The putative ceramide-conjugation protein Cwh43 regulates G0 quiescence, nutrient metabolism and lipid homeostasis in fission yeast

Cellular nutrient states control whether cells proliferate, or whether they enter or exit quiescence. Here, we report characterizations of fission yeast temperature-sensitive (ts) mutants of the evolutionarily conserved transmembrane protein Cwh43, and explore its relevance to utilization of glucose, nitrogen source and lipids. GFP-tagged Cwh43 localizes at ER associated with the nuclear envelope and the plasma membrane, as in budding yeast. We found that cwh43 mutants failed to divide in low glucose and lost viability during quiescence under nitrogen starvation. In cwh43 mutants, comprehensive metabolome analysis demonstrated dramatic changes in marker metabolites that altered under low glucose and/or nitrogen starvation, although cwh43 cells apparently consumed glucose in the culture medium. Furthermore, we found that cwh43 mutant cells had elevated levels of triacylglycerols (TGs) and coenzyme A, and that they accumulated lipid droplets. Notably, TG biosynthesis was required to maintain cell division in the cwh43 mutant. Thus, Cwh43 affects utilization of glucose and nitrogen sources, as well as storage lipid metabolism. These results may fit a notion developed in budding yeast stating that Cwh43 conjugates ceramide to glycosylphosphatidylinositol (GPI)-anchored proteins and maintains integrity of membrane organization

The impact of HCV eradication by direct-acting antivirals on the transition of precancerous hepatic nodules to HCC: A prospective observational study

Background & Aims It remains controversial whether the eradication of hepatitis C virus (HCV) by interferon (IFN)‐free anti‐HCV therapy using direct‐acting antivirals (DAAs) suppresses or promotes hepatocellular carcinoma (HCC) development. We investigated the influence of HCV eradication by DAA therapy on HCC development, by observing changes of non‐hypervascular hypointense nodules (NHHNs) by gadolinium‐ethoxybenzyl‐diethylenetriamine pentaacetic acid‐enhanced magnetic resonance imaging (EOB‐MRI). Methods A total of 401 patients treated with DAA therapy who did not have a history of HCC were enrolled in this prospective cohort study. All patients underwent EOB‐MRI prior to the start of DAA therapy and were followed up periodically after therapy. The progression of NHHNs detected at baseline to typical HCC, as indicated by hypervascularization and the incidence of newly emergent NHHNs, was analyzed. Results In comparison of patients who achieved sustained virologic response (SVR) with propensity score‐matched patients with persistent HCV infection, there was no difference in the incidence of hypervascularization of NHHNs to typical HCC among patients who had NHHNs at baseline. Among patients who did not have NHHNs at baseline, the incidence of the new emergence of NHHNs did not differ between study patients and propensity score–matched patients with persistent HCV infection. Conclusions During a 2‐year observation period after SVR, the eradication of HCV by IFN‐free DAA therapy did not suppress or enhance HCC development. (UMIN000017020)

Smoking‐induced radiation laryngeal necrosis after definitive radiotherapy alone for T1a glottic squamous cell carcinoma: A case report

Abstract Background We report the case of a patient with smoking‐induced radiation laryngeal necrosis (RLN) after undergoing definitive radiotherapy (RT) alone for T1a glottic squamous cell carcinoma. Case The patient was a 63‐year‐old man who had a history of heavy smoking. He quit smoking when he was diagnosed with glottic squamous cell carcinoma. The RT dose was 63 Gy, delivered in 28 fractions with the three‐dimensional conventional RT technique for the larynx. After RT completion, the initial treatment response was complete response. He then underwent follow‐up examinations. At 13 months after RT, the patient resumed smoking. At 2 months after resuming smoking, he had severe sore throat and hoarseness. Laryngoscopy revealed a large tumor in the glottis. Surgical excision was performed, and the patient was histologically diagnosed with RLN, as late toxicity without cancer recurrence. At 3 weeks postoperatively, the patient had dyspnea, and laryngoscopy revealed total laryngeal paralysis. Thus, he underwent an emergent tracheostomy. The administration of steroids affected RLN, and laryngeal paralysis gradually improved. Conclusions This case suggests that smoking may have the potential to induce RLN after RT. Moreover, continuing smoking cessation is significantly important for patients with glottic cancer who receive RT. Rather than leaving smoking cessation up to the patient, it would be necessary for clinicians to actively intervene to help patients continue their effort to quit smoking

The method used to obtain reproducible data for microarray analysis conducted on serum-extracted samples.

<p>A. NL patients’ serum were sampled twice. In the first, RNA was extracted first from untreated serum, and then extracted again from serum treated with exoquick. In the second serum sample, RNA was also extracted from both untreated serum and serum treated with exoquick. Microarray analysis was conducted for RNA in a total of four samples. B. Reproducibility test of microarray data. Scatter plots comparing non- normalized signal intensities of miRNAs in two independent experiments from human total serum and exosome rich fraction. Red and black denotes high and low miRNA expressions respectively. Total serum extracted first, versus exosome rich fraction first (left), total serum extracted first versus second (middle), and exosome rich fraction extracted first versus second (right). C. Pearson’s pairwise correlations of signal intensities of miRNAs from human total serum and exosome rich fraction. D. Western blot was performed for untreated serum, serum extracted by exoquick and exosome fraction from PNT-2, using anti-CD63.</p

The list of miRNAs used to obtain the maximum correlation coefficient between miRNA expression level, and clinical characteristics.

<p>Pairwise heatmap showing miRNAs and their correlation coefficient and p-values.</p

Pairwise heatmap of the miRNAs used for classifying two arbitrary groups.

<p>Pairwise heatmap showed the miRNAs and their p-value of two arbitrary groups.</p