Melatonin promoted chemotaxins expression in lung epithelial cell stimulated with TNF-alpha

Neurological damages in COVID-19 patients: Mechanisms and preventive interventions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, causes coronavirus disease 2019 (COVID-19) which led to neurological damage and increased mortality worldwide in its second and third waves. It is associated with systemic inflammation, myocardial infarction, neurological illness including ischemic strokes (e.g., cardiac and cerebral ischemia), and even death through multi-organ failure. At the early stage, the virus infects the lung epithelial cells and is slowly transmitted to the other organs including the gastrointestinal tract, blood vessels, kidneys, heart, and brain. The neurological effect of the virus is mainly due to hypoxia-driven reactive oxygen species (ROS) and generated cytokine storm. Internalization of SARS-CoV-2 triggers ROS production and modulation of the immunological cascade which ultimately initiates the hypercoagulable state and vascular thrombosis. Suppression of immunological machinery and inhibition of ROS play an important role in neurological disturbances. So, COVID-19 associated damage to the central nervous system, patients need special care to prevent multi-organ failure at later stages of disease progression. Here in this review, we are selectively discussing these issues and possible antioxidant-based prevention therapies for COVID-19-associated neurological damage that leads to multi-organ failure.

The melatonergic pathway and its interactions in modulating respiratory system disorders

Melatonin is a key intracellular neuroimmune-endocrine regulator and coordinator of multiple complex and interrelated biological processes. The main functions of melatonin include the regulation of neuroendocrine and antioxidant system activity, blood pressure, rhythms of the sleep-wake cycle, the retardation of ageing processes, as well as reseting and optimizing mitochondria and thereby the cells of the immune system. Melatonin and its agonists have therefore been mooted as a treatment option across a wide array of medical disorders. This article reviews the role of melatonin in the regulation of respiratory system functions under normal and pathological conditions. Melatonin can normalize the structural and functional organization of damaged lung tissues, by a number of mechanisms, including the regulation of signaling molecules, oxidant status, lipid raft function, optimized mitochondrial function and reseting of the immune response over the circadian rhythm. Consequently, melatonin has potential clinical utility for bronchial asthma, chronic obstructive pulmonary disease, lung cancer, lung vascular diseases, as well as pulmonary and viral infections. The integration of melatonin's effects with the alpha 7 nicotinic receptor and the aryl hydrocarbon receptor in the regulation of mitochondrial function are proposed as a wider framework for understanding the role of melatonin across a wide array of diverse pulmonary disorders.

Associations of Herbs and Nonvitamin Dietary Supplements Use with Clinical Outcomes Among Adult and Pediatric Patients with Asthma in the United States

BACKGROUND

Herbs and nonvitamin dietary supplements (NVDS) have been commonly used among patients with asthma, yet evidence of their impact on patients' clinical outcomes is limited.

OBJECTIVE

This study examined the associations of herbs and NVDS use with asthma episodes and asthma-related emergency department (ED) visits among US adults and pediatric patients with asthma.

METHODS

A cross-sectional analysis of the 2012 National Health Interview Survey data included 2,930 US adults and 1923 children with self-reported asthma. We estimated the prevalence and type of herbs and/or NVDS use and identified factors associated with their use. We then used multivariable logistic regression models to examine the associations between these supplemental medications use and asthma outcomes, controlling for patient-related covariates. All results were weighted to represent national estimates.

RESULTS

Approximately 7.20% of American children and 21.17% of adults with asthma used herbs and/or NVDS in 2012. Herb and/or NVDS users were more likely to be female, non-Hispanic white, living in the West region, having higher family income, and having comorbidities compared with nonusers. Herbs and/or NVDS use was associated with lower likelihood of having asthma-related ED visit (adjusted odds ratio = 0.48; 95% confidence interval: 0.31, 0.75) among adult patients with asthma, but not for pediatric patients with asthma. No association between herbs and/or NVDS use and having an asthma episode was observed in either adults or children.

CONCLUSIONS

This study found high prevalence of herbs and/or NVDS use among US patients with asthma. Potential benefit of these supplemental medications use on asthma-related ED visits might exist for adult patients with asthma.

