Interleukin-8 prevents oxidative stress-induced human endothelial cell senescence via telomerase activation

Endothelial Senescence in Neurological Diseases

Endothelial cells, which are highly dynamic cells essential to the vascular network, play an indispensable role in maintaining the normal function of the body. Several lines of evidence indicate that the phenotype associated with senescent endothelial cells causes or promotes some neurological disorders. In this review, we first discuss the phenotypic changes associated with endothelial cell senescence; subsequently, we provide an overview of the molecular mechanisms of endothelial cell senescence and its relationship with neurological disorders. For refractory neurological diseases such as stroke and atherosclerosis, we intend to provide some valid clues and new directions for clinical treatment options.

The Combination of Synoeca-MP Antimicrobial Peptide with IDR-1018 Stimulates Proliferation, Migration, and the Expression of Pro-Regenerative Genes in Both Human Skin Cell Cultures and 3D Skin Equivalents

In skin lesions, the development of microbial infection affects the healing process, increasing morbidity and mortality rates in patients with severe burns, diabetic foot, and other types of skin injuries. Synoeca-MP is an antimicrobial peptide (AMP) that exhibits activity against several bacteria of clinical importance, but its cytotoxicity can represent a problem for its positioning as an effective antimicrobial compound. In contrast, the immunomodulatory peptide IDR-1018 presents low toxicity and a wide regenerative potential due to its ability to reduce apoptotic mRNA expression and promote skin cell proliferation. In the present study, we used human skin cells and a 3D skin equivalent models to analyze the potential of the IDR-1018 peptide to attenuate the cytotoxicity of synoeca-MP, as well as the influence of synoeca-MP/IDR-1018 combination on cell proliferation, regenerative processes, and wound repair. We found that the addition of IDR-1018 significantly improved the biological properties of synoeca-MP on skin cells without modifying its antibacterial activity against S. aureus. Likewise, in both melanocytes and keratinocytes, the treatment with synoeca-MP/IDR-1018 combination induces cell proliferation and migration, while in a 3D human skin equivalent model, it can accelerate wound reepithelization. Furthermore, treatment with this peptide combination generates an up-regulation in the expression of pro-regenerative genes in both monolayer cell cultures and in 3D skin equivalents. This data suggests that the synoeca-MP/IDR-1018 combination possesses a good profile of antimicrobial and pro-regenerative activity, opening the door to the development of new strategies for the treatment of skin lesions.

Biopotentials of Collagen Scaffold Impregnated with Plant-Cell-Derived Epidermal Growth Factor in Defective Bone Healing

The combination of scaffolds with recombinant human epidermal growth factor (rhEGF) protein can enhance defective bone healing via synergistic activation to stimulate cellular growth, differentiation, and survival. We examined the biopotentials of an rhEGF-loaded absorbable collagen scaffold (ACS) using a mouse model of calvarial defects, in which the rhEGF was produced from a plant cell suspension culture system because of several systemic advantages. Here, we showed a successful and large-scale production of plant-cell-derived rhEGF protein (p-rhEGF) by introducing an expression vector that cloned with its cDNA under the control of rice α-amylase 3D promoter into rice calli (Oryza sativa L. cv. Dongjin). Implantation with p-rhEGF (5 μg)-loaded ACSs into critical-sized calvarial defects enhanced new bone formation and the expression of osteoblast-specific markers in the defected regions greater than implantation with ACSs alone did. The potency of p-rhEGF-induced bone healing was comparable with that of Escherichia coli-derived rhEGF protein. The exogenous addition of p-rhEGF increased the proliferation of human periodontal ligament cells and augmented the induction of interleukin 8, bone morphogenetic protein 2, and vascular endothelial growth factor in the cells. Collectively, this study demonstrates the successful and convenient production of p-rhEGF, as well as its potency to enhance ACS-mediated bone regeneration by activating cellular responses that are required for wound healing.

