Zinc as a potential regulator of the BCR-ABL oncogene in chronic myelocytic leukemia cells.

BACKGROUND: Generally, decreased zinc in the serum of tumor patients but increased zinc in tumor cells can be observed. However, the role of zinc homeostasis in myeloid leukemia remains elusive. BCR-ABL is essential for the initiation, maintenance, and progression of chronic myelocytic leukemia (CML). We are currently investigating the association between zinc homeostasis and CML. METHODS: Genes involved in zinc homeostasis were examined using three GEO datasets. Western blotting and qPCR were used to investigate the effects of zinc depletion on BCR-ABL expression. Furthermore, the effect of TPEN on BCR-ABL promoter activity was determined using the dual-luciferase reporter assay. MRNA stability and protein stability of BCR-ABL were assessed using actinomycin D and cycloheximide. RESULTS: Transcriptome data mining revealed that zinc homeostasis-related genes were associated with CML progression and drug resistance. Several zinc homeostasis genes were affected by TPEN. Additionally, we found that zinc depletion by TPEN decreased BCR-ABL mRNA stability and transcriptional activity in K562 CML cells. Zinc supplementation and sodium nitroprusside treatment reversed BCR-ABL downregulation by TPEN, suggesting zinc- and nitric oxide-dependent mechanisms. CONCLUSION: Our in vitro findings may help to understand the role of zinc homeostasis in BCR-ABL regulation and thus highlight the importance of zinc homeostasis in CML.

Zinc depletion induces JNK/p38 phosphorylation and suppresses Akt/mTOR expression in acute promyelocytic NB4 cells.

BACKGROUND: Myeloid leukemia is associated with reduced serum zinc and increased intracellular zinc. Our previous studies found that zinc depletion by TPEN induced apoptosis with PML-RARα oncoprotein degradation in acute promyelocytic NB4 cells. The effect of zinc homeostasis on intracellular signaling pathways in myeloid leukemia cells remains unclear. OBJECTIVE: This study examined how zinc homeostasis affected MAPK and Akt/mTOR pathways in NB4 cells. METHODS: We used western blotting to detect the activation of p38 MAPK, JNK, ERK1/2, and Akt/mTOR pathways in NB4 cells stimulated with the zinc chelator TPEN. Whether the effects of TPEN on these pathways could be reversed by zinc or the nitric oxide donor sodium nitroprusside (SNP) was further explored by western blotting. We used Zinpyr-1 staining to assess the role of SNP on labile zinc levels in NB4 cells treated with TPEN. In additional, we evaluated expressional correlations between the zinc-binding protein Metallothionein-2A (MT2A) and genes related to MAPKs and Akt/mTOR pathways in acute myeloid leukemia (AML) based on the TCGA database. RESULTS: Zinc depletion by TPEN activated p38 and JNK phosphorylation in NB4 cells, whereas ERK1/2 phosphorylation was increased first and then decreased. The protein expression levels of Akt and mTOR were downregulated by TPEN. The nitric oxide donor SNP promotes zinc release in NB4 cells under zinc depletion conditions. We further found that the effects of zinc depletion on MAPK and Akt/mTOR pathways in NB4 cells can be reversed by exogenous zinc supplementation or treatment with the nitric oxide donor SNP. By bioinformatics analyses based on the TCGA database, we demonstrated that MT2A expression was negatively correlated with the expression of JNK, and was positively correlated with the expression of ERK1 and Akt in AML. CONCLUSION: Our findings indicate that zinc plays a critical role in leukemia cells and help understanding how zinc depletion induces apoptosis.

Co-delivery of TRAIL and siHSP70 using hierarchically modular assembly formulations achieves enhanced TRAIL-resistant cancer therapy.

The combined therapy of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and heat shock protein 70-targeting siRNA (siHSP70) has shown an improved anti-tumor effect on TRAIL-resistant tumor. However, vehicles to co-deliver these two biopharmaceuticals are challenging because of the distinct location of their targets on the cell surface and in the cytosol. Here we developed a hierarchically modular assembly formulation (TH-s-RSC) via the copper-free click reaction to co-encapsulate the positively-charged TRAIL and negatively-charged siHSP70 and release them in the extracellular space and cytoplasm. We demonstrate that TH-s-RSC can protect the packaged biopharmaceuticals through its hyaluronic acid shell in vivo, and sequentially release TRAIL in response to extracellular molecular including hyaluronidase (HAase) and matrix metalloproteinase 2 (MMP2), followed by the release of siHSP70 triggered by the reductive conditions in the cytoplasm. We showed that the complementary activity of TRAIL and siHSP70 exhibited superior synergistic anticancer efficacy in both A549 lung cancer xenograft models and 4T1 lung metastatic breast cancer models, compared to either treatment alone. Our strategy provides a promising platform for safe and effective co-delivery and dual-site targeting of biopharmaceuticals in cancer treatment that may be applicable in the future.

