The role and mechanism of PDZ binding kinase in hypobaric and hypoxic acute lung injury.

Background: Acute lung injury (ALI) caused by hypobaric hypoxia (HH) is frequently observed in high-altitude areas, and it is one of the leading causes of death in high-altitude-related diseases due to its rapid onset and progression. However, the pathogenesis of HH-related ALI (HHALI) remains unclear, and effective treatment approaches are currently lacking. Methods: A new mouse model of HHALI developed by our laboratory was used as the study subject (Chinese patent No. ZL 2021 1 1517241 X). Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the messenger RNA (mRNA) expression levels of PDZ-binding kinase (PBK), sirtuin 1 (SIRT1), and PTEN-induced kinase 1 (PINK1) in mouse lung tissue. Hematoxylin and eosin staining was used to observe the main types of damage and damaged cells in lung tissue, and the lung injury score was used for quantification. The wet-dry (W/D) ratio was used to measure lung water content. Enzyme-linked immunosorbent assay was used to detect changes in inflammatory factors and oxidative stress markers in the lungs. Western blotting verified the expression of various mitochondrial autophagy-related proteins. The 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimi-dazoylcarbocyanine iodide (JC-1) method was used determined the health status of mitochondria based on changes in mitochondrial membrane potential. Transmission electron microscopy was used to directly observe the morphology of mitochondria. Multicolor immunofluorescence was used to observe the levels of mitochondrial autophagy markers. Other signaling pathways and molecular mechanisms that may play a role in epithelial cells were analyzed via through RNA sequencing. Results: Low pressure and hypoxia caused pathological changes in mouse lung tissue, mainly ALI, leading to increased levels of inflammatory factors and intensified oxidative stress response in the lungs. Overexpression of PBK was found to alleviate HHALI, and activation of the p53 protein was shown to abrogate this therapeutic effect, while activation of SIRT1 protein reactivated this therapeutic effect. The therapeutic effect of PBK on HHALI is achieved via the activation of mitochondrial autophagy. Finally, RNA sequencing demonstrated that besides mitochondrial autophagy, PBK also exerts other functions in HHALI. Conclusions: Overexpression of PBK inhibits the expression of p53 and activates SIRT1-PINK1 axis mediated mitochondrial autophagy to alleviate HHALI.

CYP2J2 and EETs protect against pulmonary arterial hypertension with lung ischemia-reperfusion injury in vivo and in vitro.

BACKGROUND: Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs), which exert anti-inflammatory, anti-apoptotic, pro-proliferative, and antioxidant effects on the cardiovascular system. However, the role of CYP2J2 and EETs in pulmonary arterial hypertension (PAH) with lung ischemia-reperfusion injury (LIRI) remains unclear. In the present study, we investigated the effects of CYP2J2 overexpression and exogenous EETs on PAH with LIRI in vitro and in vivo. METHODS: CYP2J2 gene was transfected into rat lung tissue by recombinant adeno-associated virus (rAAV) to increase the levels of EETs in serum and lung tissue. A rat model of PAH with LIRI was constructed by intraperitoneal injection of monocrotaline (50 mg/kg) for 4 weeks, followed by clamping of the left pulmonary hilum for 1 h and reperfusion for 2 h. In addition, we established a cellular model of human pulmonary artery endothelial cells (HPAECs) with TNF-α combined with anoxia/reoxygenation (anoxia for 8 h and reoxygenation for 16 h) to determine the effect and mechanism of exogenous EETs. RESULTS: CYP2J2 overexpression significantly reduced the inflammatory response, oxidative stress and apoptosis associated with lung injury in PAH with LIRI. In addition, exogenous EETs suppressed inflammatory response and reduced intracellular reactive oxygen species (ROS) production and inhibited apoptosis in a tumor necrosis factor alpha (TNF-α) combined hypoxia-reoxygenation model of HPAECs. Our further studies revealed that the anti-inflammatory effects of CYP2J2 overexpression and EETs might be mediated by the activation of PPARγ; the anti-apoptotic effects might be mediated by the PI3K/AKT pathway. CONCLUSIONS: CYP2J2 overexpression and EETs protect against PAH with LIRI via anti-inflammation, anti-oxidative stress and anti-apoptosis, suggesting that increased levels of EETs may be a promising strategy for the prevention and treatment of PAH with LIRI.

circUBAP2 exacerbates malignant capabilities of NSCLC by targeting KLF4 through miR-3182 modulation.

