Kegan Liyan oral liquid ameliorates lipopolysaccharide-induced acute lung injury through inhibition of TLR4-mediated NF-κB signaling pathway and MMP-9 expression

Targeting ferroptosis using Chinese herbal compounds to treat respiratory diseases

BACKGROUND

Respiratory diseases pose a grave threat to human life. Therefore, understanding their pathogenesis and therapeutic strategy is important. Ferroptosis is a novel type of iron-dependent programmed cell death, distinct from apoptosis, necroptosis, and autophagy, characterised by iron, reactive oxygen species, and lipid peroxide accumulation, as well as glutathione (GSH) depletion and GSH peroxidase 4 (GPX4) inactivation. A close association between ferroptosis and the onset and progression of respiratory diseases, including chronic obstructive pulmonary disease, acute lung injury, bronchial asthma, pulmonary fibrosis, and lung cancer, has been reported. Recent studies have shown that traditional Chinese medicine (TCM) compounds exhibit unique advantages in the treatment of respiratory diseases owing to their natural properties and potential efficacy. These compounds can effectively regulate ferroptosis by modulating several key signalling pathways such as system Xc- -GSH-GPX4, NCOA4-mediated ferritinophagy, Nrf2-GPX4, and Nrf2/HO-1, thus playing a positive role in improving respiratory diseases.

PURPOSE

This comprehensive review systematically outlines the regulatory role of ferroptosis in the onset and progression of respiratory diseases and provides evidence for treating respiratory diseases by targeting ferroptosis with TCM compounds. These insights aim to offer potential remedies for the clinical prevention and treatment of respiratory diseases.

STUDY DESIGN AND METHODS

We searched scientific databases PubMed, Web of Science, Scopus, and CNKI using keywords such as "ferroptosis","respiratory diseases","chronic obstructive pulmonary disease","bronchial asthma","acute lung injury","pulmonary fibrosis","lung cancer","traditional Chinese medicine","traditional Chinese medicine compound","monomer", and "natural product" to retrieve studies on the therapeutic potential of TCM compounds in ameliorating respiratory diseases by targeting ferroptosis. The retrieved data followed PRISMA criteria (preferred reporting items for systematic review).

RESULTS

TCM compounds possess unique advantages in treating respiratory diseases, stemming from their natural origins and proven clinical effectiveness. TCM compounds can exert therapeutic effects on respiratory diseases by regulating ferroptosis, which mainly involves modulation of pathways such as system Xc- -GSH-GPX4,NCOA4-mediated ferritinophagy, Nrf2-GPX4, and Nrf2/HO-1.

CONCLUSION

TCM compounds have demonstrated promising potential in improving respiratory diseases through the regulation of ferroptosis. The identification of specific TCM-related inducers and inhibitors of ferroptosis holds great significance in developing more effective strategies. However, current research remains confined to animal and cellular studies, emphasizing the imperative for further verifications through high-quality clinical data.

Pharmacological effects of baicalin in lung diseases

The flavonoids baicalin and baicalein were discovered in the root of Scutellaria baicalensis Georgi and are primarily used in traditional Chinese medicine, herbal supplements and healthcare. Recently, accumulated investigations have demonstrated the therapeutic benefits of baicalin in treating various lung diseases due to its antioxidant, anti-inflammatory, immunomodulatory, antiapoptotic, anticancer, and antiviral effects. In this review, the PubMed database and ClinicalTrials website were searched with the search string "baicalin" and "lung" for articles published between September 1970 and March 2023. We summarized the therapeutic role that baicalin plays in a variety of lung diseases, such as chronic obstructive pulmonary disease, asthma, pulmonary fibrosis, pulmonary hypertension, pulmonary infections, acute lung injury/acute respiratory distress syndrome, and lung cancer. We also discussed the underlying mechanisms of baicalin targeting in these lung diseases.

Xueshuantong injection alleviates cerebral microcirculation disorder in middle cerebral artery occlusion/reperfusion rats by suppressing inflammation via JNK mediated JAK2/STAT3 and NF-κB signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

In the long history of traditional Chinese medicine, Panax notoginseng has been used as a key herb for the treatment of blood diseases. Brain microvessels support adequate blood circulation to maintain normal physiological function, therefore, brain microcirculation disorder is an important therapeutic target for various brain diseases. However, the role of Xueshuantong (XST) injection composed of saponins from P. Notoginseng (PNS) in the amelioration of cerebral microcirculation disorder is unclear.

AIMS OF THE STUDY

Cerebral microcirculation disorder and inflammation play a vital role in stroke. Capillary endothelial cells and adjacent tight junctions are fundamental to the structure and function of cerebrovascule. XST injection has been used clinically in the treatment of stroke, but no studies have reported its indication in cerebral microcirculation disorder. This study is to explore the action and mechanism of XST injection in the alleviation of cerebral microcirculation disorder in middle cerebral artery occlusion/reperfusion (MCAO/R) rats.

