Mn2+ luminescence of Gd(Zn,Mg)B5O10 pentaborate under high pressure

The results of X-ray diffraction studies of the Gd(Mg_0.95-x,Zn_xMn_-0.05)B₅O₁₀ down-converting phosphor as a function of Mg-Zn composition are presented. The lattice parameters and unit cell volumes of GdMg_0.95-xZn_xMn_0.05B₅O₁₀ pentaborates are examined. The relationships between the structure and optical properties of these materials are explicated based on the results of theoretical calculations of the energy structure. The effect of pressure on the luminescence of Mn²⁺ in this system was studied up to ca. 32 GPa. The observed quenching of Mn²⁺ luminescence is due to the crossing of the emitting ⁴T_1g level with the non-emitting ²T_2g state. This crossing sets a long-wavelength limit on the possibility of observing the emission of Mn²⁺ ions, which is around 850 nm.

Label-Free Mass Spectrometry-Based Quantitative Proteomics Analysis of Serum Proteins During Early Pregnancy in Jennies (Equus asinus)

Early pregnancy in jennies is routinely determined by palpation per rectum or ultrasonography and also by detecting steroid hormone and chorionic gonadotropin levels in the blood, plasma, and serum. Herein we applied label-free mass spectrometry-based quantitative proteomics to identify serum proteins that were differentially expressed between early pregnant (day 45 after ovulation) and non-pregnant jennies. Bioinformatics analysis allowed illustration of pathways potentially involved in early pregnancy. We identified 295 proteins from a total of 2,569 peptides. Twenty-five proteins (22 upregulated and three downregulated) were significantly differentially expressed between the early pregnant and non-pregnant groups. The majority of the differentially expressed proteins were involved in defense response, early embryonic development, and hormone signaling pathways. Furthermore, functional protein analyses suggested that proteins were involved in binding, enzyme inhibitor activity, and enzyme regulator activity. Five serum proteins—granulin precursor/acrogranin, transgelin-2, fibronectin, fibrinogen-like 1, and thrombospondin 1—can be considered as novel, reliable candidates to detect pregnancy in jennies. To the best of our knowledge, this is the first study to use label-free mass spectrometry-based quantitative proteomics to analyze serum proteins during early pregnancy in jennies. Our results should facilitate the identification of valuable pregnancy diagnostic markers in early pregnant jennies.

Melatonin suppresses ER stress-dependent proapoptotic effects via AMPK in bone mesenchymal stem cells during mitochondrial oxidative damage

Background

Bone marrow mesenchymal stem cells (BMSCs) have been used as important cell-based tools for clinical applications. Oxidative stress-induced apoptosis causes a low survival rate after transplantation, and the underlying mechanisms remain unknown. The endoplasmic reticulum (ER) and mitochondria are vital organelles regulated by adenosine monophosphate (AMP)-activated protein kinase (AMPK), especially during oxidative stress injury. Melatonin exerts an antioxidant effect by scavenging free radicals. Here, we aimed to explore whether cytoprotective melatonin relieves ER stress-mediated mitochondrial dysfunction through AMPK in BMSCs after oxidative stress injury.

Methods

Mouse BMSCs were isolated and exposed to H₂O₂ in the absence or presence of melatonin. Thereafter, cell damage, oxidative stress levels, mitochondrial function, AMPK activity, ER stress-related proteins, and apoptotic markers were measured. Additionally, the involvement of AMPK and ER stress in the melatonin-mediated protection of BMSCs against H₂O₂-induced injury was investigated using pharmacologic agonists and inhibitors.

Results

Melatonin improved cell survival and restored mitochondrial function. Moreover, melatonin intimately regulated the phosphorylation of AMPK and molecules associated with ER stress pathways. AMPK activation and ER stress inhibition following melatonin administration improved the mitochondrial membrane potential (MMP), reduced mitochondria-initiated oxidative damage, and ultimately suppressed apoptotic signaling pathways in BMSCs. Cotreatment with N-acetyl-l-cysteine (NAC) significantly enhanced the antioxidant effect of melatonin. Importantly, pharmacological AMPK activation/ER stress inhibition promoted melatonin-induced cytoprotection, while pharmacological AMPK inactivation/ER stress induction conferred resistance to the effect of melatonin against H₂O₂ insult.

Conclusions

Our data also reveal a new, potentially therapeutic mechanism by which melatonin protects BMSCs from oxidative stress-mediated mitochondrial apoptosis, possibly by regulating the AMPK-ER stress pathway.

