Cardiovascular disease (CVD) comprises a range of major clinical cardiac and circulatory diseases, which produce immense health and economic burdens worldwide. Currently, vascular regenerative ...surgery represents the most employed therapeutic option to treat ischemic disorders, even though not all the patients are amenable to surgical revascularization. Therefore, more efficient therapeutic approaches are urgently required to promote neovascularization. Therapeutic angiogenesis represents an emerging strategy that aims at reconstructing the damaged vascular network by stimulating local angiogenesis and/or promoting de novo blood vessel formation according to a process known as vasculogenesis. In turn, circulating endothelial colony-forming cells (ECFCs) represent truly endothelial precursors, which display high clonogenic potential and have the documented ability to originate de novo blood vessels in vivo. Therefore, ECFCs are regarded as the most promising cellular candidate to promote therapeutic angiogenesis in patients suffering from CVD. The current briefly summarizes the available information about the origin and characterization of ECFCs and then widely illustrates the preclinical studies that assessed their regenerative efficacy in a variety of ischemic disorders, including acute myocardial infarction, peripheral artery disease, ischemic brain disease, and retinopathy. Then, we describe the most common pharmacological, genetic, and epigenetic strategies employed to enhance the vasoreparative potential of autologous ECFCs by manipulating crucial pro-angiogenic signaling pathways, e.g., extracellular-signal regulated kinase/Akt, phosphoinositide 3-kinase, and Ca
signaling. We conclude by discussing the possibility of targeting circulating ECFCs to rescue their dysfunctional phenotype and promote neovascularization in the presence of CVD.
We studied the impact of driver mutations of JAK2, CALR, (calreticulin gene) or MPL on clinical course, leukemic transformation, and survival of patients with primary myelofibrosis (PMF). Of the 617 ...subjects studied, 399 (64.7%) carried JAK2 (V617F), 140 (22.7%) had a CALR exon 9 indel, 25 (4.0%) carried an MPL (W515) mutation, and 53 (8.6%) had nonmutated JAK2, CALR, and MPL (so-called triple-negative PMF). Patients with CALR mutation had a lower risk of developing anemia, thrombocytopenia, and marked leukocytosis compared with other subtypes. They also had a lower risk of thrombosis compared with patients carrying JAK2 (V617F). At the opposite, triple-negative patients had higher incidence of leukemic transformation compared with either CALR-mutant or JAK2-mutant patients. Median overall survival was 17.7 years in CALR-mutant, 9.2 years in JAK2-mutant, 9.1 years in MPL-mutant, and 3.2 years in triple-negative patients. In multivariate analysis corrected for age, CALR-mutant patients had better overall survival than either JAK2-mutant or triple-negative patients. The impact of genetic lesions on survival was independent of current prognostic scoring systems. These observations indicate that driver mutations define distinct disease entities within PMF. Accounting for them is not only relevant to clinical decision-making, but should also be considered in designing clinical trials.
•Patients with PMF may carry JAK2 (V617F), a CALR exon 9 indel, an MPL exon 10 mutation, or none of these genetic lesions.•The genetic subtypes of PMF differ substantially as regards clinical course, disease progression, and overall survival.
Prior studies have reported high response rates with recombinant interferon-α (rIFN-α) therapy in patients with essential thrombocythemia (ET) and polycythemia vera (PV). To further define the role ...of rIFN-α, we investigated the outcomes of pegylated-rIFN-α2a (PEG) therapy in ET and PV patients previously treated with hydroxyurea (HU). The Myeloproliferative Disorders Research Consortium (MPD-RC)-111 study was an investigator-initiated, international, multicenter, phase 2 trial evaluating the ability of PEG therapy to induce complete (CR) and partial (PR) hematologic responses in patients with high-risk ET or PV who were either refractory or intolerant to HU. The study included 65 patients with ET and 50 patients with PV. The overall response rates (ORRs; CR/PR) at 12 months were 69.2% (43.1% and 26.2%) in ET patients and 60% (22% and 38%) in PV patients. CR rates were higher in CALR-mutated ET patients (56.5% vs 28.0%; P = .01), compared with those in subjects lacking a CALR mutation. The median absolute reduction in JAK2V617F variant allele fraction was −6% (range, −84% to 47%) in patients achieving a CR vs +4% (range, −18% to 56%) in patients with PR or nonresponse (NR). Therapy was associated with a significant rate of adverse events (AEs); most were manageable, and PEG discontinuation related to AEs occurred in only 13.9% of subjects. We conclude that PEG is an effective therapy for patients with ET or PV who were previously refractory and/or intolerant of HU. This trial was registered at www.clinicaltrials.gov as #NCT01259856.
