Tissue-type Plasminogen Activator Research Articles

COAGULATION AND ANTICOAGULATION PARAMETERS IN MULTIPLE SCLEROSIS PATIENTS WITH AND WITHOUT COVID-19

The aim. To investigate plasma levels of main coagulation and fibrinolytic factors in MS patients with and without COVID-19 history. Materials and methods. A total of 127 participants were enrolled in this study, including 97 MS patients and 30 healthy controls (HC). Patients with MS were divided into two groups: MS+Covid group (n=41) – patients with MS, who had a laboratory-verified diagnosis of COVID-19 in the past 3-6-month period and MS group (n=56) – patients with MS, who did not suffer from COVID-19 previously. Determination of plasma levels of prothrombin, plasminogen, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), protein C (PC), soluble thrombomodulin (TM) was performed by means of enzyme-linked immunosorbent assay. Spectrophotometric techniques were used to determine concentrations of fibrinogen, soluble fibrin monomeric complexes (SFMC) as well as plasminogen activity and inhibitory potential of α-2-antiplasmin. Results. The MS group was characterized by elevated levels of plasma prothrombin, fibrinogen, D-dimer, SFMC, soluble TM compared to HC, while PC concentration did not differ between MS and HC groups. Plasma plasminogen level as well as plasma level of the potential plasmin activity were significantly decreased in MS patients compared to HC group. The plasma tPA level was significantly reduced while plasma PAI-I level was significantly increased in MS patients compared to HC. Patients of MS group had an increased level of plasma α-2-antiplasmin activity compared with HC group. To note, most of studied parameters did not differ between two MS groups, except protein C, soluble thrombomodulin levels and plasma α-2-antiplasmin activity. Conclusions. The results of our study showed that MS patients have got altered hemostasis parameters; however, further study is necessary to find out the relationship between particular components of coagulation and fibrinolytic systems and pathophysiology of MS. Additionally, our findings demonstrated that a SARS-CoV-2 infection had a limited effect on hemostasis parameters in MS patients, causing changes in only a few parameters, including thrombomodulin and protein C levels as well as α-2-antiplasmin activity.

Correlations of 2 Novel Inflammation Indexes With the Risk for Early Neurological Deterioration in Acute Ischemic Stroke Patients After Intravenous Thrombolytic Therapy.

Elevation of the systemic immune inflammation (SII) index and system inflammation response index (SIRI) is known to be associated with higher risk of stroke and all-cause death. However, no study has reported their correlation with early neurological deterioration (END) following recombinant tissue-type plasminogen activator (IV-rtPA) in acute ischemic stroke patients. The aim of this study was to explore the correlation of SII and SIRI with the risk of END after IV-rtPA. Included in this study were 466 consecutive patients treated with IV-rtPA. SII and SIRI were calculated according to blood cell counts before IV-rtPA. Patients were divided into 3 groups based on trisectional quantiles according to SII and SIRI values. The risk of END was assessed by multivariate regression. The overall discriminative ability of SII and SIRI in predicting END was assessed by receiver operating characteristic curve analysis. Of the 466 included patients, 62 (13.3%) were identified as having END. Compared with the first tertile of SII, multivariable regression analysis demonstrated that patients were more likely to have END (odds ratio 2.54; 95% CI: 1.23-5.23) and poor outcome at 90 days (odds ratio 2.02; 95% CI: 1.06-3.86) in third tertile after adjustment for potential confounders. In addition, a cutoff value of 591.63 for SII was detected in predicting post-thrombolysis END with a sensitivity of 58.1% and a specificity of 64.6% (area under the curve 0.61; 95% CI: 0.54-0.69). Higher SII but not SIRI may prove to be a predictor for high risk of END and a poor functional outcome at 90 days after IV-rtPA.

Targeted Thrombolysis with Magnetic Nanotherapeutics: A Translational Assessment.

Plasminogen activators, such as recombinant tissue-type plasminogen activators (rtPAs), while effective in treating thromboembolic diseases, often induce hemorrhagic complications due to non-specific enzyme activities in the systemic circulation. This study evaluated the targeting efficiency, efficacy, biodistribution, and potential toxicity of a rtPA covalently attached to chitosan-coated magnetic nanoparticles (chitosan-MNP-rtPA). The thrombolytic activity of a chitosan-MNP-rtPA was preserved by protection from an endogenous plasminogen activator inhibitor-1 (PAI-1) in whole blood and after circulation in vivo, as examined by thromboelastometry. Single-photon emission computed tomography (SPECT) demonstrated real-time retention of a 99mTc-MNP-rtPA induced by magnet application in a rat embolic model; an 80% reduction in rtPA dosage for a chitosan-MNP-rtPA with magnetic guidance was shown to restore blood flow. After treatment, iron deposition was observed in the reticuloendothelial systems, with portal edema and neutrophil infiltration in the liver at a ten-fold higher dose but not the regular dose. Nevertheless, no liver or renal toxicity was observed at this higher dose. In conclusion, the liver may still be the major deposit site of rtPA nanocomposites after targeted delivery; chitosan-coated MNPs are potentially amenable to target therapeutics with parenteral administration.

