CORM-2 inhibits intracerebral hemorrhage-mediated inflammation

Red light-induced localized release of carbon monoxide for alleviating postoperative cognitive dysfunction

Inflammation within the central nervous system (CNS), which may be triggered by surgical trauma, has been implicated as a significant factor contributing to postoperative cognitive dysfunction (POCD). The relationship between mitigating inflammation at peripheral surgical sites and its potential to attenuate the CNS inflammatory response, thereby easing POCD symptoms, remains uncertain. Notably, carbon monoxide (CO), a gasotransmitter, exhibits pronounced anti-inflammatory effects. Herein, we have developed carbon monoxide-releasing micelles (CORMs), a nanoparticle that safely and locally liberates CO upon exposure to 650 nm light irradiation. In a POCD mouse model, treatment with CORMs activated by light (CORMs + hv) markedly reduced the concentrations of interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α) in both the peripheral blood and the hippocampus, alongside a decrease in ionized calcium-binding adapter molecule 1 in the hippocampal CA1 region. Furthermore, CORMs + hv treatment diminished Evans blue extravasation, augmented the expression of tight junction proteins zonula occludens-1 and occludin, enhanced neurocognitive functions, and fostered fracture healing. Bioinformatics analysis and experimental validation has identified Htr1b and Trhr as potential key regulators in the neuroactive ligand-receptor interaction signaling pathway implicated in POCD. This work offers new perspectives on the mechanisms driving POCD and avenues for therapeutic intervention.

A "turn-on" red cyclometalated iridium (III) complex for long-term tracking the diffusion of CORM-2 in cells and zebrafish

Transition metal carbonyl compound of CO releasing molecules (CORMs) are widely used to treat arthritis, tumor and immune. They play a physiological role by directly acting on target tissues to release CO for disease treatment without matrix metabolism after dissolution. It is important to track the level and diffusion process of CORMs in vivo to control CO dose and distribution, facilitating to understand the roles of CORMs in disease treatment. Herein, we designed two red ring Ir1/2 complexes with a large stokes shift. Both Ir1 and Ir2 complexes probes can sensitively and selectively respond to CORM-2. The probe Ir1 exhibits rapid reaction with CORM-2 in Phosphate Buffered Saline within 1 min, showing a detection limitation of 0.13 μM and manifesting a linear relationship with the CORM-2 concentration from 0 to 70 μM at λem = 618 nm. Due to low toxicity even after 12 h exposure and fluorescence stability, this probe has been successfully used for continuous tracking the diffusion process of CORM-2 in living cells for up to 60 min and visualizing CORM-2 distribution in zebrafish. Additionally, this probe showed a good capacity for deep penetration (126 μm), suggesting the potential in detecting CORM-2 in living tissues.

Establishment of a rat model of severe spontaneous intracerebral hemorrhage

Background

Severe intracerebral hemorrhage (ICH) is the most devastating subtype of stroke resulting in high mortality and disability. At present, the development of targeted treatments to minimize the high morbidity and mortality is limited partly due to the lack of a severe ICH animal model. In this study, we aimed to establish an accurate severe ICH model in rats and examine the pathological and physiological changes associated with ICH.

Methods

A rat model of severe ICH model was established by intrastriatal injection of autologous blood using different blood volumes (ICH 100 µL group, ICH 130 µL group, ICH 160 µL group, ICH 170 µL group, and ICH 180 µL group). The mortality was assessed during the 28-day post-ICH period. Short- and long-term neurological deficits were evaluated using the Longa method, foot fault, falling latency, and Morris water maze tests. Brain water content, hematoma volume, hemoglobin content, and magnetic resonance imaging were assessed to determine the extent of brain injury. Immunofluorescence staining was conducted to examine microglial activation and neuronal apoptosis. Hematoxylin and eosin (H&E) staining, lung water content, and western blotting were used to assess lung injury following ICH.

Results

The mortality of ICH rats increased significantly with an increase in autologous blood injection. The 28-day mortality in the 100 µL, 130 µL, 160 µL, 170 µL, and 180 µL ICH groups were 5%, 20%, 40%, 75%, and 100%, respectively. A significantly higher 28-day mortality was observed in the ICH 160 µL group compared to the ICH 100 µL group. The ICH 160 µL group exhibited significantly increased neurological deficits, brain edema, hematoma volume, and hemoglobin content compared to the sham group. Compared with the sham operation group, the activation of microglia and neuronal death in ICH 160 µL rats increased. The use of H&E staining and western blotting demonstrated that disruption of the intra-alveolar structure, alveolar edema, and infiltration of inflammatory cells and cytokines into the lung tissue were more severe in the ICH 160 µL group than the sham group.

Conclusions

A severe ICH model in rats was successfully established using an injection of autologous blood at a volume of 160 µL. This model may provide a valuable tool to examine the pathological mechanisms and potential therapeutic interventions of severe ICH.

Association between platelet-lymphocyte ratio and 90-day mortality in patients with intracerebral hemorrhage: data from the MIMIC-III database

Background

Recent evidence suggested that platelet-lymphocyte ratio (PLR) may play a role in the pathophysiology of intracerebral hemorrhage (ICH), but the results are controversial. This study aimed to explore the relationship between PLR and mortality in patients with ICH.

Methods

All data were extracted from the Medical Information Mart for Intensive Care (MIMIC) III database. The study outcome was 90-day mortality. Multivariable Cox regression analyses were used to calculate the adjusted hazard ratio (HR) with a 95% confidence interval (CI), and curve-fitting (restricted cubic spline) was used to assess the non-linear relationship.

Results

Of 1,442 patients, 1,043 patients with ICH were included. The overall 90-day mortality was 29.8% (311/1,043). When PLR was assessed in quartiles, the risk of 90-day mortality for ICH was lowest for quartile 2 (120.9 to <189.8: adjusted HR, 0.67; 95% CI: 0.48-0.93; P = 0.016), compared with those in quartile 1 (<120.9). Consistently in the threshold analysis, for every 1 unit increase in PLR, there was a 0.6% decrease in the risk of 90-day mortality for ICH (adjusted HR, 0.994; 95% CI: 0.988-0.999) in those with PLR <145.54, and a 0.2% increase in 90-day mortality (adjusted HR, 1.002; 95% CI: 1.000-1.003) in participants with PLR ≥145.54.

Conclusion

There was a non-linear relationship between PLR and 90-day mortality for patients with ICH, with an inflection point at 145.54 and a minimal risk at 120.9 to <189.8 of PLR.

Carbon Monoxide Therapy Using Hybrid Carbon Monoxide-Releasing/Nrf2-Inducing Molecules through a Neuroprotective Lens

Carbon monoxide (CO) has long been known for its toxicity. However, in recent decades, new applications for CO as a therapeutic compound have been proposed, and multiple forms of CO therapy have since been developed and studied. Previous research has found that CO has a role as a gasotransmitter and promotes anti-inflammatory and antioxidant effects, making it an avenue of interest for medicine. Such effects are possible because of the Nrf2/HO1 pathway, which has become a target for therapy development because its activation also leads to CO release. Currently, different forms of treatment involving CO include inhaled CO (iCO), carbon monoxide-releasing molecules (CORMs), and hybrid carbon monoxide-releasing molecules (HYCOs). In this article, we review the progression of CO studies to develop possible therapies, the possible mechanisms involved in the effects of CO, and the current forms of therapy using CO.