Molecular inflammation as an underlying mechanism of the aging process and age-related diseases

AMPK and HIF signaling pathways regulate both longevity and cancer growth: the good news and the bad news about survival mechanisms

The AMP-activated protein kinase (AMPK) and hypoxia-inducible factor (HIF) signaling pathways are evolutionarily-conserved survival mechanisms responding to two fundamental stresses, energy deficiency and/or oxygen deprivation. The AMPK and HIF pathways regulate the function of a survival network with several transcription factors, e.g. FOXO, NF-κB, NRF2, and p53, as well as with protein kinases and other factors, such as mTOR, ULK1, HDAC5, and SIRT1. Given that AMPK and HIF activation can enhance not only healthspan and lifespan but also cancer growth in a context-dependent manner; it seems that cancer cells can hijack certain survival factors to maintain their growth in harsh conditions. AMPK activation improves energy metabolism, stimulates autophagy, and inhibits inflammation, whereas HIF-1α increases angiogenesis and helps cells to adapt to severe conditions. First we will review how AMPK and HIF signaling mechanisms control the function of an integrated survival network which is able not only to improve the regulation of longevity but also support the progression of tumorigenesis. We will also describe distinct crossroads between the regulation of longevity and cancer, e.g. specific regulation through the AMPKα and HIF-α isoforms, the Warburg effect, mitochondrial dynamics, and cellular senescence.

Calorie restriction as an intervention in ageing

Ageing causes loss of function in tissues and organs, is accompanied by a chronic inflammatory process and affects life- and healthspan. Calorie restriction (CR) is a non-genetic intervention that prevents age-associated diseases and extends longevity in most of the animal models studied so far. CR produces a pleiotropic effect and improves multiple metabolic pathways, generating benefits to the whole organism. Among the effects of CR, modulation of mitochondrial activity and a decrease in oxidative damage are two of the hallmarks. Oxidative damage is reduced by the induction of endogenous antioxidant systems and modulation of the peroxidability index in cell membranes. Mitochondrial activity changes are regulated by inhibition of IGF-1 and Target of Rapamycin (TOR)-dependent activities and activation of AMP-dependent kinase (AMPK) and the sirtuin family of proteins. The activity of PGC-1α and FoxO is regulated by these systems and is involved in mitochondria biogenesis, oxidative metabolism activity and mitochondrial turnover. The use of mimetics and the regulation of common factors have demonstrated that these molecular pathways are essential to explain the effect of CR in the organism. Finally, the anti-inflammatory effect of CR is an interesting emerging factor to be taken into consideration. In the present revision we focus on the general effect of CR and other mimetics in longevity, focusing especially on the cardiovascular system and skeletal muscle.

Immune system transcriptome in gingival tissues of young nonhuman primates

BACKGROUND AND OBJECTIVE

Young/adolescent humans harbor many microorganisms associated with periodontal disease in adults and show substantial gingival inflammatory responses. However, younger individuals do not demonstrate the soft- and hard-tissue destruction that hallmark periodontitis.

MATERIAL AND METHODS

This study evaluated responses to the oral microbial ecology in gingival tissues from clinically healthy young Macaca mulatta (< 3 years of age) compared with older animals (5-23 years of age). RNA was isolated from the tissues and analyzed for the transcriptome using the Rhesus Macaque GeneChip (Affymetrix).

RESULTS

Global transcriptional profiling of four age groups revealed a subset of 159 genes that were differentially expressed across at least one of the age comparisons. Correlation metrics generated a relevance network abstraction of these genes. Partitioning of the relevance network revealed seven distinct communities comprising functionally related genes associated with host inflammatory and immune responses. A group of genes was identified that were selectively increased/decreased or positively/negatively correlated with gingival profiles in the animals. A principal components analysis created metagenes of expression profiles for classifying the 23 animals.

CONCLUSION

The results provide novel system-level insights into gene-expression differences in gingival tissues from healthy young animals, weighted toward host responses associated with anti-inflammatory biomolecules or those linked with T-cell regulation of responses. The combination of the regulated microenvironment may help to explain the apparent 'resistance' of younger individuals to developing periodontal disease.

Arginine Relieves the Inflammatory Response and Enhances the Casein Expression in Bovine Mammary Epithelial Cells Induced by Lipopolysaccharide

As one of functional active amino acids, L-arginine holds a key position in immunity. However, the mechanism that arginine modulates cow mammary inflammatory response in ruminant is unclear. Therefore, this study was conducted to investigate the effects of L-arginine on inflammatory response and casein expression after challenging the bovine mammary epithelial cells (BMECs) with lipopolysaccharide (LPS). The cells were divided into four groups, stimulated with or without LPS (10 μg/mL) and treated with or without arginine (100 μg/mL) for 12 h. The concentration of proinflammatory cytokines, inducible nitric oxide synthase (iNOS), mammalian target of rapamycin (mTOR), and Toll-like receptor 4 (TLR4) signaling pathways as well as the casein was determined. The results showed that arginine reduced the LPS-induced production like IL-1β, IL-6, TNF-α, and iNOS. Though the expression of NF-κB was attenuated and the mTOR signaling pathway was upregulated, arginine had no effect on TLR4 expression. In addition, our results show that the content of β-casein and the total casein were enhanced after arginine was supplemented in LPS-induced BMECs. In conclusion, arginine could relieve the inflammatory reaction induced by LPS and enhance the concentration of β-casein and the total casein in bovine mammary epithelial cells.

Developing pathways for oral care in elders: challenges in care for the dentate the subject?

OBJECTIVE

This paper reviews potential age-associated risk factors for satisfactory oral function and oral disease to inform the development of care pathways for the older person.

BACKGROUND

Alterations in dental status or both physical and biological change associated with age can impact on oral disease and oral function.

MATERIALS AND METHODS

Older people tend to have fewer teeth and some are edentulous. Physical and biological changes in bodily function with age can also affect oral health care either directly or indirectly.

RESULTS

Reductions in chewing ability impact on the foods people choose to eat because of perceived difficulty with chewing, with a potentially deleterious affect on dietary quality. This is worse in people with xerostomia where chewing and swallowing are impaired anyway. Change in the cell-mediated inflammatory response impacts on gingival and periodontal disease manifestation and progression. Sarcopenia makes the physical act of toothbrushing more challenging. Caries remains a clinical problem that affects both the crowns and the roots of teeth. Coronal lesions tend to be around existing restorations where there is no evidence base about care/prevention.

CONCLUSION

The physical and clinical changes that occur with ageing require an altered pattern of care for older people which is adjusted to their disease risk and encourage diversity of foods consumption.

