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The authors regret for a mistake regarding the authors’ contribution. We would like to add Mr Christos Chamilos as an equally contributing first author to this work. The authors would like to apologise for any inconvenience caused. © 2021 Elsevier B.V.

In this study, a series of novel substituted pyrazolo[3,4-c]pyridin-5-ylamidines was synthesized and their cytotoxicity against three cancer cell lines (MDA-MB-231, HT-1080, PC-3), as well as a human normal cell line (AG01523) was evaluated. A number of derivatives could strongly reduce cancer cells proliferation and exhibit apoptotic induction capability, while reasonable structure-activity relationships could be extracted. Certain analogues were endowed with low toxicity against normal cells. Cell cycle analysis revealed that most of the active compounds induced a G0/G1 arrest of HT-1080 cells. Moreover, the potential mechanisms of the cytotoxic activity of the promising compounds were investigated in HT-1080 cells, upon study of their effects on the phosphorylation of Akt, ERK and p38 MAPK. Most of the active derivatives inhibit phosphorylation of Akt and ERK and/or induce p38 MAPK phosphorylation, providing a potential indication on the mode of action of this class. © 2021 Elsevier Masson SAS

Micro-nanostructured surfaces play a key role in the understanding of cell-surface interactions. The aim of this work was to study the effect of oxygen plasma micro-nanostructured commercial PMMA plates on the adhesion, morphology and proliferation of normal skin fibroblasts and A431 skin cancer cells. It was found that the adhesion and proliferation of normal skin fibroblasts was significantly inhibited, while their morphology and focal points formation were seriously impaired on plasma treated surfaces with peak-to-valley height ≥ 5 μm as compared to the untreated ones. On the other hand, the adhesion of cancer cells was 2.5–3 times higher in all rough surfaces as compared to the untreated ones, whereas their proliferation rate was considerably improved on the rough surfaces prepared through plasma treatment for 5 and 10 min. Besides, the morphology of cancer cells was not affected on all the micro-nanostructured surfaces tested. The preference of cancer cells for adhesion and proliferation on highly rough surfaces compared to normal cells was exploited for enrichment of cancer cells in co-cultures with normal ones. Thus, for cancer to normal cell seeding ratios from 1/50 to 1/200, after 3 days of culture, enrichment ratios of about 48.5 ± 1.6 were obtained for the 10-min treated micro-nanostructured surfaces as compared to enrichment ratios of 13.8 ± 0.9 obtained for the untreated surfaces. A detailed Fourier and multifractal analysis shows for the first time that this increased enrichment of cancer cells follows the increased surface disorder of the rough surfaces. Moreover, the enhanced adhesion of cancer cells with respect to normal ones onto plasma micro/nanostructured surfaces was investigated under flow conditions using microchannels with micro-nanostructured bottom. In this case, an enrichment ratio of cancer to normal cells of 1.5 was determined compared to 0.5 obtained for the untreated PMMA after 1-h culture with the surface. These results demonstrate the great potential of plasma micro-nanostructured PMMA plates for enrichment of cancer cells from mixtures with normal ones. © 2019

