Is Staged Surgery Always Necessary for Schatzker Type IV-VI Tibial Plateau Fractures? A Comparison Study.

AIMS: This study aims to compare the outcomes of immediate (followed by closed-incision negative-pressure therapy use) versus delayed ORIF in patients with Schatzker type IV-VI TPFs. PATIENTS AND METHODS: A prospective study of patients undergoing ORIF between January 2018 and December 2019 was performed. The inclusion criteria were patients (>18 years) with a closed fracture sent to the emergency room (ER) within 24 h of injury. All the patients underwent preoperative image evaluation. Two senior orthopedic trauma surgeons evaluated the soft tissue condition in the ER by 5P's of the compartment syndrome, judging the timing of the operation of definitive ORIF. Group 1 (n = 16) received delayed ORIF. Group 2 (n = 16) received immediate ORIF and ciNPT use. Patient follow-up occurred after 2 and 6 weeks and 3, 6, and 12 months after surgery. The assessments included the time to definitive fixation, the length of hospital stay, the time to bone union, surgical site complications, and reoperation within 12 months. A universal goniometer was used to measure the postoperative 3 m, 6 m, and 12 m ROM. RESULTS: The patient demographics were similar between the groups (p > 0.05). Group 2 displayed significantly a shorter time to definitive fixation (5.94 ± 2.02 vs. 0.61 ± 0.28, p < 0.0001) and hospital stay (14.90 ± 8/78 vs. 10.30 ± 6.78, p = 0.0016). No significant difference was observed in the time to bone union, surgical site complication incidence, and reoperation rates (p > 0.05). Flexion and flexion-extension knee ROM were demonstrated to be significantly improved in Group 2, 3, 6, and 12 months postoperatively (p < 0.0001). CONCLUSIONS: In this study, early ORIF and ciNPT use resulted in a shorter hospital length of stay, a reduced time to early active motion of the knee, and improved knee ROM. These results suggest that early ORIF with ciNPT for Schatzker type IV-VI TPFs is safe and effective in some patients. However, further research to confirm these findings across larger and more diverse populations is needed.

Changes in Levels of Serum Cytokines and Chemokines in Perforated Appendicitis in Children.

Appendicitis is primarily diagnosed based on intraoperative or histopathological findings, and few studies have explored pre-operative markers of a perforated appendix. This study aimed to identify systemic biomarkers to predict pediatric appendicitis at various time points. The study group comprised pediatric patients with clinically suspected appendicitis between 2016 and 2019. Pre-surgical serum interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), intercellular cell-adhesion molecule-1 (ICAM-1), and endothelial selectin (E-selectin) levels were tested from day 1 to day 3 of the disease course. The biomarker values were analyzed and compared between children with normal appendices and appendicitis and those with perforated appendicitis (PA) and non-perforated appendicitis. Among 226 pediatric patients, 106 had non-perforated appendicitis, 102 had PA, and 18 had normal appendices. The levels of all serum proinflammatory biomarkers were elevated in children with acute appendicitis compared with those in children with normal appendices. In addition, the serum IL-6 and TNF-α levels in children with PA were significantly higher, with an elevation in TNF-α levels from days 1 and 2. In addition, serum IL-6 levels increased significantly from days 2 and 3 (both p < 0.05). Serum ICAM-1 and E-selectin levels were elevated in the PA group, with consistently elevated levels within the first three days of admission (all p < 0.05). These results indicate that increased serum levels of proinflammatory biomarkers including IL-6, TNF-α, ICAM-1, and E-selectin could be used as parameters in the prediction and early diagnosis of acute appendicitis, especially in children with PA.

Effects of mitral valve disease etiology on the outcomes of mechanical and biological valve replacement: retrospective cohort study.

