-
PLoS Pathogens Jun 2024COVID-associated coagulopathy seemly plays a key role in post-acute sequelae of SARS- CoV-2 infection. However, the underlying pathophysiological mechanisms are poorly...
COVID-associated coagulopathy seemly plays a key role in post-acute sequelae of SARS- CoV-2 infection. However, the underlying pathophysiological mechanisms are poorly understood, largely due to the lack of suitable animal models that recapitulate key clinical and pathological symptoms. Here, we fully characterized AC70 line of human ACE2 transgenic (AC70 hACE2 Tg) mice for SARS-CoV-2 infection. We noted that this model is highly permissive to SARS-CoV-2 with values of 50% lethal dose and infectious dose as ~ 3 and ~ 0.5 TCID50 of SARS-CoV-2, respectively. Mice infected with 105 TCID50 of SARS-CoV-2 rapidly succumbed to infection with 100% mortality within 5 days. Lung and brain were the prime tissues harboring high viral titers, accompanied by histopathology. However, viral RNA and inflammatory mediators could be detectable in other organs, suggesting the nature of a systemic infection. Lethal challenge of AC70 hACE2 Tg mice caused acute onset of leukopenia, lymphopenia, along with an increased neutrophil-to-lymphocyte ratio (NLR). Importantly, infected animals recapitulated key features of COVID-19-associated coagulopathy. SARS-CoV-2 could induce the release of circulating neutrophil extracellular traps (NETs), along with activated platelet/endothelium marker. Immunohistochemical staining with anti-platelet factor-4 (PF4) antibody revealed profound platelet aggregates especially within blocked veins of the lungs. We showed that acute SARS-CoV-2 infection triggered a hypercoagulable state coexisting with ill-regulated fibrinolysis. Finally, we highlighted the potential role of Annexin A2 (ANXA2) in fibrinolytic failure. ANXA2 is a calcium-dependent phospholipid-binding protein that forms a heterotertrameric complexes localized at the extracellular membranes with two S100A10 small molecules acting as a co-receptor for tissue-plasminogen activator (t-PA), tightly involved in cell surface fibrinolysis. Thus, our results revealing elevated IgG type anti-ANXA2 antibody production, downregulated de novo ANXA2/S100A10 synthesis, and reduced ANXA2/S100A10 association in infected mice, this protein might serve as druggable targets for development of antithrombotic and/or anti-fibrinolytic agents to attenuate pathogenesis of COVID-19.
PubMed: 38913740
DOI: 10.1371/journal.ppat.1011777 -
Cureus May 2024A hemodialysis tunneled catheter is one option for vascular access used with hemodialysis patients; however, catheter complications such as thrombosis are still...
INTRODUCTION
A hemodialysis tunneled catheter is one option for vascular access used with hemodialysis patients; however, catheter complications such as thrombosis are still inevitable. To prevent thrombosis formation, a catheter-locking solution is instilled between dialysis sessions. Heparin is used as a default locking solution in our Hemodialysis Care Project centers, while a recombinant tissue plasminogen activator (rt-PA) such as alteplase is used to treat suspected catheter thrombosis. This study aimed to identify the clinical factors, catheter brands, and hemodialysis variables that influence the choice of use for alteplase versus heparin, for those patients with tunneled catheters, and reduce overprescribing of high-alert medication alteplase.
METHODS
A retrospective medical chart review study was conducted involving 230 patients with tunneled catheters; the first group of 133 patients used alteplase regularly three times a week, while the second group of 97 patients completed at least one year using the same catheter access with heparin lock only.
RESULTS
Multivariate logistic regression and logistic regression analysis showed a significant association (p < 0.05) between different variables. Results suggest that overweight and hyperlipidemia patients are more likely to use alteplase. Patients using brand-name catheters such as Hemostar/Vas-cath (BD, Franklin Lakes, NJ) are less likely to use heparin than those using Medcomp catheters (Medcomp, Yuma, AZ). In addition, patients having a history of angioplasty would be less likely to have heparin than no angioplasty. Moreover, if the patient's fluid removal were equal to or less than 2 kg, they would be more likely to use heparin and vice versa.
