Sac-1004, a vascular leakage blocker, reduces cerebral ischemia-reperfusion injury by suppressing blood-brain barrier disruption and inflammation

Astrocyte modulation in cerebral ischemia-reperfusion injury: A promising therapeutic strategy

Cerebral ischemia-reperfusion injury (CIRI) poses significant challenges for drug development due to its complex pathogenesis. Astrocyte involvement in CIRI pathogenesis has led to the development of novel astrocyte-targeting drug strategies. To comprehensively review the current literature, we conducted a thorough analysis from January 2012 to December 2023, identifying 82 drugs aimed at preventing and treating CIRI. These drugs target astrocytes to exert potential benefits in CIRI, and their primary actions include modulation of relevant signaling pathways to inhibit neuroinflammation and oxidative stress, reduce cerebral edema, restore blood-brain barrier integrity, suppress excitotoxicity, and regulate autophagy. Notably, active components from traditional Chinese medicines (TCM) such as Salvia miltiorrhiza, Ginkgo, and Ginseng exhibit these important pharmacological properties and show promise in the treatment of CIRI. This review highlights the potential of astrocyte-targeted drugs to ameliorate CIRI and categorizes them based on their mechanisms of action, underscoring their therapeutic potential in targeting astrocytes.

JR14a: A novel antagonist of C3aR attenuates neuroinflammation in cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion injury (CIRI), a prevalent stroke-related complication, can lead to severe brain damage. Inflammation is a crucial factor in CIRI pathogenesis, and the complement component 3a receptor (C3aR) could be a key mediator in the post-CIRI inflammatory cascade. In this study, the role of C3aR in CIRI was investigated utilizing a middle cerebral artery occlusion (MCAO) model in C3aR knockout (KO) mice. Magnetic resonance imaging (MRI) and neurofunctional assessments revealed that C3aR KO mice exhibited significantly diminished cerebral infarction and improved neurological impairments. Consequently, the focus shifted to searching for a small molecule antagonist of C3aR. JR14a, a new potent thiophene antagonist of C3aR, was injected intraperitoneally into mice 1-h post-MCAO model implementation. The mass spectrometry (MS) results indicated the ability of JR14a to penetrate the blood-brain barrier. Subsequent TTC staining and neurofunctional assessments revealed the efficacy of JR14a in reducing cerebral infarct volume and neurological impairment following MCAO. In addition, immunofluorescence (IF) and immunohistochemistry (IHC) demonstrated attenuated microglial activation, neutrophil infiltration, and blood-brain barrier disruption by JR14a in the MCAO model. Furthermore, enzyme-linked immunosorbent assay (ELISA) and Western blotting supported the role of JR14a in downregulating the expression levels of C3aR, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6), as well as the phosphorylation of p65. In conclusion, the findings suggested that C3aR could be a potential therapeutic target for CIRI, and JR14a emerged as a promising treatment candidate.

Pathophysiological changes of muscle after ischemic stroke: a secondary consequence of stroke injury

Sufficient clinical evidence suggests that the damage caused by ischemic stroke to the body occurs not only in the acute phase but also during the recovery period, and that the latter has a greater impact on the long-term prognosis of the patient. However, current stroke studies have typically focused only on lesions in the central nervous system, ignoring secondary damage caused by this disease. Such a phenomenon arises from the slow progress of pathophysiological studies examining the central nervous system. Further, the appropriate therapeutic time window and benefits of thrombolytic therapy are still controversial, leading scholars to explore more pragmatic intervention strategies. As treatment measures targeting limb symptoms can greatly improve a patient's quality of life, they have become a critical intervention strategy. As the most vital component of the limbs, skeletal muscles have become potential points of concern. Despite this, to the best of our knowledge, there are no comprehensive reviews of pathophysiological changes and potential treatments for post-stroke skeletal muscle. The current review seeks to fill a gap in the current understanding of the pathological processes and mechanisms of muscle wasting atrophy, inflammation, neuroregeneration, mitochondrial changes, and nutritional dysregulation in stroke survivors. In addition, the challenges, as well as the optional solutions for individualized rehabilitation programs for stroke patients based on motor function are discussed.

Adipokine vaspin maintains angiogenesis and neurological function during cerebral ischemia-reperfusion via suppressing endoplasmic reticulum stress

INTRODUCTION

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an adipokine. It has been reported that decreased serum vaspin levels are significantly associated with stroke severity and prognosis.

PURPOSE

This article aims to explore the theoretical feasibility of vaspin supplementation for cerebral ischemia-reperfusion (I/R) injury.

METHODS

The I/R mouse models were constructed by the middle cerebral artery occlusion (MCAO) method, and the effects of vaspin on cerebral infarction, neurological function, angiogenesis and endoplasmic reticulum (ER) stress were explored. To verify the mediation of ER stress in the regulation of vaspin, human brain microvascular endothelial cells (HBMECs) were subjected to ER stress agonist tunicamycin in vitro. The impacts of vaspin and tunicamycin on oxygen glucose deprivation/ recovery (OGD/R)-induced cell viability, apoptosis, and angiogenesis were examined.

RESULTS

Vaspin inhibited blood-brain barrier breakdown and infarction occurred in the brain tissue of the I/R mice. Vaspin also enhanced cerebral neovascularization and reduced the apoptosis. Additional tunicamycin increased the apoptosis of HBMECs and inhibited angiogenesis, reversing the protective effect of vaspin on cells.

CONCLUSION

Together, this study reveals that vaspin supplementation reduces cerebral infarction and works against neurological dysfunction. It maintains the survival and angiogenesis capacity of HBMECs by inhibiting ER stress.

A novel small molecule, CU05-1189, targeting the pleckstrin homology domain of PDK1 suppresses VEGF-mediated angiogenesis and tumor growth by blocking the Akt signaling pathway

Inhibition of angiogenesis is considered a promising therapeutic approach for cancer treatment. Our previous genetic research showed that the use of a cell-penetrating peptide to inhibit the pleckstrin homology (PH) domain of 3-phosphoinositide-dependent kinase 1 (PDK1) was a viable approach to suppress pathological angiogenesis. Herein, we synthesized and characterized a novel small molecule, CU05-1189, based on our prior study and present evidence for the first time that this compound possesses antiangiogenic properties both in vitro and in vivo. The computational analysis showed that CU05-1189 can interact with the PH domain of PDK1, and it significantly inhibited vascular endothelial growth factor (VEGF)-induced proliferation, migration, invasion, and tube formation in human umbilical vein endothelial cells without apparent toxicity. Western blot analysis revealed that the Akt signaling pathway was specifically inhibited by CU05-1189 upon VEGF stimulation, without affecting other VEGF receptor 2 downstream molecules or cytosolic substrates of PDK1, by preventing translocation of PDK1 to the plasma membrane. We also found that CU05-1189 suppressed VEGF-mediated vascular network formation in a Matrigel plug assay. More importantly, CU05-1189 had a good pharmacokinetic profile with a bioavailability of 68%. These results led to the oral administration of CU05-1189, which resulted in reduced tumor microvessel density and growth in a xenograft mouse model. Taken together, our data suggest that CU05-1189 may have great potential and be a promising lead as a novel antiangiogenic agent for cancer treatment.

Scientific Landscape of Oxidative Stress in Stroke: From a Bibliometric Analysis to an in-Depth Review

Stroke is an acute cerebrovascular disease resulting from either obstruction or rupture of a blood vessel in the brain. Oxidative stress (OS), referred to a status where cellular oxidative capacities overwhelm antioxidative defenses, is involved in the pathophysiology of stroke. The bibliometric analysis and in-depth review aim to depict the research trend of OS in stroke. Relevant scientific publications were acquired from the Web of Science Core Collection database. Scientific landscape of OS in stroke was illustrated by general quantitative trend, impactful journals, and co-authorship of various academic units (i.e., countries/regions, organizations, and authors). Furthermore, theme analysis predicting the hot research issues and frontiers was performed. 15,826 documents regarding OS in stroke were obtained over a time span of more than 20 years from 1992 to 2021. The overall tendency of publication counts was continuously on the rise. Bibliometric analysis indicated China and the United States were predominant in this study field, as reflected by their high publication counts and intensive collaboration with other countries. Current key research areas of OS in stroke may lie in the investigation of neuroinflammation, and interaction among multiple cell death mechanisms including apoptosis, autophagy, and ferroptosis to search for effective treatments. Moreover, another hot topic could be the association between air pollution and stroke, and its underlying mechanisms. As the exploration of OS in stroke is speculated to be a continuous hot spot in the future, this article may be helpful for researchers to conduct future studies with the understanding of influential academic forces and research highlights.

The role and mechanisms of microvascular damage in the ischemic myocardium

Following myocardial ischemic injury, the most effective clinical intervention is timely restoration of blood perfusion to ischemic but viable myocardium to reduce irreversible myocardial necrosis, limit infarct size, and prevent cardiac insufficiency. However, reperfusion itself may exacerbate cell death and myocardial injury, a process commonly referred to as ischemia/reperfusion (I/R) injury, which primarily involves cardiomyocytes and cardiac microvascular endothelial cells (CMECs) and is characterized by myocardial stunning, microvascular damage (MVD), reperfusion arrhythmia, and lethal reperfusion injury. MVD caused by I/R has been a neglected problem compared to myocardial injury. Clinically, the incidence of microvascular angina and/or no-reflow due to ineffective coronary perfusion accounts for 5-50% in patients after acute revascularization. MVD limiting drug diffusion into injured myocardium, is strongly associated with the development of heart failure. CMECs account for > 60% of the cardiac cellular components, and their role in myocardial I/R injury cannot be ignored. There are many studies on microvascular obstruction, but few studies on microvascular leakage, which may be mainly due to the lack of corresponding detection methods. In this review, we summarize the clinical manifestations, related mechanisms of MVD during myocardial I/R, laboratory and clinical examination means, as well as the research progress on potential therapies for MVD in recent years. Better understanding the characteristics and risk factors of MVD in patients after hemodynamic reconstruction is of great significance for managing MVD, preventing heart failure and improving patient prognosis.

