Upregulation of miR-34a-5p,miR-20a-3p and miR-29a-3p by Onconase in A375 Melanoma Cells Correlates with the Downregulation of Specific Onco-Proteins

Onconase (ONC) is an amphibian secretory ribonuclease displaying cytostatic and cytotoxic activities against many mammalian tumors, including melanoma. ONC principally damages tRNA species, but also other non-coding RNAs, although its precise targets are not known. We investigated the ONC ability to modulate the expression of 16 onco-suppressor microRNAs (miRNAs) in the A375 BRAF-mutated melanoma cell line. RT-PCR and immunoblots were used to measure the expression levels of miRNAs and their regulated proteins, respectively. In silico study was carried out to verify the relations between miRNAs and their mRNA targets. A375 cell transfection with miR-20a-3p and miR-34a-5p mimics or inhibitors was performed. The onco-suppressors miR-20a-3p, miR-29a-3p and miR-34a-5p were highly expressed in 48-h ONC-treated A375 cells. The cytostatic effect of ONC in A375 cells was mechanistically explained by the sharp inhibition of cyclins D1 and A2 expression level, as well as by downregulation of retinoblastoma protein and cyclin-dependent-kinase-2 activities. Remarkably, the expression of kinases ERK1/2 and Akt, as well as of the hypoxia inducible factor-1α, was inhibited by ONC. All these proteins control pro-survival pathways. Finally, many crucial proteins involved in migration, invasion and metastatic potential were downregulated by ONC. Results obtained from transfection of miR-20a-3p and miR-34a-5p inhibitors in the presence of ONC show that these miRNAs may participate in the antitumor effects of ONC in the A375 cell line. In conclusion, we identified many intracellular downregulated proteins involved in melanoma cell proliferation, metabolism and progression. All mRNAs coding these proteins may be targets of miR-20a-3p, miR-29a-3p and/or miR-34a-5p, which are in turn upregulated by ONC. Data suggest that several known ONC anti-proliferative and anti-metastatic activities in A375 melanoma cells might depend on the upregulation of onco-suppressor miRNAs. Notably, miRNAs stability depends on the upstream regulation by long-non-coding-RNAs or circular-RNAs that can, in turn, be damaged by ONC ribonucleolytic activity.     

The Protective Role of Prolyl Oligopeptidase (POP) Inhibition in Kidney Injury Induced by Renal Ischemia–Reperfusion

Ischemia/reperfusion injury (IRI) is a complex pathophysiological process characterized by blood circulation disorder caused by various factors, such as traumatic shock, surgery, organ transplantation, and thrombus. Severe metabolic dysregulation and tissue structure destruction are observed upon restoration of blood flow to the ischemic tissue. The kidney is a highly perfused organ, sensitive to ischemia and reperfusion injury, and the incidence of renal IRI has high morbidity and mortality. Several studies showed that infiltration of inflammatory cells, apoptosis, and angiogenesis are important mechanisms involved in renal IRI. Despite advances in research, effective therapies for renal IRI are lacking. Recently it has been demonstrated the role of KYP2047, a selective inhibitor of prolyl oligopeptidase (POP), in the regulation of inflammation, apoptosis, and angiogenesis. Thus, this research focused on the role of POP in kidney ischemia/reperfusion (KI/R). An in vivo model of KI/R was performed and mice were subjected to KYP2047 treatment (intraperitoneal, 0.5, 1 and 5 mg/kg). Histological analysis, Masson’s trichrome and periodic acid shift (PAS) staining, immunohistochemical and Western blots analysis, real-time PCR (RT-PCR) and ELISA were performed on kidney samples. Moreover, serum creatinine and blood urea nitrogen (BUN) were quantified. POP-inhibition by KYP2047 treatment, only at the doses of 1 and 5 mg/kg, significantly reduced renal injury and collagen amount, regulated inflammation through canonical and non-canonical NF-κB pathway, and restored renal function. Moreover, KYP2047 modulated angiogenesis markers, such as TGF-β and VEGF, also slowing down apoptosis. Interestingly, treatment with KYP2047 modulated PP2A activity. Thus, these findings clarified the role of POP inhibition in AKI, also offering novel therapeutic target for renal injury after KI/R.     

