Effects of small interfering RNA targeting TLR4 on expressions of adipocytokines in obstructive sleep apnea hyponea syndrome with hypertension in a rat model

Abstract

We explored the effects of RNA interference-mediated silencing of TLR4 gene on expressions of adipocytokines in obstructive sleep apnea hyponea syndrome (OSAS) with hypertension in a rat model. Systolic blood pressure of caudal artery and physiological changes were observed when establishing rat models of OSAS with hypertension. Mature rat adipocytes were induced from separated and cultured primary rat adipocytes. To transfect rat mature adipocytes, TLR4 siRNA group and negative control (NC) siRNA group were established. Expressions of TLR4 mRNA of adipocytes were examined after silenced by siRNA by quantitative real-time polymerase chain reaction (qRT-PCR). By enzyme-linked immunosorbent assay (ELISA), expressions of inflammatory cytokines, and adipocytokines of adipocytes were detected. Blood pressure in rat caudal artery was higher in the intermittent hypoxia group than that of the blank control group by 29.87 mmHg, and cardiocytes in the former group showed physiological changes, which indicated successful establishment of rat models of OSAS with hypertension. Red particles could be seen in mature rat adipocytes when stained with Oil Red O. Transfection of TLR4 mRNA was significantly suppressed in the TLR4 siRNA group, which didn't happen in the untransfected control group. Rats in the TLR4 siRNA group had significantly reduced expressions of such inflammatory cytokines as interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) and such adipocytokines as visfatin, adiponectin (ADN), and leptin than those in the untransfected control group. RNA interference-mediated silencing of TLR4 gene could regulate occurrence and development of OSAS with hypertension in rats by downregulating expressions of adipocytokines.

miR-21-5p Under-Expression in Patients with Obstructive Sleep Apnea Modulates Intermittent Hypoxia with Re-Oxygenation-Induced-Cell Apoptosis and Cytotoxicity by Targeting Pro-Inflammatory TNF-α-TLR4 Signaling

“…Toll-like receptor 4 (TLR4), a typical representative of pattern recognition receptors in innate immune responses, plays an important role in activation of inflammation in atherosclerosis. It has been recently demonstrated that IHR accelerated growth and vulnerability of atherosclerotic plaque, which probably acted by triggering the activation of TLR4/NF-κB signaling [4][5][6][7]. Acting as both up-stream and down-stream mediators of TLR signaling, tumor necrosis factor (TNF)-α has been shown to be upregulated in OSA patients, and this increase became more pronounced with the more severe grades of OSAS, indicating that TNF-α might be a promising circulating biomarker for the development of OSA [8].…”

“…To investigate the protective effect of miR-21-5p on overt inflammation and cell injury, we first evaluated whether miR-21-5p mimic had inhibitory effects on several predicted target genes in THP-1 cells under NOX condition. miR-21-5p mimic at different concentrations(1,5,10,25, and 50 nM, respectively) enhanced miR-21-5p gene expressions(Figure 3a, versus 0 nM, all p-values < 0.05) in a dose-dependent manner, while inhibited TNF-α (Figure 3b, versus 0 nM, all p-values < 0.05), IL-6R (Figure 3c, versus 0 nM, all p-values < 0.05), and TLR4 (Figure 3d, versus 0 nM, all p-values < 0.05) gene expressions in a dose-dependent manner.…”

Exosomes regulate SIRT3-related autophagy by delivering miR-421 to regulate macrophage polarization and participate in OSA-related NAFLD

“…In this study, chronic intermittent hypoxia (CIH) was used to construct an OSA model. The induction principle of OSA-related diseases, including metabolic dysfunction-associated steatotic liver disease, was based on OSA-induced chronic hypoxia [ 21 – 23 ]. OSA could decrease O 2 inhalation directly.…”

Advances in animal models of obstructive sleep apnea

“…During the modeling process, the cage was filled with nitrogen to reduce the oxygen concentration so that the animals were in an anoxic environment, and then the cage was filled with oxygen or air to simulate the resumption of ventilation of the animals. Similar to the occluding endotracheal intubation model under general anesthesia, this model could simulate different degree of AHI by setting the duration and cycle of hypoxia ventilation and simulate the duration of OSA patients by setting the duration of the experiment ( 5 – 28 ). A typical molding process is shown in Figure 1 .…”