The enrichment of cancer cell population when in mixtures with normal ones is of great importance for cancer diagnosis. In this work, poly(methyl methacrylate) films have been processed applying different oxygen plasma conditions to fabricate surfaces with structure height ranging from 22 to more than 2000 nm. The surfaces were then evaluated with respect to adhesion and proliferation of both normal and cancer human cells. In particular, normal skin and lung fibroblasts, and four different cancer cell lines, A431 (skin cancer), HT1080 (fibrosarcoma), A549 (lung cancer), and PC3 (prostate cancer), have been employed. It was found that adhesion and proliferation of cancer cells was favored when cultured onto the hierarchical micro/nanostructured surfaces as compared to untreated ones with the maximum values obtained for substrates treated at −100 V for 3 min. On the other hand, although the adhesion of normal fibroblasts was not influenced by the micro/nanostructured surfaces, their morphology and proliferation was significantly impaired, especially after 3-day culture on these surfaces. The reduced proliferation rate of adherent fibroblasts was linked to reduced focal points formation, as it was verified through vinculin staining, and not to apoptosis. The micro/nanostructured surfaces prepared with plasma treatment at −100 V for 3 min (hierarchical topography with mean height of ∼800 nm) were selected as substrates for normal and cancer cell co-culture experiments. It was found that 25–80 times enrichment of cancer over the normal cells was achieved on the nanostructured surfaces after 3-day culture, while it was 5–8 times lower on the untreated ones. It should be noticed that this is the first time such high enrichment ratios are achieved without implementing surfaces modified with binding molecules specific for cancer cells. Thus, the nanostructured surfaces hold a strong promise as culture substrates for separation and enrichment of cancer cells from mixtures with normal ones that should find application in cancer diagnostics. © 2019 Elsevier B.V.

The genus Strychnos (Loganiaceae) is well-known as a rich source of various bioactive metabolites. In continuation of our phytochemical studies on plants from Amazonia, we examined Strychnos aff. darienensis, collected in Peru. This species has been traditionally used in South America and is still presently used as a drug by the Yanesha tribe in Peru. Phytochemical investigation of this plant led to the isolation and structure elucidation by NuclearMagnetic Resonance and High Resolution Mass Spectroscopy of 14 compounds that belong to the categories of phenolic acids [p-hydroxybenzoic acid (1) and vanillic acid (2)], flavonoids [luteolin, (3),3-O-methyl quercetin (4), strychnobiflavone (5), minaxin (6) and 3',4',7-trihydroxy-flavone (7)], lignans [syringaresinol-b-D-glucoside (8), balanophonin (9) and ficusal (10)] and alkaloids [venoterpine (11), 11-methoxyhenningsamine (12), diaboline (13) and 11-methoxy diaboline (14)]. The isolated flavonoids-a class known for its anti-aging activities-were further evaluated for their biological activities on normal human skin fibroblasts. Among them, only (6), and to a lesser extent (7), exhibited cytotoxicity at 100 μg/ml. All five flavonoids suppressed intracellularreactive oxygen species (ROS) levels, either basal or following stimulation with hydrogen peroxide or both. Moreover, luteolin and strychnobiflavone protected skin fibroblasts against ultraviolet (UV)-irradiation-induced cell death. The isolated flavonoids could prove useful bioactive ingredients in the cosmetic industry. © 2019 by the authors.

Intervertebral discs (IVDs) are the joints of the spine, mainly consisting of extracellular matrix (ECM) with a low number of cells embedded therein. Low cellularity stems from nutrient deprivation due to the lack of blood supply, as well as from the hypoxic and hyperosmotic conditions prevailing in the tissue. Intervertebral disc degeneration (IDD) has been firmly connected with low back pain, a major age-related disease, whereas degenerated discs have been characterized by increased proteolytic activity and accumulation of senescent cells. While the catabolic phenotype of senescent IVD cells has been documented, whether this phenotype is preserved under the harsh conditions met in the IVD milieu has never been investigated. Here we showed that a combination of low glucose, hypoxia, high osmolality and absence of serum is anti-proliferative for young disc cells. In addition, we demonstrated for the first time that classical senescence markers, namely p16INK4a, p21WAF1 and ICAM-1, remain up-regulated in senescent cells under these conditions. Finally, up-regulation of the main senescence-associated ECM degrading enzymes, i.e. MMP-1, -2 and -3 was maintained in this strict environment. Conservation of IVD cells’ senescent phenotype under the actual conditions these cells are confronted with in vivo further supports their possible implication in IDD. © 2018 Elsevier B.V.

