Inhibition of C5aR1 as a promising approach to treat taxane-induced neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of several antitumor agents resulting in progressive and often irreversible damage of peripheral nerves. In addition to their known anticancer effects, taxanes, including paclitaxel, can also induce peripheral neuropathy by activating microglia and astrocytes, which release pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1β), and chemokine (C-C motif) ligand 2 (CCL-2). All these events contribute to the maintenance of neuropathic or inflammatory response. Complement component 5a (C5a)/C5a receptor 1 (C5aR1) signaling was very recently shown to play a crucial role in paclitaxel-induced peripheral neuropathy. Our recent findings highlighted that taxanes have the previously unreported property of binding and activating C5aR1, and that C5aR1 inhibition by DF3966A is effective in preventing paclitaxel-induced peripheral neuropathy (PIPN) in animal models. Here, we investigated if C5aR1 inhibition maintains efficacy in reducing PIPN in a therapeutic setting. Furthermore, we characterized the role of C5aR1 activation by paclitaxel and the CIPN-associated activation of nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome. Our results clearly show that administration of the C5aR1 inhibitor strongly reduced cold and mechanical allodynia in mice when given both during the onset of PIPN and when neuropathy is well established. C5aR1 activation by paclitaxel was found to be a key event in the induction of inflammatory factors in spinal cord, such as TNF-α, ionized calcium-binding adapter molecule 1 (Iba-1), and glial fibrillary acidic protein (GFAP). In addition, C5aR1 inhibition significantly mitigated paclitaxel-induced inflammation and inflammasome activation by reducing IL-1β and NLRP3 expression at both sciatic and dorsal root ganglia level, confirming the involvement of inflammasome in PIPN. Moreover, paclitaxel-induced upregulation of C5aR1 was significantly reduced by DF3966A treatment in central nervous system. Lastly, the antinociceptive effect of C5aR1 inhibition was confirmed in an in vitro model of sensory neurons in which we focused on receptor channels usually activated upon neuropathy. In conclusion, C5aR1 inhibition is proposed as a therapeutic option with the potential to exert long-term protective effect on PIPN-associated neuropathic pain and inflammation.

The role of mesotherapy in the management of spinal pain. A randomized controlled study

Background

Mesotherapy is a technique through which active ingredients are administered into the thickness of the skin in order to increase the local analgesic effect.

Methods

141 patients with spinal pain not responding to systemic therapy with NSAIDs were randomized to receive one or more intra-cutaneous drugs on a weekly basis.

Results

All patients achieved a pain reduction of at least 50% compared to baseline, and all tolerated the therapy without having to resort to systemic drug dose increases.

Conclusions

The data from our study show that the active ingredients infiltrated into the skin induce a mesodermal modulation between the infiltrated liquid and the cutaneous nervous and cellular structures from which the typical drug-saving effect of mesotherapy arises. Although further studies are needed to establish how to integrate mesotherapy in various clinical settings, it appears to be a useful technique available to the practicing physician. This research is also useful in guiding future clinical research.

UniPR129 is a competitive small molecule Eph-ephrin antagonist blocking in vitro angiogenesis at low micromolar concentrations

BACKGROUND AND PURPOSE

The Eph receptor tyrosine kinases and their ephrin ligands are key players in tumorigenesis and many reports have correlated changes in their expression with a poor clinical prognosis in many solid tumours. Agents targeting the Eph-ephrin system might emerge as new tools useful for the inhibition of different components of cancer progression. Even if different classes of small molecules targeting Eph-ephrin interactions have been reported, their use is hampered by poor chemical stability and low potency. Stable and potent ligands are crucial to achieve robust pharmacological performance.

EXPERIMENTAL APPROACH

UniPR129 (the L-homo-Trp conjugate of lithocholic acid) was designed by means of computational methods, synthetized and tested for its ability to inhibit the interaction between the EphA2 receptor and the ephrin-A1 ligand in an elisa binding study. The ability of UniPR129 to disrupt EphA2-ephrin-A1 interaction was functionally evaluated in a prostate adenocarcinoma cell line and its anti-angiogenic effect was tested in vitro using cultures of HUVECs.

KEY RESULTS

UniPR129 disrupted EphA2-ephrin-A1 interaction with Ki = 370 nM in an elisa binding assay and with low micromolar potency in cellular functional assays, including inhibition of EphA2 activation, inhibition of PC3 cell rounding and disruption of in vitro angiogenesis, without cytotoxic effects.

CONCLUSIONS AND IMPLICATIONS

The discovery of UniPR129 represents not only a major advance in potency compared with the existing Eph-ephrin antagonists but also an improvement in terms of cytotoxicity, making this molecule a useful pharmacological tool and a promising lead compound.

