槲皮素通过p53-p21-Rb通路缓解慢性阻塞性肺疾病的肺衰老

目的 探讨槲皮素对慢性阻塞性肺疾病(COPD)小鼠肺衰老的治疗作用及机制。方法 将30只C57BL/6小鼠随机分为对照组、模型组、槲皮素组,每组10只。模型组和槲皮素组采用烟熏联合气道内滴注脂多糖(LPS)的方法构建COPD小鼠模型。造模成功后,槲皮素组给予槲皮素(50 mg/kg)灌胃,1次/d,持续4周;对照组和模型组给予等体积生理盐水。采用苏木精-伊红(HE)染色法观察小鼠肺组织病理改变,并评估肺部病理损伤;采用衰老相关β-半乳糖苷酶(SA-β-gal)染色法观察小鼠肺组织的衰老状况;采用免疫组化法检测肺组织中凋亡相关蛋白Bcl-2、Bax表达情况;采用蛋白质印迹(Western blot)法检测肺组织中衰老相关蛋白p53、p21、Rb表达水平。结果 与对照组比较,模型组小鼠肺组织病理损伤明显,SA-β-gal染色的阳性面积明显增加,肺组织中Bcl-2蛋白表达减少、Bax蛋白表达增多,衰老相关蛋白p53、p21、Rb表达水平明显升高(均P<0.05);与模型组比较,槲皮素组小鼠肺组织病理损伤减轻,SA-β-gal染色阳性面积减少,肺组织中Bcl-2蛋白表达增高、Bax蛋白表...     

Is Bitterness Only a Taste? The Expanding Area of Health Benefits of Brassica Vegetables and Potential for Bitter Taste Receptors to Support Health Benefits

The list of known health benefits from inclusion of brassica vegetables in the diet is long and growing. Once limited to cancer prevention, a role for brassica in prevention of oxidative stress and anti-inflammation has aided in our understanding that brassica provide far broader benefits. These include prevention and treatment of chronic diseases of aging such as diabetes, neurological deterioration, and heart disease. Although animal and cell culture studies are consistent, clinical studies often show too great a variation to confirm these benefits in humans. In this review, we discuss causes of variation in clinical studies, focusing on the impact of the wide variation across humans in commensal bacterial composition, which potentially result in variations in microbial metabolism of glucosinolates. In addition, as research into host–microbiome interactions develops, a role for bitter-tasting receptors, termed T2Rs, in the gastrointestinal tract and their role in entero-endocrine hormone regulation is developing. Here, we summarize the growing literature on mechanisms of health benefits by brassica-derived isothiocyanates and the potential for extra-oral T2Rs as a novel mechanism that may in part describe the variability in response to brassica among free-living humans, not seen in research animal and cell culture studies.     

锰对大鼠生精细胞凋亡及p53和Bcl-2表达的影响

目的 研究氯化锰对大鼠生精细胞凋亡及p53、Bcl-2表达的影响.方法 将24只健康雄性SD大鼠随机分为3组,即15和30 mg/kg染锰组和0 mg/kg(阴性对照)组,腹腔注射给药,每天1次,每周5 d,连续4周.停药2周后,称重并应用电镜和原位末端脱氧核苷酸转移酶标记法(TUNEL法)检测睾丸生精细胞凋亡;免疫组化S-P法检测生精细胞p53和B淋巴细胞瘤/白血病-2(B-cell lymphoma/leukemia-2,Bcl-2)蛋白的表达.结果 电镜下各组大鼠可见生精细胞凋亡表现;15和30 mg/kg组生精细胞凋亡指数(apoptosis index,AI)和p53阳性细胞率均明显高于对照组,差异有统计学意义(P＜0.01),且30 mg/kg组高于15 mg/kg组,差异有统计学意义(P＜0.01).30 mg/kg组Bcl-2阳性细胞率明显低于0和15 mg/kg组,差异有统计学意义(P＜0.01).结论 锰可诱导大鼠生精细胞凋亡,p53表达上调和Bcl-2表达下调可能是生精细胞凋亡增加的重要原因之一.     

