Multifactorial Activation of NLRP3 Inflammasome: Relevance for a Precision Approach to Atherosclerotic Cardiovascular Risk and Disease

Intrinsic factors behind long COVID: IV. Hypothetical roles of the SARS-CoV-2 nucleocapsid protein and its liquid-liquid phase separation

When the SARS-CoV-2 virus infects humans, it leads to a condition called COVID-19 that has a wide spectrum of clinical manifestations, from no symptoms to acute respiratory distress syndrome. The virus initiates damage by attaching to the ACE-2 protein on the surface of endothelial cells that line the blood vessels and using these cells as hosts for replication. Reactive oxygen species levels are increased during viral replication, which leads to oxidative stress. About three-fifths (~60%) of the people who get infected with the virus eradicate it from their body after 28 days and recover their normal activity. However, a large fraction (~40%) of the people who are infected with the virus suffer from various symptoms (anosmia and/or ageusia, fatigue, cough, myalgia, cognitive impairment, insomnia, dyspnea, and tachycardia) beyond 12 weeks and are diagnosed with a syndrome called long COVID. Long-term clinical studies in a group of people who contracted SARS-CoV-2 have been contrasted with a noninfected matched group of people. A subset of infected people can be distinguished by a set of cytokine markers to have persistent, low-grade inflammation and often self-report two or more bothersome symptoms. No medication can alleviate their symptoms efficiently. Coronavirus nucleocapsid proteins have been investigated extensively as potential drug targets due to their key roles in virus replication, among which is their ability to bind their respective genomic RNAs for incorporation into emerging virions. This review highlights basic studies of the nucleocapsid protein and its ability to undergo liquid-liquid phase separation. We hypothesize that this ability of the nucleocapsid protein for phase separation may contribute to long COVID. This hypothesis unlocks new investigation angles and could potentially open novel avenues for a better understanding of long COVID and treating this condition.

The NLRP3 Inflammasome as a Pathogenic Player Showing Therapeutic Potential in Rheumatoid Arthritis and Its Comorbidities: A Narrative Review

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterized by chronic synovitis and the progressive destruction of cartilage and bone. RA is commonly accompanied by extra-articular comorbidities. The pathogenesis of RA and its comorbidities is complex and not completely elucidated. The assembly of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activates caspase-1, which induces the maturation of interleukin (IL)-1β and IL-18 and leads to the cleavage of gasdermin D with promoting pyroptosis. Accumulative evidence indicates the pathogenic role of NLRP3 inflammasome signaling in RA and its comorbidities, including atherosclerotic cardiovascular disease, osteoporosis, and interstitial lung diseases. Although the available therapeutic agents are effective for RA treatment, their high cost and increased infection rate are causes for concern. Recent evidence revealed the components of the NLRP3 inflammasome as potential therapeutic targets in RA and its comorbidities. In this review, we searched the MEDLINE database using the PubMed interface and reviewed English-language literature on the NLRP3 inflammasome in RA and its comorbidities from 2000 to 2023. The current evidence reveals that the NLRP3 inflammasome contributes to the pathogenesis of RA and its comorbidities. Consequently, the components of the NLRP3 inflammasome signaling pathway represent promising therapeutic targets, and ongoing research might lead to the development of new, effective treatments for RA and its comorbidities.

Research progress of NLRP3 inflammasome and its inhibitors with aging diseases

In recent years, a new target closely linked to a variety of diseases has appeared in the researchers' vision, which is the NLRP3 inflammasome. With the deepening of the study of NLRP3 inflammasome, it was found that it plays an extremely important role in a variety of physiological pathological processes, and NLRP3 inflammasome was also found to be associated with some age-related diseases. It is associated with the development of insulin resistance, Alzheimer's disease, Parkinson's, cardiovascular aging, hearing and vision loss. At present, the only clinical approach to the treatment of NLRP3 inflammasome-related diseases is to use anti-IL-1β antibodies, but NLRP3-specific inhibitors may be better than the IL-1β antibodies. This article reviews the relationship between NLRP3 inflammasome and aging diseases: summarizes some of the relevant experimental results reported in recent years, and introduces the biological signals or pathways closely related to the NLRP3 inflammasome in a variety of aging diseases, and also introduces some promising small molecule inhibitors of NLRP3 inflammasome for clinical treatment, such as: ZYIL1, DFV890 and OLT1177, they have excellent pharmacological effects and good pharmacokinetics.

