Alexios Aletras

Prof. Alexios Aletras


Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 December 2019 in Materials
Verified
Journal Article
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ITIoanna Tzoumani
Ioanna Tzoumani
Georgia LainiotiGeorgia Lainioti
Georgia Lainioti
AAAlexios Aletras
Alexios Aletras
GZGabriel Zainescu
Gabriel Zainescu
Daniela Simina StefanDaniela Simina Stefan
Daniela Simina Stefan
Joannis KallitsisJoannis Kallitsis
Joannis Kallitsis
Novel cross-linked hydrogels were synthesized as potential materials for the development of smart biofertilizers. For this purpose, hydrogels were prepared using collagen hydrolysate recovered from tannery waste. The water-soluble polymer poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate) (P(SSNa-co-GMAx)) was among others used for the cross-linking reaction that combined hydrophilic nature with epoxide groups. The synthetic procedure was thoroughly investigated in order to ensure high percentage of epoxide groups in combination with water-soluble behavior. The copolymer did not show cytotoxicity against normal lung, skin fibroblasts, or nasal polyps fibroblasts. Through the present work, we also present the ability to control the properties of cross-linked hydrogels by altering copolymer’s composition and cross-linking parameters (curing temperature and time). Hydrogels were then studied in terms of water-uptake capacity for a period up to six days. The techniques Proton Nuclear Magnetic Resonance (1H NMR), Thermogravimetric Analysis (TGA), Size Exclusion Chromatography (SEC), and Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) were applied for the characterization of the synthesized copolymers and the cross-linked hydrogels. Three samples of biofertilizers based on collagen hydrolysate functionalized with P(SSNa-co-GMAx) and starch and having nutrients encapsulated (N, P, K) were prepared and characterized by physical–chemical analysis and Energy Dispersive X-ray analysis-Scanning Electron Microscope (EDAX-SEM) in terms of microstructure. Preliminary tests for application as fertilizers were performed including the release degree of oxidable organic compounds.

24 April 2009 in JBIC Journal of Biological Inorganic Chemistry
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MPMaria Pavlaki
Maria Pavlaki
KDKaterina Debeli
Katerina Debeli
ITIrene-Eva Triantaphyllidou
Irene-Eva Triantaphyllidou
NKNikolaos Klouras
Nikolaos Klouras
EGEleftheria Giannopoulou
Eleftheria Giannopoulou
AAAlexios Aletras
Alexios Aletras

Verified
Journal Article
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MCMaria Christopoulou
Maria Christopoulou
AAAlexios Aletras
Alexios Aletras
EPEleni Papakonstantinou
Eleni Papakonstantinou
DSDaiana Stolz
Daiana Stolz
Spyros SkandalisSpyros Skandalis
Spyros Skandalis
Recent advancements highlight the intricate interplay between the extracellular matrix (ECM) and immune responses, notably in respiratory diseases such as asthma and Chronic Obstructive Pulmonary Disease (COPD). The ECM, a dynamic structural framework within tissues, orches-trates a plethora of cellular processes, including immune cell behavior and tissue repair mecha-nisms. WNT1-inducible-signaling pathway protein 1 (WISP1), a key ECM regulator, controls immune cell behavior, cytokine production, and tissue repair by modulating integrins, PI3K, Akt, β-catenin, and mTOR signaling pathways. WISP1 also induces macrophage migration inhibitory factor (MIF) expression via Src kinases and epidermal growth factor receptor (EGFR) activation. MIF, through its wide range of activities, enhances inflammation and tissue restructuring. Rec-ognized for its versatile roles in regulating the immune system, MIF interacts with multiple immune components, such as the NLRP3 inflammasome, thereby sustaining inflammatory pro-cesses. The WISP1–MIF axis potentially unveils complex molecular mechanisms governing im-mune responses and inflammation. Understanding the intricate roles of WISP1 and MIF in the pathogenesis of chronic respiratory diseases such as asthma and COPD could lead to the identi-fication of novel targets for therapeutic intervention to alleviate disease severity and enhance patient outcomes.

