Immune and inflammatory responses to DNA damage in cancer and aging

Microbially mediated phenolic catabolites exert differential genoprotective activities in normal and adenocarcinoma cell lines

Age-associated decline of nuclear factor erythroid 2-related factor 2 (Nrf2) activity and DNA repair efficiency leads to the accumulation of DNA damage and increased risk of cancer. Understanding the mechanisms behind increased levels of damaged DNA is crucial for developing interventions to mitigate age-related cancer risk. Associated with various health benefits, (poly)phenols and their microbially mediated phenolic catabolites represent a potential means to reduce DNA damage. Four colonic-microbiota-derived phenolic catabolites were investigated for their ability to reduce H2O2-induced oxidative DNA damage and modulate the Nrf2-Antixoidant Response Element (ARE) pathway, in normal (CCD 841 CoN) and adenocarcinoma (HT29) colonocyte cell lines. Each catabolite demonstrated significant (p < .001) genoprotective activity and modulation of key genes in the Nrf2-ARE pathway. Overall, the colon-derived phenolic metabolites, when assessed at physiologically relevant concentrations, reduced DNA damage in both normal and adenocarcinoma colonic cells in response to oxidative challenge, mediated in part via upregulation of the Nrf2-ARE pathway.

DNA Damage Triggers the Activation of Immune Response to Viral Pathogens via Salicylic Acid in Plants

Plants are challenged by various pathogens throughout their lives, such as bacteria, viruses, fungi, and insects; consequently, they have evolved several defense mechanisms. In addition, plants have developed localized and systematic immune responses due to biotic and abiotic stress exposure. Animals are known to activate DNA damage responses (DDRs) and DNA damage sensor immune signals in response to stress, and the process is well studied in animal systems. However, the links between stress perception and immune response through DDRs remain largely unknown in plants. To determine whether DDRs induce plant resistance to pathogens, Arabidopsis plants were treated with bleomycin, a DNA damage-inducing agent, and the replication levels of viral pathogens and growth of bacterial pathogens were determined. We observed that DDR-mediated resistance was specifically activated against viral pathogens, including turnip crinkle virus (TCV). DDR increased the expression level of pathogenesis-related (PR) genes and the total salicylic acid (SA) content and promoted mitogen-activated protein kinase signaling cascades, including the WRKY signaling pathway in Arabidopsis. Transcriptome analysis further revealed that defense- and SA-related genes were upregulated by DDR. The atm-2atr-2 double mutants were susceptible to TCV, indicating that the main DDR signaling pathway sensors play an important role in plant immune responses. In conclusion, DDRs activated basal immune responses to viral pathogens.

Epigenetic aging in older breast cancer survivors and noncancer controls: preliminary findings from the Thinking and Living with Cancer Study

BACKGROUND

Cancer and its treatments may accelerate aging in survivors; however, research has not examined epigenetic markers of aging in longer term breast cancer survivors. This study examined whether older breast cancer survivors showed greater epigenetic aging than noncancer controls and whether epigenetic aging related to functional outcomes.

METHODS

Nonmetastatic breast cancer survivors (n = 89) enrolled prior to systemic therapy and frequency-matched controls (n = 101) ages 62 to 84 years provided two blood samples to derive epigenetic aging measures (Horvath, Extrinsic Epigenetic Age [EEA], PhenoAge, GrimAge, Dunedin Pace of Aging) and completed cognitive (Functional Assessment of Cancer Therapy-Cognitive Function) and physical (Medical Outcomes Study Short Form-12) function assessments at approximately 24 to 36 and 60 months after enrollment. Mixed-effects models tested survivor-control differences in epigenetic aging, adjusting for age and comorbidities; models for functional outcomes also adjusted for racial group, site, and cognitive reserve.

