The selenoprotein P-LRP5/6-WNT3A complex promotes tumorigenesis in sporadic colorectal cancer.

Some studies suggest that the trace element selenium protects against colorectal cancer (CRC). However, the contribution of selenoprotein P (SELENOP), a unique selenocysteine-containing protein, to sporadic colorectal carcinogenesis challenges this paradigm. SELENOP is predominately secreted by the liver but is also expressed in various cells of the small intestine and colon in mice and humans. In this issue of the JCI, Pilat et al. demonstrate that increased SELENOP expression promoted the progression of conventional adenomas to carcinoma. SELENOP functioned as a modulator of canonical WNT signaling activity through interactions with WNT3A and its coreceptor LDL receptor-related protein 5/6 (LRP5/6). Secreted SELENOP formed a concentration gradient along the gut crypt axis, which might amplify WNT signaling activity by binding to LRPL5/6. The mechanism for WNT control via SELENOP may affect colorectal tumorigenesis and provide therapeutic targets for CRC.

Rhizoma drynariae total flavonoids combined with calcium carbonate ameliorates bone loss in experimentally induced Osteoporosis in rats via the regulation of Wnt3a/ß-catenin pathway.

BACKGROUND: Rhizoma drynariae, a traditional Chinese herb, is commonly used in treatment of bone healing in osteoporotic fractures. However, whether the Rhizoma drynariae total flavonoids (RDTF) can promote the absorption of calcium and enhance the bone formation is unclear. The aim of the present study was to investigate the preventive effects of RDTF combined with calcium carbonate (CaCO3) on estrogen deficiency-induced bone loss. METHODS: Three-month-old Sprague-Dawley rats were ovariectomized (OVX) and then treated with CaCO3, RDTF, and their admixtures for ten weeks, respectively. The bone trabecular microstructure, bone histopathological examination, and serum biomarkers of bone formation and resorption were determined in the rat femur tissue. The contents of osteoprotegerin (OPG), receptor activator of the NF-κB (RANK), and its ligand (RANKL) in marrow were analyzed by ELISA, and the protein expressions of Wnt3a, ß-catenin, and phosphorylated ß-catenin (p-ß-catenin) were analyzed by Western blot. Statistical analysis was conducted by using one-way analysis of variance (ANOVA) followed by LSD post hoc analysis or independent samples t test using the scientific statistic software SPSS version 20.0 RESULTS: RDTF combined with CaCO3 could promote osteosis and ameliorate bone loss to improve the repair of cracked bone trabeculae of OVX rats. Furthermore, RDTF combined with CaCO3 also could prevent OVX-induced decrease in collagen fibers in the femoral tissue of ovariectomized rats and promote the regeneration of new bone or cartilage tissue, while CaCO3 supplementation promoted the increase in bone mineral content. Nevertheless, there was no difference in the expression of Wnt3a, ß-catenin and p-ß-catenin between osteopenic rats and RDTF treated rats, but RDTF combined with CaCO3 could activate the Wnt3a/ß-catenin pathway. CONCLUSIONS: RDTF combined with CaCO3 could ameliorate estrogen deficiency-induced bone loss via the regulation of Wnt3a/ß-catenin pathway.

(-)-Epigallocatechin Gallate Promotes MicroRNA 145 Expression against Myocardial Hypoxic Injury through Dab2/Wnt3a/ß-catenin.

MicroRNA 145 (miR-145) is a critical modulator of cardiovascular diseases. The downregulation of myocardial miR-145 is followed by an increase in disabled-2 (Dab2) expression in cardiomyocytes. (-)-epigallocatechin gallate (EGCG) is a flavonoid that has been evaluated extensively due to its diverse pharmacological properties including anti-inflammatory effects. The aim of this study was to investigate the cardioprotective effects of EGCG under hypoxia-induced stress in vitro and in vivo. The hypoxic insult led to the suppression of miR-145 expression in cultured rat cardiomyocytes in a concentration-dependent manner. Western blotting and real-time PCR were performed. In rat myocardial infarction study, in situ hybridization, and immunofluorescent analyses were adopted. The western blot and real-time PCR data revealed that hypoxic stress with 2.5% O2 suppressed the expression of miR-145 and Wnt3a/ß-catenin in cultured rat cardiomyocytes but augmented Dab2. Treatment with EGCG attenuated Dab2 expression, but increased Wnt3a and ß-catenin in hypoxic cultured cardiomyocytes. Following in vivo myocardial infarction (MI) study, the data revealed the myocardial infarct area reduced by 48.5%, 44.6%, and 48.5% in EGCG (50mg/kg) or miR-145 dominant or Dab2 siRNA groups after myocardial infarction for 28 days, respectively. This study demonstrated that EGCG increased miR-145, Wnt3a, and ß-catenin expression but attenuated Dab2 expression. Moreover, EGCG ameliorated myocardial ischemia in vivo. The novel suppressive effect was mediated through the miR-145 and Dab2/Wnt3a/ß-catenin pathways.