Melatonin suppresses ER stress-dependent proapoptotic effects via AMPK in bone mesenchymal stem cells during mitochondrial oxidative damage

BACKGROUND

Bone marrow mesenchymal stem cells (BMSCs) have been used as important cell-based tools for clinical applications. Oxidative stress-induced apoptosis causes a low survival rate after transplantation, and the underlying mechanisms remain unknown. The endoplasmic reticulum (ER) and mitochondria are vital organelles regulated by adenosine monophosphate (AMP)-activated protein kinase (AMPK), especially during oxidative stress injury. Melatonin exerts an antioxidant effect by scavenging free radicals. Here, we aimed to explore whether cytoprotective melatonin relieves ER stress-mediated mitochondrial dysfunction through AMPK in BMSCs after oxidative stress injury.

METHODS

Mouse BMSCs were isolated and exposed to H₂O₂ in the absence or presence of melatonin. Thereafter, cell damage, oxidative stress levels, mitochondrial function, AMPK activity, ER stress-related proteins, and apoptotic markers were measured. Additionally, the involvement of AMPK and ER stress in the melatonin-mediated protection of BMSCs against H₂O₂-induced injury was investigated using pharmacologic agonists and inhibitors.

RESULTS

Melatonin improved cell survival and restored mitochondrial function. Moreover, melatonin intimately regulated the phosphorylation of AMPK and molecules associated with ER stress pathways. AMPK activation and ER stress inhibition following melatonin administration improved the mitochondrial membrane potential (MMP), reduced mitochondria-initiated oxidative damage, and ultimately suppressed apoptotic signaling pathways in BMSCs. Cotreatment with N-acetyl-L-cysteine (NAC) significantly enhanced the antioxidant effect of melatonin. Importantly, pharmacological AMPK activation/ER stress inhibition promoted melatonin-induced cytoprotection, while pharmacological AMPK inactivation/ER stress induction conferred resistance to the effect of melatonin against H₂O₂ insult.

CONCLUSIONS

Our data also reveal a new, potentially therapeutic mechanism by which melatonin protects BMSCs from oxidative stress-mediated mitochondrial apoptosis, possibly by regulating the AMPK-ER stress pathway.

MiR-124 changes the sensitivity of lung cancer cells to cisplatin through targeting STAT3

OBJECTIVE

To investigate the role of micro ribonucleic acid (miR)-124 in drug resistance of non-small cell lung cancer (NSCLC), and to explore its underlying mechanism.

MATERIALS AND METHODS

The expression levels of miR-124 and signal transducer and activator of transcription 3 (STAT3) in maternal A549 cells and cisplatin-resistant A549/DDP cells were detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. A549 and A549/DDP cells were transfected with miR-124 mimics and miR-124 negative control (NC), respectively. Changes in the expression of STAT3 were detected via qRT-PCR and Western blotting. Meanwhile, the sensitivity of cells transfected with miR-124 mimics to cisplatin was detected via methyl thiazolyl tetrazolium (MTT) assay. The effects of miR-124 on the apoptosis, invasion and metastasis of cells were detected via flow cytometry, wound healing assay and transwell assay, respectively. Moreover, wild-type and mutant-type STAT3 luciferase reporter plasmids were co-transfected with miR-124 mimics or miR-124 NC. Luciferase activity was analyzed using the dual-luciferase reporter gene assay.

RESULTS

QRT-PCR and Western blotting revealed that the expression level of miR-124 in A549/DDP cells was significantly lower than that of A549 cells. However, the expression level of STAT3 in A549/DDP cells was significantly higher than that of A549 cells. Overexpression of miR-124 remarkably reduced the expression level of STAT3 in A549/DDP cells, increased the sensitivity of A549/DDP cells to cisplatin, and inhibited the invasion and metastasis capacities of cells. In addition, luciferase reporter gene assay demonstrated that miR-124 could negatively regulate the protein expression of STAT3 by binding to its 3'-untranslated region (UTR).

CONCLUSIONS

MiR-124 regulates the sensitivity of NSCLC to cisplatin. Moreover, it inhibits the invasion and metastasis capacities through targeting STAT3, which can serve as a therapeutic target for cisplatin-based chemotherapy resistance of NSCLC.

