Assessment spermatogenic cell apoptosis and the transcript levels of metallothionein and p53 in Meretrix meretrix induced by cadmium.

Cadmium (Cd) has been widely used in industry and can accumulate in the water, soil, and food. Meretrix meretrix is one of the marine shellfishes cultivated for economic purpose in China. The increasing Cd levels in coastal marine water could adversely affect the economic benefits of shellfish cultivation. In the present study, M. meretrix were exposed to different Cd2+ concentrations (0, 1.5, 3, 6, and 12 mg L-1) for 5 d to evaluate the effects of Cd on spermatogenic cell. The Cd accumulation, survival rate and the indices of oxidative stress and apoptosis were determined in the spermatogenic cells of M. meretrix. The expression levels of p53 and metallothionein (MT) mRNA were also measured in the spermatogenic cells. Cd accumulation and the mortality rate of spermatogenic cells were found to increase in a dose-response manner with Cd2+ concentrations. Histopathology changes, especially the damage of membranous structure, were more severe as the Cd2+ levels in the testis became higher. The indexes of oxidative stress, including reactive oxygen species, malondialdehyde, protein carbonyl derivates and DNA-protein crosslinks all increased after exposure to Cd2+. However, the total antioxidant capacity gradually decreased with the increasing Cd2+ concentration. In addition, exposure to Cd2+ increased the apoptotic rate and caspase-3 and 9 activities but decreased the level of mitochondrial membrane potential and cytochrome C oxidase in the spermatogenic cells. MT mRNA expression increased in lower Cd2+ concentration treated groups whereas decreased in higher groups, while the p53 mRNA expression increased in a dose-response manner with Cd2+ and was positively correlated with the oxidative damage indices. These results indicated that Cd2+ caused oxidative stress and p53 induced apoptosis in the spermatogenic cells, and thus decreased the survival rate of sperm cells. This finding highlights that Cd can reduce the reproductive capacity of M. meretrix, thus threatening to wild shellfish populations and reducing the efficiency of shellfish farming.

Umbilical cord-derived mesenchymal stromal/stem cells expressing IL-24 induce apoptosis in gliomas.

Although much progress has been made in the treatment of gliomas, the prognosis for patients with gliomas is still very poor. Stem cell-based therapies may be promising options for glioma treatment. Recently, many studies have reported that umbilical cord-derived mesenchymal stromal/stem cells (UC-MSCs) are ideal gene vehicles for tumor gene therapy. Interleukin 24 (IL-24) is a pleiotropic immunoregulatory cytokine that has an apoptotic effect on many kinds of tumor cells and can inhibit the growth of tumors specifically without damaging normal cells. In this study, we investigated UC-MSCs as a vehicle for the targeted delivery of IL-24 to tumor sites. UC-MSCs were transduced with lentiviral vectors carrying green fluorescent protein (GFP) or IL-24 complementary DNA. The results indicated that UC-MSCs could selectively migrate to glioma cells in vitro and in vivo. Injection of IL-24-UC-MSCs significantly suppressed tumor growth of glioma xenografts. The restrictive efficacy of IL-24-UC-MSCs was associated with the inhibition of proliferation as well as the induction of apoptosis in tumor cells. These findings indicate that UC-MSC-based IL-24 gene therapy may be able to suppress the growth of glioma xenografts, thereby suggesting possible future therapeutic use in the treatment of gliomas.

The Role of Smurf1 in Neuronal Necroptosis after Lipopolysaccharide-Induced Neuroinflammation.

