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MicroRNAs (miRNAs) are small non-coding RNAs which contribute to the regulation of many physiological and pathological processes. Conventionally, miRNAs perform their activity in the cytoplasm where they regulate gene expression by interacting in a sequence-specific manner with mature messenger RNAs. Recent studies point to the presence of mature miRNAs in the nucleus. This review summarizes current findings regarding the molecular activities of nuclear miRNAs. These molecules can regulate gene expression at the transcriptional level by directly binding DNA on the promoter or the enhancer of regulated genes. miRNAs recruit different protein complexes to these regions, resulting in activation or repression of transcription, through a number of molecular mechanisms. Hematopoiesis is presented as a paradigmatic biological process whereby nuclear miRNAs possess a relevant regulatory role. Nuclear miRNAs can influence gene expression by affecting nuclear mRNA processing and by regulating pri-miRNA maturation, thus impacting the biogenesis of miRNAs themselves. Overall, nuclear miRNAs are biologically active molecules that can be critical for the fine tuning of gene expression and deserve further studies in a number of physiological and pathological conditions. [ABSTRACT FROM AUTHOR]

Objectives: Extracellular vesicles (EVs) are key biological mediators of several physiological functions within the cell microenvironment. Platelets are the most abundant source of EVs in the blood. Similarly, platelet lysate (PL), the best platelet derivative and angiogenic performer for regenerative purposes, is enriched of EVs, but their role is still too poorly discovered to be suitably exploited. Here, we explored the contribution of the EVs in PL, by investigating the angiogenic features extrapolated from that possessed by PL. Methods: We tested angiogenic ability and molecular cargo in 3D bioprinted models and by RNA sequencing analysis of PL‐derived EVs. Results: A subset of small vesicles is highly represented in PL. The EVs do not retain aggregation ability, preserving a low redox state in human umbilical vein endothelial cells (HUVECs) and increasing the angiogenic tubularly‐like structures in 3D endothelial bioprinted constructs. EVs resembled the miRNome profile of PL, mainly enriched with small RNAs and a high amount of miR‐126, the most abundant angiogenic miRNA in platelets. The transfer of miR‐126 by EVs in HUVEC after the in vitro inhibition of the endogenous form, restored angiogenesis, without involving VEGF as a downstream target in this system. Conclusion: PL is a biological source of available EVs with angiogenic effects involving a miRNAs‐based cargo. These properties can be exploited for targeted molecular/biological manipulation of PL, by potentially developing a product exclusively manufactured of EVs. [ABSTRACT FROM AUTHOR]

Serum albumin (SA) is the most abundant protein in plasma and represents the main carrier of endogenous and exogenous compounds. Several evidence supports the notion that SA binds single and double‐stranded deoxynucleotides and ribonucleotides at two sites, with values of the dissociation equilibrium constant (i.e., Kd) ranging from micromolar to nanomolar values. This can be relevant from a physiological and pathological point of view, as in human plasma circulates cell‐free nucleic acids (cfNAs), released by different tissues via apoptosis, necrosis, and secretions, circulates as single and double‐stranded NAs. Albeit SA shows low hydrolytic reactivity toward DNA and RNA, the high plasma concentration of this protein and the occurrence of several SA receptors may be pivotal for sequestering and hydrolyzing cfNAs. Therefore, pathological conditions like cancer, characterized by altered levels of human SA or by altered SA post‐translational modifications, may influence cfNAs distribution and metabolism. Besides, the stability, solubility, biocompatibility, and low immunogenicity make SA a golden share for biotechnological applications related to the delivery of therapeutic NAs (TNAs). Indeed, pre‐clinical studies report the therapeutic potential of SA:TNAs complexes in precision cancer therapy. Here, the molecular and biotechnological implications of SA:NAs interaction are discussed, highlighting new perspectives on SA plasmatic functions. [ABSTRACT FROM AUTHOR]

Epigenetic treatment has been approved by regulatory agencies for haematological malignancies. The success observed in cutaneous lymphomas represents a proof of principle that similar results may be obtained in solid tumours. Several agents that interfere with DNA methylation-demethylation and histones acetylation/deacetylation have been studied, and some (such as azacytidine, decitabine, valproic acid and vorinostat) are already in clinical use. The aim of this review is to provide a brief overview of the molecular events underlying the antitumour effects of epigenetic treatments and to summarise data available on clinical trials that tested the use of epigenetic agents against solid tumours. We not only list results but also try to indicate how the proper evaluation of this treatment might result in a better selection of effective agents and in a more rapid development. We divided compounds in demethylating agents and HDAC inhibitors. For each class, we report the antitumour activity and the toxic side effects. When available, we describe plasma pharmacokinetics and pharmacodynamic evaluation in tumours and in surrogate tissues (generally white blood cells). Epigenetic treatment is a reality in haematological malignancies and deserves adequate attention in solid tumours. A careful consideration of available clinical data however is required for faster drug development and possibly to re-evaluate some molecules that were perhaps discarded too early. [ABSTRACT FROM AUTHOR]

