Qiangji Jianli Decoction Alleviates Hydrogen Peroxide-Induced Mitochondrial Dysfunction via Regulating Mitochondrial Dynamics and Biogenesis in L6 Myoblasts

Glucagon-Like Peptide-1 Inhibits the Progression of Abdominal Aortic Aneurysm in Mice: The Earlier, the Better

OBJECTIVES

Glucagon-like peptide-1 (GLP-1) has a cardiovascular protective effect by preventing abdominal aortic aneurysm (AAA) formation. However, it is unclear at what point the agent should be administered to achieve the optimal effect. In this study, we aimed to determine whether administering the GLP-1 receptor agonist liraglutide during the earlier stages would more efficiently inhibit AAA progression in mice.

METHODS

Depending on the group, mice were given a daily dose of 300 μg/kg liraglutide for 28 days at 7, 14, and 28 days after aneurysm induction. The morphology of the abdominal aorta was monitored using 7.0 T magnetic resonance imaging (MRI) during the administration of liraglutide. After 28 days of administration, the AAA dilatation ratio was calculated, and histopathological examination was performed. Oxidative stress levels were evaluated by the expression of malondialdehyde (MDA) and matrix metalloproteinases (MMPs). The inflammatory response was also evaluated.

RESULTS

Liraglutide treatment led to a decrease in AAA formation, including a reduction in abdominal aorta expansion, elastin degradation in the elastic laminae, and vascular inflammation caused by leukocyte infiltration. The expression of MDA and the activity of MMPs (MMP-2, MMP-9) also decreased. Notably, administering liraglutide during the early stages resulted in a significant reduction in the dilatation rate of the aortic wall, as well as in MDA expression, leukocyte infiltration, and MMP activity in the vascular wall.

CONCLUSIONS

The GLP-1 receptor agonist liraglutide was found to inhibit AAA progression in mice by exerting anti-inflammatory and antioxidant effects, particularly during the early stages of AAA formation. Therefore, liraglutide may represent a potential pharmacological target for the treatment of AAA.

Astragaloside IV protects against autoimmune myasthenia gravis in rats via regulation of mitophagy and apoptosis

Astragaloside IV (AS‑IV) has various pharmacological effects, including antioxidant and immunoregulatory properties, which can improve myasthenia gravis (MG) symptoms. However, the potential mechanism underlying the effects of AS‑IV on MG remains to be elucidated. The present study aimed to investigate whether AS‑IV has a therapeutic effect on MG and its potential mechanism of action. By subcutaneously immunizing rats with R97‑116 peptide, an experimental autoimmune (EA) MG rat model was established. AS‑IV (40 or 80 mg/kg/day) treatment was then applied for 28 days after modeling. The results demonstrated that AS‑IV significantly ameliorated the weight loss, Lennon score and pathological changes in the gastrocnemius muscle of EAMG rats compared with the model group. Additionally, the levels of acetylcholine receptor antibody (AChR‑Ab) were significantly decreased, whereas mitochondrial function [ATPase and cytochrome c (Cyt‑C) oxidase activities] and ultrastructure were improved in the AS‑IV treated rats. Moreover, the mRNA and protein expression levels of phosphatase and tensin homolog‑induced putative kinase 1, Parkin, LC3II and Bcl‑2, key signaling molecules for mitophagy and apoptosis, were upregulated, whereas the mRNA and protein expression levels of p62, Cyt‑C, Bax, caspase 3 and caspase 9 were downregulated following AS‑IV intervention. In conclusion, AS‑IV may protect against EAMG in a rat model by modulating mitophagy and apoptosis. These findings indicated the potential mechanism underlying the effects of AS‑IV on MG and provided novel insights into treatment strategies for MG.

The mitochondrial quality control system: a new target for exercise therapeutic intervention in the treatment of brain insulin resistance-induced neurodegeneration in obesity

Obesity is a major global health concern because of its strong association with metabolic and neurodegenerative diseases such as diabetes, dementia, and Alzheimer's disease. Unfortunately, brain insulin resistance in obesity is likely to lead to neuroplasticity deficits. Since the evidence shows that insulin resistance in brain regions abundant in insulin receptors significantly alters mitochondrial efficiency and function, strategies targeting the mitochondrial quality control system may be of therapeutic and practical value in obesity-induced cognitive decline. Exercise is considered as a powerful stimulant of mitochondria that improves insulin sensitivity and enhances neuroplasticity. It has great potential as a non-pharmacological intervention against the onset and progression of obesity associated neurodegeneration. Here, we integrate the current knowledge of the mechanisms of neurodegenration in obesity and focus on brain insulin resistance to explain the relationship between the impairment of neuronal plasticity and mitochondrial dysfunction. This knowledge was synthesised to explore the exercise paradigm as a feasible intervention for obese neurodegenration in terms of improving brain insulin signals and regulating the mitochondrial quality control system.

Celastrol Alleviates Mitochondrial Oxidative Stress and Brain Injury After Intracerebral Hemorrhage by Promoting OPA1-Dependent Mitochondrial Fusion

Mitochondrial oxidative stress is one of the characteristics of secondary brain injury (SBI) after intracerebral hemorrhage (ICH), contributing largely to the apoptosis of neurons. Celastrol, a quinone methide triterpene that possesses antioxidant and mitochondrial protective properties, has emerged as a neuroprotective agent. However, the activity of celastrol has not been tested in ICH-induced SBI. In this study, we found that celastrol could effectively alleviate neurological function deficits and reduce brain oedema and neuronal apoptosis caused by ICH. Through electron microscopy, we found that celastrol could significantly attenuate mitochondrial morphology impairment. Therefore, we tested the regulatory proteins of mitochondrial dynamics and found that celastrol could reverse the downwards trend of OPA1 expression after ICH. In view of this, by culturing OPA1-deficient primary neurons and constructing neuron-specific OPA1 conditional knockout mice, we found that the protective effects of celastrol on mitochondrial morphology and function after ICH were counteracted in the absence of OPA1. Further experiments also showed that OPA1 is indispensable for the protective effects of celastrol on ICH-induced secondary brain injury. In summary, we have demonstrated that celastrol is a potential drug for the treatment of ICH and have revealed a novel mechanism by which celastrol exerts its antioxidant effects by promoting OPA1-mediated mitochondrial fusion.