Identifying and correcting invalid citations due to DOI errors in Crossref data

This work aims to identify classes of DOI mistakes by analysing the open bibliographic metadata available in Crossref, highlighting which publishers were responsible for such mistakes and how many of these incorrect DOIs could be corrected through automatic processes. By using a list of invalid cited DOIs gathered by OpenCitations while processing the OpenCitations Index of Crossref open DOI-to-DOI citations (COCI) in the past two years, we retrieved the citations in the January 2021 Crossref dump to such invalid DOIs. We processed these citations by keeping track of their validity and the publishers responsible for uploading the related citation data in Crossref. Finally, we identified patterns of factual errors in the invalid DOIs and the regular expressions needed to catch and correct them. The outcomes of this research show that only a few publishers were responsible for and/or affected by the majority of invalid citations. We extended the taxonomy of DOI name errors proposed in past studies and defined more elaborated regular expressions that can clean a higher number of mistakes in invalid DOIs than prior approaches. The data gathered in our study can enable investigating possible reasons for DOI mistakes from a qualitative point of view, helping publishers identify the problems underlying their production of invalid citation data. Also, the DOI cleaning mechanism we present could be integrated into the existing process (e.g. in COCI) to add citations by automatically correcting a wrong DOI. This study was run strictly following Open Science principles, and, as such, our research outcomes are fully reproducible.

     

Performance of cascade cycles working with blends of CO2 + natural refrigerants

In this paper, an analysis on the performance of a cascade refrigeration cycle operated with blends of carbon dioxide (or R744) plus hydrocarbons (ethane or R170, propane or R290, ethylene or R1150, propylene or R1270) and dimethyl ether (or RE170) as the low-temperature working fluid was carried out. The properties of the investigated blends were used to simulate the behaviour of a cascade cycle using ammonia (or R717) as the high-temperature-circuit working fluid.The aim of this work was to study the possibility of using carbon dioxide mixtures in those applications where temperatures below its triple point (216.59 K) are needed. The analysis was carried out by developing a software based on the Carnahan-Starling-DeSantis (CSD) Equation of State (EoS) using binary interaction parameters derived from the experimental data in the literature.Results show that adding R744 to HCs and dimethyl ether reduces the cycle performance, even if acceptable values are always achieved for the COP. Main attractive of the R744 + natural refrigerant blends is connected with their GWP, ODP and flammability properties lower than those of pure fluids.     

Near-surface processing on AlGaN/GaN heterostructures: a nanoscale electrical and structural characterization

The effects of near-surface processing on the properties of AlGaN/GaN heterostructures were studied, combining conventional electrical characterization on high-electron mobility transistors (HEMTs), with advanced characterization techniques with nanometer scale resolution, i.e., transmission electron microscopy, atomic force microscopy (AFM) and conductive atomic force microscopy (C-AFM). In particular, a CHF₃-based plasma process in the gate region resulted in a shift of the threshold voltage in HEMT devices towards less negative values. Two-dimensional current maps acquired by C-AFM on the sample surface allowed us to monitor the local electrical modifications induced by the plasma fluorine incorporated in the material.     

Kinetics of Si and Ge nanowires growth through electron beam evaporation

Si and Ge have the same crystalline structure, and although Si-Au and Ge-Au binary alloys are thermodynamically similar (same phase diagram, with the eutectic temperature of about 360°C), in this study, it is proved that Si and Ge nanowires (NWs) growth by electron beam evaporation occurs in very different temperature ranges and fluence regimes. In particular, it is demonstrated that Ge growth occurs just above the eutectic temperature, while Si NWs growth occurs at temperature higher than the eutectic temperature, at about 450°C. Moreover, Si NWs growth requires a higher evaporated fluence before the NWs become to be visible. These differences arise in the different kinetics behaviors of these systems. The authors investigate the microscopic growth mechanisms elucidating the contribution of the adatoms diffusion as a function of the evaporated atoms direct impingement, demonstrating that adatoms play a key role in physical vapor deposition (PVD) NWs growth. The concept of incubation fluence, which is necessary for an interpretation of NWs growth in PVD growth conditions, is highlighted.