Design and comprehensive characterization of dry powder inhalation aerosols of simvastatin DPPC/DPPG lung surfactant-mimic nanoparticles/microparticles for pulmonary nanomedicine.

The Rho Kinase (ROCK) pathway is recognized to be involved in changes that lead to remodeling in pulmonary hypertension (PH), particularly cellular processes including signaling, contraction, migration, proliferation, differentiation, and apoptosis. Simvastatin (Sim) has a potent anti-proliferative and pro-apoptotic effect on vasculature smooth muscle cells through the inhibition of the synthesis of isoprenoids intermediates which are essential for the post-translational isoprenylation of Rho, Rac, and Ras family GTPases. Sim targets the underlying mechanism in vascular remodeling. Using bionanomaterials and particle engineering design, this innovative study reports on the advanced inhalable dry powders composed of sim with synthetic phospholipid bionanomaterials, DPPC/DPPG, as a lung surfactant-mimic. These were successfully designed and produced as co-spray dried (Co-SD) nanoparticles and microparticles for nanomedicine delivery as dry powder inhalers (DPIs). Different techniques were used to comprehensively characterize the physicochemical properties of the resulting Co-SD particles. The Next Generation ImpactorTM (NGI™) was used with three different FDA-approved human DPI devices with varying shear stress which were the HandiHaler®, Neohaler®, Aerolizer® DPI devices for aerosol dispersion performance. The formulation-device interactions were examined and correlated. Using human lung cells from different lung regions, in vitro cell viability and transepithelial electrical resistance (TEER) at the air-liquid interface showed biocompatibility of the formulations as a function of dose.

Novel Mechanism of Cyclic Nucleotide Crosstalk Mediated by PKG-dependent Proteasomal Degradation of the Hsp90 Client Protein Phosphodiesterase 3A.

Endothelial cAMP-specific phosphodiesterase PDE3A is one of the major negative regulators of the endothelial barrier function in acute lung injury (ALI) models. However, the mechanisms underlying its regulation still need to be fully resolved. We show here that the PDE3A is a newly described client of the molecular chaperone hsp90. In endothelial cells (EC), hsp90 inhibition by geldanamycin (GA) led to a disruption of the hsp90/PDE3A complex, followed by a significant decrease in PDE3A protein levels. The decrease in PDE3A protein levels was ubiquitin-proteasome-dependent and required the activity of the E3 ubiquitin ligase C-terminus of Hsc70-interacting protein (CHIP). GA treatment also enhanced the association of PDE3A with hsp70, which partially prevented PDE3A degradation. GA-induced decreases in PDE3A protein levels correlated with decreased PDE3 activity and increased cAMP levels in EC. We also demonstrated that PKG-dependent phosphorylation of PDE3A at Ser654 can signal the dissociation of PDE3A from hsp90 and PDE3A degradation. This was confirmed by endogenous PDE3A phosphorylation and degradation in 8-Br-cGMP- or 8-CPT-cGMP- and Bay 41-8543 -stimulated EC and comparisons of wildtype- and phospho-mimic S654D mutant PDE3A protein stability in transiently transfected HEK293 cells. In conclusion, we have identified a new mechanism of PDE3A regulation mediated by the ubiquitin-proteasome system. Further, the degradation of PDE3A is controlled by the phosphorylation of S654 and the interaction with hsp90. We speculate that targeting the PDE3A/hsp90 complex could be a therapeutic approach for ALI.

MicroRNA mediated suppression of airway lactoperoxidase by TGF-ß1 and cigarette smoke promotes airway inflammation.

