Dexmedetomidine alleviates LPS‑induced acute lung injury via regulation of the p38/HO‑1 pathway

Differentially Expressed Genes in Clear Cell Renal Cell Carcinoma as a Potential Marker for Prognostic and Immune Signatures

Clear cell renal cell carcinoma (ccRCC) is characterized by the inactivation of the von Hippel–Lindau (VHL) gene. Of note, no other gene is mutated as frequently as VHL in ccRCC, turning out that patients with inactivated VHL constitute the majority of ccRCC-related character. Thus, differentially expressed genes (DEGs) and their molecular networks caused by VHL mutation were considered as important factors for influencing the prognosis of ccRCC. Here, we first screened out six DEGs (GSTA1, GSTA2, NAT8, FABP7, SLC17A3, and SLC17A4) which downregulated in ccRCC patients with VHL non-mutation than with the mutation. Generally, most DEGs with high expression were associated with a favorable prognosis and low-risk score. Meanwhile, we spotted transcription factors and their kinases as hubs of DEGs. Finally, we clustered ccRCC patients into three subgroups according to the expression of hub proteins, and analyzed these subgroups with clinical profile, outcome, immune infiltration, and potential Immune checkpoint blockade (ICB) response. Herein, DEGs might be a promising biomarker panel for immunotherapy and prognosis in ccRCC. Moreover, the ccRCC subtype associated with high expression of hubs fit better for ICB therapy.

Effects of dexmedetomidine on the expression profile of tsRNAs in LPS-induced acute lung injury

BACKGROUND

Acute lung injury (ALI) is characterized by impaired alveolar function and excessive inflammation, which is commonly seen in clinical anesthesia and intensive care units. tRNA-derived small RNA (tsRNA) is a non-coding RNA that can be used as a potential disease diagnostic biomarker. The connection between ALI and tsRNA remains unknown. We aimed to explore the possible regulatory functions and mechanisms of tsRNAs in ALI treated with DEX.

METHODS

Firstly, we established the ALI model by LPS injection and explored the effect of dexmedetomidine (DEX) treatment on lung damage. Then, the lung tissues were obtained from the LPS and LPS + DEX group for small RNA sequencing.

RESULTS

We proved that DEX could ameliorate pulmonary injury, and decreased inflammation, pulmonary edema, and ferroptosis (MDA down-regulation and GPX4 up-regulation) in ALI. Furthermore, in the tsRNA expression profile, the top 10 down-regulated tsRNAs were tsRNA-1018, tsRNA-3045b, tsRNA-5021a, tsRNA-1020, tsRNA-5002b, tsRNA-3045b, tsRNA-1026, tsRNA-5004a, tsRNA-5005b and tsRNA-1009, and the top 10 up-regulated tsRNAs were tsRNA-3025b, tsRNA-3025a, tsRNA-5016b, tsRNA-3042b, tsRNA-3029b, tsRNA-3028b, tsRNA-5006a, tsRNA-3027b, tsRNA-3027a, and tsRNA-5009b. The enrichment analysis of GO terms and KEGG pathways pointed that target genes of DE-tsRNAs were mainly enriched in regulation of transcription-associated GO terms, NF-kappa B signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway. The RT-qPCR results of tsRNA-1020 and tsRNA-1018 were in accordance with small RNA sequencing data.

CONCLUSION

DEX affected the abnormal expression of tsRNAs in ALI. These aberrantly expressed tsRNAs and enriched physiological processes provide a scientific basis for the diagnosis and treatment of ALI.

VHL regulates the sensitivity of clear cell renal cell carcinoma to SIRT4-mediated metabolic stress via HIF-1α/HO-1 pathway