The role of inflammation in neurological disorders such as Alzheimer's disease and Parkinson's disease is gradually recognized and leads to an urgent challenge. Smad ubiquitination regulatory factor 1 (Smurf1), one member of the HECT family, is up-regulated by proinflammatory cytokines and associated with apoptosis in acute spinal cord injury. However, the function of Smurf1 through promoting neuronal necroptosis is still limited in the central nervous system (CNS). Hence, we developed a neuroinflammatory model in adult rats following lipopolysaccharide (LPS) lateral ventral injection to elaborate whether Smurf1 is involved in necroptosis in CNS injury. The up-regulation of Smurf1 detected in the rat brain cortex was similar to the necroptotic marker RIP1 expression in a time-dependent manner after LPS-induced neuroinflammation. Meanwhile, Smurf1 knockdown with siRNA inhibited neuronal necroptosis following LPS-stimulated rat pheochromocytomal PC12 cells. Thus, it was indicated that LPS-induced necroptosis could be promoted by Smurf1. In short, these studies suggest that Smurf1 might promote neuronal necroptosis after LPS-induced neuroinflammation, which might act as a novel and potential molecular target for the treatment of neuroinflammation associated diseases.

Hck Promotes Neuronal Apoptosis Following Intracerebral Hemorrhage.

The hematopoietic cell kinase (Hck) is a member of the Src family protein kinases which regulates many signal transduction pathways including cell growth, proliferation, differentiation, migration, and apoptosis. However, the expression and function of Hck after intracerebral hemorrhage (ICH) are unknown. Western blot, immunohistochemistry, and immunofluorescence showed that Hck was obviously up-regulation in neurons adjacent to the hematoma after ICH. In addition, the temporary raise of Hck expression was paralleled with the expression of p53, Bax, and active caspase-3, suggesting that Hck was involved in neuronal apoptosis. Hck siRNA dramatically decrease hemin-induced expression of p53, Bax, and active caspase-3 as well as the amount of apoptotic SH-SY5Y cells in vitro. Furthermore, Hck interacted with p53. Hence, Hck might promote neuronal apoptosis via p53 signaling pathway after ICH.

O-GlcNAc Glycosylation of nNOS Promotes Neuronal Apoptosis Following Glutamate Excitotoxicity.

Ischemic stroke is a dominant health problem with extremely high rates of mortality and disability. The main mechanism of neuronal injury after stroke is excitotoxicity, during which the activation of neuronal nitric oxide synthase (nNOS) exerts a vital role. However, directly blocking N-methyl-D-aspartate receptors or nNOS can lead to severe undesirable effects since they have crucial physiological functions in the central nervous system. Here, we report that nNOS undergoes O-linked-ß-N-acetylglucosamine (O-GlcNAc) modification via interacting with O-GlcNAc transferase, and the O-GlcNAcylation of nNOS remarkably increases during glutamate-induced excitotoxicity. In addition, eliminating the O-GlcNAcylation of nNOS protects neurons from apoptosis during glutamate stimulation by decreasing the formation of nNOS-postsynaptic density protein 95 complexes. Taken together, our data suggest a novel function of the O-GlcNAcylation of nNOS in neuronal apoptosis during glutamate excitotoxicity, suggesting a novel therapy strategy for ischemic stroke.

Up-regulation of MCM3 Relates to Neuronal Apoptosis After Traumatic Brain Injury in Adult Rats.

Minichromosome maintenance complex component 3, one of the minichromosome maintenance proteins, functions as a part of pre-replication complex to initiate DNA replication in eukaryotes. Minichromosome maintenance complex component 3 (MCM3) was mainly implied in cell proliferation and tumorigenesis. In addition, MCM3 might play an important role in neuronal apoptosis. However, the functions of MCM3 in central nervous system are still with limited acquaintance. In this study, we performed a traumatic brain injury (TBI) model in adult rats. Western blot and immunohistochemistry staining showed up-regulation of MCM3 in the peritrauma brain cortex. The expression patterns of active caspase-3 and Bax, Bcl-2 were parallel with that of MCM3. Immunofluorescent staining and terminal deoxynucleotidyl transferase-mediated biotinylated-dUTP nick-end labeling suggested that MCM3 was involved in neuronal apoptosis. In conclusion, our data indicated that MCM3 might play an important role in neuronal apoptosis following TBI. Further understanding of these insights could serve as the basis for broadening the therapeutic scope against TBI.

The Contribution of Necroptosis in Neurodegenerative Diseases.