Objective. Adipose tissue stem cells (ADSCs) present a promising therapeutic method to alleviate liver failure (LF). The purpose of this prospective study was to evaluate the efficacy of undifferentiated ADSC transplantation on liver regeneration and on the expression of liver regeneration- and liver-specific genes, following 60% partial hepatectomy (PHx). Methods. Sixty female rats were subjected to PHx and were transplanted with 106 or 2 × 106 ADSCs, either into the portal vein (PV) or into the hepatic parenchyma. Animals of the control group were not transplanted and served as controls. Animals were sacrificed on the 4th, the 7th, or the 15th postoperative day (POD). Results. The transplanted ADSCs were successfully engrafted into the liver parenchyma and ameliorated the histopathologic damage on the 7th and 15th POD. All transplanted animals demonstrated a significantly higher liver regeneration rate on the 4th and 7th POD, compared with the control group. The expression of hepatocyte growth factor, a-fetoprotein, tyrosine aminotransferase, hepatocyte nuclear factor 4a, and cytochrome P450 1A2 was significantly upregulated, compared with the control group. Conclusions. Although undifferentiated, ADSC transplantation significantly enhanced the liver regeneration process. These findings may be proven clinically valuable, especially in cases of acute LF. Copyright © 2018 Konstantinos G. Apostolou et al.

Telomerase is the enzyme that maintains telomere length by adding telomeric repeats after each cell division. Numerous metabolic factors such as obesity, insulin resistance or physical inactivity have been associated with shortened telomeres. In the present study, we assessed telomerase activity in diabetic patients having or not foot ulcer. A total of 90 adult patients with type 2 diabetes mellitus (T2DM) were studied. Patients were allocated into two groups according to the absence or presence of active foot ulcers as follows: Νon-ulcer group (N=58) and ulcer group (N=32). Our data revealed that the patients with diabetic ulcers had significantly greater waist circumference and neuropathy disability score, while exhibiting lower telomerase activity, indicating the possible existence of a common clinical profile among ulcer-bearing diabetic patients. Validation of our findings by extending the study in larger patient groups may contribute to the understanding of T2DM pathophysiology and its main clinical implications. © 2018, Spandidos Publications. All rights reserved.

Cellular senescence contributes to organismal development, aging, and diverse pathologies, yet available assays to detect senescent cells remain unsatisfactory. Here, we designed and synthesized a lipophilic, biotin-linked Sudan Black B (SBB) analogue suitable for sensitive and specific, antibody-enhanced detection of lipofuscin-containing senescent cells in any biological material. This new hybrid histo-/immunochemical method is easy to perform, reliable, and universally applicable to assess senescence in biomedicine, from cancer research to gerontology. © 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Objective: To compare the mechanotransduction caused by cyclic and static mechanical strains in human periodontal ligament fibroblasts (hPDLFs) cultured under identical conditions. Materials and methods: hPDLFs, originating from the same donors, were exposed either to cyclic or to static tensile strain using specially designed devices and under identical culture conditions. Activation of all members of mitogen-activated protein kinases (MAPKs) was monitored by western immunoblot analysis. Expression levels of immediate/early genes c-fos and c-jun were assessed with quantitative real-time polymerase chain reaction. Results: Time course experiments revealed that both types of stresses activate the three members of MAPK, that is ERK, p38, and JNK, with cyclic stress exhibiting a slightly more extended activation. Further downstream, both stresses upregulate the immediate/early genes c-fos and c-jun, encoding components of the activator protein-1 (AP-1), a key transcription factor in osteoblastic differentiation; again cyclic strain provokes a more intense upregulation. Six hours after the application of both strains, MAPK activation and gene expression return to basal levels. Finally, cells exposed to cyclic stress for longer periods are distributed approximately perpendicular to the axis of the applied strain, whereas cells exposed to static loading remain in a random orientation in culture. Conclusion: The findings of the present study indicate similar, although not identical, immediate/ early responses of hPDLs to cyclic and static stretching, with cyclic strain provoking a more intense adaptive response of these cells to mechanical deformation. © The Author 2017. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved.

