Inhibition of voltage-gated sodium ion channel by corannulene and computational inversion blockage underlying mechanisms.

Corannulene (Cor), a special carbon material, evidenced strong protein binding capacity which regulating lysozyme crystallization and controlling reactive oxygen species (ROS) generation. Ion channel protein play role in regulating ion channel functions to affect physiological functions. However, the interaction between Cor and ion channel protein have not been studied. In this study, PEG/Cor nanoparticles (PEG/Cor Nps) were prepared by mPEG-DSPE. The PEG/Cor Nps localized in cytoplasm and produced cytotoxicity at high concentration. Whole cell patch clamp examined ion channel functions after incubate PEG/Cor Nps with PC-12 cell. we found that PEG/Cor Nps inhibited voltage-gated Na+ ion channels in a dose- and time-dependent manner but not act on voltage-gated K+ ion channels. The potential mechanisms were revealed by all-atom molecular dynamic (MD) simulations. The results showed that PEG/Cor Nps block the pore of sodium ion channel protein due to dose- and time-dependent accumulation. Besides, the orientation angle (θ) configuration of PEG/Cor Nps will be inverted with the accumulation to generate two blocking mechanisms. Different from other carbon nanomaterials, the blockage mechanism of PEG/Cor Nps provides novel insights into the mechanisms of interaction between carbon nanomaterials and protein.

TRPC6 interacted with KCa1.1 channels to regulate the proliferation and apoptosis of glioma cells.

Malignant glioma is the most aggressive and deadliest brain malignancy. TRPC6 and KCa1.1, two ion channels, have been considered as potential therapeutic targets for malignant glioma treatment. TRPC6, a Ca2+-permeable channel, plays a vital role in promoting tumorigenesis and the progression of glioma. KCa1.1, a large-conductance Ca2+-activated channel, is also involved in growth and migration of glioma. However, the underlying mechanism by which these two ion channels promote glioma progression was unclear. In our study, we found that TRPC6 upregulated the expression of KCa1.1, while the immunoprecipitation analysis also showed that TRPC6 interacts with KCa1.1 channels in glioma cells. The currents of KCa1.1 recorded by the whole-cell patch clamp technique were increased by TRPC6 in glioma cells, suggesting that TRPC6 can provide a Ca2+ source for the activation of KCa1.1 channels. It was also suggested that TRPC6 regulates the proliferation and apoptosis of glioma cells through KCa1.1 channels in vitro. Therefore, C6-bearing glioma rats were established to validate the results in vitro. After the administration of paxilline (a specific inhibitor of KCa1.1 channels), TRPC6-dependent growth of glioma was inhibited in vivo. We also found that TRPC6 enhanced co-expression with KCa1.1 in glioma. These all suggested that TRPC6/KCa1.1 signal plays a role in promoting the growth of glioma. Our results provided new evidence for TRPC6 and KCa1.1 as potential targets for glioma treatment.

The inhibition of BDNF/TrkB/PI3K/Akt signal mediated by AG1601 promotes apoptosis in malignant glioma.

Malignant glioma is the most aggressive primary brain tumor and has a poor survival rate. Even if extensive methods are preformed to treat glioma, the mortality rate is still very high. It is necessary for discovering and developing new drugs for malignant glioma treatment. AG1601 is one of AG-series drugs, including AG1031 and AG1503, and it has been optimized on the original basis. In our study, we found that AG1601 markedly inhibited proliferation and promoted C6 glioma cell apoptosis in vitro. AG1601 also reduced the size and weight of glioma in vivo. The growth ability of glioma was significantly inhibited after treatment with AG1601. It also showed that the expression levels of BDNF/TrkB/PI3K/Akt signal related proteins were obviously decreased in C6 glioma cells after treatment with AG1601 in vivo and in vitro. We also found that BDNF, as the activator of BDNF/TrkB/PI3K/Akt signal, reversed the anti-proliferation and pro-apoptosis of C6 glioma cells caused by AG1601. K252a, a specific inhibitor of TrkB, and AG1601 in combination aggravated C6 glioma cell apoptosis. These results indicate that AG1601 has good effects on the anti-proliferation and pro-apoptosis of malignant glioma via BDNF/TrkB/PI3K/Akt signal and could be considered as a potential drug in treating malignant glioma.

