DNA methylation at imprinting control regions (ICRs) is established in gametes in a sex-specific manner and has to be stably maintained during development and in somatic cells to ensure the correct ...monoallelic expression of imprinted genes. In addition to DNA methylation, the ICRs are marked by allele-specific histone modifications. Whether these marks are essential for maintenance of genomic imprinting is largely unclear. Here, we show that the histone H3 lysine 9 methylases G9a and GLP are required for stable maintenance of imprinted DNA methylation in embryonic stem cells; however, their catalytic activity and the G9a/GLP-dependent H3K9me2 mark are completely dispensable for imprinting maintenance despite the genome-wide loss of non-imprinted DNA methylation in H3K9me2-depleted cells. We provide additional evidence that the G9a/GLP complex protects imprinted DNA methylation by recruitment of de novo DNA methyltransferases, which antagonize TET dioxygenass-dependent erosion of DNA methylation at ICRs.
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•ESCs lacking G9a and GLP display loss of DNA methylation from ICRs•The enzymatic activity of G9a/GLP is dispensable for imprinted DNA methylation•G9a/GLP stabilize imprinting by recruitment of de novo DNA methyltransferases to ICRs•Recruitment of DNMTs to ICRs antagonizes TET-dependent loss of DNA methylation
Loss of allele-specific DNA methylation from imprinting control regions leads to unbalanced gene expression and disease. Here, Zhang et al. show that the KMT enzymes G9a and GLP stabilize imprinted DNA methylation in embryonic stem cells by recruitment of de novo DNA methyltransferase enzymes, which counteract TET dioxygenase-dependent demethylation pathways.
Non-centrosomal microtubule organizing centers (MTOCs) are important for microtubule organization in many cell types. In fission yeast
, the protein Mto1, together with partner protein Mto2 (Mto1/2 ...complex), recruits the γ-tubulin complex to multiple non-centrosomal MTOCs, including the nuclear envelope (NE). Here, we develop a comparative-interactome mass spectrometry approach to determine how Mto1 localizes to the NE. Surprisingly, we find that Mto1, a constitutively cytoplasmic protein, docks at nuclear pore complexes (NPCs), via interaction with exportin Crm1 and cytoplasmic FG-nucleoporin Nup146. Although Mto1 is not a nuclear export cargo, it binds Crm1 via a nuclear export signal-like sequence, and docking requires both Ran in the GTP-bound state and Nup146 FG repeats. In addition to determining the mechanism of MTOC formation at the NE, our results reveal a novel role for Crm1 and the nuclear export machinery in the stable docking of a cytoplasmic protein complex at NPCs.
Tumourigenic transformation of normal cells into cancer typically involves several steps resulting in acquisition of unlimited growth potential, evasion of apoptosis and non-responsiveness to growth ...inhibitory signals. Both genetic and epigenetic changes can contribute to cancer development and progression. Given the vast genetic heterogeneity of human cancers and difficulty to monitor cancer-initiating events in vivo, the precise relationship between acquisition of genetic mutations and the temporal progression of epigenetic alterations in transformed cells is largely unclear. Here, we use an in vitro model system to investigate the contribution of cellular immortality and oncogenic transformation of primary human cells to epigenetic reprogramming of DNA methylation and gene expression. Our data demonstrate that extension of replicative life span of the cells is sufficient to induce accumulation of DNA methylation at gene promoters and large-scale changes in gene expression in a time-dependent manner. In contrast, continuous expression of cooperating oncogenes in immortalized cells, although essential for anchorage-independent growth and evasion of apoptosis, does not affect de novo DNA methylation at promoters and induces subtle expression changes. Taken together, these observations imply that cellular immortality promotes epigenetic adaptation to highly proliferative state, whereas transforming oncogenes confer additional properties to transformed human cells.