RESULTS

Survivors were 1.04 to 2.22 years biologically older than controls on Horvath, EEA, GrimAge, and DunedinPACE measures (p = .001-.04) at approximately 24 to 36 months after enrollment. Survivors exposed to chemotherapy were 1.97 to 2.71 years older (p = .001-.04), and among this group, an older EEA related to worse self-reported cognition (p = .047) relative to controls. An older epigenetic age related to worse physical function in all women (p < .001-.01). Survivors and controls showed similar epigenetic aging over time, but Black survivors showed accelerated aging over time relative to non-Hispanic White survivors.

CONCLUSION

Older breast cancer survivors, particularly those exposed to chemotherapy, showed greater epigenetic aging than controls that may relate to worse outcomes. If replicated, measurement of biological aging could complement geriatric assessments to guide cancer care for older women.

Roles of DNA damage in renal tubular epithelial cells injury

The prevalence of renal diseases including acute kidney injury (AKI) and chronic kidney disease (CKD) is increasing worldwide. However, the pathogenesis of most renal diseases is still unclear and effective treatments are still lacking. DNA damage and the related DNA damage response (DDR) have been confirmed as common pathogenesis of acute kidney injury and chronic kidney disease. Reactive oxygen species (ROS) induced DNA damage is one of the most common types of DNA damage involved in the pathogenesis of acute kidney injury and chronic kidney disease. In recent years, several developments have been made in the field of DNA damage. Herein, we review the roles and developments of DNA damage and DNA damage response in renal tubular epithelial cell injury in acute kidney injury and chronic kidney disease. In this review, we conclude that focusing on DNA damage and DNA damage response may provide valuable diagnostic biomarkers and treatment strategies for renal diseases including acute kidney injury and chronic kidney disease.

Chaperone-assisted E3 ligase CHIP: A double agent in cancer

The carboxy-terminus of Hsp70-interacting protein (CHIP) is a ubiquitin ligase and co-chaperone belonging to Ubox family that plays a crucial role in the maintenance of cellular homeostasis by switching the equilibrium of the folding-refolding mechanism towards the proteasomal or lysosomal degradation pathway. It links molecular chaperones viz. HSC70, HSP70 and HSP90 with ubiquitin proteasome system (UPS), acting as a quality control system. CHIP contains charged domain in between N-terminal tetratricopeptide repeat (TPR) and C-terminal Ubox domain. TPR domain interacts with the aberrant client proteins via chaperones while Ubox domain facilitates the ubiquitin transfer to the client proteins for ubiquitination. Thus, CHIP is a classic molecule that executes ubiquitination for degradation of client proteins. Further, CHIP has been found to be indulged in cellular differentiation, proliferation, metastasis and tumorigenesis. Additionally, CHIP can play its dual role as a tumor suppressor as well as an oncogene in numerous malignancies, thus acting as a double agent. Here, in this review, we have reported almost all substrates of CHIP established till date and classified them according to the hallmarks of cancer. In addition, we discussed about its architectural alignment, tissue specific expression, sub-cellular localization, folding-refolding mechanisms of client proteins, E4 ligase activity, normal physiological roles, as well as involvement in various diseases and tumor biology. Further, we aim to discuss its importance in HSP90 inhibitors mediated cancer therapy. Thus, this report concludes that CHIP may be a promising and worthy drug target towards pharmaceutical industry for drug development.

Statistical Optimization of Novel Medium to Maximize the Yield of Exopolysaccharide From Lacticaseibacillus rhamnosus ZFM216 and Its Immunomodulatory Activity

