPI-Beclin-1 vector, cells of empty vector group transfected with PLenO-WPI, cells of blank control group didn’t accepted any vector. OD value was detected by MTT once a day during 1–7 days after transfection.
Results
① Expression levels of Beclin-1 mRNA and its protein were significantly lower in PDAC tissue than those of adjacent normal pancreatic tissues (P<0.05). Increased Beclin-1 expression was associated with early TNM stage of Ⅰ and Ⅱ(P<0.05) and negative distant metastasis (P=0.011). ② At the same time point of 24 hours and 48 hours after transfection, the expression levels of Beclin-1 mRNA were higher in transfection group than those of non-transfection group (P<0.05). ③ MTT assay showed that PANC-1 cell proliferation ability was lower in the transfection group compared to the blank control group and empty vector groups in vitro on day 4–7 after transfection (P<0.05), but there was no significant in the cell proliferation ability among the 3 groups on day 1, 2, and 3 (P>0.05).
Conclusions
Down regulation of Beclin-1 and autophagy inhibition play an important role in the tumorigenesis and development of PDAC. Activating autophagy via overexpression of Beclin-1 may be a potential treatment for some PDACs and warrants further investigation.
Objective To explore the effect of SB431542 on monkey choroidal-retinal endothelial (RF/6A) cells in high glucose state and its mechanism of regulating mitochondrial autophagy by mediating the PINK1/Parkin pathway. MethodsCell experiments. The minimum effective drug concentration of SB431542 was determined by using the Cell Counting Kit-8 (CCK-8). RF/6A cells cultured in vitro were divided into normal group (NC group), mannitol group, high glucose group (HG group), high glucose with dimethyl sulfoxide group (HG + DMSO group), and high glucose + SB431542 group (HG + SB431542 group). CCK-8 and cell scratch assay were used to detect the proliferation and migration of RF/6A cells induced by high glucose. The expression of autophagosomes was detected by autophagy staining kit; the expression level of reactive oxygen species was detected by reactive oxygen species kit; the expression level of mitochondrial superoxide in cells was detected by MitoSOX fluorescent probe; the mitochondrial membrane potential level in cells was detected by JC-10 staining; the morphology of mitochondria was observed by MitoTracker staining, and the total area of mitochondria, average shape factor and branch length were quantitatively analyzed.Cellular immunofluorescence (IF) staining was used to detect the fluorescence expression of EndMT markers vimentin and VE-cadherin; Western blotting (WB) was used to detect the protein expression of vimentin, VE-cadherin, and mitochondrial autophagy-related proteins TOMM20, LC3, P62, PINK1, and Parkin; one-way analysis of variance was used for comparisons among multiple groups.ResultsThe minimum effective drug concentration of SB431542 was 5 μmol/L. SB431542 significantly inhibited the proliferation and migration of RF/6A cells induced by high glucose (F = 81.92、87.84, P＜0.000 1). SB431542 suppressed the expression of reactive oxygen species and mitochondrial superoxide induced by high glucose (F = 429.50, 450.20; P＜0.000 1), restored the mitochondrial membrane potential level (F = 315.3, P＜0.000 1), and restored the mitochondrial morphology (F = 209.50, P＜0.000 1). IF and WB confirmed that SB431542 inhibited the expression of Vimentin induced by high glucose (F = 117.30、51.11; P＜0.000 1) and upregulated the expression of VE-cadherin (F = 136.80、27.54; P＜0.000 1). WB further confirmed that SB431542 upregulated the protein expression of LC3, PINK1, and Parkin (F = 16.64, 37.72, 32.63; P＜0.05) and inhibited the protein expression of TOMM20 and P62 (F = 33.87, 67.77; P＜0.01). ConclusionSB431542 upregulates mitochondrial autophagy expression through activation of the PINK1/Parkin pathway, effectively restores mitochondria-related functions to maintain homeostasis, and inhibits high glucose-induced RF/6A cell proliferation,migration,and EndMT formation.
Hypoxia inducible factor-1 (HIF-1) is the main transcription factor and the core regulator for cells to adapt to hypoxia, and oxygen homeostasis is achieved by controlling and utilizing oxygen delivery. Autophagy and apoptosis play an important role in determining cell fate and maintaining cell homeostasis. In recent years, it has been found that the dynamic change of HIF-1 expression plays a key role in the hypoxic adaptive response of cardiomyocytes. The regulation of HIF-1 on autophagy and apoptosis of hypoxic cardiomyocytes determines the survival of cardiomyocytes, which is of great significance for the prognosis of ischemic heart disease.