Over the past decades, cell apoptosis has been significantly reputed as an accidental, redundant and alternative manner of cell demise which partakes in homeostasis in the development of extensive diseases. Nevertheless, necroptosis, another novel manner of cell death through a caspase-independent way, especially in neurodegenerative diseases remains ambiguous. The cognition of this form of cell demise is helpful to understand other forms of morphological resemblance of necrosis. Additionally, the concrete signal mechanism in the regulation of necroptosis is beneficial to the diagnosis and treatment of neurodegenerative diseases. Recent studies have demonstrated that necroptotic inhibitor, 24(S)-Hydroxycholesterol and partial specific histone deacetylase inhibitors could alleviate pathogenetic conditions of neurodegenerative diseases via necroptosis pathway. In this review, we summarize recent researches about mechanisms and modulation of necroptotic signaling pathways and probe into the role of programmed necroptotic cell demise in neurodegenerative diseases such as Parkinson's disease, Multiple sclerosis, Amyotrophic lateral sclerosis.

Spatiotemporal Patterns of RING1 Expression after Rat Spinal Cord Injury.

Ring finger protein 1 (RING1) is a RING domain characterized protein belonging to the RING finger family. It is an E3 ubiquitin-protein ligase that mediated monoubiquitination of histone H2A and the core component of PRC1 complex, which is the repressive multiprotein complex of Polycomb group (PcG). Previous studies showed the important tumorigenic role of RING1 via promoting cell proliferation and the crucial function in maintaining transcriptional program stability during development. However, its mechanism for spinal cord injury (SCI) is still unknown. In our research, we established an acute SCI model in adult rats and studied the expression and function profiles of RING1. RING1 protein level detected by western blot peaked at day 3 after trauma and then decreased gradually. Immunohistochemistry showed the increase of RING1 expression displayed in the white matter more obviously than in the gray matter. Furthermore, increased co-expression of RING1 and GFAP confirmed activated astrocytes in injured spinal cord via double immunofluorescence staining. Meanwhile, we also found the co-localization of PCNA, a famous marker of proliferative cells, with RING1 and GFAP, which indicated RING1 might play a role in astrocyte proliferation after SCI. In vitro studies, RING1 protein level in C6 cells increased after LPS challenge and RING1 was required for astrocyte proliferation and activation induced by LPS. In summary, we took a new insight into the function of RING1 in the cellular and molecular mechanism underlying the pathophysiology of SCI.

Nrdp1 is Associated with Neuronal Apoptosis in Lipopolysaccharide-Induced Neuroinflammation.

Neuregulin receptor degradation protein-1 (Nrdp1), a kind of ring finger E3 ubiquitin ligase, is expressed in several adult tissues, including the heart, testis, prostate and brain. Studies of this molecule have demonstrated its great importance in regulating cell growth, apoptosis and oxidative stress in various cell types. However, information regarding its expression and possible function in the central nervous system is still limited. In this study, we performed a neuroinflammation model by lipopolysaccharide (LPS) lateral ventral injection in adult rats. It was found that the expression of Nrdp1 was significantly increased in cerebral cortex after LPS injection. Immunofluorescence indicated that Nrdp1 was located in the neurons, but not astrocytes or microglia. Furthermore, there was a concomitant up-regulation of active caspase-3 and decreased expression of BRUCE (an inhibitor of apoptosis protein). In addition, decreasing Nrdp1 levels by RNA interference in cortical primary neurons reduced active caspase-3 expression but induced up-regulation of BRUCE. Collectively, all these results suggested that Nrdp1 might play a role in neuronal apoptosis by reducing the expression of BRUCE in neuroinflammation after LPS injection.

Up-regulation of Che-1 relates to neuronal apoptosis after traumatic brain injury in adult rats.

