GARNL3 identified as a crucial target for overcoming temozolomide resistance in EGFRvIII-positive glioblastoma.

OBJECT: Amplification of the epidermal growth factor receptor (EGFR) and its active mutant type III (EGFRvIII), frequently occurr in glioblastoma (GBM), contributing to chemotherapy and radiation resistance in GBM. Elucidating the underlying molecular mechanism of temozolomide (TMZ) resistance in EGFRvIII GBM could offer valuable insights for cancer treatment. METHODS: To elucidate the molecular mechanisms underlying EGFRvIII-mediated resistance to TMZ in GBM, we conducted a comprehensive analysis using Gene Expression Omnibus and The cancer genome atlas (TCGA) databases. Initially, we identified common significantly differentially expressed genes (DEGs) and prioritized those correlating significantly with patient prognosis as potential downstream targets of EGFRvIII and candidates for drug resistance. Additionally, we analyzed transcription factor expression changes and their correlation with candidate genes to elucidate transcriptional regulatory mechanisms. Using estimate method and databases such as Tumor IMmune Estimation Resource (TIMER) and CellMarker, we assessed immune cell infiltration in TMZ-resistant GBM and its relationship with candidate gene expression. In this study, we examined the expression differences of candidate genes in GBM cell lines following EGFRvIII intervention and in TMZ-resistant GBM cell lines. This preliminary investigation aimed to verify the regulatory impact of EGFRvIII on candidate targets and its potential involvement in TMZ resistance in GBM. RESULTS: Notably, GTPase Activating Rap/RanGAP Domain Like 3 (GARNL3) emerged as a key DEG associated with TMZ resistance and poor prognosis, with reduced expression correlating with altered immune cell profiles. Transcription factor analysis suggested Epiregulin (EREG) as a putative upstream regulator of GARNL3, linking it to EGFRvIII-mediated TMZ resistance. In vitro experiments confirmed EGFRvIII-mediated downregulation of GARNL3 and decreased TMZ sensitivity in GBM cell lines, further supported by reduced GARNL3 levels in TMZ-resistant GBM cells. CONCLUSION: GARNL3 downregulation in EGFRvIII-positive and TMZ-resistant GBM implicates its role in TMZ resistance, suggesting modulation of EREG/GARNL3 signaling as a potential therapeutic strategy.

Exploring non-coding RNA mechanisms in hepatocellular carcinoma: implications for therapy and prognosis.

Hepatocellular carcinoma (HCC) is a significant contributor to cancer-related deaths in the world. The development and progression of HCC are closely correlated with the abnormal regulation of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Important biological pathways in cancer biology, such as cell proliferation, death, and metastasis, are impacted by these ncRNAs, which modulate gene expression. The abnormal expression of non-coding RNAs in HCC raises the possibility that they could be applied as new biomarkers for diagnosis, prognosis, and treatment targets. Furthermore, by controlling the expression of cancer-related genes, miRNAs can function as either tumor suppressors or oncogenes. On the other hand, lncRNAs play a role in the advancement of cancer by interacting with other molecules within the cell, which, in turn, affects processes such as chromatin remodeling, transcription, and post-transcriptional processes. The importance of ncRNA-driven regulatory systems in HCC is being highlighted by current research, which sheds light on tumor behavior and therapy response. This research highlights the great potential of ncRNAs to improve patient outcomes in this difficult disease landscape by augmenting the present methods of HCC care through the use of precision medicine approaches.

The MT1 receptor as the target of ramelteon neuroprotection in ischemic stroke.

