两种诱导液对牙周膜干细胞膜片生物学活性影响

目的探讨不同的诱导液对牙周膜干细胞(PDLSCs)膜片生物学活性的影响。方法分别使用骨髓间充质细胞条件(BMMSCs-CM)诱导液与根端牙胚条件(APTG-CM)诱导液培养人PDLSCs,并制备成PDLSCs膜片。BMSCs-CM诱导液诱导的细胞设为BMSCs-CM组,APTG-CM诱导液诱导的细胞设为APTG-CM组。分别诱导PDLSCs膜片4、7、10 d。通过倒置显微镜、HE染色、免疫组化、扫描电镜检测并观察两种诱导液诱导后的PDLSCs细胞膜片形态学的变化及生物学特性的差异。结果接种10 d后,BMSCs-CM组和APTG-CM组的克隆形成率分别为37%和24%,BMSCs-CM的克隆形成能力明显强于APTG-CM组,差异有统计学意义(P<0.05)。与APTG-CM诱导液比较,经过BMMSCs诱导液诱导后的PDLSCs膜片可产生更丰富的细胞外基质。扫描电镜可见BMMSCs诱导液诱导后的细胞膜片表面有矿化沉积和胶原组织形成;APTG-CM诱导液诱导后的细胞膜片表面有大量胶原纤维状组织形成。结论 BMMSCs诱导液更适合诱导PDLSCs膜片向类牙周组织分化。     

A proteomic approach to investigate AuNPs effects in Balb/3T3 cells

Although gold nanoparticles (AuNPs) are currently used in several industrial products and biomedical applications, information about their biological effects is very limited. Thus, it is becoming crucial to assess their safety and adequately investigate the complexity of cell–nanoparticles interactions. In this work, the Balb/3T3 mouse fibroblast cell line was selected as an in vitro model to study the effects of AuNPs. Alteration of cellular processes and biochemical pathways caused by AuNPs exposure was investigated by analysing the differentially expressed proteome. Of interest was the difference observed in the protein pattern expression of cells exposed to AuNPs. It was found that 88 and 83 proteins were de-regulated after exposure to 5 and 15 nm AuNPs, respectively. Analysis of the proteome revealed that AuNPs triggers several pathways related to cellular growth and proliferation, cell morphology, cell cycle regulation, cellular function and maintenance, oxidative stress, and inflammatory response. Moreover, SPR analysis showed an increase of ECM proteins biosynthesis in cells exposed to AuNPs. We observed by TEM analysis that NPs are internalized and confined mainly in autophagosomes. Endoplasmic reticulum stressed and modification at mitochondrial level occurred. This study aims to improve existing knowledge necessary for a correct assessment of the balance between AuNPs potential adverse and beneficial effects and might have important implications for biomedical applications (e.g. nanomedicine).     

Extracellular calcium and CaSR drive osteoinduction in mesenchymal stromal cells

Bone is the main store of calcium and progenitor cells in the body. During the resorption process, the local calcium concentration reaches 8–40 mM, and the surrounding cells are exposed to these fluctuations in calcium. This stimulus is a signal that is detected through the calcium sensing receptor (CaSR), which modulates chemotactic and proliferative G protein-dependent signaling pathways. The objective of the present work is to evaluate the roles of extracellular calcium ([Ca²⁺]_o) and the CaSR in osteoinduction. Rat bone marrow mesenchymal stromal cells (rBMSCs) were stimulated with 10 mM of Ca²⁺. Several experiments were conducted to demonstrate the effect of [Ca²⁺]_o on chemotaxis, proliferation and differentiation on the osteoblastic lineage. It was found that [Ca²⁺]_o induces rBMSCs to migrate and proliferate in a concentration-dependent manner. Real-time polymerase chain reaction and immunofluorescence also revealed that 10 mM Ca²⁺ stimulates overexpression of osteogenic markers in rBMSCs, including alkaline phosphatase (ALP), bone sialoprotein, collagen Ia1 and osteocalcin. Functional assays determining ALP activity and mineralization tests both corroborate the increased expression of these markers in rBMSCs stimulated with Ca²⁺. Moreover, CaSR blockage inhibited the cellular response to stimulation with high concentrations of [Ca²⁺]_o, revealing that the CaSR is a key modulator of these cellular responses.     

乙酰肝素酶与相关疾病的研究进展

乙酰肝素酶（HPA）是人体内唯一能降解硫酸肝素蛋白多糖（HSPG）的一种β-D-葡萄糖醛酸内切酶。HSPG是细胞外基质（ECM）的重要组成部分,广泛分布于细胞表面,在正常组织的发育与病理学改变的发展中具有重要作用。HPA能识别 HSPG的硫酸肝素链（HS）并将其降解,进而影响 ECM与上皮细胞及内皮细胞基底膜结构,释放与 HSPG结合的各种细胞因子。除通过降解 HS产生间接生理作用外, HPA还以聚集、脱落、分裂素绑定的方式影响多配体聚糖的生物效应。另外,HPA 可以增强信号级联效应,促进蛋白激酶的磷酸化和基因转录。因此,HPA的激活会引起一些病理生理学改变,包括炎性反应、血管形成、肿瘤转移、胚胎植入等。笔者拟就 HPA与相关疾病的研究进展,进行综述如下。     

Ion Transport and Energy Metabolism in Brain

Abstract

The kinetics of extracellular K⁺ activity was compared to the availability of energy in the cortex of rats and gerbils exposed to anoxia, hypoxia, spreading depression, and ischemia.