Autophagy is a catabolic process that preserves cellular homeostasis. Its exact role during carcinogenesis is not completely defined. Specifically in head and neck cancer, such information from clinical settings that comprise the whole spectrum of human carcinogenesis is very limited. Towards this direction, we examined the in situ status of the autophagy-related factors, Beclin-1, microtubule-associated protein 1 light chain 3, member B (LC3B) and sequestosome 1/p62 (p62) in clinical material covering all histopathological stages of human head and neck carcinogenesis. This material is unique as each panel of lesions is derived from the same patient and moreover we have previously assessed it for the DNA damage response (DDR) activation status. Since Beclin-1, LC3B and p62 reflect the nucleation, elongation and degradation stages of autophagy, respectively, their combined immunohistochemical (IHC) expression profiles could grossly mirror the autophagic flux. This experimental approach was further corroborated by ultrastructural analysis, applying transmission electron microscopy (TEM). The observed Beclin-1/LC3B/p62 IHC patterns, obtained from serial sections analysis, along with TEM findings are suggestive of a declined authophagic activity in preneoplastic lesions that was restored in full blown cancers. Correlating these findings with DDR status in the same pathological stages are indicative of: (i) an antitumor function of autophagy in support to that of DDR, possibly through energy deprivation in preneoplastic stages, thus preventing incipient cancer cells from evolving; and (ii) a tumor-supporting role in the cancerous stage. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.

The dielectric properties of biological tissues can contribute non-invasively to a better characterization and understanding of the structural properties and physiology of living organisms. The question we asked, is whether these induced changes are effected by an endogenous or exogenous cellular stress, and can they be detected non-invasively in the form of a dielectric response, e.g., an AC conductivity switch in the broadband frequency spectrum. This study constitutes the first methodological approach for the detection of environmental stress-induced damage in mammalian tissues by the means of broadband dielectric spectroscopy (BDS) at the frequencies of 1–106 Hz. Firstly, we used non-ionizing (NIR) and ionizing radiation (IR) as a typical environmental stress. Specifically, rats were exposed to either digital enhanced cordless telecommunication (DECT) radio frequency electromagnetic radiation or to γ-radiation, respectively. The other type of stress, characterized usually by high genomic instability, was the pathophysiological state of human cancer (lung and prostate). Analyzing the results of isothermal dielectric measurements provided information on the tissues’ water fraction. In most cases, our methodology proved sufficient in detecting structural changes, especially in the case of IR and malignancy. Useful specific dielectric response patterns are detected and correlated with each type of stress. Our results point towards the development of a dielectric-based methodology for better understanding and, in a relatively invasive way, the biological and structural changes effected by radiation and developing lung or prostate cancer often associated with genomic instability. © 2017 by the authors; licensee MDPI, Basel, Switzerland.

Fragestellung: Die Bandscheibendegeneration ist häufig mit erhöhten Konzentrationen von Entzündungsfaktoren wie IL-1 beta (IL-1ß) und TNF alpha verbunden, die für ein Milieu sorgen, das die Matrixbildung eher beeinträchtigt und für regenerative Zelltherapien eine Herausforderung[zum vollständigen Text gelangen Sie über die oben angegebene URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2016)

The cell surface proteoglycan syndecan 1 (SDC1) is overexpressed in the malignant breast stromal fibroblasts, creating a favorable milieu for tumor cell growth. In the present study, we found that ionizing radiation, a well-established treatment in human breast cancer, provokes premature senescence of human breast stromal fibroblasts in vitro, as well as in the breast tissue in vivo. These senescent cells were found to overexpress SDC1 both in vitro and in vivo. By using a series of specific inhibitors and siRNA approaches, we showed that this SDC1 overexpression in senescent cells is the result of an autocrine action of Transforming Growth Factor-β (TGF-β) through the Smad pathway and the transcription factor Sp1, while the classical senescence pathways of p53 or p38 MAPK - NF-kB are not involved. In addition, the highly invasive human breast cancer cells MDA-MB-231 (in contrast to the low-invasive MCF-7) can also enhance SDC1 expression, both in early-passage and senescent fibroblasts via a paracrine action of TGF-β. The above suggest that radiation-mediated premature senescence and invasive tumor cells, alone or in combination, enhance SDC1 expression in breast stromal fibroblasts, a poor prognostic factor for cancer growth, and that TGF-β plays a crucial role in this process.

