A glass micropipette vacuum technique of cerebrospinal fluid sampling in C57BL/6 mice / 生理学报

The purpose of this study was to establish a suitable method for extracting cerebrospinal fluid (CSF) from C57BL/6 mice. A patch clamp electrode puller was used to draw a glass micropipette, and a brain stereotaxic device was used to fix the mouse's head at an angle of 135° from the body. Under a stereoscopic microscope, the skin and muscle tissue on the back of the mouse's head were separated, and the dura mater at the cerebellomedullary cistern was exposed. The glass micropipette (with an angle of 20° to 30° from the dura mater) was used to puncture at a point 1 mm inboard of Y-shaped dorsal vertebral artery for CSF sampling. After the first extraction, the glass micropipette was connected with a 1 mL sterile syringe to form a negative pressure device for the second extraction. The results showed that the successful rate of CSF extraction was 83.33% (30/36). Average CSF extraction amount was (7.16 ± 0.43) μL per mouse. In addition, C57BL/6 mice were given intranasally ferric ammonium citrate (FAC) to establish a model of brain iron accumulation, and the CSF extraction technique established in the present study was used for sampling. The results showed that iron content in the CSF from the normal saline control group was not detected, while the iron content in the CSF from FAC-treated group was (76.24 ± 38.53) μmol/L, and the difference was significant. These results suggest that glass micropipette vacuum technique of CSF sampling established in the present study has the advantages of simplicity, high success rate, large extraction volume, and low bleeding rate, and is suitable for the research on C57BL/6 mouse neurological disease models.

Research progress of Rab proteins in neurodegenerative diseases / 生理学报

As a member of the Ras superfamily, Rab proteins are small GTP-binding proteins. In the process of endocytosis of macromolecules and substances delivery between organelles, Rab proteins act on vesicle formation, transport, tethering and fusion by recruiting their effectors, therefore being key regulatory factors in vesicle trafficking. Disturbance of localizations and functions of Rab proteins and their effectors are involved in the pathogenesis of several diseases. This review focuses on the main functions of Rab proteins and their possible roles in the onset and progression of neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, and Huntington's disease.

Altered dopamine metabolism and its role in pathogenesis of Parkinson's disease / 生理学报

Parkinson's disease (PD), one of the most frequent neurodegenerative disorders, is characterized by the selective loss of dopaminergic neurons in the substantia nigra (SN). Genetic vulnerability, aging, environmental insults are believed to contribute to the pathogenesis of PD. However, the cellular and molecular mechanism of dopaminergic neurons degeneration remains incompletely understood. Dopamine (DA) metabolism is a cardinal physiological process in dopaminergic neurons, which is closely related to the loss of dopaminergic neurons in the SN. DA metabolism takes part in several pathological processes of PD neurodegeneration, such as iron metabolism disturbance, α-synuclein mis-folding, endoplasmic reticulum stress, protein degradation dysfunction, neuroinflammatory response, etc. In this review, we will describe altered DA metabolism and its contributions to PD pathogenesis.

Exosomes and their roles in neurodegenerative diseases: from pathogenic, diagnostic and therapeutical perspectives / 生理学报

Exosomes are extracellular membranous vesicles with a diameter of 30-100 nm derived from a variety of eukaryocytes. The cargo of exosomes includes proteins, lipids, nucleic acids, and substances of the cells from which they originate. They can transfer functional cargo to neighboring and distal cells, therefore contributing to intercellular communication in both physiological and pathological processes. In recent years, it was shown that exosomes in several neurodegenerative diseases are closely related to the transmission of disease-related misfolded proteins (such as α-synuclein, tau, amyloid β-protein, etc). These proteins are transported by exosomes, thus promoting the propagation to unaffected cells or areas and accelerating the progression of neurodegenerative diseases. This review focuses on the origin and composition, biological synthesis, secretion, function of exosomes, as well as their roles in the pathogenesis and progression of neurodegenerative diseases. In addition, we also discuss that exosomes can serve as biomarkers and drug delivery vehicles, and play a role in the diagnosis and treatment of neurodegenerative diseases.