CONCLUSION
The study postulates that identified variables affect whether alteplase or heparin is used in hemodialysis tunneled catheters, and may be useful to increase awareness, improve practices, or judiciously control the use of alteplase within Saudi Arabia and globally.
PubMed: 38910780
DOI: 10.7759/cureus.60817 -
The Journal of Reproduction and... Jun 2024Understanding how stress hormones induce apoptosis in oviductal epithelial cells (OECs) and mural granulosa cells (MGCs) can reveal the mechanisms by which female stress...
Understanding how stress hormones induce apoptosis in oviductal epithelial cells (OECs) and mural granulosa cells (MGCs) can reveal the mechanisms by which female stress impairs embryonic development and oocyte competence. A recent study showed that tissue plasminogen activator (tPA) ameliorates corticosterone-induced apoptosis in MGCs and OECs by acting on its receptors low-density lipoprotein receptor-related protein 1 (LRP1) and Annexin A2 (ANXA2), respectively. However, whether tPA is involved in corticotropin-releasing hormone (CRH)-induced apoptosis and whether it uses the same or different receptors to inhibit apoptosis induced by different hormones in the same cell type remains unknown. This study showed that CRH triggered apoptosis in both OECs and MGCs and significantly downregulated tPA expression. Moreover, tPA inhibits CRH-induced apoptosis by acting on ANXA2 in both OECs and MGCs. While ANXA2 inhibits apoptosis via phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling, LRP1 reduces apoptosis via mitogen-activated protein kinase (MAPK) signaling. Thus, tPA used the same receptor to inhibit CRH-induced apoptosis in both OECs and MGCs, however used different receptors to inhibit corticosterone-induced apoptosis in MGCs and OECs. These data helps understand the mechanism by which female stress impairs embryo/oocyte competence and proapoptotic factors trigger apoptosis in different cell types.
PubMed: 38910127
DOI: 10.1262/jrd.2024-028 -
Thrombosis Research Jun 2024Spontaneous echo contrast (SEC) and left atrial appendage thrombus (LAAT) increase the risk of stroke and its severity in patients with atrial fibrillation (AF)....
INTRODUCTION
Spontaneous echo contrast (SEC) and left atrial appendage thrombus (LAAT) increase the risk of stroke and its severity in patients with atrial fibrillation (AF). Formation of denser fibrin networks and impaired fibrinolysis are associated with stroke risk in AF. This study investigated whether the prothrombotic fibrin clot phenotype characterizes patients with SEC/LAAT.
METHODS
We studied 139 anticoagulated patients with AF (median age, 70 years), who underwent transesophageal echocardiography (TEE). SEC and LAAT were recorded. We assessed plasma fibrin clot properties, i.e. permeability (K) and clot lysis time (CLT), von Willebrand Factor (vWF) antigen, endogenous thrombin potential (ETP), proteins involved in thrombosis and fibrinolysis, as well as plasma carbonylated protein content (PC).
RESULTS
SEC/LAAT was identified in 36 subjects (25.9 %) and was associated with heart failure (HF), AF duration, higher CHADSVASc score, N-terminal prohormone of brain natriuretic peptide, and growth differentiation factor 15. Patients with SEC/LAAT had lower K (-15 %) and prolonged CLT (+19 %), along with higher fibrinogen (+24 %), ETP (+3 %), and plasminogen activator inhibitor-1 antigen (+16 %) compared with the remainder. Thrombin-activatable fibrinolysis inhibitor antigen, plasminogen, α - antiplasmin, and tissue plasminogen activator antigen were similar between the two groups. PC content was 50 % higher in SEC/LAAT and correlated with Ks (r = -0.47, p < 0.001) and CLT (r = 0.40, p < 0.001). On multivariate analysis, Ks, CLT, and PC levels, along with HF, remained independently associated with SEC/LAAT.
CONCLUSIONS
We demonstrated a formation of denser and poorly lysable fibrin networks in AF patients with SEC/LAAT despite anticoagulation. We suggest that this phenomenon is in part related to enhanced oxidative stress.
PubMed: 38908317
DOI: 10.1016/j.thromres.2024.109065 -
International Journal of Stroke :... Jun 2024Recombinant human prourokinase (rhPro-UK) is a specific plasminogen activator, which has been approved to treat acute myocardial infarction in China.
