Viral co-pathogens in COVID-19 acute respiratory syndrome - what did we learn from the first year of pandemic?

OBJECTIVE: This study aimed to describe the distribution of respiratory pathogens and the occurrence of co-pathogens during the first year of the COVID-19 pandemic. METHODS: We used a multiplex polymerase chain reaction (PCR) panel targeting 23 microorganisms to analyze the oro-pharyngeal samples of patients admitted to our hospital with acute respiratory infection (ARI) between March 1, 2020, and February 28, 2021. We matched 40 to 50 patients who were SARS-CoV-2 positive and SARS-CoV-2 negative per month for age and sex. RESULTS: A total of 939 patients with multiplex PCR test results were included in the study. Respiratory pathogens where detected in only 8/476 (1.6%) patients with COVID-19 versus 87/463 (18.7%) patients with non-COVID-19 ARI patients. Diversity and rates of pathogens vastly differed from previous years but showed seasonal variance. CONCLUSION: Patients with SARS-CoV-2 infection presenting with ARI during the first year of the COVID-19 pandemic demonstrated paucity of respiratory co-pathogens.

Red alga polysaccharides attenuate angiotensin II-induced inflammation in coronary endothelial cells.

The pro-inflammatory vasoconstrictor Angiotensin II can cause endothelial dysfunction and is considered to be one of the mediators of atherosclerosis. Our former results demonstrated that polysaccharides derived from the red alga Porphyridium sp. attenuate inflammatory processes by interfering with tumor necrosis factor-alpha-induced inflammation, in human coronary artery endothelial cells. However, the anti-inflammatory effect of these polysaccharides on inflammation processes occurring under Angiotensin II stimulation is yet unknown. Herein, we studied the polysaccharide's anti-inflammatory effect by quantification of inflammatory markers in Angiotensin II- stimulated Human Coronary Artery Endothelial Cells following pre-treatment with polysaccharides. Inflammatory atherosclerotic pathways up-regulated by Angiotensin II, including adhesion molecule expression and nuclear factor kappa-light-chain-enhancer of activated B cells translocation, were significantly attenuated or diminished in cells pre-treated with the polysaccharides. In addition, the polysaccharides increased the antioxidant response elements activity through the nuclear factor-E2-related factor 2- antioxidant protection system. These polysaccharide's promising abilities may be considered as a basis for future use as a therapeutic agent aimed at improving vascular health by attenuation of the inflammatory atherosclerotic process.

Angiotensin 1-7, but not the thrombin-cleaved osteopontin C-terminal fragment, attenuates osteopontin-mediated macrophage-induced endothelial-cell inflammation.

OBJECTIVE AND DESIGN: Evaluating the pro-/anti-inflammatory activity of the C-terminal cleavage product of osteopontin in comparison to angiotensin 1-7. MATERIAL AND SUBJECTS: Human coronary endothelial cells (hcEC) treated with conditioned media from human U937 macrophages. TREATMENT: Macrophages were (pre)treated with C-terminal, full-length or N-terminal osteopontin (OPN-C, OPN-FL, OPN-N, respectively), angiotensin II, angiotensin 1-7 or TNF-α. OPN-C modulatory capacity was compared to that of Ang1-7 in inhibiting subsequent Ag II, OPN-FL or OPN-N-induced macrophage-mediated endothelial inflammation. METHODS: Protein expression of NFκB, IκB, vCAM-1 and iCAM-1 was assessed using western blot. Promotor activation by NFκB was also assessed by dual-luciferase reporter assay. RESULTS: Conditioned media of macrophages treated with OPN-C induced hcECs' NfκB activation to a lower degree than OPN-FL or OPN-N. Priming of macrophages with angiotensin 1-7 attenuated the endothelial pro-inflammatory effect induced by subsequent exposure of the macrophages to angiotensin II, OPN-FL or OPN-N. This was evidenced by both NfκB activation and vCAM and iCAM expression. In contrast, priming macrophages with OPN-C did not significantly attenuate the subsequent response to the pro-inflammatory cytokines. CONCLUSIONS: OPN-C induces lower macrophage-induced endothelial inflammation compared to OPN-FL or OPN-N, but unlike angiotensin 1-7, fails to prevent endothelial inflammation induced by subsequent pro-inflammatory macrophage stimulation.

