Raffaella Lazzarini

Diagnostic potential of circulating miR-499-5p in elderly patients with acute non ST-elevation myocardial infarction

BACKGROUND Geriatric patients with acute non-ST elevation myocardial infarction (NSTEMI) can frequently present atypical symptoms and non-diagnostic electrocardiogram. The detection of modest cardiac troponin T (cTnT) elevation is challenging for physicians needing to routinely triage these patients. Unfortunately, non-coronary diseases, such as acute heart failure (CHF), may cause cTnT elevation. Circulating microRNAs (miRs) have emerged as biomarkers of MI. However, their diagnostic potential needs to be determined in elderly NSTEMI patients. METHODS 92 NSTEMI patients (82.6 ± 6.9 years old; complicated by CHF in 74% of cases) and 81 patients with acute CHF without AMI (81.3 ± 6.8 years old) were enrolled at presentation. A third group comprised 99 age-matched healthy control subjects (CTR). Plasma levels of miR-1, -21, -133a, -208a, -423-5p and -499-5p were analyzed. RESULTS MiR-1, -21 -133a and -423-5p showed a 3- to 10-fold increase and miR-499-5p exhibited >80-fold increase in acute NSTEMI patient vs. CTR. MiR-499-5p and -21 showed a significantly increased expression in NSTEMI vs. CHF. Interestingly, mir-499-5p was comparable to cTnT in discriminating NSTEMI vs. CTR and CHF patients. Its diagnostic accuracy was higher than conventional and hs-cTnT in differentiating NSTEMI (n=31) vs. acute CHF (n=32) patients with modest cTnT elevation at presentation (miR-499-5p AUC=0.86 vs. cTnT AUC=0.68 and vs. hs-cTnT AUC=0.70). CONCLUSIONS Circulating miR-499-5p is a sensitive biomarker of acute NSTEMI in the elderly, exhibiting a diagnostic accuracy superior to that of cTnT in patients with modest elevation at presentation.

Age-related differences in the expression of circulating microRNAs: miR-21 as a new circulating marker of inflammaging

Circulating microRNAs (miRs) have been investigated as diagnostic/prognostic biomarkers in human diseases. However, little is known about their expression throughout the aging process. Eleven healthy individuals aged 20, 80 and 100 years underwent miR plasma profiling. The validation cohort consisted of 111 healthy adults (CTR) aged 20-105 years and included 30 centenarians. In addition, 34 patients with cardiovascular disease (CVD) and 15 healthy centenarian offspring (CO) were enrolled. An exploratory factorial analysis grouped the miRs into three main factors: factor 1 primarily higher in 20-year-old subjects, but these differences did not reach statistical significance, factor 2 primarily higher in octogenarians and factor 3 primarily higher in centenarians. MiR-21, the most highly expressed miR of factors 2 and 3, was further validated, confirming the differences in the age groups. MiR-21 expression was higher in the CVD patients and lower in the CO compared to the age-matched CTR. MiR-21 was correlated with C-reactive protein and fibrinogen levels. TGF-β signaling was the predicted common pathway targeted by miRs of factors 2 and 3. TGF-βR2 mRNA, a validated miR-21 target, showed the highest expression in the leukocytes from a subset of the octogenarians. Our findings suggest that miR-21 may be a new biomarker of inflammation.

MiR-146a as marker of senescence-associated pro-inflammatory status in cells involved in vascular remodelling