MATERIALS AND METHODS

MCAO/R rats and LPS-induced bEnd.3 cells were employed for the investigation of effect and mechanism of XST injection. Brain damages were evaluated by neurobehavioral assessment, 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, hematoxylin and eosin staining (H&E), and Nissl staining. Morphology and density changes of cerebral microvessels were monitored by immunohistochemistry. Cell permeability was detected by measurement of trans-endothelial electrical resistance (TEER) and sodium fluorescein (NaF) leakage. The mRNA and protein expressions of inflammatory cytokines, tight junction proteins, adhesion molecules, Janus kinase 2 (JAK2), signal transducer and activator of transcription-3 (STAT3), inhibitor of NF-κB (IκB), nuclear factor-κB (NF-κB) and c-jun N-terminal kinase (JNK) in brain microvessels and lipopolysaccharide (LPS)-induced bEnd.3 cells were measured by real-time PCR and Western blot, respectively.

RESULTS

XST injection at 48 mg/kg significantly improved the neurological damage, inflammatory infiltration, and microvessel morphology, and increased microvessel density in brain of MCAO/R rats. The endothelial permeability was significantly mitigated by XST injection in LPS-induced bEnd.3 cells. Meanwhile, the tight junction proteins such as zona occludens 1 (ZO-1) and occludin were elevated remarkably in brain microvessel of MCAO/R rats and LPS-induced bEnd.3 cells. Moreover, the expression of inflammatory mediators including interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), cycloocygenases 2 (COX-2), vascular cellular adhesion molecule-1 (VCAM-1), matrix metalloproteinase (MMP)-2, and MMP-9 were inhibited by XST injection. In addition, XST injection suppressed the phosphorylation of JAK2, STAT3, IκB, NF-κB and JNK, which could be abolished by anisomycin, the JNK agonist.

CONCLUSION

XST injection improved cerebral microvescular structure damage and dysfunction in MCAO/R rats through inhibiting inflammation activated by JNK mediated JAK2/STAT3 and NF-κB signaling pathways. The novel findings may provide theoretical basis for the clinical application in the treatment of cerebral microcirculation disorder.

The Mechanism of Lung and Intestinal Injury in Acute Pancreatitis: A Review

Acute pancreatitis (AP), as a common cause of clinical acute abdomen, often leads to multi-organ damage. In the process of severe AP, the lungs and intestines are the most easily affected organs aside the pancreas. These organ damages occur in succession. Notably, lung and intestinal injuries are closely linked. Damage to ML, which transports immune cells, intestinal fluid, chyle, and toxic components (including toxins, trypsin, and activated cytokines to the systemic circulation in AP) may be connected to AP. This process can lead to the pathological changes of hyperosmotic edema of the lung, an increase in alveolar fluid level, destruction of the intestinal mucosal structure, and impairment of intestinal mucosal permeability. The underlying mechanisms of the correlation between lung and intestinal injuries are inflammatory response, oxidative stress, and endocrine hormone secretion disorders. The main signaling pathways of lung and intestinal injuries are TNF-α, HMGB1-mediated inflammation amplification effect of NF-κB signal pathway, Nrf2/ARE oxidative stress response signaling pathway, and IL-6-mediated JAK2/STAT3 signaling pathway. These pathways exert anti-inflammatory response and anti-oxidative stress, inhibit cell proliferation, and promote apoptosis. The interaction is consistent with the traditional Chinese medicine theory of the lung being connected with the large intestine (fei yu da chang xiang biao li in Chinese). This review sought to explore intersecting mechanisms of lung and intestinal injuries in AP to develop new treatment strategies.

More Prominent Inflammatory Response to Pachyman than to Whole-Glucan Particle and Oat-β-Glucans in Dextran Sulfate-Induced Mucositis Mice and Mouse Injection through Proinflammatory Macrophages

(1→3)-β-D-glucans (BG) (the glucose polymers) are recognized as pathogen motifs, and different forms of BGs are reported to have various effects. Here, different BGs, including Pachyman (BG with very few (1→6)-linkages), whole-glucan particles (BG with many (1→6)-glycosidic bonds), and Oat-BG (BG with (1→4)-linkages), were tested. In comparison with dextran sulfate solution (DSS) alone in mice, DSS with each of these BGs did not alter the weight loss, stool consistency, colon injury (histology and cytokines), endotoxemia, serum BG, and fecal microbiome but Pachyman-DSS-treated mice demonstrated the highest serum cytokine elicitation (TNF-α and IL-6). Likewise, a tail vein injection of Pachyman together with intraperitoneal lipopolysaccharide (LPS) induced the highest levels of these cytokines at 3 h post-injection than LPS alone or LPS with other BGs. With bone marrow-derived macrophages, BG induced only TNF-α (most prominent with Pachyman), while LPS with BG additively increased several cytokines (TNF-α, IL-6, and IL-10); inflammatory genes (iNOS, IL-1β, Syk, and NF-κB); and cell energy alterations (extracellular flux analysis). In conclusion, Pachyman induced the highest LPS proinflammatory synergistic effect on macrophages, followed by WGP, possibly through Syk-associated interactions between the Dectin-1 and TLR-4 signal transduction pathways. Selection of the proper form of BGs for specific clinical conditions might be beneficial.

