Regulation of heparin-binding EGF-like growth factor expression by phorbol ester in a human hepatoma-derived cell line

AbstractHeparin-binding EGF-like growth factor (HB-EGF) is a recently identified potent mitogen for smooth muscle cells and fibroblasts. HB-EGF has been shown to be an EGF receptor ligand, and also to stimulate epithelial cell growth. A human hepatoma-derived cell line, Mahlavu, was analyzed for the production of HB-EGF mRNA and active HB-EGF protein. It was found that the cell line synthesized very low or undetectable basal level of HB-EGF mRNA. However, the addition of 12-O-tetradecanoylphorbol-13-acetate (TPA) led to a rapid and transient rise in HB-EGF mRNA level. HB-EGF in Mahlavu cells appears to be regulated by a protein kinase C (PKC) pathway, since PKC inhibitors, H7, staurosporin, and calphostin C, abrogated the induction of HB-EGF mRNA by TPA. Unlike vascular smooth muscle cells, induction of HB-EGF gene transcription by TPA was blocked completely by incubation with cycloheximide, suggesting that protein synthesis may be a prerequisite for HB-EGF gene transcription in Mahlavu cells. Mahlavu cells were also found to release a bioactive HB-EGF-like protein into conditioned medium which stimulates DNA synthesis in EP170.7 cells. This activity was neutralized by an anti-HB-EGF antibody. These results indicate that HB-EGF gene transcription is regulated via a PKC pathway, resulting in secretion of active HB-EGF into the culture medium of hepatoma-derived Mahlavu cells

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Food phytochemicals, epigallocatechin gallate and myricetin, covalently bind to the active site of the coronavirus main protease in vitro

SARS-CoV-2 main protease is a possible target for protection against viral infection. This study examined the inhibitory effect of food phytochemicals on the main protease of SARS-CoV-2 by determining a cleaved product after chromatographic separation. First, 37 phytochemicals, including glycosides and metabolites, were screened at 20 µM; epigallocatechin gallate, myricetin, theaflavin, herbacetin, piceatannol, myricitrin, and isothiocyanates inhibited the enzyme in varying degrees. The IC50 values were estimated from 0.4 to 33.3 µM against the 0.5-µM enzyme. The dose-dependent adduction of epigallocatechin gallate and myricetin was confirmed by quinone staining of protein blotted onto a membrane. The enzyme activity was decreased by increasing the concentration of the two phytochemicals, accompanied by increasing the respective adducted molecule estimated by intact mass spectrometry. Reduced glutathione canceled the formation of conjugate and the inhibitory effect of epigallocatechin gallate or myricetin on the enzyme, suggesting that the formation of the quinone moiety in the phytochemicals is critical for the inhibition. The covalent binding of epigallocatechin gallate or myricetin to the cysteine residue at the active site was confirmed by analyzing peptides from the chymotrypsin-digested main protease

Evaluation of the 8th Edition TNM Classification for Anaplastic Thyroid Carcinoma

Background: The tumor–node–metastasis (TNM) classification system to categorized anaplastic thyroid cancer (ATC) was revised. Methods: The revised system was evaluated using a large database of ATC patients. Results: A total of 757 patients were analyzed. The proportion and median overall survival values (OS: months) for each T category were T1 (n = 8, 1.1%, 12.5), T2 (n = 43, 5.7%, 10.9), T3a (n = 117, 15.5%, 5.7), T3b (n = 438, 57.9%, 3.9), and T4 (n = 151, 19.9%, 5.0). The OS of the N0 and N1 patients were 5.9 and 4.3, respectively (log-rank p < 0.01). Sixty-three (58.3%) patients migrated from stage IV A to IV B by revision based on the existence of nodal involvement and 422 patients (55.7%) were stratified into stage IV B, without a worsening of their OS (6.1), leaving 45 patients (5.9%) in stage IV A with fair OS (15.8). The hazard ratios for the survival of the patients of stage IV B compared to stage IV A increased from 1.1 to 2.1 by the revision. No change was made for stage IV C (n = 290, 38.8%, 2.8). Conclusion: The revised TNM system clearly indicated the prognoses of ATC patients by extracting rare patients with fair prognoses as having stage IV A disease and categorized many heterogeneous patients in stage IV B