An anti-inflammatory effect of red microalga polysaccharides in coronary artery endothelial cells.

BACKGROUND AND AIMS: Polysaccharides (PSs) produced by the red microalga Porphyridium sp. were reported to exhibit anti-inflammatory bioactivities in the human skin. The primary goal of the present research was to assess whether PSs attenuate inflammatory processes by interfering with tumour necrosis factor-alpha (TNF-α)-induced inflammation, in human coronary artery endothelial cells (HCAECs). METHODS: Functional and inflammatory markers were quantified in TNF-α-stimulated HCAECs, with and without pre-treatment with PSs. The expression/activation of these markers was assessed by Western immunoblotting and a luciferase reporter assay. NO levels were measured using the Griess method and intracellular reactive oxygen stress (ROS) was determined with the fluorescent probe 2',7'-dichlorodihydro-fluorescein diacetate (H2DCFDA). RESULTS: The TNF-α-induced up-regulation of inter-cellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) translocation, as well as IκB degradation were significantly attenuated in cells pre-treated with PSs. In addition, PSs were able to inhibit NF-κB activation as well as TNF-α-induced oxidative stress in HCAECs. Endothelial function was also improved, as measured by increased nitric oxide (NO) formation and decreased endothelin (ET-1) protein expression. CONCLUSIONS: This is the first report that demonstrates the anti-inflammatory effect and vaso-relaxing property of red microalgae PSs in a HCAEC-TNF-α induced system. This study lays the foundation for basic research concerning the PS mode of action in biochemical processes involving endothelial dysfunction, and it also holds potential for applied research, possibly promoting the use of PSs as a therapeutic agent or food additive to improve vascular health.

Low Osteopontin N-Terminal Fragment and Carotid Plaque Stability Associated with Statin or Antiplatelet Therapy.

INTRODUCTION: Full-length osteopontin (OPN-FL), whose levels are elevated in association with atherosclerosis, is cleaved by thrombin, resulting in the formation of a putatively biologically-active N-terminal cleavage product (OPNN). This study addresses the hypothesis that statin and antiplatelet therapy in hypertensive patients specifically reduces OPN-N, rather than OPN-FL, in carotid plaques. METHODS: Seventy-four carotid plaques were collected from patients who underwent carotid endarterectomy (CEA). Plaque tissue was used to measure OPN proteins and for histological and immunohistochemical characterization. RESULTS: There were 22 statin-negative and 52 statin-treated patients. In the carotid plaque, immunohistochemical staining for macrophages was higher in statin-negative vs. statin-treated patients (high CD68 immunostaining was in 61.9 vs. 28.6%, p=.03, respectively). OPN-FL staining had a similar trend, but without statistical significance (78.7 vs. 47.8%, p=.08, respectively). Western blot analysis of plaque OPN-FL showed that statin treatment was not associated with significant alteration of its abundance, but with a significantly lower plaque content of OPN-N [median 0.08 (IQR 0.05-1.01) vs. 0.81 (IQR 0.27-2.86), respectively, p=.015]. Comparable pattern of association between OPN proteins and antiplatelet therapy was found: the abundance of OPN-FL was not different in plaques from untreated or treated patients, while the abundance of OPN-N was significantly reduced in antiplatelet treated vs. non-treated patients [0.08, (IQR 0.05-0.66) vs. 0.89, (IQR 0.13-1.94), p=0.004]. CONCLUSION: The effect of anti-atherosclerotic treatment on carotid plaques of hypertensive patients more readily associates with OPN-N than with OPN-FL expression, suggesting that anti-atherosclerotic treatment including statins and antiplatelet drugs modulates the "OPN system".