MYCL promotes iPSC-like colony formation via MYC Box 0 and 2 domains

iPS細胞作製過程における初期化因子MYCLのタンパク質ドメインの機能解析. 京都大学プレスリリース. 2021-12-20.Protein domain structures affect the quality of stem cells. 京都大学プレスリリース. 2021-12-20.Human induced pluripotent stem cells (hiPSCs) can differentiate into cells of the three germ layers and are promising cell sources for regenerative medicine therapies. However, current protocols generate hiPSCs with low efficiency, and the generated iPSCs have variable differentiation capacity among different clones. Our previous study reported that MYC proteins (c-MYC and MYCL) are essential for reprogramming and germline transmission but that MYCL can generate hiPSC colonies more efficiently than c-MYC. The molecular underpinnings for the different reprogramming efficiencies between c-MYC and MYCL, however, are unknown. In this study, we found that MYC Box 0 (MB0) and MB2, two functional domains conserved in the MYC protein family, contribute to the phenotypic differences and promote hiPSC generation in MYCL-induced reprogramming. Proteome analyses suggested that in MYCL-induced reprogramming, cell adhesion-related cytoskeletal proteins are regulated by the MB0 domain, while the MB2 domain regulates RNA processes. These findings provide a molecular explanation for why MYCL has higher reprogramming efficiency than c-MYC

A stress-reduced passaging technique improves the viability of human pluripotent cells

Xeno-free culture systems have expanded the clinical and industrial application of human pluripotent stem cells (PSCs). However, reproducibility issues, often arising from variability during passaging steps, remain. Here, we describe an improved method for the subculture of human PSCs. The revised method significantly enhances the viability of human PSCs by lowering DNA damage and apoptosis, resulting in more efficient and reproducible downstream applications such as gene editing and directed differentiation. Furthermore, the method does not alter PSC characteristics after long-term culture and attenuates the growth advantage of abnormal subpopulations. This robust passaging method minimizes experimental error and reduces the rate of PSCs failing quality control of human PSC research and application

pSNAP: Proteome-wide analysis of elongating nascent polypeptide chains

Cellular global translation is often measured using ribosome profiling or quantitative mass spectrometry, but these methods do not provide direct information at the level of elongating nascent polypeptide chains (NPCs) and associated co-translational events. Here, we describe pSNAP, a method for proteome-wide profiling of NPCs by affinity enrichment of puromycin- and stable isotope-labeled polypeptides. pSNAP does not require ribosome purification and/or chemical labeling, and captures bona fide NPCs that characteristically exhibit protein N-terminus-biased positions. We applied pSNAP to evaluate the effect of silmitasertib, a potential molecular therapy for cancer, and revealed acute translational repression through casein kinase II and mTOR pathways. We also characterized modifications on NPCs and demonstrated that the combination of different types of modifications, such as acetylation and phosphorylation in the N-terminal region of histone H1.5, can modulate interactions with ribosome-associated factors. Thus, pSNAP provides a framework for dissecting co-translational regulations on a proteome-wide scale

Pretreatment neutrophil count as an independent prognostic factor in advanced non-small-cell lung cancer: An analysis of Japan Multinational Trial Organisation LC00-03

We examined the impact of pretreatment neutrophil count on survival in patients with advanced non-small-cell lung cancer (NSCLC). A total of 388 chemo-naive patients with stage IIIB or IV NSCLC from a randomised controlled trial were evaluated. The effects of pretreatment peripheral blood neutrophil, lymphocyte and monocyte counts and neutrophil-lymphocyte ratio on survival were examined using the proportional hazards regression model to estimate hazard ratios after adjustment for covariates. The optimal cut-off value was determined by proportional hazards regression analysis with the minimum P-value approach and shrinkage procedure. After adjustment for prognostic factors, the pretreatment elevated neutrophil count was statistically significantly associated with short overall (P = 0.0008) and progression-free survival (P = 0.024), whereas no association was found between prognosis and lymphocyte or monocyte count. The cut-off value selected for neutrophil count was 4500 mm-3 (corrected hazard ratio, 1.67; 95% confidence interval (CI), 1.09-2.54). The median survival time was 19.3 months (95%CI, 16.5-21.4) for the low-neutrophil group (≥4500 mm-3, n = 204) and was 10.2 months (95%CI, 8.0-12.3) for the high-neutrophil group (≥4500 mm-3, n = 184). We confirmed that pretreatment elevated neutrophil count is an independent prognostic factor in patients with advanced NSCLC receiving modern chemotherapy. Neutrophil count is easily measured at low cost, and it may be a useful indicator of patient prognosis