Pretreatment-Etidronate Alleviates CoCl2 Induced-SH-SY5Y Cell Apoptosis via Decreased HIF-1α and TRPC5 Channel Proteins.

Chronic hypoxic damage is one of the most common pathogenic factors that can cause neurodegenerative disorder in most cases. Etidronate (Eti) is one of the best-known earlier-generations of bisphosphonate derivatives for the treatment of bone-loss related diseases. Building on the preceding study of our laboratory, we found that Eti showed neuroprotective effects against 2-vessel occlusion induced vascular dementia (VD) in rats. Therefore, in this study, we attempted to elucidate the mechanism of action, which Eti protected cells from chronic hypoxic damage caused by CoCl2 in SH-SY5Y cells in vitro. Our data showed that the pretreatment with 100 µM Eti partially improved hypoxic damage in cell viability and reduced the hypoxia-inducible factor-1α (HIF-1α) expression, which indicated chronic hypoxic level. Furthermore, the protein expression of TRPC5 channel and its mediated intracellular calcium ion concentration ([Ca2+]i) were decreased. In addition, the apoptosis-related proteins caspase-9, and caspase-3 as well as calcium/calmodulin-dependent protein kinase II (CaMK-II) were down-regulated after treatment with Eti. In conclusion, Eti shows neuroprotective effects on SH-SY5Y cells injured by CoCl2 through resisting apoptosis caused by calcium influx, which may be related to the inhibition of HIF-1α protein and the decreased TRPC5 channel protein.

Excessive corticosterone induces excitotoxicity of hippocampal neurons and sensitivity of potassium channels via insulin-signaling pathway.

Corticosterone (CORT) is a kind of corticosteroid produced by cortex of adrenal glands. Hypothalamic-pituitary-adrenal (HPA) axis hyperfunction leads to excessive CORT, which is associated with depression. Few studies have investigated the role of CORT in voltage-gated ion channels and its upstream signaling pathway in central nervous system. In this study, we investigated the mechanism of excessive CORT resulting in brain impairment on voltage-gated ion channels, and its upstream signaling effectors in hippocampal CA1 neurons. The action potential (AP) and voltage-gated potassium currents were determined by using whole-cell patch-clamp. Insulin and CORT improved the neuronal excitability. Independent effects existed in transient potassium channel (IA) and delay rectifier potassium channel (IK). The inhibition of potassium currents, IA in our experiment, could increase neuronal excitability. CORT led to the excitotoxicity of hippocampal neurons via phosphatidylinositol 3 kinase (PI3K)-mediated insulin-signaling pathway. Therefore, the stimulation of excessive CORT induces excitotoxicity of hippocampal neurons and sensitivity of potassium channels via PI3K-mediated insulin-signaling pathway, which indicates one possible way of depression treatment.

Effects of miR-200b-3p inhibition on the TRPC6 and BKCa channels of podocytes.

Transient receptor potential canonical 6 (TRPC6) and large-conductance Ca2+-activated K+ channels (BKCa), two of the key ion channels for blood filtration function of podocytes, have been implicated in the pathogenesis of kidney diseases. Moreover, it has been reported that miR-200 b plays an important role in regulating the biological processes of podocytes. In this study, we aimed to examine whether there was a relationship between miR-200 b-3p and the two ion channels. It was suggested that miR-200 b-3p down-regulation inhibited the currents of TRPC6 and BKCa channels. It also showed that miR-200 b-3p inhibition reduced the levels of protein expression and mRNA transcription of TRPC6 and BKCa channels. Moreover, the down-regulation of miR-200 b-3p resulted in the decrease of the intracellular Ca2+ concentration. It was also suggested that the decrease of BKCa currents resulting from miR-200 b-3p inhibition could be regulated by TRPC6 channels. TRPC6 blockage also inhibited BKCa currents and reduced the level of BKCa expression. These results together suggested that miR-200 b-3p inhibition reduced the currents of TRPC6, which led to the decrease of intracellular Ca2+ concentration. The decrease of Ca2+ source required for BKCa activation may result in the inhibition of BKCa currents.

