Thickening Of Alveolar Septa Research Articles

Regional variations in hyperpolarized 129Xe lung MRI: Insights from CSI-CSSR and CSSR in healthy and irradiated rat models.

To compare pulmonary function metrics obtained with hyperpolarized xenon-129 (HXe) MRS, using chemical shift saturation recovery (CSSR) and CSI-CSSR, in healthy rats and a rat model of radiation-induced lung injury. HXe-MR data were acquired in two healthy rats and one rat with radiation-induced lung injury using whole-lung spectroscopy and CSI-CSSR techniques. The CSI-CSSR acquisitions were performed with both fixed TE and variable TE. Apparent alveolar septal wall thickness, gas transfer dynamics, and regional lung function were quantified and compared across acquisition methods. Spectral analysis included alignment of dissolved-phase frequency spectra using the membrane resonance as reference, segmentation of gas-phase (GP) frequency distribution, and characterization of gas uptake in the vasculature. Complex GP line shapes were observed in rat lungs, necessitating pixel-wise CSI analysis and membrane resonance alignment for improved quantification. Notable differences in alveolar septal wall thickness, dissolved-phase GP ratios, and GP and red blood cell frequencies were found between acquisition techniques and lung conditions. CSI-CSSR provided unique insights into regional lung function, including the identification of distinct GP frequency zones potentially corresponding to different airway structures, and the ability to map relative xenon gas transport. Metrics from fixed-TE and variable-TE acquisitions usually differed by less than 10%, but the latter yielded a 20% SNR gain. HXe-MRS and CSI-CSSR techniques provide similar but not universally interchangeable insights into lung function, particularly in the presence of pathology.

The triple combination DBDx alleviates cytokine storm and related lung injury

Cytokine storm is a life-threatening disorder, and therapeutic treatments are urgently needed. Here, we investigated the anti-cytokine storm efficacy of DBDx, a triple drug combination composed of dipyridamole, ubenimex and dexamethasone. Evaluated by lipopolysaccharide (LPS)-induced cytokine storm murine model, DBDx significantly improved survival rate and prolonged survival time of the model mice. Notably, the efficacy of DBDx was higher than that of dipyridamole, ubenimex and dexamethasone. Determined by ELISA, DBDx significantly reduced the LPS-stimulated serum levels of TNF-α, IL-6 and IL-1β in mice. Luminex assay showed that DBDx suppressed the serum levels of a wide variety of inflammatory cytokines and chemokines, which was more potent than dexamethasone alone. Otherwise, DBDx exerted similar inhibitory effects on cytokine profiles in bronchoalveolar lavage fluid. Histopathological observation showed that DBDx significantly reduced the LPS-induced thickening of alveolar septum, indicating its suppression of capillary congestion, edema and neutrophil infiltration in the lung. Ultra-structure analysis showed that DBDx suppressed the LPS-induced morphological changes of microvilli in type II pneumocytes. In vitro experiment showed that DBDx inhibited IL-6 and TNF-α secretion in THP-1 cells, and downregulated TLR4/NF-κB/HIF-1α signaling pathway. All of these results demonstrate that DBDx, a triple combination of clinical orally-administered drugs, can alleviate cytokine storm and related lung injury. DBDx is beneficial for treating cytokine storm disorders.

DNA-PKcs modulates mouse lung homeostasis via the regulation of mitochondrial fission

BackgroundThe role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is multifaceted, paradoxically promoting both cell survival and cell death across multiple organs. However, its impact on lung homeostasis remains elusive. Here, we investigate the function of DNA-PKcs in mouse lungs, aiming to elucidate its role for lung abnormalities associated with DNA-PKcs deficiency. Materials and methodsHistological assessment and immunohistochemistry were used to reveal the pathological changes of the lungs in DNA-PKcs-deficient mice. Transcriptomic analysis identified differentially expressed genes and pathways in DNA-PKcs-deficient lungs. Furthermore, mitochondrial dysfunction induced by DNA-PKcs deficiency was investigated by qPCR and immunoblotting. Mouse primary lung fibroblasts were used to evaluate the potential therapeutic effect of inhibiting mitochondrial fission with Mdivi-1. Key findingsIn DNA-PKcs-deficient mouse lungs, we observed pathological changes including alveolar septal thickening, capillary congestion and hemorrhage, along with lung cell proliferation. Transcriptome analysis revealed an upregulation of the reactive oxygen species (ROS) biosynthesis process and the apoptotic signaling pathway caused by DNA-PKcs deficiency. Further investigations demonstrated that DNA-PKcs deficiency led to mitochondrial dysfunction and increased oxidative stress, along with increased cell apoptosis in the mouse lungs. Notably, we detected enhanced phosphorylation of the mitochondrial fission protein DRP1 in DNA-PKcs-deficient mouse lungs. Intriguingly, inhibiting mitochondrial fission using Mdivi-1 suppressed cell death in primary mouse lung fibroblasts with siRNA-mediated DNA-PKcs knockdown. SignificanceOur study provides insights into the crucial role of DNA-PKcs in sustaining lung homeostasis via the maintenance of mitochondrial functionality and provides a therapeutic strategy targeting mitochondrial fission against DNA-PKcs deficiency-associated lung diseases.