Pre-Existing Diabetes Mellitus, Hypertension and KidneyDisease as Risk Factors of Pre-Eclampsia: A Disease of Theories and Its Association with Genetic Polymorphism

Pre-existing diabetes, hypertension and kidney disorders are prominent risk factors of pre-eclampsia (PE). It is a multifactorial pregnancy disorder associated with high blood pressure, proteinuria, and multiorgan failure, which develops after the 20th week of pregnancy. It is one of the most feared pregnancy disorders, as it consumes thousands of fetomaternal lives per annum. According to clinical and pathological studies, the placenta appears to be a key player in the pathogenesis of PE; however, the exact origin of this disorder is still under debate. Defective placentation and angiogenesis are the hallmarks of PE progression. This angiogenic imbalance, together with maternal susceptibility, might determine the severity and clinical presentation of PE. This article comprehensively examines the mechanisms of pathogenesis of PE and current evidence of the factors involved in its progression. Finally, this article will explore the genetic association of PE, various candidate genes, their proposed mechanisms and variants involved in its pathogenesis.

Impact of exposure of human osteoblast cells to titanium dioxide particles in-vitro

Titanium Dental implant is the most successful treatment modality to replace missing teeth today. Although titanium is considered biologically biocompatible, strong, and corrosion-free, the risk of implant failure continues due to bone loss at the expense of optimum oral health. Current research points toward the presence of titanium dioxide (TiO₂) particles leached from dental implant surface, which occurred due to mechanical and chemical insults on the surface. This study aimed to investigate the influence of TiO₂ particles of different sizes leaching from implant surfaces on Human Osteoblast cells (HOB) in-vitro. Titanium dioxide particles in both nano (NPs) and micro (MPs) size and at different concentrations were introduced to human osteoblast cells with and without treatment with vitamin C. Production of ROS was measured using H2DCFDA cellular ROS Assay Kit and MCP-1 and IL-8 cytokines released were assayed at 24 h time point using ELISA technique. Results showed a dose dependent increase in ROS production following exposure of HOB to both nano and micro particles. MCP-1 and IL-8 were released and there was minimal difference between the amount generated by nano compared with micro size particles. Treatment of HOB with antioxidant vitamin C demonstrated a significant reduction in the generation of ROS. At the same time, MCP-1 release was reduced significantly for the 100 μg/mL TiO₂ NPs and MPs after Vitamin C treatment while IL-8 release increased significantly. This study suggests a positive role played by antioxidants in the control of ROS generation and chemokines production in the peri-implant tissue environment.

Endothelial Colony-Forming Cells Dysfunctions Are Associated with Arterial Hypertension in a Rat Model of Intrauterine Growth Restriction

Infants born after intrauterine growth restriction (IUGR) are at risk of developing arterial hypertension at adulthood. The endothelium plays a major role in the pathogenesis of hypertension. Endothelial colony-forming cells (ECFCs), critical circulating components of the endothelium, are involved in vasculo-and angiogenesis and in endothelium repair. We previously described impaired functionality of ECFCs in cord blood of low-birth-weight newborns. However, whether early ECFC alterations persist thereafter and could be associated with hypertension in individuals born after IUGR remains unknown. A rat model of IUGR was induced by a maternal low-protein diet during gestation versus a control (CTRL) diet. In six-month-old offspring, only IUGR males have increased systolic blood pressure (tail-cuff plethysmography) and microvascular rarefaction (immunofluorescence). ECFCs isolated from bone marrow of IUGR versus CTRL males displayed a decreased proportion of CD31+ versus CD146+ staining on CD45- cells, CD34 expression (flow cytometry, immunofluorescence), reduced proliferation (BrdU incorporation), and an impaired capacity to form capillary-like structures (Matrigel test), associated with an impaired angiogenic profile (immunofluorescence). These dysfunctions were associated with oxidative stress (increased superoxide anion levels (fluorescent dye), decreased superoxide dismutase protein expression, increased DNA damage (immunofluorescence), and stress-induced premature senescence (SIPS; increased beta-galactosidase activity, increased p16INK4a, and decreased sirtuin-1 protein expression). This study demonstrated an impaired functionality of ECFCs at adulthood associated with arterial hypertension in individuals born after IUGR.

