Endoglin Is Essential for the Maintenance of Self-Renewal and Chemoresistance in Renal Cancer Stem Cells.

Renal cell carcinoma (RCC) is a deadly malignancy due to its tendency to metastasize and resistance to chemotherapy. Stem-like tumor cells often confer these aggressive behaviors. We discovered an endoglin (CD105)-expressing subpopulation in human RCC xenografts and patient samples with a greater capability to form spheres in vitro and tumors in mice at low dilutions than parental cells. Knockdown of CD105 by short hairpin RNA and CRISPR/cas9 reduced stemness markers and sphere-formation ability while accelerating senescence in vitro. Importantly, downregulation of CD105 significantly decreased the tumorigenicity and gemcitabine resistance. This loss of stem-like properties can be rescued by CDA, MYC, or NANOG, and CDA might act as a demethylase maintaining MYC and NANOG. In this study, we showed that Endoglin (CD105) expression not only demarcates a cancer stem cell subpopulation but also confers self-renewal ability and contributes to chemoresistance in RCC

Regulating Cytoplasmic Calcium Homeostasis Can Reduce Aluminum Toxicity in Yeast

Our previous study suggested that increased cytoplasmic calcium (Ca) signals may mediate aluminum (Al) toxicity in yeast (Saccharomyces cerevisiae). In this report, we found that a yeast mutant, pmc1, lacking the vacuolar calcium ion (Ca2+) pump Ca2+-ATPase (Pmc1p), was more sensitive to Al treatment than the wild-type strain. Overexpression of either PMC1 or an anti-apoptotic factor, such as Bcl-2, Ced-9 or PpBI-1, decreased cytoplasmic Ca2+ levels and rescued yeast from Al sensitivity in both the wild-type and pmc1 mutant. Moreover, pretreatment with the Ca2+ chelator BAPTA-AM sustained cytoplasmic Ca2+ at low levels in the presence of Al, effectively making the cells more tolerant to Al exposure. Quantitative RT-PCR revealed that the expression of calmodulin (CaM) and phospholipase C (PLC), which are in the Ca2+ signaling pathway, was down-regulated under Al stress. This effect was largely counteracted when cells overexpressed anti-apoptotic Ced-9 or were pretreated with BAPTA-AM. Taken together, our results suggest that the negative regulation of Al-induced cytoplasmic Ca signaling is a novel mechanism underlying internal resistance to Al toxicity

A Natural Occurring Mouse Model with Adgrv1 Mutation of Usher Syndrome 2C and Characterization of its Recombinant Inbred Strains

Background/Aims: Our laboratory discovered a Kunming mouse with enormous electroretinogram (ERG) defects. Its auditory brainstem response (ABR) threshold was significantly elevated and closely resembled the features of Usher syndrome (USH). This study sought to cross these USH-like mice (named KMush/ush mice) with CBA/CaJ mice to establish recombinant inbred strains and identify their phenotypes and genotypes. Methods: KMush/ush mice were crossed with CBA/CaJ mice to establish inbred strains by sibling mating. ERG, ABR, ocular fundus morphology, histological examinations of the retina and inner ear, quantitative real-time polymerase chain reaction, western blotting, and exon sequencing were performed to assess the phenotypes and genotypes of the offspring strains. Results: The F1 hybrids from crossing KMush/ush and CBA/CaJ mice had normal ERG and ABR responses. The F2 offspring from intercrossing the F1 mice showed a segregation of the retinitis pigmentosa (RP) and hearing loss phenotypes. The CBA-1ush/ush mice had an RP phenotype that was characterized by a vanished ERG waveform and loss of the outer nuclear layer. Their Pde6b gene had a nonsense mutation that resulted in the failure of protein production in western blotting. However, the ABR threshold of this strain of mice was normal. The CBA-2ush/ush mice had normal retinal function and architecture. Their ABR threshold was increased, with a dramatic degeneration of the stereocilia bundles in the outer hair cells of the inner ear. Whole exome sequencing and exon sequencing revealed a deletion of one base pair in exon 31 of the Adgrv1 gene, which would result in the premature termination of protein encoding. The level of Adgrv1 mRNA was reduced in the CBA-2ush/ush mice. The CBA-3ush/ush mice had phenotypes of RP, elevated ABR threshold, and degeneration of the stereocilia bundles in the outer hair cells. They were closely associated with the nonsense mutations of Pde6b and Adgrv1, respectively. Conclusion: We isolated a mouse strain with hearing loss from inbred mice with retinal degeneration and established it as a recombinant inbred strain with a spontaneous mutation in Adgrv1, the human Usher syndrome 2C gene. The retinal degeneration was cause by a mutation in Pde6b, while the hearing loss was caused by a mutation in Adgrv1

