He-Ping Zeng

Extracts from plastrum testudinis promote proliferation of rat bone‐marrow‐derived mesenchymal stem cells

Abstract.  Objectives: The purpose of this study is to identify active components of PT involved in promoting proliferation of MSCs and to investigate its mechanism. PT was extracted with petroleum ether, ethyl acetate, ethanol and water respectively. Materials and methods: Evidence provided by MTT, HE stain, BrdUrd, PCNA immunoreactivity and cell cycle indicated that Plastrum Testudinis Extracted with ethyl acetate (PTE) is the only active components responsible for increasing MSCs proliferation. Results: This finding leads us to identify the chemical component of PTE. Steroid, fatty acids and their esters components in PTE were determined by GC‐MS and HPLC. The mechanism of PTE action may be associated with the up‐regulation of BMP4. Conclusions: Our findings give novel insights into the promoting effects of Plastrum Testudinis on proliferation of MSCs and help to identify the chemical component and to clarify the mechanism of its pharmacological activities.

In Vitro Studies on the Antioxidant and Protective Effect of 2-Substituted -8- Hydroxyquinoline Derivatives Against H 2 O 2 - Induced Oxidative Stress in BMSCs

Novel 2‐vinyl‐8‐hydroxyquinoline derivatives as potential antioxidants and regulators of H2O2‐induced oxidative stress in rat bone marrow mesenchymal stem cells (MSCs) are first reported. The antiradical properties and the reducing power of these compounds were assessed using 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) and auto‐oxidation of pyrogallol method, respectively. The activity against lipid peroxidation was determined using ammonium thiocyanate method. The results revealed that introduction of electron‐donating groups at 2nd position decreased the antioxidant activities of 8‐hydroxyquinoline derivatives. In addition, compound 4, the structure of which is similar to melatonin, exhibited superior antioxidant activities in scavenging DPPH free radical, ˙O2 free radical, and anti‐LPO activities. Except for compounds 7, 12, and 15, the other compounds exhibited a stimulatory effect on MSCs growth. Using hydrogen peroxide (H2O2), we also investigated the protective efficacy of 2‐vinyl‐8‐hydroxyquinoline derivatives against oxidative stress‐induced cell death of MSCs. Cell viability assayed by MTT method indicated that exposure of MSCs cultures to hydrogen peroxide resulted in a concentration‐dependent decrease in cell viability, and compounds 4 and 5 at given concentration (2.62 × 10−3 m) could protect MSCs against H2O2‐induced oxidative stress in bone mesenchymal stem cell (BMSCs).

Synthesis and evaluation of novel substituted 5-hydroxycoumarin and pyranocoumarin derivatives exhibiting significant antiproliferative activity against breast cancer cell lines.

A library of novel 5-hydroxycoumarin and pyranocoumarin derivatives was constructed via silica sulfuric acid-catalyzed pechmann reaction and Pd(0)-catalyzed suzuki coupling in tandem, and their antiproliferative activities against breast cancer cells MCF-7 and MDA-MB-231 were evaluated. The results showed that compounds such as 6b, 6d, 6h, and 6k possess significant antiproliferative activity against MCF-7 cell line with the IC(50) values of 7.2, 5.3, 3.3, and 6.5 microM, respectively.

Ion-induced cycle opening of a diarylethene and its application on visual detection of Cu2+ and Hg2+ and keypad lock

A phenanthrene-bridged photochromic diarylethene with two crown ethers as ion recognizing groups has been synthesized and characterized by single crystal X-ray diffraction. This material shows good photochromism and fatigue resistance. Only the closed form of this diarylethene derivative can form coordination complexes with Cu2+ and Hg2+ and at the same time, the combination of the photochromic material and metal ions would lead to the cycle opening of the closed photochromic unit and color bleaching processes. This special property can be applied in the visual detection of these two heavy metal ions not only in solution but also in solid state. The fluorescence of the diarylethene is sensitive to light, copper and mercury ions. As a result, a single molecular logic circuit was constructed using the absorbance and fluorescence intensity at a specific wavelength as outputs and appropriate combinational stimuli of UV/Vis light, Cu2+ and Hg2+ ions as inputs. Moreover, its fluorescence is sensitive to historical input signals. Based on this, a key pad lock using three codes to open was fabricated.

