Cytisine-like alkaloids from the seeds of Ormosia hosiei Hemsl. et Wils.

Two new cytisine-like alkaloids, hositisines C (1) and D (2), were isolated from the seeds of Ormosia hosiei along with four known compounds, (-)-tinctorine (3), ß-adenosine (4), 2'-deoxyadenosine (5), and 7, 2', 4'-trihydroxy-5-methoxyisoflavanone (6). Their structures were established using extensive spectroscopic techniques (UV, IR, CD, HRESIMS, 1 D and 2 D NMR). In the cytotoxic activity, compounds 1-3 and 5-fluorouracil (positive control) displayed inhibitory effects against HepG2 cells, exhibiting IC50 values of 44.52 ± 7.83 µM, 111.49 ± 12.76 µM, 127.72 ± 18.67 µM, and 16.37 ± 3.82 µM.

Implantation of regenerative complexes in traumatic brain injury canine models enhances the reconstruction of neural networks and motor function recovery.

Rationale: The combination of medical and tissue engineering in neural regeneration studies is a promising field. Collagen, silk fibroin and seed cells are suitable options and have been widely used in the repair of spinal cord injury. In this study, we aimed to determine whether the implantation of a complex fabricated with collagen/silk fibroin (SF) and the human umbilical cord mesenchymal stem cells (hUCMSCs) can promote cerebral cortex repair and motor functional recovery in a canine model of traumatic brain injury (TBI). Methods: A porous scaffold was fabricated with cross-linked collagen and SF. Its physical properties and degeneration rate were measured. The scaffolds were co-cultured with hUCMSCs after which an implantable complex was formed. After complex implantation to a canine model of TBI, the motor evoked potential (MEP) and magnetic resonance imaging (MRI) were used to evaluate the integrity of the cerebral cortex. The neurologic score, motion capture, surface electromyography (sEMG), and vertical ground reaction force (vGRF) were measured in the analysis of motor functions. In vitro analysis of inflammation levels was performed by Elisa while immunohistochemistry was used in track the fate of hUCMSCs. In situ hybridization, transmission electron microscope, and immunofluorescence were used to assess neural and vascular regeneration. Results: Favorable physical properties, suitable degradation rate, and biocompatibility were observed in the collagen/SF scaffolds. The group with complex implantation exhibited the best cerebral cortex integrity and motor functions. The implantation also led to the regeneration of more blood vessels and nerve fibers, less glial fibers, and inflammatory factors. Conclusion: Implantation of this complex enhanced therapy in traumatic brain injury (TBI) through structural repair and functional recovery. These effects exhibit the translational prospects for the clinical application of this complex.

Hositisines A and B, new alkaloids from the stems of Ormosia hosiei Hemsl. et Wils.

Two new alkaloids, named hositisines A (1) and B (2), with two known alkaloids (3 and 4) were isolated from the stems of Ormosia hosiei Hemsl. et Wils. Their structures were confirmed by UV, HRESIMS, NMR spectra. The absolute configurations of 1 and 2 were determined by quantum ECD calculation and ECD, respectively. Compounds 1-3 could significantly reduce the LDH release at the concentration 50 µM, which showed they could strongly protect the PC12 cells exposed to oxygen and glucose deprivation/reoxygenation (OGD/R) injury.

Collagen/heparan sulfate porous scaffolds loaded with neural stem cells improve neurological function in a rat model of traumatic brain injury.

One reason for the poor therapeutic effects of stem cell transplantation in traumatic brain injury is that exogenous neural stem cells cannot effectively migrate to the local injury site, resulting in poor adhesion and proliferation of neural stem cells at the injured area. To enhance the targeted delivery of exogenous stem cells to the injury site, cell therapy combined with neural tissue engineering technology is expected to become a new strategy for treating traumatic brain injury. Collagen/heparan sulfate porous scaffolds, prepared using a freeze-drying method, have stable physical and chemical properties. These scaffolds also have good cell biocompatibility because of their high porosity, which is suitable for the proliferation and migration of neural stem cells. In the present study, collagen/heparan sulfate porous scaffolds loaded with neural stem cells were used to treat a rat model of traumatic brain injury, which was established using the controlled cortical impact method. At 2 months after the implantation of collagen/heparan sulfate porous scaffolds loaded with neural stem cells, there was significantly improved regeneration of neurons, nerve fibers, synapses, and myelin sheaths in the injured brain tissue. Furthermore, brain edema and cell apoptosis were significantly reduced, and rat motor and cognitive functions were markedly recovered. These findings suggest that the novel collagen/heparan sulfate porous scaffold loaded with neural stem cells can improve neurological function in a rat model of traumatic brain injury. This study was approved by the Institutional Ethics Committee of Characteristic Medical Center of Chinese People's Armed Police Force, China (approval No. 2017-0007.2) on February 10, 2019.

