MTHFD2-mediated redox homeostasis promotes gastric cancer progression under hypoxic conditions.

OBJECTIVES: Cancer cells undergo metabolic reprogramming to adapt to high oxidative stress, but little is known about how metabolic remodeling enables gastric cancer cells to survive stress associated with aberrant reactive oxygen species (ROS) production. Here, we aimed to identify the key metabolic enzymes that protect gastric cancer (GC) cells from oxidative stress. METHODS: ROS level was detected by DCFH-DA probes. Multiple cell biological studies were performed to identify the underlying mechanisms. Furthermore, cell-based xenograft and patient-derived xenograft (PDX) model were performed to evaluate the role of MTHFD2 in vivo. RESULTS: We found that overexpression of MTHFD2, but not MTHFD1, is associated with reduced overall and disease-free survival in gastric cancer. In addition, MTHFD2 knockdown reduces the cellular NADPH/NADP+ ratio, colony formation and mitochondrial function, increases cellular ROS and cleaved PARP levels and induces in cell death under hypoxia, a hallmark of solid cancers and a common inducer of oxidative stress. Moreover, genetic or pharmacological inhibition of MTHFD2 reduces tumor burden in both tumor cell lines and patient-derived xenograft-based models. DISCUSSION: our study highlights the crucial role of MTHFD2 in redox regulation and tumor progression, demonstrating the therapeutic potential of targeting MTHFD2.

L-tryptophan anaerobic fermentation for indole acetic acid production: Bacterial enrichment and effects of zero valent iron.

Indole acetic acid (IAA) as a plant hormone, was one of the valuable products of anaerobic fermentation. However, the enriching method remained unknown. Moreover, whether zero valent iron (ZVI) could enhance IAA production was unexplored. In this work, IAA producing bacteria Klebsiella (63 %) was enriched successfully. IAA average production rate and concentration were up to 3 mg/L/h and 56 mg/L. With addition of 1 g/L ZVI, IAA average production rate and concentration was increased for 2 and 3 folds. Mechanisms indicated ZVI increased Na+K+-ATP activity and electron transport activity for 2 folds and 1 fold. Moreover, macro transcription determined indole pyruvate pathway activity like primary-amine oxidase, indole pyruvate decarboxylase and aldehyde dehydrogenase were increased for 146 %, 187 %, and 557 %, respectively. Therefore, ZVI was suitable for enhancement IAA production from mixed culture anaerobic fermentation.

Development and application of a low-priced duplex quantitative PCR assay based on SYBR Green I for the simultaneous detection of porcine deltacoronavirus and porcine sapelovirus.

Porcine deltacoronavirus (PDCoV) and porcine sapelovirus (PSV) are two viruses that can cause diarrhoea in pigs and bring great economic loss to the pig industry. In this research, a duplex real-time quantitative polymerase chain reaction (qPCR) assay based on SYBR Green I was developed to simultaneously detect PDCoV and PSV. No specific melting peaks were found in other porcine diarrhoea-associated viruses, indicating that the method developed in this study had good specificity. The detection limits of PDCoV and PSV were 1.0 × 101 copies µl-1 and 1.0 × 102 copies µl-1, respectively. The duplex real-time qPCR assay tested two hundred and three (203) intestinal and faecal samples collected from diarrhoeal and asymptomatic pigs. The positive rates of PDCoV and PSV were 20.2% and 23.2%, respectively. The co-infection rate of PDCoV and PSV was 13.8%. To evaluate the accuracy of the developed method, conventional PCR and singular TaqMan real-time qPCR assays for PDCoV/PSV were also used to detect the samples. The results showed that the duplex real-time qPCR assay was consistent with the singular assays, but its sensitivity was higher than conventional PCR methods. This duplex real-time qPCR assay provides a rapid, sensitive and reliable method in a clinic to simultaneously detect PDCoV and PSV.

Correction: Catalytic (3 + 2) umpolung annulations of α-thioacyl carbenes with aryl isothiocyanates.