Risk Factors and Immunoinflammatory Mechanisms Leading to Atherosclerosis: Focus on the Role of Oral Microbiota Dysbiosis

Cardiovascular diseases (CVD), including myocardial infarction and stroke, are currently the leading cause of morbidity, disability and mortality worldwide. Recently, researchers have focused their attention on the alterations of the gut and oral microbiota, investigating the possible role of their dysbiosis in the pathogenesis and/or progression of CVD. In this regard, it has been shown that endothelial dysfunction, a major feature of CVD, can also be induced by chronic periodontal infection, due to a systemic pro-inflammatory condition, as suggested by increased plasma levels of acute phase proteins, IL-6 and fibrinogen. Moreover, proatherogenic dysfunctions can also be promoted by direct bacterial invasion of the endothelium. This review reports the current evidence about the possible role of oral microbiota dysbiosis and the related immunoinflammatory components in the pathophysiology of atherosclerosis and associated CVD. It is concluded that integration of oral microbiota sampling into clinical practice may result in a more accurate assessment of CV risk in patients and even modify their prognosis.

Portrayal of NLRP3 Inflammasome in Atherosclerosis: Current Knowledge and Therapeutic Targets

We are witnessing the globalization of a specific type of arteriosclerosis with rising prevalence, incidence and an overall cardiovascular disease burden. Currently, atherosclerosis increasingly affects the younger generation as compared to previous decades. While early preventive medicine has seen improvements, research advances in laboratory and clinical investigation promise to provide us with novel diagnosis tools. Given the physio-pathological complexity and epigenetic patterns of atherosclerosis and the discovery of new molecules involved, the therapeutic field of atherosclerosis has room for substantial growth. Thus, the scientific community is currently investigating the role of nucleotide-binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a crucial component of the innate immune system in different inflammatory disorders. NLRP3 is activated by distinct factors and numerous cellular and molecular events which trigger NLRP3 inflammasome assembly with subsequent cleavage of pro-interleukin (IL)-1β and pro-IL-18 pathways via caspase-1 activation, eliciting endothelial dysfunction, promotion of oxidative stress and the inflammation process of atherosclerosis. In this review, we introduce the basic cellular and molecular mechanisms of NLRP3 inflammasome activation and its role in atherosclerosis. We also emphasize its promising therapeutic pharmaceutical potential.

Monocyte to high-density lipoprotein ratio presents a linear association with atherosclerosis and nonlinear association with arteriosclerosis in elderly Chinese population: The Northern Shanghai Study

BACKGROUND AND AIMS

Inflammation closely correlates with atherosclerosis and cardiovascular disease (CVD). Monocyte to high-density lipoprotein cholesterol ratio (MHR) is a novel inflammation index that can be obtained by routine blood tests. We aimed to investigate the associations between MHR and atherosclerosis and arteriosclerosis.

METHODS AND RESULTS

We enrolled 2451 participants from the Northern Shanghai Study. Atherosclerosis (carotid plaque (CP), lower extremity atherosclerotic (LEA) assessed by ankle-brachial index) and arteriosclerosis (arterial stiffness (AS) assessed by carotid-femoral pulse wave velocity) were measured using standard methods. In the univariable logistic regression model, higher MHR was significantly associated with increased AS, CP, and LEA risk. In the multivariable logistic regression model, after adjustment for age, sex, hypertension, diabetes mellitus, body mass index, smoking habit, low-density lipoprotein cholesterol, and family history of premature CVD, quartile 4 (Q4) of MHR was associated with an increased risk of AS (odds ratio (OR) = 1.41; 95% confidence interval (CI):1.05-1.88; P _fortrend = 0.036), CP (OR = 1.35; 95%CI:1.04-1.77; P _{for trend} = 0.044), and LEA (OR = 2.23; 95%CI:1.49-3.35; P _{for trend}< 0.001). Similar results were observed when MHR was analyzed as a continuous variable. The restricted cubic spline (RCS) curve showed that the association between MHR and AS was nonlinear (P _nonlinear = 0.021), but not LEA (P _nonlinear = 0.177) or CP (P _nonlinear = 0.72).