[Naoluo Xintong Decoction activates caspase-1/Gasdermin D pathway to promote angiogenesis of rat brain microvascular endothelial cells after oxygen glucose deprivation/reperfusion injury]

OBJECTIVE

To investigate the effects of Naoluo Xintong Decoction (NLXTD) on pyroptosis and angiogenesis of brain microvascular endothelial cells (BMECs) and explore the possible mechanisms in rats with oxygen-glucose deprivation/ reperfusion (OGD/R).

METHODS

Rat BMECs with or without caspase-1 siRNA transfection were cultured in the presence of 10% medicated serum from NLXTD-treated rats (or blank serum) and exposed to OGD/R. CCK-8 assay, Transwell chamber assay, and tube formation assay were used to assess proliferation, migration, and tube-forming abilities of the cells. The activity of lactate dehydrogenase (LDH) in the culture supernatant was determined using a commercial assay kit, and the levels of inflammatory factors IL-1β and IL-18 were detected with ELISA. The cellular expressions of pro-caspase-1, caspase-1, NLRP3, Gasdermin D, and angiogenesis-related proteins VEGF and VEGFR2 were detected using Western blotting.

RESULTS

The BMECs showed obvious injuries after OGD/R exposure. Compared with the blank serum, the medicated serum significantly improved the cell viability, migration ability, and lumen-forming ability (P < 0.01) and lowered the levels of IL-1β and IL-18 and the LDH release (P < 0.01) of the cells with OGD/R exposure. Western blotting showed that in the BMECs exposed to OGD/R, the medicated serum strongly upregulated the expression of VEGF and VEGFR2 proteins (P < 0.01) and reduced the protein expressions of pro-caspase-1, caspase-1, NLRP3, and Gasdermin D (P < 0.01), and transfection of the cells with caspase-1 siRNA further promoted the expressions of VEGFR2 protein in the cells (P < 0.01).

CONCLUSION

NLXTD can improve the proliferation, migration, and tube- forming ability and promote angiogenesis of BMECs with OGD/R injury probably by inhibiting the caspase-1/Gasdermin D pathway in pyroptosis, alleviating cell injury, and upregulating the expressions of VEGF and VEGFR2.

Microvascular Leakage as Therapeutic Target for Ischemia and Reperfusion Injury

Reperfusion injury is a very common complication of various indicated therapies such as the re-opening of vessels in the myocardium or brain as well as reflow in hemodynamic shutdown (cardiac arrest, severe trauma, aortic cross-clamping). The treatment and prevention of reperfusion injury has therefore been a topic of immense interest in terms of mechanistic understanding, the exploration of interventions in animal models and in the clinical setting in major prospective studies. While a wealth of encouraging results has been obtained in the lab, the translation into clinical success has met with mixed outcomes at best. Considering the still very high medical need, progress continues to be urgently needed. Multi-target approaches rationally linking interference with pathophysiological pathways as well as a renewed focus on aspects of microvascular dysfunction, especially on the role of microvascular leakage, are likely to provide new insights.

Efficacy of CU06-1004 via regulation of inflammation and endothelial permeability in LPS-induced acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening condition that fundamentally results from inflammation and edema in the lung. There are no effective treatments available for clinical use. Previously, we found that as a leakage blocker CU06-1004 prevents endothelial barrier disruption and enhances endothelial cell survival under inflammatory conditions. In this study, we aimed to elucidate the effect of CU06-1004 in terms of prevention of inflammation and endothelial dysfunction in an ALI mouse model.

METHODS

An ALI model was established that included intraperitoneal administration of LPS. Following LPS administration, survival rates and lung wet/dry ratios were assessed. Histological analysis was performed using hematoxylin and eosin staining. Scanning electron microscopy was used to examine alveolar and capillary morphology. Cytokines such as IL-1β, IL-6, and TNF-α were analyzed using an ELISA assay of bronchoalveolar lavage fluid (BALF) and serum. Neutrophil infiltration was observed in BALF using Wright-Giemsa staining, and myeloperoxidase (MPO) activity was assessed. Pulmonary vascular leakage was confirmed using Evans-blue dye, and the expression of junctional proteins was evaluated using immunofluorescent staining. Expression of adhesion molecules was observed using immunofluorescence staining. NF-κB activation was determined using immunohistochemistry and western blot analysis.

RESULTS

Survival rates and pulmonary edema were ameliorated with CU06-1004 treatment. Administration of CU06-1004 normalized histopathological changes induced by LPS, and alveolar-capillary wall thickening was reduced. Compared with the LPS-challenged group, after CU06-1004 treatment, the infiltration of immune cells was decreased in the BALF, and MPO activity in lung tissue was reduced. Similarly, in the CU06-1004 treatment group, pro-inflammatory cytokines were significantly inhibited in both BALF and serum. Evans-blue leakage was reduced, and the expression of junctional proteins was recovered in the CU06-1004 group. Adhesion molecules were downregulated and NF-κB activation was inhibited after CU06-1004 treatment.

CONCLUSIONS

These results suggested that CU06-1004 had a therapeutic effect against LPS-induced ALI via alleviation of the inflammatory response and protection of vascular integrity.

CU06-1004 alleviates vascular hyperpermeability in a murine model of hereditary angioedema by protecting the endothelium

BACKGROUND

Over-release of the vasoactive peptide bradykinin (BK) due to mutation in the SERPING1 gene is the leading cause of hereditary angioedema (HAE). BK directly activates endothelial cells and increases vascular permeability by disrupting the endothelial barrier, leading to angioedema affecting face, lips, extremities, gastrointestinal tract, and larynx. Although various pharmacological treatment options for HAE became available during the last decade, they are presently limited and pose a major economic burden on patients. To identify additional therapeutic options for HAE, we evaluated the effect of CU06-1004, an endothelial dysfunction blocker, on BK-induced vascular hyperpermeability and the HAE murine model.

METHODS

To investigate the effect of CU06-1004 on BK-induced vascular hyperpermeability in vivo, we pre-administrated WT mice with the drug and then induced vascular leakage through intravenous injection of BK and observed vascular alternation. Then, SERPING1 deficient mice were used for a HAE murine model. For an in vitro model, the HUVEC monolayer was pre-treated with CU06-1004 and then stimulated with BK.

RESULTS

Bradykinin disrupted the endothelial barrier and formed interendothelial cell gaps, leading to hyperpermeability in vivo and in vitro. However, CU06-1004 treatment protected the endothelial barrier by suppressing Src and myosin light chain activation via BK and alleviated hyperpermeability.

CONCLUSION

Our study shows that CU06-1004 oral administration significantly reduced vascular hyperpermeability in the HAE murine model by protecting the endothelial barrier function against BK stimulation. Therefore, protecting endothelium against BK with CU06-1004 could serve as a potential prophylactic/therapeutic approach for HAE patients.

Long-term administration of CU06-1004 ameliorates cerebrovascular aging and BBB injury in aging mouse model

BACKGROUND

Age-related changes in the cerebrovasculature, including blood-brain barrier (BBB) disruption and vascular dementia, are emerging as potential risks for many neurodegenerative diseases. Therefore, the endothelial cells that constitute the cerebrovasculature may play key roles in preventing brain injury. Our previous study showed that CU06-1004, an endothelial cell dysfunction blocker, prevented vascular leakage, enhanced vascular integrity in ischemic reperfusion injury, and promoted the normalization of tumor vasculature. Here, we evaluated the effects of CU06-1004 on age-related cerebrovascular functional decline in the aged mouse brain.

RESULTS

In this study, we investigated the protective effects of CU06-1004 against oxidative stress-induced damage in human brain microvascular endothelial cells (HBMECs). HBMECs were treated with hydrogen peroxide (H₂O₂) to establish an oxidative stress-induced model of cellular injury. Compared with H₂O₂ treatment alone, pretreatment of HBMECs with CU06-1004 considerably reduced oxidative stress-induced cytotoxicity, reactive oxygen species generation, senescence-associated β-galactosidase activity, senescence marker expression, and the expression levels of inflammatory proteins. Based on the observed cytoprotective effects of CU06-1004 in HBMECs, we examined whether CU06-1004 displayed protective effects against cerebrovascular aging in mice. Long-term administration of CU06-1004 alleviated age-associated cerebral microvascular rarefaction and cerebrovascular senescence in the aged mouse brain. CU06-1004 supplementation also reduced the extravasation of plasma IgG by improving BBB integrity in the aged mouse brain, associated with reductions in neuronal injury. A series of behavioral tests also revealed improved motor and cognitive functions in aged mice that received long-term CU06-1004 administration.

CONCLUSIONS

These findings suggest that CU06-1004 may represent a promising therapeutic approach for delaying age-related cerebrovascular impairment and improving cognitive function in old age.

Oral administration of CU06-1004 attenuates vascular permeability and stabilizes neovascularization in retinal vascular diseases

Retinal vascular diseases are the leading cause of blindness worldwide. These diseases have common disease mechanisms including vascular endothelial growth factor (VEGF) signaling, hypoxia, and inflammation. Treatment of these diseases with laser therapy, anti-VEGF injections and/or steroids has significantly improved clinical outcomes. However, these strategies do not address the underlying cause of the pathology and may have harmful side effects. Pathological processes that damage retinal vessels result in vascular occlusion and impairment of the barrier properties of retinal endothelial cells, leading to excessive vascular leakage. Therefore, a new therapeutic approach is needed for the treatment of retinal vascular disease. We were able to confirm that oral administration of CU06-1004, an endothelial dysfunction blocker, inhibited retinal vascular leakage induced by vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang2). Interestingly, oral administration of CU06-1004 prevented excessive vascular leakage in the diabetic retinopathy model. In addition, CU06-1004 inhibited angiogenesis and confirmed vascular stabilization in the oxygen-induced retinopathy model and laser-induced CNV model. Taken together, CU06-1004 could be a potential therapeutic agent for the treatment of retinal vascular diseases.