Psychological stress-induced catecholamines accelerates cutaneous aging in mice

Psychological stress may be an important extrinsic factor which influences aging process. However, neither study demonstrated the mechanism by which chronic stress participates in skin aging. Aim of this study was to investigate the effects of chronic psychological stress on mice skin. Mice were daily submitted to rotational stress, for 28 days, until euthanasia. After 28 days, mice were killed and normal skin was analyzed. Macroscopically, dorsum skin of chronically stressed mice presented more wrinkled when compared to that of nonstressed mice. In mice skin, chronic stress increased lipid peroxidation, carbonyl protein content, nitrotyrosine levels, neutrophil infiltration, neutrophil elastase, tissue inhibitor of metalloproteinase-1 and metalloproteinase-8 levels. Nevertheless, chronic stress reduced dermis thickness, collagen type I, fibrilin-1 and elastin protein levels in mice skin. In in vitro assays, murine skin fibroblasts were exposed to elevated epinephrine levels plus inhibitors of reactive oxygen species (ROS) and reactive nitrogen species (RNS), fibroblast activity was evaluated in a short time. In skin fibroblast culture, treatment with inhibitors of ROS and RNS synthesis abolished the increase in carbonyl protein content and lipid peroxide accumulation induced by epinephrine. In conclusion, chronic psychological stress may be an important extrinsic factor, which contributes to skin aging in mice.

[Association between carbonyl proteins and tumor necrosis factor alpha with muscle strength in young and older women: exploratory study]

INTRODUCTION

It has recently been proposed that there is a close relationship between oxidative stress and low-grade chronic inflammation. Both processes have been related separately to muscle function in older adults (OA). Nevertheless, it still has not been determined if this relationship is present particularly in OA. The objective of this study was to determine the relationship between the plasma levels of TNF-α and carbonyl proteins (CP) and muscle strength in a group of young and older women.

METHODS

An exploratory study was conducted on 13 older and 8 young women, in whom the plasma levels of CP and TNF-α were measured. Muscle strength was measured by handgrip test, quadriceps voluntary maximal isometric strength, arm curl, and the 30 second sit to stand test.

RESULTS

There were no differences in the plasma levels of CP and TNF-α between the groups, but there was relationship between the biomarkers only in the OA group. A non-linear relationship was observed between CP and quadriceps voluntary maximal isometric strength only in the OA group (R(2)=36.2; P=.038). For TNF-α there were no significant association with any of the applied tests.

CONCLUSIONS

There is an association between CP and quadriceps voluntary maximal isometric strength only in the OA group, which could indicate a deleterious action of oxidative stress on muscle function, particularly in aging.

DAMPs and influenza virus infection in ageing

Influenza A virus (IAV) is a serious global health problem worldwide due to frequent and severe outbreaks. IAV causes significant morbidity and mortality in the elderly population, due to the ineffectiveness of the vaccine and the alteration of T cell immunity with ageing. The cellular and molecular link between ageing and virus infection is unclear and it is possible that damage associated molecular patterns (DAMPs) may play a role in the raised severity and susceptibility of virus infections in the elderly. DAMPs which are released from damaged cells following activation, injury or cell death can activate the immune response through the stimulation of the inflammasome through several types of receptors found on the plasma membrane, inside endosomes after endocytosis as well as in the cytosol. In this review, the detriment in the immune system during ageing and the links between influenza virus infection and ageing will be discussed. In addition, the role of DAMPs such as HMGB1 and S100/Annexin in ageing, and the enhanced morbidity and mortality to severe influenza infection in ageing will be highlighted.

Lipoxin A4 and Neutrophil/Lymphocyte Ratio: A Possible Indicator in Achieved Systemic Risk Factors for Periodontitis

Background

The aim of this study was to evaluate the serum lipoxin A₄ (LXA₄) and neutrophil/lymphocyte (Ne/Ly) ratio in individuals with achieved systemic risk factors for periodontitis.

Material/Methods

One hundred and eighty volunteers (69 male, 111 female) who were categorized as systemically healthy control, diabetes, hyperlipidemia, obese and menopause were recruited for this cross-sectional study. Sociodemographic characteristics and oral health behaviors were recorded via questionnaire. Clinical periodontal parameters, including plaque index (PI), gingival index (GI), probing pocket depth (PD), clinical attachment level (CAL), sulcus bleeding index (SBI) and decayed, missing, and filled teeth index (DMFT), were assessed. Systemic parameters and LXA₄ levels were evaluated in serum samples.

Results

Clinical periodontal parameters and DMFT were higher in subjects with achieved systemic risk factors than in healthy subjects. The systemically healthy with periodontitis group had higher serum LXA₄ levels than the systemically healthy with non-periodontitis group (P<0.05). The Ne/Ly ratio was higher in the hyperlipidemic group with periodontitis than in the hyperlipidemic group with non-periodontitis (P<0.05). In the control group, serum LXA₄ levels were positively correlated with the PD, CAL and SBI.

Conclusions

In the presence of periodontitis, an increase in LXA₄ levels and the Ne/Ly ratio in hyperlipidemic patients could contribute to the hypothesis that these parameters could be an indicator in periodontitis and its systemic risk factors.

Effects of MHY908, a New Synthetic PPARα/γ Dual Agonist, on Inflammatory Responses and Insulin Resistance in Aged Rats

Insulin resistance is common with aging and is associated with the inflammatory response in both humans and rodents. A number of peroxisome proliferator-activated receptor (PPAR) α/γ dual agonists have been tested for their abilities to attenuate insulin resistance and type 2 diabetes. However, there is no study on the effects of PPARα/γ dual agonists on inflammation and insulin resistance during aging. In the present study, we investigated the ability of 2-[4-(5-chlorobenzothiazothiazol-2-yl)phenoxy]-2-methyl-propionic acid (MHY908), a newly synthesized novel PPARα/γ dual agonist, to suppress the inflammatory response and attenuate insulin resistance in aged rats. Twenty-month-old rats were divided into four groups: ad libitum fed, ad libitum fed supplemented with MHY908 (1 mg and 3 mg/kg/day for 4 weeks), and 40% calorie restricted. Six-month-old ad libitum fed rats were used as an age control. The aged rats supplemented with MHY908 showed reduced serum glucose, triglyceride, and insulin levels, as well as reduced liver triglyceride levels. MHY908 brought about a reduction in endoplasmic reticulum stress and activation of the c-Jun N-terminal kinase in the livers of aged rats, which consequently improved insulin signaling. In the kidneys of aged rats, the efficacy of MHY908 as a potent anti-inflammatory agent was shown by its suppression of NF-κB activation through inhibition of the Akt/IκB kinase signaling pathway. Therefore, the major finding of this study is that MHY908 acts as a therapeutic agent against age-related inflammation associated with insulin resistance by activating PPARα and PPARγ, thus attenuating endoplasmic reticulum stress.

