B355252 Suppresses LPS-Induced Neuroinflammation in the Mouse Brain.

B355252 is a small molecular compound known for potentiating neural growth factor and protecting against neuronal cell death induced by glutamate in vitro and cerebral ischemia in vivo. However, its other biological functions remain unclear. This study aims to investigate whether B355252 suppresses neuroinflammatory responses and cell death in the brain. C57BL/6j mice were intraperitoneally injected with a single dosage of lipopolysaccharide (LPS, 1 mg/kg) to induce inflammation. B355252 (1 mg/kg) intervention was started two days prior to the LPS injection. The animal behavioral changes were assessed pre- and post-LPS injections. The animal brains were harvested at 4 and 24 h post-LPS injection, and histological, biochemical, and cytokine array outcomes were examined. Results showed that B355252 improved LPS-induced behavioral deterioration, mitigated brain tissue damage, and suppressed the activation of microglial and astrocytes. Furthermore, B355252 reduced the protein levels of key pyroptotic markers TLR4, NLRP3, and caspase-1 and inhibited the LPS-induced increases in IL-1ß, IL-18, and cytokines. In conclusion, B355252 demonstrates a potent anti-neuroinflammatory effect in vivo, suggesting that its potential therapeutic value warrants further investigation.

N6022 attenuates cerebral ischemia/reperfusion injury-induced microglia ferroptosis by promoting Nrf2 nuclear translocation and inhibiting the GSNOR/GSTP1 axis.

Stroke poses a significant risk of mortality, particularly among the elderly population. The pathophysiological process of ischemic stroke is complex, and it is crucial to elucidate its molecular mechanisms and explore potential protective drugs. Ferroptosis, a newly recognized form of programmed cell death distinct from necrosis, apoptosis, and autophagy, is closely associated with the pathophysiology of ischemic stroke. N6022, a selective inhibitor of S-nitrosoglutathione reductase (GSNOR), is a "first-in-class" drug for asthma with potential therapeutic applications. However, it remains unclear whether N6022 exerts protective effects in ischemic stroke, and the precise mechanisms of its action are unknown. This study aimed to investigate whether N6022 mitigates cerebral ischemia/reperfusion (I/R) injury by reducing ferroptosis and to elucidate the underlying mechanisms. Accordingly, we established an oxygen-glucose deprivation/reperfusion (OGD/R) cell model and a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to mimic cerebral I/R injury. Our data, both in vitro and in vivo, demonstrated that N6022 effectively protected against I/R-induced brain damage and neurological deficits in mice, as well as OGD/R-induced BV2 cell damage. Mechanistically, N6022 promoted Nrf2 nuclear translocation, enhancing intracellular antioxidant capacity of SLC7A11-GPX4 system. Furthermore, N6022 interfered with the interaction of GSNOR with GSTP1, thereby boosting the antioxidant capacity of GSTP1 and attenuating ferroptosis. These findings provide novel insights, showing that N6022 attenuates microglial ferroptosis induced by cerebral I/R injury through the promotion of Nrf2 nuclear translocation and inhibition of the GSNOR/GSTP1 axis.

Immp2l Mutation Induces Mitochondrial Membrane Depolarization and Complex III Activity Suppression after Middle Cerebral Artery Occlusion in Mice.

OBJECTIVE: We previously reported that mutations in inner mitochondrial membrane peptidase 2-like (Immp2l) increase infarct volume, enhance superoxide production, and suppress mitochondrial respiration after transient cerebral focal ischemia and reperfusion injury. The present study investigated the impact of heterozygous Immp2l mutation on mitochondria function after ischemia and reperfusion injury in mice. METHODS: Mice were subjected to middle cerebral artery occlusion for 1 h followed by 0, 1, 5, and 24 h of reperfusion. The effects of Immp2l+/- on mitochondrial membrane potential, mitochondrial respiratory complex III activity, caspase-3, and apoptosis-inducing factor (AIF) translocation were examined. RESULTS: Immp2l+/- increased ischemic brain damage and the number of TUNEL-positive cells compared with wild-type mice. Immp2l+/- led to mitochondrial damage, mitochondrial membrane potential depolarization, mitochondrial respiratory complex III activity suppression, caspase-3 activation, and AIF nuclear translocation. CONCLUSION: The adverse impact of Immp2l+/- on the brain after ischemia and reperfusion might be related to mitochondrial damage that involves depolarization of the mitochondrial membrane potential, inhibition of the mitochondrial respiratory complex III, and activation of mitochondria-mediated cell death pathways. These results suggest that patients with stroke carrying Immp2l+/- might have worse and more severe infarcts, followed by a worse prognosis than those without Immp2l mutations.