Transforming Growth Factor Beta1 (TGF-ß1) signaling is upregulated in Chronic Obstructive Pulmonary disease (COPD), smokers, and people living with HIV. Cigarette smoking and HIV are also independent risk factors for COPD. Chronic inflammation is a hallmark of COPD. However, the underlying mechanisms remain unknown. Previous research has suggested that TGF-ß1 alters the airway epithelial microRNAome and transcriptome, potentially contributing to lung inflammation. The Lactoperoxidase (LPO) system is an integral component of innate immunity within the airway. LPO plays a crucial role in host defense by catalyzing the oxidation of thiocyanate to hypothiocyanite in the presence of hydrogen peroxide (H2O2), generating a potent antibacterial and antiviral agent. Additionally, the LPO system potentially aids in maintaining cellular redox balance by reducing the levels of H2O2, thus mitigating oxidative stress within the airway epithelium. LPO dysfunction can impair immune responses and exacerbate inflammatory processes in respiratory diseases.In this study, primary bronchial epithelial cells and bronchial cell lines were treated with TGF-ß1 and exposed to cigarette smoke to characterize the effect of these factors on LPO and their downstream effects. RT-qPCR and Western Blot were applied to quantify mRNA and proteins' expression. The levels of H2O2 were detected using the Amplex Red Assay. Magnetofection and transfection were applied to probe the effect of miR-449b-5p. Staining procedures using the MitoTracker Green and C12FDG dyes were used to establish mitochondria mass and senescence. The levels of pro-inflammatory cytokines were measured via Luminex assays.We found that TGF-ß1 and cigarette smoke suppressed airway LPO expression, increasing H2O2 levels. This increase in H2O2 had downstream effects on mitochondrial homeostasis, epithelial cellular senescence, and the pro-inflammatory cytokine response. We demonstrate for the first time that airway LPO is regulated by TGF-ß1-induced miRNA-mediated post-transcriptional silencing through miR-449b-5p in the lungs. Further, we identify and validate miR-449-5p as the candidate miRNA upregulated by TGF-ß1, which is involved in LPO suppression. This paper demonstrates a new mechanism by which TGF-ß1 can lead to altered redox status in the airway.

Altered Host microRNAomics in HIV Infections: Therapeutic Potentials and Limitations.

microRNAs have emerged as essential regulators of health and disease, attracting significant attention from researchers across diverse disciplines. Following their identification as noncoding oligonucleotides intricately involved in post-transcriptional regulation of protein expression, extensive efforts were devoted to elucidating and validating their roles in fundamental metabolic pathways and multiple pathologies. Viral infections are significant modifiers of the host microRNAome. Specifically, the Human Immunodeficiency Virus (HIV), which affects approximately 39 million people worldwide and has no definitive cure, was reported to induce significant changes in host cell miRNA profiles. Identifying and understanding the effects of the aberrant microRNAome holds potential for early detection and therapeutic designs. This review presents a comprehensive overview of the impact of HIV on host microRNAome. We aim to review the cause-and-effect relationship between the HIV-induced aberrant microRNAome that underscores miRNA's therapeutic potential and acknowledge its limitations.

A Systematic Review and Meta-analysis of 24 Month Patency After Endovenous Stenting of Superior Vena Cava, Subclavian, and Brachiocephalic Vein Stenosis.

OBJECTIVE: This systematic review and meta-analysis aimed to appraise recent evidence assessing patency outcomes at various time points in patients with superior vena cava, subclavian, and brachiocephalic vein stenosis who had undergone stenting. DATA SOURCES: PubMed, Scopus, and Cochrane Library databases were searched for studies up to December 2022. REVIEW METHODS: Measured outcomes included technical success rate, primary, primary assisted, and secondary patency at various time points. A subgroup analysis was also conducted to compare malignant and benign obstruction. GRADE was used to assess the certainty of evidence. RESULTS: Thirty nine studies reporting outcomes in 1 539 patients were included in the meta-analysis. Primary patency up to one year after the procedure was 81.5% (95% CI 74.5 - 86.9%). Primary patency declined after one year to 63.2% (95% CI 51.9 - 73.1%) at 12 - 24 months. Primary assisted patency and secondary patency at ≥ 24 months were 72.7% (95% CI 49.1 - 88.0%) and 76.6% (95% CI 51.1 - 91.1%). In the subgroup analysis, primary patency was significantly higher in patients with a malignant stenosis compared with a benign stenosis at 1 - 3 and 12 - 24 months. No significant difference was seen for pooled secondary patency rates when comparing the malignant and benign subgroups. GRADE analysis determined the certainty of evidence for all outcomes to be very low. CONCLUSION: Stenting is an effective intervention for benign and malignant stenosis of the superior vena cava, subclavian, and brachiocephalic veins. Primary patency rates were good up to one year after the procedure, with 81.5% of stents retaining patency at 6 - 12 months. Patency rates declined after one year, to 63.2% primary and 89.3% secondary patency at 12 - 24 months, showing improved outcomes following re-intervention. High quality evidence is lacking. More research is needed to investigate patency outcomes and the need for surveillance or re-intervention programs.

