Molecular Hydrogen as a Promising Therapy Could Be Linked With Increased Resting Treg Cells or Decreased Fas+ T Cell Subsets in a IgG4-PF-ILD Patient: A Case Report.

BACKGROUND/AIM: Progressive fibrosing interstitial lung disease (PF-ILD) refers to a group of chronic lung conditions commonly associated with immunoglobulin G4-related disorders. It is characterized by progressive scarring (fibrosis) within the pulmonary interstitium, resulting in respiratory failure and early mortality. Some patients do not respond to standard therapeutic interventions. Numerous studies have confirmed the anti-inflammatory and antioxidant properties of molecular hydrogen in various disease models. CASE REPORT: In this report, we present a case study of an 85-year-old female diagnosed with suspected IgG4-related PF-ILD complicated by hospital-acquired pneumonia. On the fourth day of hydrogen-assisted therapy, a noticeable improvement in lung infiltrations was observed in chest X-rays as the patient gradually progressed towards weaning off mechanical ventilation. To assess treatment responses, we compared immune phenotypes before and after hydrogen treatment. A marked increase was observed in resting regulatory T cell levels after treatment, accompanied by a notable decrease in Fas+ helper T cell and cytotoxic T cell subtypes. CONCLUSION: This case study highlights the effectiveness of hydrogen-assisted therapy in managing PF-ILD complicated by pneumonia, warranting further research in the future.

Alda-1 ameliorates air embolism-induced acute lung injury.

OBJECTIVE: Evidence suggests that aldehyde dehydrogenase 2 (ALDH2) offers protection against damage caused by oxidative stress in diverse rodent models. Nonetheless, the effect of Alda-1, a compound that activates ALDH2, on acute lung injury (ALI) induced by air embolism (AE) remains unclear. The objective of this study was to explore the protective effects of Alda-1 in ALI induced by AE. METHODS: A rat model of in situ isolated perfused lung was established to investigate AE-induced ALI. Air was infused into the pulmonary artery at 0.25 mL/min for 1 minute. Before inducing AE, different doses (10, 20, or 30 mg/kg) of Alda-1 were given through intraperitoneal injection. Pathological changes in lung tissue were assessed using hematoxylin-eosin staining. We performed Western blot analysis to assess the protein levels of ALDH2,4-hydroxy-trans-2-nonenal (4-HNE), Bcl-2, caspase-3, phosphatidylinositol 3-kinase (PI3K), Akt, IκB-α, and nuclear NF-κB. RESULTS: Notably, AE results were demonstrated as harmful to the lungs, which is evidenced by intensified lung edema and disruption of lung tissue structure. Furthermore, AE caused a decrease in ALDH2 expression, increased accumulation of 4-HNE and MDA, infiltration of neutrophils, increased production of inflammatory cytokines, apoptosis, and upregulation of the PI3K/Akt and NF-κB signaling pathways within the lungs. Administration of a 20 mg/kg dose of Alda-1 alleviated the detrimental effects induced by AE. CONCLUSION: Alda-1 shows promise in mitigating AE-induced ALI, possibly through the upregulation of ALDH2 expression and suppression of the PI3K/Akt and NF-κB signaling pathways. Further research is warranted to validate these findings and to explore their translational potential in human subjects.

Protease-Activated Receptor-1 Antagonist Protects Against Lung Ischemia/Reperfusion Injury.