Baicalin Magnesium Salt Attenuates Lipopolysaccharide-Induced Acute Lung Injury via Inhibiting of TLR4/NF-κB Signaling Pathway

Baicalin (BA) magnesium salt (BA-Mg) is a good water-soluble ingredient extracted from Scutellaria baicalensis Georgi, a commonly used traditional Chinese medicine. This study is aimed at investigating whether BA-Mg could exert a better protective effect on lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice and illuminate the underlying mechanisms in vivo and in vitro. Mice were intraperitoneally administrated with equimolar BA-Mg, BA, and MgSO₄ before LPS inducing ALI. Lung tissues and bronchoalveolar lavage fluid were collected for lung wet/dry ratio, histological examinations, cell counts, and biochemical analyses at 48 h post-LPS exposure. Meanwhile, the protein expressions of TLR4/NF-κB signaling pathway and proinflammatory cytokines in lung tissues and lung bronchial epithelial cells (BEAS-2B) were detected. The results showed BA-Mg pronouncedly ameliorated LPS-induced inflammatory response and histopathological damages, elevated antioxidant enzyme activity (SOD), and downregulated myeloperoxidase (MPO) and malonaldehyde (MDA) levels through the inhibition of TLR4/NF-κB signaling pathway activation. Moreover, the effect of BA-Mg was significantly better than that of BA and MgSO₄ in ameliorating symptoms. Overall, BA-Mg can effectively relieve inflammatory response and oxidative stress triggered by LPS, indicating it may be a potential therapeutic candidate for treating ALI.

The protective role of fosfomycin in lung injury due to oxidative stress and inflammation caused by sepsis

AIM

Early and prompt treatment of sepsis by effective antibiotics against susceptible organisms may be lifesaving. However, increased antibiotic resistance and side effects of chemotherapeutic agents limiting their tolerability result in a restricted use of medications. This has led to an increased search for solution oriented novel treatments and therapeutic targets, as well as investigations on the pathogenesis and physiology of sepsis. In this study, we aimed to examine the antioxidant and anti-inflammatory effects of fosfomycin in sepsis resulting from other causes.

MAIN METHODS

Sprague Dawley rats were assigned into three groups. Randomly selected control rats received intraperitoneal saline solution only. Only caecal puncture and ligation were carried out in the caecal ligation and puncture (CLP) group, while in the CLP + fosfomycin group (CLP + FOS), together with sepsis due to caecal puncture and ligation, 500 mg/kg of FOS was administered intraperitoneally (i.p.).

KEY FINDINGS

As compared to the control group, elevated TBARS and TNF-α levels as well as increased expression of NF-kB/p65 and TLR-4 and reduced -SH levels were found in the lung tissue of CLP rats. On the other hand, TBARS and TNF-α levels were reduced and NF-kB/p65 and TLR-4 expressions were decreased together with increase in total -SH levels among CLP + FOS (500 mg/kg i.p.) rats.

SIGNIFICANCE

FOS treatment may represent a promising agent in terms of reducing the sepsis-related lung injury due to its antimicrobial effects as well as its antioxidant and anti-inflammatory properties.

PDX regulates inflammatory cell infiltration via resident macrophage in LPS-induced lung injury

Inflammatory cell infiltration contributes to the pathogenesis of acute respiratory distress syndrome (ARDS). Protectin DX (PDX), an endogenous lipid mediator, shows anti‐inflammatory and proresolution bioactions. In vivo, the mice were intraperitoneally injected with PDX (0.1 µg/mouse) after intratracheal (1 mg/kg) or intraperitoneal (10 mg/kg) LPS administration. Flow cytometry was used to measure inflammatory cell numbers. Clodronate liposomes were used to deplete resident macrophages. RT‐PCR, and ELISA was used to measure MIP‐2, MCP‐1, TNF‐α and MMP9 levels. In vitro, sorted neutrophils, resident and recruited macrophages (1 × 10⁶) were cultured with 1 μg/mL LPS and/or 100 nmol/L PDX to assess the chemokine receptor expression. PDX attenuated LPS‐induced lung injury via inhibiting recruited macrophage and neutrophil recruitment through repressing resident macrophage MCP‐1, MIP‐2 expression and release, respectively. Finally, PDX inhibition of neutrophil infiltration and transmembrane was associated with TNF‐α/MIP‐2/MMP9 signalling pathway. These data suggest that PDX attenuates LPS‐stimulated lung injury via reduction of the inflammatory cell recruitment mediated via resident macrophages.

MicroRNA-182 supplies negative feedback regulation to ameliorate lipopolysaccharide-induced ALI in mice by targeting TLR4

Acute lung injury (ALI), characterized by increased excessive pulmonary inflammation, is a pervasive inflammatory disease with clinically high incidence. MicroRNA (miRNAs) have been associated with the progression of multiple diseases and are regarded as novel regulators of inflammation. However, it remains largely unknown whether the miRNAs-mediated regulatory mechanism has an effect on lipopolysaccharide (LPS)-induced inflammation in ALI. We discovered that miR-182 distinctly lessened expression in the lung tissue of mice with ALI and macrophages stimulated by LPS. We also found that overexpression of miR-182 significantly cut down the secretion of inflammatory cytokines, while this change was reversed by inhibition of miR-182. In addition, miR-182 suppressed the activation of NF-κB by targeting TLR4 expression. And it was confirmed that miR-182 directly regulated TLR4 expression at the posttranscriptional level by binding to the 3'-UTR of TLR4. Together, these data suggested that inhibition of TLR4 expression assuaged LPS-stimulated inflammation through negative feedback regulation of miR-182.