Correction for 'Catalytic (3 + 2) umpolung annulations of α-thioacyl carbenes with aryl isothiocyanates' by Ziyang Dong et al., Chem. Commun., 2022, 58, 7980-7983, https://doi.org/10.1039/D2CC02882D.

Development and immunogenicity evaluation of porcine deltacoronavirus inactivated vaccine with different adjuvants in mice.

Porcine deltacoronavirus (PDCoV) is a novel coronavirus that causes diarrhea in pigs of various ages, especially in suckling piglets, and there are no effective measures to prevent and control PDCoV currently. In this study, two adjuvants Al(OH)3 and ODN2395 working through different mechanisms were used to prepare inactivated PDCoV vaccines, and the immune effects of PDCoV inactivated vaccines were assessed in mice. From the results, we found that both PDCoV/Al(OH)3 vaccine and PDCoV/2395 vaccine could induce IgG and neutralizing antibodies with high levels in mice. At the same time, cytokines of IFN-γ, IL-4 and chemokine ligand of CXCL13 in serum were significantly increased after immunization, and reached the highest levels in PDCoV/2395 vaccine group, which suggested that PDCoV/2395 could promote the production of both Th1 and Th2 polarized cytokines. In addition, histopathological observations showed that vaccination helped mice resist PDCoV infection. These results indicated that both the two inactivated vaccines have good immune effects. Moreover, the PDCoV/2395 vaccine worked better than the PDCoV/Al(OH)3 vaccine for PDCoV/2395 having the good ability to induce both humoral and cellular immunogenicity. The PDCoV/2395 inactivated vaccine developed in this study might be an effective tool for the prevention of PDCoV infection.

Catalytic (3 + 2) umpolung annulations of α-thioacyl carbenes with aryl isothiocyanates.

1,2,3-Thiadiazoles serve as masked S-electrophilic thia-1,3-dipoles. Under rhodium/racemic BINAP catalysis, they undergo denitrogenative (3 + 2) umpolung transannulations with aryl isothiocyanates with inverse regioselectivity and excellent stereoselectivity, yielding N-aryl 3H-1,2-dithiol-(Z)-3-imines in a redox-neutral, step-efficient, and functionality-tolerant manner. An intramolecular S-S bond is impressively forged.

[Exploration on the rules of acupoints selection for phlegm disorder treated with acupuncture and moxibustion based on ancient literature study].

OBJECTIVE: To analyze the rules of acupoints selection for phlegm disorder in treatment with acupuncture and moxibustion in ancient literature so as to provide guidance to clinical treatment of phlegm disorder. METHODS: The word "phlegm" was taken as the search term and the relevant articles were retrieved from Zhonghuayidian (Dictionary of Chinese Medicine). According to the inclusion and exclusion criteria, the articles were screened and the database was set up. The analysis was conducted on acupoint selection, the correlation with meridians involved and distribution location, as well as the use frequency of specific points and acupoint combination. RESULTS: It was found that in treatment of phlegm disorder, the highest frequently used acupoints were Zusanli (ST36) and Zhongwan (CV12). The use frequency of three yang meridians was higher than that of three yin meridians. The commonly involved meridians were the Conception Vessel, Bladder Meridian of Foot-taiyang and the Governor Vessel. The acupoints located in the chest and abdomen were highly used. The use frequency of specific points was higher than that of non-specific ones. The sequence of the use frequency of specific points, from high to low, is the crossing point, the front-mu point and luo-connecting point. The combination of Danzhong (CV17) and Zusanli (ST36) is of the high frequency. CONCLUSION: Ancient medical scholars focus on regulating spleen and stomach functions, as well as qi activity in treatment of phlegm disorder with acupuncture and moxibustion, which is coincident with the treatment principle of phlegm disorder in traditional Chinese medicine. In treatment, acupuncture-moxibusiton is characterized as laying the emphasis on the specific points, the local acupoints and the holistic idea as " regulation of yang for yin disorder"．.