Zhongfeng Capsules protects against cerebral ischemia-reperfusion injury via mediating the phosphoinositide 3-kinase/Akt and toll-like receptor 4/nuclear factor kappa B signaling pathways by regulating neuronal apoptosis and inflammation

Inflammatory reaction and neuronal apoptosis are the major pathophysiological mechanisms involved in cerebral ischemia-reperfusion injury (CI/RI). It has been reported that Zhongfeng Capsules (ZFCs), which contain Panax notoginseng, Hirudo, Red ginseng, Eupolyphaga sinensis, Pangolin scales, Rhubarb, and Radix Salvia miltiorrhizae, have a definite therapeutic effect on CI/RI. However, the specific molecular mechanisms of ZFCs are unclear. In this study, the effects of ZFCs on middle cerebral artery occlusion were investigated in rats. Our results showed that neurological impairment and neuronal apoptosis were alleviated in ZFC-treated rats. Additionally, infarct volume and cerebral edema decreased and there was an improvement in histopathological features. Furthermore, the expression levels of IL-1β, IL-6, and TNF-α were downregulated in ZFC-treated rats. TLR 4, NF-κB, Bax, and Caspase-3 expression also tended to decrease, whereas the expression of Bcl-2, p-PI3K, p-Akt, and I-κBα increased. The results indicate that the ZFCs effectively protected the rats against CI/RI possibly via the TLR4/NF-κB signaling pathway. Additionally, the formulation regulated the transcriptional activity of NF-κB, secretion of downstream inflammatory factors, and the expression of Bcl-2-Bax proteins in the PI3K/Akt pathway. Our findings suggest that ZFCs suppress neuronal apoptosis and inflammatory reaction via the PI3K/Akt and TLR4/NF-κB signaling pathways, respectively. Moreover, activation of the PI3K/Akt pathway may result in the inhibition of proinflammatory cytokine secretion, which may be another mechanism by which ZFCs alleviate CI/RI.

The Molecular Mechanisms of Ferroptosis and Its Role in Blood-Brain Barrier Dysfunction

The blood-brain barrier (BBB) is a selective, semi-permeable layer of endothelial cells that protects the central nervous system from harmful substances circulating in blood. It is one of the important barriers of the nervous system. BBB dysfunction is an early pathophysiological change observed in nervous system diseases. There are few treatments for BBB dysfunction, so this motivates the review. Ferroptosis is a novel cell death mode caused by iron-mediated lipid peroxidation accumulation, which has recently attracted more attention due to its possible role in nervous system disorders. Studies have shown that lipid peroxidation and iron accumulation are related to the barrier dysfunction, especially the expression of tight junction proteins. Therefore, examination of the relationship between ferroptosis and BBB dysfunction may reveal new targets for the treatment of brain diseases.

Relationship between Neuronal Damage/Death and Astrogliosis in the Cerebral Motor Cortex of Gerbil Models of Mild and Severe Ischemia and Reperfusion Injury

Neuronal loss (death) occurs selectively in vulnerable brain regions after ischemic insults. Astrogliosis is accompanied by neuronal death. It can change the molecular expression and morphology of astrocytes following ischemic insults. However, little is known about cerebral ischemia and reperfusion injury that can variously lead to damage of astrocytes according to the degree of ischemic injury, which is related to neuronal damage/death. Thus, the purpose of this study was to examine the relationship between damage to cortical neurons and astrocytes using gerbil models of mild and severe transient forebrain ischemia induced by blocking the blood supply to the forebrain for five or 15 min. Significant ischemia tFI-induced neuronal death occurred in the deep layers (layers V and VI) of the motor cortex: neuronal death occurred earlier and more severely in gerbils with severe ischemia than in gerbils with mild ischemia. Distinct astrogliosis was detected in layers V and VI. It gradually increased with time after both ischemiae. The astrogliosis was significantly higher in severe ischemia than in mild ischemia. The ischemia-induced increase of glial fibrillary acidic protein (GFAP; a maker of astrocyte) expression in severe ischemia was significantly higher than that in mild ischemia. However, GFAP-immunoreactive astrocytes were apparently damaged two days after both ischemiae. At five days after ischemiae, astrocyte endfeet around capillary endothelial cells were severely ruptured. They were more severely ruptured by severe ischemia than by mild ischemia. However, the number of astrocytes stained with S100 was significantly higher in severe ischemia than in mild ischemia. These results indicate that the degree of astrogliosis, including the disruption (loss) of astrocyte endfeet following ischemia and reperfusion in the forebrain, might depend on the severity of ischemia and that the degree of ischemia-induced neuronal damage may be associated with the degree of astrogliosis.

Anti-apoptosis effects of codonolactone on cerebral ischemia-reperfusion injury

Codonolactone is the main biologically active ingredient in Atractylodes lancea. Studies have shown various functions of codonolactone, while its protective effect against neurotoxicity caused by ischemic stroke is unclear. This study investigated the roles of codonolactone in inflammation, oxidative stress and apoptosis after cerebral ischemia-reperfusion (I/R) injury. Rats with codonolactone treatment, I/R treatment and the sham operation group were used in this study. After reperfusion for 24 hours, nerve damage was detected by nerve staining, and the neurological deficits of the rats were analyzed. The contents of superoxide dismutase (SOD), malondialdehyde (MDA), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in rat brain tissues were also determined. Western blot analysis was performed to determine the expression levels of Akt/Nrf2 pathway-associated proteins. Compared with the I/R group, the cerebral blood flow, infarct volume, brain water content, coronary blood flow and neurological deficits in the codonolactone treatment group, especially with the 80 mg/kg dosage, were significantly reduced. Codonolactone could significantly reduce the expression levels of caspase-3 and Bax, and significantly increase the expression levels of Bcl-2 after I/R. In addition, codonolactone could significantly reduce MDA content and the expression levels of TNF-α and IL-1β in ischemic brain tissues. It also significantly increased SOD activity, the expression levels of heme oxygenase-1 (HO-1) and the phosphorylation of Akt and Nrf2. Codonolactone ameliorated the cerebral I/R injury by improving anti-oxidant, anti-inflammatory activities and reducing apoptosis. Besides, the Akt/Nrf2 pathway was involved in the pharmacological action of the codonolactone.

CU06-1004 modulates the adenosine monophosphate (AMP)-associated protein kinase (AMPK) signaling pathway and inhibits lipogenesis in 3T3-L1 adipocytes and high-fat diet-induced obese mice

AIMS

The endothelial dysfunction blocker CU06-1004 exhibits anti-inflammatory effects in chronic diseases. Obesity is a major cause of chronic inflammation, and the effect of CU06-1004 on obesity has not been studied yet. Therefore, in this study, we investigated the anti-obesity properties of CU06-1004 in 3T3-L1 adipocytes and high-fat diet-induced obese mice.

METHODS

Differentiated 3T3-L1 adipocytes were treated with various concentrations of CU06-1004 (0-20 μg/mL) and subjected to Oil Red O staining to determine the levels of lipid droplet and intracellular triglyceride accumulation. Additionally, high-fat diet-induced obese C57BL/6J mice were administered with a low (10 mg/kg/day) or high (20 mg/kg/day) oral dose of CU06-1004. Finally, the expressions of genes and proteins involved in the adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway were assessed by real-time polymerase chain reaction and Western blot, respectively.

KEY FINDINGS

The CU06-1004 administration reduced lipid accumulation in the 3T3-L1 adipocytes by inhibiting the expressions of peroxisome proliferator-activated receptor gamma, CCAAT/enhancer-binding protein alpha, fatty acid binding protein 4, and fatty acid synthase in a dose-dependent manner. Additionally, it significantly increased the phosphorylation of AMPKα and acetyl-CoA carboxylase in the 3T3-L1 adipocytes. An oral administration of high dose of CU06-1004 in the obese mice significantly decreased their body weight and the mesenteric white adipose tissue weight. Furthermore, CU06-1004 improved hepatic steatosis by reducing lipogenesis, besides improving insulin resistance and exerting systemic anti-inflammatory effects.

SIGNIFICANCE

Therefore, CU06-1004 may have therapeutic potential in the prevention of obesity and obesity-related disorders.

CU06-1004 enhances vascular integrity and improves cardiac remodeling by suppressing edema and inflammation in myocardial ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury accelerates the cardiomyocytes (CMs) death by oxidative stress, and thereby deteriorates cardiac function. There has been a paradigm shift in the therapeutic perspective more towards the prevention or amelioration of damage caused by reperfusion. Cardiac microvascular endothelial cells (CMECs) are more vulnerable to reperfusion injury and play the crucial roles more than CMs in the pathological process of early I/R injury. In this study, we investigate that CU06-1004, as a vascular leakage blocker, can improve cardiac function by inhibiting CMEC's hyperpermeability and subsequently reducing the neutrophil's plugging and infiltration in infarcted hearts. CU06-1004 was delivered intravenously 5 min before reperfusion and the rats were randomly divided into three groups: (1) vehicle, (2) low-CU06-1004 (1 mg/kg, twice at 24 h intervals), and (3) high-CU06-1004 (5 mg/kg, once before reperfusion). CU06-1004 treatment reduced necrotic size and cardiac edema by enhancing vascular integrity, as demonstrated by the presence of intact junction proteins on CMECs and surrounding pericytes in early I/R injury. It also decreased the expression of vascular cell adhesion molecule 1 (VCAM-1) on CMECs, resulting in reduced infiltration of neutrophils and macrophages. Echocardiography showed that the CU06-1004 treatment significantly improved cardiac function compared with the vehicle group. Interestingly, single high-dose treatment with CU06-1004 provided a greater functional improvement than repetitive low-dose treatment until 8 weeks post I/R. These findings demonstrate that CU06-1004 enhances vascular integrity and improves cardiac function by preventing lethal myocardial I/R injury. It can provide a promising therapeutic option, as potential adjunctive therapy to current reperfusion strategies.