Protease-activated receptor (PAR)-1 is a thrombin-activated receptor that plays an essential role in ischemia/reperfusion (IR)-induced acute inflammation. PAR-1 antagonists have been shown to alleviate injuries in various IR models. However, the effect of PAR-1 antagonists on IR-induced acute lung injury (ALI) has not yet been elucidated. This study aimed to investigate whether PAR-1 inhibition could attenuate lung IR injury. Lung IR was induced in an isolated perfused rat lung model. Male rats were treated with the specific PAR-1 antagonist SCH530348 (vorapaxar) or vehicle, followed by ischemia for 40 min and reperfusion for 60 min. To examine the role of PAR-1 and the mechanism of SCH530348 in lung IR injury, western blotting and immunohistochemical analysis of lung tissue were performed. In vitro, mouse lung epithelial cells (MLE-12) were treated with SCH530348 or vehicle and subjected to hypoxia-reoxygenation (HR). We found that SCH530348 decreased lung edema and neutrophil infiltration, attenuated thrombin production, reduced inflammatory factors, including cytokine-induced neutrophil chemoattractant-1, interleukin-6 and tumor necrosis factor-α, mitigated lung cell apoptosis, and downregulated the phosphoinositide 3-kinase (PI3K), nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in IR-injured lungs. In addition, SCH530348 prevented HR-induced NF-κB activation and inflammatory chemokine production in MLE12 cells. Our results demonstrate that SCH530348 exerts protective effects by blocking PAR-1 expression and modulating the downstream PI3K, NF-κB and MAPK pathways. These findings indicate that the PAR-1 antagonist protects against IR-induced ALI and is a potential therapeutic candidate for lung protection following IR injury.

Pre-Treatment with Ten-Minute Carbon Dioxide Inhalation Prevents Lipopolysaccharide-Induced Lung Injury in Mice via Down-Regulation of Toll-Like Receptor 4 Expression.

Various animal studies have shown beneficial effects of hypercapnia in lung injury. However, in patients with acute respiratory distress syndrome (ARDS), there is controversial information regarding the effect of hypercapnia on outcomes. The duration of carbon dioxide inhalation may be the key to the protective effect of hypercapnia. We investigated the effect of pre-treatment with inhaled carbon dioxide on lipopolysaccharide (LPS)-induced lung injury in mice. C57BL/6 mice were randomly divided into a control group or an LPS group. Each LPS group received intratracheal LPS (2 mg/kg); the LPS groups were exposed to hypercapnia (5% carbon dioxide) for 10 min or 60 min before LPS. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected to evaluate the degree of lung injury. LPS significantly increased the ratio of lung weight to body weight; concentrations of BALF protein, tumor necrosis factor-α, and CXCL2; protein carbonyls; neutrophil infiltration; and lung injury score. LPS induced the degradation of the inhibitor of nuclear factor-κB-α (IκB-α) and nuclear translocation of NF-κB. LPS increased the surface protein expression of toll-like receptor 4 (TLR4). Pre-treatment with inhaled carbon dioxide for 10 min, but not for 60 min, inhibited LPS-induced pulmonary edema, inflammation, oxidative stress, lung injury, and TLR4 surface expression, and, accordingly, reduced NF-κB signaling. In summary, our data demonstrated that pre-treatment with 10-min carbon dioxide inhalation can ameliorate LPS-induced lung injury. The protective effect may be associated with down-regulation of the surface expression of TLR4 in the lungs.

The Blockade of Store-Operated Calcium Channels Improves Decompression Sickness in Rats.

BACKGROUND: Previous investigations reveal that BTP2, a store-operated calcium channel blocker, has protective and anti-inflammatory properties in multiple inflammatory diseases. This study investigates whether BTP2 can protect against decompression sickness (DCS) in a rat model. METHODS: BTP2 (2 mg/kg) was administered to male Sprague-Dawley rats 30 min before subjecting them to hyperbaric pressure. Control rats were not treated. After decompression, signs of DCS were examined, and samples of bronchoalveolar lavage fluid and lung tissue were obtained for evaluation. RESULTS: The incidence and mortality of DCS were decreased significantly in rats treated with BTP2 compared to those treated with dimethyl sulfoxide. BTP2 significantly attenuated DCS-induced lung edema, histological evidence of lung inflammation, necroptosis, and apoptosis, while it decreased levels of tumor necrosis factor alpha, interleukin-6, and cytokine-induced neutrophil chemoattractant-1 in bronchoalveolar lavage fluid. In addition, BTP2 reduced the expression of nuclear factor of activated T cells and early growth response protein 3 in lung tissue. BTP2 also significantly increased the levels of inhibitor kappa B alpha and suppressed the levels of nuclear factor kappa B in lung tissue. CONCLUSION: The results suggest that BTP2 may has potential as a prophylactic therapy to attenuate DCS-induced injury.