The traditional media used for the fermentation of Lactobacilli always contain carbohydrate polymers, which interfere with the analysis of the exopolysaccharide (EPS) produced by the bacteria. In this investigation, a novel medium formulation that could avoid such interference was successfully developed. The beef extract, yeast extract, and peptone used in this formulation were subjected to the removal of polysaccharides before use. The factors affecting the EPS production were optimized by a single factor test, Plackett-Burman design, and Box-Behnken design. The optimum formula was ascertained as: 7.5 g L-1 yeast extract, 12.5 g L-1 beef extract, 10 g L-1 peptone, 21.23 g L-1 maltose, 5.51 g L-1 yeast nitrogen base, 2 g L-1 K2HPO4, 5 g L-1 anhydrous sodium acetate, 2 g L-1 ammonium citrate, 0.58 g L-1 MgSO4⋅7H2O, 0.25 g L-1 MnSO4⋅H2O, and 1 mL L-1 Tween 80. The initial pH of the medium was 6.5. The optimized conditions for fermentation of the strain to produce EPS were as follows: seed size 1%, culture temperature 37°C, and culture time 20 h. Optimum results showed that EPS yield was 496.64 ± 3.15 mg L-1, being 76.70% higher than that of unoptimized conditions (281.07 ± 5.90 mg L-1). The EPS was mainly comprised of glucose and guluronic acid, with a weight average molecular weight of 19.9 kDa; it was also characterized by Fourier transform infrared spectroscopy and UV analysis. EPS was found to significantly enhance the phagocytic capacity, promote the NO, TNF-α, IL-1β, and IL-6 secretion, and improve mRNA expression of cytokines in RAW 264.7 macrophages, indicating its considerable immunomodulatory activity. Western bolt and immunofluorescence results demonstrated that the EPS was able to increase p65 nuclear translocation in the macrophages, indicating that EPS enhanced immunity via the NF-κB signaling pathway. EPS investigated in this work has potential as an attractive functional food supplement candidate for the hypoimmunity population.

Does Inflammation Contribute to Cancer Incidence and Mortality during Aging? A Conceptual Review

Aging is associated with chronic low-grade inflammation, cancer incidence and mortality. As inflammation contributes to cancer initiation and progression, one could hypothesize that age-associated chronic low-grade inflammation contributes to the increase in cancer incidence and/or mortality observed during aging. Here, we review the evidence supporting this hypothesis: (1) epidemiological associations between biomarkers of systemic inflammation and cancer incidence and mortality in older people, (2) therapeutic clues suggesting that targeting inflammation could reduce cancer incidence and mortality and (3) experimental evidence from animal models highlighting inflammation as a link between various mechanisms of aging and cancer initiation and progression. Despite a large body of literature linking aging, inflammation and cancer, convincing evidence for the clear implication of specific inflammatory pathways explaining cancer incidence or mortality during aging is still lacking. Further dedicated research is needed to fill these gaps in evidence and pave the way for the development of applications in clinical care.

Rapid 3D bioprinting of a multicellular model recapitulating pterygium microenvironment

Pterygium is an ocular surface disorder with high prevalence that can lead to vision impairment. As a pathological outgrowth of conjunctiva, pterygium involves neovascularization and chronic inflammation. Here, we developed a 3D multicellular in vitro pterygium model using a digital light processing (DLP)-based 3D bioprinting platform with human conjunctival stem cells (hCjSCs). A novel feeder-free culture system was adopted and efficiently expanded the primary hCjSCs with homogeneity, stemness and differentiation potency. The DLP-based 3D bioprinting method was able to fabricate hydrogel scaffolds that support the viability and biological integrity of the encapsulated hCjSCs. The bioprinted 3D pterygium model consisted of hCjSCs, immune cells, and vascular cells to recapitulate the disease microenvironment. Transcriptomic analysis using RNA sequencing (RNA-seq) identified a distinct profile correlated to inflammation response, angiogenesis, and epithelial mesenchymal transition in the bioprinted 3D pterygium model. In addition, the pterygium signatures and disease relevance of the bioprinted model were validated with the public RNA-seq data from patient-derived pterygium tissues. By integrating the stem cell technology with 3D bioprinting, this is the first reported 3D in vitro disease model for pterygium that can be utilized for future studies towards personalized medicine and drug screening.

Applying a Life Course Biological Age Framework to Improving the Care of Individuals With Adult Cancers: Review and Research Recommendations

Importance

The practice of oncology will increasingly involve the care of a growing population of individuals with midlife and late-life cancers. Managing cancer in these individuals is complex, based on differences in biological age at diagnosis. Biological age is a measure of accumulated life course damage to biological systems, loss of reserve, and vulnerability to functional deterioration and death. Biological age is important because it affects the ability to manage the rigors of cancer therapy, survivors' function, and cancer progression. However, biological age is not always clinically apparent. This review presents a conceptual framework of life course biological aging, summarizes candidate measures, and describes a research agenda to facilitate clinical translation to oncology practice.