IR820 covalently linked with self-assembled polypeptide for photothermal therapy applications in cancer.

Owing to the unique advantages of high specificity and minimal invasiveness, photothermal therapy (PTT) has been evidenced with great potential in cancer treatment. However, most photothermal agents present a shortage of photobleaching and nonspecific biodistribution in clinical application. In this study, we conjugated a new Indocyanine Green Dye (IR820) with self-assembled polypeptide (ELP) via chemical bonding in an aqueous environment. This preparation method could effectively avoid damaging the polypeptide. ELP-IR820 was fabricated as nanoconjugates with diameters of approximately 50 nm. The use of ELP-IR820 notably enhanced photothermal-mediated cytotoxicity on CT-26 cancer cells. We demonstrate that the ELP-IR820 nanoparticles significantly improved drug accumulation in the tumor and photothermal effect in vivo compared to the free dye and monomer ELP-IR820. ELP-IR820 nanoparticle also exhibited outstanding ability to cause prominent tumor tissue growth inhibition via the photothermal effect. No noticeable toxicity was detected for all treatment groups. These investigations broaden the application of NIR dyes as a multimodal photothermal therapy platform.

Zinc Depletion by TPEN Induces Apoptosis in Human Acute Promyelocytic NB4 Cells.

BACKGROUND/AIMS: The effects of zinc signaling on proliferation or apoptosis of leukemia cells remain elusive. In the present study, we used N, N, N', N'-tetrakis-(2-pyridylmethyl)-ethylene-diamine (TPEN), a membrane-permeable zinc chelator, to evaluate the effect of zinc depletion on survival and apoptosis of NB4 acute promyelocytic leukemia (APL) cells. METHODS: The pro-apoptotic effects of TPEN on NB4 cells were examined by flow cytometry, and observed using an optical microscope. Intracellular labile zinc, nitric oxide (NO) or reactive oxygen species (ROS) changes caused by TPEN were measured by flow cytometry. We then explored possible roles of the crosstalk between intracellular labile zinc signaling and nitric oxide signaling in TPEN-triggered apoptosis. RESULTS: we found that TPEN induced apoptosis in NB4 APL cells in a dosage-dependent manner. We further demonstrated that TPEN triggered apoptosis by attenuating intracellular zinc and nitric oxide signaling in NB4 cells. Both exogenous zinc supplement and the nitric donor sodium nitroprusside (SNP) pre-incubation reversed TPEN-mediated inhibition of intracellular NO and Zn2+ signaling, and rescued NB4 cells from apoptosis. CONCLUSION: These results suggest for the first time that crosstalk between zinc signaling and nitric oxide pathway is essential for the survival of NB4 cells. TPEN induces apoptosis in NB4 cells via negatively regulating intracellular NO and Zn2+ signaling. Our in vitro data suggest that zinc depletion by TPEN may be a potential therapeutic strategy for APL.

Modulation of Salmonella Tumor-Colonization and Intratumoral Anti-angiogenesis by Triptolide and Its Mechanism.

The weakened tumour colonization of attenuated Salmonella has severely hampered its clinical development. In this study, we investigated whether an anti-inflammation and antiangiogenesis compound triptolide could improve the efficacy of VNP20009, a highly attenuated Salmonella strain, against mice melanoma. By comparing the effects of conventional VNP20009 monotherapy and a combination therapy that uses both triptolide and VNP20009, we found that triptolide significantly improved the tumour colonization of VNP20009 by reducing the number of infiltrated neutrophils in the melanoma, which led to a larger necrotic area in the melanoma. Moreover, the combination therapy suppressed tumour angiogenesis by reducing the expression of VEGF in a synergistic manner, retarding the growth of the melanoma. Our study revealed that triptolide could significantly enhance the antitumour effect of VNP20009 by modulating tumour angiogenesis and the host immune response, providing a new understanding of the strategy to improve Salmonella-mediated tumour therapy.

Target identification with quantitative activity based protein profiling (ABPP).

