A subset of human dermal fibroblasts overexpressing Cockayne syndrome group B protein resist UVB radiation-mediated premature senescence.

Ultraviolet B (UVB) radiation is a major contributor to skin photoaging. Although mainly absorbed by the epidermis, UVB photons managing to penetrate the upper dermis affect human dermal fibroblasts (HDFs), leading, among others, to the accumulation of senescent cells. In vitro studies have shown that repeated exposures to subcytotoxic UVB radiation doses provoke HDFs' premature senescence shortly after the end of the treatment period.

Design and Synthesis of Novel Antioxidant 2-Substituted-5,7,8-Trimethyl-1,4-Benzoxazine Hybrids: Effects on Young and Senescent Fibroblasts.

The exponential growth of the aged population worldwide is followed by an increase in the prevalence of age-related disorders. Oxidative stress plays central role in damage accumulation during ageing and cell senescence. Thus, a major target of today's anti-ageing research has been focused on antioxidants counteracting senescence.

Plant-Derived Senotherapeutics for the Prevention and Treatment of Intervertebral Disc Degeneration and Aging.

Chronic low back pain, a major cause of disability with a great global socioeconomic impact, has been inextricably associated with intervertebral disc degeneration. On the other hand, an enhanced number of senescent cells has been identified in aged and degenerated intervertebral discs and their senescence-associated secretory phenotype (SASP) has been connected with qualitative/quantitative alterations in the extracellular matrix and ultimately with the disturbance of tissue homeostasis. Given that selective elimination of senescent cells (by the so-called senolytics) or amendment of their secretome towards a less catabolic/inflammatory phenotype (by molecules known as senomorphics) has been reported to alleviate symptoms of several age-associated diseases and to improve tissue quality during aging, here we will review the emerging role of senolytic and senomorphic agents derived from plants and natural products against intervertebral disc degeneration.

Synthesis, cytotoxic activity evaluation and mechanistic investigation of novel 3,7-diarylsubstituted 6-azaindoles.

A number of new disubstituted 6-azaindoles have been designed and synthesized bearing a crucial structural modification in respect to an analogous antiproliferative hit compound. The synthesis was performed using 2-amino-3-nitro-4-picoline, that was suitably modified and converted to 7-chloro-3-iodo-6-azaindole and this central scaffold was used for successive Suzuki-type couplings, to result in the target compounds. The evaluation of the cytotoxic activity was performed against four human cancer cell lines, as well as a normal human fibroblast strain.

Senescence-associated alterations in the extracellular matrix: deciphering their role in the regulation of cellular function.

The extracellular matrix (ECM) is a dynamic structural network that provides a physical scaffolding, as well as biochemical factors that maintain normal tissue homeostasis and thus its disruption is implicated in many pathological conditions. On the other hand, senescent cells express a particular secretory phenotype, affecting the composition and organization of the surrounding ECM and modulating their microenvironment. As accumulation of senescent cells may be linked to the manifestation of several age-related conditions, senescence-associated ECM alterations may serve as targets for novel anti-aging treatment modalities.

Heterogeneity of Cellular Senescence: Cell Type-Specific and Senescence Stimulus-Dependent Epigenetic Alterations.

The aim of the present study was to provide a comprehensive characterization of whole genome DNA methylation patterns in replicative and ionizing irradiation- or doxorubicin-induced premature senescence, exhaustively exploring epigenetic modifications in three different human cell types: in somatic diploid skin fibroblasts and in bone marrow- and adipose-derived mesenchymal stem cells. With CpG-wise differential analysis, three epigenetic signatures were identified: (a) cell type- and treatment-specific signature; (b) cell type-specific senescence-related signature; and (c) cell type-transversal replicative senescence-related signature. Cluster analysis revealed that only replicative senescent cells created a distinct group reflecting notable alterations in the DNA methylation patterns accompanying this cellular state.

Activation of the JNKs/ATM-p53 axis is indispensable for the cytoprotection of dermal fibroblasts exposed to UVB radiation.