Role of Telomeres Shortening in Atherogenesis: An Overview

It is known that the shortening of the telomeres leads to cell senescence, accompanied by acquiring of pro-inflammatory phenotype. The expression of telomerase can elongate telomeres and resist the onset of senescence. The initiation of atherosclerosis is believed to be associated with local senescence of the endothelial cells of the arteries in places with either low or multidirectional oscillatory wall shear stress. The process of regeneration of the artery surface that has begun does not lead to success for several reasons. Atherosclerotic plaques are formed, which, when developed, lead to fatal consequences, which are the leading causes of death in the modern world. The pronounced age dependence of the manifestations of atherosclerosis pushes scientists to try to link the development of atherosclerosis with telomere length. The study of the role of telomere shortening in atherosclerosis is mainly limited to measuring the telomeres of blood cells, and only in rare cases (surgery or post-mortem examination) are the telomeres of local cells available for measurement. The review discusses the basic issues of cellular aging and the interpretation of telomere measurement data in atherosclerosis, as well as the prospects for the prevention and possible treatment of atherosclerosis.

Role of the Wnt pathway in the formation, development, and degeneration of intervertebral discs

Intervertebral disc degeneration (IVDD) is an age-related degenerative disease that is the main cause of low back pain. It seriously affects the quality of life of patients and places a heavy economic burden on families and society. The Wnt pathway plays an important role in the growth, development, and degeneration of intervertebral discs (IVDs). In the embryonic stage, the Wnt pathway participates in the growth and development of IVD by promoting the transformation of progenitor cells into notochord cells and the extension of the notochord. However, the activation of the Wnt pathway after birth promotes IVD cell senescence, apoptosis, and degradation of the extracellular matrix and induces the production of inflammatory factors, thereby accelerating the IVDD process. This article reviews the relationship between the Wnt pathway and IVD, emphasizing its influence on IVD growth, development, and degeneration. Targeting this pathway may become an effective strategy for the treatment of IVDD.

Inhibition of persimmon tannin extract on guinea pig skin pigmentation

BACKGROUND

In daily life, excessive exposure to ultraviolet light can lead to pigmentation.

AIMS

This study is to determine the mechanism of persimmon tannin extract in inhibiting pigmentation, to investigate whether the effect of persimmon tannin extract is superior to that of arbutin, and to detect the optimal concentration.

METHODS

In this study, the guinea pig pigmentation model was established by ultraviolet B (UVB) irradiation. With arbutin as a positive control, Masson-Fontana silver staining was used to observe the effects of persimmon tannin extract on melanin distribution in guinea pigs' skin tissue. Then, the tyrosinase activity was measured, and an Enzyme-linked immunosorbent assay was used to investigate the contents of antioxidant enzymes, inflammatory factors, and signaling pathway inhibitors in guinea pigs' skin tissue.

RESULTS

The results showed that compared with the model group, superoxide dismutase, catalase, glutathione peroxidase, DKK1 content of Wnt/-catenin signaling pathway inhibitors levels, and inhibitory tyrosinase activity were increased by 24.3%, 33.3%, 59.3%, 36.81%, and 17.16%, respectively. Meanwhile, the interleukin-6 and interleukin-8 expression were reduced by approximately 22.2% and 54%. The results also showed that persimmon tannin extract could significantly reduce melanin density. The differences in experimental results were statistically significant (P < .01).

CONCLUSIONS

Compared with the arbutin group, the medium-dose group (persimmon tannin extract of 20%) had a more significant effect on inhibiting pigmentation. Persimmon tannin could serve as a promising agent for preventing skin pigmentation. It is expected to provide ideas for the development of deep-processed persimmon products related to functional foods and cosmetics.

Interleukin-8 Receptors CXCR1 and CXCR2 Are Not Expressed by Endothelial Colony-forming Cells

Endothelial colony-forming cells (ECFCs) are human vasculogenic cells described as potential cell therapy product and good candidates for being a vascular liquid biopsy. Since interleukin-8 (IL-8) is a main actor in senescence, its ability to interact with ECFCs has been explored. However, expression of CXCR1 and CXCR2, the two cellular receptors for IL-8, by ECFCs remain controversial as several teams published contradictory reports. Using complementary technical approaches, we have investigated the presence of these receptors on ECFCs isolated from cord blood. First, CXCR1 and CXCR2 were not detected on several clones of cord blood- endothelial colony-forming cell using different antibodies available, in contrast to well-known positive cells. We then compared the RT-PCR primers used in different papers to search for the presence of CXCR1 and CXCR2 mRNA and found that several primer pairs used could lead to non-specific DNA amplification. Last, we confirmed those results by RNA sequencing. CXCR1 and CXCR2 were not detected in ECFCs in contrary to human-induced pluripotent stem cell-derived endothelial cells (h-iECs). In conclusion, using three different approaches, we confirmed that CXCR1 and CXCR2 were not expressed at mRNA or protein level by ECFCs. Thus, IL-8 secretion by ECFCs, its effects in angiogenesis and their involvement in senescent process need to be reanalyzed according to this absence of CXCR-1 and - 2 in ECFCs.Graphical Abstract.

