Wojciech Langwiński

Endoplasmatic reticulum (ER) stress is an imbalance between the load of unfolded proteins and the ability of cellular mechanisms to handle it. Under the influence of this stress, cells activate the unfolded protein response (UPR). The molecular mechanisms of ER stress have been repeatedly linked to metabolic and inflammatory diseases, such as obesity and allergic inflammation. The aim of our study was to investigate if the allergic inflammation in adipocytes affects the expression of UPR pathway genes and Ormdl3 and whether miRNA-665 can modify inflammatory response in adipocytes. We isolated rat preadipocytes and treated them with IL-13 to induce allergic inflammation. Later, we transfected them with miRNA-665 inhibitor. RNA was isolated from adipocytes and analyzed by qPCR. From cell culture medium, we performed an LDH assay and ELISA for secreted IL-6 and TNFα proteins. A comparison between control cells and IL-13-treated cells showed significant differences in the expression of most of the studied UPR pathway genes, Ormdl3 and Bax. Comparing the IL-13-treated cells after miR-665 transfection with non-transfected ones, we observe significant differences only in Ire1α gene. Our research suggests that allergic inflammation induces an adaptive UPR in adipocytes and miR-665 may selectively modify this response, triggering the IRE1/XBP1 axis.

Asthma is a chronic respiratory disease affecting over 262 million people worldwide, with obesity-associated asthma emerging as a distinct endotype of increasing prevalence characterized by metabolic inflammation and airway remodeling. Unlike allergic asthma, this phenotype is driven by chronic low-grade inflammation, originating from hypertrophic and hypoxic adipose tissue. This dysregulated state leads to the activation of pro-inflammatory pathways and the secretion of cytokines, contributing to airway dysfunction and remodeling. Recent evidence highlights non-coding RNAs (ncRNAs) as key regulators of these processes. MicroRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) influence inflammation and remodeling by modulating immune cell polarization, cytokine secretion, extracellular matrix composition, and airway smooth muscle cell (ASMC) proliferation. Notably, H19, MEG3, GAS5, miR-26a-1-3p, and miR-376a-3p have been implicated in both asthma and obesity, suggesting their role in linking metabolic dysfunction with airway pathology. Moreover, ncRNAs regulate Treg/Th17 balance, fibroblast activation, and autophagy-related pathways, further influencing airway remodeling. Our in silico analysis highlighted the IGF1R signaling pathway as a key enriched mechanism, linking selected ncRNAs with metabolic dysregulation and inflammation in obesity-related asthma. This paper reviews how ncRNAs regulate inflammation and airway remodeling in obesity-associated asthma, emphasizing their potential molecular links between metabolic dysfunction and airway pathology.

Precision-cut lung slices (PCLS) are ex vivo models with preserved lung cell populations and maintained tissue architecture. PCLS are, therefore, a powerful tool in respiratory research to study molecular mechanisms that closely reflect whole tissue biology. High-quality RNA and protein extraction from PCLS is, however, challenging as agarose significantly interferes with the yield and purity of extracted material. The present study aimed to optimize QIAzol-based isolation protocol for high-yield and quality RNA, miRNA, and protein extraction from PCLS. PCLS were prepared from 10 to 15-week-old Wistar rats and cultured for 7 days in Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12 (DMEM/F-12) supplemented with 0.1% FBS, penicillin, and streptomycin. LDH release to PCLS culture media was measured to determine cellular cytotoxicity. To select the optimal miRNA/RNA isolation protocol, we tested two different times (10 min, 2 h) and temperatures (room temperature, 4 °C, and −20 °C) of precipitation with isopropanol. Finally, we also assessed isolation with GHCL (guanidinium hydrochloride) extraction buffer. To select the optimal protein isolation protocol, we tested protein precipitation for 10 min at room temperatures (21 ± 1 °C) with 1.5 volumes of isopropanol and 3 volumes of acetone per 1 volume of phenol-ethanol supernatant. Additionally, we also tested protein precipitation for 3 h at −20 °C with 3, 5, and 7 acetone volumes per 1 volume of phenol-ethanol supernatant. We also validated protein precipitation with back extraction buffer instead of 100% ethanol. To measure the general efficiency of the optimized QIAZ-4 protocol, we used native rat lungs. PCLS for the ex vivo model of allergic inflammation were treated with IL-13 at a concentration of 80 ng/ml. Standard QIAzol isolation protocol provided RNA, miRNA, and protein with low yield and poor quality. We found that 2-h isopropanol precipitation at 4 °C with a high concentration of salts significantly increased the yield and quality of extracted RNA and miRNA and provided acceptable qPCR efficiency (between 90 and 110%). Surprisingly, 2-h isopropanol precipitation at −20 °C significantly increased qPCR efficiency above the acceptable range (average efficiency: 120.4%). As for protein extraction, we found that 3-h acetone precipitation at −20 °C provided the highest yield with linear protein detection on Westen Blot. Optimized QIAZ-4 provided significantly higher miRNA and RNA yield compared to standard QIAzol protocols. We also found a significantly increased expression of Eotaxin-1 in PCLS treated with IL-13 as compared to the untreated controls. In our study, we described a simple QIAzol-based method for the simultaneous isolation of RNA, miRNA, and protein from PCLS.