As many small bioactive molecules fulfill their functions through interacting with protein targets, the identification of such targets is crucial in understanding their mechanisms of action (MOA) and side effects. With technological advancements in target identification, it has become possible to accurately and comprehensively study the MOA and side effects of small molecules. While small molecules with therapeutic potential were derived solely from nature in the past, the remodeling and synthesis of such molecules have now been made possible. Presently, while some small molecules have seen successful application as drugs, the majority remain undeveloped, requiring further understanding of their MOA and side effects to fully tap into their potential. Given the typical promiscuity of many small molecules and the complexity of the cellular proteome, a high-flux and high-accuracy method is necessary. While affinity chromatography approaches combined with MS have had successes in target identification, limitations associated with nonspecific results remain. To overcome these complications, quantitative chemical proteomics approaches have been developed including metabolic labeling, chemical labeling, and label-free methods. These new approaches are adopted in conjunction with activity-based protein profiling (ABPP), allowing for a rapid process and accurate results. This review will briefly introduce the principles involved in ABPP, then summarize current advances in quantitative chemical proteomics approaches as well as illustrate with examples how ABPP coupled with quantitative chemical proteomics has been used to detect the targets of drugs and other bioactive small molecules including natural products.

Target identification of natural and traditional medicines with quantitative chemical proteomics approaches.

Natural and traditional medicines, being a great source of drugs and drug leads, have regained wide interests due to the limited success of high-throughput screening of compound libraries in the past few decades and the recent technology advancement. Many drugs/bioactive compounds exert their functions through interaction with their protein targets, with more and more drugs showing their ability to target multiple proteins, thus target identification has an important role in drug discovery and biomedical research fields. Identifying drug targets not only furthers the understanding of the mechanism of action (MOA) of a drug but also reveals its potential therapeutic applications and adverse side effects. Chemical proteomics makes use of affinity chromatography approaches coupled with mass spectrometry to systematically identify small molecule-protein interactions. Although traditional affinity-based chemical proteomics approaches have made great progress in the identification of cellular targets and elucidation of MOAs of many bioactive molecules, nonspecific binding remains a major issue which may reduce the accuracy of target identification and may hamper the drug development process. Recently, quantitative proteomics approaches, namely, metabolic labeling, chemical labeling, or label-free approaches, have been implemented in target identification to overcome such limitations. In this review, we will summarize and discuss the recent advances in the application of various quantitative chemical proteomics approaches for the identification of targets of natural and traditional medicines.

MicroRNA-31 negatively regulates peripherally derived regulatory T-cell generation by repressing retinoic acid-inducible protein 3.

Peripherally derived regulatory T (pT(reg)) cell generation requires T-cell receptor (TCR) signalling and the cytokines TGF-ß1 and IL-2. Here we show that TCR signalling induces the microRNA miR-31, which negatively regulates pT(reg)-cell generation. miR-31 conditional deletion results in enhanced induction of pT(reg) cells, and decreased severity of experimental autoimmune encephalomyelitis (EAE). Unexpectedly, we identify Gprc5a as a direct target of miR-31. Gprc5a is known as retinoic acid-inducible protein 3, and its deficiency leads to impaired pT(reg-)cell induction and increased EAE severity. By generating miR-31 and Gprc5a double knockout mice, we show that miR-31 promotes the development of EAE through inhibiting Gprc5a. Thus, our data identify miR-31 and its target Gprc5a as critical regulators for pT(reg)-cell generation, suggesting a previously unrecognized epigenetic mechanism for dysfunctional T(reg) cells in autoimmune diseases.

[Effect of retinociacdi combined extracts from testudinis carapacis et plastri on proliferating in MSCs and its mechanism].

OBJECTIVE: To explore the effect of retinociacdi (RA) combined extracts from Testudinis Carapacis et Plastri(PTE) on proliferating in MSCs and its mechanism. METHODS: Transfected PGL3-ID1 using the calcium phosphate co-precipitation method in rat MSCs. PTE combined with RA and retinociacdi receptor inhibitor(Ro41) acted on transfected MSCs with respective concentrations of 10(-6), 10(-7) and 10(-8) mol/L. Luciferase activity measurement was used to detect the activity of RAR and IDI 36 h later. PTE acted on MSCs 36 h,3 d and 7 d for respective concentrations of 1, 3, 30 and 100 microg/mL,then collected cells to detect RAR with RT-PCR. PTE combined with RA for 10(-7) mol/L and Ro41 for 10(-6) mol/L respectively on MSCs for 36 h,and then collected cells to detect RAR and ID1 with RT-PCR. RESULTS: PTE promoted expression of ID1 on MSCs. When combined with RA, the promotion effect became greater and it promoted expression of RAR at the same time; When inhibited RA using Ro41, the promotion of IDI was weaken by PTE. CONCLUSION: RA promotes expression of IDI on MSCs, PTE regulates proliferation and differentiation of MSCs by expression of nuclear receptor RAR.