CONCLUSION

MHR presents a linear association with atherosclerosis and a nonlinear association with arteriosclerosis in the elderly Chinese population. These findings may indicate the need for early assessment and intervention for inflammation. The registration number for clinical trials: NCT02368938.

The High Fat Diet Impacts the Plasticity between Fresh and Aged Neutrophils

Metabolic alterations induced by unhealthy lifestyles, including obesity and insulin resistance are often associated with increased innate immune response and chronic inflammation. Cholesterol has been identified as a key metabolite driving the activation of the inflammasome and the "epigenetic memory" in long-term living hematopoietic stem cells. In addition to these mechanisms, the physiological aging of short-living neutrophils is a relevant modifier of their immune competency, as while they egress from medullary niches as "fresh", fully competent, cells, they turn into "aged", disarmed cells, when they extravasate into peripheral tissues to fight against pathogens or they reach the spleen for disposal. We recently observed that cardio-metabolic alterations induced by a lipid enriched unhealthy diet critically accelerate this process. Indeed, the chronic feeding with a high fat diet (HFD) results in the increase of aged neutrophils in the circulation and their accumulation in liver. This profile is associated with a deteriorated insulin response and obesity. The HFD primes aged, but not fresh neutrophils, to infiltrate in the liver and promotes inflammation coupled to altered cell immune architecture in visceral adipose tissue. Preventing the aging of neutrophils via selective ablation of CXCR2, reduces the development of obesity and improves the sensitivity to insulin. In humans, plasma levels of CXCL1, one of the cytokines binding CXCR2 and promoting neutrophil aging, are directly associated with abdominal adiposity and fatty liver independently of other risk factors. Together these findings point to a direct role of aged neutrophils in the development of metabolic disorders.

The role of the gut microbiota in health and cardiovascular diseases

The gut microbiota is critical to human health, such as digesting nutrients, forming the intestinal epithelial barrier, regulating immune function, producing vitamins and hormones, and producing metabolites to interact with the host. Meanwhile, increasing evidence indicates that the gut microbiota has a strong correlation with the occurrence, progression and treatment of cardiovascular diseases (CVDs). In patients with CVDs and corresponding risk factors, the composition and ratio of gut microbiota have significant differences compared with their healthy counterparts. Therefore, gut microbiota dysbiosis, gut microbiota-generated metabolites, and the related signaling pathway may serve as explanations for some of the mechanisms about the occurrence and development of CVDs. Several studies have also demonstrated that many traditional and latest therapeutic treatments of CVDs are associated with the gut microbiota and its generated metabolites and related signaling pathways. Given that information, we summarized the latest advances in the current research regarding the effect of gut microbiota on health, the main cardiovascular risk factors, and CVDs, highlighted the roles and mechanisms of several metabolites, and introduced corresponding promising treatments for CVDs regarding the gut microbiota. Therefore, this review mainly focuses on exploring the role of gut microbiota related metabolites and their therapeutic potential in CVDs, which may eventually provide better solutions in the development of therapeutic treatment as well as the prevention of CVDs.

