We report a fully defined synthetic polymer coating, poly[2-(methacryloyloxy)ethyl dimethyl-(3-sulfopropyl)ammonium hydroxide] (PMEDSAH), which sustains long-term human embryonic stem (hES) cell growth in several different culture media, including commercially available defined media. The development of a standardized, controllable and sustainable culture matrix for hES cells is an essential step in elucidating mechanisms that control hES cell behavior and in optimizing conditions for biomedical applications of hES cells.
Previous studies have demonstrated that patients with traumatic brain injury (TBI) who also have progressive hemorrhagic injury (PHI), have a higher risk of clinical deterioration and worse outcomes than do TBI patients without PHI. Therefore, the early prediction of PHI occurrence is useful to evaluate the status of patients with TBI and to improve outcomes. The objective of this study was to develop and validate a prognostic model that uses information available at admission to determine the likelihood of PHI after TBI. Retrospectively collected data were used to develop a PHI prognostic model with a logistic regression analysis. The prediction model was validated in 114 patients from a separate hospital. Eight independent prognostic factors were identified: age ‡ 57 years (5 points), intra-axial bleeding/brain contusion (4 points), midline shift ‡ 5 mm (6 points), platelet (PLT) count < 100 · 10 9 /L (10 points), PLT count ‡ 100 but < 150 · 10 9 /L (4 points), prothrombin time > 14 sec (7 points), D-dimer ‡ 5 mg/L (12 points), and glucose ‡ 10 mmol/L (10 points). Each patient was assigned a number of points proportional to the regression coefficient. We calculated risk scores for each patient and defined three risk groups: low risk (0-13 points), intermediate risk (14-22 points), and high risk (23-54 points). In the development cohort, the PHI rates after TBI for these three groups were 10.3%, 47.3%, and 85.2%, respectively. In the validation cohort, the corresponding PHI rates were 10.9%, 47.3%, and 86.9%. The C-statistic for the point system was 0.864 ( p = 0.509 by the Hosmer-Lemeshow test) in the development cohort, and 0.862 ( p = 0.589 by the Hosmer-Lemeshow test) in the validation cohort. In conclusion, a relatively simple risk score using admission predictors accurately predicted the risk for PHI after TBI.
Examination of factors regulating oocyte chromatin remodeling is crucial to circumvent embryonic aneuploidy and resulting defects. Aurora kinases (AURK) are involved in regulation of chromatin remodeling, however, little attention has been paid to AURKs in regard to oocyte maturation. Meiotically incompetent mouse oocytes contain transcripts for all three Aurk isoforms: A, B and C. Upon achieving meiotic competence, oocytes showed significant increases in transcript levels of all three Aurk isoforms and transcript levels remained unchanged as oocytes progressed through meiosis, with AurkA being the predominant isoform. Inhibition of oocyte AURKs during the prophase–metaphase I (MI) transition via inhibitor ZM447439 (ZM) had no effect on germinal vesicle breakdown. However, meiotic spindles were malformed, and microtubule organizing centers and chromatin were scattered. Chromosomal spreads of MI oocytes indicated AURK inhibition resulted in abnormal chromosome condensation. Furthermore, inhibition of AURK during prophase I–MII prevented completion of MII and extrusion of the polar body. Inhibition of AURKs during the MI–MII transition resulted in significantly fewer cells progressing to MII and induced aberrant chromatin remodeling. Further analysis indicated that inhibition of AURKs resulted in absence of histone-H3 phosphorylation at serine 10 and 28. These data suggest a ZM-sensitive AURK may be an oocyte histone-H3 kinase capable of regulating chromatin remodeling throughout oocyte meiosis, both pre- and post-MI.
During female reproductive life, ovarian follicle reserve is reduced by maturation and atresia until menopause ensues. Foxo3 is required to maintain the ovarian reserve in mice. Here we show that overexpression of constitutively active FOXO3 can increase ovarian reproductive capacity in mice. We find increased follicle numbers and decreased gonadotropin levels in aging FOXO3 transgenic mice compared to wild-type littermates, suggesting maintenance of a greater ovarian reserve. Based on cumulative progeny in aging animals, we find 31 to 49% increased fertility in transgenic females. The gene expression profile of Foxo3−/− knockout ovaries appears more mature than that of wild-type littermates, and the transgene induces a younger-looking profile, restoring much of the wild-type transcriptome. This is the first gain-of-function model of augmented reproductive reserve in mice, thus emphasizing the role of Foxo3 as a guardian of the ovarian follicle pool in mammals and a potential determinant of the onset of menopause.
Sirtuin 2 (SIRT2) is a member of the sirtuin family of NAD + -dependent protein deacetylases. In recent years, SIRT2 inhibition has emerged as a promising treatment for neurodegenerative diseases. However, to date, there is no evidence of a specific role for SIRT2 in traumatic brain injury (TBI). We investigated the effects of SIRT2 inhibition on experimental TBI using the controlled cortical impact (CCI) injury model. Adult male mice underwent CCI or sham surgery. A selective brain-permeable SIRT2 inhibitor, AK-7, was administrated 30 min before injury. The volume of the brain edema lesion and the water content of the brain were significantly increased in mice treated with AK-7 (20 mg/kg), compared with the vehicle group, following TBI (p < 0.05 at 1 day and p < 0.05 at 3 days, respectively). Concomitantly, AK-7 administration greatly worsened neurobehavioral deficits on days 3 and 7 after CCI. Furthermore, blood-brain barrier disruption and matrix metalloproteinases (MMP)-9 activity increased following SIRT2 inhibition. AK-7 treatment increased TBI-induced microglial activation both in vivo and in vitro, accompanied by a large increase in the expression and release of inflammatory cytokines. Mechanistically, SIRT2 inhibition increased both K310 acetylation and nuclear translocation of NF-jB p65, leading to enhanced NF-jB activation and up-regulation of its target genes, including aquaporin 4 (AQP4), MMP-9, and proinflammatory cytokines. Together, these data demonstrate that SIRT2 inhibition exacerbates TBI by increasing NF-jB p65 acetylation and activation. Our findings provide additional evidence of an anti-inflammatory effect of SIRT2. Keywords: blood-brain barrier, cerebral edema, inflammation, SIRT2, traumatic brain injury. Traumatic brain injury (TBI) involves a primary insult that occurs at the moment of impact that initiates subsequent physiological and pathological reactions that may last for days to months (Masel and DeWitt 2010). Despite recent advances in the understanding of the pathological process of TBI, an effective treatment that prevents or repairs TBI-induced loss-of-function remains to be discovered.
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