BackgroundSensing and responding to environmental changes is a central aspect of cell division regulation. Mycobacterium tuberculosis contains eleven Ser/Thr kinases, two of which, PknA and PknB, are key signaling molecules that regulate cell division/morphology. One substrate of these kinases is Wag31, and we previously showed that partial depletion of Wag31 caused morphological changes indicative of cell wall defects, and that the phosphorylation state of Wag31 affected cell growth in mycobacteria. In the present study, we further characterized the role of the Wag31 phosphorylation in polar peptidoglycan biosynthesis.ResultsWe demonstrate that the differential growth among cells expressing different wag31 alleles (wild-type, phosphoablative, or phosphomimetic) is caused by, at least in part, dissimilar nascent peptidoglycan biosynthesis. The phosphorylation state of Wag31 is found to be important for protein-protein interactions between the Wag31 molecules, and thus, for its polar localization. Consistent with these results, cells expressing a phosphomimetic wag31 allele have a higher enzymatic activity in the peptidoglycan biosynthetic pathway.ConclusionsThe Wag31Mtb phosphorylation is a novel molecular mechanism by which Wag31Mtb regulates peptidoglycan synthesis and thus, optimal growth in mycobacteria.

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Fine needle aspiration cytology (FNAC) and washout thyroglobulin (Tg) measurements are the standard for evaluating a metastatic lymph node (LN) in thyroid cancer. However, patients rarely benefit from these procedures due to false results. This study aims to identify a reliable biomarker that significantly improves the diagnosis of metastatic LNs, in addition to FNAC and washout Tg. This study analyzed 130 LNs that were suspected to have metastases on thyroid ultrasonography, from June 2016 to December 2017. All subjects underwent FNAC, washout Tg measurements and a new biomarker, washout Cytokeratin fragment 21-1 (CYFRA 21-1) measurement. The final LN outcomes were confirmed by surgical histology, repeat FNAC, or follow-up image. The diagnostic values of the presence of washout CYFRA 21-1 for diagnosing metastatic LNs were evaluated according to final LN outcomes. Among the 130 LNs, 42 were metastatic lesions and 88 were benign. The washout CYFRA 21-1 levels were significantly higher in metastatic LNs than in benign LNs. In contrast to the findings of washout Tg, washout CYFRA 21-1 showed little overlap between benign and malignant LNs, and its diagnostic cutoff values were not affected by surgery. The combinations of FNAC and washout CYFRA 21-1 showed higher sensitivity (91.9%), specificity (96.5%), negative predictive value (98.8%), and diagnostic accuracy (94.2%) than FNAC with washout Tg. The combination of FNAC, washout Tg, and washout CYFRA 21-1 showed the best sensitivity (98.8%). When washout CYFRA 21-1 was applied to the discordant results that were observed between FNAC and washout Tg, 20 of 22 LNs were correctly diagnosed. Washout CYFRA 21-1 measurements in thyroid LNs provide a diagnostic modality.

Background: Peroxisome proliferator-activated receptor-gamma (PPAR-γ) ligands have been widely shown to correlate with epithelial-mesenchymal transition (EMT) and cancer progression. Lobeglitazone (LGZ) is a novel ligand of PPAR-γ; and its role in EMT and metastasis in papillary thyroid carcinoma (PTC) is poorly understood. We aimed to investigate the role of LGZ in metastatic behavior of PTC cells. Methods: Half maximal inhibitory concentration (IC50) values of LGZ in BRAF-mutated PTC cell lines (BCPAP and K1) were determined using MTT assay. Rosiglitazone (RGZ), the PPAR-γ ligand was used as a positive control. The protein expression of PPAR-γ, cell-surface proteins (E-cadherin, N-cadherin), cytoskeletal protein (Vimentin), transcription factor (Snail), p38 mitogenactivated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) 1/2 pathway, and matrix metalloproteinase (MMP)-2 expression were measured using Western blotting. Changes in E-cadherin expression were also determined using immunocytochemistry. Cell migration and invasion were analyzed using wound healing and Matrigel invasion assays. Results: Treatment with LGZ or RGZ significantly inhibited transforming growth factor-beta1 (TGF-β1)-induced EMT-associated processes such as fibroblast-like morphological changes, EMT-related protein expression, and increased cell migration and invasion in BCPAP and K1 cells. LGZ restored TGF-β1-induced loss of E-cadherin, as observed using immunocytochemistry. Furthermore, LGZ and RGZ suppressed TGF-β1-induced MMP-2 expression and phosphorylation of p38 MAPK, but not ERK1/2. Although there was no change in PPAR-γ expression after treatment with LGZ or RGZ, the effect of downstream processes mediated by LGZ was hampered by GW9662, a PPAR-γ antagonist. Conclusion:LGZ inhibits TGF-β1-induced EMT, migration, and invasion through the p38 MAPK signaling pathway in a PPAR-γdependent manner in PTC cells.