[Epidemiological and clinicopathological characteristics of prostate cancer in Hunan].

OBJECTIVE: To investigate the epidemiological and clinicopathological characteristics of PCa and provide some strategies for the clinical prevention and treatment of the malignancy. METHODS: This study included 1 594 cases of pathologically diagnosed PCa after radical prostatectomy in Xiangya Hospital of Central South University from January 1, 2010 to December 31, 2020. We collected the basic information about the patients, their main complaints and clinicopathological results, and analyzed the epidemiological and clinicopathological data. RESULTS: The patients were aged from 28 to 93 years, and the number of PCa cases showed an overall upward trend from 2010 to 2020. Urinary system symptoms were most common (62.53%) as initial symptoms, followed by increased PSA (17.82%), PCa, prostate nodule, prostate mass (8.43%) and bone metastasis (2.94%) found at physical examinations, and the cases of PSA elevation among the clinic visitors increased year by year from 2010 to 2020. Gleason score 7 was found in a largest proportion of the PCa patients, and adenocarcinoma was the main pathological type (78.6%). Logistic regression analysis showed that high Gleason score, instead of age and expressions of Ki67, AR and ERG, was an independent risk factor for intraductal carcinoma. CONCLUSION: The incidence of PCa shows an increasing trend, and is more common in those over 50 years old. PSA screening is gradually popularized in China. Intraductal carcinoma, as a major risk factor for aggressive PCa and poor prognosis of the malignancy, is significantly correlated with high Gleason scores.

[Quercetin for the treatment of prostate cancer: Progress in studies].

Prostate cancer (PCa) is a common urinary malignancy, and advanced PCa has a poor prognosis and a high mortality. Drug therapies currently available for this malignancy often cause serious adverse reactions, and therefore new drugs with fewer adverse effects or the potential to reduce the adverse effects of traditional chemotherapeutic drugs are badly needed for the management of PCa. Quercetin, as a natural flavonoid, has been extensively studied in recent years for its anti-cancer effects, as in cell signal transduction, apoptosis promotion, anti-proliferation and -oxidation, and growth inhibition. In fact, quercetin has a variety of biological effects and can inhibit various enzymes involved in cell proliferation and signal transduction pathways. Besides, quercetin is also reported to have potential synergistic effects when used in combination with radiotherapy or chemotherapeutic drugs. This review summarizes the advances in the treatment of PCa with quercetin, focusing on its effects of promoting the apoptosis, inhibiting the proliferation and reducing the invasiveness and migration of tumor cells, and reversing drug resistance, aiming to provide a new theoretical basis and some new ideas for the studies of the treatment of PCa.

Genomic Identification and Functional Analysis of JHAMTs in the Pond Wolf Spider, Pardosa pseudoannulata.

Juvenile hormone (JH) plays a critical role in many physiological activities of Arthropoda. Juvenile hormone acid methyltransferase (JHAMT) is involved in the last steps of JH biosynthesis as an important rate-limiting enzyme. In recent studies, an increasing number of JHAMTs were identified in arthropods, but no JHAMT was reported in spiders. Herein, eight JHAMTs were identified in the pond wolf spider, Pardosa pseudoannulata, all containing the well conserved S-adenosyl-L-methionine binding motif. JHAMT-1 and the other seven JHAMTs were located at chromosome 13 and chromosome 1, respectively. Multiple alignment and phylogenetic analysis showed that JHAMT-1 was grouped together with insect JHAMTs independently and shared high similarities with insect JHAMTs compared to the other seven JHAMTs. In addition, JHAMT-1, JHAMT-2, and JHAMT-3 were highly expressed in the abdomen of spiderlings and could respond to the stimulation of exogenous farnesoic acid. Meanwhile, knockdown of these three JHAMTs caused the overweight and accelerated molting of spiderlings. These results demonstrated the cooperation of multi-JHAMTs in spider development and provided a new evolutionary perspective of the expansion of JHAMT in Arachnida.

miR-155 facilitates calcium oxalate crystal-induced HK-2 cell injury via targeting PI3K associated autophagy.

