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result(s) for
"Li, Xiong"
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Activation of AMPK by simvastatin inhibited breast tumor angiogenesis via impeding HIF‐1α‐induced pro‐angiogenic factor
by
Liu, Pei‐Jun
,
Li, Xiong‐Xiong
,
Li, Guang‐Yue
in
AMP-Activated Protein Kinases - antagonists & inhibitors
,
AMP-Activated Protein Kinases - physiology
,
AMPK
2018
Substantial data from preclinical studies have revealed the biphasic effects of statins on cardiovascular angiogenesis. Although some have reported the anti‐angiogenic potential of statins in malignant tumors, the underlying mechanism remains poorly understood. The aim of this study is to elucidate the mechanism by which simvastatin, a member of the statin family, inhibits tumor angiogenesis. Simvastatin significantly suppressed tumor cell‐conditioned medium‐induced angiogenic promotion in vitro, and resulted in dose‐dependent anti‐angiogenesis in vivo. Further genetic silencing of hypoxia‐inducible factor‐1α (HIF‐1α) reduced vascular endothelial growth factor and fibroblast growth factor‐2 expressions in 4T1 cells and correspondingly ameliorated HUVEC proliferation facilitated by tumor cell‐conditioned medium. Additionally, simvastatin induced angiogenic inhibition through a mechanism of post‐transcriptional downregulation of HIF‐1α by increasing the phosphorylation level of AMP kinase. These results were further validated by the fact that 5‐aminoimidazole‐4‐carboxamide ribonucleotide reduced HIF‐1α protein levels and ameliorated the angiogenic ability of endothelial cells in vitro and in vivo. Critically, inhibition of AMPK phosphorylation by compound C almost completely abrogated simvastatin‐induced anti‐angiogenesis, which was accompanied by the reduction of protein levels of HIF‐1α and its downstream pro‐angiogenic factors. These findings reveal the mechanism by which simvastatin induces tumor anti‐angiogenesis, and therefore identifies the target that explains the beneficial effects of statins on malignant tumors. Simvastatin significantly suppressed tumor angiogenesis promoted by HIF‐1α‐induced pro‐angiogenic factors in 4T1 tumor cells. Further inhibition of AMPK phosphorylation by compound C almost completely abrogated simvastatin‐induced anti‐angiogenesis, which was accompanied by the reduction of protein levels of HIF‐1α and its downstream pro‐angiogenic factors.
Journal Article
Interplay between Müller cells and microglia aggravates retinal inflammatory response in experimental glaucoma
by
Wang, Zhongfeng
,
Xu, Meng-Xi
,
Zhou, Han
in
Activation
,
Adenosine Triphosphate - physiology
,
Animals
2021
Background
Glaucoma, the leading cause of irreversible blindness, is a retinal neurodegenerative disease, which results from progressive apoptotic death of retinal ganglion cells (RGCs). Although the mechanisms underlying RGC apoptosis in glaucoma are extremely complicated, an abnormal cross-talk between retinal glial cells and RGCs is generally thought to be involved. However, how interaction of Müller cells and microglia, two types of glial cells, contributes to RGC injury is largely unknown.
Methods
A mouse chronic ocular hypertension (COH) experimental glaucoma model was produced. Western blotting, immunofluorescence, quantitative real-time polymerase chain reaction (q-PCR), transwell co-culture of glial cells, flow cytometry assay, ELISA, Ca
2+
image, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) techniques were employed to investigate the interaction of Müller cells and microglia, and its underlying mechanisms in COH retina.
Results
We first showed that Müller cell activation in mice with COH induced microglia activation through the ATP/P2X7 receptor pathway. The activation of microglia resulted in a significant increase in mRNA and protein levels of pro-inflammatory factors, such as tumor necrosis factor-α and interleukin-6. These inflammatory factors in turn caused the up-regulation of mRNA expression of pro-inflammatory factors in Müller cells through a positive feedback manner.
Conclusions
These findings provide robust evidence, for the first time, that retinal inflammatory response may be aggravated by an interplay between activated two types of glial cells. These results also suggest that to reduce the interplay between Müller cells and microglia could be a potential effective strategy for preventing the loss of RGCs in glaucoma.
