Search Results (186)

Lung transplantation remains the standard of care for end-stage lung disease, yet a persistent gap exists between donor lung availability and growing clinical demand. Expanding the donor pool and optimising donor lung management are therefore critical priorities. However, no universally accepted management protocols are currently in place. This narrative review examines evidence-based strategies to improve lung utilisation across three donor categories: donors after brain death (DBD), controlled donors after circulatory death (cDCD), and uncontrolled donors after circulatory death (uDCD). A systematic literature search was conducted to identify interventions targeting lung preservation and function, including protective ventilation, recruitment manoeuvres, fluid and hormonal management, and ex vivo lung perfusion (EVLP). Distinct pathophysiological mechanisms—sympathetic storm and systemic inflammation in DBD, ischaemia–reperfusion injury in cDCD, and prolonged warm ischaemia in uDCD—necessitate tailored approaches to lung preservation. In DBD donors, early application of protective ventilation, bronchoscopy, and infection surveillance is essential. cDCD donors benefit from optimised pre- and post-withdrawal management to mitigate lung injury. uDCD donor lungs, uniquely vulnerable to ischaemia, require meticulous post-mortem evaluation and preservation using EVLP. Implementing structured, evidence-based lung management strategies can significantly enhance donor lung utilisation and expand the transplantable organ pool. The integration of such practices into clinical protocols is vital to addressing the global shortage of suitable lungs for transplantation. Full article

Background/Objectives: Ellagic acid (EA) is a polyphenol found in several fruits and vegetables, including pomegranate, nuts and berries. It exhibits significant health benefits, mainly cardio- and vaso-protective; indeed, EA protects the myocardium against infarction and inhibits cardiac fibrosis. These beneficial effects may be, at least in part, promoted by calcium release from and uptake by the sarcoplasmic reticulum, which are crucial events for cardiac relaxation and contraction. Regardless, the exact mechanism is currently unclear. Methods: A deeper investigation of the role of EA in cardiac contractility and the underlying mechanism has been carried out by using an ex vivo model of isolated and perfused rat heart. Results and Discussion: EA perfusion (100 nM–10 µM) did not influence the coronary flow (CF), suggesting the absence of a vasoactivity, but significantly increased contractility parameters (LVDP and dP/dt). Interestingly, a more marked effect of EA on LVDP and dP/dt values was observed when it was perfused in the presence of AngII. Cyclopiazonic acid (CA) and red ruthenium (RR), specific antagonists of SERCA and RyRs, respectively, were used to explore the contribution of EA when the intracellular calcium handling was altered. In the presence of CA, EA, perfused at increasing concentrations, showed a very modest positive inotropism (significant only at 1 µM). Instead, RR, which significantly compromised all functional parameters, completely masked the effects of EA; furthermore, a marked reduction in CF and a dramatic impact on the positive inotropism occurred. Conclusions: These results demonstrate the positive inotropism of EA on isolated and perfused hearts and suggest that the RyRs may be a main target through which EA plays its effects, since inhibition with RR almost completely blocks the positive inotropism. Full article

Background/Objectives: Hepatic clearance is important in determining clinical drug administration strategies. Achieving accurate hepatic clearance predictions through in vitro-to-in vivo extrapolation (IVIVE) relies on appropriate model selection, which is a critical step. Although numerous models have been developed to estimate drug dosage, some may fail to predict liver drug clearance owing to inappropriate hepatic clearance models during IVIVE. To address this limitation, an in silico-based model selection approach for optimizing hepatic clearance predictions was introduced in a previous study. The current study extends this strategy by verifying the accuracy of the selected models using ex situ experimental data, particularly for drugs whose model choices are influenced by protein binding. Methods: Commonly prescribed drugs were classified according to their hepatic extraction ratios and protein-binding properties. Building on previous studies that employed multinomial logistic regression analysis for model selection, a three-phase classification method was implemented to identify five representative drugs: diazepam, diclofenac, rosuvastatin, fluoxetine, and tolbutamide. Subsequently, an isolated perfused rat liver (IPRL) system was used to evaluate the accuracy of the in silico method. Results: As the unbound fraction increased for diazepam and diclofenac, the most suitable predictive model shifted from the initially preferred well-stirred model (WSM) to the modified well-stirred model (MWSM). For rosuvastatin, the MWSM provided a more accurate prediction. These three capacity-limited, binding-sensitive drugs conformed to the outcomes predicted by the multinomial logistic regression analysis. Fluoxetine was best described by the WSM, which is consistent with its flow-limited classification. For tolbutamide, a representative capacity-limited, binding-insensitive drug, no significant differences were observed among the various models. Conclusions: These findings demonstrate the accuracy of an in silico-based model selection approach for predicting liver metabolism and highlight its potential for guiding dosage adjustments. Furthermore, the IPRL system serves as a practical tool for validating the accuracy of the results derived from this approach. Full article