星形细胞肿瘤中的细胞凋亡及其与p53、bcl—2的关系

目的探讨细胞凋亡在星形细胞肿瘤发展中的作用及其与p53、bcl-2的关系.方法对52例星形细胞肿瘤标本分别进行HE染色,TUNEL及PCNA、p53、bc1-2免疫组化染色.结果高级别星形细胞肿瘤的PI(增殖指数)显著高于低级别肿瘤(P＜0.01);高级别肿瘤和低级别肿瘤间的AI(凋亡指数)无显著性差异(P＞0.05).高级别星形细胞肿瘤p53的表达高于低级别肿瘤(0.01＜P＜0.05);p53阴性组和p53阳性组的AI(P＞0.05)和PI(P＞0.05)无显著性差异.低级别肿瘤中bcl-2的表达较高级别组肿瘤高(0.01＜P＜0.05);bc1-2免疫组化染色表达的阳性组与阴性组的AI(P＞0.05)和PI(P＞0.05)无显著性差异.结论与低级别星形细胞肿瘤相比,高级别肿瘤中的细胞凋亡受到了抑制;p53免疫组化染色结果可作为分析星形细胞肿瘤生物学行为的参考指标.星形细胞肿瘤中bcl-2的过表达对细胞凋亡未产生明显影响.     

Mesenchymal Stem Cell–Derived Extracellular Vesicles Alleviate M1 Microglial Activation in Brain Injury of Mice With Subarachnoid Hemorrhage via microRNA-140-5p Delivery

BackgroundIt is documented that mesenchymal stem cells (MSCs) secrete extracellular vesicles (EVs) to modulate subarachnoid hemorrhage (SAH) development. miR-140-5p expression has been detected in MSC-derived EVs, while the mechanism of MSC-derived EVs containing miR-140-5p in SAH remains unknown. We aim to fill this void by establishing SAH mouse models and extracting MSCs and MSC-EVs.MethodsAfter ALK5 was silenced in SAH mice, neurological function was evaluated, neuron apoptosis was detected by TdT-mediated dUTP-biotin nick end labeling with NeuN staining, and expression of serum inflammatory factors (interleukin-6, interleukin-1β, and tumor necrosis factor-α) was determined by enzyme-linked immunosorbent assay. The effect of ALK5 on NOX2 expression was assessed by western-blot analysis. Targeting the relationship between miR-140-5p and ALK5 was evaluated by dual luciferase assay. Following extraction of MSCs and MSC-EVs, EVs and miR-140-5p were labeled by PKH67 and Cy3, respectively, to identify the transferring of miR-140-5p by MSC-EVs. SAH mice were treated with EVs from miR-140-5p mimic/inhibitor-transfected MSCs to detect effects of MSC-EV-miR-140-5p on brain injury and microglial polarization.ResultsALK5 silencing increased the neurological score and reduced neuron apoptosis and neuroinflammation in SAH mice. ALK5 silencing inhibited M1 microglia activation by inactivating NOX2. ALK5 was a target gene of miR-140-5p. MSC-derived EVs contained miR-140-5p and transferred miR-140-5p into microglia. MSC-EV-delivered miR-140-3p reduced ALK5 expression to contribute to repression of brain injury and M1 microglia activation in SAH mice.ConclusionsMSC-derived EVs transferred miR-140-5p into microglia to downregulate ALK5 and NOX2, thus inhibiting M1 microglia activation in SAH mice.     

The E3 Ligase RNF157 Inhibits Lens Epithelial Cell Apoptosis by Negatively Regulating p53 in Age-Related Cataracts

PurposeAge-related cataract (ARC) is a major cause of vision impairment worldwide. The E3 ubiquitin ligase RING finger protein 157 (RNF157) is involved in regulating cell survival and downregulated in human cataractous lens samples. However, the function of RNF157 in cataracts remains unclear. This study aimed to determine the role of RNF157 in ARC.MethodsReal-time polymerase chain reaction (PCR) and Western blotting were used to analyze the expression of RNF157 in clinical lens capsules, rat cataract models, and oxidative stress cell models. Western blot analysis and flow cytometry were used to evaluate cell apoptosis. Co-IP assay, protein stability assay, and ubiquitination assay were used to detect the interaction between RNF157 and its substrate p53.ResultsThe expression of RNF157 was downregulated in human cataract samples, UVB-induced rat cataract model, and H₂O₂-treated human lens epithelial cells (LECs). Ectopic expression of RNF157 protected LECs from H₂O₂-induced apoptosis. In contrast, knockdown of RNF157 enhanced oxidative stress-induced apoptotic cell death. Moreover, silence of RNF157 in the rat ex vivo lens model exacerbated lens opacity. Mechanistically, RNF157 causes ubiquitination and degradation of the tumor antigen p53. Overexpression of p53 eliminated the antiapoptotic effects of RNF157, whereas p53 knockdown rescued RNF157 silencing-induced cell death.ConclusionsOur findings revealed that reduced RNF157 expression promoted LEC apoptosis by upregulating p53 in cataracts, suggesting that the regulation of RNF157 expression may serve as a potential therapeutic strategy for cataracts.     