Background Calcodynia is a persistent condition that podiatric surgeons frequently see among their patients, and plantar fasciitis is the main reason for pain. When systematic conservative treatments ...fail to alleviate these conditions, it requires surgical intervention, mainly plantar fascia release surgery, which used to be an open heel release surgery. This study aimed to investigate whether minimally invasive treatment of the KobyGard system is more safe and effective for plantar fasciitis. Methods From May 2009 to May 2012, a total of nine patients, three males and six females with plantar fasciitis, were treated in the Peking University People＇s Hospital with minimally invasive instruments, the KobyGard system, for the release of plantar fascia. Three patients, experiencing bilateral calcaneodynia, underwent bilateral surgery. One patient had bilateral calcaneodynia with enthesiopathy of Achilles tendon, and underwent Achilles tendon surgery. Preoperative and postoperative Visual Analogue Scale （VAS）, American Orthopaedic Foot and Ankle Society （AOFAS） ankle and hindfoot scores, Roles and Maudsley scores and SF-36 questionnaires were evaluated. Results The nine patients were successfully followed up. The average postoperative follow-up time was 13.2 months and it varied from 2.0 months to 21.0 months. Pre- and postoperative average scores of VAS was 9.3 and 1.9 （P 〈0.001）, respectively. Pre- and postoperative average scores of AOFAS hind foot was 36.0 and 82.0 （P 〈0.001）, respectively. There was also a statistically significant amelioration in SF-36 scores and the Roles and Maudlesy scores. Eight patients were satisfied with the surgery outcome. Conclusion Minimally invasive surgery treatment of the KobyGard system for plantar fasciitis has the advantages of shorter operation time, ease of operation, and similar satisfaction rates with open surgery, but with smaller surgical incision.
Background For some specific comminuted unstable intra-articular fracture,the plaster cast can not maintain the alignment of the articular surface effectively.The aim of this study was to evaluate ...the clinical effects of distal radius fracture treated with open reduction and internal plate fixation retrospectively.Methods From January 2002 to March 2010,539 cases of distal radius fracture were treated with open reduction and internal fixation,including 184 males and 355 females aging 21-72 years （mean 57 years）.Fractures were caused by falling to the ground in 459 cases,by traffic accident in 62 cases and by athletic injuries in 18 cases.Of 539 cases,there were 523 cases of closed fracture and 16 cases of open fracture.According to Arbeitsgemeinschaft fur Osteosynthesefragen （AO） standards of classification,there were 14 cases of A2 type,22 of A3 type,18 of B1 type,24 of B2 type,62 of B3 type,91 of C1 type,162 of C2 type and 146 of C3 type.The time from injury to operation was 1-16 days （mean 5 days）.All patitents received open reduction and internal plate screw fixation.Forty-seven patients with bone defect were given 6-15 g autologous ilium and 75 cases were given 5 ml calcium sulphate artificial aggregate after reduction.Results All incisions healed by first intention after operation.Patients were followed up for 15 to 32 months postoperatively （mean 22 months）.The fractures healed within 10-18 weeks after operation （mean 12 weeks）.During the last follow-up,the mean palmar tilt was （7.0±0.9）° and the mean ulnar variance was （21.0±4.2）°,showing significant difference when compared with preoperation （（-5.0±1.2）° and （8.0±3.8）°）.The radial heights were not abbreviated.According to Gartland and Werley assessment system,the results were excellent in 314 cases,good in 163 cases,fair in 46 cases,and poor in 16 cases 12 weeks after operation,the excellent and good rate was 88.5%.Conclusions The clinical effect of distal radius fracture treated with open reduction and internal plate fixation was relatively satisfactory.Meticulous operation procedure and individual rehabilitation strategy contribute to the wrist joint functional recovery.
Background. Seven persons in one family living in eastern China developed fever and thrombocytopenia during May 2007, but the initial investigation failed to identify an infectious etiology. In ...December 2009, a novel bunyavirus (designated severe fever with thrombocytopenia syndrome bunyavirus SFTSV) was identified as the cause of illness in patients with similar clinical manifestations in China. We reexamined this family cluster for SFTSV infection. Methods. We analyzed epidemiological and clinical data for the index patient and 6 secondary patients. We tested stored blood specimens from the 6 secondary patients using real time reverse transcription polymerase chain reaction (RT-PCR), viral culture, genetic sequencing, micro-neutralization assay (MNA), and indirect immunofluorescence assay (IFA). Results. An 80-year-old woman with fever, leucopenia, and thrombocytopenia died on 27 April 2007. Between 3 and 7 May 2007, another 6 patients from her family were admitted to a local county hospital with fever and other similar symptoms. Serum specimens collected in 2007 from these 6 patients were positive for SFTS viral RNA through RT-PCR and for antibody to SFTSV through MNA and IFA. SFTSV was isolated from 1 preserved serum specimen. The only shared characteristic between secondary patients was personal contact with the index patient; none reported exposure to suspected animals or vectors. Conclusions. Clinical and laboratory evidence confirmed that the patients of fever and thrombocytopenia occurring in a family cluster in eastern China in 2007 were caused by a newly recognized bunyavirus, SFTSV. Epidemiological investigation strongly suggests that infection of secondary patients was transmitted to family members by personal contact.