Asialo-rhuEPO as a Potential Neuroprotectant for Ischemic Stroke Treatment.

Neuroprotective drugs to protect the brain against cerebral ischemia and reperfusion (I/R) injury are urgently needed. Mammalian cell-produced recombinant human erythropoietin (rhuEPOM) has been demonstrated to have excellent neuroprotective functions in preclinical studies, but its neuroprotective properties could not be consistently translated in clinical trials. The clinical failure of rhuEPOM was thought to be mainly due to its erythropoietic activity-associated side effects. To exploit its tissue-protective property, various EPO derivatives with tissue-protective function only have been developed. Among them, asialo-rhuEPO, lacking terminal sialic acid residues, was shown to be neuroprotective but non-erythropoietic. Asialo-rhuEPO can be prepared by enzymatic removal of sialic acid residues from rhuEPOM (asialo-rhuEPOE) or by expressing human EPO gene in glycoengineered transgenic plants (asialo-rhuEPOP). Both types of asialo-rhuEPO, like rhuEPOM, displayed excellent neuroprotective effects by regulating multiple cellular pathways in cerebral I/R animal models. In this review, we describe the structure and properties of EPO and asialo-rhuEPO, summarize the progress on neuroprotective studies of asialo-rhuEPO and rhuEPOM, discuss potential reasons for the clinical failure of rhuEPOM with acute ischemic stroke patients, and advocate future studies needed to develop asialo-rhuEPO as a multimodal neuroprotectant for ischemic stroke treatment.

Rapamycin ameliorates brain damage and maintains mitochondrial dynamic balance in diabetic rats subjected to middle cerebral artery occlusion.

To investigate the effect of rapamycin on mitochondrial dynamic balance in diabetic rats subjected to cerebral ischemia-reperfusion injury. Male Sprague Dawley (SD) rats (n = 78) were treated with high fat diet combined with streptozotocin injection to construct diabetic model in rats. Transient middle cerebral artery occlusion (MCAO) of 2 hours was induced and the brains were harvested after 1 and 3 days of reperfusion. Rapamycin was injected intraperitoneally for 3 days prior to and immediately after operation, once a day. The neurological function was assessed, infarct volumes were measured and HE staining as well as immunohistochemistry were performed. The protein of hippocampus was extracted and Western blotting were performed to detect the levels of mTOR, mitochondrial dynamin related proteins (DRP1, p-DRP1, OPA1), SIRT3, and Nix/BNIP3L. Diabetic hyperglycemia worsened the neurological function performance (p < 0.01), enlarged infarct size (p < 0.01) and increased ischemic neuronal cell death (p < 0.01). The increased damage was associated with elevations of p-mTOR, p-S6, and p-DRP1; and suppressions of SIRT3 and Nix/BNIP3L. Rapamycin ameliorated diabetes-enhanced ischemic brain damage and reversed the biomarker alterations caused by diabetes. High glucose activated mTOR pathway and caused mitochondrial dynamics toward fission. The protective effect of rapamycin against diabetes-enhanced ischemic brain damage was associated with inhibiting mTOR pathway, redressing mitochondrial dynamic imbalance, and elevating SIRT3 and Nix/BNIP3L expression.

Downregulation of TRIM33 Promotes Survival and Epithelial-Mesenchymal Transition in Gastric Cancer.

