The phosphatase interactor NIPP1 regulates the occupancy of the histone methyltransferase EZH2 at Polycomb targets

Polycomb group (PcG) proteins are key regulators of stem-cell and cancer biology. They mainly act as repressors of differentiation and tumor-suppressor genes. One key silencing step involves the trimethylation of histone H3 on Lys27 (H3K27) by EZH2, a core component of the Polycomb Repressive Complex 2 (PRC2). The mechanism underlying the initial recruitment of mammalian PRC2 complexes is not well understood. Here, we show that NIPP1, a regulator of protein Ser/Thr phosphatase-1 (PP1), forms a complex with PP1 and PRC2 components on chromatin. The knockdown of NIPP1 or PP1 reduced the association of EZH2 with a subset of its target genes, whereas the overexpression of NIPP1 resulted in a retargeting of EZH2 from fully repressed to partially active PcG targets. However, the expression of a PP1-binding mutant of NIPP1 (NIPP1m) did not cause a redistribution of EZH2. Moreover, mapping of the chromatin binding sites with the DamID technique revealed that NIPP1 was associated with multiple PcG target genes, including the Homeobox A cluster, whereas NIPP1m showed a deficient binding at these loci. We propose that NIPP1 associates with a subset of PcG targets in a PP1-dependent manner and thereby contributes to the recruitment of the PRC2 complex

The protein phosphatase 1 regulator NIPP1 is essential for mammalian spermatogenesis

NIPP1 is one of the major nuclear interactors of protein phosphatase PP1. The deletion of NIPP1 in mice is early embryonic lethal, which has precluded functional studies in adult tissues. Hence, we have generated an inducible NIPP1 knockout model using a tamoxifen-inducible Cre recombinase transgene. The inactivation of the NIPP1 encoding alleles (Ppp1r8) in adult mice occurred very efficiently in testis and resulted in a gradual loss of germ cells, culminating in a Sertoli-cell only phenotype. Before the overt development of this phenotype Ppp1r8 -/- testis showed a decreased proliferation and survival capacity of cells of the spermatogenic lineage. A reduced proliferation was also detected after the tamoxifen-induced removal of NIPP1 from cultured testis slices and isolated germ cells enriched for undifferentiated spermatogonia, hinting at a testis-intrinsic defect. Consistent with the observed phenotype, RNA sequencing identified changes in the transcript levels of cell-cycle and apoptosis regulating genes in NIPP1-depleted testis. We conclude that NIPP1 is essential for mammalian spermatogenesis because it is indispensable for the proliferation and survival of progenitor germ cells, including (un)differentiated spermatogonia.publishe

Co-morbid depression is associated with poor work outcomes in persons with cardiovascular disease (CVD): A large, nationally representative survey in the Australian population

Background: Co-morbid major depressive disorder (MDD) and cardiovascular disease (CVD) is associated with poor clinical and psychological outcomes. However, the full extent of the burden of, and interaction between, this co-morbidity on important vocational outcomes remains less clear, particularly at the population level. We examine the association of co-morbid MDD with work outcomes in persons with and without CVD.Methods. This study utilised cross-sectional, population-based data from the 2007 Australian National Survey of Mental Health and Wellbeing (n = 8841) to compare work outcomes of individuals with diagnostically-defined MDD and CVD, MDD but not CVD, CVD but not MDD, with a reference group of "healthy" Australians. Workforce participation was defined as being in full- or part-time employment. Work functioning was measured using a WHO Disability Assessment Schedule item. Absenteeism was assessed using the \u27days out of role\u27 item.Results: Of the four groups, those with co-morbid MDD and CVD were least likely to report workforce participation (adj OR:0.4, 95% CI: 0.3-0.6). Those with MDD only (adj OR:0.8, 95% CI:0.7-0.9) and CVD only (adj OR:0.8, 95% CI: 0.6-0.9) also reported significantly reduced odds of participation. Employed individuals with co-morbid MDD and CVD were 8 times as likely to experience impairments in work functioning (adj OR:8.1, 95% CI: 3.8- 17.3) compared with the reference group. MDD was associated with a four-fold increase in impaired functioning. Further, individuals with co-morbid MDD and CVD reported greatest likelihood of workplace absenteeism (adj. OR:3.0, 95% CI: 1.4-6.6). Simultaneous exposure to MDD and CVD conferred an even greater likelihood of poorer work functioning.Conclusions: Co-morbid MDD and CVD is associated with significantly poorer work outcomes. Specifically, the effects of these conditions on work functioning are synergistic. The development of specialised treatment programs for those with co-morbid MDD and CVD is required

Health-related quality of life after fast-track treatment results from a randomized controlled clinical equivalence trial

Purpose This randomized clinical equivalence trial was designed to evaluate health-related quality of life (HRQoL) after fast-track treatment for low-risk coronary artery bypass (CABG) patients. Methods Four hundred and ten CABG patients were randomly assigned to undergo either short-stay intensive care treatment (SSIC, 8 h of intensive care stay) or control treatment (care as usual, overnight intensive care stay). HRQoL was measured at baseline and 1 month, and one year after surgery using the multidimensional index of life quality (MILQ), the EQ-5D, the Beck Depression Inventory and the State-Trait Anxiety Inventory. Results At one month after surgery, no statistically significant difference in overall HRQoL was found (MILQ-score P-value = .508, overall MILQ-index P-value = .543, EQ-5D VAS P-value = .593). The scores on the MILQ-domains, physical, and social functioning were significantly higher at one month postoperatively in the SSIC group compared to the control group (P-value = .049; 95% CI: 0.01-2.50 and P-value =.014, 95% CI:0.24-2.06, respectively). However, these differences were no longer observed at long-term follow-up. Conclusions According to our definition of clinical equivalence, the HRQoL of SSIC patients is similar to patients receiving care as usual. Since safety and the financial benefits of this intervention were demonstrated in a previously reported analysis, SSIC can be considered as an adequate fast-track intensive care treatment option for low-risk CABG patients

Rookreductie versus abrupte rookstop

Bespreking van: Lindson-Hawley N, Aveyard P, Hughes JR. Reduction versus abrupt cessation in smokers who want to quit. Cochrane Database Syst Rev 2012, Issue 1