The progress of multifunctional envelope-type nano device / 药学学报

The key of gene therapy is to deliver the functional gene to the target tissue in the body. The safe and efficient gene carrier is particularly important in the targeted delivery. Multifunctional envelope-type nano device (MEND), based on concept "Programmed packaging", is a new type of gene carrier system, with high encapsulation efficiency, favourable stability, high transfection efficiency, easy preparation, etc. MEND is designed to control intracellular trafficking as well as the tissue distribution of encapsulated compounds such as nucleic acids/proteins/peptides, permitting them to function at the appropriate location. In this paper, research progresses in MEND are reviewed in accordance with three types of payloads:the small interfering RNA (siRNA), DNA and proteins/peptides in recent years.

GBA mutations and Parkinson's disease / 生理学报

Parkinson's disease (PD) is a common neurodegenerative disease characterized by the degeneration of dopaminergic neurons in the substantia nigra and the intraneuronal Lewy bodies in this area. Genetic mutations in PD pathogenesis have been explored and better understood in recent years. GBA variants are now considered to be the single largest risk factor for PD. Gaucher disease (GD) is a lysosomal storage disorder disease and an inherited deficiency of lysosomal glucocerebrosidase (GCase) arising from mutations in the gene GBA. A group of patients with GD exhibit parkinsonian symptoms, meanwhile, GBA mutations are more frequently observed in patients with PD. These lines of evidence suggest a close relationship between GBA mutations and PD. GBA mutations are associated with an earlier onset age and a distinct cognitive decline in PD. GCase loss-of-function caused by GBA mutations interferes with the degradation of α-synuclein, and α-synuclein pathology in turn inhibits normal GCase function in PD, which forms a vicious cycle. However, the exact mechanisms for this bidirectional pathogenic loop have not to be fully elucidated. In this review, we summarize the current understandings on the potential link between GBA mutations and PD pathogenesis, which may show novel insights into PD etiology and therapeutics.

Regulation of iron metabolism by hypoxia-inducible factors / 生理学报

Hypoxia-inducible factors (HIFs) are central mediators of cellular adaption to hypoxia. The heterodimeric HIF transcription factors consist of HIF-α and HIF-β, that form functional HIFs. Mammals contain HIF-1α, HIF-2α, and HIF-3α. HIFs play a key role in iron metabolism by regulating the expression of iron-related proteins, such as divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1), duodenal cytochrome b (Dcytb), and transferrin receptor (TfR). Hepcidin and iron regulatory proteins (IRPs), the central mediators for systematic and intracellular iron homeostasis, are also regulated by HIFs. In this review, we summarized the regulatory effects of HIFs on iron-related proteins, thus providing insights into the control of HIFs as therapeutic strategies for some iron related disorders.

Glial cells are involved in iron accumulation and degeneration of dopamine neurons in Parkinson's disease / 生理学报

A growing body of evidence suggests that glial cells play an important role in neural development, neural survival, nerve repair and regeneration, synaptic transmission and immune inflammation. As the highest number of cells in the central nervous system, the role of glial cells in Parkinson's disease (PD) has attracted more and more attention. It has been confirmed that nigral iron accumulation contributes to the death of dopamine (DA) neurons in PD. Until now, most researches on nigral iron deposition in PD are focusing on DA neurons, but in fact glial cells in the central nervous system also play an important role in the regulation of iron homeostasis. Therefore, this review describes the role of iron metabolism of glial cells in death of DA neurons in PD, which could provide evidence to reveal the mechanisms underlying nigral iron accumulation of DA neurons in PD and provide the basis for discovering new potential therapeutic targets for PD.

