1.Celastrol activates caspase-3/GSDME-dependent pyroptosis in tumor cells by inducing endoplasmic reticulum stress
Jiajian Guo ; Dongxiao Cui ; Yuping Tang ; Sanjiao Wang ; Cuiyan Ma ; Wenfu Ma
Journal of Traditional Chinese Medical Sciences 2024;11(3):330-339
Objective:
To investigate the pyroptosis-inducing effects of celastrol on tumor cells and to explore the potential mechanisms involved, specifically focusing on the role of the caspase-3/gasdermin E (GSDME) signaling pathway and the impact of endoplasmic reticulum (ER) stress and autophagy.
Methods:
Necrostatin-1 (Nec-1), lactate dehydrogenase release (LDH) assay, and Hoechst/propidium iodide (PI) double staining were employed to validate the mode of cell death. Western blot was used to detect the cleavage of GSDME and the expression of light chain 3 (LC3) and BIP.
Results:
Celastrol induced cell swelling with large bubbles, which is consistent with the pyroptotic phenotype. Moreover, treatment with celastrol induced GSDME cleavage, indicating the activation of GSDME-mediated pyroptosis. GSDME knockout via CRISPR/Cas9 blocked the pyroptotic morphology of celastrol in HeLa cells. In addition, cleavage of GSDME was attenuated by a specific caspase-3 inhibitor in celastrol-treated cells, suggesting that GSDME activation was induced by caspase-3. Mechanistically, celastrol induced endoplasmic reticulum (ER) stress and autophagy in HeLa cells, and other ER stress inducers produced effects consistent with those of celastrol.
Conclusion
These findings suggest that celastrol triggers caspase-3/GSDME-dependent pyroptosis via activation of ER stress, which may shed light on the potential antitumor clinical applications of celastrol.
2.DTI evaluation of mild articular cartilage injury in patellofemoral joint: Comparison with arthroscopy
Min LI ; Demao DENG ; Chunhua FU ; Liheng MA ; Peiyi SUN ; Shasha LI ; Hai LIAO ; Xiaomei WEI ; Gaoxiong DUAN ; Fang LUO ; Wenfu CHEN
Chinese Journal of Medical Imaging Technology 2017;33(7):1071-1075
Objective To evaluate the value of DTI in mild articular cartilage injury in patellofemoral joint.Methods The DTI and arthroscopy data of 82 patients wih routine MRI diagnosed as mild articular cartilage injury were analyzed retrospectively.According to the results of arthroscopy,40 cases of mild articular cartilage injury with Outerbridge classification Ⅰ or Ⅱ were divided into experimental group,and 33 cases with normal patellofemoral articular cartilage were divided into control group.There were 8 articular cartilage injury patients with Outerbridge classification Ⅲ or Ⅳ in patello-femoral join were excluded.The DTI data were analyzed compared with arthroscopy.Results Arthroscopy detected 62 lesions of cartilage injury in experimental group.Totally 49 lesions (49/62,79.03 %) were detected by ADC pseudocolor image and 51 lesions (51/62,82.25 %) were detected by FA pseudocolor image.The DTI pseudocolor images of articular cartilage injury showed uneven levels.The red or pink levels can been observed.Compared with the control group,ADC value increased and FA value decreased significantly in experimental group (both P<0.05).Conclusion DTI can clearly display and detect mild articular cartilage injury in patellofemoral joint,which provide valuable information for early cartilaginous injury.
3.CHESS endoscopic ruler in objective measurement of diameter of esophageal varices in liver cirrhosis and portal hypertension: a prospective multicenter study
Shengjuan HU ; Jianping HU ; Shaoqi YANG ; Xiaoguo LI ; Yanhong DENG ; Ruichun SHI ; Xiaoqin LI ; Hailong QI ; Qian SHEN ; Fang HE ; Jun ZHU ; Bin MA ; Xiaobing YU ; Jianyang GUO ; Yuehua YU ; Haijiang YONG ; Wentun YAO ; Ting YE ; Hua WANG ; Wenfu DONG ; Jianguo LIU ; Qiang WEI ; Jing TIAN ; Haoxiang HE ; Changhui HE ; Yifei HUANG ; Yang BU ; Xiaolong QI
Chinese Journal of Digestion 2023;43(3):193-198
Objective:To investigate the safety and feasibility of the CHESS endoscpic ruler (CHESS ruler), and the consistency between the measured values and the interpretation values by endoscopic physician experience.Methods:From January 2021 to January 2022, a total of 105 liver cirrhosis patients with portal hypertension were prospectively enrolled from General Hospital, Xixia Branch Hospital, Ningnan Hospital of People′s Hospital of Ningxia Hui Autonomous Region (29 cases), and the First People′s Hospital of Yinchuan (25 cases), General Hospital of Ningxia Medical University (18 cases), Wuzhong People′s Hospital (10 cases), the Fifth People′s Hospital of Ningxia Hui Autonomous Region (10 cases), Shizuishan Second People′s Hospital (6 cases), Yinchuan Second People′s Hospital (5 cases), and Zhongwei People′s Hospital (2 cases) 8 hospitals. The clinical characteristics of all the patients, including gender, age, nationality, etiolog of liver cirrhosis, and Child-Pugh classification of liver function were recorded. A big gastroesophageal varices was defined as diameter of varices ≥5 mm. Endoscopist (associated chief physician) performed gastroscopy according to the routine gastroscopy procedures, and the diameter of the biggest esophageal varices was measured by experience and images were collected, and then objective measurement was with the CHESS ruler and images were collected. The diameter of esophageal varices of 10 randomly selected patients (random number table method) was determined by 6 endoscopists (attending