Stroke is the leading cause of death and disability worldwide. Novel and effective therapies for ischemic stroke are urgently needed. Here, we report that melatonin receptor 1A (MT1) agonist ramelteon is a neuroprotective drug candidate as demonstrated by comprehensive experimental models of ischemic stroke, including a middle cerebral artery occlusion (MCAO) mouse model of cerebral ischemia in vivo, organotypic hippocampal slice cultures ex vivo, and cultured neurons in vitro; the neuroprotective effects of ramelteon are diminished in MT1-knockout (KO) mice and MT1-KO cultured neurons. For the first time, we report that the MT1 receptor is significantly depleted in the brain of MCAO mice, and ramelteon treatment significantly recovers the brain MT1 losses in MCAO mice, which is further explained by the Connectivity Map L1000 bioinformatic analysis that shows gene-expression signatures of MCAO mice are negatively connected to melatonin receptor agonist like Ramelteon. We demonstrate that ramelteon improves the cerebral blood flow signals in ischemic stroke that is potentially mediated, at least, partly by mechanisms of activating endothelial nitric oxide synthase. Our results also show that the neuroprotection of ramelteon counteracts reactive oxygen species-induced oxidative stress and activates the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway. Ramelteon inhibits the mitochondrial and autophagic death pathways in MCAO mice and cultured neurons, consistent with gene set enrichment analysis from a bioinformatics perspective angle. Our data suggest that Ramelteon is a potential neuroprotective drug candidate, and MT1 is the neuroprotective target for ischemic stroke, which provides new insights into stroke therapy. MT1-KO mice and cultured neurons may provide animal and cellular models of accelerated ischemic damage and neuronal cell death.

FBLIM1 mRNA is a novel prognostic biomarker and is associated with immune infiltrates in glioma.

Glioma is the most common primary brain tumor. Filamin-binding LIM protein 1 (FBLIM1) has been identified in multiple cancers and is suspected of playing a part in the development of tumors. However, the potential function of FBLIM1 mRNA in glioma has not been investigated. In this study, the clinical information and transcriptome data of glioma patients were, respectively, retrieved from the TCGA and CGGA databases. The expression level of FBLIM1 mRNA was shown to be aberrant in a wide variety of malignancies. Significantly, when glioma samples were compared to normal brain samples, FBLIM1 expression was shown to be significantly elevated in the former. A poor prognosis was related to high FBLIM1 expression, which was linked to more advanced clinical stages. Notably, multivariate analyses demonstrated that FBLIM1 expression was an independent predictor for the overall survival of glioma patients. Immune infiltration analysis disclosed that FBLIM1 expression had relevance with many immune cells. The results of RT-PCR suggested that FBLIM1 expression was markedly elevated in glioma specimens. Functional experiments unveiled that the knockdown of FBLIM1 mRNA suppressed glioma cell proliferation. In general, we initially discovered that FBLIM1 mRNA might be a possible prognostic marker in glioma.

Progress in building clinically relevant patient-derived tumor xenograft models for cancer research.

Patient-derived tumor xenograft (PDX) models, a method involving the surgical extraction of tumor tissues from cancer patients and subsequent transplantation into immunodeficient mice, have emerged as a pivotal approach in translational research, particularly in advancing precision medicine. As the first stage of PDX development, the patient-derived orthotopic xenograft (PDOX) models implant tumor tissue in mice in the corresponding anatomical locations of the patient. The PDOX models have several advantages, including high fidelity to the original tumor, heightened drug sensitivity, and an elevated rate of successful transplantation. However, the PDOX models present significant challenges, requiring advanced surgical techniques and resource-intensive imaging technologies, which limit its application. And then, the humanized mouse models, as well as the zebrafish models, were developed. Humanized mouse models contain a human immune environment resembling the tumor and immune system interplay. The humanized mouse models are a hot topic in PDX model research. Regarding zebrafish patient-derived tumor xenografts (zPDX) and patient-derived organoids (PDO) as promising models for studying cancer and drug discovery, zPDX models are used to transplant tumors into zebrafish as novel personalized medical animal models with the advantage of reducing patient waiting time. PDO models provide a cost-effective approach for drug testing that replicates the in vivo environment and preserves important tumor-related information for patients. The present review highlights the functional characteristics of each new phase of PDX and provides insights into the challenges and prospective developments in this rapidly evolving field.

The application of Aptamer in biomarker discovery.

