Background: Depression is a common psychiatric disorder that may be caused by dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis. The glucocorticoid receptor (GR) plays a significant role in regulating this axis. One negative regulator of GR action, previously associated with depressive behavior, is the overexpression of FK506-binding protein 5 (FKBP5), which may be regulated by microRNAs, including miR-511-5p. Objectives: In a rat model of depression, we aimed to investigate the expression of Fkbp5 and its regulator, miRNA-511-5p, during short- and long-term lithium treatment in four brain regions: the hypothalamus, hippocampus, pituitary, and frontal cortex. Methods: We used a rat model of depression induced by chronic mild stress (CMS) to assess if short- and long-term lithium treatment (7 and 42 days) influences Fkbp5 expression in the brain. We also assessed the effects of lithium treatment on the blood levels of corticosterone in CMS-exposed rats as compared to control groups. The changes in the expression of Fkbp5 were assessed by qPCR and Western blot. The expression of rno-miR-511-5p was assessed using qPCR. Statistical analysis was conducted in GraphPad Prism 9. Results: We found that long-term lithium treatment increased the expression of the FKBP5 protein in the pituitary gland in the lithium-treated rats compared to the control group. We also observed significant changes in Fkbp5 mRNA levels between CMS-exposed rats compared to the control animals, without significant changes in mRNA levels observed during short- and long-term lithium treatment in any brain region. We found no expression of rno-miR-511-5p in the analyzed brain regions. The corticosterone levels were significantly higher in CMS-exposed rats compared to the control, with no significant changes found between lithium-treated and control rats. Conclusions: FKBP5 protein expression in the brain may be regulated by long-term lithium treatment, thus affecting GR signaling in the rat depression model.

Asthma is a major non-communicable disease whose pathogenesis is still not fully elucidated. One of the asthma research models is precision-cut lung slices (PCLSs), and among the therapeutic options, miRNA molecules are of great interest. The aim of our study was to investigate whether inhibition of miR-223-3p and miR328a-3p affects the inflammatory response in PCLSs derived from a rat with HDM-induced allergic inflammation and a control rat. We generated rat PCLSs and transfected them with miR-223-3p and miR-328a-3p inhibitors. RNA was isolated from PCLSs and analyzed by qPCR. We also examined the proteins in the culture medium using the Magnetic Luminex Assay. The comparison between miRNA-transfected PCLSs and non-transfected controls showed significant differences in the expression of several genes associated with allergic inflammation, including Il-33, Ccl5, Prg2 and Tslp, in both the rat with allergic inflammation and the control rat. In the culture medium, we found no significant differences in protein levels between rat with allergic inflammation and the control. Our study highlighted some important issues: the need to extend the model by including more biological replicates, the need to standardize culture conditions, and the need to consider co-transfection with several miRNA inhibitors when modifying miRNAs expression in the PCLS model.

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.

Extracellular vesicles (EVs) and their miRNA cargo are important regulators of intercellular communication, but their role in connecting respiratory inflammation in asthma with systemic metabolic alterations remains unclear. We hypothesized that HDM-induced allergic inflammation alters selected serum EV-derived miRNAs and that these changes are associated with molecular alterations in lung and adipose tissue. Serum EV-miRNAs from control and HDM-induced allergic rats were isolated by size-exclusion chromatography and analyzed using TaqMan Advanced miRNA Assays. Candidate rno-let-7b-5p targets were integrated with lung and adipose tissue microarray data, validated by qPCR, and assessed in silico using IntaRNA and DMISO. Among the 13 analyzed miRNAs, rno-let-7b-5p showed a nominally significant 1.5-fold increase in serum EVs from allergic rats (unadjusted p = 0.03); no multiple-testing correction was applied. Ptafr and Vav3 were enriched in lung inflammatory pathways, whereas Zbtb16 was downregulated in adipose tissue. qPCR confirmed increased pulmonary Ptafr expression (p = 0.00802) and reduced adipose Zbtb16 expression (p = 0.00034). Computational analyses yielded high-confidence predictions of interactions between rno-let-7b-5p and both genes, which require experimental validation. These preliminary, hypothesis-generating findings suggest that serum EV-associated rno-let-7b-5p may be associated with molecular alterations in the lung and adipose tissue during HDM-induced allergic inflammation. Confirmation in larger independent cohorts is required.

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.