Effect of estrogen on iron metabolism in mammals / 生理学报

Estrogen is a steroid hormone produced mainly by the ovaries. It combines with the nuclear receptors to exert the biological effects influencing the metabolism of body. Elevated levels of estrogen are often associated with altered iron levels in mammals. Furthermore, the findings of estrogen response element (ERE) have demonstrated that estrogen affects iron metabolism directly in peripheral tissues. In this review, we will briefly summarize the effect of estrogen on iron metabolism in mammals, and discuss recent progress in the mechanisms of estrogen on some iron related proteins in order to provide guidance for clinical use of estrogen. Estrogen and iron metabolism are closely related, but the exact regulatory mechanisms still need further exploration.

Advances in the association of ATP-sensitive potassium channels and Parkinson's disease / 生理学报

ATP-sensitive potassium channels (K), as an inward rectifying potassium channel, are widely distributed in many types of tissues. Kare activated by the depletion of ATP level and the increase in oxidative stress in cells. The activity of Kcouples cell metabolism with electrical activity and results in membrane hyperpolarization. Kare ubiquitously distributed in the brain, including substantia nigra, hippocampus, hypothalamus, cerebral cortex, dorsal nucleus of vagus and glial cells, and participate in neuronal excitability, mitochondria homeostasis and neurotransmitter release. Accumulating lines of evidence suggest that Kare the major contributing factors in the pathogenesis of Parkinson's disease (PD). This review discussed the association of Kwith the pathogenic processes of PD by focusing on the roles of Kon the degeneration of dopaminergic neurons, the functions of mitochondria, the firing pattern of dopaminergic neurons in the substantia nigra, the α-synuclein secretion from striatum, and the microglia activation.

An overview on autophagy in neural stem cells / 生理学报

Neural stem cells (NSCs) offer great promise for the treatment of multiple neurodegenerative diseases. However, the survival and differentiation rates of grafted cells in the host brain need to be enhanced. In this regard, understanding of the underlying mechanism of NSCs survival and death is of great importance for the implications of stem cell-based therapeutic application in the treatments of neurological disorders. Autophagy is a conserved proteolytic mechanism required for maintaining cellular homeostasis, which can affect NSCs fate through regulating their biological behaviors, such as survival and proliferation. In this mini-review, we will summarize the effects of autophagy on NSCs fate including survival, apoptosis, proliferation and differentiation, as well as the underlying mechanisms.

Copper (Cu2+) induces degeneration of dopaminergic neurons in the nigrostriatal system of rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To study the effects of intranigral injection of different doses of CuSO4.5H2O on dopaminergic neuron in the nigrostriatal system of rats.</p><p><b>METHODS</b>Wistar rats were divided into four groups, including control group, 10 nmol, 50 nmol and 200 nmol copper injected into left substantia nigra (SN) groups. Seven days after the intranigral injection of copper, dopamine (DA) contents in the striatum (Str) were measured by high performance lipid chromotophotography (HPLC); the density of tyrosine hydroxylase (TH) positive axons in the Str was measured by TH staining method; TH and Caspase-3 mRNA expression in the SN were measured by semi-quantitative RT-PCR. We detected the activity of superoxide dismutase (SOD) in the lesioned midbrain of rats using biochemical methods.</p><p><b>RESULTS</b>DA and its metabolites contents had no significant difference between control group and low dose (10 nmol) copper group. But from 50 nmol copper group, DA contents in the lesioned sides were reduced with the increase in the copper doses injected, showing a significant linear correlation (F = 34.16, P < 0.01). In the 50 nmol copper group, TH positive axons in the Str decreased compared with those of the control and unlesioned sides (F = 121.9, P < 0.01). In the 50 nmol copper group, TH mRNA expression decreased (t = 3.12, P < 0.01) while Caspase-3 mRNA expression increased (t = 8.96, P < 0.01) in the SN compared with the control. SOD activity decreased in the midbrain of rats treated with 50 nmol copper compared with that of the control (t = 2.33, P < 0.01).</p><p><b>CONCLUSION</b>Copper could induce damage of dopaminergic neurons in the SN of rats through destroying antioxidant defenses and promoting apoptosis.</p>