Ginseng berry extract supplementation improves age-related decline of insulin signaling in mice

The aim of this study was to evaluate the effects of ginseng berry extract on insulin sensitivity and associated molecular mechanisms in aged mice. C57BL/6 mice (15 months old) were maintained on a regular diet (CON) or a regular diet supplemented with 0.05% ginseng berry extract (GBD) for 24 or 32 weeks. GBD-fed mice showed significantly lower serum insulin levels (p = 0.016) and insulin resistance scores (HOMA-IR) (p = 0.012), suggesting that GBD improved insulin sensitivity. Pancreatic islet hypertrophy was also ameliorated in GBD-fed mice (p = 0.007). Protein levels of tyrosine phosphorylated insulin receptor substrate (IRS)-1 (p = 0.047), and protein kinase B (AKT) (p = 0.037), were up-regulated in the muscle of insulin-injected GBD-fed mice compared with CON-fed mice. The expressions of forkhead box protein O1 (FOXO1) (p = 0.036) and peroxisome proliferator-activated receptor gamma (PPARγ) (p = 0.032), which are known as aging- and insulin resistance-related genes, were also increased in the muscle of GBD-fed mice. We conclude that ginseng berry extract consumption might increase activation of IRS-1 and AKT, contributing to the improvement of insulin sensitivity in aged mice.

Profiling age-related epigenetic markers of stomach adenocarcinoma in young and old subjects

The purpose of our study is to identify epigenetic markers that are differently expressed in the stomach adenocarcinoma (STAD) condition. Based on data from The Cancer Genome Atlas (TCGA), we were able to detect an age-related difference in methylation patterns and changes in gene and miRNA expression levels in young (n = 14) and old (n = 70) STAD subjects. Our analysis identified 323 upregulated and 653 downregulated genes in old STAD subjects. We also found 76 miRNAs with age-related expression patterns and 113 differentially methylated genes (DMGs), respectively. Our further analysis revealed that significant upregulated genes (n = 35) were assigned to the cell cycle, while the muscle system process (n = 27) and cell adhesion-related genes (n = 57) were downregulated. In addition, by comparing gene and miRNA expression with methylation change, we identified that three upregulated genes (ELF3, IL1β, and MMP13) known to be involved in inflammatory responses and cell growth were significantly hypomethylated in the promoter region. We further detected target candidates for age-related, downregulated miRNAs (hsa-mir-124–3, hsa-mir-204, and hsa-mir-125b-2) in old STAD subjects. This is the first report of the results from a study exploring age-related epigenetic biomarkers of STAD using high-throughput data and provides evidence for a complex clinicopathological condition expressed by the age-related STAD progression.

The probiotic mixture IRT5 ameliorates age-dependent colitis in rats

To investigate the anti-inflammatory effect of probiotics, we orally administered IRT5 (1×10(9)CFU/rat) for 8 weeks to aged (16 months-old) Fischer 344 rats, and measured parameters of colitis. The expression levels of the inflammatory markers' inducible NO synthase (iNOS), cyclooxygenase-2 (COX2), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were higher in the colons of normal aged rats (18 months-old) than in the colons of normal young rats (6 months-old). Treatment with IRT5 suppressed the age-associated increased expression of iNOS, COX2, TNF-α, and IL-1β, and activation of NF-κB and mitogen-activated protein kinases. In a similar manner, the expression of tight junction proteins in the colon of normal aged rats was suppressed more potently than in normal young rats, and treatment of aged rats with IRT5 decreased the age-dependent suppression of tight junction proteins ZO-1, occludin, and claudin-1. Treatment with IRT5 suppressed age-associated increases in expressions of senescence markers p16 and p53 in the colon of aged rats, but increased age-suppressed expression of SIRT1. However, treatment with IRT5 inhibited age-associated increased myeloperoxidase activity in the colon. In addition, treatment with IRT5 lowered the levels of LPS in intestinal fluid and blood of aged rats, as well as the reduced concentrations of reactive oxygen species, malondialdehyde, and C-reactive protein in the blood. These findings suggest that IRT5 treatment may suppress age-dependent colitis by inhibiting gut microbiota LPS production.

PPARγ Maintains Homeostasis through Autophagy Regulation in Dental Pulp

This study investigated the relevance between pulp vitality and autophagy in aged human dental pulp cells (HDPCs) and whether peroxisome proliferator-activated receptor gamma (PPARγ) affects autophagy regulation for homeostasis in the aging progress. In vivo experiments were used in human and Sprague-Dawley rat teeth obtained from young and adult individuals. Aging- and autophagy-related molecules were determined by immunohistochemistry and hematoxylin and eosin staining. HDPCs were serially subcultured until spontaneously arrested for in vitro aging, and the replication deficiency adenovirus was introduced for PPARγ overexpression. Subsequently, the effect of PPARγ on regulation of autophagy molecules, mitochondria activity, and cell viability was assessed using Western blotting, confocal microscopy, and the MTT assay, respectively. In adult pulp tissue, autophagy molecules (autophagy protein 5, microtubule-associated protein 1A/1B light chain, and Beclin-1) were increased, but aging-related (PPARγ and heme oxygenase 1 [HO-1]) and dentinogenesis (dentin sialophosphoprotein and dentin matrix acidic phosphoprotein) molecules were decreased. In aged HDPCs, autophagy and intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 were increased, while PPARγ and HO-1 were decreased. Under stimulation with lipopolysaccharide, autophagy- and aging-related molecules were differentially expressed between young and aged cells. PPARγ induced HO-1 and autophagy molecules but reduced inflammatory molecules in aged cells. In addition, PPARγ activated strong mitochondrial activity and cell viability in aging cells. Inhibition of HO-1 by tin protoporphyrin IX exacerbated autophagy and mitochondrial activity as well as cell viability in young cells. This study indicates that PPARγ maintains pulp homeostasis through the regulation of autophagy molecules during the life span of HDPCs.

Gingival wound healing: an essential response disturbed by aging?

Gingival wound healing comprises a series of sequential responses that allow the closure of breaches in the masticatory mucosa. This process is of critical importance to prevent the invasion of microbes or other agents into tissues, avoiding the establishment of a chronic infection. Wound healing may also play an important role during cell and tissue reaction to long-term injury, as it may occur during inflammatory responses and cancer. Recent experimental data have shown that gingival wound healing is severely affected by the aging process. These defects may alter distinct phases of the wound-healing process, including epithelial migration, granulation tissue formation, and tissue remodeling. The cellular and molecular defects that may explain these deficiencies include several biological responses such as an increased inflammatory response, altered integrin signaling, reduced growth factor activity, decreased cell proliferation, diminished angiogenesis, reduced collagen synthesis, augmented collagen remodeling, and deterioration of the proliferative and differentiation potential of stem cells. In this review, we explore the cellular and molecular basis of these defects and their possible clinical implications.