Biomarkers are detectable molecules that can reflect specific physiological states of cells, organs, and organisms and therefore be regarded as indicators for specific diseases. And the discovery of biomarkers plays an essential role in cancer management from the initial diagnosis to the final treatment regime. Practically, reliable clinical biomarkers are still limited, restricted by the suboptimal methods in biomarker discovery. Nucleic acid aptamers nowadays could be used as a powerful tool in the discovery of protein biomarkers. Nucleic acid aptamers are single-strand oligonucleotides that can specifically bind to various targets with high affinity. As artificial ssDNA or RNA, aptamers possess unique advantages compared to conventional antibodies. They can be flexible in design, low immunogenicity, relative chemical/thermos stability, as well as modifying convenience. Several SELEX (Systematic Evolution of Ligands by Exponential Enrichment) based methods have been generated recently to construct aptamers for discovering new biomarkers in different cell locations. Secretome SELEX-based aptamers selection can facilitate the identification of secreted protein biomarkers. The aptamers developed by cell-SELEX can be used to unveil those biomarkers presented on the cell surface. The aptamers from tissue-SELEX could target intracellular biomarkers. And as a multiplexed protein biomarker detection technology, aptamer-based SOMAScan can analyze thousands of proteins in a single run. In this review, we will introduce the principle and workflow of variations of SELEX-based methods, including secretome SELEX, ADAPT, Cell-SELEX and tissue SELEX. Another powerful proteome analyzing tool, SOMAScan, will also be covered. In the second half of this review, how these methods accelerate biomarker discovery in various diseases, including cardiovascular diseases, cancer and neurodegenerative diseases, will be discussed.

Up-regulation of VSIG4 alleviates kidney transplantation-associated acute kidney injury through suppressing inflammation and ROS via regulation of AKT signaling.

Prolonged cold ischemia (CI) is a risk factor for acute kidney injury (AKI) after kidney transplantation (KT). AKI is an abrupt and rapid reduction in renal function due to multi-factors, including inflammation, oxidative stress and apoptosis. V-set immunoglobulin-domain-containing 4 (VSIG4) is a B7 family-related protein and specifically expressed in resting tissue-resident macrophages to mediate various cellular events. In the study, we attempted to explore the effects of VSIG4 on CI/KT-induced AKI in a mouse model. Our results showed that VSIG4 expression was markedly down-regulated in serum of kidney transplant recipients with acute rejection, and in renal tissues of cold ischemia-reperfusion (IR)-operated mice with AKI, which was confirmed in murine macrophages stimulated by oxygen glucose deprivation/reoxygenation (OGD/R). We then found that exogenous VSIG4 markedly ameliorated histological changes in kidney of CI/KT mice by suppressing inflammation and apoptosis through restraining nuclear factor-κB (NF-κB) and Caspase-3 activation, respectively. Oxidative stress and reactive oxygen species (ROS) accumulation in renal tissues were also mitigated by exogenous VSIG4 in CI/KT mice through improving nuclear factor-erythroid 2 related factor 2 (Nrf2) nuclear expression. The inhibitory effects of VSIG4 on inflammation, ROS generation and cell death were confirmed in OGD/R-treated macrophages, which further ameliorated oxidative damage and apoptosis in podocytes. More in vivo and in vitro studies showed that CI/KT- and OGD/R-induced AKI was further accelerated by VSIG4 knockdown. Mechanistically, VSIG4 directly interacted with AKT, and AKT activation was necessary for VSIG4 to govern all these above mentioned cellular processes. Collectively, our findings demonstrated that VSIG4 could mitigate AKI in a CI/KT mouse model, and we identified VSIG4/AKT axis as a promising therapeutic target for the treatment of the disease.

Organoids: A Platform Ready for Glioblastoma Precision Medicine?

Patient-derived organoids can recapitulate parental tumor heterogeneity. In a recent study in Cell, Jacob et al. cultivated glioblastoma organoids (GBOs) to mimic tumor heterogeneity and chimeric antigen receptor (CAR)-T cell immunotherapy, applied it for xenograft establishment and drug testing, and generated a biobank for the timely start of post-operation therapy.

Tartary buckwheat extract alleviates alcohol-induced acute and chronic liver injuries through the inhibition of oxidative stress and mitochondrial cell death pathway.

