Cell Apoptosis In Lung Tissues Research Articles

Active fractions from Jingfang Baidu Powder alleviate Klebsiella-induced Pneumonia by inhibiting TLR4/Myd88-ERK signaling pathway

Ethnopharmacological relevanceJingfang Baidu Powder (JFBDP) is a classic traditional Chinese medicine prescription. Although Jingfang Baidu powder obtained a general consensus on clinical efficacy in treating pneumonia, there were many Chinese herbal drugs in formula, complex components, and large oral dosage, which brings certain obstacles to clinical application. Aim of the studyTherefore, screening of the active fraction that exerts anti-pneumonia helps improve the pharmaceutical preparation, improve the treatment compliance of patients, and further contribute to the clinical application, and the screening of the new active ingredients with anti-pneumonia. The histopathological observation, real-time quantitative PCR, western blotting, and immunofluorescence were applied to evaluate the anti-pneumonia efficacy of active fractions from JFBDP. ResultsThree fractions from JFBDP inhibit the gene expression of IL-1β, IL-10, CCL3, CCL5, and CCL22 in lung tissue infected by Klebsiella at various degrees, and presented a good dose-response relationship. JF50 showed stronger anti-inflammatory effects among three fractions including JF30, JF50, and JF75. Besides, JF50 significantly reduced the protein expression of TLR4 and Myd88 in lung tissue infected with Klebsiella, and it also significantly inhibited p-ERK and p–NF–κB p65. JF50 significantly inhibits the protein expression of Caspase 3, Caspase 8, and Caspase 9 in lung tissue infected with Klebsiella at the dose of 25 mg/kg and 50 mg/kg. ConclusionJF50 improves lung pathological damage in Klebsiella pneumonia mice by inhibiting the TLR4/Myd88/NF-κB-ERK signaling pathway, and inhibiting apoptosis of lung tissue cells. These findings provide a reference for further exploring the active substance basis of Jingfang Baidu Powder in treating bacterial pneumonia.

Urolithin A exerts a protective effect on lipopolysaccharide-induced acute lung injury by regulating HMGB1-mediated MAPK and NF-κB signaling pathways.

Acute lung injury (ALI) is a severe inflammatory disorder that has a high morbidity and mortality rate. Urolithin A (UA) is reported to have anti-inflammatory and anti-oxidative effects in ALI. However, its molecular mechanisms in ALI remain to be explored. Mice and BEAS-2B cells were administrated with lipopolysaccharide (LPS) to mimic the ALI model in vivo and in vitro. Hematoxylin-eosin (HE) staining was used to detect the pathological injury of lung tissues. The levels of proinflammatory cytokines in bronchoalveolar lavage fluid (BALF) and culture supernatant and the levels of oxidative stress markers in lung tissues were measured using ELISA. DCFH-DA probe was used to assess the reactive oxygen species (ROS) level. TUNEL staining and flow cytometry were performed to determine cell apoptosis. The key targets and pathways were confirmed by immunohistochemistry (IHC) and western blot. UA suppressed the pathologic damage, wet/dry weight ratio, and total protein and inflammatory cells in BALF. UA decreased neutrophil infiltration and proinflammatory cytokines production. UA reduced the level of malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in pulmonary tissues. UA also inhibited cell apoptosis in lung tissues by decreasing Bax expression and increasing Bcl-2 expression. In addition, UA suppressed LPS-induced inflammatory factor production, ROS level, and cell apoptosis in BEAS-2B. Importantly, UA decreased the expression of HMGB1 in LPS-treated mice and BEAS-2B cells. HMGB1 overexpression greatly abrogated the inhibition of UA on inflammation, ROS, and cell apoptosis in LPS-administrated BEAS-2B. Furthermore, UA treatment suppressed the phosphorylated levels of p38, JNK, ERK, and p65 in LPS-administrated mice and BEAS-2B cells. UA alleviated lung inflammation, oxidative stress, and apoptosis in ALI by targeting HMGB1 to inactivate the MAPK/NF-κB signaling, suggesting the potential of UA to treat ALI.

Theacrine alleviates inflammation and lung injury in septic mice by mediating SIRT3

Purpose: To evaluate the effect of theacrine on sepsis progression and sepsis-induced lung injury and its mechanism of action.
 Methods: Lung injury model of lipopolysaccharide (LPS)-induced sepsis was made in the mice by injected with 3 mg/kg LPS dissolved in 50 μL PBS or only PBS (control group = 10). The remaining three groups (divided into ten mice per group) were administered theacrine (10, 20, and 40 mg/kg), by oral gavage 1 hour after LPS treatment. Hematoxylin and eosin (H&E) staining was performed to confirm the effect of theacrine on lung injury. Quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA) were conducted to determine inflammatory and oxidative stress factors. TUNEL as well as immunoblot assays were carried to confirm its effect on apoptosis and mechanism of action.
 Results: Theacrine significantly improved lung injury as well as lung relief score in LPS-induced sepsis mice (p < 0.01) and it significantly reversed the increased levels of inflammatory cytokines in a dose-dependent manner in LPS-induced sepsis mice (p < 0.01), In addition, theacrine administration significantly reduced the increased intensity of ROS and MDA levels, and significantly improved the levels of SOD in lung tissues (p < 0.01). Furthermore, it improved LPS-induced apoptosis of lung tissue cells and alleviated lung injury by significantly activating SIRT3 pathway (p < 0.01).
 Conclusion: Theacrine alleviates inflammation and lung injury in septic mice by mediating SIRT3, thereby making it a potential lead in the development of drugs against sepsis-related inflammation and lung injury.

