Severe Neutrophilic Asthma: Pathogenesis and Treatment

Asthma is a common chronic airway disease affecting about 358 million people worldwide, and an estimated 7 million children globally. Approximately 10% of patients with asthma have severe refractory disease, which is difficult to control on high doses of inhaled corticosteroids and other modifiers. Among these, are patients with severe neutrophilic asthma. Neutrophilic asthma is a severe phenotype of asthma, characterized by frequent exacerbations, persistent airway obstruction, and poor lung function. Immunopathologically, it is characterized by the presence of high levels of neutrophils in the airways and lungs. Interleukin-17 produced by Th17 cells, plays a key role in the pathogenesis of neutrophilic asthma by expressing the secretion of chemoattractant cytokines and chemokines for the recruitment, and activation of neutrophils. Interleukin-8 is a powerful chemoattractant and activator of neutrophils. Activated neutrophils produce an oxidative burst, releasing multiple reactive oxygen species, proteinases, cytokines, which cause airway epithelial cell injury, inflammation, airway hyperresponsiveness, and remodeling. Furthermore, exasperated neutrophils due to viral, bacterial or fungal infections, and chemical irritants can release extracellular nucleic acids (DNA), designated as NETs (neutrophil extracellular traps), which are more toxic to the airway epithelial cells, and orchestrate airway inflammation, and release alarmin cytokines. Dysregulated NETs formation is associated with severe asthma. Most patients with neutrophilic asthma are unresponsive to the standard of care, including high dose inhaled corticosteroids, and to targeted biologics, such as mepolizumab, and dupilumab, which are very effective in treating eosinophilic asthma. There is unmet need to explore for novel biologics for the treatment of neutrophilic asthma, and in refining therapies, such as bronchial thermoplasty.

Anshen Buxin Liuwei Pill, a Mongolian Medicinal Formula, Could Protect H2O2-Induced H9c2 Myocardial Cell Injury by Suppressing Apoptosis, Calcium Channel Activation, and Oxidative Stress

Background. Anshen Buxin Liuwei pill (ABLP) is a Mongolian medicinal formula which has a therapeutic effect on the symptoms such as coronary heart disease, angina pectoris, arrhythmia, depression and irritability, palpitation, and short breath. However, its bioactivity against cardiac injury remains unclear. Methods. The protective effect of ABLP was evaluated using H9c2 cells. Cell viability, intracellular Ca2+, reactive oxidative indices, and mitochondrial membrane potential (∆ψ) were assessed, respectively. The mRNA levels of Ca2+ channel-related genes (DHPR, RyR2, and SCN5A) and oxidative stress-related genes (Keap1, Nrf2, and HO-1) were measured by RT-PCR. Results. 0.5–50 μg/mL ABLP could significantly decrease H2O2-induced cell injury by suppressing cell necrosis/apoptosis and excess oxidative stress, ameliorating the collapse of ∆ψ, and reducing intracellular Ca2+ concentration. Furthermore, 0.5–50 μg/mL ABLP reversed H2O2-induced imbalance in the mRNA levels of DHPR, RyR2, SCN5A, Keap1, Nrf2, and HO-1 gene in H9c2 cells, which further illustrate the mechanism. Conclusion. ABLP provided protective and therapeutic benefits against H2O2-induced H9c2 cell injury, indicating that this formula can effectively treat coronary disease. In addition, the present study also provides an in-depth understanding of the pharmacological functions of ABLP, which may lead to further successful applications of Mongolian medicine.

Design, Synthesis of Amide Derivatives of Scutellarin And Their Anti-Leukemia And Neuroprotective Activities

A unique series of amide-scutellarin derivatives were designed and synthesized in order to develop the function of scutellarin further. The antiproliferative activity of all target compounds against two human leukaemia cell lines were evaluated. Among them, compounds 6g and 7c displayed the most antitumor activities against HL-60 and THP-1. Moreover, all compounds were also assayed for their neuroprotective activity against hydrogen peroxide (H2O2)-induced PC-12 cell injury, and the majority of the compounds had moderate to good neuroprotective properties. These findings confirmed that these target compounds could be used as anti-leukaemia and neuroprotective candicates in the future.