INTRODUCTION: The choice of an artificial mitral valve (MV) is a crucial clinical decision that affects the long-term survival and quality of life of patients. However, current guidelines recommend selecting MV based on patient age and life expectancy at the time of mitral valve replacement (MVR), without considering the etiology of MV disease. This study aimed to investigate whether MV disease etiology should be considered when choosing a valve for MVR and to evaluate the impact of MV disease etiology on long-term patient survival. METHODS: Using data (2002-2018) from Taiwan's National Health Insurance Research Database, the authors conducted a nationwide retrospective cohort study to compare the biological and mechanical valves in terms of all-cause mortality as the primary outcome. The inverse probability of the treatment weighting method was used to reduce the effects of the confounding factors. The following etiologies were assessed: infective endocarditis, rheumatic heart disease, ischemic mitral regurgitation, and degenerative mitral regurgitation. RESULTS: In patients aged below 70 years, it was observed that mechanical valves demonstrated an association with benefits compared to biological valves in the context of survival. In patients with infective endocarditis aged below 72 years, mechanical valves were associated with survival benefits, but not in those with stroke during hospitalization. These valves were also found to be linked with survival advantages for patients with rheumatic heart disease aged below 60 years and for those with degenerative mitral regurgitation aged below 72 years. However, no age-dependent effects of valve type on all-cause mortality were observed in patients with ischemic mitral regurgitation. CONCLUSION: The etiology of MV disease appears to be important in the selection of a suitable MV and determination of a cutoff age for mechanical and biological MVR.

Trabectedin Enhances Oncolytic Virotherapy by Reducing Barriers to Virus Spread and Cytotoxic Immunity in Preclinical Pediatric Bone Sarcoma.

We previously reported that the DNA alkylator and transcriptional-blocking chemotherapeutic agent trabectedin enhances oncolytic herpes simplex viroimmunotherapy in human sarcoma xenograft models, though the mechanism remained to be elucidated. Here we report trabectedin disrupts the intrinsic cellular anti-viral response which increases viral transcript spread throughout the human tumor cells. We also extended our synergy findings to syngeneic murine sarcoma models, which are poorly susceptible to virus infection. In the absence of robust virus replication, we found trabectedin enhanced viroimmunotherapy efficacy by reducing immunosuppressive macrophages and stimulating granzyme expression in infiltrating T and NK cells to cause immune-mediated tumor regressions. Thus, trabectedin enhances both the direct virus-mediated killing of tumor cells and the viral-induced activation of cytotoxic effector lymphocytes to cause tumor regressions across models. Our data provide a strong rationale for clinical translation as both mechanisms should be simultaneously active in human patients.

Treatment of Undifferentiated Embryonal Sarcoma of the Liver in Children.

Undifferentiated embryonal sarcoma of the liver is a rare mesenchymal tumor with a highly malignant potential. It occurs almost exclusively in the pediatric population and typically has a poor outcome. Although previous studies have reported dismal prognoses, recent advances in combined treatment modalities, e.g., surgery and chemotherapy, have given cause for optimism. Even in those diseases not amenable to complete surgical resection or refractory diseases, other treatment modalities, such as liver transplant, have yielded promising results. This paper provides a review of the current treatment modalities for hepatic undifferentiated embryonal sarcoma in children.

The Modulation of Phospho-Extracellular Signal-Regulated Kinase and Phospho-Protein Kinase B Signaling Pathways plus Activity of Macrophage-Stimulating Protein Contribute to the Protective Effect of Stachydrine on Acetaminophen-Induced Liver Injury.

Stachydrine, a prominent bioactive alkaloid derived from Leonurus heterophyllus, is a significant herb in traditional medicine. It has been noted for its anti-inflammatory and antioxidant characteristics. Consequently, we conducted a study of its hepatoprotective effect and the fundamental mechanisms involved in acetaminophen (APAP)-induced liver injury, utilizing a mouse model. Mice were intraperitoneally administered a hepatotoxic dose of APAP (300 mg/kg). Thirty minutes after APAP administration, mice were treated with different concentrations of stachydrine (0, 2.5, 5, and 10 mg/kg). Animals were sacrificed 16 h after APAP injection for serum and liver tissue assays. APAP overdose significantly elevated the serum alanine transferase levels, hepatic pro-inflammatory cytokines, malondialdehyde activity, phospho-extracellular signal-regulated kinase (ERK), phospho-protein kinase B (AKT), and macrophage-stimulating protein expression. Stachydrine treatment significantly decreased these parameters in mice with APAP-induced liver damage. Our results suggest that stachydrine may be a promising beneficial target in the prevention of APAP-induced liver damage through attenuation of the inflammatory response, inhibition of the ERK and AKT pathways, and expression of macrophage-stimulating proteins.

Sex Differences in Epidemiological Distribution and Outcomes of Surgical Mitral Valve Disease.