MicroRNA-106a Provides Negative Feedback Regulation in Lipopolysaccharide-Induced Inflammation by targeting TLR4

Acute lung injury (ALI) is a common clinical disease with high incidence and mortality rate, which is characterized by severe inflammatory response and tissues damage. MicroRNAs (miRNAs) have been regarded as novel regulators of inflammation, and play an important role in various inflammatory diseases. However, it remains unknown whether the regulatory mechanisms mediated by miR-106a is involved in LPS-induced ALI. In this study, we found that expression of miR-106a was significantly decreased in lung tissues of ALI mice and LPS-stimulated macrophages. We also revealed that over-expression of miR-106a significantly decreased the production of pro-inflammatory cytokines, including IL-1β, IL-6 and TNF-α, whereas this effect was reversed by the inhibition of miR-106a. Moreover, miR-106a inhibits NF-κB activation by targeting TLR4 expression. We further demonstrated that miR-106a inhibited TLR4 expression via binding directly to the 3'-UTR of TLR4. Taken together, the results of the present study illuminated that miR-106a is a negative feedback regulator in LPS-stimulated inflammation through TLR4/NF-κB signaling pathway.

Integrated therapy decreases the mortality of patients with polymyositis and dermatomyositis: A Taiwan-wide population-based retrospective study

ETHNOPHARMACOLOGICAL RELEVANCE

The issue of whether integrated treatment with conventional medicine (CM) and herbal medicine (HM) can reduce mortality in patients with polymyositis/dermatomyositis (PM/DM) had not been addressed.

AIM OF THE STUDY

In this study, we investigated the effect of integrated therapy on mortality in a retrospective PM/DM cohort in the Taiwan National Health Insurance Research Database (NHIRD).

MATERIALS AND METHODS

Patients with PM/DM were retrospectively enrolled from the PM/DM Registry of Catastrophic Illnesses cohort in the Taiwan NHIRD between 1997 and 2011. The patients were divided into an integrated medicine (IM) group that received CM and HM and a non-IM group that received CM alone. The Cox proportional hazards regression model and Kaplan-Meier method were used to evaluate the hazard ratio (HR) for mortality.

RESULTS

Three hundred and eighty-five of 2595 patients with newly diagnosed PM/DM had received IM and 99 had received non-IM. The adjusted HR for mortality was lower in the IM group than in the non-IM group (0.42, 95% confidence interval 0.26-0.68, p < 0.001). The adjusted HR for mortality was also lower in the IM group that had received CM plus HM than in the group that received CM alone (0.48, 95% confidence interval 0.28-0.84, p < 0.05). The core pattern of HM prescriptions integrated with methylprednisolone, methotrexate, azathioprine, or cyclophosphamide to decrease mortality included "San-Qi" (Panax notoginseng), "Bai-Ji" (Bletilla striata), "Chen-Pi" (Citrus reticulata), "Hou-Po" (Magnolia officinalis), and "Dan-Shan" (Salvia miltiorrhiza).

CONCLUSION

Integrated therapy has reduced mortality in patients with PM/DM in Taiwan. Further investigation of the clinical effects and pharmaceutical mechanism involved is needed.

Protective effects of the suppressed NF-κB/TLR4 signaling pathway on oxidative stress of lung tissue in rat with acute lung injury

The pathogenesis of acute lung injury (ALI) is characterized by lung inflammation and lung oxidative stress. The study was conducted in order to investigate the effect toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) exhibited on oxidative stress in ALI. After the rats had been assigned into different groups, arterial blood, white blood cell (WBC), lung permeability index (LPI), wet/dry (W/D) ratio, TLR4 and NF-κB expression and superoxide dismutase (SOD), myeloperoxidase (MPO), malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS) were examined. Afterward, the correlation between the levels of TLR4 and NF-κB was determined. Decreased levels of PaO₂ , SOD, MPO, and GSH accompanied by increased levels of PaCO₂ , WBC number, LPI and W/D ratio, MDA and ROS, as well as TLR4 and NF-κB expressions in the ALI, ALI + NF-κB inhibitor, and ALI + phosphate buffer saline groups were found. Inhibition of NF-κB resulted in increased PaO₂ and decreased PaCO₂ levels, WBC number, and LPI and W/D ratio. Decreased expression of NF-κB increased SOD, GSH, and MPO, but decreased MDA and ROS. We also found that NF-κB inhibition resulted in the improvement of ALI in rats. TLR4 and NF-κB expressions were negatively correlated with levels of SOD, MPO, and GSH, and positively correlated with MDA and ROS levels. In summary, our findings provided evidence that inhibition of the TLR4/NF-κB signaling pathway decreases oxidative stress, thereby improving ALI. As a result, NF-κB signaling pathway has shown potential as a therapeutic target in ALI therapy.