[Curcumin inhibits proliferation,migration and invasion of gastric cancer cells via Wnt3a/ß-catenin/EMT signaling pathway].

The aim of this paper was to investigate the effects of curcumin on the proliferation,migration,invasion and apoptosis of human gastric cancer cells and to explore the potential mechanisms. SGC7901,MKN45 and NCI N87 cells lines were cultured under different concentrations of curcumin( 2. 5,5,10,20,40,80 and 160 µmol·L~(-1)) at different time points( 12,24,48 and 72 h),and the effect of curcumin on cell proliferation was detected by CCK-8 assay. The migration and invasiveness of cells were determined by wound healing and Transwell assays,the apoptosis rate was assessed by flow cytometry,the expression of N-cadherin,E-cadherin,snail1,Wnt3 a,p-ß-catenin,p-LRP6,Bcl-2 and Bax were detected by Western blot,and the enzymatic activity of caspase-3,caspase-8 and caspase-9 was evaluated via caspase kit. RESULTS:: indicated that the proliferation of MKN45 cells was significantly inhibited by curcumin in a dose-and time-dependent manner( IC50= 21. 93 µmol·L~(-1)). Moreover,curcumin could inhibit the migration and invasion of MKN45 cells,downregulate the expression of N-cadherin,snail1,Wnt3 a,p-ß-catenin,p-LRP6 and Bcl-2,and upregulate the expression of E-cadherin and Bax,it could increase the activity of caspase-3,caspase-8,caspase-9 and induce apoptosis as well. The potential mechanism is through inhibiting the Wnt3 a/ß-catenin/EMT pathway,regulating Bcl-2 signaling and caspase pathway,which might provide new potential strategies for gastric cancer treatment.

WNT3A accelerates delayed alveolar bone repair in ovariectomized mice.

Our goal was to evaluate alveolar bone healing in OVX mice, and to assess the functional utility of a WNT-based treatment to accelerate healing in mice with an osteoporotic-like bony phenotype. INTRODUCTION: Is osteoporosis a risk factor for dental procedures? This relatively simple question is exceedingly difficult to answer in a clinical setting, for two reasons. First, as an age-related disease, osteoporosis is frequently accompanied by age-related co-morbidities that can contribute to slower tissue repair. Second, the intervals at which alveolar bone repair are assessed in a clinical study are often measured in months to years. This study aimed to evaluate alveolar bone repair in ovariectomized (OVX) mice and provide preclinical evidence to support a WNT-based treatment to accelerate alveolar bone formation. METHODS: OVX was performed in young mice to produce an osteoporotic-like bone phenotype. Thereafter, the rate of extraction socket healing and osteotomy repair was assessed. A liposomal WNT3A treatment was tested for its ability to promote alveolar bone formation in this OVX-induced model of bone loss. RESULTS: Bone loss was observed throughout the murine skeleton, including the maxilla, and mirrored the pattern of bone loss observed in aged mice. Injuries to the alveolar bone, including tooth extraction and osteotomy site preparation, both healed significantly slower than the same injuries produced in young controls. Given sufficient time, however, all injuries eventually healed. In OVX mice, osteotomies healed significantly faster if they were treated with L-WNT3A. CONCLUSIONS: Alveolar bone injuries heal slower in OVX mice that exhibit an osteoporotic-like phenotype. The rate of alveolar bone repair in OVX mice can be significantly promoted with local delivery of L-WNT3A.

