Quantitative proteomics reveals the mechanisms of hydrogen-conferred protection against hyperoxia-induced injury in type II alveolar epithelial cells

LncRNA gadd7 promotes mitochondrial membrane potential decrease and apoptosis of alveolar type II epithelial cells by positively regulating MFN1 in an in vitro model of hyperoxia-induced acute lung injury

The mortality and morbidity rates of ovarian cancer (OC) are high, but the underlying mechanisms of OC have not been characterized. In this study, we determined the role of Rho GTPase Activating Protein 30 (ARHGAP30) in OC progression. We measured ARHGAP30 abundance in OC tissue samples and cells using immunohistochemistry (IHC) and RT-qPCR. EdU, transwell, and annexin V/PI apoptosis assays were used to evaluate proliferation, invasiveness, and apoptosis of OC cells, respectively. The results showed that ARHGAP30 was overexpressed in OC tissue samples and cells. Inhibition of ARHGAP30 suppressed growth and metastasis of OC cells, and enhanced  apoptosis. Knockdown of ARHGAP30 in OC cells significantly inhibited the PI3K/AKT/mTOR pathway. Treatment with the PI3K/AKT/mTOR pathway inhibitor buparlisib simulated the effects of ARHGAP30 knockdown on growth, invasiveness, and apoptosis of OC cells. Following buparlisib treatment, the expression levels of p-PI3K, p-AKT, and p-mTOR were significantly decreased. Furthermore, buparlisib inhibited the effects of ARHGAP30 upregulation on OC cell growth and invasiveness. In conclusion, ARHGAP30 regulated the PI3K/AKT/mTOR pathway to promote progression of OC.

P311 knockdown alleviates hyperoxia-induced injury by inactivating the Smad3 signaling pathway in type II alveolar epithelial cells

P311 is associated with alveolar formation and development. However, the role and possible mechanism of P311 in hyperoxia-induced injury in type II alveolar epithelial cells (AEC II) need to be elucidated. In our study, rat AEC II (RLE-6TN) were exposure to normoxia (21% O₂ and 5% CO₂) or hyperoxia (95% O₂ and 5% CO₂) for 24 h, followed by determination of P311 expression. After knockdown of P311 and hyperoxic treatment, cell viability, cell cycle progression, apoptosis and the Smad3 signaling pathway were examined. Rat AEC II were pretreated with SIS3 HCl for 4 h and then subjected to P311 overexpression plasmid transfection and hyperoxic exposure. Then, cell viability, apoptosis and the Smad3 signaling pathway were determined. The results showed that hyperoxic exposure significantly elevated P311 levels in rat AEC II. P311 knockdown increased cell viability, accelerated cell cycle progression and inhibited apoptosis, as well as suppression of the Smad3 signaling pathway in hyperoxia-exposed AEC II. Additionally, we found that P311 overexpression enhanced the effects of hyperoxia. Interestingly, SIS3 HCl incubation blocked the effects of P311 overexpression on rat AEC II function under hyperoxic condition, as evidenced by an increase in cell viability, and suppressions of apoptosis and the Smad3 signaling pathway. These results indicate that P311 knockdown may ameliorate hyperoxia-induced injury by inhibiting the Smad3 signaling pathway in rat AEC II. P311 may be a novel target for the treatment of hyperoxia-induced lung injury and even bronchopulmonary dysplasia (BPD).

Pulmonary endogenous progenitor stem cell subpopulation: Physiology, pathogenesis, and progress

Lungs are structurally and functionally complex organs consisting of diverse cell types from the proximal to distal axis. They have direct contact with the external environment and are constantly at risk of various injuries. Capable to proliferate and differentiate, pulmonary endogenous progenitor stem cells contribute to the maintenance of lung structure and function both under homeostasis and following injuries. Discovering candidate pulmonary endogenous progenitor stem cell types and underlying regenerative mechanisms provide insights into therapeutic strategy development for lung diseases. In this review, we reveal their compositions, roles in lung disease pathogenesis and injury repair, and the underlying mechanisms. We further underline the advanced progress in research approach and potential therapy for lung regeneration. We also demonstrate the feasibility and prospects of pulmonary endogenous stem cell transplantation for lung disease treatment.