1 August 2012 in Current Molecular Medicine
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Spyros SkandalisSpyros Skandalis
Spyros Skandalis
AAAlexios Aletras
Alexios Aletras
CGChrysostomi Gialeli
Chrysostomi Gialeli
ATAchilleas D. Theocharis
Achilleas D. Theocharis
Nikolaos A. AfratisNikolaos A. Afratis
Nikolaos A. Afratis
Nikos KaramanosNikos Karamanos
Nikos Karamanos
Extracellular matrices (ECMs) are dynamic structures that provide cells not only with a structural support but, importantly, exhibit significant functional roles in the control of key cellular events such as adhesion, migration, proliferation, differentiation, and survival. In tumors, matrix effectors such as proteoglycans (PGs) and matrix metalloproteinases (MMPs) constitute major regulators of the interactions between tumor cells and their microenvironment and, therefore, they have been identified as potential molecular targets that are expected to advance the pharmacological treatment of cancer. ECMs composition is highly affected by cells through intrinsic regulatory mechanisms, such as the ubiquitin-proteasome system (UPS). Proteasome is a major cellular protease complex that controls the concentration and turnover of molecules in ECMs, including certain types of PGs, MMPs and collagens, and consequently, in the tumor microenvironment. Furthermore, proteasome activity is regulated by PG-derived intracellular glycosaminoglycan moieties revealing a critical inter-dependence of these compounds. Since ECMs renewal and degradation can be tightly regulated by proteasome activities, its modulation may be considered as a novel strategy to control the properties of tumor microenvironment. Currently, there are several proteasome inhibitors targeting distinct molecular pathways either approved or in clinical trials for the treatment of multiple cancers. In this review, the novel approach of targeting the proteasome to selectively regulate the synthesis and the bioactivity of certain matrix PGs and MMPs is presented and discussed.

18 December 2018 in BMC Ophthalmology
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Journal Article
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AAAlexios Aletras
Alexios Aletras
ITIoannis Trilivas
Ioannis Trilivas
MCMaria-Elpida Christopoulou
Maria-Elpida Christopoulou
SDSotiria Drakouli
Sotiria Drakouli
CGConstantine D Georgakopoulos
Constantine D Georgakopoulos
NPNikolaos Pharmakakis
Nikolaos Pharmakakis
Pterygium is a condition characterized by epithelial overgrowth of the cornea, inflammatory cell infiltration and an abnormal extracellular matrix accumulation. Chronic UV exposure is considered as a pathogenic factor of this disease. Proteasome is an intracellular multi-subunit protease complex that degrades intracellular proteins. Among proteasome subunits the β5 (PSMB5), bearing chymotrypsin-like activity. It is considered as the main proteasome subunit and its expression is mediated by Nrf2-ARE pathway in many cell types. This study investigates the expression of PSMB5 in pterygium and the effect of UVB irradiation on its expression and activity in pterygium fibroblasts. Normal conjunctival and pterygium specimens were obtained from the bulbar conjunctiva of patients undergoing cataract surgery and from patients with pterygium undergoing surgical removal of primary tissue, respectively. Fibroblasts were isolated upon treatment of specimens with clostridium collagenase. The expression of PSMB5 and Nrf2 in tissues and cells was ascertained by RT-PCR analysis and western blotting. Cell survival was measured by the MTT method and the proteasome chymotrypsin-like activity was determined by fluorometry. RT-PCR analysis showed that the expression of PSMB5 was significantly lower in pterygium than in normal conjunctiva. The expression of PSMB5 was mediated by the Nrf2/ARE pathway as indicated by using the Nrf2 activator Oltipraz. The expression of PSMB5 and Nrf2 by pterygium fibroblasts was suppressed in a dose dependent manner following UVB radiation of 0–50 mJ/cm2 doses. The expression of PSMB5, but not of Nrf2, remained at almost the control levels, when UVB exposure was performed after pre-incubation of cells with the src kinases inhibitor PP2. UVB irradiation had very low deleterious effect on fibroblasts survival, while it did not affect the proteasome chymotrypsin-like activity. In pterygium fibroblasts, UVB exposure leads to down-regulation of Nrf2/ARE-mediated PSMB5 gene expression, in which src kinases may be implicated. This effect may be partially responsible for the lower expression of PSMB5 detected in pterygium as compared to normal conjunctiva.

1 March 2024 in American Journal of Physiology-Cell Physiology
Verified
Journal Article
Open access
MCMaria Christopoulou
Maria Christopoulou
Spyros SkandalisSpyros Skandalis
Spyros Skandalis
EPEleni Papakonstantinou
Eleni Papakonstantinou
DSDaiana Stolz
Daiana Stolz
AAAlexios Aletras
Alexios Aletras
The present study demonstrates for the first time that Wnt1-inducible signaling protein 1 (WISP1) regulates migration inhibitory factor (MIF) expression and activity and identifies the main signaling pathways involved. The newly discovered WISP1-MIF axis may drive lung inflammation and could result in the design of novel targeted therapies in inflammatory lung diseases.