Calprotectin Impairs Platelet Survival in Patients With Primary Antiphospholipid Syndrome.

OBJECTIVE: While thrombosis and pregnancy loss are the best-known clinical features of antiphospholipid syndrome (APS), many patients also exhibit "extra-criteria" manifestations, such as thrombocytopenia. The mechanisms that drive APS thrombocytopenia are not completely understood, and no clinical biomarkers are available for predicting antiphospholipid antibody (aPL)-mediated thrombocytopenia. Calprotectin is a heterodimer of S100A8 and S100A9 that is abundant in the neutrophil cytoplasm and released upon proinflammatory neutrophil activation. Here, we sought to evaluate the presence, clinical associations, and potential mechanistic roles of circulating calprotectin in a cohort of primary APS and aPL-positive patients. METHODS: Levels of circulating calprotectin were determined in plasma by the QUANTA Flash chemiluminescent assay. A viability dye-based platelet assay was used to assess the potential impact of calprotectin on aPL-mediated thrombocytopenia. RESULTS: Circulating calprotectin was measured in 112 patients with primary APS and 30 aPL-positive (without APS criteria manifestations or lupus) patients as compared to patients with lupus (without APS), patients with unprovoked venous thrombosis (without aPL), and healthy controls. Levels of calprotectin were higher in patients with primary APS and aPL-positive patients compared to healthy controls. After adjustment for age and sex, calprotectin level correlated positively with absolute neutrophil count (r = 0.41, P < 0.001), positively with C-reactive protein level (r = 0.34, P = 0.002), and negatively with platelet count (r = -0.24, P = 0.004). Mechanistically, we found that calprotectin provoked aPL-mediated thrombocytopenia by engaging platelet surface toll-like receptor 4 and activating the NLRP3-inflammasome, thereby reducing platelet viability in a caspase-1-dependent manner. CONCLUSION: These data suggest that calprotectin has the potential to be a functional biomarker and a new therapeutic target for APS thrombocytopenia.

A Recent Update on the Epigenetic Repertoire and Chromatin Modifying Therapy in Diabetes Mellitus: A Comprehensive Review.

Several epigenome studies reported the ability of genes to modulate the lipogenic and glucogenic pathways during insulin signaling as well as the other pathways involved in cardiometabolic diseases. Epigenetic plasticity and oxidative stress are interrelated in the pathophysiology of insulin resistance (IR) and cardiometabolic disease conditions. This review aims to ascertain the previous research evidence pertaining to the role of the epigenome and the variations of histone and non-histone proteins during cardiometabolic disease conditions and insulin signaling to develop effective disease-based epigenetic biomarkers and epigenetics-based chromatic therapy. Several public databases, including PubMed, National Library of Medicine, Medline, and google scholar, were searched for the peer-reviewed and published reports. This study delineates the consistent body of evidence regarding the epigenetic alterations of DNA/histone complexes pertinent to oxidative stress, insulin signaling, metabolic cardiomyopathy, and endothelial dysfunction in patients with cardiometabolic diseases. It has been described that both DNA methylation and post-translational histone alterations across visceral and subcutaneous adipose tissue could facilitate gene transcription to modulate inflammation, lipogenesis, and adipogenesis as the complex network of chromatin-modifying enzymatic proteins involved in the defensive insulin signaling across vasculature in patients with cardiometabolic diseases. Resveratrol, vorinostat, trichostatin, and apabetalone are reported to have significant implications as epigenetic modulators. Based on the epigenetic alterations, a wide range of protein/gene markers, such as interleukin-4 (IL-4) and interferon-γ (IFNγ) genes, may be considered as biomarkers in these patients due to their ability to the polarization of immune cells involved in tissue inflammation and atherosclerosis. Hence, it is crucial to unravel the cell-specific epigenetic information to develop individual risk assessment strategies for chromatin-modifying therapies in patients with cardiometabolic diseases.

Development of Moringa oleifera as functional food targeting NRF2 signaling: antioxidant and anti-inflammatory activity in experimental model systems.

