Nitric oxide (NO) is a gaseous biomolecule endogenously synthesized with an essential role in embryonic development and several physiological functions, such as regulating mitochondrial respiration and modulation of the immune response. The dual role of NO in embryonic stem cells (ESCs) has been previously reported, preserving pluripotency and cell survival or inducing differentiation with a dose-dependent pattern. In this line, high doses of NO have been used in vitro cultures to induce focused differentiation toward different cell lineages being a key molecule in the regenerative medicine field. Moreover, optimal conditions to promote pluripotency in vitro are essential for their use in advanced therapies. In this sense, the molecular mechanisms underlying stemness regulation by NO have been studied intensively over the current years. Recently, we have reported the role of low NO as a hypoxia-like inducer in pluripotent stem cells (PSCs), which supports using this molecule to maintain pluripotency under normoxic conditions. In this review, we stress the role of NO levels on stem cells (SCs) fate as a new approach for potential cell therapy strategies. Furthermore, we highlight the recent uses of NO in regenerative medicine due to their properties regulating SCs biology.

The optimization of conditions to promote the stemness of pluripotent cells in vitro is instrumental for their use in advanced therapies. We show here that exposure of human iPSCs and human ESCs to low concentrations of the chemical NO donor DETA/NO leads to stabilization of hypoxia-inducible factors (HIF-1α and HIF-2α) under normoxia, with this effect being dependent on diminished Pro 402 hydroxylation and decreased degradation by the proteasome. Moreover, the master genes of pluripotency, NANOG and OCT-4, were upregulated. NO also induces a shift in the metabolic profile of PSCs, with an increased expression of hypoxia response genes in glycolysis. Furthermore, a reduction in the mitochondrial membrane potential with lower oxygen consumption and increased expression of mitochondrial fusion regulators, such as DRP1, was observed. The results reported here indicate that NO mimics hypoxia response in human PSCs and enhances their stemness properties when cultured under normoxic conditions.

Globally, a leg is amputated approximately every 30 seconds, with an estimated 85 percent of these amputations being attributed to complications arising from diabetic foot ulcers (DFU), as stated by the American Diabetes Association. Peripheral arterial disease (PAD) is a risk factor resulting in DFU and can, either independently or in conjunction with diabetes, lead to recurring, slow-healing ulcers and amputations. According to guidelines amputation is the recommended treatment for patients with no-option critical ischemia of the limb (CTLI). In this article we propose cell therapy as an alternative strategy for those patients. We also suggest the optimal time-frame for an effective therapy, such as implanting autologous mononuclear cells (MNCs), autologous and allogeneic mesenchymal stromal cells (MSC) as these treatments induce neuropathy relief, regeneration of the blood vessels and tissues, with accelerated ulcer healing, with no serious side effects, proving that advanced therapy medicinal product (ATMPs) application is safe and effective and, hence, can significantly prevent limb amputation.

The transcription factor, early growth response-1 (EGR-1), is involved in the regulation of cell differentiation, proliferation, and apoptosis in response to different stimuli. EGR-1 is described to be involved in pancreatic endoderm differentiation, but the regulatory mechanisms controlling its action are not fully elucidated. Our previous investigation reported that exposure of mouse embryonic stem cells (mESCs) to the chemical nitric oxide (NO) donor diethylenetriamine nitric oxide adduct (DETA-NO) induces the expression of early differentiation genes such as pancreatic and duodenal homeobox 1 (Pdx1). We have also evidenced that Pdx1 expression is associated with the release of polycomb repressive complex 2 (PRC2) and P300 from the Pdx1 promoter; these events were accompanied by epigenetic changes to histones and site-specific changes in the DNA methylation. Here, we investigate the role of EGR-1 on Pdx1 regulation in mESCs. This study reveals that EGR-1 plays a negative role in Pdx1 expression and shows that the binding capacity of EGR-1 to the Pdx1 promoter depends on the methylation level of its DNA binding site and its acetylation state. These results suggest that targeting EGR-1 at early differentiation stages might be relevant for directing pluripotent cells into Pdx1-dependent cell lineages.

Objectives: COVID-19, caused by the SARS-CoV-2 virus, has infected over 777 million individuals and led to approximately 7 million deaths worldwide. Despite significant efforts to develop effective therapies, treatment remains largely supportive, especially for severe complications like acute respiratory distress syndrome (ARDS). Numerous compounds from diverse pharmacological classes are currently undergoing preclinical and clinical evaluation, targeting both the virus and the host immune response. Methods: Despite the large number of articles published and after a preliminary attempt was published, we discarded the option of a systematic review. Instead, we have done a description of therapies with these results and a tentative mechanism of action. Results: Preliminary studies and early-phase clinical trials have demonstrated the potential of Mesenchymal Stem Cells (MSCs) in mitigating severe lung damage in COVID-19 patients. Previous research has shown MSCs to be effective in treating various pulmonary conditions, including acute lung injury, idiopathic pulmonary fibrosis, ARDS, asthma, chronic obstructive pulmonary disease, and lung cancer. Their ability to reduce inflammation and promote tissue repair supports their potential role in managing COVID-19-related complications. This review demonstrates the utility of MSCs in the acute phase of COVID-19 and postulates the etiopathogenic role of mitochondria in Long-COVID. Even more, their combination with other therapies is also analyzed. Conclusions: While the therapeutic application of MSCs in COVID-19 is still in early stages, emerging evidence suggests promising outcomes. As research advances, MSCs may become an integral part of treatment strategies for severe COVID-19, particularly in addressing immune-related lung injury and promoting recovery. However, a full pathogenic mechanism may explain or unify the complexity of signs and symptoms of Long COVID and Post-Acute Sequelae (PASC).

Background: COVID-19, caused by the SARS-CoV-2 virus, has infected over 777 million individuals and led to approximately 7 million deaths worldwide. Despite significant efforts to develop effective therapies, treatment remains largely supportive, especially for severe complications like acute respiratory distress syndrome (ARDS). Numerous com-pounds from diverse pharmacological classes are currently undergoing preclinical and clinical evaluation, targeting both the virus and the host immune response. Methods: Despite the large number of articles published and after a preliminary attempt published, we discarded the option of a systematic review (PRISMA Method). Instead we have done a description of therapies with these results and tentative mechanism of action. Results: Preliminary studies and early-phase clinical trials have demonstrated the potential of Mesenchymal Stem Cells (MSCs) in mitigating severe lung damage in COVID-19 pa-tients. Previous research has shown MSCs to be effective in treating various pulmonary conditions, including acute lung injury, idiopathic pulmonary fibrosis, ARDS, asthma, chronic obstructive pulmonary disease, and lung cancer. Their ability to reduce inflam-mation and promote tissue repair supports their potential role in managing COVID-19-related complications. This review demonstrates the utility of MSCs on the acute phase of COVID-19 and postulates the etiopathogenic role of mitochondria in the Long-COVID. Even more, their combination with other therapies is also analyzed. Con-clusions: While the therapeutic application of MSCs in COVID-19 is still in early stages, emerging evidence suggests promising outcomes. As research advances, MSCs may be-come an integral part of treatment strategies for severe COVID-19, particularly in ad-dressing immune-related lung injury and promoting recovery. However, a full patho-genic mechanism which may explain or unify the complexity of signs and symptoms of Long COVID and Post-Acute Sequealae (PASC).