Che-1, a recently identified apoptosis related protein, affects the fate of various cell types when under stress. One attractive biological function of Che-1 is promoting the transcription of p53 after DNA damage; besides, it can also regulate cell cycle via interacting with retinoblastoma protein. Although previous evidence has showed its anti-apoptotic role in cancer cells, some studies point out that Che-1 might play an opposite role in central nervous system (CNS). However, the function of Che-1 in CNS is still with limited acquaintance. To investigate whether Che-1 is involved in CNS lesion, we performed a traumatic brain injury model in adult rats. Up-regulation of Che-1 was observed in the peritrauma brain cortex by performing western blotting and immunohistochemistry. Terminal deoxynucleotidyl transferase deoxy-UTP nick-end labeling and 4',6-diamidino-2-phenylindole staining suggested that Che-1 was involved in neuronal apoptosis after brain injury. We also investigated co-localization of Che-1 and active-caspase-3 in the ipsilateral brain cortex. In addition, the expression patterns of p53, Bax and PCNA were parallel with that of Che-1. Besides this, neurotrophin receptor-interacting MAGE homolog was found to be associated with Che-1 after brain trauma. Based on our data, we suggested that Che-1 might play an important role in neuronal apoptosis following TBI; and might provide a basis for the further study on its role in regulating the expression of p53 and cell cycle re-entry in traumatic brain injury.

The role of HSPA12B in regulating neuronal apoptosis.

Heat shock protein A12B (HSPA12B) is the newest member of a recently defined subfamily of proteins distantly related to the 70-kDa family of heat shock proteins (HSP70) family. HSP70s play a crucial role in protecting cells, tissues, organs and animals from various noxious conditions. Here we studied the dynamic expression changes and localization of HSPA12B after middle cerebral artery occlusion (MCAO) with reperfusion induced ischemic insult processes in adult rats. Apoptosis, as indicated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, was also increased in the peri-ischemic cortex compared to non-ischemic hemisphere. The expression of HSPA12B was strongly induced in the ischemic hemisphere of MCAO reperfusion rats in vivo. In vitro studies indicated that the up-regulation of HSPA12B may be involved in oxygen-glucose deprivation-induced PC12 cell death. And knockdown of HSPA12B in cultured differentiated PC12 cells by siRNA showed that HSPA12B inhibited the expression of active caspase-3. Collectively, these results suggested that HSPA12B may be required for protecting neurons from ischemic insults.

Dynamic change of Numbl expression after sciatic nerve crush and its role in Schwann cell differentiation.

Numbl, as a conserved homolog of Drosophila Numb, has been implicated in early development of the nervous system, but its expression and roles in nervous system lesion and repair remained unknown. Here, we performed an acute sciatic nerve injury model in adult rats and studied the dynamic changes of Numbl expression in the sciatic nerve. Temporally, Numbl expression was sharply decreased after sciatic nerve crush and reached a valley at day 7. Spatially, Numbl was widely expressed in the normal sciatic nerve, including axons and Schwann cells, whereas, after injury, Numbl expression was decreased predominantly in Schwann cells. In vitro, we induced Schwann cell differentiation with cAMP and found that Numbl expression was decreased in the differentiated process. Depletion of Numbl could promote Schwann cell differentiation. In addition, we demonstrated that in vitro myelination was suppressed by overexpression of Numbl in Schwann cells. Collectively, we hypothesized peripheral nerve injury induced a downregulation of Numbl in the sciatic nerve, which was associated with Schwann cell differentiation.

Expression of transforming growth factor-ß1 (TGF-ß1) and E-cadherin in glioma.

Gliomas are the most common tumors in the central nervous system. This study aims to investigate the expressions of transforming growth factor-ß1 (TGF-ß1) and epithelial cadherin (E-cadherin) in human brain glioma tissues and the correlation between their expressions with clinical pathological features and clinical significance. The expressions of mRNA or protein of TGF-ß1 and E-cadherin were detected by using reverse transcription polymerase chain reaction (RT-PCR) and Western blot in these tissues. Positive rates of the expression of TGF-ß1 and E-cadherin were 62.9 % and 38.6 % in brain tissues of glioma patients. The expressions of mRNA or protein for TGF-ß1 in brain glioma tissues were significantly higher than that in normal brain tissues (p < 0.01). Their expressions in well-differentiated glioma brain tissues were lower than those in poorly differentiated glioma brain tissues (p < 0.01). A negative correlation was found between TGF-ß1 and E-cadherin in brain glioma tissues (r = -0.302, p < 0.011). The cell numbers of C6 glioma through Transwell chambers were decreased significantly (p < 0.01), and the expression of TGF-ß1 was downregulated significantly (p < 0.01). However, the expression of E-cadherin was upregulated significantly (p < 0.01) after transfecting TGF-ß1 siRNA. The expression changes of TGF-ß1 and E-cadherin may be related to the emergence and the development of glioma. Downregulation of TGF-ß1 expression using siRNA can decrease the invasive capability of C6 glioma cells.