In order to identify new markers of vascular cell senescence with potential in vivo implications, primary cultured endothelial cells, including human umbilical vein endothelial cells (HUVECs), human aortic endothelial cells (HAECs), human coronary artery endothelial cells (HCAECs) and ex vivo circulating angiogenic cells (CACs), were analysed for microRNA (miR) expression. Among the 367 profiled miRs in HUVECs, miR-146a, miR-9, miR-204 and miR-367 showed the highest up-regulation in senescent cells. Their predicted target genes belong to nine common pathways, including Toll-like receptor signalling (TLR) that plays a pivotal role in inflammatory response, a key feature of senescence (inflammaging). MiR-146a was the most up-regulated miR in the validation analysis (>10-fold). Mimic and antagomir transfection confirmed TLR’s IL-1 receptor-associated kinase (IRAK1) protein modulation in both young and senescent cells. Significant correlations were observed among miR-146a expression and β-galactosidase expression, telomere length and telomerase activity. MiR-146a hyper-expression was also validated in senescent HAECs (>4-fold) and HCAECs (>30-fold). We recently showed that CACs from patients with chronic heart failure (CHF) presented a distinguishing feature of senescence. Therefore, we also included miR-146a expression determination in CACs from 37 CHF patients and 35 healthy control subjects (CTR) for this study. Interestingly, a 1,000-fold increased expression of miR-146a was observed in CACs of CHF patients compared to CTR, along with decreased expression of IRAK1 protein. Moreover, significant correlations among miR-146a expression, telomere length and telomerase activity were observed. Overall, our findings indicate that miR-146a is a marker of a senescence-associated pro-inflammatory status in vascular remodelling cells.

Aged-related increase of high sensitive Troponin T and its implication in acute myocardial infarction diagnosis of elderly patients

High sensitive cardiac Troponin T (hs-cTnT) represents an important tool in acute myocardial infarction (AMI) diagnosis. Even though the hs-cTnT evaluation is relevant for AMI diagnosis in elderly patients characterized by clinical and instrumental atypical presentation, the overall reliability in elderly patients is unknown. We aimed at: (1) defining the hs-cTnT 99th percentile value in an aged healthy reference population and (2) testing hs-cTnT diagnostic accuracy in elderly patients with a suspected AMI. 294 healthy subjects (50-105 years old) and 299 elderly patients (75-96 years old) with suspected AMI at presentation, were enrolled. Conventional cTnT, hs-cTnT, NT-proBNP and creatinine levels were determined in all participants. Our main results are: (1) a significant hs-cTnT age-related increase was observed in an healthy reference population ranging 50-105 years old; (2) hs-cTnT levels showed an age-related multimodal distribution in the healthy reference population: 16 ng/L corresponds to the 99th percentile in subjects ranging 50-75 years old, whereas 70.6 ng/L corresponds to the 99th percentile in subjects ≥75 years old; (3) 86.8 ng/L resulted the hs-cTnT cut-off value with the highest efficiency in AMI diagnosis of geriatric patients. Our data suggest that the hs-cTnT cut-off value must be age-tailored to improve the AMI diagnostic accuracy.

The Plexin-A1 Receptor Activates Vascular Endothelial Growth Factor-Receptor 2 and Nuclear Factor-κB to Mediate Survival and Anchorage-Independent Growth of Malignant Mesothelioma Cells

The semaphorins and their receptors, the neuropilins and the plexins, are constituents of a complex regulatory system that controls axonal guidance. Moreover, many types of tumor cells express various members of semaphorins and receptors, but the biological activities within tumor mass and the signal transduction mechanism(s) they use are largely unknown. Here, we show that in asbestos-related malignant pleural mesothelioma (MPM), Semaphorin-6D (Sema6D) and its receptor plexin-A1 are frequently expressed and trigger a prosurvival program that promotes anchorage-independent growth of MPM cells. Interestingly, the same response is also controlled by the tyrosine kinase receptors of vascular endothelial growth factor (VEGF) through a nuclear factor-kappaB (NF-kappaB)-dependent pathway. We found that in MPM cells, plexin-A1 and VEGF-receptor 2 (VEGF-R2) are associated in a complex. Moreover, the presence of Sema6D promotes the tyrosine phosphorylation of VEGF-R2 in a plexin-A1-dependent manner. This is necessary for basal and Sema6D-induced NF-kappaB transcriptional activity, and NF-kappaB mediates tumor cell survival. Expression of Sema6D and plexin-A1 is induced by asbestos fibers and overexpression of plexin-A1 in nonmalignant mesothelial cells inhibits cell death after asbestos exposure. This work identifies a new biological function of semaphorins in cancer cells and suggests the involvement of an undescribed survival pathway during MPM tumorigenesis.

