Dysregulated serum IL-23 and SIRT1 activity in peripheral blood mononuclear cells of patients with rheumatoid arthritis

Wutou decoction attenuates rheumatoid arthritis in rats through SIRT1-mediated deacetylation of the HMGB1/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine (TCM), Wutou Decoction (WTD) has long been used to alleviate arthritis. Emerging studies have reported that WTD could improve the symptoms of rheumatoid arthritis (RA). However, the mechanism by which WTD is involved in the treatment of RA remains elusive, posing a challenge to the worldwide acceptance of WTD as an efficient RA therapy.

AIM OF THE STUDY

This study investigated the antiarthritic efficacy of WTD in a collagen-induced arthritis (CIA) rat model and explored silent information regulator 1 (SIRT1)-mediated deacetylation of the high mobility group box 1 (HMGB1)/NF-κB pathway.

MATERIALS AND METHODS

A rat CIA model was used to evaluate the antiarthritic activity of WTD. Clinical arthritis score assessment, left ankle thickness assessment, micro-CT, histopathological staining, immunofluorescence staining, and ELISA were conducted to elucidate the anti-inflammatory effects of WTD. The M1 macrophage polarization state, cell viability, and invasion were also determined to assess the effects of WTD on macrophage proliferation and invasion in vitro. Additionally, in vivo and in vitro HMGB1 nuclear translocation and NF-κB activation were analysed. Finally, deacetylase activity was assessed by Western blot, NAD+/NADH analysis, and co-immunoprecipitaion.

RESULTS

WTD significantly alleviated arthritis in CIA rats and inhibited pathological changes in joint lesions while concurrently suppressing TNF-α, IL-6, and IL-1β release. Mechanistically, WTD suppressed M1 infiltration in ankle tissues and their invasion in vitro. Furthermore, WTD downregulated HMGB1/p65 nuclear translocation and acetylation, which may be associated with SIRT1 upregulation.

CONCLUSIONS

Overall, WTD potentially alleviates RA through SIRT1-mediated downregulation of HMGB1 and NF-κB acetylation.

Advanced Progress of Histone Deacetylases in Rheumatic Diseases

Rheumatic disease is a disease which is not yet fully clarified to etiology and also involved in a local pathological injury or systemic disease. With the continuous improvement of clinical medical research in recent years, the development process of rheumatic diseases has been gradually elucidated; with the intensely study of epigenetics, it is realized that environmental changes can affect genetics, among which histone acetylation is one of the essential mechanisms in epigenetics. Histone deacetylases (HDACs) play an important role in regulating gene expression in various biological processes, including differentiation, development, stress response, and injury. HDACs are involved in a variety of physiological processes and are promising drug targets in various pathological conditions, such as cancer, cardiac and neurodegenerative diseases, inflammation, metabolic and immune disorders, and viral and parasitic infections. In this paper, we reviewed the roles of HDACs in rheumatic diseases in terms of their classification and function.

Preclinical Characterization of Pharmacologic NAD+ Boosting as a Promising Therapeutic Approach in Rheumatoid Arthritis

OBJECTIVE

We analyzed NAD+ metabolism in patients with rheumatoid arthritis (RA), its association with disease activity and clinical outcomes of RA, and the therapeutic potential of pharmacologic NAD+ boosting.

METHODS

Our study included 253 participants. In the first cohort, comprising 153 RA patients and 56 healthy donors, we assessed NAD+ levels and NAD+ -related gene pathways. We analyzed 92 inflammatory molecules by proximity extension assay. In the second cohort, comprising 44 RA patients starting anti-tumor necrosis factor (anti-TNF) drugs, we evaluated changes in NAD+ levels and their association with clinical response after 3 months. Mechanistic studies were performed ex vivo on peripheral blood mononuclear cells (PBMCs) from patients with RA to test the beneficial effects of NAD+ boosters, such as nicotinamide and nicotinamide riboside.

RESULTS

Reduced NAD+ levels were found in RA samples, in line with altered activity and expression of genes involved in NAD+ consumption (sirtuins, poly[ADP-ribose] polymerase, CD38), transport (connexin 43), and biosynthesis (NAMPT, NMNATs). Unsupervised clustering analysis identified a group of RA patients with the highest inflammatory profile, the lowest NAD+ levels, and the highest disease activity (as shown by the Disease Activity Score in 28 joints). NAD+ levels were modulated by anti-TNF therapy in parallel with the clinical response. In vitro studies using PBMCs from RA patients showed that nicotinamide riboside and nicotinamide increased NAD+ levels via NAMPT and NMNAT and reduced their prooxidative, proapoptotic, and proinflammatory status.

CONCLUSION

RA patients display altered NAD+ metabolism, directly linked to their inflammatory and disease activity status, which was reverted by anti-TNF therapy. The preclinical beneficial effects of NAD+ boosters, as shown in leukocytes from RA patients, along with their proven clinical safety, might pave the way for the development of clinical trials using these compounds.

Age-related mechanisms in the context of rheumatic disease

Ageing is characterized by a progressive loss of cellular function that leads to a decline in tissue homeostasis, increased vulnerability and adverse health outcomes. Important advances in ageing research have now identified a set of nine candidate hallmarks that are generally considered to contribute to the ageing process and that together determine the ageing phenotype, which is the clinical manifestation of age-related dysfunction in chronic diseases. Although most rheumatic diseases are not yet considered to be age related, available evidence increasingly emphasizes the prevalence of ageing hallmarks in these chronic diseases. On the basis of the current evidence relating to the molecular and cellular ageing pathways involved in rheumatic diseases, we propose that these diseases share a number of features that are observed in ageing, and that they can therefore be considered to be diseases of premature or accelerated ageing. Although more data are needed to clarify whether accelerated ageing drives the development of rheumatic diseases or whether it results from the chronic inflammatory environment, central components of age-related pathways are currently being targeted in clinical trials and may provide a new avenue of therapeutic intervention for patients with rheumatic diseases.