Clear cell renal cell carcinomas (ccRCC) reprogram carbon metabolism responses to hypoxia, thereby promoting utilization of glutamine. Recently, sirtuin 4 (SIRT4), a novel molecular has turned out to be related to alternating glutamine metabolism and modulating the tumor microenvironment. However, the role of SIRT4 in ccRCC remains poorly understood. Here, we illustrated that the expression of SIRT4 is markedly reduced in cancerous tissues, and closely associated with malignancy stage, grade, and prognosis. In ccRCC cells, SIRT4 exerted its proapoptotic activity through enhancing intracellular reactive oxygen species (ROS). Heme oxygenase-1 (HO-1) is part of an endogenous defense system against oxidative stress. Nevertheless, overexpression of SIRT4 hindered the upregulation of HO-1 in von Hippel-Lindau (VHL)-proficient cells and repressed its expression in VHL-deficient cells. This discrepancy indicated that competent VHL withstands the inhibitory role of SIRT4 on HIF-1α/HO-1. Functionally, overexpression of HO-1 counteracted the promotional effects of SIRT4 on ROS accumulation and apoptosis. Mechanistically, SIRT4 modulates ROS and HO-1 expression via accommodating p38-MAPK phosphorylation. By contrast, downregulation of p38-MAPK by SB203580 decreased intracellular ROS level and enhanced the expression of HO-1. Collectively, this work revealed a potential role for SIRT4 in the stimulation of ROS and the modulation of apoptosis. SIRT4/HO-1 may act as a potential therapeutic target, especially in VHL-deficient ccRCCs.

L-carnitine alleviated acute lung injuries induced by potassium dichromate in rats: involvement of Nrf2/HO-1 signaling pathway

The activation of the Nrf2/HO-1 signaling pathway regulates cellular antioxidant stress and exerts anti-inflammatory and cytoprotective effects against acute lung injury (ALI). The present study aimed to evaluate the therapeutic role of L-carnitine (LC) against potassium dichromate (PD) - induced acute lung injury in adult male albino rats via modulation of Nrf2/HO-1 signaling pathway. For this purpose, forty rats were randomly allocated into 5 groups (8 rats each). The normal group received intranasal (i.n.) saline, while the ALI group received intranasal instillation of PD as a single dose of 2 mg/kg. The 3d - 5th groups received PD then after 24 h administered L-carnitine (25, 50 and 100 mg/kg; orally) for 3 consecutive days. The therapeutic effect of L-carnitine was evaluated by assessment of serum levels of glutathione (GSH) and malondialdehyde (MDA) along with measurement of lung contents of transforming growth factor β1 (TGFβ1), protein kinase B (AKT), Nuclear factor erythroid-2 related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 enzyme (NQO1) and glutathione cysteine ligase modifier subunit (GCLM) expression. Post-treatment with L-carnitine effectively increased the levels of GSH and AKT, elevated Nrf2 and its target genes and decreased the levels of MDA and TGFβ1 in comparison with PD control rats. Additionally, L-carnitine effectively reduced the number of goblet cell, inhibited the mucus formation in bronchioles and interstitial inflammatory infiltrate as well as alleviated the destruction of alveolar walls, and the congestion of blood vessels in lung tissue induced by PD. Our findings showed that L-carnitine may be a promising therapeutic agent against PD-induced acute lung injury.

Dexmedetomidine ameliorates lipopolysaccharide-induced acute lung injury by inhibiting the PI3K/Akt/FoxO1 signaling pathway

Purpose

Dexmedetomidine (DEX) has been associated with inflammation, oxidative stress, and apoptosis, but its effects on lipopolysaccharide (LPS)-induced lung injury remain uncertain. The present study explored the effects of DEX on LPS-induced lung injury and studied the possible molecular mechanisms by testing the effects of the phosphoinositide-3 kinase (PI3K) inhibitor LY294002 and BEZ235.

Methods

Seventy C57BL/6 mice were randomly divided into the control, LPS, LPS + DEX, LPS + LY294002, LPS + BEZ235, LPS + DEX + LY294002, and LPS + DEX + BEZ235groups. Lung samples were collected 48 h after LPS treatment.

Results

DEX significantly inhibited LPS-induced increases in the lung weight/body weight ratio and lung wet/dry weight ratio, decreased inflammatory cell infiltration, and decreased the production of proinflammatory factors, such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α)in the lungs. DEX also markedly attenuated the increases in malondialdehyde 5 (MDA 5) and inositol-dependent enzyme a (IRE-a), attenuated the decrease in superoxide dismutase 1(SOD-1), reversed the low expression of B-cell lymphoma-2 (Bcl-2), and the high expressions of Bax and Caspase-3. DEX also decreased the expression of phosphorylated PI3K and phosphorylated Akt and increased the expression of phosphorylated forkhead box-O transcription factor 1 (FoxO1). More interestingly, LY294002 or BEZ235 pretreatment significantly abolished the inhibitory effects of DEX on LPS-induced lung inflammation, oxidative stress, and apoptosis.

Conclusions

These data suggest that DEX ameliorates LPS-induced acute lung injury partly through the PI3K/Akt/FoxO1 signaling pathway.