Human Umbilical Cord Mesenchymal Stem Cells Improve Locomotor Function in Parkinson’s Disease Mouse Model Through Regulating Intestinal Microorganisms

Parkinson’s disease (PD) is a progressive neurological disorder characterized by loss of neurons that synthesize dopamine, and subsequent impaired movement. Umbilical cord mesenchymal stem cells (UC-MSCs) exerted neuroprotection effects in a rodent model of PD. However, the mechanism underlying UC-MSC-generated neuroprotection was not fully elucidated. In the present study, we found that intranasal administration of UC-MSCs significantly alleviated locomotor deficits and rescued dopaminergic neurons by inhibiting neuroinflammation in a PD mouse model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, a toxic agent which selectively destroys nigrostriatal neurons but does not affect dopaminergic neurons elsewhere). Furthermore, UC-MSC treatment altered gut microbiota composition characterized by decreased phylum Proteobacteria, class Gammaproteobacteria, family Enterobacteriaceae, and genus Escherichia-Shigella. In addition, the neurotransmitter dopamine in the striatum and 5-hydroxytryptamine in the colon were also modulated by UC-MSCs. Meanwhile, UC-MSCs significantly maintained intestinal goblet cells, which secrete mucus as a mechanical barrier against pathogens. Furthermore, UC-MSCs alleviate the level of TNF-α and IL-6 as well as the conversion of NF-κB expression in the colon, indicating that inflammatory responses were blocked by UC-MSCs. PICRUSt showed that some pathways including bacterial invasion of epithelial cells, fluorobenzoate degradation, and pathogenic Escherichia coli infection were significantly reversed by UC-MSCs. These data suggest that the beneficial effects were detected following UC-MSC intranasal transplantation in MPTP-treated mice. There is a possible neuroprotective role of UC-MSCs in MPTP-induced PD mice by cross talk between the brain and gut.

An Optimal Combination of Chemically Pure Compounds from Salvia Miltiorrhiza for Inhibiting Cell Proliferation

OBJECTIVE

Salvia Miltiorrhiza (SM) is a traditional Chinese medicine used clinically to treat cardiovascular diseases including atherosclerosis and myocardial infarction. Its therapeutic effect has been confirmed by many clinical and pharmacological studies. However, the optimal formulation of active ingredients in SM for treating cardiovascular diseases remains unclear. In this study, we determined the ratio of the optimal compatibility of SM ingredients DSS, Sal-A, Sal-B, and PAL (SABP）with a uniform and orthogonal optimized experimental design. In addition, we determined the anti-oxidation effect of SABP using Adventitial Fibroblasts (AFs).

METHODS

By using a combination of uniform and orthogonal designs, we determined the optimal formulation of aqueous extract from SM. MTT assay was used to determine the inhibitory effects of these 4 components of SM on the AFs, which were isolated and cultured from aorta. The reactive oxygen species (ROS) production in AFs was compared before and after SABP treatment.

RESULTS

The optimal formulation of these 4 aqueous extracts from SM were 150︰7︰300︰500, and their concentrations were S(1.5×10-4 mol/L), A(7×10-6 mol/L), B(3×10-4 mol/L), and P(5×10-4 mol/L). There were some synergies between these 4 components. Moreover, SABP decreased ROS production in AFs.

CONCLUSION

These findings suggest that SABP inhibits the proliferation and oxidation stress in AFs. The present study provides a new evidence that the efficacy and function generated from optimal formulation of active ingredients in SM are better than lyophilized powder of SM.

Exosomes derived from mesenchymal stem cells repair a Parkinson's disease model by inducing autophagy

Parkinson's disease (PD) is a progressively debilitating neurodegenerative condition that leads to motor and cognitive dysfunction. At present, clinical treatment can only improve symptoms, but cannot effectively protect dopaminergic neurons. Several reports have demonstrated that human umbilical cord mesenchymal stem cells (hucMSCs) afford neuroprotection, while their application is limited because of their uncontrollable differentiation and other reasons. Stem cells communicate with cells through secreted exosomes (Exos), the present study aimed to explore whether Exos secreted by hucMSCs could function instead of hucMSCs. hucMSCs were successfully isolated and characterized, and shown to contribute to 6-hydroxydopamine (6-OHDA)-stimulated SH-SY5Y cell proliferation; hucMSC-derived Exos were also involved in this process. The Exos were purified and identified, and then labeled with PKH 26, it was found that the Exos could be efficiently taken up by SH-SY5Y cells after 12 h of incubation. Pretreatment with Exos promoted 6-OHDA-stimulated SH-SY5Y cells to proliferate and inhibited apoptosis by inducing autophagy. Furthermore, Exos reached the substantia nigra through the blood-brain barrier (BBB) in vivo, relieved apomorphine-induced asymmetric rotation, reduced substantia nigra dopaminergic neuron loss and apoptosis, and upregulated the level of dopamine in the striatum. These results demonstrate that hucMSCs-Exos have a treatment capability for PD and can traverse the BBB, indicating their potential for the effective treatment of PD.