The role of resveratrol on rheumatoid arthritis: From bench to bedside

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by symmetrical polyarthritis as its main clinical manifestation. Uncontrolled RA eventually leads to joint deformities and loss of function. Currently, the pathogenesis of RA remains under discussion, and RA treatment is still at the bottleneck stage. Resveratrol has long been regarded as a potential antioxidant drug for RA treatment. Currently, resveratrol is considered to exert therapeutic effects on RA by activating silent information regulator 1 (SIRT1) and its downstream pathways. There is notable crosstalk between the SIRT1 and NF-κB pathways, and these pathways, which play an essential role in the development of RA, are unexpectedly linked to the influence of resveratrol. Based on recent studies of almost all the pathways that resveratrol can affect, this review summarizes a regulatory chain of core components that cover multiple tracks. We also list the effects of resveratrol on immune cells and other subtle controls, which can help clinicians understand the known mechanism of resveratrol and better treat patients with RA.

Macrophage Dysfunction in Autoimmune Rheumatic Diseases and Atherosclerosis

One of the problems of modern medical science is cardiovascular pathology caused by atherosclerotic vascular lesions in patients with autoimmune rheumatic diseases (ARDs). The similarity between the mechanisms of the immunopathogenesis of ARD and chronic low-grade inflammation in atherosclerosis draws attention. According to modern concepts, chronic inflammation associated with uncontrolled activation of both innate and acquired immunity plays a fundamental role in all stages of ARDs and atherosclerotic processes. Macrophage monocytes play an important role among the numerous immune cells and mediators involved in the immunopathogenesis of both ARDs and atherosclerosis. An imbalance between M1-like and M2-like macrophages is considered one of the causes of ARDs. The study of a key pathogenetic factor in the development of autoimmune and atherosclerotic inflammation-activated monocyte/macrophages will deepen the knowledge of chronic inflammation pathogenesis.

An Integrative Network Approach to Identify Common Genes for the Therapeutics in Tuberculosis and Its Overlapping Non-Communicable Diseases

Tuberculosis (TB) is the leading cause of death from a single infectious agent. The estimated total global TB deaths in 2019 were 1.4 million. The decline in TB incidence rate is very slow, while the burden of noncommunicable diseases (NCDs) is exponentially increasing in low- and middle-income countries, where the prevention and treatment of TB disease remains a great burden, and there is enough empirical evidence (scientific evidence) to justify a greater research emphasis on the syndemic interaction between TB and NCDs. The current study was proposed to build a disease-gene network based on overlapping TB with NCDs (overlapping means genes involved in TB and other/s NCDs), such as Parkinson’s disease, cardiovascular disease, diabetes mellitus, rheumatoid arthritis, and lung cancer. We compared the TB-associated genes with genes of its overlapping NCDs to determine the gene-disease relationship. Next, we constructed the gene interaction network of disease-genes by integrating curated and experimentally validated interactions in humans and find the 13 highly clustered modules in the network, which contains a total of 86 hub genes that are commonly associated with TB and its overlapping NCDs, which are largely involved in the Inflammatory response, cellular response to cytokine stimulus, response to cytokine, cytokine-mediated signaling pathway, defense response, response to stress and immune system process. Moreover, the identified hub genes and their respective drugs were exploited to build a bipartite network that assists in deciphering the drug-target interaction, highlighting the influential roles of these drugs on apparently unrelated targets and pathways. Targeting these hub proteins by using drugs combination or drug repurposing approaches will improve the clinical conditions in comorbidity, enhance the potency of a few drugs, and give a synergistic effect with better outcomes. Thus, understanding the Mycobacterium tuberculosis (Mtb) infection and associated NCDs is a high priority to contain its short and long-term effects on human health. Our network-based analysis opens a new horizon for more personalized treatment, drug-repurposing opportunities, investigates new targets, multidrug treatment, and can uncover several side effects of unrelated drugs for TB and its overlapping NCDs.

Gene polymorphisms of SIRT1 in patients with rheumatoid arthritis

AIM

Previous studies have shown that silent information regulator 1 (SIRT1) expression is elevated in rheumatoid arthritis (RA) patients. However, whether gene polymorphisms in SIRT1 gene associated with RA in a Chinese Han population remains to be discussed.

METHOD

In this case-control study, 529 RA patients and 700 healthy controls were selected, and association of 11 SIRT1 gene polymorphisms (rs12415800, rs3740051, rs932658, rs3740053, rs7895833, rs10509291, rs33957861, rs7069102, rs2273773, rs3818292, rs1467568) with RA susceptibility was evaluated.

RESULTS

Frequency of GA+GG genotype of rs3740051 in RA patients was significantly lower than that in healthy controls (P = .037). Frequencies of GC and GC+GG genotypes of rs7069102 were significantly lower than those in healthy controls (P = .036, P = .047). Frequencies of GA and GA+GG genotypes of rs1467568 were lower in RA patients as compared to those in healthy controls (P = .011, P = .013). For rs2273773, RA patients who carried the T allele had higher number of tender joints than patients who carried the C allele (P = .033). Other polymorphisms did not associate with RA risk.

CONCLUSION

The findings suggest that rs3740051, rs7069102 and rs1467568 variants in SIRT1 gene are related to RA susceptibility in a Chinese Han population.

A novel cytokine consisting of the p40 and EBI3 subunits suppresses experimental autoimmune arthritis via reciprocal regulation of Th17 and Treg cells

OBJECTIVE

The interleukin (IL)-12 cytokine family is closely related to the development of T helper cells, which are responsible for autoimmune disease enhancement or suppression. IL-12 family members are generally heterodimers and share three α-subunits (p35, p19, and p28) and two β-subunits (p40 and EBI3). However, a β-sheet p40 homodimer has been shown to exist and antagonize IL-12 and IL-23 signaling ¹. Therefore, we assumed the existence of a p40-EBI3 heterodimer in nature and sought to investigate its role in immune regulation.