Oral Porphyromonas gingivalis and Fusobacterium nucleatum Abundance in Subjects in Primary and Secondary Cardiovascular Prevention, with or without Heterozygous Familial Hypercholesterolemia

Background: Low-grade chronic inflammation, promoted by dysbiosis of the gut and oral microbiota, has been shown to contribute to individual susceptibility to atherosclerotic cardiovascular disease (ASCVD). High oral Porphyromonas gingivalis (Pg) and lower Fusobacterium nucleatum (Fn) concentrations have been associated with clinical and experimental atherosclerosis. We assessed oral Pg and Fn abundance in very high-risk patients with previously diagnosed ASCVD, with or without heterozygous familial hypercholesterolemia (HeFH), in subjects with HeFH in primary prevention and in healthy subjects. Methods: In this cross-sectional study, 40 patients with previously diagnosed ASCVD (10 with genetically proven HeFH, and 30 without FH), 26 subjects with HeFH in primary prevention, and 31 healthy subjects were selected to quantify oral Pg and Fn abundance by qPCR and assess oral health status. Results: Compared to healthy subjects, patients with previously diagnosed ASCVD showed greater Pg abundance (1101.3 vs. 192.4, p = 0.03), but similar Fn abundance. HeFH patients with ASCVD had an even greater Pg abundance than did non-HeFH patients and healthy subjects (1770.6 vs. 758.4 vs. 192.4, respectively; p = 0.048). No differences were found in the levels of Pg and Fn abundance in HeFH subjects in primary prevention, as compared to healthy subjects. Conclusions: Greater oral Pg abundance is present in very high-risk patients with previously diagnosed ASCVD, with or without FH, suggesting a potential relationship with CV events. Future studies will assess the predictive value of Pg abundance measurement in ASCVD risk stratification.

Sodium selenite and Se-enriched yeast supplementation in atherosclerotic patients: Effects on the expression of pyroptosis-related genes and oxidative stress status

BACKGROUND AND AIMS

Atherosclerosis as a chronic inflammatory disorder of the arterial wall is the main leading cause of the cardiovascular disease (CVD). Caspase-dependent pyroptosis plays a pivotal role in the pathogenesis of CVD. Selenium (Se) is an important component of the antioxidant defense and plays a crucial role in cardiovascular health. This study aimed to investigate the effects of daily consumption of sodium selenite and Se-enriched yeast on the expression of pyroptosis-related genes, and biomarkers of oxidative stress in patients with atherosclerosis.

METHODS AND RESULTS

In this randomized, double-blinded, placebo-controlled clinical trial, 60 patients with atherosclerosis were recruited. Participants received 200 μg/day of sodium selenite, Se-enriched yeast, or placebo for 8 following weeks. The pyroptosis-related genes' mRNA expression in peripheral blood mononuclear cells (PBMCs) was assessed before and after the intervention. Also, the levels of superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), and glutathione peroxidases (GPX) were measured at baseline and following the intervention. Following sodium selenite and Se-enriched yeast supplementation, the relative expression levels of TLR4, ASC, NLRP3, and NF-κB1 were significantly downregulated (p < 0.05). Furthermore, the changes in GPX were significantly increased after selenite and yeast supplementation (p < 0.05). Also, selenite and yeast consumption caused a statistically significant decrease in the change of MDA level (p < 0.05).

CONCLUSION

In summary, these findings showed that Se supplementation may reduce inflammation through down-regulation of some pro-inflammatory genes, improving antioxidant defenses in atherosclerosis patients. Further research is required to come to a definite conclusion of selenium supplementation on the CVD risk. This study was registered on the Iranian Registry of Clinical Trials website (identifier: RCT20110123005670N28; https://www.irct.ir/).

Osteocalcin-expressing endothelial progenitor cells and serum osteocalcin forms are independent biomarkers of coronary atherosclerotic disease severity in male and female patients

PURPOSE

Osteocalcin (OC), an osteoblast-derived regulator of metabolic processes, and circulating early endothelial progenitor cells (EPC, CD34 - /CD133 + /KDR +) expressing OC (OC +) are potential candidates linking bone metabolism and the vasculature and might be involved in vascular atherosclerotic calcification. This study aimed at assessing the association of circulating levels of different OC forms and of EPCs count with disease severity in patients with documented coronary atherosclerosis (CAD).