Orally administrated Lactobacillus pentosus var. plantarum C29 ameliorates age-dependent colitis by inhibiting the nuclear factor-kappa B signaling pathway via the regulation of lipopolysaccharide production by gut microbiota

To evaluate the anti-inflammaging effect of lactic acid bacteria (LAB) on age-dependent inflammation, we first screened and selected a tumor necrosis factor (TNF)-α and reactive oxygen species (ROS)-inhibitory LAB, Lactobacillus pentosus var. plantarum C29, among the LABs isolated from fermented vegetables using LPS-stimulated mouse peritoneal macrophages. Oral administration of C29 (2 × 109 CFU/rat) for 8 weeks in aged Fischer 344 rats (age, 16 months) inhibited the expression of the inflammatory markers myeloperoxidase, inducible nitric oxide (NO) synthase, cyclooxygenase-2, pro-inflammatory cytokines tumor necrosis factor (TNF)-α and IL-6 and the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), activator protein 1 (AP1), and mitogen-activated protein kinases (MAPKs). Treatment with C29 induced the expression of tight junction proteins ZO-1, occludin, and claudin-1, and reduced intestinal microbial LPS and plasmatic LPS levels and ROS, as well as the Firmicutes to Bacteroidetes ratio, which is significantly higher in aged rats than in young rats. C29 treatment also reduced plasmatic reactive oxygen species, malondialdehyde, C-reactive protein, and TNF-α, and suppressed expression of senescence markers p16 and p53 in the colon of the aged rats, but increased SIRT 1 expression. Based on these findings, we concluded that C29 treatment may suppress aging-dependent colitis by inhibiting NF-κB, AP1, and MAPK activation via the inhibition of gut microbiota LPS production and the induction of tight junction protein expression.

Anti-inflammatory effect of resveratrol in old mice liver

Inflammation is a hallmark of aging. Caloric restriction and resveratrol (RSV) have shown important effects on prevention of oxidative stress and inflammation. Here, we investigate the progression of proinflammatory markers in liver during aging and the effect of RSV on inflammation markers in the liver of old male C57BL/6J mice. Young (2 months), mature (12 months) and old (18 months) mice were fed during 6 months with RSV. Levels of IL-1β, IL-6, IL-10, IL-17 and TNF-α were evaluated by ELISA in mice liver. Levels of pro-inflammatory cytokines, IL-1β, IL-6, IL-17 and TNF-α and also their respective mRNA increased in the liver from old mice. However, RSV decreased these levels in the case of IL-1β and TNF-α but only in old mice showing no effect on young and mature animals. This reduction was also found at the mRNA level. Levels of mRNA of the components of NALP-3 inflammasome, ASC, CASP-1, NALP-1 and NALP-3, also showed an age-dependent increase that was reversed by RSV. Furthermore, cyclooxygenase 2 levels, a marker of proinflammatory innate immune activity, were also upregulated in aged liver and reversed again by RSV. In conclusion, our study confirms that aging is accompanied by an increase in the proinflammatory pattern in the liver and that RSV reduces this pattern in old mice liver.

Granzyme B mediates both direct and indirect cleavage of extracellular matrix in skin after chronic low-dose ultraviolet light irradiation

Extracellular matrix (ECM) degradation is a hallmark of many chronic inflammatory diseases that can lead to a loss of function, aging, and disease progression. Ultraviolet light (UV) irradiation from the sun is widely considered as the major cause of visible human skin aging, causing increased inflammation and enhanced ECM degradation. Granzyme B (GzmB), a serine protease that is expressed by a variety of cells, accumulates in the extracellular milieu during chronic inflammation and cleaves a number of ECM proteins. We hypothesized that GzmB contributes to ECM degradation in the skin after UV irradiation through both direct cleavage of ECM proteins and indirectly through the induction of other proteinases. Wild-type and GzmB-knockout mice were repeatedly exposed to minimal erythemal doses of solar-simulated UV irradiation for 20 weeks. GzmB expression was significantly increased in wild-type treated skin compared to nonirradiated controls, colocalizing to keratinocytes and to an increased mast cell population. GzmB deficiency significantly protected against the formation of wrinkles and the loss of dermal collagen density, which was related to the cleavage of decorin, an abundant proteoglycan involved in collagen fibrillogenesis and integrity. GzmB also cleaved fibronectin, and GzmB-mediated fibronectin fragments increased the expression of collagen-degrading matrix metalloproteinase-1 (MMP-1) in fibroblasts. Collectively, these findings indicate a significant role for GzmB in ECM degradation that may have implications in many age-related chronic inflammatory diseases.

The Intricate Interplay between Mechanisms Underlying Aging and Cancer

Age is the major risk factor in the incidence of cancer, a hyperplastic disease associated with aging. Here, we discuss the complex interplay between mechanisms underlying aging and cancer as a reciprocal relationship. This relationship progresses with organismal age, follows the history of cell proliferation and senescence, is driven by common or antagonistic causes underlying aging and cancer in an age-dependent fashion, and is maintained via age-related convergent and divergent mechanisms. We summarize our knowledge of these mechanisms, outline the most important unanswered questions and suggest directions for future research.

Plasma/Serum Plasmalogens: Methods of Analysis and Clinical Significance

Age-related diseases, such as atherosclerosis and dementia, are associated with oxidative stress and chronic inflammation. Peroxisome dysfunction may be related to aging and age-related pathologies, possibly through the derangement of redox homeostasis. The biosyntheses of plasmalogens (Pls), a subclass of glycerophospholipids, are primarily regulated by peroxisomes. Thus, plasma Pls may reflect the systemic functional activity of peroxisomes and serve as potential biomarkers for diseases related to oxidative stress and aging. Recently, we have established three promising analytical methods for plasma/serum Pls using high-performance liquid chromatography with radioactive iodine, liquid chromatography-tandem mass spectrometry, and enzymatic assay. These methods were validated and used to obtain detailed molecular information regarding these molecules. In cross-sectional studies on asymptomatic, coronary artery disease, and elderly dementia individuals, we found that serum choline Pls, particularly those containing oleic and linoleic acid in the sn-2 position of the glycerol backbone, may serve as reliable antiatherogenic biomarkers. Furthermore, we also found that serum ethanolamine Pls were effective in discriminating cognitive impairment. These results support our hypothesis and further studies are clearly needed to elucidate Pls pathophysiologic significance.

Sarcopenia: Monitoring, Molecular Mechanisms, and Physical Intervention

According to European Working Group on Sarcopenia in Older People (EWGSOP) sarcopenia includes both a loss of muscle strength and a decline in functional quality in addition to the loss of muscle protein mass. In order to develop strategies to prevent and treat sarcopenia, the risk factors and causes of sarcopenia must be identified. Age-related muscle loss is characterized by the contribution of multiple factors, and there is growing evidence for a prominent role of low-grade chronic inflammation in sarcopenia. The elderly who are less physically active are more likely to have lower skeletal muscle mass and strength and are at increased risk of developing sarcopenia. Resistance training added to aerobic exercise or high-intensity interval training promote numerous changes in skeletal muscle, many of which may help to prevent or reverse sarcopenia. In this review, we provided current information on definition and monitoring, molecular mechanisms, and physical intervention to counteract sarcopenia.