METHODS

The presence of the p40-EBI3 heterodimer was confirmed by ELISA, immunoprecipitation, and western blotting. A p40-EBI3 vector and p40-EBI3-Fc protein were synthesized to confirm the immunological role of this protein in mice with collagen-induced arthritis (CIA). The anti-inflammatory effects of p40-EBI3 were analyzed with regard to clinical, histological, and immune cell-regulating features in mice with CIA.

RESULTS

Clinical arthritis scores and the expression levels of proinflammatory cytokines (e.g., IL-17, IL-1β, IL-6, and TNF-α) were significantly attenuated in p40-EBI3-overexpressing and p40-EBI3-Fc-treated mice with CIA compared to vehicle-treated mice with CIA. Structural joint damage and vessel formation-related gene expression were also reduced by p40-EBI3 heterodimer treatment. In vitro, the p40-EBI3-Fc protein significantly suppressed the differentiation of Th17 cells and reciprocally induced CD4⁺CD25⁺Foxp3⁺ (regulatory T) cells. p40-EBI3 also inhibited osteoclast formation in a concentration-dependent manner.

CONCLUSION

In this study, p40-EBI3 ameliorated proinflammatory conditions both in vivo and in vitro. We propose that p40-EBI3 is a novel anti-inflammatory cytokine involved in suppressing the immune response through the expansion of Treg cells and suppression of Th17 cells and osteoclastogenesis.

Regulation of Sirt1 on energy metabolism and immune response in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease. Synovial hyperplasia and persistent inflammation serve as its typical pathological manifestations, which ultimately lead to joint destruction and function loss. Both clinical observations and metabolomics studies have revealed the prevalence of metabolic disorders in RA. In inflammatory immune microenvironments, energy metabolism is profoundly changed. Increasingly evidences suggest that this abnormality is involved in the occurrence and development of RA-related inflammation. Unsurprisingly, many energy metabolism sensors have been confirmed with immunoregulatory properties. As a representative, silent information regulator type 1 (Sirt1) controls many aspects of immune cells, such as cell lifespan, polarization, and secretion by functioning as a transcriptional regulator. Because of the profound clinical implication, researches on Sirt1 in the regulation of energy metabolism and immune functions under RA conditions have gradually gained momentum. This signaling balances glycolysis, lipid metabolism and insulin secretion orchestrating with other metabolism sensors, and consequently affects immune milieu through a so-called metabolism-immune feedback mechanism. This article reviews the involvement of Sirt1 in RA by discussing its impacts on energy metabolism and immune functions, and specially highlights the potential of Sirt1-targeting anti-rheumatic regimens. It also provides a theoretical basis for clarifying the mystery about the high incidence of metabolic complications in RA patients and identifying new anti-rheumatic reagents.

Automatic medium exchange for micro-volume cell samples based on dielectrophoresis

Cell medium exchange is a crucial step for life science and medicine. However, conventional cell medium exchange methods, including centrifuging and filtering, show limited ability for micro-volume cell samples such as circulating tumor cell (CTC) and circulating fetal cell (CFC). In this paper, we proposed an automatic medium exchange method for micro-volume cell samples based on dielectrophoresis (DEP) in microfluidic chip. Fresh medium and cell suspension were introduced into the microfluidic channel as the laminar flow. Plane stair-shaped interdigital electrodes were employed to drive the cells from the cell suspension to fresh media directly by DEP force. Additionally, we characterized and optimized the cell medium exchange according to both the theory and experiments. In the end, we achieved a 96.9% harvest rate of medium exchange for 0.3 μL samples containing micro-volume cells. For implementing an automatic continuous cell medium exchange, the proposed method can be integrated into the automatic cell processing system conveniently. Furthermore, the proposed method is a great candidate in micro-volume cell analysis and processing, cell electroporation, single cell sequencing, and other scenarios.

Gingival transcriptomics of follicular T cell footprints in progressing periodontitis

Follicular helper T cells (Tfh) cells have been identified in the circulation and in tertiary lymphoid structures in chronic inflammation. Gingival tissues with periodontitis reflect chronic inflammation, so genomic footprints of Tfh cells should occur in these tissues and may differ related to aging effects. Macaca mulatta were used in a ligature-induced periodontitis model [adult group (aged 12-23 years); young group (aged 3-7 years)]. Gingival tissue and subgingival microbiome samples were obtained at matched healthy ligature-induced disease and clinical resolution sites. Microarray analysis examined Tfh genes (n = 54) related to microbiome characteristics documented using 16S MiSeq. An increase in the major transcription factor of Tfh cells, BCL6, was found with disease in both adult and young animals, while master transcription markers of other T cell subsets were either decreased or showed minimal change. Multiple Tfh-related genes, including surface receptors and transcription factors, were also significantly increased during disease. Specific microbiome patterns were significantly associated with profiles indicative of an increased presence/function of Tfh cells. Importantly, unique microbial complexes showed distinctive patterns of interaction with Tfh genes differing in health and disease and with the age of the animals. An increase in Tfh cell responsiveness occurred in the progression of periodontitis, affected by age and related to specific microbial complexes in the oral microbiome. The capacity of gingival Tfh cells to contribute to localized B cell activation and active antibody responses, including affinity maturation, may be critical for controlling periodontal lesions and contributing to limiting and/or resolving the lesions.