Nano-TiO2 induces autophagy to protect against cell death through antioxidative mechanism in podocytes.

Autophagy is a cellular pathway involved in degradation of damaged organelles and proteins in order to keep cellular homeostasis. It plays vital role in podocytes. Titanium dioxide nanoparticles (nano-TiO2) are known to induce autophagy in cells, but little has been reported about the mechanism of this process in podocytes and the role of autophagy in podocyte death. In the present study, we examined how nano-TiO2 induced authophagy. Besides that, whether autophagy could protect podocytes from the damage induced by nano-TiO2 and its mechanism was also investigated. Western blot assay and acridine orange staining presented that nano-TiO2 significantly enhanced autophagy flux in podocytes. In addition, AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) were involved in such process. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that upregulated level of autophagy induced by rapamycin in high concentration nano-TiO2-treated podocytes could significantly reduce the level of oxidative stress and alleviate podocyte death. Downregulating the level of autophagy with 3-methyladenine had the opposite effects. These findings indicate that nano-TiO2 induces autophagy through activating AMPK to inhibit mTOR in podocytes, and such autophagy plays a protecting role against oxidative stress on the cell proliferation. Changing autophagy level may become a new treatment strategy to relieve the damage induced by nano-TiO2 in podocytes.

Multichannel-optical imaging for in vivo evaluating the safety and therapeutic efficacy of stem cells in tumor model in terms of cell tropism, proliferation and NF-κB activity.

Stem cell-based cancer treatment has garnered significant attention, yet its safety and efficacy remain incompletely understood. The nuclear factor-kappa B (NF-κB) pathway, a critical signaling mechanism involved in tumor growth, angiogenesis, and invasion, serves as an essential metric for evaluating the behavior of stem cells in tumor models. Herein, we report the development of a triple-channel imaging system capable of simultaneously monitoring the tropism of stem cells towards tumors, assessing tumor proliferation, and quantifying tumor NF-κB activity. In this system, we generated a CRISPR-Cas9 gene-edited human glioblastoma cell line, GE-U87-MG, which provided a reliable readout of the proliferation and NF-κB activity of tumors by EF1α-RFLuc- and NF-κB-GLuc-based bioluminescent imaging, respectively. Additionally, near infrared-II emitting Tat-PEG-AgAuSe quantum dots were developed for tracking of stem cell tropism towards tumor. In a representative case involving human mesenchymal stem cells (hMSCs), multichannel imaging revealed no discernible effect of hMSCs on the proliferation and NF-κB activity of GE-U87-MG tumors. Moreover, hMSCs engineered to overexpress the necrosis factor-related apoptosis-inducing ligand were able to inhibit NF-κB activity and growth of GE-U87-MG in vivo. Taken together, our imaging system represents a powerful and feasible approach to evaluating the safety and therapeutic efficacy of stem cells in tumor models.

Social Deficits and Cerebellar Degeneration in Purkinje Cell Scn8a Knockout Mice.

