疏肝活血法对下肢缺血模型大鼠血管内皮祖细胞的影响

[目的]观察疏肝活血法时下肢缺血模型大鼠外周血管内皮祖细胞(EPC)的影响.[方法]将50只SD大鼠随机分为3组:中药组20只,模型组20只,假手术组10只.中药组和模型组均采用右下肢股动脉结扎及分支剔除术复制大鼠下肢缺血模型,假手术组仅暴露股动脉但不结扎股动脉及其分支.中药组术后按0.5 g·kg-1·d-1剂量灌服柴胡疏肝散合大黄座虫丸煎剂,连续7 d.检测各组术前1 d、术后第1、3、7天4个时间点大鼠外周血酶学指标肌酸激酶(CK)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)、α-羟丁酸脱氢酶(HBDH)水平变化及双荧光阳性细胞[CD34+、血管内皮生长因子受体(VEGFR2+)]比例.[结果]术后模型组外周血酶学指标AST、CK、LDH、HBDH水平较假手术组均显著上升,术后第3、7天中药组各项酶学指标水平较模型组及术后第1天均显著下降(P<0.05).术后中药组和模型组反映EPC变化的CD34+、VEGFR2+双荧光阳性细胞比例较假手术组均显著升高(P<0.05),且中药组升高较模型组更为显著(P<0.05或P<0.01).[结论]疏肝活血法可有效地改善下肢缺血状态,其作用可能与其能增加外周血EPC数量有关.     

Modification of COL1A1 in Autologous Adipose Tissue-Derived Progenitor Cells Rescues the Bone Phenotype in a Mouse Model of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a congenital genetic disorder mainly manifested as bone fragility and recurrent fracture. Mutation of COL1A1/COL1A2 genes encoding the type I collagen are most responsible for the clinical patients. Allogenic mesenchymal stem cells (MSCs) provide the potential to treat OI through differentiation into osteoblasts. Autologous defective MSCs have not been utilized in OI treatment mainly because of their impaired osteogenesis, but the latent mechanism has not been well understood. Here, the relative signaling abnormality of adipose-derived mesenchymal stem cells (ADSCs) isolated from OI type I mice (Col1a1^+/−365 mice) was explored. Autologous ADSCs transfected by retrovirus carrying human COL1A1 gene was first utilized in OI therapy. The results showed that decreased activity of Yes-associated protein (YAP) due to hyperactive upstream Hippo kinases greatly contributed to the weakened bone-forming capacity of defective ADSCs. Recovered collagen synthesis of autologous ADSCs by COL1A1 gene modification normalized Hippo/YAP signaling and effectively rescued YAP-mediated osteogenesis. And the COL1A1 gene engineered autologous ADSCs efficaciously improved the microstructure, enhanced the mechanical properties and promoted bone formation of Col1a1^+/−365 mice after femoral bone marrow cavity delivery and might serve as an alternative source of stem cells in OI treatment. © 2021 American Society for Bone and Mineral Research (ASBMR).     

Cytotoxicity of ventricular cerebrospinal fluid from Parkinson patients: Correlation with clinical profiles and neurochemistry

Abstract

Other investigators have reported that the cerebrospinal fluid (CSF) from patients with Parkinson's disease (PD) might contain endogenous dystrophic factors. Using CSF samples drawn from individual PD patients during surgery, we investigated the toxic effect of ventricular CSF (vCSF) on the growth of PC12 cells and the correlation between the clinical profiles of the patients and CSF neurochemistry. Ventricular CSF samples from 28 patients with PD or essential tremor (ET) were collected during ventriculography for stereotactic pallidotomy or thalamotomy. PC12 cells were incubated with 20% vCSF from both clinical groups for up to 72 h. Microdialysis was used to analyze four neurochemical parameters (glucose, lactate, pyruvate, and glutamate) in each vCSF sample. We observed that vCSF drawn from PD patients exerted nonspecific growth inhibition on PC12 cells in a time-dependent manner. The growth inhibitory action of PD–vCSF decreased significantly after heat treatment. Microdialysis demonstrated no statistical differences between PD and ET samples among the four parameters studied. In addition, PC12 cell survival after 72 h incubation with PD-vCSF correlated with no neurochemical parameter or individual clinical profile (age, onset age, duration of disease, Hoehn & Yahr stage, disease progression rate), except for a slight correlation between vCSF and disease progression rate in heat treated samples from female patients. One or more endogenous cytotoxic factors in PD-vCSF inhibit PC12 cell growth. This factor or factors are partially sensitive to heat which suggests proteins or peptides as possible agents. The cytotoxic effect of PD-vCSF did not directly correlate with any clinical profiles studied or energy metabolism of PD brain.     

