Decrease in α-Globin and Increase in the Autophagy-Activating Kinase ULK1 mRNA in Erythroid Precursors from ß-Thalassemia Patients Treated with Sirolimus.

The ß-thalassemias are hereditary monogenic diseases characterized by a low or absent production of adult hemoglobin and excess in the content of α-globin. This excess is cytotoxic for the erythroid cells and responsible for the ß-thalassemia-associated ineffective erythropoiesis. Therefore, the decrease in excess α-globin is a relevant clinical effect for these patients and can be realized through the induction of fetal hemoglobin, autophagy, or both. The in vivo effects of sirolimus (rapamycin) and analogs on the induction of fetal hemoglobin (HbF) are of key importance for therapeutic protocols in a variety of hemoglobinopathies, including ß-thalassemias. In this research communication, we report data showing that a decrease in autophagy-associated p62 protein, increased expression of ULK-1, and reduction in excess α-globin are occurring in erythroid precursors (ErPCs) stimulated in vitro with low dosages of sirolimus. In addition, increased ULK-1 mRNA content and a decrease in α-globin content were found in ErPCs isolated from ß-thalassemia patients recruited for the NCT03877809 clinical trial and treated with 0.5-2 mg/day sirolimus. Our data support the concept that autophagy, ULK1 expression, and α-globin chain reduction should be considered important endpoints in sirolimus-based clinical trials for ß-thalassemias.

The Long Scientific Journey of Sirolimus (Rapamycin): From the Soil of Easter Island (Rapa Nui) to Applied Research and Clinical Trials on ß-Thalassemia and Other Hemoglobinopathies.

In this review article, we present the fascinating story of rapamycin (sirolimus), a drug able to induce γ-globin gene expression and increased production of fetal hemoglobin (HbF) in erythroid cells, including primary erythroid precursor cells (ErPCs) isolated from ß-thalassemia patients. For this reason, rapamycin is considered of great interest for the treatment of ß-thalassemia. In fact, high levels of HbF are known to be highly beneficial for ß-thalassemia patients. The story of rapamycin discovery began in 1964, with METEI, the Medical Expedition to Easter Island (Rapa Nui). During this expedition, samples of the soil from different parts of the island were collected and, from this material, an antibiotic-producing microorganism (Streptomyces hygroscopicus) was identified. Rapamycin was extracted from the mycelium with organic solvents, isolated, and demonstrated to be very active as an anti-bacterial and anti-fungal agent. Later, rapamycin was demonstrated to inhibit the in vitro cell growth of tumor cell lines. More importantly, rapamycin was found to be an immunosuppressive agent applicable to prevent kidney rejection after transplantation. More recently, rapamycin was found to be a potent inducer of HbF both in vitro using ErPCs isolated from ß-thalassemia patients, in vivo using experimental mice, and in patients treated with this compound. These studies were the basis for proposing clinical trials on ß-thalassemia patients.

ß-sitosterol ameliorates inflammation and Pseudomonas aeruginosa lung infection in a mouse model.

We previously demonstrated that ß-sitosterol (BSS) inhibits the expression of the chemokine IL-8 in CF bronchial epithelial cells exposed to P. aeruginosa. In the mouse model of lung chronic infection, herein shown, BSS significantly reduced leukocyte recruitment in the bronchoalveolar lavage fluid and decreased bacteria recovered in the airways. Treatment with BSS decreased the expression of key cytokines involved in immune response, mainly neutrophil chemotaxis, in the lung homogenate. This anti-inflammatory activity is accompanied by a beneficial protecting activity against infection and improvement of health status. Our data suggest that BSS has the potential to become a new drug to target the excessive neutrophil recruitment in lungs chronically infected by P. aeruginosa and encourage future investigations on mechanism of protection driven by BSS.

A Rational Approach to Drug Repositioning in ß-thalassemia: Induction of Fetal Hemoglobin by Established Drugs.

Drug repositioning and the relevance of orphan drug designation for ß-thalassemia is reviewed. Drug repositioning and similar terms ('drug repurposing', 'drug reprofiling', 'drug redirecting', 'drug rescue', 'drug re-tasking' and/or 'drug rediscovery') have gained great attention, especially in the field or rare diseases (RDs), and represent relevant novel drug development strategies to be considered together with the "off-label" use of pharmaceutical products under clinical trial regimen. The most significant advantage of drug repositioning over traditional drug development is that the repositioned drug has already passed a significant number of short- and long-term toxicity tests, as well as it has already undergone pharmacokinetic and pharmacodynamic (PK/PD) studies. The established safety of repositioned drugs is known to significantly reduce the probability of project failure. Furthermore, development of repurposed drugs can shorten much of the time needed to bring a drug to market. Finally, patent filing of repurposed drugs is expected to catch the attention of pharmaceutical industries interested in the development of therapeutic protocols for RDs. Repurposed molecules that could be proposed as potential drugs for ß-thalassemia, will be reported, with some of the most solid examples, including sirolimus (rapamycin) that recently has been tested in a pilot clinical trial.

Expression of γ-globin genes in ß-thalassemia patients treated with sirolimus: results from a pilot clinical trial (Sirthalaclin).