A number of new 3,7-disubstituted pyrazolo[3,4-c]pyridines have been designed and synthesized from suitable 2-aminopyridines. The antiproliferative activity of the derivatives was determined against the pancreatic MIA PaCa-2 and ovarian SCOV3 cancer cell-lines. IC50values of the most promising analogue 46 lie in the submicromolar or low micromolar range. Furthermore, compound 46 shows similar inhibitory activities against DU145, A2058 and PC-3 cancer cells, blocks the cell cycle at the G0/G1phase and induce apoptosis, as determined by the appearance of apoptotic nuclei. © 2016 Elsevier Ltd

The cyclin-dependent kinase inhibitor p21 WAF1/CIP1 (p21) is a cell-cycle checkpoint effector and inducer of senescence, regulated by p53. Yet, evidence suggests that p21 could also be oncogenic, through a mechanism that has so far remained obscure. We report that a subset of atypical cancerous cells strongly expressing p21 showed proliferation features. This occurred predominantly in p53-mutant human cancers, suggesting p53-independent upregulation of p21 selectively in more aggressive tumour cells. Multifaceted phenotypic and genomic analyses of p21-inducible, p53-null, cancerous and near-normal cellular models showed that after an initial senescence-like phase, a subpopulation of p21-expressing proliferating cells emerged, featuring increased genomic instability, aggressiveness and chemoresistance. Mechanistically, sustained p21 accumulation inhibited mainly the CRL4-CDT2 ubiquitin ligase, leading to deregulated origin licensing and replication stress. Collectively, our data reveal the tumour-promoting ability of p21 through deregulation of DNA replication licensing machinery - an unorthodox role to be considered in cancer treatment, since p21 responds to various stimuli including some chemotherapy drugs. © 2016 Macmillan Publishers Limited.

Ionizing radiation (IR) has been described as a double-edged sword, since it is used for diagnostic and therapeutic medical applications, and at the same time it is a well known human mutagen and carcinogen, causing wide-ranging chromosomal aberrations. It is nowadays accepted that the detrimental effects of IR are not restricted only in the irradiated cells, but also to non-irradiated bystander or even distant cells manifesting various biological effects. This review presents the role of oxidative stress in the induction of bystander effects referring to the types of the implicated oxidative DNA lesions, the contributing intercellular and intracellular stress mediators, the way they are transmitted from irradiated to bystander cells and finally, the complex role of the bystander effect in the therapeutic efficacy of radiation treatment of cancer. © 2014 Elsevier Ireland Ltd.

