Low Cell Bioenergetic Metabolism Characterizes Chronic Lymphocytic Leukemia Patients with Unfavorable Genetic Factors and with a Better Response to BTK Inhibition.

Chronic Lymphocytic Leukemia (CLL) is an indolent malignancy characterized by the accumulation of quiescent mature B cells. However, these cells are transcriptionally and translationally active, implicating an active metabolism. The recent literature suggests that CLL cells have an oxidative-type phenotype. Given the role of cell metabolism, which is able to influence the outcome of treatments, in other neoplasms, we aimed to assess its prognostic role in CLL patients by determining the ex vivo bioenergetic metabolic profile of CLL cells, evaluating the correlation with the patient clinical/biological characteristics and the in vivo response to BTK inhibitor treatment. Clustering analysis of primary samples identified two groups, characterized by low (CLL low) or high (CLL high) bioenergetic metabolic rates. Compared to the CLL high, CLL with lower bioenergetic metabolic rates belonged to patients characterized by a statistically significant higher white blood cell count and by unfavorable molecular genetics. More importantly, patients in the CLL low cluster displayed a better and more durable response to the BTK inhibitor ibrutinib, thus defining a bioenergetic metabolic subgroup that can benefit the most from this therapy.

Doxorubicin-Induced Cardiac Senescence Is Alleviated Following Treatment with Combined Polyphenols and Micronutrients through Enhancement in Mitophagy.

Oxidative stress and impaired mitophagy are the hallmarks of cardiomyocyte senescence. Specifically, a decrease in mitophagic flux leads to the accumulation of damaged mitochondria and the development of senescence through increased ROS and other mediators. In this study, we describe the preventive role of A5+, a mix of polyphenols and other micronutrients, in doxorubicin (DOXO)-induced senescence of H9C2 cells. Specifically, H9C2 cells exposed to DOXO showed an increase in the protein expression proteins of senescence-associated genes, p21 and p16, and a decrease in the telomere binding factors TRF1 and TRF2, indicative of senescence induction. Nevertheless, A5+ pre-treatment attenuated the senescent-like cell phenotype, as evidenced by inhibition of all senescent markers and a decrease in SA-ß-gal staining in DOXO-treated H9C2 cells. Importantly, A5+ restored the LC3 II/LC3 I ratio, Parkin and BNIP3 expression, therefore rescuing mitophagy, and decreased ROS production. Further, A5+ pre-treatment determined a ripolarization of the mitochondrial membrane and improved basal respiration. A5+-mediated protective effects might be related to its ability to activate mitochondrial SIRT3 in synergy with other micronutrients, but in contrast with SIRT4 activation. Accordingly, SIRT4 knockdown in H9C2 cells further increased MnSOD activity, enhanced mitophagy, and reduced ROS generation following A5+ pre-treatment and DOXO exposure compared to WT cells. Indeed, we demonstrated that A5+ protects H9C2 cells from DOXO-induced senescence, establishing a new specific role for A5+ in controlling mitochondrial quality control by restoring SIRT3 activity and mitophagy, which provided a molecular basis for the development of therapeutic strategies against cardiomyocyte senescence.

YY1 Knockdown Relieves the Differentiation Block and Restores Apoptosis in AML Cells.

In this study we analyzed the expression of Yin and Yang 1 protein (YY1), a member of the noncanonical PcG complexes, in AML patient samples and AML cell lines and the effect of YY1 downregulation on the AML differentiation block. Our results show that YY1 is significantly overexpressed in AML patient samples and AML cell lines and that YY1 knockdown relieves the differentiation block. YY1 downregulation in two AML cell lines (HL-60 and OCI-AML3) and one AML patient sample restored the expression of members of the CEBP protein family, increased the expression of extrinsic growth factors/receptors and surface antigenic markers, induced morphological cell characteristics typical of myeloid differentiation, and sensitized cells to retinoic acid treatment and to apoptosis. Overall, our data show that YY1 is not a secondary regulator of myeloid differentiation but that, if overexpressed, it can play a predominant role in myeloid differentiation block.