Collagen/heparin scaffold combined with vascular endothelial growth factor promotes the repair of neurological function in rats with traumatic brain injury.

The objective of this study was to evaluate the therapy effects of a novel biological scaffold containing heparin, collagen and vascular endothelial growth factor (VEGF) in treating traumatic brain injury (TBI). In our research, a functional composite scaffold constituted by collagen, heparin and vascular endothelial growth factor was used to stimulate angiogenesis and improve nerve-tissue regeneration in a rat model of TBI. The composite scaffold possessed excellent mechanical properties and good porosity, and could effectively control the release rate of VEGF. Motor and cognitive functions such as motor evoked potential, Morris water maze test and modified neurological severity score were evidently improved after the scaffold was grafted onto the injury site in the rat TBI model. There was clearly improved restoration of damaged nerve tissue at the injured site. Furthermore, brain edema and inflammatory reactions were significantly alleviated. Newly formed neurons with associated synaptic structures, nerve fibers, myelin sheaths and functional angiogenesis with intact endothelium at the injury site were observed. In conclusion, our data revealed that the collagen/heparin scaffold combined with VEGF could create excellent microenvironment stimuli for damaged nerve-tissue regeneration, providing a potential strategy for treating TBI.

Cascade Claisen and Meinwald Rearrangement for One-Pot Divergent Synthesis of Benzofurans and 2H-Chromenes.

A new cascade approach has been developed for the one-pot four-step divergent synthesis of polysubstituted benzofurans and 2H-chromenes, featuring a novel cascade aromatic Claisen rearrangement/Meinwald rearrangement/dehydrative or oxidative cyclization. This new method was demonstrated with 39 examples tolerating different substitutions at an epoxide, allylic ether, and aromatic ring, and we showcased its utility with the first total synthesis of natural product liparacid A in seven steps.

Collagen scaffold combined with human umbilical cord-mesenchymal stem cells transplantation for acute complete spinal cord injury.

Currently, there is no effective strategy to promote functional recovery after a spinal cord injury. Collagen scaffolds can not only provide support and guidance for axonal regeneration, but can also serve as a bridge for nerve regeneration at the injury site. They can additionally be used as carriers to retain mesenchymal stem cells at the injury site to enhance their effectiveness. Hence, we hypothesized that transplanting human umbilical cord-mesenchymal stem cells on collagen scaffolds would enhance healing following acute complete spinal cord injury. Here, we test this hypothesis through animal studies and a phase I clinical trial. (1) Animal experiments: Models of completely transected spinal cord injury were established in rats and canines by microsurgery. Mesenchymal stem cells derived from neonatal umbilical cord tissue were adsorbed onto collagen scaffolds and surgically implanted at the injury site in rats and canines; the animals were observed after 1 week-6 months. The transplantation resulted in increased motor scores, enhanced amplitude and shortened latency of the motor evoked potential, and reduced injury area as measured by magnetic resonance imaging. (2) Phase I clinical trial: Forty patients with acute complete cervical injuries were enrolled at the Characteristic Medical Center of Chinese People's Armed Police Force and divided into two groups. The treatment group (n = 20) received collagen scaffolds loaded with mesenchymal stem cells derived from neonatal umbilical cord tissues; the control group (n = 20) did not receive the stem-cell loaded collagen implant. All patients were followed for 12 months. In the treatment group, the American Spinal Injury Association scores and activities of daily life scores were increased, bowel and urinary functions were recovered, and residual urine volume was reduced compared with the pre-treatment baseline. Furthermore, magnetic resonance imaging showed that new nerve fiber connections were formed, and diffusion tensor imaging showed that electrophysiological activity was recovered after the treatment. No serious complication was observed during follow-up. In contrast, the neurological functions of the patients in the control group were not improved over the follow-up period. The above data preliminarily demonstrate that the transplantation of human umbilical cord-mesenchymal stem cells on a collagen scaffold can promote the recovery of neurological function after acute spinal cord injury. In the future, these results need to be confirmed in a multicenter, randomized controlled clinical trial with a larger sample size. The clinical trial was approved by the Ethics Committee of the Characteristic Medical Center of Chinese People's Armed Police Force on February 3, 2016 (approval No. PJHEC-2016-A8). All animal experiments were approved by the Ethics Committee of the Characteristic Medical Center of Chinese People's Armed Police Force on May 20, 2015 (approval No. PJHEC-2015-D5).

