5 research outputs found
The pro-healing effects of heparan sulfate and growth factors are enhanced by the heparinase enzyme: New association for skin wound healing treatment
: Effective treatment strategies for skin wound repair are the focus of numerous studies. New pharmacological approaches appear necessary to guarantee a correct and healthy tissue regeneration. For these reasons, we purposed to investigate the effects of the combination between heparan sulfate and growth factors further adding the heparinase enzyme. Interestingly, for the first time, we have found that this whole association retains a marked pro-healing activity when topically administered to the wound. In detail, this combination significantly enhances the motility and activation of the main cell populations involved in tissue regeneration (keratinocytes, fibroblasts and endothelial cells), compared with single agents administered without heparinase. Notably, using an experimental C57BL/6 mouse model of skin wounding, we observed that the topical treatment of skin lesions with heparan sulfate + growth factors + heparinase promotes the highest closure of wounds compared to each substance mixed with the other ones in all the possible combinations. Eosin/hematoxylin staining of skin biopsies revealed that treatment with the whole combination allows the formation of a well-structured matrix with numerous new vessels. Confocal analyses for vimentin, FAP1α, CK10 and CD31 have highlighted the presence of activated fibroblasts, differentiated keratinocytes and endothelial cells at the closed region of wounds. Our results encourage defining this combined treatment as a new and appealing therapy expedient in skin wound healing, as it is able to activate cell components and promote a dynamic lesions closure
A preliminary study of endocannabinoid system regulation in psychosis: Distinct alterations of CNR1 promoter DNA methylation in patients with schizophrenia
Compelling evidence supports the involvement of the endocannabinoid system (ECS) in psychosis vulnerability. We here evaluated the transcriptional regulation of ECS components in human peripheral blood mononuclear cells (PBMCs) obtained from subjects suffering from bipolar disorder, major depressive disorder and schizophrenia, focusing in particular on the effects of DNA methylation. We observed selective alterations of DNA methylation at the promoter of CNR1, the gene coding for the type-1 cannabinoid receptor, in schizophrenic patients (N = 25) with no changes in any other disorder. We confirmed the regulation of CNR1 in a well-validated animal model of schizophrenia, induced by prenatal methylazoxymethanol (MAM) acetate exposure (N = 7 per group) where we found, in the prefrontal cortex, a significant increase in CNR1 expression and a consistent reduction in DNA methylation at specific CpG sites of gene promoter. Overall, our findings suggest a selective dysregulation of ECS in psychosis, and highlight the evaluation of CNR1 DNA methylation levels in PBMCs as a potential biomarker for schizophrenia
Regulation of gene transcription in bipolar disorders: Role of DNA methylation in the relationship between prodynorphin and brain derived neurotrophic factor
Bipolar Disorder (BD) is a prevalent and disabling condition, determined by gene-environment interactions, possibly mediated by epigenetic mechanisms. The present study aimed at investigating the transcriptional regulation of BD selected target genes by DNA methylation in peripheral blood mononuclear cells of patients with a DSM-5 diagnosis of type I (BD-I) and type II (BD-II) Bipolar Disorders (n = 99), as well as of healthy controls (CT, n = 42). The analysis of gene expression revealed prodynorphin (PDYN) mRNA levels significantly reduced in subjects with BD-II but not in those with BD-I, when compared to CT. Other target genes (i.e. catechol-O-methyltransferase (COMT), glutamate decarboxylase (GAD67), serotonin transporter (SERT) mRNA levels remained unaltered. Consistently, an increase in DNA methylation at PDYN gene promoter was observed in BD-II patients vs CT. After stratifying data on the basis of pharmacotherapy, patients on mood-stabilizers (i.e., lithium and anticonvulsants) were found to have lower DNA methylation at PDYN gene promoter. A significantly positive correlation in promoter DNA methylation was observed in all subjects between PDYN and brain derived neurotrophic factor (BDNF), whose methylation status had been previously found altered in BD. Moreover, among key genes relevant for DNA methylation establishment here analysed, an up-regulation of DNA Methyl Transferases 3b (DNMT3b) and of the methyl binding protein MeCP2 (methyl CpG binding protein 2) mRNA levels was also observed again just in BD-II subjects. A clear selective role of DNA methylation involvement in BD-II is shown here, further supporting a role for BDNF and its possible interaction with PDYN. These data might be relevant in the pathophysiology of BD, both in relation to BDNF and for the improvement of available treatments and development of novel ones that modulate epigenetic signatures
Evaluating Students' Evaluations *
Abstract This paper contrasts measures of teacher effectiveness with the students' evaluations for the same teachers using administrative data from Bocconi University (Italy). The effectiveness measures are estimated by comparing the subsequent performance -both in follow-on coursework and in the labor market -of students who are randomly assigned to teachers in each of their compulsory courses. We find that, even in a setting where the syllabuses are fixed and all teachers in the same course present exactly the same material, teachers still matter substantially. The average difference in subsequent performance between students who were assigned to the best and worst teacher (on the effectiveness scale) is approximately 23% of a standard deviation in the distribution of exam grades, corresponding to over 3% of the average grade. Moreover, teacher effectiveness appears to be negatively correlated with the students' evaluations; in other words, teachers who are associated with better subsequent performance receive worst evaluations from their students. On the other hand, teachers who are associated with high grades in their own exam are associated with good evaluations. We rationalize these results with a simple model where teachers can either engage in real teaching or teach to the test, the former requiring higher students' effort than the latter. Teaching to the test guarantees high grades in the current course but does not improve future outcomes. Hence, if students provide higher evaluations to courses in which they get higher grades, the model is capable of predicting our empirical finding that good teachers get bad evaluations, especially when teaching to the test is very effective (for example, with multiple choice tests). Consistently with the predictions of the model, we also find that classes in which high-skill students are over-represented produce evaluations that are more in line with estimated teacher effectiveness. JEL Codes: I2