Natural compound methyl protodioscin protects rat brain from ischemia/reperfusion injury through regulation of Mul1/SOD2 pathway

Invasive metastatic tumor-camouflaged ROS responsive nanosystem for targeting therapeutic brain injury after cardiac arrest

Drug transmission through the blood-brain barrier (BBB) is considered an arduous challenge for brain injury treatment following the return of spontaneous circulation after cardiac arrest (CA-ROSC). Inspired by the propensity of melanoma metastasis to the brain, B16F10 cell membranes are camouflaged on 2-methoxyestradiol (2ME2)-loaded reactive oxygen species (ROS)-triggered "Padlock" nanoparticles that are constructed by phenylboronic acid pinacol esters conjugated D-a-tocopheryl polyethylene glycol succinate (TPGS-PBAP). The biomimetic nanoparticles (BM@TP/2ME2) can be internalized, mainly mediated by the mutual recognition and interaction between CD44v6 expressed on B16F10 cell membranes and hyaluronic acid on cerebral vascular endothelial cells, and they responsively release 2ME2 by the oxidative stress microenvironment. Notably, BM@TP/2ME2 can scavenge excessive ROS to reestablish redox balance, reverse neuroinflammation, and restore autophagic flux in damaged neurons, eventually exerting a remarkable neuroprotective effect after CA-ROSC in vitro and in vivo. This biomimetic drug delivery system is a novel and promising strategy for the treatment of cerebral ischemia-reperfusion injury after CA-ROSC.

Targeting Energy Protection as a Novel Strategy to Disclose Di'ao Xinxuekang against the Cardiotoxicity Caused by Doxorubicin

Doxorubicin (DOX) can induce myocardial energy metabolism disorder and further worsen heart failure. "Energy protection" is proposed as a new cardiac protection strategy. Previous studies have found that Di'ao Xinxuekang (DXXK) can improve doxorubicin-induced cardiotoxicity in mice by inhibiting ferroptosis. However, there are very few studies associating DXXK and energy protection. This study aims to explore the "energy protection" effect of DXXK on cardiotoxicity induced by DOX. A DOX-induced cardiotoxicity model established in rats and H9c2 cells are used to analyze the therapeutic effects of DXXK on serum indexes, cardiac function indexes and cardiac histopathology. The metabonomic methods were used to explore the potential mechanism of DXXK in treating DOX-induced cardiotoxicity. In addition, we also observed the mitochondrial- and autophagy-related indicators of myocardial cells and the mRNA expression level of the core target regulating energy-metabolism-related pathways. Our results indicated that DXXK can improve cardiac function, reduce myocardial enzymes and alleviate the histological damage of heart tissue caused by DOX. In addition, DXXK can improve mitochondrial damage induced by DOX and inhibit excessive autophagy. Metabonomics analysis showed that DOX can significantly affects the pathways related to energy metabolism of myocardial cells, which are involved in the therapeutic mechanism of DXXK. In conclusion, DXXK can treat DOX-induced cardiotoxicity through the AMPK-mediated energy protection pathway.

Pharmacological therapy to cerebral ischemia-reperfusion injury: Focus on saponins

Secondary insult from cerebral ischemia-reperfusion injury (CIRI) is a major risk factor for poor prognosis of cerebral ischemia. Saponins are steroid or triterpenoid glycosides with various pharmacological activities that are effective in treating CIRI. By browsing the literature from 2001 to 2021, 55 references involving 24 kinds of saponins were included. Saponins were shown to relieve CIRI by inhibiting oxidation stress, neuroinflammation, and apoptosis, restoring BBB integrity, and promoting neurogenesis and angiogenesis. This review summarizes and classifies several common saponins and their mechanisms in relieving CIRI. Information provided in this review will benefit researchers to design, research and develop new medicines to treat CIRI-related conditions with saponins.

Mitochondrial E3 ubiquitin ligase 1 (MUL1) as a novel therapeutic target for diseases associated with mitochondrial dysfunction

Mitochondrial E3 ubiquitin ligase 1 (MUL1) is a mitochondrial outer membrane-anchored protein-containing transmembrane domain in its N- and C-terminal regions, where both are exposed to the cytosol. Interestingly the C-terminal region has a RING finger domain responsible for its E3 ligase activity, as ubiquitin or in SUMOylation, interacting with proteins related to mitochondrial fusion and fission, cell survival, and tumor suppressor process, such as Akt. Therefore, MUL1 is involved in various cellular processes, such as mitochondrial dynamics, inter-organelle communication, proliferation, mitophagy, immune response, inflammation and cell apoptosis. MUL1 is expressed at a higher basal level in the heart, immune system organs, and blood. Here, we discuss the role of MUL1 in mitochondrial dynamics and its function in various pathological models, both in vitro and in vivo. In this context, we describe the role of MUL1 in: (1) the inflammatory response, by regulating NF-κB activity; (2) cancer, by promoting cell death and regulating exonuclear function of proteins, such as p53; (3) neurological diseases, by maintaining communication with other organelles and interacting with proteins to eliminate damaged organelles and; (4) cardiovascular diseases, by maintaining mitochondrial fusion/fission homeostasis. In this review, we summarize the latest advances in the physiological and pathological functions of MUL1. We also describe the different substrates of MUL1, acting as a positive or negative regulator in various pathologies associated with mitochondrial dysfunction. In conclusion, MUL1 could be a potential key target for the development of therapies that focus on ensuring the functionality of the mitochondrial network and, furthermore, the quality control of intracellular components by synchronously modulating the activity of different cellular mechanisms involved in the aforementioned pathologies. This, in turn, will guide the development of targeted therapies.

