Red Blood Cell Microparticles Limit Hematoma Growth in Intracerebral Hemorrhage

Red cell microparticles produced using high-pressure extrusion enhance both primary and secondary hemostasis

BACKGROUND

Current therapies to treat excessive bleeding are associated with significant complications, which may outweigh their benefits. Red blood cell-derived microparticles (RMPs) are a promising hemostatic agent. Previous studies demonstrated that they reduce bleeding in animal models, correct coagulation defects in patient blood, and have an excellent safety profile. However, their exact mechanism of action is not known. We investigated the potential role of RMPs on primary and secondary hemostasis.

METHODS

To evaluate the effects of RMPs, prepared using high-pressure extrusion, on primary hemostasis, we employed platelet aggregometry with platelet inhibitors, eptifibatide, and ticagrelor, with and without RMPs. To evaluate their effects on secondary hemostasis, we employed thromboelastography with plasma deficient in factors VII, VIII, IX, XI, and XII with and without RMPs.

RESULTS

We found that RMPs significantly increased collagen-induced platelet aggregation. However, there were no significant differences with and without RMP in the presence of the platelet inhibitors, indicating that RMPs may work through these receptors, either directly or indirectly. For secondary hemostasis, RMPs significantly decreased clotting times for plasma deficient in factors VII, VIII, IX, and XI but not in XII.

CONCLUSIONS

Our results indicate that RMPs enhance primary hemostasis and both pathways of secondary hemostasis.

Platelet Membrane-Coated Curcumin-PLGA Nanoparticles Promote Astrocyte-Neuron Transdifferentiation for Intracerebral Hemorrhage Treatment

Intracerebral hemorrhage (ICH) is a hemorrhagic disease with high mortality and disability rates. Curcumin is a promising drug for ICH treatment due to its multiple biological activities, but its application is limited by its poor watersolubility and instability. Herein, platelet membrane-coated curcumin polylactic-co-glycolic acid (PLGA) nanoparticles (PCNPs) are prepared to achieve significantly improved solubility, stability, and sustained release of curcumin. Fourier transform infrared spectra and X-ray diffraction assays indicate good encapsulation of curcumin within nanoparticles. Moreover, it is revealed for the first time that curcumin-loaded nanoparticles can not only suppress hemin-induced astrocyte proliferation but also induce astrocytes into neuron-like cells in vitro. PCNPs are used to treat rat ICH by tail vein injection, using in situ administration as control. The results show that PCNPs are more effective than curcumin-PLGA nanoparticles in concentrating on hemorrhagic lesions, inhibiting inflammation, suppressing astrogliosis, promoting neurogenesis, and improving motor functions. The treatment efficacy of intravenously administered PCNPs is comparable to that of in situ administration, indicating a good targeting effect of PCNPs on the hemorrhage site. This study provides a potent treatment for hemorrhagic injuries and a promising solution for efficient delivery of water-insoluble drugs using composite materials of macromolecules and cell membranes.

Cerebral Amyloid Angiopathy: An Undeniable Small Vessel Disease

Cerebral amyloid angiopathy (CAA) has been proven to be the most common pathological change in cerebral small vessel disease except arteriosclerosis. In recent years, with the discovery of imaging technology and new imaging markers, the diagnostic rate of CAA has greatly improved. CAA plays an important role in non-hypertensive cerebral hemorrhage and cognitive decline. This review comprehensively describes the etiology, epidemiology, pathophysiological mechanisms, clinical features, imaging manifestations, imaging markers, diagnostic criteria, and treatment of CAA to facilitate its diagnosis and treatment and reduce mortality.

Red Blood Cell-Derived Extracellular Vesicles: An Overview of Current Research Progress, Challenges, and Opportunities

Red blood cell-derived extracellular vesicles (RBC EVs) are small, spherical fragments released from red blood cells. These vesicles, similar to EVs derived from other cell types, are crucial for intercellular communication processes and have been implicated in various physiological and pathological processes. The diagnostic and therapeutic potential of RBC EVs has garnered increasing attention in recent years, revealing their valuable role in the field of medicine. In this review, we aim to provide a comprehensive analysis of the current research status of RBC EVs. We summarize existing studies and highlight the progress made in understanding the characteristics and functions of RBC EVs, with a particular focus on their biological roles in different diseases. We also discuss their potential utility as diagnostic and prognostic biomarkers in diseases and as vectors for drug delivery. Furthermore, we emphasize the need for further research to achieve selective purification of RBC EVs and unravel their heterogeneity, which will allow for a deeper understanding of their diverse functions and exploration of their potential applications in diagnostics and therapeutics.

Red Cell Microparticles Suppress Hematoma Growth Following Intracerebral Hemorrhage in Chronic Nicotine-Exposed Rats

Spontaneous intracerebral hemorrhage (sICH) is a disabling stroke sub-type, and tobacco use is a prominent risk factor for sICH. We showed that chronic nicotine exposure enhances bleeding post-sICH. Reduction of hematoma growth is a promising effective therapy for sICH in smoking subjects. Red-blood-cell-derived microparticles (RMPs) are hemostatic agents that limit hematoma expansion following sICH in naïve rats. Considering the importance of testing the efficacy of experimental drugs in animal models with a risk factor for a disease, we tested RMP efficacy and the therapeutic time window in limiting hematoma growth post-sICH in rats exposed to nicotine. Young rats were chronically treated with nicotine using osmotic pumps. sICH was induced in rats using an injection of collagenase in the right striatum. Vehicle/RMPs were administered intravenously. Hematoma volume and neurological impairment were quantified ≈24 h after sICH. Hematoma volumes in male and female nicotine-exposed rats that were treated with RMPs at 2 h post-sICH were significantly lower by 26 and 31% when compared to their respective control groups. RMP therapy was able to limit hematoma volume when administered up to 4.5 h post-sICH in animals of both sexes. Therefore, RMPs may limit hematoma growth in sICH patients exposed to tobacco use.

Reductions in extracellular vesicle-associated microRNA-126 levels in coronary blood after acute myocardial infarction: A retrospective study

Background

Acute Myocardial Infarction (AMI) is a kind of cardiovascular disease with high mortality and incidence. Extracellular vesicles (EVs) and microRNA-126 (miR-126) are known to play important role in the development and prognosis of several cardiovascular diseases. Therefore, this study aimed to investigate the changes in Extracellular vesicle (EV)-associated miR-126 levels in the coronary blood of patients with AMI to explore the relationship between miR-126 levels and AMI.

Materials and methods

We analyzed EV-associated miR-126 in the coronary blood of patients with AMI and stable coronary artery disease (SCAD) using quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results

We tested the coronary blood of 20 patients with AMI and 20 with SCAD. The mean age of the patients was 58.8 ± 10.3 years and 32 (80%) were men. We observed that the EV-associated miR-126 levels were lower in patients with AMI [median = 0.13; interquartile range (IQR): 0.08–0.22] than in patients with SCAD (median = 0.37; IQR: 0.26–0.48) (P < 0.001). In addition, the levels of miR-126 were negatively associated with the Thrombolysis in Myocardial Infarction (TIMI) score (r = −0.66, P = 0.001).

Conclusion

Reduction of EV-associated miR-126 levels in the coronary blood of patients with AMI may be involved in acute coronary thrombosis events.