Growth inhibition of MCF-7 tumor cell line by phenylacetate linked to functionalized dextran

We investigated the antiproliferative effect of phenylacetate covalently linked to dextran derivatives (DMCBPA conjugates) on human breast cancer MCF-7 cells. We show that free sodium phenylacetate (NaPA) inhibits the cell growth (IC₅₀ = 14 mM), while an important inhibitory effect is observed for DMCBPA conjugates. The IC₅₀ dose of these conjugates is as low as 1.0 mg/ml, corresponding to 1.3 mM of phenylacetate. The precursors, dextran substituted with methylcarboxylate and benzylamide groups, did not affect the growth of MCF-7 tumor cells. We have observed that MCF-7 cell growth inhibition depends on amount of phenylacetate linked to the conjugate. The data indicated that an optimum antiproliferative effect is more significant when the amount of phenylacetate groups present on the dextran backbone is high. Analysis of doubling time by growth kinetics study shows that conjugates have more time-sustained effect than free NaPA. It is noteworthy that the inhibitory effect is observed at non-toxic concentration. Theses conjugates could be considered as acceptable derivatives to prevent tumor progression.     

Incorporation of sulfonylurea into sugar-carrying polymers and their effects on insulin secretion from MIN6 cells in a solution state

A hypoglycemic sulfonylurea (SU) was incorporated into non-reducing glucose-bearing polystyrene (PS) derivative for enhanced interaction with, and insulin secretion from an insulinoma cell line (MIN6). SU derivative was copolymerized with styrene having sugar moiety such as maltose or lactose. About an 80% increase in insulin secretion for poly(N-p-vinylbenzyl-D-maltonamide-co-SU) (p(VMA-co-SU)) was observed when the copolymer was added to the culture medium (SU : 25 mol%), whereas about 50% increase for poly(N-p-vinylbenzyl-D-lactonamide-co-SU) (p(VLA-co-SU)) was observed when compared with unstimulated cells. From the measurement of flow cytometry, the fluorescence intensity of MIN6 cells incubated in culture media containing FITC-labeled SU-incorporated copolymer increased remarkly owing to specific interaction between receptors in the cell membrane and SU ligands in the copolymer. When sugar and/or SU-incorporated copolymer were co-entrapped with the cells in agarose or collagen gel as an extracellular matrix for three-dimensional culture, p(VMA-co-SU) enhanced more insulin secretion from MIN6 cells than other polymers and it was found that collagen gel was more effective in insulin secretion than agarose gel.     

UV surface modification of a new nanocomposite polymer to improve cytocompatibility

A novel modified nanocomposite was studied for the adhesion and proliferation of the human umbilical vein endothelial cell (HUVEC) line EA.hy926. The nanocomposite under investigation was poly(carbonate-urea)urethane with silsesquioxane nano-cages, here in the form of a mixture of two polyhedral oligomeric silsesquioxanes. The nanocomposite surfaces were exposed to ultraviolet (UV) light of a Xe^* ₂-excimer lamp at a wavelength of 172 nm in an ammonia atmosphere. The effects of the irradiation were characterized by atomic force and scanning electron microscopy (AFM, SEM), X-ray photo-electron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR) using an attenuated total reflection (ATR) device and measurements of advancing water contact angle (CA). The irradiation resulted in the introduction of new hydrophilic N- and O-containing groups into the surface, which was initially amphiphilic, while surface morphology remained mainly unchanged. Slight chemical changes were also observed for the silsesquioxane nano-cages at the surface. Onto the untreated and irradiated samples HUVECs were seeded and grown for various durations in culture. Standard tissue-culture polystyrene (PS) was employed as a positive control to check the efficiency of the cell-culture methods. Viability and proliferation of the cells were then assessed using a non-radioactive assay. Compared to the untreated nanocomposite polymer, irradiation times of at least 5 min resulted in a significantly increased cell proliferation between 3 and 8 days after seeding with the HUVEC line EA.hy926.     

