Generation of multipotent induced cardiac progenitor cells from mouse fibroblasts and potency testing in ex vivo mouse embryos

IL-27 promotes cardiac fibroblast activation and aggravates cardiac remodeling post myocardial infarction

Excessive and chronic inflammation post myocardial infarction (MI) causes cardiac fibrosis and progressive ventricular remodeling, which leads to heart failure. We previously found high levels of IL-27 in the heart and serum until day 14 in murine cardiac ischemia‒reperfusion injury models. However, whether IL-27 is involved in chronic inflammation-mediated ventricular remodeling remains unclear. In the present study, we found that MI triggered high IL-27 expression in murine cardiac macrophages. The increased expression of IL-27 in serum is correlated with cardiac dysfunction and aggravated fibrosis after MI. Furthermore, the addition of IL-27 significantly activated the JAK/STAT signaling pathway in cardiac fibroblasts (CFs). Meanwhile, IL-27 treatment promoted the proliferation, migration and extracellular matrix (ECM) production of CFs induced by angiotensin II (Ang II). Collectively, high levels of IL-27 mainly produced by cardiac macrophages post MI contribute to the activation of CFs and aggravate cardiac fibrosis.

Direct Reprogramming of Resident Non-Myocyte Cells and Its Potential for In Vivo Cardiac Regeneration

Cardiac diseases are the foremost cause of morbidity and mortality worldwide. The heart has limited regenerative potential; therefore, lost cardiac tissue cannot be replenished after cardiac injury. Conventional therapies are unable to restore functional cardiac tissue. In recent decades, much attention has been paid to regenerative medicine to overcome this issue. Direct reprogramming is a promising therapeutic approach in regenerative cardiac medicine that has the potential to provide in situ cardiac regeneration. It consists of direct cell fate conversion of one cell type into another, avoiding transition through an intermediary pluripotent state. In injured cardiac tissue, this strategy directs transdifferentiation of resident non-myocyte cells (NMCs) into mature functional cardiac cells that help to restore the native tissue. Over the years, developments in reprogramming methods have suggested that regulation of several intrinsic factors in NMCs can help to achieve in situ direct cardiac reprogramming. Among NMCs, endogenous cardiac fibroblasts have been studied for their potential to be directly reprogrammed into both induced cardiomyocytes and induced cardiac progenitor cells, while pericytes can transdifferentiate towards endothelial cells and smooth muscle cells. This strategy has been indicated to improve heart function and reduce fibrosis after cardiac injury in preclinical models. This review summarizes the recent updates and progress in direct cardiac reprogramming of resident NMCs for in situ cardiac regeneration.

Multi-functional gene ZNF281 identified as a molecular biomarker in soft tissue regeneration and pan-cancer progression

Regeneration and tumorigenesis are indicated as related processes, while regeneration leads to life and the outcome of tumorigenesis is death. Here, we show the upregulation of zfp281 (zinc finger 281) in our adipose de novo regeneration model through RNA-seq analysis. Then, we validated the upregulation of zfp281 in adipose regeneration via immunofluorescence. Following that, we found that ZNF281 (the human homolog of Zfp281) was upregulated in most types of cancer and related to worse prognosis in 10 tumors. We further investigated the role of ZNF281 in cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), pancreatic adenocarcinoma (PAAD), and stomach adenocarcinoma (STAD) and confirmed the high accuracy in the clinical diagnostic feature. Beyond that, based on these three types of cancers, we analyzed the ZNF281-related tumor immune infiltration and DNA methylation sites and finally built risk prediction models for future disease diagnosis. Taken together, our findings provide new insights into the dual role of ZNF281, and we found that it was a potential biomarker for regeneration and tumor prognosis.

Induced cardiac progenitor cells repopulate decellularized mouse heart scaffolds and differentiate to generate cardiac tissue