Involvement of CLEC16A in activation of astrocytes after LPS treated.

CLEC16A, C-type lectin domain family 16, member A was recently found to be associated with inflation process in the autoimmune diseases. In this study, we elucidated the dynamic expression changes and localization of CLEC16A in lipopolysaccharide (LPS)-induced neuroinflammatory processes in adult rats. CLEC16A expression was strongly induced in active astrocytes in inflamed cerebral cortex. In vitro studies indicated that the up-regulation of CLEC16A may be involved in the subsequent astrocyte activation following LPS challenge. And Knock-down of CLEC16A in cultured primary astrocytes by siRNA showed that CLEC16A was required for the activation of astrocytes induced by LPS. Collectively, these results suggested CLEC16A may be important in host defense in astrocyte-mediated immune response. Understanding the cell signal pathway may provide a novel strategy against inflammatory and immune reaction in neuroinflammtion in CNS.

Bone marrow stromal cells-loaded chitosan conduits promote repair of complete transection injury in rat spinal cord.

In this study, a chitosan conduit loaded with bone marrow stromal cells (BMSCs) was developed to bridge the gap in the transected spinal cord of adult rats, and the nerve repair outcomes were evaluated by functional and histological techniques at 12 weeks after implantation. As compared to chitosan conduits alone, incorporation of BMSCs within chitosan conduits yielded additional improving effects on nerve regeneration and function restoration. The measurements with the Basso, Beattie and Bresnahan locomotor rating scale or of motor evoked potentials indicated that motor functional recovery was enhanced; retrograde tracing confirmed that the ascending tract was regenerated and the neural pathway was established; and histological analyses revealed that axon growth and remyelination in the regenerated nerve was promoted. The three-dimensional reconstruction showed that the chitosan conduit loaded with BMSCs significantly reduced the spinal cord cavity volume at the injured site. Taken together, the results collectively suggest that implantation with BMSCs-loaded chitosan conduits may become a promising approach to the repair of spinal cord injury.

Casein kinase 1 (CK1) promotes the proliferation and metastasis of glioma cells via the phosphatidylinositol 3 kinase-matrix metalloproteinase 2 (AKT-MMP2) pathway.

BACKGROUND: Glioma is a type of tumor that usually occurs in the adult central nervous system. Protein kinases have become important targets for oncotherapy since they are closely correlated with signal transduction. The role of the casein kinase 1 (CK1) gene in glioma remains to be fully elucidated. METHODS: The mRNA and protein expression of CK1 were analyzed by Realtime PCR, Western blot and immunohistochemistry. The cell behavior was assayed by MTT, Transwell and cell scratch methods. Cell cycle and cell apoptosis were performed by flow cytometer. Construction of stable cell line was completed by lentivirus infection. The nude mouse model was used for in vivo analysis on the role of CK1 by injecting the cells into subcutaneous tissue, tail vein and cerebral cortex. The prognostic role of CK1 in glioma was evaluated using Kaplan-Meier and Cox regression analyses. RESULTS: immunohistochemical staining demonstrated that the expression of CK1 in glioma samples was correlated with the grade of glioma. Survival analysis using Kaplan-Meier and multivariate analysis by Cox regression indicated that CK1 could be used as an independent prognostic marker for glioma. The methyl thiazolyl tetrazolium (MTT), transwell, and cell scratch assays demonstrated that the CK1 gene promoted cell proliferation and invasion through the phosphatidylinositol 3 kinase/matrix metalloproteinase 2 (AKT-MMP2) signaling pathway. In vivo experiments in mice also confirmed the ability of CK1 to enhance tumor proliferation and metastasis, with the metastatic site being the small intestine. CONCLUSIONS: the expression of CK1 was correlated with glioma grade and patient survival and it may enhance glioma proliferation and metastasis via AKT-MMP2 pathway.