Case report: Tenecteplase for acute ischemic stroke after heparin reversal

Intravenous thrombolysis can be administered to appropriate patients with suspected acute ischemic strokes who are on intravenous heparin infusions after its rapid reversal with protamine sulfate. Several case reports suggest the safety of tissue-type plasminogen activator, or alteplase, in these scenarios. Noting the increasing preferential use of tenecteplase over alteplase for intravenous thrombolysis of acute ischemic stroke, the safe and efficacious use of tenecteplase following heparin reversal has not been demonstrated in the literature. Our case demonstrates successful use of intravenous tenecteplase in a patient who was anticoagulated with therapeutic heparin. The patient had no hemorrhagic complications and had an excellent neurological outcome.

Acupuncture Extended the Thrombolysis Window by Suppressing Blood-Brain Barrier Disruption and Regulating Autophagy-Apoptosis Balance after Ischemic Stroke.

Ischemic stroke (IS) is one of the leading causes of death and disability worldwide. The narrow therapeutic window (within 4.5 h) and severe hemorrhagic potential limits therapeutic efficacy of recombinant tissue type plasminogen activator (rt-PA) intravenous thrombolysis for patients. Xingnao Kaiqiao (XNKQ) acupuncture is an integral part of traditional Chinese medicine, specifically designed to address acute ischemic stroke by targeting key acupoints such as Shuigou (GV26) and Neiguan (PC6). In this study, we explored the therapeutic potential of XNKQ acupuncture in extending the time window for thrombolysis and interrogated the molecular mechanisms responsible for this effect. The effect of extending the thrombolysis window by acupuncture was evaluated via TTC staining, neuronal score evaluation, hemorrhagic transformation assay, and H&E staining. RNA sequencing (RNA-seq) technology was performed to identify the therapeutic targets and intervention mechanisms of acupuncture. Evans blue staining and transmission electron microscopy were used to assess blood-brain barrier (BBB) integrity. Immunofluorescence staining and co-immunoprecipitation were performed to evaluate the level of autophagy and apoptosis and validate their interactions with BBB endothelial cells. Acupuncture alleviated infarction and neurological deficits and extended the thrombolysis window to 6 h. The RNA-seq revealed 16 potential therapeutic predictors for acupuncture intervention, which related to suppressing inflammation and restoring the function of BBB and blood vessels. Furthermore, acupuncture suppressed BBB leakage and preserved tight junction protein expression. The protective effect was associated with regulation of the autophagy-apoptosis balance in BBB endothelial cells. Acupuncture intervention dissociated the Beclin1/Bcl-2 complex, thereby promoting autophagy and reducing apoptosis. XNKQ acupuncture could serve as an adjunctive therapy for rt-PA thrombolysis, aiming to extend the therapeutic time window and mitigate ischemia-reperfusion injury. Acupuncture suppressed BBB disruption by regulating the autophagy-apoptosis balance, which in turn extended the therapeutic window of rt-PA in IS. These findings provide a rationale for further exploration of acupuncture as a complementary candidate co-administered with rt-PA.

The Janus face of endogenous neuronal tPA: promoting self-protection and worsening the death of neighboring neurons

Recombinant tissue-type plasminogen activator (r-tPA/Actilyse) stands as the prevailing pharmacological solution for treating ischemic stroke patients, of whom because their endogenous circulating tPA alone is not sufficient to rescue reperfusion and to promote favorable outcome. Beyond the tPA contributed by circulating endothelial cells and hepatocytes, neurons also express tPA, sparking debates regarding its impact on neuronal fate ranging from pro-survival to neurotoxic properties. In order to investigate the role of neuronal tPA during brain injuries, we developed models leading to its conditional deletion in neurons, employing AAV9-pPlat-GFP and AAV9-pPlat-Cre-GFP along with tPA floxed mice. These models were subjected to N-methyl-D-aspartate (NMDA)-induced excitotoxicity or thromboembolic ischemic stroke in mice. Initially, we established that our AAV9 constructs selectively transduce neurons, bypassing other brain cell types. Subsequently, we demonstrated that tPA-expressing neurons exhibit greater resistance against NMDA-induced excitotoxicity compared to tPA negative neurons. The targeted removal of tPA in neurons heightened the susceptibility of these neurons to cell death and prevented a paracrine neurotoxic effect on tPA non-expressing neurons. Under ischemic conditions, the self-neuroprotective influence of tPA encompassed both excitatory (GFP+/Tbr1+) and inhibitory (GFP+/GABA+) neurons. Our data indicate that endogenous neuronal tPA is a protective or deleterious factor against neuronal death in an excitotoxic/ischemic context, depending on whether it acts as an autocrine or a paracrine mediator.