Activation of Transcription Factor EB Alleviates Tubular Epithelial Cell Injury via Restoring Lysosomal Homeostasis in Diabetic Nephropathy

Disruption of lysosomal homeostasis contributes to the tubulopathy of diabetic nephropathy; however, its underlying mechanisms remain unclear. Herein, we report that decreased activity of transcription factor EB (TFEB) is responsible for the disturbed lysosome biogenesis and clearance in this pathological process. This was confirmed by the findings that insufficient lysosomal replenishment and damaged lysosomal clearance coincided with TFEB inactivation, which was mediated by mTOR hyperactivation in the renal tubular epithelial cells (TECs) of diabetic nephropathy. Furthermore, either TFEB overexpression or pharmacological activation of TFEB enhanced lysosomal clearance via promoting lysosomal biogenesis and protected TECs by reducing apoptosis in vitro. In addition, pharmacological activation of TFEB attenuated renal tubule injury, apoptosis, and inflammation in db/db mice. In conclusion, diabetes-induced mTOR activation represses TFEB function, thereby perturbing lysosomal homeostasis through impairing lysosomal biogenesis and clearance in TECs. Moreover, TFEB activation protects TECs from diabetic injuries via restoring lysosomal homeostasis.

Zeaxanthin Attenuates the Vicious Circle Between Endoplasmic Reticulum Stress and Tau Phosphorylation: Involvement of GSK-3β Activation

Background: Alzheimer’s disease (AD) characterized by neurofibrillary tangles caused by hyperphosphorylated tau is the most common cause of dementia. Zeaxanthin (Zea), derived from fruits and vegetables, may reduce the risk of AD. Endoplasmic reticulum stress (ERS) might cause memory impairment in AD. Objective: Here, we studied protective role of Zea on the relationship among ERS, activity of glycogen synthase kinase 3β (GSK-3β, tau phosphorylated kinase), and p-Tau (Ser 396 and Thr 231). Methods: The results were obtained in non-RA and RA group by using different treatment, such as 9-cis-retinoic acid (RA), TM (ERS inducer), Zea, 4-PBA (ERS inhibitor), and SB216763 (GSK-3β inhibitor). The methods included flow cytometry and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] for the detections of cell cycle and cell viability and western blot as a third measure of proteins in relation to ERS and tau phosphorylation. We have collected and analyzed all the data that suggested application of drugs for the treatment in non-RA and RA group. Results: Zea displays its protection on TM-induced cell injury, upregulation of GRP78 expression, and change of GSK-3β activity and tau phosphorylation when 4-PBA and SB216763 interfere with the process. Conclusion: These studies indicated that Zea is in vicious circle in ERS, GSK-3β, and tau phosphorylation, and further reflect its potential value in AD.

Study on the Mechanism of Efficient Extracellular Expression of Toxic Streptomyces Phospholipase D in Brevibacillus Choshinensis Under Mg2+ Stress

BackgroundPhospholipase D (PLD) has significant advantages in the food and medicine industries due to its unique transphosphatidylation. However, the high heterologous expression of PLD is limited by its cytotoxicity. The present study sought to express the strong extracellular protein of PLD in the non-pathogenic Brevibacillus choshinensis (B. choshinensis).ResultsThe extracellular PLD was effectively expressed by the strong promoter (P2) under Mg2+ stress, with the highest activity of 1.0×104 U·L-1. The inductively coupled plasma–mass spectrometry (ICP-MS) results elucidated that the fast expression of PLD by P2 promoter without Mg2+ stress induced the ionic homeostasis perturbation caused by the highly enhanced Ca2+ influx, leading to cell injury or death. Under Mg2+ stress, Ca2+ influx was significantly inhibited, and the strengths of P2 promoter and HWP gene expression were weakened. The study results revealed that the mechanism of Mg2+ induced cell growth protection and PLD expression might be related to the lowered strength of PLD expression by P2 promoter repression to meet with the secretion efficiency of B. choshinensis, and the redistribution of intracellular ions accompanied by decreased Ca2+ influx.ConclusionsThe PLD production was highly improved under Mg2+ stress. By ICP-MS and qPCR analysis combined with other results, the mechanism of the efficient extracellular PLD expression under Mg2+ stress was demonstrated. The relatively low-speed PLD expression during cell growth alleviated cell growth inhibition and profoundly improved PLD production. These results provided a potential approach for the large-scale production of extracellular PLD and novel insights into PLD function.

Circulating cell-free mitochondrial DNA in pregnancy

Circulating cell-free mitochondrial DNA (ccf-mtDNA) released upon cell injury or death stimulates diverse pattern recognition receptors to activate innate immune responses and initiate systemic inflammation. In this review, we discuss the temporal changes of ccf-mtDNA during pregnancy and its potential contribution to adverse pregnancy outcomes in pregnancy complications.