Tumor necrosis factor alpha has a crucial role in increased reactive oxygen species production in platelets of mice injected with lipopolysaccharide

Tumor necrosis factor alpha induces NOX2-dependent reactive oxygen species production in hypothalamic paraventricular nucleus neurons following angiotensin II infusion

There is evidence that tumor necrosis factor alpha (TNFα) influences autonomic processes coordinated within the hypothalamic paraventricular nucleus (PVN), however, the signaling mechanisms subserving TNFα's actions in this brain area are unclear. In non-neuronal cell types, TNFα has been shown to play an important role in canonical NADPH oxidase (NOX2)-mediated production of reactive oxygen species (ROS), molecules also known to be critically involved in hypertension. However, little is known about the role of TNFα in NOX2-dependent ROS production in the PVN within the context of hypertension. Using dual labeling immunoelectron microscopy and dihydroethidium (DHE) microfluorography, we provide structural and functional evidence for interactions between TNFα and NOX2 in the PVN. The TNFα type 1 receptor (TNFR1), the major mediator of TNFα signaling in the PVN, was commonly co-localized with the catalytic gp91phox subunit of NOX2 in postsynaptic sites of PVN neurons. Additionally, there was an increase in dual labeled dendritic profiles following fourteen-day slow-pressor angiotensin II (AngII) infusion. Using DHE microfluorography, it was also shown that TNFα application resulted in a NOX2-dependent increase in ROS in isolated PVN neurons projecting to the spinal cord. Further, TNFα-mediated ROS production was heightened after AngII infusion. The finding that TNFR1 and gp91phox are positioned for rapid interactions, particularly in PVN-spinal cord projection neurons, provides a molecular substrate by which inflammatory signaling and oxidative stress may jointly contribute to AngII hypertension.

Melatonin alleviates 3,3',4,4',5-pentachlorobenzene induced colon injury by relieving oxidative stress

3,3',4,4',5-pentachlorobiphenyl (PCB126) is widely distributed, non-degradable and bioaccumulative, which can affect the function of tissues and organs of the living organisms. Melatonin (MT) is a sort of indole neurohormone that is mainly secreted by the pineal gland. Numerous studies have shown that MT can alleviate intestinal injury through various mechanisms such as antioxidant, anti-inflammatory, and anti-apoptosis. For the above reasons, the aim of this study is to explore the mechanism of intestinal injury in mice after exposure to PCB126 as well as the antagonistic effect of MT. Mice were respectively fed PCB126 (0.326 mg/kg) and/or MT (10 mg/kg) in vivo. In vitro, colonic epithelial cells (MCEC) were treated with PCB126 (150 μM) and/or MT (2 mM). We found that the microscopic structure of colon tissue was impaired after exposure to PCB126. The levels of oxidative stress, the protein and mRNA levels of expression of inflammatory related factors were significantly increased and the expression levels of intestinal tight junction protein were decreased. Notably, MT can promote Nrf2/HO-1 expression level and reduce the colonic injury caused by PCB126. Further in vitro treatment with reactive oxygen species inhibitors (NAC) showed that it significantly alleviated PCB126-induced in MCEC cell damage. In summary, the above results suggested that MT alleviates PCB126-induced colon inflammation by inhibiting the overproduction of reactive oxygen species (ROS) and up-regulating the expression level of intestinal tight junction protein. Our results contribute to the further comprehension of the intestinal toxicity effects of PCB126 and the significant role of MT in preserving the mechanisms of intestinal injury.

Portal Vein Thrombosis in Patients with Liver Cirrhosis: What Went Wrong?

Purpose

This study aimed to explore inflammatory biomarkers, stool's functional bacterial groups and their possible link to portal vein thrombosis (PVT) in patients with liver cirrhosis (LC).

Materials and Methods

An observational study of 300 participants: 200 inhospital cirrhotic patients, who met inclusion criteria, equally assigned into two groups, based on the presence or absence of PVT and 100 healthy controls was carried out.