Alcohol use disorder (AUD) is an enormous public health problem that poses significant social, medical, and economic burdens. Under AUD, the liver is one of the most adversely affected organs. As current therapies and protective drugs for AUD-mediated liver injury are very limited, the prevention and therapy of alcoholic liver disease are urgently needed. The present study aims to investigate the beneficial effects of tartary buckwheat extract (TBE), the important component of Maopu tartary buckwheat liquor, on both alcoholic-induced acute and chronic liver injuries. We show that the TBE administration, similar to curcumin, significantly reduces the elevated serum aspartate aminotransferase and alanine aminotransferase levels, improves liver index, alleviates the elevated contents of hepatic malondialdehye, and restores the decreased contents of hepatic glutathione both in acute and chronic liver injuries in alcohol-exposed rats. Furthermore, histopathological analyses show that a medium dose of TBE (16.70 ml/kg body weight) alleviates hepatocyte morphology changes in both acute and chronic alcohol exposure models. We also show the protective effects of TBE on the cell death rates of alcohol-exposed primary cultured hepatocytes, HepG2 hepatoma, and Huh 7 hepatoma cells. Furthermore, we demonstrate that TBE exerts hepatoprotection partly through inhibiting the mitochondrial cell death pathway by reducing cytochrome c release, caspase-9 and -3 activities, and the number of TUNEL-positive cells. These effects of TBE were accompanied by enhanced levels of Bcl-2 and Bcl-xL and autophagic cell death pathway by reducing Beclin-1 expression, as well as through promoting its anti-oxidant capacity by suppressing reactive oxygen species production. This study demonstrates, for the first time, the protective effect of TBE against alcohol-induced acute and chronic liver injury in vivo and in vitro. Given the dietary nature of tartary buckwheat, pueraria, lycium barbarum, and hawthorn, the oral intake of TBE or liquor contained TBE, e.g., Maopu Tartary buckwheat liquor, compared with pure liquor consumption alone, may have the potential to alleviate alcoholic-induced liver injuries.

TGF-ß Signaling Promotes Glioma Progression Through Stabilizing Sox9.

Gliomas are brain and spinal cord malignancies characterized by high malignancy, high recurrence and poor prognosis, the underlying mechanisms of which remain largely elusive. Here, we found that the Sry-related high mobility group box (Sox) family transcription factor, Sox9, was upregulated and correlated with poor prognosis of clinical gliomas. Sox9 promotes migration and invasion of glioma cells and in vivo development of xenograft tumors from inoculated glioma cells. Sox9 functions downstream of the transforming growth factor-ß (TGF-ß) pathway, in which TGF-ß signaling prevent proteasomal degradation of the Sox9 protein in glioma cells. These findings provide novel insight into the wide interplay between TGF-ß signaling and oncogenic transcription factors, and have implications for targeted therapy and prognostic assessment of gliomas.

CADM2 inhibits human glioma proliferation, migration and invasion.

Malignant glioma is one of the most common malignant tumors in the brain parenchyma with a poor prognosis. Cell adhesion molecules (CADMs) immunoglobulin super family is involved in the maintenance of cell adhesion, polarity and tumor suppression. However, the role and mechanisms of CADM2 in human glioma have yet to be elucidated. Therefore, the present study evaluated the expression level of CADM2 and demonstrated that CADM2 was markedly downregulated in human glioma tissues compared with normal brain tissue and glioma cell lines, and the CADM2 expression level was significantly decreased in high­grade glioma tissues. Overexpression of CADM2 inhibited the proliferation of glioma cell proliferation in vitro and in vivo. CADM2 also inhibited the migration and invasion of U87 and U251 cells. Furthermore, overexpression of CADM2 induced a significant decrease in the expression of G1/S transition key regulators, cyclin D1, cyclin E, cyclin­dependent kinase (CDK)2 and CDK4. Additionally, CADM2 expression was associated with alterations in epithelial­mesenchymal transition (EMT) markers, including E­cadherin and ß­catenin. Taken together, the results of the present study demonstrated that CADM2 inhibits glioma tumorigenesis by regulating the cell cycle and the EMT process, suggesting that CADM2 may be a novel potential therapeutic target in human glioma.

Amelioration of prediabetes-induced changes of dendritic structural plasticity.

Accumulating evidence suggests that the diabetes-induced cognitive dysfunction can be alleviated when exposed to the enriched environment. However, the impact of the changes of the hippocampal plasticity on the cognitive decline and the possible effect of an enriched environment in prediabetes are still not clearly documented. To explore the effect of enriched environment for prediabetes-induced changes of dendritic structural plasticity in hippocampus pyramidal and cognitive deficits, the praxiology experiments for evaluating of anxiety, spatial learning and memory of prediabetic Wistar were performed, and then the dendritic spine density was assessed in the hippocampal CA1 pyramidal neuronal region. The prediabetic rats demonstrated a hyper-anxiety like behavior and significantly decreased spatial learning abilities and memory deficits. Exposing prediabetic rats to an enriched environment appeared to significantly mitigate the above changes in a time-dependent manner. The enriched environment also restored the density of the hippocampal dendritic spine which was significantly reduced in prediabetic rats. We found that the enriched environment was beneficial in overcoming the prediabetes-induced cognitive disorders and diminished dendritic plasticity of hippocampus pyramidal.

