视黄醇结合蛋白4 对血管平滑肌细胞迁移和增殖的影响及机制

目的:研究视黄醇结合蛋白4(Retinol-binding protein 4,RBP4)对血管平滑肌细胞(SMCs)迁移和增殖的影响及分子机制。方法:体外培养大鼠主动脉SMCs,采用划痕实验及Boyden's迁移小室实验观察RBP4对SMCs迁移的影响,采用免疫印迹实验技术检测Akt的磷酸化水平,采用Boyden's小室实验观察PI3K抑制剂LY294002预处理细胞对RBP4促SMCs迁移的影响,应用MTT比色实验结合流式细胞仪技术,检测RBP4对SMCs细胞增殖及细胞周期的影响。结果:RBP4呈剂量依赖性诱导大鼠血管SMCs迁移(P0.05);RBP4处理细胞显著增加了Akt磷酸化;PI3K抑制剂LY294002预处理细胞则显著抑制了RBP4的促迁移作用(P0.05);RBP4处理有增加SMCs数量的趋势,且可轻微阻滞细胞进入S期,但未达到统计学显著性(P0.05)。结论:RBP4通过PI3K-Akt通路诱导大鼠血管SMCs迁移,对细胞增殖及细胞周期则无显著影响。     

Comparative genomic and phylogenetic analysis of short-chain dehydrogenases/reductases with dual retinol/sterol substrate specificity

Human short-chain dehydrogenases/reductases with dual retinol/sterol substrate specificity (RODH-like enzymes) are thought to contribute to the oxidation of retinol for retinoic acid biosynthesis and to the metabolism of androgenic and neuroactive 3alpha-hydroxysteroids. Here, we investigated the phylogeny and orthology of these proteins to understand better their origins and physiological roles. Phylogenetic and genomic analysis showed that two proteins (11-cis-RDH and RDHL) are highly conserved, and their orthologs can be identified in the lower taxa, such as amphibians and fish. Two other proteins (RODH-4 and 3alpha-HSD) are significantly less conserved. Orthologs for 3alpha-HSD are present in all mammals analyzed, whereas orthologs for RODH-4 can be identified in some mammalian species but not in others due to species-specific gene duplications. Understanding the evolution and divergence of RODH-like enzymes in various vertebrate species should facilitate further investigation of their in vivo functions using animal models.     

急性脑梗死患者血清RBP、NLR、PTX3水平与颈动脉粥样硬化斑块稳定性的关系研究

目的:探讨急性脑梗死(ACI)患者血清视黄醇结合蛋白(RBP)、中性粒细胞与淋巴细胞比值(NLR)、内正五聚蛋白3(PTX3)水平与颈动脉粥样硬化斑块稳定性的关系。方法:收集我院2017年1月～2019年1月收治的300例ACI患者,根据颈动脉粥样硬化斑块超声结果分为稳定斑块组(n=173)和不稳定斑块组(n=127),另选同期在我院体检中心进行健康体检的志愿者100例为对照组。对ACI患者和对照组进行RBP、NLR、PTX3、血脂指标的检测,并进行组间统计学对比。采用Pearson检验对ACI患者的RBP、NLR、PTX3与血脂指标的相关性进行分析。结果:三组受试者性别、年龄、体质指数(BMI)、吸烟史、饮酒史等基础资料对比无显著性差异(P0.05)。稳定斑块组、不稳定斑块组患者的RBP、NLR、PTX3水平均高于对照组,且不稳定斑块组上述指标水平高于稳定斑块组(P0.05)。稳定斑块组、不稳定斑块组患者的总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL-C)、纤维蛋白原(FIB)水平均高于对照组,且不稳定斑块组上述指标水平高于稳定斑块组(P0.05)。经Pearson检验分析,ACI患者的RBP、NLR、PTX3水平与TC、TG、LDL-C、FIB均呈正相关性(P0.05)。结论:在ACI患者中RBP、NLR、PTX3水平较高,并与患者的颈动脉粥样硬化斑块的稳定性有紧密的关联性。初步推测RBP、NLR、PTX3可能参与颈动脉粥样硬化斑块的形成,进而影响ACI疾病的发生发展过程。     