Ginkgo biloba Extract 50 (GBE50) Exerts Antifibrotic and Antioxidant Effects on Pulmonary Fibrosis in Mice by Regulating Nrf2 and TGF-β1/Smad Pathways.

Pulmonary fibrosis (PF) is a progressive lung disorder with a poor prognosis. GBE50 is a new standardized Ginkgo biloba extract that has been widely used in cardiovascular diseases. However, the protective mechanism of GBE50 against PF remains to be elucidated. C57BL/6J mice were treated with bleomycin (Bleo) to induce PF in the presence or absence of GBE50. Protein content in bronchoalveolar lavage fluid (BALF) and wet weight/dry weight ratio were examined for analysis of pulmonary edema. Hematoxylin-eosin staining and Masson trichrome staining were used for histopathological observation of murine lung tissues. Ashcroft score was used for semi-quantitation of lung fibrosis degree. RT-qPCR was utilized for assessing mRNA levels of pro-fibrotic mediators in lung tissues. TUNEL staining was implemented for cell apoptosis assessment. The levels of oxidative stress- and inflammation-related markers were evaluated by corresponding commercial assay kits. Western blotting was used to evaluate levels of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling- and transforming growth factor (TGF)-β1/SMAD signaling-related proteins. GBE50 alleviated lung injury and severity of fibrosis, reduced collagen deposition and cell apoptosis in lung tissues, and suppressed inflammatory response and oxidative stress injury in Bleo-stimulated PF mice. GBE50 activated Nrf2 signaling pathway and inactivated TGF-β1/SMAD signaling pathway in the lungs of Bleo-induced PF mice. Inhibition of Nrf2 signaling reversed GBE50-mediated inactivation of TGF-β1/SMAD signaling and attenuation of inflammation and oxidative stress in Bleo-induced PF mice. GBE50 protects against Bleo-induced PF in mice by mitigating fibrosis, inflammation and oxidative stress via Nrf2 and TGF-β1/SMAD signaling pathways.

Aqueous extract of Epimedium sagittatum mitigates pulmonary fibrosis in mice

This study aims to investigate the intervention effect of the aqueous extract of Epimedium sagittatum Maxim on the mouse model of bleomycin(BLM)-induced pulmonary fibrosis, so as to provide data support for the clinical treatment of pulmonary fibrosis. Ninety male C57BL/6N mice were randomized into normal(n=10), model(BLM, n=20), pirfenidone(PFD, 270 mg·kg~(-1), n=15), and low-, medium-, and high-dose E. sagittatum extract(1.67 g·kg~(-1), n=15; 3.33 g·kg~(-1), n=15; 6.67 g·kg~(-1), n=15) groups. The model of pulmonary fibrosis was established by intratracheal instillation of BLM(5 mg·kg~(-1)) in the other five groups except the normal group, which was treated with an equal amount of normal saline. On the day following the modeling, each group was treated with the corresponding drug by gavage for 21 days. During this period, the survival rate of the mice was counted. After gavage, the lung index was calculated, and the morphology and collagen deposition of the lung tissue were observed by hematoxylin-eosin(HE) and Masson staining, respectively. The levels of reactive oxygen species(ROS) in lung cell suspensions were measured by flow cytometry. The levels of glutathione peroxidase(GSH-Px), total superoxide dismutase(T-SOD), and malondialdehyde(MDA) the in lung tissue were measured. Terminal-deoxynucleoitidyl transferase-mediated nick-end labeling(TUNEL) was employed to examine the apoptosis of lung tissue cells. The content of interleukin-6(IL-6), chemokine C-C motif ligand 2(CCL-2), matrix metalloproteinase-8(MMP-8), transforming growth factor-beta 1(TGF-β1), alpha-smooth muscle actin(α-SMA), E-cadherin, collagen Ⅰ, and fibronectin in the lung tissue was measured by enzyme-linked immunosorbent assay(ELISA). The expression levels of F4/80, Ly-6G, TGF-β1, and collagen Ⅰ in the lung tissue were determined by immunohistochemistry. The mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue were determined by qRT-PCR. The content of hydroxyproline(HYP) in the lung tissue was determined by alkaline hydrolysation. The expression of α-SMA and E-cadherin was detected by immunofluorescence, and the protein levels of α-SMA, vimentin, E-cadherin in the lung tissue were determined by Western blot. The results showed the aqueous extract of E. sagittatum increased the survival rate, decreased the lung index, alleviated the pathological injury, collagen deposition, and oxidative stress in the lung tissue, and reduced the apoptotic cells. Furthermore, the aqueous extract of E. sagittatum down-regulated the protein levels of F4/80 and Ly-6G and the mRNA levels of CCL-2, IL-6, and MMP-7 in the lung tissue, reduced the content of IL-6, CCL-2, and MMP-8 in the alveolar lavage fluid. In addition, it lowered the levels of HYP, TGF-β1, α-SMA, collagen Ⅰ, fibronectin, and vimentin, and elevated the levels of E-cadherin in the lung tissue. The aqueous extract of E. sagittatum can inhibit collagen deposition, alleviate oxidative stress, and reduce inflammatory response by regulating the expression of the molecules associated with epithelial-mesenchymal transition, thus alleviating the symptoms of bleomycin-induced pulmonary fibrosis in mice.