Fatigue Test Method to Evaluate the 50 Year Durability of Venous Stents.

OBJECTIVE: Iliofemoral venous obstructive disease can result in significant, potentially debilitating symptoms that can negatively affect quality of life. Unlike arterial disease, patients with deep venous disease have a significantly lower median age, therefore the need for long term stent patency becomes a matter of decades rather than years. Furthermore, iliofemoral lesions frequently require stent placement across the inguinal ligament. Such stents are subject to dynamic stress from leg movement and associated concerns for device fatigue, resulting in stent fracture. The aim of this study was to describe an in vitro 50 year stent fatigue test method designed to assess durability against dynamic stress induced device fracture. METHODS: Through literature review, cadaver studies, and computer modelling, the most challenging loading was confirmed to be hip flexion across the inguinal ligament. This occurs when the patient adjusts between a seated and standing position. Sit to stand hip flexion at the inguinal ligament was effectively simulated on the bench in this in vitro experimental study. RESULTS: When tested under challenge parameters, hip flexion was reliably found to cause fractures in non-venous nitinol stents. However, a dedicated self expanding nitinol venous stent, engineered for improved durability, underwent up to 50 years of simulated loading on the bench with 15% (3/20) of stents experiencing fractures at 50 years, compared with fractures in 35% (14/40) of non-venous stents tested to 1.4 years; no statistical testing was performed as durations do not match and the objective was to demonstrate the test method. CONCLUSION: The presented fatigue test method is a suitable approach for evaluating the durability of stents intended for venous use. Venous stents demonstrated superior fatigue resistance compared with non-venous stents via in vitro hip flexion testing.

Inflammatory lung injury is associated with endothelial cell mitochondrial fission and requires the nitration of RhoA and cytoskeletal remodeling.

Higher levels of extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a TLR4 agonist, are associated with poor clinical outcomes in sepsis-induced acute lung injury (ALI). Little is known regarding the mechanisms by which eNAMPT is involved in ALI. Our recent work has identified a crucial role for mitochondrial dysfunction in ALI. Thus, this study aimed to determine if eNAMPT-mediated inflammatory injury is associated with the loss of mitochondrial function. Our data show that eNAMPT disrupted mitochondrial bioenergetics. This was associated with cytoskeleton remodeling and the loss of endothelial barrier integrity. These changes were associated with enhanced mitochondrial fission and blocked when Rho-kinase (ROCK) was inhibited. The increases in mitochondrial fission were also associated with the nitration-mediated activation of the small GTPase activator of ROCK, RhoA. Blocking RhoA nitration decreased eNAMPT-mediated mitochondrial fission and endothelial barrier dysfunction. The increase in fission was linked to a RhoA-ROCK mediated increase in Drp1 (dynamin-related protein 1) at serine(S)616. Another TLR4 agonist, lipopolysaccharide (LPS), also increased mitochondrial fission in a Drp1 and RhoA-ROCK-dependent manner. To validate our findings in vivo, we challenged C57BL/6 mice with eNAMPT in the presence and absence of the Drp1 inhibitor, Mdivi-1. Mdivi-1 treatment protected against eNAMPT-induced lung inflammation, edema, and lung injury. These studies demonstrate that mitochondrial fission-dependent disruption of mitochondrial function is essential in TLR4-mediated inflammatory lung injury and identify a key role for RhoA-ROCK signaling. Reducing mitochondrial fission could be a potential therapeutic strategy to improve ARDS outcomes.

Free Radical-Associated Gene Signature Predicts Survival in Sepsis Patients.