Results

The PVT group displayed significant differences related to older age, cigarettes smoking history, emergency admission, higher Child-Pugh score, metabolic related disorders and nonalcoholic fatty liver disease, as well as non-obstructive aspects, with chronic thrombi. The PVT group exhibited significant differences related to biomarkers such as tumor necrosis factor (TNF)-alpha, C-reactive protein (CRP), D-dimers (D-D), as well as gut overall dysbiosis (DB) and alteration of different functional bacterial groups of the gut microbiota. Strong positive correlations were observed between PVT severity, and TNF-alpha, CRP, D-D as well as lipopolysaccharide (LPS) positive bacteria. Esophageal varices, age and abdominal pain were independent predictors for PVT severity as well as CRP, TNF-alpha and D-D.

Conclusion

Patients with LC and PVT displayed elevation of TNF-alpha, CRP, D-D alterations of the functional gut microbiota, as well as several morphological and clinical particularities. Although the LPS positive gut microbiota was linked to inflammatory biomarkers and PVT severity, it was not proven to be an independent predictor of the PVT severity like CRP, TNF-alpha and D-D.

An Insight into Platelets at Older Age: Cellular and Clinical Perspectives

Higher access to medical care, advanced diagnostic tools, and overall public health improvements have favored increased humans lifespan. With a growing proportion of older adults, the associated costs to care for ageing-associated conditions will continue to grow. This chapter highlights recent cellular and clinical evidence of platelets at an older age, from the hyperreactive phenotype associated with thrombosis to the well-known hallmarks of ageing identifiable in platelets and their potential functional implications on platelets at an older age. Therefore, it is imperative to understand platelets' molecular and cellular mechanisms during ageing in health and disease. New knowledge will favor the development of new ways to prevent some of the age-associated complications where platelets are key players.

Palmatine Derivatives as Potential Antiplatelet Aggregation Agents via Protein Kinase G/Vasodilator-Stimulated Phosphoprotein and Phosphatidylinositol 3-Kinase/Akt Phosphorylation

Sixty palmatine (PMT) derivatives were synthesized and evaluated for antiplatelet aggregation taking berberine as the lead, and the structure-activity relationship was first systematically described. Among them, compound 2v showed the best potency in reducing adenosine diphosphate (ADP)-induced platelet aggregation in a dose-dependent manner. It greatly suppressed ADP-induced platelet aggregation, activation, and Akt phosphorylation in vitro and ex vivo after oral administration to mice. It also effectively inhibited carrageenan-induced thrombus formation in the mouse tail and lung, as well as reduced the serum P-selectin level. Compound 2v might simultaneously bind to protein kinase G to improve vasodilator-stimulated phosphoprotein phosphorylation and bind to phosphatidylinositol 3-kinase to inhibit Akt phosphorylation, which synergically reduced platelet aggregation, thereby achieving antithrombotic efficacy. Therefore, PMT derivatives constituted a novel family of antiplatelet aggregation agents with the advantage of a good safety profile, worthy of further investigation.

Tanreqing Injection Regulates Cell Function of Hypoxia-Induced Human Pulmonary Artery Smooth Muscle Cells (HPASMCs) through TRPC1/CX3CL1 Signaling Pathway

Hypoxia-induced pulmonary arterial hypertension (HPAH) is due to hypoxia caused by vascular endothelial cell remolding and damage. Previous studies have suggested that CX3CL1 plays an important role in HPAH which is affected by oxidative stress. Ca²⁺ channel activation correlated with increasing NF-κB levels induced by ROS. Tanreqing injection (TRQ) is a traditional Chinese medicine (TCM) for acute upper respiratory tract infection and acute pneumonia. In the present study, we explored the effect of TRQ on human pulmonary artery smooth muscle cells (HPASMCs) undergoing hypoxia and feasible molecular mechanisms involved in. Cell proliferation was assayed using CCK8 kits. Immunofluorescence and western blotting along with ELISA assay were performed to investigate the effect of TRQ on hypoxia-induced ROS, Ca²⁺, hydroxyl free radicals, and the expression of Ca²⁺ channel protein TRPC1, CX3CR1, HIF-1α, NF-κBp65, and p-NF-κBp65 in HPASMCs. Human CX3CL1 and the inhibitor of TRPC1 as SKF96365 were used for further investigation. TRQ inhibited hypoxia-induced increasing cell adhesion, ROS, Ca²⁺, hydroxyl free radicals, CX3CR1, HIF-1α, NF-κBp65 activation, and even on TRPC1 expression in HPASMC which tended to be attenuated even reversed by CX3CL1. Our results suggested that TRQ might help to attenuate remodeling of HPASMC through inhibiting the ROS and TRPC1/CX3CL1 signaling pathway.