Selenium-ruthenium complex blocks H1N1 influenza virus-induced cell damage by activating GPx1/TrxR1.

Background: Influenza A (H1N1) virus is an acute respiratory infectious disease that causes massive morbidity and mortality worldwide. As an essential trace element, selenium is widely applied in the treatment of various diseases because of its functions of enhancing immune response, antioxidant and antiviral mutation. In this study, we constructed the selenium-containing metal complex drug delivery system Ru(biim)(PhenSe)2 (RuSe), and investigated the anti-influenza virus efficacy and the potential antiviral mechanism for RuSe. Methods: The inhibitory effect of RuSe on influenza-mediated apoptosis was examined by cell count assay, cell cycle assay, Annenxin-V assay, TUNEL-DAPI assay and reactive oxygen species level determination. Virulence assay, PCR and neuraminidase inhibition assay revealed the inhibition of RuSe on influenza virus. At the level of animal experiments, two animal models were used to clarify the role of RuSe through HE staining, immunohistochemical staining, cytokine determination, selenium metabolism determination and selenium protein expression level determination. Results: The results of this study confirm that RuSe enhances the expression levels of selenium proteins GPx1 and TrxR1 by regulating selenium metabolism, thereby inhibiting viral replication and assembly and regulating virus-mediated mitochondria-related apoptosis. On the other hand, animal experiments show that RuSe can reduce lung tissue inflammation and inhibit lung tissue cell apoptosis in mice, and improve the survival state of mice. In addition, RuSe significantly improves the low immune response of Se-deficient mice by regulating selenium metabolism, and effectively alleviated lung fibrosis and lung tissue apoptosis in Se-deficient mice. Conclusions: This study suggests that RuSe provides a promising new approach for the clinical treatment of influenza virus.

Protective effects of Isodon Suzhouensis extract and glaucocalyxin A on chronic obstructive pulmonary disease through SOCS3–JAKs/STATs pathway

AbstractChronic obstructive pulmonary disease (COPD) is an irreversible disease with the leading causes of morbidity, mortality, and several physical limitations. Isodon Suzhouensis is a unique Chinese medicinal plant used for both medicine and food. It possesses strong anti‐inflammatory effects that may treat COPD. Considering the fact that the effects of Isodon Suzhouensis extract (WZZE) and its active ingredient glaucocalyxin A (GLA) on COPD have never been reported before, this study aimed to investigate the effects of WZZE and GLA against COPD and its underlying mechanistic pathway in COPD model rats or in CSE‐induced NR8383 cells. The variation in lung physiology was measured through spirometry while histopathological changes were studied via H&E staining of the COPD model rats lung samples. The levels of cytokine and other immunomodulatory proteins were determined by ELISA. Apoptosis of lung tissue cells was detected by TUNEL staining. Western blot and immunohistochemistry were used to detect the expression of related pathways and other proteins. The results show that WZZE improved the relevant lung function indicators, while restoring the activity of immunoglobulins (Ig A, IgG) and inhibiting the levels of TNF‐α and IL‐1β in serum and bronchoalveolar lavage fluid, thereby improving the body's immunity and inhibiting inflammation of the airways and lungs, slowing the progression of COPD. The results of H&E staining indicated that WZZE is capable of improving the pathological injury associated with COPD. In addition, the administration of WZZE reduced the expression of MUC5AC protein induced and the apoptosis rate of lung tissue cells in COPD model rats. The results also showed that WZZE significantly increased the expression of SOCS3 and inhibited the expression of JAKs/STATs pathway‐related proteins in COPD rats. In addition, GLA can also upregulate the expression of SOCS3 protein, inhibit JAKs/STATs pathway, inhibit the expression level of MUC5AC, upregulate the expression level of immunoglobulin, and downregulate the expression level of proinflammatory factors in NR8383 cells induced by CSE. Present study findings suggest that WZZE and GLA may ameliorate the progression of COPD via the SOCS3–JAKs/STATs pathway in COPD rats or in CSE‐induced NR8383.