Observations

Midlife and late-life cancers are chronic diseases that may arise from cumulative patterns of biological aging occurring over the life course. Before diagnosis, each new patient was on a distinct course of biological aging related to past exposures, life experiences, genetics, and noncancer chronic disease. Cancer and its treatments may also be associated with biological aging. Several measures of biological age, including p16INK4a, epigenetic age, telomere length, and inflammatory and body composition markers, have been used in oncology research. One or more of these measures may be useful in cancer care, either alone or in combination with clinical history and geriatric assessments. However, further research will be needed before biological age assessment can be recommended in routine practice, including determination of situations in which knowledge about biological age would change treatment, ascertaining whether treatment effects on biological aging are short-lived or persistent, and testing interventions to modify biological age, decrease treatment toxic effects, and maintain functional abilities.

Conclusions and Relevance

Understanding differences in biological aging could ultimately allow clinicians to better personalize treatment and supportive care, develop tailored survivorship care plans, and prescribe preventive or ameliorative therapies and behaviors informed by aging mechanisms.

Polymorphism of the DNA repair gene XDP increases the risk of systemic lupus erythematosus but not multiple sclerosis in the Iranian population

BACKGROUND

Xeroderma pigmentosum group D ( XPD ) is an essential component of the nucleotide excision repair (NER) pathway, which can play a major role in DNA repair processes. A deficiency in this pathway was suggested as a causative factor of autoimmune diseases. Therefore, the current study aimed to investigate the relationship between XPD Lys751Gln polymorphism (rs13181) as one of the most common XDP polymorphisms and the risk of two important auto-immune diseases,namely systemic lupus erythematosus (SLE) and multiple sclerosis (MS) in the Iranian population.

METHODS

165 SLE patients and 165 age- and gender-matched healthy controls, and 150 MS patients and 150 age- and gender-matched healthy controls were genotyped for XPD rs13181 A/C polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The results of the present study have indicated that both C allele frequency ( P = 0.012; odds ratio: 1.5; 95% confidence interval: 1.1-2.07) and CC genotype ( P = 0.007; odds ratio: 2.46; 95% confidence interval: 1.2-4.7) in SLE patient were significantly higher than those in control group. Furthermore, there were no significant differences between MS patients and normal subjects concerning the genotype and the allele frequencies.

CONCLUSION

Our findings suggested that XPD rs13181 A/C polymorphism may be a crucial risk factor for the development of SLE but not MS in Iranian patients.

Mechanisms of High-Grade Serous Carcinogenesis in the Fallopian Tube and Ovary: Current Hypotheses, Etiologic Factors, and Molecular Alterations

Ovarian high-grade serous carcinomas (HGSCs) are a heterogeneous group of diseases. They include fallopian-tube-epithelium (FTE)-derived and ovarian-surface-epithelium (OSE)-derived tumors. The risk/protective factors suggest that the etiology of HGSCs is multifactorial. Inflammation caused by ovulation and retrograde bleeding may play a major role. HGSCs are among the most genetically altered cancers, and TP53 mutations are ubiquitous. Key driving events other than TP53 mutations include homologous recombination (HR) deficiency, such as BRCA 1/2 dysfunction, and activation of the CCNE1 pathway. HR deficiency and the CCNE1 amplification appear to be mutually exclusive. Intratumor heterogeneity resulting from genomic instability can be observed at the early stage of tumorigenesis. In this review, I discuss current carcinogenic hypotheses, sites of origin, etiologic factors, and molecular alterations of HGSCs.