Objective
To investigate whether miRNA (miR)-34a mediates oxaliplatin (OXA) resistance of colon cancer cells by inhibiting macroautophagy via the transforming growth factor (TGF)-β/Smad4 pathway.
Methods
miR-34a expression levels were detected in colon cancer tissues and colon cancer cell lines by quantitative real-time polymerase chain reaction (qRT-PCR). Computational search, functional luciferase assay, and Western blotting method were used to demonstrate the downstream target of miR-34a in colon cancer cells. Cell viability was measured with cell counting kit-8. Apoptosis and macroautophagy of colon cancer cells were analyzed by flow cytometry and transmission electron microscopy, and expressions of Beclin1 and LC3Ⅱ protein were detected by Western blotting method.
Results
Expression of miR-34a was significantly reduced while expressions of TGF-β and Smad4 mRNA were increased in colon cancer patients treated with OXA-based chemotherapy. OXA treatment also resulted in decreased miR-34a expression levels and increased TGF-β and Smad4 expression levels in both parental cells and the OXA-resistant colon cancer cells. Activation of macroautophagy contributed to OXA resistance in colon cancer cells. Expression levels of Smad4 and miR-34a in colon cancer patients had a significant inverse correlation and overexpressing miR-34a inhibited macroautophagy activation by directly targeting Smad4 through the TGF-β/Smad4 pathway. OXA-induced downregulation of miR-34a and increased drug resistance by activating macroautophagy in colon cancer cells.
Conclusion
miR-34a mediates OXA resistance of colon cancer by inhibiting autophagy via the TGF-β/Smad4 pathway.
Epilepsy is one of the most common neurological disorders, and status epilepticus (SE) can lead to permanent neuronal brain damage in the central nervous system, but the mechanism is not clear. Solving this problem will help to find more SE therapeutic targets, benefiting tens of millions of epilepsy patients. The pathway of SE leading to neuronal damage in the brain has made new progress in neuroinflammation, autophagy, apoptosis and pyroptosis, glial cell hyperplasia and category transformation, and changes in neurotransmitters in the brain, which will be beneficial to the discovery of new targets for the treatment of SE, thus laying a foundation for the development of new anti-epileptic drugs.
Neonatal broncho-pulmonary dysplasia (BPD) is a common chronic lung disease in premature infants, with a complex pathogenesis and limited treatment options, severely affecting health. In recent years, targeted autophagy and mesenchymal stem cell (MSC) have received attention as potential therapeutic approaches. Autophagy is crucial in the development of BPD, as it can improve pathological processes such as alveolarization disorders, abnormal pulmonary vascular development, and inflammatory responses through targeted regulation, and enhance the pulmonary microenvironment. Meanwhile, MSC is considered to have promising applications in promoting lung development and repair due to immune regulatory properties and paracrine functions. This article reviews the mechanisms and synergistic effects of targeted autophagy and MSC therapy for BPD, providing a theoretical basis for optimizing clinical treatment strategies for BPD and improving the quality of life of premature infants.
