Application of Induced Pluripotent Stem Cell Technology to the Study of Hematological Diseases

The burst of reprogramming technology in recent years has revolutionized the field of stem cell biology, offering new opportunities for personalized, regenerative therapies. The direct reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) has provided an invaluable tool to study and model a wide range of human diseases. Here, we review the transforming potential of such a strategy in research and in therapies applicable to the hematology field

Mismatch Negativity and P3a Impairment through Different Phases of Schizophrenia and Their Association with Real-Life Functioning

Impairment in functioning since the onset of psychosis and further deterioration over time is a key aspect of subjects with schizophrenia (SCZ). Mismatch negativity (MMN) and P3a, indices of early attention processing that are often impaired in schizophrenia, might represent optimal electrophysiological candidate biomarkers of illness progression and poor outcome. However, contrasting findings are reported about the relationships between MMN-P3a and functioning. The study aimed to investigate in SCZ the influence of illness duration on MMN-P3a and the relationship of MMN-P3a with functioning. Pitch (p) and duration (d) MMN-P3a were investigated in 117 SCZ and 61 healthy controls (HCs). SCZ were divided into four illness duration groups: ≤ 5, 6 to 13, 14 to 18, and 19 to 32 years. p-MMN and d-MMN amplitude was reduced in SCZ compared to HCs, independently from illness duration, psychopathology, and neurocognitive deficits. p-MMN reduction was associated with lower “Work skills”. The p-P3a amplitude was reduced in the SCZ group with longest illness duration compared to HCs. No relationship between P3a and functioning was found. Our results suggested that MMN amplitude reduction might represent a biomarker of poor functioning in SCZ

Minimal residual disease negativity by next-generation flow cytometry is associated with improved organ response in AL amyloidosis

© The Author(s) 2021.Light chain (AL) amyloidosis is caused by a small B-cell clone producing light chains that form amyloid deposits and cause organ dysfunction. Chemotherapy aims at suppressing the production of the toxic light chain (LC) and restore organ function. However, even complete hematologic response (CR), defined as negative serum and urine immunofixation and normalized free LC ratio, does not always translate into organ response. Next-generation flow (NGF) cytometry is used to detect minimal residual disease (MRD) in multiple myeloma. We evaluated MRD by NGF in 92 AL amyloidosis patients in CR. Fifty-four percent had persistent MRD (median 0.03% abnormal plasma cells). There were no differences in baseline clinical variables in patients with or without detectable MRD. Undetectable MRD was associated with higher rates of renal (90% vs 62%, p = 0.006) and cardiac response (95% vs 75%, p = 0.023). Hematologic progression was more frequent in MRD positive (0 vs 25% at 1 year, p = 0.001). Altogether, NGF can detect MRD in approximately half the AL amyloidosis patients in CR, and persistent MRD can explain persistent organ dysfunction. Thus, this study supports testing MRD in CR patients, especially if not accompanied by organ response. In case MRD persists, further treatment could be considered, carefully balancing residual organ damage, patient frailty, and possible toxicity.This study was supported by a grant from CARIPLO “Molecular mechanisms of Ig toxicity in age-related plasma cell dyscrasias no. 2015-0591”, by a grant from the Black Swan Research Initiative from the International Myeloma Foundation “Automated multidimensional flow cytometry for high-sensitive screening and to monitor response in AL amyloidosis”, by a grant from CARIPLO “Structure–function relation of amyloid: understanding the molecular bases of protein misfolding diseases to design new treatments no. 2013-0964”, by a grant from the Amyloidosis Foundation “Investigating new therapies to treat AL amyloidosis”, and by a grant from Cancer Research UK, FCAECC and AIRC under the Accelerator Award 2017 Program “Early detection and intervention: understanding the mechanisms of transformation and hidden resistance of incurable hematological malignancies”, by a grant from CARIPLO “Harnessing the plasma cell secretory capacity against systemic light chain amyloidosis” (no. 2018-0257), by a grant from the Italian Ministry of Health “Towards effective, patient-tailored anti-plasma cell therapies in AL amyloidosis: predicting drug response and overcoming drug resistance” (GR-2018-12368387). This study has also supported the Centro de Investigación Biomédica en Red—Área de Oncología—del Instituto de Salud Carlos III (CIBERONC; CB16/12/00369, CB16/12/00400, and CB16/12/00489) and the Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS No. PI13/02196). G.P. is supported in part by the Bart Barlogie Young Investigator Award from the International Myeloma Society (IMS). P.M. is supported in part by a fellowship grant form Collegio Ghislieri (Pavia). We acknowledge the study coordinator and data manager Anna Carnevale Baraglia

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

Application of Induced Pluripotent Stem Cell Technology to the Study of Hematological Diseases

The burst of reprogramming technology in recent years has revolutionized the field of stem cell biology, offering new opportunities for personalized, regenerative therapies. The direct reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) has provided an invaluable tool to study and model a wide range of human diseases. Here, we review the transforming potential of such a strategy in research and in therapies applicable to the hematology field