Melatonin: Possibilities for use in the treatment of asthma

Asthma is a serious health problem affecting all age groups. Melatonin or its agonists are commonly used to treat many diseases, but there are conflicting data on asthma therapy. This paper analyzes researches on the possible use of melatonin in the therapy of asthma. Melatonin is a potent antioxidant and a vasodilator, but in some experiments, it can act as a pro-oxidant and a vasoconstrictor, which may depend on the duration of use. It has been suggested that circadian rhythms should be corrected in asthmatics to optimize the desired effects of drugs and to reduce the severity of their adverse reactions. Disordered diurnal variations in the salivary levels of melatonin and cortisol are detectable in patients with asthma and may be implicated in its pathogenesis. In addition, the conflicting data on the effect of melatonin on the development of asthma are associated with an incomplete view of the factors influencing the level of melatonin. Thus, to study the effects of melatonin, it is necessary to take into account the greatest possible factors that may influence the level of melatonin and the course of asthma: a daily diet in terms of the use of caffeine, alcohol, sleep-wakefulness pattern, sleep quality proper, and drowsiness during the daytime, social burden, the level of anxiety and stress resistance, and to investigate the levels of endogenous melatonin or its derivatives, immune status, oxidative stress intensity, etc. Obviously, the use of melatonin in the therapy of asthma can be considered, by applying a personalized approach.

Melatonin and atopy: role in atopic dermatitis and asthma

Melatonin may have important immunostimulatory actions in allergic diseases, in addition to its well-known antioxidant and cytoprotective effects in several inflammatory conditions. The activation of the immune system leads to free radical production associated with decreased melatonin levels and depressed antioxidant enzyme activities in several inflammatory diseases. Many skin disorders, including atopic dermatitis, are accompanied by infiltration and activation of mast cells, which release vasoactive and proinflammatory mediators. Experimental data suggest that melatonin inhibits development of atopic eczema and reduces serum total IgE and IL-4. Allergic asthma is a condition characterized by bronchial hyperresponsiveness and the presence of IgE antibodies in response to inhaled allergens; often there is also enhanced total serum IgE levels. Melatonin regulates smooth muscle tone and influences the immune response. Melatonin may, however, act as a pro-inflammatory agent in asthma leading to bronchial constriction. The safety of melatonin as a sleep-inducing agent has been confirmed in asthmatic subjects, but its routine use is not recommended in bronchial asthma. This review summarizes what is known about the role of melatonin as an immunomodulatory agent in asthma and atopic eczema.

Leucocyte Infiltration in Lymphoid Organs and Peritoneal Cavity upon Immunization: Dependence on Circadian Rhythmicity and Melatonin 24-H Profile

Circadian rhythmicity and melatonin secretion influence many functions in mammals, including the immune system function. The aim of our study is to investigate the effect of suppression of melatonin synthesis (caused by constant lighting) on the quantity of leucocytes in immunized BALB/c mice. The mice were kept under different lighting conditions: (1) customary environmental lighting; (2) constant exposure to light; (3) exposure to light and daily melatonin treatment. The disrupted melatonin synthesis had no effect on the number of cells in the thymus, bone marrow, spleen, lymph nodes and Peyer's patches of immunized mice. However, the mice kept under constant light had an increased number of leucocytes in the peritoneal cavity when immunizations were performed in the evening. Melatonin treatment normalized the cell number. When the immunizations were performed in the morning, the numbers of cells in peritoneum of mice kept under constant lighting conditions were lower compared to mice exposed to normal lighting conditions. The number of cells of mice kept in normal light/dark conditions was significantly higher when the immunizations were performed in the morning. The number of peritoneal cells, however, did not depend on the immunization time when mice were kept under constant lighting. In conclusion, the amount of peritoneal cells in mice immunized with T cell-dependent antigens seems to be related to circadian rhythmicity, melatonin production and immunization timing.

