Simple Detection of Unstained Live Senescent Cells with Imaging Flow Cytometry.

Cellular senescence is a hallmark of aging and a promising target for therapeutic approaches. The identification of senescent cells requires multiple biomarkers and complex experimental procedures, resulting in increased variability and reduced sensitivity. Here, we propose a simple and broadly applicable imaging flow cytometry (IFC) method. This method is based on measuring autofluorescence and morphological parameters and on applying recent artificial intelligence (AI) and machine learning (ML) tools. We show that the results of this method are superior to those obtained measuring the classical senescence marker, senescence-associated beta-galactosidase (SA-ß-Gal). We provide evidence that this method has the potential for diagnostic or prognostic applications as it was able to detect senescence in cardiac pericytes isolated from the hearts of patients affected by end-stage heart failure. We additionally demonstrate that it can be used to quantify senescence "in vivo" and can be used to evaluate the effects of senolytic compounds. We conclude that this method can be used as a simple and fast senescence assay independently of the origin of the cells and the procedure to induce senescence.

Impaired mitochondrial quality control in Rett Syndrome.

Rett Syndrome (RTT) is a rare neurodevelopmental disorder caused in the 95% of cases by mutations in the X-linked MECP2 gene, affecting almost exclusively females. While the genetic basis of RTT is known, the exact pathogenic mechanisms that lead to the broad spectrum of symptoms still remain enigmatic. Alterations in the redox homeostasis have been proposed among the contributing factors to the development and progression of the syndrome. Mitochondria appears to play a central role in RTT oxidative damage and a plethora of mitochondrial defects has already been recognized. However, mitochondrial dynamics and mitophagy, which represent critical pathways in regulating mitochondrial quality control (QC), have not yet been investigated in RTT. The present work showed that RTT fibroblasts have networks of hyperfused mitochondria with morphological abnormalities and increased mitochondrial volume. Moreover, analysis of mitophagic flux revealed an impaired PINK1/Parkin-mediated mitochondrial removal associated with an increase of mitochondrial fusion proteins Mitofusins 1 and 2 (MFN1 and 2) and a decrease of fission mediators including Dynamin related protein 1 (DRP1) and Mitochondrial fission 1 protein (FIS1). Finally, challenging RTT fibroblasts with FCCP and 2,4-DNP did not trigger a proper apoptotic cell death due to a defective caspase 3/7 activation. Altogether, our findings shed light on new aspects of mitochondrial dysfunction in RTT that are represented by defective mitochondrial QC pathways, also providing new potential targets for a therapeutic intervention aimed at slowing down clinical course and manifestations in the affected patients.

Heart failure impairs the mechanotransduction properties of human cardiac pericytes.

The prominent impact that coronary microcirculation disease (CMD) exerts on heart failure symptoms and prognosis, even in the presence of macrovascular atherosclerosis, has been recently acknowledged. Experimental delivery of pericytes in non-revascularized myocardial infarction improves cardiac function by stimulating angiogenesis and myocardial perfusion. Aim of this work is to verify if pericytes (Pc) residing in ischemic failing human hearts display altered mechano-transduction properties and to assess which alterations of the mechano-sensing machinery are associated with the observed impaired response to mechanical cues. RESULTS: Microvascular rarefaction and defects of YAP/TAZ activation characterize failing human hearts. Although both donor (D-) and explanted (E-) heart derived cardiac Pc support angiogenesis, D-Pc exert this effect significantly better than E-Pc. The latter are characterized by reduced focal adhesion density, decreased activation of the focal adhesion kinase (FAK)/ Crk-associated substrate (CAS) pathway, low expression of caveolin-1, and defective transduction of extracellular stiffness into cytoskeletal stiffening, together with an impaired response to both fibronectin and lysophosphatidic acid. Importantly, Mitogen-activated protein kinase kinase inhibition restores YAP/TAZ nuclear translocation. CONCLUSION: Heart failure impairs Pc mechano-transduction properties, but this defect could be reversed pharmacologically.

Cell Senescence in Cardiac Repair and Failure.