Impact of a novel pre-hospital stroke notification programme on acute stroke care key performance indicators in Hong Kong: a multicentre prospective cohort study with historical controls.

Early identification and initiation of reperfusion therapy is essential for suspected acute ischaemic stroke. A pre-hospital stroke notification (PSN) protocol using FASE (facial drooping, arm weakness, speech difficulties, and eye palsy) was implemented to improve key performance indicators (KPIs) in acute stroke care delivery. We assessed KPIs and clinical outcomes before and after PSN implementation in Hong Kong. This prospective cohort study with historical controls was conducted in the Accident and Emergency Departments of four public hospitals in Hong Kong. Patients were screened using the PSN protocol between August 2021 and February 2022. Suspected stroke patients between August 2020 and February 2021 were included as historical controls. Door-to-needle (DTN) and door-to-computed tomography (DTC) times before and after PSN implementation were compared. Clinical outcomes including National Institutes of Health Stroke Scale score at 24 hours and modified Rankin Scale score at 3 months after intravenous recombinant tissue-type plasminogen activator (IV-rtPA) were also assessed. Among the 715 patients (266 PSN and 449 non-PSN) included, 50.8% of PSN patients and 37.7% of non-PSN patients had a DTC time within 25 minutes (P<0.001). For the 58 PSN and 134 non-PSN patients given IV-rtPA, median DTN times were 67 and 75.5 minutes, respectively (P=0.007). The percentage of patients with a DTN time within 60 minutes was higher in the PSN group than in the non-PSN group (37.9% vs 21.6%; P=0.019). No statistically significant differences in clinical outcomes were observed. Although the PSN protocol shortened DTC and DTN times, clinical outcomes did not significantly differ.

Impact of Local Tailoring on Acute Stroke Care in 21 Disparate Emergency Departments: A Prospective Stepped Wedge Type III Hybrid Effectiveness-Implementation Study.

Faster delivery of tPA (tissue-type plasminogen activator) results in better health outcomes for eligible patients with stroke. Standardization of stroke protocols in emergency departments (EDs) has been difficult, especially in nonstroke centers. We measured the effectiveness of a centrally led implementation strategy with local site tailoring to sustain adherence to an acute stroke protocol to improve door-to-needle (DTN) times across disparate EDs in a multihospital health system. Prospective, type III hybrid effectiveness-implementation cohort study measuring performance at 21 EDs in Utah and Idaho (stroke centers [4]/nonstroke centers [17]) from January 2018 to February 2020 using a nonrandomized stepped-wedge design, monthly repeated site measures and multilevel hierarchical modeling. Each site received the implementation strategies in 1 of 6 steps providing control and intervention data. Co-primary outcomes were percentage of DTN times ≤60 minutes and median DTN time. Secondary outcomes included percentage of door-to-activation of neurological consult times ≤10 minutes and clinical effectiveness outcomes. Results were stratified between stroke and nonstroke centers. A total of 855 474 ED patient encounters occurred with 5325 code stroke activations (median age, 69 [IQR, 56-79] years; 51.8% female patients]. Percentage of door-to-activation times ≤10 minutes increased from 47.5% to 59.9% (adjusted odds ratio, 1.93 [95% CI, 1.40-2.67]). A total of 615 patients received tPA of ≤3 hours from symptom onset (median age, 71 [IQR, 58-80] years; 49.6% female patients). The percentage of DTN times ≤60 minutes increased from 72.5% to 86.1% (adjusted odds ratio, 3.38, [95% CI, 1.47-7.78]; stroke centers (77.4%-90.0%); nonstroke centers [59.3%-72.1%]). Median DTN time declined from 46 to 38 minutes (adjusted median difference, -9.68 [95% CI, -17.17 to -2.20]; stroke centers [41-35 minutes]; nonstroke centers [55-52 minutes]). No differences were observed in clinical effectiveness outcomes. A centrally led implementation strategy with local site tailoring led to faster delivery of tPA across disparate EDs in a multihospital system with no change in clinical effectiveness outcomes including rates of complication. Disparities in performance persisted between stroke and nonstroke centers.