Supplementation of the diet with Salecan attenuates the symptoms of colitis induced by dextran sulphate sodium in mice.

As a water-soluble extracellular ß-glucan produced by Agrobacterium sp. ZX09, Salecan has an excellent toxicological profile and exerts multiple physiological effects. The aims of the present study were to investigate the protective effects of a Salecan diet in the well-defined dextran sulphate sodium (DSS) model of experimental murine colitis and to elucidate the mechanism involved in its effects with special attention being paid to its effect on the production of TNF-α, a primary mediator involved in the inflammatory response. Male C57BL/6J mice were fed a diet supplemented with either 4 or 8 % Salecan for 26 d and DSS was administered to induce acute colitis during the last 5 d of the experimental period. Several clinical and inflammatory parameters as well as mRNA expression of TNF-α and Dectin-1 were evaluated. The results indicated that the dietary incorporation of Salecan attenuated the severity of DSS colitis as evidenced by the decreased disease activity index, reduced severity of anaemia, attenuated changes in colon architecture and reduced colonic myeloperoxidase activity. This protection was associated with the down-regulation of TNF-α mRNA levels, which might derive from its ability to increase Dectin-1 mRNA levels. In conclusion, the present study suggests that Salecan contributes to the reduction of colonic damage and inflammation in mice with DSS-induced colitis and holds promise as a new, effective nutritional supplement in the management of inflammatory bowel disease.

Herbal compound triptolide synergistically enhanced antitumor activity of vasostatin120-180.

Angiogenesis is essential for the survival and growth of most tumors. As such, targeting the tumor neovasculature is an attractive strategy for effective cancer therapy. Angiogenesis inhibitors have strong therapeutic potential as antitumor agents in suppressing tumor growth and metastatic progression. The functional domain within amino acid residues 120-180 of vasostatin (VAS) has been confirmed to be effective in inhibiting the proliferation, migration, and invasiveness of cancer cells by its suppressive capacity against angiogenesis. Triptolide (TPL) is an active component extracted from the traditional Chinese herbal medicine Tripterygium wilfordii Hook F that has shown antitumor activities in various cancer cell types. However, its therapeutic application is limited by its toxicity in normal tissues and complications caused in patients. In this study, we attempted to investigate the synergistic antitumor activity of TPL and VAS in solid tumor cells. Our results showed that the sensitivity of combined therapy using TPL and VAS was higher than that of monotherapy using TPL or VAS. Apoptosis induced by the combined treatment was accompanied by activation of caspase-9, caspase-8, and caspase-3. Upregulation of proapoptotic protein (Bax, Bak, and Bad) expression and suppression of NF-κB transcriptional activity and its targeting antiapoptotic genes (c-FLIP, cIAP, Bcl-2, Bcl-xl, and Mcl-1) may contribute to the synergistic effects of this combination therapy. Further, using a mouse xenograft model, we demonstrated that combined treatment completely suppressed tumor growth as compared with treatment with TPL or VAS alone. These results suggest that the combination of TPL and VAS at lower concentrations may produce a synergistic antitumor effect that warrants further investigation for its potential clinical applications.

Herbal compound triptolide synergistically enhanced antitumor activity of amino-terminal fragment of urokinase.

BACKGROUND: Urokinase (uPA) and its receptor (uPAR) play an important role in tumour growth and metastasis, and overexpression of these molecules is strongly correlated with poor prognosis in a variety of malignant tumours. Targeting the excessive activation of this system as well as the proliferation of the tumour vascular endothelial cell would be expected to prevent tumour neovasculature and halt tumour development. The amino terminal fragment (ATF) of urokinase has been confirmed effective to inhibit the proliferation, migration and invasiveness of cancer cells via interrupting the interaction of uPA and uPAR. Triptolide (TPL) is a purified diterpenoid isolated from the Chinese herb Tripterygium wilfordii Hook F that has shown antitumor activities in various cancer cell types. However, its therapeutic application is limited by its toxicity in normal tissues and complications caused in patients. In this study, we attempted to investigate the synergistic anticancer activity of TPL and ATF in various solid tumour cells. METHODS: Using in vitro and in vivo experiments, we investigated the combined effect of TPL and ATF at a low dosage on cell proliferation, cell apoptosis, cell cycle distribution, cell migration, signalling pathways, xenograft tumour growth and angiogenesis. RESULTS: Our data showed that the sensitivity of a combined therapy using TPL and ATF was higher than that of TPL or ATF alone. Suppression of NF-κB transcriptional activity, activation of caspase-9/caspase-3, cell cycle arrest, and inhibition of uPAR-mediated signalling pathway contributed to the synergistic effects of this combination therapy. Furthermore, using a mouse xenograft model, we demonstrated that the combined treatment completely suppressed tumour growth by inhibiting angiogenesis as compared with ATF or TPL treatment alone. CONCLUSIONS: Our study suggests that lower concentration of ATF and TPL used in combination may produce a synergistic anticancer efficacy that warrants further investigation for its potential clinical applications.