Nicotinamide Mononucleotide Attenuates LPS-Induced Acute Lung Injury With Anti-Inflammatory, Anti-Oxidative and Anti-Apoptotic Effects

IntroductionNicotinamide mononucleotide (NMN) is a nucleotide that is commonly recognized for its role as an intermediate of nicotinamide adenine dinucleotide (NAD+) biosynthesis with multiple pharmacological effects. The purpose of this study was to evaluate the protective effect of nicotinamide mononucleotide (NMN) against lipopolysaccharide (LPS)–induced acute lung injury (ALI). MethodsWe investigated the effect of NMN on ALI-induced inflammatory response, oxidative stress, and cell apoptosis. The ALI mouse model was performed by injecting LPS intratracheally at a dose of 10 mg/kg in 50 μL saline. Flow cytometry was used to detect neutrophil infiltration in bronchoalveolar lavage fluid (BALF), and ELISA was used to detect the contents of inflammatory cytokines TNF-α, IL-1β and IL-6 in BALF. Oxidative stress was evaluated by determining the superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in lung tissue. ROS formation was analyzed by immunofluorescence. Western blotting was performed to detect apoptotic levels and p38MAPK/NF-κB phosphorylation levels in lung tissue. ResultsIn the ALI mouse model, NMN showed a significant therapeutic effect compared to the LPS group. NMN attenuated the pathological damage and cell apoptosis in lung tissue, decreased the levels of TNF-α, IL-1β, and IL-6 in BALF, and reduced the number of total cells and neutrophils in BALF. In addition, NMN attenuated the LPS-induced elevation of dry-to-wet ratio, MDA content, p38 MAPK and p65 NF-κB phosphorylation levels, and the SOD activity was increased by NMN treatment. ConclusionsIn conclusion, the present study showed that NMN exerted a protective effect on LPS-induced ALI with anti-inflammatory, antioxidative, and antiapoptotic effects.

MicroRNA-21 protects against sepsis-induced acute lung injury by targeting phosphatase and tensin homolog in mice

Introduction: Sepsis can cause acute lung injury (ALI), one of the leading causes of death in critically ill patients. The underlying mechanisms of sepsis-induced acute lung injury include excessive inflammation, oxidative stress, cell apoptosis, pulmonary edema, and lung tissue dysfunction. Recent studies have shown that miRNA-21 (miR-21) plays a vital role in sepsis-induced acute kidney injury. Relatively few studies have focused on the protective effects of ALI. This study aimed to determine the potential role of miR-21 in sepsis-induced ALI. Methods: We performed quantitative real-time polymerase chain reaction in a septic mouse model induced by cecal ligation and puncture (CLP) and found that miR-21 expression was upregulated. We then transfected the miR-21 precursor to upregulate miR-21 expression and miR-21 inhibitor to downregulate miR-21 expression. The sham group was exposed only to the cecum. ALI was induced by CLP, and the pre-miR-21+ALI and anti-miR-21+ALI groups were treated with miR-21 precursor or miR-21 inhibitor in the caudal vein before CLP. Pre-miR-21+ALI+PTEN inhibition (Pre-miR-21+ALI+PI) and anti-miR-21+ALI+PTEN inhibition (Anti-miR-21+ALI+PI) groups were treated with PTEN inhibition into the caudal vein after miR-21 transfection. Inflammatory cytokines, oxidative stress indicators, lung tissue cell apoptosis, oxygenation index (OI), lung wet/dry weight ratio, and lung pathological changes in the lung were observed in each group. Results: Compared with ALI mice, inflammatory response, oxidative stress indicators, lung tissue cell apoptosis, and the degree of lung injury were remarkably alleviated in Pre-miR-21+ALI mice and aggravated in Anti-miR-21+ALI mice. Western blot analysis showed that phosphatase and tensin homolog (PTEN) protein expression was decreased in CLP-treated mics. PTEN protein expression was decreased in the Pre-miR-21+ALI group but increased in the Anti-miR-21+ALI group. Moreover, the effect of miR-21 on anti-inflammatory, anti-oxidative stress, and anti-apoptosis enhanced after PTEN inhibition. Conclusion: This study revealed that miR-21 has a protective effect in sepsis-induced ALI by regulating PTEN in mice.

Stellate Ganglion Block Combined with Dexmedetomidine Protects Obese Rats from Lipopolysaccharide-Induced Acute Lung Injury.