METHODS

Patients (n = 59) undergoing coronary angiography were divided, according to stenosis severity, into (1) early coronary atherosclerosis (ECA) (n = 22), and (2) late coronary atherosclerosis (LCA) (n = 37). Total OC (TOC), carboxylated OC (cOC), undercarboxylated OC (unOC) were quantified by ELISA. EPC OC + count was assessed by flow cytometry.

RESULTS

EPC OC + counts showed significant differences between ECA and LCA groups. unOC and unOC/TOC ratio were inversely correlated with EPC OC + count. A significant decrease in TOC and unOC plasma levels was associated with higher cardiovascular risk factors (CVRFs) number. EPC OC + count was correlated with LDL-C, total cholesterol, and triglycerides, with a greater significance in the LCA group. No association between the different forms of circulating OC (TOC, ucOC, cOC) and severity of CAD was found.

CONCLUSION

This study showed a significant association between EPCs (CD34 - /CD133 + /KDR + /OC +), CAD severity and CVRFs, suggesting an active role for EPC OC + in the development of CAD. An inverse correlation between TOC, ucOC, and number of CVRFs was observed, suggesting that OC, regardless of its carboxylation status, may be developed as a further cardiovascular risk biomarker.

The zebrafish model system for dyslipidemia and atherosclerosis research: Focus on environmental/exposome factors and genetic mechanisms

Dyslipidemias and atherosclerosis play a pivotal role in cardiovascular risk and disease. Although some pathophysiological mechanisms underlying these conditions have been unveiled, several knowledge gaps still remain. Experimental models, both in vitro and in vivo, have been instrumental to our better understanding of such complex processes. The latter have often been based on rodent species, either wild-type or, in several instances, genetically modified. In this context, the zebrafish may represent an additional very useful in vivo experimental model for dyslipidemia and atherosclerosis. Interestingly, the lipid metabolism of zebrafish shares several features with that present in humans, recapitulating some molecular features and pathophysiological aspects in a better way than that of rodents. The zebrafish model may be of help to address questions related to exposome factors as well as to genetic features, aiming to dissect selected aspects of the more complex scenario observed in humans. Indeed, exposome-related dyslipidemia/atherosclerosis research in zebrafish may target different scientific questions, related to nutrition, microbiota, temperature, light exposure at the larval stage, exposure to chemicals and epigenetic consequences of such external factors. Addressing genetic features related to dyslipidemia/atherosclerosis using the zebrafish model is already a reality and active research is now ongoing in this promising area. Novel technologies (gene and genome editing) may help to identify new candidate genes involved in dyslipidemia and dyslipidemia-related diseases. Based on these considerations, the zebrafish experimental model appears highly suitable for the study of exposome factors, genes and molecules involved in the development of atherosclerosis-related disease as well as for the validation of novel potential treatment options.

Nrf2 in the Field of Dentistry with Special Attention to NLRP3

The aim of this review article was to summarize the functional implications of the nuclear factor E2-related factor or nuclear factor (erythroid-derived 2)-like 2 (Nrf2), with special attention to the NACHT (nucleotide-binding oligomerization), LRR (leucine-rich repeat), and PYD (pyrin domain) domains-containing protein 3 (NLRP3) inflammasome in the field of dentistry. NLRP3 plays a crucial role in the progression of inflammatory and adaptive immune responses throughout the body. It is already known that this inflammasome is a key regulator of several systemic diseases. The initiation and activation of NLRP3 starts with the oral microbiome and its association with the pathogenesis and progression of several oral diseases, including periodontitis, periapical periodontitis, and oral squamous cell carcinoma (OSCC). The possible role of the inflammasome in oral disease conditions may involve the aberrant regulation of various response mechanisms, not only in the mouth but in the whole body. Understanding the cellular and molecular biology of the NLRP3 inflammasome and its relationship to Nrf2 is necessary for the rationale when suggesting it as a potential therapeutic target for treatment and prevention of oral inflammatory and immunological disorders. In this review, we highlighted the current knowledge about NLRP3, its likely role in the pathogenesis of various inflammatory oral processes, and its crosstalk with Nrf2, which might offer future possibilities for disease prevention and targeted therapy in the field of dentistry and oral health.