Melatonin--a pleiotropic molecule involved in pathophysiological processes following organ transplantation

Mammals adjust their physiology in response to seasonal changes to environment (i.e. photoperiod, temperature, food availability). These changes are thought to predominantly occur for the conservation of energy during winter, by pervasive changes such as the inhibition of reproduction. Previous reports have suggested that circannual changes also occur to the immune system. In mammals, this chronological effect may be dependent on photoperiod, and evidence exists to suggest that there is a great deal of immune variation in response to light, or circadian rhythm. This is a clinically relevant, yet under-reported area of human transplantation. The aim of this review is to discuss immune variation, with specific emphasis on melatonin secretion, in the context of organ rejection, infection, neoplasia formation, and immunosuppression.

Antioxidant enzymes and melatonin levels in patients with bronchial asthma and chronic obstructive pulmonary disease during stable and exacerbation periods

An imbalance between oxidative stress and antioxidative capacity may play an important role in the development and progression of bronchial asthma (BA) and chronic obstructive pulmonary disease (COPD). We carried out a study to assess the systemic oxidant-antioxidant status during the exacerbation and the stable period in patients with BA and COPD. A total of 33 patients, 16 with BA and 17 with COPD were included in the study. During the exacerbation and the stable periods, levels of malondialdehyde (MDA), activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GRd), and catalase (CAT) in erythrocytes and serum melatonin concentrations were investigated. Blood counts, respiratory functions, and blood gases of the patients were also performed. During an exacerbation period of BA, despite the decreases in GSH-Px, GRd and melatonin levels, MDA and CAT levels, and the white blood cell count, the percentage of eosinophils were significantly higher than in the stable period. Also, it was found that FEV(1)/L (where FEV(1) is the forced expiratory volume in 1 s), FVC/L (where FVC is forced vital capacity), PEF/L/s (where PEF is peak expiratory flow), pO(2) (where pO(2) is oxygen pressure) levels increased during the stable period in patients with BA. MDA and SOD values were higher in the exacerbation period than in the stable period although GSH-Px, GRd, melatonin, pH, and pO(2) values were lower in the exacerbation period than in the stable period. The blood counts and the respiratory function tests did not change between the exacerbation and the stable period of patients with COPD significantly. In conclusion, we observed that oxidative stress in the exacerbation period of patients with BA and COPD increased whereas the antioxidant enzymes and melatonin values reduced. The episodes of BA or COPD might be associated with elevated levels of oxidative stress.

Stromal cell-derived factor-1 alpha promotes neuroprotection, angiogenesis, and mobilization/homing of bone marrow-derived cells in stroke rats

Stromal cell-derived factor (SDF)-1alpha is involved in the trafficking of hematopoietic stem cells from bone marrow to peripheral blood, and its expression is increased in the penumbra of the ischemic brain. In this study, SDF-1alpha was found to exert neuroprotective effects that rescued primary cortical cultures from H(2)O(2) neurotoxicity, and to modulate neurotrophic factor expression. Rats receiving intracerebral administration of SDF-1alpha showed less cerebral infarction due to up-regulation of antiapoptotic proteins, and they had improved motor performance. SDF-1alpha injection enhanced the targeting of bone marrow (BM)-derived cells to the injured brain, as demonstrated in green fluorescent protein-chimeric mice with cerebral ischemia. In addition, increased vascular density in the ischemic cortex of SDF-1alpha-treated rats enhanced functional local cerebral blood flow. In summary, intracerebral administration of SDF-1alpha resulted in neuroprotection against neurotoxic insult, and it induced increased BM-derived cell targeting to the ischemic brain, thereby reducing the volume of cerebral infarction and improving neural plasticity.

Enhancement of neuroplasticity through upregulation of β1-integrin in human umbilical cord-derived stromal cell implanted stroke model