Telomere shortening activates TGF-β/Smads signaling in lungs and enhances both lipopolysaccharide and bleomycin-induced pulmonary fibrosis

Telomere shortening is associated with idiopathic pulmonary fibrosis (IPF), a high-morbidity and high-mortality lung disease of unknown etiology. However, the underlying mechanisms remain largely unclear. In this study, wild-type (WT) mice with normal telomeres and generation 3 (G3) or G2 telomerase RNA component (TERC) knockout Terc^-/- mice with short telomeres were treated with and without lipopolysaccharide (LPS) or bleomycin by intratracheal injection. We show that under LPS induction, G3 Terc^-/- mice develop aggravated pulmonary fibrosis as indicated by significantly increased α-SMA, collagen I and hydroxyproline content. Interestingly, TGF-β/Smads signaling is markedly activated in the lungs of G3 Terc^-/- mice, as indicated by markedly elevated levels of phosphorylated Smad3 and TGF-β1, compared with those of WT mice. This TGF-β/Smads signaling activation is significantly increased in the lungs of LPS-treated G3 Terc^-/- mice compared with those of LPS-treated WT or untreated G3 Terc^-/- mice. A similar pattern of TGF-β/Smads signaling activation and the enhancing role of telomere shortening in pulmonary fibrosis are also confirmed in bleomycin-induced model. Moreover, LPS challenge produced more present cellular senescence, apoptosis and infiltration of innate immune cells, including macrophages and neutrophils in the lungs of G3 Terc^-/- mice, compared with WT mice. To our knowledge, this is the first time to report telomere shortening activated TGF-β/Smads signaling in lungs. Our data suggest that telomere shortening cooperated with environment-induced lung injury accelerates the development of pulmonary fibrosis, and telomere shortening confers an inherent enhancing factor to the genesis of IPF through activation of TGF-β/Smads signaling.

So-Cheong-Ryoung-Tang Attenuates Pulmonary Inflammation Induced by Cigarette Smoke in Bronchial Epithelial Cells and Experimental Mice

So-Cheong-Ryoung-Tang is a traditionally used herbal formula for the treatment of pulmonary diseases in China, Korea, and Japan. We investigated the protective effects of So-Cheong-Ryong-Tang water extract (SCWE) in cigarette smoke concentrate (CSC) stimulated human airway epithelial cell line NCI-H292 and mice exposed cigarette smoke (CS) and lipopolysaccharide (LPS). In the CSC-stimulated NCI-H292 cells, SCWE inhibited proinflammatory cytokines in a concentration-dependent manner, as evidenced by a reduction in their mRNA levels. Also, SCWE significant reduced inducible nitric oxide synthase (iNOS) expression and nuclear factor kappa B (NF-κB) phosphorylation in CSC-stimulated cells. The mice were exposed to CS for 1 h per day (a total of eight cigarettes per day) for 7 days and received LPS intranasally on day 5. The mice were administered a dose of SCWE (100 and 200 mg/kg) 1 h before CS exposure. In in vivo, SCWE decreased the inflammatory cell count and reduced the expression of the proinflammatory cytokines in the broncho-alveolar lavage fluid (BALF) compared with CS and LPS exposed mice. SCWE attenuated inflammatory cell infiltration in airway induced by CS and LPS exposure, and this decrease was accompanied by a reduction in the expression levels of iNOS and MMP-9 in lung tissue. The extract also inhibited the phosphorylation of inhibitor of kappa B alpha (IκBα) and NF-κB induced by CS and LPS exposure in lung tissue. These results suggest that SCWE may effectively inhibit airway inflammatory responses induced by CS and LPS exposure via the NF-κB pathway. Therefore, SCWE may be a potential treatment for airway inflammatory diseases, such as chronic obstructive pulmonary disease (COPD).

LipoxinA4 attenuates acute pancreatitis-associated acute lung injury by regulating AQP-5 and MMP-9 expression, anti-apoptosis and PKC/SSeCKS-mediated F-actin activation

An essential component of acute pancreatitis(AP)-induced acute lung injury(ALI) is the inflammation that is part of the body's systemic inflammatory response to a variety of systemic stimuli. Lipoxins(LXs) are considered important endogenous lipids that mediate the resolution of inflammation. In previous studies, we found that Lipoxin A4 (LXA4) reduced AP-induced pulmonary oedema and TNF-α production in lung. However, the underlying mechanism remains unclear. Due to the above studies, we investigated the aquaporin, matrix metalloprotein, apoptosis and PKC/SSeCKS signal pathway in cellular and animal models of AP-associated lung injury following LXA4 intervention. In this study, we first proved LXA4 could effectively promote F-actin reconstruction and regulate its expression in pulmonary microvascular endothelial cells both in vivo and vitro via suppressing PKC/SSeCKS signalling pathway. Next, we found that LXA4 attenuated cell growth inhibition and apoptosis in lung tissues of AP-ALI mice and HPMECs. Additionally, we demonstrated that LXA4 could regulate the expression of AQP-5 and MMP-9 to stabilize the permeability of pulmonary microvascular endothelial cell. In summary, our results suggest that the anti-inflammatory eff ;ects of LXA4 may be due to the inhibition of both the PKC/SSeCKS pathway and apoptosis to reduce alveolar fluid exudation and to the regulation of AQP-5 and MMP-9 expression to maintain the clearance of alveolar fluid. Thus, LXA4 is capable of exerting protective eff ;ects on AP-induced ALI.