Characterizing the Serum Proteome of Donkeys (Equus asinus)

Serum and plasma are commonly used in clinical practice considering the widely accepted fact that the "normal" protein expression pattern of a healthy animal changes under disease conditions. We herein used a label-free mass spectrometry-based quantitative proteomics approach to characterize the serum proteome of donkeys. A total of 277 unique proteins were identified from 2,388 unique peptides. Gene ontology analyses showed that the most frequent processes were related to metabolic activities and biological regulation, response to stimulus, and immune system processes. The main annotated areas of origin were the extracellular region, extracellular region part, and organelle, and their molecular functions included binding, catalytic activity, and molecular function regulator. Analyses using the Clusters of Orthologous Groups for Eukaryotic Complete Genomes database indicated that the identified proteins could be categorized into three main groups: signal transduction mechanisms, amino acid transport and metabolism, and defense mechanisms. Most of the unique proteins were associated with the complement and coagulation cascades, and they participated in several disease-related metabolic pathways. Our results should be crucial for further analyses of changes in different physiological and pathophysiological conditions in donkeys.

Design of a novel bimodal cavity

Here, we introduce and analyze a novel concept of using one single cavity to support dual modes instead of using separate cavities. One advantage of using a dual-mode cavity is that only one cavity needs to be manufactured, which is space-saving and obviously economic. Apart from this, by operating both the fundamental mode and the certain harmonic mode simultaneously in one single cavity, bunch lengthening during the acceleration process could be linearly achieved, providing great potential in improving the beam brightness in linacs, storage rings, and other accelerating structures. Through the detailed design study, a structure combining the fundamental and the chosen second harmonic modes is characterized. The RF performance of the designed bimodal cavity is deeply analyzed, and it could be put into actual use for different goals to improve either the beam dynamic characteristics or the compactness of the certain system.

[Efficacy comparison between robot-assisted and laparoscopic surgery for mid-low rectal cancer: a prospective randomized controlled trial]

Objective: To compare the short- and long-term outcomes of robot-assisted and laparoscopic radical resection for mid-low rectal cancer. Methods: A prospective randomized controlled trial was conducted. A total of 130 patients with mid-low rectal cancer (inclusion criteria: age > 18 or ≤80 years old; pathological diagnosis of rectal adenocarcinoma by colonoscopy; distance from tumor to the anal verge ≤12 cm; no distant metastasis; cT1-3N0-1 or ycT1-3 after neoadjuvant radiotherapy and chemotherapy; suitable for laparoscopic and robotic surgery) at the Department of Colorectal Surgery of the First Affiliated Hospital of Nanchang University from October 2016 to September 2018 were prospectively enrolled. According to computer-generated random number method, patients were randomly divided into the robot group (n=66) and laparoscopy group (n=64), and underwent robot-assisted surgery or laparoscopic surgery respectively. Clinicopathological data of all the patients were collected and analyzed. The demographic parameters, short- and long-term outcomes were compared between two groups. Results: One patient in robot group whose postoperative sample was diagnosed as rectal adenoma by pathology was excluded. There were no statistically significant differences in age, sex, BMI, ASA classification, distance from tumor to the anal verge, serum CEA level, CA199 level between two groups (all P>0.05). Operations were successfully performed in all the patients without conversion to open operation. Robotic surgery was found to be associated with less intraoperative blood loss than laparoscopic surgery [(73.4±49.7) ml vs. (119.1±65.7) ml, t=-4.461, P<0.001], while there were no statistically significant differences in surgical procedures, operation time, time to first flatus, time to first liquid intake, time to removal of catheter or postoperative hospital stay between two groups (all P>0.05). Besides, there was no significant difference in the morbidity of postoperative complication between two groups [10.8% (7/65) vs. 12.5 (8/64), χ(2)=4.342, P=0.720]. The median number of harvested lymph node in the robot group and the laparoscopy group was 15.7±6.2 and 13.8±6.1 (t=1.724, P=0.087). There were no significant differences between two groups in tumor sample length, distance between proximal and distal resection margin, integrity grade of TME specimen, number of positive lymph nodes, postoperative pathological stage and tumor differentiation (all P>0.05). The distal resection margin of samples in two groups was all negative. One case in the robot group was found to have positive circumferential resection margin. The median follow up was 24 (9 to 31) months. In the robot group and the laparoscopy group, the 2-year overall survival rate was 95.4% and 90.6% respectively; the 2-year disease-free survival rate was 90.8% and 85.9% respectively, whose differences were not significant (both P>0.05). Conclusion: Robot-assisted radical resection for mid-low rectal cancer can achieve similar short-term and long-term outcomes of laparoscopic resection, while robot-assisted surgery can decrease blood loss during operation, leading to more precise practice in minimally invasive surgery.