Guhong Injection Protects Against Apoptosis in Cerebral Ischemia by Maintaining Cerebral Microvasculature and Mitochondrial Integrity Through the PI3K/AKT Pathway

Irisin protects against cerebral ischemia reperfusion injury in a SIRT3-dependent manner

Background

Cerebral ischemia-reperfusion (CIR) injury critically impacts stroke prognosis, yet effective therapeutic strategies remain limited. Irisin, an exercise-induced myokine, exhibits neuroprotective effects against cerebral ischemia. SIRT3, a mitochondrial deacetylase, is similarly implicated in mitigating ischemia-reperfusion injury. Given that irisin exerts protection via AMPK/PGC-1α pathway activation and SIRT3 acts downstream of PGC-1α , we hypothesized that SIRT3 mediates irisin's neuroprotection in CIR injury.

Methods

In vivo cerebral ischemia-reperfusion injury was modeled by inducing transient middle cerebral artery occlusion (MCAO) in mice, while in vitro CIR conditions were replicated using oxygen-glucose deprivation (OGD) in PC12 neuronal cultures. To elucidate the mechanistic role of SIRT3, targeted interventions were implemented: SIRT3 expression was silenced via transfection with small interfering RNA (siRNA), and its enzymatic activity was pharmacologically inhibited using 3-TYP, a selective SIRT3 inhibitor. Apoptotic were systematically evaluated through TUNEL staining, Western blot analysis of caspase-3, Bax and Bcl-2. Oxidative stress parameters, including malondialdehyde (MDA) levels and glutathione (GSH) content, were measured using colorimetric assays. Neurological function in mice was quantified using the modified Neurological Severity Score (mNSS).

Results

Our results demonstrated that irisin mitigates apoptosis and oxidative stress by dose-dependently activating SIRT3 signaling. At the optimal dosage, irisin effectively restored SIRT3 expression levels, reduced neuronal damage, and improved neurological recovery in CIR injury models. Notably, the therapeutic effects of irisin were significantly attenuated by 3-TYP, a specific SIRT3 inhibitor. Further validation through in vitro experiments revealed that SIRT3 overexpression synergistically enhanced irisin-mediated protection against OGD-induced injury, whereas SIRT3 knockout substantially diminished its efficacy.

Conclusion

Our data shown that irisin exerted a protective role in CIR injury, at least in part, through SIRT3 activation. This study establishes the irisin/SIRT3 as a novel therapeutic target for ischemic stroke, providing mechanistic insights for future interventions.

Multi-Omics Analysis of the Gut-Brain Axis Elucidates Therapeutic Mechanisms of Guhong Injection in the Treatment of Ischemic Stroke

Guhong injection (GH) is a compound preparation widely utilized in the treatment of cerebrovascular diseases. Accumulating evidence indicates that the gut microbiota is implicated in the development of ischemic stroke (IS). However, although the therapeutic potential of GH in IS may be mediated through the gut microbiota, the intricate relationships among the gut-brain axis, biomarkers, and target proteins remain to be completely explained. A rat model of middle cerebral artery occlusion (MCAO) was utilized to investigate the impact of GH on IS. Our 16S rRNA sequence analysis revealed that GH markedly enhanced the α-diversity of the intestinal microbiome and rectified the imbalance of short-chain fatty acids (SCFAs). Metabolomic analysis indicated that GH reversed 45 biomarkers and 6 disordered metabolic pathways in MCAO rats. Among these, the metabolic pathways of arachidonic acid, α-linolenic acid, fructose, and mannose were closely associated with gut microbiota comprising Lactobacillus modulated by GH. Furthermore, IS-related signaling pathways, including inflammation, autophagy, oxidative stress, and apoptosis, were significantly associated with three gut microbial species influenced by GH. The potential efficacy of GH in the context of IS is mediated through multiple pathways, involving the gut microbiota, SCFAs, biomarkers, and target proteins. This process partly relies on the gut-brain axis.

Fluoxetine-induced downregulation of circMap2k1 signaling cascade to improve neurological function after ischemic stroke

BACKGROUND

Ischemic stroke (IS) is known for its high incidence, disability, and mortality, and there is an urgent need to investigate the pathophysiological mechanisms and develop novel treatment strategies.

OBJECTIVES

We aimed to investigate the mechanisms of the novel circMap2k1/miR-135b-5p/Pidd1 axis in the treatment of IS progression with fluoxetine.