Age-related inflammation and insulin resistance: a review of their intricate interdependency

Chronic inflammation is a major risk factor underlying aging and the associated diseases of aging; of particular interest is insulin resistance during aging. Chronic inflammation impairs normal lipid accumulation, adipose tissue function, mitochondrial function, and causes endoplasmic reticulum (ER) stress, which lead to insulin resistance. However, some studies show that insulin resistance itself amplifies chronic inflammation. The activity of the insulin-dependent Akt signaling pathway is highlighted because of its decrease in insulin-sensitive organs, like liver and muscle, which may underlie insulin resistance and hyperinsulinemia, and its increased levels in non-metabolic organs, such as kidney and aorta. In that the prevalence of obesity has increased substantially for all age groups in recent years, our review summarizes the data showing the involvement of chronic inflammation in obesity-induced insulin resistance, which perpetuates reciprocal interactions between the chronic inflammatory process and increased adiposity, thereby accelerating the aging process.

The roles of FoxOs in modulation of aging by calorie restriction

FoxO activity and modifications, such as its phosphorylation, acetylation, and methylation, may help drive the expression of genes involved in combating oxidative stress by causing the epigenetic modifications, and thus, preserve cellular function during aging and age-related diseases, such as diabetes, cancer, and Alzheimer disease. Insulin signaling has been postulated to influence the aging process by increasing resistance to oxidative stress, and slowing the accumulation of oxidative damage. Some antioxidative effects are mediated by a conserved family of forkhead box transcription factors (FoxOs), which in the absence of insulin signaling freely bind to promoters of antioxidant enzymes, superoxide dismutase, and catalase. On the other hand, calorie restriction (CR) extends the lifespans of several species via the insulin pathway, and extends longevity and healthspan in diverse species via a conserved mechanism. CR enhances adaptive stress responses at the cellular and organism levels and extends lifespan in a FoxO-independent manner. Thus, increased modification of FoxO is modulated via the hyperinsulinemia-induced PI3K/Akt pathway during aging, and CR reverses this process. Accordingly, FoxO plays an important role in maintenance of metabolic homeostasis and removal of oxidative stress in the aging process and in the effect of CR on lifespan.

Daumone fed late in life improves survival and reduces hepatic inflammation and fibrosis in mice

The liver is one of the most susceptible organs to aging, and hepatic inflammation and fibrosis increase with age. Chronic inflammation has been proposed as the major molecular mechanism underlying aging and age-related diseases, whereas calorie restriction has been shown to be the most effective in extending mammalian lifespan and to have anti-aging effects through its anti-inflammatory action. Thus, it is necessary to develop effective calorie restriction mimetics. Daumone [(2)-(6R)-(3,5-dihydroxy-6-methyltetrahydropyran-2-yloxy)heptanoic acid], a pheromone secreted by Caenorhabditis elegans, forces them to enter the dauer stage when facing inadequate conditions. Because Caenorhabditis elegans live longer during the dauer stage under energy deprivation, it was hypothesized that daumone may improve survival in mammals by mimicking calorie restriction. Daumone (2 mg kg(-1) day(-1) ) was administered orally for 5 months to 24-month-old male C57BL/6J mice. Daumone was found to reduce the risk of death by 48% compared with age-matched control mice, and the increased plasma insulin normally presented in old mice was significantly reduced by daumone. The increased hepatic hypertrophy, senescence-associated β-galactosidase activity, insulin resistance, lipid accumulation, inflammation, oxidative stress, and fibrosis in old mice were significantly attenuated by daumone. From a mechanistic view, daumone reduced the phosphorylation of the IκBα and upregulation of Rela and Nfkbia mRNA in the livers of old mice. The anti-inflammatory effect of daumone was confirmed in lipopolysaccharide-induced liver injury model. Oral administration of daumone improves survival in mice and delivers anti-aging effects to the aged liver by modulating chronic inflammation, indicating that daumone could be developed as an anti-aging compound.

Effect of procysteine on aging-associated changes in hepatic GSH and SMase: evidence for transcriptional regulation of smpd3

In hepatocytes, aging-associated decline in GSH has been linked to activation of neutral SMase (nSMase), accumulation of bioactive ceramide, and inflammation. In this study, we seek to test whether dietary supplementation with the cysteine precursor, L-2-oxothiazolidine-4-carboxylic acid (OTC), would correct the aging-associated differences in hepatic GSH, nSMase, and ceramide. Young and aged mice were placed on a diet that either lacked sulfur-containing amino acids (SAAs) or had 0.5% OTC for 4 weeks. Mice fed standard chow were used as an additional control. SAA-deficient mice exhibited significant aging-associated differences in hepatic GSH, GSH/GSSG, ceramide, and nSMase. C24:1 ceramide, the major ceramide species in liver, was affected the most by aging, followed by the less abundant C16:0 ceramide. OTC supplementation eliminated the aging-associated differences in hepatic GSH and GSH/GSSG ratio. Surprisingly, however, instead of decreasing, the nSMase activity and ceramide increased in the OTC-fed mice irrespective of their age. These effects were due to elevated nSMase-2 mRNA and protein and appeared to be direct. Similar increases were seen in HepG2 cells following treatment with OTC. The OTC-fed aged mice also exhibited hepatic steatosis and triacylglyceride accumulation. These results suggest that OTC is a potent stimulant of nSMase-2 expression and that there may be unanticipated complications of OTC supplementation.

The essential role of FoxO6 phosphorylation in aging and calorie restriction

Changes in the activities of FoxOs caused by phosphorylation, acetylation, or ubiquitination induce expressional changes in the genes involved in the modulation of oxidative stress by modifying histones and chromatins and can substantially alter cellular functions during aging and age-related diseases. However, the precise role that FoxO6, a novel member of the FoxO class of transcription factors, plays in the aging kidney has not been determined. The purpose of this study was to determine the role played by FoxO6 in the maintenance of redox homeostasis in HEK293T cells and aged kidney tissues isolated from ad libitum (AL)-fed and 40 % calorie restriction (CR) rats. The results obtained from AL-fed rats showed that diminished FoxO6 activity during aging was caused by FoxO6 phosphorylation, which disabled its transcriptional activity. In contrast, CR rats were found to have significantly higher FoxO6 activities and maintained redox balance. To determine the molecular mechanism responsible for FoxO6 modification by age-related oxidative stress, we examined H2O2-treated HEK293T cells in which FoxO6 was inactivated by phosphorylation and found that H2O2-induced oxidative stress promoted FoxO6 phosphorylation via PI3K/Akt signaling. The results of this study show that the protective role of FoxO6 in the aging process may in part be related to its ability to attenuate oxidative stress by upregulating catalase expression, as shown in CR. This delineation of the role of FoxO6 expands understanding of the pathological and physiological mechanisms of aging.