Active compounds of herbs ameliorate impaired cognition in APP/PS1 mouse model of Alzheimer's disease

Alzheimer's disease (AD), the most common cause of dementia, is a neurodegenerative disorder characterized by amyloid plaque accumulations, intracellular tangles and neuronal loss in certain brain regions. It has been shown that a disturbance of normal iron metabolism contributes to the pathophysiology of AD. However, the mechanism underlying abnormal iron load in the brain of AD patients is unclear. The frontal cortex, an important brain structure for executive function, is one of the regions affected by AD. We investigated the beneficial effects of active compounds of Epimedium, Astragaoside and Puerarin on iron metabolism in the frontal cortex of six-month-old APPswe/PS1_ΔE9 (APP/PS1) double transgenic mouse, a model of AD. Treatment with the active compounds reduced cognitive and memory deficits and damaged cell ultrastructure in APP/PS1 mice. These beneficial effects were associated with changes in expression levels of iron metabolism proteins in the frontal cortex, including divalent metal transporter with iron response element (DMT1-with IRE), divalent metal transporter without iron response element (DMT1-without IRE), transferrin (TF) and transferring receptor 1 (TfR1); three release proteins including the exporter ferroportin 1 (Fpn1), ceruloplasmin (CP) and hephaestin (HEPH), one increased storage iron protein ferritin and one iron regulating hormone hepcidin. These findings suggest that the active compounds improve cognition and memory in brain neurodegenerative disorders and these beneficial effects are associated with reduced impairment of iron metabolism. This study may provide a new strategy for developing novel drugs to treat AD.

Mixed Aqueous Extract of Salvia Miltiorrhiza Reduces Blood Pressure through Inhibition of Vascular Remodelling and Oxidative Stress in Spontaneously Hypertensive Rats

BACKGROUND/AIMS

Salvia miltiorrhiza (SM) contains four major aqueous active ingredients, which have been isolated, purified and identified as danshensu (DSS), salvianolic acid A (Sal-A), salvianolic acid B (Sal-B) and protocatechuic aldehyde (PAL), totally abbreviated as SABP. Although SM is often used to treat various cardiovascular diseases in traditional Chinese medicine, the efficacy and function of optimal compatibility ratio of SM's active ingredients (SABP) in the prevention and treatment of cardiovascular diseases remain uncertain. This study investigated antihypertensive effect and underlying mechanisms of SABP vs. SM lyophilized powder (SMLP) in spontaneously hypertensive rats (SHR) and to establish the ratio of the optimal compatibility of DSS, Sal-A, Sal-B and PAL in improving cardiovascular functions.

METHODS

The SHRs were treated with either SABP or SMLP and their systolic blood pressures (SBP) were monitored. The isolated thoracic aorta of SHRs was segregated for immunohistochemistry, Hematoxylin-Eosin stain and mRNA and protein expression of NOX4, TGF-β1, Col-I, ET-1, α-SMA and Smad7. Moreover, the adventitial fibroblasts (AFs) were isolated and cultured from SD rats' aorta and the reactive oxygen species (ROS) production was determined after SABP or SMLP treatment.

RESULTS

SABP, but not SMLP, significantly reduced SBP, which were accompanied by the inhibited morphological changes in the thoracic aorta and the reduced mRNA and protein expression of NOX4, TGF-β1, Col-I, ET-1 and α-SMA, but the increased Smad 7 expression in SHRs. Moreover, SABP also resulted in a decreased ROS production in AFs of SD rats.

CONCLUSIONS

These results indicate that SABP, but not SMLP, treatment potently inhibits hypertension through improvements of vascular remodeling and oxidative stress. The present study provides new evidence that the efficacy and function from optimal compatibility ratio of SM active ingredients is much better than its lyophilized powder, which represents a strategy to develop SM's new beneficial effect in improving cardiovascular functions.

[Effects of angiotensin II and its receptor blockers on migration and endothelin-1 expression of rat vascular adventitial fibroblast subpopulations]