TGF-beta/TGF-beta RII/CLC-3 axis promotes cognitive disorders in diabetes.

Transforming growth factor beta (TGF-beta) and Chloride channel-3 (CLC-3) are critical for inflammatory response, cellular proliferation and apoptosis in hippocampus neurons. However, the relationship between CLC-3 and TGF-beta/TGF-beta Receptor II (RII) pathway in diabetic encephalopathy (DE) is unknown. In this study, both diabetes rat model and diabetes cell model were employed to elucidate the mechanisms involved. The increased expressions of CLC-3 and TGF- beta RII with cognitive impairment were observed in diabetic rats. The most obvious reduction on the survival of HT22 cells was at 10 ng/ml or 15 ng/ml TGF- beta stimulation, while the expressions of CLC-3 and TGF-beta RII were significantly increased under high glucose condition. Moreover, the study showed that CLC-3 antagonists had no apparent effect on up-regulated TGF- beta RII, but TGF- beta 1 inhibitors could reduce the up-regulated CLC-3 under high glucose. Results from the present study indicated that CLC-3 and TGF- beta signals might be related to cognitive disorders. The CLC-3 might be modulated by TGF- beta /TGF- beta RII signaling pathway during the development of DE.

Gene expression profile analysis of U251 glioma cells with shRNA-mediated SOX9 knockdown.

PURPOSE: In glioma, the sex-determining region Y-box 9 gene (SOX9) is overexpressed and its downregulation leads to inhibition of cell proliferation, invasion and increased cell apoptosis. To further evaluate the molecular and signal pathways associated with the function of SOX9 and SOX9 target genes, a global gene expression profile of the established SOX9-knockdown U251 cells was investigated. METHODS: The molecular function and biological pathways of differentially expressed genes (DEGs) were identified by gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The interactome networks of DEGs were constructed using the STRING online tool. The genes were further validated by RT-qPCR. RESULTS: GO analysis revealed that a set of 194 DEGs was shared in both the SOX9 KD-1 and SOX9 KD-2 U251 cells. GO analysis and KEGG pathway analysis showed that the DEGs were associated with biological processes involving cellular responses to hypoxia, osteoblast differentiation and angiogenesis, and special biological pathways, such as a TGF-beta signaling pathway and a HIF-1 signaling pathway. In addition, computational network of novel identified potential target genes linked to SOX9, including TGFB2, VEGFA, EGLN3 (PHD3), CA9 and HIF-1a. All of these genes were downregulated in the SOX9 knockdown U251 cells. CONCLUSIONS: SOX9 may be a key regulator impacting the glioma cellular processes by influencing the cellular response to hypoxia and HIF-1 signaling pathway. TGFB2, VEGFA, EGLN3 (PHD3), CA9, and HIF-1a may be the target genes of SOX9.

Association between SOX9 and CA9 in glioma, and its effects on chemosensitivity to TMZ.