RhPro-UK in acute ischemic stroke within 4.5 hours of stroke onset trial-2(The PROST-2 study): Rationale and design of a multicenter, prospective, randomized, open-label, blinded-endpoint, controlled phase 3 non-inferiority trial.
BACKGROUND
Recombinant human prourokinase (rhPro-UK) is a specific plasminogen activator, which has been approved to treat acute myocardial infarction in China.
AIM
This phase III trial aimed to further demonstrate the efficacy and safety of rhPro-UK in patients with acute ischemic stroke (AIS) within 4.5 hours of symptom onset.
METHODS AND DESIGN
RhPro-UK in AIS within 4.5 hours of stroke onset trial-2 (PROST-2) is a multicenter, prospective randomized, open-label, blinded end-point, non-inferiority, recombinant tissue plasminogen activator (rt-PA)-controlled, phase 3 trial. A total of 1,552 patients who are eligible for intravenous thrombolytic therapy from 72 clinical sites will be randomly assigned to receive either rhPro-UK 35 mg (15 mg bolus+ 20 mg infusion/30 minutes) or rt-PA 0.9 mg/kg (10% bolus +90% infusion/1 hour).
STUDY OUTCOMES
The primary outcome is the proportion of patients with a modified Rankin Scale (mRS) score of 0-1 at 90 days. Secondary efficacy outcomes include the proportion of patients with mRS score of 0-2, the distribution of mRS, self-care ability in daily life on the Barthel Index at 90 days, the proportion of subjects with ≥ 4 points decrease in National Institutes of Health Stroke Scale (NIHSS) score or NIHSS score ≤ 1 from baseline at 24 hours and 7 days after treatment. Safety outcomes are symptomatic intracranial hemorrhage (sICH) and major systematic bleeding within 7 days as well as death from all causes within 90 days.
DISCUSSION
The results from the PROST-2 trial will comprehensively elucidate the efficacy and safety profile of rhPro-UK as a potential alternative agent for stroke thrombolysis.
CLINICAL TRIAL REGISTRATION
URL: http://www.clinicaltrials.gov. Unique identifier: NCT05700591.
PubMed: 38907679
DOI: 10.1177/17474930241265654 -
Alzheimer's & Dementia : the Journal of... Jun 2024Amyloid beta (Aβ) impairs the cerebral blood flow (CBF) increase induced by neural activity (functional hyperemia). Tissue plasminogen activator (tPA) is required for...
INTRODUCTION
Amyloid beta (Aβ) impairs the cerebral blood flow (CBF) increase induced by neural activity (functional hyperemia). Tissue plasminogen activator (tPA) is required for functional hyperemia, and in mouse models of Aβ accumulation tPA deficiency contributes to neurovascular and cognitive impairment. However, it remains unknown if tPA supplementation can rescue Aβ-induced neurovascular and cognitive dysfunction.
METHODS
Tg2576 mice and wild-type littermates received intranasal tPA (0.8 mg/kg/day) or vehicle 5 days a week starting at 11 to 12 months of age and were assessed 3 months later.
RESULTS
Treatment of Tg2576 mice with tPA restored resting CBF, prevented the attenuation in functional hyperemia, and improved nesting behavior. These effects were associated with reduced cerebral atrophy and cerebral amyloid angiopathy, but not parenchymal amyloid.
DISCUSSION
These findings highlight the key role of tPA deficiency in the neurovascular and cognitive dysfunction associated with amyloid pathology, and suggest potential therapeutic strategies involving tPA reconstitution.
HIGHLIGHTS
Amyloid beta (Aβ) induces neurovascular dysfunction and impairs the increase of cerebral blood flow induced by neural activity (functional hyperemia). Tissue plasminogen activator (tPA) deficiency contributes to the neurovascular and cognitive dysfunction caused by Aβ. In mice with florid amyloid pathology intranasal administration of tPA rescues the neurovascular and cognitive dysfunction and reduces brain atrophy and cerebral amyloid angiopathy. tPA deficiency plays a crucial role in neurovascular and cognitive dysfunction induced by Aβ and tPA reconstitution may be of therapeutic value.