Globins have been found in glial cells and neurons of invertebrates and vertebrates. The first nerve globin has been recognized in the nerve cord of the polychaete annelid Aphrodite aculeata in 1872. In some invertebrates, the nerve globin reaches a millimolar concentration which is likely sufficient to sustain the aerobic metabolism and thus the excitability of the nervous system. In 2000, the first vertebrate nerve globin, named neuroglobin (Ngb), has been identified in neuronal tissues of mice and humans. In contrast to invertebrate nerve globins, the concentration of Ngb, the prototype of vertebrate nerve globins, is low (μM), reaching a maximum of 100 μM in retina cells. Therefore, Ngb appears unlikely to act primarily as an O buffer and to facilitate O diffusion to the mitochondria. Indeed, Ngb has been hypothesized to catalyze the formation/decomposition of reactive nitrogen and/or oxygen species and to be part of intracellular signaling pathways enhancing cell survival. Here, we report that neuronal Ngb levels are strongly induced by the steroid hormone 17β-estradiol. Furthermore, Ngb participates to mechanisms involved in 17β-estradiol-induced protective effects against HO-induced neurotoxicity. © 2011 IUBMB IUBMB Life, 63(3): 140-145, 2011 [ABSTRACT FROM AUTHOR]

Globins protect from the oxidative and nitrosative cell damage. Here, kinetics of peroxynitrite scavenging by ferryl sperm whale myoglobin (Mb—Fe(IV)ꘌO) and human hemoglobin (Hb—Fe(IV)ꘌO), between pH 5.8 and 8.3 at 20.0 °C, are reported. In the absence of CO2, values of the second-order rate constant for peroxynitrite scavenging by Mb—Fe(IV)ꘌO and Hb—Fe(IV)ꘌO (i.e., for Mb—Fe(III) and Hb—Fe(III) formation; kon) are 4.6 × 104 M−1 s−1 and 3.3 × 104 M−1 s−1, respectively, at pH 7.1. Values of kon increase on decreasing pH with pKa values of 6.9 and 6.7, this suggests that the ONOOH species reacts preferentially with Mb—Fe(IV)ꘌO and Hb—Fe(IV)ꘌO. In the presence of CO2 (=1.2 × 10−3 M), values of kon for peroxynitrite scavenging by Mb—Fe(IV)ꘌO and Hb—Fe(IV)ꘌO are essentially pH-independent, the average kon values are 7.1 × 104 M−1 s−1 and 1.2 × 105 M−1 s−1, respectively. As a whole, Mb—Fe(IV)ꘌO and Hb—Fe(IV)ꘌO, obtained by treatment with H2O2, undertake within the same cycle H2O2 and peroxynitrite detoxification. [Copyright &y& Elsevier]

Globins are generally considered as carriers of diatomic gaseous ligands (e.g., O2 and NO) in metazoa. Recently, the (pseudo-)enzymatic activity of globins towards reactive nitrogen and oxygen species has been elucidated. In particular, some globins (e.g., hemoglobin and myoglobin) catalyze the enzymatic scavenging of NO and peroxynitrite in the presence of H2O2. Indeed, H2O2 oxidizes some globins leading to the formation of water and of the heme-protein ferryl derivative, which, in turn, oxidizes NO and peroxynitrite leading to the formation of the globin ferric species, NO2-, and NO3-. Here, we hypothesize that NO, peroxynitrite, and H2O2 are co-substrates for the peroxidase activity of some globins, this catalytic activity was reported in 1900 for the first time, even though the substrates have never been identified firmly up to now. © 2008 IUBMB IUBMB Life, 61(1): 62–73, 2009 [ABSTRACT FROM AUTHOR]