BACKGROUND: Mitral valve (MV) disease is the most common form of valvular heart disease. Findings that indicate women have a higher risk for unfavorable outcomes than men remain controversial. This study aimed to determine the sex-based differences in epidemiological distributions and outcomes of surgery for MV disease.Methods and Results: Overall, 18,572 patients (45.3% women) who underwent MV surgery between 2001 and 2018 were included. Outcomes included in-hospital death and all-cause mortality during follow up. Subgroup analysis was conducted across different etiologies, including infective endocarditis (IE), degenerative, ischemic, and rheumatic mitral pathology. The overall MV repair rate was lower in women than in men (20.5% vs. 30.6%). After matching, 6,362 pairs (woman : man=1 : 1) of patients were analyzed. Women had a slightly higher risk for in-hospital death than men (10.8% vs. 9.8%; odds ratio [OR]: 1.11, 95% confidence interval [CI]: 0.99-1.24; P=0.075). Women tended to have a higher incidence of de novo dialysis (9.8% vs. 8.6%; P=0.022) and longer intensive care unit stay (8 days vs. 7.1 days; P<0.001). Women with IE had poorer in-hospital outcomes than men; however, there were no sex differences in terms of all-cause mortality. CONCLUSIONS: Sex-based differences of MV intervention still persist. Although long-term outcomes were comparable between sexes, women, especially those with IE, had worse perioperative outcomes than men.

Mitral Valve Repair vs. Replacement by Different Etiologies　- A Nationwide Population-Based Cohort Study.

BACKGROUND: When mitral valve (MV) surgery is indicated, repair is preferred over replacement; however, this preference is not supported by evidence from clinical trials. Furthermore, the benefits of MV repair may not be universal for all etiologies of MV disease.Methods and Results: This study identified a total of 18,428 patients who underwent MV repair (n=4,817) or MV replacement (n=13,611) during 2001-2018 from Taiwan's National Health Insurance Research Database. These patients were classified into 4 etiologies: infective endocarditis (IE, n=2,678), rheumatic heart disease (RHD, n=4,524), ischemic mitral regurgitation (IMR, n=3,893), and degenerative mitral regurgitation (DMR, n=7,333). After propensity matching, all-cause mortality during follow-up was lower among patients receiving MV repair than among patients receiving MV replacement in the IE, IMR, and DMR groups (hazard ratio [HR]=0.72, 95% confidence interval [CI]: 0.55-0.93; HR=0.82, 95% CI: 0.73-0.92; and HR 0.73, 95% CI: 0.64-0.84, respectively). However, in the RHD group, the MV reoperation rate was higher after MV repair than after MV replacement (subdistribution HR=1.91, 95% CI: 1.02-3.55). CONCLUSIONS: In comparison with MV replacement, MV repair was associated with a lower late mortality in patients with IE, IMR, and DMR, and a higher risk of reoperation in patients with RHD.

Mechanical Versus Bioprosthetic Aortic Valve Replacement in Patients Undergoing Bentall Procedure.

BACKGROUND: The widely used Bentall procedure is the criterion standard treatment for aortic root pathology. Studies comparing the long-term outcomes of bioprosthetic and mechanical valves in patients undergoing the Bentall procedure are limited. METHODS AND RESULTS: Patients who underwent the Bentall procedure with a bioprosthetic or mechanical valve between 2001 and 2018 were identified from Taiwan's National Health Insurance Research Database. The primary outcome of interest was all-cause mortality. Inverse probability of treatment weighting was performed to compare the 2 prosthetic types. In total, 1052 patients who underwent the Bentall procedure were identified. Among these patients, 351 (33.4%) and 701 (66.6%) chose bioprosthetic and mechanical valves, respectively. After inverse probability of treatment weighting, no significant differences in the in-hospital mortality (odds ratio, 0.96 [95% CI, 0.77-1.19]; P=0.716) and all-cause mortality (34.1% vs. 38.1%; hazard ratio, 0.90 [95% CI, 0.78-1.04]; P=0.154) were observed between the groups. The benefits of relative mortality associated with mechanical valves were apparent in younger patients and persisted until ≈50 years of age. CONCLUSIONS: No differences in survival benefits were observed between the valves in patients who underwent the Bentall procedure. Additionally, bioprosthetic valves may be a reasonable choice for patients aged >50 years when receiving the Bentall procedure in this valve-in-valve era.

Stem Cell Therapy in Children with Traumatic Brain Injury.

Pediatric traumatic brain injury is a cause of major mortality, and resultant neurological sequelae areassociated with long-term morbidity. Increasing studies have revealed stem cell therapy to be a potential new treatment. However, much work is still required to clarify the mechanism of action of effective stem cell therapy, type of stem cell therapy, optimal timing of therapy initiation, combination of cocurrent medical treatment and patient selection criteria. This paper will focus on stem cell therapy in children with traumatic brain injury.