Annexin A1 activates the G protein-coupled formyl peptide receptor type 2-dependent endothelial nitric oxide synthase pathway to alleviate sepsis associated acute lung injury

To investigate whether annexin A1 (ANXA1) improves sepsis-induced lung injury by activating G protein-coupled formyl peptide receptor type 2 (FPR2)-dependent endothelial nitric oxide synthase (eNOS) pathway. Twenty-four male SD rats were randomly divided into normal group (Control group), lipopolysaccharide (LPS) induced lung injury model group (LPS group), LPS+ANXA1 mimetic peptide group (LPS+Ac2-26 group) and LPS+ANXA1 mimetic peptide+FPR2 inhibitor group (LPS+Ac2-26+WRW4 group), with 6 rats in each group. On the third day before modeling, rats of the LPS+Ac2-26 group were injected with 1 mg/kg Ac2-26 by the tail vein and rats of LPS+Ac2-26+WRW4 group were injected with 1 mg/kg Ac2-26 and 2.2 mg/kg WRW4 by the tail vein. The rats of control group and LPS group were injected same volume of physiological saline. After 48 hours of modeling, the rats were anesthetized and the carotid blood was taken to detect the oxygenation index (OI). Lung tissue was taken from the euthanized rats. The wet/dry (W/D) ratio was determined. The pathological changes of lung tissue were observed under light microscope and pathological score was performed. The levels of tumor necrosis factor-α (TNF-α), interleukins (IL-1β, IL-6, IL-10), malondialdehyde (MDA) and myeloperoxidase (MPO) were detected by enzyme-linked immunosorbent assay (ELISA). The protein expressions of eNOS, inducible nitric oxide synthase (iNOS) and nuclear factor-κB (NF-κB) were detected by Western blotting. Under light microscope, compared with LPS group, the infiltration degree of inflammatory cells in the lung tissue of LPS+Ac2-26 group was reduced, and the thickness of the alveolar septum was improved. The degree of inflammatory cell infiltration in the lung tissue of LPS+Ac2-26+WRW4 group was more severe than that of LPS+Ac2-26 group, and the thickness of the alveolar septum increased. These findings suggested that ANXA1 significantly inhibited inflammatory cell infiltration and improved alveolar septal thickness, WRW4 reversed the lung improvement effects of ANXA1. Compared with control group, OI in LPS group was significantly decreased, and W/D ratio, pathological score and TNF-α, IL-1β, IL-6, MDA and MPO levels in lung tissue were significantly increased. Compared with LPS group, OI and IL-10 levels in lung tissue were significantly increased in LPS+Ac2-26 group, while W/D ratio, pathological score, TNF-α, IL-1β, IL-6, MDA and MPO levels in lung tissue were significantly decreased. These results indicated that ANXA1 can improve the oxygenation capacity, improve lung tissue leakage, reduce edema, and inhibit lung tissue inflammation in rats with lung injury. Compared with LPS+Ac2-26 group, the LPS+Ac2-26+WRW4 group showed significant decreases in OI and lung tissue IL-10 level [OI (mmHg, 1 mmHg ≈ 0.133 kPa): 132.16±24.00 vs. 248.67±18.70, IL-10 (ng/L): 27.30±3.04 vs. 36.10±3.92, both P < 0.05], the lung tissue W/D ratio, pathological score and levels of TNF-α, IL-1β, IL-6, MDA and MPO were significantly increased [W/D ratio: 5.29±0.02 vs. 4.83±0.02, pathological score: 5.00±0.28 vs. 2.67±0.52, TNF-α (ng/L): 39.80±4.36 vs. 32.10±2.15, IL-1β (ng/L): 200.00±15.68 vs. 152.60±9.74, IL-6 (ng/L): 181.50±18.02 vs. 148.50±7.34, MDA (mmol/mg): 82.01±8.22 vs. 70.43±5.69, MPO (pg/mg): 6.50±0.32 vs. 4.60±0.56, all P < 0.05]. These results suggested that WRW4 could block the above improvement of ANXA1. Western blotting results showed that compared with control group, the expression of eNOS, iNOS and NF-κB in LPS group was significantly up-regulated. Compared with LPS group, the protein expression of eNOS in LPS+Ac2-26 group was significantly up-regulated (eNOS/β-actin: 0.25±0.01 vs. 0.14±0.01, P < 0.05), and the protein expression of iNOS and NF-κB was significantly down-regulated (iNOS/β-actin: 0.09±0.02 vs. 0.12±0.02, NF-κB/β-actin: 0.35±0.06 vs. 0.59±0.13, both P < 0.05). These findings suggested that ANXA1 might activate the eNOS pathway and down-regulate the expression of NF-κB. Compared with LPS+Ac2-26 group, the protein expression of eNOS in LPS+Ac2-26+WRW4 group was significantly down-regulated (eNOS/β-actin: 0.17±0.02 vs. 0.25±0.01, P < 0.05), while the protein expression of iNOS and NF-κB was significantly up-regulated (iNOS/β-actin: 0.12±0.02 vs. 0.09±0.02, NF-κB/β-actin: 0.52±0.10 vs. 0.35±0.06, both P < 0.05). These results suggested that WRW4 blocked the activation of the eNOS pathway by ANXA1. ANXA1 can improve lung injury associated with sepsis by activating FPR2-dependent eNOS pathway.