Molecular Immune-Inflammatory Connections between Dietary Fats and Atherosclerotic Cardiovascular Disease: Which Translation into Clinics?

Current guidelines recommend reducing the daily intake of dietary fats for the prevention of ischemic cardiovascular diseases (CVDs). Avoiding saturated fats while increasing the intake of mono- or polyunsaturated fatty acids has been for long time the cornerstone of dietary approaches in cardiovascular prevention, mainly due to the metabolic effects of these molecules. However, recently, this approach has been critically revised. The experimental evidence, in fact, supports the concept that the pro- or anti-inflammatory potential of different dietary fats contributes to atherogenic or anti-atherogenic cellular and molecular processes beyond (or in addition to) their metabolic effects. All these aspects are hardly translatable into clinics when trying to find connections between the pro-/anti-inflammatory potential of dietary lipids and their effects on CVD outcomes. Interventional trials, although providing stronger potential for causal inference, are typically small sample-sized, and they have short follow-up, noncompliance, and high attrition rates. Besides, observational studies are confounded by a number of variables and the quantification of dietary intakes is far from optimal. A better understanding of the anatomic and physiological barriers for the absorption and the players involved in the metabolism of dietary lipids (e.g., gut microbiota) might be an alternative strategy in the attempt to provide a first step towards a personalized dietary approach in CVD prevention.

Effect of PCSK9 inhibitors on pulse wave velocity and monocyte-to-HDL-cholesterol ratio in familial hypercholesterolemia subjects: results from a single-lipid-unit real-life setting

AIMS

Subjects with familial hypercholesterolemia (FH) are characterized by an increased amount of low-density lipoprotein cholesterol (LDL-C) that promotes a continuous inflammatory stimulus. Our aim was to evaluate the effect of PCSK9-i on inflammatory biomarkers, neutrophil-to-lymphocyte ratio, monocyte-to-high-density lipoprotein ratio (MHR), and on early atherosclerosis damage analyzed by pulse wave velocity (PWV) in a cohort of FH subjects.

METHODS

In this prospective observational study, we evaluated 56 FH subjects on high-intensity statins plus ezetimibe and with an off-target LDL-C. All subjects were placed on PCSK9-i therapy and obtained biochemical analysis as well as PWV evaluation at baseline and after six months of PCSK9-i therapy.

RESULTS

After six months of add-on PCSK9-i therapy, only 42.9% of FH subjects attained LDL-C targets. As expected, a significant reduction of LDL-C (- 49.61%, p < 0.001) was observed after PCSK9-i therapy. Neutrophil count (NC) and MHR were reduced by PCSK9-i (-13.82% and -10.47%, respectively, p value for both < 0.05) and PWV significantly decreased after PCSK9-i therapy (- 20.4%, p < 0.05). Finally, simple regression analyses showed that ∆ PWV was significantly associated with ∆ LDL-C (p < 0.01), ∆ NC and ∆ MHR (p value for both < 0.05).

CONCLUSIONS

In conclusion, PCSK9-i therapy significantly improved lipid and inflammatory profiles and PWV values in FH subjects; our results support the positive effect of PCSK9-i in clinical practice.

Chemical Modulation of the 1-(Piperidin-4-yl)-1,3-dihydro-2H-benzo[d]imidazole-2-one Scaffold as a Novel NLRP3 Inhibitor

In the search for new chemical scaffolds able to afford NLRP3 inflammasome inhibitors, we used a pharmacophore-hybridization strategy by combining the structure of the acrylic acid derivative INF39 with the 1-(piperidin-4-yl)1,3-dihydro-2H-benzo[d]imidazole-2-one substructure present in HS203873, a recently identified NLRP3 binder. A series of differently modulated benzo[d]imidazole-2-one derivatives were designed and synthesised. The obtained compounds were screened in vitro to test their ability to inhibit NLRP3-dependent pyroptosis and IL-1β release in PMA-differentiated THP-1 cells stimulated with LPS/ATP. The selected compounds were evaluated for their ability to reduce the ATPase activity of human recombinant NLRP3 using a newly developed assay. From this screening, compounds 9, 13 and 18, able to concentration-dependently inhibit IL-1β release in LPS/ATP-stimulated human macrophages, emerged as the most promising NLRP3 inhibitors of the series. Computational simulations were applied for building the first complete model of the NLRP3 inactive state and for identifying possible binding sites available to the tested compounds. The analyses led us to suggest a mechanism of protein–ligand binding that might explain the activity of the compounds.