Clotting Dysfunction in Sepsis: A Role for ROS and Potential for Therapeutic Intervention

Sepsis is regarded as one of the main causes of death among the critically ill. Pathogen infection results in a host-mediated pro-inflammatory response to fight infection; as part of this response, significant endogenous reactive oxygen (ROS) and nitrogen species (RNS) production occurs, instigated by a variety of sources, including activated inflammatory cells, such as neutrophils, platelets, and cells from the vascular endothelium. Inflammation can become an inappropriate self-sustaining and expansive process, resulting in sepsis. Patients with sepsis often exhibit loss of aspects of normal vascular homeostatic control, resulting in abnormal coagulation events and the development of disseminated intravascular coagulation. Diagnosis and treatment of sepsis remain a significant challenge for healthcare providers globally. Targeting the drivers of excessive oxidative/nitrosative stress using antioxidant treatments might be a therapeutic option. This review focuses on the association between excessive oxidative/nitrosative stress, a common feature in sepsis, and loss of homeostatic control at the level of the vasculature. The literature relating to potential antioxidants is also described.

What Function Do Platelets Play in Inflammation and Bacterial and Viral Infections?

The article presents the function of platelets in inflammation as well as in bacterial and viral infections, which are the result of their reaction with the endovascular environment, including cells of damaged vascular endothelium and cells of the immune system. This role of platelets is conditioned by biologically active substances present in their granules and in their specific structures - EV (extracellular vesicles).

Platelet Behavior Contributes to Neuropathologies: A Focus on Alzheimer's and Parkinson's Disease

The functions of platelets are broad. Platelets function in hemostasis and thrombosis, inflammation and immune responses, vascular regulation, and host defense against invading pathogens, among others. These actions are achieved through the release of a wide set of coagulative, vascular, inflammatory, and other factors as well as diverse cell surface receptors involved in the same activities. As active participants in these physiological processes, platelets become involved in signaling pathways and pathological reactions that contribute to diseases that are defined by inflammation (including by pathogen-derived stimuli), vascular dysfunction, and coagulation. These diseases include Alzheimer's and Parkinson's disease, the two most common neurodegenerative diseases. Despite their unique pathological and clinical features, significant shared pathological processes exist between these two conditions, particularly relating to a central inflammatory mechanism involving both neuroinflammation and inflammation in the systemic environment, but also neurovascular dysfunction and coagulopathy, processes which also share initiation factors and receptors. This triad of dysfunction-(neuro)inflammation, neurovascular dysfunction, and hypercoagulation-illustrates the important roles platelets play in neuropathology. Although some mechanisms are understudied in Alzheimer's and Parkinson's disease, a strong case can be made for the relevance of platelets in neurodegeneration-related processes.

Cannabinoid Receptor 2 Agonism is Capable of Preventing Lipopolysaccharide Induced Decreases of Cochlear Microcirculation - A Potential Approach for Inner Ear Pathologies

HYPOTHESIS

The ability of JWH-133, an agonist at the cannabinoid receptor 2, to abrogate the effects of lipopolysaccharide on cochlear microcirculation was investigated.

BACKGROUND

Cochlear inflammation and subsequent impairment of microcirculation is part of numerous pathologies affecting inner ear function, including suppurative labyrinthitis, noise trauma, and sudden sensorineural hearing loss. One way of causing cochlear inflammation is exposing the cochlea to lipopolysaccharide, a bacterial endotoxin.

METHODS

Twenty Dunkin-hartley guinea pigs were divided into four groups of five animals each. Two groups received topic treatment with JWH-133 and two received treatment with placebo. One group that had been treated with JWH-133 and one with placebo were then exposed to lipopolysaccharide or placebo, respectively. Cochlear microcirculation was quantified before, in between and after treatments by in vivo fluorescence microscopy.

RESULTS

Significantly different changes in cochlear blood flow were only seen in the group that was treated with placebo and subsequently lipopolysaccharide. Every other group showed no significant change in cochlear blood flow.

CONCLUSION

JWH-133 is capable of abrogating the effects of lipopolysaccharide on cochlear microcirculation. It may therefore be clinical interest in treating numerous inflammation associated cochlear pathologies.

