Defining Hypo-Methylated Regions of Stem Cell-Specific Promoters in Human iPS Cells Derived from Extra-Embryonic Amnions and Lung Fibroblasts

BACKGROUND: Human induced pluripotent stem (iPS) cells are currently used as powerful resources in regenerative medicine. During very early developmental stages, DNA methylation decreases to an overall low level at the blastocyst stage, from which embryonic stem cells are derived. Therefore, pluripotent stem cells, such as ES and iPS cells, are considered to have hypo-methylated status compared to differentiated cells. However, epigenetic mechanisms of "stemness" remain unknown in iPS cells derived from extra-embryonic and embryonic cells. METHODOLOGY/PRINCIPAL FINDINGS: We examined genome-wide DNA methylation (24,949 CpG sites covering 1,3862 genes, mostly selected from promoter regions) with six human iPS cell lines derived from human amniotic cells and fetal lung fibroblasts as well as two human ES cell lines, and eight human differentiated cell lines using Illumina's Infinium HumanMethylation27. A considerable fraction (807 sites) exhibited a distinct difference in the methylation level between the iPS/ES cells and differentiated cells, with 87.6% hyper-methylation seen in iPS/ES cells. However, a limited fraction of CpG sites with hypo-methylation was found in promoters of genes encoding transcription factors. Thus, a group of genes becomes active through a decrease of methylation in their promoters. Twenty-three genes including SOX15, SALL4, TDGF1, PPP1R16B and SOX10 as well as POU5F1 were defined as genes with hypo-methylated SS-DMR (Stem cell-Specific Differentially Methylated Region) and highly expression in iPS/ES cells. CONCLUSIONS/SIGNIFICANCE: We show that DNA methylation profile of human amniotic iPS cells as well as fibroblast iPS cells, and defined the SS-DMRs. Knowledge of epigenetic information across iPS cells derived from different cell types can be used as a signature for "stemness" and may allow us to screen for optimum iPS/ES cells and to validate and monitor iPS/ES cell derivatives for human therapeutic applications

High serum growth differentiation factor 15 is a risk factor for the occurrence of hepatocellular carcinoma in chronic hepatitis B patients treated with nucleos(t)ide analogs

Sometani E., Hikita H., Murai K., et al. High serum growth differentiation factor 15 is a risk factor for the occurrence of hepatocellular carcinoma in chronic hepatitis B patients treated with nucleos(t)ide analogs. Hepatology Research, (2024); https://doi.org/10.1111/hepr.14111.Aim: Patients with chronic hepatitis B (CHB) remain at risk for hepatocellular carcinoma (HCC) even with nucleos(t)ide analog therapy. We evaluated risk factors for HCC development, including serum hepatitis B virus (HBV) RNA, hepatitis B core-related antigen level, and growth differentiation factor 15 (GDF15) level, a predictor of HCC development in patients with chronic hepatitis C. Methods: We collected clinical data and stored serum from CHB patients without a history of HCC who were receiving nucleos(t)ide analog treatment for more than 1 year and whose HBV DNA level was less than 3.0 log IU/mL. We measured the serum levels of HBV RNA and GDF15. Results: Among 242 CHB patients, 57 had detectable HBV RNA, and GDF15 was quantified in all patients. The median GDF15 level was 0.86 ng/mL. Cox proportional hazards analysis revealed that male sex and higher GDF15, FIB-4 index, alpha-fetoprotein and gamma-glutamyl transpeptidase were independent risk factors for HCC. The presence of HBV RNA above the lower limit of quantification was not a risk factor. When we set cutoff values based on the Youden index, the cumulative incidence of HCC was significantly higher in the male, AFP ≥3.0 ng/mL, gamma-glutamyl transpeptidase ≥22 U/L, FIB-4 index ≥1.93, and GDF-15 ≥1.17 ng/mL groups. In patients with no or more than three of these five risk factors, the 10-year HCC cumulative incidence rates were 0% and 41.0%, respectively. Conclusions: High serum GDF15 is an independent risk factor for the occurrence of HCC in CHB patients treated with nucleos(t)ide analogs