Mutations in the SCN8A gene encoding the voltage-gated sodium channel α-subunit Nav1. 6 have been reported in individuals with epilepsy, intellectual disability and features of autism spectrum disorder. SCN8A is widely expressed in the central nervous system, including the cerebellum. Cerebellar dysfunction has been implicated in autism spectrum disorder. We investigated conditional Scn8a knockout mice under C57BL/6J strain background that specifically lack Scn8a expression in cerebellar Purkinje cells (Scn8a flox/flox , L7Cre + mice). Cerebellar morphology was analyzed by immunohistochemistry and MR imaging. Mice were subjected to a battery of behavioral tests including the accelerating rotarod, open field, elevated plus maze, light-dark transition box, three chambers, male-female interaction, social olfaction, and water T-maze tests. Patch clamp recordings were used to evaluate evoked action potentials in Purkinje cells. Behavioral phenotyping demonstrated that Scn8a flox/flox , L7Cre + mice have impaired social interaction, motor learning and reversal learning as well as increased repetitive behavior and anxiety-like behaviors. By 5 months of age, Scn8a flox/flox , L7Cre + mice began to exhibit cerebellar Purkinje cell loss and reduced molecular thickness. At 9 months of age, Scn8a flox/flox , L7Cre + mice exhibited decreased cerebellar size and a reduced number of cerebellar Purkinje cells more profoundly, with evidence of additional neurodegeneration in the molecular layer and deep cerebellar nuclei. Purkinje cells in Scn8a flox/flox , L7Cre + mice exhibited reduced repetitive firing. Taken together, our experiments indicated that loss of Scn8a expression in cerebellar Purkinje cells leads to cerebellar degeneration and several ASD-related behaviors. Our study demonstrated the specific contribution of loss of Scn8a in cerebellar Purkinje cells to behavioral deficits characteristic of ASD. However, it should be noted that our observed effects reported here are specific to the C57BL/6 genome type.

Reaction-Diffusion Model-Based Research on Formation Mechanism of Neuron Dendritic Spine Patterns.

The pattern abnormalities of dendritic spine, tiny protrusions on neuron dendrites, have been found related to multiple nervous system diseases, such as Parkinson's disease and schizophrenia. The determination of the factors affecting spine patterns is of vital importance to explore the pathogenesis of these diseases, and further, search the treatment method for them. Although the study of dendritic spines is a hot topic in neuroscience in recent years, there is still a lack of systematic study on the formation mechanism of its pattern. This paper provided a reinterpretation of reaction-diffusion model to simulate the formation process of dendritic spine, and further, study the factors affecting spine patterns. First, all four classic shapes of spines, mushroom-type, stubby-type, thin-type, and branched-type were reproduced using the model. We found that the consumption rate of substrates by the cytoskeleton is a key factor to regulate spine shape. Moreover, we found that the density of spines can be regulated by the amount of an exogenous activator and inhibitor, which is in accordance with the anatomical results found in hippocampal CA1 in SD rats with glioma. Further, we analyzed the inner mechanism of the above model parameters regulating the dendritic spine pattern through Turing instability analysis and drew a conclusion that an exogenous inhibitor and activator changes Turing wavelength through which to regulate spine densities. Finally, we discussed the deep regulation mechanisms of several reported regulators of dendritic spine shape and densities based on our simulation results. Our work might evoke attention to the mathematic model-based pathogenesis research for neuron diseases which are related to the dendritic spine pattern abnormalities and spark inspiration in the treatment research for these diseases.

MiR-429/200a/200b negatively regulate Notch1 signaling pathway to suppress CoCl2-induced apoptosis in PC12 cells.

Neuronal apoptosis is a central hallmark of cerebral ischemia, which is serious threats to human health. Notch1 signaling pathway and three members of miR-200 family, miR-429, miR-200a and miR-200b, are reported to have tight connection with hypoxia-induced injury. However, their mutual regulation relationship and their roles in neuronal apoptosis caused by hypoxia are rarely reported. In the present study, differentiated pheochromocytoma (PC12) cells were treated with chemical hypoxia inducer, cobalt chloride (CoCl2) to establish in vitro neuronal hypoxia model. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, Western blot assay and Hoechst staining indicated that CoCl2 caused apoptosis of PC12 cells along with the activation of Notch1 signallilng pathway. The treatment of N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butylester (DAPT) inhibited Notch1 signaling pathway and attenuated the apoptosis induced by CoCl2. Real-time polymerase chain reaction (RT-PCR) showed that expressions of miR-429/200a/200b were dynamically changed during the treatment of CoCl2, and significantly decreased after 12-hour treatment of CoCl2. Overexpression of miR-429/200a/200b inhibited the Notch1 signaling pathway and suppressed CoCl2-induced apoptosis in PC12 cells. These results may clarify the roles of miR-429/200a/200b and Notch1 signaling pathway in hypoxia-induced nerve injury and provide a new theoretical basis to relieve nerve injury.

