@article{BenKraiemSauerNorwigetal.2021, author = {Ben-Kraiem, Adel and Sauer, Reine-Solange and Norwig, Carla and Popp, Maria and Bettenhausen, Anna-Lena and Atalla, Mariam Sobhy and Brack, Alexander and Blum, Robert and Doppler, Kathrin and Rittner, Heike Lydia}, title = {Selective blood-nerve barrier leakiness with claudin-1 and vessel-associated macrophage loss in diabetic polyneuropathy}, series = {Journal of Molecular Medicine}, volume = {99}, journal = {Journal of Molecular Medicine}, number = {9}, doi = {10.1007/s00109-021-02091-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265237}, pages = {1237-1250}, year = {2021}, abstract = {Diabetic polyneuropathy (DPN) is the most common complication in diabetes and can be painful in up to 26\% of all diabetic patients. Peripheral nerves are shielded by the blood-nerve barrier (BNB) consisting of the perineurium and endoneurial vessels. So far, there are conflicting results regarding the role and function of the BNB in the pathophysiology of DPN. In this study, we analyzed the spatiotemporal tight junction protein profile, barrier permeability, and vessel-associated macrophages in Wistar rats with streptozotocin-induced DPN. In these rats, mechanical hypersensitivity developed after 2 weeks and loss of motor function after 8 weeks, while the BNB and the blood-DRG barrier were leakier for small, but not for large molecules after 8 weeks only. The blood-spinal cord barrier remained sealed throughout the observation period. No gross changes in tight junction protein or cytokine expression were observed in all barriers to blood. However, expression of Cldn1 mRNA in perineurium was specifically downregulated in conjunction with weaker vessel-associated macrophage shielding of the BNB. Our results underline the role of specific tight junction proteins and BNB breakdown in DPN maintenance and differentiate DPN from traumatic nerve injury. Targeting claudins and sealing the BNB could stabilize pain and prevent further nerve damage.}, language = {en} } @article{OehlerKlokaMohammadietal.2020, author = {Oehler, Beatrice and Kloka, Jan and Mohammadi, Milad and Ben-Kraiem, Adel and Rittner, Heike L.}, title = {D-4F, an ApoA-I mimetic peptide ameliorating TRPA1-mediated nocifensive behaviour in a model of neurogenic inflammation}, series = {Molecular Pain}, volume = {16}, journal = {Molecular Pain}, doi = {10.1177/1744806920903848}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236061}, pages = {1-11}, year = {2020}, abstract = {Background High doses of capsaicin are recommended for the treatment of neuropathic pain. However, low doses evoke mechanical hypersensitivity. Activation of the capsaicin chemosensor transient receptor potential vanilloid 1 (TRPV1) induces neurogenic inflammation. In addition to the release of pro-inflammatory mediators, reactive oxygen species are produced. These highly reactive molecules generate oxidised phospholipids and 4-hydroxynonenal (4-HNE) which then directly activate TRP ankyrin 1 (TRPA1). The apolipoprotein A-I mimetic peptide D-4F neutralises oxidised phospholipids. Here, we asked whether D-4F ameliorates neurogenic hypersensitivity in rodents by targeting reactive oxygen species and 4-HNE in the capsaicin-evoked pain model. Results Co-application of D-4F ameliorated capsaicin-induced mechanical hypersensitivity and allodynia as well as persistent heat hypersensitivity measured by Randell-Selitto, von Frey and Hargreaves test, respectively. In addition, mechanical hypersensitivity was blocked after co-injection of D-4F with the reactive oxygen species analogue H2O2 or 4-HNE. In vitro studies on dorsal root ganglion neurons and stably transfected cell lines revealed a TRPA1-dependent inhibition of the calcium influx when agonists were pre-incubated with D-4F. The capsaicin-induced calcium influx in TRPV1-expressing cell lines and dorsal root ganglion neurons sustained in the presence of D-4F. Conclusions D-4F is a promising compound to ameliorate TRPA1-dependent hypersensitivity during neurogenic inflammation.}, language = {en} }