Pharmacological mechanism of Sishen Wan® attenuated experimental chronic colitis by inhibiting wnt/ß-catenin pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Sishen Wan (SSW) is a commercial and frequently used Chinese patent medicine listed in the Chinese Pharmacopeia, which is usually used to treat chronic colitis. AIM OF THE STUDY: We explored the pharmacological mechanism of Sishen Wan attenuated experimental chronic colitis by inhibiting Wnt/ß-catenin pathway. MATERIALS AND METHODS: Experimental chronic colitis was induced by trinitrobenzene sulfonic acid (TNBS). The therapeutic effect of SSW were analyzed by index of colonic weight, colonic length, pathological score. Cytokines expression were analyzed by ELISA, while the apoptosis level was checked by TUNEL staining. These proteins of Wnt/ß-catenin signaling pathway was analyzed by Western blot assay. RESULTS: Rats with TNBS-induced chronic colitis were treated by SSW for 10 days. The efficacy of SSW was demonstrated by improved macroscopic and microscopic colonic damage. SSW increased the level of ATP in colonic mucosa, while SSW inhibited ß-catenin, ubiquitination of Nemo-like-kinase-associated ring finger protein and T-cell factor, and expression of Wnt/ß-catenin downstream proteins (including c-Myc, cyclo-oxygenase-2, cyclin D1, survivin, signal transducer and activator of transcription 3 and zipper-interacting protein kinase), and improved lymphoid enhancer factor ubiquitination and ß-TrCP activity, followed by excessive apoptosis of colonic epithelial cells. CONCLUSIONS: SSW effectively attenuated experimental chronic colitis induced by TNBS, which was realized by inhibition of the Wnt/ß-catenin signaling pathway.

Inhibition of Wnt3a/FOXM1/ß-Catenin Axis and Activation of GSK3ß and Caspases are Critically Involved in Apoptotic Effect of Moracin D in Breast Cancers.

Although Moracin D derived from Morus alba was known to have anti-inflammatory and antioxidant activities, the underlying antitumor mechanism of Moracin D has not been unveiled thus far. Thus, in the recent study, the apoptotic mechanism of Moracin D was elucidated in breast cancer cells. Herein, Moracin D exerted significant cytotoxicity in MDA-MB-231 and MCF-7 cells. Furthermore, Moracin D increased sub G1 population; cleaved poly (Adenosine diphosphate (ADP-ribose)) polymerase (PARP); activated cysteine aspartyl-specific protease 3 (caspase 3); and attenuated the expression of c-Myc, cyclin D1, B-cell lymphoma 2 (Bcl-2), and X-linked inhibitor of apoptosis protein (XIAP) in MDA-MB231 cells. Of note, Moracin D reduced expression of Forkhead box M1 (FOXM1), ß-catenin, Wnt3a, and upregulated glycogen synthase kinase 3 beta (GSK3ß) on Tyr216 along with disturbed binding of FOXM1 with ß-catenin in MDA-MB-231 cells. Conversely, GSK3ß inhibitor SB216763 reversed the apoptotic ability of Moracin D to reduce expression of FOXM1, ß-catenin, pro-caspase3, and pro-PARP in MDA-MB-231 cells. Overall, these findings provide novel insight that Moracin D inhibits proliferation and induces apoptosis via suppression of Wnt3a/FOXM1/ß-catenin signaling and activation of caspases and GSK3ß.

Tannins from Syzygium guineense suppress Wnt signaling and proliferation of Wnt-dependent tumors through a direct effect on secreted Wnts.

Triple-negative breast cancer (TNBC) and colon cancer (CC) are two stigmatic examples of poorly treatable tumors, whose progression critically depends upon hyperactivation of the Wnt signaling. Development of specific anti-Wnt inhibitors is required to develop drugs against these and other Wnt-dependent cancers. Natural products, especially plants, have been used for the treatment of various diseases from ancient times. We examined extracts from several indigenous Cameroonian herbs and tested their effects on proliferation and Wnt signaling in TNBC and CC cells. Extracts from "fruit rouge", Syzygium guineense Wall. (Myrtaceae), demonstrated a strong activity against these cancer cells, as well as CC organoids. We found TNBC cells to significantly upregulate expression of Wnt3a, and the effects of S. guineense extracts on TNBC cell proliferation correlated with inhibition of the Wnt3a-induced ß-catenin stabilization and transcriptional response. HPLC analysis revealed that the active components belong to tannins. We found a direct destabilizing effect of S. guineense extract on Wnt3a and other Wnt proteins, identifying a novel mechanism of action of tannins on the Wnt signaling pathway and cancer cell proliferation. Being edible, this African plant may have an important cancer-preventive nutritional value.