Therapeutic effects of stiripentol against ischemia-reperfusion injury in gerbils focusing on cognitive deficit, neuronal death, astrocyte damage and blood brain barrier leakage in the hippocampus

Stiripentol is an anti-epileptic drug for the treating of refractory status epilepticus. It has been reported that stiripentol can attenuate seizure severity and reduce seizure-induced neuronal damage in animal models of epilepsy. The objective of the present study was to investigate effects of post-treatment with stiripentol on cognitive deficit and neuronal damage in the cornu ammonis 1 (CA1) region of the hippocampus proper following transient ischemia in the forebrain of gerbils. To evaluate ischemia-induced cognitive impairments, passive avoidance test and 8-arm radial maze test were performed. It was found that post-treatment with stiripentol at 20 mg/kg, but not 10 or 15 mg/kg, reduced ischemia-induced memory impairment. Transient ischemia-induced neuronal death in the CA1 region was also significantly attenuated only by 20 mg/kg stiripentol treatment after transient ischemia. In addition, 20 mg/kg stiripentol treatment significantly decreased ischemia-induced astrocyte damage and immunoglobulin G leakage. In brief, stiripentol treatment after transient ischemia ameliorated transient ischemia-induced cognitive impairment in gerbils, showing that pyramidal neurons were protected and astrocyte damage and blood brain barrier leakage were significantly attenuated in the hippocampus. Results of this study suggest stiripentol can be developed as a candidate of therapeutic drug for ischemic stroke.

Changes in Cyclin D1, cdk4, and Their Associated Molecules in Ischemic Pyramidal Neurons in Gerbil Hippocampus after Transient Ischemia and Neuroprotective Effects of Ischemic Preconditioning by Keeping the Molecules in the Ischemic Neurons

Simple Summary

Cyclin D1 and cyclin-dependent kinase 4 (cdk4) is implicated in neuronal death induced by various pathological conditions. Ischemic preconditioning (IPC) confers neuroprotective effect, but underlying mechanisms have been poorly addressed. In this study, IPC protected pyramidal neurons (cells) in gerbil hippocampus after transient ischemia. Additionally, IPC controlled expressions of cyclin D1, cdk4, phosphorylated retinoblastoma (p-Rb), and E2 promoter binding factor 1 (E2F1). In particular, the expression of p16INK4a was not different by IPC. These findings indicate that cyclin D1/cdk4-related signals may play important roles in events in neurons related to damage/death following ischemic insults. Especially, the preservation of p16INK4a by IPC may be crucial in attenuating neuronal death/damage or protecting neurons after brain ischemic insults.

Abstract

Inadequate activation of cell cycle proteins including cyclin D1 and cdk4 is involved in neuronal cell death induced by diverse pathological stresses, including transient global brain ischemia. The neuroprotective effect of ischemic preconditioning is well-established, but the underlying mechanism is still unknown. In this study, we examined changes in cyclin D1, cdk4, and related molecules in cells or neurons located in Cornu Ammonis 1 (CA1) of gerbil hippocampus after transient ischemia for 5 min (ischemia and reperfusion) and investigated the effects of IPC on these molecules after ischemia. Four groups were used in this study as follows: sham group, ischemia group, IPC plus (+) sham group, and IPC+ischemia group. IPC was developed by inducing 2-min ischemia at 24 h before 5-min ischemia (real ischemia). Most pyramidal cells located in CA1 of the ischemia group died five days after ischemia. CA1 pyramidal cells in the IPC+ischemia group were protected. In the ischemia group, the expressions of cyclin D1, cdk4, phosphorylated retinoblastoma (p-Rb), and E2F1 (a transcription factor regulated by p-Rb) were significantly altered in the pyramidal cells with time after ischemia; in the IPC+ischemia group, they were controlled at the level shown in the sham group. In particular, the expression of p16^INK4a (an endogenous cdk inhibitor) in the ischemia group was reversely altered in the pyramidal cells; in the IPC+TI group, the expression of p16^INK4a was not different from that shown in the sham group. Our current results indicate that cyclin D1/cdk4-related signals may have important roles in events in neurons related to damage/death following ischemia and reperfusion. In particular, the preservation of p16^INK4a by IPC may be crucial in attenuating neuronal death/damage or protecting neurons after brain ischemic insults.

Neuroprotective effects of four different fluids on cerebral ischaemia/reperfusion injury in rats through stabilization of the blood-brain barrier

Protecting the blood–brain barrier (BBB) is a potential strategy to treat cerebral ischaemic injury. We previously reported that hypertonic sodium chloride hydroxyethyl starch 40 (HSH) treatment alleviates brain injury induced by transient middle cerebral artery occlusion (tMCAO). However, other fluids, including 20% mannitol (MN), 3% hypertonic sodium chloride (HTS) and hydroxyethyl starch 130/0.4 solution (HES), have the same effect as HSH in cerebral ischaemia/reperfusion injury (CI/RI) remains unclear. The present study evaluated the protective effects of these four fluids on the BBB in tMCAO rats. Sprague–Dawley (SD) rats were randomly assigned to six groups. A CI/RI rat model was established by tMCAO for 120 min followed by 24 h of reperfusion. The sham and tMCAO groups were treated with normal saline (NS), whereas the other four groups were treated with the four fluids. After 24 h of reperfusion, neurological function, brain oedema, brain infarction volume, permeability of the BBB, cortical neuron loss and protein and mRNA expression were assessed. The four fluids (especially HSH) alleviated neurological deficits and decreased the infarction volume, brain oedema, BBB permeability and cortical neuron loss induced by tMCAO. The expression levels of GFAP, IL‐1β, TNF‐α, MMP‐9, MMP‐3, AQP4, MMP‐9, PDGFR‐β and RGS5 were decreased, whereas the expression levels of laminin and claudin‐5 were increased. These data suggested that small‐volume reperfusion using HSH, HES, MN and HTS ameliorated CI/RI, probably by attenuating BBB disruption and postischaemic inflammation, with HSH exerting the strongest neuroprotective effect.

The Protective Effect of Liquiritin in Hypoxia/Reoxygenation-Induced Disruption on Blood Brain Barrier

Background: Stroke is the second leading cause of death in human life health, but current treatment strategies are limited to thrombolytic therapy, and because of the tight time window, many contraindications, and only a very small number of people can benefit from it, new therapeutic strategies are needed to solve this problem. As a physical barrier between the central nervous system and blood, the blood-brain barrier (BBB) maintains the homeostasis of the central nervous system. Maintaining the integrity of the BBB may emerge as a new therapeutic strategy. Liquiritin (LQ) is a flavonoid isolated from the medicinal plant Glycyrrhiza uralensis Fisch. ex DC. (Fabaceae), and this study aims to investigate the protective effects of LQ on brain microvascular endothelial cells (BMECs), to provide a new therapeutic strategy for stroke treatment, and also to provide research ideas for the development of traditional Chinese medicine (TCM).

Methods: The protective effects of LQ on HBMECs under the treatment of hypoxia reoxygenation (H/R) were investigated from different aspects by establishing a model of H/R injury to mimic ischemia-reperfusion in vivo while administrating different concentrations of LQ, which includes: cell proliferation, migration, angiogenesis, mitochondrial membrane potential as well as apoptosis. Meanwhile, the mechanism of LQ to protect the integrity of BBB by antioxidation and inhibiting endoplasmic reticulum (ER) stress was also investigated. Finally, to search for possible targets of LQ, a proteomic analysis approach was employed.

Results: LQ can promote cell proliferation, migration as well as angiogenesis and reduce mitochondrial membrane potential damage and apoptosis. Meanwhile, LQ can also reduce the expression of related adhesion molecules, and decrease the production of reactive oxygen species. In terms of mechanism study, we demonstrated that LQ could activate Keap1/Nrf2 antioxidant pathway, inhibit ER stress, and maintain the integrity of BBB. Through differential protein analysis, 5 disease associated proteins were found.

Conclusions: Studies have shown that LQ can promote cell proliferation, migration as well as angiogenesis, and reduce cell apoptosis, which may be related to its inhibition of oxidative and ER stress, and then maintain the integrity of BBB. Given that five differential proteins were found by protein analysis, future studies will revolve around the five differential proteins.

miR-671-5p Attenuates Neuroinflammation via Suppressing NF-κB Expression in an Acute Ischemic Stroke Model

This study was designed to investigate the role of miR-671-5p in in vitro and in vivo models of ischemic stroke (IS). Middle cerebral artery occlusion and reperfusion (MCAO/R) in C57BL/6 mice as well as oxygen-glucose deprivation and reoxygenation (OGD/R) in a mouse hippocampal HT22 neuron line were used as in vivo and in vitro models of IS injury, respectively. miR-671-5p agomir, miR-671-5p antagomir, pcDNA3.1-NF-κB, and negative controls were transfected into cells using riboFECT CP reagent. miR-671-5p agomir, pcDNA3.1-NF-κB, and negative vectors were administered into MCAO/R mice via intracerebroventricular injection. The results showed that miR-671-5p was significantly downregulated and that miR-671-5p agomir alleviated injury and neuroinflammation induced by ischemic reperfusion. A dual-luciferase reporter assay confirmed that NF-κB is a direct target of miR-671-5p. Reverse experiments showed that miR-671-5p agomir reduced neuroinflammation via suppression of NF-κB expression in both in vitro and in vivo models of IS. Our data suggest that miR-671-5p may be a viable therapeutic target for diminishing neuroinflammation in patients with IS.

