Peripheral benzodiazepine receptor TSPO needs to be reconsidered before using as a drug target for a pigmentary disorder.

The peripheral benzodiazepine receptor (TSPO/PBR) is highly conserved among different species but with perplexing biochemical functions. Multiple ligands of TSPO show commendable regulatory activities in lots of biological functions, such as neuro-protection, cholesterol transport, and so on. These researches support that TSPO may be a potential target for disease treatment and drug development. Previous studies have shown that its ligands benzodiazepines show a satisfactory effect on melanogenic promotion. However, the potential application of TSPO in drug development for pigmentary disorder needs further investigation. In this study, we confirmed the melanogenesis induction of TSPO ligand, Ro5-4864 in mouse melanoma cell lines, human skin tissue, and zebrafish embryos by inducing melanin synthesis and melanosome transport. Molecular genetics and pharmacological studies showed that TSPO deficiency did not affect melanin production in B16F10 cells and zebrafish embryos, nor did it affect the melanin promotion effect of Ro5-4864. Whether or not TSPO exists, the expression of lots of melanogenesis-related proteins, such as TYR, TRP-1, DCT, Mlph, and Rab27 was upregulated with the Ro5-4864 administration. These results indicated that Ro5-4864 induces melanogenesis in a TSPO-independent manner, which is inconsistent with previous research. This research is a reminder that we need to be very careful during target validation in drug development.

Can Photothermal Post-Operative Cancer Treatment Be Induced by a Thermal Trigger?

One of the current challenges in the post-operative treatment of breast cancer is to develop a local therapeutic vector for preventing recurrence and metastasis. Herein, we develop a core-shell fibrous scaffold comprising phase-change materials and photothermal/chemotherapy agents, as a thermal trigger for programmable-response drug release and synergistic treatment. The scaffold is obtained by in situ growth of a zeolitic imidazolate framework-8 (ZIF-8) shell on the surface of poly(butylene succinate)/lauric acid (PBS/LA) phase-change fibers (PCFs) to create PCF@ZIF-8. After optimizing the core-shell and phase transition behavior, gold nanorods (GNRs) and doxorubicin hydrochloride (DOX) co-loaded PCF@ZIF-8 scaffolds were shown to significantly enhance in vitro and in vivo anticancer efficacy. In a healthy tissue microenvironment at pH 7.4, the ZIF-8 shell ensures the sustained release of DOX. If the tumor recurs, the acidic microenvironment induces the decomposition of the ZIF-8 shell. Under the second near-infrared (NIR-II) laser treatment, GNR-induced thermal not only directly destroys the relapsed tumor cells but also accelerates DOX release by inducing the phase transition of LA. Our study sheds light on a well-designed programmable-response trigger, which provides a promising strategy for post-operative recurrence prevention of cancer.

Zebrafish Model for Screening Antiatherosclerosis Drugs.

This study is aimed at establishing a zebrafish model of AS, which can be applied for high-throughput screening anti-AS drugs. A zebrafish AS model was induced by high cholesterol diet (HCD) and lipopolysaccharide (LPS). In the early stage of modeling, HCD induced zebrafish to show some early symptoms similar to human AS, mainly cholesterol accumulation, vascular inflammation, lipid metabolism disorder, and oxidative stress. In addition to lipid metabolism disorders, LPS also induced the same symptoms. And when HCD and LPS exist at the same time, these AS symptoms in zebrafish become more severe. When the modeling time reached 45 days, HCD and LPS induce the formation of plaques in zebrafish blood vessels, and these plaques contain fibrous tissue and lipids, which are similar to human AS plaques. We also evaluated the efficacy of some anti-AS drugs (atorvastatin, aspirin, and vitamin C) through these zebrafish AS models. The results found that atorvastatin can significantly reduce the symptoms of AS induced by HCD and LPS, and aspirin and vitamins can significantly reduce the symptoms of AS induced by LPS. It is feasible to use zebrafish to establish an AS model, and the zebrafish AS model can be used for high-throughput screening of anti-AS drugs.