A combined K⁺/DC surface electrode was used alone or together with a fiber optic light guide in various experiments. All experiments were done on slightly anesthetized animals that were practically awake. The results can be summarized in the following conclusions: (1) Under conditions such as hypoxia or ischemia, K⁺₀ showed a two-phase efflux kinetics, and a transition or critical point was reached where the response proceeds at a higher rate. This critical point was in the range of 10-16 mEq/1 potassium. (2) Availability of oxygen is necessary but not sufficient for a full rate of recovery from a long-term oxygen-deprivation insult. (3) There is an energy debt or energy-transduction bottleneck fonned during a prolonged O₂ insufficiency. This debt is reversed slowly during the recovery phase even when full restitution of O₂ supply and blood flow has occurred.     

Urine proteomes of healthy aging humans reveal extracellular matrix (ECM) alterations and immune system dysfunction

Aging is a complex physiological process that poses considerable conundrums to rapidly aging societies. For example, the risk of dying from cardiovascular diseases and/or cancer steadily declines for people after their 60s, and other causes of death predominate for seniors older than 80 years of age. Thus, physiological aging presents numerous unanswered questions, particularly with regard to changing metabolic patterns. Urine proteomics analysis is becoming a non-invasive and reproducible diagnostic method. We investigated the urine proteomes in healthy elderly people to determine which metabolic processes were weakened or strengthened in aging humans. Urine samples from 37 healthy volunteers aged 19–90 years (19 men, 18 women) were analyzed for protein expression by liquid chromatography–tandem mass spectrometry. This generated a list of 19 proteins that were differentially expressed in different age groups (young, intermediate, and old age). In particular, the oldest group showed protein changes reflective of altered extracellular matrix turnover and declining immune function, in which changes corresponded to reported changes in cardiovascular tissue remodeling and immune disorders in the elderly. Thus, urinary proteome changes in the elderly appear to reflect the physiological processes of aging and are particularly clearly represented in the circulatory and immune systems. Detailed identification of “protein trails” creates a more global picture of metabolic changes that occur in the elderly.     

The adipogenic potential of various extracellular matrices under the influence of an angiogenic growth factor combination in a mouse tissue engineering chamber

The extracellular matrix (ECM) Matrigel™ has frequently and successfully been used to generate new adipose tissue experimentally, but is unsuitable for human application. This study sought to compare the adipogenic potential of a number of alternative, biologically derived or synthetic ECMs with potential for human application, with and without growth factors and a small fat autograft. Eight groups, with six severe combined immunodeficient (SCID) mice per group, were created with bilateral chambers (silicone tubes) implanted around the epigastric vascular pedicle, with one chamber/animal containing a 5 mg fat autograft. Two animal groups were created for each of four ECMs (Matrigel™, Myogel, Cymetra® and PuraMatrix™) which filled the bilateral chambers. One group/ECM had no growth factors added to chambers whilst the other group had growth factors (GFs) (vascular endothelial growth factor-A (VEGF-A) plus fibroblast growth factor-2 (FGF-2) plus platelet-derived growth factor-BB (PDGF-BB)) added to both chambers. At 6 weeks, chamber tissue was morphometrically assessed for percent and absolute adipose tissue volume. Overall, the triple GF regime significantly increased percent¹ and absolute^# adipose tissue volume (p < 0.0005^1#) compared to chambers without triple GF treatment. The fat autograft also significantly increased percent (p < 0.0005) and absolute (p < 0.011) adipose tissue volume. Cymetra® (human collagen) constructs yielded the largest total tissue and absolute adipose tissue volume. We found that the pro-angiogenic FGF-2, VEGF-A and PDGF-BB combination in ECMs of synthetic and biological origin produced an overall significantly increased adipose tissue volume at 6 weeks and may have clinical application, particularly with Cymetra.     

Periostin: A Novel Prognostic and Therapeutic Target For Genitourinary Cancer?

Many of the cellular abnormalities present in solid tumors are structural in nature and involve the proteins of the extracellular matrix (ECM). Periostin is a protein produced and secreted by the fibroblasts as a component of the ECM where it is involved in regulating intercellular adhesion. The expression of periostin has an important physiological role during embryogenesis and growth, namely at the level of bone, dental, and cardiac tissues. Many studies indicate that periostin plays an important role for tumor progression in various types of cancer, such as colon, lung, head and neck, breast, ovarian, and prostate. To the best of our knowledge, a limited number of studies have investigated periostin expression in urogenital cancer, such as prostate, bladder, penile, and renal cancer, and no studies were performed in testis cancer. In this review article, we summarize the most recent knowledge of periostin, its genetic and protein structure, and the role of the different isoforms identified and sequenced so far. In particular, we focus our attention on the role of this protein in genitourinary tumors, trying to emphasize the role not only as a possible prognostic marker, but also as a possible target for the development of future anticancer therapies.