Protective Effects of Carvacrol on Mercuric Chloride-Induced Lung Toxicity Through Modulating Oxidative Stress, Apoptosis, Inflammation, and Autophagy.

Mercuric chloride (HgCl2) is extremely toxic to both humans and animals. It could be absorbed via ingestion, inhalation, and skin contact. Exposure to HgCl2 can cause severe health effects, including damages to the gastrointestinal, respiratory, and central nervous systems. The purpose of this work was to explore if carvacrol (CRV) could protect rats lungs from damage caused by HgCl2. Intraperitoneal injections of HgCl2 at a dose of 1.23 mg/kg body weight were given either alone or in conjunction with oral CRV administration at doses of 25 and 50 mg/kg body weight for 7 days. The study included biochemical and histological techniques to examine the lung tissue's oxidative stress, apoptosis, inflammation, and autophagy processes. HgCl2-induced reductions in GSH levels and antioxidant enzymes (SOD, CAT, and GPx) activity were enhanced by CRV co-administration. Furthermore, MDA levels were lowered by CRV. The inflammatory mediators NF-κB, IκB, NLRP3, TNF-α, IL-1β, IL6, COX-2, and iNOS were all reduced by CRV. When exposed to HgCl2, the levels of apoptotic Bax, caspase-3, Apaf1, p53, caspase-6, and caspase-9 increased, but the levels of antiapoptotic Bcl-2 reduced after CRV treatment. CRV decreased levels of Beclin-1, LC3A, and LC3B, which in turn decreased HgCl2-induced autophagy damage. After HgCl2 treatment, higher pathological damage was observed in terms of alveolar septal thickening, congestion, edema, and inflammatory cell infiltration compared to the control group while CRV ameliorated these effects. Consequently, by preventing HgCl2-induced increases in oxidative stress and the corresponding inflammation, autophagy, apoptosis, and disturbance of tissue integrity in lung tissues, CRV might be seen as a useful therapeutic alternative.

Mitigation of Oxidative Stress in Idiopathic Pulmonary Fibrosis Through Exosome-Mediated Therapies.

Idiopathic pulmonary fibrosis (IPF) poses a formidable clinical challenge, characterized by the thickening of alveolar septa and the onset of pulmonary fibrosis. The pronounced activation of oxidative stress emerges as a pivotal hallmark of inflammation. Traditional application of exogenous antioxidants proves inadequate in addressing oxidative stress, necessitating exploration into strategies to augment their antioxidant efficacy. Exosomes, nano-sized extracellular vesicles harboring a diverse array of bioactive factors, present as promising carriers with the potential to meet this challenge. Recent attention has been directed towards the clinical applications of exosomes in IPF, fueling the impetus for this comprehensive review. We have compiled fresh insights into the role of exosomes in modulating oxidative stress in IPF and delved into their potential as carriers for regulating endogenous reactive oxygen species generation. This review endeavors to bridge the divide between exosome research and IPF, traversing from bedside to bench. Through the synthesis of recent findings, we propose exosomes as a novel and promising strategy for improving the outcomes of IPF therapy.

Hyperoxia-Induced miR-195 Causes Bronchopulmonary Dysplasia in Neonatal Mice.

Background: Exposure to hyperoxia is an important factor in the development of bronchopulmonary dysplasia (BPD) in preterm newborns. MicroRNAs (miRs) have been implicated in the pathogenesis of BPD and provide a potential therapeutic target. Methods: This study was conducted utilizing a postnatal animal model of experimental hyperoxia-induced murine BPD to investigate the expression and function of miR-195 as well as its molecular signaling targets within developing mouse lung tissue. Results: miR-195 expression levels increased in response to hyperoxia in male and female lungs, with the most significant elevation occurring in 40% O2 (mild) and 60% O2 (moderate) BPD. The inhibition of miR-195 improved pulmonary morphology in the hyperoxia-induced BPD model in male and female mice with females showing more resistance to injury and better recovery of alveolar chord length, septal thickness, and radial alveolar count. Additionally, we reveal miR-195-dependent signaling pathways involved in BPD and identify PH domain leucine-rich repeat protein phosphatase 2 (PHLPP2) as a novel specific target protein of miR-195. Conclusions: Our data demonstrate that high levels of miR-195 in neonatal lungs cause the exacerbation of hyperoxia-induced experimental BPD while its inhibition results in amelioration. This finding suggests a therapeutic potential of miR-195 inhibition in preventing BPD.

