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This paper aimed to develop a novel dura mater substitute made from swim bladders.The swim bladders were decellularized by diverse methods. The physical structure, residual DNA amount, mechanical properties and hemolysis rate were tested. The in vitro mouse embryonic fibroblast cells (MEFs) co-culture and in vivo dural repair surgery were performed to evaluate the biocompatibility of acellular swim bladder (ASBs).The characteristics of different ASBs were evaluated, and the materials prepared via 'freezing-thawing and DNase-I' method showed the most appropriate features as dura mater substitute. The loosen fiber layer structure and three-dimensional porous structure were formed after decellularization. The residual DNA content was low (9.2 ± 2.0 ng/mg) and the mechanical properties could meet the clinical requirement (the maximum tensile strength was 34.77 ± 4.28 N and the maximum stitch tear strength was 7.15 ± 1.84 N). The hemolysis rate was up to 2.8 ± 0.15%. In the MEFs co-culture test, ASBs could support the adhesion, migration and proliferation of cells. The dural repair experiment demonstrated ASBs could prevent the leak of cerebrospinal fluid, and the materials were gradually replaced by autologous connective tissue. The novel dura mater substitute improved dura repair and regeneration without causing adhesion or severe inflammation.The ASBs prepared via 'freezing-thawing and DNase-I' method had the ideal physical and biological properties as a dura mater substitute for clinical application.

Acquired resistance to tyrosine kinase inhibitors (TKIs) is the major obstacle to improve clinical efficacy in cancer patients. The epithelial-stromal interaction in tumor microenvironment influences cancer drug response to TKIs. Anlotinib is a novel oral multi-targeted TKI, and has recently been proven to be effective and safe for several tumors. However, if and how the epithelial-stromal interaction in tumor microenvironment affects anlotinib response in gastric cancer (GC) is not known. In this study, we found that anlotinib inhibited GC cells growth by inducing GC cells apoptosis and G2/M phase arrest in a dose- and time-dependent manner. Reactive oxygen species (ROS) mediated anlotinib-induced apoptosis in GC cells, while cancer-associated fibroblasts (CAFs) significantly suppressed anlotinib-induced apoptosis and ROS in GC cells. Increased BDNF that was derived from CAFs activated TrkB-Nrf2 signaling in GC cells, and reduced GC cells response to anlotinib. We identified secreted lactate from GC cells as the key molecule instructing CAFs to produce BDNF in a NF-κB-dependent manner. Additionally, functional targeting BDNF-TrkB pathway with neutralizing antibodies against BDNF and TrkB increased the sensitivity of GC cells towards anlotinib in human patient-derived organoid (PDO) model. Taken together, these results characterize a critical role of the epithelial-stroma interaction mediated by the lactate/BDNF/TrkB signaling in GC anlotinib resistance, and provide a novel option to overcome drug resistance., Graphical abstract Image 1, Highlights • Anlotinib induced apoptosis through ROS accumulation. • CAFs drive acquired resistance of GC to anlotinib. • TrkB activation by CAFs-derived BDNF confer resistance to anlotinib-induced ROS. • GC cells-secreted lactate induced BDNF expression of CAFs through activating NF-κB. • Blocking BDNF and TrkB reversed CAFs-induced acquired resistance to anlotinib.

Adaptation to changes in extracellular tonicity is essential for cell survival. However, severe or chronic hyperosmotic stress induces apoptosis, which involves cytochrome c (Cyt c) release from mitochondria and subsequent apoptosome formation. Here, we show that angiogenin-induced accumulation of tRNA halves (or tiRNAs) is accompanied by increased survival in hyperosmotically stressed mouse embryonic fibroblasts. Treatment of cells with angiogenin inhibits stress-induced formation of the apoptosome and increases the interaction of small RNAs with released Cyt c in a ribonucleoprotein (Cyt c-RNP) complex. Next-generation sequencing of RNA isolated from the Cyt c-RNP complex reveals that 20 tiRNAs are highly enriched in the Cyt c-RNP complex. Preferred components of this complex are 5′ and 3′ tiRNAs of specific isodecoders within a family of isoacceptors. We also demonstrate that Cyt c binds tiRNAs in vitro, and the pool of Cyt c-interacting RNAs binds tighter than individual tiRNAs. Finally, we show that angiogenin treatment of primary cortical neurons exposed to hyperosmotic stress also decreases apoptosis. Our findings reveal a connection between angiogenin-generated tiRNAs and cell survival in response to hyperosmotic stress and suggest a novel cellular complex involving Cyt c and tiRNAs that inhibits apoptosome formation and activity.