Fused Deposition Modelling of Polymeric Auxetic Structures: A Review.

Additive Manufacturing (AM) techniques have recently attracted the attention of scientists for the development of prototypes with complex or particular geometry in a fast and cheap way. Among the different AM processes, the Fused Deposition Modelling process (FDM) offers several advantages in terms of costs, implementation features and design freedom. Recently, it has been adopted to realise auxetic structures, which are characterised by negative Poisson ratio, enhanced mechanical properties, and a higher compression resistance than conventional structures. This review outlines the use of AM processes, in particular FDM, to design and obtain auxetic structures, with the final aim to exploit their applications in different fields. The first part of this work presents a brief classification of auxetic structures and materials. Subsequently, a summary of additive manufacturing processes is presented, focusing on the use of FDM and its limitations. Finally, the studies on the use of additive manufacturing to produce auxetic structures are shown, evidencing the potential of the concurrent combination of a fast prototyping technique such as FDM and the characteristics of polymer- and/or composite-based auxetic structures. Indeed, this new technological field opens the possibility of realising novel structures with integrated smart behaviour, multifunctional properties, compression resistance, and a tailored microstructure and shape.

Effect of Fibre Orientation on Novel Continuous 3D-Printed Fibre-Reinforced Composites.

Among the several additive manufacturing techniques, fused filament fabrication (FFF) is a 3D printing technique that is fast, handy, and low cost, used to produce complex-shaped parts easily and quickly. FFF adds material layer by layer, saving energy, costs, raw material costs, and waste. Nevertheless, the mechanical properties of the thermoplastic materials involved are low compared to traditional engineering materials. This paper deals with the manufacturing of composite material laminates obtained by the Markforged continuous filament fabrication (CFF) technique, using an innovative matrix infilled by carbon nanofibre (Onyx), a high-strength thermoplastic material with an excellent surface finish and high resistance to chemical agents. Three macro-categories of samples were manufactured using Onyx and continuous carbon fibre to evaluate the effect of the fibre on mechanical features of the novel composites and their influence on surface finishes. SEM (Scanning Electron Microscopy) analysis and acquisition of roughness profile by a confocal lens were conducted. Tensile and compression tests, thermogravimetric analysis and calorimetric analysis using a DSC (differential scanning calorimeter) were carried out on all specimen types to evaluate the influence of the process parameters and layup configurations on the quality and mechanical behaviour of the 3D-printed samples.

SIRT5 Inhibition Induces Brown Fat-Like Phenotype in 3T3-L1 Preadipocytes.

Brown adipose tissue (BAT) activity plays a key role in regulating systemic energy. The activation of BAT results in increased energy expenditure, making this tissue an attractive pharmacological target for therapies against obesity and type 2 diabetes. Sirtuin 5 (SIRT5) affects BAT function by regulating adipogenic transcription factor expression and mitochondrial respiration. We analyzed the expression of SIRT5 in the different adipose depots of mice. We treated 3T3-L1 preadipocytes and mouse primary preadipocyte cultures with the SIRT5 inhibitor MC3482 and investigated the effects of this compound on adipose differentiation and function. The administration of MC3482 during the early stages of differentiation promoted the expression of brown adipocyte and mitochondrial biogenesis markers. Upon treatment with MC3482, 3T3-L1 adipocytes showed an increased activation of the AMP-activated protein kinase (AMPK), which is known to stimulate brown adipocyte differentiation. This effect was paralleled by an increase in autophagic/mitophagic flux and a reduction in lipid droplet size, mediated by a higher lipolytic rate. Of note, MC3482 increased the expression and the activity of adipose triglyceride lipase, without modulating hormone-sensitive lipase. Our findings reveal that SIRT5 inhibition stimulates brown adipogenesis in vitro, supporting this approach as a strategy to stimulate BAT and counteract obesity.