Mechanism of total glucosides of White Paeony Capsules in ameliorating acute lung injury based on NLRP3 inflammasome

This study deciphered the ameliorating effect and molecular mechanism of the total glucosides of White Paeony Capsules(TGP) in the treatment of mice model with acute lung injury(ALI) via NOD-like receptor thermal protein domain associated protein 3(NLRP3) signaling pathway of the inflammasome. The study established an inflammasome activation model of primed bone marrow-derived macrophages(BMDMs), and its molecular mechanism was investigated by Western blot(WB), immunofluorescence staining, enzyme-linked immunosorbent assay(ELISA), and flow cytometry. C57BL/6J mice were randomly divided into a blank control group, a TGP group, a model group(LPS group), LPS+low-and high-dose TGP groups, LPS+MCC950 group, and LPS+MCC950+TGP group, with eight mice per group. The ALI model was induced in mice. Finally, bronchoalveolar lavage fluid(BALF) and lung tissue were collected. Lung index and lung weight wet-to-dry ratio were determined for each group of mice. The pathological changes in lung tissue were observed through hematoxylin-eosin(HE) staining. The number of neutrophils in the BALF of each group was detected using flow cytometry. The levels of interleukin(IL)-1β, IL-6, and tumor necrosis factor(TNF)-α in the BALF were determined by ELISA. The expressions of IL-1β, IL-18, IL-6, and TNF-α in the lung tissue were determined by real-time quantitative PCR(RT-qPCR). This study demonstrated that TGP dramatically blocked the activation of the NLRP3 inflammasome by inhibiting the production of upstream mitochondrial reactive oxygen species(mtROS) and the subsequent oligomerization of apoptosis-associated specks(ASC). Additionally, in the ALI mice model, compared with the blank control group, the model group showed alveolar structure rupture, thic-kening of alveolar septa, and dramatically increased lung index, lung weight wet-to-dry ratio in lung tissue, neutrophil count, and inflammatory factor levels. Compared with the model group, the pathological morphology of lung tissue was significantly ameliorated in the TGP and MCC950 groups, and the lung index and lung weight wet-to-dry ratio were significantly reduced. Neutrophil counts were reduced, and levels of inflammatory factors were significantly downregulated. Notably, compared with the MCC950 group, there was no significant difference in effect in the MCC950+TGP group. Collectively, the study reveals that TGP may ameliorate ALI in mice by inhibiting the activation of NLRP3 inflammasome, providing a safe and effective drug candidate for the prevention or treatment of ALI/ARDS.

Syringic acid attenuates acute lung injury by modulating macrophage polarization in LPS-induced mice

BackgroundAcute lung injury (ALI) is a continuum of lung changes caused by multiple lung injuries, characterized by a syndrome of uncontrolled systemic inflammation that often leads to significant morbidity and death. Anti-inflammatory is one of its treatment methods, but there is no safe and available drug therapy. Syringic acid (SA) is a natural organic compound commonly found in a variety of plants, especially in certain woody plants and fruits. In modern pharmacological studies, SA has anti-inflammatory effects and therefore may be a potentially safe and available compound for the treatment of acute lung injury. PurposeThis study attempts to reveal the protective mechanism of SA against ALI by affecting the polarization of macrophages and the activation of NF-κB signaling pathway. Trying to find a safer and more effective drug therapy for clinical use. MethodsWe constructed the ALI model using C57BL/6 mice by intratracheal instillation of LPS (10 mg/kg). Histological analysis was performed with hematoxylin and eosin (H&E). The wet-dry ratio of the whole lung was measured to evaluate pulmonary edema. The effect of SA on macrophage M1-type was detected by flow cytometry. BCA protein quantification method was used to determine the total protein concentration in bronchoalveolar lavage fluid (BALF). The levels of Interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in BALF were determined by the ELISA kits, and RT-qPCR was used to detect the expression levels of IL-6, IL-1β and TNF-α mRNA of lung tissue. Western blot was used to detect the expression levels of iNOS and COX-2 and the phosphorylation of p65 and IκBα in the NF-κB pathway in lung tissue. In vitro experiments were conducted with RAW267.4 cell inflammation model induced by 100 ng/ml LPS and A549 cell inflammation model induced by 10 μg/ml LPS. The effects of SA on M1-type and M2-type macrophages of RAW267.4 macrophages induced by LPS were detected by flow cytometry. The toxicity of compound SA to A549 cells was detected by MTT method which to determine the safe dose of SA. The expressions of COX-2 and the phosphorylation of p65 and IκBα protein in NF-κB pathway were detected by Western blot. ResultsWe found that the pre-treatment of SA significantly reduced the degree of lung injury, and the infiltration of neutrophils in the lung interstitium and alveolar space of the lung. The formation of transparent membrane in lung tissue and thickening of alveolar septum were significantly reduced compared with the model group, and the wet-dry ratio of the lung was also reduced. ELISA and RT-qPCR results showed that SA could significantly inhibit the production of IL-6, IL-1β, TNF-α. At the same time, SA could significantly inhibit the expression of iNOS and COX-2 proteins, and could inhibit the phosphorylation of p65 and IκBα proteins. in a dose-dependent manner. In vitro experiments, we found that flow cytometry showed that SA could significantly inhibit the polarization of macrophages from M0 type macrophages to M1-type macrophages, while SA could promote the polarization of M1-type macrophages to M2-type macrophages. The results of MTT assay showed that SA had no obvious cytotoxicity to A549 cells when the concentration was not higher than 80 μM, while LPS could promote the proliferation of A549 cells. In the study of anti-inflammatory effect, SA can significantly inhibit the expression of COX-2 and the phosphorylation of p65 and IκBα proteins in LPS-induced A549 cells. ConclusionSA has possessed a crucial anti-ALI role in LPS-induced mice. The mechanism was elucidated, suggesting that the inhibition of macrophage polarization to M1-type and the promotion of macrophage polarization to M2-type, as well as the inhibition of NF-κB pathway by SA may be the reasons for its anti-ALI. This finding provides important molecular evidence for the further application of SA in the clinical treatment of ALI.

