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-1ß), 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-1ß 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.

Comparison of sulfolane effects in Sprague Dawley rats, B6C3F1/N mice, and Hartley guinea pigs after 28 days of exposure via oral gavage.

Sulfolane is a solvent used in industrial refining with identified environmental exposure in drinking water. Due to potential large species differences, the National Toxicology Program (NTP) conducted 28-day toxicity studies in male and female Hsd:Sprague Dawley® SD® rats, B6C3F1/N mice, and Hartley guinea pigs. A wide dose range of 0, 1, 10, 30, 100, 300, and 800 mg/kg was administered via gavage. Histopathology, clinical pathology, and organ weights were evaluated after 28 days of exposure. In addition, plasma concentrations of sulfolane were evaluated 2 and 24 h after the last dose. Increased mortality was observed in the highest dose group of guinea pigs and mice while decreased body weight was observed in rats compared to controls. Histopathological lesions were observed in the kidney (male rat), stomach (male mice), esophagus (male and female guinea pigs), and nose (male guinea pigs). Plasma concentrations were generally higher in rats and guinea pigs compared to mice with evidence of saturated clearance at higher doses. Male rats appear to be the most sensitive with hyaline droplet accumulation occurring at all doses, although the human relevance of this finding is questionable.

Immunohistochemical Expression of Cyclin D1, Cytokeratin 20, and Uroplakin III in Proliferative Urinary Bladder Lesions Induced by o-Nitroanisole in Fischer 344/N Rats.

o-Nitroanisole is an intermediate in the manufacture of azo dyes. In a National Toxicology Program stop-exposure study,o-nitroanisole induced hyperplasia, papillomas, and papillary carcinomas in the urinary bladder of Fischer 344/N rats.o-Nitroanisole was investigated since occupational or environmental exposure to aniline and azo dyes is a risk factor for urinary bladder cancer in humans. The current study describes the morphology of urinary bladder neoplasms seen in rats with respect to those observed in humans. This study also evaluated immunohistochemical expression of the cell cycle-related proteins cyclin D1 and p53 and the differentiation markers cytokeratin 20 and uroplakin III in hyperplastic (n= 11) and neoplastic (n= 6 papillomas,n= 11 carcinomas) lesions of the urinary bladder epithelium from rats treated with o-nitroanisole and in normal (n= 6) urinary bladders from untreated rats. The tumors observed were more similar to the papillary type rather than the muscle-invasive type of urinary bladder cancer in humans. The preneoplastic and neoplastic lesions observed suggest progression from hyperplasia to papilloma to papillary carcinoma. With neoplastic progression (hyperplasia to papilloma to carcinoma), cyclin D1 immunoreactivity progressively increased in intensity, percentage of cells staining, and distribution. Overexpression of p53 was not found. Cytokeratin 20 staining decreased in superficial cells, while uroplakin III staining increased in intermediate and basal cells with progression from hyperplasia to carcinoma. The results are consistent with increased cell cycle dysregulation or proliferation (cyclin D1), decreased differentiation (cytokeratin 20), and abnormal differentiation (uroplakin III) as lesions progress toward malignancy.

Receptor binding mode and pharmacological characterization of a potent and selective dual CXCR1/CXCR2 non-competitive allosteric inhibitor.