Ac2-26, an Annexin A1 Peptide, Attenuates Ischemia-Reperfusion-Induced Acute Lung Injury.

Annexin A1 (AnxA1) is an endogenous protein that modulates anti-inflammatory processes, and its therapeutic potential has been reported in a range of inflammatory diseases. The effect of AnxA1 on ischemia-reperfusion (IR)-induced lung injury has not been examined. In this study, isolated, perfused rat lungs were subjected to IR lung injury induced by ischemia for 40 min, followed by reperfusion for 60 min. The rat lungs were randomly treated with vehicle (phosphate-buffered saline), and Ac2-26 (an active N-terminal peptide of AnxA1) with or without an N-formyl peptide receptor (FPR) antagonist N-Boc-Phe-Leu-Phe-Leu-Phe (Boc2). An in vitro study of the effects of Ac2-26 on human alveolar epithelial cells subjected to hypoxia-reoxygenation was also investigated. Administration of Ac2-26 in IR lung injury produced a significant attenuation of lung edema, pro-inflammatory cytokine production recovered in bronchoalveolar lavage fluid, oxidative stress, apoptosis, neutrophil infiltration, and lung tissue injury. Ac2-26 also decreased AnxA1 protein expression, inhibited the activation of nuclear factor-κB and mitogen-activated protein kinase pathways in the injured lung tissue. Finally, treatment with Boc2 abolished the protective action of Ac2-26. The results indicated that Ac2-26 had a protective effect against acute lung injury induced by IR, which may be via the activation of the FPR.

Carbonic anhydrase inhibitor attenuates ischemia-reperfusion induced acute lung injury.

Ischemia-reperfusion (IR)-induced acute lung injury (ALI) is implicated in several clinical conditions including lung transplantation, cardiopulmonary bypass surgery, re-expansion of collapsed lung from pneumothorax or pleural effusion and etc. IR-induced ALI remains a challenge in the current treatment. Carbonic anhydrase has important physiological function and influences on transport of CO2. Some investigators suggest that CO2 influences lung injury. Therefore, carbonic anhydrase should have the role in ALI. This study was undertaken to define the effect of a carbonic anhydrase inhibitor, acetazolamide (AZA), in IR-induced ALI, that was conducted in a rat model of isolated-perfused lung with 30 minutes of ischemia and 90 minutes of reperfusion. The animals were divided into six groups (n = 6 per group): sham, sham + AZA 200 mg/kg body weight (BW), IR, IR + AZA 100 mg/kg BW, IR + AZA 200 mg/kg BW and IR+ AZA 400 mg/kg BW. IR caused significant pulmonary micro-vascular hyper-permeability, pulmonary edema, pulmonary hypertension, neutrophilic sequestration, and an increase in the expression of pro-inflammatory cytokines. Increases in carbonic anhydrase expression and perfusate pCO2 levels were noted, while decreased Na-K-ATPase expression was noted after IR. Administration of 200mg/kg BW and 400mg/kg BW AZA significantly suppressed the expression of pro-inflammatory cytokines (TNF-α, IL-1, IL-6 and IL-17) and attenuated IR-induced lung injury, represented by decreases in pulmonary hyper-permeability, pulmonary edema, pulmonary hypertension and neutrophilic sequestration. AZA attenuated IR-induced lung injury, associated with decreases in carbonic anhydrase expression and pCO2 levels, as well as restoration of Na-K-ATPase expression.

Pneumocystis jirovecii pneumonia induced by low-dose methotrexate in a patient with chronic urticaria

Abstract Methotrexate has immunosuppressive effects and is administered for refractory chronic urticaria. We present a case of Pneumocystis jirovecii pneumonia in a patient with refractory chronic urticaria managed by low-dose weekly methotrexate treatment (total cumulative dose 195mg). Our study highlights the importance of providing prompt diagnosis and treatment of Pneumocystis jirovecii pneumonia in patients with chronic urticaria under methotrexate therapy.