Exploring Mycoplasma ovipneumoniae NXNK2203 infection in sheep: insights from histopathology and whole genome sequencing

BackgroundMycoplasma ovipneumoniae (M. ovipneumoniae) is a significant pathogen causing respiratory infections in goats and sheep. This study focuses on investigating vulnerability of Hu sheep to M. ovipneumoniae infection in the context of late spring’s cold weather conditions through detailed autopsy of a severely affected Hu sheep and whole genome sequencing of M. ovipneumoniae.ResultsThe autopsy findings of the deceased sheep revealed severe pulmonary damage with concentrated tracheal and lung lesions. Histopathological analysis showed tissue degeneration, mucus accumulation, alveolar septum thickening, and cellular necrosis. Immunohistochemistry analysis indicated that M. ovipneumoniae was more in the bronchi compared to the trachea. Genome analysis of M. ovipneumoniae identified a 1,014,835 bp with 686 coding sequences, 3 rRNAs, 30 tRNAs, 6 CRISPRs, 11 genomic islands, 4 prophages, 73 virulence factors, and 20 secreted proteins.ConclusionThis study investigates the vulnerability of Hu sheep to M. ovipneumoniae infection during late spring’s cold weather conditions. Autopsy findings showed severe pulmonary injury in affected sheep, and whole genome sequencing identified genetic elements associated with pathogenicity and virulence factors of M. ovipneumoniae.

Exposure to tobacco (Nicotiana tabacum) extract and cigarette smoke induces hematological and histopathological alterations in Swiss albino mice

Tobacco smoking is a widely practiced recreational activity and is associated with numerous health risks. Hence, the present study was conducted on Swiss albino mice to assess the impact of aqueous extract of tobacco and cigarette smoke on behavioral, hematological, and histopathological parameters of the lungs, liver, and kidney. The mice were divided into Control (Cont), Tobacco nicotiana (TN), and Cigarette smoke (CS) groups (n=6). TN group received aqueous tobacco orally at a dose of 5ml/kg BW for 21 days, whereas CS group was exposed to inhalational commercial cigarette smoke for the same duration. On day 22, blood samples and visceral organs were collected to evaluate hematological (TEC, TLC, Hb%) and histopathological parameters from euthanized mice. The TEC values were significantly elevated (P&lt;0.05) in both groups. In contrast to the control group, the TLC value was lower in the CS group (P&gt;0.05) than in the TN group, but the mean Hb% values showed no significant changes. Lower body weight, aggressive behavior, and weakness were observed in the treated groups. Histopathologically, the lung revealed emphysematous changes, alveolar septal thickening, inflammatory cells infiltration, congestion, and thrombus formation in pulmonary artery. Liver exhibited hepatocyte degeneration with karyomegaly and karyorrhexis, derangement of hepatic cords and sinusoids with central vein congestion. Derangement of renal tubules, edema, and glomerular degeneration observed in the kidney. These observations lead us to postulate that tobacco and cigarette smoke exert detrimental effects on the structure of some vital organs in the body after direct or indirect uptake.

Exploring Lung Histopathology in White Rats After Cigarette Smoke Exposure

Smoking-induced respiratory epithelium changes, driven by nicotine and smoke components, can lead to severe lung alterations with prolonged exposure. However, until now, no one has examined the histopathological appearance of bronchioles and alveoli in Wistar rats following exposure to cigarette smoke. This study aimed to assessed lung histopathological changes in white rats (Rattus norvegicus) exposed to cigarette smoke. A descriptive study used a post-test group control design, exposing Rattus norvegicus to cigarette smoke and dividing them into control, 1-week, 2-week, and 4-week groups. Histopathological findings revealed that the control group had intact bronchioles; the one-week group showed lymphocyte infiltration and typical alveolar structure; the two-week group had increased respiratory epithelial cells; the four-week group displayed dominant bronchiole changes; the one-week group had varying alveolar septal thickness; the two-week group had narrowed alveolar lumens; four-week group showed thickened septa and pronounced pigmented macrophages. Cigarette smoke exposure affects changes to Rattus norvegicus lung histology. Prolonged exposure to cigarette smoke induces damage to the structure of the bronchioles and alveoli.