Nephrolithiasis is one of the most common and highly recurrent diseases worldwide. Accumulating evidence revealed the elevated miR-155 levels both in serum and urine of nephrolithiasis patients. The aim of our research was to explore the role of miR-155 in CaOx-induced apoptosis in HK-2 cells. The expression levels of miR-155 in serum and renal tissues were quantified in 20 patients with nephrolithiasis using qRT-PCR assay. ELISA was performed to determine urinary levels of interleukin (IL)-1ß, IL-6 and tumor necrosis factor-alpha (TNF-α). Renal tubular cell model of CaOx nephrolithiasis was established to investigate the role and molelular mechanism of miR-155. Cell viability and apoptosis were assessed by MTT and flow cytometry, respectively. Immunofluoresent staining of LC3 autophagosome and western blotting were performed to evaluate the autophagic activity. Luciferase reporter assay was employed to verify the interaction between miR-155 and PI3KCA/Rheb. PI3K/Akt/mTOR signaling was further examined by western blotting. Serum and renal levels of miR-155 and inflammatory factors were significantly elevated in nephrolithiasis patients than in controls. CaOx treatment caused up-regulation of miR-155 and induced autophagy in renal tubular epithelial cells, while silencing miR-155 or inhibition of autophagy by 3-metheladenine (3-MA) ameliorated CaOx crystal-induced cell injury. PI3KCA and Rheb was identified as downstream targets of miR-155. Moreover, miR-155 activates autophagy and promotes cell injury through repressing PI3K/Akt/mTOR signaling pathway. Taken together, these findings demonstrated that miR-155 facilitates CaOx crystal-induced renal tubular epithelial cell injury via PI3K/Akt/mTOR-mediated autophagy, providing therapeutic targets for ameliorating cellular damage by CaOx crystals.

Efficacy and safety of stem cell therapy in patients with dilated cardiomyopathy: a systematic appraisal and meta-analysis.

BACKGROUND: The clinical significance of stem cell therapy in the treatment of dilated cardiomyopathy remains unclear. This systemic appraisal and meta-analysis aimed to assess the efficacy and safety of stem cell therapy in patients with dilated cardiomyopathy. After searching the PubMed, Embase, and Cochrane library databases until November 2017, we conducted a meta-analysis to evaluate the efficacy and safety of stem cell therapy in patients with dilated cardiomyopathy. METHODS: The weighted mean difference (WMD), standard mean difference (SMD), relative risk (RR), and 95% confidence interval (CI) were summarized in this meta-analysis. Both fixed effects and random effects models were used to combine the data. Sensitivity analyses were conducted to evaluate the impact of an individual dataset on the pooled results. RESULTS: A total of eight randomized controlled trials, which involved 531 participants, met the inclusion criteria in this systematic appraisal and meta-analysis. Our meta-analysis showed that stem cell therapy improves left ventricular ejection fraction (SMD = 1.09, 95% CI 0.29 to 1.90, I2 = 92%) and reduces left ventricular end-systolic volume (SMD = - 0.36, 95% CI - 0.61 to - 0.10, I2 = 20.5%) and left ventricular end-diastolic chamber size (SMD = - 0.48, 95% CI - 0.89 to - 0.07, I2 = 64.8%) in patients with dilated cardiomyopathy. However, stem cell therapy has no effect on mortality (RR = 0.72, 95% CI 0.50 to 1.02, I2 = 30.2%) and 6-min-walk test (WMD = 51.52, 95% CI - 24.52 to 127.55, I2 = 94.8%). CONCLUSIONS: This meta-analysis suggests that stem cell therapy improves left ventricular ejection fraction and reduces left ventricular end-systolic volume and left ventricular end-diastolic chamber size in patients with dilated cardiomyopathy. However, future well-designed large studies might be necessary to clarify the effect of stem cell therapy in patients with dilated cardiomyopathy.

LOX­1 is implicated in oxidized low­density lipoprotein­induced oxidative stress of macrophages in atherosclerosis.