Protective Effects of Neural Crest-Derived Stem Cell-Conditioned Media against Ischemia-Reperfusion-Induced Lung Injury in Rats.

Current treatments for ischemia-reperfusion (IR)-induced acute lung injury are limited. Mesenchymal stem cell-conditioned medium (CM) has been reported to attenuate lung injury. Neural crest stem cells (NCSCs), a type of multipotent stem cells, are more easily obtained than mesenchymal stem cells. We hypothesize that NCSC-CM has anti-inflammatory properties that could protect against IR-induced lung injury in rats. In this study, NCSC-CM was derived from rat NCSCs. Typical acute lung injury was induced by 30-min ischemia followed by 90-min reperfusion in adult male Sprague-Dawley rats. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected to analyze the degree of lung injury after the experiment. NCSC-CM was administered before ischemia and after reperfusion. NCSC-CM treatment significantly attenuated IR-induced lung edema, as indicated by decreases in pulmonary vascular permeability, lung weight gain, wet to dry weight ratio, lung weight to body weight ratio, pulmonary arterial pressure, and protein level in BALF. The levels of tumor necrosis factor-α and interleukin-6 in the BALF were also significantly decreased. Additionally, NCSC-CM improved lung pathology and neutrophil infiltration in the lung tissue, and significantly suppressed nuclear factor (NF)-κB activity and IκB-α degradation in the lung. However, heating NCSC-CM eliminated these protective effects. Our experiment demonstrates that NCSC-CM treatment decreases IR-induced acute lung injury and that the protective mechanism may be attributable to the inhibition of NF-κB activation and the inflammatory response. Therefore, NCSC-CM may be a novel approach for treating IR-induced lung injury.

Inhibition of Na-K-Cl cotransporter isoform 1 reduces lung injury induced by ischemia-reperfusion.

OBJECTIVES: Ischemia-reperfusion acute lung injury is characterized by increased vascular permeability, lung edema, and neutrophil sequestration. Ischemia-reperfusion acute lung injury occurs in lung transplantation and other major surgical procedures. Effective regulation of alveolar fluid balance is critical for pulmonary edema. Sodium-potassium-chloride co-transporter regulates alveolar fluid and is associated with inflammation. We hypothesized that sodium-potassium-chloride co-transporter is important in ischemia-reperfusion acute lung injury. Bumetanide, a sodium-potassium-chloride co-transporter inhibitor, is used to treat pulmonary edema clinically. We studied the effect of bumetanide in ischemia-reperfusion acute lung injury. METHODS: Isolated perfusion of mouse lungs in situ was performed. The main pulmonary artery and left atrium were catheterized for lung perfusion and effluent collection for recirculation, respectively, with perfusate consisting of 1 mL blood and 9 mL physiologic solution. Ischemia-reperfusion was induced by 120 minutes of ischemia (no ventilation or perfusion) and reperfused for 60 minutes. Wild-type, SPAK knockout (SPAK-/-), and WNK4 knockin (WNK4D561A/+) mice were divided into control, ischemia-reperfusion, and ischemia-reperfusion + bumetanide groups (n = 6 per group). Bumetanide was administered via perfusate during reperfusion. Measurements were taken of lung wet/dry weight, microvascular permeability, histopathology, cytokine concentrations, and activity of the nuclear factor-κB pathway. RESULTS: In wild-type mice, ischemia-reperfusion caused lung edema (wet/dry weight 6.30 ± 0.36) and hyperpermeability (microvascular permeability, 0.29 ± 0.04), neutrophil sequestration (255.0 ± 55.8 cells/high-power field), increased proinflammatory cytokines, and nuclear factor-κB activation (1.33 ± 0.13). Acute lung injury was more severe in WNK4 mice with more lung edema, permeability, neutrophil sequestration, and nuclear factor-κB activation. Severity of acute lung injury was attenuated in SPAK-/-mice. Bumetanide decreased pulmonary edema (wild-type: wet/dry weight 5.05 ± 0.44, WNK4: wet/dry weight 5.13 ± 0.70), neutrophil sequestration (wild-type: 151.7 ± 27.8 cells/high-power field, WNK4: 135.3 ± 19.1 cells/high-power field), permeability (wild-type: 0.19 ± 0.01, WNK4: 0.21 ± 0.03), cytokines, and nuclear factor-κB activation after ischemia-reperfusion. CONCLUSIONS: Functional reduction of sodium-potassium-chloride co-transporter by genetic or pharmacologic treatment to inhibit sodium-potassium-chloride co-transporter resulted in lower severity of acute lung injury induced by ischemia-reperfusion. Sodium-potassium-chloride co-transporter may present a promising target for therapeutic interventions in a clinical setting.