Among all malignancies worldwide, gastric cancer is the fifth most common cancer with the third highest mortality rate. One of the main reasons for the low survival rate is the recurrence and metastasis that occurs in many patients after surgery. Numerous studies have shown that abnormal TRIM33 expression is associated with the progression of malignant tumors. TRIM33 can function either as a tumor suppressor or tumor promoter in different cancers. Our data showed that TRIM33 was highly expressed in stomach cancer, and in human gastric cancer tissues, low expression of TRIM33 was associated with poor prognosis in patients with gastric cancer. To clarify the function of TRIM33 in survival and epithelial-mesenchymal transition in gastric cancer cells, we investigated the effect of TRIM33 knockdown in several gastric cancer cell lines. Downregulation of TRIM33 in BGC-823 and SGC-7901 cells enhanced the proliferation, colony formation, and migratory ability of these gastric cancer cells. It also promoted epithelial-mesenchymal transition; transfection of cells with siRNA targeting TRIM33 led to the upregulation of vimentin and N-Cadherin expression, and downregulation of E-Cadherin expression. Meanwhile, the transforming growth factor beta pathway was activated: levels of transforming growth factor beta were elevated and the expressions of p-Smad2, Smad2, Smad3, and Smad4 were activated. To confirm the role of TRIM33 in vivo, a xenograft model was established in nude mice. Immunohistochemical analysis identified that the protein levels of TRIM33, p-Smad2, Smad2, Smad3, Smad4, vimentin, and N-Cadherin were increased, and E-Cadherin levels were decreased, in xenograft tumors from the si-TRIM33 group. Taken together, these results suggest that TRIM33 may be a potential marker for the diagnosis and prognosis of gastric cancer. Furthermore, it may also serve as a novel target for gastric cancer treatment.

A Novel Plant-Produced Asialo-rhuEPO Protects Brain from Ischemic Damage Without Erythropoietic Action.

Mammalian cell-produced recombinant human erythropoietin (rhuEPOM) has been shown to be a multimodal neuroprotectant targeting an array of key pathological mechanisms in experimental stroke models. However, the rhuEPOM clinical trials were terminated due to increased risk of thrombosis, largely ascribed to its erythropoietic function. We recently took advantage of a plant-based expression system lacking sialylation capacity to produce asialo-rhuEPOP, a rhuEPO derivative without sialic acid residues. In the present study, we proved that asialo-rhuEPOP is non-erythropoietic by repeated intravenous injection (44 µg/kg bw) in mice showing no increase in hemoglobin levels and red blood cell counts, and confirmed that it is non-immunogenic by measuring humoral response after immunizing the mice. We demonstrate that it is neuroprotective in a cerebral ischemia and reperfusion (I/R) mouse model, exhibiting ~ 50% reduction in cerebral infarct volume and edema, and significant improvement in neurological deficits and histopathological outcome. Our studies further revealed that asialo-rhuEPOP, like rhuEPOM, displays pleiotropic neuroprotective effects, including restoring I/R-interrupted mitochondrial fission and fusion proteins, preventing I/R injury-induced increase in mitophagy and autophagy markers, and inhibiting apoptosis to benefit nerve cell survival. Most importantly, asialo-rhuEPOP lacking erythropoietic activity and immunogenicity holds great translational potential as a multimodal neuroprotectant for stroke treatment.

Rethinking the necessity of low glucose intervention for cerebral ischemia/reperfusion injury.

Glucose is the essential and almost exclusive metabolic fuel for the brain. Ischemic stroke caused by a blockage in one or more cerebral arteries quickly leads to a lack of regional cerebral blood supply resulting in severe glucose deprivation with subsequent induction of cellular homeostasis disturbance and eventual neuronal death. To make up ischemia-mediated adenosine 5'-triphosphate depletion, glucose in the ischemic penumbra area rapidly enters anaerobic metabolism to produce glycolytic adenosine 5'-triphosphate for cell survival. It appears that an increase in glucose in the ischemic brain would exert favorable effects. This notion is supported by in vitro studies, but generally denied by most in vivo studies. Clinical studies to manage increased blood glucose levels after stroke also failed to show any benefits or even brought out harmful effects while elevated admission blood glucose concentrations frequently correlated with poor outcomes. Surprisingly, strict glycaemic control in clinical practice also failed to yield any beneficial outcome. These controversial results from glucose management studies during the past three decades remain a challenging question of whether glucose intervention is needed for ischemic stroke care. This review provides a brief overview of the roles of cerebral glucose under normal and ischemic conditions and the results of managing glucose levels in non-diabetic patients. Moreover, the relationship between blood glucose and cerebral glucose during the ischemia/reperfusion processes and the potential benefits of low glucose supplements for non-diabetic patients are discussed.

Neuroprotection by B355252 against Glutamate-Induced Cytotoxicity in Murine Hippocampal HT-22 Cells Is Associated with Activation of ERK3 Signaling Pathway.