Induction of oxidative stress has a causal role in atherosclerosis. The aim of the present study was to examine the role of lectin­like oxidized low­density lipoprotein receptor­1 (LOX­1) in oxidized low­density lipoprotein (OxLDL)­induced oxidative stress in atherosclerosis. Small interfering RNA (siRNA) technology was employed to decrease the expression of LOX­1 in mouse RAW264.7 macrophages and the effects of LOX­1 silencing on OxLDL­induced reactive oxygen species (ROS) generation and NADPH oxidase (NOX) expression were investigated. The in vivo effects of reducing LOX­1 were also examined in a mouse model (ApoE­/­) of high­fat diet­induced atherosclerosis. Compared with the control cells, OxLDL exposure led to a significant (P<0.05) increase in the intracellular levels of malondialdehyde and ROS and a significant decrease in the activity of superoxide dismutase. Delivery of LOX­1­targeting siRNA significantly (P<0.05) reversed the alterations in oxidative stress parameters induced by OxLDL. LOX­1 silencing downregulated the expression of NOX2, Rac1, p47phox and p22phox and impaired the activation of mitogen­activated protein kinases in OxLDL­treated cells. Adenoviral delivery of LOX­1 siRNA caused a significant increase in the size of the fibrous cap and a decrease in the macrophage content in lesions, compared with the control mice. Western blot analysis demonstrated that the protein expression levels of NOX1, Rac1, p47phox and p22phox in aortic lesions were significantly lower in the LOX­1 siRNA group than in the control group. LOX­1 is implicated in OxLDL­induced oxidative stress of macrophages in atherosclerosis, which in part, involves the regulation of NADPH oxidases.

Angiotensin-(1-7) stimulates cholesterol efflux from angiotensin II-treated cholesterol-loaded THP-1 macrophages through the suppression of p38 and c-Jun N-terminal kinase signaling.

Angiotensin II (Ang II) and Ang-(1-7) are key effector peptides of the renin-angiotensin system. The present study aimed to investigate the effects of Ang-(1-7) on Ang II-stimulated cholesterol efflux and the associated molecular mechanisms. Differentiated THP-1 macrophages were treated with Ang II (1 µM) and/or Ang-(1-7) (10 and 100 nM) for 24 h and the cholesterol efflux and gene expression levels were assessed. Pharmacological inhibition of peroxisome proliferator-activated receptor (PPAR)γ and mitogen-activated protein kinases (MAPKs) were performed to identify the signaling pathways involved. The results demonstrated that Ang II significantly inhibited the cholesterol efflux from cholesterol-loaded THP-1 macrophages. Treatment with Ang-(1-7) led to a dose-dependent restoration of cholesterol efflux in the Ang II-treated cells. The co-treatment with Ang-(1-7) and Ang II significantly increased the expression levels of adenosine triphosphate (ATP)-binding cassette (ABC)A1 and ABCG1 compared with treatment with Ang II alone. This was coupled with increased expression levels of PPARγ and liver X receptor (LXR)α. The pharmacological inhibition of PPARγ significantly (P<0.05) eliminated the Ang-(1-7)-mediated induction of ABCA1 and ABCG1 mRNA expression. Treatment with Ang-(1-7) caused the inactivation of c-Jun N-terminal kinases (JNK) and p38 MAPK signaling in the Ang II-treated THP-1 macrophages. In addition, the inhibition of JNK or p38 MAPK signaling using specific pharmacological inhibitors mimicked the Ang-(1-7)-induced expression of PPARγ and LXRα. In conclusion, the data demonstrated that treatment with Ang-(1-7) promoted cholesterol efflux in Ang II-treated THP-1 macrophages, partly through inactivation of p38 and JNK signaling and by inducing the expression of PPARγ and LXRα. Ang (1-7) may, therefore, have therapeutic benefits for the treatment of atherosclerosis.

Tissue-engineered ribs for chest wall reconstruction: a case with 12-year follow-up.

We hereby report on a case in which a huge chest wall defect generated by resection of a massive aggressive tumor (desmoplastic fibroma) was repaired with osteogenic-induced mesenchymal stem cells embedded in a bone-derived biomaterial. In this case, there were three challenges to overcome: reconstruction of the soft tissue, repair of the skeletal defect of the thoracic wall and repair of the defect in the pleural cavity. The defects of soft tissue and pleural cavity were reconstructed, respectively, with an ipsilateral abdominal flap and a diaphragm muscular flap. The huge defect in the chest wall was successfully repaired with the tissue-engineered ribs, which was confirmed by long-term follow-up with computerized tomography and histological and immunohistochemical evaluations. In view of its effectiveness and safety, tissue-engineered bones may have a broad application for the repair of large skeletal defects and bone regeneration.

