人组织激肽释放酶基因对2型糖尿病大鼠血压的影响及机制

目的：探讨人组织激肽释放酶（HK）基因对2型糖尿病大鼠血压的影响及其机制。方法:高脂高糖饮食加小剂量链脲佐菌素建立2型糖尿病动物模型。以重组腺相关病毒为载体介导HK基因（HK组）或对照基因LacZ（LacZ组）在糖尿病大鼠体内表达，观察实验动物血压变化及离体主动脉对乙酰胆碱（Ach）依赖性血管舒张反应和一氧化氮（NO）、内皮素-1（ET-1）、内皮素受体A（ETA-R）表达。 结果:(1) HK组第2周开始出现血压下降，并一直持续到实验结束（12周时），而LacZ组血压无明显下降。(2) LacZ组离体主动脉对乙酰胆碱（Ach）依赖性血管舒张反应明显低于HK组。(3) HK组大鼠主动脉NO2-/NO3-浓度明显高于LacZ组，而ET-1和ETA-R mRNA明显低于LacZ组。 结论:重组腺相关病毒介导HK基因表达明显降低2型糖尿病大鼠血压，改善内皮依赖性血管舒张功能，原因可能与增加动脉NO释放，减少ET-1和ETA-R的表达有关。     

Differential expression of the human kallikrein gene 14 (KLK14) in normal and cancerous prostatic tissues

BACKGROUND: Many members of the human kallikrein gene family are differentially expressed in cancer and a few have potential as diagnostic/prognostic markers. KLK14 is a newly discovered human kallikrein gene that is mainly expressed in the central nervous system and endocrine tissues. Since KLK14 was found to be regulated by steroid hormones in prostate cancer cell lines, we hypothesized that it will be differentially expressed in prostate cancer tissues compared to their normal counterparts. METHODS: Matched prostate tissue samples from the cancerous and non-cancerous parts of the same prostates were obtained from 100 patients who underwent radical prostatectomy. Quantitative analysis of KLK14 expression levels were performed by real-time RT-PCR using SYBR Green I dye on the LightCycler trade mark system. Associations with clinico-pathological parameters were analyzed. RESULTS: KLK14 overexpression in the cancerous compared to non-cancerous tissue was found in 74% of patients (P < 0.001). Mean level of expression was 154 arbitrary units (Au) in cancerous tissues and 14.2 Au in the non-cancerous tissues. The ratio of the cancerous to non-cancerous KLK14 expression values was higher in patients with late stage (stage III) compared to stage II (P = 0.002), and in grade 3 compared to grade 1/2 tumors (P = 0.001). A statistically significant increase was also observed in patients with higher in Gleason score (>6) compared to Gleason score = 6 tumors (P = 0.027). No correlation was found between KLK14 tissue expression levels and serum prostate-specific antigen. CONCLUSIONS: KLK14 expression is significantly higher in cancerous compared to non-cancerous prostatic tissue. The up-regulation of the KLK14 gene in advanced and more aggressive tumors may indicate a possible role for the hK14 protein in tumor spread and opens the possibility of hK14 being a candidate new marker for prostate cancer diagnosis and prognosis.     

Altered kallikrein 7 and 10 concentrations in cerebrospinal fluid of patients with Alzheimer's disease and frontotemporal dementia