Comparison of results obtained using clot-fibrinolysis waveform analysis and global fibrinolysis capacity assay with rotational thromboelastography

Global fibrinolysis assays detect the fibrinolysis time of clot dissolution using tissue-type plasminogen activator (tPA). Two such assays, clot-fibrinolysis waveform analysis (CFWA) and global fibrinolysis capacity (GFC) assay, were recently developed. These were compared with rotational thromboelastography (ROTEM). Healthy donor blood samples were divided into four groups based on tPA-spiked concentrations: 0, 100, 500, and 1000 ng/mL. CFWA and GFC fibrinolysis times, including 4.1 µg/mL and 100 ng/mL tPA in the assays, were determined, denoted as CFWA-Lys and GFC-Lys, respectively. Statistical differences were recognized between tPA concentrations of 0 and 500/1000 ng/mL for CFWA-Lys, and 0 and 100/500/1000 ng/mL for GFC-Lys. The correlation coefficients with lysis onset time (LOT) of extrinsic pathway evaluation and intrinsic pathway evaluation in ROTEM were statistically significant at 0.610 and 0.590 for CFWA-Lys, and 0.939 and 0.928 for GFC-Lys, respectively (p-values < 0.0001 for all correlations). Both assays showed significant correlations with ROTEM; however, the GFC assay proved to have better agreement with ROTEM compared with the CFWA assay. These assays have the potential to reflect a hyperfibrinolysis status with high tPA concentrations.

Impact of Off-Hour Admission on In-Hospital Outcomes for Patients With Stroke Receiving Reperfusion Therapy in China.

The structure and staffing of hospitals greatly impact patient outcomes, with frequent changes occurring during nights and weekends. This retrospective cohort study assessed the impact of admission timing on in-hospital management and outcomes for patients with stroke receiving reperfusion therapy in China using data from a nationwide registry. Data from patients receiving reperfusion therapy were extracted from the Chinese Stroke Center Alliance. Hospital admission time was categorized according to day/evening versus night and weekday versus weekend. Primary outcomes were in-hospital death or discharge against medical advice, hemorrhage transformation, early neurological deterioration, and major adverse cardiovascular events. Logistic regression was performed to compare in-hospital management performance and outcomes based on admission time categories. Overall, 42 381 patients received recombinant tissue-type plasminogen activator (r-tPA) therapy, and 5224 underwent endovascular treatment (EVT). Patients admitted during nighttime had a higher probability of receiving r-tPA therapy within 4.5 hours from onset or undergoing EVT within 6 hours from onset compared with those admitted during day/evening hours (adjusted odds ratio, 1.04 [95% CI, 1.01-1.08]; P=0.021; adjusted odds ratio, 1.72 [95% CI, 1.59-1.86]; P<0.001, respectively). However, no significant difference was observed between weekend and weekday admissions for either treatment. No notable differences were noted between weekends and weekdays or nighttime and daytime periods in door-to-needle time for r-tPA or door-to-puncture time for EVT initiation. Furthermore, weekend or nighttime admission did not have a significant effect on the primary outcomes of r-tPA therapy or EVT. Nevertheless, in patients undergoing EVT, a higher incidence of pneumonia was observed among those admitted at night compared with those admitted during day/evening hours (adjusted odds ratio, 1.22 [95% CI, 1.05-1.42]; P=0.011). Patients admitted at nighttime were more likely to receive r-tPA therapy or EVT within the time window recommended in the guidelines. However, patients receiving EVT admitted at night had an increased risk of pneumonia.

R-tPA Resistance Is Specific for Platelet-Rich Stroke Thrombi and Can Be Overcome by Targeting Nonfibrin Components.