The Effect of Repeated Whole-Body Cryotherapy on Sirt1 and Sirt3 Concentrations and Oxidative Status in Older and Young Men Performing Different Levels of Physical Activity

Background: The activity of antioxidant enzymes and sirtuins (Sirt) decreases along with age, which is counteracted by aerobic training. Sirtuins increase antioxidant defence. Whole-body cryotherapy (WBC) increases total antioxidant capacity (TAC) in young men. The aim of our study was to assess the impact of 24 WBC treatments on the blood concentration of selected sirtuins and the level of antioxidant defence as well as oxidative stress index of training and non-training men depending on age. Methods: The study involved 40 males. In each group, there were 10 non-training older and young men (60 NTR and 20 NTR), and 10 older and young long-distance runners (60 TR, 20 TR). During an 8-week period, participants underwent 24 WBC treatments (3 min −130 °C), which were performed three times a week (Monday, Wednesday, Friday). The concentrations of Sirt1, Sirt3, TAC, total oxidative status and the activity of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in the blood were determined before 1 WBC and after 1 WBC, 12 WBC and 24 WBC. Results: After 1 WBC, the activity of GPx and the concentration of Sirt1 and TAC in 60 TR and TAC in 60 NTR increased. After 12 WBC, the level of Sirt1 in 20 NTR and SOD in 20 TR increased. After 24 WBC, the level of Sirt1 increased in 60 TR and in 20 NTR, Sirt3 in 60 TR and SOD in 20 TR. Conclusions: Cryogenic temperatures increase blood levels of Sirt1 and Sirt3 and systemic antioxidant defence in men, but the effect is dependent on age, level of performed physical activity and the number of applied treatments.

Evaluation of Interleukin-23 and JAKs/STATs/SOCSs/ROR-γt Expression in Type 2 Diabetes Mellitus Patients Treated With or Without Sitagliptin

The production of interleukin-23 (IL-23) and the expression levels of related genes were evaluated in type 2 diabetes mellitus patients. The correlations between them were also determined. Thirty patients without sitagliptin (sitagliptin negative; SN), 30 patients with sitagliptin (sitagliptin positive; SP), and 30 healthy controls (HCs) were recruited. The level of IL-23 in the supernatant of anti CD3-activated peripheral blood mononuclear cells (PBMCs) was assessed using enzyme-linked immunosorbent assay. The expressions of IL-23, JAK1/JAK2/TYK2, STAT1/STAT3, ROR-γt, and SOCS1/SOCS3 in PBMCs were evaluated by real-time polymerase chain reaction. The production of IL-23 and the expressions of IL-23, JAK2, STAT3, and ROR-γt were observed to be enhanced in SN patients versus HCs, while the levels were decreased in SP patients versus SN patients (P < 0.05). SOCS1 and SOCS3 expressions were lower in SN patients than HCs, and their expressions were elevated in SP patients versus SN patients (P < 0.05). In SN patients, positive correlations between the IL-23 with fasting plasma glucose and HbA1c were observed, and JAK2/STAT3/ROR-γt were positively correlated with IL-23. JAK2, STAT3, and ROR-γt were positively related to each other and were negatively related to SOCS3. Enhanced IL-23/JAK2/STAT3/ROR-γt and reduced SOCS1/SOCS3 were found in SN patients. Sitagliptin may regulate the IL-23 and related gene expression.

Impact of glucocorticoids on systemic sirtuin 1 expression and activity in rats with adjuvant-induced arthritis

The class III histone deacetylase sirtuin 1 (SIRT1) plays a pivotal role in numerous biological and physiological functions, including inflammation. An association between SIRT1 and proinflammatory cytokines might exist. In addition to their important role in inflammation associated with rheumatoid arthritis (RA), proinflammatory cytokines mediate the development of systemic effects. Here, we evaluated systemic SIRT1 expression and enzymatic activity, in peripheral blood mononuclear cells (PBMCs) and in liver isolated from rats with adjuvant-induced arthritis (AIA), treated or not with low or high doses of glucocorticoids (GCs). We also measured the production of tumour necrosis factor alpha (TNF) and interleukin-1 beta (IL-1 beta) in PBMCs and liver. We found that SIRT1 expression and activity increased in PBMCs of AIA rats compared to healthy controls and decreased under GC treatment. Similarly, we observed an increased SIRT1 activity in the liver of AIA rats compared to healthy controls which decreased under high doses of GCs. We also found an increase in IL-1 beta and TNF levels in the liver of AIA rats compared to healthy controls, which decreased under high doses of GC. We did not observe a significant correlation between SIRT1 activity and proinflammatory cytokine production in PBMC or liver. In contrast, a strong positive correlation was found between the liver levels of TNF and IL-1 beta (rho=0.9503, p=7.5x10^-21). Our results indicate that increased inflammation in AIA rats compared to healthy control is accompanied by an increased SIRT1 activity in both PBMCs and liver, which could be decreased under GC treatment.

Implication of the deacetylase sirtuin-1 on synovial angiogenesis and persistence of experimental arthritis

OBJECTIVES

To decipher the phenotype of endothelial cells (ECs) derived from circulating progenitors issued from patients with rheumatoid arthritis (RA).

METHODS

RA and control ECs were compared according to their proliferative capacities, apoptotic profile, response to tumour necrosis factor (TNF)-α stimulation and angiogenic properties. Microarray experiments were performed to identify gene candidates relevant to pathological angiogenesis. Identified candidates were detected by RT-PCR and western blot analysis in ECs and by immunohistochemistry in the synovium. Their functional relevance was then evaluated in vitro after gene invalidation by small interfering RNA and adenoviral gene overexpression, and in vivo in the mouse model of methyl-bovine serum albumin-(mBSA)-induced arthritis.