Although UVB radiation is mainly absorbed by the epidermis, ~5-10% of its photons reach and affect the upper part of the dermis. Physiologically relevant UVB doses, able to provoke erythema, induce apoptosis in human dermal fibroblasts in vitro, as well as in the dermis of SKH-1 mice. Given the sparse and even contradictory existing information on the effect of UVB radiation on dermal fibroblasts' viability, aim of this work was to unravel the crucial signaling pathways regulating the survival of UVB-treated human dermal fibroblasts.

Decreased differentiation capacity and altered expression of extracellular matrix components in irradiation-mediated senescent human breast adipose-derived stem cells.

Radiotherapy is widely used for the treatment of breast cancer. However, we have shown that ionizing radiation can provoke premature senescence in breast stromal cells. In particular, breast stromal fibroblasts can become senescent after irradiation both in vitro and in vivo and they express an inflammatory phenotype and an altered profile of extracellular matrix components, thus facilitating tumor progression.

Bone turnover markers in gingival crevicular fluid and blood serum of patients with fixed orthodontic appliances.

Aim: Bone remodelling can be followed through the bone turnover markers (BTMs). Aim of the present study was to record the fluctuation of an osteoclastic and an osteoblastic BTM [C-terminal telopeptide of type I collagen (CTX) and N-terminal pro-peptide of type I pro-collagen (PINP), respectively] in both the gingival crevicular fluid (GCF) and the serum of orthodontic patients before and after the initial application of orthodontic forces.

Materials And Methods: Twenty-one Caucasian patients were prospectively evaluated.

Virulence Potential, Surface Attachment, and Transcriptional Response of Sublethally Injured Listeria monocytogenes following Exposure to Peracetic Acid.

The disinfectant peracetic acid (PAA) can cause high levels of sublethal injury to Listeria monocytogenes. This study aims to evaluate phenotypic and transcriptional characteristics concerning the surface attachment and virulence potential of sublethally injured L. monocytogenes ScottA and EGDe after exposure to 0.

Phytochemical Study and In Vitro Screening Focusing on the Anti-Aging Features of Various Plants of the Greek Flora.

Skin health is heavily affected by ultraviolet irradiation from the sun. In addition, senile skin is characterized by major changes in the collagen, elastin and in the hyaluronan content. Natural products (NPs) have been shown to delay cellular senescence or in vivo aging by regulating age-related signaling pathways.

Down-Regulation of the Proteoglycan Decorin Fills in the Tumor-Promoting Phenotype of Ionizing Radiation-Induced Senescent Human Breast Stromal Fibroblasts.

Down-regulation of the small leucine-rich proteoglycan decorin in the stroma is considered a poor prognostic factor for breast cancer progression. Ionizing radiation, an established treatment for breast cancer, provokes the premature senescence of the adjacent to the tumor stromal fibroblasts. Here, we showed that senescent human breast stromal fibroblasts are characterized by the down-regulation of decorin at the mRNA and protein level, as well as by its decreased deposition in the pericellular extracellular matrix in vitro.

Differential Modulation of Listeria monocytogenes Fitness, Virulence, and Transcription of Virulence-Associated Genes in Response to the Presence of Different Microorganisms.

Interactions between and food-associated or environmental bacteria are critical not only for the growth but also for a number of key biological processes of the microorganism. In this regard, limited information exists on the impact of other microorganisms on the virulence of In this study, the growth of was evaluated in a single culture or in coculture with , , , or in tryptic soy broth (10°C/10 days and 37°C/24 h). Transcriptional levels of 9 key virulence genes (, , , , , , , , and ) and invasion efficiency and intracellular growth in Caco-2 cells were determined for following growth in mono- or coculture for 3 days at 10°C or 9 h at 37°C.

Bioprospecting Sponge-Associated Marine Cyanobacteria to Produce Bioactive Compounds.

Marine cyanobacteria are considered a prolific source of bioactive natural products with a range of biotechnological and pharmacological applications. However, data on the production of natural compounds from sponge-associated cyanobacteria are scarce. This study aimed to assess the potential of sponge-associated cyanobacteria strains representing different taxonomic groups for the production of bioactive compounds and the biological activity of their extracts.

The role of senescence in cancer development.