Molecular hydrogen is a potential protective agent in the management of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome, which is a more severe form of ALI, are life-threatening clinical syndromes observed in critically ill patients. Treatment methods to alleviate the pathogenesis of ALI have improved to a great extent at present. Although the efficacy of these therapies is limited, their relevance has increased remarkably with the ongoing pandemic caused by the novel coronavirus disease 2019 (COVID-19), which causes severe respiratory distress syndrome. Several studies have demonstrated the preventive and therapeutic effects of molecular hydrogen in the various diseases. The biological effects of molecular hydrogen mainly involve anti-inflammation, antioxidation, and autophagy and cell death modulation. This review focuses on the potential therapeutic effects of molecular hydrogen on ALI and its underlying mechanisms and aims to provide a theoretical basis for the clinical treatment of ALI and COVID-19.

Constitutive transgenic alpha-Klotho overexpression enhances resilience to and recovery from murine acute lung injury

AIMS

Normal lungs do not express alpha-Klotho (Klotho) protein but derive cytoprotection from circulating soluble Klotho. It is unclear whether chronic supranormal Klotho levels confer additional benefit. To address this, we tested the age-related effects of Klotho overexpression on acute lung injury (ALI) and recovery.

METHODS

Transgenic Klotho-overexpressing (Tg-Kl) and wild-type (WT) mice (2 and 6 months old) were exposed to hyperoxia (95% O₂; 72 h) then returned to normoxia (21% O₂; 24 h) (Hx-R). Control mice were kept in normoxia. Renal and serum Klotho, lung histology, and bronchoalveolar lavage fluid oxidative damage markers were assessed. Effects of hyperoxia were tested in human embryonic kidney cells stably expressing Klotho. A549 lung epithelial cells transfected with Klotho cDNA or vector were exposed to cigarette smoke; lactate dehydrogenase and double-strand DNA breaks were measured.

RESULTS

Serum Klotho decreased with age. Hyperoxia suppressed renal Klotho at both ages and serum Klotho at 2-months of age. Tg-Kl mice at both ages and 2-months-old WT mice survived Hx-R; 6-months-old Tg-Kl mice showed lower lung damage than age-matched WT mice. Hyperoxia directly inhibited Klotho expression and release in vitro; Klotho transfection attenuated cigarette smoke-induced cytotoxicity and DNA double-strand breaks in lung epithelial cells.

CONCLUSIONS

Young animals with chronic high baseline Klotho expression are more resistant to ALI. Chronic constitutive Klotho overexpression in older Tg-Kl animals attenuates hyperoxia-induced lung damage and improves survival and short-term recovery despite an acute reduction in serum Klotho level during injury. We conclude that chronic enhancement of Klotho expression increases resilience to ALI.

A clinical study on plasma biomarkers for deciding the use of adjuvant corticosteroid therapy in bronchopulmonary dysplasia of premature infants

Objective: The study was designed to investigate some plasma markers which help us to decide the use of adjuvant corticosteroid therapy in bronchopulmonary dysplasia (BPD) of premature infants. Methods: Thirty BPD infants were treated by dexamethasone. Among these cases, dexamethasone was significant effective in 10 cases, and no significant effective in 20 cases. These patients were divided into two groups as the significant effect (SE) group (n=10) and the non-significant effect (NE) group (n=20) according to the curative effect of dexamethasone. Fifteen non-BPD infants with gestational age and gender matching were selected as the control group. Plasma samples before and after dexamethasone treatment were collected from three infants chosen randomly from SEG for the data-independent acquisition (DIA) analysis. ELISA was further used to detect the levels of differential proteins LRP1 and S100A8 in all individuals, including SE, NE and control groups. Results: DIA analysis results showed that after dexamethasone treatment, there were a total of 52 plasma proteins that showed significant differences, of which 43 proteins were down-regulated and 9 proteins were up-regulated. LRP1 and S100A8 were two plasma proteins that were significantly changed after dexamethasone treatment. Compared with the control group, plasma LRP1 was significantly increased in BPD. Interestingly, the plasma concentration of LRP1 in the NE group was significantly higher than that in the SE group. S100A8, as an indicator of plasma inflammation, was significantly higher in BPD than the control group. Unlike LRP1, there was no significantly difference between the SE and NE group (P=0.279) before dexamethasone treatment. Conclusion: Elevated plasma LRP1 and S100A8 in BPD infants are two indicators that correlated with the efficacy of dexamethasone, and might be used as biomarkers for deciding the use of adjuvant corticosteroids therapy in the BPD.