Oxidative stress enhanced the transforming growth factor-β2-induced epithelial-mesenchymal transition through chemokine ligand 1 on ARPE-19 cell

Fibroblast-like transformation of retinal pigment epithelial (RPE) cells is a pathological feature of proliferative vitreoretinopathy (PVR) that may cause blindness. The effect of oxidative stress alone or together with transforming growth factor-beta 2 (TGF-β2) on epithelial-mesenchymal transformation (EMT) is not fully understood in RPE. TGF-β2 induced the upregulation EMT markers including α-smooth muscle actin (α-SMA), Snail, and Slug and downregulation of E-cadherin (E-cad) in ARPE-19 cells. Hydrogen peroxide (H₂O₂) not only upregulated α-SMA but also enhanced the effect of TGF-β2 on the expression of Snail and Slug. The CXCL family of cytokines could be the mediators of EMT induced by H₂O₂ and TGF-β2. H₂O₂ induced CXCL1, that upregulated α-SMA and fibronectin. Both SB225002, an inhibitor of CXCR2, and antioxidant N-acetylcysteine suppressed the TGF-β2-induced EMT in ARPE-19 cells. Taken together, the results suggest that oxidative stress enhanced TGF-β2-induced EMT through the possible autocrine effect of CXCL1 on CXCR2 in ARPE-19 cells.

Paracrine Interaction of Cancer Stem Cell Populations Is Regulated by the Senescence-Associated Secretory Phenotype (SASP)

Dyskeratosis congenita is a telomere DNA damage syndrome characterized by defective telomere maintenance, bone marrow failure, and increased head and neck cancer risk. The Pot1b^-/-;Terc^+/- mouse exhibits some features of dyskeratosis congenita, but head and neck cancer was not reported in this model. To model the head and neck cancer phenotype, we created unique Pot1b- and p53-null-mutant models which allow genetic lineage tracing of two distinct stem cell populations. Loss of Pot1b expression depleted stem cells via ATR/Chk1/p53 signaling. Tumorigenesis was inhibited in Pot1b^-/-;p53^+/+ mice due to cellular senescence. Pot1b^-/-;p53^-/- tumors also exhibited senescence, but proliferated and metastasized with expansion of Lgr6⁺ stem cells indicative of senescence-associated secretory phenotype. Selective depletion of the small K15⁺ stem cell fraction resulted in reduction of Lgr6⁺ cells and inhibition of tumorigenesis via senescence. Gene expression studies revealed that K15⁺ cancer stem cells regulate Lgr6⁺ cancer stem cell expansion via chemokine signaling. Genetic ablation of the chemokine receptor Cxcr2 inhibited cancer stem cell expansion and tumorigenesis via senescence. The effects of chemokines were primarily mediated by PI3K signaling, which is a therapeutic target in head and neck cancer. IMPLICATIONS: Paracrine interactions of cancer stem cell populations impact therapeutic options and patient outcomes.

Association between polymorphisms in CXCR2 gene and preeclampsia

Background

Preeclampsia is a serious pregnancy‐specific syndrome with incompletely understood pathogenesis. Previous study has demonstrated that the decreased CXCR2 in preeclamptic placentas may contribute to the development of preeclampsia. The role of single nucleotide polymorphisms (SNPs) of CXCR2 gene in the pathogenesis of preeclampsia remains largely unexplored. Thus, we aimed to investigate the association between polymorphisms of CXCR2 gene and preeclampsia in Han Chinese women.

Methods

Totally 481 pregnant women, including 243 controls and 238 patients with preeclampsia were recruited. The rs1126579 and rs2230054 polymorphisms in CXCR2 gene were tested using polymerase chain reaction‐restriction fragment length polymorphism method.