Tissue engineered esophagus scaffold constructed with porcine small intestinal submucosa and synthetic polymers.

Acellular porcine small intestinal submucosa (SIS) has been successfully used for reconstructing esophagus with half circumferential defects. However, repairing full circumferential esophageal defects with SIS has been restricted due to the latter's poor mechanical properties. In the present study, synthetic polyesters biomaterial poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(lactide-co-glycolide) (PLGA) have been used to improve the mechanical properties of SIS. Feasibility of SIS/PHBHHx-PLGA composite material scaffold for esophageal tissue engineering has been assessed through a series of testing. The appropriate mixing ratio of PHBHHx and PLGA polymers has been determined as 5:5 by mechanical testing and in vitro degradation experiment. The morphology of constructed membranous and tubular scaffolds was also characterized. As confirmed by enzyme-linked immunosorbent assay, the contents of VEGF and TGF-ß have respectively reached 657 ± 18 ng mL(-1) and 130 ± 4 pg mL(-1) within the SIS/PHBHHx-PLGA specimens. Biocompatibility of the SIS/PHBHHx-PLGA specimens with rat bone marrow mesenchymal stem cells (MSCs) was also evaluated by scanning electron microscopy and a live-dead cell viability assay. Actin filaments of MSCs on the composite materials were labeled. Biological safety of the extract from SIS/PHBHHx-PLGA specimens, measured as hemolysis rate, was all lower than 5%. Compared with SIS and SIS/PHBHHx-PLGA specimens, inflammatory reaction provoked by the PHBHHx-PLGA specimens in rats was however more severe. Our results have suggested that SIS/PHBHHx-PLGA composite material can offer a new approach for esophageal tissue engineering.

Neuroprotective effects of extract of Acanthopanax senticosus harms on SH-SY5Y cells overexpressing wild-type or A53T mutant α-synuclein.

Extract of Acanthopanax senticosus harms (EAS) has been shown to have neuroprotective effects on dopaminergic neurons in Parkinson's disease (PD) mice model. α-Synuclein is a key player in the pathogenesis of PD, the elevated level of which is deleterious to dopaminergic neurons, and enhancing its clearance might be a promising strategy for treating PD. To assess the potential of EAS in this regard, we investigated its effect on the SH-SY5Y cells overexpressing wild-type α-synuclein (WT-α-Syn) or A53T mutant α-synuclein (A53T-α-Syn), and the implicated pathway it might mediate. After treatment with EAS, the changes of α-synuclein, caspase-3, parkin, phospho-protein kinase B (Akt), phospho-glycogen synthase kinase 3 beta (GSK3ß), and phospho-microtubule-associated protein tau (Tau) in WT-α-Syn or A53T-α-Syn transgenic cells were reverted back to near normal levels, demonstrated by the western blotting and quantitative real-time PCR outcomes. The neuroprotective effects of EAS may be able to protect WT-α-Syn or A53T-α-Syn transgenic SH-SY5Y cells from α-synuclein overexpression and toxicity. Therefore, we speculate that EAS might be a promising candidate for prevention or treatment of α-synuclein-related neurodegenerative disorders such as PD.

Angiogenesis effect of therapeutic ultrasound on ischemic hind limb in mice.

Although significant progress in bypass surgery and catheter intervention against peripheral artery disease, the number of severe critical limb ischemia (CLI) patients is increasing. Thus, it is crucial to develop new, non-invasive therapeutic strategies. The purpose of this study was to determine the mechanism of therapeutic ultrasound (TUS) on ischemic angiogenesis using mouse model of hindlimb ischemia and the cellular/molecular mechanisms underlying TUS-related neovascularization. The hindlimb ischemic mice were exposed to extracorporeal TUS for 3, 6, 9 minute per day (1 MHz, 0.3 W/cm(2)) until day 14 after left femoral artery ligation. Increased blood perfusion and capillary density were determined following 9 min of TUS compared with ischemic group. Moreover, TUS treatment increased the protein levels of vascular endothelial growth factor (VEGF), hypoxic inducible factor-1α (HIF-1α), endothelial nitric oxide synthase (eNOS) and p-Akt in vivo. TUS promoted capillary-like tube formation, migration and motility of human umbilical venous endothelial cells (HUVECs). Furthermore, the protein expressions of VEGF, eNOS and p-Akt were increased after TUS treatment. In conclusion, TUS therapy promotes postnatal neovascularization through multiple angiogenic pathways in mice model of ischemic hindlimb.