Objective To investigate the effect and mechanism of combined stellate ganglion block (SGB) and dexmedetomidine (Dex) in obesity-related acute lung injury. Methods Thirty-six 4-week-old male Wistar rats were randomly divided into 6 groups, each with 6 rats: blank group (Control), high-fat diet group (HFD), high-fat + lipopolysaccharide (LPS)-induced acute lung injury group (HFD + LPS), SGB group, Dex group, and SGB + Dex group. H&E staining detected the pathological structure of rat lung tissue. TUNEL staining was used to examine cell apoptosis in lung tissue. Oxidative factors were accessed by biochemical reagents. ELISA was employed to measure the levels of TNF-α, IL-1β, and MCP1 in rat alveolar lavage fluid. Western blot detected the protein expression of glucose-regulated Protein 78 (GRP78), C/EBP homologous protein (CHOP), protein kinase R-like endoplasmic reticulum kinase (PERK), and p-PERK in lung tissue. Results The body weight of rats in the HFD group was higher than that in the control group. The use of SGB or Dex alone could significantly reduce the rate of pulmonary edema and lung cell apoptosis in HFD-induced obese rats and reduce MPO, TNF-α, IL-1β, and MCP1 levels, increasing the activity of SOD and GSH-Px. In addition, using SGB or Dex alone can also significantly reduce the protein expression levels of GRP78, CHOP, and p-PERK. The combined use of SGB and Dex can enhance the above effects. Conclusion The combined use of SGB and Dex can protect against obesity-related acute lung injury and is more effective than using SGB or Dex alone.

SEMA3A protects against hyperoxia-induced lung injury in a bronchopulmonary dysplasia model of newborn rat by inhibiting ERK pathway.

Hyperoxia induces lung injury through lung inflammation in premature infants, leading to bronchopulmonary dysplasia (BPD). Semaphorin 3A (SEMA3A) participates in diverse biological processes, including cell migration, angiogenesis, and inflammation. The effect of SEMA3A on hyperoxic lung injury of neonatal rats with BPD was investigated in this study. Neonatal rats with BPD were established through hyperoxia treatment. Hematoxylin-eosin staining was used to evaluate histopathological analysis in lung tissues. SEMA3A expression was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot assay. Adeno-associated virus (AAV)-mediated over-expression of SEMA3A (AAV-SEMA3A) was administrated into hyperoxia-induced rats, and apoptosis was evaluated by TUNEL staining. Levels of inflammatory cytokines were investigated by enzyme-linked-immunosorbent serologic assay (ELISA). Hyperoxia-induced histopathological changes in lung tissue reduced alveolar number and enhanced alveolar interval and alveolar volume. SEMA3A was downregulated in lung tissue of hyperoxia-induced rats. AAV-SEMA3A injection attenuated hyperoxia-induced cell apoptosis in lung tissues by increasing Bcl-2 and decreasing Bax and cleaved caspase-3. Moreover, the enhanced levels of Interleukin (IL)-1β, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor-α (TNF-α) in hyperoxia-induced rats were restored by AAV-SEMA3A injection by the downregulation of nuclear factor kappa B (NF-κB) phosphorylation. AAV-SEMA3A injection also ameliorated histopathological changes in lung tissues of hyperoxia-induced rats by increasing the number of radial alveolar count and decreasing the volume of mean linear intercept. Besides, the protein expression levels of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation were reduced in hyperoxia-induced rats post-AAV-SEMA3A injection. Ectopical expression of SEMA3A suppressed hyperoxia-induced apoptosis and inflammation in neonatal rats, and ameliorated the histopathological changes through inactivation of ERK/JNK pathway.

Mechanism of action of Yupingfeng capsule for combined allergic rhinitis and asthma syndrome via the TLR4/NF-KB pathway

We aimed to investigate the mechanism of action of Yupingfeng capsule for combined allergic rhinitis and asthma syndrome (CARAS) via the TLR4/NF-KB pathway. Rats were divided into normal, model, experimental and control groups. CARAS model was established through sensitization with ovalbumin (OVA) and Al(OH)3, and intranasal instillation and atomization of OVA. Then experimental and control groups were given Yupingfeng capsules and dexamethasone at 2 mg/kg by gavage once a day for 14 consecutive days, while normal and model groups were intraperitoneally injected with an equal dose of normal saline. Their nasal symptoms were scored, and cell apoptosis in lung tissues was observed by TUNEL staining. Serum levels of interleukin-5 (IL-5) and IL-13 were detected by ELISA, and TLR4 and NF-κB expressions in lung and nasal mucosa tissues were measured by Western blotting. The score of nasal symptoms, levels of IL-5 and IL-13, cell apoptosis rate in lung tissues, and expressions of TLR4 and NF-KB were significantly lower in experimental and control groups than in model group (P<0.05). Yupingfeng capsule can obviously suppress the release of inflammatory factors and the apoptosis of cells as well as relieve the symptoms of CARAS rats probably by inhibiting the TLR4/NF-κB pathway.

