CRISPR-Knockout Screen Identifies Dmap1 as a Regulator of Chemically Induced Reprogramming and Differentiation of Cardiac Progenitors.

Direct in vivo reprogramming of cardiac fibroblasts into myocytes is an attractive therapeutic intervention in resolving myogenic deterioration. Current transgene-dependent approaches can restore cardiac function, but dependence on retroviral delivery and persistent retention of transgenic sequences are significant therapeutic hurdles. Chemical reprogramming has been established as a legitimate method to generate functional cell types, including those of the cardiac lineage. Here, we have extended this approach to generate progenitor cells that can differentiate into endothelial cells and cardiomyocytes using a single inhibitor protocol. Depletion of terminally differentiated cells and enrichment for proliferative cells result in a second expandable progenitor population that can robustly give rise to myofibroblasts and smooth muscle. Deployment of a genome-wide knockout screen with clustered regularly interspaced short palindromic repeats-guide RNA library to identify novel mediators that regulate the reprogramming revealed the involvement of DNA methyltransferase 1-associated protein 1 (Dmap1). Loss of Dmap1 reduced promoter methylation, increased the expression of Nkx2-5, and enhanced the retention of self-renewal, although further differentiation is inhibited because of the sustained expression of Cdh1. Our results hence establish Dmap1 as a modulator of cardiac reprogramming and myocytic induction. Stem Cells 2019;37:958-972.

Unraveling the Developmental Roadmap toward Human Brown Adipose Tissue.

Increasing brown adipose tissue (BAT) mass and activation is a therapeutic strategy to treat obesity and complications. Obese and diabetic patients possess low amounts of BAT, so an efficient way to expand their mass is necessary. There is limited knowledge about how human BAT develops, differentiates, and is optimally activated. Accessing human BAT is challenging, given its low volume and anatomical dispersion. These constraints make detailed BAT-related developmental and functional mechanistic studies in humans virtually impossible. We have developed and characterized functionally and molecularly a new chemically defined protocol for the differentiation of human pluripotent stem cells (hPSCs) into brown adipocytes (BAs) that overcomes current limitations. This protocol recapitulates step by step the physiological developmental path of human BAT. The BAs obtained express BA and thermogenic markers, are insulin sensitive, and responsive to ß-adrenergic stimuli. This new protocol is scalable, enabling the study of human BAs at early stages of development.

Gene control in germinal differentiation: RNF6, a transcription regulatory protein in the mouse sertoli cell.

In mouse Sertoli cells, transcription of the Inha gene encoding the alpha subunit of inhibin, which acts locally as a tumor suppressor, is down-regulated in tumors and in normal cells during aging. Previous studies suggested that regulation of Inha transcription involves the binding of a protein(s) to a repeat of the GGGGC motif in the promoter. Expression screening identified a cDNA encoding a protein that binds this sequence. Of the RING-H2 family, it is the mouse homologue of a human protein of unknown function, RNF6. The mouse gene, Rnf6, is predominantly expressed in two interacting cell types of the testis, Sertoli cells and pachytene spermatocytes. In Sertoli cells, it colocalizes with the PML and Daxx proteins in punctate nuclear bodies. In transient and stable transfectants, Rnf6 expression from a heterologous promoter increased the expression of reporter genes driven by the Inha promoter. In a Sertoli tumor cell line in which expression of both Inha and Rnf6 was reduced, reexpression of the latter restored the level of Inha while, concomitantly, the cells reverted to normal growth control in culture.

A position paper on how cost and quality reforms are changing healthcare in America: focus on nutrition.

Healthcare spending in the United States is the highest in the world, yet quality indicators such as life expectancy and infant mortality lag other countries. U.S. reforms are under way to lower costs and raise quality of care, notably the Patient Protection and Affordable Care Act (PPACA). Value-based purchasing (VBP) and programs for reducing the incidence of hospital-acquired conditions (HACs) and hospital readmissions represent initial changes. With these programs, overarching themes are to coordinate care during and beyond hospitalization and to ensure that physicians and hospitals are aligned in their treatment strategies. Hospital malnutrition represents a large, hidden, and costly component of medical care; hospital administrators and caregivers alike must harness the benefits of nutrition as a vital component of healthcare. Medical, nursing, and allied health training programs must find places in their curricula to increase awareness of nutrition and promote knowledge of best-practice nutrition interventions. Hospitals use dietitians and nutrition support teams as critical members of the patient care team, but more work needs to be done to disseminate and enforce best nutrition practices. Such training, nutrition interventions, and practice changes can help prevent and treat malnutrition and thus help avert HACs, reduce hospital readmissions, lower infection and complication rates, and shorten hospital stays. Nutrition care is an effective way to reduce costs and improve patient outcomes. This article calls hospital executives and bedside clinicians to action: recognize the value of nutrition care before, during, and after hospitalization, as well as develop training programs and policies that promote nutrition care.