Results

Significantly increased risk of preeclampsia was observed in the rs1126579 CC or TC/CC genotypes when compared with TT genotype (CC vs. TT: odss ratio [OR] = 2.11, 95% confidence interval [CI] = 1.18–3.76, p = 0.039; TC/CC vs. TT: OR = 1.89, 95% CI = 1.29–2.78, p = 0.001). Markedly higher risk of preeclampsia was found to be associated with rs1126579 TC genotype (TC vs. TT/CC: OR = 1.48, 95% CI = 1.04–2.12, p = 0.031). After stratification analysis, the different distribution of TC/CC genotypes was particularly significant in the severe preeclampsia group (OR = 2.15, 95% CI = 1.42–3.24, p < 0.01), the early‐onset severe preeclampsia group (OR = 1.97, 95% CI = 1.14–3.42, p = 0.013), and the late‐onset severe preeclampsia group (OR = 2.29, 95% CI = 1.39–3.78, p < 0.01). Besides, TC genotype carriers had a 1.55 fold increased risk of severe preeclampsia (95% CI = 1.06–2.27, p = 0.022) and a 1.80 fold increased risk of late onset severe preeclampsia (95% CI = 1.14–2.83, p = 0.01) than those of TT/CC genotype carriers.

Conclusions

Our study suggests a genetic association between rs1126579 polymorphism in CXCR2 gene and increased risk of preeclampsia. These data provide a new clue for future investigation.

The p38 pathway, a major pleiotropic cascade that transduces stress and metastatic signals in endothelial cells

By gating the traffic of molecules and cells across the vessel wall, endothelial cells play a central role in regulating cardiovascular functions and systemic homeostasis and in modulating pathophysiological processes such as inflammation and immunity. Accordingly, the loss of endothelial cell integrity is associated with pathological disorders that include atherosclerosis and cancer. The p38 mitogen-activated protein kinase (MAPK) cascades are major signaling pathways that regulate several functions of endothelial cells in response to exogenous and endogenous stimuli including growth factors, stress and cytokines. The p38 MAPK family contains four isoforms p38α, p38β, p38γ and p38δ that are encoded by four different genes. They are all widely expressed although to different levels in almost all human tissues. p38α/MAPK14, that is ubiquitously expressed is the prototype member of the family and is referred here as p38. It regulates the production of inflammatory mediators, and controls cell proliferation, differentiation, migration and survival. Its activation in endothelial cells leads to actin remodeling, angiogenesis, DNA damage response and thereby has major impact on cardiovascular homeostasis, and on cancer progression. In this manuscript, we review the biology of p38 in regulating endothelial functions especially in response to oxidative stress and during the metastatic process.

Ginsenoside Rg3 inhibits the senescence of prostate stromal cells through down-regulation of interleukin 8 expression

Senescent stromal cells support the development of prostate cancer and are considered potential therapeutic targets. This research evaluated the regulatory effects of ginsenoside Rg3 on the senescence of prostatic stromal cells pre-incubated in medium supplemented with 0.5% fetal bovine serum. The results revealed that ginsenoside Rg3 decreased the number of stromal cells positively stained with a senescent cell marker (senescence-associated β-galactosidase). Ginsenoside Rg3 also increased the viability of stromal cells and promoted cell cycle transition from G0/G1 to S phase, as well as inhibited the carcinoma-associated fibroblast-like phenotype in prostate stromal cells, through the up-regulation of smooth muscle cell markers SM22 and smooth muscle myosin heavy chain. Conditioned medium collected from stromal cells treated with ginsenoside Rg3 exhibited an attenuated effect on the promotion of prostate cancer cell migration compared with conditioned medium from stromal cells without Rg3 treatment. Down-regulation of interleukin 8 (IL-8) in a dose- and time-dependent manner was observed in ginsenoside Rg3-treated stromal cells, and over-expression or addition of IL-8 reversed the anti-senescence role of Rg3 in prostate stromal cells. Furthermore, ginsenoside Rg3 down-regulated IL-8 expression by decreasing the reactive oxygen species level in prostatic stromal cells and reducing the transcriptional activity of IL-8 promoter by damping the transcription factors C/EBP β and p65 binding to IL-8 promoter. Our research revealed that ginsenoside Rg3 was able to inhibit prostate stromal cell senescence by down-regulating IL-8 expression. The results suggest a potential value for ginsenoside Rg3 in prostate cancer treatment through the targeting of pro-carcinogenic senescent stromal cells.