Microvascular basis of cognitive impairment in type 1 diabetes

The complex computations of the brain require a constant supply of blood flow to meet its immense metabolic needs. Perturbations in blood supply, even in the smallest vascular networks, can have a profound effect on neuronal function and cognition. Type 1 diabetes is a prevalent and insidious metabolic disorder that progressively and heterogeneously disrupts vascular signalling and function in the brain. As a result, it is associated with an array of adverse vascular changes such as impaired regulation of vascular tone, pathological neovascularization and vasoregression, capillary plugging and blood brain barrier disruption. In this review, we highlight the link between microvascular dysfunction and cognitive impairment that is commonly associated with type 1 diabetes, with the aim of synthesizing current knowledge in this field.

Targeting tumor vascularization: promising strategies for vascular normalization

Tumor recurrence after the clinical cure of tumor often results from the presence of an abnormal microenvironment, including an aberrant vasculature. The tumor microenvironment is rich in pro-angiogenic factors but lacks pro-maturation factors. Pro-angiogenic conditions in the tumor microenvironment, such as hypoxia, are double-edged swords, promoting both the repair of normal tissues and the development of an abnormal blood vessel network. The coexistence of perfusion and hypoxic zones and uneven blood vessel distribution in tumor tissues profoundly influence tumor deterioration, recurrence, and metastasis. Traditional anti-angiogenic therapies have shown limited efficacy, and promote drug resistance, and even metastasis. In contrast, vascular normalization therapy induces a more physiological-like state, leading to better outcomes and fewer side effects. Vascular normalization entails modifying the tumor vascular system to improve tumor oxygenation and substance transport, thereby contributing to improving the efficacy of radiotherapy, chemotherapy, and immunotherapy. This review mainly focuses on the process of tumor vascularization; potential therapeutic targets, including cells, metabolism, signaling pathways, and angiogenesis-related genes; and possible strategies to normalize blood vessels through regulating tumor vessel generation, the development of tumor vessels, and blood vessel fusion and pruning.

Therapeutic Effects of Decursin and Angelica gigas Nakai Root Extract in Gerbil Brain after Transient Ischemia via Protecting BBB Leakage and Astrocyte Endfeet Damage

Angelica gigas Nakai root contains decursin which exerts beneficial properties such as anti-amnesic and anti-inflammatory activities. Until now, however, the neuroprotective effects of decursin against transient ischemic injury in the forebrain have been insufficiently investigated. Here, we revealed that post-treatment with decursin and the root extract saved pyramidal neurons in the hippocampus following transient ischemia for 5 min in gerbil forebrain. Through high-performance liquid chromatography, we defined that decursin was contained in the extract as 7.3 ± 0.2%. Based on this, we post-treated with 350 mg/kg of extract, which is the corresponding dosage of 25 mg/kg of decursin that exerted neuroprotection in gerbil hippocampus against the ischemia. In addition, behavioral tests were conducted to evaluate ischemia-induced dysfunctions via tests of spatial memory (by the 8-arm radial maze test) and learning memory (by the passive avoidance test), and post-treatment with the extract and decursin attenuated ischemia-induced memory impairments. Furthermore, we carried out histochemistry, immunohistochemistry, and double immunohistofluorescence. Pyramidal neurons located in the subfield cornu ammonis 1 (CA1) among the hippocampal subfields were dead at 5 days after the ischemia; however, treatment with the extract and decursin saved the pyramidal neurons after ischemia. Immunoglobulin G (IgG, an indicator of extravasation), which is not found in the parenchyma in normal brain tissue, was apparently shown in CA1 parenchyma from 2 days after the ischemia, but IgG leakage was dramatically attenuated in the CA1 parenchyma treated with the extract and decursin. Furthermore, astrocyte endfeet, which are a component of the blood–brain barrier (BBB), were severely damaged at 5 days after the ischemia; however, post-treatment with the extract and decursin dramatically attenuated the damage of the endfeet. In brief, therapeutic treatment of the extract of Angelica gigas Nakai root and decursin after 5 min transient forebrain ischemia protected hippocampal neurons from the ischemia, showing that ischemia-induced BBB leakage and damage of astrocyte endfeet was significantly attenuated by the extract and decursin. Based on these findings, we suggest that Angelica gigas Nakai root containing decursin can be employed as a pharmaceutical composition to develop a therapeutic strategy for brain ischemic injury.

Anagliptin Protected against Hypoxia/Reperfusion-Induced Brain Vascular Endothelial Permeability by Increasing ZO-1

BACKGROUND AND PURPOSE

Cerebral ischemia-reperfusion injury is commonly induced during the treatment of ischemic stroke and is reported to be related to the blood-brain barrier destruction and brain vascular endothelial cell dysfunction. Anagliptin is a novel antidiabetic agent recently reported to protect neurons from oxidative stress. In the present study, we aim to investigate the protective property of anagliptin against oxygen-glucose deprivation and reperfusion (OGD/R)-induced injury on endothelial cells and clarify the potential underlying mechanism.

METHODS

OGD/R modeling was established on bEnd.3 brain endothelial cells. Cell viability was detected using the MTT assay, and the mitochondrial reactive oxygen species (ROS) level was measured using the mitoses red staining assay. The endothelial monolayer permeability was determined using an FITC-dextran permeation assay. The expression levels of NOX-4 and ZO-1 were evaluated using qRT-PCR and Western blot assays. The expressions of MLC-2, p-MLC-2, and myosin light chain kinase (MLCK) were determined using Western blot.

RESULTS

First, the decreased cell viability, upregulated NOX-4, and elevated mitochondrial ROS level in the endothelial cells induced by OGD/R were reversed by treatment with anagliptin. Second, the enlarged endothelial permeability and the decreased expression level of ZO-1 in the endothelial cells induced by OGD/R were alleviated by anagliptin. Third, the downregulation of ZO-1 and enlarged brain endothelial monolayer permeability induced by OGD/R were ameliorated by an MLCK inhibitor, ML-7. Lastly, the elevated expressions of MLCK and p-MLC-2 induced by OGD/R were suppressed by anagliptin.

CONCLUSION

Anagliptin protected against hypoxia/reperfusion-induced brain vascular endothelial permeability by increasing the expression ZO-1, mediated by inhibition of the MLCK/MLC-2 signaling pathway.

Participation of Amyloid and Tau Protein in Post-Ischemic Neurodegeneration of the Hippocampus of a Nature Identical to Alzheimer's Disease

Recent evidence suggests that amyloid and tau protein are of vital importance in post-ischemic death of CA1 pyramidal neurons of the hippocampus. In this review, we summarize protein alterations associated with Alzheimer's disease and their gene expression (amyloid protein precursor and tau protein) after cerebral ischemia, as well as their roles in post-ischemic hippocampus neurodegeneration. In recent years, multiple studies aimed to elucidate the post-ischemic processes in the development of hippocampus neurodegeneration. Their findings have revealed the dysregulation of genes for amyloid protein precursor, β-secretase, presenilin 1 and 2, tau protein, autophagy, mitophagy, and apoptosis identical in nature to Alzheimer's disease. Herein, we present the latest data showing that amyloid and tau protein associated with Alzheimer's disease and their genes play a key role in post-ischemic neurodegeneration of the hippocampus with subsequent development of dementia. Therefore, understanding the underlying process for the development of post-ischemic CA1 area neurodegeneration in the hippocampus in conjunction with Alzheimer's disease-related proteins and genes will provide the most important therapeutic development goals to date.

The protective effects of curcumin in cerebral ischemia and reperfusion injury through PKC-θ signaling

Ischemic stroke is a common cerebrovascular disease with the main cause considered to be cerebral ischemia and reperfusion (I/R), which exerts irreparable injury on nerve cells. Thus, the development of neuroprotective drugs is an urgent concern. Curcumin, a known antioxidant, has been found to have neuroprotective effects. To determine the protective mechanism of curcumin in ischemic stroke, oxygen and glucose deprivation/reoxygenation (OGD/R) was used to treat PC12 cells to mimic the cerebral I/R cell model. Curcumin (20 μM) was applied to OGD/R PC12 cells, followed by Ca²⁺ concentration, transepithelial electrical resistance (TEER), and cell permeability measurements. The results showed that OGD/R injury induced a decrease in TEER and increases in Ca²⁺ concentration and cell permeability. In contrast, curcumin alleviated these effects. The protein kinase C θ (PKC-θ) was associated with the protective function of curcumin in the OGD/R cell model. Moreover, the middle cerebral artery occlusion and reperfusion model (MCAO/R) was applied to simulate the I/R rat model. Our results demonstrated that curcumin could reverse the MCAO/R-induced increase in Ca²⁺ concentration and blood-brain barrier (BBB) disruption. Our study demonstrates the mechanisms by which curcumin exhibited a protective function against cerebral I/R through PKC-θ signaling by reducing BBB dysfunction.

LncRNA SNHG15 Knockdown Protects Against OGD/R-Induced Neuron Injury by Downregulating TP53INP1 Expression via Binding to miR-455-3p

Cerebral ischemia-reperfusion (I/R) injury is the common symptom of ischemic stroke, which poses a heavy burden to human health. Long non-coding RNA (lncRNA) is indicated to be a critical regulator in cerebral ischemia. This study aims to reveal the effects of lncRNA small nucleolar RNA host gene 15 (SNHG15) on oxygen-glucose deprivation and reoxygenation (OGD/R)-induced neuron injury and underlying mechanism. The expression levels of SNHG15, microRNA-455-3p (miR-455-3p) and tumour protein p53 inducible nuclear protein 1 (TP53INP1) mRNA were determined by quantitative real time polymerase chain reaction in P12 cells. The protein levels of TP53INP1, cleaved caspase-3, caspase-3, B-cell lymphoma-2 and BCL2-associated x protein (Bax) were detected by western blot in P12 cells. Cell viability and apoptosis were revealed by cell counting kit-8 assay and flow cytometry analysis, respectively, in P12 cells. Caspase-3 activity, the levels of tumor necrosis factor-α and interleukin-1β and the production of reactive oxygen species (ROS) were severally determined by caspase-3 activity assay, Enzyme-linked immunosorbent assay and ROS detection assay in P12 cells. The binding relationship between miR-455-3p and SNHG15 or TP53INP1 was predicted by starbase online database, and identified by dual-luciferase reporter, RNA pull-down or RNA immunoprecipitation assay. SNHG15 expression and the mRNA and protein levels of TP53INP1 were dramatically upregulated, while miR-455-3p expression was apparently downregulated in OGD/R-induced PC12 cells. SNHG15 silencing hindered the effects of OGD/R treatment on cell viability, apoptosis, inflammation and oxidative in PC12 cells; however, these impacts were restored after miR-455-3p inhibitor transfection. Additionally, SNHG15 acted as a sponge of miR-455-3p and miR-455-3p bound to TP53INP1. SNHG15 contributed to OGD/R-induced neuron injury by regulating miR-455-3p/TP53INP1 axis, which provided a novel insight to study lncRNA-directed therapy in ischemia stoke.