Organ shortage is a major challenge in transplantation, prompting the use of extended criteria donor grafts. These require improved preservation techniques and reliable methods to assess graft function. This study aimed to evaluate changes in the kidney metabolome following three preservation methods: normothermic ex vivo kidney perfusion (NEVKP), hypothermic machine perfusion (HMP) and static cold storage (SCS) in porcine autotransplant models. A chemical biopsy allowed minimally invasive sampling of metabolites, which were analyzed using liquid chromatography coupled with high-resolution mass spectrometry. The results highlighted metabolites affected by ischemia and oxidative stress in donor kidneys, as well as changes specific to each preservation method. Differences were observed immediately after transplantation and reperfusion and several days post-surgery. NEVKP was associated with the activation of physiological anti-oxidative and anti-inflammatory mechanisms, suggesting potential protective effects. However, some metabolites had dual roles, which may influence future graft treatment designs. HMP and SCS, while reducing energy demand in cells, also limit physiological repair mechanisms. These findings provide a basis for improving graft assessment and organ preservation, with chemical biopsy serving as both a tool for discovery and a potential diagnostic method for monitoring graft quality. Full article

Novel senotherapeutics are needed to reverse aging-related skin decline. The research question addressed was whether mesoglycan, a clinically approved glycosaminoglycan formulation known to enhance perfusion, angiogenesis, and VEGF-A signaling, possesses therapeutic potential for rejuvenating photo aged human skin. To test this, we treated full-thickness photoaged facial human skin samples (mean age: 72 ± 5 years) from seven women ex vivo. The samples were treated with topical or medium-delivered mesoglycan (100, 200, and 300 µM) for 6 days under serum-free conditions that accelerate skin aging. Biomarkers associated with aging were assessed using quantitative immunohistomorphometry. Mesoglycan treatment improved key skin aging biomarkers at all doses. Compared to vehicle-treated skin, mesoglycan broadly enhanced epidermal structure and function, improved pigmentation-related markers, reduced cellular senescence, boosted mitochondrial performance and antioxidant defenses, and improved dermal matrix structure and microvasculature density. Notably, mesoglycan also upregulated VEGF-A and VEGFR2, promoting skin rejuvenation. Medium-delivered mesoglycan produced stronger overall effects, while rete ridge reappearance was observed exclusively after topical application. Mesoglycan demonstrates senotherapeutic potential in photoaged human skin, acting via complementary pathways, including VEGF-A upregulation. Although medium-delivered mesoglycan yielded the greatest biomarker improvements topical application restored rete ridges, a sign of epidermal reorganization and also significantly enhanced basement membrane structure, pigmentation, mitochondrial function and antioxidant defenses, while avoiding systemic exposure, making it the safer and more feasible route for localized skin anti-aging. Full article

Early-onset heart failure is a major treat to healthy aging individuals with HIV-1 infection. Women with HIV-1 infection (WLWH) are especially vulnerable and develop heart failure with preserved ejection fraction (HFpEF), of which left ventricular diastolic dysfunction, vascular deficits, myocardial infarction, and fibrosis are major components. HIV-infected rodent models that exhibit these pathophysiological features remain under-reported, and this has left a void in our understanding of their molecular causes and therapeutic strategies to blunt its development. Here, we show that female NOD.Cg-Prkdc^scidIl2rgt^m1Wjl/SzJ humanized mice (Hu-mice) infected with HIV-1_ADA and treated for 13 weeks with dolutegravir (DTG)/tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) develop progressive diastolic dysfunction with preserved ejection fraction (E:A ratio, E:e′, IVRT, left atrial volume and global longitudinal strain increased by 32.1 ± 5.1%, 28.2 ± 5.6%, 100.2 ± 12.6%, 26.6 ± 4.2% and 32.5 ± 4.3%, respectively). In vivo photoacoustic imaging revealed a 30.4 ± 6.8% reduction in saturated oxygenated hemoglobin in the anterior wall of the heart. The ex vivo analysis of hearts showed a reduction in density of perfused microvessels/ischemia (30.6 ± 6.2%) with fibrosis (20.2 ± 1.2%). The HIF-1α level was increased 2.6 ± 0.5-fold, while inflammation-induced serum semicarbazide amine oxidase and glycolysis byproduct methylglyoxal increased 2-fold and 2.1-fold, respectively. Treating H9C2 cardiac myocytes with DTG, FTC and TDF dose-dependently increased expression of HIF-1α. These data show that HIV-infected Hu-mice treated with DTG/TDF/FTC for thirteen weeks develop cardiac diastolic dysfunction, with vascular deficits, ischemia, and fibrosis like those reported in women living with HIV-1 infection (WLWH). They also show that DTG, TDF, and FTC treatment can increase total HIF-1α in H9C2 cells. Full article