physician or associated chief physician) with experience or measured by CHESS ruler. Kappa test was used to test the consistency in the diameter of esophageal varices between measured values by CHESS ruler and the interpretation values by endoscopic physician experience.Results:Among 105 liver cirrhosis patients with portal hypertension, male 65 cases and female 40 cases, aged (54.8±12.2) years old, Han nationality 82 cases, Hui nationality 21 cases and Mongolian nationality 2 cases. The etiology of liver cirrhosis included chronic hepatitis B (79 cases), alcoholic liver disease (7 cases), autoimmune hepatitis (7 cases), chronic hepatitis C (2 cases), and other etiology (10 cases). Liver function of 32 cases was Child-Pugh A, Child-Pugh B 57 cases, and Child-Pugh C 16 cases. All 105 liver cirrhosis patients with cirrhotic portal hypertension were successfully measured the diameter of gastroesophageal varices by CHESS ruler, and the success rate of application of CHESS ruler was 100.0% (105/105). The procedure time from the CHESS ruler into the body to the exit of the body after measurement was (3.50±2.55) min. No complications happened in all the patients during measurement. Among 105 liver cirrhosis patients with cirrhotic portal hypertension, 96 cases (91.4%) were recognized as big gastroesophageal varices by the endoscopists. Totally 93 cases (88.6%) were considered as big gastroesophageal varices by CHESS ruler. Eight cases were recognized as big gastroesophageal varices by the endoscopist, however not by the CHESS ruler; 5 cases were recognized as big gastroesophageal varices by the CHESS ruler, but not by the endoscopists; 4 cases were not recognized as big gastroesophageal varices both by the endoscopists and CHESS ruler; 88 cases were recognized as big gastroesophageal varices both by the endoscopists and CHESS ruler. The missed diagnostic rate of big gastroesophageal varices by the endoscopists experience was 5.4% (5/93), and the Kappa value of consistency coefficient between the measurement by the CHESS ruler and the interpretation by endoscopists experience was 0.31 (95% confidence interval 0.03 to 0.60). The overall Kappa value of consistency coefficient by 6 endoscopists measured by CHESS ruler in big gastroesophageal varices diagnosis was 0.77 (95% confidence interval 0.61 to 0.93).Conclusion:As an objective measurement tool, CHESS ruler can make up for the deficiency of subjective judgment by endoscopists, accurately measure the diameter of gastroesophageal varices, and is highly feasible and safe.
4.SARS-CoV-2 spike host cell surface exposure promoted by a COPI sorting inhibitor.
Yiqun LI ; Mingrui YANG ; Yanan NAN ; Jiaming WANG ; Sanjiao WANG ; Dongxiao CUI ; Jiajian GUO ; Pengfei HE ; Wenxin DAI ; Shuqi ZHOU ; Yue ZHANG ; Wenfu MA
Acta Pharmaceutica Sinica B 2023;13(7):3043-3053
Via an insufficient coat protein complex I (COPI) retrieval signal, the majority of SARS-CoV-2 spike (S) is resident in host early secretory organelles and a tiny amount is leaked out in cell surface. Only surface-exposed S can be recognized by B cell receptor (BCR) or anti-S therapeutic monoclonal antibodies (mAbs) that is the trigger step for B cell activation after S mRNA vaccination or infected cell clearance by S mAbs. Now, a drug strategy to promote S host surface exposure is absent. Here, we first combined structural and biochemical analysis to characterize S COPI sorting signals. A potent S COPI sorting inhibitor was then invented, evidently capable of promoting S surface exposure and facilitating infected cell clearance by S antibody-dependent cellular cytotoxicity (ADCC). Importantly, with the inhibitor as a probe, we revealed Omicron BA.1 S is less cell surface exposed than prototypes because of a constellation of S folding mutations, possibly corresponding to its ER chaperone association. Our findings not only suggest COPI is a druggable target against COVID-19, but also highlight SARS-CoV-2 evolution mechanism driven by S folding and trafficking mutations.
5.Structural mechanism of a dual-functional enzyme DgpA/B/C as both a C-glycoside cleaving enzyme and an O- to C-glycoside isomerase.
Pengfei HE ; Sha WANG ; Sen LI ; Siqi LIU ; Shuqi ZHOU ; Jing WANG ; Jiayue TAO ; Dongdong WANG ; Rufeng WANG ; Wenfu MA
Acta Pharmaceutica Sinica B 2023;13(1):246-255
The C-glycosidic bond that connects the sugar moiety with aglycone is difficult to be broken or made due to its inert nature. The knowledge of C-glycoside breakdown and synthesis is very limited. Recently, the enzyme DgpA/B/C cascade from a human intestinal bacterium PUE was identified to specifically cleave the C-glycosidic bond of puerarin (daidzein-8-C-glucoside). Here we investigated how puerarin is recognized and oxidized by DgpA based on crystal structures of DgpA with or without substrate and biochemical characterization. More strikingly, we found that apart from being a C-glycoside cleaving enzyme, DgpA/B/C is capable of efficiently converting O- to C-glycoside showing the activity as a structure isomerase. A possible mechanistic model was proposed dependently of the simulated complex structure of DgpB/C with 3″-oxo-daidzin and structure-based mutagenesis. Our findings not only shed light on understanding the enzyme-mediated C-glycosidic bond breakage and formation, but also may help to facilitate stereospecific C-glycoside synthesis in pharmaceutical industry.