Arterial pulse wave velocity, an established index of arterial distensibility, was measured together with arterial pressure in a group of 524 normal subjects of both sexes 2 months to 94 years old (mean age 45.6 +/- 15.3 years [SD]) in rural Guangzhou, China, an area with known low prevalence of hypertension. Fasting serum lipid levels and overnight Na+ and K+ urinary excretion levels were determined in a subgroup of 104 subjects (ages 8 to 88 years). Comparisons were made with data obtained similarly from normal subjects in urban Beijing, an area with known high prevalence of hypertension. Serum cholesterol levels were similar and low in each group (Guangzhou, 4.34 +/- 0.12 mmol/liter [SE]; BEijing, 4.49 +/- 0.11 mmol/liter). Prevalence of hypertension (WHO criteria) was 4.9% (Guangzhou) and 15.6% (Beijing). In Guangzhou subjects pulse wave velocity was consistently lower in the aorta, arm, and leg, and increased to a lesser degree with age compared with Beijing subjects. Regression equations (x = pulse wave velocity [cm/sec], y = age [years]) were as follows: (1) aorta, Guangzhou: y = 5.1x + 533, r = .552, p less than .05; Beijing: y = 9.2x + 615, r = .673, p less than .001; (2) arm, Guangzhou: y = 0.61x + 817, r = .121, p less than .05; Beijing: y = 4.8x + 998, r = .453, p less than .001; (3) leg, Guangzhou: y = 4.43x + 718, r = .512, p less than .05; Beijing: y = 5.6x + 791, r = .630, p less than .001.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of aging on arterial distensibility in populations with high and low prevalence of hypertension: comparison between urban and rural communities in China.

https://repositorio.uca.edu.ar/bitstream/123456789/1653/1/melatonin-pleiotropic-orchestrating-regulator-molecule.pdf

Melatonin—A pleiotropic, orchestrating regulator molecule

Dysregulated inflammation is a central pathological process in diverse disease states. Traditionally, therapeutic approaches have sought to modulate the pro- or anti-inflammatory limbs of inflammation, with mixed success. However, insight into the pathways by which inflammation is resolved has highlighted novel opportunities to pharmacologically manipulate these processes - a strategy that might represent a complementary (and perhaps even superior) therapeutic approach. This Review discusses the state of the art in the biology of resolution of inflammation, highlighting the opportunities and challenges for translational research in this field.

/pdf/resolution-of-inflammation-a-new-therapeutic-frontier-1w8p8g62e7.pdf

Resolution of inflammation: a new therapeutic frontier.

Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed.

/pdf/melatonin-buffering-the-immune-system-1mr2908lga.pdf

Melatonin: buffering the immune system.

COVID-19: Melatonin as a potential adjuvant treatment.

Background and Purpose

Acute lung injury (ALI) is a severe illness with a high rate of mortality. Maresin 1 (MaR1) was recently reported to regulate inflammatory responses. We used a LPS-induced ALI model to determine whether MaR1 can mitigate lung injury.



Experimental Approach

Male BALB/c mice were injected, intratracheally, with either LPS (3 mg·kg−1) or normal saline (1.5 mL·kg−1). After this, normal saline, a low dose of MaR1 (0.1 ng per mouse) or a high dose of MaR1 (1 ng per mouse) was given i.v. Lung injury was evaluated by detecting arterial blood gas, pathohistological examination, pulmonary oedema, inflammatory cell infiltration, inflammatory cytokines in the bronchoalveolar lavage fluid and neutrophil–platelet interactions.



Key Results

The high dose of MaR1 significantly inhibited LPS-induced ALI by restoring oxygenation, attenuating pulmonary oedema and mitigating pathohistological changes. A combination of elisa and immunohistochemistry showed that high-dose MaR1 attenuated LPS-induced increases in pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), chemokines [keratinocyte chemokine, monocyte chemoattractant protein-5, macrophage inflammatory protein (MIP)-1α and MIP-1γ], pulmonary myeloperoxidase activity and neutrophil infiltration in the lung tissues. Consistent with these observations, flow cytometry and Western blotting indicated that MaR1 down-regulated LPS-induced neutrophil adhesions and suppressed the expression of intercellular adhesion molecule (ICAM)-1, P-selection and CD24.



Conclusions and Implications

High-dose MaR1 mitigated LPS-induced lung injury in mice by inhibiting neutrophil adhesions and decreasing the levels of pro-inflammatory cytokines.