Chinese Prescription Kangen-karyu and Salviae Miltiorrhizae Radix Improve Age-Related Oxidative Stress and Inflammatory Response through the PI3K/Akt or MAPK Pathways

This study examined whether Kangen-karyu and its crude drug, Salviae Miltiorrhizae Radix, have a reno-protective effect on the age-related oxidative stress and inflammatory response through the phosphoinositide 3-kinase (PI3K)/Akt or mitogen-activated protein kinase (MAPK) pathways in aged rats. Kangen-karyu or Salviae Miltiorrhizae Radix (20 mg/kg body weight/day) was administered orally to old groups of rats for 16 days, and their effects were compared with the vehicle-treated old and young rats. The administration of Kangen-karyu caused a slight decrease in the serum glucose level and a significant decrease in the serum insulin level in the old rats. The increased levels of serum renal functional parameter (urea-nitrogen) and oxidative parameter were significantly reduced by both Kangen-karyu and Salviae Miltiorrhizae Radix. The old rats exhibited a dysregulation of the protein expression related to insulin resistance, oxidative stress, and inflammation in the kidneys, but Kangen-karyu administration significantly reduced the expression of the inflammatory proteins through the PI3K/Akt pathway. On the other hand, the Salviae Miltiorrhizae Radix-treated old rats showed a decrease in the inflammatory cytokines through the MAPK pathway. These results provide important evidence that Kangen-karyu and Salviae Miltiorrhizae Radix have a pleiotropic effect on the PI3K/Akt and MAPK pathways, showing renoprotective effects against the development of inflammation in old rats. This study provides scientific evidence that Kangen-karyu and Salviae Miltiorrhizae Radix improve the inflammatory responses via the PI3K/Akt or MAPK pathways in the kidney of old rats.

Anti-inflammation effect of Exercise and Korean red ginseng in aging model rats with diet-induced atherosclerosis

BACKGROUND/OBJECTIVES

The aim of this study was to investigate the effects of exercise (EX) and Korean red ginseng (KRG) on inflammation mechanism in aging model rats with diet-induced atherosclerosis.

MATERIALS/METHODS

Forty-eight male Sprague-Dawley rats were divided into 6 groups: Young control (Y-C), Aging control (A-C), A-C with HFD (AHF), AHF with EX (AHF-EX), AHF-EX with KRG (AHF-EX+RG), and AHF with KRG (AHF-RG). Aging was induced by D-gal (100mg/kg) and atherosclerosis was induced by HFD (60% fat) for 9 weeks. The experimental rats were performed swimming (60 min/day, 5 days/week) and supplied KRG orally (dose of 200 mg/kg) for 8 weeks. All rat aorta samples were harvested for biochemical and immunohistochemical analyses.

REULTS

The EX and KRG supplementation significantly inhibited body weight and levels of TC, TG, LDL-C, and enhance of HDL-C compared with untreated AHF groups. AHF-EX, AHF-EX+RG, and AHF-RG group showed a decreased plasma CRP and increase plasma NO activities compared to AHF group. In addition, these groups revealed reduced 4-HNE, NF-kB, TNF-α, IL-6, COX-2, ICAM-1, VCAM-1 and enhanced eNOS expression in the aorta.

CONCLUSION

These results suggest that EX alone, KRG alone, and combined treatment of EX and KRG may be an effective anti-inflammatory therapeutic for the atherosclerosis, possibly acting via the decreased of CRP and pro-inflammation proteins and the increased NO and eNOS.

Defective Wound-healing in Aging Gingival Tissue

Aging may negatively affect gingival wound-healing. However, little is known about the mechanisms underlying this phenomenon. The present study examined the cellular responses associated with gingival wound-healing in aging. Primary cultures of human gingival fibroblasts were obtained from healthy young and aged donors for the analysis of cell proliferation, cell invasion, myofibroblastic differentiation, and collagen gel remodeling. Serum from young and old rats was used to stimulate cell migration. Gingival repair was evaluated in Sprague-Dawley rats of different ages. Data were analyzed by the Mann-Whitney and Kruskal-Wallis tests, with a p value of .05. Fibroblasts from aged donors showed a significant decrease in cell proliferation, migration, Rac activation, and collagen remodeling when compared with young fibroblasts. Serum from young rats induced higher cell migration when compared with serum from old rats. After TGF-beta1 stimulation, both young and old fibroblasts demonstrated increased levels of alpha-SMA. However, alpha-SMA was incorporated into actin stress fibers in young but not in old fibroblasts. After 7 days of repair, a significant delay in gingival wound-healing was observed in old rats. The present study suggests that cell migration, myofibroblastic differentiation, collagen gel remodeling, and proliferation are decreased in aged fibroblasts. In addition, altered cell migration in wound-healing may be attributable not only to cellular defects but also to changes in serum factors associated with the senescence process.

Identification of a novel anti-inflammatory compound, α-cubebenoate from Schisandra chinensis

AIMS OF THE STUDY

Extracts of Schisandra chinensis have been used as an anti-fatigue and tonic agent. Because chronic fatigue syndrome is related to inflammatory and oxidative stress, we assessed whether Schisandra chinensis has anti-inflammatory constituents and studied the effect of a novel α-cubebenoate isolated from Schisandra chinensis.

MATERIALS AND METHODS

α-Cubebenoate was isolated from an extract of Schisandra chinensis fruits. The inductions of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) by lipopolysaccharide (LPS) were quantified by RT-PCR and Western blotting in mouse peritoneal macrophages. Nitric oxide (NO) and prostaglandin E2 (PGE2) were also measured in the media by Griess reagent and EIA method. A mouse model of LPS-induced peritonitis was used to test the in vivo efficacy of α-cubebenoate.

RESULTS

α-Cubebenoate (5-10μg/ml) inhibited the inductions of iNOS and COX-2 in mouse peritoneal macrophages at the mRNA and protein levels. LPS-induced productions of NO and PGE2 were inhibited by α-cubebenoate (5-10μg/ml). In addition, α-cubebenoate inhibited the LPS-induced activation of JNK, but not those of ERK and p38 MAPK in mouse peritoneal macrophages. Furthermore, in the LPS-induced in vivo peritonitis model, α-cubebenoate (1mg/kg) strongly inhibited the accumulation of polymorph nuclear lymphocytes in the peritoneal cavity.

CONCLUSION

α-Cubebenoate inhibited LPS-induced expression of iNOS and COX-2 in a concentration-dependent manner, thereby suppressing productions of NO and PGE2 in vitro in peritoneal macrophages. α-Cubebenoate also inhibited LPS-induced accumulation of polymorph nuclear lymphocytes in LPS-induced peritonitis model in vivo. α-Cubebenoate may act as an anti-fatigue constituent of Schisandra chinensis through anti-inflammation and could be of therapeutic use as a treatment for inflammatory diseases.