Resistance to r-tPA (recombinant tissue-type plasminogen activator) is a well-known but poorly understood phenomenon that hampers successful recanalization in patients with acute ischemic stroke. Using clinically relevant thrombi from patients with acute ischemic stroke, we investigated if and how thrombus composition impacts r-tPA-mediated lysis. In addition, we explored strategies to overcome r-tPA resistance. Thrombi were split into 2 parts, 1 of which was used for thrombolysis and the other for detailed histological analysis. Thrombolysis was performed in normal human plasma using r-tPA alone, using r-tPA in combination with DNase-1 or using r-tPA in combination with N,N'-diacetyl-l-cystine. Thrombus lysis was calculated as the percentage of residual thrombus weight compared with its initial weight and the degree of lysis was linked to thrombus composition determined via histology. Interestingly, we found that the efficacy of r-tPA-mediated thrombolysis was strongly correlated with the composition of the thrombi. Thrombi containing high amounts of red blood cells and low amounts of DNA and von Willebrand Factor were efficiently degraded by r-tPA, whereas thrombi containing low amounts of red blood cells and higher amounts of DNA and von Willebrand Factor were resistant to r-tPA. Importantly, combination of r-tPA with DNase-1 or N,N'-diacetyl-l-cystine significantly and specifically improved the lysis of these r-tPA-resistant thrombi. Using patient thrombus material, our results for the first time show that the composition of stroke thrombi largely determines their susceptibility to r-tPA-mediated thrombolysis. Red blood cell-poor thrombi have a specific resistance to r-tPA, which can be overcome by targeting nonfibrin components using DNase-1 or N,N'-diacetyl-l-cystine.

Fibrinolysis as a causative mechanism for bleeding complications on ECMO: a pilot observational prospective study.

Extracorporeal membrane oxygenation (ECMO) is associated with a high risk of bleeding complications. The specific impact of ECMO on fibrinolysis remains unexplored. The objective of the current pilot observational prospective study was to investigate the longitudinal dynamics of fibrinolytic markers - i.e., changes over time - in the context of bleeding events in patients on ECMO. Longitudinal dynamics of contact phase components (kininogen and bradykinin) and fibrinolysis markers (tissue-type plasminogen activator [t-PA], plasminogen activator inhibitor-1 [PAI-1], their complexes [t-PA•PAI-1], plasmin-antiplasmin complexes, plasminogen, and D-dimer) were measured in patients undergoing veno-venous and veno-arterial ECMO, before implantation, at 0, 6, and 12 hours post-implantation, and daily thereafter. The cohort consisted of 30 patients (214 ECMO-days). The concentrations of t-PA, D-dimer, plasmin-antiplasmin complexes, PAI-1 and t-PA•PAI-1 complexes were increased, whereas plasminogen decreased compared to normal values. A noteworthy divergence was observed between hemorrhagic and non-hemorrhagic patients: in bleeding patients, D-dimer, plasmin-antiplasmin, t-PA, PAI-1 and t-PA•PAI-1 followed an increasing kinetics before hemorrhage and then decreased to their baseline level; conversely non-bleeding patients showed a decreasing kinetics in these markers. Also, D-dimer and t-PA followed an increasing kinetics in bleeding patients compared to non-bleeding patients (median values for D-dimer dynamics: 1080 vs. -440 ng/mL, p=0.05; t-PA dynamics: 0.130 vs. 0.100 nM, p=0.038), and both markers significantly increased the day before hemorrhage. A t-PA concentration above 0.304 nM was associated with bleeding events (OR 4.92, 95% CI [1.01-24.08], p=0.049). Contact activation induces fibrinolysis in ECMO patients, especially in patients experiencing bleeding. This finding supports the role of this mechanism as a possible causal factor for hemorrhages during ECMO and open new avenues for novel therapeutic perspectives. Extracorporeal membrane oxygenation (ECMO) is associated with a high risk of bleeding complications due to multiple factors. However, the role of the fibrinolytic system is not well understood in this setting. In patients requiring cardiac and/or pulmonary support with ECMO, D-dimer and tissue plasminogen activator levels were increased with bleeding, findings consistent with fibrinolysis.Although there are multiple causes for fibrinolysis during ECMO, their study suggests that patients who bled had increased contact activation, and may benefit from novel therapeutic agents that inhibit hemostatic activation through this pathway.

Abstract P523: Circulating Endothelial-Cell Derived Microvesicles Associated With Insufficient Sleep Impairs Cerebral Microvascular Fibrinolytic Capacity