Objectives To evaluate the chemical, mechanical, and biological properties of modern composite surface sealers (CSS) having different compositions. Methods The CSS products tested were Biscover LV (BC), Durafinish (DF), G-Coat Plus (GC), and Permaseal (PS). The tests performed were: (A): degree of conversion (DC%) by ATR-FTIR spectroscopy; (B): thickness of O2-inhibition layer by transmission optical microscopy; (C): surface hardness, 10 min after irradiation and following 1 week water storage, employing a Vickers indenter (VHN); (D): color (ΔE∗) and gloss changes (ΔGU) after toothbrush abrasion, using L∗a∗b∗colorimetry and glossimetry; (E): accelerated wear (GC,PS only) by an OHSU wear simulator plus 3D profilometric analysis, and (F): cytotoxicity testing of aqueous CSS eluents on human gingival fibroblast cultures employing the methyl-3H thymidine DNA labeling method. Statistical analyses included 1-way (A, B, ΔE∗, ΔGU) and 2-way (C, F) ANOVAs, plus Tukey post hoc tests. Student's t-test was used to evaluate the results of the accelerated wear test (α = 0.05 for all). Results The rankings of the statistical significant differences were: (A) PS (64.9) > DF,BC,GC (56.1-53.9) DC%; (B) DF,PS (12.3,9.8) > GC,BC (5.2,4.8) μm; (C): GC (37.6) > BC,DF (32.6,31.1) > PS (26.6) VHN (10 min/dry) and BC,DF (29.3,28.7) > GC(26.5) > PS(21.6) VHN (1w/water), with no significant material/storage condition interaction; (D): no differences were found among GC,DF,BC,PS (0.67-1.11) ΔE∗, with all values within the visually acceptable range and PS,BC (32.8,29.4) > GC,DF (19.4,12.9) ΔGU; (E): no differences were found between GC and PS in volume loss (0.10,0.11 mm3), maximum (113.9,130.5 μm) and mean wear depths (30.3,27.5 μm); (F): at 1% v/v concentration, DF showed toxicity (23% vital cells vs 95-102% for others). However, at 5% v/v concentration DF (0%) and BC (9%) were the most toxic, whereas GC (58%) and PS (56%) showed moderate toxicity. Significance Important chemical, mechanical, and biological properties exist among the CSS tested, which may affect their clinical performance. © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

A library of 600 taxonomically diverse Panamanian plant extracts was screened for DPPH scavenging and UV-B protective activities, and the methanolic extracts of Mosquitoxylum jamaicense, Combretum cacoucia, and Casearia commersionia were submitted to HPLC-based activity profiling. The compounds located in the active time windows were isolated and identified as gallic acid derivatives and flavonoids. Gallic acid methyl ester (3) and digallic acid derivatives (2, 6) showed the highest DPPH scavenging activity (

Olive mill waste water is the major byproduct of the olive oil industry containing a range of compounds related to Olea europaea and olive oil constituents. Olive mill waste water comprises an important environmental problem in olive oil producing countries, but it is also a valuable material for the isolation of high added value compounds. In this study, an attempt to investigate the secoiridoid content of olive mill waste water is described with the aid of ultrahigh-performance liquid chromatography-electrospray ionization (±)-high-resolution mass spectrometry and centrifugal partition chromatography methods. In total, seven secoiridoid lactones were isolated, four of which are new natural products. This is the first time that a conjugate of hydroxytyrosol and a secoiridoid lactone has been isolated from olive mill waste water and structurally characterized. Furthermore, the range of isolated compounds allowed for the proposal of a hypothesis for the biotransformation of olive secoiridoids during the production of olive mill waste water. Finally, the ability of the representative compounds to reduce the intracellular reactive oxygen species was assessed with the dichlorofluorescein assay in conjunction with the known antioxidant agent hydroxytyrosol. © Georg Thieme Verlag KG Stuttgart, New York.

Mechanical loading is considered to be a major parameter of the periodontal ligament (PDL) remodeling and differentiation. However, the molecular mechanisms that translate these forces to cellular responses are not fully elucidated. Especially, although aging affects PDL homeostasis, the role of cellular senescence on the activation of signaling pathways in periodontal ligament fibroblasts (PDLF) in response to mechanical stimulation has not been studied yet. Here, we present evidence showing that cyclic mechanical stimulation activates ERK, JNK and p38 MAPK in young (early-passage) human PDLF, in a RhoK-dependent manner. This response was found to be independent of the substratum (i.e. fibronectin or collagen) on which these cells grow. Stretching up-regulates also c-fos, a classical cellular response to mechanical deformation. Inhibition of ERK and JNK reduces, while that of p38 enhances stress-mediated c-fos expression. In addition, cyclic stretching stimulates the expression and activity of alkaline phosphatase ( ALP), an early marker of osteoblastic differentiation. We have recently shown that senescent human PDLF have a significantly decreased expression of ALP, linked to an inability towards osteoblastic differentiation. Here, we found that senescent PDLF are able to respond to cyclic mechanical stretching by activating ERK, JNK and p38 MAPK, with similar kinetics compared to young cells, and by up-regulating c-fos and ALP expression and activity. However, even after stimulation, ALP levels in senescent cells are still much lower compared to the basal levels of their young counterparts, suggesting that senescence impairs the differentiation of human PDLF when subjected to cyclic mechanical deformation. © 2014 Elsevier Inc.