•Pegylated-rIFN-α2a can achieve an ORR of 69% and 60% in ET and PV patients, respectively, previously treated with hydroxyurea.•The presence of a CALR mutation was associated with superior CR rates in ET patients treated with pegylated-rIFN-α2a.
Display omitted
Primary myelofibrosis (PMF) is a myeloproliferative neoplasm due to the clonal proliferation of a hematopoietic stem cell. The vast majority of patients harbor a somatic gain of function mutation ...either of
or
or
genes in their hematopoietic cells, resulting in the activation of the JAK/STAT pathway. Patients display variable clinical and laboratoristic features, including anemia, thrombocytopenia, splenomegaly, thrombotic complications, systemic symptoms, and curtailed survival due to infections, thrombo-hemorrhagic events, or progression to leukemic transformation. New drugs have been developed in the last decade for the treatment of PMF-associated symptoms; however, the only curative option is currently represented by allogeneic hematopoietic cell transplantation, which can only be offered to a small percentage of patients. Disease prognosis is based at diagnosis on the classical International Prognostic Scoring System (IPSS) and Dynamic-IPSS (during disease course), which comprehend clinical parameters; recently, new prognostic scoring systems, including genetic and molecular parameters, have been proposed as meaningful tools for a better patient stratification. Moreover, new biological markers predicting clinical evolution and patient survival have been associated with the disease. This review summarizes basic concepts of PMF pathogenesis, clinics, and therapy, focusing on classical prognostic scoring systems and new biological markers of the disease.
The expression of the CXCR4 chemokine receptor on CD34-positive blood cells is reduced in persons with primary myelofibrosis (PMF). We analyzed the relevance of cytofluorimetric assessment of the ...percentage of CD34-positive blood cells that had a positive CXCR4 surface expression (CD34/CXCR4-se) in a large cohort of subjects with myeloproliferative neoplasms. Mean CD34/CXCR4-se was lower in subjects with PMF compared with those with essential thrombocythemia (ET) or polycythemia vera (PV). A cutoff value of 39% was associated with a diagnosis of pre-fibrotic PMF vs. ET with a positive predictive value of 97%. In PMF male sex, older age, and MPL mutation were independent correlates of reduced CD34/CXCR4-se and associated with a briefer interval to development of severe anemia, large splenomegaly, thrombocytopenia, leukopenia, elevated CD34-positive blood cells, blast transformation and death. We constructed a prognostic model including age >65 years, hemoglobin < 100 g/L, CD34-positive blood cells > 50 × 10
/L, and CD34/CXCR4-se <39% at diagnosis. The model identified three risk cohorts with greater accuracy compared with the International Prognostic Scoring System. In conclusion, CD34/CXCR4-se is a highly sensitive marker of disease activity and a new potential diagnostic and prognostic biomarker in PMF.
An increase in intracellular Ca2+ concentration plays a key role in the establishment of many cancer hallmarks, including aberrant proliferation, migration, invasion, resistance to apoptosis and ...angiogenesis. The dysregulation of Ca2+ entry is one of the most subtle mechanisms by which cancer cells overwhelm their normal counterparts and gain the adaptive advantages that result in tumour growth, vascularisation and dissemination throughout the organism. Both constitutive and agonist-induced Ca2+ influx may be mediated by store-dependent as well as store-independent Ca2+ entry routes. A growing body of evidences have shown that different isoforms of Stromal Interaction Molecules (Stim1) and Orai proteins, i.e. Stim1, Stim2, Orai1 and Orai3, underlie both pathways in cancer cells. The alteration in either the expression or the activity of Stim and Orai proteins has been linked to the onset and maintenance of tumour phenotype in many solid malignancies, including prostate, breast, kidney, esophageal, skin, brain, colorectal, lung and liver cancers. Herein, we survey the existing data in support of Stim and Orai involvement in tumourigenesis and provide the rationale to target them in cancer patients. Besides, we summarize the most recent advances in the identification of novel pharmacological tools that could be successfully used in clinical therapy.