BACKGROUND: The role of various proteases in the pathogenesis of Alzheimer's disease is well documented. Recently, many members of the human tissue kallikrein family, a group of 15 secreted serine proteases, were found to be highly expressed in the central nervous system (CNS). Some of these enzymes can be measured in cerebrospinal fluid (CSF) by using ELISA-type methodologies. METHODS: We quantified various kallikreins in CSF of 20 patients with Alzheimer's disease (AD), 16 patients with frontotemporal dementia (FTD), and 15 controls. We then correlated the levels of various kallikreins with presence of AD or FTD. Among all kallikreins measured, detectable levels in CSF were identified for kallikreins hK6, hK7, and hK10. Other tested kallikreins (hK5, hK8, hK11, and hK13) were unmeasurable. The most notable differences between kallikrein levels in CSF and the three groups of subjects were seen between controls and FTD patients for hK6 (decrease in FTD; P = 0.017), controls and FTD patients for hK7 (decrease in FTD; P < 0.001), and controls and AD patients for hK7 (decrease in AD; P = 0.019). In addition, significant differences were seen between FTD patients or control subjects and patients with AD patients for hK10 (increase in AD; P < 0.02). Approximately half of the AD patients had CSF hK10 levels that were higher than all patients with FTD except one and all control subjects except two. Various kallikrein concentrations in CSF were correlated, the strongest correlation seen between hK6 and hK7 (r(s) = 0.58). We also observed a statistically significant association between decreasing hK7 concentration in CSF and possession of one or two ApoE4 alleles (P = 0.014). CONCLUSIONS: We demonstrate for the first time significant alterations of hK6, hK7, and hK10 concentration in CSF of patients with AD and FTD. Notably, all three kallikreins (hK6, hK7, and hK10) are decreased in CSF of FTD patients and hK10 is increased in CSF of AD patients, in comparison to control subjects. The possible connection between these enzymes and the pathogenesis and progression of AD and FTD needs to be further investigated.     

Total and free PSA kinetics in patients without prostate cancer undergoing radical cystoprostatectomy

BACKGROUND: Radical cystoprostatectomy and radical prostatectomy are the two major operations where prostate is totally and radically removed. Radical cystoprostatectomy is usually performed in patients with invasive bladder cancer. The aim of the study was to examine Total PSA, Free PSA, and Free/Total Ratio elimination kinetics after radical cystoprostatectomy. METHODS: Serum PSA, Free PSA, and Free/Total Ratio were determined preoperatively, at the time of cystoprostatectomy specimen removal and then at 3, 6, 12, 24, 48, 72, and 168 hr, from seven patients with muscle invasive bladder cancer, who underwent radical cystoprostatectomy. Free and Total PSA concentrations were measured with non-competitive immunological procedures. The elimination rates and half-lives of Total, Free PSA and Free/Total Ratio were studied using a nonlinear regression analysis. RESULTS: Surgical manipulations caused about 1.5-fold increase of PSA, 5-fold increase in Free PSA and 3-fold increase in Free/Total Ratio. PSA and Free PSA followed a biphasic elimination pattern of a rapid exponential (a) phase with a half-life of 4.27 and 2.14 hr and a terminal, nonexponential (b) phase with a half-life of 63 and 173.2 hr, respectively. Free/Total PSA Ratio followed, also, a biphasic kinetic pattern of a rapid exponential decline with a half-life of 3.34 and a terminal non-exponential increase with a doubling time of 43 hr. CONCLUSIONS: Comparing PSA kinetics after radical cystoprostatectomy with those of radical prostatectomy, it appears that PSA follows the same elimination pattern in both models. In contrast, Free PSA and Free/Total Ratio elimination kinetics' patterns differ between the two surgical models.     

COMMENTS

Human tissue kallikreins are fifteen homologous genes encoding for secreted serine proteases and residing tandemly on chromosome 19q13.4. These enzymes are highly expressed in a variety of tissues and participate in diverse physiological processes. Human tissue kallikreins were found to be associated with several malignancies, especially endocrine-related cancers, including prostate, ovarian, breast and testicular cancer. In testicular germ cell tumors, some tissue kallikrein genes, including KLK5, KLK10, KLK13 and KLK14, were found to be significantly down-regulated. Tissue-specific splice variant forms of some kallikreins have been identified in the testis. In this paper, the expression of KLK5, KLK10, KLK13 and KLK14 in testicular cancer and their possible roles during testicular cancer development, as well as their clinical applications are briefly reviewed.     