Synthesis and Antitumor Activity of Diosgenin Hydroxamic Acid and Quaternary Phosphonium Salt Derivatives

Diosgenin, a component separated from Dioscorea plants, is an important starting material for steroid hormone drugs and semisynthetic steroids. In the work, two series of diosgenin derivatives were designed, synthesized, and evaluated for their cellular anticancer activities. Most of the target compounds exhibited good inhibitory activities against four cell lines, Aspc-1 (human colon adenocarcinoma cells), H358 (human nonsmall cell lung cancer cells), HCT116 (human colorectal adenocarcinoma cells), and SW620 (human metastatic pancreatic cancer cells). Among them, the representative compound 2.2f exhibited 7.9-341.7-fold antiproliferative activities against the above-mentioned four cell lines compared with the lead compound diosgenin.

Dipsacoside B Exerts a Beneficial Effect on Brain Injury in the Ischemic Stroke Rat through Inhibition of Mitochondrial E3 Ubiquitin Ligase 1

BACKGROUND

Upregulation of mitochondrial E3 ubiquitin ligase 1 (Mul1) contributes to brain injury in ischemic stroke due to disturbance of mitochondrial dynamics, and bioinformatics analysis predicts that Mul1 is a potential target of Dipsacoside B.

OBJECTIVE

The aim of the study was to explore whether Dipsacoside B can exert a beneficial effect on brain injury in the ischemic stroke rat via targeting Mul1.

METHODS

The SD rat brains or PC12 cells were subjected to 2 h-ischemia or 8 h-hypoxia plus 24 h-reperfusion or 24 h-reoxygenation to establish the ischemic stroke rat model in vivo or in vitro, which were treated with Dipsacoside B at different dosages. The brain or PC12 cell injury, relevant protein levels and mitochondrial functions were measured by methods of biochemistry, flow cytometry or Western blot.

RESULTS

The neurological dysfunction and brain injury (such as infarction and apoptosis) observed in the ischemic stroke rats were accompanied by increases in Mul1 and dynamin-related protein 1 (Drp1) levels along with decreases in mitofusin 2 (Mfn2) level and ATP production. These effects were attenuated by Dipsacoside B. Consistently, cell injury (necroptosis and apoptosis) occurred in the PC12 cells exposed to hypoxia concomitant with the upregulation of Mul1 and Drp1 along with downregulation of Mfn2 and mitochondrial functions (such as increases in reactive oxygen species production and mitochondrial fission and decreases in mitochondrial membrane potential and ATP production).These phenomena were reversed in the presence of Dipsacoside B.

CONCLUSION

Dipsacoside B can protect the rat brain against ischemic injury via inhibition of Mul1 due to the improvement of mitochondrial function.

Sinomenine in Cardio-Cerebrovascular Diseases: Potential Therapeutic Effects and Pharmacological Evidences

Cardio-cerebrovascular diseases, as a major cause of health loss all over the world, contribute to an important part of the global burden of disease. A large number of traditional Chinese medicines have been proved effective both clinically and in pharmacological investigations, with the acceleration of the modernization of Chinese medicine. Sinomenine is the main active constituent of sinomenium acutum and has been generally used in therapies of rheumatoid arthritis and neuralgia. Varieties of pharmacological effects of sinomenine in cardio-cerebrovascular system have been discovered recently, suggesting an inspiring application prospect of sinomenine in cardio-cerebrovascular diseases. Sinomenine may retard the progression of atherosclerosis by attenuating endothelial inflammation, regulating immune cells function, and inhibiting the proliferation of vascular smooth muscle cells. Sinomenine also alleviates chronic cardiac allograft rejection relying on its anti-inflammatory and anti-hyperplastic activities and suppresses autoimmune myocarditis by immunosuppression. Prevention of myocardial or cerebral ischemia-reperfusion injury by sinomenine is associated with its modulation of cardiomyocyte death, inflammation, calcium overload, and oxidative stress. The regulatory effects on vasodilation and electrophysiology make sinomenine a promising drug to treat hypertension and arrhythmia. Here, in this review, we will illustrate the pharmacological activities of sinomenine in cardio-cerebrovascular system and elaborate the underlying mechanisms, as well as give an overview of the potential therapeutic roles of sinomenine in cardio-cerebrovascular diseases, trying to provide clues and bases for its clinical usage.