METHODS

The middle cerebral artery occlusion (MCAO) model was done in adult male Sprague-Dawley (SD) rats and followed by fluoxetine treatment and the injection of adeno-associated virus (AAV)-sh-ctr and AAV-sh-circMap2k1 into the bilateral hippocampal tissues of rats. Dual-luciferase reporter gene assay was employed to confirm the binding between miR-135b-5p and Pidd1. Enzyme-linked immunosorbent assay was performed to measure the concentrations of the inflammatory factors TNF-α, IL-6, and IL-1β in the plasma. The role of circMap2k1 in cells was tested by overexpression of circMap2k1. Cell viability was assessed using Cell Counting Kit-8 assay, while apoptosis was measured by flow cytometry.

RESULTS

Knockdown of circMap2k1 enhanced the therapeutic and protective effect of fluoxetine on IS injury in rats. Dual-luciferase reporter gene assay confirmed the targeting of miR-135b-5p to Pidd1. Additionally, fluoxetine deactivated the adsorption of miR-135b-5p by downregulating circMap2k1, and miR-135b-5p further exerted its inhibitory effect on Pidd1 and finally attenuated the inflammatory response caused by microglial polarization after IS. Cell experiments revealed that overexpression of circMap2k1 repressed cell viability and promoted cell apoptosis.

CONCLUSIONS

Fluoxetine downregulated of circMap2k1 was associated ameliorate neurological injury and inflammatory responses induced by microglial polarization after IS. The manuscript is available as a preprint at this link: doi.org/10.21203/rs.3.rs-3209057/v1.

Advances in pathogenesis and treatment of vascular endothelial injury-related diseases mediated by mitochondrial abnormality

Vascular endothelial cells, serving as a barrier between blood and the arterial wall, play a crucial role in the early stages of the development of atherosclerosis, cardiovascular diseases (CVDs), and Alzheimer's disease (AD). Mitochondria, known as the powerhouses of the cell, are not only involved in energy production but also regulate key biological processes in vascular endothelial cells, including redox signaling, cellular aging, calcium homeostasis, angiogenesis, apoptosis, and inflammatory responses. The mitochondrial quality control (MQC) system is essential for maintaining mitochondrial homeostasis. Current research indicates that mitochondrial dysfunction is a significant driver of endothelial injury and CVDs. This article provides a comprehensive overview of the causes of endothelial injury in CVDs, ischemic stroke in cerebrovascular diseases, and AD, elucidating the roles and mechanisms of mitochondria in these conditions, and aims to develop more effective therapeutic strategies. Additionally, the article offers treatment strategies for cardiovascular and cerebrovascular diseases, including the use of clinical drugs, antioxidants, stem cell therapy, and specific polyphenols, providing new insights and methods for the clinical diagnosis and treatment of related vascular injuries to improve patient prognosis and quality of life. Future research should delve deeper into the molecular and mechanistic links between mitochondrial abnormalities and endothelial injury, and explore how to regulate mitochondrial function to prevent and treat CVDs.

Advances of phytotherapy in ischemic stroke targeting PI3K/Akt signaling

The pathogenesis of ischemic stroke is complex, and PI3K/Akt signaling is considered to play a crucial role in it. The PI3K/Akt pathway regulates inflammation, oxidative stress, apoptosis, autophagy, and vascular endothelial homeostasis after cerebral ischemia; therefore, drug research targeting the PI3K/Akt pathway has become the focus of scientists. In this review, we analyzed the research reports of antiischemic stroke drugs targeting the PI3K/Akt pathway in the past two decades. Because of the rich sources of natural products, increasing studies have explored the value of natural compounds, including Flavonoids, Quinones, Alkaloids, Phenylpropanoids, Phenols, Saponins, and Terpenoids, in alleviating neurological impairment and achieved satisfactory results. Herbal extracts and medicinal formulas have been applied in the treatment of ischemic stroke for thousands of years in East Asian countries. These precious clinical experiences provide a new avenue for research of antiischemic stroke drugs. Finally, we summarize and discuss the characteristics and shortcomings of the current research and put forward prospects for further in-depth exploration.