Hexadecanoic Acid from Buzhong Yiqi Decoction Induced Proliferation of Bone Marrow Mesenchymal Stem Cells

Buzhong Yiqi decoction (BYD) is a well-known ancient tonic prescription in traditional Chinese medicine (TCM). The purpose of this study is to identify active components of BYD involved in promoting proliferation of mesenchymal stem cells (MSCs) and to investigate its mechanism. BYD was extracted with petroleum ether, ethanol, and water. Evidence provided by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, bromodeoxyuridine, proliferation cell nuclear antigen immunoreactivity, cell cycle analysis, and gas chromatography-mass spectrometry indicated that hexadecanoic acid (HA) in BYD extracted with petroleum ether is the active compound responsible for increasing proliferation of MSCs. Western blot analysis show that HA significantly increase retinoic acid receptor (RAR) levels of MSCs, but not estrogen receptor, thyroid hormone receptor, vitamin D receptor, glucocorticoid receptor, and peroxisome proliferator-activated receptor. Reverse transcription-polymerase chain reaction revealed that HA significantly increased RAR mRNA levels. Furthermore, the mechanism of HA action depends on RAR pathway and up-regulates expression of mRNA for insulin-like growth factor-I, the target gene of RAR. Our findings have now allowed for a refinement in our understanding of TCM with respect to pharmacological regulation of stem cells and may be useful to stem cell biology and therapy.

Characterization of chemical components in extracts from Si-wu decoction with proliferation-promoting effects on rat mesenchymal stem cells

Si-wu decoction (SDE), a classic prescription in Traditional Chinese Medicine, has been used for the treatment of a variety of anaemia in China for centuries. In order to explore the scientific basis of the formula, we investigated the relationship between its chemical components and proliferation-promoting effects on rat marrow-derived mesenchymal stem cells (MSCs). Twenty (F-1-F-20) components were obtained and their proliferation-promoting effects on MSCs were investigated. The results showed that F-4, F-7, F-10, and F-11 stimulated the proliferation of the MSCs. The chemical components with proliferation-promoting effects on the MSCs were further identified by GC-MS, HPLC, LC-MS, and other spectra. Ligustilide (F-4) isolated from SDE showed the best proliferation-promoting effect. Palmitic acid methyl ester and stearic acid ethyl identified from F-7 and F-10 by HPLC were also confirmed to be responsible for stimulating MSC proliferation. A novel compound, 6,7-dihydroxy-3-(-prop-1-enyl)isobenzofuran-1(3H)-one, was found in the SDE for the first time by LC-MS(n), whose structure was similar to ligustilide.

Cholesterol myristate suppresses the apoptosis of mesenchymal stem cells via upregulation of inhibitor of differentiation

To identify small molecules that suppress the apoptosis of mesenchymal stem cells (MSCs) is promising for stem cell therapy. We recently showed that bone morphogenetic protein 4 (BMP4) signalling involves the effect of cholesterol myristate on the proliferation of MSCs. The present study evaluated the effects of cholesterol myristate on the apoptosis of MSCs and the inhibitor of differentiation (Id1), target gene of BMP4 signalling. MSCs transfected by the Id1 promoter reporter construct, cholesterol myristate increases the activity of Id1 promoter. However, structurally related steroids such as cholesterol, β-sitosterol and cholesten-3-one, lack of the myristate, did not affect the activity of Id1 promoter, suggesting that myristate is essential for this effect. This effect depends on BMP signalling. Apoptosis analysis indicated that cholesterol myristate inhibited the apoptosis of MSCs induced by serum-free. Cholesterol myristate increases the expression of Id1 and its target gene bcl-x/l in MSCs treated with serum-free. Moreover, noggin, a BMP antagonist, reduced the anti-apoptotic effects of cholesterol myristate. Thus, this study aims to provide evidence that cholesterol myristate suppresses the apoptosis of MSCs via up-regulation of Id1. These findings can be applied for improving MSCs survival in stem-cell transplantation, bone-marrow transplantation, treatment of bone diseases such as osteoporosis and chemotherapy.

