Role of Sex Hormones at Different Physiobiological Conditions and Therapeutic Potential in MBD2 Mediated Severe Asthma

Kiss1 receptor knockout exacerbates airway hyperresponsiveness and remodeling in a mouse model of allergic asthma

BACKGROUND

In asthma, sex-steroids signaling is recognized as a critical regulator of disease pathophysiology. However, the paradoxical role of sex-steroids, especially estrogen, suggests that an upstream mechanism or even independent of estrogen plays an important role in regulating asthma pathophysiology. In this context, in our previous studies, we explored kisspeptin (Kp) and its receptor Kiss1R's signaling in regulating human airway smooth muscle cell remodeling in vitro and airway hyperresponsiveness (AHR) in vivo in a mouse (wild-type, WT) model of asthma. In this study, we evaluated the effect of endogenous Kp in regulating AHR and remodeling using Kiss1R knockout (Kiss1R-/-) mice.

METHODS

C57BL/6J WT (Kiss1R+/+) and Kiss1R-/- mice, both male and female, were intranasally challenged with mixed-allergen (MA) and/or phosphate-buffered saline (PBS). We used flexiVent analysis to assess airway resistance (Rrs), elastance (Ers), and compliance (Crs). Following this, broncho-alveolar lavage (BAL) was performed for differential leukocyte count (DLC) and cytokine analysis. Histology staining was performed using hematoxylin and eosin (H&E) for morphological analysis and Masson's Trichrome (MT) for collagen deposition. Additionally, lung sections were processed for immunofluorescence (IF) of Ki-67, α-smooth muscle actin (α-SMA), and tenascin-c.

RESULTS

Interestingly, the loss of Kiss1R exacerbated lung function and airway contractility in mice challenged with MA, with more profound effects in Kiss1R-/- female mice. MA-challenged Kiss1R-/- mice showed a significant increase in immune cell infiltration and proinflammatory cytokine levels. Importantly, the loss of Kiss1R aggravated Th2/Th17 biased cytokines in MA-challenged mice. Furthermore, histology of lung sections from Kiss1R-/- mice showed increased collagen deposition on airway walls and mucin production in airway cells compared to Kiss1R+/+ mice. In addition, immunofluorescence analysis showed loss of Kiss1R significantly aggravated airway remodeling and subsequently AHR.

CONCLUSIONS

These findings demonstrate the importance of inherent Kiss1R signaling in regulating airway inflammation, AHR, and remodeling in the pathophysiology of asthma.

High ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 increases the risk of asthma attack in American asthma adults: a population study

OBJECTIVE

The relationship between vitamin D3 and asthma remains controversial. However, previous studies have largely overlooked the impact of epi-25-(OH)-vitamin D3. This study aims to investigate the effects of different forms of vitamin D3 on asthma attack in adults.

METHODS

In this cross-sectional study, a total of 3,873 eligible adult participants were extracted from the national health and nutrition examination survey (NHANES) database from 2007 to 2018. Based on quartiles method, different levels of vitamin D were divided into four groups (Quartile 1-4). Bivariate correlation analysis was performed for vitamin D and covariates to avoid multicollinearity. Multivariate logistic regression was used to investigate the association between serum levels of vitamin D3 (epi-25-(OH)-vitamin D3 and 25-(OH)-vitamin D3) and asthma attack, adjusting for covariates including age, gender, race, length of time in the U.S., house poverty income ratio (PIR), education level, smoking history, hypertension history, and diabetes history. The ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 was used for secondary analysis of its association with asthma attack. The outcomes were assessed by odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among the 3,873 eligible adults American with asthma, 1,508 (38.94%) had experienced at least one acute asthma attack in the past year. There was no significant correlation between vitamin D and covariates. After adjusting for covariates including age, gender, race, length of time in the U.S., house poverty income ratio (PIR), education level, smoking history, hypertension history and diabetes history, we found a positive correlation between the ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 and asthma attack. Additionally, a high ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 was more common among elder, male, of normal weight, non-Hispanic American, have a long time stay in the U.S., a high house PIR, and a history of hypertension individuals.

