Synthesis and characterization of waste commercially available polyacrylonitrile fiber-based new composites for efficient removal of uranyl from U(VI)-CO3 solutions.

The existing species of uranium determines the design of novel sorbents towards uranium extraction from the natural waters. Herein, three composites based on waste commercially available polyacrylonitrile fiber (WPANF), namely WPANF/TiO2·xH2O, WPANF/CTAB-bentonite, and WPANF/NZVI, were first prepared and employed for the removal of U(VI) from the carbonate coexisted aqueous solutions. Among them, the WPANF/TiO2·xH2O exhibited the optimum sorption capacity of ~40.6 mg·g-1 (pH 8.0, C0 = 50 mg·L-1, and [CO3]Total = 2 mmol·L-1), which is significantly greater than the WPANF/CTAB-bentonite (~12.6 mg·g-1) and WPANF/NZVI (~10.3 mg·g-1). All sorption capacities decreased with the increases of initial pH, [NaCl], and [CO3]Total, due to the species transformation from UO2(CO3)22- and (UO2)2CO3(OH)3- to UO2(CO3)34- that enhanced the electrostatic repulsion and the competitive sorption. The XPS analysis and DFT calculations indicated that in the composites, WPANF was a role in strengthening the mechanical properties of composites rather than the main sorption sites for uranyl carbonates. The sorption mechanisms were mainly involved in -OH group coordination, Br- anions exchanges, and redox reactions. Desorption, reusability and U(VI) sorption test in the simulated seawater demonstrated that WPANF/TiO2·xH2O could be an alternative candidate for acquiring uranium resource. This work has screened the potential composites for U(VI) extraction from the natural waters, especially based on the practical U(VI) speciation, and provides a novel research approach for the removal of U(VI) towards U(VI)-CO3 systems.

Transient 40 °C-shock potentiates cytotoxic responses of Vδ2+ γδ T cell via HSP70 upregulation.

Vδ2+ γδ T cell, one of promising strategies for tumor immunotherapy, recognizes and kills cancer cells in a non-MHC dependent manner. Previously, we pioneeringly proved the clinical safety and efficacy of allogeneic Vδ2+ γδ T cells, in vitro expanded from healthy donors, in the treatment of late-stage cancer patients. Nevertheless, how to profoundly potentiate cytotoxic function of expanded Vδ2+ γδ T cells remains to be further explored. Here, we proposed that 40 °C-Shock could be a simple and reliable approach to in vitro boost the effector function. We found that 40 °C-shock could phosphorylate two MAPK proteins ERK and p38 through HSP70, which facilitated actyl-α-tubulin and actin augments and reorganization, elevated Ki-67 expression and cell surface adhesion, and promoted releases of cytokines IFN-γ, perforin and granzyme B, as well as downregulated LAG3 expression. We also observed 40 °C-shock induced elevations of mitochondrial metabolism. These altogether led to potentiated cytotoxic responses against cancer cells. This proof-of-concept work demonstrated that 40 °C-shock would be probably developed into an effective method to in vitro boost the cytotoxicity of Vδ2+ γδ T cell before applying it in immunotherapy, and provided scientific evidences for the view that fever can activate immune responses of innate immune cells.

Scutellarin inhibits caspase-11 activation and pyroptosis in macrophages via regulating PKA signaling.

Inflammatory caspase-11 senses and is activated by intracellular lipopolysaccharide (LPS) leading to pyroptosis that has critical role in defensing against bacterial infection, whereas its excess activation under pathogenic circumstances may cause various inflammatory diseases. However, there are few known drugs that can control caspase-11 activation. We report here that scutellarin, a flavonoid from Erigeron breviscapus, acted as an inhibitor for caspase-11 activation in macrophages. Scutellarin dose-dependently inhibited intracellular LPS-induced release of caspase-11p26 (indicative of caspase-11 activation) and generation of N-terminal fragment of gasdermin D (GSDMD-NT), leading to reduced pyroptosis. It also suppressed the activation of non-canonical nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome as evidenced by reduced apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and decreased interleukin-1 beta (IL-1ß) and caspase-1p10 secretion, whereas the NLRP3-specific inhibitor MCC950 only inhibited IL-1ß and caspase-1p10 release and ASC speck formation but not pyroptosis. Scutellarin also suppressed LPS-induced caspase-11 activation and pyroptosis in RAW 264.7 cells lacking ASC expression. Moreover, scutellarin treatment increased Ser/Thr phosphorylation of caspase-11 at protein kinase A (PKA)-specific sites, and its inhibitory action on caspase-11 activation was largely abrogated by PKA inhibitor H89 or by adenylyl cyclase inhibitor MDL12330A. Collectively, our data indicate that scutellarin inhibited caspase-11 activation and pyroptosis in macrophages at least partly via regulating the PKA signaling pathway.