Glutamate differentially affects the levels extracellular signal-regulated kinase (ERK)1/2 and ERK3 and the protective effect of B355252, an aryl thiophene compound, 4-chloro-N-(naphthalen-1-ylmethyl)-5-(3-(piperazin-1-yl)phenoxy)thiophene-2-sulfonamide, is associated with suppression of ERK1/2. The objectives of this study were to further investigate the impact of B355252 on ERK3 and its downstream signaling pathways affected by glutamate exposure in the mouse hippocampal HT-22 neuronal cells. Murine hippocampal HT22 cells were incubated with glutamate and treated with B355252. Cell viability was assessed, protein levels of pERK3, ERK3, mitogen-activated protein kinase-activated protein kinase-5 (MAPKAPK-5), steroid receptor coactivator 3 (SRC-3), p-S6 and S6 were measured using Western blotting, and immunoreactivity of p-S6 was determined by immunocytochemistry. The results reveal that glutamate markedly diminished the protein levels of p-ERK3 and its downstream targets MK-5 and SRC-3 and increased p-S6, an indicator for mechanistic target of rapamycin (mTOR) activation. Conversely, treatment with B355252 protected the cells from glutamate-induced damage and prevented the glutamate-caused declines of p-ERK3, MK-5 and SRC-3 and increase of p-S6. Our study demonstrates that one of the mechanisms that glutamate mediates its cytotoxicity is through suppression of ERK3 and that B355252 rescues the cells from glutamate toxicity by reverting ERK3 level.

Ubisol Coenzyme Q10 promotes mitochondrial biogenesis in HT22 cells challenged by glutamate.

Glutamate-induced excitotoxicity is a well-recognized cause of neuronal cell death. Nutritional supplementation with Coenzyme Q10 (CoQ10) has been previously demonstrated to serve neuro-protective effects against glutamate-induced excitotoxicity. The aim of the present study was to determine whether the protective effect of CoQ10 against glutamate toxicity could be attributed to stimulating mitochondrial biogenesis. Mouse hippocampal neuronal HT22 cells were incubated with glutamate with or without ubisol Q10. The results revealed that glutamate significantly decreased levels of mitochondrial biogenesis related proteins, including peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α and nuclear respiratory factor (NRF)2. Additionally, glutamate reduced mitochondrial biogenesis, as determined using a mitochondrial biogenesis kit. Pretreatment with CoQ10 prevented decreases in phosphorylated (p)-Akt, p-cAMP response element-binding protein, PGC-1α, NRF2 and mitochondrial transcription factor A, increasing mitochondrial biogenesis. Taken together, the results described a novel mechanism of CoQ10-induced neuroprotection and indicated a central role for mitochondrial biogenesis in protecting against glutamate-induced excitotoxicity.

MicroRNA-205-5p inhibits skin cancer cell proliferation and increase drug sensitivity by targeting TNFAIP8.

Tumor necrosis factor-α-induced protein 8 (TNFAIP8) is a member of the TIPE/TNFAIP8 family which regulates tumor growth and survival. Our goal is to delineate the detailed oncogenic role of TNFAIP8 in skin cancer development and progression. Here we demonstrated that higher expression of TNFAIP8 is associated with basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma development in patient tissues. Induction of TNFAIP8 expression by TNFα or by ectopic expression of TNFAIP8 in SCC or melanoma cell lines resulted in increased cell growth/proliferation. Conversely, silencing of TNFAIP8 decreased cell survival/cell migration in skin cancer cells. We also showed that miR-205-5p targets the 3'UTR of TNFAIP8 and inhibits TNFAIP8 expression. Moreover, miR-205-5p downregulates TNFAIP8 mediated cellular autophagy, increased sensitivity towards the B-RAFV600E mutant kinase inhibitor vemurafenib, and induced cell apoptosis in melanoma cells. Collectively our data indicate that miR-205-5p acts as a tumor suppressor in skin cancer by targeting TNFAIP8.

Phenoxythiophene sulfonamide compound B355252 protects neuronal cells against glutamate-induced excitotoxicity by attenuating mitochondrial fission and the nuclear translocation of AIF.