[Low dose of triptolide ameliorates podocyte epithelial-mesenchymal transition induced by high dose of D-glucose via inhibiting Wnt3α/ß-catenin signaling pathway activation].

To explore the effects and molecular mechanisms of triptolide（TP）on improving podocyte epithelial-mesenchymal transition（EMT）induced by high dose of D-glucose（HG）, the immortalized podocytes of mice in vitro were divided into the normal group（N）, the high dose of D-glucose group（HG）, the low dose of TP group（L-TP）, the high dose of TP group（H-TP）and the mannitol group（MNT）, and treated by the different measures respectively. More specifically, the podocytes in each group were separately treated by D-glucose（DG, 5 mmol·L⁻¹ï¼‰or HG（25 mmol·L⁻¹ï¼‰or HG（25 mmol·L⁻¹ï¼‰+ TP（3 µg·L⁻¹ï¼‰or HG（25 mmol·L⁻¹ï¼‰+ TP（10 µg·L⁻¹ï¼‰or DG（5 mmol·L⁻¹ï¼‰+ MNT（24.5 mmol·L⁻¹ï¼‰. After the intervention for 24, 48 and 72 hours, firstly, the activation of podocyte proliferation was investigated. Secondly, the protein expression levels of the epithelial markers in podocytes such as nephrin and podocin, the mesenchymal markers such as desmin and collagen Ⅰ and the EMT-related mediators such as snail were detected respectively. Finally, the protein expression levels of Wnt3α and ß-catenin as the key signaling molecules in Wnt3α/ß-catenin pathway were examined severally. The results indicated that, HG could cause the low protein expression levels of nephrin and podocin and the high protein expression levels of desmin, collagen Ⅰ and snail in podocytes, and inducing podocyte EMT. On the other hand, HG could cause the high protein expression levels of Wnt3α and ß-catenin in podocytes, and activating Wnt3α/ß-catenin signaling pathway. In addition, L-TP had no effect on the activation of podocyte proliferation, the co-treatment of L-TP and HG could significantly recover the protein expression levels of nephrin and podocin, inhibit the protein expression levels of desmin, collagen I and snail in podocytes, thus, further improving podocyte EMT. And that, the co-treatment of L-TP and HG could obviously decrease the high protein expression levels of Wnt3α and ß-catenin induced by HG in podocytes, and inhibit Wnt3α/ß-catenin signaling pathway activation. On the whole, HG can induce podocyte EMT by activating Wnt3α/ß-catenin signaling pathway; L-TP can ameliorate podocyte EMT through inhibiting Wnt3α/ß-catenin signaling pathway activation, which may be one of the effects and molecular mechanisms in vitro.

[Effects of orchinol on invasion, migration and Wnt3a/ß-catenin signaling pathway of human gastric cancer SGC-7901 cells].

The purpose of this study was to investigate the inhibitory effect of the main 9,10-dihydrophenanthrene orchinol isolated from Spiranthes sinensis Radix et Herba on the invasion and migration of human gastric cancer SGC-7901 cells and its preliminary molecular mechanism. SGC-7901 cells were cultured in vitro, after the cells were treated with different final concentrations(5, 10, 20, 40, 80 µmol·L⁻¹) of orchinol for 24, 48 or 72 hours, the effect of orchinol on cell viability was measured by MTT assay. Wound healing and Transwell assays were performed to determine the effects of different final concentrations(5, 10, 20, 40 µmol·L⁻¹) of orchinol for 48 hour on invasion and migration abilities of SGC-7901 cells, respectively. The protein expression levels of ß-catenin, Wnt-3α, DvL2, cyclinD1 and GSK-3ß were detected by Western blot. The results showed that 5-80 µmol·L⁻¹ orchinol inhibited the viability of SGC-7901 cells in a dose-dependent and time-dependent manner, and the IC58 values of 24, 48 and 72 hours were 77.79, 42.96 and 7.85 µmol·L⁻¹, respectively. Compared with the control group, the ability of invasion and migration of SGC-7901 cells was significantly inhibited after treated with 5, 10 and 20 µmol·L⁻¹ orchinol for 48 hours (P<0.05, P<0.01), and the dose-effect relationship was observed. The results of Western blot showed that orchinol could significantly down-regulate the protein expression levels of ß-catenin, Wnt3a, DvL2 and cyclinD1, and up-regulate the protein expression level of GSK-3ß(P<0.05, P<0.01, P<0.001). The above results suggest that orchinol can obviously inhibit the invasion and migration of SGC-7901 cells, which may be related to its inhibition of Wnt3a/ß-catenin signaling pathway and the proteins expression of downstream genes.