The DNA damage response (DDR) pathway and ARF function as barriers to cancer development. Although commonly regarded as operating independently of each other, some studies proposed that ARF is positively regulated by the DDR. Contrary to either scenario, we found that in human oncogene-transformed and cancer cells, ATM suppressed ARF protein levels and activity in a transcription-independent manner. Mechanistically, ATM activated protein phosphatase 1, which antagonized Nek2-dependent phosphorylation of nucleophosmin (NPM), thereby liberating ARF from NPM and rendering it susceptible to degradation by the ULF E3-ubiquitin ligase. In human clinical samples, loss of ATM expression correlated with increased ARF levels and in xenograft and tissue culture models, inhibition of ATM stimulated the tumour-suppressive effects of ARF. These results provide insights into the functional interplay between the DDR and ARF anti-cancer barriers, with implications for tumorigenesis and treatment of advanced tumours. © 2013 Macmillan Publishers Limited. All rights reserved.

Loss of teeth increases with age or after genotoxic treatments, like head and neck radiotherapy, due to periodontium breakdown. Periodontal ligament fibroblasts represent the main cell type in this tissue and are crucial for the maintenance of homeodynamics and for its regeneration. Here, we have studied the characteristics of human periodontal ligament fibroblasts (hPDLF) that became senescent after replicative exhaustion or after exposure to ionizing radiation, as well as their ability for osteoblastic differentiation. We found that senescent hPDLF express classical markers of senescence, as well as a catabolic phenotype, as shown by the decrease in collagen type I and the increase of MMP-2 expression. In addition, we observed a considerably decreased expression of the major transcription factor for osteoblastic differentiation, i.e. Runx2, a down-regulation which was found to be p53-dependent. In accordance to the above, senescent cells have a significantly decreased alkaline phosphatase gene expression and activity, as well as a reduced ability for osteoblastic differentiation, as found by Alizarin Red staining. Interestingly, cells from both type of senescence express similar characteristics, implying analogous functions in vivo. In conclusion, senescent hPDLF express a catabolic phenotype and express a significantly decreased ability towards an osteoblastic differentiation, thus probably affecting tissue development and integrity. © 2013 Springer Science+Business Media Dordrecht.