Recombinant Spidroin Films Attenuate Individual Markers of Glucose Induced Aging in NIH 3T3 Fibroblasts

The effect of bioresorbable materials on aging in cultured mouse NIH 3T3 fibroblasts treated with elevated glucose concentration was investigated. The cells were grown on films produced from the silkworm fibroin and rS1/9, a recombinant analog of Nephila clavipes spidroin 1. Exposure to 50 mM glucose of the cells grown on uncoated glass support resulted in the cell growth retardation. The average areas of the cells and nuclei and the percentage of apoptotic cells increased, whereas the amount of soluble collagen decreased. In contrast, on the fibroin and spidroin films, the cell density and the percentage of 5-bromo-2'-deoxyuridine (BrdU)-positive cells were higher vs. the cells grown on the glass support. The films protected NIH 3T3 fibroblasts from the glucose-induced death. The most prominent effects on the cell density, BrdU incorporation, and apoptosis prevention were observed in the cells cultured on spidroin films. Unlike the cells grown on glass support (decrease in the soluble collagen production) or fibroin (no effect), production of soluble collagen by the cells grown on spidroin films increased after cell exposure to 50 mM glucose. Molecular analysis demonstrated that 50 mM glucose upregulated phosphorylation of the NFκB heterodimer p65 subunit in the cells grown on the glass support. The treatment of cells grown on fibroin films with 5.5 mM or 50 mM glucose had no effect on p65 phosphorylation. The same treatment decreased p65 phosphorylation in the cells on the spidroin films. These results demonstrate the anti-aging efficacy of biomaterials derived from the silk proteins and suggest that spidroin is more advantageous for tissue engineering and therapy than fibroin.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

Mouse Models to Disentangle the Hallmarks of Human Aging

Model organisms have provided fundamental evidence that aging can be delayed and longevity extended. These findings gave rise to a new era in aging research aimed at elucidating the pathways and networks controlling this complex biological process. The identification of 9 hallmarks of aging has established a framework to evaluate the relative contribution of each hallmark and the interconnections among them. In this review, we revisit these hallmarks with the information obtained exclusively through the generation of genetically modified mouse models that have a significant impact on the aging process. We discuss within each hallmark those interventions that accelerate aging or that have been successful at increasing lifespan, with the final goal of identifying the most promising antiaging avenues based on the current knowledge provided by in vivo models.

Transcriptome analysis reveals lncRNA-mediated complex regulatory network response to DNA damage in the liver tissue of Rattus norvegicus

DNA is prone to damages, which would result in genetic disorders and enhance risk of tumorigenesis. Hence, understanding the molecular mechanisms of DNA damage and repair will provide deep insights into tumorigenesis, carcinogenesis as well as the corresponding treatments. Aiming at investigating potential long noncoding RNAs (lncRNAs) response against DNA damage, we performed a comprehensive transcriptomic analysis based on RNA sequencing data of the liver tissue from Rattus norvegicus, in which DNA damage was induced using aflatoxin B1, ifosfamide and N-nitrosodimethylamine. Through our analyses, numerous novel lncRNAs are identified for the first time, and differential network analysis discloses lncRNA-mediated regulatory networks related to DNA-damage response. The result shows that these DNA-damage-inducing chemicals might disrupt many lncRNA-mediated interactions involved in diverse biological processes and pathways, for example, immune function and cell adhesion. In contrast, the host might also activate a few RNA interactions in response to DNA damage, involving response to drug and regulation of cell cycle.

Clinical significance of systemic immune-inflammation index (SII) and C-reactive protein-to-albumin ratio (CAR) in patients with esophageal cancer: a meta-analysis

Background: Numerous studies have reported that systemic immune-inflammation index (SII) and C-reactive protein-to-albumin ratio (CAR) correlate with tumor progression and prognosis in various types of human cancer. The aim of this study is to systematically investigate the clinical significance of SII and CAR in esophageal cancer (EC).

Methods: We searched a number of databases for articles reporting the effect of pretreatment SII and CAR on the survival of EC patients. Review Manager 5.3 and STATA/SE 14.1 were applied in this meta-analysis. The multivariable-adjusted hazard ratio (HR) was used for calculating the relationship between SII and CAR and overall survival (OS), and the odds ratio (OR) was applied for the clinical pathology.

