Mechanically induced pyroptosis enhances cardiosphere oxidative stress resistance and metabolism for myocardial infarction therapy.

Current approaches in myocardial infarction treatment are limited by low cellular oxidative stress resistance, reducing the long-term survival of therapeutic cells. Here we develop a liquid-crystal substrate with unique surface properties and mechanical responsiveness to produce size-controllable cardiospheres that undergo pyroptosis to improve cellular bioactivities and resistance to oxidative stress. We perform RNA sequencing and study cell metabolism to reveal increased metabolic levels and improved mitochondrial function in the preconditioned cardiospheres. We test therapeutic outcomes in a rat model of myocardial infarction to show that cardiospheres improve long-term cardiac function, promote angiogenesis and reduce cardiac remodeling during the 3-month observation. Overall, this study presents a promising and effective system for preparing a large quantity of functional cardiospheres, showcasing potential for clinical application.

Reconstructing auto tissue engineering lamellar cornea with aspartic acid modified acellular porcine corneal stroma and preconditioned limbal stem cell for corneal regeneration.

Tissue engineering cornea has shown great clinical potential for cornea reconstruction, but efficient recovery of natural structure and physiological function remains great challenges. In this study, the acellular porcine corneal stroma (APCS) was prepared by a phospholipase A2 decellularization method and further crosslinked with aspartic acid (Asp). The modified APCS-Asp scaffold showed significant increase of hydration degree, ultrastructure regularity, corneal viscoelasticity and anti-degradation ability compared to APCS. Autologous rabbit limbal tissue was pre-treated by tumor necrosis factor-alpha (TNF-α) and collagenase IV, and the pretreated primary limbal stem cells (LSCs) were cultured with embryonic stem cells conditioned medium (ESCM), and LSCs showed 3D cell sphere structure and improved stem cell properties compared to the control group. The auto-tissue engineering lamellar cornea (ATELC) was quickly reconstructed by using peptide hydrogel with a dynamic culture system. With intact and functional epithelial cell layer, the reconstructed ATELC quickly recovered natural optical characteristics 1 week post transplantation in the rabbit lamellar keratoplasty model and satisfying neural regrowth as well as favorable stromal repopulation were observed in the transplanted eyes in the 6 months following up post-surgery. In summary, this study provides a comprehensive optimized reconstruction strategy for ATELC, which maybe similar medical application to natural cornea.

Establishment and characterization of a highly metastatic human osteosarcoma cell line from osteosarcoma lung metastases.

OS (Osteosarcoma) is the most common malignant tumor in adolescents, and lung metastasis limits its therapeutic outcome. The present study aimed to establish a highly metastatic human OS cell line directly from lung metastases and characterize its biological functions. In this study, epithelioid tumor cells with large nucleo-cytoplasmic ratio and abundant organelles were obtained by the tissue mass adherent and repeated digestion adherent method and named ZOSL-1 cells. ZOSL-1 cells had the potential to proliferate in vitro with a doubling time of 39.28 ± 3.04 h and migrate with or without a matrix. ZOSL-1 cells were tumorigenic in vivo, and had the ability to develop lung metastasis after intratibial injection. ZOSL-1 cells expressed the osteogenic-related genes osteocalcin and osteopontin. In addition, the expression of ZOSL-1 in Fas cell surface death receptor (FAS), CD44 molecule (CD44), GNAS complex locus (GNAS), scavenger receptor class B member 1 (SCARB1), C-X-C motif chemokine receptor 4 (CXCR4), cadherin 11 (CDH11), neurofibromin 2 (NF2) and ezrin (EZR) genes may be related to its transfer efficiency. Taken together, these results indicated the high metastatic capability and important biological functions of ZOSL-1 cells. ZOSL-1 establishment provided a relevant model for the study of osteosarcoma lung metastasis.

Radioprotective Effects on Late Third-Instar Bactrocera dorsalis (Diptera: Tephritidae) Larvae in Low-Oxygen Atmospheres.