Nose to brain drug delivery - A promising strategy for active components from herbal medicine for treating cerebral ischemia reperfusion

Cerebral ischemia reperfusion injury (CIRI), one of the major causes of death from stroke in the world, not only causes tremendous damage to human health, but also brings heavy economic burden to society. Current available treatments for CIRI, including mechanical therapies and drug therapies, are often accompanied by significant side-effects. Therefore, it is necessary to discovery new strategies for treating CIRI. Many studies have confirmed that the herbal medicine has the advantages of abundant resources, good curative effect and little side effects, which can be used as potential drug for treatment of CIRI through multiple targets. It's known that oral administration commonly has low bioavailability, and injection administration is inconvenient and unsafe. Many drugs can't delivery to brain through routine pathways due to the blood-brain-barrier (BBB). Interestingly, increasing evidences have suggested the nasal administration is a potential direct route to transport drug into brain avoiding the BBB and has the characteristics of high bioavailability for treating brain diseases. Therefore, intranasal administration can be treated as an alternative way to treat brain diseases. In the present review, effective methods to treat CIRI by using active ingredients derived from herbal medicine through nose to brain drug delivery (NBDD) are updated and discussed, and some related pharmacological mechanisms have also been emphasized. Our present study would be beneficial for the further drug development of natural agents from herbal medicines via NBDD.

Asiaticoside Alleviates Cerebral Ischemia-Reperfusion Injury via NOD2/Mitogen-Activated Protein Kinase (MAPK)/Nuclear Factor kappa B (NF-κB) Signaling Pathway

BACKGROUND Cerebral ischemia-reperfusion injury (CIRI) remains a serious health problem. Centella asiatica formulations are used to treat central nervous system disorders. In the present study, asiaticoside, an extract of the plant Centella asiatica, was investigated in CIRI in vivo and vitro. MATERIAL AND METHODS We made a CIRI model in vivo in SD rats treated by middle cerebral artery occlusion, and a cell model of ischemia-reperfusion injury was made in PC12 cells treated by deprivation of oxygen and glucose/restoration. CIRI in vivo was assessed by scores of neurological functions, encephaledema, and cerebral infarction area. Inflammation level and oxidative stress level were detected by the appropriate kits. TUNEL assay was performed for assessment of cell apoptosis and Western blot analysis was performed to assess protein expression levels. CCK8 assay was performed for evaluation of cell survival and flow cytometer was used to detect cell apoptosis in vitro. RESULTS Nervous function injury, brain edema, cell apoptosis, infarct size, apoptosis-related protein expressions, and protein expressions of the NOD2/MAPK/NF-kappaB signaling pathway in the CIRI model were all reversed by asiaticoside in rats. The cell apoptosis, inflammation level, and oxidative stress level in the model of cerebral ischemia-reperfusion injury were reduced by asiaticoside. The effects of asiaticoside on CIRI were reversed by NOD 2 agonists. CONCLUSIONS Asiaticoside showed a protective effect against cerebral ischemia-reperfusion injury via the NOD2/MAPK/NF-kappaB signaling pathway. These findings are vital for future research on use of asiaticoside in CIRI, providing a new avenue for alleviating CIRI.

NR4A2 Exacerbates Cerebral Ischemic Brain Injury via Modulating microRNA-652/Mul1 Pathway

BACKGROUND

Nuclear receptor subfamily group A member 2 (NR4A2), a transcription factor, was suggested to be involved in the pathogenesis of ischemic stroke. Nevertheless, the specific role of NR4A2 in ischemic brain injury has yet to be elucidated. Our aim was to probe the mechanisms behind the repression of microRNA (miRNA) expression resulting from NR4A2 regulation in ischemic brain injury.

METHODS

A rat model with transient global cerebral ischemia (tGCI) was established, followed by HE staining and immunohistochemistry for verification. Subsequently, NR4A2 expression in rat brain tissues was detected by RT-qPCR, Western blot and immunohistochemistry. Then, PC12 cells were treated with NR4A2 alteration and subjected to oxygen-glucose deprivation (OGD) for cerebral ischemia simulation. Cell viability, apoptosis and cycle distribution were detected by CCK-8 and flow cytometry, respectively. miR-652 expression in rat brain tissues and cells was then detected by RT-qPCR, and then the targeting mRNAs of miR-652 were predicted through bioinformatic websites. Finally, the effect of miR-652 and mitochondrial E3 ubiquitin ligase 1 (Mul1) on the PC12 cell activity after OGD treatment was verified by rescue experiments.

RESULTS

NR4A2 and Mul1 were expressed highly in brain tissues of rats with tGCI, while miR-652 was expressed poorly. NR4A2 inhibited the expression of miR-652 by transcription, thus blocking the inhibition of miR-652 on Mul1 to repress PC12 cell activity and promote apoptosis and G0/G1 cell cycle arrest.

CONCLUSION

The transcription factor NR4A2 mediates the expression of Mul1 through transcriptional repression of miR-652, thus promoting ischemic brain injury.