Inhibition of GSDMD-mediated pyroptosis triggered by Trichinella spiralis intervention contributes to the alleviation of DSS-induced ulcerative colitis in mice.

BACKGROUND: Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is increasing worldwide. Although there is currently no completely curative treatment, helminthic therapy shows certain therapeutic potential for UC. Many studies have found that Trichinella spiralis (T.s) has a protective effect on UC, but the specific mechanism is still unclear. METHODS: Balb/c mice drank dextran sulfate sodium (DSS) to induce acute colitis and then were treated with T.s. In vitro experiments, the LPS combination with ATP was used to induce the pyroptosis model, followed by intervention with crude protein from T.s (T.s cp). Additionally, the pyroptosis agonist of NSC or the pyroptosis inhibitor vx-765 was added to intervene to explore the role of pyroptosis in DSS-induced acute colitis. The degree of pyroptosis was evaluated by western blot, qPCR and IHC, etc., in vivo and in vitro. RESULTS: T.s intervention significantly inhibited NLRP3 inflammasome activation and GSDMD-mediated pyroptosis by downregulating the expression of pyroptosis-related signatures in vitro (cellular inflammatory model) and in vivo (DSS-induced UC mice model). Furthermore, blockade of GSDMD-mediated pyroptosis by the caspase-1 inhibitor vx-765 has a similar therapeutic effect on DSS-induced UC mice with T.s intervention, thus indicating that T.s intervention alleviated DSS-induced UC in mice by inhibiting GSDMD-mediated pyroptosis. CONCLUSION: This study showed that T.s could alleviate the pathological severity UC via GSDMD-mediated pyroptosis, and it provides new insight into the mechanistic study and application of helminths in treating colitis.

Improving the growth of Rubrivivax gelatinosus cultivated in sewage environment.

Rubrivivax gelatinosus cultivated in wastewater environment can combine the biomass resource recycling for generating chemicals with sewage purification. However, low biomass accumulation restricts the exertion of this advantage. Thus, this paper investigated Fe(3+) advancement for biomass production in starch wastewater under light-anaerobic condition. Results showed that addition of Fe(3+) was successful in enhancing biomass production, which certainly improved the feasibility of biomass recycling in R. gelatinosus starch wastewater treatment. With optimal Fe(3+) dosage (20 mg/L), biomass production reached 4,060 mg/L, which was 1.63 times that of control group. Amylase activity was improved by 48 %. Both COD removal and starch removal reached 90 %. Hydraulic retention time was shortened by 25 %. Proper Fe(3+) dosage enhanced biomass production, but excess Fe(3+) was harmful for biomass accumulation.

Strengthening the growth of Rubrivivax gelatinosus in sewage purification through ferric ion regulated photophosphorylation and respiration.

Rubrivivax gelatinosus has the potential of biomass resource recycling combined with sewage purification. However, low biomass production and yield restricts the potential for sewage purification. Thus, this research investigated the improvement of biomass production and yield and organics reduction by Fe(3+) in R. gelatinosus wastewater treatment. Results showed that 10-30 mg/L Fe(3+) improved biomass yield in wastewater to a level found in culture medium. With optimal dosage (20 mg/L), biomass production reached 4,300 mg/L, which was 1.67 times that of the control group. Biomass yield was improved by 43.3%. Chemical oxygen demand (COD) removal reached above 91%. Hydraulic retention time was shortened by 25%. Mechanism analysis indicated that Fe(3+) enhanced the succinate and NADH dehydrogenase activities and, bacteriochlorophyll content in three energy metabolism pathways. These effects then enhanced adenosine triphosphate (ATP) production, which led to more biomass accumulation and COD removal. With 20 mg/L Fe(2+) dosage, succinate and NADH dehydrogenase, coproporphyrinogen III oxidase activities, bacteriochlorophyll content and ATP production were improved, respectively, by 48.4, 50.8, 50, 67 and 56% compared to those of the control group.

Improving biomass resource recycling capacity of Rubrivivax gelatinosus cultivated in wastewater through regulating the generation and use of energy.

This paper investigated Mg2+ enhancement of biomass production through regulating the generation and use of energy in Rubrivivax gelatinosus wastewater treatment. Results showed that proper Mg2+ dosage range was 1.5-15 mg/L. With optimal Mg2+ dosage (10 mg/L), biomass production (5010 mg/L) was improved by 60%. Both protein and chemical oxygen demand (COD) removals reached above 90%. Biomass yield improved by 38%. Hydraulic retention time was shortened by 25%. Mechanism analysis indicated that as activator, Mg2+ promoted specifically isocitrate dehydrogenase (IDH) and Ca2+ / Mg2+ -ATPase activities in energy metabolism, and then improved the generation of adenosine triphosphate (ATP) and the use of ATP. This enhanced the secretion and activity of protease, protein and COD removals, and then led to more biomass production. With 10 mg/L Mg2+, IDH and Ca2+ / Mg2+ -ATPase activities, ATP production, protease activity were improved by 43.8%, 40.6%, 39.4% and 46.5%, respectively.

[Degradation of benzothiazole in electro-assisted microbial reactor].

The oxidative degradation of benzothiazole (BTH) in a single-chamber electro-assisted microbial reactor was investigated. The effects of applied voltage and COD/BTH ratio on the performance of degrading benzothiazole were studied. The research showed that BTH was oxidized to 2-hydroxy-benzothiazole (OHBT), then thiazole ring scission, and BTH translated into 2-methylsulfonylaniline eventually. The degrading of benzothiazole was in conformity with the pseudo first-order kinetic model, and the pseudo first-order kinetic constant can be increased by raising the applied voltage and co-metabolism. When the applied voltage was 0.7 V and COD/BTH ratio was 30, the degradation rate was 96% in 48 h, achieving the detoxification of BTH, and that is advantageous to the biochemical treatment.