Ionizing radiation creates free radicals, the effect of which is enhanced by the presence of oxygen; a low oxygen level produces radioprotective effects for insects compared with irradiation in ambient air. Modified (controlled) atmosphere packaging is used for maintaining quality and shelf-life extension; therefore, treatment efficacy may be affected, and there is a need to determine the critical O2 levels that may cause radioprotective effects. Late third-instar Bactrocera dorsalis (Hendel) larvae were irradiated in bags filled with ambient or low-oxygen air (0%, 2%, 4%, 6%, 8% O2) and were exposed to radiation doses of 8 to 64 Gy with intervals of 8 Gy. Efficacy was measured by the prevention of adult emergence. Dose-response data on mortality (failure of adult emergence) were analyzed via two-way ANOVA (analysis of variance), ANCOVA (analysis of covariance), and probit regression. The difference in radiotolerance was only significant in 0% O2 atmospheres through two-way ANOVA; therefore, the 95% confidence limits (CLs) of lethal dose ratios at LD99 were used to determine significant differences between treatments at different O2 levels. The differences in radiotolerance were significant in 0% and 2% O2 but insignificant in 4%, 6%, and 8% O2 environments when compared with radiation in ambient air. The critical threshold of radioprotective effects for late third-instar B. dorsalis larvae is an O2 level of ≥4% and <6%, but a maximum radiation dose of 14 Gy can compensate for this effect during phytosanitary irradiation treatment.

Seasonal variations in body melanism and size of the wolf spider Pardosa astrigera (Araneae: Lycosidae).

Variations in species morphology and life-history traits strongly correlate with geographic and climatic characteristics. Most studies on morphological variations in animals focus on ectotherms distributed on a large geographic scale across latitudinal and/or altitudinal gradient. However, the morphological variations of spiders living in the same habitats across different seasons have not been reported. In this study, we used the wolf spider, Pardosa astrigera, as a model to determine seasonal differences in adult body size, melanism, fecundity, and egg diameter both in the overwintering and the first generation for 2010 and 2016. The results showed that in 2010, both females and males of the overwintering generation were significantly darker than the first generation. Moreover, the overwintering females were markedly larger and produced more and bigger eggs than the first generation in both 2010 and 2016. Considering the overwintering P. astrigera experiencing low temperature and/or desiccation stress, these results suggest that substantially darker and larger body of the overwintering generation is adaptive to adverse conditions.

Preparation of high bioactivity multilayered bone-marrow mesenchymal stem cell sheets for myocardial infarction using a 3D-dynamic system.

Cell sheet techniques offer a promising future for myocardial infarction (MI) therapy; however, insufficient nutrition supply remains the major limitation in maintaining stem cell bioactivity in vitro. In order to enhance cell sheet mechanical strength and bioactivity, a decellularized porcine pericardium (DPP) scaffold was prepared by the phospholipase A2 method, and aspartic acid was used as a spacer arm to improve the vascular endothelial growth factor crosslink efficiency on the DPP scaffold. Based on this scaffold, multilayered bone marrow mesenchymal stem cell sheets were rapidly constructed, using RAD16-I peptide hydrogel as a temporary 3D scaffold, and cell sheets were cultured in either the 3D-dynamic system (DCcs) or the traditional static condition (SCcs). The multilayered structure, stem cell bioactivity, and ultrastructure of DCcs and SCcs were assessed. The DCcs exhibited lower apoptosis, lower differentiation, and an improved paracrine effect after a 48 h culture in vitro compared to the SCcs. Four groups were set to evaluate the cell sheet effect in rat MI model: sham group, MI control group, DCcs group, and SCcs group. The DCcs group improved cardiac function and decreased the infarcted area compared to the MI control group, while no significant improvements were observed in the SCcs group. Improved cell survival, angiogenesis, and Sca-1+ cell and c-kit+ cell amounts were observed in the DCcs group. In conclusion, the DCcs maintained higher stem cell bioactivity by using the 3D-dynamic system to provide sufficient nutrition, and transplanting DCcs significantly improved the cardiac function and angiogenesis. STATEMENT OF SIGNIFICANCE: This study provides an efficient method to prepare vascular endothelial growth factor covalent decellularized pericardium scaffold with aspartic acid, and a multilayered bone marrow mesenchymal stem cell (BMSC) sheet is constructed on it using a 3D-dynamic system. The dynamic nutrition supply showed a significant benefit on BMSC bioactivity in vitro, including decreasing cell apoptosis, reducing stem cell differentiation, and improving growth factor secretion. These favorable bioactivity improved BMSC survival, angiogenesis, and cardiac function of the infarcted myocardium. The study highlights the importance of dynamic nutrition supply on maintaining stem cell bioactivity within cell sheet, and it stresses the necessity and significance of setting a standard for assessing cell sheet products before transplantation in the future application.