Analysis of Serum Cytokines and Single-Nucleotide Polymorphisms of SOD1, SOD2, and CAT in Erysipelas Patients

Increased free radical production had been documented in group A (β-hemolytic) streptococcus infection cases. Comparing 71 erysipelas patients to 55 age-matched healthy individuals, we sought for CAT, SOD1, and SOD2 single polymorphism mutation (SNPs) interactions with erysipelas' predisposition and serum cytokine levels in the acute and recovery phases of erysipelas infection. Whereas female patients had a higher predisposition to erysipelas, male patients were prone to having a facial localization of the infection. The presence of SOD1 G7958, SOD2 T2734, and CAT C262 alleles was linked to erysipelas' predisposition. T and C alleles of SOD2 T2734C individually were linked to patients with bullous and erythematous erysipelas, respectively. G and A alleles of SOD1 G7958A individually were associated with lower limbs and higher body part localizations of the infection, respectively. Serum levels of IL-1β, CCL11, IL-2Rα, CXCL9, TRAIL, PDGF-BB, and CCL4 were associated with symptoms accompanying the infection, while IL-6, IL-9, IL-10, IL-13, IL-15, IL-17, G-CSF, and VEGF were associated with predisposition and recurrence of erysipelas. While variations of IL-1β, IL-7, IL-8, IL-17, CCL5, and HGF were associated with the SOD2 T2734C SNP, variations of PDFG-BB and CCL2 were associated with the CAT C262T SNP.

Epithelial-mesenchymal transition in cancer: Role of the IL-8/IL-8R axis

Epithelial-mesenchymal transition (EMT) is a biological process that is associated with cancer metastasis and invasion. In cancer, EMT promotes cell motility, invasion and distant metastasis. Interleukin (IL)-8 is highly expressed in tumors and may induce EMT. The IL-8/IL-8R axis has a vital role in EMT in carcinoma, which is regulated by several signaling pathways, including the transforming growth factor β-spleen associated tyrosine kinase/Src-AKT/extracellular signal-regulated kinase, p38/Jun N-terminal kinase-activating transcription factor-2, phosphoinositide 3-kinase/AKT, nuclear factor-κB and Wnt signaling pathways. Blocking the IL-8/IL-8R signaling pathway may be a novel strategy to reduce metastasis and improve patient survival rates. This review will cover IL-8-IL-8R signaling pathway in tumor epithelial-mesenchymal transition.

Serum- and Glucocorticoid-Inducible Kinase 1 Delay the Onset of Endothelial Senescence by Directly Interacting with Human Telomerase Reverse Transcriptase

Endothelial senescence is characteristic of vascular aging. Serum- and glucocorticoid-inducible kinase (SGK)1 belongs to a family of serine/threonine kinases regulated by various external stimuli. SGK1 has been shown to be protective against reactive oxygen species (ROS) production and to be involved in processes regulating aging. However, data on the direct relationship between SGK1 and senescence are sparse. In the present study, we sought to investigate the role of SGK1 in cellular aging by using human umbilical vein endothelial cells (HUVECs) infected with different constructs. Senescence was measured at different cellular stages by senescence-associated β-galactosidase (SA-β-gal) activity, human telomerase reverse transcriptase (hTERT) activity, p21 protein levels, and ROS production. HUVECs over-expressing full-length SGK1 (wild-type SGK1 [SGK1WT]) showed a decrease in SA-β-gal and p21 expression and a corresponding increase in hTERT activity in the early stages of aging. Moreover, SGK1WT presented lower levels of ROS production. A direct interaction between SGK1WT and hTERT was also shown by co-immunoprecipitation. The SGK1Δ60 isoform, lacking the amino-terminal 60 amino acids, did not show interaction with hTERT, suggesting a pivotal role of this protein site for the SGK1 anti-aging function. The results from this study may be of particular importance, because SGK1WT over-expression by activating telomerase and reducing ROS levels may delay the processes of endothelial senescence.

Telomerase Therapy to Reverse Cardiovascular Senescence

Cellular senescence of endothelial cells plays an important role in the development of vascular lesions that ultimately lead to an atherosclerotic plaque. This review focuses on the age-related changes of endothelial and vascular smooth muscle cells that contribute to vascular disease and discusses potential new targets that could rejuvenate the vascular system and thereby prevent or delay atherosclerosis.