Sepsis continues to overwhelm hospital systems with its high mortality rate and prevalence. A strategy to reduce the strain of sepsis on hospital systems is to develop a diagnostic/prognostic measure that identifies patients who are more susceptible to septic death. Current biomarkers fail to achieve this outcome, as they only have moderate diagnostic power and limited prognostic capabilities. Sepsis disrupts a multitude of pathways in many different organ systems, making the identification of a single powerful biomarker difficult to achieve. However, a common feature of many of these perturbed pathways is the increased generation of reactive oxygen species (ROS), which can alter gene expression, changes in which may precede the clinical manifestation of severe sepsis. Therefore, the aim of this study was to evaluate whether ROS-related circulating molecular signature can be used as a tool to predict sepsis survival. Here we created a ROS-related gene signature and used two Gene Expression Omnibus datasets from whole blood samples of septic patients to generate a 37-gene molecular signature that can predict survival of sepsis patients. Our results indicate that peripheral blood gene expression data can be used to predict the survival of sepsis patients by assessing the gene expression pattern of free radical-associated -related genes in patients, warranting further exploration.

Single-session mechanical thrombectomy for iliofemoral deep vein thrombosis using a dual mechanism of action device combining basket and rotational thrombectomy.

OBJECTIVE: Interventional treatments for acute iliofemoral deep vein thrombosis (DVT) remain controversial after publication of the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) study. Interventions have been shown to reduce post-thrombotic syndrome severity and improve quality of life in DVT patients, but have been accompanied by risk of major bleeding from thrombolytics. We describe thrombus removal using a novel combined basket-rotational thrombectomy device that minimizes the need for thrombolytics or repeat procedures. METHODS: The aim of this prospective, nonrandomized, multicenter, first-in-human study of 19 patients with acute iliofemoral DVT was to evaluate the safety and performance of the Pounce venous thrombectomy system ≤12 months after treatment. The primary performance end point was defined as procedural success through achievement of Society of Interventional Radiology (SIR) grade II lysis in treated vessels with freedom from procedural adverse events. Secondary end points included venous disease severity assessments using the Villalta scale and the Venous Clinical Severity Score, patient quality-of-life measurement using the Venous Insufficiency Epidemiological and Economic Study-Quality of Life questionnaire, and calf circumference measurements taken at baseline, 24 hours, and 1 month. RESULTS: The primary end point of complete or near-complete thrombus removal (Society of Interventional Radiology grade II or III) was achieved in all patients. All study device-related safety end points were met, with no major bleeding or device-related adverse events. Of the 19 patients treated, 16 (84.2%) did not receive thrombolytics during the procedure. Post-thrombotic syndrome (Villalta scale >4) was identified in 17 of 19 patients (89.5%) at baseline, 4 of 13 patients (30.8%) available for follow-up at 6 months, and 2 of 11 patients (18.2%) at 12 months. The median Venous Clinical Severity Score decreased (P < .001) from 8.5 (interquartile range [IQR], 7-10) at baseline to 4 (IQR, 2-4) at 1 month after the procedure and was similar at 6 months (2; IQR, 2-5) and 12 months (2; IQR, 1.5-3) after the procedure. The median Venous Insufficiency Epidemiological and Economic Study-Quality of Life questionnaire score improved (P < .001) by 39 from baseline (57; IQR, 53.5-74) to 1 month (96; IQR, 86-101) after the procedure, and remained high at 6 months (99; IQR, 75-103) and 12 months (98; IQR, 94.5-100). The median calf circumference decreased (P = .089) from 39 cm (IQR, 35-47.8 cm) at baseline to 36 cm (IQR, 32.5-40.5 cm) at 24 hours after the procedure and was 34.5 cm (IQR, 33.2-38.5 cm) at 1 month. CONCLUSIONS: The Pounce device is safe and effective for removal the of thrombus in patients with acute iliofemoral DVT. Initial results demonstrate improvements in venous disease severity and patient quality of life.

The role and principles of stenting in acute iliofemoral venous thrombosis.