Deletion of asparagine endopeptidase reduces anxiety- and depressive-like behaviors and improves abilities of spatial cognition in mice.

Mammalian asparagine endopeptidase (AEP) is a lysosomal cysteine protease that cleaves protein substrates on the C-terminal side of asparagine. The expression and activity of AEP are closely related to many pathological conditions that include cancer, atherosclerosis and inflammation. It has been validated that the level of AEP is elevated in aged human and neurodegenerative diseases like Alzheimer's disease (AD). Mood disorder is one of the most emotional symptoms that can be seen in AD patients, which leads us to assume that AEP can modulate affective behaviors. AEP knockout (AEP KO) and wildtype (WT) mice were used in this study, and a series of behavioral tests were performed to establish a potential link between AEP and psychiatric disorders. It was demonstrated that AEP KO mice displayed lower anxiety-like behavior and more advance exploratory behavior in open-field and hole-board tests. AEP KO mice reduced depressive-like behaviors in the forced swim and tail suspension tests. Morris water maze (MWM) test showed that the abilities of spatial learning and memory were elevated in AEP-deletion mice compared with those of WT mice. Furthermore, the enhanced synaptic plasticity (LTP and DPT) as well as the increased expressions of SYP and PSD-95 proteins in hippocampus were showed in AEP KO mice. Otherwise, the level of BDNF protein was reduced and the level of NF-κB p65 protein was increased in hippocampus and frontal cortex of AEP KO mice. These data highlight the importance of studying AEP in the anxiety and depression behaviors and the spatial learning and memory.

Voluntary running-enhanced synaptic plasticity, learning and memory are mediated by Notch1 signal pathway in C57BL mice.

It is well known that voluntary running can enhance synaptic plasticity and improve learning and memory abilities. The Notch1 receptor is also reported to be associated with these processes, but its role in running-induced alterations is unclear. In this study, we aimed to investigate whether the Notch1 signalling pathway was involved in voluntary running-induced enhancement of synaptic plasticity, learning and memory. Notch1 heterozygous deficient (Notch1+/-) mice and wildtype (WT) C57BL littermates were randomly divided into runner group and non-runner group. Mice were given free access to running wheels for 14 days in both the Notch1+/- runner group and the WT runner group. Our results demonstrate that Notch1 knockdown impairs the performance in the novel object recognition (NOR) test and Morris water maze test and decreases the synaptic plasticity. Voluntary running improves spatial learning and memory abilities, promotes synaptic plasticity and increases expressions of postsynaptic proteins in WT mice but not in Notch1+/- mice. Our results suggest that Notch1 plays a vital role in spatial learning and memory, synaptic plasticity under normal physiological conditions and voluntary running conditions. These findings will set the groundwork and fill in some gaps for understanding the role of Notch1 signalling in voluntary running-induced phenomena.

Angiotensin II induces calcium-mediated autophagy in podocytes through enhancing reactive oxygen species levels.