Chemical composition, pharmacology and pharmacokinetic studies of GuHong injection in the treatment of ischemic stroke

GuHong injection is composed of safflower and N-acetyl-L-glutamine. It is widely used in clinical for cerebrovascular diseases, such as ischemic stroke and related diseases. The objective of this review is to comprehensively summarize the most recent information related to GuHong in the treatment of stroke, including chemical composition, clinical studies, potential pharmacological mechanisms and pharmacokinetics. Additionally, it examines possible scientific gaps in current study and aims to provide a reliable reference for future GuHong studies. The systematic review reveals that the chemical composition of safflower in GuHong is more than 300 chemical components in five categories. GuHong injection is primarily used in clinical applications for acute ischemic stroke and related diseases. Pharmacological investigations have indicated that GuHong acts in the early and recovery stages of ischemic stroke by anti-inflammatory, anti-oxidative stress, anti-coagulation, neuroprotective and anti-apoptotic mechanisms simultaneously. Pharmacokinetic studies found that the main exposed substances in rat plasma after GuHong administration are hydroxysafflor yellow A and N-acetyl-L-glutamine, and N-acetyl-L-glutamine could exert its pharmacological effect across the blood-brain barrier. As a combination of Chinese herb and chemical drug, GuHong injection has great value in drug research and clinical treatment, especially for ischemic stroke disease. This article represents a comprehensive and systematic review of existing studies on GuHong injection, including chemical composition, pharmacological mechanism, and pharmacokinetics, which provides reference significance for the clinical treatment of ischemic stroke with GuHong, as well as provides guidance for further study.

Engeletin alleviates cerebral ischemia reperfusion-induced neuroinflammation via the HMGB1/TLR4/NF-κB network

High-mobility group box1 (HMGB1) induces inflammatory injury, and emerging reports suggest that it is critical for brain ischemia reperfusion. Engeletin, a natural Smilax glabra rhizomilax derivative, is reported to possess anti-inflammatory activity. Herein, we examined the mechanism of engeletin-mediated neuroprotection in rats having transient middle cerebral artery occlusion (tMCAO) against cerebral ischemia reperfusion injury. Male SD rats were induced using a 1.5 h tMCAO, following by reperfusion for 22.5 h. Engeletin (15, 30 or 60 mg/kg) was intravenously administered immediately following 0.5 h of ischemia. Based on our results, engeletin, in a dose-dependent fashion, reduced neurological deficits, infarct size, histopathological alterations, brain edema and inflammatory factors, namely, circulating IL-1β, TNF-α, IL-6 and IFN-γ. Furthermore, engeletin treatment markedly reduced neuronal apoptosis, which, in turn, elevated Bcl-2 protein levels, while suppressing Bax and Cleaved Caspase-3 protein levels. Meanwhile, engeletin significantly reduces overall expressions of HMGB1, TLR4, and NF-κB and attenuated nuclear transfer of nuclear factor kappa B (NF-κB) p65 in ischemic cortical tissue. In conclusion, engeletin strongly prevents focal cerebral ischemia via suppression of the HMGB1/TLR4/NF-κB inflammatory network.

Traditional Chinese medicine in treating ischemic stroke by modulating mitochondria: A comprehensive overview of experimental studies

Ischemic stroke has been a prominent focus of scientific investigation owing to its high prevalence, complex pathogenesis, and difficulties in treatment. Mitochondria play an important role in cellular energy homeostasis and are involved in neuronal death following ischemic stroke. Hence, maintaining mitochondrial function is critical for neuronal survival and neurological improvement in ischemic stroke, and mitochondria are key therapeutic targets in cerebral stroke research. With the benefits of high efficacy, low cost, and high safety, traditional Chinese medicine (TCM) has great advantages in preventing and treating ischemic stroke. Accumulating studies have explored the effect of TCM in preventing and treating ischemic stroke from the perspective of regulating mitochondrial structure and function. In this review, we discuss the molecular mechanisms by which mitochondria are involved in ischemic stroke. Furthermore, we summarized the current advances in TCM in preventing and treating ischemic stroke by modulating mitochondria. We aimed to provide a new perspective and enlightenment for TCM in the prevention and treatment of ischemic stroke by modulating mitochondria.