Design and engineering of 3D collagen-fibronectin scaffolds for wound healing applications

The extracellular matrix (ECM) plays an important role in many crucial cellular processes such as gene expression, cancer progression and cell differentiation. Cells are able to sense the mechanical properties of their extracellular environment and adjust their gene expression accordingly. The ECM regulates numerous cell behaviors including cells adhesion, spreading, migration, proliferation, and death. Fibronectin, a key glycoprotein of the ECM, is critical in the early wound healing process, as it can stop bleeding and protect the tissue, facilitate cell motility and proliferation, and guide the remodeling of new ECM. Subsequently, collagen is also deposited at the wound. The resulting mature collagen-fibronectin ECM keeps the wound sterile and induces the wound closure. Three different systems of collagen-fibronectin three-dimensional (3D) scaffolds were developed for this thesis. First, a collagen porous scaffold was originally fabricated using ice templating techniques and then coated with a layer of fibronectin, whose conformation was controlled via incubation temperature and monitored using Fӧrster resonance energy transfer (FRET) spectroscopy. This platform was next utilized to investigate the effect of ECM structure and conformation on cellular invasion and viability. Second, fibronectin was assembled into 3D fibrillar matrix within the above-mentioned porous collagen scaffold via shearing methods, which provides a promising platform for further investigation of cell-ECM interactions. Third, collagen fibrillar scaffolds with tunable microarchitecture and cell content were generated via warm/cold casting techniques, which resulted in ECM platforms that closely mimic the wound physiological environment. Collectively, our study suggests that by tuning collagen (porous vs. fibrillar) structure and fibronectin molecular conformation, we were able to control cell behaviors including cell adhesion, migration and proliferation, and thus, potentially facilitate the wound healing process. These 3D ECM-mimicking platforms offer precise control of protein microarchitecture and conformation over large volumes, i.e., for long-term cell culture, and therefore have potential applications in tissue engineering as well as regenerative medicine

The Influence of the Tri-reference Points on Fairness and Satisfaction Perception

We examined the influence of three reference points (minimum requirements [MR], the status quo [SQ], and goal [G]) proposed by the tri-reference point (TRP) theory on fairness and satisfaction perceptions of pay in three laboratory experiments. To test the effects, we manipulated these three reference points both implicitly (Experiment 1) and explicitly (Experiments 2 and 3). We also provided the information of the salary offered to a peer person that was lower than, equal to, or higher than the salary offer to the participant. As hypothesized, the results demonstrated the important role of these reference points in judging the fairness of and satisfaction with pay when they were explicitly set (an interaction between reference points and social comparison in Experiments 2 and 3, but not in Experiment 1). Participants altered their judgments when the salary was in different regions. When the salary was below MR, participants perceived very low fairness and satisfaction, even when the offer was equal to/exceeded others. When the salary was above G, participants perceived much higher fairness and satisfaction, even with disadvantageous inequality. Participants were more impacted when they were explicitly instructed of the reference points (Experiments 2 and 3) than when they were not (Experiment 1). Moreover, MR appeared to be the most important, followed by G. A Salary below MR was judged as very unacceptable, with very low fairness and satisfaction ratings

