Persistent Inflammation and Nitric Oxide Dysregulation Are Transcriptomic Blueprints of Subglottic Stenosis

Subglottic stenosis (SGS) is a recurrent, obstructive, fibroinflammatory disease of the upper airway resulting in severe dyspnea, dysphonia, as well as other potentially fatal complications. Although aberrant inflammation and wound-healing are commonly associated with pathogenesis, the mechanism through which such processes occur and recur in affected patients remains poorly studied. Here we report that transcriptomic profiling of laryngotracheal regions from minimally-invasive mucosal swabs of SGS patients reveals a distinctively pro-inflammatory gene signature. Surprisingly, comparative genomics between SGS patients and mice with direct laryngotracheal injury suggest that SGS patients bear more resemblance to the acute than chronic phase of injury. Furthermore, functional and regulatory network analyses identify neutrophilic involvement through hyper-activation of NF-κB and its downstream inflammasome as a potential master regulator. Interestingly, nitric oxide synthesis was found to be downregulated in SGS patients compared to healthy controls. Thus, SGS represents a state of immunodeficiency whereby defective immune clearance triggers recurrent, long-lasting production of pro-inflammatory cytokines.

The biochemical estimation of the nitric oxide system in prenatally stressed rats

Introduction. Pregnancy development following unfavorable conditions could facilitate disorders of nitric oxide (NO) production during offspring’s postnatal life and «program» offspring’s cardiovascular diseases. Investigation of particular features and mechanisms of nitric oxide synthesis and action disorders following prenatal stress will promote expansion of considerations about pathogenesis of different cardiovascular diseases and propose new approaches to their prevention and management.The aim of the investigation is to assess the nature of nitric oxide synthesis and action in mature rats whose mothers were exposed to chronic «unpredictable» stress during pregnancy. Materials and methods. Pregnant rats were subdivided into the «control» and «stress» groups (in 20 animals). The rats from the «stress» group were exposed to multiple different stressors at various intervals, such as 1-day famine; 20-min. immobilization in the water at room temperature; 1-day contact with cats’ excrements. In the blood serum of 3-mo offspring (n=96, including «control» males – 24, «control» females – 26, «stress» males – 22, «stress» females – 24) concentration of the stable products of NO degradation – nitrates/nitrites (NO3–/NO2–), endothelial (eNOS) and inducible (iNOS) isoforms of the NO-synthase, inhibitor of NO-synthase asymmetric dimethylargininne (ADMA), cyclic guanosine monophosphate (cGMP), lipid peroxidation products – diene conjugates (DC) and malonic dialdehyde (MDA) and C-reactive protein (hsCRP) was detected. Results. The decrease of eNOS and cGMP concentration (by 12.9 and 31.9 %, respectively), increase of iNOS, hsCRP and ADMA concentration (by 49.9, 20.3 и 63.1 %, respectively) without statistically significant fluctuation in the NO3–/NO2– level and accumulation of DC and MDA by 21.1 % and 1.5 times in a prenatally stressed male rats’ blood serum were found (as compared with «control» male rats). In a blood serum of female rats, whose mothers were exposed to chronic «unpredictable» stress during pregnancy, a tendency to eNOS concentration decreasing, and increase of iNOS by 30.6 %, hsCRP by 23.9 % and MDA by 2.3 times without statistically significant changes in cGMP, ADMA, NO3–/NO2–, and DC concentration were detected (as compared with «control» female rats). Conclusion. Identified changes of the nitric oxide system synthesis and action in the prenatally stressed male rats could argue the high risk of their cardiovascular system lesion.

THE STATE OF THE NITRIC OXIDE SYNTHESIS SYSTEM IN THE COMORBID COURSE OF BRONCHIAL ASTHMA AND HYPERTENSION

Comorbidity is a common condition in medical practice. The presence of comorbid conditions in a patient makes a great contribution to the course and prognosis of the underlying disease, as well as the development of complications [12]. At the same time, diseases occurring with broncho-obstructive syndrome and arterial hypertension syndrome are widespread throughout the world [13, 14]. The aim of this study was to assess the degree of endothelial dysfunction associated with impaired nitric oxide synthesis, based on the state of the NO/NOS/ADMA system and genetic polymorphisms of the nitric oxide synthetase gene in patients with bronchial asthma combined with essential hypertension. Materials and methods Three groups of patients, 96 people each, were formed, corresponding in age and gender structure with a diagnosis of bronchial asthma (BA group), essential hypertension (EH group) and their joint course (BA+EH group). Serum concentrations of asymmetric dimethylarginine, symmetric dimethylarginine, genetic polymorphisms of nitric oxide synthase (synthases NOS3 786T/C and NOS3 894G/T) were determined. To determine the role of other factors in increasing the concentration of ADMA and SDMA, multiple linear regression analysis was performed. Results: according to the results of the study, for a group of patients with a combination of bronchial asthma and hypertension, there are increased levels of ADMA and SDMA, the T allele NOS3 786C/T is more common in hypertension, in multiple linear regression significant factors in increasing ADMA are the presence of hypertension, bronchial asthma, body mass index and glomerular filtration rate, for SDMA - the presence of hypertension, asthma and glomerular filtration rate. Conclusions: The comorbidity of bronchial asthma and arterial hypertension is associated with an increased serum concentration of ADMA and SDMA. The presence of the TT genotype of the NOS3 786C/T polymorphism is associated with an increased incidence of arterial hypertension in patients with asthma.

Can tissue nitric oxide synthesis 2 (iNOS) levels play a role in the pathophysiology of reflux esophagitis?

Objective: Nitric oxide (NO) is a strong dilatator, playing an important role in inflammatory events. Its production is regulated by NO synthase 2 (NOS2/iNOS). Our aim was to compare iNOS in esophageal tissues of patients with erosive or non-erosive reflux esophagitis to that of normal cases. Materials and Methods: The study was conducted in 2019–2020 on patients undergoing upper gastrointestinal (UGI) endoscopy. Study included 30 patients who had no reflux symptoms and were not diagnosed with reflux esophagitis in the UGI endoscopy (control), 22 who had pronounced reflux symptoms but could not be diagnosed with reflux esophagitis in the endoscopy (non-erosive reflux), and 51 who had reflux esophagitis in the endoscopy (erosive reflux esophagitis). Using the enzyme-linked immunosorbent assay, tissue iNOS levels were assessed on samples from the lower end of the esophagus. Results: Average iNOS level was 5.02±1.51 picogram/milliliter (pg/mL) in the normal group and 5.04±1.68 pg/mL in all reflux esophagitis cases. iNOS levels were higher in non-erosive reflux and lower in erosive reflux than in controls. In erosive reflux A, B, and C, iNOS levels were 5.03±1.64, 5.10±2.23, and 4.06±0.02 pg/mL, respectively. The level in erosive reflux C is considerably lower than in the normal group. However, none of the differences between the groups was significant. Conclusions: NO synthase was higher in patients with non-erosive reflux esophagitis and considerably lower in those with erosive reflux C, compared to the normal cases. Although not significant, the differences suggest that NO and iNOS levels may be important in reflux physiopathology.