Catheter-directed interventions for acute iliofemoral deep venous thrombosis (DVT) have been increasingly used over the past 15 years to target severe symptomatology and prevention of post-thrombotic syndrome incidence or reduce its severity if it were to develop. Aside from successful thrombus removal, adjunctive stents are frequently required to treat an uncovered lesion or significant residual thrombus to ensure quality of life improvement besides retarding DVT recurrence and post-thrombotic syndrome. As the evidence is mounting, the need and role for stenting, as well as the principles of an optimal technique, in the acute DVT setting are now better understood. Accumulating experience appears to favor stenting in the acute setting. The diameter of the stent, the length, the extent of overlapping, and the landing zones are crucial determinants of a successful durable outcome. This article endeavors to guide the interventionalist on stenting when encountering a patient with acute symptomatic iliofemoral DVT with concerns of quality of life impairment.

Three-Year Outcomes of the Abre Venous Self-Expanding Stent System in Patients with Symptomatic Iliofemoral Venous Outflow Obstruction.

PURPOSE: To report 36-month outcomes and subgroup analysis of the ABRE study evaluating the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction disease. METHODS: The ABRE study was a prospective, multicenter, nonrandomized study that enrolled and implanted Abre venous stents in 200 participants (mean age 51.5 years [SD ± 15.9], 66.5% women) with symptomatic iliofemoral venous outflow obstruction at 24 global sites. Outcomes assessed through 36 months included patency, major adverse events, stent migration, stent fracture, and quality-of-life changes. Adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively. RESULTS: Primary, primary-assisted, and secondary patency through 36 months by Kaplan-Meier estimates were 81.6%, 84.8%, and 86.3%, respectively. The cumulative incidence of major adverse events through 36 months was 10.2%, mainly driven by 12 thrombosis events. Subgroup analyses demonstrated a primary patency of 76.5% in the acute deep vein thrombosis group, 70.4% in the postthrombotic syndrome group, and 97.1% in the nonthrombotic iliac vein lesion group through 36 months. The overall mean lesion length was 112.4 mm (SD ± 66.1). There were no stent fractures or migrations in this study. Quality of life and venous functional assessments demonstrated significant improvements from baseline to 36 months across all patient subsets. CONCLUSIONS: Results from the ABRE study demonstrated sustained patency with a good safety profile after implantation of a dedicated venous stent in patients with symptomatic iliofemoral venous outflow obstruction disease.

Randomized controlled trials of interventions for acute iliofemoral deep venous thrombosis.

Venous thromboembolism (VTE), notably deep venous thrombosis (DVT), represents a significant cardiovascular disease with high morbidity from post-thrombotic syndrome (PTS). Recent advancements in early thrombus removal technologies have prompted randomized controlled trials (RCT) to assess their efficacy and safety, particularly for iliofemoral DVT (IF-DVT), which carries the greatest risk of developing PTS. This narrative review summarizes these trials and introduces upcoming innovations to evaluate acute intervention for IF-DVT. Specific technologies discussed include catheter-directed thrombolysis, pharmacomechanical catheter-directed thrombolysis, ultrasound-accelerated catheter-directed thrombolysis, and non-lytic mechanical thrombectomy. This review underscores the importance of patient selection, with those presenting with extensive, symptomatic IF-DVT likely to benefit most.

Mitochondrial network dynamics in pulmonary disease: Bridging the gap between inflammation, oxidative stress, and bioenergetics.

Once thought of in terms of bioenergetics, mitochondria are now widely accepted as both the orchestrator of cellular health and the gatekeeper of cell death. The pulmonary disease field has performed extensive efforts to explore the role of mitochondria in regulating inflammation, cellular metabolism, apoptosis, and oxidative stress. However, a critical component of these processes needs to be more studied: mitochondrial network dynamics. Mitochondria morphologically change in response to their environment to regulate these processes through fusion, fission, and mitophagy. This allows mitochondria to adapt their function to respond to cellular requirements, a critical component in maintaining cellular homeostasis. For that reason, mitochondrial network dynamics can be considered a bridge that brings multiple cellular processes together, revealing a potential pathway for therapeutic intervention. In this review, we discuss the critical modulators of mitochondrial dynamics and how they are affected in pulmonary diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), acute lung injury (ALI), and pulmonary arterial hypertension (PAH). A dysregulated mitochondrial network plays a crucial role in lung disease pathobiology, and aberrant fission/fusion/mitophagy pathways are druggable processes that warrant further exploration. Thus, we also discuss the candidates for lung disease therapeutics that regulate mitochondrial network dynamics.

