Leptin-mediated ERK Signaling Pathway Promotes the Transformation of Rat Alveolar Type II Epithelial Cells Induced by Yunnan Tin Mine Dust / 中国肺癌杂志

BACKGROUND@#Currently, a significant number of miners are involved in mining operations at the Gejiu tin mine in Yunnan. This occupational setting is associated with exposure to dust particles, heavy metals, polycyclic aromatic hydrocarbons, and radioactive radon, thereby significantly elevating the risk of lung cancer. This study aims to investigate the involvement of leptin-mediated extracellular regulated protein kinase (ERK) signaling pathway in the malignant transformation of rat alveolar type II epithelial cells induced by Yunnan tin mine dust.@*METHODS@#Immortalized rat alveolar cells type II (RLE-6TN) cells were infected with Yunnan tin mine dust at a concentration of 200 μg/mL for nine consecutive generations to establish the infected cell model, which was named R₂₀₀ cells. The cells were cultured normally, named as R cells. The expression of leptin receptor in both cell groups was detected using the Western blot method. The optimal concentration of leptin and mitogen-activated protein kinase kinase (MEK) inhibitor (U0126) on R₂₀₀ cells was determined using the MTT method. Starting from the 20th generation, the cells in the R group were co-cultured with leptin, while the cells in the R₂₀₀ group were co-cultured with the MEK inhibitor U0126. The morphological alterations of the cells in each group were visualized utilizing hematoxylin-eosin staining. Additionally, concanavalin A (ConA) was utilized to detect any morphological differences, and an anchorage-independent growth assay was conducted to assess the malignant transformation of the cells. The changes in the ERK signaling pathway in epithelial cells after the action of leptin were detected using the Western blot method.@*RESULTS@#Both the cells in the R group and R₂₀₀ group express leptin receptor OB-R. Compared to the R₂₀₀ group, the concentration of leptin at 100 ng/mL shows the most significant pro-proliferation effect. The proliferation of R₂₀₀ cells infected with the virus is inhibited by 30 μmol/L U0126, and a statistically significant divergence was seen when compared to the control group (P<0.05). Starting from the 25th generation, the cell morphology of the leptin-induced R₂₀₀ group (R₂₀₀L group) underwent changes, leading to malignant transformation observed at the 30th generation. The characteristics of malignant transformation became evident by the 40th generation in the R₂₀₀L group. In contrast, the other groups showed agglutination of P40 cells, and the speed of cell aggregation increased with an increase in ConA concentration. Notably, the R₂₀₀L group exhibited faster cell aggregation compared to the U0126-induced R₂₀₀ (R₂₀₀LU) group. Additionally, the cells in the R₂₀₀L group were capable of forming clones starting from P30, with a colony formation rate of 2.25‰±0.5‰. However, no clonal colonies were observed in the R₂₀₀LU group and R₂₀₀ group. The expression of phosphorylated extracellular signal-regulated kinase (pERK) was enhanced in cells of the R₂₀₀L group. However, when the cells in the R₂₀₀L group were treated with U0126, a blocking agent, the phosphorylation level of pERK decreased.@*CONCLUSIONS@#Leptin can promote the malignant transformation of lung epithelial cells infected by mine dust, and the ERK signaling pathway may be necessary for the transformation of alveolar type II epithelial cells induced by Yunnan tin mine dust.

Nanomedicine for acute respiratory distress syndrome: The latest application, targeting strategy, and rational design

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air-blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.

Effect of NRP1 gene knockout on process of radiationinduced pulmonary fibrosis and its mechanism / 吉林大学学报(医学版)