The study is to investigate the effect of angiotensin II (Ang II) and its receptor blockers on migration and endothelin-1 (ET-1) expression of rat vascular adventitial fibroblast subpopulations. Vascular adventitial fibroblasts were individually expanded by using cloning rings, and the effects of Ang II on the migration of adventitial fibroblast subpopulations were evaluated by Transwell. Fluorescence quantitative-PCR detected the expression of preproET-1 mRNA induced by Ang II, and its receptor antagonists losartan and PD-123319. The concentration of ET-1 was determined by ELISA. It showed that spindle shaped and epithelioid shaped cells were isolated by using cloning rings, named as spindle cells and round cells. RT-PCR showed that fibroblast subpopulations did not have leukocytes, endothelial cells and smooth muscle cells, namely pure cell lines. Compared with respective control cells, two subpopulations had transferring ability. Ang II significantly improved round cells migration in a concentration-dependent manner, and had no obvious influence on spindle cells migration. Ang II (1 x 10(-8) - 1 x 10(-6) mol x L(-1)) significantly increased the expression of preproET-1 mRNA in round cells (P < 0.01), and had no significant effect on the expression of preproET-1 mRNA in spindle cells. Losartan blocked the expression of preproET-1 mRNA induced by Ang II in round cells, and had no significant effect on the expression of preproET-1 mRNA in spindle cells. The effects of Ang II and ET-1 receptor inhibitors on the release of ET-1 were similar to the expression of preproET-1 mRNA. The results indicate that there are two cell subpopulations: round cells and spindle cells in rat vascular adventitial fibroblasts. Ang II significantly improved cells migration, and increased the expression of ET-1 in round cell subpopulation. It suggested that there may be different migratory mechanisms in two cell subpopulations, and the two subpopulations may play a different role in vascular remodeling and reparative process.

NADPH oxidase mediates angiotensin II-induced endothelin-1 expression in vascular adventitial fibroblasts

OBJECTIVE

We have recently reported that adventitial fibroblasts are able to express endothelin-1 (ET-1) in response to angiotensin II (Ang II) stimulation. However, the mechanism by which this occurs in the adventitia remains unclear. As Ang II has been reported to increase oxidant production by NADPH oxidase, we examined the role of this complex in Ang II stimulated ET-1 expression in vascular adventitial fibroblasts.

METHODS AND RESULTS

Adventitial fibroblasts were isolated and cultured from mouse aorta. Cells were treated with Ang II (100 nmol/L) in the presence or absence of NADPH oxidase inhibitors, apocynin (100 micromol/L) and diphenyleneiodonium (10 micromol/L), superoxide scavengers, SOD (350 units/mL), tempol (100 micromol/L), tiron (100 micromol/L), and ET-receptor antagonists (10 microM), BQ123 (for ET(A)-) and BQ788 (for ET(B)-). PreproET-1 mRNA and ET-1 level were determined by relative RT-PCR and ELISA, respectively. Type I procollagen-alpha-I (collagen) level was detected by Western blot. Superoxide anion (superoxide) production was determined by coelenterazine or lucigenin chemiluminescence. Ang II-induced collagen expression was inhibited by BQ123, suggesting that adventitial ET-1 plays a significant role in regulating the extracellular matrix. NADPH oxidase inhibitors and superoxide scavengers significantly decreased Ang II-induced ET-1 mRNA and peptide expression, superoxide production as well as collagen expression. Furthermore, deletion of gp91(phox) (a key subunit of NADPH oxidase) and overexpression of SOD1 attenuated Ang II-induced responses.

CONCLUSION

Ang II-evoked expression of ET-1 in adventitial fibroblasts appears to be mediated, at least in part, by NADPH oxidase. Functionally, this mechanism stimulates collagen expression thereby implicating the adventitia as a potential contributor to the vascular pathophysiology associated with oxidative stress and vascular remodeling.

Endothelin-1 expression in vascular adventitial fibroblasts

Endothelial cells are a major source of endothelin (ET)-1, but the possibility that vascular adventitial fibroblasts generate ET-1 has not been explored. We hypothesized that aortic adventitial fibroblasts have the ability to produce ET-1, which may contribute to extracellular matrix synthesis. Vascular adventitial fibroblasts were isolated from mouse aorta and incubated with various concentrations of angiotensin II (ANG II). mRNA levels of preproET-1 and type I procollagen were detected with relative RT-PCR. ET-1 levels in culture medium were measured with ELISA. Protein levels of procollagen were detected with Western blotting. ANG II (10 and 100 nM, 1 μM) induced a time- and concentration-dependent increase in preproET-1 mRNA levels ( P < 0.05). Induction of preproET-1 mRNA was accompanied by release of immunoreactive peptide ET-1 ( P < 0.05). ANG II-evoked increases in preproET-1 mRNA expression and ET-1 release were blocked by losartan (100 μM), an AT1 receptor antagonist, but not PD-123319 (100 μM), an AT2 receptor antagonist. To further confirm our findings, we cloned and then sequenced vascular fibroblast preproET-1 bidirectionally with T7 and M13 reverse sequencing primers. Their nucleotide sequences were identical to preproET-1 cDNA from mouse vascular endothelial cells (accession no. AB081657 ). Moreover, ANG II-induced type I procollagen mRNA and protein expression were inhibited by BQ-123 (10 μM), an ETA receptor inhibitor, but not BQ-788 (10 μM), an ETB receptor inhibitor, suggesting a significant role of adventitial ET-1 in regulation of extracellular matrix synthesis. The results demonstrate that vascular adventitial fibroblasts are able to synthesize and release ET-1 in response to ANG II.