The fibronectin EDA isoform (EDA FN) is instrumental in fibrogenesis but, to date, its expression and function in bone marrow (BM) fibrosis have not been explored. We found that mice constitutively ...expressing the EDA domain (EIIIA
), but not EDA knockout mice, are more prone to develop BM fibrosis upon treatment with the thrombopoietin (TPO) mimetic romiplostim (TPO
). Mechanistically, EDA FN binds to TLR4 and sustains progenitor cell proliferation and megakaryopoiesis in a TPO-independent fashion, inducing LPS-like responses, such as NF-κB activation and release of profibrotic IL-6. Pharmacological inhibition of TLR4 or TLR4 deletion in TPO
mice abrogated Mk hyperplasia, BM fibrosis, IL-6 release, extramedullary hematopoiesis, and splenomegaly. Finally, developing a novel ELISA assay, we analyzed samples from patients affected by primary myelofibrosis (PMF), a well-known pathological situation caused by altered TPO signaling, and found that the EDA FN is increased in plasma and BM biopsies of PMF patients as compared with healthy controls, correlating with fibrotic phase.
The paracrine properties of human amniotic membrane‐derived mesenchymal stromal cells (hAMCs) have not been fully elucidated. The goal of the present study was to elucidate whether hAMCs can exert ...beneficial paracrine effects on infarcted rat hearts, in particular through cardioprotection and angiogenesis. Moreover, we aimed to identify the putative active paracrine mediators. hAMCs were isolated, expanded, and characterized. In vitro, conditioned medium from hAMC (hAMC‐CM) exhibited cytoprotective and proangiogenic properties. In vivo, injection of hAMC‐CM into infarcted rat hearts limited the infarct size, reduced cardiomyocyte apoptosis and ventricular remodeling, and strongly promoted capillary formation at the infarct border zone. Gene array analysis led to the identification of 32 genes encoding for the secreted factors overexpressed by hAMCs. Among these, midkine and secreted protein acidic and rich in cysteine were also upregulated at the protein level. Furthermore, high amounts of several proangiogenic factors were detected in hAMC‐CM by cytokine array. Our results strongly support the concept that the administration of hAMC‐CM favors the repair process after acute myocardial infarction.
The goal of this study was to elucidate whether human amniotic membrane‐derived mesenchymal stromal cells (hAMCs) can exert beneficial paracrine effects on infarcted rat hearts. In particular, the administration of hAMC‐conditioned medium repaired ischemic damage through cardioprotection and angiogenesis. Finally, several putative active paracrine mediators that might account for the effects observed were identified by gene and protein arrays.
Therapeutic angiogenesis represents an emerging strategy to treat ischemic diseases by stimulating blood vessel growth to rescue local blood perfusion. Therefore, injured microvasculature may be ...repaired by stimulating resident endothelial cells or circulating endothelial colony forming cells (ECFCs) or by autologous cell-based therapy. Endothelial Ca
signals represent a crucial player in angiogenesis and vasculogenesis; indeed, several angiogenic stimuli induce neovessel formation through an increase in intracellular Ca
concentration. Several members of the Transient Receptor Potential (TRP) channel superfamily are expressed and mediate Ca
-dependent functions in vascular endothelial cells and in ECFCs, the only known truly endothelial precursor. TRP Vanilloid 1 (TRPV1), a polymodal cation channel, is emerging as an important player in endothelial cell migration, proliferation, and tubulogenesis, through the integration of several chemical stimuli. Herein, we first summarize TRPV1 structure and gating mechanisms. Next, we illustrate the physiological roles of TRPV1 in vascular endothelium, focusing our attention on how endothelial TRPV1 promotes angiogenesis. In particular, we describe a recent strategy to stimulate TRPV1-mediated pro-angiogenic activity in ECFCs, in the presence of a photosensitive conjugated polymer. Taken together, these observations suggest that TRPV1 represents a useful target in the treatment of ischemic diseases.
PDF