Cost Effectiveness of Early Endovenous Thrombus Removal for Acute Iliofemoral Deep Vein Thrombosis in the United Kingdom.

OBJECTIVE: Early clot removal using endovascular intervention aims to reduce post-thrombotic syndrome (PTS) following iliofemoral deep venous thrombosis (DVT). This may reduce long term morbidity but incurs a higher initial cost. This study examined the cost effectiveness of catheter directed thrombolysis (CDT) and pharmacochemical thrombectomy (PMT) compared with oral anticoagulation (OAC) alone for treatment of acute iliofemoral DVT in the United Kingdom. METHODS: A combined decision tree (acute DVT complications) and Markov model (long term complications [PTS]) was used for decision analytic modelling with five states: no PTS, mild PTS, moderate PTS, severe PTS, and dead. All patients started with acute DVT. Patients who survived acute complications transitioned into the Markov model. Cycle time was six months. A healthcare payer perspective and lifetime horizon was used, adjusting for excess mortality due to history of thrombosis. Data for probabilities, transition probabilities, mortality, and utilities were obtained from the published literature. Cost data were obtained from UK NHS tariffs and published literature. Outcomes were mean lifetime cost, quality adjusted life years (QALYs), and cost effectiveness. RESULTS: Over a patient's lifetime, OAC was more costly (£37 206) than CDT (£32 043) and PMT (£36 288). Mean lifetime QALYs for OAC (12.9) were lower than CDT (13.5) and PMT (13.3). Therefore, in the incremental cost effectiveness analysis, both CDT and PMT were dominant: CDT was less costly (-£5 163) and more effective (+0.6 QALYs) than OAC, and PMT was also less costly (-£917) and more effective (+0.3 QALYs) than OAC. Results were robust to univariable sensitivity analyses, but probabilistic sensitivity analyses suggested considerable parameter uncertainty. CONCLUSION: Early interventional treatment of iliofemoral DVT is cost effective in the UK. Future clinical and epidemiological studies are needed to characterise parameter uncertainty. Further analysis of modern practice, alternative treatments, and optimised care models is warranted.

Simvastatin restores pulmonary endothelial function in the setting of pulmonary over-circulation.

Statin therapy is a cornerstone in the treatment of systemic vascular diseases. However, statins have failed to translate as therapeutics for pulmonary vascular disease. Early pulmonary vascular disease in the setting of congenital heart disease (CHD) is characterized by endothelial dysfunction, which precedes the more advanced stages of vascular remodeling. These features make CHD an ideal cohort in which to re-evaluate the potential pulmonary vascular benefits of statins, with a focus on endothelial biology. However, it is critical that the full gamut of the pleiotropic effects of statins in the endothelium are uncovered. The purpose of this investigation was to evaluate the therapeutic potential of simvastatin for children with CHD and pulmonary over-circulation, and examine mechanisms of simvastatin action on the endothelium. Our data demonstrate that daily simvastatin treatment preserves endothelial function in our shunt lamb model of pulmonary over-circulation. Further, using pulmonary arterial endothelial cells (PAECs) isolated from Shunt and control lambs, we identified a new mechanism of statin action mediated by increased expression of the endogenous Akt1 inhibitor, C-terminal modifying protein (CTMP). Increases in CTMP were able to decrease the Akt1-mediated mitochondrial redistribution of endothelial nitric oxide synthase (eNOS) which correlated with increased enzymatic coupling, identified by increases in NO generation and decreases in NOS-derived superoxide. Together our data identify a new mechanism by which simvastatin enhances NO signaling in the pulmonary endothelium and identify CTMP as a potential therapeutic target to prevent the endothelial dysfunction that occurs in children born with CHD resulting in pulmonary over-circulation.