PubMed: 38899570
DOI: 10.1002/alz.13878 -
JOR Spine Jun 2024Numerous investigations have suggested links between circulating inflammatory proteins (CIPs) and spinal degenerative diseases (SDDs), but causality has not been proven....
BACKGROUND
Numerous investigations have suggested links between circulating inflammatory proteins (CIPs) and spinal degenerative diseases (SDDs), but causality has not been proven. This study used Mendelian randomization (MR) to investigate the causal associations between 91 CIPs and cervical spondylosis (CS), prolapsed disc/slipped disc (PD/SD), spinal canal stenosis (SCS), and spondylolisthesis/spondylolysis.
METHODS
Genetic variants data for CIPs and SDDs were obtained from the genome-wide association studies (GWAS) database. We used inverse variance weighted (IVW) as the primary method, analyzing the validity and robustness of the results through pleiotropy and heterogeneity tests and performing reverse MR analysis to test for reverse causality.
RESULTS
The IVW results with Bonferroni correction indicated that beta-nerve growth factor (β-NGF), C-X-C motif chemokine 6 (CXCL6), and interleukin-6 (IL-6) can increase the risk of CS. Fibroblast growth factor 19 (FGF19), sulfotransferase 1A1 (SULT1A1), and tumor necrosis factor-beta (TNF-β) can increase PD/SD risk, whereas urokinase-type plasminogen activator (u-PA) can decrease the risk of PD/SD. FGF19 and TNF can increase SCS risk. STAM binding protein (STAMBP) and T-cell surface glycoprotein CD6 isoform (CD6 isoform) can increase the risk of spondylolisthesis/spondylolysis, whereas monocyte chemoattractant protein 2 (MCP2) and latency-associated peptide transforming growth factor beta 1 (LAP-TGF-β1) can decrease spondylolisthesis/spondylolysis risk.
CONCLUSIONS
MR analysis indicated the causal associations between multiple genetically predicted CIPs and the risk of four SDDs (CS, PD/SD, SCS, and spondylolisthesis/spondylolysis). This study provides reliable genetic evidence for in-depth exploration of the involvement of CIPs in the pathogenic mechanism of SDDs and provides novel potential targets for SDDs.
PubMed: 38895179
DOI: 10.1002/jsp2.1346 -
The Neurohospitalist Jul 2024Understanding various aspects associated with readmission after acute ischemic stroke (AIS) is an important priority. Our study aims to examine whether 60-day...
BACKGROUND AND PURPOSE
Understanding various aspects associated with readmission after acute ischemic stroke (AIS) is an important priority. Our study aims to examine whether 60-day readmission rates differed among patients with AIS who were treated with different acute reperfusion treatment modalities along with associated clinical factors.
METHODS
This is a retrospective analysis of a continuous cohort of patient with AIS, who received either intravenous recombinant tissue plasminogen activator (IV rtPA), endovascular treatment (EVT) or both, and were discharged alive. Patients readmitted within 60 days were identified as the readmission group. Multivariable logistic regression was used to identify all-cause readmission post-stroke between treatment groups.
RESULTS
The final cohort comprised of 358 patients with AIS receiving IV rtPA only (N = 160), EVT only (N = 106), or both (N = 92). Fifty-six patients were readmitted to the hospital within 60-day follow-up period. The adjusted logistic regression model indicated that compared to patients who received IV tPA only, patients receiving both IV rtPA and EVT had significantly lower odds (OR = .27; 95% CI = .10, .75)) of getting readmitted within 60-day post-discharge from stroke admission.
CONCLUSION
In this sample of AIS hospitalizations, treatment-type was positively associated with 60-day readmission. Future studies are necessary to understand whether treatment-related adverse events, and readmission are avoidable.
PubMed: 38895015
DOI: 10.1177/19418744241232020 -
International Journal of Molecular... May 2024Stress exposure worsens allergic inflammatory diseases substantially. Mast cells (MCs) play a key role in peripheral immune responses to neuroendocrine stress mediators...