Anti-Vascular Endothelial Growth Factor Antibody Suppresses ERK and NF-κB Activation in Ischemia-Reperfusion Lung Injury.

Ischemia-reperfusion (IR)-induced acute lung injury (ALI) is implicated in several clinical conditions like lung transplantation, acute pulmonary embolism after thrombolytic therapy, re-expansion of collapsed lung from pneumothorax or pleural effusion, cardiopulmonary bypass and etc. Because mortality remains high despite advanced medical care, prevention and treatment are important clinical issues for IR-induced ALI. Vascular endothelial growth factor (VEGF) has a controversial role in ALI. We therefore conducted this study to determine the effects of anti-VEGF antibody in IR-induced ALI. In the current study, the IR-induced ALI was conducted in a rat model of isolated-perfused lung in situ in the chest. The animals were divided into the control, control + preconditioning anti-VEGF antibody (bevacizumab, 5mg/kg), IR, IR + preconditioning anti-VEGF antibody (1mg/kg), IR+ preconditioning anti-VEGF antibody (5mg/kg) and IR+ post-IR anti-VEGF antibody (5mg/kg) group. There were eight adult male Sprague-Dawley rats in each group. The IR caused significant pulmonary micro-vascular hyper-permeability, pulmonary edema, neutrophilic infiltration in lung tissues, increased tumor necrosis factor-α, and total protein concentrations in bronchoalveolar lavage fluid. VEGF and extracellular signal-regulated kinase (ERK) were increased in IR-induced ALI. Administration of preconditioning anti-VEGF antibody significantly suppressed the VEGF and ERK expressions and attenuated the IR-induced lung injury. This study demonstrates the important role of VEGF in early IR-induced ALI. The beneficial effects of preconditioning anti-VEGF antibody in IR-induced ALI include the attenuation of lung injury, pro-inflammatory cytokines, and neutrophilic infiltration into the lung tissues.

Valproic acid attenuates acute lung injury induced by ischemia-reperfusion in rats.

BACKGROUND: Evidence reveals that histone deacetylase (HDAC) inhibition has potential for the treatment of inflammatory diseases. The protective effect of HDAC inhibition involves multiple mechanisms. Heme oxygenase-1 (HO-1) is protective in lung injury as a key regulator of antioxidant response. The authors examined whether HDAC inhibition provided protection against ischemia-reperfusion (I/R) lung injury in rats by up-regulating HO-1 activity. METHODS: Acute lung injury was induced by producing 40 min of ischemia followed by 60 min of reperfusion in isolated perfused rat lungs. The rats were randomly allotted to control group, I/R group, or I/R + valproic acid (VPA) group with or without an HO-1 activity inhibitor (zinc protoporphyrin IX) (n = 6 per group). RESULTS: I/R caused significant increases in the lung edema, pulmonary arterial pressure, lung injury scores, tumor necrosis factor-α, and cytokine-induced neutrophil chemoattractant-1 concentrations in bronchoalveolar lavage fluid. Malondialdehyde levels, carbonyl contents, and myeloperoxidase-positive cells in lung tissue were also significantly increased. I/R stimulated the degradation of inhibitor of nuclear factor-κB-α, nuclear translocation of nuclear factor-κB, and up-regulation of HO-1 activity. Furthermore, I/R decreased B-cell lymphoma-2, heat shock protein 70, acetylated histone H3 protein expression, and increased the caspase-3 activity in the rat lungs. In contrast, VPA treatment significantly attenuated all the parameters of lung injury, oxidative stress, apoptosis, and inflammation. In addition, VPA treatment also enhanced HO-1 activity. Treatment with zinc protoporphyrin IX blocked the protective effect of VPA. CONCLUSIONS: VPA protected against I/R-induced lung injury. The protective mechanism may be partly due to enhanced HO-1 activity following HDAC inhibition.