Morinda citrifolia Leaf Extract Enhances Osteogenic Differentiation Through Activation of Wnt/ß-Catenin Signaling.

Morinda citrifolia (Noni) leaf is an herbal medicine with application in the domestic treatment of a broad range of conditions, including bone fracture and luxation. However, the basic mechanism underlying the stimulation of osteogenic differentiation by Noni leaf extract remains poorly understood. This study aimed to examine the effect of this extract on osteogenic differentiation and the mechanism by which Noni leaf extract enhances osteogenic differentiation. Aqueous extract of Noni leaves was prepared, and rutin and kaempferol-3-O-rutinoside were identified to be two of its major components. C2C12 and human periodontal ligament (hPDL) cells were used to study the effect of Noni. Noni did not show cytotoxicity at a concentration range of 0.015%-1.0% (w/v%) and significantly enhanced the activity of alkaline phosphatase (ALP) and expression levels of osteoblast differentiation markers, including Runx2, ALP, osterix, and osteocalcin, bone morphogenetic protein 2, Wnt3a, and ß-catenin. In addition, Noni enhanced the matrix mineralization of hPDL cells. In the signaling pathways, Noni increased the phosphorylation levels of Akt and GSK3ß and nuclear translocation and transcriptional activity of ß-catenin, which were attenuated by the addition of Dkk-1, a Wnt inhibitor, or LY294002, a PI3K inhibitor. These results suggest that Noni leaf extract enhances osteogenic differentiation through the PI3K/Akt-dependent activation of Wnt/ß-catenin signaling. Noni leaf extract might be a novel alternative medicine for bone and periodontal regeneration in patients with periodontal diseases.

Total Flavonoids of Drynariae Rhizoma Prevent Bone Loss Induced by Hindlimb Unloading in Rats.

Drynariae Rhizoma is a kidney-tonifying herb that has a long history in clinical practice for the treatment of bone fractures and joint diseases in China. Flavonoids are considered to be its major active ingredients and are reported to ease bone loss in ovariectomized rats. However, the beneficial effects of the total flavonoids of Drynariae Rhizoma on osteoporosis caused by microgravity or mechanical inactivity remain unknown. This study assessed the effects of total Drynariae Rhizoma flavonoids (DRTF, Qihuang, Beijing, China, national medicine permit No. Z20030007, number of production: 04080081, content of DRTF ≥80%) against bone loss induced by simulated microgravity. A hindlimb unloading tail-suspended rat model was established to determine the effect of DRTF on bone mineral density (BMD), biomechanical strength and trabecular bone microarchitecture. Twenty-eight male Sprague-Dawley rats were divided into four groups: the baseline, control, hindlimb unloading with vehicle (HLU), and hindlimb unloading treated with DRTF (HLU-DRTF, 75 mg/kg/day) groups. Oral DRTF was administered for 4 weeks. The underlying mechanisms of the DRTF actions on disuse-induced osteoporosis are discussed. The results showed that DRTF treatment significantly increased the BMD and mechanical strength of tail-suspended rats. Enhanced bone turnover markers with HLU treatment were attenuated by DRTF administration. Deterioration of trabecular bone induced by HLU was prevented through elevated bone volume/tissue volume (BV/TV), trabecular number (Tb. N), trabecular thickness (Tb. Th) and decreased trabecular separation (Tb. Sp). The present study provides the first evidence that DRTF prevents bone loss induced by HLU treatment, indicating its potential application in the treatment of disuse-induced osteoporosis.