Glutamate neurotoxicity has been implicated in the initiation and progression of various neurological and neurodegenerative disorders. Therefore, it is necessary to develop therapeutics for the treatment of patients with these devastating diseases. Mitochondrial fission plays an import role in the mediation of cell death and survival. The objective of the present study was to determine whether B355252, a phenoxythiophene sulfonamide derivative, reduces glutamate-induced cell death by inhibiting mitochondrial fission and the nuclear translocation of apoptosis-inducing factor (AIF) in glutamate-challenged HT22 neuronal cells. The results revealed that glutamate treatment led to large increases in the mitochondrial levels of the major fission proteins dynamin-related protein 1 (Drp1) and mitochondrial fission 1 protein (Fis1), but only small elevations in the fusion proteins mitofusin 1 and 2 (Mfn1/2) and optic atrophy 1 (Opa1). In addition, glutamate toxicity disrupted mitochondrial reticular networks and increased the translocation of AIF to the nucleus. Pretreatment with B35525 reduced glutamate-induced cell death and prevented the increases in the protein levels of Drp1, Fis1, Mfn1/2 and Opa1 in the mitochondrial fraction. More importantly, the architecture of the mitochondria was protected and nuclear translocation of AIF was completely inhibited by B35525. These findings suggest that the regulation of mitochondrial dynamics is central to the neuroprotective properties of B355252, and presents an attractive opportunity for potential development as a therapy for neurodegenerative disorders associated with mitochondria dysfunction.

Mitochondrial dysfunction contributes to Rapamycin-induced apoptosis of Human Glioblastoma Cells - A synergistic effect with Temozolomide.

Mammalian target of rapamycin (mTOR) is upregulated in a high percentage of glioblastomas. While a well-known mTOR inhibitor, rapamycin, has been shown to reduce glioblastoma survival, the role of mitochondria in achieving this therapeutic effect is less well known. Here, we examined mitochondrial dysfunction mechanisms that occur with the suppression of mTOR signaling. We found that, along with increased apoptosis, and a reduction in transformative potential, rapamycin treatment significantly affected mitochondrial health. Specifically, increased production of reactive oxygen species (ROS), depolarization of the mitochondrial membrane potential (MMP), and altered mitochondrial dynamics were observed. Furthermore, we verified the therapeutic potential of rapamycin-induced mitochondrial dysfunction through co-treatment with temzolomide (TMZ), the current standard of care for glioblastoma. Together these results demonstrate that the mitochondria remain a promising target for therapeutic intervention against human glioblastoma and that TMZ and rapamycin have a synergistic effect in suppressing glioblastoma viability, enhancing ROS production, and depolarizing MMP.

Deletion of mitochondrial uncoupling protein 2 exacerbates mitophagy and cell apoptosis after cerebral ischemia and reperfusion injury in mice.

Objective: Uncoupling protein 2 (UCP2) is a member of inner mitochondrial membrane proteins and deletion of UCP2 exacerbates brain damage after cerebral ischemia/reperfusion (I/R). Nevertheless, its functional role during cerebral I/R is not entirely understood. The objective of present study was to explore the influence of UCP2 deletion on mitochondrial autophagy (mitophagy) and mitochondria-mediated cell death pathway after cerebral I/R. Methods: UCP2-/- and wildtype (WT) mice were subjected to 60 min middle cerebral artery occlusion (MCAO) and allowed reperfusion for 24 hours. Infarct volume and histological outcomes were assessed, reactive oxygen species (ROS) and autophagy markers were measured, and mitochondrial ultrastructure was examined. Results: Deletion of UCP2 enlarged infarct volume, increased numbers of necrotic and TUNEL positive cells, and significantly increased pro-apoptotic protein levels in UCP2-/- mice compared with WT mice subjected to the same duration of I/R. Further, deletion of UCP2 increased ROS production, elevated LC3, Beclin1 and PINK1, while it suppressed p62 compared with respective WT ischemic controls. Electron microscopic study demonstrated the number of autophagosomes was higher in the UCP2-/- group, compared with the WT group. Conclusions: It is concluded that deletion of UCP2 exacerbates cerebral I/R injury via reinforcing mitophagy and cellular apoptosis in mice.

Ameliorative Effect of Sodium Selenite on Silver Nanoparticles-Induced Myocardiocyte Structural Alterations in Rats.