Although the lack of a robust cardiomyocyte proliferative response has been considered to be a crucial determinant of cardiac pathology and Heart Failure in adult mammalians, the emerging picture is that myocardial regeneration is a complex phenotype involving many actors, including acute cellular senescence and inflammation. However, three major and interconnected events occur in response to tissue injury: loss of protein homeostasis, accumulation of dysfunctional mitochondria and chronic inflammation. These events blunt the reparative response of the heart, are associated with the accumulation of chronically senescent cells and progressively lead to cardiac dysfunction. Therefore, it is crucial to understand which are the pivotal players of this process, in order to devise strategies aimed at reducing the occurrence of chronic cell senescence in the heart in vivo.

Interpreting neonatal hip sonography: intraobserver and interobserver variability.

The purpose of this study is to state the reliability of neonatal hip ultrasound interpretation, defining the intra and interoperator variability in the evaluation of the scans. We considered a sample of 2071 scans (coming from 798 patients who attended the screening programme for hip dysplasia), which were interpreted by the operator who obtained and read the images at the screening time and then by a different operator who saw the images for the first time. Both the intra and interoperator variability of α and ß angles' values resulted statistically not significative (intraclass correlation coefficient > 0.8) and determining a class shift (according to the Graf's classification) in a nonstatistically significative number of cases (agreement percentage >91% and Cohen's κ >0.8). Hip sonography can reliably detect hip dysplasia and the intra and interoperator variability in the interpretation of the exam is NS when the examination is correctly executed.

Paraoxonase, arylesterase and lactonase activities of paraoxonase-1 (PON1) in obese and severely obese women.

Obesity is independently associated with disturbances in lipid and lipoprotein metabolism, oxidative stress, and is a well-established independent risk factor for cardiovascular diseases (CVD). Human paraoxonase 1 (PON1) is a pleotropic high-density lipoprotein (HDL)-associated enzyme with antioxidant and anti-inflammatory proprieties that have been suggested to contribute to the athero-protective function of the lipoprotein. The aim of this study was to investigate whether obesity is associated with PON1 activity and whether this association is influenced by oxidative stress, inflammation and HDL cholesterol (HDL-C) concentration. The promiscuous activities, arylesterase and paraoxonase, and the putative physiological activity, lactonase, of PON1 were assessed in the serum of 214 obese and severely obese, 101 overweight and 129 normal-weight women. Levels of high-sensitivity C-reactive protein (hs-CRP), hydroperoxides (by-products of lipid oxidative damage) and lipid profiles were also evaluated. Arylesterase activity was the only activity that significantly differed across the groups (ANOVA, p < .01), with the greatest decrease observed in individuals with body mass index (BMI) > 40 kg/m2 compared to controls (p < .001). This activity was also inversely, although weakly (r = -0.160, p < .001) correlated with the BMI, and the association was independent of age and levels of oxidative stress and inflammation, but not of HDL-C concentration. In conclusion, our results suggest that the apparent obesity-associated decrement of PON1 activity might simply reflect the decrease in concentration of its plasmatic carrier.

VDR, RANKL and OPG polymorphisms as possible predisposing cofactors of postmenopausal osteoporosis: explorative study in Italian population.

Postmenopausal osteoporosis (PO) has a strong genetic component. Presently, the published evidence on the association between the main single-nucleotide polymorphisms (SNPs) of the receptor activator of nuclear factor-kb ligand (RANKL), osteoprotegerin (OPG) and vitamin D receptor (VDR) and bone mass density (BMD) are scarce, mostly considering Italian population. This study sought to determine whether OPG (rs2073618), RANKL (rs9525641) and the VDR (rs2228570) SNPs were associated with BMD in a sample of 139 North-Italian postmenopausal women. The allelic distribution of rs9525641 in women with PO or osteopenia (OP + OPE group) differed from controls (p < 0.05), suggesting that this allele might confer a greater susceptibility to bone resorption. Concerning rs2228570, CC genotype was associated with OP + OPE women, with a worst total hip BMD. Notably, the combined genotype RANK (CT)-VDR (TT) was significantly associated to spine BMD (p < 0.05). In conclusion, this pilot study showed that rs9525641 and rs2228570 polymorphisms might contribute, separately or in combination, in determining BMD phenotype in selected postmenopausal populations.

Lactonase Activity and Lipoprotein-Phospholipase A2 as Possible Novel Serum Biomarkers for the Differential Diagnosis of Autism Spectrum Disorders and Rett Syndrome: Results from a Pilot Study.