Chemo-resistance and refractoriness remain challenges for Non-small cell lung cancer (NSCLC) patients and the underlying molecular mechanisms haven't been fully explained. In this study, we investigated the influence of circUBAP2 on the NSCLC tumor cells. This study might provide novel therapeutic targets for NSCLC treatment. Clinical samples and NSCLC cell lines were used to investigate circUBAP2 expressions and their impact on tumor cell chemo-resistance. CCK8 and transwell assays were conducted to explore the differences of NSCLC tumor proliferation and migration capabilities affected by circUBAP2. Dual-luciferase reporter gene assay was performed to explore the detailed molecular mechanism of circUBAP2 regulation network. circUBAP2 exhibited significantly elevated average level in our clinical samples of NSCLC, compared with normal tissues. CircUBAP2 level was positively correlated with disease stage and metastatic status. circUBAP2 significantly enhanced the migration, proliferation and chemo-resistance of NSCLC cell lines. Further experiments indicated that circUBAP2 promoted malignant biological behavior of NSCLC tumor cells by targeting KLF4 through modulating miR-3182 expression. Our study demonstrated for the first time that circUBAP2 played an important role exacerbating malignant capabilities of NSCLC. circUBAP2-miR3182-KLF4 regulative network demonstrated in this study could be a novel therapeutic target for future NSCLC treatment.

E2F1-induced ferritin heavy chain 1 pseudogene 3 (FTH1P3) accelerates non-small cell lung cancer gefitinib resistance.

Long noncoding RNAs (lncRNAs) have been identified to be critical regulator for various human diseases and emerging evidence illustrate the essential function of lncRNAs in the non-small cell lung cancer (NSCLC). Here, our research team tried to identify the roles of lncRNA ferritin heavy chain 1 pseudogene 3 (FTH1P3) in the NSCLC, as well as its molecular mechanism. LncRNA microarray analysis revealed that ferritin heavy chain 1 pseudogene 3 (FTH1P3) was up-regulated in the gefitinib-resistant cells (PC9/GR). Clinically, lncRNA FTH1P3 high-expression was closely correlated with NSCLC patients' unfavorable prognosis. Gain and loss of functional experiments revealed that FTH1P3 promoted the proliferation and invasion of NSCLC cells in vitro, and FTH1P3 knockdown repressed the tumor growth in vivo. Mechanistically, transcription factor E2F1 accelerated the transcription of FTH1P3. RNA immunoprecipitation and chromatin immunoprecipitation experiments showed that FTH1P3 can recruit lysine-specific demethylase 1 (LSD1) and epigenetically repress the TIMP3, thereby accelerating the tumorigenesis of NSCLC. In summary, these findings suggest that FTH1P3 plays a critical role in the gefitinib resistance and progression of NSCLC, providing a potential novel prognostic marker for NSCLC.

Novel technique for lymphadenectomy along left recurrent laryngeal nerve during thoracoscopic esophagectomy.

BACKGROUND: In esophageal squamous carcinoma, lymphadenectomy along the left recurrent laryngeal nerve (RLN) is recommended owing to its highly metastatic potential. However, this procedure is difficult due to limited working space in the left upper mediastinum, and increases postoperative complications. AIM: To present a novel method for lymphadenectomy along the left RLN during thoracoscopic esophagectomy in the semi-prone position. METHODS: The fundamental concept of this novel method is to exfoliate a bilateral pedicled nerve flap, which is a two-dimensional membrane, which includes the left RLN, lymph nodes (LNs) along the left RLN, and tracheoesophageal vessels, by suspending the esophagus to the dorsal side and pushing the trachea to the ventral side (named "bilateral exposure method"). Then, the hollow-out method is performed to transform the two-dimensional membrane to a three-dimensional structure, in which the left RLN and tracheoesophageal vessels are easily distinguished and preserved during lymphadenectomy along the left RLN. This novel method was retrospectively evaluated in 116 consecutive patients with esophageal squamous carcinoma from August 2016 to February 2018. RESULTS: There were 58 patients in each group. No significant difference was found between the two groups in terms of age, gender, postoperative pneumonia, anastomotic fistula, and postoperative hospitalization. However, the number of dissected LNs along the left RLN in this novel method was significantly higher than that in the conventional method (4.17 ± 0.359 vs 2.93 ± 0.463, P = 0.0447). Moreover, the operative time and the rate of postoperative hoarseness in the novel method were significantly lower than those in the conventional method (306.0 ± 6.774 vs 335.2 ± 7.750, P = 0.0054; 4/58 vs 12/58, P = 0.0312). CONCLUSION: This novel method for lymphadenectomy along the left RLN during thoracoscopic esophagectomy in the semi-prone position is much safer and more effective.