BACKGROUND AND PURPOSE: DF 2156A is a new dual inhibitor of IL-8 receptors CXCR1 and CXCR2 with an optimal pharmacokinetic profile. We characterized its binding mode, molecular mechanism of action and selectivity, and evaluated its therapeutic potential. EXPERIMENTAL APPROACH: The binding mode, molecular mechanism of action and selectivity were investigated using chemotaxis of L1.2 transfectants and human leucocytes, in addition to radioligand and [(35) S]-GTPγS binding approaches. The therapeutic potential of DF 2156A was evaluated in acute (liver ischaemia and reperfusion) and chronic (sponge-induced angiogenesis) experimental models of inflammation. KEY RESULTS: A network of polar interactions stabilized by a direct ionic bond between DF 2156A and Lys(99) on CXCR1 and the non-conserved residue Asp(293) on CXCR2 are the key determinants of DF 2156A binding. DF 2156A acted as a non-competitive allosteric inhibitor blocking the signal transduction leading to chemotaxis without altering the binding affinity of natural ligands. DF 2156A effectively and selectively inhibited CXCR1/CXCR2-mediated chemotaxis of L1.2 transfectants and leucocytes. In a murine model of sponge-induced angiogenesis, DF 2156A reduced leucocyte influx, TNF-α production and neovessel formation. In vitro, DF 2156A prevented proliferation, migration and capillary-like organization of HUVECs in response to human IL-8. In a rat model of liver ischaemia and reperfusion (I/R) injury, DF 2156A decreased PMN and monocyte-macrophage infiltration and associated hepatocellular injury. CONCLUSION AND IMPLICATIONS: DF 2156A is a non-competitive allosteric inhibitor of both IL-8 receptors CXCR1 and CXCR2. It prevented experimental angiogenesis and hepatic I/R injury in vivo and, therefore, has therapeutic potential for acute and chronic inflammatory diseases.

Neuronal ceroid lipofuscinosis in a Vietnamese pot-bellied pig (Sus scrofa).

The neuronal ceroid ipofuscinoses (NCL) are a group of heritable, neurodegenerative, storage diseases, typically with an autosomal recessive mode of inheritance. Cytoplasmic accumulation of storage material in cells of the nervous system and, variably in other tissues, characterizes NCL. NCL has been reported in many animal species, but to the authors' knowledge, this is the first report of the disease in a pig. Blindness and seizures are common clinical signs of disease, neither of which was a feature in this pig. The lesions were restricted to the central nervous system, which was diffusely affected, with the most severe lesions in the hippocampus, cerebral cortex, and cerebellum. The histologic lesions included neuronal loss and gliosis, which contributed to mild cerebrocortical and cerebellar atrophy and accumulation of autofluorescent storage material in neurons and glial cells. The storage material had morphologic, histologic, and ultrastructural properties typical of NCL.

Pathology of end-stage remodeling in a family of cats with hypertrophic cardiomyopathy.

End-stage hypertrophic cardiomyopathy (ES-HCM), affecting 5-10% of human hypertrophic cardiomyopathy (HCM) patients, is characterized by relative thinning of the ventricular walls and septum with dilation of the ventricular lumen, decreased fractional shortening, and progression to heart failure. C. J. Baty and others recently documented similar progressive changes to ES-HCM in a family of four cats through serial echocardiograms. At the time of heart failure, these cats exhibited changes similar to those exhibited by human ES-HCM patients. Our objectives were to describe the pathologic alterations associated with ES-HCM and investigate the pathogenesis in three of the four cats. Grossly, there was left atrial dilation with relative thinning of the interventricular septum (IVS) and left ventricular free wall (LVFW). The left atrium contained large thrombi in two of the three cats, and all three cats died following thromboembolization of the aortic bifurcation. Histologically, all three cats had subendocardial and myocardial fibrosis, predominantly of the IVS and LVFW, and one cat had acute, multifocal, myocardial infarcts with mononuclear inflammatory cell infiltrates. The pathogenesis of ES-HCM is uncertain, but theories implicate occlusion of the coronary blood flow by thickening of the coronary vessels, coronary vascular thromboembolism or coronary vessel spasm, apoptosis of myocytes, and myocardial hypertrophy beyond the ability of the vasculature to supply blood. Apoptosis assays did not reveal any apoptotic myocytes. Considering the hypercoagulative state of these cats, coronary vascular thromboembolism could be a major contributing factor. We cannot exclude apoptosis or coronary vessel spasm on the basis of the data presented.

A model of mucopolysaccharidosis IIIB (Sanfilippo syndrome type IIIB): N-acetyl-alpha-D-glucosaminidase deficiency in Schipperke dogs.