Pharmacological activation of nuclear factor erythroid 2 related factor 2 (NRF2) provides protection against several environmental diseases by inhibiting oxidative and inflammatory injury. Besides high in protein and minerals, Moringa oleifera leaves contain several bioactive compounds, predominantly isothiocyanate moringin and polyphenols, which are potent inducers of NRF2. Hence, M. oleifera leaves represent a valuable food source that could be developed as a functional food for targeting NRF2 signaling. In the current study, we have developed a palatable M. oleifera leaf preparation (henceforth referred as ME-D) that showed reproducibly a high potential to activate NRF2. Treatment of BEAS-2B cells with ME-D significantly increased NRF2-regulated antioxidant genes (NQO1, HMOX1) and total GSH levels. In the presence of brusatol (a NRF2 inhibitor), ME-D-induced increase in NQO1 expression was significantly diminished. Pre-treatment of cells with ME-D mitigated reactive oxygen species, lipid peroxidation and cytotoxicity induced by pro-oxidants. Furthermore, ME-D pre-treatment markedly inhibited nitric oxide production, secretory IL-6 and TNF-α levels, and transcriptional expression of Nos2, Il-6, and Tnf-α in macrophages exposed to lipopolysaccharide. Biochemical profiling by LC-HRMS revealed glucomoringin, moringin, and several polyphenols in ME-D. Oral administration of ME-D significantly increased NRF2-regulated antioxidant genes in the small intestine, liver, and lungs. Lastly, prophylactic administration of ME-D significantly mitigated lung inflammation in mice exposed to particulate matter for 3-days or 3-months. In conclusion, we have developed a pharmacologically active standardized palatable preparation of M. oleifera leaves as a functional food to activate NRF2 signaling, which can be consumed as a beverage (hot soup) or freeze-dried powder for reducing the risk from environmental respiratory disease.

Lipid peroxidation index of particulate matter: Novel metric for quantifying intrinsic oxidative potential and predicting toxic responses.

Using particulate matter (PM) mass as exposure metric does not reveal the intrinsic PM chemical characteristics or toxic potential, which is crucial for monitoring the sources of emission causing adverse health effects and developing risk mitigating strategies. Oxidative stress and ensuing lipid peroxidation (LPO) in the lung are crucial underlying mechanisms of action by which PM drives cardiorespiratory disease. In the current study, we have postulated and demonstrated that the intrinsic potential of PM to elicit LPO, defined as "LPO index" as a novel approach for characterizing oxidative potential of PM (PMOP) and predicting biological toxicity. First, we exposed unsaturated phosphatidylcholine (PC), an abundant phospholipid in the cell membrane, pulmonary surfactant, and lipoproteins to PM and analyzed the total burden of LPO byproducts generated as a measure of LPO index using a LPO reporter dye, BODIPY-C11. PM exposure resulted in a concentration-dependent increase in LPO. Second, we developed a novel method to expose the captured serum apoB100 lipoprotein particles to PM or its constituents and assessed the levels of specific oxidized-phospholipid on apoB100 particles by immunoassay using E06 monoclonal antibody (mab) that recognizes only PC containing oxidized-phospholipids (Ox-PCs). The immunoassay was highly sensitive to evaluate the PM LPO index and was modifiable by metal quenchers and exogenous antioxidant and radical quenchers. Third, to prove the pathophysiological relevance of Ox-PCs, we found that PM exposure generates Ox-PCs in mice lungs, pulmonary surfactant and lung cells. Fourth, we observed that treatment of macrophages with BAL fluid from PM exposed mice or PM-exposed pulmonary surfactant stimulated IL-6 production, which was abrogated by neutralization of Ox-PCs by mab E06 suggesting that Ox-PCs in lungs are proinflammatory. Overall, our study suggests that Ox-PCs as a probe of PM LPO index is a biologically relevant pathogenic biomarker and has a high value for evaluating PMOP.