Effects of anagliptin on the stress induced accelerated senescence of human umbilical vein endothelial cells

Background

Dipeptidyl peptidase 4 (DPP-4) inhibitors have been used to treat type 2 diabetes mellitus (T2DM) via inhibition of the enzymatic activity of DPP-4 in degrading active circulating glucagon-like peptide-1. In addition to their glucose-lowering effect, DPP-4 inhibitors have pleiotropic effects. Cellular senescence regarded as important pathophysiological mechanism underlying many degenerative diseases, including atherosclerosis. This study was performed to examine whether the DPP-4 inhibitor, anagliptin, can directly protect against stress-induced accelerated senescence (SIAS) of vascular endothelial cells, regardless of changes in ambient glucose level.

Methods

Cultured human umbilical vein endothelial cells (HUVECs) were exposed to various concentrations of H₂O₂, and a fixed high concentration of glucose (25 mM) with varying concentrations of palmitate. Changes in cell viability, senescence-associated beta-galactosidase (SA-β-Gal), p16 protein, markers of endoplasmic reticulum (ER) stress, NOX4, NLRP inflammasome, lactate dehydrogenase (LDH) release and interleukin (IL) 1β levels were measured by Cell Counting Kit-8 assay, immunofluorescent staining, Western blotting, and enzyme-linked immunosorbent assay, respectively before and after application of anagliptin.

Results

The application of oxidative and glucolipotoxic stresses markedly increased the degree of SIAS of HUVECs, represented by increased SA-β-Gal immunopositivity and p16 protein expression. Aggravation of ER stress and inflammatory response were also observed through increased levels of ATF4, CHOP, peIF2α, NOX4, NLRP inflammasome, LDH, and IL1β. These changes were markedly reversed by the administration of anagliptin.

Conclusions

The DPP-4 inhibitor anagliptin effectively protects HUVECs against SIAS, suggesting its potential use in the development of new treatment strategies for aging.

Effect of Lipids and Lipoproteins on Hematopoietic Cell Metabolism and Commitment in Atherosclerosis

Hematopoiesis is the process that leads to multiple leukocyte lineage generation within the bone marrow. This process is maintained throughout life thanks to a nonstochastic division of hematopoietic stem cells (HSCs), where during each division, one daughter cell retains pluripotency while the other differentiates into a restricted multipotent progenitor (MPP) that converts into mature, committed circulating cell. This process is tightly regulated at the level of cellular metabolism and the shift from anaerobic glycolysis, typical of quiescent HSC, to oxidative metabolism fosters HSCs proliferation and commitment. Systemic and local factors influencing metabolism alter HSCs balance under pathological conditions, with chronic metabolic and inflammatory diseases driving HSCs commitment toward activated blood immune cell subsets. This is the case of atherosclerosis, where impaired systemic lipid metabolism affects HSCs epigenetics that reflects into increased differentiation toward activated circulating subsets.

Aim of this review is to discuss the impact of lipids and lipoproteins on HSCs pathophysiology, with a focus on the molecular mechanisms influencing cellular metabolism. A better understanding of these aspects will shed light on innovative strategies to target atherosclerosis-associated inflammation.