BACKGROUND: The application of silver nanoparticles (AgNPs) is growing exponentially, and its potential damage to the cardiac remains to be elucidated. The purpose of this study was to investigate the ameliorative effect of sodium selenite on silver nanoparticles-induced myocardiocyte structural alterations in rats. MATERIALS AND METHODS: Forty male Sprague-Dawley (SD) rats were randomly divided into four groups: control group, AgNPs group, Se control group, and AgNPs + Se group. SD rats were administered AgNPs through a single intratracheal instillation, and sodium selenite was given by intraperitoneal injection for seven days. Cardiac function was determined by echocardiography and hemodynamic, ultrastructural changes by transmission electron microscopy examination. Mitochondrial fission and autophagy markers were measured by Western blotting. RESULTS: AgNPs caused a significant decrease in cardiac contraction, diastolic dysfunction, fragmentation, and lysis of the myofibrils, the formation of stenosis in the capillary, damaging the mitochondria membrane and cristae. AgNPs significantly increased mitochondrial fission markers dynamin-related protein 1 (Drp1), phospho-Drp1 (p-Drp1), and mitochondrial fission protein 1 (Fis1), as well as autophagy marker LC3 II/I (P<0.05). Treatment with sodium selenite is capable of protecting cardiac function from AgNPs toxicity through attenuating ultrastructural alterations, stabilizing mitochondrial dynamic balance and blocking mitochondrial autophagy. CONCLUSION: We conclude that the protection of sodium selenite against silver nanoparticles-induced myocardiocyte structural alterations is associated with stabilizing mitochondrial dynamic balance and mitophagy.

Suppression of NLRP3 Inflammasome, Pyroptosis, and Cell Death by NIM811 in Rotenone-Exposed Cells as an in vitro Model of Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) is characterized by the selective death of dopaminergic neurons in the substantia nigra. Recently, NLRP3 inflammasome and pyroptosis were found to be associated with PD. Cyclosporine A (CsA), an immunosuppressant, reduces neuronal death in PD. However, CsA could hardly pass through the blood-brain barrier (BBB) and high dose is associated with severe side effects and toxicity. N-methyl-4-isoleucine-cyclosporine (NIM811) is a CsA derivate that can pass through the BBB. However, little is known about its effect on PD. OBJECTIVE: The objectives of this study were to explore the mechanism of rotenone-induced cell damage and to examine the protective effects of NIM811 on the neurotoxicity of a Parkinson-like in vitro model induced by rotenone. METHODS: Murine hippocampal HT22 cells were cultured with the mitochondrial complex I inhibitor rotenone, a widely used pesticide that has been used for many years as a tool to induce a PD model in vitro and in vivo and proven to be reproducible. NIM811 was added to the culture media 3 h prior to the rotenone incubation. Cell viability was determined by resazurin assay, reactive oxygen species (ROS) production by dihydroethidine (DHE), and mitochondrial membrane potential by tetramethyl rhodamine methyl ester (TMRM). TUNEL and caspase-1 immunofluorescent double staining was used to detect pyroptosis. NLRP3, caspase-1, pro-caspase-1, GSDMD, and interleukin-18 (IL-18) were measured using Western blotting after 24 h of rotenone incubation. The reactivity of interleukin-1ß (IL-1ß) was determined by ELISA. RESULTS: Our results demonstrated that rotenone caused more than 40% of cell death, increased ROS production, and reduced mitochondrial membrane potential, while NIM811 reversed these alterations. Immunofluorescent double staining showed that rotenone increased the percentage of caspase-1 and TUNEL double-labelled cells, an indication of pyroptosis, after 24 h of incubation. The protein expression of NLRP3, caspase-1, pro-caspase-1, GSDMD, IL-18, and IL-1ß was significantly increased after 24 h of rotenone incubation. NIM811 suppressed rotenone-induced pyroptosis and downregulated the protein expression of NLRP3, caspase-1, pro-caspase-1, GSDMD, IL-1ß, and IL-18. CONCLUSION: These results provide evidence that rotenone activates the NLRP3 inflammomere and induces pyroptosis. NIM811 protects the cell from rotenone-induced damage and inhibits NLRP3 inflammasome and pyroptosis. NIM811 might serve as a potential therapeutic drug in the treatment of PD.

Quantitative Proteomics Reveals the Beneficial Effects of Low Glucose on Neuronal Cell Survival in an in vitro Ischemic Penumbral Model.