Journal Article
Enzyme-mediated nitric oxide production in vasoactive erythrocyte membrane-enclosed coacervate protocells
2020
The design and construction of synthetic therapeutic protocells capable of establishing cognate chemical communication channels with living cells is an important challenge for synthetic biology and bio-engineering. Here we develop a step towards protocell-mediated nitric-oxide-induced vasodilation by constructing a new synthetic cell model based on bio-derived coacervate vesicles with high haemocompatibility and increased blood circulation times. The hybrid protocells are prepared by the spontaneous self-assembly of haemoglobin-containing erythrocyte membrane fragments on the surface of preformed polysaccharide–polynucleotide coacervate micro-droplets containing glucose oxidase. We use the sequestered enzymes to program a spatially coupled glucose oxidase/haemoglobin reaction cascade, which in the presence of glucose and hydroxyurea generates a protocell-mediated flux of nitric oxide that we exploit for in vitro and in vivo blood vessel vasodilation. Taken together, our results provide new opportunities for the development of endogenously organized cell-like entities (biocompatible micro-bots) geared specifically towards active interfacing with individual living cells and cell communities.The self-assembly of haemoglobin-containing erythrocyte membrane fragments onto the surface of preformed coacervates has been used to make hybrid synthetic cells that can initiate nitric-oxide-induced vasodilation. These synthetic cells encapsulate enzymes that generate a flux of nitric oxide, as well as exhibiting high haemocompatibility and increased blood circulation times.
Journal Article
Hypofractionated versus conventional fractionated postmastectomy radiotherapy for patients with high-risk breast cancer: a randomised, non-inferiority, open-label, phase 3 trial
To our knowledge, no randomised study has compared postmastectomy hypofractionated radiotherapy with conventional fractionated radiotherapy in patients with breast cancer. This study aimed to determine whether a 3-week schedule of postmastectomy hypofractionated radiotherapy is as efficacious and safe as a 5-week schedule of conventional fractionated radiotherapy.
This randomised, non-inferiority, open-label, phase 3 study was done in a single academic hospital in China. Patients aged 18–75 years who had undergone mastectomy and had at least four positive axillary lymph nodes or primary tumour stage T3–4 disease were eligible to participate. Patients were randomly assigned (1:1) according to a computer-generated central randomisation schedule, without stratification, to receive chest wall and nodal irradiation at a dose of 50 Gy in 25 fractions over 5 weeks (conventional fractionated radiotherapy) or 43·5 Gy in 15 fractions over 3 weeks (hypofractionated radiotherapy). The modified intention-to-treat population (including all eligible patients who underwent randomisation but excluding those who were considered ineligible or withdrew consent after randomisation) was used in primary and safety analyses. The primary endpoint was 5-year locoregional recurrence, and a 5% margin was used to establish non-inferiority (equivalent to a hazard ratio <1·883). This trial is registered at ClinicalTrials.gov, number NCT00793962.
Between June 12, 2008, and June 16, 2016, 820 patients were enrolled and randomly assigned to the conventional fractionated radiotherapy group (n=414) or hypofractionated radiotherapy group (n=406). 409 participants in the conventional fractionated radiotherapy group and 401 participants in the hypofractionated radiotherapy group were included in the modified intention-to-treat analyses. At a median follow-up of 58·5 months (IQR 39·2–81·8), 60 (7%) patients had developed locoregional recurrence (31 patients in the hypofractionated radiotherapy group and 29 in the conventional fractionated radiotherapy group); the 5-year cumulative incidence of locoregional recurrence was 8·3% (90% CI 5·8–10·7) in the hypofractionated radiotherapy group and 8·1% (90% CI 5·4–10·6) in the conventional fractionated radiotherapy group (absolute difference 0·2%, 90% CI −3·0 to 2·6; hazard ratio 1·10, 90% CI 0·72 to 1·69; p<0·0001 for non-inferiority). There were no significant differences between the groups in acute and late toxicities, except that fewer patients in the hypofractionated radiotherapy group had grade 3 acute skin toxicity than in the conventional fractionated radiotherapy group (14 [3%] of 401 patients vs 32 [8%] of 409 patients; p<0·0001).
Postmastectomy hypofractionated radiotherapy was non-inferior to and had similar toxicities to conventional fractionated radiotherapy in patients with high-risk breast cancer. Hypofractionated radiotherapy could provide more convenient treatment and allow providers to treat more patients.
