The myocardium behaves like a sophisticated orchestra that expresses its true potential only if each member performs the correct task harmonically. Recapitulating its complexity within engineered 3D functional constructs with tailored biological and mechanical properties, is one of the current scientific priorities in the field of regenerative medicine and tissue engineering. In this study, driven by the necessity of fabricating advanced model of cardiac tissue, we present an innovative approach consisting of heterogeneous, multi-cellular constructs composed of Human Umbilical Vein Endothelial Cells (HUVECs) and induced pluripotent cell-derived cardiomyocytes (iPSC-CMs). Cells were encapsulated within hydrogel strands containing alginate and PEG-Fibrinogen (PF) and extruded through a custom microfluidic printing head (MPH) that allows to precisely tailor their 3D spatial deposition, guaranteeing a high printing fidelity and resolution. We obtained a 3D cardiac tissue compose of iPSC-derived CMs with a high orientation index imposed by the different defined geometries and blood vessel-like shapes generated by HUVECs which, as demonstrated by in vivo grafting, better support the integration of the engineered cardiac tissue with host’s vasculature.

Extracellular vesicles (EVs) have become a key tool in the biotechnological landscape due to their well-documented ability to mediate intercellular communication. This feature has been explored and is under constant investigation by researchers, who have demonstrated the important role of EVs in several research fields ranging from oncology to immunology and diagnostics to regenerative medicine. Unfortunately, there are still some limitations to overcome before clinical application, including the inability to confine the EVs to strategically defined sites of interest to avoid side effects. In this study, for the first time, EV application is supported by 3D bioprinting technology to develop a new strategy for applying the angiogenic cargo of human umbilical vein endothelial cell-derived EVs in regenerative medicine. EVs, derived from human endothelial cells and grown under different stressed conditions, were collected and used as bioadditives for the formulation of advanced bioinks. After in vivo subcutaneous implantation, we demonstrated that the bioprinted 3D structures, loaded with EVs, supported the formation of a new functional vasculature in situ, consisting of blood-perfused microvessels recapitulating the printed pattern. The results obtained in this study favour the development of new therapeutic approaches for critical clinical conditions, such as the need for prompt revascularization of ischaemic tissues, which represent the fundamental substrate for advanced regenerative medicine applications.

Cardiovascular diseases (CVDs) are a major burden on the healthcare system: indeed, over two million new cases are diagnosed every year worldwide. Unfortunately, important drawbacks for the treatment of these patients derive from our current inability to stop the structural alterations that lead to heart failure, the common endpoint of many CVDs. In this scenario, a better understanding of the role of epigenetics – hereditable changes of chromatin that do not alter the DNA sequence itself – is warranted. To date, hyperacetylation of histones has been reported in hypertension and myocardial infarction, but the use of inhibitors for treating CVDs remains limited. Here, we studied the effect of the histone deacetylase inhibitor Givinostat on a mouse model of acute myocardial infarction. We found that it contributes to decrease endothelial-to-mesenchymal transition and inflammation, reducing cardiac fibrosis and improving heart performance and protecting the blood vessels from apoptosis through the modulatory effect of cardiac fibroblasts on endothelial cells. Therefore, Givinostat may have potential for the treatment of CVDs.

Estrogen activity towards cancer-related pathways can impact therapeutic intervention. Recent omics data suggest possible crosstalk between estrogens/gender and MDM4, a key regulator of p53. Since MDM4 can either promote cell transformation or enhance DNA damage-sensitivity, we analysed in vivo impact of estrogens on both MDM4 activities. In Mdm4 transgenic mouse, Mdm4 accelerates the formation of fibrosarcoma and increases tumor sensitivity to cisplatin as well, thus confirming in vivo Mdm4 dual mode of action. Noteworthy, Mdm4 enhances chemo- and radio-sensitivity in male but not in female animals, whereas its tumor-promoting activity is not affected by mouse gender. Combination therapy of transgenic females with cisplatin and fulvestrant, a selective estrogen receptor degrader, was able to recover tumor cisplatin-sensitivity, demonstrating the relevance of estrogens in the observed sexual dimorphism. Molecularly, estrogen receptor-α alters intracellular localization of MDM4 by increasing its nuclear fraction correlated to decreased cell death, in a p53-independent manner. Importantly, MDM4 nuclear localization and intra-tumor estrogen availability correlate with decreased platinum-sensitivity and apoptosis and predicts poor disease-free survival in high-grade serous ovarian carcinoma. These data demonstrate estrogen ability to modulate chemo-sensitivity of MDM4-expressing tumors and to impinge on intracellular trafficking. They support potential usefulness of combination therapy involving anti-estrogenic drugs.

Epithelial ovarian cancer (EOC) is a highly heterogeneous disease with a high death rate mainly due to the metastatic spread. The expression of MDM4, a well-known p53-inhibitor, is positively associated with chemotherapy response and overall survival (OS) in EOC. However, the basis of this association remains elusive. We show that in vivo MDM4 reduces intraperitoneal dissemination of EOC cells, independently of p53 and an immune-competent background. By 2D and 3D assays, MDM4 impairs the early steps of the metastatic process. A 3D-bioprinting system, ad hoc developed by co-culturing EOC spheroids and endothelial cells, showed reduced dissemination and intravasation into vessel-like structures of MDM4-expressing cells. Consistent with these data, high MDM4 levels protect mice from ovarian cancer-related death and, importantly, correlate with increased 15 y OS probability in large data set analysis of 1656 patients. Proteomic analysis of EOC 3D-spheroids revealed decreased protein synthesis and mTOR signaling, upon MDM4 expression. Accordingly, MDM4 does not further inhibit cell migration when its activity towards mTOR is blocked by genetic or pharmacological approaches. Importantly, high levels of MDM4 reduced the efficacy of mTOR inhibitors in constraining cell migration. Overall, these data demonstrate that MDM4 impairs EOC metastatic process by inhibiting mTOR activity and suggest the usefulness of MDM4 assessment for the tailored application of mTOR-targeted therapy.

Long non-coding RNAs (lncRNAs) are a large, heterogeneous class of transcripts and key regulators of gene expression at both the transcriptional and post-transcriptional levels in different cellular contexts and biological processes. Understanding the potential mechanisms of action of lncRNAs and their role in disease onset and development may open up new possibilities for therapeutic approaches in the future. LncRNAs also play an important role in renal pathogenesis. However, little is known about lncRNAs that are expressed in the healthy kidney and that are involved in renal cell homeostasis and development, and even less is known about lncRNAs involved in human adult renal stem/progenitor cells (ARPC) homeostasis. Here we give a thorough overview of the biogenesis, degradation, and functions of lncRNAs and highlight our current understanding of their functional roles in kidney diseases. We also discuss how lncRNAs regulate stem cell biology, focusing finally on their role in human adult renal stem/progenitor cells, in which the lncRNA HOTAIR prevents them from becoming senescent and supports these cells to secrete high quantities of α-Klotho, an anti-aging protein capable of influencing the surrounding tissues and therefore modulating the renal aging.