Spleen contributes to chronic restraint stress-induced lung injury through splenic CD11b+ cells

Chronic stress can induce lung injury. The spleen, as the largest peripheral immune organ, plays a crucial role in various lung diseases. Our previous study found that the spleen underwent significant changes during chronic restraint stress (CRS). However, the exact role of the spleen in CRS-induced lung injury remains unclear. In this study, we found that CRS could increase lung index. CRS could lead to alterations of the lungs such as destruction of alveolar wall, thickening of alveolar septa, dilation of pulmonary capillaries, and increased inflammatory cell infiltration. CRS increases the concentration of malondialdehyde (MDA), decreases the level of surfactant protein A (SP-A), and elevates the levels of pro-inflammatory factors (TNF-α, IL-6, and IL-1β) in the lungs. Additionally, CRS could increase the proportions and numbers of CD11b+Ly6ChiLy6G- monocytes in the lung, while cannot alter proportions and numbers of CD3-NK1.1+ NK cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and CD11b+Ly6G+ neutrophils. Moreover, the levels of inflammatory markers in lung tissues were positively correlated with the proportion of CD11b+Ly6ChiLy6G- monocytes. Interestingly, splenectomy inhibited CRS-induced lung injury and attenuated the alteration in the proportion of CD11b+Ly6ChiLy6G- monocytes in the lungs induced by CRS. Moreover, splenic CD11b+ cells, rather than splenic CD11b- cells, transfused into splenectomized mice, and subsequently exposed to CRS, can cause lung injury. These results suggest that CRS could induce lung injury and CD11b+Ly6ChiLy6G- monocytes aggregation in the lung. The spleen could contribute to CRS-induced lung injury. Furthermore, splenic CD11b+ cells might play an important role in CRS-induced lung injury.

Caspase-3/GSDME dependent pyroptosis contributes to offspring lung injury induced by gestational PFOS exposure via PERK/ATF4 signaling.

Perfluorooctane sulfonate (PFOS) is widely used in industry and consumer products. Previous studies have showed that PFOS gestational exposure is associated with offspring lung damage in rat. However, the underlying mechanisms remain poorly understood. In this study, we investigated the role of gasdermin E (GSDME) in lung injury of offspring and its underlying mechanisms using in vivo and in vitro approaches. Pregnant SD rats were exposed to PFOS (1mg/kg BW/d) between gestational day 12-18, and the lung tissue of the offspring was evaluated on postnatal day 7. PFOS treated animals exhibited alveolar septal thickening and inflammation-related damages, with an increased expression of GSDME in alveolar type II epithelial cells (AECII). Furthermore, in vitro experiments demonstrated that PFOS exposure (with 225μM and up) upregulated the caspase-3/GSDME signaling pathway in AECII. Also, ultrastructure analysis revealed significant changes in the endoplasmic reticulum (ER) structure in PFOS-induced pyroptotic cells, which is consistent with the ER stress detected in these cells. Additionally, PFOS exposure led to increased expression of ER stress-related proteins, including p-PERK, p-eIF2α, ATF4, and CHOP. Subsequently, using specific inhibitors, we found that the PERK/ATF4 pathway acted as an upstream signal regulating GSDME-dependent pyroptosis. Overall, our findings show that GSDME-dependent pyroptosis plays a crucial role in the lung injury induced by gestational PFOS exposure, and the PERK/ATF4 pathway may function as a possible mediator of this process.

LPA2 Alleviates Septic Acute Lung Injury via Protective Endothelial Barrier Function Through Activation of PLC-PKC-FAK.

Increased endothelial permeability of pulmonary vessels is a primary pathological characteristic of septic acute lung injury (ALI). Previously, elevated lysophosphatidic acid (LPA) levels and LPA2 (an LPA receptor) expression have been found in the peripheral blood and lungs of septic mice, respectively. However, the specific role of LPA2 in septic ALI remains unclear. A lipopolysaccharide (LPS)-induced model of sepsis was established in wild-type (WT) and global LPA2 knockout (Lpar2-/-) mice. We examined mortality, lung injury, assessed endothelial permeability through Evans blue dye (EBD) assay in vivo, and transendothelial electrical resistance (TEER) of mouse lung microvascular endothelial cells (MLMECs) in vitro. Enzyme-linked immunosorbent assay (ELISA), histopathological, immunofluorescence, immunohistochemistry, and Western blot were employed to investigate the role of LPA2 in septic ALI. Lpar2 deficiency increased vascular endothelial permeability, impaired lung injury, and increased mortality. Histological examination revealed aggravated inflammation, edema, hemorrhage and alveolar septal thickening in the lungs of septic Lpar2-/- mice. In vitro, loss of Lpar2 resulted in increased permeability of MLMECs. Pharmacological activation of LPA2 by the agonist DBIBB led to significantly reduced inflammation, edema and hemorrhage, as well as increased expression of the vascular endothelial tight junction (TJ) protein zonula occludens-1 (ZO-1) and claudin-5, as well as the adheren junction (AJ) protein VE-cadherin. Moreover, DBIBB treatment was found to alleviate mortality by protecting against vascular endothelial permeability. Mechanistically, we demonstrated that vascular endothelial permeability was alleviated through LPA-LPA2 signaling via the PLC-PKC-FAK pathway. These data provide a novel mechanism of endothelial barrier protection via PLC-PKC-FAK pathway and suggest that LPA2 may contribute to the therapeutic effects of septic ALI.