Background/Objectives: Pulmonary hypertension is a progressive disease leading to right heart failure. One treatment strategy is to induce vasodilation via the nitric oxide–soluble guanylate cyclase–cyclic guanosine monophosphate (NO–sGC–cGMP) signaling pathway. There are currently two soluble guanylate cyclase stimulators on the market: Riociguat and vericiguat, with vericiguat having a longer half-life and needing to be taken only once a day. This study investigated whether the pharmacological differences between the drugs affect pulmonary vessels and airways. Methods: The effects of vericiguat and riociguat on pulmonary arteries, veins, and airways were studied using rat precision-cut lung slices (PCLS). Vessels were pretreated with endothelin-1 and airways with serotonin. In isolated perfused lungs (IPL), the effects of sGC stimulation on pulmonary artery pressure (PAP), airway resistance, inflammatory cytokine, and chemokine release were quantified. Results: Riociguat and vericiguat caused pulmonary artery dilation in PCLS. During IPL, riociguat was more effective than vericiguat in reducing PAP with a statistically significant reduction of 10%. Both drugs were potent bronchodilators in preconstricted airways (p < 0.001). Only vericiguat reduced airway resistance during IPL, as shown here for the first time. Both drugs significantly reduced IL-6 and IL-1ß levels, while riociguat also reduced VEGF-A and KC-GRO levels. Conclusions: Riociguat and vericiguat had three main effects in the two rat ex-vivo models: They dilated the pulmonary arteries, induced bronchodilation, and reduced inflammation. These properties could make sGC stimulators useful for treating diseases associated with endothelial dysfunction. In the future, vericiguat may provide an alternative treatment to induce bronchodilation in respiratory diseases. Full article

Background/Objectives: Disrupted intracellular calcium (Ca²⁺_i) regulation and renin–angiotensin system (RAS) activation are pathogenetic factors in diabetic cardiomyopathy, a major complication of type 1 (T1D) and type 2 (T2D) diabetes. This study explored their potential link in diabetic rat hearts. Methods: Experiments were conducted on T1D and T2D Sprague-Dawley rats induced by streptozotocin and fructose-rich diet, respectively. In T1D, rats were treated with Enalapril (Ena) or Losartan (Los) for six weeks, whereas T2D animals received high-dose (HD) or low-dose (LD) Ena for 8 weeks. Heart function was assessed via echocardiography, Ca²⁺_i transients by Indo-1 fluorometry in Langendorff-perfused hearts, and key Ca²⁺_i cycling proteins by Western blot. Data: mean ± SD. Results: Diabetic hearts exhibited reduced contractile performance that was improved by RAS inhibition both in vivo (ejection fraction (%): T1D model: Control: 79 ± 7, T1D: 54 ± 11, T1D + Ena: 65 ± 10, T1D + Los: 69 ± 10, n = 18, 18, 15, 10; T2D model: Control: 73 ± 8, T2D: 52 ± 6, T2D + LDEna: 62 ± 8, T2D + HDEna: 76 ± 8, n = 9, 8, 6, 7) and ex vivo (+dPressure/dt_max (mmHg/s): T1D model: Control: 2532 ± 341, T1D: 2192 ± 208, T1D + Ena: 2523 ± 485, T1D + Los: 2643 ± 455; T2D model: Control: 2514 ± 197, T2D: 1930 ± 291, T2D + LDEna: 2311 ± 289, T2D + HDEna: 2614 ± 268). Analysis of Ca²⁺_i transients showed impaired Ca²⁺_i release and removal dynamics and increased diastolic Ca²⁺_i levels in both models that were restored by Ena and Los treatments. We observed a decrease in sarcoendoplasmic reticulum Ca²⁺-ATPase2a (SERCA2a) expression, accompanied by a compensatory increase in 16Ser-phosphorylated phospholamban (P-PLB) in T2D that was prevented by both LD and HD Ena (expression level (% of Control): SERCA2a: T2D: 36 ± 32, T2D + LDEna: 112 ± 32, T2D + HDEna: 106 ± 30; P-PLB: T2D: 557 ± 156, T2D + LDEna: 129 ± 38, T2D + HDEna: 108 ± 42; n = 4, 4, 4). Conclusions: The study highlights the critical role of RAS activation, most likely occurring at the tissue level, in disrupting Ca²⁺_i homeostasis in diabetic cardiomyopathy. RAS inhibition with Ena or Los mitigates these disturbances independent of blood pressure effects, underlining their importance in managing diabetic heart failure. Full article