Ginkgo biloba exocarp extracts inhibits angiogenesis and its effects on Wnt/ß-catenin-VEGF signaling pathway in Lewis lung cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: A fruit of Ginkgo biloba L. also known as Ginkgo biloba, can be used for the treatment of cancer in Chinese traditional medicine. The scientific name of succulent skin, which is the episperm of Ginkgo nuts, is exocarp. Experiment shows that Ginkgo biloba exocarp extracts (GBEE) has the effects of immune promotion, cancer inhibition and etc. AIM OF STUDY: Study on the activity of GBEE against Lewis lung cancer (LLC) angiogenesis and its partial molecular mechanism. MATERIALS AND METHODS: The effect of GBEE on proliferation of LLC cells was detected by MTT method in vitro. The metastasis model of LLC was set up. The C57BL/6J mice were randomly separated into normal control, model control, positive control and GBEE (50, 100, 200mg/kg) treatment groups, n=10. The mice in normal group and model group were both intragastric gavage (i.g.) normal saline (NS) in a volume of 0.1mL/10g (b.w.), positive group were intraperitoneal (i.p.) injection cyclophosphamide (CPA) at a dose of 20mg/kg (b.w.) , the GBEE treatment groups were respectively i.g. GBEE 50, 100, and 200mg/kg (b.w.), once a day for 20d. After treatment, we calculated the tumor inhibition rate and anti-metastasis rate. The microvessel density (MVD) was measured by immunohistochemistry method in transplanted tumor. The expression levels of vascular en-dothelial growth factor (VEGF) and VEGFR2 mRNA or Wnt3a, ß-catenin, VEGF, VEGFR2 and p-Akt/Akt protein expression were respectively tested by Quantitative Reverse transcription Polymerase chain reaction (qRT-PCR) or western blot in vitro and vivo. RESULTS: GBEE suppressed the growth of LLC cells in a dose-dependent way at the dose of 5, 10, 20, 40, 80 and 160µg/mL in vitro. It can suppressed Wnt3a and ß-catenin protein expression and the content of mRNA of VEGF and VEGFR2 in LLC cells significantly. In vivo, we discovered GBEE can retard the growth of LLC transplanted tumor in a dose-dependent way at the dose of 50, 100, 200mg/kg, suppressing tumor lung metastasis. The expression of CD34 was reduced, which means MVD was inhibited and so do ß-catenin, VEGF, VEGFR2 and p-AKT/AKT protein expression and VEGF and VEGFR2 mRNA expression levels in LLC transplanted tumor of C57BL/6 mice. CONCLUSIONS: GBEE played the effects of anti-tumor and anti-metastatic depending upon the inhibition of tumor angiogenesis, which may be closely relevant to its effect in blockage of Wnt /ß-catenin-VEGF signaling pathway in LLC.

Wnt5a Supports Osteogenic Lineage Decisions in Embryonic Stem Cells.

The specification of pluripotent stem cells into the bone-forming osteoblasts has been explored in a number of studies. However, the current body of literature has yet to adequately address the role of Wnt glycoproteins in the differentiation of pluripotent stem cells along the osteogenic lineage. During mouse embryonic stem cell (ESC) in vitro osteogenesis, the noncanonical WNT5a is expressed early on. Cells either sorted by their positive WNT5a expression or when supplemented with recombinant WNT5a (rWNT5a) during a 2-day window showed significantly enhanced osteogenic yield. Mechanistically, rWNT5a supplementation upregulated protein kinase C (PKC), calcium/calmodulin-dependent kinase II (CamKII) and c-Jun N-terminal kinase (JNK) activity while antagonizing the key effector of canonical Wnt signaling: ß-catenin. Conversely, when recombinant WNT3a (rWNT3a) or other positive regulators of ß-catenin were employed during this same time window there was a decrease in osteogenic marker expression. However, if rWNT3a was supplemented during a time window following rWNT5a treatment, osteogenic differentiation was enhanced both in murine and human ESCs. Elucidating the role of these WNT ligands in directing the early stages of osteogenesis has the potential to considerably improve tissue engineering protocols and applications for regenerative medicine.

Wnt3a upregulates brain-derived insulin by increasing NeuroD1 via Wnt/ß-catenin signaling in the hypothalamus.