RESULTS

RA ECs displayed higher proliferation rate, greater sensitisation to TNF-α and enhanced in vitro and in vivo angiogenic capacities. Microarray analyses identified the NAD-dependent protein deacetylase sirtuin-1 (SIRT1) as a relevant gene candidate. Decreased SIRT1 expression was detected in RA ECs and synovial vessels. Deficient endothelial SIRT1 expression promoted a proliferative, proapoptotic and activated state of ECs through the acetylation of p53 and p65, and lead the development of proangiogenic capacities through the upregulation of the matricellular protein cysteine-rich angiogenic protein-61. Conditional deletion of SIRT1 in ECs delayed the resolution of experimental methyl-bovine serum albumin-(mBSA)-induced arthritis. Conversely, SIRT1 activation reversed the pathological phenotype of RA ECs and alleviates signs of experimental mBSA-induced arthritis.

CONCLUSIONS

These results support a role of SIRT1 in RA and may have therapeutic implications, since targeting angiogenesis, and especially SIRT1, might be used as a complementary therapeutic approach in RA.

Association of cytokine patterns and clinical/laboratory parameters, medication and periodontal burden in patients with rheumatoid arthritis (RA)

To evaluate serum levels of the following cytokines in rheumatoid arthritis subjects with periodontal disease: Interleukin-6, -10, -17, and -23. Patients with rheumatoid arthritis frequently suffer from periodontal disease. Both diseases partly result from a dysregulated immune response. The current study aimed to quantify Interleukin-6, -10, -17, and -23 levels in rheumatoid arthritis. It should be investigated if the periodontal disease would have additional modifying effects. A total of 157 patients were included. Serum levels of IL-6, -10, -17, and -23 were measured by ELISA. Serum IL-10 increased with longer duration of morning stiffness and with higher rheumatoid factor and anti-cyclic citrullinated peptide titres. IL-10 was also elevated with longer duration of prednisolone (< 5 mg daily) and leflunomide therapy. Subjects with lower erythrocyte sedimentation rate/longer leflunomide therapy displayed more missing teeth/more clinical attachment loss. IL-17 was higher in subjects with fewer missing teeth if the following criteria were fulfilled: shorter prednisolone (< 5 mg) and methotrexate therapy, more swollen joints, longer morning stiffness. IL-23 finally was increased in subjects with higher rheumatoid factor and in those with higher periodontal probing depth/clinical attachment loss in the following situations: lower rheumatoid factor and shorter leflunomide therapy. Subjects suffering from dental/periodontal burden show an aberrant systemic cytokine availability of serum IL-6, IL-10, IL-17 and IL-23 related to disease activity and medication. This examination underlines the complexity of potential interactions between disease activity and medication related to periodontal burden.

Cardiac Rehabilitation Increases SIRT1 Activity and β-Hydroxybutyrate Levels and Decreases Oxidative Stress in Patients with HF with Preserved Ejection Fraction

Purpose

Exercise training induces beneficial effects also by increasing levels of Sirtuin 1 (Sirt1) and β-hydroxybutyrate (βOHB). Up to date, no studies investigated the role of exercise training-based cardiac rehabilitation (ET-CR) programs on βOHB levels. Therefore, the present study is aimed at investigating whether a supervised 4-week ET-CR program was able to induce changes in Sirt1 activity and βOHB levels and to evaluate the possible relationship between such parameters, in Heart Failure with preserved Ejection Fraction (HFpEF) patients.

Methods

A prospective longitudinal observational study was conducted on patients consecutively admitted to the Cardiology and Cardiac Rehabilitation Units of “San Gennaro dei Poveri” Hospital in Naples, Italy. In fifty elderly patients affected by HFpEF, in NYHA II and III class, Sirt1 activity, Trolox Equivalent Antioxidant Capacity (TEAC), βOHB, and Oxidized Low-Density Lipoprotein (Ox-LDL) levels were measured before and at the end of the ET-CR program. A control group of 20 HFpEF patients was also recruited, and the same parameters were evaluated 4 weeks after the beginning of the study.

Results

ET-CR induced an increase of Sirt1 activity, βOHB levels, and antioxidant capacity. Moreover, it was associated with a rise in NAD⁺ and NAD⁺/NADH ratio levels and a reduction in Ox-LDL. No changes affected the controls.

Conclusion

The characterization of the ET-CR effects from a metabolic viewpoint might represent an important step to improve the HFpEF management.

Exacerbation of pathogenic Th17-cell-mediated cutaneous graft-versus-host-disease in human IL-1β and IL-23 transgenic humanized mice

Although Th17 cells are closely linked to cutaneous graft-versus-host-disease (GVHD) in mouse models, this association remains unclear in human GVHD. In this study, we established a novel xenogeneic cutaneous GVHD model using humanized mice. To induce the differentiation of human Th17 cells, we created transgenic NOG mice expressing human IL-1β and IL-23 cytokines (hIL-1β/23 Tg) and transplanted with human CD4⁺ T cells. The pathologies of cutaneous GVHD, such as a decrease in body weight, alopecia, and T cell inflammation in the skin, were observed much earlier in hIL-1β/23 Tg mice compared with non-Tg mice after human CD4⁺ T cell transplantation. In the skin of Tg mice, IL-17- and IFNγ-producing pathogenic Th17 cells were significantly accumulated. Furthermore, high infiltration of murine neutrophils was seen in the skin of Tg mice, but not non-Tg mice, which may have been the cause of the severe alopecia. CD4⁺ T-cell-transferred hIL-1β/23 Tg mice were therefore highly sensitive models for inducing cutaneous GVHD mediated by human pathogenic Th17 cells.