Investigation on the mechanisms of guiqi huoxue capsule for treating cervical spondylosis based on network pharmacology and molecular docking

BACKGROUND

Guiqi huoxue capsule (GQHXC) is a patented Chinese medicine used for treating a liver and kidney deficiency and blood stasis syndrome due to qi deficiency. It is caused by cervical spondylosis (cervical spondylotic radiculopathy (CSR), mixed cervical spondylosis mainly composed of nerve root type). Its underlying mechanisms need, however, to be further clarified.

METHODS

In this study, collecting compounds, predicting therapeutic targets, constructing networks, and analyzing biological functions and pathways were based on network pharmacology analysis. In addition, molecular docking verification was engaged to assess the binding potential of selected target-compound pairs.

RESULTS

We established 5 networks: compound-putative target network of GQHXC, protein-protein interaction (PPI) network related to CSR, compound-CSR target network, potential therapeutic targets PPI network, and herb-compound-target-pathway network. Network analysis indicated that 7 targets (tumor necrosis factor [TNF], interleukin 6 [IL6], nitric oxide synthase 3 [NOS3], Interleukin-8 [CXCL8], prostaglandin-endoperoxide synthase 2 [PTGS2], vascular endothelial growth factor A [VEGFA], and AP-1 transcription factor subunit [JUN]) might be the therapeutic targets of GQHXC in CSR. Moreover, molecular docking verification showed that TNF, IL6, NOS3, CXCL8, PTGS2, VEGFA, and JUN had a good is interaction with the corresponding compounds. Furthermore, enrichment analysis indicated that GQHXC might exert a curative role in CSR by regulating some important pathways, such as TNF signaling pathway, NF-kappa B signaling pathway, AGE-RAGE signaling pathway in diabetic complications, and so on.

CONCLUSION

Our study preliminarily explained the underlying mechanisms of GQHXC for treating CSR, and molecular docking verification was adopted as an additional verification. These findings laid a valuable foundation for experimental research and further application of GQHXC in the clinical treatment of CSR.

Epigenetic code during mycobacterial infections: therapeutic implications for tuberculosis

Epigenetics involves changing the gene function without any change in the sequence of the genes. In the case of tuberculosis (TB) infections, the bacilli, Mycobacterium tuberculosis (M.tb), uses epigenetics as a tool to protect itself from the host immune system. TB is a deadly disease-causing maximum death per year due to a single infectious agent. In the case of TB, there is an urgent need for novel host-directed therapies which can effectively target the survival and long-term persistence of the bacteria without developing drug resistance in the bacterial strains while also reducing the duration and toxicity associated with the mainstream anti-TB drugs. Recent studies have suggested that TB infection has a significant effect on the host epigenome thereby manipulating the host immune response in the favor of the pathogen. M.tb alters the activation status of key genes involved in the immune response against TB to promote its survival and subvert the antibacterial strategies of the host. These changes are reversible and can be exploited to design very efficient host-directed therapies to fight against TB. This review has been written with the purpose of discussing the role of epigenetic changes in TB pathogenesis and the therapeutic approaches involving epigenetics, which can be utilized for targeting the pathogen.

Exploring the Molecular Mechanism of Cinnamic Acid-Mediated Cytotoxicity in Triple Negative MDA-MB-231 Breast Cancer Cells

BACKGROUND

Cinnamic Acid (CA), also known as 3-phenyl-2-propenoic acid, is a naturally occurring aromatic fatty acid found commonly in cinnamon, grapes, tea, cocoa, spinach and celery. Various studies have identified CA to have anti-proliferative action on glioblastoma, melanoma, prostate and lung carcinoma cells.

OBJECTIVE

Our objective was to investigate the molecular mechanism underlying the cytotoxic effect of CA in killing MDA-MB-231 triple negative breast cancer cells.

METHODS

We performed MTT assay and trypan blue assay to determine cell viability and cell death, respectively. Comet analysis was carried out to investigate DNA damage of individual cells. Furthermore, AO/EtBr assay and sub-G1 analysis using flow cytometry were used to study apoptosis. Protein isolation followed by immunoblotting was used to observe protein abundance in treated and untreated cancer cells.