IL-10-producing regulatory B10 cells ameliorate collagen-induced arthritis via suppressing Th17 cell generation.

IL-10-producing CD1d(hi)CD5(+) B cells, also known as B10 cells, have been shown to possess a regulatory function in the inhibition of immune responses, but whether and how B10 cells suppress the development of autoimmune arthritis remain largely unclear. In this study, we detected significantly decreased numbers of IL-10-producing B cells, but increased IL-17-producing CD4(+) T (Th17) cells in both spleen and draining lymph nodes of mice during the acute stage of collagen-induced arthritis (CIA) when compared with adjuvant-treated control mice. On adoptive transfer of in vitro expanded B10 cells, collagen-immunized mice showed a marked delay of arthritis onset with reduced severity of both clinical symptoms and joint damage, accompanied by a substantial reduction in the number of Th17 cells. To determine whether B10 cells directly inhibit the generation of Th17 cells in culture, naive CD4(+) T cells labeled with carboxyfluorescein succinimidyl ester (CFSE) were co-cultured with B10 cells. These B10 cells suppressed Th17 cell differentiation via the reduction of STAT3 phosphorylation and retinoid-related orphan receptor γt (RORγt) expression. Moreover, Th17 cells showed significantly decreased proliferation when co-cultured with B10 cells. Although adoptive transfer of Th17 cells triggered the development of collagen-induced arthritis in IL-17(-/-)DBA/1J mice, co-transfer of B10 cells with Th17 cells profoundly delayed the onset of arthritis. Thus, our findings suggest a novel regulatory role of B10 cells in arthritic progression via the suppression of Th17 cell generation.

Thioredoxin glutathione reductase as a novel drug target: evidence from Schistosoma japonicum.

BACKGROUND: Schistosomiasis remains a major public health concern affecting billions of people around the world. Currently, praziquantel is the only drug of choice for treatment of human schistosomiasis. The emergence of drug resistance to praziquantel in schistosomes makes the development of novel drugs an urgent task. Thioredoxin glutathione reductase (TGR) enzymes in Schistosoma mansoni and some other platyhelminths have been identified as alternative targets. The present study was designed to confirm the existense and the potential value of TGR as a target for development of novel antischistosomal agents in Schistosoma japonicum, a platyhelminth endemic in Asia. METHODS AND FINDINGS: After cloning the S. japonicum TGR (SjTGR) gene, the recombinant SjTGR selenoprotein was purified and characterized in enzymatic assays as a multifunctional enzyme with thioredoxin reductase (TrxR), glutathione reductase (GR) and glutaredoxin (Grx) activities. Immunological and bioinformatic analyses confirmed that instead of having separate TrxR and GR proteins in mammalian, S. japonicum only encodes TGR, which performs the functions of both enzymes and plays a critical role in maintaining the redox balance in this parasite. These results were in good agreement with previous findings in Schistosoma mansoni and some other platyhelminths. Auranofin, a known inhibitor against TGR, caused fatal toxicity in S. japonicum adult worms in vitro and reduced worm and egg burdens in S. japonicum infected mice. CONCLUSIONS: Collectively, our study confirms that a multifunctional enzyme SjTGR selenoprotein, instead of separate TrxR and GR enzymes, exists in S. japonicum. Furthermore, TGR may be a potential target for development of novel agents against schistosomes. This assumption is strengthened by our demonstration that the SjTGR is an essential enzyme for maintaining the thiol-disulfide redox homeostasis of S. japonicum.

Synergistic antitumor activity of oridonin and arsenic trioxide on hepatocellular carcinoma cells.