Protective effect of BMSCs-derived exosomes mediated by BDNF on TBI via miR-216a-5p.

BACKGROUND Transplantation of exosomes derived from mesenchymal stem cells (MSCs-Exo) can improve the recovery of neurological function in rats after traumatic brain injury (TBI). We tested a new hypothesis that BDNF-mediated MSCs-Exo could effectively promote functional recovery and neurogenesis of rats after TBI. MATERIAL AND METHOD BMSCs of rats were extracted by whole bone marrow culture, BDNF was added to BMSCs for intervention, supernatant was collected, and exosomes were separated and purified by hypercentrifugation. Exosomes were identified by WB, TEM and particle size analysis and subsequently used in cell and animal experiments. We investigated the recovery of sensorimotor function and spatial learning ability, inflammation inhibition and neuron regeneration in rats after TBI. RESULTS Compared with group MSCs-Exo, group BDNF-mediated MSCs-Exo showed better effects in promoting the recovery of sensorimotor function and spatial learning ability. BDNF-mediated MSCs-Exo successfully inhibited inflammation and promoted neuronal regeneration in vivo and in vitro. We further analyzed miRNA in BDNF-mediated MSCs-Exo and MSCs-Exo, and found that the expression of miR-216a-5p in BDNF-mediated MSCs-Exo was significantly higher than that in MSCs-Exo by qRT-PCR. Rescue experiment indicated that miR-216a-5p has a similar function to BDNF-mediated MSCs-Exo. CONCLUSIONS In conclusion, we found that BDNF-mediated MSCs-Exo can better promote neurogenesis and inhibit apoptosis than MSCs-Exo in rats after TBI, and the mechanism may be related to the high expression of miR-216a-5p.

Chemical constituents from the bark of bauhinia purpurea and their NO inhibitory activities.

Phytochemical studies led to the isolation of a new phenylpropanoid glucoside, named purpuroside (1), along with eight known compounds (2-9) from the bark of Bauhinia purpurea. The structure of the new compound was elucidated on the basis of its spectroscopic data. The absolute configuration of compound 2 was verified by X-ray diffraction analysis. Compounds 1, 2, 7, 8, and 9 inhibited NO production in mouse peritoneal macrophages with IC50 values from 35.5 to 63.0 µM.

Three-dimensional bioprinting collagen/silk fibroin scaffold combined with neural stem cells promotes nerve regeneration after spinal cord injury.

Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord. Indeed, cell transplantation and bio-scaffold implantation are considered to be effective methods for neural regeneration. This study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3D-CF) with cavities that simulate the anatomy of normal spinal cord. This scaffold allows cell growth in vitro and in vivo. To observe the effects of combined transplantation of neural stem cells (NSCs) and 3D-CF on the repair of spinal cord injury. Forty Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed), spinal cord injury (transection injury of T10 spinal cord without any transplantation), 3D-CF (3D scaffold was transplanted into the local injured cavity), and 3D-CF + NSCs (3D scaffold co-cultured with NSCs was transplanted into the local injured cavity. Neuroelectrophysiology, imaging, hematoxylin-eosin staining, argentaffin staining, immunofluorescence staining, and western blot assay were performed. Apart from the sham group, neurological scores were significantly higher in the 3D-CF + NSCs group compared with other groups. Moreover, latency of the 3D-CF + NSCs group was significantly reduced, while the amplitude was significantly increased in motor evoked potential tests. The results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3D-CF + NSCs group. Moreover, regenerative axons were abundant and glial scarring was reduced in the 3D-CF + NSCs group compared with other groups. These results confirm that implantation of 3D-CF combined with NSCs can promote the repair of injured spinal cord. This study was approved by the Institutional Animal Care and Use Committee of People's Armed Police Force Medical Center in 2017 (approval No. 2017-0007.2).