Heart transplantation remains the preferred treatment for carefully selected patients with end-stage heart failure refractory to medical therapy. Advances in donor management, organ preservation, donor and recipient selection, immunosuppressive strategies, and mechanical circulatory support have significantly improved the safety and efficacy of heart transplantation. However, the persistent shortage of donor hearts and their limited preservation period continues to restrict access to this lifesaving procedure. The advent of innovative machine perfusion and temperature control systems for heart allograft preservation offers a promising avenue to address these challenges. These technologies aim to extend preservation times and enable the use of extended-criteria donors, thereby expanding the donor pool. In this review, we examine the outcomes from clinical trials, registry data, and single-center studies, utilizing the TransMedics Organ Care System Heart, Paragonix SherpaPak Cardiac Transport System, and XVIVO Heart Preservation System. As the field of heart transplantation evolves to accommodate longer ischemia times, expand organ sharing, and utilize donors previously considered marginal, the integration of these advanced technologies will be essential for optimizing post-transplant outcomes. Full article

Objectives: In addition to traditional ice-cold storage (ICS), other techniques are emerging in the field of donor heart preservation for heart transplantation (HTx). However, in many centers, it could be difficult to justify their use, due to the higher costs and the greater technical complexity compared to ICS. This study aims to analyze the results obtained for HTx at our center employing ICS, controlled hypothermia with Paragonix SherpaPak (PSP), and ex vivo normothermic perfusion with Organ Care System (OCS) as donor graft preservation strategies. Methods: All HTx performed at the University Hospital of Udine, between January 2020 and August 2024, was analyzed and patient outcomes and complications after HTx were assessed. Endomyocardial biopsies were performed in donor hearts immediately after retrieval (T₀), before implantation (T₁), and at reperfusion (T₂) to evaluate signs of myocardial damage. Results: Overall, 100 patients were transplanted with a donor heart preserved with ICS (n = 30), PSP (n = 36), or OCS (n = 34). Compared to ICS, PSP and OCS recipients showed a higher median IMPACT score (5 vs. 8 vs. 7, respectively, p = 0.05) and tended to have a higher rate of bridging to HTx with a long-term ventricular assist device (7% vs. 17% vs. 29%, p = 0.06). OCS was more commonly used in cases of expected ischemic time >4 h compared to ICS and PSP (p < 0.01). Histologically, severe degrees of cellular damage were higher in those hearts preserved with ICS. The 30-day mortality was 3% vs. 6% vs. 9% in ICS, PSP, and OCS groups, respectively (p = 0.65). Moderate-to-severe primary graft dysfunction was 37% vs. 11% vs. 17% (p = 0.03) in the three groups. Conclusions: PSP and OCS seem to be valid alternatives to traditional ICS, and their use could be strongly considered, particularly in the most complex and critical settings, until further data are available on more patient experiences. Full article

We developed ligandomics for the in vivo profiling of vascular ligands in mice, discovering secretogranin III (Scg3) as a novel angiogenic factor that selectively binds to retinal vessels of diabetic but not healthy mice. This discovery led to the development of anti-Scg3 therapy for ocular vasculopathies. However, in vivo ligandomics requires intracardial perfusion to remove unbound phage clones, limiting its use to vascular endothelial cells (ECs). To extend ligandomics to non-vascular cells, we investigated ex vivo ligandomics. We isolated ECs and retinal ganglion cells (RGCs) from diabetic and healthy mouse retinas by immunopanning. We quantified the binding of clonal phages displaying Scg3 and vascular endothelial growth factor (VEGF), confirming that their binding patterns to isolated diabetic versus healthy ECs matched in vivo patterns. Additionally, Scg3 and VEGF binding to isolated RGCs reflected their in vivo activity. These results support the feasibility of ex vivo ligandomics. We further mapped ligands binding to immunopanned diabetic and healthy ECs and RGCs by ligandomics, confirming that Scg3 was enriched with selective binding to diabetic ECs but not healthy ECs or diabetic/healthy RGCs. These findings demonstrate the feasibility of ex vivo ligandomics, which can be broadly applied to various cell types, tissues, diseases, and species. Full article