Berberine augments hypertrophy of colonic patches in mice with intraperitoneal bacterial infection.

Colonic patches, the counterparts of Peyer's patches in the small intestine, are dynamically regulated lymphoid tissues in the colon that have an important role in defensing against microbial infections. Berberine is an isoquinoline alkaloid extracted from medicinal herbs including Rhizoma coptidis and has long been used for the treatment of infectious gastroenteritis, but its impact on the colonic lymphoid tissues (such as colonic patches) is unknown. In this study, we aimed to investigate whether berberine had any influences on the colonic patches in mice with bacterial infection. The results showed that oral berberine administration in bacterial infected mice substantially enhanced the hypertrophy of colonic patches, which usually possessed the features of two large B-cell follicles with a separate T-cell area. Moreover, the colonic patches displayed follicular dendritic cell networks within the B-cell follicles, indicative of mature colonic patches containing germinal centers. Concomitant with enlarged colonic patches, the cultured colon of infected mice treated with berberine secreted significantly higher levels of interleukin-1ß (IL-1ß), IL-6, TNF-α, and CCL-2, while NLRP3 inhibitor MMC950 or knockout of NLRP3 gene abrogated berberine-induced hypertrophy of colonic patches, suggesting the involvement of the NLRP3 signaling pathway in this process. Functionally, oral administration of berberine ameliorated liver inflammation and improved formed feces in the colon. Altogether, these results indicated that berberine was able to augment the hypertrophy of colonic patches in mice with bacterial infection probably through enhancing local inflammatory responses in the colon.

ATP induces caspase-3/gasdermin E-mediated pyroptosis in NLRP3 pathway-blocked murine macrophages.

ATP acts as a canonical activator to induce NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome activation in macrophages, leading to caspase-1/gasdermin D (GSDMD)-mediated pyroptosis. It remains unclear whether ATP can induce pyroptosis in macrophages when the NLRP3 pathway is blocked by pathogenic infection. In this study, we used cellular models to mimic such blockade of NLRP3 activation: bone marrow-derived macrophages (BMDMs) treated with NLRP3-specific inhibitor MCC950 and RAW264.7 cells deficient in ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain) expression. The results showed that ATP treatment induced lytic cell death morphologically resembling canonical pyroptosis in both MCC950-treated BMDMs and RAW264.7 cells, but did not cause the activation of caspase-1 (by detecting caspase-1p10 and mature interleukin-1ß) and cleavage of GSDMD. Instead, both apoptotic initiator (caspase-8 and -9) and executioner (caspase-3 and -7) caspases were evidently activated and gasdermin E (GSDME) was cleaved to generate its N-terminal fragment (GSDME-NT) which executes pyroptosis. The GSDME-NT production and lytic cell death induced by ATP were diminished by caspase-3 inhibitor. In BMDMs without MCC950 treatment, ATP induced the formation of ASC specks which were co-localized with caspase-8; with MCC950 treatment, however, ATP did not induced the formation of ASC specks. In RAW264.7 cells, knockdown of GSDME by small interfering RNA attenuated ATP-induced lytic cell death and HMGB1 release into culture supernatants. Collectively, our results indicate that ATP induces pyroptosis in macrophages through the caspase-3/GSDME axis when the canonical NLRP3 pathway is blocked, suggestive of an alternative mechanism for combating against pathogen evasion.