Saquayamycin B1 Suppresses Proliferation, Invasion, and Migration by Inhibiting PI3K/AKT Signaling Pathway in Human Colorectal Cancer Cells

Moromycin B (Mor B), saquayamycin B₁ (Saq B₁), saquayamycin B (Saq B), and landomycin N (Lan N), four angucyclines produced by the marine-derived actinomycete Streptomyces sp., are a class of polyketone compounds containing benzanthracene. Here, the structure–activity relationship of these four compounds was analyzed in human colorectal cancer (CRC) cells. Saq B₁, which showed the strongest cytotoxicity with an IC₅₀ of 0.18–0.84 µM for CRC cells in MTT assays, was employed to test underlying mechanisms of action in SW480 and SW620 cells (two invasive CRC cell lines). Our results showed that Saq B₁ inhibited CRC cell proliferation in a dose- and time-dependent manner. Notably, lower cytotoxicity was measured in normal human hepatocyte cells (QSG-7701). Furthermore, we observed proapoptosis, antimigration, and anti-invasion activities of Saq B₁ in CRC cells. At the same time, the protein and mRNA expression of important markers related to the epithelial–mesenchymal transition (EMT) and apoptosis changed, including N-cadherin, E-cadherin, and Bcl-2, in Saq B₁-treated CRC cells. Surprisingly, the PI3K/AKT signaling pathway was shown to be involved in Saq B₁-induced apoptosis, and in inhibiting invasion and migration. Computer docking models also suggested that Saq B₁ might bind to PI3Kα. Collectively, these results indicate that Saq B₁ effectively inhibited growth and decreased the motor ability of CRC cells by regulating the PI3K/AKT signaling pathway, which provides more possibilities for the development of drugs in the treatment of CRC.

Efficacy of Guhong injection versus Butylphthalide and Sodium Chloride Injection for mild ischemic stroke: A multicenter controlled study

BACKGROUND

Most studies on Guhong injection have involved a single center with a small sample size, and the level of clinical evidence is low.

AIM

To assess the safety and efficacy of Guhong injection for mild ischemic stroke (IS).

METHODS

A total of 399 IS patients treated at six hospitals from August 2018 to August 2019 were retrospectively analyzed. The patients were given Guhong injection (experimental group) or Butylphthalide and Sodium Chloride Injection (control group). Changes in National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores were observed before treatment and at 1, 2, and 3 wk after treatment in each group. The efficacy and safety of Guhong injection for IS were assessed. Other medications taken by the patients were confounding factors for efficacy assessment. These factors were controlled by propensity score matching, and the results were further analyzed based on the matching.

RESULTS

The marked response rates at three follow-up visits were 64.64%, 74.7%, and 66.7% in the experimental group, and 48.26%, 45.4%, and 22.2% in the control group. The marked response rates increased significantly in the experimental group compared with the control group (P < 0.05). The overall response rate at the first visit (days 7 ± 2) did not differ significantly between the two groups, but differed significantly at the second (days 14 ± 2) and third visits (days 21 ± 3) (P < 0.05). The proportion of patients without any symptoms in the experimental group was significant different at the first visit (P < 0.05), but not significantly different at the second visit. The two groups showed no significant difference in the baseline distribution of mRS scores. At the first and second visits, the change in mRS scores was -2 and -1 in the experimental and control groups, respectively, which were significantly different (P < 0.05). After propensity score matching, the overall response rate and marked response rate were 97.29% and 100% in the experimental group (P > 0.05) and 64.0% and 47.7% in the control group (P < 0.05) at the first visit, respectively. The decreased NIHSS scores in the two groups were significant different (P < 0.05). The overall response rate and marked response rate differed significantly between the two groups at the second visit (P < 0.05). There was no significant difference in the incidence of adverse events between the two groups. No severe adverse events occurred in either group.

CONCLUSION

Guhong injection is safe and more effective than Butylphthalide and Sodium Chloride Injection for treatment of IS.

BNIP3 mediates the different adaptive responses of fibroblast-like synovial cells to hypoxia in patients with osteoarthritis and rheumatoid arthritis

Background

Hypoxia is one of the important characteristics of synovial microenvironment in rheumatoid arthritis (RA), and plays an important role in synovial hyperplasia. In terms of cell survival, fibroblast-like synovial cells (FLSs) are relatively affected by hypoxia. In contrast, fibroblast-like synovial cells from patients with RA (RA-FLSs) are particularly resistant to hypoxia-induced cell death. The purpose of this study was to evaluate whether fibroblast-like synovial cells in patients with osteoarthritis (OA-FLSs) and RA-FLSs have the same adaptation to hypoxia.

