Knockout mice are an important tool for human monogenic heart disease studies

Elevated IGFBP7 expression in follicular granulosa cells promotes PCOS pathogenesis

Polycystic ovary syndrome (PCOS) can result in female infertility, menstrual irregularities, metabolic disturbances, hormonal imbalances, and significantly impact the reproductive health of women of childbearing age. Hyperandrogenism and insulin resistance are typical primary endocrine features of PCOS, which are also regarded as its core pathogenesis. In this study, IGFBP7 expression in granulosa cells (GCs) from women with and without PCOS was analyzed using bulk RNA-seq. A PCOS-like mouse model was constructed using dehydroepiandrosterone in IGFBP7 knockout and wild-type mice to explore the role of IGFBP7 in PCOS. Primary GCs from mice were cultured and transfected with IGFBP7 overexpression plasmid and siRNA fragments. Proliferation, apoptosis, and steroid hormone levels were measured to investigate the effects of IGFBP7 on granulosa cells. IGFBP7 expression was found to be elevated in patients with PCOS. Following IGFBP7 knockdown in mouse GC, there was a significant increase in GC proliferation, a decrease in GC apoptosis, and a notable decrease in testosterone secretion by GC. Conversely, overexpression of IGFBP7 in mouse granulosa cells significantly inhibited GC proliferation, significantly increased GC apoptosis, and led to a marked increase in testosterone secretion by GCs. With mouse model, a reduction in PCOS symptoms in mice after IGFBP7 deletion was observed. Elevated IGFBP7 expression in PCOS granulosa cells may induce apoptosis, hinder insulin signaling, and enhance androgen synthesis. These insights offer novel avenues for understanding and treating PCOS.

In Vitro Models of Cardiovascular Disease: Embryoid Bodies, Organoids and Everything in Between

Cardiovascular disease comprises a group of disorders affecting or originating within tissues and organs of the cardiovascular system; most, if not all, will eventually result in cardiomyocyte dysfunction or death, negatively impacting cardiac function. Effective models of cardiac disease are thus important for understanding crucial aspects of disease progression, while recent advancements in stem cell biology have allowed for the use of stem cell populations to derive such models. These include three-dimensional (3D) models such as stem cell-based models of embryos (SCME) as well as organoids, many of which are frequently derived from embryoid bodies (EB). Not only can they recapitulate 3D form and function, but the developmental programs governing the self-organization of cell populations into more complex tissues as well. Many different organoids and SCME constructs have been generated in recent years to recreate cardiac tissue and the complex developmental programs that give rise to its cellular composition and unique tissue morphology. It is thus the purpose of this narrative literature review to describe and summarize many of the recently derived cardiac organoid models as well as their use for the recapitulation of genetic and acquired disease. Owing to the cellular composition of the models examined, this review will focus on disease and tissue injury associated with embryonic/fetal tissues.

Mouse Cardiovascular Imaging

The mouse is the mammalian model of choice for investigating cardiovascular biology, given our ability to manipulate it by genetic, pharmacologic, mechanical, and environmental means. Imaging is an important approach to phenotyping both function and structure of cardiac and vascular components. This review details commonly used imaging approaches, with a focus on echocardiography and magnetic resonance imaging, with brief overviews of other imaging modalities. In this update, we also emphasize the importance of rigor and reproducibility in imaging approaches, experimental design, and documentation. Finally, we briefly outline emerging imaging approaches but caution that reliability and validity data may be lacking. © 2024 Wiley Periodicals LLC.

Computational identification of disease models through cross-species phenotype comparison

The use of standardised phenotyping screens to identify abnormal phenotypes in mouse knockouts, together with the use of ontologies to describe such phenotypic features, allows the implementation of an automated and unbiased pipeline to identify new models of disease by performing phenotype comparisons across species. Using data from the International Mouse Phenotyping Consortium (IMPC), approximately half of mouse mutants are able to mimic, at least partially, the human ortholog disease phenotypes as computed by the PhenoDigm algorithm. We found the number of phenotypic abnormalities in the mouse and the corresponding Mendelian disorder, the pleiotropy and severity of the disease, and the viability and zygosity status of the mouse knockout to be associated with the ability of mouse models to recapitulate the human disorder. An analysis of the IMPC impact on disease gene discovery through a publication-tracking system revealed that the resource has been implicated in at least 109 validated rare disease-gene associations over the last decade.

A review of standardized high-throughput cardiovascular phenotyping with a link to metabolism in mice

Cardiovascular diseases cause a high mortality rate worldwide and represent a major burden for health care systems. Experimental rodent models play a central role in cardiovascular disease research by effectively simulating human cardiovascular diseases. Using mice, the International Mouse Phenotyping Consortium (IMPC) aims to target each protein-coding gene and phenotype multiple organ systems in single-gene knockout models by a global network of mouse clinics. In this review, we summarize the current advances of the IMPC in cardiac research and describe in detail the diagnostic requirements of high-throughput electrocardiography and transthoracic echocardiography capable of detecting cardiac arrhythmias and cardiomyopathies in mice. Beyond that, we are linking metabolism to the heart and describing phenotypes that emerge in a set of known genes, when knocked out in mice, such as the leptin receptor (Lepr), leptin (Lep), and Bardet-Biedl syndrome 5 (Bbs5). Furthermore, we are presenting not yet associated loss-of-function genes affecting both, metabolism and the cardiovascular system, such as the RING finger protein 10 (Rfn10), F-box protein 38 (Fbxo38), and Dipeptidyl peptidase 8 (Dpp8). These extensive high-throughput data from IMPC mice provide a promising opportunity to explore genetics causing metabolic heart disease with an important translational approach.