Altered expression of Dscam in temporal lobe tissue from human and experimental animals.

Down syndrome cell adhesion molecule (Dscam) is a neural adhesion molecule that plays an essential role in the establishment of neural circuits. Considerable evidence suggests that Dscam is required for axon guidance and dendritic arborization. Our aim was to investigate the expression of Dscam in the temporal lobes of patients with intractable epilepsy (IE) and of experimental animals. In this study, we used immunohistochemistry, immunofluorescence, and western blotting to examine Dscam expression in thirty-five surgical samples from brains of IE patients and 15 control brain samples. We also measured the levels of Dscam during the entire epileptic process in a rat model of temporal lobe epilepsy. Dscam expression in IE patients was significantly higher compared with that in the controls. In addition, Dscam was also highly expressed in the rat brain during the different phases of the epileptic process. It is the first time to find abnormal expression of Dscam in the brain tissues in patients with IE. And this finding provides an experimental evidence for the study of neuronal circuit remodeling and synaptic plasticity in IE, furthermore, our results also suggest that Dscam may be involved in the generation and the development of IE.

Anti-inflammatory alkaloids from the stems of Picrasma quassioides BENNET.

During further chemical and biological investigations of Picrasma quassioides BENNET, four new bis-ß-carboline alkaloids, quassidines E-H (1-4), and three new ß-carboline alkaloids, canthin-16-one-14-butyric acid (5), 3-(1,1-dimethoxylmethyl)-ß-carboline (6), and 6,12-dimethoxy-3-formyl-ß-carboline (7), were isolated from its anti-inflammatory CHCl(3)-soluble fraction. Structures of new compounds were elucidated and characterized by MS and NMR analysis. A plausible biogenetic pathway for quassidine E (1), the first bis-ß-carboline alkaloid in which a canthin-6-one moiety and a ß-carboline moiety were connected together by a single carbon-carbon bond from the nature, was proposed. Quassidines E-G (1-3) showed potent inhibitory activity on the production of nitric oxide (NO), tumor necrosis factor α (TNF-α), or interleukin 6 (IL-6) in mouse monocyte-macrophage RAW264.7 cells stimulated by lipopolysaccharide (LPS). Analysis of anti-inflammatory activity of all ß-carboline and bis-ß-carboline alkaloids from P. quassioides showed that the carbonyl groups or double carbon-carbon bonds at C-14 for ß-carbolines and C-14' for bis-ß-carbolines were bioactive groups for their in vitro anti-inflammatory activity. Structure-activity relationship of these compounds on inhibitory activity of the three inflammatory cytokines was discussed.

Downregulation of gephyrin in temporal lobe epilepsy neurons in humans and a rat model.

Gephyrin, which is a postsynaptic scaffolding protein participated in clustering GABA(A) receptors at inhibitory synapses, has been reported to be involved in temporal lobe epilepsy (TLE) recently. Here, we investigate gephyrin protein expression in the temporal lobe epileptic foci in epileptic patients and experimental animals in order to explore the probable relationship between gephyrin expression and TLE. Using immunohistochemistry, immunofluorescence, and western blot analysis, gephyrin expression was examined in 30 human temporal neocortex samples from patients who underwent surgery to treat drug-refractory TLE and 10 histological normal temporal neocortex from the controls. Meanwhile, we investigated the gephyrin expression in the hippocampus and adjacent neocortex from experimental rats on 24 h, 48 h, 1 week, 2 weeks, 1 month, and 2 months postseizure and from control rats. Gephyrin protein was mainly expressed in the membrane and cytoplasm of neurons in temporal lobe epileptic foci in humans and experimental rats. Gephyrin expression was significantly lower in the temporal neocortex of TLE patients compared to the controls. In experimental rats, the expression of gephyrin in temporal lobe was downregulated in epileptic groups compared to the control group. Gephyrin expression gradually decreased during the acute period and the latent period, but then began to increase below the levels seen in controls during the chronic phase. Our findings suggest that gephyrin may be involved in the development of TLE.