Methods

CCK-8, flow cytometry and BrdU were used to detect the proliferation of OA-FLSs and RA-FLSs under different oxygen concentrations. Apoptosis was detected by AV/PI, TUNEL and Western blot, mitophagy was observed by electron microscope, laser confocal microscope and Western blot, the state of mitochondria was detected by ROS and mitochondrial membrane potential by flow cytometry, BNIP3 and HIF-1α were detected by Western blot and RT-qPCR. The silencing of BNIP3 was achieved by stealth RNA system technology.

Results

After hypoxia, the survival rate of OA-FLSs decreased, while the proliferation activity of RA-FLSs further increased. Hypoxia induced an increase in apoptosis and inhibition of mitophagy in OA-FLSs, but not in RA-FLSs. Hypoxia led to a more lasting adaptive response. RA-FLSs displayed a more significant increase in the expression of genes transcriptionally regulated by HIF-1α. Interestingly, they showed higher BNIP3 expression than OA-FLSs, and showed stronger mitophagy and proliferation activities. BNIP3 siRNA experiment confirmed the potential role of BNIP3 in the survival of RA-FLSs. Inhibition of BNIP3 resulted in the decrease of cell proliferation, mitophagy and the increase of apoptosis.

Conclusion

In summary, RA-FLSs maintained intracellular redox balance through mitophagy to promote cell survival under hypoxia. The mitophagy of OA-FLSs was too little to maintain the redox balance of mitochondria, resulting in apoptosis. The difference of mitophagy between OA-FLSs and RA-FLSs under hypoxia is mediated by the level of BNIP3 expression.

Rhenium-guanidine complex as photosensitizer: trigger HeLa cell apoptosis through death receptor-mediated, mitochondria-mediated and cell cycle arrest pathways

During the last decades, growing evidence indicates that the photodynamic antitumor activity of transition metal complexes, and Re(I) compounds are potential candidates for photodynamic therapy (PDT). This study reports the synthesis, characterization, and anti-tumor activity of three new Re(I)-guadinium complexes. Cytotoxicity tests reveal that complex Re1 increased cytotoxicity by 145-fold from IC50 > 180 μM in the dark to 1.3 ± 0.7 μM following 10 min of light irradiation (425 nm) in HeLa cells. Further, the mechanism by which Re1 induces apoptosis in the presence or absence of light irradiation was investigated, and results indicate that cell death was caused through different pathways. Upon irradiation, Re1 first accumulates on the cell membrane and interacts with death receptors to activate the extrinsic death receptor-mediated signaling pathway, then is transported into the cell cytoplasm. Most of the intracellular Re1 locates within mitochondria, improving the ROS level, and decreasing MMP and ATP levels, and inducing the activation of caspase-9 and, thus, apoptosis. Subsequently, the residual Re1 can translocate into the cell nucleus, and activates the p53 pathway, causing cell-cycle arrest and eventually cell death.

Guhong Injection Alleviates Cerebral Ischemia-Reperfusion Injury via the PKC/HIF-1α Pathway in Rats

Guhong injection (GHI) is a drug for ischemic stroke created by combining safflower, a traditional Chinese medicine, and aceglutamide, a Western medicine. In this study, we investigated the curative effect of GHI on cerebral ischemia–reperfusion (I/R) injury via the PKC/HIF-1α pathway in rats. Adult male Sprague Dawley rats were randomly divided into seven groups: sham-operated, middle cerebral artery occlusion (MCAO), GHI, nimodipine injection (NMDP), MCAO + LY317615 (PKC inhibitor), GHI + LY317615, and NMDP + LY317615. After establishing an MCAO rat model, we performed neurological deficit testing, 2,3,5-triphenyltetrazolium chloride staining, hematoxylin and eosin (HE) staining, enzyme-linked immunosorbent assay, Western blotting, and q-PCR to detect the brain damage in rats. Compared with the MCAO group, the GHI and GHI + LY317615 group showed neurological damage amelioration as well as decreases in serum hypoxia-inducible factor-1α (HIF-1α), protein kinase C (PKC), and erythropoietin levels; brain HIF-1α and inducible nitric oxide synthase protein expression; and brain HIF-1α and NOX-4 mRNA expression. These effects were similar to those in the positive control groups NMDP and NMDP + LY317615. Thus, our results confirmed GHI can ameliorate cerebral I/R injury in MCAO rats possibly via the PKC/HIF-1α pathway.