Mechano-regulatory cellular behaviors of NIH/3T3 in response to the storage modulus of liquid crystalline substrates.

The extent of substrate stiffness has been shown to be predominant in regulating cellular behaviors. Previous studies have used matrices such as elastomers or hydrogels to understand cell behavior. Herein, liquid crystalline matrices that resemble movable morphology of biomembrane and viscoelasticity were fabricated with tunable storage modulus for the evaluation of the modulus-driven cell behaviors. Our results demonstrated that NIH/3T3 cells showed a hypersensitive response to the storage modulus of liquid crystalline substrates by the alteration in attachment, spreading, proliferation and viability, polarization, cell cycle and apoptosis, and activity of mechano-transduction-related signal molecules including FAK, paxillin and ERK. The octyl hydroxypropyl cellulose substrates (OPC-1-5) with intermediate storage modulus of 12,312Pa and 7228Pa (OPC-2 and OPC-3 respectively) could provide more beneficial adhesion conditions leading to a larger spreading area, more elongated morphology and higher proliferation rates possibly through paxillin-ERK pathway, whereas the substrates with the highest or lowest storage modulus (16,723Pa, OPC-1; and 41Pa, OPC-5, respectively) appeared unfavorable for cell growth. Our study provides insights into the mechanism of modulus-driven cellular behaviors for better design of bioengineered cell substrates.

Improving blood-compatibility via surface heparin-immobilization based on a liquid crystalline matrix.

Blood compatibility is of considerable importance in developing medical materials and devices that are in contact with blood. In this work, we successfully developed a novel liquid crystalline heparin-immobilized material (Hep-OPPC) by two-step modification for further improvement of hydrophilicity and hemocompatibility of the liquid crystalline hydroxypropyl cellulose ester (OPCL). The results showed that Hep-immobilization on the OPCL led to dramatic changes in the surface morphology and crystallinity, whereas, the Hep-OPPCs also maintained the liquid crystalline feature at room temperature after heparinization. Furthermore, the hemocompatibility of the Hep-OPPCs was markedly enhanced at low levels of hemolysis assay (HR) with unimpaired erythrocytomorphology, significantly lower concentrations of C3a in blood plasma and remarkable increases in plasma re-calcification time (PRT). This suggests that the heparinized surface could restrict the transformation of fibrinogen with less activation of the intrinsic coagulation system. Moreover, the activated partial thromboplastin time (APTT) and prothrombin time (PT) values of the Hep-OPPCs with low heparin density could also be prolonged in this study suggesting that the liquid crystal feature of the matrix might be blocking the clotting factors. We concluded that the heparin-immobilized liquid crystalline material has the potential to be used in blood-contact materials.

Genetic Record for a Recent Invasion of Phenacoccus solenopsis (Hemiptera: Pseudococcidae) in Asia.

The cotton mealybug Phenacoccus solenopsis Tinsley is an emerging invasive insect pest. Since its first report as a pest in the United States in 1991, it has invaded and colonized more than 23 countries over the past century. It was first recorded from Pakistan in 2006 and from China in 2008. In this study, we performed field surveys from 2010 to 2012 and obtained mtCOI sequences from specimens across China and Pakistan, then compared them with already available mtCOI sequences from additional Asian and North American countries. Our genetic analysis provides evidence that P. solenopsis should be classified into two groups, one of which is found only in the United States, and the other found only in Asia. The Asian group contains nine unique haplotypes, two of which have invaded and spread across China, Pakistan, India, and Vietnam over the last 4-6 yr. Our genetic analysis also indicates that P. solenopsis has a close relationship with the parasitoid wasp Aenasius bambawalei Hayat, providing preliminary evidence of a congruent spread of this mealybug and its parasitoids across China.