Propofol attenuates lung ischemia/reperfusion injury though the involvement of the MALAT1/microRNA-144/GSK3\u03b2 axis

BackgroundPropofol, an intravenous anesthetic, was proven to protect against lung ischemia/reperfusion (I/R) injury. However, the detailed mechanism of Propofol in lung I/R injury is still elusive. This study was designed to explore the therapeutic effects of Propofol, both in vivo and in vitro, on lung I/R injury and the underlying mechanisms related to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-144 (miR-144)/glycogen synthase kinase-3β (GSK3β).MethodsC57BL/6 mice were used to establish a lung I/R injury model while pulmonary microvascular endothelial cells (PMVECs) were constructed as hypoxia/reperfusion (H/R) cellular model, both of which were performed with Propofol treatment. Gain- or loss-of-function approaches were subsequently employed, followed by observation of cell apoptosis in lung tissues and evaluation of proliferative and apoptotic capabilities in H/R cells. Meanwhile, the inflammatory factors, autophagosomes, and autophagy-related proteins were measured.ResultsOur experimental data revealed that Propofol treatment could decrease the elevated expression of MALAT1 following I/R injury or H/R induction, indicating its protection against lung I/R injury. Additionally, overexpressing MALAT1 or GSK3β promoted the activation of autophagosomes, proinflammatory factor release, and cell apoptosis, suggesting that overexpressing MALAT1 or GSK3β may reverse the protective effects of Propofol against lung I/R injury. MALAT1 was identified to negatively regulate miR-144 to upregulate the GSK3β expression.ConclusionOverall, our study demonstrated that Propofol played a protective role in lung I/R injury by suppressing autophagy and decreasing release of inflammatory factors, with the possible involvement of the MALAT1/miR-144/GSK3β axis.

The α2AR/Caveolin-1/p38MAPK/NF-κB axis explains dexmedetomidine protection against lung injury following intestinal ischaemia-reperfusion.

Intestinal ischaemia‐reperfusion (I/R) injury can result in acute lung injury due to ischaemia and hypoxia. Dexmedetomidine (Dex), a highly selective alpha2‐noradrenergic receptor (α2AR) agonist used in anaesthesia, is reported to regulate inflammation in organs. This study aimed to investigate the role and mechanism of Dex in lung injury caused by intestinal I/R. After establishing a rat model of intestinal I/R, we measured the wet‐to‐dry specific gravity of rat lungs upon treatments with Dex, SB239063 and the α2AR antagonist Atipamezole. Moreover, injury scoring and histopathological studies of lung tissues were performed, followed by ELISA detection on tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐1β and IL‐6 expression. Correlation of Caveolin‐1 (Cav‐1) protein expression with p38, p‐p38, p‐p65 and p65 in rat lung tissues was analysed, and the degree of cell apoptosis in lung tissues after intestinal I/R injury was detected by TUNEL assay. The lung injury induced by intestinal I/R was a dynamic process. Moreover, Dex had protective effects against lung injury by mediating the expression of Cal‐1 and α2A‐AR. Specifically, Dex promoted Cav‐1 expression via α2A‐AR activation and mitigated intestinal I/R‐induced lung injury, even in the presence of Atipamezole. The protective effect of Dex on intestinal I/R‐induced lung injury was also closely related to α2A‐AR/p38 mitogen‐activated protein kinases/nuclear factor‐kappaB (MAPK/NF‐κB) pathway. Dex can alleviate pulmonary inflammation after in intestinal I/R by promoting Cav‐1 to inhibit the activation of p38 and NF‐κB. In conclusion, Dex can reduce pulmonary inflammatory response even after receiving threats from both intestinal I/R injury and Atipamezole.

Blocking SphK1/S1P/S1PR1 Signaling Pathway Alleviates Lung Injury Caused by Sepsis in Acute Ethanol Intoxication Mice.

Acute ethanol intoxication increases the risk of sepsis and aggravates the symptoms of sepsis and lung injury. Therefore, this study aimed to explore whether sphingosine kinase 1 (SphK1)/sphingosine-1-phosphate (S1P)/S1P receptor 1 (S1PR1) signaling pathway functions in lung injury caused by acute ethanol intoxication-enhanced sepsis, as well as its underlying mechanism. The acute ethanol intoxication model was simulated by intraperitoneally administering mice with 32% ethanol solution, and cecal ligation and puncture (CLP) was used to construct the sepsis model. The lung tissue damage was observed by hematoxylin-eosin (H&E) staining, and the wet-to-dry (W/D) ratio was used to evaluate the degree of pulmonary edema. Inflammatory cell counting and protein concentration in bronchoalveolar lavage fluid (BALF) were, respectively, detected by hemocytometer and bicinchoninic acid (BCA) method. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-18 in BALF were detected by their commercial enzyme-linked immunosorbent assay (ELISA) kits. The myeloperoxidase (MPO) activity and expression of apoptosis-related proteins and SphK1/S1P/S1PR1 pathway-related proteins were, respectively, analyzed by MPO ELISA kit and Western blot analysis. The cell apoptosis in lung tissues was observed by TUNEL assay. Acute ethanol intoxication (EtOH) decreased the survival rate of mice and exacerbated the lung injury caused by sepsis through increasing pulmonary vascular permeability, neutrophil infiltration, release of inflammatory factors, and cell apoptosis. In addition, EtOH could activate the SphK1/S1P/S1PR1 pathway in CLP mice. However, PF-543, as a specific inhibitor of SphK1, could partially reverse the deleterious effects on lung injury of CLP mice. PF-543 alleviated lung injury caused by sepsis in acute ethanol intoxication rats by suppressing the SphK1/S1P/S1PR1 signaling pathway.