Acute promyelocytic leukemia (APL) is a hematological disease characterized by a balanced reciprocal translocation that leads to the synthesis of the oncogenic fusion protein PML-RARα. APL is mainly managed by a differentiation therapy based on the administration of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). However, therapy resistance, differentiation syndrome, and relapses require the development of new low-toxicity therapies based on the induction of blasts differentiation. In keeping with this, we reasoned that a better understanding of the molecular mechanisms pivotal for ATRA-driven differentiation could definitely bolster the identification of new therapeutic strategies in APL patients. We thus performed an in-depth high-throughput transcriptional profile analysis and metabolic characterization of a well-established APL experimental model based on NB4 cells that represent an unevaluable tool to dissect the complex mechanism associated with ATRA-induced granulocytic differentiation. Pathway-reconstruction analysis using genome-wide transcriptional data has allowed us to identify the activation/inhibition of several cancer signaling pathways (e.g., inflammation, immune cell response, DNA repair, and cell proliferation) and master regulators (e.g., transcription factors, epigenetic regulators, and ligand-dependent nuclear receptors). Furthermore, we provide evidence of the regulation of a considerable set of metabolic genes involved in cancer metabolic reprogramming. Consistently, we found that ATRA treatment of NB4 cells drives the activation of aerobic glycolysis pathway and the reduction of OXPHOS-dependent ATP production. Overall, this study represents an important resource in understanding the molecular "portfolio" pivotal for APL differentiation, which can be explored for developing new therapeutic strategies. [ABSTRACT FROM AUTHOR]

Cancer alters both local and distant tissue by influencing the microenvironment. In this regard, the interplay with the stromal fraction is considered critical as this latter can either foster or hamper the progression of the disease. Accordingly, the modality by which tumors may alter distant niches of stromal cells is still unclear, especially at early stages. In this short report, we attempt to better understand the biology of this cross-talk. In our "autologous stromal experimental setting," we found that remote adipose tissue-derived mesenchymal stem cells (mediastinal AMSC) obtained from patients with lung adenocarcinoma sustain proliferation and clonogenic ability of A549 and human primary lung adenocarcinoma cells similarly to the autologous stromal lung counterpart (LMSC). This effect is not observed in lung benign diseases such as the hamartochondroma. This finding was validated by conditioning benign AMSC with supernatants from LAC for up to 21 days. The new reconditioned media of the stromal fraction so obtained, was able to increase cell proliferation of A549 cells at 14 and 21 days similar to that derived from AMSC of patients with lung adenocarcinoma. The secretome generated by remote AMSC revealed overlapping to the corresponding malignant microenvironment of the autologous local LMSC. Among the plethora of 80 soluble factors analyzed by arrays, a small pool of 5 upregulated molecules including IL1- β , IL-3, MCP-1, TNF- α, and EGF, was commonly shared by both malignant-like autologous A- and L-MSC derived microenvironments vs those benign. The bioinformatics analysis revealed that these proteins were strictly and functionally interconnected to lung fibrosis and proinflammation and that miR-126, 101, 486, and let-7-g were their main targets. Accordingly, we found that in lung cancer tissues and blood samples from the same set of patients here employed, miR-126 and miR-486 displayed the highest expression levels in tissue and blood, respectively. When the miR-126-3p was silenced in A549 treated with AMSC-derived conditioned media from patients with lung adenocarcinoma, cell proliferation decreased compared to control media., Competing Interests: The authors declare that they have no conflict of interest., (Copyright © 2023 Elena De Falco et al.)

Although discovered in 2000, neuroglobin (Ngb) functions are still uncertain. A contribution to the role played by Ngb in neurons could certainly derive from the identification of Ngb endogenous modulators. Here, we evaluate the possibility that Ngb could be regulated by 17β-estradiol (E₂) signaling in both SK-N-BE human neuroblastoma cell line and mouse hippocampal neurons. 1 nM E₂ rapidly induced a 300% increase in Ngb levels in both models. The E₂ effect was specific, being not induced by testosterone or dihydrotestosterone. The E₂-induced Ngb increase requires estrogen receptor (ER) β, but not ERα, as evaluated by the mimetic effect of ERβ-specific agonist DPN and by the blockage of E₂ effect in ERβ-silenced SK-N-BE cells. Furthermore, both rapid (15 min) ERβ-dependent activation of p38/MAPK and transcriptional ERβ activity were required for the estrogenic regulation of Ngb. Finally, E₂ exerted a protective effect against H₂O₂-induced neuroblastoma cell death which was completely prevented in Ngb-silenced cells. Overall, these data suggest that Ngb is part of the E₂ signaling mechanism that is activated to exert protective effects against H₂O₂-induced neurotoxicity., (Copyright © 2011 S. Karger AG, Basel.)

