Cerebroprotein hydrolysate injection is involved in promoting long-term angiogenesis, vessel diameter and density after cerebral ischemia in mice

Neuroprotective Effects, Mechanisms of Action and Therapeutic Potential of the Kv7/KCNQ Channel Opener QO-83 in Ischemic Stroke

Ischemic stroke is a worldwide disease with high mortality and morbidity. Kv7/KCNQ channels are key modulators of neuronal excitability and microglia function, and activation of Kv7/KCNQ channels has emerged as a potential therapeutic avenue for ischemic stroke. In the present study, we focused on a new Kv7/KCNQ channel opener QO-83 on the stroke outcomes and its therapeutic potential. Transient or distal middle cerebral artery occlusion model was established with C57 mouse to evaluate the role of QO-83. Solitary dose of QO-83 contributes to the microglia inhibition and fibrotic scar mitigation post stroke. QO83 shows prominent effect on reducing infarction area, alleviating cerebral edema, maintaining blood-brain barrier integrity, and enhancing neurogenesis. Single-nucleus RNA sequencing unveils neuroprotection and specific microglial subclusters influenced by QO-83. More importantly, QO83 shows promise in enhancing survival rates with dose dependence. Notably, these protective effects extend beyond the 4-6 h post-reperfusion window. Additionally, continuous dosing of QO-83 correlates with enhanced cognition. In conclusion, this study highlights QO-83 as a protective agent against ischemic brain injury, showcasing its multifaceted effects and potential as a therapeutic strategy.

Evidence of the "hit and run" characteristics of Cerebroprotein Hydrolysate-I in the treatment of neonatal HIE based on pharmacokinetic and pharmacological studies

Hypoxic ischemic encephalopathy (HIE) is the leading cause of neonatal mortality and disability, but its treatment options are very limited and there is an urgent need to further improve treatment outcomes. The present study aims to reveal the therapeutic effects, action pattern, and potential mechanisms of Cerebroprotein hydrolysate-I (CH-I), a mixture of hydrolyzed peptides and amino acids, for the management of HIE. To simulate the complex pathogenesis of HIE more accurately, we innovatively constructed a "triple hit" neonatal HIE rat model. The efficacy of CH-1 was examined in this model, and it was found that CH-I treatment not only significantly improved the behavior and small molecule metabolism disorders of neonatal HIE rats, but also reduced intracerebral neuronal apoptosis, neuroinflammation, and oxidative stress levels. In addition, the neuroprotective effect of CH-I was also confirmed in the hypoxic oligodendrocyte precursor cell model. We innovatively found that CH-I could reverse myelin damage induced by HIE modeling via activating the Wnt/β-catenin signaling pathway. More importantly, a robust quantitative analysis assay for the main peptides in CH-I was developed based on LC-MS/MS system combining Skyline software. Then the pharmacokinetics of the main peptides was studied based on 'relative exposure approach' combining 'mixed calibration curves' strategy. The transient exposure of peptides in vivo indicated that CH-I should exert neuroprotective effects through the "hit and run" pattern.

Gut microbiota-derived acetate promotes long-term recovery through angiogenesis guided by lymphatic ingrowth in older adults with stroke

Introduction

Ischemic stroke is a leading cause of morbidity and mortality in older adults. Therefore, in this study, we sought to understand the interplay between the microbiota, gut, and brain in the context of stroke in older adults.

Objective

To determine whether gut microbiota from younger individuals promotes recovery through angiogenesis in both elderly stroke patients and aged stroke mice, we explored the changes in gut microbiota and the correlation between short-chain fatty acids (SCFAs) and angiogenesis in the aged stroke population. Then, we altered the gut microbiome in aged mice by transplanting microbiota from younger donors before inducing experimental stroke to explore the mechanism by which gut microbiota-derived SCFAs promote angiogenesis.

Methods

Part I: We conducted a single-center, double-blind trial to compare gut microbiota diversity and SCFA levels in fecal samples from older stroke patients with those from younger stroke patients. Additionally, we measured levels of vascular endothelial growth factor (VEGF) and VEGFC levels in plasma to assess their correlation with SCFA levels. Part II: We performed fecal microbiota transplantation (FMT) 3 days before inducing ischemic stroke in aged male mice (16-18) via distal middle cerebral artery occlusion (dMCAO). The FMT was conducted using gut microbiomes from either young donors (2-3 months) or aged donors (16-18 months).

Results

In older stroke patients, gut microbiota diversity was significantly reduced compared to that in younger stroke patients. Furthermore, levels of acetate, a bacterially derived SCFA, were lower and positively correlated with angiogenesis markers (VEGF and VEGF-C). In aged stroke mice, transplantation of young microbiota improved stroke outcomes by promoting angiogenesis, which was facilitated by lymphatic ingrowth into the cortex. This protective effect was linked to gut microbiota-derived acetate, which enhanced lymphangiogenesis by replenishing acetyl coenzyme A.