Stress exposure worsens allergic inflammatory diseases substantially. Mast cells (MCs) play a key role in peripheral immune responses to neuroendocrine stress mediators such as nerve growth factor (NGF) and substance P (SP). Mast cell proteases (MCPs) and cholinergic factors (Chrna7, SLURP1) were recently described to modulate MC stress response. We studied MCPs and Chrna7/SLURP1 and their interplay in a mouse model for noise induced stress (NiS) and atopic dermatitis-like allergic inflammation (AlD) and in cultured MC lacking Chrna7. We found that the cholinergic stress axis interacts with neuroendocrine stress mediators and stress-mediator cleaving enzymes in AlD. SP-cleaving mMCP4+ MC were upregulated in AlD and further upregulated by stress in NiS+AlD. Anti-NGF neutralizing antibody treatment blocked the stress-induced upregulation in vivo, and mMCP4+ MCs correlated with measures of AlD disease activity. Finally, high mMCP4 production in response to SP depended on Chrna7/SLURP1 in cultured MCs. In conclusion, mMCP4 and its upstream regulation by Chrna7/SLURP1 are interesting novel targets for the treatment of allergic inflammation and its aggravation by stress.
Topics: Animals; Mast Cells; Dermatitis, Atopic; Mice; Disease Models, Animal; Skin; alpha7 Nicotinic Acetylcholine Receptor; Inflammation; Peptide Hydrolases; Urokinase-Type Plasminogen Activator; Substance P; Stress, Physiological; Mice, Inbred C57BL; Nerve Growth Factor
PubMed: 38891925
DOI: 10.3390/ijms25115738 -
The New England Journal of Medicine Jun 2024Alteplase is the standard agent used in early reperfusion therapy, but alternative thrombolytic agents are needed. The efficacy and safety of reteplase as compared with... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
BACKGROUND
Alteplase is the standard agent used in early reperfusion therapy, but alternative thrombolytic agents are needed. The efficacy and safety of reteplase as compared with alteplase in patients with acute ischemic stroke are unclear.
METHODS
We randomly assigned patients with ischemic stroke within 4.5 hours after symptom onset in a 1:1 ratio to receive intravenous reteplase (a bolus of 18 mg followed 30 minutes later by a second bolus of 18 mg) or intravenous alteplase (0.9 mg per kilogram of body weight; maximum dose, 90 mg). The primary efficacy outcome was an excellent functional outcome, defined as a score of 0 or 1 on the modified Rankin scale (range, 0 [no neurologic deficit, no symptoms, or completely recovered] to 6 [death]) at 90 days. The primary safety outcome was symptomatic intracranial hemorrhage within 36 hours after symptom onset.
RESULTS
A total of 707 patients were assigned to receive reteplase, and 705 were assigned to receive alteplase. An excellent functional outcome occurred in 79.5% of the patients in the reteplase group and in 70.4% of those in the alteplase group (risk ratio, 1.13; 95% confidence interval [CI], 1.05 to 1.21; P<0.001 for noninferiority and P = 0.002 for superiority). Symptomatic intracranial hemorrhage within 36 hours after disease onset was observed in 17 of 700 patients (2.4%) in the reteplase group and in 14 of 699 (2.0%) of those in the alteplase group (risk ratio, 1.21; 95% CI, 0.54 to 2.75). The incidence of any intracranial hemorrhage at 90 days was higher with reteplase than with alteplase (7.7% vs. 4.9%; risk ratio, 1.59; 95% CI, 1.00 to 2.51), as was the incidence of adverse events (91.6% vs. 82.4%; risk ratio, 1.11; 95% CI, 1.03 to 1.20).
CONCLUSIONS
Among patients with ischemic stroke within 4.5 hours after symptom onset, reteplase was more likely to result in an excellent functional outcome than alteplase. (Funded by China Resources Angde Biotech Pharma and others; RAISE ClinicalTrials.gov number, NCT05295173.).
Topics: Humans; Tissue Plasminogen Activator; Male; Fibrinolytic Agents; Female; Aged; Middle Aged; Ischemic Stroke; Recombinant Proteins; Intracranial Hemorrhages; Aged, 80 and over
PubMed: 38884332
DOI: 10.1056/NEJMoa2400314