Effect of Surgical and Chemical Sensory Denervation on Non-neural Expression of the Transient Receptor Potential Vanilloid 1 (TRPV1) Receptors in the Rat

Pretreatment with the ultrapotent capsaicin analog resiniferatoxin (RTX) has been applied as a selective pharmacological tool in inflammation and pain studies to desensitize transient receptor potential vanilloid 1 (TRPV1) receptor-expressing sensory nerve endings. The discovery of TRPV1 receptor on non-neural cells challenges systemic RTX desensitization as a method acting exclusively on a population of sensory neurons, but not on non-neural cells. Systemic RTX desensitization was used for chemical denervation and transection of the sciatic and saphenous nerves for surgical denervation in rats. Quantitative real-time PCR and immunohistochemistry were applied to investigate the presence and alterations of the TRPV1 receptor mRNA and protein following chemical and surgical denervation. We provided the first evidence for non-neural TRPV1 immunopositivity and mRNA expression in the rat dorsal paw and plantar skin as well as the oral mucosa. Neither chemical nor surgical denervation influenced the level of TRPV1 receptor mRNA and protein expression in non-neural cells of either skin regions or mucosa. Therefore, RTX and consequently capsaicin remain to be considered as selective neurotoxins for a population of primary afferent neurons.     

FcRn mediates elongated serum half-life of human IgG in cattle

IgG has the longest survival time in the circulation of the Ig classes and the lowest fractional catabolic rate. The neonatal Fc receptor (FcRn) plays an important role in regulating these processes. Recently, we have cloned the bovine neonatal Fc receptor (bFcRn) alpha chain and detected its expression in various epithelial cells which are mediating IgG secretion. However, its function in IgG homeostasis has not been investigated. In the current study, we analyzed the binding affinity of bovine and human IgGs to bFcRn using surface plasmon resonance and by in vitro radioreceptor binding assays. As human IgG binds stronger to the bFcRn, than bovine IgG at pH 6, we subsequently analyzed its catabolism in normal and transchromosomic calves that produce human Igs. Pharmacokinetic studies showed that human IgG had approximately 33 days serum half-life both in normal and transchromosomic calves, which is more than two times longer than its bovine counterpart. We also demonstrate FcRn expression in endothelial cells and in the kidney which are supposed to be involved in IgG metabolism. These data suggest that bFcRn is involved in IgG homeostasis in cattle and furthermore, that the transchromosomic calves producing human Igs can effectively protect their human IgGs which have implications for successful large-scale production of therapeutic antibodies.     

Transposons for gene therapy!

Gene therapy is a promising strategy for the treatment of several inherited and acquired human diseases. Several vector platforms exist for the delivery of therapeutic nucleic acids into cells. Vectors based on viruses are very efficient at introducing gene constructs into cells, but their use has been associated with genotoxic effects of vector integration or immunological complications due to repeated administration in vivo. Non-viral vectors are easier to engineer and manufacture, but their efficient delivery into cells is a major challenge, and the lack of their chromosomal integration precludes long-term therapeutic effects. Transposable elements are non-viral gene delivery vehicles found ubiquitously in nature. Transposon-based vectors have the capacity of stable genomic integration and long-lasting expression of transgene constructs in cells. Molecular reconstruction of Sleeping Beauty, an ancient transposon in fish, represents a cornerstone in applying transposition-mediated gene delivery in vertebrate species, including humans. This review summarizes the state-of-the-art in the application of transposable elements for therapeutic gene transfer, and identifies key targets for the development of transposon-based gene vectors with enhanced efficacy and safety for human applications.     

DNA repair in antibody somatic hypermutation

Somatic hypermutation (SHM) underlies the generation of a diverse repertoire of high-affinity antibodies. It is effected by a two-step process: (i) DNA lesions initiated by activation-induced cytidine deaminase (AID), and (ii) lesion repair by the combined intervention of DNA replication and repair factors that include mismatch repair (MMR) proteins and translesion DNA synthesis (TLS) polymerases. AID and TLS polymerases that are crucial to SHM, namely polymerase (pol) theta, pol zeta and pol eta, are induced in B cells by the stimuli that are required to trigger this process: B-cell receptor crosslinking and CD40 engagement by CD154. These polymerases, together with MMR proteins and other DNA replication and repair factors, could assemble to form a multimolecular complex ("mutasome") at the site of DNA lesions. Molecular interactions in the mutasome would result in a "polymerase switch", that is, the substitution of the high-fidelity replicative pol delta and pol epsilon with the TLS pol theta, pol eta, Rev1, pol zeta and, perhaps, pol iota, which are error-prone and crucially insert mismatches or mutations while repairing DNA lesions. Here, we place these concepts in the context of the existing in vivo and in vitro findings, and discuss an integrated mechanistic model of SHM.     