Protection against reperfusion lung injury via aborgating multiple signaling cascades by trichostatin A.

Trichostatin A (TSA) is a histone deacetylase inhibitor with anti-inflammatory effects. Nonetheless, little information is available about the effect of TSA in ischemia-reperfusion (IR)-induced lung injury. In a perfused rat lung model, IR was induced by 40min of ischemia followed by 60min of reperfusion. The rat lungs were randomly divided into several groups including control, control+TSA (0.1mg/kg), IR, and IR+various dosages of TSA (0.05, 0.075, 0.1mg/kg). Bronchoalveolar lavage fluids and lung tissues were obtained and examined at the end of the experiment. TSA dose-dependently diminished IR-induced increased vascular permeability and edema, pulmonary artery pressure, and histological changes in the lungs. Additionally, TSA suppressed lavage tumor necrosis factor-α and cytokine-induced neutrophil chemoattractant concentrations, cell infiltration, and myeloperoxidase-positive cells in the lung tissue. Furthermore, TSA attenuated the phosphorylation of extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase, degradation of the inhibitor of nuclear factor (NF)-κB, and nuclear NF-κB levels. TSA also decreased poly (ADP-ribose) polymerase but enhanced acetylated histone H3 acetylation, Bcl-2, and mitogen-activated protein kinase phosphatase-1 (MKP-1) expression in IR lung tissue. Therefore, TSA exerted a protective effect on IR-induced lung injury via increasing histone acetylation and MKP-1 protein expression, repressing NF-κB, mitogen-activated protein kinase, and apoptosis signaling pathways.

Hypercapnic acidosis prolongs survival of skin allografts.

BACKGROUND: Evidence reveals that hypercapnic acidosis (HCA) modulates immune responses. However, the effect of HCA on allogenic skin graft rejection is unknown. We examined whether HCA might improve skin graft survival in a mouse model of skin transplantation. METHODS: A major histocompatibility-complex-incompatible BALB/c to C57BL/6 mouse skin transplantation model was used. Animals were divided into sham control, air, and HCA groups. Mice in the HCA group were exposed daily to 5% CO2 in air for 1 h. Skin grafts were harvested for histologic analyses. Nuclear factor (NF)-κB activation was determined in harvested draining lymph nodes. Spleen weights and serum levels of tumor necrosis factor-α and chemokine (C-X-C motif) ligand 2 were serially assessed after skin transplantation. RESULTS: Skin allografts survived significantly longer in the HCA group of mice than those in the air group. Allografted mice in the air group underwent a 2.1-fold increase in spleen weight compared with a 1.1-fold increase in the mice with HCA on day 3. There were increased inflammatory cell infiltration, folliculitis, focal dermal-epidermal separation, and areas of epidermal necrosis in the air group that were reduced with HCA treatment. In the HCA group, CD8(+) T cell infiltration at day 7 decreased significantly but not CD4(+) T cell infiltration. In addition, HCA significantly suppressed serum tumor necrosis factor-α on days 1 and 3 and chemokine (C-X-C motif) ligand 2 on days 1 and 10. Furthermore, the HCA group had remarkably suppressed NF-κB activity in draining lymph nodes. CONCLUSIONS: HCA significantly prolonged the survival of incompatible skin allografts in mice by reducing proinflammatory cytokine production, immune cell infiltration, and NF-κB activation.