Among several types of DNA lesions, the DNA double strand breaks (DSBs) are one of the most deleterious and harmful. Mammalian cells mount a coordinated response to DSBs with the aim of appropriately repair the DNA damage. Indeed, failure of the DNA damage response (DDR) can lead to the development of cancer-prone genetic diseases. The identification and development of drugs targeting proteins involved in the DDR is even more investigated, as it gives the possibility to specifically target cancer cells. Indeed, the administration of DNA repair inhibitors could be combined with chemo- and radiotherapy, thus improving the eradication of tumor cells. Here, we provide an overview about DSBs damage response, focusing on the role of the DSBs repair mechanisms, of chromatin modifications, and of the cancer susceptibility gene BRCA1 which plays a multifunctional role in controlling genome integrity. Moreover, the most investigated DSBs enzyme inhibitors tested as potential therapeutic agents for anti-cancer therapy are reported.

Nuclear receptors (NRs) are ligand-activated transcription factors sharing a common evolutionary history and having similar sequence features at the protein level. Selective ligand(s) for some NRs is not known, therefore these NRs have been named "orphan receptors". Whenever ligands have been recognized for any of the orphan receptor, it has been categorized and grouped as "adopted" orphan receptor. This group includes the constitutive androstane receptor (CAR) and the pregnane X receptor (PXR). They function as sensors of toxic byproducts derived from endogenous metabolites and of exogenous chemicals, in order to enhance their elimination. This unique function of CAR and PXR sets them apart from the steroid hormone receptors. The broad response profile has established that CAR and PXR are xenobiotic sensors that coordinately regulate xenobiotic clearance in the liver and intestine via induction of genes involved in drug and xenobiotic metabolism. In the past few years, research has revealed new and mostly unsuspected roles for CAR and PXR in modulating hormone, lipid, and energy homeostasis as well as cancer and liver steatosis. The purpose of this review is to highlight the structural and molecular bases of CAR and PXR impact on human health, providing information on mechanisms through which diet, chemical exposure, and environment ultimately impact health and disease.

Physiological sex differences may influence metabolic status and then alter the onset of some diseases. According to recent studies, it is now well established that females are more protected from hypercholesterolemia-related diseases, such as cardiovascular diseases until menopause. Female protection from hypercholesterolemia is mediated by the hypolipidemic properties of estrogens, even if mechanisms underlying this protection remain still debated. Even though the regulatory mechanisms of cholesterol homeostasis maintenance are well known, few data are available on the supposed differences between male and female in these processes. So, the aim of this work was to define, through an in vivo study, the putative sex-dependent regulation of the processes underlying cholesterol homeostasis maintenance. We examined 3-hydroxy 3-methylglutaryl coenzyme A reductase and its regulatory protein network as well as the amount of low-density lipoprotein receptor and cholesterol. The study was conducted in the liver and plasma of male and female rats, on adults and during postnatal development, and on 17-beta-estradiol-treated male rats. Our data support that physiological differences in proteins involved in cholesterol balance are present between the sexes and, in particular, 3-hydroxy 3-methylglutaryl coenzyme A reductase shows lower activity and expression in female and 17-beta-estradiol-treated male rats than in adult untreated male. Our data suggest that sex differences in enzyme expression depend on variation in regulatory proteins and seem to be related to estrogen presence. This work adds new evidence in the complicated picture of sex-dependent cellular physiology and establishes a new role for reductase regulatory proteins as a link between estrogen protective effects and cholesterol homeostasis.

The rate of HIV-positive patients that fails to reach or to maintain a durable virological suppression under anti-retroviral (ARV) therapy might be as high as 50%, therefore new tools to improve ARV drug efficacy are urgently needed. Among others, therapeutic drug monitoring (TDM) is a strategy by which the dosing regimen for a patient is guided by measurement of plasma drug levels, enabling physicians to optimize ARV drug efficacy and to avoid drug-related toxicity. The most used analytical methods to determine plasma levels of ARV drugs are HPLC-UV and HPLC-MS(/MS), recently MALDI-based methods and enzyme immunoassay (EIA) technologies have been also employed. The wide inter-patient variability in ARV drug pharmacokinetic supports the application of TDM to the clinical management of HIV-infected patients. Drug-drug and drug-food interactions, drug binding to plasma proteins, drug sequestering by erythrocytes, hepatic impairment, sex, age, pregnancy, and host genetic factors are sources of inter-patient variability affecting ARV drug pharmacokinetics. Combining the information of TDM and resistance tests in genotypic inhibitory quotient (GIQ) is likely to be of great clinical utility. Indeed, only two clinical trials on GIQ, both conducted using ARV drugs not more commonly in use, have shown clinical benefits. The design of new trials with long follow-up and sample size representative of the current HIV prevalence is urgently needed to give indications for GIQ as an early predictor of virological response. Here, the basic principles and the available methods for TDM in the management of HIV-infected patients are reviewed.