CU06-1004-Induced Vascular Normalization Improves Immunotherapy by Modulating Tumor Microenvironment via Cytotoxic T Cells

Blocking the immune evasion mechanism of tumor cells has become an attractive means for treating cancers. However, the usage of a drug such as nivolumab (αPD-1), which blocks programmed cell death protein 1 (PD-1), turned out to be only effective against certain types of cancer. Especially, vascular abnormal structures of which deter delivery route by leakage and cause the poor perfusion were considered to be environment unfavorable to T cells and immune checkpoint blockade (ICB) delivery within the tumor microenvironment (TME). Herein, we report stabilization of tumor blood vessels by endothelial dysfunctional blocker CU06-1004, which modified the TME and showed synergistic effects with immunotherapy anti-PD-1 antibody. CU06-1004 combination therapy consistently prolonged the survival of tumor-bearing mice by decreasing tumor growth. T-cell infiltration increased in the tumors of the combination group, with cytotoxic CD8⁺ T cell activity within the tumor parenchyma upregulated compared with anti-PD-1 monotherapy. Tumor inhibition was associated with reduced hypoxia and reduced vessel density in the central region of the tumor. These effects correlated significantly with enhanced expression of IFN gamma and PD-L1 in tumors. Taken together, our findings suggest that CU06-1004 is a potential candidate drug capable of improving therapeutic efficacy of anti-PD-1 through beneficial changes in the TME.

4-Methoxybenzylalcohol protects brain microvascular endothelial cells against oxygen-glucose deprivation/reperfusion-induced injury via activation of the PI3K/AKT signaling pathway

Damage to the blood-brain barrier (BBB) during the process of cerebral ischemic injury is a key factor that affects the treatment of this condition. The present study aimed to assess the potential effects of 4-methoxybenzyl alcohol (4-MA) on brain microvascular endothelial cells (bEnd.3) against oxygen-glucose deprivation/reperfusion (OGD/Rep) using an in vitro model that mimics in vivo ischemia/reperfusion injury. In addition, the present study aimed to explore whether this underlying mechanism was associated with the inhibition of pro-inflammatory factors and the activation status of the PI3K/Akt signaling pathway. bEnd.3 cells were subjected to OGD/Rep-induced injury before being treated with 4-MA, following which cell viability, lactate dehydrogenase (LDH) release and levels of nitric oxidase (NO) were detected by colorimetry, pro-inflammatory factors including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6, were detected by ELISA. The expression levels of occluding and claudin-5were evaluated by immunofluorescence staining. The expression levels of AKT, phosphorylated (p)-Akt, endothelial nitric oxide synthase (eNOS) and p-eNOS were also measured by western blot analysis. After bEnd.3 cells were subjected to OGD/Rep-induced injury, cell viability and NO levels were significantly decreased, whilst LDH leakage and inflammatory factor (TNF-α, IL-1β and IL-6) levels were significantly increased. Treatment with 4-MA significantly ameliorated cell viability, LDH release and the levels of NO and pro-inflammatory factors TNF-α, IL-1β and IL-6 as a result of OGD/Rep. Furthermore, treatment with 4-MA upregulated the expression of occludin, claudin-5, Akt and eNOS, in addition to increasing eNOS and AKT phosphorylation in bEnd.3 cells. These results suggest that 4-MA can alleviate OGD/Rep-induced injury in bEnd.3 cells by inhibiting inflammation and by activating the PI3K/AKT signaling pathway as a possible mechanism. Therefore, 4-MA can serve as a potential candidate for treating OGD/Rep-induced injury.

The endothelial dysfunction blocker CU06-1004 ameliorates choline-deficient L-amino acid diet-induced non-alcoholic steatohepatitis in mice

Non-alcoholic steatohepatitis (NASH) is a severe, advanced form of non-alcoholic fatty liver disease (NAFLD) that is associated with features of metabolic syndrome and characterized by hepatic steatosis, inflammation, and fibrosis. In addition, NASH is associated with endothelial dysfunction within the hepatic vasculature. Treatment with CU06-1004 (previously called Sac-1004) ameliorates endothelial dysfunction by inhibiting hyperpermeability and inflammation. In this study, we investigated the protective effects of CU06-1004 in a choline-deficient L-amino acid (CDAA)-induced mouse model of NASH for 3 or 6 weeks. Specifically, we evaluated the effects of CU06-1004 on lipid accumulation, inflammation, hepatic fibrosis, and liver sinusoidal endothelial cell (LSEC) capillarization through biochemical analysis, immunohistochemistry, and real-time PCR. We found that the administration of CU06-1004 to mice improved liver triglyceride (TG) and serum alanine aminotransferase (ALT) in this CDAA-induced model of NASH for 6 weeks. In groups of NASH induced mice for both 3 and 6 weeks, CU06-1004 significantly reduced the hepatic expression of genes related to lipogenesis, inflammation, and cell adhesion. However, expression of genes related to hepatic fibrosis and vascular endothelial changes were only decreased in animals with mild NASH. These results suggest that the administration of CU06-1004 suppresses hepatic steatosis, inflammation, fibrosis, and LSEC capillarization in a CDAA-induced mouse model of NASH. This suggests that CU06-1004 has therapeutic potential for the treatment of mild NASH.

Burns Impair Blood-Brain Barrier and Mesenchymal Stem Cells Can Reverse the Process in Mice

Neurological syndromes are observed in numerous patients who suffer burns, which add to the economic burden of societies and families. Recent studies have implied that blood-brain barrier (BBB) dysfunction is the key factor that induces these central nervous system (CNS) syndromes in peripheral traumatic disease, e.g., surgery and burns. However, the effect of burns on BBB and the underlying mechanism remains, largely, to be determined. The present study aimed to investigate the effect of burns on BBB and the potential of umbilical cord-derived mesenchymal stem cells (UC-MSCs), which have strong anti-inflammatory and repairing ability, to protect the integrity of BBB. BBB permeability was evaluated using dextran tracer (immunohistochemistry imaging and spectrophotometric quantification) and western blot, interleukin (IL)-6, and IL-1β levels in blood and brain were measured by enzyme-linked immunosorbent assay. Furthermore, transmission electron microscopy (TEM) was used to detect transcellular vesicular transport (transcytosis) in BBB. We found that burns increased mouse BBB permeability to both 10-kDa and 70-kDa dextran. IL-6 and IL-1β levels increased in peripheral blood and CNS after burns. In addition, burns decreased the level of tight junction proteins (TJs), including claudin-5, occludin, and ZO-1, which indicated increased BBB permeability due to paracellular pathway. Moreover, increased vesicular density after burns suggested increased transcytosis in brain microvascular endothelial cells. Finally, administering UC-MSCs at 1 h after burns effectively reversed these adverse effects and protected the integrity of BBB. These results suggest that burns increase BBB permeability through both paracellular pathway and transcytosis, the potential mechanism of which might be through increasing IL-6 and IL-1β levels and decreasing Mfsd2a level, and appropriate treatment with UC-MSCs can reverse these effects and protect the integrity of BBB after burns.

Neuronal Epac1 mediates retinal neurodegeneration in mouse models of ocular hypertension

Progressive loss of retinal ganglion cells (RGCs) leads to irreversible visual deficits in glaucoma. Here, we found that the level of cyclic AMP and the activity and expression of its mediator Epac1 were increased in retinas of two mouse models of ocular hypertension. Genetic depletion of Epac1 significantly attenuated ocular hypertension–induced detrimental effects in the retina, including vascular inflammation, neuronal apoptosis and necroptosis, thinning of ganglion cell complex layer, RGC loss, and retinal neuronal dysfunction. With bone marrow transplantation and various Epac1 conditional knockout mice, we further demonstrated that Epac1 in retinal neuronal cells (especially RGCs) was responsible for their death. Consistently, pharmacologic inhibition of Epac activity prevented RGC loss. Moreover, in vitro study on primary RGCs showed that Epac1 activation was sufficient to induce RGC death, which was mechanistically mediated by CaMKII activation. Taken together, these findings indicate that neuronal Epac1 plays a critical role in retinal neurodegeneration and suggest that Epac1 could be considered a target for neuroprotection in glaucoma.