Chronic insufficient sleep (&lt; 7 hour/night) is associated with increased risk of ischemic stroke. Endothelial cell dysfunction, specifically impairment endothelial release of tissue-type plasminogen activator (t-PA), represents an important mechanism underlying cerebrovascular events such as ischemic stroke. Endothelial cells are the primary site of synthesis and release of t-PA, the plasminogen activator in fibrinolysis and, thus, a key regulator of endogenous thrombolysis. We have previously demonstrated that insufficient sleep is associated with impaired endothelial capacity to release t-PA, however the mechanisms for the sleep-related fibrinolytic impairment are not well understood. Clinical interest in endothelial cell-derived microvesicles (EMVs) has intensified due to their involvement in the development of endothelial dysfunction and, in turn, cardiovascular and cerebrovascular events. The aim of this study was to determine, in vitro, the effects of circulating EMVs isolated from adults with chronic insufficient sleep on brain endothelial cell t-PA release. Considering EMVs are known to cross the blood brain barrier and are associated with ischemic stroke incidence, severity and outcome; circulating EMVs associated with insufficient sleep may be a mediator of stroke risk. Twenty-four healthy, non-obese, normotensive, sedentary adults (age: 23-69 years) were studied: 12 normal nightly sleep duration (7M/5F; age: 47±5 yr; nightly sleep: 7.4±0.1 hour/night) and 12 with short nightly sleep duration (9M/3F; 53±4 yr; 5.9±0.2 hour/night). EMV identification (CD144+) and isolation from peripheral blood was performed by flow cytometry. Human cerebral microvascular endothelial cells (hCMECs) were cultured and separately treated with EMVs from each subject. Cultured hCMECs were treated with EMVs in the absence and presence of thrombin (1 unit/mL) for 24 hours. Intracellular expression of t-PA was significantly lower (~30%) in hCMECs treated with EMVs from adults with insufficient sleep (31±3 AU) compared with cells treated with EMVs from normal sleep adults (40±3 AU). Although the effect of EMVs on basal t-PA release was not different between the groups; thrombin-stimulated t-PA release was significantly lower in cells treated with EMVs from adults with insufficient sleep (from 57±3 to 59±4 ng/mL) compared with EMVs from adults with normal sleep (from 53±3 to 66±4 ng/mL). The capacity of hCMECs to release t-PA in response to thrombin was ~75% lower when treated with EMVs from adults with insufficient sleep. These results indicate that circulating EMVs associated with chronic insufficient sleep diminishes brain endothelial cell t-PA production and impairs t-PA release. Circulating EMVs represent a mechanistic factor in insufficient sleep-related fibrinolytic dysfunction and ischemic stroke risk.

LOX-1 and MMP-9 Inhibition Attenuates the Detrimental Effects of Delayed rt-PA Therapy and Improves Outcomes After Acute Ischemic Stroke.

Acute ischemic stroke triggers endothelial activation that disrupts vascular integrity and increases hemorrhagic transformation leading to worsened stroke outcomes. rt-PA (recombinant tissue-type plasminogen activator) is an effective treatment; however, its use is limited due to a restricted time window and hemorrhagic transformation risk, which in part may involve activation of MMPs (matrix metalloproteinases) mediated through LOX-1 (lectin-like oxLDL [oxidized low-density lipoprotein] receptor 1). This study's overall aim was to evaluate the therapeutic potential of novel MMP-9 (matrix metalloproteinase 9) ± LOX-1 inhibitors in combination with rt-PA to improve stroke outcomes. A rat thromboembolic stroke model was utilized to investigate the impact of rt-PA delivered 4 hours poststroke onset as well as selective MMP-9 (JNJ0966) ±LOX-1 (BI-0115) inhibitors given before rt-PA administration. Infarct size, perfusion, and hemorrhagic transformation were evaluated by 9.4-T magnetic resonance imaging, vascular and parenchymal MMP-9 activity via zymography, and neurological function was assessed using sensorimotor function testing. Human brain microvascular endothelial cells were exposed to hypoxia plus glucose deprivation/reperfusion (hypoxia plus glucose deprivation 3 hours/R 24 hours) and treated with ±tPA and ±MMP-9 ±LOX-1 inhibitors. Barrier function was assessed via transendothelial electrical resistance, MMP-9 activity was determined with zymography, and LOX-1 and barrier gene expression/levels were measured using qRT-PCR (quantitative reverse transcription PCR) and Western blot. Stroke and subsequent rt-PA treatment increased edema, hemorrhage, MMP-9 activity, LOX-1 expression, and worsened neurological outcomes. LOX-1 inhibition improved neurological function, reduced edema, and improved endothelial barrier integrity. Elevated MMP-9 activity correlated with increased edema, infarct volume, and decreased neurological function. MMP-9 inhibition reduced MMP-9 activity and LOX-1 expression. In human brain microvascular endothelial cells, LOX-1/MMP-9 inhibition differentially attenuated MMP-9 levels, inflammation, and activation following hypoxia plus glucose deprivation/R. Our findings indicate that LOX-1 inhibition and ± MMP-9 inhibition attenuate negative aspects of ischemic stroke with rt-PA therapy, thus resulting in improved neurological function. While no synergistic effect was observed with simultaneous LOX-1 and MMP-9 inhibition, a distinct interaction is evident.