Neuroplasticity subsequent to functional angiogenesis is an important goal for cell-based therapy of ischemic neural tissues. At present, the cellular and molecular mechanisms involved are still not well understood. In this study, we isolated mesenchymal stem cells (MSCs) from Wharton's jelly (WJ) to obtain clonally expanded human umbilical cord-derived mesenchymal stem cells (HUCMSCs) with multilineage differentiation potential. Experimental rats receiving intracerebral HUCMSC transplantation showed significantly improved neurological function compared to vehicle-treated control rats. Cortical neuronal activity, as evaluated by proton MR spectroscopy (1H-MRS), also increased considerably in the transplantation group. Transplanted HUCMSCs migrated towards the ischemic boundary zone and differentiated into glial, neuronal, doublecortin+, CXCR4+, and vascular endothelial cells to enhance neuroplasticity in the ischemic brain. In addition, HUCMSC transplantation promoted the formation of new vessels to increase local cortical blood flow in the ischemic hemisphere. Modulation by stem cell-derived macrophage/microglial interactions, and increased beta1-integrin expression, might enhance this angiogenic architecture within the ischemic brain. Inhibition of beta1-integrin expression blocked local angiogenesis and reduced recovery from neurological deficit. In addition, significantly increased modulation of neurotrophic factor expression was also found in the HUCMSC transplantation group. In summary, regulation of beta1-integrin expression plays a critical role in the plasticity of the ischemic brain after the implantation of HUCMSCs.

Melatonin inhibits lipopolysaccharide-induced CC chemokine subfamily gene expression in human peripheral blood mononuclear cells in a microarray analysis

Melatonin possesses a number of important biologic activities including oncostatic, anti-oxidant, and immunostimulatory actions. This study was designed to assess the effects of melatonin on inflammation-related gene expression in lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs), using CombiMatrix 2K Human Inflammation chip. After pretreatment with melatonin (100 microm) for 4 hr, cells were incubated with LPS (1 microg/mL) for 24 hr. We compared gene expression profiles between LPS-treated, melatonin-treated, LSP/melatonin-treated, and control groups. LPS induced the upregulation of 95 genes, compared with controls. Melatonin pretreatment in LPS-stimulated PBMCs suppressed the expression of 23 genes more than twofold. Interestingly, melatonin showed a suppressive effect on the expression of CC chemokine subfamily genes, including CCL2/MCP1, CCL3/MIP1 alpha, CCL4/MIP1 beta, CCL5/RANTES, CCL8/MCP2, CCL20/MDC, and CCL22/MIP3 alpha, in LPS-stimulated PBMCs. This result was confirmed by reverse transcriptase polymerase chain reaction. Among the CC chemokine subfamily genes, particularly, the expression of CCL2 and CCL5 was markedly downregulated by melatonin in LPS-stimulated PBMCs. The secretion levels of CCL2 and CCL5 were measured using enzyme-linked immunosorbent assay. Stimulation of PBMCs by LPS induced the secretion of CCL2 (2334.3 +/- 161.4 pg/mL, mean +/- S.E.M.), whereas melatonin pretreatment (153.0 +/- 3.8 pg/mL) inhibited the LPS-induced secretion of CCL2. Melatonin pretreatment (2696.2 +/- 385.3 pg/mL) also inhibited the LPS-induced secretion of CCL5 (4679.6 +/- 107.5 pg/mL). Taken together, these results suggest that melatonin may have a suppressive effect on LPS-induced expression of CC chemokine genes, especially CCL2 and CCL5, which may explain its beneficial effects in the treatment of various inflammatory conditions.

High glucose upregulates connective tissue growth factor expression in human vascular smooth muscle cells

Background

Connective tissue growth factor (CTGF) is a potent profibrotic factor, which is implicated in fibroblast proliferation, angiogenesis and extracellular matrix (ECM) synthesis. It is a downstream mediator of some of the effects of transforming growth factor β (TGFβ) and is potentially induced by hyperglycemia in human renal mesangial cells. However, whether high glucose could induce the CTGF expression in vascular smooth muscle cells (VSMCs) remains unknown. Therefore, this study was designed to test whether high glucose could regulate CTGF expression in human VSMC. The effect of modulating CTGF expression on VSMC proliferation and migration was further investigated.

Results

Expression of CTGF mRNA was up-regulated as early as 6 hours in cultured human VSMCs after exposed to high glucose condition, followed by ECM components (collagen type I and fibronectin) accumulation. The upregulation of CTGF mRNA appears to be TGFβ-dependent since anti-TGFβ antibody blocks the effect of high glucose on CTGF gene expression. A small interference RNA (siRNA) targeting CTGF mRNA (CTGF-siRNA) effectively suppressed CTGF up-regulation stimulated by high glucose up to 79% inhibition. As a consequence of decreased expression of CTGF gene, the deposition of ECM proteins in the VSMC was also declined. Moreover, CTGF-siRNA expressing vector partially inhibited the high glucose-induced VSMC proliferation and migration.