Species variation in the spontaneous calcification of bone marrow-derived mesenchymal stem cells.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) hold great promise for tissue regeneration. With increasing numbers of clinical trials, the safety of BM-MSCs attracts great interest. Previously, we determined that rat BM-MSCs possessed spontaneous calcification without osteogenic induction after continuous culture. However, it is unclear whether BM-MSCs from other species share this characteristic. In this study, spontaneous calcification of BM-MSCs from rat, goat, and human specimens was investigated in vitro. BM-MSCs were cultured in complete medium, and calcification was determined by morphologic observation and alizarin red staining. It was demonstrated that rat BM-MSCs possessed a typically spontaneous calcification, whereas goat and human BM-MSCs under the same system proliferated significantly but did not calcify spontaneously. The significant species variation in spontaneous calcification of BM-MSCs described in this study provides useful information regarding evaluation of numerous BM-MSC-based approaches for bone regeneration and the safety of BM-MSCs.

Tissue engineered esophagus by mesenchymal stem cell seeding for esophageal repair in a canine model.

PURPOSE: Acellular porcine small intestinal submucosa (SIS) has been successfully used for esophagoplasty in dogs. However, this has not led to complete epithelialization and muscular regeneration. We undertook the present study to assess the effect of tissue-engineered esophagus generated by seeding bone marrow mesenchymal stem cells (BMSCs) onto an SIS scaffold (BMSCs-SIS) in a canine model. METHODS: We cultured, passaged, and measured autologous BMSCs and myoblasts with cell proliferation and immunohistochemical assays. We labeled the third passage of BMSCs with PKH-26, a fluorescent dye, before seeded it onto the SIS. We resected canine cervical esophagus to generate a defect 5 cm in length and 50% in circumference, which we repaired with BMSCs-SIS or SIS alone. RESULTS: Four weeks later, barium esophagram demonstrated that esophageal lumen surface of the patch graft was smoother in the BMSCs-SIS group compared with the SIS group. Histological examination suggested a strong similarity between BMSCs and esophageal myoblasts in terms of morphology and function. Although both BMSCs-SIS and SIS repaired the esophageal defects, we noted complete re-epithelialization with almost no inflammation only in the former group. By 12 wk after the surgery, we observed long bundles of skeletal muscles only in the BMSCs-SIS group, where the microvessel density was also much greater. CONCLUSIONS: Bone marrow mesenchymal stem cells on an SIS scaffold can promote re-epithelialization, revascularization, and muscular regeneration. This approach may provide an attractive option for esophageal regeneration.

Angiotensin-(1-7) treatment ameliorates angiotensin II-induced apoptosis of human umbilical vein endothelial cells.

Angiotensin (Ang)-(1-7), a metabolite of AngI and AngII, is a counter-regulatory mediator of AngII. In the present study, we investigated the effects of Ang-(1-7) on AngII-induced apoptosis in human umbilical vein endothelial cells (HUVEC). To this end, HUVEC were pretreated with 10(-9), 10(-8), 10(-7) or 10(-6) mol/L Ang-(1-7) at for 30 min before being stimulated with 10(-6) mol/L Ang-II for another 24 h. Acridine orange/ethidium bromide and propidium iodide staining were used to analyse the effects of Ang-(1-7) on AngII-induced apoptosis. Alone, 10(-6) mol/L Ang-(1-7) had no effect on the apoptosis of HUVEC following exposure of cells for 30 min, whereas AngII (10(-6) mol/L, 24 h) significantly enhanced the number of apoptotic cells (P < 0.01). The AngII-induced apoptosis of HUVEC was suppressed by 10(-9)-10(-6) mol/L Ang-(1-7). The anti-apoptotic effects of Ang-(1-7) were almost completely abolished by A-779 (10(-6) mol/L, 30 min), a specific Mas receptor antagonist. In addition, Ang-(1-7) inhibited AngII-induced accumulation of cleaved caspase 3 and enhanced the expression of the anti-apoptotic factor Bcl-2 at both the mRNA and protein levels. Angiotensin II upregulated the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), which is involved in endothelial apoptosis, at both the mRNA and protein levels. This effect was blocked by Ang-(1-7) in a concentration-dependent manner, although A-779 almost completely reversed Ang-(1-7)-mediated inhibition of AngII-induced upregulation of LOX-1. Silencing of LOX-1 using short interference RNA enhanced the protective effects of Ang-(1-7) against AngII-induced apoptosis in HUVEC. Together, the results suggest that Ang-(1-7) ameliorates AngII-induced apoptosis of HUVEC at least in part by suppressing LOX-1 expression.