Corrigendum: Metabolic Reprogramming Promotes Myogenesis During Aging.

[This corrects the article DOI: 10.3389/fphys.2019.00897.].

Effect of Plasma Treatment on the Impact Behavior of Epoxy/Basalt Fiber-Reinforced Composites: A Preliminary Study.

Hydrophobic surfaces are highly desired for several applications due to their exceptional properties such as self-cleaning, anti-icing, anti-friction and others. Such surfaces can be prepared via numerous methods including plasma technology, a dry technique with low environmental impact. In this paper, the effect of a one-step sulfur hexafluoride (SF6) plasma treatment upon the low velocity impact behavior of basalt/epoxy composites has been investigated by using several characterization techniques. A capacitive coupled radiofrequency plasma system was used for the plasma surface treatment of basalt/epoxy composites, and suitable surface treatment conditions were experimentally investigated with respect to gas flow rate, chamber pressure, power intensity, and surface treatment time by measuring the water droplet contact angle of treated specimens. The contact angle measurements showed that treating with SF6 plasma would increase the hydrophobicity of basalt/epoxy composites; moreover, the impact results obtained on reinforced epoxy basalt fiber showed damage in a confined area and higher impact resistance for plasma-treated basalt systems.

Che-1/AATF-induced transcriptionally active chromatin promotes cell proliferation in multiple myeloma.

Multiple myeloma (MM) is a hematologic malignancy produced by a clonal expansion of plasma cells and characterized by abnormal production and secretion of monoclonal antibodies. This pathology exhibits an enormous heterogeneity resulting not only from genetic alterations but also from several epigenetic dysregulations. Here we provide evidence that Che-1/AATF (Che-1), an interactor of RNA polymerase II, promotes MM proliferation by affecting chromatin structure and sustaining global gene expression. We found that Che-1 depletion leads to a reduction of "active chromatin" by inducing a global decrease of histone acetylation. In this context, Che-1 directly interacts with histones and displaces histone deacetylase class I members from them. Strikingly, transgenic mice expressing human Che-1 in plasma cells develop MM with clinical features resembling those observed in the human disease. Finally, Che-1 downregulation decreases BRD4 chromatin accumulation to further sensitize MM cells to bromodomain and external domain inhibitors. These findings identify Che-1 as a promising target for MM therapy, alone or in combination with bromodomain and external domain inhibitors.

Bone Marrow Stromal Cell-Derived IL-8 Upregulates PVR Expression on Multiple Myeloma Cells via NF-kB Transcription Factor.

Bone marrow stromal cells (BMSCs) strongly contribute to multiple myeloma (MM) progression, promoting the survival and growth of malignant plasma cells (PCs). However, the possible impact of these cells on the immune-mediated recognition of MM cells remains largely unknown. DNAM-1 activating receptor plays a prominent role in NK cell anti-MM response engaging the ligands poliovirus receptor (PVR) and nectin-2 on malignant PCs. Here, we analysed the role of MM patient-derived BMSCs in the regulation of PVR expression. We found that BMSCs enhance PVR surface expression on MM cells and promote their NK cell-mediated recognition. PVR upregulation occurs at transcriptional level and involves NF-kB transcription factor activation by BMSC-derived soluble factors. Indeed, overexpression of a dominant-negative mutant of IKBα blocked PVR upregulation. IL-8 plays a prominent role in these mechanisms since blockade of CXCR1/2 receptors as well as depletion of the cytokine via RNA interference prevents the enhancement of PVR expression by BMSC-derived conditioned medium. Interestingly, IL-8 is associated with stromal microvesicles which are also required for PVR upregulation via CXCR1/CXCR2 signaling activation. Our findings identify BMSCs as regulators of NK cell anti-MM response and contribute to define novel molecular pathways involved in the regulation of PVR expression in cancer cells.