Results: Five original studies for SII and seven original datasets for CAR were included for analysis. Increased SII showed a significant association with shorter OS in EC patients after surgery (HR: 1.34, 95% CI: 1.15–1.53, P<0.001) and high CAR indicated worse long-term OS in EC (HR: 1.60, 95% CI: 1.29–1.90, P<0.001). Different subgroup analyses were also confirmed the prognostic roles in EC patients. Furthermore, the adverse impacts of elevated SII and CAR on tumor progression were revealed in the infiltration depth, lymph node metastasis, and clinical stage.

Conclusions: Both pretreatment SII and CAR might be promising predictors of cancer survival and tumor progression in EC. Further studies are warranted to verify the clinical usefulness in patients with EC.

Epigenomic drivers of immune dysfunction in aging

Aging inevitably leads to reduced immune function, leaving the elderly more susceptible to infections, less able to respond to pathogen challenges, and less responsive to preventative vaccinations. No cell type is exempt from the ravages of age, and extensive studies have found age-related alterations in the frequencies and functions of both stem and progenitor cells, as well as effector cells of both the innate and adaptive immune systems. The intrinsic functional reduction in immune competence is also associated with low-grade chronic inflammation, termed "inflamm-aging," which further perpetuates immune dysfunction. While many of these age-related cellular changes are well characterized, understanding the molecular changes that underpin the functional decline has proven more difficult. Changes in chromatin are increasingly appreciated as a causative mechanism of cellular and organismal aging across species. These changes include increased genomic instability through loss of heterochromatin and increased DNA damage, telomere attrition, and epigenetic alterations. In this review, we discuss the connections between chromatin, immunocompetence, and the loss of function associated with mammalian immune aging. Through understanding the molecular events which underpin the phenotypic changes observed in the aged immune system, it is hoped that the aged immune system can be restored to provide youthful immunity once more.

Competing Endogenous RNA Network Analysis Reveals Pivotal ceRNAs in Adrenocortical Carcinoma

Objective: To construct ceRNA network and identify pivotal competing endogenous RNAs (ceRNAs) in adrenocortical carcinoma (ACC) using ceRNA network analysis. Methods: The RNA sequencing expression data of 77 ACCs in TCGA were obtained from GEPIA. Cancer specific ceRNAs, cancer specific microRNAs (miRNAs), and cancer specific messenger RNAs (mRNAs) were identified. The interaction of cancer specific miRNAs with cancer specific ceRNAs and cancer specific mRNAs were predicted. CeRNA network was constructed and visualized by Cytoscape 3.7.0 software. The genes in ceRNA network regulated GO terms and regulated pathways were performed by function analysis. Survival analysis of pivotal ceRNAs was performed for the pivotal lncRNAs. Result: Twenty-eight cancer specific ceRNAs, 149 cancer specific miRNAs, and 104 mRNAs were identified. CeRNA network was constructed including 10 ceRNAs, 35 miRNAs, and 34 mRNAs. The genes in ceRNA network regulated GO terms and were classified into three groups: cellular component (CC), molecular function (MF), and biological process (BP). The genes in ceRNA network regulated the following pathways: leukocyte transendothelial migration, and proteoglycans in cancer. Survival analysis showed that CTB-63M22.1 and RP1-241P17.4 were significantly associated with ACC patient disease free survival and overall survival. Conclusion: This study has constructed ceRNA networks in ACC. The study provides a set of pivotal ceRNAs for future investigation into the molecular mechanisms.