ObjectiveTo analyze the expression and significance of NF-κBp65 and autophagy-related proteins Beclin1 and p62 in patients with papillary thyroid carcinoma (PTC).MethodsOne hundred and sixty cases of PTC patients' tumor tissue specimens and paracancerous tissue specimens in our hospital from March 2013 to February 2015 were collected, and 90 cases of cervical lymph node metastasis tissue specimens of the above patients were collected. The expressions of NF-κBp65, Beclin1 and p62 in PTC tissues, metastatic lymph node tissues and paracancerous tissues were detected by immunohistochemical method, and the relationship between the above indexes and the clinicopathological characteristics and prognosis of PTC patients was analyzed.ResultsThe positive rates of expression of NF-kappa Bp65 and p62 in PTC tissues and metastatic lymph node tissues were higher than those in paracancerous tissues (P<0.05). The expression rate of Beclin1 in PTC tissues and metastatic lymph node tissues was lower than that in paracancerous tissues (P<0.05). The positive rate of NF-κBp65 expression in PTC tissues was not related to the clinicopathological characteristics of patients (P>0.05). The expression of p62 decreased with the increase of tumor differentiation (P<0.05). The expression of Beclin1 in patients with stage Ⅲ+Ⅳ and lymph node metastasis were lower than those in patients with stage Ⅰ+Ⅱ and without lymph node metastasis (P<0.05), while the expression of p62 was opposite. Spearman correlation analysis showed that the expression of Beclin1 and p62 in PTC tissues was negatively correlated (r=–0.656, P<0.01). In metastatic lymph node tissues, the expression of Beclin1 and p62 was also negatively correlated (r=–0.562, P<0.01). The 3-year survival rates of patients with positive expression of p62 and NF-κBp65 in PTC tissues were lower than that of patients with negative expression (P<0.05). The 3-year survival rate of patients with positive expression of Becrin1 was higher than that of negative expression (P<0.05). TNM stage, lymph node metastasis, NF-κBp65 and p62 were independent risk factors for PTC prognosis, and Beclin1 was protective factor.ConclusionsNF-κBp65 and p62 are highly expressed in PTC tissues and lymph node metastasis tissues, while Beclin1 is poorly expressed, which could be used as independent prognostic factors for PTC patients. In addition, Beclin1 and p62 are related to PTC biological behavior and may become potential indicators for PTC diagnosis.
ObjectiveTo investigate the mechanism of magnesium sulfate in protecting rabbit cartilage by initiating autophagy.MethodsTwenty-four adult female New Zealand rabbits were used to prepare post-traumatic osteoarthritis (PTOA) models by anterior cruciate ligament transection. Then, the PTOA models were randomly divided into PTOA group, distilled water group, and magnesium sulfate group, with 8 rabbits in each group. Immediately after operation, the distilled water group and the magnesium sulfate group were injected with 0.5 mL distilled water and 20 mmol/L magnesium sulfate solution in the joint cavity 3 times a week for 4 weeks, respectively. The PTOA group was not treated. The general condition of the animals was observed after operation. After 4 weeks, the expressions of tumor necrosis factor α (TNF-α) and collagen typeⅡ in the joint fluid and the expression of collagen type Ⅱ in venous blood were detected by ELISA assay. The protein expressions of transient receptor potential channel vanilloid 5 (TRPV5) and microtubule associated protein 1 light chain 3 (LC3; LC3-Ⅱ/LC3-Ⅰ) in femoral cartilage were detected by Western blot. The mRNA expressions of interleukin 1β (IL-1β), TNF-α, matrix metalloproteinases 3 (MMP-3) in synovial tissue and collagen type Ⅱ, Aggrecan (AGN), SOX9 in cartilage tissue were detected by real-time fluorescence quantitative PCR. Cartilage tissue sections were stained with HE staining, Masson staining, and Alcian blue staining and scored according to the modified histological osteoarthritis (OA) score.ResultsAll animals survived until the experiment was completed. Compared with the other two groups, the expression of TNF-α in joint effusion and collagen type Ⅱ in joint effusion and venous blood were decreased in magnesium sulfate group; the protein expression of TRPV5 decreased, and the ratio of LC3-Ⅱ/LC3-Ⅰ increased significantly; the mRNA expressions of IL-1β, TNF-α, and MMP-3 in synovial tissue were decreased, and the mRNA expressions of collagen type Ⅱ, AGN, and SOX9 in cartilage tissue were increased; OA scores also decreased significantly. All differences were statistically significant (P<0.05). There was no significant difference in the above indicators between the PTOA group and the distilled water group (P>0.05).ConclusionIntra-articular injection of magnesium sulfate can reduce intra-articular inflammation, reduce the loss of collagen type Ⅱ and AGN, and is beneficial to cartilage regeneration in rabbits. The mechanism may be related to the initiation of chondroautophagy by inhibiting the calcium channel TRPV5.