Measurements of Movement and Diffusion Coefficients of Single Cells on Polymeric Surface from Image Analysis

Time-lapse digital images were taken every 30 s of PC12 cells cultured on polystyrene dishes, collagen-coated dishes and poly(L-lysine)-coated dishes in high-serum medium, low-serum medium and neurite outgrowth factor (NGF)-containing medium to investigate their diffusion coefficients (i.e., self-diffusion coefficients), D and specific movement (i.e., specific frequent movement) using image analysis and Fast Fourier Transform (FFT) analysis. D for these cells was found to fluctuate as a function of time, D varying between 0 and 0.08 μm²/s. The trend observed upon examination of average D values was: D in high-serum medium ≥ D in low-serum medium ≥ D in NGF-containing medium. Image analysis and FFT analysis of single cells cultured on polymeric dishes in these three media did not have any specific frequency of cell movement between 0 and 0.0167 Hz. The high diffusion coefficient and high amplitude of power spectra of PC12 cells in high-serum medium might be attributed to the high energy necessary for their continual suppression of the mitogen-activated protein kinase (MAPK) cascade and for them to maintain their undifferentiated state.     

Characterization of the Differentiation and Leptin Secretion Profile of Adult Stem Cells on Patterned Polylactide Films

Several issues need to be better understood before breast tissue engineering becomes a clinically viable option. One of the most important aspects is the interaction between cells and the microtopography of the implant surface. The aim of this study was to evaluate the efficacy of D1 cells, multipotent mouse bone marrow stromal precursors, in differentiating to adipocytes and to characterize their metabolic activity (lactic acid released and glucose consumed), leptin secretion and lipid production when cultured on patterned poly(L-lactide) (PLLA) films. It was determined that, by appropriate stimulation, the D1 cells displayed morphological characteristics of adipocytes and produced lipid. The results showed that a patterned surface did affect the rate of lipid production. Polynomial models were proposed to predict the amount of leptin secreted by the cells over a period of time.     

Clinical characteristics influence in vitro action of 1,25-dihydroxyvitamin D(3) in human marrow stromal cells

Vitamin D is important for bone health, with low vitamin D levels being associated with skeletal fragility and fractures. Among its other biological activities, 1,25-dihydroxyvitamin D (1,25(OH)₂D), stimulates the in vitro differentiation of human marrow stromal cells (hMSCs) to osteoblasts, which can be monitored by increases in alkaline phosphatase enzyme activity or osteocalcin gene expression. In this study, we tested the hypotheses that age and clinical attributes of subjects influence in vitro responsiveness of hMSCs to 1,25(OH)₂D₃. In a cohort of subjects whose hMSCs were isolated from bone marrow discarded during hip replacement surgery for osteoarthritis, there were significant inverse correlations with age for bone mineral density, renal function, body mass index, fat mass index, and lean mass index (n = 36–53). There were significant correlations with serum 25(OH)D for serum parathyroid hormone (PTH), body mass index, fat mass index, and lean mass index (n = 47–50). In vivo–in vitro correlation analyses indicated that there were significantly greater in vitro effects of 1,25(OH)₂D₃ to stimulate osteoblast differentiation in hMSCs obtained from subjects who were younger than 65 years of age, or who had serum 25(OH)D ≤ 20 ng/mL, elevated serum PTH, or better renal function, assessed by estimated glomerular filtration rate. The greater in vitro stimulation of osteoblast differentiation by 1,25(OH)₂D₃ in hMSCs from vitamin D-deficient subjects suggests that vitamin D replenishment may lead to more vigorous bone formation in subjects at risk. © 2012 American Society for Bone and Mineral Research.     

袁氏生脉成骨胶囊对激素诱导骨髓基质细胞成脂分化的拮抗作用

【目的】观察中药袁氏生脉成骨胶囊(主要由丹参、川芎、鸡血藤、黄芪组成)对激素诱导骨髓基质细胞成脂分化的拮抗作用,探讨袁氏生脉成骨胶囊防治激素性股骨头坏死的病理机制。【方法】采用骨髓细胞体外培养技术和血清药理学方法,分离培养大鼠骨髓基质细胞;地塞米松诱导骨髓基质细胞的成脂分化,以含中药血清作为拮抗剂。检测培养细胞的甘油三酯含量和碱性磷酸酶活性。【结果】分离细胞培养4d后可以观察到大量成骨细胞、成纤维细胞、破骨细胞;模型组加入地塞米松造模;成骨胶囊药物组地塞米松用法同模型组,同时加入含药血清。6d后,光镜下观察成骨胶囊药物组见少量脂肪细胞,模型组脂肪细胞明显增多。成骨胶囊药物组碱性磷酸酶活性高于模型组(P<0.05);甘油三酯含量低于模型组(P<0.01)。【结论】中药袁氏生脉成骨胶囊能够有效拮抗激素诱导骨髓基质细胞成脂分化。提示活血化瘀类中药防治股骨头坏死的机理不仅是改善了股骨头的微循环,而且抑制了骨髓基质细胞成脂分化,增加了成骨细胞的表达。