Upregulation of miRNA-140-5p inhibits inflammatory cytokines in acute lung injury through the MyD88/NF-κB signaling pathway by targeting TLR4

The present study was designed to determine the effect of miR-140-5p on acute lung injury (ALI) and the associated inflammation induced. As a result, miR-140-5p expression in mice with ALI was suppressed when compared with the normal group. Downregulation of miR-140-5p increased the levels of inflammatory factors induced by ALI [including tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and myeloperoxidase] in an in vitro model of human lung A549 cells. Downregulation of miR-140-5p also induced the protein expression of Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88) and nuclear factor (NF)-κB in an in vitro model. Overexpression of miR-140-5p reduced the levels of inflammation in the in vitro model of ALI via the suppression of the TLR4/MyD88/NF-κB signaling pathway. The inhibition of TLR4 using a TLR4 inhibitor reduced the proinflammation effects of anti-miR-140-5p in the in vitro model of ALI. The NF-κB inhibitor also inhibited the proinflammation effects of anti-miR-140-5p in the in vitro model of ALI. Overall, the results of the present study indicated that miR-140-5p inhibited ALI-induced inflammation via the TLR4/MyD88/NF-κB signaling pathway.

3,4,5-Trihydroxycinnamic acid attenuates lipopolysaccharide (LPS)-induced acute lung injury via downregulating inflammatory molecules and upregulating HO-1/AMPK activation

The increase in inflammatory cytokines and chemokines is a common denominator in the pathogenesis of acute lung injury (ALI) which are involved in the influx of inflammatory cells and lung damage. The aim of the present study was to evaluate the protective effect of 3,4,5-trihydroxycinnamic acid (THC) in lipopolysaccharide (LPS)-induced ALI. THC efficiently decreased the mRNA expression of interleukin-8 (IL-8) in LPS-stimulated A549 airway epithelial cells. THC induced heme oxygenase-1 (HO-1) expression in A549 cells. THC also increased the activation of AMP-activated protein kinase (AMPK) in A549 cells and RAW264.7 macrophages. In LPS-induced ALI in mice, THC significantly suppressed neutrophil influx and monocyte chemoattractant protein-1 (MCP-1) production in the bronchoalveolar lavage fluid (BALF). THC also attenuated the levels of neutrophil elastase (NE), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the BALF and serum. In addition, THC inhibited the expressions of inducible nitric oxide synthase (iNOS) and the activation of nuclear factor-kappa B (NF-κB) in the lung. These protective effects of THC were accompanied with HO-1 induction and AMPK activation. Taken together, the present study clearly demonstrates that THC significantly attenuates the LPS-induced ALI, suggesting that THC might be a valuable therapeutic adjuvant in airway inflammatory disorders.

MicroRNA-27a protects retinal pigment epithelial cells under high glucose conditions by targeting TLR4

The present study aimed to investigate whether microRNA-27a (miRNA27a) is associated with the pathogenesis of diabetic retinopathy, and to elucidate the underlying molecular mechanism of any potential association. In retinal pigment epithelial (RPE) cells treated with high glucose, miRNA27a expression, determined by reverse transcription-quantitative polymerase chain reaction analysis, was decreased. Caspase-3/9 activity and B-cell lymphoma 2-associated X (Bax) protein expression was increased in RPE cells subjected to high glucose. Inhibition of miRNA27a suppressed the viability, and increased the caspase-3/9 activity and Bax protein expression of RPE cells treated with high glucose. Inhibition of miRNA27a expression also increased the expression of interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α and Toll-like receptor 4 (TLR4) in RPE cells treated with high glucose. Treatment with immunostimulatory (is)RNA directed against TLR4 was observed to inhibit caspase-3/9 activity, decrease the expression of TLR4, Bax, IL-6, IL-1β and TNF-α, and increase the viability of RPE cells subjected to high glucose following the inhibition miRNA27a. In conclusion, the results of the present study suggest that miRNA27a protects RPE cells subjected to high glucose via inhibiting inflammation and apoptosis through targeting TLR4.

Transduced PEP-1-Heme Oxygenase-1 Fusion Protein Attenuates Lung Injury in Septic Shock Rats

Oxidative stress and inflammation have been identified to play a vital role in the pathogenesis of lung injury induced by septic shock. Heme oxygenase-1 (HO-1), an effective antioxidant and anti-inflammatory and antiapoptotic substance, has been used for the treatment of heart, lung, and liver diseases. Thus, we postulated that administration of exogenous HO-1 protein transduced by cell-penetrating peptide PEP-1 has a protective role against septic shock-induced lung injury. Septic shock produced by cecal ligation and puncture caused severe lung damage, manifested in the increase in the lung wet/dry ratio, oxidative stress, inflammation, and apoptosis. However, these changes were reversed by treatment with the PEP-1-HO-1 fusion protein, whereas lung injury in septic shock rats was alleviated. Furthermore, the septic shock upregulated the expression of Toll-like receptor 4 (TLR4) and transcription factor NF-κB, accompanied by the increase of lung injury. Administration of PEP-1-HO-1 fusion protein reversed septic shock-induced lung injury by downregulating the expression of TLR4 and NF-κB. Our study indicates that treatment with HO-1 protein transduced by PEP-1 confers protection against septic shock-induced lung injury by its antioxidant, anti-inflammatory, and antiapoptotic effects.