DNA Damage and Deficiencies in the Mechanisms of Its Repair: Implications in the Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a perplexing and potentially severe disease, the pathogenesis of which is yet to be understood. SLE is considered to be a multifactorial disease, in which genetic factors, immune dysregulation, and environmental factors, such as ultraviolet radiation, are involved. Recently, the description of novel genes conferring susceptibility to develop SLE even in their own (monogenic lupus) has raised the interest in DNA dynamics since many of these genes are linked to DNA repair. Damage to DNA induces an inflammatory response and eventually triggers an immune response, including those targeting self-antigens. We review the evidence that indicates that patients with SLE present higher levels of DNA damage than normal subjects do and that several proteins involved in the preservation of the genomic stability show polymorphisms, some of which increase the risk for SLE development. Also, the experience from animal models reinforces the connection between DNA damage and defective repair in the development of SLE-like disease including characteristic features such as anti-DNA antibodies and nephritis. Defining the role of DNA damage response in SLE pathogenesis might be strategic in the quest for novel therapies.

Characterization and immunomodulatory activity of an exopolysaccharide produced by Lactobacillus plantarum JLK0142 isolated from fermented dairy tofu

A purified neutral exopolysaccharide (EPS) designated as EPS0142 was obtained from Lactobacillus plantarum JLK0142. EPS0142 consisted of glucose and galactose in an approximate molar ratio of 2.13:1.06 and had a molecular weight of 1.34 × 10⁵ Da. The FT-IR spectrum showed that EPS0142 had a typical polysaccharide absorption pattern. ¹H NMR and ¹³C NMR spectra analysis showed the presence of N-acetylated sugar residues. EPS0142 had no toxic effects on RAW 264.7 cells and significantly improved their phagocytic activity and NO secretion in vitro. Further in vivo studies revealed that the spleen index and splenic lymphocyte proliferation activities of the cyclophosphamide-induced immunosuppression mice treated with a middle-dose (50 mg/kg body weight) or a high-dose (100 mg/kg body weight) of EPS0142 were significantly increased (P < 0.01). In addition, the intestinal immunoglobulin A (sIgA) content and the serum levels of the cytokines, IL-2 and TNF-α, were also significantly (P < 0.05) improved in the high-dose EPS0142 group compared to that in the model control group. These data indicate that the EPS isolated from L. plantarum JLK0142 can effectively improve the immunomodulatory activity of RAW 264.7 cells and stimulate the immune system in cyclophosphamide-induced immunosuppressed mice.

Senescence-Inflammatory Regulation of Reparative Cellular Reprogramming in Aging and Cancer

The inability of adult tissues to transitorily generate cells with functional stem cell-like properties is a major obstacle to tissue self-repair. Nuclear reprogramming-like phenomena that induce a transient acquisition of epigenetic plasticity and phenotype malleability may constitute a reparative route through which human tissues respond to injury, stress, and disease. However, tissue rejuvenation should involve not only the transient epigenetic reprogramming of differentiated cells, but also the committed re-acquisition of the original or alternative committed cell fate. Chronic or unrestrained epigenetic plasticity would drive aging phenotypes by impairing the repair or the replacement of damaged cells; such uncontrolled phenomena of in vivo reprogramming might also generate cancer-like cellular states. We herein propose that the ability of senescence-associated inflammatory signaling to regulate in vivo reprogramming cycles of tissue repair outlines a threshold model of aging and cancer. The degree of senescence/inflammation-associated deviation from the homeostatic state may delineate a type of thresholding algorithm distinguishing beneficial from deleterious effects of in vivo reprogramming. First, transient activation of NF-κB-related innate immunity and senescence-associated inflammatory components (e.g., IL-6) might facilitate reparative cellular reprogramming in response to acute inflammatory events. Second, para-inflammation switches might promote long-lasting but reversible refractoriness to reparative cellular reprogramming. Third, chronic senescence-associated inflammatory signaling might lock cells in highly plastic epigenetic states disabled for reparative differentiation. The consideration of a cellular reprogramming-centered view of epigenetic plasticity as a fundamental element of a tissue's capacity to undergo successful repair, aging degeneration or malignant transformation should provide challenging stochastic insights into the current deterministic genetic paradigm for most chronic diseases, thereby increasing the spectrum of therapeutic approaches for physiological aging and cancer.