Eupafolin alleviates cerebral ischemia/reperfusion injury in rats via blocking the TLR4/NF‑κB signaling pathway

Eupatorium perfoliatum L. (E. perfoliatium) has been used traditionally for treating fever, malaria and inflammation‑associated diseases. Eupafolin, the extract of E. perfoliatium, was also reported to suppress inflammation. The present study aimed to investigate the protective effects of eupafolin on cerebral ischemia/reperfusion (I/R) injury in rats and its possible underlying mechanisms. Cerebral I/R injury was induced in rats by middle cerebral artery occlusion (MCAO) for 1.5 h, followed by reperfusion. The rats were randomly assigned into six groups: Control, model, 10 mg/kg eupafolin, 20 mg/kg eupafolin, 50 mg/kg eupafolin and 20 mg/kg nimodipine. Eupafolin and nimodipine were intragastrically administrated to the rats 1 week before MCAO induction. Following reperfusion for 24 h, the neurological deficit was scored, and brain samples were harvested for evaluating encephaledema, infarct volume, oxidative stress, apoptosis, inflammation and the expression of TLR4/NF‑κB signaling. The results revealed that eupafolin decreased the neurological score, relieved encephaledema and decreased infarct volume. Eupafolin also attenuated oxidative stress, neuronal apoptosis and inflammation, with decreases in lactate dehydrogenase, malondialdehyde, TUNEL‑positive cells, Bax and caspase‑3, along with TNF‑α, IL‑1β and IL‑6, but increases in superoxide dismutase and Bcl‑2 levels. Furthermore, eupafolin may decrease the expression of TLR4 downstream proteins and proteins involved in the NF‑κB pathway. Treatment with TLR4 agonist‑LPS significantly blunted the protective effect of eupafolin on encephaledema and cerebral infarct. Meanwhile, 20 mg/kg eupafolin showed nearly equivalent effects to the positive‑control drug nimodipine. In conclusion, eupafolin protected against cerebral I/R injury in rats and the underlying mechanism may be associated with the suppression of apoptosis and inflammation via inhibiting the TLR4/ NF‑κB signaling pathway.

Protective effect and mechanism of Qishiwei Zhenzhu pills on cerebral ischemia-reperfusion injury via blood-brain barrier and metabonomics

Stroke is an acute cerebrovascular disease caused by the sudden rupture of cerebral blood vessels or vascular obstruction from brain tissue damage or dysfunction, thereby preventing blood flow into the brain. Cerebral ischemia-reperfusion injury (CI/RI), a common syndrome of ischemic stroke, is a complex pathological process whose physiological mechanism is still unclear. Qishiwei Zhenzhu pills (QSW), a famous Tibetan medicine preparation, has the effect of tranquilizing by heavy settling, dredging channels and activating collaterals, harmonizing Qi and blood, restoring consciousness, and inducing resuscitation. Here, we investigated the protective effect of QSW on CI/RI in rats and its potential mechanism. First, the volatile and liposoluble components in QSW were determined using gas chromatography-mass spectrometry (GCMS). After 24 h of CI/RI, the neuroprotective effect was determined by evaluating the neurological function, cerebral infarction, histopathology, and blood-brain barrier (BBB) function. Immunofluorescence, real-time quantitative PCR (RT-qPCR), and western blot (WB) were used to detect the expression of matrix metalloproteinase 9 (MMP-9), claudin-5, and occludin. Finally, GCMS metabonomics was used to identify different metabolites and analyze metabolic pathways. The results showed that 88 volatile components and 63 liposoluble components were detected in QSW. Following the experimental stroke operation, it was observed that rats administered QSW pretreatment had improved neurological function, reduced infarct volume (P < 0.01), increased Nissl bodies (P < 0.05), improved histopathology, and reduced BBB disruption. Immunofluorescence, RT-qPCR, and WB results showed that MMP-9 level in the brain tissue of the QSW pretreatment group had a decreasing trend and the expression of claudin-5 and occludin had a tendency to increase. Eleven metabolites related to lipid metabolism, fatty acid metabolism, and energy metabolism, were identified via GC-MS metabonomics. Our study shows that QSW preconditioning has a neuroprotective effect on CI/RI; however, its mechanism requires further study.

CU06-1004 Alleviates Experimental Colitis by Modulating Colonic Vessel Dysfunction

Inflammatory bowel disease is an autoimmune disease that causes chronic inflammation of the gastrointestinal tract. Endothelial dysfunction, defined by a reduced endothelial barrier and an increase in the expression of adhesion molecules, is part of the pathology of inflammatory bowel disease. In this study, we assessed the therapeutic effect of CU06-1004, an endothelial dysfunction blocker that reduces vascular hyperpermeability and inflammation in a mouse model of colitis. Acute colitis was induced in mice using 3% (w/v) dextran sodium sulfate added to their drinking water for 7 days. Twenty-four hours after the addition of dextran sodium sulfate, either mesalazine or CU06-1004 was administered orally each day. Administration of CU06-1004 significantly reduced the clinical manifestations (weight loss, diarrhea, and bloody stool) and histological changes (epithelium loss, inflammatory cell infiltration, and crypt destruction) induced by dextran sodium sulfate. Proinflammatory cytokines were also reduced, indicating that inflammation was ameliorated. From a vascular perspective, CU06-1004 reduced interrupted and tortuous vessels, enhanced junction protein expression, and reduced inflammatory adhesion molecules, indicating a broad improvement of endothelial dysfunction. Endothelial protection induced epithelial barrier restoration and decreased epithelial inflammation. Blocking endothelial dysfunction with CU06-1004 significantly ameliorated the progression of inflammatory bowel disease. Therefore, CU06-1004 may represent a potential therapeutic agent for the treatment of inflammatory bowel disease as well as other inflammatory diseases.

Experimental Pretreatment with Chlorogenic Acid Prevents Transient Ischemia-Induced Cognitive Decline and Neuronal Damage in the Hippocampus through Anti-Oxidative and Anti-Inflammatory Effects

Chlorogenic acid (CGA), an ester of caffeic acid and quinic acid, is among the phenolic acid compounds which can be naturally found in green coffee extract and tea. CGA has been studied since it displays significant pharmacological properties. The aim of this study was to investigate the effects of CGA on cognitive function and neuroprotection including its mechanisms in the hippocampus following transient forebrain ischemia in gerbils. Memory and learning following the ischemia was investigated by eight-arm radial maze and passive avoidance tests. Neuroprotection was examined by immunohistochemistry for neuronal nuclei-specific protein and Fluoro-Jade B histofluorescence staining. For mechanisms of the neuroprotection, alterations in copper, zinc-superoxide dismutase (SOD1), SOD2 as antioxidant enzymes, dihydroethidium and 4-hydroxy-2-nonenal as indicators for oxidative stress, and anti-inflammatory cytokines (interleukin (IL)-4 and IL-13) and pro-inflammatory cytokines (tumor necrosis factor α (TNF-α) and IL-2) were examined by Western blotting and/or immunohistochemistry. As a result, pretreatment with 30 mg/kg CGA attenuated cognitive impairment and displayed a neuroprotective effect against transient forebrain ischemia (TFI). In Western blotting, the expression levels of SOD2 and IL-4 were increased due to pretreatment with CGA and, furthermore, 4-HNE production and IL-4 expressions were inhibited by CGA pretreatment. Additionally, pretreated CGA enhanced antioxidant enzymes and anti-inflammatory cytokines and, in contrast, attenuated oxidative stress and pro-inflammatory cytokine expression. Based on these results, we suggest that CGA can be a useful neuroprotective material against ischemia-reperfusion injury due to its antioxidant and anti-inflammatory efficacies.

Brain Factor-7® improves learning and memory deficits and attenuates ischemic brain damage by reduction of ROS generation in stroke in vivo and in vitro

Brain Factor-7® (BF-7), silk fibroin peptide, is known to be effective in improvement of memory and learning ability. In this study, the effects of BF-7 (10 mg/kg, p.o., pre-treatment for 7 days and post-treatment for 7 days) on neuroprotection and memory and learning functions were investigated in a rat model of transient focal cerebral ischemia and a gerbil model of transient global forebrain ischemia. Furthermore, to find the mechanism of BF-7, we examined the neuroprotective and antioxidative effects of BF-7 in vitro using neuroblastoma (SH-SY5Y) cells. In vivo model, treatment with BF-7 significantly reduced the number of errors in 8-arm maze test and significantly increased latency time in passive avoidance test at 7 days after focal ischemia compared to those in the vehicle-treated group. In addition, treatment with BF-7 significantly decreased the infarct size or neuronal death at 7 day following transient ischemia compared to that in the vehicle-treated group. In vitro model, 10 or 20 μg/ml of BF-7 treatment significantly increased cell viability in dose-dependent manner. In addition, oxidative stress was significantly attenuated in the ischemic cells, showing that 10 or 20 μg/ml of BF-7 treatment significantly reduced the generation of reactive oxygen species (ROS) compared to that in the ischemic cells. These results indicate that BF-7 treatment can attenuate ischemic damages and improve memory deficits via reduction of ROS generation.

Long-Term Alternating Fasting Increases Interleukin-13 in the Gerbil Hippocampus, But Does Not Protect BBB and Pyramidal Neurons From Ischemia-Reperfusion Injury

It is questionable whether intermittent fasting (IF) protects against brain ischemic injury. This study examined whether IF increased anti-inflammatory cytokines and protected neurons from ischemia-reperfusion injury in the gerbil hippocampus. Gerbils were subjected to 1-day alternating fasting as IF for 1, 2, or 3 months and assigned to sham or 5 min of transient ischemia. We examined the changes in anti-inflammatory cytokines (IL-4 and IL-13), neurons and IgG by immunohistochemistry or immunofluorescence staining in the cornu ammonis 1 (CA1) region of the hippocampus before and after ischemia. IF increased IL-13 immunoreactivity in the CA1 region before ischemia, but did not affect IL-4 immunoreactivity. After ischemia, IL-13 and 4 immunoreactivities in the CA1 region were significantly lower in IF gerbils than in non-IF gerbils. In the IF gerbils, the CA1 pyramidal neurons were not protected from ischemic injury; in these gerbils, strong IgG immunoreactivity was seen in the CA1 parenchyma, indicating leakage of the BBB. In brief, IF increased IL-13 in the CA1 region, but these neurons were not protected from transient ischemic injury evidenced by IgG immunoreactivity in the CA1 parenchyma. This study indicates that IF increased some anti-inflammatory cytokines but did not afford neuroprotection against ischemic insults via BBB disruption.