MiR-21-5p and miR-126a-3p levels in plasma and circulating angiogenic cells: relationship with type 2 diabetes complications

Innovative biomarkers are required to manage type 2 diabetic patients (T2DM). We focused our study on miR-126-3p and miR-21-5p levels, as biomarkers of endothelial function and inflammation. MiRNAs levels were measured in plasma from 107 healthy subjects (CTR) and 193 diabetic patients (T2DM), 76 without (T2DM NC) and 117 with (T2DM C) complications. When diabetic complication were analysed as a whole, miR-126-3p and miR-21-5p levels declined significantly from CTR to T2DM NC and T2DM C patients. When miRNAs levels were related to specific complications, significantly higher miR-21-5p levels (0.46 ± 0.44 vs. 0.26±0.33, p < 0.001) and significant lower miR-126-3p levels (0.21±0.21 vs. 0.28±0.22, p = 0.032) were found in T2DM with previous major cardiovascular events (MACE) vs. all the others T2DM patients. To confirm these results we focused on circulating angiogenic cells (CACs) from a subgroup of 10 CTR, 15 T2DM NC and 15 T2DM patients with MACE. CACs from T2DM patients expressed higher miR-21-5p and lower miR-126-3p levels than CACs from CTR. Furthermore, CACs from T2DM + MACE showed the highest levels of miR-21-5p. Circulating miR-21-5p and miR-126-3p emerge as dynamic biomarkers of systemic inflammatory/angiogenic status. Their expression levels in CACs from T2DM with MACE suggest a shift from a proangiogenic to a proinflammatory profile.

Enhanced Antitumor Therapy by Inhibition of p21waf1 in Human Malignant Mesothelioma

Purpose: The p21 cyclin-dependent kinase inhibitor was frequently expressed in human malignant pleural mesothelioma (MPM) tissues as well as cell lines. Recent data indicate that p21 keeps tumor cells alive after DNA damage, favoring a survival advantage. In this study, we assessed the possibility of p21 suppression as a therapeutic target for MPM. Experimental Design: We established two different MPM-derived (from H28 and H2052 cells) subclones using vector-based short hairpin RNA (shRNA). Then, chemosensitivity against low doses of antineoplastic DNA-damaging agents was investigated by colony formation assays, and furthermore, the type of cell response induced by these drugs was analyzed. To examine the effect of p21 shRNA on chemosensitivity in vivo, tumor formation assays in nude mice were done. Results: In colony formation assay, the IC50 of doxorubicin was 33 ± 3.0 nmol/L in p21 shRNA-transfected cells with respect to 125 ± 10 nmol/L of control vector–transfected cells. This enhancement of growth inhibition was achieved by converting a senescence-like growth arrest to apoptosis in response to doxorubicin, etoposide, and CPT11. In the in vivo assays, CPT11 and loss-of-expression of p21 in combination led to considerable suppression of tumor growth associated with a substantially enhanced apoptotic response, whereas CPT11 alone was ineffective at inducing these responses. Conclusions: These results indicated that p21 might play an important role in chemosensitivity to anticancer agents, and the suppression of its expression might be a potential therapeutic target for MPM.

Characterization and profiling of immunomodulatory genes in resident mesenchymal stem cells reflect the Th1-Th17/Th2 imbalance of psoriasis.