Preseasonal specific immunotherapy with modified phleum pratense allergenic extracts: tolerability and effects

The preparation of chemically modified allergens, with a reduced IgE binding capacity (responsible for side effects with traditional immunotherapy) but with the same or greater immunogenic activity, is one of the paths followed to obtain better results with specific immunotherapy (IT). The aim of the study was to evaluate the tolerability and effects of extracts of Phleum pratense, modified with glutaraldehyde and absorbed on aluminium hydroxide, in controlling the seasonal symptomatology induced by grass pollen in a group of 10 monosensitized patients, compared to a group of 10 similar patients not treated with specific IT but with drugs alone. The monitoring parameters were: 1) Clinical: a) symptomatology after specific conjuctival provocation test (pre and post seasonal) and during the natural exposure to the allergen b) drug consumption. 2) Immunological (peripheral blood eosinophils, total and specific IgE, total specific IgG). 3) Cytological, before, during and after the pollen season.

CONCLUSIONS

in subjects treated with specific IT a) both the overall symptomatology and the drug consumption resulted significantly reduced compared to the controls (p = 0.045); b) the phlogistic infiltrate showed a tendency to decrease during the pollen season; c) the peripheral blood eosinophils, total and specific IgE and IgG did not show any significant variation compared to the controls; d) no systemic reactions occurred and there were only two slight local reactions.

Community outbreak of Legionnaires' disease: an investigation confirming the potential for cooling towers to transmit Legionella species

In August and September 1993, we investigated an outbreak of legionnaires' disease in Fall River, Massachusetts, that involved 11 persons; the attack rate was highest in Flint, a community of Fall River. All cases were infected with Legionella pneumophila serogroup 1 (Lp-1). A case-control study revealed that cases were more likely than matched controls to have visited sites in neighborhood A of Flint. Environmental sampling in Flint found that four of nine aerosol-producing devices sampled contained legionellae; only two, conjoined cooling towers on building A, contained Lp-1. Three independent methods of subtyping--monoclonal antibody subtyping, arbitrary primer polymerase chain reaction, and pulsed-field gel electrophoresis--revealed that Lp-1 isolates from three cases with culture-positive legionnaires' disease matched those from the cooling towers on building A. Water samples from the homes of cases with culture-positive legionnaires' disease contained no legionellae. The results of this epidemiologic and laboratory investigation indicate that the cooling towers on building A were the source of the outbreak of legionnaires' disease and confirm the importance of cooling towers in the transmission of legionnaires' disease.

Comparison of Legionella pneumophila isolates by arbitrarily primed PCR and pulsed-field gel electrophoresis: analysis from seven epidemic investigations

Arbitrarily primed PCR (AP-PCR) and pulsed-field gel electrophoresis (PFGE) subtyping were applied to clinical and environmental isolates from seven unrelated outbreaks of Legionnaires' disease. The patterns observed with each method matched patient isolates and the epidemiologically linked source of disease for each of the seven outbreaks. PFGE allowed more discrimination among various isolates, although AP-PCR usually gave comparable results. With both methods, certain patterns appeared to predominate in the comparison of the seven outbreaks. Of five clinical isolates not associated with the outbreaks, three gave profiles distinct from those observed in the outbreaks by both methods. This suggests that there are at least two predominant subtypes of Legionella pneumophila serogroup 1 associated with outbreaks. Investigations of outbreaks of legionellosis should employ either PFGE or AP-PCR in addition to monoclonal antibody analysis.

Controlling vancomycin-resistant enterococci

After controlling an epidemic of vanB-type vancomycin-resistant Enterococcus faecium (VRE), we contained a subsequent vanA E faecium outbreak by using prospective laboratory-based surveillance, placing patients with VRE in private rooms, requiring the use of both gowns and gloves by all personnel entering the patients' rooms, and conducting prevalence surveys of patients on affected wards.

IS6770, an enterococcal insertion-like sequence useful for determining the clonal relationship of clinical enterococcal isolates

Enterococci expressing resistance to antimicrobial agents are increasingly important nosocomial pathogens. Effective strategies to prevent or abort outbreaks of resistant enterococcal infection will rely on an accurate understanding of the mechanisms by which these organisms spread. A 1065-bp insertion-like sequence (IS6770) is present in varying copy numbers in > 90% of enterococcal strains thus far examined. Hybridization patterns resulting from hybridization of enterococcal genomic DNA with an internal IS6770 probe vary considerably between unrelated strains and correlate well with results of pulsed-field gel electrophoresis and field-inversion gel electrophoresis in identifying clonal relationships among enterococcal isolates. IS6770 analysis of several outbreaks of resistant enterococci has confirmed the spread of single resistant clones rather than the emergence of resistance within the resident flora. These results suggest that IS6770 hybridization will be a useful tool for tracing the epidemiology of nosocomial enterococcal infections.

A pseudo-epidemic involving bone allografts

Preimplantation cultures of four sterile bone allograft specimens grew Comomonas acidovorans and Pseudomonas species. An epidemiological investigation, including molecular subtyping methods, revealed that the allograft specimens were contaminated in a microbiology laboratory sonicator water bath.

Current concepts on myocardial depressant factor

In the present work the authors have tried to offer a vast and detailed summary of theories and questions concerning the role of the MDF in shock. One of the major problems that surrounds this molecule is the myocardial contractility depression, the solution of which could allow a more rationalistic therapeutic approach to that which remains one of the most complex and delicate clinical framework.