Mitochondria dysfunction was involved in copper-induced toxicity in MES23.5 cells / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To investigate the toxicity of copper on MES23.5 dopaminergic cells and the probable mechanisms involved in this process.</p><p><b>METHODS</b>MES23.5 dopaminergic cells were selected as our experimental model. [3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide] (MTT) assay was used to detect the influence of copper on the cell viability. The semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), Western blotting and the high performance liquid chromatography-electrochemical detection (HPLC-ECD) have been used to detect the tyrosine hydroxlase (TH) mRNA and protein expression and the dopamine content in MES23.5 cells. The flow cytometry have been used to detect the changes of mitochondrial transmembrane potential.</p><p><b>RESULTS</b>100 and 200 mumol/L copper had no effect on the MES23.5 cell viability, whereas 400 and 800 mumol/L of copper could decrease the cell viability (P < 0.01). Treating cells with 200 mumol/L copper for 24 h decreased the TH mRNA expression, the TH expression and the dopamine content compared with the control (P < 0.01, P < 0.01, P < 0.05, respectively). Besides, the mitochondrial transmembrane potential also decreased with the treatment of 200 mumol/L copper for 24 h (P < 0.01).</p><p><b>CONCLUSION</b>Copper could exert the toxic effects on MES23.5 dopaminergic cells and decrease the cell function. The dysfunction of mitochondria may be the mechanism of this toxicity effect.</p>

Isolation of Id1 interaction protein in human prostate cancer / 中华男科学杂志

<p><b>OBJECTIVE</b>To isolate the inhibitor of DNA binding 1 (Id1) interaction protein and to determine the role and action mechanism of Id1 in human prostate cancer.</p><p><b>METHODS</b>The expression vector pET-28a/Id1 was established and used as a bait to prey the interaction protein by pull-down assay.</p><p><b>RESULTS</b>A clear interaction protein band was observed by SDS-PAGE, which was found to be activating transcription factor 3 (ATF3) by Western blotting.</p><p><b>CONCLUSION</b>Id1 may play a role in human prostate cancer by interacting with ATF3.</p>

The protective effect of ginsenoside Rg1 on dopaminergic neurons of substantia in the ovariectomized rat model of Parkinson's disease / 中国应用生理学杂志

<p><b>AIM</b>To investigate the neuroprotective effect of ginsenoside Rg1 on dopaminergic neurons of substantia nigra in ovariectomized rat model of Parkinson's disease and the possible mechanisms.</p><p><b>METHODS</b>Wistar female rats were ovariectomized and treated with vehicle, ginsenoside Rg1 or 17-beta estradiol intracerebroventricularly in the 6-OHDA induced rat model of Parkinson's disease. Immunohistochemistry was used to detect the tyrosine hydroxylase (TH) immunoreactive neurons and the protein expression of Bcl-2. Perls' iron staining was used to determine the changes of iron in substantia nigra (SN).</p><p><b>RESULTS</b>910 Rg1 or 17-beta estradiol treatment could ameliorate the rat's rotational behavior induced by apomorphine. 92) Rg1 or 17-beta estradiol treatment could increase TH immunoreactive neurons in the injured side of SN compared to the 6-OHDA group. (3) Iron staining in the injured side of SN was significantly increased comparing with the contralateral side in the 6-OHDA group. Rg1 or 17-beta estradiol treatment could reverse the increase of iron staining. (4) Both Rg1 and 17-beta estradiol treatment could increase Bcl-2 protein expression in the injured side of SN compared to the 6 OHDA group.</p><p><b>CONCLUSION</b>Ginsenoside Rg1 has estrogen-like activities and has neuroprotective effects on the dopaminergic neurons in the 6-OHDA induced ovariectomyzed(OVX) rat model of Parkinson's disease (PD). This effect may be attributed to attenuating iron overload and anti-apoptosis.</p>

Correlation between iron levels and degeneration of dopaminergic neurons in rat nigrostriatal system during the early 6-OHDA lesions in medial forebrain bundle / 生理学报