BACKGROUND: Insulin plays diverse roles in the brain. Although insulin produced by pancreatic ß-cells that crosses the blood-brain barrier is a major source of brain insulin, recent studies suggest that insulin is also produced locally within the brain. However, the mechanisms underlying the production of brain-derived insulin (BDI) are not yet known. RESULTS: Here, we examined the effect of Wnt3a on BDI production in a hypothalamic cell line and hypothalamic tissue. In N39 hypothalamic cells, Wnt3a treatment significantly increased the expression of the Ins2 gene, which encodes the insulin isoform predominant in the mouse brain, by activating Wnt/ß-catenin signaling. The concentration of insulin was higher in culture medium of Wnt3a-treated cells than in that of untreated cells. Interestingly, neurogenic differentiation 1 (NeuroD1), a target of Wnt/ß-catenin signaling and one of transcription factors for insulin, was also induced by Wnt3a treatment in a time- and dose-dependent manner. In addition, the treatment of BIO, a GSK3 inhibitor, also increased the expression of Ins2 and NeuroD1. Knockdown of NeuroD1 by lentiviral shRNAs reduced the basal expression of Ins2 and suppressed Wnt3a-induced Ins2 expression. To confirm the Wnt3a-induced increase in Ins2 expression in vivo, Wnt3a was injected into the hypothalamus of mice. Wnt3a increased the expression of NeuroD1 and Ins2 in the hypothalamus in a manner similar to that observed in vitro. CONCLUSION: Taken together, these results suggest that BDI production is regulated by the Wnt/ß-catenin/NeuroD1 pathway in the hypothalamus. Our findings will help to unravel the regulation of BDI production in the hypothalamus.

Electroacupuncture stimulation at CV4 prevents ovariectomy-induced osteoporosis in rats via Wnt-ß-catenin signaling.

The present study aimed to investigate the effect of electroacupuncture stimulation at CV4 (also termed Guanyuan) on femoral osteocalcin also termed bone gla protein (BGP), alkaline phosphatase (ALP), bone mineral density (BMD) and biomechanics, as well as the Wnt­ß­catenin signaling pathway in rats with postmenopausal osteoporosis. Female Sprague­Dawley rats (4.5­months old) were randomly divided into sham, Ovx, CV4 and mock groups (n=10/group). With the exception of those in the sham group, the rats were ovariectomized to induce postmenopausal osteoporosis. The rats in the CV4 and mock groups were given electroacupuncture at CV4 and non­acupoint, respectively. The rats in the Ovx model and sham groups underwent identical fixing procedures, but did not undergo electroacupuncture. Following treatment, hematoxylin and eosin staining was used to observe morphological changes in the left femoral trabecular bone, and a three­point­bending test was used to analyze femur biomechanics and determine the BMD. In addition, an enzyme­linked immunosorbent assay was used to measure the serum levels of ALP/BGP and reverse transcription­quantitative polymerase chain reaction was used detect the expression levels of Wnt3a, ß­catenin and Runx2. In the present study, it was demonstrated that electroacupuncture at CV4 significantly improved the osteoporotic morphological changes that occurred in the ovariectomized rats, increased serum ALP and BGP levels, enhanced the maximum and fracture loads, increased BMD (P<0.01), and activated the Wnt­ß­catenin signaling pathway. These findings demonstrated that electroacupuncture stimulation at CV4 affected bone formation and promoted bone metabolism in rats with postmenopausal osteoporosis, possibly by activating the Wnt­ß­catenin signaling pathway.

Effects of acupuncture on cortical expression of Wnt3a, ß-catenin and Sox2 in a rat model of traumatic brain injury.

OBJECTIVE: To observe the effects of acupuncture treatment on the expression of Wnt/ß-catenin signalling pathway-related genes (Wnt3a, ß-catenin and Sox2) in the injured cerebral cortex of rats with traumatic brain injury (TBI). METHODS: A controlled impact model of TBI was established using Feeney's free-drop method. Seventy-eight Sprague-Dawley rats were randomly divided into the following three groups: a normal group (n=18) that was left untreated; a model group (n=30) that received no treatment after TBI; and an acupuncture group (n=30) that received acupuncture (at LI4, GV20, GV26 and GV16) after TBI. Rats in each group were randomly and equally divided into 3-day, 7-day and 14-day subgroups according to the duration of therapy. Real-time fluorescence quantitative PCR (RT-qPCR) was used to measure mRNA expression of Wnt3a, ß-catenin and Sox2. Western blots were performed to determine the expression levels of WNT3a, ß-Catenin and SOX2. RESULTS: Wnt3a mRNA was upregulated in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.05). ß-catenin expression was significantly increased in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.01). In the 3-day and 7-day acupuncture subgroups, Sox2 expression was significantly higher than that in the normal and model groups (p<0.01 each). The levels of WNT3a, ß-catenin and SOX2 were generally consistent with the corresponding mRNA levels. CONCLUSIONS: Acupuncture exerts a regulatory effect on the Wnt/ß-catenin signalling pathway, which may in turn influence the proliferation and differentiation of endogenous neural stem cells.