ObjectiveTo investigate the role of p22phox and NOX5 in autophagy and apoptosis of osteoblasts induced by hypoxia.MethodsThe skull tissue of newborn rats was cut into small pieces, and the osteoblasts were separated and purified by the tissue block adherent method and the differential adherent method. The first generation cells were harvested and identified by HE staining, Alizarin red staining, alkaline phosphatase (ALP) staining, and flow cytometry. A three-gas incubator was used to prepare a hypoxia model of osteoblasts. At 0, 3, 6, 12, and 24 hours of hypoxia, the expressions of p22phox, NOX5, and LC3Ⅱ/Ⅰ were detected by Western blot, and the level of reactive oxygen species (ROS) and cell apoptosis rate were detected by flow cytometry. And the time point of the highest level of ROS was selected as the hypoxia time point for subsequent experiments. The first generation osteoblasts were divided into normal group, si-p22phox hypoxia group, and si-NOX5 hypoxia group and subjected to corresponding transfection and hypoxia treatment. The inhibition efficiency of si-p22phox and si-NOX5 were detected by RT-PCR. Then the osteoblasts were divided into normal group, si-NC hypoxia group, si-p22phox hypoxia group, and si-NOX5 hypoxia group. After transfection and hypoxia treatment, Western blot was used to detect the expressions of p22phox, NOX5, autophagy-related proteins (LC3Ⅱ/Ⅰ, Beclin), and apoptosis-related proteins (Bcl-2, Bax), and flow cytometry was used to detect the cell apoptosis rate and level of ROS. The first generation osteoblasts were divided into a hypoxia group for 12 hours (hypoxia group) and a group that simultaneously inhibited si-p22phox and si-NOX5 and hypoxia for 12 hours (inhibition+hypoxia group). The expressions of Beclin and Bax were observed by immunofluorescence staining after the corresponding treatment.ResultsAfter identification, the isolated cells were osteoblasts. After hypoxia treatment, the relative expressions of p22phox, NOX5, and LC3Ⅱ/Ⅰ proteins and the apoptosis rate of osteoblasts gradually increased (P<0.05), and the level of ROS also significantly increased (P<0.05) and reached the peak value at 12 hours. The 12-hour hypoxia model was selected for subsequent experiments. Silencing the p22phox gene did not affect the expression of NOX5, and silencing the NOX5 gene did not affect the expression of p22phox. Compared with hypoxia treatment, the relative expressions of LC3Ⅱ/Ⅰ, Beclin, and Bax proteins after inhibiting the expression of p22phox or NOX5 gene significantly decreased (P<0.05), the relative expression of Bcl-2 protein significantly increased (P<0.05), the cell apoptosis rate and level of ROS also significantly decreased (P<0.05). After silencing the expressions of p22phox and NOX5 genes at the same time, the immunofluorescence staining showed that the fluorescence of Beclin and Bax were weak.ConclusionInhibiting the expressions of p22phox and NOX5 genes can reduce the level of ROS in osteoblasts under hypoxia-induced conditions, and at the same time reduce autophagy and apoptosis, especially attenuate the excessive apoptosis of cells in the early to late stages, and strengthen the hypoxic osteoblasts proliferation.
ObjectiveTo summarize the role of chondrocyte mitochondrial homeostasis imbalance in the pathogenesis of osteoarthritis (OA) and analyze its application prospects. Methods The recent literature at home and abroad was reviewed to summarize the mechanism of mitochondrial homeostasis imbalance, the relationship between mitochondrial homeostasis imbalance and the pathogenesis of OA, and the application prospect in the treatment of OA. Results Recent studies have shown that mitochondrial homeostasis imbalance, which is caused by abnormal mitochondrial biogenesis, the imbalance of mitochondrial redox, the imbalance of mitochondrial dynamics, and damaged mitochondrial autophagy of chondrocytes, plays an important role in the pathogenesis of OA. Abnormal mitochondrial biogenesis can accelerate the catabolic reaction of OA chondrocytes and aggravate cartilage damage. The imbalance of mitochondrial redox can lead to the accumulation of reactive oxygen species (ROS), inhibit the synthesis of extracellular matrix, induce ferroptosis and eventually leads to cartilage degradation. The imbalance of mitochondrial dynamics can lead to mitochondrial DNA mutation, decreased adenosine triphosphate production, ROS accumulation, and accelerated apoptosis of chondrocytes. When mitochondrial autophagy is damaged, dysfunctional mitochondria cannot be cleared in time, leading to ROS accumulation, which leads to chondrocyte apoptosis. It has been found that substances such as puerarin, safflower yellow, and astaxanthin can inhibit the development of OA by regulating mitochondrial homeostasis, which proves the potential to be used in the treatment of OA. Conclusion The mitochondrial homeostasis imbalance in chondrocytes is one of the most important pathogeneses of OA, and further exploration of the mechanisms of mitochondrial homeostasis imbalance is of great significance for the prevention and treatment of OA.