Introduction: ß-thalassemia is caused by autosomal mutations in the ß-globin gene, which induce the absence or low-level synthesis of ß-globin in erythroid cells. It is widely accepted that a high production of fetal hemoglobin (HbF) is beneficial for patients with ß-thalassemia. Sirolimus, also known as rapamycin, is a lipophilic macrolide isolated from a strain of Streptomyces hygroscopicus that serves as a strong HbF inducer in vitro and in vivo. In this study, we report biochemical, molecular, and clinical results of a sirolimus-based NCT03877809 clinical trial (a personalized medicine approach for ß-thalassemia transfusion-dependent patients: testing sirolimus in a first pilot clinical trial, Sirthalaclin). Methods: Accumulation of γ-globin mRNA was analyzed using reverse-transcription quantitative polymerase chain reaction (PCR), while the hemoglobin pattern was analyzed using high-performance liquid chromatography (HPLC). The immunophenotype was analyzed using a fluorescence-activated cell sorter (FACS), with antibodies against CD3, CD4, CD8, CD14, CD19, CD25 (for analysis of peripheral blood mononuclear cells), or CD71 and CD235a (for analysis of in vitro cultured erythroid precursors). Results: The results were obtained in eight patients with the ß+/ß+ and ß+/ß0 genotypes, who were treated with a starting dosage of 1 mg/day sirolimus for 24-48 weeks. The first finding of this study was that the expression of γ-globin mRNA increased in the blood and erythroid precursor cells isolated from ß-thalassemia patients treated with low-dose sirolimus. This trial also led to the important finding that sirolimus influences erythropoiesis and reduces biochemical markers associated with ineffective erythropoiesis (excess free α-globin chains, bilirubin, soluble transferrin receptor, and ferritin). A decrease in the transfusion demand index was observed in most (7/8) of the patients. The drug was well tolerated, with minor effects on the immunophenotype, and an only side effect of frequently occurring stomatitis. Conclusion: The data obtained indicate that low doses of sirolimus modify hematopoiesis and induce increased expression of γ-globin genes in a subset of patients with ß-thalassemia. Further clinical trials are warranted, possibly including testing of the drug in patients with less severe forms of the disease and exploring combination therapies.

Effects of palmitoylethanolamide and silymarin combination treatment in an animal model of kidney ischemia and reperfusion.

The aim of this study was to investigate the efficacy of PEA+silymarin as a combination treatment in a mouse model of renal I/R and to verify whether PEA+silymarin could exert more potent effects compared to the single substances even if administered at lower doses. Mice were subjected to bilateral renal artery occlusion (30min) and reperfusion (6h) and received intraperitoneally silymarin (100, 30 and 10mg/kg) or PEA (1mg/kg) or PEA (1mg/kg)+silymarin (10mg/kg) 15min before release of clamps. Specific indicators of renal dysfunction, tubular injury, myeloperoxidase activity and malondialdehyde levels were measured. The nuclear factor κB pathway and apoptotic mechanisms were also investigated. The treatment with silymarin reduced kidney dysfunction, histological damage, neutrophil infiltration and oxidative stress in a dose dependent manner. Furthermore, PEA+silymarin showed a significant potentiated effect. Therefore, NF-κB and apoptosis pathways were also significantly inhibited. Our results clearly demonstrate that PEA+silymarin treatment attenuated the degree of renal inflammation.

Effects of electromagnetic fields of low frequency and low intensity on rat metabolism.

A series of experiments on rats have been performed, to study the effects of long time (50 days) exposure to electromagnetic fields of extremely low frequency (ELF, i.e. less than 100 Hz) and amplitude (non thermal), testing whether the metabolic processes would be affected. The background lies on recent observations on the behaviour of isolated enzymes in vitro exposed to EFL fields. In these experiments, the cyclotron (or Larmor) frequency of the metallic ion has been used to "stimulate" the metalloproteins redox-active site, thus obtaining a clear variation of the enzyme functionality. In this paper we have extended for the first time the check to more complex animal metabolism. The novelty of this approach implies that a large amount of data had to be analyzed since it was not possible, in principle, to select only a few parameters among all the potential effects. Several biochemical parameters have been evaluated by comparing their values during the periods of exposure (field ON) and non exposure (field OFF). The evidence that long term exposure to electromagnetic fields with a well defined frequency may have relevant effects on parameters such as body weight, blood glucose and fatty acid metabolism has been obtained.

Toward the definition of the mechanism of action of silymarin: activities related to cellular protection from toxic damage induced by chemotherapy.

Silymarin, the active extract from milk thistle, has been extensively used in patients with liver disease of different etiology. Although silymarin is a complex of 7 flavonolignans and polyphenols, silibinin is usually regarded as the most active component. In vitro and in vivo studies indicate that silymarin and silibinin protect the liver from oxidative stress and sustained inflammatory processes, mainly driven by Reactive Oxygen Species (ROS) and secondary cytokines. Oxidative stress and inflammation are also involved in cellular damage of many other tissues and their role in the development and toxic reactions in patients receiving cancer therapies is established. The protective effects of silymarin and silibinin, demonstrated in various tissues, suggest a clinical application in cancer patients as an adjunct to established therapies, to prevent or reduce their toxicity. Here we discuss the possible mechanism of the protective action of silymarin and silibinin, focusing on cancer therapies as agents causing cellular damage.

Aescin protection of human vascular endothelial cells exposed to cobalt chloride mimicked hypoxia and inflammatory stimuli.

Human vascular endothelial cells (HUVECs) were exposed to CoCl2 as an in vitro model of hypoxia. Expression of VCAM-1 (vascular cell adhesion molecule), reduction of PECAM-1 (platelet endothelial cell adhesion molecule) and cytoskeletal changes without alterations in cell viability were observed. HUVECs were also exposed to Escherichia coli lipopolysaccaride (LPS) as an in vitro model of inflammation: significant IL-6 release was measured. Pre-treatment of HUVECs with aescin prevented, in a concentration-dependent fashion (0.1-1 microM), the action of CoCl2 on VCAM-1 and PECAM-1, also preserving endothelial cell morphology. Furthermore, aescin pre-treatment reduced IL-6 release from LPS-activated vascular endothelium.