Myasthenia gravis: Molecular mechanisms and promising therapeutic strategies

Myasthenia gravis (MG) is a type of autoimmune disease caused by the blockage of neuromuscular junction transmission owing to the attack of autoantibodies on transmission-related proteins. Related antibodies, such as anti-AChR, anti-MuSK and anti-LRP4 antibodies, can be detected in most patients with MG. Although traditional therapies can control most symptoms, several challenges remain to be addressed, necessitating the development of more effective and safe treatment strategies for MG. With the in-depth exploration on the mechanism and immune targets of MG, effective therapies, especially therapies using biologicals, have been reported recently. Given the important roles of immune cells, cytokines and intercellular interactions in the pathological process of MG, B-cell targeted therapy, T-cell targeted therapy, proteasome inhibitors targeting plasma cell, complement inhibitors, FcRn inhibitors have been developed for the treatment of MG. Although these novel therapies exert good therapeutic effects, they may weaken the immunity and increase the risk of infection in MG patients. This review elaborates on the pathogenesis of MG and discusses the advantages and disadvantages of the strategies of traditional treatment and biologicals. In addition, this review emphasises that combined therapy may have better therapeutic effects and reducing the risk of side effects of treatments, which has great prospects for the treatment of MG. With the deepening of research on immunotherapy targets in MG, novel opportunities and challenges in the treatment of MG will be introduced.

Modified Linggui Zhugan Decoction protects against ventricular remodeling through ameliorating mitochondrial damage in post-myocardial infarction rats

Introduction

Modified Linggui Zhugan Decoction (MLZD) is a Traditional Chinese Medicine prescription developed from Linggui Zhugan Decoction (LZD) that has been used for the clinical treatment of ischemic cardiovascular diseases. However, the cardioprotective mechanism of MLZD against post-myocardial infarction (MI) ventricular remodeling remains unclear.

Methods

We explored the effects of MLZD on ventricular remodeling and their underlying mechanisms, respectively, in SD rats with MI models and in H9c2 cardiomyocytes with oxygen-glucose deprivation (OGD) models. The cardiac structure and function of rats were measured by echocardiography, HE staining, and Masson staining. Apoptosis, inflammation, mitochondrial structure and function, and sirtuin 3 (SIRT3) expression were additionally examined.

Results

MLZD treatment significantly ameliorated cardiac structure and function, and thus reversed ventricular remodeling, compared with the control. Further research showed that MLZD ameliorated mitochondrial structural disruption, protected against mitochondrial dynamics disorder, restored impaired mitochondrial function, inhibited inflammation, and thus inhibited apoptosis. Moreover, the decreased expression level of SIRT3 was enhanced after MLZD treatment. The protective effects of MLZD on SIRT3 and mitochondria, nevertheless, were blocked by 3-TYP, a selective inhibitor of SIRT3.

Discussion

These findings together revealed that MLZD could improve the ventricular remodeling of MI rats by ameliorating mitochondrial damage and its associated apoptosis, which might exert protective effects by targeting SIRT3.

Apolipoprotein A-I mimetic peptides (ApoAI MP) improve oxidative stress and inflammatory responses in Parkinson’s disease mice

Purpose: Parkinson’s disease (PD) is closely associated with oxidative stress and inflammatory situation. Apolipoprotein A-I mimetic peptides (ApoAI MP) have antioxidant and anti-inflammatory properties. We aimed to study the therapeutic effect of ApoAI MP on PD mice, and to explore the related mechanisms.

Methods: PD mice were induced by using 1-methyl-4-phenyl-1,2,3,6-tetrathydropyridine (MPTP). The model mice were treated with different concentrations of ApoAI MP. The open-field behavioral test assesses the total distance moved, the rest time, and the number of crossings and Rota-rod was used to evaluate motor coordination. Oxidative stress was identified by measuring the levels of superoxide dismutase (SOD), catalase (CAT), glutathionperoxidase (GSH-Px), malondialdehyde, ROS and H2O2. Inflammatory situation was analyzed by measuring the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Meanwhile, the scavenging activities of ApoAI MP for ABTS, DPPH, hydroxyl radical and superoxide anion, and the effects of the peptide on neurotransmitters were evaluated.

Results: PD model establishment increased oxidative stress and inflammatory status by increasing the concentrations of ROS and H2O2 production, and the levels of TNF-α, IL-1β and IL-6 (p < 0.05). ApoAI MP intervention improved PD symptoms by reducing the total moved distance and the number of passes (p < 0.01), and the falling times from Rota-rod, and increasing rest time (p < 0.05). ApoAI MP increased antioxidant properties by increasing the activities of SOD, CAT and GSH-Px, and reducing MDA concentration (p < 0.05). ApoAI MP addition reduced oxidative stress by scavenging ABTS, DPPH, hydroxyl radicals and superoxide anion and reducing the concentrations of ROS and H2O2 production (p < 0.05). ApoAI MP treatment increased anti-inflammatory capacities by reducing the concentrations of TNF-α, IL-1β and IL-6 (p < 0.05). HPLC analysis showed that the peptide treatment improved neurotransmitters.

Conclusion: ApoAI MP can improve the behavioral performance of PD mice by improving antioxidant and anti-inflammatory capacities.