Upregulation of endothelial cell-derived exosomal microRNA-125b-5p protects from sepsis-induced acute lung injury by inhibiting topoisomerase II alpha.

ObjectiveEmerging evidence has revealed that exosomal microRNAs (miRNAs) are implicated in human diseases. However, role of exosomal miR-125b-5p in sepsis-induced acute lung injury (ALI) remains further explored. We focused on the effect of exosomal miR-125b-5p on ALI progression via targeting topoisomerase II alpha (TOP2A).MethodsThe ALI mouse models were established by cecal ligation and perforation, which were then treated with miR-125b-5p agomir or overexpressed TOP2A. Next, the pathological structure of ALI mouse lung tissues were observed, miR-125b-5p, TOP2A and vascular endothelial growth factor (VEGF) expression was determined, and the lung water content, inflammatory response, protein content in bronchoalveolar lavage fluid (BALF) and cell apoptosis in ALI mouse lung tissues were assessed. Exosomes were extracted from endothelial cells (ECs) and identified, which were then injected into the modeled mice to observe their roles in ALI. The targeting relationship between miR-125b-5p and TOP2A was confirmed.ResultsMiR-125b-5p was downregulated while TOP2A was upregulated in ALI mice. MiR-125b-5p elevation or ECs-derived exosomes promoted VEGF expression, improved pathological changes and restrained lung water content, inflammatory response, protein content in BALF and cell apoptosis in lung tissues ALI mice. TOP2A overexpression reversed the repressive role of miR-125b-5p upregulation in ALI, while downregulated miR-125b-5p abrogated the effect of ECs-derived exosomes on ALI. TOP2A was confirmed as a direct target gene of miR-125b-5p.ConclusionOur study indicates that ECs-derived exosomes overexpressed miR-125b-5p to protect from sepsis-induced ALI by inhibiting TOP2A, which may contribute to ALI therapeutic strategies.

Effects of Ambroxol Hydrochloride on Lung Tissue Cell Apoptosis and Vascular Remodeling in Rats with Smoke Induced Chronic Obstructive Pulmonary Disease

To evaluate the effects of ambroxol hydrochloride on lung tissue cell apoptosis and vascular remodeling in rats with smoke induced chronic obstructive pulmonary disease. Sprague Dawley rats were randomly divided into normal, model, experimental and control groups (n=20). The rat model of chronic obstructive pulmonary disease was established by fumigation using Yan’an Cigarettes for 64 d. After fumigation, the experimental and control groups were subcutaneously injected with 5 mL of Ambroxol hydrochloride (20 mg/kg) and 5 mL of Bambuterol hydrochloride (20 mg/kg) respectively, while the normal and model groups were intraperitoneally injected with an equal dose of normal saline. Following drug intervention for 28 d, the pathological changes in lung tissues, vascular remodeling, lung tissue cell apoptosis, expressions of alpha-smooth muscle actin and vascular endothelial growth factor, as well as levels of caspase-3, B-cell lymphoma-2 and B-cell lymphoma-2 associated X protein were detected by hematoxylin and eosin staining, elastic Van Gieson staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, immunohistochemical staining and western blotting, respectively. Compared with normal group, the damage of lung tissues was obvious, the medial thickness of pulmonary arterioles significantly increased, the degree of vascular muscularization, apoptosis rate and expressions of alpha-smooth muscle actin, vascular endothelial growth factor, caspase-3 and B-cell lymphoma-2 associated X protein rose and the expression of B-cell lymphoma-2 decreased in model group (p<0.05). Compared with model group, the damage of lung tissues was significantly improved, the medial thickness of pulmonary arterioles decreased, the degree of vascular muscularization, apoptosis rate and expressions of alpha-smooth muscle actin, vascular endothelial growth factor, caspase-3 and B-cell lymphoma-2 associated X protein reduced and the expression of B-cell lymphoma-2 rose in experimental and control groups (p<0.05). Ambroxol hydrochloride can inhibit the apoptosis of lung tissue cells and improve vascular remodeling, thereby protecting the lung tissues of chronic obstructive pulmonary disease rats.

Long Non-coding RNA TUG1 Modulates Expression of Elastin to Relieve Bronchopulmonary Dysplasia via Sponging miR-29a-3p.