随机尿、晨尿视黄醇结合蛋白对早期肾功能损伤的诊断价值

目的:探究随机尿、晨尿视黄醇结合蛋白对早期肾功能损伤的诊断价值.方法:选取我院2011年8月-2012年9月收治的48例Ⅱ型糖尿病患者,按照随机数字表进行平均分组,随机尿组24例,选取任意时段尿液标本,晨尿组24例,选取清晨时段尿液标本.对两组患者尿液标本进行尿视黄醇结合蛋白(Urinary Retinol-binding Protein,U-RBP)、尿微量白蛋白(Urinary Microalbum, U-mAlb)及尿N-乙酰-β-D氨基葡萄糖苷酶(Urinary N-acetyl beta-D-Glucosaminidase,NAG)水平测定,进行相关性分析并观察两组诊断阳性率.结果:随机尿组U-RBP、U-mAlb及NAG分别为(1.7± 0.9) mg/L、(76.2± 41.5) mg/L及(41.2± 30.0) U/L;晨尿组U-RBP、U-mAlb及NAG分别为(3.6±1.2)mgL、(118.5±71.)mg/L及(116.5±71.9) U/L.两组患者尿液检测指标均高于正常值,且晨尿组指标较随机尿组更高,两组数据对比存在统计学差异;随机尿组U-RBP、U-mAlb及NAG阳性例数分别为12例、6例及4例,晨尿组U-RBP、U-mAlb及NAG阳性例数分别为17例、13例及11例,晨尿组U-RBP、U-mAlb及NAG阳性率均高于随机尿组,两组数据对比存在统计学差异;随机尿组U-RBP与肾损伤相关性r=0.532,P ＞0.05,无明显相关性;晨尿组U-RBP与肾损伤相关性r=0.867,P＜0.01,呈高度正相关.结论:随机尿及晨尿均可指示患者肾损伤出现,但随机尿蛋白指标无法有效指示肾损伤程度,对早期肾功能损害确诊准确率有限,而晨尿尿蛋白正常排泄率更高,且能够有效指示肾损伤程度,适用于糖尿病早期肾功能损伤的诊断及监测.     

尿神经突起导向因子1、肾损伤分子-1、视黄醇结合蛋白水平与妊娠期高血压疾病早期肾损伤的关系研究

摘要 目的：研究尿神经突起导向因子1（Netrin-1）、肾损伤分子-1（Kim-1）、视黄醇结合蛋白（RBP）水平与妊娠期高血压疾病（HDCP）早期肾损伤的关系。方法：将我院从2017年2月～2020年2月收治的HDCP患者80例纳入研究,按照HDCP严重程度分作妊娠期高血压组22例、轻度子痫前期组32例、重度子痫前期组26例,另随机选取同期于我院接受规律孕产检以及分娩正常妊娠孕妇40例作为正常妊娠组,检测并比较各组尿Netrin-1、Kim-1、RBP水平。此外,将HDCP患者按照是否出现早期肾损伤分作肾功能损伤组42例和肾功能正常组38例,比较两组尿Netrin-1、Kim-1、RBP以及肾功能指标水平,并进行相关性分析,通过Logistic回归分析HDCP早期肾损伤的影响因素。结果：正常妊娠组、妊娠期高血压组、轻度子痫前期组、重度子痫前期组尿Netrin-1水平呈逐渐降低趋势,而尿Kim-1、RBP水平均呈逐渐升高趋势,多组数据间两两对比差异均有统计学意义（均P＜0.05）。肾功能损伤组尿Netrin-1水平低于肾功能正常组,而尿Kim-1、RBP以及血尿素氮、血肌酐、24 h尿白蛋白排出量（UAE）水平均明显高于肾功能正常组（均P＜0.05）。经Pearson相关性分析可得：HDCP早期肾损伤患者尿Netrin-1水平和血尿素氮、血肌酐、UAE均呈负相关关系,而Kim-1、RBP水平和血尿素氮、血肌酐、UAE均呈正相关关系（均P＜0.05）。经Logistic回归分析发现：尿Netrin-1是HDCP早期肾损伤的保护因素,而尿Kim-1、RBP是HDCP早期肾损伤的危险因素（均P＜0.05）。结论：随着尿Netrin-1水平的降低以及Kim-1、RBP水平的升高,HDCP早期肾损伤风险越高,检测尿Netrin-1、Kim-1、RBP水平可能有助于评估HDCP的病情严重程度和肾功能损伤。     

Structure and function of retinol dehydrogenases of the short chain dehydrogenase/reductase family

All-trans-retinol is the common precursor of the active retinoids 11-cis-retinal, all-trans-retinoic acid (atRA) and 9-cis-retinoic acid (9cRA). Genetic and biochemical data supports an important role of the microsomal members of the short chain dehydrogenases/reductases (SDRs) in the first oxidative conversion of retinol into retinal. Several retinol dehydrogenases of this family have been reported in recent years. However, the structural and functional data on these enzymes is limited. The prototypic enzyme RDH5 and the related enzyme CRAD1 have been shown to face the lumen of the endoplasmic reticulum (ER), suggesting a compartmentalized synthesis of retinal. This is a matter of debate as a related enzyme has been proposed to have the opposite membrane topology. Recent data indicates that RDH5, and presumably other members of the SDRs, occur as functional homodimers, and need to interact with other proteins for proper intracellular localization and catalytic activity. Further analyses on the compartmentalization, membrane topology, and functional properties of microsomal retinol dehydrogenases, will give important clues about how retinoids are processed.     