Hepatocyte Growth Factor Delivered by Nanocomposites for Gene Therapy of Bleomycin-Induced Pulmonary Fibrosis in Rats.

Pulmonary fibrosis (PF) is a chronic and progressive interstitial lung disease. There is no effective treatment for PF. Hepatocyte growth factor (HGF) has anti-inflammatory and antifibrotic effects but has limited potential owing to its short half-life. To increase the transfection efficiency of pVAX-HGF, we prepared polyethyleneiminepolyethylene glycol: polyethyleneimine/pVAX-HGF (PEG-PEI: PEI/pVAX-HGF) nanocomposite loaded with a plasmid encoding the HGF gene. The PEG-PEI:PEI/pVAX-HGF characteristics, including morphology, particle size, zeta-potential, and DNA entrapment efficiency, were investigated. The pVAX-HGF nanocomposites with low toxicity and high transfection efficiency were screened by cell viability assay and cell transfection. The antifibrotic effect of pVAX-HGF nanocomposite on PF rats induced by bleomycin (BLM) was evaluated by pulmonary function measurement, pathological examination and collagen content assay. Different nanocomposites were prepared to deliver pVAX-HGF, in which mix1 (PEGPEI: PEI/pVAX-HGF) has lower potential and better entrapment ability. PEI/pVAX-HGF (N/P=25) nanocomposite with low toxicity and high transfection efficiency was administered to PF rats. After treatment with mix 1/pVAX-HGF, the index of lung function(including EF50, MV, TV, PEF and PIF) in mix 1/pVAX-HGF group was higher than that of the PF group. The number of cells in BALF of the mix 1/pVAX-HGF group was significantly lower than that of the PF groups, and the content of hydroxyproline(HYP) and collagen Type I (Col-I) in the lung of the mix 1/pVAX-HGF group was much lower than that of the PF groups in the early stage. The result of pathological examination showed that rats in the mix1/pVAX-HGF group showed obviously reduced alveolar septal thickening, fewer infiltrated inflammatory cells and less collagen deposition. The PEG-PEI:PEI/pVAX-HGF nanocomposite can ameliorate PF induced by BLM. The pVAX-HGF nanocomposite is a latent therapeutic strategy for PF.

Effect of Folic Acid in Sepsis-induced Lung Damage in Rats

Aim: Sepsis-induced lung injury remains a critical concern with significant morbidity and mortality. This study aimed to investigate the potential therapeutic role of Folic Acid in mitigating lung injury induced by sepsis while exploring its interaction with the soluble suppression of tumorigenicity 2 (sST2) protein in an experimental rat model. &#x0D; Material and Methods: Rats were divided into three groups: a normal control group, a group induced with sepsis and treated with saline, and a group induced with sepsis and treated with Folic Acid (5 mg/kg). Biomarkers of oxidative stress, inflammation, respiratory gas exchange, and lung histopathology were assessed. &#x0D; Results: Folic Acid administration resulted in significantly decreased Malondialdehyde (MDA) levels (p

Arsenic exposure and lung fibrotic changes-evidence from a longitudinal cohort study and experimental models.

Arsenic (As) exposure is associated with lung toxicity and we aim to investigate the effects of arsenic exposure on lung fibrotic changes. Participants (n= 976) enrolled via a general health survey underwent chest low-dose computed tomography (LDCT), spirometry forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and urinary arsenic examination during 2016 and 2018. Lung fibrotic changes from LDCT were defined. AsLtoL, low arsenic levels in both 2016 and 2018; AsLtoH, low arsenic in 2016 but high levels in 2018; AsHtoL, high arsenic in 2016 but low levels in 2018; AsHtoH, high arsenic levels in both 2016 and 2018. Mice exposed to 0. 0.2mg/L, 2 mg/L, 50 mg/L of sodium arsenite (NaAsO2) through drinking water for 12 weeks and 24 weeks were applied for histological analysis. Cultured lung epithelial cells were exposed to NaAsO2 and the mesenchymal changes were examined. AsHtoH increased the risk (OR= 1.65, 95% CI 1.10, 2.49) of Lung fibrotic positive to positive (reference: Lung fibrotic negative to negative) compared with AsLtoL. Moreover, the predicted mean of FVC and FEV1 in AsHtoH (-0.09 units, 95% CI: -0.27, -0.09; -0.09 units, 95% CI: -0.17, -0.01) and AsLtoH (-0.13 units, 95% CI: -0.30, -0.10; -0.13 units, 95% CI: -0.22, -0.04) was significantly lower than ASLtoL. Significant lung fibrotic changes including the increase of the alveolar septum thickness and collagen fiber deposition were observed upon 2 mg/L NaAsO2 treatment for 12 weeks, and the damage was dose- and time-dependent. In vitro, sodium arsenite treatment promotes the epithelial-mesenchymal transition (EMT)-like changes of the normal human bronchial epithelial cells, including upregulation of several fibrotic and mesenchymal markers (fibronectin, MMP-2, and Snail) and cell migration. Inhibition of reactive oxygen species (ROS) and MMP-2 impaired the arsenic-induced EMT changes. Administration of a flavonoid, apigenin, inhibited EMT in vitro and pulmonary damages in vivo with the reduction of mesenchymal markers. we demonstrated that continued exposure to arsenic causes lung fibrosis in humans and mice. Targeting lung epithelial cells EMT is effective on the development of therapeutic strategy. Apigenin is effective in the inhibition of arsenic-induced pulmonary fibrosis and EMT.