Although arsenic trioxide (As2O3) has been successfully employed in treatment of patients with APL (acute promyelocytic leukemia), the sensitivity of solid tumor cells to this treatment was much lower than APL cells. The single agent of As2O3 was inefficient for treatment of hepatocellular carcinoma (HCC) in phase II trial demonstrating that new modalities of treatment with enhanced therapeutic effect are needed. In this study, we showed that oridonin, a diterpenoid isolated from traditional Chinese medicine Rabdosia rubescences, greatly potentiated apoptosis induced by As2O3 in hepatocellular carcinoma cells. The synergistic pro-apoptosis effect of combination of these two drugs led to increase in intracellular reactive oxygen species (ROS) level and N-acetyl-L-cysteine (NAC), a thiol-containing anti-oxidant, was able to completely block the effect. The combination treatment induced ROS-dependent decrease in mitochondrial membrane potential (MMP) decrease, and relocation of Bax and cytochrome C. Besides, oridonin dramatically increased the intracellular Ca2+ overload triggered by As2O3. Furthermore, the co-treatment of oridonin and As2O3 induced ROS-mediated down-regulation of Akt and XIAP, and inhibition of NF-κB activation. The two drug combination enhanced tumor suppression activity in murine HCC model compared with single agent treatment in vivo. These findings demonstrate that oridonin can sensitize hepatocellular carcinoma cells to As2O3 treatment and will facilitate the optimization of As2O3 therapy for HCC patients.

Proteomic screening of anaerobically regulated promoters from Salmonella and its antitumor applications.

Solid tumors often contain hypoxic and necrotic areas that can be targeted by attenuated Salmonella typhimurium VNP20009 (VNP). We sought to develop a hypoxia- inducible promoter system based on the tumor-specific delivered strain VNP to confine expression of therapeutic gene specifically or selectively within the tumor microenvironment. A hypoxia-inducible promoter - adhE promoter was screened from the hypoxia-regulated endogenous proteins of Salmonella through two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight/time-of-flight MS-based proteomics approaches. The efficiency and specificity of the selected adhE promoter were validated first in both bacteria and animal tumor models. The adhE promoter could specifically drive GFP gene expression under hypoxia, but not under normoxia. Furthermore, luciferase reporter expression controlled by the system was also confined to the tumors. Finally, we investigated the anticancer efficacy of VNP delivering human endostatin controlled by our adhE promoter system in both murine melanoma and Lewis lung carcinoma models. Our results demonstrated that by the dual effects of tumoricidal and anti-angiogenic activities, the recombinant Salmonella strain could generate enhanced antitumor effects compared with those of unarmed VNP treatment or untreated control. The recombinant VNP could retard tumor growth significantly and extend survival of tumor-bearing mice by inducing more apoptosis and more severe necrosis as well as inhibiting blood vessel density within tumors. Therefore, VNP carrying the endostatin gene under our tumor-targeted expression system holds promise for the treatment of solid tumors.

BMP-Id pathway targeted by cholesterol myristate suppresses the apoptosis of PC12 cells.

Identifying small molecules that suppress apoptosis is promising for the therapy of brain diseases. We recently showed that autocrine bone morphogenetic protein (BMP) signaling involves the effects of cholesterol myristate present in traditional Chinese medicine on mesenchymal stem cells. The present study evaluated the effects of cholesterol myristate on the apoptosis and BMP signaling of PC12 cells. PC12 cells transfected by the inhibitor of differentiation (Id1) promoter reporter construct target gene of BMP4 signaling; cholesterol myristate increases the activity of Id1 promoter. However, structurally related steroids such as cholesterol, ß-sitosterol and cholesten-3-one, lack of the myristate, did not affect the activity of Id1 promoter, suggesting that myristate is essential for the effect of cholesterol myristate. These effects depend on BMP signaling. Apoptosis analysis indicated that cholesterol myristate inhibited the apoptosis of PC12 cells induced in serum-free condition. Cholesterol myristate significantly increases the expression of BMP4, BMPRIA, p-Smad1/5/8, Id1 and its antiapoptotic target gene Bcl-xL in PC12 cells treated in serum-free condition. Moreover, BMP antagonist reduced the anti-apoptotic effect of cholesterol myristate. Thus, this study is to provide evidence that BMP-Id pathway targeted by cholesterol myristate suppresses the apoptosis of PC12 cells. Our findings are therefore of considerable therapeutic significance and provide the potential of newly exploiting cholesterol myristate and clinically in brain disease therapies.

(+)-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 Parkinson's 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.

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.