Rett syndrome (RTT) and autism spectrum disorders (ASDs) are not merely expression of brain dysfunction but also reflect the perturbation of physiological/metabolic homeostasis. Accordingly, both disorders appear to be associated with increased vulnerability to toxicants produced by redox imbalance, inflammation, and pollution, and impairment of systemic-detoxifying agents could play a role in the exacerbation of these detrimental processes. To check this hypothesis, the activities of two mechanistically related blood-based enzymes, paraoxonase-1 (arylesterase, paraoxonase, and lactonase), and lipoprotein-associated phospholipase A2 (Lp-PLA2) were measured in the serum of 79 ASD and 95 RTT patients, and 77 controls. Lactonase and Lp-PLA2 showed a similar trend characterized by significantly lower levels of both activities in ASD compared to controls and RTT (p < 0.001 for all pairwise comparisons). Noteworthy, receiving operator curve (ROC) analysis revealed that lactonase and, mostly, Lp-PLA2 were able to discriminate between ASD and controls (lactonase: area under curve, AUC = 0.660; Lp-PLA2, AUC = 0.780), and, considering only females, between ASD and RTT (lactonase, AUC = 0.714; Lp-PLA2, AUC = 0.881). These results suggest that lactonase and, especially, Lp-PLA2 activities might represent novel candidate biomarkers for ASD.

SRB1 as a new redox target of cigarette smoke in human sebocytes.

For its critical location, the skin represents the major interface between the body and the environment, therefore is one of the major biological barriers against the outdoor environmental stressors. Among the several oxidative environmental stressors, cigarette smoke (CS) has been associated with the development and worsening of many skin pathologies such as acne, dermatitis, delayed wound healing, aging and skin cancer. In our previous work we have demonstrated that CS is able to affect genes involved in skin cholesterol trafficking, among which SRB1, a receptor involved in the uptake of cholesterol from HDL, seems to be very susceptible to the oxidative stress induced by CS. In the present work we wanted to investigate the presence of SRB1 in human sebocytes and whether CS can affect cholesterol cellular uptake via the redox modulation of SRB1. By using a co-culture system of keratinocytes/sebocytes, we found that CS exposure induced a SRB1 protein loss without affecting sebocytes viability. The decrease of SRB1 levels was a consequence of SRB1/HNE adducts formation that leads to SRB1 ubiquitination and degradation. Moreover, the CS-induced loss of SRB1 induced an alteration of sebocytes lipid content, also demonstrated by cholesterol quantification in SRB1 siRNA experiments. In conclusion, exposure to CS, induced SRB1 post-translational modifications in sebocytes and this might affect sebocytes/skin functionality.

Evaluation of bone density in infancy and adolescence. Review of medical literature and personal experience.

The evolution of medical and surgical therapies allows the increased survival rate of a growing number of children affected by rare pathologies. In this light osteoporotic disease is also of orthopaedic interest as it is sometimes the outward manifestation of serious pathologies (i.e. osteogenesis imperfecta). Sometimes, even in infancy and adolescence, osteoporosis is associated with complications due to fractures; in other cases it seems to have no immediate consequence. Nevertheless it must be considered as a fracture risk factor in adulthood as it negatively affects the achievement of peak bone mass. The evaluation of variations in bone mass that take place during growth is thus of particular importance in order to guarantee a level of bone health suitable for the next phase. These remarks compose the premise of a study on bone resistance carried out on a study population of between 6 and 18 years of age in the city of Pavia. To determine the resistance of the bone an ultrasound device was employed (Omnisense™ , Sunlight Medical Ltd, Tel Aviv, Israel) in two skeletal sites, distal radius and midshaft of tibia. The analysis of our results and a review of the relevant literature indicate that the median values of normality, against which we compare the measurements of the patients under examination, depend not only on age, sex, skeletal sites, race, and even ethnic group. The introduction of this new parameter, to be kept in mind when interpreting the results, invites us to be very prudent in determining the diagnostic threshold values in paediatric age. As with anthropometric data (weight, height, cranial circumference) it is possible to suggest an interpretation of the patient's SOS values comparing them with the 'centile curves' typical to the region the child belongs to. Of course, further studies are required to understand what are the variables involved and to determine the extension of the geographical area to be examined to obtain suitable reference curves.