Conclusion

Our data suggest that in the development of macrovascular complications in diabetes, CTGF might be an important factor involved in the patho-physiological responses to high glucose in human VSMCs. In addition, the modulatory effects of CTGF-siRNA during this process suggest that specific targeting CTGF by RNA interference could be useful in preventing intimal hyperplasia in diabetic macrovascular complications.

Intracerebral peripheral blood stem cell (CD34+) implantation induces neuroplasticity by enhancing beta1 integrin-mediated angiogenesis in chronic stroke rats

Although stem cell-based treatments for stroke and other neurodegenerative diseases have advanced rapidly, there are still few clinical treatments available. In this study, rats receiving intracerebral peripheral blood hematopoietic stem cell (CD34+) (PBSC) transplantation showed much more improvement in neurological function after chronic cerebral ischemia in comparison with vehicle-treated control rats. Using laser-scanning confocal microscopy, implanted PBSCs were seen to differentiate into glial cells [GFAP+ (glial fibrillary acidic protein-positive)], neurons [Nestin+, MAP-2+ (microtubule-associated protein 2-positive), Neu-N+ (neuronal nuclear antigen-positive)], and vascular endothelial cells [vWF+ (von Willebrand factor-positive)], thereby enhancing neuroplastic effects in the ischemic brain. Cortical neuronal activity, as evaluated by 1H-MRS (proton magnetic resonance spectroscopy), also increased considerably in PBSC-treated rats compared with a vehicle-treated control group. In addition, PBSC implantation promoted the formation of new vessels, thereby increasing the local cortical blood flow in the ischemic hemisphere. These observations may be explained by the involvement of stem cell-derived macrophage/microglial cells, and beta1 integrin expression, which might enhance this angiogenic architecture over the ischemic brain. Furthermore, quantitative reverse transcription-PCR analysis showed significantly increased modulation of neurotrophic factor expression in the ischemic hemisphere of the PBSC-transplanted rats compared with vehicle-treated control rats. Thus, intracerebral PBSC transplantation might have potential as a therapeutic strategy for treating cerebrovascular diseases.

Hypoxia-inducible transcription factor-1alpha promotes hypoxia-induced A549 apoptosis via a mechanism that involves the glycolysis pathway

Background

Hypoxia-inducible transcription factor-1α (HIF-1α), which plays an important role in controlling the hypoxia-induced glycolysis pathway, is a "master" gene in the tissue hypoxia response during tumor development. However, its role in the apoptosis of non-small cell lung cancer remains unknown. Here, we have studied the effects of HIF-1α on apoptosis by modulating HIF-1α gene expression in A549 cells through both siRNA knock-down and over-expression.

Methods

A549 cells were transfected with a HIF-1α siRNA plasmid or a HIF-1α expression vector. Transfected cells were exposed to a normoxic or hypoxic environment in the presence or absence of 25 mM HEPES and 2-deoxyglucose (2-DG) (5 mM). The expression of three key genes of the glycolysis pathway, glucose transporter type 1(GLUT1), phosphoglycerate kinase 1(PGK1), and hexokinase 1(HK1), were measured using real-time RT-PCR. Glycolysis was monitored by measuring changes of pH and lactate concentration in the culture medium. Apoptosis was detected by TUNEL assay and flow cytometry.

Results

Knocking down expression of HIF-1α inhibited the glycolysis pathway, increased the pH of the culture medium, and protected the cells from hypoxia-induced apoptosis. In contrast, over-expression of HIF-1α accelerated glycolysis in A549 cells, decreased the pH of the culture medium, and enhanced hypoxia-induced apoptosis. These effects of HIF-1α on glycolysis, pH of the medium, and apoptosis were reversed by treatment with the glycolytic inhibitor, 2-DG. Apoptosis induced by HIF-1α over-expression was partially inhibited by increasing the buffering capacity of the culture medium by adding HEPES.

Conclusion

During hypoxia in A549 cells, HIF-1α promotes activity of the glycolysis pathway and decreases the pH of the culture medium, resulting in increased cellular apoptosis.