While research on cancer development is traditionally focusing mainly on the neoplastic cell per se, nowadays the role of tumor stroma in this process is indisputable. The stroma - mainly composed of extracellular matrix (ECM) - is a source of mediators and signals originating from heterotypic cell-cell and cell-matrix interactions that steer the progression of the disease in a context- and a cancer type-dependent manner. With advancing age the stroma exhibits alterations, important being the accumulation of senescent cells.

Guided cell adhesion, orientation, morphology and differentiation on silicon substrates photolithographically micropatterned with a cell-repellent cross-linked poly(vinyl alcohol) film.

In this work, silicon substrates with poly(vinyl alcohol) (PVA) patterns created by a simple, low-cost and high-fidelity photolithographic procedure were evaluated with respect to cell adhesion and alignment, viability, metabolic activity, proliferation and cell cycle progression using the human glioblastoma cell-line U87MG and human skin fibroblasts. In addition, rat adrenal pheochromocytoma cells (PC-12) were employed to evaluate a modified photolithographic protocol appropriate for adhesion of cells requiring extracellular matrix components to adhere on the surface and to demonstrate that the proposed patterned substrates could provide unhindered cell differentiation. Regarding U87MG cells and skin fibroblasts, it was found that as the stripes width increased from 10 to 50 μm, the percentage of cells attached to Si versus the total area (Si + PVA) increased from 78% and 72% to 98.

Nrf2-Mediated Fibroblast Reprogramming Drives Cellular Senescence by Targeting the Matrisome.

Nrf2 is a key regulator of the antioxidant defense system, and pharmacological Nrf2 activation is a promising strategy for cancer prevention and promotion of tissue repair. Here we show, however, that activation of Nrf2 in fibroblasts induces cellular senescence. Using a combination of transcriptomics, matrix proteomics, chromatin immunoprecipitation and bioinformatics we demonstrate that fibroblasts with activated Nrf2 deposit a senescence-promoting matrix, with plasminogen activator inhibitor-1 being a key inducer of the senescence program.

Major traits of the senescent phenotype of nucleus pulposus intervertebral disc cells persist under the specific microenvironmental conditions of the tissue.

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.

Scarless wound healing: From development to senescence.

An essential element of tissue homeostasis is the response to injuries, cutaneous wound healing being the most studied example. In the adults, wound healing aims at quickly restoring the barrier function of the skin, leading however to scar, a dysfunctional fibrotic tissue. On the other hand, in fetuses a scarless tissue regeneration takes place.

Assessment of telomerase activity in leukocytes of type 2 diabetes mellitus patients having or not foot ulcer: Possible correlation with other clinical parameters.

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.

Long-term exposure to TNF-α leads human skin fibroblasts to a p38 MAPK- and ROS-mediated premature senescence.

Tumor necrosis factor α (TNF-α) is an inflammatory mediator overexpressed in the skin as a response to ultraviolet radiation, as well as in chronic non-healing wounds. On the other hand, senescent fibroblasts have been shown to accumulate in the skin under these stressful conditions. Accordingly, here we assessed the putative implication of TNF-α in the induction of premature senescence of human adult dermal fibroblasts.

Evaluating the probiotic potential and technological characteristics of yeasts implicated in cv. Kalamata natural black olive fermentation.

In the present study, 49 yeast strains previously isolated from cv. Kalamata table olive fermentation were assessed for their probiotic potential and technological characteristics. The probiotic assays included the in vitro survival in simulated gastric and pancreatic digestions, surface adhesion to the intestinal cell line Caco-2, hydrophobicity, autoaggregation and haemolytic activity.

Extracellular matrix alterations in senescent cells and their significance in tissue homeostasis.

Normal cells after a defined number of successive divisions or after exposure to genotoxic stresses are becoming senescent, characterized by a permanent growth arrest. In addition, they secrete increased levels of pro-inflammatory and catabolic mediators, collectively termed "senescence-associated secretory phenotype". Furthermore, senescent cells exhibit an altered expression and organization of many extracellular matrix components, leading to specific remodeling of their microenvironment.

Monitoring Autophagy Immunohistochemically and Ultrastructurally during Human Head and Neck Carcinogenesis. Relationship with the DNA Damage Response Pathway.

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.