CONCLUSION

Our findings suggest that attention should be given to asthma attack associated with a high ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 in American adults who are elderly, male, of normal weight, non-Hispanic Americans, have long-term residence in the U.S., a high house PIR, and a history of hypertension.

RP105 Attenuates Ischemia/Reperfusion-Induced Oxidative Stress in the Myocardium via Activation of the Lyn/Syk/STAT3 Signaling Pathway

Although our previous studies have established the crucial role of RP105 in myocardial ischemia/reperfusion injury (MI/RI), its involvement in regulating oxidative stress induced by MI/RI remains unclear. To investigate this, we conducted experiments using a rat model of ischemia/reperfusion (I/R) injury. Adenovirus carrying RP105 was injected apically at multiple points, and after 72 h, the left anterior descending coronary artery was ligated for 30 min followed by 2 h of reperfusion. In vitro experiments were performed on H9C2 cells, which were transfected with recombinant adenoviral vectors for 48 h, subjected to 4 h of hypoxia, and then reoxygenated for 2 h. We measured oxidative stress markers, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, as well as malondialdehyde (MDA) concentration, using a microplate reader. The fluorescence intensity of reactive oxygen species (ROS) in myocardial tissue was measured using a DHE probe. We also investigated the upstream and downstream components of the signal transducer and activator of transcription 3 (STAT3). Upregulation of RP105 increased SOD and GSH-Px activities, reduced MDA concentration, and inhibited ROS production in response to I/R injury in vivo and hypoxia reoxygenation (H/R) stimulation in vitro. The overexpression of RP105 led to a decrease in the myocardial enzyme LDH in serum and cell culture supernatant, as well as a reduction in infarct size. Additionally, left ventricular fraction (LVEF) and fractional shortening (LVFS) were improved in the RP105 overexpression group compared to the control. Upregulation of RP105 promoted the expression of Lyn and Syk and further activated STAT phosphorylation, which was blocked by PP2 (a Lyn inhibitor). Our findings suggest that RP105 can inhibit MI/RI-induced oxidative stress by activating STAT3 via the Lyn/Syk signaling pathway.

Androgen Plays a Potential Novel Hormonal Therapeutic Role in Th17 Cells Predominant Neutrophilic Severe Asthma by Attenuating BECs Regulated Th17 Cells Differentiation via MBD2 Expression

T helper 17 (Th17) cells subtype of non-T2 asthma is less responsive (resistant) to inhaled corticosteroids (ICS), so also called severe asthma. Methyl-CpG-binding domain protein 2 (MBD2) regulates the differentiation of the Th17 cells, showing the possibility of a therapeutic target in severe asthma. Androgen tends to show beneficial therapeutic effects and is a “hot research topic,” but its role in the differentiation and expression of Th17 cells via MBD2 is still unknown. The aim of this study was to evaluate how sex hormone interacts with MBD2 and affects the differentiation and expression of Th17 cells in severe asthma. Here, first, we measured the concentration of androgen, estrogen, and androgen estrogen ratio from subjects and correlated it with severe asthma status. Then, we established an animal model and bronchial epithelial cells (BECs) model of severe asthma to evaluate the role of MBD2 in the differentiation and expression of Th17 cells (IL-17), the therapeutic potential of sex hormones in severe asthma, and the effect of sex hormones in BECs regulated Th17 cells differentiation via MBD2 at the cellular level. Increased MBD2 expression and Th17 cells differentiation were noted in the animal and the BECs severe asthma models. Th17 cell differentiation and expression were MBD2 dependent. Androgen attenuated the differentiation of BECs regulated Th17 cells via MBD2 showing BECs as a therapeutic target of androgen, and these findings postulate the novel role of androgen in Th17 cells predominant neutrophilic severe asthma therapy through targeting MBD2.