Mesenchymal Stem Cells in the Treatment of COVID-19.

Since the emergence of the coronavirus disease 2019 (COVID-19) pandemic, many lives have been tragically lost to severe infections. The COVID-19 impact extends beyond the respiratory system, affecting various organs and functions. In severe cases, it can progress to acute respiratory distress syndrome (ARDS) and multi-organ failure, often fueled by an excessive immune response known as a cytokine storm. Mesenchymal stem cells (MSCs) have considerable potential because they can mitigate inflammation, modulate immune responses, and promote tissue regeneration. Accumulating evidence underscores the efficacy and safety of MSCs in treating severe COVID-19 and ARDS. Nonetheless, critical aspects, such as optimal routes of MSC administration, appropriate dosage, treatment intervals, management of extrapulmonary complications, and potential pediatric applications, warrant further exploration. These research avenues hold promise for enriching our understanding and refining the application of MSCs in confronting the multifaceted challenges posed by COVID-19.

Oncolytic virus-driven immune remodeling revealed in mouse medulloblastomas at single cell resolution.

Oncolytic viruses, modified for tumor-restricted infection, are a promising cancer immunotherapeutic, yet much remains to be understood about factors driving their activity and outcome in the tumor microenvironment. Here, we report that oncolytic herpes simplex virus C134, previously found to exert T cell-dependent efficacy in mouse models of glioblastoma, exerts T cell-independent efficacy in mouse models of medulloblastoma, indicating this oncolytic virus uses different mechanisms in different tumors. We investigated C134's behavior in mouse medulloblastomas, using single cell RNA sequencing to map C134-induced gene expression changes across cell types, timepoints, and medulloblastoma subgroup models at whole-transcriptome resolution. Our work details substantial oncolytic virus-induced transcriptional remodeling of medulloblastoma-infiltrating immune cells, 10 subpopulations of monocytes and macrophages collectively demonstrating M1-like responses to C134, and suggests C134 be investigated as a potential new therapy for medulloblastoma.

Comparison of primary total hip arthroplasty with limited open reduction and internal fixation vs open reduction and internal fixation for geriatric acetabular fractures: a systematic review and meta-analysis.

Purpose: Comminuted fractures with poor bone quality in the elderly are associated with poor outcomes. An alternative to open reduction and internal fixation (ORIF) alone, primary or acute total hip arthroplasty (aTHA), allows early mobilization with full weight bearing. In this study, we aim to analyze whether treatment of aTHA with/withtout ORIF (limited ORIF) vs ORIF alone yields better intra-operative results, functional outcomes, and less complications. Methods: PubMed, Cochrane, Embase, and Scopus databases were searched in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Random-effects model and 95% confidence intervals were used. The outcomes of interest were surgery time, blood loss, length of hospital stay, Harris hip score (HHS), 36-Item Short Form Survey (SF-36), complication rate, surgical site infection rate, heterotopic ossification rate, reoperation rate, and mortality rate. Results: Ten observational studies with a total of 642 patients (415 ORIF alone and 227 aTHA with/without ORIF) were included in the systematic review. Compared to ORIF alone, aTHA with limited ORIF provided higher HHS (P = 0.029), better physical function (P = 0.008), better physical component summary (P = 0.001), better mental component summary (P = 0.043) in postoperative 1-year SF-36, lesser complication rate (P = 0.001), and lesser reoperation rate (P = 0.000), but however greater bodily pain (P = 0.001) in acetabular fractured elderlies. Conclusions: Acute THA with limited ORIF is favorable alternative to ORIF technique alone. It provided better HHS, physical, and mental component summary in SF-36 and yielded lower complication and reoperation rate compare to ORIF alone.

Amyloid modifier SERF1a interacts with polyQ-expanded huntingtin-exon 1 via helical interactions and exacerbates polyQ-induced toxicity.