Insulin-like growth factor-1 enhances neuroprotective effects of neural stem cell exosomes after spinal cord injury via an miR-219a-2-3p/YY1 mechanism.

Spinal cord injury (SCI) remains the most common cause of paralysis, and there are no effective therapies for SCI patients. Neural stem cell (NSC)-derived exosomes can attenuate apoptosis and neuroinflammation after traumatic spinal cord injury, but the mechanisms underlying these effects remain unclear. Here, we examined the efficacy of miRNAs isolated from exosomes as treatments for SCI and characterized their mechanisms of action. Furthermore, we evaluated the effects of exosomes formed in the presence of insulin growth factor-1 (IFG-1, IGF-Exo), which promotes neural proliferation and regeneration, as well as normal exosomes (Nor-Exo) and compared control and H2O2-treated groups both invitro and invivo. Using microRNA sequencing and qRT-PCR, we identified miR-219a-2-3p, levels of which were higher in the IGF-Exo than Nor-Exo group and played crucial anti-inflammatory and anti-apoptosis roles. Additional experiments revealed that IGF-Exo inhibits YY1 expression through up-regulation of miR-219a-2-3p. This in turn inhibits the NF-κB pathway, partly inhibiting neuroinflammation and promoting the neuroprotective effects after SCI.

Concise and Gram-Scale Total Synthesis of Lansiumamides A and B and Alatamide.

The total synthesis of potent anti-obesity lansiumamide B was accomplished in four steps using commercially available materials. The synthetic strategy, featured with copper-catalyzed Buchwald coupling, is concise, convergent, practical and can be carried out on a one-gram scale. This approach could give either Z- or E-configured enamide moiety in natural products with absolute stereocontrol and was applied in the total synthesis of natural products.

Chemical Constituents and Biological Activity Profiles on Pleione (Orchidaceae).

Pleione (Orchidaceae) is not only famous for the ornamental value in Europe because of its special color, but also endemic in Southern Asia for its use in traditional medicine. A great deal of research about its secondary metabolites and biological activities has been done on only three of 30 species of Pleione. Up to now, 183 chemical compounds, such as phenanthrenes, bibenzyls, glucosyloxybenzyl succinate derivatives, flavonoids, lignans, terpenoids, etc., have been obtained from Pleione. These compounds have been demonstrated to play a significant role in anti-tumor, anti-neurodegenerative and anti-inflammatory biological activities and improve immunity. In order to further develop the drugs and utilize the plants, the chemical structural analysis and biological activities of Pleione are summarized in this review.

[Effects of Exendin-4 on the differentiation of neural stem cells from subventricular zone of adult mice in vitro].