Causal association between cardiovascular proteins and membranous nephropathy: a bidirectional Mendelian randomization.

Multiple circulating proteins have been reported to participate in human diseases. However, the association between cardiovascular proteins and membranous nephropathy (MN) remained profoundly elusive. A bidirectional Mendelian randomization (MR) analysis was conducted to explore the causal correlation between ninety cardiovascular proteins and MN. Genome-wide association study (GWAS) data of cardiovascular proteins and MN were all from European research. Inverse variance weighted (IVW) was used as the main approach. Moreover, MR-Egger, weighted median, weighted mode, and simple mode were also performed. Cochrane's Q test, MR-Egger, and MR-PRESSO were conducted for sensitivity analysis. According to IVW method, fatty acid-binding protein and thrombomodulin (TM) were identified as risk factors for MN, while a protective role was detected in tissue-type plasminogen activator. Additionally, MN was associated with an elevated level of macrophage colony-stimulating factor 1, stem cell factor, TM, and tissue factor. Reversely, MN was also correlated with a downregulated level of beta-nerve growth factor, Cathepsin D, hepatocyte growth factor, interleukin-6 receptor subunit alpha, macrophage colony-stimulating factor 1, and myeloperoxidase. In the sensitivity analysis, no significant pleiotropy and heterogeneity was detected. This was the first study to reveal the causal association between cardiovascular proteins and MN. These specific cardiovascular proteins could be novel biomarkers for MN, and is helpful for timely identify the risk of other diseases that might result from MN. However, further clinical studies are needed to confirm our results.

The Roles of Fibrinolytic Factors in Bone Destruction Caused by Inflammation.

Chronic inflammatory diseases, such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus, Crohn's disease, periodontitis, and carcinoma metastasis frequently result in bone destruction. Pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-17 are known to influence bone loss by promoting the differentiation and activation of osteoclasts. Fibrinolytic factors, such as plasminogen (Plg), plasmin, urokinase-type plasminogen activator (uPA), its receptor (uPAR), tissue-type plasminogen activator (tPA), α2-antiplasmin (α2AP), and plasminogen activator inhibitor-1 (PAI-1) are expressed in osteoclasts and osteoblasts and are considered essential in maintaining bone homeostasis by regulating the functions of both osteoclasts and osteoblasts. Additionally, fibrinolytic factors are associated with the regulation of inflammation and the immune system. This review explores the roles of fibrinolytic factors in bone destruction caused by inflammation.

Age-Related Changes in Clinical and Analytical Variables in Chronic Hemodialyzed Patients.

Worldwide, the number of elderly individuals receiving chronic hemodialysis is rising. The aim of our study was to evaluate several clinical and analytical biomarkers in chronically dialyzed patients and analyze how they change with age. A cross-sectional study was performed by evaluating 289 end-stage renal disease patients undergoing dialysis. We evaluated the hemogram, adipokines, the lipid profile, and several markers related to inflammation, endothelial function/fibrinolysis, nutrition, iron metabolism, and cardiac and renal fibrosis. Clinical data and dialysis efficacy parameters were obtained from all patients. The relationships between studied biomarkers and age were assessed by a statistical comparison between younger (adults with age < 65 years) and older (age ≥ 65 years) patients and by performing regression analysis. Participants presented a mean age of 68.7 years (±13.6), with 66.8% (n = 193) being classified as older. Compared to younger patients, older patients presented the following: (a) significantly lower values of diastolic blood pressure (DBP) and ultrafiltration volume; (b) lower levels of phosphorus, uric acid, creatinine, and albumin; and (c) higher circulating concentrations of tissue-type plasminogen activator (tPA), D-dimer, interleukin-6, leptin, N-terminal pro B-type natriuretic peptide, and tissue inhibitor of metalloproteinase-1. In the multiple linear regression analysis, DBP values, tPA, phosphorus, and D-dimer levels were independently associated with the age of patients (standardized betas: -0.407, 0.272, -0.230, and 0.197, respectively; p < 0.001 for all), demonstrating relevant changes in biomarkers with increasing age at cardiovascular and nutritional levels. These findings seem to result from crosstalk mechanisms between aging and chronic kidney disease.

Quantitative Proteomics Reveal Region-Specific Alterations in Neuroserpin-Deficient Mouse Brain and Retina: Insights into Serpini1 Function.