Mixing or regrouping of calves from different pens is a common animal management practice on the farm, which frequently occurs after weaning and has a negative effect on calve welfare. Social ...integration before regrouping may relieve stresses, but more evidences are needed to verify this hypothesis. The present study aimed to investigate acute physiological and behavioral variations of individually- or group-housed calves after being introduced into a mixed group. A total of 132 postnatal calves were randomly divided into groups of 1, 3, 6 and 12 animals (S, G3, G6, and G12; 6 replicates in each group) until 59 days of age. At 60 days of age, every two replicates from different groups (S, G3, G6 and G12) were introduced in a larger pen which containing 44 of the aboved experimental calves. Before and after regrouping, physiological parameters of stress, including heart rate (HR), saliva cortisol (S-CORT), saliva secretory immunoglobulin A (SIgA), interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) levels, and behavioral responses were recorded. After regrouping, HR and S-CORT increased immediately (P<0.05), and higher (P<0.05) levels of such molecules were found in S calves compared to those in group-housed calves. Levels of SIgA and IL-2 were decreased (P<0.05), and the lowest (P<0.05) IL-2 values were found in S calves compared to those in group-housed calves. In addition, the introduced calves displayed a distinct behavior, including altered active and rest time, which was associated with negative emotions triggered by the novel surroundings. Allogrooming, play, exploration behaviors and lying time were increased significantly (P<0.05) in group-housed calves than those in S calves. Conversely, self-grooming, aggressive behaviors, standing and walking time were increased (P<0.05) in S calves than those in group-housed calves. These findings suggest that individually-housed calves may be more susceptible to stressors arising from regrouping than group-housed calves, which consequently negatively affected behavioral and neuroendocrine responses. Furthermore, moving calves with previous social experience may help mitigate regrouping stress.
The objective of this study was to compare the treatment results of low-pressure pneumoperitoneum with abdominal wall lifting (AWL+LP, 6 mm Hg) versus standard pressure pneumoperitoneum (SP, 12 mm ...Hg) during laparoscopic fundoplication for gastroesophageal reflux disease (GERD), using propensity score matching (PSM).
A retrospective analysis was made of 362 patients, 123 in the AWL+LP group and 239 in the SP group, who underwent laparoscopic fundoplication for GERD from January 2010 to December 2017. Perioperative and prognostic outcomes were compared after PSM with 1:1 match.
After PSM, 107 matched pairs were obtained. Compared with the SP group at 30 and 60 minutes after pneumoperitoneal initiation, the AWL+LP group showed significantly lower end-tidal carbon dioxide value (P<0.001, <0.001, respectively), lower partial pressure of carbon dioxide value (P<0.001, 0.016, respectively) and significantly higher pH value (P<0.001, <0.001, respectively). However, postoperative shoulder pain, abdominal pain, and arrhythmia in the AWL+LP group were less than those in SP group (P=0.01, 0.017, 0.005, respectively). There was no significant difference in operative time (106.54±27.80 vs. 107.38±24.78 min), blood loss 15 mL (interquartile range: 12.5 to 20 mL) vs.15 mL (interquartile range: 10 to 20 mL), length of stay (4 vs. 4 d), the wound ecchymosis 2 (1.87%) vs. 3 (2.80%) and rates of recurrence 8 (7.48%) vs. 5 (4.67%) between AWL+LP group and SP group.
AWL+LP resulted in comparable perioperative and prognostic outcomes with less impact on changes in cardiorespiratory function compared with SP approaches of laparoscopic fundoplication for GERD.
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