Abnormal polyglutamine (polyQ) expansion and fibrillization occur in Huntington's disease (HD). Amyloid modifier SERF enhances amyloid formation, but the underlying mechanism is not revealed. Here, the fibrillization and toxicity effect of SERF1a on Htt-exon1 are examined. SERF1a enhances the fibrillization of and interacts with mutant thioredoxin (Trx)-fused Httex1. NMR studies with Htt peptides show that TrxHttex1-39Q interacts with the helical regions in SERF1a and SERF1a preferentially interacts with the N-terminal 17 residues of Htt. Time-course analysis shows that SERF1a induces mutant TrxHttex1 to a single conformation enriched of ß-sheet. Co-expression of SERF1a and Httex1-polyQ in neuroblastoma and lentiviral infection of SERF1a in HD-induced polypotent stem cell (iPSC)-derived neurons demonstrates the detrimental effect of SERF1a in HD. Higher level of SERF1a transcript or protein is detected in HD iPSC, transgenic mice, and HD plasma. Overall, this study provides molecular mechanism for SERF1a and mutant Httex1 to facilitate therapeutic development for HD.

Durability of Biological Valves Implanted in Aortic or Mitral Positions: A Nationwide Cohort Study.

BACKGROUND: Biologic prostheses are being increasingly used for aortic and mitral valve replacement (AVR and MVR). This study evaluated the long-term durability of bioprosthetic valves in the mitral and aortic positions, as no well-designed population-based studies have addressed this issue before. METHODS: Using Taiwan's National Health Insurance Research Database, we compared biologic valve durability in the mitral and aortic positions in patients hospitalized between 2001 and 2017, with reoperation as the primary outcome. Both between-subject and within-subject designs were used, and the propensity score matching cohort (1:1 ratio) was created for the former. RESULTS: We identified a total of 10,308 patients, 5462 of whom received AVR, 3901 received MVR, and 945 received double valve replacement. Both AVR and MVR cohorts had 2259 patients after matching. During a mean follow-up of 4.2 years (range, 1 day to 17.9 years), the reoperation rate in the MVR cohort (3.5%) was higher than that in the AVR cohort (2.6%) (hazard ratio 1.41; 95% CI, 1.01-1.98). A higher risk of all-cause death was observed in the MVR cohort (36.5%) than in the AVR cohort (32.6%) (hazard ratio 1.21; 95% CI, 1.10-1.34). Among patients receiving double valve replacement with the same prosthesis type, valves implanted in the aortic position were considerably less likely to require reimplantation. CONCLUSIONS: Bioprosthetic valve placement in the aortic position is associated with superior outcomes in terms of durability, long-term mortality, and perioperative morbidity. Developing novel interventions and enhancing valve durability would expand bioprosthesis use for valve replacement.

Opportunities and challenges of combining adoptive cellular therapy with oncolytic virotherapy.

The use of oncolytic viruses (OVs) and adoptive cell therapies (ACT) have independently emerged as promising approaches for cancer immunotherapy. More recently, the combination of such agents to obtain a synergistic anticancer effect has gained attention, particularly in solid tumors, where immune-suppressive barriers of the microenvironment remain a challenge for desirable therapeutic efficacy. While adoptive cell monotherapies may be restricted by an immunologically cold or suppressive tumor microenvironment (TME), OVs can serve to prime the TME by eliciting a wave of cancer-specific immunogenic cell death and inducing enhanced antitumor immunity. While OV/ACT synergy is an attractive approach, immune-suppressive barriers remain, and methods should be considered to optimize approaches for such combination therapy. In this review, we summarize current approaches that aim to overcome these barriers to enable optimal synergistic antitumor effects.

Rupture of finger distal interphalangeal collateral ligament treated with a mini soft anchor.

BACKGROUND: Ruptured finger distal interphalangeal (DIP) collateral ligament is a rare injury, with controversial treatment until the present. Our case series aimed to demonstrate feasible surgical intervention using a mini anchor. METHODS: The present study includes four patients with ruptured finger DIP collateral ligaments who received primary repair in a single institute. They have suffered from joint instability due to ligament loss caused by infection, motorcycle accidents, and work-related accidents. All patients were operated on similarly using a 1.0 mm mini anchor for ligament reattachment. RESULTS: The finger DIP joint range of motion (ROM) was documented in all patients during follow-up. Joint ROM recovered to almost normal degrees, and the pinch strength recovered to > 90% compared to the contralateral side in all patients. Additionally, collateral ligament re-rupture, DIP joint subluxation or re-dislocation, and infection were not noted during follow-up. CONCLUSIONS: Ruptured finger DIP joint ligament requiring surgery is usually based on a combination with other soft tissue injuries and defects. However, repair with a 1.0 mm mini anchor is a feasible surgical intervention to reattach the ligament with minimal complication.