Objective: Multiple studies have highlighted that long non-coding RNAs (lncRNAs) may exert paramount roles in relieving bronchopulmonary dysplasia (BPD). The aim of our investigation is to probe the role and mechanism of lncRNA taurine upregulated gene 1 (TUG1) in BPD.Methods: The current mouse model of BPD was simulated by induction of hyperoxia, and hyperoxia-induced mouse type II alveolar epithelial (MLE-12) (MLE-12) cells were established as a cellular model. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine relative expressions of TUG1, miR-29a-3p, and elastin (ELN). We assessed cell apoptosis by TdT-mediated dUTP-biotin nick-end labeling (TUNEL) staining. Western blot was used for detection of apoptosis-related proteins. Moreover, cell viability was tested by cell counting kit-8 (CCK-8) assay. Inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA). Dual-luciferase reporter (DLR) assay was employed to confirm relationship between genes.Results: Upregulation of miR-29a-3p was found in lung tissues of BPD mice compared with lung tissues without BPD, while downregulations of TUG1 and ELN were discovered in BPD tissues in comparison with tissues without BPD. Increasing TUG1 was shown to alleviate lung injury of BPD mice and promote proliferation of hyperoxia-induced MLE-12 cells. Meanwhile, TUG1 inhibited inflammatory response and cell apoptosis in lung tissues of BPD mice and hyperoxia-induced MLE-12 cells. miR-29a-3p was targeted by TUG1 and negatively modulated by TUG1. ELN was inversely regulated by miR-29a-3p. Meantime, suppressive effects of TUG1 on apoptosis and inflammation were reversed by decreasing ELN or increasing miR-29a-3p in hyperoxia-induced MLE-12 cells.Conclusion: lncRNA TUG1 relieved BPD through regulating the miR-29a-3p/ELN axis, which provided a therapeutic option to prevent or ameliorate BPD.

Inhibition Mir-92a Alleviates Oxidative Stress and Apoptosis of Alveolar Epithelial Cells Induced by Lipopolysaccharide Exposure through TLR2/AP-1 Pathway.

Objective To probe into the role of miR-92a in alleviating oxidative stress and apoptosis of alveolar epithelial cell (AEC) injury induced by lipopolysaccharide (LPS) exposure through the Toll-like receptor (TLR) 2/activator protein-1 (AP-1) pathway. Methods Acute lung injury (ALI) rat model and ALI alveolar epithelial cell model were constructed to inhibit the expression of miR-92a/TLR2/AP-1 in rat and alveolar epithelial cells (AECs), to detect the changes of oxidative stress, inflammatory response, and cell apoptosis in rat lung tissues and AECs, and to measure the changes of wet-dry weight (W/D) ratio in rat lung tissues. Results Both inhibition of miR-92a expression and knockout of TLR2 and AP-1 gene could reduce LPS-induced rat ALI, alleviate pulmonary edema, inhibit oxidative stress and inflammatory response, and reduce apoptosis of lung tissue cells. In addition, the TLR2 and AP-1 levels in the lung tissues of ALI rats were noticed to be suppressed when inhibiting the expression of miR-92a, and the AP-1 level was also decreased after the knockout of TLR2 gene. Further, we verified this relationship in AECs and found that inhibition of miR-92a/TLR2/AP-1 also alleviated LPS-induced AEC injury, reduced cell apoptosis, and inhibited oxidative stress and inflammatory response. What is more, like that in rat lung tissue, the phenomenon also existed in AECs, that is, when the expression of miR-92a was inhibited, the expression of TLR2 and AP-1 was inhibited, and silencing TLR2 can reduce the expression level of AP-1. Conclusion MiR-92a/TLR2/AP-1 is highly expressed in ALI, and its inhibition can improve oxidative stress and inflammatory response and reduce apoptosis of AECs.

Effect of different doses of dexmedetomidine on lung function and tissue cell apoptosis in a rat model of hyperoxic acute lung injury

Purpose: To study the effect of different doses of dexmedetomidine on lung function and lung tissue cell apoptosis in a rat model of hyperoxic acute lung injury.&#x0D; Methods: Five groups of healthy male Sprague-Dawley rats were used: normal rats, untreated hyperoxic rats, and hyperoxic rats given 3 different doses of dexmedetomidine, with 20 rats in each group. The levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were determined usingenzyme-linked immunosorbent assay (ELISA). Parietal paraffin cuts were taken from the right upper lobe for measurement of apoptosis using in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and the apoptosis index was calculated.&#x0D; Results: At 24 and 48 h, the levels of IL-6 and TNF-α in the hyperoxia model group were significantly higher than those in the normal control group, and their levels in the middle- and high-dose groups were markedly lowered, relative to untreated hyperoxia rats (p &lt; 0.05). Apoptosis index in the hyperoxia model rats significantly increased, relative to normal rats (p &lt; 0.05). The apoptosis index in the mediumand high-dose groups decreased significantly (p &lt; 0.05).&#x0D; Conclusion: Dexmedetomidine inhibits inflammatory responses caused by high concentration of oxygen inhalation, minimizes lung injury, improves lung function and inhibits lung apoptosis.&#x0D; Keywords: Dexmedetomidine, Hyperoxia, Acute lung injury, Lung function, Apoptosis