Effect of plant neutrophil elastase inhibitor on leucocyte migration, adhesion and cytokine release in inflammatory conditions

BACKGROUND AND PURPOSE

The serine and cysteine peptidase inhibitor, BbCI, isolated from Bauhinia bauhinioides seeds, is similar to the classical plant Kunitz inhibitor, STI, but lacks disulphide bridges and methionine residues. BbCI blocks activity of the serine peptidases, elastase (K_iapp 5.3 nM) and cathepsin G (K_iapp 160.0 nM), and the cysteine peptidase cathepsin L (K_iapp 0.2 nM). These three peptidases play important roles in the inflammatory process.

EXPERIMENTAL APPROACH

We measured the effects of BbCI on paw oedema and on leucocyte accumulation in pleurisy, both induced by carrageenan. Leucocyte–endothelial cell interactions in scrotal microvasculature in Wistar rats were investigated using intravital microscopy. Cytokine levels in pleural exudate and serum were measured by elisa.

KEY RESULTS

Pretreatment of the animals with BbCI (2.5 mg·kg⁻¹), 30 min before carrageenan-induced inflammation, effectively reduced paw oedema and bradykinin release, neutrophil migration into the pleural cavity. The number of rolling, adhered and migrated leucocytes at the spermatic fascia microcirculation following carrageenan injection into the scrotum were reduced by BbCI pretreatment. Furthermore, levels of the rat chemokine cytokine-induced neutrophil chemo-attractant-1 were significantly reduced in both pleural exudates and serum from animals pretreated with BbCI. Levels of interleukin-1β or tumour necrosis factor-α, however, did not change.

CONCLUSIONS AND IMPLICATIONS

Taken together, our data suggest that the anti-inflammatory properties of BbCI may be useful in investigations of other pathological processes in which human neutrophil elastase, cathepsin G and cathepsin L play important roles.     

The intermediate conductance Ca2+-activated K+ channel inhibitor TRAM-34 stimulates proliferation of breast cancer cells via activation of oestrogen receptors

Background and purpose:

K⁺ channels play a role in the proliferation of cancer cells. We have investigated the effects of specific K⁺ channel inhibitors on basal and oestrogen-stimulated proliferation of breast cancer cells.

Experimental approach:

Using the mammary adenocarcinoma cell line MCF-7 we assayed cell proliferation by radiolabelled thymidine incorporation in the absence or presence of various K⁺ channel inhibitors with or without 17β-oestradiol.

Key results:

Inhibitors of K_v10.1 and K_Ca3.1 K⁺ channels suppressed basal proliferation of MCF-7 cells, but not oestrogen-stimulated proliferation. TRAM-34, a specific inhibitor of K_Ca3.1 channels increased or decreased cell proliferation depending on the concentration. At intermediate concentrations (3–10 µM) TRAM-34 increased cell proliferation, whereas at higher concentrations (20–100 µM) TRAM-34 decreased cell proliferation. The enhancement of cell proliferation caused by TRAM-34 was blocked by the oestrogen receptor antagonists ICI182,780 and tamoxifen. TRAM-34 also increased progesterone receptor mRNA expression, decreased oestrogen receptor-α mRNA expression and reduced the binding of radiolabelled oestrogen to MCF-7 oestrogen receptor, in each case mimicking the effects of 17β-oestradiol.

Conclusions and implications:

Our results demonstrate that K⁺ channels K_v10.1 and K_Ca3.1 play a role in basal, but not oestrogen-stimulated MCF-7 cell proliferation. TRAM-34, as well as inhibiting K_Ca3.1, directly interacts with the oestrogen receptor and mimics the effects of 17β-oestradiol on MCF-7 cell proliferation and gene modulation. Our finding that TRAM-34 is able to activate the oestrogen receptor suggests a novel action of this supposedly specific K⁺ channel inhibitor and raises concerns of interpretation in its use.     

Hepatic manifestations of tuberous sclerosis complex: a genotypic and phenotypic analysis

Black ME, Hedgire SS, Camposano S, Paul E, Harisinghani M, Thiele EA. Hepatic manifestations of tuberous sclerosis complex: a genotypic and phenotypic analysis. A retrospective review of the clinical records and radiological images of 205 patients with tuberous sclerosis complex (TSC) was performed to evaluate the prevalence and progression of hepatic lesions; examine the association of hepatic phenotype with genotype, age, and gender; and investigate the relationships between hepatic, renal, and pulmonary involvement. Hepatic angiomyolipomas (AML), cysts, and other benign lesions were identified in 30% of the cohort, and some lesions grew significantly over time. However, no patient had clinical symptoms or complications from hepatic lesions. TSC2 patients exhibited a higher frequency of AML compared to TSC1 patients (p = 0.037), and patients with no mutation identified exhibited a higher frequency of cysts compared to TSC2 patients (p = 0.023). Age was positively correlated with frequency of hepatic involvement (p < 0.001), whereas hepatic phenotype was independent of gender. Presence of hepatic AML was associated with presence of renal AML (p = 0.001). These findings confirm a high rate of asymptomatic hepatic lesions in TSC and further characterize the TSC phenotype.     

Antidiabetic and haematological effect of aqueous extract of stem bark of Afzelia africana (Smith) on streptozotocin-induced diabetic Wistar rats

Objective

To investigate the antidiabetic properties of aqueous extract of stem bark of Afzelia africana (A. africana) and its beneficial effect on haematological parameters in streptozotocin induced diabetic rats.

Methods

A total of 30 rats including 24 diabetic and 6 normal rats were used for this study. Diabetes was induced in male Wistar rats by intraperitoneal injection of streptozotocin. After being confirmed diabetic, animals were orally treated with distilled water or extracts at 100 or 200 mg/kg body weight daily for 10 days. The haematological parameters including red blood and white blood cells and their functional indices were evaluated in diabetic treated groups compared with the controls.

Results

The extract significantly reduced the blood glucose levels while the best result was obtained at 200 mg/kg body weight. The feed and water intake in diabetic rats were significantly reduced while weight loss was minimized at both dosages. Similarly, the levels of red blood, white blood cells and their functional indices were significantly improved after extract administration at both doses.

Conclusions

It can be concluded that the aqueous extract of bark of A. africana possesses antihyperglycemic properties. In addition, the extract can prevent various complications of diabetes and improve some haematological parameters. Further experimental investigation is needed to exploit its relevant therapeutic effect to substantiate its ethnomedicinal usage.     

大鼠脑内心钠素的免疫组织化学观察

本文用兔抗心钠素Ⅲ特异血清,用ABC法观察了大鼠脑内心钠素的分布。结果表明心钠素在脑内广泛存在。密集的心钠素免疫反应阳性神经元,主要见于下丘脑视前区、室周核及下丘脑前核等处。密集的心钠素免疫反应阳性纤维布于下丘脑室旁核,终纹床核及终板血管器官等处。心钠素在脑内的分布状态提示心纳素可能具有中枢性调节水电解质平衡及心、血管的功能,此外,亦可能参与下丘脑—垂体系神经内分泌调节的作用。