An emerging role of interleukin-23 in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune, chronic inflammatory disease and is characterized by destruction of the articular cartilage. A number of pro-inflammatory cytokines work sequentially and in concert with one another to induce the development of RA. IL-23, a member of IL-12 family, is composed of p19 and p40 subunits and it interacts with IL-23 receptor complex to trigger plethora of biochemical actions. A number of preclinical studies have shown the role of IL-23 in the development of RA in rodents. IL-23 receptor signaling is primarily linked to the activation of JAK-STAT, tyrosine kinase 2, NF-kB, and retinoic acid receptor-related orphan receptors. IL-23 produces its osteoclastogenic effects, mainly through IL-17 and Th17 cells suggesting the importance of IL-23/IL-17/Th17 in the joint inflammation and destruction in RA. Monoclonal antibodies targeted against IL-23, including tildrakizumab and guselkumab have been developed and evaluated in clinical trials. However, there are very limited clinical studies regarding the use of IL-23 modulators in RA patients. The present review discusses the different aspects of IL-23 including its structural features, signal transduction pathway, preclinical, and clinical role in RA.

The emerging role of epigenetics in human autoimmune disorders

Epigenetic pathways play a pivotal role in the development and function of the immune system. Over the last decade, a growing body of studies has been published out seeking to explain a correlation between epigenetic modifications and the development of autoimmune disorders. Epigenetic changes, such as DNA methylation, histone modifications, and noncoding RNAs, are involved in the pathogenesis of autoimmune diseases mainly by regulating gene expression. This paper reviews the importance of epigenetic alterations during the development of the most prevalent human autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), Sjogren’s syndrome (SS), autoimmune thyroid diseases (AITD), and type 1 diabetes (T1D), aiming to provide new insights in the pathogenesis of autoimmune diseases and the possibility to develop novel therapeutic approaches targeting the epigenome.

Serum SIRT1 Is Associated with Frailty and Adipokines in Older Adults

BACKGROUND

Because frailty is a major health concern among older patients, identifying frailty-related biomarkers will help in the early detection and prevention of frailty. Thus, we aimed to determine the association between circulating levels of silent mating-type information regulation 2 homolog 1 (SIRT1) and frailty.

METHODS

We assessed circulating SIRT1 levels in 16 robust, 74 prefrail, and 40 frail older adults. Frailty was diagnosed based on the Fried phenotype. Circulating cytokine and adipokine (e.g., vaspin, adiponectin, and leptin) levels were assessed. Differences in SIRT1 levels among the three subject groups were compared; correlations of SIRT1 levels with physical function and adipokine and cytokine levels were analyzed.

RESULTS

Serum SIRT1 levels were significantly higher among frail older adults than among robust ones. Older adults with slowness or weight loss had high SIRT1 levels. Serum SIRT1 levels negatively correlated with gait speed, even after adjustment for age and sex; age; and insulin, vaspin, and leptin levels; they correlated negatively with phospholipase A2 levels.

CONCLUSIONS

High SIRT1 levels were observed in frail elderly patients and were correlated with decreased physical function. Insulin and adipokine levels might be the link between SIRT1 and frailty, whereas inflammation may not be involved in this process.

A study of Sirt1 regulation and the effect of resveratrol on synoviocyte invasion and associated joint destruction in rheumatoid arthritis

The aim of the current study was to investigate the role and mechanism of sirtuin 1 (Sirt1) in the regulation of synovial cell invasion and joint destruction in rheumatoid arthritis (RA). The Sirt1 protein and mRNA levels in fibroblast‑like synoviocytes (FLS) isolated from RA synovial tissues were compared with normal tissues by western blot and reverse transcription‑polymerase chain reaction. RA FLS were then treated with the Sirt1 agonist resveratrol (1, 3 and 10 µg/ml) for 48 h, and their invasiveness and expression of matrix metalloproteinase (MMP) 1 and MMP13 protein and mRNA were measured. Furthermore, a collagen‑induced arthritis (CIA) rat model was established and the rats were divided into a model group, and low‑ and high‑dose resveratrol (2.5 and 10 mg/kg/day) groups to receive an intraperitoneal injection of resveratrol for 42 consecutive days. The joint morphology, arthritis index (AI), and MMP1 and MMP13 expression in synovial tissues was monitored. The Sirt1 protein and mRNA levels in RA FLS were significantly lower compared with normal FLS (P<0.01). The resveratrol treatment significantly inhibited the invasive ability of RA FLS (P<0.01) and reduced MMP1 and MMP13 expression (P<0.01). The AI in low‑ and high‑dose groups was significantly lower compared with the model group from day 28 (P<0.01). Resveratrol also reduced the swelling and damage and decreased MMP1 and MMP13 expression levels in CIA rats (P<0.01). The resveratrol‑induced upregulation of Sirt1 in RA FLS may significantly inhibit the invasion of these cells and reduce the degree of joint damage, which may be mediated through the inhibition of MMP1 and MMP13 expression. The present results suggested a regulatory role for Sirt1 in RA pathogenesis, and demonstrated the beneficial effects of resveratrol, which may have potential as an alternative therapeutic strategy for the treatment of patients with RA.

SIRT1/Adenosine Monophosphate-Activated Protein Kinase α Signaling Enhances Macrophage Polarization to an Anti-inflammatory Phenotype in Rheumatoid Arthritis

Macrophages are crucially involved in the pathogenesis of rheumatoid arthritis (RA). Macrophages of the M1 phenotype act as pro-inflammatory mediators in synovium, whereas those of the M2 phenotype suppress inflammation and promote tissue repair. SIRT1 is a class 3 histone deacetylase with anti-inflammatory characteristics. However, the role played by SIRT1 in macrophage polarization has not been defined in RA. We investigated whether SIRT1 exerts anti-inflammatory effects by modulating M1/M2 polarization in macrophages from RA patients. In this study, SIRT1 activation promoted the phosphorylation of an adenosine monophosphate-activated protein kinase (AMPK) α/acetyl-CoA carboxylase in macrophages exposed to interleukin (IL)-4, and that this resulted in the expressions of M2 genes, including MDC, FcεRII, MrC1, and IL-10, at high levels. Furthermore, these expressions were inhibited by sirtinol (an inhibitor of SIRT1) and compound C (an inhibitor of AMPK). Moreover, SIRT1 activation downregulated LPS/interferon γ-mediated NF-κB activity by inhibiting p65 acetylation and the expression of M1 genes, such as CCL2, iNOS, IL-12 p35, and IL-12 p40. Macrophages from SIRT1 transgenic (Tg)-mice exhibited enhanced polarization of M2 phenotype macrophages and reduced polarization of M1 phenotype macrophages. In line with these observations, SIRT1-Tg mice showed less histological signs of arthritis, that is, lower TNFα and IL-1β expressions and less severe arthritis in the knee joints, compared to wild-type mice. Taken together, the study shows activation of SIRT1/AMPKα signaling exerts anti-inflammatory activities by regulating M1/M2 polarization, and thereby reduces inflammatory responses in RA. Furthermore, it suggests that SIRT1 signaling be viewed as a therapeutic target in RA.