Cost-effective differentiation of hepatocyte-like cells from human pluripotent stem cells using small molecules.

Significant efforts have been invested into the differentiation of stem cells into functional hepatocyte-like cells that can be used for cell therapy, disease modeling and drug screening. Most of these efforts have been concentrated on the use of growth factors to recapitulate developmental signals under in vitro conditions. Using small molecules instead of growth factors would provide an attractive alternative since small molecules are cell-permeable and cheaper than growth factors. We have developed a protocol for the differentiation of human embryonic stem cells into hepatocyte-like cells using a predominantly small molecule-based approach (SM-Hep). This 3 step differentiation strategy involves the use of optimized concentrations of LY294002 and bromo-indirubin-3'-oxime (BIO) for the generation of definitive endoderm; sodium butyrate and dimethyl sulfoxide (DMSO) for the generation of hepatoblasts and SB431542 for differentiation into hepatocyte-like cells. Activin A is the only growth factor required in this protocol. Our results showed that SM-Hep were morphologically and functionally similar or better compared to the hepatocytes derived from the growth-factor induced differentiation (GF-Hep) in terms of expression of hepatic markers, urea and albumin production and cytochrome P450 (CYP1A2 and CYP3A4) activities. Cell viability assays following treatment with paradigm hepatotoxicants Acetaminophen, Chlorpromazine, Diclofenac, Digoxin, Quinidine and Troglitazone showed that their sensitivity to these drugs was similar to human primary hepatocytes (PHHs). Using SM-Hep would result in 67% and 81% cost reduction compared to GF-Hep and PHHs respectively. Therefore, SM-Hep can serve as a robust and cost effective replacement for PHHs for drug screening and development.

Soybean isoflavone treatment induces osteoblast differentiation and proliferation by regulating analysis of Wnt/ß-catenin pathway.

It has been reported that soybean isoflavones (SI) have anti-bone resorptive activity in vivo. However, little is known about the cellular and molecular mechanisms of this effect. In this study, we investigated the effects of SI on osteoblast differentiation and proliferation. Results showed that SI promoted osteoblast proliferation and differentiation which could be marked as the formation of hydroxyapatite crystals or extracellular matrix and increased ALP level. SI treatment markedly decreased RANKL levels and increased OPG levels in osteoblast cells. SI resulted in activation of the Wnt/ß-catenin pathway. These results demonstrate that SI may be a useful remedy for the treatment of osteoporosis.

Effects of Two Different Rhodiola rosea Extracts on Primary Human Visceral Adipocytes.

Rhodiola rosea (Rro) has been reported to have various pharmacological properties, including anti-fatigue, anti-stress and anti-inflammatory activity. It is also known to improve glucose and lipid metabolism, but the effects of Rhodiola rosea on adipocyte differentiation and metabolism are not still elucidated. In this study the anti-adipogenic and lipolytic activity of two extracts of Rhodiola rosea, containing 3% salidroside (RS) or 1% salidroside and 3% rosavines (RR) on primary human visceral adipocytes was investigated. Pre-adipocytes were analyzed after 10 and 20 days of treatment during differentiation and after 7 days of treatment when they reached mature shape. The RS extract significantly induced higher apoptosis and lipolysis in comparison to control cells and to RR extract. In contrast, RR extract significantly reduced triglyceride incorporation during maturation. Differentiation of pre-adipocytes in the presence of RS and RR extracts showed a significant decrease in expression of genes involved in adipocyte function such as SLC2A4 and the adipogenic factor FGF2 and significant increase in expression of genes involved in inhibition of adipogenesis, such as GATA3, WNT3A, WNT10B. Furthermore RR extract, in contrast to RS, significantly down-regulates PPARG, the master regulator of adipogenesis and FABP4. These data support the lipolytic and anti-adipogenetic activity of two different commercial extracts of Rhodiola rosea in primary human visceral pre-adipocytes during differentiation.