RESULTS

Using MTT assay, we have determined CA to reduce cell viability in MDA-MB-231 breast cancer cells and tumorigenic HEK 293 cells but not in normal NIH3T3 fibroblast cells. Subsequently, trypan blue assay and comet assay showed CA to cause cell death and DNA damage, respectively, in the MDA-MB-231 cells. Using AO/EtBr staining and sub-G1 analysis, we further established CA to increase apoptosis. Additionally, immunoblotting showed the abundance of TNFA, TNF Receptor 1 (TNFR1) and cleaved caspase-8/-3 proapoptotic proteins to increase with CA treatment. Subsequently, blocking of TNFA-TNFR1 signalling by small molecule inhibitor, R-7050, reduced the expression of cleaved caspase-8 and caspase-3 at the protein level.

CONCLUSION

Thus, from the above observations, we can conclude that CA is an effective anticancer agent that can induce apoptosis in breast cancer cells via TNFA-TNFR1 mediated extrinsic apoptotic pathway.

Lipopolysaccharide decreases cochlear blood flow dose dependently in a guinea pig animal model via TNF signaling

OBJECTIVE

To evaluate the effect of Lipopolysaccharide (LPS), a bacterial endotoxin on cochlear microcirculation, and its mode of action.

METHODS

Twenty-five Dunkin-Hartley guinea pigs were divided into five groups of five animals each. After surgical preparation, cochlear microcirculation was quantified by in vivo fluorescence microscopy. Placebo or LPS (1 mg, 10 µg, and 100 ng) was applied topically, and microcirculation was measured before and twice after application. A fifth group was pretreated with etanercept, a tumor necrosis factor (TNF) antagonist, and afterward the lowest LPS concentrations that yielded significant results (10 µg) were applied.

RESULTS

In the groups that had been treated with 1 mg and 10 µg LPS, a significant drop in cochlear microcirculation was observed after 30 (.791 ± .089 Arbitrary Units (AU), compared to baseline, and .888 ± .071AU) and 60 (.756 ± .101 AU and .817 ± .124 AU, respectively) minutes. The groups that had been treated with 100 ng LPS and that had been pretreated with etanercept showed no significant change in cochlear blood flow compared to placebo.

CONCLUSION

Lipopolysaccharide shows a dose-dependent effect on cochlear microcirculation; this effect can already be observed after 30 min. Pretreatment with etanercept can abrogate this effect, indicating that TNF mediates the effect of LPS on cochlear microcirculation.

Host Epigenetics in Intracellular Pathogen Infections

Some intracellular pathogens are able to avoid the defense mechanisms contributing to host epigenetic modifications. These changes trigger alterations tothe chromatin structure and on the transcriptional level of genes involved in the pathogenesis of many bacterial diseases. In this way, pathogens manipulate the host cell for their own survival. The better understanding of epigenetic consequences in bacterial infection may open the door for designing new vaccine approaches and therapeutic implications. This article characterizes selected intracellular bacterial pathogens, including Mycobacterium spp., Listeria spp., Chlamydia spp., Mycoplasma spp., Rickettsia spp., Legionella spp. and Yersinia spp., which can modulate and reprogram of defense genes in host innate immune cells.

Anti-inflammatory and antixidant properties of blend formulated with compounds of Malpighia emarginata D.C (acerola) and Camellia sinensis L. (green tea) in lipopolysaccharide-stimulated RAW 264.7 macrophages

The antioxidant and anti-inflammatory properties of Malpighia emarginata D.C (acerola) and Camellia sinensis L. (green tea) have been studied, particularly as an alternative in medicinal approach for different physio pathological conditions. Here we develop an powder blend formulated with both Malpighia emarginata D.C and Camellia sinensis L. which have in the composition higher content of ascorbic acid and epigallatocathechin-3-gallate respectively. Using different conditions for microencapsulation of biocompounds, we performed the powder production through spray-drying process. After, we evaluate the antioxidant and anti-inflammatory properties of blends formulated with Malpighia emarginata D.C and Camellia sinensis L. in an in vitro model of inflammation, using LPS-stimulated RAW-264.7 macrophage cell line. We observed that co-treatment with blends was able to modulate the redox parameters in cells during the in vitro inflammatory response. Moreover, the co-treatment with blends were able to modulate inflammatory response by altering the secretion of cytokines IL-1β, IL-6, IL-10, and TNF-α. Taken together, our results demonstrate for the first time the synergistic effects antioxidant and anti-inflammatory of Malpighia emarginata D.C and Camellia sinensis L. These results warrant further use of the blend powder for use in the products to heath beneficial, principally in terms of prevention of chronic diseases.