Kallikrein 4 is a potential mediator of cellular interactions between cancer cells and osteoblasts in metastatic prostate cancer

BACKGROUND: Prostate cancer (PCa) and bone cell interactions are critical in the metastatic phase. Kallikrein 4 (KLK4/hK4) is expressed in both PCa and mineralized tissues. We determined if KLK4/hK4 expression was associated with, and influenced by, the bone environment of metastatic PCa. METHODS: Immunohistochemistry, in vitro co-culture, cell migration, and attachment assays. RESULTS: hK4 was localized to tumor cells and osteoblasts in bone metastases. KLK4/hK4 increased in LNCaP and PC3 cells co-cultured with SaOs2 cells; SaOs2 KLK4/hK4 was unchanged. Co-culture did not affect cell proliferation but altered alkaline phosphatase activity/mRNA levels in SaOs2 cells. KLK4-transfected PC3 cells had increased migration towards SaOs2 conditioned medium and greater attachment to the bone-matrix proteins, collagens I and IV. CONCLUSIONS: hK4 expression and interaction with both tumor cells and osteoblasts suggests a role for hK4 in PCa bone metastasis. Whether this observation is unique to bone metastasis or reflects a role for hK4 in PCa metastasis generally is yet to be established.     

人尿激肽原酶联合血小板抑制剂治疗脑梗死患者的疗效观察

目的人尿激肽原酶(尤瑞克林)联合血小板抑制剂治疗脑梗死患者的疗效观察。方法 88例脑梗死患者随机分为治疗组和对照组,每组44例。在对症治疗的基础上,对照组患者给予拜阿司匹林200～300mg/d,治疗组患者在对照组基础上加用尤瑞克林0.15 PNAU/d静脉滴注。两组疗程均为7天。用美国国立卫生研究院脑卒中量表(NIHSS)评估患者神经功能缺损,并观察凝血功能、血压变化。结果两组患者治疗前后凝血功能变化,差异无统计学意义(P>0.05)。与治疗前比较,两组患者治疗后NIHSS评分明显下降,差异有统计学意义(P<0.05),且治疗组较对照组NIHSS评分下降更明显(P<0.05),治疗组高血压患者在应用尤瑞克林治疗期间血压无明显波动(P>0.05)。结论尤瑞克林联合血小板抑制剂能有效治疗脑梗死.且安全性良好。     

组织激肽释放酶1改善大鼠心脏缺血/再灌注损伤后线粒体功能障碍

目的 探讨组织激肽释放酶1（KLK1）对心脏缺血/再灌注损伤大鼠线粒体功能的影响及其机制。方法 通过KLK1重组腺病毒感染实现大鼠心脏KLK1过表达,然后采用冠状动脉左前降支结扎和再灌注的方法建立大鼠心脏缺血/再灌注损伤模型,检测梗死区面积和心脏缺血危险区细胞凋亡情况;分离大鼠心脏缺血危险区心肌组织线粒体,检测线粒体功能（线粒体过氧化物生成量、线粒体膜电位、线粒体ATP生成量）。分离新生大鼠心肌细胞,通过KLK1重组腺病毒感染实现KLK1过表达,然后建立心肌细胞缺氧/复氧损伤模型,对心肌细胞缺氧/复氧损伤模型应用缓激肽1型受体（B1R）阻断剂R715或缓激肽2型受体（B2R）阻断剂HOE140处理,利用MTT法检测细胞活力,并观察线粒体功能的变化。结果 在大鼠心脏缺血/再灌注损伤模型中,KLK1过表达能减轻心肌缺血/再灌注损伤,使心肌梗死区面积减小、缺血危险区细胞凋亡减少（P均<0.01）;改善心脏缺血/再灌注损伤后线粒体功能障碍,降低过氧化物生成量、增加线粒体膜电位和线粒体ATP生成量（P均<0.01）。在离体大鼠心肌细胞缺氧/复氧模型中,KLK1过表达能减轻心肌细胞损伤（P<0.05）、改善线粒体功能障碍（P<0.05,P<0.01）,并且其作用可被B2R阻断剂HOE140抑制。结论 KLK1能改善心脏缺血/再灌注损伤后线粒体功能障碍,这可能是其具有心脏保护作用的重要机制。