The poor osteoinductive capability of human acellular bone matrix.

Demineralized bone matrix (DBM) has extensive clinical use for bone regeneration because of its osteoinductive and osteoconductive aptitude. It is suggested that the demineralization process in bone matrix preparation is influential in maintaining osteoinductivity; however, relevant investigations, especially into the osteoinductivity of acellular bone matrix, are not often performed. This study addressed the osteoinductive capability of human acellular cancellous bone matrix (ACBM) after subcutaneous implantation in a rat model. The growth and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) seeded in this material were also studied. Without the demineralization process, the ACBM we obtained had an interconnected porous network and the micropores in the surface were clearly exposed. After the ACBM was subcutaneously implanted for 4 months, new osteoid formation was noted but not typical mature bone formation. rBM-MSCs grew well in the ACBM and kept a steady morphology after continuous culture for 28 days. However, no mineralized nodule formation was detected and the expression levels of genes encoding osteogenic markers were significantly decreased. These results demonstrated that human ACBM possess the structural features of native bone and poor osteoinductivity; nonetheless this material helped to preserve the undifferentiated phenotype of rBM-MSCs. Such insights may further broaden our understanding of the application of ACBM for bone regeneration and the creation of stem cell niches.

Placenta- versus bone-marrow-derived mesenchymal cells for the repair of segmental bone defects in a rabbit model.

Tissue-engineered bones (TEBs) constructed with bone-marrow-derived mesenchymal stem cells (BMSCs) seeded on biomaterial scaffolds have achieved good results for bone defect repair in both animal experiments and clinical trials. This has been limited, however, by the source and quantity of BMSCs. We here explored TEBs constructed by placenta-derived mesenchymal stem cells (PMSCs) and compared their effect for the repair of critical-sized segmental osteoperiosteal defects with TEBs constructed with BMSCs. PMSCs were isolated from rabbit placenta by gradient centrifugation and in vitro monolayer culturing, and BMSCs were isolated from the hindlimb bone marrow of newborn rabbit. Primary cultured PMSCs and BMSCs were uniformly in a spindle shape. Immunocytochemistry indicated that both types of cells are positive for CD44 and CD105, and negative for CD34 and CD40L, confirming that they are mesenchymal stem cells. BrdU-labeled PMSCs and BMSCs were respectively co-cultured with bio-derived bone materials to construct TEBs in vitro. Critical-sized segmental osteoperiosteal defects of radii were created in 24 rabbits by surgery. The defects were repaired with TEBs constructed with PMSCs and BMSCs. The results showed that TEBs constructed by both PMSCs and BMSCs could repair the osteoperiosteal defects in a 'multipoint' manner. Measurement of radiography, histology, immunohistochemistry, alkaline phosphatase activity, osteocalcin assaying and biomechanical properties have found no significant difference between the two groups at 2, 4, 8 and 12 weeks after the transplantation (P > 0.05). Taken together, our results indicate that PMSCs have similar biological characteristics and osteogenic capacity to BMSCs and can be used as a new source of seeding cells for TEBs.

Synthesis and characterization of injectable, thermosensitive, and biocompatible acellular bone matrix/poly(ethylene glycol)-poly (ε-caprolactone)-poly(ethylene glycol) hydrogel composite.