Senescent endothelial cells: Potential modulators of immunosenescence and ageing

Recent studies have demonstrated that the accumulation of senescent endothelial cells may be the primary cause of cardiovascular diseases. Because of their multifunctional properties, endothelial cells actively take part in stimulating the immune system and inflammation. In addition, ageing is characterized by the progressive deterioration of immune cells and a decline in the activation of the immune response. This results in a loss of the primary function of the immune system, which is eliminating damaged/senescent cells and neutralizing potential sources of harmful inflammatory reactions. In this review, we discuss cellular senescence and the senescence-associated secretory phenotype (SASP) of endothelial cells and summarize the link between endothelial cells and immunosenescence. We describe the possibility that age-related changes in Toll-like receptors (TLRs) and microRNAs can affect the phenotypes of senescent endothelial cells and immune cells via a negative feedback loop aimed at restraining the excessive pro-inflammatory response. This review also addresses the following questions: how do senescent endothelial cells influence ageing or age-related changes in the inflammatory burden; what is the connection between ECs and immunosenescence, and what are the crucial hypothetical pathways linking endothelial cells and the immune system during ageing.

IL-8 induces the epithelial-mesenchymal transition of renal cell carcinoma cells through the activation of AKT signaling

The epithelial-mesenchymal transition (EMT) process has increasingly been examined due to its role in the progression of human tumors. Renal cell carcinoma (RCC) is one of the most common urological tumors that results in patient mortality. Previous studies have demonstrated that the EMT process is closely associated with the metastasis of RCC; however, the underlying molecular mechanism has not been determined yet. The present study revealed that interleukin (IL)-8 was highly expressed in metastatic RCC. IL-8 could induce the EMT of an RCC cell line by enhancing N-cadherin expression and decreasing E-cadherin expression. Furthermore, IL-8 could induce AKT phosphorylation, and the phosphatidylinositol-4,5-bisphosphate 3-kinase inhibitor LY294002 could inhibit the EMT of RCC cells that was induced by IL-8. Therefore, these results suggest that IL-8 is able to promote the EMT of RCC through the activation of the AKT signal transduction pathway, and this may provide a possible molecular mechanism for RCC metastasis.

Relation Between Cellular Senescence and Liver Diseases

Cellular senescence refers to a process that cellular proliferation and differentiation modulated by the multiple stimulating factors gradually decline. Aging cells present the irreversible stop of proliferation and differentiation and change in secretory function because the cell cycle of aging cells is steadily blocked at some point. It has have been shown that cellular senescence plays an important role in the occurrence and development of liver diseases. In this paper, we review the advances in relations between cellular senescence and liver diseases.

The potential for chemical mixtures from the environment to enable the cancer hallmark of sustained proliferative signalling

The aim of this work is to review current knowledge relating the established cancer hallmark, sustained cell proliferation to the existence of chemicals present as low dose mixtures in the environment. Normal cell proliferation is under tight control, i.e. cells respond to a signal to proliferate, and although most cells continue to proliferate into adult life, the multiplication ceases once the stimulatory signal disappears or if the cells are exposed to growth inhibitory signals. Under such circumstances, normal cells remain quiescent until they are stimulated to resume further proliferation. In contrast, tumour cells are unable to halt proliferation, either when subjected to growth inhibitory signals or in the absence of growth stimulatory signals. Environmental chemicals with carcinogenic potential may cause sustained cell proliferation by interfering with some cell proliferation control mechanisms committing cells to an indefinite proliferative span.

Endothelial cell senescence and age-related vascular diseases

Advanced age is an independent risk factor for ageing-related complex diseases, such as coronary artery disease, stroke, and hypertension, which are common but life threatening and related to the ageing-associated vascular dysfunction. On the other hand, patients with progeria syndromes suffer from serious atherosclerosis, suggesting that the impaired vascular functions may be critical to organismal ageing, or vice versa. However, it remains largely unknown how vascular cells, particularly endothelial cell, become senescent and how the senescence impairs the vascular functions and contributes to the age-related vascular diseases over time. Here, we review the recent progress on the characteristics of vascular ageing and endothelial cell senescence in vitro and in vivo, evaluate how genetic and environmental factors as well as autophagy and stem cell influence endothelial cell senescence and how the senescence contributes to the age-related vascular phenotypes, such as atherosclerosis and increased vascular stiffness, and explore the possibility whether we can delay the age-related vascular diseases through the control of vascular ageing.

