Molecular characterization of a catalase gene in the freshwater green alga Closterium ehrenbergii and its putative function against abiotic stresses.

Catalases (CATs) are ubiquitous antioxidant enzymes that prevent cellular oxidative damage through the decomposition of H2O2. However, there is relatively little information on CAT in the worldwide-distributed freshwater green alga Closterium ehrenbergii. Here, we cloned the full-length catalase cDNA from C. ehrenbergii (CeCAT) and characterized its structural features and expressional responses against aquatic contaminants. The open reading frame of CeCAT was determined to be 1476 bp, encoding 491 amino acids with a theoretical molecular mass of 56.1 kDa. The CeCAT protein belongs to the NADPH-binding CAT family and might be located in the cytosol. BLAST and phylogenetic results showed that CeCAT had a high identity with CAT proteins from other microalgae and the water lily Nymphaea colorata (Streptophyta). The transcriptional levels of CeCAT were significantly upregulated by the metal copper and herbicide atrazine, but little affected by other tested metals (Ni and Cr) and endocrine-disrupting chemicals (polychlorinated biphenyl, PCB). The maximum expression was registered under 0.1 mg/L CuCl2 and 0.2 mg/L CuSO4 exposures. In addition, excess copper considerably increased production of reactive oxygen species in the cells. These results suggest that CeCAT may function to defend against oxidative stress in green algae and can respond specifically to different kinds of metals and herbicides.

Faecal Microbiota Transplantation Alleviates Ferroptosis after Ischaemic Stroke.

Ischaemic stroke can induce changes in the abundance of gut microbiota constituents, and the outcome of stroke may also be influenced by the gut microbiota. This study aimed to determine whether gut microbiota transplantation could rescue changes in the gut microbiota and reduce ferroptosis after stroke in rats. Male Sprague-Dawley rats (6 weeks of age) were subjected to ischaemic stroke by middle cerebral artery occlusion (MCAO). Fecal samples were collected for 16S ribosomal RNA (rRNA) sequencing to analyze the effects of FMT on the gut microbiota. Neurological deficits were evaluated using the Longa score. triphenyl tetrazolium chloride (TTC) staining was performed in the brain, and kits were used to measure malondialdehyde (MDA), iron, and glutathione (GSH) levels in the ipsilateral brain of rats. Western blotting was used to detect the protein expression levels of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), and the transferrin receptor 2 (TFR2) in the ipsilateral brain of rats. Stroke induced significant changes in the gut microbiota, and FMT ameliorated these changes. TTC staining results showed that FMT reduced cerebral infarct volume. In addition, FMT diminished MDA and iron levels and elevated GSH levels in the ipsilateral brain. Western blot analysis showed that FMT increased GPX4 and SLC7A11 protein expression and decreased TFR2 protein expression in the ipsilateral brain after stroke. FMT can reverse gut microbiota dysbiosis, reduce cerebellar infarct volume, and decrease ferroptosis after stroke.

Activation of the Wnt pathway through Wnt2 promotes metastasis in pancreatic cancer.

Wnt signaling pathway plays an important role in physiological and pathological process, including in the occurrence and development of tumor. The purpose of this study is to determine whether Wnt2 and sFRP4, key molecules of signaling pathway, are of prognostic value for survival in patients with pancreatic cancer. We performed immunohistochemistry on tissue microarrays containing 90 pancreatic cancer specimens to evaluate the protein expression of Wnt2 and sFRP4. Our results showed that the cytoplasmic expression level of Wnt2 in pancreatic cancer tissues was significantly associated with LNM (P=0.029) and AJCC stage (P=0.008). Additionally, Kaplan-Meier analysis indicated that high Wnt2 expression was significantly correlated with poor clinical outcomes of patients with pancreatic cancer. In conclusion, Wnt2 may play an important role in the development of pancreatic cancer through activation of the Wnt pathways and serve as a potential candidate for treatment target of pancreatic cancer.

Expression of Gli1 and Wnt2B correlates with progression and clinical outcome of pancreatic cancer.

OBJECTIVE: The aim of this study was to investigate the expression and clinical significance of Gli1 and Wnt2B in pancreatic cancer. METHODS: We have constructed a formalin-fixed paraffin embedded pancreatic tissue microarrays 180 cylindrical tissue cores of human pancreatic cancer and its paracancerous nonmalignant pancreatic specimens (NMPs) from 90 patients. Levels of Gli1 and Wnt2B were measured by immunohistochemistry. We analyzed the correlations between the expression of these factors and clinicopathological parameters including prognosis. RESULTS: The expressions of both Gli1 and Wnt2B in human pancreatic cancer tissues were significantly higher than those of normal pancreatic tissues (P=0.000, P=0.004 respectively). The analysis showed that the high cytoplasmic expression levels of Gli1 in pancreatic cancer tissues had significant correlation with lymph node metastasis (P=0.036) and Wnt2B had significant correlation with perineural invasion (P=0.045). Gli1 and Wnt2B have no positive correlation. Survival analysis by Kaplan-Meier demonstrated that elevated Wnt2B expression in cancer tissue predicted worse overall survival (OS) compared with group in lower expression (P=0.024). No correlation was found between the expression of Gli1 and overall survival of pancreatic cancer patients (P>0.05). CONCLUSIONS: In conclusion, these results indicate that the high-expression levels of Gli1 and Wnt2B might play a pivotal role during tumorigenesis of pancreatic cancer, and the high expression of Wnt2B might be associated with poor prognosis.

[Study of the disease burden of patients with drug-resistant and drug-sensitive tuberculosis in Guangdong and Zhejiang provinces].

OBJECTIVE: To investigate the disease burden of drug-resistant and drug-sensitive tuberculosis (TB) patients in Guangdong and Zhejiang provinces. METHODS: Three hundred and two patients with TB, who had been involved in the project for drug resistance surveillance and completed the full course of treatment, were enrolled for this study. The proportion method for drug susceptibility was used. The method of disability adjusted life year (DALY) was applied to assess the disease burden of TB patients. RESULTS: The average DALYs of initial cases with drug-sensitive and drug-resistant TB, and retreated cases with drug-sensitive and drug-resistant TB, were 0.26, 0.68, 0.49, and 1.04, respectively. The average DALY loss of drug-resistant TB patients was 0.86 and that of drug-sensitive TB patients was 0.44. CONCLUSIONS: The values of DALY for initial and retreated cases with drug-resistant TB were 2 times higher than those for patients with drug-sensitive TB, indicating the higher disease burden in drug-resistant TB patients. Therefore, to reduce the disease burden of patients with drug-resistant TB, standardized protocols must be applied in the treatment of TB.