IL-23 and Th17 Disease in Inflammatory Arthritis

IL-23, which is composed of p19 and p40 subunits, is a proinflammatory cytokine that contributes to the formation and maintenance of Th17 cells in inflammatory autoimmune diseases. IL-23 is a human osteoclastogenic cytokine and anti-IL-23 antibody attenuates paw volume and joint destruction in CIA rats. IL-23 levels in serum and synovial fluid are high in rheumatoid arthritis (RA) patients, and IL-23 may be a useful biomarker for the diagnosis of RA. In addition, IL-23 affects the pathogenesis of inflammation and bone destruction through interaction with other cytokines such as IL-17 and TNF-α. Furthermore, polymorphisms of IL23R are a risk factor for ankylosing spondylitis (AS) and psoriatic arthritis (PsA), which indicates that IL-23 is also involved in the pathogenesis of spondyloarthritis (SpA). Finally, IL-17 and IL-23 inhibitors reduce the clinical manifestations of SpA. Thus, the IL-23/Th17 pathway is a therapeutic target for the treatment of inflammatory arthritis.

Aneurysmal subarachnoid hemorrhage lead to systemic upregulation of IL-23/IL-17 inflammatory axis

IL-23 and IL-17 are pro-inflammatory cytokines. IL-23 is secreted by activated macrophages and dendritic cells, while IL-17 by Th17 cells. Serum IL-23 and IL-17 are known to be elevated in numerous inflammatory diseases including neurodegenerative diseases. The role of serum IL-23 and IL-17 in aneurysmal subarachnoid hemorrhage (aSAH) has still not been investigated. The present work investigates the serum IL-23 and IL-17 levels and their association with post hemorrhagic complications and clinical outcome in patients with aSAH.

METHODS

In this study, 80 patients with aSAH (Hunt and Hess grade I-V) were prospectively recruited. We enrolled 24 control patients with lumbar spinal stenosis. Peripheral venous blood was withdrawn from controls and from aSAH patients at day 1 and day 7, allowed to clot and centrifuged to obtain serum. Enzyme linked immunoassay kits were employed to quantify the serum levels of IL-23 and IL-17 by applying 50µL of serum samples. Post hemorrhagic complications and clinical outcome were documented prospectively from patient's hospital record.

RESULTS

Serum IL-23 and IL-17 levels were significantly elevated in aSAH patients at day 1 and day 7 (n=80) as compared to control patients (n=24). Further analysis after dichotomy of patients who suffered from post hemorrhagic complications including cerebral vasospasm, chronic hydrocephalus, seizures, cerebral ischemia, delayed neurological deficits showed differential correlations with different post hemorrhagic complications (Table 1). Serum IL-23 and IL-17 levels did not correlate with clinical outcome.

CONCLUSION

Serum IL-23 and IL-17 levels were elevated in patients with aSAH showing upregulation of IL-23/IL-17 inflammatory axis after aSAH. Serum IL-23 and IL-17 showed differential correlations with post hemorrhagic complications and no correlation with clinical outcome.

Changes in sirtuin 2 and sirtuin 3 mRNA expressions in rheumatoid arthritis

OBJECTIVE

Sirtuins (SIRTs) play a prominent role in metabolism, apoptosis, aging, inflammation, and epigenetics. Inflammation, apoptosis, and epigenetics are pathogenic issues in rheumatoid arthritis (RA). This study aimed to evaluate SIRT2 and SIRT3 mRNA expressions in patients with RA.

MATERIAL AND METHODS

Fifty-four patients with RA and 26 healthy controls were enrolled. Disease activity was determined using the disease activity score (DAS) 28-erythrocyte sedimentation rate (ESR) (score of >2.6 was considered to be active). SIRT2 and SIRT3 mRNA expressions in the extracellular plasma were investigated by real-time PCR.

RESULTS

SIRT3 mRNA expression was higher in the RA group than in the healthy control group (4.64 fold, p<0.001), whereas SIRT2 mRNA expression was relatively lower in the RA group than in the healthy control group (0.55 fold, p=0.109). However, SIRT2 (1.73 fold, p=0.065) and SIRT3 (3.58 fold, p=0.051) mRNA expressions were relatively higher in patients with active RA than in those with inactive RA.

CONCLUSION

In RA, SIRT3 mRNA expression is increased, whereas SIRT2 mRNA expression is decreased. Conversely, SIRT2 and SIRT3 mRNA expressions increase in active RA. Therefore, the fate of each SIRT may differ in RA.

The acetyl code in rheumatoid arthritis and other rheumatic diseases

Growing evidence supports the idea that aberrancies in epigenetic processes contribute to the onset and progression of human immune-mediated inflammatory diseases, such as rheumatoid arthritis (RA). Epigenetic regulators of histone tail modifications play a role in chromatin accessibility and transcriptional responses to inflammatory stimuli. Among these, histone deacetylases (HDACs) regulate the acetylation status of histones and nonhistone proteins, essential for immune responses. Broad-spectrum HDAC inhibitors are well-known anti-inflammatory agents and reduce disease severity in animal models of arthritis; however, selective HDAC inhibitors remain poorly studied. In this review, we describe emerging findings regarding the aberrant acetyl code in RA and other rheumatic disorders which may help identify not only novel diagnostic and prognostic clinical biomarkers for RA, but also new targets for epigenetic pharmacological applications.