Native myocardium has limited regenerative potential post injury. Advances in lineage reprogramming have provided promising cellular sources for regenerative medicine in addition to research applications. Recently we have shown that adult mouse fibroblasts can be reprogrammed to expandable, multipotent, induced cardiac progenitor cells (iCPCs) by employing forced expression of five cardiac factors along with activation of canonical Wnt and JAK/STAT signaling. Here we aim to further characterize iCPCs by highlighting their safety, ease of attainability, and functionality within a three-dimensional cardiac extracellular matrix scaffold. Specifically, iCPCs did not form teratomas in contrast to embryonic stem cells when injected into immunodeficient mice. iCPC reprogramming was achieved in wild type mouse fibroblasts without requiring a cardiac-specific reporter, solely utilizing morphological changes to identify, clonally isolate, and expand iCPCs, thus increasing the versatility of this technology. iCPCs also show the ability to repopulate decellularized native heart scaffolds and differentiated into organized structures containing cardiomyocytes, smooth muscle, and endothelial cells. Optical mapping of recellularized scaffolds shows field-stimulated calcium transients that propagate across islands of reconstituted tissue and bipolar local stimulation demonstrates cell-cell coupling within scaffolds. Overall, iCPCs provide a readily attainable, scalable, safe, and functional cell source for a variety of application including drug discovery, disease modeling, and regenerative therapy.

The mouse fetal-placental arterial connection: A paradigm involving the primitive streak and visceral endoderm with implications for human development

In Placentalia, the fetus depends upon an organized vascular connection with its mother for survival and development. Yet, this connection was, until recently, obscure. Here, we summarize how two unrelated tissues, the primitive streak, or body axis, and extraembryonic visceral endoderm collaborate to create and organize the fetal-placental arterial connection in the mouse gastrula. The primitive streak reaches into the extraembryonic space, where it marks the site of arterial union and creates a progenitor cell pool. Through contact with the streak, associated visceral endoderm undergoes an epithelial-to-mesenchymal transition, contributing extraembryonic mesoderm to the placental arterial vasculature, and to the allantois, or pre-umbilical tissue. In addition, visceral endoderm bifurcates into the allantois where, with the primitive streak, it organizes the nascent umbilical artery and promotes allantoic elongation to the chorion, the site of fetal-maternal exchange. Brachyury mediates streak extension and vascular patterning, while Hedgehog is involved in visceral endoderm's conversion to mesoderm. A unique CASPASE-3-positive cell separates streak- and non-streak-associated domains in visceral endoderm. Based on these new insights at the posterior embryonic-extraembryonic interface, we conclude by asking whether so-called primordial germ cells are truly antecedents to the germ line that segregate within the allantois, or whether they are placental progenitor cells. Incorporating these new working hypotheses into mutational analyses in which the placentae are affected will aid understanding a spectrum of disorders, including orphan diseases, which often include abnormalities of the umbilical cord, yolk sac, and hindgut, whose developmental relationship to each other has, until now, been poorly understood. This article is categorized under: Birth Defects > Associated with Preimplantation and Gastrulation Early Embryonic Development > Gastrulation and Neurulation.

Direct Cardiac Reprogramming: Progress and Promise

The human adult heart lacks a robust endogenous repair mechanism to fully restore cardiac function after insult; thus, the ability to regenerate and repair the injured myocardium remains a top priority in treating heart failure. The ability to efficiently generate a large number of functioning cardiomyocytes capable of functional integration within the injured heart has been difficult. However, the ability to directly convert fibroblasts into cardiomyocyte-like cells both in vitro and in vivo offers great promise in overcoming this problem. In this review, we describe the insights and progress that have been gained from the investigation of direct cardiac reprogramming. We focus on the use of key transcription factors and cardiogenic genes as well as on the use of other biological molecules such as small molecules, cytokines, noncoding RNAs, and epigenetic modifiers to improve the efficiency of cardiac reprogramming. Finally, we discuss the development of safer reprogramming approaches for future clinical application.

Renal lineage cells as a source for renal regeneration

The mammalian kidney is a highly complex organ, composed of various cell types within a unique structural framework. Nonetheless, in recent years, giant leaps in our understanding of nephrogenesis and the origin of new cells in the adult kidney have resulted in novel routes to regenerate damaged nephrons. While several strategies can be envisioned to achieve this aim, one common theme is the reliance on renal lineage cells, as extrarenal cells, such as bone marrow-derived cells, have been shown to be devoid of renal differentiation capacity. Herein, we will present the main motivation for the pursuit for cell-based therapies, which is the ever growing problem of chronic kidney disease (CKD), and discuss different strategies toward replenishing the damaged renal parenchyma. These include transplantation of fetal kidney grafts or fetal kidney stem cells, directed differentiation of pluripotent stem cells into kidney epithelia, establishment of renal progenitors from the adult kidney, and genetic reprogramming of mature kidney cells into a progenitor state. Taken together with novel techniques recapitulating the three-dimensional developmental environment, these advances are expected to take the field into a new era, bringing us closer than ever to the day when kidney stem cell-based therapy becomes a viable therapeutic option.