RESEARCH ON RADIAL FAILURE CRITERION AND LIMIT SPEED FOR CIRCLIPS

Circlip is an important fastener, its service performance at high speed directly affects the reliability of mechanical equipment. By analyzing the centrifugal force distribution of unequal diameter circlips, simulating and testing the initial contact between circlip and shaft, the results show that the maximum centrifugal force occurs in the thickest position of the circlip, the contact state can be simplified to be three point contact, then proposing the detaching point assumption and the radial failure criterion. By using German Seeger circlip models, simulating the circlip radial displacement in high speed,according to the German circlip standard DIN471, the results show that the relative error between circlip limit speed and the DIN471 standard is less than 8% based on the detaching point assumption, which verifies the validity of the radial failure criterion. This paper has reference significance for the development of the new national circlip standard GB/T 894-2017

Clinical Therapeutic Effects of Aspirin in Combination with Fufang Danshen Diwan, a Traditional Chinese Medicine Formula, on Coronary Heart Disease: A Systematic Review and Meta-Analysis

Background/Aims: Coronary heart disease is characterized by vascular stenosis or occlusion resulting in myocardial ischemia, hypoxia and necrosis. In China, the combination of aspirin and Fufang Danshen Diwan (FDD), a traditional Chinese medicine formula, has been suggested in the treatment of coronary heart disease. There have been several studies comparing the effectiveness of aspirin alone and in combination with FDD to treat coronary artery disease; however, it remains unclear whether combined aspirin therapy is superior. This study was thus designed to clarify this issue through a systematic review and meta-analysis. Methods: Databases including PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) database, Wanfang Data and VIP Information were searched. Papers were reviewed systematically by two researchers and analyzed using Cochrane software Revman 5.1. Results: Fourteen randomized controlled trials enrolling 1367 subjects were included. Meta-analyses revealed that aspirin in combination with FDD was significantly more effective at alleviating angina pectoris and improving electrocardiogram (ECG) results relative to aspirin therapy alone, reflected by the summary effects for the clinical markedly effective (OR = 2.45; 95% CI 1.95-3.08) and the total effective (OR = 3.92; 95% CI 2.87-5.36) rates. In addition, combined aspirin and FDD was significantly more efficacious than aspirin monotherapy at improving blood lipid levels, as indicated by the following outcomes: 1) reduction of TC level (SMD −1.12; 95% CI −1.49 to −0.76); 2) reduction of TG level (SMD −0.94; 95% CI −1.15 to -0.74); 3) reduction of LDL level (SMD -0.68; 95% CI -0.88 to -0.48); and 4) improvement of HDL level (SMD 0.52; 95% CI 0.04 to 0.99 ). No serious adverse events were reported in any of the included trials. Conclusion: The present meta-analysis demonstrated that aspirin in combination with FDD was more effective than aspirin alone for treating coronary heart disease. More full-scale randomized clinical trials with reliable designs are recommended to further evaluate the clinical benefits and long-term effectiveness of FDD for the treatment of coronary heart disease

A Hybrid Lumped Parameters/Finite Element/Boundary Element Model to Predict the Vibroacoustic Characteristics of an Axial Piston Pump

Low noise axial piston pumps become the rapid increasing demand in modern hydraulic fluid power systems. This paper proposes a systematic approach to simulate the vibroacoustic characteristics of an axial piston pump using a hybrid lumped parameters/finite element/boundary element (LP/FE/BE) model, and large amount of experimental work was performed to validate the model. The LP model was developed to calculate the excitation forces and was validated by a comparison of outlet flow ripples. The FE model was developed to calculate the vibration of the pump, in which the modeling of main friction pairs using different spring elements was presented in detail, and the FE model was validated using experimental modal analysis and measured vibrations. The BE model was used to calculate the noise emitted from the pump, and a measurement of sound pressure level at representative field points in a hemianechoic chamber was conducted to validate the BE model. Comparisons between the simulated and measured results show that the developed LP/FE/BE model is effective in capturing the vibroacoustic characteristics of the pump. The presented approach can be extended to other types of fluid power components and contributes to the development of quieter fluid power systems