Expression and effects of epidermal growth factor on human periodontal ligament cells

Repair of damaged periodontal ligament (PDL) tissue is an essential challenge in tooth preservation. Various researchers have attempted to develop efficient therapies for healing and regenerating PDL tissue based on tissue engineering methods focused on targeting signaling molecules in PDL stem cells and other mesenchymal stem cells. In this context, we investigated the expression of epidermal growth factor (EGF) in normal and surgically wounded PDL tissues and its effect on chemotaxis and expression of osteoinductive and angiogenic factors in human PDL cells (HPDLCs). EGF as well as EGF receptor (EGFR) expression was observed in HPDLCs and entire PDL tissue. In a PDL tissue-injured model of rat, EGF and IL-1β were found to be upregulated in a perilesional pattern. Interleukin-1β induced EGF expression in HPDLCs but not EGFR. It also increased transforming growth factor-α (TGF-α) and heparin-binding EGF-like growth factor (HB-EGF) expression. Transwell assays demonstrated the chemotactic activity of EGF on HPDLCs. In addition, EGF treatment significantly induced secretion of bone morphogenetic protein 2 and vascular endothelial growth factor, and gene expression of interleukin-8 (IL-8), and early growth response-1 and -2 (EGR-1/2). Human umbilical vein endothelial cells developed well-formed tube networks when cultured with the supernatant of EGF-treated HPDLCs. These results indicated that EGF upregulated under inflammatory conditions plays roles in the repair of wounded PDL tissue, suggesting its function as a prospective agent to allow the healing and regeneration of this tissue.

Alterations of gene expression and protein synthesis in co-cultured adipose tissue-derived stem cells and squamous cell-carcinoma cells: consequences for clinical applications

Introduction

This is the first study evaluating the interactions of human adipose tissue derived stem cells (ADSCs) and human squamous cell carcinoma cells (SCCs), with regard to a prospective cell-based skin regenerative therapy and a thereby unintended co-localization of ADSCs and SCCs.

Methods

ADSCs were co-cultured with A431-SCCs and primary SCCs (pSCCs) in a transwell system, and cell-cell interactions were analyzed by assessing doubling time, migration and invasion, angiogenesis, quantitative real time PCR of 229 tumor associated genes, and multiplex protein assays of 20 chemokines and growth factors and eight matrix metalloproteinases (MMPS). Results of co-culture were compared to those of the respective mono-culture.

Results

ADSCs’ proliferation on the plate was significantly increased when co-cultured with A431-SCCs (P = 0.038). PSCCs and ADSCs significantly decreased their proliferation in co-culture if cultured on the plate (P <0.001 and P = 0.03). The migration of pSCC was significantly increased in co-culture (P = 0.009), as well as that of ADSCs in A431-SCC-co-culture (P = 0.012). The invasive behavior of pSCCs and A431-SCCs was significantly increased in co-culture by a mean of 33% and 35%, respectively (P = 0.038 and P <0.001). Furthermore, conditioned media from co-cultured ADSC-A431-SCCs and co-cultured ADSCs-pSCCs induced tube formation in an angiogenesis assay in vitro.

In A431-SCC-co-culture 36 genes were up- and 6 were down-regulated in ADSCs, in A431-SCCs 14 genes were up- and 8 genes were down-regulated. In pSCCs-co-culture 36 genes were up-regulated in ADSCs, two were down-regulated, one gene was up-regulated in pSCC, and three genes were down-regulated. Protein expression analysis revealed that three proteins were exclusively produced in co-culture (CXCL9, IL-1b, and MMP-7). In A431-SCC-co-culture the concentration of 17 proteins was significantly increased compared to the ADSCs mono-culture (2.8- to 357-fold), and 15 proteins were expressed more highly (2.8- to 1,527-fold) compared to the A431-SCCs mono-culture. In pSCC-co-culture the concentration of 10 proteins was increased compared to ADSCs-mono-culture (2.5- to 77-fold) and that of 15 proteins was increased compared to pSCC mono-culture (2.6- to 480-fold).

Conclusions

This is the first study evaluating the possible interactions of primary human ADSCs with human SCCs, pointing towards a doubtlessly increased oncological risk, which should not be neglected when considering a clinical use of isolated human ADSCs in skin regenerative therapies.