(1) Background: Ex Vivo Lung Perfusion (EVLP) is a technique designed to assess and recondition marginal lungs, potentially expanding the donor pool and improving transplant outcomes (2) Methods: This retrospective study evaluated lung transplantation outcomes after EVLP. Donor lungs were assessed using the Toronto protocol, with data on hemodynamics, gas exchange, and perfusion parameters collected and analyzed. Post-transplant complications and survival rates were also examined. (3) Results: Over five years, 17 EVLP procedures were performed. Despite an improvement in lung function, 47% of donor lungs were rejected after EVLP. EVLP-reconditioned lungs showed comparable survival rates to standard transplants, but complications like sepsis and primary graft dysfunction (PGD) occurred. (4) Conclusions: EVLP shows promise in expanding the donor organ availability and reducing PGD, but nearly half of the lungs assessed were rejected. Further research is necessary to optimize EVLP and address potential complications like lung injury and sepsis. Full article

Ischemic heart disease is the leading cause of death worldwide. Reduced oxygen supply and myocardial hypoxia lead to tissue damage and impairment of the heart function. To the best of our knowledge, the primary functional effects of hypoxia in the multicellular model of living myocardial slices (LMSs) have not been investigated so far. In this study, we analyzed force generation, ultrastructure, gene expression, and proteome changes in rat LMS after 24 h of ex vivo culture in normal and reduced levels of oxygen (O₂). We observed a significant reduction in absolute force and a slowdown of force kinetics as well as an increase in cardiomyocyte apoptosis and myofibrillar and mitochondrial damage, as well as transcriptomic changes. Proteome analysis revealed the deregulation of proteins involved in metabolic processes, hypoxic response, and neutralizing of reactive oxygen species. Our results indicate that hypoxia induces substantial primary changes in heart tissue, which are independent of perfusion and immune responses. Our new LMS model could serve as a screening system for drug development and new mechanistic insights. Full article

Background: Lung transplantation is the most effective treatment for end-stage respiratory diseases, but its application is limited by the shortage of organs. Ex vivo lung perfusion (EVLP) has emerged as a promising technique to evaluate and recondition donor lungs previously deemed unsuitable for transplantation. However, limitations such as lung contusions, air leaks, and perfusate extravasation, especially in portable EVLP systems, hinder the procedure. Despite prolonged perfusions that can result in blood pooling at the lung bases due to fixed lung positioning and diminished oncotic pressure, in some cases, extending perfusion time beyond the typical 5–6 h could benefit extended-criteria lungs, addressing factors such as edema or logistical complications. Methods: We present an innovative protocol involving prolonged EVLP, pronation of the graft, and the addition of anti-edematous drugs to the perfusate. Results: This novel approach, previously tested in animal models, enhances lung reconditioning and expands the donor pool. Conclusions: Our findings suggest that this strategy overcomes key limitations of standard EVLP, offering a valuable solution for improving the availability of transplantable lungs. Full article

Elevated risk for schizophrenia is associated with a variation in the DTNBP1 gene encoding dysbindin-1, which may underpin cognitive impairments in this prevalent neuropsychiatric disorder. The cognitive symptoms of schizophrenia involve anomalies in glutamate and dopamine signaling, particularly within the prefrontal cortex (PFC). Indeed, mice with Dtnbp1 mutations exhibit spatial and working memory deficits that are associated with deficits in glutamate release and NMDA receptor function as determined by slice electrophysiology. The present study extended the results from ex vivo approaches by examining how the Dtnbp1 mutation impacts high K+- and NMDA receptor-evoked glutamate release within the PFC using in vivo microdialysis procedures. Dntbp1 mutant mice are also reported to exhibit blunted K+-evoked dopamine release within the PFC. Thus, we examined also K+- and NMDA-evoked dopamine release within this region. Perfusion of high-concentration K+ or NMDA solutions increased the PFC levels of both dopamine and glutamate in wild-type (WT) but not in Dtnbp1 mutants (MUT), whereas mice heterozygous for the Dtnbp1 mutation (HET) exhibited blunted K+-evoked dopamine release. No net-flux microdialysis procedures confirmed elevated basal extracellular content of both glutamate and dopamine within the PFC of HET and MUT mice. These in vivo microdialysis results corroborate prior indications that Dtnbp1 mutations perturb evoked dopamine and glutamate release within the PFC, provide in vivo evidence for impaired NMDA receptor function within the PFC, and suggest that these neurochemical anomalies may be related to abnormally elevated basal neurotransmitter content. Full article