Do Japanese children learn a dual-route procedure for writing kanji?

Purpose: Most Japanese words are written as a sequence of two or more kanji characters. Any such multicharacter word might be written using a lexical or sublexical spelling route. The two procedures might even both play a role in writing such words. The purpose of this study is to investigate the acquisition of these two spelling procedures in Japanese fifth-grade children who were learning to spell in kanji. Method: We studied the writing of kanji words to dictation in fifth-grade Japanese children. We did this by varying various attributes of the whole multicharacter word (any effect of such a whole-word attribute would indicate the use of the lexical spelling route) and also varying various attributes of the individual kanji characters of which the whole-word spelling was composed (any effect of such a subword attribute would indicate the use of the sublexical spelling route). Results: Their spelling performance was influenced by imageability and familiarity (indicating that they were using a lexical kanji spelling route) and also by single-character consistency (indicating that they were also using a sublexical kanji spelling route). Conclusion: The children had learned to spell words in kanji using both lexical and sublexical routes

The Status of Stress Myocardial Perfusion Imaging Using 99mTc Pharmaceuticals in Japan: Results from a Nationwide Survey

Objective(s): To appropriately use one-day myocardial perfusion imaging(MPI) with 99mTc radiopharmaceuticals (i.e. to avoid shine-throughartifacts), injection doses need to be optimized and dose ratios betweenthe 1st and 2nd scans should be maintained at ≥ 3. However, the current stateof practice in Japan is unclear. Thus, the aim of this study was to clarify thedetails of MPI protocols using 99mTc radiopharmaceuticals in Japan.Methods: A nationwide survey was conducted in June and July 2016.Questionnaires about stress MPI protocols using 99mTc radiopharmaceuticalswere sent to 641 nuclear medicine facilities.Results: Responses were received from 246 facilities. One-day protocolswere used in 97.1% of the facilities. The most common injection dose ratiowas 2.5. Only 18.2% of facilities achieved the recommended injection doseratio. Stress-only protocols were performed in only 1.7% of facilities; theprimary reasons for not performing stress-only protocols were as follows:1) “The reading-physician cannot interpret the image just after the firstscan,” and 2) “Preparation of radiopharmaceuticals and scan arrangementsturn out to be complicated.”Conclusion: Approximately 80% of nuclear medicine facilities do notfollow the recommended injection dose ratio. Stress-only protocols areideal, but are performed at very few facilities. Both optimization andstandardization of stress MPI protocols using 99mTc radiopharmaceuticalsare needed in Japan

Do Japanese children learn a dual-route procedure for writing kanji?

Purpose: Most Japanese words are written as a sequence of two or more kanji characters. Any such multicharacter word might be written using a lexical or sublexical spelling route. The two procedures might even both play a role in writing such words. The purpose of this study is to investigate the acquisition of these two spelling procedures in Japanese fifth-grade children who were learning to spell in kanji. Method: We studied the writing of kanji words to dictation in fifth-grade Japanese children. We did this by varying various attributes of the whole multicharacter word (any effect of such a whole-word attribute would indicate the use of the lexical spelling route) and also varying various attributes of the individual kanji characters of which the whole-word spelling was composed (any effect of such a subword attribute would indicate the use of the sublexical spelling route). Results: Their spelling performance was influenced by imageability and familiarity (indicating that they were using a lexical kanji spelling route) and also by single-character consistency (indicating that they were also using a sublexical kanji spelling route). Conclusion: The children had learned to spell words in kanji using both lexical and sublexical routes