Abnormal expression of netrin-G2 in temporal lobe epilepsy neurons in humans and a rat model.

The membrane-bound axon guidance molecule netrin-g2 is preferentially expressed in the central nervous system and plays a role in synapse formation and maintenance. Using immunohistochemistry, immunofluorescence, and Western blotting, we investigated the possible correlation between netrin-g2 expression and intractable epilepsy (IE) using surgical samples from epilepsy patients. We used 35 samples of temporal neocortex from patients undergoing surgery for drug-refractory epilepsy and 15 autopsy samples from individuals who died in traffic accidents (i.e., samples of normal human brain). We also examined netrin-g2 expression in the hippocampus and adjacent cortex of rats with temporal lobe epilepsy (lithium chloride-pilocarpine model). Netrin-g2 was expressed in the membrane and cytoplasm of neurons from control specimens, and expression was higher in tissue from patients with intractable epilepsy. Western blotting of rat brain tissue showed that netrin-g2 was upregulated starting at 6h after kindling. Maximal expression was seen around 2 days, and relatively high expression was maintained until 30 days. Expression then returned to normal levels at 60 days, which was consistent with the immunohistochemical and immunofluorescence results. These data implicate netrin-g2 in the pathophysiology of epilepsy and are consistent with the hypothesis that this protein may participate in the abnormal development of synapses and in neuron migration.

Abnormal expression and spatiotemporal change of Slit2 in neurons and astrocytes in temporal lobe epileptic foci: A study of epileptic patients and experimental animals.

Repellent guidance molecules provide targeting information to outgrowing axons along predetermined pathways during development. These molecules may also play a role in synaptic reorganization in the adult brain and thereby promote epileptogenesis. Our aim was to investigate the expression of Slit2, one of repellent guidance molecules, in temporal lobe epileptic foci from epileptic patients and experimental animals. Thirty-five temporal neocortex tissue samples from patients with intractable temporal lobe epilepsy (TLE) and fifteen histological normal temporal lobes from controls were selected. Fifty-four Sprague-Dawley rats were divided randomly into six groups, including five groups with epilepsy induced by lithium-pilocarpine administration and one control group. Temporal lobe tissue samples were taken from rats at 1, 7, 14, 30, and 60 days post-seizure and from controls. Expression of Slit2 was assessed by immunohistochemistry, immunofluorescence, and Western blot analysis. Slit2 was mainly expressed in neurons in human controls and in both neurons and astrocytes in TLE patients. Slit2 expression was significantly higher in TLE patients as compared with the controls. Slit2-positive cells were mainly neurons in the rat temporal lobe tissues of the control group, the acute period group, and the latent period group, while the Slit2-positive cells were mainly astrocytes in chronic phase. Compared with controls, Slit2 expression in animals in the TLE group gradually decreased from days 1 to 14 post-seizure, but then increased over the levels seen in controls, to peak levels at days 30 and 60. These results suggest that Slit2 may play an important role in the pathogenesis of TLE.

Tetranectin is a potential biomarker in cerebrospinal fluid and serum of patients with epilepsy.

BACKGROUND: Tetranectin (TN) is a plasminogen kringle 4 binding protein and regulates fibrinolysis and proteolytic processes via binding to plasminogen. A previous proteomics study identified TN in the cerebrospinal fluid (CSF) of epileptic patients but not in healthy controls. We determined the concentrations of TN in CSF and serum of epileptic patients to evaluate the changes in TN levels after epileptic attack. METHODS: We detected TN in the CSF and serum of 64 epileptic patients and 26 healthy subjects using sandwich enzyme-linked immunosorbent assays. RESULTS: Compared with the control group, CSF-TN levels increased in epileptic patients while serum-TN levels decreased. These differences were statistically significant. The decrease of serum-TN in patients with drug-refractory epilepsy was the most striking. CONCLUSION: CSF-TN and serum-TN are potential biomarkers in epilepsy and drug-refractory epilepsy and would be useful for diagnosis.