Betulin-rich hydroalcoholic extract of Daphne oleoides attenuates bleomycin-induced pulmonary fibrosis in rat

Background and objectivePulmonary fibrosis (PF) is a chronic and progressive respiratory disease representing the final stage of lung inflammatory disorders. Reactive oxygen species (ROS), an essential factor in the formation and progression of pulmonary fibrosis, are a significant adverse effect of Bleomycin (BLM). Antioxidant activities have been found in Daphne oleoides. In this study, we attempted to explore the function of hydroalcoholic extract of Daphne oleoides (D. oleoides) and Betulin in inhibiting bleomycin (BLM)-induced pulmonary fibrosis in rat". Materials and methodsThe current experimental study used 36 male Wistar rats (180–220). Following a random process, the animals were divided into six groups six (n = 6). Group, I (the control group) received normal saline, while Group II (the hazardous group) received intratracheal BLM (7.5 units per kg). Following the administration of BLM, Groups V and VI received daily doses of vitamin E (500 mg/kg/d, p.o.) and Betulin (10 mg kg/d, p.o.), whereas Groups III and IV received daily doses of Daphne oleoides extract (300 and 600 mg/kg/d, p.o.). Then, blood samples from the hearts of the animals were taken to assess the plasma concentrations of nitric oxide (NO) and malondialdehyde (MDA). Finally, the rats were euthanized, and the lung tissues were taken out for histological analysis and assessments of the levels of lung hydroxyproline (HP), ferric-reducing ability (FRAP), NO, Glutathione Concentration (GSH), thiol content (tSH) and MDA. FindingsElevated lung index, lung hydroxyproline, NO, and MDA plasma levels, and a reduction in total body thiol content (tSH) in the group receiving BLM were evidence of pulmonary toxicity. Treatment with D. oleoides extracts, Betulin, and Vit E, especially at 600 mg/kg, led to a marked reduction in the above parameters compared with the BLM-received group (p < 0.01). Histological Analysis of the BLM-treated group showed a considerable Lung injury with interstitial infiltration, collapsed alveolar spaces, and alveolar septal thickening. These changes were mitigated with D. oleoides 600, Betulin-, and vitamin E. These changes were mitigated with D. oleoides 600, Betulin-, and vitamin E. ConclusionThese findings suggest that D. oleoides and Betulin prevent bleomycin-induced lung fibrosis in rats by decreasing inflammatory and antioxidant markers. Daphne oleoides, therefore, have the potential to be used therapeutically to treat pulmonary fibrosis.

Ophiopogonin A attenuates acute lung inflammation in Klebsiella pneumonia mice by regulating RELA (v-rel reticuloendotheliosis viral oncogene homolog A (avian))

Ophiopogonin are natural products from the roots of Ophiopogon japonicas with various pharmacological activities. This study explored the mechanism of ophiopogonin A to alleviate the acute inflammation of the lungs of Klebsiella pneumonia. 64 rats were equally assigned into blank control group, injury model group (intratracheal injection of Klebsiella pneumonia to establish Klebsiella pneumonia model), Ophiopogonin A group and Ophiopogonin A+RELA group (combined group, on the basis of injury model group, received RELA mediated ophiopogonin A), with the dose of 10 mg/kg. The histopathological damage was observed under the microscope after HE staining, as well as inflammatory cells in bronchoalveolar lavage fluid (BALF), cytokine levels, and expression of RELA. After HE staining, compared with injury model group, bronchial epithelium structure in Ophiopogonin A group and combination group were relatively intact, the degree of infiltration of inflammatory cells was reduced, and the thickness of alveolar septum was reduced, especially in combination group. The pathological scores of Ophiopogonin A group and combination group were significantly lower, with a further lower score in combination group. The number of inflammatory cells in BALF of rats in Ophiopogonin A group and combination group were significantly reduced, especially in combination group. Similarly, cytokine levels in BALF supernatant and serum of rats in treatment group were reduced, especially in combination group (P &lt; 0.05). Ophiopogonin A could down-regulate RELA, which was further reduced in combination group. In conclusion, ophiopogonin A can reduce the invasion and pathological damage of pathogens to lung tissue and exert an anti-inflammatory ability.