Neural regeneration and neuroprotection represent strategies for future management of neurodegenerative disorders such as Alzheimer's disease (AD) or glaucoma. However, the complex molecular mechanisms that are involved in neuroprotection are not clearly understood. A promising candidate that maintains neuroprotective signaling networks is neuroserpin (Serpini1), a serine protease inhibitor expressed in neurons which selectively inhibits extracellular tissue-type plasminogen activator (tPA)/plasmin and plays a neuroprotective role during ischemic brain injury. Abnormal function of this protein has been implicated in several conditions including stroke, glaucoma, AD, and familial encephalopathy with neuroserpin inclusion bodies (FENIB). Here, we explore the potential biochemical roles of Serpini1 by comparing proteome changes between neuroserpin-deficient (NS-/-) and control mice, in the retina (RE), optic nerve (ON), frontal cortex (FC), visual cortex (VC), and cerebellum (CB). To achieve this, a multiple-plex quantitative proteomics approach using isobaric tandem mass tag (TMT) technology was employed followed by functional enrichment and protein-protein interaction analysis. We detected around 5000 proteins in each tissue and a pool of 6432 quantified proteins across all regions, resulting in a pool of 1235 differentially expressed proteins (DEPs). Principal component analysis and hierarchical clustering highlighted similarities and differences in the retina compared to various brain regions, as well as differentiating NS-/- proteome signatures from control samples. The visual cortex revealed the highest number of DEPs, followed by cerebellar regions. Pathway analysis unveiled region-specific changes, including visual perception, focal adhesion, apoptosis, glutamate receptor activation, and supramolecular fiber organization in RE, ON, FC, VC, and CB, respectively. These novel findings provide comprehensive insights into the region-specific networking of Serpini1 in the central nervous system, further characterizing its potential role as a neuroprotective agent. Data are available via ProteomeXchange with identifier PXD046873.

Parabiosis Discriminates the Circulating, Endothelial, and Parenchymal Contributions of Endogenous Tissue-Type Plasminogen Activator to Stroke.

Intravenous injection of alteplase, a recombinant tPA (tissue-type plasminogen activator) as a thrombolytic agent has revolutionized ischemic stroke management. However, tPA is a more complex enzyme than expected, being for instance able to promote thrombolysis, but at the same time, also able to influence neuronal survival and to affect the integrity of the blood-brain barrier. Accordingly, the respective impact of endogenous tPA expressed/present in the brain parenchyma versus in the circulation during stroke remains debated. To address this issue, we used mice with constitutive deletion of tPA (tPANull [tPA-deficient mice]) or conditional deletion of endothelial tPA (VECad [vascular endothelial-Cadherin-Cre-recombinase]-Cre∆tPA). We also developed parabioses between tPANull and wild-type mice (tPAWT), anticipating that a tPAWT donor would restore levels of tPA to normal ones, in the circulation but not in the brain parenchyma of a tPANull recipient. Stroke outcomes were investigated by magnetic resonance imaging in a thrombo-embolic or a thrombotic stroke model, induced by local thrombin injection or FeCl3 application on the endothelium, respectively. First, our data show that endothelial tPA, released into the circulation after stroke onset, plays an overall beneficial role following thrombo-embolic stroke. Accordingly, after 24 hours, tPANull/tPANull parabionts displayed less spontaneous recanalization and reperfusion and larger infarcts compared with tPAWT/tPAWT littermates. However, when associated to tPAWT littermates, tPANull mice had similar perfusion deficits, but less severe brain infarcts. In the thrombotic stroke model, homo- and hetero-typic parabionts did not differ in the extent of brain damages and did not differentially recanalize and reperfuse. Together, our data reveal that during thromboembolic stroke, endogenous circulating tPA from endothelial cells sustains a spontaneous recanalization and reperfusion of the tissue, thus, limiting the extension of ischemic lesions. In this context, the impact of endogenous parenchymal tPA is limited.

Serpin peptidase inhibitor, clade E, member 2 in physiology and pathology: recent advancements.

Serine protease inhibitors (serpins) are the most numerous and widespread multifunctional protease inhibitor superfamily and are expressed by all eukaryotes. Serpin E2 (serpin peptidase inhibitor, clade E, member 2), a member of the serine protease inhibitor superfamily is a potent endogenous thrombin inhibitor, mainly found in the extracellular matrix and platelets, and expressed in numerous organs and secreted by many cell types. The multiple functions of serpin E2 are mainly mediated through regulating urokinase-type plasminogen activator (uPA, also known as PLAU), tissue-type plasminogen activator (tPA, also known as PLAT), and matrix metalloproteinase activity, and include hemostasis, cell adhesion, and promotion of tumor metastasis. The importance serpin E2 is clear from its involvement in numerous physiological and pathological processes. In this review, we summarize the structural characteristics of the Serpin E2 gene and protein, as well as its roles physiology and disease.