Temozolomide (TMZ) is a standard chemotherapeutic drug used in the treatment of glioblastoma multiforme (GBM); however, resistance to this drug is common. SRY-Box 9 (SOX9) expression is associated with a poor prognosis of patients with GBM and with resistance to TMZ. Therefore, the aim of this study was to examine the effects of SOX9 inhibition on the sensitivity of glioma cells to TMZ treatment. We knocked down the expression of SOX9 (SOX9KD) via lentiviral infection in two glioblastoma (U87 and U251) cell lines, and the cells were then subjected to gene microarray, Gene Ontology and KEGG analysis pathway, all of which revealed a close association between SOX9 and the carbonic anhydrase 9 (CA9) gene. The TMZ-mediated apoptosis of glioma cells was significantly increased in the cells in the SOX9KD group. The potential underlying mechanism involved the downregulation of SOX9 and CA9 expression, which in turn decreased Akt phosphorylation, downregulated BCL­2 expression, and upregulated BAX expression, as assessed by western blot analysis and RT-qPCR. The effects were found to be substantially enhanced in the cells in the SOX9KD group treated with TMZ. Subsequently, considering the association between SOX9 and CA9, the effects of CA9 inhibition, using a CA9 inhibitor (U­104), on the chemosensitivity of glioma cells to TMZ were assessed. The results revealed that the use of U­104 + TMZ effectively induced glioma cell death, compared to treatment with TMZ alone. The underlying mechanisms were similar to those observed with the silencing of SOX9 in the TMZ-treated glioma cells. On the whole, the findings of this study establish the SOX9/CA9-mediated oncogenic pathway in glioma, the inhibition of which enhances the sensitivity of glioma cells to TMZ treatment, and thus highlights the value of developing small molecules or antibodies against the SOX9/CA9 pathway, for combination therapy with TMZ, in the more efficient management of glioma.

SOX9-PDK1 axis is essential for glioma stem cell self-renewal and temozolomide resistance.

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor with limited therapeutic options. Glioma stem cell (GSC) is thought to be greatly responsible for glioma tumor progression and drug resistance. But the molecular mechanisms of GSC deriving recurrence and drug resistance are still unclear. SOX9 (sex-determining region Y (SRY)-box9 protein), a transcription factor expressed in most solid tumors, is reported as a key regulator involved in maintaining cancer hallmarks including the GSCs state. Previously, we have observed that silencing of SOX9 suppressed glioma cells proliferation both in vitro and in vivo. Here, we found that SOX9 was essential for GSC self-renewal. Silencing of SOX9 down-regulated a broad range of stem cell markers and inhibited glioma cell colony and sphere formation. We identified pyruvate dehydrogenase kinase 1 (PDK1) as a target gene of SOX9 using microarray analyses. PDK1 inactivation greatly inhibited glioma cell colony and sphere formation and sensitized glioma spheres to temozolomide (TMZ) toxicity. In addition, SOX9-shRNA and PDK1 inhibitor could greatly sensitize GSC to TMZ in vivo. Taken together, our data reveals that SOX9-PDK1 axis is a key regulator of GSC self-renewal and GSC temozolomide resistance. These findings may provide help for future human GBM therapy.

Clinical significance of Iroquois Homeobox Gene - IRX1 in human glioma.

The present study aimed to investigate the location, expression and clinical significance of Iroquois homeobox gene (IRX1) in human glioma. The expression of IRX1 gene in glioma cell lines (U87, U373, LN229 and T98G) and normal brain tissue was detected via reverse transcription-polymerase chain reaction. The IRX1 protein in fresh glioma specimens, with the adjacent normal brain tissue, was quantified through western blotting. The archived glioma only specimens from the present hospital and glioma specimens with adjacent normal brain tissue, from Alenabio biotechnology, were subjected to immunohistochemistry and tissue microarray analysis, respectively. The Kaplan-Meier method was employed to assess the correlation between the IRX1 level and the overall survival time of the patients. IRX1 gene was demonstrated to be expressed at varying levels in U373, LN229 and T98G cells, however not in U87 cells and normal brain tissue. Western blotting revealed increased IRX1 expression in glioma tissue compared with adjacent normal brain tissue. Furthermore, a direct correlation was observed between the IRX1 expression and the clinical glioma grade, with a significant difference in the gene expression between high grade and low grade glioma (P<0.05). Notably, IRX1 was identified to be localized to the cytoplasm in the adjacent normal brain and World Health Organization grade I glioma, whereas was identified to be present in the nucleus in higher grade glioma. In addition to being established as a significant prognostic variable, IRX1 expression was positively correlated with the overall survival of glioma patients. IRX1 gene may therefore exhibit an oncogenic role in glioma condition, and thus may be of clinical importance as a future therapeutic target.

Protection of melatonin in experimental models of newborn hypoxic-ischemic brain injury through MT1 receptor.