Accelerated pre‐senile systemic amyloidosis in PACAP knockout mice – a protective role of PACAP in age‐related degenerative processes

Dysregulation of neuropeptides may play an important role in aging‐induced impairments. Among them, pituitary adenylate cyclase‐activating polypeptide (PACAP) is a potent cytoprotective peptide that provides an endogenous control against a variety of tissue‐damaging stimuli. We hypothesized that the progressive decline of PACAP throughout life and the well‐known general cytoprotective effects of PACAP lead to age‐related pathophysiological changes in PACAP deficiency, supported by the increased vulnerability to various stressors of animals partially or totally lacking PACAP. Using young and aging CD1 PACAP knockout (KO) and wild type (WT) mice, we demonstrated pre‐senile amyloidosis in young PACAP KO animals and showed that senile amyloidosis appeared accelerated, more generalized, more severe, and affected more individuals. Histopathology showed age‐related systemic amyloidosis with mainly kidney, spleen, liver, skin, thyroid, intestinal, tracheal, and esophageal involvement. Mass spectrometry‐based proteomic analysis, reconfirmed with immunohistochemistry, revealed that apolipoprotein‐AIV was the main amyloid protein in the deposits together with several accompanying proteins. Although the local amyloidogenic protein expression was disturbed in KO animals, no difference was found in laboratory lipid parameters, suggesting a complex pathway leading to increased age‐related degeneration with amyloid deposits in the absence of PACAP. In spite of no marked inflammatory histological changes or blood test parameters, we detected a disturbed cytokine profile that possibly creates a pro‐inflammatory milieu favoring amyloid deposition. In summary, here we describe accelerated systemic senile amyloidosis in PACAP gene‐deficient mice, which might indicate an early aging phenomenon in this mouse strain. Thus, PACAP KO mice could serve as a model of accelerated aging with human relevance. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

High early uterine vascular resistance values increase the risk of adverse pregnancy outcome independently from placental VEGF and VEGFR1 reactivities

ObjectiveFrom data in the literature, we hypothesized that high vascular resistance values in the uterine arteries at the end of the first trimester would increase adverse pregnancy outcomes and therefore might be accompanied by changes in VEGF/VEGFR1 immunoreactivities.Study designIn our university hospital 82 women (Study I n = 62 and Study II n = 20) were divided into two groups according to their uterine vascular resistance values. Uterine vascular resistance values were measured in the 10–13th weeks of gestation by color-Doppler ultrasonography. Women were divided into low and high vascular resistance groups. In the prospective follow-up study (Study I) the data of the pregnancy outcome were recorded. In cross-sectional study (Study II), VEGF and VEGFR1 immunoreactivities were measured on the tissue samples from women who underwent termination of pregnancy.ResultsIn the high vascular resistance group (PI > 2.3), the probability of adverse pregnancy outcome was significantly higher (40.0% vs. 12.8%). No differences in VEGF and VEGFR1 immunoreactivities were observed between groups. In both groups, intense VEGF immunoreactivity was observed in the maternal glandular epithelium and in the decidual cells. Weak reactivity was observed in the villous trophoblast. VEGFR1 immunoreactivity was intense in all regions.ConclusionsOur data suggest that high vascular resistance values in the first trimester are independent from VEGF/VEGFR1 immunoreactivities and markedly increase the probability of adverse pregnancy outcomes. This may be used for early screening of pregnant women in the first trimester.     

Involvement of capsaicin-sensitive afferents and the Transient Receptor Potential Vanilloid 1 Receptor in xylene-induced nocifensive behaviour and inflammation in the mouse

The inflammatory actions of xylene, an aromatic irritant and sensitizing agent, were described to be predominantly neurogenic in the rat, but the mechanism and the role of the Transient Receptor Potential Vanilloid 1 (TRPV1) capsaicin receptor localized on a subpopulation of sensory nerves has not been elucidated. This paper characterizes the involvement of capsaicin-sensitive afferents and the TRPV1 receptor in nociceptive and acute inflammatory effects of xylene in the mouse. Topical application of xylene on the paw induced a short, intensive nocifensive behaviour characterized by paw liftings and shakings, which was more intensive in Balb/c than in C57Bl/6 mice. Genetic deletion of the TRPV1 receptor as well as destroying capsaicin-sensitive nerve terminals with resiniferatoxin (RTX) pretreatment markedly reduced, but did not abolish nocifensive behaviours. In respect to the xylene-induced plasma protein extravasation detected by Evans blue leakage, significant difference was neither observed between the Balb/c and C57Bl/6 strains, nor the ear and the dorsal paw skin. These inflammatory responses were diminished in the RTX pretreated group, but not in the TRPV1 gene-deleted one. Injection of the antioxidant N-acetylcysteine 15 min prior to xylene smearing significantly reduced plasma protein extravasation at both sites. These results demonstrate that xylene-induced acute nocifensive behaviour is mediated by capsaicin-sensitive afferents via TRPV1 receptor activation in mice. Neurogenic inflammatory components play an important role in xylene-induced plasma protein extravasation, but independently of the TRPV1 ion channel. Reactive oxygen or carbonyl species participate in this process presumably via stimulation of the TRPA1 channel.     

Spatial and temporal visual properties of the neurons in the intermediate layers of the superior colliculus

Although the visual perception depends on the integration of spatial and temporal information, no knowledge is available concerning the responsiveness of neurons in the intermediate layers of the superior colliculus (SCi) to extended visual grating stimuli. Accordingly, we set out to investigate the responsiveness of these neurons in halothane-anesthetized cats to drifting sinewave gratings at various spatial and temporal frequencies. The SCi units responded optimally to gratings of low spatial frequencies (none of the analyzed SCi units exhibited maximal activity to spatial frequencies higher than 0.3 c/deg) and exhibited low spatial resolution and narrow spatial frequency tuning. On the other hand, the SCi neurons preferred high temporal frequencies and exhibited high temporal resolution. Thus, the SCi neurons seem to be good spatio–temporal filters of visual information in the low spatial and high temporal frequency domain. Based upon the above summarized results we suggest that the SCi units can detect large contours moving at high velocities well, but are unable to distinguish small details. This is in line with the generally held view that the SCi could possess visuomotor function, such as organizing the complex, sensory-guided oculomotor and skeletomotor responses during the self-motion of the animal.