Syntheses, structures, and luminescence of two Zn(II) coordination polymers based on 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole and carboxylates

Reactions of Zn(II) salts, 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and 2-mercaptobenzoic acid or 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H3PrIDC), result in two mixed-ligand coordination polymers (CPs), [Zn2(IPT)(DSDB)(OH)]n (H2DSDB = 2,2′-disulfanediyldibenzoic acid, 1) and [Zn2(IPT)(PrIDC)(H2O)]n (H3PrIDC = 2-propyl-1H-imidazole-4,5-dicarboxylic acid, 2). Compound 1 possesses a 2-D structure built by 1-D [Zn(IPT)]n chains and DSDB2− connectors, in which the DSDB2− is generated via in situ reaction from 2-mercaptobenzoic acid. It displays a new intricate 4-nodal {3·4·6·7·8·9}{3·6·7·8·9·10}{3·8·9}{4·6·8} topology. Compound 2 displays a 3-D framework with new 3-connected topology with Schläfli symbol of (4·8·10) (8·122), in which the 1-D Zn-carboxylate chains were bridged by 3-connected IPT− ligands. The thermal stabilities and luminescence properties of 1 and 2 have also been studied. The compounds exhibit intense solid-state fluorescent emissions at room temperature. Two Zn(II) coordination polymers with intricate 2-D network and 3-D framework with new 3-connected topology were constructed.

Chemical components in extracts from Plastrum testudinis with proliferation-promoting effects on rat mesenchymal stem cells.

Plastrum Testudinis (PT) is often used as an important traditional Chinese medicine to treat bone diseases in China for centuries. To identify active components of PT involved in promoting proliferation of MSCs, PT was extracted with ethyl acetate and separated by silica gel column chromatography with gradient elution. Sixteen (Ts‐1 ∼ 16) components were obtained, which were biologically evaluated by MTT assay and flow cytometry on the proliferation of rat marrow‐derived mesenchymal stem cells (rMSCs). Results indicated that Ts‐12 could induce the proliferation compared with control group (p < 0.05), while Ts‐4 exhibited inhibitive effect. The chemical components of PT which regulated the proliferation of rMSCs were investigated by Gas Chromatography‐Mass Spectrometry (GC‐MS), HPLC, and nine standard compounds. The experimental results suggested that palmitic acid methyl ester and cholesterol myristate, which identified from Ts‐12, possessed proliferative activity while stearic acid found in Ts‐4 showed inhibition.

(+)-Cholesten-3-one induces differentiation of neural stem cells into dopaminergic neurons through BMP signaling

To identify small molecules that induce dopaminergic neurons from neural stem cells (NSCs) is promising for therapy of Parkinsons disease. Here we report the results of analyzing structurally related steroids in traditional Chinese medicine to identify agents that enhance dopaminergic differentiation of NSCs. Using P19 cells transfected by tyrosine hydroxylase (TH) promoter reporter construct, (+)-Cholesten-3-one with carbonyl, but not cholesterol and cholesterol myristate can effectively promote the activity of TH promoter. This effect depends on bone morphogenetic protein (BMP) signaling. Phenotypic cellular analysis indicated that (+)-Cholesten-3-one induces differentiation of NSCs to dopaminergic neurons with increased expression of specific dopaminergic markers including TH, dopamine transporter, dopa decarboxylase and higher level of dopamine secretion. (+)-Cholesten-3-one significantly increases the expression of BMPR IB, but not BMPR IA or BMPR II; p-Smad1/5/8 positive nuclei and expression of p-Smad1/5/8 were detected in NSCs treated with (+)-Cholesten-3-one, indicating that (+)-Cholesten-3-one may activate the BMP signaling. Moreover, overexpression of BMP4 or inhibition of BMP affects the effect of (+)-Cholesten-3-one on the dopaminergic phenotype. These findings may contribute to efficient production of dopaminergic neurons from NSCs culture for many applications and raise interesting questions about the role of (+)-Cholesten-3-one in neurogenesis.