CU06-1004 (endothelial dysfunction blocker) ameliorates astrocyte end-feet swelling by stabilizing endothelial cell junctions in cerebral ischemia/reperfusion injury

Cerebral ischemia, or stroke, is widespread leading cause of death and disability. Surgical and pharmacological interventions that recover blood flow are the most effective treatment strategies for stroke patients. However, restoring the blood supply is accompanied by severe reperfusion injury, with edema and astrocyte end-feet disruption. Here, we report that the oral administration of CU06-1004 (previously Sac-1004), immediately after onset of ischemia/reperfusion (I/R), ameliorated cerebral damage. CU06-1004 stabilized blood‑brain barrier by inhibiting the disruption of the tight junction-related protein zona occludens-1 and the cortical actin ring in endothelial cells (ECs) after I/R. Interestingly, CU06-1004 significantly suppressed astrocyte end-feet swelling following I/R, by reducing aquaporin 4 and connexin 43 levels, which mediates swelling. Furthermore, the degradation of β1-integrin and β-dystroglycan, which anchors to the cortical actin ring in ECs, was inhibited by CU06-1004 administration after I/R. Consistently, CU06-1004 administration following I/R also suppressed the loss of laminin and collagen type IV, which bind to the cortical actin ring anchoring proteins. Unlike the protective effects of CU06-1004 in ECs, astrocyte viability and proliferation were not directly affected. Taken together, our observations suggest that CU06-1004 inhibits I/R-induced cerebral edema and astrocyte end-feet swelling by maintaining EC junction stability. KEY MESSAGES: • CU06-1004 ameliorates I/R-induced cerebral injury. • EC junction integrity was stabilized by CU06-1004 treatment after I/R. • CU06-1004 reduces astrocyte end-feet swelling following I/R. • EC junction stability affects astrocyte end-feet structure maintenance after I/R.

Mechanism of blood-brain barrier disruption by an Escherichia coli from lambs with severe diarrhea and meningoencephalitis

Escherichia coli (E. coli) is a common conditional pathogen that is associated with a variety of infections in humans and animals. Although there are increasing reports regarding the infection of E. coli to domestic animals and poultry, the infection of E. coli in lambs is relatively less reported, especially on meningoencephalitis. Here, we reported the isolation of an E. coli strain designated as NMGCF-19 from lambs characterized with severe diarrhea and neurological disorder, and demonstrated that NMGCF-19 as the causative agent has the ability to disrupt the blood-brain barrier (BBB) to cause the meningoencephalitis using a mouse model. Investigation on the mechanism regarding the NMGCF-19-related meningoencephalitis revealed a significant decreased expression of ZO-1 and occludin in mouse brain tissue in comparison with the control mice. Moreover, infection of NMGCF-19 increased the expression of proinflammatory cytokines TNF-α, IL-6, IL-1β and IL-18, up-regulated HMGB1 level, and activated TLR2/TLR4/MyD88 and NLRP3 inflammasome pathways. These findings indicated that NMGCF-19 likely invades the brain tissue by disrupting the tight junction (TJ) architecture and causes the meningoencephalitis via increasing inflammatory response and activating TLR2/TLR4/MyD88 and NLRP3 inflammasome pathways.

Laminarin Pretreatment Provides Neuroprotection against Forebrain Ischemia/Reperfusion Injury by Reducing Oxidative Stress and Neuroinflammation in Aged Gerbils

Laminarin is a polysaccharide isolated from brown algae that has various biological and pharmacological activities, such as antioxidant and anti-inflammatory properties. We recently reported that pretreated laminarin exerted neuroprotection against transient forebrain ischemia/reperfusion (IR) injury when we pretreated with 50 mg/kg of laminarin once a day for seven days in adult gerbils. However, there have been no studies regarding a neuroprotective effect of pretreated laminarin against IR injury in aged animals and its related mechanisms. Therefore, in this study, we intraperitoneally inject laminarin (50 mg/kg) once a day to aged gerbils for seven days before IR (5-min transient ischemia) surgery and examine the neuroprotective effect of laminarin treatment and the mechanisms in the gerbil hippocampus. IR injury in vehicle-treated gerbils causes loss (death) of pyramidal neurons in the hippocampal CA1 field at five days post-IR. Pretreatment with laminarin effectively protects the CA1 pyramidal neurons from IR injury. Regarding the laminarin-treated gerbils, production of superoxide anions, 4-hydroxy-2-nonenal expression and pro-inflammatory cytokines [interleukin(IL)-1β and tumor necrosis factor-α] expressions are significantly decreased in the CA1 pyramidal neurons after IR. Additionally, laminarin treatment significantly increases expressions of superoxide dismutase and anti-inflammatory cytokines (IL-4 and IL-13) in the CA1 pyramidal neurons before and after IR. Taken together, these findings indicate that laminarin can protect neurons from ischemic brain injury in an aged population by attenuating IR-induced oxidative stress and neuroinflammation.

XingNaoJing injections protect against cerebral ischemia/reperfusion injury and alleviate blood-brain barrier disruption in rats, through an underlying mechanism of NLRP3 inflammasomes suppression

The aim of this study was to explore the neuroprotective effect and mechanism of XingNaoJing injections (XNJ) on cerebral ischemia injury and blood-brain barrier (BBB) disruption. Middle cerebral artery occlusion (MCAO) method was applicated to establish the model of cerebral ischemia/reperfusion (I/R) injury in rats. BBB permeability after I/R injury was assessed with the leaking amount of Evans Blue and the expression of occludin and ZO-1. The expression of NOD-like receptor family, pyrin domain containing (NLRP3) was checked to explore the inhibition of inflammation by XNJ. The results showed that XNJ could significantly increase the survival percent, decrease the infarct area and ameliorate neurological deficits and brain damage after I/R injury. Leaking amount of Evans Blue was reduced by XNJ, and the expression of tight junction protein, occludin and ZO-1 was also up-regulated by XNJ, which showed a role of protection on BBB disruption. The expression of NLRP3 was inhibited after exposure of XNJ, which was associated with inhibition of the inflammatory response. In summary, XNJ could suppress NLRP3 inflammasomes and improve BBB disruption and brain damage in rats after cerebral I/R injury, which provided a beneficial insight to further explore XNJ.

YES-10, A Combination of Extracts from Clematis mandshurica RUPR. and Erigeron annuus (L.) PERS., Prevents Ischemic Brain Injury in A Gerbil Model of Transient Forebrain Ischemia

: Clematis mandshurica RUPR. (CMR) and Erigeron annuus (L.) PERS. (EALP) have pharmacological effects including anti-inflammatory activity and been used in traditional medicines in Asia. However, neuroprotective effects of CMR and/or EALP extracts against brain ischemic insults have never been addressed. Thus, the aim of this study was to examine neuroprotective effects of YES-10, a combination of extracts from CMR and EALP (combination ratio, 1:1), in the hippocampus following ischemia/reperfusion in gerbils. Protection of neurons was investigated by cresyl violet staining, fluoro-jade B histofluorescence staining and immunohistochemistry for neuronal nuclei. In addition, attenuation of gliosis was studied by immunohistochemistry for astrocytic and microglial markers. Treatments with 50 or 100 mg/kg YES-10 failed to protect neurons in the hippocampus after ischemia/reperfusion injury. However, administration of 200 mg/kg YES-10 protected neurons from ischemia/reperfusion injury and attenuated reactive gliosis. These findings strongly suggest that a combination of extracts from CMR and EALP can be used as a prevention approach/drug against brain ischemic damage.

Pre-Treatment with Laminarin Protects Hippocampal CA1 Pyramidal Neurons and Attenuates Reactive Gliosis Following Transient Forebrain Ischemia in Gerbils

Transient brain ischemia triggers selective neuronal death/loss, especially in vulnerable regions of the brain including the hippocampus. Laminarin, a polysaccharide originating from brown seaweed, has various pharmaceutical properties including an antioxidant function. To the best of our knowledge, few studies have been conducted on the protective effects of laminarin against ischemic injury induced by ischemic insults. In this study, we histopathologically investigated the neuroprotective effects of laminarin in the Cornu Ammonis 1 (CA1) field of the hippocampus, which is very vulnerable to ischemia-reperfusion injury, following transient forebrain ischemia (TFI) for five minutes in gerbils. The neuroprotective effect was examined by cresyl violet staining, Fluoro-Jade B histofluorescence staining and immunohistochemistry for neuronal-specific nuclear protein. Additionally, to study gliosis (glial changes), we performed immunohistochemistry for glial fibrillary acidic protein to examine astrocytes, and ionized calcium-binding adaptor molecule 1 to examine microglia. Furthermore, we examined alterations in pro-inflammatory M1 microglia by using double immunofluorescence. Pretreatment with 10 mg/kg laminarin failed to protect neurons in the hippocampal CA1 field and did not attenuate reactive gliosis in the field following TFI. In contrast, pretreatment with 50 or 100 mg/kg laminarin protected neurons, attenuated reactive gliosis and reduced pro-inflammatory M1 microglia in the CA1 field following TFI. Based on these results, we firmly propose that 50 mg/kg laminarin can be strategically applied to develop a preventative against injuries following cerebral ischemic insults.

Recent progress regarding kaempferol for the treatment of various diseases

Kaempferol, also known as kaempferol-3 or kaempferide, is a flavonoid compound that naturally occurs in tea, as well as numerous common vegetables and fruits, including beans, broccoli, cabbage, gooseberries, grapes, kale, strawberries, tomatoes, citrus fruits, brussel sprouts, apples and grapefruit. The present review mainly summarizes the application of kaempferol in treating diseases and the underlying mechanisms that are currently being studied. Due to its anti-inflammatory properties, it may be used to treat numerous acute and chronic inflammation-induced diseases, including intervertebral disc degeneration and colitis, as well as post-menopausal bone loss and acute lung injury. In addition, it has beneficial effects against cancer, liver injury, obesity and diabetes, inhibits vascular endothelial inflammation, protects the cranial nerve and heart function, and may be used for treating fibroproliferative disorders, including hypertrophic scar.