Astragalus membranaceus and Salvia miltiorrhiza Ameliorate Lipopolysaccharide-Induced Acute Lung Injury in Rats by Regulating the Toll-Like Receptor 4/Nuclear Factor-Kappa B Signaling Pathway

Astragalus membranaceus and Salvia miltiorrhiza (AM/SM) are well used in Traditional Chinese Medicines (TCM) for nourishing Qi and activating blood circulation method. From TCM theory, the pathogenesis of acute lung injury (ALI) was determined as Qi deficiency and blood stagnation. In this study, we are aiming to investigate the protective and therapeutic effects of AM/SM on a rat model of lipopolysaccharide- (LPS-) induced ALI in rats and to elucidate potential molecular mechanisms. ALI was induced by intratracheal instillation of LPS (5 mg/kg) in Sprague–Dawley rats. SM/AM was given orally before and after LPS administration. Results demonstrated that AM/SM attenuated lung histopathological changes induced by LPS, decreased wet/dry weight ratios and protein concentrations, and inhibited the production of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in BALF. Moreover, AM/SM significantly downregulated protein and mRNA expression of toll-like receptors 4 (TLR-4), interleukin-1 receptor-associated kinase-1 (IRAK-1), and nuclear factor-kappa B (NF-κB/p65). These findings suggest that AM/SM showed protective and therapeutic effects in LPS-induced ALI rat through modulating TLR-4 signaling pathways. Nourishing Qi and activating blood circulation may be a beneficial treatment for ALI.

SiRNA directed against NF‑κB inhibits mononuclear macrophage cells releasing proinflammatory cytokines in vitro

Acute lung injury (ALI) is a condition of acute respiratory failure, characterized by diffuse pulmonary infiltrates and severe hypoxemia. During ALI, the acute phase of inflammation induces the recruitment of activated inflammatory cells, including macrophages and lymphocytes, to the damaged lesions. Nuclear factor (NF)‑κB is a key protein in many signal transduction pathways, over‑activation of which is followed by an approach of inflammation cells and release of pre‑inflammation cytokines. The aim of the present study was to explore the effect of NF‑κB P65 siRNA retroviruses on the activation of NF‑κB signaling pathway and release of pro‑inflammatory cytokines in THP‑1 cells. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting were used to detect the NF‑κB p65 mRNA and protein expression at different times in THP‑1 cells infected by p65 siRNA retroviruses. The results revealed that p65 siRNA retroviruses could significantly inhibit the expression levels of NF‑κB p65 mRNA and protein at different times. In addition, to further investigate the effect of p65 siRNA retroviruses on the pro‑inflammatory cytokines release stimulated by LPS, the expression of IL‑1β in THP‑1 cells and TNF‑α in THP‑1/M cells was also detected using RT‑qPCR and ELISA. As a result, the level of released proinflammatory cytokine interleukin‑1β and tumor necrosis factor‑α stimulated was significantly inhibited at different times infected by p65 siRNA retroviruses, while increased at different times infected by siControl retroviruses in THP‑1 and THP‑1/M cells stimulated by LPS. In summary, the present study demonstrated that p65 siRNA retroviruses could suppress the activation of NF‑κB signal pathway and release of pro‑inflammatory cytokines in THP‑1 cells which provided a clinically plausible method to inhibit the inflammation for ALI/ARDS utilizing RNA interference technology.

Phycocyanin attenuates pulmonary fibrosis via the TLR2-MyD88-NF-κB signaling pathway

Our aim was to investigate the effects of phycocyanin (PC) on bleomycin (BLM)-induced pulmonary fibrosis (PF). In this study, C57 BL/6 wild-type (WT) mice and toll-like receptor (TLR) 2 deficient mice were treated with PC for 28 days following BLM exposure. Serum and lung tissues were collected on days 3, 7 and 28. Data shows PC significantly decreased the levels of hydroxyproline (HYP), vimentin, surfactant-associated protein C (SP-C), fibroblast specific protein-1 (S100A4) and α-smooth muscle actin (α-SMA) but dramatically increased E-cadherin and podoplanin (PDPN) expression on day 28. Moreover, PC greatly decreased the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and myeloperoxidase (MPO) at the earlier time. Reduced expression of key genes in the TLR2 pathway was also detected. Compared with WT mice, TLR2-deficient mice exhibited less injury, and the protective effect of PC was partly diminished in this background. These data indicate the anti-fibrotic effects of PC may be mediated by reducing W/D ratio, MPO, IL-6, TNF-α, protecting type I alveolar epithelial cells, inhibiting fibroblast proliferation, attenuating epithelial-mesenchymal transitions (EMT) and reducing oxidative stress. The TLR2-MyD88-NF-κB pathway plays an important role in PC-mediated reduction in pulmonary fibrosis.

