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Emerging structural insights into PRC2 function in development and disease

Structural insights into PRC2 function in development and disease.

Polycomb repressive complex 2 (PRC2) is a central epigenetic regulator of developmental gene repression that displays remarkable complexity arising from multiple molecular layers.

Enzyme catalysis and chromatin targeting form the basis of the common and distinct functions of PRC2.1 and PRC2.2, serving as focal points in the cellular regulation of PRC2 activity under both physiological and pathological contexts.

Structural biology has begun to clarify the molecular mechanisms underlying key functions of PRC2 and uncover new modes of regulation, with much still remaining to be understood about the elaborate system of PRC2-mediated gene control. https://sciencemission.com/PRC2-function-in-development-and-disease


Polycomb repressive complex 2 (PRC2) is a key epigenetic enzyme complex that mediates developmental gene repression mainly by depositing the repressive H3K27me3 histone mark. PRC2 operates through its distinct forms, PRC2.1 and PRC2.2, each defined by unique accessory subunits, with additional complexity introduced by other molecular variants such as developmentally regulated homologs and isoforms. PRC2 function is primarily dictated by its enzymatic activity and chromatin recruitment, both of which are rigorously controlled during development and can be dysregulated by disease-associated mutations and oncoproteins. Structural biology has begun to provide important mechanistic insights into various aspects of PRC2 assembly, catalysis, chromatin targeting, and cellular regulation at atomic resolution, addressing several longstanding questions about the Polycomb repression system.

Detrimental Effect of Plasma From Patients With Severe Aortic Stenosis on Valvular Endothelial Cells: Role of Proinflammatory Cytokines and Factor Xa

Severe AS plasma is pro-inflammatory and pro-thrombotic: it drives oxidative stress + endothelial dysfunction + monocyte/platelet adhesion in VECs. Multiple drug classes blunted these effects. @A_Trimaille @adrien_carmona @BMarchandot


Aortic stenosis (AS) is the most prevalent valvular heart disease in developed countries.1 Despite its widespread occurrence, no medical treatment has been validated to prevent the thickening of the aortic valve and the reduction in its opening area. The only available therapeutic option to date remains surgical or transcatheter aortic valve replacement once the severity criteria are met.2, 3 A comprehensive understanding of AS pathophysiology is therefore essential for identifying new therapeutic targets.

Initially thought to be a passive degenerative process, AS is now recognized as an active, multifaceted condition involving numerous cellular and molecular contributors.1, 4 The progression of AS follows a chronological sequence, beginning with the damage and dysfunction of valvular endothelial cells (VECs) due to biomechanical forces acting on the aortic valve. This damage promotes intravalvular inflammation and neoangiogenesis, followed by myofibroblastic and osteoblastic differentiation of valvular interstitial cells. Additionally, several lines of evidence suggest a bidirectional interaction between the pathomechanisms of AS and various components of the hemostatic system, including platelets, tissue factor, thrombin, von Willebrand factor, and extracellular vesicles.4, 5, 6

Given the pivotal role of VECs in maintaining valvular homeostasis under physiological conditions, and their early involvement in AS pathogenesis, they are considered key actors in the disease process. Although biomechanical factors have been identified as primary triggers of VEC dysfunction in the early stage of AS,4 the molecular mechanisms underlying the interaction between plasma from patients with AS and aortic VECs remain unclear. Because plasma contains various biological effectors potentially contributing to endothelial cell dysfunction, including proinflammatory cytokines and hemostatic factors,4, 7 this study aimed to investigate whether plasma from patients with AS induces oxidative stress and contributes to VEC dysfunction.

HSV1716 Prevents Myeloma Cell Regrowth When Combined with Bortezomib In Vitro and Significantly Reduces Systemic Tumor Growth in Mouse Models

Multiple myeloma remains largely incurable due to refractory disease; therefore, novel treatment strategies that are safe and well-tolerated are required.

A Red Blood Cell Protein Turns Dendritic Cells Tolerant

The immune system uses regulatory T cells to dampen inflammatory responses. However, the mechanism that led to these tolerant cells was unclear.

Now, a team of researchers showed that the trigger lies in a protein used in red blood cell production.

Read more.

Erythropoietin, the protein that drives red blood cell formation, also induces tolerance in dendritic cells, leading to the development of regulatory T cells.

Abstract: For those interested in fertility regulation, endometriosis, adenomyosis, and endometrial cancer…

Francesco J. DeMayo & team discover uterine ZMIZ1 co-regulates estrogen receptor to establish and maintain pregnancy and general uterine health via cell growth responses and preventing uterine fibrosis:

The figure shows epithelial cell DNA synthesis (reflected by EdU incorporation) was inhibited by Zmiz1 deletion.


1Pregnancy & Female Reproduction Group, Reproductive and Development al Biology Lab, NIEHS, Research Triangle Park, North Carolina, USA.

2Inotiv-RTP, Durham, North Carolina, USA.

3Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, USA.

Plant used in folk medicine has anti-inflammatory anti-arthritic effects, study confirms

In Brazil, researchers from the Federal University of Grande Dourados (UFGD), the State University of Campinas (UNICAMP), and São Paulo State University (UNESP) have conducted a study that confirmed the safety and anti-inflammatory, analgesic, and anti-arthritic properties of the Joseph’s Coat plant (Alternanthera littoralis).

Native to the Brazilian coast, this plant has been used in folk medicine to combat inflammation, microbial infections, and parasitic diseases. Until now, there has been little pharmacological evidence to support these applications or analyze their safety.

The study is published in the Journal of Ethnopharmacology.

PreTA-mediated metabolism of 5-fluorouracil by intratumoral Citrobacter freundii drives chemoresistance in pancreatic cancer

Xu et al. report that intratumoral Citrobacter enrichment correlates with poor overall survival in pancreatic cancer patients. An intratumoral Citrobacter freundii strain metabolizes 5-fluorouracil (5-FU) into inactive products via PreTA. Gimeracil, an inhibitor of human dihydropyrimidine dehydrogenase, preserves 5-FU efficacy by blocking PreTA activity.

Targeting Human Proteins for Antiviral Drug Discovery and Repurposing Efforts: A Focus on Protein Kinases

Despite the great technological and medical advances in fighting viral diseases, new therapies for most of them are still lacking, and existing antivirals suffer from major limitations regarding drug resistance and a limited spectrum of activity. In fact, most approved antivirals are directly acting antiviral (DAA) drugs, which interfere with viral proteins and confer great selectivity towards their viral targets but suffer from resistance and limited spectrum. Nowadays, host-targeted antivirals (HTAs) are on the rise, in the drug discovery and development pipelines, in academia and in the pharmaceutical industry. These drugs target host proteins involved in the virus life cycle and are considered promising alternatives to DAAs due to their broader spectrum and lower potential for resistance.

AI identifies key mpox protein for new vaccine and antibody therapies

With the help of artificial intelligence, an international team of researchers has made the first major inroad to date toward a new and more effective way to fight the monkeypox virus (MPXV), which causes a painful and sometimes deadly disease that can be especially dangerous for children, pregnant women and immunocompromised people.

Reporting in the journal Science Translational Medicine, the team found that when mice were injected with a viral surface protein recommended by AI, the animals produced antibodies that neutralized MPXV, suggesting the breakthrough could be used in a new mpox vaccine or antibody therapy.

In 2022, mpox began to spread around the world, causing flulike symptoms and painful rashes and lesions for more than 150,000 people, while causing almost 500 deaths. Vaccines developed to fight smallpox were repurposed amid the outbreak to help the most vulnerable patients, but that vaccine is complicated and costly, due to its manufacture from a whole, weakened virus.

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