Conclusions

(a) Gut microbiota-derived acetate promotes angiogenesis post-stroke and (b) lymphatic ingrowth into the cerebral cortex was observed in post-dMCAO mice. These findings suggest that selectively promoting SCFA-producing bacteria, particularly acetate-producers, could be a promising therapeutic strategy to reduce functional impairments in older stroke subjects.

Cerebroprotein hydrolysate-I ameliorates cognitive dysfunction in APP/PS1 mice by inhibiting ferroptosis via the p53/SAT1/ALOX15 signalling pathway

Ferroptosis, an iron-dependent lipid peroxidation-driven cell death pathway, has been linked to the development of Alzheimer's disease (AD). However, the role of ferroptosis in the pathogenesis of AD remains unclear. Cerebroprotein hydrolysate-I (CH-I) is a mixture of peptides with neurotrophic effects that improves cognitive deficits and reduces amyloid burden. The present study investigated the ferroptosis-induced signalling pathways and the neuroprotective effects of CH-I in the brains of AD transgenic mice. Seven-month-old male APPswe/PS1dE9 (APP/PS1) transgenic mice were treated with intraperitoneal injections of CH-I and saline for 28 days. The Morris water maze test was used to assess cognitive function. CH-I significantly improved cognitive deficits and attenuated beta-amyloid (Aβ) aggregation and tau phosphorylation in the hippocampus of APP/PS1 mice. RNA sequencing revealed that multiple genes and pathways, including ferroptosis-related pathways, were involved in the neuroprotective effects of CH-I. The increased levels of lipid peroxidation, ferrous ions, reactive oxygen species (ROS), and altered expression of ferroptosis-related genes (recombinant solute carrier family 7, member 11 (SLC7A11), spermidine/spermine N1-acetyltransferase 1 (SAT1) and glutathione peroxidase 4 (GPX4)) were significantly alleviated after CH-I treatment. Quantitative real-time PCR and western blotting were performed to investigate the expression of key ferroptosis-related genes and the p53/SAT1/arachidonic acid 15-lipoxygenase (ALOX15) signalling pathway. The p53/SAT1/ALOX15 signalling pathway was found to be involved in mediating ferroptosis, and the activation of this pathway was significantly suppressed in AD by CH-I. CH-I demonstrated neuroprotective effects against AD by attenuating ferroptosis and the p53/SAT1/ALOX15 signalling pathway, thus providing new targets for AD treatment.

Salidroside promotes angiogenesis after cerebral ischemia in mice through Shh signaling pathway

AIMS

The purpose of this study was to explore the impacts of salidroside on vascular regeneration, vascular structural changes and long-term neurological recuperation following cerebral ischemia and its possible mechanism.

MAIN METHODS

From Day 1 to Day 28, young male mice with middle cerebral artery blockage received daily doses of salidroside and measured neurological deficits. On the 7th day after stroke, the volume of cerebral infarction was determined using TTC and HE staining. Microvascular density, astrocyte coverage, angiogenesis and the expression of the Shh signaling pathway were detected by IF, qRTPCR and WB at 7, 14 and 28 days after stroke. Changes in blood flow, blood vessel density and diameter from stroke to 28 days were measured by the LSCI and TPMI.

KEY FINDINGS

Compared with the dMACO group, the salidroside treatment group significantly promoted the recovery of neurological function. Salidroside was found to enhance cerebral blood flow perfusion and reduce the infarct on the 7th day after stroke. From the 7th to the 28th day after stroke, salidroside treatment boosted the expression of CD31, CD31+/BrdU+, and GFAP in the cortex around the infarction site. On the 14th day after stroke, salidroside significantly enhanced the width and density of blood vessels. Salidroside increased the expression of histones and genes in the Shh signaling pathway during treatment, and this effect was weakened by the Shh inhibitor Cyclopamine.

SIGNIFICANCE

Salidroside can restore nerve function, improve cerebral blood flow, reduce cerebral infarction volume, increase microvessel density and promote angiogenesis via the Shh signaling pathway.

Microvascular Network Remodeling in the Ischemic Mouse Brain Defined by Light Sheet Microscopy

BACKGROUND

Until now, the analysis of microvascular networks in the reperfused ischemic brain has been limited due to tissue transparency challenges.

METHODS

Using light sheet microscopy, we assessed microvascular network remodeling in the striatum from 3 hours to 56 days post-ischemia in 2 mouse models of transient middle cerebral artery occlusion lasting 20 or 40 minutes, resulting in mild ischemic brain injury or brain infarction, respectively. We also examined the effect of a clinically applicable S1P (sphingosine-1-phosphate) analog, FTY720 (fingolimod), on microvascular network remodeling.

RESULTS

Over 56 days, we observed progressive microvascular degeneration in the reperfused striatum, that is, the lesion core, which was followed by robust angiogenesis after mild ischemic injury induced by 20-minute middle cerebral artery occlusion. However, more severe ischemic injury elicited by 40-minute middle cerebral artery occlusion resulted in incomplete microvascular remodeling. In both cases, microvascular networks did not return to their preischemic state but displayed a chronically altered pattern characterized by higher branching point density, shorter branches, higher unconnected branch density, and lower tortuosity, indicating enhanced network connectivity. FTY720 effectively increased microvascular length density, branching point density, and volume density in both models, indicating an angiogenic effect of this drug.