The expression of genes encoding for Th1, Th2 and Th17 cytokines has been extensively evaluated in differentiated skin cells of psoriatic patients. The microenvironment exerts a control on the phenotype of resident mesenchymal stem cells (MSCs) into the skin of psoriasis patients. Aim of the study was to extensively evaluate the relative expression of 43 genes encoding for Th1, Th2 and Th17 cytokines in MSCs isolated from skin of psoriasis patients. MSCs resident into psoriatic skin were isolated, characterized and profiled by PCR array for the relative expression of genes encoding for cytokines involved in Th1, Th2 and Th17 pathways. MSCs isolated from the skin of healthy subjects were used as control. The MSCs isolated from skin of psoriasis patients showed a greater relative expression of the most part of the analyzed genes encoding for Th1 and Th17 cytokines: INF-γ, CCR5, CXCL9, CXCL10, IL6, IL8, TNF-α, IL23A, CCL2, CCL20, CXCL2, CXCL5, IL17C, IL17F, IL17RA, IL21, TLR2 than healthy subjects. On the contrary, the relative expression of genes encoding for Th2 cytokines: CCL1, CCL22, CXCL12, IL2, IL3, IL4, IL13B, IL 22, IL 27, TGF-β1, was similar between the MSCs isolated from psoriasis and healthy subjects. In conclusion, the MSCs isolated from psoriasis show an imbalance between the Th1-Th17 and Th2 pathways, which reflects the well-known abnormal balance observed in differentiated skin cells. This evidence could strengthen the hypothesis of an early involvement of resident MSCs in the pathogenesis of psoriasis.

Anti-inflammatory effect of ubiquinol-10 on young and senescent endothelial cells via miR-146a modulation

Clinical evidence demonstrates that ubiquinol-10, the reduced active form of coenzyme Q10 (CoQ10H₂), improves endothelial function through its antioxidant and probably its anti-inflammatory properties. We previously reported that a biomarker combination including miR-146a, its target protein IL-1 receptor-associated kinase (IRAK-1), and released interleukin (IL)-6, here collectively designated as MIRAKIL, indicates senescence-associated secretory phenotype (SASP) acquisition by primary human umbilical vein endothelial cells (HUVECs). We explore the ability of short- and long-term CoQ10H₂ supplementation to affect MIRAKIL in HUVECs, used as a model of vascular aging, during replicative senescence in the absence/presence of lipopolysaccharide (LPS), a proinflammatory stimulus. Senescent HUVECs had the same ability as young cells to internalize CoQ10 and exhibit an improved oxidative status. LPS-induced NF-κB activation diminished after CoQ10H₂ pretreatment in both young and senescent cells. However, short-term CoQ10H₂ supplementation attenuated LPS-induced MIRAKIL changes in young cells; in senescent cells CoQ10H₂ supplementation significantly attenuated LPS-induced miR-146a and IRAK-1 modulation but failed to curb IL-6 release. Similar results were obtained with long-term CoQ10H₂ incubation. These findings provide new insights into the molecular mechanisms by which CoQ10H₂ stems endothelial cell inflammatory responses and delays SASP acquisition. These phenomena may play a role in preventing the endothelial dysfunction associated with major age-related diseases.

Isolation and characterization of progenitor mesenchymal cells in human pituitary tumors.

The Cancer Stem Cells (CSCs) theory suggests that genetic alterations in stem cells are the direct cause for cancer. The evidence for a CSC population that results in pituitary tumors is poor. Some studies report the isolation of CSCs, but a deep characterization of the stemness of these cells is lacking. Here, we report the isolation and detailed characterization of progenitor mesenchymal cells (PMCs) from both growth hormone-secreting (GH+) and non-secreting (NS) pituitary adenomas, determining the immunophenotype, the expression of genes related to stemness or to pituitary hormone cell types, and the differentiative potential towards osteo-, chondro- and adipogenic lineages. Finally, the expression of CD133, known as a marker for CSCs in other tumors, was analyzed. Isolated cells, both from GH+ and NS tumors, satisfy all the criteria for the identification of PMCs and express known stem cell markers (OCT4, SOX2, KLF4, NANOG), but do not express markers of pituitary hormone cell types (PITX2, PROP1, PIT1). Finally, PMCs express CD133. We demonstrated that pituitary tumors contain a stem cell population that can generate cell types characteristic of mesenchymal stem cells, and express CD133, which is associated with CSCs in other tumors.