National Key Projects of Research and Development of China; the Chinese Academy of Medical Science Innovation Fund for Medical Sciences; and Beijing Marathon of Hope, Cancer Foundation of China.
Journal Article
Evolution and function of developmentally dynamic pseudogenes in mammals
by
Qian, Sheng Hu
,
Chen, Zhen-Xia
,
Chen, Lu
in
Animal Genetics and Genomics
,
Animals
,
Bioinformatics
2022
Background
Pseudogenes are excellent markers for genome evolution, which are emerging as crucial regulators of development and disease, especially cancer. However, systematic functional characterization and evolution of pseudogenes remain largely unexplored.
Results
To systematically characterize pseudogenes, we date the origin of human and mouse pseudogenes across vertebrates and observe a burst of pseudogene gain in these two lineages. Based on a hybrid sequencing dataset combining full-length PacBio sequencing, sample-matched Illumina sequencing, and public time-course transcriptome data, we observe that abundant mammalian pseudogenes could be transcribed, which contribute to the establishment of organ identity. Our analyses reveal that developmentally dynamic pseudogenes are evolutionarily conserved and show an increasing weight during development. Besides, they are involved in complex transcriptional and post-transcriptional modulation, exhibiting the signatures of functional enrichment. Coding potential evaluation suggests that 19% of human pseudogenes could be translated, thus serving as a new way for protein innovation. Moreover, pseudogenes carry disease-associated SNPs and conduce to cancer transcriptome perturbation.
Conclusions
Our discovery reveals an unexpectedly high abundance of mammalian pseudogenes that can be transcribed and translated, and these pseudogenes represent a novel regulatory layer. Our study also prioritizes developmentally dynamic pseudogenes with signatures of functional enrichment and provides a hybrid sequencing dataset for further unraveling their biological mechanisms in organ development and carcinogenesis in the future.
Journal Article
A Hybrid Optical Fiber Detector for the Simultaneous Measurement of Dust Concentration and Temperature
2025
This work presents a hybrid optical fiber detector by combining the sensing mechanism of the fiber Bragg grating (FBG) and the light extinction method to enable the simultaneous measurement of dust concentration and temperature. Compared with the existing dust concentration sensors, the proposed detector offers three key advantages: intrinsic safety, dual-parameter measurement capability, and potentially network-based monitoring. The critical sensing components of the proposed detector consist of two optical collimators and an FBG. Using the extinction effect of light between the two collimators, the dust concentration and temperature are simultaneously determined by monitoring the intensity and the wavelength of the FBG reflectance spectrum, respectively. The measurement feasibility has been evaluated demonstrating that the two parameters of interest can be effectively sensed with minimally coupled outputs of ±3 pm and ±0.1 mW, respectively. Calibration experiments demonstrate that the change in the intensity of light from the FBG is exponentially related to the dust concentration variation with fitting coefficients equal to 0.948, 0.946, and 0.945 for 200 meshes, 300 meshes, and 400 meshes, respectively. The detector’s relative measurement errors were validated against the weighing method, confirming low measurement deviations.
Journal Article
PGK1 contributes to tumorigenesis and sorafenib resistance of renal clear cell carcinoma via activating CXCR4/ERK signaling pathway and accelerating glycolysis
2022
Phosphoglycerate kinase 1 (PGK1) has complicated and multiple functions in cancer occurrence, tumor progression and drug resistance. Sorafenib is the first-line treatment targeted drug for patients with kidney renal clear cell carcinoma (KIRC) as a tyrosine kinase inhibitor, but sorafenib resistance is extremely common to retard therapy efficiency. So far, it is unclear whether and how PGK1 is involved in the pathogenesis and sorafenib resistance of KIRC. Herein, the molecular mechanisms of PGK1-mediated KIRC progression and sorafenib resistance have been explored by comprehensively integrative studies using biochemical approaches, mass spectrometry (MS) identification, microarray assay, nude mouse xenograft model and bioinformatics analysis. We have confirmed PGK1 is specifically upregulated in KIRC based on the transcriptome data generated by our own gene chip experiment, proteomics identification and the bioinformatics analysis for five online transcriptome datasets, and PGK1 upregulation in tumor tissues and serum is indicative with poor prognosis of KIRC patients. In the KIRC tissues, a high expression of PGK1 is often accompanied with an increase of glycolysis-related enzymes and CXCR4. PGK1 exhibits pro-tumorigenic properties in vitro and in a xenograft tumor model by accelerating glycolysis and inducing CXCR4-mediated phosphorylation of AKT and ERK. Moreover, PGK1 promotes sorafenib resistance via increasing CXCR4-mediated ERK phosphorylation. In conclusion, PGK1-invovled metabolic reprogramming and activation of CXCR4/ERK signaling pathway contributes to tumor growth and sorafenib resistance of KIRC.