Resolvin D1 attenuates imiquimod-induced mice psoriasiform dermatitis through MAPKs and NF-κB pathways

Background

Resolvin D1 (RvD1), a pro-resolution lipid mediator derived from docosahexaenoic acid (DHA), has been described to promote several kinds of inflammatory resolution. However, the effects and anti-inflammatory mechanisms of RvD1 on psoriasis have not been previously reported.

系统性红斑狼疮患者骨髓间充质干细胞的生物学特征及其p27kip1/PTEN蛋白表达

目的 探讨系统性红斑狼疮(SLE)患者骨髓间充质干细胞(BMSC)的生物学行为,证实SLE患者BMSC是衰老的干细胞,并探讨其衰老的可能机制.方法 用密度梯度离心和贴壁分离法对6例SLE患者和8例健康人BMSC进行分离培养.光学显微镜观察BMSC形态学改变及生长状况并绘制生长曲线,诱导成骨、成脂分化检测BMSC分化能力,流式细胞仪鉴定BMSC表面标志物及分析细胞凋亡和细胞周期,划痕试验检测BMSC迁移能力,免疫荧光法及蛋白印迹法分析BMSC内p27kip1/PTEN的分布及表达.结果 SLE患者组BMSC形态宽大、扁平、呈多角形,与健康对照组相比,其生长速率、迁移及成骨成脂分化能力均明显降低.SLE组处于早期(Q2)、中晚期(Q4)凋亡的BMSC细胞比例(17.98％±3.26％,16.80％±9.63％)显著高于健康对照组(8.23％±3.25％,3.33％±2.21％),差异有统计学意义(tQ2=3.91,PQ2=0.011;tQ4=2.99,PQ4=0.048).SLE组BMSC阻滞于G0/G1期的细胞百分比显著高于健康对照组(92.34％±5.80％比78.65％±3.22％,t=3.635,P=0.015),同时其S期所占细胞百分比明显低于健康对照组(0.86％±1.72％比5.06％±1.874％;t=3.084,P=0.027).SLE患者BMSC经内参均一化后的p27、PTEN蛋白表达水平(即p27/β肌动蛋白,PTEN/β肌动蛋白)均高于健康对照者,差异有统计学意义(tp27=2.784,PP27=0.039;tPTEN=4.812,PPTEN=0.041).结论 SLE患者BMSCs表现出衰老特征,可能与细胞内p27kip1/PTEN表达水平升高有关.     

皮脂腺肿瘤p53及bcl-2蛋白表达的研究

目的研究ｐ５３及ｂｃｌ ２基因在皮脂腺肿瘤中的作用。方法应用免疫组化方法对皮脂腺良、恶性肿瘤上述两种基因产物的表达进行了检测。结果５例皮脂腺癌、２例皮脂腺痣和２例皮脂腺增生症均不同程度表达ｂｃｌ ２蛋白,而ｐ５３蛋白仅表达于５例皮脂腺癌的癌细胞。两种蛋白表达强度无相关关系（ｒ’ｓ＝０．１０５,Ｐ＞０．０５）。结论ｐ５３基因突变在皮脂腺癌发生中起决定性作用,而ｂｃｌ ２基因则起协同促进作用。检测ｐ５３蛋白可用于鉴别皮脂腺良、恶性肿瘤。     

Penetration and haptenation of p‐phenylenediamine

Although p‐phenylenediamine (PPD) has been recognized as an extreme sensitizer for many years, the exact mechanism of sensitization has not been elucidated yet. Penetration and the ability to bind to proteins are the first two hurdles that an allergen has to overcome to be able to sensitize. This review is an overview of studies regarding PPD penetration through skin (analogues) and studies on the amino acids that are targeted by PPD. To complete this review, the auto‐oxidation and N‐acetylation steps involved in PPD metabolism are described. In summary, under normal hair dyeing exposure conditions, <1% of the applied PPD dose penetrates the skin. The majority (>80%) of PPD that penetrates will be converted into the detoxification products monoacetyl‐PPD and diacetyl‐PPD by the N‐acetyltransferase enzymes. The small amount of PPD that does not become N‐acetylated is susceptible to auto‐oxidation reactions, yielding protein‐reactive PPD derivatives. These derivatives may bind to specific amino acids, and some of the formed adducts might be the complexes responsible for sensitization. However, true in vivo evidence is lacking, and further research to unravel the definite mechanism of sensitization is needed.