Lactobacillus pentosus var. plantarum C29 ameliorates memory impairment and inflammaging in a D-galactose-induced accelerated aging mouse model

Aging is associated with Alzheimer's disease (AD), cardiovascular disease and cancer. Oxidative stress is considered as a major factor that accelerates the aging process. To understand the ability of lactic acid bacteria to ameliorate memory impairment caused by aging, we investigated the effect of Lactobacillus pentosus var. plantarum (C29), which is known to protect against scopolamine-induced memory impairment, on oxidative stress (D-galactose)-induced memory impairment in mice. D-Galactose was subcutaneously injected to 20-week old male C57BL/6J mice for 10 weeks, with oral administration of C29 for the final 5 weeks. Excessive intake of D-galactose not only impaired memory, which was indicated by passive avoidance, Y-maze, and Morris water-maze tasks, but also reduced the expression of brain-derived neurotrophic factor (BDNF) and hippocampal doublecortin (DCX) and the activation of cAMP response element-binding protein (CREB). C29 treatment ameliorated D-galactose-induced memory impairment and reversed the suppression of BDNF and DCX expression and CREB activation. Moreover, C29 decreased the expression of a senescence marker p16 and inflammation markers p-p65, p-FOXO3a, cyclooxygenase (COX)-2, and inducible NO synthase (iNOS). C29 treatment inhibited D-galactose-induced expression of M1 polarization markers tumor necrosis factor-α and arginase II, and attenuated the d-galactose-suppressed expression of M2 markers IL-10, arginase I and CD206. Taken together, these findings suggest that C29 may ameliorate memory impairment and M1 macrophage-polarized inflammation caused by aging.

Leptin is involved in age-dependent changes in response to systemic inflammation in the rat

Obesity contributes to a state of subclinical peripheral and central inflammation and is often associated with aging. Here we investigated the source and contribution of adipose tissue derived cytokines and the cytokine-like hormone leptin to age-related changes in lipopolysaccharide (LPS)-induced brain-controlled sickness-responses. Old (24 months) and young (2 months) rats were challenged with LPS or saline alone or in combination with a neutralizing leptin antiserum (LAS) or control serum. Changes in the sickness-response were monitored by biotelemetry. Additionally, ex vivo fat-explants from young and old rats were stimulated with LPS or saline and culture medium collected and analyzed by cytokine-specific bioassays/ELISAs. We found enhanced duration/degree of the sickness-symptoms, including delayed but prolonged fever in old rats. This response was accompanied by increased plasma-levels of interleukin (IL)-6 and IL-1ra and exaggerated expression of inflammatory markers in brain and liver analyzed by RT-PCR including inhibitor κBα, microsomal prostaglandin synthase and cyclooxygenase 2 (brain). Moreover, for the first time, we were able to show prolonged elevated plasma leptin-levels in LPS-treated old animals. Treatment with LAS in young rats tended to attenuate the early- and in old rats the prolonged febrile response. Fat-explants exhibited unchanged IL-6 but reduced IL-1ra and tumor necrosis factor (TNF)-α release from adipose tissue of aged compared to young animals. In addition, we found increased expression of the endogenous immune regulator microRNA146a in aged animals suggesting a role for these mediators in counteracting brain inflammation. Overall, our results indicate a role of adipose tissue and leptin in “aging-related-inflammation” and age-dependent modifications of febrile-responses.

Aging and its Impact on Innate Immunity and Inflammation: Implications for Periodontitis

The elderly exhibit increased susceptibility to a number of inflammatory or degenerative pathologies. Aging is similarly thought to be associated with increased prevalence and severity of periodontitis, although the underlying causes are poorly understood. Among the plausible mechanisms whereby aging could contribute to increased susceptibility to periodontitis are age-dependent alterations in the innate immune and inflammatory status of the host. This hypothesis is supported by studies in humans and animal models outlined in this Review. Indeed, innate immune cells isolated from elderly subjects exhibit age-related cell-intrinsic defects that could predispose the elderly to deregulated immune and inflammatory responses. Moreover, the investigation of age-related alterations in the tissue environment where recruited inflammatory cells ultimately function could provide complementary, if not better, insights into the impact of aging on periodontitis. Integrative approaches combining in vitro and in vivo mechanistic models are underway and can potentially contribute to targeted molecular therapies that can reverse or mitigate the effects of aging on periodontitis and other inflammatory diseases.

Down-regulation of oxidative stress and COX-2 and iNOS expressions by dimethyl lithospermate in aged rat kidney

Oxidative stress has been proposed to be a major cause of aging and many age-related diseases. Peroxynitrite (ONOO(-)), formed from the reaction of superoxide ((•)O2 (-)) and nitric oxide (NO), is a cytotoxic species that can oxidize various cellular components, such as proteins, lipids, and DNA. The present study investigated whether dimethyl lithospermate (DML), isolated from Salvia miltiorrhiza, modulates age-related increases of ONOO(-), NO, and reactive species (RS) levels and expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). For this study, 20-month-old rats were intraperitoneally injected with 5 or 10 mg/kg/day of DML, and 6-month-old rats were used as young control animals. Our results indicated that DML reduces ONOO(-) levels in a dose-dependent manner. The data also revealed that DML has significant inhibitory effects on NO metabolites and RS generation in a dose-dependent manner during aging. Furthermore, the results of Western blot analysis revealed that DML treatment reduces age-associated increases in COX-2 and iNOS expressions. Thus, this study found that DML caused the decrease of renal oxidative stress and COX-2 and iNOS expressions in aged rats. The significance of the present study is the finding of DML in its potential application against the aging process.

The phytochemical, EGCG, extends lifespan by reducing liver and kidney function damage and improving age-associated inflammation and oxidative stress in healthy rats

It is known that phytochemicals have many potential health benefits in humans. The aim of this study was to investigate the effects of long-term consumption of the phytochemical, epigallocatechin gallate (EGCG), on body growth, disease protection, and lifespan in healthy rats. 68 male weaning Wistar rats were randomly divided into the control and EGCG groups. Variables influencing lifespan such as blood pressure, serum glucose and lipids, inflammation, and oxidative stress were dynamically determined from weaning to death. The median lifespan of controls was 92.5 weeks. EGCG increased median lifespan to 105.0 weeks and delayed death by approximately 8-12 weeks. Blood pressure and serum glucose and lipids significantly increased with age in both groups compared with the levels at 0 week. However, there were no differences in these variables between the two groups during the whole lifespan. Inflammation and oxidative stress significantly increased with age in both groups compared with 0 week and were significantly lower in serum and liver and kidney tissues in the EGCG group. Damage to liver and kidney function was significantly alleviated in the EGCG group. In addition, EGCG decreased the mRNA and protein expressions of transcription factor NF-κB and increased the upstream protein expressions of silent mating type information regulation two homolog one (SIRT1) and forkhead box class O 3a (FOXO3a). In conclusion, EGCG extends lifespan in healthy rats by reducing liver and kidney damage and improving age-associated inflammation and oxidative stress through the inhibition of NF-κB signaling by activating the longevity factors FoxO3a and SIRT1.