Understanding proteomic changes in the ischemic penumbra are crucial to rescue those salvageable cells and reduce the damage of an ischemic stroke. Since the penumbra region is dynamic with heterogeneous cells/tissues, tissue sampling from animal models of stroke for the molecular study is a challenge. In this study, cultured hippocampal HT22 cells under hypoxia treatment for 17.5 h with 0.69 mM low glucose (H+LG) could mimic ischemic penumbral cells since they had much higher cell viability and viable cell number compared to hypoxia without glucose (H-G) treatment. To validate established cell-based ischemic penumbral model and understand the beneficial effects of low glucose (LG), quantitative proteomics analysis was performed on H+LG, H-G, and normoxia with normal 22 mM glucose (N+G) treated cells. We identified 427 differentially abundant proteins (DAPs) between H-G and N+G and further identified 105 DAPs between H+LG and H-G. Analysis of 105 DAPs revealed that LG promotes cell survival by activating HIF1α to enhance glycolysis; preventing the dysregulations of extracellular matrix remodeling, cell cycle and division, and antioxidant and detoxification; as well as attenuating inflammatory reaction response, protein synthesis and neurotransmission activity. Our results demonstrated that this established cell-based system could mimic penumbral conditions and can be used for molecular studies.

Deletion of Mitochondrial Uncoupling Protein 2 Exacerbates Mitochondrial Damage in Mice Subjected to Cerebral Ischemia and Reperfusion Injury under both Normo- and Hyperglycemic Conditions.

Deletion of mitochondrial uncoupling protein 2 (UCP2) has been shown to aggravate ischemic damage in the brain. However, the underlying mechanisms are not fully understood. The objective of this study is to explore the impact of homozygous UCP2 deletion (UCP2-/-) on mitochondrial fission and fusion dynamic balance in ischemic mice under normo- and hyperglycemic conditions. UCP2-/- and wildtype mice were subjected to a 60 min middle cerebral artery occlusion (MCAO) and allowed reperfusion for 6h, 24h and 72h. Our results demonstrated that deletion of UCP2 enlarged infarct volumes and increased numbers of cell death in both normo- and hyperglycemic ischemic mice compared with their wildtype counterparts subjected to the same duration of ischemia and reperfusion. The detrimental effects of UCP deletion were associated with increased ROS production, elevated mitochondrial fission markers Drp1 and Fis1 and suppressed fusion markers Opa1 and Mfn2 in UCP2-/- mice. Electron microscopic study demonstrated a marked mitochondrial swolling after 6h of reperfusion in UCP2-/- mice, contrasting to a mild mitochondrial swolling in wildtype ischemic animals. It is concluded that the exacerbating effects of UCP2-/- on ischemic outcome in both normo- and hyperglycemic animals are associated with increased ROS production, disturbed mitochondrial dynamic balance towards fission and early damage to mitochondrial ultrastructure.

The Immp2l Mutation Causes Ovarian Aging Through ROS-Wnt/ß-Catenin-Estrogen Pathway: Preventive Effect of Melatonin.

Mitochondria play important roles in ovarian follicle development. Mitochondrial dysfunction, including mitochondrial gene deficiency, impairs ovarian development. Here, we explored the role and mechanism of mitochondrial inner membrane gene Immp2l in ovarian follicle growth and development. Our results revealed that female Immp2l-/- mice were infertile, whereas Immp2l+/- mice were normal. Body and ovarian weights were reduced in the female Immp2l-/- mice, ovarian follicle growth and development were stunted in the secondary follicle stage. Although a few ovarian follicles were ovulated, the oocytes were not fertilized because of mitochondrial dysfunction. Increased oxidative stress, decreased estrogen levels, and altered genes expression of Wnt/ß-catenin and steroid hormone synthesis pathways were observed in 28-day-old Immp2l-/- mice. The Immp2l mutation accelerated ovarian aging process, as no ovarian follicles were detected by age 5 months in Immp2l-/- mice. All the aforementioned changes in the Immp2l-/- mice were reversed by administration of antioxidant melatonin to the Immp2l-/- mice. Furthermore, our in vitro study using Immp2l knockdown granulosa cells confirmed that the Immp2l downregulation induced granulosa cell aging by enhancing reactive oxygen species (ROS) levels, suppressing Wnt16, increasing ß-catenin, and decreasing steroid hormone synthesis gene cyp19a1 and estrogen levels, accompanied by an increase in the aging phenotype of granulosa cells. Melatonin treatment delayed granulosa cell aging progression. Taken together, Immp2l causes ovarian aging through the ROS-Wnt/ß-catenin-estrogen (cyp19a1) pathway, which can be reversed by melatonin treatment.