Intervertebral disc (IVD) degeneration is accompanied by growth factor-overexpression and increased cell proliferation, probably representing a tissue repair process. Accordingly, we studied the effect of exogenous and autocrine growth factors on the proliferation of human IVD cells. We observed that Platelet-Derived Growth Factor (PDGF), basic Fibroblast Growth Factor (bFGF), and Insulin-like Growth Factor-I (IGF-I) stimulate DNA synthesis of human IVD cells, through the activation of the MEK/ERK and the PI-3K/Akt signal transduction pathways. Furthermore, medium conditioned (CM) by IVD cells induced DNA synthesis in the same cells, indicating the secretion of autocrine growth factors. The MEK/ERK and PI-3K/Akt pathways were also induced by CM, while their inhibition reversed in large part the DNA synthesis induction by CM. These responses to the exogenous and autocrine growth factors were qualitatively similar in both nucleus pulposus (NP) and annulus fibrosus (AF) cell cultures. Immunohistochemical studies in human biopsies showed significant activation of both signaling pathways, which was most prominent in the clusters of proliferating cells. These in vitro and in vivo data indicate that the proliferation of human IVD cells is regulated by exogenous and autocrine growth factors mainly via the MEK/ERK and PI-3K/Akt pathways; this may contribute to the design of future interventional approaches. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Background: Human rhinoviruses, major precipitants of asthma exacerbations, induce lower airway inflammation and mediate angiogenesis. The purpose of this study was to assess the possibility that rhinoviruses may also contribute to the fibrotic component of airway remodeling. Methods: Levels of basic fibroblast growth factor (bFGF) mRNA and protein were measured following rhinovirus infection of bronchial epithelial cells. The profibrotic effect of epithelial products was assessed by DNA synthesis and matrix metalloproteinase activity assays. Moreover, epithelial cells were exposed to supernatants from cultured peripheral blood mononuclear cells, obtained from healthy donors or atopic asthmatic subjects and subsequently infected by rhinovirus and bFGF release was estimated. bFGF was also measured in respiratory secretions from atopic asthmatic patients before and during rhinovirus-induced asthma exacerbations. Results: Rhinovirus epithelial infection stimulated mRNA expression and release of bFGF, the latter being positively correlated with cell death under conditions promoting rhinovirus-induced cytotoxicity. Supernatants from infected cultures induced lung fibroblast proliferation, which was inhibited by anti-bFGF antibody, and demonstrated increased matrix metalloproteinase activity. Rhinovirus-mediated bFGF release was significantly higher in an in vitro simulation of atopic asthmatic environment and, importantly, during rhinovirus-associated asthma exacerbations. Conclusions: Rhinovirus infection induces bFGF release by airway epithelium, and stimulates stroma cell proliferation contributing to airway remodeling in asthma. Repeated rhinovirus infections may promote asthma persistence, particularly in the context of atopy; prevention of such infections may influence the natural history of asthma. © 2012 Skevaki et al.; licensee BioMed Central Ltd.

Grape stems constitute a scarcely investigated class of vinification byproducts with limited reports on their bioactive polyphenol content and/or industrial applications. Herein we present the outcome of our investigation on various grape stems extracts from native Greek grape varieties, concerning the assessment of their total polyphenolic content (TPC), the quantification of the individual bioactive polyphenols and the detailed evaluation of their antioxidant properties. Results obtained indicate that grape stems are particularly rich in flavonoids and stilbenes, with trans-resveratrol and e{open}-viniferin present in considerably high concentrations. They also exhibit significant antioxidant properties, which were determined by DPPH • radical scavenging and FRAP assays (modified to fit into a high throughput approach). Additional experiments concerning the inhibition of CuSO 4-induced LDL oxidation and the reduction of intracellular reactive oxygen species (ROS) indicated that most extracts tested display an extreme capability to prevent the oxidation of LDL-lipoprotein at very low concentrations and to reduce the intracellular ROS levels, exhibiting IC 75 values between 10.4 μg and 49.1 μg per gram of extract. Results herein reveal that grape stems represent a rich source of high added value natural antioxidants, particularly stilbenes such as trans-resveratrol, which may be used by pharmaceutical, food and cosmetic industries. © 2012 Elsevier Ltd.

Figure represented. With the aim of enlightening some structure-activity correlation within the pyranoxanthenone series, we have designed and synthesized a number of new 5-aminosubstituted pyrano[3,2-b]xanthen-6-ones bearing various 12-substituents. In vitro cytotoxic potencies of the new derivatives toward the murine leukemia L1210 cell line, human colorectal adenocarcinoma (HT-29), and human uterine sarcoma (MES-SA and its 100-fold resistant to doxorubicin variant MES-SA/Dx5) cell lines, are described and compared with that of reference drugs. Among the studied compounds, those possessing a second aminosubstituted side-chain exhibit interesting cytotoxic activity against the solid tumor cell lines, and they retain activity against the multidrug resistant MES-SA/Dx5 subline. Their selective effect on a phase of the cell cycle was evaluated using HT-29 cells providing evidence that the compounds induce a G0/G1 arrest. © 2011 HeteroCorporation.