Inflammaging and neurodegenerative diseases: Role of NLRP3 inflammasome activation in brain atherosclerotic vascular disease

The activation of the NLRP3 inflammasome-IL-1β pathway has been clearly shown to be involved in the pathophysiology of cardiovascular diseases, but its role in cerebral atherosclerotic vascular disease has not been fully clarified. Here we provide an overview on the current knowledge about the relevance of the activation of this mechanism in the onset of acute brain atherosclerotic vascular disease and the subsequent tissue damage. Some variants of NLRP3-related genes seem to reduce the susceptibility to acute ischaemic stroke in selected cohorts, although no clear evidence exists either supporting or excluding any role of this pathway in its pathophysiology. Interestingly, robust experimental and clinical data support a major role of the activation of the NLRP3 inflammasome-IL-1β pathway in the post-event inflammatory cascade which leads to neurodegeneration. This evidence highlights a potential dual role of these molecules in brain pre- and post-ischaemic events, supporting the need for further studies, including clinical trials evaluating the modulation of this pathway for stroke prevention and post-stroke treatment.

Interactions of Oxysterols with Atherosclerosis Biomarkers in Subjects with Moderate Hypercholesterolemia and Effects of a Nutraceutical Combination (Bifidobacterium longum BB536, Red Yeast Rice Extract) (Randomized, Double-Blind, Placebo-Controlled Study)

Background: Oxysterol relationship with cardiovascular (CV) risk factors is poorly explored, especially in moderately hypercholesterolaemic subjects. Moreover, the impact of nutraceuticals controlling hypercholesterolaemia on plasma levels of 24-, 25- and 27-hydroxycholesterol (24-OHC, 25-OHC, 27-OHC) is unknown. Methods: Subjects (n = 33; 18–70 years) with moderate hypercholesterolaemia (low-density lipoprotein cholesterol (LDL-C:): 130–200 mg/dL), in primary CV prevention as well as low CV risk were studied cross-sectionally. Moreover, they were evaluated after treatment with a nutraceutical combination (Bifidobacterium longum BB536, red yeast rice extract (10 mg/dose monacolin K)), following a double-blind, randomized, placebo-controlled design. We evaluated 24-OHC, 25-OHC and 27-OHC levels by gas chromatography/mass spectrometry analysis. Results: 24-OHC and 25-OHC were significantly correlated, 24-OHC was correlated with apoB. 27-OHC and 27-OHC/total cholesterol (TC) were higher in men (median 209 ng/mL and 77 ng/mg, respectively) vs. women (median 168 ng/mL and 56 ng/mg, respectively); 27-OHC/TC was significantly correlated with abdominal circumference, visceral fat and, negatively, with high-density lipoprotein cholesterol (HDL-C). Triglycerides were significantly correlated with 24-OHC, 25-OHC and 27-OHC and with 24-OHC/TC and 25-OHC/TC. After intervention, 27-OHC levels were significantly reduced by 10.4% in the nutraceutical group Levels of 24-OHC, 24-OHC/TC, 25-OHC, 25-OHC/TC and 27-OHC/TC were unchanged. Conclusions: In this study, conducted in moderate hypercholesterolemic subjects, we observed novel relationships between 24-OHC, 25-OHC and 27-OHC and CV risk biomarkers. In addition, no adverse changes of OHC levels upon nutraceutical treatment were found.

Contradictory Effects of NLRP3 Inflammasome Regulatory Mechanisms in Colitis

The inflammasome is an intracellular molecular complex, which is mainly involved in innate immunity. Inflammasomes are formed in response to danger signals, associated with infection and injury, and mainly regulate the secretion of interleukin-1β and interleukin-18. Inflammasome dysregulation is known to be associated with various diseases and conditions, and its regulatory mechanisms have become of great interest in recent years. In the colon, inflammasomes have been reported to be associated with autophagy and the microbiota, and their dysregulation contributes to colitis and. However, the detailed role of inflammasomes in inflammatory bowel disease is still under debate because the mechanisms that regulate the inflammasome are complex and the inflammasome components and cytokines show seemingly contradictory multiple effects. Herein, we comprehensively review the literature on inflammasome functioning in the colon and describe the complex interactions of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome components with inflammatory cytokines, autophagy, and the microbiota in experimental colitis models and patients with inflammatory bowel disease.