CONCLUSIONS

Utilizing light sheet microscopy together with automated image analysis, we characterized microvascular remodeling in the ischemic lesion core in unprecedented detail. This technology will significantly advance our understanding of microvascular restorative processes and pave the way for novel treatment developments in the stroke field.

Strategies for mapping protein hydrolysate profiles and pharmacokinetics based on non-targeted proteomics combining skyline-aided quantitative techniques

Numerous works have been focused on the bioactivities of protein hydrolysates (PHs) and their application in food or drug formulations, but their composition and pharmacokinetics have never been addressed due to their complex constitutes, short half-life, extremely low concentrations and lack of authentic standards. The present study aims to develop systematic analytical strategy and technical platform with optimized sample preparation, separation and detection protocols for PHs. Lineal peptides (LPs), extraction of the spleen of healthy pigs or calves, were used as cases. First, solvents with polarity gradients were used to globally extract peptides of LP from biological matrix. Non-targeted proteomics based on a high-resolution MS system was used to establish a reliable qualitative analysis workflow for PHs. Based on the developed approach, 247 unique peptides were identified using NanoLC-Orbitrap-MS/MS, and then further verified on the MicroLC-Q-TOF/MS system. In the quantitative analysis workflow, Skyline software was used to predict and optimize the LC-MS/MS detection parameters of LPs followed by investigating the linearity and precision of the developed analytical assay. Note worthily, we innovatively prepared calibration curves by sequential dilution of LP solution to overcome the bottleneck of lacking authentic standards and complex PH composition. All the peptides exhibited good linearity and precision in biological matrix. The established qualitative and quantitative assays were successfully applied to study the distribution characteristics of LPs in mice, and would be conductive to systematically map the profile and pharmacokinetics of peptides in various PHs in vivo and in vitro.

Hydrogen-Rich Saline-A Novel Neuroprotective Agent in a Mouse Model of Experimental Cerebral Ischemia via the ROS-NLRP3 Inflammasome Signaling Pathway In Vivo and In Vitro

BACKGROUND

Our previous research revealed that inflammation plays an important role in the pathophysiology of cerebral ischemia. The function of the NOD-like receptor protein 3 (NLRP3) inflammasome is to activate the inflammatory process. Recent findings suggest that reactive oxygen species (ROS) are essential secondary messengers that activate the NLRP3 inflammasome. Hydrogen-rich saline (HS) has attracted attention for its anti-inflammatory properties. However, the protective effect and possible mechanism of HSin brain ischemia have not been well elucidated.

METHODS

To test the therapeutic effect of HS, we established a mouse model of distal middle cerebral artery occlusion (dMCAO) and an in vitro model of BV2 cells induced by lipopolysaccharide (LPS). The ROS scavenger N-acetylcysteine (NAC) was used to investigate the underlying mechanisms of HS.

RESULTS

HS significantly improved neurological function, reduced infarct volume, and increased cerebral blood flow in a dMCAO mouse model. ROS, NLRP3, Caspase-1, and IL-1β expression increased after cerebral ischemia, and this was reversed by HS treatment. In BV2 cells, the application of NAC further demonstrated that HS could effectively inhibit the expression of the ROS-activated NLRP3 inflammasome.

CONCLUSIONS

HS, as a novel therapeutic option, could exert protect the brain by inhibiting the activation of the ROS-NLRP3 signaling pathway after cerebral ischemia.

Extracellular Vesicles as Delivery Shippers for Noncoding RNA-Based Modulation of Angiogenesis: Insights from Ischemic Stroke and Cancer

Ischemic stroke and systemic cancer are two of the leading causes of mortality. Hypoxia is a central pathophysiological component in ischemic stroke and cancer, representing a joint medical function. This function includes angiogenesis regulation. Vascular remodeling coupled with axonal outgrowth following cerebral ischemia is critical in improving poststroke neurological functional recovery. Antiangiogenic strategies can inhibit cancer vascularization and play a vital role in impeding cancer growth, invasion, and metastasis. Although there are significant differences in the cause of angiogenesis across both pathophysiological conditions, emerging evidence states that common signaling structures, such as extracellular vesicles (EVs) and noncoding RNAs (ncRNAs), are involved in this context. EVs, heterogeneous membrane vesicles encapsulating proteomic genetic information from parental cells, act as multifunctional regulators of intercellular communication. Among the multifaceted roles in modulating biological responses, exhaustive evidence shows that ncRNAs are selectively sorted into EVs, modulating common specific aspects of cancer development and stroke prognosis, namely, angiogenesis. This review will discuss recent advancements in the EV-facilitated/inhibited progression of specific elements of angiogenesis with a particular concern about ncRNAs within these vesicles. The review is concluded by underlining the clinical opportunities of EV-derived ncRNAs as diagnostic, prognostic, and therapeutic agents.