https://bpspubs.onlinelibrary.wiley.com/doi/pdf/10.1111/bph.12714

Maresin 1 mitigates LPS-induced acute lung injury in mice

BACKGROUND Treatment with melatonin significantly reduces lung injury induced by bleomycin, paraquat and ischemia reperfusion. In the present study, we investigated the possible protective roles of melatonin in pulmonary inflammation and lung injury during acute endotoxemia. METHODS Thirty-two male Sprague-Dawley rats were randomly assigned to four groups: vehicle + saline group, melatonin + saline group, vehicle + lipopolysaccharide group, melatonin + lipopolysaccharide group. The rats were treated with melatonin (10 mg/kg, intraperitoneal injection (i.p.)) or vehicle (1% ethanol saline), 30 minutes prior to lipopolysaccharide administration (6 mg/kg, intravenous injection). Four hours after lipopolysaccharide injection, samples of pulmonary tissue were collected. Blood gas analysis was carried out. Optical microscopy was performed to examine pathological changes in lungs and lung injury score was assessed. Wet/dry ratios (W/D), myeloperoxidase activity, malondialdehyde concentrations and tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) levels in lungs were measured. The pulmonary expression of nuclear factor-kappa B (NF-kappaB) p65 was evaluated by Western blotting. RESULTS PaO(2) in the vehicle + lipopolysaccharide group decreased compared with that in the vehicle + saline group. This decrease was significantly reduced in the melatonin + lipopolysaccharide group. The lung tissues from the saline + lipopolysaccharide group were significantly damaged, which were less pronounced in the melatonin + lipopolysaccharide group. The W/D ratio increased significantly in the vehicle + lipopolysaccharide group (6.1 +/- 0.18) as compared with that in the vehicle + saline group (3.61 +/- 0.3) (P < 0.01), which was significantly reduced in the melatonin + lipopolysaccharide group (4.8 +/- 0.25) (P < 0.01). Myeloperoxidase activity and malondialdehyde levels increased significantly in the vehicle + lipopolysaccharide group compared with that in the vehicle + saline group, which was reduced in the melatonin + lipopolysaccharide group. The TNF-alpha level of pulmonary tissue increased significantly in the vehicle + lipopolysaccharide group ((8.7 +/- 0.91) pg/mg protein) compared with that in the vehicle + saline group ((4.3 +/- 0.62) pg/mg protein, P < 0.01). However, the increase of TNF-alpha level of pulmonary tissue was significantly reduced in the melatonin + lipopolysaccharide group ((5.9 +/- 0.56) pg/mg protein, P < 0.01). Pulmonary IL-10 levels were elevated markedly in the vehicle + lipopolysaccharide group in contrast to that in the vehicle + saline group, whereas the elevation was augmented in the melatonin + lipopolysaccharide group. The nuclear localization of p65 increased markedly in the vehicle + lipopolysaccharide group and this enhancement of nuclear p65 expression was much less in the melatonin + lipopolysaccharide group. CONCLUSION Melatonin reduces acute lung injury in endotoxemic rats by attenuating pulmonary inflammation and inhibiting NF-kappaB activation.

Melatonin reduces acute lung injury in endotoxemic rats.

Acute lung injury (ALI) is characterized by lung inflammation and diffuse infiltration of neutrophils. Neutrophil apoptosis is recognized as an important control point in the resolution of inflammation. Maresin 1 (MaR1) is a new docosahexaenoic acid-derived proresolving agent that promotes the resolution of inflammation. However, its function in neutrophil apoptosis is unknown. In this study, isolated human neutrophils were incubated with MaR1, the pan-caspase inhibitor z-VAD-fmk, and lipopolysaccharide (LPS) to determine the mechanism of neutrophil apoptosis. Acute lung injury was induced by intratracheal instillation of LPS. In addition, mice were treated with MaR1 intravenously at the peak of inflammation and administered z-VAD-fmk intraperitoneally. We found that culture of isolated human neutrophils with LPS dramatically delayed neutrophil apoptosis through the phosphorylation of AKT, ERK, and p38 to upregulate the expression of the antiapoptotic proteins Mcl-1 and Bcl-2, which was blocked by pretreatment with MaR1 in vitro. In mice, MaR1 accelerated the resolution of inflammation in LPS-induced ALI through attenuation of neutrophil accumulation, pathohistological changes, and pulmonary edema. Maresin 1 promoted resolution of inflammation by accelerating caspase-dependent neutrophil apoptosis. Moreover, MaR1 also reduced the LPS-induced production of proinflammatory cytokines and upregulated the production of the anti-inflammatory cytokine interleukin-10. In contrast, treatment with z-VAD-fmk inhibited the proapoptotic action of MaR1 and attenuated the protective effects of MaR1 in LPS-induced ALI. Taken together, MaR1 promotes the resolution of LPS-induced ALI by overcoming LPS-mediated suppression of neutrophil apoptosis.

Maresin 1 prevents lipopolysaccharide-induced neutrophil survival and accelerates resolution of acute lung injury.

BML-111 attenuates hemorrhagic shock-induced acute lung injury through inhibiting activation of mitogen-activated protein kinase pathway in rats.

Mechanical ventilation can cause structural and functional disturbances in the lung termed ventilator-induced lung injury (VILI). The aim of this study was to evaluate whether BML-111, a lipoxin receptor agonist, could attenuate VILI. Following induction of anesthesia and tracheostomy, Sprague-Dawley rats were ventilated with low tidal volume (6 mL/kg) or high tidal volume (20 mL/kg, HVT) for 4 h. Some rats subjected to HVT ventilation received BML-111 or vehicle (saline) by intraperitoneal injection. Some rats subjected to HVT and BML-111(1 mg/kg) received BOC-2 (a FPR2/ALX antagonist) intraperitoneally 30 min before BML-111. Sham rats were tracheotomized without ventilation. Treatment with BML-111 attenuated VILI, as evidenced by improved oxygenation and reduced histological injury compared with HVT-induced lung injury. BML-111 decreased indices of inflammation such as interleukin 1β, interleukin 6, tumor necrosis factor α, and bronchoalveolar lavage neutrophil infiltration. Administration with BML-111 suppressed the decrement of the nuclear factor κB (NF-κB) inhibitor IκB-α, diminished NF-κB activation, and reduced activation of mitogen-activated protein kinase in VILI. This study indicates that BML-111 attenuated VILI via a NF-κB and mitogen-activated protein kinase dependent mechanism. BML-111 may be a promising strategy for alleviation of VILI in patients subjected to mechanical ventilation.

Zhou-Yang Wu

Papers

Maresin 1 mitigates LPS-induced acute lung injury in mice

Melatonin reduces acute lung injury in endotoxemic rats.

Maresin 1 prevents lipopolysaccharide-induced neutrophil survival and accelerates resolution of acute lung injury.

BML-111 attenuates hemorrhagic shock-induced acute lung injury through inhibiting activation of mitogen-activated protein kinase pathway in rats.

BML-111, a lipoxin receptor agonist, attenuates ventilator-induced lung injury in rats.