In orthopedic tissue engineering, the extensively applied acellular bone matrix (ABM) can seldom be prefabricated just right to mold the cavity of the diverse defects, might induce severe inflammation on account of the migration of small granules and usually bring the patients great pain in the treatment. In this study, a new injectable thermosensitive ABM/PECE composite with good biocompatibility was designed and prepared by adding the ABM granules into the triblock copolymer poly(ethylene eglycol)-poly(ε-caprolactone)-poly(ethylene eglycol) (PEG-PCL-PEG, PECE). The PECE was synthesized by ring-opening copolymerization and characterized by ¹H NMR. The ABM was prepared by acellular treatment of natural bone and ground to fine granules. The obtained ABM/PECE composite showed the most important absorption bands of ABM and PECE copolymer in FT-IR spectroscopy and underwent sol-gel phage transition from solution to nonflowing hydrogel at 37°C. SEM results indicated that the ABM/PECE composite with different ABM contents all presented similar porous 3D structure. ABM/PECE composite presented mild cytotoxicity to rat MSCs in vitro and good biocompatibility in the BALB/c mice subcutis up to 4 weeks. In conclusion, all the results confirmed that the injectable thermosensitive ABM/PECE composite was a promising candidate for orthopedic tissue engineering in a minimally-invasive way.

Breast tissue image classification based on Semi-supervised Locality Discriminant Projection with Kernels.

Breast tissue classification is an important and effective way for computer aided diagnosis of breast cancer. We present Semi-supervised Locality Discriminant Projections with Kernels for breast cancer classification. The contributions of this work lie in: 1) Semi-supervised learning is used into Locality Preserving Projections (LPP) to enhance its performance using side-information together with the unlabelled training samples, while current algorithms only consider the side-information but ignoring the unlabeled training samples. 2) Kernel trick is applied into Semi-supervised LPP to improve its ability in the nonlinear classification. 3) The framework of breast cancer classification with Semi-supervised LPP with kernels is presented. Many experiments are implemented on four breast tissue databases to testify and evaluate the feasibility and affectivity of the proposed scheme.

Hypoxia inhibits the spontaneous calcification of bone marrow-derived mesenchymal stem cells.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are the popular seed cells for regenerative medicine, and there has been a rapid increase in the number of BM-MSC-based clinical trials. However, the safety of these cells should also be closely studied. In this study, spontaneous calcification of BM-MSCs from rats was evaluated in normoxia (20% O(2)) without osteogenic medium after continuous culture for 21 days; obvious mineralized nodules were observed, which were positive for Alizarin Red, collagen-I (Col-I), osteocalcin (OC) and alkaline phosphatase (ALP), and mainly consisted of C, O and Ca elements. Interestingly, hypoxia (2% O(2)) significantly inhibited this spontaneous calcification. In addition, the ALP and calcium content of rBM-MSCs were sharply reduced. Based on RT-PCR results, the expression of osteogenic genes (Cbfa1/Runx2, Col-I, ALP, and OC) was reduced compared to that in normoxia. These results demonstrate a natural and unique characterization of rat BM-MSCs in normoxia after continuous culture and highlight the inhibiting effects of hypoxia. Finally, this study contributes to the information regarding the application of BM-MSCs in the regeneration of various tissues.

Sonic hedgehog enhances the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells.

MSCs (mesenchymal stem cells) may be promising seed cells for tissue regeneration because of their self-renewal and multi-differentiation potential. Shh (sonic hedgehog) is involved in the skeletal formation during embryo development and skeletal regeneration. However, how Shh regulates the biological characteristics of BM-MSCs (bone marrow-derived MSCs) is poorly understood. We have investigated the effect of rShh-N (recombinant N-terminal Shh) on the proliferation and osteogenic differentiation of rBM-MSCs (rat BM-MSCs) in vitro. rBM-MSCs were treated with rShh-N at concentrations up to 200 ng/ml. Proliferation and colony-forming ability of rBM-MSCs were increased in a dose-dependent manner. rShh-N increased the ratio of cells in S and G2/M phase, as well as the number of Ki-67+ cells. In addition, ALP (alkaline phosphatase) activity and matrix mineralization were enhanced by 200 ng/ml rShh-N. Real-time PCR showed that rShh-N (200 ng/ml) up-regulated the expression of genes encoding Cbfa-1 (core-binding factor α1), osteocalcin, ALP and collagen type I in rBM-MSCs. This information reveals some potential of rShh-N in the therapeutics of bone-related diseases.