DNA Methylation Dynamics in Human Induced Pluripotent Stem Cells over Time

Epigenetic reprogramming is a critical event in the generation of induced pluripotent stem cells (iPSCs). Here, we determined the DNA methylation profiles of 22 human iPSC lines derived from five different cell types (human endometrium, placental artery endothelium, amnion, fetal lung fibroblast, and menstrual blood cell) and five human embryonic stem cell (ESC) lines, and we followed the aberrant methylation sites in iPSCs for up to 42 weeks. The iPSCs exhibited distinct epigenetic differences from ESCs, which were caused by aberrant methylation at early passages. Multiple appearances and then disappearances of random aberrant methylation were detected throughout iPSC reprogramming. Continuous passaging of the iPSCs diminished the differences between iPSCs and ESCs, implying that iPSCs lose the characteristics inherited from the parent cells and adapt to very closely resemble ESCs over time. Human iPSCs were gradually reprogrammed through the “convergence” of aberrant hyper-methylation events that continuously appeared in a de novo manner. This iPS reprogramming consisted of stochastic de novo methylation and selection/fixation of methylation in an environment suitable for ESCs. Taken together, random methylation and convergence are driving forces for long-term reprogramming of iPSCs to ESCs

Three types of proteinases in Japanese common squid Todarodes pacificus hepatopancreas as studied by using carp myofibrils as substrate

Three types of proteinases, namely cysteine-, metallo-, and serine-proteinases, were found in squid hepatopancreas by studying the inhibition spectra using carp myofibril as substrate. The cysteine-, metallo-, and serine-types showed the highest activities at 50℃, 35℃, and 40℃, respectively. The optimal pHs were pH 5, pH 7, and pH 9 for the cysteine-, metallo-, and serine-types, respectively. When assayed at 20℃ and pH 7.5, the metallo-type showed the highest activity. The metallo-type was characterized by a high selectivity in the digestion of myosin. Among the three enzymes, the cysteine-type was found to be the most stable against thermal and acid treatments. Heat treated myofibrils were more susceptible to cysteine- and serine-types, but less susceptible to the metallo-type. Acid treatment of myofibrils also enhanced the digestibility by cysteine type. The results indicated that the cysteine-type seemed to be the most suitable enzyme to produce peptides from denatured myofibrils by their random digestion

Efficacy of interferential current transcutaneous electrical sensory stimulation through the neck skin for treating dysphagia in children with disabilities: A case series

Finding a suitable treatment for dysphagia has been challenging and the efficacy of neuromuscular electrical stimulation has been recognized. Moreover, the beneficial effect of interferential current transcutaneous electrical sensory stimulation has recently been described. However, the efficacy of interferential current transcutaneous electrical sensory stimulation in children with disabilities is unknown. Therefore, the aim of this study was to confirm the efficacy of interferential current transcutaneous electrical sensory stimulation in children with disabilities. Four children with disabilities of various types underwent interferential current transcutaneous electrical sensory stimulation once a week. All patients showed improved symptoms after interferential current transcutaneous electrical sensory stimulation treatment. Videoendoscopic examination showed reduced accumulation of secretion in all patients and decreased residual bolus in two. We also felt an increased forcefulness when swallowing in two. In addition, the questionnaire results regarding dysphagia indicated improvements. No significant side effects were observed. The interferential current transcutaneous electrical sensory stimulation treatment may be effective and safe in children with disabilities. The effect of this treatment on swallowing ability needs to be further investigated by studying more cases

sj-docx-1-sco-10.1177_2050313X221149527 – Supplemental material for Efficacy of interferential current transcutaneous electrical sensory stimulation through the neck skin for treating dysphagia in children with disabilities: A case series

Supplemental material, sj-docx-1-sco-10.1177_2050313X221149527 for Efficacy of interferential current transcutaneous electrical sensory stimulation through the neck skin for treating dysphagia in children with disabilities: A case series by Michinori Funato, Kanako Maruta, Mitsuru Yano, Mitsue Kai, Yaeko Umezawa, Kunihiko Yasuda, Emi Ohta-Noda and Keika Gen in SAGE Open Medical Case Reports</p