Retinol and retinoic acid bind human serum albumin: stability and structural features

Vitamin A components, retinol and retinoic acid, are fat-soluble micronutrients and critical for many biological processes, including vision, reproduction, growth, and regulation of cell proliferation and differentiation. The cellular uptake of Vitamin A is through specific interaction of a plasma membrane receptor with serum retinol-binding protein. Human serum albumin (HSA), as a transport protein, is the major target of several micronutrients in vivo. The aim of present study was to examine the interaction of retinol and retinoic acid with human serum albumin in aqueous solution at physiological conditions using constant protein concentration and various retinoid contents. FTIR, UV–vis, CD and fluorescence spectroscopic methods were used to determine retinoid binding mode, the binding constant and the effects of complexation on protein secondary structure.

Structural analysis showed that retinol and retinoic acid bind non-specifically (H-bonding) via protein polar groups with binding constants of K_ret = 1.32 (±0.30) × 10⁵ M⁻¹ and K_retac = 3.33 (±0.35) × 10⁵ M⁻¹. The protein secondary structure showed no alterations at low retinoid concentrations (0.125 mM), whereas at high retinoid content (1 mM), an increase of -helix from 55% (free HSA) to 60% and a decrease of β-sheet from 22% (free HSA) to 18% occurred in the retinoid–HSA complexes. The results point to a partial stabilization of protein secondary structure at high retinoid content.     

肾小球肾炎血清BUN、RBP的诊断价值分析

摘要 目的：探讨肾小球肾炎血清中尿素氮（BUN）、视黄醇结合蛋白（RBP）的表达及意义。方法：选择2018年1月至2021年1月大华医院和我院接诊的75例肾小球肾炎患者为本研究对象,设为试验组,另选择同期在我院体检的55例作为对照组,分析血清BUN、RBP水平变化情况,及其诊断价值。结果：试验组患者血清BUN、RBP水平（15.52±1.51 mmol/L、97.87±21.28 mg/L）显著高于对照组（5.07±0.97 mmol/L、42.17±10.25 mg/L）,差异显著（P＜0.05）;重度肾小球肾炎患者血清BUN、RBP水平（19.01±1.20 mmol/L、118.83±21.24 mg/L）均显著高于轻度（11.56±1.07 mmol/L、71.24±19.87 mg/L）、中度肾小球肾炎患者（14.89±1.12 mmol/L、95.75±22.13 mg/L）,差异显著（P＜0.05）;中度肾小球肾炎患者血清 BUN、RBP水平（14.89±1.12 mmol/L、95.75±22.13 mg/L）均显著高于轻度肾小球肾炎患者（11.56±1.07 mmol/L、71.24±19.87 mg/L）,差异显著（P＜0.05）;BUN诊断肾小球肾炎的AUC为0.866,95%CI为0.807~0.926,截断值为8.45 mmol/L;RBP诊断肾小球肾炎的AUC为0.957,95%CI为0.927~0.987,截断值为57.29 mg/L;联合检测诊断肾小球肾炎的AUC为0.991,95%CI为0.980~1.000,单独检测分别和联合检测曲线下面积比较均具有显著差异（Z=4.11、2.150,P＜0.05）;联合检测的特异度、准确度分别为93.41%、94.15%。结论：在肾小球肾炎患者中血清BUN、RBP的表达和病情严重程度之间存在着密切关系,可作为诊断肾小球肾炎的重要指标。     

Electrospun bioactive mats enriched with Ca-polyphosphate/retinol nanospheres as potential wound dressing

BackgroundWhile electrospun materials have been frequently used in tissue engineering no wound dressings exist that significantly improved wound healing effectively.MethodsWe succeeded to fabricate three-dimensional (3D) electrospun poly(D,l-lactide) (PLA) fiber mats into which nanospheres, formed from amorphous calcium polyphosphate (polyP) nanoparticles (NP) and encapsulated retinol (“retinol/aCa-polyP-NS” nanospheres [NS]), had been incorporated.ResultsExperiments with MC3T3-E1 cells revealed that co-incubation of the cells with Ca-polyP together with retinol (or incubation with retinol/aCa-polyP-NS) resulted in a significant synergistic effect on cell growth compared with particle-free polyP complexed with Ca²⁺ or amorphous Ca-polyP NPs and retinol alone. Incubation of the cells in the presence of the retinol/aCa-polyP NSs also caused a significant increase of the expression levels of the genes encoding for the fatty acid binding protein 4 (FABP4), as well as of the genes encoding for leptin and the leptin receptor. In contrast, the single components, soluble Na-polyP, complexed to Ca²⁺, or retinol-free aCa-polyP NPs, and retinol, had no significant effect on the expression of these genes.ConclusionsThese results indicate that the PLA fibers, supplemented with aCa-polyP-NP or retinol/aCa-polyP-NS, elicit morphogenetic activity, suggesting that these fiber mats, along with the antibacterial effect of polyP, have a beneficial potential as wound dressings combining antimicrobial and regenerative (wound healing) properties.General significanceThe PLA-based fiber mats, containing retinol and polyP nanoparticles, provide promising bioactive meshes that are urgently needed as dressings for chronic wounds.