As well known, abnormalities of Angiotensin II (Ang II) is closely related with glomerular damage. This study was to investigate whether Ang II could affect autophagy in podocytes via oxidative stress, and whether autophagy had a positive role in protecting podocytes impaired by Ang II. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that Ang II induced podocyte death. The measurements of malondialdehyde (MDA) and H2O2 levels, and flow cytometry assay revealed that Ang II considerably increased reactive oxygen species (ROS) generation in podocytes. Meaningfully, treatment with ROS scavenger N-(mercaptopropionyl)-glycine (N-MPG) could inhibit podocyte death and attenuate accumulation of ROS induced by Ang II. The patch-clamp experiments indicated that Ang II increased the current of transient receptor potential canonical 6 (TRPC6). Moreover, measurement of Fluo-3 image showed that Ang II increased intracellular Ca2+ level, as N-MPG and La3+ impeded Ang II induced Ca2+ influx. Acridine orange staining indicated that Ang II induced accumulation of acidic vacuoles. Beclin-1 and LC3 are essential for autophagosome formation. Furthermore, as one of the selective substrates for autophagy, P62 plays a key role in the formation of cytoplasmic proteinaceous inclusion. Western blot assay presented that Ang II obviously elevated LC3-II/LC3-I ratio and expression of beclin-1, and reduced expression of P62. Meanwhile, N-MPG expectedly down-regulated autophagy in Ang II-treated podocytes. Rapamycin can enhance the level of autophagy by inhibiting mTOR, and 3-methyladenine (3-MA) can inhibit autophagosome formation through blocking class III phosphatidylinositol 3-kinase. MTT assay exhibited that rapamycin significantly enhanced the cell viability, while 3-MA considerably reduced it in Ang II-treated podocytes. Consequently, this study demonstrated that Ang II could increase TRPC6 induced Ca2+ influx and enhance autophagy through increasing ROS levels in podocytes, and autophagy could protect Ang II-treated podocytes. Improving TRPC6 channels and autophagy may become a new targeted therapy to relieve glomerular damage induced by Ang II.

Resveratrol Attenuates Aß-Induced Early Hippocampal Neuron Excitability Impairment via Recovery of Function of Potassium Channels.

Alzheimer's disease (AD) is an age-related neurodegenerative disease. Amyloid-ß (Aß) is not only the morphological hallmark but also the initiator of the pathology process of AD. As a natural compound found in grapes, resveratrol shows a protective effect on the pathophysiology of AD, but the underlying mechanism is not very clear. This study was to investigate whether resveratrol could attenuate Aß-induced early impairment in hippocampal neuron excitability and the underlying mechanism. The excitability and voltage-gated potassium currents were examined in rat hippocampal CA1 pyramidal neurons by using whole-cell patch-clamp technique. It was found that Aß25-35 increased the excitability of neurons. Resveratrol could reverse the Aß25-35-induced increase in the frequency of repetitive firing and the spike half-width of action potential (AP). Moreover, resveratrol can attenuate Aß25-35-induced decreases in transient potassium channel (I A ) and delay rectifier potassium channel (I K(DR)) of neurons. It was also found that resveratrol could decline the increase of protein kinase A (PKA) and inhibit the activation of PI3K/Akt signaling pathway induced by Aß25-35. The results suggest that resveratrol alleviates Aß25-35-induced dysfunction in hippocampal CA1 pyramidal neurons via recovery of the function of I A and I K(DR) by inhibiting the increase of PKA and the activation of PI3K/Akt signaling pathway.

Leonurine ameliorates cognitive dysfunction via antagonizing excitotoxic glutamate insults and inhibiting autophagy.

