Effect of the bradykinin 1 receptor antagonist SSR240612 after oral administration in Mycobacterium tuberculosis-infected mice

Assessment of Radiolabelled Derivatives of R954 for Detection of Bradykinin B1 Receptor in Cancer Cells: Studies on Glioblastoma Xenografts in Mice

Bradykinin B1 receptor (B1R) has garnered attention as a cancer therapeutic and diagnostic target. Several reports on radiolabelled derivatives of B1R antagonists have shown favourable properties as imaging agents in cells highly expressing hB1R following transfection. In the present study, we assessed whether radiolabelled probes can detect B1R endogenously expressed in cancer cells. To this end, we evaluated 111In-labelled derivatives of a B1R antagonist ([111In]In-DOTA-Ahx-R954) using glioblastoma cell lines (U87MG and U251MG) with different B1R expression levels. Cellular uptake studies showed that the specific accumulation of [111In]In-DOTA-Ahx-R954 in U87MG was higher than that in U251MG, which correlated with B1R expression levels. Tissue distribution in U87MG-bearing mice revealed approximately 2-fold higher radioactivity in tumours than in the muscle in the contralateral leg. The specific accumulation of [111In]In-DOTA-Ahx-R954 in the tumour was demonstrated by the reduction in the tumour-to-plasma ratios in nonlabelled R954-treated mice. Moreover, ex vivo autoradiographic images revealed that the intratumoural distribution of [111In]In-DOTA-Ahx-R954 correlated with the localisation of B1R-expressing glioblastoma cells. In conclusion, we demonstrated that [111In]In-DOTA-Ahx-R954 radioactivity correlated with B1R expression in glioblastoma cells, indicating that radiolabelled derivatives of the B1R antagonist could serve as promising tools for elucidating the involvement of B1R in cancer.

Kinins and Their Receptors in Infectious Diseases

Kinins and their receptors have been implicated in a series of pathological alterations, representing attractive pharmacological targets for several diseases. The present review article aims to discuss the role of the kinin system in infectious diseases. Literature data provides compelling evidence about the participation of kinins in infections caused by diverse agents, including viral, bacterial, fungal, protozoan, and helminth-related ills. It is tempting to propose that modulation of kinin actions and production might be an adjuvant strategy for management of infection-related complications.

A Systematic Review of Molecular Imaging Agents Targeting Bradykinin B1 and B2 Receptors

Kinins, bradykinin and kallidin are vasoactive peptides that signal through the bradykinin B1 and B2 receptors (B1R and B2R). B2R is constitutively expressed in healthy tissues and mediates responses such as vasodilation, fluid balance and retention, smooth muscle contraction, and algesia, while B1R is absent in normal tissues and is induced by tissue trauma or inflammation. B2R is activated by kinins, while B1R is activated by kinins that lack the C-terminal arginine residue. Perturbations of the kinin system have been implicated in inflammation, chronic pain, vasculopathy, neuropathy, obesity, diabetes, and cancer. In general, excess activation and signaling of the kinin system lead to a pro-inflammatory state. Depending on the disease context, agonism or antagonism of the bradykinin receptors have been considered as therapeutic options. In this review, we summarize molecular imaging agents targeting these G protein-coupled receptors, including optical and radioactive probes that have been used to interrogate B1R/B2R expression at the cellular and anatomical levels, respectively. Several of these preclinical agents, described herein, have the potential to guide therapeutic interventions for these receptors.