Urinary microRNA in Diabetic Kidney Disease: A Literature Review.

Diabetic kidney disease is the most common primary disease of end-stage kidney disease globally; however, a sensitive and accurate biomarker to predict this disease remains awaited. microRNAs are endogenous single-stranded noncoding RNAs that have intervened in different post-transcriptional regulations of various cellular biological functions. Previous literatures have reported its potential role in the pathophysiology of diabetic kidney disease, including regulation of Transforming Growth Factor-ß1-mediated fibrosis, extracellular matrix and cell adhesion proteins, cellular hypertrophy, growth factor, cytokine production, and redox system activation. Urinary microRNAs have emerged as a novel, non-invasive liquid biopsy for disease diagnosis. In this review, we describe the available experimental and clinical evidence of urinary microRNA in the context of diabetic kidney disease and discuss the future application of microRNA in routine practice.

Fermented jellyfish (Rhopilema esculentum) collagen enhances antioxidant activity and cartilage protection on surgically induced osteoarthritis in obese rats.

Collagen has been considered a key treatment option in preventing damage to the articular cartilage over time and supporting the healing process, following the onset of osteoarthritis (OA). This study aimed to investigate the effect of collagen fermented from jellyfish (FJC) by Bacillus subtilis natto on anterior cruciate ligament transection with medial meniscectomy (ACLT + MMx)-induced knee OA in high-fat diet (HFD)-induced obesity in rats. The male Sprague-Dawley rats were fed an HFD for 6 weeks before ACLT + MMx surgery, after which they were administered a daily oral gavage of saline (control, OA, and OBOA), either with FJC (20 mg/kg, 40 mg/kg, and 100 mg/kg body weight) or glucosamine sulfate as a positive control (GS; 200 mg/kg body weight) for 6 weeks. Treatment with FJC decreased the fat weight, triglyceride, and total cholesterol levels in obese rats. Additionally, FJC downregulated the expression of some proinflammatory cytokines, including tumor necrosis factor-α, cyclooxygenase-2, and nitric oxide; suppressed leptin and adiponectin expression; and attenuated cartilage degradation. It also decreased the activities of matrix metalloproteinase (MMP)-1 and MMP-3. These results demonstrated that FJC showed a protective effect on articular cartilage and also suppressed the degradation of cartilage in an animal OA model, suggesting its potential efficacy as a promising candidate for OA treatment.

Apremilast ameliorates acute respiratory distress syndrome by inhibiting neutrophil-induced oxidative stress.

BACKGROUND: The pathogenesis of acute respiratory distress syndrome (ARDS) is attributed to the dysregulation of oxidative stress and neutrophil recruitment. We aimed to investigate the anti-inflammatory effects of apremilast on human neutrophils and assess its efficacy for treating ARDS. METHODS: We analysed superoxide anion generation, integrin expression, and adhesion in activated human neutrophils using spectrophotometry, flow cytometry, and immunofluorescence microscopy. Phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was determined using immunoblotting. A murine lipopolysaccharide (LPS)-induced ARDS model was used to evaluate the therapeutic effects of apremilast. RESULTS: Apremilast significantly decreased superoxide anion production, reactive oxygen species (ROS) generation, cluster of differentiation (CD)11 b expression, and neutrophil adhesion in formyl-l-methionyl-l-leucyl-l-phenylalanine activated human neutrophils. Apremilast elevated cyclic 3',5'-adenosine monophosphate (cAMP) and protein kinase A (PKA) activity in activated neutrophils. It reduced cellular cAMP-specific phosphodiesterase (PDE) activity and selectively inhibited enzymatic PDE4 activity. The activated cAMP/PKA pathway suppressed the phosphorylation of ERK and JNK as well as Ca2+ mobilization in activated neutrophils. All inhibitory effects of apremilast on activated neutrophils were reversed by a PKA inhibitor. In vivo examinations indicated that apremilast alleviated lung neutrophil infiltration, myeloperoxidase (MPO) activity, pulmonary oedema, and alveolar damage in LPS-induced ARDS. CONCLUSION: Apremilast inhibits inflammatory responses after neutrophil activation via cAMP/PKA-dependent inhibition of ERK and JNK activation. Our study revealed apremilast suppresses oxidative stress and chemotaxis by selectively inhibiting PDE4 in neutrophils and thus protects against endotoxin-induced ARDS in mice. Apremilast can be used as an alternative off-label drug in treating acute lung damage.