Curcumin inhibits osteoclastogenic potential in PBMCs from rheumatoid arthritis patients via the suppression of MAPK/RANK/c-Fos/NFATc1 signaling pathways

The aim of the present study was to determine the effects of curcumin on the osteoclastogenic potential of peripheral blood mononuclear cells (PBMCs) obtained from patients with rheumatoid arthritis (RA), and to investigate the underlying molecular mechanisms. PBMCs from patients with RA (n=12) and healthy controls (n=10) were cultured to assess osteoclastogenic potential. The number of tartrate-resistant acid phosphatase-positive osteoclasts differentiated from PBMCs isolated from patients with RA was significantly increased compared with that of the healthy controls. In addition, the osteoclast number in patients with RA was correlated with the clinical indicators, Sharp score (r=0.810; P=0.001) and lumbar T-score (r=−0.685; P=0.014). Furthermore, the resorption area was increased in the RA group compared with the healthy controls. The mRNA and protein expression levels in PBMC-derived osteoclasts treated with curcumin were measured by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. Curcumin inhibited the osteoclastogenic potential of PBMCs, potentially by suppressing activation of extracellular signal-regulated kinases 1 and 2, p38 and c-Jun N-terminal kinase, and inhibiting receptor activator of nuclear factor κB (RANK), c-Fos and nuclear factor of activated T cells (NFATc1) expression. The results of the present study demonstrated that curcumin may inhibit the osteoclastogenic potential of PBMCs from patients with RA through the suppression of the mitogen-activated protein kinase/RANK/c-Fos/NFATc1 signaling pathways, and that curcumin may be a potential novel therapeutic agent for the treatment of bone deterioration in inflammatory diseases such as RA.

Regulation of Memory T Cells by Interleukin-23

Interleukin-23 (IL-23), a member of the IL-12 family of cytokines, is a heterodimeric cytokine. It is composed of subunits p40 (shared with IL-12) and p19 (an IL-12 p35-related subunit) and is secreted by several types of immune cells, such as natural killer cells and dendritic cells. The IL-23 receptor is composed of the subunit IL-12Rβ1 and the IL-23-specific subunit IL-23R. The binding of IL-23 to its specific cell surface receptor regulates a number of functions, including proliferation and differentiation of cells and secretion of cell factors. Memory T cells are a subset of T cells that secrete numerous important cell factors, and they function in the immune response to infection and diseases like cancer, autoimmune disease and bronchial asthma. IL-23R is expressed on the surface of memory T cells, which suggests that it can specifically regulate memory T cell function. IL-23 has been widely used as a clinical indicator in immune-related diseases and shows potential for use in disease treatment. Here we review the current progress in the study of the role of IL-23 in the regulation of memory T cells.

Macrophage polarization in response to oral commensals and pathogens

Macrophages have been identified in the periodontium. Data have phenotypically described these cells, demonstrated changes with progressing periodontal disease, and identified their ability to function in antigen-presentation critical for adaptive immune responses to individual oral bacterium. Recent evidence has emphasized an important role for the plasticity of macrophage phenotypes, not only in the resulting function of these cells in various tissues, but also clear differences in the stimulatory signals that result in M1 (classical activation, inflammatory) and M2 (alternative activation/deactivated, immunomodulatory) cells. This investigation hypothesized that the oral pathogens, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans induce M1-type cells, while oral commensal bacteria primarily elicit macrophage functions consistent with an M2 phenotype. However, we observed that the M1 output from P. gingivalis challenge, showed exaggerated levels of pro-inflammatory cytokines, with a much lower production of chemokines related to T-cell recruitment. This contrasted with A. actinomycetemcomitans infection that increased both the pro-inflammatory cytokines and T-cell chemokines. Thus, it appears that P. gingivalis, as an oral pathogen, may have a unique capacity to alter the programming of the M1 macrophage resulting in a hyperinflammatory environment and minimizing the ability for T-cell immunomodulatory influx into the lesions.

Honokiol possesses potential anti-inflammatory effects on rheumatoid arthritis and GM-CSF can be a target for its treatment

OBJECTIVE

To observe the anti-inflammatory effects of honokiol in primary cultures of peripheral blood mononuclear cells of rheumatoid arthritis patients, the pro-inflammatory cytokines and potential targets were investigated.

METHODS

The levels of GM-CSF, IL-1β, TNF-α and IL-8 were determined by ELISA assay. The genes and proteins expression were analyzed by real-time PCR and Western blotting respectively.

RESULTS

The serum IL-1β, TNF-α and GM-CSF levels were 1.76-, 2.16- and 3.57-fold increased in patients with RA as compared to those of control group. Honokiol inhibited the expression levels of IL-1β, TNF-α, GM-CSF and IL-8 in PBMCs with a dose-dependent manner. Measurements obtained from supernatants were positively correlated between TNF-α and IL-1β, moreover, similar results found TNF-α levels positively correlated with GM-CSF and IL-8 activity in the supernatants of PBMCs isolated from RA patients. Furthermore, the mRNA and protein expression of IL-1β, GM-CSF and IL-8 were up-regulated when the PBMCs exposure to TNF-α, however, honokiol treatment significantly reversed the expression of IL-1β, TNF-α and GM-CSF in response to TNF-α with a dose-dependent manner.

CONCLUSIONS

This study demonstrates that honokiol could possess potential anti-inflammatory effects and inhibits TNF-α-induced IL-1β, GM-CSF and IL-8 production in PBMCs from rheumatoid arthritis patients.