Knockdown of DSPP inhibits the migration and invasion of glioma cells.

Dentin sialophosphoprotein (DSPP) is a member of the SIBLING (Small integrin-binding ligand N-linked glycoproteins) family of phosphoglycoproteins and has been proved to contribute to the migration of a variety of solid tumor cells. However, whether DSPP participates in the pathogenic process of glioma remains unknown. In this study, we aimed to investigate the expression and biological function of DSPP in human glioma cells. We demonstrated through Western blot that DSPP is overexpressed in glioma tissues comparing to normal brain tissues. To investigate the role of DSPP in glioma carcinogenesis, we reduced the DSPP expression by small interfering RNA (siRNA) and found that DSPP silencing significantly inhibited the migration and invasion of glioma cells, the critical characteristics of glioma. Furthermore, we showed that DSPP down-regulation significantly decreased the activation of the AKT/mTOR/p70S6K pathway in glioma cells. Taken together, these findings indicate that knockdown of DSPP inhibits glioma cells migration and invasion, suggesting that targeting DSPP might be a potentially effective therapeutic strategy for treating glioma.

The burden of stroke in China: Results from a nationwide population-based epidemiological survey.

Stroke is a serious threat to human health that often leads to severe complications, and currently ranks first as leading cause of death in China. However, reliable data on stroke burden in China in the 21st century are lacking. We used the data from NESS-China (National Epidemiological Survey of Stroke in China) for assessing the adverse health effects of stroke in Chinese population. We carried out inter-regional comparative study in order to obtain regular burden related characteristics of stroke in China, as measured by YLLs (years of life lost due to premature mortality), YLDs (years lived with disability) and DALYs (disability adjusted life years). Amongst the nationwide population of 596,536 individuals of all ages in 2013, the YLLs for stroke was 1748, the YLDs was 262, and the DALYs was 2010(per 100,000). The gender subtype analysis of DALYs was 2171(male) and 1848(female). The YLLs, YLDs and DALYs in rural areas were higher compared to urban areas. Among the 18 age groups, the highest YLLs was observed in ≥ 80 years old group. The impact of stroke on Chinese population is more severe compared to the global average levels. Stroke results as the main cause of YLLs in China, while there is no significant difference for the YLDs. Nevertheless, DALYs caused by stroke rank 3th in global epidemiologic study territories, 1st in China.

[Proteomic analysis of rat astrocytes and C6 glioma cells].

OBJECTIVE: To compare the protein profiles between glioma cells and normal astrocytes. METHODS: Proteomic assay was performed on human C6 glioma cells and purified SD rat astrocytes. Two-dimensional gel electrophoresis (2-DE) and PDQuest software were applied for the comparison of protein image between the C6 cells and astrocytes. The differential protein spots were identified with Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and further bioinformatic analysis. The differential expression of the interesting genes was confirmed by semi-quantitative RT-PCR. RESULTS: Twenty-four differential protein spots were revealed by 2-DE assay. The peptide mass fingerprints (PMFs) of 17 proteins were obtained by MALDI-TOF-MS. Among them, six proteins were determined by further bioinformatic analysis. Compared with the expression level in astrocytes, the identified proteins showed higher expression level in the C6 glioma cells including phosphoglycerate mutase 1, glutathione S-transferase P (GST P), annexin A2 and calreticulin, while the proteins showed lower expression level included vimentin and gamma-actin. The results of RT-PCR confirmed the differential expressions of phosphoglycerate mutase 1, annexin A2 and vimentin identified by 2-DE assay. CONCLUSION: The identified proteins differentially expressed in C6 cells and astrocytes are associated with many important cellular processes and functions such as anaerobic glycolysis, cytoskeleton organization, biotransformation, and signal transduction, and play important roles in tumor growth, migration, and anti-cancer drug resistance.