Journal Article
Mixed Maximum Loss Design for Optic Disc and Optic Cup Segmentation with Deep Learning from Imbalanced Samples
by
Lu, Shuai
,
Xu, Yong-li
,
Li, Han-xiong
in
Accuracy
,
convolutional neural network
,
Deep learning
2019
Glaucoma is a serious eye disease that can cause permanent blindness and is difficult to diagnose early. Optic disc (OD) and optic cup (OC) play a pivotal role in the screening of glaucoma. Therefore, accurate segmentation of OD and OC from fundus images is a key task in the automatic screening of glaucoma. In this paper, we designed a U-shaped convolutional neural network with multi-scale input and multi-kernel modules (MSMKU) for OD and OC segmentation. Such a design gives MSMKU a rich receptive field and is able to effectively represent multi-scale features. In addition, we designed a mixed maximum loss minimization learning strategy (MMLM) for training the proposed MSMKU. This training strategy can adaptively sort the samples by the loss function and re-weight the samples through data enhancement, thereby synchronously improving the prediction performance of all samples. Experiments show that the proposed method has obtained a state-of-the-art breakthrough result for OD and OC segmentation on the RIM-ONE-V3 and DRISHTI-GS datasets. At the same time, the proposed method achieved satisfactory glaucoma screening performance on the RIM-ONE-V3 and DRISHTI-GS datasets. On datasets with an imbalanced distribution between typical and rare sample images, the proposed method obtained a higher accuracy than existing deep learning methods.
Journal Article
SCARA5 induced ferroptosis to effect ESCC proliferation and metastasis by combining with Ferritin light chain
2022
Background
Esophageal squamous cell carcinoma (ESCC) remains one of the most lethal cancers worldwide accompany with an extremely poor prognosis. Therefore, this study aims to screen for new molecules affecting ESCC and explore their mechanisms of action to provide ideas for targeted therapies for ESCC.
Methods
Firstly, we screened out the membrane protein SCARA5 by high-throughput sequencing of the ESCC patient tissues, and RT-qPCR and WB were used to verify the differential expression of SCARA5 in esophageal cell lines, and IHC analyzed the expression localization of SCARA5 in ESCC tissue. Then, flow cytometry, wound healing assay, Transwell assay and CCK-8 assay were used to explore the effects of SCARA5 on cell cycle, migration and invasion as well as cell proliferation activity of esophageal squamous carcinoma cells. Meanwhile, transmission electron microscopy was used to detect changes in cellular mitochondrial morphology, and flow cytometry were used to detect changes in intracellular reactive oxygen metabolism, and immunofluorescence and flow cytometry were used to detect changes in intracellular Fe
2+
. Mechanistically, co-immunoprecipitation was used to detect whether SCARA5 binds to ferritin light chain, and ferroptosis-related protein expression was detected by WB. Finally, the tumor xenograft model was applied to validation the role of SCARA5 tumor growth inhibition in vivo.
Results
We found that SCARA5 was aberrantly decreased in ESCC tissues and cell lines. Furthermore, we confirmed that SCARA5 suppressed the cell cycle, metastasis and invasion of ESCC cells. Meanwhile, we also found that overexpression of SCARA5 caused changes in mitochondrial morphology, accumulation of intracellular reactive oxygen species and increased intracellular Fe
2+
in ESCC cells, which induced ferroptosis in ESCC cells. Mechanically, we validated that SCARA5 combined with ferritin light chain and increased intracellular Fe
2+
. As well as, overexpression
SCARA5
induced ferroptosis by increasing ferritin light chain in nude mice subcutaneous tumors and inhibited the growth of nude mice subcutaneous tumors.
Conclusion
Collectively, our findings demonstrated that
SCARA5
suppressed the proliferation and metastasis of ESCC by triggering ferroptosis through combining with ferritin light chain.
Journal Article