Hypertension induces compensatory arterial remodeling following arteriotomy

Background. Hypertension has been traditionally considered a risk factor for restenosis following carotid arteriotomy. Genetic and morphological response to carotid arteriotomy in normotensive Wystar-Kyoto (WKY), spontaneously hypertensive (SHR), and Milan hypertensive (MHS) rats were analyzed.Material and Methods. C-myc, angiotensin II receptor-1 (AT1), angiotensin II receptor-2 (AT2), endothelin-1 receptor A (ETA), endothelin-1 receptor B (ETB), Bcl-2 family-members (Bcl-2/Bax, Bcl-X-L/S) were analyzed in surgically injured as well as uninjured carotids of WKY and hypertensive strains (HS). Thirty-day histology and morphometry were accomplished on injured and uninjured carotids.Results. C-myc mRNA is activated earlier and/or to a greater extent in hypertensive strains than in WKY. AT1 mRNA increases in WKY after injury, while it decreases in SHR and MHS. AT2 shows the opposite, decreasing in WKY and increasing in hypertensive strains. ETA mRNA decreases in all strains although with different timing and levels, associated with a replacement by ETB mRNA. Bcl-2/Bax ratio gradually decreases in WKY, while it shows only a transient decrease in SHR and MHS 4 h after the injury. Negative remodeling is observed in all injured carotids, although neointima was detected in WKY only. Thirty days following arteriotomy, morphometry demonstrated a significant decrease of luminal area, with consistent gain in the medial area in WKY, whereas hypertensive strains showed significant increase of the luminal area, consistent with a contemporary decrease of the medial area.Conclusions. Vaso-relaxant AT2 and ETB induced limited vasoconstriction in HS. Less apoptosis in hypertensive rats reduced cell proliferation, contrasting c-myc. These responses favorably modulated media/ lumen area ratio following arteriotomy in HS. (c) 2007 Elsevier Inc. All rights reserved

Injury to rat carotid arteries causes time-dependent changes in gene expression in contralateral uninjured arteries

Vascular surgery aimed at stenosis removal induces local reactions often leading to restenosis. Although extensive analysis has been focused on pathways activated in injured arteries, little attention has been devoted to associated systemic vascular reactions. The aim of the present study was to analyse changes occurring in contralateral uninjured rat carotid arteries in the acute phase following unilateral injury. WKY (Wistar-Kyoto) rats were subjected to unilateral carotid arteriotomy. Contralateral uninjured carotid arteries were harvested from 4 h to 7 days after injury. Carotid arteries were also harvested from sham-operated rats and uninjured rats. Carotid morphology and morphometry were examined. Affymetrix microarrays were used for differential analysis of gene expression. A subset of data was validated by real-time RT-PCR (reverse transcription-PCR) and verified at the protein level by Western blotting. A total of 1011 genes were differentially regulated in contralateral uninjured carotid arteries from 4 h to 7 days after arteriotomy (P = 2) and were classified into 19 gene ontology functional categories. To a lesser extent, mRNA variations also occurred in carotid arteries of sham-operated rats. Among the changes, up-regulation of members of the RAS (renin-angiotensin system) was detected, with possible implications for vasocompensative mechanisms induced by arteriotomy. In particular, a selective increase in the 69 kDa isoform of the N-domain of ACE (angiotensin-converting enzyme), and not the classical somatic 195 kDa isoform, was observed in contralateral uninjured carotid arteries, suggesting that this 69 kDa isoenzyme could influence local Angll (angiotensin II) production. In conclusion, systemic reactions to injury occur in the vasculature, with potential clinical relevance, and suggest that caution is needed in the choice of controls during experimental design in vivo

Expression profiles in surgically induced carotid stenosis: A combined transcriptomic and proteomic investigation

Vascular injury aimed at stenosis removal induces local reactions often leading to restenosis. The aim of this study was a concerted transcriptomic-proteomics analysis of molecular variations in a model of rat carotid arteriotomy, to dissect the molecular pathways triggered by vascular surgical injury and to identify new potential anti-restenosis targets. RNA and proteins extracted from inbred Wistar Kyoro (WKY) rat carotids harvested 4 hrs, 48 hrs and 7 days after arteriotomy were analysed by Affymetrix rat microarrays and by bidimensional electrophoresis followed by liquid chromatography and tandem mass spectrometry, using as reference the RNA and the proteins extracted from uninjured rat carotids. Results were classified according to their biological function, and the most significant Kyoro Encyclopedia of Genes and Genomes (KEGG) pathways were identified. A total of 1163 mRNAs were differentially regulated in arteriotomy-injured carotids 4 hrs, 48 hrs and 7 days after injury (P < 0.0001, fold-change ≥2), while 48 spots exhibited significant changes after carotid arteriotomy (P < 0.05, fold-change ≥2). Among them, 16 spots were successfully identified and resulted to correspond to a set of 19 proteins. mRNAs were mainly involved in signal transduction, oxidative stress/ inflammation and remodelling, including many new potential targets for limitation of surgically induced (re)stenosis (e.g. Arginase I, Kruppel like factors). Proteome analysis confirmed and extended the microrarray data, revealing time-dependent post-translational modifications of Hsp27, haptoglobin and contrapsin-like protease inhibitor 6, and the differential expression of proteins mainly involved in contractility. Transcriptomic and proteomic methods revealed functional categories with different preferences, related to the experimental sensitivity and to mechanisms of regulation. The comparative analysis revealed correlation between transcriptional and translational expression for 47% of identified proteins. Exceptions from this correlation confirm the complementarities of these approaches