OBJECTIVE: To study the effect of exendin-4(Ex-4) on the differentiation of neural stem cells(NSCs) in adult mouse subventricular zone(SVZ)and its mechanism . METHODS: NSCs in the SVZ were derived from 5-week C57BL/6J mice and the expression of nestin was detected by immunofluorescence. The cell morphology was observed after the cells treatmed with 100 nmol/L Ex-4 for 14 days.The expressions of nestin and glucagon-like peptide-1 receptor (GLP-1R) were detected by immunofluorescence. GLP-1R was knocked down by using shRNA and the study was divided into four groups: control group, Ex-4 group, GLP-1R knockdown group, GLP-1R knockdown + Ex-4 group. After treatment with 100 nmol/L Ex-4 for 14 d, ß-tublin III and glial fibrillary acidic protein (GFAP) were labeled by immunofluorescence and then the proportion of ß-tublin III positive cells were counted. Western blot was used to detect the activation of cAMP-response element binding protein (CREB) in NSCs. In order to further study the effects of Ex-4 on mitogen-activated protein kinase(MAPK) and phosphatidylinositol 3-hydroxy kinase (PI3K) pathways, the cells were pretreated with MAPK inhibitor U0126 at a concentration of 0.07 µmol/L for 30 min or PI3K inhibitor LY294002 at 50 µmol for 2 h, respectively. The study was divided into six groups: control group, Ex-4 group, U0126 group, U0126 + Ex-4 group, LY294002 group, LY294002 + Ex-4 group. The activation of CREB in each group was detected by Western blot. The experiment was repeated three times independently. RESULTS: NSCs were successfully extracted from SVZ of C57BL/6J mice. Immunofluorescence showed that nestin and GLP-1R were positive in NSCs. Compared with the control group, the proportion of neurons differentiated from Ex-4 group was higher. The percentage of neurons in GLP-1R knockdown + Ex-4 group was basically the same as that in control group (P＜0.01). The positive cells of beta-tublin III showed positive activation of GLP-1R and CREB. Western blot showed that CREB was significantly activated in the Ex-4 group, and knockdown of GLP-1R abolished its activation (P＜0.01). U0126 did not affect Ex-4-mediated CERB activation, and LY294002 significantly reduced Ex-4-mediated CREB activation (P＜0.01). CONCLUSION: Ex-4 promotes the differentiation of NSCs into neurons in SVZ of adult mice through GLP-1R receptor, which may be achieved through PI3K/CREB pathway.

Neurological functional evaluation based on accurate motions in big animals with traumatic brain injury.

An accurate and effective neurological evaluation is indispensable in the treatment and rehabilitation of traumatic brain injury. However, most of the existing evaluation methods in basic research and clinical practice are not objective or intuitive for assessing the neurological function of big animals, and are also difficult to use to qualify the extent of damage and recovery. In the present study, we established a big animal model of traumatic brain injury by impacting the cortical motor region of beagles. At 2 weeks after successful modeling, we detected neurological deficiencies in the animal model using a series of techniques, including three-dimensional motion capture, electromyogram and ground reaction force. These novel technologies may play an increasingly important role in the field of traumatic brain injury diagnosis and rehabilitation in the future. The experimental protocol was approved by the Animal Care and Use Committee of Logistics University of People's Armed Police Force (approval No. 2017-0006.2).

Exendin-4 promotes actin cytoskeleton rearrangement and protects cells from Nogo-A-Δ20 mediated spreading inhibition and growth cone collapse by down-regulating RhoA expression and activation via the PI3K pathway.

Exendin-4 is a protein of the GLP-1 family currently used to treat diabetes. Recently, a greater number of biological properties have been associated with the GLP-1 family. Our data shows that exendin-4 treatment significantly increases the cytoskeleton rearrangement, which leads to an increasingly differentiated phenotype and reduced cell migration. We also found that exendin-4 could prevent SH-SY5Y and PC12 cells from Nogo-A-Δ20 mediated spreading inhibition and neurite collapse. Western blot analysis indicated that exendin-4 treatment both reduced the expression and activation of RhoA via the PI3K signaling pathway. These data suggest that exendin-4 may protect nerve regeneration by preventing the inhibition of Nogo-A via down-regulating RhoA expression and activation.

Synthesis and Fungicidal Activity of Lansiumamide A and B and Their Derivatives.

A efficient 2-step protocol has been applied for the synthesis of Lansiumamide B (N-methyl-N-cis-styryl-cinnamamide, 2) derivatives by various substitution on the amide nitrogen with alkyl, allyl, propargyl, benzyl or ester groups. The structures of nine new compounds were characterized by HRMS, ¹H NMR, and 13C NMR spectra. These compounds were tested in vitro against 10 strains of phytopathogenic fungi and showed a wide antifungal spectrum. The relationship between different substituents on the amide nitrogen and antifungal activity of Lansiumamide B derivatives were compared and analyzed. The result indicates that the length and steric hindrance of N-substitution have a significant impact on biological activities. It is noteworthy that the methyl or ethyl substituent on the amide nitrogen is critical for the antifungal activities.