BACKGROUND: Chronic cerebral hypoperfusion is related with cognitive deficits in different types of dementia. PURPOSE: In this study, we aimed to investigate the effect and potential mechanisms of leonurine on chronic cerebral hypoperfusion both in vitro and in vivo. STUDY DESIGN: Chronic cerebral hypoperfusion was duplicated by oxygen-glucose deprivation (OGD) in vitro and by ligation of bilateral common carotid arteries (2-VO) in vivo. METHODS: In in vitro study, there were control group, OGD group, OGD+ 100µM leonurin group, and OGD+ 10µM donepezil group. The spontaneous excitatory postsynaptic current amplitude and frequency were recorded. In in vivo study, the chronic cerebral hypoperfusion model was induced by ligated bilateral common carotid arteries. Rats were randomly divided into Sham group, 2-VO group, 2-VO+ 60mg/kg/day leonurine group, and 2-VO+ 4mg/kg/day donepezil group. After three weeks, the Morris water maze and Long-term depression recording were observed. Then N-methyl-D-aspartate receptor-associated proteins and autophagy-associated proteins were detected by Western blot assay. RESULTS: In in vitro experiment, results showed that leonurine could obviously attenuate the spontaneous excitatory postsynaptic current amplitude and frequency on pyramidal neurons. In in vivo experiment, leonurine significantly decreased levels of glutamate and hydrogen peroxide, improved both the cognitive flexibility and the spatial learning and memory abilities. Moreover, leonurine obviously enhanced long-term depression, elevated the ratio of N-methyl-D-aspartate receptor 2A/2B, and decreased the expression of postsynaptic density protein-95. Interestingly, the ratio of LC3II/LC3I and beclin-1 expression were markedly down-regulated by leonurine. CONCLUSION: These findings suggest that leonurine ameliorates cognitive dysfunction at least partly via antagonizing excitotoxic glutamate insults and inhibiting autophagy. Furthermore, it might become a potential drug candidate of chronic cerebral hyperfusion in future.

Autophagy ameliorates cognitive impairment through activation of PVT1 and apoptosis in diabetes mice.

The underlying mechanisms of cognitive impairment in diabetes remain incompletely characterized. Here we show that the autophagic inhibition by 3-methyladenine (3-MA) aggravates cognitive impairment in streptozotocin-induced diabetic mice, including exacerbation of anxiety-like behaviors and aggravation in spatial learning and memory, especially the spatial reversal memory. Further neuronal function identification confirmed that both long term potentiation (LTP) and depotentiation (DPT) were exacerbated by autophagic inhibition in diabetic mice, which indicating impairment of synaptic plasticity. However, no significant change of pair-pulse facilitation (PPF) was recorded in diabetic mice with autophagic suppression compared with the diabetic mice, which indicated that presynaptic function was not affected by autophagic inhibition in diabetes. Subsequent hippocampal neuronal cell death analysis showed that the apoptotic cell death, but not the regulated necrosis, significantly increased in autophagic suppression of diabetic mice. Finally, molecular mechanism that may lead to cell death was identified. The long non-coding RNA PVT1 (plasmacytoma variant translocation 1) expression was analyzed, and data revealed that PVT1 was decreased significantly by 3-MA in diabetes. These findings show that PVT1-mediated autophagy may protect hippocampal neurons from impairment of synaptic plasticity and apoptosis, and then ameliorates cognitive impairment in diabetes. These intriguing findings will help pave the way for exciting functional studies of autophagy in cognitive impairment and diabetes that may alter the existing paradigms.

miR-200 family promotes podocyte differentiation through repression of RSAD2.

Mature podocytes are highly differentiated cells with several characteristic phenotypic features that are involved in the glomerular filtration function. During kidney development, a series of changes of the morphological characteristics and cellular functions may happen in podocytes. The miR-200 family functions in various biological and pathological processes. But the underlying molecular mechanisms of miR-200 family that functions in podocyte differentiation remain poorly understood. Herein is shown that miR-200a, miR-200b and miR-429 are significantly upregulated during the differentiation of podocytes, with highest upregulation of miR-200a. In these cells, restraint of miR-200 family by RNA interference assay revealed a prominent inhibition of cell differentiation. More intriguingly, miR-200 family directly inhibited the radical S-adenosyl methionine domain-containing protein 2 (RASD2) expression. Moreover, further upregulation of RSAD2 combining with restraint of miR-200 family revealed a promotion of podocyte dedifferentiation and proliferation. In addition, the expression of RSAD2 is consistent with that of in vitro podocyte differentiation in prenatal and postnatal mouse kidney, and significantly down-regulated during the kidney development. Together, these findings indicate that miR-200 family may potentially promote podocyte differentiation through repression of RSAD2 expression. Our data also demonstrate a novel role of the antiviral protein RSAD2 as a regulator in cell differentiation.