Mucopolysaccharidosis III (MPS III) is characterized by lysosomal accumulation of the glycosaminoglycan (GAG) heparan sulphate (HS). In humans, the disease manifests in early childhood, and is characterized by a progressive central neuropathy leading to death in the second decade. This disease has also been described in mice (MPS IIIA and IIIB), dogs (MPS IIIA), emus (MPS IIIB) and goats (MPS IIID). We now report on dogs with naturally occurring MPS IIIB, detailing the clinical signs, diagnosis, histopathology, tissue enzymology and substrate levels. Two 3-year-old Schipperke dogs were evaluated for tremors and episodes of stumbling. Examination of the animals found signs consistent with cerebellar disease including dysmetria, hind limb ataxia and a wide-based stance with truncal swaying. There were mildly dystrophic corneas and small peripheral foci of retinal degeneration. Magnetic resonance imaging of the brain and skeletal radiographs were normal. Intracytoplasmic granules were found in the white cells of peripheral blood and cerebral spinal fluid, and in myeloid lineages in bone marrow. Electrophoresis of urinary GAGs indicated the presence of HS, while assays of cultured fibroblasts found N-acetyl-alpha-D-glucosaminidase (Naglu) activity of between 4.3% and 9.2% of normal. Owing to neurological deterioration, both dogs were euthanized, and post-mortem examinations were performed. Biochemical studies of liver and kidney from both animals demonstrated profound deficiency of Naglu activity and abnormally high GAG levels. Pathology of the brain included severe cerebellar atrophy, Purkinje cell loss, and cytoplasmic vacuolation in neurons and perithelial cells throughout the central nervous system. Pedigree analyses and Naglu levels of family members supported an autosomal recessive mode of inheritance. Using an obligate heterozygote, a breeding colony has been established to aid in understanding the pathogenesis of MPS IIIB and testing of potential therapies.

Synthesis of phenothiazine derivatives as potential inhibitors of phospholipase C.

In order to study the structure-activity relationships of phenothiazine derivatives inhibiting phosphatidylinositol-specific phospholipase C (PI-PLC), the synthesis of some phenothiazine amide, amine and ester derivatives was performed mainly by reacting 10H-phenothiazine-10-propanoyl chloride with some amines and alcohols; the resulting amides were reduced with borane to yield the corresponding amines. Starting from 2-chloro and 2-trifluoromethyl-10H-phenothiazine-10-propanoyl chloride two amides were synthesized. The inhibiting activity on PI-PLC from human platelets is reported.

Synthesis of some carbamates of myo-inositol.

The syntheses are described of the 1-O-carbamoyl (11), 1-O-carbamoyl-2-O-stearoyl (10), 1-O-(acetylcarbamoyl)-2-O-stearoyl (12), 1-O-(heptylcarbamoyl) (13), 2-O-(heptylcarbamoyl) (14) 1,2-di-O-(heptylcarbamoyl) (15), and 1-O-(octadecylcarbamoyl) (16) derivatives of myo-inositol. None of these compounds had significant activity against phospholipase C.

[Infections caused by central venous catheter used in surgery]. / Infezioni da catetere venoso centrale in chirurgia.

The central venous catheters, now usually adopted in surgical patients, present some potential septic risks, and the longer the catheter is in place, the more dangerous it is. The authors report their experience on 130 central venous catheters, out of which 96 were used for TPN administration and 34 for monitoring purposes. The catheters were introduced through subclavian, internal jugular or basilic veins, in accordance with a standardized technique. The observed infection percentage, caused by the catheters, was 7.7%; the infection was easily controlled by the catheter removal and a proper antibiotic therapy. The only death, surely due to sepsis, was caused by Candida fungus in an immunosuppressed female patient. Therefore the authors stress the importance to prevent septic complications in order to avoid fatal ones.

[Comparison of 3 different approaches to central veins in total parenteral nutrition]. / Confronto fra tre diverse vie di accesso venoso centrale in nutrizione parenterale totale.

The authors report their experience related to a series of 96 consecutive central venous catheters location through subclavian, right internal jugular, basilic and cephalic veins for TPN administration. Because of the specific complications reported, they are in favour of the trans-basilic peripheral approach for a short term TPN; the internal jugular or the subclavian way are indicated for long term ones. In addition, they stress the importance to limit the use of multilumen catheters just when absolutely necessary, due to the increased infection percentage.