In the present study, using fast cyclic voltammetry (FCV), atomic absorption/flame emission spectrophotometry and immunohistochemistry, we investigated the correlation between iron levels and degeneration of dopaminergic neurons in rat nigrostriatal system during the early 6-OHDA lesions in the medial forebrain bundle (MFB). The results showed that 1 d or 3 d after lesions in MFB, there was a 45% or 66% reduction, respectively, in the density of tyrosine hydroxylase (TH) immunoreactive cells in the substantia nigra (SN) of the lesioned side accompanied by an increase in iron staining intensity and iron concentration; while there was no change in dopamine (DA) release in the striatum (Str) of the lesioned side compared with the unlesioned side and the normal rats. There was no difference in the iron staining and concentration of SN and DA release of Str on the lesioned side between one-day group and three-days group. These results suggest that an iron level elevation in SN may be involved at the early stage of degeneration of DA neurons in SN. However, DA release in Str was unchanged due to the immense compensatory mechanism of DA system.

Increased DMT1 expression and iron content in MPTP-treated C57BL/6 mice / 生理学报

Iron plays a key role in Parkinson s disease (PD). To illustrate the mechanism underlying the increase of iron in substantia nigra (SN) in PD, changes of the expression of divalent metal transporter 1 (DMT1) and iron content were examined in SN in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated mice using immunohistochemistry and histochemistry respectively. Following MPTP treatment for 3 d, elevated iron staining was found in SN. A further increase in iron content was observed after 7 d. In these lesioned animals, tyrosine hydroxylase-immunoreactive DA neurons exhibited a decrease in number and morphological changes as well. There were two isoforms of DMT1 expressed in SN of mice. After MPTP treatment, the expression of DMT1 without IRE form increased in either group, whereas DMT1 with IRE form increased only after 7 d of MPTP treatment. These observations suggest that DMT1 is possibly involved in the process of iron accumulation in SN of MPTP-treated mice, which might be responsible for the subsequent death of DA neurons.

Regulation of estrogen and phytoestrogen on the dopaminergic systems of amygdala in rats / 生理学报

In vivo fast cyclic voltammetry (FCV) was used to investigate dopamine (DA) release from amygdala (Amy) of female rats in different phases of estrus cycle, ovaricectomized (OVX) rats and male rats. Tyrosine hydroxylase (TH) immunohistochemistry was employed to measure the numbers of immunoreactive neurons in ventral tegmental area (VTA) of midbrain in the rats. We also observed the effect of intracerebroventricular injection of phytoestrogen-soy isoflavones on DA release from the Amy. The results are as follows: DA release from the Amy of proestrus female rats was apparently higher than that in estrus, metaestrus, diestrus female rats and OVX rats. Amy DA release and the numbers of the TH immunoreactive neurons in VTA showed a significant sex difference. DA release from Amy of female and OVX rats increased significantly within 5 min after i.c.v injection of soy isoflavones, which elicited no effects in male rats. The above-mentioned results suggest that endogenous estrogen may play an important role in regulating the activity of DA neurons in mid-limbic systems, and that soy isoflavones exert an estrogen-like effect on the dopaminergic systems in the Amy.

Differential role of estrogen in dopamine metabolism in the amygdala and striatum of female rats / 生理学报

To study the effects of estrogen on the contents of dopamine (DA) and its metabolites in the amygdala (Amy) and striatum (Str) of rats, high performance liquid chromatography (HPLC) was used to measure the contents of DA and its metabolites in untreated ovariectomized (OVX) rats and OVX rats treated with estrogen. The contents of DA and its metabolites in Amy but not Str were significantly higher when the OVX rats were treated with a high dose of estradiol benzoate (EB). The turnover rate of DA in Amy of the OVX rats was lower than that of normal and EB-treated OVX rats. The turnover rate of DA in Amy was about twice as high as in the Str, while the content of DA in Amy was only one-sixth of that in the Str. The results obtained imply that serum concentration of estrogen is one of the important factors which affect the DA metabolism and content in the Amy of female rats, while the Str is not influenced by estrogen.