Search

Pulmonary arterial hypertension (PAH) is a rare and chronic lung vasculature disease characterised by pulmonary vasculature remodelling, including abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) and dysfunctional endothelial cells (ECs). Remodelling of the pulmonary vasculature occurs from maturity to senescence, and it has become apparent that cellular senescence plays a central role in the pathogenesis of various degenerative vascular diseases and pulmonary pathologies. Cellular senescence represents a state of stable proliferative arrest accompanied by the senescence‐associated secretory phenotype (SASP), which entails the copious secretion of proinflammatory signals in the tissue microenvironment. Evidence shows that in PAH patients, higher levels of cytokines, chemokines and inflammatory mediators can be detected and correlate with clinical outcome. Moreover, senescent cells accrue with age in epithelial, endothelial, fibroblastic and immunological compartments within human lungs, and evidence has shown that ECs and PASMCs in lungs from patients with chronic obstructive pulmonary disease were characterised by a higher number of senescent cells. However, there is little evidence uncovering the molecular pulmonary vasculature senescence in PAH. Herein, we review the cellular senescence in pulmonary vascular remodelling, and emphasise its importance in PAH. We further introduce some signalling pathways which might be involved in vasculature senescence and PAH, with the intent to discuss the possibility of the PAH therapy via targeting cellular senescence and reduce PAH progression and mortality. [ABSTRACT FROM AUTHOR]

The age‐related pro‐inflammatory state, discovered and called 'inflammaging' by Franceschi et al. (2000) plays an important role in the pathogenesis of age‐related chronic diseases. A substantial body of data established that inflammaging is accompanied by a '2‐fold to 4‐fold' increase in plasma levels of pro‐inflammatory mediators in healthy elderly people, when compared to the healthy adult population. This review focuses on the pre‐inflammaging phase, here we reported as 'cold‐inflammaging', a state where plasma levels of cytokines are slightly increased, but below the lower limit of 2‐fold increase established for inflammaging. Slightly altered cytokine levels by innate immunity are known to be associated with homeostasis imbalances, this functional pleiotropy of cytokines as signal transducers, have a physiological counterpart, representing an adaptive process aimed at restoring (or achieving a new) homeostatic stability. If a dyshomeostatic state persists, the cytokine response by innate immunity increases and becomes a driver of inflammaging. A scenario where cytokines are characterised as major players in homeostasis imbalances at the beginning (cold‐inflammaging) and then in chronic low‐grade pro‐inflammatory‐state (inflammaging). Other important drivers of inflammaging are cellular senescence with its senescence‐associated secretory phenotype, the altered gut microbiota, and the age‐related dysregulation in the production of endogenous molecular waste (Garb‐aging). The main purpose of this review being to thoroughly investigate each step of the pathway from cold‐inflammaging to overt‐inflammaging, because aging, cold‐inflammaging, overt‐inflammaging and the pathogenesis of age‐related diseases have been shown to share some established basic pillars of geroscience that largely converge on inflammaging. [ABSTRACT FROM AUTHOR]

Particulate matter (PM2.5) and cigarette smoke exposure are leading factors contributing to various diseases, especially respiratory diseases. The purpose of this research was to study the effects of PM2.5 and cigarette smoke on glycerol kinase 5 (GK5) expression and the possible mechanisms by which GK5 participates in lipid droplet (LD) synthesis in alveolar epithelial A549 cells. Real‐time polymerase chain reaction (RT‐PCR) and western blotting have been used for the detection of messenger RNA (mRNA) and protein expression respectively. GK5 overexpressing cells were established by lentivirus transfection, whereby lentiviral vectors deliver the gene into chromosomes, allowing stable expression. Affymetrix microarray analysis, a widely used tool for measuring genome‐wide gene expression, has been used to explore differential gene expression profiles. A549 cells stimulated with PM2.5 and cigarette smoke extract (CSE) showed elevated GK5 expression in a dose‐dependent manner. Transmission electron microscopy and oil red O staining were used to observe LDs in cells. Further, GK5 overexpressing cells showed increased LDs and upregulation of genes and proteins related to lipogenesis and lipid transportation. Affymetrix microarray analysis revealed that GK5 overexpression resulted in the differential expression of more than 109 genes, which were mainly involved in the regulation of cell death, cell survival, cellular movement and migration, and those involved in cellular growth and proliferation pathways. Overall, this study demonstrates that GK5 is upregulated during PM2.5 and cigarette smoke exposure and induces LD synthesis. [ABSTRACT FROM AUTHOR]

Previous studies on the longevity effect of pyrroloquinoline quinine (PQQ) on nematode worms have revealed that PQQ can enhance the antioxidant capacity of nematode worms, thus extending the lifespan of the worms. The induction and development of cellular senescence are closely connected with inflammatory reactions. The aim of this study was to determine the effect of PQQ and ageing factors on senescent cells. To this end, we cultivated human embryonic lung fibroblasts in nutrient solution with or without tumour necrosis factor‐alpha (TNF‐α) to establish an inflammaging model in vitro. The cells were preincubated with or without PQQ to determine if PQQ had any anti‐inflammaging effect. More senescent cells were detected with the addition of TNF‐α than without (P < .01). The ratio of senescent cells to non‐senescent cells in the TNF‐α group was greater than that in the control group (P < .01). When cells were preincubated with PQQ prior to TNF‐α treatment, there were fewer senescent cells than those in the control group, which was not pretreated with PQQ (P < .05). The same tendency was noted with regard to p21, p16, and Jagged1. In summary, we used TNF‐α, a well‐known pro‐inflammatory cytokine associated with inflammaging, to establish an in vitro inflammaging model and provided evidence that PQQ delays TNF‐α –induced cellular senescence and has anti‐inflammaging properties. [ABSTRACT FROM AUTHOR]

Accumulating evidence indicates that abnormal deposition of amyloid-β (Ab) peptide in the brain is responsible for endothelial cell damage and consequently leads to blood-brain barrier (BBB) leakage. However, the mechanisms underlying BBB disruption are not well described. We employed an monolayer BBB model comprising bEnd.3 cell and found that BBB leakage was induced by treatment with Aβ1-42, and the levels of tight junction (TJ) scaffold proteins (ZO-1, Claudin-5, and Occludin) were decreased. Through comparisons of the effects of the different components of Aβ1-42, including monomer (Aβ1-42-Mono), oligomer (Aβ1-42-Oligo), and fibril (Aβ1-42-Fibril), our data confirmed that Aβ1-42-Oligo is likely to be the most important damage factor that results in TJ damage and BBB leakage in Alzheimer's disease. We found that the incubation of bEnd.3 cells with Aβ1-42 significantly up-regulated the level of receptor for advanced glycation end-products (RAGE). Co-incubation of a polyclonal antibody to RAGE and Aβ1-42-Oligo in bEnd.3 cells blocked RAGE suppression of Aβ1-42-Oligo-induced alterations in TJ scaffold proteins and reversed Aβ1-42-Oligoinduced up-regulation of RAGE, matrix metalloproteinase (MMP)-2, and MMP-9. Furthermore, we found that these effects induced by Aβ1-42-Oligo treatment were effectively suppressed by knockdown of RAGE using small interfering RNA (siRNA) transfection. We also found that GM 6001, a broad-spectrum MMP inhibitor, partially reversed the Aβ1-42-Oligo-induced inhibitor effects in bEnd.3 cells. Thus, these results suggested that RAGE played an important role in Abinduced BBB leakage and alterations of TJ scaffold proteins, through a mechanism that involved up-regulation of MMP-2 and MMP-9. [ABSTRACT FROM AUTHOR]