BCL6 is required for the thymic development of TCRαß+CD8αα+ intraepithelial lymphocyte lineage.

TCRαß+CD8αα+ intraepithelial lymphocytes (CD8αα+ αß IELs) are a specialized subset of T cells in the gut epithelium that develop from thymic agonist selected IEL precursors (IELps). The molecular mechanisms underlying the selection and differentiation of this T cell type in the thymus are largely unknown. Here, we found that Bcl6 deficiency in αß T cells resulted in the near absence of CD8αα+ αß IELs. BCL6 was expressed by approximately 50% of CD8αα+ αß IELs and by the majority of thymic PD1+ IELps after agonist selection. Bcl6 deficiency blocked early IELp generation in the thymus, and its expression in IELps was induced by thymic TCR signaling in an ERK-dependent manner. As a result of Bcl6 deficiency, the precursors of IELps among CD4+CD8+ double-positive thymocytes exhibited increased apoptosis during agonist selection and impaired IELp differentiation and maturation. Together, our results elucidate BCL6 as a crucial transcription factor during the thymic development of CD8αα+ αß IELs.

First Report of Leaf Tip Blight Caused by Epicoccum sorghinum on Phoebe bournei in Fujian, China.

Phoebe bournei, belonging to the family Lauraceae, is indigenous to China, where it is a protected species. In March 2022, ca. 90% of 20,000 P. bournei saplings suffered from leaf tip blight in a sapling nursery with an area of 200 m2 in Fuzhou, China. Initially, brown discoloration appeared on the tips of young leaves. The symptomatic tissue continued to expand as the leaf grew. To isolate the pathogen, 10 symptomatic leaves were randomly sampled from the nursery, and surface-sterilized in 75% alcohol for 30 s, followed by a 5% NaClO solution for 3 min, and then rinsed 3 times with sterile water. Twenty small pieces (0.3 x 0.3 cm) were excised from the margin of diseased and healthy tissue and transferred to five PDA plates amended with 50 µg/ml ampicillin. The plates were incubated at 25°C for 5 days. Finally, 17 isolates were obtained, and nine isolates with the highest isolation frequency shared the same morphological characteristics. On PDA, these colonies had aerial hyphae, white in the beginning, and became pale brown with the pigment production. Chlamydospores were observed after incubation for 7 days at 25°C, pale brown and nearly spherical, unicellular, or multicellular. Conidia were unicellular or bicellular, hyaline, and ellipsoidal, 5.15 to 9.89× 3.46 to 5.87 µm, n=50. The 9 fungi were identified as Epicoccum sp (Khoo et al. 2022a, b, c). Furthermore, strain MB3-1 was chosen randomly as the representative of the 9 isolates, and ITS, LSU, TUB sequences were amplified using the primers ITS1/ITS4, LR0R/LR5, Bt2a/Bt2b respectively (Raza et al. 2019). The sequences were submitted to NCBI and analyzed using BLAST. Results of BLAST showed that ITS (OP550308), LSU (OP550304), TUB (OP779213) sequences had 99.59% (490bp out of 492bp), 99.89% (870bp out of 871bp), 100% (321bp out of 321bp) identity to Epicoccum sorghinum sequences MH071389, MW800361, MW165323, respectively. ITS, LSU, TUB sequences were concatenated for phylogenetic analysis using the maximum likelihood method with 1000 bootstrap replicates in MEGA 7.0 software. The phylogenetic tree showed that MB3-1 was clustered together with E. sorghinum. Pathogenicity tests were performed on young leaves of healthy P. bournei saplings in vivo by inoculating with fungal conidia suspension. The conidia were eluted from the colony of MB3-1 and adjusted to 1×106 spores/ml. An amount of 20 µl conidia suspension (0.1% tween-80) was evenly sprayed on three leaves of one P. bournei sapling, 20 µl sterile water was sprayed on three other leaves of the same sapling as control, and three saplings were treated. All the treated saplings were kept at 25°C. MB3-1 caused leaf tip blight symptoms similar to those observed in nature at 6 days post inoculation (dpi). The pathogen was reisolated from inoculated leaves and identified as E. sorghinum. The experiment was repeated twice with the same results. Recently, E. sorghinum has been reported in Brazil (Gasparetto et al. 2017), Malaysia (Khoo et al. 2022a, b, c), and the United States (Imran et al. 2022). To our knowledge, this is the first report of E. sorghinum causing leaf tip blight on P. bournei. Wood from P. bournei is used to produce high-quality furniture due to its vertical grain and durability (Chen et al. 2020). And the demand for wood requires numerous saplings for afforestation. But this disease has the risk of causing insufficient saplings, which would affect the development of the P. bournei timber industry.

Therapeutic effects of Bombax ceiba flower aqueous extracts against loperamide-induced constipation in mice.

CONTEXT: Bombax ceiba Linnaeus (Bombacaceae) is known as silk cotton tree, the flowers of which are used in many medicinal applications. OBJECTIVE: To investigate the therapeutic effect of B. ceiba flower aqueous extracts (BCE) against loperamide-induced constipation and characterize the chemical composition of BCE. MATERIALS AND METHODS: Sixty male Kunming mice were divided into control (saline), model (10 mg/kg loperamide + saline), phenolphthalein (10 mg/kg loperamide + 10 mg/kg phenolphthalein) and different dosage of BCE (10 mg/kg loperamide + 40, 80 and 160 mg/kg BCE, respectively) groups, and received intragastric administrations for eight days. Faecal water content, number of faeces, first black-stool defecation time and gastrointestinal transit rates were evaluated. Various biochemical and molecular biomarkers were assessed in blood and colon. UPLC-ESI-QTOF-MS/MS was used to tentatively identify the composition of the BCE. RESULTS: BCE treatment (160 mg/kg) could increase faecal water (15.75%), faeces number (11.65%), gastrointestinal transit rate (25.37%) and decrease first black-stool defecation time (24.04%). The BCE (80 mg/kg) increased the serum level of motilin (30.62%), gastrin (54.46%) and substance P (18.99%), and decreased somatostatin (19.47%). Additionally, the BCE (160 mg/kg) reduced the mucosal damage, restored colonic goblet cell function, down-regulated the protein expression of AQP3 (33.60%) and increased c-kit protein expression (11.63%). Twelve known compounds, including protocatechuic acid, chlorogenic acid and rutin, previously reported in B. ceiba, were identified in the BCE. DISCUSSION AND CONCLUSIONS: This study suggested that BCE is a promising agent for the treatment of constipation.

Mechanisms of the antiangiogenic effects of aspirin in cancer.

Aspirin is an old drug extracted from willow bark and is widely used for the prevention and treatment of cardiovascular diseases. Accumulating evidence has shown that aspirin use may significantly reduce the angiogenesis of cancer; however, the mechanism of the association between angiogenesis and aspirin is complex. Although COX-1 is widely known as a target of aspirin, several studies reveal other antiangiogenic targets of aspirin, such as angiotensin II, glucose transporter 1, heparanase, and matrix metalloproteinase. In addition, some data indicates that aspirin may produce antiangiogenic effects after acting in different cell types, such as endothelial cells, platelets, pericytes, and macrophages. In this review, we concentrate on research regarding the antiangiogenic effects of aspirin in cancer, and we discuss the molecular mechanisms of aspirin and its metabolites. Moreover, we discuss some mechanisms through which aspirin treatment may normalize existing blood vessels, including preventing the disintegration of endothelial adheres junctions and the recruitment of pericytes. We also address the antiangiogenic effects and the underlying mechanisms of aspirin derivatives, which are aimed at improving safety and efficacy.