Depletion of circulating monocytes suppresses IL-17 and HMGB1 expression in mice with LPS-induced acute lung injury

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is an important cause of mortality in critically ill patients. Macrophages play an important role in the pathogenesis of ALI/ARDS. To investigate the role and underlying mechanisms of circulating monocytes and resident alveolar macrophages (AMs) in ALI/ARDS, we depleted circulating monocytes and AMs by clodronate-loaded liposome (CL) in a lipopolysaccharide (LPS)-induced ALI/ARDS mouse model. Our results indicated that depletion of circulating monocytes by intravenous injection of CL 2 days before intratracheal LPS treatment significantly suppressed the acute lung injury in mice with ALI/ARDS, accompanied with significant reduction in neutrophil influx, interleukin-17, monocyte chemoattractant protein 1, high-mobility group box 1 protein, suppressor of cytokine signaling 3, and surfactant protein D (SP-D) in the lungs of 2 days intratracheal LPS-treated mice. In contrast, depletion of AMs by intratracheal delivery of CL enhanced the acute lung injury in association with upregulation of these mediators. Blocking monocyte chemoattractant protein 1 signaling by intraperitoneal instillation of anti-mouse CCL2 neutralizing antibody significantly reduced acute lung injury and neutrophil influx. In addition, SP-D was upregulated by mediators released from AMs because primary murine type II alveolar epithelial cells expressed more SP-D after treatment with bronchoalveolar lavage from LPS-treated mice or the conditioned media from LPS-treated RAW 264.7 cells. The results indicated that circulating monocytes are proinflammatory, but AMs have anti-inflammatory functions in the early phase of ALI/ARDS. The study provided a molecular basis for the treatment of ALI/ARDS through modulation of circulating monocytes and AMs.

Dose Dependent Dual Effect of Baicalin and Herb Huang Qin Extract on Angiogenesis

Huang Qin (root of Scutellaria baicalensis) is a widely used herb in different countries for adjuvant therapy of inflammation, diabetes, hypertension, different kinds of cancer and virus related diseases. Baicalin is the main flavonoid in this herb and has been extensively studied for 30 years. The angiogenic effect of herb Huang Qin extract and baicalin was found 13 years ago, however, the results were controversial with pro-angiogenic effect in some studies and anti-angiogenic effect in others. In this paper, the angiogenic effect of baicalin, its aglycone form baicalein and aqueous extract of Huang Qin was studied in chick embryo chorioallantoic membrane (CAM) model. Dose dependent dual effect was found in both aqueous extract and baicalin, but not in baicalein, in which only inhibitory effect was observed. In order to reveal the cellular and molecular mechanism of how baicalin and baicalein affect angiogenesis, cell proliferation and programmed cell death assays were performed in treated CAM. In addition, quantitative PCR array including 84 angiogenesis related genes was used to detect high and low dosage of baicalin and baicalein responsive genes. Low dose baicalin increased cell proliferation in developing blood vessels through upregulation of multiple angiogenic genes expression, but high dose baicalin induced cell death, performing inhibitory effect on angiogenesis. Both high and low dose of baicalein down regulated the expression of multiple angiogenic genes, decreased cell proliferation, and leads to inhibitory effects on angiogenesis.

Ratiometric Two-Photon Fluorescent Probe for in Vivo Hydrogen Polysulfides Detection and Imaging during Lipopolysaccharide-Induced Acute Organs Injury

Acute organ injury observed during sepsis, caused by an uncontrolled release of inflammatory mediators, such as lipopolysaccharide (LPS), is quite fatal. The development of efficient methods for early diagnosis of sepsis and LPS-induced acute organ injury in living systems is of great biomedical importance. In living systems, cystathionine γ-lyase (CSE) can be overexpressed due to LPS, and H₂S_n can be formed by CSE-mediated cysteine metabolism. Thus, acute organ injury during sepsis may be correlated with H₂S_n levels, making accurate detection of H₂S_n in living systems of great physiological and pathological significance. In this work, our previously reported fluorescent platform was employed to design and synthesize a FRET-based ratiometric two-photon (TP) fluorescent probe TPR-S, producing a large emission shift in the presence of H₂S_n. In this work, a naphthalene derivative two-photon fluorophore was chosen as the energy donor; a rhodol derivative fluorophore served as the acceptor. The 2-fluoro-5-nitrobenzoate group of probe TPR-S reacted with H₂S_n and was selectively removed to release the fluorophore, resulting in a fluorescent signal decrease at 448 nm and enhancement at 541 nm. The ratio value of the fluorescence intensity between 541 and 448 nm (I_541 nm/I_448 nm) varied from 0.13 to 8.12 (∼62-fold), with the H₂S_n concentration changing from 0 to 1 mM. The detection limit of the probe was 0.7 μM. Moreover, the probe was applied for imaging H₂S_n in living cells, tissues, and organs of LPS-induced acute organ injury, which demonstrated its practical application in complex biosystems as a potential method to achieve early diagnosis of LPS-induced acute organ injury.