Caloric restriction-associated remodeling of rat white adipose tissue: effects on the growth hormone/insulin-like growth factor-1 axis, sterol regulatory element binding protein-1, and macrophage infiltration

The role of the growth hormone (GH)-insulin-like growth factor (IGF)-1 axis in the lifelong caloric restriction (CR)-associated remodeling of white adipose tissue (WAT), adipocyte size, and gene expression profiles was explored in this study. We analyzed the WAT morphology of 6-7-month-old wild-type Wistar rats fed ad libitum (WdAL) or subjected to CR (WdCR), and of heterozygous transgenic dwarf rats bearing an anti-sense GH transgene fed ad libitum (TgAL) or subjected to CR (TgCR). Although less effective in TgAL, the adipocyte size was significantly reduced in WdCR compared with WdAL. This CR effect was blunted in Tg rats. We also used high-density oligonucleotide microarrays to examine the gene expression profile of WAT of WdAL, WdCR, and TgAL rats. The gene expression profile of WdCR, but not TgAL, differed greatly from that of WdAL. The gene clusters with the largest changes induced by CR but not by Tg were genes involved in lipid biosynthesis and inflammation, particularly sterol regulatory element binding proteins (SREBPs)-regulated and macrophage-related genes, respectively. Real-time reverse-transcription polymerase chain reaction analysis confirmed that the expression of SREBP-1 and its downstream targets was upregulated, whereas the macrophage-related genes were downregulated in WdCR, but not in TgAL. In addition, CR affected the gene expression profile of Tg rats similarly to wild-type rats. Our findings suggest that CR-associated remodeling of WAT, which involves SREBP-1-mediated transcriptional activation and suppression of macrophage infiltration, is regulated in a GH-IGF-1-independent manner.

Prolonged sleep fragmentation of mice exacerbates febrile responses to lipopolysaccharide

BACKGROUND

Sleep disruption is a frequent occurrence in modern society. Whereas many studies have focused on the consequences of total sleep deprivation, few have investigated the condition of sleep disruption.

NEW METHOD

We disrupted sleep of mice during the light period for 9 consecutive days using an intermittently rotating disc.

RESULTS

Electroencephalogram (EEG) data demonstrated that non-rapid eye movement (NREM) sleep was severely fragmented and REM sleep was essentially abolished during the 12h light period. During the dark period, when sleep was not disrupted, neither NREM sleep nor REM sleep times differed from control values. Analysis of the EEG revealed a trend for increased power in the peak frequency of the NREM EEG spectra during the dark period. The fragmentation protocol was not overly stressful as body weights and water consumption remained unchanged, and plasma corticosterone did not differ between mice subjected to 3 or 9 days of sleep disruption and home cage controls. However, mice subjected to 9 days of sleep disruption by this method responded to lipopolysaccharide with an exacerbated febrile response.

COMPARISON WITH EXISTING METHODS

Existing methods to disrupt sleep of laboratory rodents often subject the animal to excessive locomotion, vibration, or sudden movements. This method does not suffer from any of these confounds.

CONCLUSIONS

This study demonstrates that prolonged sleep disruption of mice exacerbates febrile responses to lipopolysaccharide. This device provides a method to determine mechanisms by which chronic insufficient sleep contributes to the etiology of many pathologies, particularly those with an inflammatory component.

Periodontal disease immunology: 'double indemnity' in protecting the host

During the last two to three decades our understanding of the immunobiology of periodontal disease has increased exponentially, both with respect to the microbial agents triggering the disease process and the molecular mechanisms of the host engagement maintaining homeostasis or leading to collateral tissue damage. These foundational scientific findings have laid the groundwork for translating cell phenotype, receptor engagement, intracellular signaling pathways and effector functions into a 'picture' of the periodontium as the host responds to the 'danger signals' of the microbial ecology to maintain homeostasis or succumb to a disease process. These findings implicate the chronicity of the local response in attempting to manage the microbial challenge, creating a 'Double Indemnity' in some patients that does not 'insure' health for the periodontium. As importantly, in reflecting the title of this volume of Periodontology 2000, this review attempts to inform the community of how the science of periodontal immunology gestated, how continual probing of the biology of the disease has led to an evolution in our knowledge base and how more recent studies in the postgenomic era are revolutionizing our understanding of disease initiation, progression and resolution. Thus, there has been substantial progress in our understanding of the molecular mechanisms of host-bacteria interactions that result in the clinical presentation and outcomes of destructive periodontitis. The science has embarked from observations of variations in responses related to disease expression with a focus for utilization of the responses in diagnosis and therapeutic outcomes, to current investigations using cutting-edge fundamental biological processes to attempt to model the initiation and progression of soft- and hard-tissue destruction of the periodontium. As importantly, the next era in the immunobiology of periodontal disease will need to engage more sophisticated experimental designs for clinical studies to enable robust translation of basic biologic processes that are in action early in the transition from health to disease, those which stimulate microenvironmental changes that select for a more pathogenic microbial ecology and those that represent a rebalancing of the complex host responses and a resolution of inflammatory tissue destruction.

Anti-aging Effects of Co-enzyme Q10 on Periodontal Tissues

Oxidative stress is associated with age-related reactions. The anti-oxidative effects of a reduced form of co-enzyme Q10 (rCoQ10) suppress oxidative stress, which may contribute to the prevention of age-related inflammatory reactions. We examined the effects of topically applied rCoQ10 on periodontal inflammatory reactions in a rat aging model. Male Fischer 344 rats, 2 (n = 6) and 4 mos (n = 18) of age, were used. All of the two-month-old rats and 6 of the four-month-old rats were sacrificed and 12 remaining four-month-old rats received topically applied ointment with or without 1% rCoQ10 on the gingival surface until they reached 6 mos of age. The rats showed an age-dependent increase in circulating oxidative stress. RCoQ10 decreased oxidative DNA damage and tartrate-resistant acid-phosphatase-positive osteoclasts in the periodontal tissue at 6 mos of age as compared with the control. The same conditions lowered gene expression of caspase-1 and interleukin-1β in the periodontal tissue. Furthermore, Nod-like receptor protein 3 inflammasomes were less activated in periodontal tissues from rCoQ10-treated rats as compared with the control rats. Our results suggest that rCoQ10 suppresses age-related inflammatory reactions and osteoclast differentiation by inhibiting oxidative stress.

How to die chemically? Whole body apoptosis

What would you do if your body decided to die when you were not ready? It appears that some biological program can shut down all bodily functions, in much the same way as apoptosis does so at the cellular level. Pacific salmon and annual cicada die after reproduction. How do they die chemically? Their programmed death after reproduction should have chemical signals. Similarly, pro-inflammatory cytokines, particularly tumor necrosis factor-α and interleukin-1β, could induce death in mammals. Acute massive production of them in sepsis and chronic tiny production in aging could lead to death. Thus, the mechanism of the whole body suicide program could be determined and some people could be rescued from this type of death by elucidating the death program. I propose that the concept of whole body apoptosis, defined as programmed whole body death, be adopted by scientific community.