The function of melatonin as a protective agent against newborn hypoxic-ischemic (H-I) brain injury is not yet well studied, and the mechanisms by which melatonin causes neuroprotection in neurological diseases are still evolving. This study was designed to investigate whether expression of MT1 receptors is reduced in newborn H-I brain injury and whether the protective action of melatonin is by alterations of the MT1 receptors. We demonstrated that there was significant reduction in MT1 receptors in ischemic brain of mouse pups in vivo following H-I brain injury and that melatonin offers neuroprotection through upregulation of MT1 receptors. The role of MT1 receptors was further supported by observation of increased mortality in MT1 knockout mice following H-I brain injury and the reversal of the inhibitory role of melatonin on mitochondrial cell death pathways by the melatonin receptor antagonist, luzindole. These data demonstrate that melatonin mediates its neuroprotective effect in mouse models of newborn H-I brain injury, at least in part, by the restoration of MT1 receptors, the inhibition of mitochondrial cell death pathways and the suppression of astrocytic and microglial activation.

Hexokinase 2 (HK2), the tumor promoter in glioma, is downregulated by miR-218/Bmi1 pathway.

In cancer, glycolysis driving enzymes and their regulating microRNAs are one of the key focus of oncology research lately. The glycolytic enzyme hexokinase 2 (HK2) is crucial for the Warburg effect in human glioma, the most common malignant brain tumor. In the present study, we studied the tumorigenic role of HK2 in glioma, and clarified the mechanism of miR-218 induced HK2 regulation in glioma development. The HK2 expression in patient derived glioma and non neoplastic brain tissue was quantified. The HK2 silenced U87 and U251 cell lines were assessed for their proliferation, migration and invasive potential in vitro, while the tumor forming potential of U87 cells was evaluated in vivo. The untreated cell lines served as control. The HK2 expression in (a) lentivirus-infected, miR-218 overexpressing and (b) shRNA mediated Bmi1 silenced U87 and U251 glioma cell lines were quantified. Luciferase reporter assay, qRT-PCR analysis and WB were employed as required. The HK2 expression was significantly increased in glioma tissues comparing with the non neoplastic brain tissues and was positively correlated with the glioma grade. Silencing HK2 in glioma cell lines significantly decreased their proliferation, migration, invasion and tumorigenic abilities. Although, overexpression of miR-218 significantly downregulated the HK2 expression, luciferase reporter assay failed to show HK2 as the direct target of miR-218. A direct correlation, however, was observed between HK2 and Bmi-1, the direct target of miR-218. Taken together, our findings confirmed the tumorigenic activity of HK2 in glioma, and the involvement of the miR218/Bmi1 pathway in the regulation of its expression.

iRhom2 deficiency relieves TNF-α associated hepatic dyslipidemia in long-term PM2.5-exposed mice.

Accumulating researches reported that particulate matter (PM2.5) is a risk factor for developing various diseases, including metabolic syndrome. Recently, inactive rhomboid protein 2 (iRhom2) was considered as a necessary modulator for shedding of tumor necrosis factor-α (TNF-α) in immune cells. TNF-α, a major pro-inflammatory cytokine, was linked to various pathogenesis of diseases, including dyslipidemia. Here, wild type (WT) and iRhom2-knockout (iRhom2-/-) mice were used to investigate the effects of iRhom2 on PM2.5-induced hepatic dyslipidemia. The hepatic histology, inflammatory response, glucose tolerance, serum parameters and gene expressions were analyzed. We found that long-term inhalation of PM2.5 resulted in hepatic steatosis. And a significant up-regulation of iRhom2 in liver tissues was observed, accompanied with elevated TNF-α, TNF-α converting enzyme (TACE), TNFα receptor (TNFR)2 and various inflammatory cytokines expressions. Additionally, PM2.5 treatment caused TG and TC accumulation in serum and liver, probably attributed to changes of genes modulating lipid metabolism. Intriguingly, hepatic injury and dyslipidemia were attenuated by iRhom2-/- in mice with PM2.5 challenge. In vitro, iRhom2-knockdwon reduced TNF-α expressions and its associated inflammatory cytokines in Kupffer cells, implying that liver-resident macrophages played an important role in regulating hepatic inflammation and lipid metabolism in cells treated with PM2.5. The findings indicated that long-term PM2.5 exposure caused hepatic steatosis and dyslipidemia through triggering inflammation, which was, at least partly, dependent on iRhom2/TNF-α pathway in liver-resident macrophages.