Objective: To observe the effect of neuroopilin-1 (NRP1) gene on the process of radiation-induced pulmonary fibrosis (RIPF), and to explore its roles in the occurrence and development of epithelial-mesenchymal transition (EMT) mediated by Wnt/fi-catenin pathway tail identification was performed in and TGF-β1/Smads pathway, and extracellular matrix (ECM) deposition. Methods: The Cre-LoxP recombinase system was used to construct the transgenic C57BL/6J mice with NRP1 gene specific knockout in alveolar type II epithelial cells (AT-II) and the mice. A total of 160 mice were randomly divided into 4-week group, 8-week group, 16-week group and 24-week group. In each group, the mice were randomly divided into wild type (Con) group, wild type+irradiation (IR) group, NRP1 gene-specific knockout (KO-Con) group, NRP1 gene-specific knockout+irradiation (KO+IR) group according to the method of random number table; there were 10 mice per group. In KO-Con and KO + IR groups, the NRP1 gene was specifically knocked out in the AT-II cells by intraperitoneal injection of tamoxifen, and the mouse models of RTPF were established by 20 Gy total thoracic irradiation in IR group and KO+IR group. After the models were constructed, HE staining and Masson staining were used to verify whether the models were successfully constructed. Immunohistochemistry (IHC) method was used to detect the type I collagen (Col I) and crsmooth muscle actin α-SMA) protein expression levels; Western blotting method was performed to detect the NRP1, β-catenin, TGF-β1, and Smad2 protein expression levels in the lung tissue of the mice; Quantitative fluorensence real-time polymerase chain reaction (qRT-PCR) method was used to detect the expression levels of NRP1, Col I, α-SMA, β-catenin, TGF-βl, Smad2, E-cadherin, N-cadherin, and Vimentin mRNA in the lung tissue of the mice. Results: The results of HE and Masson staining showed the RTPF models were successfully established, and the lung tissue of the mice in IR group mainly showed the pathomorphology of radiation pneumonitis. Compared with Con group, the protein and mRNA expression levels of NRP1 in the lung tissue of the mice in IR group were gradually increased with the prolongation of time (P<0.05), and reached the highest at 24 weeks (P<0.01). Compared with Con group, the expression levels of Col I, α-SMA, β-catenin, TGF-β1, and Smad2 proteins and mRNA in the lung tissue of the mice in IR group and KO+IR group were increased gradually with the prolongation of time (P<0.05 or P<0.01). Compared with IR group, the expression levels of Col I, α-SMA, β-catenin, TGF-β1, and Smad2 protein and mRNA in the lung tissue of the mice in KO+IR group were significantly decreased (P<0.05 or P<0.01), but they were higher than those in Con group (P<0.05 or P<0.01). Compared with Con group, the expression levels of the epithelial cell marker E-Cadherin mRNA in the lung tissue of the mice in IR group and KO+IR group were gradually decreased with the prolongation of time (P< 0.01), and the expression levels of the interstitial cell markers N-Cadherin and Vimentin were increased (P<0.05 or P<0.01), but the expression levels of E-cadhern mRNA in the lung tissue of the mice in KO-IR group were significantly higher than those in IR group (P<0.05 or P<0.01), and the expression levels of N-Cadherin and Vimentin mRNA in the lung tissue of the mice in KO + IR group at each time point were lower than those in IR group (P<0.05 or P<0.01). Conclusion: Knockout of NRP1 gene can inhibit the occurrence and development of RTPF, and its mechanism may be involved in regulating the expressions of Wnt/fi-catenin and TGF-β1/Smads signaling pathways in the lung tissue and inhibiting the EMT process in the mice.

siRNA knocks down Bax gene and inhibits TNF-α induced apoptosis in A549 cells / 中国病理生理杂志

AIM: To investigate the influence of tumor necrosis factor-α (TNF-α) induced apoptosis through knocking down Bax gene by RNA interference (RNAi) in human alveolar type II epithelial cells (A549). METHODS: A549 cells were cultured in vitro and divided into 4 groups according to RNAi treatment: control group, TNF-α treated group, Bax siRNA group and control siRNA group. Chemically synthesized small interfering RNA (siRNA) directed against human Bax gene was transfected into A549 cells by cationic liposome. The effect of RNAi was investigated by reverse transcription PCR, Western blotting and immunohistochemisty, and the rate of apoptosis was investigated by flow cytometry. RESULTS: Bax gene was knocked down effectively in Bax siRNA group (P<0.05). Apoptosis was induced by TNF-α in TNF-α treated group and control siRNA group. However, it was abolished in Bax siRNA group by the downregulation of Bax gene compared to TNF-α treated group and control siRNA group (P<0.05). CONCLUSION: This result suggests that Bax gene has a significant role of pro-apoptosis in A549 cells and knocking down Bax gene by RNAi can effectively inhibit TNF-α-induced apoptosis in A549 cells.

siRNA knocks down Bax gene and inhibits TNF-? induced apoptosis in A549 cells / 中国病理生理杂志

AIM:To investigate the influence of tumor necrosis factor-? (TNF-?) induced apoptosis through knocking down Bax gene by RNA interference (RNAi) in human alveolar type II epithelial cells (A549). METHODS: A549 cells were cultured in vitro and divided into 4 groups according to RNAi treatment: control group,TNF-? treated group,Bax siRNA group and control siRNA group. Chemically synthesized small interfering RNA (siRNA) directed against human Bax gene was transfected into A549 cells by cationic liposome. The effect of RNAi was investigated by reverse transcription PCR,Western blotting and immunohistochemisty,and the rate of apoptosis was investigated by flow cytometry. RESULTS: Bax gene was knocked down effectively in Bax siRNA group (P